1 | /* Target hook definitions. |
2 | Copyright (C) 2001-2023 Free Software Foundation, Inc. |
3 | |
4 | This program is free software; you can redistribute it and/or modify it |
5 | under the terms of the GNU General Public License as published by the |
6 | Free Software Foundation; either version 3, or (at your option) any |
7 | later version. |
8 | |
9 | This program is distributed in the hope that it will be useful, |
10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
12 | GNU General Public License for more details. |
13 | |
14 | You should have received a copy of the GNU General Public License |
15 | along with this program; see the file COPYING3. If not see |
16 | <http://www.gnu.org/licenses/>. |
17 | |
18 | In other words, you are welcome to use, share and improve this program. |
19 | You are forbidden to forbid anyone else to use, share and improve |
20 | what you give them. Help stamp out software-hoarding! */ |
21 | |
22 | /* See target-hooks-macros.h for details of macros that should be |
23 | provided by the including file, and how to use them here. */ |
24 | #include "target-hooks-macros.h" |
25 | |
26 | #undef HOOK_TYPE |
27 | #define HOOK_TYPE "Target Hook" |
28 | |
29 | HOOK_VECTOR (TARGET_INITIALIZER, gcc_target) |
30 | |
31 | /* Functions that output assembler for the target. */ |
32 | #define HOOK_PREFIX "TARGET_ASM_" |
33 | HOOK_VECTOR (TARGET_ASM_OUT, asm_out) |
34 | |
35 | /* Opening and closing parentheses for asm expression grouping. */ |
36 | DEFHOOKPOD |
37 | (open_paren, |
38 | "These target hooks are C string constants, describing the syntax in the\n\ |
39 | assembler for grouping arithmetic expressions. If not overridden, they\n\ |
40 | default to normal parentheses, which is correct for most assemblers." , |
41 | const char *, "(" ) |
42 | DEFHOOKPODX (close_paren, const char *, ")" ) |
43 | |
44 | /* Assembler instructions for creating various kinds of integer object. */ |
45 | DEFHOOKPOD |
46 | (byte_op, |
47 | "@deftypevrx {Target Hook} {const char *} TARGET_ASM_ALIGNED_HI_OP\n\ |
48 | @deftypevrx {Target Hook} {const char *} TARGET_ASM_ALIGNED_PSI_OP\n\ |
49 | @deftypevrx {Target Hook} {const char *} TARGET_ASM_ALIGNED_SI_OP\n\ |
50 | @deftypevrx {Target Hook} {const char *} TARGET_ASM_ALIGNED_PDI_OP\n\ |
51 | @deftypevrx {Target Hook} {const char *} TARGET_ASM_ALIGNED_DI_OP\n\ |
52 | @deftypevrx {Target Hook} {const char *} TARGET_ASM_ALIGNED_PTI_OP\n\ |
53 | @deftypevrx {Target Hook} {const char *} TARGET_ASM_ALIGNED_TI_OP\n\ |
54 | @deftypevrx {Target Hook} {const char *} TARGET_ASM_UNALIGNED_HI_OP\n\ |
55 | @deftypevrx {Target Hook} {const char *} TARGET_ASM_UNALIGNED_PSI_OP\n\ |
56 | @deftypevrx {Target Hook} {const char *} TARGET_ASM_UNALIGNED_SI_OP\n\ |
57 | @deftypevrx {Target Hook} {const char *} TARGET_ASM_UNALIGNED_PDI_OP\n\ |
58 | @deftypevrx {Target Hook} {const char *} TARGET_ASM_UNALIGNED_DI_OP\n\ |
59 | @deftypevrx {Target Hook} {const char *} TARGET_ASM_UNALIGNED_PTI_OP\n\ |
60 | @deftypevrx {Target Hook} {const char *} TARGET_ASM_UNALIGNED_TI_OP\n\ |
61 | These hooks specify assembly directives for creating certain kinds\n\ |
62 | of integer object. The @code{TARGET_ASM_BYTE_OP} directive creates a\n\ |
63 | byte-sized object, the @code{TARGET_ASM_ALIGNED_HI_OP} one creates an\n\ |
64 | aligned two-byte object, and so on. Any of the hooks may be\n\ |
65 | @code{NULL}, indicating that no suitable directive is available.\n\ |
66 | \n\ |
67 | The compiler will print these strings at the start of a new line,\n\ |
68 | followed immediately by the object's initial value. In most cases,\n\ |
69 | the string should contain a tab, a pseudo-op, and then another tab." , |
70 | const char *, "\t.byte\t" ) |
71 | DEFHOOKPOD (aligned_op, "*" , struct asm_int_op, TARGET_ASM_ALIGNED_INT_OP) |
72 | DEFHOOKPOD (unaligned_op, "*" , struct asm_int_op, TARGET_ASM_UNALIGNED_INT_OP) |
73 | |
74 | /* Try to output the assembler code for an integer object whose |
75 | value is given by X. SIZE is the size of the object in bytes and |
76 | ALIGNED_P indicates whether it is aligned. Return true if |
77 | successful. Only handles cases for which BYTE_OP, ALIGNED_OP |
78 | and UNALIGNED_OP are NULL. */ |
79 | DEFHOOK |
80 | (integer, |
81 | "The @code{assemble_integer} function uses this hook to output an\n\ |
82 | integer object. @var{x} is the object's value, @var{size} is its size\n\ |
83 | in bytes and @var{aligned_p} indicates whether it is aligned. The\n\ |
84 | function should return @code{true} if it was able to output the\n\ |
85 | object. If it returns false, @code{assemble_integer} will try to\n\ |
86 | split the object into smaller parts.\n\ |
87 | \n\ |
88 | The default implementation of this hook will use the\n\ |
89 | @code{TARGET_ASM_BYTE_OP} family of strings, returning @code{false}\n\ |
90 | when the relevant string is @code{NULL}." , |
91 | /* Only handles cases for which BYTE_OP, ALIGNED_OP and UNALIGNED_OP are |
92 | NULL. */ |
93 | bool, (rtx x, unsigned int size, int aligned_p), |
94 | default_assemble_integer) |
95 | |
96 | /* Assembly strings required after the .cfi_startproc label. */ |
97 | DEFHOOK |
98 | (post_cfi_startproc, |
99 | "This target hook is used to emit assembly strings required by the target\n\ |
100 | after the .cfi_startproc directive. The first argument is the file stream to\n\ |
101 | write the strings to and the second argument is the function\'s declaration. The\n\ |
102 | expected use is to add more .cfi_* directives.\n\ |
103 | \n\ |
104 | The default is to not output any assembly strings." , |
105 | void, (FILE *, tree), |
106 | hook_void_FILEptr_tree) |
107 | |
108 | /* Notify the backend that we have completed emitting the data for a |
109 | decl. */ |
110 | DEFHOOK |
111 | (decl_end, |
112 | "Define this hook if the target assembler requires a special marker to\n\ |
113 | terminate an initialized variable declaration." , |
114 | void, (void), |
115 | hook_void_void) |
116 | |
117 | /* Output code that will globalize a label. */ |
118 | DEFHOOK |
119 | (globalize_label, |
120 | "This target hook is a function to output to the stdio stream\n\ |
121 | @var{stream} some commands that will make the label @var{name} global;\n\ |
122 | that is, available for reference from other files.\n\ |
123 | \n\ |
124 | The default implementation relies on a proper definition of\n\ |
125 | @code{GLOBAL_ASM_OP}." , |
126 | void, (FILE *stream, const char *name), |
127 | default_globalize_label) |
128 | |
129 | /* Output code that will globalize a declaration. */ |
130 | DEFHOOK |
131 | (globalize_decl_name, |
132 | "This target hook is a function to output to the stdio stream\n\ |
133 | @var{stream} some commands that will make the name associated with @var{decl}\n\ |
134 | global; that is, available for reference from other files.\n\ |
135 | \n\ |
136 | The default implementation uses the TARGET_ASM_GLOBALIZE_LABEL target hook." , |
137 | void, (FILE *stream, tree decl), default_globalize_decl_name) |
138 | |
139 | /* Output code that will declare an external variable. */ |
140 | DEFHOOK |
141 | (assemble_undefined_decl, |
142 | "This target hook is a function to output to the stdio stream\n\ |
143 | @var{stream} some commands that will declare the name associated with\n\ |
144 | @var{decl} which is not defined in the current translation unit. Most\n\ |
145 | assemblers do not require anything to be output in this case." , |
146 | void, (FILE *stream, const char *name, const_tree decl), |
147 | hook_void_FILEptr_constcharptr_const_tree) |
148 | |
149 | /* Output code that will emit a label for unwind info, if this |
150 | target requires such labels. Second argument is the decl the |
151 | unwind info is associated with, third is a boolean: true if |
152 | this is for exception handling, fourth is a boolean: true if |
153 | this is only a placeholder for an omitted FDE. */ |
154 | DEFHOOK |
155 | (emit_unwind_label, |
156 | "This target hook emits a label at the beginning of each FDE@. It\n\ |
157 | should be defined on targets where FDEs need special labels, and it\n\ |
158 | should write the appropriate label, for the FDE associated with the\n\ |
159 | function declaration @var{decl}, to the stdio stream @var{stream}.\n\ |
160 | The third argument, @var{for_eh}, is a boolean: true if this is for an\n\ |
161 | exception table. The fourth argument, @var{empty}, is a boolean:\n\ |
162 | true if this is a placeholder label for an omitted FDE@.\n\ |
163 | \n\ |
164 | The default is that FDEs are not given nonlocal labels." , |
165 | void, (FILE *stream, tree decl, int for_eh, int empty), |
166 | default_emit_unwind_label) |
167 | |
168 | /* Output code that will emit a label to divide up the exception table. */ |
169 | DEFHOOK |
170 | (emit_except_table_label, |
171 | "This target hook emits a label at the beginning of the exception table.\n\ |
172 | It should be defined on targets where it is desirable for the table\n\ |
173 | to be broken up according to function.\n\ |
174 | \n\ |
175 | The default is that no label is emitted." , |
176 | void, (FILE *stream), |
177 | default_emit_except_table_label) |
178 | |
179 | /* Emit a directive for setting the personality for the function. */ |
180 | DEFHOOK |
181 | (emit_except_personality, |
182 | "If the target implements @code{TARGET_ASM_UNWIND_EMIT}, this hook may be\n\ |
183 | used to emit a directive to install a personality hook into the unwind\n\ |
184 | info. This hook should not be used if dwarf2 unwind info is used." , |
185 | void, (rtx personality), |
186 | NULL) |
187 | |
188 | /* If necessary, modify personality and LSDA references to handle |
189 | indirection. This is used when the assembler supports CFI directives. */ |
190 | DEFHOOK |
191 | (make_eh_symbol_indirect, |
192 | "If necessary, modify personality and LSDA references to handle indirection.\n\ |
193 | The original symbol is in @code{origsymbol} and if @code{pubvis} is true\n\ |
194 | the symbol is visible outside the TU." , |
195 | rtx, (rtx origsymbol, bool pubvis), |
196 | NULL) |
197 | |
198 | /* Emit any directives required to unwind this instruction. */ |
199 | DEFHOOK |
200 | (unwind_emit, |
201 | "This target hook emits assembly directives required to unwind the\n\ |
202 | given instruction. This is only used when @code{TARGET_EXCEPT_UNWIND_INFO}\n\ |
203 | returns @code{UI_TARGET}." , |
204 | void, (FILE *stream, rtx_insn *insn), |
205 | NULL) |
206 | |
207 | DEFHOOKPOD |
208 | (unwind_emit_before_insn, |
209 | "True if the @code{TARGET_ASM_UNWIND_EMIT} hook should be called before\n\ |
210 | the assembly for @var{insn} has been emitted, false if the hook should\n\ |
211 | be called afterward." , |
212 | bool, true) |
213 | |
214 | /* Return true if the target needs extra instructions to restore the current |
215 | frame address after a DW_CFA_restore_state opcode. */ |
216 | DEFHOOK |
217 | (should_restore_cfa_state, |
218 | "For DWARF-based unwind frames, two CFI instructions provide for save and\n\ |
219 | restore of register state. GCC maintains the current frame address (CFA)\n\ |
220 | separately from the register bank but the unwinder in libgcc preserves this\n\ |
221 | state along with the registers (and this is expected by the code that writes\n\ |
222 | the unwind frames). This hook allows the target to specify that the CFA data\n\ |
223 | is not saved/restored along with the registers by the target unwinder so that\n\ |
224 | suitable additional instructions should be emitted to restore it." , |
225 | bool, (void), |
226 | hook_bool_void_false) |
227 | |
228 | /* Generate an internal label. |
229 | For now this is just a wrapper for ASM_GENERATE_INTERNAL_LABEL. */ |
230 | DEFHOOK_UNDOC |
231 | (generate_internal_label, |
232 | "" , |
233 | void, (char *buf, const char *prefix, unsigned long labelno), |
234 | default_generate_internal_label) |
235 | |
236 | /* Output an internal label. */ |
237 | DEFHOOK |
238 | (internal_label, |
239 | "A function to output to the stdio stream @var{stream} a label whose\n\ |
240 | name is made from the string @var{prefix} and the number @var{labelno}.\n\ |
241 | \n\ |
242 | It is absolutely essential that these labels be distinct from the labels\n\ |
243 | used for user-level functions and variables. Otherwise, certain programs\n\ |
244 | will have name conflicts with internal labels.\n\ |
245 | \n\ |
246 | It is desirable to exclude internal labels from the symbol table of the\n\ |
247 | object file. Most assemblers have a naming convention for labels that\n\ |
248 | should be excluded; on many systems, the letter @samp{L} at the\n\ |
249 | beginning of a label has this effect. You should find out what\n\ |
250 | convention your system uses, and follow it.\n\ |
251 | \n\ |
252 | The default version of this function utilizes @code{ASM_GENERATE_INTERNAL_LABEL}." , |
253 | void, (FILE *stream, const char *prefix, unsigned long labelno), |
254 | default_internal_label) |
255 | |
256 | /* Output label for the constant. */ |
257 | DEFHOOK |
258 | (declare_constant_name, |
259 | "A target hook to output to the stdio stream @var{file} any text necessary\n\ |
260 | for declaring the name @var{name} of a constant which is being defined. This\n\ |
261 | target hook is responsible for outputting the label definition (perhaps using\n\ |
262 | @code{assemble_label}). The argument @var{exp} is the value of the constant,\n\ |
263 | and @var{size} is the size of the constant in bytes. The @var{name}\n\ |
264 | will be an internal label.\n\ |
265 | \n\ |
266 | The default version of this target hook, define the @var{name} in the\n\ |
267 | usual manner as a label (by means of @code{assemble_label}).\n\ |
268 | \n\ |
269 | You may wish to use @code{ASM_OUTPUT_TYPE_DIRECTIVE} in this target hook." , |
270 | void, (FILE *file, const char *name, const_tree expr, HOST_WIDE_INT size), |
271 | default_asm_declare_constant_name) |
272 | |
273 | /* Emit a ttype table reference to a typeinfo object. */ |
274 | DEFHOOK |
275 | (ttype, |
276 | "This hook is used to output a reference from a frame unwinding table to\n\ |
277 | the type_info object identified by @var{sym}. It should return @code{true}\n\ |
278 | if the reference was output. Returning @code{false} will cause the\n\ |
279 | reference to be output using the normal Dwarf2 routines." , |
280 | bool, (rtx sym), |
281 | hook_bool_rtx_false) |
282 | |
283 | /* Emit an assembler directive to set visibility for the symbol |
284 | associated with the tree decl. */ |
285 | DEFHOOK |
286 | (assemble_visibility, |
287 | "This target hook is a function to output to @var{asm_out_file} some\n\ |
288 | commands that will make the symbol(s) associated with @var{decl} have\n\ |
289 | hidden, protected or internal visibility as specified by @var{visibility}." , |
290 | void, (tree decl, int visibility), |
291 | default_assemble_visibility) |
292 | |
293 | DEFHOOK |
294 | (print_patchable_function_entry, |
295 | "Generate a patchable area at the function start, consisting of\n\ |
296 | @var{patch_area_size} NOP instructions. If the target supports named\n\ |
297 | sections and if @var{record_p} is true, insert a pointer to the current\n\ |
298 | location in the table of patchable functions. The default implementation\n\ |
299 | of the hook places the table of pointers in the special section named\n\ |
300 | @code{__patchable_function_entries}." , |
301 | void, (FILE *file, unsigned HOST_WIDE_INT patch_area_size, bool record_p), |
302 | default_print_patchable_function_entry) |
303 | |
304 | /* Output the assembler code for entry to a function. */ |
305 | DEFHOOK |
306 | (function_prologue, |
307 | "If defined, a function that outputs the assembler code for entry to a\n\ |
308 | function. The prologue is responsible for setting up the stack frame,\n\ |
309 | initializing the frame pointer register, saving registers that must be\n\ |
310 | saved, and allocating @var{size} additional bytes of storage for the\n\ |
311 | local variables. @var{file} is a stdio stream to which the assembler\n\ |
312 | code should be output.\n\ |
313 | \n\ |
314 | The label for the beginning of the function need not be output by this\n\ |
315 | macro. That has already been done when the macro is run.\n\ |
316 | \n\ |
317 | @findex regs_ever_live\n\ |
318 | To determine which registers to save, the macro can refer to the array\n\ |
319 | @code{regs_ever_live}: element @var{r} is nonzero if hard register\n\ |
320 | @var{r} is used anywhere within the function. This implies the function\n\ |
321 | prologue should save register @var{r}, provided it is not one of the\n\ |
322 | call-used registers. (@code{TARGET_ASM_FUNCTION_EPILOGUE} must likewise use\n\ |
323 | @code{regs_ever_live}.)\n\ |
324 | \n\ |
325 | On machines that have ``register windows'', the function entry code does\n\ |
326 | not save on the stack the registers that are in the windows, even if\n\ |
327 | they are supposed to be preserved by function calls; instead it takes\n\ |
328 | appropriate steps to ``push'' the register stack, if any non-call-used\n\ |
329 | registers are used in the function.\n\ |
330 | \n\ |
331 | @findex frame_pointer_needed\n\ |
332 | On machines where functions may or may not have frame-pointers, the\n\ |
333 | function entry code must vary accordingly; it must set up the frame\n\ |
334 | pointer if one is wanted, and not otherwise. To determine whether a\n\ |
335 | frame pointer is in wanted, the macro can refer to the variable\n\ |
336 | @code{frame_pointer_needed}. The variable's value will be 1 at run\n\ |
337 | time in a function that needs a frame pointer. @xref{Elimination}.\n\ |
338 | \n\ |
339 | The function entry code is responsible for allocating any stack space\n\ |
340 | required for the function. This stack space consists of the regions\n\ |
341 | listed below. In most cases, these regions are allocated in the\n\ |
342 | order listed, with the last listed region closest to the top of the\n\ |
343 | stack (the lowest address if @code{STACK_GROWS_DOWNWARD} is defined, and\n\ |
344 | the highest address if it is not defined). You can use a different order\n\ |
345 | for a machine if doing so is more convenient or required for\n\ |
346 | compatibility reasons. Except in cases where required by standard\n\ |
347 | or by a debugger, there is no reason why the stack layout used by GCC\n\ |
348 | need agree with that used by other compilers for a machine." , |
349 | void, (FILE *file), |
350 | default_function_pro_epilogue) |
351 | |
352 | /* Output the assembler code for end of prologue. */ |
353 | DEFHOOK |
354 | (function_end_prologue, |
355 | "If defined, a function that outputs assembler code at the end of a\n\ |
356 | prologue. This should be used when the function prologue is being\n\ |
357 | emitted as RTL, and you have some extra assembler that needs to be\n\ |
358 | emitted. @xref{prologue instruction pattern}." , |
359 | void, (FILE *file), |
360 | no_asm_to_stream) |
361 | |
362 | /* Output the assembler code for start of epilogue. */ |
363 | DEFHOOK |
364 | (function_begin_epilogue, |
365 | "If defined, a function that outputs assembler code at the start of an\n\ |
366 | epilogue. This should be used when the function epilogue is being\n\ |
367 | emitted as RTL, and you have some extra assembler that needs to be\n\ |
368 | emitted. @xref{epilogue instruction pattern}." , |
369 | void, (FILE *file), |
370 | no_asm_to_stream) |
371 | |
372 | /* Output the assembler code for function exit. */ |
373 | DEFHOOK |
374 | (function_epilogue, |
375 | "If defined, a function that outputs the assembler code for exit from a\n\ |
376 | function. The epilogue is responsible for restoring the saved\n\ |
377 | registers and stack pointer to their values when the function was\n\ |
378 | called, and returning control to the caller. This macro takes the\n\ |
379 | same argument as the macro @code{TARGET_ASM_FUNCTION_PROLOGUE}, and the\n\ |
380 | registers to restore are determined from @code{regs_ever_live} and\n\ |
381 | @code{CALL_USED_REGISTERS} in the same way.\n\ |
382 | \n\ |
383 | On some machines, there is a single instruction that does all the work\n\ |
384 | of returning from the function. On these machines, give that\n\ |
385 | instruction the name @samp{return} and do not define the macro\n\ |
386 | @code{TARGET_ASM_FUNCTION_EPILOGUE} at all.\n\ |
387 | \n\ |
388 | Do not define a pattern named @samp{return} if you want the\n\ |
389 | @code{TARGET_ASM_FUNCTION_EPILOGUE} to be used. If you want the target\n\ |
390 | switches to control whether return instructions or epilogues are used,\n\ |
391 | define a @samp{return} pattern with a validity condition that tests the\n\ |
392 | target switches appropriately. If the @samp{return} pattern's validity\n\ |
393 | condition is false, epilogues will be used.\n\ |
394 | \n\ |
395 | On machines where functions may or may not have frame-pointers, the\n\ |
396 | function exit code must vary accordingly. Sometimes the code for these\n\ |
397 | two cases is completely different. To determine whether a frame pointer\n\ |
398 | is wanted, the macro can refer to the variable\n\ |
399 | @code{frame_pointer_needed}. The variable's value will be 1 when compiling\n\ |
400 | a function that needs a frame pointer.\n\ |
401 | \n\ |
402 | Normally, @code{TARGET_ASM_FUNCTION_PROLOGUE} and\n\ |
403 | @code{TARGET_ASM_FUNCTION_EPILOGUE} must treat leaf functions specially.\n\ |
404 | The C variable @code{current_function_is_leaf} is nonzero for such a\n\ |
405 | function. @xref{Leaf Functions}.\n\ |
406 | \n\ |
407 | On some machines, some functions pop their arguments on exit while\n\ |
408 | others leave that for the caller to do. For example, the 68020 when\n\ |
409 | given @option{-mrtd} pops arguments in functions that take a fixed\n\ |
410 | number of arguments.\n\ |
411 | \n\ |
412 | @findex pops_args\n\ |
413 | @findex crtl->args.pops_args\n\ |
414 | Your definition of the macro @code{RETURN_POPS_ARGS} decides which\n\ |
415 | functions pop their own arguments. @code{TARGET_ASM_FUNCTION_EPILOGUE}\n\ |
416 | needs to know what was decided. The number of bytes of the current\n\ |
417 | function's arguments that this function should pop is available in\n\ |
418 | @code{crtl->args.pops_args}. @xref{Scalar Return}." , |
419 | void, (FILE *file), |
420 | default_function_pro_epilogue) |
421 | |
422 | /* Initialize target-specific sections. */ |
423 | DEFHOOK |
424 | (init_sections, |
425 | "Define this hook if you need to do something special to set up the\n\ |
426 | @file{varasm.cc} sections, or if your target has some special sections\n\ |
427 | of its own that you need to create.\n\ |
428 | \n\ |
429 | GCC calls this hook after processing the command line, but before writing\n\ |
430 | any assembly code, and before calling any of the section-returning hooks\n\ |
431 | described below." , |
432 | void, (void), |
433 | hook_void_void) |
434 | |
435 | /* Tell assembler to change to section NAME with attributes FLAGS. |
436 | If DECL is non-NULL, it is the VAR_DECL or FUNCTION_DECL with |
437 | which this section is associated. */ |
438 | DEFHOOK |
439 | (named_section, |
440 | "Output assembly directives to switch to section @var{name}. The section\n\ |
441 | should have attributes as specified by @var{flags}, which is a bit mask\n\ |
442 | of the @code{SECTION_*} flags defined in @file{output.h}. If @var{decl}\n\ |
443 | is non-NULL, it is the @code{VAR_DECL} or @code{FUNCTION_DECL} with which\n\ |
444 | this section is associated." , |
445 | void, (const char *name, unsigned int flags, tree decl), |
446 | default_no_named_section) |
447 | |
448 | /* Tell assembler what section attributes to assign this elf section |
449 | declaration, using their numerical value. */ |
450 | DEFHOOK |
451 | (elf_flags_numeric, |
452 | "This hook can be used to encode ELF section flags for which no letter\n\ |
453 | code has been defined in the assembler. It is called by\n\ |
454 | @code{default_asm_named_section} whenever the section flags need to be\n\ |
455 | emitted in the assembler output. If the hook returns true, then the\n\ |
456 | numerical value for ELF section flags should be calculated from\n\ |
457 | @var{flags} and saved in @var{*num}; the value is printed out instead of the\n\ |
458 | normal sequence of letter codes. If the hook is not defined, or if it\n\ |
459 | returns false, then @var{num} is ignored and the traditional letter sequence\n\ |
460 | is emitted." , |
461 | bool, (unsigned int flags, unsigned int *num), |
462 | hook_bool_uint_uintp_false) |
463 | |
464 | /* Return preferred text (sub)section for function DECL. |
465 | Main purpose of this function is to separate cold, normal and hot |
466 | functions. STARTUP is true when function is known to be used only |
467 | at startup (from static constructors or it is main()). |
468 | EXIT is true when function is known to be used only at exit |
469 | (from static destructors). |
470 | Return NULL if function should go to default text section. */ |
471 | DEFHOOK |
472 | (function_section, |
473 | "Return preferred text (sub)section for function @var{decl}.\n\ |
474 | Main purpose of this function is to separate cold, normal and hot\n\ |
475 | functions. @var{startup} is true when function is known to be used only\n\ |
476 | at startup (from static constructors or it is @code{main()}).\n\ |
477 | @var{exit} is true when function is known to be used only at exit\n\ |
478 | (from static destructors).\n\ |
479 | Return NULL if function should go to default text section." , |
480 | section *, (tree decl, enum node_frequency freq, bool startup, bool exit), |
481 | default_function_section) |
482 | |
483 | /* Output the assembler code for function exit. */ |
484 | DEFHOOK |
485 | (function_switched_text_sections, |
486 | "Used by the target to emit any assembler directives or additional\n\ |
487 | labels needed when a function is partitioned between different\n\ |
488 | sections. Output should be written to @var{file}. The function\n\ |
489 | decl is available as @var{decl} and the new section is `cold' if\n\ |
490 | @var{new_is_cold} is @code{true}." , |
491 | void, (FILE *file, tree decl, bool new_is_cold), |
492 | default_function_switched_text_sections) |
493 | |
494 | /* Return a mask describing how relocations should be treated when |
495 | selecting sections. Bit 1 should be set if global relocations |
496 | should be placed in a read-write section; bit 0 should be set if |
497 | local relocations should be placed in a read-write section. */ |
498 | DEFHOOK |
499 | (reloc_rw_mask, |
500 | "Return a mask describing how relocations should be treated when\n\ |
501 | selecting sections. Bit 1 should be set if global relocations\n\ |
502 | should be placed in a read-write section; bit 0 should be set if\n\ |
503 | local relocations should be placed in a read-write section.\n\ |
504 | \n\ |
505 | The default version of this function returns 3 when @option{-fpic}\n\ |
506 | is in effect, and 0 otherwise. The hook is typically redefined\n\ |
507 | when the target cannot support (some kinds of) dynamic relocations\n\ |
508 | in read-only sections even in executables." , |
509 | int, (void), |
510 | default_reloc_rw_mask) |
511 | |
512 | /* Return a flag for either generating ADDR_DIF_VEC table |
513 | or ADDR_VEC table for jumps in case of -fPIC/-fPIE. */ |
514 | DEFHOOK |
515 | (generate_pic_addr_diff_vec, |
516 | "Return true to generate ADDR_DIF_VEC table\n\ |
517 | or false to generate ADDR_VEC table for jumps in case of -fPIC.\n\ |
518 | \n\ |
519 | The default version of this function returns true if flag_pic\n\ |
520 | equals true and false otherwise" , |
521 | bool, (void), |
522 | default_generate_pic_addr_diff_vec) |
523 | |
524 | /* Return a section for EXP. It may be a DECL or a constant. RELOC |
525 | is nonzero if runtime relocations must be applied; bit 1 will be |
526 | set if the runtime relocations require non-local name resolution. |
527 | ALIGN is the required alignment of the data. */ |
528 | DEFHOOK |
529 | (select_section, |
530 | "Return the section into which @var{exp} should be placed. You can\n\ |
531 | assume that @var{exp} is either a @code{VAR_DECL} node or a constant of\n\ |
532 | some sort. @var{reloc} indicates whether the initial value of @var{exp}\n\ |
533 | requires link-time relocations. Bit 0 is set when variable contains\n\ |
534 | local relocations only, while bit 1 is set for global relocations.\n\ |
535 | @var{align} is the constant alignment in bits.\n\ |
536 | \n\ |
537 | The default version of this function takes care of putting read-only\n\ |
538 | variables in @code{readonly_data_section}.\n\ |
539 | \n\ |
540 | See also @var{USE_SELECT_SECTION_FOR_FUNCTIONS}." , |
541 | section *, (tree exp, int reloc, unsigned HOST_WIDE_INT align), |
542 | default_select_section) |
543 | |
544 | /* Return a section for X. MODE is X's mode and ALIGN is its |
545 | alignment in bits. */ |
546 | DEFHOOK |
547 | (select_rtx_section, |
548 | "Return the section into which a constant @var{x}, of mode @var{mode},\n\ |
549 | should be placed. You can assume that @var{x} is some kind of\n\ |
550 | constant in RTL@. The argument @var{mode} is redundant except in the\n\ |
551 | case of a @code{const_int} rtx. @var{align} is the constant alignment\n\ |
552 | in bits.\n\ |
553 | \n\ |
554 | The default version of this function takes care of putting symbolic\n\ |
555 | constants in @code{flag_pic} mode in @code{data_section} and everything\n\ |
556 | else in @code{readonly_data_section}." , |
557 | section *, (machine_mode mode, rtx x, unsigned HOST_WIDE_INT align), |
558 | default_select_rtx_section) |
559 | |
560 | /* Select a unique section name for DECL. RELOC is the same as |
561 | for SELECT_SECTION. */ |
562 | DEFHOOK |
563 | (unique_section, |
564 | "Build up a unique section name, expressed as a @code{STRING_CST} node,\n\ |
565 | and assign it to @samp{DECL_SECTION_NAME (@var{decl})}.\n\ |
566 | As with @code{TARGET_ASM_SELECT_SECTION}, @var{reloc} indicates whether\n\ |
567 | the initial value of @var{exp} requires link-time relocations.\n\ |
568 | \n\ |
569 | The default version of this function appends the symbol name to the\n\ |
570 | ELF section name that would normally be used for the symbol. For\n\ |
571 | example, the function @code{foo} would be placed in @code{.text.foo}.\n\ |
572 | Whatever the actual target object format, this is often good enough." , |
573 | void, (tree decl, int reloc), |
574 | default_unique_section) |
575 | |
576 | /* Return the readonly data or relocated readonly data section |
577 | associated with function DECL. */ |
578 | DEFHOOK |
579 | (function_rodata_section, |
580 | "Return the readonly data or reloc readonly data section associated with\n\ |
581 | @samp{DECL_SECTION_NAME (@var{decl})}. @var{relocatable} selects the latter\n\ |
582 | over the former.\n\ |
583 | The default version of this function selects @code{.gnu.linkonce.r.name} if\n\ |
584 | the function's section is @code{.gnu.linkonce.t.name}, @code{.rodata.name}\n\ |
585 | or @code{.data.rel.ro.name} if function is in @code{.text.name}, and\n\ |
586 | the normal readonly-data or reloc readonly data section otherwise." , |
587 | section *, (tree decl, bool relocatable), |
588 | default_function_rodata_section) |
589 | |
590 | /* Nonnull if the target wants to override the default ".rodata" prefix |
591 | for mergeable data sections. */ |
592 | DEFHOOKPOD |
593 | (mergeable_rodata_prefix, |
594 | "Usually, the compiler uses the prefix @code{\".rodata\"} to construct\n\ |
595 | section names for mergeable constant data. Define this macro to override\n\ |
596 | the string if a different section name should be used." , |
597 | const char *, ".rodata" ) |
598 | |
599 | /* Return the section to be used for transactional memory clone tables. */ |
600 | DEFHOOK |
601 | (tm_clone_table_section, |
602 | "Return the section that should be used for transactional memory clone\n\ |
603 | tables." , |
604 | section *, (void), default_clone_table_section) |
605 | |
606 | /* Output a constructor for a symbol with a given priority. */ |
607 | DEFHOOK |
608 | (constructor, |
609 | "If defined, a function that outputs assembler code to arrange to call\n\ |
610 | the function referenced by @var{symbol} at initialization time.\n\ |
611 | \n\ |
612 | Assume that @var{symbol} is a @code{SYMBOL_REF} for a function taking\n\ |
613 | no arguments and with no return value. If the target supports initialization\n\ |
614 | priorities, @var{priority} is a value between 0 and @code{MAX_INIT_PRIORITY};\n\ |
615 | otherwise it must be @code{DEFAULT_INIT_PRIORITY}.\n\ |
616 | \n\ |
617 | If this macro is not defined by the target, a suitable default will\n\ |
618 | be chosen if (1) the target supports arbitrary section names, (2) the\n\ |
619 | target defines @code{CTORS_SECTION_ASM_OP}, or (3) @code{USE_COLLECT2}\n\ |
620 | is not defined." , |
621 | void, (rtx symbol, int priority), NULL) |
622 | |
623 | /* Output a destructor for a symbol with a given priority. */ |
624 | DEFHOOK |
625 | (destructor, |
626 | "This is like @code{TARGET_ASM_CONSTRUCTOR} but used for termination\n\ |
627 | functions rather than initialization functions." , |
628 | void, (rtx symbol, int priority), NULL) |
629 | |
630 | /* Output the assembler code for a thunk function. THUNK_DECL is the |
631 | declaration for the thunk function itself, FUNCTION is the decl for |
632 | the target function. DELTA is an immediate constant offset to be |
633 | added to THIS. If VCALL_OFFSET is nonzero, the word at |
634 | *(*this + vcall_offset) should be added to THIS. */ |
635 | DEFHOOK |
636 | (output_mi_thunk, |
637 | "A function that outputs the assembler code for a thunk\n\ |
638 | function, used to implement C++ virtual function calls with multiple\n\ |
639 | inheritance. The thunk acts as a wrapper around a virtual function,\n\ |
640 | adjusting the implicit object parameter before handing control off to\n\ |
641 | the real function.\n\ |
642 | \n\ |
643 | First, emit code to add the integer @var{delta} to the location that\n\ |
644 | contains the incoming first argument. Assume that this argument\n\ |
645 | contains a pointer, and is the one used to pass the @code{this} pointer\n\ |
646 | in C++. This is the incoming argument @emph{before} the function prologue,\n\ |
647 | e.g.@: @samp{%o0} on a sparc. The addition must preserve the values of\n\ |
648 | all other incoming arguments.\n\ |
649 | \n\ |
650 | Then, if @var{vcall_offset} is nonzero, an additional adjustment should be\n\ |
651 | made after adding @code{delta}. In particular, if @var{p} is the\n\ |
652 | adjusted pointer, the following adjustment should be made:\n\ |
653 | \n\ |
654 | @smallexample\n\ |
655 | p += (*((ptrdiff_t **)p))[vcall_offset/sizeof(ptrdiff_t)]\n\ |
656 | @end smallexample\n\ |
657 | \n\ |
658 | After the additions, emit code to jump to @var{function}, which is a\n\ |
659 | @code{FUNCTION_DECL}. This is a direct pure jump, not a call, and does\n\ |
660 | not touch the return address. Hence returning from @var{FUNCTION} will\n\ |
661 | return to whoever called the current @samp{thunk}.\n\ |
662 | \n\ |
663 | The effect must be as if @var{function} had been called directly with\n\ |
664 | the adjusted first argument. This macro is responsible for emitting all\n\ |
665 | of the code for a thunk function; @code{TARGET_ASM_FUNCTION_PROLOGUE}\n\ |
666 | and @code{TARGET_ASM_FUNCTION_EPILOGUE} are not invoked.\n\ |
667 | \n\ |
668 | The @var{thunk_fndecl} is redundant. (@var{delta} and @var{function}\n\ |
669 | have already been extracted from it.) It might possibly be useful on\n\ |
670 | some targets, but probably not.\n\ |
671 | \n\ |
672 | If you do not define this macro, the target-independent code in the C++\n\ |
673 | front end will generate a less efficient heavyweight thunk that calls\n\ |
674 | @var{function} instead of jumping to it. The generic approach does\n\ |
675 | not support varargs." , |
676 | void, (FILE *file, tree thunk_fndecl, HOST_WIDE_INT delta, |
677 | HOST_WIDE_INT vcall_offset, tree function), |
678 | NULL) |
679 | |
680 | /* Determine whether output_mi_thunk would succeed. */ |
681 | /* ??? Ideally, this hook would not exist, and success or failure |
682 | would be returned from output_mi_thunk directly. But there's |
683 | too much undo-able setup involved in invoking output_mi_thunk. |
684 | Could be fixed by making output_mi_thunk emit rtl instead of |
685 | text to the output file. */ |
686 | DEFHOOK |
687 | (can_output_mi_thunk, |
688 | "A function that returns true if TARGET_ASM_OUTPUT_MI_THUNK would be able\n\ |
689 | to output the assembler code for the thunk function specified by the\n\ |
690 | arguments it is passed, and false otherwise. In the latter case, the\n\ |
691 | generic approach will be used by the C++ front end, with the limitations\n\ |
692 | previously exposed." , |
693 | bool, (const_tree thunk_fndecl, HOST_WIDE_INT delta, |
694 | HOST_WIDE_INT vcall_offset, const_tree function), |
695 | hook_bool_const_tree_hwi_hwi_const_tree_false) |
696 | |
697 | /* Output any boilerplate text needed at the beginning of a |
698 | translation unit. */ |
699 | DEFHOOK |
700 | (file_start, |
701 | "Output to @code{asm_out_file} any text which the assembler expects to\n\ |
702 | find at the beginning of a file. The default behavior is controlled\n\ |
703 | by two flags, documented below. Unless your target's assembler is\n\ |
704 | quite unusual, if you override the default, you should call\n\ |
705 | @code{default_file_start} at some point in your target hook. This\n\ |
706 | lets other target files rely on these variables." , |
707 | void, (void), |
708 | default_file_start) |
709 | |
710 | /* Output any boilerplate text needed at the end of a translation unit. */ |
711 | DEFHOOK |
712 | (file_end, |
713 | "Output to @code{asm_out_file} any text which the assembler expects\n\ |
714 | to find at the end of a file. The default is to output nothing." , |
715 | void, (void), |
716 | hook_void_void) |
717 | |
718 | /* Output any boilerplate text needed at the beginning of an |
719 | LTO output stream. */ |
720 | DEFHOOK |
721 | (lto_start, |
722 | "Output to @code{asm_out_file} any text which the assembler expects\n\ |
723 | to find at the start of an LTO section. The default is to output\n\ |
724 | nothing." , |
725 | void, (void), |
726 | hook_void_void) |
727 | |
728 | /* Output any boilerplate text needed at the end of an |
729 | LTO output stream. */ |
730 | DEFHOOK |
731 | (lto_end, |
732 | "Output to @code{asm_out_file} any text which the assembler expects\n\ |
733 | to find at the end of an LTO section. The default is to output\n\ |
734 | nothing." , |
735 | void, (void), |
736 | hook_void_void) |
737 | |
738 | /* Output any boilerplace text needed at the end of a |
739 | translation unit before debug and unwind info is emitted. */ |
740 | DEFHOOK |
741 | (code_end, |
742 | "Output to @code{asm_out_file} any text which is needed before emitting\n\ |
743 | unwind info and debug info at the end of a file. Some targets emit\n\ |
744 | here PIC setup thunks that cannot be emitted at the end of file,\n\ |
745 | because they couldn't have unwind info then. The default is to output\n\ |
746 | nothing." , |
747 | void, (void), |
748 | hook_void_void) |
749 | |
750 | /* Output an assembler pseudo-op to declare a library function name |
751 | external. */ |
752 | DEFHOOK |
753 | (external_libcall, |
754 | "This target hook is a function to output to @var{asm_out_file} an assembler\n\ |
755 | pseudo-op to declare a library function name external. The name of the\n\ |
756 | library function is given by @var{symref}, which is a @code{symbol_ref}." , |
757 | void, (rtx symref), |
758 | default_external_libcall) |
759 | |
760 | /* Output an assembler directive to mark decl live. This instructs |
761 | linker to not dead code strip this symbol. */ |
762 | DEFHOOK |
763 | (mark_decl_preserved, |
764 | "This target hook is a function to output to @var{asm_out_file} an assembler\n\ |
765 | directive to annotate @var{symbol} as used. The Darwin target uses the\n\ |
766 | .no_dead_code_strip directive." , |
767 | void, (const char *symbol), |
768 | hook_void_constcharptr) |
769 | |
770 | /* Output a record of the command line switches that have been passed. */ |
771 | DEFHOOK |
772 | (record_gcc_switches, |
773 | "Provides the target with the ability to record the gcc command line\n\ |
774 | switches provided as argument.\n\ |
775 | \n\ |
776 | By default this hook is set to NULL, but an example implementation is\n\ |
777 | provided for ELF based targets. Called @var{elf_record_gcc_switches},\n\ |
778 | it records the switches as ASCII text inside a new, string mergeable\n\ |
779 | section in the assembler output file. The name of the new section is\n\ |
780 | provided by the @code{TARGET_ASM_RECORD_GCC_SWITCHES_SECTION} target\n\ |
781 | hook." , |
782 | void, (const char *), |
783 | NULL) |
784 | |
785 | /* The name of the section that the example ELF implementation of |
786 | record_gcc_switches will use to store the information. Target |
787 | specific versions of record_gcc_switches may or may not use |
788 | this information. */ |
789 | DEFHOOKPOD |
790 | (record_gcc_switches_section, |
791 | "This is the name of the section that will be created by the example\n\ |
792 | ELF implementation of the @code{TARGET_ASM_RECORD_GCC_SWITCHES} target\n\ |
793 | hook." , |
794 | const char *, ".GCC.command.line" ) |
795 | |
796 | /* Output the definition of a section anchor. */ |
797 | DEFHOOK |
798 | (output_anchor, |
799 | "Write the assembly code to define section anchor @var{x}, which is a\n\ |
800 | @code{SYMBOL_REF} for which @samp{SYMBOL_REF_ANCHOR_P (@var{x})} is true.\n\ |
801 | The hook is called with the assembly output position set to the beginning\n\ |
802 | of @code{SYMBOL_REF_BLOCK (@var{x})}.\n\ |
803 | \n\ |
804 | If @code{ASM_OUTPUT_DEF} is available, the hook's default definition uses\n\ |
805 | it to define the symbol as @samp{. + SYMBOL_REF_BLOCK_OFFSET (@var{x})}.\n\ |
806 | If @code{ASM_OUTPUT_DEF} is not available, the hook's default definition\n\ |
807 | is @code{NULL}, which disables the use of section anchors altogether." , |
808 | void, (rtx x), |
809 | default_asm_output_anchor) |
810 | |
811 | DEFHOOK |
812 | (output_ident, |
813 | "Output a string based on @var{name}, suitable for the @samp{#ident}\n\ |
814 | directive, or the equivalent directive or pragma in non-C-family languages.\n\ |
815 | If this hook is not defined, nothing is output for the @samp{#ident}\n\ |
816 | directive." , |
817 | void, (const char *name), |
818 | hook_void_constcharptr) |
819 | |
820 | /* Output a DTP-relative reference to a TLS symbol. */ |
821 | DEFHOOK |
822 | (output_dwarf_dtprel, |
823 | "If defined, this target hook is a function which outputs a DTP-relative\n\ |
824 | reference to the given TLS symbol of the specified size." , |
825 | void, (FILE *file, int size, rtx x), |
826 | NULL) |
827 | |
828 | /* Some target machines need to postscan each insn after it is output. */ |
829 | DEFHOOK |
830 | (final_postscan_insn, |
831 | "If defined, this target hook is a function which is executed just after the\n\ |
832 | output of assembler code for @var{insn}, to change the mode of the assembler\n\ |
833 | if necessary.\n\ |
834 | \n\ |
835 | Here the argument @var{opvec} is the vector containing the operands\n\ |
836 | extracted from @var{insn}, and @var{noperands} is the number of\n\ |
837 | elements of the vector which contain meaningful data for this insn.\n\ |
838 | The contents of this vector are what was used to convert the insn\n\ |
839 | template into assembler code, so you can change the assembler mode\n\ |
840 | by checking the contents of the vector." , |
841 | void, (FILE *file, rtx_insn *insn, rtx *opvec, int noperands), |
842 | NULL) |
843 | |
844 | /* Emit the trampoline template. This hook may be NULL. */ |
845 | DEFHOOK |
846 | (trampoline_template, |
847 | "This hook is called by @code{assemble_trampoline_template} to output,\n\ |
848 | on the stream @var{f}, assembler code for a block of data that contains\n\ |
849 | the constant parts of a trampoline. This code should not include a\n\ |
850 | label---the label is taken care of automatically.\n\ |
851 | \n\ |
852 | If you do not define this hook, it means no template is needed\n\ |
853 | for the target. Do not define this hook on systems where the block move\n\ |
854 | code to copy the trampoline into place would be larger than the code\n\ |
855 | to generate it on the spot." , |
856 | void, (FILE *f), |
857 | NULL) |
858 | |
859 | DEFHOOK |
860 | (output_source_filename, |
861 | "Output DWARF debugging information which indicates that filename\n\ |
862 | @var{name} is the current source file to the stdio stream @var{file}.\n\ |
863 | \n\ |
864 | This target hook need not be defined if the standard form of output\n\ |
865 | for the file format in use is appropriate." , |
866 | void ,(FILE *file, const char *name), |
867 | default_asm_output_source_filename) |
868 | |
869 | DEFHOOK |
870 | (, |
871 | "A target hook to recognize @var{rtx} patterns that @code{output_addr_const}\n\ |
872 | can't deal with, and output assembly code to @var{file} corresponding to\n\ |
873 | the pattern @var{x}. This may be used to allow machine-dependent\n\ |
874 | @code{UNSPEC}s to appear within constants.\n\ |
875 | \n\ |
876 | If target hook fails to recognize a pattern, it must return @code{false},\n\ |
877 | so that a standard error message is printed. If it prints an error message\n\ |
878 | itself, by calling, for example, @code{output_operand_lossage}, it may just\n\ |
879 | return @code{true}." , |
880 | bool, (FILE *file, rtx x), |
881 | hook_bool_FILEptr_rtx_false) |
882 | |
883 | /* ??? The TARGET_PRINT_OPERAND* hooks are part of the asm_out struct, |
884 | even though that is not reflected in the macro name to override their |
885 | initializers. */ |
886 | #undef HOOK_PREFIX |
887 | #define HOOK_PREFIX "TARGET_" |
888 | |
889 | /* Emit a machine-specific insn operand. */ |
890 | /* ??? tm.texi only documents the old macro PRINT_OPERAND, |
891 | not this hook, and uses a different name for the argument FILE. */ |
892 | DEFHOOK_UNDOC |
893 | (print_operand, |
894 | "" , |
895 | void, (FILE *file, rtx x, int code), |
896 | default_print_operand) |
897 | |
898 | /* Emit a machine-specific memory address. */ |
899 | /* ??? tm.texi only documents the old macro PRINT_OPERAND_ADDRESS, |
900 | not this hook, and uses different argument names. */ |
901 | DEFHOOK_UNDOC |
902 | (print_operand_address, |
903 | "" , |
904 | void, (FILE *file, machine_mode mode, rtx addr), |
905 | default_print_operand_address) |
906 | |
907 | /* Determine whether CODE is a valid punctuation character for the |
908 | `print_operand' hook. */ |
909 | /* ??? tm.texi only documents the old macro PRINT_OPERAND_PUNCT_VALID_P, |
910 | not this hook. */ |
911 | DEFHOOK_UNDOC |
912 | (print_operand_punct_valid_p, |
913 | "" , |
914 | bool ,(unsigned char code), |
915 | default_print_operand_punct_valid_p) |
916 | |
917 | /* Given a symbol name, perform same mangling as assemble_name and |
918 | ASM_OUTPUT_LABELREF, returning result as an IDENTIFIER_NODE. */ |
919 | DEFHOOK |
920 | (mangle_assembler_name, |
921 | "Given a symbol @var{name}, perform same mangling as @code{varasm.cc}'s\n\ |
922 | @code{assemble_name}, but in memory rather than to a file stream, returning\n\ |
923 | result as an @code{IDENTIFIER_NODE}. Required for correct LTO symtabs. The\n\ |
924 | default implementation calls the @code{TARGET_STRIP_NAME_ENCODING} hook and\n\ |
925 | then prepends the @code{USER_LABEL_PREFIX}, if any." , |
926 | tree, (const char *name), |
927 | default_mangle_assembler_name) |
928 | |
929 | HOOK_VECTOR_END (asm_out) |
930 | |
931 | /* Functions relating to instruction scheduling. All of these |
932 | default to null pointers, which haifa-sched.cc looks for and handles. */ |
933 | #undef HOOK_PREFIX |
934 | #define HOOK_PREFIX "TARGET_SCHED_" |
935 | HOOK_VECTOR (TARGET_SCHED, sched) |
936 | |
937 | /* Given the current cost, COST, of an insn, INSN, calculate and |
938 | return a new cost based on its relationship to DEP_INSN through |
939 | the dependence LINK. The default is to make no adjustment. */ |
940 | DEFHOOK |
941 | (adjust_cost, |
942 | "This function corrects the value of @var{cost} based on the\n\ |
943 | relationship between @var{insn} and @var{dep_insn} through a\n\ |
944 | dependence of type dep_type, and strength @var{dw}. It should return the new\n\ |
945 | value. The default is to make no adjustment to @var{cost}. This can be\n\ |
946 | used for example to specify to the scheduler using the traditional pipeline\n\ |
947 | description that an output- or anti-dependence does not incur the same cost\n\ |
948 | as a data-dependence. If the scheduler using the automaton based pipeline\n\ |
949 | description, the cost of anti-dependence is zero and the cost of\n\ |
950 | output-dependence is maximum of one and the difference of latency\n\ |
951 | times of the first and the second insns. If these values are not\n\ |
952 | acceptable, you could use the hook to modify them too. See also\n\ |
953 | @pxref{Processor pipeline description}." , |
954 | int, (rtx_insn *insn, int dep_type1, rtx_insn *dep_insn, int cost, |
955 | unsigned int dw), |
956 | NULL) |
957 | |
958 | /* Adjust the priority of an insn as you see fit. Returns the new priority. */ |
959 | DEFHOOK |
960 | (adjust_priority, |
961 | "This hook adjusts the integer scheduling priority @var{priority} of\n\ |
962 | @var{insn}. It should return the new priority. Increase the priority to\n\ |
963 | execute @var{insn} earlier, reduce the priority to execute @var{insn}\n\ |
964 | later. Do not define this hook if you do not need to adjust the\n\ |
965 | scheduling priorities of insns." , |
966 | int, (rtx_insn *insn, int priority), NULL) |
967 | |
968 | /* Function which returns the maximum number of insns that can be |
969 | scheduled in the same machine cycle. This must be constant |
970 | over an entire compilation. The default is 1. */ |
971 | DEFHOOK |
972 | (issue_rate, |
973 | "This hook returns the maximum number of instructions that can ever\n\ |
974 | issue at the same time on the target machine. The default is one.\n\ |
975 | Although the insn scheduler can define itself the possibility of issue\n\ |
976 | an insn on the same cycle, the value can serve as an additional\n\ |
977 | constraint to issue insns on the same simulated processor cycle (see\n\ |
978 | hooks @samp{TARGET_SCHED_REORDER} and @samp{TARGET_SCHED_REORDER2}).\n\ |
979 | This value must be constant over the entire compilation. If you need\n\ |
980 | it to vary depending on what the instructions are, you must use\n\ |
981 | @samp{TARGET_SCHED_VARIABLE_ISSUE}." , |
982 | int, (void), NULL) |
983 | |
984 | /* Calculate how much this insn affects how many more insns we |
985 | can emit this cycle. Default is they all cost the same. */ |
986 | DEFHOOK |
987 | (variable_issue, |
988 | "This hook is executed by the scheduler after it has scheduled an insn\n\ |
989 | from the ready list. It should return the number of insns which can\n\ |
990 | still be issued in the current cycle. The default is\n\ |
991 | @samp{@w{@var{more} - 1}} for insns other than @code{CLOBBER} and\n\ |
992 | @code{USE}, which normally are not counted against the issue rate.\n\ |
993 | You should define this hook if some insns take more machine resources\n\ |
994 | than others, so that fewer insns can follow them in the same cycle.\n\ |
995 | @var{file} is either a null pointer, or a stdio stream to write any\n\ |
996 | debug output to. @var{verbose} is the verbose level provided by\n\ |
997 | @option{-fsched-verbose-@var{n}}. @var{insn} is the instruction that\n\ |
998 | was scheduled." , |
999 | int, (FILE *file, int verbose, rtx_insn *insn, int more), NULL) |
1000 | |
1001 | /* Initialize machine-dependent scheduling code. */ |
1002 | DEFHOOK |
1003 | (init, |
1004 | "This hook is executed by the scheduler at the beginning of each block of\n\ |
1005 | instructions that are to be scheduled. @var{file} is either a null\n\ |
1006 | pointer, or a stdio stream to write any debug output to. @var{verbose}\n\ |
1007 | is the verbose level provided by @option{-fsched-verbose-@var{n}}.\n\ |
1008 | @var{max_ready} is the maximum number of insns in the current scheduling\n\ |
1009 | region that can be live at the same time. This can be used to allocate\n\ |
1010 | scratch space if it is needed, e.g.@: by @samp{TARGET_SCHED_REORDER}." , |
1011 | void, (FILE *file, int verbose, int max_ready), NULL) |
1012 | |
1013 | /* Finalize machine-dependent scheduling code. */ |
1014 | DEFHOOK |
1015 | (finish, |
1016 | "This hook is executed by the scheduler at the end of each block of\n\ |
1017 | instructions that are to be scheduled. It can be used to perform\n\ |
1018 | cleanup of any actions done by the other scheduling hooks. @var{file}\n\ |
1019 | is either a null pointer, or a stdio stream to write any debug output\n\ |
1020 | to. @var{verbose} is the verbose level provided by\n\ |
1021 | @option{-fsched-verbose-@var{n}}." , |
1022 | void, (FILE *file, int verbose), NULL) |
1023 | |
1024 | /* Initialize machine-dependent function wide scheduling code. */ |
1025 | DEFHOOK |
1026 | (init_global, |
1027 | "This hook is executed by the scheduler after function level initializations.\n\ |
1028 | @var{file} is either a null pointer, or a stdio stream to write any debug output to.\n\ |
1029 | @var{verbose} is the verbose level provided by @option{-fsched-verbose-@var{n}}.\n\ |
1030 | @var{old_max_uid} is the maximum insn uid when scheduling begins." , |
1031 | void, (FILE *file, int verbose, int old_max_uid), NULL) |
1032 | |
1033 | /* Finalize machine-dependent function wide scheduling code. */ |
1034 | DEFHOOK |
1035 | (finish_global, |
1036 | "This is the cleanup hook corresponding to @code{TARGET_SCHED_INIT_GLOBAL}.\n\ |
1037 | @var{file} is either a null pointer, or a stdio stream to write any debug output to.\n\ |
1038 | @var{verbose} is the verbose level provided by @option{-fsched-verbose-@var{n}}." , |
1039 | void, (FILE *file, int verbose), NULL) |
1040 | |
1041 | /* Reorder insns in a machine-dependent fashion, in two different |
1042 | places. Default does nothing. */ |
1043 | DEFHOOK |
1044 | (reorder, |
1045 | "This hook is executed by the scheduler after it has scheduled the ready\n\ |
1046 | list, to allow the machine description to reorder it (for example to\n\ |
1047 | combine two small instructions together on @samp{VLIW} machines).\n\ |
1048 | @var{file} is either a null pointer, or a stdio stream to write any\n\ |
1049 | debug output to. @var{verbose} is the verbose level provided by\n\ |
1050 | @option{-fsched-verbose-@var{n}}. @var{ready} is a pointer to the ready\n\ |
1051 | list of instructions that are ready to be scheduled. @var{n_readyp} is\n\ |
1052 | a pointer to the number of elements in the ready list. The scheduler\n\ |
1053 | reads the ready list in reverse order, starting with\n\ |
1054 | @var{ready}[@var{*n_readyp} @minus{} 1] and going to @var{ready}[0]. @var{clock}\n\ |
1055 | is the timer tick of the scheduler. You may modify the ready list and\n\ |
1056 | the number of ready insns. The return value is the number of insns that\n\ |
1057 | can issue this cycle; normally this is just @code{issue_rate}. See also\n\ |
1058 | @samp{TARGET_SCHED_REORDER2}." , |
1059 | int, (FILE *file, int verbose, rtx_insn **ready, int *n_readyp, int clock), NULL) |
1060 | |
1061 | DEFHOOK |
1062 | (reorder2, |
1063 | "Like @samp{TARGET_SCHED_REORDER}, but called at a different time. That\n\ |
1064 | function is called whenever the scheduler starts a new cycle. This one\n\ |
1065 | is called once per iteration over a cycle, immediately after\n\ |
1066 | @samp{TARGET_SCHED_VARIABLE_ISSUE}; it can reorder the ready list and\n\ |
1067 | return the number of insns to be scheduled in the same cycle. Defining\n\ |
1068 | this hook can be useful if there are frequent situations where\n\ |
1069 | scheduling one insn causes other insns to become ready in the same\n\ |
1070 | cycle. These other insns can then be taken into account properly." , |
1071 | int, (FILE *file, int verbose, rtx_insn **ready, int *n_readyp, int clock), NULL) |
1072 | |
1073 | DEFHOOK |
1074 | (macro_fusion_p, |
1075 | "This hook is used to check whether target platform supports macro fusion." , |
1076 | bool, (void), NULL) |
1077 | |
1078 | DEFHOOK |
1079 | (macro_fusion_pair_p, |
1080 | "This hook is used to check whether two insns should be macro fused for\n\ |
1081 | a target microarchitecture. If this hook returns true for the given insn pair\n\ |
1082 | (@var{prev} and @var{curr}), the scheduler will put them into a sched\n\ |
1083 | group, and they will not be scheduled apart. The two insns will be either\n\ |
1084 | two SET insns or a compare and a conditional jump and this hook should\n\ |
1085 | validate any dependencies needed to fuse the two insns together." , |
1086 | bool, (rtx_insn *prev, rtx_insn *curr), NULL) |
1087 | |
1088 | /* The following member value is a pointer to a function called |
1089 | after evaluation forward dependencies of insns in chain given |
1090 | by two parameter values (head and tail correspondingly). */ |
1091 | DEFHOOK |
1092 | (dependencies_evaluation_hook, |
1093 | "This hook is called after evaluation forward dependencies of insns in\n\ |
1094 | chain given by two parameter values (@var{head} and @var{tail}\n\ |
1095 | correspondingly) but before insns scheduling of the insn chain. For\n\ |
1096 | example, it can be used for better insn classification if it requires\n\ |
1097 | analysis of dependencies. This hook can use backward and forward\n\ |
1098 | dependencies of the insn scheduler because they are already\n\ |
1099 | calculated." , |
1100 | void, (rtx_insn *head, rtx_insn *tail), NULL) |
1101 | |
1102 | /* The values of the following four members are pointers to functions |
1103 | used to simplify the automaton descriptions. dfa_pre_cycle_insn and |
1104 | dfa_post_cycle_insn give functions returning insns which are used to |
1105 | change the pipeline hazard recognizer state when the new simulated |
1106 | processor cycle correspondingly starts and finishes. The function |
1107 | defined by init_dfa_pre_cycle_insn and init_dfa_post_cycle_insn are |
1108 | used to initialize the corresponding insns. The default values of |
1109 | the members result in not changing the automaton state when the |
1110 | new simulated processor cycle correspondingly starts and finishes. */ |
1111 | |
1112 | DEFHOOK |
1113 | (init_dfa_pre_cycle_insn, |
1114 | "The hook can be used to initialize data used by the previous hook." , |
1115 | void, (void), NULL) |
1116 | |
1117 | DEFHOOK |
1118 | (dfa_pre_cycle_insn, |
1119 | "The hook returns an RTL insn. The automaton state used in the\n\ |
1120 | pipeline hazard recognizer is changed as if the insn were scheduled\n\ |
1121 | when the new simulated processor cycle starts. Usage of the hook may\n\ |
1122 | simplify the automaton pipeline description for some @acronym{VLIW}\n\ |
1123 | processors. If the hook is defined, it is used only for the automaton\n\ |
1124 | based pipeline description. The default is not to change the state\n\ |
1125 | when the new simulated processor cycle starts." , |
1126 | rtx, (void), NULL) |
1127 | |
1128 | DEFHOOK |
1129 | (init_dfa_post_cycle_insn, |
1130 | "The hook is analogous to @samp{TARGET_SCHED_INIT_DFA_PRE_CYCLE_INSN} but\n\ |
1131 | used to initialize data used by the previous hook." , |
1132 | void, (void), NULL) |
1133 | |
1134 | DEFHOOK |
1135 | (dfa_post_cycle_insn, |
1136 | "The hook is analogous to @samp{TARGET_SCHED_DFA_PRE_CYCLE_INSN} but used\n\ |
1137 | to changed the state as if the insn were scheduled when the new\n\ |
1138 | simulated processor cycle finishes." , |
1139 | rtx_insn *, (void), NULL) |
1140 | |
1141 | /* The values of the following two members are pointers to |
1142 | functions used to simplify the automaton descriptions. |
1143 | dfa_pre_advance_cycle and dfa_post_advance_cycle are getting called |
1144 | immediately before and after cycle is advanced. */ |
1145 | |
1146 | DEFHOOK |
1147 | (dfa_pre_advance_cycle, |
1148 | "The hook to notify target that the current simulated cycle is about to finish.\n\ |
1149 | The hook is analogous to @samp{TARGET_SCHED_DFA_PRE_CYCLE_INSN} but used\n\ |
1150 | to change the state in more complicated situations - e.g., when advancing\n\ |
1151 | state on a single insn is not enough." , |
1152 | void, (void), NULL) |
1153 | |
1154 | DEFHOOK |
1155 | (dfa_post_advance_cycle, |
1156 | "The hook to notify target that new simulated cycle has just started.\n\ |
1157 | The hook is analogous to @samp{TARGET_SCHED_DFA_POST_CYCLE_INSN} but used\n\ |
1158 | to change the state in more complicated situations - e.g., when advancing\n\ |
1159 | state on a single insn is not enough." , |
1160 | void, (void), NULL) |
1161 | |
1162 | /* The following member value is a pointer to a function returning value |
1163 | which defines how many insns in queue `ready' will we try for |
1164 | multi-pass scheduling. If the member value is nonzero and the |
1165 | function returns positive value, the DFA based scheduler will make |
1166 | multi-pass scheduling for the first cycle. In other words, we will |
1167 | try to choose ready insn which permits to start maximum number of |
1168 | insns on the same cycle. */ |
1169 | DEFHOOK |
1170 | (first_cycle_multipass_dfa_lookahead, |
1171 | "This hook controls better choosing an insn from the ready insn queue\n\ |
1172 | for the @acronym{DFA}-based insn scheduler. Usually the scheduler\n\ |
1173 | chooses the first insn from the queue. If the hook returns a positive\n\ |
1174 | value, an additional scheduler code tries all permutations of\n\ |
1175 | @samp{TARGET_SCHED_FIRST_CYCLE_MULTIPASS_DFA_LOOKAHEAD ()}\n\ |
1176 | subsequent ready insns to choose an insn whose issue will result in\n\ |
1177 | maximal number of issued insns on the same cycle. For the\n\ |
1178 | @acronym{VLIW} processor, the code could actually solve the problem of\n\ |
1179 | packing simple insns into the @acronym{VLIW} insn. Of course, if the\n\ |
1180 | rules of @acronym{VLIW} packing are described in the automaton.\n\ |
1181 | \n\ |
1182 | This code also could be used for superscalar @acronym{RISC}\n\ |
1183 | processors. Let us consider a superscalar @acronym{RISC} processor\n\ |
1184 | with 3 pipelines. Some insns can be executed in pipelines @var{A} or\n\ |
1185 | @var{B}, some insns can be executed only in pipelines @var{B} or\n\ |
1186 | @var{C}, and one insn can be executed in pipeline @var{B}. The\n\ |
1187 | processor may issue the 1st insn into @var{A} and the 2nd one into\n\ |
1188 | @var{B}. In this case, the 3rd insn will wait for freeing @var{B}\n\ |
1189 | until the next cycle. If the scheduler issues the 3rd insn the first,\n\ |
1190 | the processor could issue all 3 insns per cycle.\n\ |
1191 | \n\ |
1192 | Actually this code demonstrates advantages of the automaton based\n\ |
1193 | pipeline hazard recognizer. We try quickly and easy many insn\n\ |
1194 | schedules to choose the best one.\n\ |
1195 | \n\ |
1196 | The default is no multipass scheduling." , |
1197 | int, (void), NULL) |
1198 | |
1199 | /* The following member value is pointer to a function controlling |
1200 | what insns from the ready insn queue will be considered for the |
1201 | multipass insn scheduling. If the hook returns zero for insn |
1202 | passed as the parameter, the insn will be not chosen to be issued. */ |
1203 | DEFHOOK |
1204 | (first_cycle_multipass_dfa_lookahead_guard, |
1205 | "\n\ |
1206 | This hook controls what insns from the ready insn queue will be\n\ |
1207 | considered for the multipass insn scheduling. If the hook returns\n\ |
1208 | zero for @var{insn}, the insn will be considered in multipass scheduling.\n\ |
1209 | Positive return values will remove @var{insn} from consideration on\n\ |
1210 | the current round of multipass scheduling.\n\ |
1211 | Negative return values will remove @var{insn} from consideration for given\n\ |
1212 | number of cycles.\n\ |
1213 | Backends should be careful about returning non-zero for highest priority\n\ |
1214 | instruction at position 0 in the ready list. @var{ready_index} is passed\n\ |
1215 | to allow backends make correct judgements.\n\ |
1216 | \n\ |
1217 | The default is that any ready insns can be chosen to be issued." , |
1218 | int, (rtx_insn *insn, int ready_index), NULL) |
1219 | |
1220 | /* This hook prepares the target for a new round of multipass |
1221 | scheduling. |
1222 | DATA is a pointer to target-specific data used for multipass scheduling. |
1223 | READY_TRY and N_READY represent the current state of search in the |
1224 | optimization space. The target can filter out instructions that |
1225 | should not be tried during current round by setting corresponding |
1226 | elements in READY_TRY to non-zero. |
1227 | FIRST_CYCLE_INSN_P is true if this is the first round of multipass |
1228 | scheduling on current cycle. */ |
1229 | DEFHOOK |
1230 | (first_cycle_multipass_begin, |
1231 | "This hook prepares the target backend for a new round of multipass\n\ |
1232 | scheduling." , |
1233 | void, (void *data, signed char *ready_try, int n_ready, bool first_cycle_insn_p), |
1234 | NULL) |
1235 | |
1236 | /* This hook is called when multipass scheduling evaluates instruction INSN. |
1237 | DATA is a pointer to target-specific data that can be used to record effects |
1238 | of INSN on CPU that are not described in DFA. |
1239 | READY_TRY and N_READY represent the current state of search in the |
1240 | optimization space. The target can filter out instructions that |
1241 | should not be tried after issuing INSN by setting corresponding |
1242 | elements in READY_TRY to non-zero. |
1243 | INSN is the instruction being evaluated. |
1244 | PREV_DATA is a pointer to target-specific data corresponding |
1245 | to a state before issuing INSN. */ |
1246 | DEFHOOK |
1247 | (first_cycle_multipass_issue, |
1248 | "This hook is called when multipass scheduling evaluates instruction INSN." , |
1249 | void, (void *data, signed char *ready_try, int n_ready, rtx_insn *insn, |
1250 | const void *prev_data), NULL) |
1251 | |
1252 | /* This hook is called when multipass scheduling backtracks from evaluation of |
1253 | instruction corresponding to DATA. |
1254 | DATA is a pointer to target-specific data that stores the effects |
1255 | of instruction from which the algorithm backtracks on CPU that are not |
1256 | described in DFA. |
1257 | READY_TRY and N_READY represent the current state of search in the |
1258 | optimization space. The target can filter out instructions that |
1259 | should not be tried after issuing INSN by setting corresponding |
1260 | elements in READY_TRY to non-zero. */ |
1261 | DEFHOOK |
1262 | (first_cycle_multipass_backtrack, |
1263 | "This is called when multipass scheduling backtracks from evaluation of\n\ |
1264 | an instruction." , |
1265 | void, (const void *data, signed char *ready_try, int n_ready), NULL) |
1266 | |
1267 | /* This hook notifies the target about the result of the concluded current |
1268 | round of multipass scheduling. |
1269 | DATA is a pointer. |
1270 | If DATA is non-NULL it points to target-specific data used for multipass |
1271 | scheduling which corresponds to instruction at the start of the chain of |
1272 | the winning solution. DATA is NULL when multipass scheduling cannot find |
1273 | a good enough solution on current cycle and decides to retry later, |
1274 | usually after advancing the cycle count. */ |
1275 | DEFHOOK |
1276 | (first_cycle_multipass_end, |
1277 | "This hook notifies the target about the result of the concluded current\n\ |
1278 | round of multipass scheduling." , |
1279 | void, (const void *data), NULL) |
1280 | |
1281 | /* This hook is called to initialize target-specific data for multipass |
1282 | scheduling after it has been allocated. |
1283 | DATA is a pointer to target-specific data that stores the effects |
1284 | of instruction from which the algorithm backtracks on CPU that are not |
1285 | described in DFA. */ |
1286 | DEFHOOK |
1287 | (first_cycle_multipass_init, |
1288 | "This hook initializes target-specific data used in multipass scheduling." , |
1289 | void, (void *data), NULL) |
1290 | |
1291 | /* This hook is called to finalize target-specific data for multipass |
1292 | scheduling before it is deallocated. |
1293 | DATA is a pointer to target-specific data that stores the effects |
1294 | of instruction from which the algorithm backtracks on CPU that are not |
1295 | described in DFA. */ |
1296 | DEFHOOK |
1297 | (first_cycle_multipass_fini, |
1298 | "This hook finalizes target-specific data used in multipass scheduling." , |
1299 | void, (void *data), NULL) |
1300 | |
1301 | /* The following member value is pointer to a function called by |
1302 | the insn scheduler before issuing insn passed as the third |
1303 | parameter on given cycle. If the hook returns nonzero, the |
1304 | insn is not issued on given processors cycle. Instead of that, |
1305 | the processor cycle is advanced. If the value passed through |
1306 | the last parameter is zero, the insn ready queue is not sorted |
1307 | on the new cycle start as usually. The first parameter passes |
1308 | file for debugging output. The second one passes the scheduler |
1309 | verbose level of the debugging output. The forth and the fifth |
1310 | parameter values are correspondingly processor cycle on which |
1311 | the previous insn has been issued and the current processor cycle. */ |
1312 | DEFHOOK |
1313 | (dfa_new_cycle, |
1314 | "This hook is called by the insn scheduler before issuing @var{insn}\n\ |
1315 | on cycle @var{clock}. If the hook returns nonzero,\n\ |
1316 | @var{insn} is not issued on this processor cycle. Instead,\n\ |
1317 | the processor cycle is advanced. If *@var{sort_p}\n\ |
1318 | is zero, the insn ready queue is not sorted on the new cycle\n\ |
1319 | start as usually. @var{dump} and @var{verbose} specify the file and\n\ |
1320 | verbosity level to use for debugging output.\n\ |
1321 | @var{last_clock} and @var{clock} are, respectively, the\n\ |
1322 | processor cycle on which the previous insn has been issued,\n\ |
1323 | and the current processor cycle." , |
1324 | int, (FILE *dump, int verbose, rtx_insn *insn, int last_clock, |
1325 | int clock, int *sort_p), |
1326 | NULL) |
1327 | |
1328 | /* The following member value is a pointer to a function called by the |
1329 | insn scheduler. It should return true if there exists a dependence |
1330 | which is considered costly by the target, between the insn |
1331 | DEP_PRO (&_DEP), and the insn DEP_CON (&_DEP). The first parameter is |
1332 | the dep that represents the dependence between the two insns. The |
1333 | second argument is the cost of the dependence as estimated by |
1334 | the scheduler. The last argument is the distance in cycles |
1335 | between the already scheduled insn (first parameter) and the |
1336 | second insn (second parameter). */ |
1337 | DEFHOOK |
1338 | (is_costly_dependence, |
1339 | "This hook is used to define which dependences are considered costly by\n\ |
1340 | the target, so costly that it is not advisable to schedule the insns that\n\ |
1341 | are involved in the dependence too close to one another. The parameters\n\ |
1342 | to this hook are as follows: The first parameter @var{_dep} is the dependence\n\ |
1343 | being evaluated. The second parameter @var{cost} is the cost of the\n\ |
1344 | dependence as estimated by the scheduler, and the third\n\ |
1345 | parameter @var{distance} is the distance in cycles between the two insns.\n\ |
1346 | The hook returns @code{true} if considering the distance between the two\n\ |
1347 | insns the dependence between them is considered costly by the target,\n\ |
1348 | and @code{false} otherwise.\n\ |
1349 | \n\ |
1350 | Defining this hook can be useful in multiple-issue out-of-order machines,\n\ |
1351 | where (a) it's practically hopeless to predict the actual data/resource\n\ |
1352 | delays, however: (b) there's a better chance to predict the actual grouping\n\ |
1353 | that will be formed, and (c) correctly emulating the grouping can be very\n\ |
1354 | important. In such targets one may want to allow issuing dependent insns\n\ |
1355 | closer to one another---i.e., closer than the dependence distance; however,\n\ |
1356 | not in cases of ``costly dependences'', which this hooks allows to define." , |
1357 | bool, (struct _dep *_dep, int cost, int distance), NULL) |
1358 | |
1359 | /* The following member value is a pointer to a function called |
1360 | by the insn scheduler. This hook is called to notify the backend |
1361 | that new instructions were emitted. */ |
1362 | DEFHOOK |
1363 | (h_i_d_extended, |
1364 | "This hook is called by the insn scheduler after emitting a new instruction to\n\ |
1365 | the instruction stream. The hook notifies a target backend to extend its\n\ |
1366 | per instruction data structures." , |
1367 | void, (void), NULL) |
1368 | |
1369 | /* Next 5 functions are for multi-point scheduling. */ |
1370 | |
1371 | /* Allocate memory for scheduler context. */ |
1372 | DEFHOOK |
1373 | (alloc_sched_context, |
1374 | "Return a pointer to a store large enough to hold target scheduling context." , |
1375 | void *, (void), NULL) |
1376 | |
1377 | /* Fills the context from the local machine scheduler context. */ |
1378 | DEFHOOK |
1379 | (init_sched_context, |
1380 | "Initialize store pointed to by @var{tc} to hold target scheduling context.\n\ |
1381 | It @var{clean_p} is true then initialize @var{tc} as if scheduler is at the\n\ |
1382 | beginning of the block. Otherwise, copy the current context into @var{tc}." , |
1383 | void, (void *tc, bool clean_p), NULL) |
1384 | |
1385 | /* Sets local machine scheduler context to a saved value. */ |
1386 | DEFHOOK |
1387 | (set_sched_context, |
1388 | "Copy target scheduling context pointed to by @var{tc} to the current context." , |
1389 | void, (void *tc), NULL) |
1390 | |
1391 | /* Clears a scheduler context so it becomes like after init. */ |
1392 | DEFHOOK |
1393 | (clear_sched_context, |
1394 | "Deallocate internal data in target scheduling context pointed to by @var{tc}." , |
1395 | void, (void *tc), NULL) |
1396 | |
1397 | /* Frees the scheduler context. */ |
1398 | DEFHOOK |
1399 | (free_sched_context, |
1400 | "Deallocate a store for target scheduling context pointed to by @var{tc}." , |
1401 | void, (void *tc), NULL) |
1402 | |
1403 | /* The following member value is a pointer to a function called |
1404 | by the insn scheduler. |
1405 | The first parameter is an instruction, the second parameter is the type |
1406 | of the requested speculation, and the third parameter is a pointer to the |
1407 | speculative pattern of the corresponding type (set if return value == 1). |
1408 | It should return |
1409 | -1, if there is no pattern, that will satisfy the requested speculation type, |
1410 | 0, if current pattern satisfies the requested speculation type, |
1411 | 1, if pattern of the instruction should be changed to the newly |
1412 | generated one. */ |
1413 | DEFHOOK |
1414 | (speculate_insn, |
1415 | "This hook is called by the insn scheduler when @var{insn} has only\n\ |
1416 | speculative dependencies and therefore can be scheduled speculatively.\n\ |
1417 | The hook is used to check if the pattern of @var{insn} has a speculative\n\ |
1418 | version and, in case of successful check, to generate that speculative\n\ |
1419 | pattern. The hook should return 1, if the instruction has a speculative form,\n\ |
1420 | or @minus{}1, if it doesn't. @var{request} describes the type of requested\n\ |
1421 | speculation. If the return value equals 1 then @var{new_pat} is assigned\n\ |
1422 | the generated speculative pattern." , |
1423 | int, (rtx_insn *insn, unsigned int dep_status, rtx *new_pat), NULL) |
1424 | |
1425 | /* The following member value is a pointer to a function called |
1426 | by the insn scheduler. It should return true if the check instruction |
1427 | passed as the parameter needs a recovery block. */ |
1428 | DEFHOOK |
1429 | (needs_block_p, |
1430 | "This hook is called by the insn scheduler during generation of recovery code\n\ |
1431 | for @var{insn}. It should return @code{true}, if the corresponding check\n\ |
1432 | instruction should branch to recovery code, or @code{false} otherwise." , |
1433 | bool, (unsigned int dep_status), NULL) |
1434 | |
1435 | /* The following member value is a pointer to a function called |
1436 | by the insn scheduler. It should return a pattern for the check |
1437 | instruction. |
1438 | The first parameter is a speculative instruction, the second parameter |
1439 | is the label of the corresponding recovery block (or null, if it is a |
1440 | simple check). The third parameter is the kind of speculation that |
1441 | is being performed. */ |
1442 | DEFHOOK |
1443 | (gen_spec_check, |
1444 | "This hook is called by the insn scheduler to generate a pattern for recovery\n\ |
1445 | check instruction. If @var{mutate_p} is zero, then @var{insn} is a\n\ |
1446 | speculative instruction for which the check should be generated.\n\ |
1447 | @var{label} is either a label of a basic block, where recovery code should\n\ |
1448 | be emitted, or a null pointer, when requested check doesn't branch to\n\ |
1449 | recovery code (a simple check). If @var{mutate_p} is nonzero, then\n\ |
1450 | a pattern for a branchy check corresponding to a simple check denoted by\n\ |
1451 | @var{insn} should be generated. In this case @var{label} can't be null." , |
1452 | rtx, (rtx_insn *insn, rtx_insn *label, unsigned int ds), NULL) |
1453 | |
1454 | /* The following member value is a pointer to a function that provides |
1455 | information about the speculation capabilities of the target. |
1456 | The parameter is a pointer to spec_info variable. */ |
1457 | DEFHOOK |
1458 | (set_sched_flags, |
1459 | "This hook is used by the insn scheduler to find out what features should be\n\ |
1460 | enabled/used.\n\ |
1461 | The structure *@var{spec_info} should be filled in by the target.\n\ |
1462 | The structure describes speculation types that can be used in the scheduler." , |
1463 | void, (struct spec_info_def *spec_info), NULL) |
1464 | |
1465 | DEFHOOK_UNDOC |
1466 | (get_insn_spec_ds, |
1467 | "Return speculation types of instruction @var{insn}." , |
1468 | unsigned int, (rtx_insn *insn), NULL) |
1469 | |
1470 | DEFHOOK_UNDOC |
1471 | (get_insn_checked_ds, |
1472 | "Return speculation types that are checked for instruction @var{insn}" , |
1473 | unsigned int, (rtx_insn *insn), NULL) |
1474 | |
1475 | DEFHOOK |
1476 | (can_speculate_insn, |
1477 | "Some instructions should never be speculated by the schedulers, usually\n\ |
1478 | because the instruction is too expensive to get this wrong. Often such\n\ |
1479 | instructions have long latency, and often they are not fully modeled in the\n\ |
1480 | pipeline descriptions. This hook should return @code{false} if @var{insn}\n\ |
1481 | should not be speculated." , |
1482 | bool, (rtx_insn *insn), hook_bool_rtx_insn_true) |
1483 | |
1484 | DEFHOOK_UNDOC |
1485 | (skip_rtx_p, |
1486 | "Return bool if rtx scanning should just skip current layer and\ |
1487 | advance to the inner rtxes." , |
1488 | bool, (const_rtx x), NULL) |
1489 | |
1490 | /* The following member value is a pointer to a function that provides |
1491 | information about the target resource-based lower bound which is |
1492 | used by the swing modulo scheduler. The parameter is a pointer |
1493 | to ddg variable. */ |
1494 | DEFHOOK |
1495 | (sms_res_mii, |
1496 | "This hook is called by the swing modulo scheduler to calculate a\n\ |
1497 | resource-based lower bound which is based on the resources available in\n\ |
1498 | the machine and the resources required by each instruction. The target\n\ |
1499 | backend can use @var{g} to calculate such bound. A very simple lower\n\ |
1500 | bound will be used in case this hook is not implemented: the total number\n\ |
1501 | of instructions divided by the issue rate." , |
1502 | int, (struct ddg *g), NULL) |
1503 | |
1504 | /* The following member value is a function that initializes dispatch |
1505 | schedling and adds instructions to dispatch window according to its |
1506 | parameters. */ |
1507 | DEFHOOK |
1508 | (dispatch_do, |
1509 | "This hook is called by Haifa Scheduler. It performs the operation specified\n\ |
1510 | in its second parameter." , |
1511 | void, (rtx_insn *insn, int x), |
1512 | hook_void_rtx_insn_int) |
1513 | |
1514 | /* The following member value is a function that returns true is |
1515 | dispatch schedling is supported in hardware and condition passed |
1516 | as the second parameter is true. */ |
1517 | DEFHOOK |
1518 | (dispatch, |
1519 | "This hook is called by Haifa Scheduler. It returns true if dispatch scheduling\n\ |
1520 | is supported in hardware and the condition specified in the parameter is true." , |
1521 | bool, (rtx_insn *insn, int x), |
1522 | hook_bool_rtx_insn_int_false) |
1523 | |
1524 | DEFHOOKPOD |
1525 | (exposed_pipeline, |
1526 | "True if the processor has an exposed pipeline, which means that not just\n\ |
1527 | the order of instructions is important for correctness when scheduling, but\n\ |
1528 | also the latencies of operations." , |
1529 | bool, false) |
1530 | |
1531 | /* The following member value is a function that returns number |
1532 | of operations reassociator should try to put in parallel for |
1533 | statements of the given type. By default 1 is used. */ |
1534 | DEFHOOK |
1535 | (reassociation_width, |
1536 | "This hook is called by tree reassociator to determine a level of\n\ |
1537 | parallelism required in output calculations chain." , |
1538 | int, (unsigned int opc, machine_mode mode), |
1539 | hook_int_uint_mode_1) |
1540 | |
1541 | /* The following member value is a function that returns priority for |
1542 | fusion of each instruction via pointer parameters. */ |
1543 | DEFHOOK |
1544 | (fusion_priority, |
1545 | "This hook is called by scheduling fusion pass. It calculates fusion\n\ |
1546 | priorities for each instruction passed in by parameter. The priorities\n\ |
1547 | are returned via pointer parameters.\n\ |
1548 | \n\ |
1549 | @var{insn} is the instruction whose priorities need to be calculated.\n\ |
1550 | @var{max_pri} is the maximum priority can be returned in any cases.\n\ |
1551 | @var{fusion_pri} is the pointer parameter through which @var{insn}'s\n\ |
1552 | fusion priority should be calculated and returned.\n\ |
1553 | @var{pri} is the pointer parameter through which @var{insn}'s priority\n\ |
1554 | should be calculated and returned.\n\ |
1555 | \n\ |
1556 | Same @var{fusion_pri} should be returned for instructions which should\n\ |
1557 | be scheduled together. Different @var{pri} should be returned for\n\ |
1558 | instructions with same @var{fusion_pri}. @var{fusion_pri} is the major\n\ |
1559 | sort key, @var{pri} is the minor sort key. All instructions will be\n\ |
1560 | scheduled according to the two priorities. All priorities calculated\n\ |
1561 | should be between 0 (exclusive) and @var{max_pri} (inclusive). To avoid\n\ |
1562 | false dependencies, @var{fusion_pri} of instructions which need to be\n\ |
1563 | scheduled together should be smaller than @var{fusion_pri} of irrelevant\n\ |
1564 | instructions.\n\ |
1565 | \n\ |
1566 | Given below example:\n\ |
1567 | \n\ |
1568 | @smallexample\n\ |
1569 | ldr r10, [r1, 4]\n\ |
1570 | add r4, r4, r10\n\ |
1571 | ldr r15, [r2, 8]\n\ |
1572 | sub r5, r5, r15\n\ |
1573 | ldr r11, [r1, 0]\n\ |
1574 | add r4, r4, r11\n\ |
1575 | ldr r16, [r2, 12]\n\ |
1576 | sub r5, r5, r16\n\ |
1577 | @end smallexample\n\ |
1578 | \n\ |
1579 | On targets like ARM/AArch64, the two pairs of consecutive loads should be\n\ |
1580 | merged. Since peephole2 pass can't help in this case unless consecutive\n\ |
1581 | loads are actually next to each other in instruction flow. That's where\n\ |
1582 | this scheduling fusion pass works. This hook calculates priority for each\n\ |
1583 | instruction based on its fustion type, like:\n\ |
1584 | \n\ |
1585 | @smallexample\n\ |
1586 | ldr r10, [r1, 4] ; fusion_pri=99, pri=96\n\ |
1587 | add r4, r4, r10 ; fusion_pri=100, pri=100\n\ |
1588 | ldr r15, [r2, 8] ; fusion_pri=98, pri=92\n\ |
1589 | sub r5, r5, r15 ; fusion_pri=100, pri=100\n\ |
1590 | ldr r11, [r1, 0] ; fusion_pri=99, pri=100\n\ |
1591 | add r4, r4, r11 ; fusion_pri=100, pri=100\n\ |
1592 | ldr r16, [r2, 12] ; fusion_pri=98, pri=88\n\ |
1593 | sub r5, r5, r16 ; fusion_pri=100, pri=100\n\ |
1594 | @end smallexample\n\ |
1595 | \n\ |
1596 | Scheduling fusion pass then sorts all ready to issue instructions according\n\ |
1597 | to the priorities. As a result, instructions of same fusion type will be\n\ |
1598 | pushed together in instruction flow, like:\n\ |
1599 | \n\ |
1600 | @smallexample\n\ |
1601 | ldr r11, [r1, 0]\n\ |
1602 | ldr r10, [r1, 4]\n\ |
1603 | ldr r15, [r2, 8]\n\ |
1604 | ldr r16, [r2, 12]\n\ |
1605 | add r4, r4, r10\n\ |
1606 | sub r5, r5, r15\n\ |
1607 | add r4, r4, r11\n\ |
1608 | sub r5, r5, r16\n\ |
1609 | @end smallexample\n\ |
1610 | \n\ |
1611 | Now peephole2 pass can simply merge the two pairs of loads.\n\ |
1612 | \n\ |
1613 | Since scheduling fusion pass relies on peephole2 to do real fusion\n\ |
1614 | work, it is only enabled by default when peephole2 is in effect.\n\ |
1615 | \n\ |
1616 | This is firstly introduced on ARM/AArch64 targets, please refer to\n\ |
1617 | the hook implementation for how different fusion types are supported." , |
1618 | void, (rtx_insn *insn, int max_pri, int *fusion_pri, int *pri), NULL) |
1619 | |
1620 | HOOK_VECTOR_END (sched) |
1621 | |
1622 | /* Functions relating to OpenMP SIMD and __attribute__((simd)) clones. */ |
1623 | #undef HOOK_PREFIX |
1624 | #define HOOK_PREFIX "TARGET_SIMD_CLONE_" |
1625 | HOOK_VECTOR (TARGET_SIMD_CLONE, simd_clone) |
1626 | |
1627 | DEFHOOK |
1628 | (compute_vecsize_and_simdlen, |
1629 | "This hook should set @var{vecsize_mangle}, @var{vecsize_int}, @var{vecsize_float}\n\ |
1630 | fields in @var{simd_clone} structure pointed by @var{clone_info} argument and also\n\ |
1631 | @var{simdlen} field if it was previously 0.\n\ |
1632 | @var{vecsize_mangle} is a marker for the backend only. @var{vecsize_int} and\n\ |
1633 | @var{vecsize_float} should be left zero on targets where the number of lanes is\n\ |
1634 | not determined by the bitsize (in which case @var{simdlen} is always used).\n\ |
1635 | The hook should return 0 if SIMD clones shouldn't be emitted,\n\ |
1636 | or number of @var{vecsize_mangle} variants that should be emitted." , |
1637 | int, (struct cgraph_node *, struct cgraph_simd_clone *, tree, int, bool), NULL) |
1638 | |
1639 | DEFHOOK |
1640 | (adjust, |
1641 | "This hook should add implicit @code{attribute(target(\"...\"))} attribute\n\ |
1642 | to SIMD clone @var{node} if needed." , |
1643 | void, (struct cgraph_node *), NULL) |
1644 | |
1645 | DEFHOOK |
1646 | (usable, |
1647 | "This hook should return -1 if SIMD clone @var{node} shouldn't be used\n\ |
1648 | in vectorized loops in current function, or non-negative number if it is\n\ |
1649 | usable. In that case, the smaller the number is, the more desirable it is\n\ |
1650 | to use it." , |
1651 | int, (struct cgraph_node *), NULL) |
1652 | |
1653 | HOOK_VECTOR_END (simd_clone) |
1654 | |
1655 | /* Functions relating to OpenMP SIMT vectorization transform. */ |
1656 | #undef HOOK_PREFIX |
1657 | #define HOOK_PREFIX "TARGET_SIMT_" |
1658 | HOOK_VECTOR (TARGET_SIMT, simt) |
1659 | |
1660 | DEFHOOK |
1661 | (vf, |
1662 | "Return number of threads in SIMT thread group on the target." , |
1663 | int, (void), NULL) |
1664 | |
1665 | HOOK_VECTOR_END (simt) |
1666 | |
1667 | /* Functions relating to OpenMP. */ |
1668 | #undef HOOK_PREFIX |
1669 | #define HOOK_PREFIX "TARGET_OMP_" |
1670 | HOOK_VECTOR (TARGET_OMP, omp) |
1671 | |
1672 | DEFHOOK |
1673 | (device_kind_arch_isa, |
1674 | "Return 1 if @var{trait} @var{name} is present in the OpenMP context's\n\ |
1675 | device trait set, return 0 if not present in any OpenMP context in the\n\ |
1676 | whole translation unit, or -1 if not present in the current OpenMP context\n\ |
1677 | but might be present in another OpenMP context in the same TU." , |
1678 | int, (enum omp_device_kind_arch_isa trait, const char *name), NULL) |
1679 | |
1680 | HOOK_VECTOR_END (omp) |
1681 | |
1682 | /* Functions relating to openacc. */ |
1683 | #undef HOOK_PREFIX |
1684 | #define HOOK_PREFIX "TARGET_GOACC_" |
1685 | HOOK_VECTOR (TARGET_GOACC, goacc) |
1686 | |
1687 | DEFHOOK |
1688 | (validate_dims, |
1689 | "This hook should check the launch dimensions provided for an OpenACC\n\ |
1690 | compute region, or routine. Defaulted values are represented as -1\n\ |
1691 | and non-constant values as 0. The @var{fn_level} is negative for the\n\ |
1692 | function corresponding to the compute region. For a routine it is the\n\ |
1693 | outermost level at which partitioned execution may be spawned. The hook\n\ |
1694 | should verify non-default values. If DECL is NULL, global defaults\n\ |
1695 | are being validated and unspecified defaults should be filled in.\n\ |
1696 | Diagnostics should be issued as appropriate. Return\n\ |
1697 | true, if changes have been made. You must override this hook to\n\ |
1698 | provide dimensions larger than 1." , |
1699 | bool, (tree decl, int *dims, int fn_level, unsigned used), |
1700 | default_goacc_validate_dims) |
1701 | |
1702 | DEFHOOK |
1703 | (dim_limit, |
1704 | "This hook should return the maximum size of a particular dimension,\n\ |
1705 | or zero if unbounded." , |
1706 | int, (int axis), |
1707 | default_goacc_dim_limit) |
1708 | |
1709 | DEFHOOK |
1710 | (fork_join, |
1711 | "This hook can be used to convert IFN_GOACC_FORK and IFN_GOACC_JOIN\n\ |
1712 | function calls to target-specific gimple, or indicate whether they\n\ |
1713 | should be retained. It is executed during the oacc_device_lower pass.\n\ |
1714 | It should return true, if the call should be retained. It should\n\ |
1715 | return false, if it is to be deleted (either because target-specific\n\ |
1716 | gimple has been inserted before it, or there is no need for it).\n\ |
1717 | The default hook returns false, if there are no RTL expanders for them." , |
1718 | bool, (gcall *call, const int *dims, bool is_fork), |
1719 | default_goacc_fork_join) |
1720 | |
1721 | DEFHOOK |
1722 | (reduction, |
1723 | "This hook is used by the oacc_transform pass to expand calls to the\n\ |
1724 | @var{GOACC_REDUCTION} internal function, into a sequence of gimple\n\ |
1725 | instructions. @var{call} is gimple statement containing the call to\n\ |
1726 | the function. This hook removes statement @var{call} after the\n\ |
1727 | expanded sequence has been inserted. This hook is also responsible\n\ |
1728 | for allocating any storage for reductions when necessary." , |
1729 | void, (gcall *call), |
1730 | default_goacc_reduction) |
1731 | |
1732 | DEFHOOK |
1733 | (adjust_private_decl, |
1734 | "This hook, if defined, is used by accelerator target back-ends to adjust\n\ |
1735 | OpenACC variable declarations that should be made private to the given\n\ |
1736 | parallelism level (i.e. @code{GOMP_DIM_GANG}, @code{GOMP_DIM_WORKER} or\n\ |
1737 | @code{GOMP_DIM_VECTOR}). A typical use for this hook is to force variable\n\ |
1738 | declarations at the @code{gang} level to reside in GPU shared memory.\n\ |
1739 | @var{loc} may be used for diagnostic purposes.\n\ |
1740 | \n\ |
1741 | You may also use the @code{TARGET_GOACC_EXPAND_VAR_DECL} hook if the\n\ |
1742 | adjusted variable declaration needs to be expanded to RTL in a non-standard\n\ |
1743 | way." , |
1744 | tree, (location_t loc, tree var, int level), |
1745 | NULL) |
1746 | |
1747 | DEFHOOK |
1748 | (expand_var_decl, |
1749 | "This hook, if defined, is used by accelerator target back-ends to expand\n\ |
1750 | specially handled kinds of @code{VAR_DECL} expressions. A particular use is\n\ |
1751 | to place variables with specific attributes inside special accelarator\n\ |
1752 | memories. A return value of @code{NULL} indicates that the target does not\n\ |
1753 | handle this @code{VAR_DECL}, and normal RTL expanding is resumed.\n\ |
1754 | \n\ |
1755 | Only define this hook if your accelerator target needs to expand certain\n\ |
1756 | @code{VAR_DECL} nodes in a way that differs from the default. You can also adjust\n\ |
1757 | private variables at OpenACC device-lowering time using the\n\ |
1758 | @code{TARGET_GOACC_ADJUST_PRIVATE_DECL} target hook." , |
1759 | rtx, (tree var), |
1760 | NULL) |
1761 | |
1762 | DEFHOOK |
1763 | (create_worker_broadcast_record, |
1764 | "Create a record used to propagate local-variable state from an active\n\ |
1765 | worker to other workers. A possible implementation might adjust the type\n\ |
1766 | of REC to place the new variable in shared GPU memory.\n\ |
1767 | \n\ |
1768 | Presence of this target hook indicates that middle end neutering/broadcasting\n\ |
1769 | be used." , |
1770 | tree, (tree rec, bool sender, const char *name, unsigned HOST_WIDE_INT offset), |
1771 | NULL) |
1772 | |
1773 | DEFHOOK |
1774 | (shared_mem_layout, |
1775 | "Lay out a fixed shared-memory region on the target. The LO and HI\n\ |
1776 | arguments should be set to a range of addresses that can be used for worker\n\ |
1777 | broadcasting. The dimensions, reduction size and gang-private size\n\ |
1778 | arguments are for the current offload region." , |
1779 | void, (unsigned HOST_WIDE_INT *, unsigned HOST_WIDE_INT *, int[], |
1780 | unsigned HOST_WIDE_INT[], unsigned HOST_WIDE_INT[]), |
1781 | NULL) |
1782 | |
1783 | HOOK_VECTOR_END (goacc) |
1784 | |
1785 | /* Functions relating to vectorization. */ |
1786 | #undef HOOK_PREFIX |
1787 | #define HOOK_PREFIX "TARGET_VECTORIZE_" |
1788 | HOOK_VECTOR (TARGET_VECTORIZE, vectorize) |
1789 | |
1790 | /* The following member value is a pointer to a function called |
1791 | by the vectorizer, and return the decl of the target builtin |
1792 | function. */ |
1793 | DEFHOOK |
1794 | (builtin_mask_for_load, |
1795 | "This hook should return the DECL of a function @var{f} that given an\n\ |
1796 | address @var{addr} as an argument returns a mask @var{m} that can be\n\ |
1797 | used to extract from two vectors the relevant data that resides in\n\ |
1798 | @var{addr} in case @var{addr} is not properly aligned.\n\ |
1799 | \n\ |
1800 | The autovectorizer, when vectorizing a load operation from an address\n\ |
1801 | @var{addr} that may be unaligned, will generate two vector loads from\n\ |
1802 | the two aligned addresses around @var{addr}. It then generates a\n\ |
1803 | @code{REALIGN_LOAD} operation to extract the relevant data from the\n\ |
1804 | two loaded vectors. The first two arguments to @code{REALIGN_LOAD},\n\ |
1805 | @var{v1} and @var{v2}, are the two vectors, each of size @var{VS}, and\n\ |
1806 | the third argument, @var{OFF}, defines how the data will be extracted\n\ |
1807 | from these two vectors: if @var{OFF} is 0, then the returned vector is\n\ |
1808 | @var{v2}; otherwise, the returned vector is composed from the last\n\ |
1809 | @var{VS}-@var{OFF} elements of @var{v1} concatenated to the first\n\ |
1810 | @var{OFF} elements of @var{v2}.\n\ |
1811 | \n\ |
1812 | If this hook is defined, the autovectorizer will generate a call\n\ |
1813 | to @var{f} (using the DECL tree that this hook returns) and will\n\ |
1814 | use the return value of @var{f} as the argument @var{OFF} to\n\ |
1815 | @code{REALIGN_LOAD}. Therefore, the mask @var{m} returned by @var{f}\n\ |
1816 | should comply with the semantics expected by @code{REALIGN_LOAD}\n\ |
1817 | described above.\n\ |
1818 | If this hook is not defined, then @var{addr} will be used as\n\ |
1819 | the argument @var{OFF} to @code{REALIGN_LOAD}, in which case the low\n\ |
1820 | log2(@var{VS}) @minus{} 1 bits of @var{addr} will be considered." , |
1821 | tree, (void), NULL) |
1822 | |
1823 | /* Returns a built-in function that realizes the vectorized version of |
1824 | a target-independent function, or NULL_TREE if not available. */ |
1825 | DEFHOOK |
1826 | (builtin_vectorized_function, |
1827 | "This hook should return the decl of a function that implements the\n\ |
1828 | vectorized variant of the function with the @code{combined_fn} code\n\ |
1829 | @var{code} or @code{NULL_TREE} if such a function is not available.\n\ |
1830 | The return type of the vectorized function shall be of vector type\n\ |
1831 | @var{vec_type_out} and the argument types should be @var{vec_type_in}." , |
1832 | tree, (unsigned code, tree vec_type_out, tree vec_type_in), |
1833 | default_builtin_vectorized_function) |
1834 | |
1835 | /* Returns a built-in function that realizes the vectorized version of |
1836 | a target-specific function, or NULL_TREE if not available. */ |
1837 | DEFHOOK |
1838 | (builtin_md_vectorized_function, |
1839 | "This hook should return the decl of a function that implements the\n\ |
1840 | vectorized variant of target built-in function @code{fndecl}. The\n\ |
1841 | return type of the vectorized function shall be of vector type\n\ |
1842 | @var{vec_type_out} and the argument types should be @var{vec_type_in}." , |
1843 | tree, (tree fndecl, tree vec_type_out, tree vec_type_in), |
1844 | default_builtin_md_vectorized_function) |
1845 | |
1846 | /* Cost of different vector/scalar statements in vectorization cost |
1847 | model. In case of misaligned vector loads and stores the cost depends |
1848 | on the data type and misalignment value. */ |
1849 | DEFHOOK |
1850 | (builtin_vectorization_cost, |
1851 | "Returns cost of different scalar or vector statements for vectorization cost model.\n\ |
1852 | For vector memory operations the cost may depend on type (@var{vectype}) and\n\ |
1853 | misalignment value (@var{misalign})." , |
1854 | int, (enum vect_cost_for_stmt type_of_cost, tree vectype, int misalign), |
1855 | default_builtin_vectorization_cost) |
1856 | |
1857 | DEFHOOK |
1858 | (preferred_vector_alignment, |
1859 | "This hook returns the preferred alignment in bits for accesses to\n\ |
1860 | vectors of type @var{type} in vectorized code. This might be less than\n\ |
1861 | or greater than the ABI-defined value returned by\n\ |
1862 | @code{TARGET_VECTOR_ALIGNMENT}. It can be equal to the alignment of\n\ |
1863 | a single element, in which case the vectorizer will not try to optimize\n\ |
1864 | for alignment.\n\ |
1865 | \n\ |
1866 | The default hook returns @code{TYPE_ALIGN (@var{type})}, which is\n\ |
1867 | correct for most targets." , |
1868 | poly_uint64, (const_tree type), |
1869 | default_preferred_vector_alignment) |
1870 | |
1871 | /* Returns whether the target has a preference for decomposing divisions using |
1872 | shifts rather than multiplies. */ |
1873 | DEFHOOK |
1874 | (preferred_div_as_shifts_over_mult, |
1875 | "Sometimes it is possible to implement a vector division using a sequence\n\ |
1876 | of two addition-shift pairs, giving four instructions in total.\n\ |
1877 | Return true if taking this approach for @var{vectype} is likely\n\ |
1878 | to be better than using a sequence involving highpart multiplication.\n\ |
1879 | Default is false if @code{can_mult_highpart_p}, otherwise true." , |
1880 | bool, (const_tree type), |
1881 | default_preferred_div_as_shifts_over_mult) |
1882 | |
1883 | /* Return true if vector alignment is reachable (by peeling N |
1884 | iterations) for the given scalar type. */ |
1885 | DEFHOOK |
1886 | (vector_alignment_reachable, |
1887 | "Return true if vector alignment is reachable (by peeling N iterations)\n\ |
1888 | for the given scalar type @var{type}. @var{is_packed} is false if the scalar\n\ |
1889 | access using @var{type} is known to be naturally aligned." , |
1890 | bool, (const_tree type, bool is_packed), |
1891 | default_builtin_vector_alignment_reachable) |
1892 | |
1893 | DEFHOOK |
1894 | (vec_perm_const, |
1895 | "This hook is used to test whether the target can permute up to two\n\ |
1896 | vectors of mode @var{op_mode} using the permutation vector @code{sel},\n\ |
1897 | producing a vector of mode @var{mode}. The hook is also used to emit such\n\ |
1898 | a permutation.\n\ |
1899 | \n\ |
1900 | When the hook is being used to test whether the target supports a permutation,\n\ |
1901 | @var{in0}, @var{in1}, and @var{out} are all null. When the hook is being used\n\ |
1902 | to emit a permutation, @var{in0} and @var{in1} are the source vectors of mode\n\ |
1903 | @var{op_mode} and @var{out} is the destination vector of mode @var{mode}.\n\ |
1904 | @var{in1} is the same as @var{in0} if @var{sel} describes a permutation on one\n\ |
1905 | vector instead of two.\n\ |
1906 | \n\ |
1907 | Return true if the operation is possible, emitting instructions for it\n\ |
1908 | if rtxes are provided.\n\ |
1909 | \n\ |
1910 | @cindex @code{vec_perm@var{m}} instruction pattern\n\ |
1911 | If the hook returns false for a mode with multibyte elements, GCC will\n\ |
1912 | try the equivalent byte operation. If that also fails, it will try forcing\n\ |
1913 | the selector into a register and using the @var{vec_perm@var{mode}}\n\ |
1914 | instruction pattern. There is no need for the hook to handle these two\n\ |
1915 | implementation approaches itself." , |
1916 | bool, (machine_mode mode, machine_mode op_mode, rtx output, rtx in0, rtx in1, |
1917 | const vec_perm_indices &sel), |
1918 | NULL) |
1919 | |
1920 | /* Return true if the target supports misaligned store/load of a |
1921 | specific factor denoted in the third parameter. The last parameter |
1922 | is true if the access is defined in a packed struct. */ |
1923 | DEFHOOK |
1924 | (support_vector_misalignment, |
1925 | "This hook should return true if the target supports misaligned vector\n\ |
1926 | store/load of a specific factor denoted in the @var{misalignment}\n\ |
1927 | parameter. The vector store/load should be of machine mode @var{mode} and\n\ |
1928 | the elements in the vectors should be of type @var{type}. @var{is_packed}\n\ |
1929 | parameter is true if the memory access is defined in a packed struct." , |
1930 | bool, |
1931 | (machine_mode mode, const_tree type, int misalignment, bool is_packed), |
1932 | default_builtin_support_vector_misalignment) |
1933 | |
1934 | /* Returns the preferred mode for SIMD operations for the specified |
1935 | scalar mode. */ |
1936 | DEFHOOK |
1937 | (preferred_simd_mode, |
1938 | "This hook should return the preferred mode for vectorizing scalar\n\ |
1939 | mode @var{mode}. The default is\n\ |
1940 | equal to @code{word_mode}, because the vectorizer can do some\n\ |
1941 | transformations even in absence of specialized @acronym{SIMD} hardware." , |
1942 | machine_mode, |
1943 | (scalar_mode mode), |
1944 | default_preferred_simd_mode) |
1945 | |
1946 | /* Returns the preferred mode for splitting SIMD reductions to. */ |
1947 | DEFHOOK |
1948 | (split_reduction, |
1949 | "This hook should return the preferred mode to split the final reduction\n\ |
1950 | step on @var{mode} to. The reduction is then carried out reducing upper\n\ |
1951 | against lower halves of vectors recursively until the specified mode is\n\ |
1952 | reached. The default is @var{mode} which means no splitting." , |
1953 | machine_mode, |
1954 | (machine_mode), |
1955 | default_split_reduction) |
1956 | |
1957 | /* Returns a mask of vector sizes to iterate over when auto-vectorizing |
1958 | after processing the preferred one derived from preferred_simd_mode. */ |
1959 | DEFHOOK |
1960 | (autovectorize_vector_modes, |
1961 | "If using the mode returned by @code{TARGET_VECTORIZE_PREFERRED_SIMD_MODE}\n\ |
1962 | is not the only approach worth considering, this hook should add one mode to\n\ |
1963 | @var{modes} for each useful alternative approach. These modes are then\n\ |
1964 | passed to @code{TARGET_VECTORIZE_RELATED_MODE} to obtain the vector mode\n\ |
1965 | for a given element mode.\n\ |
1966 | \n\ |
1967 | The modes returned in @var{modes} should use the smallest element mode\n\ |
1968 | possible for the vectorization approach that they represent, preferring\n\ |
1969 | integer modes over floating-poing modes in the event of a tie. The first\n\ |
1970 | mode should be the @code{TARGET_VECTORIZE_PREFERRED_SIMD_MODE} for its\n\ |
1971 | element mode.\n\ |
1972 | \n\ |
1973 | If @var{all} is true, add suitable vector modes even when they are generally\n\ |
1974 | not expected to be worthwhile.\n\ |
1975 | \n\ |
1976 | The hook returns a bitmask of flags that control how the modes in\n\ |
1977 | @var{modes} are used. The flags are:\n\ |
1978 | @table @code\n\ |
1979 | @item VECT_COMPARE_COSTS\n\ |
1980 | Tells the loop vectorizer to try all the provided modes and pick the one\n\ |
1981 | with the lowest cost. By default the vectorizer will choose the first\n\ |
1982 | mode that works.\n\ |
1983 | @end table\n\ |
1984 | \n\ |
1985 | The hook does not need to do anything if the vector returned by\n\ |
1986 | @code{TARGET_VECTORIZE_PREFERRED_SIMD_MODE} is the only one relevant\n\ |
1987 | for autovectorization. The default implementation adds no modes and\n\ |
1988 | returns 0." , |
1989 | unsigned int, |
1990 | (vector_modes *modes, bool all), |
1991 | default_autovectorize_vector_modes) |
1992 | |
1993 | DEFHOOK |
1994 | (related_mode, |
1995 | "If a piece of code is using vector mode @var{vector_mode} and also wants\n\ |
1996 | to operate on elements of mode @var{element_mode}, return the vector mode\n\ |
1997 | it should use for those elements. If @var{nunits} is nonzero, ensure that\n\ |
1998 | the mode has exactly @var{nunits} elements, otherwise pick whichever vector\n\ |
1999 | size pairs the most naturally with @var{vector_mode}. Return an empty\n\ |
2000 | @code{opt_machine_mode} if there is no supported vector mode with the\n\ |
2001 | required properties.\n\ |
2002 | \n\ |
2003 | There is no prescribed way of handling the case in which @var{nunits}\n\ |
2004 | is zero. One common choice is to pick a vector mode with the same size\n\ |
2005 | as @var{vector_mode}; this is the natural choice if the target has a\n\ |
2006 | fixed vector size. Another option is to choose a vector mode with the\n\ |
2007 | same number of elements as @var{vector_mode}; this is the natural choice\n\ |
2008 | if the target has a fixed number of elements. Alternatively, the hook\n\ |
2009 | might choose a middle ground, such as trying to keep the number of\n\ |
2010 | elements as similar as possible while applying maximum and minimum\n\ |
2011 | vector sizes.\n\ |
2012 | \n\ |
2013 | The default implementation uses @code{mode_for_vector} to find the\n\ |
2014 | requested mode, returning a mode with the same size as @var{vector_mode}\n\ |
2015 | when @var{nunits} is zero. This is the correct behavior for most targets." , |
2016 | opt_machine_mode, |
2017 | (machine_mode vector_mode, scalar_mode element_mode, poly_uint64 nunits), |
2018 | default_vectorize_related_mode) |
2019 | |
2020 | /* Function to get a target mode for a vector mask. */ |
2021 | DEFHOOK |
2022 | (get_mask_mode, |
2023 | "Return the mode to use for a vector mask that holds one boolean\n\ |
2024 | result for each element of vector mode @var{mode}. The returned mask mode\n\ |
2025 | can be a vector of integers (class @code{MODE_VECTOR_INT}), a vector of\n\ |
2026 | booleans (class @code{MODE_VECTOR_BOOL}) or a scalar integer (class\n\ |
2027 | @code{MODE_INT}). Return an empty @code{opt_machine_mode} if no such\n\ |
2028 | mask mode exists.\n\ |
2029 | \n\ |
2030 | The default implementation returns a @code{MODE_VECTOR_INT} with the\n\ |
2031 | same size and number of elements as @var{mode}, if such a mode exists." , |
2032 | opt_machine_mode, |
2033 | (machine_mode mode), |
2034 | default_get_mask_mode) |
2035 | |
2036 | /* Function to say whether a masked operation is expensive when the |
2037 | mask is all zeros. */ |
2038 | DEFHOOK |
2039 | (empty_mask_is_expensive, |
2040 | "This hook returns true if masked internal function @var{ifn} (really of\n\ |
2041 | type @code{internal_fn}) should be considered expensive when the mask is\n\ |
2042 | all zeros. GCC can then try to branch around the instruction instead." , |
2043 | bool, |
2044 | (unsigned ifn), |
2045 | default_empty_mask_is_expensive) |
2046 | |
2047 | /* Target builtin that implements vector gather operation. */ |
2048 | DEFHOOK |
2049 | (builtin_gather, |
2050 | "Target builtin that implements vector gather operation. @var{mem_vectype}\n\ |
2051 | is the vector type of the load and @var{index_type} is scalar type of\n\ |
2052 | the index, scaled by @var{scale}.\n\ |
2053 | The default is @code{NULL_TREE} which means to not vectorize gather\n\ |
2054 | loads." , |
2055 | tree, |
2056 | (const_tree mem_vectype, const_tree index_type, int scale), |
2057 | NULL) |
2058 | |
2059 | /* Target builtin that implements vector scatter operation. */ |
2060 | DEFHOOK |
2061 | (builtin_scatter, |
2062 | "Target builtin that implements vector scatter operation. @var{vectype}\n\ |
2063 | is the vector type of the store and @var{index_type} is scalar type of\n\ |
2064 | the index, scaled by @var{scale}.\n\ |
2065 | The default is @code{NULL_TREE} which means to not vectorize scatter\n\ |
2066 | stores." , |
2067 | tree, |
2068 | (const_tree vectype, const_tree index_type, int scale), |
2069 | NULL) |
2070 | |
2071 | /* Target function to initialize the cost model for a loop or block. */ |
2072 | DEFHOOK |
2073 | (create_costs, |
2074 | "This hook should initialize target-specific data structures in preparation\n\ |
2075 | for modeling the costs of vectorizing a loop or basic block. The default\n\ |
2076 | allocates three unsigned integers for accumulating costs for the prologue,\n\ |
2077 | body, and epilogue of the loop or basic block. If @var{loop_info} is\n\ |
2078 | non-NULL, it identifies the loop being vectorized; otherwise a single block\n\ |
2079 | is being vectorized. If @var{costing_for_scalar} is true, it indicates the\n\ |
2080 | current cost model is for the scalar version of a loop or block; otherwise\n\ |
2081 | it is for the vector version." , |
2082 | class vector_costs *, |
2083 | (vec_info *vinfo, bool costing_for_scalar), |
2084 | default_vectorize_create_costs) |
2085 | |
2086 | HOOK_VECTOR_END (vectorize) |
2087 | |
2088 | #undef HOOK_PREFIX |
2089 | #define HOOK_PREFIX "TARGET_" |
2090 | |
2091 | DEFHOOK |
2092 | (preferred_else_value, |
2093 | "This hook returns the target's preferred final argument for a call\n\ |
2094 | to conditional internal function @var{ifn} (really of type\n\ |
2095 | @code{internal_fn}). @var{type} specifies the return type of the\n\ |
2096 | function and @var{ops} are the operands to the conditional operation,\n\ |
2097 | of which there are @var{nops}.\n\ |
2098 | \n\ |
2099 | For example, if @var{ifn} is @code{IFN_COND_ADD}, the hook returns\n\ |
2100 | a value of type @var{type} that should be used when @samp{@var{ops}[0]}\n\ |
2101 | and @samp{@var{ops}[1]} are conditionally added together.\n\ |
2102 | \n\ |
2103 | This hook is only relevant if the target supports conditional patterns\n\ |
2104 | like @code{cond_add@var{m}}. The default implementation returns a zero\n\ |
2105 | constant of type @var{type}." , |
2106 | tree, |
2107 | (unsigned ifn, tree type, unsigned nops, tree *ops), |
2108 | default_preferred_else_value) |
2109 | |
2110 | DEFHOOK |
2111 | (record_offload_symbol, |
2112 | "Used when offloaded functions are seen in the compilation unit and no named\n\ |
2113 | sections are available. It is called once for each symbol that must be\n\ |
2114 | recorded in the offload function and variable table." , |
2115 | void, (tree), |
2116 | hook_void_tree) |
2117 | |
2118 | DEFHOOKPOD |
2119 | (absolute_biggest_alignment, |
2120 | "If defined, this target hook specifies the absolute biggest alignment\n\ |
2121 | that a type or variable can have on this machine, otherwise,\n\ |
2122 | @code{BIGGEST_ALIGNMENT} is used." , |
2123 | HOST_WIDE_INT, BIGGEST_ALIGNMENT) |
2124 | |
2125 | /* Allow target specific overriding of option settings after options have |
2126 | been changed by an attribute or pragma or when it is reset at the |
2127 | end of the code affected by an attribute or pragma. */ |
2128 | DEFHOOK |
2129 | (override_options_after_change, |
2130 | "This target function is similar to the hook @code{TARGET_OPTION_OVERRIDE}\n\ |
2131 | but is called when the optimize level is changed via an attribute or\n\ |
2132 | pragma or when it is reset at the end of the code affected by the\n\ |
2133 | attribute or pragma. It is not called at the beginning of compilation\n\ |
2134 | when @code{TARGET_OPTION_OVERRIDE} is called so if you want to perform these\n\ |
2135 | actions then, you should have @code{TARGET_OPTION_OVERRIDE} call\n\ |
2136 | @code{TARGET_OVERRIDE_OPTIONS_AFTER_CHANGE}." , |
2137 | void, (void), |
2138 | hook_void_void) |
2139 | |
2140 | DEFHOOK |
2141 | (offload_options, |
2142 | "Used when writing out the list of options into an LTO file. It should\n\ |
2143 | translate any relevant target-specific options (such as the ABI in use)\n\ |
2144 | into one of the @option{-foffload} options that exist as a common interface\n\ |
2145 | to express such options. It should return a string containing these options,\n\ |
2146 | separated by spaces, which the caller will free.\n" , |
2147 | char *, (void), hook_charptr_void_null) |
2148 | |
2149 | DEFHOOK_UNDOC |
2150 | (eh_return_filter_mode, |
2151 | "Return machine mode for filter value." , |
2152 | scalar_int_mode, (void), |
2153 | default_eh_return_filter_mode) |
2154 | |
2155 | /* Return machine mode for libgcc expanded cmp instructions. */ |
2156 | DEFHOOK |
2157 | (libgcc_cmp_return_mode, |
2158 | "This target hook should return the mode to be used for the return value\n\ |
2159 | of compare instructions expanded to libgcc calls. If not defined\n\ |
2160 | @code{word_mode} is returned which is the right choice for a majority of\n\ |
2161 | targets." , |
2162 | scalar_int_mode, (void), |
2163 | default_libgcc_cmp_return_mode) |
2164 | |
2165 | /* Return machine mode for libgcc expanded shift instructions. */ |
2166 | DEFHOOK |
2167 | (libgcc_shift_count_mode, |
2168 | "This target hook should return the mode to be used for the shift count operand\n\ |
2169 | of shift instructions expanded to libgcc calls. If not defined\n\ |
2170 | @code{word_mode} is returned which is the right choice for a majority of\n\ |
2171 | targets." , |
2172 | scalar_int_mode, (void), |
2173 | default_libgcc_shift_count_mode) |
2174 | |
2175 | /* Return machine mode to be used for _Unwind_Word type. */ |
2176 | DEFHOOK |
2177 | (unwind_word_mode, |
2178 | "Return machine mode to be used for @code{_Unwind_Word} type.\n\ |
2179 | The default is to use @code{word_mode}." , |
2180 | scalar_int_mode, (void), |
2181 | default_unwind_word_mode) |
2182 | |
2183 | /* Given two decls, merge their attributes and return the result. */ |
2184 | DEFHOOK |
2185 | (merge_decl_attributes, |
2186 | "Define this target hook if the merging of decl attributes needs special\n\ |
2187 | handling. If defined, the result is a list of the combined\n\ |
2188 | @code{DECL_ATTRIBUTES} of @var{olddecl} and @var{newdecl}.\n\ |
2189 | @var{newdecl} is a duplicate declaration of @var{olddecl}. Examples of\n\ |
2190 | when this is needed are when one attribute overrides another, or when an\n\ |
2191 | attribute is nullified by a subsequent definition. This function may\n\ |
2192 | call @code{merge_attributes} to handle machine-independent merging.\n\ |
2193 | \n\ |
2194 | @findex TARGET_DLLIMPORT_DECL_ATTRIBUTES\n\ |
2195 | If the only target-specific handling you require is @samp{dllimport}\n\ |
2196 | for Microsoft Windows targets, you should define the macro\n\ |
2197 | @code{TARGET_DLLIMPORT_DECL_ATTRIBUTES} to @code{1}. The compiler\n\ |
2198 | will then define a function called\n\ |
2199 | @code{merge_dllimport_decl_attributes} which can then be defined as\n\ |
2200 | the expansion of @code{TARGET_MERGE_DECL_ATTRIBUTES}. You can also\n\ |
2201 | add @code{handle_dll_attribute} in the attribute table for your port\n\ |
2202 | to perform initial processing of the @samp{dllimport} and\n\ |
2203 | @samp{dllexport} attributes. This is done in @file{i386/cygwin.h} and\n\ |
2204 | @file{i386/i386.cc}, for example." , |
2205 | tree, (tree olddecl, tree newdecl), |
2206 | merge_decl_attributes) |
2207 | |
2208 | /* Given two types, merge their attributes and return the result. */ |
2209 | DEFHOOK |
2210 | (merge_type_attributes, |
2211 | "Define this target hook if the merging of type attributes needs special\n\ |
2212 | handling. If defined, the result is a list of the combined\n\ |
2213 | @code{TYPE_ATTRIBUTES} of @var{type1} and @var{type2}. It is assumed\n\ |
2214 | that @code{comptypes} has already been called and returned 1. This\n\ |
2215 | function may call @code{merge_attributes} to handle machine-independent\n\ |
2216 | merging." , |
2217 | tree, (tree type1, tree type2), |
2218 | merge_type_attributes) |
2219 | |
2220 | /* Table of machine attributes and functions to handle them. |
2221 | Ignored if NULL. */ |
2222 | DEFHOOKPOD |
2223 | (attribute_table, |
2224 | "If defined, this target hook points to an array of @samp{struct\n\ |
2225 | attribute_spec} (defined in @file{tree-core.h}) specifying the machine\n\ |
2226 | specific attributes for this target and some of the restrictions on the\n\ |
2227 | entities to which these attributes are applied and the arguments they\n\ |
2228 | take." , |
2229 | const struct attribute_spec *, NULL) |
2230 | |
2231 | /* Return true iff attribute NAME expects a plain identifier as its first |
2232 | argument. */ |
2233 | DEFHOOK |
2234 | (attribute_takes_identifier_p, |
2235 | "If defined, this target hook is a function which returns true if the\n\ |
2236 | machine-specific attribute named @var{name} expects an identifier\n\ |
2237 | given as its first argument to be passed on as a plain identifier, not\n\ |
2238 | subjected to name lookup. If this is not defined, the default is\n\ |
2239 | false for all machine-specific attributes." , |
2240 | bool, (const_tree name), |
2241 | hook_bool_const_tree_false) |
2242 | |
2243 | /* Return zero if the attributes on TYPE1 and TYPE2 are incompatible, |
2244 | one if they are compatible and two if they are nearly compatible |
2245 | (which causes a warning to be generated). */ |
2246 | DEFHOOK |
2247 | (comp_type_attributes, |
2248 | "If defined, this target hook is a function which returns zero if the attributes on\n\ |
2249 | @var{type1} and @var{type2} are incompatible, one if they are compatible,\n\ |
2250 | and two if they are nearly compatible (which causes a warning to be\n\ |
2251 | generated). If this is not defined, machine-specific attributes are\n\ |
2252 | supposed always to be compatible." , |
2253 | int, (const_tree type1, const_tree type2), |
2254 | hook_int_const_tree_const_tree_1) |
2255 | |
2256 | /* Assign default attributes to the newly defined TYPE. */ |
2257 | DEFHOOK |
2258 | (set_default_type_attributes, |
2259 | "If defined, this target hook is a function which assigns default attributes to\n\ |
2260 | the newly defined @var{type}." , |
2261 | void, (tree type), |
2262 | hook_void_tree) |
2263 | |
2264 | /* Insert attributes on the newly created DECL. */ |
2265 | DEFHOOK |
2266 | (insert_attributes, |
2267 | "Define this target hook if you want to be able to add attributes to a decl\n\ |
2268 | when it is being created. This is normally useful for back ends which\n\ |
2269 | wish to implement a pragma by using the attributes which correspond to\n\ |
2270 | the pragma's effect. The @var{node} argument is the decl which is being\n\ |
2271 | created. The @var{attr_ptr} argument is a pointer to the attribute list\n\ |
2272 | for this decl. The list itself should not be modified, since it may be\n\ |
2273 | shared with other decls, but attributes may be chained on the head of\n\ |
2274 | the list and @code{*@var{attr_ptr}} modified to point to the new\n\ |
2275 | attributes, or a copy of the list may be made if further changes are\n\ |
2276 | needed." , |
2277 | void, (tree node, tree *attr_ptr), |
2278 | hook_void_tree_treeptr) |
2279 | |
2280 | /* Perform additional target-specific processing of generic attributes. */ |
2281 | DEFHOOK |
2282 | (handle_generic_attribute, |
2283 | "Define this target hook if you want to be able to perform additional\n\ |
2284 | target-specific processing of an attribute which is handled generically\n\ |
2285 | by a front end. The arguments are the same as those which are passed to\n\ |
2286 | attribute handlers. So far this only affects the @var{noinit} and\n\ |
2287 | @var{section} attribute." , |
2288 | tree, (tree *node, tree name, tree args, int flags, bool *no_add_attrs), |
2289 | hook_tree_treeptr_tree_tree_int_boolptr_null) |
2290 | |
2291 | /* Return true if FNDECL (which has at least one machine attribute) |
2292 | can be inlined despite its machine attributes, false otherwise. */ |
2293 | DEFHOOK |
2294 | (function_attribute_inlinable_p, |
2295 | "@cindex inlining\n\ |
2296 | This target hook returns @code{true} if it is OK to inline @var{fndecl}\n\ |
2297 | into the current function, despite its having target-specific\n\ |
2298 | attributes, @code{false} otherwise. By default, if a function has a\n\ |
2299 | target specific attribute attached to it, it will not be inlined." , |
2300 | bool, (const_tree fndecl), |
2301 | hook_bool_const_tree_false) |
2302 | |
2303 | /* Return true if bitfields in RECORD_TYPE should follow the |
2304 | Microsoft Visual C++ bitfield layout rules. */ |
2305 | DEFHOOK |
2306 | (ms_bitfield_layout_p, |
2307 | "This target hook returns @code{true} if bit-fields in the given\n\ |
2308 | @var{record_type} are to be laid out following the rules of Microsoft\n\ |
2309 | Visual C/C++, namely: (i) a bit-field won't share the same storage\n\ |
2310 | unit with the previous bit-field if their underlying types have\n\ |
2311 | different sizes, and the bit-field will be aligned to the highest\n\ |
2312 | alignment of the underlying types of itself and of the previous\n\ |
2313 | bit-field; (ii) a zero-sized bit-field will affect the alignment of\n\ |
2314 | the whole enclosing structure, even if it is unnamed; except that\n\ |
2315 | (iii) a zero-sized bit-field will be disregarded unless it follows\n\ |
2316 | another bit-field of nonzero size. If this hook returns @code{true},\n\ |
2317 | other macros that control bit-field layout are ignored.\n\ |
2318 | \n\ |
2319 | When a bit-field is inserted into a packed record, the whole size\n\ |
2320 | of the underlying type is used by one or more same-size adjacent\n\ |
2321 | bit-fields (that is, if its long:3, 32 bits is used in the record,\n\ |
2322 | and any additional adjacent long bit-fields are packed into the same\n\ |
2323 | chunk of 32 bits. However, if the size changes, a new field of that\n\ |
2324 | size is allocated). In an unpacked record, this is the same as using\n\ |
2325 | alignment, but not equivalent when packing.\n\ |
2326 | \n\ |
2327 | If both MS bit-fields and @samp{__attribute__((packed))} are used,\n\ |
2328 | the latter will take precedence. If @samp{__attribute__((packed))} is\n\ |
2329 | used on a single field when MS bit-fields are in use, it will take\n\ |
2330 | precedence for that field, but the alignment of the rest of the structure\n\ |
2331 | may affect its placement." , |
2332 | bool, (const_tree record_type), |
2333 | hook_bool_const_tree_false) |
2334 | |
2335 | /* For now this is only an interface to WORDS_BIG_ENDIAN for |
2336 | target-independent code like the front ends, need performance testing |
2337 | before switching completely to the target hook. */ |
2338 | DEFHOOK_UNDOC |
2339 | (words_big_endian, |
2340 | "" , |
2341 | bool, (void), |
2342 | targhook_words_big_endian) |
2343 | |
2344 | /* Likewise for FLOAT_WORDS_BIG_ENDIAN. */ |
2345 | DEFHOOK_UNDOC |
2346 | (float_words_big_endian, |
2347 | "" , |
2348 | bool, (void), |
2349 | targhook_float_words_big_endian) |
2350 | |
2351 | DEFHOOK |
2352 | (float_exceptions_rounding_supported_p, |
2353 | "Returns true if the target supports IEEE 754 floating-point exceptions\n\ |
2354 | and rounding modes, false otherwise. This is intended to relate to the\n\ |
2355 | @code{float} and @code{double} types, but not necessarily @code{long double}.\n\ |
2356 | By default, returns true if the @code{adddf3} instruction pattern is\n\ |
2357 | available and false otherwise, on the assumption that hardware floating\n\ |
2358 | point supports exceptions and rounding modes but software floating point\n\ |
2359 | does not." , |
2360 | bool, (void), |
2361 | default_float_exceptions_rounding_supported_p) |
2362 | |
2363 | /* True if the target supports decimal floating point. */ |
2364 | DEFHOOK |
2365 | (decimal_float_supported_p, |
2366 | "Returns true if the target supports decimal floating point." , |
2367 | bool, (void), |
2368 | default_decimal_float_supported_p) |
2369 | |
2370 | /* True if the target supports fixed-point. */ |
2371 | DEFHOOK |
2372 | (fixed_point_supported_p, |
2373 | "Returns true if the target supports fixed-point arithmetic." , |
2374 | bool, (void), |
2375 | default_fixed_point_supported_p) |
2376 | |
2377 | /* Return true if anonymous bitfields affect structure alignment. */ |
2378 | DEFHOOK |
2379 | (align_anon_bitfield, |
2380 | "When @code{PCC_BITFIELD_TYPE_MATTERS} is true this hook will determine\n\ |
2381 | whether unnamed bitfields affect the alignment of the containing\n\ |
2382 | structure. The hook should return true if the structure should inherit\n\ |
2383 | the alignment requirements of an unnamed bitfield's type." , |
2384 | bool, (void), |
2385 | hook_bool_void_false) |
2386 | |
2387 | /* Return true if volatile bitfields should use the narrowest type possible. |
2388 | Return false if they should use the container type. */ |
2389 | DEFHOOK |
2390 | (narrow_volatile_bitfield, |
2391 | "This target hook should return @code{true} if accesses to volatile bitfields\n\ |
2392 | should use the narrowest mode possible. It should return @code{false} if\n\ |
2393 | these accesses should use the bitfield container type.\n\ |
2394 | \n\ |
2395 | The default is @code{false}." , |
2396 | bool, (void), |
2397 | hook_bool_void_false) |
2398 | |
2399 | /* Set up target-specific built-in functions. */ |
2400 | DEFHOOK |
2401 | (init_builtins, |
2402 | "Define this hook if you have any machine-specific built-in functions\n\ |
2403 | that need to be defined. It should be a function that performs the\n\ |
2404 | necessary setup.\n\ |
2405 | \n\ |
2406 | Machine specific built-in functions can be useful to expand special machine\n\ |
2407 | instructions that would otherwise not normally be generated because\n\ |
2408 | they have no equivalent in the source language (for example, SIMD vector\n\ |
2409 | instructions or prefetch instructions).\n\ |
2410 | \n\ |
2411 | To create a built-in function, call the function\n\ |
2412 | @code{lang_hooks.builtin_function}\n\ |
2413 | which is defined by the language front end. You can use any type nodes set\n\ |
2414 | up by @code{build_common_tree_nodes};\n\ |
2415 | only language front ends that use those two functions will call\n\ |
2416 | @samp{TARGET_INIT_BUILTINS}." , |
2417 | void, (void), |
2418 | hook_void_void) |
2419 | |
2420 | /* Initialize (if INITIALIZE_P is true) and return the target-specific |
2421 | built-in function decl for CODE. |
2422 | Return NULL if that is not possible. Return error_mark_node if CODE |
2423 | is outside of the range of valid target builtin function codes. */ |
2424 | DEFHOOK |
2425 | (builtin_decl, |
2426 | "Define this hook if you have any machine-specific built-in functions\n\ |
2427 | that need to be defined. It should be a function that returns the\n\ |
2428 | builtin function declaration for the builtin function code @var{code}.\n\ |
2429 | If there is no such builtin and it cannot be initialized at this time\n\ |
2430 | if @var{initialize_p} is true the function should return @code{NULL_TREE}.\n\ |
2431 | If @var{code} is out of range the function should return\n\ |
2432 | @code{error_mark_node}." , |
2433 | tree, (unsigned code, bool initialize_p), NULL) |
2434 | |
2435 | /* Expand a target-specific builtin. */ |
2436 | DEFHOOK |
2437 | (expand_builtin, |
2438 | "\n\ |
2439 | Expand a call to a machine specific built-in function that was set up by\n\ |
2440 | @samp{TARGET_INIT_BUILTINS}. @var{exp} is the expression for the\n\ |
2441 | function call; the result should go to @var{target} if that is\n\ |
2442 | convenient, and have mode @var{mode} if that is convenient.\n\ |
2443 | @var{subtarget} may be used as the target for computing one of\n\ |
2444 | @var{exp}'s operands. @var{ignore} is nonzero if the value is to be\n\ |
2445 | ignored. This function should return the result of the call to the\n\ |
2446 | built-in function." , |
2447 | rtx, |
2448 | (tree exp, rtx target, rtx subtarget, machine_mode mode, int ignore), |
2449 | default_expand_builtin) |
2450 | |
2451 | /* Select a replacement for a target-specific builtin. This is done |
2452 | *before* regular type checking, and so allows the target to |
2453 | implement a crude form of function overloading. The result is a |
2454 | complete expression that implements the operation. PARAMS really |
2455 | has type VEC(tree,gc)*, but we don't want to include tree.h here. */ |
2456 | DEFHOOK |
2457 | (resolve_overloaded_builtin, |
2458 | "Select a replacement for a machine specific built-in function that\n\ |
2459 | was set up by @samp{TARGET_INIT_BUILTINS}. This is done\n\ |
2460 | @emph{before} regular type checking, and so allows the target to\n\ |
2461 | implement a crude form of function overloading. @var{fndecl} is the\n\ |
2462 | declaration of the built-in function. @var{arglist} is the list of\n\ |
2463 | arguments passed to the built-in function. The result is a\n\ |
2464 | complete expression that implements the operation, usually\n\ |
2465 | another @code{CALL_EXPR}.\n\ |
2466 | @var{arglist} really has type @samp{VEC(tree,gc)*}" , |
2467 | tree, (unsigned int /*location_t*/ loc, tree fndecl, void *arglist), NULL) |
2468 | |
2469 | DEFHOOK |
2470 | (check_builtin_call, |
2471 | "Perform semantic checking on a call to a machine-specific built-in\n\ |
2472 | function after its arguments have been constrained to the function\n\ |
2473 | signature. Return true if the call is valid, otherwise report an error\n\ |
2474 | and return false.\n\ |
2475 | \n\ |
2476 | This hook is called after @code{TARGET_RESOLVE_OVERLOADED_BUILTIN}.\n\ |
2477 | The call was originally to built-in function @var{orig_fndecl},\n\ |
2478 | but after the optional @code{TARGET_RESOLVE_OVERLOADED_BUILTIN}\n\ |
2479 | step is now to built-in function @var{fndecl}. @var{loc} is the\n\ |
2480 | location of the call and @var{args} is an array of function arguments,\n\ |
2481 | of which there are @var{nargs}. @var{arg_loc} specifies the location\n\ |
2482 | of each argument." , |
2483 | bool, (location_t loc, vec<location_t> arg_loc, tree fndecl, |
2484 | tree orig_fndecl, unsigned int nargs, tree *args), |
2485 | NULL) |
2486 | |
2487 | /* Fold a target-specific builtin to a tree valid for both GIMPLE |
2488 | and GENERIC. */ |
2489 | DEFHOOK |
2490 | (fold_builtin, |
2491 | "Fold a call to a machine specific built-in function that was set up by\n\ |
2492 | @samp{TARGET_INIT_BUILTINS}. @var{fndecl} is the declaration of the\n\ |
2493 | built-in function. @var{n_args} is the number of arguments passed to\n\ |
2494 | the function; the arguments themselves are pointed to by @var{argp}.\n\ |
2495 | The result is another tree, valid for both GIMPLE and GENERIC,\n\ |
2496 | containing a simplified expression for the call's result. If\n\ |
2497 | @var{ignore} is true the value will be ignored." , |
2498 | tree, (tree fndecl, int n_args, tree *argp, bool ignore), |
2499 | hook_tree_tree_int_treep_bool_null) |
2500 | |
2501 | /* Fold a target-specific builtin to a valid GIMPLE tree. */ |
2502 | DEFHOOK |
2503 | (gimple_fold_builtin, |
2504 | "Fold a call to a machine specific built-in function that was set up\n\ |
2505 | by @samp{TARGET_INIT_BUILTINS}. @var{gsi} points to the gimple\n\ |
2506 | statement holding the function call. Returns true if any change\n\ |
2507 | was made to the GIMPLE stream." , |
2508 | bool, (gimple_stmt_iterator *gsi), |
2509 | hook_bool_gsiptr_false) |
2510 | |
2511 | /* Target hook is used to compare the target attributes in two functions to |
2512 | determine which function's features get higher priority. This is used |
2513 | during function multi-versioning to figure out the order in which two |
2514 | versions must be dispatched. A function version with a higher priority |
2515 | is checked for dispatching earlier. DECL1 and DECL2 are |
2516 | the two function decls that will be compared. It returns positive value |
2517 | if DECL1 is higher priority, negative value if DECL2 is higher priority |
2518 | and 0 if they are the same. */ |
2519 | DEFHOOK |
2520 | (compare_version_priority, |
2521 | "This hook is used to compare the target attributes in two functions to\n\ |
2522 | determine which function's features get higher priority. This is used\n\ |
2523 | during function multi-versioning to figure out the order in which two\n\ |
2524 | versions must be dispatched. A function version with a higher priority\n\ |
2525 | is checked for dispatching earlier. @var{decl1} and @var{decl2} are\n\ |
2526 | the two function decls that will be compared." , |
2527 | int, (tree decl1, tree decl2), NULL) |
2528 | |
2529 | /* Target hook is used to generate the dispatcher logic to invoke the right |
2530 | function version at run-time for a given set of function versions. |
2531 | ARG points to the callgraph node of the dispatcher function whose body |
2532 | must be generated. */ |
2533 | DEFHOOK |
2534 | (generate_version_dispatcher_body, |
2535 | "This hook is used to generate the dispatcher logic to invoke the right\n\ |
2536 | function version at run-time for a given set of function versions.\n\ |
2537 | @var{arg} points to the callgraph node of the dispatcher function whose\n\ |
2538 | body must be generated." , |
2539 | tree, (void *arg), NULL) |
2540 | |
2541 | /* Target hook is used to get the dispatcher function for a set of function |
2542 | versions. The dispatcher function is called to invoke the right function |
2543 | version at run-time. DECL is one version from a set of semantically |
2544 | identical versions. */ |
2545 | DEFHOOK |
2546 | (get_function_versions_dispatcher, |
2547 | "This hook is used to get the dispatcher function for a set of function\n\ |
2548 | versions. The dispatcher function is called to invoke the right function\n\ |
2549 | version at run-time. @var{decl} is one version from a set of semantically\n\ |
2550 | identical versions." , |
2551 | tree, (void *decl), NULL) |
2552 | |
2553 | /* Returns a code for a target-specific builtin that implements |
2554 | reciprocal of a target-specific function, or NULL_TREE if not available. */ |
2555 | DEFHOOK |
2556 | (builtin_reciprocal, |
2557 | "This hook should return the DECL of a function that implements the\n\ |
2558 | reciprocal of the machine-specific builtin function @var{fndecl}, or\n\ |
2559 | @code{NULL_TREE} if such a function is not available." , |
2560 | tree, (tree fndecl), |
2561 | default_builtin_reciprocal) |
2562 | |
2563 | /* For a vendor-specific TYPE, return a pointer to a statically-allocated |
2564 | string containing the C++ mangling for TYPE. In all other cases, return |
2565 | NULL. */ |
2566 | DEFHOOK |
2567 | (mangle_type, |
2568 | "If your target defines any fundamental types, or any types your target\n\ |
2569 | uses should be mangled differently from the default, define this hook\n\ |
2570 | to return the appropriate encoding for these types as part of a C++\n\ |
2571 | mangled name. The @var{type} argument is the tree structure representing\n\ |
2572 | the type to be mangled. The hook may be applied to trees which are\n\ |
2573 | not target-specific fundamental types; it should return @code{NULL}\n\ |
2574 | for all such types, as well as arguments it does not recognize. If the\n\ |
2575 | return value is not @code{NULL}, it must point to a statically-allocated\n\ |
2576 | string constant.\n\ |
2577 | \n\ |
2578 | Target-specific fundamental types might be new fundamental types or\n\ |
2579 | qualified versions of ordinary fundamental types. Encode new\n\ |
2580 | fundamental types as @samp{@w{u @var{n} @var{name}}}, where @var{name}\n\ |
2581 | is the name used for the type in source code, and @var{n} is the\n\ |
2582 | length of @var{name} in decimal. Encode qualified versions of\n\ |
2583 | ordinary types as @samp{@w{U @var{n} @var{name} @var{code}}}, where\n\ |
2584 | @var{name} is the name used for the type qualifier in source code,\n\ |
2585 | @var{n} is the length of @var{name} as above, and @var{code} is the\n\ |
2586 | code used to represent the unqualified version of this type. (See\n\ |
2587 | @code{write_builtin_type} in @file{cp/mangle.cc} for the list of\n\ |
2588 | codes.) In both cases the spaces are for clarity; do not include any\n\ |
2589 | spaces in your string.\n\ |
2590 | \n\ |
2591 | This hook is applied to types prior to typedef resolution. If the mangled\n\ |
2592 | name for a particular type depends only on that type's main variant, you\n\ |
2593 | can perform typedef resolution yourself using @code{TYPE_MAIN_VARIANT}\n\ |
2594 | before mangling.\n\ |
2595 | \n\ |
2596 | The default version of this hook always returns @code{NULL}, which is\n\ |
2597 | appropriate for a target that does not define any new fundamental\n\ |
2598 | types." , |
2599 | const char *, (const_tree type), |
2600 | hook_constcharptr_const_tree_null) |
2601 | |
2602 | /* Temporarily add conditional target specific types for the purpose of |
2603 | emitting C++ fundamental type tinfos. */ |
2604 | DEFHOOK |
2605 | (emit_support_tinfos, |
2606 | "If your target defines any fundamental types which depend on ISA flags,\n\ |
2607 | they might need C++ tinfo symbols in libsupc++/libstdc++ regardless of\n\ |
2608 | ISA flags the library is compiled with.\n\ |
2609 | This hook allows creating tinfo symbols even for those cases, by temporarily\n\ |
2610 | creating each corresponding fundamental type trees, calling the\n\ |
2611 | @var{callback} function on it and setting the type back to @code{nullptr}." , |
2612 | void, (emit_support_tinfos_callback callback), |
2613 | default_emit_support_tinfos) |
2614 | |
2615 | /* Make any adjustments to libfunc names needed for this target. */ |
2616 | DEFHOOK |
2617 | (init_libfuncs, |
2618 | "This hook should declare additional library routines or rename\n\ |
2619 | existing ones, using the functions @code{set_optab_libfunc} and\n\ |
2620 | @code{init_one_libfunc} defined in @file{optabs.cc}.\n\ |
2621 | @code{init_optabs} calls this macro after initializing all the normal\n\ |
2622 | library routines.\n\ |
2623 | \n\ |
2624 | The default is to do nothing. Most ports don't need to define this hook." , |
2625 | void, (void), |
2626 | hook_void_void) |
2627 | |
2628 | /* Add a __gnu_ prefix to library functions rather than just __. */ |
2629 | DEFHOOKPOD |
2630 | (libfunc_gnu_prefix, |
2631 | "If false (the default), internal library routines start with two\n\ |
2632 | underscores. If set to true, these routines start with @code{__gnu_}\n\ |
2633 | instead. E.g., @code{__muldi3} changes to @code{__gnu_muldi3}. This\n\ |
2634 | currently only affects functions defined in @file{libgcc2.c}. If this\n\ |
2635 | is set to true, the @file{tm.h} file must also\n\ |
2636 | @code{#define LIBGCC2_GNU_PREFIX}." , |
2637 | bool, false) |
2638 | |
2639 | /* Given a decl, a section name, and whether the decl initializer |
2640 | has relocs, choose attributes for the section. */ |
2641 | /* ??? Should be merged with SELECT_SECTION and UNIQUE_SECTION. */ |
2642 | DEFHOOK |
2643 | (section_type_flags, |
2644 | "Choose a set of section attributes for use by @code{TARGET_ASM_NAMED_SECTION}\n\ |
2645 | based on a variable or function decl, a section name, and whether or not the\n\ |
2646 | declaration's initializer may contain runtime relocations. @var{decl} may be\n\ |
2647 | null, in which case read-write data should be assumed.\n\ |
2648 | \n\ |
2649 | The default version of this function handles choosing code vs data,\n\ |
2650 | read-only vs read-write data, and @code{flag_pic}. You should only\n\ |
2651 | need to override this if your target has special flags that might be\n\ |
2652 | set via @code{__attribute__}." , |
2653 | unsigned int, (tree decl, const char *name, int reloc), |
2654 | default_section_type_flags) |
2655 | |
2656 | DEFHOOK |
2657 | (libc_has_function, |
2658 | "This hook determines whether a function from a class of functions\n\ |
2659 | @var{fn_class} is present in the target C library. If @var{type} is NULL,\n\ |
2660 | the caller asks for support for all standard (float, double, long double)\n\ |
2661 | types. If @var{type} is non-NULL, the caller asks for support for a\n\ |
2662 | specific type." , |
2663 | bool, (enum function_class fn_class, tree type), |
2664 | default_libc_has_function) |
2665 | |
2666 | DEFHOOK |
2667 | (libc_has_fast_function, |
2668 | "This hook determines whether a function from a class of functions\n\ |
2669 | @code{(enum function_class)}@var{fcode} has a fast implementation." , |
2670 | bool, (int fcode), |
2671 | default_libc_has_fast_function) |
2672 | |
2673 | DEFHOOK |
2674 | (libm_function_max_error, |
2675 | "This hook determines expected maximum errors for math functions measured\n\ |
2676 | in ulps (units of the last place). 0 means 0.5ulps precision (correctly\n\ |
2677 | rounded). ~0U means unknown errors. The @code{combined_fn} @var{cfn}\n\ |
2678 | argument should identify just which math built-in function it is rather than\n\ |
2679 | its variant, @var{mode} the variant in terms of floating-point machine mode.\n\ |
2680 | The hook should also take into account @code{flag_rounding_math} whether it\n\ |
2681 | is maximum error just in default rounding mode, or in all possible rounding\n\ |
2682 | modes. @var{boundary_p} is @code{true} for maximum errors on intrinsic math\n\ |
2683 | boundaries of functions rather than errors inside of the usual result ranges\n\ |
2684 | of the functions. E.g.@ the sin/cos function finite result is in between\n\ |
2685 | -1.0 and 1.0 inclusive, with @var{boundary_p} true the function returns how\n\ |
2686 | many ulps below or above those boundaries result could be." , |
2687 | unsigned, (unsigned cfn, machine_mode mode, bool boundary_p), |
2688 | default_libm_function_max_error) |
2689 | |
2690 | /* True if new jumps cannot be created, to replace existing ones or |
2691 | not, at the current point in the compilation. */ |
2692 | DEFHOOK |
2693 | (cannot_modify_jumps_p, |
2694 | "This target hook returns @code{true} past the point in which new jump\n\ |
2695 | instructions could be created. On machines that require a register for\n\ |
2696 | every jump such as the SHmedia ISA of SH5, this point would typically be\n\ |
2697 | reload, so this target hook should be defined to a function such as:\n\ |
2698 | \n\ |
2699 | @smallexample\n\ |
2700 | static bool\n\ |
2701 | cannot_modify_jumps_past_reload_p ()\n\ |
2702 | @{\n\ |
2703 | return (reload_completed || reload_in_progress);\n\ |
2704 | @}\n\ |
2705 | @end smallexample" , |
2706 | bool, (void), |
2707 | hook_bool_void_false) |
2708 | |
2709 | /* True if FOLLOWER may be modified to follow FOLLOWEE. */ |
2710 | DEFHOOK |
2711 | (can_follow_jump, |
2712 | "FOLLOWER and FOLLOWEE are JUMP_INSN instructions;\n\ |
2713 | return true if FOLLOWER may be modified to follow FOLLOWEE;\n\ |
2714 | false, if it can't.\n\ |
2715 | For example, on some targets, certain kinds of branches can't be made to\n\ |
2716 | follow through a hot/cold partitioning." , |
2717 | bool, (const rtx_insn *follower, const rtx_insn *followee), |
2718 | hook_bool_const_rtx_insn_const_rtx_insn_true) |
2719 | |
2720 | /* Return true if the target supports conditional execution. */ |
2721 | DEFHOOK |
2722 | (have_conditional_execution, |
2723 | "This target hook returns true if the target supports conditional execution.\n\ |
2724 | This target hook is required only when the target has several different\n\ |
2725 | modes and they have different conditional execution capability, such as ARM." , |
2726 | bool, (void), |
2727 | default_have_conditional_execution) |
2728 | |
2729 | DEFHOOK |
2730 | (gen_ccmp_first, |
2731 | "This function prepares to emit a comparison insn for the first compare in a\n\ |
2732 | sequence of conditional comparisions. It returns an appropriate comparison\n\ |
2733 | with @code{CC} for passing to @code{gen_ccmp_next} or @code{cbranch_optab}.\n\ |
2734 | The insns to prepare the compare are saved in @var{prep_seq} and the compare\n\ |
2735 | insns are saved in @var{gen_seq}. They will be emitted when all the\n\ |
2736 | compares in the conditional comparision are generated without error.\n\ |
2737 | @var{code} is the @code{rtx_code} of the compare for @var{op0} and @var{op1}." , |
2738 | rtx, (rtx_insn **prep_seq, rtx_insn **gen_seq, rtx_code code, tree op0, tree op1), |
2739 | NULL) |
2740 | |
2741 | DEFHOOK |
2742 | (gen_ccmp_next, |
2743 | "This function prepares to emit a conditional comparison within a sequence\n\ |
2744 | of conditional comparisons. It returns an appropriate comparison with\n\ |
2745 | @code{CC} for passing to @code{gen_ccmp_next} or @code{cbranch_optab}.\n\ |
2746 | The insns to prepare the compare are saved in @var{prep_seq} and the compare\n\ |
2747 | insns are saved in @var{gen_seq}. They will be emitted when all the\n\ |
2748 | compares in the conditional comparision are generated without error. The\n\ |
2749 | @var{prev} expression is the result of a prior call to @code{gen_ccmp_first}\n\ |
2750 | or @code{gen_ccmp_next}. It may return @code{NULL} if the combination of\n\ |
2751 | @var{prev} and this comparison is not supported, otherwise the result must\n\ |
2752 | be appropriate for passing to @code{gen_ccmp_next} or @code{cbranch_optab}.\n\ |
2753 | @var{code} is the @code{rtx_code} of the compare for @var{op0} and @var{op1}.\n\ |
2754 | @var{bit_code} is @code{AND} or @code{IOR}, which is the op on the compares." , |
2755 | rtx, (rtx_insn **prep_seq, rtx_insn **gen_seq, rtx prev, rtx_code cmp_code, tree op0, tree op1, rtx_code bit_code), |
2756 | NULL) |
2757 | |
2758 | /* Return a new value for loop unroll size. */ |
2759 | DEFHOOK |
2760 | (loop_unroll_adjust, |
2761 | "This target hook returns a new value for the number of times @var{loop}\n\ |
2762 | should be unrolled. The parameter @var{nunroll} is the number of times\n\ |
2763 | the loop is to be unrolled. The parameter @var{loop} is a pointer to\n\ |
2764 | the loop, which is going to be checked for unrolling. This target hook\n\ |
2765 | is required only when the target has special constraints like maximum\n\ |
2766 | number of memory accesses." , |
2767 | unsigned, (unsigned nunroll, class loop *loop), |
2768 | NULL) |
2769 | |
2770 | /* True if X is a legitimate MODE-mode immediate operand. */ |
2771 | DEFHOOK |
2772 | (legitimate_constant_p, |
2773 | "This hook returns true if @var{x} is a legitimate constant for a\n\ |
2774 | @var{mode}-mode immediate operand on the target machine. You can assume that\n\ |
2775 | @var{x} satisfies @code{CONSTANT_P}, so you need not check this.\n\ |
2776 | \n\ |
2777 | The default definition returns true." , |
2778 | bool, (machine_mode mode, rtx x), |
2779 | hook_bool_mode_rtx_true) |
2780 | |
2781 | /* True if X is a TLS operand whose value should be pre-computed. */ |
2782 | DEFHOOK |
2783 | (precompute_tls_p, |
2784 | "This hook returns true if @var{x} is a TLS operand on the target\n\ |
2785 | machine that should be pre-computed when used as the argument in a call.\n\ |
2786 | You can assume that @var{x} satisfies @code{CONSTANT_P}, so you need not \n\ |
2787 | check this.\n\ |
2788 | \n\ |
2789 | The default definition returns false." , |
2790 | bool, (machine_mode mode, rtx x), |
2791 | hook_bool_mode_rtx_false) |
2792 | |
2793 | /* True if the constant X cannot be placed in the constant pool. */ |
2794 | DEFHOOK |
2795 | (cannot_force_const_mem, |
2796 | "This hook should return true if @var{x} is of a form that cannot (or\n\ |
2797 | should not) be spilled to the constant pool. @var{mode} is the mode\n\ |
2798 | of @var{x}.\n\ |
2799 | \n\ |
2800 | The default version of this hook returns false.\n\ |
2801 | \n\ |
2802 | The primary reason to define this hook is to prevent reload from\n\ |
2803 | deciding that a non-legitimate constant would be better reloaded\n\ |
2804 | from the constant pool instead of spilling and reloading a register\n\ |
2805 | holding the constant. This restriction is often true of addresses\n\ |
2806 | of TLS symbols for various targets." , |
2807 | bool, (machine_mode mode, rtx x), |
2808 | hook_bool_mode_rtx_false) |
2809 | |
2810 | DEFHOOK_UNDOC |
2811 | (cannot_copy_insn_p, |
2812 | "True if the insn @var{x} cannot be duplicated." , |
2813 | bool, (rtx_insn *), NULL) |
2814 | |
2815 | /* True if X is considered to be commutative. */ |
2816 | DEFHOOK |
2817 | (commutative_p, |
2818 | "This target hook returns @code{true} if @var{x} is considered to be commutative.\n\ |
2819 | Usually, this is just COMMUTATIVE_P (@var{x}), but the HP PA doesn't consider\n\ |
2820 | PLUS to be commutative inside a MEM@. @var{outer_code} is the rtx code\n\ |
2821 | of the enclosing rtl, if known, otherwise it is UNKNOWN." , |
2822 | bool, (const_rtx x, int outer_code), |
2823 | hook_bool_const_rtx_commutative_p) |
2824 | |
2825 | /* True if ADDR is an address-expression whose effect depends |
2826 | on the mode of the memory reference it is used in. */ |
2827 | DEFHOOK |
2828 | (mode_dependent_address_p, |
2829 | "This hook returns @code{true} if memory address @var{addr} in address\n\ |
2830 | space @var{addrspace} can have\n\ |
2831 | different meanings depending on the machine mode of the memory\n\ |
2832 | reference it is used for or if the address is valid for some modes\n\ |
2833 | but not others.\n\ |
2834 | \n\ |
2835 | Autoincrement and autodecrement addresses typically have mode-dependent\n\ |
2836 | effects because the amount of the increment or decrement is the size\n\ |
2837 | of the operand being addressed. Some machines have other mode-dependent\n\ |
2838 | addresses. Many RISC machines have no mode-dependent addresses.\n\ |
2839 | \n\ |
2840 | You may assume that @var{addr} is a valid address for the machine.\n\ |
2841 | \n\ |
2842 | The default version of this hook returns @code{false}." , |
2843 | bool, (const_rtx addr, addr_space_t addrspace), |
2844 | default_mode_dependent_address_p) |
2845 | |
2846 | /* Given an invalid address X for a given machine mode, try machine-specific |
2847 | ways to make it legitimate. Return X or an invalid address on failure. */ |
2848 | DEFHOOK |
2849 | (legitimize_address, |
2850 | "This hook is given an invalid memory address @var{x} for an\n\ |
2851 | operand of mode @var{mode} and should try to return a valid memory\n\ |
2852 | address.\n\ |
2853 | \n\ |
2854 | @findex break_out_memory_refs\n\ |
2855 | @var{x} will always be the result of a call to @code{break_out_memory_refs},\n\ |
2856 | and @var{oldx} will be the operand that was given to that function to produce\n\ |
2857 | @var{x}.\n\ |
2858 | \n\ |
2859 | The code of the hook should not alter the substructure of\n\ |
2860 | @var{x}. If it transforms @var{x} into a more legitimate form, it\n\ |
2861 | should return the new @var{x}.\n\ |
2862 | \n\ |
2863 | It is not necessary for this hook to come up with a legitimate address,\n\ |
2864 | with the exception of native TLS addresses (@pxref{Emulated TLS}).\n\ |
2865 | The compiler has standard ways of doing so in all cases. In fact, if\n\ |
2866 | the target supports only emulated TLS, it\n\ |
2867 | is safe to omit this hook or make it return @var{x} if it cannot find\n\ |
2868 | a valid way to legitimize the address. But often a machine-dependent\n\ |
2869 | strategy can generate better code." , |
2870 | rtx, (rtx x, rtx oldx, machine_mode mode), |
2871 | default_legitimize_address) |
2872 | |
2873 | /* Given an address RTX, undo the effects of LEGITIMIZE_ADDRESS. */ |
2874 | DEFHOOK |
2875 | (delegitimize_address, |
2876 | "This hook is used to undo the possibly obfuscating effects of the\n\ |
2877 | @code{LEGITIMIZE_ADDRESS} and @code{LEGITIMIZE_RELOAD_ADDRESS} target\n\ |
2878 | macros. Some backend implementations of these macros wrap symbol\n\ |
2879 | references inside an @code{UNSPEC} rtx to represent PIC or similar\n\ |
2880 | addressing modes. This target hook allows GCC's optimizers to understand\n\ |
2881 | the semantics of these opaque @code{UNSPEC}s by converting them back\n\ |
2882 | into their original form." , |
2883 | rtx, (rtx x), |
2884 | delegitimize_mem_from_attrs) |
2885 | |
2886 | /* Given an RTX, return true if it is not ok to emit it into debug info |
2887 | section. */ |
2888 | DEFHOOK |
2889 | (const_not_ok_for_debug_p, |
2890 | "This hook should return true if @var{x} should not be emitted into\n\ |
2891 | debug sections." , |
2892 | bool, (rtx x), |
2893 | default_const_not_ok_for_debug_p) |
2894 | |
2895 | /* Given an address RTX, say whether it is valid. */ |
2896 | DEFHOOK |
2897 | (legitimate_address_p, |
2898 | "A function that returns whether @var{x} (an RTX) is a legitimate memory\n\ |
2899 | address on the target machine for a memory operand of mode @var{mode}.\n\ |
2900 | If @var{ch} is not @code{ERROR_MARK}, it can be called from middle-end to\n\ |
2901 | determine if it is valid to use @var{x} as a memory operand for RTX insn\n\ |
2902 | which is generated for the given code_helper @var{ch}. For example,\n\ |
2903 | assuming the given @var{ch} is IFN_LEN_LOAD, on some target its underlying\n\ |
2904 | hardware instructions support fewer addressing modes than what are for the\n\ |
2905 | normal vector load and store, then with this @var{ch} target can know the\n\ |
2906 | actual use context and return more exact result.\n\ |
2907 | \n\ |
2908 | Legitimate addresses are defined in two variants: a strict variant and a\n\ |
2909 | non-strict one. The @var{strict} parameter chooses which variant is\n\ |
2910 | desired by the caller.\n\ |
2911 | \n\ |
2912 | The strict variant is used in the reload pass. It must be defined so\n\ |
2913 | that any pseudo-register that has not been allocated a hard register is\n\ |
2914 | considered a memory reference. This is because in contexts where some\n\ |
2915 | kind of register is required, a pseudo-register with no hard register\n\ |
2916 | must be rejected. For non-hard registers, the strict variant should look\n\ |
2917 | up the @code{reg_renumber} array; it should then proceed using the hard\n\ |
2918 | register number in the array, or treat the pseudo as a memory reference\n\ |
2919 | if the array holds @code{-1}.\n\ |
2920 | \n\ |
2921 | The non-strict variant is used in other passes. It must be defined to\n\ |
2922 | accept all pseudo-registers in every context where some kind of\n\ |
2923 | register is required.\n\ |
2924 | \n\ |
2925 | Normally, constant addresses which are the sum of a @code{symbol_ref}\n\ |
2926 | and an integer are stored inside a @code{const} RTX to mark them as\n\ |
2927 | constant. Therefore, there is no need to recognize such sums\n\ |
2928 | specifically as legitimate addresses. Normally you would simply\n\ |
2929 | recognize any @code{const} as legitimate.\n\ |
2930 | \n\ |
2931 | Usually @code{PRINT_OPERAND_ADDRESS} is not prepared to handle constant\n\ |
2932 | sums that are not marked with @code{const}. It assumes that a naked\n\ |
2933 | @code{plus} indicates indexing. If so, then you @emph{must} reject such\n\ |
2934 | naked constant sums as illegitimate addresses, so that none of them will\n\ |
2935 | be given to @code{PRINT_OPERAND_ADDRESS}.\n\ |
2936 | \n\ |
2937 | @cindex @code{TARGET_ENCODE_SECTION_INFO} and address validation\n\ |
2938 | On some machines, whether a symbolic address is legitimate depends on\n\ |
2939 | the section that the address refers to. On these machines, define the\n\ |
2940 | target hook @code{TARGET_ENCODE_SECTION_INFO} to store the information\n\ |
2941 | into the @code{symbol_ref}, and then check for it here. When you see a\n\ |
2942 | @code{const}, you will have to look inside it to find the\n\ |
2943 | @code{symbol_ref} in order to determine the section. @xref{Assembler\n\ |
2944 | Format}.\n\ |
2945 | \n\ |
2946 | @cindex @code{GO_IF_LEGITIMATE_ADDRESS}\n\ |
2947 | Some ports are still using a deprecated legacy substitute for\n\ |
2948 | this hook, the @code{GO_IF_LEGITIMATE_ADDRESS} macro. This macro\n\ |
2949 | has this syntax:\n\ |
2950 | \n\ |
2951 | @example\n\ |
2952 | #define GO_IF_LEGITIMATE_ADDRESS (@var{mode}, @var{x}, @var{label})\n\ |
2953 | @end example\n\ |
2954 | \n\ |
2955 | @noindent\n\ |
2956 | and should @code{goto @var{label}} if the address @var{x} is a valid\n\ |
2957 | address on the target machine for a memory operand of mode @var{mode}.\n\ |
2958 | \n\ |
2959 | @findex REG_OK_STRICT\n\ |
2960 | Compiler source files that want to use the strict variant of this\n\ |
2961 | macro define the macro @code{REG_OK_STRICT}. You should use an\n\ |
2962 | @code{#ifdef REG_OK_STRICT} conditional to define the strict variant in\n\ |
2963 | that case and the non-strict variant otherwise.\n\ |
2964 | \n\ |
2965 | Using the hook is usually simpler because it limits the number of\n\ |
2966 | files that are recompiled when changes are made." , |
2967 | bool, (machine_mode mode, rtx x, bool strict, code_helper ch), |
2968 | default_legitimate_address_p) |
2969 | |
2970 | /* True if the given constant can be put into an object_block. */ |
2971 | DEFHOOK |
2972 | (use_blocks_for_constant_p, |
2973 | "This hook should return true if pool entries for constant @var{x} can\n\ |
2974 | be placed in an @code{object_block} structure. @var{mode} is the mode\n\ |
2975 | of @var{x}.\n\ |
2976 | \n\ |
2977 | The default version returns false for all constants." , |
2978 | bool, (machine_mode mode, const_rtx x), |
2979 | hook_bool_mode_const_rtx_false) |
2980 | |
2981 | /* True if the given decl can be put into an object_block. */ |
2982 | DEFHOOK |
2983 | (use_blocks_for_decl_p, |
2984 | "This hook should return true if pool entries for @var{decl} should\n\ |
2985 | be placed in an @code{object_block} structure.\n\ |
2986 | \n\ |
2987 | The default version returns true for all decls." , |
2988 | bool, (const_tree decl), |
2989 | hook_bool_const_tree_true) |
2990 | |
2991 | /* The minimum and maximum byte offsets for anchored addresses. */ |
2992 | DEFHOOKPOD |
2993 | (min_anchor_offset, |
2994 | "The minimum offset that should be applied to a section anchor.\n\ |
2995 | On most targets, it should be the smallest offset that can be\n\ |
2996 | applied to a base register while still giving a legitimate address\n\ |
2997 | for every mode. The default value is 0." , |
2998 | HOST_WIDE_INT, 0) |
2999 | |
3000 | DEFHOOKPOD |
3001 | (max_anchor_offset, |
3002 | "Like @code{TARGET_MIN_ANCHOR_OFFSET}, but the maximum (inclusive)\n\ |
3003 | offset that should be applied to section anchors. The default\n\ |
3004 | value is 0." , |
3005 | HOST_WIDE_INT, 0) |
3006 | |
3007 | /* True if section anchors can be used to access the given symbol. */ |
3008 | DEFHOOK |
3009 | (use_anchors_for_symbol_p, |
3010 | "Return true if GCC should attempt to use anchors to access @code{SYMBOL_REF}\n\ |
3011 | @var{x}. You can assume @samp{SYMBOL_REF_HAS_BLOCK_INFO_P (@var{x})} and\n\ |
3012 | @samp{!SYMBOL_REF_ANCHOR_P (@var{x})}.\n\ |
3013 | \n\ |
3014 | The default version is correct for most targets, but you might need to\n\ |
3015 | intercept this hook to handle things like target-specific attributes\n\ |
3016 | or target-specific sections." , |
3017 | bool, (const_rtx x), |
3018 | default_use_anchors_for_symbol_p) |
3019 | |
3020 | /* True if target supports indirect functions. */ |
3021 | DEFHOOK |
3022 | (has_ifunc_p, |
3023 | "It returns true if the target supports GNU indirect functions.\n\ |
3024 | The support includes the assembler, linker and dynamic linker.\n\ |
3025 | The default value of this hook is based on target's libc." , |
3026 | bool, (void), |
3027 | default_has_ifunc_p) |
3028 | |
3029 | /* True if it is OK to reference indirect function resolvers locally. */ |
3030 | DEFHOOK |
3031 | (ifunc_ref_local_ok, |
3032 | "Return true if it is OK to reference indirect function resolvers\n\ |
3033 | locally. The default is to return false." , |
3034 | bool, (void), |
3035 | hook_bool_void_false) |
3036 | |
3037 | /* True if it is OK to do sibling call optimization for the specified |
3038 | call expression EXP. DECL will be the called function, or NULL if |
3039 | this is an indirect call. */ |
3040 | DEFHOOK |
3041 | (function_ok_for_sibcall, |
3042 | "True if it is OK to do sibling call optimization for the specified\n\ |
3043 | call expression @var{exp}. @var{decl} will be the called function,\n\ |
3044 | or @code{NULL} if this is an indirect call.\n\ |
3045 | \n\ |
3046 | It is not uncommon for limitations of calling conventions to prevent\n\ |
3047 | tail calls to functions outside the current unit of translation, or\n\ |
3048 | during PIC compilation. The hook is used to enforce these restrictions,\n\ |
3049 | as the @code{sibcall} md pattern cannot fail, or fall over to a\n\ |
3050 | ``normal'' call. The criteria for successful sibling call optimization\n\ |
3051 | may vary greatly between different architectures." , |
3052 | bool, (tree decl, tree exp), |
3053 | hook_bool_tree_tree_false) |
3054 | |
3055 | /* Establish appropriate back-end context for processing the function |
3056 | FNDECL. The argument might be NULL to indicate processing at top |
3057 | level, outside of any function scope. */ |
3058 | DEFHOOK |
3059 | (set_current_function, |
3060 | "The compiler invokes this hook whenever it changes its current function\n\ |
3061 | context (@code{cfun}). You can define this function if\n\ |
3062 | the back end needs to perform any initialization or reset actions on a\n\ |
3063 | per-function basis. For example, it may be used to implement function\n\ |
3064 | attributes that affect register usage or code generation patterns.\n\ |
3065 | The argument @var{decl} is the declaration for the new function context,\n\ |
3066 | and may be null to indicate that the compiler has left a function context\n\ |
3067 | and is returning to processing at the top level.\n\ |
3068 | The default hook function does nothing.\n\ |
3069 | \n\ |
3070 | GCC sets @code{cfun} to a dummy function context during initialization of\n\ |
3071 | some parts of the back end. The hook function is not invoked in this\n\ |
3072 | situation; you need not worry about the hook being invoked recursively,\n\ |
3073 | or when the back end is in a partially-initialized state.\n\ |
3074 | @code{cfun} might be @code{NULL} to indicate processing at top level,\n\ |
3075 | outside of any function scope." , |
3076 | void, (tree decl), hook_void_tree) |
3077 | |
3078 | /* True if EXP should be placed in a "small data" section. */ |
3079 | DEFHOOK |
3080 | (in_small_data_p, |
3081 | "Returns true if @var{exp} should be placed into a ``small data'' section.\n\ |
3082 | The default version of this hook always returns false." , |
3083 | bool, (const_tree exp), |
3084 | hook_bool_const_tree_false) |
3085 | |
3086 | /* True if EXP names an object for which name resolution must resolve |
3087 | to the current executable or shared library. */ |
3088 | DEFHOOK |
3089 | (binds_local_p, |
3090 | "Returns true if @var{exp} names an object for which name resolution\n\ |
3091 | rules must resolve to the current ``module'' (dynamic shared library\n\ |
3092 | or executable image).\n\ |
3093 | \n\ |
3094 | The default version of this hook implements the name resolution rules\n\ |
3095 | for ELF, which has a looser model of global name binding than other\n\ |
3096 | currently supported object file formats." , |
3097 | bool, (const_tree exp), |
3098 | default_binds_local_p) |
3099 | |
3100 | /* Check if profiling code is before or after prologue. */ |
3101 | DEFHOOK |
3102 | (profile_before_prologue, |
3103 | "It returns true if target wants profile code emitted before prologue.\n\n\ |
3104 | The default version of this hook use the target macro\n\ |
3105 | @code{PROFILE_BEFORE_PROLOGUE}." , |
3106 | bool, (void), |
3107 | default_profile_before_prologue) |
3108 | |
3109 | /* Return true if a leaf function should stay leaf even with profiling |
3110 | enabled. */ |
3111 | DEFHOOK |
3112 | (keep_leaf_when_profiled, |
3113 | "This target hook returns true if the target wants the leaf flag for\n\ |
3114 | the current function to stay true even if it calls mcount. This might\n\ |
3115 | make sense for targets using the leaf flag only to determine whether a\n\ |
3116 | stack frame needs to be generated or not and for which the call to\n\ |
3117 | mcount is generated before the function prologue." , |
3118 | bool, (void), |
3119 | default_keep_leaf_when_profiled) |
3120 | |
3121 | /* Modify and return the identifier of a DECL's external name, |
3122 | originally identified by ID, as required by the target, |
3123 | (eg, append @nn to windows32 stdcall function names). |
3124 | The default is to return ID without modification. */ |
3125 | DEFHOOK |
3126 | (mangle_decl_assembler_name, |
3127 | "Define this hook if you need to postprocess the assembler name generated\n\ |
3128 | by target-independent code. The @var{id} provided to this hook will be\n\ |
3129 | the computed name (e.g., the macro @code{DECL_NAME} of the @var{decl} in C,\n\ |
3130 | or the mangled name of the @var{decl} in C++). The return value of the\n\ |
3131 | hook is an @code{IDENTIFIER_NODE} for the appropriate mangled name on\n\ |
3132 | your target system. The default implementation of this hook just\n\ |
3133 | returns the @var{id} provided." , |
3134 | tree, (tree decl, tree id), |
3135 | default_mangle_decl_assembler_name) |
3136 | |
3137 | /* Do something target-specific to record properties of the DECL into |
3138 | the associated SYMBOL_REF. */ |
3139 | DEFHOOK |
3140 | (encode_section_info, |
3141 | "Define this hook if references to a symbol or a constant must be\n\ |
3142 | treated differently depending on something about the variable or\n\ |
3143 | function named by the symbol (such as what section it is in).\n\ |
3144 | \n\ |
3145 | The hook is executed immediately after rtl has been created for\n\ |
3146 | @var{decl}, which may be a variable or function declaration or\n\ |
3147 | an entry in the constant pool. In either case, @var{rtl} is the\n\ |
3148 | rtl in question. Do @emph{not} use @code{DECL_RTL (@var{decl})}\n\ |
3149 | in this hook; that field may not have been initialized yet.\n\ |
3150 | \n\ |
3151 | In the case of a constant, it is safe to assume that the rtl is\n\ |
3152 | a @code{mem} whose address is a @code{symbol_ref}. Most decls\n\ |
3153 | will also have this form, but that is not guaranteed. Global\n\ |
3154 | register variables, for instance, will have a @code{reg} for their\n\ |
3155 | rtl. (Normally the right thing to do with such unusual rtl is\n\ |
3156 | leave it alone.)\n\ |
3157 | \n\ |
3158 | The @var{new_decl_p} argument will be true if this is the first time\n\ |
3159 | that @code{TARGET_ENCODE_SECTION_INFO} has been invoked on this decl. It will\n\ |
3160 | be false for subsequent invocations, which will happen for duplicate\n\ |
3161 | declarations. Whether or not anything must be done for the duplicate\n\ |
3162 | declaration depends on whether the hook examines @code{DECL_ATTRIBUTES}.\n\ |
3163 | @var{new_decl_p} is always true when the hook is called for a constant.\n\ |
3164 | \n\ |
3165 | @cindex @code{SYMBOL_REF_FLAG}, in @code{TARGET_ENCODE_SECTION_INFO}\n\ |
3166 | The usual thing for this hook to do is to record flags in the\n\ |
3167 | @code{symbol_ref}, using @code{SYMBOL_REF_FLAG} or @code{SYMBOL_REF_FLAGS}.\n\ |
3168 | Historically, the name string was modified if it was necessary to\n\ |
3169 | encode more than one bit of information, but this practice is now\n\ |
3170 | discouraged; use @code{SYMBOL_REF_FLAGS}.\n\ |
3171 | \n\ |
3172 | The default definition of this hook, @code{default_encode_section_info}\n\ |
3173 | in @file{varasm.cc}, sets a number of commonly-useful bits in\n\ |
3174 | @code{SYMBOL_REF_FLAGS}. Check whether the default does what you need\n\ |
3175 | before overriding it." , |
3176 | void, (tree decl, rtx rtl, int new_decl_p), |
3177 | default_encode_section_info) |
3178 | |
3179 | /* Undo the effects of encode_section_info on the symbol string. */ |
3180 | DEFHOOK |
3181 | (strip_name_encoding, |
3182 | "Decode @var{name} and return the real name part, sans\n\ |
3183 | the characters that @code{TARGET_ENCODE_SECTION_INFO}\n\ |
3184 | may have added." , |
3185 | const char *, (const char *name), |
3186 | default_strip_name_encoding) |
3187 | |
3188 | /* If shift optabs for MODE are known to always truncate the shift count, |
3189 | return the mask that they apply. Return 0 otherwise. */ |
3190 | DEFHOOK |
3191 | (shift_truncation_mask, |
3192 | "This function describes how the standard shift patterns for @var{mode}\n\ |
3193 | deal with shifts by negative amounts or by more than the width of the mode.\n\ |
3194 | @xref{shift patterns}.\n\ |
3195 | \n\ |
3196 | On many machines, the shift patterns will apply a mask @var{m} to the\n\ |
3197 | shift count, meaning that a fixed-width shift of @var{x} by @var{y} is\n\ |
3198 | equivalent to an arbitrary-width shift of @var{x} by @var{y & m}. If\n\ |
3199 | this is true for mode @var{mode}, the function should return @var{m},\n\ |
3200 | otherwise it should return 0. A return value of 0 indicates that no\n\ |
3201 | particular behavior is guaranteed.\n\ |
3202 | \n\ |
3203 | Note that, unlike @code{SHIFT_COUNT_TRUNCATED}, this function does\n\ |
3204 | @emph{not} apply to general shift rtxes; it applies only to instructions\n\ |
3205 | that are generated by the named shift patterns.\n\ |
3206 | \n\ |
3207 | The default implementation of this function returns\n\ |
3208 | @code{GET_MODE_BITSIZE (@var{mode}) - 1} if @code{SHIFT_COUNT_TRUNCATED}\n\ |
3209 | and 0 otherwise. This definition is always safe, but if\n\ |
3210 | @code{SHIFT_COUNT_TRUNCATED} is false, and some shift patterns\n\ |
3211 | nevertheless truncate the shift count, you may get better code\n\ |
3212 | by overriding it." , |
3213 | unsigned HOST_WIDE_INT, (machine_mode mode), |
3214 | default_shift_truncation_mask) |
3215 | |
3216 | /* Return the number of divisions in the given MODE that should be present, |
3217 | so that it is profitable to turn the division into a multiplication by |
3218 | the reciprocal. */ |
3219 | DEFHOOK |
3220 | (min_divisions_for_recip_mul, |
3221 | "When @option{-ffast-math} is in effect, GCC tries to optimize\n\ |
3222 | divisions by the same divisor, by turning them into multiplications by\n\ |
3223 | the reciprocal. This target hook specifies the minimum number of divisions\n\ |
3224 | that should be there for GCC to perform the optimization for a variable\n\ |
3225 | of mode @var{mode}. The default implementation returns 3 if the machine\n\ |
3226 | has an instruction for the division, and 2 if it does not." , |
3227 | unsigned int, (machine_mode mode), |
3228 | default_min_divisions_for_recip_mul) |
3229 | |
3230 | DEFHOOK |
3231 | (truly_noop_truncation, |
3232 | "This hook returns true if it is safe to ``convert'' a value of\n\ |
3233 | @var{inprec} bits to one of @var{outprec} bits (where @var{outprec} is\n\ |
3234 | smaller than @var{inprec}) by merely operating on it as if it had only\n\ |
3235 | @var{outprec} bits. The default returns true unconditionally, which\n\ |
3236 | is correct for most machines. When @code{TARGET_TRULY_NOOP_TRUNCATION}\n\ |
3237 | returns false, the machine description should provide a @code{trunc}\n\ |
3238 | optab to specify the RTL that performs the required truncation.\n\ |
3239 | \n\ |
3240 | If @code{TARGET_MODES_TIEABLE_P} returns false for a pair of modes,\n\ |
3241 | suboptimal code can result if this hook returns true for the corresponding\n\ |
3242 | mode sizes. Making this hook return false in such cases may improve things." , |
3243 | bool, (poly_uint64 outprec, poly_uint64 inprec), |
3244 | hook_bool_puint64_puint64_true) |
3245 | |
3246 | /* If the representation of integral MODE is such that values are |
3247 | always sign-extended to a wider mode MODE_REP then return |
3248 | SIGN_EXTEND. Return UNKNOWN otherwise. */ |
3249 | /* Note that the return type ought to be RTX_CODE, but that's not |
3250 | necessarily defined at this point. */ |
3251 | DEFHOOK |
3252 | (mode_rep_extended, |
3253 | "The representation of an integral mode can be such that the values\n\ |
3254 | are always extended to a wider integral mode. Return\n\ |
3255 | @code{SIGN_EXTEND} if values of @var{mode} are represented in\n\ |
3256 | sign-extended form to @var{rep_mode}. Return @code{UNKNOWN}\n\ |
3257 | otherwise. (Currently, none of the targets use zero-extended\n\ |
3258 | representation this way so unlike @code{LOAD_EXTEND_OP},\n\ |
3259 | @code{TARGET_MODE_REP_EXTENDED} is expected to return either\n\ |
3260 | @code{SIGN_EXTEND} or @code{UNKNOWN}. Also no target extends\n\ |
3261 | @var{mode} to @var{rep_mode} so that @var{rep_mode} is not the next\n\ |
3262 | widest integral mode and currently we take advantage of this fact.)\n\ |
3263 | \n\ |
3264 | Similarly to @code{LOAD_EXTEND_OP} you may return a non-@code{UNKNOWN}\n\ |
3265 | value even if the extension is not performed on certain hard registers\n\ |
3266 | as long as for the @code{REGNO_REG_CLASS} of these hard registers\n\ |
3267 | @code{TARGET_CAN_CHANGE_MODE_CLASS} returns false.\n\ |
3268 | \n\ |
3269 | Note that @code{TARGET_MODE_REP_EXTENDED} and @code{LOAD_EXTEND_OP}\n\ |
3270 | describe two related properties. If you define\n\ |
3271 | @code{TARGET_MODE_REP_EXTENDED (mode, word_mode)} you probably also want\n\ |
3272 | to define @code{LOAD_EXTEND_OP (mode)} to return the same type of\n\ |
3273 | extension.\n\ |
3274 | \n\ |
3275 | In order to enforce the representation of @code{mode},\n\ |
3276 | @code{TARGET_TRULY_NOOP_TRUNCATION} should return false when truncating to\n\ |
3277 | @code{mode}." , |
3278 | int, (scalar_int_mode mode, scalar_int_mode rep_mode), |
3279 | default_mode_rep_extended) |
3280 | |
3281 | DEFHOOK |
3282 | (setjmp_preserves_nonvolatile_regs_p, |
3283 | "On some targets, it is assumed that the compiler will spill all pseudos\n\ |
3284 | that are live across a call to @code{setjmp}, while other targets treat\n\ |
3285 | @code{setjmp} calls as normal function calls.\n\ |
3286 | \n\ |
3287 | This hook returns false if @code{setjmp} calls do not preserve all\n\ |
3288 | non-volatile registers so that gcc that must spill all pseudos that are\n\ |
3289 | live across @code{setjmp} calls. Define this to return true if the\n\ |
3290 | target does not need to spill all pseudos live across @code{setjmp} calls.\n\ |
3291 | The default implementation conservatively assumes all pseudos must be\n\ |
3292 | spilled across @code{setjmp} calls." , |
3293 | bool, (void), |
3294 | hook_bool_void_false) |
3295 | |
3296 | /* True if MODE is valid for a pointer in __attribute__((mode("MODE"))). */ |
3297 | DEFHOOK |
3298 | (valid_pointer_mode, |
3299 | "Define this to return nonzero if the port can handle pointers\n\ |
3300 | with machine mode @var{mode}. The default version of this\n\ |
3301 | hook returns true for both @code{ptr_mode} and @code{Pmode}." , |
3302 | bool, (scalar_int_mode mode), |
3303 | default_valid_pointer_mode) |
3304 | |
3305 | /* Disambiguate with errno. */ |
3306 | DEFHOOK |
3307 | (ref_may_alias_errno, |
3308 | "Define this to return nonzero if the memory reference @var{ref}\n\ |
3309 | may alias with the system C library errno location. The default\n\ |
3310 | version of this hook assumes the system C library errno location\n\ |
3311 | is either a declaration of type int or accessed by dereferencing\n\ |
3312 | a pointer to int." , |
3313 | bool, (ao_ref *ref), |
3314 | default_ref_may_alias_errno) |
3315 | |
3316 | /* Support for named address spaces. */ |
3317 | #undef HOOK_PREFIX |
3318 | #define HOOK_PREFIX "TARGET_ADDR_SPACE_" |
3319 | HOOK_VECTOR (TARGET_ADDR_SPACE_HOOKS, addr_space) |
3320 | |
3321 | /* MODE to use for a pointer into another address space. */ |
3322 | DEFHOOK |
3323 | (pointer_mode, |
3324 | "Define this to return the machine mode to use for pointers to\n\ |
3325 | @var{address_space} if the target supports named address spaces.\n\ |
3326 | The default version of this hook returns @code{ptr_mode}." , |
3327 | scalar_int_mode, (addr_space_t address_space), |
3328 | default_addr_space_pointer_mode) |
3329 | |
3330 | /* MODE to use for an address in another address space. */ |
3331 | DEFHOOK |
3332 | (address_mode, |
3333 | "Define this to return the machine mode to use for addresses in\n\ |
3334 | @var{address_space} if the target supports named address spaces.\n\ |
3335 | The default version of this hook returns @code{Pmode}." , |
3336 | scalar_int_mode, (addr_space_t address_space), |
3337 | default_addr_space_address_mode) |
3338 | |
3339 | /* True if MODE is valid for a pointer in __attribute__((mode("MODE"))) |
3340 | in another address space. */ |
3341 | DEFHOOK |
3342 | (valid_pointer_mode, |
3343 | "Define this to return nonzero if the port can handle pointers\n\ |
3344 | with machine mode @var{mode} to address space @var{as}. This target\n\ |
3345 | hook is the same as the @code{TARGET_VALID_POINTER_MODE} target hook,\n\ |
3346 | except that it includes explicit named address space support. The default\n\ |
3347 | version of this hook returns true for the modes returned by either the\n\ |
3348 | @code{TARGET_ADDR_SPACE_POINTER_MODE} or @code{TARGET_ADDR_SPACE_ADDRESS_MODE}\n\ |
3349 | target hooks for the given address space." , |
3350 | bool, (scalar_int_mode mode, addr_space_t as), |
3351 | default_addr_space_valid_pointer_mode) |
3352 | |
3353 | /* True if an address is a valid memory address to a given named address |
3354 | space for a given mode. */ |
3355 | DEFHOOK |
3356 | (legitimate_address_p, |
3357 | "Define this to return true if @var{exp} is a valid address for mode\n\ |
3358 | @var{mode} in the named address space @var{as} with the use context\n\ |
3359 | @var{ch}. The @var{strict} parameter says whether strict addressing\n\ |
3360 | is in effect after reload has finished. The @var{ch} indicates what\n\ |
3361 | context @var{exp} will be used for. This target hook is the same as the\n\ |
3362 | @code{TARGET_LEGITIMATE_ADDRESS_P} target hook, except that it includes\n\ |
3363 | explicit named address space support." , |
3364 | bool, (machine_mode mode, rtx exp, bool strict, addr_space_t as, code_helper ch), |
3365 | default_addr_space_legitimate_address_p) |
3366 | |
3367 | /* Return an updated address to convert an invalid pointer to a named |
3368 | address space to a valid one. If NULL_RTX is returned use machine |
3369 | independent methods to make the address valid. */ |
3370 | DEFHOOK |
3371 | (legitimize_address, |
3372 | "Define this to modify an invalid address @var{x} to be a valid address\n\ |
3373 | with mode @var{mode} in the named address space @var{as}. This target\n\ |
3374 | hook is the same as the @code{TARGET_LEGITIMIZE_ADDRESS} target hook,\n\ |
3375 | except that it includes explicit named address space support." , |
3376 | rtx, (rtx x, rtx oldx, machine_mode mode, addr_space_t as), |
3377 | default_addr_space_legitimize_address) |
3378 | |
3379 | /* True if one named address space is a subset of another named address. */ |
3380 | DEFHOOK |
3381 | (subset_p, |
3382 | "Define this to return whether the @var{subset} named address space is\n\ |
3383 | contained within the @var{superset} named address space. Pointers to\n\ |
3384 | a named address space that is a subset of another named address space\n\ |
3385 | will be converted automatically without a cast if used together in\n\ |
3386 | arithmetic operations. Pointers to a superset address space can be\n\ |
3387 | converted to pointers to a subset address space via explicit casts." , |
3388 | bool, (addr_space_t subset, addr_space_t superset), |
3389 | default_addr_space_subset_p) |
3390 | |
3391 | /* True if 0 is a valid address in the address space, or false if |
3392 | 0 is a NULL in the address space. */ |
3393 | DEFHOOK |
3394 | (zero_address_valid, |
3395 | "Define this to modify the default handling of address 0 for the\n\ |
3396 | address space. Return true if 0 should be considered a valid address." , |
3397 | bool, (addr_space_t as), |
3398 | default_addr_space_zero_address_valid) |
3399 | |
3400 | /* Function to convert an rtl expression from one address space to another. */ |
3401 | DEFHOOK |
3402 | (convert, |
3403 | "Define this to convert the pointer expression represented by the RTL\n\ |
3404 | @var{op} with type @var{from_type} that points to a named address\n\ |
3405 | space to a new pointer expression with type @var{to_type} that points\n\ |
3406 | to a different named address space. When this hook it called, it is\n\ |
3407 | guaranteed that one of the two address spaces is a subset of the other,\n\ |
3408 | as determined by the @code{TARGET_ADDR_SPACE_SUBSET_P} target hook." , |
3409 | rtx, (rtx op, tree from_type, tree to_type), |
3410 | default_addr_space_convert) |
3411 | |
3412 | /* Function to encode an address space into dwarf. */ |
3413 | DEFHOOK |
3414 | (debug, |
3415 | "Define this to define how the address space is encoded in dwarf.\n\ |
3416 | The result is the value to be used with @code{DW_AT_address_class}." , |
3417 | int, (addr_space_t as), |
3418 | default_addr_space_debug) |
3419 | |
3420 | /* Function to emit custom diagnostic if an address space is used. */ |
3421 | DEFHOOK |
3422 | (diagnose_usage, |
3423 | "Define this hook if the availability of an address space depends on\n\ |
3424 | command line options and some diagnostics should be printed when the\n\ |
3425 | address space is used. This hook is called during parsing and allows\n\ |
3426 | to emit a better diagnostic compared to the case where the address space\n\ |
3427 | was not registered with @code{c_register_addr_space}. @var{as} is\n\ |
3428 | the address space as registered with @code{c_register_addr_space}.\n\ |
3429 | @var{loc} is the location of the address space qualifier token.\n\ |
3430 | The default implementation does nothing." , |
3431 | void, (addr_space_t as, location_t loc), |
3432 | default_addr_space_diagnose_usage) |
3433 | |
3434 | HOOK_VECTOR_END (addr_space) |
3435 | |
3436 | #undef HOOK_PREFIX |
3437 | #define HOOK_PREFIX "TARGET_" |
3438 | |
3439 | DEFHOOK |
3440 | (lower_local_decl_alignment, |
3441 | "Define this hook to lower alignment of local, parm or result\n\ |
3442 | decl @samp{(@var{decl})}." , |
3443 | void, (tree decl), |
3444 | hook_void_tree) |
3445 | |
3446 | DEFHOOK |
3447 | (static_rtx_alignment, |
3448 | "This hook returns the preferred alignment in bits for a\n\ |
3449 | statically-allocated rtx, such as a constant pool entry. @var{mode}\n\ |
3450 | is the mode of the rtx. The default implementation returns\n\ |
3451 | @samp{GET_MODE_ALIGNMENT (@var{mode})}." , |
3452 | HOST_WIDE_INT, (machine_mode mode), |
3453 | default_static_rtx_alignment) |
3454 | |
3455 | DEFHOOK |
3456 | (constant_alignment, |
3457 | "This hook returns the alignment in bits of a constant that is being\n\ |
3458 | placed in memory. @var{constant} is the constant and @var{basic_align}\n\ |
3459 | is the alignment that the object would ordinarily have.\n\ |
3460 | \n\ |
3461 | The default definition just returns @var{basic_align}.\n\ |
3462 | \n\ |
3463 | The typical use of this hook is to increase alignment for string\n\ |
3464 | constants to be word aligned so that @code{strcpy} calls that copy\n\ |
3465 | constants can be done inline. The function\n\ |
3466 | @code{constant_alignment_word_strings} provides such a definition." , |
3467 | HOST_WIDE_INT, (const_tree constant, HOST_WIDE_INT basic_align), |
3468 | default_constant_alignment) |
3469 | |
3470 | DEFHOOK |
3471 | (translate_mode_attribute, |
3472 | "Define this hook if during mode attribute processing, the port should\n\ |
3473 | translate machine_mode @var{mode} to another mode. For example, rs6000's\n\ |
3474 | @code{KFmode}, when it is the same as @code{TFmode}.\n\ |
3475 | \n\ |
3476 | The default version of the hook returns that mode that was passed in." , |
3477 | machine_mode, (machine_mode mode), |
3478 | default_translate_mode_attribute) |
3479 | |
3480 | /* True if MODE is valid for the target. By "valid", we mean able to |
3481 | be manipulated in non-trivial ways. In particular, this means all |
3482 | the arithmetic is supported. */ |
3483 | DEFHOOK |
3484 | (scalar_mode_supported_p, |
3485 | "Define this to return nonzero if the port is prepared to handle\n\ |
3486 | insns involving scalar mode @var{mode}. For a scalar mode to be\n\ |
3487 | considered supported, all the basic arithmetic and comparisons\n\ |
3488 | must work.\n\ |
3489 | \n\ |
3490 | The default version of this hook returns true for any mode\n\ |
3491 | required to handle the basic C types (as defined by the port).\n\ |
3492 | Included here are the double-word arithmetic supported by the\n\ |
3493 | code in @file{optabs.cc}." , |
3494 | bool, (scalar_mode mode), |
3495 | default_scalar_mode_supported_p) |
3496 | |
3497 | /* Similarly for vector modes. "Supported" here is less strict. At |
3498 | least some operations are supported; need to check optabs or builtins |
3499 | for further details. */ |
3500 | DEFHOOK |
3501 | (vector_mode_supported_p, |
3502 | "Define this to return nonzero if the current target is prepared to handle\n\ |
3503 | insns involving vector mode @var{mode}. At the very least, it\n\ |
3504 | must have move patterns for this mode." , |
3505 | bool, (machine_mode mode), |
3506 | hook_bool_mode_false) |
3507 | |
3508 | DEFHOOK |
3509 | (vector_mode_supported_any_target_p, |
3510 | "Define this to return nonzero if the port is prepared to handle\n\ |
3511 | insns involving vector mode @var{mode} in any target configuration.\n\ |
3512 | Returning @var{true} means that the mode can be used as the @samp{TYPE_MODE}\n\ |
3513 | for vector types.\n\ |
3514 | \n\ |
3515 | The default version of this hook returns true. The final mode assigned to\n\ |
3516 | @samp{TYPE_MODE} will also be checked against\n\ |
3517 | @code{TARGET_VECTOR_MODE_SUPPORTED_P} to take target configuration into\n\ |
3518 | account." , |
3519 | bool, (machine_mode mode), |
3520 | hook_bool_mode_true) |
3521 | |
3522 | DEFHOOK |
3523 | (compatible_vector_types_p, |
3524 | "Return true if there is no target-specific reason for treating\n\ |
3525 | vector types @var{type1} and @var{type2} as distinct types. The caller\n\ |
3526 | has already checked for target-independent reasons, meaning that the\n\ |
3527 | types are known to have the same mode, to have the same number of elements,\n\ |
3528 | and to have what the caller considers to be compatible element types.\n\ |
3529 | \n\ |
3530 | The main reason for defining this hook is to reject pairs of types\n\ |
3531 | that are handled differently by the target's calling convention.\n\ |
3532 | For example, when a new @var{N}-bit vector architecture is added\n\ |
3533 | to a target, the target may want to handle normal @var{N}-bit\n\ |
3534 | @code{VECTOR_TYPE} arguments and return values in the same way as\n\ |
3535 | before, to maintain backwards compatibility. However, it may also\n\ |
3536 | provide new, architecture-specific @code{VECTOR_TYPE}s that are passed\n\ |
3537 | and returned in a more efficient way. It is then important to maintain\n\ |
3538 | a distinction between the ``normal'' @code{VECTOR_TYPE}s and the new\n\ |
3539 | architecture-specific ones.\n\ |
3540 | \n\ |
3541 | The default implementation returns true, which is correct for most targets." , |
3542 | bool, (const_tree type1, const_tree type2), |
3543 | hook_bool_const_tree_const_tree_true) |
3544 | |
3545 | DEFHOOK |
3546 | (vector_alignment, |
3547 | "This hook can be used to define the alignment for a vector of type\n\ |
3548 | @var{type}, in order to comply with a platform ABI. The default is to\n\ |
3549 | require natural alignment for vector types. The alignment returned by\n\ |
3550 | this hook must be a power-of-two multiple of the default alignment of\n\ |
3551 | the vector element type." , |
3552 | HOST_WIDE_INT, (const_tree type), |
3553 | default_vector_alignment) |
3554 | |
3555 | DEFHOOK |
3556 | (array_mode, |
3557 | "Return the mode that GCC should use for an array that has\n\ |
3558 | @var{nelems} elements, with each element having mode @var{mode}.\n\ |
3559 | Return no mode if the target has no special requirements. In the\n\ |
3560 | latter case, GCC looks for an integer mode of the appropriate size\n\ |
3561 | if available and uses BLKmode otherwise. Usually the search for the\n\ |
3562 | integer mode is limited to @code{MAX_FIXED_MODE_SIZE}, but the\n\ |
3563 | @code{TARGET_ARRAY_MODE_SUPPORTED_P} hook allows a larger mode to be\n\ |
3564 | used in specific cases.\n\ |
3565 | \n\ |
3566 | The main use of this hook is to specify that an array of vectors should\n\ |
3567 | also have a vector mode. The default implementation returns no mode." , |
3568 | opt_machine_mode, (machine_mode mode, unsigned HOST_WIDE_INT nelems), |
3569 | hook_optmode_mode_uhwi_none) |
3570 | |
3571 | /* True if we should try to use a scalar mode to represent an array, |
3572 | overriding the usual MAX_FIXED_MODE limit. */ |
3573 | DEFHOOK |
3574 | (array_mode_supported_p, |
3575 | "Return true if GCC should try to use a scalar mode to store an array\n\ |
3576 | of @var{nelems} elements, given that each element has mode @var{mode}.\n\ |
3577 | Returning true here overrides the usual @code{MAX_FIXED_MODE} limit\n\ |
3578 | and allows GCC to use any defined integer mode.\n\ |
3579 | \n\ |
3580 | One use of this hook is to support vector load and store operations\n\ |
3581 | that operate on several homogeneous vectors. For example, ARM NEON\n\ |
3582 | has operations like:\n\ |
3583 | \n\ |
3584 | @smallexample\n\ |
3585 | int8x8x3_t vld3_s8 (const int8_t *)\n\ |
3586 | @end smallexample\n\ |
3587 | \n\ |
3588 | where the return type is defined as:\n\ |
3589 | \n\ |
3590 | @smallexample\n\ |
3591 | typedef struct int8x8x3_t\n\ |
3592 | @{\n\ |
3593 | int8x8_t val[3];\n\ |
3594 | @} int8x8x3_t;\n\ |
3595 | @end smallexample\n\ |
3596 | \n\ |
3597 | If this hook allows @code{val} to have a scalar mode, then\n\ |
3598 | @code{int8x8x3_t} can have the same mode. GCC can then store\n\ |
3599 | @code{int8x8x3_t}s in registers rather than forcing them onto the stack." , |
3600 | bool, (machine_mode mode, unsigned HOST_WIDE_INT nelems), |
3601 | hook_bool_mode_uhwi_false) |
3602 | |
3603 | DEFHOOK |
3604 | (libgcc_floating_mode_supported_p, |
3605 | "Define this to return nonzero if libgcc provides support for the \n\ |
3606 | floating-point mode @var{mode}, which is known to pass \n\ |
3607 | @code{TARGET_SCALAR_MODE_SUPPORTED_P}. The default version of this \n\ |
3608 | hook returns true for all of @code{SFmode}, @code{DFmode}, \n\ |
3609 | @code{XFmode} and @code{TFmode}, if such modes exist." , |
3610 | bool, (scalar_float_mode mode), |
3611 | default_libgcc_floating_mode_supported_p) |
3612 | |
3613 | DEFHOOK |
3614 | (floatn_mode, |
3615 | "Define this to return the machine mode to use for the type \n\ |
3616 | @code{_Float@var{n}}, if @var{extended} is false, or the type \n\ |
3617 | @code{_Float@var{n}x}, if @var{extended} is true. If such a type is not\n\ |
3618 | supported, return @code{opt_scalar_float_mode ()}. The default version of\n\ |
3619 | this hook returns @code{SFmode} for @code{_Float32}, @code{DFmode} for\n\ |
3620 | @code{_Float64} and @code{_Float32x} and @code{TFmode} for \n\ |
3621 | @code{_Float128}, if those modes exist and satisfy the requirements for \n\ |
3622 | those types and pass @code{TARGET_SCALAR_MODE_SUPPORTED_P} and \n\ |
3623 | @code{TARGET_LIBGCC_FLOATING_MODE_SUPPORTED_P}; for @code{_Float64x}, it \n\ |
3624 | returns the first of @code{XFmode} and @code{TFmode} that exists and \n\ |
3625 | satisfies the same requirements; for other types, it returns \n\ |
3626 | @code{opt_scalar_float_mode ()}. The hook is only called for values\n\ |
3627 | of @var{n} and @var{extended} that are valid according to\n\ |
3628 | ISO/IEC TS 18661-3:2015; that is, @var{n} is one of 32, 64, 128, or,\n\ |
3629 | if @var{extended} is false, 16 or greater than 128 and a multiple of 32." , |
3630 | opt_scalar_float_mode, (int n, bool extended), |
3631 | default_floatn_mode) |
3632 | |
3633 | DEFHOOK |
3634 | (floatn_builtin_p, |
3635 | "Define this to return true if the @code{_Float@var{n}} and\n\ |
3636 | @code{_Float@var{n}x} built-in functions should implicitly enable the\n\ |
3637 | built-in function without the @code{__builtin_} prefix in addition to the\n\ |
3638 | normal built-in function with the @code{__builtin_} prefix. The default is\n\ |
3639 | to only enable built-in functions without the @code{__builtin_} prefix for\n\ |
3640 | the GNU C langauge. In strict ANSI/ISO mode, the built-in function without\n\ |
3641 | the @code{__builtin_} prefix is not enabled. The argument @code{FUNC} is the\n\ |
3642 | @code{enum built_in_function} id of the function to be enabled." , |
3643 | bool, (int func), |
3644 | default_floatn_builtin_p) |
3645 | |
3646 | /* Compute cost of moving data from a register of class FROM to one of |
3647 | TO, using MODE. */ |
3648 | DEFHOOK |
3649 | (register_move_cost, |
3650 | "This target hook should return the cost of moving data of mode @var{mode}\n\ |
3651 | from a register in class @var{from} to one in class @var{to}. The classes\n\ |
3652 | are expressed using the enumeration values such as @code{GENERAL_REGS}.\n\ |
3653 | A value of 2 is the default; other values are interpreted relative to\n\ |
3654 | that.\n\ |
3655 | \n\ |
3656 | It is not required that the cost always equal 2 when @var{from} is the\n\ |
3657 | same as @var{to}; on some machines it is expensive to move between\n\ |
3658 | registers if they are not general registers.\n\ |
3659 | \n\ |
3660 | If reload sees an insn consisting of a single @code{set} between two\n\ |
3661 | hard registers, and if @code{TARGET_REGISTER_MOVE_COST} applied to their\n\ |
3662 | classes returns a value of 2, reload does not check to ensure that the\n\ |
3663 | constraints of the insn are met. Setting a cost of other than 2 will\n\ |
3664 | allow reload to verify that the constraints are met. You should do this\n\ |
3665 | if the @samp{mov@var{m}} pattern's constraints do not allow such copying.\n\ |
3666 | \n\ |
3667 | The default version of this function returns 2." , |
3668 | int, (machine_mode mode, reg_class_t from, reg_class_t to), |
3669 | default_register_move_cost) |
3670 | |
3671 | /* Compute cost of moving registers to/from memory. */ |
3672 | /* ??? Documenting the argument types for this hook requires a GFDL |
3673 | license grant. Also, the documentation uses a different name for RCLASS. */ |
3674 | DEFHOOK |
3675 | (memory_move_cost, |
3676 | "This target hook should return the cost of moving data of mode @var{mode}\n\ |
3677 | between a register of class @var{rclass} and memory; @var{in} is @code{false}\n\ |
3678 | if the value is to be written to memory, @code{true} if it is to be read in.\n\ |
3679 | This cost is relative to those in @code{TARGET_REGISTER_MOVE_COST}.\n\ |
3680 | If moving between registers and memory is more expensive than between two\n\ |
3681 | registers, you should add this target hook to express the relative cost.\n\ |
3682 | \n\ |
3683 | If you do not add this target hook, GCC uses a default cost of 4 plus\n\ |
3684 | the cost of copying via a secondary reload register, if one is\n\ |
3685 | needed. If your machine requires a secondary reload register to copy\n\ |
3686 | between memory and a register of @var{rclass} but the reload mechanism is\n\ |
3687 | more complex than copying via an intermediate, use this target hook to\n\ |
3688 | reflect the actual cost of the move.\n\ |
3689 | \n\ |
3690 | GCC defines the function @code{memory_move_secondary_cost} if\n\ |
3691 | secondary reloads are needed. It computes the costs due to copying via\n\ |
3692 | a secondary register. If your machine copies from memory using a\n\ |
3693 | secondary register in the conventional way but the default base value of\n\ |
3694 | 4 is not correct for your machine, use this target hook to add some other\n\ |
3695 | value to the result of that function. The arguments to that function\n\ |
3696 | are the same as to this target hook." , |
3697 | int, (machine_mode mode, reg_class_t rclass, bool in), |
3698 | default_memory_move_cost) |
3699 | |
3700 | DEFHOOK |
3701 | (use_by_pieces_infrastructure_p, |
3702 | "GCC will attempt several strategies when asked to copy between\n\ |
3703 | two areas of memory, or to set, clear or store to memory, for example\n\ |
3704 | when copying a @code{struct}. The @code{by_pieces} infrastructure\n\ |
3705 | implements such memory operations as a sequence of load, store or move\n\ |
3706 | insns. Alternate strategies are to expand the\n\ |
3707 | @code{cpymem} or @code{setmem} optabs, to emit a library call, or to emit\n\ |
3708 | unit-by-unit, loop-based operations.\n\ |
3709 | \n\ |
3710 | This target hook should return true if, for a memory operation with a\n\ |
3711 | given @var{size} and @var{alignment}, using the @code{by_pieces}\n\ |
3712 | infrastructure is expected to result in better code generation.\n\ |
3713 | Both @var{size} and @var{alignment} are measured in terms of storage\n\ |
3714 | units.\n\ |
3715 | \n\ |
3716 | The parameter @var{op} is one of: @code{CLEAR_BY_PIECES},\n\ |
3717 | @code{MOVE_BY_PIECES}, @code{SET_BY_PIECES}, @code{STORE_BY_PIECES} or\n\ |
3718 | @code{COMPARE_BY_PIECES}. These describe the type of memory operation\n\ |
3719 | under consideration.\n\ |
3720 | \n\ |
3721 | The parameter @var{speed_p} is true if the code is currently being\n\ |
3722 | optimized for speed rather than size.\n\ |
3723 | \n\ |
3724 | Returning true for higher values of @var{size} can improve code generation\n\ |
3725 | for speed if the target does not provide an implementation of the\n\ |
3726 | @code{cpymem} or @code{setmem} standard names, if the @code{cpymem} or\n\ |
3727 | @code{setmem} implementation would be more expensive than a sequence of\n\ |
3728 | insns, or if the overhead of a library call would dominate that of\n\ |
3729 | the body of the memory operation.\n\ |
3730 | \n\ |
3731 | Returning true for higher values of @code{size} may also cause an increase\n\ |
3732 | in code size, for example where the number of insns emitted to perform a\n\ |
3733 | move would be greater than that of a library call." , |
3734 | bool, (unsigned HOST_WIDE_INT size, unsigned int alignment, |
3735 | enum by_pieces_operation op, bool speed_p), |
3736 | default_use_by_pieces_infrastructure_p) |
3737 | |
3738 | DEFHOOK |
3739 | (overlap_op_by_pieces_p, |
3740 | "This target hook should return true if when the @code{by_pieces}\n\ |
3741 | infrastructure is used, an offset adjusted unaligned memory operation\n\ |
3742 | in the smallest integer mode for the last piece operation of a memory\n\ |
3743 | region can be generated to avoid doing more than one smaller operations." , |
3744 | bool, (void), |
3745 | hook_bool_void_false) |
3746 | |
3747 | DEFHOOK |
3748 | (compare_by_pieces_branch_ratio, |
3749 | "When expanding a block comparison in MODE, gcc can try to reduce the\n\ |
3750 | number of branches at the expense of more memory operations. This hook\n\ |
3751 | allows the target to override the default choice. It should return the\n\ |
3752 | factor by which branches should be reduced over the plain expansion with\n\ |
3753 | one comparison per @var{mode}-sized piece. A port can also prevent a\n\ |
3754 | particular mode from being used for block comparisons by returning a\n\ |
3755 | negative number from this hook." , |
3756 | int, (machine_mode mode), |
3757 | default_compare_by_pieces_branch_ratio) |
3758 | |
3759 | DEFHOOK |
3760 | (slow_unaligned_access, |
3761 | "This hook returns true if memory accesses described by the\n\ |
3762 | @var{mode} and @var{alignment} parameters have a cost many times greater\n\ |
3763 | than aligned accesses, for example if they are emulated in a trap handler.\n\ |
3764 | This hook is invoked only for unaligned accesses, i.e.@: when\n\ |
3765 | @code{@var{alignment} < GET_MODE_ALIGNMENT (@var{mode})}.\n\ |
3766 | \n\ |
3767 | When this hook returns true, the compiler will act as if\n\ |
3768 | @code{STRICT_ALIGNMENT} were true when generating code for block\n\ |
3769 | moves. This can cause significantly more instructions to be produced.\n\ |
3770 | Therefore, do not make this hook return true if unaligned accesses only\n\ |
3771 | add a cycle or two to the time for a memory access.\n\ |
3772 | \n\ |
3773 | The hook must return true whenever @code{STRICT_ALIGNMENT} is true.\n\ |
3774 | The default implementation returns @code{STRICT_ALIGNMENT}." , |
3775 | bool, (machine_mode mode, unsigned int align), |
3776 | default_slow_unaligned_access) |
3777 | |
3778 | DEFHOOK |
3779 | (optab_supported_p, |
3780 | "Return true if the optimizers should use optab @var{op} with\n\ |
3781 | modes @var{mode1} and @var{mode2} for optimization type @var{opt_type}.\n\ |
3782 | The optab is known to have an associated @file{.md} instruction\n\ |
3783 | whose C condition is true. @var{mode2} is only meaningful for conversion\n\ |
3784 | optabs; for direct optabs it is a copy of @var{mode1}.\n\ |
3785 | \n\ |
3786 | For example, when called with @var{op} equal to @code{rint_optab} and\n\ |
3787 | @var{mode1} equal to @code{DFmode}, the hook should say whether the\n\ |
3788 | optimizers should use optab @code{rintdf2}.\n\ |
3789 | \n\ |
3790 | The default hook returns true for all inputs." , |
3791 | bool, (int op, machine_mode mode1, machine_mode mode2, |
3792 | optimization_type opt_type), |
3793 | default_optab_supported_p) |
3794 | |
3795 | /* True for MODE if the target expects that registers in this mode will |
3796 | be allocated to registers in a small register class. The compiler is |
3797 | allowed to use registers explicitly used in the rtl as spill registers |
3798 | but it should prevent extending the lifetime of these registers. */ |
3799 | DEFHOOK |
3800 | (small_register_classes_for_mode_p, |
3801 | "Define this to return nonzero for machine modes for which the port has\n\ |
3802 | small register classes. If this target hook returns nonzero for a given\n\ |
3803 | @var{mode}, the compiler will try to minimize the lifetime of registers\n\ |
3804 | in @var{mode}. The hook may be called with @code{VOIDmode} as argument.\n\ |
3805 | In this case, the hook is expected to return nonzero if it returns nonzero\n\ |
3806 | for any mode.\n\ |
3807 | \n\ |
3808 | On some machines, it is risky to let hard registers live across arbitrary\n\ |
3809 | insns. Typically, these machines have instructions that require values\n\ |
3810 | to be in specific registers (like an accumulator), and reload will fail\n\ |
3811 | if the required hard register is used for another purpose across such an\n\ |
3812 | insn.\n\ |
3813 | \n\ |
3814 | Passes before reload do not know which hard registers will be used\n\ |
3815 | in an instruction, but the machine modes of the registers set or used in\n\ |
3816 | the instruction are already known. And for some machines, register\n\ |
3817 | classes are small for, say, integer registers but not for floating point\n\ |
3818 | registers. For example, the AMD x86-64 architecture requires specific\n\ |
3819 | registers for the legacy x86 integer instructions, but there are many\n\ |
3820 | SSE registers for floating point operations. On such targets, a good\n\ |
3821 | strategy may be to return nonzero from this hook for @code{INTEGRAL_MODE_P}\n\ |
3822 | machine modes but zero for the SSE register classes.\n\ |
3823 | \n\ |
3824 | The default version of this hook returns false for any mode. It is always\n\ |
3825 | safe to redefine this hook to return with a nonzero value. But if you\n\ |
3826 | unnecessarily define it, you will reduce the amount of optimizations\n\ |
3827 | that can be performed in some cases. If you do not define this hook\n\ |
3828 | to return a nonzero value when it is required, the compiler will run out\n\ |
3829 | of spill registers and print a fatal error message." , |
3830 | bool, (machine_mode mode), |
3831 | hook_bool_mode_false) |
3832 | |
3833 | /* Register number for a flags register. Only needs to be defined if the |
3834 | target is constrainted to use post-reload comparison elimination. */ |
3835 | DEFHOOKPOD |
3836 | (flags_regnum, |
3837 | "If the target has a dedicated flags register, and it needs to use the\n\ |
3838 | post-reload comparison elimination pass, or the delay slot filler pass,\n\ |
3839 | then this value should be set appropriately." , |
3840 | unsigned int, INVALID_REGNUM) |
3841 | |
3842 | /* Compute a (partial) cost for rtx X. Return true if the complete |
3843 | cost has been computed, and false if subexpressions should be |
3844 | scanned. In either case, *TOTAL contains the cost result. */ |
3845 | /* Note that OUTER_CODE ought to be RTX_CODE, but that's |
3846 | not necessarily defined at this point. */ |
3847 | DEFHOOK |
3848 | (rtx_costs, |
3849 | "This target hook describes the relative costs of RTL expressions.\n\ |
3850 | \n\ |
3851 | The cost may depend on the precise form of the expression, which is\n\ |
3852 | available for examination in @var{x}, and the fact that @var{x} appears\n\ |
3853 | as operand @var{opno} of an expression with rtx code @var{outer_code}.\n\ |
3854 | That is, the hook can assume that there is some rtx @var{y} such\n\ |
3855 | that @samp{GET_CODE (@var{y}) == @var{outer_code}} and such that\n\ |
3856 | either (a) @samp{XEXP (@var{y}, @var{opno}) == @var{x}} or\n\ |
3857 | (b) @samp{XVEC (@var{y}, @var{opno})} contains @var{x}.\n\ |
3858 | \n\ |
3859 | @var{mode} is @var{x}'s machine mode, or for cases like @code{const_int} that\n\ |
3860 | do not have a mode, the mode in which @var{x} is used.\n\ |
3861 | \n\ |
3862 | In implementing this hook, you can use the construct\n\ |
3863 | @code{COSTS_N_INSNS (@var{n})} to specify a cost equal to @var{n} fast\n\ |
3864 | instructions.\n\ |
3865 | \n\ |
3866 | On entry to the hook, @code{*@var{total}} contains a default estimate\n\ |
3867 | for the cost of the expression. The hook should modify this value as\n\ |
3868 | necessary. Traditionally, the default costs are @code{COSTS_N_INSNS (5)}\n\ |
3869 | for multiplications, @code{COSTS_N_INSNS (7)} for division and modulus\n\ |
3870 | operations, and @code{COSTS_N_INSNS (1)} for all other operations.\n\ |
3871 | \n\ |
3872 | When optimizing for code size, i.e.@: when @code{speed} is\n\ |
3873 | false, this target hook should be used to estimate the relative\n\ |
3874 | size cost of an expression, again relative to @code{COSTS_N_INSNS}.\n\ |
3875 | \n\ |
3876 | The hook returns true when all subexpressions of @var{x} have been\n\ |
3877 | processed, and false when @code{rtx_cost} should recurse." , |
3878 | bool, (rtx x, machine_mode mode, int outer_code, int opno, int *total, bool speed), |
3879 | hook_bool_rtx_mode_int_int_intp_bool_false) |
3880 | |
3881 | /* Compute the cost of X, used as an address. Never called with |
3882 | invalid addresses. */ |
3883 | DEFHOOK |
3884 | (address_cost, |
3885 | "This hook computes the cost of an addressing mode that contains\n\ |
3886 | @var{address}. If not defined, the cost is computed from\n\ |
3887 | the @var{address} expression and the @code{TARGET_RTX_COST} hook.\n\ |
3888 | \n\ |
3889 | For most CISC machines, the default cost is a good approximation of the\n\ |
3890 | true cost of the addressing mode. However, on RISC machines, all\n\ |
3891 | instructions normally have the same length and execution time. Hence\n\ |
3892 | all addresses will have equal costs.\n\ |
3893 | \n\ |
3894 | In cases where more than one form of an address is known, the form with\n\ |
3895 | the lowest cost will be used. If multiple forms have the same, lowest,\n\ |
3896 | cost, the one that is the most complex will be used.\n\ |
3897 | \n\ |
3898 | For example, suppose an address that is equal to the sum of a register\n\ |
3899 | and a constant is used twice in the same basic block. When this macro\n\ |
3900 | is not defined, the address will be computed in a register and memory\n\ |
3901 | references will be indirect through that register. On machines where\n\ |
3902 | the cost of the addressing mode containing the sum is no higher than\n\ |
3903 | that of a simple indirect reference, this will produce an additional\n\ |
3904 | instruction and possibly require an additional register. Proper\n\ |
3905 | specification of this macro eliminates this overhead for such machines.\n\ |
3906 | \n\ |
3907 | This hook is never called with an invalid address.\n\ |
3908 | \n\ |
3909 | On machines where an address involving more than one register is as\n\ |
3910 | cheap as an address computation involving only one register, defining\n\ |
3911 | @code{TARGET_ADDRESS_COST} to reflect this can cause two registers to\n\ |
3912 | be live over a region of code where only one would have been if\n\ |
3913 | @code{TARGET_ADDRESS_COST} were not defined in that manner. This effect\n\ |
3914 | should be considered in the definition of this macro. Equivalent costs\n\ |
3915 | should probably only be given to addresses with different numbers of\n\ |
3916 | registers on machines with lots of registers." , |
3917 | int, (rtx address, machine_mode mode, addr_space_t as, bool speed), |
3918 | default_address_cost) |
3919 | |
3920 | /* Compute a cost for INSN. */ |
3921 | DEFHOOK |
3922 | (insn_cost, |
3923 | "This target hook describes the relative costs of RTL instructions.\n\ |
3924 | \n\ |
3925 | In implementing this hook, you can use the construct\n\ |
3926 | @code{COSTS_N_INSNS (@var{n})} to specify a cost equal to @var{n} fast\n\ |
3927 | instructions.\n\ |
3928 | \n\ |
3929 | When optimizing for code size, i.e.@: when @code{speed} is\n\ |
3930 | false, this target hook should be used to estimate the relative\n\ |
3931 | size cost of an expression, again relative to @code{COSTS_N_INSNS}." , |
3932 | int, (rtx_insn *insn, bool speed), NULL) |
3933 | |
3934 | /* Give a cost, in RTX Costs units, for an edge. Like BRANCH_COST, but with |
3935 | well defined units. */ |
3936 | DEFHOOK |
3937 | (max_noce_ifcvt_seq_cost, |
3938 | "This hook returns a value in the same units as @code{TARGET_RTX_COSTS},\n\ |
3939 | giving the maximum acceptable cost for a sequence generated by the RTL\n\ |
3940 | if-conversion pass when conditional execution is not available.\n\ |
3941 | The RTL if-conversion pass attempts to convert conditional operations\n\ |
3942 | that would require a branch to a series of unconditional operations and\n\ |
3943 | @code{mov@var{mode}cc} insns. This hook returns the maximum cost of the\n\ |
3944 | unconditional instructions and the @code{mov@var{mode}cc} insns.\n\ |
3945 | RTL if-conversion is cancelled if the cost of the converted sequence\n\ |
3946 | is greater than the value returned by this hook.\n\ |
3947 | \n\ |
3948 | @code{e} is the edge between the basic block containing the conditional\n\ |
3949 | branch to the basic block which would be executed if the condition\n\ |
3950 | were true.\n\ |
3951 | \n\ |
3952 | The default implementation of this hook uses the\n\ |
3953 | @code{max-rtl-if-conversion-[un]predictable} parameters if they are set,\n\ |
3954 | and uses a multiple of @code{BRANCH_COST} otherwise." , |
3955 | unsigned int, (edge e), |
3956 | default_max_noce_ifcvt_seq_cost) |
3957 | |
3958 | /* Return true if the given instruction sequence is a good candidate |
3959 | as a replacement for the if-convertible sequence. */ |
3960 | DEFHOOK |
3961 | (noce_conversion_profitable_p, |
3962 | "This hook returns true if the instruction sequence @code{seq} is a good\n\ |
3963 | candidate as a replacement for the if-convertible sequence described in\n\ |
3964 | @code{if_info}." , |
3965 | bool, (rtx_insn *seq, struct noce_if_info *if_info), |
3966 | default_noce_conversion_profitable_p) |
3967 | |
3968 | /* Return true if new_addr should be preferred over the existing address used by |
3969 | memref in insn. */ |
3970 | DEFHOOK |
3971 | (new_address_profitable_p, |
3972 | "Return @code{true} if it is profitable to replace the address in\n\ |
3973 | @var{memref} with @var{new_addr}. This allows targets to prevent the\n\ |
3974 | scheduler from undoing address optimizations. The instruction containing the\n\ |
3975 | memref is @var{insn}. The default implementation returns @code{true}." , |
3976 | bool, (rtx memref, rtx_insn * insn, rtx new_addr), |
3977 | default_new_address_profitable_p) |
3978 | |
3979 | DEFHOOK |
3980 | (estimated_poly_value, |
3981 | "Return an estimate of the runtime value of @var{val}, for use in\n\ |
3982 | things like cost calculations or profiling frequencies. @var{kind} is used\n\ |
3983 | to ask for the minimum, maximum, and likely estimates of the value through\n\ |
3984 | the @code{POLY_VALUE_MIN}, @code{POLY_VALUE_MAX} and\n\ |
3985 | @code{POLY_VALUE_LIKELY} values. The default\n\ |
3986 | implementation returns the lowest possible value of @var{val}." , |
3987 | HOST_WIDE_INT, (poly_int64 val, poly_value_estimate_kind kind), |
3988 | default_estimated_poly_value) |
3989 | |
3990 | /* Permit speculative instructions in delay slots during delayed-branch |
3991 | scheduling. */ |
3992 | DEFHOOK |
3993 | (no_speculation_in_delay_slots_p, |
3994 | "This predicate controls the use of the eager delay slot filler to disallow\n\ |
3995 | speculatively executed instructions being placed in delay slots. Targets\n\ |
3996 | such as certain MIPS architectures possess both branches with and without\n\ |
3997 | delay slots. As the eager delay slot filler can decrease performance,\n\ |
3998 | disabling it is beneficial when ordinary branches are available. Use of\n\ |
3999 | delay slot branches filled using the basic filler is often still desirable\n\ |
4000 | as the delay slot can hide a pipeline bubble." , |
4001 | bool, (void), |
4002 | hook_bool_void_false) |
4003 | |
4004 | /* Return where to allocate pseudo for a given hard register initial value. */ |
4005 | DEFHOOK |
4006 | (allocate_initial_value, |
4007 | "\n\ |
4008 | When the initial value of a hard register has been copied in a pseudo\n\ |
4009 | register, it is often not necessary to actually allocate another register\n\ |
4010 | to this pseudo register, because the original hard register or a stack slot\n\ |
4011 | it has been saved into can be used. @code{TARGET_ALLOCATE_INITIAL_VALUE}\n\ |
4012 | is called at the start of register allocation once for each hard register\n\ |
4013 | that had its initial value copied by using\n\ |
4014 | @code{get_func_hard_reg_initial_val} or @code{get_hard_reg_initial_val}.\n\ |
4015 | Possible values are @code{NULL_RTX}, if you don't want\n\ |
4016 | to do any special allocation, a @code{REG} rtx---that would typically be\n\ |
4017 | the hard register itself, if it is known not to be clobbered---or a\n\ |
4018 | @code{MEM}.\n\ |
4019 | If you are returning a @code{MEM}, this is only a hint for the allocator;\n\ |
4020 | it might decide to use another register anyways.\n\ |
4021 | You may use @code{current_function_is_leaf} or \n\ |
4022 | @code{REG_N_SETS} in the hook to determine if the hard\n\ |
4023 | register in question will not be clobbered.\n\ |
4024 | The default value of this hook is @code{NULL}, which disables any special\n\ |
4025 | allocation." , |
4026 | rtx, (rtx hard_reg), NULL) |
4027 | |
4028 | /* Return nonzero if evaluating UNSPEC X might cause a trap. |
4029 | FLAGS has the same meaning as in rtlanal.cc: may_trap_p_1. */ |
4030 | DEFHOOK |
4031 | (unspec_may_trap_p, |
4032 | "This target hook returns nonzero if @var{x}, an @code{unspec} or\n\ |
4033 | @code{unspec_volatile} operation, might cause a trap. Targets can use\n\ |
4034 | this hook to enhance precision of analysis for @code{unspec} and\n\ |
4035 | @code{unspec_volatile} operations. You may call @code{may_trap_p_1}\n\ |
4036 | to analyze inner elements of @var{x} in which case @var{flags} should be\n\ |
4037 | passed along." , |
4038 | int, (const_rtx x, unsigned flags), |
4039 | default_unspec_may_trap_p) |
4040 | |
4041 | /* Given a register, this hook should return a parallel of registers |
4042 | to represent where to find the register pieces. Define this hook |
4043 | if the register and its mode are represented in Dwarf in |
4044 | non-contiguous locations, or if the register should be |
4045 | represented in more than one register in Dwarf. Otherwise, this |
4046 | hook should return NULL_RTX. */ |
4047 | DEFHOOK |
4048 | (dwarf_register_span, |
4049 | "Given a register, this hook should return a parallel of registers to\n\ |
4050 | represent where to find the register pieces. Define this hook if the\n\ |
4051 | register and its mode are represented in Dwarf in non-contiguous\n\ |
4052 | locations, or if the register should be represented in more than one\n\ |
4053 | register in Dwarf. Otherwise, this hook should return @code{NULL_RTX}.\n\ |
4054 | If not defined, the default is to return @code{NULL_RTX}." , |
4055 | rtx, (rtx reg), |
4056 | hook_rtx_rtx_null) |
4057 | |
4058 | /* Given a register return the mode of the corresponding DWARF frame |
4059 | register. */ |
4060 | DEFHOOK |
4061 | (dwarf_frame_reg_mode, |
4062 | "Given a register, this hook should return the mode which the\n\ |
4063 | corresponding Dwarf frame register should have. This is normally\n\ |
4064 | used to return a smaller mode than the raw mode to prevent call\n\ |
4065 | clobbered parts of a register altering the frame register size" , |
4066 | machine_mode, (int regno), |
4067 | default_dwarf_frame_reg_mode) |
4068 | |
4069 | /* If expand_builtin_init_dwarf_reg_sizes needs to fill in table |
4070 | entries not corresponding directly to registers below |
4071 | FIRST_PSEUDO_REGISTER, this hook should generate the necessary |
4072 | code, given the address of the table. */ |
4073 | DEFHOOK |
4074 | (, |
4075 | "If some registers are represented in Dwarf-2 unwind information in\n\ |
4076 | multiple pieces, define this hook to fill in information about the\n\ |
4077 | sizes of those pieces in the table used by the unwinder at runtime.\n\ |
4078 | It will be called by @code{expand_builtin_init_dwarf_reg_sizes} after\n\ |
4079 | filling in a single size corresponding to each hard register;\n\ |
4080 | @var{address} is the address of the table." , |
4081 | void, (tree address), |
4082 | hook_void_tree) |
4083 | |
4084 | /* Fetch the fixed register(s) which hold condition codes, for |
4085 | targets where it makes sense to look for duplicate assignments to |
4086 | the condition codes. This should return true if there is such a |
4087 | register, false otherwise. The arguments should be set to the |
4088 | fixed register numbers. Up to two condition code registers are |
4089 | supported. If there is only one for this target, the int pointed |
4090 | at by the second argument should be set to -1. */ |
4091 | DEFHOOK |
4092 | (fixed_condition_code_regs, |
4093 | "On targets which use a hard\n\ |
4094 | register rather than a pseudo-register to hold condition codes, the\n\ |
4095 | regular CSE passes are often not able to identify cases in which the\n\ |
4096 | hard register is set to a common value. Use this hook to enable a\n\ |
4097 | small pass which optimizes such cases. This hook should return true\n\ |
4098 | to enable this pass, and it should set the integers to which its\n\ |
4099 | arguments point to the hard register numbers used for condition codes.\n\ |
4100 | When there is only one such register, as is true on most systems, the\n\ |
4101 | integer pointed to by @var{p2} should be set to\n\ |
4102 | @code{INVALID_REGNUM}.\n\ |
4103 | \n\ |
4104 | The default version of this hook returns false." , |
4105 | bool, (unsigned int *p1, unsigned int *p2), |
4106 | hook_bool_uintp_uintp_false) |
4107 | |
4108 | /* If two condition code modes are compatible, return a condition |
4109 | code mode which is compatible with both, such that a comparison |
4110 | done in the returned mode will work for both of the original |
4111 | modes. If the condition code modes are not compatible, return |
4112 | VOIDmode. */ |
4113 | DEFHOOK |
4114 | (cc_modes_compatible, |
4115 | "On targets which use multiple condition code modes in class\n\ |
4116 | @code{MODE_CC}, it is sometimes the case that a comparison can be\n\ |
4117 | validly done in more than one mode. On such a system, define this\n\ |
4118 | target hook to take two mode arguments and to return a mode in which\n\ |
4119 | both comparisons may be validly done. If there is no such mode,\n\ |
4120 | return @code{VOIDmode}.\n\ |
4121 | \n\ |
4122 | The default version of this hook checks whether the modes are the\n\ |
4123 | same. If they are, it returns that mode. If they are different, it\n\ |
4124 | returns @code{VOIDmode}." , |
4125 | machine_mode, (machine_mode m1, machine_mode m2), |
4126 | default_cc_modes_compatible) |
4127 | |
4128 | /* Do machine-dependent code transformations. Called just before |
4129 | delayed-branch scheduling. */ |
4130 | DEFHOOK |
4131 | (machine_dependent_reorg, |
4132 | "If non-null, this hook performs a target-specific pass over the\n\ |
4133 | instruction stream. The compiler will run it at all optimization levels,\n\ |
4134 | just before the point at which it normally does delayed-branch scheduling.\n\ |
4135 | \n\ |
4136 | The exact purpose of the hook varies from target to target. Some use\n\ |
4137 | it to do transformations that are necessary for correctness, such as\n\ |
4138 | laying out in-function constant pools or avoiding hardware hazards.\n\ |
4139 | Others use it as an opportunity to do some machine-dependent optimizations.\n\ |
4140 | \n\ |
4141 | You need not implement the hook if it has nothing to do. The default\n\ |
4142 | definition is null." , |
4143 | void, (void), NULL) |
4144 | |
4145 | /* Create the __builtin_va_list type. */ |
4146 | DEFHOOK |
4147 | (build_builtin_va_list, |
4148 | "This hook returns a type node for @code{va_list} for the target.\n\ |
4149 | The default version of the hook returns @code{void*}." , |
4150 | tree, (void), |
4151 | std_build_builtin_va_list) |
4152 | |
4153 | /* Enumerate the va list variants. */ |
4154 | DEFHOOK |
4155 | (enum_va_list_p, |
4156 | "This target hook is used in function @code{c_common_nodes_and_builtins}\n\ |
4157 | to iterate through the target specific builtin types for va_list. The\n\ |
4158 | variable @var{idx} is used as iterator. @var{pname} has to be a pointer\n\ |
4159 | to a @code{const char *} and @var{ptree} a pointer to a @code{tree} typed\n\ |
4160 | variable.\n\ |
4161 | The arguments @var{pname} and @var{ptree} are used to store the result of\n\ |
4162 | this macro and are set to the name of the va_list builtin type and its\n\ |
4163 | internal type.\n\ |
4164 | If the return value of this macro is zero, then there is no more element.\n\ |
4165 | Otherwise the @var{IDX} should be increased for the next call of this\n\ |
4166 | macro to iterate through all types." , |
4167 | int, (int idx, const char **pname, tree *ptree), |
4168 | NULL) |
4169 | |
4170 | /* Get the cfun/fndecl calling abi __builtin_va_list type. */ |
4171 | DEFHOOK |
4172 | (fn_abi_va_list, |
4173 | "This hook returns the va_list type of the calling convention specified by\n\ |
4174 | @var{fndecl}.\n\ |
4175 | The default version of this hook returns @code{va_list_type_node}." , |
4176 | tree, (tree fndecl), |
4177 | std_fn_abi_va_list) |
4178 | |
4179 | /* Get the __builtin_va_list type dependent on input type. */ |
4180 | DEFHOOK |
4181 | (canonical_va_list_type, |
4182 | "This hook returns the va_list type of the calling convention specified by the\n\ |
4183 | type of @var{type}. If @var{type} is not a valid va_list type, it returns\n\ |
4184 | @code{NULL_TREE}." , |
4185 | tree, (tree type), |
4186 | std_canonical_va_list_type) |
4187 | |
4188 | /* ??? Documenting this hook requires a GFDL license grant. */ |
4189 | DEFHOOK_UNDOC |
4190 | (expand_builtin_va_start, |
4191 | "Expand the @code{__builtin_va_start} builtin." , |
4192 | void, (tree valist, rtx nextarg), NULL) |
4193 | |
4194 | /* Gimplifies a VA_ARG_EXPR. */ |
4195 | DEFHOOK |
4196 | (gimplify_va_arg_expr, |
4197 | "This hook performs target-specific gimplification of\n\ |
4198 | @code{VA_ARG_EXPR}. The first two parameters correspond to the\n\ |
4199 | arguments to @code{va_arg}; the latter two are as in\n\ |
4200 | @code{gimplify.cc:gimplify_expr}." , |
4201 | tree, (tree valist, tree type, gimple_seq *pre_p, gimple_seq *post_p), |
4202 | std_gimplify_va_arg_expr) |
4203 | |
4204 | /* Validity-checking routines for PCH files, target-specific. |
4205 | get_pch_validity returns a pointer to the data to be stored, |
4206 | and stores the size in its argument. pch_valid_p gets the same |
4207 | information back and returns NULL if the PCH is valid, |
4208 | or an error message if not. */ |
4209 | DEFHOOK |
4210 | (get_pch_validity, |
4211 | "This hook returns a pointer to the data needed by\n\ |
4212 | @code{TARGET_PCH_VALID_P} and sets\n\ |
4213 | @samp{*@var{sz}} to the size of the data in bytes." , |
4214 | void *, (size_t *sz), |
4215 | default_get_pch_validity) |
4216 | |
4217 | DEFHOOK |
4218 | (pch_valid_p, |
4219 | "This hook checks whether the options used to create a PCH file are\n\ |
4220 | compatible with the current settings. It returns @code{NULL}\n\ |
4221 | if so and a suitable error message if not. Error messages will\n\ |
4222 | be presented to the user and must be localized using @samp{_(@var{msg})}.\n\ |
4223 | \n\ |
4224 | @var{data} is the data that was returned by @code{TARGET_GET_PCH_VALIDITY}\n\ |
4225 | when the PCH file was created and @var{sz} is the size of that data in bytes.\n\ |
4226 | It's safe to assume that the data was created by the same version of the\n\ |
4227 | compiler, so no format checking is needed.\n\ |
4228 | \n\ |
4229 | The default definition of @code{default_pch_valid_p} should be\n\ |
4230 | suitable for most targets." , |
4231 | const char *, (const void *data, size_t sz), |
4232 | default_pch_valid_p) |
4233 | |
4234 | DEFHOOK |
4235 | (prepare_pch_save, |
4236 | "Called before writing out a PCH file. If the target has some\n\ |
4237 | garbage-collected data that needs to be in a particular state on PCH loads,\n\ |
4238 | it can use this hook to enforce that state. Very few targets need\n\ |
4239 | to do anything here." , |
4240 | void, (void), |
4241 | hook_void_void) |
4242 | |
4243 | /* If nonnull, this function checks whether a PCH file with the |
4244 | given set of target flags can be used. It returns NULL if so, |
4245 | otherwise it returns an error message. */ |
4246 | DEFHOOK |
4247 | (check_pch_target_flags, |
4248 | "If this hook is nonnull, the default implementation of\n\ |
4249 | @code{TARGET_PCH_VALID_P} will use it to check for compatible values\n\ |
4250 | of @code{target_flags}. @var{pch_flags} specifies the value that\n\ |
4251 | @code{target_flags} had when the PCH file was created. The return\n\ |
4252 | value is the same as for @code{TARGET_PCH_VALID_P}." , |
4253 | const char *, (int pch_flags), NULL) |
4254 | |
4255 | /* True if the compiler should give an enum type only as many |
4256 | bytes as it takes to represent the range of possible values of |
4257 | that type. */ |
4258 | DEFHOOK |
4259 | (default_short_enums, |
4260 | "This target hook should return true if the compiler should give an\n\ |
4261 | @code{enum} type only as many bytes as it takes to represent the range\n\ |
4262 | of possible values of that type. It should return false if all\n\ |
4263 | @code{enum} types should be allocated like @code{int}.\n\ |
4264 | \n\ |
4265 | The default is to return false." , |
4266 | bool, (void), |
4267 | hook_bool_void_false) |
4268 | |
4269 | /* This target hook returns an rtx that is used to store the address |
4270 | of the current frame into the built-in setjmp buffer. */ |
4271 | DEFHOOK |
4272 | (builtin_setjmp_frame_value, |
4273 | "This target hook should return an rtx that is used to store\n\ |
4274 | the address of the current frame into the built in @code{setjmp} buffer.\n\ |
4275 | The default value, @code{virtual_stack_vars_rtx}, is correct for most\n\ |
4276 | machines. One reason you may need to define this target hook is if\n\ |
4277 | @code{hard_frame_pointer_rtx} is the appropriate value on your machine." , |
4278 | rtx, (void), |
4279 | default_builtin_setjmp_frame_value) |
4280 | |
4281 | /* This target hook should manipulate the outputs, inputs, constraints, |
4282 | and clobbers the port wishes for pre-processing the asm. */ |
4283 | DEFHOOK |
4284 | (md_asm_adjust, |
4285 | "This target hook may add @dfn{clobbers} to @var{clobbers} and\n\ |
4286 | @var{clobbered_regs} for any hard regs the port wishes to automatically\n\ |
4287 | clobber for an asm. The @var{outputs} and @var{inputs} may be inspected\n\ |
4288 | to avoid clobbering a register that is already used by the asm. @var{loc}\n\ |
4289 | is the source location of the asm.\n\ |
4290 | \n\ |
4291 | It may modify the @var{outputs}, @var{inputs}, @var{input_modes}, and\n\ |
4292 | @var{constraints} as necessary for other pre-processing. In this case the\n\ |
4293 | return value is a sequence of insns to emit after the asm. Note that\n\ |
4294 | changes to @var{inputs} must be accompanied by the corresponding changes\n\ |
4295 | to @var{input_modes}." , |
4296 | rtx_insn *, |
4297 | (vec<rtx>& outputs, vec<rtx>& inputs, vec<machine_mode>& input_modes, |
4298 | vec<const char *>& constraints, vec<rtx>& clobbers, |
4299 | HARD_REG_SET& clobbered_regs, location_t loc), |
4300 | NULL) |
4301 | |
4302 | /* This target hook allows the backend to specify a calling convention |
4303 | in the debug information. This function actually returns an |
4304 | enum dwarf_calling_convention, but because of forward declarations |
4305 | and not wanting to include dwarf2.h everywhere target.h is included |
4306 | the function is being declared as an int. */ |
4307 | DEFHOOK |
4308 | (dwarf_calling_convention, |
4309 | "Define this to enable the dwarf attribute @code{DW_AT_calling_convention} to\n\ |
4310 | be emitted for each function. Instead of an integer return the enum\n\ |
4311 | value for the @code{DW_CC_} tag." , |
4312 | int, (const_tree function), |
4313 | hook_int_const_tree_0) |
4314 | |
4315 | /* This target hook allows the backend to emit frame-related insns that |
4316 | contain UNSPECs or UNSPEC_VOLATILEs. The call frame debugging info |
4317 | engine will invoke it on insns of the form |
4318 | (set (reg) (unspec [...] UNSPEC_INDEX)) |
4319 | and |
4320 | (set (reg) (unspec_volatile [...] UNSPECV_INDEX)) |
4321 | to let the backend emit the call frame instructions. */ |
4322 | DEFHOOK |
4323 | (dwarf_handle_frame_unspec, |
4324 | "This target hook allows the backend to emit frame-related insns that\n\ |
4325 | contain UNSPECs or UNSPEC_VOLATILEs. The DWARF 2 call frame debugging\n\ |
4326 | info engine will invoke it on insns of the form\n\ |
4327 | @smallexample\n\ |
4328 | (set (reg) (unspec [@dots{}] UNSPEC_INDEX))\n\ |
4329 | @end smallexample\n\ |
4330 | and\n\ |
4331 | @smallexample\n\ |
4332 | (set (reg) (unspec_volatile [@dots{}] UNSPECV_INDEX)).\n\ |
4333 | @end smallexample\n\ |
4334 | to let the backend emit the call frame instructions. @var{label} is\n\ |
4335 | the CFI label attached to the insn, @var{pattern} is the pattern of\n\ |
4336 | the insn and @var{index} is @code{UNSPEC_INDEX} or @code{UNSPECV_INDEX}." , |
4337 | void, (const char *label, rtx pattern, int index), NULL) |
4338 | |
4339 | DEFHOOK |
4340 | (dwarf_poly_indeterminate_value, |
4341 | "Express the value of @code{poly_int} indeterminate @var{i} as a DWARF\n\ |
4342 | expression, with @var{i} counting from 1. Return the number of a DWARF\n\ |
4343 | register @var{R} and set @samp{*@var{factor}} and @samp{*@var{offset}} such\n\ |
4344 | that the value of the indeterminate is:\n\ |
4345 | @smallexample\n\ |
4346 | value_of(@var{R}) / @var{factor} - @var{offset}\n\ |
4347 | @end smallexample\n\ |
4348 | \n\ |
4349 | A target only needs to define this hook if it sets\n\ |
4350 | @samp{NUM_POLY_INT_COEFFS} to a value greater than 1." , |
4351 | unsigned int, (unsigned int i, unsigned int *factor, int *offset), |
4352 | default_dwarf_poly_indeterminate_value) |
4353 | |
4354 | /* ??? Documenting this hook requires a GFDL license grant. */ |
4355 | DEFHOOK_UNDOC |
4356 | (stdarg_optimize_hook, |
4357 | "Perform architecture specific checking of statements gimplified\ |
4358 | from @code{VA_ARG_EXPR}. @var{stmt} is the statement. Returns true if\ |
4359 | the statement doesn't need to be checked for @code{va_list} references." , |
4360 | bool, (struct stdarg_info *ai, const gimple *stmt), NULL) |
4361 | |
4362 | /* This target hook allows the operating system to override the DECL |
4363 | that represents the external variable that contains the stack |
4364 | protection guard variable. The type of this DECL is ptr_type_node. */ |
4365 | DEFHOOK |
4366 | (stack_protect_guard, |
4367 | "This hook returns a @code{DECL} node for the external variable to use\n\ |
4368 | for the stack protection guard. This variable is initialized by the\n\ |
4369 | runtime to some random value and is used to initialize the guard value\n\ |
4370 | that is placed at the top of the local stack frame. The type of this\n\ |
4371 | variable must be @code{ptr_type_node}.\n\ |
4372 | \n\ |
4373 | The default version of this hook creates a variable called\n\ |
4374 | @samp{__stack_chk_guard}, which is normally defined in @file{libgcc2.c}." , |
4375 | tree, (void), |
4376 | default_stack_protect_guard) |
4377 | |
4378 | /* This target hook allows the operating system to override the CALL_EXPR |
4379 | that is invoked when a check vs the guard variable fails. */ |
4380 | DEFHOOK |
4381 | (stack_protect_fail, |
4382 | "This hook returns a @code{CALL_EXPR} that alerts the runtime that the\n\ |
4383 | stack protect guard variable has been modified. This expression should\n\ |
4384 | involve a call to a @code{noreturn} function.\n\ |
4385 | \n\ |
4386 | The default version of this hook invokes a function called\n\ |
4387 | @samp{__stack_chk_fail}, taking no arguments. This function is\n\ |
4388 | normally defined in @file{libgcc2.c}." , |
4389 | tree, (void), |
4390 | default_external_stack_protect_fail) |
4391 | |
4392 | /* This target hook allows the operating system to disable the default stack |
4393 | protector runtime support. */ |
4394 | DEFHOOK |
4395 | (stack_protect_runtime_enabled_p, |
4396 | "Returns true if the target wants GCC's default stack protect runtime support,\n\ |
4397 | otherwise return false. The default implementation always returns true." , |
4398 | bool, (void), |
4399 | hook_bool_void_true) |
4400 | |
4401 | DEFHOOK |
4402 | (have_speculation_safe_value, |
4403 | "This hook is used to determine the level of target support for\n\ |
4404 | @code{__builtin_speculation_safe_value}. If called with an argument\n\ |
4405 | of false, it returns true if the target has been modified to support\n\ |
4406 | this builtin. If called with an argument of true, it returns true\n\ |
4407 | if the target requires active mitigation execution might be speculative.\n\ |
4408 | \n\ |
4409 | The default implementation returns false if the target does not define\n\ |
4410 | a pattern named @code{speculation_barrier}. Else it returns true\n\ |
4411 | for the first case and whether the pattern is enabled for the current\n\ |
4412 | compilation for the second case.\n\ |
4413 | \n\ |
4414 | For targets that have no processors that can execute instructions\n\ |
4415 | speculatively an alternative implemenation of this hook is available:\n\ |
4416 | simply redefine this hook to @code{speculation_safe_value_not_needed}\n\ |
4417 | along with your other target hooks." , |
4418 | bool, (bool active), default_have_speculation_safe_value) |
4419 | |
4420 | DEFHOOK |
4421 | (speculation_safe_value, |
4422 | "This target hook can be used to generate a target-specific code\n\ |
4423 | sequence that implements the @code{__builtin_speculation_safe_value}\n\ |
4424 | built-in function. The function must always return @var{val} in\n\ |
4425 | @var{result} in mode @var{mode} when the cpu is not executing\n\ |
4426 | speculatively, but must never return that when speculating until it\n\ |
4427 | is known that the speculation will not be unwound. The hook supports\n\ |
4428 | two primary mechanisms for implementing the requirements. The first\n\ |
4429 | is to emit a speculation barrier which forces the processor to wait\n\ |
4430 | until all prior speculative operations have been resolved; the second\n\ |
4431 | is to use a target-specific mechanism that can track the speculation\n\ |
4432 | state and to return @var{failval} if it can determine that\n\ |
4433 | speculation must be unwound at a later time.\n\ |
4434 | \n\ |
4435 | The default implementation simply copies @var{val} to @var{result} and\n\ |
4436 | emits a @code{speculation_barrier} instruction if that is defined." , |
4437 | rtx, (machine_mode mode, rtx result, rtx val, rtx failval), |
4438 | default_speculation_safe_value) |
4439 | |
4440 | DEFHOOK |
4441 | (predict_doloop_p, |
4442 | "Return true if we can predict it is possible to use a low-overhead loop\n\ |
4443 | for a particular loop. The parameter @var{loop} is a pointer to the loop.\n\ |
4444 | This target hook is required only when the target supports low-overhead\n\ |
4445 | loops, and will help ivopts to make some decisions.\n\ |
4446 | The default version of this hook returns false." , |
4447 | bool, (class loop *loop), |
4448 | default_predict_doloop_p) |
4449 | |
4450 | DEFHOOKPOD |
4451 | (have_count_reg_decr_p, |
4452 | "Return true if the target supports hardware count register for decrement\n\ |
4453 | and branch.\n\ |
4454 | The default value is false." , |
4455 | bool, false) |
4456 | |
4457 | DEFHOOKPOD |
4458 | (doloop_cost_for_generic, |
4459 | "One IV candidate dedicated for doloop is introduced in IVOPTs, we can\n\ |
4460 | calculate the computation cost of adopting it to any generic IV use by\n\ |
4461 | function get_computation_cost as before. But for targets which have\n\ |
4462 | hardware count register support for decrement and branch, it may have to\n\ |
4463 | move IV value from hardware count register to general purpose register\n\ |
4464 | while doloop IV candidate is used for generic IV uses. It probably takes\n\ |
4465 | expensive penalty. This hook allows target owners to define the cost for\n\ |
4466 | this especially for generic IV uses.\n\ |
4467 | The default value is zero." , |
4468 | int64_t, 0) |
4469 | |
4470 | DEFHOOKPOD |
4471 | (doloop_cost_for_address, |
4472 | "One IV candidate dedicated for doloop is introduced in IVOPTs, we can\n\ |
4473 | calculate the computation cost of adopting it to any address IV use by\n\ |
4474 | function get_computation_cost as before. But for targets which have\n\ |
4475 | hardware count register support for decrement and branch, it may have to\n\ |
4476 | move IV value from hardware count register to general purpose register\n\ |
4477 | while doloop IV candidate is used for address IV uses. It probably takes\n\ |
4478 | expensive penalty. This hook allows target owners to define the cost for\n\ |
4479 | this escpecially for address IV uses.\n\ |
4480 | The default value is zero." , |
4481 | int64_t, 0) |
4482 | |
4483 | DEFHOOK |
4484 | (can_use_doloop_p, |
4485 | "Return true if it is possible to use low-overhead loops (@code{doloop_end}\n\ |
4486 | and @code{doloop_begin}) for a particular loop. @var{iterations} gives the\n\ |
4487 | exact number of iterations, or 0 if not known. @var{iterations_max} gives\n\ |
4488 | the maximum number of iterations, or 0 if not known. @var{loop_depth} is\n\ |
4489 | the nesting depth of the loop, with 1 for innermost loops, 2 for loops that\n\ |
4490 | contain innermost loops, and so on. @var{entered_at_top} is true if the\n\ |
4491 | loop is only entered from the top.\n\ |
4492 | \n\ |
4493 | This hook is only used if @code{doloop_end} is available. The default\n\ |
4494 | implementation returns true. You can use @code{can_use_doloop_if_innermost}\n\ |
4495 | if the loop must be the innermost, and if there are no other restrictions." , |
4496 | bool, (const widest_int &iterations, const widest_int &iterations_max, |
4497 | unsigned int loop_depth, bool entered_at_top), |
4498 | hook_bool_wint_wint_uint_bool_true) |
4499 | |
4500 | /* Returns NULL if target supports the insn within a doloop block, |
4501 | otherwise it returns an error message. */ |
4502 | DEFHOOK |
4503 | (invalid_within_doloop, |
4504 | "\n\ |
4505 | Take an instruction in @var{insn} and return NULL if it is valid within a\n\ |
4506 | low-overhead loop, otherwise return a string explaining why doloop\n\ |
4507 | could not be applied.\n\ |
4508 | \n\ |
4509 | Many targets use special registers for low-overhead looping. For any\n\ |
4510 | instruction that clobbers these this function should return a string indicating\n\ |
4511 | the reason why the doloop could not be applied.\n\ |
4512 | By default, the RTL loop optimizer does not use a present doloop pattern for\n\ |
4513 | loops containing function calls or branch on table instructions." , |
4514 | const char *, (const rtx_insn *insn), |
4515 | default_invalid_within_doloop) |
4516 | |
4517 | /* Returns the machine mode which the target prefers for doloop IV. */ |
4518 | DEFHOOK |
4519 | (preferred_doloop_mode, |
4520 | "This hook takes a @var{mode} for a doloop IV, where @code{mode} is the\n\ |
4521 | original mode for the operation. If the target prefers an alternate\n\ |
4522 | @code{mode} for the operation, then this hook should return that mode;\n\ |
4523 | otherwise the original @code{mode} should be returned. For example, on a\n\ |
4524 | 64-bit target, @code{DImode} might be preferred over @code{SImode}. Both the\n\ |
4525 | original and the returned modes should be @code{MODE_INT}." , |
4526 | machine_mode, |
4527 | (machine_mode mode), |
4528 | default_preferred_doloop_mode) |
4529 | |
4530 | /* Returns true for a legitimate combined insn. */ |
4531 | DEFHOOK |
4532 | (legitimate_combined_insn, |
4533 | "Take an instruction in @var{insn} and return @code{false} if the instruction\n\ |
4534 | is not appropriate as a combination of two or more instructions. The\n\ |
4535 | default is to accept all instructions." , |
4536 | bool, (rtx_insn *insn), |
4537 | hook_bool_rtx_insn_true) |
4538 | |
4539 | DEFHOOK |
4540 | (valid_dllimport_attribute_p, |
4541 | "@var{decl} is a variable or function with @code{__attribute__((dllimport))}\n\ |
4542 | specified. Use this hook if the target needs to add extra validation\n\ |
4543 | checks to @code{handle_dll_attribute}." , |
4544 | bool, (const_tree decl), |
4545 | hook_bool_const_tree_true) |
4546 | |
4547 | /* If non-zero, align constant anchors in CSE to a multiple of this |
4548 | value. */ |
4549 | DEFHOOKPOD |
4550 | (const_anchor, |
4551 | "On some architectures it can take multiple instructions to synthesize\n\ |
4552 | a constant. If there is another constant already in a register that\n\ |
4553 | is close enough in value then it is preferable that the new constant\n\ |
4554 | is computed from this register using immediate addition or\n\ |
4555 | subtraction. We accomplish this through CSE. Besides the value of\n\ |
4556 | the constant we also add a lower and an upper constant anchor to the\n\ |
4557 | available expressions. These are then queried when encountering new\n\ |
4558 | constants. The anchors are computed by rounding the constant up and\n\ |
4559 | down to a multiple of the value of @code{TARGET_CONST_ANCHOR}.\n\ |
4560 | @code{TARGET_CONST_ANCHOR} should be the maximum positive value\n\ |
4561 | accepted by immediate-add plus one. We currently assume that the\n\ |
4562 | value of @code{TARGET_CONST_ANCHOR} is a power of 2. For example, on\n\ |
4563 | MIPS, where add-immediate takes a 16-bit signed value,\n\ |
4564 | @code{TARGET_CONST_ANCHOR} is set to @samp{0x8000}. The default value\n\ |
4565 | is zero, which disables this optimization." , |
4566 | unsigned HOST_WIDE_INT, 0) |
4567 | |
4568 | /* Defines, which target-dependent bits (upper 16) are used by port */ |
4569 | DEFHOOK |
4570 | (memmodel_check, |
4571 | "Validate target specific memory model mask bits. When NULL no target specific\n\ |
4572 | memory model bits are allowed." , |
4573 | unsigned HOST_WIDE_INT, (unsigned HOST_WIDE_INT val), NULL) |
4574 | |
4575 | /* Defines an offset bitwise ored into shifted address to get corresponding |
4576 | Address Sanitizer shadow address, or -1 if Address Sanitizer is not |
4577 | supported by the target. */ |
4578 | DEFHOOK |
4579 | (asan_shadow_offset, |
4580 | "Return the offset bitwise ored into shifted address to get corresponding\n\ |
4581 | Address Sanitizer shadow memory address. NULL if Address Sanitizer is not\n\ |
4582 | supported by the target. May return 0 if Address Sanitizer is not supported\n\ |
4583 | by a subtarget." , |
4584 | unsigned HOST_WIDE_INT, (void), |
4585 | NULL) |
4586 | |
4587 | /* Functions relating to calls - argument passing, returns, etc. */ |
4588 | /* Members of struct call have no special macro prefix. */ |
4589 | HOOK_VECTOR (TARGET_CALLS, calls) |
4590 | |
4591 | DEFHOOK |
4592 | (promote_function_mode, |
4593 | "Like @code{PROMOTE_MODE}, but it is applied to outgoing function arguments or\n\ |
4594 | function return values. The target hook should return the new mode\n\ |
4595 | and possibly change @code{*@var{punsignedp}} if the promotion should\n\ |
4596 | change signedness. This function is called only for scalar @emph{or\n\ |
4597 | pointer} types.\n\ |
4598 | \n\ |
4599 | @var{for_return} allows to distinguish the promotion of arguments and\n\ |
4600 | return values. If it is @code{1}, a return value is being promoted and\n\ |
4601 | @code{TARGET_FUNCTION_VALUE} must perform the same promotions done here.\n\ |
4602 | If it is @code{2}, the returned mode should be that of the register in\n\ |
4603 | which an incoming parameter is copied, or the outgoing result is computed;\n\ |
4604 | then the hook should return the same mode as @code{promote_mode}, though\n\ |
4605 | the signedness may be different.\n\ |
4606 | \n\ |
4607 | @var{type} can be NULL when promoting function arguments of libcalls.\n\ |
4608 | \n\ |
4609 | The default is to not promote arguments and return values. You can\n\ |
4610 | also define the hook to @code{default_promote_function_mode_always_promote}\n\ |
4611 | if you would like to apply the same rules given by @code{PROMOTE_MODE}." , |
4612 | machine_mode, (const_tree type, machine_mode mode, int *punsignedp, |
4613 | const_tree funtype, int for_return), |
4614 | default_promote_function_mode) |
4615 | |
4616 | DEFHOOK |
4617 | (promote_prototypes, |
4618 | "This target hook returns @code{true} if an argument declared in a\n\ |
4619 | prototype as an integral type smaller than @code{int} should actually be\n\ |
4620 | passed as an @code{int}. In addition to avoiding errors in certain\n\ |
4621 | cases of mismatch, it also makes for better code on certain machines.\n\ |
4622 | The default is to not promote prototypes." , |
4623 | bool, (const_tree fntype), |
4624 | hook_bool_const_tree_false) |
4625 | |
4626 | DEFHOOK |
4627 | (struct_value_rtx, |
4628 | "This target hook should return the location of the structure value\n\ |
4629 | address (normally a @code{mem} or @code{reg}), or 0 if the address is\n\ |
4630 | passed as an ``invisible'' first argument. Note that @var{fndecl} may\n\ |
4631 | be @code{NULL}, for libcalls. You do not need to define this target\n\ |
4632 | hook if the address is always passed as an ``invisible'' first\n\ |
4633 | argument.\n\ |
4634 | \n\ |
4635 | On some architectures the place where the structure value address\n\ |
4636 | is found by the called function is not the same place that the\n\ |
4637 | caller put it. This can be due to register windows, or it could\n\ |
4638 | be because the function prologue moves it to a different place.\n\ |
4639 | @var{incoming} is @code{1} or @code{2} when the location is needed in\n\ |
4640 | the context of the called function, and @code{0} in the context of\n\ |
4641 | the caller.\n\ |
4642 | \n\ |
4643 | If @var{incoming} is nonzero and the address is to be found on the\n\ |
4644 | stack, return a @code{mem} which refers to the frame pointer. If\n\ |
4645 | @var{incoming} is @code{2}, the result is being used to fetch the\n\ |
4646 | structure value address at the beginning of a function. If you need\n\ |
4647 | to emit adjusting code, you should do it at this point." , |
4648 | rtx, (tree fndecl, int incoming), |
4649 | hook_rtx_tree_int_null) |
4650 | |
4651 | DEFHOOKPOD |
4652 | (omit_struct_return_reg, |
4653 | "Normally, when a function returns a structure by memory, the address\n\ |
4654 | is passed as an invisible pointer argument, but the compiler also\n\ |
4655 | arranges to return the address from the function like it would a normal\n\ |
4656 | pointer return value. Define this to true if that behavior is\n\ |
4657 | undesirable on your target." , |
4658 | bool, false) |
4659 | |
4660 | DEFHOOK |
4661 | (return_in_memory, |
4662 | "This target hook should return a nonzero value to say to return the\n\ |
4663 | function value in memory, just as large structures are always returned.\n\ |
4664 | Here @var{type} will be the data type of the value, and @var{fntype}\n\ |
4665 | will be the type of the function doing the returning, or @code{NULL} for\n\ |
4666 | libcalls.\n\ |
4667 | \n\ |
4668 | Note that values of mode @code{BLKmode} must be explicitly handled\n\ |
4669 | by this function. Also, the option @option{-fpcc-struct-return}\n\ |
4670 | takes effect regardless of this macro. On most systems, it is\n\ |
4671 | possible to leave the hook undefined; this causes a default\n\ |
4672 | definition to be used, whose value is the constant 1 for @code{BLKmode}\n\ |
4673 | values, and 0 otherwise.\n\ |
4674 | \n\ |
4675 | Do not use this hook to indicate that structures and unions should always\n\ |
4676 | be returned in memory. You should instead use @code{DEFAULT_PCC_STRUCT_RETURN}\n\ |
4677 | to indicate this." , |
4678 | bool, (const_tree type, const_tree fntype), |
4679 | default_return_in_memory) |
4680 | |
4681 | DEFHOOK |
4682 | (return_in_msb, |
4683 | "This hook should return true if values of type @var{type} are returned\n\ |
4684 | at the most significant end of a register (in other words, if they are\n\ |
4685 | padded at the least significant end). You can assume that @var{type}\n\ |
4686 | is returned in a register; the caller is required to check this.\n\ |
4687 | \n\ |
4688 | Note that the register provided by @code{TARGET_FUNCTION_VALUE} must\n\ |
4689 | be able to hold the complete return value. For example, if a 1-, 2-\n\ |
4690 | or 3-byte structure is returned at the most significant end of a\n\ |
4691 | 4-byte register, @code{TARGET_FUNCTION_VALUE} should provide an\n\ |
4692 | @code{SImode} rtx." , |
4693 | bool, (const_tree type), |
4694 | hook_bool_const_tree_false) |
4695 | |
4696 | /* Return true if a parameter must be passed by reference. TYPE may |
4697 | be null if this is a libcall. CA may be null if this query is |
4698 | from __builtin_va_arg. */ |
4699 | DEFHOOK |
4700 | (pass_by_reference, |
4701 | "This target hook should return @code{true} if argument @var{arg} at the\n\ |
4702 | position indicated by @var{cum} should be passed by reference. This\n\ |
4703 | predicate is queried after target independent reasons for being\n\ |
4704 | passed by reference, such as @code{TREE_ADDRESSABLE (@var{arg}.type)}.\n\ |
4705 | \n\ |
4706 | If the hook returns true, a copy of that argument is made in memory and a\n\ |
4707 | pointer to the argument is passed instead of the argument itself.\n\ |
4708 | The pointer is passed in whatever way is appropriate for passing a pointer\n\ |
4709 | to that type." , |
4710 | bool, |
4711 | (cumulative_args_t cum, const function_arg_info &arg), |
4712 | hook_bool_CUMULATIVE_ARGS_arg_info_false) |
4713 | |
4714 | DEFHOOK |
4715 | (expand_builtin_saveregs, |
4716 | "If defined, this hook produces the machine-specific code for a call to\n\ |
4717 | @code{__builtin_saveregs}. This code will be moved to the very\n\ |
4718 | beginning of the function, before any parameter access are made. The\n\ |
4719 | return value of this function should be an RTX that contains the value\n\ |
4720 | to use as the return of @code{__builtin_saveregs}." , |
4721 | rtx, (void), |
4722 | default_expand_builtin_saveregs) |
4723 | |
4724 | /* Returns pretend_argument_size. */ |
4725 | DEFHOOK |
4726 | (setup_incoming_varargs, |
4727 | "This target hook offers an alternative to using\n\ |
4728 | @code{__builtin_saveregs} and defining the hook\n\ |
4729 | @code{TARGET_EXPAND_BUILTIN_SAVEREGS}. Use it to store the anonymous\n\ |
4730 | register arguments into the stack so that all the arguments appear to\n\ |
4731 | have been passed consecutively on the stack. Once this is done, you can\n\ |
4732 | use the standard implementation of varargs that works for machines that\n\ |
4733 | pass all their arguments on the stack.\n\ |
4734 | \n\ |
4735 | The argument @var{args_so_far} points to the @code{CUMULATIVE_ARGS} data\n\ |
4736 | structure, containing the values that are obtained after processing the\n\ |
4737 | named arguments. The argument @var{arg} describes the last of these named\n\ |
4738 | arguments. The argument @var{arg} should not be used if the function type\n\ |
4739 | satisfies @code{TYPE_NO_NAMED_ARGS_STDARG_P}, since in that case there are\n\ |
4740 | no named arguments and all arguments are accessed with @code{va_arg}.\n\ |
4741 | \n\ |
4742 | The target hook should do two things: first, push onto the stack all the\n\ |
4743 | argument registers @emph{not} used for the named arguments, and second,\n\ |
4744 | store the size of the data thus pushed into the @code{int}-valued\n\ |
4745 | variable pointed to by @var{pretend_args_size}. The value that you\n\ |
4746 | store here will serve as additional offset for setting up the stack\n\ |
4747 | frame.\n\ |
4748 | \n\ |
4749 | Because you must generate code to push the anonymous arguments at\n\ |
4750 | compile time without knowing their data types,\n\ |
4751 | @code{TARGET_SETUP_INCOMING_VARARGS} is only useful on machines that\n\ |
4752 | have just a single category of argument register and use it uniformly\n\ |
4753 | for all data types.\n\ |
4754 | \n\ |
4755 | If the argument @var{second_time} is nonzero, it means that the\n\ |
4756 | arguments of the function are being analyzed for the second time. This\n\ |
4757 | happens for an inline function, which is not actually compiled until the\n\ |
4758 | end of the source file. The hook @code{TARGET_SETUP_INCOMING_VARARGS} should\n\ |
4759 | not generate any instructions in this case." , |
4760 | void, (cumulative_args_t args_so_far, const function_arg_info &arg, |
4761 | int *pretend_args_size, int second_time), |
4762 | default_setup_incoming_varargs) |
4763 | |
4764 | DEFHOOK |
4765 | (call_args, |
4766 | "While generating RTL for a function call, this target hook is invoked once\n\ |
4767 | for each argument passed to the function, either a register returned by\n\ |
4768 | @code{TARGET_FUNCTION_ARG} or a memory location. It is called just\n\ |
4769 | before the point where argument registers are stored. The type of the\n\ |
4770 | function to be called is also passed as the second argument; it is\n\ |
4771 | @code{NULL_TREE} for libcalls. The @code{TARGET_END_CALL_ARGS} hook is\n\ |
4772 | invoked just after the code to copy the return reg has been emitted.\n\ |
4773 | This functionality can be used to perform special setup of call argument\n\ |
4774 | registers if a target needs it.\n\ |
4775 | For functions without arguments, the hook is called once with @code{pc_rtx}\n\ |
4776 | passed instead of an argument register.\n\ |
4777 | Most ports do not need to implement anything for this hook." , |
4778 | void, (rtx, tree), |
4779 | hook_void_rtx_tree) |
4780 | |
4781 | DEFHOOK |
4782 | (end_call_args, |
4783 | "This target hook is invoked while generating RTL for a function call,\n\ |
4784 | just after the point where the return reg is copied into a pseudo. It\n\ |
4785 | signals that all the call argument and return registers for the just\n\ |
4786 | emitted call are now no longer in use.\n\ |
4787 | Most ports do not need to implement anything for this hook." , |
4788 | void, (void), |
4789 | hook_void_void) |
4790 | |
4791 | DEFHOOK |
4792 | (push_argument, |
4793 | "This target hook returns @code{true} if push instructions will be\n\ |
4794 | used to pass outgoing arguments. When the push instruction usage is\n\ |
4795 | optional, @var{npush} is nonzero to indicate the number of bytes to\n\ |
4796 | push. Otherwise, @var{npush} is zero. If the target machine does not\n\ |
4797 | have a push instruction or push instruction should be avoided,\n\ |
4798 | @code{false} should be returned. That directs GCC to use an alternate\n\ |
4799 | strategy: to allocate the entire argument block and then store the\n\ |
4800 | arguments into it. If this target hook may return @code{true},\n\ |
4801 | @code{PUSH_ROUNDING} must be defined." , |
4802 | bool, (unsigned int npush), |
4803 | default_push_argument) |
4804 | |
4805 | DEFHOOK |
4806 | (strict_argument_naming, |
4807 | "Define this hook to return @code{true} if the location where a function\n\ |
4808 | argument is passed depends on whether or not it is a named argument.\n\ |
4809 | \n\ |
4810 | This hook controls how the @var{named} argument to @code{TARGET_FUNCTION_ARG}\n\ |
4811 | is set for varargs and stdarg functions. If this hook returns\n\ |
4812 | @code{true}, the @var{named} argument is always true for named\n\ |
4813 | arguments, and false for unnamed arguments. If it returns @code{false},\n\ |
4814 | but @code{TARGET_PRETEND_OUTGOING_VARARGS_NAMED} returns @code{true},\n\ |
4815 | then all arguments are treated as named. Otherwise, all named arguments\n\ |
4816 | except the last are treated as named.\n\ |
4817 | \n\ |
4818 | You need not define this hook if it always returns @code{false}." , |
4819 | bool, (cumulative_args_t ca), |
4820 | hook_bool_CUMULATIVE_ARGS_false) |
4821 | |
4822 | /* Returns true if we should use |
4823 | targetm.calls.setup_incoming_varargs() and/or |
4824 | targetm.calls.strict_argument_naming(). */ |
4825 | DEFHOOK |
4826 | (pretend_outgoing_varargs_named, |
4827 | "If you need to conditionally change ABIs so that one works with\n\ |
4828 | @code{TARGET_SETUP_INCOMING_VARARGS}, but the other works like neither\n\ |
4829 | @code{TARGET_SETUP_INCOMING_VARARGS} nor @code{TARGET_STRICT_ARGUMENT_NAMING} was\n\ |
4830 | defined, then define this hook to return @code{true} if\n\ |
4831 | @code{TARGET_SETUP_INCOMING_VARARGS} is used, @code{false} otherwise.\n\ |
4832 | Otherwise, you should not define this hook." , |
4833 | bool, (cumulative_args_t ca), |
4834 | default_pretend_outgoing_varargs_named) |
4835 | |
4836 | /* Given a complex type T, return true if a parameter of type T |
4837 | should be passed as two scalars. */ |
4838 | DEFHOOK |
4839 | (split_complex_arg, |
4840 | "This hook should return true if parameter of type @var{type} are passed\n\ |
4841 | as two scalar parameters. By default, GCC will attempt to pack complex\n\ |
4842 | arguments into the target's word size. Some ABIs require complex arguments\n\ |
4843 | to be split and treated as their individual components. For example, on\n\ |
4844 | AIX64, complex floats should be passed in a pair of floating point\n\ |
4845 | registers, even though a complex float would fit in one 64-bit floating\n\ |
4846 | point register.\n\ |
4847 | \n\ |
4848 | The default value of this hook is @code{NULL}, which is treated as always\n\ |
4849 | false." , |
4850 | bool, (const_tree type), NULL) |
4851 | |
4852 | /* Return true if type T, mode MODE, may not be passed in registers, |
4853 | but must be passed on the stack. */ |
4854 | /* ??? This predicate should be applied strictly after pass-by-reference. |
4855 | Need audit to verify that this is the case. */ |
4856 | DEFHOOK |
4857 | (must_pass_in_stack, |
4858 | "This target hook should return @code{true} if we should not pass @var{arg}\n\ |
4859 | solely in registers. The file @file{expr.h} defines a\n\ |
4860 | definition that is usually appropriate, refer to @file{expr.h} for additional\n\ |
4861 | documentation." , |
4862 | bool, (const function_arg_info &arg), |
4863 | must_pass_in_stack_var_size_or_pad) |
4864 | |
4865 | /* Return true if type TYPE, mode MODE, which is passed by reference, |
4866 | should have the object copy generated by the callee rather than |
4867 | the caller. It is never called for TYPE requiring constructors. */ |
4868 | DEFHOOK |
4869 | (callee_copies, |
4870 | "The function argument described by the parameters to this hook is\n\ |
4871 | known to be passed by reference. The hook should return true if the\n\ |
4872 | function argument should be copied by the callee instead of copied\n\ |
4873 | by the caller.\n\ |
4874 | \n\ |
4875 | For any argument for which the hook returns true, if it can be\n\ |
4876 | determined that the argument is not modified, then a copy need\n\ |
4877 | not be generated.\n\ |
4878 | \n\ |
4879 | The default version of this hook always returns false." , |
4880 | bool, |
4881 | (cumulative_args_t cum, const function_arg_info &arg), |
4882 | hook_bool_CUMULATIVE_ARGS_arg_info_false) |
4883 | |
4884 | /* Return zero for arguments passed entirely on the stack or entirely |
4885 | in registers. If passed in both, return the number of bytes passed |
4886 | in registers; the balance is therefore passed on the stack. */ |
4887 | DEFHOOK |
4888 | (arg_partial_bytes, |
4889 | "This target hook returns the number of bytes at the beginning of an\n\ |
4890 | argument that must be put in registers. The value must be zero for\n\ |
4891 | arguments that are passed entirely in registers or that are entirely\n\ |
4892 | pushed on the stack.\n\ |
4893 | \n\ |
4894 | On some machines, certain arguments must be passed partially in\n\ |
4895 | registers and partially in memory. On these machines, typically the\n\ |
4896 | first few words of arguments are passed in registers, and the rest\n\ |
4897 | on the stack. If a multi-word argument (a @code{double} or a\n\ |
4898 | structure) crosses that boundary, its first few words must be passed\n\ |
4899 | in registers and the rest must be pushed. This macro tells the\n\ |
4900 | compiler when this occurs, and how many bytes should go in registers.\n\ |
4901 | \n\ |
4902 | @code{TARGET_FUNCTION_ARG} for these arguments should return the first\n\ |
4903 | register to be used by the caller for this argument; likewise\n\ |
4904 | @code{TARGET_FUNCTION_INCOMING_ARG}, for the called function." , |
4905 | int, (cumulative_args_t cum, const function_arg_info &arg), |
4906 | hook_int_CUMULATIVE_ARGS_arg_info_0) |
4907 | |
4908 | /* Update the state in CA to advance past an argument in the |
4909 | argument list. The values MODE, TYPE, and NAMED describe that |
4910 | argument. */ |
4911 | DEFHOOK |
4912 | (function_arg_advance, |
4913 | "This hook updates the summarizer variable pointed to by @var{ca} to\n\ |
4914 | advance past argument @var{arg} in the argument list. Once this is done,\n\ |
4915 | the variable @var{cum} is suitable for analyzing the @emph{following}\n\ |
4916 | argument with @code{TARGET_FUNCTION_ARG}, etc.\n\ |
4917 | \n\ |
4918 | This hook need not do anything if the argument in question was passed\n\ |
4919 | on the stack. The compiler knows how to track the amount of stack space\n\ |
4920 | used for arguments without any special help." , |
4921 | void, |
4922 | (cumulative_args_t ca, const function_arg_info &arg), |
4923 | default_function_arg_advance) |
4924 | |
4925 | DEFHOOK |
4926 | (function_arg_offset, |
4927 | "This hook returns the number of bytes to add to the offset of an\n\ |
4928 | argument of type @var{type} and mode @var{mode} when passed in memory.\n\ |
4929 | This is needed for the SPU, which passes @code{char} and @code{short}\n\ |
4930 | arguments in the preferred slot that is in the middle of the quad word\n\ |
4931 | instead of starting at the top. The default implementation returns 0." , |
4932 | HOST_WIDE_INT, (machine_mode mode, const_tree type), |
4933 | default_function_arg_offset) |
4934 | |
4935 | DEFHOOK |
4936 | (function_arg_padding, |
4937 | "This hook determines whether, and in which direction, to pad out\n\ |
4938 | an argument of mode @var{mode} and type @var{type}. It returns\n\ |
4939 | @code{PAD_UPWARD} to insert padding above the argument, @code{PAD_DOWNWARD}\n\ |
4940 | to insert padding below the argument, or @code{PAD_NONE} to inhibit padding.\n\ |
4941 | \n\ |
4942 | The @emph{amount} of padding is not controlled by this hook, but by\n\ |
4943 | @code{TARGET_FUNCTION_ARG_ROUND_BOUNDARY}. It is always just enough\n\ |
4944 | to reach the next multiple of that boundary.\n\ |
4945 | \n\ |
4946 | This hook has a default definition that is right for most systems.\n\ |
4947 | For little-endian machines, the default is to pad upward. For\n\ |
4948 | big-endian machines, the default is to pad downward for an argument of\n\ |
4949 | constant size shorter than an @code{int}, and upward otherwise." , |
4950 | pad_direction, (machine_mode mode, const_tree type), |
4951 | default_function_arg_padding) |
4952 | |
4953 | /* Return zero if the argument described by the state of CA should |
4954 | be placed on a stack, or a hard register in which to store the |
4955 | argument. The values MODE, TYPE, and NAMED describe that |
4956 | argument. */ |
4957 | DEFHOOK |
4958 | (function_arg, |
4959 | "Return an RTX indicating whether function argument @var{arg} is passed\n\ |
4960 | in a register and if so, which register. Argument @var{ca} summarizes all\n\ |
4961 | the previous arguments.\n\ |
4962 | \n\ |
4963 | The return value is usually either a @code{reg} RTX for the hard\n\ |
4964 | register in which to pass the argument, or zero to pass the argument\n\ |
4965 | on the stack.\n\ |
4966 | \n\ |
4967 | The value of the expression can also be a @code{parallel} RTX@. This is\n\ |
4968 | used when an argument is passed in multiple locations. The mode of the\n\ |
4969 | @code{parallel} should be the mode of the entire argument. The\n\ |
4970 | @code{parallel} holds any number of @code{expr_list} pairs; each one\n\ |
4971 | describes where part of the argument is passed. In each\n\ |
4972 | @code{expr_list} the first operand must be a @code{reg} RTX for the hard\n\ |
4973 | register in which to pass this part of the argument, and the mode of the\n\ |
4974 | register RTX indicates how large this part of the argument is. The\n\ |
4975 | second operand of the @code{expr_list} is a @code{const_int} which gives\n\ |
4976 | the offset in bytes into the entire argument of where this part starts.\n\ |
4977 | As a special exception the first @code{expr_list} in the @code{parallel}\n\ |
4978 | RTX may have a first operand of zero. This indicates that the entire\n\ |
4979 | argument is also stored on the stack.\n\ |
4980 | \n\ |
4981 | The last time this hook is called, it is called with @code{MODE ==\n\ |
4982 | VOIDmode}, and its result is passed to the @code{call} or @code{call_value}\n\ |
4983 | pattern as operands 2 and 3 respectively.\n\ |
4984 | \n\ |
4985 | @cindex @file{stdarg.h} and register arguments\n\ |
4986 | The usual way to make the ISO library @file{stdarg.h} work on a\n\ |
4987 | machine where some arguments are usually passed in registers, is to\n\ |
4988 | cause nameless arguments to be passed on the stack instead. This is\n\ |
4989 | done by making @code{TARGET_FUNCTION_ARG} return 0 whenever\n\ |
4990 | @var{named} is @code{false}.\n\ |
4991 | \n\ |
4992 | @cindex @code{TARGET_MUST_PASS_IN_STACK}, and @code{TARGET_FUNCTION_ARG}\n\ |
4993 | @cindex @code{REG_PARM_STACK_SPACE}, and @code{TARGET_FUNCTION_ARG}\n\ |
4994 | You may use the hook @code{targetm.calls.must_pass_in_stack}\n\ |
4995 | in the definition of this macro to determine if this argument is of a\n\ |
4996 | type that must be passed in the stack. If @code{REG_PARM_STACK_SPACE}\n\ |
4997 | is not defined and @code{TARGET_FUNCTION_ARG} returns nonzero for such an\n\ |
4998 | argument, the compiler will abort. If @code{REG_PARM_STACK_SPACE} is\n\ |
4999 | defined, the argument will be computed in the stack and then loaded into\n\ |
5000 | a register." , |
5001 | rtx, (cumulative_args_t ca, const function_arg_info &arg), |
5002 | default_function_arg) |
5003 | |
5004 | DEFHOOK |
5005 | (function_incoming_arg, |
5006 | "Define this hook if the caller and callee on the target have different\n\ |
5007 | views of where arguments are passed. Also define this hook if there are\n\ |
5008 | functions that are never directly called, but are invoked by the hardware\n\ |
5009 | and which have nonstandard calling conventions.\n\ |
5010 | \n\ |
5011 | In this case @code{TARGET_FUNCTION_ARG} computes the register in\n\ |
5012 | which the caller passes the value, and\n\ |
5013 | @code{TARGET_FUNCTION_INCOMING_ARG} should be defined in a similar\n\ |
5014 | fashion to tell the function being called where the arguments will\n\ |
5015 | arrive.\n\ |
5016 | \n\ |
5017 | @code{TARGET_FUNCTION_INCOMING_ARG} can also return arbitrary address\n\ |
5018 | computation using hard register, which can be forced into a register,\n\ |
5019 | so that it can be used to pass special arguments.\n\ |
5020 | \n\ |
5021 | If @code{TARGET_FUNCTION_INCOMING_ARG} is not defined,\n\ |
5022 | @code{TARGET_FUNCTION_ARG} serves both purposes." , |
5023 | rtx, (cumulative_args_t ca, const function_arg_info &arg), |
5024 | default_function_incoming_arg) |
5025 | |
5026 | DEFHOOK |
5027 | (function_arg_boundary, |
5028 | "This hook returns the alignment boundary, in bits, of an argument\n\ |
5029 | with the specified mode and type. The default hook returns\n\ |
5030 | @code{PARM_BOUNDARY} for all arguments." , |
5031 | unsigned int, (machine_mode mode, const_tree type), |
5032 | default_function_arg_boundary) |
5033 | |
5034 | DEFHOOK |
5035 | (function_arg_round_boundary, |
5036 | "Normally, the size of an argument is rounded up to @code{PARM_BOUNDARY},\n\ |
5037 | which is the default value for this hook. You can define this hook to\n\ |
5038 | return a different value if an argument size must be rounded to a larger\n\ |
5039 | value." , |
5040 | unsigned int, (machine_mode mode, const_tree type), |
5041 | default_function_arg_round_boundary) |
5042 | |
5043 | /* Return the diagnostic message string if function without a prototype |
5044 | is not allowed for this 'val' argument; NULL otherwise. */ |
5045 | DEFHOOK |
5046 | (invalid_arg_for_unprototyped_fn, |
5047 | "If defined, this macro returns the diagnostic message when it is\n\ |
5048 | illegal to pass argument @var{val} to function @var{funcdecl}\n\ |
5049 | with prototype @var{typelist}." , |
5050 | const char *, (const_tree typelist, const_tree funcdecl, const_tree val), |
5051 | hook_invalid_arg_for_unprototyped_fn) |
5052 | |
5053 | /* Return an rtx for the return value location of the function |
5054 | specified by FN_DECL_OR_TYPE with a return type of RET_TYPE. */ |
5055 | DEFHOOK |
5056 | (function_value, |
5057 | "\n\ |
5058 | Define this to return an RTX representing the place where a function\n\ |
5059 | returns or receives a value of data type @var{ret_type}, a tree node\n\ |
5060 | representing a data type. @var{fn_decl_or_type} is a tree node\n\ |
5061 | representing @code{FUNCTION_DECL} or @code{FUNCTION_TYPE} of a\n\ |
5062 | function being called. If @var{outgoing} is false, the hook should\n\ |
5063 | compute the register in which the caller will see the return value.\n\ |
5064 | Otherwise, the hook should return an RTX representing the place where\n\ |
5065 | a function returns a value.\n\ |
5066 | \n\ |
5067 | On many machines, only @code{TYPE_MODE (@var{ret_type})} is relevant.\n\ |
5068 | (Actually, on most machines, scalar values are returned in the same\n\ |
5069 | place regardless of mode.) The value of the expression is usually a\n\ |
5070 | @code{reg} RTX for the hard register where the return value is stored.\n\ |
5071 | The value can also be a @code{parallel} RTX, if the return value is in\n\ |
5072 | multiple places. See @code{TARGET_FUNCTION_ARG} for an explanation of the\n\ |
5073 | @code{parallel} form. Note that the callee will populate every\n\ |
5074 | location specified in the @code{parallel}, but if the first element of\n\ |
5075 | the @code{parallel} contains the whole return value, callers will use\n\ |
5076 | that element as the canonical location and ignore the others. The m68k\n\ |
5077 | port uses this type of @code{parallel} to return pointers in both\n\ |
5078 | @samp{%a0} (the canonical location) and @samp{%d0}.\n\ |
5079 | \n\ |
5080 | If @code{TARGET_PROMOTE_FUNCTION_RETURN} returns true, you must apply\n\ |
5081 | the same promotion rules specified in @code{PROMOTE_MODE} if\n\ |
5082 | @var{valtype} is a scalar type.\n\ |
5083 | \n\ |
5084 | If the precise function being called is known, @var{func} is a tree\n\ |
5085 | node (@code{FUNCTION_DECL}) for it; otherwise, @var{func} is a null\n\ |
5086 | pointer. This makes it possible to use a different value-returning\n\ |
5087 | convention for specific functions when all their calls are\n\ |
5088 | known.\n\ |
5089 | \n\ |
5090 | Some target machines have ``register windows'' so that the register in\n\ |
5091 | which a function returns its value is not the same as the one in which\n\ |
5092 | the caller sees the value. For such machines, you should return\n\ |
5093 | different RTX depending on @var{outgoing}.\n\ |
5094 | \n\ |
5095 | @code{TARGET_FUNCTION_VALUE} is not used for return values with\n\ |
5096 | aggregate data types, because these are returned in another way. See\n\ |
5097 | @code{TARGET_STRUCT_VALUE_RTX} and related macros, below." , |
5098 | rtx, (const_tree ret_type, const_tree fn_decl_or_type, bool outgoing), |
5099 | default_function_value) |
5100 | |
5101 | /* Return the rtx for the result of a libcall of mode MODE, |
5102 | calling the function FN_NAME. */ |
5103 | DEFHOOK |
5104 | (libcall_value, |
5105 | "Define this hook if the back-end needs to know the name of the libcall\n\ |
5106 | function in order to determine where the result should be returned.\n\ |
5107 | \n\ |
5108 | The mode of the result is given by @var{mode} and the name of the called\n\ |
5109 | library function is given by @var{fun}. The hook should return an RTX\n\ |
5110 | representing the place where the library function result will be returned.\n\ |
5111 | \n\ |
5112 | If this hook is not defined, then LIBCALL_VALUE will be used." , |
5113 | rtx, (machine_mode mode, const_rtx fun), |
5114 | default_libcall_value) |
5115 | |
5116 | /* Return true if REGNO is a possible register number for |
5117 | a function value as seen by the caller. */ |
5118 | DEFHOOK |
5119 | (function_value_regno_p, |
5120 | "A target hook that return @code{true} if @var{regno} is the number of a hard\n\ |
5121 | register in which the values of called function may come back.\n\ |
5122 | \n\ |
5123 | A register whose use for returning values is limited to serving as the\n\ |
5124 | second of a pair (for a value of type @code{double}, say) need not be\n\ |
5125 | recognized by this target hook.\n\ |
5126 | \n\ |
5127 | If the machine has register windows, so that the caller and the called\n\ |
5128 | function use different registers for the return value, this target hook\n\ |
5129 | should recognize only the caller's register numbers.\n\ |
5130 | \n\ |
5131 | If this hook is not defined, then FUNCTION_VALUE_REGNO_P will be used." , |
5132 | bool, (const unsigned int regno), |
5133 | default_function_value_regno_p) |
5134 | |
5135 | DEFHOOK |
5136 | (fntype_abi, |
5137 | "Return the ABI used by a function with type @var{type}; see the\n\ |
5138 | definition of @code{predefined_function_abi} for details of the ABI\n\ |
5139 | descriptor. Targets only need to define this hook if they support\n\ |
5140 | interoperability between several ABIs in the same translation unit." , |
5141 | const predefined_function_abi &, (const_tree type), |
5142 | NULL) |
5143 | |
5144 | DEFHOOK |
5145 | (insn_callee_abi, |
5146 | "This hook returns a description of the ABI used by the target of\n\ |
5147 | call instruction @var{insn}; see the definition of\n\ |
5148 | @code{predefined_function_abi} for details of the ABI descriptor.\n\ |
5149 | Only the global function @code{insn_callee_abi} should call this hook\n\ |
5150 | directly.\n\ |
5151 | \n\ |
5152 | Targets only need to define this hook if they support\n\ |
5153 | interoperability between several ABIs in the same translation unit." , |
5154 | const predefined_function_abi &, (const rtx_insn *insn), |
5155 | NULL) |
5156 | |
5157 | /* ??? Documenting this hook requires a GFDL license grant. */ |
5158 | DEFHOOK_UNDOC |
5159 | (internal_arg_pointer, |
5160 | "Return an rtx for the argument pointer incoming to the\ |
5161 | current function." , |
5162 | rtx, (void), |
5163 | default_internal_arg_pointer) |
5164 | |
5165 | /* Update the current function stack boundary if needed. */ |
5166 | DEFHOOK |
5167 | (update_stack_boundary, |
5168 | "Define this macro to update the current function stack boundary if\n\ |
5169 | necessary." , |
5170 | void, (void), NULL) |
5171 | |
5172 | /* Handle stack alignment and return an rtx for Dynamic Realign |
5173 | Argument Pointer if necessary. */ |
5174 | DEFHOOK |
5175 | (get_drap_rtx, |
5176 | "This hook should return an rtx for Dynamic Realign Argument Pointer (DRAP) if a\n\ |
5177 | different argument pointer register is needed to access the function's\n\ |
5178 | argument list due to stack realignment. Return @code{NULL} if no DRAP\n\ |
5179 | is needed." , |
5180 | rtx, (void), NULL) |
5181 | |
5182 | /* Generate instruction sequence to zero call used registers. */ |
5183 | DEFHOOK |
5184 | (zero_call_used_regs, |
5185 | "This target hook emits instructions to zero the subset of @var{selected_regs}\n\ |
5186 | that could conceivably contain values that are useful to an attacker.\n\ |
5187 | Return the set of registers that were actually cleared.\n\ |
5188 | \n\ |
5189 | For most targets, the returned set of registers is a subset of\n\ |
5190 | @var{selected_regs}, however, for some of the targets (for example MIPS),\n\ |
5191 | clearing some registers that are in the @var{selected_regs} requires\n\ |
5192 | clearing other call used registers that are not in the @var{selected_regs},\n\ |
5193 | under such situation, the returned set of registers must be a subset of all\n\ |
5194 | call used registers.\n\ |
5195 | \n\ |
5196 | The default implementation uses normal move instructions to zero\n\ |
5197 | all the registers in @var{selected_regs}. Define this hook if the\n\ |
5198 | target has more efficient ways of zeroing certain registers,\n\ |
5199 | or if you believe that certain registers would never contain\n\ |
5200 | values that are useful to an attacker." , |
5201 | HARD_REG_SET, (HARD_REG_SET selected_regs), |
5202 | default_zero_call_used_regs) |
5203 | |
5204 | /* Return true if all function parameters should be spilled to the |
5205 | stack. */ |
5206 | DEFHOOK |
5207 | (allocate_stack_slots_for_args, |
5208 | "When optimization is disabled, this hook indicates whether or not\n\ |
5209 | arguments should be allocated to stack slots. Normally, GCC allocates\n\ |
5210 | stacks slots for arguments when not optimizing in order to make\n\ |
5211 | debugging easier. However, when a function is declared with\n\ |
5212 | @code{__attribute__((naked))}, there is no stack frame, and the compiler\n\ |
5213 | cannot safely move arguments from the registers in which they are passed\n\ |
5214 | to the stack. Therefore, this hook should return true in general, but\n\ |
5215 | false for naked functions. The default implementation always returns true." , |
5216 | bool, (void), |
5217 | hook_bool_void_true) |
5218 | |
5219 | /* Return an rtx for the static chain for FNDECL_OR_TYPE. If INCOMING_P |
5220 | is true, then it should be for the callee; otherwise for the caller. */ |
5221 | DEFHOOK |
5222 | (static_chain, |
5223 | "This hook replaces the use of @code{STATIC_CHAIN_REGNUM} et al for\n\ |
5224 | targets that may use different static chain locations for different\n\ |
5225 | nested functions. This may be required if the target has function\n\ |
5226 | attributes that affect the calling conventions of the function and\n\ |
5227 | those calling conventions use different static chain locations.\n\ |
5228 | \n\ |
5229 | The default version of this hook uses @code{STATIC_CHAIN_REGNUM} et al.\n\ |
5230 | \n\ |
5231 | If the static chain is passed in memory, this hook should be used to\n\ |
5232 | provide rtx giving @code{mem} expressions that denote where they are stored.\n\ |
5233 | Often the @code{mem} expression as seen by the caller will be at an offset\n\ |
5234 | from the stack pointer and the @code{mem} expression as seen by the callee\n\ |
5235 | will be at an offset from the frame pointer.\n\ |
5236 | @findex stack_pointer_rtx\n\ |
5237 | @findex frame_pointer_rtx\n\ |
5238 | @findex arg_pointer_rtx\n\ |
5239 | The variables @code{stack_pointer_rtx}, @code{frame_pointer_rtx}, and\n\ |
5240 | @code{arg_pointer_rtx} will have been initialized and should be used\n\ |
5241 | to refer to those items." , |
5242 | rtx, (const_tree fndecl_or_type, bool incoming_p), |
5243 | default_static_chain) |
5244 | |
5245 | /* Fill in the trampoline at MEM with a call to FNDECL and a |
5246 | static chain value of CHAIN. */ |
5247 | DEFHOOK |
5248 | (trampoline_init, |
5249 | "This hook is called to initialize a trampoline.\n\ |
5250 | @var{m_tramp} is an RTX for the memory block for the trampoline; @var{fndecl}\n\ |
5251 | is the @code{FUNCTION_DECL} for the nested function; @var{static_chain} is an\n\ |
5252 | RTX for the static chain value that should be passed to the function\n\ |
5253 | when it is called.\n\ |
5254 | \n\ |
5255 | If the target defines @code{TARGET_ASM_TRAMPOLINE_TEMPLATE}, then the\n\ |
5256 | first thing this hook should do is emit a block move into @var{m_tramp}\n\ |
5257 | from the memory block returned by @code{assemble_trampoline_template}.\n\ |
5258 | Note that the block move need only cover the constant parts of the\n\ |
5259 | trampoline. If the target isolates the variable parts of the trampoline\n\ |
5260 | to the end, not all @code{TRAMPOLINE_SIZE} bytes need be copied.\n\ |
5261 | \n\ |
5262 | If the target requires any other actions, such as flushing caches\n\ |
5263 | (possibly calling function maybe_emit_call_builtin___clear_cache) or\n\ |
5264 | enabling stack execution, these actions should be performed after\n\ |
5265 | initializing the trampoline proper." , |
5266 | void, (rtx m_tramp, tree fndecl, rtx static_chain), |
5267 | default_trampoline_init) |
5268 | |
5269 | /* Emit a call to a function to clear the instruction cache. */ |
5270 | DEFHOOK |
5271 | (emit_call_builtin___clear_cache, |
5272 | "On targets that do not define a @code{clear_cache} insn expander,\n\ |
5273 | but that define the @code{CLEAR_CACHE_INSN} macro,\n\ |
5274 | maybe_emit_call_builtin___clear_cache relies on this target hook\n\ |
5275 | to clear an address range in the instruction cache.\n\ |
5276 | \n\ |
5277 | The default implementation calls the @code{__clear_cache} builtin,\n\ |
5278 | taking the assembler name from the builtin declaration. Overriding\n\ |
5279 | definitions may call alternate functions, with alternate calling\n\ |
5280 | conventions, or emit alternate RTX to perform the job." , |
5281 | void, (rtx begin, rtx end), |
5282 | default_emit_call_builtin___clear_cache) |
5283 | |
5284 | /* Adjust the address of the trampoline in a target-specific way. */ |
5285 | DEFHOOK |
5286 | (trampoline_adjust_address, |
5287 | "This hook should perform any machine-specific adjustment in\n\ |
5288 | the address of the trampoline. Its argument contains the address of the\n\ |
5289 | memory block that was passed to @code{TARGET_TRAMPOLINE_INIT}. In case\n\ |
5290 | the address to be used for a function call should be different from the\n\ |
5291 | address at which the template was stored, the different address should\n\ |
5292 | be returned; otherwise @var{addr} should be returned unchanged.\n\ |
5293 | If this hook is not defined, @var{addr} will be used for function calls." , |
5294 | rtx, (rtx addr), NULL) |
5295 | |
5296 | DEFHOOKPOD |
5297 | (custom_function_descriptors, |
5298 | "If the target can use GCC's generic descriptor mechanism for nested\n\ |
5299 | functions, define this hook to a power of 2 representing an unused bit\n\ |
5300 | in function pointers which can be used to differentiate descriptors at\n\ |
5301 | run time. This value gives the number of bytes by which descriptor\n\ |
5302 | pointers are misaligned compared to function pointers. For example, on\n\ |
5303 | targets that require functions to be aligned to a 4-byte boundary, a\n\ |
5304 | value of either 1 or 2 is appropriate unless the architecture already\n\ |
5305 | reserves the bit for another purpose, such as on ARM.\n\ |
5306 | \n\ |
5307 | Define this hook to 0 if the target implements ABI support for\n\ |
5308 | function descriptors in its standard calling sequence, like for example\n\ |
5309 | HPPA or IA-64.\n\ |
5310 | \n\ |
5311 | Using descriptors for nested functions\n\ |
5312 | eliminates the need for trampolines that reside on the stack and require\n\ |
5313 | it to be made executable." , |
5314 | int, -1) |
5315 | |
5316 | /* Return the number of bytes of its own arguments that a function |
5317 | pops on returning, or 0 if the function pops no arguments and the |
5318 | caller must therefore pop them all after the function returns. */ |
5319 | /* ??? tm.texi has no types for the parameters. */ |
5320 | DEFHOOK |
5321 | (return_pops_args, |
5322 | "This target hook returns the number of bytes of its own arguments that\n\ |
5323 | a function pops on returning, or 0 if the function pops no arguments\n\ |
5324 | and the caller must therefore pop them all after the function returns.\n\ |
5325 | \n\ |
5326 | @var{fundecl} is a C variable whose value is a tree node that describes\n\ |
5327 | the function in question. Normally it is a node of type\n\ |
5328 | @code{FUNCTION_DECL} that describes the declaration of the function.\n\ |
5329 | From this you can obtain the @code{DECL_ATTRIBUTES} of the function.\n\ |
5330 | \n\ |
5331 | @var{funtype} is a C variable whose value is a tree node that\n\ |
5332 | describes the function in question. Normally it is a node of type\n\ |
5333 | @code{FUNCTION_TYPE} that describes the data type of the function.\n\ |
5334 | From this it is possible to obtain the data types of the value and\n\ |
5335 | arguments (if known).\n\ |
5336 | \n\ |
5337 | When a call to a library function is being considered, @var{fundecl}\n\ |
5338 | will contain an identifier node for the library function. Thus, if\n\ |
5339 | you need to distinguish among various library functions, you can do so\n\ |
5340 | by their names. Note that ``library function'' in this context means\n\ |
5341 | a function used to perform arithmetic, whose name is known specially\n\ |
5342 | in the compiler and was not mentioned in the C code being compiled.\n\ |
5343 | \n\ |
5344 | @var{size} is the number of bytes of arguments passed on the\n\ |
5345 | stack. If a variable number of bytes is passed, it is zero, and\n\ |
5346 | argument popping will always be the responsibility of the calling function.\n\ |
5347 | \n\ |
5348 | On the VAX, all functions always pop their arguments, so the definition\n\ |
5349 | of this macro is @var{size}. On the 68000, using the standard\n\ |
5350 | calling convention, no functions pop their arguments, so the value of\n\ |
5351 | the macro is always 0 in this case. But an alternative calling\n\ |
5352 | convention is available in which functions that take a fixed number of\n\ |
5353 | arguments pop them but other functions (such as @code{printf}) pop\n\ |
5354 | nothing (the caller pops all). When this convention is in use,\n\ |
5355 | @var{funtype} is examined to determine whether a function takes a fixed\n\ |
5356 | number of arguments." , |
5357 | poly_int64, (tree fundecl, tree funtype, poly_int64 size), |
5358 | default_return_pops_args) |
5359 | |
5360 | /* Return a mode wide enough to copy any function value that might be |
5361 | returned. */ |
5362 | DEFHOOK |
5363 | (get_raw_result_mode, |
5364 | "This target hook returns the mode to be used when accessing raw return\n\ |
5365 | registers in @code{__builtin_return}. Define this macro if the value\n\ |
5366 | in @var{reg_raw_mode} is not correct. Use @code{VOIDmode} if a register\n\ |
5367 | should be ignored for @code{__builtin_return} purposes." , |
5368 | fixed_size_mode, (int regno), |
5369 | default_get_reg_raw_mode) |
5370 | |
5371 | /* Return a mode wide enough to copy any argument value that might be |
5372 | passed. */ |
5373 | DEFHOOK |
5374 | (get_raw_arg_mode, |
5375 | "This target hook returns the mode to be used when accessing raw argument\n\ |
5376 | registers in @code{__builtin_apply_args}. Define this macro if the value\n\ |
5377 | in @var{reg_raw_mode} is not correct. Use @code{VOIDmode} if a register\n\ |
5378 | should be ignored for @code{__builtin_apply_args} purposes." , |
5379 | fixed_size_mode, (int regno), |
5380 | default_get_reg_raw_mode) |
5381 | |
5382 | /* Return true if a type is an empty record. */ |
5383 | DEFHOOK |
5384 | (empty_record_p, |
5385 | "This target hook returns true if the type is an empty record. The default\n\ |
5386 | is to return @code{false}." , |
5387 | bool, (const_tree type), |
5388 | hook_bool_const_tree_false) |
5389 | |
5390 | /* Warn about the change in empty class parameter passing ABI. */ |
5391 | DEFHOOK |
5392 | (warn_parameter_passing_abi, |
5393 | "This target hook warns about the change in empty class parameter passing\n\ |
5394 | ABI." , |
5395 | void, (cumulative_args_t ca, tree type), |
5396 | hook_void_CUMULATIVE_ARGS_tree) |
5397 | |
5398 | HOOK_VECTOR_END (calls) |
5399 | |
5400 | DEFHOOK |
5401 | (use_pseudo_pic_reg, |
5402 | "This hook should return 1 in case pseudo register should be created\n\ |
5403 | for pic_offset_table_rtx during function expand." , |
5404 | bool, (void), |
5405 | hook_bool_void_false) |
5406 | |
5407 | DEFHOOK |
5408 | (init_pic_reg, |
5409 | "Perform a target dependent initialization of pic_offset_table_rtx.\n\ |
5410 | This hook is called at the start of register allocation." , |
5411 | void, (void), |
5412 | hook_void_void) |
5413 | |
5414 | /* Return the diagnostic message string if conversion from FROMTYPE |
5415 | to TOTYPE is not allowed, NULL otherwise. */ |
5416 | DEFHOOK |
5417 | (invalid_conversion, |
5418 | "If defined, this macro returns the diagnostic message when it is\n\ |
5419 | invalid to convert from @var{fromtype} to @var{totype}, or @code{NULL}\n\ |
5420 | if validity should be determined by the front end." , |
5421 | const char *, (const_tree fromtype, const_tree totype), |
5422 | hook_constcharptr_const_tree_const_tree_null) |
5423 | |
5424 | /* Return the diagnostic message string if the unary operation OP is |
5425 | not permitted on TYPE, NULL otherwise. */ |
5426 | DEFHOOK |
5427 | (invalid_unary_op, |
5428 | "If defined, this macro returns the diagnostic message when it is\n\ |
5429 | invalid to apply operation @var{op} (where unary plus is denoted by\n\ |
5430 | @code{CONVERT_EXPR}) to an operand of type @var{type}, or @code{NULL}\n\ |
5431 | if validity should be determined by the front end." , |
5432 | const char *, (int op, const_tree type), |
5433 | hook_constcharptr_int_const_tree_null) |
5434 | |
5435 | /* Return the diagnostic message string if the binary operation OP |
5436 | is not permitted on TYPE1 and TYPE2, NULL otherwise. */ |
5437 | DEFHOOK |
5438 | (invalid_binary_op, |
5439 | "If defined, this macro returns the diagnostic message when it is\n\ |
5440 | invalid to apply operation @var{op} to operands of types @var{type1}\n\ |
5441 | and @var{type2}, or @code{NULL} if validity should be determined by\n\ |
5442 | the front end." , |
5443 | const char *, (int op, const_tree type1, const_tree type2), |
5444 | hook_constcharptr_int_const_tree_const_tree_null) |
5445 | |
5446 | /* If values of TYPE are promoted to some other type when used in |
5447 | expressions (analogous to the integer promotions), return that type, |
5448 | or NULL_TREE otherwise. */ |
5449 | DEFHOOK |
5450 | (promoted_type, |
5451 | "If defined, this target hook returns the type to which values of\n\ |
5452 | @var{type} should be promoted when they appear in expressions,\n\ |
5453 | analogous to the integer promotions, or @code{NULL_TREE} to use the\n\ |
5454 | front end's normal promotion rules. This hook is useful when there are\n\ |
5455 | target-specific types with special promotion rules.\n\ |
5456 | This is currently used only by the C and C++ front ends." , |
5457 | tree, (const_tree type), |
5458 | hook_tree_const_tree_null) |
5459 | |
5460 | /* Convert EXPR to TYPE, if target-specific types with special conversion |
5461 | rules are involved. Return the converted expression, or NULL to apply |
5462 | the standard conversion rules. */ |
5463 | DEFHOOK |
5464 | (convert_to_type, |
5465 | "If defined, this hook returns the result of converting @var{expr} to\n\ |
5466 | @var{type}. It should return the converted expression,\n\ |
5467 | or @code{NULL_TREE} to apply the front end's normal conversion rules.\n\ |
5468 | This hook is useful when there are target-specific types with special\n\ |
5469 | conversion rules.\n\ |
5470 | This is currently used only by the C and C++ front ends." , |
5471 | tree, (tree type, tree expr), |
5472 | hook_tree_tree_tree_null) |
5473 | |
5474 | DEFHOOK |
5475 | (verify_type_context, |
5476 | "If defined, this hook returns false if there is a target-specific reason\n\ |
5477 | why type @var{type} cannot be used in the source language context described\n\ |
5478 | by @var{context}. When @var{silent_p} is false, the hook also reports an\n\ |
5479 | error against @var{loc} for invalid uses of @var{type}.\n\ |
5480 | \n\ |
5481 | Calls to this hook should be made through the global function\n\ |
5482 | @code{verify_type_context}, which makes the @var{silent_p} parameter\n\ |
5483 | default to false and also handles @code{error_mark_node}.\n\ |
5484 | \n\ |
5485 | The default implementation always returns true." , |
5486 | bool, (location_t loc, type_context_kind context, const_tree type, |
5487 | bool silent_p), |
5488 | NULL) |
5489 | |
5490 | DEFHOOK |
5491 | (can_change_mode_class, |
5492 | "This hook returns true if it is possible to bitcast values held in\n\ |
5493 | registers of class @var{rclass} from mode @var{from} to mode @var{to}\n\ |
5494 | and if doing so preserves the low-order bits that are common to both modes.\n\ |
5495 | The result is only meaningful if @var{rclass} has registers that can hold\n\ |
5496 | both @code{from} and @code{to}. The default implementation returns true.\n\ |
5497 | \n\ |
5498 | As an example of when such bitcasting is invalid, loading 32-bit integer or\n\ |
5499 | floating-point objects into floating-point registers on Alpha extends them\n\ |
5500 | to 64 bits. Therefore loading a 64-bit object and then storing it as a\n\ |
5501 | 32-bit object does not store the low-order 32 bits, as would be the case\n\ |
5502 | for a normal register. Therefore, @file{alpha.h} defines\n\ |
5503 | @code{TARGET_CAN_CHANGE_MODE_CLASS} to return:\n\ |
5504 | \n\ |
5505 | @smallexample\n\ |
5506 | (GET_MODE_SIZE (from) == GET_MODE_SIZE (to)\n\ |
5507 | || !reg_classes_intersect_p (FLOAT_REGS, rclass))\n\ |
5508 | @end smallexample\n\ |
5509 | \n\ |
5510 | Even if storing from a register in mode @var{to} would be valid,\n\ |
5511 | if both @var{from} and @code{raw_reg_mode} for @var{rclass} are wider\n\ |
5512 | than @code{word_mode}, then we must prevent @var{to} narrowing the\n\ |
5513 | mode. This happens when the middle-end assumes that it can load\n\ |
5514 | or store pieces of an @var{N}-word pseudo, and that the pseudo will\n\ |
5515 | eventually be allocated to @var{N} @code{word_mode} hard registers.\n\ |
5516 | Failure to prevent this kind of mode change will result in the\n\ |
5517 | entire @code{raw_reg_mode} being modified instead of the partial\n\ |
5518 | value that the middle-end intended." , |
5519 | bool, (machine_mode from, machine_mode to, reg_class_t rclass), |
5520 | hook_bool_mode_mode_reg_class_t_true) |
5521 | |
5522 | /* Change pseudo allocno class calculated by IRA. */ |
5523 | DEFHOOK |
5524 | (ira_change_pseudo_allocno_class, |
5525 | "A target hook which can change allocno class for given pseudo from\n\ |
5526 | allocno and best class calculated by IRA.\n\ |
5527 | \n\ |
5528 | The default version of this target hook always returns given class." , |
5529 | reg_class_t, (int, reg_class_t, reg_class_t), |
5530 | default_ira_change_pseudo_allocno_class) |
5531 | |
5532 | /* Return true if we use LRA instead of reload. */ |
5533 | DEFHOOK |
5534 | (lra_p, |
5535 | "A target hook which returns true if we use LRA instead of reload pass.\n\ |
5536 | \n\ |
5537 | The default version of this target hook returns true. New ports\n\ |
5538 | should use LRA, and existing ports are encouraged to convert." , |
5539 | bool, (void), |
5540 | default_lra_p) |
5541 | |
5542 | /* Return register priority of given hard regno for the current target. */ |
5543 | DEFHOOK |
5544 | (register_priority, |
5545 | "A target hook which returns the register priority number to which the\n\ |
5546 | register @var{hard_regno} belongs to. The bigger the number, the\n\ |
5547 | more preferable the hard register usage (when all other conditions are\n\ |
5548 | the same). This hook can be used to prefer some hard register over\n\ |
5549 | others in LRA. For example, some x86-64 register usage needs\n\ |
5550 | additional prefix which makes instructions longer. The hook can\n\ |
5551 | return lower priority number for such registers make them less favorable\n\ |
5552 | and as result making the generated code smaller.\n\ |
5553 | \n\ |
5554 | The default version of this target hook returns always zero." , |
5555 | int, (int), |
5556 | default_register_priority) |
5557 | |
5558 | /* Return true if we need register usage leveling. */ |
5559 | DEFHOOK |
5560 | (register_usage_leveling_p, |
5561 | "A target hook which returns true if we need register usage leveling.\n\ |
5562 | That means if a few hard registers are equally good for the\n\ |
5563 | assignment, we choose the least used hard register. The register\n\ |
5564 | usage leveling may be profitable for some targets. Don't use the\n\ |
5565 | usage leveling for targets with conditional execution or targets\n\ |
5566 | with big register files as it hurts if-conversion and cross-jumping\n\ |
5567 | optimizations.\n\ |
5568 | \n\ |
5569 | The default version of this target hook returns always false." , |
5570 | bool, (void), |
5571 | default_register_usage_leveling_p) |
5572 | |
5573 | /* Return true if maximal address displacement can be different. */ |
5574 | DEFHOOK |
5575 | (different_addr_displacement_p, |
5576 | "A target hook which returns true if an address with the same structure\n\ |
5577 | can have different maximal legitimate displacement. For example, the\n\ |
5578 | displacement can depend on memory mode or on operand combinations in\n\ |
5579 | the insn.\n\ |
5580 | \n\ |
5581 | The default version of this target hook returns always false." , |
5582 | bool, (void), |
5583 | default_different_addr_displacement_p) |
5584 | |
5585 | /* Determine class for spilling pseudos of given mode into registers |
5586 | instead of memory. */ |
5587 | DEFHOOK |
5588 | (spill_class, |
5589 | "This hook defines a class of registers which could be used for spilling\n\ |
5590 | pseudos of the given mode and class, or @code{NO_REGS} if only memory\n\ |
5591 | should be used. Not defining this hook is equivalent to returning\n\ |
5592 | @code{NO_REGS} for all inputs." , |
5593 | reg_class_t, (reg_class_t, machine_mode), |
5594 | NULL) |
5595 | |
5596 | /* Determine an additional allocno class. */ |
5597 | DEFHOOK |
5598 | (additional_allocno_class_p, |
5599 | "This hook should return @code{true} if given class of registers should\n\ |
5600 | be an allocno class in any way. Usually RA uses only one register\n\ |
5601 | class from all classes containing the same register set. In some\n\ |
5602 | complicated cases, you need to have two or more such classes as\n\ |
5603 | allocno ones for RA correct work. Not defining this hook is\n\ |
5604 | equivalent to returning @code{false} for all inputs." , |
5605 | bool, (reg_class_t), |
5606 | hook_bool_reg_class_t_false) |
5607 | |
5608 | DEFHOOK |
5609 | (cstore_mode, |
5610 | "This hook defines the machine mode to use for the boolean result of\n\ |
5611 | conditional store patterns. The ICODE argument is the instruction code\n\ |
5612 | for the cstore being performed. Not definiting this hook is the same\n\ |
5613 | as accepting the mode encoded into operand 0 of the cstore expander\n\ |
5614 | patterns." , |
5615 | scalar_int_mode, (enum insn_code icode), |
5616 | default_cstore_mode) |
5617 | |
5618 | /* This target hook allows the backend to compute the register pressure |
5619 | classes to use. */ |
5620 | DEFHOOK |
5621 | (compute_pressure_classes, |
5622 | "A target hook which lets a backend compute the set of pressure classes to\n\ |
5623 | be used by those optimization passes which take register pressure into\n\ |
5624 | account, as opposed to letting IRA compute them. It returns the number of\n\ |
5625 | register classes stored in the array @var{pressure_classes}." , |
5626 | int, (enum reg_class *pressure_classes), NULL) |
5627 | |
5628 | /* True if a structure, union or array with MODE containing FIELD should |
5629 | be accessed using BLKmode. */ |
5630 | DEFHOOK |
5631 | (member_type_forces_blk, |
5632 | "Return true if a structure, union or array containing @var{field} should\n\ |
5633 | be accessed using @code{BLKMODE}.\n\ |
5634 | \n\ |
5635 | If @var{field} is the only field in the structure, @var{mode} is its\n\ |
5636 | mode, otherwise @var{mode} is VOIDmode. @var{mode} is provided in the\n\ |
5637 | case where structures of one field would require the structure's mode to\n\ |
5638 | retain the field's mode.\n\ |
5639 | \n\ |
5640 | Normally, this is not needed." , |
5641 | bool, (const_tree field, machine_mode mode), |
5642 | default_member_type_forces_blk) |
5643 | |
5644 | /* See tree-ssa-math-opts.cc:divmod_candidate_p for conditions |
5645 | that gate the divod transform. */ |
5646 | DEFHOOK |
5647 | (expand_divmod_libfunc, |
5648 | "Define this hook for enabling divmod transform if the port does not have\n\ |
5649 | hardware divmod insn but defines target-specific divmod libfuncs." , |
5650 | void, (rtx libfunc, machine_mode mode, rtx op0, rtx op1, rtx *quot, rtx *rem), |
5651 | NULL) |
5652 | |
5653 | /* Return the class for a secondary reload, and fill in extra information. */ |
5654 | DEFHOOK |
5655 | (secondary_reload, |
5656 | "Many machines have some registers that cannot be copied directly to or\n\ |
5657 | from memory or even from other types of registers. An example is the\n\ |
5658 | @samp{MQ} register, which on most machines, can only be copied to or\n\ |
5659 | from general registers, but not memory. Below, we shall be using the\n\ |
5660 | term 'intermediate register' when a move operation cannot be performed\n\ |
5661 | directly, but has to be done by copying the source into the intermediate\n\ |
5662 | register first, and then copying the intermediate register to the\n\ |
5663 | destination. An intermediate register always has the same mode as\n\ |
5664 | source and destination. Since it holds the actual value being copied,\n\ |
5665 | reload might apply optimizations to re-use an intermediate register\n\ |
5666 | and eliding the copy from the source when it can determine that the\n\ |
5667 | intermediate register still holds the required value.\n\ |
5668 | \n\ |
5669 | Another kind of secondary reload is required on some machines which\n\ |
5670 | allow copying all registers to and from memory, but require a scratch\n\ |
5671 | register for stores to some memory locations (e.g., those with symbolic\n\ |
5672 | address on the RT, and those with certain symbolic address on the SPARC\n\ |
5673 | when compiling PIC)@. Scratch registers need not have the same mode\n\ |
5674 | as the value being copied, and usually hold a different value than\n\ |
5675 | that being copied. Special patterns in the md file are needed to\n\ |
5676 | describe how the copy is performed with the help of the scratch register;\n\ |
5677 | these patterns also describe the number, register class(es) and mode(s)\n\ |
5678 | of the scratch register(s).\n\ |
5679 | \n\ |
5680 | In some cases, both an intermediate and a scratch register are required.\n\ |
5681 | \n\ |
5682 | For input reloads, this target hook is called with nonzero @var{in_p},\n\ |
5683 | and @var{x} is an rtx that needs to be copied to a register of class\n\ |
5684 | @var{reload_class} in @var{reload_mode}. For output reloads, this target\n\ |
5685 | hook is called with zero @var{in_p}, and a register of class @var{reload_class}\n\ |
5686 | needs to be copied to rtx @var{x} in @var{reload_mode}.\n\ |
5687 | \n\ |
5688 | If copying a register of @var{reload_class} from/to @var{x} requires\n\ |
5689 | an intermediate register, the hook @code{secondary_reload} should\n\ |
5690 | return the register class required for this intermediate register.\n\ |
5691 | If no intermediate register is required, it should return NO_REGS.\n\ |
5692 | If more than one intermediate register is required, describe the one\n\ |
5693 | that is closest in the copy chain to the reload register.\n\ |
5694 | \n\ |
5695 | If scratch registers are needed, you also have to describe how to\n\ |
5696 | perform the copy from/to the reload register to/from this\n\ |
5697 | closest intermediate register. Or if no intermediate register is\n\ |
5698 | required, but still a scratch register is needed, describe the\n\ |
5699 | copy from/to the reload register to/from the reload operand @var{x}.\n\ |
5700 | \n\ |
5701 | You do this by setting @code{sri->icode} to the instruction code of a pattern\n\ |
5702 | in the md file which performs the move. Operands 0 and 1 are the output\n\ |
5703 | and input of this copy, respectively. Operands from operand 2 onward are\n\ |
5704 | for scratch operands. These scratch operands must have a mode, and a\n\ |
5705 | single-register-class\n\ |
5706 | @c [later: or memory]\n\ |
5707 | output constraint.\n\ |
5708 | \n\ |
5709 | When an intermediate register is used, the @code{secondary_reload}\n\ |
5710 | hook will be called again to determine how to copy the intermediate\n\ |
5711 | register to/from the reload operand @var{x}, so your hook must also\n\ |
5712 | have code to handle the register class of the intermediate operand.\n\ |
5713 | \n\ |
5714 | @c [For later: maybe we'll allow multi-alternative reload patterns -\n\ |
5715 | @c the port maintainer could name a mov<mode> pattern that has clobbers -\n\ |
5716 | @c and match the constraints of input and output to determine the required\n\ |
5717 | @c alternative. A restriction would be that constraints used to match\n\ |
5718 | @c against reloads registers would have to be written as register class\n\ |
5719 | @c constraints, or we need a new target macro / hook that tells us if an\n\ |
5720 | @c arbitrary constraint can match an unknown register of a given class.\n\ |
5721 | @c Such a macro / hook would also be useful in other places.]\n\ |
5722 | \n\ |
5723 | \n\ |
5724 | @var{x} might be a pseudo-register or a @code{subreg} of a\n\ |
5725 | pseudo-register, which could either be in a hard register or in memory.\n\ |
5726 | Use @code{true_regnum} to find out; it will return @minus{}1 if the pseudo is\n\ |
5727 | in memory and the hard register number if it is in a register.\n\ |
5728 | \n\ |
5729 | Scratch operands in memory (constraint @code{\"=m\"} / @code{\"=&m\"}) are\n\ |
5730 | currently not supported. For the time being, you will have to continue\n\ |
5731 | to use @code{TARGET_SECONDARY_MEMORY_NEEDED} for that purpose.\n\ |
5732 | \n\ |
5733 | @code{copy_cost} also uses this target hook to find out how values are\n\ |
5734 | copied. If you want it to include some extra cost for the need to allocate\n\ |
5735 | (a) scratch register(s), set @code{sri->extra_cost} to the additional cost.\n\ |
5736 | Or if two dependent moves are supposed to have a lower cost than the sum\n\ |
5737 | of the individual moves due to expected fortuitous scheduling and/or special\n\ |
5738 | forwarding logic, you can set @code{sri->extra_cost} to a negative amount." , |
5739 | reg_class_t, |
5740 | (bool in_p, rtx x, reg_class_t reload_class, machine_mode reload_mode, |
5741 | secondary_reload_info *sri), |
5742 | default_secondary_reload) |
5743 | |
5744 | DEFHOOK |
5745 | (secondary_memory_needed, |
5746 | "Certain machines have the property that some registers cannot be copied\n\ |
5747 | to some other registers without using memory. Define this hook on\n\ |
5748 | those machines to return true if objects of mode @var{m} in registers\n\ |
5749 | of @var{class1} can only be copied to registers of class @var{class2} by\n\ |
5750 | storing a register of @var{class1} into memory and loading that memory\n\ |
5751 | location into a register of @var{class2}. The default definition returns\n\ |
5752 | false for all inputs." , |
5753 | bool, (machine_mode mode, reg_class_t class1, reg_class_t class2), |
5754 | hook_bool_mode_reg_class_t_reg_class_t_false) |
5755 | |
5756 | DEFHOOK |
5757 | (secondary_memory_needed_mode, |
5758 | "If @code{TARGET_SECONDARY_MEMORY_NEEDED} tells the compiler to use memory\n\ |
5759 | when moving between two particular registers of mode @var{mode},\n\ |
5760 | this hook specifies the mode that the memory should have.\n\ |
5761 | \n\ |
5762 | The default depends on @code{TARGET_LRA_P}. Without LRA, the default\n\ |
5763 | is to use a word-sized mode for integral modes that are smaller than a\n\ |
5764 | a word. This is right thing to do on most machines because it ensures\n\ |
5765 | that all bits of the register are copied and prevents accesses to the\n\ |
5766 | registers in a narrower mode, which some machines prohibit for\n\ |
5767 | floating-point registers.\n\ |
5768 | \n\ |
5769 | However, this default behavior is not correct on some machines, such as\n\ |
5770 | the DEC Alpha, that store short integers in floating-point registers\n\ |
5771 | differently than in integer registers. On those machines, the default\n\ |
5772 | widening will not work correctly and you must define this hook to\n\ |
5773 | suppress that widening in some cases. See the file @file{alpha.cc} for\n\ |
5774 | details.\n\ |
5775 | \n\ |
5776 | With LRA, the default is to use @var{mode} unmodified." , |
5777 | machine_mode, (machine_mode mode), |
5778 | default_secondary_memory_needed_mode) |
5779 | |
5780 | /* Given an rtx X being reloaded into a reg required to be in class CLASS, |
5781 | return the class of reg to actually use. */ |
5782 | DEFHOOK |
5783 | (preferred_reload_class, |
5784 | "A target hook that places additional restrictions on the register class\n\ |
5785 | to use when it is necessary to copy value @var{x} into a register in class\n\ |
5786 | @var{rclass}. The value is a register class; perhaps @var{rclass}, or perhaps\n\ |
5787 | another, smaller class.\n\ |
5788 | \n\ |
5789 | The default version of this hook always returns value of @code{rclass} argument.\n\ |
5790 | \n\ |
5791 | Sometimes returning a more restrictive class makes better code. For\n\ |
5792 | example, on the 68000, when @var{x} is an integer constant that is in range\n\ |
5793 | for a @samp{moveq} instruction, the value of this macro is always\n\ |
5794 | @code{DATA_REGS} as long as @var{rclass} includes the data registers.\n\ |
5795 | Requiring a data register guarantees that a @samp{moveq} will be used.\n\ |
5796 | \n\ |
5797 | One case where @code{TARGET_PREFERRED_RELOAD_CLASS} must not return\n\ |
5798 | @var{rclass} is if @var{x} is a legitimate constant which cannot be\n\ |
5799 | loaded into some register class. By returning @code{NO_REGS} you can\n\ |
5800 | force @var{x} into a memory location. For example, rs6000 can load\n\ |
5801 | immediate values into general-purpose registers, but does not have an\n\ |
5802 | instruction for loading an immediate value into a floating-point\n\ |
5803 | register, so @code{TARGET_PREFERRED_RELOAD_CLASS} returns @code{NO_REGS} when\n\ |
5804 | @var{x} is a floating-point constant. If the constant can't be loaded\n\ |
5805 | into any kind of register, code generation will be better if\n\ |
5806 | @code{TARGET_LEGITIMATE_CONSTANT_P} makes the constant illegitimate instead\n\ |
5807 | of using @code{TARGET_PREFERRED_RELOAD_CLASS}.\n\ |
5808 | \n\ |
5809 | If an insn has pseudos in it after register allocation, reload will go\n\ |
5810 | through the alternatives and call repeatedly @code{TARGET_PREFERRED_RELOAD_CLASS}\n\ |
5811 | to find the best one. Returning @code{NO_REGS}, in this case, makes\n\ |
5812 | reload add a @code{!} in front of the constraint: the x86 back-end uses\n\ |
5813 | this feature to discourage usage of 387 registers when math is done in\n\ |
5814 | the SSE registers (and vice versa)." , |
5815 | reg_class_t, |
5816 | (rtx x, reg_class_t rclass), |
5817 | default_preferred_reload_class) |
5818 | |
5819 | /* Like TARGET_PREFERRED_RELOAD_CLASS, but for output reloads instead of |
5820 | input reloads. */ |
5821 | DEFHOOK |
5822 | (preferred_output_reload_class, |
5823 | "Like @code{TARGET_PREFERRED_RELOAD_CLASS}, but for output reloads instead of\n\ |
5824 | input reloads.\n\ |
5825 | \n\ |
5826 | The default version of this hook always returns value of @code{rclass}\n\ |
5827 | argument.\n\ |
5828 | \n\ |
5829 | You can also use @code{TARGET_PREFERRED_OUTPUT_RELOAD_CLASS} to discourage\n\ |
5830 | reload from using some alternatives, like @code{TARGET_PREFERRED_RELOAD_CLASS}." , |
5831 | reg_class_t, |
5832 | (rtx x, reg_class_t rclass), |
5833 | default_preferred_output_reload_class) |
5834 | |
5835 | DEFHOOK |
5836 | (select_early_remat_modes, |
5837 | "On some targets, certain modes cannot be held in registers around a\n\ |
5838 | standard ABI call and are relatively expensive to spill to the stack.\n\ |
5839 | The early rematerialization pass can help in such cases by aggressively\n\ |
5840 | recomputing values after calls, so that they don't need to be spilled.\n\ |
5841 | \n\ |
5842 | This hook returns the set of such modes by setting the associated bits\n\ |
5843 | in @var{modes}. The default implementation selects no modes, which has\n\ |
5844 | the effect of disabling the early rematerialization pass." , |
5845 | void, (sbitmap modes), |
5846 | default_select_early_remat_modes) |
5847 | |
5848 | DEFHOOK |
5849 | (class_likely_spilled_p, |
5850 | "A target hook which returns @code{true} if pseudos that have been assigned\n\ |
5851 | to registers of class @var{rclass} would likely be spilled because\n\ |
5852 | registers of @var{rclass} are needed for spill registers.\n\ |
5853 | \n\ |
5854 | The default version of this target hook returns @code{true} if @var{rclass}\n\ |
5855 | has exactly one register and @code{false} otherwise. On most machines, this\n\ |
5856 | default should be used. For generally register-starved machines, such as\n\ |
5857 | i386, or machines with right register constraints, such as SH, this hook\n\ |
5858 | can be used to avoid excessive spilling.\n\ |
5859 | \n\ |
5860 | This hook is also used by some of the global intra-procedural code\n\ |
5861 | transformations to throtle code motion, to avoid increasing register\n\ |
5862 | pressure." , |
5863 | bool, (reg_class_t rclass), |
5864 | default_class_likely_spilled_p) |
5865 | |
5866 | /* Return the maximum number of consecutive registers |
5867 | needed to represent mode MODE in a register of class RCLASS. */ |
5868 | DEFHOOK |
5869 | (class_max_nregs, |
5870 | "A target hook returns the maximum number of consecutive registers\n\ |
5871 | of class @var{rclass} needed to hold a value of mode @var{mode}.\n\ |
5872 | \n\ |
5873 | This is closely related to the macro @code{TARGET_HARD_REGNO_NREGS}.\n\ |
5874 | In fact, the value returned by @code{TARGET_CLASS_MAX_NREGS (@var{rclass},\n\ |
5875 | @var{mode})} target hook should be the maximum value of\n\ |
5876 | @code{TARGET_HARD_REGNO_NREGS (@var{regno}, @var{mode})} for all @var{regno}\n\ |
5877 | values in the class @var{rclass}.\n\ |
5878 | \n\ |
5879 | This target hook helps control the handling of multiple-word values\n\ |
5880 | in the reload pass.\n\ |
5881 | \n\ |
5882 | The default version of this target hook returns the size of @var{mode}\n\ |
5883 | in words." , |
5884 | unsigned char, (reg_class_t rclass, machine_mode mode), |
5885 | default_class_max_nregs) |
5886 | |
5887 | DEFHOOK |
5888 | (preferred_rename_class, |
5889 | "A target hook that places additional preference on the register\n\ |
5890 | class to use when it is necessary to rename a register in class\n\ |
5891 | @var{rclass} to another class, or perhaps @var{NO_REGS}, if no\n\ |
5892 | preferred register class is found or hook @code{preferred_rename_class}\n\ |
5893 | is not implemented.\n\ |
5894 | Sometimes returning a more restrictive class makes better code. For\n\ |
5895 | example, on ARM, thumb-2 instructions using @code{LO_REGS} may be\n\ |
5896 | smaller than instructions using @code{GENERIC_REGS}. By returning\n\ |
5897 | @code{LO_REGS} from @code{preferred_rename_class}, code size can\n\ |
5898 | be reduced." , |
5899 | reg_class_t, (reg_class_t rclass), |
5900 | default_preferred_rename_class) |
5901 | |
5902 | /* This target hook allows the backend to avoid unsafe substitution |
5903 | during register allocation. */ |
5904 | DEFHOOK |
5905 | (cannot_substitute_mem_equiv_p, |
5906 | "A target hook which returns @code{true} if @var{subst} can't\n\ |
5907 | substitute safely pseudos with equivalent memory values during\n\ |
5908 | register allocation.\n\ |
5909 | The default version of this target hook returns @code{false}.\n\ |
5910 | On most machines, this default should be used. For generally\n\ |
5911 | machines with non orthogonal register usage for addressing, such\n\ |
5912 | as SH, this hook can be used to avoid excessive spilling." , |
5913 | bool, (rtx subst), |
5914 | hook_bool_rtx_false) |
5915 | |
5916 | /* This target hook allows the backend to legitimize base plus |
5917 | displacement addressing. */ |
5918 | DEFHOOK |
5919 | (legitimize_address_displacement, |
5920 | "This hook tries to split address offset @var{orig_offset} into\n\ |
5921 | two parts: one that should be added to the base address to create\n\ |
5922 | a local anchor point, and an additional offset that can be applied\n\ |
5923 | to the anchor to address a value of mode @var{mode}. The idea is that\n\ |
5924 | the local anchor could be shared by other accesses to nearby locations.\n\ |
5925 | \n\ |
5926 | The hook returns true if it succeeds, storing the offset of the\n\ |
5927 | anchor from the base in @var{offset1} and the offset of the final address\n\ |
5928 | from the anchor in @var{offset2}. The default implementation returns false." , |
5929 | bool, (rtx *offset1, rtx *offset2, poly_int64 orig_offset, machine_mode mode), |
5930 | default_legitimize_address_displacement) |
5931 | |
5932 | /* This target hook allows the backend to perform additional |
5933 | processing while initializing for variable expansion. */ |
5934 | DEFHOOK |
5935 | (expand_to_rtl_hook, |
5936 | "This hook is called just before expansion into rtl, allowing the target\n\ |
5937 | to perform additional initializations or analysis before the expansion.\n\ |
5938 | For example, the rs6000 port uses it to allocate a scratch stack slot\n\ |
5939 | for use in copying SDmode values between memory and floating point\n\ |
5940 | registers whenever the function being expanded has any SDmode\n\ |
5941 | usage." , |
5942 | void, (void), |
5943 | hook_void_void) |
5944 | |
5945 | /* This target hook allows the backend to perform additional |
5946 | instantiations on rtx that are not actually in insns yet, |
5947 | but will be later. */ |
5948 | DEFHOOK |
5949 | (instantiate_decls, |
5950 | "This hook allows the backend to perform additional instantiations on rtl\n\ |
5951 | that are not actually in any insns yet, but will be later." , |
5952 | void, (void), |
5953 | hook_void_void) |
5954 | |
5955 | DEFHOOK |
5956 | (hard_regno_nregs, |
5957 | "This hook returns the number of consecutive hard registers, starting\n\ |
5958 | at register number @var{regno}, required to hold a value of mode\n\ |
5959 | @var{mode}. This hook must never return zero, even if a register\n\ |
5960 | cannot hold the requested mode - indicate that with\n\ |
5961 | @code{TARGET_HARD_REGNO_MODE_OK} and/or\n\ |
5962 | @code{TARGET_CAN_CHANGE_MODE_CLASS} instead.\n\ |
5963 | \n\ |
5964 | The default definition returns the number of words in @var{mode}." , |
5965 | unsigned int, (unsigned int regno, machine_mode mode), |
5966 | default_hard_regno_nregs) |
5967 | |
5968 | DEFHOOK |
5969 | (hard_regno_mode_ok, |
5970 | "This hook returns true if it is permissible to store a value\n\ |
5971 | of mode @var{mode} in hard register number @var{regno} (or in several\n\ |
5972 | registers starting with that one). The default definition returns true\n\ |
5973 | unconditionally.\n\ |
5974 | \n\ |
5975 | You need not include code to check for the numbers of fixed registers,\n\ |
5976 | because the allocation mechanism considers them to be always occupied.\n\ |
5977 | \n\ |
5978 | @cindex register pairs\n\ |
5979 | On some machines, double-precision values must be kept in even/odd\n\ |
5980 | register pairs. You can implement that by defining this hook to reject\n\ |
5981 | odd register numbers for such modes.\n\ |
5982 | \n\ |
5983 | The minimum requirement for a mode to be OK in a register is that the\n\ |
5984 | @samp{mov@var{mode}} instruction pattern support moves between the\n\ |
5985 | register and other hard register in the same class and that moving a\n\ |
5986 | value into the register and back out not alter it.\n\ |
5987 | \n\ |
5988 | Since the same instruction used to move @code{word_mode} will work for\n\ |
5989 | all narrower integer modes, it is not necessary on any machine for\n\ |
5990 | this hook to distinguish between these modes, provided you define\n\ |
5991 | patterns @samp{movhi}, etc., to take advantage of this. This is\n\ |
5992 | useful because of the interaction between @code{TARGET_HARD_REGNO_MODE_OK}\n\ |
5993 | and @code{TARGET_MODES_TIEABLE_P}; it is very desirable for all integer\n\ |
5994 | modes to be tieable.\n\ |
5995 | \n\ |
5996 | Many machines have special registers for floating point arithmetic.\n\ |
5997 | Often people assume that floating point machine modes are allowed only\n\ |
5998 | in floating point registers. This is not true. Any registers that\n\ |
5999 | can hold integers can safely @emph{hold} a floating point machine\n\ |
6000 | mode, whether or not floating arithmetic can be done on it in those\n\ |
6001 | registers. Integer move instructions can be used to move the values.\n\ |
6002 | \n\ |
6003 | On some machines, though, the converse is true: fixed-point machine\n\ |
6004 | modes may not go in floating registers. This is true if the floating\n\ |
6005 | registers normalize any value stored in them, because storing a\n\ |
6006 | non-floating value there would garble it. In this case,\n\ |
6007 | @code{TARGET_HARD_REGNO_MODE_OK} should reject fixed-point machine modes in\n\ |
6008 | floating registers. But if the floating registers do not automatically\n\ |
6009 | normalize, if you can store any bit pattern in one and retrieve it\n\ |
6010 | unchanged without a trap, then any machine mode may go in a floating\n\ |
6011 | register, so you can define this hook to say so.\n\ |
6012 | \n\ |
6013 | The primary significance of special floating registers is rather that\n\ |
6014 | they are the registers acceptable in floating point arithmetic\n\ |
6015 | instructions. However, this is of no concern to\n\ |
6016 | @code{TARGET_HARD_REGNO_MODE_OK}. You handle it by writing the proper\n\ |
6017 | constraints for those instructions.\n\ |
6018 | \n\ |
6019 | On some machines, the floating registers are especially slow to access,\n\ |
6020 | so that it is better to store a value in a stack frame than in such a\n\ |
6021 | register if floating point arithmetic is not being done. As long as the\n\ |
6022 | floating registers are not in class @code{GENERAL_REGS}, they will not\n\ |
6023 | be used unless some pattern's constraint asks for one." , |
6024 | bool, (unsigned int regno, machine_mode mode), |
6025 | hook_bool_uint_mode_true) |
6026 | |
6027 | DEFHOOK |
6028 | (modes_tieable_p, |
6029 | "This hook returns true if a value of mode @var{mode1} is accessible\n\ |
6030 | in mode @var{mode2} without copying.\n\ |
6031 | \n\ |
6032 | If @code{TARGET_HARD_REGNO_MODE_OK (@var{r}, @var{mode1})} and\n\ |
6033 | @code{TARGET_HARD_REGNO_MODE_OK (@var{r}, @var{mode2})} are always\n\ |
6034 | the same for any @var{r}, then\n\ |
6035 | @code{TARGET_MODES_TIEABLE_P (@var{mode1}, @var{mode2})}\n\ |
6036 | should be true. If they differ for any @var{r}, you should define\n\ |
6037 | this hook to return false unless some other mechanism ensures the\n\ |
6038 | accessibility of the value in a narrower mode.\n\ |
6039 | \n\ |
6040 | You should define this hook to return true in as many cases as\n\ |
6041 | possible since doing so will allow GCC to perform better register\n\ |
6042 | allocation. The default definition returns true unconditionally." , |
6043 | bool, (machine_mode mode1, machine_mode mode2), |
6044 | hook_bool_mode_mode_true) |
6045 | |
6046 | /* Return true if is OK to use a hard register REGNO as scratch register |
6047 | in peephole2. */ |
6048 | DEFHOOK |
6049 | (hard_regno_scratch_ok, |
6050 | "This target hook should return @code{true} if it is OK to use a hard register\n\ |
6051 | @var{regno} as scratch reg in peephole2.\n\ |
6052 | \n\ |
6053 | One common use of this macro is to prevent using of a register that\n\ |
6054 | is not saved by a prologue in an interrupt handler.\n\ |
6055 | \n\ |
6056 | The default version of this hook always returns @code{true}." , |
6057 | bool, (unsigned int regno), |
6058 | default_hard_regno_scratch_ok) |
6059 | |
6060 | DEFHOOK |
6061 | (hard_regno_call_part_clobbered, |
6062 | "ABIs usually specify that calls must preserve the full contents\n\ |
6063 | of a particular register, or that calls can alter any part of a\n\ |
6064 | particular register. This information is captured by the target macro\n\ |
6065 | @code{CALL_REALLY_USED_REGISTERS}. However, some ABIs specify that calls\n\ |
6066 | must preserve certain bits of a particular register but can alter others.\n\ |
6067 | This hook should return true if this applies to at least one of the\n\ |
6068 | registers in @samp{(reg:@var{mode} @var{regno})}, and if as a result the\n\ |
6069 | call would alter part of the @var{mode} value. For example, if a call\n\ |
6070 | preserves the low 32 bits of a 64-bit hard register @var{regno} but can\n\ |
6071 | clobber the upper 32 bits, this hook should return true for a 64-bit mode\n\ |
6072 | but false for a 32-bit mode.\n\ |
6073 | \n\ |
6074 | The value of @var{abi_id} comes from the @code{predefined_function_abi}\n\ |
6075 | structure that describes the ABI of the call; see the definition of the\n\ |
6076 | structure for more details. If (as is usual) the target uses the same ABI\n\ |
6077 | for all functions in a translation unit, @var{abi_id} is always 0.\n\ |
6078 | \n\ |
6079 | The default implementation returns false, which is correct\n\ |
6080 | for targets that don't have partly call-clobbered registers." , |
6081 | bool, (unsigned int abi_id, unsigned int regno, machine_mode mode), |
6082 | hook_bool_uint_uint_mode_false) |
6083 | |
6084 | DEFHOOK |
6085 | (get_multilib_abi_name, |
6086 | "This hook returns name of multilib ABI name." , |
6087 | const char *, (void), |
6088 | hook_constcharptr_void_null) |
6089 | |
6090 | /* Return the smallest number of different values for which it is best to |
6091 | use a jump-table instead of a tree of conditional branches. */ |
6092 | DEFHOOK |
6093 | (case_values_threshold, |
6094 | "This function return the smallest number of different values for which it\n\ |
6095 | is best to use a jump-table instead of a tree of conditional branches.\n\ |
6096 | The default is four for machines with a @code{casesi} instruction and\n\ |
6097 | five otherwise. This is best for most machines." , |
6098 | unsigned int, (void), |
6099 | default_case_values_threshold) |
6100 | |
6101 | DEFHOOK |
6102 | (starting_frame_offset, |
6103 | "This hook returns the offset from the frame pointer to the first local\n\ |
6104 | variable slot to be allocated. If @code{FRAME_GROWS_DOWNWARD}, it is the\n\ |
6105 | offset to @emph{end} of the first slot allocated, otherwise it is the\n\ |
6106 | offset to @emph{beginning} of the first slot allocated. The default\n\ |
6107 | implementation returns 0." , |
6108 | HOST_WIDE_INT, (void), |
6109 | hook_hwi_void_0) |
6110 | |
6111 | /* Optional callback to advise the target to compute the frame layout. */ |
6112 | DEFHOOK |
6113 | (compute_frame_layout, |
6114 | "This target hook is called once each time the frame layout needs to be\n\ |
6115 | recalculated. The calculations can be cached by the target and can then\n\ |
6116 | be used by @code{INITIAL_ELIMINATION_OFFSET} instead of re-computing the\n\ |
6117 | layout on every invocation of that hook. This is particularly useful\n\ |
6118 | for targets that have an expensive frame layout function. Implementing\n\ |
6119 | this callback is optional." , |
6120 | void, (void), |
6121 | hook_void_void) |
6122 | |
6123 | /* Return true if a function must have and use a frame pointer. */ |
6124 | DEFHOOK |
6125 | (frame_pointer_required, |
6126 | "This target hook should return @code{true} if a function must have and use\n\ |
6127 | a frame pointer. This target hook is called in the reload pass. If its return\n\ |
6128 | value is @code{true} the function will have a frame pointer.\n\ |
6129 | \n\ |
6130 | This target hook can in principle examine the current function and decide\n\ |
6131 | according to the facts, but on most machines the constant @code{false} or the\n\ |
6132 | constant @code{true} suffices. Use @code{false} when the machine allows code\n\ |
6133 | to be generated with no frame pointer, and doing so saves some time or space.\n\ |
6134 | Use @code{true} when there is no possible advantage to avoiding a frame\n\ |
6135 | pointer.\n\ |
6136 | \n\ |
6137 | In certain cases, the compiler does not know how to produce valid code\n\ |
6138 | without a frame pointer. The compiler recognizes those cases and\n\ |
6139 | automatically gives the function a frame pointer regardless of what\n\ |
6140 | @code{targetm.frame_pointer_required} returns. You don't need to worry about\n\ |
6141 | them.\n\ |
6142 | \n\ |
6143 | In a function that does not require a frame pointer, the frame pointer\n\ |
6144 | register can be allocated for ordinary usage, unless you mark it as a\n\ |
6145 | fixed register. See @code{FIXED_REGISTERS} for more information.\n\ |
6146 | \n\ |
6147 | Default return value is @code{false}." , |
6148 | bool, (void), |
6149 | hook_bool_void_false) |
6150 | |
6151 | /* Returns true if the compiler is allowed to try to replace register number |
6152 | from-reg with register number to-reg. */ |
6153 | DEFHOOK |
6154 | (can_eliminate, |
6155 | "This target hook should return @code{true} if the compiler is allowed to\n\ |
6156 | try to replace register number @var{from_reg} with register number\n\ |
6157 | @var{to_reg}. This target hook will usually be @code{true}, since most of the\n\ |
6158 | cases preventing register elimination are things that the compiler already\n\ |
6159 | knows about.\n\ |
6160 | \n\ |
6161 | Default return value is @code{true}." , |
6162 | bool, (const int from_reg, const int to_reg), |
6163 | hook_bool_const_int_const_int_true) |
6164 | |
6165 | /* Modify any or all of fixed_regs, call_used_regs, global_regs, |
6166 | reg_names, and reg_class_contents to account of the vagaries of the |
6167 | target. */ |
6168 | DEFHOOK |
6169 | (conditional_register_usage, |
6170 | "This hook may conditionally modify five variables\n\ |
6171 | @code{fixed_regs}, @code{call_used_regs}, @code{global_regs},\n\ |
6172 | @code{reg_names}, and @code{reg_class_contents}, to take into account\n\ |
6173 | any dependence of these register sets on target flags. The first three\n\ |
6174 | of these are of type @code{char []} (interpreted as boolean vectors).\n\ |
6175 | @code{global_regs} is a @code{const char *[]}, and\n\ |
6176 | @code{reg_class_contents} is a @code{HARD_REG_SET}. Before the macro is\n\ |
6177 | called, @code{fixed_regs}, @code{call_used_regs},\n\ |
6178 | @code{reg_class_contents}, and @code{reg_names} have been initialized\n\ |
6179 | from @code{FIXED_REGISTERS}, @code{CALL_USED_REGISTERS},\n\ |
6180 | @code{REG_CLASS_CONTENTS}, and @code{REGISTER_NAMES}, respectively.\n\ |
6181 | @code{global_regs} has been cleared, and any @option{-ffixed-@var{reg}},\n\ |
6182 | @option{-fcall-used-@var{reg}} and @option{-fcall-saved-@var{reg}}\n\ |
6183 | command options have been applied.\n\ |
6184 | \n\ |
6185 | @cindex disabling certain registers\n\ |
6186 | @cindex controlling register usage\n\ |
6187 | If the usage of an entire class of registers depends on the target\n\ |
6188 | flags, you may indicate this to GCC by using this macro to modify\n\ |
6189 | @code{fixed_regs} and @code{call_used_regs} to 1 for each of the\n\ |
6190 | registers in the classes which should not be used by GCC@. Also make\n\ |
6191 | @code{define_register_constraint}s return @code{NO_REGS} for constraints\n\ |
6192 | that shouldn't be used.\n\ |
6193 | \n\ |
6194 | (However, if this class is not included in @code{GENERAL_REGS} and all\n\ |
6195 | of the insn patterns whose constraints permit this class are\n\ |
6196 | controlled by target switches, then GCC will automatically avoid using\n\ |
6197 | these registers when the target switches are opposed to them.)" , |
6198 | void, (void), |
6199 | hook_void_void) |
6200 | |
6201 | DEFHOOK |
6202 | (stack_clash_protection_alloca_probe_range, |
6203 | "Some targets have an ABI defined interval for which no probing needs to be done.\n\ |
6204 | When a probe does need to be done this same interval is used as the probe distance\n\ |
6205 | up when doing stack clash protection for alloca.\n\ |
6206 | On such targets this value can be set to override the default probing up interval.\n\ |
6207 | Define this variable to return nonzero if such a probe range is required or zero otherwise.\n\ |
6208 | Defining this hook also requires your functions which make use of alloca to have at least 8 byes\n\ |
6209 | of outgoing arguments. If this is not the case the stack will be corrupted.\n\ |
6210 | You need not define this macro if it would always have the value zero." , |
6211 | HOST_WIDE_INT, (void), |
6212 | default_stack_clash_protection_alloca_probe_range) |
6213 | |
6214 | |
6215 | /* Functions specific to the C family of frontends. */ |
6216 | #undef HOOK_PREFIX |
6217 | #define HOOK_PREFIX "TARGET_C_" |
6218 | HOOK_VECTOR (TARGET_C, c) |
6219 | |
6220 | /* ??? Documenting this hook requires a GFDL license grant. */ |
6221 | DEFHOOK_UNDOC |
6222 | (mode_for_suffix, |
6223 | "Return machine mode for non-standard constant literal suffix @var{c},\ |
6224 | or VOIDmode if non-standard suffixes are unsupported." , |
6225 | machine_mode, (char c), |
6226 | default_mode_for_suffix) |
6227 | |
6228 | DEFHOOK |
6229 | (excess_precision, |
6230 | "Return a value, with the same meaning as the C99 macro\n\ |
6231 | @code{FLT_EVAL_METHOD} that describes which excess precision should be\n\ |
6232 | applied. @var{type} is either @code{EXCESS_PRECISION_TYPE_IMPLICIT},\n\ |
6233 | @code{EXCESS_PRECISION_TYPE_FAST},\n\ |
6234 | @code{EXCESS_PRECISION_TYPE_STANDARD}, or\n\ |
6235 | @code{EXCESS_PRECISION_TYPE_FLOAT16}. For\n\ |
6236 | @code{EXCESS_PRECISION_TYPE_IMPLICIT}, the target should return which\n\ |
6237 | precision and range operations will be implictly evaluated in regardless\n\ |
6238 | of the excess precision explicitly added. For\n\ |
6239 | @code{EXCESS_PRECISION_TYPE_STANDARD}, \n\ |
6240 | @code{EXCESS_PRECISION_TYPE_FLOAT16}, and\n\ |
6241 | @code{EXCESS_PRECISION_TYPE_FAST}, the target should return the\n\ |
6242 | explicit excess precision that should be added depending on the\n\ |
6243 | value set for @option{-fexcess-precision=@r{[}standard@r{|}fast@r{|}16@r{]}}.\n\ |
6244 | Note that unpredictable explicit excess precision does not make sense,\n\ |
6245 | so a target should never return @code{FLT_EVAL_METHOD_UNPREDICTABLE}\n\ |
6246 | when @var{type} is @code{EXCESS_PRECISION_TYPE_STANDARD},\n\ |
6247 | @code{EXCESS_PRECISION_TYPE_FLOAT16} or\n\ |
6248 | @code{EXCESS_PRECISION_TYPE_FAST}." , |
6249 | enum flt_eval_method, (enum excess_precision_type type), |
6250 | default_excess_precision) |
6251 | |
6252 | /* Return true if _BitInt(N) is supported and fill details about it into |
6253 | *INFO. */ |
6254 | DEFHOOK |
6255 | (bitint_type_info, |
6256 | "This target hook returns true if @code{_BitInt(@var{N})} is supported and\n\ |
6257 | provides details on it. @code{_BitInt(@var{N})} is to be represented as\n\ |
6258 | series of @code{info->limb_mode}\n\ |
6259 | @code{CEIL (@var{N}, GET_MODE_PRECISION (info->limb_mode))} limbs,\n\ |
6260 | ordered from least significant to most significant if\n\ |
6261 | @code{!info->big_endian}, otherwise from most significant to least\n\ |
6262 | significant. If @code{info->extended} is false, the bits above or equal to\n\ |
6263 | @var{N} are undefined when stored in a register or memory, otherwise they\n\ |
6264 | are zero or sign extended depending on if it is\n\ |
6265 | @code{unsigned _BitInt(@var{N})} or one of @code{_BitInt(@var{N})} or\n\ |
6266 | @code{signed _BitInt(@var{N})}. Alignment of the type is\n\ |
6267 | @code{GET_MODE_ALIGNMENT (info->limb_mode)}." , |
6268 | bool, (int n, struct bitint_info *info), |
6269 | default_bitint_type_info) |
6270 | |
6271 | HOOK_VECTOR_END (c) |
6272 | |
6273 | /* Functions specific to the C++ frontend. */ |
6274 | #undef HOOK_PREFIX |
6275 | #define HOOK_PREFIX "TARGET_CXX_" |
6276 | HOOK_VECTOR (TARGET_CXX, cxx) |
6277 | |
6278 | /* Return the integer type used for guard variables. */ |
6279 | DEFHOOK |
6280 | (guard_type, |
6281 | "Define this hook to override the integer type used for guard variables.\n\ |
6282 | These are used to implement one-time construction of static objects. The\n\ |
6283 | default is long_long_integer_type_node." , |
6284 | tree, (void), |
6285 | default_cxx_guard_type) |
6286 | |
6287 | /* Return true if only the low bit of the guard should be tested. */ |
6288 | DEFHOOK |
6289 | (guard_mask_bit, |
6290 | "This hook determines how guard variables are used. It should return\n\ |
6291 | @code{false} (the default) if the first byte should be used. A return value of\n\ |
6292 | @code{true} indicates that only the least significant bit should be used." , |
6293 | bool, (void), |
6294 | hook_bool_void_false) |
6295 | |
6296 | /* Returns the size of the array cookie for an array of type. */ |
6297 | DEFHOOK |
6298 | (get_cookie_size, |
6299 | "This hook returns the size of the cookie to use when allocating an array\n\ |
6300 | whose elements have the indicated @var{type}. Assumes that it is already\n\ |
6301 | known that a cookie is needed. The default is\n\ |
6302 | @code{max(sizeof (size_t), alignof(type))}, as defined in section 2.7 of the\n\ |
6303 | IA64/Generic C++ ABI@." , |
6304 | tree, (tree type), |
6305 | default_cxx_get_cookie_size) |
6306 | |
6307 | /* Returns true if the element size should be stored in the array cookie. */ |
6308 | DEFHOOK |
6309 | (cookie_has_size, |
6310 | "This hook should return @code{true} if the element size should be stored in\n\ |
6311 | array cookies. The default is to return @code{false}." , |
6312 | bool, (void), |
6313 | hook_bool_void_false) |
6314 | |
6315 | /* Allows backends to perform additional processing when |
6316 | deciding if a class should be exported or imported. */ |
6317 | DEFHOOK |
6318 | (import_export_class, |
6319 | "If defined by a backend this hook allows the decision made to export\n\ |
6320 | class @var{type} to be overruled. Upon entry @var{import_export}\n\ |
6321 | will contain 1 if the class is going to be exported, @minus{}1 if it is going\n\ |
6322 | to be imported and 0 otherwise. This function should return the\n\ |
6323 | modified value and perform any other actions necessary to support the\n\ |
6324 | backend's targeted operating system." , |
6325 | int, (tree type, int import_export), NULL) |
6326 | |
6327 | /* Returns true if constructors and destructors return "this". */ |
6328 | DEFHOOK |
6329 | (cdtor_returns_this, |
6330 | "This hook should return @code{true} if constructors and destructors return\n\ |
6331 | the address of the object created/destroyed. The default is to return\n\ |
6332 | @code{false}." , |
6333 | bool, (void), |
6334 | hook_bool_void_false) |
6335 | |
6336 | /* Returns true if the key method for a class can be an inline |
6337 | function, so long as it is not declared inline in the class |
6338 | itself. Returning true is the behavior required by the Itanium C++ ABI. */ |
6339 | DEFHOOK |
6340 | (key_method_may_be_inline, |
6341 | "This hook returns true if the key method for a class (i.e., the method\n\ |
6342 | which, if defined in the current translation unit, causes the virtual\n\ |
6343 | table to be emitted) may be an inline function. Under the standard\n\ |
6344 | Itanium C++ ABI the key method may be an inline function so long as\n\ |
6345 | the function is not declared inline in the class definition. Under\n\ |
6346 | some variants of the ABI, an inline function can never be the key\n\ |
6347 | method. The default is to return @code{true}." , |
6348 | bool, (void), |
6349 | hook_bool_void_true) |
6350 | |
6351 | DEFHOOK |
6352 | (determine_class_data_visibility, |
6353 | "@var{decl} is a virtual table, virtual table table, typeinfo object,\n\ |
6354 | or other similar implicit class data object that will be emitted with\n\ |
6355 | external linkage in this translation unit. No ELF visibility has been\n\ |
6356 | explicitly specified. If the target needs to specify a visibility\n\ |
6357 | other than that of the containing class, use this hook to set\n\ |
6358 | @code{DECL_VISIBILITY} and @code{DECL_VISIBILITY_SPECIFIED}." , |
6359 | void, (tree decl), |
6360 | hook_void_tree) |
6361 | |
6362 | /* Returns true (the default) if virtual tables and other |
6363 | similar implicit class data objects are always COMDAT if they |
6364 | have external linkage. If this hook returns false, then |
6365 | class data for classes whose virtual table will be emitted in |
6366 | only one translation unit will not be COMDAT. */ |
6367 | DEFHOOK |
6368 | (class_data_always_comdat, |
6369 | "This hook returns true (the default) if virtual tables and other\n\ |
6370 | similar implicit class data objects are always COMDAT if they have\n\ |
6371 | external linkage. If this hook returns false, then class data for\n\ |
6372 | classes whose virtual table will be emitted in only one translation\n\ |
6373 | unit will not be COMDAT." , |
6374 | bool, (void), |
6375 | hook_bool_void_true) |
6376 | |
6377 | /* Returns true (the default) if the RTTI for the basic types, |
6378 | which is always defined in the C++ runtime, should be COMDAT; |
6379 | false if it should not be COMDAT. */ |
6380 | DEFHOOK |
6381 | (library_rtti_comdat, |
6382 | "This hook returns true (the default) if the RTTI information for\n\ |
6383 | the basic types which is defined in the C++ runtime should always\n\ |
6384 | be COMDAT, false if it should not be COMDAT." , |
6385 | bool, (void), |
6386 | hook_bool_void_true) |
6387 | |
6388 | /* Returns true if __aeabi_atexit should be used to register static |
6389 | destructors. */ |
6390 | DEFHOOK |
6391 | (use_aeabi_atexit, |
6392 | "This hook returns true if @code{__aeabi_atexit} (as defined by the ARM EABI)\n\ |
6393 | should be used to register static destructors when @option{-fuse-cxa-atexit}\n\ |
6394 | is in effect. The default is to return false to use @code{__cxa_atexit}." , |
6395 | bool, (void), |
6396 | hook_bool_void_false) |
6397 | |
6398 | /* Returns true if target may use atexit in the same manner as |
6399 | __cxa_atexit to register static destructors. */ |
6400 | DEFHOOK |
6401 | (use_atexit_for_cxa_atexit, |
6402 | "This hook returns true if the target @code{atexit} function can be used\n\ |
6403 | in the same manner as @code{__cxa_atexit} to register C++ static\n\ |
6404 | destructors. This requires that @code{atexit}-registered functions in\n\ |
6405 | shared libraries are run in the correct order when the libraries are\n\ |
6406 | unloaded. The default is to return false." , |
6407 | bool, (void), |
6408 | hook_bool_void_false) |
6409 | |
6410 | DEFHOOK |
6411 | (adjust_class_at_definition, |
6412 | "@var{type} is a C++ class (i.e., RECORD_TYPE or UNION_TYPE) that has just\n\ |
6413 | been defined. Use this hook to make adjustments to the class (eg, tweak\n\ |
6414 | visibility or perform any other required target modifications)." , |
6415 | void, (tree type), |
6416 | hook_void_tree) |
6417 | |
6418 | DEFHOOK |
6419 | (decl_mangling_context, |
6420 | "Return target-specific mangling context of @var{decl} or @code{NULL_TREE}." , |
6421 | tree, (const_tree decl), |
6422 | hook_tree_const_tree_null) |
6423 | |
6424 | HOOK_VECTOR_END (cxx) |
6425 | |
6426 | /* Functions and data for emulated TLS support. */ |
6427 | #undef HOOK_PREFIX |
6428 | #define HOOK_PREFIX "TARGET_EMUTLS_" |
6429 | HOOK_VECTOR (TARGET_EMUTLS, emutls) |
6430 | |
6431 | /* Name of the address and common functions. */ |
6432 | DEFHOOKPOD |
6433 | (get_address, |
6434 | "Contains the name of the helper function that uses a TLS control\n\ |
6435 | object to locate a TLS instance. The default causes libgcc's\n\ |
6436 | emulated TLS helper function to be used." , |
6437 | const char *, "__builtin___emutls_get_address" ) |
6438 | |
6439 | DEFHOOKPOD |
6440 | (register_common, |
6441 | "Contains the name of the helper function that should be used at\n\ |
6442 | program startup to register TLS objects that are implicitly\n\ |
6443 | initialized to zero. If this is @code{NULL}, all TLS objects will\n\ |
6444 | have explicit initializers. The default causes libgcc's emulated TLS\n\ |
6445 | registration function to be used." , |
6446 | const char *, "__builtin___emutls_register_common" ) |
6447 | |
6448 | /* Prefixes for proxy variable and template. */ |
6449 | DEFHOOKPOD |
6450 | (var_section, |
6451 | "Contains the name of the section in which TLS control variables should\n\ |
6452 | be placed. The default of @code{NULL} allows these to be placed in\n\ |
6453 | any section." , |
6454 | const char *, NULL) |
6455 | |
6456 | DEFHOOKPOD |
6457 | (tmpl_section, |
6458 | "Contains the name of the section in which TLS initializers should be\n\ |
6459 | placed. The default of @code{NULL} allows these to be placed in any\n\ |
6460 | section." , |
6461 | const char *, NULL) |
6462 | |
6463 | /* Prefixes for proxy variable and template. */ |
6464 | DEFHOOKPOD |
6465 | (var_prefix, |
6466 | "Contains the prefix to be prepended to TLS control variable names.\n\ |
6467 | The default of @code{NULL} uses a target-specific prefix." , |
6468 | const char *, NULL) |
6469 | |
6470 | DEFHOOKPOD |
6471 | (tmpl_prefix, |
6472 | "Contains the prefix to be prepended to TLS initializer objects. The\n\ |
6473 | default of @code{NULL} uses a target-specific prefix." , |
6474 | const char *, NULL) |
6475 | |
6476 | /* Function to generate field definitions of the proxy variable. */ |
6477 | DEFHOOK |
6478 | (var_fields, |
6479 | "Specifies a function that generates the FIELD_DECLs for a TLS control\n\ |
6480 | object type. @var{type} is the RECORD_TYPE the fields are for and\n\ |
6481 | @var{name} should be filled with the structure tag, if the default of\n\ |
6482 | @code{__emutls_object} is unsuitable. The default creates a type suitable\n\ |
6483 | for libgcc's emulated TLS function." , |
6484 | tree, (tree type, tree *name), |
6485 | default_emutls_var_fields) |
6486 | |
6487 | /* Function to initialize a proxy variable. */ |
6488 | DEFHOOK |
6489 | (var_init, |
6490 | "Specifies a function that generates the CONSTRUCTOR to initialize a\n\ |
6491 | TLS control object. @var{var} is the TLS control object, @var{decl}\n\ |
6492 | is the TLS object and @var{tmpl_addr} is the address of the\n\ |
6493 | initializer. The default initializes libgcc's emulated TLS control object." , |
6494 | tree, (tree var, tree decl, tree tmpl_addr), |
6495 | default_emutls_var_init) |
6496 | |
6497 | /* Whether we are allowed to alter the usual alignment of the |
6498 | proxy variable. */ |
6499 | DEFHOOKPOD |
6500 | (var_align_fixed, |
6501 | "Specifies whether the alignment of TLS control variable objects is\n\ |
6502 | fixed and should not be increased as some backends may do to optimize\n\ |
6503 | single objects. The default is false." , |
6504 | bool, false) |
6505 | |
6506 | /* Whether we can emit debug information for TLS vars. */ |
6507 | DEFHOOKPOD |
6508 | (debug_form_tls_address, |
6509 | "Specifies whether a DWARF @code{DW_OP_form_tls_address} location descriptor\n\ |
6510 | may be used to describe emulated TLS control objects." , |
6511 | bool, false) |
6512 | |
6513 | HOOK_VECTOR_END (emutls) |
6514 | |
6515 | #undef HOOK_PREFIX |
6516 | #define HOOK_PREFIX "TARGET_OPTION_" |
6517 | HOOK_VECTOR (TARGET_OPTION_HOOKS, target_option_hooks) |
6518 | |
6519 | /* Function to validate the attribute((target(...))) strings. If |
6520 | the option is validated, the hook should also fill in |
6521 | DECL_FUNCTION_SPECIFIC_TARGET in the function decl node. */ |
6522 | DEFHOOK |
6523 | (valid_attribute_p, |
6524 | "This hook is called to parse @code{attribute(target(\"...\"))}, which\n\ |
6525 | allows setting target-specific options on individual functions.\n\ |
6526 | These function-specific options may differ\n\ |
6527 | from the options specified on the command line. The hook should return\n\ |
6528 | @code{true} if the options are valid.\n\ |
6529 | \n\ |
6530 | The hook should set the @code{DECL_FUNCTION_SPECIFIC_TARGET} field in\n\ |
6531 | the function declaration to hold a pointer to a target-specific\n\ |
6532 | @code{struct cl_target_option} structure." , |
6533 | bool, (tree fndecl, tree name, tree args, int flags), |
6534 | default_target_option_valid_attribute_p) |
6535 | |
6536 | /* Function to save any extra target state in the target options structure. */ |
6537 | DEFHOOK |
6538 | (save, |
6539 | "This hook is called to save any additional target-specific information\n\ |
6540 | in the @code{struct cl_target_option} structure for function-specific\n\ |
6541 | options from the @code{struct gcc_options} structure.\n\ |
6542 | @xref{Option file format}." , |
6543 | void, (struct cl_target_option *ptr, struct gcc_options *opts, |
6544 | struct gcc_options *opts_set), NULL) |
6545 | |
6546 | /* Function to restore any extra target state from the target options |
6547 | structure. */ |
6548 | DEFHOOK |
6549 | (restore, |
6550 | "This hook is called to restore any additional target-specific\n\ |
6551 | information in the @code{struct cl_target_option} structure for\n\ |
6552 | function-specific options to the @code{struct gcc_options} structure." , |
6553 | void, (struct gcc_options *opts, struct gcc_options *opts_set, |
6554 | struct cl_target_option *ptr), NULL) |
6555 | |
6556 | /* Function to update target-specific option information after being |
6557 | streamed in. */ |
6558 | DEFHOOK |
6559 | (post_stream_in, |
6560 | "This hook is called to update target-specific information in the\n\ |
6561 | @code{struct cl_target_option} structure after it is streamed in from\n\ |
6562 | LTO bytecode." , |
6563 | void, (struct cl_target_option *ptr), NULL) |
6564 | |
6565 | /* Function to print any extra target state from the target options |
6566 | structure. */ |
6567 | DEFHOOK |
6568 | (print, |
6569 | "This hook is called to print any additional target-specific\n\ |
6570 | information in the @code{struct cl_target_option} structure for\n\ |
6571 | function-specific options." , |
6572 | void, (FILE *file, int indent, struct cl_target_option *ptr), NULL) |
6573 | |
6574 | /* Function to parse arguments to be validated for #pragma target, and to |
6575 | change the state if the options are valid. If the first argument is |
6576 | NULL, the second argument specifies the default options to use. Return |
6577 | true if the options are valid, and set the current state. */ |
6578 | DEFHOOK |
6579 | (pragma_parse, |
6580 | "This target hook parses the options for @code{#pragma GCC target}, which\n\ |
6581 | sets the target-specific options for functions that occur later in the\n\ |
6582 | input stream. The options accepted should be the same as those handled by the\n\ |
6583 | @code{TARGET_OPTION_VALID_ATTRIBUTE_P} hook." , |
6584 | bool, (tree args, tree pop_target), |
6585 | default_target_option_pragma_parse) |
6586 | |
6587 | /* Do option overrides for the target. */ |
6588 | DEFHOOK |
6589 | (override, |
6590 | "Sometimes certain combinations of command options do not make sense on\n\ |
6591 | a particular target machine. You can override the hook\n\ |
6592 | @code{TARGET_OPTION_OVERRIDE} to take account of this. This hooks is called\n\ |
6593 | once just after all the command options have been parsed.\n\ |
6594 | \n\ |
6595 | Don't use this hook to turn on various extra optimizations for\n\ |
6596 | @option{-O}. That is what @code{TARGET_OPTION_OPTIMIZATION} is for.\n\ |
6597 | \n\ |
6598 | If you need to do something whenever the optimization level is\n\ |
6599 | changed via the optimize attribute or pragma, see\n\ |
6600 | @code{TARGET_OVERRIDE_OPTIONS_AFTER_CHANGE}" , |
6601 | void, (void), |
6602 | hook_void_void) |
6603 | |
6604 | /* This function returns true if DECL1 and DECL2 are versions of the same |
6605 | function. DECL1 and DECL2 are function versions if and only if they |
6606 | have the same function signature and different target specific attributes, |
6607 | that is, they are compiled for different target machines. */ |
6608 | DEFHOOK |
6609 | (function_versions, |
6610 | "This target hook returns @code{true} if @var{DECL1} and @var{DECL2} are\n\ |
6611 | versions of the same function. @var{DECL1} and @var{DECL2} are function\n\ |
6612 | versions if and only if they have the same function signature and\n\ |
6613 | different target specific attributes, that is, they are compiled for\n\ |
6614 | different target machines." , |
6615 | bool, (tree decl1, tree decl2), |
6616 | hook_bool_tree_tree_false) |
6617 | |
6618 | /* Function to determine if one function can inline another function. */ |
6619 | #undef HOOK_PREFIX |
6620 | #define HOOK_PREFIX "TARGET_" |
6621 | DEFHOOK |
6622 | (can_inline_p, |
6623 | "This target hook returns @code{false} if the @var{caller} function\n\ |
6624 | cannot inline @var{callee}, based on target specific information. By\n\ |
6625 | default, inlining is not allowed if the callee function has function\n\ |
6626 | specific target options and the caller does not use the same options." , |
6627 | bool, (tree caller, tree callee), |
6628 | default_target_can_inline_p) |
6629 | |
6630 | DEFHOOK |
6631 | (update_ipa_fn_target_info, |
6632 | "Allow target to analyze all gimple statements for the given function to\n\ |
6633 | record and update some target specific information for inlining. A typical\n\ |
6634 | example is that a caller with one isa feature disabled is normally not\n\ |
6635 | allowed to inline a callee with that same isa feature enabled even which is\n\ |
6636 | attributed by always_inline, but with the conservative analysis on all\n\ |
6637 | statements of the callee if we are able to guarantee the callee does not\n\ |
6638 | exploit any instructions from the mismatch isa feature, it would be safe to\n\ |
6639 | allow the caller to inline the callee.\n\ |
6640 | @var{info} is one @code{unsigned int} value to record information in which\n\ |
6641 | one set bit indicates one corresponding feature is detected in the analysis,\n\ |
6642 | @var{stmt} is the statement being analyzed. Return true if target still\n\ |
6643 | need to analyze the subsequent statements, otherwise return false to stop\n\ |
6644 | subsequent analysis.\n\ |
6645 | The default version of this hook returns false." , |
6646 | bool, (unsigned int& info, const gimple* stmt), |
6647 | default_update_ipa_fn_target_info) |
6648 | |
6649 | DEFHOOK |
6650 | (need_ipa_fn_target_info, |
6651 | "Allow target to check early whether it is necessary to analyze all gimple\n\ |
6652 | statements in the given function to update target specific information for\n\ |
6653 | inlining. See hook @code{update_ipa_fn_target_info} for usage example of\n\ |
6654 | target specific information. This hook is expected to be invoked ahead of\n\ |
6655 | the iterating with hook @code{update_ipa_fn_target_info}.\n\ |
6656 | @var{decl} is the function being analyzed, @var{info} is the same as what\n\ |
6657 | in hook @code{update_ipa_fn_target_info}, target can do one time update\n\ |
6658 | into @var{info} without iterating for some case. Return true if target\n\ |
6659 | decides to analyze all gimple statements to collect information, otherwise\n\ |
6660 | return false.\n\ |
6661 | The default version of this hook returns false." , |
6662 | bool, (const_tree decl, unsigned int& info), |
6663 | default_need_ipa_fn_target_info) |
6664 | |
6665 | DEFHOOK |
6666 | (relayout_function, |
6667 | "This target hook fixes function @var{fndecl} after attributes are processed.\n\ |
6668 | Default does nothing. On ARM, the default function's alignment is updated\n\ |
6669 | with the attribute target." , |
6670 | void, (tree fndecl), |
6671 | hook_void_tree) |
6672 | |
6673 | HOOK_VECTOR_END (target_option) |
6674 | |
6675 | /* For targets that need to mark extra registers as live on entry to |
6676 | the function, they should define this target hook and set their |
6677 | bits in the bitmap passed in. */ |
6678 | DEFHOOK |
6679 | (, |
6680 | "Add any hard registers to @var{regs} that are live on entry to the\n\ |
6681 | function. This hook only needs to be defined to provide registers that\n\ |
6682 | cannot be found by examination of FUNCTION_ARG_REGNO_P, the callee saved\n\ |
6683 | registers, STATIC_CHAIN_INCOMING_REGNUM, STATIC_CHAIN_REGNUM,\n\ |
6684 | TARGET_STRUCT_VALUE_RTX, FRAME_POINTER_REGNUM, EH_USES,\n\ |
6685 | FRAME_POINTER_REGNUM, ARG_POINTER_REGNUM, and the PIC_OFFSET_TABLE_REGNUM." , |
6686 | void, (bitmap regs), |
6687 | hook_void_bitmap) |
6688 | |
6689 | /* Targets should define this target hook to mark that non-callee clobbers are |
6690 | present in CALL_INSN_FUNCTION_USAGE for all the calls that bind to a local |
6691 | definition. */ |
6692 | DEFHOOKPOD |
6693 | (call_fusage_contains_non_callee_clobbers, |
6694 | "Set to true if each call that binds to a local definition explicitly\n\ |
6695 | clobbers or sets all non-fixed registers modified by performing the call.\n\ |
6696 | That is, by the call pattern itself, or by code that might be inserted by the\n\ |
6697 | linker (e.g.@: stubs, veneers, branch islands), but not including those\n\ |
6698 | modifiable by the callee. The affected registers may be mentioned explicitly\n\ |
6699 | in the call pattern, or included as clobbers in CALL_INSN_FUNCTION_USAGE.\n\ |
6700 | The default version of this hook is set to false. The purpose of this hook\n\ |
6701 | is to enable the fipa-ra optimization." , |
6702 | bool, |
6703 | false) |
6704 | |
6705 | /* Fill in additional registers set up by prologue into a regset. */ |
6706 | DEFHOOK |
6707 | (set_up_by_prologue, |
6708 | "This hook should add additional registers that are computed by the prologue\n\ |
6709 | to the hard regset for shrink-wrapping optimization purposes." , |
6710 | void, (struct hard_reg_set_container *), |
6711 | NULL) |
6712 | |
6713 | /* For targets that have attributes that can affect whether a |
6714 | function's return statements need checking. For instance a 'naked' |
6715 | function attribute. */ |
6716 | DEFHOOK |
6717 | (warn_func_return, |
6718 | "True if a function's return statements should be checked for matching\n\ |
6719 | the function's return type. This includes checking for falling off the end\n\ |
6720 | of a non-void function. Return false if no such check should be made." , |
6721 | bool, (tree), |
6722 | hook_bool_tree_true) |
6723 | |
6724 | #undef HOOK_PREFIX |
6725 | #define HOOK_PREFIX "TARGET_SHRINK_WRAP_" |
6726 | HOOK_VECTOR (TARGET_SHRINK_WRAP_HOOKS, shrink_wrap) |
6727 | |
6728 | DEFHOOK |
6729 | (get_separate_components, |
6730 | "This hook should return an @code{sbitmap} with the bits set for those\n\ |
6731 | components that can be separately shrink-wrapped in the current function.\n\ |
6732 | Return @code{NULL} if the current function should not get any separate\n\ |
6733 | shrink-wrapping.\n\ |
6734 | Don't define this hook if it would always return @code{NULL}.\n\ |
6735 | If it is defined, the other hooks in this group have to be defined as well." , |
6736 | sbitmap, (void), |
6737 | NULL) |
6738 | |
6739 | DEFHOOK |
6740 | (components_for_bb, |
6741 | "This hook should return an @code{sbitmap} with the bits set for those\n\ |
6742 | components where either the prologue component has to be executed before\n\ |
6743 | the @code{basic_block}, or the epilogue component after it, or both." , |
6744 | sbitmap, (basic_block), |
6745 | NULL) |
6746 | |
6747 | DEFHOOK |
6748 | (disqualify_components, |
6749 | "This hook should clear the bits in the @var{components} bitmap for those\n\ |
6750 | components in @var{edge_components} that the target cannot handle on edge\n\ |
6751 | @var{e}, where @var{is_prologue} says if this is for a prologue or an\n\ |
6752 | epilogue instead." , |
6753 | void, (sbitmap components, edge e, sbitmap edge_components, bool is_prologue), |
6754 | NULL) |
6755 | |
6756 | DEFHOOK |
6757 | (emit_prologue_components, |
6758 | "Emit prologue insns for the components indicated by the parameter." , |
6759 | void, (sbitmap), |
6760 | NULL) |
6761 | |
6762 | DEFHOOK |
6763 | (emit_epilogue_components, |
6764 | "Emit epilogue insns for the components indicated by the parameter." , |
6765 | void, (sbitmap), |
6766 | NULL) |
6767 | |
6768 | DEFHOOK |
6769 | (set_handled_components, |
6770 | "Mark the components in the parameter as handled, so that the\n\ |
6771 | @code{prologue} and @code{epilogue} named patterns know to ignore those\n\ |
6772 | components. The target code should not hang on to the @code{sbitmap}, it\n\ |
6773 | will be deleted after this call." , |
6774 | void, (sbitmap), |
6775 | NULL) |
6776 | |
6777 | HOOK_VECTOR_END (shrink_wrap) |
6778 | #undef HOOK_PREFIX |
6779 | #define HOOK_PREFIX "TARGET_" |
6780 | |
6781 | /* Determine the type of unwind info to emit for debugging. */ |
6782 | DEFHOOK |
6783 | (debug_unwind_info, |
6784 | "This hook defines the mechanism that will be used for describing frame\n\ |
6785 | unwind information to the debugger. Normally the hook will return\n\ |
6786 | @code{UI_DWARF2} if DWARF 2 debug information is enabled, and\n\ |
6787 | return @code{UI_NONE} otherwise.\n\ |
6788 | \n\ |
6789 | A target may return @code{UI_DWARF2} even when DWARF 2 debug information\n\ |
6790 | is disabled in order to always output DWARF 2 frame information.\n\ |
6791 | \n\ |
6792 | A target may return @code{UI_TARGET} if it has ABI specified unwind tables.\n\ |
6793 | This will suppress generation of the normal debug frame unwind information." , |
6794 | enum unwind_info_type, (void), |
6795 | default_debug_unwind_info) |
6796 | |
6797 | DEFHOOK |
6798 | (reset_location_view, |
6799 | "This hook, if defined, enables -ginternal-reset-location-views, and\n\ |
6800 | uses its result to override cases in which the estimated min insn\n\ |
6801 | length might be nonzero even when a PC advance (i.e., a view reset)\n\ |
6802 | cannot be taken for granted.\n\ |
6803 | \n\ |
6804 | If the hook is defined, it must return a positive value to indicate\n\ |
6805 | the insn definitely advances the PC, and so the view number can be\n\ |
6806 | safely assumed to be reset; a negative value to mean the insn\n\ |
6807 | definitely does not advance the PC, and os the view number must not\n\ |
6808 | be reset; or zero to decide based on the estimated insn length.\n\ |
6809 | \n\ |
6810 | If insn length is to be regarded as reliable, set the hook to\n\ |
6811 | @code{hook_int_rtx_insn_0}." , |
6812 | int, (rtx_insn *), NULL) |
6813 | |
6814 | /* The code parameter should be of type enum rtx_code but this is not |
6815 | defined at this time. */ |
6816 | DEFHOOK |
6817 | (canonicalize_comparison, |
6818 | "On some machines not all possible comparisons are defined, but you can\n\ |
6819 | convert an invalid comparison into a valid one. For example, the Alpha\n\ |
6820 | does not have a @code{GT} comparison, but you can use an @code{LT}\n\ |
6821 | comparison instead and swap the order of the operands.\n\ |
6822 | \n\ |
6823 | On such machines, implement this hook to do any required conversions.\n\ |
6824 | @var{code} is the initial comparison code and @var{op0} and @var{op1}\n\ |
6825 | are the left and right operands of the comparison, respectively. If\n\ |
6826 | @var{op0_preserve_value} is @code{true} the implementation is not\n\ |
6827 | allowed to change the value of @var{op0} since the value might be used\n\ |
6828 | in RTXs which aren't comparisons. E.g. the implementation is not\n\ |
6829 | allowed to swap operands in that case.\n\ |
6830 | \n\ |
6831 | GCC will not assume that the comparison resulting from this macro is\n\ |
6832 | valid but will see if the resulting insn matches a pattern in the\n\ |
6833 | @file{md} file.\n\ |
6834 | \n\ |
6835 | You need not to implement this hook if it would never change the\n\ |
6836 | comparison code or operands." , |
6837 | void, (int *code, rtx *op0, rtx *op1, bool op0_preserve_value), |
6838 | default_canonicalize_comparison) |
6839 | |
6840 | DEFHOOK |
6841 | (min_arithmetic_precision, |
6842 | "On some RISC architectures with 64-bit registers, the processor also\n\ |
6843 | maintains 32-bit condition codes that make it possible to do real 32-bit\n\ |
6844 | arithmetic, although the operations are performed on the full registers.\n\ |
6845 | \n\ |
6846 | On such architectures, defining this hook to 32 tells the compiler to try\n\ |
6847 | using 32-bit arithmetical operations setting the condition codes instead\n\ |
6848 | of doing full 64-bit arithmetic.\n\ |
6849 | \n\ |
6850 | More generally, define this hook on RISC architectures if you want the\n\ |
6851 | compiler to try using arithmetical operations setting the condition codes\n\ |
6852 | with a precision lower than the word precision.\n\ |
6853 | \n\ |
6854 | You need not define this hook if @code{WORD_REGISTER_OPERATIONS} is not\n\ |
6855 | defined to 1." , |
6856 | unsigned int, (void), default_min_arithmetic_precision) |
6857 | |
6858 | DEFHOOKPOD |
6859 | (atomic_test_and_set_trueval, |
6860 | "This value should be set if the result written by\n\ |
6861 | @code{atomic_test_and_set} is not exactly 1, i.e.@: the\n\ |
6862 | @code{bool} @code{true}." , |
6863 | unsigned char, 1) |
6864 | |
6865 | /* Return an unsigned int representing the alignment (in bits) of the atomic |
6866 | type which maps to machine MODE. This allows alignment to be overridden |
6867 | as needed. */ |
6868 | DEFHOOK |
6869 | (atomic_align_for_mode, |
6870 | "If defined, this function returns an appropriate alignment in bits for an\n\ |
6871 | atomic object of machine_mode @var{mode}. If 0 is returned then the\n\ |
6872 | default alignment for the specified mode is used." , |
6873 | unsigned int, (machine_mode mode), |
6874 | hook_uint_mode_0) |
6875 | |
6876 | DEFHOOK |
6877 | (atomic_assign_expand_fenv, |
6878 | "ISO C11 requires atomic compound assignments that may raise floating-point\n\ |
6879 | exceptions to raise exceptions corresponding to the arithmetic operation\n\ |
6880 | whose result was successfully stored in a compare-and-exchange sequence.\n\ |
6881 | This requires code equivalent to calls to @code{feholdexcept},\n\ |
6882 | @code{feclearexcept} and @code{feupdateenv} to be generated at\n\ |
6883 | appropriate points in the compare-and-exchange sequence. This hook should\n\ |
6884 | set @code{*@var{hold}} to an expression equivalent to the call to\n\ |
6885 | @code{feholdexcept}, @code{*@var{clear}} to an expression equivalent to\n\ |
6886 | the call to @code{feclearexcept} and @code{*@var{update}} to an expression\n\ |
6887 | equivalent to the call to @code{feupdateenv}. The three expressions are\n\ |
6888 | @code{NULL_TREE} on entry to the hook and may be left as @code{NULL_TREE}\n\ |
6889 | if no code is required in a particular place. The default implementation\n\ |
6890 | leaves all three expressions as @code{NULL_TREE}. The\n\ |
6891 | @code{__atomic_feraiseexcept} function from @code{libatomic} may be of use\n\ |
6892 | as part of the code generated in @code{*@var{update}}." , |
6893 | void, (tree *hold, tree *clear, tree *update), |
6894 | default_atomic_assign_expand_fenv) |
6895 | |
6896 | /* Leave the boolean fields at the end. */ |
6897 | |
6898 | /* True if we can create zeroed data by switching to a BSS section |
6899 | and then using ASM_OUTPUT_SKIP to allocate the space. */ |
6900 | DEFHOOKPOD |
6901 | (have_switchable_bss_sections, |
6902 | "This flag is true if we can create zeroed data by switching to a BSS\n\ |
6903 | section and then using @code{ASM_OUTPUT_SKIP} to allocate the space.\n\ |
6904 | This is true on most ELF targets." , |
6905 | bool, false) |
6906 | |
6907 | /* True if "native" constructors and destructors are supported, |
6908 | false if we're using collect2 for the job. */ |
6909 | DEFHOOKPOD |
6910 | (have_ctors_dtors, |
6911 | "This value is true if the target supports some ``native'' method of\n\ |
6912 | collecting constructors and destructors to be run at startup and exit.\n\ |
6913 | It is false if we must use @command{collect2}." , |
6914 | bool, false) |
6915 | |
6916 | /* True if the target wants DTORs to be run from cxa_atexit. */ |
6917 | DEFHOOKPOD |
6918 | (dtors_from_cxa_atexit, |
6919 | "This value is true if the target wants destructors to be queued to be\n\ |
6920 | run from __cxa_atexit. If this is the case then, for each priority level,\n\ |
6921 | a new constructor will be entered that registers the destructors for that\n\ |
6922 | level with __cxa_atexit (and there will be no destructors emitted).\n\ |
6923 | It is false the method implied by @code{have_ctors_dtors} is used." , |
6924 | bool, false) |
6925 | |
6926 | /* True if thread-local storage is supported. */ |
6927 | DEFHOOKPOD |
6928 | (have_tls, |
6929 | "Contains the value true if the target supports thread-local storage.\n\ |
6930 | The default value is false." , |
6931 | bool, false) |
6932 | |
6933 | /* True if a small readonly data section is supported. */ |
6934 | DEFHOOKPOD |
6935 | (have_srodata_section, |
6936 | "Contains the value true if the target places read-only\n\ |
6937 | ``small data'' into a separate section. The default value is false." , |
6938 | bool, false) |
6939 | |
6940 | /* True if EH frame info sections should be zero-terminated. */ |
6941 | DEFHOOKPOD |
6942 | (terminate_dw2_eh_frame_info, |
6943 | "Contains the value true if the target should add a zero word onto the\n\ |
6944 | end of a Dwarf-2 frame info section when used for exception handling.\n\ |
6945 | Default value is false if @code{EH_FRAME_SECTION_NAME} is defined, and\n\ |
6946 | true otherwise." , |
6947 | bool, true) |
6948 | |
6949 | /* True if #NO_APP should be emitted at the beginning of assembly output. */ |
6950 | DEFHOOKPOD |
6951 | (asm_file_start_app_off, |
6952 | "If this flag is true, the text of the macro @code{ASM_APP_OFF} will be\n\ |
6953 | printed as the very first line in the assembly file, unless\n\ |
6954 | @option{-fverbose-asm} is in effect. (If that macro has been defined\n\ |
6955 | to the empty string, this variable has no effect.) With the normal\n\ |
6956 | definition of @code{ASM_APP_OFF}, the effect is to notify the GNU\n\ |
6957 | assembler that it need not bother stripping comments or extra\n\ |
6958 | whitespace from its input. This allows it to work a bit faster.\n\ |
6959 | \n\ |
6960 | The default is false. You should not set it to true unless you have\n\ |
6961 | verified that your port does not generate any extra whitespace or\n\ |
6962 | comments that will cause GAS to issue errors in NO_APP mode." , |
6963 | bool, false) |
6964 | |
6965 | /* True if output_file_directive should be called for main_input_filename |
6966 | at the beginning of assembly output. */ |
6967 | DEFHOOKPOD |
6968 | (asm_file_start_file_directive, |
6969 | "If this flag is true, @code{output_file_directive} will be called\n\ |
6970 | for the primary source file, immediately after printing\n\ |
6971 | @code{ASM_APP_OFF} (if that is enabled). Most ELF assemblers expect\n\ |
6972 | this to be done. The default is false." , |
6973 | bool, false) |
6974 | |
6975 | /* Returns true if we should generate exception tables for use with the |
6976 | ARM EABI. The effects the encoding of function exception specifications. */ |
6977 | DEFHOOKPOD |
6978 | (arm_eabi_unwinder, |
6979 | "This flag should be set to @code{true} on targets that use an ARM EABI\n\ |
6980 | based unwinding library, and @code{false} on other targets. This effects\n\ |
6981 | the format of unwinding tables, and how the unwinder in entered after\n\ |
6982 | running a cleanup. The default is @code{false}." , |
6983 | bool, false) |
6984 | |
6985 | DEFHOOKPOD |
6986 | (want_debug_pub_sections, |
6987 | "True if the @code{.debug_pubtypes} and @code{.debug_pubnames} sections\n\ |
6988 | should be emitted. These sections are not used on most platforms, and\n\ |
6989 | in particular GDB does not use them." , |
6990 | bool, false) |
6991 | |
6992 | DEFHOOKPOD |
6993 | (delay_sched2, |
6994 | "True if sched2 is not to be run at its normal place.\n\ |
6995 | This usually means it will be run as part of machine-specific reorg." , |
6996 | bool, false) |
6997 | |
6998 | DEFHOOKPOD |
6999 | (delay_vartrack, |
7000 | "True if vartrack is not to be run at its normal place.\n\ |
7001 | This usually means it will be run as part of machine-specific reorg." , |
7002 | bool, false) |
7003 | |
7004 | DEFHOOKPOD |
7005 | (no_register_allocation, |
7006 | "True if register allocation and the passes\n\ |
7007 | following it should not be run. Usually true only for virtual assembler\n\ |
7008 | targets." , |
7009 | bool, false) |
7010 | |
7011 | /* Leave the boolean fields at the end. */ |
7012 | |
7013 | /* Functions related to mode switching. */ |
7014 | #undef HOOK_PREFIX |
7015 | #define HOOK_PREFIX "TARGET_MODE_" |
7016 | HOOK_VECTOR (TARGET_TOGGLE_, mode_switching) |
7017 | |
7018 | DEFHOOK |
7019 | (emit, |
7020 | "Generate one or more insns to set @var{entity} to @var{mode}.\n\ |
7021 | @var{hard_reg_live} is the set of hard registers live at the point where\n\ |
7022 | the insn(s) are to be inserted. @var{prev_moxde} indicates the mode\n\ |
7023 | to switch from. Sets of a lower numbered entity will be emitted before\n\ |
7024 | sets of a higher numbered entity to a mode of the same or lower priority." , |
7025 | void, (int entity, int mode, int prev_mode, HARD_REG_SET regs_live), NULL) |
7026 | |
7027 | DEFHOOK |
7028 | (needed, |
7029 | "@var{entity} is an integer specifying a mode-switched entity.\n\ |
7030 | If @code{OPTIMIZE_MODE_SWITCHING} is defined, you must define this macro\n\ |
7031 | to return an integer value not larger than the corresponding element\n\ |
7032 | in @code{NUM_MODES_FOR_MODE_SWITCHING}, to denote the mode that @var{entity}\n\ |
7033 | must be switched into prior to the execution of @var{insn}." , |
7034 | int, (int entity, rtx_insn *insn), NULL) |
7035 | |
7036 | DEFHOOK |
7037 | (after, |
7038 | "@var{entity} is an integer specifying a mode-switched entity.\n\ |
7039 | If this macro is defined, it is evaluated for every @var{insn} during mode\n\ |
7040 | switching. It determines the mode that an insn results\n\ |
7041 | in (if different from the incoming mode)." , |
7042 | int, (int entity, int mode, rtx_insn *insn), NULL) |
7043 | |
7044 | DEFHOOK |
7045 | (entry, |
7046 | "If this macro is defined, it is evaluated for every @var{entity} that\n\ |
7047 | needs mode switching. It should evaluate to an integer, which is a mode\n\ |
7048 | that @var{entity} is assumed to be switched to at function entry.\n\ |
7049 | If @code{TARGET_MODE_ENTRY} is defined then @code{TARGET_MODE_EXIT}\n\ |
7050 | must be defined." , |
7051 | int, (int entity), NULL) |
7052 | |
7053 | DEFHOOK |
7054 | (exit, |
7055 | "If this macro is defined, it is evaluated for every @var{entity} that\n\ |
7056 | needs mode switching. It should evaluate to an integer, which is a mode\n\ |
7057 | that @var{entity} is assumed to be switched to at function exit.\n\ |
7058 | If @code{TARGET_MODE_EXIT} is defined then @code{TARGET_MODE_ENTRY}\n\ |
7059 | must be defined." , |
7060 | int, (int entity), NULL) |
7061 | |
7062 | DEFHOOK |
7063 | (priority, |
7064 | "This macro specifies the order in which modes for @var{entity}\n\ |
7065 | are processed. 0 is the highest priority,\n\ |
7066 | @code{NUM_MODES_FOR_MODE_SWITCHING[@var{entity}] - 1} the lowest.\n\ |
7067 | The value of the macro should be an integer designating a mode\n\ |
7068 | for @var{entity}. For any fixed @var{entity}, @code{mode_priority}\n\ |
7069 | (@var{entity}, @var{n}) shall be a bijection in 0 @dots{}\n\ |
7070 | @code{num_modes_for_mode_switching[@var{entity}] - 1}." , |
7071 | int, (int entity, int n), NULL) |
7072 | |
7073 | HOOK_VECTOR_END (mode_switching) |
7074 | |
7075 | #undef HOOK_PREFIX |
7076 | #define HOOK_PREFIX "TARGET_MEMTAG_" |
7077 | HOOK_VECTOR (TARGET_MEMTAG_, memtag) |
7078 | |
7079 | DEFHOOK |
7080 | (can_tag_addresses, |
7081 | "True if the backend architecture naturally supports ignoring some region\n\ |
7082 | of pointers. This feature means that @option{-fsanitize=hwaddress} can\n\ |
7083 | work.\n\ |
7084 | \n\ |
7085 | At preset, this feature does not support address spaces. It also requires\n\ |
7086 | @code{Pmode} to be the same as @code{ptr_mode}." , |
7087 | bool, (), default_memtag_can_tag_addresses) |
7088 | |
7089 | DEFHOOK |
7090 | (tag_size, |
7091 | "Return the size of a tag (in bits) for this platform.\n\ |
7092 | \n\ |
7093 | The default returns 8." , |
7094 | uint8_t, (), default_memtag_tag_size) |
7095 | |
7096 | DEFHOOK |
7097 | (granule_size, |
7098 | "Return the size in real memory that each byte in shadow memory refers to.\n\ |
7099 | I.e. if a variable is @var{X} bytes long in memory, then this hook should\n\ |
7100 | return the value @var{Y} such that the tag in shadow memory spans\n\ |
7101 | @var{X}/@var{Y} bytes.\n\ |
7102 | \n\ |
7103 | Most variables will need to be aligned to this amount since two variables\n\ |
7104 | that are neighbors in memory and share a tag granule would need to share\n\ |
7105 | the same tag.\n\ |
7106 | \n\ |
7107 | The default returns 16." , |
7108 | uint8_t, (), default_memtag_granule_size) |
7109 | |
7110 | DEFHOOK |
7111 | (insert_random_tag, |
7112 | "Return an RTX representing the value of @var{untagged} but with a\n\ |
7113 | (possibly) random tag in it.\n\ |
7114 | Put that value into @var{target} if it is convenient to do so.\n\ |
7115 | This function is used to generate a tagged base for the current stack frame." , |
7116 | rtx, (rtx untagged, rtx target), default_memtag_insert_random_tag) |
7117 | |
7118 | DEFHOOK |
7119 | (add_tag, |
7120 | "Return an RTX that represents the result of adding @var{addr_offset} to\n\ |
7121 | the address in pointer @var{base} and @var{tag_offset} to the tag in pointer\n\ |
7122 | @var{base}.\n\ |
7123 | The resulting RTX must either be a valid memory address or be able to get\n\ |
7124 | put into an operand with @code{force_operand}.\n\ |
7125 | \n\ |
7126 | Unlike other memtag hooks, this must return an expression and not emit any\n\ |
7127 | RTL." , |
7128 | rtx, (rtx base, poly_int64 addr_offset, uint8_t tag_offset), |
7129 | default_memtag_add_tag) |
7130 | |
7131 | DEFHOOK |
7132 | (set_tag, |
7133 | "Return an RTX representing @var{untagged_base} but with the tag @var{tag}.\n\ |
7134 | Try and store this in @var{target} if convenient.\n\ |
7135 | @var{untagged_base} is required to have a zero tag when this hook is called.\n\ |
7136 | The default of this hook is to set the top byte of @var{untagged_base} to\n\ |
7137 | @var{tag}." , |
7138 | rtx, (rtx untagged_base, rtx tag, rtx target), default_memtag_set_tag) |
7139 | |
7140 | DEFHOOK |
7141 | (, |
7142 | "Return an RTX representing the tag stored in @var{tagged_pointer}.\n\ |
7143 | Store the result in @var{target} if it is convenient.\n\ |
7144 | The default represents the top byte of the original pointer." , |
7145 | rtx, (rtx tagged_pointer, rtx target), default_memtag_extract_tag) |
7146 | |
7147 | DEFHOOK |
7148 | (untagged_pointer, |
7149 | "Return an RTX representing @var{tagged_pointer} with its tag set to zero.\n\ |
7150 | Store the result in @var{target} if convenient.\n\ |
7151 | The default clears the top byte of the original pointer." , |
7152 | rtx, (rtx tagged_pointer, rtx target), default_memtag_untagged_pointer) |
7153 | |
7154 | HOOK_VECTOR_END (memtag) |
7155 | #undef HOOK_PREFIX |
7156 | #define HOOK_PREFIX "TARGET_" |
7157 | |
7158 | #define DEF_TARGET_INSN(NAME, PROTO) \ |
7159 | DEFHOOK_UNDOC (have_##NAME, "", bool, (void), false) |
7160 | #include "target-insns.def" |
7161 | #undef DEF_TARGET_INSN |
7162 | |
7163 | #define DEF_TARGET_INSN(NAME, PROTO) \ |
7164 | DEFHOOK_UNDOC (gen_##NAME, "", rtx_insn *, PROTO, NULL) |
7165 | #include "target-insns.def" |
7166 | #undef DEF_TARGET_INSN |
7167 | |
7168 | #define DEF_TARGET_INSN(NAME, PROTO) \ |
7169 | DEFHOOKPOD (code_for_##NAME, "*", enum insn_code, CODE_FOR_nothing) |
7170 | #include "target-insns.def" |
7171 | #undef DEF_TARGET_INSN |
7172 | |
7173 | DEFHOOK |
7174 | (run_target_selftests, |
7175 | "If selftests are enabled, run any selftests for this target." , |
7176 | void, (void), |
7177 | NULL) |
7178 | |
7179 | DEFHOOK |
7180 | (gcov_type_size, |
7181 | "Returns the gcov type size in bits. This type is used for example for\n\ |
7182 | counters incremented by profiling and code-coverage events. The default\n\ |
7183 | value is 64, if the type size of long long is greater than 32, otherwise the\n\ |
7184 | default value is 32. A 64-bit type is recommended to avoid overflows of the\n\ |
7185 | counters. If the @option{-fprofile-update=atomic} is used, then the\n\ |
7186 | counters are incremented using atomic operations. Targets not supporting\n\ |
7187 | 64-bit atomic operations may override the default value and request a 32-bit\n\ |
7188 | type." , |
7189 | HOST_WIDE_INT, (void), default_gcov_type_size) |
7190 | |
7191 | /* This value represents whether the shadow call stack is implemented on |
7192 | the target platform. */ |
7193 | DEFHOOKPOD |
7194 | (have_shadow_call_stack, |
7195 | "This value is true if the target platform supports\n\ |
7196 | @option{-fsanitize=shadow-call-stack}. The default value is false." , |
7197 | bool, false) |
7198 | |
7199 | /* Close the 'struct gcc_target' definition. */ |
7200 | HOOK_VECTOR_END (C90_EMPTY_HACK) |
7201 | |
7202 | |