1 /* Fold a constant sub-tree into a single node for C-compiler
2 Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
3 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
4 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 2, or (at your option) any later
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING. If not, write to the Free
20 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
23 /*@@ This file should be rewritten to use an arbitrary precision
24 @@ representation for "struct tree_int_cst" and "struct tree_real_cst".
25 @@ Perhaps the routines could also be used for bc/dc, and made a lib.
26 @@ The routines that translate from the ap rep should
27 @@ warn if precision et. al. is lost.
28 @@ This would also make life easier when this technology is used
29 @@ for cross-compilers. */
31 /* The entry points in this file are fold, size_int_wide, size_binop
32 and force_fit_type_double.
34 fold takes a tree as argument and returns a simplified tree.
36 size_binop takes a tree code for an arithmetic operation
37 and two operands that are trees, and produces a tree for the
38 result, assuming the type comes from `sizetype'.
40 size_int takes an integer value, and creates a tree constant
41 with type from `sizetype'.
43 force_fit_type_double takes a constant, an overflowable flag and a
44 prior overflow indicator. It forces the value to fit the type and
47 Note: Since the folders get called on non-gimple code as well as
48 gimple code, we need to handle GIMPLE tuples as well as their
49 corresponding tree equivalents. */
53 #include "coretypes.h"
65 #include "langhooks.h"
68 /* Non-zero if we are folding constants inside an initializer; zero
70 int folding_initializer = 0;
72 /* The following constants represent a bit based encoding of GCC's
73 comparison operators. This encoding simplifies transformations
74 on relational comparison operators, such as AND and OR. */
75 enum comparison_code {
94 static void encode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT, HOST_WIDE_INT);
95 static void decode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
96 static bool negate_mathfn_p (enum built_in_function);
97 static bool negate_expr_p (tree);
98 static tree negate_expr (tree);
99 static tree split_tree (tree, enum tree_code, tree *, tree *, tree *, int);
100 static tree associate_trees (tree, tree, enum tree_code, tree);
101 static tree const_binop (enum tree_code, tree, tree, int);
102 static enum comparison_code comparison_to_compcode (enum tree_code);
103 static enum tree_code compcode_to_comparison (enum comparison_code);
104 static tree combine_comparisons (enum tree_code, enum tree_code,
105 enum tree_code, tree, tree, tree);
106 static int truth_value_p (enum tree_code);
107 static int operand_equal_for_comparison_p (tree, tree, tree);
108 static int twoval_comparison_p (tree, tree *, tree *, int *);
109 static tree eval_subst (tree, tree, tree, tree, tree);
110 static tree pedantic_omit_one_operand (tree, tree, tree);
111 static tree distribute_bit_expr (enum tree_code, tree, tree, tree);
112 static tree make_bit_field_ref (tree, tree, int, int, int);
113 static tree optimize_bit_field_compare (enum tree_code, tree, tree, tree);
114 static tree decode_field_reference (tree, HOST_WIDE_INT *, HOST_WIDE_INT *,
115 enum machine_mode *, int *, int *,
117 static int all_ones_mask_p (tree, int);
118 static tree sign_bit_p (tree, tree);
119 static int simple_operand_p (tree);
120 static tree range_binop (enum tree_code, tree, tree, int, tree, int);
121 static tree range_predecessor (tree);
122 static tree range_successor (tree);
123 static tree make_range (tree, int *, tree *, tree *, bool *);
124 static tree build_range_check (tree, tree, int, tree, tree);
125 static int merge_ranges (int *, tree *, tree *, int, tree, tree, int, tree,
127 static tree fold_range_test (enum tree_code, tree, tree, tree);
128 static tree fold_cond_expr_with_comparison (tree, tree, tree, tree);
129 static tree unextend (tree, int, int, tree);
130 static tree fold_truthop (enum tree_code, tree, tree, tree);
131 static tree optimize_minmax_comparison (enum tree_code, tree, tree, tree);
132 static tree extract_muldiv (tree, tree, enum tree_code, tree, bool *);
133 static tree extract_muldiv_1 (tree, tree, enum tree_code, tree, bool *);
134 static int multiple_of_p (tree, tree, tree);
135 static tree fold_binary_op_with_conditional_arg (enum tree_code, tree,
138 static bool fold_real_zero_addition_p (tree, tree, int);
139 static tree fold_mathfn_compare (enum built_in_function, enum tree_code,
141 static tree fold_inf_compare (enum tree_code, tree, tree, tree);
142 static tree fold_div_compare (enum tree_code, tree, tree, tree);
143 static bool reorder_operands_p (tree, tree);
144 static tree fold_negate_const (tree, tree);
145 static tree fold_not_const (tree, tree);
146 static tree fold_relational_const (enum tree_code, tree, tree, tree);
147 static int native_encode_expr (tree, unsigned char *, int);
148 static tree native_interpret_expr (tree, unsigned char *, int);
151 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
152 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
153 and SUM1. Then this yields nonzero if overflow occurred during the
156 Overflow occurs if A and B have the same sign, but A and SUM differ in
157 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
159 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
161 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
162 We do that by representing the two-word integer in 4 words, with only
163 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
164 number. The value of the word is LOWPART + HIGHPART * BASE. */
167 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
168 #define HIGHPART(x) \
169 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
170 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
172 /* Unpack a two-word integer into 4 words.
173 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
174 WORDS points to the array of HOST_WIDE_INTs. */
177 encode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT low, HOST_WIDE_INT hi)
179 words[0] = LOWPART (low);
180 words[1] = HIGHPART (low);
181 words[2] = LOWPART (hi);
182 words[3] = HIGHPART (hi);
185 /* Pack an array of 4 words into a two-word integer.
186 WORDS points to the array of words.
187 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
190 decode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT *low,
193 *low = words[0] + words[1] * BASE;
194 *hi = words[2] + words[3] * BASE;
197 /* Force the double-word integer L1, H1 to be within the range of the
198 integer type TYPE. Stores the properly truncated and sign-extended
199 double-word integer in *LV, *HV. Returns true if the operation
200 overflows, that is, argument and result are different. */
203 fit_double_type (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
204 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv, tree type)
206 unsigned HOST_WIDE_INT low0 = l1;
207 HOST_WIDE_INT high0 = h1;
209 int sign_extended_type;
211 if (POINTER_TYPE_P (type)
212 || TREE_CODE (type) == OFFSET_TYPE)
215 prec = TYPE_PRECISION (type);
217 /* Size types *are* sign extended. */
218 sign_extended_type = (!TYPE_UNSIGNED (type)
219 || (TREE_CODE (type) == INTEGER_TYPE
220 && TYPE_IS_SIZETYPE (type)));
222 /* First clear all bits that are beyond the type's precision. */
223 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
225 else if (prec > HOST_BITS_PER_WIDE_INT)
226 h1 &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
230 if (prec < HOST_BITS_PER_WIDE_INT)
231 l1 &= ~((HOST_WIDE_INT) (-1) << prec);
234 /* Then do sign extension if necessary. */
235 if (!sign_extended_type)
236 /* No sign extension */;
237 else if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
238 /* Correct width already. */;
239 else if (prec > HOST_BITS_PER_WIDE_INT)
241 /* Sign extend top half? */
242 if (h1 & ((unsigned HOST_WIDE_INT)1
243 << (prec - HOST_BITS_PER_WIDE_INT - 1)))
244 h1 |= (HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT);
246 else if (prec == HOST_BITS_PER_WIDE_INT)
248 if ((HOST_WIDE_INT)l1 < 0)
253 /* Sign extend bottom half? */
254 if (l1 & ((unsigned HOST_WIDE_INT)1 << (prec - 1)))
257 l1 |= (HOST_WIDE_INT)(-1) << prec;
264 /* If the value didn't fit, signal overflow. */
265 return l1 != low0 || h1 != high0;
268 /* We force the double-int HIGH:LOW to the range of the type TYPE by
269 sign or zero extending it.
270 OVERFLOWABLE indicates if we are interested
271 in overflow of the value, when >0 we are only interested in signed
272 overflow, for <0 we are interested in any overflow. OVERFLOWED
273 indicates whether overflow has already occurred. CONST_OVERFLOWED
274 indicates whether constant overflow has already occurred. We force
275 T's value to be within range of T's type (by setting to 0 or 1 all
276 the bits outside the type's range). We set TREE_OVERFLOWED if,
277 OVERFLOWED is nonzero,
278 or OVERFLOWABLE is >0 and signed overflow occurs
279 or OVERFLOWABLE is <0 and any overflow occurs
280 We return a new tree node for the extended double-int. The node
281 is shared if no overflow flags are set. */
284 force_fit_type_double (tree type, unsigned HOST_WIDE_INT low,
285 HOST_WIDE_INT high, int overflowable,
288 int sign_extended_type;
291 /* Size types *are* sign extended. */
292 sign_extended_type = (!TYPE_UNSIGNED (type)
293 || (TREE_CODE (type) == INTEGER_TYPE
294 && TYPE_IS_SIZETYPE (type)));
296 overflow = fit_double_type (low, high, &low, &high, type);
298 /* If we need to set overflow flags, return a new unshared node. */
299 if (overflowed || overflow)
303 || (overflowable > 0 && sign_extended_type))
305 tree t = make_node (INTEGER_CST);
306 TREE_INT_CST_LOW (t) = low;
307 TREE_INT_CST_HIGH (t) = high;
308 TREE_TYPE (t) = type;
309 TREE_OVERFLOW (t) = 1;
314 /* Else build a shared node. */
315 return build_int_cst_wide (type, low, high);
318 /* Add two doubleword integers with doubleword result.
319 Return nonzero if the operation overflows according to UNSIGNED_P.
320 Each argument is given as two `HOST_WIDE_INT' pieces.
321 One argument is L1 and H1; the other, L2 and H2.
322 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
325 add_double_with_sign (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
326 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
327 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
330 unsigned HOST_WIDE_INT l;
334 h = h1 + h2 + (l < l1);
340 return (unsigned HOST_WIDE_INT) h < (unsigned HOST_WIDE_INT) h1;
342 return OVERFLOW_SUM_SIGN (h1, h2, h);
345 /* Negate a doubleword integer with doubleword result.
346 Return nonzero if the operation overflows, assuming it's signed.
347 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
348 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
351 neg_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
352 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
358 return (*hv & h1) < 0;
368 /* Multiply two doubleword integers with doubleword result.
369 Return nonzero if the operation overflows according to UNSIGNED_P.
370 Each argument is given as two `HOST_WIDE_INT' pieces.
371 One argument is L1 and H1; the other, L2 and H2.
372 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
375 mul_double_with_sign (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
376 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
377 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
380 HOST_WIDE_INT arg1[4];
381 HOST_WIDE_INT arg2[4];
382 HOST_WIDE_INT prod[4 * 2];
383 unsigned HOST_WIDE_INT carry;
385 unsigned HOST_WIDE_INT toplow, neglow;
386 HOST_WIDE_INT tophigh, neghigh;
388 encode (arg1, l1, h1);
389 encode (arg2, l2, h2);
391 memset (prod, 0, sizeof prod);
393 for (i = 0; i < 4; i++)
396 for (j = 0; j < 4; j++)
399 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
400 carry += arg1[i] * arg2[j];
401 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
403 prod[k] = LOWPART (carry);
404 carry = HIGHPART (carry);
409 decode (prod, lv, hv);
410 decode (prod + 4, &toplow, &tophigh);
412 /* Unsigned overflow is immediate. */
414 return (toplow | tophigh) != 0;
416 /* Check for signed overflow by calculating the signed representation of the
417 top half of the result; it should agree with the low half's sign bit. */
420 neg_double (l2, h2, &neglow, &neghigh);
421 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
425 neg_double (l1, h1, &neglow, &neghigh);
426 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
428 return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
431 /* Shift the doubleword integer in L1, H1 left by COUNT places
432 keeping only PREC bits of result.
433 Shift right if COUNT is negative.
434 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
435 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
438 lshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
439 HOST_WIDE_INT count, unsigned int prec,
440 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv, int arith)
442 unsigned HOST_WIDE_INT signmask;
446 rshift_double (l1, h1, -count, prec, lv, hv, arith);
450 if (SHIFT_COUNT_TRUNCATED)
453 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
455 /* Shifting by the host word size is undefined according to the
456 ANSI standard, so we must handle this as a special case. */
460 else if (count >= HOST_BITS_PER_WIDE_INT)
462 *hv = l1 << (count - HOST_BITS_PER_WIDE_INT);
467 *hv = (((unsigned HOST_WIDE_INT) h1 << count)
468 | (l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
472 /* Sign extend all bits that are beyond the precision. */
474 signmask = -((prec > HOST_BITS_PER_WIDE_INT
475 ? ((unsigned HOST_WIDE_INT) *hv
476 >> (prec - HOST_BITS_PER_WIDE_INT - 1))
477 : (*lv >> (prec - 1))) & 1);
479 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
481 else if (prec >= HOST_BITS_PER_WIDE_INT)
483 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
484 *hv |= signmask << (prec - HOST_BITS_PER_WIDE_INT);
489 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
490 *lv |= signmask << prec;
494 /* Shift the doubleword integer in L1, H1 right by COUNT places
495 keeping only PREC bits of result. COUNT must be positive.
496 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
497 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
500 rshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
501 HOST_WIDE_INT count, unsigned int prec,
502 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
505 unsigned HOST_WIDE_INT signmask;
508 ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
511 if (SHIFT_COUNT_TRUNCATED)
514 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
516 /* Shifting by the host word size is undefined according to the
517 ANSI standard, so we must handle this as a special case. */
521 else if (count >= HOST_BITS_PER_WIDE_INT)
524 *lv = (unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT);
528 *hv = (unsigned HOST_WIDE_INT) h1 >> count;
530 | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
533 /* Zero / sign extend all bits that are beyond the precision. */
535 if (count >= (HOST_WIDE_INT)prec)
540 else if ((prec - count) >= 2 * HOST_BITS_PER_WIDE_INT)
542 else if ((prec - count) >= HOST_BITS_PER_WIDE_INT)
544 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - count - HOST_BITS_PER_WIDE_INT));
545 *hv |= signmask << (prec - count - HOST_BITS_PER_WIDE_INT);
550 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << (prec - count));
551 *lv |= signmask << (prec - count);
555 /* Rotate the doubleword integer in L1, H1 left by COUNT places
556 keeping only PREC bits of result.
557 Rotate right if COUNT is negative.
558 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
561 lrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
562 HOST_WIDE_INT count, unsigned int prec,
563 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
565 unsigned HOST_WIDE_INT s1l, s2l;
566 HOST_WIDE_INT s1h, s2h;
572 lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
573 rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
578 /* Rotate the doubleword integer in L1, H1 left by COUNT places
579 keeping only PREC bits of result. COUNT must be positive.
580 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
583 rrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
584 HOST_WIDE_INT count, unsigned int prec,
585 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
587 unsigned HOST_WIDE_INT s1l, s2l;
588 HOST_WIDE_INT s1h, s2h;
594 rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
595 lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
600 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
601 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
602 CODE is a tree code for a kind of division, one of
603 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
605 It controls how the quotient is rounded to an integer.
606 Return nonzero if the operation overflows.
607 UNS nonzero says do unsigned division. */
610 div_and_round_double (enum tree_code code, int uns,
611 unsigned HOST_WIDE_INT lnum_orig, /* num == numerator == dividend */
612 HOST_WIDE_INT hnum_orig,
613 unsigned HOST_WIDE_INT lden_orig, /* den == denominator == divisor */
614 HOST_WIDE_INT hden_orig,
615 unsigned HOST_WIDE_INT *lquo,
616 HOST_WIDE_INT *hquo, unsigned HOST_WIDE_INT *lrem,
620 HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
621 HOST_WIDE_INT den[4], quo[4];
623 unsigned HOST_WIDE_INT work;
624 unsigned HOST_WIDE_INT carry = 0;
625 unsigned HOST_WIDE_INT lnum = lnum_orig;
626 HOST_WIDE_INT hnum = hnum_orig;
627 unsigned HOST_WIDE_INT lden = lden_orig;
628 HOST_WIDE_INT hden = hden_orig;
631 if (hden == 0 && lden == 0)
632 overflow = 1, lden = 1;
634 /* Calculate quotient sign and convert operands to unsigned. */
640 /* (minimum integer) / (-1) is the only overflow case. */
641 if (neg_double (lnum, hnum, &lnum, &hnum)
642 && ((HOST_WIDE_INT) lden & hden) == -1)
648 neg_double (lden, hden, &lden, &hden);
652 if (hnum == 0 && hden == 0)
653 { /* single precision */
655 /* This unsigned division rounds toward zero. */
661 { /* trivial case: dividend < divisor */
662 /* hden != 0 already checked. */
669 memset (quo, 0, sizeof quo);
671 memset (num, 0, sizeof num); /* to zero 9th element */
672 memset (den, 0, sizeof den);
674 encode (num, lnum, hnum);
675 encode (den, lden, hden);
677 /* Special code for when the divisor < BASE. */
678 if (hden == 0 && lden < (unsigned HOST_WIDE_INT) BASE)
680 /* hnum != 0 already checked. */
681 for (i = 4 - 1; i >= 0; i--)
683 work = num[i] + carry * BASE;
684 quo[i] = work / lden;
690 /* Full double precision division,
691 with thanks to Don Knuth's "Seminumerical Algorithms". */
692 int num_hi_sig, den_hi_sig;
693 unsigned HOST_WIDE_INT quo_est, scale;
695 /* Find the highest nonzero divisor digit. */
696 for (i = 4 - 1;; i--)
703 /* Insure that the first digit of the divisor is at least BASE/2.
704 This is required by the quotient digit estimation algorithm. */
706 scale = BASE / (den[den_hi_sig] + 1);
708 { /* scale divisor and dividend */
710 for (i = 0; i <= 4 - 1; i++)
712 work = (num[i] * scale) + carry;
713 num[i] = LOWPART (work);
714 carry = HIGHPART (work);
719 for (i = 0; i <= 4 - 1; i++)
721 work = (den[i] * scale) + carry;
722 den[i] = LOWPART (work);
723 carry = HIGHPART (work);
724 if (den[i] != 0) den_hi_sig = i;
731 for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--)
733 /* Guess the next quotient digit, quo_est, by dividing the first
734 two remaining dividend digits by the high order quotient digit.
735 quo_est is never low and is at most 2 high. */
736 unsigned HOST_WIDE_INT tmp;
738 num_hi_sig = i + den_hi_sig + 1;
739 work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
740 if (num[num_hi_sig] != den[den_hi_sig])
741 quo_est = work / den[den_hi_sig];
745 /* Refine quo_est so it's usually correct, and at most one high. */
746 tmp = work - quo_est * den[den_hi_sig];
748 && (den[den_hi_sig - 1] * quo_est
749 > (tmp * BASE + num[num_hi_sig - 2])))
752 /* Try QUO_EST as the quotient digit, by multiplying the
753 divisor by QUO_EST and subtracting from the remaining dividend.
754 Keep in mind that QUO_EST is the I - 1st digit. */
757 for (j = 0; j <= den_hi_sig; j++)
759 work = quo_est * den[j] + carry;
760 carry = HIGHPART (work);
761 work = num[i + j] - LOWPART (work);
762 num[i + j] = LOWPART (work);
763 carry += HIGHPART (work) != 0;
766 /* If quo_est was high by one, then num[i] went negative and
767 we need to correct things. */
768 if (num[num_hi_sig] < (HOST_WIDE_INT) carry)
771 carry = 0; /* add divisor back in */
772 for (j = 0; j <= den_hi_sig; j++)
774 work = num[i + j] + den[j] + carry;
775 carry = HIGHPART (work);
776 num[i + j] = LOWPART (work);
779 num [num_hi_sig] += carry;
782 /* Store the quotient digit. */
787 decode (quo, lquo, hquo);
790 /* If result is negative, make it so. */
792 neg_double (*lquo, *hquo, lquo, hquo);
794 /* Compute trial remainder: rem = num - (quo * den) */
795 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
796 neg_double (*lrem, *hrem, lrem, hrem);
797 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
802 case TRUNC_MOD_EXPR: /* round toward zero */
803 case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
807 case FLOOR_MOD_EXPR: /* round toward negative infinity */
808 if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
811 add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
819 case CEIL_MOD_EXPR: /* round toward positive infinity */
820 if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
822 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
830 case ROUND_MOD_EXPR: /* round to closest integer */
832 unsigned HOST_WIDE_INT labs_rem = *lrem;
833 HOST_WIDE_INT habs_rem = *hrem;
834 unsigned HOST_WIDE_INT labs_den = lden, ltwice;
835 HOST_WIDE_INT habs_den = hden, htwice;
837 /* Get absolute values. */
839 neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
841 neg_double (lden, hden, &labs_den, &habs_den);
843 /* If (2 * abs (lrem) >= abs (lden)) */
844 mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
845 labs_rem, habs_rem, <wice, &htwice);
847 if (((unsigned HOST_WIDE_INT) habs_den
848 < (unsigned HOST_WIDE_INT) htwice)
849 || (((unsigned HOST_WIDE_INT) habs_den
850 == (unsigned HOST_WIDE_INT) htwice)
851 && (labs_den < ltwice)))
855 add_double (*lquo, *hquo,
856 (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
859 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
871 /* Compute true remainder: rem = num - (quo * den) */
872 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
873 neg_double (*lrem, *hrem, lrem, hrem);
874 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
878 /* If ARG2 divides ARG1 with zero remainder, carries out the division
879 of type CODE and returns the quotient.
880 Otherwise returns NULL_TREE. */
883 div_if_zero_remainder (enum tree_code code, tree arg1, tree arg2)
885 unsigned HOST_WIDE_INT int1l, int2l;
886 HOST_WIDE_INT int1h, int2h;
887 unsigned HOST_WIDE_INT quol, reml;
888 HOST_WIDE_INT quoh, remh;
889 tree type = TREE_TYPE (arg1);
890 int uns = TYPE_UNSIGNED (type);
892 int1l = TREE_INT_CST_LOW (arg1);
893 int1h = TREE_INT_CST_HIGH (arg1);
894 int2l = TREE_INT_CST_LOW (arg2);
895 int2h = TREE_INT_CST_HIGH (arg2);
897 div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
898 &quol, &quoh, &reml, &remh);
899 if (remh != 0 || reml != 0)
902 return build_int_cst_wide (type, quol, quoh);
905 /* This is non-zero if we should defer warnings about undefined
906 overflow. This facility exists because these warnings are a
907 special case. The code to estimate loop iterations does not want
908 to issue any warnings, since it works with expressions which do not
909 occur in user code. Various bits of cleanup code call fold(), but
910 only use the result if it has certain characteristics (e.g., is a
911 constant); that code only wants to issue a warning if the result is
914 static int fold_deferring_overflow_warnings;
916 /* If a warning about undefined overflow is deferred, this is the
917 warning. Note that this may cause us to turn two warnings into
918 one, but that is fine since it is sufficient to only give one
919 warning per expression. */
921 static const char* fold_deferred_overflow_warning;
923 /* If a warning about undefined overflow is deferred, this is the
924 level at which the warning should be emitted. */
926 static enum warn_strict_overflow_code fold_deferred_overflow_code;
928 /* Start deferring overflow warnings. We could use a stack here to
929 permit nested calls, but at present it is not necessary. */
932 fold_defer_overflow_warnings (void)
934 ++fold_deferring_overflow_warnings;
937 /* Stop deferring overflow warnings. If there is a pending warning,
938 and ISSUE is true, then issue the warning if appropriate. STMT is
939 the statement with which the warning should be associated (used for
940 location information); STMT may be NULL. CODE is the level of the
941 warning--a warn_strict_overflow_code value. This function will use
942 the smaller of CODE and the deferred code when deciding whether to
943 issue the warning. CODE may be zero to mean to always use the
947 fold_undefer_overflow_warnings (bool issue, tree stmt, int code)
952 gcc_assert (fold_deferring_overflow_warnings > 0);
953 --fold_deferring_overflow_warnings;
954 if (fold_deferring_overflow_warnings > 0)
956 if (fold_deferred_overflow_warning != NULL
958 && code < (int) fold_deferred_overflow_code)
959 fold_deferred_overflow_code = code;
963 warnmsg = fold_deferred_overflow_warning;
964 fold_deferred_overflow_warning = NULL;
966 if (!issue || warnmsg == NULL)
969 /* Use the smallest code level when deciding to issue the
971 if (code == 0 || code > (int) fold_deferred_overflow_code)
972 code = fold_deferred_overflow_code;
974 if (!issue_strict_overflow_warning (code))
977 if (stmt == NULL_TREE || !expr_has_location (stmt))
978 locus = input_location;
980 locus = expr_location (stmt);
981 warning (OPT_Wstrict_overflow, "%H%s", &locus, warnmsg);
984 /* Stop deferring overflow warnings, ignoring any deferred
988 fold_undefer_and_ignore_overflow_warnings (void)
990 fold_undefer_overflow_warnings (false, NULL_TREE, 0);
993 /* Whether we are deferring overflow warnings. */
996 fold_deferring_overflow_warnings_p (void)
998 return fold_deferring_overflow_warnings > 0;
1001 /* This is called when we fold something based on the fact that signed
1002 overflow is undefined. */
1005 fold_overflow_warning (const char* gmsgid, enum warn_strict_overflow_code wc)
1007 gcc_assert (!flag_wrapv && !flag_trapv);
1008 if (fold_deferring_overflow_warnings > 0)
1010 if (fold_deferred_overflow_warning == NULL
1011 || wc < fold_deferred_overflow_code)
1013 fold_deferred_overflow_warning = gmsgid;
1014 fold_deferred_overflow_code = wc;
1017 else if (issue_strict_overflow_warning (wc))
1018 warning (OPT_Wstrict_overflow, gmsgid);
1021 /* Return true if the built-in mathematical function specified by CODE
1022 is odd, i.e. -f(x) == f(-x). */
1025 negate_mathfn_p (enum built_in_function code)
1029 CASE_FLT_FN (BUILT_IN_ASIN):
1030 CASE_FLT_FN (BUILT_IN_ASINH):
1031 CASE_FLT_FN (BUILT_IN_ATAN):
1032 CASE_FLT_FN (BUILT_IN_ATANH):
1033 CASE_FLT_FN (BUILT_IN_CASIN):
1034 CASE_FLT_FN (BUILT_IN_CASINH):
1035 CASE_FLT_FN (BUILT_IN_CATAN):
1036 CASE_FLT_FN (BUILT_IN_CATANH):
1037 CASE_FLT_FN (BUILT_IN_CBRT):
1038 CASE_FLT_FN (BUILT_IN_CPROJ):
1039 CASE_FLT_FN (BUILT_IN_CSIN):
1040 CASE_FLT_FN (BUILT_IN_CSINH):
1041 CASE_FLT_FN (BUILT_IN_CTAN):
1042 CASE_FLT_FN (BUILT_IN_CTANH):
1043 CASE_FLT_FN (BUILT_IN_ERF):
1044 CASE_FLT_FN (BUILT_IN_LLROUND):
1045 CASE_FLT_FN (BUILT_IN_LROUND):
1046 CASE_FLT_FN (BUILT_IN_ROUND):
1047 CASE_FLT_FN (BUILT_IN_SIN):
1048 CASE_FLT_FN (BUILT_IN_SINH):
1049 CASE_FLT_FN (BUILT_IN_TAN):
1050 CASE_FLT_FN (BUILT_IN_TANH):
1051 CASE_FLT_FN (BUILT_IN_TRUNC):
1054 CASE_FLT_FN (BUILT_IN_LLRINT):
1055 CASE_FLT_FN (BUILT_IN_LRINT):
1056 CASE_FLT_FN (BUILT_IN_NEARBYINT):
1057 CASE_FLT_FN (BUILT_IN_RINT):
1058 return !flag_rounding_math;
1066 /* Check whether we may negate an integer constant T without causing
1070 may_negate_without_overflow_p (tree t)
1072 unsigned HOST_WIDE_INT val;
1076 gcc_assert (TREE_CODE (t) == INTEGER_CST);
1078 type = TREE_TYPE (t);
1079 if (TYPE_UNSIGNED (type))
1082 prec = TYPE_PRECISION (type);
1083 if (prec > HOST_BITS_PER_WIDE_INT)
1085 if (TREE_INT_CST_LOW (t) != 0)
1087 prec -= HOST_BITS_PER_WIDE_INT;
1088 val = TREE_INT_CST_HIGH (t);
1091 val = TREE_INT_CST_LOW (t);
1092 if (prec < HOST_BITS_PER_WIDE_INT)
1093 val &= ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
1094 return val != ((unsigned HOST_WIDE_INT) 1 << (prec - 1));
1097 /* Determine whether an expression T can be cheaply negated using
1098 the function negate_expr without introducing undefined overflow. */
1101 negate_expr_p (tree t)
1108 type = TREE_TYPE (t);
1110 STRIP_SIGN_NOPS (t);
1111 switch (TREE_CODE (t))
1114 if (TYPE_OVERFLOW_WRAPS (type))
1117 /* Check that -CST will not overflow type. */
1118 return may_negate_without_overflow_p (t);
1120 return (INTEGRAL_TYPE_P (type)
1121 && TYPE_OVERFLOW_WRAPS (type));
1128 return negate_expr_p (TREE_REALPART (t))
1129 && negate_expr_p (TREE_IMAGPART (t));
1132 return negate_expr_p (TREE_OPERAND (t, 0))
1133 && negate_expr_p (TREE_OPERAND (t, 1));
1136 return negate_expr_p (TREE_OPERAND (t, 0));
1139 if (HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1140 || HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
1142 /* -(A + B) -> (-B) - A. */
1143 if (negate_expr_p (TREE_OPERAND (t, 1))
1144 && reorder_operands_p (TREE_OPERAND (t, 0),
1145 TREE_OPERAND (t, 1)))
1147 /* -(A + B) -> (-A) - B. */
1148 return negate_expr_p (TREE_OPERAND (t, 0));
1151 /* We can't turn -(A-B) into B-A when we honor signed zeros. */
1152 return !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1153 && !HONOR_SIGNED_ZEROS (TYPE_MODE (type))
1154 && reorder_operands_p (TREE_OPERAND (t, 0),
1155 TREE_OPERAND (t, 1));
1158 if (TYPE_UNSIGNED (TREE_TYPE (t)))
1164 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
1165 return negate_expr_p (TREE_OPERAND (t, 1))
1166 || negate_expr_p (TREE_OPERAND (t, 0));
1169 case TRUNC_DIV_EXPR:
1170 case ROUND_DIV_EXPR:
1171 case FLOOR_DIV_EXPR:
1173 case EXACT_DIV_EXPR:
1174 /* In general we can't negate A / B, because if A is INT_MIN and
1175 B is 1, we may turn this into INT_MIN / -1 which is undefined
1176 and actually traps on some architectures. But if overflow is
1177 undefined, we can negate, because - (INT_MIN / 1) is an
1179 if (INTEGRAL_TYPE_P (TREE_TYPE (t))
1180 && !TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (t)))
1182 return negate_expr_p (TREE_OPERAND (t, 1))
1183 || negate_expr_p (TREE_OPERAND (t, 0));
1186 /* Negate -((double)float) as (double)(-float). */
1187 if (TREE_CODE (type) == REAL_TYPE)
1189 tree tem = strip_float_extensions (t);
1191 return negate_expr_p (tem);
1196 /* Negate -f(x) as f(-x). */
1197 if (negate_mathfn_p (builtin_mathfn_code (t)))
1198 return negate_expr_p (CALL_EXPR_ARG (t, 0));
1202 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1203 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
1205 tree op1 = TREE_OPERAND (t, 1);
1206 if (TREE_INT_CST_HIGH (op1) == 0
1207 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
1208 == TREE_INT_CST_LOW (op1))
1219 /* Given T, an expression, return a folded tree for -T or NULL_TREE, if no
1220 simplification is possible.
1221 If negate_expr_p would return true for T, NULL_TREE will never be
1225 fold_negate_expr (tree t)
1227 tree type = TREE_TYPE (t);
1230 switch (TREE_CODE (t))
1232 /* Convert - (~A) to A + 1. */
1234 if (INTEGRAL_TYPE_P (type))
1235 return fold_build2 (PLUS_EXPR, type, TREE_OPERAND (t, 0),
1236 build_int_cst (type, 1));
1240 tem = fold_negate_const (t, type);
1241 if (TREE_OVERFLOW (tem) == TREE_OVERFLOW (t)
1242 || !TYPE_OVERFLOW_TRAPS (type))
1247 tem = fold_negate_const (t, type);
1248 /* Two's complement FP formats, such as c4x, may overflow. */
1249 if (!TREE_OVERFLOW (tem) || !flag_trapping_math)
1255 tree rpart = negate_expr (TREE_REALPART (t));
1256 tree ipart = negate_expr (TREE_IMAGPART (t));
1258 if ((TREE_CODE (rpart) == REAL_CST
1259 && TREE_CODE (ipart) == REAL_CST)
1260 || (TREE_CODE (rpart) == INTEGER_CST
1261 && TREE_CODE (ipart) == INTEGER_CST))
1262 return build_complex (type, rpart, ipart);
1267 if (negate_expr_p (t))
1268 return fold_build2 (COMPLEX_EXPR, type,
1269 fold_negate_expr (TREE_OPERAND (t, 0)),
1270 fold_negate_expr (TREE_OPERAND (t, 1)));
1274 if (negate_expr_p (t))
1275 return fold_build1 (CONJ_EXPR, type,
1276 fold_negate_expr (TREE_OPERAND (t, 0)));
1280 return TREE_OPERAND (t, 0);
1283 if (!HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1284 && !HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
1286 /* -(A + B) -> (-B) - A. */
1287 if (negate_expr_p (TREE_OPERAND (t, 1))
1288 && reorder_operands_p (TREE_OPERAND (t, 0),
1289 TREE_OPERAND (t, 1)))
1291 tem = negate_expr (TREE_OPERAND (t, 1));
1292 return fold_build2 (MINUS_EXPR, type,
1293 tem, TREE_OPERAND (t, 0));
1296 /* -(A + B) -> (-A) - B. */
1297 if (negate_expr_p (TREE_OPERAND (t, 0)))
1299 tem = negate_expr (TREE_OPERAND (t, 0));
1300 return fold_build2 (MINUS_EXPR, type,
1301 tem, TREE_OPERAND (t, 1));
1307 /* - (A - B) -> B - A */
1308 if (!HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1309 && !HONOR_SIGNED_ZEROS (TYPE_MODE (type))
1310 && reorder_operands_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1)))
1311 return fold_build2 (MINUS_EXPR, type,
1312 TREE_OPERAND (t, 1), TREE_OPERAND (t, 0));
1316 if (TYPE_UNSIGNED (type))
1322 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type)))
1324 tem = TREE_OPERAND (t, 1);
1325 if (negate_expr_p (tem))
1326 return fold_build2 (TREE_CODE (t), type,
1327 TREE_OPERAND (t, 0), negate_expr (tem));
1328 tem = TREE_OPERAND (t, 0);
1329 if (negate_expr_p (tem))
1330 return fold_build2 (TREE_CODE (t), type,
1331 negate_expr (tem), TREE_OPERAND (t, 1));
1335 case TRUNC_DIV_EXPR:
1336 case ROUND_DIV_EXPR:
1337 case FLOOR_DIV_EXPR:
1339 case EXACT_DIV_EXPR:
1340 /* In general we can't negate A / B, because if A is INT_MIN and
1341 B is 1, we may turn this into INT_MIN / -1 which is undefined
1342 and actually traps on some architectures. But if overflow is
1343 undefined, we can negate, because - (INT_MIN / 1) is an
1345 if (!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
1347 const char * const warnmsg = G_("assuming signed overflow does not "
1348 "occur when negating a division");
1349 tem = TREE_OPERAND (t, 1);
1350 if (negate_expr_p (tem))
1352 if (INTEGRAL_TYPE_P (type)
1353 && (TREE_CODE (tem) != INTEGER_CST
1354 || integer_onep (tem)))
1355 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MISC);
1356 return fold_build2 (TREE_CODE (t), type,
1357 TREE_OPERAND (t, 0), negate_expr (tem));
1359 tem = TREE_OPERAND (t, 0);
1360 if (negate_expr_p (tem))
1362 if (INTEGRAL_TYPE_P (type)
1363 && (TREE_CODE (tem) != INTEGER_CST
1364 || tree_int_cst_equal (tem, TYPE_MIN_VALUE (type))))
1365 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MISC);
1366 return fold_build2 (TREE_CODE (t), type,
1367 negate_expr (tem), TREE_OPERAND (t, 1));
1373 /* Convert -((double)float) into (double)(-float). */
1374 if (TREE_CODE (type) == REAL_TYPE)
1376 tem = strip_float_extensions (t);
1377 if (tem != t && negate_expr_p (tem))
1378 return negate_expr (tem);
1383 /* Negate -f(x) as f(-x). */
1384 if (negate_mathfn_p (builtin_mathfn_code (t))
1385 && negate_expr_p (CALL_EXPR_ARG (t, 0)))
1389 fndecl = get_callee_fndecl (t);
1390 arg = negate_expr (CALL_EXPR_ARG (t, 0));
1391 return build_call_expr (fndecl, 1, arg);
1396 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1397 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
1399 tree op1 = TREE_OPERAND (t, 1);
1400 if (TREE_INT_CST_HIGH (op1) == 0
1401 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
1402 == TREE_INT_CST_LOW (op1))
1404 tree ntype = TYPE_UNSIGNED (type)
1405 ? lang_hooks.types.signed_type (type)
1406 : lang_hooks.types.unsigned_type (type);
1407 tree temp = fold_convert (ntype, TREE_OPERAND (t, 0));
1408 temp = fold_build2 (RSHIFT_EXPR, ntype, temp, op1);
1409 return fold_convert (type, temp);
1421 /* Like fold_negate_expr, but return a NEGATE_EXPR tree, if T can not be
1422 negated in a simpler way. Also allow for T to be NULL_TREE, in which case
1423 return NULL_TREE. */
1426 negate_expr (tree t)
1433 type = TREE_TYPE (t);
1434 STRIP_SIGN_NOPS (t);
1436 tem = fold_negate_expr (t);
1438 tem = build1 (NEGATE_EXPR, TREE_TYPE (t), t);
1439 return fold_convert (type, tem);
1442 /* Split a tree IN into a constant, literal and variable parts that could be
1443 combined with CODE to make IN. "constant" means an expression with
1444 TREE_CONSTANT but that isn't an actual constant. CODE must be a
1445 commutative arithmetic operation. Store the constant part into *CONP,
1446 the literal in *LITP and return the variable part. If a part isn't
1447 present, set it to null. If the tree does not decompose in this way,
1448 return the entire tree as the variable part and the other parts as null.
1450 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
1451 case, we negate an operand that was subtracted. Except if it is a
1452 literal for which we use *MINUS_LITP instead.
1454 If NEGATE_P is true, we are negating all of IN, again except a literal
1455 for which we use *MINUS_LITP instead.
1457 If IN is itself a literal or constant, return it as appropriate.
1459 Note that we do not guarantee that any of the three values will be the
1460 same type as IN, but they will have the same signedness and mode. */
1463 split_tree (tree in, enum tree_code code, tree *conp, tree *litp,
1464 tree *minus_litp, int negate_p)
1472 /* Strip any conversions that don't change the machine mode or signedness. */
1473 STRIP_SIGN_NOPS (in);
1475 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST)
1477 else if (TREE_CODE (in) == code
1478 || (! FLOAT_TYPE_P (TREE_TYPE (in))
1479 /* We can associate addition and subtraction together (even
1480 though the C standard doesn't say so) for integers because
1481 the value is not affected. For reals, the value might be
1482 affected, so we can't. */
1483 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
1484 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
1486 tree op0 = TREE_OPERAND (in, 0);
1487 tree op1 = TREE_OPERAND (in, 1);
1488 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
1489 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
1491 /* First see if either of the operands is a literal, then a constant. */
1492 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
1493 *litp = op0, op0 = 0;
1494 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST)
1495 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
1497 if (op0 != 0 && TREE_CONSTANT (op0))
1498 *conp = op0, op0 = 0;
1499 else if (op1 != 0 && TREE_CONSTANT (op1))
1500 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
1502 /* If we haven't dealt with either operand, this is not a case we can
1503 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1504 if (op0 != 0 && op1 != 0)
1509 var = op1, neg_var_p = neg1_p;
1511 /* Now do any needed negations. */
1513 *minus_litp = *litp, *litp = 0;
1515 *conp = negate_expr (*conp);
1517 var = negate_expr (var);
1519 else if (TREE_CONSTANT (in))
1527 *minus_litp = *litp, *litp = 0;
1528 else if (*minus_litp)
1529 *litp = *minus_litp, *minus_litp = 0;
1530 *conp = negate_expr (*conp);
1531 var = negate_expr (var);
1537 /* Re-associate trees split by the above function. T1 and T2 are either
1538 expressions to associate or null. Return the new expression, if any. If
1539 we build an operation, do it in TYPE and with CODE. */
1542 associate_trees (tree t1, tree t2, enum tree_code code, tree type)
1549 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1550 try to fold this since we will have infinite recursion. But do
1551 deal with any NEGATE_EXPRs. */
1552 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
1553 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1555 if (code == PLUS_EXPR)
1557 if (TREE_CODE (t1) == NEGATE_EXPR)
1558 return build2 (MINUS_EXPR, type, fold_convert (type, t2),
1559 fold_convert (type, TREE_OPERAND (t1, 0)));
1560 else if (TREE_CODE (t2) == NEGATE_EXPR)
1561 return build2 (MINUS_EXPR, type, fold_convert (type, t1),
1562 fold_convert (type, TREE_OPERAND (t2, 0)));
1563 else if (integer_zerop (t2))
1564 return fold_convert (type, t1);
1566 else if (code == MINUS_EXPR)
1568 if (integer_zerop (t2))
1569 return fold_convert (type, t1);
1572 return build2 (code, type, fold_convert (type, t1),
1573 fold_convert (type, t2));
1576 return fold_build2 (code, type, fold_convert (type, t1),
1577 fold_convert (type, t2));
1580 /* Check whether TYPE1 and TYPE2 are equivalent integer types, suitable
1581 for use in int_const_binop, size_binop and size_diffop. */
1584 int_binop_types_match_p (enum tree_code code, tree type1, tree type2)
1586 if (TREE_CODE (type1) != INTEGER_TYPE && !POINTER_TYPE_P (type1))
1588 if (TREE_CODE (type2) != INTEGER_TYPE && !POINTER_TYPE_P (type2))
1603 return TYPE_UNSIGNED (type1) == TYPE_UNSIGNED (type2)
1604 && TYPE_PRECISION (type1) == TYPE_PRECISION (type2)
1605 && TYPE_MODE (type1) == TYPE_MODE (type2);
1609 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1610 to produce a new constant. Return NULL_TREE if we don't know how
1611 to evaluate CODE at compile-time.
1613 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1616 int_const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1618 unsigned HOST_WIDE_INT int1l, int2l;
1619 HOST_WIDE_INT int1h, int2h;
1620 unsigned HOST_WIDE_INT low;
1622 unsigned HOST_WIDE_INT garbagel;
1623 HOST_WIDE_INT garbageh;
1625 tree type = TREE_TYPE (arg1);
1626 int uns = TYPE_UNSIGNED (type);
1628 = (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type));
1631 int1l = TREE_INT_CST_LOW (arg1);
1632 int1h = TREE_INT_CST_HIGH (arg1);
1633 int2l = TREE_INT_CST_LOW (arg2);
1634 int2h = TREE_INT_CST_HIGH (arg2);
1639 low = int1l | int2l, hi = int1h | int2h;
1643 low = int1l ^ int2l, hi = int1h ^ int2h;
1647 low = int1l & int2l, hi = int1h & int2h;
1653 /* It's unclear from the C standard whether shifts can overflow.
1654 The following code ignores overflow; perhaps a C standard
1655 interpretation ruling is needed. */
1656 lshift_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1663 lrotate_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1668 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1672 neg_double (int2l, int2h, &low, &hi);
1673 add_double (int1l, int1h, low, hi, &low, &hi);
1674 overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
1678 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1681 case TRUNC_DIV_EXPR:
1682 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1683 case EXACT_DIV_EXPR:
1684 /* This is a shortcut for a common special case. */
1685 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1686 && !TREE_OVERFLOW (arg1)
1687 && !TREE_OVERFLOW (arg2)
1688 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1690 if (code == CEIL_DIV_EXPR)
1693 low = int1l / int2l, hi = 0;
1697 /* ... fall through ... */
1699 case ROUND_DIV_EXPR:
1700 if (int2h == 0 && int2l == 0)
1702 if (int2h == 0 && int2l == 1)
1704 low = int1l, hi = int1h;
1707 if (int1l == int2l && int1h == int2h
1708 && ! (int1l == 0 && int1h == 0))
1713 overflow = div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
1714 &low, &hi, &garbagel, &garbageh);
1717 case TRUNC_MOD_EXPR:
1718 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1719 /* This is a shortcut for a common special case. */
1720 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1721 && !TREE_OVERFLOW (arg1)
1722 && !TREE_OVERFLOW (arg2)
1723 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1725 if (code == CEIL_MOD_EXPR)
1727 low = int1l % int2l, hi = 0;
1731 /* ... fall through ... */
1733 case ROUND_MOD_EXPR:
1734 if (int2h == 0 && int2l == 0)
1736 overflow = div_and_round_double (code, uns,
1737 int1l, int1h, int2l, int2h,
1738 &garbagel, &garbageh, &low, &hi);
1744 low = (((unsigned HOST_WIDE_INT) int1h
1745 < (unsigned HOST_WIDE_INT) int2h)
1746 || (((unsigned HOST_WIDE_INT) int1h
1747 == (unsigned HOST_WIDE_INT) int2h)
1750 low = (int1h < int2h
1751 || (int1h == int2h && int1l < int2l));
1753 if (low == (code == MIN_EXPR))
1754 low = int1l, hi = int1h;
1756 low = int2l, hi = int2h;
1765 t = build_int_cst_wide (TREE_TYPE (arg1), low, hi);
1767 /* Propagate overflow flags ourselves. */
1768 if (((!uns || is_sizetype) && overflow)
1769 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2))
1772 TREE_OVERFLOW (t) = 1;
1776 t = force_fit_type_double (TREE_TYPE (arg1), low, hi, 1,
1777 ((!uns || is_sizetype) && overflow)
1778 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
1783 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1784 constant. We assume ARG1 and ARG2 have the same data type, or at least
1785 are the same kind of constant and the same machine mode. Return zero if
1786 combining the constants is not allowed in the current operating mode.
1788 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1791 const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1793 /* Sanity check for the recursive cases. */
1800 if (TREE_CODE (arg1) == INTEGER_CST)
1801 return int_const_binop (code, arg1, arg2, notrunc);
1803 if (TREE_CODE (arg1) == REAL_CST)
1805 enum machine_mode mode;
1808 REAL_VALUE_TYPE value;
1809 REAL_VALUE_TYPE result;
1813 /* The following codes are handled by real_arithmetic. */
1828 d1 = TREE_REAL_CST (arg1);
1829 d2 = TREE_REAL_CST (arg2);
1831 type = TREE_TYPE (arg1);
1832 mode = TYPE_MODE (type);
1834 /* Don't perform operation if we honor signaling NaNs and
1835 either operand is a NaN. */
1836 if (HONOR_SNANS (mode)
1837 && (REAL_VALUE_ISNAN (d1) || REAL_VALUE_ISNAN (d2)))
1840 /* Don't perform operation if it would raise a division
1841 by zero exception. */
1842 if (code == RDIV_EXPR
1843 && REAL_VALUES_EQUAL (d2, dconst0)
1844 && (flag_trapping_math || ! MODE_HAS_INFINITIES (mode)))
1847 /* If either operand is a NaN, just return it. Otherwise, set up
1848 for floating-point trap; we return an overflow. */
1849 if (REAL_VALUE_ISNAN (d1))
1851 else if (REAL_VALUE_ISNAN (d2))
1854 inexact = real_arithmetic (&value, code, &d1, &d2);
1855 real_convert (&result, mode, &value);
1857 /* Don't constant fold this floating point operation if
1858 the result has overflowed and flag_trapping_math. */
1859 if (flag_trapping_math
1860 && MODE_HAS_INFINITIES (mode)
1861 && REAL_VALUE_ISINF (result)
1862 && !REAL_VALUE_ISINF (d1)
1863 && !REAL_VALUE_ISINF (d2))
1866 /* Don't constant fold this floating point operation if the
1867 result may dependent upon the run-time rounding mode and
1868 flag_rounding_math is set, or if GCC's software emulation
1869 is unable to accurately represent the result. */
1870 if ((flag_rounding_math
1871 || (REAL_MODE_FORMAT_COMPOSITE_P (mode)
1872 && !flag_unsafe_math_optimizations))
1873 && (inexact || !real_identical (&result, &value)))
1876 t = build_real (type, result);
1878 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2);
1882 if (TREE_CODE (arg1) == COMPLEX_CST)
1884 tree type = TREE_TYPE (arg1);
1885 tree r1 = TREE_REALPART (arg1);
1886 tree i1 = TREE_IMAGPART (arg1);
1887 tree r2 = TREE_REALPART (arg2);
1888 tree i2 = TREE_IMAGPART (arg2);
1895 real = const_binop (code, r1, r2, notrunc);
1896 imag = const_binop (code, i1, i2, notrunc);
1900 real = const_binop (MINUS_EXPR,
1901 const_binop (MULT_EXPR, r1, r2, notrunc),
1902 const_binop (MULT_EXPR, i1, i2, notrunc),
1904 imag = const_binop (PLUS_EXPR,
1905 const_binop (MULT_EXPR, r1, i2, notrunc),
1906 const_binop (MULT_EXPR, i1, r2, notrunc),
1913 = const_binop (PLUS_EXPR,
1914 const_binop (MULT_EXPR, r2, r2, notrunc),
1915 const_binop (MULT_EXPR, i2, i2, notrunc),
1918 = const_binop (PLUS_EXPR,
1919 const_binop (MULT_EXPR, r1, r2, notrunc),
1920 const_binop (MULT_EXPR, i1, i2, notrunc),
1923 = const_binop (MINUS_EXPR,
1924 const_binop (MULT_EXPR, i1, r2, notrunc),
1925 const_binop (MULT_EXPR, r1, i2, notrunc),
1928 if (INTEGRAL_TYPE_P (TREE_TYPE (r1)))
1929 code = TRUNC_DIV_EXPR;
1931 real = const_binop (code, t1, magsquared, notrunc);
1932 imag = const_binop (code, t2, magsquared, notrunc);
1941 return build_complex (type, real, imag);
1947 /* Create a size type INT_CST node with NUMBER sign extended. KIND
1948 indicates which particular sizetype to create. */
1951 size_int_kind (HOST_WIDE_INT number, enum size_type_kind kind)
1953 return build_int_cst (sizetype_tab[(int) kind], number);
1956 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1957 is a tree code. The type of the result is taken from the operands.
1958 Both must be equivalent integer types, ala int_binop_types_match_p.
1959 If the operands are constant, so is the result. */
1962 size_binop (enum tree_code code, tree arg0, tree arg1)
1964 tree type = TREE_TYPE (arg0);
1966 if (arg0 == error_mark_node || arg1 == error_mark_node)
1967 return error_mark_node;
1969 gcc_assert (int_binop_types_match_p (code, TREE_TYPE (arg0),
1972 /* Handle the special case of two integer constants faster. */
1973 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1975 /* And some specific cases even faster than that. */
1976 if (code == PLUS_EXPR)
1978 if (integer_zerop (arg0) && !TREE_OVERFLOW (arg0))
1980 if (integer_zerop (arg1) && !TREE_OVERFLOW (arg1))
1983 else if (code == MINUS_EXPR)
1985 if (integer_zerop (arg1) && !TREE_OVERFLOW (arg1))
1988 else if (code == MULT_EXPR)
1990 if (integer_onep (arg0) && !TREE_OVERFLOW (arg0))
1994 /* Handle general case of two integer constants. */
1995 return int_const_binop (code, arg0, arg1, 0);
1998 return fold_build2 (code, type, arg0, arg1);
2001 /* Given two values, either both of sizetype or both of bitsizetype,
2002 compute the difference between the two values. Return the value
2003 in signed type corresponding to the type of the operands. */
2006 size_diffop (tree arg0, tree arg1)
2008 tree type = TREE_TYPE (arg0);
2011 gcc_assert (int_binop_types_match_p (MINUS_EXPR, TREE_TYPE (arg0),
2014 /* If the type is already signed, just do the simple thing. */
2015 if (!TYPE_UNSIGNED (type))
2016 return size_binop (MINUS_EXPR, arg0, arg1);
2018 if (type == sizetype)
2020 else if (type == bitsizetype)
2021 ctype = sbitsizetype;
2023 ctype = lang_hooks.types.signed_type (type);
2025 /* If either operand is not a constant, do the conversions to the signed
2026 type and subtract. The hardware will do the right thing with any
2027 overflow in the subtraction. */
2028 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
2029 return size_binop (MINUS_EXPR, fold_convert (ctype, arg0),
2030 fold_convert (ctype, arg1));
2032 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
2033 Otherwise, subtract the other way, convert to CTYPE (we know that can't
2034 overflow) and negate (which can't either). Special-case a result
2035 of zero while we're here. */
2036 if (tree_int_cst_equal (arg0, arg1))
2037 return build_int_cst (ctype, 0);
2038 else if (tree_int_cst_lt (arg1, arg0))
2039 return fold_convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
2041 return size_binop (MINUS_EXPR, build_int_cst (ctype, 0),
2042 fold_convert (ctype, size_binop (MINUS_EXPR,
2046 /* A subroutine of fold_convert_const handling conversions of an
2047 INTEGER_CST to another integer type. */
2050 fold_convert_const_int_from_int (tree type, tree arg1)
2054 /* Given an integer constant, make new constant with new type,
2055 appropriately sign-extended or truncated. */
2056 t = force_fit_type_double (type, TREE_INT_CST_LOW (arg1),
2057 TREE_INT_CST_HIGH (arg1),
2058 /* Don't set the overflow when
2059 converting a pointer */
2060 !POINTER_TYPE_P (TREE_TYPE (arg1)),
2061 (TREE_INT_CST_HIGH (arg1) < 0
2062 && (TYPE_UNSIGNED (type)
2063 < TYPE_UNSIGNED (TREE_TYPE (arg1))))
2064 | TREE_OVERFLOW (arg1));
2069 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2070 to an integer type. */
2073 fold_convert_const_int_from_real (enum tree_code code, tree type, tree arg1)
2078 /* The following code implements the floating point to integer
2079 conversion rules required by the Java Language Specification,
2080 that IEEE NaNs are mapped to zero and values that overflow
2081 the target precision saturate, i.e. values greater than
2082 INT_MAX are mapped to INT_MAX, and values less than INT_MIN
2083 are mapped to INT_MIN. These semantics are allowed by the
2084 C and C++ standards that simply state that the behavior of
2085 FP-to-integer conversion is unspecified upon overflow. */
2087 HOST_WIDE_INT high, low;
2089 REAL_VALUE_TYPE x = TREE_REAL_CST (arg1);
2093 case FIX_TRUNC_EXPR:
2094 real_trunc (&r, VOIDmode, &x);
2101 /* If R is NaN, return zero and show we have an overflow. */
2102 if (REAL_VALUE_ISNAN (r))
2109 /* See if R is less than the lower bound or greater than the
2114 tree lt = TYPE_MIN_VALUE (type);
2115 REAL_VALUE_TYPE l = real_value_from_int_cst (NULL_TREE, lt);
2116 if (REAL_VALUES_LESS (r, l))
2119 high = TREE_INT_CST_HIGH (lt);
2120 low = TREE_INT_CST_LOW (lt);
2126 tree ut = TYPE_MAX_VALUE (type);
2129 REAL_VALUE_TYPE u = real_value_from_int_cst (NULL_TREE, ut);
2130 if (REAL_VALUES_LESS (u, r))
2133 high = TREE_INT_CST_HIGH (ut);
2134 low = TREE_INT_CST_LOW (ut);
2140 REAL_VALUE_TO_INT (&low, &high, r);
2142 t = force_fit_type_double (type, low, high, -1,
2143 overflow | TREE_OVERFLOW (arg1));
2147 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2148 to another floating point type. */
2151 fold_convert_const_real_from_real (tree type, tree arg1)
2153 REAL_VALUE_TYPE value;
2156 real_convert (&value, TYPE_MODE (type), &TREE_REAL_CST (arg1));
2157 t = build_real (type, value);
2159 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1);
2163 /* Attempt to fold type conversion operation CODE of expression ARG1 to
2164 type TYPE. If no simplification can be done return NULL_TREE. */
2167 fold_convert_const (enum tree_code code, tree type, tree arg1)
2169 if (TREE_TYPE (arg1) == type)
2172 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
2174 if (TREE_CODE (arg1) == INTEGER_CST)
2175 return fold_convert_const_int_from_int (type, arg1);
2176 else if (TREE_CODE (arg1) == REAL_CST)
2177 return fold_convert_const_int_from_real (code, type, arg1);
2179 else if (TREE_CODE (type) == REAL_TYPE)
2181 if (TREE_CODE (arg1) == INTEGER_CST)
2182 return build_real_from_int_cst (type, arg1);
2183 if (TREE_CODE (arg1) == REAL_CST)
2184 return fold_convert_const_real_from_real (type, arg1);
2189 /* Construct a vector of zero elements of vector type TYPE. */
2192 build_zero_vector (tree type)
2197 elem = fold_convert_const (NOP_EXPR, TREE_TYPE (type), integer_zero_node);
2198 units = TYPE_VECTOR_SUBPARTS (type);
2201 for (i = 0; i < units; i++)
2202 list = tree_cons (NULL_TREE, elem, list);
2203 return build_vector (type, list);
2206 /* Convert expression ARG to type TYPE. Used by the middle-end for
2207 simple conversions in preference to calling the front-end's convert. */
2210 fold_convert (tree type, tree arg)
2212 tree orig = TREE_TYPE (arg);
2218 if (TREE_CODE (arg) == ERROR_MARK
2219 || TREE_CODE (type) == ERROR_MARK
2220 || TREE_CODE (orig) == ERROR_MARK)
2221 return error_mark_node;
2223 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig)
2224 || lang_hooks.types_compatible_p (TYPE_MAIN_VARIANT (type),
2225 TYPE_MAIN_VARIANT (orig)))
2226 return fold_build1 (NOP_EXPR, type, arg);
2228 switch (TREE_CODE (type))
2230 case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
2231 case POINTER_TYPE: case REFERENCE_TYPE:
2233 if (TREE_CODE (arg) == INTEGER_CST)
2235 tem = fold_convert_const (NOP_EXPR, type, arg);
2236 if (tem != NULL_TREE)
2239 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
2240 || TREE_CODE (orig) == OFFSET_TYPE)
2241 return fold_build1 (NOP_EXPR, type, arg);
2242 if (TREE_CODE (orig) == COMPLEX_TYPE)
2244 tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2245 return fold_convert (type, tem);
2247 gcc_assert (TREE_CODE (orig) == VECTOR_TYPE
2248 && tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
2249 return fold_build1 (NOP_EXPR, type, arg);
2252 if (TREE_CODE (arg) == INTEGER_CST)
2254 tem = fold_convert_const (FLOAT_EXPR, type, arg);
2255 if (tem != NULL_TREE)
2258 else if (TREE_CODE (arg) == REAL_CST)
2260 tem = fold_convert_const (NOP_EXPR, type, arg);
2261 if (tem != NULL_TREE)
2265 switch (TREE_CODE (orig))
2268 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
2269 case POINTER_TYPE: case REFERENCE_TYPE:
2270 return fold_build1 (FLOAT_EXPR, type, arg);
2273 return fold_build1 (NOP_EXPR, type, arg);
2276 tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2277 return fold_convert (type, tem);
2284 switch (TREE_CODE (orig))
2287 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
2288 case POINTER_TYPE: case REFERENCE_TYPE:
2290 return build2 (COMPLEX_EXPR, type,
2291 fold_convert (TREE_TYPE (type), arg),
2292 fold_convert (TREE_TYPE (type), integer_zero_node));
2297 if (TREE_CODE (arg) == COMPLEX_EXPR)
2299 rpart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 0));
2300 ipart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 1));
2301 return fold_build2 (COMPLEX_EXPR, type, rpart, ipart);
2304 arg = save_expr (arg);
2305 rpart = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2306 ipart = fold_build1 (IMAGPART_EXPR, TREE_TYPE (orig), arg);
2307 rpart = fold_convert (TREE_TYPE (type), rpart);
2308 ipart = fold_convert (TREE_TYPE (type), ipart);
2309 return fold_build2 (COMPLEX_EXPR, type, rpart, ipart);
2317 if (integer_zerop (arg))
2318 return build_zero_vector (type);
2319 gcc_assert (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
2320 gcc_assert (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
2321 || TREE_CODE (orig) == VECTOR_TYPE);
2322 return fold_build1 (VIEW_CONVERT_EXPR, type, arg);
2325 tem = fold_ignored_result (arg);
2326 if (TREE_CODE (tem) == GIMPLE_MODIFY_STMT)
2328 return fold_build1 (NOP_EXPR, type, tem);
2335 /* Return false if expr can be assumed not to be an lvalue, true
2339 maybe_lvalue_p (tree x)
2341 /* We only need to wrap lvalue tree codes. */
2342 switch (TREE_CODE (x))
2353 case ALIGN_INDIRECT_REF:
2354 case MISALIGNED_INDIRECT_REF:
2356 case ARRAY_RANGE_REF:
2362 case PREINCREMENT_EXPR:
2363 case PREDECREMENT_EXPR:
2365 case TRY_CATCH_EXPR:
2366 case WITH_CLEANUP_EXPR:
2369 case GIMPLE_MODIFY_STMT:
2378 /* Assume the worst for front-end tree codes. */
2379 if ((int)TREE_CODE (x) >= NUM_TREE_CODES)
2387 /* Return an expr equal to X but certainly not valid as an lvalue. */
2392 /* While we are in GIMPLE, NON_LVALUE_EXPR doesn't mean anything to
2397 if (! maybe_lvalue_p (x))
2399 return build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
2402 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
2403 Zero means allow extended lvalues. */
2405 int pedantic_lvalues;
2407 /* When pedantic, return an expr equal to X but certainly not valid as a
2408 pedantic lvalue. Otherwise, return X. */
2411 pedantic_non_lvalue (tree x)
2413 if (pedantic_lvalues)
2414 return non_lvalue (x);
2419 /* Given a tree comparison code, return the code that is the logical inverse
2420 of the given code. It is not safe to do this for floating-point
2421 comparisons, except for NE_EXPR and EQ_EXPR, so we receive a machine mode
2422 as well: if reversing the comparison is unsafe, return ERROR_MARK. */
2425 invert_tree_comparison (enum tree_code code, bool honor_nans)
2427 if (honor_nans && flag_trapping_math)
2437 return honor_nans ? UNLE_EXPR : LE_EXPR;
2439 return honor_nans ? UNLT_EXPR : LT_EXPR;
2441 return honor_nans ? UNGE_EXPR : GE_EXPR;
2443 return honor_nans ? UNGT_EXPR : GT_EXPR;
2457 return UNORDERED_EXPR;
2458 case UNORDERED_EXPR:
2459 return ORDERED_EXPR;
2465 /* Similar, but return the comparison that results if the operands are
2466 swapped. This is safe for floating-point. */
2469 swap_tree_comparison (enum tree_code code)
2476 case UNORDERED_EXPR:
2502 /* Convert a comparison tree code from an enum tree_code representation
2503 into a compcode bit-based encoding. This function is the inverse of
2504 compcode_to_comparison. */
2506 static enum comparison_code
2507 comparison_to_compcode (enum tree_code code)
2524 return COMPCODE_ORD;
2525 case UNORDERED_EXPR:
2526 return COMPCODE_UNORD;
2528 return COMPCODE_UNLT;
2530 return COMPCODE_UNEQ;
2532 return COMPCODE_UNLE;
2534 return COMPCODE_UNGT;
2536 return COMPCODE_LTGT;
2538 return COMPCODE_UNGE;
2544 /* Convert a compcode bit-based encoding of a comparison operator back
2545 to GCC's enum tree_code representation. This function is the
2546 inverse of comparison_to_compcode. */
2548 static enum tree_code
2549 compcode_to_comparison (enum comparison_code code)
2566 return ORDERED_EXPR;
2567 case COMPCODE_UNORD:
2568 return UNORDERED_EXPR;
2586 /* Return a tree for the comparison which is the combination of
2587 doing the AND or OR (depending on CODE) of the two operations LCODE
2588 and RCODE on the identical operands LL_ARG and LR_ARG. Take into account
2589 the possibility of trapping if the mode has NaNs, and return NULL_TREE
2590 if this makes the transformation invalid. */
2593 combine_comparisons (enum tree_code code, enum tree_code lcode,
2594 enum tree_code rcode, tree truth_type,
2595 tree ll_arg, tree lr_arg)
2597 bool honor_nans = HONOR_NANS (TYPE_MODE (TREE_TYPE (ll_arg)));
2598 enum comparison_code lcompcode = comparison_to_compcode (lcode);
2599 enum comparison_code rcompcode = comparison_to_compcode (rcode);
2600 enum comparison_code compcode;
2604 case TRUTH_AND_EXPR: case TRUTH_ANDIF_EXPR:
2605 compcode = lcompcode & rcompcode;
2608 case TRUTH_OR_EXPR: case TRUTH_ORIF_EXPR:
2609 compcode = lcompcode | rcompcode;
2618 /* Eliminate unordered comparisons, as well as LTGT and ORD
2619 which are not used unless the mode has NaNs. */
2620 compcode &= ~COMPCODE_UNORD;
2621 if (compcode == COMPCODE_LTGT)
2622 compcode = COMPCODE_NE;
2623 else if (compcode == COMPCODE_ORD)
2624 compcode = COMPCODE_TRUE;
2626 else if (flag_trapping_math)
2628 /* Check that the original operation and the optimized ones will trap
2629 under the same condition. */
2630 bool ltrap = (lcompcode & COMPCODE_UNORD) == 0
2631 && (lcompcode != COMPCODE_EQ)
2632 && (lcompcode != COMPCODE_ORD);
2633 bool rtrap = (rcompcode & COMPCODE_UNORD) == 0
2634 && (rcompcode != COMPCODE_EQ)
2635 && (rcompcode != COMPCODE_ORD);
2636 bool trap = (compcode & COMPCODE_UNORD) == 0
2637 && (compcode != COMPCODE_EQ)
2638 && (compcode != COMPCODE_ORD);
2640 /* In a short-circuited boolean expression the LHS might be
2641 such that the RHS, if evaluated, will never trap. For
2642 example, in ORD (x, y) && (x < y), we evaluate the RHS only
2643 if neither x nor y is NaN. (This is a mixed blessing: for
2644 example, the expression above will never trap, hence
2645 optimizing it to x < y would be invalid). */
2646 if ((code == TRUTH_ORIF_EXPR && (lcompcode & COMPCODE_UNORD))
2647 || (code == TRUTH_ANDIF_EXPR && !(lcompcode & COMPCODE_UNORD)))
2650 /* If the comparison was short-circuited, and only the RHS
2651 trapped, we may now generate a spurious trap. */
2653 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2656 /* If we changed the conditions that cause a trap, we lose. */
2657 if ((ltrap || rtrap) != trap)
2661 if (compcode == COMPCODE_TRUE)
2662 return constant_boolean_node (true, truth_type);
2663 else if (compcode == COMPCODE_FALSE)
2664 return constant_boolean_node (false, truth_type);
2666 return fold_build2 (compcode_to_comparison (compcode),
2667 truth_type, ll_arg, lr_arg);
2670 /* Return nonzero if CODE is a tree code that represents a truth value. */
2673 truth_value_p (enum tree_code code)
2675 return (TREE_CODE_CLASS (code) == tcc_comparison
2676 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2677 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2678 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
2681 /* Return nonzero if two operands (typically of the same tree node)
2682 are necessarily equal. If either argument has side-effects this
2683 function returns zero. FLAGS modifies behavior as follows:
2685 If OEP_ONLY_CONST is set, only return nonzero for constants.
2686 This function tests whether the operands are indistinguishable;
2687 it does not test whether they are equal using C's == operation.
2688 The distinction is important for IEEE floating point, because
2689 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2690 (2) two NaNs may be indistinguishable, but NaN!=NaN.
2692 If OEP_ONLY_CONST is unset, a VAR_DECL is considered equal to itself
2693 even though it may hold multiple values during a function.
2694 This is because a GCC tree node guarantees that nothing else is
2695 executed between the evaluation of its "operands" (which may often
2696 be evaluated in arbitrary order). Hence if the operands themselves
2697 don't side-effect, the VAR_DECLs, PARM_DECLs etc... must hold the
2698 same value in each operand/subexpression. Hence leaving OEP_ONLY_CONST
2699 unset means assuming isochronic (or instantaneous) tree equivalence.
2700 Unless comparing arbitrary expression trees, such as from different
2701 statements, this flag can usually be left unset.
2703 If OEP_PURE_SAME is set, then pure functions with identical arguments
2704 are considered the same. It is used when the caller has other ways
2705 to ensure that global memory is unchanged in between. */
2708 operand_equal_p (tree arg0, tree arg1, unsigned int flags)
2710 /* If either is ERROR_MARK, they aren't equal. */
2711 if (TREE_CODE (arg0) == ERROR_MARK || TREE_CODE (arg1) == ERROR_MARK)
2714 /* If both types don't have the same signedness, then we can't consider
2715 them equal. We must check this before the STRIP_NOPS calls
2716 because they may change the signedness of the arguments. */
2717 if (TYPE_UNSIGNED (TREE_TYPE (arg0)) != TYPE_UNSIGNED (TREE_TYPE (arg1)))
2720 /* If both types don't have the same precision, then it is not safe
2722 if (TYPE_PRECISION (TREE_TYPE (arg0)) != TYPE_PRECISION (TREE_TYPE (arg1)))
2728 /* In case both args are comparisons but with different comparison
2729 code, try to swap the comparison operands of one arg to produce
2730 a match and compare that variant. */
2731 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2732 && COMPARISON_CLASS_P (arg0)
2733 && COMPARISON_CLASS_P (arg1))
2735 enum tree_code swap_code = swap_tree_comparison (TREE_CODE (arg1));
2737 if (TREE_CODE (arg0) == swap_code)
2738 return operand_equal_p (TREE_OPERAND (arg0, 0),
2739 TREE_OPERAND (arg1, 1), flags)
2740 && operand_equal_p (TREE_OPERAND (arg0, 1),
2741 TREE_OPERAND (arg1, 0), flags);
2744 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2745 /* This is needed for conversions and for COMPONENT_REF.
2746 Might as well play it safe and always test this. */
2747 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
2748 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
2749 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
2752 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
2753 We don't care about side effects in that case because the SAVE_EXPR
2754 takes care of that for us. In all other cases, two expressions are
2755 equal if they have no side effects. If we have two identical
2756 expressions with side effects that should be treated the same due
2757 to the only side effects being identical SAVE_EXPR's, that will
2758 be detected in the recursive calls below. */
2759 if (arg0 == arg1 && ! (flags & OEP_ONLY_CONST)
2760 && (TREE_CODE (arg0) == SAVE_EXPR
2761 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
2764 /* Next handle constant cases, those for which we can return 1 even
2765 if ONLY_CONST is set. */
2766 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
2767 switch (TREE_CODE (arg0))
2770 return tree_int_cst_equal (arg0, arg1);
2773 if (REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
2774 TREE_REAL_CST (arg1)))
2778 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0))))
2780 /* If we do not distinguish between signed and unsigned zero,
2781 consider them equal. */
2782 if (real_zerop (arg0) && real_zerop (arg1))
2791 v1 = TREE_VECTOR_CST_ELTS (arg0);
2792 v2 = TREE_VECTOR_CST_ELTS (arg1);
2795 if (!operand_equal_p (TREE_VALUE (v1), TREE_VALUE (v2),
2798 v1 = TREE_CHAIN (v1);
2799 v2 = TREE_CHAIN (v2);
2806 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
2808 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
2812 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
2813 && ! memcmp (TREE_STRING_POINTER (arg0),
2814 TREE_STRING_POINTER (arg1),
2815 TREE_STRING_LENGTH (arg0)));
2818 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
2824 if (flags & OEP_ONLY_CONST)
2827 /* Define macros to test an operand from arg0 and arg1 for equality and a
2828 variant that allows null and views null as being different from any
2829 non-null value. In the latter case, if either is null, the both
2830 must be; otherwise, do the normal comparison. */
2831 #define OP_SAME(N) operand_equal_p (TREE_OPERAND (arg0, N), \
2832 TREE_OPERAND (arg1, N), flags)
2834 #define OP_SAME_WITH_NULL(N) \
2835 ((!TREE_OPERAND (arg0, N) || !TREE_OPERAND (arg1, N)) \
2836 ? TREE_OPERAND (arg0, N) == TREE_OPERAND (arg1, N) : OP_SAME (N))
2838 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
2841 /* Two conversions are equal only if signedness and modes match. */
2842 switch (TREE_CODE (arg0))
2846 case FIX_TRUNC_EXPR:
2847 if (TYPE_UNSIGNED (TREE_TYPE (arg0))
2848 != TYPE_UNSIGNED (TREE_TYPE (arg1)))
2858 case tcc_comparison:
2860 if (OP_SAME (0) && OP_SAME (1))
2863 /* For commutative ops, allow the other order. */
2864 return (commutative_tree_code (TREE_CODE (arg0))
2865 && operand_equal_p (TREE_OPERAND (arg0, 0),
2866 TREE_OPERAND (arg1, 1), flags)
2867 && operand_equal_p (TREE_OPERAND (arg0, 1),
2868 TREE_OPERAND (arg1, 0), flags));
2871 /* If either of the pointer (or reference) expressions we are
2872 dereferencing contain a side effect, these cannot be equal. */
2873 if (TREE_SIDE_EFFECTS (arg0)
2874 || TREE_SIDE_EFFECTS (arg1))
2877 switch (TREE_CODE (arg0))
2880 case ALIGN_INDIRECT_REF:
2881 case MISALIGNED_INDIRECT_REF:
2887 case ARRAY_RANGE_REF:
2888 /* Operands 2 and 3 may be null. */
2891 && OP_SAME_WITH_NULL (2)
2892 && OP_SAME_WITH_NULL (3));
2895 /* Handle operand 2 the same as for ARRAY_REF. Operand 0
2896 may be NULL when we're called to compare MEM_EXPRs. */
2897 return OP_SAME_WITH_NULL (0)
2899 && OP_SAME_WITH_NULL (2);
2902 return OP_SAME (0) && OP_SAME (1) && OP_SAME (2);
2908 case tcc_expression:
2909 switch (TREE_CODE (arg0))
2912 case TRUTH_NOT_EXPR:
2915 case TRUTH_ANDIF_EXPR:
2916 case TRUTH_ORIF_EXPR:
2917 return OP_SAME (0) && OP_SAME (1);
2919 case TRUTH_AND_EXPR:
2921 case TRUTH_XOR_EXPR:
2922 if (OP_SAME (0) && OP_SAME (1))
2925 /* Otherwise take into account this is a commutative operation. */
2926 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2927 TREE_OPERAND (arg1, 1), flags)
2928 && operand_equal_p (TREE_OPERAND (arg0, 1),
2929 TREE_OPERAND (arg1, 0), flags));
2936 switch (TREE_CODE (arg0))
2939 /* If the CALL_EXPRs call different functions, then they
2940 clearly can not be equal. */
2941 if (! operand_equal_p (CALL_EXPR_FN (arg0), CALL_EXPR_FN (arg1),
2946 unsigned int cef = call_expr_flags (arg0);
2947 if (flags & OEP_PURE_SAME)
2948 cef &= ECF_CONST | ECF_PURE;
2955 /* Now see if all the arguments are the same. */
2957 call_expr_arg_iterator iter0, iter1;
2959 for (a0 = first_call_expr_arg (arg0, &iter0),
2960 a1 = first_call_expr_arg (arg1, &iter1);
2962 a0 = next_call_expr_arg (&iter0),
2963 a1 = next_call_expr_arg (&iter1))
2964 if (! operand_equal_p (a0, a1, flags))
2967 /* If we get here and both argument lists are exhausted
2968 then the CALL_EXPRs are equal. */
2969 return ! (a0 || a1);
2975 case tcc_declaration:
2976 /* Consider __builtin_sqrt equal to sqrt. */
2977 return (TREE_CODE (arg0) == FUNCTION_DECL
2978 && DECL_BUILT_IN (arg0) && DECL_BUILT_IN (arg1)
2979 && DECL_BUILT_IN_CLASS (arg0) == DECL_BUILT_IN_CLASS (arg1)
2980 && DECL_FUNCTION_CODE (arg0) == DECL_FUNCTION_CODE (arg1));
2987 #undef OP_SAME_WITH_NULL
2990 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2991 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2993 When in doubt, return 0. */
2996 operand_equal_for_comparison_p (tree arg0, tree arg1, tree other)
2998 int unsignedp1, unsignedpo;
2999 tree primarg0, primarg1, primother;
3000 unsigned int correct_width;
3002 if (operand_equal_p (arg0, arg1, 0))
3005 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
3006 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
3009 /* Discard any conversions that don't change the modes of ARG0 and ARG1
3010 and see if the inner values are the same. This removes any
3011 signedness comparison, which doesn't matter here. */
3012 primarg0 = arg0, primarg1 = arg1;
3013 STRIP_NOPS (primarg0);
3014 STRIP_NOPS (primarg1);
3015 if (operand_equal_p (primarg0, primarg1, 0))
3018 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
3019 actual comparison operand, ARG0.
3021 First throw away any conversions to wider types
3022 already present in the operands. */
3024 primarg1 = get_narrower (arg1, &unsignedp1);
3025 primother = get_narrower (other, &unsignedpo);
3027 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
3028 if (unsignedp1 == unsignedpo
3029 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
3030 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
3032 tree type = TREE_TYPE (arg0);
3034 /* Make sure shorter operand is extended the right way
3035 to match the longer operand. */
3036 primarg1 = fold_convert (lang_hooks.types.signed_or_unsigned_type
3037 (unsignedp1, TREE_TYPE (primarg1)), primarg1);
3039 if (operand_equal_p (arg0, fold_convert (type, primarg1), 0))
3046 /* See if ARG is an expression that is either a comparison or is performing
3047 arithmetic on comparisons. The comparisons must only be comparing
3048 two different values, which will be stored in *CVAL1 and *CVAL2; if
3049 they are nonzero it means that some operands have already been found.
3050 No variables may be used anywhere else in the expression except in the
3051 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
3052 the expression and save_expr needs to be called with CVAL1 and CVAL2.
3054 If this is true, return 1. Otherwise, return zero. */
3057 twoval_comparison_p (tree arg, tree *cval1, tree *cval2, int *save_p)
3059 enum tree_code code = TREE_CODE (arg);
3060 enum tree_code_class class = TREE_CODE_CLASS (code);
3062 /* We can handle some of the tcc_expression cases here. */
3063 if (class == tcc_expression && code == TRUTH_NOT_EXPR)
3065 else if (class == tcc_expression
3066 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
3067 || code == COMPOUND_EXPR))
3070 else if (class == tcc_expression && code == SAVE_EXPR
3071 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
3073 /* If we've already found a CVAL1 or CVAL2, this expression is
3074 two complex to handle. */
3075 if (*cval1 || *cval2)
3085 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
3088 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
3089 && twoval_comparison_p (TREE_OPERAND (arg, 1),
3090 cval1, cval2, save_p));
3095 case tcc_expression:
3096 if (code == COND_EXPR)
3097 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
3098 cval1, cval2, save_p)
3099 && twoval_comparison_p (TREE_OPERAND (arg, 1),
3100 cval1, cval2, save_p)
3101 && twoval_comparison_p (TREE_OPERAND (arg, 2),
3102 cval1, cval2, save_p));
3105 case tcc_comparison:
3106 /* First see if we can handle the first operand, then the second. For
3107 the second operand, we know *CVAL1 can't be zero. It must be that
3108 one side of the comparison is each of the values; test for the
3109 case where this isn't true by failing if the two operands
3112 if (operand_equal_p (TREE_OPERAND (arg, 0),
3113 TREE_OPERAND (arg, 1), 0))
3117 *cval1 = TREE_OPERAND (arg, 0);
3118 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
3120 else if (*cval2 == 0)
3121 *cval2 = TREE_OPERAND (arg, 0);
3122 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
3127 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
3129 else if (*cval2 == 0)
3130 *cval2 = TREE_OPERAND (arg, 1);
3131 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
3143 /* ARG is a tree that is known to contain just arithmetic operations and
3144 comparisons. Evaluate the operations in the tree substituting NEW0 for
3145 any occurrence of OLD0 as an operand of a comparison and likewise for
3149 eval_subst (tree arg, tree old0, tree new0, tree old1, tree new1)
3151 tree type = TREE_TYPE (arg);
3152 enum tree_code code = TREE_CODE (arg);
3153 enum tree_code_class class = TREE_CODE_CLASS (code);
3155 /* We can handle some of the tcc_expression cases here. */
3156 if (class == tcc_expression && code == TRUTH_NOT_EXPR)
3158 else if (class == tcc_expression
3159 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
3165 return fold_build1 (code, type,
3166 eval_subst (TREE_OPERAND (arg, 0),
3167 old0, new0, old1, new1));
3170 return fold_build2 (code, type,
3171 eval_subst (TREE_OPERAND (arg, 0),
3172 old0, new0, old1, new1),
3173 eval_subst (TREE_OPERAND (arg, 1),
3174 old0, new0, old1, new1));
3176 case tcc_expression:
3180 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
3183 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
3186 return fold_build3 (code, type,
3187 eval_subst (TREE_OPERAND (arg, 0),
3188 old0, new0, old1, new1),
3189 eval_subst (TREE_OPERAND (arg, 1),
3190 old0, new0, old1, new1),
3191 eval_subst (TREE_OPERAND (arg, 2),
3192 old0, new0, old1, new1));
3196 /* Fall through - ??? */
3198 case tcc_comparison:
3200 tree arg0 = TREE_OPERAND (arg, 0);
3201 tree arg1 = TREE_OPERAND (arg, 1);
3203 /* We need to check both for exact equality and tree equality. The
3204 former will be true if the operand has a side-effect. In that
3205 case, we know the operand occurred exactly once. */
3207 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
3209 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
3212 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
3214 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
3217 return fold_build2 (code, type, arg0, arg1);
3225 /* Return a tree for the case when the result of an expression is RESULT
3226 converted to TYPE and OMITTED was previously an operand of the expression
3227 but is now not needed (e.g., we folded OMITTED * 0).
3229 If OMITTED has side effects, we must evaluate it. Otherwise, just do
3230 the conversion of RESULT to TYPE. */
3233 omit_one_operand (tree type, tree result, tree omitted)
3235 tree t = fold_convert (type, result);
3237 if (TREE_SIDE_EFFECTS (omitted))
3238 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
3240 return non_lvalue (t);
3243 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
3246 pedantic_omit_one_operand (tree type, tree result, tree omitted)
3248 tree t = fold_convert (type, result);
3250 if (TREE_SIDE_EFFECTS (omitted))
3251 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
3253 return pedantic_non_lvalue (t);
3256 /* Return a tree for the case when the result of an expression is RESULT
3257 converted to TYPE and OMITTED1 and OMITTED2 were previously operands
3258 of the expression but are now not needed.
3260 If OMITTED1 or OMITTED2 has side effects, they must be evaluated.
3261 If both OMITTED1 and OMITTED2 have side effects, OMITTED1 is
3262 evaluated before OMITTED2. Otherwise, if neither has side effects,
3263 just do the conversion of RESULT to TYPE. */
3266 omit_two_operands (tree type, tree result, tree omitted1, tree omitted2)
3268 tree t = fold_convert (type, result);
3270 if (TREE_SIDE_EFFECTS (omitted2))
3271 t = build2 (COMPOUND_EXPR, type, omitted2, t);
3272 if (TREE_SIDE_EFFECTS (omitted1))
3273 t = build2 (COMPOUND_EXPR, type, omitted1, t);
3275 return TREE_CODE (t) != COMPOUND_EXPR ? non_lvalue (t) : t;
3279 /* Return a simplified tree node for the truth-negation of ARG. This
3280 never alters ARG itself. We assume that ARG is an operation that
3281 returns a truth value (0 or 1).
3283 FIXME: one would think we would fold the result, but it causes
3284 problems with the dominator optimizer. */
3287 fold_truth_not_expr (tree arg)
3289 tree type = TREE_TYPE (arg);
3290 enum tree_code code = TREE_CODE (arg);
3292 /* If this is a comparison, we can simply invert it, except for
3293 floating-point non-equality comparisons, in which case we just
3294 enclose a TRUTH_NOT_EXPR around what we have. */
3296 if (TREE_CODE_CLASS (code) == tcc_comparison)
3298 tree op_type = TREE_TYPE (TREE_OPERAND (arg, 0));
3299 if (FLOAT_TYPE_P (op_type)
3300 && flag_trapping_math
3301 && code != ORDERED_EXPR && code != UNORDERED_EXPR
3302 && code != NE_EXPR && code != EQ_EXPR)
3306 code = invert_tree_comparison (code,
3307 HONOR_NANS (TYPE_MODE (op_type)));
3308 if (code == ERROR_MARK)
3311 return build2 (code, type,
3312 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
3319 return constant_boolean_node (integer_zerop (arg), type);
3321 case TRUTH_AND_EXPR:
3322 return build2 (TRUTH_OR_EXPR, type,
3323 invert_truthvalue (TREE_OPERAND (arg, 0)),
3324 invert_truthvalue (TREE_OPERAND (arg, 1)));
3327 return build2 (TRUTH_AND_EXPR, type,
3328 invert_truthvalue (TREE_OPERAND (arg, 0)),
3329 invert_truthvalue (TREE_OPERAND (arg, 1)));
3331 case TRUTH_XOR_EXPR:
3332 /* Here we can invert either operand. We invert the first operand
3333 unless the second operand is a TRUTH_NOT_EXPR in which case our
3334 result is the XOR of the first operand with the inside of the
3335 negation of the second operand. */
3337 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
3338 return build2 (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
3339 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
3341 return build2 (TRUTH_XOR_EXPR, type,
3342 invert_truthvalue (TREE_OPERAND (arg, 0)),
3343 TREE_OPERAND (arg, 1));
3345 case TRUTH_ANDIF_EXPR:
3346 return build2 (TRUTH_ORIF_EXPR, type,
3347 invert_truthvalue (TREE_OPERAND (arg, 0)),
3348 invert_truthvalue (TREE_OPERAND (arg, 1)));
3350 case TRUTH_ORIF_EXPR:
3351 return build2 (TRUTH_ANDIF_EXPR, type,
3352 invert_truthvalue (TREE_OPERAND (arg, 0)),
3353 invert_truthvalue (TREE_OPERAND (arg, 1)));
3355 case TRUTH_NOT_EXPR:
3356 return TREE_OPERAND (arg, 0);
3360 tree arg1 = TREE_OPERAND (arg, 1);
3361 tree arg2 = TREE_OPERAND (arg, 2);
3362 /* A COND_EXPR may have a throw as one operand, which
3363 then has void type. Just leave void operands
3365 return build3 (COND_EXPR, type, TREE_OPERAND (arg, 0),
3366 VOID_TYPE_P (TREE_TYPE (arg1))
3367 ? arg1 : invert_truthvalue (arg1),
3368 VOID_TYPE_P (TREE_TYPE (arg2))
3369 ? arg2 : invert_truthvalue (arg2));
3373 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
3374 invert_truthvalue (TREE_OPERAND (arg, 1)));
3376 case NON_LVALUE_EXPR:
3377 return invert_truthvalue (TREE_OPERAND (arg, 0));
3380 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE)
3381 return build1 (TRUTH_NOT_EXPR, type, arg);
3385 return build1 (TREE_CODE (arg), type,
3386 invert_truthvalue (TREE_OPERAND (arg, 0)));
3389 if (!integer_onep (TREE_OPERAND (arg, 1)))
3391 return build2 (EQ_EXPR, type, arg,
3392 build_int_cst (type, 0));
3395 return build1 (TRUTH_NOT_EXPR, type, arg);
3397 case CLEANUP_POINT_EXPR:
3398 return build1 (CLEANUP_POINT_EXPR, type,
3399 invert_truthvalue (TREE_OPERAND (arg, 0)));
3408 /* Return a simplified tree node for the truth-negation of ARG. This
3409 never alters ARG itself. We assume that ARG is an operation that
3410 returns a truth value (0 or 1).
3412 FIXME: one would think we would fold the result, but it causes
3413 problems with the dominator optimizer. */
3416 invert_truthvalue (tree arg)
3420 if (TREE_CODE (arg) == ERROR_MARK)
3423 tem = fold_truth_not_expr (arg);
3425 tem = build1 (TRUTH_NOT_EXPR, TREE_TYPE (arg), arg);
3430 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
3431 operands are another bit-wise operation with a common input. If so,
3432 distribute the bit operations to save an operation and possibly two if
3433 constants are involved. For example, convert
3434 (A | B) & (A | C) into A | (B & C)
3435 Further simplification will occur if B and C are constants.
3437 If this optimization cannot be done, 0 will be returned. */
3440 distribute_bit_expr (enum tree_code code, tree type, tree arg0, tree arg1)
3445 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3446 || TREE_CODE (arg0) == code
3447 || (TREE_CODE (arg0) != BIT_AND_EXPR
3448 && TREE_CODE (arg0) != BIT_IOR_EXPR))
3451 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
3453 common = TREE_OPERAND (arg0, 0);
3454 left = TREE_OPERAND (arg0, 1);
3455 right = TREE_OPERAND (arg1, 1);
3457 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
3459 common = TREE_OPERAND (arg0, 0);
3460 left = TREE_OPERAND (arg0, 1);
3461 right = TREE_OPERAND (arg1, 0);
3463 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
3465 common = TREE_OPERAND (arg0, 1);
3466 left = TREE_OPERAND (arg0, 0);
3467 right = TREE_OPERAND (arg1, 1);
3469 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
3471 common = TREE_OPERAND (arg0, 1);
3472 left = TREE_OPERAND (arg0, 0);
3473 right = TREE_OPERAND (arg1, 0);
3478 return fold_build2 (TREE_CODE (arg0), type, common,
3479 fold_build2 (code, type, left, right));
3482 /* Knowing that ARG0 and ARG1 are both RDIV_EXPRs, simplify a binary operation
3483 with code CODE. This optimization is unsafe. */
3485 distribute_real_division (enum tree_code code, tree type, tree arg0, tree arg1)
3487 bool mul0 = TREE_CODE (arg0) == MULT_EXPR;
3488 bool mul1 = TREE_CODE (arg1) == MULT_EXPR;
3490 /* (A / C) +- (B / C) -> (A +- B) / C. */
3492 && operand_equal_p (TREE_OPERAND (arg0, 1),
3493 TREE_OPERAND (arg1, 1), 0))
3494 return fold_build2 (mul0 ? MULT_EXPR : RDIV_EXPR, type,
3495 fold_build2 (code, type,
3496 TREE_OPERAND (arg0, 0),
3497 TREE_OPERAND (arg1, 0)),
3498 TREE_OPERAND (arg0, 1));
3500 /* (A / C1) +- (A / C2) -> A * (1 / C1 +- 1 / C2). */
3501 if (operand_equal_p (TREE_OPERAND (arg0, 0),
3502 TREE_OPERAND (arg1, 0), 0)
3503 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
3504 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
3506 REAL_VALUE_TYPE r0, r1;
3507 r0 = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
3508 r1 = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
3510 real_arithmetic (&r0, RDIV_EXPR, &dconst1, &r0);
3512 real_arithmetic (&r1, RDIV_EXPR, &dconst1, &r1);
3513 real_arithmetic (&r0, code, &r0, &r1);
3514 return fold_build2 (MULT_EXPR, type,
3515 TREE_OPERAND (arg0, 0),
3516 build_real (type, r0));
3522 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
3523 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
3526 make_bit_field_ref (tree inner, tree type, int bitsize, int bitpos,
3533 tree size = TYPE_SIZE (TREE_TYPE (inner));
3534 if ((INTEGRAL_TYPE_P (TREE_TYPE (inner))
3535 || POINTER_TYPE_P (TREE_TYPE (inner)))
3536 && host_integerp (size, 0)
3537 && tree_low_cst (size, 0) == bitsize)
3538 return fold_convert (type, inner);
3541 result = build3 (BIT_FIELD_REF, type, inner,
3542 size_int (bitsize), bitsize_int (bitpos));
3544 BIT_FIELD_REF_UNSIGNED (result) = unsignedp;
3549 /* Optimize a bit-field compare.
3551 There are two cases: First is a compare against a constant and the
3552 second is a comparison of two items where the fields are at the same
3553 bit position relative to the start of a chunk (byte, halfword, word)
3554 large enough to contain it. In these cases we can avoid the shift
3555 implicit in bitfield extractions.
3557 For constants, we emit a compare of the shifted constant with the
3558 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
3559 compared. For two fields at the same position, we do the ANDs with the
3560 similar mask and compare the result of the ANDs.
3562 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
3563 COMPARE_TYPE is the type of the comparison, and LHS and RHS
3564 are the left and right operands of the comparison, respectively.
3566 If the optimization described above can be done, we return the resulting
3567 tree. Otherwise we return zero. */
3570 optimize_bit_field_compare (enum tree_code code, tree compare_type,
3573 HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
3574 tree type = TREE_TYPE (lhs);
3575 tree signed_type, unsigned_type;
3576 int const_p = TREE_CODE (rhs) == INTEGER_CST;
3577 enum machine_mode lmode, rmode, nmode;
3578 int lunsignedp, runsignedp;
3579 int lvolatilep = 0, rvolatilep = 0;
3580 tree linner, rinner = NULL_TREE;
3584 /* Get all the information about the extractions being done. If the bit size
3585 if the same as the size of the underlying object, we aren't doing an
3586 extraction at all and so can do nothing. We also don't want to
3587 do anything if the inner expression is a PLACEHOLDER_EXPR since we
3588 then will no longer be able to replace it. */
3589 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
3590 &lunsignedp, &lvolatilep, false);
3591 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
3592 || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
3597 /* If this is not a constant, we can only do something if bit positions,
3598 sizes, and signedness are the same. */
3599 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
3600 &runsignedp, &rvolatilep, false);
3602 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
3603 || lunsignedp != runsignedp || offset != 0
3604 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
3608 /* See if we can find a mode to refer to this field. We should be able to,
3609 but fail if we can't. */
3610 nmode = get_best_mode (lbitsize, lbitpos,
3611 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
3612 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
3613 TYPE_ALIGN (TREE_TYPE (rinner))),
3614 word_mode, lvolatilep || rvolatilep);
3615 if (nmode == VOIDmode)
3618 /* Set signed and unsigned types of the precision of this mode for the
3620 signed_type = lang_hooks.types.type_for_mode (nmode, 0);
3621 unsigned_type = lang_hooks.types.type_for_mode (nmode, 1);
3623 /* Compute the bit position and size for the new reference and our offset
3624 within it. If the new reference is the same size as the original, we
3625 won't optimize anything, so return zero. */
3626 nbitsize = GET_MODE_BITSIZE (nmode);
3627 nbitpos = lbitpos & ~ (nbitsize - 1);
3629 if (nbitsize == lbitsize)
3632 if (BYTES_BIG_ENDIAN)
3633 lbitpos = nbitsize - lbitsize - lbitpos;
3635 /* Make the mask to be used against the extracted field. */
3636 mask = build_int_cst_type (unsigned_type, -1);
3637 mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
3638 mask = const_binop (RSHIFT_EXPR, mask,
3639 size_int (nbitsize - lbitsize - lbitpos), 0);
3642 /* If not comparing with constant, just rework the comparison
3644 return fold_build2 (code, compare_type,
3645 fold_build2 (BIT_AND_EXPR, unsigned_type,
3646 make_bit_field_ref (linner,
3651 fold_build2 (BIT_AND_EXPR, unsigned_type,
3652 make_bit_field_ref (rinner,
3658 /* Otherwise, we are handling the constant case. See if the constant is too
3659 big for the field. Warn and return a tree of for 0 (false) if so. We do
3660 this not only for its own sake, but to avoid having to test for this
3661 error case below. If we didn't, we might generate wrong code.
3663 For unsigned fields, the constant shifted right by the field length should
3664 be all zero. For signed fields, the high-order bits should agree with
3669 if (! integer_zerop (const_binop (RSHIFT_EXPR,
3670 fold_convert (unsigned_type, rhs),
3671 size_int (lbitsize), 0)))
3673 warning (0, "comparison is always %d due to width of bit-field",
3675 return constant_boolean_node (code == NE_EXPR, compare_type);
3680 tree tem = const_binop (RSHIFT_EXPR, fold_convert (signed_type, rhs),
3681 size_int (lbitsize - 1), 0);
3682 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
3684 warning (0, "comparison is always %d due to width of bit-field",
3686 return constant_boolean_node (code == NE_EXPR, compare_type);
3690 /* Single-bit compares should always be against zero. */
3691 if (lbitsize == 1 && ! integer_zerop (rhs))
3693 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
3694 rhs = build_int_cst (type, 0);
3697 /* Make a new bitfield reference, shift the constant over the
3698 appropriate number of bits and mask it with the computed mask
3699 (in case this was a signed field). If we changed it, make a new one. */
3700 lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1);
3703 TREE_SIDE_EFFECTS (lhs) = 1;
3704 TREE_THIS_VOLATILE (lhs) = 1;
3707 rhs = const_binop (BIT_AND_EXPR,
3708 const_binop (LSHIFT_EXPR,
3709 fold_convert (unsigned_type, rhs),
3710 size_int (lbitpos), 0),
3713 return build2 (code, compare_type,
3714 build2 (BIT_AND_EXPR, unsigned_type, lhs, mask),
3718 /* Subroutine for fold_truthop: decode a field reference.
3720 If EXP is a comparison reference, we return the innermost reference.
3722 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
3723 set to the starting bit number.
3725 If the innermost field can be completely contained in a mode-sized
3726 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
3728 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
3729 otherwise it is not changed.
3731 *PUNSIGNEDP is set to the signedness of the field.
3733 *PMASK is set to the mask used. This is either contained in a
3734 BIT_AND_EXPR or derived from the width of the field.
3736 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
3738 Return 0 if this is not a component reference or is one that we can't
3739 do anything with. */
3742 decode_field_reference (tree exp, HOST_WIDE_INT *pbitsize,
3743 HOST_WIDE_INT *pbitpos, enum machine_mode *pmode,
3744 int *punsignedp, int *pvolatilep,
3745 tree *pmask, tree *pand_mask)
3747 tree outer_type = 0;
3749 tree mask, inner, offset;
3751 unsigned int precision;
3753 /* All the optimizations using this function assume integer fields.
3754 There are problems with FP fields since the type_for_size call
3755 below can fail for, e.g., XFmode. */
3756 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
3759 /* We are interested in the bare arrangement of bits, so strip everything
3760 that doesn't affect the machine mode. However, record the type of the
3761 outermost expression if it may matter below. */
3762 if (TREE_CODE (exp) == NOP_EXPR
3763 || TREE_CODE (exp) == CONVERT_EXPR
3764 || TREE_CODE (exp) == NON_LVALUE_EXPR)
3765 outer_type = TREE_TYPE (exp);
3768 if (TREE_CODE (exp) == BIT_AND_EXPR)
3770 and_mask = TREE_OPERAND (exp, 1);
3771 exp = TREE_OPERAND (exp, 0);
3772 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
3773 if (TREE_CODE (and_mask) != INTEGER_CST)
3777 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
3778 punsignedp, pvolatilep, false);
3779 if ((inner == exp && and_mask == 0)
3780 || *pbitsize < 0 || offset != 0
3781 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
3784 /* If the number of bits in the reference is the same as the bitsize of
3785 the outer type, then the outer type gives the signedness. Otherwise
3786 (in case of a small bitfield) the signedness is unchanged. */
3787 if (outer_type && *pbitsize == TYPE_PRECISION (outer_type))
3788 *punsignedp = TYPE_UNSIGNED (outer_type);
3790 /* Compute the mask to access the bitfield. */
3791 unsigned_type = lang_hooks.types.type_for_size (*pbitsize, 1);
3792 precision = TYPE_PRECISION (unsigned_type);
3794 mask = build_int_cst_type (unsigned_type, -1);
3796 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3797 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3799 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
3801 mask = fold_build2 (BIT_AND_EXPR, unsigned_type,
3802 fold_convert (unsigned_type, and_mask), mask);
3805 *pand_mask = and_mask;
3809 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
3813 all_ones_mask_p (tree mask, int size)
3815 tree type = TREE_TYPE (mask);
3816 unsigned int precision = TYPE_PRECISION (type);
3819 tmask = build_int_cst_type (lang_hooks.types.signed_type (type), -1);
3822 tree_int_cst_equal (mask,
3823 const_binop (RSHIFT_EXPR,
3824 const_binop (LSHIFT_EXPR, tmask,
3825 size_int (precision - size),
3827 size_int (precision - size), 0));
3830 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
3831 represents the sign bit of EXP's type. If EXP represents a sign
3832 or zero extension, also test VAL against the unextended type.
3833 The return value is the (sub)expression whose sign bit is VAL,
3834 or NULL_TREE otherwise. */
3837 sign_bit_p (tree exp, tree val)
3839 unsigned HOST_WIDE_INT mask_lo, lo;
3840 HOST_WIDE_INT mask_hi, hi;
3844 /* Tree EXP must have an integral type. */
3845 t = TREE_TYPE (exp);
3846 if (! INTEGRAL_TYPE_P (t))
3849 /* Tree VAL must be an integer constant. */
3850 if (TREE_CODE (val) != INTEGER_CST
3851 || TREE_OVERFLOW (val))
3854 width = TYPE_PRECISION (t);
3855 if (width > HOST_BITS_PER_WIDE_INT)
3857 hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1);
3860 mask_hi = ((unsigned HOST_WIDE_INT) -1
3861 >> (2 * HOST_BITS_PER_WIDE_INT - width));
3867 lo = (unsigned HOST_WIDE_INT) 1 << (width - 1);
3870 mask_lo = ((unsigned HOST_WIDE_INT) -1
3871 >> (HOST_BITS_PER_WIDE_INT - width));
3874 /* We mask off those bits beyond TREE_TYPE (exp) so that we can
3875 treat VAL as if it were unsigned. */
3876 if ((TREE_INT_CST_HIGH (val) & mask_hi) == hi
3877 && (TREE_INT_CST_LOW (val) & mask_lo) == lo)
3880 /* Handle extension from a narrower type. */
3881 if (TREE_CODE (exp) == NOP_EXPR
3882 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width)
3883 return sign_bit_p (TREE_OPERAND (exp, 0), val);
3888 /* Subroutine for fold_truthop: determine if an operand is simple enough
3889 to be evaluated unconditionally. */
3892 simple_operand_p (tree exp)
3894 /* Strip any conversions that don't change the machine mode. */
3897 return (CONSTANT_CLASS_P (exp)
3898 || TREE_CODE (exp) == SSA_NAME
3900 && ! TREE_ADDRESSABLE (exp)
3901 && ! TREE_THIS_VOLATILE (exp)
3902 && ! DECL_NONLOCAL (exp)
3903 /* Don't regard global variables as simple. They may be
3904 allocated in ways unknown to the compiler (shared memory,
3905 #pragma weak, etc). */
3906 && ! TREE_PUBLIC (exp)
3907 && ! DECL_EXTERNAL (exp)
3908 /* Loading a static variable is unduly expensive, but global
3909 registers aren't expensive. */
3910 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
3913 /* The following functions are subroutines to fold_range_test and allow it to
3914 try to change a logical combination of comparisons into a range test.
3917 X == 2 || X == 3 || X == 4 || X == 5
3921 (unsigned) (X - 2) <= 3
3923 We describe each set of comparisons as being either inside or outside
3924 a range, using a variable named like IN_P, and then describe the
3925 range with a lower and upper bound. If one of the bounds is omitted,
3926 it represents either the highest or lowest value of the type.
3928 In the comments below, we represent a range by two numbers in brackets
3929 preceded by a "+" to designate being inside that range, or a "-" to
3930 designate being outside that range, so the condition can be inverted by
3931 flipping the prefix. An omitted bound is represented by a "-". For
3932 example, "- [-, 10]" means being outside the range starting at the lowest
3933 possible value and ending at 10, in other words, being greater than 10.
3934 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
3937 We set up things so that the missing bounds are handled in a consistent
3938 manner so neither a missing bound nor "true" and "false" need to be
3939 handled using a special case. */
3941 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
3942 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
3943 and UPPER1_P are nonzero if the respective argument is an upper bound
3944 and zero for a lower. TYPE, if nonzero, is the type of the result; it
3945 must be specified for a comparison. ARG1 will be converted to ARG0's
3946 type if both are specified. */
3949 range_binop (enum tree_code code, tree type, tree arg0, int upper0_p,
3950 tree arg1, int upper1_p)
3956 /* If neither arg represents infinity, do the normal operation.
3957 Else, if not a comparison, return infinity. Else handle the special
3958 comparison rules. Note that most of the cases below won't occur, but
3959 are handled for consistency. */
3961 if (arg0 != 0 && arg1 != 0)
3963 tem = fold_build2 (code, type != 0 ? type : TREE_TYPE (arg0),
3964 arg0, fold_convert (TREE_TYPE (arg0), arg1));
3966 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
3969 if (TREE_CODE_CLASS (code) != tcc_comparison)
3972 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
3973 for neither. In real maths, we cannot assume open ended ranges are
3974 the same. But, this is computer arithmetic, where numbers are finite.
3975 We can therefore make the transformation of any unbounded range with
3976 the value Z, Z being greater than any representable number. This permits
3977 us to treat unbounded ranges as equal. */
3978 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
3979 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
3983 result = sgn0 == sgn1;
3986 result = sgn0 != sgn1;
3989 result = sgn0 < sgn1;
3992 result = sgn0 <= sgn1;
3995 result = sgn0 > sgn1;
3998 result = sgn0 >= sgn1;
4004 return constant_boolean_node (result, type);
4007 /* Given EXP, a logical expression, set the range it is testing into
4008 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
4009 actually being tested. *PLOW and *PHIGH will be made of the same
4010 type as the returned expression. If EXP is not a comparison, we
4011 will most likely not be returning a useful value and range. Set
4012 *STRICT_OVERFLOW_P to true if the return value is only valid
4013 because signed overflow is undefined; otherwise, do not change
4014 *STRICT_OVERFLOW_P. */
4017 make_range (tree exp, int *pin_p, tree *plow, tree *phigh,
4018 bool *strict_overflow_p)
4020 enum tree_code code;
4021 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
4022 tree exp_type = NULL_TREE, arg0_type = NULL_TREE;
4024 tree low, high, n_low, n_high;
4026 /* Start with simply saying "EXP != 0" and then look at the code of EXP
4027 and see if we can refine the range. Some of the cases below may not
4028 happen, but it doesn't seem worth worrying about this. We "continue"
4029 the outer loop when we've changed something; otherwise we "break"
4030 the switch, which will "break" the while. */
4033 low = high = build_int_cst (TREE_TYPE (exp), 0);
4037 code = TREE_CODE (exp);
4038 exp_type = TREE_TYPE (exp);
4040 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
4042 if (TREE_OPERAND_LENGTH (exp) > 0)
4043 arg0 = TREE_OPERAND (exp, 0);
4044 if (TREE_CODE_CLASS (code) == tcc_comparison
4045 || TREE_CODE_CLASS (code) == tcc_unary
4046 || TREE_CODE_CLASS (code) == tcc_binary)
4047 arg0_type = TREE_TYPE (arg0);
4048 if (TREE_CODE_CLASS (code) == tcc_binary
4049 || TREE_CODE_CLASS (code) == tcc_comparison
4050 || (TREE_CODE_CLASS (code) == tcc_expression
4051 && TREE_OPERAND_LENGTH (exp) > 1))
4052 arg1 = TREE_OPERAND (exp, 1);
4057 case TRUTH_NOT_EXPR:
4058 in_p = ! in_p, exp = arg0;
4061 case EQ_EXPR: case NE_EXPR:
4062 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
4063 /* We can only do something if the range is testing for zero
4064 and if the second operand is an integer constant. Note that
4065 saying something is "in" the range we make is done by
4066 complementing IN_P since it will set in the initial case of
4067 being not equal to zero; "out" is leaving it alone. */
4068 if (low == 0 || high == 0
4069 || ! integer_zerop (low) || ! integer_zerop (high)
4070 || TREE_CODE (arg1) != INTEGER_CST)
4075 case NE_EXPR: /* - [c, c] */
4078 case EQ_EXPR: /* + [c, c] */
4079 in_p = ! in_p, low = high = arg1;
4081 case GT_EXPR: /* - [-, c] */
4082 low = 0, high = arg1;
4084 case GE_EXPR: /* + [c, -] */
4085 in_p = ! in_p, low = arg1, high = 0;
4087 case LT_EXPR: /* - [c, -] */
4088 low = arg1, high = 0;
4090 case LE_EXPR: /* + [-, c] */
4091 in_p = ! in_p, low = 0, high = arg1;
4097 /* If this is an unsigned comparison, we also know that EXP is
4098 greater than or equal to zero. We base the range tests we make
4099 on that fact, so we record it here so we can parse existing
4100 range tests. We test arg0_type since often the return type
4101 of, e.g. EQ_EXPR, is boolean. */
4102 if (TYPE_UNSIGNED (arg0_type) && (low == 0 || high == 0))
4104 if (! merge_ranges (&n_in_p, &n_low, &n_high,
4106 build_int_cst (arg0_type, 0),
4110 in_p = n_in_p, low = n_low, high = n_high;
4112 /* If the high bound is missing, but we have a nonzero low
4113 bound, reverse the range so it goes from zero to the low bound
4115 if (high == 0 && low && ! integer_zerop (low))
4118 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
4119 integer_one_node, 0);
4120 low = build_int_cst (arg0_type, 0);
4128 /* (-x) IN [a,b] -> x in [-b, -a] */
4129 n_low = range_binop (MINUS_EXPR, exp_type,
4130 build_int_cst (exp_type, 0),
4132 n_high = range_binop (MINUS_EXPR, exp_type,
4133 build_int_cst (exp_type, 0),
4135 low = n_low, high = n_high;
4141 exp = build2 (MINUS_EXPR, exp_type, negate_expr (arg0),
4142 build_int_cst (exp_type, 1));
4145 case PLUS_EXPR: case MINUS_EXPR:
4146 if (TREE_CODE (arg1) != INTEGER_CST)
4149 /* If flag_wrapv and ARG0_TYPE is signed, then we cannot
4150 move a constant to the other side. */
4151 if (!TYPE_UNSIGNED (arg0_type)
4152 && !TYPE_OVERFLOW_UNDEFINED (arg0_type))
4155 /* If EXP is signed, any overflow in the computation is undefined,
4156 so we don't worry about it so long as our computations on
4157 the bounds don't overflow. For unsigned, overflow is defined
4158 and this is exactly the right thing. */
4159 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
4160 arg0_type, low, 0, arg1, 0);
4161 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
4162 arg0_type, high, 1, arg1, 0);
4163 if ((n_low != 0 && TREE_OVERFLOW (n_low))
4164 || (n_high != 0 && TREE_OVERFLOW (n_high)))
4167 if (TYPE_OVERFLOW_UNDEFINED (arg0_type))
4168 *strict_overflow_p = true;
4170 /* Check for an unsigned range which has wrapped around the maximum
4171 value thus making n_high < n_low, and normalize it. */
4172 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
4174 low = range_binop (PLUS_EXPR, arg0_type, n_high, 0,
4175 integer_one_node, 0);
4176 high = range_binop (MINUS_EXPR, arg0_type, n_low, 0,
4177 integer_one_node, 0);
4179 /* If the range is of the form +/- [ x+1, x ], we won't
4180 be able to normalize it. But then, it represents the
4181 whole range or the empty set, so make it
4183 if (tree_int_cst_equal (n_low, low)
4184 && tree_int_cst_equal (n_high, high))
4190 low = n_low, high = n_high;
4195 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
4196 if (TYPE_PRECISION (arg0_type) > TYPE_PRECISION (exp_type))
4199 if (! INTEGRAL_TYPE_P (arg0_type)
4200 || (low != 0 && ! int_fits_type_p (low, arg0_type))
4201 || (high != 0 && ! int_fits_type_p (high, arg0_type)))
4204 n_low = low, n_high = high;
4207 n_low = fold_convert (arg0_type, n_low);
4210 n_high = fold_convert (arg0_type, n_high);
4213 /* If we're converting arg0 from an unsigned type, to exp,
4214 a signed type, we will be doing the comparison as unsigned.
4215 The tests above have already verified that LOW and HIGH
4218 So we have to ensure that we will handle large unsigned
4219 values the same way that the current signed bounds treat
4222 if (!TYPE_UNSIGNED (exp_type) && TYPE_UNSIGNED (arg0_type))
4225 tree equiv_type = lang_hooks.types.type_for_mode
4226 (TYPE_MODE (arg0_type), 1);
4228 /* A range without an upper bound is, naturally, unbounded.
4229 Since convert would have cropped a very large value, use
4230 the max value for the destination type. */
4232 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
4233 : TYPE_MAX_VALUE (arg0_type);
4235 if (TYPE_PRECISION (exp_type) == TYPE_PRECISION (arg0_type))
4236 high_positive = fold_build2 (RSHIFT_EXPR, arg0_type,
4237 fold_convert (arg0_type,
4239 build_int_cst (arg0_type, 1));
4241 /* If the low bound is specified, "and" the range with the
4242 range for which the original unsigned value will be
4246 if (! merge_ranges (&n_in_p, &n_low, &n_high,
4247 1, n_low, n_high, 1,
4248 fold_convert (arg0_type,
4253 in_p = (n_in_p == in_p);
4257 /* Otherwise, "or" the range with the range of the input
4258 that will be interpreted as negative. */
4259 if (! merge_ranges (&n_in_p, &n_low, &n_high,
4260 0, n_low, n_high, 1,
4261 fold_convert (arg0_type,
4266 in_p = (in_p != n_in_p);
4271 low = n_low, high = n_high;
4281 /* If EXP is a constant, we can evaluate whether this is true or false. */
4282 if (TREE_CODE (exp) == INTEGER_CST)
4284 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
4286 && integer_onep (range_binop (LE_EXPR, integer_type_node,
4292 *pin_p = in_p, *plow = low, *phigh = high;
4296 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
4297 type, TYPE, return an expression to test if EXP is in (or out of, depending
4298 on IN_P) the range. Return 0 if the test couldn't be created. */
4301 build_range_check (tree type, tree exp, int in_p, tree low, tree high)
4303 tree etype = TREE_TYPE (exp);
4306 #ifdef HAVE_canonicalize_funcptr_for_compare
4307 /* Disable this optimization for function pointer expressions
4308 on targets that require function pointer canonicalization. */
4309 if (HAVE_canonicalize_funcptr_for_compare
4310 && TREE_CODE (etype) == POINTER_TYPE
4311 && TREE_CODE (TREE_TYPE (etype)) == FUNCTION_TYPE)
4317 value = build_range_check (type, exp, 1, low, high);
4319 return invert_truthvalue (value);
4324 if (low == 0 && high == 0)
4325 return build_int_cst (type, 1);
4328 return fold_build2 (LE_EXPR, type, exp,
4329 fold_convert (etype, high));
4332 return fold_build2 (GE_EXPR, type, exp,
4333 fold_convert (etype, low));
4335 if (operand_equal_p (low, high, 0))
4336 return fold_build2 (EQ_EXPR, type, exp,
4337 fold_convert (etype, low));
4339 if (integer_zerop (low))
4341 if (! TYPE_UNSIGNED (etype))
4343 etype = lang_hooks.types.unsigned_type (etype);
4344 high = fold_convert (etype, high);
4345 exp = fold_convert (etype, exp);
4347 return build_range_check (type, exp, 1, 0, high);
4350 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
4351 if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST)
4353 unsigned HOST_WIDE_INT lo;
4357 prec = TYPE_PRECISION (etype);
4358 if (prec <= HOST_BITS_PER_WIDE_INT)
4361 lo = ((unsigned HOST_WIDE_INT) 1 << (prec - 1)) - 1;
4365 hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1;
4366 lo = (unsigned HOST_WIDE_INT) -1;
4369 if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo)
4371 if (TYPE_UNSIGNED (etype))
4373 etype = lang_hooks.types.signed_type (etype);
4374 exp = fold_convert (etype, exp);
4376 return fold_build2 (GT_EXPR, type, exp,
4377 build_int_cst (etype, 0));
4381 /* Optimize (c>=low) && (c<=high) into (c-low>=0) && (c-low<=high-low).
4382 This requires wrap-around arithmetics for the type of the expression. */
4383 switch (TREE_CODE (etype))
4386 /* There is no requirement that LOW be within the range of ETYPE
4387 if the latter is a subtype. It must, however, be within the base
4388 type of ETYPE. So be sure we do the subtraction in that type. */
4389 if (TREE_TYPE (etype))
4390 etype = TREE_TYPE (etype);
4395 etype = lang_hooks.types.type_for_size (TYPE_PRECISION (etype),
4396 TYPE_UNSIGNED (etype));
4403 /* If we don't have wrap-around arithmetics upfront, try to force it. */
4404 if (TREE_CODE (etype) == INTEGER_TYPE
4405 && !TYPE_OVERFLOW_WRAPS (etype))
4407 tree utype, minv, maxv;
4409 /* Check if (unsigned) INT_MAX + 1 == (unsigned) INT_MIN
4410 for the type in question, as we rely on this here. */
4411 utype = lang_hooks.types.unsigned_type (etype);
4412 maxv = fold_convert (utype, TYPE_MAX_VALUE (etype));
4413 maxv = range_binop (PLUS_EXPR, NULL_TREE, maxv, 1,
4414 integer_one_node, 1);
4415 minv = fold_convert (utype, TYPE_MIN_VALUE (etype));
4417 if (integer_zerop (range_binop (NE_EXPR, integer_type_node,
4424 high = fold_convert (etype, high);
4425 low = fold_convert (etype, low);
4426 exp = fold_convert (etype, exp);
4428 value = const_binop (MINUS_EXPR, high, low, 0);
4430 if (value != 0 && !TREE_OVERFLOW (value))
4431 return build_range_check (type,
4432 fold_build2 (MINUS_EXPR, etype, exp, low),
4433 1, build_int_cst (etype, 0), value);
4438 /* Return the predecessor of VAL in its type, handling the infinite case. */
4441 range_predecessor (tree val)
4443 tree type = TREE_TYPE (val);
4445 if (INTEGRAL_TYPE_P (type)
4446 && operand_equal_p (val, TYPE_MIN_VALUE (type), 0))
4449 return range_binop (MINUS_EXPR, NULL_TREE, val, 0, integer_one_node, 0);
4452 /* Return the successor of VAL in its type, handling the infinite case. */
4455 range_successor (tree val)
4457 tree type = TREE_TYPE (val);
4459 if (INTEGRAL_TYPE_P (type)
4460 && operand_equal_p (val, TYPE_MAX_VALUE (type), 0))
4463 return range_binop (PLUS_EXPR, NULL_TREE, val, 0, integer_one_node, 0);
4466 /* Given two ranges, see if we can merge them into one. Return 1 if we
4467 can, 0 if we can't. Set the output range into the specified parameters. */
4470 merge_ranges (int *pin_p, tree *plow, tree *phigh, int in0_p, tree low0,
4471 tree high0, int in1_p, tree low1, tree high1)
4479 int lowequal = ((low0 == 0 && low1 == 0)
4480 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
4481 low0, 0, low1, 0)));
4482 int highequal = ((high0 == 0 && high1 == 0)
4483 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
4484 high0, 1, high1, 1)));
4486 /* Make range 0 be the range that starts first, or ends last if they
4487 start at the same value. Swap them if it isn't. */
4488 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
4491 && integer_onep (range_binop (GT_EXPR, integer_type_node,
4492 high1, 1, high0, 1))))
4494 temp = in0_p, in0_p = in1_p, in1_p = temp;
4495 tem = low0, low0 = low1, low1 = tem;
4496 tem = high0, high0 = high1, high1 = tem;
4499 /* Now flag two cases, whether the ranges are disjoint or whether the
4500 second range is totally subsumed in the first. Note that the tests
4501 below are simplified by the ones above. */
4502 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
4503 high0, 1, low1, 0));
4504 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
4505 high1, 1, high0, 1));
4507 /* We now have four cases, depending on whether we are including or
4508 excluding the two ranges. */
4511 /* If they don't overlap, the result is false. If the second range
4512 is a subset it is the result. Otherwise, the range is from the start
4513 of the second to the end of the first. */
4515 in_p = 0, low = high = 0;
4517 in_p = 1, low = low1, high = high1;
4519 in_p = 1, low = low1, high = high0;
4522 else if (in0_p && ! in1_p)
4524 /* If they don't overlap, the result is the first range. If they are
4525 equal, the result is false. If the second range is a subset of the
4526 first, and the ranges begin at the same place, we go from just after
4527 the end of the second range to the end of the first. If the second
4528 range is not a subset of the first, or if it is a subset and both
4529 ranges end at the same place, the range starts at the start of the
4530 first range and ends just before the second range.
4531 Otherwise, we can't describe this as a single range. */
4533 in_p = 1, low = low0, high = high0;
4534 else if (lowequal && highequal)
4535 in_p = 0, low = high = 0;
4536 else if (subset && lowequal)
4538 low = range_successor (high1);
4542 else if (! subset || highequal)
4545 high = range_predecessor (low1);
4552 else if (! in0_p && in1_p)
4554 /* If they don't overlap, the result is the second range. If the second
4555 is a subset of the first, the result is false. Otherwise,
4556 the range starts just after the first range and ends at the
4557 end of the second. */
4559 in_p = 1, low = low1, high = high1;
4560 else if (subset || highequal)
4561 in_p = 0, low = high = 0;
4564 low = range_successor (high0);
4572 /* The case where we are excluding both ranges. Here the complex case
4573 is if they don't overlap. In that case, the only time we have a
4574 range is if they are adjacent. If the second is a subset of the
4575 first, the result is the first. Otherwise, the range to exclude
4576 starts at the beginning of the first range and ends at the end of the
4580 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
4581 range_successor (high0),
4583 in_p = 0, low = low0, high = high1;
4586 /* Canonicalize - [min, x] into - [-, x]. */
4587 if (low0 && TREE_CODE (low0) == INTEGER_CST)
4588 switch (TREE_CODE (TREE_TYPE (low0)))
4591 if (TYPE_PRECISION (TREE_TYPE (low0))
4592 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (low0))))
4596 if (tree_int_cst_equal (low0,
4597 TYPE_MIN_VALUE (TREE_TYPE (low0))))
4601 if (TYPE_UNSIGNED (TREE_TYPE (low0))
4602 && integer_zerop (low0))
4609 /* Canonicalize - [x, max] into - [x, -]. */
4610 if (high1 && TREE_CODE (high1) == INTEGER_CST)
4611 switch (TREE_CODE (TREE_TYPE (high1)))
4614 if (TYPE_PRECISION (TREE_TYPE (high1))
4615 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (high1))))
4619 if (tree_int_cst_equal (high1,
4620 TYPE_MAX_VALUE (TREE_TYPE (high1))))
4624 if (TYPE_UNSIGNED (TREE_TYPE (high1))
4625 && integer_zerop (range_binop (PLUS_EXPR, NULL_TREE,
4627 integer_one_node, 1)))
4634 /* The ranges might be also adjacent between the maximum and
4635 minimum values of the given type. For
4636 - [{min,-}, x] and - [y, {max,-}] ranges where x + 1 < y
4637 return + [x + 1, y - 1]. */
4638 if (low0 == 0 && high1 == 0)
4640 low = range_successor (high0);
4641 high = range_predecessor (low1);
4642 if (low == 0 || high == 0)
4652 in_p = 0, low = low0, high = high0;
4654 in_p = 0, low = low0, high = high1;
4657 *pin_p = in_p, *plow = low, *phigh = high;
4662 /* Subroutine of fold, looking inside expressions of the form
4663 A op B ? A : C, where ARG0, ARG1 and ARG2 are the three operands
4664 of the COND_EXPR. This function is being used also to optimize
4665 A op B ? C : A, by reversing the comparison first.
4667 Return a folded expression whose code is not a COND_EXPR
4668 anymore, or NULL_TREE if no folding opportunity is found. */
4671 fold_cond_expr_with_comparison (tree type, tree arg0, tree arg1, tree arg2)
4673 enum tree_code comp_code = TREE_CODE (arg0);
4674 tree arg00 = TREE_OPERAND (arg0, 0);
4675 tree arg01 = TREE_OPERAND (arg0, 1);
4676 tree arg1_type = TREE_TYPE (arg1);
4682 /* If we have A op 0 ? A : -A, consider applying the following
4685 A == 0? A : -A same as -A
4686 A != 0? A : -A same as A
4687 A >= 0? A : -A same as abs (A)
4688 A > 0? A : -A same as abs (A)
4689 A <= 0? A : -A same as -abs (A)
4690 A < 0? A : -A same as -abs (A)
4692 None of these transformations work for modes with signed
4693 zeros. If A is +/-0, the first two transformations will
4694 change the sign of the result (from +0 to -0, or vice
4695 versa). The last four will fix the sign of the result,
4696 even though the original expressions could be positive or
4697 negative, depending on the sign of A.
4699 Note that all these transformations are correct if A is
4700 NaN, since the two alternatives (A and -A) are also NaNs. */
4701 if ((FLOAT_TYPE_P (TREE_TYPE (arg01))
4702 ? real_zerop (arg01)
4703 : integer_zerop (arg01))
4704 && ((TREE_CODE (arg2) == NEGATE_EXPR
4705 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
4706 /* In the case that A is of the form X-Y, '-A' (arg2) may
4707 have already been folded to Y-X, check for that. */
4708 || (TREE_CODE (arg1) == MINUS_EXPR
4709 && TREE_CODE (arg2) == MINUS_EXPR
4710 && operand_equal_p (TREE_OPERAND (arg1, 0),
4711 TREE_OPERAND (arg2, 1), 0)
4712 && operand_equal_p (TREE_OPERAND (arg1, 1),
4713 TREE_OPERAND (arg2, 0), 0))))
4718 tem = fold_convert (arg1_type, arg1);
4719 return pedantic_non_lvalue (fold_convert (type, negate_expr (tem)));
4722 return pedantic_non_lvalue (fold_convert (type, arg1));
4725 if (flag_trapping_math)
4730 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
4731 arg1 = fold_convert (lang_hooks.types.signed_type
4732 (TREE_TYPE (arg1)), arg1);
4733 tem = fold_build1 (ABS_EXPR, TREE_TYPE (arg1), arg1);
4734 return pedantic_non_lvalue (fold_convert (type, tem));
4737 if (flag_trapping_math)
4741 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
4742 arg1 = fold_convert (lang_hooks.types.signed_type
4743 (TREE_TYPE (arg1)), arg1);
4744 tem = fold_build1 (ABS_EXPR, TREE_TYPE (arg1), arg1);
4745 return negate_expr (fold_convert (type, tem));
4747 gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
4751 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
4752 A == 0 ? A : 0 is always 0 unless A is -0. Note that
4753 both transformations are correct when A is NaN: A != 0
4754 is then true, and A == 0 is false. */
4756 if (integer_zerop (arg01) && integer_zerop (arg2))
4758 if (comp_code == NE_EXPR)
4759 return pedantic_non_lvalue (fold_convert (type, arg1));
4760 else if (comp_code == EQ_EXPR)
4761 return build_int_cst (type, 0);
4764 /* Try some transformations of A op B ? A : B.
4766 A == B? A : B same as B
4767 A != B? A : B same as A
4768 A >= B? A : B same as max (A, B)
4769 A > B? A : B same as max (B, A)
4770 A <= B? A : B same as min (A, B)
4771 A < B? A : B same as min (B, A)
4773 As above, these transformations don't work in the presence
4774 of signed zeros. For example, if A and B are zeros of
4775 opposite sign, the first two transformations will change
4776 the sign of the result. In the last four, the original
4777 expressions give different results for (A=+0, B=-0) and
4778 (A=-0, B=+0), but the transformed expressions do not.
4780 The first two transformations are correct if either A or B
4781 is a NaN. In the first transformation, the condition will
4782 be false, and B will indeed be chosen. In the case of the
4783 second transformation, the condition A != B will be true,
4784 and A will be chosen.
4786 The conversions to max() and min() are not correct if B is
4787 a number and A is not. The conditions in the original
4788 expressions will be false, so all four give B. The min()
4789 and max() versions would give a NaN instead. */
4790 if (operand_equal_for_comparison_p (arg01, arg2, arg00)
4791 /* Avoid these transformations if the COND_EXPR may be used
4792 as an lvalue in the C++ front-end. PR c++/19199. */
4794 || (strcmp (lang_hooks.name, "GNU C++") != 0
4795 && strcmp (lang_hooks.name, "GNU Objective-C++") != 0)
4796 || ! maybe_lvalue_p (arg1)
4797 || ! maybe_lvalue_p (arg2)))
4799 tree comp_op0 = arg00;
4800 tree comp_op1 = arg01;
4801 tree comp_type = TREE_TYPE (comp_op0);
4803 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
4804 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
4814 return pedantic_non_lvalue (fold_convert (type, arg2));
4816 return pedantic_non_lvalue (fold_convert (type, arg1));
4821 /* In C++ a ?: expression can be an lvalue, so put the
4822 operand which will be used if they are equal first
4823 so that we can convert this back to the
4824 corresponding COND_EXPR. */
4825 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4827 comp_op0 = fold_convert (comp_type, comp_op0);
4828 comp_op1 = fold_convert (comp_type, comp_op1);
4829 tem = (comp_code == LE_EXPR || comp_code == UNLE_EXPR)
4830 ? fold_build2 (MIN_EXPR, comp_type, comp_op0, comp_op1)
4831 : fold_build2 (MIN_EXPR, comp_type, comp_op1, comp_op0);
4832 return pedantic_non_lvalue (fold_convert (type, tem));
4839 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4841 comp_op0 = fold_convert (comp_type, comp_op0);
4842 comp_op1 = fold_convert (comp_type, comp_op1);
4843 tem = (comp_code == GE_EXPR || comp_code == UNGE_EXPR)
4844 ? fold_build2 (MAX_EXPR, comp_type, comp_op0, comp_op1)
4845 : fold_build2 (MAX_EXPR, comp_type, comp_op1, comp_op0);
4846 return pedantic_non_lvalue (fold_convert (type, tem));
4850 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4851 return pedantic_non_lvalue (fold_convert (type, arg2));
4854 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4855 return pedantic_non_lvalue (fold_convert (type, arg1));
4858 gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
4863 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
4864 we might still be able to simplify this. For example,
4865 if C1 is one less or one more than C2, this might have started
4866 out as a MIN or MAX and been transformed by this function.
4867 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
4869 if (INTEGRAL_TYPE_P (type)
4870 && TREE_CODE (arg01) == INTEGER_CST
4871 && TREE_CODE (arg2) == INTEGER_CST)
4875 /* We can replace A with C1 in this case. */
4876 arg1 = fold_convert (type, arg01);
4877 return fold_build3 (COND_EXPR, type, arg0, arg1, arg2);
4880 /* If C1 is C2 + 1, this is min(A, C2). */
4881 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
4883 && operand_equal_p (arg01,
4884 const_binop (PLUS_EXPR, arg2,
4885 build_int_cst (type, 1), 0),
4887 return pedantic_non_lvalue (fold_build2 (MIN_EXPR,
4892 /* If C1 is C2 - 1, this is min(A, C2). */
4893 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
4895 && operand_equal_p (arg01,
4896 const_binop (MINUS_EXPR, arg2,
4897 build_int_cst (type, 1), 0),
4899 return pedantic_non_lvalue (fold_build2 (MIN_EXPR,
4904 /* If C1 is C2 - 1, this is max(A, C2). */
4905 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
4907 && operand_equal_p (arg01,
4908 const_binop (MINUS_EXPR, arg2,
4909 build_int_cst (type, 1), 0),
4911 return pedantic_non_lvalue (fold_build2 (MAX_EXPR,
4916 /* If C1 is C2 + 1, this is max(A, C2). */
4917 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
4919 && operand_equal_p (arg01,
4920 const_binop (PLUS_EXPR, arg2,
4921 build_int_cst (type, 1), 0),
4923 return pedantic_non_lvalue (fold_build2 (MAX_EXPR,
4937 #ifndef LOGICAL_OP_NON_SHORT_CIRCUIT
4938 #define LOGICAL_OP_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
4941 /* EXP is some logical combination of boolean tests. See if we can
4942 merge it into some range test. Return the new tree if so. */
4945 fold_range_test (enum tree_code code, tree type, tree op0, tree op1)
4947 int or_op = (code == TRUTH_ORIF_EXPR
4948 || code == TRUTH_OR_EXPR);
4949 int in0_p, in1_p, in_p;
4950 tree low0, low1, low, high0, high1, high;
4951 bool strict_overflow_p = false;
4952 tree lhs = make_range (op0, &in0_p, &low0, &high0, &strict_overflow_p);
4953 tree rhs = make_range (op1, &in1_p, &low1, &high1, &strict_overflow_p);
4955 const char * const warnmsg = G_("assuming signed overflow does not occur "
4956 "when simplifying range test");
4958 /* If this is an OR operation, invert both sides; we will invert
4959 again at the end. */
4961 in0_p = ! in0_p, in1_p = ! in1_p;
4963 /* If both expressions are the same, if we can merge the ranges, and we
4964 can build the range test, return it or it inverted. If one of the
4965 ranges is always true or always false, consider it to be the same
4966 expression as the other. */
4967 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
4968 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
4970 && 0 != (tem = (build_range_check (type,
4972 : rhs != 0 ? rhs : integer_zero_node,
4975 if (strict_overflow_p)
4976 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
4977 return or_op ? invert_truthvalue (tem) : tem;
4980 /* On machines where the branch cost is expensive, if this is a
4981 short-circuited branch and the underlying object on both sides
4982 is the same, make a non-short-circuit operation. */
4983 else if (LOGICAL_OP_NON_SHORT_CIRCUIT
4984 && lhs != 0 && rhs != 0
4985 && (code == TRUTH_ANDIF_EXPR
4986 || code == TRUTH_ORIF_EXPR)
4987 && operand_equal_p (lhs, rhs, 0))
4989 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
4990 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
4991 which cases we can't do this. */
4992 if (simple_operand_p (lhs))
4993 return build2 (code == TRUTH_ANDIF_EXPR
4994 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
4997 else if (lang_hooks.decls.global_bindings_p () == 0
4998 && ! CONTAINS_PLACEHOLDER_P (lhs))
5000 tree common = save_expr (lhs);
5002 if (0 != (lhs = build_range_check (type, common,
5003 or_op ? ! in0_p : in0_p,
5005 && (0 != (rhs = build_range_check (type, common,
5006 or_op ? ! in1_p : in1_p,
5009 if (strict_overflow_p)
5010 fold_overflow_warning (warnmsg,
5011 WARN_STRICT_OVERFLOW_COMPARISON);
5012 return build2 (code == TRUTH_ANDIF_EXPR
5013 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
5022 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
5023 bit value. Arrange things so the extra bits will be set to zero if and
5024 only if C is signed-extended to its full width. If MASK is nonzero,
5025 it is an INTEGER_CST that should be AND'ed with the extra bits. */
5028 unextend (tree c, int p, int unsignedp, tree mask)
5030 tree type = TREE_TYPE (c);
5031 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
5034 if (p == modesize || unsignedp)
5037 /* We work by getting just the sign bit into the low-order bit, then
5038 into the high-order bit, then sign-extend. We then XOR that value
5040 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
5041 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
5043 /* We must use a signed type in order to get an arithmetic right shift.
5044 However, we must also avoid introducing accidental overflows, so that
5045 a subsequent call to integer_zerop will work. Hence we must
5046 do the type conversion here. At this point, the constant is either
5047 zero or one, and the conversion to a signed type can never overflow.
5048 We could get an overflow if this conversion is done anywhere else. */
5049 if (TYPE_UNSIGNED (type))
5050 temp = fold_convert (lang_hooks.types.signed_type (type), temp);
5052 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
5053 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
5055 temp = const_binop (BIT_AND_EXPR, temp,
5056 fold_convert (TREE_TYPE (c), mask), 0);
5057 /* If necessary, convert the type back to match the type of C. */
5058 if (TYPE_UNSIGNED (type))
5059 temp = fold_convert (type, temp);
5061 return fold_convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
5064 /* Find ways of folding logical expressions of LHS and RHS:
5065 Try to merge two comparisons to the same innermost item.
5066 Look for range tests like "ch >= '0' && ch <= '9'".
5067 Look for combinations of simple terms on machines with expensive branches
5068 and evaluate the RHS unconditionally.
5070 For example, if we have p->a == 2 && p->b == 4 and we can make an
5071 object large enough to span both A and B, we can do this with a comparison
5072 against the object ANDed with the a mask.
5074 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
5075 operations to do this with one comparison.
5077 We check for both normal comparisons and the BIT_AND_EXPRs made this by
5078 function and the one above.
5080 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
5081 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
5083 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
5086 We return the simplified tree or 0 if no optimization is possible. */
5089 fold_truthop (enum tree_code code, tree truth_type, tree lhs, tree rhs)
5091 /* If this is the "or" of two comparisons, we can do something if
5092 the comparisons are NE_EXPR. If this is the "and", we can do something
5093 if the comparisons are EQ_EXPR. I.e.,
5094 (a->b == 2 && a->c == 4) can become (a->new == NEW).
5096 WANTED_CODE is this operation code. For single bit fields, we can
5097 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
5098 comparison for one-bit fields. */
5100 enum tree_code wanted_code;
5101 enum tree_code lcode, rcode;
5102 tree ll_arg, lr_arg, rl_arg, rr_arg;
5103 tree ll_inner, lr_inner, rl_inner, rr_inner;
5104 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
5105 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
5106 HOST_WIDE_INT xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
5107 HOST_WIDE_INT lnbitsize, lnbitpos, rnbitsize, rnbitpos;
5108 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
5109 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
5110 enum machine_mode lnmode, rnmode;
5111 tree ll_mask, lr_mask, rl_mask, rr_mask;
5112 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
5113 tree l_const, r_const;
5114 tree lntype, rntype, result;
5115 int first_bit, end_bit;
5117 tree orig_lhs = lhs, orig_rhs = rhs;
5118 enum tree_code orig_code = code;
5120 /* Start by getting the comparison codes. Fail if anything is volatile.
5121 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
5122 it were surrounded with a NE_EXPR. */
5124 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
5127 lcode = TREE_CODE (lhs);
5128 rcode = TREE_CODE (rhs);
5130 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
5132 lhs = build2 (NE_EXPR, truth_type, lhs,
5133 build_int_cst (TREE_TYPE (lhs), 0));
5137 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
5139 rhs = build2 (NE_EXPR, truth_type, rhs,
5140 build_int_cst (TREE_TYPE (rhs), 0));
5144 if (TREE_CODE_CLASS (lcode) != tcc_comparison
5145 || TREE_CODE_CLASS (rcode) != tcc_comparison)
5148 ll_arg = TREE_OPERAND (lhs, 0);
5149 lr_arg = TREE_OPERAND (lhs, 1);
5150 rl_arg = TREE_OPERAND (rhs, 0);
5151 rr_arg = TREE_OPERAND (rhs, 1);
5153 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
5154 if (simple_operand_p (ll_arg)
5155 && simple_operand_p (lr_arg))
5158 if (operand_equal_p (ll_arg, rl_arg, 0)
5159 && operand_equal_p (lr_arg, rr_arg, 0))
5161 result = combine_comparisons (code, lcode, rcode,
5162 truth_type, ll_arg, lr_arg);
5166 else if (operand_equal_p (ll_arg, rr_arg, 0)
5167 && operand_equal_p (lr_arg, rl_arg, 0))
5169 result = combine_comparisons (code, lcode,
5170 swap_tree_comparison (rcode),
5171 truth_type, ll_arg, lr_arg);
5177 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
5178 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
5180 /* If the RHS can be evaluated unconditionally and its operands are
5181 simple, it wins to evaluate the RHS unconditionally on machines
5182 with expensive branches. In this case, this isn't a comparison
5183 that can be merged. Avoid doing this if the RHS is a floating-point
5184 comparison since those can trap. */
5186 if (BRANCH_COST >= 2
5187 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
5188 && simple_operand_p (rl_arg)
5189 && simple_operand_p (rr_arg))
5191 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
5192 if (code == TRUTH_OR_EXPR
5193 && lcode == NE_EXPR && integer_zerop (lr_arg)
5194 && rcode == NE_EXPR && integer_zerop (rr_arg)
5195 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
5196 return build2 (NE_EXPR, truth_type,
5197 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
5199 build_int_cst (TREE_TYPE (ll_arg), 0));
5201 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
5202 if (code == TRUTH_AND_EXPR
5203 && lcode == EQ_EXPR && integer_zerop (lr_arg)
5204 && rcode == EQ_EXPR && integer_zerop (rr_arg)
5205 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
5206 return build2 (EQ_EXPR, truth_type,
5207 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
5209 build_int_cst (TREE_TYPE (ll_arg), 0));
5211 if (LOGICAL_OP_NON_SHORT_CIRCUIT)
5213 if (code != orig_code || lhs != orig_lhs || rhs != orig_rhs)
5214 return build2 (code, truth_type, lhs, rhs);
5219 /* See if the comparisons can be merged. Then get all the parameters for
5222 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
5223 || (rcode != EQ_EXPR && rcode != NE_EXPR))
5227 ll_inner = decode_field_reference (ll_arg,
5228 &ll_bitsize, &ll_bitpos, &ll_mode,
5229 &ll_unsignedp, &volatilep, &ll_mask,
5231 lr_inner = decode_field_reference (lr_arg,
5232 &lr_bitsize, &lr_bitpos, &lr_mode,
5233 &lr_unsignedp, &volatilep, &lr_mask,
5235 rl_inner = decode_field_reference (rl_arg,
5236 &rl_bitsize, &rl_bitpos, &rl_mode,
5237 &rl_unsignedp, &volatilep, &rl_mask,
5239 rr_inner = decode_field_reference (rr_arg,
5240 &rr_bitsize, &rr_bitpos, &rr_mode,
5241 &rr_unsignedp, &volatilep, &rr_mask,
5244 /* It must be true that the inner operation on the lhs of each
5245 comparison must be the same if we are to be able to do anything.
5246 Then see if we have constants. If not, the same must be true for
5248 if (volatilep || ll_inner == 0 || rl_inner == 0
5249 || ! operand_equal_p (ll_inner, rl_inner, 0))
5252 if (TREE_CODE (lr_arg) == INTEGER_CST
5253 && TREE_CODE (rr_arg) == INTEGER_CST)
5254 l_const = lr_arg, r_const = rr_arg;
5255 else if (lr_inner == 0 || rr_inner == 0
5256 || ! operand_equal_p (lr_inner, rr_inner, 0))
5259 l_const = r_const = 0;
5261 /* If either comparison code is not correct for our logical operation,
5262 fail. However, we can convert a one-bit comparison against zero into
5263 the opposite comparison against that bit being set in the field. */
5265 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
5266 if (lcode != wanted_code)
5268 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
5270 /* Make the left operand unsigned, since we are only interested
5271 in the value of one bit. Otherwise we are doing the wrong
5280 /* This is analogous to the code for l_const above. */
5281 if (rcode != wanted_code)
5283 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
5292 /* See if we can find a mode that contains both fields being compared on
5293 the left. If we can't, fail. Otherwise, update all constants and masks
5294 to be relative to a field of that size. */
5295 first_bit = MIN (ll_bitpos, rl_bitpos);
5296 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
5297 lnmode = get_best_mode (end_bit - first_bit, first_bit,
5298 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
5300 if (lnmode == VOIDmode)
5303 lnbitsize = GET_MODE_BITSIZE (lnmode);
5304 lnbitpos = first_bit & ~ (lnbitsize - 1);
5305 lntype = lang_hooks.types.type_for_size (lnbitsize, 1);
5306 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
5308 if (BYTES_BIG_ENDIAN)
5310 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
5311 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
5314 ll_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, ll_mask),
5315 size_int (xll_bitpos), 0);
5316 rl_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, rl_mask),
5317 size_int (xrl_bitpos), 0);
5321 l_const = fold_convert (lntype, l_const);
5322 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
5323 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
5324 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
5325 fold_build1 (BIT_NOT_EXPR,
5329 warning (0, "comparison is always %d", wanted_code == NE_EXPR);
5331 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
5336 r_const = fold_convert (lntype, r_const);
5337 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
5338 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
5339 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
5340 fold_build1 (BIT_NOT_EXPR,
5344 warning (0, "comparison is always %d", wanted_code == NE_EXPR);
5346 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
5350 /* If the right sides are not constant, do the same for it. Also,
5351 disallow this optimization if a size or signedness mismatch occurs
5352 between the left and right sides. */
5355 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
5356 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
5357 /* Make sure the two fields on the right
5358 correspond to the left without being swapped. */
5359 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
5362 first_bit = MIN (lr_bitpos, rr_bitpos);
5363 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
5364 rnmode = get_best_mode (end_bit - first_bit, first_bit,
5365 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
5367 if (rnmode == VOIDmode)
5370 rnbitsize = GET_MODE_BITSIZE (rnmode);
5371 rnbitpos = first_bit & ~ (rnbitsize - 1);
5372 rntype = lang_hooks.types.type_for_size (rnbitsize, 1);
5373 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
5375 if (BYTES_BIG_ENDIAN)
5377 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
5378 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
5381 lr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, lr_mask),
5382 size_int (xlr_bitpos), 0);
5383 rr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, rr_mask),
5384 size_int (xrr_bitpos), 0);
5386 /* Make a mask that corresponds to both fields being compared.
5387 Do this for both items being compared. If the operands are the
5388 same size and the bits being compared are in the same position
5389 then we can do this by masking both and comparing the masked
5391 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
5392 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
5393 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
5395 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
5396 ll_unsignedp || rl_unsignedp);
5397 if (! all_ones_mask_p (ll_mask, lnbitsize))
5398 lhs = build2 (BIT_AND_EXPR, lntype, lhs, ll_mask);
5400 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
5401 lr_unsignedp || rr_unsignedp);
5402 if (! all_ones_mask_p (lr_mask, rnbitsize))
5403 rhs = build2 (BIT_AND_EXPR, rntype, rhs, lr_mask);
5405 return build2 (wanted_code, truth_type, lhs, rhs);
5408 /* There is still another way we can do something: If both pairs of
5409 fields being compared are adjacent, we may be able to make a wider
5410 field containing them both.
5412 Note that we still must mask the lhs/rhs expressions. Furthermore,
5413 the mask must be shifted to account for the shift done by
5414 make_bit_field_ref. */
5415 if ((ll_bitsize + ll_bitpos == rl_bitpos
5416 && lr_bitsize + lr_bitpos == rr_bitpos)
5417 || (ll_bitpos == rl_bitpos + rl_bitsize
5418 && lr_bitpos == rr_bitpos + rr_bitsize))
5422 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
5423 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
5424 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
5425 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
5427 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
5428 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
5429 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
5430 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
5432 /* Convert to the smaller type before masking out unwanted bits. */
5434 if (lntype != rntype)
5436 if (lnbitsize > rnbitsize)
5438 lhs = fold_convert (rntype, lhs);
5439 ll_mask = fold_convert (rntype, ll_mask);
5442 else if (lnbitsize < rnbitsize)
5444 rhs = fold_convert (lntype, rhs);
5445 lr_mask = fold_convert (lntype, lr_mask);
5450 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
5451 lhs = build2 (BIT_AND_EXPR, type, lhs, ll_mask);
5453 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
5454 rhs = build2 (BIT_AND_EXPR, type, rhs, lr_mask);
5456 return build2 (wanted_code, truth_type, lhs, rhs);
5462 /* Handle the case of comparisons with constants. If there is something in
5463 common between the masks, those bits of the constants must be the same.
5464 If not, the condition is always false. Test for this to avoid generating
5465 incorrect code below. */
5466 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
5467 if (! integer_zerop (result)
5468 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
5469 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
5471 if (wanted_code == NE_EXPR)
5473 warning (0, "%<or%> of unmatched not-equal tests is always 1");
5474 return constant_boolean_node (true, truth_type);
5478 warning (0, "%<and%> of mutually exclusive equal-tests is always 0");
5479 return constant_boolean_node (false, truth_type);
5483 /* Construct the expression we will return. First get the component
5484 reference we will make. Unless the mask is all ones the width of
5485 that field, perform the mask operation. Then compare with the
5487 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
5488 ll_unsignedp || rl_unsignedp);
5490 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
5491 if (! all_ones_mask_p (ll_mask, lnbitsize))
5492 result = build2 (BIT_AND_EXPR, lntype, result, ll_mask);
5494 return build2 (wanted_code, truth_type, result,
5495 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
5498 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
5502 optimize_minmax_comparison (enum tree_code code, tree type, tree op0, tree op1)
5505 enum tree_code op_code;
5506 tree comp_const = op1;
5508 int consts_equal, consts_lt;
5511 STRIP_SIGN_NOPS (arg0);
5513 op_code = TREE_CODE (arg0);
5514 minmax_const = TREE_OPERAND (arg0, 1);
5515 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
5516 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
5517 inner = TREE_OPERAND (arg0, 0);
5519 /* If something does not permit us to optimize, return the original tree. */
5520 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
5521 || TREE_CODE (comp_const) != INTEGER_CST
5522 || TREE_OVERFLOW (comp_const)
5523 || TREE_CODE (minmax_const) != INTEGER_CST
5524 || TREE_OVERFLOW (minmax_const))
5527 /* Now handle all the various comparison codes. We only handle EQ_EXPR
5528 and GT_EXPR, doing the rest with recursive calls using logical
5532 case NE_EXPR: case LT_EXPR: case LE_EXPR:
5534 tree tem = optimize_minmax_comparison (invert_tree_comparison (code, false),
5537 return invert_truthvalue (tem);
5543 fold_build2 (TRUTH_ORIF_EXPR, type,
5544 optimize_minmax_comparison
5545 (EQ_EXPR, type, arg0, comp_const),
5546 optimize_minmax_comparison
5547 (GT_EXPR, type, arg0, comp_const));
5550 if (op_code == MAX_EXPR && consts_equal)
5551 /* MAX (X, 0) == 0 -> X <= 0 */
5552 return fold_build2 (LE_EXPR, type, inner, comp_const);
5554 else if (op_code == MAX_EXPR && consts_lt)
5555 /* MAX (X, 0) == 5 -> X == 5 */
5556 return fold_build2 (EQ_EXPR, type, inner, comp_const);
5558 else if (op_code == MAX_EXPR)
5559 /* MAX (X, 0) == -1 -> false */
5560 return omit_one_operand (type, integer_zero_node, inner);
5562 else if (consts_equal)
5563 /* MIN (X, 0) == 0 -> X >= 0 */
5564 return fold_build2 (GE_EXPR, type, inner, comp_const);
5567 /* MIN (X, 0) == 5 -> false */
5568 return omit_one_operand (type, integer_zero_node, inner);
5571 /* MIN (X, 0) == -1 -> X == -1 */
5572 return fold_build2 (EQ_EXPR, type, inner, comp_const);
5575 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
5576 /* MAX (X, 0) > 0 -> X > 0
5577 MAX (X, 0) > 5 -> X > 5 */
5578 return fold_build2 (GT_EXPR, type, inner, comp_const);
5580 else if (op_code == MAX_EXPR)
5581 /* MAX (X, 0) > -1 -> true */
5582 return omit_one_operand (type, integer_one_node, inner);
5584 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
5585 /* MIN (X, 0) > 0 -> false
5586 MIN (X, 0) > 5 -> false */
5587 return omit_one_operand (type, integer_zero_node, inner);
5590 /* MIN (X, 0) > -1 -> X > -1 */
5591 return fold_build2 (GT_EXPR, type, inner, comp_const);
5598 /* T is an integer expression that is being multiplied, divided, or taken a
5599 modulus (CODE says which and what kind of divide or modulus) by a
5600 constant C. See if we can eliminate that operation by folding it with
5601 other operations already in T. WIDE_TYPE, if non-null, is a type that
5602 should be used for the computation if wider than our type.
5604 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
5605 (X * 2) + (Y * 4). We must, however, be assured that either the original
5606 expression would not overflow or that overflow is undefined for the type
5607 in the language in question.
5609 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
5610 the machine has a multiply-accumulate insn or that this is part of an
5611 addressing calculation.
5613 If we return a non-null expression, it is an equivalent form of the
5614 original computation, but need not be in the original type.
5616 We set *STRICT_OVERFLOW_P to true if the return values depends on
5617 signed overflow being undefined. Otherwise we do not change
5618 *STRICT_OVERFLOW_P. */
5621 extract_muldiv (tree t, tree c, enum tree_code code, tree wide_type,
5622 bool *strict_overflow_p)
5624 /* To avoid exponential search depth, refuse to allow recursion past
5625 three levels. Beyond that (1) it's highly unlikely that we'll find
5626 something interesting and (2) we've probably processed it before
5627 when we built the inner expression. */
5636 ret = extract_muldiv_1 (t, c, code, wide_type, strict_overflow_p);
5643 extract_muldiv_1 (tree t, tree c, enum tree_code code, tree wide_type,
5644 bool *strict_overflow_p)
5646 tree type = TREE_TYPE (t);
5647 enum tree_code tcode = TREE_CODE (t);
5648 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
5649 > GET_MODE_SIZE (TYPE_MODE (type)))
5650 ? wide_type : type);
5652 int same_p = tcode == code;
5653 tree op0 = NULL_TREE, op1 = NULL_TREE;
5654 bool sub_strict_overflow_p;
5656 /* Don't deal with constants of zero here; they confuse the code below. */
5657 if (integer_zerop (c))
5660 if (TREE_CODE_CLASS (tcode) == tcc_unary)
5661 op0 = TREE_OPERAND (t, 0);
5663 if (TREE_CODE_CLASS (tcode) == tcc_binary)
5664 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
5666 /* Note that we need not handle conditional operations here since fold
5667 already handles those cases. So just do arithmetic here. */
5671 /* For a constant, we can always simplify if we are a multiply
5672 or (for divide and modulus) if it is a multiple of our constant. */
5673 if (code == MULT_EXPR
5674 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
5675 return const_binop (code, fold_convert (ctype, t),
5676 fold_convert (ctype, c), 0);
5679 case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
5680 /* If op0 is an expression ... */
5681 if ((COMPARISON_CLASS_P (op0)
5682 || UNARY_CLASS_P (op0)
5683 || BINARY_CLASS_P (op0)
5684 || VL_EXP_CLASS_P (op0)
5685 || EXPRESSION_CLASS_P (op0))
5686 /* ... and is unsigned, and its type is smaller than ctype,
5687 then we cannot pass through as widening. */
5688 && ((TYPE_UNSIGNED (TREE_TYPE (op0))
5689 && ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
5690 && TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
5691 && (GET_MODE_SIZE (TYPE_MODE (ctype))
5692 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
5693 /* ... or this is a truncation (t is narrower than op0),
5694 then we cannot pass through this narrowing. */
5695 || (GET_MODE_SIZE (TYPE_MODE (type))
5696 < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0))))
5697 /* ... or signedness changes for division or modulus,
5698 then we cannot pass through this conversion. */
5699 || (code != MULT_EXPR
5700 && (TYPE_UNSIGNED (ctype)
5701 != TYPE_UNSIGNED (TREE_TYPE (op0))))))
5704 /* Pass the constant down and see if we can make a simplification. If
5705 we can, replace this expression with the inner simplification for
5706 possible later conversion to our or some other type. */
5707 if ((t2 = fold_convert (TREE_TYPE (op0), c)) != 0
5708 && TREE_CODE (t2) == INTEGER_CST
5709 && !TREE_OVERFLOW (t2)
5710 && (0 != (t1 = extract_muldiv (op0, t2, code,
5712 ? ctype : NULL_TREE,
5713 strict_overflow_p))))
5718 /* If widening the type changes it from signed to unsigned, then we
5719 must avoid building ABS_EXPR itself as unsigned. */
5720 if (TYPE_UNSIGNED (ctype) && !TYPE_UNSIGNED (type))
5722 tree cstype = (*lang_hooks.types.signed_type) (ctype);
5723 if ((t1 = extract_muldiv (op0, c, code, cstype, strict_overflow_p))
5726 t1 = fold_build1 (tcode, cstype, fold_convert (cstype, t1));
5727 return fold_convert (ctype, t1);
5733 if ((t1 = extract_muldiv (op0, c, code, wide_type, strict_overflow_p))
5735 return fold_build1 (tcode, ctype, fold_convert (ctype, t1));
5738 case MIN_EXPR: case MAX_EXPR:
5739 /* If widening the type changes the signedness, then we can't perform
5740 this optimization as that changes the result. */
5741 if (TYPE_UNSIGNED (ctype) != TYPE_UNSIGNED (type))
5744 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
5745 sub_strict_overflow_p = false;
5746 if ((t1 = extract_muldiv (op0, c, code, wide_type,
5747 &sub_strict_overflow_p)) != 0
5748 && (t2 = extract_muldiv (op1, c, code, wide_type,
5749 &sub_strict_overflow_p)) != 0)
5751 if (tree_int_cst_sgn (c) < 0)
5752 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
5753 if (sub_strict_overflow_p)
5754 *strict_overflow_p = true;
5755 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
5756 fold_convert (ctype, t2));
5760 case LSHIFT_EXPR: case RSHIFT_EXPR:
5761 /* If the second operand is constant, this is a multiplication
5762 or floor division, by a power of two, so we can treat it that
5763 way unless the multiplier or divisor overflows. Signed
5764 left-shift overflow is implementation-defined rather than
5765 undefined in C90, so do not convert signed left shift into
5767 if (TREE_CODE (op1) == INTEGER_CST
5768 && (tcode == RSHIFT_EXPR || TYPE_UNSIGNED (TREE_TYPE (op0)))
5769 /* const_binop may not detect overflow correctly,
5770 so check for it explicitly here. */
5771 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
5772 && TREE_INT_CST_HIGH (op1) == 0
5773 && 0 != (t1 = fold_convert (ctype,
5774 const_binop (LSHIFT_EXPR,
5777 && !TREE_OVERFLOW (t1))
5778 return extract_muldiv (build2 (tcode == LSHIFT_EXPR
5779 ? MULT_EXPR : FLOOR_DIV_EXPR,
5780 ctype, fold_convert (ctype, op0), t1),
5781 c, code, wide_type, strict_overflow_p);
5784 case PLUS_EXPR: case MINUS_EXPR:
5785 /* See if we can eliminate the operation on both sides. If we can, we
5786 can return a new PLUS or MINUS. If we can't, the only remaining
5787 cases where we can do anything are if the second operand is a
5789 sub_strict_overflow_p = false;
5790 t1 = extract_muldiv (op0, c, code, wide_type, &sub_strict_overflow_p);
5791 t2 = extract_muldiv (op1, c, code, wide_type, &sub_strict_overflow_p);
5792 if (t1 != 0 && t2 != 0
5793 && (code == MULT_EXPR
5794 /* If not multiplication, we can only do this if both operands
5795 are divisible by c. */
5796 || (multiple_of_p (ctype, op0, c)
5797 && multiple_of_p (ctype, op1, c))))
5799 if (sub_strict_overflow_p)
5800 *strict_overflow_p = true;
5801 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
5802 fold_convert (ctype, t2));
5805 /* If this was a subtraction, negate OP1 and set it to be an addition.
5806 This simplifies the logic below. */
5807 if (tcode == MINUS_EXPR)
5808 tcode = PLUS_EXPR, op1 = negate_expr (op1);
5810 if (TREE_CODE (op1) != INTEGER_CST)
5813 /* If either OP1 or C are negative, this optimization is not safe for
5814 some of the division and remainder types while for others we need
5815 to change the code. */
5816 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
5818 if (code == CEIL_DIV_EXPR)
5819 code = FLOOR_DIV_EXPR;
5820 else if (code == FLOOR_DIV_EXPR)
5821 code = CEIL_DIV_EXPR;
5822 else if (code != MULT_EXPR
5823 && code != CEIL_MOD_EXPR && code != FLOOR_MOD_EXPR)
5827 /* If it's a multiply or a division/modulus operation of a multiple
5828 of our constant, do the operation and verify it doesn't overflow. */
5829 if (code == MULT_EXPR
5830 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5832 op1 = const_binop (code, fold_convert (ctype, op1),
5833 fold_convert (ctype, c), 0);
5834 /* We allow the constant to overflow with wrapping semantics. */
5836 || (TREE_OVERFLOW (op1) && !TYPE_OVERFLOW_WRAPS (ctype)))
5842 /* If we have an unsigned type is not a sizetype, we cannot widen
5843 the operation since it will change the result if the original
5844 computation overflowed. */
5845 if (TYPE_UNSIGNED (ctype)
5846 && ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
5850 /* If we were able to eliminate our operation from the first side,
5851 apply our operation to the second side and reform the PLUS. */
5852 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
5853 return fold_build2 (tcode, ctype, fold_convert (ctype, t1), op1);
5855 /* The last case is if we are a multiply. In that case, we can
5856 apply the distributive law to commute the multiply and addition
5857 if the multiplication of the constants doesn't overflow. */
5858 if (code == MULT_EXPR)
5859 return fold_build2 (tcode, ctype,
5860 fold_build2 (code, ctype,
5861 fold_convert (ctype, op0),
5862 fold_convert (ctype, c)),
5868 /* We have a special case here if we are doing something like
5869 (C * 8) % 4 since we know that's zero. */
5870 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
5871 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
5872 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
5873 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5874 return omit_one_operand (type, integer_zero_node, op0);
5876 /* ... fall through ... */
5878 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
5879 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
5880 /* If we can extract our operation from the LHS, do so and return a
5881 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
5882 do something only if the second operand is a constant. */
5884 && (t1 = extract_muldiv (op0, c, code, wide_type,
5885 strict_overflow_p)) != 0)
5886 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
5887 fold_convert (ctype, op1));
5888 else if (tcode == MULT_EXPR && code == MULT_EXPR
5889 && (t1 = extract_muldiv (op1, c, code, wide_type,
5890 strict_overflow_p)) != 0)
5891 return fold_build2 (tcode, ctype, fold_convert (ctype, op0),
5892 fold_convert (ctype, t1));
5893 else if (TREE_CODE (op1) != INTEGER_CST)
5896 /* If these are the same operation types, we can associate them
5897 assuming no overflow. */
5899 && 0 != (t1 = const_binop (MULT_EXPR, fold_convert (ctype, op1),
5900 fold_convert (ctype, c), 0))
5901 && !TREE_OVERFLOW (t1))
5902 return fold_build2 (tcode, ctype, fold_convert (ctype, op0), t1);
5904 /* If these operations "cancel" each other, we have the main
5905 optimizations of this pass, which occur when either constant is a
5906 multiple of the other, in which case we replace this with either an
5907 operation or CODE or TCODE.
5909 If we have an unsigned type that is not a sizetype, we cannot do
5910 this since it will change the result if the original computation
5912 if ((TYPE_OVERFLOW_UNDEFINED (ctype)
5913 || (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
5914 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
5915 || (tcode == MULT_EXPR
5916 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
5917 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR)))
5919 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5921 if (TYPE_OVERFLOW_UNDEFINED (ctype))
5922 *strict_overflow_p = true;
5923 return fold_build2 (tcode, ctype, fold_convert (ctype, op0),
5924 fold_convert (ctype,
5925 const_binop (TRUNC_DIV_EXPR,
5928 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
5930 if (TYPE_OVERFLOW_UNDEFINED (ctype))
5931 *strict_overflow_p = true;
5932 return fold_build2 (code, ctype, fold_convert (ctype, op0),
5933 fold_convert (ctype,
5934 const_binop (TRUNC_DIV_EXPR,
5947 /* Return a node which has the indicated constant VALUE (either 0 or
5948 1), and is of the indicated TYPE. */
5951 constant_boolean_node (int value, tree type)
5953 if (type == integer_type_node)
5954 return value ? integer_one_node : integer_zero_node;
5955 else if (type == boolean_type_node)
5956 return value ? boolean_true_node : boolean_false_node;
5958 return build_int_cst (type, value);
5962 /* Return true if expr looks like an ARRAY_REF and set base and
5963 offset to the appropriate trees. If there is no offset,
5964 offset is set to NULL_TREE. Base will be canonicalized to
5965 something you can get the element type from using
5966 TREE_TYPE (TREE_TYPE (base)). Offset will be the offset
5967 in bytes to the base. */
5970 extract_array_ref (tree expr, tree *base, tree *offset)
5972 /* One canonical form is a PLUS_EXPR with the first
5973 argument being an ADDR_EXPR with a possible NOP_EXPR
5975 if (TREE_CODE (expr) == PLUS_EXPR)
5977 tree op0 = TREE_OPERAND (expr, 0);
5978 tree inner_base, dummy1;
5979 /* Strip NOP_EXPRs here because the C frontends and/or
5980 folders present us (int *)&x.a + 4B possibly. */
5982 if (extract_array_ref (op0, &inner_base, &dummy1))
5985 if (dummy1 == NULL_TREE)
5986 *offset = TREE_OPERAND (expr, 1);
5988 *offset = fold_build2 (PLUS_EXPR, TREE_TYPE (expr),
5989 dummy1, TREE_OPERAND (expr, 1));
5993 /* Other canonical form is an ADDR_EXPR of an ARRAY_REF,
5994 which we transform into an ADDR_EXPR with appropriate
5995 offset. For other arguments to the ADDR_EXPR we assume
5996 zero offset and as such do not care about the ADDR_EXPR
5997 type and strip possible nops from it. */
5998 else if (TREE_CODE (expr) == ADDR_EXPR)
6000 tree op0 = TREE_OPERAND (expr, 0);
6001 if (TREE_CODE (op0) == ARRAY_REF)
6003 tree idx = TREE_OPERAND (op0, 1);
6004 *base = TREE_OPERAND (op0, 0);
6005 *offset = fold_build2 (MULT_EXPR, TREE_TYPE (idx), idx,
6006 array_ref_element_size (op0));
6010 /* Handle array-to-pointer decay as &a. */
6011 if (TREE_CODE (TREE_TYPE (op0)) == ARRAY_TYPE)
6012 *base = TREE_OPERAND (expr, 0);
6015 *offset = NULL_TREE;
6019 /* The next canonical form is a VAR_DECL with POINTER_TYPE. */
6020 else if (SSA_VAR_P (expr)
6021 && TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
6024 *offset = NULL_TREE;
6032 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
6033 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
6034 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
6035 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
6036 COND is the first argument to CODE; otherwise (as in the example
6037 given here), it is the second argument. TYPE is the type of the
6038 original expression. Return NULL_TREE if no simplification is
6042 fold_binary_op_with_conditional_arg (enum tree_code code,
6043 tree type, tree op0, tree op1,
6044 tree cond, tree arg, int cond_first_p)
6046 tree cond_type = cond_first_p ? TREE_TYPE (op0) : TREE_TYPE (op1);
6047 tree arg_type = cond_first_p ? TREE_TYPE (op1) : TREE_TYPE (op0);
6048 tree test, true_value, false_value;
6049 tree lhs = NULL_TREE;
6050 tree rhs = NULL_TREE;
6052 /* This transformation is only worthwhile if we don't have to wrap
6053 arg in a SAVE_EXPR, and the operation can be simplified on at least
6054 one of the branches once its pushed inside the COND_EXPR. */
6055 if (!TREE_CONSTANT (arg))
6058 if (TREE_CODE (cond) == COND_EXPR)
6060 test = TREE_OPERAND (cond, 0);
6061 true_value = TREE_OPERAND (cond, 1);
6062 false_value = TREE_OPERAND (cond, 2);
6063 /* If this operand throws an expression, then it does not make
6064 sense to try to perform a logical or arithmetic operation
6066 if (VOID_TYPE_P (TREE_TYPE (true_value)))
6068 if (VOID_TYPE_P (TREE_TYPE (false_value)))
6073 tree testtype = TREE_TYPE (cond);
6075 true_value = constant_boolean_node (true, testtype);
6076 false_value = constant_boolean_node (false, testtype);
6079 arg = fold_convert (arg_type, arg);
6082 true_value = fold_convert (cond_type, true_value);
6084 lhs = fold_build2 (code, type, true_value, arg);
6086 lhs = fold_build2 (code, type, arg, true_value);
6090 false_value = fold_convert (cond_type, false_value);
6092 rhs = fold_build2 (code, type, false_value, arg);
6094 rhs = fold_build2 (code, type, arg, false_value);
6097 test = fold_build3 (COND_EXPR, type, test, lhs, rhs);
6098 return fold_convert (type, test);
6102 /* Subroutine of fold() that checks for the addition of +/- 0.0.
6104 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
6105 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
6106 ADDEND is the same as X.
6108 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
6109 and finite. The problematic cases are when X is zero, and its mode
6110 has signed zeros. In the case of rounding towards -infinity,
6111 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
6112 modes, X + 0 is not the same as X because -0 + 0 is 0. */
6115 fold_real_zero_addition_p (tree type, tree addend, int negate)
6117 if (!real_zerop (addend))
6120 /* Don't allow the fold with -fsignaling-nans. */
6121 if (HONOR_SNANS (TYPE_MODE (type)))
6124 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
6125 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
6128 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
6129 if (TREE_CODE (addend) == REAL_CST
6130 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
6133 /* The mode has signed zeros, and we have to honor their sign.
6134 In this situation, there is only one case we can return true for.
6135 X - 0 is the same as X unless rounding towards -infinity is
6137 return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
6140 /* Subroutine of fold() that checks comparisons of built-in math
6141 functions against real constants.
6143 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
6144 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
6145 is the type of the result and ARG0 and ARG1 are the operands of the
6146 comparison. ARG1 must be a TREE_REAL_CST.
6148 The function returns the constant folded tree if a simplification
6149 can be made, and NULL_TREE otherwise. */
6152 fold_mathfn_compare (enum built_in_function fcode, enum tree_code code,
6153 tree type, tree arg0, tree arg1)
6157 if (BUILTIN_SQRT_P (fcode))
6159 tree arg = CALL_EXPR_ARG (arg0, 0);
6160 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg0));
6162 c = TREE_REAL_CST (arg1);
6163 if (REAL_VALUE_NEGATIVE (c))
6165 /* sqrt(x) < y is always false, if y is negative. */
6166 if (code == EQ_EXPR || code == LT_EXPR || code == LE_EXPR)
6167 return omit_one_operand (type, integer_zero_node, arg);
6169 /* sqrt(x) > y is always true, if y is negative and we
6170 don't care about NaNs, i.e. negative values of x. */
6171 if (code == NE_EXPR || !HONOR_NANS (mode))
6172 return omit_one_operand (type, integer_one_node, arg);
6174 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
6175 return fold_build2 (GE_EXPR, type, arg,
6176 build_real (TREE_TYPE (arg), dconst0));
6178 else if (code == GT_EXPR || code == GE_EXPR)
6182 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
6183 real_convert (&c2, mode, &c2);
6185 if (REAL_VALUE_ISINF (c2))
6187 /* sqrt(x) > y is x == +Inf, when y is very large. */
6188 if (HONOR_INFINITIES (mode))
6189 return fold_build2 (EQ_EXPR, type, arg,
6190 build_real (TREE_TYPE (arg), c2));
6192 /* sqrt(x) > y is always false, when y is very large
6193 and we don't care about infinities. */
6194 return omit_one_operand (type, integer_zero_node, arg);
6197 /* sqrt(x) > c is the same as x > c*c. */
6198 return fold_build2 (code, type, arg,
6199 build_real (TREE_TYPE (arg), c2));
6201 else if (code == LT_EXPR || code == LE_EXPR)
6205 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
6206 real_convert (&c2, mode, &c2);
6208 if (REAL_VALUE_ISINF (c2))
6210 /* sqrt(x) < y is always true, when y is a very large
6211 value and we don't care about NaNs or Infinities. */
6212 if (! HONOR_NANS (mode) && ! HONOR_INFINITIES (mode))
6213 return omit_one_operand (type, integer_one_node, arg);
6215 /* sqrt(x) < y is x != +Inf when y is very large and we
6216 don't care about NaNs. */
6217 if (! HONOR_NANS (mode))
6218 return fold_build2 (NE_EXPR, type, arg,
6219 build_real (TREE_TYPE (arg), c2));
6221 /* sqrt(x) < y is x >= 0 when y is very large and we
6222 don't care about Infinities. */
6223 if (! HONOR_INFINITIES (mode))
6224 return fold_build2 (GE_EXPR, type, arg,
6225 build_real (TREE_TYPE (arg), dconst0));
6227 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
6228 if (lang_hooks.decls.global_bindings_p () != 0
6229 || CONTAINS_PLACEHOLDER_P (arg))
6232 arg = save_expr (arg);
6233 return fold_build2 (TRUTH_ANDIF_EXPR, type,
6234 fold_build2 (GE_EXPR, type, arg,
6235 build_real (TREE_TYPE (arg),
6237 fold_build2 (NE_EXPR, type, arg,
6238 build_real (TREE_TYPE (arg),
6242 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
6243 if (! HONOR_NANS (mode))
6244 return fold_build2 (code, type, arg,
6245 build_real (TREE_TYPE (arg), c2));
6247 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
6248 if (lang_hooks.decls.global_bindings_p () == 0
6249 && ! CONTAINS_PLACEHOLDER_P (arg))
6251 arg = save_expr (arg);
6252 return fold_build2 (TRUTH_ANDIF_EXPR, type,
6253 fold_build2 (GE_EXPR, type, arg,
6254 build_real (TREE_TYPE (arg),
6256 fold_build2 (code, type, arg,
6257 build_real (TREE_TYPE (arg),
6266 /* Subroutine of fold() that optimizes comparisons against Infinities,
6267 either +Inf or -Inf.
6269 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
6270 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
6271 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
6273 The function returns the constant folded tree if a simplification
6274 can be made, and NULL_TREE otherwise. */
6277 fold_inf_compare (enum tree_code code, tree type, tree arg0, tree arg1)
6279 enum machine_mode mode;
6280 REAL_VALUE_TYPE max;
6284 mode = TYPE_MODE (TREE_TYPE (arg0));
6286 /* For negative infinity swap the sense of the comparison. */
6287 neg = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1));
6289 code = swap_tree_comparison (code);
6294 /* x > +Inf is always false, if with ignore sNANs. */
6295 if (HONOR_SNANS (mode))
6297 return omit_one_operand (type, integer_zero_node, arg0);
6300 /* x <= +Inf is always true, if we don't case about NaNs. */
6301 if (! HONOR_NANS (mode))
6302 return omit_one_operand (type, integer_one_node, arg0);
6304 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
6305 if (lang_hooks.decls.global_bindings_p () == 0
6306 && ! CONTAINS_PLACEHOLDER_P (arg0))
6308 arg0 = save_expr (arg0);
6309 return fold_build2 (EQ_EXPR, type, arg0, arg0);
6315 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
6316 real_maxval (&max, neg, mode);
6317 return fold_build2 (neg ? LT_EXPR : GT_EXPR, type,
6318 arg0, build_real (TREE_TYPE (arg0), max));
6321 /* x < +Inf is always equal to x <= DBL_MAX. */
6322 real_maxval (&max, neg, mode);
6323 return fold_build2 (neg ? GE_EXPR : LE_EXPR, type,
6324 arg0, build_real (TREE_TYPE (arg0), max));
6327 /* x != +Inf is always equal to !(x > DBL_MAX). */
6328 real_maxval (&max, neg, mode);
6329 if (! HONOR_NANS (mode))
6330 return fold_build2 (neg ? GE_EXPR : LE_EXPR, type,
6331 arg0, build_real (TREE_TYPE (arg0), max));
6333 temp = fold_build2 (neg ? LT_EXPR : GT_EXPR, type,
6334 arg0, build_real (TREE_TYPE (arg0), max));
6335 return fold_build1 (TRUTH_NOT_EXPR, type, temp);
6344 /* Subroutine of fold() that optimizes comparisons of a division by
6345 a nonzero integer constant against an integer constant, i.e.
6348 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
6349 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
6350 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
6352 The function returns the constant folded tree if a simplification
6353 can be made, and NULL_TREE otherwise. */
6356 fold_div_compare (enum tree_code code, tree type, tree arg0, tree arg1)
6358 tree prod, tmp, hi, lo;
6359 tree arg00 = TREE_OPERAND (arg0, 0);
6360 tree arg01 = TREE_OPERAND (arg0, 1);
6361 unsigned HOST_WIDE_INT lpart;
6362 HOST_WIDE_INT hpart;
6363 bool unsigned_p = TYPE_UNSIGNED (TREE_TYPE (arg0));
6367 /* We have to do this the hard way to detect unsigned overflow.
6368 prod = int_const_binop (MULT_EXPR, arg01, arg1, 0); */
6369 overflow = mul_double_with_sign (TREE_INT_CST_LOW (arg01),
6370 TREE_INT_CST_HIGH (arg01),
6371 TREE_INT_CST_LOW (arg1),
6372 TREE_INT_CST_HIGH (arg1),
6373 &lpart, &hpart, unsigned_p);
6374 prod = force_fit_type_double (TREE_TYPE (arg00), lpart, hpart,
6376 neg_overflow = false;
6380 tmp = int_const_binop (MINUS_EXPR, arg01,
6381 build_int_cst (TREE_TYPE (arg01), 1), 0);
6384 /* Likewise hi = int_const_binop (PLUS_EXPR, prod, tmp, 0). */
6385 overflow = add_double_with_sign (TREE_INT_CST_LOW (prod),
6386 TREE_INT_CST_HIGH (prod),
6387 TREE_INT_CST_LOW (tmp),
6388 TREE_INT_CST_HIGH (tmp),
6389 &lpart, &hpart, unsigned_p);
6390 hi = force_fit_type_double (TREE_TYPE (arg00), lpart, hpart,
6391 -1, overflow | TREE_OVERFLOW (prod));
6393 else if (tree_int_cst_sgn (arg01) >= 0)
6395 tmp = int_const_binop (MINUS_EXPR, arg01,
6396 build_int_cst (TREE_TYPE (arg01), 1), 0);
6397 switch (tree_int_cst_sgn (arg1))
6400 neg_overflow = true;
6401 lo = int_const_binop (MINUS_EXPR, prod, tmp, 0);
6406 lo = fold_negate_const (tmp, TREE_TYPE (arg0));
6411 hi = int_const_binop (PLUS_EXPR, prod, tmp, 0);
6421 /* A negative divisor reverses the relational operators. */
6422 code = swap_tree_comparison (code);
6424 tmp = int_const_binop (PLUS_EXPR, arg01,
6425 build_int_cst (TREE_TYPE (arg01), 1), 0);
6426 switch (tree_int_cst_sgn (arg1))
6429 hi = int_const_binop (MINUS_EXPR, prod, tmp, 0);
6434 hi = fold_negate_const (tmp, TREE_TYPE (arg0));
6439 neg_overflow = true;
6440 lo = int_const_binop (PLUS_EXPR, prod, tmp, 0);
6452 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
6453 return omit_one_operand (type, integer_zero_node, arg00);
6454 if (TREE_OVERFLOW (hi))
6455 return fold_build2 (GE_EXPR, type, arg00, lo);
6456 if (TREE_OVERFLOW (lo))
6457 return fold_build2 (LE_EXPR, type, arg00, hi);
6458 return build_range_check (type, arg00, 1, lo, hi);
6461 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
6462 return omit_one_operand (type, integer_one_node, arg00);
6463 if (TREE_OVERFLOW (hi))
6464 return fold_build2 (LT_EXPR, type, arg00, lo);
6465 if (TREE_OVERFLOW (lo))
6466 return fold_build2 (GT_EXPR, type, arg00, hi);
6467 return build_range_check (type, arg00, 0, lo, hi);
6470 if (TREE_OVERFLOW (lo))
6472 tmp = neg_overflow ? integer_zero_node : integer_one_node;
6473 return omit_one_operand (type, tmp, arg00);
6475 return fold_build2 (LT_EXPR, type, arg00, lo);
6478 if (TREE_OVERFLOW (hi))
6480 tmp = neg_overflow ? integer_zero_node : integer_one_node;
6481 return omit_one_operand (type, tmp, arg00);
6483 return fold_build2 (LE_EXPR, type, arg00, hi);
6486 if (TREE_OVERFLOW (hi))
6488 tmp = neg_overflow ? integer_one_node : integer_zero_node;
6489 return omit_one_operand (type, tmp, arg00);
6491 return fold_build2 (GT_EXPR, type, arg00, hi);
6494 if (TREE_OVERFLOW (lo))
6496 tmp = neg_overflow ? integer_one_node : integer_zero_node;
6497 return omit_one_operand (type, tmp, arg00);
6499 return fold_build2 (GE_EXPR, type, arg00, lo);
6509 /* If CODE with arguments ARG0 and ARG1 represents a single bit
6510 equality/inequality test, then return a simplified form of the test
6511 using a sign testing. Otherwise return NULL. TYPE is the desired
6515 fold_single_bit_test_into_sign_test (enum tree_code code, tree arg0, tree arg1,
6518 /* If this is testing a single bit, we can optimize the test. */
6519 if ((code == NE_EXPR || code == EQ_EXPR)
6520 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
6521 && integer_pow2p (TREE_OPERAND (arg0, 1)))
6523 /* If we have (A & C) != 0 where C is the sign bit of A, convert
6524 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
6525 tree arg00 = sign_bit_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
6527 if (arg00 != NULL_TREE
6528 /* This is only a win if casting to a signed type is cheap,
6529 i.e. when arg00's type is not a partial mode. */
6530 && TYPE_PRECISION (TREE_TYPE (arg00))
6531 == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg00))))
6533 tree stype = lang_hooks.types.signed_type (TREE_TYPE (arg00));
6534 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
6535 result_type, fold_convert (stype, arg00),
6536 build_int_cst (stype, 0));
6543 /* If CODE with arguments ARG0 and ARG1 represents a single bit
6544 equality/inequality test, then return a simplified form of
6545 the test using shifts and logical operations. Otherwise return
6546 NULL. TYPE is the desired result type. */
6549 fold_single_bit_test (enum tree_code code, tree arg0, tree arg1,
6552 /* If this is testing a single bit, we can optimize the test. */
6553 if ((code == NE_EXPR || code == EQ_EXPR)
6554 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
6555 && integer_pow2p (TREE_OPERAND (arg0, 1)))
6557 tree inner = TREE_OPERAND (arg0, 0);
6558 tree type = TREE_TYPE (arg0);
6559 int bitnum = tree_log2 (TREE_OPERAND (arg0, 1));
6560 enum machine_mode operand_mode = TYPE_MODE (type);
6562 tree signed_type, unsigned_type, intermediate_type;
6565 /* First, see if we can fold the single bit test into a sign-bit
6567 tem = fold_single_bit_test_into_sign_test (code, arg0, arg1,
6572 /* Otherwise we have (A & C) != 0 where C is a single bit,
6573 convert that into ((A >> C2) & 1). Where C2 = log2(C).
6574 Similarly for (A & C) == 0. */
6576 /* If INNER is a right shift of a constant and it plus BITNUM does
6577 not overflow, adjust BITNUM and INNER. */
6578 if (TREE_CODE (inner) == RSHIFT_EXPR
6579 && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST
6580 && TREE_INT_CST_HIGH (TREE_OPERAND (inner, 1)) == 0
6581 && bitnum < TYPE_PRECISION (type)
6582 && 0 > compare_tree_int (TREE_OPERAND (inner, 1),
6583 bitnum - TYPE_PRECISION (type)))
6585 bitnum += TREE_INT_CST_LOW (TREE_OPERAND (inner, 1));
6586 inner = TREE_OPERAND (inner, 0);
6589 /* If we are going to be able to omit the AND below, we must do our
6590 operations as unsigned. If we must use the AND, we have a choice.
6591 Normally unsigned is faster, but for some machines signed is. */
6592 #ifdef LOAD_EXTEND_OP
6593 ops_unsigned = (LOAD_EXTEND_OP (operand_mode) == SIGN_EXTEND
6594 && !flag_syntax_only) ? 0 : 1;
6599 signed_type = lang_hooks.types.type_for_mode (operand_mode, 0);
6600 unsigned_type = lang_hooks.types.type_for_mode (operand_mode, 1);
6601 intermediate_type = ops_unsigned ? unsigned_type : signed_type;
6602 inner = fold_convert (intermediate_type, inner);
6605 inner = build2 (RSHIFT_EXPR, intermediate_type,
6606 inner, size_int (bitnum));
6608 one = build_int_cst (intermediate_type, 1);
6610 if (code == EQ_EXPR)
6611 inner = fold_build2 (BIT_XOR_EXPR, intermediate_type, inner, one);
6613 /* Put the AND last so it can combine with more things. */
6614 inner = build2 (BIT_AND_EXPR, intermediate_type, inner, one);
6616 /* Make sure to return the proper type. */
6617 inner = fold_convert (result_type, inner);
6624 /* Check whether we are allowed to reorder operands arg0 and arg1,
6625 such that the evaluation of arg1 occurs before arg0. */
6628 reorder_operands_p (tree arg0, tree arg1)
6630 if (! flag_evaluation_order)
6632 if (TREE_CONSTANT (arg0) || TREE_CONSTANT (arg1))
6634 return ! TREE_SIDE_EFFECTS (arg0)
6635 && ! TREE_SIDE_EFFECTS (arg1);
6638 /* Test whether it is preferable two swap two operands, ARG0 and
6639 ARG1, for example because ARG0 is an integer constant and ARG1
6640 isn't. If REORDER is true, only recommend swapping if we can
6641 evaluate the operands in reverse order. */
6644 tree_swap_operands_p (tree arg0, tree arg1, bool reorder)
6646 STRIP_SIGN_NOPS (arg0);
6647 STRIP_SIGN_NOPS (arg1);
6649 if (TREE_CODE (arg1) == INTEGER_CST)
6651 if (TREE_CODE (arg0) == INTEGER_CST)
6654 if (TREE_CODE (arg1) == REAL_CST)
6656 if (TREE_CODE (arg0) == REAL_CST)
6659 if (TREE_CODE (arg1) == COMPLEX_CST)
6661 if (TREE_CODE (arg0) == COMPLEX_CST)
6664 if (TREE_CONSTANT (arg1))
6666 if (TREE_CONSTANT (arg0))
6672 if (reorder && flag_evaluation_order
6673 && (TREE_SIDE_EFFECTS (arg0) || TREE_SIDE_EFFECTS (arg1)))
6676 /* It is preferable to swap two SSA_NAME to ensure a canonical form
6677 for commutative and comparison operators. Ensuring a canonical
6678 form allows the optimizers to find additional redundancies without
6679 having to explicitly check for both orderings. */
6680 if (TREE_CODE (arg0) == SSA_NAME
6681 && TREE_CODE (arg1) == SSA_NAME
6682 && SSA_NAME_VERSION (arg0) > SSA_NAME_VERSION (arg1))
6685 /* Put SSA_NAMEs last. */
6686 if (TREE_CODE (arg1) == SSA_NAME)
6688 if (TREE_CODE (arg0) == SSA_NAME)
6691 /* Put variables last. */
6700 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where
6701 ARG0 is extended to a wider type. */
6704 fold_widened_comparison (enum tree_code code, tree type, tree arg0, tree arg1)
6706 tree arg0_unw = get_unwidened (arg0, NULL_TREE);
6708 tree shorter_type, outer_type;
6712 if (arg0_unw == arg0)
6714 shorter_type = TREE_TYPE (arg0_unw);
6716 #ifdef HAVE_canonicalize_funcptr_for_compare
6717 /* Disable this optimization if we're casting a function pointer
6718 type on targets that require function pointer canonicalization. */
6719 if (HAVE_canonicalize_funcptr_for_compare
6720 && TREE_CODE (shorter_type) == POINTER_TYPE
6721 && TREE_CODE (TREE_TYPE (shorter_type)) == FUNCTION_TYPE)
6725 if (TYPE_PRECISION (TREE_TYPE (arg0)) <= TYPE_PRECISION (shorter_type))
6728 arg1_unw = get_unwidened (arg1, shorter_type);
6730 /* If possible, express the comparison in the shorter mode. */
6731 if ((code == EQ_EXPR || code == NE_EXPR
6732 || TYPE_UNSIGNED (TREE_TYPE (arg0)) == TYPE_UNSIGNED (shorter_type))
6733 && (TREE_TYPE (arg1_unw) == shorter_type
6734 || (TREE_CODE (arg1_unw) == INTEGER_CST
6735 && (TREE_CODE (shorter_type) == INTEGER_TYPE
6736 || TREE_CODE (shorter_type) == BOOLEAN_TYPE)
6737 && int_fits_type_p (arg1_unw, shorter_type))))
6738 return fold_build2 (code, type, arg0_unw,
6739 fold_convert (shorter_type, arg1_unw));
6741 if (TREE_CODE (arg1_unw) != INTEGER_CST
6742 || TREE_CODE (shorter_type) != INTEGER_TYPE
6743 || !int_fits_type_p (arg1_unw, shorter_type))
6746 /* If we are comparing with the integer that does not fit into the range
6747 of the shorter type, the result is known. */
6748 outer_type = TREE_TYPE (arg1_unw);
6749 min = lower_bound_in_type (outer_type, shorter_type);
6750 max = upper_bound_in_type (outer_type, shorter_type);
6752 above = integer_nonzerop (fold_relational_const (LT_EXPR, type,
6754 below = integer_nonzerop (fold_relational_const (LT_EXPR, type,
6761 return omit_one_operand (type, integer_zero_node, arg0);
6766 return omit_one_operand (type, integer_one_node, arg0);
6772 return omit_one_operand (type, integer_one_node, arg0);
6774 return omit_one_operand (type, integer_zero_node, arg0);
6779 return omit_one_operand (type, integer_zero_node, arg0);
6781 return omit_one_operand (type, integer_one_node, arg0);
6790 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where for
6791 ARG0 just the signedness is changed. */
6794 fold_sign_changed_comparison (enum tree_code code, tree type,
6795 tree arg0, tree arg1)
6798 tree inner_type, outer_type;
6800 if (TREE_CODE (arg0) != NOP_EXPR
6801 && TREE_CODE (arg0) != CONVERT_EXPR)
6804 outer_type = TREE_TYPE (arg0);
6805 arg0_inner = TREE_OPERAND (arg0, 0);
6806 inner_type = TREE_TYPE (arg0_inner);
6808 #ifdef HAVE_canonicalize_funcptr_for_compare
6809 /* Disable this optimization if we're casting a function pointer
6810 type on targets that require function pointer canonicalization. */
6811 if (HAVE_canonicalize_funcptr_for_compare
6812 && TREE_CODE (inner_type) == POINTER_TYPE
6813 && TREE_CODE (TREE_TYPE (inner_type)) == FUNCTION_TYPE)
6817 if (TYPE_PRECISION (inner_type) != TYPE_PRECISION (outer_type))
6820 if (TREE_CODE (arg1) != INTEGER_CST
6821 && !((TREE_CODE (arg1) == NOP_EXPR
6822 || TREE_CODE (arg1) == CONVERT_EXPR)
6823 && TREE_TYPE (TREE_OPERAND (arg1, 0)) == inner_type))
6826 if (TYPE_UNSIGNED (inner_type) != TYPE_UNSIGNED (outer_type)
6831 if (TREE_CODE (arg1) == INTEGER_CST)
6832 arg1 = force_fit_type_double (inner_type, TREE_INT_CST_LOW (arg1),
6833 TREE_INT_CST_HIGH (arg1), 0,
6834 TREE_OVERFLOW (arg1));
6836 arg1 = fold_convert (inner_type, arg1);
6838 return fold_build2 (code, type, arg0_inner, arg1);
6841 /* Tries to replace &a[idx] CODE s * delta with &a[idx CODE delta], if s is
6842 step of the array. Reconstructs s and delta in the case of s * delta
6843 being an integer constant (and thus already folded).
6844 ADDR is the address. MULT is the multiplicative expression.
6845 If the function succeeds, the new address expression is returned. Otherwise
6846 NULL_TREE is returned. */
6849 try_move_mult_to_index (enum tree_code code, tree addr, tree op1)
6851 tree s, delta, step;
6852 tree ref = TREE_OPERAND (addr, 0), pref;
6857 /* Canonicalize op1 into a possibly non-constant delta
6858 and an INTEGER_CST s. */
6859 if (TREE_CODE (op1) == MULT_EXPR)
6861 tree arg0 = TREE_OPERAND (op1, 0), arg1 = TREE_OPERAND (op1, 1);
6866 if (TREE_CODE (arg0) == INTEGER_CST)
6871 else if (TREE_CODE (arg1) == INTEGER_CST)
6879 else if (TREE_CODE (op1) == INTEGER_CST)
6886 /* Simulate we are delta * 1. */
6888 s = integer_one_node;
6891 for (;; ref = TREE_OPERAND (ref, 0))
6893 if (TREE_CODE (ref) == ARRAY_REF)
6895 /* Remember if this was a multi-dimensional array. */
6896 if (TREE_CODE (TREE_OPERAND (ref, 0)) == ARRAY_REF)
6899 itype = TYPE_DOMAIN (TREE_TYPE (TREE_OPERAND (ref, 0)));
6903 step = array_ref_element_size (ref);
6904 if (TREE_CODE (step) != INTEGER_CST)
6909 if (! tree_int_cst_equal (step, s))
6914 /* Try if delta is a multiple of step. */
6915 tree tmp = div_if_zero_remainder (EXACT_DIV_EXPR, delta, step);
6921 /* Only fold here if we can verify we do not overflow one
6922 dimension of a multi-dimensional array. */
6927 if (TREE_CODE (TREE_OPERAND (ref, 1)) != INTEGER_CST
6928 || !INTEGRAL_TYPE_P (itype)
6929 || !TYPE_MAX_VALUE (itype)
6930 || TREE_CODE (TYPE_MAX_VALUE (itype)) != INTEGER_CST)
6933 tmp = fold_binary (code, itype,
6934 fold_convert (itype,
6935 TREE_OPERAND (ref, 1)),
6936 fold_convert (itype, delta));
6938 || TREE_CODE (tmp) != INTEGER_CST
6939 || tree_int_cst_lt (TYPE_MAX_VALUE (itype), tmp))
6948 if (!handled_component_p (ref))
6952 /* We found the suitable array reference. So copy everything up to it,
6953 and replace the index. */
6955 pref = TREE_OPERAND (addr, 0);
6956 ret = copy_node (pref);
6961 pref = TREE_OPERAND (pref, 0);
6962 TREE_OPERAND (pos, 0) = copy_node (pref);
6963 pos = TREE_OPERAND (pos, 0);
6966 TREE_OPERAND (pos, 1) = fold_build2 (code, itype,
6967 fold_convert (itype,
6968 TREE_OPERAND (pos, 1)),
6969 fold_convert (itype, delta));
6971 return fold_build1 (ADDR_EXPR, TREE_TYPE (addr), ret);
6975 /* Fold A < X && A + 1 > Y to A < X && A >= Y. Normally A + 1 > Y
6976 means A >= Y && A != MAX, but in this case we know that
6977 A < X <= MAX. INEQ is A + 1 > Y, BOUND is A < X. */
6980 fold_to_nonsharp_ineq_using_bound (tree ineq, tree bound)
6982 tree a, typea, type = TREE_TYPE (ineq), a1, diff, y;
6984 if (TREE_CODE (bound) == LT_EXPR)
6985 a = TREE_OPERAND (bound, 0);
6986 else if (TREE_CODE (bound) == GT_EXPR)
6987 a = TREE_OPERAND (bound, 1);
6991 typea = TREE_TYPE (a);
6992 if (!INTEGRAL_TYPE_P (typea)
6993 && !POINTER_TYPE_P (typea))
6996 if (TREE_CODE (ineq) == LT_EXPR)
6998 a1 = TREE_OPERAND (ineq, 1);
6999 y = TREE_OPERAND (ineq, 0);
7001 else if (TREE_CODE (ineq) == GT_EXPR)
7003 a1 = TREE_OPERAND (ineq, 0);
7004 y = TREE_OPERAND (ineq, 1);
7009 if (TREE_TYPE (a1) != typea)
7012 diff = fold_build2 (MINUS_EXPR, typea, a1, a);
7013 if (!integer_onep (diff))
7016 return fold_build2 (GE_EXPR, type, a, y);
7019 /* Fold a sum or difference of at least one multiplication.
7020 Returns the folded tree or NULL if no simplification could be made. */
7023 fold_plusminus_mult_expr (enum tree_code code, tree type, tree arg0, tree arg1)
7025 tree arg00, arg01, arg10, arg11;
7026 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
7028 /* (A * C) +- (B * C) -> (A+-B) * C.
7029 (A * C) +- A -> A * (C+-1).
7030 We are most concerned about the case where C is a constant,
7031 but other combinations show up during loop reduction. Since
7032 it is not difficult, try all four possibilities. */
7034 if (TREE_CODE (arg0) == MULT_EXPR)
7036 arg00 = TREE_OPERAND (arg0, 0);
7037 arg01 = TREE_OPERAND (arg0, 1);
7042 arg01 = build_one_cst (type);
7044 if (TREE_CODE (arg1) == MULT_EXPR)
7046 arg10 = TREE_OPERAND (arg1, 0);
7047 arg11 = TREE_OPERAND (arg1, 1);
7052 arg11 = build_one_cst (type);
7056 if (operand_equal_p (arg01, arg11, 0))
7057 same = arg01, alt0 = arg00, alt1 = arg10;
7058 else if (operand_equal_p (arg00, arg10, 0))
7059 same = arg00, alt0 = arg01, alt1 = arg11;
7060 else if (operand_equal_p (arg00, arg11, 0))
7061 same = arg00, alt0 = arg01, alt1 = arg10;
7062 else if (operand_equal_p (arg01, arg10, 0))
7063 same = arg01, alt0 = arg00, alt1 = arg11;
7065 /* No identical multiplicands; see if we can find a common
7066 power-of-two factor in non-power-of-two multiplies. This
7067 can help in multi-dimensional array access. */
7068 else if (host_integerp (arg01, 0)
7069 && host_integerp (arg11, 0))
7071 HOST_WIDE_INT int01, int11, tmp;
7074 int01 = TREE_INT_CST_LOW (arg01);
7075 int11 = TREE_INT_CST_LOW (arg11);
7077 /* Move min of absolute values to int11. */
7078 if ((int01 >= 0 ? int01 : -int01)
7079 < (int11 >= 0 ? int11 : -int11))
7081 tmp = int01, int01 = int11, int11 = tmp;
7082 alt0 = arg00, arg00 = arg10, arg10 = alt0;
7089 if (exact_log2 (abs (int11)) > 0 && int01 % int11 == 0)
7091 alt0 = fold_build2 (MULT_EXPR, TREE_TYPE (arg00), arg00,
7092 build_int_cst (TREE_TYPE (arg00),
7097 maybe_same = alt0, alt0 = alt1, alt1 = maybe_same;
7102 return fold_build2 (MULT_EXPR, type,
7103 fold_build2 (code, type,
7104 fold_convert (type, alt0),
7105 fold_convert (type, alt1)),
7106 fold_convert (type, same));
7111 /* Subroutine of native_encode_expr. Encode the INTEGER_CST
7112 specified by EXPR into the buffer PTR of length LEN bytes.
7113 Return the number of bytes placed in the buffer, or zero
7117 native_encode_int (tree expr, unsigned char *ptr, int len)
7119 tree type = TREE_TYPE (expr);
7120 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7121 int byte, offset, word, words;
7122 unsigned char value;
7124 if (total_bytes > len)
7126 words = total_bytes / UNITS_PER_WORD;
7128 for (byte = 0; byte < total_bytes; byte++)
7130 int bitpos = byte * BITS_PER_UNIT;
7131 if (bitpos < HOST_BITS_PER_WIDE_INT)
7132 value = (unsigned char) (TREE_INT_CST_LOW (expr) >> bitpos);
7134 value = (unsigned char) (TREE_INT_CST_HIGH (expr)
7135 >> (bitpos - HOST_BITS_PER_WIDE_INT));
7137 if (total_bytes > UNITS_PER_WORD)
7139 word = byte / UNITS_PER_WORD;
7140 if (WORDS_BIG_ENDIAN)
7141 word = (words - 1) - word;
7142 offset = word * UNITS_PER_WORD;
7143 if (BYTES_BIG_ENDIAN)
7144 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7146 offset += byte % UNITS_PER_WORD;
7149 offset = BYTES_BIG_ENDIAN ? (total_bytes - 1) - byte : byte;
7150 ptr[offset] = value;
7156 /* Subroutine of native_encode_expr. Encode the REAL_CST
7157 specified by EXPR into the buffer PTR of length LEN bytes.
7158 Return the number of bytes placed in the buffer, or zero
7162 native_encode_real (tree expr, unsigned char *ptr, int len)
7164 tree type = TREE_TYPE (expr);
7165 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7166 int byte, offset, word, words;
7167 unsigned char value;
7169 /* There are always 32 bits in each long, no matter the size of
7170 the hosts long. We handle floating point representations with
7174 if (total_bytes > len)
7176 words = total_bytes / UNITS_PER_WORD;
7178 real_to_target (tmp, TREE_REAL_CST_PTR (expr), TYPE_MODE (type));
7180 for (byte = 0; byte < total_bytes; byte++)
7182 int bitpos = byte * BITS_PER_UNIT;
7183 value = (unsigned char) (tmp[bitpos / 32] >> (bitpos & 31));
7185 if (total_bytes > UNITS_PER_WORD)
7187 word = byte / UNITS_PER_WORD;
7188 if (FLOAT_WORDS_BIG_ENDIAN)
7189 word = (words - 1) - word;
7190 offset = word * UNITS_PER_WORD;
7191 if (BYTES_BIG_ENDIAN)
7192 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7194 offset += byte % UNITS_PER_WORD;
7197 offset = BYTES_BIG_ENDIAN ? (total_bytes - 1) - byte : byte;
7198 ptr[offset] = value;
7203 /* Subroutine of native_encode_expr. Encode the COMPLEX_CST
7204 specified by EXPR into the buffer PTR of length LEN bytes.
7205 Return the number of bytes placed in the buffer, or zero
7209 native_encode_complex (tree expr, unsigned char *ptr, int len)
7214 part = TREE_REALPART (expr);
7215 rsize = native_encode_expr (part, ptr, len);
7218 part = TREE_IMAGPART (expr);
7219 isize = native_encode_expr (part, ptr+rsize, len-rsize);
7222 return rsize + isize;
7226 /* Subroutine of native_encode_expr. Encode the VECTOR_CST
7227 specified by EXPR into the buffer PTR of length LEN bytes.
7228 Return the number of bytes placed in the buffer, or zero
7232 native_encode_vector (tree expr, unsigned char *ptr, int len)
7234 int i, size, offset, count;
7235 tree itype, elem, elements;
7238 elements = TREE_VECTOR_CST_ELTS (expr);
7239 count = TYPE_VECTOR_SUBPARTS (TREE_TYPE (expr));
7240 itype = TREE_TYPE (TREE_TYPE (expr));
7241 size = GET_MODE_SIZE (TYPE_MODE (itype));
7242 for (i = 0; i < count; i++)
7246 elem = TREE_VALUE (elements);
7247 elements = TREE_CHAIN (elements);
7254 if (native_encode_expr (elem, ptr+offset, len-offset) != size)
7259 if (offset + size > len)
7261 memset (ptr+offset, 0, size);
7269 /* Subroutine of fold_view_convert_expr. Encode the INTEGER_CST,
7270 REAL_CST, COMPLEX_CST or VECTOR_CST specified by EXPR into the
7271 buffer PTR of length LEN bytes. Return the number of bytes
7272 placed in the buffer, or zero upon failure. */
7275 native_encode_expr (tree expr, unsigned char *ptr, int len)
7277 switch (TREE_CODE (expr))
7280 return native_encode_int (expr, ptr, len);
7283 return native_encode_real (expr, ptr, len);
7286 return native_encode_complex (expr, ptr, len);
7289 return native_encode_vector (expr, ptr, len);
7297 /* Subroutine of native_interpret_expr. Interpret the contents of
7298 the buffer PTR of length LEN as an INTEGER_CST of type TYPE.
7299 If the buffer cannot be interpreted, return NULL_TREE. */
7302 native_interpret_int (tree type, unsigned char *ptr, int len)
7304 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7305 int byte, offset, word, words;
7306 unsigned char value;
7307 unsigned int HOST_WIDE_INT lo = 0;
7308 HOST_WIDE_INT hi = 0;
7310 if (total_bytes > len)
7312 if (total_bytes * BITS_PER_UNIT > 2 * HOST_BITS_PER_WIDE_INT)
7314 words = total_bytes / UNITS_PER_WORD;
7316 for (byte = 0; byte < total_bytes; byte++)
7318 int bitpos = byte * BITS_PER_UNIT;
7319 if (total_bytes > UNITS_PER_WORD)
7321 word = byte / UNITS_PER_WORD;
7322 if (WORDS_BIG_ENDIAN)
7323 word = (words - 1) - word;
7324 offset = word * UNITS_PER_WORD;
7325 if (BYTES_BIG_ENDIAN)
7326 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7328 offset += byte % UNITS_PER_WORD;
7331 offset = BYTES_BIG_ENDIAN ? (total_bytes - 1) - byte : byte;
7332 value = ptr[offset];
7334 if (bitpos < HOST_BITS_PER_WIDE_INT)
7335 lo |= (unsigned HOST_WIDE_INT) value << bitpos;
7337 hi |= (unsigned HOST_WIDE_INT) value
7338 << (bitpos - HOST_BITS_PER_WIDE_INT);
7341 return build_int_cst_wide_type (type, lo, hi);
7345 /* Subroutine of native_interpret_expr. Interpret the contents of
7346 the buffer PTR of length LEN as a REAL_CST of type TYPE.
7347 If the buffer cannot be interpreted, return NULL_TREE. */
7350 native_interpret_real (tree type, unsigned char *ptr, int len)
7352 enum machine_mode mode = TYPE_MODE (type);
7353 int total_bytes = GET_MODE_SIZE (mode);
7354 int byte, offset, word, words;
7355 unsigned char value;
7356 /* There are always 32 bits in each long, no matter the size of
7357 the hosts long. We handle floating point representations with
7362 total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7363 if (total_bytes > len || total_bytes > 24)
7365 words = total_bytes / UNITS_PER_WORD;
7367 memset (tmp, 0, sizeof (tmp));
7368 for (byte = 0; byte < total_bytes; byte++)
7370 int bitpos = byte * BITS_PER_UNIT;
7371 if (total_bytes > UNITS_PER_WORD)
7373 word = byte / UNITS_PER_WORD;
7374 if (FLOAT_WORDS_BIG_ENDIAN)
7375 word = (words - 1) - word;
7376 offset = word * UNITS_PER_WORD;
7377 if (BYTES_BIG_ENDIAN)
7378 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7380 offset += byte % UNITS_PER_WORD;
7383 offset = BYTES_BIG_ENDIAN ? (total_bytes - 1) - byte : byte;
7384 value = ptr[offset];
7386 tmp[bitpos / 32] |= (unsigned long)value << (bitpos & 31);
7389 real_from_target (&r, tmp, mode);
7390 return build_real (type, r);
7394 /* Subroutine of native_interpret_expr. Interpret the contents of
7395 the buffer PTR of length LEN as a COMPLEX_CST of type TYPE.
7396 If the buffer cannot be interpreted, return NULL_TREE. */
7399 native_interpret_complex (tree type, unsigned char *ptr, int len)
7401 tree etype, rpart, ipart;
7404 etype = TREE_TYPE (type);
7405 size = GET_MODE_SIZE (TYPE_MODE (etype));
7408 rpart = native_interpret_expr (etype, ptr, size);
7411 ipart = native_interpret_expr (etype, ptr+size, size);
7414 return build_complex (type, rpart, ipart);
7418 /* Subroutine of native_interpret_expr. Interpret the contents of
7419 the buffer PTR of length LEN as a VECTOR_CST of type TYPE.
7420 If the buffer cannot be interpreted, return NULL_TREE. */
7423 native_interpret_vector (tree type, unsigned char *ptr, int len)
7425 tree etype, elem, elements;
7428 etype = TREE_TYPE (type);
7429 size = GET_MODE_SIZE (TYPE_MODE (etype));
7430 count = TYPE_VECTOR_SUBPARTS (type);
7431 if (size * count > len)
7434 elements = NULL_TREE;
7435 for (i = count - 1; i >= 0; i--)
7437 elem = native_interpret_expr (etype, ptr+(i*size), size);
7440 elements = tree_cons (NULL_TREE, elem, elements);
7442 return build_vector (type, elements);
7446 /* Subroutine of fold_view_convert_expr. Interpret the contents of
7447 the buffer PTR of length LEN as a constant of type TYPE. For
7448 INTEGRAL_TYPE_P we return an INTEGER_CST, for SCALAR_FLOAT_TYPE_P
7449 we return a REAL_CST, etc... If the buffer cannot be interpreted,
7450 return NULL_TREE. */
7453 native_interpret_expr (tree type, unsigned char *ptr, int len)
7455 switch (TREE_CODE (type))
7460 return native_interpret_int (type, ptr, len);
7463 return native_interpret_real (type, ptr, len);
7466 return native_interpret_complex (type, ptr, len);
7469 return native_interpret_vector (type, ptr, len);
7477 /* Fold a VIEW_CONVERT_EXPR of a constant expression EXPR to type
7478 TYPE at compile-time. If we're unable to perform the conversion
7479 return NULL_TREE. */
7482 fold_view_convert_expr (tree type, tree expr)
7484 /* We support up to 512-bit values (for V8DFmode). */
7485 unsigned char buffer[64];
7488 /* Check that the host and target are sane. */
7489 if (CHAR_BIT != 8 || BITS_PER_UNIT != 8)
7492 len = native_encode_expr (expr, buffer, sizeof (buffer));
7496 return native_interpret_expr (type, buffer, len);
7500 /* Fold a unary expression of code CODE and type TYPE with operand
7501 OP0. Return the folded expression if folding is successful.
7502 Otherwise, return NULL_TREE. */
7505 fold_unary (enum tree_code code, tree type, tree op0)
7509 enum tree_code_class kind = TREE_CODE_CLASS (code);
7511 gcc_assert (IS_EXPR_CODE_CLASS (kind)
7512 && TREE_CODE_LENGTH (code) == 1);
7517 if (code == NOP_EXPR || code == CONVERT_EXPR
7518 || code == FLOAT_EXPR || code == ABS_EXPR)
7520 /* Don't use STRIP_NOPS, because signedness of argument type
7522 STRIP_SIGN_NOPS (arg0);
7526 /* Strip any conversions that don't change the mode. This
7527 is safe for every expression, except for a comparison
7528 expression because its signedness is derived from its
7531 Note that this is done as an internal manipulation within
7532 the constant folder, in order to find the simplest
7533 representation of the arguments so that their form can be
7534 studied. In any cases, the appropriate type conversions
7535 should be put back in the tree that will get out of the
7541 if (TREE_CODE_CLASS (code) == tcc_unary)
7543 if (TREE_CODE (arg0) == COMPOUND_EXPR)
7544 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
7545 fold_build1 (code, type, TREE_OPERAND (arg0, 1)));
7546 else if (TREE_CODE (arg0) == COND_EXPR)
7548 tree arg01 = TREE_OPERAND (arg0, 1);
7549 tree arg02 = TREE_OPERAND (arg0, 2);
7550 if (! VOID_TYPE_P (TREE_TYPE (arg01)))
7551 arg01 = fold_build1 (code, type, arg01);
7552 if (! VOID_TYPE_P (TREE_TYPE (arg02)))
7553 arg02 = fold_build1 (code, type, arg02);
7554 tem = fold_build3 (COND_EXPR, type, TREE_OPERAND (arg0, 0),
7557 /* If this was a conversion, and all we did was to move into
7558 inside the COND_EXPR, bring it back out. But leave it if
7559 it is a conversion from integer to integer and the
7560 result precision is no wider than a word since such a
7561 conversion is cheap and may be optimized away by combine,
7562 while it couldn't if it were outside the COND_EXPR. Then return
7563 so we don't get into an infinite recursion loop taking the
7564 conversion out and then back in. */
7566 if ((code == NOP_EXPR || code == CONVERT_EXPR
7567 || code == NON_LVALUE_EXPR)
7568 && TREE_CODE (tem) == COND_EXPR
7569 && TREE_CODE (TREE_OPERAND (tem, 1)) == code
7570 && TREE_CODE (TREE_OPERAND (tem, 2)) == code
7571 && ! VOID_TYPE_P (TREE_OPERAND (tem, 1))
7572 && ! VOID_TYPE_P (TREE_OPERAND (tem, 2))
7573 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))
7574 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 2), 0)))
7575 && (! (INTEGRAL_TYPE_P (TREE_TYPE (tem))
7577 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))))
7578 && TYPE_PRECISION (TREE_TYPE (tem)) <= BITS_PER_WORD)
7579 || flag_syntax_only))
7580 tem = build1 (code, type,
7582 TREE_TYPE (TREE_OPERAND
7583 (TREE_OPERAND (tem, 1), 0)),
7584 TREE_OPERAND (tem, 0),
7585 TREE_OPERAND (TREE_OPERAND (tem, 1), 0),
7586 TREE_OPERAND (TREE_OPERAND (tem, 2), 0)));
7589 else if (COMPARISON_CLASS_P (arg0))
7591 if (TREE_CODE (type) == BOOLEAN_TYPE)
7593 arg0 = copy_node (arg0);
7594 TREE_TYPE (arg0) = type;
7597 else if (TREE_CODE (type) != INTEGER_TYPE)
7598 return fold_build3 (COND_EXPR, type, arg0,
7599 fold_build1 (code, type,
7601 fold_build1 (code, type,
7602 integer_zero_node));
7611 case FIX_TRUNC_EXPR:
7612 if (TREE_TYPE (op0) == type)
7615 /* If we have (type) (a CMP b) and type is an integral type, return
7616 new expression involving the new type. */
7617 if (COMPARISON_CLASS_P (op0) && INTEGRAL_TYPE_P (type))
7618 return fold_build2 (TREE_CODE (op0), type, TREE_OPERAND (op0, 0),
7619 TREE_OPERAND (op0, 1));
7621 /* Handle cases of two conversions in a row. */
7622 if (TREE_CODE (op0) == NOP_EXPR
7623 || TREE_CODE (op0) == CONVERT_EXPR)
7625 tree inside_type = TREE_TYPE (TREE_OPERAND (op0, 0));
7626 tree inter_type = TREE_TYPE (op0);
7627 int inside_int = INTEGRAL_TYPE_P (inside_type);
7628 int inside_ptr = POINTER_TYPE_P (inside_type);
7629 int inside_float = FLOAT_TYPE_P (inside_type);
7630 int inside_vec = TREE_CODE (inside_type) == VECTOR_TYPE;
7631 unsigned int inside_prec = TYPE_PRECISION (inside_type);
7632 int inside_unsignedp = TYPE_UNSIGNED (inside_type);
7633 int inter_int = INTEGRAL_TYPE_P (inter_type);
7634 int inter_ptr = POINTER_TYPE_P (inter_type);
7635 int inter_float = FLOAT_TYPE_P (inter_type);
7636 int inter_vec = TREE_CODE (inter_type) == VECTOR_TYPE;
7637 unsigned int inter_prec = TYPE_PRECISION (inter_type);
7638 int inter_unsignedp = TYPE_UNSIGNED (inter_type);
7639 int final_int = INTEGRAL_TYPE_P (type);
7640 int final_ptr = POINTER_TYPE_P (type);
7641 int final_float = FLOAT_TYPE_P (type);
7642 int final_vec = TREE_CODE (type) == VECTOR_TYPE;
7643 unsigned int final_prec = TYPE_PRECISION (type);
7644 int final_unsignedp = TYPE_UNSIGNED (type);
7646 /* In addition to the cases of two conversions in a row
7647 handled below, if we are converting something to its own
7648 type via an object of identical or wider precision, neither
7649 conversion is needed. */
7650 if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (type)
7651 && (((inter_int || inter_ptr) && final_int)
7652 || (inter_float && final_float))
7653 && inter_prec >= final_prec)
7654 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
7656 /* Likewise, if the intermediate and final types are either both
7657 float or both integer, we don't need the middle conversion if
7658 it is wider than the final type and doesn't change the signedness
7659 (for integers). Avoid this if the final type is a pointer
7660 since then we sometimes need the inner conversion. Likewise if
7661 the outer has a precision not equal to the size of its mode. */
7662 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
7663 || (inter_float && inside_float)
7664 || (inter_vec && inside_vec))
7665 && inter_prec >= inside_prec
7666 && (inter_float || inter_vec
7667 || inter_unsignedp == inside_unsignedp)
7668 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
7669 && TYPE_MODE (type) == TYPE_MODE (inter_type))
7671 && (! final_vec || inter_prec == inside_prec))
7672 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
7674 /* If we have a sign-extension of a zero-extended value, we can
7675 replace that by a single zero-extension. */
7676 if (inside_int && inter_int && final_int
7677 && inside_prec < inter_prec && inter_prec < final_prec
7678 && inside_unsignedp && !inter_unsignedp)
7679 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
7681 /* Two conversions in a row are not needed unless:
7682 - some conversion is floating-point (overstrict for now), or
7683 - some conversion is a vector (overstrict for now), or
7684 - the intermediate type is narrower than both initial and
7686 - the intermediate type and innermost type differ in signedness,
7687 and the outermost type is wider than the intermediate, or
7688 - the initial type is a pointer type and the precisions of the
7689 intermediate and final types differ, or
7690 - the final type is a pointer type and the precisions of the
7691 initial and intermediate types differ.
7692 - the final type is a pointer type and the initial type not
7693 - the initial type is a pointer to an array and the final type
7695 if (! inside_float && ! inter_float && ! final_float
7696 && ! inside_vec && ! inter_vec && ! final_vec
7697 && (inter_prec >= inside_prec || inter_prec >= final_prec)
7698 && ! (inside_int && inter_int
7699 && inter_unsignedp != inside_unsignedp
7700 && inter_prec < final_prec)
7701 && ((inter_unsignedp && inter_prec > inside_prec)
7702 == (final_unsignedp && final_prec > inter_prec))
7703 && ! (inside_ptr && inter_prec != final_prec)
7704 && ! (final_ptr && inside_prec != inter_prec)
7705 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
7706 && TYPE_MODE (type) == TYPE_MODE (inter_type))
7707 && final_ptr == inside_ptr
7709 && TREE_CODE (TREE_TYPE (inside_type)) == ARRAY_TYPE
7710 && TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
7711 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
7714 /* Handle (T *)&A.B.C for A being of type T and B and C
7715 living at offset zero. This occurs frequently in
7716 C++ upcasting and then accessing the base. */
7717 if (TREE_CODE (op0) == ADDR_EXPR
7718 && POINTER_TYPE_P (type)
7719 && handled_component_p (TREE_OPERAND (op0, 0)))
7721 HOST_WIDE_INT bitsize, bitpos;
7723 enum machine_mode mode;
7724 int unsignedp, volatilep;
7725 tree base = TREE_OPERAND (op0, 0);
7726 base = get_inner_reference (base, &bitsize, &bitpos, &offset,
7727 &mode, &unsignedp, &volatilep, false);
7728 /* If the reference was to a (constant) zero offset, we can use
7729 the address of the base if it has the same base type
7730 as the result type. */
7731 if (! offset && bitpos == 0
7732 && TYPE_MAIN_VARIANT (TREE_TYPE (type))
7733 == TYPE_MAIN_VARIANT (TREE_TYPE (base)))
7734 return fold_convert (type, build_fold_addr_expr (base));
7737 if ((TREE_CODE (op0) == MODIFY_EXPR
7738 || TREE_CODE (op0) == GIMPLE_MODIFY_STMT)
7739 && TREE_CONSTANT (GENERIC_TREE_OPERAND (op0, 1))
7740 /* Detect assigning a bitfield. */
7741 && !(TREE_CODE (GENERIC_TREE_OPERAND (op0, 0)) == COMPONENT_REF
7743 (TREE_OPERAND (GENERIC_TREE_OPERAND (op0, 0), 1))))
7745 /* Don't leave an assignment inside a conversion
7746 unless assigning a bitfield. */
7747 tem = fold_build1 (code, type, GENERIC_TREE_OPERAND (op0, 1));
7748 /* First do the assignment, then return converted constant. */
7749 tem = build2 (COMPOUND_EXPR, TREE_TYPE (tem), op0, tem);
7750 TREE_NO_WARNING (tem) = 1;
7751 TREE_USED (tem) = 1;
7755 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
7756 constants (if x has signed type, the sign bit cannot be set
7757 in c). This folds extension into the BIT_AND_EXPR. */
7758 if (INTEGRAL_TYPE_P (type)
7759 && TREE_CODE (type) != BOOLEAN_TYPE
7760 && TREE_CODE (op0) == BIT_AND_EXPR
7761 && TREE_CODE (TREE_OPERAND (op0, 1)) == INTEGER_CST)
7764 tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
7767 if (TYPE_UNSIGNED (TREE_TYPE (and))
7768 || (TYPE_PRECISION (type)
7769 <= TYPE_PRECISION (TREE_TYPE (and))))
7771 else if (TYPE_PRECISION (TREE_TYPE (and1))
7772 <= HOST_BITS_PER_WIDE_INT
7773 && host_integerp (and1, 1))
7775 unsigned HOST_WIDE_INT cst;
7777 cst = tree_low_cst (and1, 1);
7778 cst &= (HOST_WIDE_INT) -1
7779 << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
7780 change = (cst == 0);
7781 #ifdef LOAD_EXTEND_OP
7783 && !flag_syntax_only
7784 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
7787 tree uns = lang_hooks.types.unsigned_type (TREE_TYPE (and0));
7788 and0 = fold_convert (uns, and0);
7789 and1 = fold_convert (uns, and1);
7795 tem = force_fit_type_double (type, TREE_INT_CST_LOW (and1),
7796 TREE_INT_CST_HIGH (and1), 0,
7797 TREE_OVERFLOW (and1));
7798 return fold_build2 (BIT_AND_EXPR, type,
7799 fold_convert (type, and0), tem);
7803 /* Convert (T1)((T2)X op Y) into (T1)X op Y, for pointer types T1 and
7804 T2 being pointers to types of the same size. */
7805 if (POINTER_TYPE_P (type)
7806 && BINARY_CLASS_P (arg0)
7807 && TREE_CODE (TREE_OPERAND (arg0, 0)) == NOP_EXPR
7808 && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 0))))
7810 tree arg00 = TREE_OPERAND (arg0, 0);
7812 tree t1 = TREE_TYPE (arg00);
7813 tree tt0 = TREE_TYPE (t0);
7814 tree tt1 = TREE_TYPE (t1);
7815 tree s0 = TYPE_SIZE (tt0);
7816 tree s1 = TYPE_SIZE (tt1);
7818 if (s0 && s1 && operand_equal_p (s0, s1, OEP_ONLY_CONST))
7819 return build2 (TREE_CODE (arg0), t0, fold_convert (t0, arg00),
7820 TREE_OPERAND (arg0, 1));
7823 /* Convert (T1)(~(T2)X) into ~(T1)X if T1 and T2 are integral types
7824 of the same precision, and X is a integer type not narrower than
7825 types T1 or T2, i.e. the cast (T2)X isn't an extension. */
7826 if (INTEGRAL_TYPE_P (type)
7827 && TREE_CODE (op0) == BIT_NOT_EXPR
7828 && INTEGRAL_TYPE_P (TREE_TYPE (op0))
7829 && (TREE_CODE (TREE_OPERAND (op0, 0)) == NOP_EXPR
7830 || TREE_CODE (TREE_OPERAND (op0, 0)) == CONVERT_EXPR)
7831 && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (op0)))
7833 tem = TREE_OPERAND (TREE_OPERAND (op0, 0), 0);
7834 if (INTEGRAL_TYPE_P (TREE_TYPE (tem))
7835 && TYPE_PRECISION (type) <= TYPE_PRECISION (TREE_TYPE (tem)))
7836 return fold_build1 (BIT_NOT_EXPR, type, fold_convert (type, tem));
7839 tem = fold_convert_const (code, type, arg0);
7840 return tem ? tem : NULL_TREE;
7842 case VIEW_CONVERT_EXPR:
7843 if (TREE_TYPE (op0) == type)
7845 if (TREE_CODE (op0) == VIEW_CONVERT_EXPR)
7846 return fold_build1 (VIEW_CONVERT_EXPR, type, TREE_OPERAND (op0, 0));
7847 return fold_view_convert_expr (type, op0);
7850 tem = fold_negate_expr (arg0);
7852 return fold_convert (type, tem);
7856 if (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST)
7857 return fold_abs_const (arg0, type);
7858 else if (TREE_CODE (arg0) == NEGATE_EXPR)
7859 return fold_build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0));
7860 /* Convert fabs((double)float) into (double)fabsf(float). */
7861 else if (TREE_CODE (arg0) == NOP_EXPR
7862 && TREE_CODE (type) == REAL_TYPE)
7864 tree targ0 = strip_float_extensions (arg0);
7866 return fold_convert (type, fold_build1 (ABS_EXPR,
7870 /* ABS_EXPR<ABS_EXPR<x>> = ABS_EXPR<x> even if flag_wrapv is on. */
7871 else if (TREE_CODE (arg0) == ABS_EXPR)
7873 else if (tree_expr_nonnegative_p (arg0))
7876 /* Strip sign ops from argument. */
7877 if (TREE_CODE (type) == REAL_TYPE)
7879 tem = fold_strip_sign_ops (arg0);
7881 return fold_build1 (ABS_EXPR, type, fold_convert (type, tem));
7886 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7887 return fold_convert (type, arg0);
7888 if (TREE_CODE (arg0) == COMPLEX_EXPR)
7890 tree itype = TREE_TYPE (type);
7891 tree rpart = fold_convert (itype, TREE_OPERAND (arg0, 0));
7892 tree ipart = fold_convert (itype, TREE_OPERAND (arg0, 1));
7893 return fold_build2 (COMPLEX_EXPR, type, rpart, negate_expr (ipart));
7895 if (TREE_CODE (arg0) == COMPLEX_CST)
7897 tree itype = TREE_TYPE (type);
7898 tree rpart = fold_convert (itype, TREE_REALPART (arg0));
7899 tree ipart = fold_convert (itype, TREE_IMAGPART (arg0));
7900 return build_complex (type, rpart, negate_expr (ipart));
7902 if (TREE_CODE (arg0) == CONJ_EXPR)
7903 return fold_convert (type, TREE_OPERAND (arg0, 0));
7907 if (TREE_CODE (arg0) == INTEGER_CST)
7908 return fold_not_const (arg0, type);
7909 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
7910 return TREE_OPERAND (arg0, 0);
7911 /* Convert ~ (-A) to A - 1. */
7912 else if (INTEGRAL_TYPE_P (type) && TREE_CODE (arg0) == NEGATE_EXPR)
7913 return fold_build2 (MINUS_EXPR, type, TREE_OPERAND (arg0, 0),
7914 build_int_cst (type, 1));
7915 /* Convert ~ (A - 1) or ~ (A + -1) to -A. */
7916 else if (INTEGRAL_TYPE_P (type)
7917 && ((TREE_CODE (arg0) == MINUS_EXPR
7918 && integer_onep (TREE_OPERAND (arg0, 1)))
7919 || (TREE_CODE (arg0) == PLUS_EXPR
7920 && integer_all_onesp (TREE_OPERAND (arg0, 1)))))
7921 return fold_build1 (NEGATE_EXPR, type, TREE_OPERAND (arg0, 0));
7922 /* Convert ~(X ^ Y) to ~X ^ Y or X ^ ~Y if ~X or ~Y simplify. */
7923 else if (TREE_CODE (arg0) == BIT_XOR_EXPR
7924 && (tem = fold_unary (BIT_NOT_EXPR, type,
7926 TREE_OPERAND (arg0, 0)))))
7927 return fold_build2 (BIT_XOR_EXPR, type, tem,
7928 fold_convert (type, TREE_OPERAND (arg0, 1)));
7929 else if (TREE_CODE (arg0) == BIT_XOR_EXPR
7930 && (tem = fold_unary (BIT_NOT_EXPR, type,
7932 TREE_OPERAND (arg0, 1)))))
7933 return fold_build2 (BIT_XOR_EXPR, type,
7934 fold_convert (type, TREE_OPERAND (arg0, 0)), tem);
7938 case TRUTH_NOT_EXPR:
7939 /* The argument to invert_truthvalue must have Boolean type. */
7940 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
7941 arg0 = fold_convert (boolean_type_node, arg0);
7943 /* Note that the operand of this must be an int
7944 and its values must be 0 or 1.
7945 ("true" is a fixed value perhaps depending on the language,
7946 but we don't handle values other than 1 correctly yet.) */
7947 tem = fold_truth_not_expr (arg0);
7950 return fold_convert (type, tem);
7953 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7954 return fold_convert (type, arg0);
7955 if (TREE_CODE (arg0) == COMPLEX_EXPR)
7956 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
7957 TREE_OPERAND (arg0, 1));
7958 if (TREE_CODE (arg0) == COMPLEX_CST)
7959 return fold_convert (type, TREE_REALPART (arg0));
7960 if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7962 tree itype = TREE_TYPE (TREE_TYPE (arg0));
7963 tem = fold_build2 (TREE_CODE (arg0), itype,
7964 fold_build1 (REALPART_EXPR, itype,
7965 TREE_OPERAND (arg0, 0)),
7966 fold_build1 (REALPART_EXPR, itype,
7967 TREE_OPERAND (arg0, 1)));
7968 return fold_convert (type, tem);
7970 if (TREE_CODE (arg0) == CONJ_EXPR)
7972 tree itype = TREE_TYPE (TREE_TYPE (arg0));
7973 tem = fold_build1 (REALPART_EXPR, itype, TREE_OPERAND (arg0, 0));
7974 return fold_convert (type, tem);
7976 if (TREE_CODE (arg0) == CALL_EXPR)
7978 tree fn = get_callee_fndecl (arg0);
7979 if (DECL_BUILT_IN_CLASS (fn) == BUILT_IN_NORMAL)
7980 switch (DECL_FUNCTION_CODE (fn))
7982 CASE_FLT_FN (BUILT_IN_CEXPI):
7983 fn = mathfn_built_in (type, BUILT_IN_COS);
7985 return build_call_expr (fn, 1, CALL_EXPR_ARG (arg0, 0));
7995 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7996 return fold_convert (type, integer_zero_node);
7997 if (TREE_CODE (arg0) == COMPLEX_EXPR)
7998 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
7999 TREE_OPERAND (arg0, 0));
8000 if (TREE_CODE (arg0) == COMPLEX_CST)
8001 return fold_convert (type, TREE_IMAGPART (arg0));
8002 if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8004 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8005 tem = fold_build2 (TREE_CODE (arg0), itype,
8006 fold_build1 (IMAGPART_EXPR, itype,
8007 TREE_OPERAND (arg0, 0)),
8008 fold_build1 (IMAGPART_EXPR, itype,
8009 TREE_OPERAND (arg0, 1)));
8010 return fold_convert (type, tem);
8012 if (TREE_CODE (arg0) == CONJ_EXPR)
8014 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8015 tem = fold_build1 (IMAGPART_EXPR, itype, TREE_OPERAND (arg0, 0));
8016 return fold_convert (type, negate_expr (tem));
8018 if (TREE_CODE (arg0) == CALL_EXPR)
8020 tree fn = get_callee_fndecl (arg0);
8021 if (DECL_BUILT_IN_CLASS (fn) == BUILT_IN_NORMAL)
8022 switch (DECL_FUNCTION_CODE (fn))
8024 CASE_FLT_FN (BUILT_IN_CEXPI):
8025 fn = mathfn_built_in (type, BUILT_IN_SIN);
8027 return build_call_expr (fn, 1, CALL_EXPR_ARG (arg0, 0));
8038 } /* switch (code) */
8041 /* Fold a binary expression of code CODE and type TYPE with operands
8042 OP0 and OP1, containing either a MIN-MAX or a MAX-MIN combination.
8043 Return the folded expression if folding is successful. Otherwise,
8044 return NULL_TREE. */
8047 fold_minmax (enum tree_code code, tree type, tree op0, tree op1)
8049 enum tree_code compl_code;
8051 if (code == MIN_EXPR)
8052 compl_code = MAX_EXPR;
8053 else if (code == MAX_EXPR)
8054 compl_code = MIN_EXPR;
8058 /* MIN (MAX (a, b), b) == b. */
8059 if (TREE_CODE (op0) == compl_code
8060 && operand_equal_p (TREE_OPERAND (op0, 1), op1, 0))
8061 return omit_one_operand (type, op1, TREE_OPERAND (op0, 0));
8063 /* MIN (MAX (b, a), b) == b. */
8064 if (TREE_CODE (op0) == compl_code
8065 && operand_equal_p (TREE_OPERAND (op0, 0), op1, 0)
8066 && reorder_operands_p (TREE_OPERAND (op0, 1), op1))
8067 return omit_one_operand (type, op1, TREE_OPERAND (op0, 1));
8069 /* MIN (a, MAX (a, b)) == a. */
8070 if (TREE_CODE (op1) == compl_code
8071 && operand_equal_p (op0, TREE_OPERAND (op1, 0), 0)
8072 && reorder_operands_p (op0, TREE_OPERAND (op1, 1)))
8073 return omit_one_operand (type, op0, TREE_OPERAND (op1, 1));
8075 /* MIN (a, MAX (b, a)) == a. */
8076 if (TREE_CODE (op1) == compl_code
8077 && operand_equal_p (op0, TREE_OPERAND (op1, 1), 0)
8078 && reorder_operands_p (op0, TREE_OPERAND (op1, 0)))
8079 return omit_one_operand (type, op0, TREE_OPERAND (op1, 0));
8084 /* Helper that tries to canonicalize the comparison ARG0 CODE ARG1
8085 by changing CODE to reduce the magnitude of constants involved in
8086 ARG0 of the comparison.
8087 Returns a canonicalized comparison tree if a simplification was
8088 possible, otherwise returns NULL_TREE.
8089 Set *STRICT_OVERFLOW_P to true if the canonicalization is only
8090 valid if signed overflow is undefined. */
8093 maybe_canonicalize_comparison_1 (enum tree_code code, tree type,
8094 tree arg0, tree arg1,
8095 bool *strict_overflow_p)
8097 enum tree_code code0 = TREE_CODE (arg0);
8098 tree t, cst0 = NULL_TREE;
8102 /* Match A +- CST code arg1 and CST code arg1. */
8103 if (!(((code0 == MINUS_EXPR
8104 || code0 == PLUS_EXPR)
8105 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8106 || code0 == INTEGER_CST))
8109 /* Identify the constant in arg0 and its sign. */
8110 if (code0 == INTEGER_CST)
8113 cst0 = TREE_OPERAND (arg0, 1);
8114 sgn0 = tree_int_cst_sgn (cst0);
8116 /* Overflowed constants and zero will cause problems. */
8117 if (integer_zerop (cst0)
8118 || TREE_OVERFLOW (cst0))
8121 /* See if we can reduce the magnitude of the constant in
8122 arg0 by changing the comparison code. */
8123 if (code0 == INTEGER_CST)
8125 /* CST <= arg1 -> CST-1 < arg1. */
8126 if (code == LE_EXPR && sgn0 == 1)
8128 /* -CST < arg1 -> -CST-1 <= arg1. */
8129 else if (code == LT_EXPR && sgn0 == -1)
8131 /* CST > arg1 -> CST-1 >= arg1. */
8132 else if (code == GT_EXPR && sgn0 == 1)
8134 /* -CST >= arg1 -> -CST-1 > arg1. */
8135 else if (code == GE_EXPR && sgn0 == -1)
8139 /* arg1 code' CST' might be more canonical. */
8144 /* A - CST < arg1 -> A - CST-1 <= arg1. */
8146 && code0 == ((sgn0 == -1) ? PLUS_EXPR : MINUS_EXPR))
8148 /* A + CST > arg1 -> A + CST-1 >= arg1. */
8149 else if (code == GT_EXPR
8150 && code0 == ((sgn0 == -1) ? MINUS_EXPR : PLUS_EXPR))
8152 /* A + CST <= arg1 -> A + CST-1 < arg1. */
8153 else if (code == LE_EXPR
8154 && code0 == ((sgn0 == -1) ? MINUS_EXPR : PLUS_EXPR))
8156 /* A - CST >= arg1 -> A - CST-1 > arg1. */
8157 else if (code == GE_EXPR
8158 && code0 == ((sgn0 == -1) ? PLUS_EXPR : MINUS_EXPR))
8162 *strict_overflow_p = true;
8165 /* Now build the constant reduced in magnitude. */
8166 t = int_const_binop (sgn0 == -1 ? PLUS_EXPR : MINUS_EXPR,
8167 cst0, build_int_cst (TREE_TYPE (cst0), 1), 0);
8168 if (code0 != INTEGER_CST)
8169 t = fold_build2 (code0, TREE_TYPE (arg0), TREE_OPERAND (arg0, 0), t);
8171 /* If swapping might yield to a more canonical form, do so. */
8173 return fold_build2 (swap_tree_comparison (code), type, arg1, t);
8175 return fold_build2 (code, type, t, arg1);
8178 /* Canonicalize the comparison ARG0 CODE ARG1 with type TYPE with undefined
8179 overflow further. Try to decrease the magnitude of constants involved
8180 by changing LE_EXPR and GE_EXPR to LT_EXPR and GT_EXPR or vice versa
8181 and put sole constants at the second argument position.
8182 Returns the canonicalized tree if changed, otherwise NULL_TREE. */
8185 maybe_canonicalize_comparison (enum tree_code code, tree type,
8186 tree arg0, tree arg1)
8189 bool strict_overflow_p;
8190 const char * const warnmsg = G_("assuming signed overflow does not occur "
8191 "when reducing constant in comparison");
8193 /* In principle pointers also have undefined overflow behavior,
8194 but that causes problems elsewhere. */
8195 if (!TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))
8196 || POINTER_TYPE_P (TREE_TYPE (arg0)))
8199 /* Try canonicalization by simplifying arg0. */
8200 strict_overflow_p = false;
8201 t = maybe_canonicalize_comparison_1 (code, type, arg0, arg1,
8202 &strict_overflow_p);
8205 if (strict_overflow_p)
8206 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MAGNITUDE);
8210 /* Try canonicalization by simplifying arg1 using the swapped
8212 code = swap_tree_comparison (code);
8213 strict_overflow_p = false;
8214 t = maybe_canonicalize_comparison_1 (code, type, arg1, arg0,
8215 &strict_overflow_p);
8216 if (t && strict_overflow_p)
8217 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MAGNITUDE);
8221 /* Subroutine of fold_binary. This routine performs all of the
8222 transformations that are common to the equality/inequality
8223 operators (EQ_EXPR and NE_EXPR) and the ordering operators
8224 (LT_EXPR, LE_EXPR, GE_EXPR and GT_EXPR). Callers other than
8225 fold_binary should call fold_binary. Fold a comparison with
8226 tree code CODE and type TYPE with operands OP0 and OP1. Return
8227 the folded comparison or NULL_TREE. */
8230 fold_comparison (enum tree_code code, tree type, tree op0, tree op1)
8232 tree arg0, arg1, tem;
8237 STRIP_SIGN_NOPS (arg0);
8238 STRIP_SIGN_NOPS (arg1);
8240 tem = fold_relational_const (code, type, arg0, arg1);
8241 if (tem != NULL_TREE)
8244 /* If one arg is a real or integer constant, put it last. */
8245 if (tree_swap_operands_p (arg0, arg1, true))
8246 return fold_build2 (swap_tree_comparison (code), type, op1, op0);
8248 /* Transform comparisons of the form X +- C1 CMP C2 to X CMP C2 +- C1. */
8249 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8250 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8251 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
8252 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
8253 && (TREE_CODE (arg1) == INTEGER_CST
8254 && !TREE_OVERFLOW (arg1)))
8256 tree const1 = TREE_OPERAND (arg0, 1);
8258 tree variable = TREE_OPERAND (arg0, 0);
8261 lhs_add = TREE_CODE (arg0) != PLUS_EXPR;
8263 lhs = fold_build2 (lhs_add ? PLUS_EXPR : MINUS_EXPR,
8264 TREE_TYPE (arg1), const2, const1);
8266 /* If the constant operation overflowed this can be
8267 simplified as a comparison against INT_MAX/INT_MIN. */
8268 if (TREE_CODE (lhs) == INTEGER_CST
8269 && TREE_OVERFLOW (lhs))
8271 int const1_sgn = tree_int_cst_sgn (const1);
8272 enum tree_code code2 = code;
8274 /* Get the sign of the constant on the lhs if the
8275 operation were VARIABLE + CONST1. */
8276 if (TREE_CODE (arg0) == MINUS_EXPR)
8277 const1_sgn = -const1_sgn;
8279 /* The sign of the constant determines if we overflowed
8280 INT_MAX (const1_sgn == -1) or INT_MIN (const1_sgn == 1).
8281 Canonicalize to the INT_MIN overflow by swapping the comparison
8283 if (const1_sgn == -1)
8284 code2 = swap_tree_comparison (code);
8286 /* We now can look at the canonicalized case
8287 VARIABLE + 1 CODE2 INT_MIN
8288 and decide on the result. */
8289 if (code2 == LT_EXPR
8291 || code2 == EQ_EXPR)
8292 return omit_one_operand (type, boolean_false_node, variable);
8293 else if (code2 == NE_EXPR
8295 || code2 == GT_EXPR)
8296 return omit_one_operand (type, boolean_true_node, variable);
8299 if (TREE_CODE (lhs) == TREE_CODE (arg1)
8300 && (TREE_CODE (lhs) != INTEGER_CST
8301 || !TREE_OVERFLOW (lhs)))
8303 fold_overflow_warning (("assuming signed overflow does not occur "
8304 "when changing X +- C1 cmp C2 to "
8306 WARN_STRICT_OVERFLOW_COMPARISON);
8307 return fold_build2 (code, type, variable, lhs);
8311 /* For comparisons of pointers we can decompose it to a compile time
8312 comparison of the base objects and the offsets into the object.
8313 This requires at least one operand being an ADDR_EXPR to do more
8314 than the operand_equal_p test below. */
8315 if (POINTER_TYPE_P (TREE_TYPE (arg0))
8316 && (TREE_CODE (arg0) == ADDR_EXPR
8317 || TREE_CODE (arg1) == ADDR_EXPR))
8319 tree base0, base1, offset0 = NULL_TREE, offset1 = NULL_TREE;
8320 HOST_WIDE_INT bitsize, bitpos0 = 0, bitpos1 = 0;
8321 enum machine_mode mode;
8322 int volatilep, unsignedp;
8323 bool indirect_base0 = false;
8325 /* Get base and offset for the access. Strip ADDR_EXPR for
8326 get_inner_reference, but put it back by stripping INDIRECT_REF
8327 off the base object if possible. */
8329 if (TREE_CODE (arg0) == ADDR_EXPR)
8331 base0 = get_inner_reference (TREE_OPERAND (arg0, 0),
8332 &bitsize, &bitpos0, &offset0, &mode,
8333 &unsignedp, &volatilep, false);
8334 if (TREE_CODE (base0) == INDIRECT_REF)
8335 base0 = TREE_OPERAND (base0, 0);
8337 indirect_base0 = true;
8341 if (TREE_CODE (arg1) == ADDR_EXPR)
8343 base1 = get_inner_reference (TREE_OPERAND (arg1, 0),
8344 &bitsize, &bitpos1, &offset1, &mode,
8345 &unsignedp, &volatilep, false);
8346 /* We have to make sure to have an indirect/non-indirect base1
8347 just the same as we did for base0. */
8348 if (TREE_CODE (base1) == INDIRECT_REF
8350 base1 = TREE_OPERAND (base1, 0);
8351 else if (!indirect_base0)
8354 else if (indirect_base0)
8357 /* If we have equivalent bases we might be able to simplify. */
8359 && operand_equal_p (base0, base1, 0))
8361 /* We can fold this expression to a constant if the non-constant
8362 offset parts are equal. */
8363 if (offset0 == offset1
8364 || (offset0 && offset1
8365 && operand_equal_p (offset0, offset1, 0)))
8370 return build_int_cst (boolean_type_node, bitpos0 == bitpos1);
8372 return build_int_cst (boolean_type_node, bitpos0 != bitpos1);
8374 return build_int_cst (boolean_type_node, bitpos0 < bitpos1);
8376 return build_int_cst (boolean_type_node, bitpos0 <= bitpos1);
8378 return build_int_cst (boolean_type_node, bitpos0 >= bitpos1);
8380 return build_int_cst (boolean_type_node, bitpos0 > bitpos1);
8384 /* We can simplify the comparison to a comparison of the variable
8385 offset parts if the constant offset parts are equal.
8386 Be careful to use signed size type here because otherwise we
8387 mess with array offsets in the wrong way. This is possible
8388 because pointer arithmetic is restricted to retain within an
8389 object and overflow on pointer differences is undefined as of
8390 6.5.6/8 and /9 with respect to the signed ptrdiff_t. */
8391 else if (bitpos0 == bitpos1)
8393 tree signed_size_type_node;
8394 signed_size_type_node = signed_type_for (size_type_node);
8396 /* By converting to signed size type we cover middle-end pointer
8397 arithmetic which operates on unsigned pointer types of size
8398 type size and ARRAY_REF offsets which are properly sign or
8399 zero extended from their type in case it is narrower than
8401 if (offset0 == NULL_TREE)
8402 offset0 = build_int_cst (signed_size_type_node, 0);
8404 offset0 = fold_convert (signed_size_type_node, offset0);
8405 if (offset1 == NULL_TREE)
8406 offset1 = build_int_cst (signed_size_type_node, 0);
8408 offset1 = fold_convert (signed_size_type_node, offset1);
8410 return fold_build2 (code, type, offset0, offset1);
8415 /* If this is a comparison of two exprs that look like an ARRAY_REF of the
8416 same object, then we can fold this to a comparison of the two offsets in
8417 signed size type. This is possible because pointer arithmetic is
8418 restricted to retain within an object and overflow on pointer differences
8419 is undefined as of 6.5.6/8 and /9 with respect to the signed ptrdiff_t.
8421 We check flag_wrapv directly because pointers types are unsigned,
8422 and therefore TYPE_OVERFLOW_WRAPS returns true for them. That is
8423 normally what we want to avoid certain odd overflow cases, but
8425 if (POINTER_TYPE_P (TREE_TYPE (arg0))
8427 && !TYPE_OVERFLOW_TRAPS (TREE_TYPE (arg0)))
8429 tree base0, offset0, base1, offset1;
8431 if (extract_array_ref (arg0, &base0, &offset0)
8432 && extract_array_ref (arg1, &base1, &offset1)
8433 && operand_equal_p (base0, base1, 0))
8435 tree signed_size_type_node;
8436 signed_size_type_node = signed_type_for (size_type_node);
8438 /* By converting to signed size type we cover middle-end pointer
8439 arithmetic which operates on unsigned pointer types of size
8440 type size and ARRAY_REF offsets which are properly sign or
8441 zero extended from their type in case it is narrower than
8443 if (offset0 == NULL_TREE)
8444 offset0 = build_int_cst (signed_size_type_node, 0);
8446 offset0 = fold_convert (signed_size_type_node, offset0);
8447 if (offset1 == NULL_TREE)
8448 offset1 = build_int_cst (signed_size_type_node, 0);
8450 offset1 = fold_convert (signed_size_type_node, offset1);
8452 return fold_build2 (code, type, offset0, offset1);
8456 /* Transform comparisons of the form X +- C1 CMP Y +- C2 to
8457 X CMP Y +- C2 +- C1 for signed X, Y. This is valid if
8458 the resulting offset is smaller in absolute value than the
8460 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))
8461 && (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8462 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8463 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1)))
8464 && (TREE_CODE (arg1) == PLUS_EXPR || TREE_CODE (arg1) == MINUS_EXPR)
8465 && (TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
8466 && !TREE_OVERFLOW (TREE_OPERAND (arg1, 1))))
8468 tree const1 = TREE_OPERAND (arg0, 1);
8469 tree const2 = TREE_OPERAND (arg1, 1);
8470 tree variable1 = TREE_OPERAND (arg0, 0);
8471 tree variable2 = TREE_OPERAND (arg1, 0);
8473 const char * const warnmsg = G_("assuming signed overflow does not "
8474 "occur when combining constants around "
8477 /* Put the constant on the side where it doesn't overflow and is
8478 of lower absolute value than before. */
8479 cst = int_const_binop (TREE_CODE (arg0) == TREE_CODE (arg1)
8480 ? MINUS_EXPR : PLUS_EXPR,
8482 if (!TREE_OVERFLOW (cst)
8483 && tree_int_cst_compare (const2, cst) == tree_int_cst_sgn (const2))
8485 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
8486 return fold_build2 (code, type,
8488 fold_build2 (TREE_CODE (arg1), TREE_TYPE (arg1),
8492 cst = int_const_binop (TREE_CODE (arg0) == TREE_CODE (arg1)
8493 ? MINUS_EXPR : PLUS_EXPR,
8495 if (!TREE_OVERFLOW (cst)
8496 && tree_int_cst_compare (const1, cst) == tree_int_cst_sgn (const1))
8498 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
8499 return fold_build2 (code, type,
8500 fold_build2 (TREE_CODE (arg0), TREE_TYPE (arg0),
8506 /* Transform comparisons of the form X * C1 CMP 0 to X CMP 0 in the
8507 signed arithmetic case. That form is created by the compiler
8508 often enough for folding it to be of value. One example is in
8509 computing loop trip counts after Operator Strength Reduction. */
8510 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))
8511 && TREE_CODE (arg0) == MULT_EXPR
8512 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8513 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1)))
8514 && integer_zerop (arg1))
8516 tree const1 = TREE_OPERAND (arg0, 1);
8517 tree const2 = arg1; /* zero */
8518 tree variable1 = TREE_OPERAND (arg0, 0);
8519 enum tree_code cmp_code = code;
8521 gcc_assert (!integer_zerop (const1));
8523 fold_overflow_warning (("assuming signed overflow does not occur when "
8524 "eliminating multiplication in comparison "
8526 WARN_STRICT_OVERFLOW_COMPARISON);
8528 /* If const1 is negative we swap the sense of the comparison. */
8529 if (tree_int_cst_sgn (const1) < 0)
8530 cmp_code = swap_tree_comparison (cmp_code);
8532 return fold_build2 (cmp_code, type, variable1, const2);
8535 tem = maybe_canonicalize_comparison (code, type, arg0, arg1);
8539 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
8541 tree targ0 = strip_float_extensions (arg0);
8542 tree targ1 = strip_float_extensions (arg1);
8543 tree newtype = TREE_TYPE (targ0);
8545 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
8546 newtype = TREE_TYPE (targ1);
8548 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
8549 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
8550 return fold_build2 (code, type, fold_convert (newtype, targ0),
8551 fold_convert (newtype, targ1));
8553 /* (-a) CMP (-b) -> b CMP a */
8554 if (TREE_CODE (arg0) == NEGATE_EXPR
8555 && TREE_CODE (arg1) == NEGATE_EXPR)
8556 return fold_build2 (code, type, TREE_OPERAND (arg1, 0),
8557 TREE_OPERAND (arg0, 0));
8559 if (TREE_CODE (arg1) == REAL_CST)
8561 REAL_VALUE_TYPE cst;
8562 cst = TREE_REAL_CST (arg1);
8564 /* (-a) CMP CST -> a swap(CMP) (-CST) */
8565 if (TREE_CODE (arg0) == NEGATE_EXPR)
8566 return fold_build2 (swap_tree_comparison (code), type,
8567 TREE_OPERAND (arg0, 0),
8568 build_real (TREE_TYPE (arg1),
8569 REAL_VALUE_NEGATE (cst)));
8571 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
8572 /* a CMP (-0) -> a CMP 0 */
8573 if (REAL_VALUE_MINUS_ZERO (cst))
8574 return fold_build2 (code, type, arg0,
8575 build_real (TREE_TYPE (arg1), dconst0));
8577 /* x != NaN is always true, other ops are always false. */
8578 if (REAL_VALUE_ISNAN (cst)
8579 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))))
8581 tem = (code == NE_EXPR) ? integer_one_node : integer_zero_node;
8582 return omit_one_operand (type, tem, arg0);
8585 /* Fold comparisons against infinity. */
8586 if (REAL_VALUE_ISINF (cst))
8588 tem = fold_inf_compare (code, type, arg0, arg1);
8589 if (tem != NULL_TREE)
8594 /* If this is a comparison of a real constant with a PLUS_EXPR
8595 or a MINUS_EXPR of a real constant, we can convert it into a
8596 comparison with a revised real constant as long as no overflow
8597 occurs when unsafe_math_optimizations are enabled. */
8598 if (flag_unsafe_math_optimizations
8599 && TREE_CODE (arg1) == REAL_CST
8600 && (TREE_CODE (arg0) == PLUS_EXPR
8601 || TREE_CODE (arg0) == MINUS_EXPR)
8602 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
8603 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
8604 ? MINUS_EXPR : PLUS_EXPR,
8605 arg1, TREE_OPERAND (arg0, 1), 0))
8606 && !TREE_OVERFLOW (tem))
8607 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
8609 /* Likewise, we can simplify a comparison of a real constant with
8610 a MINUS_EXPR whose first operand is also a real constant, i.e.
8611 (c1 - x) < c2 becomes x > c1-c2. */
8612 if (flag_unsafe_math_optimizations
8613 && TREE_CODE (arg1) == REAL_CST
8614 && TREE_CODE (arg0) == MINUS_EXPR
8615 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST
8616 && 0 != (tem = const_binop (MINUS_EXPR, TREE_OPERAND (arg0, 0),
8618 && !TREE_OVERFLOW (tem))
8619 return fold_build2 (swap_tree_comparison (code), type,
8620 TREE_OPERAND (arg0, 1), tem);
8622 /* Fold comparisons against built-in math functions. */
8623 if (TREE_CODE (arg1) == REAL_CST
8624 && flag_unsafe_math_optimizations
8625 && ! flag_errno_math)
8627 enum built_in_function fcode = builtin_mathfn_code (arg0);
8629 if (fcode != END_BUILTINS)
8631 tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
8632 if (tem != NULL_TREE)
8638 /* Convert foo++ == CONST into ++foo == CONST + INCR. */
8639 if (TREE_CONSTANT (arg1)
8640 && (TREE_CODE (arg0) == POSTINCREMENT_EXPR
8641 || TREE_CODE (arg0) == POSTDECREMENT_EXPR)
8642 /* This optimization is invalid for ordered comparisons
8643 if CONST+INCR overflows or if foo+incr might overflow.
8644 This optimization is invalid for floating point due to rounding.
8645 For pointer types we assume overflow doesn't happen. */
8646 && (POINTER_TYPE_P (TREE_TYPE (arg0))
8647 || (INTEGRAL_TYPE_P (TREE_TYPE (arg0))
8648 && (code == EQ_EXPR || code == NE_EXPR))))
8650 tree varop, newconst;
8652 if (TREE_CODE (arg0) == POSTINCREMENT_EXPR)
8654 newconst = fold_build2 (PLUS_EXPR, TREE_TYPE (arg0),
8655 arg1, TREE_OPERAND (arg0, 1));
8656 varop = build2 (PREINCREMENT_EXPR, TREE_TYPE (arg0),
8657 TREE_OPERAND (arg0, 0),
8658 TREE_OPERAND (arg0, 1));
8662 newconst = fold_build2 (MINUS_EXPR, TREE_TYPE (arg0),
8663 arg1, TREE_OPERAND (arg0, 1));
8664 varop = build2 (PREDECREMENT_EXPR, TREE_TYPE (arg0),
8665 TREE_OPERAND (arg0, 0),
8666 TREE_OPERAND (arg0, 1));
8670 /* If VAROP is a reference to a bitfield, we must mask
8671 the constant by the width of the field. */
8672 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
8673 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (varop, 0), 1))
8674 && host_integerp (DECL_SIZE (TREE_OPERAND
8675 (TREE_OPERAND (varop, 0), 1)), 1))
8677 tree fielddecl = TREE_OPERAND (TREE_OPERAND (varop, 0), 1);
8678 HOST_WIDE_INT size = tree_low_cst (DECL_SIZE (fielddecl), 1);
8679 tree folded_compare, shift;
8681 /* First check whether the comparison would come out
8682 always the same. If we don't do that we would
8683 change the meaning with the masking. */
8684 folded_compare = fold_build2 (code, type,
8685 TREE_OPERAND (varop, 0), arg1);
8686 if (TREE_CODE (folded_compare) == INTEGER_CST)
8687 return omit_one_operand (type, folded_compare, varop);
8689 shift = build_int_cst (NULL_TREE,
8690 TYPE_PRECISION (TREE_TYPE (varop)) - size);
8691 shift = fold_convert (TREE_TYPE (varop), shift);
8692 newconst = fold_build2 (LSHIFT_EXPR, TREE_TYPE (varop),
8694 newconst = fold_build2 (RSHIFT_EXPR, TREE_TYPE (varop),
8698 return fold_build2 (code, type, varop, newconst);
8701 if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
8702 && (TREE_CODE (arg0) == NOP_EXPR
8703 || TREE_CODE (arg0) == CONVERT_EXPR))
8705 /* If we are widening one operand of an integer comparison,
8706 see if the other operand is similarly being widened. Perhaps we
8707 can do the comparison in the narrower type. */
8708 tem = fold_widened_comparison (code, type, arg0, arg1);
8712 /* Or if we are changing signedness. */
8713 tem = fold_sign_changed_comparison (code, type, arg0, arg1);
8718 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
8719 constant, we can simplify it. */
8720 if (TREE_CODE (arg1) == INTEGER_CST
8721 && (TREE_CODE (arg0) == MIN_EXPR
8722 || TREE_CODE (arg0) == MAX_EXPR)
8723 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8725 tem = optimize_minmax_comparison (code, type, op0, op1);
8730 /* Simplify comparison of something with itself. (For IEEE
8731 floating-point, we can only do some of these simplifications.) */
8732 if (operand_equal_p (arg0, arg1, 0))
8737 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
8738 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8739 return constant_boolean_node (1, type);
8744 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
8745 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8746 return constant_boolean_node (1, type);
8747 return fold_build2 (EQ_EXPR, type, arg0, arg1);
8750 /* For NE, we can only do this simplification if integer
8751 or we don't honor IEEE floating point NaNs. */
8752 if (FLOAT_TYPE_P (TREE_TYPE (arg0))
8753 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8755 /* ... fall through ... */
8758 return constant_boolean_node (0, type);
8764 /* If we are comparing an expression that just has comparisons
8765 of two integer values, arithmetic expressions of those comparisons,
8766 and constants, we can simplify it. There are only three cases
8767 to check: the two values can either be equal, the first can be
8768 greater, or the second can be greater. Fold the expression for
8769 those three values. Since each value must be 0 or 1, we have
8770 eight possibilities, each of which corresponds to the constant 0
8771 or 1 or one of the six possible comparisons.
8773 This handles common cases like (a > b) == 0 but also handles
8774 expressions like ((x > y) - (y > x)) > 0, which supposedly
8775 occur in macroized code. */
8777 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
8779 tree cval1 = 0, cval2 = 0;
8782 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
8783 /* Don't handle degenerate cases here; they should already
8784 have been handled anyway. */
8785 && cval1 != 0 && cval2 != 0
8786 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
8787 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
8788 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
8789 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
8790 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
8791 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
8792 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
8794 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
8795 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
8797 /* We can't just pass T to eval_subst in case cval1 or cval2
8798 was the same as ARG1. */
8801 = fold_build2 (code, type,
8802 eval_subst (arg0, cval1, maxval,
8806 = fold_build2 (code, type,
8807 eval_subst (arg0, cval1, maxval,
8811 = fold_build2 (code, type,
8812 eval_subst (arg0, cval1, minval,
8816 /* All three of these results should be 0 or 1. Confirm they are.
8817 Then use those values to select the proper code to use. */
8819 if (TREE_CODE (high_result) == INTEGER_CST
8820 && TREE_CODE (equal_result) == INTEGER_CST
8821 && TREE_CODE (low_result) == INTEGER_CST)
8823 /* Make a 3-bit mask with the high-order bit being the
8824 value for `>', the next for '=', and the low for '<'. */
8825 switch ((integer_onep (high_result) * 4)
8826 + (integer_onep (equal_result) * 2)
8827 + integer_onep (low_result))
8831 return omit_one_operand (type, integer_zero_node, arg0);
8852 return omit_one_operand (type, integer_one_node, arg0);
8856 return save_expr (build2 (code, type, cval1, cval2));
8857 return fold_build2 (code, type, cval1, cval2);
8862 /* If this is a comparison of complex values and both sides
8863 are COMPLEX_CST, do the comparison by parts to fold the
8865 if ((code == EQ_EXPR || code == NE_EXPR)
8866 && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
8867 && TREE_CODE (arg0) == COMPLEX_CST
8868 && TREE_CODE (arg1) == COMPLEX_CST)
8870 tree real0, imag0, real1, imag1;
8871 enum tree_code outercode;
8873 real0 = TREE_REALPART (arg0);
8874 imag0 = TREE_IMAGPART (arg0);
8875 real1 = TREE_REALPART (arg1);
8876 imag1 = TREE_IMAGPART (arg1);
8877 outercode = code == EQ_EXPR ? TRUTH_ANDIF_EXPR : TRUTH_ORIF_EXPR;
8879 return fold_build2 (outercode, type,
8880 fold_build2 (code, type, real0, real1),
8881 fold_build2 (code, type, imag0, imag1));
8885 /* Fold a comparison of the address of COMPONENT_REFs with the same
8886 type and component to a comparison of the address of the base
8887 object. In short, &x->a OP &y->a to x OP y and
8888 &x->a OP &y.a to x OP &y */
8889 if (TREE_CODE (arg0) == ADDR_EXPR
8890 && TREE_CODE (TREE_OPERAND (arg0, 0)) == COMPONENT_REF
8891 && TREE_CODE (arg1) == ADDR_EXPR
8892 && TREE_CODE (TREE_OPERAND (arg1, 0)) == COMPONENT_REF)
8894 tree cref0 = TREE_OPERAND (arg0, 0);
8895 tree cref1 = TREE_OPERAND (arg1, 0);
8896 if (TREE_OPERAND (cref0, 1) == TREE_OPERAND (cref1, 1))
8898 tree op0 = TREE_OPERAND (cref0, 0);
8899 tree op1 = TREE_OPERAND (cref1, 0);
8900 return fold_build2 (code, type,
8901 build_fold_addr_expr (op0),
8902 build_fold_addr_expr (op1));
8906 /* We can fold X/C1 op C2 where C1 and C2 are integer constants
8907 into a single range test. */
8908 if ((TREE_CODE (arg0) == TRUNC_DIV_EXPR
8909 || TREE_CODE (arg0) == EXACT_DIV_EXPR)
8910 && TREE_CODE (arg1) == INTEGER_CST
8911 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8912 && !integer_zerop (TREE_OPERAND (arg0, 1))
8913 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
8914 && !TREE_OVERFLOW (arg1))
8916 tem = fold_div_compare (code, type, arg0, arg1);
8917 if (tem != NULL_TREE)
8921 /* Fold ~X op ~Y as Y op X. */
8922 if (TREE_CODE (arg0) == BIT_NOT_EXPR
8923 && TREE_CODE (arg1) == BIT_NOT_EXPR)
8925 tree cmp_type = TREE_TYPE (TREE_OPERAND (arg0, 0));
8926 return fold_build2 (code, type,
8927 fold_convert (cmp_type, TREE_OPERAND (arg1, 0)),
8928 TREE_OPERAND (arg0, 0));
8931 /* Fold ~X op C as X op' ~C, where op' is the swapped comparison. */
8932 if (TREE_CODE (arg0) == BIT_NOT_EXPR
8933 && TREE_CODE (arg1) == INTEGER_CST)
8935 tree cmp_type = TREE_TYPE (TREE_OPERAND (arg0, 0));
8936 return fold_build2 (swap_tree_comparison (code), type,
8937 TREE_OPERAND (arg0, 0),
8938 fold_build1 (BIT_NOT_EXPR, cmp_type,
8939 fold_convert (cmp_type, arg1)));
8946 /* Subroutine of fold_binary. Optimize complex multiplications of the
8947 form z * conj(z), as pow(realpart(z),2) + pow(imagpart(z),2). The
8948 argument EXPR represents the expression "z" of type TYPE. */
8951 fold_mult_zconjz (tree type, tree expr)
8953 tree itype = TREE_TYPE (type);
8954 tree rpart, ipart, tem;
8956 if (TREE_CODE (expr) == COMPLEX_EXPR)
8958 rpart = TREE_OPERAND (expr, 0);
8959 ipart = TREE_OPERAND (expr, 1);
8961 else if (TREE_CODE (expr) == COMPLEX_CST)
8963 rpart = TREE_REALPART (expr);
8964 ipart = TREE_IMAGPART (expr);
8968 expr = save_expr (expr);
8969 rpart = fold_build1 (REALPART_EXPR, itype, expr);
8970 ipart = fold_build1 (IMAGPART_EXPR, itype, expr);
8973 rpart = save_expr (rpart);
8974 ipart = save_expr (ipart);
8975 tem = fold_build2 (PLUS_EXPR, itype,
8976 fold_build2 (MULT_EXPR, itype, rpart, rpart),
8977 fold_build2 (MULT_EXPR, itype, ipart, ipart));
8978 return fold_build2 (COMPLEX_EXPR, type, tem,
8979 fold_convert (itype, integer_zero_node));
8983 /* Fold a binary expression of code CODE and type TYPE with operands
8984 OP0 and OP1. Return the folded expression if folding is
8985 successful. Otherwise, return NULL_TREE. */
8988 fold_binary (enum tree_code code, tree type, tree op0, tree op1)
8990 enum tree_code_class kind = TREE_CODE_CLASS (code);
8991 tree arg0, arg1, tem;
8992 tree t1 = NULL_TREE;
8993 bool strict_overflow_p;
8995 gcc_assert ((IS_EXPR_CODE_CLASS (kind)
8996 || IS_GIMPLE_STMT_CODE_CLASS (kind))
8997 && TREE_CODE_LENGTH (code) == 2
8999 && op1 != NULL_TREE);
9004 /* Strip any conversions that don't change the mode. This is
9005 safe for every expression, except for a comparison expression
9006 because its signedness is derived from its operands. So, in
9007 the latter case, only strip conversions that don't change the
9010 Note that this is done as an internal manipulation within the
9011 constant folder, in order to find the simplest representation
9012 of the arguments so that their form can be studied. In any
9013 cases, the appropriate type conversions should be put back in
9014 the tree that will get out of the constant folder. */
9016 if (kind == tcc_comparison)
9018 STRIP_SIGN_NOPS (arg0);
9019 STRIP_SIGN_NOPS (arg1);
9027 /* Note that TREE_CONSTANT isn't enough: static var addresses are
9028 constant but we can't do arithmetic on them. */
9029 if ((TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
9030 || (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
9031 || (TREE_CODE (arg0) == COMPLEX_CST && TREE_CODE (arg1) == COMPLEX_CST)
9032 || (TREE_CODE (arg0) == VECTOR_CST && TREE_CODE (arg1) == VECTOR_CST))
9034 if (kind == tcc_binary)
9035 tem = const_binop (code, arg0, arg1, 0);
9036 else if (kind == tcc_comparison)
9037 tem = fold_relational_const (code, type, arg0, arg1);
9041 if (tem != NULL_TREE)
9043 if (TREE_TYPE (tem) != type)
9044 tem = fold_convert (type, tem);
9049 /* If this is a commutative operation, and ARG0 is a constant, move it
9050 to ARG1 to reduce the number of tests below. */
9051 if (commutative_tree_code (code)
9052 && tree_swap_operands_p (arg0, arg1, true))
9053 return fold_build2 (code, type, op1, op0);
9055 /* ARG0 is the first operand of EXPR, and ARG1 is the second operand.
9057 First check for cases where an arithmetic operation is applied to a
9058 compound, conditional, or comparison operation. Push the arithmetic
9059 operation inside the compound or conditional to see if any folding
9060 can then be done. Convert comparison to conditional for this purpose.
9061 The also optimizes non-constant cases that used to be done in
9064 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
9065 one of the operands is a comparison and the other is a comparison, a
9066 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
9067 code below would make the expression more complex. Change it to a
9068 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
9069 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
9071 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
9072 || code == EQ_EXPR || code == NE_EXPR)
9073 && ((truth_value_p (TREE_CODE (arg0))
9074 && (truth_value_p (TREE_CODE (arg1))
9075 || (TREE_CODE (arg1) == BIT_AND_EXPR
9076 && integer_onep (TREE_OPERAND (arg1, 1)))))
9077 || (truth_value_p (TREE_CODE (arg1))
9078 && (truth_value_p (TREE_CODE (arg0))
9079 || (TREE_CODE (arg0) == BIT_AND_EXPR
9080 && integer_onep (TREE_OPERAND (arg0, 1)))))))
9082 tem = fold_build2 (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
9083 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
9086 fold_convert (boolean_type_node, arg0),
9087 fold_convert (boolean_type_node, arg1));
9089 if (code == EQ_EXPR)
9090 tem = invert_truthvalue (tem);
9092 return fold_convert (type, tem);
9095 if (TREE_CODE_CLASS (code) == tcc_binary
9096 || TREE_CODE_CLASS (code) == tcc_comparison)
9098 if (TREE_CODE (arg0) == COMPOUND_EXPR)
9099 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
9100 fold_build2 (code, type,
9101 TREE_OPERAND (arg0, 1), op1));
9102 if (TREE_CODE (arg1) == COMPOUND_EXPR
9103 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
9104 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
9105 fold_build2 (code, type,
9106 op0, TREE_OPERAND (arg1, 1)));
9108 if (TREE_CODE (arg0) == COND_EXPR || COMPARISON_CLASS_P (arg0))
9110 tem = fold_binary_op_with_conditional_arg (code, type, op0, op1,
9112 /*cond_first_p=*/1);
9113 if (tem != NULL_TREE)
9117 if (TREE_CODE (arg1) == COND_EXPR || COMPARISON_CLASS_P (arg1))
9119 tem = fold_binary_op_with_conditional_arg (code, type, op0, op1,
9121 /*cond_first_p=*/0);
9122 if (tem != NULL_TREE)
9130 /* A + (-B) -> A - B */
9131 if (TREE_CODE (arg1) == NEGATE_EXPR)
9132 return fold_build2 (MINUS_EXPR, type,
9133 fold_convert (type, arg0),
9134 fold_convert (type, TREE_OPERAND (arg1, 0)));
9135 /* (-A) + B -> B - A */
9136 if (TREE_CODE (arg0) == NEGATE_EXPR
9137 && reorder_operands_p (TREE_OPERAND (arg0, 0), arg1))
9138 return fold_build2 (MINUS_EXPR, type,
9139 fold_convert (type, arg1),
9140 fold_convert (type, TREE_OPERAND (arg0, 0)));
9141 /* Convert ~A + 1 to -A. */
9142 if (INTEGRAL_TYPE_P (type)
9143 && TREE_CODE (arg0) == BIT_NOT_EXPR
9144 && integer_onep (arg1))
9145 return fold_build1 (NEGATE_EXPR, type, TREE_OPERAND (arg0, 0));
9147 /* Handle (A1 * C1) + (A2 * C2) with A1, A2 or C1, C2 being the
9149 if ((TREE_CODE (arg0) == MULT_EXPR
9150 || TREE_CODE (arg1) == MULT_EXPR)
9151 && (!FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
9153 tree tem = fold_plusminus_mult_expr (code, type, arg0, arg1);
9158 if (! FLOAT_TYPE_P (type))
9160 if (integer_zerop (arg1))
9161 return non_lvalue (fold_convert (type, arg0));
9164 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9165 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
9166 && !TYPE_OVERFLOW_TRAPS (type))
9168 t1 = build_int_cst_type (type, -1);
9169 return omit_one_operand (type, t1, arg1);
9173 if (TREE_CODE (arg1) == BIT_NOT_EXPR
9174 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)
9175 && !TYPE_OVERFLOW_TRAPS (type))
9177 t1 = build_int_cst_type (type, -1);
9178 return omit_one_operand (type, t1, arg0);
9181 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
9182 with a constant, and the two constants have no bits in common,
9183 we should treat this as a BIT_IOR_EXPR since this may produce more
9185 if (TREE_CODE (arg0) == BIT_AND_EXPR
9186 && TREE_CODE (arg1) == BIT_AND_EXPR
9187 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
9188 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
9189 && integer_zerop (const_binop (BIT_AND_EXPR,
9190 TREE_OPERAND (arg0, 1),
9191 TREE_OPERAND (arg1, 1), 0)))
9193 code = BIT_IOR_EXPR;
9197 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
9198 (plus (plus (mult) (mult)) (foo)) so that we can
9199 take advantage of the factoring cases below. */
9200 if (((TREE_CODE (arg0) == PLUS_EXPR
9201 || TREE_CODE (arg0) == MINUS_EXPR)
9202 && TREE_CODE (arg1) == MULT_EXPR)
9203 || ((TREE_CODE (arg1) == PLUS_EXPR
9204 || TREE_CODE (arg1) == MINUS_EXPR)
9205 && TREE_CODE (arg0) == MULT_EXPR))
9207 tree parg0, parg1, parg, marg;
9208 enum tree_code pcode;
9210 if (TREE_CODE (arg1) == MULT_EXPR)
9211 parg = arg0, marg = arg1;
9213 parg = arg1, marg = arg0;
9214 pcode = TREE_CODE (parg);
9215 parg0 = TREE_OPERAND (parg, 0);
9216 parg1 = TREE_OPERAND (parg, 1);
9220 if (TREE_CODE (parg0) == MULT_EXPR
9221 && TREE_CODE (parg1) != MULT_EXPR)
9222 return fold_build2 (pcode, type,
9223 fold_build2 (PLUS_EXPR, type,
9224 fold_convert (type, parg0),
9225 fold_convert (type, marg)),
9226 fold_convert (type, parg1));
9227 if (TREE_CODE (parg0) != MULT_EXPR
9228 && TREE_CODE (parg1) == MULT_EXPR)
9229 return fold_build2 (PLUS_EXPR, type,
9230 fold_convert (type, parg0),
9231 fold_build2 (pcode, type,
9232 fold_convert (type, marg),
9237 /* Try replacing &a[i1] + c * i2 with &a[i1 + i2], if c is step
9238 of the array. Loop optimizer sometimes produce this type of
9240 if (TREE_CODE (arg0) == ADDR_EXPR)
9242 tem = try_move_mult_to_index (PLUS_EXPR, arg0, arg1);
9244 return fold_convert (type, tem);
9246 else if (TREE_CODE (arg1) == ADDR_EXPR)
9248 tem = try_move_mult_to_index (PLUS_EXPR, arg1, arg0);
9250 return fold_convert (type, tem);
9255 /* See if ARG1 is zero and X + ARG1 reduces to X. */
9256 if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
9257 return non_lvalue (fold_convert (type, arg0));
9259 /* Likewise if the operands are reversed. */
9260 if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
9261 return non_lvalue (fold_convert (type, arg1));
9263 /* Convert X + -C into X - C. */
9264 if (TREE_CODE (arg1) == REAL_CST
9265 && REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1)))
9267 tem = fold_negate_const (arg1, type);
9268 if (!TREE_OVERFLOW (arg1) || !flag_trapping_math)
9269 return fold_build2 (MINUS_EXPR, type,
9270 fold_convert (type, arg0),
9271 fold_convert (type, tem));
9274 /* Fold __complex__ ( x, 0 ) + __complex__ ( 0, y )
9275 to __complex__ ( x, y ). This is not the same for SNaNs or
9276 if signed zeros are involved. */
9277 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
9278 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
9279 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0)))
9281 tree rtype = TREE_TYPE (TREE_TYPE (arg0));
9282 tree arg0r = fold_unary (REALPART_EXPR, rtype, arg0);
9283 tree arg0i = fold_unary (IMAGPART_EXPR, rtype, arg0);
9284 bool arg0rz = false, arg0iz = false;
9285 if ((arg0r && (arg0rz = real_zerop (arg0r)))
9286 || (arg0i && (arg0iz = real_zerop (arg0i))))
9288 tree arg1r = fold_unary (REALPART_EXPR, rtype, arg1);
9289 tree arg1i = fold_unary (IMAGPART_EXPR, rtype, arg1);
9290 if (arg0rz && arg1i && real_zerop (arg1i))
9292 tree rp = arg1r ? arg1r
9293 : build1 (REALPART_EXPR, rtype, arg1);
9294 tree ip = arg0i ? arg0i
9295 : build1 (IMAGPART_EXPR, rtype, arg0);
9296 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
9298 else if (arg0iz && arg1r && real_zerop (arg1r))
9300 tree rp = arg0r ? arg0r
9301 : build1 (REALPART_EXPR, rtype, arg0);
9302 tree ip = arg1i ? arg1i
9303 : build1 (IMAGPART_EXPR, rtype, arg1);
9304 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
9309 if (flag_unsafe_math_optimizations
9310 && (TREE_CODE (arg0) == RDIV_EXPR || TREE_CODE (arg0) == MULT_EXPR)
9311 && (TREE_CODE (arg1) == RDIV_EXPR || TREE_CODE (arg1) == MULT_EXPR)
9312 && (tem = distribute_real_division (code, type, arg0, arg1)))
9315 /* Convert x+x into x*2.0. */
9316 if (operand_equal_p (arg0, arg1, 0)
9317 && SCALAR_FLOAT_TYPE_P (type))
9318 return fold_build2 (MULT_EXPR, type, arg0,
9319 build_real (type, dconst2));
9321 /* Convert a + (b*c + d*e) into (a + b*c) + d*e. */
9322 if (flag_unsafe_math_optimizations
9323 && TREE_CODE (arg1) == PLUS_EXPR
9324 && TREE_CODE (arg0) != MULT_EXPR)
9326 tree tree10 = TREE_OPERAND (arg1, 0);
9327 tree tree11 = TREE_OPERAND (arg1, 1);
9328 if (TREE_CODE (tree11) == MULT_EXPR
9329 && TREE_CODE (tree10) == MULT_EXPR)
9332 tree0 = fold_build2 (PLUS_EXPR, type, arg0, tree10);
9333 return fold_build2 (PLUS_EXPR, type, tree0, tree11);
9336 /* Convert (b*c + d*e) + a into b*c + (d*e +a). */
9337 if (flag_unsafe_math_optimizations
9338 && TREE_CODE (arg0) == PLUS_EXPR
9339 && TREE_CODE (arg1) != MULT_EXPR)
9341 tree tree00 = TREE_OPERAND (arg0, 0);
9342 tree tree01 = TREE_OPERAND (arg0, 1);
9343 if (TREE_CODE (tree01) == MULT_EXPR
9344 && TREE_CODE (tree00) == MULT_EXPR)
9347 tree0 = fold_build2 (PLUS_EXPR, type, tree01, arg1);
9348 return fold_build2 (PLUS_EXPR, type, tree00, tree0);
9354 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
9355 is a rotate of A by C1 bits. */
9356 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
9357 is a rotate of A by B bits. */
9359 enum tree_code code0, code1;
9360 code0 = TREE_CODE (arg0);
9361 code1 = TREE_CODE (arg1);
9362 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
9363 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
9364 && operand_equal_p (TREE_OPERAND (arg0, 0),
9365 TREE_OPERAND (arg1, 0), 0)
9366 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
9368 tree tree01, tree11;
9369 enum tree_code code01, code11;
9371 tree01 = TREE_OPERAND (arg0, 1);
9372 tree11 = TREE_OPERAND (arg1, 1);
9373 STRIP_NOPS (tree01);
9374 STRIP_NOPS (tree11);
9375 code01 = TREE_CODE (tree01);
9376 code11 = TREE_CODE (tree11);
9377 if (code01 == INTEGER_CST
9378 && code11 == INTEGER_CST
9379 && TREE_INT_CST_HIGH (tree01) == 0
9380 && TREE_INT_CST_HIGH (tree11) == 0
9381 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
9382 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
9383 return build2 (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
9384 code0 == LSHIFT_EXPR ? tree01 : tree11);
9385 else if (code11 == MINUS_EXPR)
9387 tree tree110, tree111;
9388 tree110 = TREE_OPERAND (tree11, 0);
9389 tree111 = TREE_OPERAND (tree11, 1);
9390 STRIP_NOPS (tree110);
9391 STRIP_NOPS (tree111);
9392 if (TREE_CODE (tree110) == INTEGER_CST
9393 && 0 == compare_tree_int (tree110,
9395 (TREE_TYPE (TREE_OPERAND
9397 && operand_equal_p (tree01, tree111, 0))
9398 return build2 ((code0 == LSHIFT_EXPR
9401 type, TREE_OPERAND (arg0, 0), tree01);
9403 else if (code01 == MINUS_EXPR)
9405 tree tree010, tree011;
9406 tree010 = TREE_OPERAND (tree01, 0);
9407 tree011 = TREE_OPERAND (tree01, 1);
9408 STRIP_NOPS (tree010);
9409 STRIP_NOPS (tree011);
9410 if (TREE_CODE (tree010) == INTEGER_CST
9411 && 0 == compare_tree_int (tree010,
9413 (TREE_TYPE (TREE_OPERAND
9415 && operand_equal_p (tree11, tree011, 0))
9416 return build2 ((code0 != LSHIFT_EXPR
9419 type, TREE_OPERAND (arg0, 0), tree11);
9425 /* In most languages, can't associate operations on floats through
9426 parentheses. Rather than remember where the parentheses were, we
9427 don't associate floats at all, unless the user has specified
9428 -funsafe-math-optimizations. */
9430 if (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
9432 tree var0, con0, lit0, minus_lit0;
9433 tree var1, con1, lit1, minus_lit1;
9436 /* Split both trees into variables, constants, and literals. Then
9437 associate each group together, the constants with literals,
9438 then the result with variables. This increases the chances of
9439 literals being recombined later and of generating relocatable
9440 expressions for the sum of a constant and literal. */
9441 var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
9442 var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
9443 code == MINUS_EXPR);
9445 /* With undefined overflow we can only associate constants
9446 with one variable. */
9447 if ((POINTER_TYPE_P (type)
9448 || (INTEGRAL_TYPE_P (type) && !TYPE_OVERFLOW_WRAPS (type)))
9454 if (TREE_CODE (tmp0) == NEGATE_EXPR)
9455 tmp0 = TREE_OPERAND (tmp0, 0);
9456 if (TREE_CODE (tmp1) == NEGATE_EXPR)
9457 tmp1 = TREE_OPERAND (tmp1, 0);
9458 /* The only case we can still associate with two variables
9459 is if they are the same, modulo negation. */
9460 if (!operand_equal_p (tmp0, tmp1, 0))
9464 /* Only do something if we found more than two objects. Otherwise,
9465 nothing has changed and we risk infinite recursion. */
9467 && (2 < ((var0 != 0) + (var1 != 0)
9468 + (con0 != 0) + (con1 != 0)
9469 + (lit0 != 0) + (lit1 != 0)
9470 + (minus_lit0 != 0) + (minus_lit1 != 0))))
9472 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
9473 if (code == MINUS_EXPR)
9476 var0 = associate_trees (var0, var1, code, type);
9477 con0 = associate_trees (con0, con1, code, type);
9478 lit0 = associate_trees (lit0, lit1, code, type);
9479 minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
9481 /* Preserve the MINUS_EXPR if the negative part of the literal is
9482 greater than the positive part. Otherwise, the multiplicative
9483 folding code (i.e extract_muldiv) may be fooled in case
9484 unsigned constants are subtracted, like in the following
9485 example: ((X*2 + 4) - 8U)/2. */
9486 if (minus_lit0 && lit0)
9488 if (TREE_CODE (lit0) == INTEGER_CST
9489 && TREE_CODE (minus_lit0) == INTEGER_CST
9490 && tree_int_cst_lt (lit0, minus_lit0))
9492 minus_lit0 = associate_trees (minus_lit0, lit0,
9498 lit0 = associate_trees (lit0, minus_lit0,
9506 return fold_convert (type,
9507 associate_trees (var0, minus_lit0,
9511 con0 = associate_trees (con0, minus_lit0,
9513 return fold_convert (type,
9514 associate_trees (var0, con0,
9519 con0 = associate_trees (con0, lit0, code, type);
9520 return fold_convert (type, associate_trees (var0, con0,
9528 /* A - (-B) -> A + B */
9529 if (TREE_CODE (arg1) == NEGATE_EXPR)
9530 return fold_build2 (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0));
9531 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
9532 if (TREE_CODE (arg0) == NEGATE_EXPR
9533 && (FLOAT_TYPE_P (type)
9534 || INTEGRAL_TYPE_P (type))
9535 && negate_expr_p (arg1)
9536 && reorder_operands_p (arg0, arg1))
9537 return fold_build2 (MINUS_EXPR, type, negate_expr (arg1),
9538 TREE_OPERAND (arg0, 0));
9539 /* Convert -A - 1 to ~A. */
9540 if (INTEGRAL_TYPE_P (type)
9541 && TREE_CODE (arg0) == NEGATE_EXPR
9542 && integer_onep (arg1)
9543 && !TYPE_OVERFLOW_TRAPS (type))
9544 return fold_build1 (BIT_NOT_EXPR, type,
9545 fold_convert (type, TREE_OPERAND (arg0, 0)));
9547 /* Convert -1 - A to ~A. */
9548 if (INTEGRAL_TYPE_P (type)
9549 && integer_all_onesp (arg0))
9550 return fold_build1 (BIT_NOT_EXPR, type, op1);
9552 if (! FLOAT_TYPE_P (type))
9554 if (integer_zerop (arg0))
9555 return negate_expr (fold_convert (type, arg1));
9556 if (integer_zerop (arg1))
9557 return non_lvalue (fold_convert (type, arg0));
9559 /* Fold A - (A & B) into ~B & A. */
9560 if (!TREE_SIDE_EFFECTS (arg0)
9561 && TREE_CODE (arg1) == BIT_AND_EXPR)
9563 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
9564 return fold_build2 (BIT_AND_EXPR, type,
9565 fold_build1 (BIT_NOT_EXPR, type,
9566 TREE_OPERAND (arg1, 0)),
9568 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
9569 return fold_build2 (BIT_AND_EXPR, type,
9570 fold_build1 (BIT_NOT_EXPR, type,
9571 TREE_OPERAND (arg1, 1)),
9575 /* Fold (A & ~B) - (A & B) into (A ^ B) - B, where B is
9576 any power of 2 minus 1. */
9577 if (TREE_CODE (arg0) == BIT_AND_EXPR
9578 && TREE_CODE (arg1) == BIT_AND_EXPR
9579 && operand_equal_p (TREE_OPERAND (arg0, 0),
9580 TREE_OPERAND (arg1, 0), 0))
9582 tree mask0 = TREE_OPERAND (arg0, 1);
9583 tree mask1 = TREE_OPERAND (arg1, 1);
9584 tree tem = fold_build1 (BIT_NOT_EXPR, type, mask0);
9586 if (operand_equal_p (tem, mask1, 0))
9588 tem = fold_build2 (BIT_XOR_EXPR, type,
9589 TREE_OPERAND (arg0, 0), mask1);
9590 return fold_build2 (MINUS_EXPR, type, tem, mask1);
9595 /* See if ARG1 is zero and X - ARG1 reduces to X. */
9596 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
9597 return non_lvalue (fold_convert (type, arg0));
9599 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
9600 ARG0 is zero and X + ARG0 reduces to X, since that would mean
9601 (-ARG1 + ARG0) reduces to -ARG1. */
9602 else if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
9603 return negate_expr (fold_convert (type, arg1));
9605 /* Fold __complex__ ( x, 0 ) - __complex__ ( 0, y ) to
9606 __complex__ ( x, -y ). This is not the same for SNaNs or if
9607 signed zeros are involved. */
9608 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
9609 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
9610 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0)))
9612 tree rtype = TREE_TYPE (TREE_TYPE (arg0));
9613 tree arg0r = fold_unary (REALPART_EXPR, rtype, arg0);
9614 tree arg0i = fold_unary (IMAGPART_EXPR, rtype, arg0);
9615 bool arg0rz = false, arg0iz = false;
9616 if ((arg0r && (arg0rz = real_zerop (arg0r)))
9617 || (arg0i && (arg0iz = real_zerop (arg0i))))
9619 tree arg1r = fold_unary (REALPART_EXPR, rtype, arg1);
9620 tree arg1i = fold_unary (IMAGPART_EXPR, rtype, arg1);
9621 if (arg0rz && arg1i && real_zerop (arg1i))
9623 tree rp = fold_build1 (NEGATE_EXPR, rtype,
9625 : build1 (REALPART_EXPR, rtype, arg1));
9626 tree ip = arg0i ? arg0i
9627 : build1 (IMAGPART_EXPR, rtype, arg0);
9628 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
9630 else if (arg0iz && arg1r && real_zerop (arg1r))
9632 tree rp = arg0r ? arg0r
9633 : build1 (REALPART_EXPR, rtype, arg0);
9634 tree ip = fold_build1 (NEGATE_EXPR, rtype,
9636 : build1 (IMAGPART_EXPR, rtype, arg1));
9637 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
9642 /* Fold &x - &x. This can happen from &x.foo - &x.
9643 This is unsafe for certain floats even in non-IEEE formats.
9644 In IEEE, it is unsafe because it does wrong for NaNs.
9645 Also note that operand_equal_p is always false if an operand
9648 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
9649 && operand_equal_p (arg0, arg1, 0))
9650 return fold_convert (type, integer_zero_node);
9652 /* A - B -> A + (-B) if B is easily negatable. */
9653 if (negate_expr_p (arg1)
9654 && ((FLOAT_TYPE_P (type)
9655 /* Avoid this transformation if B is a positive REAL_CST. */
9656 && (TREE_CODE (arg1) != REAL_CST
9657 || REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1))))
9658 || INTEGRAL_TYPE_P (type)))
9659 return fold_build2 (PLUS_EXPR, type,
9660 fold_convert (type, arg0),
9661 fold_convert (type, negate_expr (arg1)));
9663 /* Try folding difference of addresses. */
9667 if ((TREE_CODE (arg0) == ADDR_EXPR
9668 || TREE_CODE (arg1) == ADDR_EXPR)
9669 && ptr_difference_const (arg0, arg1, &diff))
9670 return build_int_cst_type (type, diff);
9673 /* Fold &a[i] - &a[j] to i-j. */
9674 if (TREE_CODE (arg0) == ADDR_EXPR
9675 && TREE_CODE (TREE_OPERAND (arg0, 0)) == ARRAY_REF
9676 && TREE_CODE (arg1) == ADDR_EXPR
9677 && TREE_CODE (TREE_OPERAND (arg1, 0)) == ARRAY_REF)
9679 tree aref0 = TREE_OPERAND (arg0, 0);
9680 tree aref1 = TREE_OPERAND (arg1, 0);
9681 if (operand_equal_p (TREE_OPERAND (aref0, 0),
9682 TREE_OPERAND (aref1, 0), 0))
9684 tree op0 = fold_convert (type, TREE_OPERAND (aref0, 1));
9685 tree op1 = fold_convert (type, TREE_OPERAND (aref1, 1));
9686 tree esz = array_ref_element_size (aref0);
9687 tree diff = build2 (MINUS_EXPR, type, op0, op1);
9688 return fold_build2 (MULT_EXPR, type, diff,
9689 fold_convert (type, esz));
9694 /* Try replacing &a[i1] - c * i2 with &a[i1 - i2], if c is step
9695 of the array. Loop optimizer sometimes produce this type of
9697 if (TREE_CODE (arg0) == ADDR_EXPR)
9699 tem = try_move_mult_to_index (MINUS_EXPR, arg0, arg1);
9701 return fold_convert (type, tem);
9704 if (flag_unsafe_math_optimizations
9705 && (TREE_CODE (arg0) == RDIV_EXPR || TREE_CODE (arg0) == MULT_EXPR)
9706 && (TREE_CODE (arg1) == RDIV_EXPR || TREE_CODE (arg1) == MULT_EXPR)
9707 && (tem = distribute_real_division (code, type, arg0, arg1)))
9710 /* Handle (A1 * C1) - (A2 * C2) with A1, A2 or C1, C2 being the
9712 if ((TREE_CODE (arg0) == MULT_EXPR
9713 || TREE_CODE (arg1) == MULT_EXPR)
9714 && (!FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
9716 tree tem = fold_plusminus_mult_expr (code, type, arg0, arg1);
9724 /* (-A) * (-B) -> A * B */
9725 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
9726 return fold_build2 (MULT_EXPR, type,
9727 fold_convert (type, TREE_OPERAND (arg0, 0)),
9728 fold_convert (type, negate_expr (arg1)));
9729 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
9730 return fold_build2 (MULT_EXPR, type,
9731 fold_convert (type, negate_expr (arg0)),
9732 fold_convert (type, TREE_OPERAND (arg1, 0)));
9734 if (! FLOAT_TYPE_P (type))
9736 if (integer_zerop (arg1))
9737 return omit_one_operand (type, arg1, arg0);
9738 if (integer_onep (arg1))
9739 return non_lvalue (fold_convert (type, arg0));
9740 /* Transform x * -1 into -x. */
9741 if (integer_all_onesp (arg1))
9742 return fold_convert (type, negate_expr (arg0));
9743 /* Transform x * -C into -x * C if x is easily negatable. */
9744 if (TREE_CODE (arg1) == INTEGER_CST
9745 && tree_int_cst_sgn (arg1) == -1
9746 && negate_expr_p (arg0)
9747 && (tem = negate_expr (arg1)) != arg1
9748 && !TREE_OVERFLOW (tem))
9749 return fold_build2 (MULT_EXPR, type,
9750 negate_expr (arg0), tem);
9752 /* (a * (1 << b)) is (a << b) */
9753 if (TREE_CODE (arg1) == LSHIFT_EXPR
9754 && integer_onep (TREE_OPERAND (arg1, 0)))
9755 return fold_build2 (LSHIFT_EXPR, type, arg0,
9756 TREE_OPERAND (arg1, 1));
9757 if (TREE_CODE (arg0) == LSHIFT_EXPR
9758 && integer_onep (TREE_OPERAND (arg0, 0)))
9759 return fold_build2 (LSHIFT_EXPR, type, arg1,
9760 TREE_OPERAND (arg0, 1));
9762 strict_overflow_p = false;
9763 if (TREE_CODE (arg1) == INTEGER_CST
9764 && 0 != (tem = extract_muldiv (op0,
9765 fold_convert (type, arg1),
9767 &strict_overflow_p)))
9769 if (strict_overflow_p)
9770 fold_overflow_warning (("assuming signed overflow does not "
9771 "occur when simplifying "
9773 WARN_STRICT_OVERFLOW_MISC);
9774 return fold_convert (type, tem);
9777 /* Optimize z * conj(z) for integer complex numbers. */
9778 if (TREE_CODE (arg0) == CONJ_EXPR
9779 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
9780 return fold_mult_zconjz (type, arg1);
9781 if (TREE_CODE (arg1) == CONJ_EXPR
9782 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
9783 return fold_mult_zconjz (type, arg0);
9787 /* Maybe fold x * 0 to 0. The expressions aren't the same
9788 when x is NaN, since x * 0 is also NaN. Nor are they the
9789 same in modes with signed zeros, since multiplying a
9790 negative value by 0 gives -0, not +0. */
9791 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
9792 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
9793 && real_zerop (arg1))
9794 return omit_one_operand (type, arg1, arg0);
9795 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
9796 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
9797 && real_onep (arg1))
9798 return non_lvalue (fold_convert (type, arg0));
9800 /* Transform x * -1.0 into -x. */
9801 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
9802 && real_minus_onep (arg1))
9803 return fold_convert (type, negate_expr (arg0));
9805 /* Convert (C1/X)*C2 into (C1*C2)/X. */
9806 if (flag_unsafe_math_optimizations
9807 && TREE_CODE (arg0) == RDIV_EXPR
9808 && TREE_CODE (arg1) == REAL_CST
9809 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST)
9811 tree tem = const_binop (MULT_EXPR, TREE_OPERAND (arg0, 0),
9814 return fold_build2 (RDIV_EXPR, type, tem,
9815 TREE_OPERAND (arg0, 1));
9818 /* Strip sign operations from X in X*X, i.e. -Y*-Y -> Y*Y. */
9819 if (operand_equal_p (arg0, arg1, 0))
9821 tree tem = fold_strip_sign_ops (arg0);
9822 if (tem != NULL_TREE)
9824 tem = fold_convert (type, tem);
9825 return fold_build2 (MULT_EXPR, type, tem, tem);
9829 /* Fold z * +-I to __complex__ (-+__imag z, +-__real z).
9830 This is not the same for NaNs or if signed zeros are
9832 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
9833 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
9834 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0))
9835 && TREE_CODE (arg1) == COMPLEX_CST
9836 && real_zerop (TREE_REALPART (arg1)))
9838 tree rtype = TREE_TYPE (TREE_TYPE (arg0));
9839 if (real_onep (TREE_IMAGPART (arg1)))
9840 return fold_build2 (COMPLEX_EXPR, type,
9841 negate_expr (fold_build1 (IMAGPART_EXPR,
9843 fold_build1 (REALPART_EXPR, rtype, arg0));
9844 else if (real_minus_onep (TREE_IMAGPART (arg1)))
9845 return fold_build2 (COMPLEX_EXPR, type,
9846 fold_build1 (IMAGPART_EXPR, rtype, arg0),
9847 negate_expr (fold_build1 (REALPART_EXPR,
9851 /* Optimize z * conj(z) for floating point complex numbers.
9852 Guarded by flag_unsafe_math_optimizations as non-finite
9853 imaginary components don't produce scalar results. */
9854 if (flag_unsafe_math_optimizations
9855 && TREE_CODE (arg0) == CONJ_EXPR
9856 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
9857 return fold_mult_zconjz (type, arg1);
9858 if (flag_unsafe_math_optimizations
9859 && TREE_CODE (arg1) == CONJ_EXPR
9860 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
9861 return fold_mult_zconjz (type, arg0);
9863 if (flag_unsafe_math_optimizations)
9865 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
9866 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
9868 /* Optimizations of root(...)*root(...). */
9869 if (fcode0 == fcode1 && BUILTIN_ROOT_P (fcode0))
9872 tree arg00 = CALL_EXPR_ARG (arg0, 0);
9873 tree arg10 = CALL_EXPR_ARG (arg1, 0);
9875 /* Optimize sqrt(x)*sqrt(x) as x. */
9876 if (BUILTIN_SQRT_P (fcode0)
9877 && operand_equal_p (arg00, arg10, 0)
9878 && ! HONOR_SNANS (TYPE_MODE (type)))
9881 /* Optimize root(x)*root(y) as root(x*y). */
9882 rootfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
9883 arg = fold_build2 (MULT_EXPR, type, arg00, arg10);
9884 return build_call_expr (rootfn, 1, arg);
9887 /* Optimize expN(x)*expN(y) as expN(x+y). */
9888 if (fcode0 == fcode1 && BUILTIN_EXPONENT_P (fcode0))
9890 tree expfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
9891 tree arg = fold_build2 (PLUS_EXPR, type,
9892 CALL_EXPR_ARG (arg0, 0),
9893 CALL_EXPR_ARG (arg1, 0));
9894 return build_call_expr (expfn, 1, arg);
9897 /* Optimizations of pow(...)*pow(...). */
9898 if ((fcode0 == BUILT_IN_POW && fcode1 == BUILT_IN_POW)
9899 || (fcode0 == BUILT_IN_POWF && fcode1 == BUILT_IN_POWF)
9900 || (fcode0 == BUILT_IN_POWL && fcode1 == BUILT_IN_POWL))
9902 tree arg00 = CALL_EXPR_ARG (arg0, 0);
9903 tree arg01 = CALL_EXPR_ARG (arg0, 1);
9904 tree arg10 = CALL_EXPR_ARG (arg1, 0);
9905 tree arg11 = CALL_EXPR_ARG (arg1, 1);
9907 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
9908 if (operand_equal_p (arg01, arg11, 0))
9910 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
9911 tree arg = fold_build2 (MULT_EXPR, type, arg00, arg10);
9912 return build_call_expr (powfn, 2, arg, arg01);
9915 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
9916 if (operand_equal_p (arg00, arg10, 0))
9918 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
9919 tree arg = fold_build2 (PLUS_EXPR, type, arg01, arg11);
9920 return build_call_expr (powfn, 2, arg00, arg);
9924 /* Optimize tan(x)*cos(x) as sin(x). */
9925 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_COS)
9926 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_COSF)
9927 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_COSL)
9928 || (fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_TAN)
9929 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_TANF)
9930 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_TANL))
9931 && operand_equal_p (CALL_EXPR_ARG (arg0, 0),
9932 CALL_EXPR_ARG (arg1, 0), 0))
9934 tree sinfn = mathfn_built_in (type, BUILT_IN_SIN);
9936 if (sinfn != NULL_TREE)
9937 return build_call_expr (sinfn, 1, CALL_EXPR_ARG (arg0, 0));
9940 /* Optimize x*pow(x,c) as pow(x,c+1). */
9941 if (fcode1 == BUILT_IN_POW
9942 || fcode1 == BUILT_IN_POWF
9943 || fcode1 == BUILT_IN_POWL)
9945 tree arg10 = CALL_EXPR_ARG (arg1, 0);
9946 tree arg11 = CALL_EXPR_ARG (arg1, 1);
9947 if (TREE_CODE (arg11) == REAL_CST
9948 && !TREE_OVERFLOW (arg11)
9949 && operand_equal_p (arg0, arg10, 0))
9951 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
9955 c = TREE_REAL_CST (arg11);
9956 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
9957 arg = build_real (type, c);
9958 return build_call_expr (powfn, 2, arg0, arg);
9962 /* Optimize pow(x,c)*x as pow(x,c+1). */
9963 if (fcode0 == BUILT_IN_POW
9964 || fcode0 == BUILT_IN_POWF
9965 || fcode0 == BUILT_IN_POWL)
9967 tree arg00 = CALL_EXPR_ARG (arg0, 0);
9968 tree arg01 = CALL_EXPR_ARG (arg0, 1);
9969 if (TREE_CODE (arg01) == REAL_CST
9970 && !TREE_OVERFLOW (arg01)
9971 && operand_equal_p (arg1, arg00, 0))
9973 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
9977 c = TREE_REAL_CST (arg01);
9978 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
9979 arg = build_real (type, c);
9980 return build_call_expr (powfn, 2, arg1, arg);
9984 /* Optimize x*x as pow(x,2.0), which is expanded as x*x. */
9986 && operand_equal_p (arg0, arg1, 0))
9988 tree powfn = mathfn_built_in (type, BUILT_IN_POW);
9992 tree arg = build_real (type, dconst2);
9993 return build_call_expr (powfn, 2, arg0, arg);
10002 if (integer_all_onesp (arg1))
10003 return omit_one_operand (type, arg1, arg0);
10004 if (integer_zerop (arg1))
10005 return non_lvalue (fold_convert (type, arg0));
10006 if (operand_equal_p (arg0, arg1, 0))
10007 return non_lvalue (fold_convert (type, arg0));
10009 /* ~X | X is -1. */
10010 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10011 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10013 t1 = build_int_cst_type (type, -1);
10014 return omit_one_operand (type, t1, arg1);
10017 /* X | ~X is -1. */
10018 if (TREE_CODE (arg1) == BIT_NOT_EXPR
10019 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10021 t1 = build_int_cst_type (type, -1);
10022 return omit_one_operand (type, t1, arg0);
10025 /* Canonicalize (X & C1) | C2. */
10026 if (TREE_CODE (arg0) == BIT_AND_EXPR
10027 && TREE_CODE (arg1) == INTEGER_CST
10028 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
10030 unsigned HOST_WIDE_INT hi1, lo1, hi2, lo2, mlo, mhi;
10031 int width = TYPE_PRECISION (type);
10032 hi1 = TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1));
10033 lo1 = TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1));
10034 hi2 = TREE_INT_CST_HIGH (arg1);
10035 lo2 = TREE_INT_CST_LOW (arg1);
10037 /* If (C1&C2) == C1, then (X&C1)|C2 becomes (X,C2). */
10038 if ((hi1 & hi2) == hi1 && (lo1 & lo2) == lo1)
10039 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
10041 if (width > HOST_BITS_PER_WIDE_INT)
10043 mhi = (unsigned HOST_WIDE_INT) -1
10044 >> (2 * HOST_BITS_PER_WIDE_INT - width);
10050 mlo = (unsigned HOST_WIDE_INT) -1
10051 >> (HOST_BITS_PER_WIDE_INT - width);
10054 /* If (C1|C2) == ~0 then (X&C1)|C2 becomes X|C2. */
10055 if ((~(hi1 | hi2) & mhi) == 0 && (~(lo1 | lo2) & mlo) == 0)
10056 return fold_build2 (BIT_IOR_EXPR, type,
10057 TREE_OPERAND (arg0, 0), arg1);
10059 /* Minimize the number of bits set in C1, i.e. C1 := C1 & ~C2. */
10062 if ((hi1 & ~hi2) != hi1 || (lo1 & ~lo2) != lo1)
10063 return fold_build2 (BIT_IOR_EXPR, type,
10064 fold_build2 (BIT_AND_EXPR, type,
10065 TREE_OPERAND (arg0, 0),
10066 build_int_cst_wide (type,
10072 /* (X & Y) | Y is (X, Y). */
10073 if (TREE_CODE (arg0) == BIT_AND_EXPR
10074 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10075 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
10076 /* (X & Y) | X is (Y, X). */
10077 if (TREE_CODE (arg0) == BIT_AND_EXPR
10078 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10079 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10080 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 1));
10081 /* X | (X & Y) is (Y, X). */
10082 if (TREE_CODE (arg1) == BIT_AND_EXPR
10083 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)
10084 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 1)))
10085 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 1));
10086 /* X | (Y & X) is (Y, X). */
10087 if (TREE_CODE (arg1) == BIT_AND_EXPR
10088 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10089 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10090 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 0));
10092 t1 = distribute_bit_expr (code, type, arg0, arg1);
10093 if (t1 != NULL_TREE)
10096 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
10098 This results in more efficient code for machines without a NAND
10099 instruction. Combine will canonicalize to the first form
10100 which will allow use of NAND instructions provided by the
10101 backend if they exist. */
10102 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10103 && TREE_CODE (arg1) == BIT_NOT_EXPR)
10105 return fold_build1 (BIT_NOT_EXPR, type,
10106 build2 (BIT_AND_EXPR, type,
10107 TREE_OPERAND (arg0, 0),
10108 TREE_OPERAND (arg1, 0)));
10111 /* See if this can be simplified into a rotate first. If that
10112 is unsuccessful continue in the association code. */
10116 if (integer_zerop (arg1))
10117 return non_lvalue (fold_convert (type, arg0));
10118 if (integer_all_onesp (arg1))
10119 return fold_build1 (BIT_NOT_EXPR, type, arg0);
10120 if (operand_equal_p (arg0, arg1, 0))
10121 return omit_one_operand (type, integer_zero_node, arg0);
10123 /* ~X ^ X is -1. */
10124 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10125 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10127 t1 = build_int_cst_type (type, -1);
10128 return omit_one_operand (type, t1, arg1);
10131 /* X ^ ~X is -1. */
10132 if (TREE_CODE (arg1) == BIT_NOT_EXPR
10133 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10135 t1 = build_int_cst_type (type, -1);
10136 return omit_one_operand (type, t1, arg0);
10139 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
10140 with a constant, and the two constants have no bits in common,
10141 we should treat this as a BIT_IOR_EXPR since this may produce more
10142 simplifications. */
10143 if (TREE_CODE (arg0) == BIT_AND_EXPR
10144 && TREE_CODE (arg1) == BIT_AND_EXPR
10145 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
10146 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
10147 && integer_zerop (const_binop (BIT_AND_EXPR,
10148 TREE_OPERAND (arg0, 1),
10149 TREE_OPERAND (arg1, 1), 0)))
10151 code = BIT_IOR_EXPR;
10155 /* (X | Y) ^ X -> Y & ~ X*/
10156 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10157 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10159 tree t2 = TREE_OPERAND (arg0, 1);
10160 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1),
10162 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
10163 fold_convert (type, t1));
10167 /* (Y | X) ^ X -> Y & ~ X*/
10168 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10169 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10171 tree t2 = TREE_OPERAND (arg0, 0);
10172 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1),
10174 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
10175 fold_convert (type, t1));
10179 /* X ^ (X | Y) -> Y & ~ X*/
10180 if (TREE_CODE (arg1) == BIT_IOR_EXPR
10181 && operand_equal_p (TREE_OPERAND (arg1, 0), arg0, 0))
10183 tree t2 = TREE_OPERAND (arg1, 1);
10184 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg0),
10186 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
10187 fold_convert (type, t1));
10191 /* X ^ (Y | X) -> Y & ~ X*/
10192 if (TREE_CODE (arg1) == BIT_IOR_EXPR
10193 && operand_equal_p (TREE_OPERAND (arg1, 1), arg0, 0))
10195 tree t2 = TREE_OPERAND (arg1, 0);
10196 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg0),
10198 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
10199 fold_convert (type, t1));
10203 /* Convert ~X ^ ~Y to X ^ Y. */
10204 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10205 && TREE_CODE (arg1) == BIT_NOT_EXPR)
10206 return fold_build2 (code, type,
10207 fold_convert (type, TREE_OPERAND (arg0, 0)),
10208 fold_convert (type, TREE_OPERAND (arg1, 0)));
10210 /* Convert ~X ^ C to X ^ ~C. */
10211 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10212 && TREE_CODE (arg1) == INTEGER_CST)
10213 return fold_build2 (code, type,
10214 fold_convert (type, TREE_OPERAND (arg0, 0)),
10215 fold_build1 (BIT_NOT_EXPR, type, arg1));
10217 /* Fold (X & 1) ^ 1 as (X & 1) == 0. */
10218 if (TREE_CODE (arg0) == BIT_AND_EXPR
10219 && integer_onep (TREE_OPERAND (arg0, 1))
10220 && integer_onep (arg1))
10221 return fold_build2 (EQ_EXPR, type, arg0,
10222 build_int_cst (TREE_TYPE (arg0), 0));
10224 /* Fold (X & Y) ^ Y as ~X & Y. */
10225 if (TREE_CODE (arg0) == BIT_AND_EXPR
10226 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10228 tem = fold_convert (type, TREE_OPERAND (arg0, 0));
10229 return fold_build2 (BIT_AND_EXPR, type,
10230 fold_build1 (BIT_NOT_EXPR, type, tem),
10231 fold_convert (type, arg1));
10233 /* Fold (X & Y) ^ X as ~Y & X. */
10234 if (TREE_CODE (arg0) == BIT_AND_EXPR
10235 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10236 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10238 tem = fold_convert (type, TREE_OPERAND (arg0, 1));
10239 return fold_build2 (BIT_AND_EXPR, type,
10240 fold_build1 (BIT_NOT_EXPR, type, tem),
10241 fold_convert (type, arg1));
10243 /* Fold X ^ (X & Y) as X & ~Y. */
10244 if (TREE_CODE (arg1) == BIT_AND_EXPR
10245 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10247 tem = fold_convert (type, TREE_OPERAND (arg1, 1));
10248 return fold_build2 (BIT_AND_EXPR, type,
10249 fold_convert (type, arg0),
10250 fold_build1 (BIT_NOT_EXPR, type, tem));
10252 /* Fold X ^ (Y & X) as ~Y & X. */
10253 if (TREE_CODE (arg1) == BIT_AND_EXPR
10254 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10255 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10257 tem = fold_convert (type, TREE_OPERAND (arg1, 0));
10258 return fold_build2 (BIT_AND_EXPR, type,
10259 fold_build1 (BIT_NOT_EXPR, type, tem),
10260 fold_convert (type, arg0));
10263 /* See if this can be simplified into a rotate first. If that
10264 is unsuccessful continue in the association code. */
10268 if (integer_all_onesp (arg1))
10269 return non_lvalue (fold_convert (type, arg0));
10270 if (integer_zerop (arg1))
10271 return omit_one_operand (type, arg1, arg0);
10272 if (operand_equal_p (arg0, arg1, 0))
10273 return non_lvalue (fold_convert (type, arg0));
10275 /* ~X & X is always zero. */
10276 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10277 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10278 return omit_one_operand (type, integer_zero_node, arg1);
10280 /* X & ~X is always zero. */
10281 if (TREE_CODE (arg1) == BIT_NOT_EXPR
10282 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10283 return omit_one_operand (type, integer_zero_node, arg0);
10285 /* Canonicalize (X | C1) & C2 as (X & C2) | (C1 & C2). */
10286 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10287 && TREE_CODE (arg1) == INTEGER_CST
10288 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
10289 return fold_build2 (BIT_IOR_EXPR, type,
10290 fold_build2 (BIT_AND_EXPR, type,
10291 TREE_OPERAND (arg0, 0), arg1),
10292 fold_build2 (BIT_AND_EXPR, type,
10293 TREE_OPERAND (arg0, 1), arg1));
10295 /* (X | Y) & Y is (X, Y). */
10296 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10297 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10298 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
10299 /* (X | Y) & X is (Y, X). */
10300 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10301 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10302 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10303 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 1));
10304 /* X & (X | Y) is (Y, X). */
10305 if (TREE_CODE (arg1) == BIT_IOR_EXPR
10306 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)
10307 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 1)))
10308 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 1));
10309 /* X & (Y | X) is (Y, X). */
10310 if (TREE_CODE (arg1) == BIT_IOR_EXPR
10311 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10312 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10313 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 0));
10315 /* Fold (X ^ 1) & 1 as (X & 1) == 0. */
10316 if (TREE_CODE (arg0) == BIT_XOR_EXPR
10317 && integer_onep (TREE_OPERAND (arg0, 1))
10318 && integer_onep (arg1))
10320 tem = TREE_OPERAND (arg0, 0);
10321 return fold_build2 (EQ_EXPR, type,
10322 fold_build2 (BIT_AND_EXPR, TREE_TYPE (tem), tem,
10323 build_int_cst (TREE_TYPE (tem), 1)),
10324 build_int_cst (TREE_TYPE (tem), 0));
10326 /* Fold ~X & 1 as (X & 1) == 0. */
10327 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10328 && integer_onep (arg1))
10330 tem = TREE_OPERAND (arg0, 0);
10331 return fold_build2 (EQ_EXPR, type,
10332 fold_build2 (BIT_AND_EXPR, TREE_TYPE (tem), tem,
10333 build_int_cst (TREE_TYPE (tem), 1)),
10334 build_int_cst (TREE_TYPE (tem), 0));
10337 /* Fold (X ^ Y) & Y as ~X & Y. */
10338 if (TREE_CODE (arg0) == BIT_XOR_EXPR
10339 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10341 tem = fold_convert (type, TREE_OPERAND (arg0, 0));
10342 return fold_build2 (BIT_AND_EXPR, type,
10343 fold_build1 (BIT_NOT_EXPR, type, tem),
10344 fold_convert (type, arg1));
10346 /* Fold (X ^ Y) & X as ~Y & X. */
10347 if (TREE_CODE (arg0) == BIT_XOR_EXPR
10348 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10349 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10351 tem = fold_convert (type, TREE_OPERAND (arg0, 1));
10352 return fold_build2 (BIT_AND_EXPR, type,
10353 fold_build1 (BIT_NOT_EXPR, type, tem),
10354 fold_convert (type, arg1));
10356 /* Fold X & (X ^ Y) as X & ~Y. */
10357 if (TREE_CODE (arg1) == BIT_XOR_EXPR
10358 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10360 tem = fold_convert (type, TREE_OPERAND (arg1, 1));
10361 return fold_build2 (BIT_AND_EXPR, type,
10362 fold_convert (type, arg0),
10363 fold_build1 (BIT_NOT_EXPR, type, tem));
10365 /* Fold X & (Y ^ X) as ~Y & X. */
10366 if (TREE_CODE (arg1) == BIT_XOR_EXPR
10367 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10368 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10370 tem = fold_convert (type, TREE_OPERAND (arg1, 0));
10371 return fold_build2 (BIT_AND_EXPR, type,
10372 fold_build1 (BIT_NOT_EXPR, type, tem),
10373 fold_convert (type, arg0));
10376 t1 = distribute_bit_expr (code, type, arg0, arg1);
10377 if (t1 != NULL_TREE)
10379 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
10380 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
10381 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
10384 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
10386 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
10387 && (~TREE_INT_CST_LOW (arg1)
10388 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
10389 return fold_convert (type, TREE_OPERAND (arg0, 0));
10392 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
10394 This results in more efficient code for machines without a NOR
10395 instruction. Combine will canonicalize to the first form
10396 which will allow use of NOR instructions provided by the
10397 backend if they exist. */
10398 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10399 && TREE_CODE (arg1) == BIT_NOT_EXPR)
10401 return fold_build1 (BIT_NOT_EXPR, type,
10402 build2 (BIT_IOR_EXPR, type,
10403 TREE_OPERAND (arg0, 0),
10404 TREE_OPERAND (arg1, 0)));
10410 /* Don't touch a floating-point divide by zero unless the mode
10411 of the constant can represent infinity. */
10412 if (TREE_CODE (arg1) == REAL_CST
10413 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
10414 && real_zerop (arg1))
10417 /* Optimize A / A to 1.0 if we don't care about
10418 NaNs or Infinities. Skip the transformation
10419 for non-real operands. */
10420 if (SCALAR_FLOAT_TYPE_P (TREE_TYPE (arg0))
10421 && ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
10422 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg0)))
10423 && operand_equal_p (arg0, arg1, 0))
10425 tree r = build_real (TREE_TYPE (arg0), dconst1);
10427 return omit_two_operands (type, r, arg0, arg1);
10430 /* The complex version of the above A / A optimization. */
10431 if (COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0))
10432 && operand_equal_p (arg0, arg1, 0))
10434 tree elem_type = TREE_TYPE (TREE_TYPE (arg0));
10435 if (! HONOR_NANS (TYPE_MODE (elem_type))
10436 && ! HONOR_INFINITIES (TYPE_MODE (elem_type)))
10438 tree r = build_real (elem_type, dconst1);
10439 /* omit_two_operands will call fold_convert for us. */
10440 return omit_two_operands (type, r, arg0, arg1);
10444 /* (-A) / (-B) -> A / B */
10445 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
10446 return fold_build2 (RDIV_EXPR, type,
10447 TREE_OPERAND (arg0, 0),
10448 negate_expr (arg1));
10449 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
10450 return fold_build2 (RDIV_EXPR, type,
10451 negate_expr (arg0),
10452 TREE_OPERAND (arg1, 0));
10454 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
10455 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10456 && real_onep (arg1))
10457 return non_lvalue (fold_convert (type, arg0));
10459 /* In IEEE floating point, x/-1 is not equivalent to -x for snans. */
10460 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10461 && real_minus_onep (arg1))
10462 return non_lvalue (fold_convert (type, negate_expr (arg0)));
10464 /* If ARG1 is a constant, we can convert this to a multiply by the
10465 reciprocal. This does not have the same rounding properties,
10466 so only do this if -funsafe-math-optimizations. We can actually
10467 always safely do it if ARG1 is a power of two, but it's hard to
10468 tell if it is or not in a portable manner. */
10469 if (TREE_CODE (arg1) == REAL_CST)
10471 if (flag_unsafe_math_optimizations
10472 && 0 != (tem = const_binop (code, build_real (type, dconst1),
10474 return fold_build2 (MULT_EXPR, type, arg0, tem);
10475 /* Find the reciprocal if optimizing and the result is exact. */
10479 r = TREE_REAL_CST (arg1);
10480 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
10482 tem = build_real (type, r);
10483 return fold_build2 (MULT_EXPR, type,
10484 fold_convert (type, arg0), tem);
10488 /* Convert A/B/C to A/(B*C). */
10489 if (flag_unsafe_math_optimizations
10490 && TREE_CODE (arg0) == RDIV_EXPR)
10491 return fold_build2 (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
10492 fold_build2 (MULT_EXPR, type,
10493 TREE_OPERAND (arg0, 1), arg1));
10495 /* Convert A/(B/C) to (A/B)*C. */
10496 if (flag_unsafe_math_optimizations
10497 && TREE_CODE (arg1) == RDIV_EXPR)
10498 return fold_build2 (MULT_EXPR, type,
10499 fold_build2 (RDIV_EXPR, type, arg0,
10500 TREE_OPERAND (arg1, 0)),
10501 TREE_OPERAND (arg1, 1));
10503 /* Convert C1/(X*C2) into (C1/C2)/X. */
10504 if (flag_unsafe_math_optimizations
10505 && TREE_CODE (arg1) == MULT_EXPR
10506 && TREE_CODE (arg0) == REAL_CST
10507 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
10509 tree tem = const_binop (RDIV_EXPR, arg0,
10510 TREE_OPERAND (arg1, 1), 0);
10512 return fold_build2 (RDIV_EXPR, type, tem,
10513 TREE_OPERAND (arg1, 0));
10516 if (flag_unsafe_math_optimizations)
10518 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
10519 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
10521 /* Optimize sin(x)/cos(x) as tan(x). */
10522 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_COS)
10523 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_COSF)
10524 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_COSL))
10525 && operand_equal_p (CALL_EXPR_ARG (arg0, 0),
10526 CALL_EXPR_ARG (arg1, 0), 0))
10528 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
10530 if (tanfn != NULL_TREE)
10531 return build_call_expr (tanfn, 1, CALL_EXPR_ARG (arg0, 0));
10534 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
10535 if (((fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_SIN)
10536 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_SINF)
10537 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_SINL))
10538 && operand_equal_p (CALL_EXPR_ARG (arg0, 0),
10539 CALL_EXPR_ARG (arg1, 0), 0))
10541 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
10543 if (tanfn != NULL_TREE)
10545 tree tmp = build_call_expr (tanfn, 1, CALL_EXPR_ARG (arg0, 0));
10546 return fold_build2 (RDIV_EXPR, type,
10547 build_real (type, dconst1), tmp);
10551 /* Optimize sin(x)/tan(x) as cos(x) if we don't care about
10552 NaNs or Infinities. */
10553 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_TAN)
10554 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_TANF)
10555 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_TANL)))
10557 tree arg00 = CALL_EXPR_ARG (arg0, 0);
10558 tree arg01 = CALL_EXPR_ARG (arg1, 0);
10560 if (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg00)))
10561 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg00)))
10562 && operand_equal_p (arg00, arg01, 0))
10564 tree cosfn = mathfn_built_in (type, BUILT_IN_COS);
10566 if (cosfn != NULL_TREE)
10567 return build_call_expr (cosfn, 1, arg00);
10571 /* Optimize tan(x)/sin(x) as 1.0/cos(x) if we don't care about
10572 NaNs or Infinities. */
10573 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_SIN)
10574 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_SINF)
10575 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_SINL)))
10577 tree arg00 = CALL_EXPR_ARG (arg0, 0);
10578 tree arg01 = CALL_EXPR_ARG (arg1, 0);
10580 if (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg00)))
10581 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg00)))
10582 && operand_equal_p (arg00, arg01, 0))
10584 tree cosfn = mathfn_built_in (type, BUILT_IN_COS);
10586 if (cosfn != NULL_TREE)
10588 tree tmp = build_call_expr (cosfn, 1, arg00);
10589 return fold_build2 (RDIV_EXPR, type,
10590 build_real (type, dconst1),
10596 /* Optimize pow(x,c)/x as pow(x,c-1). */
10597 if (fcode0 == BUILT_IN_POW
10598 || fcode0 == BUILT_IN_POWF
10599 || fcode0 == BUILT_IN_POWL)
10601 tree arg00 = CALL_EXPR_ARG (arg0, 0);
10602 tree arg01 = CALL_EXPR_ARG (arg0, 1);
10603 if (TREE_CODE (arg01) == REAL_CST
10604 && !TREE_OVERFLOW (arg01)
10605 && operand_equal_p (arg1, arg00, 0))
10607 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10611 c = TREE_REAL_CST (arg01);
10612 real_arithmetic (&c, MINUS_EXPR, &c, &dconst1);
10613 arg = build_real (type, c);
10614 return build_call_expr (powfn, 2, arg1, arg);
10618 /* Optimize x/expN(y) into x*expN(-y). */
10619 if (BUILTIN_EXPONENT_P (fcode1))
10621 tree expfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
10622 tree arg = negate_expr (CALL_EXPR_ARG (arg1, 0));
10623 arg1 = build_call_expr (expfn, 1, fold_convert (type, arg));
10624 return fold_build2 (MULT_EXPR, type, arg0, arg1);
10627 /* Optimize x/pow(y,z) into x*pow(y,-z). */
10628 if (fcode1 == BUILT_IN_POW
10629 || fcode1 == BUILT_IN_POWF
10630 || fcode1 == BUILT_IN_POWL)
10632 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
10633 tree arg10 = CALL_EXPR_ARG (arg1, 0);
10634 tree arg11 = CALL_EXPR_ARG (arg1, 1);
10635 tree neg11 = fold_convert (type, negate_expr (arg11));
10636 arg1 = build_call_expr (powfn, 2, arg10, neg11);
10637 return fold_build2 (MULT_EXPR, type, arg0, arg1);
10642 case TRUNC_DIV_EXPR:
10643 case FLOOR_DIV_EXPR:
10644 /* Simplify A / (B << N) where A and B are positive and B is
10645 a power of 2, to A >> (N + log2(B)). */
10646 strict_overflow_p = false;
10647 if (TREE_CODE (arg1) == LSHIFT_EXPR
10648 && (TYPE_UNSIGNED (type)
10649 || tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p)))
10651 tree sval = TREE_OPERAND (arg1, 0);
10652 if (integer_pow2p (sval) && tree_int_cst_sgn (sval) > 0)
10654 tree sh_cnt = TREE_OPERAND (arg1, 1);
10655 unsigned long pow2 = exact_log2 (TREE_INT_CST_LOW (sval));
10657 if (strict_overflow_p)
10658 fold_overflow_warning (("assuming signed overflow does not "
10659 "occur when simplifying A / (B << N)"),
10660 WARN_STRICT_OVERFLOW_MISC);
10662 sh_cnt = fold_build2 (PLUS_EXPR, TREE_TYPE (sh_cnt),
10663 sh_cnt, build_int_cst (NULL_TREE, pow2));
10664 return fold_build2 (RSHIFT_EXPR, type,
10665 fold_convert (type, arg0), sh_cnt);
10670 case ROUND_DIV_EXPR:
10671 case CEIL_DIV_EXPR:
10672 case EXACT_DIV_EXPR:
10673 if (integer_onep (arg1))
10674 return non_lvalue (fold_convert (type, arg0));
10675 if (integer_zerop (arg1))
10677 /* X / -1 is -X. */
10678 if (!TYPE_UNSIGNED (type)
10679 && TREE_CODE (arg1) == INTEGER_CST
10680 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
10681 && TREE_INT_CST_HIGH (arg1) == -1)
10682 return fold_convert (type, negate_expr (arg0));
10684 /* Convert -A / -B to A / B when the type is signed and overflow is
10686 if ((!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
10687 && TREE_CODE (arg0) == NEGATE_EXPR
10688 && negate_expr_p (arg1))
10690 if (INTEGRAL_TYPE_P (type))
10691 fold_overflow_warning (("assuming signed overflow does not occur "
10692 "when distributing negation across "
10694 WARN_STRICT_OVERFLOW_MISC);
10695 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
10696 negate_expr (arg1));
10698 if ((!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
10699 && TREE_CODE (arg1) == NEGATE_EXPR
10700 && negate_expr_p (arg0))
10702 if (INTEGRAL_TYPE_P (type))
10703 fold_overflow_warning (("assuming signed overflow does not occur "
10704 "when distributing negation across "
10706 WARN_STRICT_OVERFLOW_MISC);
10707 return fold_build2 (code, type, negate_expr (arg0),
10708 TREE_OPERAND (arg1, 0));
10711 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
10712 operation, EXACT_DIV_EXPR.
10714 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
10715 At one time others generated faster code, it's not clear if they do
10716 after the last round to changes to the DIV code in expmed.c. */
10717 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
10718 && multiple_of_p (type, arg0, arg1))
10719 return fold_build2 (EXACT_DIV_EXPR, type, arg0, arg1);
10721 strict_overflow_p = false;
10722 if (TREE_CODE (arg1) == INTEGER_CST
10723 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
10724 &strict_overflow_p)))
10726 if (strict_overflow_p)
10727 fold_overflow_warning (("assuming signed overflow does not occur "
10728 "when simplifying division"),
10729 WARN_STRICT_OVERFLOW_MISC);
10730 return fold_convert (type, tem);
10735 case CEIL_MOD_EXPR:
10736 case FLOOR_MOD_EXPR:
10737 case ROUND_MOD_EXPR:
10738 case TRUNC_MOD_EXPR:
10739 /* X % 1 is always zero, but be sure to preserve any side
10741 if (integer_onep (arg1))
10742 return omit_one_operand (type, integer_zero_node, arg0);
10744 /* X % 0, return X % 0 unchanged so that we can get the
10745 proper warnings and errors. */
10746 if (integer_zerop (arg1))
10749 /* 0 % X is always zero, but be sure to preserve any side
10750 effects in X. Place this after checking for X == 0. */
10751 if (integer_zerop (arg0))
10752 return omit_one_operand (type, integer_zero_node, arg1);
10754 /* X % -1 is zero. */
10755 if (!TYPE_UNSIGNED (type)
10756 && TREE_CODE (arg1) == INTEGER_CST
10757 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
10758 && TREE_INT_CST_HIGH (arg1) == -1)
10759 return omit_one_operand (type, integer_zero_node, arg0);
10761 /* Optimize TRUNC_MOD_EXPR by a power of two into a BIT_AND_EXPR,
10762 i.e. "X % C" into "X & (C - 1)", if X and C are positive. */
10763 strict_overflow_p = false;
10764 if ((code == TRUNC_MOD_EXPR || code == FLOOR_MOD_EXPR)
10765 && (TYPE_UNSIGNED (type)
10766 || tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p)))
10769 /* Also optimize A % (C << N) where C is a power of 2,
10770 to A & ((C << N) - 1). */
10771 if (TREE_CODE (arg1) == LSHIFT_EXPR)
10772 c = TREE_OPERAND (arg1, 0);
10774 if (integer_pow2p (c) && tree_int_cst_sgn (c) > 0)
10776 tree mask = fold_build2 (MINUS_EXPR, TREE_TYPE (arg1), arg1,
10777 build_int_cst (TREE_TYPE (arg1), 1));
10778 if (strict_overflow_p)
10779 fold_overflow_warning (("assuming signed overflow does not "
10780 "occur when simplifying "
10781 "X % (power of two)"),
10782 WARN_STRICT_OVERFLOW_MISC);
10783 return fold_build2 (BIT_AND_EXPR, type,
10784 fold_convert (type, arg0),
10785 fold_convert (type, mask));
10789 /* X % -C is the same as X % C. */
10790 if (code == TRUNC_MOD_EXPR
10791 && !TYPE_UNSIGNED (type)
10792 && TREE_CODE (arg1) == INTEGER_CST
10793 && !TREE_OVERFLOW (arg1)
10794 && TREE_INT_CST_HIGH (arg1) < 0
10795 && !TYPE_OVERFLOW_TRAPS (type)
10796 /* Avoid this transformation if C is INT_MIN, i.e. C == -C. */
10797 && !sign_bit_p (arg1, arg1))
10798 return fold_build2 (code, type, fold_convert (type, arg0),
10799 fold_convert (type, negate_expr (arg1)));
10801 /* X % -Y is the same as X % Y. */
10802 if (code == TRUNC_MOD_EXPR
10803 && !TYPE_UNSIGNED (type)
10804 && TREE_CODE (arg1) == NEGATE_EXPR
10805 && !TYPE_OVERFLOW_TRAPS (type))
10806 return fold_build2 (code, type, fold_convert (type, arg0),
10807 fold_convert (type, TREE_OPERAND (arg1, 0)));
10809 if (TREE_CODE (arg1) == INTEGER_CST
10810 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
10811 &strict_overflow_p)))
10813 if (strict_overflow_p)
10814 fold_overflow_warning (("assuming signed overflow does not occur "
10815 "when simplifying modulos"),
10816 WARN_STRICT_OVERFLOW_MISC);
10817 return fold_convert (type, tem);
10824 if (integer_all_onesp (arg0))
10825 return omit_one_operand (type, arg0, arg1);
10829 /* Optimize -1 >> x for arithmetic right shifts. */
10830 if (integer_all_onesp (arg0) && !TYPE_UNSIGNED (type))
10831 return omit_one_operand (type, arg0, arg1);
10832 /* ... fall through ... */
10836 if (integer_zerop (arg1))
10837 return non_lvalue (fold_convert (type, arg0));
10838 if (integer_zerop (arg0))
10839 return omit_one_operand (type, arg0, arg1);
10841 /* Since negative shift count is not well-defined,
10842 don't try to compute it in the compiler. */
10843 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
10846 /* Turn (a OP c1) OP c2 into a OP (c1+c2). */
10847 if (TREE_CODE (op0) == code && host_integerp (arg1, false)
10848 && TREE_INT_CST_LOW (arg1) < TYPE_PRECISION (type)
10849 && host_integerp (TREE_OPERAND (arg0, 1), false)
10850 && TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) < TYPE_PRECISION (type))
10852 HOST_WIDE_INT low = (TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1))
10853 + TREE_INT_CST_LOW (arg1));
10855 /* Deal with a OP (c1 + c2) being undefined but (a OP c1) OP c2
10856 being well defined. */
10857 if (low >= TYPE_PRECISION (type))
10859 if (code == LROTATE_EXPR || code == RROTATE_EXPR)
10860 low = low % TYPE_PRECISION (type);
10861 else if (TYPE_UNSIGNED (type) || code == LSHIFT_EXPR)
10862 return build_int_cst (type, 0);
10864 low = TYPE_PRECISION (type) - 1;
10867 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
10868 build_int_cst (type, low));
10871 /* Transform (x >> c) << c into x & (-1<<c), or transform (x << c) >> c
10872 into x & ((unsigned)-1 >> c) for unsigned types. */
10873 if (((code == LSHIFT_EXPR && TREE_CODE (arg0) == RSHIFT_EXPR)
10874 || (TYPE_UNSIGNED (type)
10875 && code == RSHIFT_EXPR && TREE_CODE (arg0) == LSHIFT_EXPR))
10876 && host_integerp (arg1, false)
10877 && TREE_INT_CST_LOW (arg1) < TYPE_PRECISION (type)
10878 && host_integerp (TREE_OPERAND (arg0, 1), false)
10879 && TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) < TYPE_PRECISION (type))
10881 HOST_WIDE_INT low0 = TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1));
10882 HOST_WIDE_INT low1 = TREE_INT_CST_LOW (arg1);
10888 arg00 = fold_convert (type, TREE_OPERAND (arg0, 0));
10890 lshift = build_int_cst (type, -1);
10891 lshift = int_const_binop (code, lshift, arg1, 0);
10893 return fold_build2 (BIT_AND_EXPR, type, arg00, lshift);
10897 /* Rewrite an LROTATE_EXPR by a constant into an
10898 RROTATE_EXPR by a new constant. */
10899 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
10901 tree tem = build_int_cst (TREE_TYPE (arg1),
10902 GET_MODE_BITSIZE (TYPE_MODE (type)));
10903 tem = const_binop (MINUS_EXPR, tem, arg1, 0);
10904 return fold_build2 (RROTATE_EXPR, type, arg0, tem);
10907 /* If we have a rotate of a bit operation with the rotate count and
10908 the second operand of the bit operation both constant,
10909 permute the two operations. */
10910 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
10911 && (TREE_CODE (arg0) == BIT_AND_EXPR
10912 || TREE_CODE (arg0) == BIT_IOR_EXPR
10913 || TREE_CODE (arg0) == BIT_XOR_EXPR)
10914 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
10915 return fold_build2 (TREE_CODE (arg0), type,
10916 fold_build2 (code, type,
10917 TREE_OPERAND (arg0, 0), arg1),
10918 fold_build2 (code, type,
10919 TREE_OPERAND (arg0, 1), arg1));
10921 /* Two consecutive rotates adding up to the width of the mode can
10923 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
10924 && TREE_CODE (arg0) == RROTATE_EXPR
10925 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
10926 && TREE_INT_CST_HIGH (arg1) == 0
10927 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
10928 && ((TREE_INT_CST_LOW (arg1)
10929 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
10930 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type))))
10931 return TREE_OPERAND (arg0, 0);
10936 if (operand_equal_p (arg0, arg1, 0))
10937 return omit_one_operand (type, arg0, arg1);
10938 if (INTEGRAL_TYPE_P (type)
10939 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
10940 return omit_one_operand (type, arg1, arg0);
10941 tem = fold_minmax (MIN_EXPR, type, arg0, arg1);
10947 if (operand_equal_p (arg0, arg1, 0))
10948 return omit_one_operand (type, arg0, arg1);
10949 if (INTEGRAL_TYPE_P (type)
10950 && TYPE_MAX_VALUE (type)
10951 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
10952 return omit_one_operand (type, arg1, arg0);
10953 tem = fold_minmax (MAX_EXPR, type, arg0, arg1);
10958 case TRUTH_ANDIF_EXPR:
10959 /* Note that the operands of this must be ints
10960 and their values must be 0 or 1.
10961 ("true" is a fixed value perhaps depending on the language.) */
10962 /* If first arg is constant zero, return it. */
10963 if (integer_zerop (arg0))
10964 return fold_convert (type, arg0);
10965 case TRUTH_AND_EXPR:
10966 /* If either arg is constant true, drop it. */
10967 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
10968 return non_lvalue (fold_convert (type, arg1));
10969 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
10970 /* Preserve sequence points. */
10971 && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
10972 return non_lvalue (fold_convert (type, arg0));
10973 /* If second arg is constant zero, result is zero, but first arg
10974 must be evaluated. */
10975 if (integer_zerop (arg1))
10976 return omit_one_operand (type, arg1, arg0);
10977 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
10978 case will be handled here. */
10979 if (integer_zerop (arg0))
10980 return omit_one_operand (type, arg0, arg1);
10982 /* !X && X is always false. */
10983 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
10984 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10985 return omit_one_operand (type, integer_zero_node, arg1);
10986 /* X && !X is always false. */
10987 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
10988 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10989 return omit_one_operand (type, integer_zero_node, arg0);
10991 /* A < X && A + 1 > Y ==> A < X && A >= Y. Normally A + 1 > Y
10992 means A >= Y && A != MAX, but in this case we know that
10995 if (!TREE_SIDE_EFFECTS (arg0)
10996 && !TREE_SIDE_EFFECTS (arg1))
10998 tem = fold_to_nonsharp_ineq_using_bound (arg0, arg1);
10999 if (tem && !operand_equal_p (tem, arg0, 0))
11000 return fold_build2 (code, type, tem, arg1);
11002 tem = fold_to_nonsharp_ineq_using_bound (arg1, arg0);
11003 if (tem && !operand_equal_p (tem, arg1, 0))
11004 return fold_build2 (code, type, arg0, tem);
11008 /* We only do these simplifications if we are optimizing. */
11012 /* Check for things like (A || B) && (A || C). We can convert this
11013 to A || (B && C). Note that either operator can be any of the four
11014 truth and/or operations and the transformation will still be
11015 valid. Also note that we only care about order for the
11016 ANDIF and ORIF operators. If B contains side effects, this
11017 might change the truth-value of A. */
11018 if (TREE_CODE (arg0) == TREE_CODE (arg1)
11019 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
11020 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
11021 || TREE_CODE (arg0) == TRUTH_AND_EXPR
11022 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
11023 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
11025 tree a00 = TREE_OPERAND (arg0, 0);
11026 tree a01 = TREE_OPERAND (arg0, 1);
11027 tree a10 = TREE_OPERAND (arg1, 0);
11028 tree a11 = TREE_OPERAND (arg1, 1);
11029 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
11030 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
11031 && (code == TRUTH_AND_EXPR
11032 || code == TRUTH_OR_EXPR));
11034 if (operand_equal_p (a00, a10, 0))
11035 return fold_build2 (TREE_CODE (arg0), type, a00,
11036 fold_build2 (code, type, a01, a11));
11037 else if (commutative && operand_equal_p (a00, a11, 0))
11038 return fold_build2 (TREE_CODE (arg0), type, a00,
11039 fold_build2 (code, type, a01, a10));
11040 else if (commutative && operand_equal_p (a01, a10, 0))
11041 return fold_build2 (TREE_CODE (arg0), type, a01,
11042 fold_build2 (code, type, a00, a11));
11044 /* This case if tricky because we must either have commutative
11045 operators or else A10 must not have side-effects. */
11047 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
11048 && operand_equal_p (a01, a11, 0))
11049 return fold_build2 (TREE_CODE (arg0), type,
11050 fold_build2 (code, type, a00, a10),
11054 /* See if we can build a range comparison. */
11055 if (0 != (tem = fold_range_test (code, type, op0, op1)))
11058 /* Check for the possibility of merging component references. If our
11059 lhs is another similar operation, try to merge its rhs with our
11060 rhs. Then try to merge our lhs and rhs. */
11061 if (TREE_CODE (arg0) == code
11062 && 0 != (tem = fold_truthop (code, type,
11063 TREE_OPERAND (arg0, 1), arg1)))
11064 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
11066 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
11071 case TRUTH_ORIF_EXPR:
11072 /* Note that the operands of this must be ints
11073 and their values must be 0 or true.
11074 ("true" is a fixed value perhaps depending on the language.) */
11075 /* If first arg is constant true, return it. */
11076 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
11077 return fold_convert (type, arg0);
11078 case TRUTH_OR_EXPR:
11079 /* If either arg is constant zero, drop it. */
11080 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
11081 return non_lvalue (fold_convert (type, arg1));
11082 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
11083 /* Preserve sequence points. */
11084 && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
11085 return non_lvalue (fold_convert (type, arg0));
11086 /* If second arg is constant true, result is true, but we must
11087 evaluate first arg. */
11088 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
11089 return omit_one_operand (type, arg1, arg0);
11090 /* Likewise for first arg, but note this only occurs here for
11092 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
11093 return omit_one_operand (type, arg0, arg1);
11095 /* !X || X is always true. */
11096 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
11097 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
11098 return omit_one_operand (type, integer_one_node, arg1);
11099 /* X || !X is always true. */
11100 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
11101 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
11102 return omit_one_operand (type, integer_one_node, arg0);
11106 case TRUTH_XOR_EXPR:
11107 /* If the second arg is constant zero, drop it. */
11108 if (integer_zerop (arg1))
11109 return non_lvalue (fold_convert (type, arg0));
11110 /* If the second arg is constant true, this is a logical inversion. */
11111 if (integer_onep (arg1))
11113 /* Only call invert_truthvalue if operand is a truth value. */
11114 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
11115 tem = fold_build1 (TRUTH_NOT_EXPR, TREE_TYPE (arg0), arg0);
11117 tem = invert_truthvalue (arg0);
11118 return non_lvalue (fold_convert (type, tem));
11120 /* Identical arguments cancel to zero. */
11121 if (operand_equal_p (arg0, arg1, 0))
11122 return omit_one_operand (type, integer_zero_node, arg0);
11124 /* !X ^ X is always true. */
11125 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
11126 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
11127 return omit_one_operand (type, integer_one_node, arg1);
11129 /* X ^ !X is always true. */
11130 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
11131 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
11132 return omit_one_operand (type, integer_one_node, arg0);
11138 tem = fold_comparison (code, type, op0, op1);
11139 if (tem != NULL_TREE)
11142 /* bool_var != 0 becomes bool_var. */
11143 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_zerop (arg1)
11144 && code == NE_EXPR)
11145 return non_lvalue (fold_convert (type, arg0));
11147 /* bool_var == 1 becomes bool_var. */
11148 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_onep (arg1)
11149 && code == EQ_EXPR)
11150 return non_lvalue (fold_convert (type, arg0));
11152 /* bool_var != 1 becomes !bool_var. */
11153 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_onep (arg1)
11154 && code == NE_EXPR)
11155 return fold_build1 (TRUTH_NOT_EXPR, type, arg0);
11157 /* bool_var == 0 becomes !bool_var. */
11158 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_zerop (arg1)
11159 && code == EQ_EXPR)
11160 return fold_build1 (TRUTH_NOT_EXPR, type, arg0);
11162 /* If this is an equality comparison of the address of two non-weak,
11163 unaliased symbols neither of which are extern (since we do not
11164 have access to attributes for externs), then we know the result. */
11165 if (TREE_CODE (arg0) == ADDR_EXPR
11166 && VAR_OR_FUNCTION_DECL_P (TREE_OPERAND (arg0, 0))
11167 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
11168 && ! lookup_attribute ("alias",
11169 DECL_ATTRIBUTES (TREE_OPERAND (arg0, 0)))
11170 && ! DECL_EXTERNAL (TREE_OPERAND (arg0, 0))
11171 && TREE_CODE (arg1) == ADDR_EXPR
11172 && VAR_OR_FUNCTION_DECL_P (TREE_OPERAND (arg1, 0))
11173 && ! DECL_WEAK (TREE_OPERAND (arg1, 0))
11174 && ! lookup_attribute ("alias",
11175 DECL_ATTRIBUTES (TREE_OPERAND (arg1, 0)))
11176 && ! DECL_EXTERNAL (TREE_OPERAND (arg1, 0)))
11178 /* We know that we're looking at the address of two
11179 non-weak, unaliased, static _DECL nodes.
11181 It is both wasteful and incorrect to call operand_equal_p
11182 to compare the two ADDR_EXPR nodes. It is wasteful in that
11183 all we need to do is test pointer equality for the arguments
11184 to the two ADDR_EXPR nodes. It is incorrect to use
11185 operand_equal_p as that function is NOT equivalent to a
11186 C equality test. It can in fact return false for two
11187 objects which would test as equal using the C equality
11189 bool equal = TREE_OPERAND (arg0, 0) == TREE_OPERAND (arg1, 0);
11190 return constant_boolean_node (equal
11191 ? code == EQ_EXPR : code != EQ_EXPR,
11195 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
11196 a MINUS_EXPR of a constant, we can convert it into a comparison with
11197 a revised constant as long as no overflow occurs. */
11198 if (TREE_CODE (arg1) == INTEGER_CST
11199 && (TREE_CODE (arg0) == PLUS_EXPR
11200 || TREE_CODE (arg0) == MINUS_EXPR)
11201 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
11202 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
11203 ? MINUS_EXPR : PLUS_EXPR,
11204 fold_convert (TREE_TYPE (arg0), arg1),
11205 TREE_OPERAND (arg0, 1), 0))
11206 && !TREE_OVERFLOW (tem))
11207 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
11209 /* Similarly for a NEGATE_EXPR. */
11210 if (TREE_CODE (arg0) == NEGATE_EXPR
11211 && TREE_CODE (arg1) == INTEGER_CST
11212 && 0 != (tem = negate_expr (arg1))
11213 && TREE_CODE (tem) == INTEGER_CST
11214 && !TREE_OVERFLOW (tem))
11215 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
11217 /* Similarly for a BIT_XOR_EXPR; X ^ C1 == C2 is X == (C1 ^ C2). */
11218 if (TREE_CODE (arg0) == BIT_XOR_EXPR
11219 && TREE_CODE (arg1) == INTEGER_CST
11220 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11221 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
11222 fold_build2 (BIT_XOR_EXPR, TREE_TYPE (arg0),
11223 fold_convert (TREE_TYPE (arg0), arg1),
11224 TREE_OPERAND (arg0, 1)));
11226 /* Transform comparisons of the form X +- C CMP X. */
11227 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
11228 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
11229 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
11230 && (INTEGRAL_TYPE_P (TREE_TYPE (arg0))
11231 || POINTER_TYPE_P (TREE_TYPE (arg0))))
11233 tree cst = TREE_OPERAND (arg0, 1);
11235 if (code == EQ_EXPR
11236 && !integer_zerop (cst))
11237 return omit_two_operands (type, boolean_false_node,
11238 TREE_OPERAND (arg0, 0), arg1);
11240 return omit_two_operands (type, boolean_true_node,
11241 TREE_OPERAND (arg0, 0), arg1);
11244 /* If we have X - Y == 0, we can convert that to X == Y and similarly
11245 for !=. Don't do this for ordered comparisons due to overflow. */
11246 if (TREE_CODE (arg0) == MINUS_EXPR
11247 && integer_zerop (arg1))
11248 return fold_build2 (code, type,
11249 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
11251 /* Convert ABS_EXPR<x> == 0 or ABS_EXPR<x> != 0 to x == 0 or x != 0. */
11252 if (TREE_CODE (arg0) == ABS_EXPR
11253 && (integer_zerop (arg1) || real_zerop (arg1)))
11254 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), arg1);
11256 /* If this is an EQ or NE comparison with zero and ARG0 is
11257 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
11258 two operations, but the latter can be done in one less insn
11259 on machines that have only two-operand insns or on which a
11260 constant cannot be the first operand. */
11261 if (TREE_CODE (arg0) == BIT_AND_EXPR
11262 && integer_zerop (arg1))
11264 tree arg00 = TREE_OPERAND (arg0, 0);
11265 tree arg01 = TREE_OPERAND (arg0, 1);
11266 if (TREE_CODE (arg00) == LSHIFT_EXPR
11267 && integer_onep (TREE_OPERAND (arg00, 0)))
11269 fold_build2 (code, type,
11270 build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
11271 build2 (RSHIFT_EXPR, TREE_TYPE (arg00),
11272 arg01, TREE_OPERAND (arg00, 1)),
11273 fold_convert (TREE_TYPE (arg0),
11274 integer_one_node)),
11276 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
11277 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
11279 fold_build2 (code, type,
11280 build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
11281 build2 (RSHIFT_EXPR, TREE_TYPE (arg01),
11282 arg00, TREE_OPERAND (arg01, 1)),
11283 fold_convert (TREE_TYPE (arg0),
11284 integer_one_node)),
11288 /* If this is an NE or EQ comparison of zero against the result of a
11289 signed MOD operation whose second operand is a power of 2, make
11290 the MOD operation unsigned since it is simpler and equivalent. */
11291 if (integer_zerop (arg1)
11292 && !TYPE_UNSIGNED (TREE_TYPE (arg0))
11293 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
11294 || TREE_CODE (arg0) == CEIL_MOD_EXPR
11295 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
11296 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
11297 && integer_pow2p (TREE_OPERAND (arg0, 1)))
11299 tree newtype = lang_hooks.types.unsigned_type (TREE_TYPE (arg0));
11300 tree newmod = fold_build2 (TREE_CODE (arg0), newtype,
11301 fold_convert (newtype,
11302 TREE_OPERAND (arg0, 0)),
11303 fold_convert (newtype,
11304 TREE_OPERAND (arg0, 1)));
11306 return fold_build2 (code, type, newmod,
11307 fold_convert (newtype, arg1));
11310 /* Fold ((X >> C1) & C2) == 0 and ((X >> C1) & C2) != 0 where
11311 C1 is a valid shift constant, and C2 is a power of two, i.e.
11313 if (TREE_CODE (arg0) == BIT_AND_EXPR
11314 && TREE_CODE (TREE_OPERAND (arg0, 0)) == RSHIFT_EXPR
11315 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1))
11317 && integer_pow2p (TREE_OPERAND (arg0, 1))
11318 && integer_zerop (arg1))
11320 tree itype = TREE_TYPE (arg0);
11321 unsigned HOST_WIDE_INT prec = TYPE_PRECISION (itype);
11322 tree arg001 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 1);
11324 /* Check for a valid shift count. */
11325 if (TREE_INT_CST_HIGH (arg001) == 0
11326 && TREE_INT_CST_LOW (arg001) < prec)
11328 tree arg01 = TREE_OPERAND (arg0, 1);
11329 tree arg000 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
11330 unsigned HOST_WIDE_INT log2 = tree_log2 (arg01);
11331 /* If (C2 << C1) doesn't overflow, then ((X >> C1) & C2) != 0
11332 can be rewritten as (X & (C2 << C1)) != 0. */
11333 if ((log2 + TREE_INT_CST_LOW (arg001)) < prec)
11335 tem = fold_build2 (LSHIFT_EXPR, itype, arg01, arg001);
11336 tem = fold_build2 (BIT_AND_EXPR, itype, arg000, tem);
11337 return fold_build2 (code, type, tem, arg1);
11339 /* Otherwise, for signed (arithmetic) shifts,
11340 ((X >> C1) & C2) != 0 is rewritten as X < 0, and
11341 ((X >> C1) & C2) == 0 is rewritten as X >= 0. */
11342 else if (!TYPE_UNSIGNED (itype))
11343 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR, type,
11344 arg000, build_int_cst (itype, 0));
11345 /* Otherwise, of unsigned (logical) shifts,
11346 ((X >> C1) & C2) != 0 is rewritten as (X,false), and
11347 ((X >> C1) & C2) == 0 is rewritten as (X,true). */
11349 return omit_one_operand (type,
11350 code == EQ_EXPR ? integer_one_node
11351 : integer_zero_node,
11356 /* If this is an NE comparison of zero with an AND of one, remove the
11357 comparison since the AND will give the correct value. */
11358 if (code == NE_EXPR
11359 && integer_zerop (arg1)
11360 && TREE_CODE (arg0) == BIT_AND_EXPR
11361 && integer_onep (TREE_OPERAND (arg0, 1)))
11362 return fold_convert (type, arg0);
11364 /* If we have (A & C) == C where C is a power of 2, convert this into
11365 (A & C) != 0. Similarly for NE_EXPR. */
11366 if (TREE_CODE (arg0) == BIT_AND_EXPR
11367 && integer_pow2p (TREE_OPERAND (arg0, 1))
11368 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
11369 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
11370 arg0, fold_convert (TREE_TYPE (arg0),
11371 integer_zero_node));
11373 /* If we have (A & C) != 0 or (A & C) == 0 and C is the sign
11374 bit, then fold the expression into A < 0 or A >= 0. */
11375 tem = fold_single_bit_test_into_sign_test (code, arg0, arg1, type);
11379 /* If we have (A & C) == D where D & ~C != 0, convert this into 0.
11380 Similarly for NE_EXPR. */
11381 if (TREE_CODE (arg0) == BIT_AND_EXPR
11382 && TREE_CODE (arg1) == INTEGER_CST
11383 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11385 tree notc = fold_build1 (BIT_NOT_EXPR,
11386 TREE_TYPE (TREE_OPERAND (arg0, 1)),
11387 TREE_OPERAND (arg0, 1));
11388 tree dandnotc = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
11390 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
11391 if (integer_nonzerop (dandnotc))
11392 return omit_one_operand (type, rslt, arg0);
11395 /* If we have (A | C) == D where C & ~D != 0, convert this into 0.
11396 Similarly for NE_EXPR. */
11397 if (TREE_CODE (arg0) == BIT_IOR_EXPR
11398 && TREE_CODE (arg1) == INTEGER_CST
11399 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11401 tree notd = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1), arg1);
11402 tree candnotd = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
11403 TREE_OPERAND (arg0, 1), notd);
11404 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
11405 if (integer_nonzerop (candnotd))
11406 return omit_one_operand (type, rslt, arg0);
11409 /* If this is a comparison of a field, we may be able to simplify it. */
11410 if ((TREE_CODE (arg0) == COMPONENT_REF
11411 || TREE_CODE (arg0) == BIT_FIELD_REF)
11412 /* Handle the constant case even without -O
11413 to make sure the warnings are given. */
11414 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
11416 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
11421 /* Optimize comparisons of strlen vs zero to a compare of the
11422 first character of the string vs zero. To wit,
11423 strlen(ptr) == 0 => *ptr == 0
11424 strlen(ptr) != 0 => *ptr != 0
11425 Other cases should reduce to one of these two (or a constant)
11426 due to the return value of strlen being unsigned. */
11427 if (TREE_CODE (arg0) == CALL_EXPR
11428 && integer_zerop (arg1))
11430 tree fndecl = get_callee_fndecl (arg0);
11433 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
11434 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
11435 && call_expr_nargs (arg0) == 1
11436 && TREE_CODE (TREE_TYPE (CALL_EXPR_ARG (arg0, 0))) == POINTER_TYPE)
11438 tree iref = build_fold_indirect_ref (CALL_EXPR_ARG (arg0, 0));
11439 return fold_build2 (code, type, iref,
11440 build_int_cst (TREE_TYPE (iref), 0));
11444 /* Fold (X >> C) != 0 into X < 0 if C is one less than the width
11445 of X. Similarly fold (X >> C) == 0 into X >= 0. */
11446 if (TREE_CODE (arg0) == RSHIFT_EXPR
11447 && integer_zerop (arg1)
11448 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11450 tree arg00 = TREE_OPERAND (arg0, 0);
11451 tree arg01 = TREE_OPERAND (arg0, 1);
11452 tree itype = TREE_TYPE (arg00);
11453 if (TREE_INT_CST_HIGH (arg01) == 0
11454 && TREE_INT_CST_LOW (arg01)
11455 == (unsigned HOST_WIDE_INT) (TYPE_PRECISION (itype) - 1))
11457 if (TYPE_UNSIGNED (itype))
11459 itype = lang_hooks.types.signed_type (itype);
11460 arg00 = fold_convert (itype, arg00);
11462 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
11463 type, arg00, build_int_cst (itype, 0));
11467 /* (X ^ Y) == 0 becomes X == Y, and (X ^ Y) != 0 becomes X != Y. */
11468 if (integer_zerop (arg1)
11469 && TREE_CODE (arg0) == BIT_XOR_EXPR)
11470 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
11471 TREE_OPERAND (arg0, 1));
11473 /* (X ^ Y) == Y becomes X == 0. We know that Y has no side-effects. */
11474 if (TREE_CODE (arg0) == BIT_XOR_EXPR
11475 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
11476 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
11477 build_int_cst (TREE_TYPE (arg1), 0));
11478 /* Likewise (X ^ Y) == X becomes Y == 0. X has no side-effects. */
11479 if (TREE_CODE (arg0) == BIT_XOR_EXPR
11480 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
11481 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
11482 return fold_build2 (code, type, TREE_OPERAND (arg0, 1),
11483 build_int_cst (TREE_TYPE (arg1), 0));
11485 /* (X ^ C1) op C2 can be rewritten as X op (C1 ^ C2). */
11486 if (TREE_CODE (arg0) == BIT_XOR_EXPR
11487 && TREE_CODE (arg1) == INTEGER_CST
11488 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11489 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
11490 fold_build2 (BIT_XOR_EXPR, TREE_TYPE (arg1),
11491 TREE_OPERAND (arg0, 1), arg1));
11493 /* Fold (~X & C) == 0 into (X & C) != 0 and (~X & C) != 0 into
11494 (X & C) == 0 when C is a single bit. */
11495 if (TREE_CODE (arg0) == BIT_AND_EXPR
11496 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_NOT_EXPR
11497 && integer_zerop (arg1)
11498 && integer_pow2p (TREE_OPERAND (arg0, 1)))
11500 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
11501 TREE_OPERAND (TREE_OPERAND (arg0, 0), 0),
11502 TREE_OPERAND (arg0, 1));
11503 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR,
11507 /* Fold ((X & C) ^ C) eq/ne 0 into (X & C) ne/eq 0, when the
11508 constant C is a power of two, i.e. a single bit. */
11509 if (TREE_CODE (arg0) == BIT_XOR_EXPR
11510 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
11511 && integer_zerop (arg1)
11512 && integer_pow2p (TREE_OPERAND (arg0, 1))
11513 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
11514 TREE_OPERAND (arg0, 1), OEP_ONLY_CONST))
11516 tree arg00 = TREE_OPERAND (arg0, 0);
11517 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
11518 arg00, build_int_cst (TREE_TYPE (arg00), 0));
11521 /* Likewise, fold ((X ^ C) & C) eq/ne 0 into (X & C) ne/eq 0,
11522 when is C is a power of two, i.e. a single bit. */
11523 if (TREE_CODE (arg0) == BIT_AND_EXPR
11524 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_XOR_EXPR
11525 && integer_zerop (arg1)
11526 && integer_pow2p (TREE_OPERAND (arg0, 1))
11527 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
11528 TREE_OPERAND (arg0, 1), OEP_ONLY_CONST))
11530 tree arg000 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
11531 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg000),
11532 arg000, TREE_OPERAND (arg0, 1));
11533 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
11534 tem, build_int_cst (TREE_TYPE (tem), 0));
11537 if (integer_zerop (arg1)
11538 && tree_expr_nonzero_p (arg0))
11540 tree res = constant_boolean_node (code==NE_EXPR, type);
11541 return omit_one_operand (type, res, arg0);
11544 /* Fold -X op -Y as X op Y, where op is eq/ne. */
11545 if (TREE_CODE (arg0) == NEGATE_EXPR
11546 && TREE_CODE (arg1) == NEGATE_EXPR)
11547 return fold_build2 (code, type,
11548 TREE_OPERAND (arg0, 0),
11549 TREE_OPERAND (arg1, 0));
11551 /* Fold (X & C) op (Y & C) as (X ^ Y) & C op 0", and symmetries. */
11552 if (TREE_CODE (arg0) == BIT_AND_EXPR
11553 && TREE_CODE (arg1) == BIT_AND_EXPR)
11555 tree arg00 = TREE_OPERAND (arg0, 0);
11556 tree arg01 = TREE_OPERAND (arg0, 1);
11557 tree arg10 = TREE_OPERAND (arg1, 0);
11558 tree arg11 = TREE_OPERAND (arg1, 1);
11559 tree itype = TREE_TYPE (arg0);
11561 if (operand_equal_p (arg01, arg11, 0))
11562 return fold_build2 (code, type,
11563 fold_build2 (BIT_AND_EXPR, itype,
11564 fold_build2 (BIT_XOR_EXPR, itype,
11567 build_int_cst (itype, 0));
11569 if (operand_equal_p (arg01, arg10, 0))
11570 return fold_build2 (code, type,
11571 fold_build2 (BIT_AND_EXPR, itype,
11572 fold_build2 (BIT_XOR_EXPR, itype,
11575 build_int_cst (itype, 0));
11577 if (operand_equal_p (arg00, arg11, 0))
11578 return fold_build2 (code, type,
11579 fold_build2 (BIT_AND_EXPR, itype,
11580 fold_build2 (BIT_XOR_EXPR, itype,
11583 build_int_cst (itype, 0));
11585 if (operand_equal_p (arg00, arg10, 0))
11586 return fold_build2 (code, type,
11587 fold_build2 (BIT_AND_EXPR, itype,
11588 fold_build2 (BIT_XOR_EXPR, itype,
11591 build_int_cst (itype, 0));
11594 if (TREE_CODE (arg0) == BIT_XOR_EXPR
11595 && TREE_CODE (arg1) == BIT_XOR_EXPR)
11597 tree arg00 = TREE_OPERAND (arg0, 0);
11598 tree arg01 = TREE_OPERAND (arg0, 1);
11599 tree arg10 = TREE_OPERAND (arg1, 0);
11600 tree arg11 = TREE_OPERAND (arg1, 1);
11601 tree itype = TREE_TYPE (arg0);
11603 /* Optimize (X ^ Z) op (Y ^ Z) as X op Y, and symmetries.
11604 operand_equal_p guarantees no side-effects so we don't need
11605 to use omit_one_operand on Z. */
11606 if (operand_equal_p (arg01, arg11, 0))
11607 return fold_build2 (code, type, arg00, arg10);
11608 if (operand_equal_p (arg01, arg10, 0))
11609 return fold_build2 (code, type, arg00, arg11);
11610 if (operand_equal_p (arg00, arg11, 0))
11611 return fold_build2 (code, type, arg01, arg10);
11612 if (operand_equal_p (arg00, arg10, 0))
11613 return fold_build2 (code, type, arg01, arg11);
11615 /* Optimize (X ^ C1) op (Y ^ C2) as (X ^ (C1 ^ C2)) op Y. */
11616 if (TREE_CODE (arg01) == INTEGER_CST
11617 && TREE_CODE (arg11) == INTEGER_CST)
11618 return fold_build2 (code, type,
11619 fold_build2 (BIT_XOR_EXPR, itype, arg00,
11620 fold_build2 (BIT_XOR_EXPR, itype,
11630 tem = fold_comparison (code, type, op0, op1);
11631 if (tem != NULL_TREE)
11634 /* Transform comparisons of the form X +- C CMP X. */
11635 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
11636 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
11637 && ((TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
11638 && !HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0))))
11639 || (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
11640 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))))
11642 tree arg01 = TREE_OPERAND (arg0, 1);
11643 enum tree_code code0 = TREE_CODE (arg0);
11646 if (TREE_CODE (arg01) == REAL_CST)
11647 is_positive = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg01)) ? -1 : 1;
11649 is_positive = tree_int_cst_sgn (arg01);
11651 /* (X - c) > X becomes false. */
11652 if (code == GT_EXPR
11653 && ((code0 == MINUS_EXPR && is_positive >= 0)
11654 || (code0 == PLUS_EXPR && is_positive <= 0)))
11656 if (TREE_CODE (arg01) == INTEGER_CST
11657 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
11658 fold_overflow_warning (("assuming signed overflow does not "
11659 "occur when assuming that (X - c) > X "
11660 "is always false"),
11661 WARN_STRICT_OVERFLOW_ALL);
11662 return constant_boolean_node (0, type);
11665 /* Likewise (X + c) < X becomes false. */
11666 if (code == LT_EXPR
11667 && ((code0 == PLUS_EXPR && is_positive >= 0)
11668 || (code0 == MINUS_EXPR && is_positive <= 0)))
11670 if (TREE_CODE (arg01) == INTEGER_CST
11671 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
11672 fold_overflow_warning (("assuming signed overflow does not "
11673 "occur when assuming that "
11674 "(X + c) < X is always false"),
11675 WARN_STRICT_OVERFLOW_ALL);
11676 return constant_boolean_node (0, type);
11679 /* Convert (X - c) <= X to true. */
11680 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1)))
11682 && ((code0 == MINUS_EXPR && is_positive >= 0)
11683 || (code0 == PLUS_EXPR && is_positive <= 0)))
11685 if (TREE_CODE (arg01) == INTEGER_CST
11686 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
11687 fold_overflow_warning (("assuming signed overflow does not "
11688 "occur when assuming that "
11689 "(X - c) <= X is always true"),
11690 WARN_STRICT_OVERFLOW_ALL);
11691 return constant_boolean_node (1, type);
11694 /* Convert (X + c) >= X to true. */
11695 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1)))
11697 && ((code0 == PLUS_EXPR && is_positive >= 0)
11698 || (code0 == MINUS_EXPR && is_positive <= 0)))
11700 if (TREE_CODE (arg01) == INTEGER_CST
11701 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
11702 fold_overflow_warning (("assuming signed overflow does not "
11703 "occur when assuming that "
11704 "(X + c) >= X is always true"),
11705 WARN_STRICT_OVERFLOW_ALL);
11706 return constant_boolean_node (1, type);
11709 if (TREE_CODE (arg01) == INTEGER_CST)
11711 /* Convert X + c > X and X - c < X to true for integers. */
11712 if (code == GT_EXPR
11713 && ((code0 == PLUS_EXPR && is_positive > 0)
11714 || (code0 == MINUS_EXPR && is_positive < 0)))
11716 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
11717 fold_overflow_warning (("assuming signed overflow does "
11718 "not occur when assuming that "
11719 "(X + c) > X is always true"),
11720 WARN_STRICT_OVERFLOW_ALL);
11721 return constant_boolean_node (1, type);
11724 if (code == LT_EXPR
11725 && ((code0 == MINUS_EXPR && is_positive > 0)
11726 || (code0 == PLUS_EXPR && is_positive < 0)))
11728 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
11729 fold_overflow_warning (("assuming signed overflow does "
11730 "not occur when assuming that "
11731 "(X - c) < X is always true"),
11732 WARN_STRICT_OVERFLOW_ALL);
11733 return constant_boolean_node (1, type);
11736 /* Convert X + c <= X and X - c >= X to false for integers. */
11737 if (code == LE_EXPR
11738 && ((code0 == PLUS_EXPR && is_positive > 0)
11739 || (code0 == MINUS_EXPR && is_positive < 0)))
11741 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
11742 fold_overflow_warning (("assuming signed overflow does "
11743 "not occur when assuming that "
11744 "(X + c) <= X is always false"),
11745 WARN_STRICT_OVERFLOW_ALL);
11746 return constant_boolean_node (0, type);
11749 if (code == GE_EXPR
11750 && ((code0 == MINUS_EXPR && is_positive > 0)
11751 || (code0 == PLUS_EXPR && is_positive < 0)))
11753 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
11754 fold_overflow_warning (("assuming signed overflow does "
11755 "not occur when assuming that "
11756 "(X - c) >= X is always true"),
11757 WARN_STRICT_OVERFLOW_ALL);
11758 return constant_boolean_node (0, type);
11763 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
11764 This transformation affects the cases which are handled in later
11765 optimizations involving comparisons with non-negative constants. */
11766 if (TREE_CODE (arg1) == INTEGER_CST
11767 && TREE_CODE (arg0) != INTEGER_CST
11768 && tree_int_cst_sgn (arg1) > 0)
11770 if (code == GE_EXPR)
11772 arg1 = const_binop (MINUS_EXPR, arg1,
11773 build_int_cst (TREE_TYPE (arg1), 1), 0);
11774 return fold_build2 (GT_EXPR, type, arg0,
11775 fold_convert (TREE_TYPE (arg0), arg1));
11777 if (code == LT_EXPR)
11779 arg1 = const_binop (MINUS_EXPR, arg1,
11780 build_int_cst (TREE_TYPE (arg1), 1), 0);
11781 return fold_build2 (LE_EXPR, type, arg0,
11782 fold_convert (TREE_TYPE (arg0), arg1));
11786 /* Comparisons with the highest or lowest possible integer of
11787 the specified precision will have known values. */
11789 tree arg1_type = TREE_TYPE (arg1);
11790 unsigned int width = TYPE_PRECISION (arg1_type);
11792 if (TREE_CODE (arg1) == INTEGER_CST
11793 && !TREE_OVERFLOW (arg1)
11794 && width <= 2 * HOST_BITS_PER_WIDE_INT
11795 && (INTEGRAL_TYPE_P (arg1_type) || POINTER_TYPE_P (arg1_type)))
11797 HOST_WIDE_INT signed_max_hi;
11798 unsigned HOST_WIDE_INT signed_max_lo;
11799 unsigned HOST_WIDE_INT max_hi, max_lo, min_hi, min_lo;
11801 if (width <= HOST_BITS_PER_WIDE_INT)
11803 signed_max_lo = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
11808 if (TYPE_UNSIGNED (arg1_type))
11810 max_lo = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
11816 max_lo = signed_max_lo;
11817 min_lo = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
11823 width -= HOST_BITS_PER_WIDE_INT;
11824 signed_max_lo = -1;
11825 signed_max_hi = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
11830 if (TYPE_UNSIGNED (arg1_type))
11832 max_hi = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
11837 max_hi = signed_max_hi;
11838 min_hi = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
11842 if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1) == max_hi
11843 && TREE_INT_CST_LOW (arg1) == max_lo)
11847 return omit_one_operand (type, integer_zero_node, arg0);
11850 return fold_build2 (EQ_EXPR, type, arg0, arg1);
11853 return omit_one_operand (type, integer_one_node, arg0);
11856 return fold_build2 (NE_EXPR, type, arg0, arg1);
11858 /* The GE_EXPR and LT_EXPR cases above are not normally
11859 reached because of previous transformations. */
11864 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
11866 && TREE_INT_CST_LOW (arg1) == max_lo - 1)
11870 arg1 = const_binop (PLUS_EXPR, arg1,
11871 build_int_cst (TREE_TYPE (arg1), 1), 0);
11872 return fold_build2 (EQ_EXPR, type, arg0, arg1);
11874 arg1 = const_binop (PLUS_EXPR, arg1,
11875 build_int_cst (TREE_TYPE (arg1), 1), 0);
11876 return fold_build2 (NE_EXPR, type, arg0, arg1);
11880 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
11882 && TREE_INT_CST_LOW (arg1) == min_lo)
11886 return omit_one_operand (type, integer_zero_node, arg0);
11889 return fold_build2 (EQ_EXPR, type, arg0, arg1);
11892 return omit_one_operand (type, integer_one_node, arg0);
11895 return fold_build2 (NE_EXPR, type, op0, op1);
11900 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
11902 && TREE_INT_CST_LOW (arg1) == min_lo + 1)
11906 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
11907 return fold_build2 (NE_EXPR, type, arg0, arg1);
11909 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
11910 return fold_build2 (EQ_EXPR, type, arg0, arg1);
11915 else if (TREE_INT_CST_HIGH (arg1) == signed_max_hi
11916 && TREE_INT_CST_LOW (arg1) == signed_max_lo
11917 && TYPE_UNSIGNED (arg1_type)
11918 /* We will flip the signedness of the comparison operator
11919 associated with the mode of arg1, so the sign bit is
11920 specified by this mode. Check that arg1 is the signed
11921 max associated with this sign bit. */
11922 && width == GET_MODE_BITSIZE (TYPE_MODE (arg1_type))
11923 /* signed_type does not work on pointer types. */
11924 && INTEGRAL_TYPE_P (arg1_type))
11926 /* The following case also applies to X < signed_max+1
11927 and X >= signed_max+1 because previous transformations. */
11928 if (code == LE_EXPR || code == GT_EXPR)
11931 st0 = lang_hooks.types.signed_type (TREE_TYPE (arg0));
11932 st1 = lang_hooks.types.signed_type (TREE_TYPE (arg1));
11933 return fold_build2 (code == LE_EXPR ? GE_EXPR: LT_EXPR,
11934 type, fold_convert (st0, arg0),
11935 build_int_cst (st1, 0));
11941 /* If we are comparing an ABS_EXPR with a constant, we can
11942 convert all the cases into explicit comparisons, but they may
11943 well not be faster than doing the ABS and one comparison.
11944 But ABS (X) <= C is a range comparison, which becomes a subtraction
11945 and a comparison, and is probably faster. */
11946 if (code == LE_EXPR
11947 && TREE_CODE (arg1) == INTEGER_CST
11948 && TREE_CODE (arg0) == ABS_EXPR
11949 && ! TREE_SIDE_EFFECTS (arg0)
11950 && (0 != (tem = negate_expr (arg1)))
11951 && TREE_CODE (tem) == INTEGER_CST
11952 && !TREE_OVERFLOW (tem))
11953 return fold_build2 (TRUTH_ANDIF_EXPR, type,
11954 build2 (GE_EXPR, type,
11955 TREE_OPERAND (arg0, 0), tem),
11956 build2 (LE_EXPR, type,
11957 TREE_OPERAND (arg0, 0), arg1));
11959 /* Convert ABS_EXPR<x> >= 0 to true. */
11960 strict_overflow_p = false;
11961 if (code == GE_EXPR
11962 && (integer_zerop (arg1)
11963 || (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
11964 && real_zerop (arg1)))
11965 && tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p))
11967 if (strict_overflow_p)
11968 fold_overflow_warning (("assuming signed overflow does not occur "
11969 "when simplifying comparison of "
11970 "absolute value and zero"),
11971 WARN_STRICT_OVERFLOW_CONDITIONAL);
11972 return omit_one_operand (type, integer_one_node, arg0);
11975 /* Convert ABS_EXPR<x> < 0 to false. */
11976 strict_overflow_p = false;
11977 if (code == LT_EXPR
11978 && (integer_zerop (arg1) || real_zerop (arg1))
11979 && tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p))
11981 if (strict_overflow_p)
11982 fold_overflow_warning (("assuming signed overflow does not occur "
11983 "when simplifying comparison of "
11984 "absolute value and zero"),
11985 WARN_STRICT_OVERFLOW_CONDITIONAL);
11986 return omit_one_operand (type, integer_zero_node, arg0);
11989 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
11990 and similarly for >= into !=. */
11991 if ((code == LT_EXPR || code == GE_EXPR)
11992 && TYPE_UNSIGNED (TREE_TYPE (arg0))
11993 && TREE_CODE (arg1) == LSHIFT_EXPR
11994 && integer_onep (TREE_OPERAND (arg1, 0)))
11995 return build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
11996 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
11997 TREE_OPERAND (arg1, 1)),
11998 build_int_cst (TREE_TYPE (arg0), 0));
12000 if ((code == LT_EXPR || code == GE_EXPR)
12001 && TYPE_UNSIGNED (TREE_TYPE (arg0))
12002 && (TREE_CODE (arg1) == NOP_EXPR
12003 || TREE_CODE (arg1) == CONVERT_EXPR)
12004 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
12005 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
12007 build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
12008 fold_convert (TREE_TYPE (arg0),
12009 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
12010 TREE_OPERAND (TREE_OPERAND (arg1, 0),
12012 build_int_cst (TREE_TYPE (arg0), 0));
12016 case UNORDERED_EXPR:
12024 if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
12026 t1 = fold_relational_const (code, type, arg0, arg1);
12027 if (t1 != NULL_TREE)
12031 /* If the first operand is NaN, the result is constant. */
12032 if (TREE_CODE (arg0) == REAL_CST
12033 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
12034 && (code != LTGT_EXPR || ! flag_trapping_math))
12036 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
12037 ? integer_zero_node
12038 : integer_one_node;
12039 return omit_one_operand (type, t1, arg1);
12042 /* If the second operand is NaN, the result is constant. */
12043 if (TREE_CODE (arg1) == REAL_CST
12044 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg1))
12045 && (code != LTGT_EXPR || ! flag_trapping_math))
12047 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
12048 ? integer_zero_node
12049 : integer_one_node;
12050 return omit_one_operand (type, t1, arg0);
12053 /* Simplify unordered comparison of something with itself. */
12054 if ((code == UNLE_EXPR || code == UNGE_EXPR || code == UNEQ_EXPR)
12055 && operand_equal_p (arg0, arg1, 0))
12056 return constant_boolean_node (1, type);
12058 if (code == LTGT_EXPR
12059 && !flag_trapping_math
12060 && operand_equal_p (arg0, arg1, 0))
12061 return constant_boolean_node (0, type);
12063 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
12065 tree targ0 = strip_float_extensions (arg0);
12066 tree targ1 = strip_float_extensions (arg1);
12067 tree newtype = TREE_TYPE (targ0);
12069 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
12070 newtype = TREE_TYPE (targ1);
12072 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
12073 return fold_build2 (code, type, fold_convert (newtype, targ0),
12074 fold_convert (newtype, targ1));
12079 case COMPOUND_EXPR:
12080 /* When pedantic, a compound expression can be neither an lvalue
12081 nor an integer constant expression. */
12082 if (TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
12084 /* Don't let (0, 0) be null pointer constant. */
12085 tem = integer_zerop (arg1) ? build1 (NOP_EXPR, type, arg1)
12086 : fold_convert (type, arg1);
12087 return pedantic_non_lvalue (tem);
12090 if ((TREE_CODE (arg0) == REAL_CST
12091 && TREE_CODE (arg1) == REAL_CST)
12092 || (TREE_CODE (arg0) == INTEGER_CST
12093 && TREE_CODE (arg1) == INTEGER_CST))
12094 return build_complex (type, arg0, arg1);
12098 /* An ASSERT_EXPR should never be passed to fold_binary. */
12099 gcc_unreachable ();
12103 } /* switch (code) */
12106 /* Callback for walk_tree, looking for LABEL_EXPR.
12107 Returns tree TP if it is LABEL_EXPR. Otherwise it returns NULL_TREE.
12108 Do not check the sub-tree of GOTO_EXPR. */
12111 contains_label_1 (tree *tp,
12112 int *walk_subtrees,
12113 void *data ATTRIBUTE_UNUSED)
12115 switch (TREE_CODE (*tp))
12120 *walk_subtrees = 0;
12127 /* Checks whether the sub-tree ST contains a label LABEL_EXPR which is
12128 accessible from outside the sub-tree. Returns NULL_TREE if no
12129 addressable label is found. */
12132 contains_label_p (tree st)
12134 return (walk_tree (&st, contains_label_1 , NULL, NULL) != NULL_TREE);
12137 /* Fold a ternary expression of code CODE and type TYPE with operands
12138 OP0, OP1, and OP2. Return the folded expression if folding is
12139 successful. Otherwise, return NULL_TREE. */
12142 fold_ternary (enum tree_code code, tree type, tree op0, tree op1, tree op2)
12145 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
12146 enum tree_code_class kind = TREE_CODE_CLASS (code);
12148 gcc_assert (IS_EXPR_CODE_CLASS (kind)
12149 && TREE_CODE_LENGTH (code) == 3);
12151 /* Strip any conversions that don't change the mode. This is safe
12152 for every expression, except for a comparison expression because
12153 its signedness is derived from its operands. So, in the latter
12154 case, only strip conversions that don't change the signedness.
12156 Note that this is done as an internal manipulation within the
12157 constant folder, in order to find the simplest representation of
12158 the arguments so that their form can be studied. In any cases,
12159 the appropriate type conversions should be put back in the tree
12160 that will get out of the constant folder. */
12175 case COMPONENT_REF:
12176 if (TREE_CODE (arg0) == CONSTRUCTOR
12177 && ! type_contains_placeholder_p (TREE_TYPE (arg0)))
12179 unsigned HOST_WIDE_INT idx;
12181 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (arg0), idx, field, value)
12188 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
12189 so all simple results must be passed through pedantic_non_lvalue. */
12190 if (TREE_CODE (arg0) == INTEGER_CST)
12192 tree unused_op = integer_zerop (arg0) ? op1 : op2;
12193 tem = integer_zerop (arg0) ? op2 : op1;
12194 /* Only optimize constant conditions when the selected branch
12195 has the same type as the COND_EXPR. This avoids optimizing
12196 away "c ? x : throw", where the throw has a void type.
12197 Avoid throwing away that operand which contains label. */
12198 if ((!TREE_SIDE_EFFECTS (unused_op)
12199 || !contains_label_p (unused_op))
12200 && (! VOID_TYPE_P (TREE_TYPE (tem))
12201 || VOID_TYPE_P (type)))
12202 return pedantic_non_lvalue (tem);
12205 if (operand_equal_p (arg1, op2, 0))
12206 return pedantic_omit_one_operand (type, arg1, arg0);
12208 /* If we have A op B ? A : C, we may be able to convert this to a
12209 simpler expression, depending on the operation and the values
12210 of B and C. Signed zeros prevent all of these transformations,
12211 for reasons given above each one.
12213 Also try swapping the arguments and inverting the conditional. */
12214 if (COMPARISON_CLASS_P (arg0)
12215 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
12216 arg1, TREE_OPERAND (arg0, 1))
12217 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
12219 tem = fold_cond_expr_with_comparison (type, arg0, op1, op2);
12224 if (COMPARISON_CLASS_P (arg0)
12225 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
12227 TREE_OPERAND (arg0, 1))
12228 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (op2))))
12230 tem = fold_truth_not_expr (arg0);
12231 if (tem && COMPARISON_CLASS_P (tem))
12233 tem = fold_cond_expr_with_comparison (type, tem, op2, op1);
12239 /* If the second operand is simpler than the third, swap them
12240 since that produces better jump optimization results. */
12241 if (truth_value_p (TREE_CODE (arg0))
12242 && tree_swap_operands_p (op1, op2, false))
12244 /* See if this can be inverted. If it can't, possibly because
12245 it was a floating-point inequality comparison, don't do
12247 tem = fold_truth_not_expr (arg0);
12249 return fold_build3 (code, type, tem, op2, op1);
12252 /* Convert A ? 1 : 0 to simply A. */
12253 if (integer_onep (op1)
12254 && integer_zerop (op2)
12255 /* If we try to convert OP0 to our type, the
12256 call to fold will try to move the conversion inside
12257 a COND, which will recurse. In that case, the COND_EXPR
12258 is probably the best choice, so leave it alone. */
12259 && type == TREE_TYPE (arg0))
12260 return pedantic_non_lvalue (arg0);
12262 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
12263 over COND_EXPR in cases such as floating point comparisons. */
12264 if (integer_zerop (op1)
12265 && integer_onep (op2)
12266 && truth_value_p (TREE_CODE (arg0)))
12267 return pedantic_non_lvalue (fold_convert (type,
12268 invert_truthvalue (arg0)));
12270 /* A < 0 ? <sign bit of A> : 0 is simply (A & <sign bit of A>). */
12271 if (TREE_CODE (arg0) == LT_EXPR
12272 && integer_zerop (TREE_OPERAND (arg0, 1))
12273 && integer_zerop (op2)
12274 && (tem = sign_bit_p (TREE_OPERAND (arg0, 0), arg1)))
12276 /* sign_bit_p only checks ARG1 bits within A's precision.
12277 If <sign bit of A> has wider type than A, bits outside
12278 of A's precision in <sign bit of A> need to be checked.
12279 If they are all 0, this optimization needs to be done
12280 in unsigned A's type, if they are all 1 in signed A's type,
12281 otherwise this can't be done. */
12282 if (TYPE_PRECISION (TREE_TYPE (tem))
12283 < TYPE_PRECISION (TREE_TYPE (arg1))
12284 && TYPE_PRECISION (TREE_TYPE (tem))
12285 < TYPE_PRECISION (type))
12287 unsigned HOST_WIDE_INT mask_lo;
12288 HOST_WIDE_INT mask_hi;
12289 int inner_width, outer_width;
12292 inner_width = TYPE_PRECISION (TREE_TYPE (tem));
12293 outer_width = TYPE_PRECISION (TREE_TYPE (arg1));
12294 if (outer_width > TYPE_PRECISION (type))
12295 outer_width = TYPE_PRECISION (type);
12297 if (outer_width > HOST_BITS_PER_WIDE_INT)
12299 mask_hi = ((unsigned HOST_WIDE_INT) -1
12300 >> (2 * HOST_BITS_PER_WIDE_INT - outer_width));
12306 mask_lo = ((unsigned HOST_WIDE_INT) -1
12307 >> (HOST_BITS_PER_WIDE_INT - outer_width));
12309 if (inner_width > HOST_BITS_PER_WIDE_INT)
12311 mask_hi &= ~((unsigned HOST_WIDE_INT) -1
12312 >> (HOST_BITS_PER_WIDE_INT - inner_width));
12316 mask_lo &= ~((unsigned HOST_WIDE_INT) -1
12317 >> (HOST_BITS_PER_WIDE_INT - inner_width));
12319 if ((TREE_INT_CST_HIGH (arg1) & mask_hi) == mask_hi
12320 && (TREE_INT_CST_LOW (arg1) & mask_lo) == mask_lo)
12322 tem_type = lang_hooks.types.signed_type (TREE_TYPE (tem));
12323 tem = fold_convert (tem_type, tem);
12325 else if ((TREE_INT_CST_HIGH (arg1) & mask_hi) == 0
12326 && (TREE_INT_CST_LOW (arg1) & mask_lo) == 0)
12328 tem_type = lang_hooks.types.unsigned_type (TREE_TYPE (tem));
12329 tem = fold_convert (tem_type, tem);
12336 return fold_convert (type,
12337 fold_build2 (BIT_AND_EXPR,
12338 TREE_TYPE (tem), tem,
12339 fold_convert (TREE_TYPE (tem),
12343 /* (A >> N) & 1 ? (1 << N) : 0 is simply A & (1 << N). A & 1 was
12344 already handled above. */
12345 if (TREE_CODE (arg0) == BIT_AND_EXPR
12346 && integer_onep (TREE_OPERAND (arg0, 1))
12347 && integer_zerop (op2)
12348 && integer_pow2p (arg1))
12350 tree tem = TREE_OPERAND (arg0, 0);
12352 if (TREE_CODE (tem) == RSHIFT_EXPR
12353 && TREE_CODE (TREE_OPERAND (tem, 1)) == INTEGER_CST
12354 && (unsigned HOST_WIDE_INT) tree_log2 (arg1) ==
12355 TREE_INT_CST_LOW (TREE_OPERAND (tem, 1)))
12356 return fold_build2 (BIT_AND_EXPR, type,
12357 TREE_OPERAND (tem, 0), arg1);
12360 /* A & N ? N : 0 is simply A & N if N is a power of two. This
12361 is probably obsolete because the first operand should be a
12362 truth value (that's why we have the two cases above), but let's
12363 leave it in until we can confirm this for all front-ends. */
12364 if (integer_zerop (op2)
12365 && TREE_CODE (arg0) == NE_EXPR
12366 && integer_zerop (TREE_OPERAND (arg0, 1))
12367 && integer_pow2p (arg1)
12368 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
12369 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
12370 arg1, OEP_ONLY_CONST))
12371 return pedantic_non_lvalue (fold_convert (type,
12372 TREE_OPERAND (arg0, 0)));
12374 /* Convert A ? B : 0 into A && B if A and B are truth values. */
12375 if (integer_zerop (op2)
12376 && truth_value_p (TREE_CODE (arg0))
12377 && truth_value_p (TREE_CODE (arg1)))
12378 return fold_build2 (TRUTH_ANDIF_EXPR, type,
12379 fold_convert (type, arg0),
12382 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
12383 if (integer_onep (op2)
12384 && truth_value_p (TREE_CODE (arg0))
12385 && truth_value_p (TREE_CODE (arg1)))
12387 /* Only perform transformation if ARG0 is easily inverted. */
12388 tem = fold_truth_not_expr (arg0);
12390 return fold_build2 (TRUTH_ORIF_EXPR, type,
12391 fold_convert (type, tem),
12395 /* Convert A ? 0 : B into !A && B if A and B are truth values. */
12396 if (integer_zerop (arg1)
12397 && truth_value_p (TREE_CODE (arg0))
12398 && truth_value_p (TREE_CODE (op2)))
12400 /* Only perform transformation if ARG0 is easily inverted. */
12401 tem = fold_truth_not_expr (arg0);
12403 return fold_build2 (TRUTH_ANDIF_EXPR, type,
12404 fold_convert (type, tem),
12408 /* Convert A ? 1 : B into A || B if A and B are truth values. */
12409 if (integer_onep (arg1)
12410 && truth_value_p (TREE_CODE (arg0))
12411 && truth_value_p (TREE_CODE (op2)))
12412 return fold_build2 (TRUTH_ORIF_EXPR, type,
12413 fold_convert (type, arg0),
12419 /* CALL_EXPRs used to be ternary exprs. Catch any mistaken uses
12420 of fold_ternary on them. */
12421 gcc_unreachable ();
12423 case BIT_FIELD_REF:
12424 if (TREE_CODE (arg0) == VECTOR_CST
12425 && type == TREE_TYPE (TREE_TYPE (arg0))
12426 && host_integerp (arg1, 1)
12427 && host_integerp (op2, 1))
12429 unsigned HOST_WIDE_INT width = tree_low_cst (arg1, 1);
12430 unsigned HOST_WIDE_INT idx = tree_low_cst (op2, 1);
12433 && simple_cst_equal (arg1, TYPE_SIZE (type)) == 1
12434 && (idx % width) == 0
12435 && (idx = idx / width)
12436 < TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0)))
12438 tree elements = TREE_VECTOR_CST_ELTS (arg0);
12439 while (idx-- > 0 && elements)
12440 elements = TREE_CHAIN (elements);
12442 return TREE_VALUE (elements);
12444 return fold_convert (type, integer_zero_node);
12451 } /* switch (code) */
12454 /* Perform constant folding and related simplification of EXPR.
12455 The related simplifications include x*1 => x, x*0 => 0, etc.,
12456 and application of the associative law.
12457 NOP_EXPR conversions may be removed freely (as long as we
12458 are careful not to change the type of the overall expression).
12459 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
12460 but we can constant-fold them if they have constant operands. */
12462 #ifdef ENABLE_FOLD_CHECKING
12463 # define fold(x) fold_1 (x)
12464 static tree fold_1 (tree);
12470 const tree t = expr;
12471 enum tree_code code = TREE_CODE (t);
12472 enum tree_code_class kind = TREE_CODE_CLASS (code);
12475 /* Return right away if a constant. */
12476 if (kind == tcc_constant)
12479 /* CALL_EXPR-like objects with variable numbers of operands are
12480 treated specially. */
12481 if (kind == tcc_vl_exp)
12483 if (code == CALL_EXPR)
12485 tem = fold_call_expr (expr, false);
12486 return tem ? tem : expr;
12491 if (IS_EXPR_CODE_CLASS (kind)
12492 || IS_GIMPLE_STMT_CODE_CLASS (kind))
12494 tree type = TREE_TYPE (t);
12495 tree op0, op1, op2;
12497 switch (TREE_CODE_LENGTH (code))
12500 op0 = TREE_OPERAND (t, 0);
12501 tem = fold_unary (code, type, op0);
12502 return tem ? tem : expr;
12504 op0 = TREE_OPERAND (t, 0);
12505 op1 = TREE_OPERAND (t, 1);
12506 tem = fold_binary (code, type, op0, op1);
12507 return tem ? tem : expr;
12509 op0 = TREE_OPERAND (t, 0);
12510 op1 = TREE_OPERAND (t, 1);
12511 op2 = TREE_OPERAND (t, 2);
12512 tem = fold_ternary (code, type, op0, op1, op2);
12513 return tem ? tem : expr;
12522 return fold (DECL_INITIAL (t));
12526 } /* switch (code) */
12529 #ifdef ENABLE_FOLD_CHECKING
12532 static void fold_checksum_tree (tree, struct md5_ctx *, htab_t);
12533 static void fold_check_failed (tree, tree);
12534 void print_fold_checksum (tree);
12536 /* When --enable-checking=fold, compute a digest of expr before
12537 and after actual fold call to see if fold did not accidentally
12538 change original expr. */
12544 struct md5_ctx ctx;
12545 unsigned char checksum_before[16], checksum_after[16];
12548 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
12549 md5_init_ctx (&ctx);
12550 fold_checksum_tree (expr, &ctx, ht);
12551 md5_finish_ctx (&ctx, checksum_before);
12554 ret = fold_1 (expr);
12556 md5_init_ctx (&ctx);
12557 fold_checksum_tree (expr, &ctx, ht);
12558 md5_finish_ctx (&ctx, checksum_after);
12561 if (memcmp (checksum_before, checksum_after, 16))
12562 fold_check_failed (expr, ret);
12568 print_fold_checksum (tree expr)
12570 struct md5_ctx ctx;
12571 unsigned char checksum[16], cnt;
12574 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
12575 md5_init_ctx (&ctx);
12576 fold_checksum_tree (expr, &ctx, ht);
12577 md5_finish_ctx (&ctx, checksum);
12579 for (cnt = 0; cnt < 16; ++cnt)
12580 fprintf (stderr, "%02x", checksum[cnt]);
12581 putc ('\n', stderr);
12585 fold_check_failed (tree expr ATTRIBUTE_UNUSED, tree ret ATTRIBUTE_UNUSED)
12587 internal_error ("fold check: original tree changed by fold");
12591 fold_checksum_tree (tree expr, struct md5_ctx *ctx, htab_t ht)
12594 enum tree_code code;
12595 struct tree_function_decl buf;
12600 gcc_assert ((sizeof (struct tree_exp) + 5 * sizeof (tree)
12601 <= sizeof (struct tree_function_decl))
12602 && sizeof (struct tree_type) <= sizeof (struct tree_function_decl));
12605 slot = htab_find_slot (ht, expr, INSERT);
12609 code = TREE_CODE (expr);
12610 if (TREE_CODE_CLASS (code) == tcc_declaration
12611 && DECL_ASSEMBLER_NAME_SET_P (expr))
12613 /* Allow DECL_ASSEMBLER_NAME to be modified. */
12614 memcpy ((char *) &buf, expr, tree_size (expr));
12615 expr = (tree) &buf;
12616 SET_DECL_ASSEMBLER_NAME (expr, NULL);
12618 else if (TREE_CODE_CLASS (code) == tcc_type
12619 && (TYPE_POINTER_TO (expr) || TYPE_REFERENCE_TO (expr)
12620 || TYPE_CACHED_VALUES_P (expr)
12621 || TYPE_CONTAINS_PLACEHOLDER_INTERNAL (expr)))
12623 /* Allow these fields to be modified. */
12624 memcpy ((char *) &buf, expr, tree_size (expr));
12625 expr = (tree) &buf;
12626 TYPE_CONTAINS_PLACEHOLDER_INTERNAL (expr) = 0;
12627 TYPE_POINTER_TO (expr) = NULL;
12628 TYPE_REFERENCE_TO (expr) = NULL;
12629 if (TYPE_CACHED_VALUES_P (expr))
12631 TYPE_CACHED_VALUES_P (expr) = 0;
12632 TYPE_CACHED_VALUES (expr) = NULL;
12635 md5_process_bytes (expr, tree_size (expr), ctx);
12636 fold_checksum_tree (TREE_TYPE (expr), ctx, ht);
12637 if (TREE_CODE_CLASS (code) != tcc_type
12638 && TREE_CODE_CLASS (code) != tcc_declaration
12639 && code != TREE_LIST)
12640 fold_checksum_tree (TREE_CHAIN (expr), ctx, ht);
12641 switch (TREE_CODE_CLASS (code))
12647 md5_process_bytes (TREE_STRING_POINTER (expr),
12648 TREE_STRING_LENGTH (expr), ctx);
12651 fold_checksum_tree (TREE_REALPART (expr), ctx, ht);
12652 fold_checksum_tree (TREE_IMAGPART (expr), ctx, ht);
12655 fold_checksum_tree (TREE_VECTOR_CST_ELTS (expr), ctx, ht);
12661 case tcc_exceptional:
12665 fold_checksum_tree (TREE_PURPOSE (expr), ctx, ht);
12666 fold_checksum_tree (TREE_VALUE (expr), ctx, ht);
12667 expr = TREE_CHAIN (expr);
12668 goto recursive_label;
12671 for (i = 0; i < TREE_VEC_LENGTH (expr); ++i)
12672 fold_checksum_tree (TREE_VEC_ELT (expr, i), ctx, ht);
12678 case tcc_expression:
12679 case tcc_reference:
12680 case tcc_comparison:
12683 case tcc_statement:
12685 len = TREE_OPERAND_LENGTH (expr);
12686 for (i = 0; i < len; ++i)
12687 fold_checksum_tree (TREE_OPERAND (expr, i), ctx, ht);
12689 case tcc_declaration:
12690 fold_checksum_tree (DECL_NAME (expr), ctx, ht);
12691 fold_checksum_tree (DECL_CONTEXT (expr), ctx, ht);
12692 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_COMMON))
12694 fold_checksum_tree (DECL_SIZE (expr), ctx, ht);
12695 fold_checksum_tree (DECL_SIZE_UNIT (expr), ctx, ht);
12696 fold_checksum_tree (DECL_INITIAL (expr), ctx, ht);
12697 fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr), ctx, ht);
12698 fold_checksum_tree (DECL_ATTRIBUTES (expr), ctx, ht);
12700 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_WITH_VIS))
12701 fold_checksum_tree (DECL_SECTION_NAME (expr), ctx, ht);
12703 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_NON_COMMON))
12705 fold_checksum_tree (DECL_VINDEX (expr), ctx, ht);
12706 fold_checksum_tree (DECL_RESULT_FLD (expr), ctx, ht);
12707 fold_checksum_tree (DECL_ARGUMENT_FLD (expr), ctx, ht);
12711 if (TREE_CODE (expr) == ENUMERAL_TYPE)
12712 fold_checksum_tree (TYPE_VALUES (expr), ctx, ht);
12713 fold_checksum_tree (TYPE_SIZE (expr), ctx, ht);
12714 fold_checksum_tree (TYPE_SIZE_UNIT (expr), ctx, ht);
12715 fold_checksum_tree (TYPE_ATTRIBUTES (expr), ctx, ht);
12716 fold_checksum_tree (TYPE_NAME (expr), ctx, ht);
12717 if (INTEGRAL_TYPE_P (expr)
12718 || SCALAR_FLOAT_TYPE_P (expr))
12720 fold_checksum_tree (TYPE_MIN_VALUE (expr), ctx, ht);
12721 fold_checksum_tree (TYPE_MAX_VALUE (expr), ctx, ht);
12723 fold_checksum_tree (TYPE_MAIN_VARIANT (expr), ctx, ht);
12724 if (TREE_CODE (expr) == RECORD_TYPE
12725 || TREE_CODE (expr) == UNION_TYPE
12726 || TREE_CODE (expr) == QUAL_UNION_TYPE)
12727 fold_checksum_tree (TYPE_BINFO (expr), ctx, ht);
12728 fold_checksum_tree (TYPE_CONTEXT (expr), ctx, ht);
12737 /* Fold a unary tree expression with code CODE of type TYPE with an
12738 operand OP0. Return a folded expression if successful. Otherwise,
12739 return a tree expression with code CODE of type TYPE with an
12743 fold_build1_stat (enum tree_code code, tree type, tree op0 MEM_STAT_DECL)
12746 #ifdef ENABLE_FOLD_CHECKING
12747 unsigned char checksum_before[16], checksum_after[16];
12748 struct md5_ctx ctx;
12751 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
12752 md5_init_ctx (&ctx);
12753 fold_checksum_tree (op0, &ctx, ht);
12754 md5_finish_ctx (&ctx, checksum_before);
12758 tem = fold_unary (code, type, op0);
12760 tem = build1_stat (code, type, op0 PASS_MEM_STAT);
12762 #ifdef ENABLE_FOLD_CHECKING
12763 md5_init_ctx (&ctx);
12764 fold_checksum_tree (op0, &ctx, ht);
12765 md5_finish_ctx (&ctx, checksum_after);
12768 if (memcmp (checksum_before, checksum_after, 16))
12769 fold_check_failed (op0, tem);
12774 /* Fold a binary tree expression with code CODE of type TYPE with
12775 operands OP0 and OP1. Return a folded expression if successful.
12776 Otherwise, return a tree expression with code CODE of type TYPE
12777 with operands OP0 and OP1. */
12780 fold_build2_stat (enum tree_code code, tree type, tree op0, tree op1
12784 #ifdef ENABLE_FOLD_CHECKING
12785 unsigned char checksum_before_op0[16],
12786 checksum_before_op1[16],
12787 checksum_after_op0[16],
12788 checksum_after_op1[16];
12789 struct md5_ctx ctx;
12792 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
12793 md5_init_ctx (&ctx);
12794 fold_checksum_tree (op0, &ctx, ht);
12795 md5_finish_ctx (&ctx, checksum_before_op0);
12798 md5_init_ctx (&ctx);
12799 fold_checksum_tree (op1, &ctx, ht);
12800 md5_finish_ctx (&ctx, checksum_before_op1);
12804 tem = fold_binary (code, type, op0, op1);
12806 tem = build2_stat (code, type, op0, op1 PASS_MEM_STAT);
12808 #ifdef ENABLE_FOLD_CHECKING
12809 md5_init_ctx (&ctx);
12810 fold_checksum_tree (op0, &ctx, ht);
12811 md5_finish_ctx (&ctx, checksum_after_op0);
12814 if (memcmp (checksum_before_op0, checksum_after_op0, 16))
12815 fold_check_failed (op0, tem);
12817 md5_init_ctx (&ctx);
12818 fold_checksum_tree (op1, &ctx, ht);
12819 md5_finish_ctx (&ctx, checksum_after_op1);
12822 if (memcmp (checksum_before_op1, checksum_after_op1, 16))
12823 fold_check_failed (op1, tem);
12828 /* Fold a ternary tree expression with code CODE of type TYPE with
12829 operands OP0, OP1, and OP2. Return a folded expression if
12830 successful. Otherwise, return a tree expression with code CODE of
12831 type TYPE with operands OP0, OP1, and OP2. */
12834 fold_build3_stat (enum tree_code code, tree type, tree op0, tree op1, tree op2
12838 #ifdef ENABLE_FOLD_CHECKING
12839 unsigned char checksum_before_op0[16],
12840 checksum_before_op1[16],
12841 checksum_before_op2[16],
12842 checksum_after_op0[16],
12843 checksum_after_op1[16],
12844 checksum_after_op2[16];
12845 struct md5_ctx ctx;
12848 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
12849 md5_init_ctx (&ctx);
12850 fold_checksum_tree (op0, &ctx, ht);
12851 md5_finish_ctx (&ctx, checksum_before_op0);
12854 md5_init_ctx (&ctx);
12855 fold_checksum_tree (op1, &ctx, ht);
12856 md5_finish_ctx (&ctx, checksum_before_op1);
12859 md5_init_ctx (&ctx);
12860 fold_checksum_tree (op2, &ctx, ht);
12861 md5_finish_ctx (&ctx, checksum_before_op2);
12865 gcc_assert (TREE_CODE_CLASS (code) != tcc_vl_exp);
12866 tem = fold_ternary (code, type, op0, op1, op2);
12868 tem = build3_stat (code, type, op0, op1, op2 PASS_MEM_STAT);
12870 #ifdef ENABLE_FOLD_CHECKING
12871 md5_init_ctx (&ctx);
12872 fold_checksum_tree (op0, &ctx, ht);
12873 md5_finish_ctx (&ctx, checksum_after_op0);
12876 if (memcmp (checksum_before_op0, checksum_after_op0, 16))
12877 fold_check_failed (op0, tem);
12879 md5_init_ctx (&ctx);
12880 fold_checksum_tree (op1, &ctx, ht);
12881 md5_finish_ctx (&ctx, checksum_after_op1);
12884 if (memcmp (checksum_before_op1, checksum_after_op1, 16))
12885 fold_check_failed (op1, tem);
12887 md5_init_ctx (&ctx);
12888 fold_checksum_tree (op2, &ctx, ht);
12889 md5_finish_ctx (&ctx, checksum_after_op2);
12892 if (memcmp (checksum_before_op2, checksum_after_op2, 16))
12893 fold_check_failed (op2, tem);
12898 /* Fold a CALL_EXPR expression of type TYPE with operands FN and NARGS
12899 arguments in ARGARRAY, and a null static chain.
12900 Return a folded expression if successful. Otherwise, return a CALL_EXPR
12901 of type TYPE from the given operands as constructed by build_call_array. */
12904 fold_build_call_array (tree type, tree fn, int nargs, tree *argarray)
12907 #ifdef ENABLE_FOLD_CHECKING
12908 unsigned char checksum_before_fn[16],
12909 checksum_before_arglist[16],
12910 checksum_after_fn[16],
12911 checksum_after_arglist[16];
12912 struct md5_ctx ctx;
12916 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
12917 md5_init_ctx (&ctx);
12918 fold_checksum_tree (fn, &ctx, ht);
12919 md5_finish_ctx (&ctx, checksum_before_fn);
12922 md5_init_ctx (&ctx);
12923 for (i = 0; i < nargs; i++)
12924 fold_checksum_tree (argarray[i], &ctx, ht);
12925 md5_finish_ctx (&ctx, checksum_before_arglist);
12929 tem = fold_builtin_call_array (type, fn, nargs, argarray);
12931 #ifdef ENABLE_FOLD_CHECKING
12932 md5_init_ctx (&ctx);
12933 fold_checksum_tree (fn, &ctx, ht);
12934 md5_finish_ctx (&ctx, checksum_after_fn);
12937 if (memcmp (checksum_before_fn, checksum_after_fn, 16))
12938 fold_check_failed (fn, tem);
12940 md5_init_ctx (&ctx);
12941 for (i = 0; i < nargs; i++)
12942 fold_checksum_tree (argarray[i], &ctx, ht);
12943 md5_finish_ctx (&ctx, checksum_after_arglist);
12946 if (memcmp (checksum_before_arglist, checksum_after_arglist, 16))
12947 fold_check_failed (NULL_TREE, tem);
12952 /* Perform constant folding and related simplification of initializer
12953 expression EXPR. These behave identically to "fold_buildN" but ignore
12954 potential run-time traps and exceptions that fold must preserve. */
12956 #define START_FOLD_INIT \
12957 int saved_signaling_nans = flag_signaling_nans;\
12958 int saved_trapping_math = flag_trapping_math;\
12959 int saved_rounding_math = flag_rounding_math;\
12960 int saved_trapv = flag_trapv;\
12961 int saved_folding_initializer = folding_initializer;\
12962 flag_signaling_nans = 0;\
12963 flag_trapping_math = 0;\
12964 flag_rounding_math = 0;\
12966 folding_initializer = 1;
12968 #define END_FOLD_INIT \
12969 flag_signaling_nans = saved_signaling_nans;\
12970 flag_trapping_math = saved_trapping_math;\
12971 flag_rounding_math = saved_rounding_math;\
12972 flag_trapv = saved_trapv;\
12973 folding_initializer = saved_folding_initializer;
12976 fold_build1_initializer (enum tree_code code, tree type, tree op)
12981 result = fold_build1 (code, type, op);
12988 fold_build2_initializer (enum tree_code code, tree type, tree op0, tree op1)
12993 result = fold_build2 (code, type, op0, op1);
13000 fold_build3_initializer (enum tree_code code, tree type, tree op0, tree op1,
13006 result = fold_build3 (code, type, op0, op1, op2);
13013 fold_build_call_array_initializer (tree type, tree fn,
13014 int nargs, tree *argarray)
13019 result = fold_build_call_array (type, fn, nargs, argarray);
13025 #undef START_FOLD_INIT
13026 #undef END_FOLD_INIT
13028 /* Determine if first argument is a multiple of second argument. Return 0 if
13029 it is not, or we cannot easily determined it to be.
13031 An example of the sort of thing we care about (at this point; this routine
13032 could surely be made more general, and expanded to do what the *_DIV_EXPR's
13033 fold cases do now) is discovering that
13035 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
13041 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
13043 This code also handles discovering that
13045 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
13047 is a multiple of 8 so we don't have to worry about dealing with a
13048 possible remainder.
13050 Note that we *look* inside a SAVE_EXPR only to determine how it was
13051 calculated; it is not safe for fold to do much of anything else with the
13052 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
13053 at run time. For example, the latter example above *cannot* be implemented
13054 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
13055 evaluation time of the original SAVE_EXPR is not necessarily the same at
13056 the time the new expression is evaluated. The only optimization of this
13057 sort that would be valid is changing
13059 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
13063 SAVE_EXPR (I) * SAVE_EXPR (J)
13065 (where the same SAVE_EXPR (J) is used in the original and the
13066 transformed version). */
13069 multiple_of_p (tree type, tree top, tree bottom)
13071 if (operand_equal_p (top, bottom, 0))
13074 if (TREE_CODE (type) != INTEGER_TYPE)
13077 switch (TREE_CODE (top))
13080 /* Bitwise and provides a power of two multiple. If the mask is
13081 a multiple of BOTTOM then TOP is a multiple of BOTTOM. */
13082 if (!integer_pow2p (bottom))
13087 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
13088 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
13092 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
13093 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
13096 if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
13100 op1 = TREE_OPERAND (top, 1);
13101 /* const_binop may not detect overflow correctly,
13102 so check for it explicitly here. */
13103 if (TYPE_PRECISION (TREE_TYPE (size_one_node))
13104 > TREE_INT_CST_LOW (op1)
13105 && TREE_INT_CST_HIGH (op1) == 0
13106 && 0 != (t1 = fold_convert (type,
13107 const_binop (LSHIFT_EXPR,
13110 && !TREE_OVERFLOW (t1))
13111 return multiple_of_p (type, t1, bottom);
13116 /* Can't handle conversions from non-integral or wider integral type. */
13117 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
13118 || (TYPE_PRECISION (type)
13119 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
13122 /* .. fall through ... */
13125 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
13128 if (TREE_CODE (bottom) != INTEGER_CST
13129 || (TYPE_UNSIGNED (type)
13130 && (tree_int_cst_sgn (top) < 0
13131 || tree_int_cst_sgn (bottom) < 0)))
13133 return integer_zerop (int_const_binop (TRUNC_MOD_EXPR,
13141 /* Return true if `t' is known to be non-negative. If the return
13142 value is based on the assumption that signed overflow is undefined,
13143 set *STRICT_OVERFLOW_P to true; otherwise, don't change
13144 *STRICT_OVERFLOW_P. */
13147 tree_expr_nonnegative_warnv_p (tree t, bool *strict_overflow_p)
13149 if (t == error_mark_node)
13152 if (TYPE_UNSIGNED (TREE_TYPE (t)))
13155 switch (TREE_CODE (t))
13158 /* Query VRP to see if it has recorded any information about
13159 the range of this object. */
13160 return ssa_name_nonnegative_p (t);
13163 /* We can't return 1 if flag_wrapv is set because
13164 ABS_EXPR<INT_MIN> = INT_MIN. */
13165 if (!INTEGRAL_TYPE_P (TREE_TYPE (t)))
13167 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (t)))
13169 *strict_overflow_p = true;
13175 return tree_int_cst_sgn (t) >= 0;
13178 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
13181 if (FLOAT_TYPE_P (TREE_TYPE (t)))
13182 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
13184 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
13185 strict_overflow_p));
13187 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
13188 both unsigned and at least 2 bits shorter than the result. */
13189 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
13190 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
13191 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
13193 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
13194 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
13195 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
13196 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
13198 unsigned int prec = MAX (TYPE_PRECISION (inner1),
13199 TYPE_PRECISION (inner2)) + 1;
13200 return prec < TYPE_PRECISION (TREE_TYPE (t));
13206 if (FLOAT_TYPE_P (TREE_TYPE (t)))
13208 /* x * x for floating point x is always non-negative. */
13209 if (operand_equal_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1), 0))
13211 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
13213 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
13214 strict_overflow_p));
13217 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
13218 both unsigned and their total bits is shorter than the result. */
13219 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
13220 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
13221 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
13223 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
13224 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
13225 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
13226 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
13227 return TYPE_PRECISION (inner1) + TYPE_PRECISION (inner2)
13228 < TYPE_PRECISION (TREE_TYPE (t));
13234 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
13236 || tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
13237 strict_overflow_p));
13243 case TRUNC_DIV_EXPR:
13244 case CEIL_DIV_EXPR:
13245 case FLOOR_DIV_EXPR:
13246 case ROUND_DIV_EXPR:
13247 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
13249 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
13250 strict_overflow_p));
13252 case TRUNC_MOD_EXPR:
13253 case CEIL_MOD_EXPR:
13254 case FLOOR_MOD_EXPR:
13255 case ROUND_MOD_EXPR:
13257 case NON_LVALUE_EXPR:
13259 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
13260 strict_overflow_p);
13262 case COMPOUND_EXPR:
13264 case GIMPLE_MODIFY_STMT:
13265 return tree_expr_nonnegative_warnv_p (GENERIC_TREE_OPERAND (t, 1),
13266 strict_overflow_p);
13269 return tree_expr_nonnegative_warnv_p (expr_last (TREE_OPERAND (t, 1)),
13270 strict_overflow_p);
13273 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
13275 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 2),
13276 strict_overflow_p));
13280 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
13281 tree outer_type = TREE_TYPE (t);
13283 if (TREE_CODE (outer_type) == REAL_TYPE)
13285 if (TREE_CODE (inner_type) == REAL_TYPE)
13286 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
13287 strict_overflow_p);
13288 if (TREE_CODE (inner_type) == INTEGER_TYPE)
13290 if (TYPE_UNSIGNED (inner_type))
13292 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
13293 strict_overflow_p);
13296 else if (TREE_CODE (outer_type) == INTEGER_TYPE)
13298 if (TREE_CODE (inner_type) == REAL_TYPE)
13299 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t,0),
13300 strict_overflow_p);
13301 if (TREE_CODE (inner_type) == INTEGER_TYPE)
13302 return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
13303 && TYPE_UNSIGNED (inner_type);
13310 tree temp = TARGET_EXPR_SLOT (t);
13311 t = TARGET_EXPR_INITIAL (t);
13313 /* If the initializer is non-void, then it's a normal expression
13314 that will be assigned to the slot. */
13315 if (!VOID_TYPE_P (t))
13316 return tree_expr_nonnegative_warnv_p (t, strict_overflow_p);
13318 /* Otherwise, the initializer sets the slot in some way. One common
13319 way is an assignment statement at the end of the initializer. */
13322 if (TREE_CODE (t) == BIND_EXPR)
13323 t = expr_last (BIND_EXPR_BODY (t));
13324 else if (TREE_CODE (t) == TRY_FINALLY_EXPR
13325 || TREE_CODE (t) == TRY_CATCH_EXPR)
13326 t = expr_last (TREE_OPERAND (t, 0));
13327 else if (TREE_CODE (t) == STATEMENT_LIST)
13332 if ((TREE_CODE (t) == MODIFY_EXPR
13333 || TREE_CODE (t) == GIMPLE_MODIFY_STMT)
13334 && GENERIC_TREE_OPERAND (t, 0) == temp)
13335 return tree_expr_nonnegative_warnv_p (GENERIC_TREE_OPERAND (t, 1),
13336 strict_overflow_p);
13343 tree fndecl = get_callee_fndecl (t);
13344 if (fndecl && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
13345 switch (DECL_FUNCTION_CODE (fndecl))
13347 CASE_FLT_FN (BUILT_IN_ACOS):
13348 CASE_FLT_FN (BUILT_IN_ACOSH):
13349 CASE_FLT_FN (BUILT_IN_CABS):
13350 CASE_FLT_FN (BUILT_IN_COSH):
13351 CASE_FLT_FN (BUILT_IN_ERFC):
13352 CASE_FLT_FN (BUILT_IN_EXP):
13353 CASE_FLT_FN (BUILT_IN_EXP10):
13354 CASE_FLT_FN (BUILT_IN_EXP2):
13355 CASE_FLT_FN (BUILT_IN_FABS):
13356 CASE_FLT_FN (BUILT_IN_FDIM):
13357 CASE_FLT_FN (BUILT_IN_HYPOT):
13358 CASE_FLT_FN (BUILT_IN_POW10):
13359 CASE_INT_FN (BUILT_IN_FFS):
13360 CASE_INT_FN (BUILT_IN_PARITY):
13361 CASE_INT_FN (BUILT_IN_POPCOUNT):
13362 case BUILT_IN_BSWAP32:
13363 case BUILT_IN_BSWAP64:
13367 CASE_FLT_FN (BUILT_IN_SQRT):
13368 /* sqrt(-0.0) is -0.0. */
13369 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (t))))
13371 return tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 0),
13372 strict_overflow_p);
13374 CASE_FLT_FN (BUILT_IN_ASINH):
13375 CASE_FLT_FN (BUILT_IN_ATAN):
13376 CASE_FLT_FN (BUILT_IN_ATANH):
13377 CASE_FLT_FN (BUILT_IN_CBRT):
13378 CASE_FLT_FN (BUILT_IN_CEIL):
13379 CASE_FLT_FN (BUILT_IN_ERF):
13380 CASE_FLT_FN (BUILT_IN_EXPM1):
13381 CASE_FLT_FN (BUILT_IN_FLOOR):
13382 CASE_FLT_FN (BUILT_IN_FMOD):
13383 CASE_FLT_FN (BUILT_IN_FREXP):
13384 CASE_FLT_FN (BUILT_IN_LCEIL):
13385 CASE_FLT_FN (BUILT_IN_LDEXP):
13386 CASE_FLT_FN (BUILT_IN_LFLOOR):
13387 CASE_FLT_FN (BUILT_IN_LLCEIL):
13388 CASE_FLT_FN (BUILT_IN_LLFLOOR):
13389 CASE_FLT_FN (BUILT_IN_LLRINT):
13390 CASE_FLT_FN (BUILT_IN_LLROUND):
13391 CASE_FLT_FN (BUILT_IN_LRINT):
13392 CASE_FLT_FN (BUILT_IN_LROUND):
13393 CASE_FLT_FN (BUILT_IN_MODF):
13394 CASE_FLT_FN (BUILT_IN_NEARBYINT):
13395 CASE_FLT_FN (BUILT_IN_RINT):
13396 CASE_FLT_FN (BUILT_IN_ROUND):
13397 CASE_FLT_FN (BUILT_IN_SCALB):
13398 CASE_FLT_FN (BUILT_IN_SCALBLN):
13399 CASE_FLT_FN (BUILT_IN_SCALBN):
13400 CASE_FLT_FN (BUILT_IN_SIGNBIT):
13401 CASE_FLT_FN (BUILT_IN_SIGNIFICAND):
13402 CASE_FLT_FN (BUILT_IN_SINH):
13403 CASE_FLT_FN (BUILT_IN_TANH):
13404 CASE_FLT_FN (BUILT_IN_TRUNC):
13405 /* True if the 1st argument is nonnegative. */
13406 return tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 0),
13407 strict_overflow_p);
13409 CASE_FLT_FN (BUILT_IN_FMAX):
13410 /* True if the 1st OR 2nd arguments are nonnegative. */
13411 return (tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 0),
13413 || (tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 1),
13414 strict_overflow_p)));
13416 CASE_FLT_FN (BUILT_IN_FMIN):
13417 /* True if the 1st AND 2nd arguments are nonnegative. */
13418 return (tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 0),
13420 && (tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 1),
13421 strict_overflow_p)));
13423 CASE_FLT_FN (BUILT_IN_COPYSIGN):
13424 /* True if the 2nd argument is nonnegative. */
13425 return tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 1),
13426 strict_overflow_p);
13428 CASE_FLT_FN (BUILT_IN_POWI):
13429 /* True if the 1st argument is nonnegative or the second
13430 argument is an even integer. */
13431 if (TREE_CODE (CALL_EXPR_ARG (t, 1)) == INTEGER_CST)
13433 tree arg1 = CALL_EXPR_ARG (t, 1);
13434 if ((TREE_INT_CST_LOW (arg1) & 1) == 0)
13437 return tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 0),
13438 strict_overflow_p);
13440 CASE_FLT_FN (BUILT_IN_POW):
13441 /* True if the 1st argument is nonnegative or the second
13442 argument is an even integer valued real. */
13443 if (TREE_CODE (CALL_EXPR_ARG (t, 1)) == REAL_CST)
13448 c = TREE_REAL_CST (CALL_EXPR_ARG (t, 1));
13449 n = real_to_integer (&c);
13452 REAL_VALUE_TYPE cint;
13453 real_from_integer (&cint, VOIDmode, n,
13454 n < 0 ? -1 : 0, 0);
13455 if (real_identical (&c, &cint))
13459 return tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 0),
13460 strict_overflow_p);
13467 /* ... fall through ... */
13470 if (truth_value_p (TREE_CODE (t)))
13471 /* Truth values evaluate to 0 or 1, which is nonnegative. */
13475 /* We don't know sign of `t', so be conservative and return false. */
13479 /* Return true if `t' is known to be non-negative. Handle warnings
13480 about undefined signed overflow. */
13483 tree_expr_nonnegative_p (tree t)
13485 bool ret, strict_overflow_p;
13487 strict_overflow_p = false;
13488 ret = tree_expr_nonnegative_warnv_p (t, &strict_overflow_p);
13489 if (strict_overflow_p)
13490 fold_overflow_warning (("assuming signed overflow does not occur when "
13491 "determining that expression is always "
13493 WARN_STRICT_OVERFLOW_MISC);
13497 /* Return true when T is an address and is known to be nonzero.
13498 For floating point we further ensure that T is not denormal.
13499 Similar logic is present in nonzero_address in rtlanal.h.
13501 If the return value is based on the assumption that signed overflow
13502 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
13503 change *STRICT_OVERFLOW_P. */
13506 tree_expr_nonzero_warnv_p (tree t, bool *strict_overflow_p)
13508 tree type = TREE_TYPE (t);
13509 bool sub_strict_overflow_p;
13511 /* Doing something useful for floating point would need more work. */
13512 if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
13515 switch (TREE_CODE (t))
13518 /* Query VRP to see if it has recorded any information about
13519 the range of this object. */
13520 return ssa_name_nonzero_p (t);
13523 return tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
13524 strict_overflow_p);
13527 return !integer_zerop (t);
13530 if (TYPE_OVERFLOW_UNDEFINED (type))
13532 /* With the presence of negative values it is hard
13533 to say something. */
13534 sub_strict_overflow_p = false;
13535 if (!tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
13536 &sub_strict_overflow_p)
13537 || !tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
13538 &sub_strict_overflow_p))
13540 /* One of operands must be positive and the other non-negative. */
13541 /* We don't set *STRICT_OVERFLOW_P here: even if this value
13542 overflows, on a twos-complement machine the sum of two
13543 nonnegative numbers can never be zero. */
13544 return (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
13546 || tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
13547 strict_overflow_p));
13552 if (TYPE_OVERFLOW_UNDEFINED (type))
13554 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
13556 && tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
13557 strict_overflow_p))
13559 *strict_overflow_p = true;
13567 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
13568 tree outer_type = TREE_TYPE (t);
13570 return (TYPE_PRECISION (outer_type) >= TYPE_PRECISION (inner_type)
13571 && tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
13572 strict_overflow_p));
13578 tree base = get_base_address (TREE_OPERAND (t, 0));
13583 /* Weak declarations may link to NULL. */
13584 if (VAR_OR_FUNCTION_DECL_P (base))
13585 return !DECL_WEAK (base);
13587 /* Constants are never weak. */
13588 if (CONSTANT_CLASS_P (base))
13595 sub_strict_overflow_p = false;
13596 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
13597 &sub_strict_overflow_p)
13598 && tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 2),
13599 &sub_strict_overflow_p))
13601 if (sub_strict_overflow_p)
13602 *strict_overflow_p = true;
13608 sub_strict_overflow_p = false;
13609 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
13610 &sub_strict_overflow_p)
13611 && tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
13612 &sub_strict_overflow_p))
13614 if (sub_strict_overflow_p)
13615 *strict_overflow_p = true;
13620 sub_strict_overflow_p = false;
13621 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
13622 &sub_strict_overflow_p))
13624 if (sub_strict_overflow_p)
13625 *strict_overflow_p = true;
13627 /* When both operands are nonzero, then MAX must be too. */
13628 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
13629 strict_overflow_p))
13632 /* MAX where operand 0 is positive is positive. */
13633 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
13634 strict_overflow_p);
13636 /* MAX where operand 1 is positive is positive. */
13637 else if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
13638 &sub_strict_overflow_p)
13639 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
13640 &sub_strict_overflow_p))
13642 if (sub_strict_overflow_p)
13643 *strict_overflow_p = true;
13648 case COMPOUND_EXPR:
13650 case GIMPLE_MODIFY_STMT:
13652 return tree_expr_nonzero_warnv_p (GENERIC_TREE_OPERAND (t, 1),
13653 strict_overflow_p);
13656 case NON_LVALUE_EXPR:
13657 return tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
13658 strict_overflow_p);
13661 return (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
13663 || tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
13664 strict_overflow_p));
13667 return alloca_call_p (t);
13675 /* Return true when T is an address and is known to be nonzero.
13676 Handle warnings about undefined signed overflow. */
13679 tree_expr_nonzero_p (tree t)
13681 bool ret, strict_overflow_p;
13683 strict_overflow_p = false;
13684 ret = tree_expr_nonzero_warnv_p (t, &strict_overflow_p);
13685 if (strict_overflow_p)
13686 fold_overflow_warning (("assuming signed overflow does not occur when "
13687 "determining that expression is always "
13689 WARN_STRICT_OVERFLOW_MISC);
13693 /* Given the components of a binary expression CODE, TYPE, OP0 and OP1,
13694 attempt to fold the expression to a constant without modifying TYPE,
13697 If the expression could be simplified to a constant, then return
13698 the constant. If the expression would not be simplified to a
13699 constant, then return NULL_TREE. */
13702 fold_binary_to_constant (enum tree_code code, tree type, tree op0, tree op1)
13704 tree tem = fold_binary (code, type, op0, op1);
13705 return (tem && TREE_CONSTANT (tem)) ? tem : NULL_TREE;
13708 /* Given the components of a unary expression CODE, TYPE and OP0,
13709 attempt to fold the expression to a constant without modifying
13712 If the expression could be simplified to a constant, then return
13713 the constant. If the expression would not be simplified to a
13714 constant, then return NULL_TREE. */
13717 fold_unary_to_constant (enum tree_code code, tree type, tree op0)
13719 tree tem = fold_unary (code, type, op0);
13720 return (tem && TREE_CONSTANT (tem)) ? tem : NULL_TREE;
13723 /* If EXP represents referencing an element in a constant string
13724 (either via pointer arithmetic or array indexing), return the
13725 tree representing the value accessed, otherwise return NULL. */
13728 fold_read_from_constant_string (tree exp)
13730 if ((TREE_CODE (exp) == INDIRECT_REF
13731 || TREE_CODE (exp) == ARRAY_REF)
13732 && TREE_CODE (TREE_TYPE (exp)) == INTEGER_TYPE)
13734 tree exp1 = TREE_OPERAND (exp, 0);
13738 if (TREE_CODE (exp) == INDIRECT_REF)
13739 string = string_constant (exp1, &index);
13742 tree low_bound = array_ref_low_bound (exp);
13743 index = fold_convert (sizetype, TREE_OPERAND (exp, 1));
13745 /* Optimize the special-case of a zero lower bound.
13747 We convert the low_bound to sizetype to avoid some problems
13748 with constant folding. (E.g. suppose the lower bound is 1,
13749 and its mode is QI. Without the conversion,l (ARRAY
13750 +(INDEX-(unsigned char)1)) becomes ((ARRAY+(-(unsigned char)1))
13751 +INDEX), which becomes (ARRAY+255+INDEX). Opps!) */
13752 if (! integer_zerop (low_bound))
13753 index = size_diffop (index, fold_convert (sizetype, low_bound));
13759 && TYPE_MODE (TREE_TYPE (exp)) == TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))
13760 && TREE_CODE (string) == STRING_CST
13761 && TREE_CODE (index) == INTEGER_CST
13762 && compare_tree_int (index, TREE_STRING_LENGTH (string)) < 0
13763 && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (string))))
13765 && (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))) == 1))
13766 return fold_convert (TREE_TYPE (exp),
13767 build_int_cst (NULL_TREE,
13768 (TREE_STRING_POINTER (string)
13769 [TREE_INT_CST_LOW (index)])));
13774 /* Return the tree for neg (ARG0) when ARG0 is known to be either
13775 an integer constant or real constant.
13777 TYPE is the type of the result. */
13780 fold_negate_const (tree arg0, tree type)
13782 tree t = NULL_TREE;
13784 switch (TREE_CODE (arg0))
13788 unsigned HOST_WIDE_INT low;
13789 HOST_WIDE_INT high;
13790 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
13791 TREE_INT_CST_HIGH (arg0),
13793 t = force_fit_type_double (type, low, high, 1,
13794 (overflow | TREE_OVERFLOW (arg0))
13795 && !TYPE_UNSIGNED (type));
13800 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
13804 gcc_unreachable ();
13810 /* Return the tree for abs (ARG0) when ARG0 is known to be either
13811 an integer constant or real constant.
13813 TYPE is the type of the result. */
13816 fold_abs_const (tree arg0, tree type)
13818 tree t = NULL_TREE;
13820 switch (TREE_CODE (arg0))
13823 /* If the value is unsigned, then the absolute value is
13824 the same as the ordinary value. */
13825 if (TYPE_UNSIGNED (type))
13827 /* Similarly, if the value is non-negative. */
13828 else if (INT_CST_LT (integer_minus_one_node, arg0))
13830 /* If the value is negative, then the absolute value is
13834 unsigned HOST_WIDE_INT low;
13835 HOST_WIDE_INT high;
13836 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
13837 TREE_INT_CST_HIGH (arg0),
13839 t = force_fit_type_double (type, low, high, -1,
13840 overflow | TREE_OVERFLOW (arg0));
13845 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
13846 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
13852 gcc_unreachable ();
13858 /* Return the tree for not (ARG0) when ARG0 is known to be an integer
13859 constant. TYPE is the type of the result. */
13862 fold_not_const (tree arg0, tree type)
13864 tree t = NULL_TREE;
13866 gcc_assert (TREE_CODE (arg0) == INTEGER_CST);
13868 t = force_fit_type_double (type, ~TREE_INT_CST_LOW (arg0),
13869 ~TREE_INT_CST_HIGH (arg0), 0,
13870 TREE_OVERFLOW (arg0));
13875 /* Given CODE, a relational operator, the target type, TYPE and two
13876 constant operands OP0 and OP1, return the result of the
13877 relational operation. If the result is not a compile time
13878 constant, then return NULL_TREE. */
13881 fold_relational_const (enum tree_code code, tree type, tree op0, tree op1)
13883 int result, invert;
13885 /* From here on, the only cases we handle are when the result is
13886 known to be a constant. */
13888 if (TREE_CODE (op0) == REAL_CST && TREE_CODE (op1) == REAL_CST)
13890 const REAL_VALUE_TYPE *c0 = TREE_REAL_CST_PTR (op0);
13891 const REAL_VALUE_TYPE *c1 = TREE_REAL_CST_PTR (op1);
13893 /* Handle the cases where either operand is a NaN. */
13894 if (real_isnan (c0) || real_isnan (c1))
13904 case UNORDERED_EXPR:
13918 if (flag_trapping_math)
13924 gcc_unreachable ();
13927 return constant_boolean_node (result, type);
13930 return constant_boolean_node (real_compare (code, c0, c1), type);
13933 /* From here on we only handle LT, LE, GT, GE, EQ and NE.
13935 To compute GT, swap the arguments and do LT.
13936 To compute GE, do LT and invert the result.
13937 To compute LE, swap the arguments, do LT and invert the result.
13938 To compute NE, do EQ and invert the result.
13940 Therefore, the code below must handle only EQ and LT. */
13942 if (code == LE_EXPR || code == GT_EXPR)
13947 code = swap_tree_comparison (code);
13950 /* Note that it is safe to invert for real values here because we
13951 have already handled the one case that it matters. */
13954 if (code == NE_EXPR || code == GE_EXPR)
13957 code = invert_tree_comparison (code, false);
13960 /* Compute a result for LT or EQ if args permit;
13961 Otherwise return T. */
13962 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
13964 if (code == EQ_EXPR)
13965 result = tree_int_cst_equal (op0, op1);
13966 else if (TYPE_UNSIGNED (TREE_TYPE (op0)))
13967 result = INT_CST_LT_UNSIGNED (op0, op1);
13969 result = INT_CST_LT (op0, op1);
13976 return constant_boolean_node (result, type);
13979 /* Build an expression for the a clean point containing EXPR with type TYPE.
13980 Don't build a cleanup point expression for EXPR which don't have side
13984 fold_build_cleanup_point_expr (tree type, tree expr)
13986 /* If the expression does not have side effects then we don't have to wrap
13987 it with a cleanup point expression. */
13988 if (!TREE_SIDE_EFFECTS (expr))
13991 /* If the expression is a return, check to see if the expression inside the
13992 return has no side effects or the right hand side of the modify expression
13993 inside the return. If either don't have side effects set we don't need to
13994 wrap the expression in a cleanup point expression. Note we don't check the
13995 left hand side of the modify because it should always be a return decl. */
13996 if (TREE_CODE (expr) == RETURN_EXPR)
13998 tree op = TREE_OPERAND (expr, 0);
13999 if (!op || !TREE_SIDE_EFFECTS (op))
14001 op = TREE_OPERAND (op, 1);
14002 if (!TREE_SIDE_EFFECTS (op))
14006 return build1 (CLEANUP_POINT_EXPR, type, expr);
14009 /* Build an expression for the address of T. Folds away INDIRECT_REF to
14010 avoid confusing the gimplify process. */
14013 build_fold_addr_expr_with_type (tree t, tree ptrtype)
14015 /* The size of the object is not relevant when talking about its address. */
14016 if (TREE_CODE (t) == WITH_SIZE_EXPR)
14017 t = TREE_OPERAND (t, 0);
14019 /* Note: doesn't apply to ALIGN_INDIRECT_REF */
14020 if (TREE_CODE (t) == INDIRECT_REF
14021 || TREE_CODE (t) == MISALIGNED_INDIRECT_REF)
14023 t = TREE_OPERAND (t, 0);
14024 if (TREE_TYPE (t) != ptrtype)
14025 t = build1 (NOP_EXPR, ptrtype, t);
14031 while (handled_component_p (base))
14032 base = TREE_OPERAND (base, 0);
14034 TREE_ADDRESSABLE (base) = 1;
14036 t = build1 (ADDR_EXPR, ptrtype, t);
14043 build_fold_addr_expr (tree t)
14045 return build_fold_addr_expr_with_type (t, build_pointer_type (TREE_TYPE (t)));
14048 /* Given a pointer value OP0 and a type TYPE, return a simplified version
14049 of an indirection through OP0, or NULL_TREE if no simplification is
14053 fold_indirect_ref_1 (tree type, tree op0)
14059 subtype = TREE_TYPE (sub);
14060 if (!POINTER_TYPE_P (subtype))
14063 if (TREE_CODE (sub) == ADDR_EXPR)
14065 tree op = TREE_OPERAND (sub, 0);
14066 tree optype = TREE_TYPE (op);
14067 /* *&CONST_DECL -> to the value of the const decl. */
14068 if (TREE_CODE (op) == CONST_DECL)
14069 return DECL_INITIAL (op);
14070 /* *&p => p; make sure to handle *&"str"[cst] here. */
14071 if (type == optype)
14073 tree fop = fold_read_from_constant_string (op);
14079 /* *(foo *)&fooarray => fooarray[0] */
14080 else if (TREE_CODE (optype) == ARRAY_TYPE
14081 && type == TREE_TYPE (optype))
14083 tree type_domain = TYPE_DOMAIN (optype);
14084 tree min_val = size_zero_node;
14085 if (type_domain && TYPE_MIN_VALUE (type_domain))
14086 min_val = TYPE_MIN_VALUE (type_domain);
14087 return build4 (ARRAY_REF, type, op, min_val, NULL_TREE, NULL_TREE);
14089 /* *(foo *)&complexfoo => __real__ complexfoo */
14090 else if (TREE_CODE (optype) == COMPLEX_TYPE
14091 && type == TREE_TYPE (optype))
14092 return fold_build1 (REALPART_EXPR, type, op);
14093 /* *(foo *)&vectorfoo => BIT_FIELD_REF<vectorfoo,...> */
14094 else if (TREE_CODE (optype) == VECTOR_TYPE
14095 && type == TREE_TYPE (optype))
14097 tree part_width = TYPE_SIZE (type);
14098 tree index = bitsize_int (0);
14099 return fold_build3 (BIT_FIELD_REF, type, op, part_width, index);
14103 /* ((foo*)&complexfoo)[1] => __imag__ complexfoo */
14104 if (TREE_CODE (sub) == PLUS_EXPR
14105 && TREE_CODE (TREE_OPERAND (sub, 1)) == INTEGER_CST)
14107 tree op00 = TREE_OPERAND (sub, 0);
14108 tree op01 = TREE_OPERAND (sub, 1);
14112 op00type = TREE_TYPE (op00);
14113 if (TREE_CODE (op00) == ADDR_EXPR
14114 && TREE_CODE (TREE_TYPE (op00type)) == COMPLEX_TYPE
14115 && type == TREE_TYPE (TREE_TYPE (op00type)))
14117 tree size = TYPE_SIZE_UNIT (type);
14118 if (tree_int_cst_equal (size, op01))
14119 return fold_build1 (IMAGPART_EXPR, type, TREE_OPERAND (op00, 0));
14123 /* *(foo *)fooarrptr => (*fooarrptr)[0] */
14124 if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE
14125 && type == TREE_TYPE (TREE_TYPE (subtype)))
14128 tree min_val = size_zero_node;
14129 sub = build_fold_indirect_ref (sub);
14130 type_domain = TYPE_DOMAIN (TREE_TYPE (sub));
14131 if (type_domain && TYPE_MIN_VALUE (type_domain))
14132 min_val = TYPE_MIN_VALUE (type_domain);
14133 return build4 (ARRAY_REF, type, sub, min_val, NULL_TREE, NULL_TREE);
14139 /* Builds an expression for an indirection through T, simplifying some
14143 build_fold_indirect_ref (tree t)
14145 tree type = TREE_TYPE (TREE_TYPE (t));
14146 tree sub = fold_indirect_ref_1 (type, t);
14151 return build1 (INDIRECT_REF, type, t);
14154 /* Given an INDIRECT_REF T, return either T or a simplified version. */
14157 fold_indirect_ref (tree t)
14159 tree sub = fold_indirect_ref_1 (TREE_TYPE (t), TREE_OPERAND (t, 0));
14167 /* Strip non-trapping, non-side-effecting tree nodes from an expression
14168 whose result is ignored. The type of the returned tree need not be
14169 the same as the original expression. */
14172 fold_ignored_result (tree t)
14174 if (!TREE_SIDE_EFFECTS (t))
14175 return integer_zero_node;
14178 switch (TREE_CODE_CLASS (TREE_CODE (t)))
14181 t = TREE_OPERAND (t, 0);
14185 case tcc_comparison:
14186 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
14187 t = TREE_OPERAND (t, 0);
14188 else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0)))
14189 t = TREE_OPERAND (t, 1);
14194 case tcc_expression:
14195 switch (TREE_CODE (t))
14197 case COMPOUND_EXPR:
14198 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
14200 t = TREE_OPERAND (t, 0);
14204 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1))
14205 || TREE_SIDE_EFFECTS (TREE_OPERAND (t, 2)))
14207 t = TREE_OPERAND (t, 0);
14220 /* Return the value of VALUE, rounded up to a multiple of DIVISOR.
14221 This can only be applied to objects of a sizetype. */
14224 round_up (tree value, int divisor)
14226 tree div = NULL_TREE;
14228 gcc_assert (divisor > 0);
14232 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
14233 have to do anything. Only do this when we are not given a const,
14234 because in that case, this check is more expensive than just
14236 if (TREE_CODE (value) != INTEGER_CST)
14238 div = build_int_cst (TREE_TYPE (value), divisor);
14240 if (multiple_of_p (TREE_TYPE (value), value, div))
14244 /* If divisor is a power of two, simplify this to bit manipulation. */
14245 if (divisor == (divisor & -divisor))
14247 if (TREE_CODE (value) == INTEGER_CST)
14249 unsigned HOST_WIDE_INT low = TREE_INT_CST_LOW (value);
14250 unsigned HOST_WIDE_INT high;
14253 if ((low & (divisor - 1)) == 0)
14256 overflow_p = TREE_OVERFLOW (value);
14257 high = TREE_INT_CST_HIGH (value);
14258 low &= ~(divisor - 1);
14267 return force_fit_type_double (TREE_TYPE (value), low, high,
14274 t = build_int_cst (TREE_TYPE (value), divisor - 1);
14275 value = size_binop (PLUS_EXPR, value, t);
14276 t = build_int_cst (TREE_TYPE (value), -divisor);
14277 value = size_binop (BIT_AND_EXPR, value, t);
14283 div = build_int_cst (TREE_TYPE (value), divisor);
14284 value = size_binop (CEIL_DIV_EXPR, value, div);
14285 value = size_binop (MULT_EXPR, value, div);
14291 /* Likewise, but round down. */
14294 round_down (tree value, int divisor)
14296 tree div = NULL_TREE;
14298 gcc_assert (divisor > 0);
14302 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
14303 have to do anything. Only do this when we are not given a const,
14304 because in that case, this check is more expensive than just
14306 if (TREE_CODE (value) != INTEGER_CST)
14308 div = build_int_cst (TREE_TYPE (value), divisor);
14310 if (multiple_of_p (TREE_TYPE (value), value, div))
14314 /* If divisor is a power of two, simplify this to bit manipulation. */
14315 if (divisor == (divisor & -divisor))
14319 t = build_int_cst (TREE_TYPE (value), -divisor);
14320 value = size_binop (BIT_AND_EXPR, value, t);
14325 div = build_int_cst (TREE_TYPE (value), divisor);
14326 value = size_binop (FLOOR_DIV_EXPR, value, div);
14327 value = size_binop (MULT_EXPR, value, div);
14333 /* Returns the pointer to the base of the object addressed by EXP and
14334 extracts the information about the offset of the access, storing it
14335 to PBITPOS and POFFSET. */
14338 split_address_to_core_and_offset (tree exp,
14339 HOST_WIDE_INT *pbitpos, tree *poffset)
14342 enum machine_mode mode;
14343 int unsignedp, volatilep;
14344 HOST_WIDE_INT bitsize;
14346 if (TREE_CODE (exp) == ADDR_EXPR)
14348 core = get_inner_reference (TREE_OPERAND (exp, 0), &bitsize, pbitpos,
14349 poffset, &mode, &unsignedp, &volatilep,
14351 core = build_fold_addr_expr (core);
14357 *poffset = NULL_TREE;
14363 /* Returns true if addresses of E1 and E2 differ by a constant, false
14364 otherwise. If they do, E1 - E2 is stored in *DIFF. */
14367 ptr_difference_const (tree e1, tree e2, HOST_WIDE_INT *diff)
14370 HOST_WIDE_INT bitpos1, bitpos2;
14371 tree toffset1, toffset2, tdiff, type;
14373 core1 = split_address_to_core_and_offset (e1, &bitpos1, &toffset1);
14374 core2 = split_address_to_core_and_offset (e2, &bitpos2, &toffset2);
14376 if (bitpos1 % BITS_PER_UNIT != 0
14377 || bitpos2 % BITS_PER_UNIT != 0
14378 || !operand_equal_p (core1, core2, 0))
14381 if (toffset1 && toffset2)
14383 type = TREE_TYPE (toffset1);
14384 if (type != TREE_TYPE (toffset2))
14385 toffset2 = fold_convert (type, toffset2);
14387 tdiff = fold_build2 (MINUS_EXPR, type, toffset1, toffset2);
14388 if (!cst_and_fits_in_hwi (tdiff))
14391 *diff = int_cst_value (tdiff);
14393 else if (toffset1 || toffset2)
14395 /* If only one of the offsets is non-constant, the difference cannot
14402 *diff += (bitpos1 - bitpos2) / BITS_PER_UNIT;
14406 /* Simplify the floating point expression EXP when the sign of the
14407 result is not significant. Return NULL_TREE if no simplification
14411 fold_strip_sign_ops (tree exp)
14415 switch (TREE_CODE (exp))
14419 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
14420 return arg0 ? arg0 : TREE_OPERAND (exp, 0);
14424 if (HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (exp))))
14426 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
14427 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
14428 if (arg0 != NULL_TREE || arg1 != NULL_TREE)
14429 return fold_build2 (TREE_CODE (exp), TREE_TYPE (exp),
14430 arg0 ? arg0 : TREE_OPERAND (exp, 0),
14431 arg1 ? arg1 : TREE_OPERAND (exp, 1));
14434 case COMPOUND_EXPR:
14435 arg0 = TREE_OPERAND (exp, 0);
14436 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
14438 return fold_build2 (COMPOUND_EXPR, TREE_TYPE (exp), arg0, arg1);
14442 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
14443 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 2));
14445 return fold_build3 (COND_EXPR, TREE_TYPE (exp), TREE_OPERAND (exp, 0),
14446 arg0 ? arg0 : TREE_OPERAND (exp, 1),
14447 arg1 ? arg1 : TREE_OPERAND (exp, 2));
14452 const enum built_in_function fcode = builtin_mathfn_code (exp);
14455 CASE_FLT_FN (BUILT_IN_COPYSIGN):
14456 /* Strip copysign function call, return the 1st argument. */
14457 arg0 = CALL_EXPR_ARG (exp, 0);
14458 arg1 = CALL_EXPR_ARG (exp, 1);
14459 return omit_one_operand (TREE_TYPE (exp), arg0, arg1);
14462 /* Strip sign ops from the argument of "odd" math functions. */
14463 if (negate_mathfn_p (fcode))
14465 arg0 = fold_strip_sign_ops (CALL_EXPR_ARG (exp, 0));
14467 return build_call_expr (get_callee_fndecl (exp), 1, arg0);