PR target/84064
[official-gcc.git] / gcc / fold-const.c
blobc86c3f9b44d5f58c181acdd3c04976e8301c2a05
1 /* Fold a constant sub-tree into a single node for C-compiler
2 Copyright (C) 1987-2018 Free Software Foundation, Inc.
4 This file is part of GCC.
6 GCC is free software; you can redistribute it and/or modify it under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 3, or (at your option) any later
9 version.
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 for more details.
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3. If not see
18 <http://www.gnu.org/licenses/>. */
20 /*@@ This file should be rewritten to use an arbitrary precision
21 @@ representation for "struct tree_int_cst" and "struct tree_real_cst".
22 @@ Perhaps the routines could also be used for bc/dc, and made a lib.
23 @@ The routines that translate from the ap rep should
24 @@ warn if precision et. al. is lost.
25 @@ This would also make life easier when this technology is used
26 @@ for cross-compilers. */
28 /* The entry points in this file are fold, size_int_wide and size_binop.
30 fold takes a tree as argument and returns a simplified tree.
32 size_binop takes a tree code for an arithmetic operation
33 and two operands that are trees, and produces a tree for the
34 result, assuming the type comes from `sizetype'.
36 size_int takes an integer value, and creates a tree constant
37 with type from `sizetype'.
39 Note: Since the folders get called on non-gimple code as well as
40 gimple code, we need to handle GIMPLE tuples as well as their
41 corresponding tree equivalents. */
43 #include "config.h"
44 #include "system.h"
45 #include "coretypes.h"
46 #include "backend.h"
47 #include "target.h"
48 #include "rtl.h"
49 #include "tree.h"
50 #include "gimple.h"
51 #include "predict.h"
52 #include "memmodel.h"
53 #include "tm_p.h"
54 #include "tree-ssa-operands.h"
55 #include "optabs-query.h"
56 #include "cgraph.h"
57 #include "diagnostic-core.h"
58 #include "flags.h"
59 #include "alias.h"
60 #include "fold-const.h"
61 #include "fold-const-call.h"
62 #include "stor-layout.h"
63 #include "calls.h"
64 #include "tree-iterator.h"
65 #include "expr.h"
66 #include "intl.h"
67 #include "langhooks.h"
68 #include "tree-eh.h"
69 #include "gimplify.h"
70 #include "tree-dfa.h"
71 #include "builtins.h"
72 #include "generic-match.h"
73 #include "gimple-fold.h"
74 #include "params.h"
75 #include "tree-into-ssa.h"
76 #include "md5.h"
77 #include "case-cfn-macros.h"
78 #include "stringpool.h"
79 #include "tree-vrp.h"
80 #include "tree-ssanames.h"
81 #include "selftest.h"
82 #include "stringpool.h"
83 #include "attribs.h"
84 #include "tree-vector-builder.h"
85 #include "vec-perm-indices.h"
87 /* Nonzero if we are folding constants inside an initializer; zero
88 otherwise. */
89 int folding_initializer = 0;
91 /* The following constants represent a bit based encoding of GCC's
92 comparison operators. This encoding simplifies transformations
93 on relational comparison operators, such as AND and OR. */
94 enum comparison_code {
95 COMPCODE_FALSE = 0,
96 COMPCODE_LT = 1,
97 COMPCODE_EQ = 2,
98 COMPCODE_LE = 3,
99 COMPCODE_GT = 4,
100 COMPCODE_LTGT = 5,
101 COMPCODE_GE = 6,
102 COMPCODE_ORD = 7,
103 COMPCODE_UNORD = 8,
104 COMPCODE_UNLT = 9,
105 COMPCODE_UNEQ = 10,
106 COMPCODE_UNLE = 11,
107 COMPCODE_UNGT = 12,
108 COMPCODE_NE = 13,
109 COMPCODE_UNGE = 14,
110 COMPCODE_TRUE = 15
113 static bool negate_expr_p (tree);
114 static tree negate_expr (tree);
115 static tree associate_trees (location_t, tree, tree, enum tree_code, tree);
116 static enum comparison_code comparison_to_compcode (enum tree_code);
117 static enum tree_code compcode_to_comparison (enum comparison_code);
118 static int twoval_comparison_p (tree, tree *, tree *, int *);
119 static tree eval_subst (location_t, tree, tree, tree, tree, tree);
120 static tree optimize_bit_field_compare (location_t, enum tree_code,
121 tree, tree, tree);
122 static int simple_operand_p (const_tree);
123 static bool simple_operand_p_2 (tree);
124 static tree range_binop (enum tree_code, tree, tree, int, tree, int);
125 static tree range_predecessor (tree);
126 static tree range_successor (tree);
127 static tree fold_range_test (location_t, enum tree_code, tree, tree, tree);
128 static tree fold_cond_expr_with_comparison (location_t, tree, tree, tree, tree);
129 static tree unextend (tree, int, int, tree);
130 static tree extract_muldiv (tree, tree, enum tree_code, tree, bool *);
131 static tree extract_muldiv_1 (tree, tree, enum tree_code, tree, bool *);
132 static tree fold_binary_op_with_conditional_arg (location_t,
133 enum tree_code, tree,
134 tree, tree,
135 tree, tree, int);
136 static tree fold_negate_const (tree, tree);
137 static tree fold_not_const (const_tree, tree);
138 static tree fold_relational_const (enum tree_code, tree, tree, tree);
139 static tree fold_convert_const (enum tree_code, tree, tree);
140 static tree fold_view_convert_expr (tree, tree);
141 static tree fold_negate_expr (location_t, tree);
144 /* Return EXPR_LOCATION of T if it is not UNKNOWN_LOCATION.
145 Otherwise, return LOC. */
147 static location_t
148 expr_location_or (tree t, location_t loc)
150 location_t tloc = EXPR_LOCATION (t);
151 return tloc == UNKNOWN_LOCATION ? loc : tloc;
154 /* Similar to protected_set_expr_location, but never modify x in place,
155 if location can and needs to be set, unshare it. */
157 static inline tree
158 protected_set_expr_location_unshare (tree x, location_t loc)
160 if (CAN_HAVE_LOCATION_P (x)
161 && EXPR_LOCATION (x) != loc
162 && !(TREE_CODE (x) == SAVE_EXPR
163 || TREE_CODE (x) == TARGET_EXPR
164 || TREE_CODE (x) == BIND_EXPR))
166 x = copy_node (x);
167 SET_EXPR_LOCATION (x, loc);
169 return x;
172 /* If ARG2 divides ARG1 with zero remainder, carries out the exact
173 division and returns the quotient. Otherwise returns
174 NULL_TREE. */
176 tree
177 div_if_zero_remainder (const_tree arg1, const_tree arg2)
179 widest_int quo;
181 if (wi::multiple_of_p (wi::to_widest (arg1), wi::to_widest (arg2),
182 SIGNED, &quo))
183 return wide_int_to_tree (TREE_TYPE (arg1), quo);
185 return NULL_TREE;
188 /* This is nonzero if we should defer warnings about undefined
189 overflow. This facility exists because these warnings are a
190 special case. The code to estimate loop iterations does not want
191 to issue any warnings, since it works with expressions which do not
192 occur in user code. Various bits of cleanup code call fold(), but
193 only use the result if it has certain characteristics (e.g., is a
194 constant); that code only wants to issue a warning if the result is
195 used. */
197 static int fold_deferring_overflow_warnings;
199 /* If a warning about undefined overflow is deferred, this is the
200 warning. Note that this may cause us to turn two warnings into
201 one, but that is fine since it is sufficient to only give one
202 warning per expression. */
204 static const char* fold_deferred_overflow_warning;
206 /* If a warning about undefined overflow is deferred, this is the
207 level at which the warning should be emitted. */
209 static enum warn_strict_overflow_code fold_deferred_overflow_code;
211 /* Start deferring overflow warnings. We could use a stack here to
212 permit nested calls, but at present it is not necessary. */
214 void
215 fold_defer_overflow_warnings (void)
217 ++fold_deferring_overflow_warnings;
220 /* Stop deferring overflow warnings. If there is a pending warning,
221 and ISSUE is true, then issue the warning if appropriate. STMT is
222 the statement with which the warning should be associated (used for
223 location information); STMT may be NULL. CODE is the level of the
224 warning--a warn_strict_overflow_code value. This function will use
225 the smaller of CODE and the deferred code when deciding whether to
226 issue the warning. CODE may be zero to mean to always use the
227 deferred code. */
229 void
230 fold_undefer_overflow_warnings (bool issue, const gimple *stmt, int code)
232 const char *warnmsg;
233 location_t locus;
235 gcc_assert (fold_deferring_overflow_warnings > 0);
236 --fold_deferring_overflow_warnings;
237 if (fold_deferring_overflow_warnings > 0)
239 if (fold_deferred_overflow_warning != NULL
240 && code != 0
241 && code < (int) fold_deferred_overflow_code)
242 fold_deferred_overflow_code = (enum warn_strict_overflow_code) code;
243 return;
246 warnmsg = fold_deferred_overflow_warning;
247 fold_deferred_overflow_warning = NULL;
249 if (!issue || warnmsg == NULL)
250 return;
252 if (gimple_no_warning_p (stmt))
253 return;
255 /* Use the smallest code level when deciding to issue the
256 warning. */
257 if (code == 0 || code > (int) fold_deferred_overflow_code)
258 code = fold_deferred_overflow_code;
260 if (!issue_strict_overflow_warning (code))
261 return;
263 if (stmt == NULL)
264 locus = input_location;
265 else
266 locus = gimple_location (stmt);
267 warning_at (locus, OPT_Wstrict_overflow, "%s", warnmsg);
270 /* Stop deferring overflow warnings, ignoring any deferred
271 warnings. */
273 void
274 fold_undefer_and_ignore_overflow_warnings (void)
276 fold_undefer_overflow_warnings (false, NULL, 0);
279 /* Whether we are deferring overflow warnings. */
281 bool
282 fold_deferring_overflow_warnings_p (void)
284 return fold_deferring_overflow_warnings > 0;
287 /* This is called when we fold something based on the fact that signed
288 overflow is undefined. */
290 void
291 fold_overflow_warning (const char* gmsgid, enum warn_strict_overflow_code wc)
293 if (fold_deferring_overflow_warnings > 0)
295 if (fold_deferred_overflow_warning == NULL
296 || wc < fold_deferred_overflow_code)
298 fold_deferred_overflow_warning = gmsgid;
299 fold_deferred_overflow_code = wc;
302 else if (issue_strict_overflow_warning (wc))
303 warning (OPT_Wstrict_overflow, gmsgid);
306 /* Return true if the built-in mathematical function specified by CODE
307 is odd, i.e. -f(x) == f(-x). */
309 bool
310 negate_mathfn_p (combined_fn fn)
312 switch (fn)
314 CASE_CFN_ASIN:
315 CASE_CFN_ASINH:
316 CASE_CFN_ATAN:
317 CASE_CFN_ATANH:
318 CASE_CFN_CASIN:
319 CASE_CFN_CASINH:
320 CASE_CFN_CATAN:
321 CASE_CFN_CATANH:
322 CASE_CFN_CBRT:
323 CASE_CFN_CPROJ:
324 CASE_CFN_CSIN:
325 CASE_CFN_CSINH:
326 CASE_CFN_CTAN:
327 CASE_CFN_CTANH:
328 CASE_CFN_ERF:
329 CASE_CFN_LLROUND:
330 CASE_CFN_LROUND:
331 CASE_CFN_ROUND:
332 CASE_CFN_SIN:
333 CASE_CFN_SINH:
334 CASE_CFN_TAN:
335 CASE_CFN_TANH:
336 CASE_CFN_TRUNC:
337 return true;
339 CASE_CFN_LLRINT:
340 CASE_CFN_LRINT:
341 CASE_CFN_NEARBYINT:
342 CASE_CFN_RINT:
343 return !flag_rounding_math;
345 default:
346 break;
348 return false;
351 /* Check whether we may negate an integer constant T without causing
352 overflow. */
354 bool
355 may_negate_without_overflow_p (const_tree t)
357 tree type;
359 gcc_assert (TREE_CODE (t) == INTEGER_CST);
361 type = TREE_TYPE (t);
362 if (TYPE_UNSIGNED (type))
363 return false;
365 return !wi::only_sign_bit_p (wi::to_wide (t));
368 /* Determine whether an expression T can be cheaply negated using
369 the function negate_expr without introducing undefined overflow. */
371 static bool
372 negate_expr_p (tree t)
374 tree type;
376 if (t == 0)
377 return false;
379 type = TREE_TYPE (t);
381 STRIP_SIGN_NOPS (t);
382 switch (TREE_CODE (t))
384 case INTEGER_CST:
385 if (INTEGRAL_TYPE_P (type) && TYPE_UNSIGNED (type))
386 return true;
388 /* Check that -CST will not overflow type. */
389 return may_negate_without_overflow_p (t);
390 case BIT_NOT_EXPR:
391 return (INTEGRAL_TYPE_P (type)
392 && TYPE_OVERFLOW_WRAPS (type));
394 case FIXED_CST:
395 return true;
397 case NEGATE_EXPR:
398 return !TYPE_OVERFLOW_SANITIZED (type);
400 case REAL_CST:
401 /* We want to canonicalize to positive real constants. Pretend
402 that only negative ones can be easily negated. */
403 return REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
405 case COMPLEX_CST:
406 return negate_expr_p (TREE_REALPART (t))
407 && negate_expr_p (TREE_IMAGPART (t));
409 case VECTOR_CST:
411 if (FLOAT_TYPE_P (TREE_TYPE (type)) || TYPE_OVERFLOW_WRAPS (type))
412 return true;
414 /* Steps don't prevent negation. */
415 unsigned int count = vector_cst_encoded_nelts (t);
416 for (unsigned int i = 0; i < count; ++i)
417 if (!negate_expr_p (VECTOR_CST_ENCODED_ELT (t, i)))
418 return false;
420 return true;
423 case COMPLEX_EXPR:
424 return negate_expr_p (TREE_OPERAND (t, 0))
425 && negate_expr_p (TREE_OPERAND (t, 1));
427 case CONJ_EXPR:
428 return negate_expr_p (TREE_OPERAND (t, 0));
430 case PLUS_EXPR:
431 if (HONOR_SIGN_DEPENDENT_ROUNDING (element_mode (type))
432 || HONOR_SIGNED_ZEROS (element_mode (type))
433 || (ANY_INTEGRAL_TYPE_P (type)
434 && ! TYPE_OVERFLOW_WRAPS (type)))
435 return false;
436 /* -(A + B) -> (-B) - A. */
437 if (negate_expr_p (TREE_OPERAND (t, 1)))
438 return true;
439 /* -(A + B) -> (-A) - B. */
440 return negate_expr_p (TREE_OPERAND (t, 0));
442 case MINUS_EXPR:
443 /* We can't turn -(A-B) into B-A when we honor signed zeros. */
444 return !HONOR_SIGN_DEPENDENT_ROUNDING (element_mode (type))
445 && !HONOR_SIGNED_ZEROS (element_mode (type))
446 && (! ANY_INTEGRAL_TYPE_P (type)
447 || TYPE_OVERFLOW_WRAPS (type));
449 case MULT_EXPR:
450 if (TYPE_UNSIGNED (type))
451 break;
452 /* INT_MIN/n * n doesn't overflow while negating one operand it does
453 if n is a (negative) power of two. */
454 if (INTEGRAL_TYPE_P (TREE_TYPE (t))
455 && ! TYPE_OVERFLOW_WRAPS (TREE_TYPE (t))
456 && ! ((TREE_CODE (TREE_OPERAND (t, 0)) == INTEGER_CST
457 && (wi::popcount
458 (wi::abs (wi::to_wide (TREE_OPERAND (t, 0))))) != 1)
459 || (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
460 && (wi::popcount
461 (wi::abs (wi::to_wide (TREE_OPERAND (t, 1))))) != 1)))
462 break;
464 /* Fall through. */
466 case RDIV_EXPR:
467 if (! HONOR_SIGN_DEPENDENT_ROUNDING (element_mode (TREE_TYPE (t))))
468 return negate_expr_p (TREE_OPERAND (t, 1))
469 || negate_expr_p (TREE_OPERAND (t, 0));
470 break;
472 case TRUNC_DIV_EXPR:
473 case ROUND_DIV_EXPR:
474 case EXACT_DIV_EXPR:
475 if (TYPE_UNSIGNED (type))
476 break;
477 if (negate_expr_p (TREE_OPERAND (t, 0)))
478 return true;
479 /* In general we can't negate B in A / B, because if A is INT_MIN and
480 B is 1, we may turn this into INT_MIN / -1 which is undefined
481 and actually traps on some architectures. */
482 if (! INTEGRAL_TYPE_P (TREE_TYPE (t))
483 || TYPE_OVERFLOW_WRAPS (TREE_TYPE (t))
484 || (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
485 && ! integer_onep (TREE_OPERAND (t, 1))))
486 return negate_expr_p (TREE_OPERAND (t, 1));
487 break;
489 case NOP_EXPR:
490 /* Negate -((double)float) as (double)(-float). */
491 if (TREE_CODE (type) == REAL_TYPE)
493 tree tem = strip_float_extensions (t);
494 if (tem != t)
495 return negate_expr_p (tem);
497 break;
499 case CALL_EXPR:
500 /* Negate -f(x) as f(-x). */
501 if (negate_mathfn_p (get_call_combined_fn (t)))
502 return negate_expr_p (CALL_EXPR_ARG (t, 0));
503 break;
505 case RSHIFT_EXPR:
506 /* Optimize -((int)x >> 31) into (unsigned)x >> 31 for int. */
507 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
509 tree op1 = TREE_OPERAND (t, 1);
510 if (wi::to_wide (op1) == TYPE_PRECISION (type) - 1)
511 return true;
513 break;
515 default:
516 break;
518 return false;
521 /* Given T, an expression, return a folded tree for -T or NULL_TREE, if no
522 simplification is possible.
523 If negate_expr_p would return true for T, NULL_TREE will never be
524 returned. */
526 static tree
527 fold_negate_expr_1 (location_t loc, tree t)
529 tree type = TREE_TYPE (t);
530 tree tem;
532 switch (TREE_CODE (t))
534 /* Convert - (~A) to A + 1. */
535 case BIT_NOT_EXPR:
536 if (INTEGRAL_TYPE_P (type))
537 return fold_build2_loc (loc, PLUS_EXPR, type, TREE_OPERAND (t, 0),
538 build_one_cst (type));
539 break;
541 case INTEGER_CST:
542 tem = fold_negate_const (t, type);
543 if (TREE_OVERFLOW (tem) == TREE_OVERFLOW (t)
544 || (ANY_INTEGRAL_TYPE_P (type)
545 && !TYPE_OVERFLOW_TRAPS (type)
546 && TYPE_OVERFLOW_WRAPS (type))
547 || (flag_sanitize & SANITIZE_SI_OVERFLOW) == 0)
548 return tem;
549 break;
551 case POLY_INT_CST:
552 case REAL_CST:
553 case FIXED_CST:
554 tem = fold_negate_const (t, type);
555 return tem;
557 case COMPLEX_CST:
559 tree rpart = fold_negate_expr (loc, TREE_REALPART (t));
560 tree ipart = fold_negate_expr (loc, TREE_IMAGPART (t));
561 if (rpart && ipart)
562 return build_complex (type, rpart, ipart);
564 break;
566 case VECTOR_CST:
568 tree_vector_builder elts;
569 elts.new_unary_operation (type, t, true);
570 unsigned int count = elts.encoded_nelts ();
571 for (unsigned int i = 0; i < count; ++i)
573 tree elt = fold_negate_expr (loc, VECTOR_CST_ELT (t, i));
574 if (elt == NULL_TREE)
575 return NULL_TREE;
576 elts.quick_push (elt);
579 return elts.build ();
582 case COMPLEX_EXPR:
583 if (negate_expr_p (t))
584 return fold_build2_loc (loc, COMPLEX_EXPR, type,
585 fold_negate_expr (loc, TREE_OPERAND (t, 0)),
586 fold_negate_expr (loc, TREE_OPERAND (t, 1)));
587 break;
589 case CONJ_EXPR:
590 if (negate_expr_p (t))
591 return fold_build1_loc (loc, CONJ_EXPR, type,
592 fold_negate_expr (loc, TREE_OPERAND (t, 0)));
593 break;
595 case NEGATE_EXPR:
596 if (!TYPE_OVERFLOW_SANITIZED (type))
597 return TREE_OPERAND (t, 0);
598 break;
600 case PLUS_EXPR:
601 if (!HONOR_SIGN_DEPENDENT_ROUNDING (element_mode (type))
602 && !HONOR_SIGNED_ZEROS (element_mode (type)))
604 /* -(A + B) -> (-B) - A. */
605 if (negate_expr_p (TREE_OPERAND (t, 1)))
607 tem = negate_expr (TREE_OPERAND (t, 1));
608 return fold_build2_loc (loc, MINUS_EXPR, type,
609 tem, TREE_OPERAND (t, 0));
612 /* -(A + B) -> (-A) - B. */
613 if (negate_expr_p (TREE_OPERAND (t, 0)))
615 tem = negate_expr (TREE_OPERAND (t, 0));
616 return fold_build2_loc (loc, MINUS_EXPR, type,
617 tem, TREE_OPERAND (t, 1));
620 break;
622 case MINUS_EXPR:
623 /* - (A - B) -> B - A */
624 if (!HONOR_SIGN_DEPENDENT_ROUNDING (element_mode (type))
625 && !HONOR_SIGNED_ZEROS (element_mode (type)))
626 return fold_build2_loc (loc, MINUS_EXPR, type,
627 TREE_OPERAND (t, 1), TREE_OPERAND (t, 0));
628 break;
630 case MULT_EXPR:
631 if (TYPE_UNSIGNED (type))
632 break;
634 /* Fall through. */
636 case RDIV_EXPR:
637 if (! HONOR_SIGN_DEPENDENT_ROUNDING (element_mode (type)))
639 tem = TREE_OPERAND (t, 1);
640 if (negate_expr_p (tem))
641 return fold_build2_loc (loc, TREE_CODE (t), type,
642 TREE_OPERAND (t, 0), negate_expr (tem));
643 tem = TREE_OPERAND (t, 0);
644 if (negate_expr_p (tem))
645 return fold_build2_loc (loc, TREE_CODE (t), type,
646 negate_expr (tem), TREE_OPERAND (t, 1));
648 break;
650 case TRUNC_DIV_EXPR:
651 case ROUND_DIV_EXPR:
652 case EXACT_DIV_EXPR:
653 if (TYPE_UNSIGNED (type))
654 break;
655 if (negate_expr_p (TREE_OPERAND (t, 0)))
656 return fold_build2_loc (loc, TREE_CODE (t), type,
657 negate_expr (TREE_OPERAND (t, 0)),
658 TREE_OPERAND (t, 1));
659 /* In general we can't negate B in A / B, because if A is INT_MIN and
660 B is 1, we may turn this into INT_MIN / -1 which is undefined
661 and actually traps on some architectures. */
662 if ((! INTEGRAL_TYPE_P (TREE_TYPE (t))
663 || TYPE_OVERFLOW_WRAPS (TREE_TYPE (t))
664 || (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
665 && ! integer_onep (TREE_OPERAND (t, 1))))
666 && negate_expr_p (TREE_OPERAND (t, 1)))
667 return fold_build2_loc (loc, TREE_CODE (t), type,
668 TREE_OPERAND (t, 0),
669 negate_expr (TREE_OPERAND (t, 1)));
670 break;
672 case NOP_EXPR:
673 /* Convert -((double)float) into (double)(-float). */
674 if (TREE_CODE (type) == REAL_TYPE)
676 tem = strip_float_extensions (t);
677 if (tem != t && negate_expr_p (tem))
678 return fold_convert_loc (loc, type, negate_expr (tem));
680 break;
682 case CALL_EXPR:
683 /* Negate -f(x) as f(-x). */
684 if (negate_mathfn_p (get_call_combined_fn (t))
685 && negate_expr_p (CALL_EXPR_ARG (t, 0)))
687 tree fndecl, arg;
689 fndecl = get_callee_fndecl (t);
690 arg = negate_expr (CALL_EXPR_ARG (t, 0));
691 return build_call_expr_loc (loc, fndecl, 1, arg);
693 break;
695 case RSHIFT_EXPR:
696 /* Optimize -((int)x >> 31) into (unsigned)x >> 31 for int. */
697 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
699 tree op1 = TREE_OPERAND (t, 1);
700 if (wi::to_wide (op1) == TYPE_PRECISION (type) - 1)
702 tree ntype = TYPE_UNSIGNED (type)
703 ? signed_type_for (type)
704 : unsigned_type_for (type);
705 tree temp = fold_convert_loc (loc, ntype, TREE_OPERAND (t, 0));
706 temp = fold_build2_loc (loc, RSHIFT_EXPR, ntype, temp, op1);
707 return fold_convert_loc (loc, type, temp);
710 break;
712 default:
713 break;
716 return NULL_TREE;
719 /* A wrapper for fold_negate_expr_1. */
721 static tree
722 fold_negate_expr (location_t loc, tree t)
724 tree type = TREE_TYPE (t);
725 STRIP_SIGN_NOPS (t);
726 tree tem = fold_negate_expr_1 (loc, t);
727 if (tem == NULL_TREE)
728 return NULL_TREE;
729 return fold_convert_loc (loc, type, tem);
732 /* Like fold_negate_expr, but return a NEGATE_EXPR tree, if T can not be
733 negated in a simpler way. Also allow for T to be NULL_TREE, in which case
734 return NULL_TREE. */
736 static tree
737 negate_expr (tree t)
739 tree type, tem;
740 location_t loc;
742 if (t == NULL_TREE)
743 return NULL_TREE;
745 loc = EXPR_LOCATION (t);
746 type = TREE_TYPE (t);
747 STRIP_SIGN_NOPS (t);
749 tem = fold_negate_expr (loc, t);
750 if (!tem)
751 tem = build1_loc (loc, NEGATE_EXPR, TREE_TYPE (t), t);
752 return fold_convert_loc (loc, type, tem);
755 /* Split a tree IN into a constant, literal and variable parts that could be
756 combined with CODE to make IN. "constant" means an expression with
757 TREE_CONSTANT but that isn't an actual constant. CODE must be a
758 commutative arithmetic operation. Store the constant part into *CONP,
759 the literal in *LITP and return the variable part. If a part isn't
760 present, set it to null. If the tree does not decompose in this way,
761 return the entire tree as the variable part and the other parts as null.
763 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
764 case, we negate an operand that was subtracted. Except if it is a
765 literal for which we use *MINUS_LITP instead.
767 If NEGATE_P is true, we are negating all of IN, again except a literal
768 for which we use *MINUS_LITP instead. If a variable part is of pointer
769 type, it is negated after converting to TYPE. This prevents us from
770 generating illegal MINUS pointer expression. LOC is the location of
771 the converted variable part.
773 If IN is itself a literal or constant, return it as appropriate.
775 Note that we do not guarantee that any of the three values will be the
776 same type as IN, but they will have the same signedness and mode. */
778 static tree
779 split_tree (tree in, tree type, enum tree_code code,
780 tree *minus_varp, tree *conp, tree *minus_conp,
781 tree *litp, tree *minus_litp, int negate_p)
783 tree var = 0;
784 *minus_varp = 0;
785 *conp = 0;
786 *minus_conp = 0;
787 *litp = 0;
788 *minus_litp = 0;
790 /* Strip any conversions that don't change the machine mode or signedness. */
791 STRIP_SIGN_NOPS (in);
793 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST
794 || TREE_CODE (in) == FIXED_CST)
795 *litp = in;
796 else if (TREE_CODE (in) == code
797 || ((! FLOAT_TYPE_P (TREE_TYPE (in)) || flag_associative_math)
798 && ! SAT_FIXED_POINT_TYPE_P (TREE_TYPE (in))
799 /* We can associate addition and subtraction together (even
800 though the C standard doesn't say so) for integers because
801 the value is not affected. For reals, the value might be
802 affected, so we can't. */
803 && ((code == PLUS_EXPR && TREE_CODE (in) == POINTER_PLUS_EXPR)
804 || (code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
805 || (code == MINUS_EXPR
806 && (TREE_CODE (in) == PLUS_EXPR
807 || TREE_CODE (in) == POINTER_PLUS_EXPR)))))
809 tree op0 = TREE_OPERAND (in, 0);
810 tree op1 = TREE_OPERAND (in, 1);
811 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
812 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
814 /* First see if either of the operands is a literal, then a constant. */
815 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST
816 || TREE_CODE (op0) == FIXED_CST)
817 *litp = op0, op0 = 0;
818 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST
819 || TREE_CODE (op1) == FIXED_CST)
820 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
822 if (op0 != 0 && TREE_CONSTANT (op0))
823 *conp = op0, op0 = 0;
824 else if (op1 != 0 && TREE_CONSTANT (op1))
825 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
827 /* If we haven't dealt with either operand, this is not a case we can
828 decompose. Otherwise, VAR is either of the ones remaining, if any. */
829 if (op0 != 0 && op1 != 0)
830 var = in;
831 else if (op0 != 0)
832 var = op0;
833 else
834 var = op1, neg_var_p = neg1_p;
836 /* Now do any needed negations. */
837 if (neg_litp_p)
838 *minus_litp = *litp, *litp = 0;
839 if (neg_conp_p && *conp)
840 *minus_conp = *conp, *conp = 0;
841 if (neg_var_p && var)
842 *minus_varp = var, var = 0;
844 else if (TREE_CONSTANT (in))
845 *conp = in;
846 else if (TREE_CODE (in) == BIT_NOT_EXPR
847 && code == PLUS_EXPR)
849 /* -1 - X is folded to ~X, undo that here. Do _not_ do this
850 when IN is constant. */
851 *litp = build_minus_one_cst (type);
852 *minus_varp = TREE_OPERAND (in, 0);
854 else
855 var = in;
857 if (negate_p)
859 if (*litp)
860 *minus_litp = *litp, *litp = 0;
861 else if (*minus_litp)
862 *litp = *minus_litp, *minus_litp = 0;
863 if (*conp)
864 *minus_conp = *conp, *conp = 0;
865 else if (*minus_conp)
866 *conp = *minus_conp, *minus_conp = 0;
867 if (var)
868 *minus_varp = var, var = 0;
869 else if (*minus_varp)
870 var = *minus_varp, *minus_varp = 0;
873 if (*litp
874 && TREE_OVERFLOW_P (*litp))
875 *litp = drop_tree_overflow (*litp);
876 if (*minus_litp
877 && TREE_OVERFLOW_P (*minus_litp))
878 *minus_litp = drop_tree_overflow (*minus_litp);
880 return var;
883 /* Re-associate trees split by the above function. T1 and T2 are
884 either expressions to associate or null. Return the new
885 expression, if any. LOC is the location of the new expression. If
886 we build an operation, do it in TYPE and with CODE. */
888 static tree
889 associate_trees (location_t loc, tree t1, tree t2, enum tree_code code, tree type)
891 if (t1 == 0)
893 gcc_assert (t2 == 0 || code != MINUS_EXPR);
894 return t2;
896 else if (t2 == 0)
897 return t1;
899 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
900 try to fold this since we will have infinite recursion. But do
901 deal with any NEGATE_EXPRs. */
902 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
903 || TREE_CODE (t1) == PLUS_EXPR || TREE_CODE (t2) == PLUS_EXPR
904 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
906 if (code == PLUS_EXPR)
908 if (TREE_CODE (t1) == NEGATE_EXPR)
909 return build2_loc (loc, MINUS_EXPR, type,
910 fold_convert_loc (loc, type, t2),
911 fold_convert_loc (loc, type,
912 TREE_OPERAND (t1, 0)));
913 else if (TREE_CODE (t2) == NEGATE_EXPR)
914 return build2_loc (loc, MINUS_EXPR, type,
915 fold_convert_loc (loc, type, t1),
916 fold_convert_loc (loc, type,
917 TREE_OPERAND (t2, 0)));
918 else if (integer_zerop (t2))
919 return fold_convert_loc (loc, type, t1);
921 else if (code == MINUS_EXPR)
923 if (integer_zerop (t2))
924 return fold_convert_loc (loc, type, t1);
927 return build2_loc (loc, code, type, fold_convert_loc (loc, type, t1),
928 fold_convert_loc (loc, type, t2));
931 return fold_build2_loc (loc, code, type, fold_convert_loc (loc, type, t1),
932 fold_convert_loc (loc, type, t2));
935 /* Check whether TYPE1 and TYPE2 are equivalent integer types, suitable
936 for use in int_const_binop, size_binop and size_diffop. */
938 static bool
939 int_binop_types_match_p (enum tree_code code, const_tree type1, const_tree type2)
941 if (!INTEGRAL_TYPE_P (type1) && !POINTER_TYPE_P (type1))
942 return false;
943 if (!INTEGRAL_TYPE_P (type2) && !POINTER_TYPE_P (type2))
944 return false;
946 switch (code)
948 case LSHIFT_EXPR:
949 case RSHIFT_EXPR:
950 case LROTATE_EXPR:
951 case RROTATE_EXPR:
952 return true;
954 default:
955 break;
958 return TYPE_UNSIGNED (type1) == TYPE_UNSIGNED (type2)
959 && TYPE_PRECISION (type1) == TYPE_PRECISION (type2)
960 && TYPE_MODE (type1) == TYPE_MODE (type2);
963 /* Subroutine of int_const_binop_1 that handles two INTEGER_CSTs. */
965 static tree
966 int_const_binop_2 (enum tree_code code, const_tree parg1, const_tree parg2,
967 int overflowable)
969 wide_int res;
970 tree t;
971 tree type = TREE_TYPE (parg1);
972 signop sign = TYPE_SIGN (type);
973 bool overflow = false;
975 wi::tree_to_wide_ref arg1 = wi::to_wide (parg1);
976 wide_int arg2 = wi::to_wide (parg2, TYPE_PRECISION (type));
978 switch (code)
980 case BIT_IOR_EXPR:
981 res = wi::bit_or (arg1, arg2);
982 break;
984 case BIT_XOR_EXPR:
985 res = wi::bit_xor (arg1, arg2);
986 break;
988 case BIT_AND_EXPR:
989 res = wi::bit_and (arg1, arg2);
990 break;
992 case RSHIFT_EXPR:
993 case LSHIFT_EXPR:
994 if (wi::neg_p (arg2))
996 arg2 = -arg2;
997 if (code == RSHIFT_EXPR)
998 code = LSHIFT_EXPR;
999 else
1000 code = RSHIFT_EXPR;
1003 if (code == RSHIFT_EXPR)
1004 /* It's unclear from the C standard whether shifts can overflow.
1005 The following code ignores overflow; perhaps a C standard
1006 interpretation ruling is needed. */
1007 res = wi::rshift (arg1, arg2, sign);
1008 else
1009 res = wi::lshift (arg1, arg2);
1010 break;
1012 case RROTATE_EXPR:
1013 case LROTATE_EXPR:
1014 if (wi::neg_p (arg2))
1016 arg2 = -arg2;
1017 if (code == RROTATE_EXPR)
1018 code = LROTATE_EXPR;
1019 else
1020 code = RROTATE_EXPR;
1023 if (code == RROTATE_EXPR)
1024 res = wi::rrotate (arg1, arg2);
1025 else
1026 res = wi::lrotate (arg1, arg2);
1027 break;
1029 case PLUS_EXPR:
1030 res = wi::add (arg1, arg2, sign, &overflow);
1031 break;
1033 case MINUS_EXPR:
1034 res = wi::sub (arg1, arg2, sign, &overflow);
1035 break;
1037 case MULT_EXPR:
1038 res = wi::mul (arg1, arg2, sign, &overflow);
1039 break;
1041 case MULT_HIGHPART_EXPR:
1042 res = wi::mul_high (arg1, arg2, sign);
1043 break;
1045 case TRUNC_DIV_EXPR:
1046 case EXACT_DIV_EXPR:
1047 if (arg2 == 0)
1048 return NULL_TREE;
1049 res = wi::div_trunc (arg1, arg2, sign, &overflow);
1050 break;
1052 case FLOOR_DIV_EXPR:
1053 if (arg2 == 0)
1054 return NULL_TREE;
1055 res = wi::div_floor (arg1, arg2, sign, &overflow);
1056 break;
1058 case CEIL_DIV_EXPR:
1059 if (arg2 == 0)
1060 return NULL_TREE;
1061 res = wi::div_ceil (arg1, arg2, sign, &overflow);
1062 break;
1064 case ROUND_DIV_EXPR:
1065 if (arg2 == 0)
1066 return NULL_TREE;
1067 res = wi::div_round (arg1, arg2, sign, &overflow);
1068 break;
1070 case TRUNC_MOD_EXPR:
1071 if (arg2 == 0)
1072 return NULL_TREE;
1073 res = wi::mod_trunc (arg1, arg2, sign, &overflow);
1074 break;
1076 case FLOOR_MOD_EXPR:
1077 if (arg2 == 0)
1078 return NULL_TREE;
1079 res = wi::mod_floor (arg1, arg2, sign, &overflow);
1080 break;
1082 case CEIL_MOD_EXPR:
1083 if (arg2 == 0)
1084 return NULL_TREE;
1085 res = wi::mod_ceil (arg1, arg2, sign, &overflow);
1086 break;
1088 case ROUND_MOD_EXPR:
1089 if (arg2 == 0)
1090 return NULL_TREE;
1091 res = wi::mod_round (arg1, arg2, sign, &overflow);
1092 break;
1094 case MIN_EXPR:
1095 res = wi::min (arg1, arg2, sign);
1096 break;
1098 case MAX_EXPR:
1099 res = wi::max (arg1, arg2, sign);
1100 break;
1102 default:
1103 return NULL_TREE;
1106 t = force_fit_type (type, res, overflowable,
1107 (((sign == SIGNED || overflowable == -1)
1108 && overflow)
1109 | TREE_OVERFLOW (parg1) | TREE_OVERFLOW (parg2)));
1111 return t;
1114 /* Combine two integer constants PARG1 and PARG2 under operation CODE
1115 to produce a new constant. Return NULL_TREE if we don't know how
1116 to evaluate CODE at compile-time. */
1118 static tree
1119 int_const_binop_1 (enum tree_code code, const_tree arg1, const_tree arg2,
1120 int overflowable)
1122 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg2) == INTEGER_CST)
1123 return int_const_binop_2 (code, arg1, arg2, overflowable);
1125 gcc_assert (NUM_POLY_INT_COEFFS != 1);
1127 if (poly_int_tree_p (arg1) && poly_int_tree_p (arg2))
1129 poly_wide_int res;
1130 bool overflow;
1131 tree type = TREE_TYPE (arg1);
1132 signop sign = TYPE_SIGN (type);
1133 switch (code)
1135 case PLUS_EXPR:
1136 res = wi::add (wi::to_poly_wide (arg1),
1137 wi::to_poly_wide (arg2), sign, &overflow);
1138 break;
1140 case MINUS_EXPR:
1141 res = wi::sub (wi::to_poly_wide (arg1),
1142 wi::to_poly_wide (arg2), sign, &overflow);
1143 break;
1145 case MULT_EXPR:
1146 if (TREE_CODE (arg2) == INTEGER_CST)
1147 res = wi::mul (wi::to_poly_wide (arg1),
1148 wi::to_wide (arg2), sign, &overflow);
1149 else if (TREE_CODE (arg1) == INTEGER_CST)
1150 res = wi::mul (wi::to_poly_wide (arg2),
1151 wi::to_wide (arg1), sign, &overflow);
1152 else
1153 return NULL_TREE;
1154 break;
1156 case LSHIFT_EXPR:
1157 if (TREE_CODE (arg2) == INTEGER_CST)
1158 res = wi::to_poly_wide (arg1) << wi::to_wide (arg2);
1159 else
1160 return NULL_TREE;
1161 break;
1163 case BIT_IOR_EXPR:
1164 if (TREE_CODE (arg2) != INTEGER_CST
1165 || !can_ior_p (wi::to_poly_wide (arg1), wi::to_wide (arg2),
1166 &res))
1167 return NULL_TREE;
1168 break;
1170 default:
1171 return NULL_TREE;
1173 return force_fit_type (type, res, overflowable,
1174 (((sign == SIGNED || overflowable == -1)
1175 && overflow)
1176 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2)));
1179 return NULL_TREE;
1182 tree
1183 int_const_binop (enum tree_code code, const_tree arg1, const_tree arg2)
1185 return int_const_binop_1 (code, arg1, arg2, 1);
1188 /* Return true if binary operation OP distributes over addition in operand
1189 OPNO, with the other operand being held constant. OPNO counts from 1. */
1191 static bool
1192 distributes_over_addition_p (tree_code op, int opno)
1194 switch (op)
1196 case PLUS_EXPR:
1197 case MINUS_EXPR:
1198 case MULT_EXPR:
1199 return true;
1201 case LSHIFT_EXPR:
1202 return opno == 1;
1204 default:
1205 return false;
1209 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1210 constant. We assume ARG1 and ARG2 have the same data type, or at least
1211 are the same kind of constant and the same machine mode. Return zero if
1212 combining the constants is not allowed in the current operating mode. */
1214 static tree
1215 const_binop (enum tree_code code, tree arg1, tree arg2)
1217 /* Sanity check for the recursive cases. */
1218 if (!arg1 || !arg2)
1219 return NULL_TREE;
1221 STRIP_NOPS (arg1);
1222 STRIP_NOPS (arg2);
1224 if (poly_int_tree_p (arg1) && poly_int_tree_p (arg2))
1226 if (code == POINTER_PLUS_EXPR)
1227 return int_const_binop (PLUS_EXPR,
1228 arg1, fold_convert (TREE_TYPE (arg1), arg2));
1230 return int_const_binop (code, arg1, arg2);
1233 if (TREE_CODE (arg1) == REAL_CST && TREE_CODE (arg2) == REAL_CST)
1235 machine_mode mode;
1236 REAL_VALUE_TYPE d1;
1237 REAL_VALUE_TYPE d2;
1238 REAL_VALUE_TYPE value;
1239 REAL_VALUE_TYPE result;
1240 bool inexact;
1241 tree t, type;
1243 /* The following codes are handled by real_arithmetic. */
1244 switch (code)
1246 case PLUS_EXPR:
1247 case MINUS_EXPR:
1248 case MULT_EXPR:
1249 case RDIV_EXPR:
1250 case MIN_EXPR:
1251 case MAX_EXPR:
1252 break;
1254 default:
1255 return NULL_TREE;
1258 d1 = TREE_REAL_CST (arg1);
1259 d2 = TREE_REAL_CST (arg2);
1261 type = TREE_TYPE (arg1);
1262 mode = TYPE_MODE (type);
1264 /* Don't perform operation if we honor signaling NaNs and
1265 either operand is a signaling NaN. */
1266 if (HONOR_SNANS (mode)
1267 && (REAL_VALUE_ISSIGNALING_NAN (d1)
1268 || REAL_VALUE_ISSIGNALING_NAN (d2)))
1269 return NULL_TREE;
1271 /* Don't perform operation if it would raise a division
1272 by zero exception. */
1273 if (code == RDIV_EXPR
1274 && real_equal (&d2, &dconst0)
1275 && (flag_trapping_math || ! MODE_HAS_INFINITIES (mode)))
1276 return NULL_TREE;
1278 /* If either operand is a NaN, just return it. Otherwise, set up
1279 for floating-point trap; we return an overflow. */
1280 if (REAL_VALUE_ISNAN (d1))
1282 /* Make resulting NaN value to be qNaN when flag_signaling_nans
1283 is off. */
1284 d1.signalling = 0;
1285 t = build_real (type, d1);
1286 return t;
1288 else if (REAL_VALUE_ISNAN (d2))
1290 /* Make resulting NaN value to be qNaN when flag_signaling_nans
1291 is off. */
1292 d2.signalling = 0;
1293 t = build_real (type, d2);
1294 return t;
1297 inexact = real_arithmetic (&value, code, &d1, &d2);
1298 real_convert (&result, mode, &value);
1300 /* Don't constant fold this floating point operation if
1301 the result has overflowed and flag_trapping_math. */
1302 if (flag_trapping_math
1303 && MODE_HAS_INFINITIES (mode)
1304 && REAL_VALUE_ISINF (result)
1305 && !REAL_VALUE_ISINF (d1)
1306 && !REAL_VALUE_ISINF (d2))
1307 return NULL_TREE;
1309 /* Don't constant fold this floating point operation if the
1310 result may dependent upon the run-time rounding mode and
1311 flag_rounding_math is set, or if GCC's software emulation
1312 is unable to accurately represent the result. */
1313 if ((flag_rounding_math
1314 || (MODE_COMPOSITE_P (mode) && !flag_unsafe_math_optimizations))
1315 && (inexact || !real_identical (&result, &value)))
1316 return NULL_TREE;
1318 t = build_real (type, result);
1320 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2);
1321 return t;
1324 if (TREE_CODE (arg1) == FIXED_CST)
1326 FIXED_VALUE_TYPE f1;
1327 FIXED_VALUE_TYPE f2;
1328 FIXED_VALUE_TYPE result;
1329 tree t, type;
1330 int sat_p;
1331 bool overflow_p;
1333 /* The following codes are handled by fixed_arithmetic. */
1334 switch (code)
1336 case PLUS_EXPR:
1337 case MINUS_EXPR:
1338 case MULT_EXPR:
1339 case TRUNC_DIV_EXPR:
1340 if (TREE_CODE (arg2) != FIXED_CST)
1341 return NULL_TREE;
1342 f2 = TREE_FIXED_CST (arg2);
1343 break;
1345 case LSHIFT_EXPR:
1346 case RSHIFT_EXPR:
1348 if (TREE_CODE (arg2) != INTEGER_CST)
1349 return NULL_TREE;
1350 wi::tree_to_wide_ref w2 = wi::to_wide (arg2);
1351 f2.data.high = w2.elt (1);
1352 f2.data.low = w2.ulow ();
1353 f2.mode = SImode;
1355 break;
1357 default:
1358 return NULL_TREE;
1361 f1 = TREE_FIXED_CST (arg1);
1362 type = TREE_TYPE (arg1);
1363 sat_p = TYPE_SATURATING (type);
1364 overflow_p = fixed_arithmetic (&result, code, &f1, &f2, sat_p);
1365 t = build_fixed (type, result);
1366 /* Propagate overflow flags. */
1367 if (overflow_p | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2))
1368 TREE_OVERFLOW (t) = 1;
1369 return t;
1372 if (TREE_CODE (arg1) == COMPLEX_CST && TREE_CODE (arg2) == COMPLEX_CST)
1374 tree type = TREE_TYPE (arg1);
1375 tree r1 = TREE_REALPART (arg1);
1376 tree i1 = TREE_IMAGPART (arg1);
1377 tree r2 = TREE_REALPART (arg2);
1378 tree i2 = TREE_IMAGPART (arg2);
1379 tree real, imag;
1381 switch (code)
1383 case PLUS_EXPR:
1384 case MINUS_EXPR:
1385 real = const_binop (code, r1, r2);
1386 imag = const_binop (code, i1, i2);
1387 break;
1389 case MULT_EXPR:
1390 if (COMPLEX_FLOAT_TYPE_P (type))
1391 return do_mpc_arg2 (arg1, arg2, type,
1392 /* do_nonfinite= */ folding_initializer,
1393 mpc_mul);
1395 real = const_binop (MINUS_EXPR,
1396 const_binop (MULT_EXPR, r1, r2),
1397 const_binop (MULT_EXPR, i1, i2));
1398 imag = const_binop (PLUS_EXPR,
1399 const_binop (MULT_EXPR, r1, i2),
1400 const_binop (MULT_EXPR, i1, r2));
1401 break;
1403 case RDIV_EXPR:
1404 if (COMPLEX_FLOAT_TYPE_P (type))
1405 return do_mpc_arg2 (arg1, arg2, type,
1406 /* do_nonfinite= */ folding_initializer,
1407 mpc_div);
1408 /* Fallthru. */
1409 case TRUNC_DIV_EXPR:
1410 case CEIL_DIV_EXPR:
1411 case FLOOR_DIV_EXPR:
1412 case ROUND_DIV_EXPR:
1413 if (flag_complex_method == 0)
1415 /* Keep this algorithm in sync with
1416 tree-complex.c:expand_complex_div_straight().
1418 Expand complex division to scalars, straightforward algorithm.
1419 a / b = ((ar*br + ai*bi)/t) + i((ai*br - ar*bi)/t)
1420 t = br*br + bi*bi
1422 tree magsquared
1423 = const_binop (PLUS_EXPR,
1424 const_binop (MULT_EXPR, r2, r2),
1425 const_binop (MULT_EXPR, i2, i2));
1426 tree t1
1427 = const_binop (PLUS_EXPR,
1428 const_binop (MULT_EXPR, r1, r2),
1429 const_binop (MULT_EXPR, i1, i2));
1430 tree t2
1431 = const_binop (MINUS_EXPR,
1432 const_binop (MULT_EXPR, i1, r2),
1433 const_binop (MULT_EXPR, r1, i2));
1435 real = const_binop (code, t1, magsquared);
1436 imag = const_binop (code, t2, magsquared);
1438 else
1440 /* Keep this algorithm in sync with
1441 tree-complex.c:expand_complex_div_wide().
1443 Expand complex division to scalars, modified algorithm to minimize
1444 overflow with wide input ranges. */
1445 tree compare = fold_build2 (LT_EXPR, boolean_type_node,
1446 fold_abs_const (r2, TREE_TYPE (type)),
1447 fold_abs_const (i2, TREE_TYPE (type)));
1449 if (integer_nonzerop (compare))
1451 /* In the TRUE branch, we compute
1452 ratio = br/bi;
1453 div = (br * ratio) + bi;
1454 tr = (ar * ratio) + ai;
1455 ti = (ai * ratio) - ar;
1456 tr = tr / div;
1457 ti = ti / div; */
1458 tree ratio = const_binop (code, r2, i2);
1459 tree div = const_binop (PLUS_EXPR, i2,
1460 const_binop (MULT_EXPR, r2, ratio));
1461 real = const_binop (MULT_EXPR, r1, ratio);
1462 real = const_binop (PLUS_EXPR, real, i1);
1463 real = const_binop (code, real, div);
1465 imag = const_binop (MULT_EXPR, i1, ratio);
1466 imag = const_binop (MINUS_EXPR, imag, r1);
1467 imag = const_binop (code, imag, div);
1469 else
1471 /* In the FALSE branch, we compute
1472 ratio = d/c;
1473 divisor = (d * ratio) + c;
1474 tr = (b * ratio) + a;
1475 ti = b - (a * ratio);
1476 tr = tr / div;
1477 ti = ti / div; */
1478 tree ratio = const_binop (code, i2, r2);
1479 tree div = const_binop (PLUS_EXPR, r2,
1480 const_binop (MULT_EXPR, i2, ratio));
1482 real = const_binop (MULT_EXPR, i1, ratio);
1483 real = const_binop (PLUS_EXPR, real, r1);
1484 real = const_binop (code, real, div);
1486 imag = const_binop (MULT_EXPR, r1, ratio);
1487 imag = const_binop (MINUS_EXPR, i1, imag);
1488 imag = const_binop (code, imag, div);
1491 break;
1493 default:
1494 return NULL_TREE;
1497 if (real && imag)
1498 return build_complex (type, real, imag);
1501 if (TREE_CODE (arg1) == VECTOR_CST
1502 && TREE_CODE (arg2) == VECTOR_CST
1503 && known_eq (TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg1)),
1504 TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg2))))
1506 tree type = TREE_TYPE (arg1);
1507 bool step_ok_p;
1508 if (VECTOR_CST_STEPPED_P (arg1)
1509 && VECTOR_CST_STEPPED_P (arg2))
1510 /* We can operate directly on the encoding if:
1512 a3 - a2 == a2 - a1 && b3 - b2 == b2 - b1
1513 implies
1514 (a3 op b3) - (a2 op b2) == (a2 op b2) - (a1 op b1)
1516 Addition and subtraction are the supported operators
1517 for which this is true. */
1518 step_ok_p = (code == PLUS_EXPR || code == MINUS_EXPR);
1519 else if (VECTOR_CST_STEPPED_P (arg1))
1520 /* We can operate directly on stepped encodings if:
1522 a3 - a2 == a2 - a1
1523 implies:
1524 (a3 op c) - (a2 op c) == (a2 op c) - (a1 op c)
1526 which is true if (x -> x op c) distributes over addition. */
1527 step_ok_p = distributes_over_addition_p (code, 1);
1528 else
1529 /* Similarly in reverse. */
1530 step_ok_p = distributes_over_addition_p (code, 2);
1531 tree_vector_builder elts;
1532 if (!elts.new_binary_operation (type, arg1, arg2, step_ok_p))
1533 return NULL_TREE;
1534 unsigned int count = elts.encoded_nelts ();
1535 for (unsigned int i = 0; i < count; ++i)
1537 tree elem1 = VECTOR_CST_ELT (arg1, i);
1538 tree elem2 = VECTOR_CST_ELT (arg2, i);
1540 tree elt = const_binop (code, elem1, elem2);
1542 /* It is possible that const_binop cannot handle the given
1543 code and return NULL_TREE */
1544 if (elt == NULL_TREE)
1545 return NULL_TREE;
1546 elts.quick_push (elt);
1549 return elts.build ();
1552 /* Shifts allow a scalar offset for a vector. */
1553 if (TREE_CODE (arg1) == VECTOR_CST
1554 && TREE_CODE (arg2) == INTEGER_CST)
1556 tree type = TREE_TYPE (arg1);
1557 bool step_ok_p = distributes_over_addition_p (code, 1);
1558 tree_vector_builder elts;
1559 if (!elts.new_unary_operation (type, arg1, step_ok_p))
1560 return NULL_TREE;
1561 unsigned int count = elts.encoded_nelts ();
1562 for (unsigned int i = 0; i < count; ++i)
1564 tree elem1 = VECTOR_CST_ELT (arg1, i);
1566 tree elt = const_binop (code, elem1, arg2);
1568 /* It is possible that const_binop cannot handle the given
1569 code and return NULL_TREE. */
1570 if (elt == NULL_TREE)
1571 return NULL_TREE;
1572 elts.quick_push (elt);
1575 return elts.build ();
1577 return NULL_TREE;
1580 /* Overload that adds a TYPE parameter to be able to dispatch
1581 to fold_relational_const. */
1583 tree
1584 const_binop (enum tree_code code, tree type, tree arg1, tree arg2)
1586 if (TREE_CODE_CLASS (code) == tcc_comparison)
1587 return fold_relational_const (code, type, arg1, arg2);
1589 /* ??? Until we make the const_binop worker take the type of the
1590 result as argument put those cases that need it here. */
1591 switch (code)
1593 case VEC_SERIES_EXPR:
1594 if (CONSTANT_CLASS_P (arg1)
1595 && CONSTANT_CLASS_P (arg2))
1596 return build_vec_series (type, arg1, arg2);
1597 return NULL_TREE;
1599 case COMPLEX_EXPR:
1600 if ((TREE_CODE (arg1) == REAL_CST
1601 && TREE_CODE (arg2) == REAL_CST)
1602 || (TREE_CODE (arg1) == INTEGER_CST
1603 && TREE_CODE (arg2) == INTEGER_CST))
1604 return build_complex (type, arg1, arg2);
1605 return NULL_TREE;
1607 case POINTER_DIFF_EXPR:
1608 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg2) == INTEGER_CST)
1610 offset_int res = wi::sub (wi::to_offset (arg1),
1611 wi::to_offset (arg2));
1612 return force_fit_type (type, res, 1,
1613 TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
1615 return NULL_TREE;
1617 case VEC_PACK_TRUNC_EXPR:
1618 case VEC_PACK_FIX_TRUNC_EXPR:
1620 unsigned int HOST_WIDE_INT out_nelts, in_nelts, i;
1622 if (TREE_CODE (arg1) != VECTOR_CST
1623 || TREE_CODE (arg2) != VECTOR_CST)
1624 return NULL_TREE;
1626 if (!VECTOR_CST_NELTS (arg1).is_constant (&in_nelts))
1627 return NULL_TREE;
1629 out_nelts = in_nelts * 2;
1630 gcc_assert (known_eq (in_nelts, VECTOR_CST_NELTS (arg2))
1631 && known_eq (out_nelts, TYPE_VECTOR_SUBPARTS (type)));
1633 tree_vector_builder elts (type, out_nelts, 1);
1634 for (i = 0; i < out_nelts; i++)
1636 tree elt = (i < in_nelts
1637 ? VECTOR_CST_ELT (arg1, i)
1638 : VECTOR_CST_ELT (arg2, i - in_nelts));
1639 elt = fold_convert_const (code == VEC_PACK_TRUNC_EXPR
1640 ? NOP_EXPR : FIX_TRUNC_EXPR,
1641 TREE_TYPE (type), elt);
1642 if (elt == NULL_TREE || !CONSTANT_CLASS_P (elt))
1643 return NULL_TREE;
1644 elts.quick_push (elt);
1647 return elts.build ();
1650 case VEC_WIDEN_MULT_LO_EXPR:
1651 case VEC_WIDEN_MULT_HI_EXPR:
1652 case VEC_WIDEN_MULT_EVEN_EXPR:
1653 case VEC_WIDEN_MULT_ODD_EXPR:
1655 unsigned HOST_WIDE_INT out_nelts, in_nelts, out, ofs, scale;
1657 if (TREE_CODE (arg1) != VECTOR_CST || TREE_CODE (arg2) != VECTOR_CST)
1658 return NULL_TREE;
1660 if (!VECTOR_CST_NELTS (arg1).is_constant (&in_nelts))
1661 return NULL_TREE;
1662 out_nelts = in_nelts / 2;
1663 gcc_assert (known_eq (in_nelts, VECTOR_CST_NELTS (arg2))
1664 && known_eq (out_nelts, TYPE_VECTOR_SUBPARTS (type)));
1666 if (code == VEC_WIDEN_MULT_LO_EXPR)
1667 scale = 0, ofs = BYTES_BIG_ENDIAN ? out_nelts : 0;
1668 else if (code == VEC_WIDEN_MULT_HI_EXPR)
1669 scale = 0, ofs = BYTES_BIG_ENDIAN ? 0 : out_nelts;
1670 else if (code == VEC_WIDEN_MULT_EVEN_EXPR)
1671 scale = 1, ofs = 0;
1672 else /* if (code == VEC_WIDEN_MULT_ODD_EXPR) */
1673 scale = 1, ofs = 1;
1675 tree_vector_builder elts (type, out_nelts, 1);
1676 for (out = 0; out < out_nelts; out++)
1678 unsigned int in = (out << scale) + ofs;
1679 tree t1 = fold_convert_const (NOP_EXPR, TREE_TYPE (type),
1680 VECTOR_CST_ELT (arg1, in));
1681 tree t2 = fold_convert_const (NOP_EXPR, TREE_TYPE (type),
1682 VECTOR_CST_ELT (arg2, in));
1684 if (t1 == NULL_TREE || t2 == NULL_TREE)
1685 return NULL_TREE;
1686 tree elt = const_binop (MULT_EXPR, t1, t2);
1687 if (elt == NULL_TREE || !CONSTANT_CLASS_P (elt))
1688 return NULL_TREE;
1689 elts.quick_push (elt);
1692 return elts.build ();
1695 default:;
1698 if (TREE_CODE_CLASS (code) != tcc_binary)
1699 return NULL_TREE;
1701 /* Make sure type and arg0 have the same saturating flag. */
1702 gcc_checking_assert (TYPE_SATURATING (type)
1703 == TYPE_SATURATING (TREE_TYPE (arg1)));
1705 return const_binop (code, arg1, arg2);
1708 /* Compute CODE ARG1 with resulting type TYPE with ARG1 being constant.
1709 Return zero if computing the constants is not possible. */
1711 tree
1712 const_unop (enum tree_code code, tree type, tree arg0)
1714 /* Don't perform the operation, other than NEGATE and ABS, if
1715 flag_signaling_nans is on and the operand is a signaling NaN. */
1716 if (TREE_CODE (arg0) == REAL_CST
1717 && HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
1718 && REAL_VALUE_ISSIGNALING_NAN (TREE_REAL_CST (arg0))
1719 && code != NEGATE_EXPR
1720 && code != ABS_EXPR)
1721 return NULL_TREE;
1723 switch (code)
1725 CASE_CONVERT:
1726 case FLOAT_EXPR:
1727 case FIX_TRUNC_EXPR:
1728 case FIXED_CONVERT_EXPR:
1729 return fold_convert_const (code, type, arg0);
1731 case ADDR_SPACE_CONVERT_EXPR:
1732 /* If the source address is 0, and the source address space
1733 cannot have a valid object at 0, fold to dest type null. */
1734 if (integer_zerop (arg0)
1735 && !(targetm.addr_space.zero_address_valid
1736 (TYPE_ADDR_SPACE (TREE_TYPE (TREE_TYPE (arg0))))))
1737 return fold_convert_const (code, type, arg0);
1738 break;
1740 case VIEW_CONVERT_EXPR:
1741 return fold_view_convert_expr (type, arg0);
1743 case NEGATE_EXPR:
1745 /* Can't call fold_negate_const directly here as that doesn't
1746 handle all cases and we might not be able to negate some
1747 constants. */
1748 tree tem = fold_negate_expr (UNKNOWN_LOCATION, arg0);
1749 if (tem && CONSTANT_CLASS_P (tem))
1750 return tem;
1751 break;
1754 case ABS_EXPR:
1755 if (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST)
1756 return fold_abs_const (arg0, type);
1757 break;
1759 case CONJ_EXPR:
1760 if (TREE_CODE (arg0) == COMPLEX_CST)
1762 tree ipart = fold_negate_const (TREE_IMAGPART (arg0),
1763 TREE_TYPE (type));
1764 return build_complex (type, TREE_REALPART (arg0), ipart);
1766 break;
1768 case BIT_NOT_EXPR:
1769 if (TREE_CODE (arg0) == INTEGER_CST)
1770 return fold_not_const (arg0, type);
1771 else if (POLY_INT_CST_P (arg0))
1772 return wide_int_to_tree (type, -poly_int_cst_value (arg0));
1773 /* Perform BIT_NOT_EXPR on each element individually. */
1774 else if (TREE_CODE (arg0) == VECTOR_CST)
1776 tree elem;
1778 /* This can cope with stepped encodings because ~x == -1 - x. */
1779 tree_vector_builder elements;
1780 elements.new_unary_operation (type, arg0, true);
1781 unsigned int i, count = elements.encoded_nelts ();
1782 for (i = 0; i < count; ++i)
1784 elem = VECTOR_CST_ELT (arg0, i);
1785 elem = const_unop (BIT_NOT_EXPR, TREE_TYPE (type), elem);
1786 if (elem == NULL_TREE)
1787 break;
1788 elements.quick_push (elem);
1790 if (i == count)
1791 return elements.build ();
1793 break;
1795 case TRUTH_NOT_EXPR:
1796 if (TREE_CODE (arg0) == INTEGER_CST)
1797 return constant_boolean_node (integer_zerop (arg0), type);
1798 break;
1800 case REALPART_EXPR:
1801 if (TREE_CODE (arg0) == COMPLEX_CST)
1802 return fold_convert (type, TREE_REALPART (arg0));
1803 break;
1805 case IMAGPART_EXPR:
1806 if (TREE_CODE (arg0) == COMPLEX_CST)
1807 return fold_convert (type, TREE_IMAGPART (arg0));
1808 break;
1810 case VEC_UNPACK_LO_EXPR:
1811 case VEC_UNPACK_HI_EXPR:
1812 case VEC_UNPACK_FLOAT_LO_EXPR:
1813 case VEC_UNPACK_FLOAT_HI_EXPR:
1815 unsigned HOST_WIDE_INT out_nelts, in_nelts, i;
1816 enum tree_code subcode;
1818 if (TREE_CODE (arg0) != VECTOR_CST)
1819 return NULL_TREE;
1821 if (!VECTOR_CST_NELTS (arg0).is_constant (&in_nelts))
1822 return NULL_TREE;
1823 out_nelts = in_nelts / 2;
1824 gcc_assert (known_eq (out_nelts, TYPE_VECTOR_SUBPARTS (type)));
1826 unsigned int offset = 0;
1827 if ((!BYTES_BIG_ENDIAN) ^ (code == VEC_UNPACK_LO_EXPR
1828 || code == VEC_UNPACK_FLOAT_LO_EXPR))
1829 offset = out_nelts;
1831 if (code == VEC_UNPACK_LO_EXPR || code == VEC_UNPACK_HI_EXPR)
1832 subcode = NOP_EXPR;
1833 else
1834 subcode = FLOAT_EXPR;
1836 tree_vector_builder elts (type, out_nelts, 1);
1837 for (i = 0; i < out_nelts; i++)
1839 tree elt = fold_convert_const (subcode, TREE_TYPE (type),
1840 VECTOR_CST_ELT (arg0, i + offset));
1841 if (elt == NULL_TREE || !CONSTANT_CLASS_P (elt))
1842 return NULL_TREE;
1843 elts.quick_push (elt);
1846 return elts.build ();
1849 case VEC_DUPLICATE_EXPR:
1850 if (CONSTANT_CLASS_P (arg0))
1851 return build_vector_from_val (type, arg0);
1852 return NULL_TREE;
1854 default:
1855 break;
1858 return NULL_TREE;
1861 /* Create a sizetype INT_CST node with NUMBER sign extended. KIND
1862 indicates which particular sizetype to create. */
1864 tree
1865 size_int_kind (poly_int64 number, enum size_type_kind kind)
1867 return build_int_cst (sizetype_tab[(int) kind], number);
1870 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1871 is a tree code. The type of the result is taken from the operands.
1872 Both must be equivalent integer types, ala int_binop_types_match_p.
1873 If the operands are constant, so is the result. */
1875 tree
1876 size_binop_loc (location_t loc, enum tree_code code, tree arg0, tree arg1)
1878 tree type = TREE_TYPE (arg0);
1880 if (arg0 == error_mark_node || arg1 == error_mark_node)
1881 return error_mark_node;
1883 gcc_assert (int_binop_types_match_p (code, TREE_TYPE (arg0),
1884 TREE_TYPE (arg1)));
1886 /* Handle the special case of two poly_int constants faster. */
1887 if (poly_int_tree_p (arg0) && poly_int_tree_p (arg1))
1889 /* And some specific cases even faster than that. */
1890 if (code == PLUS_EXPR)
1892 if (integer_zerop (arg0) && !TREE_OVERFLOW (arg0))
1893 return arg1;
1894 if (integer_zerop (arg1) && !TREE_OVERFLOW (arg1))
1895 return arg0;
1897 else if (code == MINUS_EXPR)
1899 if (integer_zerop (arg1) && !TREE_OVERFLOW (arg1))
1900 return arg0;
1902 else if (code == MULT_EXPR)
1904 if (integer_onep (arg0) && !TREE_OVERFLOW (arg0))
1905 return arg1;
1908 /* Handle general case of two integer constants. For sizetype
1909 constant calculations we always want to know about overflow,
1910 even in the unsigned case. */
1911 tree res = int_const_binop_1 (code, arg0, arg1, -1);
1912 if (res != NULL_TREE)
1913 return res;
1916 return fold_build2_loc (loc, code, type, arg0, arg1);
1919 /* Given two values, either both of sizetype or both of bitsizetype,
1920 compute the difference between the two values. Return the value
1921 in signed type corresponding to the type of the operands. */
1923 tree
1924 size_diffop_loc (location_t loc, tree arg0, tree arg1)
1926 tree type = TREE_TYPE (arg0);
1927 tree ctype;
1929 gcc_assert (int_binop_types_match_p (MINUS_EXPR, TREE_TYPE (arg0),
1930 TREE_TYPE (arg1)));
1932 /* If the type is already signed, just do the simple thing. */
1933 if (!TYPE_UNSIGNED (type))
1934 return size_binop_loc (loc, MINUS_EXPR, arg0, arg1);
1936 if (type == sizetype)
1937 ctype = ssizetype;
1938 else if (type == bitsizetype)
1939 ctype = sbitsizetype;
1940 else
1941 ctype = signed_type_for (type);
1943 /* If either operand is not a constant, do the conversions to the signed
1944 type and subtract. The hardware will do the right thing with any
1945 overflow in the subtraction. */
1946 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
1947 return size_binop_loc (loc, MINUS_EXPR,
1948 fold_convert_loc (loc, ctype, arg0),
1949 fold_convert_loc (loc, ctype, arg1));
1951 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
1952 Otherwise, subtract the other way, convert to CTYPE (we know that can't
1953 overflow) and negate (which can't either). Special-case a result
1954 of zero while we're here. */
1955 if (tree_int_cst_equal (arg0, arg1))
1956 return build_int_cst (ctype, 0);
1957 else if (tree_int_cst_lt (arg1, arg0))
1958 return fold_convert_loc (loc, ctype,
1959 size_binop_loc (loc, MINUS_EXPR, arg0, arg1));
1960 else
1961 return size_binop_loc (loc, MINUS_EXPR, build_int_cst (ctype, 0),
1962 fold_convert_loc (loc, ctype,
1963 size_binop_loc (loc,
1964 MINUS_EXPR,
1965 arg1, arg0)));
1968 /* A subroutine of fold_convert_const handling conversions of an
1969 INTEGER_CST to another integer type. */
1971 static tree
1972 fold_convert_const_int_from_int (tree type, const_tree arg1)
1974 /* Given an integer constant, make new constant with new type,
1975 appropriately sign-extended or truncated. Use widest_int
1976 so that any extension is done according ARG1's type. */
1977 return force_fit_type (type, wi::to_widest (arg1),
1978 !POINTER_TYPE_P (TREE_TYPE (arg1)),
1979 TREE_OVERFLOW (arg1));
1982 /* A subroutine of fold_convert_const handling conversions a REAL_CST
1983 to an integer type. */
1985 static tree
1986 fold_convert_const_int_from_real (enum tree_code code, tree type, const_tree arg1)
1988 bool overflow = false;
1989 tree t;
1991 /* The following code implements the floating point to integer
1992 conversion rules required by the Java Language Specification,
1993 that IEEE NaNs are mapped to zero and values that overflow
1994 the target precision saturate, i.e. values greater than
1995 INT_MAX are mapped to INT_MAX, and values less than INT_MIN
1996 are mapped to INT_MIN. These semantics are allowed by the
1997 C and C++ standards that simply state that the behavior of
1998 FP-to-integer conversion is unspecified upon overflow. */
2000 wide_int val;
2001 REAL_VALUE_TYPE r;
2002 REAL_VALUE_TYPE x = TREE_REAL_CST (arg1);
2004 switch (code)
2006 case FIX_TRUNC_EXPR:
2007 real_trunc (&r, VOIDmode, &x);
2008 break;
2010 default:
2011 gcc_unreachable ();
2014 /* If R is NaN, return zero and show we have an overflow. */
2015 if (REAL_VALUE_ISNAN (r))
2017 overflow = true;
2018 val = wi::zero (TYPE_PRECISION (type));
2021 /* See if R is less than the lower bound or greater than the
2022 upper bound. */
2024 if (! overflow)
2026 tree lt = TYPE_MIN_VALUE (type);
2027 REAL_VALUE_TYPE l = real_value_from_int_cst (NULL_TREE, lt);
2028 if (real_less (&r, &l))
2030 overflow = true;
2031 val = wi::to_wide (lt);
2035 if (! overflow)
2037 tree ut = TYPE_MAX_VALUE (type);
2038 if (ut)
2040 REAL_VALUE_TYPE u = real_value_from_int_cst (NULL_TREE, ut);
2041 if (real_less (&u, &r))
2043 overflow = true;
2044 val = wi::to_wide (ut);
2049 if (! overflow)
2050 val = real_to_integer (&r, &overflow, TYPE_PRECISION (type));
2052 t = force_fit_type (type, val, -1, overflow | TREE_OVERFLOW (arg1));
2053 return t;
2056 /* A subroutine of fold_convert_const handling conversions of a
2057 FIXED_CST to an integer type. */
2059 static tree
2060 fold_convert_const_int_from_fixed (tree type, const_tree arg1)
2062 tree t;
2063 double_int temp, temp_trunc;
2064 scalar_mode mode;
2066 /* Right shift FIXED_CST to temp by fbit. */
2067 temp = TREE_FIXED_CST (arg1).data;
2068 mode = TREE_FIXED_CST (arg1).mode;
2069 if (GET_MODE_FBIT (mode) < HOST_BITS_PER_DOUBLE_INT)
2071 temp = temp.rshift (GET_MODE_FBIT (mode),
2072 HOST_BITS_PER_DOUBLE_INT,
2073 SIGNED_FIXED_POINT_MODE_P (mode));
2075 /* Left shift temp to temp_trunc by fbit. */
2076 temp_trunc = temp.lshift (GET_MODE_FBIT (mode),
2077 HOST_BITS_PER_DOUBLE_INT,
2078 SIGNED_FIXED_POINT_MODE_P (mode));
2080 else
2082 temp = double_int_zero;
2083 temp_trunc = double_int_zero;
2086 /* If FIXED_CST is negative, we need to round the value toward 0.
2087 By checking if the fractional bits are not zero to add 1 to temp. */
2088 if (SIGNED_FIXED_POINT_MODE_P (mode)
2089 && temp_trunc.is_negative ()
2090 && TREE_FIXED_CST (arg1).data != temp_trunc)
2091 temp += double_int_one;
2093 /* Given a fixed-point constant, make new constant with new type,
2094 appropriately sign-extended or truncated. */
2095 t = force_fit_type (type, temp, -1,
2096 (temp.is_negative ()
2097 && (TYPE_UNSIGNED (type)
2098 < TYPE_UNSIGNED (TREE_TYPE (arg1))))
2099 | TREE_OVERFLOW (arg1));
2101 return t;
2104 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2105 to another floating point type. */
2107 static tree
2108 fold_convert_const_real_from_real (tree type, const_tree arg1)
2110 REAL_VALUE_TYPE value;
2111 tree t;
2113 /* Don't perform the operation if flag_signaling_nans is on
2114 and the operand is a signaling NaN. */
2115 if (HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1)))
2116 && REAL_VALUE_ISSIGNALING_NAN (TREE_REAL_CST (arg1)))
2117 return NULL_TREE;
2119 real_convert (&value, TYPE_MODE (type), &TREE_REAL_CST (arg1));
2120 t = build_real (type, value);
2122 /* If converting an infinity or NAN to a representation that doesn't
2123 have one, set the overflow bit so that we can produce some kind of
2124 error message at the appropriate point if necessary. It's not the
2125 most user-friendly message, but it's better than nothing. */
2126 if (REAL_VALUE_ISINF (TREE_REAL_CST (arg1))
2127 && !MODE_HAS_INFINITIES (TYPE_MODE (type)))
2128 TREE_OVERFLOW (t) = 1;
2129 else if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1))
2130 && !MODE_HAS_NANS (TYPE_MODE (type)))
2131 TREE_OVERFLOW (t) = 1;
2132 /* Regular overflow, conversion produced an infinity in a mode that
2133 can't represent them. */
2134 else if (!MODE_HAS_INFINITIES (TYPE_MODE (type))
2135 && REAL_VALUE_ISINF (value)
2136 && !REAL_VALUE_ISINF (TREE_REAL_CST (arg1)))
2137 TREE_OVERFLOW (t) = 1;
2138 else
2139 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1);
2140 return t;
2143 /* A subroutine of fold_convert_const handling conversions a FIXED_CST
2144 to a floating point type. */
2146 static tree
2147 fold_convert_const_real_from_fixed (tree type, const_tree arg1)
2149 REAL_VALUE_TYPE value;
2150 tree t;
2152 real_convert_from_fixed (&value, SCALAR_FLOAT_TYPE_MODE (type),
2153 &TREE_FIXED_CST (arg1));
2154 t = build_real (type, value);
2156 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1);
2157 return t;
2160 /* A subroutine of fold_convert_const handling conversions a FIXED_CST
2161 to another fixed-point type. */
2163 static tree
2164 fold_convert_const_fixed_from_fixed (tree type, const_tree arg1)
2166 FIXED_VALUE_TYPE value;
2167 tree t;
2168 bool overflow_p;
2170 overflow_p = fixed_convert (&value, SCALAR_TYPE_MODE (type),
2171 &TREE_FIXED_CST (arg1), TYPE_SATURATING (type));
2172 t = build_fixed (type, value);
2174 /* Propagate overflow flags. */
2175 if (overflow_p | TREE_OVERFLOW (arg1))
2176 TREE_OVERFLOW (t) = 1;
2177 return t;
2180 /* A subroutine of fold_convert_const handling conversions an INTEGER_CST
2181 to a fixed-point type. */
2183 static tree
2184 fold_convert_const_fixed_from_int (tree type, const_tree arg1)
2186 FIXED_VALUE_TYPE value;
2187 tree t;
2188 bool overflow_p;
2189 double_int di;
2191 gcc_assert (TREE_INT_CST_NUNITS (arg1) <= 2);
2193 di.low = TREE_INT_CST_ELT (arg1, 0);
2194 if (TREE_INT_CST_NUNITS (arg1) == 1)
2195 di.high = (HOST_WIDE_INT) di.low < 0 ? HOST_WIDE_INT_M1 : 0;
2196 else
2197 di.high = TREE_INT_CST_ELT (arg1, 1);
2199 overflow_p = fixed_convert_from_int (&value, SCALAR_TYPE_MODE (type), di,
2200 TYPE_UNSIGNED (TREE_TYPE (arg1)),
2201 TYPE_SATURATING (type));
2202 t = build_fixed (type, value);
2204 /* Propagate overflow flags. */
2205 if (overflow_p | TREE_OVERFLOW (arg1))
2206 TREE_OVERFLOW (t) = 1;
2207 return t;
2210 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2211 to a fixed-point type. */
2213 static tree
2214 fold_convert_const_fixed_from_real (tree type, const_tree arg1)
2216 FIXED_VALUE_TYPE value;
2217 tree t;
2218 bool overflow_p;
2220 overflow_p = fixed_convert_from_real (&value, SCALAR_TYPE_MODE (type),
2221 &TREE_REAL_CST (arg1),
2222 TYPE_SATURATING (type));
2223 t = build_fixed (type, value);
2225 /* Propagate overflow flags. */
2226 if (overflow_p | TREE_OVERFLOW (arg1))
2227 TREE_OVERFLOW (t) = 1;
2228 return t;
2231 /* Attempt to fold type conversion operation CODE of expression ARG1 to
2232 type TYPE. If no simplification can be done return NULL_TREE. */
2234 static tree
2235 fold_convert_const (enum tree_code code, tree type, tree arg1)
2237 tree arg_type = TREE_TYPE (arg1);
2238 if (arg_type == type)
2239 return arg1;
2241 /* We can't widen types, since the runtime value could overflow the
2242 original type before being extended to the new type. */
2243 if (POLY_INT_CST_P (arg1)
2244 && (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
2245 && TYPE_PRECISION (type) <= TYPE_PRECISION (arg_type))
2246 return build_poly_int_cst (type,
2247 poly_wide_int::from (poly_int_cst_value (arg1),
2248 TYPE_PRECISION (type),
2249 TYPE_SIGN (arg_type)));
2251 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type)
2252 || TREE_CODE (type) == OFFSET_TYPE)
2254 if (TREE_CODE (arg1) == INTEGER_CST)
2255 return fold_convert_const_int_from_int (type, arg1);
2256 else if (TREE_CODE (arg1) == REAL_CST)
2257 return fold_convert_const_int_from_real (code, type, arg1);
2258 else if (TREE_CODE (arg1) == FIXED_CST)
2259 return fold_convert_const_int_from_fixed (type, arg1);
2261 else if (TREE_CODE (type) == REAL_TYPE)
2263 if (TREE_CODE (arg1) == INTEGER_CST)
2264 return build_real_from_int_cst (type, arg1);
2265 else if (TREE_CODE (arg1) == REAL_CST)
2266 return fold_convert_const_real_from_real (type, arg1);
2267 else if (TREE_CODE (arg1) == FIXED_CST)
2268 return fold_convert_const_real_from_fixed (type, arg1);
2270 else if (TREE_CODE (type) == FIXED_POINT_TYPE)
2272 if (TREE_CODE (arg1) == FIXED_CST)
2273 return fold_convert_const_fixed_from_fixed (type, arg1);
2274 else if (TREE_CODE (arg1) == INTEGER_CST)
2275 return fold_convert_const_fixed_from_int (type, arg1);
2276 else if (TREE_CODE (arg1) == REAL_CST)
2277 return fold_convert_const_fixed_from_real (type, arg1);
2279 else if (TREE_CODE (type) == VECTOR_TYPE)
2281 if (TREE_CODE (arg1) == VECTOR_CST
2282 && known_eq (TYPE_VECTOR_SUBPARTS (type), VECTOR_CST_NELTS (arg1)))
2284 tree elttype = TREE_TYPE (type);
2285 tree arg1_elttype = TREE_TYPE (TREE_TYPE (arg1));
2286 /* We can't handle steps directly when extending, since the
2287 values need to wrap at the original precision first. */
2288 bool step_ok_p
2289 = (INTEGRAL_TYPE_P (elttype)
2290 && INTEGRAL_TYPE_P (arg1_elttype)
2291 && TYPE_PRECISION (elttype) <= TYPE_PRECISION (arg1_elttype));
2292 tree_vector_builder v;
2293 if (!v.new_unary_operation (type, arg1, step_ok_p))
2294 return NULL_TREE;
2295 unsigned int len = v.encoded_nelts ();
2296 for (unsigned int i = 0; i < len; ++i)
2298 tree elt = VECTOR_CST_ELT (arg1, i);
2299 tree cvt = fold_convert_const (code, elttype, elt);
2300 if (cvt == NULL_TREE)
2301 return NULL_TREE;
2302 v.quick_push (cvt);
2304 return v.build ();
2307 return NULL_TREE;
2310 /* Construct a vector of zero elements of vector type TYPE. */
2312 static tree
2313 build_zero_vector (tree type)
2315 tree t;
2317 t = fold_convert_const (NOP_EXPR, TREE_TYPE (type), integer_zero_node);
2318 return build_vector_from_val (type, t);
2321 /* Returns true, if ARG is convertible to TYPE using a NOP_EXPR. */
2323 bool
2324 fold_convertible_p (const_tree type, const_tree arg)
2326 tree orig = TREE_TYPE (arg);
2328 if (type == orig)
2329 return true;
2331 if (TREE_CODE (arg) == ERROR_MARK
2332 || TREE_CODE (type) == ERROR_MARK
2333 || TREE_CODE (orig) == ERROR_MARK)
2334 return false;
2336 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig))
2337 return true;
2339 switch (TREE_CODE (type))
2341 case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
2342 case POINTER_TYPE: case REFERENCE_TYPE:
2343 case OFFSET_TYPE:
2344 return (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
2345 || TREE_CODE (orig) == OFFSET_TYPE);
2347 case REAL_TYPE:
2348 case FIXED_POINT_TYPE:
2349 case VECTOR_TYPE:
2350 case VOID_TYPE:
2351 return TREE_CODE (type) == TREE_CODE (orig);
2353 default:
2354 return false;
2358 /* Convert expression ARG to type TYPE. Used by the middle-end for
2359 simple conversions in preference to calling the front-end's convert. */
2361 tree
2362 fold_convert_loc (location_t loc, tree type, tree arg)
2364 tree orig = TREE_TYPE (arg);
2365 tree tem;
2367 if (type == orig)
2368 return arg;
2370 if (TREE_CODE (arg) == ERROR_MARK
2371 || TREE_CODE (type) == ERROR_MARK
2372 || TREE_CODE (orig) == ERROR_MARK)
2373 return error_mark_node;
2375 switch (TREE_CODE (type))
2377 case POINTER_TYPE:
2378 case REFERENCE_TYPE:
2379 /* Handle conversions between pointers to different address spaces. */
2380 if (POINTER_TYPE_P (orig)
2381 && (TYPE_ADDR_SPACE (TREE_TYPE (type))
2382 != TYPE_ADDR_SPACE (TREE_TYPE (orig))))
2383 return fold_build1_loc (loc, ADDR_SPACE_CONVERT_EXPR, type, arg);
2384 /* fall through */
2386 case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
2387 case OFFSET_TYPE:
2388 if (TREE_CODE (arg) == INTEGER_CST)
2390 tem = fold_convert_const (NOP_EXPR, type, arg);
2391 if (tem != NULL_TREE)
2392 return tem;
2394 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
2395 || TREE_CODE (orig) == OFFSET_TYPE)
2396 return fold_build1_loc (loc, NOP_EXPR, type, arg);
2397 if (TREE_CODE (orig) == COMPLEX_TYPE)
2398 return fold_convert_loc (loc, type,
2399 fold_build1_loc (loc, REALPART_EXPR,
2400 TREE_TYPE (orig), arg));
2401 gcc_assert (TREE_CODE (orig) == VECTOR_TYPE
2402 && tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
2403 return fold_build1_loc (loc, VIEW_CONVERT_EXPR, type, arg);
2405 case REAL_TYPE:
2406 if (TREE_CODE (arg) == INTEGER_CST)
2408 tem = fold_convert_const (FLOAT_EXPR, type, arg);
2409 if (tem != NULL_TREE)
2410 return tem;
2412 else if (TREE_CODE (arg) == REAL_CST)
2414 tem = fold_convert_const (NOP_EXPR, type, arg);
2415 if (tem != NULL_TREE)
2416 return tem;
2418 else if (TREE_CODE (arg) == FIXED_CST)
2420 tem = fold_convert_const (FIXED_CONVERT_EXPR, type, arg);
2421 if (tem != NULL_TREE)
2422 return tem;
2425 switch (TREE_CODE (orig))
2427 case INTEGER_TYPE:
2428 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
2429 case POINTER_TYPE: case REFERENCE_TYPE:
2430 return fold_build1_loc (loc, FLOAT_EXPR, type, arg);
2432 case REAL_TYPE:
2433 return fold_build1_loc (loc, NOP_EXPR, type, arg);
2435 case FIXED_POINT_TYPE:
2436 return fold_build1_loc (loc, FIXED_CONVERT_EXPR, type, arg);
2438 case COMPLEX_TYPE:
2439 tem = fold_build1_loc (loc, REALPART_EXPR, TREE_TYPE (orig), arg);
2440 return fold_convert_loc (loc, type, tem);
2442 default:
2443 gcc_unreachable ();
2446 case FIXED_POINT_TYPE:
2447 if (TREE_CODE (arg) == FIXED_CST || TREE_CODE (arg) == INTEGER_CST
2448 || TREE_CODE (arg) == REAL_CST)
2450 tem = fold_convert_const (FIXED_CONVERT_EXPR, type, arg);
2451 if (tem != NULL_TREE)
2452 goto fold_convert_exit;
2455 switch (TREE_CODE (orig))
2457 case FIXED_POINT_TYPE:
2458 case INTEGER_TYPE:
2459 case ENUMERAL_TYPE:
2460 case BOOLEAN_TYPE:
2461 case REAL_TYPE:
2462 return fold_build1_loc (loc, FIXED_CONVERT_EXPR, type, arg);
2464 case COMPLEX_TYPE:
2465 tem = fold_build1_loc (loc, REALPART_EXPR, TREE_TYPE (orig), arg);
2466 return fold_convert_loc (loc, type, tem);
2468 default:
2469 gcc_unreachable ();
2472 case COMPLEX_TYPE:
2473 switch (TREE_CODE (orig))
2475 case INTEGER_TYPE:
2476 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
2477 case POINTER_TYPE: case REFERENCE_TYPE:
2478 case REAL_TYPE:
2479 case FIXED_POINT_TYPE:
2480 return fold_build2_loc (loc, COMPLEX_EXPR, type,
2481 fold_convert_loc (loc, TREE_TYPE (type), arg),
2482 fold_convert_loc (loc, TREE_TYPE (type),
2483 integer_zero_node));
2484 case COMPLEX_TYPE:
2486 tree rpart, ipart;
2488 if (TREE_CODE (arg) == COMPLEX_EXPR)
2490 rpart = fold_convert_loc (loc, TREE_TYPE (type),
2491 TREE_OPERAND (arg, 0));
2492 ipart = fold_convert_loc (loc, TREE_TYPE (type),
2493 TREE_OPERAND (arg, 1));
2494 return fold_build2_loc (loc, COMPLEX_EXPR, type, rpart, ipart);
2497 arg = save_expr (arg);
2498 rpart = fold_build1_loc (loc, REALPART_EXPR, TREE_TYPE (orig), arg);
2499 ipart = fold_build1_loc (loc, IMAGPART_EXPR, TREE_TYPE (orig), arg);
2500 rpart = fold_convert_loc (loc, TREE_TYPE (type), rpart);
2501 ipart = fold_convert_loc (loc, TREE_TYPE (type), ipart);
2502 return fold_build2_loc (loc, COMPLEX_EXPR, type, rpart, ipart);
2505 default:
2506 gcc_unreachable ();
2509 case VECTOR_TYPE:
2510 if (integer_zerop (arg))
2511 return build_zero_vector (type);
2512 gcc_assert (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
2513 gcc_assert (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
2514 || TREE_CODE (orig) == VECTOR_TYPE);
2515 return fold_build1_loc (loc, VIEW_CONVERT_EXPR, type, arg);
2517 case VOID_TYPE:
2518 tem = fold_ignored_result (arg);
2519 return fold_build1_loc (loc, NOP_EXPR, type, tem);
2521 default:
2522 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig))
2523 return fold_build1_loc (loc, NOP_EXPR, type, arg);
2524 gcc_unreachable ();
2526 fold_convert_exit:
2527 protected_set_expr_location_unshare (tem, loc);
2528 return tem;
2531 /* Return false if expr can be assumed not to be an lvalue, true
2532 otherwise. */
2534 static bool
2535 maybe_lvalue_p (const_tree x)
2537 /* We only need to wrap lvalue tree codes. */
2538 switch (TREE_CODE (x))
2540 case VAR_DECL:
2541 case PARM_DECL:
2542 case RESULT_DECL:
2543 case LABEL_DECL:
2544 case FUNCTION_DECL:
2545 case SSA_NAME:
2547 case COMPONENT_REF:
2548 case MEM_REF:
2549 case INDIRECT_REF:
2550 case ARRAY_REF:
2551 case ARRAY_RANGE_REF:
2552 case BIT_FIELD_REF:
2553 case OBJ_TYPE_REF:
2555 case REALPART_EXPR:
2556 case IMAGPART_EXPR:
2557 case PREINCREMENT_EXPR:
2558 case PREDECREMENT_EXPR:
2559 case SAVE_EXPR:
2560 case TRY_CATCH_EXPR:
2561 case WITH_CLEANUP_EXPR:
2562 case COMPOUND_EXPR:
2563 case MODIFY_EXPR:
2564 case TARGET_EXPR:
2565 case COND_EXPR:
2566 case BIND_EXPR:
2567 break;
2569 default:
2570 /* Assume the worst for front-end tree codes. */
2571 if ((int)TREE_CODE (x) >= NUM_TREE_CODES)
2572 break;
2573 return false;
2576 return true;
2579 /* Return an expr equal to X but certainly not valid as an lvalue. */
2581 tree
2582 non_lvalue_loc (location_t loc, tree x)
2584 /* While we are in GIMPLE, NON_LVALUE_EXPR doesn't mean anything to
2585 us. */
2586 if (in_gimple_form)
2587 return x;
2589 if (! maybe_lvalue_p (x))
2590 return x;
2591 return build1_loc (loc, NON_LVALUE_EXPR, TREE_TYPE (x), x);
2594 /* When pedantic, return an expr equal to X but certainly not valid as a
2595 pedantic lvalue. Otherwise, return X. */
2597 static tree
2598 pedantic_non_lvalue_loc (location_t loc, tree x)
2600 return protected_set_expr_location_unshare (x, loc);
2603 /* Given a tree comparison code, return the code that is the logical inverse.
2604 It is generally not safe to do this for floating-point comparisons, except
2605 for EQ_EXPR, NE_EXPR, ORDERED_EXPR and UNORDERED_EXPR, so we return
2606 ERROR_MARK in this case. */
2608 enum tree_code
2609 invert_tree_comparison (enum tree_code code, bool honor_nans)
2611 if (honor_nans && flag_trapping_math && code != EQ_EXPR && code != NE_EXPR
2612 && code != ORDERED_EXPR && code != UNORDERED_EXPR)
2613 return ERROR_MARK;
2615 switch (code)
2617 case EQ_EXPR:
2618 return NE_EXPR;
2619 case NE_EXPR:
2620 return EQ_EXPR;
2621 case GT_EXPR:
2622 return honor_nans ? UNLE_EXPR : LE_EXPR;
2623 case GE_EXPR:
2624 return honor_nans ? UNLT_EXPR : LT_EXPR;
2625 case LT_EXPR:
2626 return honor_nans ? UNGE_EXPR : GE_EXPR;
2627 case LE_EXPR:
2628 return honor_nans ? UNGT_EXPR : GT_EXPR;
2629 case LTGT_EXPR:
2630 return UNEQ_EXPR;
2631 case UNEQ_EXPR:
2632 return LTGT_EXPR;
2633 case UNGT_EXPR:
2634 return LE_EXPR;
2635 case UNGE_EXPR:
2636 return LT_EXPR;
2637 case UNLT_EXPR:
2638 return GE_EXPR;
2639 case UNLE_EXPR:
2640 return GT_EXPR;
2641 case ORDERED_EXPR:
2642 return UNORDERED_EXPR;
2643 case UNORDERED_EXPR:
2644 return ORDERED_EXPR;
2645 default:
2646 gcc_unreachable ();
2650 /* Similar, but return the comparison that results if the operands are
2651 swapped. This is safe for floating-point. */
2653 enum tree_code
2654 swap_tree_comparison (enum tree_code code)
2656 switch (code)
2658 case EQ_EXPR:
2659 case NE_EXPR:
2660 case ORDERED_EXPR:
2661 case UNORDERED_EXPR:
2662 case LTGT_EXPR:
2663 case UNEQ_EXPR:
2664 return code;
2665 case GT_EXPR:
2666 return LT_EXPR;
2667 case GE_EXPR:
2668 return LE_EXPR;
2669 case LT_EXPR:
2670 return GT_EXPR;
2671 case LE_EXPR:
2672 return GE_EXPR;
2673 case UNGT_EXPR:
2674 return UNLT_EXPR;
2675 case UNGE_EXPR:
2676 return UNLE_EXPR;
2677 case UNLT_EXPR:
2678 return UNGT_EXPR;
2679 case UNLE_EXPR:
2680 return UNGE_EXPR;
2681 default:
2682 gcc_unreachable ();
2687 /* Convert a comparison tree code from an enum tree_code representation
2688 into a compcode bit-based encoding. This function is the inverse of
2689 compcode_to_comparison. */
2691 static enum comparison_code
2692 comparison_to_compcode (enum tree_code code)
2694 switch (code)
2696 case LT_EXPR:
2697 return COMPCODE_LT;
2698 case EQ_EXPR:
2699 return COMPCODE_EQ;
2700 case LE_EXPR:
2701 return COMPCODE_LE;
2702 case GT_EXPR:
2703 return COMPCODE_GT;
2704 case NE_EXPR:
2705 return COMPCODE_NE;
2706 case GE_EXPR:
2707 return COMPCODE_GE;
2708 case ORDERED_EXPR:
2709 return COMPCODE_ORD;
2710 case UNORDERED_EXPR:
2711 return COMPCODE_UNORD;
2712 case UNLT_EXPR:
2713 return COMPCODE_UNLT;
2714 case UNEQ_EXPR:
2715 return COMPCODE_UNEQ;
2716 case UNLE_EXPR:
2717 return COMPCODE_UNLE;
2718 case UNGT_EXPR:
2719 return COMPCODE_UNGT;
2720 case LTGT_EXPR:
2721 return COMPCODE_LTGT;
2722 case UNGE_EXPR:
2723 return COMPCODE_UNGE;
2724 default:
2725 gcc_unreachable ();
2729 /* Convert a compcode bit-based encoding of a comparison operator back
2730 to GCC's enum tree_code representation. This function is the
2731 inverse of comparison_to_compcode. */
2733 static enum tree_code
2734 compcode_to_comparison (enum comparison_code code)
2736 switch (code)
2738 case COMPCODE_LT:
2739 return LT_EXPR;
2740 case COMPCODE_EQ:
2741 return EQ_EXPR;
2742 case COMPCODE_LE:
2743 return LE_EXPR;
2744 case COMPCODE_GT:
2745 return GT_EXPR;
2746 case COMPCODE_NE:
2747 return NE_EXPR;
2748 case COMPCODE_GE:
2749 return GE_EXPR;
2750 case COMPCODE_ORD:
2751 return ORDERED_EXPR;
2752 case COMPCODE_UNORD:
2753 return UNORDERED_EXPR;
2754 case COMPCODE_UNLT:
2755 return UNLT_EXPR;
2756 case COMPCODE_UNEQ:
2757 return UNEQ_EXPR;
2758 case COMPCODE_UNLE:
2759 return UNLE_EXPR;
2760 case COMPCODE_UNGT:
2761 return UNGT_EXPR;
2762 case COMPCODE_LTGT:
2763 return LTGT_EXPR;
2764 case COMPCODE_UNGE:
2765 return UNGE_EXPR;
2766 default:
2767 gcc_unreachable ();
2771 /* Return a tree for the comparison which is the combination of
2772 doing the AND or OR (depending on CODE) of the two operations LCODE
2773 and RCODE on the identical operands LL_ARG and LR_ARG. Take into account
2774 the possibility of trapping if the mode has NaNs, and return NULL_TREE
2775 if this makes the transformation invalid. */
2777 tree
2778 combine_comparisons (location_t loc,
2779 enum tree_code code, enum tree_code lcode,
2780 enum tree_code rcode, tree truth_type,
2781 tree ll_arg, tree lr_arg)
2783 bool honor_nans = HONOR_NANS (ll_arg);
2784 enum comparison_code lcompcode = comparison_to_compcode (lcode);
2785 enum comparison_code rcompcode = comparison_to_compcode (rcode);
2786 int compcode;
2788 switch (code)
2790 case TRUTH_AND_EXPR: case TRUTH_ANDIF_EXPR:
2791 compcode = lcompcode & rcompcode;
2792 break;
2794 case TRUTH_OR_EXPR: case TRUTH_ORIF_EXPR:
2795 compcode = lcompcode | rcompcode;
2796 break;
2798 default:
2799 return NULL_TREE;
2802 if (!honor_nans)
2804 /* Eliminate unordered comparisons, as well as LTGT and ORD
2805 which are not used unless the mode has NaNs. */
2806 compcode &= ~COMPCODE_UNORD;
2807 if (compcode == COMPCODE_LTGT)
2808 compcode = COMPCODE_NE;
2809 else if (compcode == COMPCODE_ORD)
2810 compcode = COMPCODE_TRUE;
2812 else if (flag_trapping_math)
2814 /* Check that the original operation and the optimized ones will trap
2815 under the same condition. */
2816 bool ltrap = (lcompcode & COMPCODE_UNORD) == 0
2817 && (lcompcode != COMPCODE_EQ)
2818 && (lcompcode != COMPCODE_ORD);
2819 bool rtrap = (rcompcode & COMPCODE_UNORD) == 0
2820 && (rcompcode != COMPCODE_EQ)
2821 && (rcompcode != COMPCODE_ORD);
2822 bool trap = (compcode & COMPCODE_UNORD) == 0
2823 && (compcode != COMPCODE_EQ)
2824 && (compcode != COMPCODE_ORD);
2826 /* In a short-circuited boolean expression the LHS might be
2827 such that the RHS, if evaluated, will never trap. For
2828 example, in ORD (x, y) && (x < y), we evaluate the RHS only
2829 if neither x nor y is NaN. (This is a mixed blessing: for
2830 example, the expression above will never trap, hence
2831 optimizing it to x < y would be invalid). */
2832 if ((code == TRUTH_ORIF_EXPR && (lcompcode & COMPCODE_UNORD))
2833 || (code == TRUTH_ANDIF_EXPR && !(lcompcode & COMPCODE_UNORD)))
2834 rtrap = false;
2836 /* If the comparison was short-circuited, and only the RHS
2837 trapped, we may now generate a spurious trap. */
2838 if (rtrap && !ltrap
2839 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2840 return NULL_TREE;
2842 /* If we changed the conditions that cause a trap, we lose. */
2843 if ((ltrap || rtrap) != trap)
2844 return NULL_TREE;
2847 if (compcode == COMPCODE_TRUE)
2848 return constant_boolean_node (true, truth_type);
2849 else if (compcode == COMPCODE_FALSE)
2850 return constant_boolean_node (false, truth_type);
2851 else
2853 enum tree_code tcode;
2855 tcode = compcode_to_comparison ((enum comparison_code) compcode);
2856 return fold_build2_loc (loc, tcode, truth_type, ll_arg, lr_arg);
2860 /* Return nonzero if two operands (typically of the same tree node)
2861 are necessarily equal. FLAGS modifies behavior as follows:
2863 If OEP_ONLY_CONST is set, only return nonzero for constants.
2864 This function tests whether the operands are indistinguishable;
2865 it does not test whether they are equal using C's == operation.
2866 The distinction is important for IEEE floating point, because
2867 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2868 (2) two NaNs may be indistinguishable, but NaN!=NaN.
2870 If OEP_ONLY_CONST is unset, a VAR_DECL is considered equal to itself
2871 even though it may hold multiple values during a function.
2872 This is because a GCC tree node guarantees that nothing else is
2873 executed between the evaluation of its "operands" (which may often
2874 be evaluated in arbitrary order). Hence if the operands themselves
2875 don't side-effect, the VAR_DECLs, PARM_DECLs etc... must hold the
2876 same value in each operand/subexpression. Hence leaving OEP_ONLY_CONST
2877 unset means assuming isochronic (or instantaneous) tree equivalence.
2878 Unless comparing arbitrary expression trees, such as from different
2879 statements, this flag can usually be left unset.
2881 If OEP_PURE_SAME is set, then pure functions with identical arguments
2882 are considered the same. It is used when the caller has other ways
2883 to ensure that global memory is unchanged in between.
2885 If OEP_ADDRESS_OF is set, we are actually comparing addresses of objects,
2886 not values of expressions.
2888 If OEP_LEXICOGRAPHIC is set, then also handle expressions with side-effects
2889 such as MODIFY_EXPR, RETURN_EXPR, as well as STATEMENT_LISTs.
2891 Unless OEP_MATCH_SIDE_EFFECTS is set, the function returns false on
2892 any operand with side effect. This is unnecesarily conservative in the
2893 case we know that arg0 and arg1 are in disjoint code paths (such as in
2894 ?: operator). In addition OEP_MATCH_SIDE_EFFECTS is used when comparing
2895 addresses with TREE_CONSTANT flag set so we know that &var == &var
2896 even if var is volatile. */
2899 operand_equal_p (const_tree arg0, const_tree arg1, unsigned int flags)
2901 /* When checking, verify at the outermost operand_equal_p call that
2902 if operand_equal_p returns non-zero then ARG0 and ARG1 has the same
2903 hash value. */
2904 if (flag_checking && !(flags & OEP_NO_HASH_CHECK))
2906 if (operand_equal_p (arg0, arg1, flags | OEP_NO_HASH_CHECK))
2908 if (arg0 != arg1)
2910 inchash::hash hstate0 (0), hstate1 (0);
2911 inchash::add_expr (arg0, hstate0, flags | OEP_HASH_CHECK);
2912 inchash::add_expr (arg1, hstate1, flags | OEP_HASH_CHECK);
2913 hashval_t h0 = hstate0.end ();
2914 hashval_t h1 = hstate1.end ();
2915 gcc_assert (h0 == h1);
2917 return 1;
2919 else
2920 return 0;
2923 /* If either is ERROR_MARK, they aren't equal. */
2924 if (TREE_CODE (arg0) == ERROR_MARK || TREE_CODE (arg1) == ERROR_MARK
2925 || TREE_TYPE (arg0) == error_mark_node
2926 || TREE_TYPE (arg1) == error_mark_node)
2927 return 0;
2929 /* Similar, if either does not have a type (like a released SSA name),
2930 they aren't equal. */
2931 if (!TREE_TYPE (arg0) || !TREE_TYPE (arg1))
2932 return 0;
2934 /* We cannot consider pointers to different address space equal. */
2935 if (POINTER_TYPE_P (TREE_TYPE (arg0))
2936 && POINTER_TYPE_P (TREE_TYPE (arg1))
2937 && (TYPE_ADDR_SPACE (TREE_TYPE (TREE_TYPE (arg0)))
2938 != TYPE_ADDR_SPACE (TREE_TYPE (TREE_TYPE (arg1)))))
2939 return 0;
2941 /* Check equality of integer constants before bailing out due to
2942 precision differences. */
2943 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
2945 /* Address of INTEGER_CST is not defined; check that we did not forget
2946 to drop the OEP_ADDRESS_OF flags. */
2947 gcc_checking_assert (!(flags & OEP_ADDRESS_OF));
2948 return tree_int_cst_equal (arg0, arg1);
2951 if (!(flags & OEP_ADDRESS_OF))
2953 /* If both types don't have the same signedness, then we can't consider
2954 them equal. We must check this before the STRIP_NOPS calls
2955 because they may change the signedness of the arguments. As pointers
2956 strictly don't have a signedness, require either two pointers or
2957 two non-pointers as well. */
2958 if (TYPE_UNSIGNED (TREE_TYPE (arg0)) != TYPE_UNSIGNED (TREE_TYPE (arg1))
2959 || POINTER_TYPE_P (TREE_TYPE (arg0))
2960 != POINTER_TYPE_P (TREE_TYPE (arg1)))
2961 return 0;
2963 /* If both types don't have the same precision, then it is not safe
2964 to strip NOPs. */
2965 if (element_precision (TREE_TYPE (arg0))
2966 != element_precision (TREE_TYPE (arg1)))
2967 return 0;
2969 STRIP_NOPS (arg0);
2970 STRIP_NOPS (arg1);
2972 #if 0
2973 /* FIXME: Fortran FE currently produce ADDR_EXPR of NOP_EXPR. Enable the
2974 sanity check once the issue is solved. */
2975 else
2976 /* Addresses of conversions and SSA_NAMEs (and many other things)
2977 are not defined. Check that we did not forget to drop the
2978 OEP_ADDRESS_OF/OEP_CONSTANT_ADDRESS_OF flags. */
2979 gcc_checking_assert (!CONVERT_EXPR_P (arg0) && !CONVERT_EXPR_P (arg1)
2980 && TREE_CODE (arg0) != SSA_NAME);
2981 #endif
2983 /* In case both args are comparisons but with different comparison
2984 code, try to swap the comparison operands of one arg to produce
2985 a match and compare that variant. */
2986 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2987 && COMPARISON_CLASS_P (arg0)
2988 && COMPARISON_CLASS_P (arg1))
2990 enum tree_code swap_code = swap_tree_comparison (TREE_CODE (arg1));
2992 if (TREE_CODE (arg0) == swap_code)
2993 return operand_equal_p (TREE_OPERAND (arg0, 0),
2994 TREE_OPERAND (arg1, 1), flags)
2995 && operand_equal_p (TREE_OPERAND (arg0, 1),
2996 TREE_OPERAND (arg1, 0), flags);
2999 if (TREE_CODE (arg0) != TREE_CODE (arg1))
3001 /* NOP_EXPR and CONVERT_EXPR are considered equal. */
3002 if (CONVERT_EXPR_P (arg0) && CONVERT_EXPR_P (arg1))
3004 else if (flags & OEP_ADDRESS_OF)
3006 /* If we are interested in comparing addresses ignore
3007 MEM_REF wrappings of the base that can appear just for
3008 TBAA reasons. */
3009 if (TREE_CODE (arg0) == MEM_REF
3010 && DECL_P (arg1)
3011 && TREE_CODE (TREE_OPERAND (arg0, 0)) == ADDR_EXPR
3012 && TREE_OPERAND (TREE_OPERAND (arg0, 0), 0) == arg1
3013 && integer_zerop (TREE_OPERAND (arg0, 1)))
3014 return 1;
3015 else if (TREE_CODE (arg1) == MEM_REF
3016 && DECL_P (arg0)
3017 && TREE_CODE (TREE_OPERAND (arg1, 0)) == ADDR_EXPR
3018 && TREE_OPERAND (TREE_OPERAND (arg1, 0), 0) == arg0
3019 && integer_zerop (TREE_OPERAND (arg1, 1)))
3020 return 1;
3021 return 0;
3023 else
3024 return 0;
3027 /* When not checking adddresses, this is needed for conversions and for
3028 COMPONENT_REF. Might as well play it safe and always test this. */
3029 if (TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
3030 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
3031 || (TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1))
3032 && !(flags & OEP_ADDRESS_OF)))
3033 return 0;
3035 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
3036 We don't care about side effects in that case because the SAVE_EXPR
3037 takes care of that for us. In all other cases, two expressions are
3038 equal if they have no side effects. If we have two identical
3039 expressions with side effects that should be treated the same due
3040 to the only side effects being identical SAVE_EXPR's, that will
3041 be detected in the recursive calls below.
3042 If we are taking an invariant address of two identical objects
3043 they are necessarily equal as well. */
3044 if (arg0 == arg1 && ! (flags & OEP_ONLY_CONST)
3045 && (TREE_CODE (arg0) == SAVE_EXPR
3046 || (flags & OEP_MATCH_SIDE_EFFECTS)
3047 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
3048 return 1;
3050 /* Next handle constant cases, those for which we can return 1 even
3051 if ONLY_CONST is set. */
3052 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
3053 switch (TREE_CODE (arg0))
3055 case INTEGER_CST:
3056 return tree_int_cst_equal (arg0, arg1);
3058 case FIXED_CST:
3059 return FIXED_VALUES_IDENTICAL (TREE_FIXED_CST (arg0),
3060 TREE_FIXED_CST (arg1));
3062 case REAL_CST:
3063 if (real_identical (&TREE_REAL_CST (arg0), &TREE_REAL_CST (arg1)))
3064 return 1;
3067 if (!HONOR_SIGNED_ZEROS (arg0))
3069 /* If we do not distinguish between signed and unsigned zero,
3070 consider them equal. */
3071 if (real_zerop (arg0) && real_zerop (arg1))
3072 return 1;
3074 return 0;
3076 case VECTOR_CST:
3078 if (VECTOR_CST_LOG2_NPATTERNS (arg0)
3079 != VECTOR_CST_LOG2_NPATTERNS (arg1))
3080 return 0;
3082 if (VECTOR_CST_NELTS_PER_PATTERN (arg0)
3083 != VECTOR_CST_NELTS_PER_PATTERN (arg1))
3084 return 0;
3086 unsigned int count = vector_cst_encoded_nelts (arg0);
3087 for (unsigned int i = 0; i < count; ++i)
3088 if (!operand_equal_p (VECTOR_CST_ENCODED_ELT (arg0, i),
3089 VECTOR_CST_ENCODED_ELT (arg1, i), flags))
3090 return 0;
3091 return 1;
3094 case COMPLEX_CST:
3095 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
3096 flags)
3097 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
3098 flags));
3100 case STRING_CST:
3101 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
3102 && ! memcmp (TREE_STRING_POINTER (arg0),
3103 TREE_STRING_POINTER (arg1),
3104 TREE_STRING_LENGTH (arg0)));
3106 case ADDR_EXPR:
3107 gcc_checking_assert (!(flags & OEP_ADDRESS_OF));
3108 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
3109 flags | OEP_ADDRESS_OF
3110 | OEP_MATCH_SIDE_EFFECTS);
3111 case CONSTRUCTOR:
3112 /* In GIMPLE empty constructors are allowed in initializers of
3113 aggregates. */
3114 return !CONSTRUCTOR_NELTS (arg0) && !CONSTRUCTOR_NELTS (arg1);
3115 default:
3116 break;
3119 if (flags & OEP_ONLY_CONST)
3120 return 0;
3122 /* Define macros to test an operand from arg0 and arg1 for equality and a
3123 variant that allows null and views null as being different from any
3124 non-null value. In the latter case, if either is null, the both
3125 must be; otherwise, do the normal comparison. */
3126 #define OP_SAME(N) operand_equal_p (TREE_OPERAND (arg0, N), \
3127 TREE_OPERAND (arg1, N), flags)
3129 #define OP_SAME_WITH_NULL(N) \
3130 ((!TREE_OPERAND (arg0, N) || !TREE_OPERAND (arg1, N)) \
3131 ? TREE_OPERAND (arg0, N) == TREE_OPERAND (arg1, N) : OP_SAME (N))
3133 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
3135 case tcc_unary:
3136 /* Two conversions are equal only if signedness and modes match. */
3137 switch (TREE_CODE (arg0))
3139 CASE_CONVERT:
3140 case FIX_TRUNC_EXPR:
3141 if (TYPE_UNSIGNED (TREE_TYPE (arg0))
3142 != TYPE_UNSIGNED (TREE_TYPE (arg1)))
3143 return 0;
3144 break;
3145 default:
3146 break;
3149 return OP_SAME (0);
3152 case tcc_comparison:
3153 case tcc_binary:
3154 if (OP_SAME (0) && OP_SAME (1))
3155 return 1;
3157 /* For commutative ops, allow the other order. */
3158 return (commutative_tree_code (TREE_CODE (arg0))
3159 && operand_equal_p (TREE_OPERAND (arg0, 0),
3160 TREE_OPERAND (arg1, 1), flags)
3161 && operand_equal_p (TREE_OPERAND (arg0, 1),
3162 TREE_OPERAND (arg1, 0), flags));
3164 case tcc_reference:
3165 /* If either of the pointer (or reference) expressions we are
3166 dereferencing contain a side effect, these cannot be equal,
3167 but their addresses can be. */
3168 if ((flags & OEP_MATCH_SIDE_EFFECTS) == 0
3169 && (TREE_SIDE_EFFECTS (arg0)
3170 || TREE_SIDE_EFFECTS (arg1)))
3171 return 0;
3173 switch (TREE_CODE (arg0))
3175 case INDIRECT_REF:
3176 if (!(flags & OEP_ADDRESS_OF)
3177 && (TYPE_ALIGN (TREE_TYPE (arg0))
3178 != TYPE_ALIGN (TREE_TYPE (arg1))))
3179 return 0;
3180 flags &= ~OEP_ADDRESS_OF;
3181 return OP_SAME (0);
3183 case IMAGPART_EXPR:
3184 /* Require the same offset. */
3185 if (!operand_equal_p (TYPE_SIZE (TREE_TYPE (arg0)),
3186 TYPE_SIZE (TREE_TYPE (arg1)),
3187 flags & ~OEP_ADDRESS_OF))
3188 return 0;
3190 /* Fallthru. */
3191 case REALPART_EXPR:
3192 case VIEW_CONVERT_EXPR:
3193 return OP_SAME (0);
3195 case TARGET_MEM_REF:
3196 case MEM_REF:
3197 if (!(flags & OEP_ADDRESS_OF))
3199 /* Require equal access sizes */
3200 if (TYPE_SIZE (TREE_TYPE (arg0)) != TYPE_SIZE (TREE_TYPE (arg1))
3201 && (!TYPE_SIZE (TREE_TYPE (arg0))
3202 || !TYPE_SIZE (TREE_TYPE (arg1))
3203 || !operand_equal_p (TYPE_SIZE (TREE_TYPE (arg0)),
3204 TYPE_SIZE (TREE_TYPE (arg1)),
3205 flags)))
3206 return 0;
3207 /* Verify that access happens in similar types. */
3208 if (!types_compatible_p (TREE_TYPE (arg0), TREE_TYPE (arg1)))
3209 return 0;
3210 /* Verify that accesses are TBAA compatible. */
3211 if (!alias_ptr_types_compatible_p
3212 (TREE_TYPE (TREE_OPERAND (arg0, 1)),
3213 TREE_TYPE (TREE_OPERAND (arg1, 1)))
3214 || (MR_DEPENDENCE_CLIQUE (arg0)
3215 != MR_DEPENDENCE_CLIQUE (arg1))
3216 || (MR_DEPENDENCE_BASE (arg0)
3217 != MR_DEPENDENCE_BASE (arg1)))
3218 return 0;
3219 /* Verify that alignment is compatible. */
3220 if (TYPE_ALIGN (TREE_TYPE (arg0))
3221 != TYPE_ALIGN (TREE_TYPE (arg1)))
3222 return 0;
3224 flags &= ~OEP_ADDRESS_OF;
3225 return (OP_SAME (0) && OP_SAME (1)
3226 /* TARGET_MEM_REF require equal extra operands. */
3227 && (TREE_CODE (arg0) != TARGET_MEM_REF
3228 || (OP_SAME_WITH_NULL (2)
3229 && OP_SAME_WITH_NULL (3)
3230 && OP_SAME_WITH_NULL (4))));
3232 case ARRAY_REF:
3233 case ARRAY_RANGE_REF:
3234 if (!OP_SAME (0))
3235 return 0;
3236 flags &= ~OEP_ADDRESS_OF;
3237 /* Compare the array index by value if it is constant first as we
3238 may have different types but same value here. */
3239 return ((tree_int_cst_equal (TREE_OPERAND (arg0, 1),
3240 TREE_OPERAND (arg1, 1))
3241 || OP_SAME (1))
3242 && OP_SAME_WITH_NULL (2)
3243 && OP_SAME_WITH_NULL (3)
3244 /* Compare low bound and element size as with OEP_ADDRESS_OF
3245 we have to account for the offset of the ref. */
3246 && (TREE_TYPE (TREE_OPERAND (arg0, 0))
3247 == TREE_TYPE (TREE_OPERAND (arg1, 0))
3248 || (operand_equal_p (array_ref_low_bound
3249 (CONST_CAST_TREE (arg0)),
3250 array_ref_low_bound
3251 (CONST_CAST_TREE (arg1)), flags)
3252 && operand_equal_p (array_ref_element_size
3253 (CONST_CAST_TREE (arg0)),
3254 array_ref_element_size
3255 (CONST_CAST_TREE (arg1)),
3256 flags))));
3258 case COMPONENT_REF:
3259 /* Handle operand 2 the same as for ARRAY_REF. Operand 0
3260 may be NULL when we're called to compare MEM_EXPRs. */
3261 if (!OP_SAME_WITH_NULL (0)
3262 || !OP_SAME (1))
3263 return 0;
3264 flags &= ~OEP_ADDRESS_OF;
3265 return OP_SAME_WITH_NULL (2);
3267 case BIT_FIELD_REF:
3268 if (!OP_SAME (0))
3269 return 0;
3270 flags &= ~OEP_ADDRESS_OF;
3271 return OP_SAME (1) && OP_SAME (2);
3273 default:
3274 return 0;
3277 case tcc_expression:
3278 switch (TREE_CODE (arg0))
3280 case ADDR_EXPR:
3281 /* Be sure we pass right ADDRESS_OF flag. */
3282 gcc_checking_assert (!(flags & OEP_ADDRESS_OF));
3283 return operand_equal_p (TREE_OPERAND (arg0, 0),
3284 TREE_OPERAND (arg1, 0),
3285 flags | OEP_ADDRESS_OF);
3287 case TRUTH_NOT_EXPR:
3288 return OP_SAME (0);
3290 case TRUTH_ANDIF_EXPR:
3291 case TRUTH_ORIF_EXPR:
3292 return OP_SAME (0) && OP_SAME (1);
3294 case FMA_EXPR:
3295 case WIDEN_MULT_PLUS_EXPR:
3296 case WIDEN_MULT_MINUS_EXPR:
3297 if (!OP_SAME (2))
3298 return 0;
3299 /* The multiplcation operands are commutative. */
3300 /* FALLTHRU */
3302 case TRUTH_AND_EXPR:
3303 case TRUTH_OR_EXPR:
3304 case TRUTH_XOR_EXPR:
3305 if (OP_SAME (0) && OP_SAME (1))
3306 return 1;
3308 /* Otherwise take into account this is a commutative operation. */
3309 return (operand_equal_p (TREE_OPERAND (arg0, 0),
3310 TREE_OPERAND (arg1, 1), flags)
3311 && operand_equal_p (TREE_OPERAND (arg0, 1),
3312 TREE_OPERAND (arg1, 0), flags));
3314 case COND_EXPR:
3315 if (! OP_SAME (1) || ! OP_SAME_WITH_NULL (2))
3316 return 0;
3317 flags &= ~OEP_ADDRESS_OF;
3318 return OP_SAME (0);
3320 case BIT_INSERT_EXPR:
3321 /* BIT_INSERT_EXPR has an implict operand as the type precision
3322 of op1. Need to check to make sure they are the same. */
3323 if (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
3324 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
3325 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 1)))
3326 != TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg1, 1))))
3327 return false;
3328 /* FALLTHRU */
3330 case VEC_COND_EXPR:
3331 case DOT_PROD_EXPR:
3332 return OP_SAME (0) && OP_SAME (1) && OP_SAME (2);
3334 case MODIFY_EXPR:
3335 case INIT_EXPR:
3336 case COMPOUND_EXPR:
3337 case PREDECREMENT_EXPR:
3338 case PREINCREMENT_EXPR:
3339 case POSTDECREMENT_EXPR:
3340 case POSTINCREMENT_EXPR:
3341 if (flags & OEP_LEXICOGRAPHIC)
3342 return OP_SAME (0) && OP_SAME (1);
3343 return 0;
3345 case CLEANUP_POINT_EXPR:
3346 case EXPR_STMT:
3347 if (flags & OEP_LEXICOGRAPHIC)
3348 return OP_SAME (0);
3349 return 0;
3351 default:
3352 return 0;
3355 case tcc_vl_exp:
3356 switch (TREE_CODE (arg0))
3358 case CALL_EXPR:
3359 if ((CALL_EXPR_FN (arg0) == NULL_TREE)
3360 != (CALL_EXPR_FN (arg1) == NULL_TREE))
3361 /* If not both CALL_EXPRs are either internal or normal function
3362 functions, then they are not equal. */
3363 return 0;
3364 else if (CALL_EXPR_FN (arg0) == NULL_TREE)
3366 /* If the CALL_EXPRs call different internal functions, then they
3367 are not equal. */
3368 if (CALL_EXPR_IFN (arg0) != CALL_EXPR_IFN (arg1))
3369 return 0;
3371 else
3373 /* If the CALL_EXPRs call different functions, then they are not
3374 equal. */
3375 if (! operand_equal_p (CALL_EXPR_FN (arg0), CALL_EXPR_FN (arg1),
3376 flags))
3377 return 0;
3380 /* FIXME: We could skip this test for OEP_MATCH_SIDE_EFFECTS. */
3382 unsigned int cef = call_expr_flags (arg0);
3383 if (flags & OEP_PURE_SAME)
3384 cef &= ECF_CONST | ECF_PURE;
3385 else
3386 cef &= ECF_CONST;
3387 if (!cef && !(flags & OEP_LEXICOGRAPHIC))
3388 return 0;
3391 /* Now see if all the arguments are the same. */
3393 const_call_expr_arg_iterator iter0, iter1;
3394 const_tree a0, a1;
3395 for (a0 = first_const_call_expr_arg (arg0, &iter0),
3396 a1 = first_const_call_expr_arg (arg1, &iter1);
3397 a0 && a1;
3398 a0 = next_const_call_expr_arg (&iter0),
3399 a1 = next_const_call_expr_arg (&iter1))
3400 if (! operand_equal_p (a0, a1, flags))
3401 return 0;
3403 /* If we get here and both argument lists are exhausted
3404 then the CALL_EXPRs are equal. */
3405 return ! (a0 || a1);
3407 default:
3408 return 0;
3411 case tcc_declaration:
3412 /* Consider __builtin_sqrt equal to sqrt. */
3413 return (TREE_CODE (arg0) == FUNCTION_DECL
3414 && DECL_BUILT_IN (arg0) && DECL_BUILT_IN (arg1)
3415 && DECL_BUILT_IN_CLASS (arg0) == DECL_BUILT_IN_CLASS (arg1)
3416 && DECL_FUNCTION_CODE (arg0) == DECL_FUNCTION_CODE (arg1));
3418 case tcc_exceptional:
3419 if (TREE_CODE (arg0) == CONSTRUCTOR)
3421 /* In GIMPLE constructors are used only to build vectors from
3422 elements. Individual elements in the constructor must be
3423 indexed in increasing order and form an initial sequence.
3425 We make no effort to compare constructors in generic.
3426 (see sem_variable::equals in ipa-icf which can do so for
3427 constants). */
3428 if (!VECTOR_TYPE_P (TREE_TYPE (arg0))
3429 || !VECTOR_TYPE_P (TREE_TYPE (arg1)))
3430 return 0;
3432 /* Be sure that vectors constructed have the same representation.
3433 We only tested element precision and modes to match.
3434 Vectors may be BLKmode and thus also check that the number of
3435 parts match. */
3436 if (maybe_ne (TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0)),
3437 TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg1))))
3438 return 0;
3440 vec<constructor_elt, va_gc> *v0 = CONSTRUCTOR_ELTS (arg0);
3441 vec<constructor_elt, va_gc> *v1 = CONSTRUCTOR_ELTS (arg1);
3442 unsigned int len = vec_safe_length (v0);
3444 if (len != vec_safe_length (v1))
3445 return 0;
3447 for (unsigned int i = 0; i < len; i++)
3449 constructor_elt *c0 = &(*v0)[i];
3450 constructor_elt *c1 = &(*v1)[i];
3452 if (!operand_equal_p (c0->value, c1->value, flags)
3453 /* In GIMPLE the indexes can be either NULL or matching i.
3454 Double check this so we won't get false
3455 positives for GENERIC. */
3456 || (c0->index
3457 && (TREE_CODE (c0->index) != INTEGER_CST
3458 || !compare_tree_int (c0->index, i)))
3459 || (c1->index
3460 && (TREE_CODE (c1->index) != INTEGER_CST
3461 || !compare_tree_int (c1->index, i))))
3462 return 0;
3464 return 1;
3466 else if (TREE_CODE (arg0) == STATEMENT_LIST
3467 && (flags & OEP_LEXICOGRAPHIC))
3469 /* Compare the STATEMENT_LISTs. */
3470 tree_stmt_iterator tsi1, tsi2;
3471 tree body1 = CONST_CAST_TREE (arg0);
3472 tree body2 = CONST_CAST_TREE (arg1);
3473 for (tsi1 = tsi_start (body1), tsi2 = tsi_start (body2); ;
3474 tsi_next (&tsi1), tsi_next (&tsi2))
3476 /* The lists don't have the same number of statements. */
3477 if (tsi_end_p (tsi1) ^ tsi_end_p (tsi2))
3478 return 0;
3479 if (tsi_end_p (tsi1) && tsi_end_p (tsi2))
3480 return 1;
3481 if (!operand_equal_p (tsi_stmt (tsi1), tsi_stmt (tsi2),
3482 OEP_LEXICOGRAPHIC))
3483 return 0;
3486 return 0;
3488 case tcc_statement:
3489 switch (TREE_CODE (arg0))
3491 case RETURN_EXPR:
3492 if (flags & OEP_LEXICOGRAPHIC)
3493 return OP_SAME_WITH_NULL (0);
3494 return 0;
3495 default:
3496 return 0;
3499 default:
3500 return 0;
3503 #undef OP_SAME
3504 #undef OP_SAME_WITH_NULL
3507 /* Similar to operand_equal_p, but see if ARG0 might be a variant of ARG1
3508 with a different signedness or a narrower precision. */
3510 static bool
3511 operand_equal_for_comparison_p (tree arg0, tree arg1)
3513 if (operand_equal_p (arg0, arg1, 0))
3514 return true;
3516 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
3517 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
3518 return false;
3520 /* Discard any conversions that don't change the modes of ARG0 and ARG1
3521 and see if the inner values are the same. This removes any
3522 signedness comparison, which doesn't matter here. */
3523 tree op0 = arg0;
3524 tree op1 = arg1;
3525 STRIP_NOPS (op0);
3526 STRIP_NOPS (op1);
3527 if (operand_equal_p (op0, op1, 0))
3528 return true;
3530 /* Discard a single widening conversion from ARG1 and see if the inner
3531 value is the same as ARG0. */
3532 if (CONVERT_EXPR_P (arg1)
3533 && INTEGRAL_TYPE_P (TREE_TYPE (TREE_OPERAND (arg1, 0)))
3534 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg1, 0)))
3535 < TYPE_PRECISION (TREE_TYPE (arg1))
3536 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
3537 return true;
3539 return false;
3542 /* See if ARG is an expression that is either a comparison or is performing
3543 arithmetic on comparisons. The comparisons must only be comparing
3544 two different values, which will be stored in *CVAL1 and *CVAL2; if
3545 they are nonzero it means that some operands have already been found.
3546 No variables may be used anywhere else in the expression except in the
3547 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
3548 the expression and save_expr needs to be called with CVAL1 and CVAL2.
3550 If this is true, return 1. Otherwise, return zero. */
3552 static int
3553 twoval_comparison_p (tree arg, tree *cval1, tree *cval2, int *save_p)
3555 enum tree_code code = TREE_CODE (arg);
3556 enum tree_code_class tclass = TREE_CODE_CLASS (code);
3558 /* We can handle some of the tcc_expression cases here. */
3559 if (tclass == tcc_expression && code == TRUTH_NOT_EXPR)
3560 tclass = tcc_unary;
3561 else if (tclass == tcc_expression
3562 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
3563 || code == COMPOUND_EXPR))
3564 tclass = tcc_binary;
3566 else if (tclass == tcc_expression && code == SAVE_EXPR
3567 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
3569 /* If we've already found a CVAL1 or CVAL2, this expression is
3570 two complex to handle. */
3571 if (*cval1 || *cval2)
3572 return 0;
3574 tclass = tcc_unary;
3575 *save_p = 1;
3578 switch (tclass)
3580 case tcc_unary:
3581 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
3583 case tcc_binary:
3584 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
3585 && twoval_comparison_p (TREE_OPERAND (arg, 1),
3586 cval1, cval2, save_p));
3588 case tcc_constant:
3589 return 1;
3591 case tcc_expression:
3592 if (code == COND_EXPR)
3593 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
3594 cval1, cval2, save_p)
3595 && twoval_comparison_p (TREE_OPERAND (arg, 1),
3596 cval1, cval2, save_p)
3597 && twoval_comparison_p (TREE_OPERAND (arg, 2),
3598 cval1, cval2, save_p));
3599 return 0;
3601 case tcc_comparison:
3602 /* First see if we can handle the first operand, then the second. For
3603 the second operand, we know *CVAL1 can't be zero. It must be that
3604 one side of the comparison is each of the values; test for the
3605 case where this isn't true by failing if the two operands
3606 are the same. */
3608 if (operand_equal_p (TREE_OPERAND (arg, 0),
3609 TREE_OPERAND (arg, 1), 0))
3610 return 0;
3612 if (*cval1 == 0)
3613 *cval1 = TREE_OPERAND (arg, 0);
3614 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
3616 else if (*cval2 == 0)
3617 *cval2 = TREE_OPERAND (arg, 0);
3618 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
3620 else
3621 return 0;
3623 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
3625 else if (*cval2 == 0)
3626 *cval2 = TREE_OPERAND (arg, 1);
3627 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
3629 else
3630 return 0;
3632 return 1;
3634 default:
3635 return 0;
3639 /* ARG is a tree that is known to contain just arithmetic operations and
3640 comparisons. Evaluate the operations in the tree substituting NEW0 for
3641 any occurrence of OLD0 as an operand of a comparison and likewise for
3642 NEW1 and OLD1. */
3644 static tree
3645 eval_subst (location_t loc, tree arg, tree old0, tree new0,
3646 tree old1, tree new1)
3648 tree type = TREE_TYPE (arg);
3649 enum tree_code code = TREE_CODE (arg);
3650 enum tree_code_class tclass = TREE_CODE_CLASS (code);
3652 /* We can handle some of the tcc_expression cases here. */
3653 if (tclass == tcc_expression && code == TRUTH_NOT_EXPR)
3654 tclass = tcc_unary;
3655 else if (tclass == tcc_expression
3656 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
3657 tclass = tcc_binary;
3659 switch (tclass)
3661 case tcc_unary:
3662 return fold_build1_loc (loc, code, type,
3663 eval_subst (loc, TREE_OPERAND (arg, 0),
3664 old0, new0, old1, new1));
3666 case tcc_binary:
3667 return fold_build2_loc (loc, code, type,
3668 eval_subst (loc, TREE_OPERAND (arg, 0),
3669 old0, new0, old1, new1),
3670 eval_subst (loc, TREE_OPERAND (arg, 1),
3671 old0, new0, old1, new1));
3673 case tcc_expression:
3674 switch (code)
3676 case SAVE_EXPR:
3677 return eval_subst (loc, TREE_OPERAND (arg, 0), old0, new0,
3678 old1, new1);
3680 case COMPOUND_EXPR:
3681 return eval_subst (loc, TREE_OPERAND (arg, 1), old0, new0,
3682 old1, new1);
3684 case COND_EXPR:
3685 return fold_build3_loc (loc, code, type,
3686 eval_subst (loc, TREE_OPERAND (arg, 0),
3687 old0, new0, old1, new1),
3688 eval_subst (loc, TREE_OPERAND (arg, 1),
3689 old0, new0, old1, new1),
3690 eval_subst (loc, TREE_OPERAND (arg, 2),
3691 old0, new0, old1, new1));
3692 default:
3693 break;
3695 /* Fall through - ??? */
3697 case tcc_comparison:
3699 tree arg0 = TREE_OPERAND (arg, 0);
3700 tree arg1 = TREE_OPERAND (arg, 1);
3702 /* We need to check both for exact equality and tree equality. The
3703 former will be true if the operand has a side-effect. In that
3704 case, we know the operand occurred exactly once. */
3706 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
3707 arg0 = new0;
3708 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
3709 arg0 = new1;
3711 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
3712 arg1 = new0;
3713 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
3714 arg1 = new1;
3716 return fold_build2_loc (loc, code, type, arg0, arg1);
3719 default:
3720 return arg;
3724 /* Return a tree for the case when the result of an expression is RESULT
3725 converted to TYPE and OMITTED was previously an operand of the expression
3726 but is now not needed (e.g., we folded OMITTED * 0).
3728 If OMITTED has side effects, we must evaluate it. Otherwise, just do
3729 the conversion of RESULT to TYPE. */
3731 tree
3732 omit_one_operand_loc (location_t loc, tree type, tree result, tree omitted)
3734 tree t = fold_convert_loc (loc, type, result);
3736 /* If the resulting operand is an empty statement, just return the omitted
3737 statement casted to void. */
3738 if (IS_EMPTY_STMT (t) && TREE_SIDE_EFFECTS (omitted))
3739 return build1_loc (loc, NOP_EXPR, void_type_node,
3740 fold_ignored_result (omitted));
3742 if (TREE_SIDE_EFFECTS (omitted))
3743 return build2_loc (loc, COMPOUND_EXPR, type,
3744 fold_ignored_result (omitted), t);
3746 return non_lvalue_loc (loc, t);
3749 /* Return a tree for the case when the result of an expression is RESULT
3750 converted to TYPE and OMITTED1 and OMITTED2 were previously operands
3751 of the expression but are now not needed.
3753 If OMITTED1 or OMITTED2 has side effects, they must be evaluated.
3754 If both OMITTED1 and OMITTED2 have side effects, OMITTED1 is
3755 evaluated before OMITTED2. Otherwise, if neither has side effects,
3756 just do the conversion of RESULT to TYPE. */
3758 tree
3759 omit_two_operands_loc (location_t loc, tree type, tree result,
3760 tree omitted1, tree omitted2)
3762 tree t = fold_convert_loc (loc, type, result);
3764 if (TREE_SIDE_EFFECTS (omitted2))
3765 t = build2_loc (loc, COMPOUND_EXPR, type, omitted2, t);
3766 if (TREE_SIDE_EFFECTS (omitted1))
3767 t = build2_loc (loc, COMPOUND_EXPR, type, omitted1, t);
3769 return TREE_CODE (t) != COMPOUND_EXPR ? non_lvalue_loc (loc, t) : t;
3773 /* Return a simplified tree node for the truth-negation of ARG. This
3774 never alters ARG itself. We assume that ARG is an operation that
3775 returns a truth value (0 or 1).
3777 FIXME: one would think we would fold the result, but it causes
3778 problems with the dominator optimizer. */
3780 static tree
3781 fold_truth_not_expr (location_t loc, tree arg)
3783 tree type = TREE_TYPE (arg);
3784 enum tree_code code = TREE_CODE (arg);
3785 location_t loc1, loc2;
3787 /* If this is a comparison, we can simply invert it, except for
3788 floating-point non-equality comparisons, in which case we just
3789 enclose a TRUTH_NOT_EXPR around what we have. */
3791 if (TREE_CODE_CLASS (code) == tcc_comparison)
3793 tree op_type = TREE_TYPE (TREE_OPERAND (arg, 0));
3794 if (FLOAT_TYPE_P (op_type)
3795 && flag_trapping_math
3796 && code != ORDERED_EXPR && code != UNORDERED_EXPR
3797 && code != NE_EXPR && code != EQ_EXPR)
3798 return NULL_TREE;
3800 code = invert_tree_comparison (code, HONOR_NANS (op_type));
3801 if (code == ERROR_MARK)
3802 return NULL_TREE;
3804 tree ret = build2_loc (loc, code, type, TREE_OPERAND (arg, 0),
3805 TREE_OPERAND (arg, 1));
3806 if (TREE_NO_WARNING (arg))
3807 TREE_NO_WARNING (ret) = 1;
3808 return ret;
3811 switch (code)
3813 case INTEGER_CST:
3814 return constant_boolean_node (integer_zerop (arg), type);
3816 case TRUTH_AND_EXPR:
3817 loc1 = expr_location_or (TREE_OPERAND (arg, 0), loc);
3818 loc2 = expr_location_or (TREE_OPERAND (arg, 1), loc);
3819 return build2_loc (loc, TRUTH_OR_EXPR, type,
3820 invert_truthvalue_loc (loc1, TREE_OPERAND (arg, 0)),
3821 invert_truthvalue_loc (loc2, TREE_OPERAND (arg, 1)));
3823 case TRUTH_OR_EXPR:
3824 loc1 = expr_location_or (TREE_OPERAND (arg, 0), loc);
3825 loc2 = expr_location_or (TREE_OPERAND (arg, 1), loc);
3826 return build2_loc (loc, TRUTH_AND_EXPR, type,
3827 invert_truthvalue_loc (loc1, TREE_OPERAND (arg, 0)),
3828 invert_truthvalue_loc (loc2, TREE_OPERAND (arg, 1)));
3830 case TRUTH_XOR_EXPR:
3831 /* Here we can invert either operand. We invert the first operand
3832 unless the second operand is a TRUTH_NOT_EXPR in which case our
3833 result is the XOR of the first operand with the inside of the
3834 negation of the second operand. */
3836 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
3837 return build2_loc (loc, TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
3838 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
3839 else
3840 return build2_loc (loc, TRUTH_XOR_EXPR, type,
3841 invert_truthvalue_loc (loc, TREE_OPERAND (arg, 0)),
3842 TREE_OPERAND (arg, 1));
3844 case TRUTH_ANDIF_EXPR:
3845 loc1 = expr_location_or (TREE_OPERAND (arg, 0), loc);
3846 loc2 = expr_location_or (TREE_OPERAND (arg, 1), loc);
3847 return build2_loc (loc, TRUTH_ORIF_EXPR, type,
3848 invert_truthvalue_loc (loc1, TREE_OPERAND (arg, 0)),
3849 invert_truthvalue_loc (loc2, TREE_OPERAND (arg, 1)));
3851 case TRUTH_ORIF_EXPR:
3852 loc1 = expr_location_or (TREE_OPERAND (arg, 0), loc);
3853 loc2 = expr_location_or (TREE_OPERAND (arg, 1), loc);
3854 return build2_loc (loc, TRUTH_ANDIF_EXPR, type,
3855 invert_truthvalue_loc (loc1, TREE_OPERAND (arg, 0)),
3856 invert_truthvalue_loc (loc2, TREE_OPERAND (arg, 1)));
3858 case TRUTH_NOT_EXPR:
3859 return TREE_OPERAND (arg, 0);
3861 case COND_EXPR:
3863 tree arg1 = TREE_OPERAND (arg, 1);
3864 tree arg2 = TREE_OPERAND (arg, 2);
3866 loc1 = expr_location_or (TREE_OPERAND (arg, 1), loc);
3867 loc2 = expr_location_or (TREE_OPERAND (arg, 2), loc);
3869 /* A COND_EXPR may have a throw as one operand, which
3870 then has void type. Just leave void operands
3871 as they are. */
3872 return build3_loc (loc, COND_EXPR, type, TREE_OPERAND (arg, 0),
3873 VOID_TYPE_P (TREE_TYPE (arg1))
3874 ? arg1 : invert_truthvalue_loc (loc1, arg1),
3875 VOID_TYPE_P (TREE_TYPE (arg2))
3876 ? arg2 : invert_truthvalue_loc (loc2, arg2));
3879 case COMPOUND_EXPR:
3880 loc1 = expr_location_or (TREE_OPERAND (arg, 1), loc);
3881 return build2_loc (loc, COMPOUND_EXPR, type,
3882 TREE_OPERAND (arg, 0),
3883 invert_truthvalue_loc (loc1, TREE_OPERAND (arg, 1)));
3885 case NON_LVALUE_EXPR:
3886 loc1 = expr_location_or (TREE_OPERAND (arg, 0), loc);
3887 return invert_truthvalue_loc (loc1, TREE_OPERAND (arg, 0));
3889 CASE_CONVERT:
3890 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE)
3891 return build1_loc (loc, TRUTH_NOT_EXPR, type, arg);
3893 /* fall through */
3895 case FLOAT_EXPR:
3896 loc1 = expr_location_or (TREE_OPERAND (arg, 0), loc);
3897 return build1_loc (loc, TREE_CODE (arg), type,
3898 invert_truthvalue_loc (loc1, TREE_OPERAND (arg, 0)));
3900 case BIT_AND_EXPR:
3901 if (!integer_onep (TREE_OPERAND (arg, 1)))
3902 return NULL_TREE;
3903 return build2_loc (loc, EQ_EXPR, type, arg, build_int_cst (type, 0));
3905 case SAVE_EXPR:
3906 return build1_loc (loc, TRUTH_NOT_EXPR, type, arg);
3908 case CLEANUP_POINT_EXPR:
3909 loc1 = expr_location_or (TREE_OPERAND (arg, 0), loc);
3910 return build1_loc (loc, CLEANUP_POINT_EXPR, type,
3911 invert_truthvalue_loc (loc1, TREE_OPERAND (arg, 0)));
3913 default:
3914 return NULL_TREE;
3918 /* Fold the truth-negation of ARG. This never alters ARG itself. We
3919 assume that ARG is an operation that returns a truth value (0 or 1
3920 for scalars, 0 or -1 for vectors). Return the folded expression if
3921 folding is successful. Otherwise, return NULL_TREE. */
3923 static tree
3924 fold_invert_truthvalue (location_t loc, tree arg)
3926 tree type = TREE_TYPE (arg);
3927 return fold_unary_loc (loc, VECTOR_TYPE_P (type)
3928 ? BIT_NOT_EXPR
3929 : TRUTH_NOT_EXPR,
3930 type, arg);
3933 /* Return a simplified tree node for the truth-negation of ARG. This
3934 never alters ARG itself. We assume that ARG is an operation that
3935 returns a truth value (0 or 1 for scalars, 0 or -1 for vectors). */
3937 tree
3938 invert_truthvalue_loc (location_t loc, tree arg)
3940 if (TREE_CODE (arg) == ERROR_MARK)
3941 return arg;
3943 tree type = TREE_TYPE (arg);
3944 return fold_build1_loc (loc, VECTOR_TYPE_P (type)
3945 ? BIT_NOT_EXPR
3946 : TRUTH_NOT_EXPR,
3947 type, arg);
3950 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
3951 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero
3952 and uses reverse storage order if REVERSEP is nonzero. ORIG_INNER
3953 is the original memory reference used to preserve the alias set of
3954 the access. */
3956 static tree
3957 make_bit_field_ref (location_t loc, tree inner, tree orig_inner, tree type,
3958 HOST_WIDE_INT bitsize, poly_int64 bitpos,
3959 int unsignedp, int reversep)
3961 tree result, bftype;
3963 /* Attempt not to lose the access path if possible. */
3964 if (TREE_CODE (orig_inner) == COMPONENT_REF)
3966 tree ninner = TREE_OPERAND (orig_inner, 0);
3967 machine_mode nmode;
3968 poly_int64 nbitsize, nbitpos;
3969 tree noffset;
3970 int nunsignedp, nreversep, nvolatilep = 0;
3971 tree base = get_inner_reference (ninner, &nbitsize, &nbitpos,
3972 &noffset, &nmode, &nunsignedp,
3973 &nreversep, &nvolatilep);
3974 if (base == inner
3975 && noffset == NULL_TREE
3976 && known_subrange_p (bitpos, bitsize, nbitpos, nbitsize)
3977 && !reversep
3978 && !nreversep
3979 && !nvolatilep)
3981 inner = ninner;
3982 bitpos -= nbitpos;
3986 alias_set_type iset = get_alias_set (orig_inner);
3987 if (iset == 0 && get_alias_set (inner) != iset)
3988 inner = fold_build2 (MEM_REF, TREE_TYPE (inner),
3989 build_fold_addr_expr (inner),
3990 build_int_cst (ptr_type_node, 0));
3992 if (known_eq (bitpos, 0) && !reversep)
3994 tree size = TYPE_SIZE (TREE_TYPE (inner));
3995 if ((INTEGRAL_TYPE_P (TREE_TYPE (inner))
3996 || POINTER_TYPE_P (TREE_TYPE (inner)))
3997 && tree_fits_shwi_p (size)
3998 && tree_to_shwi (size) == bitsize)
3999 return fold_convert_loc (loc, type, inner);
4002 bftype = type;
4003 if (TYPE_PRECISION (bftype) != bitsize
4004 || TYPE_UNSIGNED (bftype) == !unsignedp)
4005 bftype = build_nonstandard_integer_type (bitsize, 0);
4007 result = build3_loc (loc, BIT_FIELD_REF, bftype, inner,
4008 bitsize_int (bitsize), bitsize_int (bitpos));
4009 REF_REVERSE_STORAGE_ORDER (result) = reversep;
4011 if (bftype != type)
4012 result = fold_convert_loc (loc, type, result);
4014 return result;
4017 /* Optimize a bit-field compare.
4019 There are two cases: First is a compare against a constant and the
4020 second is a comparison of two items where the fields are at the same
4021 bit position relative to the start of a chunk (byte, halfword, word)
4022 large enough to contain it. In these cases we can avoid the shift
4023 implicit in bitfield extractions.
4025 For constants, we emit a compare of the shifted constant with the
4026 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
4027 compared. For two fields at the same position, we do the ANDs with the
4028 similar mask and compare the result of the ANDs.
4030 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
4031 COMPARE_TYPE is the type of the comparison, and LHS and RHS
4032 are the left and right operands of the comparison, respectively.
4034 If the optimization described above can be done, we return the resulting
4035 tree. Otherwise we return zero. */
4037 static tree
4038 optimize_bit_field_compare (location_t loc, enum tree_code code,
4039 tree compare_type, tree lhs, tree rhs)
4041 poly_int64 plbitpos, plbitsize, rbitpos, rbitsize;
4042 HOST_WIDE_INT lbitpos, lbitsize, nbitpos, nbitsize;
4043 tree type = TREE_TYPE (lhs);
4044 tree unsigned_type;
4045 int const_p = TREE_CODE (rhs) == INTEGER_CST;
4046 machine_mode lmode, rmode;
4047 scalar_int_mode nmode;
4048 int lunsignedp, runsignedp;
4049 int lreversep, rreversep;
4050 int lvolatilep = 0, rvolatilep = 0;
4051 tree linner, rinner = NULL_TREE;
4052 tree mask;
4053 tree offset;
4055 /* Get all the information about the extractions being done. If the bit size
4056 is the same as the size of the underlying object, we aren't doing an
4057 extraction at all and so can do nothing. We also don't want to
4058 do anything if the inner expression is a PLACEHOLDER_EXPR since we
4059 then will no longer be able to replace it. */
4060 linner = get_inner_reference (lhs, &plbitsize, &plbitpos, &offset, &lmode,
4061 &lunsignedp, &lreversep, &lvolatilep);
4062 if (linner == lhs
4063 || !known_size_p (plbitsize)
4064 || !plbitsize.is_constant (&lbitsize)
4065 || !plbitpos.is_constant (&lbitpos)
4066 || known_eq (lbitsize, GET_MODE_BITSIZE (lmode))
4067 || offset != 0
4068 || TREE_CODE (linner) == PLACEHOLDER_EXPR
4069 || lvolatilep)
4070 return 0;
4072 if (const_p)
4073 rreversep = lreversep;
4074 else
4076 /* If this is not a constant, we can only do something if bit positions,
4077 sizes, signedness and storage order are the same. */
4078 rinner
4079 = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
4080 &runsignedp, &rreversep, &rvolatilep);
4082 if (rinner == rhs
4083 || maybe_ne (lbitpos, rbitpos)
4084 || maybe_ne (lbitsize, rbitsize)
4085 || lunsignedp != runsignedp
4086 || lreversep != rreversep
4087 || offset != 0
4088 || TREE_CODE (rinner) == PLACEHOLDER_EXPR
4089 || rvolatilep)
4090 return 0;
4093 /* Honor the C++ memory model and mimic what RTL expansion does. */
4094 poly_uint64 bitstart = 0;
4095 poly_uint64 bitend = 0;
4096 if (TREE_CODE (lhs) == COMPONENT_REF)
4098 get_bit_range (&bitstart, &bitend, lhs, &plbitpos, &offset);
4099 if (!plbitpos.is_constant (&lbitpos) || offset != NULL_TREE)
4100 return 0;
4103 /* See if we can find a mode to refer to this field. We should be able to,
4104 but fail if we can't. */
4105 if (!get_best_mode (lbitsize, lbitpos, bitstart, bitend,
4106 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
4107 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
4108 TYPE_ALIGN (TREE_TYPE (rinner))),
4109 BITS_PER_WORD, false, &nmode))
4110 return 0;
4112 /* Set signed and unsigned types of the precision of this mode for the
4113 shifts below. */
4114 unsigned_type = lang_hooks.types.type_for_mode (nmode, 1);
4116 /* Compute the bit position and size for the new reference and our offset
4117 within it. If the new reference is the same size as the original, we
4118 won't optimize anything, so return zero. */
4119 nbitsize = GET_MODE_BITSIZE (nmode);
4120 nbitpos = lbitpos & ~ (nbitsize - 1);
4121 lbitpos -= nbitpos;
4122 if (nbitsize == lbitsize)
4123 return 0;
4125 if (lreversep ? !BYTES_BIG_ENDIAN : BYTES_BIG_ENDIAN)
4126 lbitpos = nbitsize - lbitsize - lbitpos;
4128 /* Make the mask to be used against the extracted field. */
4129 mask = build_int_cst_type (unsigned_type, -1);
4130 mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize));
4131 mask = const_binop (RSHIFT_EXPR, mask,
4132 size_int (nbitsize - lbitsize - lbitpos));
4134 if (! const_p)
4136 if (nbitpos < 0)
4137 return 0;
4139 /* If not comparing with constant, just rework the comparison
4140 and return. */
4141 tree t1 = make_bit_field_ref (loc, linner, lhs, unsigned_type,
4142 nbitsize, nbitpos, 1, lreversep);
4143 t1 = fold_build2_loc (loc, BIT_AND_EXPR, unsigned_type, t1, mask);
4144 tree t2 = make_bit_field_ref (loc, rinner, rhs, unsigned_type,
4145 nbitsize, nbitpos, 1, rreversep);
4146 t2 = fold_build2_loc (loc, BIT_AND_EXPR, unsigned_type, t2, mask);
4147 return fold_build2_loc (loc, code, compare_type, t1, t2);
4150 /* Otherwise, we are handling the constant case. See if the constant is too
4151 big for the field. Warn and return a tree for 0 (false) if so. We do
4152 this not only for its own sake, but to avoid having to test for this
4153 error case below. If we didn't, we might generate wrong code.
4155 For unsigned fields, the constant shifted right by the field length should
4156 be all zero. For signed fields, the high-order bits should agree with
4157 the sign bit. */
4159 if (lunsignedp)
4161 if (wi::lrshift (wi::to_wide (rhs), lbitsize) != 0)
4163 warning (0, "comparison is always %d due to width of bit-field",
4164 code == NE_EXPR);
4165 return constant_boolean_node (code == NE_EXPR, compare_type);
4168 else
4170 wide_int tem = wi::arshift (wi::to_wide (rhs), lbitsize - 1);
4171 if (tem != 0 && tem != -1)
4173 warning (0, "comparison is always %d due to width of bit-field",
4174 code == NE_EXPR);
4175 return constant_boolean_node (code == NE_EXPR, compare_type);
4179 if (nbitpos < 0)
4180 return 0;
4182 /* Single-bit compares should always be against zero. */
4183 if (lbitsize == 1 && ! integer_zerop (rhs))
4185 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
4186 rhs = build_int_cst (type, 0);
4189 /* Make a new bitfield reference, shift the constant over the
4190 appropriate number of bits and mask it with the computed mask
4191 (in case this was a signed field). If we changed it, make a new one. */
4192 lhs = make_bit_field_ref (loc, linner, lhs, unsigned_type,
4193 nbitsize, nbitpos, 1, lreversep);
4195 rhs = const_binop (BIT_AND_EXPR,
4196 const_binop (LSHIFT_EXPR,
4197 fold_convert_loc (loc, unsigned_type, rhs),
4198 size_int (lbitpos)),
4199 mask);
4201 lhs = build2_loc (loc, code, compare_type,
4202 build2 (BIT_AND_EXPR, unsigned_type, lhs, mask), rhs);
4203 return lhs;
4206 /* Subroutine for fold_truth_andor_1: decode a field reference.
4208 If EXP is a comparison reference, we return the innermost reference.
4210 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
4211 set to the starting bit number.
4213 If the innermost field can be completely contained in a mode-sized
4214 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
4216 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
4217 otherwise it is not changed.
4219 *PUNSIGNEDP is set to the signedness of the field.
4221 *PREVERSEP is set to the storage order of the field.
4223 *PMASK is set to the mask used. This is either contained in a
4224 BIT_AND_EXPR or derived from the width of the field.
4226 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
4228 Return 0 if this is not a component reference or is one that we can't
4229 do anything with. */
4231 static tree
4232 decode_field_reference (location_t loc, tree *exp_, HOST_WIDE_INT *pbitsize,
4233 HOST_WIDE_INT *pbitpos, machine_mode *pmode,
4234 int *punsignedp, int *preversep, int *pvolatilep,
4235 tree *pmask, tree *pand_mask)
4237 tree exp = *exp_;
4238 tree outer_type = 0;
4239 tree and_mask = 0;
4240 tree mask, inner, offset;
4241 tree unsigned_type;
4242 unsigned int precision;
4244 /* All the optimizations using this function assume integer fields.
4245 There are problems with FP fields since the type_for_size call
4246 below can fail for, e.g., XFmode. */
4247 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
4248 return 0;
4250 /* We are interested in the bare arrangement of bits, so strip everything
4251 that doesn't affect the machine mode. However, record the type of the
4252 outermost expression if it may matter below. */
4253 if (CONVERT_EXPR_P (exp)
4254 || TREE_CODE (exp) == NON_LVALUE_EXPR)
4255 outer_type = TREE_TYPE (exp);
4256 STRIP_NOPS (exp);
4258 if (TREE_CODE (exp) == BIT_AND_EXPR)
4260 and_mask = TREE_OPERAND (exp, 1);
4261 exp = TREE_OPERAND (exp, 0);
4262 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
4263 if (TREE_CODE (and_mask) != INTEGER_CST)
4264 return 0;
4267 poly_int64 poly_bitsize, poly_bitpos;
4268 inner = get_inner_reference (exp, &poly_bitsize, &poly_bitpos, &offset,
4269 pmode, punsignedp, preversep, pvolatilep);
4270 if ((inner == exp && and_mask == 0)
4271 || !poly_bitsize.is_constant (pbitsize)
4272 || !poly_bitpos.is_constant (pbitpos)
4273 || *pbitsize < 0
4274 || offset != 0
4275 || TREE_CODE (inner) == PLACEHOLDER_EXPR
4276 /* Reject out-of-bound accesses (PR79731). */
4277 || (! AGGREGATE_TYPE_P (TREE_TYPE (inner))
4278 && compare_tree_int (TYPE_SIZE (TREE_TYPE (inner)),
4279 *pbitpos + *pbitsize) < 0))
4280 return 0;
4282 *exp_ = exp;
4284 /* If the number of bits in the reference is the same as the bitsize of
4285 the outer type, then the outer type gives the signedness. Otherwise
4286 (in case of a small bitfield) the signedness is unchanged. */
4287 if (outer_type && *pbitsize == TYPE_PRECISION (outer_type))
4288 *punsignedp = TYPE_UNSIGNED (outer_type);
4290 /* Compute the mask to access the bitfield. */
4291 unsigned_type = lang_hooks.types.type_for_size (*pbitsize, 1);
4292 precision = TYPE_PRECISION (unsigned_type);
4294 mask = build_int_cst_type (unsigned_type, -1);
4296 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize));
4297 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize));
4299 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
4300 if (and_mask != 0)
4301 mask = fold_build2_loc (loc, BIT_AND_EXPR, unsigned_type,
4302 fold_convert_loc (loc, unsigned_type, and_mask), mask);
4304 *pmask = mask;
4305 *pand_mask = and_mask;
4306 return inner;
4309 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
4310 bit positions and MASK is SIGNED. */
4312 static int
4313 all_ones_mask_p (const_tree mask, unsigned int size)
4315 tree type = TREE_TYPE (mask);
4316 unsigned int precision = TYPE_PRECISION (type);
4318 /* If this function returns true when the type of the mask is
4319 UNSIGNED, then there will be errors. In particular see
4320 gcc.c-torture/execute/990326-1.c. There does not appear to be
4321 any documentation paper trail as to why this is so. But the pre
4322 wide-int worked with that restriction and it has been preserved
4323 here. */
4324 if (size > precision || TYPE_SIGN (type) == UNSIGNED)
4325 return false;
4327 return wi::mask (size, false, precision) == wi::to_wide (mask);
4330 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
4331 represents the sign bit of EXP's type. If EXP represents a sign
4332 or zero extension, also test VAL against the unextended type.
4333 The return value is the (sub)expression whose sign bit is VAL,
4334 or NULL_TREE otherwise. */
4336 tree
4337 sign_bit_p (tree exp, const_tree val)
4339 int width;
4340 tree t;
4342 /* Tree EXP must have an integral type. */
4343 t = TREE_TYPE (exp);
4344 if (! INTEGRAL_TYPE_P (t))
4345 return NULL_TREE;
4347 /* Tree VAL must be an integer constant. */
4348 if (TREE_CODE (val) != INTEGER_CST
4349 || TREE_OVERFLOW (val))
4350 return NULL_TREE;
4352 width = TYPE_PRECISION (t);
4353 if (wi::only_sign_bit_p (wi::to_wide (val), width))
4354 return exp;
4356 /* Handle extension from a narrower type. */
4357 if (TREE_CODE (exp) == NOP_EXPR
4358 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width)
4359 return sign_bit_p (TREE_OPERAND (exp, 0), val);
4361 return NULL_TREE;
4364 /* Subroutine for fold_truth_andor_1: determine if an operand is simple enough
4365 to be evaluated unconditionally. */
4367 static int
4368 simple_operand_p (const_tree exp)
4370 /* Strip any conversions that don't change the machine mode. */
4371 STRIP_NOPS (exp);
4373 return (CONSTANT_CLASS_P (exp)
4374 || TREE_CODE (exp) == SSA_NAME
4375 || (DECL_P (exp)
4376 && ! TREE_ADDRESSABLE (exp)
4377 && ! TREE_THIS_VOLATILE (exp)
4378 && ! DECL_NONLOCAL (exp)
4379 /* Don't regard global variables as simple. They may be
4380 allocated in ways unknown to the compiler (shared memory,
4381 #pragma weak, etc). */
4382 && ! TREE_PUBLIC (exp)
4383 && ! DECL_EXTERNAL (exp)
4384 /* Weakrefs are not safe to be read, since they can be NULL.
4385 They are !TREE_PUBLIC && !DECL_EXTERNAL but still
4386 have DECL_WEAK flag set. */
4387 && (! VAR_OR_FUNCTION_DECL_P (exp) || ! DECL_WEAK (exp))
4388 /* Loading a static variable is unduly expensive, but global
4389 registers aren't expensive. */
4390 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
4393 /* Subroutine for fold_truth_andor: determine if an operand is simple enough
4394 to be evaluated unconditionally.
4395 I addition to simple_operand_p, we assume that comparisons, conversions,
4396 and logic-not operations are simple, if their operands are simple, too. */
4398 static bool
4399 simple_operand_p_2 (tree exp)
4401 enum tree_code code;
4403 if (TREE_SIDE_EFFECTS (exp)
4404 || tree_could_trap_p (exp))
4405 return false;
4407 while (CONVERT_EXPR_P (exp))
4408 exp = TREE_OPERAND (exp, 0);
4410 code = TREE_CODE (exp);
4412 if (TREE_CODE_CLASS (code) == tcc_comparison)
4413 return (simple_operand_p (TREE_OPERAND (exp, 0))
4414 && simple_operand_p (TREE_OPERAND (exp, 1)));
4416 if (code == TRUTH_NOT_EXPR)
4417 return simple_operand_p_2 (TREE_OPERAND (exp, 0));
4419 return simple_operand_p (exp);
4423 /* The following functions are subroutines to fold_range_test and allow it to
4424 try to change a logical combination of comparisons into a range test.
4426 For example, both
4427 X == 2 || X == 3 || X == 4 || X == 5
4429 X >= 2 && X <= 5
4430 are converted to
4431 (unsigned) (X - 2) <= 3
4433 We describe each set of comparisons as being either inside or outside
4434 a range, using a variable named like IN_P, and then describe the
4435 range with a lower and upper bound. If one of the bounds is omitted,
4436 it represents either the highest or lowest value of the type.
4438 In the comments below, we represent a range by two numbers in brackets
4439 preceded by a "+" to designate being inside that range, or a "-" to
4440 designate being outside that range, so the condition can be inverted by
4441 flipping the prefix. An omitted bound is represented by a "-". For
4442 example, "- [-, 10]" means being outside the range starting at the lowest
4443 possible value and ending at 10, in other words, being greater than 10.
4444 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
4445 always false.
4447 We set up things so that the missing bounds are handled in a consistent
4448 manner so neither a missing bound nor "true" and "false" need to be
4449 handled using a special case. */
4451 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
4452 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
4453 and UPPER1_P are nonzero if the respective argument is an upper bound
4454 and zero for a lower. TYPE, if nonzero, is the type of the result; it
4455 must be specified for a comparison. ARG1 will be converted to ARG0's
4456 type if both are specified. */
4458 static tree
4459 range_binop (enum tree_code code, tree type, tree arg0, int upper0_p,
4460 tree arg1, int upper1_p)
4462 tree tem;
4463 int result;
4464 int sgn0, sgn1;
4466 /* If neither arg represents infinity, do the normal operation.
4467 Else, if not a comparison, return infinity. Else handle the special
4468 comparison rules. Note that most of the cases below won't occur, but
4469 are handled for consistency. */
4471 if (arg0 != 0 && arg1 != 0)
4473 tem = fold_build2 (code, type != 0 ? type : TREE_TYPE (arg0),
4474 arg0, fold_convert (TREE_TYPE (arg0), arg1));
4475 STRIP_NOPS (tem);
4476 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
4479 if (TREE_CODE_CLASS (code) != tcc_comparison)
4480 return 0;
4482 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
4483 for neither. In real maths, we cannot assume open ended ranges are
4484 the same. But, this is computer arithmetic, where numbers are finite.
4485 We can therefore make the transformation of any unbounded range with
4486 the value Z, Z being greater than any representable number. This permits
4487 us to treat unbounded ranges as equal. */
4488 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
4489 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
4490 switch (code)
4492 case EQ_EXPR:
4493 result = sgn0 == sgn1;
4494 break;
4495 case NE_EXPR:
4496 result = sgn0 != sgn1;
4497 break;
4498 case LT_EXPR:
4499 result = sgn0 < sgn1;
4500 break;
4501 case LE_EXPR:
4502 result = sgn0 <= sgn1;
4503 break;
4504 case GT_EXPR:
4505 result = sgn0 > sgn1;
4506 break;
4507 case GE_EXPR:
4508 result = sgn0 >= sgn1;
4509 break;
4510 default:
4511 gcc_unreachable ();
4514 return constant_boolean_node (result, type);
4517 /* Helper routine for make_range. Perform one step for it, return
4518 new expression if the loop should continue or NULL_TREE if it should
4519 stop. */
4521 tree
4522 make_range_step (location_t loc, enum tree_code code, tree arg0, tree arg1,
4523 tree exp_type, tree *p_low, tree *p_high, int *p_in_p,
4524 bool *strict_overflow_p)
4526 tree arg0_type = TREE_TYPE (arg0);
4527 tree n_low, n_high, low = *p_low, high = *p_high;
4528 int in_p = *p_in_p, n_in_p;
4530 switch (code)
4532 case TRUTH_NOT_EXPR:
4533 /* We can only do something if the range is testing for zero. */
4534 if (low == NULL_TREE || high == NULL_TREE
4535 || ! integer_zerop (low) || ! integer_zerop (high))
4536 return NULL_TREE;
4537 *p_in_p = ! in_p;
4538 return arg0;
4540 case EQ_EXPR: case NE_EXPR:
4541 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
4542 /* We can only do something if the range is testing for zero
4543 and if the second operand is an integer constant. Note that
4544 saying something is "in" the range we make is done by
4545 complementing IN_P since it will set in the initial case of
4546 being not equal to zero; "out" is leaving it alone. */
4547 if (low == NULL_TREE || high == NULL_TREE
4548 || ! integer_zerop (low) || ! integer_zerop (high)
4549 || TREE_CODE (arg1) != INTEGER_CST)
4550 return NULL_TREE;
4552 switch (code)
4554 case NE_EXPR: /* - [c, c] */
4555 low = high = arg1;
4556 break;
4557 case EQ_EXPR: /* + [c, c] */
4558 in_p = ! in_p, low = high = arg1;
4559 break;
4560 case GT_EXPR: /* - [-, c] */
4561 low = 0, high = arg1;
4562 break;
4563 case GE_EXPR: /* + [c, -] */
4564 in_p = ! in_p, low = arg1, high = 0;
4565 break;
4566 case LT_EXPR: /* - [c, -] */
4567 low = arg1, high = 0;
4568 break;
4569 case LE_EXPR: /* + [-, c] */
4570 in_p = ! in_p, low = 0, high = arg1;
4571 break;
4572 default:
4573 gcc_unreachable ();
4576 /* If this is an unsigned comparison, we also know that EXP is
4577 greater than or equal to zero. We base the range tests we make
4578 on that fact, so we record it here so we can parse existing
4579 range tests. We test arg0_type since often the return type
4580 of, e.g. EQ_EXPR, is boolean. */
4581 if (TYPE_UNSIGNED (arg0_type) && (low == 0 || high == 0))
4583 if (! merge_ranges (&n_in_p, &n_low, &n_high,
4584 in_p, low, high, 1,
4585 build_int_cst (arg0_type, 0),
4586 NULL_TREE))
4587 return NULL_TREE;
4589 in_p = n_in_p, low = n_low, high = n_high;
4591 /* If the high bound is missing, but we have a nonzero low
4592 bound, reverse the range so it goes from zero to the low bound
4593 minus 1. */
4594 if (high == 0 && low && ! integer_zerop (low))
4596 in_p = ! in_p;
4597 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
4598 build_int_cst (TREE_TYPE (low), 1), 0);
4599 low = build_int_cst (arg0_type, 0);
4603 *p_low = low;
4604 *p_high = high;
4605 *p_in_p = in_p;
4606 return arg0;
4608 case NEGATE_EXPR:
4609 /* If flag_wrapv and ARG0_TYPE is signed, make sure
4610 low and high are non-NULL, then normalize will DTRT. */
4611 if (!TYPE_UNSIGNED (arg0_type)
4612 && !TYPE_OVERFLOW_UNDEFINED (arg0_type))
4614 if (low == NULL_TREE)
4615 low = TYPE_MIN_VALUE (arg0_type);
4616 if (high == NULL_TREE)
4617 high = TYPE_MAX_VALUE (arg0_type);
4620 /* (-x) IN [a,b] -> x in [-b, -a] */
4621 n_low = range_binop (MINUS_EXPR, exp_type,
4622 build_int_cst (exp_type, 0),
4623 0, high, 1);
4624 n_high = range_binop (MINUS_EXPR, exp_type,
4625 build_int_cst (exp_type, 0),
4626 0, low, 0);
4627 if (n_high != 0 && TREE_OVERFLOW (n_high))
4628 return NULL_TREE;
4629 goto normalize;
4631 case BIT_NOT_EXPR:
4632 /* ~ X -> -X - 1 */
4633 return build2_loc (loc, MINUS_EXPR, exp_type, negate_expr (arg0),
4634 build_int_cst (exp_type, 1));
4636 case PLUS_EXPR:
4637 case MINUS_EXPR:
4638 if (TREE_CODE (arg1) != INTEGER_CST)
4639 return NULL_TREE;
4641 /* If flag_wrapv and ARG0_TYPE is signed, then we cannot
4642 move a constant to the other side. */
4643 if (!TYPE_UNSIGNED (arg0_type)
4644 && !TYPE_OVERFLOW_UNDEFINED (arg0_type))
4645 return NULL_TREE;
4647 /* If EXP is signed, any overflow in the computation is undefined,
4648 so we don't worry about it so long as our computations on
4649 the bounds don't overflow. For unsigned, overflow is defined
4650 and this is exactly the right thing. */
4651 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
4652 arg0_type, low, 0, arg1, 0);
4653 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
4654 arg0_type, high, 1, arg1, 0);
4655 if ((n_low != 0 && TREE_OVERFLOW (n_low))
4656 || (n_high != 0 && TREE_OVERFLOW (n_high)))
4657 return NULL_TREE;
4659 if (TYPE_OVERFLOW_UNDEFINED (arg0_type))
4660 *strict_overflow_p = true;
4662 normalize:
4663 /* Check for an unsigned range which has wrapped around the maximum
4664 value thus making n_high < n_low, and normalize it. */
4665 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
4667 low = range_binop (PLUS_EXPR, arg0_type, n_high, 0,
4668 build_int_cst (TREE_TYPE (n_high), 1), 0);
4669 high = range_binop (MINUS_EXPR, arg0_type, n_low, 0,
4670 build_int_cst (TREE_TYPE (n_low), 1), 0);
4672 /* If the range is of the form +/- [ x+1, x ], we won't
4673 be able to normalize it. But then, it represents the
4674 whole range or the empty set, so make it
4675 +/- [ -, - ]. */
4676 if (tree_int_cst_equal (n_low, low)
4677 && tree_int_cst_equal (n_high, high))
4678 low = high = 0;
4679 else
4680 in_p = ! in_p;
4682 else
4683 low = n_low, high = n_high;
4685 *p_low = low;
4686 *p_high = high;
4687 *p_in_p = in_p;
4688 return arg0;
4690 CASE_CONVERT:
4691 case NON_LVALUE_EXPR:
4692 if (TYPE_PRECISION (arg0_type) > TYPE_PRECISION (exp_type))
4693 return NULL_TREE;
4695 if (! INTEGRAL_TYPE_P (arg0_type)
4696 || (low != 0 && ! int_fits_type_p (low, arg0_type))
4697 || (high != 0 && ! int_fits_type_p (high, arg0_type)))
4698 return NULL_TREE;
4700 n_low = low, n_high = high;
4702 if (n_low != 0)
4703 n_low = fold_convert_loc (loc, arg0_type, n_low);
4705 if (n_high != 0)
4706 n_high = fold_convert_loc (loc, arg0_type, n_high);
4708 /* If we're converting arg0 from an unsigned type, to exp,
4709 a signed type, we will be doing the comparison as unsigned.
4710 The tests above have already verified that LOW and HIGH
4711 are both positive.
4713 So we have to ensure that we will handle large unsigned
4714 values the same way that the current signed bounds treat
4715 negative values. */
4717 if (!TYPE_UNSIGNED (exp_type) && TYPE_UNSIGNED (arg0_type))
4719 tree high_positive;
4720 tree equiv_type;
4721 /* For fixed-point modes, we need to pass the saturating flag
4722 as the 2nd parameter. */
4723 if (ALL_FIXED_POINT_MODE_P (TYPE_MODE (arg0_type)))
4724 equiv_type
4725 = lang_hooks.types.type_for_mode (TYPE_MODE (arg0_type),
4726 TYPE_SATURATING (arg0_type));
4727 else
4728 equiv_type
4729 = lang_hooks.types.type_for_mode (TYPE_MODE (arg0_type), 1);
4731 /* A range without an upper bound is, naturally, unbounded.
4732 Since convert would have cropped a very large value, use
4733 the max value for the destination type. */
4734 high_positive
4735 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
4736 : TYPE_MAX_VALUE (arg0_type);
4738 if (TYPE_PRECISION (exp_type) == TYPE_PRECISION (arg0_type))
4739 high_positive = fold_build2_loc (loc, RSHIFT_EXPR, arg0_type,
4740 fold_convert_loc (loc, arg0_type,
4741 high_positive),
4742 build_int_cst (arg0_type, 1));
4744 /* If the low bound is specified, "and" the range with the
4745 range for which the original unsigned value will be
4746 positive. */
4747 if (low != 0)
4749 if (! merge_ranges (&n_in_p, &n_low, &n_high, 1, n_low, n_high,
4750 1, fold_convert_loc (loc, arg0_type,
4751 integer_zero_node),
4752 high_positive))
4753 return NULL_TREE;
4755 in_p = (n_in_p == in_p);
4757 else
4759 /* Otherwise, "or" the range with the range of the input
4760 that will be interpreted as negative. */
4761 if (! merge_ranges (&n_in_p, &n_low, &n_high, 0, n_low, n_high,
4762 1, fold_convert_loc (loc, arg0_type,
4763 integer_zero_node),
4764 high_positive))
4765 return NULL_TREE;
4767 in_p = (in_p != n_in_p);
4771 *p_low = n_low;
4772 *p_high = n_high;
4773 *p_in_p = in_p;
4774 return arg0;
4776 default:
4777 return NULL_TREE;
4781 /* Given EXP, a logical expression, set the range it is testing into
4782 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
4783 actually being tested. *PLOW and *PHIGH will be made of the same
4784 type as the returned expression. If EXP is not a comparison, we
4785 will most likely not be returning a useful value and range. Set
4786 *STRICT_OVERFLOW_P to true if the return value is only valid
4787 because signed overflow is undefined; otherwise, do not change
4788 *STRICT_OVERFLOW_P. */
4790 tree
4791 make_range (tree exp, int *pin_p, tree *plow, tree *phigh,
4792 bool *strict_overflow_p)
4794 enum tree_code code;
4795 tree arg0, arg1 = NULL_TREE;
4796 tree exp_type, nexp;
4797 int in_p;
4798 tree low, high;
4799 location_t loc = EXPR_LOCATION (exp);
4801 /* Start with simply saying "EXP != 0" and then look at the code of EXP
4802 and see if we can refine the range. Some of the cases below may not
4803 happen, but it doesn't seem worth worrying about this. We "continue"
4804 the outer loop when we've changed something; otherwise we "break"
4805 the switch, which will "break" the while. */
4807 in_p = 0;
4808 low = high = build_int_cst (TREE_TYPE (exp), 0);
4810 while (1)
4812 code = TREE_CODE (exp);
4813 exp_type = TREE_TYPE (exp);
4814 arg0 = NULL_TREE;
4816 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
4818 if (TREE_OPERAND_LENGTH (exp) > 0)
4819 arg0 = TREE_OPERAND (exp, 0);
4820 if (TREE_CODE_CLASS (code) == tcc_binary
4821 || TREE_CODE_CLASS (code) == tcc_comparison
4822 || (TREE_CODE_CLASS (code) == tcc_expression
4823 && TREE_OPERAND_LENGTH (exp) > 1))
4824 arg1 = TREE_OPERAND (exp, 1);
4826 if (arg0 == NULL_TREE)
4827 break;
4829 nexp = make_range_step (loc, code, arg0, arg1, exp_type, &low,
4830 &high, &in_p, strict_overflow_p);
4831 if (nexp == NULL_TREE)
4832 break;
4833 exp = nexp;
4836 /* If EXP is a constant, we can evaluate whether this is true or false. */
4837 if (TREE_CODE (exp) == INTEGER_CST)
4839 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
4840 exp, 0, low, 0))
4841 && integer_onep (range_binop (LE_EXPR, integer_type_node,
4842 exp, 1, high, 1)));
4843 low = high = 0;
4844 exp = 0;
4847 *pin_p = in_p, *plow = low, *phigh = high;
4848 return exp;
4851 /* Returns TRUE if [LOW, HIGH] range check can be optimized to
4852 a bitwise check i.e. when
4853 LOW == 0xXX...X00...0
4854 HIGH == 0xXX...X11...1
4855 Return corresponding mask in MASK and stem in VALUE. */
4857 static bool
4858 maskable_range_p (const_tree low, const_tree high, tree type, tree *mask,
4859 tree *value)
4861 if (TREE_CODE (low) != INTEGER_CST
4862 || TREE_CODE (high) != INTEGER_CST)
4863 return false;
4865 unsigned prec = TYPE_PRECISION (type);
4866 wide_int lo = wi::to_wide (low, prec);
4867 wide_int hi = wi::to_wide (high, prec);
4869 wide_int end_mask = lo ^ hi;
4870 if ((end_mask & (end_mask + 1)) != 0
4871 || (lo & end_mask) != 0)
4872 return false;
4874 wide_int stem_mask = ~end_mask;
4875 wide_int stem = lo & stem_mask;
4876 if (stem != (hi & stem_mask))
4877 return false;
4879 *mask = wide_int_to_tree (type, stem_mask);
4880 *value = wide_int_to_tree (type, stem);
4882 return true;
4885 /* Helper routine for build_range_check and match.pd. Return the type to
4886 perform the check or NULL if it shouldn't be optimized. */
4888 tree
4889 range_check_type (tree etype)
4891 /* First make sure that arithmetics in this type is valid, then make sure
4892 that it wraps around. */
4893 if (TREE_CODE (etype) == ENUMERAL_TYPE || TREE_CODE (etype) == BOOLEAN_TYPE)
4894 etype = lang_hooks.types.type_for_size (TYPE_PRECISION (etype),
4895 TYPE_UNSIGNED (etype));
4897 if (TREE_CODE (etype) == INTEGER_TYPE && !TYPE_OVERFLOW_WRAPS (etype))
4899 tree utype, minv, maxv;
4901 /* Check if (unsigned) INT_MAX + 1 == (unsigned) INT_MIN
4902 for the type in question, as we rely on this here. */
4903 utype = unsigned_type_for (etype);
4904 maxv = fold_convert (utype, TYPE_MAX_VALUE (etype));
4905 maxv = range_binop (PLUS_EXPR, NULL_TREE, maxv, 1,
4906 build_int_cst (TREE_TYPE (maxv), 1), 1);
4907 minv = fold_convert (utype, TYPE_MIN_VALUE (etype));
4909 if (integer_zerop (range_binop (NE_EXPR, integer_type_node,
4910 minv, 1, maxv, 1)))
4911 etype = utype;
4912 else
4913 return NULL_TREE;
4915 return etype;
4918 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
4919 type, TYPE, return an expression to test if EXP is in (or out of, depending
4920 on IN_P) the range. Return 0 if the test couldn't be created. */
4922 tree
4923 build_range_check (location_t loc, tree type, tree exp, int in_p,
4924 tree low, tree high)
4926 tree etype = TREE_TYPE (exp), mask, value;
4928 /* Disable this optimization for function pointer expressions
4929 on targets that require function pointer canonicalization. */
4930 if (targetm.have_canonicalize_funcptr_for_compare ()
4931 && TREE_CODE (etype) == POINTER_TYPE
4932 && TREE_CODE (TREE_TYPE (etype)) == FUNCTION_TYPE)
4933 return NULL_TREE;
4935 if (! in_p)
4937 value = build_range_check (loc, type, exp, 1, low, high);
4938 if (value != 0)
4939 return invert_truthvalue_loc (loc, value);
4941 return 0;
4944 if (low == 0 && high == 0)
4945 return omit_one_operand_loc (loc, type, build_int_cst (type, 1), exp);
4947 if (low == 0)
4948 return fold_build2_loc (loc, LE_EXPR, type, exp,
4949 fold_convert_loc (loc, etype, high));
4951 if (high == 0)
4952 return fold_build2_loc (loc, GE_EXPR, type, exp,
4953 fold_convert_loc (loc, etype, low));
4955 if (operand_equal_p (low, high, 0))
4956 return fold_build2_loc (loc, EQ_EXPR, type, exp,
4957 fold_convert_loc (loc, etype, low));
4959 if (TREE_CODE (exp) == BIT_AND_EXPR
4960 && maskable_range_p (low, high, etype, &mask, &value))
4961 return fold_build2_loc (loc, EQ_EXPR, type,
4962 fold_build2_loc (loc, BIT_AND_EXPR, etype,
4963 exp, mask),
4964 value);
4966 if (integer_zerop (low))
4968 if (! TYPE_UNSIGNED (etype))
4970 etype = unsigned_type_for (etype);
4971 high = fold_convert_loc (loc, etype, high);
4972 exp = fold_convert_loc (loc, etype, exp);
4974 return build_range_check (loc, type, exp, 1, 0, high);
4977 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
4978 if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST)
4980 int prec = TYPE_PRECISION (etype);
4982 if (wi::mask <widest_int> (prec - 1, false) == wi::to_widest (high))
4984 if (TYPE_UNSIGNED (etype))
4986 tree signed_etype = signed_type_for (etype);
4987 if (TYPE_PRECISION (signed_etype) != TYPE_PRECISION (etype))
4988 etype
4989 = build_nonstandard_integer_type (TYPE_PRECISION (etype), 0);
4990 else
4991 etype = signed_etype;
4992 exp = fold_convert_loc (loc, etype, exp);
4994 return fold_build2_loc (loc, GT_EXPR, type, exp,
4995 build_int_cst (etype, 0));
4999 /* Optimize (c>=low) && (c<=high) into (c-low>=0) && (c-low<=high-low).
5000 This requires wrap-around arithmetics for the type of the expression. */
5001 etype = range_check_type (etype);
5002 if (etype == NULL_TREE)
5003 return NULL_TREE;
5005 if (POINTER_TYPE_P (etype))
5006 etype = unsigned_type_for (etype);
5008 high = fold_convert_loc (loc, etype, high);
5009 low = fold_convert_loc (loc, etype, low);
5010 exp = fold_convert_loc (loc, etype, exp);
5012 value = const_binop (MINUS_EXPR, high, low);
5014 if (value != 0 && !TREE_OVERFLOW (value))
5015 return build_range_check (loc, type,
5016 fold_build2_loc (loc, MINUS_EXPR, etype, exp, low),
5017 1, build_int_cst (etype, 0), value);
5019 return 0;
5022 /* Return the predecessor of VAL in its type, handling the infinite case. */
5024 static tree
5025 range_predecessor (tree val)
5027 tree type = TREE_TYPE (val);
5029 if (INTEGRAL_TYPE_P (type)
5030 && operand_equal_p (val, TYPE_MIN_VALUE (type), 0))
5031 return 0;
5032 else
5033 return range_binop (MINUS_EXPR, NULL_TREE, val, 0,
5034 build_int_cst (TREE_TYPE (val), 1), 0);
5037 /* Return the successor of VAL in its type, handling the infinite case. */
5039 static tree
5040 range_successor (tree val)
5042 tree type = TREE_TYPE (val);
5044 if (INTEGRAL_TYPE_P (type)
5045 && operand_equal_p (val, TYPE_MAX_VALUE (type), 0))
5046 return 0;
5047 else
5048 return range_binop (PLUS_EXPR, NULL_TREE, val, 0,
5049 build_int_cst (TREE_TYPE (val), 1), 0);
5052 /* Given two ranges, see if we can merge them into one. Return 1 if we
5053 can, 0 if we can't. Set the output range into the specified parameters. */
5055 bool
5056 merge_ranges (int *pin_p, tree *plow, tree *phigh, int in0_p, tree low0,
5057 tree high0, int in1_p, tree low1, tree high1)
5059 int no_overlap;
5060 int subset;
5061 int temp;
5062 tree tem;
5063 int in_p;
5064 tree low, high;
5065 int lowequal = ((low0 == 0 && low1 == 0)
5066 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
5067 low0, 0, low1, 0)));
5068 int highequal = ((high0 == 0 && high1 == 0)
5069 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
5070 high0, 1, high1, 1)));
5072 /* Make range 0 be the range that starts first, or ends last if they
5073 start at the same value. Swap them if it isn't. */
5074 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
5075 low0, 0, low1, 0))
5076 || (lowequal
5077 && integer_onep (range_binop (GT_EXPR, integer_type_node,
5078 high1, 1, high0, 1))))
5080 temp = in0_p, in0_p = in1_p, in1_p = temp;
5081 tem = low0, low0 = low1, low1 = tem;
5082 tem = high0, high0 = high1, high1 = tem;
5085 /* Now flag two cases, whether the ranges are disjoint or whether the
5086 second range is totally subsumed in the first. Note that the tests
5087 below are simplified by the ones above. */
5088 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
5089 high0, 1, low1, 0));
5090 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
5091 high1, 1, high0, 1));
5093 /* We now have four cases, depending on whether we are including or
5094 excluding the two ranges. */
5095 if (in0_p && in1_p)
5097 /* If they don't overlap, the result is false. If the second range
5098 is a subset it is the result. Otherwise, the range is from the start
5099 of the second to the end of the first. */
5100 if (no_overlap)
5101 in_p = 0, low = high = 0;
5102 else if (subset)
5103 in_p = 1, low = low1, high = high1;
5104 else
5105 in_p = 1, low = low1, high = high0;
5108 else if (in0_p && ! in1_p)
5110 /* If they don't overlap, the result is the first range. If they are
5111 equal, the result is false. If the second range is a subset of the
5112 first, and the ranges begin at the same place, we go from just after
5113 the end of the second range to the end of the first. If the second
5114 range is not a subset of the first, or if it is a subset and both
5115 ranges end at the same place, the range starts at the start of the
5116 first range and ends just before the second range.
5117 Otherwise, we can't describe this as a single range. */
5118 if (no_overlap)
5119 in_p = 1, low = low0, high = high0;
5120 else if (lowequal && highequal)
5121 in_p = 0, low = high = 0;
5122 else if (subset && lowequal)
5124 low = range_successor (high1);
5125 high = high0;
5126 in_p = 1;
5127 if (low == 0)
5129 /* We are in the weird situation where high0 > high1 but
5130 high1 has no successor. Punt. */
5131 return 0;
5134 else if (! subset || highequal)
5136 low = low0;
5137 high = range_predecessor (low1);
5138 in_p = 1;
5139 if (high == 0)
5141 /* low0 < low1 but low1 has no predecessor. Punt. */
5142 return 0;
5145 else
5146 return 0;
5149 else if (! in0_p && in1_p)
5151 /* If they don't overlap, the result is the second range. If the second
5152 is a subset of the first, the result is false. Otherwise,
5153 the range starts just after the first range and ends at the
5154 end of the second. */
5155 if (no_overlap)
5156 in_p = 1, low = low1, high = high1;
5157 else if (subset || highequal)
5158 in_p = 0, low = high = 0;
5159 else
5161 low = range_successor (high0);
5162 high = high1;
5163 in_p = 1;
5164 if (low == 0)
5166 /* high1 > high0 but high0 has no successor. Punt. */
5167 return 0;
5172 else
5174 /* The case where we are excluding both ranges. Here the complex case
5175 is if they don't overlap. In that case, the only time we have a
5176 range is if they are adjacent. If the second is a subset of the
5177 first, the result is the first. Otherwise, the range to exclude
5178 starts at the beginning of the first range and ends at the end of the
5179 second. */
5180 if (no_overlap)
5182 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
5183 range_successor (high0),
5184 1, low1, 0)))
5185 in_p = 0, low = low0, high = high1;
5186 else
5188 /* Canonicalize - [min, x] into - [-, x]. */
5189 if (low0 && TREE_CODE (low0) == INTEGER_CST)
5190 switch (TREE_CODE (TREE_TYPE (low0)))
5192 case ENUMERAL_TYPE:
5193 if (maybe_ne (TYPE_PRECISION (TREE_TYPE (low0)),
5194 GET_MODE_BITSIZE
5195 (TYPE_MODE (TREE_TYPE (low0)))))
5196 break;
5197 /* FALLTHROUGH */
5198 case INTEGER_TYPE:
5199 if (tree_int_cst_equal (low0,
5200 TYPE_MIN_VALUE (TREE_TYPE (low0))))
5201 low0 = 0;
5202 break;
5203 case POINTER_TYPE:
5204 if (TYPE_UNSIGNED (TREE_TYPE (low0))
5205 && integer_zerop (low0))
5206 low0 = 0;
5207 break;
5208 default:
5209 break;
5212 /* Canonicalize - [x, max] into - [x, -]. */
5213 if (high1 && TREE_CODE (high1) == INTEGER_CST)
5214 switch (TREE_CODE (TREE_TYPE (high1)))
5216 case ENUMERAL_TYPE:
5217 if (maybe_ne (TYPE_PRECISION (TREE_TYPE (high1)),
5218 GET_MODE_BITSIZE
5219 (TYPE_MODE (TREE_TYPE (high1)))))
5220 break;
5221 /* FALLTHROUGH */
5222 case INTEGER_TYPE:
5223 if (tree_int_cst_equal (high1,
5224 TYPE_MAX_VALUE (TREE_TYPE (high1))))
5225 high1 = 0;
5226 break;
5227 case POINTER_TYPE:
5228 if (TYPE_UNSIGNED (TREE_TYPE (high1))
5229 && integer_zerop (range_binop (PLUS_EXPR, NULL_TREE,
5230 high1, 1,
5231 build_int_cst (TREE_TYPE (high1), 1),
5232 1)))
5233 high1 = 0;
5234 break;
5235 default:
5236 break;
5239 /* The ranges might be also adjacent between the maximum and
5240 minimum values of the given type. For
5241 - [{min,-}, x] and - [y, {max,-}] ranges where x + 1 < y
5242 return + [x + 1, y - 1]. */
5243 if (low0 == 0 && high1 == 0)
5245 low = range_successor (high0);
5246 high = range_predecessor (low1);
5247 if (low == 0 || high == 0)
5248 return 0;
5250 in_p = 1;
5252 else
5253 return 0;
5256 else if (subset)
5257 in_p = 0, low = low0, high = high0;
5258 else
5259 in_p = 0, low = low0, high = high1;
5262 *pin_p = in_p, *plow = low, *phigh = high;
5263 return 1;
5267 /* Subroutine of fold, looking inside expressions of the form
5268 A op B ? A : C, where ARG0, ARG1 and ARG2 are the three operands
5269 of the COND_EXPR. This function is being used also to optimize
5270 A op B ? C : A, by reversing the comparison first.
5272 Return a folded expression whose code is not a COND_EXPR
5273 anymore, or NULL_TREE if no folding opportunity is found. */
5275 static tree
5276 fold_cond_expr_with_comparison (location_t loc, tree type,
5277 tree arg0, tree arg1, tree arg2)
5279 enum tree_code comp_code = TREE_CODE (arg0);
5280 tree arg00 = TREE_OPERAND (arg0, 0);
5281 tree arg01 = TREE_OPERAND (arg0, 1);
5282 tree arg1_type = TREE_TYPE (arg1);
5283 tree tem;
5285 STRIP_NOPS (arg1);
5286 STRIP_NOPS (arg2);
5288 /* If we have A op 0 ? A : -A, consider applying the following
5289 transformations:
5291 A == 0? A : -A same as -A
5292 A != 0? A : -A same as A
5293 A >= 0? A : -A same as abs (A)
5294 A > 0? A : -A same as abs (A)
5295 A <= 0? A : -A same as -abs (A)
5296 A < 0? A : -A same as -abs (A)
5298 None of these transformations work for modes with signed
5299 zeros. If A is +/-0, the first two transformations will
5300 change the sign of the result (from +0 to -0, or vice
5301 versa). The last four will fix the sign of the result,
5302 even though the original expressions could be positive or
5303 negative, depending on the sign of A.
5305 Note that all these transformations are correct if A is
5306 NaN, since the two alternatives (A and -A) are also NaNs. */
5307 if (!HONOR_SIGNED_ZEROS (element_mode (type))
5308 && (FLOAT_TYPE_P (TREE_TYPE (arg01))
5309 ? real_zerop (arg01)
5310 : integer_zerop (arg01))
5311 && ((TREE_CODE (arg2) == NEGATE_EXPR
5312 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
5313 /* In the case that A is of the form X-Y, '-A' (arg2) may
5314 have already been folded to Y-X, check for that. */
5315 || (TREE_CODE (arg1) == MINUS_EXPR
5316 && TREE_CODE (arg2) == MINUS_EXPR
5317 && operand_equal_p (TREE_OPERAND (arg1, 0),
5318 TREE_OPERAND (arg2, 1), 0)
5319 && operand_equal_p (TREE_OPERAND (arg1, 1),
5320 TREE_OPERAND (arg2, 0), 0))))
5321 switch (comp_code)
5323 case EQ_EXPR:
5324 case UNEQ_EXPR:
5325 tem = fold_convert_loc (loc, arg1_type, arg1);
5326 return fold_convert_loc (loc, type, negate_expr (tem));
5327 case NE_EXPR:
5328 case LTGT_EXPR:
5329 return fold_convert_loc (loc, type, arg1);
5330 case UNGE_EXPR:
5331 case UNGT_EXPR:
5332 if (flag_trapping_math)
5333 break;
5334 /* Fall through. */
5335 case GE_EXPR:
5336 case GT_EXPR:
5337 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
5338 break;
5339 tem = fold_build1_loc (loc, ABS_EXPR, TREE_TYPE (arg1), arg1);
5340 return fold_convert_loc (loc, type, tem);
5341 case UNLE_EXPR:
5342 case UNLT_EXPR:
5343 if (flag_trapping_math)
5344 break;
5345 /* FALLTHRU */
5346 case LE_EXPR:
5347 case LT_EXPR:
5348 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
5349 break;
5350 tem = fold_build1_loc (loc, ABS_EXPR, TREE_TYPE (arg1), arg1);
5351 return negate_expr (fold_convert_loc (loc, type, tem));
5352 default:
5353 gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
5354 break;
5357 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
5358 A == 0 ? A : 0 is always 0 unless A is -0. Note that
5359 both transformations are correct when A is NaN: A != 0
5360 is then true, and A == 0 is false. */
5362 if (!HONOR_SIGNED_ZEROS (element_mode (type))
5363 && integer_zerop (arg01) && integer_zerop (arg2))
5365 if (comp_code == NE_EXPR)
5366 return fold_convert_loc (loc, type, arg1);
5367 else if (comp_code == EQ_EXPR)
5368 return build_zero_cst (type);
5371 /* Try some transformations of A op B ? A : B.
5373 A == B? A : B same as B
5374 A != B? A : B same as A
5375 A >= B? A : B same as max (A, B)
5376 A > B? A : B same as max (B, A)
5377 A <= B? A : B same as min (A, B)
5378 A < B? A : B same as min (B, A)
5380 As above, these transformations don't work in the presence
5381 of signed zeros. For example, if A and B are zeros of
5382 opposite sign, the first two transformations will change
5383 the sign of the result. In the last four, the original
5384 expressions give different results for (A=+0, B=-0) and
5385 (A=-0, B=+0), but the transformed expressions do not.
5387 The first two transformations are correct if either A or B
5388 is a NaN. In the first transformation, the condition will
5389 be false, and B will indeed be chosen. In the case of the
5390 second transformation, the condition A != B will be true,
5391 and A will be chosen.
5393 The conversions to max() and min() are not correct if B is
5394 a number and A is not. The conditions in the original
5395 expressions will be false, so all four give B. The min()
5396 and max() versions would give a NaN instead. */
5397 if (!HONOR_SIGNED_ZEROS (element_mode (type))
5398 && operand_equal_for_comparison_p (arg01, arg2)
5399 /* Avoid these transformations if the COND_EXPR may be used
5400 as an lvalue in the C++ front-end. PR c++/19199. */
5401 && (in_gimple_form
5402 || VECTOR_TYPE_P (type)
5403 || (! lang_GNU_CXX ()
5404 && strcmp (lang_hooks.name, "GNU Objective-C++") != 0)
5405 || ! maybe_lvalue_p (arg1)
5406 || ! maybe_lvalue_p (arg2)))
5408 tree comp_op0 = arg00;
5409 tree comp_op1 = arg01;
5410 tree comp_type = TREE_TYPE (comp_op0);
5412 switch (comp_code)
5414 case EQ_EXPR:
5415 return fold_convert_loc (loc, type, arg2);
5416 case NE_EXPR:
5417 return fold_convert_loc (loc, type, arg1);
5418 case LE_EXPR:
5419 case LT_EXPR:
5420 case UNLE_EXPR:
5421 case UNLT_EXPR:
5422 /* In C++ a ?: expression can be an lvalue, so put the
5423 operand which will be used if they are equal first
5424 so that we can convert this back to the
5425 corresponding COND_EXPR. */
5426 if (!HONOR_NANS (arg1))
5428 comp_op0 = fold_convert_loc (loc, comp_type, comp_op0);
5429 comp_op1 = fold_convert_loc (loc, comp_type, comp_op1);
5430 tem = (comp_code == LE_EXPR || comp_code == UNLE_EXPR)
5431 ? fold_build2_loc (loc, MIN_EXPR, comp_type, comp_op0, comp_op1)
5432 : fold_build2_loc (loc, MIN_EXPR, comp_type,
5433 comp_op1, comp_op0);
5434 return fold_convert_loc (loc, type, tem);
5436 break;
5437 case GE_EXPR:
5438 case GT_EXPR:
5439 case UNGE_EXPR:
5440 case UNGT_EXPR:
5441 if (!HONOR_NANS (arg1))
5443 comp_op0 = fold_convert_loc (loc, comp_type, comp_op0);
5444 comp_op1 = fold_convert_loc (loc, comp_type, comp_op1);
5445 tem = (comp_code == GE_EXPR || comp_code == UNGE_EXPR)
5446 ? fold_build2_loc (loc, MAX_EXPR, comp_type, comp_op0, comp_op1)
5447 : fold_build2_loc (loc, MAX_EXPR, comp_type,
5448 comp_op1, comp_op0);
5449 return fold_convert_loc (loc, type, tem);
5451 break;
5452 case UNEQ_EXPR:
5453 if (!HONOR_NANS (arg1))
5454 return fold_convert_loc (loc, type, arg2);
5455 break;
5456 case LTGT_EXPR:
5457 if (!HONOR_NANS (arg1))
5458 return fold_convert_loc (loc, type, arg1);
5459 break;
5460 default:
5461 gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
5462 break;
5466 return NULL_TREE;
5471 #ifndef LOGICAL_OP_NON_SHORT_CIRCUIT
5472 #define LOGICAL_OP_NON_SHORT_CIRCUIT \
5473 (BRANCH_COST (optimize_function_for_speed_p (cfun), \
5474 false) >= 2)
5475 #endif
5477 /* EXP is some logical combination of boolean tests. See if we can
5478 merge it into some range test. Return the new tree if so. */
5480 static tree
5481 fold_range_test (location_t loc, enum tree_code code, tree type,
5482 tree op0, tree op1)
5484 int or_op = (code == TRUTH_ORIF_EXPR
5485 || code == TRUTH_OR_EXPR);
5486 int in0_p, in1_p, in_p;
5487 tree low0, low1, low, high0, high1, high;
5488 bool strict_overflow_p = false;
5489 tree tem, lhs, rhs;
5490 const char * const warnmsg = G_("assuming signed overflow does not occur "
5491 "when simplifying range test");
5493 if (!INTEGRAL_TYPE_P (type))
5494 return 0;
5496 lhs = make_range (op0, &in0_p, &low0, &high0, &strict_overflow_p);
5497 rhs = make_range (op1, &in1_p, &low1, &high1, &strict_overflow_p);
5499 /* If this is an OR operation, invert both sides; we will invert
5500 again at the end. */
5501 if (or_op)
5502 in0_p = ! in0_p, in1_p = ! in1_p;
5504 /* If both expressions are the same, if we can merge the ranges, and we
5505 can build the range test, return it or it inverted. If one of the
5506 ranges is always true or always false, consider it to be the same
5507 expression as the other. */
5508 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
5509 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
5510 in1_p, low1, high1)
5511 && (tem = (build_range_check (loc, type,
5512 lhs != 0 ? lhs
5513 : rhs != 0 ? rhs : integer_zero_node,
5514 in_p, low, high))) != 0)
5516 if (strict_overflow_p)
5517 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
5518 return or_op ? invert_truthvalue_loc (loc, tem) : tem;
5521 /* On machines where the branch cost is expensive, if this is a
5522 short-circuited branch and the underlying object on both sides
5523 is the same, make a non-short-circuit operation. */
5524 else if (LOGICAL_OP_NON_SHORT_CIRCUIT
5525 && !flag_sanitize_coverage
5526 && lhs != 0 && rhs != 0
5527 && (code == TRUTH_ANDIF_EXPR
5528 || code == TRUTH_ORIF_EXPR)
5529 && operand_equal_p (lhs, rhs, 0))
5531 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
5532 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
5533 which cases we can't do this. */
5534 if (simple_operand_p (lhs))
5535 return build2_loc (loc, code == TRUTH_ANDIF_EXPR
5536 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
5537 type, op0, op1);
5539 else if (!lang_hooks.decls.global_bindings_p ()
5540 && !CONTAINS_PLACEHOLDER_P (lhs))
5542 tree common = save_expr (lhs);
5544 if ((lhs = build_range_check (loc, type, common,
5545 or_op ? ! in0_p : in0_p,
5546 low0, high0)) != 0
5547 && (rhs = build_range_check (loc, type, common,
5548 or_op ? ! in1_p : in1_p,
5549 low1, high1)) != 0)
5551 if (strict_overflow_p)
5552 fold_overflow_warning (warnmsg,
5553 WARN_STRICT_OVERFLOW_COMPARISON);
5554 return build2_loc (loc, code == TRUTH_ANDIF_EXPR
5555 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
5556 type, lhs, rhs);
5561 return 0;
5564 /* Subroutine for fold_truth_andor_1: C is an INTEGER_CST interpreted as a P
5565 bit value. Arrange things so the extra bits will be set to zero if and
5566 only if C is signed-extended to its full width. If MASK is nonzero,
5567 it is an INTEGER_CST that should be AND'ed with the extra bits. */
5569 static tree
5570 unextend (tree c, int p, int unsignedp, tree mask)
5572 tree type = TREE_TYPE (c);
5573 int modesize = GET_MODE_BITSIZE (SCALAR_INT_TYPE_MODE (type));
5574 tree temp;
5576 if (p == modesize || unsignedp)
5577 return c;
5579 /* We work by getting just the sign bit into the low-order bit, then
5580 into the high-order bit, then sign-extend. We then XOR that value
5581 with C. */
5582 temp = build_int_cst (TREE_TYPE (c),
5583 wi::extract_uhwi (wi::to_wide (c), p - 1, 1));
5585 /* We must use a signed type in order to get an arithmetic right shift.
5586 However, we must also avoid introducing accidental overflows, so that
5587 a subsequent call to integer_zerop will work. Hence we must
5588 do the type conversion here. At this point, the constant is either
5589 zero or one, and the conversion to a signed type can never overflow.
5590 We could get an overflow if this conversion is done anywhere else. */
5591 if (TYPE_UNSIGNED (type))
5592 temp = fold_convert (signed_type_for (type), temp);
5594 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1));
5595 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1));
5596 if (mask != 0)
5597 temp = const_binop (BIT_AND_EXPR, temp,
5598 fold_convert (TREE_TYPE (c), mask));
5599 /* If necessary, convert the type back to match the type of C. */
5600 if (TYPE_UNSIGNED (type))
5601 temp = fold_convert (type, temp);
5603 return fold_convert (type, const_binop (BIT_XOR_EXPR, c, temp));
5606 /* For an expression that has the form
5607 (A && B) || ~B
5609 (A || B) && ~B,
5610 we can drop one of the inner expressions and simplify to
5611 A || ~B
5613 A && ~B
5614 LOC is the location of the resulting expression. OP is the inner
5615 logical operation; the left-hand side in the examples above, while CMPOP
5616 is the right-hand side. RHS_ONLY is used to prevent us from accidentally
5617 removing a condition that guards another, as in
5618 (A != NULL && A->...) || A == NULL
5619 which we must not transform. If RHS_ONLY is true, only eliminate the
5620 right-most operand of the inner logical operation. */
5622 static tree
5623 merge_truthop_with_opposite_arm (location_t loc, tree op, tree cmpop,
5624 bool rhs_only)
5626 tree type = TREE_TYPE (cmpop);
5627 enum tree_code code = TREE_CODE (cmpop);
5628 enum tree_code truthop_code = TREE_CODE (op);
5629 tree lhs = TREE_OPERAND (op, 0);
5630 tree rhs = TREE_OPERAND (op, 1);
5631 tree orig_lhs = lhs, orig_rhs = rhs;
5632 enum tree_code rhs_code = TREE_CODE (rhs);
5633 enum tree_code lhs_code = TREE_CODE (lhs);
5634 enum tree_code inv_code;
5636 if (TREE_SIDE_EFFECTS (op) || TREE_SIDE_EFFECTS (cmpop))
5637 return NULL_TREE;
5639 if (TREE_CODE_CLASS (code) != tcc_comparison)
5640 return NULL_TREE;
5642 if (rhs_code == truthop_code)
5644 tree newrhs = merge_truthop_with_opposite_arm (loc, rhs, cmpop, rhs_only);
5645 if (newrhs != NULL_TREE)
5647 rhs = newrhs;
5648 rhs_code = TREE_CODE (rhs);
5651 if (lhs_code == truthop_code && !rhs_only)
5653 tree newlhs = merge_truthop_with_opposite_arm (loc, lhs, cmpop, false);
5654 if (newlhs != NULL_TREE)
5656 lhs = newlhs;
5657 lhs_code = TREE_CODE (lhs);
5661 inv_code = invert_tree_comparison (code, HONOR_NANS (type));
5662 if (inv_code == rhs_code
5663 && operand_equal_p (TREE_OPERAND (rhs, 0), TREE_OPERAND (cmpop, 0), 0)
5664 && operand_equal_p (TREE_OPERAND (rhs, 1), TREE_OPERAND (cmpop, 1), 0))
5665 return lhs;
5666 if (!rhs_only && inv_code == lhs_code
5667 && operand_equal_p (TREE_OPERAND (lhs, 0), TREE_OPERAND (cmpop, 0), 0)
5668 && operand_equal_p (TREE_OPERAND (lhs, 1), TREE_OPERAND (cmpop, 1), 0))
5669 return rhs;
5670 if (rhs != orig_rhs || lhs != orig_lhs)
5671 return fold_build2_loc (loc, truthop_code, TREE_TYPE (cmpop),
5672 lhs, rhs);
5673 return NULL_TREE;
5676 /* Find ways of folding logical expressions of LHS and RHS:
5677 Try to merge two comparisons to the same innermost item.
5678 Look for range tests like "ch >= '0' && ch <= '9'".
5679 Look for combinations of simple terms on machines with expensive branches
5680 and evaluate the RHS unconditionally.
5682 For example, if we have p->a == 2 && p->b == 4 and we can make an
5683 object large enough to span both A and B, we can do this with a comparison
5684 against the object ANDed with the a mask.
5686 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
5687 operations to do this with one comparison.
5689 We check for both normal comparisons and the BIT_AND_EXPRs made this by
5690 function and the one above.
5692 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
5693 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
5695 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
5696 two operands.
5698 We return the simplified tree or 0 if no optimization is possible. */
5700 static tree
5701 fold_truth_andor_1 (location_t loc, enum tree_code code, tree truth_type,
5702 tree lhs, tree rhs)
5704 /* If this is the "or" of two comparisons, we can do something if
5705 the comparisons are NE_EXPR. If this is the "and", we can do something
5706 if the comparisons are EQ_EXPR. I.e.,
5707 (a->b == 2 && a->c == 4) can become (a->new == NEW).
5709 WANTED_CODE is this operation code. For single bit fields, we can
5710 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
5711 comparison for one-bit fields. */
5713 enum tree_code wanted_code;
5714 enum tree_code lcode, rcode;
5715 tree ll_arg, lr_arg, rl_arg, rr_arg;
5716 tree ll_inner, lr_inner, rl_inner, rr_inner;
5717 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
5718 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
5719 HOST_WIDE_INT xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
5720 HOST_WIDE_INT lnbitsize, lnbitpos, rnbitsize, rnbitpos;
5721 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
5722 int ll_reversep, lr_reversep, rl_reversep, rr_reversep;
5723 machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
5724 scalar_int_mode lnmode, rnmode;
5725 tree ll_mask, lr_mask, rl_mask, rr_mask;
5726 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
5727 tree l_const, r_const;
5728 tree lntype, rntype, result;
5729 HOST_WIDE_INT first_bit, end_bit;
5730 int volatilep;
5732 /* Start by getting the comparison codes. Fail if anything is volatile.
5733 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
5734 it were surrounded with a NE_EXPR. */
5736 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
5737 return 0;
5739 lcode = TREE_CODE (lhs);
5740 rcode = TREE_CODE (rhs);
5742 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
5744 lhs = build2 (NE_EXPR, truth_type, lhs,
5745 build_int_cst (TREE_TYPE (lhs), 0));
5746 lcode = NE_EXPR;
5749 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
5751 rhs = build2 (NE_EXPR, truth_type, rhs,
5752 build_int_cst (TREE_TYPE (rhs), 0));
5753 rcode = NE_EXPR;
5756 if (TREE_CODE_CLASS (lcode) != tcc_comparison
5757 || TREE_CODE_CLASS (rcode) != tcc_comparison)
5758 return 0;
5760 ll_arg = TREE_OPERAND (lhs, 0);
5761 lr_arg = TREE_OPERAND (lhs, 1);
5762 rl_arg = TREE_OPERAND (rhs, 0);
5763 rr_arg = TREE_OPERAND (rhs, 1);
5765 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
5766 if (simple_operand_p (ll_arg)
5767 && simple_operand_p (lr_arg))
5769 if (operand_equal_p (ll_arg, rl_arg, 0)
5770 && operand_equal_p (lr_arg, rr_arg, 0))
5772 result = combine_comparisons (loc, code, lcode, rcode,
5773 truth_type, ll_arg, lr_arg);
5774 if (result)
5775 return result;
5777 else if (operand_equal_p (ll_arg, rr_arg, 0)
5778 && operand_equal_p (lr_arg, rl_arg, 0))
5780 result = combine_comparisons (loc, code, lcode,
5781 swap_tree_comparison (rcode),
5782 truth_type, ll_arg, lr_arg);
5783 if (result)
5784 return result;
5788 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
5789 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
5791 /* If the RHS can be evaluated unconditionally and its operands are
5792 simple, it wins to evaluate the RHS unconditionally on machines
5793 with expensive branches. In this case, this isn't a comparison
5794 that can be merged. */
5796 if (BRANCH_COST (optimize_function_for_speed_p (cfun),
5797 false) >= 2
5798 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
5799 && simple_operand_p (rl_arg)
5800 && simple_operand_p (rr_arg))
5802 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
5803 if (code == TRUTH_OR_EXPR
5804 && lcode == NE_EXPR && integer_zerop (lr_arg)
5805 && rcode == NE_EXPR && integer_zerop (rr_arg)
5806 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg)
5807 && INTEGRAL_TYPE_P (TREE_TYPE (ll_arg)))
5808 return build2_loc (loc, NE_EXPR, truth_type,
5809 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
5810 ll_arg, rl_arg),
5811 build_int_cst (TREE_TYPE (ll_arg), 0));
5813 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
5814 if (code == TRUTH_AND_EXPR
5815 && lcode == EQ_EXPR && integer_zerop (lr_arg)
5816 && rcode == EQ_EXPR && integer_zerop (rr_arg)
5817 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg)
5818 && INTEGRAL_TYPE_P (TREE_TYPE (ll_arg)))
5819 return build2_loc (loc, EQ_EXPR, truth_type,
5820 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
5821 ll_arg, rl_arg),
5822 build_int_cst (TREE_TYPE (ll_arg), 0));
5825 /* See if the comparisons can be merged. Then get all the parameters for
5826 each side. */
5828 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
5829 || (rcode != EQ_EXPR && rcode != NE_EXPR))
5830 return 0;
5832 ll_reversep = lr_reversep = rl_reversep = rr_reversep = 0;
5833 volatilep = 0;
5834 ll_inner = decode_field_reference (loc, &ll_arg,
5835 &ll_bitsize, &ll_bitpos, &ll_mode,
5836 &ll_unsignedp, &ll_reversep, &volatilep,
5837 &ll_mask, &ll_and_mask);
5838 lr_inner = decode_field_reference (loc, &lr_arg,
5839 &lr_bitsize, &lr_bitpos, &lr_mode,
5840 &lr_unsignedp, &lr_reversep, &volatilep,
5841 &lr_mask, &lr_and_mask);
5842 rl_inner = decode_field_reference (loc, &rl_arg,
5843 &rl_bitsize, &rl_bitpos, &rl_mode,
5844 &rl_unsignedp, &rl_reversep, &volatilep,
5845 &rl_mask, &rl_and_mask);
5846 rr_inner = decode_field_reference (loc, &rr_arg,
5847 &rr_bitsize, &rr_bitpos, &rr_mode,
5848 &rr_unsignedp, &rr_reversep, &volatilep,
5849 &rr_mask, &rr_and_mask);
5851 /* It must be true that the inner operation on the lhs of each
5852 comparison must be the same if we are to be able to do anything.
5853 Then see if we have constants. If not, the same must be true for
5854 the rhs's. */
5855 if (volatilep
5856 || ll_reversep != rl_reversep
5857 || ll_inner == 0 || rl_inner == 0
5858 || ! operand_equal_p (ll_inner, rl_inner, 0))
5859 return 0;
5861 if (TREE_CODE (lr_arg) == INTEGER_CST
5862 && TREE_CODE (rr_arg) == INTEGER_CST)
5864 l_const = lr_arg, r_const = rr_arg;
5865 lr_reversep = ll_reversep;
5867 else if (lr_reversep != rr_reversep
5868 || lr_inner == 0 || rr_inner == 0
5869 || ! operand_equal_p (lr_inner, rr_inner, 0))
5870 return 0;
5871 else
5872 l_const = r_const = 0;
5874 /* If either comparison code is not correct for our logical operation,
5875 fail. However, we can convert a one-bit comparison against zero into
5876 the opposite comparison against that bit being set in the field. */
5878 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
5879 if (lcode != wanted_code)
5881 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
5883 /* Make the left operand unsigned, since we are only interested
5884 in the value of one bit. Otherwise we are doing the wrong
5885 thing below. */
5886 ll_unsignedp = 1;
5887 l_const = ll_mask;
5889 else
5890 return 0;
5893 /* This is analogous to the code for l_const above. */
5894 if (rcode != wanted_code)
5896 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
5898 rl_unsignedp = 1;
5899 r_const = rl_mask;
5901 else
5902 return 0;
5905 /* See if we can find a mode that contains both fields being compared on
5906 the left. If we can't, fail. Otherwise, update all constants and masks
5907 to be relative to a field of that size. */
5908 first_bit = MIN (ll_bitpos, rl_bitpos);
5909 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
5910 if (!get_best_mode (end_bit - first_bit, first_bit, 0, 0,
5911 TYPE_ALIGN (TREE_TYPE (ll_inner)), BITS_PER_WORD,
5912 volatilep, &lnmode))
5913 return 0;
5915 lnbitsize = GET_MODE_BITSIZE (lnmode);
5916 lnbitpos = first_bit & ~ (lnbitsize - 1);
5917 lntype = lang_hooks.types.type_for_size (lnbitsize, 1);
5918 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
5920 if (ll_reversep ? !BYTES_BIG_ENDIAN : BYTES_BIG_ENDIAN)
5922 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
5923 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
5926 ll_mask = const_binop (LSHIFT_EXPR, fold_convert_loc (loc, lntype, ll_mask),
5927 size_int (xll_bitpos));
5928 rl_mask = const_binop (LSHIFT_EXPR, fold_convert_loc (loc, lntype, rl_mask),
5929 size_int (xrl_bitpos));
5931 if (l_const)
5933 l_const = fold_convert_loc (loc, lntype, l_const);
5934 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
5935 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos));
5936 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
5937 fold_build1_loc (loc, BIT_NOT_EXPR,
5938 lntype, ll_mask))))
5940 warning (0, "comparison is always %d", wanted_code == NE_EXPR);
5942 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
5945 if (r_const)
5947 r_const = fold_convert_loc (loc, lntype, r_const);
5948 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
5949 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos));
5950 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
5951 fold_build1_loc (loc, BIT_NOT_EXPR,
5952 lntype, rl_mask))))
5954 warning (0, "comparison is always %d", wanted_code == NE_EXPR);
5956 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
5960 /* If the right sides are not constant, do the same for it. Also,
5961 disallow this optimization if a size or signedness mismatch occurs
5962 between the left and right sides. */
5963 if (l_const == 0)
5965 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
5966 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
5967 /* Make sure the two fields on the right
5968 correspond to the left without being swapped. */
5969 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
5970 return 0;
5972 first_bit = MIN (lr_bitpos, rr_bitpos);
5973 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
5974 if (!get_best_mode (end_bit - first_bit, first_bit, 0, 0,
5975 TYPE_ALIGN (TREE_TYPE (lr_inner)), BITS_PER_WORD,
5976 volatilep, &rnmode))
5977 return 0;
5979 rnbitsize = GET_MODE_BITSIZE (rnmode);
5980 rnbitpos = first_bit & ~ (rnbitsize - 1);
5981 rntype = lang_hooks.types.type_for_size (rnbitsize, 1);
5982 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
5984 if (lr_reversep ? !BYTES_BIG_ENDIAN : BYTES_BIG_ENDIAN)
5986 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
5987 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
5990 lr_mask = const_binop (LSHIFT_EXPR, fold_convert_loc (loc,
5991 rntype, lr_mask),
5992 size_int (xlr_bitpos));
5993 rr_mask = const_binop (LSHIFT_EXPR, fold_convert_loc (loc,
5994 rntype, rr_mask),
5995 size_int (xrr_bitpos));
5997 /* Make a mask that corresponds to both fields being compared.
5998 Do this for both items being compared. If the operands are the
5999 same size and the bits being compared are in the same position
6000 then we can do this by masking both and comparing the masked
6001 results. */
6002 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask);
6003 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask);
6004 if (lnbitsize == rnbitsize
6005 && xll_bitpos == xlr_bitpos
6006 && lnbitpos >= 0
6007 && rnbitpos >= 0)
6009 lhs = make_bit_field_ref (loc, ll_inner, ll_arg,
6010 lntype, lnbitsize, lnbitpos,
6011 ll_unsignedp || rl_unsignedp, ll_reversep);
6012 if (! all_ones_mask_p (ll_mask, lnbitsize))
6013 lhs = build2 (BIT_AND_EXPR, lntype, lhs, ll_mask);
6015 rhs = make_bit_field_ref (loc, lr_inner, lr_arg,
6016 rntype, rnbitsize, rnbitpos,
6017 lr_unsignedp || rr_unsignedp, lr_reversep);
6018 if (! all_ones_mask_p (lr_mask, rnbitsize))
6019 rhs = build2 (BIT_AND_EXPR, rntype, rhs, lr_mask);
6021 return build2_loc (loc, wanted_code, truth_type, lhs, rhs);
6024 /* There is still another way we can do something: If both pairs of
6025 fields being compared are adjacent, we may be able to make a wider
6026 field containing them both.
6028 Note that we still must mask the lhs/rhs expressions. Furthermore,
6029 the mask must be shifted to account for the shift done by
6030 make_bit_field_ref. */
6031 if (((ll_bitsize + ll_bitpos == rl_bitpos
6032 && lr_bitsize + lr_bitpos == rr_bitpos)
6033 || (ll_bitpos == rl_bitpos + rl_bitsize
6034 && lr_bitpos == rr_bitpos + rr_bitsize))
6035 && ll_bitpos >= 0
6036 && rl_bitpos >= 0
6037 && lr_bitpos >= 0
6038 && rr_bitpos >= 0)
6040 tree type;
6042 lhs = make_bit_field_ref (loc, ll_inner, ll_arg, lntype,
6043 ll_bitsize + rl_bitsize,
6044 MIN (ll_bitpos, rl_bitpos),
6045 ll_unsignedp, ll_reversep);
6046 rhs = make_bit_field_ref (loc, lr_inner, lr_arg, rntype,
6047 lr_bitsize + rr_bitsize,
6048 MIN (lr_bitpos, rr_bitpos),
6049 lr_unsignedp, lr_reversep);
6051 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
6052 size_int (MIN (xll_bitpos, xrl_bitpos)));
6053 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
6054 size_int (MIN (xlr_bitpos, xrr_bitpos)));
6056 /* Convert to the smaller type before masking out unwanted bits. */
6057 type = lntype;
6058 if (lntype != rntype)
6060 if (lnbitsize > rnbitsize)
6062 lhs = fold_convert_loc (loc, rntype, lhs);
6063 ll_mask = fold_convert_loc (loc, rntype, ll_mask);
6064 type = rntype;
6066 else if (lnbitsize < rnbitsize)
6068 rhs = fold_convert_loc (loc, lntype, rhs);
6069 lr_mask = fold_convert_loc (loc, lntype, lr_mask);
6070 type = lntype;
6074 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
6075 lhs = build2 (BIT_AND_EXPR, type, lhs, ll_mask);
6077 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
6078 rhs = build2 (BIT_AND_EXPR, type, rhs, lr_mask);
6080 return build2_loc (loc, wanted_code, truth_type, lhs, rhs);
6083 return 0;
6086 /* Handle the case of comparisons with constants. If there is something in
6087 common between the masks, those bits of the constants must be the same.
6088 If not, the condition is always false. Test for this to avoid generating
6089 incorrect code below. */
6090 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask);
6091 if (! integer_zerop (result)
6092 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const),
6093 const_binop (BIT_AND_EXPR, result, r_const)) != 1)
6095 if (wanted_code == NE_EXPR)
6097 warning (0, "%<or%> of unmatched not-equal tests is always 1");
6098 return constant_boolean_node (true, truth_type);
6100 else
6102 warning (0, "%<and%> of mutually exclusive equal-tests is always 0");
6103 return constant_boolean_node (false, truth_type);
6107 if (lnbitpos < 0)
6108 return 0;
6110 /* Construct the expression we will return. First get the component
6111 reference we will make. Unless the mask is all ones the width of
6112 that field, perform the mask operation. Then compare with the
6113 merged constant. */
6114 result = make_bit_field_ref (loc, ll_inner, ll_arg,
6115 lntype, lnbitsize, lnbitpos,
6116 ll_unsignedp || rl_unsignedp, ll_reversep);
6118 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask);
6119 if (! all_ones_mask_p (ll_mask, lnbitsize))
6120 result = build2_loc (loc, BIT_AND_EXPR, lntype, result, ll_mask);
6122 return build2_loc (loc, wanted_code, truth_type, result,
6123 const_binop (BIT_IOR_EXPR, l_const, r_const));
6126 /* T is an integer expression that is being multiplied, divided, or taken a
6127 modulus (CODE says which and what kind of divide or modulus) by a
6128 constant C. See if we can eliminate that operation by folding it with
6129 other operations already in T. WIDE_TYPE, if non-null, is a type that
6130 should be used for the computation if wider than our type.
6132 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
6133 (X * 2) + (Y * 4). We must, however, be assured that either the original
6134 expression would not overflow or that overflow is undefined for the type
6135 in the language in question.
6137 If we return a non-null expression, it is an equivalent form of the
6138 original computation, but need not be in the original type.
6140 We set *STRICT_OVERFLOW_P to true if the return values depends on
6141 signed overflow being undefined. Otherwise we do not change
6142 *STRICT_OVERFLOW_P. */
6144 static tree
6145 extract_muldiv (tree t, tree c, enum tree_code code, tree wide_type,
6146 bool *strict_overflow_p)
6148 /* To avoid exponential search depth, refuse to allow recursion past
6149 three levels. Beyond that (1) it's highly unlikely that we'll find
6150 something interesting and (2) we've probably processed it before
6151 when we built the inner expression. */
6153 static int depth;
6154 tree ret;
6156 if (depth > 3)
6157 return NULL;
6159 depth++;
6160 ret = extract_muldiv_1 (t, c, code, wide_type, strict_overflow_p);
6161 depth--;
6163 return ret;
6166 static tree
6167 extract_muldiv_1 (tree t, tree c, enum tree_code code, tree wide_type,
6168 bool *strict_overflow_p)
6170 tree type = TREE_TYPE (t);
6171 enum tree_code tcode = TREE_CODE (t);
6172 tree ctype = (wide_type != 0
6173 && (GET_MODE_SIZE (SCALAR_INT_TYPE_MODE (wide_type))
6174 > GET_MODE_SIZE (SCALAR_INT_TYPE_MODE (type)))
6175 ? wide_type : type);
6176 tree t1, t2;
6177 int same_p = tcode == code;
6178 tree op0 = NULL_TREE, op1 = NULL_TREE;
6179 bool sub_strict_overflow_p;
6181 /* Don't deal with constants of zero here; they confuse the code below. */
6182 if (integer_zerop (c))
6183 return NULL_TREE;
6185 if (TREE_CODE_CLASS (tcode) == tcc_unary)
6186 op0 = TREE_OPERAND (t, 0);
6188 if (TREE_CODE_CLASS (tcode) == tcc_binary)
6189 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
6191 /* Note that we need not handle conditional operations here since fold
6192 already handles those cases. So just do arithmetic here. */
6193 switch (tcode)
6195 case INTEGER_CST:
6196 /* For a constant, we can always simplify if we are a multiply
6197 or (for divide and modulus) if it is a multiple of our constant. */
6198 if (code == MULT_EXPR
6199 || wi::multiple_of_p (wi::to_wide (t), wi::to_wide (c),
6200 TYPE_SIGN (type)))
6202 tree tem = const_binop (code, fold_convert (ctype, t),
6203 fold_convert (ctype, c));
6204 /* If the multiplication overflowed, we lost information on it.
6205 See PR68142 and PR69845. */
6206 if (TREE_OVERFLOW (tem))
6207 return NULL_TREE;
6208 return tem;
6210 break;
6212 CASE_CONVERT: case NON_LVALUE_EXPR:
6213 /* If op0 is an expression ... */
6214 if ((COMPARISON_CLASS_P (op0)
6215 || UNARY_CLASS_P (op0)
6216 || BINARY_CLASS_P (op0)
6217 || VL_EXP_CLASS_P (op0)
6218 || EXPRESSION_CLASS_P (op0))
6219 /* ... and has wrapping overflow, and its type is smaller
6220 than ctype, then we cannot pass through as widening. */
6221 && (((ANY_INTEGRAL_TYPE_P (TREE_TYPE (op0))
6222 && TYPE_OVERFLOW_WRAPS (TREE_TYPE (op0)))
6223 && (TYPE_PRECISION (ctype)
6224 > TYPE_PRECISION (TREE_TYPE (op0))))
6225 /* ... or this is a truncation (t is narrower than op0),
6226 then we cannot pass through this narrowing. */
6227 || (TYPE_PRECISION (type)
6228 < TYPE_PRECISION (TREE_TYPE (op0)))
6229 /* ... or signedness changes for division or modulus,
6230 then we cannot pass through this conversion. */
6231 || (code != MULT_EXPR
6232 && (TYPE_UNSIGNED (ctype)
6233 != TYPE_UNSIGNED (TREE_TYPE (op0))))
6234 /* ... or has undefined overflow while the converted to
6235 type has not, we cannot do the operation in the inner type
6236 as that would introduce undefined overflow. */
6237 || ((ANY_INTEGRAL_TYPE_P (TREE_TYPE (op0))
6238 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (op0)))
6239 && !TYPE_OVERFLOW_UNDEFINED (type))))
6240 break;
6242 /* Pass the constant down and see if we can make a simplification. If
6243 we can, replace this expression with the inner simplification for
6244 possible later conversion to our or some other type. */
6245 if ((t2 = fold_convert (TREE_TYPE (op0), c)) != 0
6246 && TREE_CODE (t2) == INTEGER_CST
6247 && !TREE_OVERFLOW (t2)
6248 && (t1 = extract_muldiv (op0, t2, code,
6249 code == MULT_EXPR ? ctype : NULL_TREE,
6250 strict_overflow_p)) != 0)
6251 return t1;
6252 break;
6254 case ABS_EXPR:
6255 /* If widening the type changes it from signed to unsigned, then we
6256 must avoid building ABS_EXPR itself as unsigned. */
6257 if (TYPE_UNSIGNED (ctype) && !TYPE_UNSIGNED (type))
6259 tree cstype = (*signed_type_for) (ctype);
6260 if ((t1 = extract_muldiv (op0, c, code, cstype, strict_overflow_p))
6261 != 0)
6263 t1 = fold_build1 (tcode, cstype, fold_convert (cstype, t1));
6264 return fold_convert (ctype, t1);
6266 break;
6268 /* If the constant is negative, we cannot simplify this. */
6269 if (tree_int_cst_sgn (c) == -1)
6270 break;
6271 /* FALLTHROUGH */
6272 case NEGATE_EXPR:
6273 /* For division and modulus, type can't be unsigned, as e.g.
6274 (-(x / 2U)) / 2U isn't equal to -((x / 2U) / 2U) for x >= 2.
6275 For signed types, even with wrapping overflow, this is fine. */
6276 if (code != MULT_EXPR && TYPE_UNSIGNED (type))
6277 break;
6278 if ((t1 = extract_muldiv (op0, c, code, wide_type, strict_overflow_p))
6279 != 0)
6280 return fold_build1 (tcode, ctype, fold_convert (ctype, t1));
6281 break;
6283 case MIN_EXPR: case MAX_EXPR:
6284 /* If widening the type changes the signedness, then we can't perform
6285 this optimization as that changes the result. */
6286 if (TYPE_UNSIGNED (ctype) != TYPE_UNSIGNED (type))
6287 break;
6289 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
6290 sub_strict_overflow_p = false;
6291 if ((t1 = extract_muldiv (op0, c, code, wide_type,
6292 &sub_strict_overflow_p)) != 0
6293 && (t2 = extract_muldiv (op1, c, code, wide_type,
6294 &sub_strict_overflow_p)) != 0)
6296 if (tree_int_cst_sgn (c) < 0)
6297 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
6298 if (sub_strict_overflow_p)
6299 *strict_overflow_p = true;
6300 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
6301 fold_convert (ctype, t2));
6303 break;
6305 case LSHIFT_EXPR: case RSHIFT_EXPR:
6306 /* If the second operand is constant, this is a multiplication
6307 or floor division, by a power of two, so we can treat it that
6308 way unless the multiplier or divisor overflows. Signed
6309 left-shift overflow is implementation-defined rather than
6310 undefined in C90, so do not convert signed left shift into
6311 multiplication. */
6312 if (TREE_CODE (op1) == INTEGER_CST
6313 && (tcode == RSHIFT_EXPR || TYPE_UNSIGNED (TREE_TYPE (op0)))
6314 /* const_binop may not detect overflow correctly,
6315 so check for it explicitly here. */
6316 && wi::gtu_p (TYPE_PRECISION (TREE_TYPE (size_one_node)),
6317 wi::to_wide (op1))
6318 && (t1 = fold_convert (ctype,
6319 const_binop (LSHIFT_EXPR, size_one_node,
6320 op1))) != 0
6321 && !TREE_OVERFLOW (t1))
6322 return extract_muldiv (build2 (tcode == LSHIFT_EXPR
6323 ? MULT_EXPR : FLOOR_DIV_EXPR,
6324 ctype,
6325 fold_convert (ctype, op0),
6326 t1),
6327 c, code, wide_type, strict_overflow_p);
6328 break;
6330 case PLUS_EXPR: case MINUS_EXPR:
6331 /* See if we can eliminate the operation on both sides. If we can, we
6332 can return a new PLUS or MINUS. If we can't, the only remaining
6333 cases where we can do anything are if the second operand is a
6334 constant. */
6335 sub_strict_overflow_p = false;
6336 t1 = extract_muldiv (op0, c, code, wide_type, &sub_strict_overflow_p);
6337 t2 = extract_muldiv (op1, c, code, wide_type, &sub_strict_overflow_p);
6338 if (t1 != 0 && t2 != 0
6339 && TYPE_OVERFLOW_WRAPS (ctype)
6340 && (code == MULT_EXPR
6341 /* If not multiplication, we can only do this if both operands
6342 are divisible by c. */
6343 || (multiple_of_p (ctype, op0, c)
6344 && multiple_of_p (ctype, op1, c))))
6346 if (sub_strict_overflow_p)
6347 *strict_overflow_p = true;
6348 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
6349 fold_convert (ctype, t2));
6352 /* If this was a subtraction, negate OP1 and set it to be an addition.
6353 This simplifies the logic below. */
6354 if (tcode == MINUS_EXPR)
6356 tcode = PLUS_EXPR, op1 = negate_expr (op1);
6357 /* If OP1 was not easily negatable, the constant may be OP0. */
6358 if (TREE_CODE (op0) == INTEGER_CST)
6360 std::swap (op0, op1);
6361 std::swap (t1, t2);
6365 if (TREE_CODE (op1) != INTEGER_CST)
6366 break;
6368 /* If either OP1 or C are negative, this optimization is not safe for
6369 some of the division and remainder types while for others we need
6370 to change the code. */
6371 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
6373 if (code == CEIL_DIV_EXPR)
6374 code = FLOOR_DIV_EXPR;
6375 else if (code == FLOOR_DIV_EXPR)
6376 code = CEIL_DIV_EXPR;
6377 else if (code != MULT_EXPR
6378 && code != CEIL_MOD_EXPR && code != FLOOR_MOD_EXPR)
6379 break;
6382 /* If it's a multiply or a division/modulus operation of a multiple
6383 of our constant, do the operation and verify it doesn't overflow. */
6384 if (code == MULT_EXPR
6385 || wi::multiple_of_p (wi::to_wide (op1), wi::to_wide (c),
6386 TYPE_SIGN (type)))
6388 op1 = const_binop (code, fold_convert (ctype, op1),
6389 fold_convert (ctype, c));
6390 /* We allow the constant to overflow with wrapping semantics. */
6391 if (op1 == 0
6392 || (TREE_OVERFLOW (op1) && !TYPE_OVERFLOW_WRAPS (ctype)))
6393 break;
6395 else
6396 break;
6398 /* If we have an unsigned type, we cannot widen the operation since it
6399 will change the result if the original computation overflowed. */
6400 if (TYPE_UNSIGNED (ctype) && ctype != type)
6401 break;
6403 /* The last case is if we are a multiply. In that case, we can
6404 apply the distributive law to commute the multiply and addition
6405 if the multiplication of the constants doesn't overflow
6406 and overflow is defined. With undefined overflow
6407 op0 * c might overflow, while (op0 + orig_op1) * c doesn't. */
6408 if (code == MULT_EXPR && TYPE_OVERFLOW_WRAPS (ctype))
6409 return fold_build2 (tcode, ctype,
6410 fold_build2 (code, ctype,
6411 fold_convert (ctype, op0),
6412 fold_convert (ctype, c)),
6413 op1);
6415 break;
6417 case MULT_EXPR:
6418 /* We have a special case here if we are doing something like
6419 (C * 8) % 4 since we know that's zero. */
6420 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
6421 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
6422 /* If the multiplication can overflow we cannot optimize this. */
6423 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (t))
6424 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
6425 && wi::multiple_of_p (wi::to_wide (op1), wi::to_wide (c),
6426 TYPE_SIGN (type)))
6428 *strict_overflow_p = true;
6429 return omit_one_operand (type, integer_zero_node, op0);
6432 /* ... fall through ... */
6434 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
6435 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
6436 /* If we can extract our operation from the LHS, do so and return a
6437 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
6438 do something only if the second operand is a constant. */
6439 if (same_p
6440 && TYPE_OVERFLOW_WRAPS (ctype)
6441 && (t1 = extract_muldiv (op0, c, code, wide_type,
6442 strict_overflow_p)) != 0)
6443 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
6444 fold_convert (ctype, op1));
6445 else if (tcode == MULT_EXPR && code == MULT_EXPR
6446 && TYPE_OVERFLOW_WRAPS (ctype)
6447 && (t1 = extract_muldiv (op1, c, code, wide_type,
6448 strict_overflow_p)) != 0)
6449 return fold_build2 (tcode, ctype, fold_convert (ctype, op0),
6450 fold_convert (ctype, t1));
6451 else if (TREE_CODE (op1) != INTEGER_CST)
6452 return 0;
6454 /* If these are the same operation types, we can associate them
6455 assuming no overflow. */
6456 if (tcode == code)
6458 bool overflow_p = false;
6459 bool overflow_mul_p;
6460 signop sign = TYPE_SIGN (ctype);
6461 unsigned prec = TYPE_PRECISION (ctype);
6462 wide_int mul = wi::mul (wi::to_wide (op1, prec),
6463 wi::to_wide (c, prec),
6464 sign, &overflow_mul_p);
6465 overflow_p = TREE_OVERFLOW (c) | TREE_OVERFLOW (op1);
6466 if (overflow_mul_p
6467 && ((sign == UNSIGNED && tcode != MULT_EXPR) || sign == SIGNED))
6468 overflow_p = true;
6469 if (!overflow_p)
6470 return fold_build2 (tcode, ctype, fold_convert (ctype, op0),
6471 wide_int_to_tree (ctype, mul));
6474 /* If these operations "cancel" each other, we have the main
6475 optimizations of this pass, which occur when either constant is a
6476 multiple of the other, in which case we replace this with either an
6477 operation or CODE or TCODE.
6479 If we have an unsigned type, we cannot do this since it will change
6480 the result if the original computation overflowed. */
6481 if (TYPE_OVERFLOW_UNDEFINED (ctype)
6482 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
6483 || (tcode == MULT_EXPR
6484 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
6485 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR
6486 && code != MULT_EXPR)))
6488 if (wi::multiple_of_p (wi::to_wide (op1), wi::to_wide (c),
6489 TYPE_SIGN (type)))
6491 if (TYPE_OVERFLOW_UNDEFINED (ctype))
6492 *strict_overflow_p = true;
6493 return fold_build2 (tcode, ctype, fold_convert (ctype, op0),
6494 fold_convert (ctype,
6495 const_binop (TRUNC_DIV_EXPR,
6496 op1, c)));
6498 else if (wi::multiple_of_p (wi::to_wide (c), wi::to_wide (op1),
6499 TYPE_SIGN (type)))
6501 if (TYPE_OVERFLOW_UNDEFINED (ctype))
6502 *strict_overflow_p = true;
6503 return fold_build2 (code, ctype, fold_convert (ctype, op0),
6504 fold_convert (ctype,
6505 const_binop (TRUNC_DIV_EXPR,
6506 c, op1)));
6509 break;
6511 default:
6512 break;
6515 return 0;
6518 /* Return a node which has the indicated constant VALUE (either 0 or
6519 1 for scalars or {-1,-1,..} or {0,0,...} for vectors),
6520 and is of the indicated TYPE. */
6522 tree
6523 constant_boolean_node (bool value, tree type)
6525 if (type == integer_type_node)
6526 return value ? integer_one_node : integer_zero_node;
6527 else if (type == boolean_type_node)
6528 return value ? boolean_true_node : boolean_false_node;
6529 else if (TREE_CODE (type) == VECTOR_TYPE)
6530 return build_vector_from_val (type,
6531 build_int_cst (TREE_TYPE (type),
6532 value ? -1 : 0));
6533 else
6534 return fold_convert (type, value ? integer_one_node : integer_zero_node);
6538 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
6539 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
6540 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
6541 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
6542 COND is the first argument to CODE; otherwise (as in the example
6543 given here), it is the second argument. TYPE is the type of the
6544 original expression. Return NULL_TREE if no simplification is
6545 possible. */
6547 static tree
6548 fold_binary_op_with_conditional_arg (location_t loc,
6549 enum tree_code code,
6550 tree type, tree op0, tree op1,
6551 tree cond, tree arg, int cond_first_p)
6553 tree cond_type = cond_first_p ? TREE_TYPE (op0) : TREE_TYPE (op1);
6554 tree arg_type = cond_first_p ? TREE_TYPE (op1) : TREE_TYPE (op0);
6555 tree test, true_value, false_value;
6556 tree lhs = NULL_TREE;
6557 tree rhs = NULL_TREE;
6558 enum tree_code cond_code = COND_EXPR;
6560 if (TREE_CODE (cond) == COND_EXPR
6561 || TREE_CODE (cond) == VEC_COND_EXPR)
6563 test = TREE_OPERAND (cond, 0);
6564 true_value = TREE_OPERAND (cond, 1);
6565 false_value = TREE_OPERAND (cond, 2);
6566 /* If this operand throws an expression, then it does not make
6567 sense to try to perform a logical or arithmetic operation
6568 involving it. */
6569 if (VOID_TYPE_P (TREE_TYPE (true_value)))
6570 lhs = true_value;
6571 if (VOID_TYPE_P (TREE_TYPE (false_value)))
6572 rhs = false_value;
6574 else if (!(TREE_CODE (type) != VECTOR_TYPE
6575 && TREE_CODE (TREE_TYPE (cond)) == VECTOR_TYPE))
6577 tree testtype = TREE_TYPE (cond);
6578 test = cond;
6579 true_value = constant_boolean_node (true, testtype);
6580 false_value = constant_boolean_node (false, testtype);
6582 else
6583 /* Detect the case of mixing vector and scalar types - bail out. */
6584 return NULL_TREE;
6586 if (TREE_CODE (TREE_TYPE (test)) == VECTOR_TYPE)
6587 cond_code = VEC_COND_EXPR;
6589 /* This transformation is only worthwhile if we don't have to wrap ARG
6590 in a SAVE_EXPR and the operation can be simplified without recursing
6591 on at least one of the branches once its pushed inside the COND_EXPR. */
6592 if (!TREE_CONSTANT (arg)
6593 && (TREE_SIDE_EFFECTS (arg)
6594 || TREE_CODE (arg) == COND_EXPR || TREE_CODE (arg) == VEC_COND_EXPR
6595 || TREE_CONSTANT (true_value) || TREE_CONSTANT (false_value)))
6596 return NULL_TREE;
6598 arg = fold_convert_loc (loc, arg_type, arg);
6599 if (lhs == 0)
6601 true_value = fold_convert_loc (loc, cond_type, true_value);
6602 if (cond_first_p)
6603 lhs = fold_build2_loc (loc, code, type, true_value, arg);
6604 else
6605 lhs = fold_build2_loc (loc, code, type, arg, true_value);
6607 if (rhs == 0)
6609 false_value = fold_convert_loc (loc, cond_type, false_value);
6610 if (cond_first_p)
6611 rhs = fold_build2_loc (loc, code, type, false_value, arg);
6612 else
6613 rhs = fold_build2_loc (loc, code, type, arg, false_value);
6616 /* Check that we have simplified at least one of the branches. */
6617 if (!TREE_CONSTANT (arg) && !TREE_CONSTANT (lhs) && !TREE_CONSTANT (rhs))
6618 return NULL_TREE;
6620 return fold_build3_loc (loc, cond_code, type, test, lhs, rhs);
6624 /* Subroutine of fold() that checks for the addition of +/- 0.0.
6626 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
6627 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
6628 ADDEND is the same as X.
6630 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
6631 and finite. The problematic cases are when X is zero, and its mode
6632 has signed zeros. In the case of rounding towards -infinity,
6633 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
6634 modes, X + 0 is not the same as X because -0 + 0 is 0. */
6636 bool
6637 fold_real_zero_addition_p (const_tree type, const_tree addend, int negate)
6639 if (!real_zerop (addend))
6640 return false;
6642 /* Don't allow the fold with -fsignaling-nans. */
6643 if (HONOR_SNANS (element_mode (type)))
6644 return false;
6646 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
6647 if (!HONOR_SIGNED_ZEROS (element_mode (type)))
6648 return true;
6650 /* In a vector or complex, we would need to check the sign of all zeros. */
6651 if (TREE_CODE (addend) != REAL_CST)
6652 return false;
6654 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
6655 if (REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
6656 negate = !negate;
6658 /* The mode has signed zeros, and we have to honor their sign.
6659 In this situation, there is only one case we can return true for.
6660 X - 0 is the same as X unless rounding towards -infinity is
6661 supported. */
6662 return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (element_mode (type));
6665 /* Subroutine of match.pd that optimizes comparisons of a division by
6666 a nonzero integer constant against an integer constant, i.e.
6667 X/C1 op C2.
6669 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
6670 GE_EXPR or LE_EXPR. ARG01 and ARG1 must be a INTEGER_CST. */
6672 enum tree_code
6673 fold_div_compare (enum tree_code code, tree c1, tree c2, tree *lo,
6674 tree *hi, bool *neg_overflow)
6676 tree prod, tmp, type = TREE_TYPE (c1);
6677 signop sign = TYPE_SIGN (type);
6678 bool overflow;
6680 /* We have to do this the hard way to detect unsigned overflow.
6681 prod = int_const_binop (MULT_EXPR, c1, c2); */
6682 wide_int val = wi::mul (wi::to_wide (c1), wi::to_wide (c2), sign, &overflow);
6683 prod = force_fit_type (type, val, -1, overflow);
6684 *neg_overflow = false;
6686 if (sign == UNSIGNED)
6688 tmp = int_const_binop (MINUS_EXPR, c1, build_int_cst (type, 1));
6689 *lo = prod;
6691 /* Likewise *hi = int_const_binop (PLUS_EXPR, prod, tmp). */
6692 val = wi::add (wi::to_wide (prod), wi::to_wide (tmp), sign, &overflow);
6693 *hi = force_fit_type (type, val, -1, overflow | TREE_OVERFLOW (prod));
6695 else if (tree_int_cst_sgn (c1) >= 0)
6697 tmp = int_const_binop (MINUS_EXPR, c1, build_int_cst (type, 1));
6698 switch (tree_int_cst_sgn (c2))
6700 case -1:
6701 *neg_overflow = true;
6702 *lo = int_const_binop (MINUS_EXPR, prod, tmp);
6703 *hi = prod;
6704 break;
6706 case 0:
6707 *lo = fold_negate_const (tmp, type);
6708 *hi = tmp;
6709 break;
6711 case 1:
6712 *hi = int_const_binop (PLUS_EXPR, prod, tmp);
6713 *lo = prod;
6714 break;
6716 default:
6717 gcc_unreachable ();
6720 else
6722 /* A negative divisor reverses the relational operators. */
6723 code = swap_tree_comparison (code);
6725 tmp = int_const_binop (PLUS_EXPR, c1, build_int_cst (type, 1));
6726 switch (tree_int_cst_sgn (c2))
6728 case -1:
6729 *hi = int_const_binop (MINUS_EXPR, prod, tmp);
6730 *lo = prod;
6731 break;
6733 case 0:
6734 *hi = fold_negate_const (tmp, type);
6735 *lo = tmp;
6736 break;
6738 case 1:
6739 *neg_overflow = true;
6740 *lo = int_const_binop (PLUS_EXPR, prod, tmp);
6741 *hi = prod;
6742 break;
6744 default:
6745 gcc_unreachable ();
6749 if (code != EQ_EXPR && code != NE_EXPR)
6750 return code;
6752 if (TREE_OVERFLOW (*lo)
6753 || operand_equal_p (*lo, TYPE_MIN_VALUE (type), 0))
6754 *lo = NULL_TREE;
6755 if (TREE_OVERFLOW (*hi)
6756 || operand_equal_p (*hi, TYPE_MAX_VALUE (type), 0))
6757 *hi = NULL_TREE;
6759 return code;
6763 /* If CODE with arguments ARG0 and ARG1 represents a single bit
6764 equality/inequality test, then return a simplified form of the test
6765 using a sign testing. Otherwise return NULL. TYPE is the desired
6766 result type. */
6768 static tree
6769 fold_single_bit_test_into_sign_test (location_t loc,
6770 enum tree_code code, tree arg0, tree arg1,
6771 tree result_type)
6773 /* If this is testing a single bit, we can optimize the test. */
6774 if ((code == NE_EXPR || code == EQ_EXPR)
6775 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
6776 && integer_pow2p (TREE_OPERAND (arg0, 1)))
6778 /* If we have (A & C) != 0 where C is the sign bit of A, convert
6779 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
6780 tree arg00 = sign_bit_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
6782 if (arg00 != NULL_TREE
6783 /* This is only a win if casting to a signed type is cheap,
6784 i.e. when arg00's type is not a partial mode. */
6785 && type_has_mode_precision_p (TREE_TYPE (arg00)))
6787 tree stype = signed_type_for (TREE_TYPE (arg00));
6788 return fold_build2_loc (loc, code == EQ_EXPR ? GE_EXPR : LT_EXPR,
6789 result_type,
6790 fold_convert_loc (loc, stype, arg00),
6791 build_int_cst (stype, 0));
6795 return NULL_TREE;
6798 /* If CODE with arguments ARG0 and ARG1 represents a single bit
6799 equality/inequality test, then return a simplified form of
6800 the test using shifts and logical operations. Otherwise return
6801 NULL. TYPE is the desired result type. */
6803 tree
6804 fold_single_bit_test (location_t loc, enum tree_code code,
6805 tree arg0, tree arg1, tree result_type)
6807 /* If this is testing a single bit, we can optimize the test. */
6808 if ((code == NE_EXPR || code == EQ_EXPR)
6809 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
6810 && integer_pow2p (TREE_OPERAND (arg0, 1)))
6812 tree inner = TREE_OPERAND (arg0, 0);
6813 tree type = TREE_TYPE (arg0);
6814 int bitnum = tree_log2 (TREE_OPERAND (arg0, 1));
6815 scalar_int_mode operand_mode = SCALAR_INT_TYPE_MODE (type);
6816 int ops_unsigned;
6817 tree signed_type, unsigned_type, intermediate_type;
6818 tree tem, one;
6820 /* First, see if we can fold the single bit test into a sign-bit
6821 test. */
6822 tem = fold_single_bit_test_into_sign_test (loc, code, arg0, arg1,
6823 result_type);
6824 if (tem)
6825 return tem;
6827 /* Otherwise we have (A & C) != 0 where C is a single bit,
6828 convert that into ((A >> C2) & 1). Where C2 = log2(C).
6829 Similarly for (A & C) == 0. */
6831 /* If INNER is a right shift of a constant and it plus BITNUM does
6832 not overflow, adjust BITNUM and INNER. */
6833 if (TREE_CODE (inner) == RSHIFT_EXPR
6834 && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST
6835 && bitnum < TYPE_PRECISION (type)
6836 && wi::ltu_p (wi::to_wide (TREE_OPERAND (inner, 1)),
6837 TYPE_PRECISION (type) - bitnum))
6839 bitnum += tree_to_uhwi (TREE_OPERAND (inner, 1));
6840 inner = TREE_OPERAND (inner, 0);
6843 /* If we are going to be able to omit the AND below, we must do our
6844 operations as unsigned. If we must use the AND, we have a choice.
6845 Normally unsigned is faster, but for some machines signed is. */
6846 ops_unsigned = (load_extend_op (operand_mode) == SIGN_EXTEND
6847 && !flag_syntax_only) ? 0 : 1;
6849 signed_type = lang_hooks.types.type_for_mode (operand_mode, 0);
6850 unsigned_type = lang_hooks.types.type_for_mode (operand_mode, 1);
6851 intermediate_type = ops_unsigned ? unsigned_type : signed_type;
6852 inner = fold_convert_loc (loc, intermediate_type, inner);
6854 if (bitnum != 0)
6855 inner = build2 (RSHIFT_EXPR, intermediate_type,
6856 inner, size_int (bitnum));
6858 one = build_int_cst (intermediate_type, 1);
6860 if (code == EQ_EXPR)
6861 inner = fold_build2_loc (loc, BIT_XOR_EXPR, intermediate_type, inner, one);
6863 /* Put the AND last so it can combine with more things. */
6864 inner = build2 (BIT_AND_EXPR, intermediate_type, inner, one);
6866 /* Make sure to return the proper type. */
6867 inner = fold_convert_loc (loc, result_type, inner);
6869 return inner;
6871 return NULL_TREE;
6874 /* Test whether it is preferable two swap two operands, ARG0 and
6875 ARG1, for example because ARG0 is an integer constant and ARG1
6876 isn't. */
6878 bool
6879 tree_swap_operands_p (const_tree arg0, const_tree arg1)
6881 if (CONSTANT_CLASS_P (arg1))
6882 return 0;
6883 if (CONSTANT_CLASS_P (arg0))
6884 return 1;
6886 STRIP_NOPS (arg0);
6887 STRIP_NOPS (arg1);
6889 if (TREE_CONSTANT (arg1))
6890 return 0;
6891 if (TREE_CONSTANT (arg0))
6892 return 1;
6894 /* It is preferable to swap two SSA_NAME to ensure a canonical form
6895 for commutative and comparison operators. Ensuring a canonical
6896 form allows the optimizers to find additional redundancies without
6897 having to explicitly check for both orderings. */
6898 if (TREE_CODE (arg0) == SSA_NAME
6899 && TREE_CODE (arg1) == SSA_NAME
6900 && SSA_NAME_VERSION (arg0) > SSA_NAME_VERSION (arg1))
6901 return 1;
6903 /* Put SSA_NAMEs last. */
6904 if (TREE_CODE (arg1) == SSA_NAME)
6905 return 0;
6906 if (TREE_CODE (arg0) == SSA_NAME)
6907 return 1;
6909 /* Put variables last. */
6910 if (DECL_P (arg1))
6911 return 0;
6912 if (DECL_P (arg0))
6913 return 1;
6915 return 0;
6919 /* Fold A < X && A + 1 > Y to A < X && A >= Y. Normally A + 1 > Y
6920 means A >= Y && A != MAX, but in this case we know that
6921 A < X <= MAX. INEQ is A + 1 > Y, BOUND is A < X. */
6923 static tree
6924 fold_to_nonsharp_ineq_using_bound (location_t loc, tree ineq, tree bound)
6926 tree a, typea, type = TREE_TYPE (ineq), a1, diff, y;
6928 if (TREE_CODE (bound) == LT_EXPR)
6929 a = TREE_OPERAND (bound, 0);
6930 else if (TREE_CODE (bound) == GT_EXPR)
6931 a = TREE_OPERAND (bound, 1);
6932 else
6933 return NULL_TREE;
6935 typea = TREE_TYPE (a);
6936 if (!INTEGRAL_TYPE_P (typea)
6937 && !POINTER_TYPE_P (typea))
6938 return NULL_TREE;
6940 if (TREE_CODE (ineq) == LT_EXPR)
6942 a1 = TREE_OPERAND (ineq, 1);
6943 y = TREE_OPERAND (ineq, 0);
6945 else if (TREE_CODE (ineq) == GT_EXPR)
6947 a1 = TREE_OPERAND (ineq, 0);
6948 y = TREE_OPERAND (ineq, 1);
6950 else
6951 return NULL_TREE;
6953 if (TREE_TYPE (a1) != typea)
6954 return NULL_TREE;
6956 if (POINTER_TYPE_P (typea))
6958 /* Convert the pointer types into integer before taking the difference. */
6959 tree ta = fold_convert_loc (loc, ssizetype, a);
6960 tree ta1 = fold_convert_loc (loc, ssizetype, a1);
6961 diff = fold_binary_loc (loc, MINUS_EXPR, ssizetype, ta1, ta);
6963 else
6964 diff = fold_binary_loc (loc, MINUS_EXPR, typea, a1, a);
6966 if (!diff || !integer_onep (diff))
6967 return NULL_TREE;
6969 return fold_build2_loc (loc, GE_EXPR, type, a, y);
6972 /* Fold a sum or difference of at least one multiplication.
6973 Returns the folded tree or NULL if no simplification could be made. */
6975 static tree
6976 fold_plusminus_mult_expr (location_t loc, enum tree_code code, tree type,
6977 tree arg0, tree arg1)
6979 tree arg00, arg01, arg10, arg11;
6980 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
6982 /* (A * C) +- (B * C) -> (A+-B) * C.
6983 (A * C) +- A -> A * (C+-1).
6984 We are most concerned about the case where C is a constant,
6985 but other combinations show up during loop reduction. Since
6986 it is not difficult, try all four possibilities. */
6988 if (TREE_CODE (arg0) == MULT_EXPR)
6990 arg00 = TREE_OPERAND (arg0, 0);
6991 arg01 = TREE_OPERAND (arg0, 1);
6993 else if (TREE_CODE (arg0) == INTEGER_CST)
6995 arg00 = build_one_cst (type);
6996 arg01 = arg0;
6998 else
7000 /* We cannot generate constant 1 for fract. */
7001 if (ALL_FRACT_MODE_P (TYPE_MODE (type)))
7002 return NULL_TREE;
7003 arg00 = arg0;
7004 arg01 = build_one_cst (type);
7006 if (TREE_CODE (arg1) == MULT_EXPR)
7008 arg10 = TREE_OPERAND (arg1, 0);
7009 arg11 = TREE_OPERAND (arg1, 1);
7011 else if (TREE_CODE (arg1) == INTEGER_CST)
7013 arg10 = build_one_cst (type);
7014 /* As we canonicalize A - 2 to A + -2 get rid of that sign for
7015 the purpose of this canonicalization. */
7016 if (wi::neg_p (wi::to_wide (arg1), TYPE_SIGN (TREE_TYPE (arg1)))
7017 && negate_expr_p (arg1)
7018 && code == PLUS_EXPR)
7020 arg11 = negate_expr (arg1);
7021 code = MINUS_EXPR;
7023 else
7024 arg11 = arg1;
7026 else
7028 /* We cannot generate constant 1 for fract. */
7029 if (ALL_FRACT_MODE_P (TYPE_MODE (type)))
7030 return NULL_TREE;
7031 arg10 = arg1;
7032 arg11 = build_one_cst (type);
7034 same = NULL_TREE;
7036 /* Prefer factoring a common non-constant. */
7037 if (operand_equal_p (arg00, arg10, 0))
7038 same = arg00, alt0 = arg01, alt1 = arg11;
7039 else if (operand_equal_p (arg01, arg11, 0))
7040 same = arg01, alt0 = arg00, alt1 = arg10;
7041 else if (operand_equal_p (arg00, arg11, 0))
7042 same = arg00, alt0 = arg01, alt1 = arg10;
7043 else if (operand_equal_p (arg01, arg10, 0))
7044 same = arg01, alt0 = arg00, alt1 = arg11;
7046 /* No identical multiplicands; see if we can find a common
7047 power-of-two factor in non-power-of-two multiplies. This
7048 can help in multi-dimensional array access. */
7049 else if (tree_fits_shwi_p (arg01)
7050 && tree_fits_shwi_p (arg11))
7052 HOST_WIDE_INT int01, int11, tmp;
7053 bool swap = false;
7054 tree maybe_same;
7055 int01 = tree_to_shwi (arg01);
7056 int11 = tree_to_shwi (arg11);
7058 /* Move min of absolute values to int11. */
7059 if (absu_hwi (int01) < absu_hwi (int11))
7061 tmp = int01, int01 = int11, int11 = tmp;
7062 alt0 = arg00, arg00 = arg10, arg10 = alt0;
7063 maybe_same = arg01;
7064 swap = true;
7066 else
7067 maybe_same = arg11;
7069 if (exact_log2 (absu_hwi (int11)) > 0 && int01 % int11 == 0
7070 /* The remainder should not be a constant, otherwise we
7071 end up folding i * 4 + 2 to (i * 2 + 1) * 2 which has
7072 increased the number of multiplications necessary. */
7073 && TREE_CODE (arg10) != INTEGER_CST)
7075 alt0 = fold_build2_loc (loc, MULT_EXPR, TREE_TYPE (arg00), arg00,
7076 build_int_cst (TREE_TYPE (arg00),
7077 int01 / int11));
7078 alt1 = arg10;
7079 same = maybe_same;
7080 if (swap)
7081 maybe_same = alt0, alt0 = alt1, alt1 = maybe_same;
7085 if (!same)
7086 return NULL_TREE;
7088 if (! INTEGRAL_TYPE_P (type)
7089 || TYPE_OVERFLOW_WRAPS (type)
7090 /* We are neither factoring zero nor minus one. */
7091 || TREE_CODE (same) == INTEGER_CST)
7092 return fold_build2_loc (loc, MULT_EXPR, type,
7093 fold_build2_loc (loc, code, type,
7094 fold_convert_loc (loc, type, alt0),
7095 fold_convert_loc (loc, type, alt1)),
7096 fold_convert_loc (loc, type, same));
7098 /* Same may be zero and thus the operation 'code' may overflow. Likewise
7099 same may be minus one and thus the multiplication may overflow. Perform
7100 the sum operation in an unsigned type. */
7101 tree utype = unsigned_type_for (type);
7102 tree tem = fold_build2_loc (loc, code, utype,
7103 fold_convert_loc (loc, utype, alt0),
7104 fold_convert_loc (loc, utype, alt1));
7105 /* If the sum evaluated to a constant that is not -INF the multiplication
7106 cannot overflow. */
7107 if (TREE_CODE (tem) == INTEGER_CST
7108 && (wi::to_wide (tem)
7109 != wi::min_value (TYPE_PRECISION (utype), SIGNED)))
7110 return fold_build2_loc (loc, MULT_EXPR, type,
7111 fold_convert (type, tem), same);
7113 /* Do not resort to unsigned multiplication because
7114 we lose the no-overflow property of the expression. */
7115 return NULL_TREE;
7118 /* Subroutine of native_encode_expr. Encode the INTEGER_CST
7119 specified by EXPR into the buffer PTR of length LEN bytes.
7120 Return the number of bytes placed in the buffer, or zero
7121 upon failure. */
7123 static int
7124 native_encode_int (const_tree expr, unsigned char *ptr, int len, int off)
7126 tree type = TREE_TYPE (expr);
7127 int total_bytes = GET_MODE_SIZE (SCALAR_INT_TYPE_MODE (type));
7128 int byte, offset, word, words;
7129 unsigned char value;
7131 if ((off == -1 && total_bytes > len) || off >= total_bytes)
7132 return 0;
7133 if (off == -1)
7134 off = 0;
7136 if (ptr == NULL)
7137 /* Dry run. */
7138 return MIN (len, total_bytes - off);
7140 words = total_bytes / UNITS_PER_WORD;
7142 for (byte = 0; byte < total_bytes; byte++)
7144 int bitpos = byte * BITS_PER_UNIT;
7145 /* Extend EXPR according to TYPE_SIGN if the precision isn't a whole
7146 number of bytes. */
7147 value = wi::extract_uhwi (wi::to_widest (expr), bitpos, BITS_PER_UNIT);
7149 if (total_bytes > UNITS_PER_WORD)
7151 word = byte / UNITS_PER_WORD;
7152 if (WORDS_BIG_ENDIAN)
7153 word = (words - 1) - word;
7154 offset = word * UNITS_PER_WORD;
7155 if (BYTES_BIG_ENDIAN)
7156 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7157 else
7158 offset += byte % UNITS_PER_WORD;
7160 else
7161 offset = BYTES_BIG_ENDIAN ? (total_bytes - 1) - byte : byte;
7162 if (offset >= off && offset - off < len)
7163 ptr[offset - off] = value;
7165 return MIN (len, total_bytes - off);
7169 /* Subroutine of native_encode_expr. Encode the FIXED_CST
7170 specified by EXPR into the buffer PTR of length LEN bytes.
7171 Return the number of bytes placed in the buffer, or zero
7172 upon failure. */
7174 static int
7175 native_encode_fixed (const_tree expr, unsigned char *ptr, int len, int off)
7177 tree type = TREE_TYPE (expr);
7178 scalar_mode mode = SCALAR_TYPE_MODE (type);
7179 int total_bytes = GET_MODE_SIZE (mode);
7180 FIXED_VALUE_TYPE value;
7181 tree i_value, i_type;
7183 if (total_bytes * BITS_PER_UNIT > HOST_BITS_PER_DOUBLE_INT)
7184 return 0;
7186 i_type = lang_hooks.types.type_for_size (GET_MODE_BITSIZE (mode), 1);
7188 if (NULL_TREE == i_type || TYPE_PRECISION (i_type) != total_bytes)
7189 return 0;
7191 value = TREE_FIXED_CST (expr);
7192 i_value = double_int_to_tree (i_type, value.data);
7194 return native_encode_int (i_value, ptr, len, off);
7198 /* Subroutine of native_encode_expr. Encode the REAL_CST
7199 specified by EXPR into the buffer PTR of length LEN bytes.
7200 Return the number of bytes placed in the buffer, or zero
7201 upon failure. */
7203 static int
7204 native_encode_real (const_tree expr, unsigned char *ptr, int len, int off)
7206 tree type = TREE_TYPE (expr);
7207 int total_bytes = GET_MODE_SIZE (SCALAR_FLOAT_TYPE_MODE (type));
7208 int byte, offset, word, words, bitpos;
7209 unsigned char value;
7211 /* There are always 32 bits in each long, no matter the size of
7212 the hosts long. We handle floating point representations with
7213 up to 192 bits. */
7214 long tmp[6];
7216 if ((off == -1 && total_bytes > len) || off >= total_bytes)
7217 return 0;
7218 if (off == -1)
7219 off = 0;
7221 if (ptr == NULL)
7222 /* Dry run. */
7223 return MIN (len, total_bytes - off);
7225 words = (32 / BITS_PER_UNIT) / UNITS_PER_WORD;
7227 real_to_target (tmp, TREE_REAL_CST_PTR (expr), TYPE_MODE (type));
7229 for (bitpos = 0; bitpos < total_bytes * BITS_PER_UNIT;
7230 bitpos += BITS_PER_UNIT)
7232 byte = (bitpos / BITS_PER_UNIT) & 3;
7233 value = (unsigned char) (tmp[bitpos / 32] >> (bitpos & 31));
7235 if (UNITS_PER_WORD < 4)
7237 word = byte / UNITS_PER_WORD;
7238 if (WORDS_BIG_ENDIAN)
7239 word = (words - 1) - word;
7240 offset = word * UNITS_PER_WORD;
7241 if (BYTES_BIG_ENDIAN)
7242 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7243 else
7244 offset += byte % UNITS_PER_WORD;
7246 else
7248 offset = byte;
7249 if (BYTES_BIG_ENDIAN)
7251 /* Reverse bytes within each long, or within the entire float
7252 if it's smaller than a long (for HFmode). */
7253 offset = MIN (3, total_bytes - 1) - offset;
7254 gcc_assert (offset >= 0);
7257 offset = offset + ((bitpos / BITS_PER_UNIT) & ~3);
7258 if (offset >= off
7259 && offset - off < len)
7260 ptr[offset - off] = value;
7262 return MIN (len, total_bytes - off);
7265 /* Subroutine of native_encode_expr. Encode the COMPLEX_CST
7266 specified by EXPR into the buffer PTR of length LEN bytes.
7267 Return the number of bytes placed in the buffer, or zero
7268 upon failure. */
7270 static int
7271 native_encode_complex (const_tree expr, unsigned char *ptr, int len, int off)
7273 int rsize, isize;
7274 tree part;
7276 part = TREE_REALPART (expr);
7277 rsize = native_encode_expr (part, ptr, len, off);
7278 if (off == -1 && rsize == 0)
7279 return 0;
7280 part = TREE_IMAGPART (expr);
7281 if (off != -1)
7282 off = MAX (0, off - GET_MODE_SIZE (SCALAR_TYPE_MODE (TREE_TYPE (part))));
7283 isize = native_encode_expr (part, ptr ? ptr + rsize : NULL,
7284 len - rsize, off);
7285 if (off == -1 && isize != rsize)
7286 return 0;
7287 return rsize + isize;
7291 /* Subroutine of native_encode_expr. Encode the VECTOR_CST
7292 specified by EXPR into the buffer PTR of length LEN bytes.
7293 Return the number of bytes placed in the buffer, or zero
7294 upon failure. */
7296 static int
7297 native_encode_vector (const_tree expr, unsigned char *ptr, int len, int off)
7299 unsigned HOST_WIDE_INT i, count;
7300 int size, offset;
7301 tree itype, elem;
7303 offset = 0;
7304 if (!VECTOR_CST_NELTS (expr).is_constant (&count))
7305 return 0;
7306 itype = TREE_TYPE (TREE_TYPE (expr));
7307 size = GET_MODE_SIZE (SCALAR_TYPE_MODE (itype));
7308 for (i = 0; i < count; i++)
7310 if (off >= size)
7312 off -= size;
7313 continue;
7315 elem = VECTOR_CST_ELT (expr, i);
7316 int res = native_encode_expr (elem, ptr ? ptr + offset : NULL,
7317 len - offset, off);
7318 if ((off == -1 && res != size) || res == 0)
7319 return 0;
7320 offset += res;
7321 if (offset >= len)
7322 return offset;
7323 if (off != -1)
7324 off = 0;
7326 return offset;
7330 /* Subroutine of native_encode_expr. Encode the STRING_CST
7331 specified by EXPR into the buffer PTR of length LEN bytes.
7332 Return the number of bytes placed in the buffer, or zero
7333 upon failure. */
7335 static int
7336 native_encode_string (const_tree expr, unsigned char *ptr, int len, int off)
7338 tree type = TREE_TYPE (expr);
7340 /* Wide-char strings are encoded in target byte-order so native
7341 encoding them is trivial. */
7342 if (BITS_PER_UNIT != CHAR_BIT
7343 || TREE_CODE (type) != ARRAY_TYPE
7344 || TREE_CODE (TREE_TYPE (type)) != INTEGER_TYPE
7345 || !tree_fits_shwi_p (TYPE_SIZE_UNIT (type)))
7346 return 0;
7348 HOST_WIDE_INT total_bytes = tree_to_shwi (TYPE_SIZE_UNIT (TREE_TYPE (expr)));
7349 if ((off == -1 && total_bytes > len) || off >= total_bytes)
7350 return 0;
7351 if (off == -1)
7352 off = 0;
7353 if (ptr == NULL)
7354 /* Dry run. */;
7355 else if (TREE_STRING_LENGTH (expr) - off < MIN (total_bytes, len))
7357 int written = 0;
7358 if (off < TREE_STRING_LENGTH (expr))
7360 written = MIN (len, TREE_STRING_LENGTH (expr) - off);
7361 memcpy (ptr, TREE_STRING_POINTER (expr) + off, written);
7363 memset (ptr + written, 0,
7364 MIN (total_bytes - written, len - written));
7366 else
7367 memcpy (ptr, TREE_STRING_POINTER (expr) + off, MIN (total_bytes, len));
7368 return MIN (total_bytes - off, len);
7372 /* Subroutine of fold_view_convert_expr. Encode the INTEGER_CST,
7373 REAL_CST, COMPLEX_CST or VECTOR_CST specified by EXPR into the
7374 buffer PTR of length LEN bytes. If PTR is NULL, don't actually store
7375 anything, just do a dry run. If OFF is not -1 then start
7376 the encoding at byte offset OFF and encode at most LEN bytes.
7377 Return the number of bytes placed in the buffer, or zero upon failure. */
7380 native_encode_expr (const_tree expr, unsigned char *ptr, int len, int off)
7382 /* We don't support starting at negative offset and -1 is special. */
7383 if (off < -1)
7384 return 0;
7386 switch (TREE_CODE (expr))
7388 case INTEGER_CST:
7389 return native_encode_int (expr, ptr, len, off);
7391 case REAL_CST:
7392 return native_encode_real (expr, ptr, len, off);
7394 case FIXED_CST:
7395 return native_encode_fixed (expr, ptr, len, off);
7397 case COMPLEX_CST:
7398 return native_encode_complex (expr, ptr, len, off);
7400 case VECTOR_CST:
7401 return native_encode_vector (expr, ptr, len, off);
7403 case STRING_CST:
7404 return native_encode_string (expr, ptr, len, off);
7406 default:
7407 return 0;
7412 /* Subroutine of native_interpret_expr. Interpret the contents of
7413 the buffer PTR of length LEN as an INTEGER_CST of type TYPE.
7414 If the buffer cannot be interpreted, return NULL_TREE. */
7416 static tree
7417 native_interpret_int (tree type, const unsigned char *ptr, int len)
7419 int total_bytes = GET_MODE_SIZE (SCALAR_INT_TYPE_MODE (type));
7421 if (total_bytes > len
7422 || total_bytes * BITS_PER_UNIT > HOST_BITS_PER_DOUBLE_INT)
7423 return NULL_TREE;
7425 wide_int result = wi::from_buffer (ptr, total_bytes);
7427 return wide_int_to_tree (type, result);
7431 /* Subroutine of native_interpret_expr. Interpret the contents of
7432 the buffer PTR of length LEN as a FIXED_CST of type TYPE.
7433 If the buffer cannot be interpreted, return NULL_TREE. */
7435 static tree
7436 native_interpret_fixed (tree type, const unsigned char *ptr, int len)
7438 scalar_mode mode = SCALAR_TYPE_MODE (type);
7439 int total_bytes = GET_MODE_SIZE (mode);
7440 double_int result;
7441 FIXED_VALUE_TYPE fixed_value;
7443 if (total_bytes > len
7444 || total_bytes * BITS_PER_UNIT > HOST_BITS_PER_DOUBLE_INT)
7445 return NULL_TREE;
7447 result = double_int::from_buffer (ptr, total_bytes);
7448 fixed_value = fixed_from_double_int (result, mode);
7450 return build_fixed (type, fixed_value);
7454 /* Subroutine of native_interpret_expr. Interpret the contents of
7455 the buffer PTR of length LEN as a REAL_CST of type TYPE.
7456 If the buffer cannot be interpreted, return NULL_TREE. */
7458 static tree
7459 native_interpret_real (tree type, const unsigned char *ptr, int len)
7461 scalar_float_mode mode = SCALAR_FLOAT_TYPE_MODE (type);
7462 int total_bytes = GET_MODE_SIZE (mode);
7463 unsigned char value;
7464 /* There are always 32 bits in each long, no matter the size of
7465 the hosts long. We handle floating point representations with
7466 up to 192 bits. */
7467 REAL_VALUE_TYPE r;
7468 long tmp[6];
7470 if (total_bytes > len || total_bytes > 24)
7471 return NULL_TREE;
7472 int words = (32 / BITS_PER_UNIT) / UNITS_PER_WORD;
7474 memset (tmp, 0, sizeof (tmp));
7475 for (int bitpos = 0; bitpos < total_bytes * BITS_PER_UNIT;
7476 bitpos += BITS_PER_UNIT)
7478 /* Both OFFSET and BYTE index within a long;
7479 bitpos indexes the whole float. */
7480 int offset, byte = (bitpos / BITS_PER_UNIT) & 3;
7481 if (UNITS_PER_WORD < 4)
7483 int word = byte / UNITS_PER_WORD;
7484 if (WORDS_BIG_ENDIAN)
7485 word = (words - 1) - word;
7486 offset = word * UNITS_PER_WORD;
7487 if (BYTES_BIG_ENDIAN)
7488 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7489 else
7490 offset += byte % UNITS_PER_WORD;
7492 else
7494 offset = byte;
7495 if (BYTES_BIG_ENDIAN)
7497 /* Reverse bytes within each long, or within the entire float
7498 if it's smaller than a long (for HFmode). */
7499 offset = MIN (3, total_bytes - 1) - offset;
7500 gcc_assert (offset >= 0);
7503 value = ptr[offset + ((bitpos / BITS_PER_UNIT) & ~3)];
7505 tmp[bitpos / 32] |= (unsigned long)value << (bitpos & 31);
7508 real_from_target (&r, tmp, mode);
7509 return build_real (type, r);
7513 /* Subroutine of native_interpret_expr. Interpret the contents of
7514 the buffer PTR of length LEN as a COMPLEX_CST of type TYPE.
7515 If the buffer cannot be interpreted, return NULL_TREE. */
7517 static tree
7518 native_interpret_complex (tree type, const unsigned char *ptr, int len)
7520 tree etype, rpart, ipart;
7521 int size;
7523 etype = TREE_TYPE (type);
7524 size = GET_MODE_SIZE (SCALAR_TYPE_MODE (etype));
7525 if (size * 2 > len)
7526 return NULL_TREE;
7527 rpart = native_interpret_expr (etype, ptr, size);
7528 if (!rpart)
7529 return NULL_TREE;
7530 ipart = native_interpret_expr (etype, ptr+size, size);
7531 if (!ipart)
7532 return NULL_TREE;
7533 return build_complex (type, rpart, ipart);
7537 /* Subroutine of native_interpret_expr. Interpret the contents of
7538 the buffer PTR of length LEN as a VECTOR_CST of type TYPE.
7539 If the buffer cannot be interpreted, return NULL_TREE. */
7541 static tree
7542 native_interpret_vector (tree type, const unsigned char *ptr, unsigned int len)
7544 tree etype, elem;
7545 unsigned int i, size;
7546 unsigned HOST_WIDE_INT count;
7548 etype = TREE_TYPE (type);
7549 size = GET_MODE_SIZE (SCALAR_TYPE_MODE (etype));
7550 if (!TYPE_VECTOR_SUBPARTS (type).is_constant (&count)
7551 || size * count > len)
7552 return NULL_TREE;
7554 tree_vector_builder elements (type, count, 1);
7555 for (i = 0; i < count; ++i)
7557 elem = native_interpret_expr (etype, ptr+(i*size), size);
7558 if (!elem)
7559 return NULL_TREE;
7560 elements.quick_push (elem);
7562 return elements.build ();
7566 /* Subroutine of fold_view_convert_expr. Interpret the contents of
7567 the buffer PTR of length LEN as a constant of type TYPE. For
7568 INTEGRAL_TYPE_P we return an INTEGER_CST, for SCALAR_FLOAT_TYPE_P
7569 we return a REAL_CST, etc... If the buffer cannot be interpreted,
7570 return NULL_TREE. */
7572 tree
7573 native_interpret_expr (tree type, const unsigned char *ptr, int len)
7575 switch (TREE_CODE (type))
7577 case INTEGER_TYPE:
7578 case ENUMERAL_TYPE:
7579 case BOOLEAN_TYPE:
7580 case POINTER_TYPE:
7581 case REFERENCE_TYPE:
7582 return native_interpret_int (type, ptr, len);
7584 case REAL_TYPE:
7585 return native_interpret_real (type, ptr, len);
7587 case FIXED_POINT_TYPE:
7588 return native_interpret_fixed (type, ptr, len);
7590 case COMPLEX_TYPE:
7591 return native_interpret_complex (type, ptr, len);
7593 case VECTOR_TYPE:
7594 return native_interpret_vector (type, ptr, len);
7596 default:
7597 return NULL_TREE;
7601 /* Returns true if we can interpret the contents of a native encoding
7602 as TYPE. */
7604 static bool
7605 can_native_interpret_type_p (tree type)
7607 switch (TREE_CODE (type))
7609 case INTEGER_TYPE:
7610 case ENUMERAL_TYPE:
7611 case BOOLEAN_TYPE:
7612 case POINTER_TYPE:
7613 case REFERENCE_TYPE:
7614 case FIXED_POINT_TYPE:
7615 case REAL_TYPE:
7616 case COMPLEX_TYPE:
7617 case VECTOR_TYPE:
7618 return true;
7619 default:
7620 return false;
7625 /* Fold a VIEW_CONVERT_EXPR of a constant expression EXPR to type
7626 TYPE at compile-time. If we're unable to perform the conversion
7627 return NULL_TREE. */
7629 static tree
7630 fold_view_convert_expr (tree type, tree expr)
7632 /* We support up to 512-bit values (for V8DFmode). */
7633 unsigned char buffer[64];
7634 int len;
7636 /* Check that the host and target are sane. */
7637 if (CHAR_BIT != 8 || BITS_PER_UNIT != 8)
7638 return NULL_TREE;
7640 len = native_encode_expr (expr, buffer, sizeof (buffer));
7641 if (len == 0)
7642 return NULL_TREE;
7644 return native_interpret_expr (type, buffer, len);
7647 /* Build an expression for the address of T. Folds away INDIRECT_REF
7648 to avoid confusing the gimplify process. */
7650 tree
7651 build_fold_addr_expr_with_type_loc (location_t loc, tree t, tree ptrtype)
7653 /* The size of the object is not relevant when talking about its address. */
7654 if (TREE_CODE (t) == WITH_SIZE_EXPR)
7655 t = TREE_OPERAND (t, 0);
7657 if (TREE_CODE (t) == INDIRECT_REF)
7659 t = TREE_OPERAND (t, 0);
7661 if (TREE_TYPE (t) != ptrtype)
7662 t = build1_loc (loc, NOP_EXPR, ptrtype, t);
7664 else if (TREE_CODE (t) == MEM_REF
7665 && integer_zerop (TREE_OPERAND (t, 1)))
7666 return TREE_OPERAND (t, 0);
7667 else if (TREE_CODE (t) == MEM_REF
7668 && TREE_CODE (TREE_OPERAND (t, 0)) == INTEGER_CST)
7669 return fold_binary (POINTER_PLUS_EXPR, ptrtype,
7670 TREE_OPERAND (t, 0),
7671 convert_to_ptrofftype (TREE_OPERAND (t, 1)));
7672 else if (TREE_CODE (t) == VIEW_CONVERT_EXPR)
7674 t = build_fold_addr_expr_loc (loc, TREE_OPERAND (t, 0));
7676 if (TREE_TYPE (t) != ptrtype)
7677 t = fold_convert_loc (loc, ptrtype, t);
7679 else
7680 t = build1_loc (loc, ADDR_EXPR, ptrtype, t);
7682 return t;
7685 /* Build an expression for the address of T. */
7687 tree
7688 build_fold_addr_expr_loc (location_t loc, tree t)
7690 tree ptrtype = build_pointer_type (TREE_TYPE (t));
7692 return build_fold_addr_expr_with_type_loc (loc, t, ptrtype);
7695 /* Fold a unary expression of code CODE and type TYPE with operand
7696 OP0. Return the folded expression if folding is successful.
7697 Otherwise, return NULL_TREE. */
7699 tree
7700 fold_unary_loc (location_t loc, enum tree_code code, tree type, tree op0)
7702 tree tem;
7703 tree arg0;
7704 enum tree_code_class kind = TREE_CODE_CLASS (code);
7706 gcc_assert (IS_EXPR_CODE_CLASS (kind)
7707 && TREE_CODE_LENGTH (code) == 1);
7709 arg0 = op0;
7710 if (arg0)
7712 if (CONVERT_EXPR_CODE_P (code)
7713 || code == FLOAT_EXPR || code == ABS_EXPR || code == NEGATE_EXPR)
7715 /* Don't use STRIP_NOPS, because signedness of argument type
7716 matters. */
7717 STRIP_SIGN_NOPS (arg0);
7719 else
7721 /* Strip any conversions that don't change the mode. This
7722 is safe for every expression, except for a comparison
7723 expression because its signedness is derived from its
7724 operands.
7726 Note that this is done as an internal manipulation within
7727 the constant folder, in order to find the simplest
7728 representation of the arguments so that their form can be
7729 studied. In any cases, the appropriate type conversions
7730 should be put back in the tree that will get out of the
7731 constant folder. */
7732 STRIP_NOPS (arg0);
7735 if (CONSTANT_CLASS_P (arg0))
7737 tree tem = const_unop (code, type, arg0);
7738 if (tem)
7740 if (TREE_TYPE (tem) != type)
7741 tem = fold_convert_loc (loc, type, tem);
7742 return tem;
7747 tem = generic_simplify (loc, code, type, op0);
7748 if (tem)
7749 return tem;
7751 if (TREE_CODE_CLASS (code) == tcc_unary)
7753 if (TREE_CODE (arg0) == COMPOUND_EXPR)
7754 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
7755 fold_build1_loc (loc, code, type,
7756 fold_convert_loc (loc, TREE_TYPE (op0),
7757 TREE_OPERAND (arg0, 1))));
7758 else if (TREE_CODE (arg0) == COND_EXPR)
7760 tree arg01 = TREE_OPERAND (arg0, 1);
7761 tree arg02 = TREE_OPERAND (arg0, 2);
7762 if (! VOID_TYPE_P (TREE_TYPE (arg01)))
7763 arg01 = fold_build1_loc (loc, code, type,
7764 fold_convert_loc (loc,
7765 TREE_TYPE (op0), arg01));
7766 if (! VOID_TYPE_P (TREE_TYPE (arg02)))
7767 arg02 = fold_build1_loc (loc, code, type,
7768 fold_convert_loc (loc,
7769 TREE_TYPE (op0), arg02));
7770 tem = fold_build3_loc (loc, COND_EXPR, type, TREE_OPERAND (arg0, 0),
7771 arg01, arg02);
7773 /* If this was a conversion, and all we did was to move into
7774 inside the COND_EXPR, bring it back out. But leave it if
7775 it is a conversion from integer to integer and the
7776 result precision is no wider than a word since such a
7777 conversion is cheap and may be optimized away by combine,
7778 while it couldn't if it were outside the COND_EXPR. Then return
7779 so we don't get into an infinite recursion loop taking the
7780 conversion out and then back in. */
7782 if ((CONVERT_EXPR_CODE_P (code)
7783 || code == NON_LVALUE_EXPR)
7784 && TREE_CODE (tem) == COND_EXPR
7785 && TREE_CODE (TREE_OPERAND (tem, 1)) == code
7786 && TREE_CODE (TREE_OPERAND (tem, 2)) == code
7787 && ! VOID_TYPE_P (TREE_OPERAND (tem, 1))
7788 && ! VOID_TYPE_P (TREE_OPERAND (tem, 2))
7789 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))
7790 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 2), 0)))
7791 && (! (INTEGRAL_TYPE_P (TREE_TYPE (tem))
7792 && (INTEGRAL_TYPE_P
7793 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))))
7794 && TYPE_PRECISION (TREE_TYPE (tem)) <= BITS_PER_WORD)
7795 || flag_syntax_only))
7796 tem = build1_loc (loc, code, type,
7797 build3 (COND_EXPR,
7798 TREE_TYPE (TREE_OPERAND
7799 (TREE_OPERAND (tem, 1), 0)),
7800 TREE_OPERAND (tem, 0),
7801 TREE_OPERAND (TREE_OPERAND (tem, 1), 0),
7802 TREE_OPERAND (TREE_OPERAND (tem, 2),
7803 0)));
7804 return tem;
7808 switch (code)
7810 case NON_LVALUE_EXPR:
7811 if (!maybe_lvalue_p (op0))
7812 return fold_convert_loc (loc, type, op0);
7813 return NULL_TREE;
7815 CASE_CONVERT:
7816 case FLOAT_EXPR:
7817 case FIX_TRUNC_EXPR:
7818 if (COMPARISON_CLASS_P (op0))
7820 /* If we have (type) (a CMP b) and type is an integral type, return
7821 new expression involving the new type. Canonicalize
7822 (type) (a CMP b) to (a CMP b) ? (type) true : (type) false for
7823 non-integral type.
7824 Do not fold the result as that would not simplify further, also
7825 folding again results in recursions. */
7826 if (TREE_CODE (type) == BOOLEAN_TYPE)
7827 return build2_loc (loc, TREE_CODE (op0), type,
7828 TREE_OPERAND (op0, 0),
7829 TREE_OPERAND (op0, 1));
7830 else if (!INTEGRAL_TYPE_P (type) && !VOID_TYPE_P (type)
7831 && TREE_CODE (type) != VECTOR_TYPE)
7832 return build3_loc (loc, COND_EXPR, type, op0,
7833 constant_boolean_node (true, type),
7834 constant_boolean_node (false, type));
7837 /* Handle (T *)&A.B.C for A being of type T and B and C
7838 living at offset zero. This occurs frequently in
7839 C++ upcasting and then accessing the base. */
7840 if (TREE_CODE (op0) == ADDR_EXPR
7841 && POINTER_TYPE_P (type)
7842 && handled_component_p (TREE_OPERAND (op0, 0)))
7844 poly_int64 bitsize, bitpos;
7845 tree offset;
7846 machine_mode mode;
7847 int unsignedp, reversep, volatilep;
7848 tree base
7849 = get_inner_reference (TREE_OPERAND (op0, 0), &bitsize, &bitpos,
7850 &offset, &mode, &unsignedp, &reversep,
7851 &volatilep);
7852 /* If the reference was to a (constant) zero offset, we can use
7853 the address of the base if it has the same base type
7854 as the result type and the pointer type is unqualified. */
7855 if (!offset
7856 && known_eq (bitpos, 0)
7857 && (TYPE_MAIN_VARIANT (TREE_TYPE (type))
7858 == TYPE_MAIN_VARIANT (TREE_TYPE (base)))
7859 && TYPE_QUALS (type) == TYPE_UNQUALIFIED)
7860 return fold_convert_loc (loc, type,
7861 build_fold_addr_expr_loc (loc, base));
7864 if (TREE_CODE (op0) == MODIFY_EXPR
7865 && TREE_CONSTANT (TREE_OPERAND (op0, 1))
7866 /* Detect assigning a bitfield. */
7867 && !(TREE_CODE (TREE_OPERAND (op0, 0)) == COMPONENT_REF
7868 && DECL_BIT_FIELD
7869 (TREE_OPERAND (TREE_OPERAND (op0, 0), 1))))
7871 /* Don't leave an assignment inside a conversion
7872 unless assigning a bitfield. */
7873 tem = fold_build1_loc (loc, code, type, TREE_OPERAND (op0, 1));
7874 /* First do the assignment, then return converted constant. */
7875 tem = build2_loc (loc, COMPOUND_EXPR, TREE_TYPE (tem), op0, tem);
7876 TREE_NO_WARNING (tem) = 1;
7877 TREE_USED (tem) = 1;
7878 return tem;
7881 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
7882 constants (if x has signed type, the sign bit cannot be set
7883 in c). This folds extension into the BIT_AND_EXPR.
7884 ??? We don't do it for BOOLEAN_TYPE or ENUMERAL_TYPE because they
7885 very likely don't have maximal range for their precision and this
7886 transformation effectively doesn't preserve non-maximal ranges. */
7887 if (TREE_CODE (type) == INTEGER_TYPE
7888 && TREE_CODE (op0) == BIT_AND_EXPR
7889 && TREE_CODE (TREE_OPERAND (op0, 1)) == INTEGER_CST)
7891 tree and_expr = op0;
7892 tree and0 = TREE_OPERAND (and_expr, 0);
7893 tree and1 = TREE_OPERAND (and_expr, 1);
7894 int change = 0;
7896 if (TYPE_UNSIGNED (TREE_TYPE (and_expr))
7897 || (TYPE_PRECISION (type)
7898 <= TYPE_PRECISION (TREE_TYPE (and_expr))))
7899 change = 1;
7900 else if (TYPE_PRECISION (TREE_TYPE (and1))
7901 <= HOST_BITS_PER_WIDE_INT
7902 && tree_fits_uhwi_p (and1))
7904 unsigned HOST_WIDE_INT cst;
7906 cst = tree_to_uhwi (and1);
7907 cst &= HOST_WIDE_INT_M1U
7908 << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
7909 change = (cst == 0);
7910 if (change
7911 && !flag_syntax_only
7912 && (load_extend_op (TYPE_MODE (TREE_TYPE (and0)))
7913 == ZERO_EXTEND))
7915 tree uns = unsigned_type_for (TREE_TYPE (and0));
7916 and0 = fold_convert_loc (loc, uns, and0);
7917 and1 = fold_convert_loc (loc, uns, and1);
7920 if (change)
7922 tem = force_fit_type (type, wi::to_widest (and1), 0,
7923 TREE_OVERFLOW (and1));
7924 return fold_build2_loc (loc, BIT_AND_EXPR, type,
7925 fold_convert_loc (loc, type, and0), tem);
7929 /* Convert (T1)(X p+ Y) into ((T1)X p+ Y), for pointer type, when the new
7930 cast (T1)X will fold away. We assume that this happens when X itself
7931 is a cast. */
7932 if (POINTER_TYPE_P (type)
7933 && TREE_CODE (arg0) == POINTER_PLUS_EXPR
7934 && CONVERT_EXPR_P (TREE_OPERAND (arg0, 0)))
7936 tree arg00 = TREE_OPERAND (arg0, 0);
7937 tree arg01 = TREE_OPERAND (arg0, 1);
7939 return fold_build_pointer_plus_loc
7940 (loc, fold_convert_loc (loc, type, arg00), arg01);
7943 /* Convert (T1)(~(T2)X) into ~(T1)X if T1 and T2 are integral types
7944 of the same precision, and X is an integer type not narrower than
7945 types T1 or T2, i.e. the cast (T2)X isn't an extension. */
7946 if (INTEGRAL_TYPE_P (type)
7947 && TREE_CODE (op0) == BIT_NOT_EXPR
7948 && INTEGRAL_TYPE_P (TREE_TYPE (op0))
7949 && CONVERT_EXPR_P (TREE_OPERAND (op0, 0))
7950 && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (op0)))
7952 tem = TREE_OPERAND (TREE_OPERAND (op0, 0), 0);
7953 if (INTEGRAL_TYPE_P (TREE_TYPE (tem))
7954 && TYPE_PRECISION (type) <= TYPE_PRECISION (TREE_TYPE (tem)))
7955 return fold_build1_loc (loc, BIT_NOT_EXPR, type,
7956 fold_convert_loc (loc, type, tem));
7959 /* Convert (T1)(X * Y) into (T1)X * (T1)Y if T1 is narrower than the
7960 type of X and Y (integer types only). */
7961 if (INTEGRAL_TYPE_P (type)
7962 && TREE_CODE (op0) == MULT_EXPR
7963 && INTEGRAL_TYPE_P (TREE_TYPE (op0))
7964 && TYPE_PRECISION (type) < TYPE_PRECISION (TREE_TYPE (op0)))
7966 /* Be careful not to introduce new overflows. */
7967 tree mult_type;
7968 if (TYPE_OVERFLOW_WRAPS (type))
7969 mult_type = type;
7970 else
7971 mult_type = unsigned_type_for (type);
7973 if (TYPE_PRECISION (mult_type) < TYPE_PRECISION (TREE_TYPE (op0)))
7975 tem = fold_build2_loc (loc, MULT_EXPR, mult_type,
7976 fold_convert_loc (loc, mult_type,
7977 TREE_OPERAND (op0, 0)),
7978 fold_convert_loc (loc, mult_type,
7979 TREE_OPERAND (op0, 1)));
7980 return fold_convert_loc (loc, type, tem);
7984 return NULL_TREE;
7986 case VIEW_CONVERT_EXPR:
7987 if (TREE_CODE (op0) == MEM_REF)
7989 if (TYPE_ALIGN (TREE_TYPE (op0)) != TYPE_ALIGN (type))
7990 type = build_aligned_type (type, TYPE_ALIGN (TREE_TYPE (op0)));
7991 tem = fold_build2_loc (loc, MEM_REF, type,
7992 TREE_OPERAND (op0, 0), TREE_OPERAND (op0, 1));
7993 REF_REVERSE_STORAGE_ORDER (tem) = REF_REVERSE_STORAGE_ORDER (op0);
7994 return tem;
7997 return NULL_TREE;
7999 case NEGATE_EXPR:
8000 tem = fold_negate_expr (loc, arg0);
8001 if (tem)
8002 return fold_convert_loc (loc, type, tem);
8003 return NULL_TREE;
8005 case ABS_EXPR:
8006 /* Convert fabs((double)float) into (double)fabsf(float). */
8007 if (TREE_CODE (arg0) == NOP_EXPR
8008 && TREE_CODE (type) == REAL_TYPE)
8010 tree targ0 = strip_float_extensions (arg0);
8011 if (targ0 != arg0)
8012 return fold_convert_loc (loc, type,
8013 fold_build1_loc (loc, ABS_EXPR,
8014 TREE_TYPE (targ0),
8015 targ0));
8017 return NULL_TREE;
8019 case BIT_NOT_EXPR:
8020 /* Convert ~(X ^ Y) to ~X ^ Y or X ^ ~Y if ~X or ~Y simplify. */
8021 if (TREE_CODE (arg0) == BIT_XOR_EXPR
8022 && (tem = fold_unary_loc (loc, BIT_NOT_EXPR, type,
8023 fold_convert_loc (loc, type,
8024 TREE_OPERAND (arg0, 0)))))
8025 return fold_build2_loc (loc, BIT_XOR_EXPR, type, tem,
8026 fold_convert_loc (loc, type,
8027 TREE_OPERAND (arg0, 1)));
8028 else if (TREE_CODE (arg0) == BIT_XOR_EXPR
8029 && (tem = fold_unary_loc (loc, BIT_NOT_EXPR, type,
8030 fold_convert_loc (loc, type,
8031 TREE_OPERAND (arg0, 1)))))
8032 return fold_build2_loc (loc, BIT_XOR_EXPR, type,
8033 fold_convert_loc (loc, type,
8034 TREE_OPERAND (arg0, 0)), tem);
8036 return NULL_TREE;
8038 case TRUTH_NOT_EXPR:
8039 /* Note that the operand of this must be an int
8040 and its values must be 0 or 1.
8041 ("true" is a fixed value perhaps depending on the language,
8042 but we don't handle values other than 1 correctly yet.) */
8043 tem = fold_truth_not_expr (loc, arg0);
8044 if (!tem)
8045 return NULL_TREE;
8046 return fold_convert_loc (loc, type, tem);
8048 case INDIRECT_REF:
8049 /* Fold *&X to X if X is an lvalue. */
8050 if (TREE_CODE (op0) == ADDR_EXPR)
8052 tree op00 = TREE_OPERAND (op0, 0);
8053 if ((VAR_P (op00)
8054 || TREE_CODE (op00) == PARM_DECL
8055 || TREE_CODE (op00) == RESULT_DECL)
8056 && !TREE_READONLY (op00))
8057 return op00;
8059 return NULL_TREE;
8061 default:
8062 return NULL_TREE;
8063 } /* switch (code) */
8067 /* If the operation was a conversion do _not_ mark a resulting constant
8068 with TREE_OVERFLOW if the original constant was not. These conversions
8069 have implementation defined behavior and retaining the TREE_OVERFLOW
8070 flag here would confuse later passes such as VRP. */
8071 tree
8072 fold_unary_ignore_overflow_loc (location_t loc, enum tree_code code,
8073 tree type, tree op0)
8075 tree res = fold_unary_loc (loc, code, type, op0);
8076 if (res
8077 && TREE_CODE (res) == INTEGER_CST
8078 && TREE_CODE (op0) == INTEGER_CST
8079 && CONVERT_EXPR_CODE_P (code))
8080 TREE_OVERFLOW (res) = TREE_OVERFLOW (op0);
8082 return res;
8085 /* Fold a binary bitwise/truth expression of code CODE and type TYPE with
8086 operands OP0 and OP1. LOC is the location of the resulting expression.
8087 ARG0 and ARG1 are the NOP_STRIPed results of OP0 and OP1.
8088 Return the folded expression if folding is successful. Otherwise,
8089 return NULL_TREE. */
8090 static tree
8091 fold_truth_andor (location_t loc, enum tree_code code, tree type,
8092 tree arg0, tree arg1, tree op0, tree op1)
8094 tree tem;
8096 /* We only do these simplifications if we are optimizing. */
8097 if (!optimize)
8098 return NULL_TREE;
8100 /* Check for things like (A || B) && (A || C). We can convert this
8101 to A || (B && C). Note that either operator can be any of the four
8102 truth and/or operations and the transformation will still be
8103 valid. Also note that we only care about order for the
8104 ANDIF and ORIF operators. If B contains side effects, this
8105 might change the truth-value of A. */
8106 if (TREE_CODE (arg0) == TREE_CODE (arg1)
8107 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
8108 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
8109 || TREE_CODE (arg0) == TRUTH_AND_EXPR
8110 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
8111 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
8113 tree a00 = TREE_OPERAND (arg0, 0);
8114 tree a01 = TREE_OPERAND (arg0, 1);
8115 tree a10 = TREE_OPERAND (arg1, 0);
8116 tree a11 = TREE_OPERAND (arg1, 1);
8117 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
8118 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
8119 && (code == TRUTH_AND_EXPR
8120 || code == TRUTH_OR_EXPR));
8122 if (operand_equal_p (a00, a10, 0))
8123 return fold_build2_loc (loc, TREE_CODE (arg0), type, a00,
8124 fold_build2_loc (loc, code, type, a01, a11));
8125 else if (commutative && operand_equal_p (a00, a11, 0))
8126 return fold_build2_loc (loc, TREE_CODE (arg0), type, a00,
8127 fold_build2_loc (loc, code, type, a01, a10));
8128 else if (commutative && operand_equal_p (a01, a10, 0))
8129 return fold_build2_loc (loc, TREE_CODE (arg0), type, a01,
8130 fold_build2_loc (loc, code, type, a00, a11));
8132 /* This case if tricky because we must either have commutative
8133 operators or else A10 must not have side-effects. */
8135 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
8136 && operand_equal_p (a01, a11, 0))
8137 return fold_build2_loc (loc, TREE_CODE (arg0), type,
8138 fold_build2_loc (loc, code, type, a00, a10),
8139 a01);
8142 /* See if we can build a range comparison. */
8143 if ((tem = fold_range_test (loc, code, type, op0, op1)) != 0)
8144 return tem;
8146 if ((code == TRUTH_ANDIF_EXPR && TREE_CODE (arg0) == TRUTH_ORIF_EXPR)
8147 || (code == TRUTH_ORIF_EXPR && TREE_CODE (arg0) == TRUTH_ANDIF_EXPR))
8149 tem = merge_truthop_with_opposite_arm (loc, arg0, arg1, true);
8150 if (tem)
8151 return fold_build2_loc (loc, code, type, tem, arg1);
8154 if ((code == TRUTH_ANDIF_EXPR && TREE_CODE (arg1) == TRUTH_ORIF_EXPR)
8155 || (code == TRUTH_ORIF_EXPR && TREE_CODE (arg1) == TRUTH_ANDIF_EXPR))
8157 tem = merge_truthop_with_opposite_arm (loc, arg1, arg0, false);
8158 if (tem)
8159 return fold_build2_loc (loc, code, type, arg0, tem);
8162 /* Check for the possibility of merging component references. If our
8163 lhs is another similar operation, try to merge its rhs with our
8164 rhs. Then try to merge our lhs and rhs. */
8165 if (TREE_CODE (arg0) == code
8166 && (tem = fold_truth_andor_1 (loc, code, type,
8167 TREE_OPERAND (arg0, 1), arg1)) != 0)
8168 return fold_build2_loc (loc, code, type, TREE_OPERAND (arg0, 0), tem);
8170 if ((tem = fold_truth_andor_1 (loc, code, type, arg0, arg1)) != 0)
8171 return tem;
8173 if (LOGICAL_OP_NON_SHORT_CIRCUIT
8174 && !flag_sanitize_coverage
8175 && (code == TRUTH_AND_EXPR
8176 || code == TRUTH_ANDIF_EXPR
8177 || code == TRUTH_OR_EXPR
8178 || code == TRUTH_ORIF_EXPR))
8180 enum tree_code ncode, icode;
8182 ncode = (code == TRUTH_ANDIF_EXPR || code == TRUTH_AND_EXPR)
8183 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR;
8184 icode = ncode == TRUTH_AND_EXPR ? TRUTH_ANDIF_EXPR : TRUTH_ORIF_EXPR;
8186 /* Transform ((A AND-IF B) AND[-IF] C) into (A AND-IF (B AND C)),
8187 or ((A OR-IF B) OR[-IF] C) into (A OR-IF (B OR C))
8188 We don't want to pack more than two leafs to a non-IF AND/OR
8189 expression.
8190 If tree-code of left-hand operand isn't an AND/OR-IF code and not
8191 equal to IF-CODE, then we don't want to add right-hand operand.
8192 If the inner right-hand side of left-hand operand has
8193 side-effects, or isn't simple, then we can't add to it,
8194 as otherwise we might destroy if-sequence. */
8195 if (TREE_CODE (arg0) == icode
8196 && simple_operand_p_2 (arg1)
8197 /* Needed for sequence points to handle trappings, and
8198 side-effects. */
8199 && simple_operand_p_2 (TREE_OPERAND (arg0, 1)))
8201 tem = fold_build2_loc (loc, ncode, type, TREE_OPERAND (arg0, 1),
8202 arg1);
8203 return fold_build2_loc (loc, icode, type, TREE_OPERAND (arg0, 0),
8204 tem);
8206 /* Same as above but for (A AND[-IF] (B AND-IF C)) -> ((A AND B) AND-IF C),
8207 or (A OR[-IF] (B OR-IF C) -> ((A OR B) OR-IF C). */
8208 else if (TREE_CODE (arg1) == icode
8209 && simple_operand_p_2 (arg0)
8210 /* Needed for sequence points to handle trappings, and
8211 side-effects. */
8212 && simple_operand_p_2 (TREE_OPERAND (arg1, 0)))
8214 tem = fold_build2_loc (loc, ncode, type,
8215 arg0, TREE_OPERAND (arg1, 0));
8216 return fold_build2_loc (loc, icode, type, tem,
8217 TREE_OPERAND (arg1, 1));
8219 /* Transform (A AND-IF B) into (A AND B), or (A OR-IF B)
8220 into (A OR B).
8221 For sequence point consistancy, we need to check for trapping,
8222 and side-effects. */
8223 else if (code == icode && simple_operand_p_2 (arg0)
8224 && simple_operand_p_2 (arg1))
8225 return fold_build2_loc (loc, ncode, type, arg0, arg1);
8228 return NULL_TREE;
8231 /* Helper that tries to canonicalize the comparison ARG0 CODE ARG1
8232 by changing CODE to reduce the magnitude of constants involved in
8233 ARG0 of the comparison.
8234 Returns a canonicalized comparison tree if a simplification was
8235 possible, otherwise returns NULL_TREE.
8236 Set *STRICT_OVERFLOW_P to true if the canonicalization is only
8237 valid if signed overflow is undefined. */
8239 static tree
8240 maybe_canonicalize_comparison_1 (location_t loc, enum tree_code code, tree type,
8241 tree arg0, tree arg1,
8242 bool *strict_overflow_p)
8244 enum tree_code code0 = TREE_CODE (arg0);
8245 tree t, cst0 = NULL_TREE;
8246 int sgn0;
8248 /* Match A +- CST code arg1. We can change this only if overflow
8249 is undefined. */
8250 if (!((ANY_INTEGRAL_TYPE_P (TREE_TYPE (arg0))
8251 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0)))
8252 /* In principle pointers also have undefined overflow behavior,
8253 but that causes problems elsewhere. */
8254 && !POINTER_TYPE_P (TREE_TYPE (arg0))
8255 && (code0 == MINUS_EXPR
8256 || code0 == PLUS_EXPR)
8257 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST))
8258 return NULL_TREE;
8260 /* Identify the constant in arg0 and its sign. */
8261 cst0 = TREE_OPERAND (arg0, 1);
8262 sgn0 = tree_int_cst_sgn (cst0);
8264 /* Overflowed constants and zero will cause problems. */
8265 if (integer_zerop (cst0)
8266 || TREE_OVERFLOW (cst0))
8267 return NULL_TREE;
8269 /* See if we can reduce the magnitude of the constant in
8270 arg0 by changing the comparison code. */
8271 /* A - CST < arg1 -> A - CST-1 <= arg1. */
8272 if (code == LT_EXPR
8273 && code0 == ((sgn0 == -1) ? PLUS_EXPR : MINUS_EXPR))
8274 code = LE_EXPR;
8275 /* A + CST > arg1 -> A + CST-1 >= arg1. */
8276 else if (code == GT_EXPR
8277 && code0 == ((sgn0 == -1) ? MINUS_EXPR : PLUS_EXPR))
8278 code = GE_EXPR;
8279 /* A + CST <= arg1 -> A + CST-1 < arg1. */
8280 else if (code == LE_EXPR
8281 && code0 == ((sgn0 == -1) ? MINUS_EXPR : PLUS_EXPR))
8282 code = LT_EXPR;
8283 /* A - CST >= arg1 -> A - CST-1 > arg1. */
8284 else if (code == GE_EXPR
8285 && code0 == ((sgn0 == -1) ? PLUS_EXPR : MINUS_EXPR))
8286 code = GT_EXPR;
8287 else
8288 return NULL_TREE;
8289 *strict_overflow_p = true;
8291 /* Now build the constant reduced in magnitude. But not if that
8292 would produce one outside of its types range. */
8293 if (INTEGRAL_TYPE_P (TREE_TYPE (cst0))
8294 && ((sgn0 == 1
8295 && TYPE_MIN_VALUE (TREE_TYPE (cst0))
8296 && tree_int_cst_equal (cst0, TYPE_MIN_VALUE (TREE_TYPE (cst0))))
8297 || (sgn0 == -1
8298 && TYPE_MAX_VALUE (TREE_TYPE (cst0))
8299 && tree_int_cst_equal (cst0, TYPE_MAX_VALUE (TREE_TYPE (cst0))))))
8300 return NULL_TREE;
8302 t = int_const_binop (sgn0 == -1 ? PLUS_EXPR : MINUS_EXPR,
8303 cst0, build_int_cst (TREE_TYPE (cst0), 1));
8304 t = fold_build2_loc (loc, code0, TREE_TYPE (arg0), TREE_OPERAND (arg0, 0), t);
8305 t = fold_convert (TREE_TYPE (arg1), t);
8307 return fold_build2_loc (loc, code, type, t, arg1);
8310 /* Canonicalize the comparison ARG0 CODE ARG1 with type TYPE with undefined
8311 overflow further. Try to decrease the magnitude of constants involved
8312 by changing LE_EXPR and GE_EXPR to LT_EXPR and GT_EXPR or vice versa
8313 and put sole constants at the second argument position.
8314 Returns the canonicalized tree if changed, otherwise NULL_TREE. */
8316 static tree
8317 maybe_canonicalize_comparison (location_t loc, enum tree_code code, tree type,
8318 tree arg0, tree arg1)
8320 tree t;
8321 bool strict_overflow_p;
8322 const char * const warnmsg = G_("assuming signed overflow does not occur "
8323 "when reducing constant in comparison");
8325 /* Try canonicalization by simplifying arg0. */
8326 strict_overflow_p = false;
8327 t = maybe_canonicalize_comparison_1 (loc, code, type, arg0, arg1,
8328 &strict_overflow_p);
8329 if (t)
8331 if (strict_overflow_p)
8332 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MAGNITUDE);
8333 return t;
8336 /* Try canonicalization by simplifying arg1 using the swapped
8337 comparison. */
8338 code = swap_tree_comparison (code);
8339 strict_overflow_p = false;
8340 t = maybe_canonicalize_comparison_1 (loc, code, type, arg1, arg0,
8341 &strict_overflow_p);
8342 if (t && strict_overflow_p)
8343 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MAGNITUDE);
8344 return t;
8347 /* Return whether BASE + OFFSET + BITPOS may wrap around the address
8348 space. This is used to avoid issuing overflow warnings for
8349 expressions like &p->x which can not wrap. */
8351 static bool
8352 pointer_may_wrap_p (tree base, tree offset, poly_int64 bitpos)
8354 if (!POINTER_TYPE_P (TREE_TYPE (base)))
8355 return true;
8357 if (maybe_lt (bitpos, 0))
8358 return true;
8360 poly_wide_int wi_offset;
8361 int precision = TYPE_PRECISION (TREE_TYPE (base));
8362 if (offset == NULL_TREE)
8363 wi_offset = wi::zero (precision);
8364 else if (!poly_int_tree_p (offset) || TREE_OVERFLOW (offset))
8365 return true;
8366 else
8367 wi_offset = wi::to_poly_wide (offset);
8369 bool overflow;
8370 poly_wide_int units = wi::shwi (bits_to_bytes_round_down (bitpos),
8371 precision);
8372 poly_wide_int total = wi::add (wi_offset, units, UNSIGNED, &overflow);
8373 if (overflow)
8374 return true;
8376 poly_uint64 total_hwi, size;
8377 if (!total.to_uhwi (&total_hwi)
8378 || !poly_int_tree_p (TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (base))),
8379 &size)
8380 || known_eq (size, 0U))
8381 return true;
8383 if (known_le (total_hwi, size))
8384 return false;
8386 /* We can do slightly better for SIZE if we have an ADDR_EXPR of an
8387 array. */
8388 if (TREE_CODE (base) == ADDR_EXPR
8389 && poly_int_tree_p (TYPE_SIZE_UNIT (TREE_TYPE (TREE_OPERAND (base, 0))),
8390 &size)
8391 && maybe_ne (size, 0U)
8392 && known_le (total_hwi, size))
8393 return false;
8395 return true;
8398 /* Return a positive integer when the symbol DECL is known to have
8399 a nonzero address, zero when it's known not to (e.g., it's a weak
8400 symbol), and a negative integer when the symbol is not yet in the
8401 symbol table and so whether or not its address is zero is unknown.
8402 For function local objects always return positive integer. */
8403 static int
8404 maybe_nonzero_address (tree decl)
8406 if (DECL_P (decl) && decl_in_symtab_p (decl))
8407 if (struct symtab_node *symbol = symtab_node::get_create (decl))
8408 return symbol->nonzero_address ();
8410 /* Function local objects are never NULL. */
8411 if (DECL_P (decl)
8412 && (DECL_CONTEXT (decl)
8413 && TREE_CODE (DECL_CONTEXT (decl)) == FUNCTION_DECL
8414 && auto_var_in_fn_p (decl, DECL_CONTEXT (decl))))
8415 return 1;
8417 return -1;
8420 /* Subroutine of fold_binary. This routine performs all of the
8421 transformations that are common to the equality/inequality
8422 operators (EQ_EXPR and NE_EXPR) and the ordering operators
8423 (LT_EXPR, LE_EXPR, GE_EXPR and GT_EXPR). Callers other than
8424 fold_binary should call fold_binary. Fold a comparison with
8425 tree code CODE and type TYPE with operands OP0 and OP1. Return
8426 the folded comparison or NULL_TREE. */
8428 static tree
8429 fold_comparison (location_t loc, enum tree_code code, tree type,
8430 tree op0, tree op1)
8432 const bool equality_code = (code == EQ_EXPR || code == NE_EXPR);
8433 tree arg0, arg1, tem;
8435 arg0 = op0;
8436 arg1 = op1;
8438 STRIP_SIGN_NOPS (arg0);
8439 STRIP_SIGN_NOPS (arg1);
8441 /* For comparisons of pointers we can decompose it to a compile time
8442 comparison of the base objects and the offsets into the object.
8443 This requires at least one operand being an ADDR_EXPR or a
8444 POINTER_PLUS_EXPR to do more than the operand_equal_p test below. */
8445 if (POINTER_TYPE_P (TREE_TYPE (arg0))
8446 && (TREE_CODE (arg0) == ADDR_EXPR
8447 || TREE_CODE (arg1) == ADDR_EXPR
8448 || TREE_CODE (arg0) == POINTER_PLUS_EXPR
8449 || TREE_CODE (arg1) == POINTER_PLUS_EXPR))
8451 tree base0, base1, offset0 = NULL_TREE, offset1 = NULL_TREE;
8452 poly_int64 bitsize, bitpos0 = 0, bitpos1 = 0;
8453 machine_mode mode;
8454 int volatilep, reversep, unsignedp;
8455 bool indirect_base0 = false, indirect_base1 = false;
8457 /* Get base and offset for the access. Strip ADDR_EXPR for
8458 get_inner_reference, but put it back by stripping INDIRECT_REF
8459 off the base object if possible. indirect_baseN will be true
8460 if baseN is not an address but refers to the object itself. */
8461 base0 = arg0;
8462 if (TREE_CODE (arg0) == ADDR_EXPR)
8464 base0
8465 = get_inner_reference (TREE_OPERAND (arg0, 0),
8466 &bitsize, &bitpos0, &offset0, &mode,
8467 &unsignedp, &reversep, &volatilep);
8468 if (TREE_CODE (base0) == INDIRECT_REF)
8469 base0 = TREE_OPERAND (base0, 0);
8470 else
8471 indirect_base0 = true;
8473 else if (TREE_CODE (arg0) == POINTER_PLUS_EXPR)
8475 base0 = TREE_OPERAND (arg0, 0);
8476 STRIP_SIGN_NOPS (base0);
8477 if (TREE_CODE (base0) == ADDR_EXPR)
8479 base0
8480 = get_inner_reference (TREE_OPERAND (base0, 0),
8481 &bitsize, &bitpos0, &offset0, &mode,
8482 &unsignedp, &reversep, &volatilep);
8483 if (TREE_CODE (base0) == INDIRECT_REF)
8484 base0 = TREE_OPERAND (base0, 0);
8485 else
8486 indirect_base0 = true;
8488 if (offset0 == NULL_TREE || integer_zerop (offset0))
8489 offset0 = TREE_OPERAND (arg0, 1);
8490 else
8491 offset0 = size_binop (PLUS_EXPR, offset0,
8492 TREE_OPERAND (arg0, 1));
8493 if (poly_int_tree_p (offset0))
8495 poly_offset_int tem = wi::sext (wi::to_poly_offset (offset0),
8496 TYPE_PRECISION (sizetype));
8497 tem <<= LOG2_BITS_PER_UNIT;
8498 tem += bitpos0;
8499 if (tem.to_shwi (&bitpos0))
8500 offset0 = NULL_TREE;
8504 base1 = arg1;
8505 if (TREE_CODE (arg1) == ADDR_EXPR)
8507 base1
8508 = get_inner_reference (TREE_OPERAND (arg1, 0),
8509 &bitsize, &bitpos1, &offset1, &mode,
8510 &unsignedp, &reversep, &volatilep);
8511 if (TREE_CODE (base1) == INDIRECT_REF)
8512 base1 = TREE_OPERAND (base1, 0);
8513 else
8514 indirect_base1 = true;
8516 else if (TREE_CODE (arg1) == POINTER_PLUS_EXPR)
8518 base1 = TREE_OPERAND (arg1, 0);
8519 STRIP_SIGN_NOPS (base1);
8520 if (TREE_CODE (base1) == ADDR_EXPR)
8522 base1
8523 = get_inner_reference (TREE_OPERAND (base1, 0),
8524 &bitsize, &bitpos1, &offset1, &mode,
8525 &unsignedp, &reversep, &volatilep);
8526 if (TREE_CODE (base1) == INDIRECT_REF)
8527 base1 = TREE_OPERAND (base1, 0);
8528 else
8529 indirect_base1 = true;
8531 if (offset1 == NULL_TREE || integer_zerop (offset1))
8532 offset1 = TREE_OPERAND (arg1, 1);
8533 else
8534 offset1 = size_binop (PLUS_EXPR, offset1,
8535 TREE_OPERAND (arg1, 1));
8536 if (poly_int_tree_p (offset1))
8538 poly_offset_int tem = wi::sext (wi::to_poly_offset (offset1),
8539 TYPE_PRECISION (sizetype));
8540 tem <<= LOG2_BITS_PER_UNIT;
8541 tem += bitpos1;
8542 if (tem.to_shwi (&bitpos1))
8543 offset1 = NULL_TREE;
8547 /* If we have equivalent bases we might be able to simplify. */
8548 if (indirect_base0 == indirect_base1
8549 && operand_equal_p (base0, base1,
8550 indirect_base0 ? OEP_ADDRESS_OF : 0))
8552 /* We can fold this expression to a constant if the non-constant
8553 offset parts are equal. */
8554 if ((offset0 == offset1
8555 || (offset0 && offset1
8556 && operand_equal_p (offset0, offset1, 0)))
8557 && (equality_code
8558 || (indirect_base0
8559 && (DECL_P (base0) || CONSTANT_CLASS_P (base0)))
8560 || TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))))
8562 if (!equality_code
8563 && maybe_ne (bitpos0, bitpos1)
8564 && (pointer_may_wrap_p (base0, offset0, bitpos0)
8565 || pointer_may_wrap_p (base1, offset1, bitpos1)))
8566 fold_overflow_warning (("assuming pointer wraparound does not "
8567 "occur when comparing P +- C1 with "
8568 "P +- C2"),
8569 WARN_STRICT_OVERFLOW_CONDITIONAL);
8571 switch (code)
8573 case EQ_EXPR:
8574 if (known_eq (bitpos0, bitpos1))
8575 return constant_boolean_node (true, type);
8576 if (known_ne (bitpos0, bitpos1))
8577 return constant_boolean_node (false, type);
8578 break;
8579 case NE_EXPR:
8580 if (known_ne (bitpos0, bitpos1))
8581 return constant_boolean_node (true, type);
8582 if (known_eq (bitpos0, bitpos1))
8583 return constant_boolean_node (false, type);
8584 break;
8585 case LT_EXPR:
8586 if (known_lt (bitpos0, bitpos1))
8587 return constant_boolean_node (true, type);
8588 if (known_ge (bitpos0, bitpos1))
8589 return constant_boolean_node (false, type);
8590 break;
8591 case LE_EXPR:
8592 if (known_le (bitpos0, bitpos1))
8593 return constant_boolean_node (true, type);
8594 if (known_gt (bitpos0, bitpos1))
8595 return constant_boolean_node (false, type);
8596 break;
8597 case GE_EXPR:
8598 if (known_ge (bitpos0, bitpos1))
8599 return constant_boolean_node (true, type);
8600 if (known_lt (bitpos0, bitpos1))
8601 return constant_boolean_node (false, type);
8602 break;
8603 case GT_EXPR:
8604 if (known_gt (bitpos0, bitpos1))
8605 return constant_boolean_node (true, type);
8606 if (known_le (bitpos0, bitpos1))
8607 return constant_boolean_node (false, type);
8608 break;
8609 default:;
8612 /* We can simplify the comparison to a comparison of the variable
8613 offset parts if the constant offset parts are equal.
8614 Be careful to use signed sizetype here because otherwise we
8615 mess with array offsets in the wrong way. This is possible
8616 because pointer arithmetic is restricted to retain within an
8617 object and overflow on pointer differences is undefined as of
8618 6.5.6/8 and /9 with respect to the signed ptrdiff_t. */
8619 else if (known_eq (bitpos0, bitpos1)
8620 && (equality_code
8621 || (indirect_base0
8622 && (DECL_P (base0) || CONSTANT_CLASS_P (base0)))
8623 || TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))))
8625 /* By converting to signed sizetype we cover middle-end pointer
8626 arithmetic which operates on unsigned pointer types of size
8627 type size and ARRAY_REF offsets which are properly sign or
8628 zero extended from their type in case it is narrower than
8629 sizetype. */
8630 if (offset0 == NULL_TREE)
8631 offset0 = build_int_cst (ssizetype, 0);
8632 else
8633 offset0 = fold_convert_loc (loc, ssizetype, offset0);
8634 if (offset1 == NULL_TREE)
8635 offset1 = build_int_cst (ssizetype, 0);
8636 else
8637 offset1 = fold_convert_loc (loc, ssizetype, offset1);
8639 if (!equality_code
8640 && (pointer_may_wrap_p (base0, offset0, bitpos0)
8641 || pointer_may_wrap_p (base1, offset1, bitpos1)))
8642 fold_overflow_warning (("assuming pointer wraparound does not "
8643 "occur when comparing P +- C1 with "
8644 "P +- C2"),
8645 WARN_STRICT_OVERFLOW_COMPARISON);
8647 return fold_build2_loc (loc, code, type, offset0, offset1);
8650 /* For equal offsets we can simplify to a comparison of the
8651 base addresses. */
8652 else if (known_eq (bitpos0, bitpos1)
8653 && (indirect_base0
8654 ? base0 != TREE_OPERAND (arg0, 0) : base0 != arg0)
8655 && (indirect_base1
8656 ? base1 != TREE_OPERAND (arg1, 0) : base1 != arg1)
8657 && ((offset0 == offset1)
8658 || (offset0 && offset1
8659 && operand_equal_p (offset0, offset1, 0))))
8661 if (indirect_base0)
8662 base0 = build_fold_addr_expr_loc (loc, base0);
8663 if (indirect_base1)
8664 base1 = build_fold_addr_expr_loc (loc, base1);
8665 return fold_build2_loc (loc, code, type, base0, base1);
8667 /* Comparison between an ordinary (non-weak) symbol and a null
8668 pointer can be eliminated since such symbols must have a non
8669 null address. In C, relational expressions between pointers
8670 to objects and null pointers are undefined. The results
8671 below follow the C++ rules with the additional property that
8672 every object pointer compares greater than a null pointer.
8674 else if (((DECL_P (base0)
8675 && maybe_nonzero_address (base0) > 0
8676 /* Avoid folding references to struct members at offset 0 to
8677 prevent tests like '&ptr->firstmember == 0' from getting
8678 eliminated. When ptr is null, although the -> expression
8679 is strictly speaking invalid, GCC retains it as a matter
8680 of QoI. See PR c/44555. */
8681 && (offset0 == NULL_TREE && known_ne (bitpos0, 0)))
8682 || CONSTANT_CLASS_P (base0))
8683 && indirect_base0
8684 /* The caller guarantees that when one of the arguments is
8685 constant (i.e., null in this case) it is second. */
8686 && integer_zerop (arg1))
8688 switch (code)
8690 case EQ_EXPR:
8691 case LE_EXPR:
8692 case LT_EXPR:
8693 return constant_boolean_node (false, type);
8694 case GE_EXPR:
8695 case GT_EXPR:
8696 case NE_EXPR:
8697 return constant_boolean_node (true, type);
8698 default:
8699 gcc_unreachable ();
8704 /* Transform comparisons of the form X +- C1 CMP Y +- C2 to
8705 X CMP Y +- C2 +- C1 for signed X, Y. This is valid if
8706 the resulting offset is smaller in absolute value than the
8707 original one and has the same sign. */
8708 if (ANY_INTEGRAL_TYPE_P (TREE_TYPE (arg0))
8709 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))
8710 && (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8711 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8712 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1)))
8713 && (TREE_CODE (arg1) == PLUS_EXPR || TREE_CODE (arg1) == MINUS_EXPR)
8714 && (TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
8715 && !TREE_OVERFLOW (TREE_OPERAND (arg1, 1))))
8717 tree const1 = TREE_OPERAND (arg0, 1);
8718 tree const2 = TREE_OPERAND (arg1, 1);
8719 tree variable1 = TREE_OPERAND (arg0, 0);
8720 tree variable2 = TREE_OPERAND (arg1, 0);
8721 tree cst;
8722 const char * const warnmsg = G_("assuming signed overflow does not "
8723 "occur when combining constants around "
8724 "a comparison");
8726 /* Put the constant on the side where it doesn't overflow and is
8727 of lower absolute value and of same sign than before. */
8728 cst = int_const_binop (TREE_CODE (arg0) == TREE_CODE (arg1)
8729 ? MINUS_EXPR : PLUS_EXPR,
8730 const2, const1);
8731 if (!TREE_OVERFLOW (cst)
8732 && tree_int_cst_compare (const2, cst) == tree_int_cst_sgn (const2)
8733 && tree_int_cst_sgn (cst) == tree_int_cst_sgn (const2))
8735 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
8736 return fold_build2_loc (loc, code, type,
8737 variable1,
8738 fold_build2_loc (loc, TREE_CODE (arg1),
8739 TREE_TYPE (arg1),
8740 variable2, cst));
8743 cst = int_const_binop (TREE_CODE (arg0) == TREE_CODE (arg1)
8744 ? MINUS_EXPR : PLUS_EXPR,
8745 const1, const2);
8746 if (!TREE_OVERFLOW (cst)
8747 && tree_int_cst_compare (const1, cst) == tree_int_cst_sgn (const1)
8748 && tree_int_cst_sgn (cst) == tree_int_cst_sgn (const1))
8750 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
8751 return fold_build2_loc (loc, code, type,
8752 fold_build2_loc (loc, TREE_CODE (arg0),
8753 TREE_TYPE (arg0),
8754 variable1, cst),
8755 variable2);
8759 tem = maybe_canonicalize_comparison (loc, code, type, arg0, arg1);
8760 if (tem)
8761 return tem;
8763 /* If we are comparing an expression that just has comparisons
8764 of two integer values, arithmetic expressions of those comparisons,
8765 and constants, we can simplify it. There are only three cases
8766 to check: the two values can either be equal, the first can be
8767 greater, or the second can be greater. Fold the expression for
8768 those three values. Since each value must be 0 or 1, we have
8769 eight possibilities, each of which corresponds to the constant 0
8770 or 1 or one of the six possible comparisons.
8772 This handles common cases like (a > b) == 0 but also handles
8773 expressions like ((x > y) - (y > x)) > 0, which supposedly
8774 occur in macroized code. */
8776 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
8778 tree cval1 = 0, cval2 = 0;
8779 int save_p = 0;
8781 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
8782 /* Don't handle degenerate cases here; they should already
8783 have been handled anyway. */
8784 && cval1 != 0 && cval2 != 0
8785 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
8786 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
8787 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
8788 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
8789 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
8790 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
8791 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
8793 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
8794 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
8796 /* We can't just pass T to eval_subst in case cval1 or cval2
8797 was the same as ARG1. */
8799 tree high_result
8800 = fold_build2_loc (loc, code, type,
8801 eval_subst (loc, arg0, cval1, maxval,
8802 cval2, minval),
8803 arg1);
8804 tree equal_result
8805 = fold_build2_loc (loc, code, type,
8806 eval_subst (loc, arg0, cval1, maxval,
8807 cval2, maxval),
8808 arg1);
8809 tree low_result
8810 = fold_build2_loc (loc, code, type,
8811 eval_subst (loc, arg0, cval1, minval,
8812 cval2, maxval),
8813 arg1);
8815 /* All three of these results should be 0 or 1. Confirm they are.
8816 Then use those values to select the proper code to use. */
8818 if (TREE_CODE (high_result) == INTEGER_CST
8819 && TREE_CODE (equal_result) == INTEGER_CST
8820 && TREE_CODE (low_result) == INTEGER_CST)
8822 /* Make a 3-bit mask with the high-order bit being the
8823 value for `>', the next for '=', and the low for '<'. */
8824 switch ((integer_onep (high_result) * 4)
8825 + (integer_onep (equal_result) * 2)
8826 + integer_onep (low_result))
8828 case 0:
8829 /* Always false. */
8830 return omit_one_operand_loc (loc, type, integer_zero_node, arg0);
8831 case 1:
8832 code = LT_EXPR;
8833 break;
8834 case 2:
8835 code = EQ_EXPR;
8836 break;
8837 case 3:
8838 code = LE_EXPR;
8839 break;
8840 case 4:
8841 code = GT_EXPR;
8842 break;
8843 case 5:
8844 code = NE_EXPR;
8845 break;
8846 case 6:
8847 code = GE_EXPR;
8848 break;
8849 case 7:
8850 /* Always true. */
8851 return omit_one_operand_loc (loc, type, integer_one_node, arg0);
8854 if (save_p)
8856 tem = save_expr (build2 (code, type, cval1, cval2));
8857 protected_set_expr_location (tem, loc);
8858 return tem;
8860 return fold_build2_loc (loc, code, type, cval1, cval2);
8865 return NULL_TREE;
8869 /* Subroutine of fold_binary. Optimize complex multiplications of the
8870 form z * conj(z), as pow(realpart(z),2) + pow(imagpart(z),2). The
8871 argument EXPR represents the expression "z" of type TYPE. */
8873 static tree
8874 fold_mult_zconjz (location_t loc, tree type, tree expr)
8876 tree itype = TREE_TYPE (type);
8877 tree rpart, ipart, tem;
8879 if (TREE_CODE (expr) == COMPLEX_EXPR)
8881 rpart = TREE_OPERAND (expr, 0);
8882 ipart = TREE_OPERAND (expr, 1);
8884 else if (TREE_CODE (expr) == COMPLEX_CST)
8886 rpart = TREE_REALPART (expr);
8887 ipart = TREE_IMAGPART (expr);
8889 else
8891 expr = save_expr (expr);
8892 rpart = fold_build1_loc (loc, REALPART_EXPR, itype, expr);
8893 ipart = fold_build1_loc (loc, IMAGPART_EXPR, itype, expr);
8896 rpart = save_expr (rpart);
8897 ipart = save_expr (ipart);
8898 tem = fold_build2_loc (loc, PLUS_EXPR, itype,
8899 fold_build2_loc (loc, MULT_EXPR, itype, rpart, rpart),
8900 fold_build2_loc (loc, MULT_EXPR, itype, ipart, ipart));
8901 return fold_build2_loc (loc, COMPLEX_EXPR, type, tem,
8902 build_zero_cst (itype));
8906 /* Helper function for fold_vec_perm. Store elements of VECTOR_CST or
8907 CONSTRUCTOR ARG into array ELTS, which has NELTS elements, and return
8908 true if successful. */
8910 static bool
8911 vec_cst_ctor_to_array (tree arg, unsigned int nelts, tree *elts)
8913 unsigned HOST_WIDE_INT i, nunits;
8915 if (TREE_CODE (arg) == VECTOR_CST
8916 && VECTOR_CST_NELTS (arg).is_constant (&nunits))
8918 for (i = 0; i < nunits; ++i)
8919 elts[i] = VECTOR_CST_ELT (arg, i);
8921 else if (TREE_CODE (arg) == CONSTRUCTOR)
8923 constructor_elt *elt;
8925 FOR_EACH_VEC_SAFE_ELT (CONSTRUCTOR_ELTS (arg), i, elt)
8926 if (i >= nelts || TREE_CODE (TREE_TYPE (elt->value)) == VECTOR_TYPE)
8927 return false;
8928 else
8929 elts[i] = elt->value;
8931 else
8932 return false;
8933 for (; i < nelts; i++)
8934 elts[i]
8935 = fold_convert (TREE_TYPE (TREE_TYPE (arg)), integer_zero_node);
8936 return true;
8939 /* Attempt to fold vector permutation of ARG0 and ARG1 vectors using SEL
8940 selector. Return the folded VECTOR_CST or CONSTRUCTOR if successful,
8941 NULL_TREE otherwise. */
8943 static tree
8944 fold_vec_perm (tree type, tree arg0, tree arg1, const vec_perm_indices &sel)
8946 unsigned int i;
8947 unsigned HOST_WIDE_INT nelts;
8948 bool need_ctor = false;
8950 if (!sel.length ().is_constant (&nelts))
8951 return NULL_TREE;
8952 gcc_assert (known_eq (TYPE_VECTOR_SUBPARTS (type), nelts)
8953 && known_eq (TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0)), nelts)
8954 && known_eq (TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg1)), nelts));
8955 if (TREE_TYPE (TREE_TYPE (arg0)) != TREE_TYPE (type)
8956 || TREE_TYPE (TREE_TYPE (arg1)) != TREE_TYPE (type))
8957 return NULL_TREE;
8959 tree *in_elts = XALLOCAVEC (tree, nelts * 2);
8960 if (!vec_cst_ctor_to_array (arg0, nelts, in_elts)
8961 || !vec_cst_ctor_to_array (arg1, nelts, in_elts + nelts))
8962 return NULL_TREE;
8964 tree_vector_builder out_elts (type, nelts, 1);
8965 for (i = 0; i < nelts; i++)
8967 HOST_WIDE_INT index;
8968 if (!sel[i].is_constant (&index))
8969 return NULL_TREE;
8970 if (!CONSTANT_CLASS_P (in_elts[index]))
8971 need_ctor = true;
8972 out_elts.quick_push (unshare_expr (in_elts[index]));
8975 if (need_ctor)
8977 vec<constructor_elt, va_gc> *v;
8978 vec_alloc (v, nelts);
8979 for (i = 0; i < nelts; i++)
8980 CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, out_elts[i]);
8981 return build_constructor (type, v);
8983 else
8984 return out_elts.build ();
8987 /* Try to fold a pointer difference of type TYPE two address expressions of
8988 array references AREF0 and AREF1 using location LOC. Return a
8989 simplified expression for the difference or NULL_TREE. */
8991 static tree
8992 fold_addr_of_array_ref_difference (location_t loc, tree type,
8993 tree aref0, tree aref1,
8994 bool use_pointer_diff)
8996 tree base0 = TREE_OPERAND (aref0, 0);
8997 tree base1 = TREE_OPERAND (aref1, 0);
8998 tree base_offset = build_int_cst (type, 0);
9000 /* If the bases are array references as well, recurse. If the bases
9001 are pointer indirections compute the difference of the pointers.
9002 If the bases are equal, we are set. */
9003 if ((TREE_CODE (base0) == ARRAY_REF
9004 && TREE_CODE (base1) == ARRAY_REF
9005 && (base_offset
9006 = fold_addr_of_array_ref_difference (loc, type, base0, base1,
9007 use_pointer_diff)))
9008 || (INDIRECT_REF_P (base0)
9009 && INDIRECT_REF_P (base1)
9010 && (base_offset
9011 = use_pointer_diff
9012 ? fold_binary_loc (loc, POINTER_DIFF_EXPR, type,
9013 TREE_OPERAND (base0, 0),
9014 TREE_OPERAND (base1, 0))
9015 : fold_binary_loc (loc, MINUS_EXPR, type,
9016 fold_convert (type,
9017 TREE_OPERAND (base0, 0)),
9018 fold_convert (type,
9019 TREE_OPERAND (base1, 0)))))
9020 || operand_equal_p (base0, base1, OEP_ADDRESS_OF))
9022 tree op0 = fold_convert_loc (loc, type, TREE_OPERAND (aref0, 1));
9023 tree op1 = fold_convert_loc (loc, type, TREE_OPERAND (aref1, 1));
9024 tree esz = fold_convert_loc (loc, type, array_ref_element_size (aref0));
9025 tree diff = fold_build2_loc (loc, MINUS_EXPR, type, op0, op1);
9026 return fold_build2_loc (loc, PLUS_EXPR, type,
9027 base_offset,
9028 fold_build2_loc (loc, MULT_EXPR, type,
9029 diff, esz));
9031 return NULL_TREE;
9034 /* If the real or vector real constant CST of type TYPE has an exact
9035 inverse, return it, else return NULL. */
9037 tree
9038 exact_inverse (tree type, tree cst)
9040 REAL_VALUE_TYPE r;
9041 tree unit_type;
9042 machine_mode mode;
9044 switch (TREE_CODE (cst))
9046 case REAL_CST:
9047 r = TREE_REAL_CST (cst);
9049 if (exact_real_inverse (TYPE_MODE (type), &r))
9050 return build_real (type, r);
9052 return NULL_TREE;
9054 case VECTOR_CST:
9056 unit_type = TREE_TYPE (type);
9057 mode = TYPE_MODE (unit_type);
9059 tree_vector_builder elts;
9060 if (!elts.new_unary_operation (type, cst, false))
9061 return NULL_TREE;
9062 unsigned int count = elts.encoded_nelts ();
9063 for (unsigned int i = 0; i < count; ++i)
9065 r = TREE_REAL_CST (VECTOR_CST_ELT (cst, i));
9066 if (!exact_real_inverse (mode, &r))
9067 return NULL_TREE;
9068 elts.quick_push (build_real (unit_type, r));
9071 return elts.build ();
9074 default:
9075 return NULL_TREE;
9079 /* Mask out the tz least significant bits of X of type TYPE where
9080 tz is the number of trailing zeroes in Y. */
9081 static wide_int
9082 mask_with_tz (tree type, const wide_int &x, const wide_int &y)
9084 int tz = wi::ctz (y);
9085 if (tz > 0)
9086 return wi::mask (tz, true, TYPE_PRECISION (type)) & x;
9087 return x;
9090 /* Return true when T is an address and is known to be nonzero.
9091 For floating point we further ensure that T is not denormal.
9092 Similar logic is present in nonzero_address in rtlanal.h.
9094 If the return value is based on the assumption that signed overflow
9095 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
9096 change *STRICT_OVERFLOW_P. */
9098 static bool
9099 tree_expr_nonzero_warnv_p (tree t, bool *strict_overflow_p)
9101 tree type = TREE_TYPE (t);
9102 enum tree_code code;
9104 /* Doing something useful for floating point would need more work. */
9105 if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
9106 return false;
9108 code = TREE_CODE (t);
9109 switch (TREE_CODE_CLASS (code))
9111 case tcc_unary:
9112 return tree_unary_nonzero_warnv_p (code, type, TREE_OPERAND (t, 0),
9113 strict_overflow_p);
9114 case tcc_binary:
9115 case tcc_comparison:
9116 return tree_binary_nonzero_warnv_p (code, type,
9117 TREE_OPERAND (t, 0),
9118 TREE_OPERAND (t, 1),
9119 strict_overflow_p);
9120 case tcc_constant:
9121 case tcc_declaration:
9122 case tcc_reference:
9123 return tree_single_nonzero_warnv_p (t, strict_overflow_p);
9125 default:
9126 break;
9129 switch (code)
9131 case TRUTH_NOT_EXPR:
9132 return tree_unary_nonzero_warnv_p (code, type, TREE_OPERAND (t, 0),
9133 strict_overflow_p);
9135 case TRUTH_AND_EXPR:
9136 case TRUTH_OR_EXPR:
9137 case TRUTH_XOR_EXPR:
9138 return tree_binary_nonzero_warnv_p (code, type,
9139 TREE_OPERAND (t, 0),
9140 TREE_OPERAND (t, 1),
9141 strict_overflow_p);
9143 case COND_EXPR:
9144 case CONSTRUCTOR:
9145 case OBJ_TYPE_REF:
9146 case ASSERT_EXPR:
9147 case ADDR_EXPR:
9148 case WITH_SIZE_EXPR:
9149 case SSA_NAME:
9150 return tree_single_nonzero_warnv_p (t, strict_overflow_p);
9152 case COMPOUND_EXPR:
9153 case MODIFY_EXPR:
9154 case BIND_EXPR:
9155 return tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
9156 strict_overflow_p);
9158 case SAVE_EXPR:
9159 return tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
9160 strict_overflow_p);
9162 case CALL_EXPR:
9164 tree fndecl = get_callee_fndecl (t);
9165 if (!fndecl) return false;
9166 if (flag_delete_null_pointer_checks && !flag_check_new
9167 && DECL_IS_OPERATOR_NEW (fndecl)
9168 && !TREE_NOTHROW (fndecl))
9169 return true;
9170 if (flag_delete_null_pointer_checks
9171 && lookup_attribute ("returns_nonnull",
9172 TYPE_ATTRIBUTES (TREE_TYPE (fndecl))))
9173 return true;
9174 return alloca_call_p (t);
9177 default:
9178 break;
9180 return false;
9183 /* Return true when T is an address and is known to be nonzero.
9184 Handle warnings about undefined signed overflow. */
9186 bool
9187 tree_expr_nonzero_p (tree t)
9189 bool ret, strict_overflow_p;
9191 strict_overflow_p = false;
9192 ret = tree_expr_nonzero_warnv_p (t, &strict_overflow_p);
9193 if (strict_overflow_p)
9194 fold_overflow_warning (("assuming signed overflow does not occur when "
9195 "determining that expression is always "
9196 "non-zero"),
9197 WARN_STRICT_OVERFLOW_MISC);
9198 return ret;
9201 /* Return true if T is known not to be equal to an integer W. */
9203 bool
9204 expr_not_equal_to (tree t, const wide_int &w)
9206 wide_int min, max, nz;
9207 value_range_type rtype;
9208 switch (TREE_CODE (t))
9210 case INTEGER_CST:
9211 return wi::to_wide (t) != w;
9213 case SSA_NAME:
9214 if (!INTEGRAL_TYPE_P (TREE_TYPE (t)))
9215 return false;
9216 rtype = get_range_info (t, &min, &max);
9217 if (rtype == VR_RANGE)
9219 if (wi::lt_p (max, w, TYPE_SIGN (TREE_TYPE (t))))
9220 return true;
9221 if (wi::lt_p (w, min, TYPE_SIGN (TREE_TYPE (t))))
9222 return true;
9224 else if (rtype == VR_ANTI_RANGE
9225 && wi::le_p (min, w, TYPE_SIGN (TREE_TYPE (t)))
9226 && wi::le_p (w, max, TYPE_SIGN (TREE_TYPE (t))))
9227 return true;
9228 /* If T has some known zero bits and W has any of those bits set,
9229 then T is known not to be equal to W. */
9230 if (wi::ne_p (wi::zext (wi::bit_and_not (w, get_nonzero_bits (t)),
9231 TYPE_PRECISION (TREE_TYPE (t))), 0))
9232 return true;
9233 return false;
9235 default:
9236 return false;
9240 /* Fold a binary expression of code CODE and type TYPE with operands
9241 OP0 and OP1. LOC is the location of the resulting expression.
9242 Return the folded expression if folding is successful. Otherwise,
9243 return NULL_TREE. */
9245 tree
9246 fold_binary_loc (location_t loc, enum tree_code code, tree type,
9247 tree op0, tree op1)
9249 enum tree_code_class kind = TREE_CODE_CLASS (code);
9250 tree arg0, arg1, tem;
9251 tree t1 = NULL_TREE;
9252 bool strict_overflow_p;
9253 unsigned int prec;
9255 gcc_assert (IS_EXPR_CODE_CLASS (kind)
9256 && TREE_CODE_LENGTH (code) == 2
9257 && op0 != NULL_TREE
9258 && op1 != NULL_TREE);
9260 arg0 = op0;
9261 arg1 = op1;
9263 /* Strip any conversions that don't change the mode. This is
9264 safe for every expression, except for a comparison expression
9265 because its signedness is derived from its operands. So, in
9266 the latter case, only strip conversions that don't change the
9267 signedness. MIN_EXPR/MAX_EXPR also need signedness of arguments
9268 preserved.
9270 Note that this is done as an internal manipulation within the
9271 constant folder, in order to find the simplest representation
9272 of the arguments so that their form can be studied. In any
9273 cases, the appropriate type conversions should be put back in
9274 the tree that will get out of the constant folder. */
9276 if (kind == tcc_comparison || code == MIN_EXPR || code == MAX_EXPR)
9278 STRIP_SIGN_NOPS (arg0);
9279 STRIP_SIGN_NOPS (arg1);
9281 else
9283 STRIP_NOPS (arg0);
9284 STRIP_NOPS (arg1);
9287 /* Note that TREE_CONSTANT isn't enough: static var addresses are
9288 constant but we can't do arithmetic on them. */
9289 if (CONSTANT_CLASS_P (arg0) && CONSTANT_CLASS_P (arg1))
9291 tem = const_binop (code, type, arg0, arg1);
9292 if (tem != NULL_TREE)
9294 if (TREE_TYPE (tem) != type)
9295 tem = fold_convert_loc (loc, type, tem);
9296 return tem;
9300 /* If this is a commutative operation, and ARG0 is a constant, move it
9301 to ARG1 to reduce the number of tests below. */
9302 if (commutative_tree_code (code)
9303 && tree_swap_operands_p (arg0, arg1))
9304 return fold_build2_loc (loc, code, type, op1, op0);
9306 /* Likewise if this is a comparison, and ARG0 is a constant, move it
9307 to ARG1 to reduce the number of tests below. */
9308 if (kind == tcc_comparison
9309 && tree_swap_operands_p (arg0, arg1))
9310 return fold_build2_loc (loc, swap_tree_comparison (code), type, op1, op0);
9312 tem = generic_simplify (loc, code, type, op0, op1);
9313 if (tem)
9314 return tem;
9316 /* ARG0 is the first operand of EXPR, and ARG1 is the second operand.
9318 First check for cases where an arithmetic operation is applied to a
9319 compound, conditional, or comparison operation. Push the arithmetic
9320 operation inside the compound or conditional to see if any folding
9321 can then be done. Convert comparison to conditional for this purpose.
9322 The also optimizes non-constant cases that used to be done in
9323 expand_expr.
9325 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
9326 one of the operands is a comparison and the other is a comparison, a
9327 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
9328 code below would make the expression more complex. Change it to a
9329 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
9330 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
9332 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
9333 || code == EQ_EXPR || code == NE_EXPR)
9334 && !VECTOR_TYPE_P (TREE_TYPE (arg0))
9335 && ((truth_value_p (TREE_CODE (arg0))
9336 && (truth_value_p (TREE_CODE (arg1))
9337 || (TREE_CODE (arg1) == BIT_AND_EXPR
9338 && integer_onep (TREE_OPERAND (arg1, 1)))))
9339 || (truth_value_p (TREE_CODE (arg1))
9340 && (truth_value_p (TREE_CODE (arg0))
9341 || (TREE_CODE (arg0) == BIT_AND_EXPR
9342 && integer_onep (TREE_OPERAND (arg0, 1)))))))
9344 tem = fold_build2_loc (loc, code == BIT_AND_EXPR ? TRUTH_AND_EXPR
9345 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
9346 : TRUTH_XOR_EXPR,
9347 boolean_type_node,
9348 fold_convert_loc (loc, boolean_type_node, arg0),
9349 fold_convert_loc (loc, boolean_type_node, arg1));
9351 if (code == EQ_EXPR)
9352 tem = invert_truthvalue_loc (loc, tem);
9354 return fold_convert_loc (loc, type, tem);
9357 if (TREE_CODE_CLASS (code) == tcc_binary
9358 || TREE_CODE_CLASS (code) == tcc_comparison)
9360 if (TREE_CODE (arg0) == COMPOUND_EXPR)
9362 tem = fold_build2_loc (loc, code, type,
9363 fold_convert_loc (loc, TREE_TYPE (op0),
9364 TREE_OPERAND (arg0, 1)), op1);
9365 return build2_loc (loc, COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
9366 tem);
9368 if (TREE_CODE (arg1) == COMPOUND_EXPR)
9370 tem = fold_build2_loc (loc, code, type, op0,
9371 fold_convert_loc (loc, TREE_TYPE (op1),
9372 TREE_OPERAND (arg1, 1)));
9373 return build2_loc (loc, COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
9374 tem);
9377 if (TREE_CODE (arg0) == COND_EXPR
9378 || TREE_CODE (arg0) == VEC_COND_EXPR
9379 || COMPARISON_CLASS_P (arg0))
9381 tem = fold_binary_op_with_conditional_arg (loc, code, type, op0, op1,
9382 arg0, arg1,
9383 /*cond_first_p=*/1);
9384 if (tem != NULL_TREE)
9385 return tem;
9388 if (TREE_CODE (arg1) == COND_EXPR
9389 || TREE_CODE (arg1) == VEC_COND_EXPR
9390 || COMPARISON_CLASS_P (arg1))
9392 tem = fold_binary_op_with_conditional_arg (loc, code, type, op0, op1,
9393 arg1, arg0,
9394 /*cond_first_p=*/0);
9395 if (tem != NULL_TREE)
9396 return tem;
9400 switch (code)
9402 case MEM_REF:
9403 /* MEM[&MEM[p, CST1], CST2] -> MEM[p, CST1 + CST2]. */
9404 if (TREE_CODE (arg0) == ADDR_EXPR
9405 && TREE_CODE (TREE_OPERAND (arg0, 0)) == MEM_REF)
9407 tree iref = TREE_OPERAND (arg0, 0);
9408 return fold_build2 (MEM_REF, type,
9409 TREE_OPERAND (iref, 0),
9410 int_const_binop (PLUS_EXPR, arg1,
9411 TREE_OPERAND (iref, 1)));
9414 /* MEM[&a.b, CST2] -> MEM[&a, offsetof (a, b) + CST2]. */
9415 if (TREE_CODE (arg0) == ADDR_EXPR
9416 && handled_component_p (TREE_OPERAND (arg0, 0)))
9418 tree base;
9419 poly_int64 coffset;
9420 base = get_addr_base_and_unit_offset (TREE_OPERAND (arg0, 0),
9421 &coffset);
9422 if (!base)
9423 return NULL_TREE;
9424 return fold_build2 (MEM_REF, type,
9425 build_fold_addr_expr (base),
9426 int_const_binop (PLUS_EXPR, arg1,
9427 size_int (coffset)));
9430 return NULL_TREE;
9432 case POINTER_PLUS_EXPR:
9433 /* INT +p INT -> (PTR)(INT + INT). Stripping types allows for this. */
9434 if (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
9435 && INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
9436 return fold_convert_loc (loc, type,
9437 fold_build2_loc (loc, PLUS_EXPR, sizetype,
9438 fold_convert_loc (loc, sizetype,
9439 arg1),
9440 fold_convert_loc (loc, sizetype,
9441 arg0)));
9443 return NULL_TREE;
9445 case PLUS_EXPR:
9446 if (INTEGRAL_TYPE_P (type) || VECTOR_INTEGER_TYPE_P (type))
9448 /* X + (X / CST) * -CST is X % CST. */
9449 if (TREE_CODE (arg1) == MULT_EXPR
9450 && TREE_CODE (TREE_OPERAND (arg1, 0)) == TRUNC_DIV_EXPR
9451 && operand_equal_p (arg0,
9452 TREE_OPERAND (TREE_OPERAND (arg1, 0), 0), 0))
9454 tree cst0 = TREE_OPERAND (TREE_OPERAND (arg1, 0), 1);
9455 tree cst1 = TREE_OPERAND (arg1, 1);
9456 tree sum = fold_binary_loc (loc, PLUS_EXPR, TREE_TYPE (cst1),
9457 cst1, cst0);
9458 if (sum && integer_zerop (sum))
9459 return fold_convert_loc (loc, type,
9460 fold_build2_loc (loc, TRUNC_MOD_EXPR,
9461 TREE_TYPE (arg0), arg0,
9462 cst0));
9466 /* Handle (A1 * C1) + (A2 * C2) with A1, A2 or C1, C2 being the same or
9467 one. Make sure the type is not saturating and has the signedness of
9468 the stripped operands, as fold_plusminus_mult_expr will re-associate.
9469 ??? The latter condition should use TYPE_OVERFLOW_* flags instead. */
9470 if ((TREE_CODE (arg0) == MULT_EXPR
9471 || TREE_CODE (arg1) == MULT_EXPR)
9472 && !TYPE_SATURATING (type)
9473 && TYPE_UNSIGNED (type) == TYPE_UNSIGNED (TREE_TYPE (arg0))
9474 && TYPE_UNSIGNED (type) == TYPE_UNSIGNED (TREE_TYPE (arg1))
9475 && (!FLOAT_TYPE_P (type) || flag_associative_math))
9477 tree tem = fold_plusminus_mult_expr (loc, code, type, arg0, arg1);
9478 if (tem)
9479 return tem;
9482 if (! FLOAT_TYPE_P (type))
9484 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
9485 (plus (plus (mult) (mult)) (foo)) so that we can
9486 take advantage of the factoring cases below. */
9487 if (ANY_INTEGRAL_TYPE_P (type)
9488 && TYPE_OVERFLOW_WRAPS (type)
9489 && (((TREE_CODE (arg0) == PLUS_EXPR
9490 || TREE_CODE (arg0) == MINUS_EXPR)
9491 && TREE_CODE (arg1) == MULT_EXPR)
9492 || ((TREE_CODE (arg1) == PLUS_EXPR
9493 || TREE_CODE (arg1) == MINUS_EXPR)
9494 && TREE_CODE (arg0) == MULT_EXPR)))
9496 tree parg0, parg1, parg, marg;
9497 enum tree_code pcode;
9499 if (TREE_CODE (arg1) == MULT_EXPR)
9500 parg = arg0, marg = arg1;
9501 else
9502 parg = arg1, marg = arg0;
9503 pcode = TREE_CODE (parg);
9504 parg0 = TREE_OPERAND (parg, 0);
9505 parg1 = TREE_OPERAND (parg, 1);
9506 STRIP_NOPS (parg0);
9507 STRIP_NOPS (parg1);
9509 if (TREE_CODE (parg0) == MULT_EXPR
9510 && TREE_CODE (parg1) != MULT_EXPR)
9511 return fold_build2_loc (loc, pcode, type,
9512 fold_build2_loc (loc, PLUS_EXPR, type,
9513 fold_convert_loc (loc, type,
9514 parg0),
9515 fold_convert_loc (loc, type,
9516 marg)),
9517 fold_convert_loc (loc, type, parg1));
9518 if (TREE_CODE (parg0) != MULT_EXPR
9519 && TREE_CODE (parg1) == MULT_EXPR)
9520 return
9521 fold_build2_loc (loc, PLUS_EXPR, type,
9522 fold_convert_loc (loc, type, parg0),
9523 fold_build2_loc (loc, pcode, type,
9524 fold_convert_loc (loc, type, marg),
9525 fold_convert_loc (loc, type,
9526 parg1)));
9529 else
9531 /* Fold __complex__ ( x, 0 ) + __complex__ ( 0, y )
9532 to __complex__ ( x, y ). This is not the same for SNaNs or
9533 if signed zeros are involved. */
9534 if (!HONOR_SNANS (element_mode (arg0))
9535 && !HONOR_SIGNED_ZEROS (element_mode (arg0))
9536 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0)))
9538 tree rtype = TREE_TYPE (TREE_TYPE (arg0));
9539 tree arg0r = fold_unary_loc (loc, REALPART_EXPR, rtype, arg0);
9540 tree arg0i = fold_unary_loc (loc, IMAGPART_EXPR, rtype, arg0);
9541 bool arg0rz = false, arg0iz = false;
9542 if ((arg0r && (arg0rz = real_zerop (arg0r)))
9543 || (arg0i && (arg0iz = real_zerop (arg0i))))
9545 tree arg1r = fold_unary_loc (loc, REALPART_EXPR, rtype, arg1);
9546 tree arg1i = fold_unary_loc (loc, IMAGPART_EXPR, rtype, arg1);
9547 if (arg0rz && arg1i && real_zerop (arg1i))
9549 tree rp = arg1r ? arg1r
9550 : build1 (REALPART_EXPR, rtype, arg1);
9551 tree ip = arg0i ? arg0i
9552 : build1 (IMAGPART_EXPR, rtype, arg0);
9553 return fold_build2_loc (loc, COMPLEX_EXPR, type, rp, ip);
9555 else if (arg0iz && arg1r && real_zerop (arg1r))
9557 tree rp = arg0r ? arg0r
9558 : build1 (REALPART_EXPR, rtype, arg0);
9559 tree ip = arg1i ? arg1i
9560 : build1 (IMAGPART_EXPR, rtype, arg1);
9561 return fold_build2_loc (loc, COMPLEX_EXPR, type, rp, ip);
9566 /* Convert a + (b*c + d*e) into (a + b*c) + d*e.
9567 We associate floats only if the user has specified
9568 -fassociative-math. */
9569 if (flag_associative_math
9570 && TREE_CODE (arg1) == PLUS_EXPR
9571 && TREE_CODE (arg0) != MULT_EXPR)
9573 tree tree10 = TREE_OPERAND (arg1, 0);
9574 tree tree11 = TREE_OPERAND (arg1, 1);
9575 if (TREE_CODE (tree11) == MULT_EXPR
9576 && TREE_CODE (tree10) == MULT_EXPR)
9578 tree tree0;
9579 tree0 = fold_build2_loc (loc, PLUS_EXPR, type, arg0, tree10);
9580 return fold_build2_loc (loc, PLUS_EXPR, type, tree0, tree11);
9583 /* Convert (b*c + d*e) + a into b*c + (d*e +a).
9584 We associate floats only if the user has specified
9585 -fassociative-math. */
9586 if (flag_associative_math
9587 && TREE_CODE (arg0) == PLUS_EXPR
9588 && TREE_CODE (arg1) != MULT_EXPR)
9590 tree tree00 = TREE_OPERAND (arg0, 0);
9591 tree tree01 = TREE_OPERAND (arg0, 1);
9592 if (TREE_CODE (tree01) == MULT_EXPR
9593 && TREE_CODE (tree00) == MULT_EXPR)
9595 tree tree0;
9596 tree0 = fold_build2_loc (loc, PLUS_EXPR, type, tree01, arg1);
9597 return fold_build2_loc (loc, PLUS_EXPR, type, tree00, tree0);
9602 bit_rotate:
9603 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
9604 is a rotate of A by C1 bits. */
9605 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
9606 is a rotate of A by B bits.
9607 Similarly for (A << B) | (A >> (-B & C3)) where C3 is Z-1,
9608 though in this case CODE must be | and not + or ^, otherwise
9609 it doesn't return A when B is 0. */
9611 enum tree_code code0, code1;
9612 tree rtype;
9613 code0 = TREE_CODE (arg0);
9614 code1 = TREE_CODE (arg1);
9615 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
9616 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
9617 && operand_equal_p (TREE_OPERAND (arg0, 0),
9618 TREE_OPERAND (arg1, 0), 0)
9619 && (rtype = TREE_TYPE (TREE_OPERAND (arg0, 0)),
9620 TYPE_UNSIGNED (rtype))
9621 /* Only create rotates in complete modes. Other cases are not
9622 expanded properly. */
9623 && (element_precision (rtype)
9624 == GET_MODE_UNIT_PRECISION (TYPE_MODE (rtype))))
9626 tree tree01, tree11;
9627 tree orig_tree01, orig_tree11;
9628 enum tree_code code01, code11;
9630 tree01 = orig_tree01 = TREE_OPERAND (arg0, 1);
9631 tree11 = orig_tree11 = TREE_OPERAND (arg1, 1);
9632 STRIP_NOPS (tree01);
9633 STRIP_NOPS (tree11);
9634 code01 = TREE_CODE (tree01);
9635 code11 = TREE_CODE (tree11);
9636 if (code11 != MINUS_EXPR
9637 && (code01 == MINUS_EXPR || code01 == BIT_AND_EXPR))
9639 std::swap (code0, code1);
9640 std::swap (code01, code11);
9641 std::swap (tree01, tree11);
9642 std::swap (orig_tree01, orig_tree11);
9644 if (code01 == INTEGER_CST
9645 && code11 == INTEGER_CST
9646 && (wi::to_widest (tree01) + wi::to_widest (tree11)
9647 == element_precision (rtype)))
9649 tem = build2_loc (loc, LROTATE_EXPR,
9650 rtype, TREE_OPERAND (arg0, 0),
9651 code0 == LSHIFT_EXPR
9652 ? orig_tree01 : orig_tree11);
9653 return fold_convert_loc (loc, type, tem);
9655 else if (code11 == MINUS_EXPR)
9657 tree tree110, tree111;
9658 tree110 = TREE_OPERAND (tree11, 0);
9659 tree111 = TREE_OPERAND (tree11, 1);
9660 STRIP_NOPS (tree110);
9661 STRIP_NOPS (tree111);
9662 if (TREE_CODE (tree110) == INTEGER_CST
9663 && compare_tree_int (tree110,
9664 element_precision (rtype)) == 0
9665 && operand_equal_p (tree01, tree111, 0))
9667 tem = build2_loc (loc, (code0 == LSHIFT_EXPR
9668 ? LROTATE_EXPR : RROTATE_EXPR),
9669 rtype, TREE_OPERAND (arg0, 0),
9670 orig_tree01);
9671 return fold_convert_loc (loc, type, tem);
9674 else if (code == BIT_IOR_EXPR
9675 && code11 == BIT_AND_EXPR
9676 && pow2p_hwi (element_precision (rtype)))
9678 tree tree110, tree111;
9679 tree110 = TREE_OPERAND (tree11, 0);
9680 tree111 = TREE_OPERAND (tree11, 1);
9681 STRIP_NOPS (tree110);
9682 STRIP_NOPS (tree111);
9683 if (TREE_CODE (tree110) == NEGATE_EXPR
9684 && TREE_CODE (tree111) == INTEGER_CST
9685 && compare_tree_int (tree111,
9686 element_precision (rtype) - 1) == 0
9687 && operand_equal_p (tree01, TREE_OPERAND (tree110, 0), 0))
9689 tem = build2_loc (loc, (code0 == LSHIFT_EXPR
9690 ? LROTATE_EXPR : RROTATE_EXPR),
9691 rtype, TREE_OPERAND (arg0, 0),
9692 orig_tree01);
9693 return fold_convert_loc (loc, type, tem);
9699 associate:
9700 /* In most languages, can't associate operations on floats through
9701 parentheses. Rather than remember where the parentheses were, we
9702 don't associate floats at all, unless the user has specified
9703 -fassociative-math.
9704 And, we need to make sure type is not saturating. */
9706 if ((! FLOAT_TYPE_P (type) || flag_associative_math)
9707 && !TYPE_SATURATING (type))
9709 tree var0, minus_var0, con0, minus_con0, lit0, minus_lit0;
9710 tree var1, minus_var1, con1, minus_con1, lit1, minus_lit1;
9711 tree atype = type;
9712 bool ok = true;
9714 /* Split both trees into variables, constants, and literals. Then
9715 associate each group together, the constants with literals,
9716 then the result with variables. This increases the chances of
9717 literals being recombined later and of generating relocatable
9718 expressions for the sum of a constant and literal. */
9719 var0 = split_tree (arg0, type, code,
9720 &minus_var0, &con0, &minus_con0,
9721 &lit0, &minus_lit0, 0);
9722 var1 = split_tree (arg1, type, code,
9723 &minus_var1, &con1, &minus_con1,
9724 &lit1, &minus_lit1, code == MINUS_EXPR);
9726 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
9727 if (code == MINUS_EXPR)
9728 code = PLUS_EXPR;
9730 /* With undefined overflow prefer doing association in a type
9731 which wraps on overflow, if that is one of the operand types. */
9732 if ((POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
9733 && !TYPE_OVERFLOW_WRAPS (type))
9735 if (INTEGRAL_TYPE_P (TREE_TYPE (arg0))
9736 && TYPE_OVERFLOW_WRAPS (TREE_TYPE (arg0)))
9737 atype = TREE_TYPE (arg0);
9738 else if (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
9739 && TYPE_OVERFLOW_WRAPS (TREE_TYPE (arg1)))
9740 atype = TREE_TYPE (arg1);
9741 gcc_assert (TYPE_PRECISION (atype) == TYPE_PRECISION (type));
9744 /* With undefined overflow we can only associate constants with one
9745 variable, and constants whose association doesn't overflow. */
9746 if ((POINTER_TYPE_P (atype) || INTEGRAL_TYPE_P (atype))
9747 && !TYPE_OVERFLOW_WRAPS (atype))
9749 if ((var0 && var1) || (minus_var0 && minus_var1))
9751 /* ??? If split_tree would handle NEGATE_EXPR we could
9752 simply reject these cases and the allowed cases would
9753 be the var0/minus_var1 ones. */
9754 tree tmp0 = var0 ? var0 : minus_var0;
9755 tree tmp1 = var1 ? var1 : minus_var1;
9756 bool one_neg = false;
9758 if (TREE_CODE (tmp0) == NEGATE_EXPR)
9760 tmp0 = TREE_OPERAND (tmp0, 0);
9761 one_neg = !one_neg;
9763 if (CONVERT_EXPR_P (tmp0)
9764 && INTEGRAL_TYPE_P (TREE_TYPE (TREE_OPERAND (tmp0, 0)))
9765 && (TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (tmp0, 0)))
9766 <= TYPE_PRECISION (atype)))
9767 tmp0 = TREE_OPERAND (tmp0, 0);
9768 if (TREE_CODE (tmp1) == NEGATE_EXPR)
9770 tmp1 = TREE_OPERAND (tmp1, 0);
9771 one_neg = !one_neg;
9773 if (CONVERT_EXPR_P (tmp1)
9774 && INTEGRAL_TYPE_P (TREE_TYPE (TREE_OPERAND (tmp1, 0)))
9775 && (TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (tmp1, 0)))
9776 <= TYPE_PRECISION (atype)))
9777 tmp1 = TREE_OPERAND (tmp1, 0);
9778 /* The only case we can still associate with two variables
9779 is if they cancel out. */
9780 if (!one_neg
9781 || !operand_equal_p (tmp0, tmp1, 0))
9782 ok = false;
9784 else if ((var0 && minus_var1
9785 && ! operand_equal_p (var0, minus_var1, 0))
9786 || (minus_var0 && var1
9787 && ! operand_equal_p (minus_var0, var1, 0)))
9788 ok = false;
9791 /* Only do something if we found more than two objects. Otherwise,
9792 nothing has changed and we risk infinite recursion. */
9793 if (ok
9794 && ((var0 != 0) + (var1 != 0)
9795 + (minus_var0 != 0) + (minus_var1 != 0)
9796 + (con0 != 0) + (con1 != 0)
9797 + (minus_con0 != 0) + (minus_con1 != 0)
9798 + (lit0 != 0) + (lit1 != 0)
9799 + (minus_lit0 != 0) + (minus_lit1 != 0)) > 2)
9801 var0 = associate_trees (loc, var0, var1, code, atype);
9802 minus_var0 = associate_trees (loc, minus_var0, minus_var1,
9803 code, atype);
9804 con0 = associate_trees (loc, con0, con1, code, atype);
9805 minus_con0 = associate_trees (loc, minus_con0, minus_con1,
9806 code, atype);
9807 lit0 = associate_trees (loc, lit0, lit1, code, atype);
9808 minus_lit0 = associate_trees (loc, minus_lit0, minus_lit1,
9809 code, atype);
9811 if (minus_var0 && var0)
9813 var0 = associate_trees (loc, var0, minus_var0,
9814 MINUS_EXPR, atype);
9815 minus_var0 = 0;
9817 if (minus_con0 && con0)
9819 con0 = associate_trees (loc, con0, minus_con0,
9820 MINUS_EXPR, atype);
9821 minus_con0 = 0;
9824 /* Preserve the MINUS_EXPR if the negative part of the literal is
9825 greater than the positive part. Otherwise, the multiplicative
9826 folding code (i.e extract_muldiv) may be fooled in case
9827 unsigned constants are subtracted, like in the following
9828 example: ((X*2 + 4) - 8U)/2. */
9829 if (minus_lit0 && lit0)
9831 if (TREE_CODE (lit0) == INTEGER_CST
9832 && TREE_CODE (minus_lit0) == INTEGER_CST
9833 && tree_int_cst_lt (lit0, minus_lit0)
9834 /* But avoid ending up with only negated parts. */
9835 && (var0 || con0))
9837 minus_lit0 = associate_trees (loc, minus_lit0, lit0,
9838 MINUS_EXPR, atype);
9839 lit0 = 0;
9841 else
9843 lit0 = associate_trees (loc, lit0, minus_lit0,
9844 MINUS_EXPR, atype);
9845 minus_lit0 = 0;
9849 /* Don't introduce overflows through reassociation. */
9850 if ((lit0 && TREE_OVERFLOW_P (lit0))
9851 || (minus_lit0 && TREE_OVERFLOW_P (minus_lit0)))
9852 return NULL_TREE;
9854 /* Eliminate lit0 and minus_lit0 to con0 and minus_con0. */
9855 con0 = associate_trees (loc, con0, lit0, code, atype);
9856 lit0 = 0;
9857 minus_con0 = associate_trees (loc, minus_con0, minus_lit0,
9858 code, atype);
9859 minus_lit0 = 0;
9861 /* Eliminate minus_con0. */
9862 if (minus_con0)
9864 if (con0)
9865 con0 = associate_trees (loc, con0, minus_con0,
9866 MINUS_EXPR, atype);
9867 else if (var0)
9868 var0 = associate_trees (loc, var0, minus_con0,
9869 MINUS_EXPR, atype);
9870 else
9871 gcc_unreachable ();
9872 minus_con0 = 0;
9875 /* Eliminate minus_var0. */
9876 if (minus_var0)
9878 if (con0)
9879 con0 = associate_trees (loc, con0, minus_var0,
9880 MINUS_EXPR, atype);
9881 else
9882 gcc_unreachable ();
9883 minus_var0 = 0;
9886 return
9887 fold_convert_loc (loc, type, associate_trees (loc, var0, con0,
9888 code, atype));
9892 return NULL_TREE;
9894 case POINTER_DIFF_EXPR:
9895 case MINUS_EXPR:
9896 /* Fold &a[i] - &a[j] to i-j. */
9897 if (TREE_CODE (arg0) == ADDR_EXPR
9898 && TREE_CODE (TREE_OPERAND (arg0, 0)) == ARRAY_REF
9899 && TREE_CODE (arg1) == ADDR_EXPR
9900 && TREE_CODE (TREE_OPERAND (arg1, 0)) == ARRAY_REF)
9902 tree tem = fold_addr_of_array_ref_difference (loc, type,
9903 TREE_OPERAND (arg0, 0),
9904 TREE_OPERAND (arg1, 0),
9905 code
9906 == POINTER_DIFF_EXPR);
9907 if (tem)
9908 return tem;
9911 /* Further transformations are not for pointers. */
9912 if (code == POINTER_DIFF_EXPR)
9913 return NULL_TREE;
9915 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
9916 if (TREE_CODE (arg0) == NEGATE_EXPR
9917 && negate_expr_p (op1)
9918 /* If arg0 is e.g. unsigned int and type is int, then this could
9919 introduce UB, because if A is INT_MIN at runtime, the original
9920 expression can be well defined while the latter is not.
9921 See PR83269. */
9922 && !(ANY_INTEGRAL_TYPE_P (type)
9923 && TYPE_OVERFLOW_UNDEFINED (type)
9924 && ANY_INTEGRAL_TYPE_P (TREE_TYPE (arg0))
9925 && !TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))))
9926 return fold_build2_loc (loc, MINUS_EXPR, type, negate_expr (op1),
9927 fold_convert_loc (loc, type,
9928 TREE_OPERAND (arg0, 0)));
9930 /* Fold __complex__ ( x, 0 ) - __complex__ ( 0, y ) to
9931 __complex__ ( x, -y ). This is not the same for SNaNs or if
9932 signed zeros are involved. */
9933 if (!HONOR_SNANS (element_mode (arg0))
9934 && !HONOR_SIGNED_ZEROS (element_mode (arg0))
9935 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0)))
9937 tree rtype = TREE_TYPE (TREE_TYPE (arg0));
9938 tree arg0r = fold_unary_loc (loc, REALPART_EXPR, rtype, arg0);
9939 tree arg0i = fold_unary_loc (loc, IMAGPART_EXPR, rtype, arg0);
9940 bool arg0rz = false, arg0iz = false;
9941 if ((arg0r && (arg0rz = real_zerop (arg0r)))
9942 || (arg0i && (arg0iz = real_zerop (arg0i))))
9944 tree arg1r = fold_unary_loc (loc, REALPART_EXPR, rtype, arg1);
9945 tree arg1i = fold_unary_loc (loc, IMAGPART_EXPR, rtype, arg1);
9946 if (arg0rz && arg1i && real_zerop (arg1i))
9948 tree rp = fold_build1_loc (loc, NEGATE_EXPR, rtype,
9949 arg1r ? arg1r
9950 : build1 (REALPART_EXPR, rtype, arg1));
9951 tree ip = arg0i ? arg0i
9952 : build1 (IMAGPART_EXPR, rtype, arg0);
9953 return fold_build2_loc (loc, COMPLEX_EXPR, type, rp, ip);
9955 else if (arg0iz && arg1r && real_zerop (arg1r))
9957 tree rp = arg0r ? arg0r
9958 : build1 (REALPART_EXPR, rtype, arg0);
9959 tree ip = fold_build1_loc (loc, NEGATE_EXPR, rtype,
9960 arg1i ? arg1i
9961 : build1 (IMAGPART_EXPR, rtype, arg1));
9962 return fold_build2_loc (loc, COMPLEX_EXPR, type, rp, ip);
9967 /* A - B -> A + (-B) if B is easily negatable. */
9968 if (negate_expr_p (op1)
9969 && ! TYPE_OVERFLOW_SANITIZED (type)
9970 && ((FLOAT_TYPE_P (type)
9971 /* Avoid this transformation if B is a positive REAL_CST. */
9972 && (TREE_CODE (op1) != REAL_CST
9973 || REAL_VALUE_NEGATIVE (TREE_REAL_CST (op1))))
9974 || INTEGRAL_TYPE_P (type)))
9975 return fold_build2_loc (loc, PLUS_EXPR, type,
9976 fold_convert_loc (loc, type, arg0),
9977 negate_expr (op1));
9979 /* Handle (A1 * C1) - (A2 * C2) with A1, A2 or C1, C2 being the same or
9980 one. Make sure the type is not saturating and has the signedness of
9981 the stripped operands, as fold_plusminus_mult_expr will re-associate.
9982 ??? The latter condition should use TYPE_OVERFLOW_* flags instead. */
9983 if ((TREE_CODE (arg0) == MULT_EXPR
9984 || TREE_CODE (arg1) == MULT_EXPR)
9985 && !TYPE_SATURATING (type)
9986 && TYPE_UNSIGNED (type) == TYPE_UNSIGNED (TREE_TYPE (arg0))
9987 && TYPE_UNSIGNED (type) == TYPE_UNSIGNED (TREE_TYPE (arg1))
9988 && (!FLOAT_TYPE_P (type) || flag_associative_math))
9990 tree tem = fold_plusminus_mult_expr (loc, code, type, arg0, arg1);
9991 if (tem)
9992 return tem;
9995 goto associate;
9997 case MULT_EXPR:
9998 if (! FLOAT_TYPE_P (type))
10000 /* Transform x * -C into -x * C if x is easily negatable. */
10001 if (TREE_CODE (op1) == INTEGER_CST
10002 && tree_int_cst_sgn (op1) == -1
10003 && negate_expr_p (op0)
10004 && negate_expr_p (op1)
10005 && (tem = negate_expr (op1)) != op1
10006 && ! TREE_OVERFLOW (tem))
10007 return fold_build2_loc (loc, MULT_EXPR, type,
10008 fold_convert_loc (loc, type,
10009 negate_expr (op0)), tem);
10011 strict_overflow_p = false;
10012 if (TREE_CODE (arg1) == INTEGER_CST
10013 && (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
10014 &strict_overflow_p)) != 0)
10016 if (strict_overflow_p)
10017 fold_overflow_warning (("assuming signed overflow does not "
10018 "occur when simplifying "
10019 "multiplication"),
10020 WARN_STRICT_OVERFLOW_MISC);
10021 return fold_convert_loc (loc, type, tem);
10024 /* Optimize z * conj(z) for integer complex numbers. */
10025 if (TREE_CODE (arg0) == CONJ_EXPR
10026 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10027 return fold_mult_zconjz (loc, type, arg1);
10028 if (TREE_CODE (arg1) == CONJ_EXPR
10029 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10030 return fold_mult_zconjz (loc, type, arg0);
10032 else
10034 /* Fold z * +-I to __complex__ (-+__imag z, +-__real z).
10035 This is not the same for NaNs or if signed zeros are
10036 involved. */
10037 if (!HONOR_NANS (arg0)
10038 && !HONOR_SIGNED_ZEROS (element_mode (arg0))
10039 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0))
10040 && TREE_CODE (arg1) == COMPLEX_CST
10041 && real_zerop (TREE_REALPART (arg1)))
10043 tree rtype = TREE_TYPE (TREE_TYPE (arg0));
10044 if (real_onep (TREE_IMAGPART (arg1)))
10045 return
10046 fold_build2_loc (loc, COMPLEX_EXPR, type,
10047 negate_expr (fold_build1_loc (loc, IMAGPART_EXPR,
10048 rtype, arg0)),
10049 fold_build1_loc (loc, REALPART_EXPR, rtype, arg0));
10050 else if (real_minus_onep (TREE_IMAGPART (arg1)))
10051 return
10052 fold_build2_loc (loc, COMPLEX_EXPR, type,
10053 fold_build1_loc (loc, IMAGPART_EXPR, rtype, arg0),
10054 negate_expr (fold_build1_loc (loc, REALPART_EXPR,
10055 rtype, arg0)));
10058 /* Optimize z * conj(z) for floating point complex numbers.
10059 Guarded by flag_unsafe_math_optimizations as non-finite
10060 imaginary components don't produce scalar results. */
10061 if (flag_unsafe_math_optimizations
10062 && TREE_CODE (arg0) == CONJ_EXPR
10063 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10064 return fold_mult_zconjz (loc, type, arg1);
10065 if (flag_unsafe_math_optimizations
10066 && TREE_CODE (arg1) == CONJ_EXPR
10067 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10068 return fold_mult_zconjz (loc, type, arg0);
10070 goto associate;
10072 case BIT_IOR_EXPR:
10073 /* Canonicalize (X & C1) | C2. */
10074 if (TREE_CODE (arg0) == BIT_AND_EXPR
10075 && TREE_CODE (arg1) == INTEGER_CST
10076 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
10078 int width = TYPE_PRECISION (type), w;
10079 wide_int c1 = wi::to_wide (TREE_OPERAND (arg0, 1));
10080 wide_int c2 = wi::to_wide (arg1);
10082 /* If (C1&C2) == C1, then (X&C1)|C2 becomes (X,C2). */
10083 if ((c1 & c2) == c1)
10084 return omit_one_operand_loc (loc, type, arg1,
10085 TREE_OPERAND (arg0, 0));
10087 wide_int msk = wi::mask (width, false,
10088 TYPE_PRECISION (TREE_TYPE (arg1)));
10090 /* If (C1|C2) == ~0 then (X&C1)|C2 becomes X|C2. */
10091 if (wi::bit_and_not (msk, c1 | c2) == 0)
10093 tem = fold_convert_loc (loc, type, TREE_OPERAND (arg0, 0));
10094 return fold_build2_loc (loc, BIT_IOR_EXPR, type, tem, arg1);
10097 /* Minimize the number of bits set in C1, i.e. C1 := C1 & ~C2,
10098 unless (C1 & ~C2) | (C2 & C3) for some C3 is a mask of some
10099 mode which allows further optimizations. */
10100 c1 &= msk;
10101 c2 &= msk;
10102 wide_int c3 = wi::bit_and_not (c1, c2);
10103 for (w = BITS_PER_UNIT; w <= width; w <<= 1)
10105 wide_int mask = wi::mask (w, false,
10106 TYPE_PRECISION (type));
10107 if (((c1 | c2) & mask) == mask
10108 && wi::bit_and_not (c1, mask) == 0)
10110 c3 = mask;
10111 break;
10115 if (c3 != c1)
10117 tem = fold_convert_loc (loc, type, TREE_OPERAND (arg0, 0));
10118 tem = fold_build2_loc (loc, BIT_AND_EXPR, type, tem,
10119 wide_int_to_tree (type, c3));
10120 return fold_build2_loc (loc, BIT_IOR_EXPR, type, tem, arg1);
10124 /* See if this can be simplified into a rotate first. If that
10125 is unsuccessful continue in the association code. */
10126 goto bit_rotate;
10128 case BIT_XOR_EXPR:
10129 /* Fold (X & 1) ^ 1 as (X & 1) == 0. */
10130 if (TREE_CODE (arg0) == BIT_AND_EXPR
10131 && INTEGRAL_TYPE_P (type)
10132 && integer_onep (TREE_OPERAND (arg0, 1))
10133 && integer_onep (arg1))
10134 return fold_build2_loc (loc, EQ_EXPR, type, arg0,
10135 build_zero_cst (TREE_TYPE (arg0)));
10137 /* See if this can be simplified into a rotate first. If that
10138 is unsuccessful continue in the association code. */
10139 goto bit_rotate;
10141 case BIT_AND_EXPR:
10142 /* Fold (X ^ 1) & 1 as (X & 1) == 0. */
10143 if (TREE_CODE (arg0) == BIT_XOR_EXPR
10144 && INTEGRAL_TYPE_P (type)
10145 && integer_onep (TREE_OPERAND (arg0, 1))
10146 && integer_onep (arg1))
10148 tree tem2;
10149 tem = TREE_OPERAND (arg0, 0);
10150 tem2 = fold_convert_loc (loc, TREE_TYPE (tem), arg1);
10151 tem2 = fold_build2_loc (loc, BIT_AND_EXPR, TREE_TYPE (tem),
10152 tem, tem2);
10153 return fold_build2_loc (loc, EQ_EXPR, type, tem2,
10154 build_zero_cst (TREE_TYPE (tem)));
10156 /* Fold ~X & 1 as (X & 1) == 0. */
10157 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10158 && INTEGRAL_TYPE_P (type)
10159 && integer_onep (arg1))
10161 tree tem2;
10162 tem = TREE_OPERAND (arg0, 0);
10163 tem2 = fold_convert_loc (loc, TREE_TYPE (tem), arg1);
10164 tem2 = fold_build2_loc (loc, BIT_AND_EXPR, TREE_TYPE (tem),
10165 tem, tem2);
10166 return fold_build2_loc (loc, EQ_EXPR, type, tem2,
10167 build_zero_cst (TREE_TYPE (tem)));
10169 /* Fold !X & 1 as X == 0. */
10170 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
10171 && integer_onep (arg1))
10173 tem = TREE_OPERAND (arg0, 0);
10174 return fold_build2_loc (loc, EQ_EXPR, type, tem,
10175 build_zero_cst (TREE_TYPE (tem)));
10178 /* Fold (X * Y) & -(1 << CST) to X * Y if Y is a constant
10179 multiple of 1 << CST. */
10180 if (TREE_CODE (arg1) == INTEGER_CST)
10182 wi::tree_to_wide_ref cst1 = wi::to_wide (arg1);
10183 wide_int ncst1 = -cst1;
10184 if ((cst1 & ncst1) == ncst1
10185 && multiple_of_p (type, arg0,
10186 wide_int_to_tree (TREE_TYPE (arg1), ncst1)))
10187 return fold_convert_loc (loc, type, arg0);
10190 /* Fold (X * CST1) & CST2 to zero if we can, or drop known zero
10191 bits from CST2. */
10192 if (TREE_CODE (arg1) == INTEGER_CST
10193 && TREE_CODE (arg0) == MULT_EXPR
10194 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
10196 wi::tree_to_wide_ref warg1 = wi::to_wide (arg1);
10197 wide_int masked
10198 = mask_with_tz (type, warg1, wi::to_wide (TREE_OPERAND (arg0, 1)));
10200 if (masked == 0)
10201 return omit_two_operands_loc (loc, type, build_zero_cst (type),
10202 arg0, arg1);
10203 else if (masked != warg1)
10205 /* Avoid the transform if arg1 is a mask of some
10206 mode which allows further optimizations. */
10207 int pop = wi::popcount (warg1);
10208 if (!(pop >= BITS_PER_UNIT
10209 && pow2p_hwi (pop)
10210 && wi::mask (pop, false, warg1.get_precision ()) == warg1))
10211 return fold_build2_loc (loc, code, type, op0,
10212 wide_int_to_tree (type, masked));
10216 /* For constants M and N, if M == (1LL << cst) - 1 && (N & M) == M,
10217 ((A & N) + B) & M -> (A + B) & M
10218 Similarly if (N & M) == 0,
10219 ((A | N) + B) & M -> (A + B) & M
10220 and for - instead of + (or unary - instead of +)
10221 and/or ^ instead of |.
10222 If B is constant and (B & M) == 0, fold into A & M. */
10223 if (TREE_CODE (arg1) == INTEGER_CST)
10225 wi::tree_to_wide_ref cst1 = wi::to_wide (arg1);
10226 if ((~cst1 != 0) && (cst1 & (cst1 + 1)) == 0
10227 && INTEGRAL_TYPE_P (TREE_TYPE (arg0))
10228 && (TREE_CODE (arg0) == PLUS_EXPR
10229 || TREE_CODE (arg0) == MINUS_EXPR
10230 || TREE_CODE (arg0) == NEGATE_EXPR)
10231 && (TYPE_OVERFLOW_WRAPS (TREE_TYPE (arg0))
10232 || TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE))
10234 tree pmop[2];
10235 int which = 0;
10236 wide_int cst0;
10238 /* Now we know that arg0 is (C + D) or (C - D) or
10239 -C and arg1 (M) is == (1LL << cst) - 1.
10240 Store C into PMOP[0] and D into PMOP[1]. */
10241 pmop[0] = TREE_OPERAND (arg0, 0);
10242 pmop[1] = NULL;
10243 if (TREE_CODE (arg0) != NEGATE_EXPR)
10245 pmop[1] = TREE_OPERAND (arg0, 1);
10246 which = 1;
10249 if ((wi::max_value (TREE_TYPE (arg0)) & cst1) != cst1)
10250 which = -1;
10252 for (; which >= 0; which--)
10253 switch (TREE_CODE (pmop[which]))
10255 case BIT_AND_EXPR:
10256 case BIT_IOR_EXPR:
10257 case BIT_XOR_EXPR:
10258 if (TREE_CODE (TREE_OPERAND (pmop[which], 1))
10259 != INTEGER_CST)
10260 break;
10261 cst0 = wi::to_wide (TREE_OPERAND (pmop[which], 1)) & cst1;
10262 if (TREE_CODE (pmop[which]) == BIT_AND_EXPR)
10264 if (cst0 != cst1)
10265 break;
10267 else if (cst0 != 0)
10268 break;
10269 /* If C or D is of the form (A & N) where
10270 (N & M) == M, or of the form (A | N) or
10271 (A ^ N) where (N & M) == 0, replace it with A. */
10272 pmop[which] = TREE_OPERAND (pmop[which], 0);
10273 break;
10274 case INTEGER_CST:
10275 /* If C or D is a N where (N & M) == 0, it can be
10276 omitted (assumed 0). */
10277 if ((TREE_CODE (arg0) == PLUS_EXPR
10278 || (TREE_CODE (arg0) == MINUS_EXPR && which == 0))
10279 && (cst1 & wi::to_wide (pmop[which])) == 0)
10280 pmop[which] = NULL;
10281 break;
10282 default:
10283 break;
10286 /* Only build anything new if we optimized one or both arguments
10287 above. */
10288 if (pmop[0] != TREE_OPERAND (arg0, 0)
10289 || (TREE_CODE (arg0) != NEGATE_EXPR
10290 && pmop[1] != TREE_OPERAND (arg0, 1)))
10292 tree utype = TREE_TYPE (arg0);
10293 if (! TYPE_OVERFLOW_WRAPS (TREE_TYPE (arg0)))
10295 /* Perform the operations in a type that has defined
10296 overflow behavior. */
10297 utype = unsigned_type_for (TREE_TYPE (arg0));
10298 if (pmop[0] != NULL)
10299 pmop[0] = fold_convert_loc (loc, utype, pmop[0]);
10300 if (pmop[1] != NULL)
10301 pmop[1] = fold_convert_loc (loc, utype, pmop[1]);
10304 if (TREE_CODE (arg0) == NEGATE_EXPR)
10305 tem = fold_build1_loc (loc, NEGATE_EXPR, utype, pmop[0]);
10306 else if (TREE_CODE (arg0) == PLUS_EXPR)
10308 if (pmop[0] != NULL && pmop[1] != NULL)
10309 tem = fold_build2_loc (loc, PLUS_EXPR, utype,
10310 pmop[0], pmop[1]);
10311 else if (pmop[0] != NULL)
10312 tem = pmop[0];
10313 else if (pmop[1] != NULL)
10314 tem = pmop[1];
10315 else
10316 return build_int_cst (type, 0);
10318 else if (pmop[0] == NULL)
10319 tem = fold_build1_loc (loc, NEGATE_EXPR, utype, pmop[1]);
10320 else
10321 tem = fold_build2_loc (loc, MINUS_EXPR, utype,
10322 pmop[0], pmop[1]);
10323 /* TEM is now the new binary +, - or unary - replacement. */
10324 tem = fold_build2_loc (loc, BIT_AND_EXPR, utype, tem,
10325 fold_convert_loc (loc, utype, arg1));
10326 return fold_convert_loc (loc, type, tem);
10331 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
10332 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
10333 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
10335 prec = element_precision (TREE_TYPE (TREE_OPERAND (arg0, 0)));
10337 wide_int mask = wide_int::from (wi::to_wide (arg1), prec, UNSIGNED);
10338 if (mask == -1)
10339 return
10340 fold_convert_loc (loc, type, TREE_OPERAND (arg0, 0));
10343 goto associate;
10345 case RDIV_EXPR:
10346 /* Don't touch a floating-point divide by zero unless the mode
10347 of the constant can represent infinity. */
10348 if (TREE_CODE (arg1) == REAL_CST
10349 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
10350 && real_zerop (arg1))
10351 return NULL_TREE;
10353 /* (-A) / (-B) -> A / B */
10354 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
10355 return fold_build2_loc (loc, RDIV_EXPR, type,
10356 TREE_OPERAND (arg0, 0),
10357 negate_expr (arg1));
10358 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
10359 return fold_build2_loc (loc, RDIV_EXPR, type,
10360 negate_expr (arg0),
10361 TREE_OPERAND (arg1, 0));
10362 return NULL_TREE;
10364 case TRUNC_DIV_EXPR:
10365 /* Fall through */
10367 case FLOOR_DIV_EXPR:
10368 /* Simplify A / (B << N) where A and B are positive and B is
10369 a power of 2, to A >> (N + log2(B)). */
10370 strict_overflow_p = false;
10371 if (TREE_CODE (arg1) == LSHIFT_EXPR
10372 && (TYPE_UNSIGNED (type)
10373 || tree_expr_nonnegative_warnv_p (op0, &strict_overflow_p)))
10375 tree sval = TREE_OPERAND (arg1, 0);
10376 if (integer_pow2p (sval) && tree_int_cst_sgn (sval) > 0)
10378 tree sh_cnt = TREE_OPERAND (arg1, 1);
10379 tree pow2 = build_int_cst (TREE_TYPE (sh_cnt),
10380 wi::exact_log2 (wi::to_wide (sval)));
10382 if (strict_overflow_p)
10383 fold_overflow_warning (("assuming signed overflow does not "
10384 "occur when simplifying A / (B << N)"),
10385 WARN_STRICT_OVERFLOW_MISC);
10387 sh_cnt = fold_build2_loc (loc, PLUS_EXPR, TREE_TYPE (sh_cnt),
10388 sh_cnt, pow2);
10389 return fold_build2_loc (loc, RSHIFT_EXPR, type,
10390 fold_convert_loc (loc, type, arg0), sh_cnt);
10394 /* Fall through */
10396 case ROUND_DIV_EXPR:
10397 case CEIL_DIV_EXPR:
10398 case EXACT_DIV_EXPR:
10399 if (integer_zerop (arg1))
10400 return NULL_TREE;
10402 /* Convert -A / -B to A / B when the type is signed and overflow is
10403 undefined. */
10404 if ((!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
10405 && TREE_CODE (op0) == NEGATE_EXPR
10406 && negate_expr_p (op1))
10408 if (INTEGRAL_TYPE_P (type))
10409 fold_overflow_warning (("assuming signed overflow does not occur "
10410 "when distributing negation across "
10411 "division"),
10412 WARN_STRICT_OVERFLOW_MISC);
10413 return fold_build2_loc (loc, code, type,
10414 fold_convert_loc (loc, type,
10415 TREE_OPERAND (arg0, 0)),
10416 negate_expr (op1));
10418 if ((!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
10419 && TREE_CODE (arg1) == NEGATE_EXPR
10420 && negate_expr_p (op0))
10422 if (INTEGRAL_TYPE_P (type))
10423 fold_overflow_warning (("assuming signed overflow does not occur "
10424 "when distributing negation across "
10425 "division"),
10426 WARN_STRICT_OVERFLOW_MISC);
10427 return fold_build2_loc (loc, code, type,
10428 negate_expr (op0),
10429 fold_convert_loc (loc, type,
10430 TREE_OPERAND (arg1, 0)));
10433 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
10434 operation, EXACT_DIV_EXPR.
10436 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
10437 At one time others generated faster code, it's not clear if they do
10438 after the last round to changes to the DIV code in expmed.c. */
10439 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
10440 && multiple_of_p (type, arg0, arg1))
10441 return fold_build2_loc (loc, EXACT_DIV_EXPR, type,
10442 fold_convert (type, arg0),
10443 fold_convert (type, arg1));
10445 strict_overflow_p = false;
10446 if (TREE_CODE (arg1) == INTEGER_CST
10447 && (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
10448 &strict_overflow_p)) != 0)
10450 if (strict_overflow_p)
10451 fold_overflow_warning (("assuming signed overflow does not occur "
10452 "when simplifying division"),
10453 WARN_STRICT_OVERFLOW_MISC);
10454 return fold_convert_loc (loc, type, tem);
10457 return NULL_TREE;
10459 case CEIL_MOD_EXPR:
10460 case FLOOR_MOD_EXPR:
10461 case ROUND_MOD_EXPR:
10462 case TRUNC_MOD_EXPR:
10463 strict_overflow_p = false;
10464 if (TREE_CODE (arg1) == INTEGER_CST
10465 && (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
10466 &strict_overflow_p)) != 0)
10468 if (strict_overflow_p)
10469 fold_overflow_warning (("assuming signed overflow does not occur "
10470 "when simplifying modulus"),
10471 WARN_STRICT_OVERFLOW_MISC);
10472 return fold_convert_loc (loc, type, tem);
10475 return NULL_TREE;
10477 case LROTATE_EXPR:
10478 case RROTATE_EXPR:
10479 case RSHIFT_EXPR:
10480 case LSHIFT_EXPR:
10481 /* Since negative shift count is not well-defined,
10482 don't try to compute it in the compiler. */
10483 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
10484 return NULL_TREE;
10486 prec = element_precision (type);
10488 /* If we have a rotate of a bit operation with the rotate count and
10489 the second operand of the bit operation both constant,
10490 permute the two operations. */
10491 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
10492 && (TREE_CODE (arg0) == BIT_AND_EXPR
10493 || TREE_CODE (arg0) == BIT_IOR_EXPR
10494 || TREE_CODE (arg0) == BIT_XOR_EXPR)
10495 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
10497 tree arg00 = fold_convert_loc (loc, type, TREE_OPERAND (arg0, 0));
10498 tree arg01 = fold_convert_loc (loc, type, TREE_OPERAND (arg0, 1));
10499 return fold_build2_loc (loc, TREE_CODE (arg0), type,
10500 fold_build2_loc (loc, code, type,
10501 arg00, arg1),
10502 fold_build2_loc (loc, code, type,
10503 arg01, arg1));
10506 /* Two consecutive rotates adding up to the some integer
10507 multiple of the precision of the type can be ignored. */
10508 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
10509 && TREE_CODE (arg0) == RROTATE_EXPR
10510 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
10511 && wi::umod_trunc (wi::to_wide (arg1)
10512 + wi::to_wide (TREE_OPERAND (arg0, 1)),
10513 prec) == 0)
10514 return fold_convert_loc (loc, type, TREE_OPERAND (arg0, 0));
10516 return NULL_TREE;
10518 case MIN_EXPR:
10519 case MAX_EXPR:
10520 goto associate;
10522 case TRUTH_ANDIF_EXPR:
10523 /* Note that the operands of this must be ints
10524 and their values must be 0 or 1.
10525 ("true" is a fixed value perhaps depending on the language.) */
10526 /* If first arg is constant zero, return it. */
10527 if (integer_zerop (arg0))
10528 return fold_convert_loc (loc, type, arg0);
10529 /* FALLTHRU */
10530 case TRUTH_AND_EXPR:
10531 /* If either arg is constant true, drop it. */
10532 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
10533 return non_lvalue_loc (loc, fold_convert_loc (loc, type, arg1));
10534 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
10535 /* Preserve sequence points. */
10536 && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
10537 return non_lvalue_loc (loc, fold_convert_loc (loc, type, arg0));
10538 /* If second arg is constant zero, result is zero, but first arg
10539 must be evaluated. */
10540 if (integer_zerop (arg1))
10541 return omit_one_operand_loc (loc, type, arg1, arg0);
10542 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
10543 case will be handled here. */
10544 if (integer_zerop (arg0))
10545 return omit_one_operand_loc (loc, type, arg0, arg1);
10547 /* !X && X is always false. */
10548 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
10549 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10550 return omit_one_operand_loc (loc, type, integer_zero_node, arg1);
10551 /* X && !X is always false. */
10552 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
10553 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10554 return omit_one_operand_loc (loc, type, integer_zero_node, arg0);
10556 /* A < X && A + 1 > Y ==> A < X && A >= Y. Normally A + 1 > Y
10557 means A >= Y && A != MAX, but in this case we know that
10558 A < X <= MAX. */
10560 if (!TREE_SIDE_EFFECTS (arg0)
10561 && !TREE_SIDE_EFFECTS (arg1))
10563 tem = fold_to_nonsharp_ineq_using_bound (loc, arg0, arg1);
10564 if (tem && !operand_equal_p (tem, arg0, 0))
10565 return fold_build2_loc (loc, code, type, tem, arg1);
10567 tem = fold_to_nonsharp_ineq_using_bound (loc, arg1, arg0);
10568 if (tem && !operand_equal_p (tem, arg1, 0))
10569 return fold_build2_loc (loc, code, type, arg0, tem);
10572 if ((tem = fold_truth_andor (loc, code, type, arg0, arg1, op0, op1))
10573 != NULL_TREE)
10574 return tem;
10576 return NULL_TREE;
10578 case TRUTH_ORIF_EXPR:
10579 /* Note that the operands of this must be ints
10580 and their values must be 0 or true.
10581 ("true" is a fixed value perhaps depending on the language.) */
10582 /* If first arg is constant true, return it. */
10583 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
10584 return fold_convert_loc (loc, type, arg0);
10585 /* FALLTHRU */
10586 case TRUTH_OR_EXPR:
10587 /* If either arg is constant zero, drop it. */
10588 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
10589 return non_lvalue_loc (loc, fold_convert_loc (loc, type, arg1));
10590 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
10591 /* Preserve sequence points. */
10592 && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
10593 return non_lvalue_loc (loc, fold_convert_loc (loc, type, arg0));
10594 /* If second arg is constant true, result is true, but we must
10595 evaluate first arg. */
10596 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
10597 return omit_one_operand_loc (loc, type, arg1, arg0);
10598 /* Likewise for first arg, but note this only occurs here for
10599 TRUTH_OR_EXPR. */
10600 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
10601 return omit_one_operand_loc (loc, type, arg0, arg1);
10603 /* !X || X is always true. */
10604 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
10605 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10606 return omit_one_operand_loc (loc, type, integer_one_node, arg1);
10607 /* X || !X is always true. */
10608 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
10609 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10610 return omit_one_operand_loc (loc, type, integer_one_node, arg0);
10612 /* (X && !Y) || (!X && Y) is X ^ Y */
10613 if (TREE_CODE (arg0) == TRUTH_AND_EXPR
10614 && TREE_CODE (arg1) == TRUTH_AND_EXPR)
10616 tree a0, a1, l0, l1, n0, n1;
10618 a0 = fold_convert_loc (loc, type, TREE_OPERAND (arg1, 0));
10619 a1 = fold_convert_loc (loc, type, TREE_OPERAND (arg1, 1));
10621 l0 = fold_convert_loc (loc, type, TREE_OPERAND (arg0, 0));
10622 l1 = fold_convert_loc (loc, type, TREE_OPERAND (arg0, 1));
10624 n0 = fold_build1_loc (loc, TRUTH_NOT_EXPR, type, l0);
10625 n1 = fold_build1_loc (loc, TRUTH_NOT_EXPR, type, l1);
10627 if ((operand_equal_p (n0, a0, 0)
10628 && operand_equal_p (n1, a1, 0))
10629 || (operand_equal_p (n0, a1, 0)
10630 && operand_equal_p (n1, a0, 0)))
10631 return fold_build2_loc (loc, TRUTH_XOR_EXPR, type, l0, n1);
10634 if ((tem = fold_truth_andor (loc, code, type, arg0, arg1, op0, op1))
10635 != NULL_TREE)
10636 return tem;
10638 return NULL_TREE;
10640 case TRUTH_XOR_EXPR:
10641 /* If the second arg is constant zero, drop it. */
10642 if (integer_zerop (arg1))
10643 return non_lvalue_loc (loc, fold_convert_loc (loc, type, arg0));
10644 /* If the second arg is constant true, this is a logical inversion. */
10645 if (integer_onep (arg1))
10647 tem = invert_truthvalue_loc (loc, arg0);
10648 return non_lvalue_loc (loc, fold_convert_loc (loc, type, tem));
10650 /* Identical arguments cancel to zero. */
10651 if (operand_equal_p (arg0, arg1, 0))
10652 return omit_one_operand_loc (loc, type, integer_zero_node, arg0);
10654 /* !X ^ X is always true. */
10655 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
10656 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10657 return omit_one_operand_loc (loc, type, integer_one_node, arg1);
10659 /* X ^ !X is always true. */
10660 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
10661 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10662 return omit_one_operand_loc (loc, type, integer_one_node, arg0);
10664 return NULL_TREE;
10666 case EQ_EXPR:
10667 case NE_EXPR:
10668 STRIP_NOPS (arg0);
10669 STRIP_NOPS (arg1);
10671 tem = fold_comparison (loc, code, type, op0, op1);
10672 if (tem != NULL_TREE)
10673 return tem;
10675 /* bool_var != 1 becomes !bool_var. */
10676 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_onep (arg1)
10677 && code == NE_EXPR)
10678 return fold_convert_loc (loc, type,
10679 fold_build1_loc (loc, TRUTH_NOT_EXPR,
10680 TREE_TYPE (arg0), arg0));
10682 /* bool_var == 0 becomes !bool_var. */
10683 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_zerop (arg1)
10684 && code == EQ_EXPR)
10685 return fold_convert_loc (loc, type,
10686 fold_build1_loc (loc, TRUTH_NOT_EXPR,
10687 TREE_TYPE (arg0), arg0));
10689 /* !exp != 0 becomes !exp */
10690 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR && integer_zerop (arg1)
10691 && code == NE_EXPR)
10692 return non_lvalue_loc (loc, fold_convert_loc (loc, type, arg0));
10694 /* If this is an EQ or NE comparison with zero and ARG0 is
10695 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
10696 two operations, but the latter can be done in one less insn
10697 on machines that have only two-operand insns or on which a
10698 constant cannot be the first operand. */
10699 if (TREE_CODE (arg0) == BIT_AND_EXPR
10700 && integer_zerop (arg1))
10702 tree arg00 = TREE_OPERAND (arg0, 0);
10703 tree arg01 = TREE_OPERAND (arg0, 1);
10704 if (TREE_CODE (arg00) == LSHIFT_EXPR
10705 && integer_onep (TREE_OPERAND (arg00, 0)))
10707 tree tem = fold_build2_loc (loc, RSHIFT_EXPR, TREE_TYPE (arg00),
10708 arg01, TREE_OPERAND (arg00, 1));
10709 tem = fold_build2_loc (loc, BIT_AND_EXPR, TREE_TYPE (arg0), tem,
10710 build_int_cst (TREE_TYPE (arg0), 1));
10711 return fold_build2_loc (loc, code, type,
10712 fold_convert_loc (loc, TREE_TYPE (arg1), tem),
10713 arg1);
10715 else if (TREE_CODE (arg01) == LSHIFT_EXPR
10716 && integer_onep (TREE_OPERAND (arg01, 0)))
10718 tree tem = fold_build2_loc (loc, RSHIFT_EXPR, TREE_TYPE (arg01),
10719 arg00, TREE_OPERAND (arg01, 1));
10720 tem = fold_build2_loc (loc, BIT_AND_EXPR, TREE_TYPE (arg0), tem,
10721 build_int_cst (TREE_TYPE (arg0), 1));
10722 return fold_build2_loc (loc, code, type,
10723 fold_convert_loc (loc, TREE_TYPE (arg1), tem),
10724 arg1);
10728 /* If this is an NE or EQ comparison of zero against the result of a
10729 signed MOD operation whose second operand is a power of 2, make
10730 the MOD operation unsigned since it is simpler and equivalent. */
10731 if (integer_zerop (arg1)
10732 && !TYPE_UNSIGNED (TREE_TYPE (arg0))
10733 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
10734 || TREE_CODE (arg0) == CEIL_MOD_EXPR
10735 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
10736 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
10737 && integer_pow2p (TREE_OPERAND (arg0, 1)))
10739 tree newtype = unsigned_type_for (TREE_TYPE (arg0));
10740 tree newmod = fold_build2_loc (loc, TREE_CODE (arg0), newtype,
10741 fold_convert_loc (loc, newtype,
10742 TREE_OPERAND (arg0, 0)),
10743 fold_convert_loc (loc, newtype,
10744 TREE_OPERAND (arg0, 1)));
10746 return fold_build2_loc (loc, code, type, newmod,
10747 fold_convert_loc (loc, newtype, arg1));
10750 /* Fold ((X >> C1) & C2) == 0 and ((X >> C1) & C2) != 0 where
10751 C1 is a valid shift constant, and C2 is a power of two, i.e.
10752 a single bit. */
10753 if (TREE_CODE (arg0) == BIT_AND_EXPR
10754 && TREE_CODE (TREE_OPERAND (arg0, 0)) == RSHIFT_EXPR
10755 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1))
10756 == INTEGER_CST
10757 && integer_pow2p (TREE_OPERAND (arg0, 1))
10758 && integer_zerop (arg1))
10760 tree itype = TREE_TYPE (arg0);
10761 tree arg001 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 1);
10762 prec = TYPE_PRECISION (itype);
10764 /* Check for a valid shift count. */
10765 if (wi::ltu_p (wi::to_wide (arg001), prec))
10767 tree arg01 = TREE_OPERAND (arg0, 1);
10768 tree arg000 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
10769 unsigned HOST_WIDE_INT log2 = tree_log2 (arg01);
10770 /* If (C2 << C1) doesn't overflow, then ((X >> C1) & C2) != 0
10771 can be rewritten as (X & (C2 << C1)) != 0. */
10772 if ((log2 + TREE_INT_CST_LOW (arg001)) < prec)
10774 tem = fold_build2_loc (loc, LSHIFT_EXPR, itype, arg01, arg001);
10775 tem = fold_build2_loc (loc, BIT_AND_EXPR, itype, arg000, tem);
10776 return fold_build2_loc (loc, code, type, tem,
10777 fold_convert_loc (loc, itype, arg1));
10779 /* Otherwise, for signed (arithmetic) shifts,
10780 ((X >> C1) & C2) != 0 is rewritten as X < 0, and
10781 ((X >> C1) & C2) == 0 is rewritten as X >= 0. */
10782 else if (!TYPE_UNSIGNED (itype))
10783 return fold_build2_loc (loc, code == EQ_EXPR ? GE_EXPR : LT_EXPR, type,
10784 arg000, build_int_cst (itype, 0));
10785 /* Otherwise, of unsigned (logical) shifts,
10786 ((X >> C1) & C2) != 0 is rewritten as (X,false), and
10787 ((X >> C1) & C2) == 0 is rewritten as (X,true). */
10788 else
10789 return omit_one_operand_loc (loc, type,
10790 code == EQ_EXPR ? integer_one_node
10791 : integer_zero_node,
10792 arg000);
10796 /* If this is a comparison of a field, we may be able to simplify it. */
10797 if ((TREE_CODE (arg0) == COMPONENT_REF
10798 || TREE_CODE (arg0) == BIT_FIELD_REF)
10799 /* Handle the constant case even without -O
10800 to make sure the warnings are given. */
10801 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
10803 t1 = optimize_bit_field_compare (loc, code, type, arg0, arg1);
10804 if (t1)
10805 return t1;
10808 /* Optimize comparisons of strlen vs zero to a compare of the
10809 first character of the string vs zero. To wit,
10810 strlen(ptr) == 0 => *ptr == 0
10811 strlen(ptr) != 0 => *ptr != 0
10812 Other cases should reduce to one of these two (or a constant)
10813 due to the return value of strlen being unsigned. */
10814 if (TREE_CODE (arg0) == CALL_EXPR
10815 && integer_zerop (arg1))
10817 tree fndecl = get_callee_fndecl (arg0);
10819 if (fndecl
10820 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
10821 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
10822 && call_expr_nargs (arg0) == 1
10823 && TREE_CODE (TREE_TYPE (CALL_EXPR_ARG (arg0, 0))) == POINTER_TYPE)
10825 tree iref = build_fold_indirect_ref_loc (loc,
10826 CALL_EXPR_ARG (arg0, 0));
10827 return fold_build2_loc (loc, code, type, iref,
10828 build_int_cst (TREE_TYPE (iref), 0));
10832 /* Fold (X >> C) != 0 into X < 0 if C is one less than the width
10833 of X. Similarly fold (X >> C) == 0 into X >= 0. */
10834 if (TREE_CODE (arg0) == RSHIFT_EXPR
10835 && integer_zerop (arg1)
10836 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
10838 tree arg00 = TREE_OPERAND (arg0, 0);
10839 tree arg01 = TREE_OPERAND (arg0, 1);
10840 tree itype = TREE_TYPE (arg00);
10841 if (wi::to_wide (arg01) == element_precision (itype) - 1)
10843 if (TYPE_UNSIGNED (itype))
10845 itype = signed_type_for (itype);
10846 arg00 = fold_convert_loc (loc, itype, arg00);
10848 return fold_build2_loc (loc, code == EQ_EXPR ? GE_EXPR : LT_EXPR,
10849 type, arg00, build_zero_cst (itype));
10853 /* Fold (~X & C) == 0 into (X & C) != 0 and (~X & C) != 0 into
10854 (X & C) == 0 when C is a single bit. */
10855 if (TREE_CODE (arg0) == BIT_AND_EXPR
10856 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_NOT_EXPR
10857 && integer_zerop (arg1)
10858 && integer_pow2p (TREE_OPERAND (arg0, 1)))
10860 tem = fold_build2_loc (loc, BIT_AND_EXPR, TREE_TYPE (arg0),
10861 TREE_OPERAND (TREE_OPERAND (arg0, 0), 0),
10862 TREE_OPERAND (arg0, 1));
10863 return fold_build2_loc (loc, code == EQ_EXPR ? NE_EXPR : EQ_EXPR,
10864 type, tem,
10865 fold_convert_loc (loc, TREE_TYPE (arg0),
10866 arg1));
10869 /* Fold ((X & C) ^ C) eq/ne 0 into (X & C) ne/eq 0, when the
10870 constant C is a power of two, i.e. a single bit. */
10871 if (TREE_CODE (arg0) == BIT_XOR_EXPR
10872 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
10873 && integer_zerop (arg1)
10874 && integer_pow2p (TREE_OPERAND (arg0, 1))
10875 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
10876 TREE_OPERAND (arg0, 1), OEP_ONLY_CONST))
10878 tree arg00 = TREE_OPERAND (arg0, 0);
10879 return fold_build2_loc (loc, code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
10880 arg00, build_int_cst (TREE_TYPE (arg00), 0));
10883 /* Likewise, fold ((X ^ C) & C) eq/ne 0 into (X & C) ne/eq 0,
10884 when is C is a power of two, i.e. a single bit. */
10885 if (TREE_CODE (arg0) == BIT_AND_EXPR
10886 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_XOR_EXPR
10887 && integer_zerop (arg1)
10888 && integer_pow2p (TREE_OPERAND (arg0, 1))
10889 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
10890 TREE_OPERAND (arg0, 1), OEP_ONLY_CONST))
10892 tree arg000 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
10893 tem = fold_build2_loc (loc, BIT_AND_EXPR, TREE_TYPE (arg000),
10894 arg000, TREE_OPERAND (arg0, 1));
10895 return fold_build2_loc (loc, code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
10896 tem, build_int_cst (TREE_TYPE (tem), 0));
10899 if (integer_zerop (arg1)
10900 && tree_expr_nonzero_p (arg0))
10902 tree res = constant_boolean_node (code==NE_EXPR, type);
10903 return omit_one_operand_loc (loc, type, res, arg0);
10906 /* Fold (X & C) op (Y & C) as (X ^ Y) & C op 0", and symmetries. */
10907 if (TREE_CODE (arg0) == BIT_AND_EXPR
10908 && TREE_CODE (arg1) == BIT_AND_EXPR)
10910 tree arg00 = TREE_OPERAND (arg0, 0);
10911 tree arg01 = TREE_OPERAND (arg0, 1);
10912 tree arg10 = TREE_OPERAND (arg1, 0);
10913 tree arg11 = TREE_OPERAND (arg1, 1);
10914 tree itype = TREE_TYPE (arg0);
10916 if (operand_equal_p (arg01, arg11, 0))
10918 tem = fold_convert_loc (loc, itype, arg10);
10919 tem = fold_build2_loc (loc, BIT_XOR_EXPR, itype, arg00, tem);
10920 tem = fold_build2_loc (loc, BIT_AND_EXPR, itype, tem, arg01);
10921 return fold_build2_loc (loc, code, type, tem,
10922 build_zero_cst (itype));
10924 if (operand_equal_p (arg01, arg10, 0))
10926 tem = fold_convert_loc (loc, itype, arg11);
10927 tem = fold_build2_loc (loc, BIT_XOR_EXPR, itype, arg00, tem);
10928 tem = fold_build2_loc (loc, BIT_AND_EXPR, itype, tem, arg01);
10929 return fold_build2_loc (loc, code, type, tem,
10930 build_zero_cst (itype));
10932 if (operand_equal_p (arg00, arg11, 0))
10934 tem = fold_convert_loc (loc, itype, arg10);
10935 tem = fold_build2_loc (loc, BIT_XOR_EXPR, itype, arg01, tem);
10936 tem = fold_build2_loc (loc, BIT_AND_EXPR, itype, tem, arg00);
10937 return fold_build2_loc (loc, code, type, tem,
10938 build_zero_cst (itype));
10940 if (operand_equal_p (arg00, arg10, 0))
10942 tem = fold_convert_loc (loc, itype, arg11);
10943 tem = fold_build2_loc (loc, BIT_XOR_EXPR, itype, arg01, tem);
10944 tem = fold_build2_loc (loc, BIT_AND_EXPR, itype, tem, arg00);
10945 return fold_build2_loc (loc, code, type, tem,
10946 build_zero_cst (itype));
10950 if (TREE_CODE (arg0) == BIT_XOR_EXPR
10951 && TREE_CODE (arg1) == BIT_XOR_EXPR)
10953 tree arg00 = TREE_OPERAND (arg0, 0);
10954 tree arg01 = TREE_OPERAND (arg0, 1);
10955 tree arg10 = TREE_OPERAND (arg1, 0);
10956 tree arg11 = TREE_OPERAND (arg1, 1);
10957 tree itype = TREE_TYPE (arg0);
10959 /* Optimize (X ^ Z) op (Y ^ Z) as X op Y, and symmetries.
10960 operand_equal_p guarantees no side-effects so we don't need
10961 to use omit_one_operand on Z. */
10962 if (operand_equal_p (arg01, arg11, 0))
10963 return fold_build2_loc (loc, code, type, arg00,
10964 fold_convert_loc (loc, TREE_TYPE (arg00),
10965 arg10));
10966 if (operand_equal_p (arg01, arg10, 0))
10967 return fold_build2_loc (loc, code, type, arg00,
10968 fold_convert_loc (loc, TREE_TYPE (arg00),
10969 arg11));
10970 if (operand_equal_p (arg00, arg11, 0))
10971 return fold_build2_loc (loc, code, type, arg01,
10972 fold_convert_loc (loc, TREE_TYPE (arg01),
10973 arg10));
10974 if (operand_equal_p (arg00, arg10, 0))
10975 return fold_build2_loc (loc, code, type, arg01,
10976 fold_convert_loc (loc, TREE_TYPE (arg01),
10977 arg11));
10979 /* Optimize (X ^ C1) op (Y ^ C2) as (X ^ (C1 ^ C2)) op Y. */
10980 if (TREE_CODE (arg01) == INTEGER_CST
10981 && TREE_CODE (arg11) == INTEGER_CST)
10983 tem = fold_build2_loc (loc, BIT_XOR_EXPR, itype, arg01,
10984 fold_convert_loc (loc, itype, arg11));
10985 tem = fold_build2_loc (loc, BIT_XOR_EXPR, itype, arg00, tem);
10986 return fold_build2_loc (loc, code, type, tem,
10987 fold_convert_loc (loc, itype, arg10));
10991 /* Attempt to simplify equality/inequality comparisons of complex
10992 values. Only lower the comparison if the result is known or
10993 can be simplified to a single scalar comparison. */
10994 if ((TREE_CODE (arg0) == COMPLEX_EXPR
10995 || TREE_CODE (arg0) == COMPLEX_CST)
10996 && (TREE_CODE (arg1) == COMPLEX_EXPR
10997 || TREE_CODE (arg1) == COMPLEX_CST))
10999 tree real0, imag0, real1, imag1;
11000 tree rcond, icond;
11002 if (TREE_CODE (arg0) == COMPLEX_EXPR)
11004 real0 = TREE_OPERAND (arg0, 0);
11005 imag0 = TREE_OPERAND (arg0, 1);
11007 else
11009 real0 = TREE_REALPART (arg0);
11010 imag0 = TREE_IMAGPART (arg0);
11013 if (TREE_CODE (arg1) == COMPLEX_EXPR)
11015 real1 = TREE_OPERAND (arg1, 0);
11016 imag1 = TREE_OPERAND (arg1, 1);
11018 else
11020 real1 = TREE_REALPART (arg1);
11021 imag1 = TREE_IMAGPART (arg1);
11024 rcond = fold_binary_loc (loc, code, type, real0, real1);
11025 if (rcond && TREE_CODE (rcond) == INTEGER_CST)
11027 if (integer_zerop (rcond))
11029 if (code == EQ_EXPR)
11030 return omit_two_operands_loc (loc, type, boolean_false_node,
11031 imag0, imag1);
11032 return fold_build2_loc (loc, NE_EXPR, type, imag0, imag1);
11034 else
11036 if (code == NE_EXPR)
11037 return omit_two_operands_loc (loc, type, boolean_true_node,
11038 imag0, imag1);
11039 return fold_build2_loc (loc, EQ_EXPR, type, imag0, imag1);
11043 icond = fold_binary_loc (loc, code, type, imag0, imag1);
11044 if (icond && TREE_CODE (icond) == INTEGER_CST)
11046 if (integer_zerop (icond))
11048 if (code == EQ_EXPR)
11049 return omit_two_operands_loc (loc, type, boolean_false_node,
11050 real0, real1);
11051 return fold_build2_loc (loc, NE_EXPR, type, real0, real1);
11053 else
11055 if (code == NE_EXPR)
11056 return omit_two_operands_loc (loc, type, boolean_true_node,
11057 real0, real1);
11058 return fold_build2_loc (loc, EQ_EXPR, type, real0, real1);
11063 return NULL_TREE;
11065 case LT_EXPR:
11066 case GT_EXPR:
11067 case LE_EXPR:
11068 case GE_EXPR:
11069 tem = fold_comparison (loc, code, type, op0, op1);
11070 if (tem != NULL_TREE)
11071 return tem;
11073 /* Transform comparisons of the form X +- C CMP X. */
11074 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
11075 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
11076 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
11077 && !HONOR_SNANS (arg0))
11079 tree arg01 = TREE_OPERAND (arg0, 1);
11080 enum tree_code code0 = TREE_CODE (arg0);
11081 int is_positive = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg01)) ? -1 : 1;
11083 /* (X - c) > X becomes false. */
11084 if (code == GT_EXPR
11085 && ((code0 == MINUS_EXPR && is_positive >= 0)
11086 || (code0 == PLUS_EXPR && is_positive <= 0)))
11087 return constant_boolean_node (0, type);
11089 /* Likewise (X + c) < X becomes false. */
11090 if (code == LT_EXPR
11091 && ((code0 == PLUS_EXPR && is_positive >= 0)
11092 || (code0 == MINUS_EXPR && is_positive <= 0)))
11093 return constant_boolean_node (0, type);
11095 /* Convert (X - c) <= X to true. */
11096 if (!HONOR_NANS (arg1)
11097 && code == LE_EXPR
11098 && ((code0 == MINUS_EXPR && is_positive >= 0)
11099 || (code0 == PLUS_EXPR && is_positive <= 0)))
11100 return constant_boolean_node (1, type);
11102 /* Convert (X + c) >= X to true. */
11103 if (!HONOR_NANS (arg1)
11104 && code == GE_EXPR
11105 && ((code0 == PLUS_EXPR && is_positive >= 0)
11106 || (code0 == MINUS_EXPR && is_positive <= 0)))
11107 return constant_boolean_node (1, type);
11110 /* If we are comparing an ABS_EXPR with a constant, we can
11111 convert all the cases into explicit comparisons, but they may
11112 well not be faster than doing the ABS and one comparison.
11113 But ABS (X) <= C is a range comparison, which becomes a subtraction
11114 and a comparison, and is probably faster. */
11115 if (code == LE_EXPR
11116 && TREE_CODE (arg1) == INTEGER_CST
11117 && TREE_CODE (arg0) == ABS_EXPR
11118 && ! TREE_SIDE_EFFECTS (arg0)
11119 && (tem = negate_expr (arg1)) != 0
11120 && TREE_CODE (tem) == INTEGER_CST
11121 && !TREE_OVERFLOW (tem))
11122 return fold_build2_loc (loc, TRUTH_ANDIF_EXPR, type,
11123 build2 (GE_EXPR, type,
11124 TREE_OPERAND (arg0, 0), tem),
11125 build2 (LE_EXPR, type,
11126 TREE_OPERAND (arg0, 0), arg1));
11128 /* Convert ABS_EXPR<x> >= 0 to true. */
11129 strict_overflow_p = false;
11130 if (code == GE_EXPR
11131 && (integer_zerop (arg1)
11132 || (! HONOR_NANS (arg0)
11133 && real_zerop (arg1)))
11134 && tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p))
11136 if (strict_overflow_p)
11137 fold_overflow_warning (("assuming signed overflow does not occur "
11138 "when simplifying comparison of "
11139 "absolute value and zero"),
11140 WARN_STRICT_OVERFLOW_CONDITIONAL);
11141 return omit_one_operand_loc (loc, type,
11142 constant_boolean_node (true, type),
11143 arg0);
11146 /* Convert ABS_EXPR<x> < 0 to false. */
11147 strict_overflow_p = false;
11148 if (code == LT_EXPR
11149 && (integer_zerop (arg1) || real_zerop (arg1))
11150 && tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p))
11152 if (strict_overflow_p)
11153 fold_overflow_warning (("assuming signed overflow does not occur "
11154 "when simplifying comparison of "
11155 "absolute value and zero"),
11156 WARN_STRICT_OVERFLOW_CONDITIONAL);
11157 return omit_one_operand_loc (loc, type,
11158 constant_boolean_node (false, type),
11159 arg0);
11162 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
11163 and similarly for >= into !=. */
11164 if ((code == LT_EXPR || code == GE_EXPR)
11165 && TYPE_UNSIGNED (TREE_TYPE (arg0))
11166 && TREE_CODE (arg1) == LSHIFT_EXPR
11167 && integer_onep (TREE_OPERAND (arg1, 0)))
11168 return build2_loc (loc, code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
11169 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
11170 TREE_OPERAND (arg1, 1)),
11171 build_zero_cst (TREE_TYPE (arg0)));
11173 /* Similarly for X < (cast) (1 << Y). But cast can't be narrowing,
11174 otherwise Y might be >= # of bits in X's type and thus e.g.
11175 (unsigned char) (1 << Y) for Y 15 might be 0.
11176 If the cast is widening, then 1 << Y should have unsigned type,
11177 otherwise if Y is number of bits in the signed shift type minus 1,
11178 we can't optimize this. E.g. (unsigned long long) (1 << Y) for Y
11179 31 might be 0xffffffff80000000. */
11180 if ((code == LT_EXPR || code == GE_EXPR)
11181 && TYPE_UNSIGNED (TREE_TYPE (arg0))
11182 && CONVERT_EXPR_P (arg1)
11183 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
11184 && (element_precision (TREE_TYPE (arg1))
11185 >= element_precision (TREE_TYPE (TREE_OPERAND (arg1, 0))))
11186 && (TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg1, 0)))
11187 || (element_precision (TREE_TYPE (arg1))
11188 == element_precision (TREE_TYPE (TREE_OPERAND (arg1, 0)))))
11189 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
11191 tem = build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
11192 TREE_OPERAND (TREE_OPERAND (arg1, 0), 1));
11193 return build2_loc (loc, code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
11194 fold_convert_loc (loc, TREE_TYPE (arg0), tem),
11195 build_zero_cst (TREE_TYPE (arg0)));
11198 return NULL_TREE;
11200 case UNORDERED_EXPR:
11201 case ORDERED_EXPR:
11202 case UNLT_EXPR:
11203 case UNLE_EXPR:
11204 case UNGT_EXPR:
11205 case UNGE_EXPR:
11206 case UNEQ_EXPR:
11207 case LTGT_EXPR:
11208 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
11210 tree targ0 = strip_float_extensions (arg0);
11211 tree targ1 = strip_float_extensions (arg1);
11212 tree newtype = TREE_TYPE (targ0);
11214 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
11215 newtype = TREE_TYPE (targ1);
11217 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
11218 return fold_build2_loc (loc, code, type,
11219 fold_convert_loc (loc, newtype, targ0),
11220 fold_convert_loc (loc, newtype, targ1));
11223 return NULL_TREE;
11225 case COMPOUND_EXPR:
11226 /* When pedantic, a compound expression can be neither an lvalue
11227 nor an integer constant expression. */
11228 if (TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
11229 return NULL_TREE;
11230 /* Don't let (0, 0) be null pointer constant. */
11231 tem = integer_zerop (arg1) ? build1 (NOP_EXPR, type, arg1)
11232 : fold_convert_loc (loc, type, arg1);
11233 return pedantic_non_lvalue_loc (loc, tem);
11235 case ASSERT_EXPR:
11236 /* An ASSERT_EXPR should never be passed to fold_binary. */
11237 gcc_unreachable ();
11239 default:
11240 return NULL_TREE;
11241 } /* switch (code) */
11244 /* Used by contains_label_[p1]. */
11246 struct contains_label_data
11248 hash_set<tree> *pset;
11249 bool inside_switch_p;
11252 /* Callback for walk_tree, looking for LABEL_EXPR. Return *TP if it is
11253 a LABEL_EXPR or CASE_LABEL_EXPR not inside of another SWITCH_EXPR; otherwise
11254 return NULL_TREE. Do not check the subtrees of GOTO_EXPR. */
11256 static tree
11257 contains_label_1 (tree *tp, int *walk_subtrees, void *data)
11259 contains_label_data *d = (contains_label_data *) data;
11260 switch (TREE_CODE (*tp))
11262 case LABEL_EXPR:
11263 return *tp;
11265 case CASE_LABEL_EXPR:
11266 if (!d->inside_switch_p)
11267 return *tp;
11268 return NULL_TREE;
11270 case SWITCH_EXPR:
11271 if (!d->inside_switch_p)
11273 if (walk_tree (&SWITCH_COND (*tp), contains_label_1, data, d->pset))
11274 return *tp;
11275 d->inside_switch_p = true;
11276 if (walk_tree (&SWITCH_BODY (*tp), contains_label_1, data, d->pset))
11277 return *tp;
11278 d->inside_switch_p = false;
11279 *walk_subtrees = 0;
11281 return NULL_TREE;
11283 case GOTO_EXPR:
11284 *walk_subtrees = 0;
11285 return NULL_TREE;
11287 default:
11288 return NULL_TREE;
11292 /* Return whether the sub-tree ST contains a label which is accessible from
11293 outside the sub-tree. */
11295 static bool
11296 contains_label_p (tree st)
11298 hash_set<tree> pset;
11299 contains_label_data data = { &pset, false };
11300 return walk_tree (&st, contains_label_1, &data, &pset) != NULL_TREE;
11303 /* Fold a ternary expression of code CODE and type TYPE with operands
11304 OP0, OP1, and OP2. Return the folded expression if folding is
11305 successful. Otherwise, return NULL_TREE. */
11307 tree
11308 fold_ternary_loc (location_t loc, enum tree_code code, tree type,
11309 tree op0, tree op1, tree op2)
11311 tree tem;
11312 tree arg0 = NULL_TREE, arg1 = NULL_TREE, arg2 = NULL_TREE;
11313 enum tree_code_class kind = TREE_CODE_CLASS (code);
11315 gcc_assert (IS_EXPR_CODE_CLASS (kind)
11316 && TREE_CODE_LENGTH (code) == 3);
11318 /* If this is a commutative operation, and OP0 is a constant, move it
11319 to OP1 to reduce the number of tests below. */
11320 if (commutative_ternary_tree_code (code)
11321 && tree_swap_operands_p (op0, op1))
11322 return fold_build3_loc (loc, code, type, op1, op0, op2);
11324 tem = generic_simplify (loc, code, type, op0, op1, op2);
11325 if (tem)
11326 return tem;
11328 /* Strip any conversions that don't change the mode. This is safe
11329 for every expression, except for a comparison expression because
11330 its signedness is derived from its operands. So, in the latter
11331 case, only strip conversions that don't change the signedness.
11333 Note that this is done as an internal manipulation within the
11334 constant folder, in order to find the simplest representation of
11335 the arguments so that their form can be studied. In any cases,
11336 the appropriate type conversions should be put back in the tree
11337 that will get out of the constant folder. */
11338 if (op0)
11340 arg0 = op0;
11341 STRIP_NOPS (arg0);
11344 if (op1)
11346 arg1 = op1;
11347 STRIP_NOPS (arg1);
11350 if (op2)
11352 arg2 = op2;
11353 STRIP_NOPS (arg2);
11356 switch (code)
11358 case COMPONENT_REF:
11359 if (TREE_CODE (arg0) == CONSTRUCTOR
11360 && ! type_contains_placeholder_p (TREE_TYPE (arg0)))
11362 unsigned HOST_WIDE_INT idx;
11363 tree field, value;
11364 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (arg0), idx, field, value)
11365 if (field == arg1)
11366 return value;
11368 return NULL_TREE;
11370 case COND_EXPR:
11371 case VEC_COND_EXPR:
11372 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
11373 so all simple results must be passed through pedantic_non_lvalue. */
11374 if (TREE_CODE (arg0) == INTEGER_CST)
11376 tree unused_op = integer_zerop (arg0) ? op1 : op2;
11377 tem = integer_zerop (arg0) ? op2 : op1;
11378 /* Only optimize constant conditions when the selected branch
11379 has the same type as the COND_EXPR. This avoids optimizing
11380 away "c ? x : throw", where the throw has a void type.
11381 Avoid throwing away that operand which contains label. */
11382 if ((!TREE_SIDE_EFFECTS (unused_op)
11383 || !contains_label_p (unused_op))
11384 && (! VOID_TYPE_P (TREE_TYPE (tem))
11385 || VOID_TYPE_P (type)))
11386 return pedantic_non_lvalue_loc (loc, tem);
11387 return NULL_TREE;
11389 else if (TREE_CODE (arg0) == VECTOR_CST)
11391 unsigned HOST_WIDE_INT nelts;
11392 if ((TREE_CODE (arg1) == VECTOR_CST
11393 || TREE_CODE (arg1) == CONSTRUCTOR)
11394 && (TREE_CODE (arg2) == VECTOR_CST
11395 || TREE_CODE (arg2) == CONSTRUCTOR)
11396 && TYPE_VECTOR_SUBPARTS (type).is_constant (&nelts))
11398 vec_perm_builder sel (nelts, nelts, 1);
11399 for (unsigned int i = 0; i < nelts; i++)
11401 tree val = VECTOR_CST_ELT (arg0, i);
11402 if (integer_all_onesp (val))
11403 sel.quick_push (i);
11404 else if (integer_zerop (val))
11405 sel.quick_push (nelts + i);
11406 else /* Currently unreachable. */
11407 return NULL_TREE;
11409 vec_perm_indices indices (sel, 2, nelts);
11410 tree t = fold_vec_perm (type, arg1, arg2, indices);
11411 if (t != NULL_TREE)
11412 return t;
11416 /* If we have A op B ? A : C, we may be able to convert this to a
11417 simpler expression, depending on the operation and the values
11418 of B and C. Signed zeros prevent all of these transformations,
11419 for reasons given above each one.
11421 Also try swapping the arguments and inverting the conditional. */
11422 if (COMPARISON_CLASS_P (arg0)
11423 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0), op1)
11424 && !HONOR_SIGNED_ZEROS (element_mode (op1)))
11426 tem = fold_cond_expr_with_comparison (loc, type, arg0, op1, op2);
11427 if (tem)
11428 return tem;
11431 if (COMPARISON_CLASS_P (arg0)
11432 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0), op2)
11433 && !HONOR_SIGNED_ZEROS (element_mode (op2)))
11435 location_t loc0 = expr_location_or (arg0, loc);
11436 tem = fold_invert_truthvalue (loc0, arg0);
11437 if (tem && COMPARISON_CLASS_P (tem))
11439 tem = fold_cond_expr_with_comparison (loc, type, tem, op2, op1);
11440 if (tem)
11441 return tem;
11445 /* If the second operand is simpler than the third, swap them
11446 since that produces better jump optimization results. */
11447 if (truth_value_p (TREE_CODE (arg0))
11448 && tree_swap_operands_p (op1, op2))
11450 location_t loc0 = expr_location_or (arg0, loc);
11451 /* See if this can be inverted. If it can't, possibly because
11452 it was a floating-point inequality comparison, don't do
11453 anything. */
11454 tem = fold_invert_truthvalue (loc0, arg0);
11455 if (tem)
11456 return fold_build3_loc (loc, code, type, tem, op2, op1);
11459 /* Convert A ? 1 : 0 to simply A. */
11460 if ((code == VEC_COND_EXPR ? integer_all_onesp (op1)
11461 : (integer_onep (op1)
11462 && !VECTOR_TYPE_P (type)))
11463 && integer_zerop (op2)
11464 /* If we try to convert OP0 to our type, the
11465 call to fold will try to move the conversion inside
11466 a COND, which will recurse. In that case, the COND_EXPR
11467 is probably the best choice, so leave it alone. */
11468 && type == TREE_TYPE (arg0))
11469 return pedantic_non_lvalue_loc (loc, arg0);
11471 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
11472 over COND_EXPR in cases such as floating point comparisons. */
11473 if (integer_zerop (op1)
11474 && code == COND_EXPR
11475 && integer_onep (op2)
11476 && !VECTOR_TYPE_P (type)
11477 && truth_value_p (TREE_CODE (arg0)))
11478 return pedantic_non_lvalue_loc (loc,
11479 fold_convert_loc (loc, type,
11480 invert_truthvalue_loc (loc,
11481 arg0)));
11483 /* A < 0 ? <sign bit of A> : 0 is simply (A & <sign bit of A>). */
11484 if (TREE_CODE (arg0) == LT_EXPR
11485 && integer_zerop (TREE_OPERAND (arg0, 1))
11486 && integer_zerop (op2)
11487 && (tem = sign_bit_p (TREE_OPERAND (arg0, 0), arg1)))
11489 /* sign_bit_p looks through both zero and sign extensions,
11490 but for this optimization only sign extensions are
11491 usable. */
11492 tree tem2 = TREE_OPERAND (arg0, 0);
11493 while (tem != tem2)
11495 if (TREE_CODE (tem2) != NOP_EXPR
11496 || TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (tem2, 0))))
11498 tem = NULL_TREE;
11499 break;
11501 tem2 = TREE_OPERAND (tem2, 0);
11503 /* sign_bit_p only checks ARG1 bits within A's precision.
11504 If <sign bit of A> has wider type than A, bits outside
11505 of A's precision in <sign bit of A> need to be checked.
11506 If they are all 0, this optimization needs to be done
11507 in unsigned A's type, if they are all 1 in signed A's type,
11508 otherwise this can't be done. */
11509 if (tem
11510 && TYPE_PRECISION (TREE_TYPE (tem))
11511 < TYPE_PRECISION (TREE_TYPE (arg1))
11512 && TYPE_PRECISION (TREE_TYPE (tem))
11513 < TYPE_PRECISION (type))
11515 int inner_width, outer_width;
11516 tree tem_type;
11518 inner_width = TYPE_PRECISION (TREE_TYPE (tem));
11519 outer_width = TYPE_PRECISION (TREE_TYPE (arg1));
11520 if (outer_width > TYPE_PRECISION (type))
11521 outer_width = TYPE_PRECISION (type);
11523 wide_int mask = wi::shifted_mask
11524 (inner_width, outer_width - inner_width, false,
11525 TYPE_PRECISION (TREE_TYPE (arg1)));
11527 wide_int common = mask & wi::to_wide (arg1);
11528 if (common == mask)
11530 tem_type = signed_type_for (TREE_TYPE (tem));
11531 tem = fold_convert_loc (loc, tem_type, tem);
11533 else if (common == 0)
11535 tem_type = unsigned_type_for (TREE_TYPE (tem));
11536 tem = fold_convert_loc (loc, tem_type, tem);
11538 else
11539 tem = NULL;
11542 if (tem)
11543 return
11544 fold_convert_loc (loc, type,
11545 fold_build2_loc (loc, BIT_AND_EXPR,
11546 TREE_TYPE (tem), tem,
11547 fold_convert_loc (loc,
11548 TREE_TYPE (tem),
11549 arg1)));
11552 /* (A >> N) & 1 ? (1 << N) : 0 is simply A & (1 << N). A & 1 was
11553 already handled above. */
11554 if (TREE_CODE (arg0) == BIT_AND_EXPR
11555 && integer_onep (TREE_OPERAND (arg0, 1))
11556 && integer_zerop (op2)
11557 && integer_pow2p (arg1))
11559 tree tem = TREE_OPERAND (arg0, 0);
11560 STRIP_NOPS (tem);
11561 if (TREE_CODE (tem) == RSHIFT_EXPR
11562 && tree_fits_uhwi_p (TREE_OPERAND (tem, 1))
11563 && (unsigned HOST_WIDE_INT) tree_log2 (arg1)
11564 == tree_to_uhwi (TREE_OPERAND (tem, 1)))
11565 return fold_build2_loc (loc, BIT_AND_EXPR, type,
11566 fold_convert_loc (loc, type,
11567 TREE_OPERAND (tem, 0)),
11568 op1);
11571 /* A & N ? N : 0 is simply A & N if N is a power of two. This
11572 is probably obsolete because the first operand should be a
11573 truth value (that's why we have the two cases above), but let's
11574 leave it in until we can confirm this for all front-ends. */
11575 if (integer_zerop (op2)
11576 && TREE_CODE (arg0) == NE_EXPR
11577 && integer_zerop (TREE_OPERAND (arg0, 1))
11578 && integer_pow2p (arg1)
11579 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
11580 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
11581 arg1, OEP_ONLY_CONST))
11582 return pedantic_non_lvalue_loc (loc,
11583 fold_convert_loc (loc, type,
11584 TREE_OPERAND (arg0, 0)));
11586 /* Disable the transformations below for vectors, since
11587 fold_binary_op_with_conditional_arg may undo them immediately,
11588 yielding an infinite loop. */
11589 if (code == VEC_COND_EXPR)
11590 return NULL_TREE;
11592 /* Convert A ? B : 0 into A && B if A and B are truth values. */
11593 if (integer_zerop (op2)
11594 && truth_value_p (TREE_CODE (arg0))
11595 && truth_value_p (TREE_CODE (arg1))
11596 && (code == VEC_COND_EXPR || !VECTOR_TYPE_P (type)))
11597 return fold_build2_loc (loc, code == VEC_COND_EXPR ? BIT_AND_EXPR
11598 : TRUTH_ANDIF_EXPR,
11599 type, fold_convert_loc (loc, type, arg0), op1);
11601 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
11602 if (code == VEC_COND_EXPR ? integer_all_onesp (op2) : integer_onep (op2)
11603 && truth_value_p (TREE_CODE (arg0))
11604 && truth_value_p (TREE_CODE (arg1))
11605 && (code == VEC_COND_EXPR || !VECTOR_TYPE_P (type)))
11607 location_t loc0 = expr_location_or (arg0, loc);
11608 /* Only perform transformation if ARG0 is easily inverted. */
11609 tem = fold_invert_truthvalue (loc0, arg0);
11610 if (tem)
11611 return fold_build2_loc (loc, code == VEC_COND_EXPR
11612 ? BIT_IOR_EXPR
11613 : TRUTH_ORIF_EXPR,
11614 type, fold_convert_loc (loc, type, tem),
11615 op1);
11618 /* Convert A ? 0 : B into !A && B if A and B are truth values. */
11619 if (integer_zerop (arg1)
11620 && truth_value_p (TREE_CODE (arg0))
11621 && truth_value_p (TREE_CODE (op2))
11622 && (code == VEC_COND_EXPR || !VECTOR_TYPE_P (type)))
11624 location_t loc0 = expr_location_or (arg0, loc);
11625 /* Only perform transformation if ARG0 is easily inverted. */
11626 tem = fold_invert_truthvalue (loc0, arg0);
11627 if (tem)
11628 return fold_build2_loc (loc, code == VEC_COND_EXPR
11629 ? BIT_AND_EXPR : TRUTH_ANDIF_EXPR,
11630 type, fold_convert_loc (loc, type, tem),
11631 op2);
11634 /* Convert A ? 1 : B into A || B if A and B are truth values. */
11635 if (code == VEC_COND_EXPR ? integer_all_onesp (arg1) : integer_onep (arg1)
11636 && truth_value_p (TREE_CODE (arg0))
11637 && truth_value_p (TREE_CODE (op2))
11638 && (code == VEC_COND_EXPR || !VECTOR_TYPE_P (type)))
11639 return fold_build2_loc (loc, code == VEC_COND_EXPR
11640 ? BIT_IOR_EXPR : TRUTH_ORIF_EXPR,
11641 type, fold_convert_loc (loc, type, arg0), op2);
11643 return NULL_TREE;
11645 case CALL_EXPR:
11646 /* CALL_EXPRs used to be ternary exprs. Catch any mistaken uses
11647 of fold_ternary on them. */
11648 gcc_unreachable ();
11650 case BIT_FIELD_REF:
11651 if (TREE_CODE (arg0) == VECTOR_CST
11652 && (type == TREE_TYPE (TREE_TYPE (arg0))
11653 || (TREE_CODE (type) == VECTOR_TYPE
11654 && TREE_TYPE (type) == TREE_TYPE (TREE_TYPE (arg0))))
11655 && tree_fits_uhwi_p (op1)
11656 && tree_fits_uhwi_p (op2))
11658 tree eltype = TREE_TYPE (TREE_TYPE (arg0));
11659 unsigned HOST_WIDE_INT width = tree_to_uhwi (TYPE_SIZE (eltype));
11660 unsigned HOST_WIDE_INT n = tree_to_uhwi (arg1);
11661 unsigned HOST_WIDE_INT idx = tree_to_uhwi (op2);
11663 if (n != 0
11664 && (idx % width) == 0
11665 && (n % width) == 0
11666 && known_le ((idx + n) / width,
11667 TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0))))
11669 idx = idx / width;
11670 n = n / width;
11672 if (TREE_CODE (arg0) == VECTOR_CST)
11674 if (n == 1)
11675 return VECTOR_CST_ELT (arg0, idx);
11677 tree_vector_builder vals (type, n, 1);
11678 for (unsigned i = 0; i < n; ++i)
11679 vals.quick_push (VECTOR_CST_ELT (arg0, idx + i));
11680 return vals.build ();
11685 /* On constants we can use native encode/interpret to constant
11686 fold (nearly) all BIT_FIELD_REFs. */
11687 if (CONSTANT_CLASS_P (arg0)
11688 && can_native_interpret_type_p (type)
11689 && BITS_PER_UNIT == 8
11690 && tree_fits_uhwi_p (op1)
11691 && tree_fits_uhwi_p (op2))
11693 unsigned HOST_WIDE_INT bitpos = tree_to_uhwi (op2);
11694 unsigned HOST_WIDE_INT bitsize = tree_to_uhwi (op1);
11695 /* Limit us to a reasonable amount of work. To relax the
11696 other limitations we need bit-shifting of the buffer
11697 and rounding up the size. */
11698 if (bitpos % BITS_PER_UNIT == 0
11699 && bitsize % BITS_PER_UNIT == 0
11700 && bitsize <= MAX_BITSIZE_MODE_ANY_MODE)
11702 unsigned char b[MAX_BITSIZE_MODE_ANY_MODE / BITS_PER_UNIT];
11703 unsigned HOST_WIDE_INT len
11704 = native_encode_expr (arg0, b, bitsize / BITS_PER_UNIT,
11705 bitpos / BITS_PER_UNIT);
11706 if (len > 0
11707 && len * BITS_PER_UNIT >= bitsize)
11709 tree v = native_interpret_expr (type, b,
11710 bitsize / BITS_PER_UNIT);
11711 if (v)
11712 return v;
11717 return NULL_TREE;
11719 case FMA_EXPR:
11720 /* For integers we can decompose the FMA if possible. */
11721 if (TREE_CODE (arg0) == INTEGER_CST
11722 && TREE_CODE (arg1) == INTEGER_CST)
11723 return fold_build2_loc (loc, PLUS_EXPR, type,
11724 const_binop (MULT_EXPR, arg0, arg1), arg2);
11725 if (integer_zerop (arg2))
11726 return fold_build2_loc (loc, MULT_EXPR, type, arg0, arg1);
11728 return fold_fma (loc, type, arg0, arg1, arg2);
11730 case VEC_PERM_EXPR:
11731 if (TREE_CODE (arg2) == VECTOR_CST)
11733 /* Build a vector of integers from the tree mask. */
11734 vec_perm_builder builder;
11735 if (!tree_to_vec_perm_builder (&builder, arg2))
11736 return NULL_TREE;
11738 /* Create a vec_perm_indices for the integer vector. */
11739 poly_uint64 nelts = TYPE_VECTOR_SUBPARTS (type);
11740 bool single_arg = (op0 == op1);
11741 vec_perm_indices sel (builder, single_arg ? 1 : 2, nelts);
11743 /* Check for cases that fold to OP0 or OP1 in their original
11744 element order. */
11745 if (sel.series_p (0, 1, 0, 1))
11746 return op0;
11747 if (sel.series_p (0, 1, nelts, 1))
11748 return op1;
11750 if (!single_arg)
11752 if (sel.all_from_input_p (0))
11753 op1 = op0;
11754 else if (sel.all_from_input_p (1))
11756 op0 = op1;
11757 sel.rotate_inputs (1);
11761 if ((TREE_CODE (op0) == VECTOR_CST
11762 || TREE_CODE (op0) == CONSTRUCTOR)
11763 && (TREE_CODE (op1) == VECTOR_CST
11764 || TREE_CODE (op1) == CONSTRUCTOR))
11766 tree t = fold_vec_perm (type, op0, op1, sel);
11767 if (t != NULL_TREE)
11768 return t;
11771 bool changed = (op0 == op1 && !single_arg);
11773 /* Generate a canonical form of the selector. */
11774 if (arg2 == op2 && sel.encoding () != builder)
11776 /* Some targets are deficient and fail to expand a single
11777 argument permutation while still allowing an equivalent
11778 2-argument version. */
11779 if (sel.ninputs () == 2
11780 || can_vec_perm_const_p (TYPE_MODE (type), sel, false))
11781 op2 = vec_perm_indices_to_tree (TREE_TYPE (arg2), sel);
11782 else
11784 vec_perm_indices sel2 (builder, 2, nelts);
11785 if (can_vec_perm_const_p (TYPE_MODE (type), sel2, false))
11786 op2 = vec_perm_indices_to_tree (TREE_TYPE (arg2), sel2);
11787 else
11788 /* Not directly supported with either encoding,
11789 so use the preferred form. */
11790 op2 = vec_perm_indices_to_tree (TREE_TYPE (arg2), sel);
11792 changed = true;
11795 if (changed)
11796 return build3_loc (loc, VEC_PERM_EXPR, type, op0, op1, op2);
11798 return NULL_TREE;
11800 case BIT_INSERT_EXPR:
11801 /* Perform (partial) constant folding of BIT_INSERT_EXPR. */
11802 if (TREE_CODE (arg0) == INTEGER_CST
11803 && TREE_CODE (arg1) == INTEGER_CST)
11805 unsigned HOST_WIDE_INT bitpos = tree_to_uhwi (op2);
11806 unsigned bitsize = TYPE_PRECISION (TREE_TYPE (arg1));
11807 wide_int tem = (wi::to_wide (arg0)
11808 & wi::shifted_mask (bitpos, bitsize, true,
11809 TYPE_PRECISION (type)));
11810 wide_int tem2
11811 = wi::lshift (wi::zext (wi::to_wide (arg1, TYPE_PRECISION (type)),
11812 bitsize), bitpos);
11813 return wide_int_to_tree (type, wi::bit_or (tem, tem2));
11815 else if (TREE_CODE (arg0) == VECTOR_CST
11816 && CONSTANT_CLASS_P (arg1)
11817 && types_compatible_p (TREE_TYPE (TREE_TYPE (arg0)),
11818 TREE_TYPE (arg1)))
11820 unsigned HOST_WIDE_INT bitpos = tree_to_uhwi (op2);
11821 unsigned HOST_WIDE_INT elsize
11822 = tree_to_uhwi (TYPE_SIZE (TREE_TYPE (arg1)));
11823 if (bitpos % elsize == 0)
11825 unsigned k = bitpos / elsize;
11826 unsigned HOST_WIDE_INT nelts;
11827 if (operand_equal_p (VECTOR_CST_ELT (arg0, k), arg1, 0))
11828 return arg0;
11829 else if (VECTOR_CST_NELTS (arg0).is_constant (&nelts))
11831 tree_vector_builder elts (type, nelts, 1);
11832 elts.quick_grow (nelts);
11833 for (unsigned HOST_WIDE_INT i = 0; i < nelts; ++i)
11834 elts[i] = (i == k ? arg1 : VECTOR_CST_ELT (arg0, i));
11835 return elts.build ();
11839 return NULL_TREE;
11841 default:
11842 return NULL_TREE;
11843 } /* switch (code) */
11846 /* Gets the element ACCESS_INDEX from CTOR, which must be a CONSTRUCTOR
11847 of an array (or vector). */
11849 tree
11850 get_array_ctor_element_at_index (tree ctor, offset_int access_index)
11852 tree index_type = NULL_TREE;
11853 offset_int low_bound = 0;
11855 if (TREE_CODE (TREE_TYPE (ctor)) == ARRAY_TYPE)
11857 tree domain_type = TYPE_DOMAIN (TREE_TYPE (ctor));
11858 if (domain_type && TYPE_MIN_VALUE (domain_type))
11860 /* Static constructors for variably sized objects makes no sense. */
11861 gcc_assert (TREE_CODE (TYPE_MIN_VALUE (domain_type)) == INTEGER_CST);
11862 index_type = TREE_TYPE (TYPE_MIN_VALUE (domain_type));
11863 low_bound = wi::to_offset (TYPE_MIN_VALUE (domain_type));
11867 if (index_type)
11868 access_index = wi::ext (access_index, TYPE_PRECISION (index_type),
11869 TYPE_SIGN (index_type));
11871 offset_int index = low_bound - 1;
11872 if (index_type)
11873 index = wi::ext (index, TYPE_PRECISION (index_type),
11874 TYPE_SIGN (index_type));
11876 offset_int max_index;
11877 unsigned HOST_WIDE_INT cnt;
11878 tree cfield, cval;
11880 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor), cnt, cfield, cval)
11882 /* Array constructor might explicitly set index, or specify a range,
11883 or leave index NULL meaning that it is next index after previous
11884 one. */
11885 if (cfield)
11887 if (TREE_CODE (cfield) == INTEGER_CST)
11888 max_index = index = wi::to_offset (cfield);
11889 else
11891 gcc_assert (TREE_CODE (cfield) == RANGE_EXPR);
11892 index = wi::to_offset (TREE_OPERAND (cfield, 0));
11893 max_index = wi::to_offset (TREE_OPERAND (cfield, 1));
11896 else
11898 index += 1;
11899 if (index_type)
11900 index = wi::ext (index, TYPE_PRECISION (index_type),
11901 TYPE_SIGN (index_type));
11902 max_index = index;
11905 /* Do we have match? */
11906 if (wi::cmpu (access_index, index) >= 0
11907 && wi::cmpu (access_index, max_index) <= 0)
11908 return cval;
11910 return NULL_TREE;
11913 /* Perform constant folding and related simplification of EXPR.
11914 The related simplifications include x*1 => x, x*0 => 0, etc.,
11915 and application of the associative law.
11916 NOP_EXPR conversions may be removed freely (as long as we
11917 are careful not to change the type of the overall expression).
11918 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
11919 but we can constant-fold them if they have constant operands. */
11921 #ifdef ENABLE_FOLD_CHECKING
11922 # define fold(x) fold_1 (x)
11923 static tree fold_1 (tree);
11924 static
11925 #endif
11926 tree
11927 fold (tree expr)
11929 const tree t = expr;
11930 enum tree_code code = TREE_CODE (t);
11931 enum tree_code_class kind = TREE_CODE_CLASS (code);
11932 tree tem;
11933 location_t loc = EXPR_LOCATION (expr);
11935 /* Return right away if a constant. */
11936 if (kind == tcc_constant)
11937 return t;
11939 /* CALL_EXPR-like objects with variable numbers of operands are
11940 treated specially. */
11941 if (kind == tcc_vl_exp)
11943 if (code == CALL_EXPR)
11945 tem = fold_call_expr (loc, expr, false);
11946 return tem ? tem : expr;
11948 return expr;
11951 if (IS_EXPR_CODE_CLASS (kind))
11953 tree type = TREE_TYPE (t);
11954 tree op0, op1, op2;
11956 switch (TREE_CODE_LENGTH (code))
11958 case 1:
11959 op0 = TREE_OPERAND (t, 0);
11960 tem = fold_unary_loc (loc, code, type, op0);
11961 return tem ? tem : expr;
11962 case 2:
11963 op0 = TREE_OPERAND (t, 0);
11964 op1 = TREE_OPERAND (t, 1);
11965 tem = fold_binary_loc (loc, code, type, op0, op1);
11966 return tem ? tem : expr;
11967 case 3:
11968 op0 = TREE_OPERAND (t, 0);
11969 op1 = TREE_OPERAND (t, 1);
11970 op2 = TREE_OPERAND (t, 2);
11971 tem = fold_ternary_loc (loc, code, type, op0, op1, op2);
11972 return tem ? tem : expr;
11973 default:
11974 break;
11978 switch (code)
11980 case ARRAY_REF:
11982 tree op0 = TREE_OPERAND (t, 0);
11983 tree op1 = TREE_OPERAND (t, 1);
11985 if (TREE_CODE (op1) == INTEGER_CST
11986 && TREE_CODE (op0) == CONSTRUCTOR
11987 && ! type_contains_placeholder_p (TREE_TYPE (op0)))
11989 tree val = get_array_ctor_element_at_index (op0,
11990 wi::to_offset (op1));
11991 if (val)
11992 return val;
11995 return t;
11998 /* Return a VECTOR_CST if possible. */
11999 case CONSTRUCTOR:
12001 tree type = TREE_TYPE (t);
12002 if (TREE_CODE (type) != VECTOR_TYPE)
12003 return t;
12005 unsigned i;
12006 tree val;
12007 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (t), i, val)
12008 if (! CONSTANT_CLASS_P (val))
12009 return t;
12011 return build_vector_from_ctor (type, CONSTRUCTOR_ELTS (t));
12014 case CONST_DECL:
12015 return fold (DECL_INITIAL (t));
12017 default:
12018 return t;
12019 } /* switch (code) */
12022 #ifdef ENABLE_FOLD_CHECKING
12023 #undef fold
12025 static void fold_checksum_tree (const_tree, struct md5_ctx *,
12026 hash_table<nofree_ptr_hash<const tree_node> > *);
12027 static void fold_check_failed (const_tree, const_tree);
12028 void print_fold_checksum (const_tree);
12030 /* When --enable-checking=fold, compute a digest of expr before
12031 and after actual fold call to see if fold did not accidentally
12032 change original expr. */
12034 tree
12035 fold (tree expr)
12037 tree ret;
12038 struct md5_ctx ctx;
12039 unsigned char checksum_before[16], checksum_after[16];
12040 hash_table<nofree_ptr_hash<const tree_node> > ht (32);
12042 md5_init_ctx (&ctx);
12043 fold_checksum_tree (expr, &ctx, &ht);
12044 md5_finish_ctx (&ctx, checksum_before);
12045 ht.empty ();
12047 ret = fold_1 (expr);
12049 md5_init_ctx (&ctx);
12050 fold_checksum_tree (expr, &ctx, &ht);
12051 md5_finish_ctx (&ctx, checksum_after);
12053 if (memcmp (checksum_before, checksum_after, 16))
12054 fold_check_failed (expr, ret);
12056 return ret;
12059 void
12060 print_fold_checksum (const_tree expr)
12062 struct md5_ctx ctx;
12063 unsigned char checksum[16], cnt;
12064 hash_table<nofree_ptr_hash<const tree_node> > ht (32);
12066 md5_init_ctx (&ctx);
12067 fold_checksum_tree (expr, &ctx, &ht);
12068 md5_finish_ctx (&ctx, checksum);
12069 for (cnt = 0; cnt < 16; ++cnt)
12070 fprintf (stderr, "%02x", checksum[cnt]);
12071 putc ('\n', stderr);
12074 static void
12075 fold_check_failed (const_tree expr ATTRIBUTE_UNUSED, const_tree ret ATTRIBUTE_UNUSED)
12077 internal_error ("fold check: original tree changed by fold");
12080 static void
12081 fold_checksum_tree (const_tree expr, struct md5_ctx *ctx,
12082 hash_table<nofree_ptr_hash <const tree_node> > *ht)
12084 const tree_node **slot;
12085 enum tree_code code;
12086 union tree_node buf;
12087 int i, len;
12089 recursive_label:
12090 if (expr == NULL)
12091 return;
12092 slot = ht->find_slot (expr, INSERT);
12093 if (*slot != NULL)
12094 return;
12095 *slot = expr;
12096 code = TREE_CODE (expr);
12097 if (TREE_CODE_CLASS (code) == tcc_declaration
12098 && HAS_DECL_ASSEMBLER_NAME_P (expr))
12100 /* Allow DECL_ASSEMBLER_NAME and symtab_node to be modified. */
12101 memcpy ((char *) &buf, expr, tree_size (expr));
12102 SET_DECL_ASSEMBLER_NAME ((tree)&buf, NULL);
12103 buf.decl_with_vis.symtab_node = NULL;
12104 expr = (tree) &buf;
12106 else if (TREE_CODE_CLASS (code) == tcc_type
12107 && (TYPE_POINTER_TO (expr)
12108 || TYPE_REFERENCE_TO (expr)
12109 || TYPE_CACHED_VALUES_P (expr)
12110 || TYPE_CONTAINS_PLACEHOLDER_INTERNAL (expr)
12111 || TYPE_NEXT_VARIANT (expr)
12112 || TYPE_ALIAS_SET_KNOWN_P (expr)))
12114 /* Allow these fields to be modified. */
12115 tree tmp;
12116 memcpy ((char *) &buf, expr, tree_size (expr));
12117 expr = tmp = (tree) &buf;
12118 TYPE_CONTAINS_PLACEHOLDER_INTERNAL (tmp) = 0;
12119 TYPE_POINTER_TO (tmp) = NULL;
12120 TYPE_REFERENCE_TO (tmp) = NULL;
12121 TYPE_NEXT_VARIANT (tmp) = NULL;
12122 TYPE_ALIAS_SET (tmp) = -1;
12123 if (TYPE_CACHED_VALUES_P (tmp))
12125 TYPE_CACHED_VALUES_P (tmp) = 0;
12126 TYPE_CACHED_VALUES (tmp) = NULL;
12129 md5_process_bytes (expr, tree_size (expr), ctx);
12130 if (CODE_CONTAINS_STRUCT (code, TS_TYPED))
12131 fold_checksum_tree (TREE_TYPE (expr), ctx, ht);
12132 if (TREE_CODE_CLASS (code) != tcc_type
12133 && TREE_CODE_CLASS (code) != tcc_declaration
12134 && code != TREE_LIST
12135 && code != SSA_NAME
12136 && CODE_CONTAINS_STRUCT (code, TS_COMMON))
12137 fold_checksum_tree (TREE_CHAIN (expr), ctx, ht);
12138 switch (TREE_CODE_CLASS (code))
12140 case tcc_constant:
12141 switch (code)
12143 case STRING_CST:
12144 md5_process_bytes (TREE_STRING_POINTER (expr),
12145 TREE_STRING_LENGTH (expr), ctx);
12146 break;
12147 case COMPLEX_CST:
12148 fold_checksum_tree (TREE_REALPART (expr), ctx, ht);
12149 fold_checksum_tree (TREE_IMAGPART (expr), ctx, ht);
12150 break;
12151 case VECTOR_CST:
12152 len = vector_cst_encoded_nelts (expr);
12153 for (i = 0; i < len; ++i)
12154 fold_checksum_tree (VECTOR_CST_ENCODED_ELT (expr, i), ctx, ht);
12155 break;
12156 default:
12157 break;
12159 break;
12160 case tcc_exceptional:
12161 switch (code)
12163 case TREE_LIST:
12164 fold_checksum_tree (TREE_PURPOSE (expr), ctx, ht);
12165 fold_checksum_tree (TREE_VALUE (expr), ctx, ht);
12166 expr = TREE_CHAIN (expr);
12167 goto recursive_label;
12168 break;
12169 case TREE_VEC:
12170 for (i = 0; i < TREE_VEC_LENGTH (expr); ++i)
12171 fold_checksum_tree (TREE_VEC_ELT (expr, i), ctx, ht);
12172 break;
12173 default:
12174 break;
12176 break;
12177 case tcc_expression:
12178 case tcc_reference:
12179 case tcc_comparison:
12180 case tcc_unary:
12181 case tcc_binary:
12182 case tcc_statement:
12183 case tcc_vl_exp:
12184 len = TREE_OPERAND_LENGTH (expr);
12185 for (i = 0; i < len; ++i)
12186 fold_checksum_tree (TREE_OPERAND (expr, i), ctx, ht);
12187 break;
12188 case tcc_declaration:
12189 fold_checksum_tree (DECL_NAME (expr), ctx, ht);
12190 fold_checksum_tree (DECL_CONTEXT (expr), ctx, ht);
12191 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_COMMON))
12193 fold_checksum_tree (DECL_SIZE (expr), ctx, ht);
12194 fold_checksum_tree (DECL_SIZE_UNIT (expr), ctx, ht);
12195 fold_checksum_tree (DECL_INITIAL (expr), ctx, ht);
12196 fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr), ctx, ht);
12197 fold_checksum_tree (DECL_ATTRIBUTES (expr), ctx, ht);
12200 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_NON_COMMON))
12202 if (TREE_CODE (expr) == FUNCTION_DECL)
12204 fold_checksum_tree (DECL_VINDEX (expr), ctx, ht);
12205 fold_checksum_tree (DECL_ARGUMENTS (expr), ctx, ht);
12207 fold_checksum_tree (DECL_RESULT_FLD (expr), ctx, ht);
12209 break;
12210 case tcc_type:
12211 if (TREE_CODE (expr) == ENUMERAL_TYPE)
12212 fold_checksum_tree (TYPE_VALUES (expr), ctx, ht);
12213 fold_checksum_tree (TYPE_SIZE (expr), ctx, ht);
12214 fold_checksum_tree (TYPE_SIZE_UNIT (expr), ctx, ht);
12215 fold_checksum_tree (TYPE_ATTRIBUTES (expr), ctx, ht);
12216 fold_checksum_tree (TYPE_NAME (expr), ctx, ht);
12217 if (INTEGRAL_TYPE_P (expr)
12218 || SCALAR_FLOAT_TYPE_P (expr))
12220 fold_checksum_tree (TYPE_MIN_VALUE (expr), ctx, ht);
12221 fold_checksum_tree (TYPE_MAX_VALUE (expr), ctx, ht);
12223 fold_checksum_tree (TYPE_MAIN_VARIANT (expr), ctx, ht);
12224 if (TREE_CODE (expr) == RECORD_TYPE
12225 || TREE_CODE (expr) == UNION_TYPE
12226 || TREE_CODE (expr) == QUAL_UNION_TYPE)
12227 fold_checksum_tree (TYPE_BINFO (expr), ctx, ht);
12228 fold_checksum_tree (TYPE_CONTEXT (expr), ctx, ht);
12229 break;
12230 default:
12231 break;
12235 /* Helper function for outputting the checksum of a tree T. When
12236 debugging with gdb, you can "define mynext" to be "next" followed
12237 by "call debug_fold_checksum (op0)", then just trace down till the
12238 outputs differ. */
12240 DEBUG_FUNCTION void
12241 debug_fold_checksum (const_tree t)
12243 int i;
12244 unsigned char checksum[16];
12245 struct md5_ctx ctx;
12246 hash_table<nofree_ptr_hash<const tree_node> > ht (32);
12248 md5_init_ctx (&ctx);
12249 fold_checksum_tree (t, &ctx, &ht);
12250 md5_finish_ctx (&ctx, checksum);
12251 ht.empty ();
12253 for (i = 0; i < 16; i++)
12254 fprintf (stderr, "%d ", checksum[i]);
12256 fprintf (stderr, "\n");
12259 #endif
12261 /* Fold a unary tree expression with code CODE of type TYPE with an
12262 operand OP0. LOC is the location of the resulting expression.
12263 Return a folded expression if successful. Otherwise, return a tree
12264 expression with code CODE of type TYPE with an operand OP0. */
12266 tree
12267 fold_build1_loc (location_t loc,
12268 enum tree_code code, tree type, tree op0 MEM_STAT_DECL)
12270 tree tem;
12271 #ifdef ENABLE_FOLD_CHECKING
12272 unsigned char checksum_before[16], checksum_after[16];
12273 struct md5_ctx ctx;
12274 hash_table<nofree_ptr_hash<const tree_node> > ht (32);
12276 md5_init_ctx (&ctx);
12277 fold_checksum_tree (op0, &ctx, &ht);
12278 md5_finish_ctx (&ctx, checksum_before);
12279 ht.empty ();
12280 #endif
12282 tem = fold_unary_loc (loc, code, type, op0);
12283 if (!tem)
12284 tem = build1_loc (loc, code, type, op0 PASS_MEM_STAT);
12286 #ifdef ENABLE_FOLD_CHECKING
12287 md5_init_ctx (&ctx);
12288 fold_checksum_tree (op0, &ctx, &ht);
12289 md5_finish_ctx (&ctx, checksum_after);
12291 if (memcmp (checksum_before, checksum_after, 16))
12292 fold_check_failed (op0, tem);
12293 #endif
12294 return tem;
12297 /* Fold a binary tree expression with code CODE of type TYPE with
12298 operands OP0 and OP1. LOC is the location of the resulting
12299 expression. Return a folded expression if successful. Otherwise,
12300 return a tree expression with code CODE of type TYPE with operands
12301 OP0 and OP1. */
12303 tree
12304 fold_build2_loc (location_t loc,
12305 enum tree_code code, tree type, tree op0, tree op1
12306 MEM_STAT_DECL)
12308 tree tem;
12309 #ifdef ENABLE_FOLD_CHECKING
12310 unsigned char checksum_before_op0[16],
12311 checksum_before_op1[16],
12312 checksum_after_op0[16],
12313 checksum_after_op1[16];
12314 struct md5_ctx ctx;
12315 hash_table<nofree_ptr_hash<const tree_node> > ht (32);
12317 md5_init_ctx (&ctx);
12318 fold_checksum_tree (op0, &ctx, &ht);
12319 md5_finish_ctx (&ctx, checksum_before_op0);
12320 ht.empty ();
12322 md5_init_ctx (&ctx);
12323 fold_checksum_tree (op1, &ctx, &ht);
12324 md5_finish_ctx (&ctx, checksum_before_op1);
12325 ht.empty ();
12326 #endif
12328 tem = fold_binary_loc (loc, code, type, op0, op1);
12329 if (!tem)
12330 tem = build2_loc (loc, code, type, op0, op1 PASS_MEM_STAT);
12332 #ifdef ENABLE_FOLD_CHECKING
12333 md5_init_ctx (&ctx);
12334 fold_checksum_tree (op0, &ctx, &ht);
12335 md5_finish_ctx (&ctx, checksum_after_op0);
12336 ht.empty ();
12338 if (memcmp (checksum_before_op0, checksum_after_op0, 16))
12339 fold_check_failed (op0, tem);
12341 md5_init_ctx (&ctx);
12342 fold_checksum_tree (op1, &ctx, &ht);
12343 md5_finish_ctx (&ctx, checksum_after_op1);
12345 if (memcmp (checksum_before_op1, checksum_after_op1, 16))
12346 fold_check_failed (op1, tem);
12347 #endif
12348 return tem;
12351 /* Fold a ternary tree expression with code CODE of type TYPE with
12352 operands OP0, OP1, and OP2. Return a folded expression if
12353 successful. Otherwise, return a tree expression with code CODE of
12354 type TYPE with operands OP0, OP1, and OP2. */
12356 tree
12357 fold_build3_loc (location_t loc, enum tree_code code, tree type,
12358 tree op0, tree op1, tree op2 MEM_STAT_DECL)
12360 tree tem;
12361 #ifdef ENABLE_FOLD_CHECKING
12362 unsigned char checksum_before_op0[16],
12363 checksum_before_op1[16],
12364 checksum_before_op2[16],
12365 checksum_after_op0[16],
12366 checksum_after_op1[16],
12367 checksum_after_op2[16];
12368 struct md5_ctx ctx;
12369 hash_table<nofree_ptr_hash<const tree_node> > ht (32);
12371 md5_init_ctx (&ctx);
12372 fold_checksum_tree (op0, &ctx, &ht);
12373 md5_finish_ctx (&ctx, checksum_before_op0);
12374 ht.empty ();
12376 md5_init_ctx (&ctx);
12377 fold_checksum_tree (op1, &ctx, &ht);
12378 md5_finish_ctx (&ctx, checksum_before_op1);
12379 ht.empty ();
12381 md5_init_ctx (&ctx);
12382 fold_checksum_tree (op2, &ctx, &ht);
12383 md5_finish_ctx (&ctx, checksum_before_op2);
12384 ht.empty ();
12385 #endif
12387 gcc_assert (TREE_CODE_CLASS (code) != tcc_vl_exp);
12388 tem = fold_ternary_loc (loc, code, type, op0, op1, op2);
12389 if (!tem)
12390 tem = build3_loc (loc, code, type, op0, op1, op2 PASS_MEM_STAT);
12392 #ifdef ENABLE_FOLD_CHECKING
12393 md5_init_ctx (&ctx);
12394 fold_checksum_tree (op0, &ctx, &ht);
12395 md5_finish_ctx (&ctx, checksum_after_op0);
12396 ht.empty ();
12398 if (memcmp (checksum_before_op0, checksum_after_op0, 16))
12399 fold_check_failed (op0, tem);
12401 md5_init_ctx (&ctx);
12402 fold_checksum_tree (op1, &ctx, &ht);
12403 md5_finish_ctx (&ctx, checksum_after_op1);
12404 ht.empty ();
12406 if (memcmp (checksum_before_op1, checksum_after_op1, 16))
12407 fold_check_failed (op1, tem);
12409 md5_init_ctx (&ctx);
12410 fold_checksum_tree (op2, &ctx, &ht);
12411 md5_finish_ctx (&ctx, checksum_after_op2);
12413 if (memcmp (checksum_before_op2, checksum_after_op2, 16))
12414 fold_check_failed (op2, tem);
12415 #endif
12416 return tem;
12419 /* Fold a CALL_EXPR expression of type TYPE with operands FN and NARGS
12420 arguments in ARGARRAY, and a null static chain.
12421 Return a folded expression if successful. Otherwise, return a CALL_EXPR
12422 of type TYPE from the given operands as constructed by build_call_array. */
12424 tree
12425 fold_build_call_array_loc (location_t loc, tree type, tree fn,
12426 int nargs, tree *argarray)
12428 tree tem;
12429 #ifdef ENABLE_FOLD_CHECKING
12430 unsigned char checksum_before_fn[16],
12431 checksum_before_arglist[16],
12432 checksum_after_fn[16],
12433 checksum_after_arglist[16];
12434 struct md5_ctx ctx;
12435 hash_table<nofree_ptr_hash<const tree_node> > ht (32);
12436 int i;
12438 md5_init_ctx (&ctx);
12439 fold_checksum_tree (fn, &ctx, &ht);
12440 md5_finish_ctx (&ctx, checksum_before_fn);
12441 ht.empty ();
12443 md5_init_ctx (&ctx);
12444 for (i = 0; i < nargs; i++)
12445 fold_checksum_tree (argarray[i], &ctx, &ht);
12446 md5_finish_ctx (&ctx, checksum_before_arglist);
12447 ht.empty ();
12448 #endif
12450 tem = fold_builtin_call_array (loc, type, fn, nargs, argarray);
12451 if (!tem)
12452 tem = build_call_array_loc (loc, type, fn, nargs, argarray);
12454 #ifdef ENABLE_FOLD_CHECKING
12455 md5_init_ctx (&ctx);
12456 fold_checksum_tree (fn, &ctx, &ht);
12457 md5_finish_ctx (&ctx, checksum_after_fn);
12458 ht.empty ();
12460 if (memcmp (checksum_before_fn, checksum_after_fn, 16))
12461 fold_check_failed (fn, tem);
12463 md5_init_ctx (&ctx);
12464 for (i = 0; i < nargs; i++)
12465 fold_checksum_tree (argarray[i], &ctx, &ht);
12466 md5_finish_ctx (&ctx, checksum_after_arglist);
12468 if (memcmp (checksum_before_arglist, checksum_after_arglist, 16))
12469 fold_check_failed (NULL_TREE, tem);
12470 #endif
12471 return tem;
12474 /* Perform constant folding and related simplification of initializer
12475 expression EXPR. These behave identically to "fold_buildN" but ignore
12476 potential run-time traps and exceptions that fold must preserve. */
12478 #define START_FOLD_INIT \
12479 int saved_signaling_nans = flag_signaling_nans;\
12480 int saved_trapping_math = flag_trapping_math;\
12481 int saved_rounding_math = flag_rounding_math;\
12482 int saved_trapv = flag_trapv;\
12483 int saved_folding_initializer = folding_initializer;\
12484 flag_signaling_nans = 0;\
12485 flag_trapping_math = 0;\
12486 flag_rounding_math = 0;\
12487 flag_trapv = 0;\
12488 folding_initializer = 1;
12490 #define END_FOLD_INIT \
12491 flag_signaling_nans = saved_signaling_nans;\
12492 flag_trapping_math = saved_trapping_math;\
12493 flag_rounding_math = saved_rounding_math;\
12494 flag_trapv = saved_trapv;\
12495 folding_initializer = saved_folding_initializer;
12497 tree
12498 fold_build1_initializer_loc (location_t loc, enum tree_code code,
12499 tree type, tree op)
12501 tree result;
12502 START_FOLD_INIT;
12504 result = fold_build1_loc (loc, code, type, op);
12506 END_FOLD_INIT;
12507 return result;
12510 tree
12511 fold_build2_initializer_loc (location_t loc, enum tree_code code,
12512 tree type, tree op0, tree op1)
12514 tree result;
12515 START_FOLD_INIT;
12517 result = fold_build2_loc (loc, code, type, op0, op1);
12519 END_FOLD_INIT;
12520 return result;
12523 tree
12524 fold_build_call_array_initializer_loc (location_t loc, tree type, tree fn,
12525 int nargs, tree *argarray)
12527 tree result;
12528 START_FOLD_INIT;
12530 result = fold_build_call_array_loc (loc, type, fn, nargs, argarray);
12532 END_FOLD_INIT;
12533 return result;
12536 #undef START_FOLD_INIT
12537 #undef END_FOLD_INIT
12539 /* Determine if first argument is a multiple of second argument. Return 0 if
12540 it is not, or we cannot easily determined it to be.
12542 An example of the sort of thing we care about (at this point; this routine
12543 could surely be made more general, and expanded to do what the *_DIV_EXPR's
12544 fold cases do now) is discovering that
12546 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
12548 is a multiple of
12550 SAVE_EXPR (J * 8)
12552 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
12554 This code also handles discovering that
12556 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
12558 is a multiple of 8 so we don't have to worry about dealing with a
12559 possible remainder.
12561 Note that we *look* inside a SAVE_EXPR only to determine how it was
12562 calculated; it is not safe for fold to do much of anything else with the
12563 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
12564 at run time. For example, the latter example above *cannot* be implemented
12565 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
12566 evaluation time of the original SAVE_EXPR is not necessarily the same at
12567 the time the new expression is evaluated. The only optimization of this
12568 sort that would be valid is changing
12570 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
12572 divided by 8 to
12574 SAVE_EXPR (I) * SAVE_EXPR (J)
12576 (where the same SAVE_EXPR (J) is used in the original and the
12577 transformed version). */
12580 multiple_of_p (tree type, const_tree top, const_tree bottom)
12582 gimple *stmt;
12583 tree t1, op1, op2;
12585 if (operand_equal_p (top, bottom, 0))
12586 return 1;
12588 if (TREE_CODE (type) != INTEGER_TYPE)
12589 return 0;
12591 switch (TREE_CODE (top))
12593 case BIT_AND_EXPR:
12594 /* Bitwise and provides a power of two multiple. If the mask is
12595 a multiple of BOTTOM then TOP is a multiple of BOTTOM. */
12596 if (!integer_pow2p (bottom))
12597 return 0;
12598 return (multiple_of_p (type, TREE_OPERAND (top, 1), bottom)
12599 || multiple_of_p (type, TREE_OPERAND (top, 0), bottom));
12601 case MULT_EXPR:
12602 if (TREE_CODE (bottom) == INTEGER_CST)
12604 op1 = TREE_OPERAND (top, 0);
12605 op2 = TREE_OPERAND (top, 1);
12606 if (TREE_CODE (op1) == INTEGER_CST)
12607 std::swap (op1, op2);
12608 if (TREE_CODE (op2) == INTEGER_CST)
12610 if (multiple_of_p (type, op2, bottom))
12611 return 1;
12612 /* Handle multiple_of_p ((x * 2 + 2) * 4, 8). */
12613 if (multiple_of_p (type, bottom, op2))
12615 widest_int w = wi::sdiv_trunc (wi::to_widest (bottom),
12616 wi::to_widest (op2));
12617 if (wi::fits_to_tree_p (w, TREE_TYPE (bottom)))
12619 op2 = wide_int_to_tree (TREE_TYPE (bottom), w);
12620 return multiple_of_p (type, op1, op2);
12623 return multiple_of_p (type, op1, bottom);
12626 return (multiple_of_p (type, TREE_OPERAND (top, 1), bottom)
12627 || multiple_of_p (type, TREE_OPERAND (top, 0), bottom));
12629 case MINUS_EXPR:
12630 /* It is impossible to prove if op0 - op1 is multiple of bottom
12631 precisely, so be conservative here checking if both op0 and op1
12632 are multiple of bottom. Note we check the second operand first
12633 since it's usually simpler. */
12634 return (multiple_of_p (type, TREE_OPERAND (top, 1), bottom)
12635 && multiple_of_p (type, TREE_OPERAND (top, 0), bottom));
12637 case PLUS_EXPR:
12638 /* The same as MINUS_EXPR, but handle cases like op0 + 0xfffffffd
12639 as op0 - 3 if the expression has unsigned type. For example,
12640 (X / 3) + 0xfffffffd is multiple of 3, but 0xfffffffd is not. */
12641 op1 = TREE_OPERAND (top, 1);
12642 if (TYPE_UNSIGNED (type)
12643 && TREE_CODE (op1) == INTEGER_CST && tree_int_cst_sign_bit (op1))
12644 op1 = fold_build1 (NEGATE_EXPR, type, op1);
12645 return (multiple_of_p (type, op1, bottom)
12646 && multiple_of_p (type, TREE_OPERAND (top, 0), bottom));
12648 case LSHIFT_EXPR:
12649 if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
12651 op1 = TREE_OPERAND (top, 1);
12652 /* const_binop may not detect overflow correctly,
12653 so check for it explicitly here. */
12654 if (wi::gtu_p (TYPE_PRECISION (TREE_TYPE (size_one_node)),
12655 wi::to_wide (op1))
12656 && (t1 = fold_convert (type,
12657 const_binop (LSHIFT_EXPR, size_one_node,
12658 op1))) != 0
12659 && !TREE_OVERFLOW (t1))
12660 return multiple_of_p (type, t1, bottom);
12662 return 0;
12664 case NOP_EXPR:
12665 /* Can't handle conversions from non-integral or wider integral type. */
12666 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
12667 || (TYPE_PRECISION (type)
12668 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
12669 return 0;
12671 /* fall through */
12673 case SAVE_EXPR:
12674 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
12676 case COND_EXPR:
12677 return (multiple_of_p (type, TREE_OPERAND (top, 1), bottom)
12678 && multiple_of_p (type, TREE_OPERAND (top, 2), bottom));
12680 case INTEGER_CST:
12681 if (TREE_CODE (bottom) != INTEGER_CST
12682 || integer_zerop (bottom)
12683 || (TYPE_UNSIGNED (type)
12684 && (tree_int_cst_sgn (top) < 0
12685 || tree_int_cst_sgn (bottom) < 0)))
12686 return 0;
12687 return wi::multiple_of_p (wi::to_widest (top), wi::to_widest (bottom),
12688 SIGNED);
12690 case SSA_NAME:
12691 if (TREE_CODE (bottom) == INTEGER_CST
12692 && (stmt = SSA_NAME_DEF_STMT (top)) != NULL
12693 && gimple_code (stmt) == GIMPLE_ASSIGN)
12695 enum tree_code code = gimple_assign_rhs_code (stmt);
12697 /* Check for special cases to see if top is defined as multiple
12698 of bottom:
12700 top = (X & ~(bottom - 1) ; bottom is power of 2
12704 Y = X % bottom
12705 top = X - Y. */
12706 if (code == BIT_AND_EXPR
12707 && (op2 = gimple_assign_rhs2 (stmt)) != NULL_TREE
12708 && TREE_CODE (op2) == INTEGER_CST
12709 && integer_pow2p (bottom)
12710 && wi::multiple_of_p (wi::to_widest (op2),
12711 wi::to_widest (bottom), UNSIGNED))
12712 return 1;
12714 op1 = gimple_assign_rhs1 (stmt);
12715 if (code == MINUS_EXPR
12716 && (op2 = gimple_assign_rhs2 (stmt)) != NULL_TREE
12717 && TREE_CODE (op2) == SSA_NAME
12718 && (stmt = SSA_NAME_DEF_STMT (op2)) != NULL
12719 && gimple_code (stmt) == GIMPLE_ASSIGN
12720 && (code = gimple_assign_rhs_code (stmt)) == TRUNC_MOD_EXPR
12721 && operand_equal_p (op1, gimple_assign_rhs1 (stmt), 0)
12722 && operand_equal_p (bottom, gimple_assign_rhs2 (stmt), 0))
12723 return 1;
12726 /* fall through */
12728 default:
12729 if (POLY_INT_CST_P (top) && poly_int_tree_p (bottom))
12730 return multiple_p (wi::to_poly_widest (top),
12731 wi::to_poly_widest (bottom));
12733 return 0;
12737 #define tree_expr_nonnegative_warnv_p(X, Y) \
12738 _Pragma ("GCC error \"Use RECURSE for recursive calls\"") 0
12740 #define RECURSE(X) \
12741 ((tree_expr_nonnegative_warnv_p) (X, strict_overflow_p, depth + 1))
12743 /* Return true if CODE or TYPE is known to be non-negative. */
12745 static bool
12746 tree_simple_nonnegative_warnv_p (enum tree_code code, tree type)
12748 if ((TYPE_PRECISION (type) != 1 || TYPE_UNSIGNED (type))
12749 && truth_value_p (code))
12750 /* Truth values evaluate to 0 or 1, which is nonnegative unless we
12751 have a signed:1 type (where the value is -1 and 0). */
12752 return true;
12753 return false;
12756 /* Return true if (CODE OP0) is known to be non-negative. If the return
12757 value is based on the assumption that signed overflow is undefined,
12758 set *STRICT_OVERFLOW_P to true; otherwise, don't change
12759 *STRICT_OVERFLOW_P. DEPTH is the current nesting depth of the query. */
12761 bool
12762 tree_unary_nonnegative_warnv_p (enum tree_code code, tree type, tree op0,
12763 bool *strict_overflow_p, int depth)
12765 if (TYPE_UNSIGNED (type))
12766 return true;
12768 switch (code)
12770 case ABS_EXPR:
12771 /* We can't return 1 if flag_wrapv is set because
12772 ABS_EXPR<INT_MIN> = INT_MIN. */
12773 if (!ANY_INTEGRAL_TYPE_P (type))
12774 return true;
12775 if (TYPE_OVERFLOW_UNDEFINED (type))
12777 *strict_overflow_p = true;
12778 return true;
12780 break;
12782 case NON_LVALUE_EXPR:
12783 case FLOAT_EXPR:
12784 case FIX_TRUNC_EXPR:
12785 return RECURSE (op0);
12787 CASE_CONVERT:
12789 tree inner_type = TREE_TYPE (op0);
12790 tree outer_type = type;
12792 if (TREE_CODE (outer_type) == REAL_TYPE)
12794 if (TREE_CODE (inner_type) == REAL_TYPE)
12795 return RECURSE (op0);
12796 if (INTEGRAL_TYPE_P (inner_type))
12798 if (TYPE_UNSIGNED (inner_type))
12799 return true;
12800 return RECURSE (op0);
12803 else if (INTEGRAL_TYPE_P (outer_type))
12805 if (TREE_CODE (inner_type) == REAL_TYPE)
12806 return RECURSE (op0);
12807 if (INTEGRAL_TYPE_P (inner_type))
12808 return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
12809 && TYPE_UNSIGNED (inner_type);
12812 break;
12814 default:
12815 return tree_simple_nonnegative_warnv_p (code, type);
12818 /* We don't know sign of `t', so be conservative and return false. */
12819 return false;
12822 /* Return true if (CODE OP0 OP1) is known to be non-negative. If the return
12823 value is based on the assumption that signed overflow is undefined,
12824 set *STRICT_OVERFLOW_P to true; otherwise, don't change
12825 *STRICT_OVERFLOW_P. DEPTH is the current nesting depth of the query. */
12827 bool
12828 tree_binary_nonnegative_warnv_p (enum tree_code code, tree type, tree op0,
12829 tree op1, bool *strict_overflow_p,
12830 int depth)
12832 if (TYPE_UNSIGNED (type))
12833 return true;
12835 switch (code)
12837 case POINTER_PLUS_EXPR:
12838 case PLUS_EXPR:
12839 if (FLOAT_TYPE_P (type))
12840 return RECURSE (op0) && RECURSE (op1);
12842 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
12843 both unsigned and at least 2 bits shorter than the result. */
12844 if (TREE_CODE (type) == INTEGER_TYPE
12845 && TREE_CODE (op0) == NOP_EXPR
12846 && TREE_CODE (op1) == NOP_EXPR)
12848 tree inner1 = TREE_TYPE (TREE_OPERAND (op0, 0));
12849 tree inner2 = TREE_TYPE (TREE_OPERAND (op1, 0));
12850 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
12851 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
12853 unsigned int prec = MAX (TYPE_PRECISION (inner1),
12854 TYPE_PRECISION (inner2)) + 1;
12855 return prec < TYPE_PRECISION (type);
12858 break;
12860 case MULT_EXPR:
12861 if (FLOAT_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
12863 /* x * x is always non-negative for floating point x
12864 or without overflow. */
12865 if (operand_equal_p (op0, op1, 0)
12866 || (RECURSE (op0) && RECURSE (op1)))
12868 if (ANY_INTEGRAL_TYPE_P (type)
12869 && TYPE_OVERFLOW_UNDEFINED (type))
12870 *strict_overflow_p = true;
12871 return true;
12875 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
12876 both unsigned and their total bits is shorter than the result. */
12877 if (TREE_CODE (type) == INTEGER_TYPE
12878 && (TREE_CODE (op0) == NOP_EXPR || TREE_CODE (op0) == INTEGER_CST)
12879 && (TREE_CODE (op1) == NOP_EXPR || TREE_CODE (op1) == INTEGER_CST))
12881 tree inner0 = (TREE_CODE (op0) == NOP_EXPR)
12882 ? TREE_TYPE (TREE_OPERAND (op0, 0))
12883 : TREE_TYPE (op0);
12884 tree inner1 = (TREE_CODE (op1) == NOP_EXPR)
12885 ? TREE_TYPE (TREE_OPERAND (op1, 0))
12886 : TREE_TYPE (op1);
12888 bool unsigned0 = TYPE_UNSIGNED (inner0);
12889 bool unsigned1 = TYPE_UNSIGNED (inner1);
12891 if (TREE_CODE (op0) == INTEGER_CST)
12892 unsigned0 = unsigned0 || tree_int_cst_sgn (op0) >= 0;
12894 if (TREE_CODE (op1) == INTEGER_CST)
12895 unsigned1 = unsigned1 || tree_int_cst_sgn (op1) >= 0;
12897 if (TREE_CODE (inner0) == INTEGER_TYPE && unsigned0
12898 && TREE_CODE (inner1) == INTEGER_TYPE && unsigned1)
12900 unsigned int precision0 = (TREE_CODE (op0) == INTEGER_CST)
12901 ? tree_int_cst_min_precision (op0, UNSIGNED)
12902 : TYPE_PRECISION (inner0);
12904 unsigned int precision1 = (TREE_CODE (op1) == INTEGER_CST)
12905 ? tree_int_cst_min_precision (op1, UNSIGNED)
12906 : TYPE_PRECISION (inner1);
12908 return precision0 + precision1 < TYPE_PRECISION (type);
12911 return false;
12913 case BIT_AND_EXPR:
12914 case MAX_EXPR:
12915 return RECURSE (op0) || RECURSE (op1);
12917 case BIT_IOR_EXPR:
12918 case BIT_XOR_EXPR:
12919 case MIN_EXPR:
12920 case RDIV_EXPR:
12921 case TRUNC_DIV_EXPR:
12922 case CEIL_DIV_EXPR:
12923 case FLOOR_DIV_EXPR:
12924 case ROUND_DIV_EXPR:
12925 return RECURSE (op0) && RECURSE (op1);
12927 case TRUNC_MOD_EXPR:
12928 return RECURSE (op0);
12930 case FLOOR_MOD_EXPR:
12931 return RECURSE (op1);
12933 case CEIL_MOD_EXPR:
12934 case ROUND_MOD_EXPR:
12935 default:
12936 return tree_simple_nonnegative_warnv_p (code, type);
12939 /* We don't know sign of `t', so be conservative and return false. */
12940 return false;
12943 /* Return true if T is known to be non-negative. If the return
12944 value is based on the assumption that signed overflow is undefined,
12945 set *STRICT_OVERFLOW_P to true; otherwise, don't change
12946 *STRICT_OVERFLOW_P. DEPTH is the current nesting depth of the query. */
12948 bool
12949 tree_single_nonnegative_warnv_p (tree t, bool *strict_overflow_p, int depth)
12951 if (TYPE_UNSIGNED (TREE_TYPE (t)))
12952 return true;
12954 switch (TREE_CODE (t))
12956 case INTEGER_CST:
12957 return tree_int_cst_sgn (t) >= 0;
12959 case REAL_CST:
12960 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
12962 case FIXED_CST:
12963 return ! FIXED_VALUE_NEGATIVE (TREE_FIXED_CST (t));
12965 case COND_EXPR:
12966 return RECURSE (TREE_OPERAND (t, 1)) && RECURSE (TREE_OPERAND (t, 2));
12968 case SSA_NAME:
12969 /* Limit the depth of recursion to avoid quadratic behavior.
12970 This is expected to catch almost all occurrences in practice.
12971 If this code misses important cases that unbounded recursion
12972 would not, passes that need this information could be revised
12973 to provide it through dataflow propagation. */
12974 return (!name_registered_for_update_p (t)
12975 && depth < PARAM_VALUE (PARAM_MAX_SSA_NAME_QUERY_DEPTH)
12976 && gimple_stmt_nonnegative_warnv_p (SSA_NAME_DEF_STMT (t),
12977 strict_overflow_p, depth));
12979 default:
12980 return tree_simple_nonnegative_warnv_p (TREE_CODE (t), TREE_TYPE (t));
12984 /* Return true if T is known to be non-negative. If the return
12985 value is based on the assumption that signed overflow is undefined,
12986 set *STRICT_OVERFLOW_P to true; otherwise, don't change
12987 *STRICT_OVERFLOW_P. DEPTH is the current nesting depth of the query. */
12989 bool
12990 tree_call_nonnegative_warnv_p (tree type, combined_fn fn, tree arg0, tree arg1,
12991 bool *strict_overflow_p, int depth)
12993 switch (fn)
12995 CASE_CFN_ACOS:
12996 CASE_CFN_ACOSH:
12997 CASE_CFN_CABS:
12998 CASE_CFN_COSH:
12999 CASE_CFN_ERFC:
13000 CASE_CFN_EXP:
13001 CASE_CFN_EXP10:
13002 CASE_CFN_EXP2:
13003 CASE_CFN_FABS:
13004 CASE_CFN_FDIM:
13005 CASE_CFN_HYPOT:
13006 CASE_CFN_POW10:
13007 CASE_CFN_FFS:
13008 CASE_CFN_PARITY:
13009 CASE_CFN_POPCOUNT:
13010 CASE_CFN_CLZ:
13011 CASE_CFN_CLRSB:
13012 case CFN_BUILT_IN_BSWAP32:
13013 case CFN_BUILT_IN_BSWAP64:
13014 /* Always true. */
13015 return true;
13017 CASE_CFN_SQRT:
13018 CASE_CFN_SQRT_FN:
13019 /* sqrt(-0.0) is -0.0. */
13020 if (!HONOR_SIGNED_ZEROS (element_mode (type)))
13021 return true;
13022 return RECURSE (arg0);
13024 CASE_CFN_ASINH:
13025 CASE_CFN_ATAN:
13026 CASE_CFN_ATANH:
13027 CASE_CFN_CBRT:
13028 CASE_CFN_CEIL:
13029 CASE_CFN_CEIL_FN:
13030 CASE_CFN_ERF:
13031 CASE_CFN_EXPM1:
13032 CASE_CFN_FLOOR:
13033 CASE_CFN_FLOOR_FN:
13034 CASE_CFN_FMOD:
13035 CASE_CFN_FREXP:
13036 CASE_CFN_ICEIL:
13037 CASE_CFN_IFLOOR:
13038 CASE_CFN_IRINT:
13039 CASE_CFN_IROUND:
13040 CASE_CFN_LCEIL:
13041 CASE_CFN_LDEXP:
13042 CASE_CFN_LFLOOR:
13043 CASE_CFN_LLCEIL:
13044 CASE_CFN_LLFLOOR:
13045 CASE_CFN_LLRINT:
13046 CASE_CFN_LLROUND:
13047 CASE_CFN_LRINT:
13048 CASE_CFN_LROUND:
13049 CASE_CFN_MODF:
13050 CASE_CFN_NEARBYINT:
13051 CASE_CFN_NEARBYINT_FN:
13052 CASE_CFN_RINT:
13053 CASE_CFN_RINT_FN:
13054 CASE_CFN_ROUND:
13055 CASE_CFN_ROUND_FN:
13056 CASE_CFN_SCALB:
13057 CASE_CFN_SCALBLN:
13058 CASE_CFN_SCALBN:
13059 CASE_CFN_SIGNBIT:
13060 CASE_CFN_SIGNIFICAND:
13061 CASE_CFN_SINH:
13062 CASE_CFN_TANH:
13063 CASE_CFN_TRUNC:
13064 CASE_CFN_TRUNC_FN:
13065 /* True if the 1st argument is nonnegative. */
13066 return RECURSE (arg0);
13068 CASE_CFN_FMAX:
13069 CASE_CFN_FMAX_FN:
13070 /* True if the 1st OR 2nd arguments are nonnegative. */
13071 return RECURSE (arg0) || RECURSE (arg1);
13073 CASE_CFN_FMIN:
13074 CASE_CFN_FMIN_FN:
13075 /* True if the 1st AND 2nd arguments are nonnegative. */
13076 return RECURSE (arg0) && RECURSE (arg1);
13078 CASE_CFN_COPYSIGN:
13079 CASE_CFN_COPYSIGN_FN:
13080 /* True if the 2nd argument is nonnegative. */
13081 return RECURSE (arg1);
13083 CASE_CFN_POWI:
13084 /* True if the 1st argument is nonnegative or the second
13085 argument is an even integer. */
13086 if (TREE_CODE (arg1) == INTEGER_CST
13087 && (TREE_INT_CST_LOW (arg1) & 1) == 0)
13088 return true;
13089 return RECURSE (arg0);
13091 CASE_CFN_POW:
13092 /* True if the 1st argument is nonnegative or the second
13093 argument is an even integer valued real. */
13094 if (TREE_CODE (arg1) == REAL_CST)
13096 REAL_VALUE_TYPE c;
13097 HOST_WIDE_INT n;
13099 c = TREE_REAL_CST (arg1);
13100 n = real_to_integer (&c);
13101 if ((n & 1) == 0)
13103 REAL_VALUE_TYPE cint;
13104 real_from_integer (&cint, VOIDmode, n, SIGNED);
13105 if (real_identical (&c, &cint))
13106 return true;
13109 return RECURSE (arg0);
13111 default:
13112 break;
13114 return tree_simple_nonnegative_warnv_p (CALL_EXPR, type);
13117 /* Return true if T is known to be non-negative. If the return
13118 value is based on the assumption that signed overflow is undefined,
13119 set *STRICT_OVERFLOW_P to true; otherwise, don't change
13120 *STRICT_OVERFLOW_P. DEPTH is the current nesting depth of the query. */
13122 static bool
13123 tree_invalid_nonnegative_warnv_p (tree t, bool *strict_overflow_p, int depth)
13125 enum tree_code code = TREE_CODE (t);
13126 if (TYPE_UNSIGNED (TREE_TYPE (t)))
13127 return true;
13129 switch (code)
13131 case TARGET_EXPR:
13133 tree temp = TARGET_EXPR_SLOT (t);
13134 t = TARGET_EXPR_INITIAL (t);
13136 /* If the initializer is non-void, then it's a normal expression
13137 that will be assigned to the slot. */
13138 if (!VOID_TYPE_P (t))
13139 return RECURSE (t);
13141 /* Otherwise, the initializer sets the slot in some way. One common
13142 way is an assignment statement at the end of the initializer. */
13143 while (1)
13145 if (TREE_CODE (t) == BIND_EXPR)
13146 t = expr_last (BIND_EXPR_BODY (t));
13147 else if (TREE_CODE (t) == TRY_FINALLY_EXPR
13148 || TREE_CODE (t) == TRY_CATCH_EXPR)
13149 t = expr_last (TREE_OPERAND (t, 0));
13150 else if (TREE_CODE (t) == STATEMENT_LIST)
13151 t = expr_last (t);
13152 else
13153 break;
13155 if (TREE_CODE (t) == MODIFY_EXPR
13156 && TREE_OPERAND (t, 0) == temp)
13157 return RECURSE (TREE_OPERAND (t, 1));
13159 return false;
13162 case CALL_EXPR:
13164 tree arg0 = call_expr_nargs (t) > 0 ? CALL_EXPR_ARG (t, 0) : NULL_TREE;
13165 tree arg1 = call_expr_nargs (t) > 1 ? CALL_EXPR_ARG (t, 1) : NULL_TREE;
13167 return tree_call_nonnegative_warnv_p (TREE_TYPE (t),
13168 get_call_combined_fn (t),
13169 arg0,
13170 arg1,
13171 strict_overflow_p, depth);
13173 case COMPOUND_EXPR:
13174 case MODIFY_EXPR:
13175 return RECURSE (TREE_OPERAND (t, 1));
13177 case BIND_EXPR:
13178 return RECURSE (expr_last (TREE_OPERAND (t, 1)));
13180 case SAVE_EXPR:
13181 return RECURSE (TREE_OPERAND (t, 0));
13183 default:
13184 return tree_simple_nonnegative_warnv_p (TREE_CODE (t), TREE_TYPE (t));
13188 #undef RECURSE
13189 #undef tree_expr_nonnegative_warnv_p
13191 /* Return true if T is known to be non-negative. If the return
13192 value is based on the assumption that signed overflow is undefined,
13193 set *STRICT_OVERFLOW_P to true; otherwise, don't change
13194 *STRICT_OVERFLOW_P. DEPTH is the current nesting depth of the query. */
13196 bool
13197 tree_expr_nonnegative_warnv_p (tree t, bool *strict_overflow_p, int depth)
13199 enum tree_code code;
13200 if (t == error_mark_node)
13201 return false;
13203 code = TREE_CODE (t);
13204 switch (TREE_CODE_CLASS (code))
13206 case tcc_binary:
13207 case tcc_comparison:
13208 return tree_binary_nonnegative_warnv_p (TREE_CODE (t),
13209 TREE_TYPE (t),
13210 TREE_OPERAND (t, 0),
13211 TREE_OPERAND (t, 1),
13212 strict_overflow_p, depth);
13214 case tcc_unary:
13215 return tree_unary_nonnegative_warnv_p (TREE_CODE (t),
13216 TREE_TYPE (t),
13217 TREE_OPERAND (t, 0),
13218 strict_overflow_p, depth);
13220 case tcc_constant:
13221 case tcc_declaration:
13222 case tcc_reference:
13223 return tree_single_nonnegative_warnv_p (t, strict_overflow_p, depth);
13225 default:
13226 break;
13229 switch (code)
13231 case TRUTH_AND_EXPR:
13232 case TRUTH_OR_EXPR:
13233 case TRUTH_XOR_EXPR:
13234 return tree_binary_nonnegative_warnv_p (TREE_CODE (t),
13235 TREE_TYPE (t),
13236 TREE_OPERAND (t, 0),
13237 TREE_OPERAND (t, 1),
13238 strict_overflow_p, depth);
13239 case TRUTH_NOT_EXPR:
13240 return tree_unary_nonnegative_warnv_p (TREE_CODE (t),
13241 TREE_TYPE (t),
13242 TREE_OPERAND (t, 0),
13243 strict_overflow_p, depth);
13245 case COND_EXPR:
13246 case CONSTRUCTOR:
13247 case OBJ_TYPE_REF:
13248 case ASSERT_EXPR:
13249 case ADDR_EXPR:
13250 case WITH_SIZE_EXPR:
13251 case SSA_NAME:
13252 return tree_single_nonnegative_warnv_p (t, strict_overflow_p, depth);
13254 default:
13255 return tree_invalid_nonnegative_warnv_p (t, strict_overflow_p, depth);
13259 /* Return true if `t' is known to be non-negative. Handle warnings
13260 about undefined signed overflow. */
13262 bool
13263 tree_expr_nonnegative_p (tree t)
13265 bool ret, strict_overflow_p;
13267 strict_overflow_p = false;
13268 ret = tree_expr_nonnegative_warnv_p (t, &strict_overflow_p);
13269 if (strict_overflow_p)
13270 fold_overflow_warning (("assuming signed overflow does not occur when "
13271 "determining that expression is always "
13272 "non-negative"),
13273 WARN_STRICT_OVERFLOW_MISC);
13274 return ret;
13278 /* Return true when (CODE OP0) is an address and is known to be nonzero.
13279 For floating point we further ensure that T is not denormal.
13280 Similar logic is present in nonzero_address in rtlanal.h.
13282 If the return value is based on the assumption that signed overflow
13283 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
13284 change *STRICT_OVERFLOW_P. */
13286 bool
13287 tree_unary_nonzero_warnv_p (enum tree_code code, tree type, tree op0,
13288 bool *strict_overflow_p)
13290 switch (code)
13292 case ABS_EXPR:
13293 return tree_expr_nonzero_warnv_p (op0,
13294 strict_overflow_p);
13296 case NOP_EXPR:
13298 tree inner_type = TREE_TYPE (op0);
13299 tree outer_type = type;
13301 return (TYPE_PRECISION (outer_type) >= TYPE_PRECISION (inner_type)
13302 && tree_expr_nonzero_warnv_p (op0,
13303 strict_overflow_p));
13305 break;
13307 case NON_LVALUE_EXPR:
13308 return tree_expr_nonzero_warnv_p (op0,
13309 strict_overflow_p);
13311 default:
13312 break;
13315 return false;
13318 /* Return true when (CODE OP0 OP1) is an address and is known to be nonzero.
13319 For floating point we further ensure that T is not denormal.
13320 Similar logic is present in nonzero_address in rtlanal.h.
13322 If the return value is based on the assumption that signed overflow
13323 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
13324 change *STRICT_OVERFLOW_P. */
13326 bool
13327 tree_binary_nonzero_warnv_p (enum tree_code code,
13328 tree type,
13329 tree op0,
13330 tree op1, bool *strict_overflow_p)
13332 bool sub_strict_overflow_p;
13333 switch (code)
13335 case POINTER_PLUS_EXPR:
13336 case PLUS_EXPR:
13337 if (ANY_INTEGRAL_TYPE_P (type) && TYPE_OVERFLOW_UNDEFINED (type))
13339 /* With the presence of negative values it is hard
13340 to say something. */
13341 sub_strict_overflow_p = false;
13342 if (!tree_expr_nonnegative_warnv_p (op0,
13343 &sub_strict_overflow_p)
13344 || !tree_expr_nonnegative_warnv_p (op1,
13345 &sub_strict_overflow_p))
13346 return false;
13347 /* One of operands must be positive and the other non-negative. */
13348 /* We don't set *STRICT_OVERFLOW_P here: even if this value
13349 overflows, on a twos-complement machine the sum of two
13350 nonnegative numbers can never be zero. */
13351 return (tree_expr_nonzero_warnv_p (op0,
13352 strict_overflow_p)
13353 || tree_expr_nonzero_warnv_p (op1,
13354 strict_overflow_p));
13356 break;
13358 case MULT_EXPR:
13359 if (TYPE_OVERFLOW_UNDEFINED (type))
13361 if (tree_expr_nonzero_warnv_p (op0,
13362 strict_overflow_p)
13363 && tree_expr_nonzero_warnv_p (op1,
13364 strict_overflow_p))
13366 *strict_overflow_p = true;
13367 return true;
13370 break;
13372 case MIN_EXPR:
13373 sub_strict_overflow_p = false;
13374 if (tree_expr_nonzero_warnv_p (op0,
13375 &sub_strict_overflow_p)
13376 && tree_expr_nonzero_warnv_p (op1,
13377 &sub_strict_overflow_p))
13379 if (sub_strict_overflow_p)
13380 *strict_overflow_p = true;
13382 break;
13384 case MAX_EXPR:
13385 sub_strict_overflow_p = false;
13386 if (tree_expr_nonzero_warnv_p (op0,
13387 &sub_strict_overflow_p))
13389 if (sub_strict_overflow_p)
13390 *strict_overflow_p = true;
13392 /* When both operands are nonzero, then MAX must be too. */
13393 if (tree_expr_nonzero_warnv_p (op1,
13394 strict_overflow_p))
13395 return true;
13397 /* MAX where operand 0 is positive is positive. */
13398 return tree_expr_nonnegative_warnv_p (op0,
13399 strict_overflow_p);
13401 /* MAX where operand 1 is positive is positive. */
13402 else if (tree_expr_nonzero_warnv_p (op1,
13403 &sub_strict_overflow_p)
13404 && tree_expr_nonnegative_warnv_p (op1,
13405 &sub_strict_overflow_p))
13407 if (sub_strict_overflow_p)
13408 *strict_overflow_p = true;
13409 return true;
13411 break;
13413 case BIT_IOR_EXPR:
13414 return (tree_expr_nonzero_warnv_p (op1,
13415 strict_overflow_p)
13416 || tree_expr_nonzero_warnv_p (op0,
13417 strict_overflow_p));
13419 default:
13420 break;
13423 return false;
13426 /* Return true when T is an address and is known to be nonzero.
13427 For floating point we further ensure that T is not denormal.
13428 Similar logic is present in nonzero_address in rtlanal.h.
13430 If the return value is based on the assumption that signed overflow
13431 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
13432 change *STRICT_OVERFLOW_P. */
13434 bool
13435 tree_single_nonzero_warnv_p (tree t, bool *strict_overflow_p)
13437 bool sub_strict_overflow_p;
13438 switch (TREE_CODE (t))
13440 case INTEGER_CST:
13441 return !integer_zerop (t);
13443 case ADDR_EXPR:
13445 tree base = TREE_OPERAND (t, 0);
13447 if (!DECL_P (base))
13448 base = get_base_address (base);
13450 if (base && TREE_CODE (base) == TARGET_EXPR)
13451 base = TARGET_EXPR_SLOT (base);
13453 if (!base)
13454 return false;
13456 /* For objects in symbol table check if we know they are non-zero.
13457 Don't do anything for variables and functions before symtab is built;
13458 it is quite possible that they will be declared weak later. */
13459 int nonzero_addr = maybe_nonzero_address (base);
13460 if (nonzero_addr >= 0)
13461 return nonzero_addr;
13463 /* Constants are never weak. */
13464 if (CONSTANT_CLASS_P (base))
13465 return true;
13467 return false;
13470 case COND_EXPR:
13471 sub_strict_overflow_p = false;
13472 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
13473 &sub_strict_overflow_p)
13474 && tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 2),
13475 &sub_strict_overflow_p))
13477 if (sub_strict_overflow_p)
13478 *strict_overflow_p = true;
13479 return true;
13481 break;
13483 case SSA_NAME:
13484 if (!INTEGRAL_TYPE_P (TREE_TYPE (t)))
13485 break;
13486 return expr_not_equal_to (t, wi::zero (TYPE_PRECISION (TREE_TYPE (t))));
13488 default:
13489 break;
13491 return false;
13494 #define integer_valued_real_p(X) \
13495 _Pragma ("GCC error \"Use RECURSE for recursive calls\"") 0
13497 #define RECURSE(X) \
13498 ((integer_valued_real_p) (X, depth + 1))
13500 /* Return true if the floating point result of (CODE OP0) has an
13501 integer value. We also allow +Inf, -Inf and NaN to be considered
13502 integer values. Return false for signaling NaN.
13504 DEPTH is the current nesting depth of the query. */
13506 bool
13507 integer_valued_real_unary_p (tree_code code, tree op0, int depth)
13509 switch (code)
13511 case FLOAT_EXPR:
13512 return true;
13514 case ABS_EXPR:
13515 return RECURSE (op0);
13517 CASE_CONVERT:
13519 tree type = TREE_TYPE (op0);
13520 if (TREE_CODE (type) == INTEGER_TYPE)
13521 return true;
13522 if (TREE_CODE (type) == REAL_TYPE)
13523 return RECURSE (op0);
13524 break;
13527 default:
13528 break;
13530 return false;
13533 /* Return true if the floating point result of (CODE OP0 OP1) has an
13534 integer value. We also allow +Inf, -Inf and NaN to be considered
13535 integer values. Return false for signaling NaN.
13537 DEPTH is the current nesting depth of the query. */
13539 bool
13540 integer_valued_real_binary_p (tree_code code, tree op0, tree op1, int depth)
13542 switch (code)
13544 case PLUS_EXPR:
13545 case MINUS_EXPR:
13546 case MULT_EXPR:
13547 case MIN_EXPR:
13548 case MAX_EXPR:
13549 return RECURSE (op0) && RECURSE (op1);
13551 default:
13552 break;
13554 return false;
13557 /* Return true if the floating point result of calling FNDECL with arguments
13558 ARG0 and ARG1 has an integer value. We also allow +Inf, -Inf and NaN to be
13559 considered integer values. Return false for signaling NaN. If FNDECL
13560 takes fewer than 2 arguments, the remaining ARGn are null.
13562 DEPTH is the current nesting depth of the query. */
13564 bool
13565 integer_valued_real_call_p (combined_fn fn, tree arg0, tree arg1, int depth)
13567 switch (fn)
13569 CASE_CFN_CEIL:
13570 CASE_CFN_CEIL_FN:
13571 CASE_CFN_FLOOR:
13572 CASE_CFN_FLOOR_FN:
13573 CASE_CFN_NEARBYINT:
13574 CASE_CFN_NEARBYINT_FN:
13575 CASE_CFN_RINT:
13576 CASE_CFN_RINT_FN:
13577 CASE_CFN_ROUND:
13578 CASE_CFN_ROUND_FN:
13579 CASE_CFN_TRUNC:
13580 CASE_CFN_TRUNC_FN:
13581 return true;
13583 CASE_CFN_FMIN:
13584 CASE_CFN_FMIN_FN:
13585 CASE_CFN_FMAX:
13586 CASE_CFN_FMAX_FN:
13587 return RECURSE (arg0) && RECURSE (arg1);
13589 default:
13590 break;
13592 return false;
13595 /* Return true if the floating point expression T (a GIMPLE_SINGLE_RHS)
13596 has an integer value. We also allow +Inf, -Inf and NaN to be
13597 considered integer values. Return false for signaling NaN.
13599 DEPTH is the current nesting depth of the query. */
13601 bool
13602 integer_valued_real_single_p (tree t, int depth)
13604 switch (TREE_CODE (t))
13606 case REAL_CST:
13607 return real_isinteger (TREE_REAL_CST_PTR (t), TYPE_MODE (TREE_TYPE (t)));
13609 case COND_EXPR:
13610 return RECURSE (TREE_OPERAND (t, 1)) && RECURSE (TREE_OPERAND (t, 2));
13612 case SSA_NAME:
13613 /* Limit the depth of recursion to avoid quadratic behavior.
13614 This is expected to catch almost all occurrences in practice.
13615 If this code misses important cases that unbounded recursion
13616 would not, passes that need this information could be revised
13617 to provide it through dataflow propagation. */
13618 return (!name_registered_for_update_p (t)
13619 && depth < PARAM_VALUE (PARAM_MAX_SSA_NAME_QUERY_DEPTH)
13620 && gimple_stmt_integer_valued_real_p (SSA_NAME_DEF_STMT (t),
13621 depth));
13623 default:
13624 break;
13626 return false;
13629 /* Return true if the floating point expression T (a GIMPLE_INVALID_RHS)
13630 has an integer value. We also allow +Inf, -Inf and NaN to be
13631 considered integer values. Return false for signaling NaN.
13633 DEPTH is the current nesting depth of the query. */
13635 static bool
13636 integer_valued_real_invalid_p (tree t, int depth)
13638 switch (TREE_CODE (t))
13640 case COMPOUND_EXPR:
13641 case MODIFY_EXPR:
13642 case BIND_EXPR:
13643 return RECURSE (TREE_OPERAND (t, 1));
13645 case SAVE_EXPR:
13646 return RECURSE (TREE_OPERAND (t, 0));
13648 default:
13649 break;
13651 return false;
13654 #undef RECURSE
13655 #undef integer_valued_real_p
13657 /* Return true if the floating point expression T has an integer value.
13658 We also allow +Inf, -Inf and NaN to be considered integer values.
13659 Return false for signaling NaN.
13661 DEPTH is the current nesting depth of the query. */
13663 bool
13664 integer_valued_real_p (tree t, int depth)
13666 if (t == error_mark_node)
13667 return false;
13669 tree_code code = TREE_CODE (t);
13670 switch (TREE_CODE_CLASS (code))
13672 case tcc_binary:
13673 case tcc_comparison:
13674 return integer_valued_real_binary_p (code, TREE_OPERAND (t, 0),
13675 TREE_OPERAND (t, 1), depth);
13677 case tcc_unary:
13678 return integer_valued_real_unary_p (code, TREE_OPERAND (t, 0), depth);
13680 case tcc_constant:
13681 case tcc_declaration:
13682 case tcc_reference:
13683 return integer_valued_real_single_p (t, depth);
13685 default:
13686 break;
13689 switch (code)
13691 case COND_EXPR:
13692 case SSA_NAME:
13693 return integer_valued_real_single_p (t, depth);
13695 case CALL_EXPR:
13697 tree arg0 = (call_expr_nargs (t) > 0
13698 ? CALL_EXPR_ARG (t, 0)
13699 : NULL_TREE);
13700 tree arg1 = (call_expr_nargs (t) > 1
13701 ? CALL_EXPR_ARG (t, 1)
13702 : NULL_TREE);
13703 return integer_valued_real_call_p (get_call_combined_fn (t),
13704 arg0, arg1, depth);
13707 default:
13708 return integer_valued_real_invalid_p (t, depth);
13712 /* Given the components of a binary expression CODE, TYPE, OP0 and OP1,
13713 attempt to fold the expression to a constant without modifying TYPE,
13714 OP0 or OP1.
13716 If the expression could be simplified to a constant, then return
13717 the constant. If the expression would not be simplified to a
13718 constant, then return NULL_TREE. */
13720 tree
13721 fold_binary_to_constant (enum tree_code code, tree type, tree op0, tree op1)
13723 tree tem = fold_binary (code, type, op0, op1);
13724 return (tem && TREE_CONSTANT (tem)) ? tem : NULL_TREE;
13727 /* Given the components of a unary expression CODE, TYPE and OP0,
13728 attempt to fold the expression to a constant without modifying
13729 TYPE or OP0.
13731 If the expression could be simplified to a constant, then return
13732 the constant. If the expression would not be simplified to a
13733 constant, then return NULL_TREE. */
13735 tree
13736 fold_unary_to_constant (enum tree_code code, tree type, tree op0)
13738 tree tem = fold_unary (code, type, op0);
13739 return (tem && TREE_CONSTANT (tem)) ? tem : NULL_TREE;
13742 /* If EXP represents referencing an element in a constant string
13743 (either via pointer arithmetic or array indexing), return the
13744 tree representing the value accessed, otherwise return NULL. */
13746 tree
13747 fold_read_from_constant_string (tree exp)
13749 if ((TREE_CODE (exp) == INDIRECT_REF
13750 || TREE_CODE (exp) == ARRAY_REF)
13751 && TREE_CODE (TREE_TYPE (exp)) == INTEGER_TYPE)
13753 tree exp1 = TREE_OPERAND (exp, 0);
13754 tree index;
13755 tree string;
13756 location_t loc = EXPR_LOCATION (exp);
13758 if (TREE_CODE (exp) == INDIRECT_REF)
13759 string = string_constant (exp1, &index);
13760 else
13762 tree low_bound = array_ref_low_bound (exp);
13763 index = fold_convert_loc (loc, sizetype, TREE_OPERAND (exp, 1));
13765 /* Optimize the special-case of a zero lower bound.
13767 We convert the low_bound to sizetype to avoid some problems
13768 with constant folding. (E.g. suppose the lower bound is 1,
13769 and its mode is QI. Without the conversion,l (ARRAY
13770 +(INDEX-(unsigned char)1)) becomes ((ARRAY+(-(unsigned char)1))
13771 +INDEX), which becomes (ARRAY+255+INDEX). Oops!) */
13772 if (! integer_zerop (low_bound))
13773 index = size_diffop_loc (loc, index,
13774 fold_convert_loc (loc, sizetype, low_bound));
13776 string = exp1;
13779 scalar_int_mode char_mode;
13780 if (string
13781 && TYPE_MODE (TREE_TYPE (exp)) == TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))
13782 && TREE_CODE (string) == STRING_CST
13783 && TREE_CODE (index) == INTEGER_CST
13784 && compare_tree_int (index, TREE_STRING_LENGTH (string)) < 0
13785 && is_int_mode (TYPE_MODE (TREE_TYPE (TREE_TYPE (string))),
13786 &char_mode)
13787 && GET_MODE_SIZE (char_mode) == 1)
13788 return build_int_cst_type (TREE_TYPE (exp),
13789 (TREE_STRING_POINTER (string)
13790 [TREE_INT_CST_LOW (index)]));
13792 return NULL;
13795 /* Return the tree for neg (ARG0) when ARG0 is known to be either
13796 an integer constant, real, or fixed-point constant.
13798 TYPE is the type of the result. */
13800 static tree
13801 fold_negate_const (tree arg0, tree type)
13803 tree t = NULL_TREE;
13805 switch (TREE_CODE (arg0))
13807 case REAL_CST:
13808 t = build_real (type, real_value_negate (&TREE_REAL_CST (arg0)));
13809 break;
13811 case FIXED_CST:
13813 FIXED_VALUE_TYPE f;
13814 bool overflow_p = fixed_arithmetic (&f, NEGATE_EXPR,
13815 &(TREE_FIXED_CST (arg0)), NULL,
13816 TYPE_SATURATING (type));
13817 t = build_fixed (type, f);
13818 /* Propagate overflow flags. */
13819 if (overflow_p | TREE_OVERFLOW (arg0))
13820 TREE_OVERFLOW (t) = 1;
13821 break;
13824 default:
13825 if (poly_int_tree_p (arg0))
13827 bool overflow;
13828 poly_wide_int res = wi::neg (wi::to_poly_wide (arg0), &overflow);
13829 t = force_fit_type (type, res, 1,
13830 (overflow && ! TYPE_UNSIGNED (type))
13831 || TREE_OVERFLOW (arg0));
13832 break;
13835 gcc_unreachable ();
13838 return t;
13841 /* Return the tree for abs (ARG0) when ARG0 is known to be either
13842 an integer constant or real constant.
13844 TYPE is the type of the result. */
13846 tree
13847 fold_abs_const (tree arg0, tree type)
13849 tree t = NULL_TREE;
13851 switch (TREE_CODE (arg0))
13853 case INTEGER_CST:
13855 /* If the value is unsigned or non-negative, then the absolute value
13856 is the same as the ordinary value. */
13857 if (!wi::neg_p (wi::to_wide (arg0), TYPE_SIGN (type)))
13858 t = arg0;
13860 /* If the value is negative, then the absolute value is
13861 its negation. */
13862 else
13864 bool overflow;
13865 wide_int val = wi::neg (wi::to_wide (arg0), &overflow);
13866 t = force_fit_type (type, val, -1,
13867 overflow | TREE_OVERFLOW (arg0));
13870 break;
13872 case REAL_CST:
13873 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
13874 t = build_real (type, real_value_negate (&TREE_REAL_CST (arg0)));
13875 else
13876 t = arg0;
13877 break;
13879 default:
13880 gcc_unreachable ();
13883 return t;
13886 /* Return the tree for not (ARG0) when ARG0 is known to be an integer
13887 constant. TYPE is the type of the result. */
13889 static tree
13890 fold_not_const (const_tree arg0, tree type)
13892 gcc_assert (TREE_CODE (arg0) == INTEGER_CST);
13894 return force_fit_type (type, ~wi::to_wide (arg0), 0, TREE_OVERFLOW (arg0));
13897 /* Given CODE, a relational operator, the target type, TYPE and two
13898 constant operands OP0 and OP1, return the result of the
13899 relational operation. If the result is not a compile time
13900 constant, then return NULL_TREE. */
13902 static tree
13903 fold_relational_const (enum tree_code code, tree type, tree op0, tree op1)
13905 int result, invert;
13907 /* From here on, the only cases we handle are when the result is
13908 known to be a constant. */
13910 if (TREE_CODE (op0) == REAL_CST && TREE_CODE (op1) == REAL_CST)
13912 const REAL_VALUE_TYPE *c0 = TREE_REAL_CST_PTR (op0);
13913 const REAL_VALUE_TYPE *c1 = TREE_REAL_CST_PTR (op1);
13915 /* Handle the cases where either operand is a NaN. */
13916 if (real_isnan (c0) || real_isnan (c1))
13918 switch (code)
13920 case EQ_EXPR:
13921 case ORDERED_EXPR:
13922 result = 0;
13923 break;
13925 case NE_EXPR:
13926 case UNORDERED_EXPR:
13927 case UNLT_EXPR:
13928 case UNLE_EXPR:
13929 case UNGT_EXPR:
13930 case UNGE_EXPR:
13931 case UNEQ_EXPR:
13932 result = 1;
13933 break;
13935 case LT_EXPR:
13936 case LE_EXPR:
13937 case GT_EXPR:
13938 case GE_EXPR:
13939 case LTGT_EXPR:
13940 if (flag_trapping_math)
13941 return NULL_TREE;
13942 result = 0;
13943 break;
13945 default:
13946 gcc_unreachable ();
13949 return constant_boolean_node (result, type);
13952 return constant_boolean_node (real_compare (code, c0, c1), type);
13955 if (TREE_CODE (op0) == FIXED_CST && TREE_CODE (op1) == FIXED_CST)
13957 const FIXED_VALUE_TYPE *c0 = TREE_FIXED_CST_PTR (op0);
13958 const FIXED_VALUE_TYPE *c1 = TREE_FIXED_CST_PTR (op1);
13959 return constant_boolean_node (fixed_compare (code, c0, c1), type);
13962 /* Handle equality/inequality of complex constants. */
13963 if (TREE_CODE (op0) == COMPLEX_CST && TREE_CODE (op1) == COMPLEX_CST)
13965 tree rcond = fold_relational_const (code, type,
13966 TREE_REALPART (op0),
13967 TREE_REALPART (op1));
13968 tree icond = fold_relational_const (code, type,
13969 TREE_IMAGPART (op0),
13970 TREE_IMAGPART (op1));
13971 if (code == EQ_EXPR)
13972 return fold_build2 (TRUTH_ANDIF_EXPR, type, rcond, icond);
13973 else if (code == NE_EXPR)
13974 return fold_build2 (TRUTH_ORIF_EXPR, type, rcond, icond);
13975 else
13976 return NULL_TREE;
13979 if (TREE_CODE (op0) == VECTOR_CST && TREE_CODE (op1) == VECTOR_CST)
13981 if (!VECTOR_TYPE_P (type))
13983 /* Have vector comparison with scalar boolean result. */
13984 gcc_assert ((code == EQ_EXPR || code == NE_EXPR)
13985 && known_eq (VECTOR_CST_NELTS (op0),
13986 VECTOR_CST_NELTS (op1)));
13987 unsigned HOST_WIDE_INT nunits;
13988 if (!VECTOR_CST_NELTS (op0).is_constant (&nunits))
13989 return NULL_TREE;
13990 for (unsigned i = 0; i < nunits; i++)
13992 tree elem0 = VECTOR_CST_ELT (op0, i);
13993 tree elem1 = VECTOR_CST_ELT (op1, i);
13994 tree tmp = fold_relational_const (code, type, elem0, elem1);
13995 if (tmp == NULL_TREE)
13996 return NULL_TREE;
13997 if (integer_zerop (tmp))
13998 return constant_boolean_node (false, type);
14000 return constant_boolean_node (true, type);
14002 tree_vector_builder elts;
14003 if (!elts.new_binary_operation (type, op0, op1, false))
14004 return NULL_TREE;
14005 unsigned int count = elts.encoded_nelts ();
14006 for (unsigned i = 0; i < count; i++)
14008 tree elem_type = TREE_TYPE (type);
14009 tree elem0 = VECTOR_CST_ELT (op0, i);
14010 tree elem1 = VECTOR_CST_ELT (op1, i);
14012 tree tem = fold_relational_const (code, elem_type,
14013 elem0, elem1);
14015 if (tem == NULL_TREE)
14016 return NULL_TREE;
14018 elts.quick_push (build_int_cst (elem_type,
14019 integer_zerop (tem) ? 0 : -1));
14022 return elts.build ();
14025 /* From here on we only handle LT, LE, GT, GE, EQ and NE.
14027 To compute GT, swap the arguments and do LT.
14028 To compute GE, do LT and invert the result.
14029 To compute LE, swap the arguments, do LT and invert the result.
14030 To compute NE, do EQ and invert the result.
14032 Therefore, the code below must handle only EQ and LT. */
14034 if (code == LE_EXPR || code == GT_EXPR)
14036 std::swap (op0, op1);
14037 code = swap_tree_comparison (code);
14040 /* Note that it is safe to invert for real values here because we
14041 have already handled the one case that it matters. */
14043 invert = 0;
14044 if (code == NE_EXPR || code == GE_EXPR)
14046 invert = 1;
14047 code = invert_tree_comparison (code, false);
14050 /* Compute a result for LT or EQ if args permit;
14051 Otherwise return T. */
14052 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
14054 if (code == EQ_EXPR)
14055 result = tree_int_cst_equal (op0, op1);
14056 else
14057 result = tree_int_cst_lt (op0, op1);
14059 else
14060 return NULL_TREE;
14062 if (invert)
14063 result ^= 1;
14064 return constant_boolean_node (result, type);
14067 /* If necessary, return a CLEANUP_POINT_EXPR for EXPR with the
14068 indicated TYPE. If no CLEANUP_POINT_EXPR is necessary, return EXPR
14069 itself. */
14071 tree
14072 fold_build_cleanup_point_expr (tree type, tree expr)
14074 /* If the expression does not have side effects then we don't have to wrap
14075 it with a cleanup point expression. */
14076 if (!TREE_SIDE_EFFECTS (expr))
14077 return expr;
14079 /* If the expression is a return, check to see if the expression inside the
14080 return has no side effects or the right hand side of the modify expression
14081 inside the return. If either don't have side effects set we don't need to
14082 wrap the expression in a cleanup point expression. Note we don't check the
14083 left hand side of the modify because it should always be a return decl. */
14084 if (TREE_CODE (expr) == RETURN_EXPR)
14086 tree op = TREE_OPERAND (expr, 0);
14087 if (!op || !TREE_SIDE_EFFECTS (op))
14088 return expr;
14089 op = TREE_OPERAND (op, 1);
14090 if (!TREE_SIDE_EFFECTS (op))
14091 return expr;
14094 return build1_loc (EXPR_LOCATION (expr), CLEANUP_POINT_EXPR, type, expr);
14097 /* Given a pointer value OP0 and a type TYPE, return a simplified version
14098 of an indirection through OP0, or NULL_TREE if no simplification is
14099 possible. */
14101 tree
14102 fold_indirect_ref_1 (location_t loc, tree type, tree op0)
14104 tree sub = op0;
14105 tree subtype;
14106 poly_uint64 const_op01;
14108 STRIP_NOPS (sub);
14109 subtype = TREE_TYPE (sub);
14110 if (!POINTER_TYPE_P (subtype)
14111 || TYPE_REF_CAN_ALIAS_ALL (TREE_TYPE (op0)))
14112 return NULL_TREE;
14114 if (TREE_CODE (sub) == ADDR_EXPR)
14116 tree op = TREE_OPERAND (sub, 0);
14117 tree optype = TREE_TYPE (op);
14118 /* *&CONST_DECL -> to the value of the const decl. */
14119 if (TREE_CODE (op) == CONST_DECL)
14120 return DECL_INITIAL (op);
14121 /* *&p => p; make sure to handle *&"str"[cst] here. */
14122 if (type == optype)
14124 tree fop = fold_read_from_constant_string (op);
14125 if (fop)
14126 return fop;
14127 else
14128 return op;
14130 /* *(foo *)&fooarray => fooarray[0] */
14131 else if (TREE_CODE (optype) == ARRAY_TYPE
14132 && type == TREE_TYPE (optype)
14133 && (!in_gimple_form
14134 || TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST))
14136 tree type_domain = TYPE_DOMAIN (optype);
14137 tree min_val = size_zero_node;
14138 if (type_domain && TYPE_MIN_VALUE (type_domain))
14139 min_val = TYPE_MIN_VALUE (type_domain);
14140 if (in_gimple_form
14141 && TREE_CODE (min_val) != INTEGER_CST)
14142 return NULL_TREE;
14143 return build4_loc (loc, ARRAY_REF, type, op, min_val,
14144 NULL_TREE, NULL_TREE);
14146 /* *(foo *)&complexfoo => __real__ complexfoo */
14147 else if (TREE_CODE (optype) == COMPLEX_TYPE
14148 && type == TREE_TYPE (optype))
14149 return fold_build1_loc (loc, REALPART_EXPR, type, op);
14150 /* *(foo *)&vectorfoo => BIT_FIELD_REF<vectorfoo,...> */
14151 else if (TREE_CODE (optype) == VECTOR_TYPE
14152 && type == TREE_TYPE (optype))
14154 tree part_width = TYPE_SIZE (type);
14155 tree index = bitsize_int (0);
14156 return fold_build3_loc (loc, BIT_FIELD_REF, type, op, part_width, index);
14160 if (TREE_CODE (sub) == POINTER_PLUS_EXPR
14161 && poly_int_tree_p (TREE_OPERAND (sub, 1), &const_op01))
14163 tree op00 = TREE_OPERAND (sub, 0);
14164 tree op01 = TREE_OPERAND (sub, 1);
14166 STRIP_NOPS (op00);
14167 if (TREE_CODE (op00) == ADDR_EXPR)
14169 tree op00type;
14170 op00 = TREE_OPERAND (op00, 0);
14171 op00type = TREE_TYPE (op00);
14173 /* ((foo*)&vectorfoo)[1] => BIT_FIELD_REF<vectorfoo,...> */
14174 if (TREE_CODE (op00type) == VECTOR_TYPE
14175 && type == TREE_TYPE (op00type))
14177 tree part_width = TYPE_SIZE (type);
14178 poly_uint64 max_offset
14179 = (tree_to_uhwi (part_width) / BITS_PER_UNIT
14180 * TYPE_VECTOR_SUBPARTS (op00type));
14181 if (known_lt (const_op01, max_offset))
14183 tree index = bitsize_int (const_op01 * BITS_PER_UNIT);
14184 return fold_build3_loc (loc,
14185 BIT_FIELD_REF, type, op00,
14186 part_width, index);
14189 /* ((foo*)&complexfoo)[1] => __imag__ complexfoo */
14190 else if (TREE_CODE (op00type) == COMPLEX_TYPE
14191 && type == TREE_TYPE (op00type))
14193 if (known_eq (wi::to_poly_offset (TYPE_SIZE_UNIT (type)),
14194 const_op01))
14195 return fold_build1_loc (loc, IMAGPART_EXPR, type, op00);
14197 /* ((foo *)&fooarray)[1] => fooarray[1] */
14198 else if (TREE_CODE (op00type) == ARRAY_TYPE
14199 && type == TREE_TYPE (op00type))
14201 tree type_domain = TYPE_DOMAIN (op00type);
14202 tree min = size_zero_node;
14203 if (type_domain && TYPE_MIN_VALUE (type_domain))
14204 min = TYPE_MIN_VALUE (type_domain);
14205 offset_int off = wi::to_offset (op01);
14206 offset_int el_sz = wi::to_offset (TYPE_SIZE_UNIT (type));
14207 offset_int remainder;
14208 off = wi::divmod_trunc (off, el_sz, SIGNED, &remainder);
14209 if (remainder == 0 && TREE_CODE (min) == INTEGER_CST)
14211 off = off + wi::to_offset (min);
14212 op01 = wide_int_to_tree (sizetype, off);
14213 return build4_loc (loc, ARRAY_REF, type, op00, op01,
14214 NULL_TREE, NULL_TREE);
14220 /* *(foo *)fooarrptr => (*fooarrptr)[0] */
14221 if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE
14222 && type == TREE_TYPE (TREE_TYPE (subtype))
14223 && (!in_gimple_form
14224 || TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST))
14226 tree type_domain;
14227 tree min_val = size_zero_node;
14228 sub = build_fold_indirect_ref_loc (loc, sub);
14229 type_domain = TYPE_DOMAIN (TREE_TYPE (sub));
14230 if (type_domain && TYPE_MIN_VALUE (type_domain))
14231 min_val = TYPE_MIN_VALUE (type_domain);
14232 if (in_gimple_form
14233 && TREE_CODE (min_val) != INTEGER_CST)
14234 return NULL_TREE;
14235 return build4_loc (loc, ARRAY_REF, type, sub, min_val, NULL_TREE,
14236 NULL_TREE);
14239 return NULL_TREE;
14242 /* Builds an expression for an indirection through T, simplifying some
14243 cases. */
14245 tree
14246 build_fold_indirect_ref_loc (location_t loc, tree t)
14248 tree type = TREE_TYPE (TREE_TYPE (t));
14249 tree sub = fold_indirect_ref_1 (loc, type, t);
14251 if (sub)
14252 return sub;
14254 return build1_loc (loc, INDIRECT_REF, type, t);
14257 /* Given an INDIRECT_REF T, return either T or a simplified version. */
14259 tree
14260 fold_indirect_ref_loc (location_t loc, tree t)
14262 tree sub = fold_indirect_ref_1 (loc, TREE_TYPE (t), TREE_OPERAND (t, 0));
14264 if (sub)
14265 return sub;
14266 else
14267 return t;
14270 /* Strip non-trapping, non-side-effecting tree nodes from an expression
14271 whose result is ignored. The type of the returned tree need not be
14272 the same as the original expression. */
14274 tree
14275 fold_ignored_result (tree t)
14277 if (!TREE_SIDE_EFFECTS (t))
14278 return integer_zero_node;
14280 for (;;)
14281 switch (TREE_CODE_CLASS (TREE_CODE (t)))
14283 case tcc_unary:
14284 t = TREE_OPERAND (t, 0);
14285 break;
14287 case tcc_binary:
14288 case tcc_comparison:
14289 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
14290 t = TREE_OPERAND (t, 0);
14291 else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0)))
14292 t = TREE_OPERAND (t, 1);
14293 else
14294 return t;
14295 break;
14297 case tcc_expression:
14298 switch (TREE_CODE (t))
14300 case COMPOUND_EXPR:
14301 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
14302 return t;
14303 t = TREE_OPERAND (t, 0);
14304 break;
14306 case COND_EXPR:
14307 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1))
14308 || TREE_SIDE_EFFECTS (TREE_OPERAND (t, 2)))
14309 return t;
14310 t = TREE_OPERAND (t, 0);
14311 break;
14313 default:
14314 return t;
14316 break;
14318 default:
14319 return t;
14323 /* Return the value of VALUE, rounded up to a multiple of DIVISOR. */
14325 tree
14326 round_up_loc (location_t loc, tree value, unsigned int divisor)
14328 tree div = NULL_TREE;
14330 if (divisor == 1)
14331 return value;
14333 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
14334 have to do anything. Only do this when we are not given a const,
14335 because in that case, this check is more expensive than just
14336 doing it. */
14337 if (TREE_CODE (value) != INTEGER_CST)
14339 div = build_int_cst (TREE_TYPE (value), divisor);
14341 if (multiple_of_p (TREE_TYPE (value), value, div))
14342 return value;
14345 /* If divisor is a power of two, simplify this to bit manipulation. */
14346 if (pow2_or_zerop (divisor))
14348 if (TREE_CODE (value) == INTEGER_CST)
14350 wide_int val = wi::to_wide (value);
14351 bool overflow_p;
14353 if ((val & (divisor - 1)) == 0)
14354 return value;
14356 overflow_p = TREE_OVERFLOW (value);
14357 val += divisor - 1;
14358 val &= (int) -divisor;
14359 if (val == 0)
14360 overflow_p = true;
14362 return force_fit_type (TREE_TYPE (value), val, -1, overflow_p);
14364 else
14366 tree t;
14368 t = build_int_cst (TREE_TYPE (value), divisor - 1);
14369 value = size_binop_loc (loc, PLUS_EXPR, value, t);
14370 t = build_int_cst (TREE_TYPE (value), - (int) divisor);
14371 value = size_binop_loc (loc, BIT_AND_EXPR, value, t);
14374 else
14376 if (!div)
14377 div = build_int_cst (TREE_TYPE (value), divisor);
14378 value = size_binop_loc (loc, CEIL_DIV_EXPR, value, div);
14379 value = size_binop_loc (loc, MULT_EXPR, value, div);
14382 return value;
14385 /* Likewise, but round down. */
14387 tree
14388 round_down_loc (location_t loc, tree value, int divisor)
14390 tree div = NULL_TREE;
14392 gcc_assert (divisor > 0);
14393 if (divisor == 1)
14394 return value;
14396 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
14397 have to do anything. Only do this when we are not given a const,
14398 because in that case, this check is more expensive than just
14399 doing it. */
14400 if (TREE_CODE (value) != INTEGER_CST)
14402 div = build_int_cst (TREE_TYPE (value), divisor);
14404 if (multiple_of_p (TREE_TYPE (value), value, div))
14405 return value;
14408 /* If divisor is a power of two, simplify this to bit manipulation. */
14409 if (pow2_or_zerop (divisor))
14411 tree t;
14413 t = build_int_cst (TREE_TYPE (value), -divisor);
14414 value = size_binop_loc (loc, BIT_AND_EXPR, value, t);
14416 else
14418 if (!div)
14419 div = build_int_cst (TREE_TYPE (value), divisor);
14420 value = size_binop_loc (loc, FLOOR_DIV_EXPR, value, div);
14421 value = size_binop_loc (loc, MULT_EXPR, value, div);
14424 return value;
14427 /* Returns the pointer to the base of the object addressed by EXP and
14428 extracts the information about the offset of the access, storing it
14429 to PBITPOS and POFFSET. */
14431 static tree
14432 split_address_to_core_and_offset (tree exp,
14433 poly_int64_pod *pbitpos, tree *poffset)
14435 tree core;
14436 machine_mode mode;
14437 int unsignedp, reversep, volatilep;
14438 poly_int64 bitsize;
14439 location_t loc = EXPR_LOCATION (exp);
14441 if (TREE_CODE (exp) == ADDR_EXPR)
14443 core = get_inner_reference (TREE_OPERAND (exp, 0), &bitsize, pbitpos,
14444 poffset, &mode, &unsignedp, &reversep,
14445 &volatilep);
14446 core = build_fold_addr_expr_loc (loc, core);
14448 else if (TREE_CODE (exp) == POINTER_PLUS_EXPR)
14450 core = TREE_OPERAND (exp, 0);
14451 STRIP_NOPS (core);
14452 *pbitpos = 0;
14453 *poffset = TREE_OPERAND (exp, 1);
14454 if (poly_int_tree_p (*poffset))
14456 poly_offset_int tem
14457 = wi::sext (wi::to_poly_offset (*poffset),
14458 TYPE_PRECISION (TREE_TYPE (*poffset)));
14459 tem <<= LOG2_BITS_PER_UNIT;
14460 if (tem.to_shwi (pbitpos))
14461 *poffset = NULL_TREE;
14464 else
14466 core = exp;
14467 *pbitpos = 0;
14468 *poffset = NULL_TREE;
14471 return core;
14474 /* Returns true if addresses of E1 and E2 differ by a constant, false
14475 otherwise. If they do, E1 - E2 is stored in *DIFF. */
14477 bool
14478 ptr_difference_const (tree e1, tree e2, poly_int64_pod *diff)
14480 tree core1, core2;
14481 poly_int64 bitpos1, bitpos2;
14482 tree toffset1, toffset2, tdiff, type;
14484 core1 = split_address_to_core_and_offset (e1, &bitpos1, &toffset1);
14485 core2 = split_address_to_core_and_offset (e2, &bitpos2, &toffset2);
14487 poly_int64 bytepos1, bytepos2;
14488 if (!multiple_p (bitpos1, BITS_PER_UNIT, &bytepos1)
14489 || !multiple_p (bitpos2, BITS_PER_UNIT, &bytepos2)
14490 || !operand_equal_p (core1, core2, 0))
14491 return false;
14493 if (toffset1 && toffset2)
14495 type = TREE_TYPE (toffset1);
14496 if (type != TREE_TYPE (toffset2))
14497 toffset2 = fold_convert (type, toffset2);
14499 tdiff = fold_build2 (MINUS_EXPR, type, toffset1, toffset2);
14500 if (!cst_and_fits_in_hwi (tdiff))
14501 return false;
14503 *diff = int_cst_value (tdiff);
14505 else if (toffset1 || toffset2)
14507 /* If only one of the offsets is non-constant, the difference cannot
14508 be a constant. */
14509 return false;
14511 else
14512 *diff = 0;
14514 *diff += bytepos1 - bytepos2;
14515 return true;
14518 /* Return OFF converted to a pointer offset type suitable as offset for
14519 POINTER_PLUS_EXPR. Use location LOC for this conversion. */
14520 tree
14521 convert_to_ptrofftype_loc (location_t loc, tree off)
14523 return fold_convert_loc (loc, sizetype, off);
14526 /* Build and fold a POINTER_PLUS_EXPR at LOC offsetting PTR by OFF. */
14527 tree
14528 fold_build_pointer_plus_loc (location_t loc, tree ptr, tree off)
14530 return fold_build2_loc (loc, POINTER_PLUS_EXPR, TREE_TYPE (ptr),
14531 ptr, convert_to_ptrofftype_loc (loc, off));
14534 /* Build and fold a POINTER_PLUS_EXPR at LOC offsetting PTR by OFF. */
14535 tree
14536 fold_build_pointer_plus_hwi_loc (location_t loc, tree ptr, HOST_WIDE_INT off)
14538 return fold_build2_loc (loc, POINTER_PLUS_EXPR, TREE_TYPE (ptr),
14539 ptr, size_int (off));
14542 /* Return a char pointer for a C string if it is a string constant
14543 or sum of string constant and integer constant. We only support
14544 string constants properly terminated with '\0' character.
14545 If STRLEN is a valid pointer, length (including terminating character)
14546 of returned string is stored to the argument. */
14548 const char *
14549 c_getstr (tree src, unsigned HOST_WIDE_INT *strlen)
14551 tree offset_node;
14553 if (strlen)
14554 *strlen = 0;
14556 src = string_constant (src, &offset_node);
14557 if (src == 0)
14558 return NULL;
14560 unsigned HOST_WIDE_INT offset = 0;
14561 if (offset_node != NULL_TREE)
14563 if (!tree_fits_uhwi_p (offset_node))
14564 return NULL;
14565 else
14566 offset = tree_to_uhwi (offset_node);
14569 unsigned HOST_WIDE_INT string_length = TREE_STRING_LENGTH (src);
14570 const char *string = TREE_STRING_POINTER (src);
14572 /* Support only properly null-terminated strings. */
14573 if (string_length == 0
14574 || string[string_length - 1] != '\0'
14575 || offset >= string_length)
14576 return NULL;
14578 if (strlen)
14579 *strlen = string_length - offset;
14580 return string + offset;
14583 #if CHECKING_P
14585 namespace selftest {
14587 /* Helper functions for writing tests of folding trees. */
14589 /* Verify that the binary op (LHS CODE RHS) folds to CONSTANT. */
14591 static void
14592 assert_binop_folds_to_const (tree lhs, enum tree_code code, tree rhs,
14593 tree constant)
14595 ASSERT_EQ (constant, fold_build2 (code, TREE_TYPE (lhs), lhs, rhs));
14598 /* Verify that the binary op (LHS CODE RHS) folds to an NON_LVALUE_EXPR
14599 wrapping WRAPPED_EXPR. */
14601 static void
14602 assert_binop_folds_to_nonlvalue (tree lhs, enum tree_code code, tree rhs,
14603 tree wrapped_expr)
14605 tree result = fold_build2 (code, TREE_TYPE (lhs), lhs, rhs);
14606 ASSERT_NE (wrapped_expr, result);
14607 ASSERT_EQ (NON_LVALUE_EXPR, TREE_CODE (result));
14608 ASSERT_EQ (wrapped_expr, TREE_OPERAND (result, 0));
14611 /* Verify that various arithmetic binary operations are folded
14612 correctly. */
14614 static void
14615 test_arithmetic_folding ()
14617 tree type = integer_type_node;
14618 tree x = create_tmp_var_raw (type, "x");
14619 tree zero = build_zero_cst (type);
14620 tree one = build_int_cst (type, 1);
14622 /* Addition. */
14623 /* 1 <-- (0 + 1) */
14624 assert_binop_folds_to_const (zero, PLUS_EXPR, one,
14625 one);
14626 assert_binop_folds_to_const (one, PLUS_EXPR, zero,
14627 one);
14629 /* (nonlvalue)x <-- (x + 0) */
14630 assert_binop_folds_to_nonlvalue (x, PLUS_EXPR, zero,
14633 /* Subtraction. */
14634 /* 0 <-- (x - x) */
14635 assert_binop_folds_to_const (x, MINUS_EXPR, x,
14636 zero);
14637 assert_binop_folds_to_nonlvalue (x, MINUS_EXPR, zero,
14640 /* Multiplication. */
14641 /* 0 <-- (x * 0) */
14642 assert_binop_folds_to_const (x, MULT_EXPR, zero,
14643 zero);
14645 /* (nonlvalue)x <-- (x * 1) */
14646 assert_binop_folds_to_nonlvalue (x, MULT_EXPR, one,
14650 /* Verify that various binary operations on vectors are folded
14651 correctly. */
14653 static void
14654 test_vector_folding ()
14656 tree inner_type = integer_type_node;
14657 tree type = build_vector_type (inner_type, 4);
14658 tree zero = build_zero_cst (type);
14659 tree one = build_one_cst (type);
14661 /* Verify equality tests that return a scalar boolean result. */
14662 tree res_type = boolean_type_node;
14663 ASSERT_FALSE (integer_nonzerop (fold_build2 (EQ_EXPR, res_type, zero, one)));
14664 ASSERT_TRUE (integer_nonzerop (fold_build2 (EQ_EXPR, res_type, zero, zero)));
14665 ASSERT_TRUE (integer_nonzerop (fold_build2 (NE_EXPR, res_type, zero, one)));
14666 ASSERT_FALSE (integer_nonzerop (fold_build2 (NE_EXPR, res_type, one, one)));
14669 /* Verify folding of VEC_DUPLICATE_EXPRs. */
14671 static void
14672 test_vec_duplicate_folding ()
14674 scalar_int_mode int_mode = SCALAR_INT_TYPE_MODE (ssizetype);
14675 machine_mode vec_mode = targetm.vectorize.preferred_simd_mode (int_mode);
14676 /* This will be 1 if VEC_MODE isn't a vector mode. */
14677 poly_uint64 nunits = GET_MODE_NUNITS (vec_mode);
14679 tree type = build_vector_type (ssizetype, nunits);
14680 tree dup5_expr = fold_unary (VEC_DUPLICATE_EXPR, type, ssize_int (5));
14681 tree dup5_cst = build_vector_from_val (type, ssize_int (5));
14682 ASSERT_TRUE (operand_equal_p (dup5_expr, dup5_cst, 0));
14685 /* Run all of the selftests within this file. */
14687 void
14688 fold_const_c_tests ()
14690 test_arithmetic_folding ();
14691 test_vector_folding ();
14692 test_vec_duplicate_folding ();
14695 } // namespace selftest
14697 #endif /* CHECKING_P */