1/* Conditional constant propagation pass for the GNU compiler.
2 Copyright (C) 2000-2017 Free Software Foundation, Inc.
3 Adapted from original RTL SSA-CCP by Daniel Berlin <dberlin@dberlin.org>
4 Adapted to GIMPLE trees by Diego Novillo <dnovillo@redhat.com>
5
6This file is part of GCC.
7
8GCC is free software; you can redistribute it and/or modify it
9under the terms of the GNU General Public License as published by the
10Free Software Foundation; either version 3, or (at your option) any
11later version.
12
13GCC is distributed in the hope that it will be useful, but WITHOUT
14ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
15FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16for more details.
17
18You should have received a copy of the GNU General Public License
19along with GCC; see the file COPYING3. If not see
20<http://www.gnu.org/licenses/>. */
21
22/* Conditional constant propagation (CCP) is based on the SSA
23 propagation engine (tree-ssa-propagate.c). Constant assignments of
24 the form VAR = CST are propagated from the assignments into uses of
25 VAR, which in turn may generate new constants. The simulation uses
26 a four level lattice to keep track of constant values associated
27 with SSA names. Given an SSA name V_i, it may take one of the
28 following values:
29
30 UNINITIALIZED -> the initial state of the value. This value
31 is replaced with a correct initial value
32 the first time the value is used, so the
33 rest of the pass does not need to care about
34 it. Using this value simplifies initialization
35 of the pass, and prevents us from needlessly
36 scanning statements that are never reached.
37
38 UNDEFINED -> V_i is a local variable whose definition
39 has not been processed yet. Therefore we
40 don't yet know if its value is a constant
41 or not.
42
43 CONSTANT -> V_i has been found to hold a constant
44 value C.
45
46 VARYING -> V_i cannot take a constant value, or if it
47 does, it is not possible to determine it
48 at compile time.
49
50 The core of SSA-CCP is in ccp_visit_stmt and ccp_visit_phi_node:
51
52 1- In ccp_visit_stmt, we are interested in assignments whose RHS
53 evaluates into a constant and conditional jumps whose predicate
54 evaluates into a boolean true or false. When an assignment of
55 the form V_i = CONST is found, V_i's lattice value is set to
56 CONSTANT and CONST is associated with it. This causes the
57 propagation engine to add all the SSA edges coming out the
58 assignment into the worklists, so that statements that use V_i
59 can be visited.
60
61 If the statement is a conditional with a constant predicate, we
62 mark the outgoing edges as executable or not executable
63 depending on the predicate's value. This is then used when
64 visiting PHI nodes to know when a PHI argument can be ignored.
65
66
67 2- In ccp_visit_phi_node, if all the PHI arguments evaluate to the
68 same constant C, then the LHS of the PHI is set to C. This
69 evaluation is known as the "meet operation". Since one of the
70 goals of this evaluation is to optimistically return constant
71 values as often as possible, it uses two main short cuts:
72
73 - If an argument is flowing in through a non-executable edge, it
74 is ignored. This is useful in cases like this:
75
76 if (PRED)
77 a_9 = 3;
78 else
79 a_10 = 100;
80 a_11 = PHI (a_9, a_10)
81
82 If PRED is known to always evaluate to false, then we can
83 assume that a_11 will always take its value from a_10, meaning
84 that instead of consider it VARYING (a_9 and a_10 have
85 different values), we can consider it CONSTANT 100.
86
87 - If an argument has an UNDEFINED value, then it does not affect
88 the outcome of the meet operation. If a variable V_i has an
89 UNDEFINED value, it means that either its defining statement
90 hasn't been visited yet or V_i has no defining statement, in
91 which case the original symbol 'V' is being used
92 uninitialized. Since 'V' is a local variable, the compiler
93 may assume any initial value for it.
94
95
96 After propagation, every variable V_i that ends up with a lattice
97 value of CONSTANT will have the associated constant value in the
98 array CONST_VAL[i].VALUE. That is fed into substitute_and_fold for
99 final substitution and folding.
100
101 This algorithm uses wide-ints at the max precision of the target.
102 This means that, with one uninteresting exception, variables with
103 UNSIGNED types never go to VARYING because the bits above the
104 precision of the type of the variable are always zero. The
105 uninteresting case is a variable of UNSIGNED type that has the
106 maximum precision of the target. Such variables can go to VARYING,
107 but this causes no loss of infomation since these variables will
108 never be extended.
109
110 References:
111
112 Constant propagation with conditional branches,
113 Wegman and Zadeck, ACM TOPLAS 13(2):181-210.
114
115 Building an Optimizing Compiler,
116 Robert Morgan, Butterworth-Heinemann, 1998, Section 8.9.
117
118 Advanced Compiler Design and Implementation,
119 Steven Muchnick, Morgan Kaufmann, 1997, Section 12.6 */
120
121#include "config.h"
122#include "system.h"
123#include "coretypes.h"
124#include "backend.h"
125#include "target.h"
126#include "tree.h"
127#include "gimple.h"
128#include "tree-pass.h"
129#include "ssa.h"
130#include "gimple-pretty-print.h"
131#include "fold-const.h"
132#include "gimple-fold.h"
133#include "tree-eh.h"
134#include "gimplify.h"
135#include "gimple-iterator.h"
136#include "tree-cfg.h"
137#include "tree-ssa-propagate.h"
138#include "dbgcnt.h"
139#include "params.h"
140#include "builtins.h"
141#include "tree-chkp.h"
142#include "cfgloop.h"
143#include "stor-layout.h"
144#include "optabs-query.h"
145#include "tree-ssa-ccp.h"
146#include "tree-dfa.h"
147#include "diagnostic-core.h"
148#include "stringpool.h"
149#include "attribs.h"
150#include "tree-vector-builder.h"
151
152/* Possible lattice values. */
153typedef enum
154{
155 UNINITIALIZED,
156 UNDEFINED,
157 CONSTANT,
158 VARYING
159} ccp_lattice_t;
160
161struct ccp_prop_value_t {
162 /* Lattice value. */
163 ccp_lattice_t lattice_val;
164
165 /* Propagated value. */
166 tree value;
167
168 /* Mask that applies to the propagated value during CCP. For X
169 with a CONSTANT lattice value X & ~mask == value & ~mask. The
170 zero bits in the mask cover constant values. The ones mean no
171 information. */
172 widest_int mask;
173};
174
175class ccp_propagate : public ssa_propagation_engine
176{
177 public:
178 enum ssa_prop_result visit_stmt (gimple *, edge *, tree *) FINAL OVERRIDE;
179 enum ssa_prop_result visit_phi (gphi *) FINAL OVERRIDE;
180};
181
182/* Array of propagated constant values. After propagation,
183 CONST_VAL[I].VALUE holds the constant value for SSA_NAME(I). If
184 the constant is held in an SSA name representing a memory store
185 (i.e., a VDEF), CONST_VAL[I].MEM_REF will contain the actual
186 memory reference used to store (i.e., the LHS of the assignment
187 doing the store). */
188static ccp_prop_value_t *const_val;
189static unsigned n_const_val;
190
191static void canonicalize_value (ccp_prop_value_t *);
192static void ccp_lattice_meet (ccp_prop_value_t *, ccp_prop_value_t *);
193
194/* Dump constant propagation value VAL to file OUTF prefixed by PREFIX. */
195
196static void
197dump_lattice_value (FILE *outf, const char *prefix, ccp_prop_value_t val)
198{
199 switch (val.lattice_val)
200 {
201 case UNINITIALIZED:
202 fprintf (outf, "%sUNINITIALIZED", prefix);
203 break;
204 case UNDEFINED:
205 fprintf (outf, "%sUNDEFINED", prefix);
206 break;
207 case VARYING:
208 fprintf (outf, "%sVARYING", prefix);
209 break;
210 case CONSTANT:
211 if (TREE_CODE (val.value) != INTEGER_CST
212 || val.mask == 0)
213 {
214 fprintf (outf, "%sCONSTANT ", prefix);
215 print_generic_expr (outf, val.value, dump_flags);
216 }
217 else
218 {
219 widest_int cval = wi::bit_and_not (wi::to_widest (val.value),
220 val.mask);
221 fprintf (outf, "%sCONSTANT ", prefix);
222 print_hex (cval, outf);
223 fprintf (outf, " (");
224 print_hex (val.mask, outf);
225 fprintf (outf, ")");
226 }
227 break;
228 default:
229 gcc_unreachable ();
230 }
231}
232
233
234/* Print lattice value VAL to stderr. */
235
236void debug_lattice_value (ccp_prop_value_t val);
237
238DEBUG_FUNCTION void
239debug_lattice_value (ccp_prop_value_t val)
240{
241 dump_lattice_value (stderr, "", val);
242 fprintf (stderr, "\n");
243}
244
245/* Extend NONZERO_BITS to a full mask, based on sgn. */
246
247static widest_int
248extend_mask (const wide_int &nonzero_bits, signop sgn)
249{
250 return widest_int::from (nonzero_bits, sgn);
251}
252
253/* Compute a default value for variable VAR and store it in the
254 CONST_VAL array. The following rules are used to get default
255 values:
256
257 1- Global and static variables that are declared constant are
258 considered CONSTANT.
259
260 2- Any other value is considered UNDEFINED. This is useful when
261 considering PHI nodes. PHI arguments that are undefined do not
262 change the constant value of the PHI node, which allows for more
263 constants to be propagated.
264
265 3- Variables defined by statements other than assignments and PHI
266 nodes are considered VARYING.
267
268 4- Initial values of variables that are not GIMPLE registers are
269 considered VARYING. */
270
271static ccp_prop_value_t
272get_default_value (tree var)
273{
274 ccp_prop_value_t val = { UNINITIALIZED, NULL_TREE, 0 };
275 gimple *stmt;
276
277 stmt = SSA_NAME_DEF_STMT (var);
278
279 if (gimple_nop_p (stmt))
280 {
281 /* Variables defined by an empty statement are those used
282 before being initialized. If VAR is a local variable, we
283 can assume initially that it is UNDEFINED, otherwise we must
284 consider it VARYING. */
285 if (!virtual_operand_p (var)
286 && SSA_NAME_VAR (var)
287 && TREE_CODE (SSA_NAME_VAR (var)) == VAR_DECL)
288 val.lattice_val = UNDEFINED;
289 else
290 {
291 val.lattice_val = VARYING;
292 val.mask = -1;
293 if (flag_tree_bit_ccp)
294 {
295 wide_int nonzero_bits = get_nonzero_bits (var);
296 if (nonzero_bits != -1)
297 {
298 val.lattice_val = CONSTANT;
299 val.value = build_zero_cst (TREE_TYPE (var));
300 val.mask = extend_mask (nonzero_bits, TYPE_SIGN (TREE_TYPE (var)));
301 }
302 }
303 }
304 }
305 else if (is_gimple_assign (stmt))
306 {
307 tree cst;
308 if (gimple_assign_single_p (stmt)
309 && DECL_P (gimple_assign_rhs1 (stmt))
310 && (cst = get_symbol_constant_value (gimple_assign_rhs1 (stmt))))
311 {
312 val.lattice_val = CONSTANT;
313 val.value = cst;
314 }
315 else
316 {
317 /* Any other variable defined by an assignment is considered
318 UNDEFINED. */
319 val.lattice_val = UNDEFINED;
320 }
321 }
322 else if ((is_gimple_call (stmt)
323 && gimple_call_lhs (stmt) != NULL_TREE)
324 || gimple_code (stmt) == GIMPLE_PHI)
325 {
326 /* A variable defined by a call or a PHI node is considered
327 UNDEFINED. */
328 val.lattice_val = UNDEFINED;
329 }
330 else
331 {
332 /* Otherwise, VAR will never take on a constant value. */
333 val.lattice_val = VARYING;
334 val.mask = -1;
335 }
336
337 return val;
338}
339
340
341/* Get the constant value associated with variable VAR. */
342
343static inline ccp_prop_value_t *
344get_value (tree var)
345{
346 ccp_prop_value_t *val;
347
348 if (const_val == NULL
349 || SSA_NAME_VERSION (var) >= n_const_val)
350 return NULL;
351
352 val = &const_val[SSA_NAME_VERSION (var)];
353 if (val->lattice_val == UNINITIALIZED)
354 *val = get_default_value (var);
355
356 canonicalize_value (val);
357
358 return val;
359}
360
361/* Return the constant tree value associated with VAR. */
362
363static inline tree
364get_constant_value (tree var)
365{
366 ccp_prop_value_t *val;
367 if (TREE_CODE (var) != SSA_NAME)
368 {
369 if (is_gimple_min_invariant (var))
370 return var;
371 return NULL_TREE;
372 }
373 val = get_value (var);
374 if (val
375 && val->lattice_val == CONSTANT
376 && (TREE_CODE (val->value) != INTEGER_CST
377 || val->mask == 0))
378 return val->value;
379 return NULL_TREE;
380}
381
382/* Sets the value associated with VAR to VARYING. */
383
384static inline void
385set_value_varying (tree var)
386{
387 ccp_prop_value_t *val = &const_val[SSA_NAME_VERSION (var)];
388
389 val->lattice_val = VARYING;
390 val->value = NULL_TREE;
391 val->mask = -1;
392}
393
394/* For integer constants, make sure to drop TREE_OVERFLOW. */
395
396static void
397canonicalize_value (ccp_prop_value_t *val)
398{
399 if (val->lattice_val != CONSTANT)
400 return;
401
402 if (TREE_OVERFLOW_P (val->value))
403 val->value = drop_tree_overflow (val->value);
404}
405
406/* Return whether the lattice transition is valid. */
407
408static bool
409valid_lattice_transition (ccp_prop_value_t old_val, ccp_prop_value_t new_val)
410{
411 /* Lattice transitions must always be monotonically increasing in
412 value. */
413 if (old_val.lattice_val < new_val.lattice_val)
414 return true;
415
416 if (old_val.lattice_val != new_val.lattice_val)
417 return false;
418
419 if (!old_val.value && !new_val.value)
420 return true;
421
422 /* Now both lattice values are CONSTANT. */
423
424 /* Allow arbitrary copy changes as we might look through PHI <a_1, ...>
425 when only a single copy edge is executable. */
426 if (TREE_CODE (old_val.value) == SSA_NAME
427 && TREE_CODE (new_val.value) == SSA_NAME)
428 return true;
429
430 /* Allow transitioning from a constant to a copy. */
431 if (is_gimple_min_invariant (old_val.value)
432 && TREE_CODE (new_val.value) == SSA_NAME)
433 return true;
434
435 /* Allow transitioning from PHI <&x, not executable> == &x
436 to PHI <&x, &y> == common alignment. */
437 if (TREE_CODE (old_val.value) != INTEGER_CST
438 && TREE_CODE (new_val.value) == INTEGER_CST)
439 return true;
440
441 /* Bit-lattices have to agree in the still valid bits. */
442 if (TREE_CODE (old_val.value) == INTEGER_CST
443 && TREE_CODE (new_val.value) == INTEGER_CST)
444 return (wi::bit_and_not (wi::to_widest (old_val.value), new_val.mask)
445 == wi::bit_and_not (wi::to_widest (new_val.value), new_val.mask));
446
447 /* Otherwise constant values have to agree. */
448 if (operand_equal_p (old_val.value, new_val.value, 0))
449 return true;
450
451 /* At least the kinds and types should agree now. */
452 if (TREE_CODE (old_val.value) != TREE_CODE (new_val.value)
453 || !types_compatible_p (TREE_TYPE (old_val.value),
454 TREE_TYPE (new_val.value)))
455 return false;
456
457 /* For floats and !HONOR_NANS allow transitions from (partial) NaN
458 to non-NaN. */
459 tree type = TREE_TYPE (new_val.value);
460 if (SCALAR_FLOAT_TYPE_P (type)
461 && !HONOR_NANS (type))
462 {
463 if (REAL_VALUE_ISNAN (TREE_REAL_CST (old_val.value)))
464 return true;
465 }
466 else if (VECTOR_FLOAT_TYPE_P (type)
467 && !HONOR_NANS (type))
468 {
469 unsigned int count
470 = tree_vector_builder::binary_encoded_nelts (old_val.value,
471 new_val.value);
472 for (unsigned int i = 0; i < count; ++i)
473 if (!REAL_VALUE_ISNAN
474 (TREE_REAL_CST (VECTOR_CST_ENCODED_ELT (old_val.value, i)))
475 && !operand_equal_p (VECTOR_CST_ENCODED_ELT (old_val.value, i),
476 VECTOR_CST_ENCODED_ELT (new_val.value, i), 0))
477 return false;
478 return true;
479 }
480 else if (COMPLEX_FLOAT_TYPE_P (type)
481 && !HONOR_NANS (type))
482 {
483 if (!REAL_VALUE_ISNAN (TREE_REAL_CST (TREE_REALPART (old_val.value)))
484 && !operand_equal_p (TREE_REALPART (old_val.value),
485 TREE_REALPART (new_val.value), 0))
486 return false;
487 if (!REAL_VALUE_ISNAN (TREE_REAL_CST (TREE_IMAGPART (old_val.value)))
488 && !operand_equal_p (TREE_IMAGPART (old_val.value),
489 TREE_IMAGPART (new_val.value), 0))
490 return false;
491 return true;
492 }
493 return false;
494}
495
496/* Set the value for variable VAR to NEW_VAL. Return true if the new
497 value is different from VAR's previous value. */
498
499static bool
500set_lattice_value (tree var, ccp_prop_value_t *new_val)
501{
502 /* We can deal with old UNINITIALIZED values just fine here. */
503 ccp_prop_value_t *old_val = &const_val[SSA_NAME_VERSION (var)];
504
505 canonicalize_value (new_val);
506
507 /* We have to be careful to not go up the bitwise lattice
508 represented by the mask. Instead of dropping to VARYING
509 use the meet operator to retain a conservative value.
510 Missed optimizations like PR65851 makes this necessary.
511 It also ensures we converge to a stable lattice solution. */
512 if (old_val->lattice_val != UNINITIALIZED)
513 ccp_lattice_meet (new_val, old_val);
514
515 gcc_checking_assert (valid_lattice_transition (*old_val, *new_val));
516
517 /* If *OLD_VAL and NEW_VAL are the same, return false to inform the
518 caller that this was a non-transition. */
519 if (old_val->lattice_val != new_val->lattice_val
520 || (new_val->lattice_val == CONSTANT
521 && (TREE_CODE (new_val->value) != TREE_CODE (old_val->value)
522 || (TREE_CODE (new_val->value) == INTEGER_CST
523 && (new_val->mask != old_val->mask
524 || (wi::bit_and_not (wi::to_widest (old_val->value),
525 new_val->mask)
526 != wi::bit_and_not (wi::to_widest (new_val->value),
527 new_val->mask))))
528 || (TREE_CODE (new_val->value) != INTEGER_CST
529 && !operand_equal_p (new_val->value, old_val->value, 0)))))
530 {
531 /* ??? We would like to delay creation of INTEGER_CSTs from
532 partially constants here. */
533
534 if (dump_file && (dump_flags & TDF_DETAILS))
535 {
536 dump_lattice_value (dump_file, "Lattice value changed to ", *new_val);
537 fprintf (dump_file, ". Adding SSA edges to worklist.\n");
538 }
539
540 *old_val = *new_val;
541
542 gcc_assert (new_val->lattice_val != UNINITIALIZED);
543 return true;
544 }
545
546 return false;
547}
548
549static ccp_prop_value_t get_value_for_expr (tree, bool);
550static ccp_prop_value_t bit_value_binop (enum tree_code, tree, tree, tree);
551void bit_value_binop (enum tree_code, signop, int, widest_int *, widest_int *,
552 signop, int, const widest_int &, const widest_int &,
553 signop, int, const widest_int &, const widest_int &);
554
555/* Return a widest_int that can be used for bitwise simplifications
556 from VAL. */
557
558static widest_int
559value_to_wide_int (ccp_prop_value_t val)
560{
561 if (val.value
562 && TREE_CODE (val.value) == INTEGER_CST)
563 return wi::to_widest (val.value);
564
565 return 0;
566}
567
568/* Return the value for the address expression EXPR based on alignment
569 information. */
570
571static ccp_prop_value_t
572get_value_from_alignment (tree expr)
573{
574 tree type = TREE_TYPE (expr);
575 ccp_prop_value_t val;
576 unsigned HOST_WIDE_INT bitpos;
577 unsigned int align;
578
579 gcc_assert (TREE_CODE (expr) == ADDR_EXPR);
580
581 get_pointer_alignment_1 (expr, &align, &bitpos);
582 val.mask = wi::bit_and_not
583 (POINTER_TYPE_P (type) || TYPE_UNSIGNED (type)
584 ? wi::mask <widest_int> (TYPE_PRECISION (type), false)
585 : -1,
586 align / BITS_PER_UNIT - 1);
587 val.lattice_val
588 = wi::sext (val.mask, TYPE_PRECISION (type)) == -1 ? VARYING : CONSTANT;
589 if (val.lattice_val == CONSTANT)
590 val.value = build_int_cstu (type, bitpos / BITS_PER_UNIT);
591 else
592 val.value = NULL_TREE;
593
594 return val;
595}
596
597/* Return the value for the tree operand EXPR. If FOR_BITS_P is true
598 return constant bits extracted from alignment information for
599 invariant addresses. */
600
601static ccp_prop_value_t
602get_value_for_expr (tree expr, bool for_bits_p)
603{
604 ccp_prop_value_t val;
605
606 if (TREE_CODE (expr) == SSA_NAME)
607 {
608 ccp_prop_value_t *val_ = get_value (expr);
609 if (val_)
610 val = *val_;
611 else
612 {
613 val.lattice_val = VARYING;
614 val.value = NULL_TREE;
615 val.mask = -1;
616 }
617 if (for_bits_p
618 && val.lattice_val == CONSTANT
619 && TREE_CODE (val.value) == ADDR_EXPR)
620 val = get_value_from_alignment (val.value);
621 /* Fall back to a copy value. */
622 if (!for_bits_p
623 && val.lattice_val == VARYING
624 && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (expr))
625 {
626 val.lattice_val = CONSTANT;
627 val.value = expr;
628 val.mask = -1;
629 }
630 }
631 else if (is_gimple_min_invariant (expr)
632 && (!for_bits_p || TREE_CODE (expr) == INTEGER_CST))
633 {
634 val.lattice_val = CONSTANT;
635 val.value = expr;
636 val.mask = 0;
637 canonicalize_value (&val);
638 }
639 else if (TREE_CODE (expr) == ADDR_EXPR)
640 val = get_value_from_alignment (expr);
641 else
642 {
643 val.lattice_val = VARYING;
644 val.mask = -1;
645 val.value = NULL_TREE;
646 }
647
648 if (val.lattice_val == VARYING
649 && TYPE_UNSIGNED (TREE_TYPE (expr)))
650 val.mask = wi::zext (val.mask, TYPE_PRECISION (TREE_TYPE (expr)));
651
652 return val;
653}
654
655/* Return the likely CCP lattice value for STMT.
656
657 If STMT has no operands, then return CONSTANT.
658
659 Else if undefinedness of operands of STMT cause its value to be
660 undefined, then return UNDEFINED.
661
662 Else if any operands of STMT are constants, then return CONSTANT.
663
664 Else return VARYING. */
665
666static ccp_lattice_t
667likely_value (gimple *stmt)
668{
669 bool has_constant_operand, has_undefined_operand, all_undefined_operands;
670 bool has_nsa_operand;
671 tree use;
672 ssa_op_iter iter;
673 unsigned i;
674
675 enum gimple_code code = gimple_code (stmt);
676
677 /* This function appears to be called only for assignments, calls,
678 conditionals, and switches, due to the logic in visit_stmt. */
679 gcc_assert (code == GIMPLE_ASSIGN
680 || code == GIMPLE_CALL
681 || code == GIMPLE_COND
682 || code == GIMPLE_SWITCH);
683
684 /* If the statement has volatile operands, it won't fold to a
685 constant value. */
686 if (gimple_has_volatile_ops (stmt))
687 return VARYING;
688
689 /* Arrive here for more complex cases. */
690 has_constant_operand = false;
691 has_undefined_operand = false;
692 all_undefined_operands = true;
693 has_nsa_operand = false;
694 FOR_EACH_SSA_TREE_OPERAND (use, stmt, iter, SSA_OP_USE)
695 {
696 ccp_prop_value_t *val = get_value (use);
697
698 if (val && val->lattice_val == UNDEFINED)
699 has_undefined_operand = true;
700 else
701 all_undefined_operands = false;
702
703 if (val && val->lattice_val == CONSTANT)
704 has_constant_operand = true;
705
706 if (SSA_NAME_IS_DEFAULT_DEF (use)
707 || !prop_simulate_again_p (SSA_NAME_DEF_STMT (use)))
708 has_nsa_operand = true;
709 }
710
711 /* There may be constants in regular rhs operands. For calls we
712 have to ignore lhs, fndecl and static chain, otherwise only
713 the lhs. */
714 for (i = (is_gimple_call (stmt) ? 2 : 0) + gimple_has_lhs (stmt);
715 i < gimple_num_ops (stmt); ++i)
716 {
717 tree op = gimple_op (stmt, i);
718 if (!op || TREE_CODE (op) == SSA_NAME)
719 continue;
720 if (is_gimple_min_invariant (op))
721 has_constant_operand = true;
722 }
723
724 if (has_constant_operand)
725 all_undefined_operands = false;
726
727 if (has_undefined_operand
728 && code == GIMPLE_CALL
729 && gimple_call_internal_p (stmt))
730 switch (gimple_call_internal_fn (stmt))
731 {
732 /* These 3 builtins use the first argument just as a magic
733 way how to find out a decl uid. */
734 case IFN_GOMP_SIMD_LANE:
735 case IFN_GOMP_SIMD_VF:
736 case IFN_GOMP_SIMD_LAST_LANE:
737 has_undefined_operand = false;
738 break;
739 default:
740 break;
741 }
742
743 /* If the operation combines operands like COMPLEX_EXPR make sure to
744 not mark the result UNDEFINED if only one part of the result is
745 undefined. */
746 if (has_undefined_operand && all_undefined_operands)
747 return UNDEFINED;
748 else if (code == GIMPLE_ASSIGN && has_undefined_operand)
749 {
750 switch (gimple_assign_rhs_code (stmt))
751 {
752 /* Unary operators are handled with all_undefined_operands. */
753 case PLUS_EXPR:
754 case MINUS_EXPR:
755 case POINTER_PLUS_EXPR:
756 case BIT_XOR_EXPR:
757 /* Not MIN_EXPR, MAX_EXPR. One VARYING operand may be selected.
758 Not bitwise operators, one VARYING operand may specify the
759 result completely.
760 Not logical operators for the same reason, apart from XOR.
761 Not COMPLEX_EXPR as one VARYING operand makes the result partly
762 not UNDEFINED. Not *DIV_EXPR, comparisons and shifts because
763 the undefined operand may be promoted. */
764 return UNDEFINED;
765
766 case ADDR_EXPR:
767 /* If any part of an address is UNDEFINED, like the index
768 of an ARRAY_EXPR, then treat the result as UNDEFINED. */
769 return UNDEFINED;
770
771 default:
772 ;
773 }
774 }
775 /* If there was an UNDEFINED operand but the result may be not UNDEFINED
776 fall back to CONSTANT. During iteration UNDEFINED may still drop
777 to CONSTANT. */
778 if (has_undefined_operand)
779 return CONSTANT;
780
781 /* We do not consider virtual operands here -- load from read-only
782 memory may have only VARYING virtual operands, but still be
783 constant. Also we can combine the stmt with definitions from
784 operands whose definitions are not simulated again. */
785 if (has_constant_operand
786 || has_nsa_operand
787 || gimple_references_memory_p (stmt))
788 return CONSTANT;
789
790 return VARYING;
791}
792
793/* Returns true if STMT cannot be constant. */
794
795static bool
796surely_varying_stmt_p (gimple *stmt)
797{
798 /* If the statement has operands that we cannot handle, it cannot be
799 constant. */
800 if (gimple_has_volatile_ops (stmt))
801 return true;
802
803 /* If it is a call and does not return a value or is not a
804 builtin and not an indirect call or a call to function with
805 assume_aligned/alloc_align attribute, it is varying. */
806 if (is_gimple_call (stmt))
807 {
808 tree fndecl, fntype = gimple_call_fntype (stmt);
809 if (!gimple_call_lhs (stmt)
810 || ((fndecl = gimple_call_fndecl (stmt)) != NULL_TREE
811 && !DECL_BUILT_IN (fndecl)
812 && !lookup_attribute ("assume_aligned",
813 TYPE_ATTRIBUTES (fntype))
814 && !lookup_attribute ("alloc_align",
815 TYPE_ATTRIBUTES (fntype))))
816 return true;
817 }
818
819 /* Any other store operation is not interesting. */
820 else if (gimple_vdef (stmt))
821 return true;
822
823 /* Anything other than assignments and conditional jumps are not
824 interesting for CCP. */
825 if (gimple_code (stmt) != GIMPLE_ASSIGN
826 && gimple_code (stmt) != GIMPLE_COND
827 && gimple_code (stmt) != GIMPLE_SWITCH
828 && gimple_code (stmt) != GIMPLE_CALL)
829 return true;
830
831 return false;
832}
833
834/* Initialize local data structures for CCP. */
835
836static void
837ccp_initialize (void)
838{
839 basic_block bb;
840
841 n_const_val = num_ssa_names;
842 const_val = XCNEWVEC (ccp_prop_value_t, n_const_val);
843
844 /* Initialize simulation flags for PHI nodes and statements. */
845 FOR_EACH_BB_FN (bb, cfun)
846 {
847 gimple_stmt_iterator i;
848
849 for (i = gsi_start_bb (bb); !gsi_end_p (i); gsi_next (&i))
850 {
851 gimple *stmt = gsi_stmt (i);
852 bool is_varying;
853
854 /* If the statement is a control insn, then we do not
855 want to avoid simulating the statement once. Failure
856 to do so means that those edges will never get added. */
857 if (stmt_ends_bb_p (stmt))
858 is_varying = false;
859 else
860 is_varying = surely_varying_stmt_p (stmt);
861
862 if (is_varying)
863 {
864 tree def;
865 ssa_op_iter iter;
866
867 /* If the statement will not produce a constant, mark
868 all its outputs VARYING. */
869 FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_ALL_DEFS)
870 set_value_varying (def);
871 }
872 prop_set_simulate_again (stmt, !is_varying);
873 }
874 }
875
876 /* Now process PHI nodes. We never clear the simulate_again flag on
877 phi nodes, since we do not know which edges are executable yet,
878 except for phi nodes for virtual operands when we do not do store ccp. */
879 FOR_EACH_BB_FN (bb, cfun)
880 {
881 gphi_iterator i;
882
883 for (i = gsi_start_phis (bb); !gsi_end_p (i); gsi_next (&i))
884 {
885 gphi *phi = i.phi ();
886
887 if (virtual_operand_p (gimple_phi_result (phi)))
888 prop_set_simulate_again (phi, false);
889 else
890 prop_set_simulate_again (phi, true);
891 }
892 }
893}
894
895/* Debug count support. Reset the values of ssa names
896 VARYING when the total number ssa names analyzed is
897 beyond the debug count specified. */
898
899static void
900do_dbg_cnt (void)
901{
902 unsigned i;
903 for (i = 0; i < num_ssa_names; i++)
904 {
905 if (!dbg_cnt (ccp))
906 {
907 const_val[i].lattice_val = VARYING;
908 const_val[i].mask = -1;
909 const_val[i].value = NULL_TREE;
910 }
911 }
912}
913
914
915/* We want to provide our own GET_VALUE and FOLD_STMT virtual methods. */
916class ccp_folder : public substitute_and_fold_engine
917{
918 public:
919 tree get_value (tree) FINAL OVERRIDE;
920 bool fold_stmt (gimple_stmt_iterator *) FINAL OVERRIDE;
921};
922
923/* This method just wraps GET_CONSTANT_VALUE for now. Over time
924 naked calls to GET_CONSTANT_VALUE should be eliminated in favor
925 of calling member functions. */
926
927tree
928ccp_folder::get_value (tree op)
929{
930 return get_constant_value (op);
931}
932
933/* Do final substitution of propagated values, cleanup the flowgraph and
934 free allocated storage. If NONZERO_P, record nonzero bits.
935
936 Return TRUE when something was optimized. */
937
938static bool
939ccp_finalize (bool nonzero_p)
940{
941 bool something_changed;
942 unsigned i;
943 tree name;
944
945 do_dbg_cnt ();
946
947 /* Derive alignment and misalignment information from partially
948 constant pointers in the lattice or nonzero bits from partially
949 constant integers. */
950 FOR_EACH_SSA_NAME (i, name, cfun)
951 {
952 ccp_prop_value_t *val;
953 unsigned int tem, align;
954
955 if (!POINTER_TYPE_P (TREE_TYPE (name))
956 && (!INTEGRAL_TYPE_P (TREE_TYPE (name))
957 /* Don't record nonzero bits before IPA to avoid
958 using too much memory. */
959 || !nonzero_p))
960 continue;
961
962 val = get_value (name);
963 if (val->lattice_val != CONSTANT
964 || TREE_CODE (val->value) != INTEGER_CST
965 || val->mask == 0)
966 continue;
967
968 if (POINTER_TYPE_P (TREE_TYPE (name)))
969 {
970 /* Trailing mask bits specify the alignment, trailing value
971 bits the misalignment. */
972 tem = val->mask.to_uhwi ();
973 align = least_bit_hwi (tem);
974 if (align > 1)
975 set_ptr_info_alignment (get_ptr_info (name), align,
976 (TREE_INT_CST_LOW (val->value)
977 & (align - 1)));
978 }
979 else
980 {
981 unsigned int precision = TYPE_PRECISION (TREE_TYPE (val->value));
982 wide_int nonzero_bits
983 = (wide_int::from (val->mask, precision, UNSIGNED)
984 | wi::to_wide (val->value));
985 nonzero_bits &= get_nonzero_bits (name);
986 set_nonzero_bits (name, nonzero_bits);
987 }
988 }
989
990 /* Perform substitutions based on the known constant values. */
991 class ccp_folder ccp_folder;
992 something_changed = ccp_folder.substitute_and_fold ();
993
994 free (const_val);
995 const_val = NULL;
996 return something_changed;
997}
998
999
1000/* Compute the meet operator between *VAL1 and *VAL2. Store the result
1001 in VAL1.
1002
1003 any M UNDEFINED = any
1004 any M VARYING = VARYING
1005 Ci M Cj = Ci if (i == j)
1006 Ci M Cj = VARYING if (i != j)
1007 */
1008
1009static void
1010ccp_lattice_meet (ccp_prop_value_t *val1, ccp_prop_value_t *val2)
1011{
1012 if (val1->lattice_val == UNDEFINED
1013 /* For UNDEFINED M SSA we can't always SSA because its definition
1014 may not dominate the PHI node. Doing optimistic copy propagation
1015 also causes a lot of gcc.dg/uninit-pred*.c FAILs. */
1016 && (val2->lattice_val != CONSTANT
1017 || TREE_CODE (val2->value) != SSA_NAME))
1018 {
1019 /* UNDEFINED M any = any */
1020 *val1 = *val2;
1021 }
1022 else if (val2->lattice_val == UNDEFINED
1023 /* See above. */
1024 && (val1->lattice_val != CONSTANT
1025 || TREE_CODE (val1->value) != SSA_NAME))
1026 {
1027 /* any M UNDEFINED = any
1028 Nothing to do. VAL1 already contains the value we want. */
1029 ;
1030 }
1031 else if (val1->lattice_val == VARYING
1032 || val2->lattice_val == VARYING)
1033 {
1034 /* any M VARYING = VARYING. */
1035 val1->lattice_val = VARYING;
1036 val1->mask = -1;
1037 val1->value = NULL_TREE;
1038 }
1039 else if (val1->lattice_val == CONSTANT
1040 && val2->lattice_val == CONSTANT
1041 && TREE_CODE (val1->value) == INTEGER_CST
1042 && TREE_CODE (val2->value) == INTEGER_CST)
1043 {
1044 /* Ci M Cj = Ci if (i == j)
1045 Ci M Cj = VARYING if (i != j)
1046
1047 For INTEGER_CSTs mask unequal bits. If no equal bits remain,
1048 drop to varying. */
1049 val1->mask = (val1->mask | val2->mask
1050 | (wi::to_widest (val1->value)
1051 ^ wi::to_widest (val2->value)));
1052 if (wi::sext (val1->mask, TYPE_PRECISION (TREE_TYPE (val1->value))) == -1)
1053 {
1054 val1->lattice_val = VARYING;
1055 val1->value = NULL_TREE;
1056 }
1057 }
1058 else if (val1->lattice_val == CONSTANT
1059 && val2->lattice_val == CONSTANT
1060 && operand_equal_p (val1->value, val2->value, 0))
1061 {
1062 /* Ci M Cj = Ci if (i == j)
1063 Ci M Cj = VARYING if (i != j)
1064
1065 VAL1 already contains the value we want for equivalent values. */
1066 }
1067 else if (val1->lattice_val == CONSTANT
1068 && val2->lattice_val == CONSTANT
1069 && (TREE_CODE (val1->value) == ADDR_EXPR
1070 || TREE_CODE (val2->value) == ADDR_EXPR))
1071 {
1072 /* When not equal addresses are involved try meeting for
1073 alignment. */
1074 ccp_prop_value_t tem = *val2;
1075 if (TREE_CODE (val1->value) == ADDR_EXPR)
1076 *val1 = get_value_for_expr (val1->value, true);
1077 if (TREE_CODE (val2->value) == ADDR_EXPR)
1078 tem = get_value_for_expr (val2->value, true);
1079 ccp_lattice_meet (val1, &tem);
1080 }
1081 else
1082 {
1083 /* Any other combination is VARYING. */
1084 val1->lattice_val = VARYING;
1085 val1->mask = -1;
1086 val1->value = NULL_TREE;
1087 }
1088}
1089
1090
1091/* Loop through the PHI_NODE's parameters for BLOCK and compare their
1092 lattice values to determine PHI_NODE's lattice value. The value of a
1093 PHI node is determined calling ccp_lattice_meet with all the arguments
1094 of the PHI node that are incoming via executable edges. */
1095
1096enum ssa_prop_result
1097ccp_propagate::visit_phi (gphi *phi)
1098{
1099 unsigned i;
1100 ccp_prop_value_t new_val;
1101
1102 if (dump_file && (dump_flags & TDF_DETAILS))
1103 {
1104 fprintf (dump_file, "\nVisiting PHI node: ");
1105 print_gimple_stmt (dump_file, phi, 0, dump_flags);
1106 }
1107
1108 new_val.lattice_val = UNDEFINED;
1109 new_val.value = NULL_TREE;
1110 new_val.mask = 0;
1111
1112 bool first = true;
1113 bool non_exec_edge = false;
1114 for (i = 0; i < gimple_phi_num_args (phi); i++)
1115 {
1116 /* Compute the meet operator over all the PHI arguments flowing
1117 through executable edges. */
1118 edge e = gimple_phi_arg_edge (phi, i);
1119
1120 if (dump_file && (dump_flags & TDF_DETAILS))
1121 {
1122 fprintf (dump_file,
1123 "\n Argument #%d (%d -> %d %sexecutable)\n",
1124 i, e->src->index, e->dest->index,
1125 (e->flags & EDGE_EXECUTABLE) ? "" : "not ");
1126 }
1127
1128 /* If the incoming edge is executable, Compute the meet operator for
1129 the existing value of the PHI node and the current PHI argument. */
1130 if (e->flags & EDGE_EXECUTABLE)
1131 {
1132 tree arg = gimple_phi_arg (phi, i)->def;
1133 ccp_prop_value_t arg_val = get_value_for_expr (arg, false);
1134
1135 if (first)
1136 {
1137 new_val = arg_val;
1138 first = false;
1139 }
1140 else
1141 ccp_lattice_meet (&new_val, &arg_val);
1142
1143 if (dump_file && (dump_flags & TDF_DETAILS))
1144 {
1145 fprintf (dump_file, "\t");
1146 print_generic_expr (dump_file, arg, dump_flags);
1147 dump_lattice_value (dump_file, "\tValue: ", arg_val);
1148 fprintf (dump_file, "\n");
1149 }
1150
1151 if (new_val.lattice_val == VARYING)
1152 break;
1153 }
1154 else
1155 non_exec_edge = true;
1156 }
1157
1158 /* In case there were non-executable edges and the value is a copy
1159 make sure its definition dominates the PHI node. */
1160 if (non_exec_edge
1161 && new_val.lattice_val == CONSTANT
1162 && TREE_CODE (new_val.value) == SSA_NAME
1163 && ! SSA_NAME_IS_DEFAULT_DEF (new_val.value)
1164 && ! dominated_by_p (CDI_DOMINATORS, gimple_bb (phi),
1165 gimple_bb (SSA_NAME_DEF_STMT (new_val.value))))
1166 {
1167 new_val.lattice_val = VARYING;
1168 new_val.value = NULL_TREE;
1169 new_val.mask = -1;
1170 }
1171
1172 if (dump_file && (dump_flags & TDF_DETAILS))
1173 {
1174 dump_lattice_value (dump_file, "\n PHI node value: ", new_val);
1175 fprintf (dump_file, "\n\n");
1176 }
1177
1178 /* Make the transition to the new value. */
1179 if (set_lattice_value (gimple_phi_result (phi), &new_val))
1180 {
1181 if (new_val.lattice_val == VARYING)
1182 return SSA_PROP_VARYING;
1183 else
1184 return SSA_PROP_INTERESTING;
1185 }
1186 else
1187 return SSA_PROP_NOT_INTERESTING;
1188}
1189
1190/* Return the constant value for OP or OP otherwise. */
1191
1192static tree
1193valueize_op (tree op)
1194{
1195 if (TREE_CODE (op) == SSA_NAME)
1196 {
1197 tree tem = get_constant_value (op);
1198 if (tem)
1199 return tem;
1200 }
1201 return op;
1202}
1203
1204/* Return the constant value for OP, but signal to not follow SSA
1205 edges if the definition may be simulated again. */
1206
1207static tree
1208valueize_op_1 (tree op)
1209{
1210 if (TREE_CODE (op) == SSA_NAME)
1211 {
1212 /* If the definition may be simulated again we cannot follow
1213 this SSA edge as the SSA propagator does not necessarily
1214 re-visit the use. */
1215 gimple *def_stmt = SSA_NAME_DEF_STMT (op);
1216 if (!gimple_nop_p (def_stmt)
1217 && prop_simulate_again_p (def_stmt))
1218 return NULL_TREE;
1219 tree tem = get_constant_value (op);
1220 if (tem)
1221 return tem;
1222 }
1223 return op;
1224}
1225
1226/* CCP specific front-end to the non-destructive constant folding
1227 routines.
1228
1229 Attempt to simplify the RHS of STMT knowing that one or more
1230 operands are constants.
1231
1232 If simplification is possible, return the simplified RHS,
1233 otherwise return the original RHS or NULL_TREE. */
1234
1235static tree
1236ccp_fold (gimple *stmt)
1237{
1238 location_t loc = gimple_location (stmt);
1239 switch (gimple_code (stmt))
1240 {
1241 case GIMPLE_COND:
1242 {
1243 /* Handle comparison operators that can appear in GIMPLE form. */
1244 tree op0 = valueize_op (gimple_cond_lhs (stmt));
1245 tree op1 = valueize_op (gimple_cond_rhs (stmt));
1246 enum tree_code code = gimple_cond_code (stmt);
1247 return fold_binary_loc (loc, code, boolean_type_node, op0, op1);
1248 }
1249
1250 case GIMPLE_SWITCH:
1251 {
1252 /* Return the constant switch index. */
1253 return valueize_op (gimple_switch_index (as_a <gswitch *> (stmt)));
1254 }
1255
1256 case GIMPLE_ASSIGN:
1257 case GIMPLE_CALL:
1258 return gimple_fold_stmt_to_constant_1 (stmt,
1259 valueize_op, valueize_op_1);
1260
1261 default:
1262 gcc_unreachable ();
1263 }
1264}
1265
1266/* Apply the operation CODE in type TYPE to the value, mask pair
1267 RVAL and RMASK representing a value of type RTYPE and set
1268 the value, mask pair *VAL and *MASK to the result. */
1269
1270void
1271bit_value_unop (enum tree_code code, signop type_sgn, int type_precision,
1272 widest_int *val, widest_int *mask,
1273 signop rtype_sgn, int rtype_precision,
1274 const widest_int &rval, const widest_int &rmask)
1275{
1276 switch (code)
1277 {
1278 case BIT_NOT_EXPR:
1279 *mask = rmask;
1280 *val = ~rval;
1281 break;
1282
1283 case NEGATE_EXPR:
1284 {
1285 widest_int temv, temm;
1286 /* Return ~rval + 1. */
1287 bit_value_unop (BIT_NOT_EXPR, type_sgn, type_precision, &temv, &temm,
1288 type_sgn, type_precision, rval, rmask);
1289 bit_value_binop (PLUS_EXPR, type_sgn, type_precision, val, mask,
1290 type_sgn, type_precision, temv, temm,
1291 type_sgn, type_precision, 1, 0);
1292 break;
1293 }
1294
1295 CASE_CONVERT:
1296 {
1297 /* First extend mask and value according to the original type. */
1298 *mask = wi::ext (rmask, rtype_precision, rtype_sgn);
1299 *val = wi::ext (rval, rtype_precision, rtype_sgn);
1300
1301 /* Then extend mask and value according to the target type. */
1302 *mask = wi::ext (*mask, type_precision, type_sgn);
1303 *val = wi::ext (*val, type_precision, type_sgn);
1304 break;
1305 }
1306
1307 default:
1308 *mask = -1;
1309 break;
1310 }
1311}
1312
1313/* Apply the operation CODE in type TYPE to the value, mask pairs
1314 R1VAL, R1MASK and R2VAL, R2MASK representing a values of type R1TYPE
1315 and R2TYPE and set the value, mask pair *VAL and *MASK to the result. */
1316
1317void
1318bit_value_binop (enum tree_code code, signop sgn, int width,
1319 widest_int *val, widest_int *mask,
1320 signop r1type_sgn, int r1type_precision,
1321 const widest_int &r1val, const widest_int &r1mask,
1322 signop r2type_sgn, int r2type_precision,
1323 const widest_int &r2val, const widest_int &r2mask)
1324{
1325 bool swap_p = false;
1326
1327 /* Assume we'll get a constant result. Use an initial non varying
1328 value, we fall back to varying in the end if necessary. */
1329 *mask = -1;
1330
1331 switch (code)
1332 {
1333 case BIT_AND_EXPR:
1334 /* The mask is constant where there is a known not
1335 set bit, (m1 | m2) & ((v1 | m1) & (v2 | m2)) */
1336 *mask = (r1mask | r2mask) & (r1val | r1mask) & (r2val | r2mask);
1337 *val = r1val & r2val;
1338 break;
1339
1340 case BIT_IOR_EXPR:
1341 /* The mask is constant where there is a known
1342 set bit, (m1 | m2) & ~((v1 & ~m1) | (v2 & ~m2)). */
1343 *mask = wi::bit_and_not (r1mask | r2mask,
1344 wi::bit_and_not (r1val, r1mask)
1345 | wi::bit_and_not (r2val, r2mask));
1346 *val = r1val | r2val;
1347 break;
1348
1349 case BIT_XOR_EXPR:
1350 /* m1 | m2 */
1351 *mask = r1mask | r2mask;
1352 *val = r1val ^ r2val;
1353 break;
1354
1355 case LROTATE_EXPR:
1356 case RROTATE_EXPR:
1357 if (r2mask == 0)
1358 {
1359 widest_int shift = r2val;
1360 if (shift == 0)
1361 {
1362 *mask = r1mask;
1363 *val = r1val;
1364 }
1365 else
1366 {
1367 if (wi::neg_p (shift))
1368 {
1369 shift = -shift;
1370 if (code == RROTATE_EXPR)
1371 code = LROTATE_EXPR;
1372 else
1373 code = RROTATE_EXPR;
1374 }
1375 if (code == RROTATE_EXPR)
1376 {
1377 *mask = wi::rrotate (r1mask, shift, width);
1378 *val = wi::rrotate (r1val, shift, width);
1379 }
1380 else
1381 {
1382 *mask = wi::lrotate (r1mask, shift, width);
1383 *val = wi::lrotate (r1val, shift, width);
1384 }
1385 }
1386 }
1387 break;
1388
1389 case LSHIFT_EXPR:
1390 case RSHIFT_EXPR:
1391 /* ??? We can handle partially known shift counts if we know
1392 its sign. That way we can tell that (x << (y | 8)) & 255
1393 is zero. */
1394 if (r2mask == 0)
1395 {
1396 widest_int shift = r2val;
1397 if (shift == 0)
1398 {
1399 *mask = r1mask;
1400 *val = r1val;
1401 }
1402 else
1403 {
1404 if (wi::neg_p (shift))
1405 {
1406 shift = -shift;
1407 if (code == RSHIFT_EXPR)
1408 code = LSHIFT_EXPR;
1409 else
1410 code = RSHIFT_EXPR;
1411 }
1412 if (code == RSHIFT_EXPR)
1413 {
1414 *mask = wi::rshift (wi::ext (r1mask, width, sgn), shift, sgn);
1415 *val = wi::rshift (wi::ext (r1val, width, sgn), shift, sgn);
1416 }
1417 else
1418 {
1419 *mask = wi::ext (r1mask << shift, width, sgn);
1420 *val = wi::ext (r1val << shift, width, sgn);
1421 }
1422 }
1423 }
1424 break;
1425
1426 case PLUS_EXPR:
1427 case POINTER_PLUS_EXPR:
1428 {
1429 /* Do the addition with unknown bits set to zero, to give carry-ins of
1430 zero wherever possible. */
1431 widest_int lo = (wi::bit_and_not (r1val, r1mask)
1432 + wi::bit_and_not (r2val, r2mask));
1433 lo = wi::ext (lo, width, sgn);
1434 /* Do the addition with unknown bits set to one, to give carry-ins of
1435 one wherever possible. */
1436 widest_int hi = (r1val | r1mask) + (r2val | r2mask);
1437 hi = wi::ext (hi, width, sgn);
1438 /* Each bit in the result is known if (a) the corresponding bits in
1439 both inputs are known, and (b) the carry-in to that bit position
1440 is known. We can check condition (b) by seeing if we got the same
1441 result with minimised carries as with maximised carries. */
1442 *mask = r1mask | r2mask | (lo ^ hi);
1443 *mask = wi::ext (*mask, width, sgn);
1444 /* It shouldn't matter whether we choose lo or hi here. */
1445 *val = lo;
1446 break;
1447 }
1448
1449 case MINUS_EXPR:
1450 {
1451 widest_int temv, temm;
1452 bit_value_unop (NEGATE_EXPR, r2type_sgn, r2type_precision, &temv, &temm,
1453 r2type_sgn, r2type_precision, r2val, r2mask);
1454 bit_value_binop (PLUS_EXPR, sgn, width, val, mask,
1455 r1type_sgn, r1type_precision, r1val, r1mask,
1456 r2type_sgn, r2type_precision, temv, temm);
1457 break;
1458 }
1459
1460 case MULT_EXPR:
1461 {
1462 /* Just track trailing zeros in both operands and transfer
1463 them to the other. */
1464 int r1tz = wi::ctz (r1val | r1mask);
1465 int r2tz = wi::ctz (r2val | r2mask);
1466 if (r1tz + r2tz >= width)
1467 {
1468 *mask = 0;
1469 *val = 0;
1470 }
1471 else if (r1tz + r2tz > 0)
1472 {
1473 *mask = wi::ext (wi::mask <widest_int> (r1tz + r2tz, true),
1474 width, sgn);
1475 *val = 0;
1476 }
1477 break;
1478 }
1479
1480 case EQ_EXPR:
1481 case NE_EXPR:
1482 {
1483 widest_int m = r1mask | r2mask;
1484 if (wi::bit_and_not (r1val, m) != wi::bit_and_not (r2val, m))
1485 {
1486 *mask = 0;
1487 *val = ((code == EQ_EXPR) ? 0 : 1);
1488 }
1489 else
1490 {
1491 /* We know the result of a comparison is always one or zero. */
1492 *mask = 1;
1493 *val = 0;
1494 }
1495 break;
1496 }
1497
1498 case GE_EXPR:
1499 case GT_EXPR:
1500 swap_p = true;
1501 code = swap_tree_comparison (code);
1502 /* Fall through. */
1503 case LT_EXPR:
1504 case LE_EXPR:
1505 {
1506 int minmax, maxmin;
1507
1508 const widest_int &o1val = swap_p ? r2val : r1val;
1509 const widest_int &o1mask = swap_p ? r2mask : r1mask;
1510 const widest_int &o2val = swap_p ? r1val : r2val;
1511 const widest_int &o2mask = swap_p ? r1mask : r2mask;
1512
1513 /* If the most significant bits are not known we know nothing. */
1514 if (wi::neg_p (o1mask) || wi::neg_p (o2mask))
1515 break;
1516
1517 /* For comparisons the signedness is in the comparison operands. */
1518 sgn = r1type_sgn;
1519
1520 /* If we know the most significant bits we know the values
1521 value ranges by means of treating varying bits as zero
1522 or one. Do a cross comparison of the max/min pairs. */
1523 maxmin = wi::cmp (o1val | o1mask,
1524 wi::bit_and_not (o2val, o2mask), sgn);
1525 minmax = wi::cmp (wi::bit_and_not (o1val, o1mask),
1526 o2val | o2mask, sgn);
1527 if (maxmin < 0) /* o1 is less than o2. */
1528 {
1529 *mask = 0;
1530 *val = 1;
1531 }
1532 else if (minmax > 0) /* o1 is not less or equal to o2. */
1533 {
1534 *mask = 0;
1535 *val = 0;
1536 }
1537 else if (maxmin == minmax) /* o1 and o2 are equal. */
1538 {
1539 /* This probably should never happen as we'd have
1540 folded the thing during fully constant value folding. */
1541 *mask = 0;
1542 *val = (code == LE_EXPR ? 1 : 0);
1543 }
1544 else
1545 {
1546 /* We know the result of a comparison is always one or zero. */
1547 *mask = 1;
1548 *val = 0;
1549 }
1550 break;
1551 }
1552
1553 default:;
1554 }
1555}
1556
1557/* Return the propagation value when applying the operation CODE to
1558 the value RHS yielding type TYPE. */
1559
1560static ccp_prop_value_t
1561bit_value_unop (enum tree_code code, tree type, tree rhs)
1562{
1563 ccp_prop_value_t rval = get_value_for_expr (rhs, true);
1564 widest_int value, mask;
1565 ccp_prop_value_t val;
1566
1567 if (rval.lattice_val == UNDEFINED)
1568 return rval;
1569
1570 gcc_assert ((rval.lattice_val == CONSTANT
1571 && TREE_CODE (rval.value) == INTEGER_CST)
1572 || wi::sext (rval.mask, TYPE_PRECISION (TREE_TYPE (rhs))) == -1);
1573 bit_value_unop (code, TYPE_SIGN (type), TYPE_PRECISION (type), &value, &mask,
1574 TYPE_SIGN (TREE_TYPE (rhs)), TYPE_PRECISION (TREE_TYPE (rhs)),
1575 value_to_wide_int (rval), rval.mask);
1576 if (wi::sext (mask, TYPE_PRECISION (type)) != -1)
1577 {
1578 val.lattice_val = CONSTANT;
1579 val.mask = mask;
1580 /* ??? Delay building trees here. */
1581 val.value = wide_int_to_tree (type, value);
1582 }
1583 else
1584 {
1585 val.lattice_val = VARYING;
1586 val.value = NULL_TREE;
1587 val.mask = -1;
1588 }
1589 return val;
1590}
1591
1592/* Return the propagation value when applying the operation CODE to
1593 the values RHS1 and RHS2 yielding type TYPE. */
1594
1595static ccp_prop_value_t
1596bit_value_binop (enum tree_code code, tree type, tree rhs1, tree rhs2)
1597{
1598 ccp_prop_value_t r1val = get_value_for_expr (rhs1, true);
1599 ccp_prop_value_t r2val = get_value_for_expr (rhs2, true);
1600 widest_int value, mask;
1601 ccp_prop_value_t val;
1602
1603 if (r1val.lattice_val == UNDEFINED
1604 || r2val.lattice_val == UNDEFINED)
1605 {
1606 val.lattice_val = VARYING;
1607 val.value = NULL_TREE;
1608 val.mask = -1;
1609 return val;
1610 }
1611
1612 gcc_assert ((r1val.lattice_val == CONSTANT
1613 && TREE_CODE (r1val.value) == INTEGER_CST)
1614 || wi::sext (r1val.mask,
1615 TYPE_PRECISION (TREE_TYPE (rhs1))) == -1);
1616 gcc_assert ((r2val.lattice_val == CONSTANT
1617 && TREE_CODE (r2val.value) == INTEGER_CST)
1618 || wi::sext (r2val.mask,
1619 TYPE_PRECISION (TREE_TYPE (rhs2))) == -1);
1620 bit_value_binop (code, TYPE_SIGN (type), TYPE_PRECISION (type), &value, &mask,
1621 TYPE_SIGN (TREE_TYPE (rhs1)), TYPE_PRECISION (TREE_TYPE (rhs1)),
1622 value_to_wide_int (r1val), r1val.mask,
1623 TYPE_SIGN (TREE_TYPE (rhs2)), TYPE_PRECISION (TREE_TYPE (rhs2)),
1624 value_to_wide_int (r2val), r2val.mask);
1625
1626 if (wi::sext (mask, TYPE_PRECISION (type)) != -1)
1627 {
1628 val.lattice_val = CONSTANT;
1629 val.mask = mask;
1630 /* ??? Delay building trees here. */
1631 val.value = wide_int_to_tree (type, value);
1632 }
1633 else
1634 {
1635 val.lattice_val = VARYING;
1636 val.value = NULL_TREE;
1637 val.mask = -1;
1638 }
1639 return val;
1640}
1641
1642/* Return the propagation value for __builtin_assume_aligned
1643 and functions with assume_aligned or alloc_aligned attribute.
1644 For __builtin_assume_aligned, ATTR is NULL_TREE,
1645 for assume_aligned attribute ATTR is non-NULL and ALLOC_ALIGNED
1646 is false, for alloc_aligned attribute ATTR is non-NULL and
1647 ALLOC_ALIGNED is true. */
1648
1649static ccp_prop_value_t
1650bit_value_assume_aligned (gimple *stmt, tree attr, ccp_prop_value_t ptrval,
1651 bool alloc_aligned)
1652{
1653 tree align, misalign = NULL_TREE, type;
1654 unsigned HOST_WIDE_INT aligni, misaligni = 0;
1655 ccp_prop_value_t alignval;
1656 widest_int value, mask;
1657 ccp_prop_value_t val;
1658
1659 if (attr == NULL_TREE)
1660 {
1661 tree ptr = gimple_call_arg (stmt, 0);
1662 type = TREE_TYPE (ptr);
1663 ptrval = get_value_for_expr (ptr, true);
1664 }
1665 else
1666 {
1667 tree lhs = gimple_call_lhs (stmt);
1668 type = TREE_TYPE (lhs);
1669 }
1670
1671 if (ptrval.lattice_val == UNDEFINED)
1672 return ptrval;
1673 gcc_assert ((ptrval.lattice_val == CONSTANT
1674 && TREE_CODE (ptrval.value) == INTEGER_CST)
1675 || wi::sext (ptrval.mask, TYPE_PRECISION (type)) == -1);
1676 if (attr == NULL_TREE)
1677 {
1678 /* Get aligni and misaligni from __builtin_assume_aligned. */
1679 align = gimple_call_arg (stmt, 1);
1680 if (!tree_fits_uhwi_p (align))
1681 return ptrval;
1682 aligni = tree_to_uhwi (align);
1683 if (gimple_call_num_args (stmt) > 2)
1684 {
1685 misalign = gimple_call_arg (stmt, 2);
1686 if (!tree_fits_uhwi_p (misalign))
1687 return ptrval;
1688 misaligni = tree_to_uhwi (misalign);
1689 }
1690 }
1691 else
1692 {
1693 /* Get aligni and misaligni from assume_aligned or
1694 alloc_align attributes. */
1695 if (TREE_VALUE (attr) == NULL_TREE)
1696 return ptrval;
1697 attr = TREE_VALUE (attr);
1698 align = TREE_VALUE (attr);
1699 if (!tree_fits_uhwi_p (align))
1700 return ptrval;
1701 aligni = tree_to_uhwi (align);
1702 if (alloc_aligned)
1703 {
1704 if (aligni == 0 || aligni > gimple_call_num_args (stmt))
1705 return ptrval;
1706 align = gimple_call_arg (stmt, aligni - 1);
1707 if (!tree_fits_uhwi_p (align))
1708 return ptrval;
1709 aligni = tree_to_uhwi (align);
1710 }
1711 else if (TREE_CHAIN (attr) && TREE_VALUE (TREE_CHAIN (attr)))
1712 {
1713 misalign = TREE_VALUE (TREE_CHAIN (attr));
1714 if (!tree_fits_uhwi_p (misalign))
1715 return ptrval;
1716 misaligni = tree_to_uhwi (misalign);
1717 }
1718 }
1719 if (aligni <= 1 || (aligni & (aligni - 1)) != 0 || misaligni >= aligni)
1720 return ptrval;
1721
1722 align = build_int_cst_type (type, -aligni);
1723 alignval = get_value_for_expr (align, true);
1724 bit_value_binop (BIT_AND_EXPR, TYPE_SIGN (type), TYPE_PRECISION (type), &value, &mask,
1725 TYPE_SIGN (type), TYPE_PRECISION (type), value_to_wide_int (ptrval), ptrval.mask,
1726 TYPE_SIGN (type), TYPE_PRECISION (type), value_to_wide_int (alignval), alignval.mask);
1727
1728 if (wi::sext (mask, TYPE_PRECISION (type)) != -1)
1729 {
1730 val.lattice_val = CONSTANT;
1731 val.mask = mask;
1732 gcc_assert ((mask.to_uhwi () & (aligni - 1)) == 0);
1733 gcc_assert ((value.to_uhwi () & (aligni - 1)) == 0);
1734 value |= misaligni;
1735 /* ??? Delay building trees here. */
1736 val.value = wide_int_to_tree (type, value);
1737 }
1738 else
1739 {
1740 val.lattice_val = VARYING;
1741 val.value = NULL_TREE;
1742 val.mask = -1;
1743 }
1744 return val;
1745}
1746
1747/* Evaluate statement STMT.
1748 Valid only for assignments, calls, conditionals, and switches. */
1749
1750static ccp_prop_value_t
1751evaluate_stmt (gimple *stmt)
1752{
1753 ccp_prop_value_t val;
1754 tree simplified = NULL_TREE;
1755 ccp_lattice_t likelyvalue = likely_value (stmt);
1756 bool is_constant = false;
1757 unsigned int align;
1758
1759 if (dump_file && (dump_flags & TDF_DETAILS))
1760 {
1761 fprintf (dump_file, "which is likely ");
1762 switch (likelyvalue)
1763 {
1764 case CONSTANT:
1765 fprintf (dump_file, "CONSTANT");
1766 break;
1767 case UNDEFINED:
1768 fprintf (dump_file, "UNDEFINED");
1769 break;
1770 case VARYING:
1771 fprintf (dump_file, "VARYING");
1772 break;
1773 default:;
1774 }
1775 fprintf (dump_file, "\n");
1776 }
1777
1778 /* If the statement is likely to have a CONSTANT result, then try
1779 to fold the statement to determine the constant value. */
1780 /* FIXME. This is the only place that we call ccp_fold.
1781 Since likely_value never returns CONSTANT for calls, we will
1782 not attempt to fold them, including builtins that may profit. */
1783 if (likelyvalue == CONSTANT)
1784 {
1785 fold_defer_overflow_warnings ();
1786 simplified = ccp_fold (stmt);
1787 if (simplified
1788 && TREE_CODE (simplified) == SSA_NAME)
1789 {
1790 /* We may not use values of something that may be simulated again,
1791 see valueize_op_1. */
1792 if (SSA_NAME_IS_DEFAULT_DEF (simplified)
1793 || ! prop_simulate_again_p (SSA_NAME_DEF_STMT (simplified)))
1794 {
1795 ccp_prop_value_t *val = get_value (simplified);
1796 if (val && val->lattice_val != VARYING)
1797 {
1798 fold_undefer_overflow_warnings (true, stmt, 0);
1799 return *val;
1800 }
1801 }
1802 else
1803 /* We may also not place a non-valueized copy in the lattice
1804 as that might become stale if we never re-visit this stmt. */
1805 simplified = NULL_TREE;
1806 }
1807 is_constant = simplified && is_gimple_min_invariant (simplified);
1808 fold_undefer_overflow_warnings (is_constant, stmt, 0);
1809 if (is_constant)
1810 {
1811 /* The statement produced a constant value. */
1812 val.lattice_val = CONSTANT;
1813 val.value = simplified;
1814 val.mask = 0;
1815 return val;
1816 }
1817 }
1818 /* If the statement is likely to have a VARYING result, then do not
1819 bother folding the statement. */
1820 else if (likelyvalue == VARYING)
1821 {
1822 enum gimple_code code = gimple_code (stmt);
1823 if (code == GIMPLE_ASSIGN)
1824 {
1825 enum tree_code subcode = gimple_assign_rhs_code (stmt);
1826
1827 /* Other cases cannot satisfy is_gimple_min_invariant
1828 without folding. */
1829 if (get_gimple_rhs_class (subcode) == GIMPLE_SINGLE_RHS)
1830 simplified = gimple_assign_rhs1 (stmt);
1831 }
1832 else if (code == GIMPLE_SWITCH)
1833 simplified = gimple_switch_index (as_a <gswitch *> (stmt));
1834 else
1835 /* These cannot satisfy is_gimple_min_invariant without folding. */
1836 gcc_assert (code == GIMPLE_CALL || code == GIMPLE_COND);
1837 is_constant = simplified && is_gimple_min_invariant (simplified);
1838 if (is_constant)
1839 {
1840 /* The statement produced a constant value. */
1841 val.lattice_val = CONSTANT;
1842 val.value = simplified;
1843 val.mask = 0;
1844 }
1845 }
1846 /* If the statement result is likely UNDEFINED, make it so. */
1847 else if (likelyvalue == UNDEFINED)
1848 {
1849 val.lattice_val = UNDEFINED;
1850 val.value = NULL_TREE;
1851 val.mask = 0;
1852 return val;
1853 }
1854
1855 /* Resort to simplification for bitwise tracking. */
1856 if (flag_tree_bit_ccp
1857 && (likelyvalue == CONSTANT || is_gimple_call (stmt)
1858 || (gimple_assign_single_p (stmt)
1859 && gimple_assign_rhs_code (stmt) == ADDR_EXPR))
1860 && !is_constant)
1861 {
1862 enum gimple_code code = gimple_code (stmt);
1863 val.lattice_val = VARYING;
1864 val.value = NULL_TREE;
1865 val.mask = -1;
1866 if (code == GIMPLE_ASSIGN)
1867 {
1868 enum tree_code subcode = gimple_assign_rhs_code (stmt);
1869 tree rhs1 = gimple_assign_rhs1 (stmt);
1870 tree lhs = gimple_assign_lhs (stmt);
1871 if ((INTEGRAL_TYPE_P (TREE_TYPE (lhs))
1872 || POINTER_TYPE_P (TREE_TYPE (lhs)))
1873 && (INTEGRAL_TYPE_P (TREE_TYPE (rhs1))
1874 || POINTER_TYPE_P (TREE_TYPE (rhs1))))
1875 switch (get_gimple_rhs_class (subcode))
1876 {
1877 case GIMPLE_SINGLE_RHS:
1878 val = get_value_for_expr (rhs1, true);
1879 break;
1880
1881 case GIMPLE_UNARY_RHS:
1882 val = bit_value_unop (subcode, TREE_TYPE (lhs), rhs1);
1883 break;
1884
1885 case GIMPLE_BINARY_RHS:
1886 val = bit_value_binop (subcode, TREE_TYPE (lhs), rhs1,
1887 gimple_assign_rhs2 (stmt));
1888 break;
1889
1890 default:;
1891 }
1892 }
1893 else if (code == GIMPLE_COND)
1894 {
1895 enum tree_code code = gimple_cond_code (stmt);
1896 tree rhs1 = gimple_cond_lhs (stmt);
1897 tree rhs2 = gimple_cond_rhs (stmt);
1898 if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1))
1899 || POINTER_TYPE_P (TREE_TYPE (rhs1)))
1900 val = bit_value_binop (code, TREE_TYPE (rhs1), rhs1, rhs2);
1901 }
1902 else if (gimple_call_builtin_p (stmt, BUILT_IN_NORMAL))
1903 {
1904 tree fndecl = gimple_call_fndecl (stmt);
1905 switch (DECL_FUNCTION_CODE (fndecl))
1906 {
1907 case BUILT_IN_MALLOC:
1908 case BUILT_IN_REALLOC:
1909 case BUILT_IN_CALLOC:
1910 case BUILT_IN_STRDUP:
1911 case BUILT_IN_STRNDUP:
1912 val.lattice_val = CONSTANT;
1913 val.value = build_int_cst (TREE_TYPE (gimple_get_lhs (stmt)), 0);
1914 val.mask = ~((HOST_WIDE_INT) MALLOC_ABI_ALIGNMENT
1915 / BITS_PER_UNIT - 1);
1916 break;
1917
1918 CASE_BUILT_IN_ALLOCA:
1919 align = (DECL_FUNCTION_CODE (fndecl) == BUILT_IN_ALLOCA
1920 ? BIGGEST_ALIGNMENT
1921 : TREE_INT_CST_LOW (gimple_call_arg (stmt, 1)));
1922 val.lattice_val = CONSTANT;
1923 val.value = build_int_cst (TREE_TYPE (gimple_get_lhs (stmt)), 0);
1924 val.mask = ~((HOST_WIDE_INT) align / BITS_PER_UNIT - 1);
1925 break;
1926
1927 /* These builtins return their first argument, unmodified. */
1928 case BUILT_IN_MEMCPY:
1929 case BUILT_IN_MEMMOVE:
1930 case BUILT_IN_MEMSET:
1931 case BUILT_IN_STRCPY:
1932 case BUILT_IN_STRNCPY:
1933 case BUILT_IN_MEMCPY_CHK:
1934 case BUILT_IN_MEMMOVE_CHK:
1935 case BUILT_IN_MEMSET_CHK:
1936 case BUILT_IN_STRCPY_CHK:
1937 case BUILT_IN_STRNCPY_CHK:
1938 val = get_value_for_expr (gimple_call_arg (stmt, 0), true);
1939 break;
1940
1941 case BUILT_IN_ASSUME_ALIGNED:
1942 val = bit_value_assume_aligned (stmt, NULL_TREE, val, false);
1943 break;
1944
1945 case BUILT_IN_ALIGNED_ALLOC:
1946 {
1947 tree align = get_constant_value (gimple_call_arg (stmt, 0));
1948 if (align
1949 && tree_fits_uhwi_p (align))
1950 {
1951 unsigned HOST_WIDE_INT aligni = tree_to_uhwi (align);
1952 if (aligni > 1
1953 /* align must be power-of-two */
1954 && (aligni & (aligni - 1)) == 0)
1955 {
1956 val.lattice_val = CONSTANT;
1957 val.value = build_int_cst (ptr_type_node, 0);
1958 val.mask = -aligni;
1959 }
1960 }
1961 break;
1962 }
1963
1964 default:;
1965 }
1966 }
1967 if (is_gimple_call (stmt) && gimple_call_lhs (stmt))
1968 {
1969 tree fntype = gimple_call_fntype (stmt);
1970 if (fntype)
1971 {
1972 tree attrs = lookup_attribute ("assume_aligned",
1973 TYPE_ATTRIBUTES (fntype));
1974 if (attrs)
1975 val = bit_value_assume_aligned (stmt, attrs, val, false);
1976 attrs = lookup_attribute ("alloc_align",
1977 TYPE_ATTRIBUTES (fntype));
1978 if (attrs)
1979 val = bit_value_assume_aligned (stmt, attrs, val, true);
1980 }
1981 }
1982 is_constant = (val.lattice_val == CONSTANT);
1983 }
1984
1985 if (flag_tree_bit_ccp
1986 && ((is_constant && TREE_CODE (val.value) == INTEGER_CST)
1987 || !is_constant)
1988 && gimple_get_lhs (stmt)
1989 && TREE_CODE (gimple_get_lhs (stmt)) == SSA_NAME)
1990 {
1991 tree lhs = gimple_get_lhs (stmt);
1992 wide_int nonzero_bits = get_nonzero_bits (lhs);
1993 if (nonzero_bits != -1)
1994 {
1995 if (!is_constant)
1996 {
1997 val.lattice_val = CONSTANT;
1998 val.value = build_zero_cst (TREE_TYPE (lhs));
1999 val.mask = extend_mask (nonzero_bits, TYPE_SIGN (TREE_TYPE (lhs)));
2000 is_constant = true;
2001 }
2002 else
2003 {
2004 if (wi::bit_and_not (wi::to_wide (val.value), nonzero_bits) != 0)
2005 val.value = wide_int_to_tree (TREE_TYPE (lhs),
2006 nonzero_bits
2007 & wi::to_wide (val.value));
2008 if (nonzero_bits == 0)
2009 val.mask = 0;
2010 else
2011 val.mask = val.mask & extend_mask (nonzero_bits,
2012 TYPE_SIGN (TREE_TYPE (lhs)));
2013 }
2014 }
2015 }
2016
2017 /* The statement produced a nonconstant value. */
2018 if (!is_constant)
2019 {
2020 /* The statement produced a copy. */
2021 if (simplified && TREE_CODE (simplified) == SSA_NAME
2022 && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (simplified))
2023 {
2024 val.lattice_val = CONSTANT;
2025 val.value = simplified;
2026 val.mask = -1;
2027 }
2028 /* The statement is VARYING. */
2029 else
2030 {
2031 val.lattice_val = VARYING;
2032 val.value = NULL_TREE;
2033 val.mask = -1;
2034 }
2035 }
2036
2037 return val;
2038}
2039
2040typedef hash_table<nofree_ptr_hash<gimple> > gimple_htab;
2041
2042/* Given a BUILT_IN_STACK_SAVE value SAVED_VAL, insert a clobber of VAR before
2043 each matching BUILT_IN_STACK_RESTORE. Mark visited phis in VISITED. */
2044
2045static void
2046insert_clobber_before_stack_restore (tree saved_val, tree var,
2047 gimple_htab **visited)
2048{
2049 gimple *stmt;
2050 gassign *clobber_stmt;
2051 tree clobber;
2052 imm_use_iterator iter;
2053 gimple_stmt_iterator i;
2054 gimple **slot;
2055
2056 FOR_EACH_IMM_USE_STMT (stmt, iter, saved_val)
2057 if (gimple_call_builtin_p (stmt, BUILT_IN_STACK_RESTORE))
2058 {
2059 clobber = build_constructor (TREE_TYPE (var),
2060 NULL);
2061 TREE_THIS_VOLATILE (clobber) = 1;
2062 clobber_stmt = gimple_build_assign (var, clobber);
2063
2064 i = gsi_for_stmt (stmt);
2065 gsi_insert_before (&i, clobber_stmt, GSI_SAME_STMT);
2066 }
2067 else if (gimple_code (stmt) == GIMPLE_PHI)
2068 {
2069 if (!*visited)
2070 *visited = new gimple_htab (10);
2071
2072 slot = (*visited)->find_slot (stmt, INSERT);
2073 if (*slot != NULL)
2074 continue;
2075
2076 *slot = stmt;
2077 insert_clobber_before_stack_restore (gimple_phi_result (stmt), var,
2078 visited);
2079 }
2080 else if (gimple_assign_ssa_name_copy_p (stmt))
2081 insert_clobber_before_stack_restore (gimple_assign_lhs (stmt), var,
2082 visited);
2083 else if (chkp_gimple_call_builtin_p (stmt, BUILT_IN_CHKP_BNDRET))
2084 continue;
2085 else
2086 gcc_assert (is_gimple_debug (stmt));
2087}
2088
2089/* Advance the iterator to the previous non-debug gimple statement in the same
2090 or dominating basic block. */
2091
2092static inline void
2093gsi_prev_dom_bb_nondebug (gimple_stmt_iterator *i)
2094{
2095 basic_block dom;
2096
2097 gsi_prev_nondebug (i);
2098 while (gsi_end_p (*i))
2099 {
2100 dom = get_immediate_dominator (CDI_DOMINATORS, i->bb);
2101 if (dom == NULL || dom == ENTRY_BLOCK_PTR_FOR_FN (cfun))
2102 return;
2103
2104 *i = gsi_last_bb (dom);
2105 }
2106}
2107
2108/* Find a BUILT_IN_STACK_SAVE dominating gsi_stmt (I), and insert
2109 a clobber of VAR before each matching BUILT_IN_STACK_RESTORE.
2110
2111 It is possible that BUILT_IN_STACK_SAVE cannot be find in a dominator when a
2112 previous pass (such as DOM) duplicated it along multiple paths to a BB. In
2113 that case the function gives up without inserting the clobbers. */
2114
2115static void
2116insert_clobbers_for_var (gimple_stmt_iterator i, tree var)
2117{
2118 gimple *stmt;
2119 tree saved_val;
2120 gimple_htab *visited = NULL;
2121
2122 for (; !gsi_end_p (i); gsi_prev_dom_bb_nondebug (&i))
2123 {
2124 stmt = gsi_stmt (i);
2125
2126 if (!gimple_call_builtin_p (stmt, BUILT_IN_STACK_SAVE))
2127 continue;
2128
2129 saved_val = gimple_call_lhs (stmt);
2130 if (saved_val == NULL_TREE)
2131 continue;
2132
2133 insert_clobber_before_stack_restore (saved_val, var, &visited);
2134 break;
2135 }
2136
2137 delete visited;
2138}
2139
2140/* Detects a __builtin_alloca_with_align with constant size argument. Declares
2141 fixed-size array and returns the address, if found, otherwise returns
2142 NULL_TREE. */
2143
2144static tree
2145fold_builtin_alloca_with_align (gimple *stmt)
2146{
2147 unsigned HOST_WIDE_INT size, threshold, n_elem;
2148 tree lhs, arg, block, var, elem_type, array_type;
2149
2150 /* Get lhs. */
2151 lhs = gimple_call_lhs (stmt);
2152 if (lhs == NULL_TREE)
2153 return NULL_TREE;
2154
2155 /* Detect constant argument. */
2156 arg = get_constant_value (gimple_call_arg (stmt, 0));
2157 if (arg == NULL_TREE
2158 || TREE_CODE (arg) != INTEGER_CST
2159 || !tree_fits_uhwi_p (arg))
2160 return NULL_TREE;
2161
2162 size = tree_to_uhwi (arg);
2163
2164 /* Heuristic: don't fold large allocas. */
2165 threshold = (unsigned HOST_WIDE_INT)PARAM_VALUE (PARAM_LARGE_STACK_FRAME);
2166 /* In case the alloca is located at function entry, it has the same lifetime
2167 as a declared array, so we allow a larger size. */
2168 block = gimple_block (stmt);
2169 if (!(cfun->after_inlining
2170 && block
2171 && TREE_CODE (BLOCK_SUPERCONTEXT (block)) == FUNCTION_DECL))
2172 threshold /= 10;
2173 if (size > threshold)
2174 return NULL_TREE;
2175
2176 /* Declare array. */
2177 elem_type = build_nonstandard_integer_type (BITS_PER_UNIT, 1);
2178 n_elem = size * 8 / BITS_PER_UNIT;
2179 array_type = build_array_type_nelts (elem_type, n_elem);
2180 var = create_tmp_var (array_type);
2181 SET_DECL_ALIGN (var, TREE_INT_CST_LOW (gimple_call_arg (stmt, 1)));
2182 {
2183 struct ptr_info_def *pi = SSA_NAME_PTR_INFO (lhs);
2184 if (pi != NULL && !pi->pt.anything)
2185 {
2186 bool singleton_p;
2187 unsigned uid;
2188 singleton_p = pt_solution_singleton_or_null_p (&pi->pt, &uid);
2189 gcc_assert (singleton_p);
2190 SET_DECL_PT_UID (var, uid);
2191 }
2192 }
2193
2194 /* Fold alloca to the address of the array. */
2195 return fold_convert (TREE_TYPE (lhs), build_fold_addr_expr (var));
2196}
2197
2198/* Fold the stmt at *GSI with CCP specific information that propagating
2199 and regular folding does not catch. */
2200
2201bool
2202ccp_folder::fold_stmt (gimple_stmt_iterator *gsi)
2203{
2204 gimple *stmt = gsi_stmt (*gsi);
2205
2206 switch (gimple_code (stmt))
2207 {
2208 case GIMPLE_COND:
2209 {
2210 gcond *cond_stmt = as_a <gcond *> (stmt);
2211 ccp_prop_value_t val;
2212 /* Statement evaluation will handle type mismatches in constants
2213 more gracefully than the final propagation. This allows us to
2214 fold more conditionals here. */
2215 val = evaluate_stmt (stmt);
2216 if (val.lattice_val != CONSTANT
2217 || val.mask != 0)
2218 return false;
2219
2220 if (dump_file)
2221 {
2222 fprintf (dump_file, "Folding predicate ");
2223 print_gimple_expr (dump_file, stmt, 0);
2224 fprintf (dump_file, " to ");
2225 print_generic_expr (dump_file, val.value);
2226 fprintf (dump_file, "\n");
2227 }
2228
2229 if (integer_zerop (val.value))
2230 gimple_cond_make_false (cond_stmt);
2231 else
2232 gimple_cond_make_true (cond_stmt);
2233
2234 return true;
2235 }
2236
2237 case GIMPLE_CALL:
2238 {
2239 tree lhs = gimple_call_lhs (stmt);
2240 int flags = gimple_call_flags (stmt);
2241 tree val;
2242 tree argt;
2243 bool changed = false;
2244 unsigned i;
2245
2246 /* If the call was folded into a constant make sure it goes
2247 away even if we cannot propagate into all uses because of
2248 type issues. */
2249 if (lhs
2250 && TREE_CODE (lhs) == SSA_NAME
2251 && (val = get_constant_value (lhs))
2252 /* Don't optimize away calls that have side-effects. */
2253 && (flags & (ECF_CONST|ECF_PURE)) != 0
2254 && (flags & ECF_LOOPING_CONST_OR_PURE) == 0)
2255 {
2256 tree new_rhs = unshare_expr (val);
2257 bool res;
2258 if (!useless_type_conversion_p (TREE_TYPE (lhs),
2259 TREE_TYPE (new_rhs)))
2260 new_rhs = fold_convert (TREE_TYPE (lhs), new_rhs);
2261 res = update_call_from_tree (gsi, new_rhs);
2262 gcc_assert (res);
2263 return true;
2264 }
2265
2266 /* Internal calls provide no argument types, so the extra laxity
2267 for normal calls does not apply. */
2268 if (gimple_call_internal_p (stmt))
2269 return false;
2270
2271 /* The heuristic of fold_builtin_alloca_with_align differs before and
2272 after inlining, so we don't require the arg to be changed into a
2273 constant for folding, but just to be constant. */
2274 if (gimple_call_builtin_p (stmt, BUILT_IN_ALLOCA_WITH_ALIGN)
2275 || gimple_call_builtin_p (stmt, BUILT_IN_ALLOCA_WITH_ALIGN_AND_MAX))
2276 {
2277 tree new_rhs = fold_builtin_alloca_with_align (stmt);
2278 if (new_rhs)
2279 {
2280 bool res = update_call_from_tree (gsi, new_rhs);
2281 tree var = TREE_OPERAND (TREE_OPERAND (new_rhs, 0),0);
2282 gcc_assert (res);
2283 insert_clobbers_for_var (*gsi, var);
2284 return true;
2285 }
2286 }
2287
2288 /* Propagate into the call arguments. Compared to replace_uses_in
2289 this can use the argument slot types for type verification
2290 instead of the current argument type. We also can safely
2291 drop qualifiers here as we are dealing with constants anyway. */
2292 argt = TYPE_ARG_TYPES (gimple_call_fntype (stmt));
2293 for (i = 0; i < gimple_call_num_args (stmt) && argt;
2294 ++i, argt = TREE_CHAIN (argt))
2295 {
2296 tree arg = gimple_call_arg (stmt, i);
2297 if (TREE_CODE (arg) == SSA_NAME
2298 && (val = get_constant_value (arg))
2299 && useless_type_conversion_p
2300 (TYPE_MAIN_VARIANT (TREE_VALUE (argt)),
2301 TYPE_MAIN_VARIANT (TREE_TYPE (val))))
2302 {
2303 gimple_call_set_arg (stmt, i, unshare_expr (val));
2304 changed = true;
2305 }
2306 }
2307
2308 return changed;
2309 }
2310
2311 case GIMPLE_ASSIGN:
2312 {
2313 tree lhs = gimple_assign_lhs (stmt);
2314 tree val;
2315
2316 /* If we have a load that turned out to be constant replace it
2317 as we cannot propagate into all uses in all cases. */
2318 if (gimple_assign_single_p (stmt)
2319 && TREE_CODE (lhs) == SSA_NAME
2320 && (val = get_constant_value (lhs)))
2321 {
2322 tree rhs = unshare_expr (val);
2323 if (!useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (rhs)))
2324 rhs = fold_build1 (VIEW_CONVERT_EXPR, TREE_TYPE (lhs), rhs);
2325 gimple_assign_set_rhs_from_tree (gsi, rhs);
2326 return true;
2327 }
2328
2329 return false;
2330 }
2331
2332 default:
2333 return false;
2334 }
2335}
2336
2337/* Visit the assignment statement STMT. Set the value of its LHS to the
2338 value computed by the RHS and store LHS in *OUTPUT_P. If STMT
2339 creates virtual definitions, set the value of each new name to that
2340 of the RHS (if we can derive a constant out of the RHS).
2341 Value-returning call statements also perform an assignment, and
2342 are handled here. */
2343
2344static enum ssa_prop_result
2345visit_assignment (gimple *stmt, tree *output_p)
2346{
2347 ccp_prop_value_t val;
2348 enum ssa_prop_result retval = SSA_PROP_NOT_INTERESTING;
2349
2350 tree lhs = gimple_get_lhs (stmt);
2351 if (TREE_CODE (lhs) == SSA_NAME)
2352 {
2353 /* Evaluate the statement, which could be
2354 either a GIMPLE_ASSIGN or a GIMPLE_CALL. */
2355 val = evaluate_stmt (stmt);
2356
2357 /* If STMT is an assignment to an SSA_NAME, we only have one
2358 value to set. */
2359 if (set_lattice_value (lhs, &val))
2360 {
2361 *output_p = lhs;
2362 if (val.lattice_val == VARYING)
2363 retval = SSA_PROP_VARYING;
2364 else
2365 retval = SSA_PROP_INTERESTING;
2366 }
2367 }
2368
2369 return retval;
2370}
2371
2372
2373/* Visit the conditional statement STMT. Return SSA_PROP_INTERESTING
2374 if it can determine which edge will be taken. Otherwise, return
2375 SSA_PROP_VARYING. */
2376
2377static enum ssa_prop_result
2378visit_cond_stmt (gimple *stmt, edge *taken_edge_p)
2379{
2380 ccp_prop_value_t val;
2381 basic_block block;
2382
2383 block = gimple_bb (stmt);
2384 val = evaluate_stmt (stmt);
2385 if (val.lattice_val != CONSTANT
2386 || val.mask != 0)
2387 return SSA_PROP_VARYING;
2388
2389 /* Find which edge out of the conditional block will be taken and add it
2390 to the worklist. If no single edge can be determined statically,
2391 return SSA_PROP_VARYING to feed all the outgoing edges to the
2392 propagation engine. */
2393 *taken_edge_p = find_taken_edge (block, val.value);
2394 if (*taken_edge_p)
2395 return SSA_PROP_INTERESTING;
2396 else
2397 return SSA_PROP_VARYING;
2398}
2399
2400
2401/* Evaluate statement STMT. If the statement produces an output value and
2402 its evaluation changes the lattice value of its output, return
2403 SSA_PROP_INTERESTING and set *OUTPUT_P to the SSA_NAME holding the
2404 output value.
2405
2406 If STMT is a conditional branch and we can determine its truth
2407 value, set *TAKEN_EDGE_P accordingly. If STMT produces a varying
2408 value, return SSA_PROP_VARYING. */
2409
2410enum ssa_prop_result
2411ccp_propagate::visit_stmt (gimple *stmt, edge *taken_edge_p, tree *output_p)
2412{
2413 tree def;
2414 ssa_op_iter iter;
2415
2416 if (dump_file && (dump_flags & TDF_DETAILS))
2417 {
2418 fprintf (dump_file, "\nVisiting statement:\n");
2419 print_gimple_stmt (dump_file, stmt, 0, dump_flags);
2420 }
2421
2422 switch (gimple_code (stmt))
2423 {
2424 case GIMPLE_ASSIGN:
2425 /* If the statement is an assignment that produces a single
2426 output value, evaluate its RHS to see if the lattice value of
2427 its output has changed. */
2428 return visit_assignment (stmt, output_p);
2429
2430 case GIMPLE_CALL:
2431 /* A value-returning call also performs an assignment. */
2432 if (gimple_call_lhs (stmt) != NULL_TREE)
2433 return visit_assignment (stmt, output_p);
2434 break;
2435
2436 case GIMPLE_COND:
2437 case GIMPLE_SWITCH:
2438 /* If STMT is a conditional branch, see if we can determine
2439 which branch will be taken. */
2440 /* FIXME. It appears that we should be able to optimize
2441 computed GOTOs here as well. */
2442 return visit_cond_stmt (stmt, taken_edge_p);
2443
2444 default:
2445 break;
2446 }
2447
2448 /* Any other kind of statement is not interesting for constant
2449 propagation and, therefore, not worth simulating. */
2450 if (dump_file && (dump_flags & TDF_DETAILS))
2451 fprintf (dump_file, "No interesting values produced. Marked VARYING.\n");
2452
2453 /* Definitions made by statements other than assignments to
2454 SSA_NAMEs represent unknown modifications to their outputs.
2455 Mark them VARYING. */
2456 FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_ALL_DEFS)
2457 set_value_varying (def);
2458
2459 return SSA_PROP_VARYING;
2460}
2461
2462
2463/* Main entry point for SSA Conditional Constant Propagation. If NONZERO_P,
2464 record nonzero bits. */
2465
2466static unsigned int
2467do_ssa_ccp (bool nonzero_p)
2468{
2469 unsigned int todo = 0;
2470 calculate_dominance_info (CDI_DOMINATORS);
2471
2472 ccp_initialize ();
2473 class ccp_propagate ccp_propagate;
2474 ccp_propagate.ssa_propagate ();
2475 if (ccp_finalize (nonzero_p || flag_ipa_bit_cp))
2476 {
2477 todo = (TODO_cleanup_cfg | TODO_update_ssa);
2478
2479 /* ccp_finalize does not preserve loop-closed ssa. */
2480 loops_state_clear (LOOP_CLOSED_SSA);
2481 }
2482
2483 free_dominance_info (CDI_DOMINATORS);
2484 return todo;
2485}
2486
2487
2488namespace {
2489
2490const pass_data pass_data_ccp =
2491{
2492 GIMPLE_PASS, /* type */
2493 "ccp", /* name */
2494 OPTGROUP_NONE, /* optinfo_flags */
2495 TV_TREE_CCP, /* tv_id */
2496 ( PROP_cfg | PROP_ssa ), /* properties_required */
2497 0, /* properties_provided */
2498 0, /* properties_destroyed */
2499 0, /* todo_flags_start */
2500 TODO_update_address_taken, /* todo_flags_finish */
2501};
2502
2503class pass_ccp : public gimple_opt_pass
2504{
2505public:
2506 pass_ccp (gcc::context *ctxt)
2507 : gimple_opt_pass (pass_data_ccp, ctxt), nonzero_p (false)
2508 {}
2509
2510 /* opt_pass methods: */
2511 opt_pass * clone () { return new pass_ccp (m_ctxt); }
2512 void set_pass_param (unsigned int n, bool param)
2513 {
2514 gcc_assert (n == 0);
2515 nonzero_p = param;
2516 }
2517 virtual bool gate (function *) { return flag_tree_ccp != 0; }
2518 virtual unsigned int execute (function *) { return do_ssa_ccp (nonzero_p); }
2519
2520 private:
2521 /* Determines whether the pass instance records nonzero bits. */
2522 bool nonzero_p;
2523}; // class pass_ccp
2524
2525} // anon namespace
2526
2527gimple_opt_pass *
2528make_pass_ccp (gcc::context *ctxt)
2529{
2530 return new pass_ccp (ctxt);
2531}
2532
2533
2534
2535/* Try to optimize out __builtin_stack_restore. Optimize it out
2536 if there is another __builtin_stack_restore in the same basic
2537 block and no calls or ASM_EXPRs are in between, or if this block's
2538 only outgoing edge is to EXIT_BLOCK and there are no calls or
2539 ASM_EXPRs after this __builtin_stack_restore. */
2540
2541static tree
2542optimize_stack_restore (gimple_stmt_iterator i)
2543{
2544 tree callee;
2545 gimple *stmt;
2546
2547 basic_block bb = gsi_bb (i);
2548 gimple *call = gsi_stmt (i);
2549
2550 if (gimple_code (call) != GIMPLE_CALL
2551 || gimple_call_num_args (call) != 1
2552 || TREE_CODE (gimple_call_arg (call, 0)) != SSA_NAME
2553 || !POINTER_TYPE_P (TREE_TYPE (gimple_call_arg (call, 0))))
2554 return NULL_TREE;
2555
2556 for (gsi_next (&i); !gsi_end_p (i); gsi_next (&i))
2557 {
2558 stmt = gsi_stmt (i);
2559 if (gimple_code (stmt) == GIMPLE_ASM)
2560 return NULL_TREE;
2561 if (gimple_code (stmt) != GIMPLE_CALL)
2562 continue;
2563
2564 callee = gimple_call_fndecl (stmt);
2565 if (!callee
2566 || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL
2567 /* All regular builtins are ok, just obviously not alloca. */
2568 || ALLOCA_FUNCTION_CODE_P (DECL_FUNCTION_CODE (callee)))
2569 return NULL_TREE;
2570
2571 if (DECL_FUNCTION_CODE (callee) == BUILT_IN_STACK_RESTORE)
2572 goto second_stack_restore;
2573 }
2574
2575 if (!gsi_end_p (i))
2576 return NULL_TREE;
2577
2578 /* Allow one successor of the exit block, or zero successors. */
2579 switch (EDGE_COUNT (bb->succs))
2580 {
2581 case 0:
2582 break;
2583 case 1:
2584 if (single_succ_edge (bb)->dest != EXIT_BLOCK_PTR_FOR_FN (cfun))
2585 return NULL_TREE;
2586 break;
2587 default:
2588 return NULL_TREE;
2589 }
2590 second_stack_restore:
2591
2592 /* If there's exactly one use, then zap the call to __builtin_stack_save.
2593 If there are multiple uses, then the last one should remove the call.
2594 In any case, whether the call to __builtin_stack_save can be removed
2595 or not is irrelevant to removing the call to __builtin_stack_restore. */
2596 if (has_single_use (gimple_call_arg (call, 0)))
2597 {
2598 gimple *stack_save = SSA_NAME_DEF_STMT (gimple_call_arg (call, 0));
2599 if (is_gimple_call (stack_save))
2600 {
2601 callee = gimple_call_fndecl (stack_save);
2602 if (callee
2603 && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL
2604 && DECL_FUNCTION_CODE (callee) == BUILT_IN_STACK_SAVE)
2605 {
2606 gimple_stmt_iterator stack_save_gsi;
2607 tree rhs;
2608
2609 stack_save_gsi = gsi_for_stmt (stack_save);
2610 rhs = build_int_cst (TREE_TYPE (gimple_call_arg (call, 0)), 0);
2611 update_call_from_tree (&stack_save_gsi, rhs);
2612 }
2613 }
2614 }
2615
2616 /* No effect, so the statement will be deleted. */
2617 return integer_zero_node;
2618}
2619
2620/* If va_list type is a simple pointer and nothing special is needed,
2621 optimize __builtin_va_start (&ap, 0) into ap = __builtin_next_arg (0),
2622 __builtin_va_end (&ap) out as NOP and __builtin_va_copy into a simple
2623 pointer assignment. */
2624
2625static tree
2626optimize_stdarg_builtin (gimple *call)
2627{
2628 tree callee, lhs, rhs, cfun_va_list;
2629 bool va_list_simple_ptr;
2630 location_t loc = gimple_location (call);
2631
2632 if (gimple_code (call) != GIMPLE_CALL)
2633 return NULL_TREE;
2634
2635 callee = gimple_call_fndecl (call);
2636
2637 cfun_va_list = targetm.fn_abi_va_list (callee);
2638 va_list_simple_ptr = POINTER_TYPE_P (cfun_va_list)
2639 && (TREE_TYPE (cfun_va_list) == void_type_node
2640 || TREE_TYPE (cfun_va_list) == char_type_node);
2641
2642 switch (DECL_FUNCTION_CODE (callee))
2643 {
2644 case BUILT_IN_VA_START:
2645 if (!va_list_simple_ptr
2646 || targetm.expand_builtin_va_start != NULL
2647 || !builtin_decl_explicit_p (BUILT_IN_NEXT_ARG))
2648 return NULL_TREE;
2649
2650 if (gimple_call_num_args (call) != 2)
2651 return NULL_TREE;
2652
2653 lhs = gimple_call_arg (call, 0);
2654 if (!POINTER_TYPE_P (TREE_TYPE (lhs))
2655 || TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (lhs)))
2656 != TYPE_MAIN_VARIANT (cfun_va_list))
2657 return NULL_TREE;
2658
2659 lhs = build_fold_indirect_ref_loc (loc, lhs);
2660 rhs = build_call_expr_loc (loc, builtin_decl_explicit (BUILT_IN_NEXT_ARG),
2661 1, integer_zero_node);
2662 rhs = fold_convert_loc (loc, TREE_TYPE (lhs), rhs);
2663 return build2 (MODIFY_EXPR, TREE_TYPE (lhs), lhs, rhs);
2664
2665 case BUILT_IN_VA_COPY:
2666 if (!va_list_simple_ptr)
2667 return NULL_TREE;
2668
2669 if (gimple_call_num_args (call) != 2)
2670 return NULL_TREE;
2671
2672 lhs = gimple_call_arg (call, 0);
2673 if (!POINTER_TYPE_P (TREE_TYPE (lhs))
2674 || TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (lhs)))
2675 != TYPE_MAIN_VARIANT (cfun_va_list))
2676 return NULL_TREE;
2677
2678 lhs = build_fold_indirect_ref_loc (loc, lhs);
2679 rhs = gimple_call_arg (call, 1);
2680 if (TYPE_MAIN_VARIANT (TREE_TYPE (rhs))
2681 != TYPE_MAIN_VARIANT (cfun_va_list))
2682 return NULL_TREE;
2683
2684 rhs = fold_convert_loc (loc, TREE_TYPE (lhs), rhs);
2685 return build2 (MODIFY_EXPR, TREE_TYPE (lhs), lhs, rhs);
2686
2687 case BUILT_IN_VA_END:
2688 /* No effect, so the statement will be deleted. */
2689 return integer_zero_node;
2690
2691 default:
2692 gcc_unreachable ();
2693 }
2694}
2695
2696/* Attemp to make the block of __builtin_unreachable I unreachable by changing
2697 the incoming jumps. Return true if at least one jump was changed. */
2698
2699static bool
2700optimize_unreachable (gimple_stmt_iterator i)
2701{
2702 basic_block bb = gsi_bb (i);
2703 gimple_stmt_iterator gsi;
2704 gimple *stmt;
2705 edge_iterator ei;
2706 edge e;
2707 bool ret;
2708
2709 if (flag_sanitize & SANITIZE_UNREACHABLE)
2710 return false;
2711
2712 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
2713 {
2714 stmt = gsi_stmt (gsi);
2715
2716 if (is_gimple_debug (stmt))
2717 continue;
2718
2719 if (glabel *label_stmt = dyn_cast <glabel *> (stmt))
2720 {
2721 /* Verify we do not need to preserve the label. */
2722 if (FORCED_LABEL (gimple_label_label (label_stmt)))
2723 return false;
2724
2725 continue;
2726 }
2727
2728 /* Only handle the case that __builtin_unreachable is the first statement
2729 in the block. We rely on DCE to remove stmts without side-effects
2730 before __builtin_unreachable. */
2731 if (gsi_stmt (gsi) != gsi_stmt (i))
2732 return false;
2733 }
2734
2735 ret = false;
2736 FOR_EACH_EDGE (e, ei, bb->preds)
2737 {
2738 gsi = gsi_last_bb (e->src);
2739 if (gsi_end_p (gsi))
2740 continue;
2741
2742 stmt = gsi_stmt (gsi);
2743 if (gcond *cond_stmt = dyn_cast <gcond *> (stmt))
2744 {
2745 if (e->flags & EDGE_TRUE_VALUE)
2746 gimple_cond_make_false (cond_stmt);
2747 else if (e->flags & EDGE_FALSE_VALUE)
2748 gimple_cond_make_true (cond_stmt);
2749 else
2750 gcc_unreachable ();
2751 update_stmt (cond_stmt);
2752 }
2753 else
2754 {
2755 /* Todo: handle other cases. Note that unreachable switch case
2756 statements have already been removed. */
2757 continue;
2758 }
2759
2760 ret = true;
2761 }
2762
2763 return ret;
2764}
2765
2766/* Optimize
2767 mask_2 = 1 << cnt_1;
2768 _4 = __atomic_fetch_or_* (ptr_6, mask_2, _3);
2769 _5 = _4 & mask_2;
2770 to
2771 _4 = ATOMIC_BIT_TEST_AND_SET (ptr_6, cnt_1, 0, _3);
2772 _5 = _4;
2773 If _5 is only used in _5 != 0 or _5 == 0 comparisons, 1
2774 is passed instead of 0, and the builtin just returns a zero
2775 or 1 value instead of the actual bit.
2776 Similarly for __sync_fetch_and_or_* (without the ", _3" part
2777 in there), and/or if mask_2 is a power of 2 constant.
2778 Similarly for xor instead of or, use ATOMIC_BIT_TEST_AND_COMPLEMENT
2779 in that case. And similarly for and instead of or, except that
2780 the second argument to the builtin needs to be one's complement
2781 of the mask instead of mask. */
2782
2783static void
2784optimize_atomic_bit_test_and (gimple_stmt_iterator *gsip,
2785 enum internal_fn fn, bool has_model_arg,
2786 bool after)
2787{
2788 gimple *call = gsi_stmt (*gsip);
2789 tree lhs = gimple_call_lhs (call);
2790 use_operand_p use_p;
2791 gimple *use_stmt;
2792 tree mask, bit;
2793 optab optab;
2794
2795 if (!flag_inline_atomics
2796 || optimize_debug
2797 || !gimple_call_builtin_p (call, BUILT_IN_NORMAL)
2798 || !lhs
2799 || SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs)
2800 || !single_imm_use (lhs, &use_p, &use_stmt)
2801 || !is_gimple_assign (use_stmt)
2802 || gimple_assign_rhs_code (use_stmt) != BIT_AND_EXPR
2803 || !gimple_vdef (call))
2804 return;
2805
2806 switch (fn)
2807 {
2808 case IFN_ATOMIC_BIT_TEST_AND_SET:
2809 optab = atomic_bit_test_and_set_optab;
2810 break;
2811 case IFN_ATOMIC_BIT_TEST_AND_COMPLEMENT:
2812 optab = atomic_bit_test_and_complement_optab;
2813 break;
2814 case IFN_ATOMIC_BIT_TEST_AND_RESET:
2815 optab = atomic_bit_test_and_reset_optab;
2816 break;
2817 default:
2818 return;
2819 }
2820
2821 if (optab_handler (optab, TYPE_MODE (TREE_TYPE (lhs))) == CODE_FOR_nothing)
2822 return;
2823
2824 mask = gimple_call_arg (call, 1);
2825 tree use_lhs = gimple_assign_lhs (use_stmt);
2826 if (!use_lhs)
2827 return;
2828
2829 if (TREE_CODE (mask) == INTEGER_CST)
2830 {
2831 if (fn == IFN_ATOMIC_BIT_TEST_AND_RESET)
2832 mask = const_unop (BIT_NOT_EXPR, TREE_TYPE (mask), mask);
2833 mask = fold_convert (TREE_TYPE (lhs), mask);
2834 int ibit = tree_log2 (mask);
2835 if (ibit < 0)
2836 return;
2837 bit = build_int_cst (TREE_TYPE (lhs), ibit);
2838 }
2839 else if (TREE_CODE (mask) == SSA_NAME)
2840 {
2841 gimple *g = SSA_NAME_DEF_STMT (mask);
2842 if (fn == IFN_ATOMIC_BIT_TEST_AND_RESET)
2843 {
2844 if (!is_gimple_assign (g)
2845 || gimple_assign_rhs_code (g) != BIT_NOT_EXPR)
2846 return;
2847 mask = gimple_assign_rhs1 (g);
2848 if (TREE_CODE (mask) != SSA_NAME)
2849 return;
2850 g = SSA_NAME_DEF_STMT (mask);
2851 }
2852 if (!is_gimple_assign (g)
2853 || gimple_assign_rhs_code (g) != LSHIFT_EXPR
2854 || !integer_onep (gimple_assign_rhs1 (g)))
2855 return;
2856 bit = gimple_assign_rhs2 (g);
2857 }
2858 else
2859 return;
2860
2861 if (gimple_assign_rhs1 (use_stmt) == lhs)
2862 {
2863 if (!operand_equal_p (gimple_assign_rhs2 (use_stmt), mask, 0))
2864 return;
2865 }
2866 else if (gimple_assign_rhs2 (use_stmt) != lhs
2867 || !operand_equal_p (gimple_assign_rhs1 (use_stmt), mask, 0))
2868 return;
2869
2870 bool use_bool = true;
2871 bool has_debug_uses = false;
2872 imm_use_iterator iter;
2873 gimple *g;
2874
2875 if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (use_lhs))
2876 use_bool = false;
2877 FOR_EACH_IMM_USE_STMT (g, iter, use_lhs)
2878 {
2879 enum tree_code code = ERROR_MARK;
2880 tree op0 = NULL_TREE, op1 = NULL_TREE;
2881 if (is_gimple_debug (g))
2882 {
2883 has_debug_uses = true;
2884 continue;
2885 }
2886 else if (is_gimple_assign (g))
2887 switch (gimple_assign_rhs_code (g))
2888 {
2889 case COND_EXPR:
2890 op1 = gimple_assign_rhs1 (g);
2891 code = TREE_CODE (op1);
2892 op0 = TREE_OPERAND (op1, 0);
2893 op1 = TREE_OPERAND (op1, 1);
2894 break;
2895 case EQ_EXPR:
2896 case NE_EXPR:
2897 code = gimple_assign_rhs_code (g);
2898 op0 = gimple_assign_rhs1 (g);
2899 op1 = gimple_assign_rhs2 (g);
2900 break;
2901 default:
2902 break;
2903 }
2904 else if (gimple_code (g) == GIMPLE_COND)
2905 {
2906 code = gimple_cond_code (g);
2907 op0 = gimple_cond_lhs (g);
2908 op1 = gimple_cond_rhs (g);
2909 }
2910
2911 if ((code == EQ_EXPR || code == NE_EXPR)
2912 && op0 == use_lhs
2913 && integer_zerop (op1))
2914 {
2915 use_operand_p use_p;
2916 int n = 0;
2917 FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
2918 n++;
2919 if (n == 1)
2920 continue;
2921 }
2922
2923 use_bool = false;
2924 BREAK_FROM_IMM_USE_STMT (iter);
2925 }
2926
2927 tree new_lhs = make_ssa_name (TREE_TYPE (lhs));
2928 tree flag = build_int_cst (TREE_TYPE (lhs), use_bool);
2929 if (has_model_arg)
2930 g = gimple_build_call_internal (fn, 4, gimple_call_arg (call, 0),
2931 bit, flag, gimple_call_arg (call, 2));
2932 else
2933 g = gimple_build_call_internal (fn, 3, gimple_call_arg (call, 0),
2934 bit, flag);
2935 gimple_call_set_lhs (g, new_lhs);
2936 gimple_set_location (g, gimple_location (call));
2937 gimple_set_vuse (g, gimple_vuse (call));
2938 gimple_set_vdef (g, gimple_vdef (call));
2939 bool throws = stmt_can_throw_internal (call);
2940 gimple_call_set_nothrow (as_a <gcall *> (g),
2941 gimple_call_nothrow_p (as_a <gcall *> (call)));
2942 SSA_NAME_DEF_STMT (gimple_vdef (call)) = g;
2943 gimple_stmt_iterator gsi = *gsip;
2944 gsi_insert_after (&gsi, g, GSI_NEW_STMT);
2945 edge e = NULL;
2946 if (throws)
2947 {
2948 maybe_clean_or_replace_eh_stmt (call, g);
2949 if (after || (use_bool && has_debug_uses))
2950 e = find_fallthru_edge (gsi_bb (gsi)->succs);
2951 }
2952 if (after)
2953 {
2954 /* The internal function returns the value of the specified bit
2955 before the atomic operation. If we are interested in the value
2956 of the specified bit after the atomic operation (makes only sense
2957 for xor, otherwise the bit content is compile time known),
2958 we need to invert the bit. */
2959 g = gimple_build_assign (make_ssa_name (TREE_TYPE (lhs)),
2960 BIT_XOR_EXPR, new_lhs,
2961 use_bool ? build_int_cst (TREE_TYPE (lhs), 1)
2962 : mask);
2963 new_lhs = gimple_assign_lhs (g);
2964 if (throws)
2965 {
2966 gsi_insert_on_edge_immediate (e, g);
2967 gsi = gsi_for_stmt (g);
2968 }
2969 else
2970 gsi_insert_after (&gsi, g, GSI_NEW_STMT);
2971 }
2972 if (use_bool && has_debug_uses)
2973 {
2974 tree temp = NULL_TREE;
2975 if (!throws || after || single_pred_p (e->dest))
2976 {
2977 temp = make_node (DEBUG_EXPR_DECL);
2978 DECL_ARTIFICIAL (temp) = 1;
2979 TREE_TYPE (temp) = TREE_TYPE (lhs);
2980 SET_DECL_MODE (temp, TYPE_MODE (TREE_TYPE (lhs)));
2981 tree t = build2 (LSHIFT_EXPR, TREE_TYPE (lhs), new_lhs, bit);
2982 g = gimple_build_debug_bind (temp, t, g);
2983 if (throws && !after)
2984 {
2985 gsi = gsi_after_labels (e->dest);
2986 gsi_insert_before (&gsi, g, GSI_SAME_STMT);
2987 }
2988 else
2989 gsi_insert_after (&gsi, g, GSI_NEW_STMT);
2990 }
2991 FOR_EACH_IMM_USE_STMT (g, iter, use_lhs)
2992 if (is_gimple_debug (g))
2993 {
2994 use_operand_p use_p;
2995 if (temp == NULL_TREE)
2996 gimple_debug_bind_reset_value (g);
2997 else
2998 FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
2999 SET_USE (use_p, temp);
3000 update_stmt (g);
3001 }
3002 }
3003 SSA_NAME_OCCURS_IN_ABNORMAL_PHI (new_lhs)
3004 = SSA_NAME_OCCURS_IN_ABNORMAL_PHI (use_lhs);
3005 replace_uses_by (use_lhs, new_lhs);
3006 gsi = gsi_for_stmt (use_stmt);
3007 gsi_remove (&gsi, true);
3008 release_defs (use_stmt);
3009 gsi_remove (gsip, true);
3010 release_ssa_name (lhs);
3011}
3012
3013/* Optimize
3014 a = {};
3015 b = a;
3016 into
3017 a = {};
3018 b = {};
3019 Similarly for memset (&a, ..., sizeof (a)); instead of a = {};
3020 and/or memcpy (&b, &a, sizeof (a)); instead of b = a; */
3021
3022static void
3023optimize_memcpy (gimple_stmt_iterator *gsip, tree dest, tree src, tree len)
3024{
3025 gimple *stmt = gsi_stmt (*gsip);
3026 if (gimple_has_volatile_ops (stmt))
3027 return;
3028
3029 tree vuse = gimple_vuse (stmt);
3030 if (vuse == NULL)
3031 return;
3032
3033 gimple *defstmt = SSA_NAME_DEF_STMT (vuse);
3034 tree src2 = NULL_TREE, len2 = NULL_TREE;
3035 HOST_WIDE_INT offset, offset2;
3036 tree val = integer_zero_node;
3037 if (gimple_store_p (defstmt)
3038 && gimple_assign_single_p (defstmt)
3039 && TREE_CODE (gimple_assign_rhs1 (defstmt)) == CONSTRUCTOR
3040 && !gimple_clobber_p (defstmt))
3041 src2 = gimple_assign_lhs (defstmt);
3042 else if (gimple_call_builtin_p (defstmt, BUILT_IN_MEMSET)
3043 && TREE_CODE (gimple_call_arg (defstmt, 0)) == ADDR_EXPR
3044 && TREE_CODE (gimple_call_arg (defstmt, 1)) == INTEGER_CST)
3045 {
3046 src2 = TREE_OPERAND (gimple_call_arg (defstmt, 0), 0);
3047 len2 = gimple_call_arg (defstmt, 2);
3048 val = gimple_call_arg (defstmt, 1);
3049 /* For non-0 val, we'd have to transform stmt from assignment
3050 into memset (only if dest is addressable). */
3051 if (!integer_zerop (val) && is_gimple_assign (stmt))
3052 src2 = NULL_TREE;
3053 }
3054
3055 if (src2 == NULL_TREE)
3056 return;
3057
3058 if (len == NULL_TREE)
3059 len = (TREE_CODE (src) == COMPONENT_REF
3060 ? DECL_SIZE_UNIT (TREE_OPERAND (src, 1))
3061 : TYPE_SIZE_UNIT (TREE_TYPE (src)));
3062 if (len2 == NULL_TREE)
3063 len2 = (TREE_CODE (src2) == COMPONENT_REF
3064 ? DECL_SIZE_UNIT (TREE_OPERAND (src2, 1))
3065 : TYPE_SIZE_UNIT (TREE_TYPE (src2)));
3066 if (len == NULL_TREE
3067 || TREE_CODE (len) != INTEGER_CST
3068 || len2 == NULL_TREE
3069 || TREE_CODE (len2) != INTEGER_CST)
3070 return;
3071
3072 src = get_addr_base_and_unit_offset (src, &offset);
3073 src2 = get_addr_base_and_unit_offset (src2, &offset2);
3074 if (src == NULL_TREE
3075 || src2 == NULL_TREE
3076 || offset < offset2)
3077 return;
3078
3079 if (!operand_equal_p (src, src2, 0))
3080 return;
3081
3082 /* [ src + offset2, src + offset2 + len2 - 1 ] is set to val.
3083 Make sure that
3084 [ src + offset, src + offset + len - 1 ] is a subset of that. */
3085 if (wi::to_offset (len) + (offset - offset2) > wi::to_offset (len2))
3086 return;
3087
3088 if (dump_file && (dump_flags & TDF_DETAILS))
3089 {
3090 fprintf (dump_file, "Simplified\n ");
3091 print_gimple_stmt (dump_file, stmt, 0, dump_flags);
3092 fprintf (dump_file, "after previous\n ");
3093 print_gimple_stmt (dump_file, defstmt, 0, dump_flags);
3094 }
3095
3096 /* For simplicity, don't change the kind of the stmt,
3097 turn dest = src; into dest = {}; and memcpy (&dest, &src, len);
3098 into memset (&dest, val, len);
3099 In theory we could change dest = src into memset if dest
3100 is addressable (maybe beneficial if val is not 0), or
3101 memcpy (&dest, &src, len) into dest = {} if len is the size
3102 of dest, dest isn't volatile. */
3103 if (is_gimple_assign (stmt))
3104 {
3105 tree ctor = build_constructor (TREE_TYPE (dest), NULL);
3106 gimple_assign_set_rhs_from_tree (gsip, ctor);
3107 update_stmt (stmt);
3108 }
3109 else /* If stmt is memcpy, transform it into memset. */
3110 {
3111 gcall *call = as_a <gcall *> (stmt);
3112 tree fndecl = builtin_decl_implicit (BUILT_IN_MEMSET);
3113 gimple_call_set_fndecl (call, fndecl);
3114 gimple_call_set_fntype (call, TREE_TYPE (fndecl));
3115 gimple_call_set_arg (call, 1, val);
3116 update_stmt (stmt);
3117 }
3118
3119 if (dump_file && (dump_flags & TDF_DETAILS))
3120 {
3121 fprintf (dump_file, "into\n ");
3122 print_gimple_stmt (dump_file, stmt, 0, dump_flags);
3123 }
3124}
3125
3126/* A simple pass that attempts to fold all builtin functions. This pass
3127 is run after we've propagated as many constants as we can. */
3128
3129namespace {
3130
3131const pass_data pass_data_fold_builtins =
3132{
3133 GIMPLE_PASS, /* type */
3134 "fab", /* name */
3135 OPTGROUP_NONE, /* optinfo_flags */
3136 TV_NONE, /* tv_id */
3137 ( PROP_cfg | PROP_ssa ), /* properties_required */
3138 0, /* properties_provided */
3139 0, /* properties_destroyed */
3140 0, /* todo_flags_start */
3141 TODO_update_ssa, /* todo_flags_finish */
3142};
3143
3144class pass_fold_builtins : public gimple_opt_pass
3145{
3146public:
3147 pass_fold_builtins (gcc::context *ctxt)
3148 : gimple_opt_pass (pass_data_fold_builtins, ctxt)
3149 {}
3150
3151 /* opt_pass methods: */
3152 opt_pass * clone () { return new pass_fold_builtins (m_ctxt); }
3153 virtual unsigned int execute (function *);
3154
3155}; // class pass_fold_builtins
3156
3157unsigned int
3158pass_fold_builtins::execute (function *fun)
3159{
3160 bool cfg_changed = false;
3161 basic_block bb;
3162 unsigned int todoflags = 0;
3163
3164 FOR_EACH_BB_FN (bb, fun)
3165 {
3166 gimple_stmt_iterator i;
3167 for (i = gsi_start_bb (bb); !gsi_end_p (i); )
3168 {
3169 gimple *stmt, *old_stmt;
3170 tree callee;
3171 enum built_in_function fcode;
3172
3173 stmt = gsi_stmt (i);
3174
3175 if (gimple_code (stmt) != GIMPLE_CALL)
3176 {
3177 /* Remove all *ssaname_N ={v} {CLOBBER}; stmts,
3178 after the last GIMPLE DSE they aren't needed and might
3179 unnecessarily keep the SSA_NAMEs live. */
3180 if (gimple_clobber_p (stmt))
3181 {
3182 tree lhs = gimple_assign_lhs (stmt);
3183 if (TREE_CODE (lhs) == MEM_REF
3184 && TREE_CODE (TREE_OPERAND (lhs, 0)) == SSA_NAME)
3185 {
3186 unlink_stmt_vdef (stmt);
3187 gsi_remove (&i, true);
3188 release_defs (stmt);
3189 continue;
3190 }
3191 }
3192 else if (gimple_assign_load_p (stmt) && gimple_store_p (stmt))
3193 optimize_memcpy (&i, gimple_assign_lhs (stmt),
3194 gimple_assign_rhs1 (stmt), NULL_TREE);
3195 gsi_next (&i);
3196 continue;
3197 }
3198
3199 callee = gimple_call_fndecl (stmt);
3200 if (!callee || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL)
3201 {
3202 gsi_next (&i);
3203 continue;
3204 }
3205
3206 fcode = DECL_FUNCTION_CODE (callee);
3207 if (fold_stmt (&i))
3208 ;
3209 else
3210 {
3211 tree result = NULL_TREE;
3212 switch (DECL_FUNCTION_CODE (callee))
3213 {
3214 case BUILT_IN_CONSTANT_P:
3215 /* Resolve __builtin_constant_p. If it hasn't been
3216 folded to integer_one_node by now, it's fairly
3217 certain that the value simply isn't constant. */
3218 result = integer_zero_node;
3219 break;
3220
3221 case BUILT_IN_ASSUME_ALIGNED:
3222 /* Remove __builtin_assume_aligned. */
3223 result = gimple_call_arg (stmt, 0);
3224 break;
3225
3226 case BUILT_IN_STACK_RESTORE:
3227 result = optimize_stack_restore (i);
3228 if (result)
3229 break;
3230 gsi_next (&i);
3231 continue;
3232
3233 case BUILT_IN_UNREACHABLE:
3234 if (optimize_unreachable (i))
3235 cfg_changed = true;
3236 break;
3237
3238 case BUILT_IN_ATOMIC_FETCH_OR_1:
3239 case BUILT_IN_ATOMIC_FETCH_OR_2:
3240 case BUILT_IN_ATOMIC_FETCH_OR_4:
3241 case BUILT_IN_ATOMIC_FETCH_OR_8:
3242 case BUILT_IN_ATOMIC_FETCH_OR_16:
3243 optimize_atomic_bit_test_and (&i,
3244 IFN_ATOMIC_BIT_TEST_AND_SET,
3245 true, false);
3246 break;
3247 case BUILT_IN_SYNC_FETCH_AND_OR_1:
3248 case BUILT_IN_SYNC_FETCH_AND_OR_2:
3249 case BUILT_IN_SYNC_FETCH_AND_OR_4:
3250 case BUILT_IN_SYNC_FETCH_AND_OR_8:
3251 case BUILT_IN_SYNC_FETCH_AND_OR_16:
3252 optimize_atomic_bit_test_and (&i,
3253 IFN_ATOMIC_BIT_TEST_AND_SET,
3254 false, false);
3255 break;
3256
3257 case BUILT_IN_ATOMIC_FETCH_XOR_1:
3258 case BUILT_IN_ATOMIC_FETCH_XOR_2:
3259 case BUILT_IN_ATOMIC_FETCH_XOR_4:
3260 case BUILT_IN_ATOMIC_FETCH_XOR_8:
3261 case BUILT_IN_ATOMIC_FETCH_XOR_16:
3262 optimize_atomic_bit_test_and
3263 (&i, IFN_ATOMIC_BIT_TEST_AND_COMPLEMENT, true, false);
3264 break;
3265 case BUILT_IN_SYNC_FETCH_AND_XOR_1:
3266 case BUILT_IN_SYNC_FETCH_AND_XOR_2:
3267 case BUILT_IN_SYNC_FETCH_AND_XOR_4:
3268 case BUILT_IN_SYNC_FETCH_AND_XOR_8:
3269 case BUILT_IN_SYNC_FETCH_AND_XOR_16:
3270 optimize_atomic_bit_test_and
3271 (&i, IFN_ATOMIC_BIT_TEST_AND_COMPLEMENT, false, false);
3272 break;
3273
3274 case BUILT_IN_ATOMIC_XOR_FETCH_1:
3275 case BUILT_IN_ATOMIC_XOR_FETCH_2:
3276 case BUILT_IN_ATOMIC_XOR_FETCH_4:
3277 case BUILT_IN_ATOMIC_XOR_FETCH_8:
3278 case BUILT_IN_ATOMIC_XOR_FETCH_16:
3279 optimize_atomic_bit_test_and
3280 (&i, IFN_ATOMIC_BIT_TEST_AND_COMPLEMENT, true, true);
3281 break;
3282 case BUILT_IN_SYNC_XOR_AND_FETCH_1:
3283 case BUILT_IN_SYNC_XOR_AND_FETCH_2:
3284 case BUILT_IN_SYNC_XOR_AND_FETCH_4:
3285 case BUILT_IN_SYNC_XOR_AND_FETCH_8:
3286 case BUILT_IN_SYNC_XOR_AND_FETCH_16:
3287 optimize_atomic_bit_test_and
3288 (&i, IFN_ATOMIC_BIT_TEST_AND_COMPLEMENT, false, true);
3289 break;
3290
3291 case BUILT_IN_ATOMIC_FETCH_AND_1:
3292 case BUILT_IN_ATOMIC_FETCH_AND_2:
3293 case BUILT_IN_ATOMIC_FETCH_AND_4:
3294 case BUILT_IN_ATOMIC_FETCH_AND_8:
3295 case BUILT_IN_ATOMIC_FETCH_AND_16:
3296 optimize_atomic_bit_test_and (&i,
3297 IFN_ATOMIC_BIT_TEST_AND_RESET,
3298 true, false);
3299 break;
3300 case BUILT_IN_SYNC_FETCH_AND_AND_1:
3301 case BUILT_IN_SYNC_FETCH_AND_AND_2:
3302 case BUILT_IN_SYNC_FETCH_AND_AND_4:
3303 case BUILT_IN_SYNC_FETCH_AND_AND_8:
3304 case BUILT_IN_SYNC_FETCH_AND_AND_16:
3305 optimize_atomic_bit_test_and (&i,
3306 IFN_ATOMIC_BIT_TEST_AND_RESET,
3307 false, false);
3308 break;
3309
3310 case BUILT_IN_MEMCPY:
3311 if (gimple_call_builtin_p (stmt, BUILT_IN_NORMAL)
3312 && TREE_CODE (gimple_call_arg (stmt, 0)) == ADDR_EXPR
3313 && TREE_CODE (gimple_call_arg (stmt, 1)) == ADDR_EXPR
3314 && TREE_CODE (gimple_call_arg (stmt, 2)) == INTEGER_CST)
3315 {
3316 tree dest = TREE_OPERAND (gimple_call_arg (stmt, 0), 0);
3317 tree src = TREE_OPERAND (gimple_call_arg (stmt, 1), 0);
3318 tree len = gimple_call_arg (stmt, 2);
3319 optimize_memcpy (&i, dest, src, len);
3320 }
3321 break;
3322
3323 case BUILT_IN_VA_START:
3324 case BUILT_IN_VA_END:
3325 case BUILT_IN_VA_COPY:
3326 /* These shouldn't be folded before pass_stdarg. */
3327 result = optimize_stdarg_builtin (stmt);
3328 break;
3329
3330 default:;
3331 }
3332
3333 if (!result)
3334 {
3335 gsi_next (&i);
3336 continue;
3337 }
3338
3339 if (!update_call_from_tree (&i, result))
3340 gimplify_and_update_call_from_tree (&i, result);
3341 }
3342
3343 todoflags |= TODO_update_address_taken;
3344
3345 if (dump_file && (dump_flags & TDF_DETAILS))
3346 {
3347 fprintf (dump_file, "Simplified\n ");
3348 print_gimple_stmt (dump_file, stmt, 0, dump_flags);
3349 }
3350
3351 old_stmt = stmt;
3352 stmt = gsi_stmt (i);
3353 update_stmt (stmt);
3354
3355 if (maybe_clean_or_replace_eh_stmt (old_stmt, stmt)
3356 && gimple_purge_dead_eh_edges (bb))
3357 cfg_changed = true;
3358
3359 if (dump_file && (dump_flags & TDF_DETAILS))
3360 {
3361 fprintf (dump_file, "to\n ");
3362 print_gimple_stmt (dump_file, stmt, 0, dump_flags);
3363 fprintf (dump_file, "\n");
3364 }
3365
3366 /* Retry the same statement if it changed into another
3367 builtin, there might be new opportunities now. */
3368 if (gimple_code (stmt) != GIMPLE_CALL)
3369 {
3370 gsi_next (&i);
3371 continue;
3372 }
3373 callee = gimple_call_fndecl (stmt);
3374 if (!callee
3375 || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL
3376 || DECL_FUNCTION_CODE (callee) == fcode)
3377 gsi_next (&i);
3378 }
3379 }
3380
3381 /* Delete unreachable blocks. */
3382 if (cfg_changed)
3383 todoflags |= TODO_cleanup_cfg;
3384
3385 return todoflags;
3386}
3387
3388} // anon namespace
3389
3390gimple_opt_pass *
3391make_pass_fold_builtins (gcc::context *ctxt)
3392{
3393 return new pass_fold_builtins (ctxt);
3394}
3395
3396/* A simple pass that emits some warnings post IPA. */
3397
3398namespace {
3399
3400const pass_data pass_data_post_ipa_warn =
3401{
3402 GIMPLE_PASS, /* type */
3403 "post_ipa_warn", /* name */
3404 OPTGROUP_NONE, /* optinfo_flags */
3405 TV_NONE, /* tv_id */
3406 ( PROP_cfg | PROP_ssa ), /* properties_required */
3407 0, /* properties_provided */
3408 0, /* properties_destroyed */
3409 0, /* todo_flags_start */
3410 0, /* todo_flags_finish */
3411};
3412
3413class pass_post_ipa_warn : public gimple_opt_pass
3414{
3415public:
3416 pass_post_ipa_warn (gcc::context *ctxt)
3417 : gimple_opt_pass (pass_data_post_ipa_warn, ctxt)
3418 {}
3419
3420 /* opt_pass methods: */
3421 opt_pass * clone () { return new pass_post_ipa_warn (m_ctxt); }
3422 virtual bool gate (function *) { return warn_nonnull != 0; }
3423 virtual unsigned int execute (function *);
3424
3425}; // class pass_fold_builtins
3426
3427unsigned int
3428pass_post_ipa_warn::execute (function *fun)
3429{
3430 basic_block bb;
3431
3432 FOR_EACH_BB_FN (bb, fun)
3433 {
3434 gimple_stmt_iterator gsi;
3435 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
3436 {
3437 gimple *stmt = gsi_stmt (gsi);
3438 if (!is_gimple_call (stmt) || gimple_no_warning_p (stmt))
3439 continue;
3440
3441 if (warn_nonnull)
3442 {
3443 bitmap nonnullargs
3444 = get_nonnull_args (gimple_call_fntype (stmt));
3445 if (nonnullargs)
3446 {
3447 for (unsigned i = 0; i < gimple_call_num_args (stmt); i++)
3448 {
3449 tree arg = gimple_call_arg (stmt, i);
3450 if (TREE_CODE (TREE_TYPE (arg)) != POINTER_TYPE)
3451 continue;
3452 if (!integer_zerop (arg))
3453 continue;
3454 if (!bitmap_empty_p (nonnullargs)
3455 && !bitmap_bit_p (nonnullargs, i))
3456 continue;
3457
3458 location_t loc = gimple_location (stmt);
3459 if (warning_at (loc, OPT_Wnonnull,
3460 "argument %u null where non-null "
3461 "expected", i + 1))
3462 {
3463 tree fndecl = gimple_call_fndecl (stmt);
3464 if (fndecl && DECL_IS_BUILTIN (fndecl))
3465 inform (loc, "in a call to built-in function %qD",
3466 fndecl);
3467 else if (fndecl)
3468 inform (DECL_SOURCE_LOCATION (fndecl),
3469 "in a call to function %qD declared here",
3470 fndecl);
3471
3472 }
3473 }
3474 BITMAP_FREE (nonnullargs);
3475 }
3476 }
3477 }
3478 }
3479 return 0;
3480}
3481
3482} // anon namespace
3483
3484gimple_opt_pass *
3485make_pass_post_ipa_warn (gcc::context *ctxt)
3486{
3487 return new pass_post_ipa_warn (ctxt);
3488}
3489