1/* Definitions for code generation pass of GNU compiler.
2 Copyright (C) 1987-2023 Free Software Foundation, Inc.
3
4This file is part of GCC.
5
6GCC is free software; you can redistribute it and/or modify it under
7the terms of the GNU General Public License as published by the Free
8Software Foundation; either version 3, or (at your option) any later
9version.
10
11GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12WARRANTY; without even the implied warranty of MERCHANTABILITY or
13FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14for more details.
15
16You should have received a copy of the GNU General Public License
17along with GCC; see the file COPYING3. If not see
18<http://www.gnu.org/licenses/>. */
19
20#ifndef GCC_EXPR_H
21#define GCC_EXPR_H
22
23/* This is the 4th arg to `expand_expr'.
24 EXPAND_STACK_PARM means we are possibly expanding a call param onto
25 the stack.
26 EXPAND_SUM means it is ok to return a PLUS rtx or MULT rtx.
27 EXPAND_INITIALIZER is similar but also record any labels on forced_labels.
28 EXPAND_CONST_ADDRESS means it is ok to return a MEM whose address
29 is a constant that is not a legitimate address.
30 EXPAND_WRITE means we are only going to write to the resulting rtx.
31 EXPAND_MEMORY means we are interested in a memory result, even if
32 the memory is constant and we could have propagated a constant value,
33 or the memory is unaligned on a STRICT_ALIGNMENT target. */
34enum expand_modifier {EXPAND_NORMAL = 0, EXPAND_STACK_PARM, EXPAND_SUM,
35 EXPAND_CONST_ADDRESS, EXPAND_INITIALIZER, EXPAND_WRITE,
36 EXPAND_MEMORY};
37
38/* Prevent the compiler from deferring stack pops. See
39 inhibit_defer_pop for more information. */
40#define NO_DEFER_POP (inhibit_defer_pop += 1)
41
42/* Allow the compiler to defer stack pops. See inhibit_defer_pop for
43 more information. */
44#define OK_DEFER_POP (inhibit_defer_pop -= 1)
45
46/* This structure is used to pass around information about exploded
47 unary, binary and trinary expressions between expand_expr_real_1 and
48 friends. */
49typedef struct separate_ops
50{
51 enum tree_code code;
52 location_t location;
53 tree type;
54 tree op0, op1, op2;
55} *sepops;
56
57/* This is run during target initialization to set up which modes can be
58 used directly in memory and to initialize the block move optab. */
59extern void init_expr_target (void);
60
61/* This is run at the start of compiling a function. */
62extern void init_expr (void);
63
64/* Emit some rtl insns to move data between rtx's, converting machine modes.
65 Both modes must be floating or both fixed. */
66extern void convert_move (rtx, rtx, int);
67
68/* Convert an rtx to specified machine mode and return the result. */
69extern rtx convert_to_mode (machine_mode, rtx, int);
70
71/* Convert an rtx to MODE from OLDMODE and return the result. */
72extern rtx convert_modes (machine_mode mode, machine_mode oldmode,
73 rtx x, int unsignedp);
74
75/* Variant of convert_modes for ABI parameter passing/return. */
76extern rtx convert_float_to_wider_int (machine_mode mode, machine_mode fmode,
77 rtx x);
78
79/* Variant of convert_modes for ABI parameter passing/return. */
80extern rtx convert_wider_int_to_float (machine_mode mode, machine_mode imode,
81 rtx x);
82
83/* Expand a call to memcpy or memmove or memcmp, and return the result. */
84extern rtx emit_block_op_via_libcall (enum built_in_function, rtx, rtx, rtx,
85 bool);
86
87inline rtx
88emit_block_copy_via_libcall (rtx dst, rtx src, rtx size, bool tailcall = false)
89{
90 return emit_block_op_via_libcall (BUILT_IN_MEMCPY, dst, src, size, tailcall);
91}
92
93inline rtx
94emit_block_move_via_libcall (rtx dst, rtx src, rtx size, bool tailcall = false)
95{
96 return emit_block_op_via_libcall (BUILT_IN_MEMMOVE, dst, src, size, tailcall);
97}
98
99inline rtx
100emit_block_comp_via_libcall (rtx dst, rtx src, rtx size, bool tailcall = false)
101{
102 return emit_block_op_via_libcall (BUILT_IN_MEMCMP, dst, src, size, tailcall);
103}
104
105/* Emit code to move a block Y to a block X. */
106enum block_op_methods
107{
108 BLOCK_OP_NORMAL,
109 BLOCK_OP_NO_LIBCALL,
110 BLOCK_OP_CALL_PARM,
111 /* Like BLOCK_OP_NORMAL, but the libcall can be tail call optimized. */
112 BLOCK_OP_TAILCALL,
113 /* Like BLOCK_OP_NO_LIBCALL, but instead of emitting a libcall return
114 pc_rtx to indicate nothing has been emitted and let the caller handle
115 it. */
116 BLOCK_OP_NO_LIBCALL_RET
117};
118
119typedef rtx (*by_pieces_constfn) (void *, void *, HOST_WIDE_INT,
120 fixed_size_mode);
121
122/* The second pointer passed to by_pieces_constfn. */
123struct by_pieces_prev
124{
125 rtx data;
126 fixed_size_mode mode;
127};
128
129extern rtx emit_block_move (rtx, rtx, rtx, enum block_op_methods);
130extern rtx emit_block_move_hints (rtx, rtx, rtx, enum block_op_methods,
131 unsigned int, HOST_WIDE_INT,
132 unsigned HOST_WIDE_INT,
133 unsigned HOST_WIDE_INT,
134 unsigned HOST_WIDE_INT,
135 bool bail_out_libcall = false,
136 bool *is_move_done = NULL,
137 bool might_overlap = false);
138extern rtx emit_block_cmp_hints (rtx, rtx, rtx, tree, rtx, bool,
139 by_pieces_constfn, void *);
140extern bool emit_storent_insn (rtx to, rtx from);
141
142/* Copy all or part of a value X into registers starting at REGNO.
143 The number of registers to be filled is NREGS. */
144extern void move_block_to_reg (int, rtx, int, machine_mode);
145
146/* Copy all or part of a BLKmode value X out of registers starting at REGNO.
147 The number of registers to be filled is NREGS. */
148extern void move_block_from_reg (int, rtx, int);
149
150/* Generate a non-consecutive group of registers represented by a PARALLEL. */
151extern rtx gen_group_rtx (rtx);
152
153/* Load a BLKmode value into non-consecutive registers represented by a
154 PARALLEL. */
155extern void emit_group_load (rtx, rtx, tree, poly_int64);
156
157/* Similarly, but load into new temporaries. */
158extern rtx emit_group_load_into_temps (rtx, rtx, tree, poly_int64);
159
160/* Move a non-consecutive group of registers represented by a PARALLEL into
161 a non-consecutive group of registers represented by a PARALLEL. */
162extern void emit_group_move (rtx, rtx);
163
164/* Move a group of registers represented by a PARALLEL into pseudos. */
165extern rtx emit_group_move_into_temps (rtx);
166
167/* Store a BLKmode value from non-consecutive registers represented by a
168 PARALLEL. */
169extern void emit_group_store (rtx, rtx, tree, poly_int64);
170
171extern rtx maybe_emit_group_store (rtx, tree);
172
173/* Mark REG as holding a parameter for the next CALL_INSN.
174 Mode is TYPE_MODE of the non-promoted parameter, or VOIDmode. */
175extern void use_reg_mode (rtx *, rtx, machine_mode);
176extern void clobber_reg_mode (rtx *, rtx, machine_mode);
177
178extern rtx copy_blkmode_to_reg (machine_mode, tree);
179
180/* Mark REG as holding a parameter for the next CALL_INSN. */
181inline void
182use_reg (rtx *fusage, rtx reg)
183{
184 use_reg_mode (fusage, reg, VOIDmode);
185}
186
187/* Mark REG as clobbered by the call with FUSAGE as CALL_INSN_FUNCTION_USAGE. */
188inline void
189clobber_reg (rtx *fusage, rtx reg)
190{
191 clobber_reg_mode (fusage, reg, VOIDmode);
192}
193
194/* Mark NREGS consecutive regs, starting at REGNO, as holding parameters
195 for the next CALL_INSN. */
196extern void use_regs (rtx *, int, int);
197
198/* Mark a PARALLEL as holding a parameter for the next CALL_INSN. */
199extern void use_group_regs (rtx *, rtx);
200
201#ifdef GCC_INSN_CODES_H
202extern rtx expand_cmpstrn_or_cmpmem (insn_code, rtx, rtx, rtx, tree, rtx,
203 HOST_WIDE_INT);
204#endif
205
206/* Write zeros through the storage of OBJECT.
207 If OBJECT has BLKmode, SIZE is its length in bytes. */
208extern rtx clear_storage (rtx, rtx, enum block_op_methods);
209extern rtx clear_storage_hints (rtx, rtx, enum block_op_methods,
210 unsigned int, HOST_WIDE_INT,
211 unsigned HOST_WIDE_INT,
212 unsigned HOST_WIDE_INT,
213 unsigned HOST_WIDE_INT,
214 unsigned);
215/* The same, but always output an library call. */
216extern rtx set_storage_via_libcall (rtx, rtx, rtx, bool = false);
217
218/* Expand a setmem pattern; return true if successful. */
219extern bool set_storage_via_setmem (rtx, rtx, rtx, unsigned int,
220 unsigned int, HOST_WIDE_INT,
221 unsigned HOST_WIDE_INT,
222 unsigned HOST_WIDE_INT,
223 unsigned HOST_WIDE_INT);
224
225/* Return true if it is desirable to store LEN bytes generated by
226 CONSTFUN with several move instructions by store_by_pieces
227 function. CONSTFUNDATA is a pointer which will be passed as argument
228 in every CONSTFUN call.
229 ALIGN is maximum alignment we can assume.
230 MEMSETP is true if this is a real memset/bzero, not a copy
231 of a const string. */
232extern bool can_store_by_pieces (unsigned HOST_WIDE_INT,
233 by_pieces_constfn,
234 void *, unsigned int, bool);
235
236/* Generate several move instructions to store LEN bytes generated by
237 CONSTFUN to block TO. (A MEM rtx with BLKmode). CONSTFUNDATA is a
238 pointer which will be passed as argument in every CONSTFUN call.
239 ALIGN is maximum alignment we can assume.
240 MEMSETP is true if this is a real memset/bzero, not a copy.
241 Returns TO + LEN. */
242extern rtx store_by_pieces (rtx, unsigned HOST_WIDE_INT, by_pieces_constfn,
243 void *, unsigned int, bool, memop_ret);
244
245/* If can_store_by_pieces passes for worst-case values near MAX_LEN, call
246 store_by_pieces within conditionals so as to handle variable LEN efficiently,
247 storing VAL, if non-NULL_RTX, or valc instead. */
248extern bool try_store_by_multiple_pieces (rtx to, rtx len,
249 unsigned int ctz_len,
250 unsigned HOST_WIDE_INT min_len,
251 unsigned HOST_WIDE_INT max_len,
252 rtx val, char valc,
253 unsigned int align);
254
255/* Emit insns to set X from Y. */
256extern rtx_insn *emit_move_insn (rtx, rtx);
257extern rtx_insn *gen_move_insn (rtx, rtx);
258
259/* Emit insns to set X from Y, with no frills. */
260extern rtx_insn *emit_move_insn_1 (rtx, rtx);
261
262extern rtx_insn *emit_move_complex_push (machine_mode, rtx, rtx);
263extern rtx_insn *emit_move_complex_parts (rtx, rtx);
264extern rtx read_complex_part (rtx, bool);
265extern void write_complex_part (rtx, rtx, bool, bool);
266extern rtx read_complex_part (rtx, bool);
267extern rtx emit_move_resolve_push (machine_mode, rtx);
268
269/* Push a block of length SIZE (perhaps variable)
270 and return an rtx to address the beginning of the block. */
271extern rtx push_block (rtx, poly_int64, int);
272
273/* Generate code to push something onto the stack, given its mode and type. */
274extern bool emit_push_insn (rtx, machine_mode, tree, rtx, unsigned int,
275 int, rtx, poly_int64, rtx, rtx, int, rtx, bool);
276
277/* Extract the accessible bit-range from a COMPONENT_REF. */
278extern void get_bit_range (poly_uint64 *, poly_uint64 *, tree,
279 poly_int64 *, tree *);
280
281/* Expand an assignment that stores the value of FROM into TO. */
282extern void expand_assignment (tree, tree, bool);
283
284/* Generate code for computing expression EXP,
285 and storing the value into TARGET.
286 If SUGGEST_REG is nonzero, copy the value through a register
287 and return that register, if that is possible. */
288extern rtx store_expr (tree, rtx, int, bool, bool);
289
290/* Given an rtx that may include add and multiply operations,
291 generate them as insns and return a pseudo-reg containing the value.
292 Useful after calling expand_expr with 1 as sum_ok. */
293extern rtx force_operand (rtx, rtx);
294
295/* Work horses for expand_expr. */
296extern rtx expand_expr_real (tree, rtx, machine_mode,
297 enum expand_modifier, rtx *, bool);
298extern rtx expand_expr_real_1 (tree, rtx, machine_mode,
299 enum expand_modifier, rtx *, bool);
300extern rtx expand_expr_real_2 (sepops, rtx, machine_mode,
301 enum expand_modifier);
302
303/* Generate code for computing expression EXP.
304 An rtx for the computed value is returned. The value is never null.
305 In the case of a void EXP, const0_rtx is returned. */
306inline rtx
307expand_expr (tree exp, rtx target, machine_mode mode,
308 enum expand_modifier modifier)
309{
310 return expand_expr_real (exp, target, mode, modifier, NULL, false);
311}
312
313inline rtx
314expand_normal (tree exp)
315{
316 return expand_expr_real (exp, NULL_RTX, VOIDmode, EXPAND_NORMAL, NULL, false);
317}
318
319
320/* Return STRING_CST and set offset, size and decl, if the first
321 argument corresponds to a string constant. */
322extern tree string_constant (tree, tree *, tree *, tree *);
323/* Similar to string_constant, return a STRING_CST corresponding
324 to the value representation of the first argument if it's
325 a constant. */
326extern tree byte_representation (tree, tree *, tree *, tree *);
327
328extern enum tree_code maybe_optimize_mod_cmp (enum tree_code, tree *, tree *);
329extern void maybe_optimize_sub_cmp_0 (enum tree_code, tree *, tree *);
330
331/* Two different ways of generating switch statements. */
332extern bool try_casesi (tree, tree, tree, tree, rtx, rtx, rtx,
333 profile_probability);
334extern bool try_tablejump (tree, tree, tree, tree, rtx, rtx,
335 profile_probability);
336
337extern bool safe_from_p (const_rtx, tree, int);
338
339/* Get the personality libfunc for a function decl. */
340rtx get_personality_function (tree);
341
342/* Determine whether the LEN bytes can be moved by using several move
343 instructions. Return nonzero if a call to move_by_pieces should
344 succeed. */
345extern bool can_move_by_pieces (unsigned HOST_WIDE_INT, unsigned int);
346
347extern unsigned HOST_WIDE_INT highest_pow2_factor (const_tree);
348
349extern bool categorize_ctor_elements (const_tree, HOST_WIDE_INT *,
350 HOST_WIDE_INT *, HOST_WIDE_INT *,
351 bool *);
352extern bool immediate_const_ctor_p (const_tree, unsigned int words = 1);
353extern void store_constructor (tree, rtx, int, poly_int64, bool);
354extern HOST_WIDE_INT int_expr_size (const_tree exp);
355
356extern void expand_operands (tree, tree, rtx, rtx*, rtx*,
357 enum expand_modifier);
358
359/* rtl.h and tree.h were included. */
360/* Return an rtx for the size in bytes of the value of an expr. */
361extern rtx expr_size (tree);
362
363extern bool mem_ref_refers_to_non_mem_p (tree);
364extern bool non_mem_decl_p (tree);
365
366#endif /* GCC_EXPR_H */
367

source code of gcc/expr.h