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 tree fold_binary_op_with_conditional_arg (enum tree_code, tree,
137 static bool fold_real_zero_addition_p (tree, tree, int);
138 static tree fold_mathfn_compare (enum built_in_function, enum tree_code,
140 static tree fold_inf_compare (enum tree_code, tree, tree, tree);
141 static tree fold_div_compare (enum tree_code, tree, tree, tree);
142 static bool reorder_operands_p (tree, tree);
143 static tree fold_negate_const (tree, tree);
144 static tree fold_not_const (tree, tree);
145 static tree fold_relational_const (enum tree_code, tree, tree, tree);
148 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
149 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
150 and SUM1. Then this yields nonzero if overflow occurred during the
153 Overflow occurs if A and B have the same sign, but A and SUM differ in
154 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
156 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
158 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
159 We do that by representing the two-word integer in 4 words, with only
160 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
161 number. The value of the word is LOWPART + HIGHPART * BASE. */
164 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
165 #define HIGHPART(x) \
166 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
167 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
169 /* Unpack a two-word integer into 4 words.
170 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
171 WORDS points to the array of HOST_WIDE_INTs. */
174 encode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT low, HOST_WIDE_INT hi)
176 words[0] = LOWPART (low);
177 words[1] = HIGHPART (low);
178 words[2] = LOWPART (hi);
179 words[3] = HIGHPART (hi);
182 /* Pack an array of 4 words into a two-word integer.
183 WORDS points to the array of words.
184 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
187 decode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT *low,
190 *low = words[0] + words[1] * BASE;
191 *hi = words[2] + words[3] * BASE;
194 /* Force the double-word integer L1, H1 to be within the range of the
195 integer type TYPE. Stores the properly truncated and sign-extended
196 double-word integer in *LV, *HV. Returns true if the operation
197 overflows, that is, argument and result are different. */
200 fit_double_type (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
201 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv, tree type)
203 unsigned HOST_WIDE_INT low0 = l1;
204 HOST_WIDE_INT high0 = h1;
206 int sign_extended_type;
208 if (POINTER_TYPE_P (type)
209 || TREE_CODE (type) == OFFSET_TYPE)
212 prec = TYPE_PRECISION (type);
214 /* Size types *are* sign extended. */
215 sign_extended_type = (!TYPE_UNSIGNED (type)
216 || (TREE_CODE (type) == INTEGER_TYPE
217 && TYPE_IS_SIZETYPE (type)));
219 /* First clear all bits that are beyond the type's precision. */
220 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
222 else if (prec > HOST_BITS_PER_WIDE_INT)
223 h1 &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
227 if (prec < HOST_BITS_PER_WIDE_INT)
228 l1 &= ~((HOST_WIDE_INT) (-1) << prec);
231 /* Then do sign extension if necessary. */
232 if (!sign_extended_type)
233 /* No sign extension */;
234 else if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
235 /* Correct width already. */;
236 else if (prec > HOST_BITS_PER_WIDE_INT)
238 /* Sign extend top half? */
239 if (h1 & ((unsigned HOST_WIDE_INT)1
240 << (prec - HOST_BITS_PER_WIDE_INT - 1)))
241 h1 |= (HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT);
243 else if (prec == HOST_BITS_PER_WIDE_INT)
245 if ((HOST_WIDE_INT)l1 < 0)
250 /* Sign extend bottom half? */
251 if (l1 & ((unsigned HOST_WIDE_INT)1 << (prec - 1)))
254 l1 |= (HOST_WIDE_INT)(-1) << prec;
261 /* If the value didn't fit, signal overflow. */
262 return l1 != low0 || h1 != high0;
265 /* We force the double-int HIGH:LOW to the range of the type TYPE by
266 sign or zero extending it.
267 OVERFLOWABLE indicates if we are interested
268 in overflow of the value, when >0 we are only interested in signed
269 overflow, for <0 we are interested in any overflow. OVERFLOWED
270 indicates whether overflow has already occurred. CONST_OVERFLOWED
271 indicates whether constant overflow has already occurred. We force
272 T's value to be within range of T's type (by setting to 0 or 1 all
273 the bits outside the type's range). We set TREE_OVERFLOWED if,
274 OVERFLOWED is nonzero,
275 or OVERFLOWABLE is >0 and signed overflow occurs
276 or OVERFLOWABLE is <0 and any overflow occurs
277 We return a new tree node for the extended double-int. The node
278 is shared if no overflow flags are set. */
281 force_fit_type_double (tree type, unsigned HOST_WIDE_INT low,
282 HOST_WIDE_INT high, int overflowable,
285 int sign_extended_type;
288 /* Size types *are* sign extended. */
289 sign_extended_type = (!TYPE_UNSIGNED (type)
290 || (TREE_CODE (type) == INTEGER_TYPE
291 && TYPE_IS_SIZETYPE (type)));
293 overflow = fit_double_type (low, high, &low, &high, type);
295 /* If we need to set overflow flags, return a new unshared node. */
296 if (overflowed || overflow)
300 || (overflowable > 0 && sign_extended_type))
302 tree t = make_node (INTEGER_CST);
303 TREE_INT_CST_LOW (t) = low;
304 TREE_INT_CST_HIGH (t) = high;
305 TREE_TYPE (t) = type;
306 TREE_OVERFLOW (t) = 1;
311 /* Else build a shared node. */
312 return build_int_cst_wide (type, low, high);
315 /* Add two doubleword integers with doubleword result.
316 Return nonzero if the operation overflows according to UNSIGNED_P.
317 Each argument is given as two `HOST_WIDE_INT' pieces.
318 One argument is L1 and H1; the other, L2 and H2.
319 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
322 add_double_with_sign (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
323 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
324 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
327 unsigned HOST_WIDE_INT l;
331 h = h1 + h2 + (l < l1);
337 return (unsigned HOST_WIDE_INT) h < (unsigned HOST_WIDE_INT) h1;
339 return OVERFLOW_SUM_SIGN (h1, h2, h);
342 /* Negate a doubleword integer with doubleword result.
343 Return nonzero if the operation overflows, assuming it's signed.
344 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
345 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
348 neg_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
349 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
355 return (*hv & h1) < 0;
365 /* Multiply two doubleword integers with doubleword result.
366 Return nonzero if the operation overflows according to UNSIGNED_P.
367 Each argument is given as two `HOST_WIDE_INT' pieces.
368 One argument is L1 and H1; the other, L2 and H2.
369 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
372 mul_double_with_sign (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
373 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
374 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
377 HOST_WIDE_INT arg1[4];
378 HOST_WIDE_INT arg2[4];
379 HOST_WIDE_INT prod[4 * 2];
380 unsigned HOST_WIDE_INT carry;
382 unsigned HOST_WIDE_INT toplow, neglow;
383 HOST_WIDE_INT tophigh, neghigh;
385 encode (arg1, l1, h1);
386 encode (arg2, l2, h2);
388 memset (prod, 0, sizeof prod);
390 for (i = 0; i < 4; i++)
393 for (j = 0; j < 4; j++)
396 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
397 carry += arg1[i] * arg2[j];
398 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
400 prod[k] = LOWPART (carry);
401 carry = HIGHPART (carry);
406 decode (prod, lv, hv);
407 decode (prod + 4, &toplow, &tophigh);
409 /* Unsigned overflow is immediate. */
411 return (toplow | tophigh) != 0;
413 /* Check for signed overflow by calculating the signed representation of the
414 top half of the result; it should agree with the low half's sign bit. */
417 neg_double (l2, h2, &neglow, &neghigh);
418 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
422 neg_double (l1, h1, &neglow, &neghigh);
423 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
425 return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
428 /* Shift the doubleword integer in L1, H1 left by COUNT places
429 keeping only PREC bits of result.
430 Shift right if COUNT is negative.
431 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
432 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
435 lshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
436 HOST_WIDE_INT count, unsigned int prec,
437 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv, int arith)
439 unsigned HOST_WIDE_INT signmask;
443 rshift_double (l1, h1, -count, prec, lv, hv, arith);
447 if (SHIFT_COUNT_TRUNCATED)
450 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
452 /* Shifting by the host word size is undefined according to the
453 ANSI standard, so we must handle this as a special case. */
457 else if (count >= HOST_BITS_PER_WIDE_INT)
459 *hv = l1 << (count - HOST_BITS_PER_WIDE_INT);
464 *hv = (((unsigned HOST_WIDE_INT) h1 << count)
465 | (l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
469 /* Sign extend all bits that are beyond the precision. */
471 signmask = -((prec > HOST_BITS_PER_WIDE_INT
472 ? ((unsigned HOST_WIDE_INT) *hv
473 >> (prec - HOST_BITS_PER_WIDE_INT - 1))
474 : (*lv >> (prec - 1))) & 1);
476 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
478 else if (prec >= HOST_BITS_PER_WIDE_INT)
480 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
481 *hv |= signmask << (prec - HOST_BITS_PER_WIDE_INT);
486 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
487 *lv |= signmask << prec;
491 /* Shift the doubleword integer in L1, H1 right by COUNT places
492 keeping only PREC bits of result. COUNT must be positive.
493 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
494 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
497 rshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
498 HOST_WIDE_INT count, unsigned int prec,
499 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
502 unsigned HOST_WIDE_INT signmask;
505 ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
508 if (SHIFT_COUNT_TRUNCATED)
511 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
513 /* Shifting by the host word size is undefined according to the
514 ANSI standard, so we must handle this as a special case. */
518 else if (count >= HOST_BITS_PER_WIDE_INT)
521 *lv = (unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT);
525 *hv = (unsigned HOST_WIDE_INT) h1 >> count;
527 | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
530 /* Zero / sign extend all bits that are beyond the precision. */
532 if (count >= (HOST_WIDE_INT)prec)
537 else if ((prec - count) >= 2 * HOST_BITS_PER_WIDE_INT)
539 else if ((prec - count) >= HOST_BITS_PER_WIDE_INT)
541 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - count - HOST_BITS_PER_WIDE_INT));
542 *hv |= signmask << (prec - count - HOST_BITS_PER_WIDE_INT);
547 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << (prec - count));
548 *lv |= signmask << (prec - count);
552 /* Rotate the doubleword integer in L1, H1 left by COUNT places
553 keeping only PREC bits of result.
554 Rotate right if COUNT is negative.
555 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
558 lrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
559 HOST_WIDE_INT count, unsigned int prec,
560 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
562 unsigned HOST_WIDE_INT s1l, s2l;
563 HOST_WIDE_INT s1h, s2h;
569 lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
570 rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
575 /* Rotate the doubleword integer in L1, H1 left by COUNT places
576 keeping only PREC bits of result. COUNT must be positive.
577 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
580 rrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
581 HOST_WIDE_INT count, unsigned int prec,
582 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
584 unsigned HOST_WIDE_INT s1l, s2l;
585 HOST_WIDE_INT s1h, s2h;
591 rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
592 lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
597 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
598 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
599 CODE is a tree code for a kind of division, one of
600 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
602 It controls how the quotient is rounded to an integer.
603 Return nonzero if the operation overflows.
604 UNS nonzero says do unsigned division. */
607 div_and_round_double (enum tree_code code, int uns,
608 unsigned HOST_WIDE_INT lnum_orig, /* num == numerator == dividend */
609 HOST_WIDE_INT hnum_orig,
610 unsigned HOST_WIDE_INT lden_orig, /* den == denominator == divisor */
611 HOST_WIDE_INT hden_orig,
612 unsigned HOST_WIDE_INT *lquo,
613 HOST_WIDE_INT *hquo, unsigned HOST_WIDE_INT *lrem,
617 HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
618 HOST_WIDE_INT den[4], quo[4];
620 unsigned HOST_WIDE_INT work;
621 unsigned HOST_WIDE_INT carry = 0;
622 unsigned HOST_WIDE_INT lnum = lnum_orig;
623 HOST_WIDE_INT hnum = hnum_orig;
624 unsigned HOST_WIDE_INT lden = lden_orig;
625 HOST_WIDE_INT hden = hden_orig;
628 if (hden == 0 && lden == 0)
629 overflow = 1, lden = 1;
631 /* Calculate quotient sign and convert operands to unsigned. */
637 /* (minimum integer) / (-1) is the only overflow case. */
638 if (neg_double (lnum, hnum, &lnum, &hnum)
639 && ((HOST_WIDE_INT) lden & hden) == -1)
645 neg_double (lden, hden, &lden, &hden);
649 if (hnum == 0 && hden == 0)
650 { /* single precision */
652 /* This unsigned division rounds toward zero. */
658 { /* trivial case: dividend < divisor */
659 /* hden != 0 already checked. */
666 memset (quo, 0, sizeof quo);
668 memset (num, 0, sizeof num); /* to zero 9th element */
669 memset (den, 0, sizeof den);
671 encode (num, lnum, hnum);
672 encode (den, lden, hden);
674 /* Special code for when the divisor < BASE. */
675 if (hden == 0 && lden < (unsigned HOST_WIDE_INT) BASE)
677 /* hnum != 0 already checked. */
678 for (i = 4 - 1; i >= 0; i--)
680 work = num[i] + carry * BASE;
681 quo[i] = work / lden;
687 /* Full double precision division,
688 with thanks to Don Knuth's "Seminumerical Algorithms". */
689 int num_hi_sig, den_hi_sig;
690 unsigned HOST_WIDE_INT quo_est, scale;
692 /* Find the highest nonzero divisor digit. */
693 for (i = 4 - 1;; i--)
700 /* Insure that the first digit of the divisor is at least BASE/2.
701 This is required by the quotient digit estimation algorithm. */
703 scale = BASE / (den[den_hi_sig] + 1);
705 { /* scale divisor and dividend */
707 for (i = 0; i <= 4 - 1; i++)
709 work = (num[i] * scale) + carry;
710 num[i] = LOWPART (work);
711 carry = HIGHPART (work);
716 for (i = 0; i <= 4 - 1; i++)
718 work = (den[i] * scale) + carry;
719 den[i] = LOWPART (work);
720 carry = HIGHPART (work);
721 if (den[i] != 0) den_hi_sig = i;
728 for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--)
730 /* Guess the next quotient digit, quo_est, by dividing the first
731 two remaining dividend digits by the high order quotient digit.
732 quo_est is never low and is at most 2 high. */
733 unsigned HOST_WIDE_INT tmp;
735 num_hi_sig = i + den_hi_sig + 1;
736 work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
737 if (num[num_hi_sig] != den[den_hi_sig])
738 quo_est = work / den[den_hi_sig];
742 /* Refine quo_est so it's usually correct, and at most one high. */
743 tmp = work - quo_est * den[den_hi_sig];
745 && (den[den_hi_sig - 1] * quo_est
746 > (tmp * BASE + num[num_hi_sig - 2])))
749 /* Try QUO_EST as the quotient digit, by multiplying the
750 divisor by QUO_EST and subtracting from the remaining dividend.
751 Keep in mind that QUO_EST is the I - 1st digit. */
754 for (j = 0; j <= den_hi_sig; j++)
756 work = quo_est * den[j] + carry;
757 carry = HIGHPART (work);
758 work = num[i + j] - LOWPART (work);
759 num[i + j] = LOWPART (work);
760 carry += HIGHPART (work) != 0;
763 /* If quo_est was high by one, then num[i] went negative and
764 we need to correct things. */
765 if (num[num_hi_sig] < (HOST_WIDE_INT) carry)
768 carry = 0; /* add divisor back in */
769 for (j = 0; j <= den_hi_sig; j++)
771 work = num[i + j] + den[j] + carry;
772 carry = HIGHPART (work);
773 num[i + j] = LOWPART (work);
776 num [num_hi_sig] += carry;
779 /* Store the quotient digit. */
784 decode (quo, lquo, hquo);
787 /* If result is negative, make it so. */
789 neg_double (*lquo, *hquo, lquo, hquo);
791 /* Compute trial remainder: rem = num - (quo * den) */
792 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
793 neg_double (*lrem, *hrem, lrem, hrem);
794 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
799 case TRUNC_MOD_EXPR: /* round toward zero */
800 case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
804 case FLOOR_MOD_EXPR: /* round toward negative infinity */
805 if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
808 add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
816 case CEIL_MOD_EXPR: /* round toward positive infinity */
817 if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
819 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
827 case ROUND_MOD_EXPR: /* round to closest integer */
829 unsigned HOST_WIDE_INT labs_rem = *lrem;
830 HOST_WIDE_INT habs_rem = *hrem;
831 unsigned HOST_WIDE_INT labs_den = lden, ltwice;
832 HOST_WIDE_INT habs_den = hden, htwice;
834 /* Get absolute values. */
836 neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
838 neg_double (lden, hden, &labs_den, &habs_den);
840 /* If (2 * abs (lrem) >= abs (lden)) */
841 mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
842 labs_rem, habs_rem, <wice, &htwice);
844 if (((unsigned HOST_WIDE_INT) habs_den
845 < (unsigned HOST_WIDE_INT) htwice)
846 || (((unsigned HOST_WIDE_INT) habs_den
847 == (unsigned HOST_WIDE_INT) htwice)
848 && (labs_den < ltwice)))
852 add_double (*lquo, *hquo,
853 (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
856 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
868 /* Compute true remainder: rem = num - (quo * den) */
869 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
870 neg_double (*lrem, *hrem, lrem, hrem);
871 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
875 /* If ARG2 divides ARG1 with zero remainder, carries out the division
876 of type CODE and returns the quotient.
877 Otherwise returns NULL_TREE. */
880 div_if_zero_remainder (enum tree_code code, tree arg1, tree arg2)
882 unsigned HOST_WIDE_INT int1l, int2l;
883 HOST_WIDE_INT int1h, int2h;
884 unsigned HOST_WIDE_INT quol, reml;
885 HOST_WIDE_INT quoh, remh;
886 tree type = TREE_TYPE (arg1);
887 int uns = TYPE_UNSIGNED (type);
889 int1l = TREE_INT_CST_LOW (arg1);
890 int1h = TREE_INT_CST_HIGH (arg1);
891 /* &obj[0] + -128 really should be compiled as &obj[-8] rahter than
892 &obj[some_exotic_number]. */
893 if (POINTER_TYPE_P (type))
896 type = signed_type_for (type);
897 fit_double_type (int1l, int1h, &int1l, &int1h,
901 fit_double_type (int1l, int1h, &int1l, &int1h, type);
902 int2l = TREE_INT_CST_LOW (arg2);
903 int2h = TREE_INT_CST_HIGH (arg2);
905 div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
906 &quol, &quoh, &reml, &remh);
907 if (remh != 0 || reml != 0)
910 return build_int_cst_wide (type, quol, quoh);
913 /* This is non-zero if we should defer warnings about undefined
914 overflow. This facility exists because these warnings are a
915 special case. The code to estimate loop iterations does not want
916 to issue any warnings, since it works with expressions which do not
917 occur in user code. Various bits of cleanup code call fold(), but
918 only use the result if it has certain characteristics (e.g., is a
919 constant); that code only wants to issue a warning if the result is
922 static int fold_deferring_overflow_warnings;
924 /* If a warning about undefined overflow is deferred, this is the
925 warning. Note that this may cause us to turn two warnings into
926 one, but that is fine since it is sufficient to only give one
927 warning per expression. */
929 static const char* fold_deferred_overflow_warning;
931 /* If a warning about undefined overflow is deferred, this is the
932 level at which the warning should be emitted. */
934 static enum warn_strict_overflow_code fold_deferred_overflow_code;
936 /* Start deferring overflow warnings. We could use a stack here to
937 permit nested calls, but at present it is not necessary. */
940 fold_defer_overflow_warnings (void)
942 ++fold_deferring_overflow_warnings;
945 /* Stop deferring overflow warnings. If there is a pending warning,
946 and ISSUE is true, then issue the warning if appropriate. STMT is
947 the statement with which the warning should be associated (used for
948 location information); STMT may be NULL. CODE is the level of the
949 warning--a warn_strict_overflow_code value. This function will use
950 the smaller of CODE and the deferred code when deciding whether to
951 issue the warning. CODE may be zero to mean to always use the
955 fold_undefer_overflow_warnings (bool issue, tree stmt, int code)
960 gcc_assert (fold_deferring_overflow_warnings > 0);
961 --fold_deferring_overflow_warnings;
962 if (fold_deferring_overflow_warnings > 0)
964 if (fold_deferred_overflow_warning != NULL
966 && code < (int) fold_deferred_overflow_code)
967 fold_deferred_overflow_code = code;
971 warnmsg = fold_deferred_overflow_warning;
972 fold_deferred_overflow_warning = NULL;
974 if (!issue || warnmsg == NULL)
977 /* Use the smallest code level when deciding to issue the
979 if (code == 0 || code > (int) fold_deferred_overflow_code)
980 code = fold_deferred_overflow_code;
982 if (!issue_strict_overflow_warning (code))
985 if (stmt == NULL_TREE || !expr_has_location (stmt))
986 locus = input_location;
988 locus = expr_location (stmt);
989 warning (OPT_Wstrict_overflow, "%H%s", &locus, warnmsg);
992 /* Stop deferring overflow warnings, ignoring any deferred
996 fold_undefer_and_ignore_overflow_warnings (void)
998 fold_undefer_overflow_warnings (false, NULL_TREE, 0);
1001 /* Whether we are deferring overflow warnings. */
1004 fold_deferring_overflow_warnings_p (void)
1006 return fold_deferring_overflow_warnings > 0;
1009 /* This is called when we fold something based on the fact that signed
1010 overflow is undefined. */
1013 fold_overflow_warning (const char* gmsgid, enum warn_strict_overflow_code wc)
1015 gcc_assert (!flag_wrapv && !flag_trapv);
1016 if (fold_deferring_overflow_warnings > 0)
1018 if (fold_deferred_overflow_warning == NULL
1019 || wc < fold_deferred_overflow_code)
1021 fold_deferred_overflow_warning = gmsgid;
1022 fold_deferred_overflow_code = wc;
1025 else if (issue_strict_overflow_warning (wc))
1026 warning (OPT_Wstrict_overflow, gmsgid);
1029 /* Return true if the built-in mathematical function specified by CODE
1030 is odd, i.e. -f(x) == f(-x). */
1033 negate_mathfn_p (enum built_in_function code)
1037 CASE_FLT_FN (BUILT_IN_ASIN):
1038 CASE_FLT_FN (BUILT_IN_ASINH):
1039 CASE_FLT_FN (BUILT_IN_ATAN):
1040 CASE_FLT_FN (BUILT_IN_ATANH):
1041 CASE_FLT_FN (BUILT_IN_CASIN):
1042 CASE_FLT_FN (BUILT_IN_CASINH):
1043 CASE_FLT_FN (BUILT_IN_CATAN):
1044 CASE_FLT_FN (BUILT_IN_CATANH):
1045 CASE_FLT_FN (BUILT_IN_CBRT):
1046 CASE_FLT_FN (BUILT_IN_CPROJ):
1047 CASE_FLT_FN (BUILT_IN_CSIN):
1048 CASE_FLT_FN (BUILT_IN_CSINH):
1049 CASE_FLT_FN (BUILT_IN_CTAN):
1050 CASE_FLT_FN (BUILT_IN_CTANH):
1051 CASE_FLT_FN (BUILT_IN_ERF):
1052 CASE_FLT_FN (BUILT_IN_LLROUND):
1053 CASE_FLT_FN (BUILT_IN_LROUND):
1054 CASE_FLT_FN (BUILT_IN_ROUND):
1055 CASE_FLT_FN (BUILT_IN_SIN):
1056 CASE_FLT_FN (BUILT_IN_SINH):
1057 CASE_FLT_FN (BUILT_IN_TAN):
1058 CASE_FLT_FN (BUILT_IN_TANH):
1059 CASE_FLT_FN (BUILT_IN_TRUNC):
1062 CASE_FLT_FN (BUILT_IN_LLRINT):
1063 CASE_FLT_FN (BUILT_IN_LRINT):
1064 CASE_FLT_FN (BUILT_IN_NEARBYINT):
1065 CASE_FLT_FN (BUILT_IN_RINT):
1066 return !flag_rounding_math;
1074 /* Check whether we may negate an integer constant T without causing
1078 may_negate_without_overflow_p (tree t)
1080 unsigned HOST_WIDE_INT val;
1084 gcc_assert (TREE_CODE (t) == INTEGER_CST);
1086 type = TREE_TYPE (t);
1087 if (TYPE_UNSIGNED (type))
1090 prec = TYPE_PRECISION (type);
1091 if (prec > HOST_BITS_PER_WIDE_INT)
1093 if (TREE_INT_CST_LOW (t) != 0)
1095 prec -= HOST_BITS_PER_WIDE_INT;
1096 val = TREE_INT_CST_HIGH (t);
1099 val = TREE_INT_CST_LOW (t);
1100 if (prec < HOST_BITS_PER_WIDE_INT)
1101 val &= ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
1102 return val != ((unsigned HOST_WIDE_INT) 1 << (prec - 1));
1105 /* Determine whether an expression T can be cheaply negated using
1106 the function negate_expr without introducing undefined overflow. */
1109 negate_expr_p (tree t)
1116 type = TREE_TYPE (t);
1118 STRIP_SIGN_NOPS (t);
1119 switch (TREE_CODE (t))
1122 if (TYPE_OVERFLOW_WRAPS (type))
1125 /* Check that -CST will not overflow type. */
1126 return may_negate_without_overflow_p (t);
1128 return (INTEGRAL_TYPE_P (type)
1129 && TYPE_OVERFLOW_WRAPS (type));
1136 return negate_expr_p (TREE_REALPART (t))
1137 && negate_expr_p (TREE_IMAGPART (t));
1140 return negate_expr_p (TREE_OPERAND (t, 0))
1141 && negate_expr_p (TREE_OPERAND (t, 1));
1144 return negate_expr_p (TREE_OPERAND (t, 0));
1147 if (HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1148 || HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
1150 /* -(A + B) -> (-B) - A. */
1151 if (negate_expr_p (TREE_OPERAND (t, 1))
1152 && reorder_operands_p (TREE_OPERAND (t, 0),
1153 TREE_OPERAND (t, 1)))
1155 /* -(A + B) -> (-A) - B. */
1156 return negate_expr_p (TREE_OPERAND (t, 0));
1159 /* We can't turn -(A-B) into B-A when we honor signed zeros. */
1160 return !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1161 && !HONOR_SIGNED_ZEROS (TYPE_MODE (type))
1162 && reorder_operands_p (TREE_OPERAND (t, 0),
1163 TREE_OPERAND (t, 1));
1166 if (TYPE_UNSIGNED (TREE_TYPE (t)))
1172 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
1173 return negate_expr_p (TREE_OPERAND (t, 1))
1174 || negate_expr_p (TREE_OPERAND (t, 0));
1177 case TRUNC_DIV_EXPR:
1178 case ROUND_DIV_EXPR:
1179 case FLOOR_DIV_EXPR:
1181 case EXACT_DIV_EXPR:
1182 /* In general we can't negate A / B, because if A is INT_MIN and
1183 B is 1, we may turn this into INT_MIN / -1 which is undefined
1184 and actually traps on some architectures. But if overflow is
1185 undefined, we can negate, because - (INT_MIN / 1) is an
1187 if (INTEGRAL_TYPE_P (TREE_TYPE (t))
1188 && !TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (t)))
1190 return negate_expr_p (TREE_OPERAND (t, 1))
1191 || negate_expr_p (TREE_OPERAND (t, 0));
1194 /* Negate -((double)float) as (double)(-float). */
1195 if (TREE_CODE (type) == REAL_TYPE)
1197 tree tem = strip_float_extensions (t);
1199 return negate_expr_p (tem);
1204 /* Negate -f(x) as f(-x). */
1205 if (negate_mathfn_p (builtin_mathfn_code (t)))
1206 return negate_expr_p (CALL_EXPR_ARG (t, 0));
1210 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1211 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
1213 tree op1 = TREE_OPERAND (t, 1);
1214 if (TREE_INT_CST_HIGH (op1) == 0
1215 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
1216 == TREE_INT_CST_LOW (op1))
1227 /* Given T, an expression, return a folded tree for -T or NULL_TREE, if no
1228 simplification is possible.
1229 If negate_expr_p would return true for T, NULL_TREE will never be
1233 fold_negate_expr (tree t)
1235 tree type = TREE_TYPE (t);
1238 switch (TREE_CODE (t))
1240 /* Convert - (~A) to A + 1. */
1242 if (INTEGRAL_TYPE_P (type))
1243 return fold_build2 (PLUS_EXPR, type, TREE_OPERAND (t, 0),
1244 build_int_cst (type, 1));
1248 tem = fold_negate_const (t, type);
1249 if (TREE_OVERFLOW (tem) == TREE_OVERFLOW (t)
1250 || !TYPE_OVERFLOW_TRAPS (type))
1255 tem = fold_negate_const (t, type);
1256 /* Two's complement FP formats, such as c4x, may overflow. */
1257 if (!TREE_OVERFLOW (tem) || !flag_trapping_math)
1263 tree rpart = negate_expr (TREE_REALPART (t));
1264 tree ipart = negate_expr (TREE_IMAGPART (t));
1266 if ((TREE_CODE (rpart) == REAL_CST
1267 && TREE_CODE (ipart) == REAL_CST)
1268 || (TREE_CODE (rpart) == INTEGER_CST
1269 && TREE_CODE (ipart) == INTEGER_CST))
1270 return build_complex (type, rpart, ipart);
1275 if (negate_expr_p (t))
1276 return fold_build2 (COMPLEX_EXPR, type,
1277 fold_negate_expr (TREE_OPERAND (t, 0)),
1278 fold_negate_expr (TREE_OPERAND (t, 1)));
1282 if (negate_expr_p (t))
1283 return fold_build1 (CONJ_EXPR, type,
1284 fold_negate_expr (TREE_OPERAND (t, 0)));
1288 return TREE_OPERAND (t, 0);
1291 if (!HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1292 && !HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
1294 /* -(A + B) -> (-B) - A. */
1295 if (negate_expr_p (TREE_OPERAND (t, 1))
1296 && reorder_operands_p (TREE_OPERAND (t, 0),
1297 TREE_OPERAND (t, 1)))
1299 tem = negate_expr (TREE_OPERAND (t, 1));
1300 return fold_build2 (MINUS_EXPR, type,
1301 tem, TREE_OPERAND (t, 0));
1304 /* -(A + B) -> (-A) - B. */
1305 if (negate_expr_p (TREE_OPERAND (t, 0)))
1307 tem = negate_expr (TREE_OPERAND (t, 0));
1308 return fold_build2 (MINUS_EXPR, type,
1309 tem, TREE_OPERAND (t, 1));
1315 /* - (A - B) -> B - A */
1316 if (!HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1317 && !HONOR_SIGNED_ZEROS (TYPE_MODE (type))
1318 && reorder_operands_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1)))
1319 return fold_build2 (MINUS_EXPR, type,
1320 TREE_OPERAND (t, 1), TREE_OPERAND (t, 0));
1324 if (TYPE_UNSIGNED (type))
1330 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type)))
1332 tem = TREE_OPERAND (t, 1);
1333 if (negate_expr_p (tem))
1334 return fold_build2 (TREE_CODE (t), type,
1335 TREE_OPERAND (t, 0), negate_expr (tem));
1336 tem = TREE_OPERAND (t, 0);
1337 if (negate_expr_p (tem))
1338 return fold_build2 (TREE_CODE (t), type,
1339 negate_expr (tem), TREE_OPERAND (t, 1));
1343 case TRUNC_DIV_EXPR:
1344 case ROUND_DIV_EXPR:
1345 case FLOOR_DIV_EXPR:
1347 case EXACT_DIV_EXPR:
1348 /* In general we can't negate A / B, because if A is INT_MIN and
1349 B is 1, we may turn this into INT_MIN / -1 which is undefined
1350 and actually traps on some architectures. But if overflow is
1351 undefined, we can negate, because - (INT_MIN / 1) is an
1353 if (!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
1355 const char * const warnmsg = G_("assuming signed overflow does not "
1356 "occur when negating a division");
1357 tem = TREE_OPERAND (t, 1);
1358 if (negate_expr_p (tem))
1360 if (INTEGRAL_TYPE_P (type)
1361 && (TREE_CODE (tem) != INTEGER_CST
1362 || integer_onep (tem)))
1363 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MISC);
1364 return fold_build2 (TREE_CODE (t), type,
1365 TREE_OPERAND (t, 0), negate_expr (tem));
1367 tem = TREE_OPERAND (t, 0);
1368 if (negate_expr_p (tem))
1370 if (INTEGRAL_TYPE_P (type)
1371 && (TREE_CODE (tem) != INTEGER_CST
1372 || tree_int_cst_equal (tem, TYPE_MIN_VALUE (type))))
1373 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MISC);
1374 return fold_build2 (TREE_CODE (t), type,
1375 negate_expr (tem), TREE_OPERAND (t, 1));
1381 /* Convert -((double)float) into (double)(-float). */
1382 if (TREE_CODE (type) == REAL_TYPE)
1384 tem = strip_float_extensions (t);
1385 if (tem != t && negate_expr_p (tem))
1386 return negate_expr (tem);
1391 /* Negate -f(x) as f(-x). */
1392 if (negate_mathfn_p (builtin_mathfn_code (t))
1393 && negate_expr_p (CALL_EXPR_ARG (t, 0)))
1397 fndecl = get_callee_fndecl (t);
1398 arg = negate_expr (CALL_EXPR_ARG (t, 0));
1399 return build_call_expr (fndecl, 1, arg);
1404 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1405 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
1407 tree op1 = TREE_OPERAND (t, 1);
1408 if (TREE_INT_CST_HIGH (op1) == 0
1409 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
1410 == TREE_INT_CST_LOW (op1))
1412 tree ntype = TYPE_UNSIGNED (type)
1413 ? lang_hooks.types.signed_type (type)
1414 : lang_hooks.types.unsigned_type (type);
1415 tree temp = fold_convert (ntype, TREE_OPERAND (t, 0));
1416 temp = fold_build2 (RSHIFT_EXPR, ntype, temp, op1);
1417 return fold_convert (type, temp);
1429 /* Like fold_negate_expr, but return a NEGATE_EXPR tree, if T can not be
1430 negated in a simpler way. Also allow for T to be NULL_TREE, in which case
1431 return NULL_TREE. */
1434 negate_expr (tree t)
1441 type = TREE_TYPE (t);
1442 STRIP_SIGN_NOPS (t);
1444 tem = fold_negate_expr (t);
1446 tem = build1 (NEGATE_EXPR, TREE_TYPE (t), t);
1447 return fold_convert (type, tem);
1450 /* Split a tree IN into a constant, literal and variable parts that could be
1451 combined with CODE to make IN. "constant" means an expression with
1452 TREE_CONSTANT but that isn't an actual constant. CODE must be a
1453 commutative arithmetic operation. Store the constant part into *CONP,
1454 the literal in *LITP and return the variable part. If a part isn't
1455 present, set it to null. If the tree does not decompose in this way,
1456 return the entire tree as the variable part and the other parts as null.
1458 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
1459 case, we negate an operand that was subtracted. Except if it is a
1460 literal for which we use *MINUS_LITP instead.
1462 If NEGATE_P is true, we are negating all of IN, again except a literal
1463 for which we use *MINUS_LITP instead.
1465 If IN is itself a literal or constant, return it as appropriate.
1467 Note that we do not guarantee that any of the three values will be the
1468 same type as IN, but they will have the same signedness and mode. */
1471 split_tree (tree in, enum tree_code code, tree *conp, tree *litp,
1472 tree *minus_litp, int negate_p)
1480 /* Strip any conversions that don't change the machine mode or signedness. */
1481 STRIP_SIGN_NOPS (in);
1483 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST)
1485 else if (TREE_CODE (in) == code
1486 || (! FLOAT_TYPE_P (TREE_TYPE (in))
1487 /* We can associate addition and subtraction together (even
1488 though the C standard doesn't say so) for integers because
1489 the value is not affected. For reals, the value might be
1490 affected, so we can't. */
1491 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
1492 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
1494 tree op0 = TREE_OPERAND (in, 0);
1495 tree op1 = TREE_OPERAND (in, 1);
1496 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
1497 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
1499 /* First see if either of the operands is a literal, then a constant. */
1500 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
1501 *litp = op0, op0 = 0;
1502 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST)
1503 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
1505 if (op0 != 0 && TREE_CONSTANT (op0))
1506 *conp = op0, op0 = 0;
1507 else if (op1 != 0 && TREE_CONSTANT (op1))
1508 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
1510 /* If we haven't dealt with either operand, this is not a case we can
1511 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1512 if (op0 != 0 && op1 != 0)
1517 var = op1, neg_var_p = neg1_p;
1519 /* Now do any needed negations. */
1521 *minus_litp = *litp, *litp = 0;
1523 *conp = negate_expr (*conp);
1525 var = negate_expr (var);
1527 else if (TREE_CONSTANT (in))
1535 *minus_litp = *litp, *litp = 0;
1536 else if (*minus_litp)
1537 *litp = *minus_litp, *minus_litp = 0;
1538 *conp = negate_expr (*conp);
1539 var = negate_expr (var);
1545 /* Re-associate trees split by the above function. T1 and T2 are either
1546 expressions to associate or null. Return the new expression, if any. If
1547 we build an operation, do it in TYPE and with CODE. */
1550 associate_trees (tree t1, tree t2, enum tree_code code, tree type)
1557 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1558 try to fold this since we will have infinite recursion. But do
1559 deal with any NEGATE_EXPRs. */
1560 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
1561 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1563 if (code == PLUS_EXPR)
1565 if (TREE_CODE (t1) == NEGATE_EXPR)
1566 return build2 (MINUS_EXPR, type, fold_convert (type, t2),
1567 fold_convert (type, TREE_OPERAND (t1, 0)));
1568 else if (TREE_CODE (t2) == NEGATE_EXPR)
1569 return build2 (MINUS_EXPR, type, fold_convert (type, t1),
1570 fold_convert (type, TREE_OPERAND (t2, 0)));
1571 else if (integer_zerop (t2))
1572 return fold_convert (type, t1);
1574 else if (code == MINUS_EXPR)
1576 if (integer_zerop (t2))
1577 return fold_convert (type, t1);
1580 return build2 (code, type, fold_convert (type, t1),
1581 fold_convert (type, t2));
1584 return fold_build2 (code, type, fold_convert (type, t1),
1585 fold_convert (type, t2));
1588 /* Check whether TYPE1 and TYPE2 are equivalent integer types, suitable
1589 for use in int_const_binop, size_binop and size_diffop. */
1592 int_binop_types_match_p (enum tree_code code, tree type1, tree type2)
1594 if (TREE_CODE (type1) != INTEGER_TYPE && !POINTER_TYPE_P (type1))
1596 if (TREE_CODE (type2) != INTEGER_TYPE && !POINTER_TYPE_P (type2))
1611 return TYPE_UNSIGNED (type1) == TYPE_UNSIGNED (type2)
1612 && TYPE_PRECISION (type1) == TYPE_PRECISION (type2)
1613 && TYPE_MODE (type1) == TYPE_MODE (type2);
1617 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1618 to produce a new constant. Return NULL_TREE if we don't know how
1619 to evaluate CODE at compile-time.
1621 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1624 int_const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1626 unsigned HOST_WIDE_INT int1l, int2l;
1627 HOST_WIDE_INT int1h, int2h;
1628 unsigned HOST_WIDE_INT low;
1630 unsigned HOST_WIDE_INT garbagel;
1631 HOST_WIDE_INT garbageh;
1633 tree type = TREE_TYPE (arg1);
1634 int uns = TYPE_UNSIGNED (type);
1636 = (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type));
1639 int1l = TREE_INT_CST_LOW (arg1);
1640 int1h = TREE_INT_CST_HIGH (arg1);
1641 int2l = TREE_INT_CST_LOW (arg2);
1642 int2h = TREE_INT_CST_HIGH (arg2);
1647 low = int1l | int2l, hi = int1h | int2h;
1651 low = int1l ^ int2l, hi = int1h ^ int2h;
1655 low = int1l & int2l, hi = int1h & int2h;
1661 /* It's unclear from the C standard whether shifts can overflow.
1662 The following code ignores overflow; perhaps a C standard
1663 interpretation ruling is needed. */
1664 lshift_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1671 lrotate_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1676 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1680 neg_double (int2l, int2h, &low, &hi);
1681 add_double (int1l, int1h, low, hi, &low, &hi);
1682 overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
1686 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1689 case TRUNC_DIV_EXPR:
1690 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1691 case EXACT_DIV_EXPR:
1692 /* This is a shortcut for a common special case. */
1693 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1694 && !TREE_OVERFLOW (arg1)
1695 && !TREE_OVERFLOW (arg2)
1696 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1698 if (code == CEIL_DIV_EXPR)
1701 low = int1l / int2l, hi = 0;
1705 /* ... fall through ... */
1707 case ROUND_DIV_EXPR:
1708 if (int2h == 0 && int2l == 0)
1710 if (int2h == 0 && int2l == 1)
1712 low = int1l, hi = int1h;
1715 if (int1l == int2l && int1h == int2h
1716 && ! (int1l == 0 && int1h == 0))
1721 overflow = div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
1722 &low, &hi, &garbagel, &garbageh);
1725 case TRUNC_MOD_EXPR:
1726 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1727 /* This is a shortcut for a common special case. */
1728 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1729 && !TREE_OVERFLOW (arg1)
1730 && !TREE_OVERFLOW (arg2)
1731 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1733 if (code == CEIL_MOD_EXPR)
1735 low = int1l % int2l, hi = 0;
1739 /* ... fall through ... */
1741 case ROUND_MOD_EXPR:
1742 if (int2h == 0 && int2l == 0)
1744 overflow = div_and_round_double (code, uns,
1745 int1l, int1h, int2l, int2h,
1746 &garbagel, &garbageh, &low, &hi);
1752 low = (((unsigned HOST_WIDE_INT) int1h
1753 < (unsigned HOST_WIDE_INT) int2h)
1754 || (((unsigned HOST_WIDE_INT) int1h
1755 == (unsigned HOST_WIDE_INT) int2h)
1758 low = (int1h < int2h
1759 || (int1h == int2h && int1l < int2l));
1761 if (low == (code == MIN_EXPR))
1762 low = int1l, hi = int1h;
1764 low = int2l, hi = int2h;
1773 t = build_int_cst_wide (TREE_TYPE (arg1), low, hi);
1775 /* Propagate overflow flags ourselves. */
1776 if (((!uns || is_sizetype) && overflow)
1777 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2))
1780 TREE_OVERFLOW (t) = 1;
1784 t = force_fit_type_double (TREE_TYPE (arg1), low, hi, 1,
1785 ((!uns || is_sizetype) && overflow)
1786 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
1791 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1792 constant. We assume ARG1 and ARG2 have the same data type, or at least
1793 are the same kind of constant and the same machine mode. Return zero if
1794 combining the constants is not allowed in the current operating mode.
1796 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1799 const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1801 /* Sanity check for the recursive cases. */
1808 if (TREE_CODE (arg1) == INTEGER_CST)
1809 return int_const_binop (code, arg1, arg2, notrunc);
1811 if (TREE_CODE (arg1) == REAL_CST)
1813 enum machine_mode mode;
1816 REAL_VALUE_TYPE value;
1817 REAL_VALUE_TYPE result;
1821 /* The following codes are handled by real_arithmetic. */
1836 d1 = TREE_REAL_CST (arg1);
1837 d2 = TREE_REAL_CST (arg2);
1839 type = TREE_TYPE (arg1);
1840 mode = TYPE_MODE (type);
1842 /* Don't perform operation if we honor signaling NaNs and
1843 either operand is a NaN. */
1844 if (HONOR_SNANS (mode)
1845 && (REAL_VALUE_ISNAN (d1) || REAL_VALUE_ISNAN (d2)))
1848 /* Don't perform operation if it would raise a division
1849 by zero exception. */
1850 if (code == RDIV_EXPR
1851 && REAL_VALUES_EQUAL (d2, dconst0)
1852 && (flag_trapping_math || ! MODE_HAS_INFINITIES (mode)))
1855 /* If either operand is a NaN, just return it. Otherwise, set up
1856 for floating-point trap; we return an overflow. */
1857 if (REAL_VALUE_ISNAN (d1))
1859 else if (REAL_VALUE_ISNAN (d2))
1862 inexact = real_arithmetic (&value, code, &d1, &d2);
1863 real_convert (&result, mode, &value);
1865 /* Don't constant fold this floating point operation if
1866 the result has overflowed and flag_trapping_math. */
1867 if (flag_trapping_math
1868 && MODE_HAS_INFINITIES (mode)
1869 && REAL_VALUE_ISINF (result)
1870 && !REAL_VALUE_ISINF (d1)
1871 && !REAL_VALUE_ISINF (d2))
1874 /* Don't constant fold this floating point operation if the
1875 result may dependent upon the run-time rounding mode and
1876 flag_rounding_math is set, or if GCC's software emulation
1877 is unable to accurately represent the result. */
1878 if ((flag_rounding_math
1879 || (REAL_MODE_FORMAT_COMPOSITE_P (mode)
1880 && !flag_unsafe_math_optimizations))
1881 && (inexact || !real_identical (&result, &value)))
1884 t = build_real (type, result);
1886 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2);
1890 if (TREE_CODE (arg1) == COMPLEX_CST)
1892 tree type = TREE_TYPE (arg1);
1893 tree r1 = TREE_REALPART (arg1);
1894 tree i1 = TREE_IMAGPART (arg1);
1895 tree r2 = TREE_REALPART (arg2);
1896 tree i2 = TREE_IMAGPART (arg2);
1903 real = const_binop (code, r1, r2, notrunc);
1904 imag = const_binop (code, i1, i2, notrunc);
1908 real = const_binop (MINUS_EXPR,
1909 const_binop (MULT_EXPR, r1, r2, notrunc),
1910 const_binop (MULT_EXPR, i1, i2, notrunc),
1912 imag = const_binop (PLUS_EXPR,
1913 const_binop (MULT_EXPR, r1, i2, notrunc),
1914 const_binop (MULT_EXPR, i1, r2, notrunc),
1921 = const_binop (PLUS_EXPR,
1922 const_binop (MULT_EXPR, r2, r2, notrunc),
1923 const_binop (MULT_EXPR, i2, i2, notrunc),
1926 = const_binop (PLUS_EXPR,
1927 const_binop (MULT_EXPR, r1, r2, notrunc),
1928 const_binop (MULT_EXPR, i1, i2, notrunc),
1931 = const_binop (MINUS_EXPR,
1932 const_binop (MULT_EXPR, i1, r2, notrunc),
1933 const_binop (MULT_EXPR, r1, i2, notrunc),
1936 if (INTEGRAL_TYPE_P (TREE_TYPE (r1)))
1937 code = TRUNC_DIV_EXPR;
1939 real = const_binop (code, t1, magsquared, notrunc);
1940 imag = const_binop (code, t2, magsquared, notrunc);
1949 return build_complex (type, real, imag);
1955 /* Create a size type INT_CST node with NUMBER sign extended. KIND
1956 indicates which particular sizetype to create. */
1959 size_int_kind (HOST_WIDE_INT number, enum size_type_kind kind)
1961 return build_int_cst (sizetype_tab[(int) kind], number);
1964 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1965 is a tree code. The type of the result is taken from the operands.
1966 Both must be equivalent integer types, ala int_binop_types_match_p.
1967 If the operands are constant, so is the result. */
1970 size_binop (enum tree_code code, tree arg0, tree arg1)
1972 tree type = TREE_TYPE (arg0);
1974 if (arg0 == error_mark_node || arg1 == error_mark_node)
1975 return error_mark_node;
1977 gcc_assert (int_binop_types_match_p (code, TREE_TYPE (arg0),
1980 /* Handle the special case of two integer constants faster. */
1981 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1983 /* And some specific cases even faster than that. */
1984 if (code == PLUS_EXPR)
1986 if (integer_zerop (arg0) && !TREE_OVERFLOW (arg0))
1988 if (integer_zerop (arg1) && !TREE_OVERFLOW (arg1))
1991 else if (code == MINUS_EXPR)
1993 if (integer_zerop (arg1) && !TREE_OVERFLOW (arg1))
1996 else if (code == MULT_EXPR)
1998 if (integer_onep (arg0) && !TREE_OVERFLOW (arg0))
2002 /* Handle general case of two integer constants. */
2003 return int_const_binop (code, arg0, arg1, 0);
2006 return fold_build2 (code, type, arg0, arg1);
2009 /* Given two values, either both of sizetype or both of bitsizetype,
2010 compute the difference between the two values. Return the value
2011 in signed type corresponding to the type of the operands. */
2014 size_diffop (tree arg0, tree arg1)
2016 tree type = TREE_TYPE (arg0);
2019 gcc_assert (int_binop_types_match_p (MINUS_EXPR, TREE_TYPE (arg0),
2022 /* If the type is already signed, just do the simple thing. */
2023 if (!TYPE_UNSIGNED (type))
2024 return size_binop (MINUS_EXPR, arg0, arg1);
2026 if (type == sizetype)
2028 else if (type == bitsizetype)
2029 ctype = sbitsizetype;
2031 ctype = lang_hooks.types.signed_type (type);
2033 /* If either operand is not a constant, do the conversions to the signed
2034 type and subtract. The hardware will do the right thing with any
2035 overflow in the subtraction. */
2036 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
2037 return size_binop (MINUS_EXPR, fold_convert (ctype, arg0),
2038 fold_convert (ctype, arg1));
2040 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
2041 Otherwise, subtract the other way, convert to CTYPE (we know that can't
2042 overflow) and negate (which can't either). Special-case a result
2043 of zero while we're here. */
2044 if (tree_int_cst_equal (arg0, arg1))
2045 return build_int_cst (ctype, 0);
2046 else if (tree_int_cst_lt (arg1, arg0))
2047 return fold_convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
2049 return size_binop (MINUS_EXPR, build_int_cst (ctype, 0),
2050 fold_convert (ctype, size_binop (MINUS_EXPR,
2054 /* A subroutine of fold_convert_const handling conversions of an
2055 INTEGER_CST to another integer type. */
2058 fold_convert_const_int_from_int (tree type, tree arg1)
2062 /* Given an integer constant, make new constant with new type,
2063 appropriately sign-extended or truncated. */
2064 t = force_fit_type_double (type, TREE_INT_CST_LOW (arg1),
2065 TREE_INT_CST_HIGH (arg1),
2066 /* Don't set the overflow when
2067 converting a pointer */
2068 !POINTER_TYPE_P (TREE_TYPE (arg1)),
2069 (TREE_INT_CST_HIGH (arg1) < 0
2070 && (TYPE_UNSIGNED (type)
2071 < TYPE_UNSIGNED (TREE_TYPE (arg1))))
2072 | TREE_OVERFLOW (arg1));
2077 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2078 to an integer type. */
2081 fold_convert_const_int_from_real (enum tree_code code, tree type, tree arg1)
2086 /* The following code implements the floating point to integer
2087 conversion rules required by the Java Language Specification,
2088 that IEEE NaNs are mapped to zero and values that overflow
2089 the target precision saturate, i.e. values greater than
2090 INT_MAX are mapped to INT_MAX, and values less than INT_MIN
2091 are mapped to INT_MIN. These semantics are allowed by the
2092 C and C++ standards that simply state that the behavior of
2093 FP-to-integer conversion is unspecified upon overflow. */
2095 HOST_WIDE_INT high, low;
2097 REAL_VALUE_TYPE x = TREE_REAL_CST (arg1);
2101 case FIX_TRUNC_EXPR:
2102 real_trunc (&r, VOIDmode, &x);
2109 /* If R is NaN, return zero and show we have an overflow. */
2110 if (REAL_VALUE_ISNAN (r))
2117 /* See if R is less than the lower bound or greater than the
2122 tree lt = TYPE_MIN_VALUE (type);
2123 REAL_VALUE_TYPE l = real_value_from_int_cst (NULL_TREE, lt);
2124 if (REAL_VALUES_LESS (r, l))
2127 high = TREE_INT_CST_HIGH (lt);
2128 low = TREE_INT_CST_LOW (lt);
2134 tree ut = TYPE_MAX_VALUE (type);
2137 REAL_VALUE_TYPE u = real_value_from_int_cst (NULL_TREE, ut);
2138 if (REAL_VALUES_LESS (u, r))
2141 high = TREE_INT_CST_HIGH (ut);
2142 low = TREE_INT_CST_LOW (ut);
2148 REAL_VALUE_TO_INT (&low, &high, r);
2150 t = force_fit_type_double (type, low, high, -1,
2151 overflow | TREE_OVERFLOW (arg1));
2155 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2156 to another floating point type. */
2159 fold_convert_const_real_from_real (tree type, tree arg1)
2161 REAL_VALUE_TYPE value;
2164 real_convert (&value, TYPE_MODE (type), &TREE_REAL_CST (arg1));
2165 t = build_real (type, value);
2167 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1);
2171 /* Attempt to fold type conversion operation CODE of expression ARG1 to
2172 type TYPE. If no simplification can be done return NULL_TREE. */
2175 fold_convert_const (enum tree_code code, tree type, tree arg1)
2177 if (TREE_TYPE (arg1) == type)
2180 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
2182 if (TREE_CODE (arg1) == INTEGER_CST)
2183 return fold_convert_const_int_from_int (type, arg1);
2184 else if (TREE_CODE (arg1) == REAL_CST)
2185 return fold_convert_const_int_from_real (code, type, arg1);
2187 else if (TREE_CODE (type) == REAL_TYPE)
2189 if (TREE_CODE (arg1) == INTEGER_CST)
2190 return build_real_from_int_cst (type, arg1);
2191 if (TREE_CODE (arg1) == REAL_CST)
2192 return fold_convert_const_real_from_real (type, arg1);
2197 /* Construct a vector of zero elements of vector type TYPE. */
2200 build_zero_vector (tree type)
2205 elem = fold_convert_const (NOP_EXPR, TREE_TYPE (type), integer_zero_node);
2206 units = TYPE_VECTOR_SUBPARTS (type);
2209 for (i = 0; i < units; i++)
2210 list = tree_cons (NULL_TREE, elem, list);
2211 return build_vector (type, list);
2214 /* Convert expression ARG to type TYPE. Used by the middle-end for
2215 simple conversions in preference to calling the front-end's convert. */
2218 fold_convert (tree type, tree arg)
2220 tree orig = TREE_TYPE (arg);
2226 if (TREE_CODE (arg) == ERROR_MARK
2227 || TREE_CODE (type) == ERROR_MARK
2228 || TREE_CODE (orig) == ERROR_MARK)
2229 return error_mark_node;
2231 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig)
2232 || lang_hooks.types_compatible_p (TYPE_MAIN_VARIANT (type),
2233 TYPE_MAIN_VARIANT (orig)))
2234 return fold_build1 (NOP_EXPR, type, arg);
2236 switch (TREE_CODE (type))
2238 case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
2239 case POINTER_TYPE: case REFERENCE_TYPE:
2241 if (TREE_CODE (arg) == INTEGER_CST)
2243 tem = fold_convert_const (NOP_EXPR, type, arg);
2244 if (tem != NULL_TREE)
2247 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
2248 || TREE_CODE (orig) == OFFSET_TYPE)
2249 return fold_build1 (NOP_EXPR, type, arg);
2250 if (TREE_CODE (orig) == COMPLEX_TYPE)
2252 tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2253 return fold_convert (type, tem);
2255 gcc_assert (TREE_CODE (orig) == VECTOR_TYPE
2256 && tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
2257 return fold_build1 (NOP_EXPR, type, arg);
2260 if (TREE_CODE (arg) == INTEGER_CST)
2262 tem = fold_convert_const (FLOAT_EXPR, type, arg);
2263 if (tem != NULL_TREE)
2266 else if (TREE_CODE (arg) == REAL_CST)
2268 tem = fold_convert_const (NOP_EXPR, type, arg);
2269 if (tem != NULL_TREE)
2273 switch (TREE_CODE (orig))
2276 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
2277 case POINTER_TYPE: case REFERENCE_TYPE:
2278 return fold_build1 (FLOAT_EXPR, type, arg);
2281 return fold_build1 (NOP_EXPR, type, arg);
2284 tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2285 return fold_convert (type, tem);
2292 switch (TREE_CODE (orig))
2295 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
2296 case POINTER_TYPE: case REFERENCE_TYPE:
2298 return build2 (COMPLEX_EXPR, type,
2299 fold_convert (TREE_TYPE (type), arg),
2300 fold_convert (TREE_TYPE (type), integer_zero_node));
2305 if (TREE_CODE (arg) == COMPLEX_EXPR)
2307 rpart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 0));
2308 ipart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 1));
2309 return fold_build2 (COMPLEX_EXPR, type, rpart, ipart);
2312 arg = save_expr (arg);
2313 rpart = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2314 ipart = fold_build1 (IMAGPART_EXPR, TREE_TYPE (orig), arg);
2315 rpart = fold_convert (TREE_TYPE (type), rpart);
2316 ipart = fold_convert (TREE_TYPE (type), ipart);
2317 return fold_build2 (COMPLEX_EXPR, type, rpart, ipart);
2325 if (integer_zerop (arg))
2326 return build_zero_vector (type);
2327 gcc_assert (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
2328 gcc_assert (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
2329 || TREE_CODE (orig) == VECTOR_TYPE);
2330 return fold_build1 (VIEW_CONVERT_EXPR, type, arg);
2333 tem = fold_ignored_result (arg);
2334 if (TREE_CODE (tem) == GIMPLE_MODIFY_STMT)
2336 return fold_build1 (NOP_EXPR, type, tem);
2343 /* Return false if expr can be assumed not to be an lvalue, true
2347 maybe_lvalue_p (tree x)
2349 /* We only need to wrap lvalue tree codes. */
2350 switch (TREE_CODE (x))
2361 case ALIGN_INDIRECT_REF:
2362 case MISALIGNED_INDIRECT_REF:
2364 case ARRAY_RANGE_REF:
2370 case PREINCREMENT_EXPR:
2371 case PREDECREMENT_EXPR:
2373 case TRY_CATCH_EXPR:
2374 case WITH_CLEANUP_EXPR:
2377 case GIMPLE_MODIFY_STMT:
2386 /* Assume the worst for front-end tree codes. */
2387 if ((int)TREE_CODE (x) >= NUM_TREE_CODES)
2395 /* Return an expr equal to X but certainly not valid as an lvalue. */
2400 /* While we are in GIMPLE, NON_LVALUE_EXPR doesn't mean anything to
2405 if (! maybe_lvalue_p (x))
2407 return build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
2410 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
2411 Zero means allow extended lvalues. */
2413 int pedantic_lvalues;
2415 /* When pedantic, return an expr equal to X but certainly not valid as a
2416 pedantic lvalue. Otherwise, return X. */
2419 pedantic_non_lvalue (tree x)
2421 if (pedantic_lvalues)
2422 return non_lvalue (x);
2427 /* Given a tree comparison code, return the code that is the logical inverse
2428 of the given code. It is not safe to do this for floating-point
2429 comparisons, except for NE_EXPR and EQ_EXPR, so we receive a machine mode
2430 as well: if reversing the comparison is unsafe, return ERROR_MARK. */
2433 invert_tree_comparison (enum tree_code code, bool honor_nans)
2435 if (honor_nans && flag_trapping_math)
2445 return honor_nans ? UNLE_EXPR : LE_EXPR;
2447 return honor_nans ? UNLT_EXPR : LT_EXPR;
2449 return honor_nans ? UNGE_EXPR : GE_EXPR;
2451 return honor_nans ? UNGT_EXPR : GT_EXPR;
2465 return UNORDERED_EXPR;
2466 case UNORDERED_EXPR:
2467 return ORDERED_EXPR;
2473 /* Similar, but return the comparison that results if the operands are
2474 swapped. This is safe for floating-point. */
2477 swap_tree_comparison (enum tree_code code)
2484 case UNORDERED_EXPR:
2510 /* Convert a comparison tree code from an enum tree_code representation
2511 into a compcode bit-based encoding. This function is the inverse of
2512 compcode_to_comparison. */
2514 static enum comparison_code
2515 comparison_to_compcode (enum tree_code code)
2532 return COMPCODE_ORD;
2533 case UNORDERED_EXPR:
2534 return COMPCODE_UNORD;
2536 return COMPCODE_UNLT;
2538 return COMPCODE_UNEQ;
2540 return COMPCODE_UNLE;
2542 return COMPCODE_UNGT;
2544 return COMPCODE_LTGT;
2546 return COMPCODE_UNGE;
2552 /* Convert a compcode bit-based encoding of a comparison operator back
2553 to GCC's enum tree_code representation. This function is the
2554 inverse of comparison_to_compcode. */
2556 static enum tree_code
2557 compcode_to_comparison (enum comparison_code code)
2574 return ORDERED_EXPR;
2575 case COMPCODE_UNORD:
2576 return UNORDERED_EXPR;
2594 /* Return a tree for the comparison which is the combination of
2595 doing the AND or OR (depending on CODE) of the two operations LCODE
2596 and RCODE on the identical operands LL_ARG and LR_ARG. Take into account
2597 the possibility of trapping if the mode has NaNs, and return NULL_TREE
2598 if this makes the transformation invalid. */
2601 combine_comparisons (enum tree_code code, enum tree_code lcode,
2602 enum tree_code rcode, tree truth_type,
2603 tree ll_arg, tree lr_arg)
2605 bool honor_nans = HONOR_NANS (TYPE_MODE (TREE_TYPE (ll_arg)));
2606 enum comparison_code lcompcode = comparison_to_compcode (lcode);
2607 enum comparison_code rcompcode = comparison_to_compcode (rcode);
2608 enum comparison_code compcode;
2612 case TRUTH_AND_EXPR: case TRUTH_ANDIF_EXPR:
2613 compcode = lcompcode & rcompcode;
2616 case TRUTH_OR_EXPR: case TRUTH_ORIF_EXPR:
2617 compcode = lcompcode | rcompcode;
2626 /* Eliminate unordered comparisons, as well as LTGT and ORD
2627 which are not used unless the mode has NaNs. */
2628 compcode &= ~COMPCODE_UNORD;
2629 if (compcode == COMPCODE_LTGT)
2630 compcode = COMPCODE_NE;
2631 else if (compcode == COMPCODE_ORD)
2632 compcode = COMPCODE_TRUE;
2634 else if (flag_trapping_math)
2636 /* Check that the original operation and the optimized ones will trap
2637 under the same condition. */
2638 bool ltrap = (lcompcode & COMPCODE_UNORD) == 0
2639 && (lcompcode != COMPCODE_EQ)
2640 && (lcompcode != COMPCODE_ORD);
2641 bool rtrap = (rcompcode & COMPCODE_UNORD) == 0
2642 && (rcompcode != COMPCODE_EQ)
2643 && (rcompcode != COMPCODE_ORD);
2644 bool trap = (compcode & COMPCODE_UNORD) == 0
2645 && (compcode != COMPCODE_EQ)
2646 && (compcode != COMPCODE_ORD);
2648 /* In a short-circuited boolean expression the LHS might be
2649 such that the RHS, if evaluated, will never trap. For
2650 example, in ORD (x, y) && (x < y), we evaluate the RHS only
2651 if neither x nor y is NaN. (This is a mixed blessing: for
2652 example, the expression above will never trap, hence
2653 optimizing it to x < y would be invalid). */
2654 if ((code == TRUTH_ORIF_EXPR && (lcompcode & COMPCODE_UNORD))
2655 || (code == TRUTH_ANDIF_EXPR && !(lcompcode & COMPCODE_UNORD)))
2658 /* If the comparison was short-circuited, and only the RHS
2659 trapped, we may now generate a spurious trap. */
2661 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2664 /* If we changed the conditions that cause a trap, we lose. */
2665 if ((ltrap || rtrap) != trap)
2669 if (compcode == COMPCODE_TRUE)
2670 return constant_boolean_node (true, truth_type);
2671 else if (compcode == COMPCODE_FALSE)
2672 return constant_boolean_node (false, truth_type);
2674 return fold_build2 (compcode_to_comparison (compcode),
2675 truth_type, ll_arg, lr_arg);
2678 /* Return nonzero if CODE is a tree code that represents a truth value. */
2681 truth_value_p (enum tree_code code)
2683 return (TREE_CODE_CLASS (code) == tcc_comparison
2684 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2685 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2686 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
2689 /* Return nonzero if two operands (typically of the same tree node)
2690 are necessarily equal. If either argument has side-effects this
2691 function returns zero. FLAGS modifies behavior as follows:
2693 If OEP_ONLY_CONST is set, only return nonzero for constants.
2694 This function tests whether the operands are indistinguishable;
2695 it does not test whether they are equal using C's == operation.
2696 The distinction is important for IEEE floating point, because
2697 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2698 (2) two NaNs may be indistinguishable, but NaN!=NaN.
2700 If OEP_ONLY_CONST is unset, a VAR_DECL is considered equal to itself
2701 even though it may hold multiple values during a function.
2702 This is because a GCC tree node guarantees that nothing else is
2703 executed between the evaluation of its "operands" (which may often
2704 be evaluated in arbitrary order). Hence if the operands themselves
2705 don't side-effect, the VAR_DECLs, PARM_DECLs etc... must hold the
2706 same value in each operand/subexpression. Hence leaving OEP_ONLY_CONST
2707 unset means assuming isochronic (or instantaneous) tree equivalence.
2708 Unless comparing arbitrary expression trees, such as from different
2709 statements, this flag can usually be left unset.
2711 If OEP_PURE_SAME is set, then pure functions with identical arguments
2712 are considered the same. It is used when the caller has other ways
2713 to ensure that global memory is unchanged in between. */
2716 operand_equal_p (tree arg0, tree arg1, unsigned int flags)
2718 /* If either is ERROR_MARK, they aren't equal. */
2719 if (TREE_CODE (arg0) == ERROR_MARK || TREE_CODE (arg1) == ERROR_MARK)
2722 /* If both types don't have the same signedness, then we can't consider
2723 them equal. We must check this before the STRIP_NOPS calls
2724 because they may change the signedness of the arguments. */
2725 if (TYPE_UNSIGNED (TREE_TYPE (arg0)) != TYPE_UNSIGNED (TREE_TYPE (arg1)))
2728 /* If both types don't have the same precision, then it is not safe
2730 if (TYPE_PRECISION (TREE_TYPE (arg0)) != TYPE_PRECISION (TREE_TYPE (arg1)))
2736 /* In case both args are comparisons but with different comparison
2737 code, try to swap the comparison operands of one arg to produce
2738 a match and compare that variant. */
2739 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2740 && COMPARISON_CLASS_P (arg0)
2741 && COMPARISON_CLASS_P (arg1))
2743 enum tree_code swap_code = swap_tree_comparison (TREE_CODE (arg1));
2745 if (TREE_CODE (arg0) == swap_code)
2746 return operand_equal_p (TREE_OPERAND (arg0, 0),
2747 TREE_OPERAND (arg1, 1), flags)
2748 && operand_equal_p (TREE_OPERAND (arg0, 1),
2749 TREE_OPERAND (arg1, 0), flags);
2752 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2753 /* This is needed for conversions and for COMPONENT_REF.
2754 Might as well play it safe and always test this. */
2755 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
2756 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
2757 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
2760 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
2761 We don't care about side effects in that case because the SAVE_EXPR
2762 takes care of that for us. In all other cases, two expressions are
2763 equal if they have no side effects. If we have two identical
2764 expressions with side effects that should be treated the same due
2765 to the only side effects being identical SAVE_EXPR's, that will
2766 be detected in the recursive calls below. */
2767 if (arg0 == arg1 && ! (flags & OEP_ONLY_CONST)
2768 && (TREE_CODE (arg0) == SAVE_EXPR
2769 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
2772 /* Next handle constant cases, those for which we can return 1 even
2773 if ONLY_CONST is set. */
2774 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
2775 switch (TREE_CODE (arg0))
2778 return tree_int_cst_equal (arg0, arg1);
2781 if (REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
2782 TREE_REAL_CST (arg1)))
2786 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0))))
2788 /* If we do not distinguish between signed and unsigned zero,
2789 consider them equal. */
2790 if (real_zerop (arg0) && real_zerop (arg1))
2799 v1 = TREE_VECTOR_CST_ELTS (arg0);
2800 v2 = TREE_VECTOR_CST_ELTS (arg1);
2803 if (!operand_equal_p (TREE_VALUE (v1), TREE_VALUE (v2),
2806 v1 = TREE_CHAIN (v1);
2807 v2 = TREE_CHAIN (v2);
2814 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
2816 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
2820 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
2821 && ! memcmp (TREE_STRING_POINTER (arg0),
2822 TREE_STRING_POINTER (arg1),
2823 TREE_STRING_LENGTH (arg0)));
2826 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
2832 if (flags & OEP_ONLY_CONST)
2835 /* Define macros to test an operand from arg0 and arg1 for equality and a
2836 variant that allows null and views null as being different from any
2837 non-null value. In the latter case, if either is null, the both
2838 must be; otherwise, do the normal comparison. */
2839 #define OP_SAME(N) operand_equal_p (TREE_OPERAND (arg0, N), \
2840 TREE_OPERAND (arg1, N), flags)
2842 #define OP_SAME_WITH_NULL(N) \
2843 ((!TREE_OPERAND (arg0, N) || !TREE_OPERAND (arg1, N)) \
2844 ? TREE_OPERAND (arg0, N) == TREE_OPERAND (arg1, N) : OP_SAME (N))
2846 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
2849 /* Two conversions are equal only if signedness and modes match. */
2850 switch (TREE_CODE (arg0))
2854 case FIX_TRUNC_EXPR:
2855 if (TYPE_UNSIGNED (TREE_TYPE (arg0))
2856 != TYPE_UNSIGNED (TREE_TYPE (arg1)))
2866 case tcc_comparison:
2868 if (OP_SAME (0) && OP_SAME (1))
2871 /* For commutative ops, allow the other order. */
2872 return (commutative_tree_code (TREE_CODE (arg0))
2873 && operand_equal_p (TREE_OPERAND (arg0, 0),
2874 TREE_OPERAND (arg1, 1), flags)
2875 && operand_equal_p (TREE_OPERAND (arg0, 1),
2876 TREE_OPERAND (arg1, 0), flags));
2879 /* If either of the pointer (or reference) expressions we are
2880 dereferencing contain a side effect, these cannot be equal. */
2881 if (TREE_SIDE_EFFECTS (arg0)
2882 || TREE_SIDE_EFFECTS (arg1))
2885 switch (TREE_CODE (arg0))
2888 case ALIGN_INDIRECT_REF:
2889 case MISALIGNED_INDIRECT_REF:
2895 case ARRAY_RANGE_REF:
2896 /* Operands 2 and 3 may be null.
2897 Compare the array index by value if it is constant first as we
2898 may have different types but same value here. */
2900 && (tree_int_cst_equal (TREE_OPERAND (arg0, 1),
2901 TREE_OPERAND (arg1, 1))
2903 && OP_SAME_WITH_NULL (2)
2904 && OP_SAME_WITH_NULL (3));
2907 /* Handle operand 2 the same as for ARRAY_REF. Operand 0
2908 may be NULL when we're called to compare MEM_EXPRs. */
2909 return OP_SAME_WITH_NULL (0)
2911 && OP_SAME_WITH_NULL (2);
2914 return OP_SAME (0) && OP_SAME (1) && OP_SAME (2);
2920 case tcc_expression:
2921 switch (TREE_CODE (arg0))
2924 case TRUTH_NOT_EXPR:
2927 case TRUTH_ANDIF_EXPR:
2928 case TRUTH_ORIF_EXPR:
2929 return OP_SAME (0) && OP_SAME (1);
2931 case TRUTH_AND_EXPR:
2933 case TRUTH_XOR_EXPR:
2934 if (OP_SAME (0) && OP_SAME (1))
2937 /* Otherwise take into account this is a commutative operation. */
2938 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2939 TREE_OPERAND (arg1, 1), flags)
2940 && operand_equal_p (TREE_OPERAND (arg0, 1),
2941 TREE_OPERAND (arg1, 0), flags));
2948 switch (TREE_CODE (arg0))
2951 /* If the CALL_EXPRs call different functions, then they
2952 clearly can not be equal. */
2953 if (! operand_equal_p (CALL_EXPR_FN (arg0), CALL_EXPR_FN (arg1),
2958 unsigned int cef = call_expr_flags (arg0);
2959 if (flags & OEP_PURE_SAME)
2960 cef &= ECF_CONST | ECF_PURE;
2967 /* Now see if all the arguments are the same. */
2969 call_expr_arg_iterator iter0, iter1;
2971 for (a0 = first_call_expr_arg (arg0, &iter0),
2972 a1 = first_call_expr_arg (arg1, &iter1);
2974 a0 = next_call_expr_arg (&iter0),
2975 a1 = next_call_expr_arg (&iter1))
2976 if (! operand_equal_p (a0, a1, flags))
2979 /* If we get here and both argument lists are exhausted
2980 then the CALL_EXPRs are equal. */
2981 return ! (a0 || a1);
2987 case tcc_declaration:
2988 /* Consider __builtin_sqrt equal to sqrt. */
2989 return (TREE_CODE (arg0) == FUNCTION_DECL
2990 && DECL_BUILT_IN (arg0) && DECL_BUILT_IN (arg1)
2991 && DECL_BUILT_IN_CLASS (arg0) == DECL_BUILT_IN_CLASS (arg1)
2992 && DECL_FUNCTION_CODE (arg0) == DECL_FUNCTION_CODE (arg1));
2999 #undef OP_SAME_WITH_NULL
3002 /* Similar to operand_equal_p, but see if ARG0 might have been made by
3003 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
3005 When in doubt, return 0. */
3008 operand_equal_for_comparison_p (tree arg0, tree arg1, tree other)
3010 int unsignedp1, unsignedpo;
3011 tree primarg0, primarg1, primother;
3012 unsigned int correct_width;
3014 if (operand_equal_p (arg0, arg1, 0))
3017 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
3018 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
3021 /* Discard any conversions that don't change the modes of ARG0 and ARG1
3022 and see if the inner values are the same. This removes any
3023 signedness comparison, which doesn't matter here. */
3024 primarg0 = arg0, primarg1 = arg1;
3025 STRIP_NOPS (primarg0);
3026 STRIP_NOPS (primarg1);
3027 if (operand_equal_p (primarg0, primarg1, 0))
3030 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
3031 actual comparison operand, ARG0.
3033 First throw away any conversions to wider types
3034 already present in the operands. */
3036 primarg1 = get_narrower (arg1, &unsignedp1);
3037 primother = get_narrower (other, &unsignedpo);
3039 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
3040 if (unsignedp1 == unsignedpo
3041 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
3042 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
3044 tree type = TREE_TYPE (arg0);
3046 /* Make sure shorter operand is extended the right way
3047 to match the longer operand. */
3048 primarg1 = fold_convert (get_signed_or_unsigned_type
3049 (unsignedp1, TREE_TYPE (primarg1)), primarg1);
3051 if (operand_equal_p (arg0, fold_convert (type, primarg1), 0))
3058 /* See if ARG is an expression that is either a comparison or is performing
3059 arithmetic on comparisons. The comparisons must only be comparing
3060 two different values, which will be stored in *CVAL1 and *CVAL2; if
3061 they are nonzero it means that some operands have already been found.
3062 No variables may be used anywhere else in the expression except in the
3063 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
3064 the expression and save_expr needs to be called with CVAL1 and CVAL2.
3066 If this is true, return 1. Otherwise, return zero. */
3069 twoval_comparison_p (tree arg, tree *cval1, tree *cval2, int *save_p)
3071 enum tree_code code = TREE_CODE (arg);
3072 enum tree_code_class class = TREE_CODE_CLASS (code);
3074 /* We can handle some of the tcc_expression cases here. */
3075 if (class == tcc_expression && code == TRUTH_NOT_EXPR)
3077 else if (class == tcc_expression
3078 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
3079 || code == COMPOUND_EXPR))
3082 else if (class == tcc_expression && code == SAVE_EXPR
3083 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
3085 /* If we've already found a CVAL1 or CVAL2, this expression is
3086 two complex to handle. */
3087 if (*cval1 || *cval2)
3097 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
3100 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
3101 && twoval_comparison_p (TREE_OPERAND (arg, 1),
3102 cval1, cval2, save_p));
3107 case tcc_expression:
3108 if (code == COND_EXPR)
3109 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
3110 cval1, cval2, save_p)
3111 && twoval_comparison_p (TREE_OPERAND (arg, 1),
3112 cval1, cval2, save_p)
3113 && twoval_comparison_p (TREE_OPERAND (arg, 2),
3114 cval1, cval2, save_p));
3117 case tcc_comparison:
3118 /* First see if we can handle the first operand, then the second. For
3119 the second operand, we know *CVAL1 can't be zero. It must be that
3120 one side of the comparison is each of the values; test for the
3121 case where this isn't true by failing if the two operands
3124 if (operand_equal_p (TREE_OPERAND (arg, 0),
3125 TREE_OPERAND (arg, 1), 0))
3129 *cval1 = TREE_OPERAND (arg, 0);
3130 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
3132 else if (*cval2 == 0)
3133 *cval2 = TREE_OPERAND (arg, 0);
3134 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
3139 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
3141 else if (*cval2 == 0)
3142 *cval2 = TREE_OPERAND (arg, 1);
3143 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
3155 /* ARG is a tree that is known to contain just arithmetic operations and
3156 comparisons. Evaluate the operations in the tree substituting NEW0 for
3157 any occurrence of OLD0 as an operand of a comparison and likewise for
3161 eval_subst (tree arg, tree old0, tree new0, tree old1, tree new1)
3163 tree type = TREE_TYPE (arg);
3164 enum tree_code code = TREE_CODE (arg);
3165 enum tree_code_class class = TREE_CODE_CLASS (code);
3167 /* We can handle some of the tcc_expression cases here. */
3168 if (class == tcc_expression && code == TRUTH_NOT_EXPR)
3170 else if (class == tcc_expression
3171 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
3177 return fold_build1 (code, type,
3178 eval_subst (TREE_OPERAND (arg, 0),
3179 old0, new0, old1, new1));
3182 return fold_build2 (code, type,
3183 eval_subst (TREE_OPERAND (arg, 0),
3184 old0, new0, old1, new1),
3185 eval_subst (TREE_OPERAND (arg, 1),
3186 old0, new0, old1, new1));
3188 case tcc_expression:
3192 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
3195 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
3198 return fold_build3 (code, type,
3199 eval_subst (TREE_OPERAND (arg, 0),
3200 old0, new0, old1, new1),
3201 eval_subst (TREE_OPERAND (arg, 1),
3202 old0, new0, old1, new1),
3203 eval_subst (TREE_OPERAND (arg, 2),
3204 old0, new0, old1, new1));
3208 /* Fall through - ??? */
3210 case tcc_comparison:
3212 tree arg0 = TREE_OPERAND (arg, 0);
3213 tree arg1 = TREE_OPERAND (arg, 1);
3215 /* We need to check both for exact equality and tree equality. The
3216 former will be true if the operand has a side-effect. In that
3217 case, we know the operand occurred exactly once. */
3219 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
3221 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
3224 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
3226 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
3229 return fold_build2 (code, type, arg0, arg1);
3237 /* Return a tree for the case when the result of an expression is RESULT
3238 converted to TYPE and OMITTED was previously an operand of the expression
3239 but is now not needed (e.g., we folded OMITTED * 0).
3241 If OMITTED has side effects, we must evaluate it. Otherwise, just do
3242 the conversion of RESULT to TYPE. */
3245 omit_one_operand (tree type, tree result, tree omitted)
3247 tree t = fold_convert (type, result);
3249 if (TREE_SIDE_EFFECTS (omitted))
3250 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
3252 return non_lvalue (t);
3255 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
3258 pedantic_omit_one_operand (tree type, tree result, tree omitted)
3260 tree t = fold_convert (type, result);
3262 if (TREE_SIDE_EFFECTS (omitted))
3263 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
3265 return pedantic_non_lvalue (t);
3268 /* Return a tree for the case when the result of an expression is RESULT
3269 converted to TYPE and OMITTED1 and OMITTED2 were previously operands
3270 of the expression but are now not needed.
3272 If OMITTED1 or OMITTED2 has side effects, they must be evaluated.
3273 If both OMITTED1 and OMITTED2 have side effects, OMITTED1 is
3274 evaluated before OMITTED2. Otherwise, if neither has side effects,
3275 just do the conversion of RESULT to TYPE. */
3278 omit_two_operands (tree type, tree result, tree omitted1, tree omitted2)
3280 tree t = fold_convert (type, result);
3282 if (TREE_SIDE_EFFECTS (omitted2))
3283 t = build2 (COMPOUND_EXPR, type, omitted2, t);
3284 if (TREE_SIDE_EFFECTS (omitted1))
3285 t = build2 (COMPOUND_EXPR, type, omitted1, t);
3287 return TREE_CODE (t) != COMPOUND_EXPR ? non_lvalue (t) : t;
3291 /* Return a simplified tree node for the truth-negation of ARG. This
3292 never alters ARG itself. We assume that ARG is an operation that
3293 returns a truth value (0 or 1).
3295 FIXME: one would think we would fold the result, but it causes
3296 problems with the dominator optimizer. */
3299 fold_truth_not_expr (tree arg)
3301 tree type = TREE_TYPE (arg);
3302 enum tree_code code = TREE_CODE (arg);
3304 /* If this is a comparison, we can simply invert it, except for
3305 floating-point non-equality comparisons, in which case we just
3306 enclose a TRUTH_NOT_EXPR around what we have. */
3308 if (TREE_CODE_CLASS (code) == tcc_comparison)
3310 tree op_type = TREE_TYPE (TREE_OPERAND (arg, 0));
3311 if (FLOAT_TYPE_P (op_type)
3312 && flag_trapping_math
3313 && code != ORDERED_EXPR && code != UNORDERED_EXPR
3314 && code != NE_EXPR && code != EQ_EXPR)
3318 code = invert_tree_comparison (code,
3319 HONOR_NANS (TYPE_MODE (op_type)));
3320 if (code == ERROR_MARK)
3323 return build2 (code, type,
3324 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
3331 return constant_boolean_node (integer_zerop (arg), type);
3333 case TRUTH_AND_EXPR:
3334 return build2 (TRUTH_OR_EXPR, type,
3335 invert_truthvalue (TREE_OPERAND (arg, 0)),
3336 invert_truthvalue (TREE_OPERAND (arg, 1)));
3339 return build2 (TRUTH_AND_EXPR, type,
3340 invert_truthvalue (TREE_OPERAND (arg, 0)),
3341 invert_truthvalue (TREE_OPERAND (arg, 1)));
3343 case TRUTH_XOR_EXPR:
3344 /* Here we can invert either operand. We invert the first operand
3345 unless the second operand is a TRUTH_NOT_EXPR in which case our
3346 result is the XOR of the first operand with the inside of the
3347 negation of the second operand. */
3349 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
3350 return build2 (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
3351 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
3353 return build2 (TRUTH_XOR_EXPR, type,
3354 invert_truthvalue (TREE_OPERAND (arg, 0)),
3355 TREE_OPERAND (arg, 1));
3357 case TRUTH_ANDIF_EXPR:
3358 return build2 (TRUTH_ORIF_EXPR, type,
3359 invert_truthvalue (TREE_OPERAND (arg, 0)),
3360 invert_truthvalue (TREE_OPERAND (arg, 1)));
3362 case TRUTH_ORIF_EXPR:
3363 return build2 (TRUTH_ANDIF_EXPR, type,
3364 invert_truthvalue (TREE_OPERAND (arg, 0)),
3365 invert_truthvalue (TREE_OPERAND (arg, 1)));
3367 case TRUTH_NOT_EXPR:
3368 return TREE_OPERAND (arg, 0);
3372 tree arg1 = TREE_OPERAND (arg, 1);
3373 tree arg2 = TREE_OPERAND (arg, 2);
3374 /* A COND_EXPR may have a throw as one operand, which
3375 then has void type. Just leave void operands
3377 return build3 (COND_EXPR, type, TREE_OPERAND (arg, 0),
3378 VOID_TYPE_P (TREE_TYPE (arg1))
3379 ? arg1 : invert_truthvalue (arg1),
3380 VOID_TYPE_P (TREE_TYPE (arg2))
3381 ? arg2 : invert_truthvalue (arg2));
3385 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
3386 invert_truthvalue (TREE_OPERAND (arg, 1)));
3388 case NON_LVALUE_EXPR:
3389 return invert_truthvalue (TREE_OPERAND (arg, 0));
3392 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE)
3393 return build1 (TRUTH_NOT_EXPR, type, arg);
3397 return build1 (TREE_CODE (arg), type,
3398 invert_truthvalue (TREE_OPERAND (arg, 0)));
3401 if (!integer_onep (TREE_OPERAND (arg, 1)))
3403 return build2 (EQ_EXPR, type, arg,
3404 build_int_cst (type, 0));
3407 return build1 (TRUTH_NOT_EXPR, type, arg);
3409 case CLEANUP_POINT_EXPR:
3410 return build1 (CLEANUP_POINT_EXPR, type,
3411 invert_truthvalue (TREE_OPERAND (arg, 0)));
3420 /* Return a simplified tree node for the truth-negation of ARG. This
3421 never alters ARG itself. We assume that ARG is an operation that
3422 returns a truth value (0 or 1).
3424 FIXME: one would think we would fold the result, but it causes
3425 problems with the dominator optimizer. */
3428 invert_truthvalue (tree arg)
3432 if (TREE_CODE (arg) == ERROR_MARK)
3435 tem = fold_truth_not_expr (arg);
3437 tem = build1 (TRUTH_NOT_EXPR, TREE_TYPE (arg), arg);
3442 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
3443 operands are another bit-wise operation with a common input. If so,
3444 distribute the bit operations to save an operation and possibly two if
3445 constants are involved. For example, convert
3446 (A | B) & (A | C) into A | (B & C)
3447 Further simplification will occur if B and C are constants.
3449 If this optimization cannot be done, 0 will be returned. */
3452 distribute_bit_expr (enum tree_code code, tree type, tree arg0, tree arg1)
3457 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3458 || TREE_CODE (arg0) == code
3459 || (TREE_CODE (arg0) != BIT_AND_EXPR
3460 && TREE_CODE (arg0) != BIT_IOR_EXPR))
3463 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
3465 common = TREE_OPERAND (arg0, 0);
3466 left = TREE_OPERAND (arg0, 1);
3467 right = TREE_OPERAND (arg1, 1);
3469 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
3471 common = TREE_OPERAND (arg0, 0);
3472 left = TREE_OPERAND (arg0, 1);
3473 right = TREE_OPERAND (arg1, 0);
3475 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
3477 common = TREE_OPERAND (arg0, 1);
3478 left = TREE_OPERAND (arg0, 0);
3479 right = TREE_OPERAND (arg1, 1);
3481 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
3483 common = TREE_OPERAND (arg0, 1);
3484 left = TREE_OPERAND (arg0, 0);
3485 right = TREE_OPERAND (arg1, 0);
3490 return fold_build2 (TREE_CODE (arg0), type, common,
3491 fold_build2 (code, type, left, right));
3494 /* Knowing that ARG0 and ARG1 are both RDIV_EXPRs, simplify a binary operation
3495 with code CODE. This optimization is unsafe. */
3497 distribute_real_division (enum tree_code code, tree type, tree arg0, tree arg1)
3499 bool mul0 = TREE_CODE (arg0) == MULT_EXPR;
3500 bool mul1 = TREE_CODE (arg1) == MULT_EXPR;
3502 /* (A / C) +- (B / C) -> (A +- B) / C. */
3504 && operand_equal_p (TREE_OPERAND (arg0, 1),
3505 TREE_OPERAND (arg1, 1), 0))
3506 return fold_build2 (mul0 ? MULT_EXPR : RDIV_EXPR, type,
3507 fold_build2 (code, type,
3508 TREE_OPERAND (arg0, 0),
3509 TREE_OPERAND (arg1, 0)),
3510 TREE_OPERAND (arg0, 1));
3512 /* (A / C1) +- (A / C2) -> A * (1 / C1 +- 1 / C2). */
3513 if (operand_equal_p (TREE_OPERAND (arg0, 0),
3514 TREE_OPERAND (arg1, 0), 0)
3515 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
3516 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
3518 REAL_VALUE_TYPE r0, r1;
3519 r0 = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
3520 r1 = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
3522 real_arithmetic (&r0, RDIV_EXPR, &dconst1, &r0);
3524 real_arithmetic (&r1, RDIV_EXPR, &dconst1, &r1);
3525 real_arithmetic (&r0, code, &r0, &r1);
3526 return fold_build2 (MULT_EXPR, type,
3527 TREE_OPERAND (arg0, 0),
3528 build_real (type, r0));
3534 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
3535 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
3538 make_bit_field_ref (tree inner, tree type, int bitsize, int bitpos,
3545 tree size = TYPE_SIZE (TREE_TYPE (inner));
3546 if ((INTEGRAL_TYPE_P (TREE_TYPE (inner))
3547 || POINTER_TYPE_P (TREE_TYPE (inner)))
3548 && host_integerp (size, 0)
3549 && tree_low_cst (size, 0) == bitsize)
3550 return fold_convert (type, inner);
3553 result = build3 (BIT_FIELD_REF, type, inner,
3554 size_int (bitsize), bitsize_int (bitpos));
3556 BIT_FIELD_REF_UNSIGNED (result) = unsignedp;
3561 /* Optimize a bit-field compare.
3563 There are two cases: First is a compare against a constant and the
3564 second is a comparison of two items where the fields are at the same
3565 bit position relative to the start of a chunk (byte, halfword, word)
3566 large enough to contain it. In these cases we can avoid the shift
3567 implicit in bitfield extractions.
3569 For constants, we emit a compare of the shifted constant with the
3570 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
3571 compared. For two fields at the same position, we do the ANDs with the
3572 similar mask and compare the result of the ANDs.
3574 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
3575 COMPARE_TYPE is the type of the comparison, and LHS and RHS
3576 are the left and right operands of the comparison, respectively.
3578 If the optimization described above can be done, we return the resulting
3579 tree. Otherwise we return zero. */
3582 optimize_bit_field_compare (enum tree_code code, tree compare_type,
3585 HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
3586 tree type = TREE_TYPE (lhs);
3587 tree signed_type, unsigned_type;
3588 int const_p = TREE_CODE (rhs) == INTEGER_CST;
3589 enum machine_mode lmode, rmode, nmode;
3590 int lunsignedp, runsignedp;
3591 int lvolatilep = 0, rvolatilep = 0;
3592 tree linner, rinner = NULL_TREE;
3596 /* Get all the information about the extractions being done. If the bit size
3597 if the same as the size of the underlying object, we aren't doing an
3598 extraction at all and so can do nothing. We also don't want to
3599 do anything if the inner expression is a PLACEHOLDER_EXPR since we
3600 then will no longer be able to replace it. */
3601 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
3602 &lunsignedp, &lvolatilep, false);
3603 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
3604 || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
3609 /* If this is not a constant, we can only do something if bit positions,
3610 sizes, and signedness are the same. */
3611 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
3612 &runsignedp, &rvolatilep, false);
3614 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
3615 || lunsignedp != runsignedp || offset != 0
3616 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
3620 /* See if we can find a mode to refer to this field. We should be able to,
3621 but fail if we can't. */
3622 nmode = get_best_mode (lbitsize, lbitpos,
3623 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
3624 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
3625 TYPE_ALIGN (TREE_TYPE (rinner))),
3626 word_mode, lvolatilep || rvolatilep);
3627 if (nmode == VOIDmode)
3630 /* Set signed and unsigned types of the precision of this mode for the
3632 signed_type = lang_hooks.types.type_for_mode (nmode, 0);
3633 unsigned_type = lang_hooks.types.type_for_mode (nmode, 1);
3635 /* Compute the bit position and size for the new reference and our offset
3636 within it. If the new reference is the same size as the original, we
3637 won't optimize anything, so return zero. */
3638 nbitsize = GET_MODE_BITSIZE (nmode);
3639 nbitpos = lbitpos & ~ (nbitsize - 1);
3641 if (nbitsize == lbitsize)
3644 if (BYTES_BIG_ENDIAN)
3645 lbitpos = nbitsize - lbitsize - lbitpos;
3647 /* Make the mask to be used against the extracted field. */
3648 mask = build_int_cst_type (unsigned_type, -1);
3649 mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
3650 mask = const_binop (RSHIFT_EXPR, mask,
3651 size_int (nbitsize - lbitsize - lbitpos), 0);
3654 /* If not comparing with constant, just rework the comparison
3656 return fold_build2 (code, compare_type,
3657 fold_build2 (BIT_AND_EXPR, unsigned_type,
3658 make_bit_field_ref (linner,
3663 fold_build2 (BIT_AND_EXPR, unsigned_type,
3664 make_bit_field_ref (rinner,
3670 /* Otherwise, we are handling the constant case. See if the constant is too
3671 big for the field. Warn and return a tree of for 0 (false) if so. We do
3672 this not only for its own sake, but to avoid having to test for this
3673 error case below. If we didn't, we might generate wrong code.
3675 For unsigned fields, the constant shifted right by the field length should
3676 be all zero. For signed fields, the high-order bits should agree with
3681 if (! integer_zerop (const_binop (RSHIFT_EXPR,
3682 fold_convert (unsigned_type, rhs),
3683 size_int (lbitsize), 0)))
3685 warning (0, "comparison is always %d due to width of bit-field",
3687 return constant_boolean_node (code == NE_EXPR, compare_type);
3692 tree tem = const_binop (RSHIFT_EXPR, fold_convert (signed_type, rhs),
3693 size_int (lbitsize - 1), 0);
3694 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
3696 warning (0, "comparison is always %d due to width of bit-field",
3698 return constant_boolean_node (code == NE_EXPR, compare_type);
3702 /* Single-bit compares should always be against zero. */
3703 if (lbitsize == 1 && ! integer_zerop (rhs))
3705 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
3706 rhs = build_int_cst (type, 0);
3709 /* Make a new bitfield reference, shift the constant over the
3710 appropriate number of bits and mask it with the computed mask
3711 (in case this was a signed field). If we changed it, make a new one. */
3712 lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1);
3715 TREE_SIDE_EFFECTS (lhs) = 1;
3716 TREE_THIS_VOLATILE (lhs) = 1;
3719 rhs = const_binop (BIT_AND_EXPR,
3720 const_binop (LSHIFT_EXPR,
3721 fold_convert (unsigned_type, rhs),
3722 size_int (lbitpos), 0),
3725 return build2 (code, compare_type,
3726 build2 (BIT_AND_EXPR, unsigned_type, lhs, mask),
3730 /* Subroutine for fold_truthop: decode a field reference.
3732 If EXP is a comparison reference, we return the innermost reference.
3734 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
3735 set to the starting bit number.
3737 If the innermost field can be completely contained in a mode-sized
3738 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
3740 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
3741 otherwise it is not changed.
3743 *PUNSIGNEDP is set to the signedness of the field.
3745 *PMASK is set to the mask used. This is either contained in a
3746 BIT_AND_EXPR or derived from the width of the field.
3748 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
3750 Return 0 if this is not a component reference or is one that we can't
3751 do anything with. */
3754 decode_field_reference (tree exp, HOST_WIDE_INT *pbitsize,
3755 HOST_WIDE_INT *pbitpos, enum machine_mode *pmode,
3756 int *punsignedp, int *pvolatilep,
3757 tree *pmask, tree *pand_mask)
3759 tree outer_type = 0;
3761 tree mask, inner, offset;
3763 unsigned int precision;
3765 /* All the optimizations using this function assume integer fields.
3766 There are problems with FP fields since the type_for_size call
3767 below can fail for, e.g., XFmode. */
3768 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
3771 /* We are interested in the bare arrangement of bits, so strip everything
3772 that doesn't affect the machine mode. However, record the type of the
3773 outermost expression if it may matter below. */
3774 if (TREE_CODE (exp) == NOP_EXPR
3775 || TREE_CODE (exp) == CONVERT_EXPR
3776 || TREE_CODE (exp) == NON_LVALUE_EXPR)
3777 outer_type = TREE_TYPE (exp);
3780 if (TREE_CODE (exp) == BIT_AND_EXPR)
3782 and_mask = TREE_OPERAND (exp, 1);
3783 exp = TREE_OPERAND (exp, 0);
3784 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
3785 if (TREE_CODE (and_mask) != INTEGER_CST)
3789 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
3790 punsignedp, pvolatilep, false);
3791 if ((inner == exp && and_mask == 0)
3792 || *pbitsize < 0 || offset != 0
3793 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
3796 /* If the number of bits in the reference is the same as the bitsize of
3797 the outer type, then the outer type gives the signedness. Otherwise
3798 (in case of a small bitfield) the signedness is unchanged. */
3799 if (outer_type && *pbitsize == TYPE_PRECISION (outer_type))
3800 *punsignedp = TYPE_UNSIGNED (outer_type);
3802 /* Compute the mask to access the bitfield. */
3803 unsigned_type = lang_hooks.types.type_for_size (*pbitsize, 1);
3804 precision = TYPE_PRECISION (unsigned_type);
3806 mask = build_int_cst_type (unsigned_type, -1);
3808 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3809 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3811 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
3813 mask = fold_build2 (BIT_AND_EXPR, unsigned_type,
3814 fold_convert (unsigned_type, and_mask), mask);
3817 *pand_mask = and_mask;
3821 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
3825 all_ones_mask_p (tree mask, int size)
3827 tree type = TREE_TYPE (mask);
3828 unsigned int precision = TYPE_PRECISION (type);
3831 tmask = build_int_cst_type (lang_hooks.types.signed_type (type), -1);
3834 tree_int_cst_equal (mask,
3835 const_binop (RSHIFT_EXPR,
3836 const_binop (LSHIFT_EXPR, tmask,
3837 size_int (precision - size),
3839 size_int (precision - size), 0));
3842 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
3843 represents the sign bit of EXP's type. If EXP represents a sign
3844 or zero extension, also test VAL against the unextended type.
3845 The return value is the (sub)expression whose sign bit is VAL,
3846 or NULL_TREE otherwise. */
3849 sign_bit_p (tree exp, tree val)
3851 unsigned HOST_WIDE_INT mask_lo, lo;
3852 HOST_WIDE_INT mask_hi, hi;
3856 /* Tree EXP must have an integral type. */
3857 t = TREE_TYPE (exp);
3858 if (! INTEGRAL_TYPE_P (t))
3861 /* Tree VAL must be an integer constant. */
3862 if (TREE_CODE (val) != INTEGER_CST
3863 || TREE_OVERFLOW (val))
3866 width = TYPE_PRECISION (t);
3867 if (width > HOST_BITS_PER_WIDE_INT)
3869 hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1);
3872 mask_hi = ((unsigned HOST_WIDE_INT) -1
3873 >> (2 * HOST_BITS_PER_WIDE_INT - width));
3879 lo = (unsigned HOST_WIDE_INT) 1 << (width - 1);
3882 mask_lo = ((unsigned HOST_WIDE_INT) -1
3883 >> (HOST_BITS_PER_WIDE_INT - width));
3886 /* We mask off those bits beyond TREE_TYPE (exp) so that we can
3887 treat VAL as if it were unsigned. */
3888 if ((TREE_INT_CST_HIGH (val) & mask_hi) == hi
3889 && (TREE_INT_CST_LOW (val) & mask_lo) == lo)
3892 /* Handle extension from a narrower type. */
3893 if (TREE_CODE (exp) == NOP_EXPR
3894 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width)
3895 return sign_bit_p (TREE_OPERAND (exp, 0), val);
3900 /* Subroutine for fold_truthop: determine if an operand is simple enough
3901 to be evaluated unconditionally. */
3904 simple_operand_p (tree exp)
3906 /* Strip any conversions that don't change the machine mode. */
3909 return (CONSTANT_CLASS_P (exp)
3910 || TREE_CODE (exp) == SSA_NAME
3912 && ! TREE_ADDRESSABLE (exp)
3913 && ! TREE_THIS_VOLATILE (exp)
3914 && ! DECL_NONLOCAL (exp)
3915 /* Don't regard global variables as simple. They may be
3916 allocated in ways unknown to the compiler (shared memory,
3917 #pragma weak, etc). */
3918 && ! TREE_PUBLIC (exp)
3919 && ! DECL_EXTERNAL (exp)
3920 /* Loading a static variable is unduly expensive, but global
3921 registers aren't expensive. */
3922 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
3925 /* The following functions are subroutines to fold_range_test and allow it to
3926 try to change a logical combination of comparisons into a range test.
3929 X == 2 || X == 3 || X == 4 || X == 5
3933 (unsigned) (X - 2) <= 3
3935 We describe each set of comparisons as being either inside or outside
3936 a range, using a variable named like IN_P, and then describe the
3937 range with a lower and upper bound. If one of the bounds is omitted,
3938 it represents either the highest or lowest value of the type.
3940 In the comments below, we represent a range by two numbers in brackets
3941 preceded by a "+" to designate being inside that range, or a "-" to
3942 designate being outside that range, so the condition can be inverted by
3943 flipping the prefix. An omitted bound is represented by a "-". For
3944 example, "- [-, 10]" means being outside the range starting at the lowest
3945 possible value and ending at 10, in other words, being greater than 10.
3946 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
3949 We set up things so that the missing bounds are handled in a consistent
3950 manner so neither a missing bound nor "true" and "false" need to be
3951 handled using a special case. */
3953 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
3954 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
3955 and UPPER1_P are nonzero if the respective argument is an upper bound
3956 and zero for a lower. TYPE, if nonzero, is the type of the result; it
3957 must be specified for a comparison. ARG1 will be converted to ARG0's
3958 type if both are specified. */
3961 range_binop (enum tree_code code, tree type, tree arg0, int upper0_p,
3962 tree arg1, int upper1_p)
3968 /* If neither arg represents infinity, do the normal operation.
3969 Else, if not a comparison, return infinity. Else handle the special
3970 comparison rules. Note that most of the cases below won't occur, but
3971 are handled for consistency. */
3973 if (arg0 != 0 && arg1 != 0)
3975 tem = fold_build2 (code, type != 0 ? type : TREE_TYPE (arg0),
3976 arg0, fold_convert (TREE_TYPE (arg0), arg1));
3978 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
3981 if (TREE_CODE_CLASS (code) != tcc_comparison)
3984 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
3985 for neither. In real maths, we cannot assume open ended ranges are
3986 the same. But, this is computer arithmetic, where numbers are finite.
3987 We can therefore make the transformation of any unbounded range with
3988 the value Z, Z being greater than any representable number. This permits
3989 us to treat unbounded ranges as equal. */
3990 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
3991 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
3995 result = sgn0 == sgn1;
3998 result = sgn0 != sgn1;
4001 result = sgn0 < sgn1;
4004 result = sgn0 <= sgn1;
4007 result = sgn0 > sgn1;
4010 result = sgn0 >= sgn1;
4016 return constant_boolean_node (result, type);
4019 /* Given EXP, a logical expression, set the range it is testing into
4020 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
4021 actually being tested. *PLOW and *PHIGH will be made of the same
4022 type as the returned expression. If EXP is not a comparison, we
4023 will most likely not be returning a useful value and range. Set
4024 *STRICT_OVERFLOW_P to true if the return value is only valid
4025 because signed overflow is undefined; otherwise, do not change
4026 *STRICT_OVERFLOW_P. */
4029 make_range (tree exp, int *pin_p, tree *plow, tree *phigh,
4030 bool *strict_overflow_p)
4032 enum tree_code code;
4033 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
4034 tree exp_type = NULL_TREE, arg0_type = NULL_TREE;
4036 tree low, high, n_low, n_high;
4038 /* Start with simply saying "EXP != 0" and then look at the code of EXP
4039 and see if we can refine the range. Some of the cases below may not
4040 happen, but it doesn't seem worth worrying about this. We "continue"
4041 the outer loop when we've changed something; otherwise we "break"
4042 the switch, which will "break" the while. */
4045 low = high = build_int_cst (TREE_TYPE (exp), 0);
4049 code = TREE_CODE (exp);
4050 exp_type = TREE_TYPE (exp);
4052 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
4054 if (TREE_OPERAND_LENGTH (exp) > 0)
4055 arg0 = TREE_OPERAND (exp, 0);
4056 if (TREE_CODE_CLASS (code) == tcc_comparison
4057 || TREE_CODE_CLASS (code) == tcc_unary
4058 || TREE_CODE_CLASS (code) == tcc_binary)
4059 arg0_type = TREE_TYPE (arg0);
4060 if (TREE_CODE_CLASS (code) == tcc_binary
4061 || TREE_CODE_CLASS (code) == tcc_comparison
4062 || (TREE_CODE_CLASS (code) == tcc_expression
4063 && TREE_OPERAND_LENGTH (exp) > 1))
4064 arg1 = TREE_OPERAND (exp, 1);
4069 case TRUTH_NOT_EXPR:
4070 in_p = ! in_p, exp = arg0;
4073 case EQ_EXPR: case NE_EXPR:
4074 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
4075 /* We can only do something if the range is testing for zero
4076 and if the second operand is an integer constant. Note that
4077 saying something is "in" the range we make is done by
4078 complementing IN_P since it will set in the initial case of
4079 being not equal to zero; "out" is leaving it alone. */
4080 if (low == 0 || high == 0
4081 || ! integer_zerop (low) || ! integer_zerop (high)
4082 || TREE_CODE (arg1) != INTEGER_CST)
4087 case NE_EXPR: /* - [c, c] */
4090 case EQ_EXPR: /* + [c, c] */
4091 in_p = ! in_p, low = high = arg1;
4093 case GT_EXPR: /* - [-, c] */
4094 low = 0, high = arg1;
4096 case GE_EXPR: /* + [c, -] */
4097 in_p = ! in_p, low = arg1, high = 0;
4099 case LT_EXPR: /* - [c, -] */
4100 low = arg1, high = 0;
4102 case LE_EXPR: /* + [-, c] */
4103 in_p = ! in_p, low = 0, high = arg1;
4109 /* If this is an unsigned comparison, we also know that EXP is
4110 greater than or equal to zero. We base the range tests we make
4111 on that fact, so we record it here so we can parse existing
4112 range tests. We test arg0_type since often the return type
4113 of, e.g. EQ_EXPR, is boolean. */
4114 if (TYPE_UNSIGNED (arg0_type) && (low == 0 || high == 0))
4116 if (! merge_ranges (&n_in_p, &n_low, &n_high,
4118 build_int_cst (arg0_type, 0),
4122 in_p = n_in_p, low = n_low, high = n_high;
4124 /* If the high bound is missing, but we have a nonzero low
4125 bound, reverse the range so it goes from zero to the low bound
4127 if (high == 0 && low && ! integer_zerop (low))
4130 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
4131 integer_one_node, 0);
4132 low = build_int_cst (arg0_type, 0);
4140 /* (-x) IN [a,b] -> x in [-b, -a] */
4141 n_low = range_binop (MINUS_EXPR, exp_type,
4142 build_int_cst (exp_type, 0),
4144 n_high = range_binop (MINUS_EXPR, exp_type,
4145 build_int_cst (exp_type, 0),
4147 low = n_low, high = n_high;
4153 exp = build2 (MINUS_EXPR, exp_type, negate_expr (arg0),
4154 build_int_cst (exp_type, 1));
4157 case PLUS_EXPR: case MINUS_EXPR:
4158 if (TREE_CODE (arg1) != INTEGER_CST)
4161 /* If flag_wrapv and ARG0_TYPE is signed, then we cannot
4162 move a constant to the other side. */
4163 if (!TYPE_UNSIGNED (arg0_type)
4164 && !TYPE_OVERFLOW_UNDEFINED (arg0_type))
4167 /* If EXP is signed, any overflow in the computation is undefined,
4168 so we don't worry about it so long as our computations on
4169 the bounds don't overflow. For unsigned, overflow is defined
4170 and this is exactly the right thing. */
4171 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
4172 arg0_type, low, 0, arg1, 0);
4173 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
4174 arg0_type, high, 1, arg1, 0);
4175 if ((n_low != 0 && TREE_OVERFLOW (n_low))
4176 || (n_high != 0 && TREE_OVERFLOW (n_high)))
4179 if (TYPE_OVERFLOW_UNDEFINED (arg0_type))
4180 *strict_overflow_p = true;
4182 /* Check for an unsigned range which has wrapped around the maximum
4183 value thus making n_high < n_low, and normalize it. */
4184 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
4186 low = range_binop (PLUS_EXPR, arg0_type, n_high, 0,
4187 integer_one_node, 0);
4188 high = range_binop (MINUS_EXPR, arg0_type, n_low, 0,
4189 integer_one_node, 0);
4191 /* If the range is of the form +/- [ x+1, x ], we won't
4192 be able to normalize it. But then, it represents the
4193 whole range or the empty set, so make it
4195 if (tree_int_cst_equal (n_low, low)
4196 && tree_int_cst_equal (n_high, high))
4202 low = n_low, high = n_high;
4207 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
4208 if (TYPE_PRECISION (arg0_type) > TYPE_PRECISION (exp_type))
4211 if (! INTEGRAL_TYPE_P (arg0_type)
4212 || (low != 0 && ! int_fits_type_p (low, arg0_type))
4213 || (high != 0 && ! int_fits_type_p (high, arg0_type)))
4216 n_low = low, n_high = high;
4219 n_low = fold_convert (arg0_type, n_low);
4222 n_high = fold_convert (arg0_type, n_high);
4225 /* If we're converting arg0 from an unsigned type, to exp,
4226 a signed type, we will be doing the comparison as unsigned.
4227 The tests above have already verified that LOW and HIGH
4230 So we have to ensure that we will handle large unsigned
4231 values the same way that the current signed bounds treat
4234 if (!TYPE_UNSIGNED (exp_type) && TYPE_UNSIGNED (arg0_type))
4237 tree equiv_type = lang_hooks.types.type_for_mode
4238 (TYPE_MODE (arg0_type), 1);
4240 /* A range without an upper bound is, naturally, unbounded.
4241 Since convert would have cropped a very large value, use
4242 the max value for the destination type. */
4244 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
4245 : TYPE_MAX_VALUE (arg0_type);
4247 if (TYPE_PRECISION (exp_type) == TYPE_PRECISION (arg0_type))
4248 high_positive = fold_build2 (RSHIFT_EXPR, arg0_type,
4249 fold_convert (arg0_type,
4251 build_int_cst (arg0_type, 1));
4253 /* If the low bound is specified, "and" the range with the
4254 range for which the original unsigned value will be
4258 if (! merge_ranges (&n_in_p, &n_low, &n_high,
4259 1, n_low, n_high, 1,
4260 fold_convert (arg0_type,
4265 in_p = (n_in_p == in_p);
4269 /* Otherwise, "or" the range with the range of the input
4270 that will be interpreted as negative. */
4271 if (! merge_ranges (&n_in_p, &n_low, &n_high,
4272 0, n_low, n_high, 1,
4273 fold_convert (arg0_type,
4278 in_p = (in_p != n_in_p);
4283 low = n_low, high = n_high;
4293 /* If EXP is a constant, we can evaluate whether this is true or false. */
4294 if (TREE_CODE (exp) == INTEGER_CST)
4296 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
4298 && integer_onep (range_binop (LE_EXPR, integer_type_node,
4304 *pin_p = in_p, *plow = low, *phigh = high;
4308 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
4309 type, TYPE, return an expression to test if EXP is in (or out of, depending
4310 on IN_P) the range. Return 0 if the test couldn't be created. */
4313 build_range_check (tree type, tree exp, int in_p, tree low, tree high)
4315 tree etype = TREE_TYPE (exp);
4318 #ifdef HAVE_canonicalize_funcptr_for_compare
4319 /* Disable this optimization for function pointer expressions
4320 on targets that require function pointer canonicalization. */
4321 if (HAVE_canonicalize_funcptr_for_compare
4322 && TREE_CODE (etype) == POINTER_TYPE
4323 && TREE_CODE (TREE_TYPE (etype)) == FUNCTION_TYPE)
4329 value = build_range_check (type, exp, 1, low, high);
4331 return invert_truthvalue (value);
4336 if (low == 0 && high == 0)
4337 return build_int_cst (type, 1);
4340 return fold_build2 (LE_EXPR, type, exp,
4341 fold_convert (etype, high));
4344 return fold_build2 (GE_EXPR, type, exp,
4345 fold_convert (etype, low));
4347 if (operand_equal_p (low, high, 0))
4348 return fold_build2 (EQ_EXPR, type, exp,
4349 fold_convert (etype, low));
4351 if (integer_zerop (low))
4353 if (! TYPE_UNSIGNED (etype))
4355 etype = lang_hooks.types.unsigned_type (etype);
4356 high = fold_convert (etype, high);
4357 exp = fold_convert (etype, exp);
4359 return build_range_check (type, exp, 1, 0, high);
4362 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
4363 if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST)
4365 unsigned HOST_WIDE_INT lo;
4369 prec = TYPE_PRECISION (etype);
4370 if (prec <= HOST_BITS_PER_WIDE_INT)
4373 lo = ((unsigned HOST_WIDE_INT) 1 << (prec - 1)) - 1;
4377 hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1;
4378 lo = (unsigned HOST_WIDE_INT) -1;
4381 if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo)
4383 if (TYPE_UNSIGNED (etype))
4385 etype = lang_hooks.types.signed_type (etype);
4386 exp = fold_convert (etype, exp);
4388 return fold_build2 (GT_EXPR, type, exp,
4389 build_int_cst (etype, 0));
4393 /* Optimize (c>=low) && (c<=high) into (c-low>=0) && (c-low<=high-low).
4394 This requires wrap-around arithmetics for the type of the expression. */
4395 switch (TREE_CODE (etype))
4398 /* There is no requirement that LOW be within the range of ETYPE
4399 if the latter is a subtype. It must, however, be within the base
4400 type of ETYPE. So be sure we do the subtraction in that type. */
4401 if (TREE_TYPE (etype))
4402 etype = TREE_TYPE (etype);
4407 etype = lang_hooks.types.type_for_size (TYPE_PRECISION (etype),
4408 TYPE_UNSIGNED (etype));
4415 /* If we don't have wrap-around arithmetics upfront, try to force it. */
4416 if (TREE_CODE (etype) == INTEGER_TYPE
4417 && !TYPE_OVERFLOW_WRAPS (etype))
4419 tree utype, minv, maxv;
4421 /* Check if (unsigned) INT_MAX + 1 == (unsigned) INT_MIN
4422 for the type in question, as we rely on this here. */
4423 utype = lang_hooks.types.unsigned_type (etype);
4424 maxv = fold_convert (utype, TYPE_MAX_VALUE (etype));
4425 maxv = range_binop (PLUS_EXPR, NULL_TREE, maxv, 1,
4426 integer_one_node, 1);
4427 minv = fold_convert (utype, TYPE_MIN_VALUE (etype));
4429 if (integer_zerop (range_binop (NE_EXPR, integer_type_node,
4436 high = fold_convert (etype, high);
4437 low = fold_convert (etype, low);
4438 exp = fold_convert (etype, exp);
4440 value = const_binop (MINUS_EXPR, high, low, 0);
4442 if (value != 0 && !TREE_OVERFLOW (value))
4443 return build_range_check (type,
4444 fold_build2 (MINUS_EXPR, etype, exp, low),
4445 1, build_int_cst (etype, 0), value);
4450 /* Return the predecessor of VAL in its type, handling the infinite case. */
4453 range_predecessor (tree val)
4455 tree type = TREE_TYPE (val);
4457 if (INTEGRAL_TYPE_P (type)
4458 && operand_equal_p (val, TYPE_MIN_VALUE (type), 0))
4461 return range_binop (MINUS_EXPR, NULL_TREE, val, 0, integer_one_node, 0);
4464 /* Return the successor of VAL in its type, handling the infinite case. */
4467 range_successor (tree val)
4469 tree type = TREE_TYPE (val);
4471 if (INTEGRAL_TYPE_P (type)
4472 && operand_equal_p (val, TYPE_MAX_VALUE (type), 0))
4475 return range_binop (PLUS_EXPR, NULL_TREE, val, 0, integer_one_node, 0);
4478 /* Given two ranges, see if we can merge them into one. Return 1 if we
4479 can, 0 if we can't. Set the output range into the specified parameters. */
4482 merge_ranges (int *pin_p, tree *plow, tree *phigh, int in0_p, tree low0,
4483 tree high0, int in1_p, tree low1, tree high1)
4491 int lowequal = ((low0 == 0 && low1 == 0)
4492 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
4493 low0, 0, low1, 0)));
4494 int highequal = ((high0 == 0 && high1 == 0)
4495 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
4496 high0, 1, high1, 1)));
4498 /* Make range 0 be the range that starts first, or ends last if they
4499 start at the same value. Swap them if it isn't. */
4500 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
4503 && integer_onep (range_binop (GT_EXPR, integer_type_node,
4504 high1, 1, high0, 1))))
4506 temp = in0_p, in0_p = in1_p, in1_p = temp;
4507 tem = low0, low0 = low1, low1 = tem;
4508 tem = high0, high0 = high1, high1 = tem;
4511 /* Now flag two cases, whether the ranges are disjoint or whether the
4512 second range is totally subsumed in the first. Note that the tests
4513 below are simplified by the ones above. */
4514 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
4515 high0, 1, low1, 0));
4516 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
4517 high1, 1, high0, 1));
4519 /* We now have four cases, depending on whether we are including or
4520 excluding the two ranges. */
4523 /* If they don't overlap, the result is false. If the second range
4524 is a subset it is the result. Otherwise, the range is from the start
4525 of the second to the end of the first. */
4527 in_p = 0, low = high = 0;
4529 in_p = 1, low = low1, high = high1;
4531 in_p = 1, low = low1, high = high0;
4534 else if (in0_p && ! in1_p)
4536 /* If they don't overlap, the result is the first range. If they are
4537 equal, the result is false. If the second range is a subset of the
4538 first, and the ranges begin at the same place, we go from just after
4539 the end of the second range to the end of the first. If the second
4540 range is not a subset of the first, or if it is a subset and both
4541 ranges end at the same place, the range starts at the start of the
4542 first range and ends just before the second range.
4543 Otherwise, we can't describe this as a single range. */
4545 in_p = 1, low = low0, high = high0;
4546 else if (lowequal && highequal)
4547 in_p = 0, low = high = 0;
4548 else if (subset && lowequal)
4550 low = range_successor (high1);
4554 else if (! subset || highequal)
4557 high = range_predecessor (low1);
4564 else if (! in0_p && in1_p)
4566 /* If they don't overlap, the result is the second range. If the second
4567 is a subset of the first, the result is false. Otherwise,
4568 the range starts just after the first range and ends at the
4569 end of the second. */
4571 in_p = 1, low = low1, high = high1;
4572 else if (subset || highequal)
4573 in_p = 0, low = high = 0;
4576 low = range_successor (high0);
4584 /* The case where we are excluding both ranges. Here the complex case
4585 is if they don't overlap. In that case, the only time we have a
4586 range is if they are adjacent. If the second is a subset of the
4587 first, the result is the first. Otherwise, the range to exclude
4588 starts at the beginning of the first range and ends at the end of the
4592 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
4593 range_successor (high0),
4595 in_p = 0, low = low0, high = high1;
4598 /* Canonicalize - [min, x] into - [-, x]. */
4599 if (low0 && TREE_CODE (low0) == INTEGER_CST)
4600 switch (TREE_CODE (TREE_TYPE (low0)))
4603 if (TYPE_PRECISION (TREE_TYPE (low0))
4604 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (low0))))
4608 if (tree_int_cst_equal (low0,
4609 TYPE_MIN_VALUE (TREE_TYPE (low0))))
4613 if (TYPE_UNSIGNED (TREE_TYPE (low0))
4614 && integer_zerop (low0))
4621 /* Canonicalize - [x, max] into - [x, -]. */
4622 if (high1 && TREE_CODE (high1) == INTEGER_CST)
4623 switch (TREE_CODE (TREE_TYPE (high1)))
4626 if (TYPE_PRECISION (TREE_TYPE (high1))
4627 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (high1))))
4631 if (tree_int_cst_equal (high1,
4632 TYPE_MAX_VALUE (TREE_TYPE (high1))))
4636 if (TYPE_UNSIGNED (TREE_TYPE (high1))
4637 && integer_zerop (range_binop (PLUS_EXPR, NULL_TREE,
4639 integer_one_node, 1)))
4646 /* The ranges might be also adjacent between the maximum and
4647 minimum values of the given type. For
4648 - [{min,-}, x] and - [y, {max,-}] ranges where x + 1 < y
4649 return + [x + 1, y - 1]. */
4650 if (low0 == 0 && high1 == 0)
4652 low = range_successor (high0);
4653 high = range_predecessor (low1);
4654 if (low == 0 || high == 0)
4664 in_p = 0, low = low0, high = high0;
4666 in_p = 0, low = low0, high = high1;
4669 *pin_p = in_p, *plow = low, *phigh = high;
4674 /* Subroutine of fold, looking inside expressions of the form
4675 A op B ? A : C, where ARG0, ARG1 and ARG2 are the three operands
4676 of the COND_EXPR. This function is being used also to optimize
4677 A op B ? C : A, by reversing the comparison first.
4679 Return a folded expression whose code is not a COND_EXPR
4680 anymore, or NULL_TREE if no folding opportunity is found. */
4683 fold_cond_expr_with_comparison (tree type, tree arg0, tree arg1, tree arg2)
4685 enum tree_code comp_code = TREE_CODE (arg0);
4686 tree arg00 = TREE_OPERAND (arg0, 0);
4687 tree arg01 = TREE_OPERAND (arg0, 1);
4688 tree arg1_type = TREE_TYPE (arg1);
4694 /* If we have A op 0 ? A : -A, consider applying the following
4697 A == 0? A : -A same as -A
4698 A != 0? A : -A same as A
4699 A >= 0? A : -A same as abs (A)
4700 A > 0? A : -A same as abs (A)
4701 A <= 0? A : -A same as -abs (A)
4702 A < 0? A : -A same as -abs (A)
4704 None of these transformations work for modes with signed
4705 zeros. If A is +/-0, the first two transformations will
4706 change the sign of the result (from +0 to -0, or vice
4707 versa). The last four will fix the sign of the result,
4708 even though the original expressions could be positive or
4709 negative, depending on the sign of A.
4711 Note that all these transformations are correct if A is
4712 NaN, since the two alternatives (A and -A) are also NaNs. */
4713 if ((FLOAT_TYPE_P (TREE_TYPE (arg01))
4714 ? real_zerop (arg01)
4715 : integer_zerop (arg01))
4716 && ((TREE_CODE (arg2) == NEGATE_EXPR
4717 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
4718 /* In the case that A is of the form X-Y, '-A' (arg2) may
4719 have already been folded to Y-X, check for that. */
4720 || (TREE_CODE (arg1) == MINUS_EXPR
4721 && TREE_CODE (arg2) == MINUS_EXPR
4722 && operand_equal_p (TREE_OPERAND (arg1, 0),
4723 TREE_OPERAND (arg2, 1), 0)
4724 && operand_equal_p (TREE_OPERAND (arg1, 1),
4725 TREE_OPERAND (arg2, 0), 0))))
4730 tem = fold_convert (arg1_type, arg1);
4731 return pedantic_non_lvalue (fold_convert (type, negate_expr (tem)));
4734 return pedantic_non_lvalue (fold_convert (type, arg1));
4737 if (flag_trapping_math)
4742 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
4743 arg1 = fold_convert (lang_hooks.types.signed_type
4744 (TREE_TYPE (arg1)), arg1);
4745 tem = fold_build1 (ABS_EXPR, TREE_TYPE (arg1), arg1);
4746 return pedantic_non_lvalue (fold_convert (type, tem));
4749 if (flag_trapping_math)
4753 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
4754 arg1 = fold_convert (lang_hooks.types.signed_type
4755 (TREE_TYPE (arg1)), arg1);
4756 tem = fold_build1 (ABS_EXPR, TREE_TYPE (arg1), arg1);
4757 return negate_expr (fold_convert (type, tem));
4759 gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
4763 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
4764 A == 0 ? A : 0 is always 0 unless A is -0. Note that
4765 both transformations are correct when A is NaN: A != 0
4766 is then true, and A == 0 is false. */
4768 if (integer_zerop (arg01) && integer_zerop (arg2))
4770 if (comp_code == NE_EXPR)
4771 return pedantic_non_lvalue (fold_convert (type, arg1));
4772 else if (comp_code == EQ_EXPR)
4773 return build_int_cst (type, 0);
4776 /* Try some transformations of A op B ? A : B.
4778 A == B? A : B same as B
4779 A != B? A : B same as A
4780 A >= B? A : B same as max (A, B)
4781 A > B? A : B same as max (B, A)
4782 A <= B? A : B same as min (A, B)
4783 A < B? A : B same as min (B, A)
4785 As above, these transformations don't work in the presence
4786 of signed zeros. For example, if A and B are zeros of
4787 opposite sign, the first two transformations will change
4788 the sign of the result. In the last four, the original
4789 expressions give different results for (A=+0, B=-0) and
4790 (A=-0, B=+0), but the transformed expressions do not.
4792 The first two transformations are correct if either A or B
4793 is a NaN. In the first transformation, the condition will
4794 be false, and B will indeed be chosen. In the case of the
4795 second transformation, the condition A != B will be true,
4796 and A will be chosen.
4798 The conversions to max() and min() are not correct if B is
4799 a number and A is not. The conditions in the original
4800 expressions will be false, so all four give B. The min()
4801 and max() versions would give a NaN instead. */
4802 if (operand_equal_for_comparison_p (arg01, arg2, arg00)
4803 /* Avoid these transformations if the COND_EXPR may be used
4804 as an lvalue in the C++ front-end. PR c++/19199. */
4806 || (strcmp (lang_hooks.name, "GNU C++") != 0
4807 && strcmp (lang_hooks.name, "GNU Objective-C++") != 0)
4808 || ! maybe_lvalue_p (arg1)
4809 || ! maybe_lvalue_p (arg2)))
4811 tree comp_op0 = arg00;
4812 tree comp_op1 = arg01;
4813 tree comp_type = TREE_TYPE (comp_op0);
4815 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
4816 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
4826 return pedantic_non_lvalue (fold_convert (type, arg2));
4828 return pedantic_non_lvalue (fold_convert (type, arg1));
4833 /* In C++ a ?: expression can be an lvalue, so put the
4834 operand which will be used if they are equal first
4835 so that we can convert this back to the
4836 corresponding COND_EXPR. */
4837 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4839 comp_op0 = fold_convert (comp_type, comp_op0);
4840 comp_op1 = fold_convert (comp_type, comp_op1);
4841 tem = (comp_code == LE_EXPR || comp_code == UNLE_EXPR)
4842 ? fold_build2 (MIN_EXPR, comp_type, comp_op0, comp_op1)
4843 : fold_build2 (MIN_EXPR, comp_type, comp_op1, comp_op0);
4844 return pedantic_non_lvalue (fold_convert (type, tem));
4851 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4853 comp_op0 = fold_convert (comp_type, comp_op0);
4854 comp_op1 = fold_convert (comp_type, comp_op1);
4855 tem = (comp_code == GE_EXPR || comp_code == UNGE_EXPR)
4856 ? fold_build2 (MAX_EXPR, comp_type, comp_op0, comp_op1)
4857 : fold_build2 (MAX_EXPR, comp_type, comp_op1, comp_op0);
4858 return pedantic_non_lvalue (fold_convert (type, tem));
4862 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4863 return pedantic_non_lvalue (fold_convert (type, arg2));
4866 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4867 return pedantic_non_lvalue (fold_convert (type, arg1));
4870 gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
4875 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
4876 we might still be able to simplify this. For example,
4877 if C1 is one less or one more than C2, this might have started
4878 out as a MIN or MAX and been transformed by this function.
4879 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
4881 if (INTEGRAL_TYPE_P (type)
4882 && TREE_CODE (arg01) == INTEGER_CST
4883 && TREE_CODE (arg2) == INTEGER_CST)
4887 /* We can replace A with C1 in this case. */
4888 arg1 = fold_convert (type, arg01);
4889 return fold_build3 (COND_EXPR, type, arg0, arg1, arg2);
4892 /* If C1 is C2 + 1, this is min(A, C2). */
4893 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
4895 && operand_equal_p (arg01,
4896 const_binop (PLUS_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 min(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 (MIN_EXPR,
4916 /* If C1 is C2 - 1, this is max(A, C2). */
4917 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
4919 && operand_equal_p (arg01,
4920 const_binop (MINUS_EXPR, arg2,
4921 build_int_cst (type, 1), 0),
4923 return pedantic_non_lvalue (fold_build2 (MAX_EXPR,
4928 /* If C1 is C2 + 1, this is max(A, C2). */
4929 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
4931 && operand_equal_p (arg01,
4932 const_binop (PLUS_EXPR, arg2,
4933 build_int_cst (type, 1), 0),
4935 return pedantic_non_lvalue (fold_build2 (MAX_EXPR,
4949 #ifndef LOGICAL_OP_NON_SHORT_CIRCUIT
4950 #define LOGICAL_OP_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
4953 /* EXP is some logical combination of boolean tests. See if we can
4954 merge it into some range test. Return the new tree if so. */
4957 fold_range_test (enum tree_code code, tree type, tree op0, tree op1)
4959 int or_op = (code == TRUTH_ORIF_EXPR
4960 || code == TRUTH_OR_EXPR);
4961 int in0_p, in1_p, in_p;
4962 tree low0, low1, low, high0, high1, high;
4963 bool strict_overflow_p = false;
4964 tree lhs = make_range (op0, &in0_p, &low0, &high0, &strict_overflow_p);
4965 tree rhs = make_range (op1, &in1_p, &low1, &high1, &strict_overflow_p);
4967 const char * const warnmsg = G_("assuming signed overflow does not occur "
4968 "when simplifying range test");
4970 /* If this is an OR operation, invert both sides; we will invert
4971 again at the end. */
4973 in0_p = ! in0_p, in1_p = ! in1_p;
4975 /* If both expressions are the same, if we can merge the ranges, and we
4976 can build the range test, return it or it inverted. If one of the
4977 ranges is always true or always false, consider it to be the same
4978 expression as the other. */
4979 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
4980 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
4982 && 0 != (tem = (build_range_check (type,
4984 : rhs != 0 ? rhs : integer_zero_node,
4987 if (strict_overflow_p)
4988 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
4989 return or_op ? invert_truthvalue (tem) : tem;
4992 /* On machines where the branch cost is expensive, if this is a
4993 short-circuited branch and the underlying object on both sides
4994 is the same, make a non-short-circuit operation. */
4995 else if (LOGICAL_OP_NON_SHORT_CIRCUIT
4996 && lhs != 0 && rhs != 0
4997 && (code == TRUTH_ANDIF_EXPR
4998 || code == TRUTH_ORIF_EXPR)
4999 && operand_equal_p (lhs, rhs, 0))
5001 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
5002 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
5003 which cases we can't do this. */
5004 if (simple_operand_p (lhs))
5005 return build2 (code == TRUTH_ANDIF_EXPR
5006 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
5009 else if (lang_hooks.decls.global_bindings_p () == 0
5010 && ! CONTAINS_PLACEHOLDER_P (lhs))
5012 tree common = save_expr (lhs);
5014 if (0 != (lhs = build_range_check (type, common,
5015 or_op ? ! in0_p : in0_p,
5017 && (0 != (rhs = build_range_check (type, common,
5018 or_op ? ! in1_p : in1_p,
5021 if (strict_overflow_p)
5022 fold_overflow_warning (warnmsg,
5023 WARN_STRICT_OVERFLOW_COMPARISON);
5024 return build2 (code == TRUTH_ANDIF_EXPR
5025 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
5034 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
5035 bit value. Arrange things so the extra bits will be set to zero if and
5036 only if C is signed-extended to its full width. If MASK is nonzero,
5037 it is an INTEGER_CST that should be AND'ed with the extra bits. */
5040 unextend (tree c, int p, int unsignedp, tree mask)
5042 tree type = TREE_TYPE (c);
5043 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
5046 if (p == modesize || unsignedp)
5049 /* We work by getting just the sign bit into the low-order bit, then
5050 into the high-order bit, then sign-extend. We then XOR that value
5052 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
5053 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
5055 /* We must use a signed type in order to get an arithmetic right shift.
5056 However, we must also avoid introducing accidental overflows, so that
5057 a subsequent call to integer_zerop will work. Hence we must
5058 do the type conversion here. At this point, the constant is either
5059 zero or one, and the conversion to a signed type can never overflow.
5060 We could get an overflow if this conversion is done anywhere else. */
5061 if (TYPE_UNSIGNED (type))
5062 temp = fold_convert (lang_hooks.types.signed_type (type), temp);
5064 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
5065 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
5067 temp = const_binop (BIT_AND_EXPR, temp,
5068 fold_convert (TREE_TYPE (c), mask), 0);
5069 /* If necessary, convert the type back to match the type of C. */
5070 if (TYPE_UNSIGNED (type))
5071 temp = fold_convert (type, temp);
5073 return fold_convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
5076 /* Find ways of folding logical expressions of LHS and RHS:
5077 Try to merge two comparisons to the same innermost item.
5078 Look for range tests like "ch >= '0' && ch <= '9'".
5079 Look for combinations of simple terms on machines with expensive branches
5080 and evaluate the RHS unconditionally.
5082 For example, if we have p->a == 2 && p->b == 4 and we can make an
5083 object large enough to span both A and B, we can do this with a comparison
5084 against the object ANDed with the a mask.
5086 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
5087 operations to do this with one comparison.
5089 We check for both normal comparisons and the BIT_AND_EXPRs made this by
5090 function and the one above.
5092 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
5093 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
5095 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
5098 We return the simplified tree or 0 if no optimization is possible. */
5101 fold_truthop (enum tree_code code, tree truth_type, tree lhs, tree rhs)
5103 /* If this is the "or" of two comparisons, we can do something if
5104 the comparisons are NE_EXPR. If this is the "and", we can do something
5105 if the comparisons are EQ_EXPR. I.e.,
5106 (a->b == 2 && a->c == 4) can become (a->new == NEW).
5108 WANTED_CODE is this operation code. For single bit fields, we can
5109 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
5110 comparison for one-bit fields. */
5112 enum tree_code wanted_code;
5113 enum tree_code lcode, rcode;
5114 tree ll_arg, lr_arg, rl_arg, rr_arg;
5115 tree ll_inner, lr_inner, rl_inner, rr_inner;
5116 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
5117 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
5118 HOST_WIDE_INT xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
5119 HOST_WIDE_INT lnbitsize, lnbitpos, rnbitsize, rnbitpos;
5120 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
5121 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
5122 enum machine_mode lnmode, rnmode;
5123 tree ll_mask, lr_mask, rl_mask, rr_mask;
5124 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
5125 tree l_const, r_const;
5126 tree lntype, rntype, result;
5127 int first_bit, end_bit;
5129 tree orig_lhs = lhs, orig_rhs = rhs;
5130 enum tree_code orig_code = code;
5132 /* Start by getting the comparison codes. Fail if anything is volatile.
5133 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
5134 it were surrounded with a NE_EXPR. */
5136 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
5139 lcode = TREE_CODE (lhs);
5140 rcode = TREE_CODE (rhs);
5142 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
5144 lhs = build2 (NE_EXPR, truth_type, lhs,
5145 build_int_cst (TREE_TYPE (lhs), 0));
5149 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
5151 rhs = build2 (NE_EXPR, truth_type, rhs,
5152 build_int_cst (TREE_TYPE (rhs), 0));
5156 if (TREE_CODE_CLASS (lcode) != tcc_comparison
5157 || TREE_CODE_CLASS (rcode) != tcc_comparison)
5160 ll_arg = TREE_OPERAND (lhs, 0);
5161 lr_arg = TREE_OPERAND (lhs, 1);
5162 rl_arg = TREE_OPERAND (rhs, 0);
5163 rr_arg = TREE_OPERAND (rhs, 1);
5165 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
5166 if (simple_operand_p (ll_arg)
5167 && simple_operand_p (lr_arg))
5170 if (operand_equal_p (ll_arg, rl_arg, 0)
5171 && operand_equal_p (lr_arg, rr_arg, 0))
5173 result = combine_comparisons (code, lcode, rcode,
5174 truth_type, ll_arg, lr_arg);
5178 else if (operand_equal_p (ll_arg, rr_arg, 0)
5179 && operand_equal_p (lr_arg, rl_arg, 0))
5181 result = combine_comparisons (code, lcode,
5182 swap_tree_comparison (rcode),
5183 truth_type, ll_arg, lr_arg);
5189 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
5190 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
5192 /* If the RHS can be evaluated unconditionally and its operands are
5193 simple, it wins to evaluate the RHS unconditionally on machines
5194 with expensive branches. In this case, this isn't a comparison
5195 that can be merged. Avoid doing this if the RHS is a floating-point
5196 comparison since those can trap. */
5198 if (BRANCH_COST >= 2
5199 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
5200 && simple_operand_p (rl_arg)
5201 && simple_operand_p (rr_arg))
5203 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
5204 if (code == TRUTH_OR_EXPR
5205 && lcode == NE_EXPR && integer_zerop (lr_arg)
5206 && rcode == NE_EXPR && integer_zerop (rr_arg)
5207 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
5208 return build2 (NE_EXPR, truth_type,
5209 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
5211 build_int_cst (TREE_TYPE (ll_arg), 0));
5213 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
5214 if (code == TRUTH_AND_EXPR
5215 && lcode == EQ_EXPR && integer_zerop (lr_arg)
5216 && rcode == EQ_EXPR && integer_zerop (rr_arg)
5217 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
5218 return build2 (EQ_EXPR, truth_type,
5219 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
5221 build_int_cst (TREE_TYPE (ll_arg), 0));
5223 if (LOGICAL_OP_NON_SHORT_CIRCUIT)
5225 if (code != orig_code || lhs != orig_lhs || rhs != orig_rhs)
5226 return build2 (code, truth_type, lhs, rhs);
5231 /* See if the comparisons can be merged. Then get all the parameters for
5234 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
5235 || (rcode != EQ_EXPR && rcode != NE_EXPR))
5239 ll_inner = decode_field_reference (ll_arg,
5240 &ll_bitsize, &ll_bitpos, &ll_mode,
5241 &ll_unsignedp, &volatilep, &ll_mask,
5243 lr_inner = decode_field_reference (lr_arg,
5244 &lr_bitsize, &lr_bitpos, &lr_mode,
5245 &lr_unsignedp, &volatilep, &lr_mask,
5247 rl_inner = decode_field_reference (rl_arg,
5248 &rl_bitsize, &rl_bitpos, &rl_mode,
5249 &rl_unsignedp, &volatilep, &rl_mask,
5251 rr_inner = decode_field_reference (rr_arg,
5252 &rr_bitsize, &rr_bitpos, &rr_mode,
5253 &rr_unsignedp, &volatilep, &rr_mask,
5256 /* It must be true that the inner operation on the lhs of each
5257 comparison must be the same if we are to be able to do anything.
5258 Then see if we have constants. If not, the same must be true for
5260 if (volatilep || ll_inner == 0 || rl_inner == 0
5261 || ! operand_equal_p (ll_inner, rl_inner, 0))
5264 if (TREE_CODE (lr_arg) == INTEGER_CST
5265 && TREE_CODE (rr_arg) == INTEGER_CST)
5266 l_const = lr_arg, r_const = rr_arg;
5267 else if (lr_inner == 0 || rr_inner == 0
5268 || ! operand_equal_p (lr_inner, rr_inner, 0))
5271 l_const = r_const = 0;
5273 /* If either comparison code is not correct for our logical operation,
5274 fail. However, we can convert a one-bit comparison against zero into
5275 the opposite comparison against that bit being set in the field. */
5277 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
5278 if (lcode != wanted_code)
5280 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
5282 /* Make the left operand unsigned, since we are only interested
5283 in the value of one bit. Otherwise we are doing the wrong
5292 /* This is analogous to the code for l_const above. */
5293 if (rcode != wanted_code)
5295 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
5304 /* See if we can find a mode that contains both fields being compared on
5305 the left. If we can't, fail. Otherwise, update all constants and masks
5306 to be relative to a field of that size. */
5307 first_bit = MIN (ll_bitpos, rl_bitpos);
5308 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
5309 lnmode = get_best_mode (end_bit - first_bit, first_bit,
5310 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
5312 if (lnmode == VOIDmode)
5315 lnbitsize = GET_MODE_BITSIZE (lnmode);
5316 lnbitpos = first_bit & ~ (lnbitsize - 1);
5317 lntype = lang_hooks.types.type_for_size (lnbitsize, 1);
5318 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
5320 if (BYTES_BIG_ENDIAN)
5322 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
5323 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
5326 ll_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, ll_mask),
5327 size_int (xll_bitpos), 0);
5328 rl_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, rl_mask),
5329 size_int (xrl_bitpos), 0);
5333 l_const = fold_convert (lntype, l_const);
5334 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
5335 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
5336 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
5337 fold_build1 (BIT_NOT_EXPR,
5341 warning (0, "comparison is always %d", wanted_code == NE_EXPR);
5343 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
5348 r_const = fold_convert (lntype, r_const);
5349 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
5350 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
5351 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
5352 fold_build1 (BIT_NOT_EXPR,
5356 warning (0, "comparison is always %d", wanted_code == NE_EXPR);
5358 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
5362 /* If the right sides are not constant, do the same for it. Also,
5363 disallow this optimization if a size or signedness mismatch occurs
5364 between the left and right sides. */
5367 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
5368 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
5369 /* Make sure the two fields on the right
5370 correspond to the left without being swapped. */
5371 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
5374 first_bit = MIN (lr_bitpos, rr_bitpos);
5375 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
5376 rnmode = get_best_mode (end_bit - first_bit, first_bit,
5377 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
5379 if (rnmode == VOIDmode)
5382 rnbitsize = GET_MODE_BITSIZE (rnmode);
5383 rnbitpos = first_bit & ~ (rnbitsize - 1);
5384 rntype = lang_hooks.types.type_for_size (rnbitsize, 1);
5385 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
5387 if (BYTES_BIG_ENDIAN)
5389 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
5390 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
5393 lr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, lr_mask),
5394 size_int (xlr_bitpos), 0);
5395 rr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, rr_mask),
5396 size_int (xrr_bitpos), 0);
5398 /* Make a mask that corresponds to both fields being compared.
5399 Do this for both items being compared. If the operands are the
5400 same size and the bits being compared are in the same position
5401 then we can do this by masking both and comparing the masked
5403 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
5404 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
5405 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
5407 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
5408 ll_unsignedp || rl_unsignedp);
5409 if (! all_ones_mask_p (ll_mask, lnbitsize))
5410 lhs = build2 (BIT_AND_EXPR, lntype, lhs, ll_mask);
5412 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
5413 lr_unsignedp || rr_unsignedp);
5414 if (! all_ones_mask_p (lr_mask, rnbitsize))
5415 rhs = build2 (BIT_AND_EXPR, rntype, rhs, lr_mask);
5417 return build2 (wanted_code, truth_type, lhs, rhs);
5420 /* There is still another way we can do something: If both pairs of
5421 fields being compared are adjacent, we may be able to make a wider
5422 field containing them both.
5424 Note that we still must mask the lhs/rhs expressions. Furthermore,
5425 the mask must be shifted to account for the shift done by
5426 make_bit_field_ref. */
5427 if ((ll_bitsize + ll_bitpos == rl_bitpos
5428 && lr_bitsize + lr_bitpos == rr_bitpos)
5429 || (ll_bitpos == rl_bitpos + rl_bitsize
5430 && lr_bitpos == rr_bitpos + rr_bitsize))
5434 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
5435 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
5436 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
5437 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
5439 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
5440 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
5441 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
5442 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
5444 /* Convert to the smaller type before masking out unwanted bits. */
5446 if (lntype != rntype)
5448 if (lnbitsize > rnbitsize)
5450 lhs = fold_convert (rntype, lhs);
5451 ll_mask = fold_convert (rntype, ll_mask);
5454 else if (lnbitsize < rnbitsize)
5456 rhs = fold_convert (lntype, rhs);
5457 lr_mask = fold_convert (lntype, lr_mask);
5462 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
5463 lhs = build2 (BIT_AND_EXPR, type, lhs, ll_mask);
5465 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
5466 rhs = build2 (BIT_AND_EXPR, type, rhs, lr_mask);
5468 return build2 (wanted_code, truth_type, lhs, rhs);
5474 /* Handle the case of comparisons with constants. If there is something in
5475 common between the masks, those bits of the constants must be the same.
5476 If not, the condition is always false. Test for this to avoid generating
5477 incorrect code below. */
5478 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
5479 if (! integer_zerop (result)
5480 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
5481 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
5483 if (wanted_code == NE_EXPR)
5485 warning (0, "%<or%> of unmatched not-equal tests is always 1");
5486 return constant_boolean_node (true, truth_type);
5490 warning (0, "%<and%> of mutually exclusive equal-tests is always 0");
5491 return constant_boolean_node (false, truth_type);
5495 /* Construct the expression we will return. First get the component
5496 reference we will make. Unless the mask is all ones the width of
5497 that field, perform the mask operation. Then compare with the
5499 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
5500 ll_unsignedp || rl_unsignedp);
5502 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
5503 if (! all_ones_mask_p (ll_mask, lnbitsize))
5504 result = build2 (BIT_AND_EXPR, lntype, result, ll_mask);
5506 return build2 (wanted_code, truth_type, result,
5507 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
5510 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
5514 optimize_minmax_comparison (enum tree_code code, tree type, tree op0, tree op1)
5517 enum tree_code op_code;
5518 tree comp_const = op1;
5520 int consts_equal, consts_lt;
5523 STRIP_SIGN_NOPS (arg0);
5525 op_code = TREE_CODE (arg0);
5526 minmax_const = TREE_OPERAND (arg0, 1);
5527 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
5528 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
5529 inner = TREE_OPERAND (arg0, 0);
5531 /* If something does not permit us to optimize, return the original tree. */
5532 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
5533 || TREE_CODE (comp_const) != INTEGER_CST
5534 || TREE_OVERFLOW (comp_const)
5535 || TREE_CODE (minmax_const) != INTEGER_CST
5536 || TREE_OVERFLOW (minmax_const))
5539 /* Now handle all the various comparison codes. We only handle EQ_EXPR
5540 and GT_EXPR, doing the rest with recursive calls using logical
5544 case NE_EXPR: case LT_EXPR: case LE_EXPR:
5546 tree tem = optimize_minmax_comparison (invert_tree_comparison (code, false),
5549 return invert_truthvalue (tem);
5555 fold_build2 (TRUTH_ORIF_EXPR, type,
5556 optimize_minmax_comparison
5557 (EQ_EXPR, type, arg0, comp_const),
5558 optimize_minmax_comparison
5559 (GT_EXPR, type, arg0, comp_const));
5562 if (op_code == MAX_EXPR && consts_equal)
5563 /* MAX (X, 0) == 0 -> X <= 0 */
5564 return fold_build2 (LE_EXPR, type, inner, comp_const);
5566 else if (op_code == MAX_EXPR && consts_lt)
5567 /* MAX (X, 0) == 5 -> X == 5 */
5568 return fold_build2 (EQ_EXPR, type, inner, comp_const);
5570 else if (op_code == MAX_EXPR)
5571 /* MAX (X, 0) == -1 -> false */
5572 return omit_one_operand (type, integer_zero_node, inner);
5574 else if (consts_equal)
5575 /* MIN (X, 0) == 0 -> X >= 0 */
5576 return fold_build2 (GE_EXPR, type, inner, comp_const);
5579 /* MIN (X, 0) == 5 -> false */
5580 return omit_one_operand (type, integer_zero_node, inner);
5583 /* MIN (X, 0) == -1 -> X == -1 */
5584 return fold_build2 (EQ_EXPR, type, inner, comp_const);
5587 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
5588 /* MAX (X, 0) > 0 -> X > 0
5589 MAX (X, 0) > 5 -> X > 5 */
5590 return fold_build2 (GT_EXPR, type, inner, comp_const);
5592 else if (op_code == MAX_EXPR)
5593 /* MAX (X, 0) > -1 -> true */
5594 return omit_one_operand (type, integer_one_node, inner);
5596 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
5597 /* MIN (X, 0) > 0 -> false
5598 MIN (X, 0) > 5 -> false */
5599 return omit_one_operand (type, integer_zero_node, inner);
5602 /* MIN (X, 0) > -1 -> X > -1 */
5603 return fold_build2 (GT_EXPR, type, inner, comp_const);
5610 /* T is an integer expression that is being multiplied, divided, or taken a
5611 modulus (CODE says which and what kind of divide or modulus) by a
5612 constant C. See if we can eliminate that operation by folding it with
5613 other operations already in T. WIDE_TYPE, if non-null, is a type that
5614 should be used for the computation if wider than our type.
5616 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
5617 (X * 2) + (Y * 4). We must, however, be assured that either the original
5618 expression would not overflow or that overflow is undefined for the type
5619 in the language in question.
5621 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
5622 the machine has a multiply-accumulate insn or that this is part of an
5623 addressing calculation.
5625 If we return a non-null expression, it is an equivalent form of the
5626 original computation, but need not be in the original type.
5628 We set *STRICT_OVERFLOW_P to true if the return values depends on
5629 signed overflow being undefined. Otherwise we do not change
5630 *STRICT_OVERFLOW_P. */
5633 extract_muldiv (tree t, tree c, enum tree_code code, tree wide_type,
5634 bool *strict_overflow_p)
5636 /* To avoid exponential search depth, refuse to allow recursion past
5637 three levels. Beyond that (1) it's highly unlikely that we'll find
5638 something interesting and (2) we've probably processed it before
5639 when we built the inner expression. */
5648 ret = extract_muldiv_1 (t, c, code, wide_type, strict_overflow_p);
5655 extract_muldiv_1 (tree t, tree c, enum tree_code code, tree wide_type,
5656 bool *strict_overflow_p)
5658 tree type = TREE_TYPE (t);
5659 enum tree_code tcode = TREE_CODE (t);
5660 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
5661 > GET_MODE_SIZE (TYPE_MODE (type)))
5662 ? wide_type : type);
5664 int same_p = tcode == code;
5665 tree op0 = NULL_TREE, op1 = NULL_TREE;
5666 bool sub_strict_overflow_p;
5668 /* Don't deal with constants of zero here; they confuse the code below. */
5669 if (integer_zerop (c))
5672 if (TREE_CODE_CLASS (tcode) == tcc_unary)
5673 op0 = TREE_OPERAND (t, 0);
5675 if (TREE_CODE_CLASS (tcode) == tcc_binary)
5676 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
5678 /* Note that we need not handle conditional operations here since fold
5679 already handles those cases. So just do arithmetic here. */
5683 /* For a constant, we can always simplify if we are a multiply
5684 or (for divide and modulus) if it is a multiple of our constant. */
5685 if (code == MULT_EXPR
5686 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
5687 return const_binop (code, fold_convert (ctype, t),
5688 fold_convert (ctype, c), 0);
5691 case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
5692 /* If op0 is an expression ... */
5693 if ((COMPARISON_CLASS_P (op0)
5694 || UNARY_CLASS_P (op0)
5695 || BINARY_CLASS_P (op0)
5696 || VL_EXP_CLASS_P (op0)
5697 || EXPRESSION_CLASS_P (op0))
5698 /* ... and is unsigned, and its type is smaller than ctype,
5699 then we cannot pass through as widening. */
5700 && ((TYPE_UNSIGNED (TREE_TYPE (op0))
5701 && ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
5702 && TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
5703 && (GET_MODE_SIZE (TYPE_MODE (ctype))
5704 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
5705 /* ... or this is a truncation (t is narrower than op0),
5706 then we cannot pass through this narrowing. */
5707 || (GET_MODE_SIZE (TYPE_MODE (type))
5708 < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0))))
5709 /* ... or signedness changes for division or modulus,
5710 then we cannot pass through this conversion. */
5711 || (code != MULT_EXPR
5712 && (TYPE_UNSIGNED (ctype)
5713 != TYPE_UNSIGNED (TREE_TYPE (op0))))))
5716 /* Pass the constant down and see if we can make a simplification. If
5717 we can, replace this expression with the inner simplification for
5718 possible later conversion to our or some other type. */
5719 if ((t2 = fold_convert (TREE_TYPE (op0), c)) != 0
5720 && TREE_CODE (t2) == INTEGER_CST
5721 && !TREE_OVERFLOW (t2)
5722 && (0 != (t1 = extract_muldiv (op0, t2, code,
5724 ? ctype : NULL_TREE,
5725 strict_overflow_p))))
5730 /* If widening the type changes it from signed to unsigned, then we
5731 must avoid building ABS_EXPR itself as unsigned. */
5732 if (TYPE_UNSIGNED (ctype) && !TYPE_UNSIGNED (type))
5734 tree cstype = (*lang_hooks.types.signed_type) (ctype);
5735 if ((t1 = extract_muldiv (op0, c, code, cstype, strict_overflow_p))
5738 t1 = fold_build1 (tcode, cstype, fold_convert (cstype, t1));
5739 return fold_convert (ctype, t1);
5745 if ((t1 = extract_muldiv (op0, c, code, wide_type, strict_overflow_p))
5747 return fold_build1 (tcode, ctype, fold_convert (ctype, t1));
5750 case MIN_EXPR: case MAX_EXPR:
5751 /* If widening the type changes the signedness, then we can't perform
5752 this optimization as that changes the result. */
5753 if (TYPE_UNSIGNED (ctype) != TYPE_UNSIGNED (type))
5756 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
5757 sub_strict_overflow_p = false;
5758 if ((t1 = extract_muldiv (op0, c, code, wide_type,
5759 &sub_strict_overflow_p)) != 0
5760 && (t2 = extract_muldiv (op1, c, code, wide_type,
5761 &sub_strict_overflow_p)) != 0)
5763 if (tree_int_cst_sgn (c) < 0)
5764 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
5765 if (sub_strict_overflow_p)
5766 *strict_overflow_p = true;
5767 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
5768 fold_convert (ctype, t2));
5772 case LSHIFT_EXPR: case RSHIFT_EXPR:
5773 /* If the second operand is constant, this is a multiplication
5774 or floor division, by a power of two, so we can treat it that
5775 way unless the multiplier or divisor overflows. Signed
5776 left-shift overflow is implementation-defined rather than
5777 undefined in C90, so do not convert signed left shift into
5779 if (TREE_CODE (op1) == INTEGER_CST
5780 && (tcode == RSHIFT_EXPR || TYPE_UNSIGNED (TREE_TYPE (op0)))
5781 /* const_binop may not detect overflow correctly,
5782 so check for it explicitly here. */
5783 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
5784 && TREE_INT_CST_HIGH (op1) == 0
5785 && 0 != (t1 = fold_convert (ctype,
5786 const_binop (LSHIFT_EXPR,
5789 && !TREE_OVERFLOW (t1))
5790 return extract_muldiv (build2 (tcode == LSHIFT_EXPR
5791 ? MULT_EXPR : FLOOR_DIV_EXPR,
5792 ctype, fold_convert (ctype, op0), t1),
5793 c, code, wide_type, strict_overflow_p);
5796 case PLUS_EXPR: case MINUS_EXPR:
5797 /* See if we can eliminate the operation on both sides. If we can, we
5798 can return a new PLUS or MINUS. If we can't, the only remaining
5799 cases where we can do anything are if the second operand is a
5801 sub_strict_overflow_p = false;
5802 t1 = extract_muldiv (op0, c, code, wide_type, &sub_strict_overflow_p);
5803 t2 = extract_muldiv (op1, c, code, wide_type, &sub_strict_overflow_p);
5804 if (t1 != 0 && t2 != 0
5805 && (code == MULT_EXPR
5806 /* If not multiplication, we can only do this if both operands
5807 are divisible by c. */
5808 || (multiple_of_p (ctype, op0, c)
5809 && multiple_of_p (ctype, op1, c))))
5811 if (sub_strict_overflow_p)
5812 *strict_overflow_p = true;
5813 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
5814 fold_convert (ctype, t2));
5817 /* If this was a subtraction, negate OP1 and set it to be an addition.
5818 This simplifies the logic below. */
5819 if (tcode == MINUS_EXPR)
5820 tcode = PLUS_EXPR, op1 = negate_expr (op1);
5822 if (TREE_CODE (op1) != INTEGER_CST)
5825 /* If either OP1 or C are negative, this optimization is not safe for
5826 some of the division and remainder types while for others we need
5827 to change the code. */
5828 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
5830 if (code == CEIL_DIV_EXPR)
5831 code = FLOOR_DIV_EXPR;
5832 else if (code == FLOOR_DIV_EXPR)
5833 code = CEIL_DIV_EXPR;
5834 else if (code != MULT_EXPR
5835 && code != CEIL_MOD_EXPR && code != FLOOR_MOD_EXPR)
5839 /* If it's a multiply or a division/modulus operation of a multiple
5840 of our constant, do the operation and verify it doesn't overflow. */
5841 if (code == MULT_EXPR
5842 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5844 op1 = const_binop (code, fold_convert (ctype, op1),
5845 fold_convert (ctype, c), 0);
5846 /* We allow the constant to overflow with wrapping semantics. */
5848 || (TREE_OVERFLOW (op1) && !TYPE_OVERFLOW_WRAPS (ctype)))
5854 /* If we have an unsigned type is not a sizetype, we cannot widen
5855 the operation since it will change the result if the original
5856 computation overflowed. */
5857 if (TYPE_UNSIGNED (ctype)
5858 && ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
5862 /* If we were able to eliminate our operation from the first side,
5863 apply our operation to the second side and reform the PLUS. */
5864 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
5865 return fold_build2 (tcode, ctype, fold_convert (ctype, t1), op1);
5867 /* The last case is if we are a multiply. In that case, we can
5868 apply the distributive law to commute the multiply and addition
5869 if the multiplication of the constants doesn't overflow. */
5870 if (code == MULT_EXPR)
5871 return fold_build2 (tcode, ctype,
5872 fold_build2 (code, ctype,
5873 fold_convert (ctype, op0),
5874 fold_convert (ctype, c)),
5880 /* We have a special case here if we are doing something like
5881 (C * 8) % 4 since we know that's zero. */
5882 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
5883 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
5884 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
5885 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5886 return omit_one_operand (type, integer_zero_node, op0);
5888 /* ... fall through ... */
5890 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
5891 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
5892 /* If we can extract our operation from the LHS, do so and return a
5893 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
5894 do something only if the second operand is a constant. */
5896 && (t1 = extract_muldiv (op0, c, code, wide_type,
5897 strict_overflow_p)) != 0)
5898 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
5899 fold_convert (ctype, op1));
5900 else if (tcode == MULT_EXPR && code == MULT_EXPR
5901 && (t1 = extract_muldiv (op1, c, code, wide_type,
5902 strict_overflow_p)) != 0)
5903 return fold_build2 (tcode, ctype, fold_convert (ctype, op0),
5904 fold_convert (ctype, t1));
5905 else if (TREE_CODE (op1) != INTEGER_CST)
5908 /* If these are the same operation types, we can associate them
5909 assuming no overflow. */
5911 && 0 != (t1 = const_binop (MULT_EXPR, fold_convert (ctype, op1),
5912 fold_convert (ctype, c), 0))
5913 && !TREE_OVERFLOW (t1))
5914 return fold_build2 (tcode, ctype, fold_convert (ctype, op0), t1);
5916 /* If these operations "cancel" each other, we have the main
5917 optimizations of this pass, which occur when either constant is a
5918 multiple of the other, in which case we replace this with either an
5919 operation or CODE or TCODE.
5921 If we have an unsigned type that is not a sizetype, we cannot do
5922 this since it will change the result if the original computation
5924 if ((TYPE_OVERFLOW_UNDEFINED (ctype)
5925 || (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
5926 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
5927 || (tcode == MULT_EXPR
5928 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
5929 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR)))
5931 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5933 if (TYPE_OVERFLOW_UNDEFINED (ctype))
5934 *strict_overflow_p = true;
5935 return fold_build2 (tcode, ctype, fold_convert (ctype, op0),
5936 fold_convert (ctype,
5937 const_binop (TRUNC_DIV_EXPR,
5940 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
5942 if (TYPE_OVERFLOW_UNDEFINED (ctype))
5943 *strict_overflow_p = true;
5944 return fold_build2 (code, ctype, fold_convert (ctype, op0),
5945 fold_convert (ctype,
5946 const_binop (TRUNC_DIV_EXPR,
5959 /* Return a node which has the indicated constant VALUE (either 0 or
5960 1), and is of the indicated TYPE. */
5963 constant_boolean_node (int value, tree type)
5965 if (type == integer_type_node)
5966 return value ? integer_one_node : integer_zero_node;
5967 else if (type == boolean_type_node)
5968 return value ? boolean_true_node : boolean_false_node;
5970 return build_int_cst (type, value);
5974 /* Return true if expr looks like an ARRAY_REF and set base and
5975 offset to the appropriate trees. If there is no offset,
5976 offset is set to NULL_TREE. Base will be canonicalized to
5977 something you can get the element type from using
5978 TREE_TYPE (TREE_TYPE (base)). Offset will be the offset
5979 in bytes to the base. */
5982 extract_array_ref (tree expr, tree *base, tree *offset)
5984 /* One canonical form is a PLUS_EXPR with the first
5985 argument being an ADDR_EXPR with a possible NOP_EXPR
5987 if (TREE_CODE (expr) == PLUS_EXPR)
5989 tree op0 = TREE_OPERAND (expr, 0);
5990 tree inner_base, dummy1;
5991 /* Strip NOP_EXPRs here because the C frontends and/or
5992 folders present us (int *)&x.a + 4B possibly. */
5994 if (extract_array_ref (op0, &inner_base, &dummy1))
5997 if (dummy1 == NULL_TREE)
5998 *offset = TREE_OPERAND (expr, 1);
6000 *offset = fold_build2 (PLUS_EXPR, TREE_TYPE (expr),
6001 dummy1, TREE_OPERAND (expr, 1));
6005 /* Other canonical form is an ADDR_EXPR of an ARRAY_REF,
6006 which we transform into an ADDR_EXPR with appropriate
6007 offset. For other arguments to the ADDR_EXPR we assume
6008 zero offset and as such do not care about the ADDR_EXPR
6009 type and strip possible nops from it. */
6010 else if (TREE_CODE (expr) == ADDR_EXPR)
6012 tree op0 = TREE_OPERAND (expr, 0);
6013 if (TREE_CODE (op0) == ARRAY_REF)
6015 tree idx = TREE_OPERAND (op0, 1);
6016 *base = TREE_OPERAND (op0, 0);
6017 *offset = fold_build2 (MULT_EXPR, TREE_TYPE (idx), idx,
6018 array_ref_element_size (op0));
6022 /* Handle array-to-pointer decay as &a. */
6023 if (TREE_CODE (TREE_TYPE (op0)) == ARRAY_TYPE)
6024 *base = TREE_OPERAND (expr, 0);
6027 *offset = NULL_TREE;
6031 /* The next canonical form is a VAR_DECL with POINTER_TYPE. */
6032 else if (SSA_VAR_P (expr)
6033 && TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
6036 *offset = NULL_TREE;
6044 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
6045 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
6046 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
6047 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
6048 COND is the first argument to CODE; otherwise (as in the example
6049 given here), it is the second argument. TYPE is the type of the
6050 original expression. Return NULL_TREE if no simplification is
6054 fold_binary_op_with_conditional_arg (enum tree_code code,
6055 tree type, tree op0, tree op1,
6056 tree cond, tree arg, int cond_first_p)
6058 tree cond_type = cond_first_p ? TREE_TYPE (op0) : TREE_TYPE (op1);
6059 tree arg_type = cond_first_p ? TREE_TYPE (op1) : TREE_TYPE (op0);
6060 tree test, true_value, false_value;
6061 tree lhs = NULL_TREE;
6062 tree rhs = NULL_TREE;
6064 /* This transformation is only worthwhile if we don't have to wrap
6065 arg in a SAVE_EXPR, and the operation can be simplified on at least
6066 one of the branches once its pushed inside the COND_EXPR. */
6067 if (!TREE_CONSTANT (arg))
6070 if (TREE_CODE (cond) == COND_EXPR)
6072 test = TREE_OPERAND (cond, 0);
6073 true_value = TREE_OPERAND (cond, 1);
6074 false_value = TREE_OPERAND (cond, 2);
6075 /* If this operand throws an expression, then it does not make
6076 sense to try to perform a logical or arithmetic operation
6078 if (VOID_TYPE_P (TREE_TYPE (true_value)))
6080 if (VOID_TYPE_P (TREE_TYPE (false_value)))
6085 tree testtype = TREE_TYPE (cond);
6087 true_value = constant_boolean_node (true, testtype);
6088 false_value = constant_boolean_node (false, testtype);
6091 arg = fold_convert (arg_type, arg);
6094 true_value = fold_convert (cond_type, true_value);
6096 lhs = fold_build2 (code, type, true_value, arg);
6098 lhs = fold_build2 (code, type, arg, true_value);
6102 false_value = fold_convert (cond_type, false_value);
6104 rhs = fold_build2 (code, type, false_value, arg);
6106 rhs = fold_build2 (code, type, arg, false_value);
6109 test = fold_build3 (COND_EXPR, type, test, lhs, rhs);
6110 return fold_convert (type, test);
6114 /* Subroutine of fold() that checks for the addition of +/- 0.0.
6116 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
6117 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
6118 ADDEND is the same as X.
6120 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
6121 and finite. The problematic cases are when X is zero, and its mode
6122 has signed zeros. In the case of rounding towards -infinity,
6123 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
6124 modes, X + 0 is not the same as X because -0 + 0 is 0. */
6127 fold_real_zero_addition_p (tree type, tree addend, int negate)
6129 if (!real_zerop (addend))
6132 /* Don't allow the fold with -fsignaling-nans. */
6133 if (HONOR_SNANS (TYPE_MODE (type)))
6136 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
6137 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
6140 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
6141 if (TREE_CODE (addend) == REAL_CST
6142 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
6145 /* The mode has signed zeros, and we have to honor their sign.
6146 In this situation, there is only one case we can return true for.
6147 X - 0 is the same as X unless rounding towards -infinity is
6149 return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
6152 /* Subroutine of fold() that checks comparisons of built-in math
6153 functions against real constants.
6155 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
6156 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
6157 is the type of the result and ARG0 and ARG1 are the operands of the
6158 comparison. ARG1 must be a TREE_REAL_CST.
6160 The function returns the constant folded tree if a simplification
6161 can be made, and NULL_TREE otherwise. */
6164 fold_mathfn_compare (enum built_in_function fcode, enum tree_code code,
6165 tree type, tree arg0, tree arg1)
6169 if (BUILTIN_SQRT_P (fcode))
6171 tree arg = CALL_EXPR_ARG (arg0, 0);
6172 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg0));
6174 c = TREE_REAL_CST (arg1);
6175 if (REAL_VALUE_NEGATIVE (c))
6177 /* sqrt(x) < y is always false, if y is negative. */
6178 if (code == EQ_EXPR || code == LT_EXPR || code == LE_EXPR)
6179 return omit_one_operand (type, integer_zero_node, arg);
6181 /* sqrt(x) > y is always true, if y is negative and we
6182 don't care about NaNs, i.e. negative values of x. */
6183 if (code == NE_EXPR || !HONOR_NANS (mode))
6184 return omit_one_operand (type, integer_one_node, arg);
6186 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
6187 return fold_build2 (GE_EXPR, type, arg,
6188 build_real (TREE_TYPE (arg), dconst0));
6190 else if (code == GT_EXPR || code == GE_EXPR)
6194 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
6195 real_convert (&c2, mode, &c2);
6197 if (REAL_VALUE_ISINF (c2))
6199 /* sqrt(x) > y is x == +Inf, when y is very large. */
6200 if (HONOR_INFINITIES (mode))
6201 return fold_build2 (EQ_EXPR, type, arg,
6202 build_real (TREE_TYPE (arg), c2));
6204 /* sqrt(x) > y is always false, when y is very large
6205 and we don't care about infinities. */
6206 return omit_one_operand (type, integer_zero_node, arg);
6209 /* sqrt(x) > c is the same as x > c*c. */
6210 return fold_build2 (code, type, arg,
6211 build_real (TREE_TYPE (arg), c2));
6213 else if (code == LT_EXPR || code == LE_EXPR)
6217 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
6218 real_convert (&c2, mode, &c2);
6220 if (REAL_VALUE_ISINF (c2))
6222 /* sqrt(x) < y is always true, when y is a very large
6223 value and we don't care about NaNs or Infinities. */
6224 if (! HONOR_NANS (mode) && ! HONOR_INFINITIES (mode))
6225 return omit_one_operand (type, integer_one_node, arg);
6227 /* sqrt(x) < y is x != +Inf when y is very large and we
6228 don't care about NaNs. */
6229 if (! HONOR_NANS (mode))
6230 return fold_build2 (NE_EXPR, type, arg,
6231 build_real (TREE_TYPE (arg), c2));
6233 /* sqrt(x) < y is x >= 0 when y is very large and we
6234 don't care about Infinities. */
6235 if (! HONOR_INFINITIES (mode))
6236 return fold_build2 (GE_EXPR, type, arg,
6237 build_real (TREE_TYPE (arg), dconst0));
6239 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
6240 if (lang_hooks.decls.global_bindings_p () != 0
6241 || CONTAINS_PLACEHOLDER_P (arg))
6244 arg = save_expr (arg);
6245 return fold_build2 (TRUTH_ANDIF_EXPR, type,
6246 fold_build2 (GE_EXPR, type, arg,
6247 build_real (TREE_TYPE (arg),
6249 fold_build2 (NE_EXPR, type, arg,
6250 build_real (TREE_TYPE (arg),
6254 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
6255 if (! HONOR_NANS (mode))
6256 return fold_build2 (code, type, arg,
6257 build_real (TREE_TYPE (arg), c2));
6259 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
6260 if (lang_hooks.decls.global_bindings_p () == 0
6261 && ! CONTAINS_PLACEHOLDER_P (arg))
6263 arg = save_expr (arg);
6264 return fold_build2 (TRUTH_ANDIF_EXPR, type,
6265 fold_build2 (GE_EXPR, type, arg,
6266 build_real (TREE_TYPE (arg),
6268 fold_build2 (code, type, arg,
6269 build_real (TREE_TYPE (arg),
6278 /* Subroutine of fold() that optimizes comparisons against Infinities,
6279 either +Inf or -Inf.
6281 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
6282 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
6283 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
6285 The function returns the constant folded tree if a simplification
6286 can be made, and NULL_TREE otherwise. */
6289 fold_inf_compare (enum tree_code code, tree type, tree arg0, tree arg1)
6291 enum machine_mode mode;
6292 REAL_VALUE_TYPE max;
6296 mode = TYPE_MODE (TREE_TYPE (arg0));
6298 /* For negative infinity swap the sense of the comparison. */
6299 neg = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1));
6301 code = swap_tree_comparison (code);
6306 /* x > +Inf is always false, if with ignore sNANs. */
6307 if (HONOR_SNANS (mode))
6309 return omit_one_operand (type, integer_zero_node, arg0);
6312 /* x <= +Inf is always true, if we don't case about NaNs. */
6313 if (! HONOR_NANS (mode))
6314 return omit_one_operand (type, integer_one_node, arg0);
6316 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
6317 if (lang_hooks.decls.global_bindings_p () == 0
6318 && ! CONTAINS_PLACEHOLDER_P (arg0))
6320 arg0 = save_expr (arg0);
6321 return fold_build2 (EQ_EXPR, type, arg0, arg0);
6327 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
6328 real_maxval (&max, neg, mode);
6329 return fold_build2 (neg ? LT_EXPR : GT_EXPR, type,
6330 arg0, build_real (TREE_TYPE (arg0), max));
6333 /* x < +Inf is always equal to x <= DBL_MAX. */
6334 real_maxval (&max, neg, mode);
6335 return fold_build2 (neg ? GE_EXPR : LE_EXPR, type,
6336 arg0, build_real (TREE_TYPE (arg0), max));
6339 /* x != +Inf is always equal to !(x > DBL_MAX). */
6340 real_maxval (&max, neg, mode);
6341 if (! HONOR_NANS (mode))
6342 return fold_build2 (neg ? GE_EXPR : LE_EXPR, type,
6343 arg0, build_real (TREE_TYPE (arg0), max));
6345 temp = fold_build2 (neg ? LT_EXPR : GT_EXPR, type,
6346 arg0, build_real (TREE_TYPE (arg0), max));
6347 return fold_build1 (TRUTH_NOT_EXPR, type, temp);
6356 /* Subroutine of fold() that optimizes comparisons of a division by
6357 a nonzero integer constant against an integer constant, i.e.
6360 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
6361 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
6362 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
6364 The function returns the constant folded tree if a simplification
6365 can be made, and NULL_TREE otherwise. */
6368 fold_div_compare (enum tree_code code, tree type, tree arg0, tree arg1)
6370 tree prod, tmp, hi, lo;
6371 tree arg00 = TREE_OPERAND (arg0, 0);
6372 tree arg01 = TREE_OPERAND (arg0, 1);
6373 unsigned HOST_WIDE_INT lpart;
6374 HOST_WIDE_INT hpart;
6375 bool unsigned_p = TYPE_UNSIGNED (TREE_TYPE (arg0));
6379 /* We have to do this the hard way to detect unsigned overflow.
6380 prod = int_const_binop (MULT_EXPR, arg01, arg1, 0); */
6381 overflow = mul_double_with_sign (TREE_INT_CST_LOW (arg01),
6382 TREE_INT_CST_HIGH (arg01),
6383 TREE_INT_CST_LOW (arg1),
6384 TREE_INT_CST_HIGH (arg1),
6385 &lpart, &hpart, unsigned_p);
6386 prod = force_fit_type_double (TREE_TYPE (arg00), lpart, hpart,
6388 neg_overflow = false;
6392 tmp = int_const_binop (MINUS_EXPR, arg01,
6393 build_int_cst (TREE_TYPE (arg01), 1), 0);
6396 /* Likewise hi = int_const_binop (PLUS_EXPR, prod, tmp, 0). */
6397 overflow = add_double_with_sign (TREE_INT_CST_LOW (prod),
6398 TREE_INT_CST_HIGH (prod),
6399 TREE_INT_CST_LOW (tmp),
6400 TREE_INT_CST_HIGH (tmp),
6401 &lpart, &hpart, unsigned_p);
6402 hi = force_fit_type_double (TREE_TYPE (arg00), lpart, hpart,
6403 -1, overflow | TREE_OVERFLOW (prod));
6405 else if (tree_int_cst_sgn (arg01) >= 0)
6407 tmp = int_const_binop (MINUS_EXPR, arg01,
6408 build_int_cst (TREE_TYPE (arg01), 1), 0);
6409 switch (tree_int_cst_sgn (arg1))
6412 neg_overflow = true;
6413 lo = int_const_binop (MINUS_EXPR, prod, tmp, 0);
6418 lo = fold_negate_const (tmp, TREE_TYPE (arg0));
6423 hi = int_const_binop (PLUS_EXPR, prod, tmp, 0);
6433 /* A negative divisor reverses the relational operators. */
6434 code = swap_tree_comparison (code);
6436 tmp = int_const_binop (PLUS_EXPR, arg01,
6437 build_int_cst (TREE_TYPE (arg01), 1), 0);
6438 switch (tree_int_cst_sgn (arg1))
6441 hi = int_const_binop (MINUS_EXPR, prod, tmp, 0);
6446 hi = fold_negate_const (tmp, TREE_TYPE (arg0));
6451 neg_overflow = true;
6452 lo = int_const_binop (PLUS_EXPR, prod, tmp, 0);
6464 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
6465 return omit_one_operand (type, integer_zero_node, arg00);
6466 if (TREE_OVERFLOW (hi))
6467 return fold_build2 (GE_EXPR, type, arg00, lo);
6468 if (TREE_OVERFLOW (lo))
6469 return fold_build2 (LE_EXPR, type, arg00, hi);
6470 return build_range_check (type, arg00, 1, lo, hi);
6473 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
6474 return omit_one_operand (type, integer_one_node, arg00);
6475 if (TREE_OVERFLOW (hi))
6476 return fold_build2 (LT_EXPR, type, arg00, lo);
6477 if (TREE_OVERFLOW (lo))
6478 return fold_build2 (GT_EXPR, type, arg00, hi);
6479 return build_range_check (type, arg00, 0, lo, hi);
6482 if (TREE_OVERFLOW (lo))
6484 tmp = neg_overflow ? integer_zero_node : integer_one_node;
6485 return omit_one_operand (type, tmp, arg00);
6487 return fold_build2 (LT_EXPR, type, arg00, lo);
6490 if (TREE_OVERFLOW (hi))
6492 tmp = neg_overflow ? integer_zero_node : integer_one_node;
6493 return omit_one_operand (type, tmp, arg00);
6495 return fold_build2 (LE_EXPR, type, arg00, hi);
6498 if (TREE_OVERFLOW (hi))
6500 tmp = neg_overflow ? integer_one_node : integer_zero_node;
6501 return omit_one_operand (type, tmp, arg00);
6503 return fold_build2 (GT_EXPR, type, arg00, hi);
6506 if (TREE_OVERFLOW (lo))
6508 tmp = neg_overflow ? integer_one_node : integer_zero_node;
6509 return omit_one_operand (type, tmp, arg00);
6511 return fold_build2 (GE_EXPR, type, arg00, lo);
6521 /* If CODE with arguments ARG0 and ARG1 represents a single bit
6522 equality/inequality test, then return a simplified form of the test
6523 using a sign testing. Otherwise return NULL. TYPE is the desired
6527 fold_single_bit_test_into_sign_test (enum tree_code code, tree arg0, tree arg1,
6530 /* If this is testing a single bit, we can optimize the test. */
6531 if ((code == NE_EXPR || code == EQ_EXPR)
6532 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
6533 && integer_pow2p (TREE_OPERAND (arg0, 1)))
6535 /* If we have (A & C) != 0 where C is the sign bit of A, convert
6536 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
6537 tree arg00 = sign_bit_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
6539 if (arg00 != NULL_TREE
6540 /* This is only a win if casting to a signed type is cheap,
6541 i.e. when arg00's type is not a partial mode. */
6542 && TYPE_PRECISION (TREE_TYPE (arg00))
6543 == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg00))))
6545 tree stype = lang_hooks.types.signed_type (TREE_TYPE (arg00));
6546 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
6547 result_type, fold_convert (stype, arg00),
6548 build_int_cst (stype, 0));
6555 /* If CODE with arguments ARG0 and ARG1 represents a single bit
6556 equality/inequality test, then return a simplified form of
6557 the test using shifts and logical operations. Otherwise return
6558 NULL. TYPE is the desired result type. */
6561 fold_single_bit_test (enum tree_code code, tree arg0, tree arg1,
6564 /* If this is testing a single bit, we can optimize the test. */
6565 if ((code == NE_EXPR || code == EQ_EXPR)
6566 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
6567 && integer_pow2p (TREE_OPERAND (arg0, 1)))
6569 tree inner = TREE_OPERAND (arg0, 0);
6570 tree type = TREE_TYPE (arg0);
6571 int bitnum = tree_log2 (TREE_OPERAND (arg0, 1));
6572 enum machine_mode operand_mode = TYPE_MODE (type);
6574 tree signed_type, unsigned_type, intermediate_type;
6577 /* First, see if we can fold the single bit test into a sign-bit
6579 tem = fold_single_bit_test_into_sign_test (code, arg0, arg1,
6584 /* Otherwise we have (A & C) != 0 where C is a single bit,
6585 convert that into ((A >> C2) & 1). Where C2 = log2(C).
6586 Similarly for (A & C) == 0. */
6588 /* If INNER is a right shift of a constant and it plus BITNUM does
6589 not overflow, adjust BITNUM and INNER. */
6590 if (TREE_CODE (inner) == RSHIFT_EXPR
6591 && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST
6592 && TREE_INT_CST_HIGH (TREE_OPERAND (inner, 1)) == 0
6593 && bitnum < TYPE_PRECISION (type)
6594 && 0 > compare_tree_int (TREE_OPERAND (inner, 1),
6595 bitnum - TYPE_PRECISION (type)))
6597 bitnum += TREE_INT_CST_LOW (TREE_OPERAND (inner, 1));
6598 inner = TREE_OPERAND (inner, 0);
6601 /* If we are going to be able to omit the AND below, we must do our
6602 operations as unsigned. If we must use the AND, we have a choice.
6603 Normally unsigned is faster, but for some machines signed is. */
6604 #ifdef LOAD_EXTEND_OP
6605 ops_unsigned = (LOAD_EXTEND_OP (operand_mode) == SIGN_EXTEND
6606 && !flag_syntax_only) ? 0 : 1;
6611 signed_type = lang_hooks.types.type_for_mode (operand_mode, 0);
6612 unsigned_type = lang_hooks.types.type_for_mode (operand_mode, 1);
6613 intermediate_type = ops_unsigned ? unsigned_type : signed_type;
6614 inner = fold_convert (intermediate_type, inner);
6617 inner = build2 (RSHIFT_EXPR, intermediate_type,
6618 inner, size_int (bitnum));
6620 one = build_int_cst (intermediate_type, 1);
6622 if (code == EQ_EXPR)
6623 inner = fold_build2 (BIT_XOR_EXPR, intermediate_type, inner, one);
6625 /* Put the AND last so it can combine with more things. */
6626 inner = build2 (BIT_AND_EXPR, intermediate_type, inner, one);
6628 /* Make sure to return the proper type. */
6629 inner = fold_convert (result_type, inner);
6636 /* Check whether we are allowed to reorder operands arg0 and arg1,
6637 such that the evaluation of arg1 occurs before arg0. */
6640 reorder_operands_p (tree arg0, tree arg1)
6642 if (! flag_evaluation_order)
6644 if (TREE_CONSTANT (arg0) || TREE_CONSTANT (arg1))
6646 return ! TREE_SIDE_EFFECTS (arg0)
6647 && ! TREE_SIDE_EFFECTS (arg1);
6650 /* Test whether it is preferable two swap two operands, ARG0 and
6651 ARG1, for example because ARG0 is an integer constant and ARG1
6652 isn't. If REORDER is true, only recommend swapping if we can
6653 evaluate the operands in reverse order. */
6656 tree_swap_operands_p (tree arg0, tree arg1, bool reorder)
6658 STRIP_SIGN_NOPS (arg0);
6659 STRIP_SIGN_NOPS (arg1);
6661 if (TREE_CODE (arg1) == INTEGER_CST)
6663 if (TREE_CODE (arg0) == INTEGER_CST)
6666 if (TREE_CODE (arg1) == REAL_CST)
6668 if (TREE_CODE (arg0) == REAL_CST)
6671 if (TREE_CODE (arg1) == COMPLEX_CST)
6673 if (TREE_CODE (arg0) == COMPLEX_CST)
6676 if (TREE_CONSTANT (arg1))
6678 if (TREE_CONSTANT (arg0))
6684 if (reorder && flag_evaluation_order
6685 && (TREE_SIDE_EFFECTS (arg0) || TREE_SIDE_EFFECTS (arg1)))
6688 /* It is preferable to swap two SSA_NAME to ensure a canonical form
6689 for commutative and comparison operators. Ensuring a canonical
6690 form allows the optimizers to find additional redundancies without
6691 having to explicitly check for both orderings. */
6692 if (TREE_CODE (arg0) == SSA_NAME
6693 && TREE_CODE (arg1) == SSA_NAME
6694 && SSA_NAME_VERSION (arg0) > SSA_NAME_VERSION (arg1))
6697 /* Put SSA_NAMEs last. */
6698 if (TREE_CODE (arg1) == SSA_NAME)
6700 if (TREE_CODE (arg0) == SSA_NAME)
6703 /* Put variables last. */
6712 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where
6713 ARG0 is extended to a wider type. */
6716 fold_widened_comparison (enum tree_code code, tree type, tree arg0, tree arg1)
6718 tree arg0_unw = get_unwidened (arg0, NULL_TREE);
6720 tree shorter_type, outer_type;
6724 if (arg0_unw == arg0)
6726 shorter_type = TREE_TYPE (arg0_unw);
6728 #ifdef HAVE_canonicalize_funcptr_for_compare
6729 /* Disable this optimization if we're casting a function pointer
6730 type on targets that require function pointer canonicalization. */
6731 if (HAVE_canonicalize_funcptr_for_compare
6732 && TREE_CODE (shorter_type) == POINTER_TYPE
6733 && TREE_CODE (TREE_TYPE (shorter_type)) == FUNCTION_TYPE)
6737 if (TYPE_PRECISION (TREE_TYPE (arg0)) <= TYPE_PRECISION (shorter_type))
6740 arg1_unw = get_unwidened (arg1, shorter_type);
6742 /* If possible, express the comparison in the shorter mode. */
6743 if ((code == EQ_EXPR || code == NE_EXPR
6744 || TYPE_UNSIGNED (TREE_TYPE (arg0)) == TYPE_UNSIGNED (shorter_type))
6745 && (TREE_TYPE (arg1_unw) == shorter_type
6746 || (TREE_CODE (arg1_unw) == INTEGER_CST
6747 && (TREE_CODE (shorter_type) == INTEGER_TYPE
6748 || TREE_CODE (shorter_type) == BOOLEAN_TYPE)
6749 && int_fits_type_p (arg1_unw, shorter_type))))
6750 return fold_build2 (code, type, arg0_unw,
6751 fold_convert (shorter_type, arg1_unw));
6753 if (TREE_CODE (arg1_unw) != INTEGER_CST
6754 || TREE_CODE (shorter_type) != INTEGER_TYPE
6755 || !int_fits_type_p (arg1_unw, shorter_type))
6758 /* If we are comparing with the integer that does not fit into the range
6759 of the shorter type, the result is known. */
6760 outer_type = TREE_TYPE (arg1_unw);
6761 min = lower_bound_in_type (outer_type, shorter_type);
6762 max = upper_bound_in_type (outer_type, shorter_type);
6764 above = integer_nonzerop (fold_relational_const (LT_EXPR, type,
6766 below = integer_nonzerop (fold_relational_const (LT_EXPR, type,
6773 return omit_one_operand (type, integer_zero_node, arg0);
6778 return omit_one_operand (type, integer_one_node, arg0);
6784 return omit_one_operand (type, integer_one_node, arg0);
6786 return omit_one_operand (type, integer_zero_node, arg0);
6791 return omit_one_operand (type, integer_zero_node, arg0);
6793 return omit_one_operand (type, integer_one_node, arg0);
6802 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where for
6803 ARG0 just the signedness is changed. */
6806 fold_sign_changed_comparison (enum tree_code code, tree type,
6807 tree arg0, tree arg1)
6810 tree inner_type, outer_type;
6812 if (TREE_CODE (arg0) != NOP_EXPR
6813 && TREE_CODE (arg0) != CONVERT_EXPR)
6816 outer_type = TREE_TYPE (arg0);
6817 arg0_inner = TREE_OPERAND (arg0, 0);
6818 inner_type = TREE_TYPE (arg0_inner);
6820 #ifdef HAVE_canonicalize_funcptr_for_compare
6821 /* Disable this optimization if we're casting a function pointer
6822 type on targets that require function pointer canonicalization. */
6823 if (HAVE_canonicalize_funcptr_for_compare
6824 && TREE_CODE (inner_type) == POINTER_TYPE
6825 && TREE_CODE (TREE_TYPE (inner_type)) == FUNCTION_TYPE)
6829 if (TYPE_PRECISION (inner_type) != TYPE_PRECISION (outer_type))
6832 if (TREE_CODE (arg1) != INTEGER_CST
6833 && !((TREE_CODE (arg1) == NOP_EXPR
6834 || TREE_CODE (arg1) == CONVERT_EXPR)
6835 && TREE_TYPE (TREE_OPERAND (arg1, 0)) == inner_type))
6838 if (TYPE_UNSIGNED (inner_type) != TYPE_UNSIGNED (outer_type)
6843 if (TREE_CODE (arg1) == INTEGER_CST)
6844 arg1 = force_fit_type_double (inner_type, TREE_INT_CST_LOW (arg1),
6845 TREE_INT_CST_HIGH (arg1), 0,
6846 TREE_OVERFLOW (arg1));
6848 arg1 = fold_convert (inner_type, arg1);
6850 return fold_build2 (code, type, arg0_inner, arg1);
6853 /* Tries to replace &a[idx] CODE s * delta with &a[idx CODE delta], if s is
6854 step of the array. Reconstructs s and delta in the case of s * delta
6855 being an integer constant (and thus already folded).
6856 ADDR is the address. MULT is the multiplicative expression.
6857 If the function succeeds, the new address expression is returned. Otherwise
6858 NULL_TREE is returned. */
6861 try_move_mult_to_index (enum tree_code code, tree addr, tree op1)
6863 tree s, delta, step;
6864 tree ref = TREE_OPERAND (addr, 0), pref;
6869 /* Canonicalize op1 into a possibly non-constant delta
6870 and an INTEGER_CST s. */
6871 if (TREE_CODE (op1) == MULT_EXPR)
6873 tree arg0 = TREE_OPERAND (op1, 0), arg1 = TREE_OPERAND (op1, 1);
6878 if (TREE_CODE (arg0) == INTEGER_CST)
6883 else if (TREE_CODE (arg1) == INTEGER_CST)
6891 else if (TREE_CODE (op1) == INTEGER_CST)
6898 /* Simulate we are delta * 1. */
6900 s = integer_one_node;
6903 for (;; ref = TREE_OPERAND (ref, 0))
6905 if (TREE_CODE (ref) == ARRAY_REF)
6907 /* Remember if this was a multi-dimensional array. */
6908 if (TREE_CODE (TREE_OPERAND (ref, 0)) == ARRAY_REF)
6911 itype = TYPE_DOMAIN (TREE_TYPE (TREE_OPERAND (ref, 0)));
6915 step = array_ref_element_size (ref);
6916 if (TREE_CODE (step) != INTEGER_CST)
6921 if (! tree_int_cst_equal (step, s))
6926 /* Try if delta is a multiple of step. */
6927 tree tmp = div_if_zero_remainder (EXACT_DIV_EXPR, delta, step);
6933 /* Only fold here if we can verify we do not overflow one
6934 dimension of a multi-dimensional array. */
6939 if (TREE_CODE (TREE_OPERAND (ref, 1)) != INTEGER_CST
6940 || !INTEGRAL_TYPE_P (itype)
6941 || !TYPE_MAX_VALUE (itype)
6942 || TREE_CODE (TYPE_MAX_VALUE (itype)) != INTEGER_CST)
6945 tmp = fold_binary (code, itype,
6946 fold_convert (itype,
6947 TREE_OPERAND (ref, 1)),
6948 fold_convert (itype, delta));
6950 || TREE_CODE (tmp) != INTEGER_CST
6951 || tree_int_cst_lt (TYPE_MAX_VALUE (itype), tmp))
6960 if (!handled_component_p (ref))
6964 /* We found the suitable array reference. So copy everything up to it,
6965 and replace the index. */
6967 pref = TREE_OPERAND (addr, 0);
6968 ret = copy_node (pref);
6973 pref = TREE_OPERAND (pref, 0);
6974 TREE_OPERAND (pos, 0) = copy_node (pref);
6975 pos = TREE_OPERAND (pos, 0);
6978 TREE_OPERAND (pos, 1) = fold_build2 (code, itype,
6979 fold_convert (itype,
6980 TREE_OPERAND (pos, 1)),
6981 fold_convert (itype, delta));
6983 return fold_build1 (ADDR_EXPR, TREE_TYPE (addr), ret);
6987 /* Fold A < X && A + 1 > Y to A < X && A >= Y. Normally A + 1 > Y
6988 means A >= Y && A != MAX, but in this case we know that
6989 A < X <= MAX. INEQ is A + 1 > Y, BOUND is A < X. */
6992 fold_to_nonsharp_ineq_using_bound (tree ineq, tree bound)
6994 tree a, typea, type = TREE_TYPE (ineq), a1, diff, y;
6996 if (TREE_CODE (bound) == LT_EXPR)
6997 a = TREE_OPERAND (bound, 0);
6998 else if (TREE_CODE (bound) == GT_EXPR)
6999 a = TREE_OPERAND (bound, 1);
7003 typea = TREE_TYPE (a);
7004 if (!INTEGRAL_TYPE_P (typea)
7005 && !POINTER_TYPE_P (typea))
7008 if (TREE_CODE (ineq) == LT_EXPR)
7010 a1 = TREE_OPERAND (ineq, 1);
7011 y = TREE_OPERAND (ineq, 0);
7013 else if (TREE_CODE (ineq) == GT_EXPR)
7015 a1 = TREE_OPERAND (ineq, 0);
7016 y = TREE_OPERAND (ineq, 1);
7021 if (TREE_TYPE (a1) != typea)
7024 diff = fold_build2 (MINUS_EXPR, typea, a1, a);
7025 if (!integer_onep (diff))
7028 return fold_build2 (GE_EXPR, type, a, y);
7031 /* Fold a sum or difference of at least one multiplication.
7032 Returns the folded tree or NULL if no simplification could be made. */
7035 fold_plusminus_mult_expr (enum tree_code code, tree type, tree arg0, tree arg1)
7037 tree arg00, arg01, arg10, arg11;
7038 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
7040 /* (A * C) +- (B * C) -> (A+-B) * C.
7041 (A * C) +- A -> A * (C+-1).
7042 We are most concerned about the case where C is a constant,
7043 but other combinations show up during loop reduction. Since
7044 it is not difficult, try all four possibilities. */
7046 if (TREE_CODE (arg0) == MULT_EXPR)
7048 arg00 = TREE_OPERAND (arg0, 0);
7049 arg01 = TREE_OPERAND (arg0, 1);
7054 arg01 = build_one_cst (type);
7056 if (TREE_CODE (arg1) == MULT_EXPR)
7058 arg10 = TREE_OPERAND (arg1, 0);
7059 arg11 = TREE_OPERAND (arg1, 1);
7064 arg11 = build_one_cst (type);
7068 if (operand_equal_p (arg01, arg11, 0))
7069 same = arg01, alt0 = arg00, alt1 = arg10;
7070 else if (operand_equal_p (arg00, arg10, 0))
7071 same = arg00, alt0 = arg01, alt1 = arg11;
7072 else if (operand_equal_p (arg00, arg11, 0))
7073 same = arg00, alt0 = arg01, alt1 = arg10;
7074 else if (operand_equal_p (arg01, arg10, 0))
7075 same = arg01, alt0 = arg00, alt1 = arg11;
7077 /* No identical multiplicands; see if we can find a common
7078 power-of-two factor in non-power-of-two multiplies. This
7079 can help in multi-dimensional array access. */
7080 else if (host_integerp (arg01, 0)
7081 && host_integerp (arg11, 0))
7083 HOST_WIDE_INT int01, int11, tmp;
7086 int01 = TREE_INT_CST_LOW (arg01);
7087 int11 = TREE_INT_CST_LOW (arg11);
7089 /* Move min of absolute values to int11. */
7090 if ((int01 >= 0 ? int01 : -int01)
7091 < (int11 >= 0 ? int11 : -int11))
7093 tmp = int01, int01 = int11, int11 = tmp;
7094 alt0 = arg00, arg00 = arg10, arg10 = alt0;
7101 if (exact_log2 (abs (int11)) > 0 && int01 % int11 == 0)
7103 alt0 = fold_build2 (MULT_EXPR, TREE_TYPE (arg00), arg00,
7104 build_int_cst (TREE_TYPE (arg00),
7109 maybe_same = alt0, alt0 = alt1, alt1 = maybe_same;
7114 return fold_build2 (MULT_EXPR, type,
7115 fold_build2 (code, type,
7116 fold_convert (type, alt0),
7117 fold_convert (type, alt1)),
7118 fold_convert (type, same));
7123 /* Subroutine of native_encode_expr. Encode the INTEGER_CST
7124 specified by EXPR into the buffer PTR of length LEN bytes.
7125 Return the number of bytes placed in the buffer, or zero
7129 native_encode_int (tree expr, unsigned char *ptr, int len)
7131 tree type = TREE_TYPE (expr);
7132 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7133 int byte, offset, word, words;
7134 unsigned char value;
7136 if (total_bytes > len)
7138 words = total_bytes / UNITS_PER_WORD;
7140 for (byte = 0; byte < total_bytes; byte++)
7142 int bitpos = byte * BITS_PER_UNIT;
7143 if (bitpos < HOST_BITS_PER_WIDE_INT)
7144 value = (unsigned char) (TREE_INT_CST_LOW (expr) >> bitpos);
7146 value = (unsigned char) (TREE_INT_CST_HIGH (expr)
7147 >> (bitpos - HOST_BITS_PER_WIDE_INT));
7149 if (total_bytes > UNITS_PER_WORD)
7151 word = byte / UNITS_PER_WORD;
7152 if (WORDS_BIG_ENDIAN)
7153 word = (words - 1) - word;
7154 offset = word * UNITS_PER_WORD;
7155 if (BYTES_BIG_ENDIAN)
7156 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7158 offset += byte % UNITS_PER_WORD;
7161 offset = BYTES_BIG_ENDIAN ? (total_bytes - 1) - byte : byte;
7162 ptr[offset] = value;
7168 /* Subroutine of native_encode_expr. Encode the REAL_CST
7169 specified by EXPR into the buffer PTR of length LEN bytes.
7170 Return the number of bytes placed in the buffer, or zero
7174 native_encode_real (tree expr, unsigned char *ptr, int len)
7176 tree type = TREE_TYPE (expr);
7177 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7178 int byte, offset, word, words, bitpos;
7179 unsigned char value;
7181 /* There are always 32 bits in each long, no matter the size of
7182 the hosts long. We handle floating point representations with
7186 if (total_bytes > len)
7188 words = 32 / UNITS_PER_WORD;
7190 real_to_target (tmp, TREE_REAL_CST_PTR (expr), TYPE_MODE (type));
7192 for (bitpos = 0; bitpos < total_bytes * BITS_PER_UNIT;
7193 bitpos += BITS_PER_UNIT)
7195 byte = (bitpos / BITS_PER_UNIT) & 3;
7196 value = (unsigned char) (tmp[bitpos / 32] >> (bitpos & 31));
7198 if (UNITS_PER_WORD < 4)
7200 word = byte / UNITS_PER_WORD;
7201 if (WORDS_BIG_ENDIAN)
7202 word = (words - 1) - word;
7203 offset = word * UNITS_PER_WORD;
7204 if (BYTES_BIG_ENDIAN)
7205 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7207 offset += byte % UNITS_PER_WORD;
7210 offset = BYTES_BIG_ENDIAN ? 3 - byte : byte;
7211 ptr[offset + ((bitpos / BITS_PER_UNIT) & ~3)] = value;
7216 /* Subroutine of native_encode_expr. Encode the COMPLEX_CST
7217 specified by EXPR into the buffer PTR of length LEN bytes.
7218 Return the number of bytes placed in the buffer, or zero
7222 native_encode_complex (tree expr, unsigned char *ptr, int len)
7227 part = TREE_REALPART (expr);
7228 rsize = native_encode_expr (part, ptr, len);
7231 part = TREE_IMAGPART (expr);
7232 isize = native_encode_expr (part, ptr+rsize, len-rsize);
7235 return rsize + isize;
7239 /* Subroutine of native_encode_expr. Encode the VECTOR_CST
7240 specified by EXPR into the buffer PTR of length LEN bytes.
7241 Return the number of bytes placed in the buffer, or zero
7245 native_encode_vector (tree expr, unsigned char *ptr, int len)
7247 int i, size, offset, count;
7248 tree itype, elem, elements;
7251 elements = TREE_VECTOR_CST_ELTS (expr);
7252 count = TYPE_VECTOR_SUBPARTS (TREE_TYPE (expr));
7253 itype = TREE_TYPE (TREE_TYPE (expr));
7254 size = GET_MODE_SIZE (TYPE_MODE (itype));
7255 for (i = 0; i < count; i++)
7259 elem = TREE_VALUE (elements);
7260 elements = TREE_CHAIN (elements);
7267 if (native_encode_expr (elem, ptr+offset, len-offset) != size)
7272 if (offset + size > len)
7274 memset (ptr+offset, 0, size);
7282 /* Subroutine of fold_view_convert_expr. Encode the INTEGER_CST,
7283 REAL_CST, COMPLEX_CST or VECTOR_CST specified by EXPR into the
7284 buffer PTR of length LEN bytes. Return the number of bytes
7285 placed in the buffer, or zero upon failure. */
7288 native_encode_expr (tree expr, unsigned char *ptr, int len)
7290 switch (TREE_CODE (expr))
7293 return native_encode_int (expr, ptr, len);
7296 return native_encode_real (expr, ptr, len);
7299 return native_encode_complex (expr, ptr, len);
7302 return native_encode_vector (expr, ptr, len);
7310 /* Subroutine of native_interpret_expr. Interpret the contents of
7311 the buffer PTR of length LEN as an INTEGER_CST of type TYPE.
7312 If the buffer cannot be interpreted, return NULL_TREE. */
7315 native_interpret_int (tree type, unsigned char *ptr, int len)
7317 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7318 int byte, offset, word, words;
7319 unsigned char value;
7320 unsigned int HOST_WIDE_INT lo = 0;
7321 HOST_WIDE_INT hi = 0;
7323 if (total_bytes > len)
7325 if (total_bytes * BITS_PER_UNIT > 2 * HOST_BITS_PER_WIDE_INT)
7327 words = total_bytes / UNITS_PER_WORD;
7329 for (byte = 0; byte < total_bytes; byte++)
7331 int bitpos = byte * BITS_PER_UNIT;
7332 if (total_bytes > UNITS_PER_WORD)
7334 word = byte / UNITS_PER_WORD;
7335 if (WORDS_BIG_ENDIAN)
7336 word = (words - 1) - word;
7337 offset = word * UNITS_PER_WORD;
7338 if (BYTES_BIG_ENDIAN)
7339 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7341 offset += byte % UNITS_PER_WORD;
7344 offset = BYTES_BIG_ENDIAN ? (total_bytes - 1) - byte : byte;
7345 value = ptr[offset];
7347 if (bitpos < HOST_BITS_PER_WIDE_INT)
7348 lo |= (unsigned HOST_WIDE_INT) value << bitpos;
7350 hi |= (unsigned HOST_WIDE_INT) value
7351 << (bitpos - HOST_BITS_PER_WIDE_INT);
7354 return build_int_cst_wide_type (type, lo, hi);
7358 /* Subroutine of native_interpret_expr. Interpret the contents of
7359 the buffer PTR of length LEN as a REAL_CST of type TYPE.
7360 If the buffer cannot be interpreted, return NULL_TREE. */
7363 native_interpret_real (tree type, unsigned char *ptr, int len)
7365 enum machine_mode mode = TYPE_MODE (type);
7366 int total_bytes = GET_MODE_SIZE (mode);
7367 int byte, offset, word, words, bitpos;
7368 unsigned char value;
7369 /* There are always 32 bits in each long, no matter the size of
7370 the hosts long. We handle floating point representations with
7375 total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7376 if (total_bytes > len || total_bytes > 24)
7378 words = 32 / UNITS_PER_WORD;
7380 memset (tmp, 0, sizeof (tmp));
7381 for (bitpos = 0; bitpos < total_bytes * BITS_PER_UNIT;
7382 bitpos += BITS_PER_UNIT)
7384 byte = (bitpos / BITS_PER_UNIT) & 3;
7385 if (UNITS_PER_WORD < 4)
7387 word = byte / UNITS_PER_WORD;
7388 if (WORDS_BIG_ENDIAN)
7389 word = (words - 1) - word;
7390 offset = word * UNITS_PER_WORD;
7391 if (BYTES_BIG_ENDIAN)
7392 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7394 offset += byte % UNITS_PER_WORD;
7397 offset = BYTES_BIG_ENDIAN ? 3 - byte : byte;
7398 value = ptr[offset + ((bitpos / BITS_PER_UNIT) & ~3)];
7400 tmp[bitpos / 32] |= (unsigned long)value << (bitpos & 31);
7403 real_from_target (&r, tmp, mode);
7404 return build_real (type, r);
7408 /* Subroutine of native_interpret_expr. Interpret the contents of
7409 the buffer PTR of length LEN as a COMPLEX_CST of type TYPE.
7410 If the buffer cannot be interpreted, return NULL_TREE. */
7413 native_interpret_complex (tree type, unsigned char *ptr, int len)
7415 tree etype, rpart, ipart;
7418 etype = TREE_TYPE (type);
7419 size = GET_MODE_SIZE (TYPE_MODE (etype));
7422 rpart = native_interpret_expr (etype, ptr, size);
7425 ipart = native_interpret_expr (etype, ptr+size, size);
7428 return build_complex (type, rpart, ipart);
7432 /* Subroutine of native_interpret_expr. Interpret the contents of
7433 the buffer PTR of length LEN as a VECTOR_CST of type TYPE.
7434 If the buffer cannot be interpreted, return NULL_TREE. */
7437 native_interpret_vector (tree type, unsigned char *ptr, int len)
7439 tree etype, elem, elements;
7442 etype = TREE_TYPE (type);
7443 size = GET_MODE_SIZE (TYPE_MODE (etype));
7444 count = TYPE_VECTOR_SUBPARTS (type);
7445 if (size * count > len)
7448 elements = NULL_TREE;
7449 for (i = count - 1; i >= 0; i--)
7451 elem = native_interpret_expr (etype, ptr+(i*size), size);
7454 elements = tree_cons (NULL_TREE, elem, elements);
7456 return build_vector (type, elements);
7460 /* Subroutine of fold_view_convert_expr. Interpret the contents of
7461 the buffer PTR of length LEN as a constant of type TYPE. For
7462 INTEGRAL_TYPE_P we return an INTEGER_CST, for SCALAR_FLOAT_TYPE_P
7463 we return a REAL_CST, etc... If the buffer cannot be interpreted,
7464 return NULL_TREE. */
7467 native_interpret_expr (tree type, unsigned char *ptr, int len)
7469 switch (TREE_CODE (type))
7474 return native_interpret_int (type, ptr, len);
7477 return native_interpret_real (type, ptr, len);
7480 return native_interpret_complex (type, ptr, len);
7483 return native_interpret_vector (type, ptr, len);
7491 /* Fold a VIEW_CONVERT_EXPR of a constant expression EXPR to type
7492 TYPE at compile-time. If we're unable to perform the conversion
7493 return NULL_TREE. */
7496 fold_view_convert_expr (tree type, tree expr)
7498 /* We support up to 512-bit values (for V8DFmode). */
7499 unsigned char buffer[64];
7502 /* Check that the host and target are sane. */
7503 if (CHAR_BIT != 8 || BITS_PER_UNIT != 8)
7506 len = native_encode_expr (expr, buffer, sizeof (buffer));
7510 return native_interpret_expr (type, buffer, len);
7514 /* Fold a unary expression of code CODE and type TYPE with operand
7515 OP0. Return the folded expression if folding is successful.
7516 Otherwise, return NULL_TREE. */
7519 fold_unary (enum tree_code code, tree type, tree op0)
7523 enum tree_code_class kind = TREE_CODE_CLASS (code);
7525 gcc_assert (IS_EXPR_CODE_CLASS (kind)
7526 && TREE_CODE_LENGTH (code) == 1);
7531 if (code == NOP_EXPR || code == CONVERT_EXPR
7532 || code == FLOAT_EXPR || code == ABS_EXPR)
7534 /* Don't use STRIP_NOPS, because signedness of argument type
7536 STRIP_SIGN_NOPS (arg0);
7540 /* Strip any conversions that don't change the mode. This
7541 is safe for every expression, except for a comparison
7542 expression because its signedness is derived from its
7545 Note that this is done as an internal manipulation within
7546 the constant folder, in order to find the simplest
7547 representation of the arguments so that their form can be
7548 studied. In any cases, the appropriate type conversions
7549 should be put back in the tree that will get out of the
7555 if (TREE_CODE_CLASS (code) == tcc_unary)
7557 if (TREE_CODE (arg0) == COMPOUND_EXPR)
7558 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
7559 fold_build1 (code, type, TREE_OPERAND (arg0, 1)));
7560 else if (TREE_CODE (arg0) == COND_EXPR)
7562 tree arg01 = TREE_OPERAND (arg0, 1);
7563 tree arg02 = TREE_OPERAND (arg0, 2);
7564 if (! VOID_TYPE_P (TREE_TYPE (arg01)))
7565 arg01 = fold_build1 (code, type, arg01);
7566 if (! VOID_TYPE_P (TREE_TYPE (arg02)))
7567 arg02 = fold_build1 (code, type, arg02);
7568 tem = fold_build3 (COND_EXPR, type, TREE_OPERAND (arg0, 0),
7571 /* If this was a conversion, and all we did was to move into
7572 inside the COND_EXPR, bring it back out. But leave it if
7573 it is a conversion from integer to integer and the
7574 result precision is no wider than a word since such a
7575 conversion is cheap and may be optimized away by combine,
7576 while it couldn't if it were outside the COND_EXPR. Then return
7577 so we don't get into an infinite recursion loop taking the
7578 conversion out and then back in. */
7580 if ((code == NOP_EXPR || code == CONVERT_EXPR
7581 || code == NON_LVALUE_EXPR)
7582 && TREE_CODE (tem) == COND_EXPR
7583 && TREE_CODE (TREE_OPERAND (tem, 1)) == code
7584 && TREE_CODE (TREE_OPERAND (tem, 2)) == code
7585 && ! VOID_TYPE_P (TREE_OPERAND (tem, 1))
7586 && ! VOID_TYPE_P (TREE_OPERAND (tem, 2))
7587 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))
7588 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 2), 0)))
7589 && (! (INTEGRAL_TYPE_P (TREE_TYPE (tem))
7591 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))))
7592 && TYPE_PRECISION (TREE_TYPE (tem)) <= BITS_PER_WORD)
7593 || flag_syntax_only))
7594 tem = build1 (code, type,
7596 TREE_TYPE (TREE_OPERAND
7597 (TREE_OPERAND (tem, 1), 0)),
7598 TREE_OPERAND (tem, 0),
7599 TREE_OPERAND (TREE_OPERAND (tem, 1), 0),
7600 TREE_OPERAND (TREE_OPERAND (tem, 2), 0)));
7603 else if (COMPARISON_CLASS_P (arg0))
7605 if (TREE_CODE (type) == BOOLEAN_TYPE)
7607 arg0 = copy_node (arg0);
7608 TREE_TYPE (arg0) = type;
7611 else if (TREE_CODE (type) != INTEGER_TYPE)
7612 return fold_build3 (COND_EXPR, type, arg0,
7613 fold_build1 (code, type,
7615 fold_build1 (code, type,
7616 integer_zero_node));
7625 case FIX_TRUNC_EXPR:
7626 if (TREE_TYPE (op0) == type)
7629 /* If we have (type) (a CMP b) and type is an integral type, return
7630 new expression involving the new type. */
7631 if (COMPARISON_CLASS_P (op0) && INTEGRAL_TYPE_P (type))
7632 return fold_build2 (TREE_CODE (op0), type, TREE_OPERAND (op0, 0),
7633 TREE_OPERAND (op0, 1));
7635 /* Handle cases of two conversions in a row. */
7636 if (TREE_CODE (op0) == NOP_EXPR
7637 || TREE_CODE (op0) == CONVERT_EXPR)
7639 tree inside_type = TREE_TYPE (TREE_OPERAND (op0, 0));
7640 tree inter_type = TREE_TYPE (op0);
7641 int inside_int = INTEGRAL_TYPE_P (inside_type);
7642 int inside_ptr = POINTER_TYPE_P (inside_type);
7643 int inside_float = FLOAT_TYPE_P (inside_type);
7644 int inside_vec = TREE_CODE (inside_type) == VECTOR_TYPE;
7645 unsigned int inside_prec = TYPE_PRECISION (inside_type);
7646 int inside_unsignedp = TYPE_UNSIGNED (inside_type);
7647 int inter_int = INTEGRAL_TYPE_P (inter_type);
7648 int inter_ptr = POINTER_TYPE_P (inter_type);
7649 int inter_float = FLOAT_TYPE_P (inter_type);
7650 int inter_vec = TREE_CODE (inter_type) == VECTOR_TYPE;
7651 unsigned int inter_prec = TYPE_PRECISION (inter_type);
7652 int inter_unsignedp = TYPE_UNSIGNED (inter_type);
7653 int final_int = INTEGRAL_TYPE_P (type);
7654 int final_ptr = POINTER_TYPE_P (type);
7655 int final_float = FLOAT_TYPE_P (type);
7656 int final_vec = TREE_CODE (type) == VECTOR_TYPE;
7657 unsigned int final_prec = TYPE_PRECISION (type);
7658 int final_unsignedp = TYPE_UNSIGNED (type);
7660 /* In addition to the cases of two conversions in a row
7661 handled below, if we are converting something to its own
7662 type via an object of identical or wider precision, neither
7663 conversion is needed. */
7664 if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (type)
7665 && (((inter_int || inter_ptr) && final_int)
7666 || (inter_float && final_float))
7667 && inter_prec >= final_prec)
7668 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
7670 /* Likewise, if the intermediate and final types are either both
7671 float or both integer, we don't need the middle conversion if
7672 it is wider than the final type and doesn't change the signedness
7673 (for integers). Avoid this if the final type is a pointer
7674 since then we sometimes need the inner conversion. Likewise if
7675 the outer has a precision not equal to the size of its mode. */
7676 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
7677 || (inter_float && inside_float)
7678 || (inter_vec && inside_vec))
7679 && inter_prec >= inside_prec
7680 && (inter_float || inter_vec
7681 || inter_unsignedp == inside_unsignedp)
7682 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
7683 && TYPE_MODE (type) == TYPE_MODE (inter_type))
7685 && (! final_vec || inter_prec == inside_prec))
7686 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
7688 /* If we have a sign-extension of a zero-extended value, we can
7689 replace that by a single zero-extension. */
7690 if (inside_int && inter_int && final_int
7691 && inside_prec < inter_prec && inter_prec < final_prec
7692 && inside_unsignedp && !inter_unsignedp)
7693 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
7695 /* Two conversions in a row are not needed unless:
7696 - some conversion is floating-point (overstrict for now), or
7697 - some conversion is a vector (overstrict for now), or
7698 - the intermediate type is narrower than both initial and
7700 - the intermediate type and innermost type differ in signedness,
7701 and the outermost type is wider than the intermediate, or
7702 - the initial type is a pointer type and the precisions of the
7703 intermediate and final types differ, or
7704 - the final type is a pointer type and the precisions of the
7705 initial and intermediate types differ.
7706 - the final type is a pointer type and the initial type not
7707 - the initial type is a pointer to an array and the final type
7709 if (! inside_float && ! inter_float && ! final_float
7710 && ! inside_vec && ! inter_vec && ! final_vec
7711 && (inter_prec >= inside_prec || inter_prec >= final_prec)
7712 && ! (inside_int && inter_int
7713 && inter_unsignedp != inside_unsignedp
7714 && inter_prec < final_prec)
7715 && ((inter_unsignedp && inter_prec > inside_prec)
7716 == (final_unsignedp && final_prec > inter_prec))
7717 && ! (inside_ptr && inter_prec != final_prec)
7718 && ! (final_ptr && inside_prec != inter_prec)
7719 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
7720 && TYPE_MODE (type) == TYPE_MODE (inter_type))
7721 && final_ptr == inside_ptr
7723 && TREE_CODE (TREE_TYPE (inside_type)) == ARRAY_TYPE
7724 && TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
7725 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
7728 /* Handle (T *)&A.B.C for A being of type T and B and C
7729 living at offset zero. This occurs frequently in
7730 C++ upcasting and then accessing the base. */
7731 if (TREE_CODE (op0) == ADDR_EXPR
7732 && POINTER_TYPE_P (type)
7733 && handled_component_p (TREE_OPERAND (op0, 0)))
7735 HOST_WIDE_INT bitsize, bitpos;
7737 enum machine_mode mode;
7738 int unsignedp, volatilep;
7739 tree base = TREE_OPERAND (op0, 0);
7740 base = get_inner_reference (base, &bitsize, &bitpos, &offset,
7741 &mode, &unsignedp, &volatilep, false);
7742 /* If the reference was to a (constant) zero offset, we can use
7743 the address of the base if it has the same base type
7744 as the result type. */
7745 if (! offset && bitpos == 0
7746 && TYPE_MAIN_VARIANT (TREE_TYPE (type))
7747 == TYPE_MAIN_VARIANT (TREE_TYPE (base)))
7748 return fold_convert (type, build_fold_addr_expr (base));
7751 /* Convert (type *)&A into &A->field_of_type_and_offset_0. */
7752 if (TREE_CODE (op0) == ADDR_EXPR && POINTER_TYPE_P (type)
7753 && (tem = maybe_fold_offset_to_component_ref
7754 (TREE_TYPE (TREE_OPERAND (op0, 0)), TREE_OPERAND (op0, 0),
7755 integer_zero_node, TREE_TYPE (type), false)))
7756 return build_fold_addr_expr_with_type (tem, type);
7758 if ((TREE_CODE (op0) == MODIFY_EXPR
7759 || TREE_CODE (op0) == GIMPLE_MODIFY_STMT)
7760 && TREE_CONSTANT (GENERIC_TREE_OPERAND (op0, 1))
7761 /* Detect assigning a bitfield. */
7762 && !(TREE_CODE (GENERIC_TREE_OPERAND (op0, 0)) == COMPONENT_REF
7764 (TREE_OPERAND (GENERIC_TREE_OPERAND (op0, 0), 1))))
7766 /* Don't leave an assignment inside a conversion
7767 unless assigning a bitfield. */
7768 tem = fold_build1 (code, type, GENERIC_TREE_OPERAND (op0, 1));
7769 /* First do the assignment, then return converted constant. */
7770 tem = build2 (COMPOUND_EXPR, TREE_TYPE (tem), op0, tem);
7771 TREE_NO_WARNING (tem) = 1;
7772 TREE_USED (tem) = 1;
7776 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
7777 constants (if x has signed type, the sign bit cannot be set
7778 in c). This folds extension into the BIT_AND_EXPR. */
7779 if (INTEGRAL_TYPE_P (type)
7780 && TREE_CODE (type) != BOOLEAN_TYPE
7781 && TREE_CODE (op0) == BIT_AND_EXPR
7782 && TREE_CODE (TREE_OPERAND (op0, 1)) == INTEGER_CST)
7785 tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
7788 if (TYPE_UNSIGNED (TREE_TYPE (and))
7789 || (TYPE_PRECISION (type)
7790 <= TYPE_PRECISION (TREE_TYPE (and))))
7792 else if (TYPE_PRECISION (TREE_TYPE (and1))
7793 <= HOST_BITS_PER_WIDE_INT
7794 && host_integerp (and1, 1))
7796 unsigned HOST_WIDE_INT cst;
7798 cst = tree_low_cst (and1, 1);
7799 cst &= (HOST_WIDE_INT) -1
7800 << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
7801 change = (cst == 0);
7802 #ifdef LOAD_EXTEND_OP
7804 && !flag_syntax_only
7805 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
7808 tree uns = lang_hooks.types.unsigned_type (TREE_TYPE (and0));
7809 and0 = fold_convert (uns, and0);
7810 and1 = fold_convert (uns, and1);
7816 tem = force_fit_type_double (type, TREE_INT_CST_LOW (and1),
7817 TREE_INT_CST_HIGH (and1), 0,
7818 TREE_OVERFLOW (and1));
7819 return fold_build2 (BIT_AND_EXPR, type,
7820 fold_convert (type, and0), tem);
7824 /* Convert (T1)((T2)X op Y) into (T1)X op Y, for pointer types T1 and
7825 T2 being pointers to types of the same size. */
7826 if (POINTER_TYPE_P (type)
7827 && BINARY_CLASS_P (arg0)
7828 && TREE_CODE (TREE_OPERAND (arg0, 0)) == NOP_EXPR
7829 && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 0))))
7831 tree arg00 = TREE_OPERAND (arg0, 0);
7833 tree t1 = TREE_TYPE (arg00);
7834 tree tt0 = TREE_TYPE (t0);
7835 tree tt1 = TREE_TYPE (t1);
7836 tree s0 = TYPE_SIZE (tt0);
7837 tree s1 = TYPE_SIZE (tt1);
7839 if (s0 && s1 && operand_equal_p (s0, s1, OEP_ONLY_CONST))
7840 return build2 (TREE_CODE (arg0), t0, fold_convert (t0, arg00),
7841 TREE_OPERAND (arg0, 1));
7844 /* Convert (T1)(~(T2)X) into ~(T1)X if T1 and T2 are integral types
7845 of the same precision, and X is a integer type not narrower than
7846 types T1 or T2, i.e. the cast (T2)X isn't an extension. */
7847 if (INTEGRAL_TYPE_P (type)
7848 && TREE_CODE (op0) == BIT_NOT_EXPR
7849 && INTEGRAL_TYPE_P (TREE_TYPE (op0))
7850 && (TREE_CODE (TREE_OPERAND (op0, 0)) == NOP_EXPR
7851 || TREE_CODE (TREE_OPERAND (op0, 0)) == CONVERT_EXPR)
7852 && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (op0)))
7854 tem = TREE_OPERAND (TREE_OPERAND (op0, 0), 0);
7855 if (INTEGRAL_TYPE_P (TREE_TYPE (tem))
7856 && TYPE_PRECISION (type) <= TYPE_PRECISION (TREE_TYPE (tem)))
7857 return fold_build1 (BIT_NOT_EXPR, type, fold_convert (type, tem));
7860 tem = fold_convert_const (code, type, op0);
7861 return tem ? tem : NULL_TREE;
7863 case VIEW_CONVERT_EXPR:
7864 if (TREE_TYPE (op0) == type)
7866 if (TREE_CODE (op0) == VIEW_CONVERT_EXPR)
7867 return fold_build1 (VIEW_CONVERT_EXPR, type, TREE_OPERAND (op0, 0));
7868 return fold_view_convert_expr (type, op0);
7871 tem = fold_negate_expr (arg0);
7873 return fold_convert (type, tem);
7877 if (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST)
7878 return fold_abs_const (arg0, type);
7879 else if (TREE_CODE (arg0) == NEGATE_EXPR)
7880 return fold_build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0));
7881 /* Convert fabs((double)float) into (double)fabsf(float). */
7882 else if (TREE_CODE (arg0) == NOP_EXPR
7883 && TREE_CODE (type) == REAL_TYPE)
7885 tree targ0 = strip_float_extensions (arg0);
7887 return fold_convert (type, fold_build1 (ABS_EXPR,
7891 /* ABS_EXPR<ABS_EXPR<x>> = ABS_EXPR<x> even if flag_wrapv is on. */
7892 else if (TREE_CODE (arg0) == ABS_EXPR)
7894 else if (tree_expr_nonnegative_p (arg0))
7897 /* Strip sign ops from argument. */
7898 if (TREE_CODE (type) == REAL_TYPE)
7900 tem = fold_strip_sign_ops (arg0);
7902 return fold_build1 (ABS_EXPR, type, fold_convert (type, tem));
7907 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7908 return fold_convert (type, arg0);
7909 if (TREE_CODE (arg0) == COMPLEX_EXPR)
7911 tree itype = TREE_TYPE (type);
7912 tree rpart = fold_convert (itype, TREE_OPERAND (arg0, 0));
7913 tree ipart = fold_convert (itype, TREE_OPERAND (arg0, 1));
7914 return fold_build2 (COMPLEX_EXPR, type, rpart, negate_expr (ipart));
7916 if (TREE_CODE (arg0) == COMPLEX_CST)
7918 tree itype = TREE_TYPE (type);
7919 tree rpart = fold_convert (itype, TREE_REALPART (arg0));
7920 tree ipart = fold_convert (itype, TREE_IMAGPART (arg0));
7921 return build_complex (type, rpart, negate_expr (ipart));
7923 if (TREE_CODE (arg0) == CONJ_EXPR)
7924 return fold_convert (type, TREE_OPERAND (arg0, 0));
7928 if (TREE_CODE (arg0) == INTEGER_CST)
7929 return fold_not_const (arg0, type);
7930 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
7931 return TREE_OPERAND (arg0, 0);
7932 /* Convert ~ (-A) to A - 1. */
7933 else if (INTEGRAL_TYPE_P (type) && TREE_CODE (arg0) == NEGATE_EXPR)
7934 return fold_build2 (MINUS_EXPR, type, TREE_OPERAND (arg0, 0),
7935 build_int_cst (type, 1));
7936 /* Convert ~ (A - 1) or ~ (A + -1) to -A. */
7937 else if (INTEGRAL_TYPE_P (type)
7938 && ((TREE_CODE (arg0) == MINUS_EXPR
7939 && integer_onep (TREE_OPERAND (arg0, 1)))
7940 || (TREE_CODE (arg0) == PLUS_EXPR
7941 && integer_all_onesp (TREE_OPERAND (arg0, 1)))))
7942 return fold_build1 (NEGATE_EXPR, type, TREE_OPERAND (arg0, 0));
7943 /* Convert ~(X ^ Y) to ~X ^ Y or X ^ ~Y if ~X or ~Y simplify. */
7944 else if (TREE_CODE (arg0) == BIT_XOR_EXPR
7945 && (tem = fold_unary (BIT_NOT_EXPR, type,
7947 TREE_OPERAND (arg0, 0)))))
7948 return fold_build2 (BIT_XOR_EXPR, type, tem,
7949 fold_convert (type, TREE_OPERAND (arg0, 1)));
7950 else if (TREE_CODE (arg0) == BIT_XOR_EXPR
7951 && (tem = fold_unary (BIT_NOT_EXPR, type,
7953 TREE_OPERAND (arg0, 1)))))
7954 return fold_build2 (BIT_XOR_EXPR, type,
7955 fold_convert (type, TREE_OPERAND (arg0, 0)), tem);
7959 case TRUTH_NOT_EXPR:
7960 /* The argument to invert_truthvalue must have Boolean type. */
7961 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
7962 arg0 = fold_convert (boolean_type_node, arg0);
7964 /* Note that the operand of this must be an int
7965 and its values must be 0 or 1.
7966 ("true" is a fixed value perhaps depending on the language,
7967 but we don't handle values other than 1 correctly yet.) */
7968 tem = fold_truth_not_expr (arg0);
7971 return fold_convert (type, tem);
7974 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7975 return fold_convert (type, arg0);
7976 if (TREE_CODE (arg0) == COMPLEX_EXPR)
7977 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
7978 TREE_OPERAND (arg0, 1));
7979 if (TREE_CODE (arg0) == COMPLEX_CST)
7980 return fold_convert (type, TREE_REALPART (arg0));
7981 if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7983 tree itype = TREE_TYPE (TREE_TYPE (arg0));
7984 tem = fold_build2 (TREE_CODE (arg0), itype,
7985 fold_build1 (REALPART_EXPR, itype,
7986 TREE_OPERAND (arg0, 0)),
7987 fold_build1 (REALPART_EXPR, itype,
7988 TREE_OPERAND (arg0, 1)));
7989 return fold_convert (type, tem);
7991 if (TREE_CODE (arg0) == CONJ_EXPR)
7993 tree itype = TREE_TYPE (TREE_TYPE (arg0));
7994 tem = fold_build1 (REALPART_EXPR, itype, TREE_OPERAND (arg0, 0));
7995 return fold_convert (type, tem);
7997 if (TREE_CODE (arg0) == CALL_EXPR)
7999 tree fn = get_callee_fndecl (arg0);
8000 if (DECL_BUILT_IN_CLASS (fn) == BUILT_IN_NORMAL)
8001 switch (DECL_FUNCTION_CODE (fn))
8003 CASE_FLT_FN (BUILT_IN_CEXPI):
8004 fn = mathfn_built_in (type, BUILT_IN_COS);
8006 return build_call_expr (fn, 1, CALL_EXPR_ARG (arg0, 0));
8016 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8017 return fold_convert (type, integer_zero_node);
8018 if (TREE_CODE (arg0) == COMPLEX_EXPR)
8019 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
8020 TREE_OPERAND (arg0, 0));
8021 if (TREE_CODE (arg0) == COMPLEX_CST)
8022 return fold_convert (type, TREE_IMAGPART (arg0));
8023 if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8025 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8026 tem = fold_build2 (TREE_CODE (arg0), itype,
8027 fold_build1 (IMAGPART_EXPR, itype,
8028 TREE_OPERAND (arg0, 0)),
8029 fold_build1 (IMAGPART_EXPR, itype,
8030 TREE_OPERAND (arg0, 1)));
8031 return fold_convert (type, tem);
8033 if (TREE_CODE (arg0) == CONJ_EXPR)
8035 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8036 tem = fold_build1 (IMAGPART_EXPR, itype, TREE_OPERAND (arg0, 0));
8037 return fold_convert (type, negate_expr (tem));
8039 if (TREE_CODE (arg0) == CALL_EXPR)
8041 tree fn = get_callee_fndecl (arg0);
8042 if (DECL_BUILT_IN_CLASS (fn) == BUILT_IN_NORMAL)
8043 switch (DECL_FUNCTION_CODE (fn))
8045 CASE_FLT_FN (BUILT_IN_CEXPI):
8046 fn = mathfn_built_in (type, BUILT_IN_SIN);
8048 return build_call_expr (fn, 1, CALL_EXPR_ARG (arg0, 0));
8059 } /* switch (code) */
8062 /* Fold a binary expression of code CODE and type TYPE with operands
8063 OP0 and OP1, containing either a MIN-MAX or a MAX-MIN combination.
8064 Return the folded expression if folding is successful. Otherwise,
8065 return NULL_TREE. */
8068 fold_minmax (enum tree_code code, tree type, tree op0, tree op1)
8070 enum tree_code compl_code;
8072 if (code == MIN_EXPR)
8073 compl_code = MAX_EXPR;
8074 else if (code == MAX_EXPR)
8075 compl_code = MIN_EXPR;
8079 /* MIN (MAX (a, b), b) == b. */
8080 if (TREE_CODE (op0) == compl_code
8081 && operand_equal_p (TREE_OPERAND (op0, 1), op1, 0))
8082 return omit_one_operand (type, op1, TREE_OPERAND (op0, 0));
8084 /* MIN (MAX (b, a), b) == b. */
8085 if (TREE_CODE (op0) == compl_code
8086 && operand_equal_p (TREE_OPERAND (op0, 0), op1, 0)
8087 && reorder_operands_p (TREE_OPERAND (op0, 1), op1))
8088 return omit_one_operand (type, op1, TREE_OPERAND (op0, 1));
8090 /* MIN (a, MAX (a, b)) == a. */
8091 if (TREE_CODE (op1) == compl_code
8092 && operand_equal_p (op0, TREE_OPERAND (op1, 0), 0)
8093 && reorder_operands_p (op0, TREE_OPERAND (op1, 1)))
8094 return omit_one_operand (type, op0, TREE_OPERAND (op1, 1));
8096 /* MIN (a, MAX (b, a)) == a. */
8097 if (TREE_CODE (op1) == compl_code
8098 && operand_equal_p (op0, TREE_OPERAND (op1, 1), 0)
8099 && reorder_operands_p (op0, TREE_OPERAND (op1, 0)))
8100 return omit_one_operand (type, op0, TREE_OPERAND (op1, 0));
8105 /* Helper that tries to canonicalize the comparison ARG0 CODE ARG1
8106 by changing CODE to reduce the magnitude of constants involved in
8107 ARG0 of the comparison.
8108 Returns a canonicalized comparison tree if a simplification was
8109 possible, otherwise returns NULL_TREE.
8110 Set *STRICT_OVERFLOW_P to true if the canonicalization is only
8111 valid if signed overflow is undefined. */
8114 maybe_canonicalize_comparison_1 (enum tree_code code, tree type,
8115 tree arg0, tree arg1,
8116 bool *strict_overflow_p)
8118 enum tree_code code0 = TREE_CODE (arg0);
8119 tree t, cst0 = NULL_TREE;
8123 /* Match A +- CST code arg1 and CST code arg1. */
8124 if (!(((code0 == MINUS_EXPR
8125 || code0 == PLUS_EXPR)
8126 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8127 || code0 == INTEGER_CST))
8130 /* Identify the constant in arg0 and its sign. */
8131 if (code0 == INTEGER_CST)
8134 cst0 = TREE_OPERAND (arg0, 1);
8135 sgn0 = tree_int_cst_sgn (cst0);
8137 /* Overflowed constants and zero will cause problems. */
8138 if (integer_zerop (cst0)
8139 || TREE_OVERFLOW (cst0))
8142 /* See if we can reduce the magnitude of the constant in
8143 arg0 by changing the comparison code. */
8144 if (code0 == INTEGER_CST)
8146 /* CST <= arg1 -> CST-1 < arg1. */
8147 if (code == LE_EXPR && sgn0 == 1)
8149 /* -CST < arg1 -> -CST-1 <= arg1. */
8150 else if (code == LT_EXPR && sgn0 == -1)
8152 /* CST > arg1 -> CST-1 >= arg1. */
8153 else if (code == GT_EXPR && sgn0 == 1)
8155 /* -CST >= arg1 -> -CST-1 > arg1. */
8156 else if (code == GE_EXPR && sgn0 == -1)
8160 /* arg1 code' CST' might be more canonical. */
8165 /* A - CST < arg1 -> A - CST-1 <= arg1. */
8167 && code0 == ((sgn0 == -1) ? PLUS_EXPR : MINUS_EXPR))
8169 /* A + CST > arg1 -> A + CST-1 >= arg1. */
8170 else if (code == GT_EXPR
8171 && code0 == ((sgn0 == -1) ? MINUS_EXPR : PLUS_EXPR))
8173 /* A + CST <= arg1 -> A + CST-1 < arg1. */
8174 else if (code == LE_EXPR
8175 && code0 == ((sgn0 == -1) ? MINUS_EXPR : PLUS_EXPR))
8177 /* A - CST >= arg1 -> A - CST-1 > arg1. */
8178 else if (code == GE_EXPR
8179 && code0 == ((sgn0 == -1) ? PLUS_EXPR : MINUS_EXPR))
8183 *strict_overflow_p = true;
8186 /* Now build the constant reduced in magnitude. */
8187 t = int_const_binop (sgn0 == -1 ? PLUS_EXPR : MINUS_EXPR,
8188 cst0, build_int_cst (TREE_TYPE (cst0), 1), 0);
8189 if (code0 != INTEGER_CST)
8190 t = fold_build2 (code0, TREE_TYPE (arg0), TREE_OPERAND (arg0, 0), t);
8192 /* If swapping might yield to a more canonical form, do so. */
8194 return fold_build2 (swap_tree_comparison (code), type, arg1, t);
8196 return fold_build2 (code, type, t, arg1);
8199 /* Canonicalize the comparison ARG0 CODE ARG1 with type TYPE with undefined
8200 overflow further. Try to decrease the magnitude of constants involved
8201 by changing LE_EXPR and GE_EXPR to LT_EXPR and GT_EXPR or vice versa
8202 and put sole constants at the second argument position.
8203 Returns the canonicalized tree if changed, otherwise NULL_TREE. */
8206 maybe_canonicalize_comparison (enum tree_code code, tree type,
8207 tree arg0, tree arg1)
8210 bool strict_overflow_p;
8211 const char * const warnmsg = G_("assuming signed overflow does not occur "
8212 "when reducing constant in comparison");
8214 /* In principle pointers also have undefined overflow behavior,
8215 but that causes problems elsewhere. */
8216 if (!TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))
8217 || POINTER_TYPE_P (TREE_TYPE (arg0)))
8220 /* Try canonicalization by simplifying arg0. */
8221 strict_overflow_p = false;
8222 t = maybe_canonicalize_comparison_1 (code, type, arg0, arg1,
8223 &strict_overflow_p);
8226 if (strict_overflow_p)
8227 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MAGNITUDE);
8231 /* Try canonicalization by simplifying arg1 using the swapped
8233 code = swap_tree_comparison (code);
8234 strict_overflow_p = false;
8235 t = maybe_canonicalize_comparison_1 (code, type, arg1, arg0,
8236 &strict_overflow_p);
8237 if (t && strict_overflow_p)
8238 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MAGNITUDE);
8242 /* Subroutine of fold_binary. This routine performs all of the
8243 transformations that are common to the equality/inequality
8244 operators (EQ_EXPR and NE_EXPR) and the ordering operators
8245 (LT_EXPR, LE_EXPR, GE_EXPR and GT_EXPR). Callers other than
8246 fold_binary should call fold_binary. Fold a comparison with
8247 tree code CODE and type TYPE with operands OP0 and OP1. Return
8248 the folded comparison or NULL_TREE. */
8251 fold_comparison (enum tree_code code, tree type, tree op0, tree op1)
8253 tree arg0, arg1, tem;
8258 STRIP_SIGN_NOPS (arg0);
8259 STRIP_SIGN_NOPS (arg1);
8261 tem = fold_relational_const (code, type, arg0, arg1);
8262 if (tem != NULL_TREE)
8265 /* If one arg is a real or integer constant, put it last. */
8266 if (tree_swap_operands_p (arg0, arg1, true))
8267 return fold_build2 (swap_tree_comparison (code), type, op1, op0);
8269 /* Transform comparisons of the form X +- C1 CMP C2 to X CMP C2 +- C1. */
8270 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8271 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8272 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
8273 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
8274 && (TREE_CODE (arg1) == INTEGER_CST
8275 && !TREE_OVERFLOW (arg1)))
8277 tree const1 = TREE_OPERAND (arg0, 1);
8279 tree variable = TREE_OPERAND (arg0, 0);
8282 lhs_add = TREE_CODE (arg0) != PLUS_EXPR;
8284 lhs = fold_build2 (lhs_add ? PLUS_EXPR : MINUS_EXPR,
8285 TREE_TYPE (arg1), const2, const1);
8287 /* If the constant operation overflowed this can be
8288 simplified as a comparison against INT_MAX/INT_MIN. */
8289 if (TREE_CODE (lhs) == INTEGER_CST
8290 && TREE_OVERFLOW (lhs))
8292 int const1_sgn = tree_int_cst_sgn (const1);
8293 enum tree_code code2 = code;
8295 /* Get the sign of the constant on the lhs if the
8296 operation were VARIABLE + CONST1. */
8297 if (TREE_CODE (arg0) == MINUS_EXPR)
8298 const1_sgn = -const1_sgn;
8300 /* The sign of the constant determines if we overflowed
8301 INT_MAX (const1_sgn == -1) or INT_MIN (const1_sgn == 1).
8302 Canonicalize to the INT_MIN overflow by swapping the comparison
8304 if (const1_sgn == -1)
8305 code2 = swap_tree_comparison (code);
8307 /* We now can look at the canonicalized case
8308 VARIABLE + 1 CODE2 INT_MIN
8309 and decide on the result. */
8310 if (code2 == LT_EXPR
8312 || code2 == EQ_EXPR)
8313 return omit_one_operand (type, boolean_false_node, variable);
8314 else if (code2 == NE_EXPR
8316 || code2 == GT_EXPR)
8317 return omit_one_operand (type, boolean_true_node, variable);
8320 if (TREE_CODE (lhs) == TREE_CODE (arg1)
8321 && (TREE_CODE (lhs) != INTEGER_CST
8322 || !TREE_OVERFLOW (lhs)))
8324 fold_overflow_warning (("assuming signed overflow does not occur "
8325 "when changing X +- C1 cmp C2 to "
8327 WARN_STRICT_OVERFLOW_COMPARISON);
8328 return fold_build2 (code, type, variable, lhs);
8332 /* For comparisons of pointers we can decompose it to a compile time
8333 comparison of the base objects and the offsets into the object.
8334 This requires at least one operand being an ADDR_EXPR to do more
8335 than the operand_equal_p test below. */
8336 if (POINTER_TYPE_P (TREE_TYPE (arg0))
8337 && (TREE_CODE (arg0) == ADDR_EXPR
8338 || TREE_CODE (arg1) == ADDR_EXPR))
8340 tree base0, base1, offset0 = NULL_TREE, offset1 = NULL_TREE;
8341 HOST_WIDE_INT bitsize, bitpos0 = 0, bitpos1 = 0;
8342 enum machine_mode mode;
8343 int volatilep, unsignedp;
8344 bool indirect_base0 = false;
8346 /* Get base and offset for the access. Strip ADDR_EXPR for
8347 get_inner_reference, but put it back by stripping INDIRECT_REF
8348 off the base object if possible. */
8350 if (TREE_CODE (arg0) == ADDR_EXPR)
8352 base0 = get_inner_reference (TREE_OPERAND (arg0, 0),
8353 &bitsize, &bitpos0, &offset0, &mode,
8354 &unsignedp, &volatilep, false);
8355 if (TREE_CODE (base0) == INDIRECT_REF)
8356 base0 = TREE_OPERAND (base0, 0);
8358 indirect_base0 = true;
8362 if (TREE_CODE (arg1) == ADDR_EXPR)
8364 base1 = get_inner_reference (TREE_OPERAND (arg1, 0),
8365 &bitsize, &bitpos1, &offset1, &mode,
8366 &unsignedp, &volatilep, false);
8367 /* We have to make sure to have an indirect/non-indirect base1
8368 just the same as we did for base0. */
8369 if (TREE_CODE (base1) == INDIRECT_REF
8371 base1 = TREE_OPERAND (base1, 0);
8372 else if (!indirect_base0)
8375 else if (indirect_base0)
8378 /* If we have equivalent bases we might be able to simplify. */
8380 && operand_equal_p (base0, base1, 0))
8382 /* We can fold this expression to a constant if the non-constant
8383 offset parts are equal. */
8384 if (offset0 == offset1
8385 || (offset0 && offset1
8386 && operand_equal_p (offset0, offset1, 0)))
8391 return build_int_cst (boolean_type_node, bitpos0 == bitpos1);
8393 return build_int_cst (boolean_type_node, bitpos0 != bitpos1);
8395 return build_int_cst (boolean_type_node, bitpos0 < bitpos1);
8397 return build_int_cst (boolean_type_node, bitpos0 <= bitpos1);
8399 return build_int_cst (boolean_type_node, bitpos0 >= bitpos1);
8401 return build_int_cst (boolean_type_node, bitpos0 > bitpos1);
8405 /* We can simplify the comparison to a comparison of the variable
8406 offset parts if the constant offset parts are equal.
8407 Be careful to use signed size type here because otherwise we
8408 mess with array offsets in the wrong way. This is possible
8409 because pointer arithmetic is restricted to retain within an
8410 object and overflow on pointer differences is undefined as of
8411 6.5.6/8 and /9 with respect to the signed ptrdiff_t. */
8412 else if (bitpos0 == bitpos1)
8414 tree signed_size_type_node;
8415 signed_size_type_node = signed_type_for (size_type_node);
8417 /* By converting to signed size type we cover middle-end pointer
8418 arithmetic which operates on unsigned pointer types of size
8419 type size and ARRAY_REF offsets which are properly sign or
8420 zero extended from their type in case it is narrower than
8422 if (offset0 == NULL_TREE)
8423 offset0 = build_int_cst (signed_size_type_node, 0);
8425 offset0 = fold_convert (signed_size_type_node, offset0);
8426 if (offset1 == NULL_TREE)
8427 offset1 = build_int_cst (signed_size_type_node, 0);
8429 offset1 = fold_convert (signed_size_type_node, offset1);
8431 return fold_build2 (code, type, offset0, offset1);
8436 /* If this is a comparison of two exprs that look like an ARRAY_REF of the
8437 same object, then we can fold this to a comparison of the two offsets in
8438 signed size type. This is possible because pointer arithmetic is
8439 restricted to retain within an object and overflow on pointer differences
8440 is undefined as of 6.5.6/8 and /9 with respect to the signed ptrdiff_t.
8442 We check flag_wrapv directly because pointers types are unsigned,
8443 and therefore TYPE_OVERFLOW_WRAPS returns true for them. That is
8444 normally what we want to avoid certain odd overflow cases, but
8446 if (POINTER_TYPE_P (TREE_TYPE (arg0))
8448 && !TYPE_OVERFLOW_TRAPS (TREE_TYPE (arg0)))
8450 tree base0, offset0, base1, offset1;
8452 if (extract_array_ref (arg0, &base0, &offset0)
8453 && extract_array_ref (arg1, &base1, &offset1)
8454 && operand_equal_p (base0, base1, 0))
8456 tree signed_size_type_node;
8457 signed_size_type_node = signed_type_for (size_type_node);
8459 /* By converting to signed size type we cover middle-end pointer
8460 arithmetic which operates on unsigned pointer types of size
8461 type size and ARRAY_REF offsets which are properly sign or
8462 zero extended from their type in case it is narrower than
8464 if (offset0 == NULL_TREE)
8465 offset0 = build_int_cst (signed_size_type_node, 0);
8467 offset0 = fold_convert (signed_size_type_node, offset0);
8468 if (offset1 == NULL_TREE)
8469 offset1 = build_int_cst (signed_size_type_node, 0);
8471 offset1 = fold_convert (signed_size_type_node, offset1);
8473 return fold_build2 (code, type, offset0, offset1);
8477 /* Transform comparisons of the form X +- C1 CMP Y +- C2 to
8478 X CMP Y +- C2 +- C1 for signed X, Y. This is valid if
8479 the resulting offset is smaller in absolute value than the
8481 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))
8482 && (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8483 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8484 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1)))
8485 && (TREE_CODE (arg1) == PLUS_EXPR || TREE_CODE (arg1) == MINUS_EXPR)
8486 && (TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
8487 && !TREE_OVERFLOW (TREE_OPERAND (arg1, 1))))
8489 tree const1 = TREE_OPERAND (arg0, 1);
8490 tree const2 = TREE_OPERAND (arg1, 1);
8491 tree variable1 = TREE_OPERAND (arg0, 0);
8492 tree variable2 = TREE_OPERAND (arg1, 0);
8494 const char * const warnmsg = G_("assuming signed overflow does not "
8495 "occur when combining constants around "
8498 /* Put the constant on the side where it doesn't overflow and is
8499 of lower absolute value than before. */
8500 cst = int_const_binop (TREE_CODE (arg0) == TREE_CODE (arg1)
8501 ? MINUS_EXPR : PLUS_EXPR,
8503 if (!TREE_OVERFLOW (cst)
8504 && tree_int_cst_compare (const2, cst) == tree_int_cst_sgn (const2))
8506 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
8507 return fold_build2 (code, type,
8509 fold_build2 (TREE_CODE (arg1), TREE_TYPE (arg1),
8513 cst = int_const_binop (TREE_CODE (arg0) == TREE_CODE (arg1)
8514 ? MINUS_EXPR : PLUS_EXPR,
8516 if (!TREE_OVERFLOW (cst)
8517 && tree_int_cst_compare (const1, cst) == tree_int_cst_sgn (const1))
8519 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
8520 return fold_build2 (code, type,
8521 fold_build2 (TREE_CODE (arg0), TREE_TYPE (arg0),
8527 /* Transform comparisons of the form X * C1 CMP 0 to X CMP 0 in the
8528 signed arithmetic case. That form is created by the compiler
8529 often enough for folding it to be of value. One example is in
8530 computing loop trip counts after Operator Strength Reduction. */
8531 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))
8532 && TREE_CODE (arg0) == MULT_EXPR
8533 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8534 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1)))
8535 && integer_zerop (arg1))
8537 tree const1 = TREE_OPERAND (arg0, 1);
8538 tree const2 = arg1; /* zero */
8539 tree variable1 = TREE_OPERAND (arg0, 0);
8540 enum tree_code cmp_code = code;
8542 gcc_assert (!integer_zerop (const1));
8544 fold_overflow_warning (("assuming signed overflow does not occur when "
8545 "eliminating multiplication in comparison "
8547 WARN_STRICT_OVERFLOW_COMPARISON);
8549 /* If const1 is negative we swap the sense of the comparison. */
8550 if (tree_int_cst_sgn (const1) < 0)
8551 cmp_code = swap_tree_comparison (cmp_code);
8553 return fold_build2 (cmp_code, type, variable1, const2);
8556 tem = maybe_canonicalize_comparison (code, type, arg0, arg1);
8560 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
8562 tree targ0 = strip_float_extensions (arg0);
8563 tree targ1 = strip_float_extensions (arg1);
8564 tree newtype = TREE_TYPE (targ0);
8566 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
8567 newtype = TREE_TYPE (targ1);
8569 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
8570 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
8571 return fold_build2 (code, type, fold_convert (newtype, targ0),
8572 fold_convert (newtype, targ1));
8574 /* (-a) CMP (-b) -> b CMP a */
8575 if (TREE_CODE (arg0) == NEGATE_EXPR
8576 && TREE_CODE (arg1) == NEGATE_EXPR)
8577 return fold_build2 (code, type, TREE_OPERAND (arg1, 0),
8578 TREE_OPERAND (arg0, 0));
8580 if (TREE_CODE (arg1) == REAL_CST)
8582 REAL_VALUE_TYPE cst;
8583 cst = TREE_REAL_CST (arg1);
8585 /* (-a) CMP CST -> a swap(CMP) (-CST) */
8586 if (TREE_CODE (arg0) == NEGATE_EXPR)
8587 return fold_build2 (swap_tree_comparison (code), type,
8588 TREE_OPERAND (arg0, 0),
8589 build_real (TREE_TYPE (arg1),
8590 REAL_VALUE_NEGATE (cst)));
8592 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
8593 /* a CMP (-0) -> a CMP 0 */
8594 if (REAL_VALUE_MINUS_ZERO (cst))
8595 return fold_build2 (code, type, arg0,
8596 build_real (TREE_TYPE (arg1), dconst0));
8598 /* x != NaN is always true, other ops are always false. */
8599 if (REAL_VALUE_ISNAN (cst)
8600 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))))
8602 tem = (code == NE_EXPR) ? integer_one_node : integer_zero_node;
8603 return omit_one_operand (type, tem, arg0);
8606 /* Fold comparisons against infinity. */
8607 if (REAL_VALUE_ISINF (cst))
8609 tem = fold_inf_compare (code, type, arg0, arg1);
8610 if (tem != NULL_TREE)
8615 /* If this is a comparison of a real constant with a PLUS_EXPR
8616 or a MINUS_EXPR of a real constant, we can convert it into a
8617 comparison with a revised real constant as long as no overflow
8618 occurs when unsafe_math_optimizations are enabled. */
8619 if (flag_unsafe_math_optimizations
8620 && TREE_CODE (arg1) == REAL_CST
8621 && (TREE_CODE (arg0) == PLUS_EXPR
8622 || TREE_CODE (arg0) == MINUS_EXPR)
8623 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
8624 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
8625 ? MINUS_EXPR : PLUS_EXPR,
8626 arg1, TREE_OPERAND (arg0, 1), 0))
8627 && !TREE_OVERFLOW (tem))
8628 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
8630 /* Likewise, we can simplify a comparison of a real constant with
8631 a MINUS_EXPR whose first operand is also a real constant, i.e.
8632 (c1 - x) < c2 becomes x > c1-c2. */
8633 if (flag_unsafe_math_optimizations
8634 && TREE_CODE (arg1) == REAL_CST
8635 && TREE_CODE (arg0) == MINUS_EXPR
8636 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST
8637 && 0 != (tem = const_binop (MINUS_EXPR, TREE_OPERAND (arg0, 0),
8639 && !TREE_OVERFLOW (tem))
8640 return fold_build2 (swap_tree_comparison (code), type,
8641 TREE_OPERAND (arg0, 1), tem);
8643 /* Fold comparisons against built-in math functions. */
8644 if (TREE_CODE (arg1) == REAL_CST
8645 && flag_unsafe_math_optimizations
8646 && ! flag_errno_math)
8648 enum built_in_function fcode = builtin_mathfn_code (arg0);
8650 if (fcode != END_BUILTINS)
8652 tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
8653 if (tem != NULL_TREE)
8659 /* Convert foo++ == CONST into ++foo == CONST + INCR. */
8660 if (TREE_CONSTANT (arg1)
8661 && (TREE_CODE (arg0) == POSTINCREMENT_EXPR
8662 || TREE_CODE (arg0) == POSTDECREMENT_EXPR)
8663 /* This optimization is invalid for ordered comparisons
8664 if CONST+INCR overflows or if foo+incr might overflow.
8665 This optimization is invalid for floating point due to rounding.
8666 For pointer types we assume overflow doesn't happen. */
8667 && (POINTER_TYPE_P (TREE_TYPE (arg0))
8668 || (INTEGRAL_TYPE_P (TREE_TYPE (arg0))
8669 && (code == EQ_EXPR || code == NE_EXPR))))
8671 tree varop, newconst;
8673 if (TREE_CODE (arg0) == POSTINCREMENT_EXPR)
8675 newconst = fold_build2 (PLUS_EXPR, TREE_TYPE (arg0),
8676 arg1, TREE_OPERAND (arg0, 1));
8677 varop = build2 (PREINCREMENT_EXPR, TREE_TYPE (arg0),
8678 TREE_OPERAND (arg0, 0),
8679 TREE_OPERAND (arg0, 1));
8683 newconst = fold_build2 (MINUS_EXPR, TREE_TYPE (arg0),
8684 arg1, TREE_OPERAND (arg0, 1));
8685 varop = build2 (PREDECREMENT_EXPR, TREE_TYPE (arg0),
8686 TREE_OPERAND (arg0, 0),
8687 TREE_OPERAND (arg0, 1));
8691 /* If VAROP is a reference to a bitfield, we must mask
8692 the constant by the width of the field. */
8693 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
8694 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (varop, 0), 1))
8695 && host_integerp (DECL_SIZE (TREE_OPERAND
8696 (TREE_OPERAND (varop, 0), 1)), 1))
8698 tree fielddecl = TREE_OPERAND (TREE_OPERAND (varop, 0), 1);
8699 HOST_WIDE_INT size = tree_low_cst (DECL_SIZE (fielddecl), 1);
8700 tree folded_compare, shift;
8702 /* First check whether the comparison would come out
8703 always the same. If we don't do that we would
8704 change the meaning with the masking. */
8705 folded_compare = fold_build2 (code, type,
8706 TREE_OPERAND (varop, 0), arg1);
8707 if (TREE_CODE (folded_compare) == INTEGER_CST)
8708 return omit_one_operand (type, folded_compare, varop);
8710 shift = build_int_cst (NULL_TREE,
8711 TYPE_PRECISION (TREE_TYPE (varop)) - size);
8712 shift = fold_convert (TREE_TYPE (varop), shift);
8713 newconst = fold_build2 (LSHIFT_EXPR, TREE_TYPE (varop),
8715 newconst = fold_build2 (RSHIFT_EXPR, TREE_TYPE (varop),
8719 return fold_build2 (code, type, varop, newconst);
8722 if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
8723 && (TREE_CODE (arg0) == NOP_EXPR
8724 || TREE_CODE (arg0) == CONVERT_EXPR))
8726 /* If we are widening one operand of an integer comparison,
8727 see if the other operand is similarly being widened. Perhaps we
8728 can do the comparison in the narrower type. */
8729 tem = fold_widened_comparison (code, type, arg0, arg1);
8733 /* Or if we are changing signedness. */
8734 tem = fold_sign_changed_comparison (code, type, arg0, arg1);
8739 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
8740 constant, we can simplify it. */
8741 if (TREE_CODE (arg1) == INTEGER_CST
8742 && (TREE_CODE (arg0) == MIN_EXPR
8743 || TREE_CODE (arg0) == MAX_EXPR)
8744 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8746 tem = optimize_minmax_comparison (code, type, op0, op1);
8751 /* Simplify comparison of something with itself. (For IEEE
8752 floating-point, we can only do some of these simplifications.) */
8753 if (operand_equal_p (arg0, arg1, 0))
8758 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
8759 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8760 return constant_boolean_node (1, type);
8765 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
8766 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8767 return constant_boolean_node (1, type);
8768 return fold_build2 (EQ_EXPR, type, arg0, arg1);
8771 /* For NE, we can only do this simplification if integer
8772 or we don't honor IEEE floating point NaNs. */
8773 if (FLOAT_TYPE_P (TREE_TYPE (arg0))
8774 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8776 /* ... fall through ... */
8779 return constant_boolean_node (0, type);
8785 /* If we are comparing an expression that just has comparisons
8786 of two integer values, arithmetic expressions of those comparisons,
8787 and constants, we can simplify it. There are only three cases
8788 to check: the two values can either be equal, the first can be
8789 greater, or the second can be greater. Fold the expression for
8790 those three values. Since each value must be 0 or 1, we have
8791 eight possibilities, each of which corresponds to the constant 0
8792 or 1 or one of the six possible comparisons.
8794 This handles common cases like (a > b) == 0 but also handles
8795 expressions like ((x > y) - (y > x)) > 0, which supposedly
8796 occur in macroized code. */
8798 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
8800 tree cval1 = 0, cval2 = 0;
8803 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
8804 /* Don't handle degenerate cases here; they should already
8805 have been handled anyway. */
8806 && cval1 != 0 && cval2 != 0
8807 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
8808 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
8809 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
8810 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
8811 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
8812 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
8813 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
8815 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
8816 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
8818 /* We can't just pass T to eval_subst in case cval1 or cval2
8819 was the same as ARG1. */
8822 = fold_build2 (code, type,
8823 eval_subst (arg0, cval1, maxval,
8827 = fold_build2 (code, type,
8828 eval_subst (arg0, cval1, maxval,
8832 = fold_build2 (code, type,
8833 eval_subst (arg0, cval1, minval,
8837 /* All three of these results should be 0 or 1. Confirm they are.
8838 Then use those values to select the proper code to use. */
8840 if (TREE_CODE (high_result) == INTEGER_CST
8841 && TREE_CODE (equal_result) == INTEGER_CST
8842 && TREE_CODE (low_result) == INTEGER_CST)
8844 /* Make a 3-bit mask with the high-order bit being the
8845 value for `>', the next for '=', and the low for '<'. */
8846 switch ((integer_onep (high_result) * 4)
8847 + (integer_onep (equal_result) * 2)
8848 + integer_onep (low_result))
8852 return omit_one_operand (type, integer_zero_node, arg0);
8873 return omit_one_operand (type, integer_one_node, arg0);
8877 return save_expr (build2 (code, type, cval1, cval2));
8878 return fold_build2 (code, type, cval1, cval2);
8883 /* Fold a comparison of the address of COMPONENT_REFs with the same
8884 type and component to a comparison of the address of the base
8885 object. In short, &x->a OP &y->a to x OP y and
8886 &x->a OP &y.a to x OP &y */
8887 if (TREE_CODE (arg0) == ADDR_EXPR
8888 && TREE_CODE (TREE_OPERAND (arg0, 0)) == COMPONENT_REF
8889 && TREE_CODE (arg1) == ADDR_EXPR
8890 && TREE_CODE (TREE_OPERAND (arg1, 0)) == COMPONENT_REF)
8892 tree cref0 = TREE_OPERAND (arg0, 0);
8893 tree cref1 = TREE_OPERAND (arg1, 0);
8894 if (TREE_OPERAND (cref0, 1) == TREE_OPERAND (cref1, 1))
8896 tree op0 = TREE_OPERAND (cref0, 0);
8897 tree op1 = TREE_OPERAND (cref1, 0);
8898 return fold_build2 (code, type,
8899 build_fold_addr_expr (op0),
8900 build_fold_addr_expr (op1));
8904 /* We can fold X/C1 op C2 where C1 and C2 are integer constants
8905 into a single range test. */
8906 if ((TREE_CODE (arg0) == TRUNC_DIV_EXPR
8907 || TREE_CODE (arg0) == EXACT_DIV_EXPR)
8908 && TREE_CODE (arg1) == INTEGER_CST
8909 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8910 && !integer_zerop (TREE_OPERAND (arg0, 1))
8911 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
8912 && !TREE_OVERFLOW (arg1))
8914 tem = fold_div_compare (code, type, arg0, arg1);
8915 if (tem != NULL_TREE)
8919 /* Fold ~X op ~Y as Y op X. */
8920 if (TREE_CODE (arg0) == BIT_NOT_EXPR
8921 && TREE_CODE (arg1) == BIT_NOT_EXPR)
8923 tree cmp_type = TREE_TYPE (TREE_OPERAND (arg0, 0));
8924 return fold_build2 (code, type,
8925 fold_convert (cmp_type, TREE_OPERAND (arg1, 0)),
8926 TREE_OPERAND (arg0, 0));
8929 /* Fold ~X op C as X op' ~C, where op' is the swapped comparison. */
8930 if (TREE_CODE (arg0) == BIT_NOT_EXPR
8931 && TREE_CODE (arg1) == INTEGER_CST)
8933 tree cmp_type = TREE_TYPE (TREE_OPERAND (arg0, 0));
8934 return fold_build2 (swap_tree_comparison (code), type,
8935 TREE_OPERAND (arg0, 0),
8936 fold_build1 (BIT_NOT_EXPR, cmp_type,
8937 fold_convert (cmp_type, arg1)));
8944 /* Subroutine of fold_binary. Optimize complex multiplications of the
8945 form z * conj(z), as pow(realpart(z),2) + pow(imagpart(z),2). The
8946 argument EXPR represents the expression "z" of type TYPE. */
8949 fold_mult_zconjz (tree type, tree expr)
8951 tree itype = TREE_TYPE (type);
8952 tree rpart, ipart, tem;
8954 if (TREE_CODE (expr) == COMPLEX_EXPR)
8956 rpart = TREE_OPERAND (expr, 0);
8957 ipart = TREE_OPERAND (expr, 1);
8959 else if (TREE_CODE (expr) == COMPLEX_CST)
8961 rpart = TREE_REALPART (expr);
8962 ipart = TREE_IMAGPART (expr);
8966 expr = save_expr (expr);
8967 rpart = fold_build1 (REALPART_EXPR, itype, expr);
8968 ipart = fold_build1 (IMAGPART_EXPR, itype, expr);
8971 rpart = save_expr (rpart);
8972 ipart = save_expr (ipart);
8973 tem = fold_build2 (PLUS_EXPR, itype,
8974 fold_build2 (MULT_EXPR, itype, rpart, rpart),
8975 fold_build2 (MULT_EXPR, itype, ipart, ipart));
8976 return fold_build2 (COMPLEX_EXPR, type, tem,
8977 fold_convert (itype, integer_zero_node));
8981 /* Fold a binary expression of code CODE and type TYPE with operands
8982 OP0 and OP1. Return the folded expression if folding is
8983 successful. Otherwise, return NULL_TREE. */
8986 fold_binary (enum tree_code code, tree type, tree op0, tree op1)
8988 enum tree_code_class kind = TREE_CODE_CLASS (code);
8989 tree arg0, arg1, tem;
8990 tree t1 = NULL_TREE;
8991 bool strict_overflow_p;
8993 gcc_assert ((IS_EXPR_CODE_CLASS (kind)
8994 || IS_GIMPLE_STMT_CODE_CLASS (kind))
8995 && TREE_CODE_LENGTH (code) == 2
8997 && op1 != NULL_TREE);
9002 /* Strip any conversions that don't change the mode. This is
9003 safe for every expression, except for a comparison expression
9004 because its signedness is derived from its operands. So, in
9005 the latter case, only strip conversions that don't change the
9008 Note that this is done as an internal manipulation within the
9009 constant folder, in order to find the simplest representation
9010 of the arguments so that their form can be studied. In any
9011 cases, the appropriate type conversions should be put back in
9012 the tree that will get out of the constant folder. */
9014 if (kind == tcc_comparison)
9016 STRIP_SIGN_NOPS (arg0);
9017 STRIP_SIGN_NOPS (arg1);
9025 /* Note that TREE_CONSTANT isn't enough: static var addresses are
9026 constant but we can't do arithmetic on them. */
9027 if ((TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
9028 || (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
9029 || (TREE_CODE (arg0) == COMPLEX_CST && TREE_CODE (arg1) == COMPLEX_CST)
9030 || (TREE_CODE (arg0) == VECTOR_CST && TREE_CODE (arg1) == VECTOR_CST))
9032 if (kind == tcc_binary)
9033 tem = const_binop (code, arg0, arg1, 0);
9034 else if (kind == tcc_comparison)
9035 tem = fold_relational_const (code, type, arg0, arg1);
9039 if (tem != NULL_TREE)
9041 if (TREE_TYPE (tem) != type)
9042 tem = fold_convert (type, tem);
9047 /* If this is a commutative operation, and ARG0 is a constant, move it
9048 to ARG1 to reduce the number of tests below. */
9049 if (commutative_tree_code (code)
9050 && tree_swap_operands_p (arg0, arg1, true))
9051 return fold_build2 (code, type, op1, op0);
9053 /* ARG0 is the first operand of EXPR, and ARG1 is the second operand.
9055 First check for cases where an arithmetic operation is applied to a
9056 compound, conditional, or comparison operation. Push the arithmetic
9057 operation inside the compound or conditional to see if any folding
9058 can then be done. Convert comparison to conditional for this purpose.
9059 The also optimizes non-constant cases that used to be done in
9062 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
9063 one of the operands is a comparison and the other is a comparison, a
9064 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
9065 code below would make the expression more complex. Change it to a
9066 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
9067 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
9069 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
9070 || code == EQ_EXPR || code == NE_EXPR)
9071 && ((truth_value_p (TREE_CODE (arg0))
9072 && (truth_value_p (TREE_CODE (arg1))
9073 || (TREE_CODE (arg1) == BIT_AND_EXPR
9074 && integer_onep (TREE_OPERAND (arg1, 1)))))
9075 || (truth_value_p (TREE_CODE (arg1))
9076 && (truth_value_p (TREE_CODE (arg0))
9077 || (TREE_CODE (arg0) == BIT_AND_EXPR
9078 && integer_onep (TREE_OPERAND (arg0, 1)))))))
9080 tem = fold_build2 (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
9081 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
9084 fold_convert (boolean_type_node, arg0),
9085 fold_convert (boolean_type_node, arg1));
9087 if (code == EQ_EXPR)
9088 tem = invert_truthvalue (tem);
9090 return fold_convert (type, tem);
9093 if (TREE_CODE_CLASS (code) == tcc_binary
9094 || TREE_CODE_CLASS (code) == tcc_comparison)
9096 if (TREE_CODE (arg0) == COMPOUND_EXPR)
9097 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
9098 fold_build2 (code, type,
9099 TREE_OPERAND (arg0, 1), op1));
9100 if (TREE_CODE (arg1) == COMPOUND_EXPR
9101 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
9102 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
9103 fold_build2 (code, type,
9104 op0, TREE_OPERAND (arg1, 1)));
9106 if (TREE_CODE (arg0) == COND_EXPR || COMPARISON_CLASS_P (arg0))
9108 tem = fold_binary_op_with_conditional_arg (code, type, op0, op1,
9110 /*cond_first_p=*/1);
9111 if (tem != NULL_TREE)
9115 if (TREE_CODE (arg1) == COND_EXPR || COMPARISON_CLASS_P (arg1))
9117 tem = fold_binary_op_with_conditional_arg (code, type, op0, op1,
9119 /*cond_first_p=*/0);
9120 if (tem != NULL_TREE)
9128 /* A + (-B) -> A - B */
9129 if (TREE_CODE (arg1) == NEGATE_EXPR)
9130 return fold_build2 (MINUS_EXPR, type,
9131 fold_convert (type, arg0),
9132 fold_convert (type, TREE_OPERAND (arg1, 0)));
9133 /* (-A) + B -> B - A */
9134 if (TREE_CODE (arg0) == NEGATE_EXPR
9135 && reorder_operands_p (TREE_OPERAND (arg0, 0), arg1))
9136 return fold_build2 (MINUS_EXPR, type,
9137 fold_convert (type, arg1),
9138 fold_convert (type, TREE_OPERAND (arg0, 0)));
9139 /* Convert ~A + 1 to -A. */
9140 if (INTEGRAL_TYPE_P (type)
9141 && TREE_CODE (arg0) == BIT_NOT_EXPR
9142 && integer_onep (arg1))
9143 return fold_build1 (NEGATE_EXPR, type, TREE_OPERAND (arg0, 0));
9145 /* Handle (A1 * C1) + (A2 * C2) with A1, A2 or C1, C2 being the
9147 if ((TREE_CODE (arg0) == MULT_EXPR
9148 || TREE_CODE (arg1) == MULT_EXPR)
9149 && (!FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
9151 tree tem = fold_plusminus_mult_expr (code, type, arg0, arg1);
9156 if (! FLOAT_TYPE_P (type))
9158 if (integer_zerop (arg1))
9159 return non_lvalue (fold_convert (type, arg0));
9162 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9163 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
9164 && !TYPE_OVERFLOW_TRAPS (type))
9166 t1 = build_int_cst_type (type, -1);
9167 return omit_one_operand (type, t1, arg1);
9171 if (TREE_CODE (arg1) == BIT_NOT_EXPR
9172 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)
9173 && !TYPE_OVERFLOW_TRAPS (type))
9175 t1 = build_int_cst_type (type, -1);
9176 return omit_one_operand (type, t1, arg0);
9179 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
9180 with a constant, and the two constants have no bits in common,
9181 we should treat this as a BIT_IOR_EXPR since this may produce more
9183 if (TREE_CODE (arg0) == BIT_AND_EXPR
9184 && TREE_CODE (arg1) == BIT_AND_EXPR
9185 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
9186 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
9187 && integer_zerop (const_binop (BIT_AND_EXPR,
9188 TREE_OPERAND (arg0, 1),
9189 TREE_OPERAND (arg1, 1), 0)))
9191 code = BIT_IOR_EXPR;
9195 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
9196 (plus (plus (mult) (mult)) (foo)) so that we can
9197 take advantage of the factoring cases below. */
9198 if (((TREE_CODE (arg0) == PLUS_EXPR
9199 || TREE_CODE (arg0) == MINUS_EXPR)
9200 && TREE_CODE (arg1) == MULT_EXPR)
9201 || ((TREE_CODE (arg1) == PLUS_EXPR
9202 || TREE_CODE (arg1) == MINUS_EXPR)
9203 && TREE_CODE (arg0) == MULT_EXPR))
9205 tree parg0, parg1, parg, marg;
9206 enum tree_code pcode;
9208 if (TREE_CODE (arg1) == MULT_EXPR)
9209 parg = arg0, marg = arg1;
9211 parg = arg1, marg = arg0;
9212 pcode = TREE_CODE (parg);
9213 parg0 = TREE_OPERAND (parg, 0);
9214 parg1 = TREE_OPERAND (parg, 1);
9218 if (TREE_CODE (parg0) == MULT_EXPR
9219 && TREE_CODE (parg1) != MULT_EXPR)
9220 return fold_build2 (pcode, type,
9221 fold_build2 (PLUS_EXPR, type,
9222 fold_convert (type, parg0),
9223 fold_convert (type, marg)),
9224 fold_convert (type, parg1));
9225 if (TREE_CODE (parg0) != MULT_EXPR
9226 && TREE_CODE (parg1) == MULT_EXPR)
9227 return fold_build2 (PLUS_EXPR, type,
9228 fold_convert (type, parg0),
9229 fold_build2 (pcode, type,
9230 fold_convert (type, marg),
9235 /* Try replacing &a[i1] + c * i2 with &a[i1 + i2], if c is step
9236 of the array. Loop optimizer sometimes produce this type of
9238 if (TREE_CODE (arg0) == ADDR_EXPR)
9240 tem = try_move_mult_to_index (PLUS_EXPR, arg0, arg1);
9242 return fold_convert (type, tem);
9244 else if (TREE_CODE (arg1) == ADDR_EXPR)
9246 tem = try_move_mult_to_index (PLUS_EXPR, arg1, arg0);
9248 return fold_convert (type, tem);
9253 /* See if ARG1 is zero and X + ARG1 reduces to X. */
9254 if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
9255 return non_lvalue (fold_convert (type, arg0));
9257 /* Likewise if the operands are reversed. */
9258 if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
9259 return non_lvalue (fold_convert (type, arg1));
9261 /* Convert X + -C into X - C. */
9262 if (TREE_CODE (arg1) == REAL_CST
9263 && REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1)))
9265 tem = fold_negate_const (arg1, type);
9266 if (!TREE_OVERFLOW (arg1) || !flag_trapping_math)
9267 return fold_build2 (MINUS_EXPR, type,
9268 fold_convert (type, arg0),
9269 fold_convert (type, tem));
9272 /* Fold __complex__ ( x, 0 ) + __complex__ ( 0, y )
9273 to __complex__ ( x, y ). This is not the same for SNaNs or
9274 if signed zeros are involved. */
9275 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
9276 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
9277 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0)))
9279 tree rtype = TREE_TYPE (TREE_TYPE (arg0));
9280 tree arg0r = fold_unary (REALPART_EXPR, rtype, arg0);
9281 tree arg0i = fold_unary (IMAGPART_EXPR, rtype, arg0);
9282 bool arg0rz = false, arg0iz = false;
9283 if ((arg0r && (arg0rz = real_zerop (arg0r)))
9284 || (arg0i && (arg0iz = real_zerop (arg0i))))
9286 tree arg1r = fold_unary (REALPART_EXPR, rtype, arg1);
9287 tree arg1i = fold_unary (IMAGPART_EXPR, rtype, arg1);
9288 if (arg0rz && arg1i && real_zerop (arg1i))
9290 tree rp = arg1r ? arg1r
9291 : build1 (REALPART_EXPR, rtype, arg1);
9292 tree ip = arg0i ? arg0i
9293 : build1 (IMAGPART_EXPR, rtype, arg0);
9294 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
9296 else if (arg0iz && arg1r && real_zerop (arg1r))
9298 tree rp = arg0r ? arg0r
9299 : build1 (REALPART_EXPR, rtype, arg0);
9300 tree ip = arg1i ? arg1i
9301 : build1 (IMAGPART_EXPR, rtype, arg1);
9302 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
9307 if (flag_unsafe_math_optimizations
9308 && (TREE_CODE (arg0) == RDIV_EXPR || TREE_CODE (arg0) == MULT_EXPR)
9309 && (TREE_CODE (arg1) == RDIV_EXPR || TREE_CODE (arg1) == MULT_EXPR)
9310 && (tem = distribute_real_division (code, type, arg0, arg1)))
9313 /* Convert x+x into x*2.0. */
9314 if (operand_equal_p (arg0, arg1, 0)
9315 && SCALAR_FLOAT_TYPE_P (type))
9316 return fold_build2 (MULT_EXPR, type, arg0,
9317 build_real (type, dconst2));
9319 /* Convert a + (b*c + d*e) into (a + b*c) + d*e. */
9320 if (flag_unsafe_math_optimizations
9321 && TREE_CODE (arg1) == PLUS_EXPR
9322 && TREE_CODE (arg0) != MULT_EXPR)
9324 tree tree10 = TREE_OPERAND (arg1, 0);
9325 tree tree11 = TREE_OPERAND (arg1, 1);
9326 if (TREE_CODE (tree11) == MULT_EXPR
9327 && TREE_CODE (tree10) == MULT_EXPR)
9330 tree0 = fold_build2 (PLUS_EXPR, type, arg0, tree10);
9331 return fold_build2 (PLUS_EXPR, type, tree0, tree11);
9334 /* Convert (b*c + d*e) + a into b*c + (d*e +a). */
9335 if (flag_unsafe_math_optimizations
9336 && TREE_CODE (arg0) == PLUS_EXPR
9337 && TREE_CODE (arg1) != MULT_EXPR)
9339 tree tree00 = TREE_OPERAND (arg0, 0);
9340 tree tree01 = TREE_OPERAND (arg0, 1);
9341 if (TREE_CODE (tree01) == MULT_EXPR
9342 && TREE_CODE (tree00) == MULT_EXPR)
9345 tree0 = fold_build2 (PLUS_EXPR, type, tree01, arg1);
9346 return fold_build2 (PLUS_EXPR, type, tree00, tree0);
9352 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
9353 is a rotate of A by C1 bits. */
9354 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
9355 is a rotate of A by B bits. */
9357 enum tree_code code0, code1;
9358 code0 = TREE_CODE (arg0);
9359 code1 = TREE_CODE (arg1);
9360 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
9361 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
9362 && operand_equal_p (TREE_OPERAND (arg0, 0),
9363 TREE_OPERAND (arg1, 0), 0)
9364 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
9366 tree tree01, tree11;
9367 enum tree_code code01, code11;
9369 tree01 = TREE_OPERAND (arg0, 1);
9370 tree11 = TREE_OPERAND (arg1, 1);
9371 STRIP_NOPS (tree01);
9372 STRIP_NOPS (tree11);
9373 code01 = TREE_CODE (tree01);
9374 code11 = TREE_CODE (tree11);
9375 if (code01 == INTEGER_CST
9376 && code11 == INTEGER_CST
9377 && TREE_INT_CST_HIGH (tree01) == 0
9378 && TREE_INT_CST_HIGH (tree11) == 0
9379 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
9380 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
9381 return build2 (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
9382 code0 == LSHIFT_EXPR ? tree01 : tree11);
9383 else if (code11 == MINUS_EXPR)
9385 tree tree110, tree111;
9386 tree110 = TREE_OPERAND (tree11, 0);
9387 tree111 = TREE_OPERAND (tree11, 1);
9388 STRIP_NOPS (tree110);
9389 STRIP_NOPS (tree111);
9390 if (TREE_CODE (tree110) == INTEGER_CST
9391 && 0 == compare_tree_int (tree110,
9393 (TREE_TYPE (TREE_OPERAND
9395 && operand_equal_p (tree01, tree111, 0))
9396 return build2 ((code0 == LSHIFT_EXPR
9399 type, TREE_OPERAND (arg0, 0), tree01);
9401 else if (code01 == MINUS_EXPR)
9403 tree tree010, tree011;
9404 tree010 = TREE_OPERAND (tree01, 0);
9405 tree011 = TREE_OPERAND (tree01, 1);
9406 STRIP_NOPS (tree010);
9407 STRIP_NOPS (tree011);
9408 if (TREE_CODE (tree010) == INTEGER_CST
9409 && 0 == compare_tree_int (tree010,
9411 (TREE_TYPE (TREE_OPERAND
9413 && operand_equal_p (tree11, tree011, 0))
9414 return build2 ((code0 != LSHIFT_EXPR
9417 type, TREE_OPERAND (arg0, 0), tree11);
9423 /* In most languages, can't associate operations on floats through
9424 parentheses. Rather than remember where the parentheses were, we
9425 don't associate floats at all, unless the user has specified
9426 -funsafe-math-optimizations. */
9428 if (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
9430 tree var0, con0, lit0, minus_lit0;
9431 tree var1, con1, lit1, minus_lit1;
9434 /* Split both trees into variables, constants, and literals. Then
9435 associate each group together, the constants with literals,
9436 then the result with variables. This increases the chances of
9437 literals being recombined later and of generating relocatable
9438 expressions for the sum of a constant and literal. */
9439 var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
9440 var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
9441 code == MINUS_EXPR);
9443 /* With undefined overflow we can only associate constants
9444 with one variable. */
9445 if ((POINTER_TYPE_P (type)
9446 || (INTEGRAL_TYPE_P (type) && !TYPE_OVERFLOW_WRAPS (type)))
9452 if (TREE_CODE (tmp0) == NEGATE_EXPR)
9453 tmp0 = TREE_OPERAND (tmp0, 0);
9454 if (TREE_CODE (tmp1) == NEGATE_EXPR)
9455 tmp1 = TREE_OPERAND (tmp1, 0);
9456 /* The only case we can still associate with two variables
9457 is if they are the same, modulo negation. */
9458 if (!operand_equal_p (tmp0, tmp1, 0))
9462 /* Only do something if we found more than two objects. Otherwise,
9463 nothing has changed and we risk infinite recursion. */
9465 && (2 < ((var0 != 0) + (var1 != 0)
9466 + (con0 != 0) + (con1 != 0)
9467 + (lit0 != 0) + (lit1 != 0)
9468 + (minus_lit0 != 0) + (minus_lit1 != 0))))
9470 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
9471 if (code == MINUS_EXPR)
9474 var0 = associate_trees (var0, var1, code, type);
9475 con0 = associate_trees (con0, con1, code, type);
9476 lit0 = associate_trees (lit0, lit1, code, type);
9477 minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
9479 /* Preserve the MINUS_EXPR if the negative part of the literal is
9480 greater than the positive part. Otherwise, the multiplicative
9481 folding code (i.e extract_muldiv) may be fooled in case
9482 unsigned constants are subtracted, like in the following
9483 example: ((X*2 + 4) - 8U)/2. */
9484 if (minus_lit0 && lit0)
9486 if (TREE_CODE (lit0) == INTEGER_CST
9487 && TREE_CODE (minus_lit0) == INTEGER_CST
9488 && tree_int_cst_lt (lit0, minus_lit0))
9490 minus_lit0 = associate_trees (minus_lit0, lit0,
9496 lit0 = associate_trees (lit0, minus_lit0,
9504 return fold_convert (type,
9505 associate_trees (var0, minus_lit0,
9509 con0 = associate_trees (con0, minus_lit0,
9511 return fold_convert (type,
9512 associate_trees (var0, con0,
9517 con0 = associate_trees (con0, lit0, code, type);
9518 return fold_convert (type, associate_trees (var0, con0,
9526 /* A - (-B) -> A + B */
9527 if (TREE_CODE (arg1) == NEGATE_EXPR)
9528 return fold_build2 (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0));
9529 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
9530 if (TREE_CODE (arg0) == NEGATE_EXPR
9531 && (FLOAT_TYPE_P (type)
9532 || INTEGRAL_TYPE_P (type))
9533 && negate_expr_p (arg1)
9534 && reorder_operands_p (arg0, arg1))
9535 return fold_build2 (MINUS_EXPR, type, negate_expr (arg1),
9536 TREE_OPERAND (arg0, 0));
9537 /* Convert -A - 1 to ~A. */
9538 if (INTEGRAL_TYPE_P (type)
9539 && TREE_CODE (arg0) == NEGATE_EXPR
9540 && integer_onep (arg1)
9541 && !TYPE_OVERFLOW_TRAPS (type))
9542 return fold_build1 (BIT_NOT_EXPR, type,
9543 fold_convert (type, TREE_OPERAND (arg0, 0)));
9545 /* Convert -1 - A to ~A. */
9546 if (INTEGRAL_TYPE_P (type)
9547 && integer_all_onesp (arg0))
9548 return fold_build1 (BIT_NOT_EXPR, type, op1);
9550 if (! FLOAT_TYPE_P (type))
9552 if (integer_zerop (arg0))
9553 return negate_expr (fold_convert (type, arg1));
9554 if (integer_zerop (arg1))
9555 return non_lvalue (fold_convert (type, arg0));
9557 /* Fold A - (A & B) into ~B & A. */
9558 if (!TREE_SIDE_EFFECTS (arg0)
9559 && TREE_CODE (arg1) == BIT_AND_EXPR)
9561 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
9562 return fold_build2 (BIT_AND_EXPR, type,
9563 fold_build1 (BIT_NOT_EXPR, type,
9564 TREE_OPERAND (arg1, 0)),
9566 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
9567 return fold_build2 (BIT_AND_EXPR, type,
9568 fold_build1 (BIT_NOT_EXPR, type,
9569 TREE_OPERAND (arg1, 1)),
9573 /* Fold (A & ~B) - (A & B) into (A ^ B) - B, where B is
9574 any power of 2 minus 1. */
9575 if (TREE_CODE (arg0) == BIT_AND_EXPR
9576 && TREE_CODE (arg1) == BIT_AND_EXPR
9577 && operand_equal_p (TREE_OPERAND (arg0, 0),
9578 TREE_OPERAND (arg1, 0), 0))
9580 tree mask0 = TREE_OPERAND (arg0, 1);
9581 tree mask1 = TREE_OPERAND (arg1, 1);
9582 tree tem = fold_build1 (BIT_NOT_EXPR, type, mask0);
9584 if (operand_equal_p (tem, mask1, 0))
9586 tem = fold_build2 (BIT_XOR_EXPR, type,
9587 TREE_OPERAND (arg0, 0), mask1);
9588 return fold_build2 (MINUS_EXPR, type, tem, mask1);
9593 /* See if ARG1 is zero and X - ARG1 reduces to X. */
9594 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
9595 return non_lvalue (fold_convert (type, arg0));
9597 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
9598 ARG0 is zero and X + ARG0 reduces to X, since that would mean
9599 (-ARG1 + ARG0) reduces to -ARG1. */
9600 else if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
9601 return negate_expr (fold_convert (type, arg1));
9603 /* Fold __complex__ ( x, 0 ) - __complex__ ( 0, y ) to
9604 __complex__ ( x, -y ). This is not the same for SNaNs or if
9605 signed zeros are involved. */
9606 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
9607 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
9608 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0)))
9610 tree rtype = TREE_TYPE (TREE_TYPE (arg0));
9611 tree arg0r = fold_unary (REALPART_EXPR, rtype, arg0);
9612 tree arg0i = fold_unary (IMAGPART_EXPR, rtype, arg0);
9613 bool arg0rz = false, arg0iz = false;
9614 if ((arg0r && (arg0rz = real_zerop (arg0r)))
9615 || (arg0i && (arg0iz = real_zerop (arg0i))))
9617 tree arg1r = fold_unary (REALPART_EXPR, rtype, arg1);
9618 tree arg1i = fold_unary (IMAGPART_EXPR, rtype, arg1);
9619 if (arg0rz && arg1i && real_zerop (arg1i))
9621 tree rp = fold_build1 (NEGATE_EXPR, rtype,
9623 : build1 (REALPART_EXPR, rtype, arg1));
9624 tree ip = arg0i ? arg0i
9625 : build1 (IMAGPART_EXPR, rtype, arg0);
9626 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
9628 else if (arg0iz && arg1r && real_zerop (arg1r))
9630 tree rp = arg0r ? arg0r
9631 : build1 (REALPART_EXPR, rtype, arg0);
9632 tree ip = fold_build1 (NEGATE_EXPR, rtype,
9634 : build1 (IMAGPART_EXPR, rtype, arg1));
9635 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
9640 /* Fold &x - &x. This can happen from &x.foo - &x.
9641 This is unsafe for certain floats even in non-IEEE formats.
9642 In IEEE, it is unsafe because it does wrong for NaNs.
9643 Also note that operand_equal_p is always false if an operand
9646 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
9647 && operand_equal_p (arg0, arg1, 0))
9648 return fold_convert (type, integer_zero_node);
9650 /* A - B -> A + (-B) if B is easily negatable. */
9651 if (negate_expr_p (arg1)
9652 && ((FLOAT_TYPE_P (type)
9653 /* Avoid this transformation if B is a positive REAL_CST. */
9654 && (TREE_CODE (arg1) != REAL_CST
9655 || REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1))))
9656 || INTEGRAL_TYPE_P (type)))
9657 return fold_build2 (PLUS_EXPR, type,
9658 fold_convert (type, arg0),
9659 fold_convert (type, negate_expr (arg1)));
9661 /* Try folding difference of addresses. */
9665 if ((TREE_CODE (arg0) == ADDR_EXPR
9666 || TREE_CODE (arg1) == ADDR_EXPR)
9667 && ptr_difference_const (arg0, arg1, &diff))
9668 return build_int_cst_type (type, diff);
9671 /* Fold &a[i] - &a[j] to i-j. */
9672 if (TREE_CODE (arg0) == ADDR_EXPR
9673 && TREE_CODE (TREE_OPERAND (arg0, 0)) == ARRAY_REF
9674 && TREE_CODE (arg1) == ADDR_EXPR
9675 && TREE_CODE (TREE_OPERAND (arg1, 0)) == ARRAY_REF)
9677 tree aref0 = TREE_OPERAND (arg0, 0);
9678 tree aref1 = TREE_OPERAND (arg1, 0);
9679 if (operand_equal_p (TREE_OPERAND (aref0, 0),
9680 TREE_OPERAND (aref1, 0), 0))
9682 tree op0 = fold_convert (type, TREE_OPERAND (aref0, 1));
9683 tree op1 = fold_convert (type, TREE_OPERAND (aref1, 1));
9684 tree esz = array_ref_element_size (aref0);
9685 tree diff = build2 (MINUS_EXPR, type, op0, op1);
9686 return fold_build2 (MULT_EXPR, type, diff,
9687 fold_convert (type, esz));
9692 /* Try replacing &a[i1] - c * i2 with &a[i1 - i2], if c is step
9693 of the array. Loop optimizer sometimes produce this type of
9695 if (TREE_CODE (arg0) == ADDR_EXPR)
9697 tem = try_move_mult_to_index (MINUS_EXPR, arg0, arg1);
9699 return fold_convert (type, tem);
9702 if (flag_unsafe_math_optimizations
9703 && (TREE_CODE (arg0) == RDIV_EXPR || TREE_CODE (arg0) == MULT_EXPR)
9704 && (TREE_CODE (arg1) == RDIV_EXPR || TREE_CODE (arg1) == MULT_EXPR)
9705 && (tem = distribute_real_division (code, type, arg0, arg1)))
9708 /* Handle (A1 * C1) - (A2 * C2) with A1, A2 or C1, C2 being the
9710 if ((TREE_CODE (arg0) == MULT_EXPR
9711 || TREE_CODE (arg1) == MULT_EXPR)
9712 && (!FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
9714 tree tem = fold_plusminus_mult_expr (code, type, arg0, arg1);
9722 /* (-A) * (-B) -> A * B */
9723 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
9724 return fold_build2 (MULT_EXPR, type,
9725 fold_convert (type, TREE_OPERAND (arg0, 0)),
9726 fold_convert (type, negate_expr (arg1)));
9727 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
9728 return fold_build2 (MULT_EXPR, type,
9729 fold_convert (type, negate_expr (arg0)),
9730 fold_convert (type, TREE_OPERAND (arg1, 0)));
9732 if (! FLOAT_TYPE_P (type))
9734 if (integer_zerop (arg1))
9735 return omit_one_operand (type, arg1, arg0);
9736 if (integer_onep (arg1))
9737 return non_lvalue (fold_convert (type, arg0));
9738 /* Transform x * -1 into -x. */
9739 if (integer_all_onesp (arg1))
9740 return fold_convert (type, negate_expr (arg0));
9741 /* Transform x * -C into -x * C if x is easily negatable. */
9742 if (TREE_CODE (arg1) == INTEGER_CST
9743 && tree_int_cst_sgn (arg1) == -1
9744 && negate_expr_p (arg0)
9745 && (tem = negate_expr (arg1)) != arg1
9746 && !TREE_OVERFLOW (tem))
9747 return fold_build2 (MULT_EXPR, type,
9748 negate_expr (arg0), tem);
9750 /* (a * (1 << b)) is (a << b) */
9751 if (TREE_CODE (arg1) == LSHIFT_EXPR
9752 && integer_onep (TREE_OPERAND (arg1, 0)))
9753 return fold_build2 (LSHIFT_EXPR, type, arg0,
9754 TREE_OPERAND (arg1, 1));
9755 if (TREE_CODE (arg0) == LSHIFT_EXPR
9756 && integer_onep (TREE_OPERAND (arg0, 0)))
9757 return fold_build2 (LSHIFT_EXPR, type, arg1,
9758 TREE_OPERAND (arg0, 1));
9760 strict_overflow_p = false;
9761 if (TREE_CODE (arg1) == INTEGER_CST
9762 && 0 != (tem = extract_muldiv (op0,
9763 fold_convert (type, arg1),
9765 &strict_overflow_p)))
9767 if (strict_overflow_p)
9768 fold_overflow_warning (("assuming signed overflow does not "
9769 "occur when simplifying "
9771 WARN_STRICT_OVERFLOW_MISC);
9772 return fold_convert (type, tem);
9775 /* Optimize z * conj(z) for integer complex numbers. */
9776 if (TREE_CODE (arg0) == CONJ_EXPR
9777 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
9778 return fold_mult_zconjz (type, arg1);
9779 if (TREE_CODE (arg1) == CONJ_EXPR
9780 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
9781 return fold_mult_zconjz (type, arg0);
9785 /* Maybe fold x * 0 to 0. The expressions aren't the same
9786 when x is NaN, since x * 0 is also NaN. Nor are they the
9787 same in modes with signed zeros, since multiplying a
9788 negative value by 0 gives -0, not +0. */
9789 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
9790 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
9791 && real_zerop (arg1))
9792 return omit_one_operand (type, arg1, arg0);
9793 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
9794 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
9795 && real_onep (arg1))
9796 return non_lvalue (fold_convert (type, arg0));
9798 /* Transform x * -1.0 into -x. */
9799 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
9800 && real_minus_onep (arg1))
9801 return fold_convert (type, negate_expr (arg0));
9803 /* Convert (C1/X)*C2 into (C1*C2)/X. */
9804 if (flag_unsafe_math_optimizations
9805 && TREE_CODE (arg0) == RDIV_EXPR
9806 && TREE_CODE (arg1) == REAL_CST
9807 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST)
9809 tree tem = const_binop (MULT_EXPR, TREE_OPERAND (arg0, 0),
9812 return fold_build2 (RDIV_EXPR, type, tem,
9813 TREE_OPERAND (arg0, 1));
9816 /* Strip sign operations from X in X*X, i.e. -Y*-Y -> Y*Y. */
9817 if (operand_equal_p (arg0, arg1, 0))
9819 tree tem = fold_strip_sign_ops (arg0);
9820 if (tem != NULL_TREE)
9822 tem = fold_convert (type, tem);
9823 return fold_build2 (MULT_EXPR, type, tem, tem);
9827 /* Fold z * +-I to __complex__ (-+__imag z, +-__real z).
9828 This is not the same for NaNs or if signed zeros are
9830 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
9831 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
9832 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0))
9833 && TREE_CODE (arg1) == COMPLEX_CST
9834 && real_zerop (TREE_REALPART (arg1)))
9836 tree rtype = TREE_TYPE (TREE_TYPE (arg0));
9837 if (real_onep (TREE_IMAGPART (arg1)))
9838 return fold_build2 (COMPLEX_EXPR, type,
9839 negate_expr (fold_build1 (IMAGPART_EXPR,
9841 fold_build1 (REALPART_EXPR, rtype, arg0));
9842 else if (real_minus_onep (TREE_IMAGPART (arg1)))
9843 return fold_build2 (COMPLEX_EXPR, type,
9844 fold_build1 (IMAGPART_EXPR, rtype, arg0),
9845 negate_expr (fold_build1 (REALPART_EXPR,
9849 /* Optimize z * conj(z) for floating point complex numbers.
9850 Guarded by flag_unsafe_math_optimizations as non-finite
9851 imaginary components don't produce scalar results. */
9852 if (flag_unsafe_math_optimizations
9853 && TREE_CODE (arg0) == CONJ_EXPR
9854 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
9855 return fold_mult_zconjz (type, arg1);
9856 if (flag_unsafe_math_optimizations
9857 && TREE_CODE (arg1) == CONJ_EXPR
9858 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
9859 return fold_mult_zconjz (type, arg0);
9861 if (flag_unsafe_math_optimizations)
9863 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
9864 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
9866 /* Optimizations of root(...)*root(...). */
9867 if (fcode0 == fcode1 && BUILTIN_ROOT_P (fcode0))
9870 tree arg00 = CALL_EXPR_ARG (arg0, 0);
9871 tree arg10 = CALL_EXPR_ARG (arg1, 0);
9873 /* Optimize sqrt(x)*sqrt(x) as x. */
9874 if (BUILTIN_SQRT_P (fcode0)
9875 && operand_equal_p (arg00, arg10, 0)
9876 && ! HONOR_SNANS (TYPE_MODE (type)))
9879 /* Optimize root(x)*root(y) as root(x*y). */
9880 rootfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
9881 arg = fold_build2 (MULT_EXPR, type, arg00, arg10);
9882 return build_call_expr (rootfn, 1, arg);
9885 /* Optimize expN(x)*expN(y) as expN(x+y). */
9886 if (fcode0 == fcode1 && BUILTIN_EXPONENT_P (fcode0))
9888 tree expfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
9889 tree arg = fold_build2 (PLUS_EXPR, type,
9890 CALL_EXPR_ARG (arg0, 0),
9891 CALL_EXPR_ARG (arg1, 0));
9892 return build_call_expr (expfn, 1, arg);
9895 /* Optimizations of pow(...)*pow(...). */
9896 if ((fcode0 == BUILT_IN_POW && fcode1 == BUILT_IN_POW)
9897 || (fcode0 == BUILT_IN_POWF && fcode1 == BUILT_IN_POWF)
9898 || (fcode0 == BUILT_IN_POWL && fcode1 == BUILT_IN_POWL))
9900 tree arg00 = CALL_EXPR_ARG (arg0, 0);
9901 tree arg01 = CALL_EXPR_ARG (arg0, 1);
9902 tree arg10 = CALL_EXPR_ARG (arg1, 0);
9903 tree arg11 = CALL_EXPR_ARG (arg1, 1);
9905 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
9906 if (operand_equal_p (arg01, arg11, 0))
9908 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
9909 tree arg = fold_build2 (MULT_EXPR, type, arg00, arg10);
9910 return build_call_expr (powfn, 2, arg, arg01);
9913 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
9914 if (operand_equal_p (arg00, arg10, 0))
9916 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
9917 tree arg = fold_build2 (PLUS_EXPR, type, arg01, arg11);
9918 return build_call_expr (powfn, 2, arg00, arg);
9922 /* Optimize tan(x)*cos(x) as sin(x). */
9923 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_COS)
9924 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_COSF)
9925 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_COSL)
9926 || (fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_TAN)
9927 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_TANF)
9928 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_TANL))
9929 && operand_equal_p (CALL_EXPR_ARG (arg0, 0),
9930 CALL_EXPR_ARG (arg1, 0), 0))
9932 tree sinfn = mathfn_built_in (type, BUILT_IN_SIN);
9934 if (sinfn != NULL_TREE)
9935 return build_call_expr (sinfn, 1, CALL_EXPR_ARG (arg0, 0));
9938 /* Optimize x*pow(x,c) as pow(x,c+1). */
9939 if (fcode1 == BUILT_IN_POW
9940 || fcode1 == BUILT_IN_POWF
9941 || fcode1 == BUILT_IN_POWL)
9943 tree arg10 = CALL_EXPR_ARG (arg1, 0);
9944 tree arg11 = CALL_EXPR_ARG (arg1, 1);
9945 if (TREE_CODE (arg11) == REAL_CST
9946 && !TREE_OVERFLOW (arg11)
9947 && operand_equal_p (arg0, arg10, 0))
9949 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
9953 c = TREE_REAL_CST (arg11);
9954 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
9955 arg = build_real (type, c);
9956 return build_call_expr (powfn, 2, arg0, arg);
9960 /* Optimize pow(x,c)*x as pow(x,c+1). */
9961 if (fcode0 == BUILT_IN_POW
9962 || fcode0 == BUILT_IN_POWF
9963 || fcode0 == BUILT_IN_POWL)
9965 tree arg00 = CALL_EXPR_ARG (arg0, 0);
9966 tree arg01 = CALL_EXPR_ARG (arg0, 1);
9967 if (TREE_CODE (arg01) == REAL_CST
9968 && !TREE_OVERFLOW (arg01)
9969 && operand_equal_p (arg1, arg00, 0))
9971 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
9975 c = TREE_REAL_CST (arg01);
9976 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
9977 arg = build_real (type, c);
9978 return build_call_expr (powfn, 2, arg1, arg);
9982 /* Optimize x*x as pow(x,2.0), which is expanded as x*x. */
9984 && operand_equal_p (arg0, arg1, 0))
9986 tree powfn = mathfn_built_in (type, BUILT_IN_POW);
9990 tree arg = build_real (type, dconst2);
9991 return build_call_expr (powfn, 2, arg0, arg);
10000 if (integer_all_onesp (arg1))
10001 return omit_one_operand (type, arg1, arg0);
10002 if (integer_zerop (arg1))
10003 return non_lvalue (fold_convert (type, arg0));
10004 if (operand_equal_p (arg0, arg1, 0))
10005 return non_lvalue (fold_convert (type, arg0));
10007 /* ~X | X is -1. */
10008 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10009 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10011 t1 = build_int_cst_type (type, -1);
10012 return omit_one_operand (type, t1, arg1);
10015 /* X | ~X is -1. */
10016 if (TREE_CODE (arg1) == BIT_NOT_EXPR
10017 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10019 t1 = build_int_cst_type (type, -1);
10020 return omit_one_operand (type, t1, arg0);
10023 /* Canonicalize (X & C1) | C2. */
10024 if (TREE_CODE (arg0) == BIT_AND_EXPR
10025 && TREE_CODE (arg1) == INTEGER_CST
10026 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
10028 unsigned HOST_WIDE_INT hi1, lo1, hi2, lo2, mlo, mhi;
10029 int width = TYPE_PRECISION (type);
10030 hi1 = TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1));
10031 lo1 = TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1));
10032 hi2 = TREE_INT_CST_HIGH (arg1);
10033 lo2 = TREE_INT_CST_LOW (arg1);
10035 /* If (C1&C2) == C1, then (X&C1)|C2 becomes (X,C2). */
10036 if ((hi1 & hi2) == hi1 && (lo1 & lo2) == lo1)
10037 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
10039 if (width > HOST_BITS_PER_WIDE_INT)
10041 mhi = (unsigned HOST_WIDE_INT) -1
10042 >> (2 * HOST_BITS_PER_WIDE_INT - width);
10048 mlo = (unsigned HOST_WIDE_INT) -1
10049 >> (HOST_BITS_PER_WIDE_INT - width);
10052 /* If (C1|C2) == ~0 then (X&C1)|C2 becomes X|C2. */
10053 if ((~(hi1 | hi2) & mhi) == 0 && (~(lo1 | lo2) & mlo) == 0)
10054 return fold_build2 (BIT_IOR_EXPR, type,
10055 TREE_OPERAND (arg0, 0), arg1);
10057 /* Minimize the number of bits set in C1, i.e. C1 := C1 & ~C2. */
10060 if ((hi1 & ~hi2) != hi1 || (lo1 & ~lo2) != lo1)
10061 return fold_build2 (BIT_IOR_EXPR, type,
10062 fold_build2 (BIT_AND_EXPR, type,
10063 TREE_OPERAND (arg0, 0),
10064 build_int_cst_wide (type,
10070 /* (X & Y) | Y is (X, Y). */
10071 if (TREE_CODE (arg0) == BIT_AND_EXPR
10072 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10073 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
10074 /* (X & Y) | X is (Y, X). */
10075 if (TREE_CODE (arg0) == BIT_AND_EXPR
10076 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10077 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10078 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 1));
10079 /* X | (X & Y) is (Y, X). */
10080 if (TREE_CODE (arg1) == BIT_AND_EXPR
10081 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)
10082 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 1)))
10083 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 1));
10084 /* X | (Y & X) is (Y, X). */
10085 if (TREE_CODE (arg1) == BIT_AND_EXPR
10086 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10087 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10088 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 0));
10090 t1 = distribute_bit_expr (code, type, arg0, arg1);
10091 if (t1 != NULL_TREE)
10094 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
10096 This results in more efficient code for machines without a NAND
10097 instruction. Combine will canonicalize to the first form
10098 which will allow use of NAND instructions provided by the
10099 backend if they exist. */
10100 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10101 && TREE_CODE (arg1) == BIT_NOT_EXPR)
10103 return fold_build1 (BIT_NOT_EXPR, type,
10104 build2 (BIT_AND_EXPR, type,
10105 TREE_OPERAND (arg0, 0),
10106 TREE_OPERAND (arg1, 0)));
10109 /* See if this can be simplified into a rotate first. If that
10110 is unsuccessful continue in the association code. */
10114 if (integer_zerop (arg1))
10115 return non_lvalue (fold_convert (type, arg0));
10116 if (integer_all_onesp (arg1))
10117 return fold_build1 (BIT_NOT_EXPR, type, arg0);
10118 if (operand_equal_p (arg0, arg1, 0))
10119 return omit_one_operand (type, integer_zero_node, arg0);
10121 /* ~X ^ X is -1. */
10122 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10123 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10125 t1 = build_int_cst_type (type, -1);
10126 return omit_one_operand (type, t1, arg1);
10129 /* X ^ ~X is -1. */
10130 if (TREE_CODE (arg1) == BIT_NOT_EXPR
10131 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10133 t1 = build_int_cst_type (type, -1);
10134 return omit_one_operand (type, t1, arg0);
10137 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
10138 with a constant, and the two constants have no bits in common,
10139 we should treat this as a BIT_IOR_EXPR since this may produce more
10140 simplifications. */
10141 if (TREE_CODE (arg0) == BIT_AND_EXPR
10142 && TREE_CODE (arg1) == BIT_AND_EXPR
10143 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
10144 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
10145 && integer_zerop (const_binop (BIT_AND_EXPR,
10146 TREE_OPERAND (arg0, 1),
10147 TREE_OPERAND (arg1, 1), 0)))
10149 code = BIT_IOR_EXPR;
10153 /* (X | Y) ^ X -> Y & ~ X*/
10154 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10155 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10157 tree t2 = TREE_OPERAND (arg0, 1);
10158 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1),
10160 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
10161 fold_convert (type, t1));
10165 /* (Y | X) ^ X -> Y & ~ X*/
10166 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10167 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10169 tree t2 = TREE_OPERAND (arg0, 0);
10170 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1),
10172 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
10173 fold_convert (type, t1));
10177 /* X ^ (X | Y) -> Y & ~ X*/
10178 if (TREE_CODE (arg1) == BIT_IOR_EXPR
10179 && operand_equal_p (TREE_OPERAND (arg1, 0), arg0, 0))
10181 tree t2 = TREE_OPERAND (arg1, 1);
10182 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg0),
10184 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
10185 fold_convert (type, t1));
10189 /* X ^ (Y | X) -> Y & ~ X*/
10190 if (TREE_CODE (arg1) == BIT_IOR_EXPR
10191 && operand_equal_p (TREE_OPERAND (arg1, 1), arg0, 0))
10193 tree t2 = TREE_OPERAND (arg1, 0);
10194 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg0),
10196 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
10197 fold_convert (type, t1));
10201 /* Convert ~X ^ ~Y to X ^ Y. */
10202 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10203 && TREE_CODE (arg1) == BIT_NOT_EXPR)
10204 return fold_build2 (code, type,
10205 fold_convert (type, TREE_OPERAND (arg0, 0)),
10206 fold_convert (type, TREE_OPERAND (arg1, 0)));
10208 /* Convert ~X ^ C to X ^ ~C. */
10209 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10210 && TREE_CODE (arg1) == INTEGER_CST)
10211 return fold_build2 (code, type,
10212 fold_convert (type, TREE_OPERAND (arg0, 0)),
10213 fold_build1 (BIT_NOT_EXPR, type, arg1));
10215 /* Fold (X & 1) ^ 1 as (X & 1) == 0. */
10216 if (TREE_CODE (arg0) == BIT_AND_EXPR
10217 && integer_onep (TREE_OPERAND (arg0, 1))
10218 && integer_onep (arg1))
10219 return fold_build2 (EQ_EXPR, type, arg0,
10220 build_int_cst (TREE_TYPE (arg0), 0));
10222 /* Fold (X & Y) ^ Y as ~X & Y. */
10223 if (TREE_CODE (arg0) == BIT_AND_EXPR
10224 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10226 tem = fold_convert (type, TREE_OPERAND (arg0, 0));
10227 return fold_build2 (BIT_AND_EXPR, type,
10228 fold_build1 (BIT_NOT_EXPR, type, tem),
10229 fold_convert (type, arg1));
10231 /* Fold (X & Y) ^ X as ~Y & X. */
10232 if (TREE_CODE (arg0) == BIT_AND_EXPR
10233 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10234 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10236 tem = fold_convert (type, TREE_OPERAND (arg0, 1));
10237 return fold_build2 (BIT_AND_EXPR, type,
10238 fold_build1 (BIT_NOT_EXPR, type, tem),
10239 fold_convert (type, arg1));
10241 /* Fold X ^ (X & Y) as X & ~Y. */
10242 if (TREE_CODE (arg1) == BIT_AND_EXPR
10243 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10245 tem = fold_convert (type, TREE_OPERAND (arg1, 1));
10246 return fold_build2 (BIT_AND_EXPR, type,
10247 fold_convert (type, arg0),
10248 fold_build1 (BIT_NOT_EXPR, type, tem));
10250 /* Fold X ^ (Y & X) as ~Y & X. */
10251 if (TREE_CODE (arg1) == BIT_AND_EXPR
10252 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10253 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10255 tem = fold_convert (type, TREE_OPERAND (arg1, 0));
10256 return fold_build2 (BIT_AND_EXPR, type,
10257 fold_build1 (BIT_NOT_EXPR, type, tem),
10258 fold_convert (type, arg0));
10261 /* See if this can be simplified into a rotate first. If that
10262 is unsuccessful continue in the association code. */
10266 if (integer_all_onesp (arg1))
10267 return non_lvalue (fold_convert (type, arg0));
10268 if (integer_zerop (arg1))
10269 return omit_one_operand (type, arg1, arg0);
10270 if (operand_equal_p (arg0, arg1, 0))
10271 return non_lvalue (fold_convert (type, arg0));
10273 /* ~X & X is always zero. */
10274 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10275 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10276 return omit_one_operand (type, integer_zero_node, arg1);
10278 /* X & ~X is always zero. */
10279 if (TREE_CODE (arg1) == BIT_NOT_EXPR
10280 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10281 return omit_one_operand (type, integer_zero_node, arg0);
10283 /* Canonicalize (X | C1) & C2 as (X & C2) | (C1 & C2). */
10284 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10285 && TREE_CODE (arg1) == INTEGER_CST
10286 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
10287 return fold_build2 (BIT_IOR_EXPR, type,
10288 fold_build2 (BIT_AND_EXPR, type,
10289 TREE_OPERAND (arg0, 0), arg1),
10290 fold_build2 (BIT_AND_EXPR, type,
10291 TREE_OPERAND (arg0, 1), arg1));
10293 /* (X | Y) & Y is (X, Y). */
10294 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10295 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10296 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
10297 /* (X | Y) & X is (Y, X). */
10298 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10299 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10300 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10301 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 1));
10302 /* X & (X | Y) is (Y, X). */
10303 if (TREE_CODE (arg1) == BIT_IOR_EXPR
10304 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)
10305 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 1)))
10306 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 1));
10307 /* X & (Y | X) is (Y, X). */
10308 if (TREE_CODE (arg1) == BIT_IOR_EXPR
10309 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10310 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10311 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 0));
10313 /* Fold (X ^ 1) & 1 as (X & 1) == 0. */
10314 if (TREE_CODE (arg0) == BIT_XOR_EXPR
10315 && integer_onep (TREE_OPERAND (arg0, 1))
10316 && integer_onep (arg1))
10318 tem = TREE_OPERAND (arg0, 0);
10319 return fold_build2 (EQ_EXPR, type,
10320 fold_build2 (BIT_AND_EXPR, TREE_TYPE (tem), tem,
10321 build_int_cst (TREE_TYPE (tem), 1)),
10322 build_int_cst (TREE_TYPE (tem), 0));
10324 /* Fold ~X & 1 as (X & 1) == 0. */
10325 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10326 && integer_onep (arg1))
10328 tem = TREE_OPERAND (arg0, 0);
10329 return fold_build2 (EQ_EXPR, type,
10330 fold_build2 (BIT_AND_EXPR, TREE_TYPE (tem), tem,
10331 build_int_cst (TREE_TYPE (tem), 1)),
10332 build_int_cst (TREE_TYPE (tem), 0));
10335 /* Fold (X ^ Y) & Y as ~X & Y. */
10336 if (TREE_CODE (arg0) == BIT_XOR_EXPR
10337 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10339 tem = fold_convert (type, TREE_OPERAND (arg0, 0));
10340 return fold_build2 (BIT_AND_EXPR, type,
10341 fold_build1 (BIT_NOT_EXPR, type, tem),
10342 fold_convert (type, arg1));
10344 /* Fold (X ^ Y) & X as ~Y & X. */
10345 if (TREE_CODE (arg0) == BIT_XOR_EXPR
10346 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10347 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10349 tem = fold_convert (type, TREE_OPERAND (arg0, 1));
10350 return fold_build2 (BIT_AND_EXPR, type,
10351 fold_build1 (BIT_NOT_EXPR, type, tem),
10352 fold_convert (type, arg1));
10354 /* Fold X & (X ^ Y) as X & ~Y. */
10355 if (TREE_CODE (arg1) == BIT_XOR_EXPR
10356 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10358 tem = fold_convert (type, TREE_OPERAND (arg1, 1));
10359 return fold_build2 (BIT_AND_EXPR, type,
10360 fold_convert (type, arg0),
10361 fold_build1 (BIT_NOT_EXPR, type, tem));
10363 /* Fold X & (Y ^ X) as ~Y & X. */
10364 if (TREE_CODE (arg1) == BIT_XOR_EXPR
10365 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10366 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10368 tem = fold_convert (type, TREE_OPERAND (arg1, 0));
10369 return fold_build2 (BIT_AND_EXPR, type,
10370 fold_build1 (BIT_NOT_EXPR, type, tem),
10371 fold_convert (type, arg0));
10374 t1 = distribute_bit_expr (code, type, arg0, arg1);
10375 if (t1 != NULL_TREE)
10377 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
10378 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
10379 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
10382 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
10384 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
10385 && (~TREE_INT_CST_LOW (arg1)
10386 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
10387 return fold_convert (type, TREE_OPERAND (arg0, 0));
10390 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
10392 This results in more efficient code for machines without a NOR
10393 instruction. Combine will canonicalize to the first form
10394 which will allow use of NOR instructions provided by the
10395 backend if they exist. */
10396 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10397 && TREE_CODE (arg1) == BIT_NOT_EXPR)
10399 return fold_build1 (BIT_NOT_EXPR, type,
10400 build2 (BIT_IOR_EXPR, type,
10401 TREE_OPERAND (arg0, 0),
10402 TREE_OPERAND (arg1, 0)));
10408 /* Don't touch a floating-point divide by zero unless the mode
10409 of the constant can represent infinity. */
10410 if (TREE_CODE (arg1) == REAL_CST
10411 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
10412 && real_zerop (arg1))
10415 /* Optimize A / A to 1.0 if we don't care about
10416 NaNs or Infinities. Skip the transformation
10417 for non-real operands. */
10418 if (SCALAR_FLOAT_TYPE_P (TREE_TYPE (arg0))
10419 && ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
10420 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg0)))
10421 && operand_equal_p (arg0, arg1, 0))
10423 tree r = build_real (TREE_TYPE (arg0), dconst1);
10425 return omit_two_operands (type, r, arg0, arg1);
10428 /* The complex version of the above A / A optimization. */
10429 if (COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0))
10430 && operand_equal_p (arg0, arg1, 0))
10432 tree elem_type = TREE_TYPE (TREE_TYPE (arg0));
10433 if (! HONOR_NANS (TYPE_MODE (elem_type))
10434 && ! HONOR_INFINITIES (TYPE_MODE (elem_type)))
10436 tree r = build_real (elem_type, dconst1);
10437 /* omit_two_operands will call fold_convert for us. */
10438 return omit_two_operands (type, r, arg0, arg1);
10442 /* (-A) / (-B) -> A / B */
10443 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
10444 return fold_build2 (RDIV_EXPR, type,
10445 TREE_OPERAND (arg0, 0),
10446 negate_expr (arg1));
10447 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
10448 return fold_build2 (RDIV_EXPR, type,
10449 negate_expr (arg0),
10450 TREE_OPERAND (arg1, 0));
10452 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
10453 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10454 && real_onep (arg1))
10455 return non_lvalue (fold_convert (type, arg0));
10457 /* In IEEE floating point, x/-1 is not equivalent to -x for snans. */
10458 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10459 && real_minus_onep (arg1))
10460 return non_lvalue (fold_convert (type, negate_expr (arg0)));
10462 /* If ARG1 is a constant, we can convert this to a multiply by the
10463 reciprocal. This does not have the same rounding properties,
10464 so only do this if -funsafe-math-optimizations. We can actually
10465 always safely do it if ARG1 is a power of two, but it's hard to
10466 tell if it is or not in a portable manner. */
10467 if (TREE_CODE (arg1) == REAL_CST)
10469 if (flag_unsafe_math_optimizations
10470 && 0 != (tem = const_binop (code, build_real (type, dconst1),
10472 return fold_build2 (MULT_EXPR, type, arg0, tem);
10473 /* Find the reciprocal if optimizing and the result is exact. */
10477 r = TREE_REAL_CST (arg1);
10478 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
10480 tem = build_real (type, r);
10481 return fold_build2 (MULT_EXPR, type,
10482 fold_convert (type, arg0), tem);
10486 /* Convert A/B/C to A/(B*C). */
10487 if (flag_unsafe_math_optimizations
10488 && TREE_CODE (arg0) == RDIV_EXPR)
10489 return fold_build2 (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
10490 fold_build2 (MULT_EXPR, type,
10491 TREE_OPERAND (arg0, 1), arg1));
10493 /* Convert A/(B/C) to (A/B)*C. */
10494 if (flag_unsafe_math_optimizations
10495 && TREE_CODE (arg1) == RDIV_EXPR)
10496 return fold_build2 (MULT_EXPR, type,
10497 fold_build2 (RDIV_EXPR, type, arg0,
10498 TREE_OPERAND (arg1, 0)),
10499 TREE_OPERAND (arg1, 1));
10501 /* Convert C1/(X*C2) into (C1/C2)/X. */
10502 if (flag_unsafe_math_optimizations
10503 && TREE_CODE (arg1) == MULT_EXPR
10504 && TREE_CODE (arg0) == REAL_CST
10505 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
10507 tree tem = const_binop (RDIV_EXPR, arg0,
10508 TREE_OPERAND (arg1, 1), 0);
10510 return fold_build2 (RDIV_EXPR, type, tem,
10511 TREE_OPERAND (arg1, 0));
10514 if (flag_unsafe_math_optimizations)
10516 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
10517 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
10519 /* Optimize sin(x)/cos(x) as tan(x). */
10520 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_COS)
10521 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_COSF)
10522 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_COSL))
10523 && operand_equal_p (CALL_EXPR_ARG (arg0, 0),
10524 CALL_EXPR_ARG (arg1, 0), 0))
10526 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
10528 if (tanfn != NULL_TREE)
10529 return build_call_expr (tanfn, 1, CALL_EXPR_ARG (arg0, 0));
10532 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
10533 if (((fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_SIN)
10534 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_SINF)
10535 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_SINL))
10536 && operand_equal_p (CALL_EXPR_ARG (arg0, 0),
10537 CALL_EXPR_ARG (arg1, 0), 0))
10539 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
10541 if (tanfn != NULL_TREE)
10543 tree tmp = build_call_expr (tanfn, 1, CALL_EXPR_ARG (arg0, 0));
10544 return fold_build2 (RDIV_EXPR, type,
10545 build_real (type, dconst1), tmp);
10549 /* Optimize sin(x)/tan(x) as cos(x) if we don't care about
10550 NaNs or Infinities. */
10551 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_TAN)
10552 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_TANF)
10553 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_TANL)))
10555 tree arg00 = CALL_EXPR_ARG (arg0, 0);
10556 tree arg01 = CALL_EXPR_ARG (arg1, 0);
10558 if (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg00)))
10559 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg00)))
10560 && operand_equal_p (arg00, arg01, 0))
10562 tree cosfn = mathfn_built_in (type, BUILT_IN_COS);
10564 if (cosfn != NULL_TREE)
10565 return build_call_expr (cosfn, 1, arg00);
10569 /* Optimize tan(x)/sin(x) as 1.0/cos(x) if we don't care about
10570 NaNs or Infinities. */
10571 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_SIN)
10572 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_SINF)
10573 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_SINL)))
10575 tree arg00 = CALL_EXPR_ARG (arg0, 0);
10576 tree arg01 = CALL_EXPR_ARG (arg1, 0);
10578 if (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg00)))
10579 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg00)))
10580 && operand_equal_p (arg00, arg01, 0))
10582 tree cosfn = mathfn_built_in (type, BUILT_IN_COS);
10584 if (cosfn != NULL_TREE)
10586 tree tmp = build_call_expr (cosfn, 1, arg00);
10587 return fold_build2 (RDIV_EXPR, type,
10588 build_real (type, dconst1),
10594 /* Optimize pow(x,c)/x as pow(x,c-1). */
10595 if (fcode0 == BUILT_IN_POW
10596 || fcode0 == BUILT_IN_POWF
10597 || fcode0 == BUILT_IN_POWL)
10599 tree arg00 = CALL_EXPR_ARG (arg0, 0);
10600 tree arg01 = CALL_EXPR_ARG (arg0, 1);
10601 if (TREE_CODE (arg01) == REAL_CST
10602 && !TREE_OVERFLOW (arg01)
10603 && operand_equal_p (arg1, arg00, 0))
10605 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10609 c = TREE_REAL_CST (arg01);
10610 real_arithmetic (&c, MINUS_EXPR, &c, &dconst1);
10611 arg = build_real (type, c);
10612 return build_call_expr (powfn, 2, arg1, arg);
10616 /* Optimize x/expN(y) into x*expN(-y). */
10617 if (BUILTIN_EXPONENT_P (fcode1))
10619 tree expfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
10620 tree arg = negate_expr (CALL_EXPR_ARG (arg1, 0));
10621 arg1 = build_call_expr (expfn, 1, fold_convert (type, arg));
10622 return fold_build2 (MULT_EXPR, type, arg0, arg1);
10625 /* Optimize x/pow(y,z) into x*pow(y,-z). */
10626 if (fcode1 == BUILT_IN_POW
10627 || fcode1 == BUILT_IN_POWF
10628 || fcode1 == BUILT_IN_POWL)
10630 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
10631 tree arg10 = CALL_EXPR_ARG (arg1, 0);
10632 tree arg11 = CALL_EXPR_ARG (arg1, 1);
10633 tree neg11 = fold_convert (type, negate_expr (arg11));
10634 arg1 = build_call_expr (powfn, 2, arg10, neg11);
10635 return fold_build2 (MULT_EXPR, type, arg0, arg1);
10640 case TRUNC_DIV_EXPR:
10641 case FLOOR_DIV_EXPR:
10642 /* Simplify A / (B << N) where A and B are positive and B is
10643 a power of 2, to A >> (N + log2(B)). */
10644 strict_overflow_p = false;
10645 if (TREE_CODE (arg1) == LSHIFT_EXPR
10646 && (TYPE_UNSIGNED (type)
10647 || tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p)))
10649 tree sval = TREE_OPERAND (arg1, 0);
10650 if (integer_pow2p (sval) && tree_int_cst_sgn (sval) > 0)
10652 tree sh_cnt = TREE_OPERAND (arg1, 1);
10653 unsigned long pow2 = exact_log2 (TREE_INT_CST_LOW (sval));
10655 if (strict_overflow_p)
10656 fold_overflow_warning (("assuming signed overflow does not "
10657 "occur when simplifying A / (B << N)"),
10658 WARN_STRICT_OVERFLOW_MISC);
10660 sh_cnt = fold_build2 (PLUS_EXPR, TREE_TYPE (sh_cnt),
10661 sh_cnt, build_int_cst (NULL_TREE, pow2));
10662 return fold_build2 (RSHIFT_EXPR, type,
10663 fold_convert (type, arg0), sh_cnt);
10668 case ROUND_DIV_EXPR:
10669 case CEIL_DIV_EXPR:
10670 case EXACT_DIV_EXPR:
10671 if (integer_onep (arg1))
10672 return non_lvalue (fold_convert (type, arg0));
10673 if (integer_zerop (arg1))
10675 /* X / -1 is -X. */
10676 if (!TYPE_UNSIGNED (type)
10677 && TREE_CODE (arg1) == INTEGER_CST
10678 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
10679 && TREE_INT_CST_HIGH (arg1) == -1)
10680 return fold_convert (type, negate_expr (arg0));
10682 /* Convert -A / -B to A / B when the type is signed and overflow is
10684 if ((!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
10685 && TREE_CODE (arg0) == NEGATE_EXPR
10686 && negate_expr_p (arg1))
10688 if (INTEGRAL_TYPE_P (type))
10689 fold_overflow_warning (("assuming signed overflow does not occur "
10690 "when distributing negation across "
10692 WARN_STRICT_OVERFLOW_MISC);
10693 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
10694 negate_expr (arg1));
10696 if ((!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
10697 && TREE_CODE (arg1) == NEGATE_EXPR
10698 && negate_expr_p (arg0))
10700 if (INTEGRAL_TYPE_P (type))
10701 fold_overflow_warning (("assuming signed overflow does not occur "
10702 "when distributing negation across "
10704 WARN_STRICT_OVERFLOW_MISC);
10705 return fold_build2 (code, type, negate_expr (arg0),
10706 TREE_OPERAND (arg1, 0));
10709 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
10710 operation, EXACT_DIV_EXPR.
10712 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
10713 At one time others generated faster code, it's not clear if they do
10714 after the last round to changes to the DIV code in expmed.c. */
10715 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
10716 && multiple_of_p (type, arg0, arg1))
10717 return fold_build2 (EXACT_DIV_EXPR, type, arg0, arg1);
10719 strict_overflow_p = false;
10720 if (TREE_CODE (arg1) == INTEGER_CST
10721 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
10722 &strict_overflow_p)))
10724 if (strict_overflow_p)
10725 fold_overflow_warning (("assuming signed overflow does not occur "
10726 "when simplifying division"),
10727 WARN_STRICT_OVERFLOW_MISC);
10728 return fold_convert (type, tem);
10733 case CEIL_MOD_EXPR:
10734 case FLOOR_MOD_EXPR:
10735 case ROUND_MOD_EXPR:
10736 case TRUNC_MOD_EXPR:
10737 /* X % 1 is always zero, but be sure to preserve any side
10739 if (integer_onep (arg1))
10740 return omit_one_operand (type, integer_zero_node, arg0);
10742 /* X % 0, return X % 0 unchanged so that we can get the
10743 proper warnings and errors. */
10744 if (integer_zerop (arg1))
10747 /* 0 % X is always zero, but be sure to preserve any side
10748 effects in X. Place this after checking for X == 0. */
10749 if (integer_zerop (arg0))
10750 return omit_one_operand (type, integer_zero_node, arg1);
10752 /* X % -1 is zero. */
10753 if (!TYPE_UNSIGNED (type)
10754 && TREE_CODE (arg1) == INTEGER_CST
10755 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
10756 && TREE_INT_CST_HIGH (arg1) == -1)
10757 return omit_one_operand (type, integer_zero_node, arg0);
10759 /* Optimize TRUNC_MOD_EXPR by a power of two into a BIT_AND_EXPR,
10760 i.e. "X % C" into "X & (C - 1)", if X and C are positive. */
10761 strict_overflow_p = false;
10762 if ((code == TRUNC_MOD_EXPR || code == FLOOR_MOD_EXPR)
10763 && (TYPE_UNSIGNED (type)
10764 || tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p)))
10767 /* Also optimize A % (C << N) where C is a power of 2,
10768 to A & ((C << N) - 1). */
10769 if (TREE_CODE (arg1) == LSHIFT_EXPR)
10770 c = TREE_OPERAND (arg1, 0);
10772 if (integer_pow2p (c) && tree_int_cst_sgn (c) > 0)
10774 tree mask = fold_build2 (MINUS_EXPR, TREE_TYPE (arg1), arg1,
10775 build_int_cst (TREE_TYPE (arg1), 1));
10776 if (strict_overflow_p)
10777 fold_overflow_warning (("assuming signed overflow does not "
10778 "occur when simplifying "
10779 "X % (power of two)"),
10780 WARN_STRICT_OVERFLOW_MISC);
10781 return fold_build2 (BIT_AND_EXPR, type,
10782 fold_convert (type, arg0),
10783 fold_convert (type, mask));
10787 /* X % -C is the same as X % C. */
10788 if (code == TRUNC_MOD_EXPR
10789 && !TYPE_UNSIGNED (type)
10790 && TREE_CODE (arg1) == INTEGER_CST
10791 && !TREE_OVERFLOW (arg1)
10792 && TREE_INT_CST_HIGH (arg1) < 0
10793 && !TYPE_OVERFLOW_TRAPS (type)
10794 /* Avoid this transformation if C is INT_MIN, i.e. C == -C. */
10795 && !sign_bit_p (arg1, arg1))
10796 return fold_build2 (code, type, fold_convert (type, arg0),
10797 fold_convert (type, negate_expr (arg1)));
10799 /* X % -Y is the same as X % Y. */
10800 if (code == TRUNC_MOD_EXPR
10801 && !TYPE_UNSIGNED (type)
10802 && TREE_CODE (arg1) == NEGATE_EXPR
10803 && !TYPE_OVERFLOW_TRAPS (type))
10804 return fold_build2 (code, type, fold_convert (type, arg0),
10805 fold_convert (type, TREE_OPERAND (arg1, 0)));
10807 if (TREE_CODE (arg1) == INTEGER_CST
10808 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
10809 &strict_overflow_p)))
10811 if (strict_overflow_p)
10812 fold_overflow_warning (("assuming signed overflow does not occur "
10813 "when simplifying modulos"),
10814 WARN_STRICT_OVERFLOW_MISC);
10815 return fold_convert (type, tem);
10822 if (integer_all_onesp (arg0))
10823 return omit_one_operand (type, arg0, arg1);
10827 /* Optimize -1 >> x for arithmetic right shifts. */
10828 if (integer_all_onesp (arg0) && !TYPE_UNSIGNED (type))
10829 return omit_one_operand (type, arg0, arg1);
10830 /* ... fall through ... */
10834 if (integer_zerop (arg1))
10835 return non_lvalue (fold_convert (type, arg0));
10836 if (integer_zerop (arg0))
10837 return omit_one_operand (type, arg0, arg1);
10839 /* Since negative shift count is not well-defined,
10840 don't try to compute it in the compiler. */
10841 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
10844 /* Turn (a OP c1) OP c2 into a OP (c1+c2). */
10845 if (TREE_CODE (op0) == code && host_integerp (arg1, false)
10846 && TREE_INT_CST_LOW (arg1) < TYPE_PRECISION (type)
10847 && host_integerp (TREE_OPERAND (arg0, 1), false)
10848 && TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) < TYPE_PRECISION (type))
10850 HOST_WIDE_INT low = (TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1))
10851 + TREE_INT_CST_LOW (arg1));
10853 /* Deal with a OP (c1 + c2) being undefined but (a OP c1) OP c2
10854 being well defined. */
10855 if (low >= TYPE_PRECISION (type))
10857 if (code == LROTATE_EXPR || code == RROTATE_EXPR)
10858 low = low % TYPE_PRECISION (type);
10859 else if (TYPE_UNSIGNED (type) || code == LSHIFT_EXPR)
10860 return build_int_cst (type, 0);
10862 low = TYPE_PRECISION (type) - 1;
10865 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
10866 build_int_cst (type, low));
10869 /* Transform (x >> c) << c into x & (-1<<c), or transform (x << c) >> c
10870 into x & ((unsigned)-1 >> c) for unsigned types. */
10871 if (((code == LSHIFT_EXPR && TREE_CODE (arg0) == RSHIFT_EXPR)
10872 || (TYPE_UNSIGNED (type)
10873 && code == RSHIFT_EXPR && TREE_CODE (arg0) == LSHIFT_EXPR))
10874 && host_integerp (arg1, false)
10875 && TREE_INT_CST_LOW (arg1) < TYPE_PRECISION (type)
10876 && host_integerp (TREE_OPERAND (arg0, 1), false)
10877 && TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) < TYPE_PRECISION (type))
10879 HOST_WIDE_INT low0 = TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1));
10880 HOST_WIDE_INT low1 = TREE_INT_CST_LOW (arg1);
10886 arg00 = fold_convert (type, TREE_OPERAND (arg0, 0));
10888 lshift = build_int_cst (type, -1);
10889 lshift = int_const_binop (code, lshift, arg1, 0);
10891 return fold_build2 (BIT_AND_EXPR, type, arg00, lshift);
10895 /* Rewrite an LROTATE_EXPR by a constant into an
10896 RROTATE_EXPR by a new constant. */
10897 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
10899 tree tem = build_int_cst (TREE_TYPE (arg1),
10900 GET_MODE_BITSIZE (TYPE_MODE (type)));
10901 tem = const_binop (MINUS_EXPR, tem, arg1, 0);
10902 return fold_build2 (RROTATE_EXPR, type, arg0, tem);
10905 /* If we have a rotate of a bit operation with the rotate count and
10906 the second operand of the bit operation both constant,
10907 permute the two operations. */
10908 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
10909 && (TREE_CODE (arg0) == BIT_AND_EXPR
10910 || TREE_CODE (arg0) == BIT_IOR_EXPR
10911 || TREE_CODE (arg0) == BIT_XOR_EXPR)
10912 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
10913 return fold_build2 (TREE_CODE (arg0), type,
10914 fold_build2 (code, type,
10915 TREE_OPERAND (arg0, 0), arg1),
10916 fold_build2 (code, type,
10917 TREE_OPERAND (arg0, 1), arg1));
10919 /* Two consecutive rotates adding up to the width of the mode can
10921 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
10922 && TREE_CODE (arg0) == RROTATE_EXPR
10923 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
10924 && TREE_INT_CST_HIGH (arg1) == 0
10925 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
10926 && ((TREE_INT_CST_LOW (arg1)
10927 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
10928 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type))))
10929 return TREE_OPERAND (arg0, 0);
10934 if (operand_equal_p (arg0, arg1, 0))
10935 return omit_one_operand (type, arg0, arg1);
10936 if (INTEGRAL_TYPE_P (type)
10937 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
10938 return omit_one_operand (type, arg1, arg0);
10939 tem = fold_minmax (MIN_EXPR, type, arg0, arg1);
10945 if (operand_equal_p (arg0, arg1, 0))
10946 return omit_one_operand (type, arg0, arg1);
10947 if (INTEGRAL_TYPE_P (type)
10948 && TYPE_MAX_VALUE (type)
10949 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
10950 return omit_one_operand (type, arg1, arg0);
10951 tem = fold_minmax (MAX_EXPR, type, arg0, arg1);
10956 case TRUTH_ANDIF_EXPR:
10957 /* Note that the operands of this must be ints
10958 and their values must be 0 or 1.
10959 ("true" is a fixed value perhaps depending on the language.) */
10960 /* If first arg is constant zero, return it. */
10961 if (integer_zerop (arg0))
10962 return fold_convert (type, arg0);
10963 case TRUTH_AND_EXPR:
10964 /* If either arg is constant true, drop it. */
10965 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
10966 return non_lvalue (fold_convert (type, arg1));
10967 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
10968 /* Preserve sequence points. */
10969 && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
10970 return non_lvalue (fold_convert (type, arg0));
10971 /* If second arg is constant zero, result is zero, but first arg
10972 must be evaluated. */
10973 if (integer_zerop (arg1))
10974 return omit_one_operand (type, arg1, arg0);
10975 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
10976 case will be handled here. */
10977 if (integer_zerop (arg0))
10978 return omit_one_operand (type, arg0, arg1);
10980 /* !X && X is always false. */
10981 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
10982 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10983 return omit_one_operand (type, integer_zero_node, arg1);
10984 /* X && !X is always false. */
10985 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
10986 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10987 return omit_one_operand (type, integer_zero_node, arg0);
10989 /* A < X && A + 1 > Y ==> A < X && A >= Y. Normally A + 1 > Y
10990 means A >= Y && A != MAX, but in this case we know that
10993 if (!TREE_SIDE_EFFECTS (arg0)
10994 && !TREE_SIDE_EFFECTS (arg1))
10996 tem = fold_to_nonsharp_ineq_using_bound (arg0, arg1);
10997 if (tem && !operand_equal_p (tem, arg0, 0))
10998 return fold_build2 (code, type, tem, arg1);
11000 tem = fold_to_nonsharp_ineq_using_bound (arg1, arg0);
11001 if (tem && !operand_equal_p (tem, arg1, 0))
11002 return fold_build2 (code, type, arg0, tem);
11006 /* We only do these simplifications if we are optimizing. */
11010 /* Check for things like (A || B) && (A || C). We can convert this
11011 to A || (B && C). Note that either operator can be any of the four
11012 truth and/or operations and the transformation will still be
11013 valid. Also note that we only care about order for the
11014 ANDIF and ORIF operators. If B contains side effects, this
11015 might change the truth-value of A. */
11016 if (TREE_CODE (arg0) == TREE_CODE (arg1)
11017 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
11018 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
11019 || TREE_CODE (arg0) == TRUTH_AND_EXPR
11020 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
11021 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
11023 tree a00 = TREE_OPERAND (arg0, 0);
11024 tree a01 = TREE_OPERAND (arg0, 1);
11025 tree a10 = TREE_OPERAND (arg1, 0);
11026 tree a11 = TREE_OPERAND (arg1, 1);
11027 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
11028 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
11029 && (code == TRUTH_AND_EXPR
11030 || code == TRUTH_OR_EXPR));
11032 if (operand_equal_p (a00, a10, 0))
11033 return fold_build2 (TREE_CODE (arg0), type, a00,
11034 fold_build2 (code, type, a01, a11));
11035 else if (commutative && operand_equal_p (a00, a11, 0))
11036 return fold_build2 (TREE_CODE (arg0), type, a00,
11037 fold_build2 (code, type, a01, a10));
11038 else if (commutative && operand_equal_p (a01, a10, 0))
11039 return fold_build2 (TREE_CODE (arg0), type, a01,
11040 fold_build2 (code, type, a00, a11));
11042 /* This case if tricky because we must either have commutative
11043 operators or else A10 must not have side-effects. */
11045 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
11046 && operand_equal_p (a01, a11, 0))
11047 return fold_build2 (TREE_CODE (arg0), type,
11048 fold_build2 (code, type, a00, a10),
11052 /* See if we can build a range comparison. */
11053 if (0 != (tem = fold_range_test (code, type, op0, op1)))
11056 /* Check for the possibility of merging component references. If our
11057 lhs is another similar operation, try to merge its rhs with our
11058 rhs. Then try to merge our lhs and rhs. */
11059 if (TREE_CODE (arg0) == code
11060 && 0 != (tem = fold_truthop (code, type,
11061 TREE_OPERAND (arg0, 1), arg1)))
11062 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
11064 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
11069 case TRUTH_ORIF_EXPR:
11070 /* Note that the operands of this must be ints
11071 and their values must be 0 or true.
11072 ("true" is a fixed value perhaps depending on the language.) */
11073 /* If first arg is constant true, return it. */
11074 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
11075 return fold_convert (type, arg0);
11076 case TRUTH_OR_EXPR:
11077 /* If either arg is constant zero, drop it. */
11078 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
11079 return non_lvalue (fold_convert (type, arg1));
11080 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
11081 /* Preserve sequence points. */
11082 && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
11083 return non_lvalue (fold_convert (type, arg0));
11084 /* If second arg is constant true, result is true, but we must
11085 evaluate first arg. */
11086 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
11087 return omit_one_operand (type, arg1, arg0);
11088 /* Likewise for first arg, but note this only occurs here for
11090 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
11091 return omit_one_operand (type, arg0, arg1);
11093 /* !X || X is always true. */
11094 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
11095 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
11096 return omit_one_operand (type, integer_one_node, arg1);
11097 /* X || !X is always true. */
11098 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
11099 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
11100 return omit_one_operand (type, integer_one_node, arg0);
11104 case TRUTH_XOR_EXPR:
11105 /* If the second arg is constant zero, drop it. */
11106 if (integer_zerop (arg1))
11107 return non_lvalue (fold_convert (type, arg0));
11108 /* If the second arg is constant true, this is a logical inversion. */
11109 if (integer_onep (arg1))
11111 /* Only call invert_truthvalue if operand is a truth value. */
11112 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
11113 tem = fold_build1 (TRUTH_NOT_EXPR, TREE_TYPE (arg0), arg0);
11115 tem = invert_truthvalue (arg0);
11116 return non_lvalue (fold_convert (type, tem));
11118 /* Identical arguments cancel to zero. */
11119 if (operand_equal_p (arg0, arg1, 0))
11120 return omit_one_operand (type, integer_zero_node, arg0);
11122 /* !X ^ X is always true. */
11123 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
11124 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
11125 return omit_one_operand (type, integer_one_node, arg1);
11127 /* X ^ !X is always true. */
11128 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
11129 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
11130 return omit_one_operand (type, integer_one_node, arg0);
11136 tem = fold_comparison (code, type, op0, op1);
11137 if (tem != NULL_TREE)
11140 /* bool_var != 0 becomes bool_var. */
11141 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_zerop (arg1)
11142 && code == NE_EXPR)
11143 return non_lvalue (fold_convert (type, arg0));
11145 /* bool_var == 1 becomes bool_var. */
11146 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_onep (arg1)
11147 && code == EQ_EXPR)
11148 return non_lvalue (fold_convert (type, arg0));
11150 /* bool_var != 1 becomes !bool_var. */
11151 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_onep (arg1)
11152 && code == NE_EXPR)
11153 return fold_build1 (TRUTH_NOT_EXPR, type, arg0);
11155 /* bool_var == 0 becomes !bool_var. */
11156 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_zerop (arg1)
11157 && code == EQ_EXPR)
11158 return fold_build1 (TRUTH_NOT_EXPR, type, arg0);
11160 /* If this is an equality comparison of the address of two non-weak,
11161 unaliased symbols neither of which are extern (since we do not
11162 have access to attributes for externs), then we know the result. */
11163 if (TREE_CODE (arg0) == ADDR_EXPR
11164 && VAR_OR_FUNCTION_DECL_P (TREE_OPERAND (arg0, 0))
11165 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
11166 && ! lookup_attribute ("alias",
11167 DECL_ATTRIBUTES (TREE_OPERAND (arg0, 0)))
11168 && ! DECL_EXTERNAL (TREE_OPERAND (arg0, 0))
11169 && TREE_CODE (arg1) == ADDR_EXPR
11170 && VAR_OR_FUNCTION_DECL_P (TREE_OPERAND (arg1, 0))
11171 && ! DECL_WEAK (TREE_OPERAND (arg1, 0))
11172 && ! lookup_attribute ("alias",
11173 DECL_ATTRIBUTES (TREE_OPERAND (arg1, 0)))
11174 && ! DECL_EXTERNAL (TREE_OPERAND (arg1, 0)))
11176 /* We know that we're looking at the address of two
11177 non-weak, unaliased, static _DECL nodes.
11179 It is both wasteful and incorrect to call operand_equal_p
11180 to compare the two ADDR_EXPR nodes. It is wasteful in that
11181 all we need to do is test pointer equality for the arguments
11182 to the two ADDR_EXPR nodes. It is incorrect to use
11183 operand_equal_p as that function is NOT equivalent to a
11184 C equality test. It can in fact return false for two
11185 objects which would test as equal using the C equality
11187 bool equal = TREE_OPERAND (arg0, 0) == TREE_OPERAND (arg1, 0);
11188 return constant_boolean_node (equal
11189 ? code == EQ_EXPR : code != EQ_EXPR,
11193 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
11194 a MINUS_EXPR of a constant, we can convert it into a comparison with
11195 a revised constant as long as no overflow occurs. */
11196 if (TREE_CODE (arg1) == INTEGER_CST
11197 && (TREE_CODE (arg0) == PLUS_EXPR
11198 || TREE_CODE (arg0) == MINUS_EXPR)
11199 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
11200 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
11201 ? MINUS_EXPR : PLUS_EXPR,
11202 fold_convert (TREE_TYPE (arg0), arg1),
11203 TREE_OPERAND (arg0, 1), 0))
11204 && !TREE_OVERFLOW (tem))
11205 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
11207 /* Similarly for a NEGATE_EXPR. */
11208 if (TREE_CODE (arg0) == NEGATE_EXPR
11209 && TREE_CODE (arg1) == INTEGER_CST
11210 && 0 != (tem = negate_expr (arg1))
11211 && TREE_CODE (tem) == INTEGER_CST
11212 && !TREE_OVERFLOW (tem))
11213 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
11215 /* Similarly for a BIT_XOR_EXPR; X ^ C1 == C2 is X == (C1 ^ C2). */
11216 if (TREE_CODE (arg0) == BIT_XOR_EXPR
11217 && TREE_CODE (arg1) == INTEGER_CST
11218 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11219 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
11220 fold_build2 (BIT_XOR_EXPR, TREE_TYPE (arg0),
11221 fold_convert (TREE_TYPE (arg0), arg1),
11222 TREE_OPERAND (arg0, 1)));
11224 /* Transform comparisons of the form X +- C CMP X. */
11225 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
11226 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
11227 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
11228 && (INTEGRAL_TYPE_P (TREE_TYPE (arg0))
11229 || POINTER_TYPE_P (TREE_TYPE (arg0))))
11231 tree cst = TREE_OPERAND (arg0, 1);
11233 if (code == EQ_EXPR
11234 && !integer_zerop (cst))
11235 return omit_two_operands (type, boolean_false_node,
11236 TREE_OPERAND (arg0, 0), arg1);
11238 return omit_two_operands (type, boolean_true_node,
11239 TREE_OPERAND (arg0, 0), arg1);
11242 /* If we have X - Y == 0, we can convert that to X == Y and similarly
11243 for !=. Don't do this for ordered comparisons due to overflow. */
11244 if (TREE_CODE (arg0) == MINUS_EXPR
11245 && integer_zerop (arg1))
11246 return fold_build2 (code, type,
11247 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
11249 /* Convert ABS_EXPR<x> == 0 or ABS_EXPR<x> != 0 to x == 0 or x != 0. */
11250 if (TREE_CODE (arg0) == ABS_EXPR
11251 && (integer_zerop (arg1) || real_zerop (arg1)))
11252 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), arg1);
11254 /* If this is an EQ or NE comparison with zero and ARG0 is
11255 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
11256 two operations, but the latter can be done in one less insn
11257 on machines that have only two-operand insns or on which a
11258 constant cannot be the first operand. */
11259 if (TREE_CODE (arg0) == BIT_AND_EXPR
11260 && integer_zerop (arg1))
11262 tree arg00 = TREE_OPERAND (arg0, 0);
11263 tree arg01 = TREE_OPERAND (arg0, 1);
11264 if (TREE_CODE (arg00) == LSHIFT_EXPR
11265 && integer_onep (TREE_OPERAND (arg00, 0)))
11267 fold_build2 (code, type,
11268 build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
11269 build2 (RSHIFT_EXPR, TREE_TYPE (arg00),
11270 arg01, TREE_OPERAND (arg00, 1)),
11271 fold_convert (TREE_TYPE (arg0),
11272 integer_one_node)),
11274 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
11275 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
11277 fold_build2 (code, type,
11278 build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
11279 build2 (RSHIFT_EXPR, TREE_TYPE (arg01),
11280 arg00, TREE_OPERAND (arg01, 1)),
11281 fold_convert (TREE_TYPE (arg0),
11282 integer_one_node)),
11286 /* If this is an NE or EQ comparison of zero against the result of a
11287 signed MOD operation whose second operand is a power of 2, make
11288 the MOD operation unsigned since it is simpler and equivalent. */
11289 if (integer_zerop (arg1)
11290 && !TYPE_UNSIGNED (TREE_TYPE (arg0))
11291 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
11292 || TREE_CODE (arg0) == CEIL_MOD_EXPR
11293 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
11294 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
11295 && integer_pow2p (TREE_OPERAND (arg0, 1)))
11297 tree newtype = lang_hooks.types.unsigned_type (TREE_TYPE (arg0));
11298 tree newmod = fold_build2 (TREE_CODE (arg0), newtype,
11299 fold_convert (newtype,
11300 TREE_OPERAND (arg0, 0)),
11301 fold_convert (newtype,
11302 TREE_OPERAND (arg0, 1)));
11304 return fold_build2 (code, type, newmod,
11305 fold_convert (newtype, arg1));
11308 /* Fold ((X >> C1) & C2) == 0 and ((X >> C1) & C2) != 0 where
11309 C1 is a valid shift constant, and C2 is a power of two, i.e.
11311 if (TREE_CODE (arg0) == BIT_AND_EXPR
11312 && TREE_CODE (TREE_OPERAND (arg0, 0)) == RSHIFT_EXPR
11313 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1))
11315 && integer_pow2p (TREE_OPERAND (arg0, 1))
11316 && integer_zerop (arg1))
11318 tree itype = TREE_TYPE (arg0);
11319 unsigned HOST_WIDE_INT prec = TYPE_PRECISION (itype);
11320 tree arg001 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 1);
11322 /* Check for a valid shift count. */
11323 if (TREE_INT_CST_HIGH (arg001) == 0
11324 && TREE_INT_CST_LOW (arg001) < prec)
11326 tree arg01 = TREE_OPERAND (arg0, 1);
11327 tree arg000 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
11328 unsigned HOST_WIDE_INT log2 = tree_log2 (arg01);
11329 /* If (C2 << C1) doesn't overflow, then ((X >> C1) & C2) != 0
11330 can be rewritten as (X & (C2 << C1)) != 0. */
11331 if ((log2 + TREE_INT_CST_LOW (arg001)) < prec)
11333 tem = fold_build2 (LSHIFT_EXPR, itype, arg01, arg001);
11334 tem = fold_build2 (BIT_AND_EXPR, itype, arg000, tem);
11335 return fold_build2 (code, type, tem, arg1);
11337 /* Otherwise, for signed (arithmetic) shifts,
11338 ((X >> C1) & C2) != 0 is rewritten as X < 0, and
11339 ((X >> C1) & C2) == 0 is rewritten as X >= 0. */
11340 else if (!TYPE_UNSIGNED (itype))
11341 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR, type,
11342 arg000, build_int_cst (itype, 0));
11343 /* Otherwise, of unsigned (logical) shifts,
11344 ((X >> C1) & C2) != 0 is rewritten as (X,false), and
11345 ((X >> C1) & C2) == 0 is rewritten as (X,true). */
11347 return omit_one_operand (type,
11348 code == EQ_EXPR ? integer_one_node
11349 : integer_zero_node,
11354 /* If this is an NE comparison of zero with an AND of one, remove the
11355 comparison since the AND will give the correct value. */
11356 if (code == NE_EXPR
11357 && integer_zerop (arg1)
11358 && TREE_CODE (arg0) == BIT_AND_EXPR
11359 && integer_onep (TREE_OPERAND (arg0, 1)))
11360 return fold_convert (type, arg0);
11362 /* If we have (A & C) == C where C is a power of 2, convert this into
11363 (A & C) != 0. Similarly for NE_EXPR. */
11364 if (TREE_CODE (arg0) == BIT_AND_EXPR
11365 && integer_pow2p (TREE_OPERAND (arg0, 1))
11366 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
11367 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
11368 arg0, fold_convert (TREE_TYPE (arg0),
11369 integer_zero_node));
11371 /* If we have (A & C) != 0 or (A & C) == 0 and C is the sign
11372 bit, then fold the expression into A < 0 or A >= 0. */
11373 tem = fold_single_bit_test_into_sign_test (code, arg0, arg1, type);
11377 /* If we have (A & C) == D where D & ~C != 0, convert this into 0.
11378 Similarly for NE_EXPR. */
11379 if (TREE_CODE (arg0) == BIT_AND_EXPR
11380 && TREE_CODE (arg1) == INTEGER_CST
11381 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11383 tree notc = fold_build1 (BIT_NOT_EXPR,
11384 TREE_TYPE (TREE_OPERAND (arg0, 1)),
11385 TREE_OPERAND (arg0, 1));
11386 tree dandnotc = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
11388 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
11389 if (integer_nonzerop (dandnotc))
11390 return omit_one_operand (type, rslt, arg0);
11393 /* If we have (A | C) == D where C & ~D != 0, convert this into 0.
11394 Similarly for NE_EXPR. */
11395 if (TREE_CODE (arg0) == BIT_IOR_EXPR
11396 && TREE_CODE (arg1) == INTEGER_CST
11397 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11399 tree notd = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1), arg1);
11400 tree candnotd = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
11401 TREE_OPERAND (arg0, 1), notd);
11402 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
11403 if (integer_nonzerop (candnotd))
11404 return omit_one_operand (type, rslt, arg0);
11407 /* If this is a comparison of a field, we may be able to simplify it. */
11408 if ((TREE_CODE (arg0) == COMPONENT_REF
11409 || TREE_CODE (arg0) == BIT_FIELD_REF)
11410 /* Handle the constant case even without -O
11411 to make sure the warnings are given. */
11412 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
11414 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
11419 /* Optimize comparisons of strlen vs zero to a compare of the
11420 first character of the string vs zero. To wit,
11421 strlen(ptr) == 0 => *ptr == 0
11422 strlen(ptr) != 0 => *ptr != 0
11423 Other cases should reduce to one of these two (or a constant)
11424 due to the return value of strlen being unsigned. */
11425 if (TREE_CODE (arg0) == CALL_EXPR
11426 && integer_zerop (arg1))
11428 tree fndecl = get_callee_fndecl (arg0);
11431 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
11432 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
11433 && call_expr_nargs (arg0) == 1
11434 && TREE_CODE (TREE_TYPE (CALL_EXPR_ARG (arg0, 0))) == POINTER_TYPE)
11436 tree iref = build_fold_indirect_ref (CALL_EXPR_ARG (arg0, 0));
11437 return fold_build2 (code, type, iref,
11438 build_int_cst (TREE_TYPE (iref), 0));
11442 /* Fold (X >> C) != 0 into X < 0 if C is one less than the width
11443 of X. Similarly fold (X >> C) == 0 into X >= 0. */
11444 if (TREE_CODE (arg0) == RSHIFT_EXPR
11445 && integer_zerop (arg1)
11446 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11448 tree arg00 = TREE_OPERAND (arg0, 0);
11449 tree arg01 = TREE_OPERAND (arg0, 1);
11450 tree itype = TREE_TYPE (arg00);
11451 if (TREE_INT_CST_HIGH (arg01) == 0
11452 && TREE_INT_CST_LOW (arg01)
11453 == (unsigned HOST_WIDE_INT) (TYPE_PRECISION (itype) - 1))
11455 if (TYPE_UNSIGNED (itype))
11457 itype = lang_hooks.types.signed_type (itype);
11458 arg00 = fold_convert (itype, arg00);
11460 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
11461 type, arg00, build_int_cst (itype, 0));
11465 /* (X ^ Y) == 0 becomes X == Y, and (X ^ Y) != 0 becomes X != Y. */
11466 if (integer_zerop (arg1)
11467 && TREE_CODE (arg0) == BIT_XOR_EXPR)
11468 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
11469 TREE_OPERAND (arg0, 1));
11471 /* (X ^ Y) == Y becomes X == 0. We know that Y has no side-effects. */
11472 if (TREE_CODE (arg0) == BIT_XOR_EXPR
11473 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
11474 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
11475 build_int_cst (TREE_TYPE (arg1), 0));
11476 /* Likewise (X ^ Y) == X becomes Y == 0. X has no side-effects. */
11477 if (TREE_CODE (arg0) == BIT_XOR_EXPR
11478 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
11479 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
11480 return fold_build2 (code, type, TREE_OPERAND (arg0, 1),
11481 build_int_cst (TREE_TYPE (arg1), 0));
11483 /* (X ^ C1) op C2 can be rewritten as X op (C1 ^ C2). */
11484 if (TREE_CODE (arg0) == BIT_XOR_EXPR
11485 && TREE_CODE (arg1) == INTEGER_CST
11486 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11487 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
11488 fold_build2 (BIT_XOR_EXPR, TREE_TYPE (arg1),
11489 TREE_OPERAND (arg0, 1), arg1));
11491 /* Fold (~X & C) == 0 into (X & C) != 0 and (~X & C) != 0 into
11492 (X & C) == 0 when C is a single bit. */
11493 if (TREE_CODE (arg0) == BIT_AND_EXPR
11494 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_NOT_EXPR
11495 && integer_zerop (arg1)
11496 && integer_pow2p (TREE_OPERAND (arg0, 1)))
11498 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
11499 TREE_OPERAND (TREE_OPERAND (arg0, 0), 0),
11500 TREE_OPERAND (arg0, 1));
11501 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR,
11505 /* Fold ((X & C) ^ C) eq/ne 0 into (X & C) ne/eq 0, when the
11506 constant C is a power of two, i.e. a single bit. */
11507 if (TREE_CODE (arg0) == BIT_XOR_EXPR
11508 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
11509 && integer_zerop (arg1)
11510 && integer_pow2p (TREE_OPERAND (arg0, 1))
11511 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
11512 TREE_OPERAND (arg0, 1), OEP_ONLY_CONST))
11514 tree arg00 = TREE_OPERAND (arg0, 0);
11515 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
11516 arg00, build_int_cst (TREE_TYPE (arg00), 0));
11519 /* Likewise, fold ((X ^ C) & C) eq/ne 0 into (X & C) ne/eq 0,
11520 when is C is a power of two, i.e. a single bit. */
11521 if (TREE_CODE (arg0) == BIT_AND_EXPR
11522 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_XOR_EXPR
11523 && integer_zerop (arg1)
11524 && integer_pow2p (TREE_OPERAND (arg0, 1))
11525 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
11526 TREE_OPERAND (arg0, 1), OEP_ONLY_CONST))
11528 tree arg000 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
11529 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg000),
11530 arg000, TREE_OPERAND (arg0, 1));
11531 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
11532 tem, build_int_cst (TREE_TYPE (tem), 0));
11535 if (integer_zerop (arg1)
11536 && tree_expr_nonzero_p (arg0))
11538 tree res = constant_boolean_node (code==NE_EXPR, type);
11539 return omit_one_operand (type, res, arg0);
11542 /* Fold -X op -Y as X op Y, where op is eq/ne. */
11543 if (TREE_CODE (arg0) == NEGATE_EXPR
11544 && TREE_CODE (arg1) == NEGATE_EXPR)
11545 return fold_build2 (code, type,
11546 TREE_OPERAND (arg0, 0),
11547 TREE_OPERAND (arg1, 0));
11549 /* Fold (X & C) op (Y & C) as (X ^ Y) & C op 0", and symmetries. */
11550 if (TREE_CODE (arg0) == BIT_AND_EXPR
11551 && TREE_CODE (arg1) == BIT_AND_EXPR)
11553 tree arg00 = TREE_OPERAND (arg0, 0);
11554 tree arg01 = TREE_OPERAND (arg0, 1);
11555 tree arg10 = TREE_OPERAND (arg1, 0);
11556 tree arg11 = TREE_OPERAND (arg1, 1);
11557 tree itype = TREE_TYPE (arg0);
11559 if (operand_equal_p (arg01, arg11, 0))
11560 return fold_build2 (code, type,
11561 fold_build2 (BIT_AND_EXPR, itype,
11562 fold_build2 (BIT_XOR_EXPR, itype,
11565 build_int_cst (itype, 0));
11567 if (operand_equal_p (arg01, arg10, 0))
11568 return fold_build2 (code, type,
11569 fold_build2 (BIT_AND_EXPR, itype,
11570 fold_build2 (BIT_XOR_EXPR, itype,
11573 build_int_cst (itype, 0));
11575 if (operand_equal_p (arg00, arg11, 0))
11576 return fold_build2 (code, type,
11577 fold_build2 (BIT_AND_EXPR, itype,
11578 fold_build2 (BIT_XOR_EXPR, itype,
11581 build_int_cst (itype, 0));
11583 if (operand_equal_p (arg00, arg10, 0))
11584 return fold_build2 (code, type,
11585 fold_build2 (BIT_AND_EXPR, itype,
11586 fold_build2 (BIT_XOR_EXPR, itype,
11589 build_int_cst (itype, 0));
11592 if (TREE_CODE (arg0) == BIT_XOR_EXPR
11593 && TREE_CODE (arg1) == BIT_XOR_EXPR)
11595 tree arg00 = TREE_OPERAND (arg0, 0);
11596 tree arg01 = TREE_OPERAND (arg0, 1);
11597 tree arg10 = TREE_OPERAND (arg1, 0);
11598 tree arg11 = TREE_OPERAND (arg1, 1);
11599 tree itype = TREE_TYPE (arg0);
11601 /* Optimize (X ^ Z) op (Y ^ Z) as X op Y, and symmetries.
11602 operand_equal_p guarantees no side-effects so we don't need
11603 to use omit_one_operand on Z. */
11604 if (operand_equal_p (arg01, arg11, 0))
11605 return fold_build2 (code, type, arg00, arg10);
11606 if (operand_equal_p (arg01, arg10, 0))
11607 return fold_build2 (code, type, arg00, arg11);
11608 if (operand_equal_p (arg00, arg11, 0))
11609 return fold_build2 (code, type, arg01, arg10);
11610 if (operand_equal_p (arg00, arg10, 0))
11611 return fold_build2 (code, type, arg01, arg11);
11613 /* Optimize (X ^ C1) op (Y ^ C2) as (X ^ (C1 ^ C2)) op Y. */
11614 if (TREE_CODE (arg01) == INTEGER_CST
11615 && TREE_CODE (arg11) == INTEGER_CST)
11616 return fold_build2 (code, type,
11617 fold_build2 (BIT_XOR_EXPR, itype, arg00,
11618 fold_build2 (BIT_XOR_EXPR, itype,
11623 /* Attempt to simplify equality/inequality comparisons of complex
11624 values. Only lower the comparison if the result is known or
11625 can be simplified to a single scalar comparison. */
11626 if ((TREE_CODE (arg0) == COMPLEX_EXPR
11627 || TREE_CODE (arg0) == COMPLEX_CST)
11628 && (TREE_CODE (arg1) == COMPLEX_EXPR
11629 || TREE_CODE (arg1) == COMPLEX_CST))
11631 tree real0, imag0, real1, imag1;
11634 if (TREE_CODE (arg0) == COMPLEX_EXPR)
11636 real0 = TREE_OPERAND (arg0, 0);
11637 imag0 = TREE_OPERAND (arg0, 1);
11641 real0 = TREE_REALPART (arg0);
11642 imag0 = TREE_IMAGPART (arg0);
11645 if (TREE_CODE (arg1) == COMPLEX_EXPR)
11647 real1 = TREE_OPERAND (arg1, 0);
11648 imag1 = TREE_OPERAND (arg1, 1);
11652 real1 = TREE_REALPART (arg1);
11653 imag1 = TREE_IMAGPART (arg1);
11656 rcond = fold_binary (code, type, real0, real1);
11657 if (rcond && TREE_CODE (rcond) == INTEGER_CST)
11659 if (integer_zerop (rcond))
11661 if (code == EQ_EXPR)
11662 return omit_two_operands (type, boolean_false_node,
11664 return fold_build2 (NE_EXPR, type, imag0, imag1);
11668 if (code == NE_EXPR)
11669 return omit_two_operands (type, boolean_true_node,
11671 return fold_build2 (EQ_EXPR, type, imag0, imag1);
11675 icond = fold_binary (code, type, imag0, imag1);
11676 if (icond && TREE_CODE (icond) == INTEGER_CST)
11678 if (integer_zerop (icond))
11680 if (code == EQ_EXPR)
11681 return omit_two_operands (type, boolean_false_node,
11683 return fold_build2 (NE_EXPR, type, real0, real1);
11687 if (code == NE_EXPR)
11688 return omit_two_operands (type, boolean_true_node,
11690 return fold_build2 (EQ_EXPR, type, real0, real1);
11701 tem = fold_comparison (code, type, op0, op1);
11702 if (tem != NULL_TREE)
11705 /* Transform comparisons of the form X +- C CMP X. */
11706 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
11707 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
11708 && ((TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
11709 && !HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0))))
11710 || (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
11711 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))))
11713 tree arg01 = TREE_OPERAND (arg0, 1);
11714 enum tree_code code0 = TREE_CODE (arg0);
11717 if (TREE_CODE (arg01) == REAL_CST)
11718 is_positive = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg01)) ? -1 : 1;
11720 is_positive = tree_int_cst_sgn (arg01);
11722 /* (X - c) > X becomes false. */
11723 if (code == GT_EXPR
11724 && ((code0 == MINUS_EXPR && is_positive >= 0)
11725 || (code0 == PLUS_EXPR && is_positive <= 0)))
11727 if (TREE_CODE (arg01) == INTEGER_CST
11728 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
11729 fold_overflow_warning (("assuming signed overflow does not "
11730 "occur when assuming that (X - c) > X "
11731 "is always false"),
11732 WARN_STRICT_OVERFLOW_ALL);
11733 return constant_boolean_node (0, type);
11736 /* Likewise (X + c) < X becomes false. */
11737 if (code == LT_EXPR
11738 && ((code0 == PLUS_EXPR && is_positive >= 0)
11739 || (code0 == MINUS_EXPR && is_positive <= 0)))
11741 if (TREE_CODE (arg01) == INTEGER_CST
11742 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
11743 fold_overflow_warning (("assuming signed overflow does not "
11744 "occur when assuming that "
11745 "(X + c) < X is always false"),
11746 WARN_STRICT_OVERFLOW_ALL);
11747 return constant_boolean_node (0, type);
11750 /* Convert (X - c) <= X to true. */
11751 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1)))
11753 && ((code0 == MINUS_EXPR && is_positive >= 0)
11754 || (code0 == PLUS_EXPR && is_positive <= 0)))
11756 if (TREE_CODE (arg01) == INTEGER_CST
11757 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
11758 fold_overflow_warning (("assuming signed overflow does not "
11759 "occur when assuming that "
11760 "(X - c) <= X is always true"),
11761 WARN_STRICT_OVERFLOW_ALL);
11762 return constant_boolean_node (1, type);
11765 /* Convert (X + c) >= X to true. */
11766 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1)))
11768 && ((code0 == PLUS_EXPR && is_positive >= 0)
11769 || (code0 == MINUS_EXPR && is_positive <= 0)))
11771 if (TREE_CODE (arg01) == INTEGER_CST
11772 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
11773 fold_overflow_warning (("assuming signed overflow does not "
11774 "occur when assuming that "
11775 "(X + c) >= X is always true"),
11776 WARN_STRICT_OVERFLOW_ALL);
11777 return constant_boolean_node (1, type);
11780 if (TREE_CODE (arg01) == INTEGER_CST)
11782 /* Convert X + c > X and X - c < X to true for integers. */
11783 if (code == GT_EXPR
11784 && ((code0 == PLUS_EXPR && is_positive > 0)
11785 || (code0 == MINUS_EXPR && is_positive < 0)))
11787 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
11788 fold_overflow_warning (("assuming signed overflow does "
11789 "not occur when assuming that "
11790 "(X + c) > X is always true"),
11791 WARN_STRICT_OVERFLOW_ALL);
11792 return constant_boolean_node (1, type);
11795 if (code == LT_EXPR
11796 && ((code0 == MINUS_EXPR && is_positive > 0)
11797 || (code0 == PLUS_EXPR && is_positive < 0)))
11799 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
11800 fold_overflow_warning (("assuming signed overflow does "
11801 "not occur when assuming that "
11802 "(X - c) < X is always true"),
11803 WARN_STRICT_OVERFLOW_ALL);
11804 return constant_boolean_node (1, type);
11807 /* Convert X + c <= X and X - c >= X to false for integers. */
11808 if (code == LE_EXPR
11809 && ((code0 == PLUS_EXPR && is_positive > 0)
11810 || (code0 == MINUS_EXPR && is_positive < 0)))
11812 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
11813 fold_overflow_warning (("assuming signed overflow does "
11814 "not occur when assuming that "
11815 "(X + c) <= X is always false"),
11816 WARN_STRICT_OVERFLOW_ALL);
11817 return constant_boolean_node (0, type);
11820 if (code == GE_EXPR
11821 && ((code0 == MINUS_EXPR && is_positive > 0)
11822 || (code0 == PLUS_EXPR && is_positive < 0)))
11824 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
11825 fold_overflow_warning (("assuming signed overflow does "
11826 "not occur when assuming that "
11827 "(X - c) >= X is always false"),
11828 WARN_STRICT_OVERFLOW_ALL);
11829 return constant_boolean_node (0, type);
11834 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
11835 This transformation affects the cases which are handled in later
11836 optimizations involving comparisons with non-negative constants. */
11837 if (TREE_CODE (arg1) == INTEGER_CST
11838 && TREE_CODE (arg0) != INTEGER_CST
11839 && tree_int_cst_sgn (arg1) > 0)
11841 if (code == GE_EXPR)
11843 arg1 = const_binop (MINUS_EXPR, arg1,
11844 build_int_cst (TREE_TYPE (arg1), 1), 0);
11845 return fold_build2 (GT_EXPR, type, arg0,
11846 fold_convert (TREE_TYPE (arg0), arg1));
11848 if (code == LT_EXPR)
11850 arg1 = const_binop (MINUS_EXPR, arg1,
11851 build_int_cst (TREE_TYPE (arg1), 1), 0);
11852 return fold_build2 (LE_EXPR, type, arg0,
11853 fold_convert (TREE_TYPE (arg0), arg1));
11857 /* Comparisons with the highest or lowest possible integer of
11858 the specified precision will have known values. */
11860 tree arg1_type = TREE_TYPE (arg1);
11861 unsigned int width = TYPE_PRECISION (arg1_type);
11863 if (TREE_CODE (arg1) == INTEGER_CST
11864 && !TREE_OVERFLOW (arg1)
11865 && width <= 2 * HOST_BITS_PER_WIDE_INT
11866 && (INTEGRAL_TYPE_P (arg1_type) || POINTER_TYPE_P (arg1_type)))
11868 HOST_WIDE_INT signed_max_hi;
11869 unsigned HOST_WIDE_INT signed_max_lo;
11870 unsigned HOST_WIDE_INT max_hi, max_lo, min_hi, min_lo;
11872 if (width <= HOST_BITS_PER_WIDE_INT)
11874 signed_max_lo = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
11879 if (TYPE_UNSIGNED (arg1_type))
11881 max_lo = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
11887 max_lo = signed_max_lo;
11888 min_lo = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
11894 width -= HOST_BITS_PER_WIDE_INT;
11895 signed_max_lo = -1;
11896 signed_max_hi = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
11901 if (TYPE_UNSIGNED (arg1_type))
11903 max_hi = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
11908 max_hi = signed_max_hi;
11909 min_hi = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
11913 if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1) == max_hi
11914 && TREE_INT_CST_LOW (arg1) == max_lo)
11918 return omit_one_operand (type, integer_zero_node, arg0);
11921 return fold_build2 (EQ_EXPR, type, op0, op1);
11924 return omit_one_operand (type, integer_one_node, arg0);
11927 return fold_build2 (NE_EXPR, type, op0, op1);
11929 /* The GE_EXPR and LT_EXPR cases above are not normally
11930 reached because of previous transformations. */
11935 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
11937 && TREE_INT_CST_LOW (arg1) == max_lo - 1)
11941 arg1 = const_binop (PLUS_EXPR, arg1,
11942 build_int_cst (TREE_TYPE (arg1), 1), 0);
11943 return fold_build2 (EQ_EXPR, type,
11944 fold_convert (TREE_TYPE (arg1), arg0),
11947 arg1 = const_binop (PLUS_EXPR, arg1,
11948 build_int_cst (TREE_TYPE (arg1), 1), 0);
11949 return fold_build2 (NE_EXPR, type,
11950 fold_convert (TREE_TYPE (arg1), arg0),
11955 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
11957 && TREE_INT_CST_LOW (arg1) == min_lo)
11961 return omit_one_operand (type, integer_zero_node, arg0);
11964 return fold_build2 (EQ_EXPR, type, op0, op1);
11967 return omit_one_operand (type, integer_one_node, arg0);
11970 return fold_build2 (NE_EXPR, type, op0, op1);
11975 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
11977 && TREE_INT_CST_LOW (arg1) == min_lo + 1)
11981 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
11982 return fold_build2 (NE_EXPR, type,
11983 fold_convert (TREE_TYPE (arg1), arg0),
11986 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
11987 return fold_build2 (EQ_EXPR, type,
11988 fold_convert (TREE_TYPE (arg1), arg0),
11994 else if (TREE_INT_CST_HIGH (arg1) == signed_max_hi
11995 && TREE_INT_CST_LOW (arg1) == signed_max_lo
11996 && TYPE_UNSIGNED (arg1_type)
11997 /* We will flip the signedness of the comparison operator
11998 associated with the mode of arg1, so the sign bit is
11999 specified by this mode. Check that arg1 is the signed
12000 max associated with this sign bit. */
12001 && width == GET_MODE_BITSIZE (TYPE_MODE (arg1_type))
12002 /* signed_type does not work on pointer types. */
12003 && INTEGRAL_TYPE_P (arg1_type))
12005 /* The following case also applies to X < signed_max+1
12006 and X >= signed_max+1 because previous transformations. */
12007 if (code == LE_EXPR || code == GT_EXPR)
12010 st = lang_hooks.types.signed_type (TREE_TYPE (arg1));
12011 return fold_build2 (code == LE_EXPR ? GE_EXPR : LT_EXPR,
12012 type, fold_convert (st, arg0),
12013 build_int_cst (st, 0));
12019 /* If we are comparing an ABS_EXPR with a constant, we can
12020 convert all the cases into explicit comparisons, but they may
12021 well not be faster than doing the ABS and one comparison.
12022 But ABS (X) <= C is a range comparison, which becomes a subtraction
12023 and a comparison, and is probably faster. */
12024 if (code == LE_EXPR
12025 && TREE_CODE (arg1) == INTEGER_CST
12026 && TREE_CODE (arg0) == ABS_EXPR
12027 && ! TREE_SIDE_EFFECTS (arg0)
12028 && (0 != (tem = negate_expr (arg1)))
12029 && TREE_CODE (tem) == INTEGER_CST
12030 && !TREE_OVERFLOW (tem))
12031 return fold_build2 (TRUTH_ANDIF_EXPR, type,
12032 build2 (GE_EXPR, type,
12033 TREE_OPERAND (arg0, 0), tem),
12034 build2 (LE_EXPR, type,
12035 TREE_OPERAND (arg0, 0), arg1));
12037 /* Convert ABS_EXPR<x> >= 0 to true. */
12038 strict_overflow_p = false;
12039 if (code == GE_EXPR
12040 && (integer_zerop (arg1)
12041 || (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
12042 && real_zerop (arg1)))
12043 && tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p))
12045 if (strict_overflow_p)
12046 fold_overflow_warning (("assuming signed overflow does not occur "
12047 "when simplifying comparison of "
12048 "absolute value and zero"),
12049 WARN_STRICT_OVERFLOW_CONDITIONAL);
12050 return omit_one_operand (type, integer_one_node, arg0);
12053 /* Convert ABS_EXPR<x> < 0 to false. */
12054 strict_overflow_p = false;
12055 if (code == LT_EXPR
12056 && (integer_zerop (arg1) || real_zerop (arg1))
12057 && tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p))
12059 if (strict_overflow_p)
12060 fold_overflow_warning (("assuming signed overflow does not occur "
12061 "when simplifying comparison of "
12062 "absolute value and zero"),
12063 WARN_STRICT_OVERFLOW_CONDITIONAL);
12064 return omit_one_operand (type, integer_zero_node, arg0);
12067 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
12068 and similarly for >= into !=. */
12069 if ((code == LT_EXPR || code == GE_EXPR)
12070 && TYPE_UNSIGNED (TREE_TYPE (arg0))
12071 && TREE_CODE (arg1) == LSHIFT_EXPR
12072 && integer_onep (TREE_OPERAND (arg1, 0)))
12073 return build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
12074 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
12075 TREE_OPERAND (arg1, 1)),
12076 build_int_cst (TREE_TYPE (arg0), 0));
12078 if ((code == LT_EXPR || code == GE_EXPR)
12079 && TYPE_UNSIGNED (TREE_TYPE (arg0))
12080 && (TREE_CODE (arg1) == NOP_EXPR
12081 || TREE_CODE (arg1) == CONVERT_EXPR)
12082 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
12083 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
12085 build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
12086 fold_convert (TREE_TYPE (arg0),
12087 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
12088 TREE_OPERAND (TREE_OPERAND (arg1, 0),
12090 build_int_cst (TREE_TYPE (arg0), 0));
12094 case UNORDERED_EXPR:
12102 if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
12104 t1 = fold_relational_const (code, type, arg0, arg1);
12105 if (t1 != NULL_TREE)
12109 /* If the first operand is NaN, the result is constant. */
12110 if (TREE_CODE (arg0) == REAL_CST
12111 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
12112 && (code != LTGT_EXPR || ! flag_trapping_math))
12114 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
12115 ? integer_zero_node
12116 : integer_one_node;
12117 return omit_one_operand (type, t1, arg1);
12120 /* If the second operand is NaN, the result is constant. */
12121 if (TREE_CODE (arg1) == REAL_CST
12122 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg1))
12123 && (code != LTGT_EXPR || ! flag_trapping_math))
12125 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
12126 ? integer_zero_node
12127 : integer_one_node;
12128 return omit_one_operand (type, t1, arg0);
12131 /* Simplify unordered comparison of something with itself. */
12132 if ((code == UNLE_EXPR || code == UNGE_EXPR || code == UNEQ_EXPR)
12133 && operand_equal_p (arg0, arg1, 0))
12134 return constant_boolean_node (1, type);
12136 if (code == LTGT_EXPR
12137 && !flag_trapping_math
12138 && operand_equal_p (arg0, arg1, 0))
12139 return constant_boolean_node (0, type);
12141 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
12143 tree targ0 = strip_float_extensions (arg0);
12144 tree targ1 = strip_float_extensions (arg1);
12145 tree newtype = TREE_TYPE (targ0);
12147 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
12148 newtype = TREE_TYPE (targ1);
12150 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
12151 return fold_build2 (code, type, fold_convert (newtype, targ0),
12152 fold_convert (newtype, targ1));
12157 case COMPOUND_EXPR:
12158 /* When pedantic, a compound expression can be neither an lvalue
12159 nor an integer constant expression. */
12160 if (TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
12162 /* Don't let (0, 0) be null pointer constant. */
12163 tem = integer_zerop (arg1) ? build1 (NOP_EXPR, type, arg1)
12164 : fold_convert (type, arg1);
12165 return pedantic_non_lvalue (tem);
12168 if ((TREE_CODE (arg0) == REAL_CST
12169 && TREE_CODE (arg1) == REAL_CST)
12170 || (TREE_CODE (arg0) == INTEGER_CST
12171 && TREE_CODE (arg1) == INTEGER_CST))
12172 return build_complex (type, arg0, arg1);
12176 /* An ASSERT_EXPR should never be passed to fold_binary. */
12177 gcc_unreachable ();
12181 } /* switch (code) */
12184 /* Callback for walk_tree, looking for LABEL_EXPR.
12185 Returns tree TP if it is LABEL_EXPR. Otherwise it returns NULL_TREE.
12186 Do not check the sub-tree of GOTO_EXPR. */
12189 contains_label_1 (tree *tp,
12190 int *walk_subtrees,
12191 void *data ATTRIBUTE_UNUSED)
12193 switch (TREE_CODE (*tp))
12198 *walk_subtrees = 0;
12205 /* Checks whether the sub-tree ST contains a label LABEL_EXPR which is
12206 accessible from outside the sub-tree. Returns NULL_TREE if no
12207 addressable label is found. */
12210 contains_label_p (tree st)
12212 return (walk_tree (&st, contains_label_1 , NULL, NULL) != NULL_TREE);
12215 /* Fold a ternary expression of code CODE and type TYPE with operands
12216 OP0, OP1, and OP2. Return the folded expression if folding is
12217 successful. Otherwise, return NULL_TREE. */
12220 fold_ternary (enum tree_code code, tree type, tree op0, tree op1, tree op2)
12223 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
12224 enum tree_code_class kind = TREE_CODE_CLASS (code);
12226 gcc_assert (IS_EXPR_CODE_CLASS (kind)
12227 && TREE_CODE_LENGTH (code) == 3);
12229 /* Strip any conversions that don't change the mode. This is safe
12230 for every expression, except for a comparison expression because
12231 its signedness is derived from its operands. So, in the latter
12232 case, only strip conversions that don't change the signedness.
12234 Note that this is done as an internal manipulation within the
12235 constant folder, in order to find the simplest representation of
12236 the arguments so that their form can be studied. In any cases,
12237 the appropriate type conversions should be put back in the tree
12238 that will get out of the constant folder. */
12253 case COMPONENT_REF:
12254 if (TREE_CODE (arg0) == CONSTRUCTOR
12255 && ! type_contains_placeholder_p (TREE_TYPE (arg0)))
12257 unsigned HOST_WIDE_INT idx;
12259 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (arg0), idx, field, value)
12266 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
12267 so all simple results must be passed through pedantic_non_lvalue. */
12268 if (TREE_CODE (arg0) == INTEGER_CST)
12270 tree unused_op = integer_zerop (arg0) ? op1 : op2;
12271 tem = integer_zerop (arg0) ? op2 : op1;
12272 /* Only optimize constant conditions when the selected branch
12273 has the same type as the COND_EXPR. This avoids optimizing
12274 away "c ? x : throw", where the throw has a void type.
12275 Avoid throwing away that operand which contains label. */
12276 if ((!TREE_SIDE_EFFECTS (unused_op)
12277 || !contains_label_p (unused_op))
12278 && (! VOID_TYPE_P (TREE_TYPE (tem))
12279 || VOID_TYPE_P (type)))
12280 return pedantic_non_lvalue (tem);
12283 if (operand_equal_p (arg1, op2, 0))
12284 return pedantic_omit_one_operand (type, arg1, arg0);
12286 /* If we have A op B ? A : C, we may be able to convert this to a
12287 simpler expression, depending on the operation and the values
12288 of B and C. Signed zeros prevent all of these transformations,
12289 for reasons given above each one.
12291 Also try swapping the arguments and inverting the conditional. */
12292 if (COMPARISON_CLASS_P (arg0)
12293 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
12294 arg1, TREE_OPERAND (arg0, 1))
12295 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
12297 tem = fold_cond_expr_with_comparison (type, arg0, op1, op2);
12302 if (COMPARISON_CLASS_P (arg0)
12303 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
12305 TREE_OPERAND (arg0, 1))
12306 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (op2))))
12308 tem = fold_truth_not_expr (arg0);
12309 if (tem && COMPARISON_CLASS_P (tem))
12311 tem = fold_cond_expr_with_comparison (type, tem, op2, op1);
12317 /* If the second operand is simpler than the third, swap them
12318 since that produces better jump optimization results. */
12319 if (truth_value_p (TREE_CODE (arg0))
12320 && tree_swap_operands_p (op1, op2, false))
12322 /* See if this can be inverted. If it can't, possibly because
12323 it was a floating-point inequality comparison, don't do
12325 tem = fold_truth_not_expr (arg0);
12327 return fold_build3 (code, type, tem, op2, op1);
12330 /* Convert A ? 1 : 0 to simply A. */
12331 if (integer_onep (op1)
12332 && integer_zerop (op2)
12333 /* If we try to convert OP0 to our type, the
12334 call to fold will try to move the conversion inside
12335 a COND, which will recurse. In that case, the COND_EXPR
12336 is probably the best choice, so leave it alone. */
12337 && type == TREE_TYPE (arg0))
12338 return pedantic_non_lvalue (arg0);
12340 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
12341 over COND_EXPR in cases such as floating point comparisons. */
12342 if (integer_zerop (op1)
12343 && integer_onep (op2)
12344 && truth_value_p (TREE_CODE (arg0)))
12345 return pedantic_non_lvalue (fold_convert (type,
12346 invert_truthvalue (arg0)));
12348 /* A < 0 ? <sign bit of A> : 0 is simply (A & <sign bit of A>). */
12349 if (TREE_CODE (arg0) == LT_EXPR
12350 && integer_zerop (TREE_OPERAND (arg0, 1))
12351 && integer_zerop (op2)
12352 && (tem = sign_bit_p (TREE_OPERAND (arg0, 0), arg1)))
12354 /* sign_bit_p only checks ARG1 bits within A's precision.
12355 If <sign bit of A> has wider type than A, bits outside
12356 of A's precision in <sign bit of A> need to be checked.
12357 If they are all 0, this optimization needs to be done
12358 in unsigned A's type, if they are all 1 in signed A's type,
12359 otherwise this can't be done. */
12360 if (TYPE_PRECISION (TREE_TYPE (tem))
12361 < TYPE_PRECISION (TREE_TYPE (arg1))
12362 && TYPE_PRECISION (TREE_TYPE (tem))
12363 < TYPE_PRECISION (type))
12365 unsigned HOST_WIDE_INT mask_lo;
12366 HOST_WIDE_INT mask_hi;
12367 int inner_width, outer_width;
12370 inner_width = TYPE_PRECISION (TREE_TYPE (tem));
12371 outer_width = TYPE_PRECISION (TREE_TYPE (arg1));
12372 if (outer_width > TYPE_PRECISION (type))
12373 outer_width = TYPE_PRECISION (type);
12375 if (outer_width > HOST_BITS_PER_WIDE_INT)
12377 mask_hi = ((unsigned HOST_WIDE_INT) -1
12378 >> (2 * HOST_BITS_PER_WIDE_INT - outer_width));
12384 mask_lo = ((unsigned HOST_WIDE_INT) -1
12385 >> (HOST_BITS_PER_WIDE_INT - outer_width));
12387 if (inner_width > HOST_BITS_PER_WIDE_INT)
12389 mask_hi &= ~((unsigned HOST_WIDE_INT) -1
12390 >> (HOST_BITS_PER_WIDE_INT - inner_width));
12394 mask_lo &= ~((unsigned HOST_WIDE_INT) -1
12395 >> (HOST_BITS_PER_WIDE_INT - inner_width));
12397 if ((TREE_INT_CST_HIGH (arg1) & mask_hi) == mask_hi
12398 && (TREE_INT_CST_LOW (arg1) & mask_lo) == mask_lo)
12400 tem_type = lang_hooks.types.signed_type (TREE_TYPE (tem));
12401 tem = fold_convert (tem_type, tem);
12403 else if ((TREE_INT_CST_HIGH (arg1) & mask_hi) == 0
12404 && (TREE_INT_CST_LOW (arg1) & mask_lo) == 0)
12406 tem_type = lang_hooks.types.unsigned_type (TREE_TYPE (tem));
12407 tem = fold_convert (tem_type, tem);
12414 return fold_convert (type,
12415 fold_build2 (BIT_AND_EXPR,
12416 TREE_TYPE (tem), tem,
12417 fold_convert (TREE_TYPE (tem),
12421 /* (A >> N) & 1 ? (1 << N) : 0 is simply A & (1 << N). A & 1 was
12422 already handled above. */
12423 if (TREE_CODE (arg0) == BIT_AND_EXPR
12424 && integer_onep (TREE_OPERAND (arg0, 1))
12425 && integer_zerop (op2)
12426 && integer_pow2p (arg1))
12428 tree tem = TREE_OPERAND (arg0, 0);
12430 if (TREE_CODE (tem) == RSHIFT_EXPR
12431 && TREE_CODE (TREE_OPERAND (tem, 1)) == INTEGER_CST
12432 && (unsigned HOST_WIDE_INT) tree_log2 (arg1) ==
12433 TREE_INT_CST_LOW (TREE_OPERAND (tem, 1)))
12434 return fold_build2 (BIT_AND_EXPR, type,
12435 TREE_OPERAND (tem, 0), arg1);
12438 /* A & N ? N : 0 is simply A & N if N is a power of two. This
12439 is probably obsolete because the first operand should be a
12440 truth value (that's why we have the two cases above), but let's
12441 leave it in until we can confirm this for all front-ends. */
12442 if (integer_zerop (op2)
12443 && TREE_CODE (arg0) == NE_EXPR
12444 && integer_zerop (TREE_OPERAND (arg0, 1))
12445 && integer_pow2p (arg1)
12446 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
12447 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
12448 arg1, OEP_ONLY_CONST))
12449 return pedantic_non_lvalue (fold_convert (type,
12450 TREE_OPERAND (arg0, 0)));
12452 /* Convert A ? B : 0 into A && B if A and B are truth values. */
12453 if (integer_zerop (op2)
12454 && truth_value_p (TREE_CODE (arg0))
12455 && truth_value_p (TREE_CODE (arg1)))
12456 return fold_build2 (TRUTH_ANDIF_EXPR, type,
12457 fold_convert (type, arg0),
12460 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
12461 if (integer_onep (op2)
12462 && truth_value_p (TREE_CODE (arg0))
12463 && truth_value_p (TREE_CODE (arg1)))
12465 /* Only perform transformation if ARG0 is easily inverted. */
12466 tem = fold_truth_not_expr (arg0);
12468 return fold_build2 (TRUTH_ORIF_EXPR, type,
12469 fold_convert (type, tem),
12473 /* Convert A ? 0 : B into !A && B if A and B are truth values. */
12474 if (integer_zerop (arg1)
12475 && truth_value_p (TREE_CODE (arg0))
12476 && truth_value_p (TREE_CODE (op2)))
12478 /* Only perform transformation if ARG0 is easily inverted. */
12479 tem = fold_truth_not_expr (arg0);
12481 return fold_build2 (TRUTH_ANDIF_EXPR, type,
12482 fold_convert (type, tem),
12486 /* Convert A ? 1 : B into A || B if A and B are truth values. */
12487 if (integer_onep (arg1)
12488 && truth_value_p (TREE_CODE (arg0))
12489 && truth_value_p (TREE_CODE (op2)))
12490 return fold_build2 (TRUTH_ORIF_EXPR, type,
12491 fold_convert (type, arg0),
12497 /* CALL_EXPRs used to be ternary exprs. Catch any mistaken uses
12498 of fold_ternary on them. */
12499 gcc_unreachable ();
12501 case BIT_FIELD_REF:
12502 if ((TREE_CODE (arg0) == VECTOR_CST
12503 || (TREE_CODE (arg0) == CONSTRUCTOR && TREE_CONSTANT (arg0)))
12504 && type == TREE_TYPE (TREE_TYPE (arg0))
12505 && host_integerp (arg1, 1)
12506 && host_integerp (op2, 1))
12508 unsigned HOST_WIDE_INT width = tree_low_cst (arg1, 1);
12509 unsigned HOST_WIDE_INT idx = tree_low_cst (op2, 1);
12512 && simple_cst_equal (arg1, TYPE_SIZE (type)) == 1
12513 && (idx % width) == 0
12514 && (idx = idx / width)
12515 < TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0)))
12517 tree elements = NULL_TREE;
12519 if (TREE_CODE (arg0) == VECTOR_CST)
12520 elements = TREE_VECTOR_CST_ELTS (arg0);
12523 unsigned HOST_WIDE_INT idx;
12526 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (arg0), idx, value)
12527 elements = tree_cons (NULL_TREE, value, elements);
12529 while (idx-- > 0 && elements)
12530 elements = TREE_CHAIN (elements);
12532 return TREE_VALUE (elements);
12534 return fold_convert (type, integer_zero_node);
12541 } /* switch (code) */
12544 /* Perform constant folding and related simplification of EXPR.
12545 The related simplifications include x*1 => x, x*0 => 0, etc.,
12546 and application of the associative law.
12547 NOP_EXPR conversions may be removed freely (as long as we
12548 are careful not to change the type of the overall expression).
12549 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
12550 but we can constant-fold them if they have constant operands. */
12552 #ifdef ENABLE_FOLD_CHECKING
12553 # define fold(x) fold_1 (x)
12554 static tree fold_1 (tree);
12560 const tree t = expr;
12561 enum tree_code code = TREE_CODE (t);
12562 enum tree_code_class kind = TREE_CODE_CLASS (code);
12565 /* Return right away if a constant. */
12566 if (kind == tcc_constant)
12569 /* CALL_EXPR-like objects with variable numbers of operands are
12570 treated specially. */
12571 if (kind == tcc_vl_exp)
12573 if (code == CALL_EXPR)
12575 tem = fold_call_expr (expr, false);
12576 return tem ? tem : expr;
12581 if (IS_EXPR_CODE_CLASS (kind)
12582 || IS_GIMPLE_STMT_CODE_CLASS (kind))
12584 tree type = TREE_TYPE (t);
12585 tree op0, op1, op2;
12587 switch (TREE_CODE_LENGTH (code))
12590 op0 = TREE_OPERAND (t, 0);
12591 tem = fold_unary (code, type, op0);
12592 return tem ? tem : expr;
12594 op0 = TREE_OPERAND (t, 0);
12595 op1 = TREE_OPERAND (t, 1);
12596 tem = fold_binary (code, type, op0, op1);
12597 return tem ? tem : expr;
12599 op0 = TREE_OPERAND (t, 0);
12600 op1 = TREE_OPERAND (t, 1);
12601 op2 = TREE_OPERAND (t, 2);
12602 tem = fold_ternary (code, type, op0, op1, op2);
12603 return tem ? tem : expr;
12612 return fold (DECL_INITIAL (t));
12616 } /* switch (code) */
12619 #ifdef ENABLE_FOLD_CHECKING
12622 static void fold_checksum_tree (tree, struct md5_ctx *, htab_t);
12623 static void fold_check_failed (tree, tree);
12624 void print_fold_checksum (tree);
12626 /* When --enable-checking=fold, compute a digest of expr before
12627 and after actual fold call to see if fold did not accidentally
12628 change original expr. */
12634 struct md5_ctx ctx;
12635 unsigned char checksum_before[16], checksum_after[16];
12638 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
12639 md5_init_ctx (&ctx);
12640 fold_checksum_tree (expr, &ctx, ht);
12641 md5_finish_ctx (&ctx, checksum_before);
12644 ret = fold_1 (expr);
12646 md5_init_ctx (&ctx);
12647 fold_checksum_tree (expr, &ctx, ht);
12648 md5_finish_ctx (&ctx, checksum_after);
12651 if (memcmp (checksum_before, checksum_after, 16))
12652 fold_check_failed (expr, ret);
12658 print_fold_checksum (tree expr)
12660 struct md5_ctx ctx;
12661 unsigned char checksum[16], cnt;
12664 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
12665 md5_init_ctx (&ctx);
12666 fold_checksum_tree (expr, &ctx, ht);
12667 md5_finish_ctx (&ctx, checksum);
12669 for (cnt = 0; cnt < 16; ++cnt)
12670 fprintf (stderr, "%02x", checksum[cnt]);
12671 putc ('\n', stderr);
12675 fold_check_failed (tree expr ATTRIBUTE_UNUSED, tree ret ATTRIBUTE_UNUSED)
12677 internal_error ("fold check: original tree changed by fold");
12681 fold_checksum_tree (tree expr, struct md5_ctx *ctx, htab_t ht)
12684 enum tree_code code;
12685 struct tree_function_decl buf;
12690 gcc_assert ((sizeof (struct tree_exp) + 5 * sizeof (tree)
12691 <= sizeof (struct tree_function_decl))
12692 && sizeof (struct tree_type) <= sizeof (struct tree_function_decl));
12695 slot = htab_find_slot (ht, expr, INSERT);
12699 code = TREE_CODE (expr);
12700 if (TREE_CODE_CLASS (code) == tcc_declaration
12701 && DECL_ASSEMBLER_NAME_SET_P (expr))
12703 /* Allow DECL_ASSEMBLER_NAME to be modified. */
12704 memcpy ((char *) &buf, expr, tree_size (expr));
12705 expr = (tree) &buf;
12706 SET_DECL_ASSEMBLER_NAME (expr, NULL);
12708 else if (TREE_CODE_CLASS (code) == tcc_type
12709 && (TYPE_POINTER_TO (expr) || TYPE_REFERENCE_TO (expr)
12710 || TYPE_CACHED_VALUES_P (expr)
12711 || TYPE_CONTAINS_PLACEHOLDER_INTERNAL (expr)))
12713 /* Allow these fields to be modified. */
12714 memcpy ((char *) &buf, expr, tree_size (expr));
12715 expr = (tree) &buf;
12716 TYPE_CONTAINS_PLACEHOLDER_INTERNAL (expr) = 0;
12717 TYPE_POINTER_TO (expr) = NULL;
12718 TYPE_REFERENCE_TO (expr) = NULL;
12719 if (TYPE_CACHED_VALUES_P (expr))
12721 TYPE_CACHED_VALUES_P (expr) = 0;
12722 TYPE_CACHED_VALUES (expr) = NULL;
12725 md5_process_bytes (expr, tree_size (expr), ctx);
12726 fold_checksum_tree (TREE_TYPE (expr), ctx, ht);
12727 if (TREE_CODE_CLASS (code) != tcc_type
12728 && TREE_CODE_CLASS (code) != tcc_declaration
12729 && code != TREE_LIST)
12730 fold_checksum_tree (TREE_CHAIN (expr), ctx, ht);
12731 switch (TREE_CODE_CLASS (code))
12737 md5_process_bytes (TREE_STRING_POINTER (expr),
12738 TREE_STRING_LENGTH (expr), ctx);
12741 fold_checksum_tree (TREE_REALPART (expr), ctx, ht);
12742 fold_checksum_tree (TREE_IMAGPART (expr), ctx, ht);
12745 fold_checksum_tree (TREE_VECTOR_CST_ELTS (expr), ctx, ht);
12751 case tcc_exceptional:
12755 fold_checksum_tree (TREE_PURPOSE (expr), ctx, ht);
12756 fold_checksum_tree (TREE_VALUE (expr), ctx, ht);
12757 expr = TREE_CHAIN (expr);
12758 goto recursive_label;
12761 for (i = 0; i < TREE_VEC_LENGTH (expr); ++i)
12762 fold_checksum_tree (TREE_VEC_ELT (expr, i), ctx, ht);
12768 case tcc_expression:
12769 case tcc_reference:
12770 case tcc_comparison:
12773 case tcc_statement:
12775 len = TREE_OPERAND_LENGTH (expr);
12776 for (i = 0; i < len; ++i)
12777 fold_checksum_tree (TREE_OPERAND (expr, i), ctx, ht);
12779 case tcc_declaration:
12780 fold_checksum_tree (DECL_NAME (expr), ctx, ht);
12781 fold_checksum_tree (DECL_CONTEXT (expr), ctx, ht);
12782 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_COMMON))
12784 fold_checksum_tree (DECL_SIZE (expr), ctx, ht);
12785 fold_checksum_tree (DECL_SIZE_UNIT (expr), ctx, ht);
12786 fold_checksum_tree (DECL_INITIAL (expr), ctx, ht);
12787 fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr), ctx, ht);
12788 fold_checksum_tree (DECL_ATTRIBUTES (expr), ctx, ht);
12790 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_WITH_VIS))
12791 fold_checksum_tree (DECL_SECTION_NAME (expr), ctx, ht);
12793 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_NON_COMMON))
12795 fold_checksum_tree (DECL_VINDEX (expr), ctx, ht);
12796 fold_checksum_tree (DECL_RESULT_FLD (expr), ctx, ht);
12797 fold_checksum_tree (DECL_ARGUMENT_FLD (expr), ctx, ht);
12801 if (TREE_CODE (expr) == ENUMERAL_TYPE)
12802 fold_checksum_tree (TYPE_VALUES (expr), ctx, ht);
12803 fold_checksum_tree (TYPE_SIZE (expr), ctx, ht);
12804 fold_checksum_tree (TYPE_SIZE_UNIT (expr), ctx, ht);
12805 fold_checksum_tree (TYPE_ATTRIBUTES (expr), ctx, ht);
12806 fold_checksum_tree (TYPE_NAME (expr), ctx, ht);
12807 if (INTEGRAL_TYPE_P (expr)
12808 || SCALAR_FLOAT_TYPE_P (expr))
12810 fold_checksum_tree (TYPE_MIN_VALUE (expr), ctx, ht);
12811 fold_checksum_tree (TYPE_MAX_VALUE (expr), ctx, ht);
12813 fold_checksum_tree (TYPE_MAIN_VARIANT (expr), ctx, ht);
12814 if (TREE_CODE (expr) == RECORD_TYPE
12815 || TREE_CODE (expr) == UNION_TYPE
12816 || TREE_CODE (expr) == QUAL_UNION_TYPE)
12817 fold_checksum_tree (TYPE_BINFO (expr), ctx, ht);
12818 fold_checksum_tree (TYPE_CONTEXT (expr), ctx, ht);
12827 /* Fold a unary tree expression with code CODE of type TYPE with an
12828 operand OP0. Return a folded expression if successful. Otherwise,
12829 return a tree expression with code CODE of type TYPE with an
12833 fold_build1_stat (enum tree_code code, tree type, tree op0 MEM_STAT_DECL)
12836 #ifdef ENABLE_FOLD_CHECKING
12837 unsigned char checksum_before[16], checksum_after[16];
12838 struct md5_ctx ctx;
12841 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
12842 md5_init_ctx (&ctx);
12843 fold_checksum_tree (op0, &ctx, ht);
12844 md5_finish_ctx (&ctx, checksum_before);
12848 tem = fold_unary (code, type, op0);
12850 tem = build1_stat (code, type, op0 PASS_MEM_STAT);
12852 #ifdef ENABLE_FOLD_CHECKING
12853 md5_init_ctx (&ctx);
12854 fold_checksum_tree (op0, &ctx, ht);
12855 md5_finish_ctx (&ctx, checksum_after);
12858 if (memcmp (checksum_before, checksum_after, 16))
12859 fold_check_failed (op0, tem);
12864 /* Fold a binary tree expression with code CODE of type TYPE with
12865 operands OP0 and OP1. Return a folded expression if successful.
12866 Otherwise, return a tree expression with code CODE of type TYPE
12867 with operands OP0 and OP1. */
12870 fold_build2_stat (enum tree_code code, tree type, tree op0, tree op1
12874 #ifdef ENABLE_FOLD_CHECKING
12875 unsigned char checksum_before_op0[16],
12876 checksum_before_op1[16],
12877 checksum_after_op0[16],
12878 checksum_after_op1[16];
12879 struct md5_ctx ctx;
12882 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
12883 md5_init_ctx (&ctx);
12884 fold_checksum_tree (op0, &ctx, ht);
12885 md5_finish_ctx (&ctx, checksum_before_op0);
12888 md5_init_ctx (&ctx);
12889 fold_checksum_tree (op1, &ctx, ht);
12890 md5_finish_ctx (&ctx, checksum_before_op1);
12894 tem = fold_binary (code, type, op0, op1);
12896 tem = build2_stat (code, type, op0, op1 PASS_MEM_STAT);
12898 #ifdef ENABLE_FOLD_CHECKING
12899 md5_init_ctx (&ctx);
12900 fold_checksum_tree (op0, &ctx, ht);
12901 md5_finish_ctx (&ctx, checksum_after_op0);
12904 if (memcmp (checksum_before_op0, checksum_after_op0, 16))
12905 fold_check_failed (op0, tem);
12907 md5_init_ctx (&ctx);
12908 fold_checksum_tree (op1, &ctx, ht);
12909 md5_finish_ctx (&ctx, checksum_after_op1);
12912 if (memcmp (checksum_before_op1, checksum_after_op1, 16))
12913 fold_check_failed (op1, tem);
12918 /* Fold a ternary tree expression with code CODE of type TYPE with
12919 operands OP0, OP1, and OP2. Return a folded expression if
12920 successful. Otherwise, return a tree expression with code CODE of
12921 type TYPE with operands OP0, OP1, and OP2. */
12924 fold_build3_stat (enum tree_code code, tree type, tree op0, tree op1, tree op2
12928 #ifdef ENABLE_FOLD_CHECKING
12929 unsigned char checksum_before_op0[16],
12930 checksum_before_op1[16],
12931 checksum_before_op2[16],
12932 checksum_after_op0[16],
12933 checksum_after_op1[16],
12934 checksum_after_op2[16];
12935 struct md5_ctx ctx;
12938 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
12939 md5_init_ctx (&ctx);
12940 fold_checksum_tree (op0, &ctx, ht);
12941 md5_finish_ctx (&ctx, checksum_before_op0);
12944 md5_init_ctx (&ctx);
12945 fold_checksum_tree (op1, &ctx, ht);
12946 md5_finish_ctx (&ctx, checksum_before_op1);
12949 md5_init_ctx (&ctx);
12950 fold_checksum_tree (op2, &ctx, ht);
12951 md5_finish_ctx (&ctx, checksum_before_op2);
12955 gcc_assert (TREE_CODE_CLASS (code) != tcc_vl_exp);
12956 tem = fold_ternary (code, type, op0, op1, op2);
12958 tem = build3_stat (code, type, op0, op1, op2 PASS_MEM_STAT);
12960 #ifdef ENABLE_FOLD_CHECKING
12961 md5_init_ctx (&ctx);
12962 fold_checksum_tree (op0, &ctx, ht);
12963 md5_finish_ctx (&ctx, checksum_after_op0);
12966 if (memcmp (checksum_before_op0, checksum_after_op0, 16))
12967 fold_check_failed (op0, tem);
12969 md5_init_ctx (&ctx);
12970 fold_checksum_tree (op1, &ctx, ht);
12971 md5_finish_ctx (&ctx, checksum_after_op1);
12974 if (memcmp (checksum_before_op1, checksum_after_op1, 16))
12975 fold_check_failed (op1, tem);
12977 md5_init_ctx (&ctx);
12978 fold_checksum_tree (op2, &ctx, ht);
12979 md5_finish_ctx (&ctx, checksum_after_op2);
12982 if (memcmp (checksum_before_op2, checksum_after_op2, 16))
12983 fold_check_failed (op2, tem);
12988 /* Fold a CALL_EXPR expression of type TYPE with operands FN and NARGS
12989 arguments in ARGARRAY, and a null static chain.
12990 Return a folded expression if successful. Otherwise, return a CALL_EXPR
12991 of type TYPE from the given operands as constructed by build_call_array. */
12994 fold_build_call_array (tree type, tree fn, int nargs, tree *argarray)
12997 #ifdef ENABLE_FOLD_CHECKING
12998 unsigned char checksum_before_fn[16],
12999 checksum_before_arglist[16],
13000 checksum_after_fn[16],
13001 checksum_after_arglist[16];
13002 struct md5_ctx ctx;
13006 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13007 md5_init_ctx (&ctx);
13008 fold_checksum_tree (fn, &ctx, ht);
13009 md5_finish_ctx (&ctx, checksum_before_fn);
13012 md5_init_ctx (&ctx);
13013 for (i = 0; i < nargs; i++)
13014 fold_checksum_tree (argarray[i], &ctx, ht);
13015 md5_finish_ctx (&ctx, checksum_before_arglist);
13019 tem = fold_builtin_call_array (type, fn, nargs, argarray);
13021 #ifdef ENABLE_FOLD_CHECKING
13022 md5_init_ctx (&ctx);
13023 fold_checksum_tree (fn, &ctx, ht);
13024 md5_finish_ctx (&ctx, checksum_after_fn);
13027 if (memcmp (checksum_before_fn, checksum_after_fn, 16))
13028 fold_check_failed (fn, tem);
13030 md5_init_ctx (&ctx);
13031 for (i = 0; i < nargs; i++)
13032 fold_checksum_tree (argarray[i], &ctx, ht);
13033 md5_finish_ctx (&ctx, checksum_after_arglist);
13036 if (memcmp (checksum_before_arglist, checksum_after_arglist, 16))
13037 fold_check_failed (NULL_TREE, tem);
13042 /* Perform constant folding and related simplification of initializer
13043 expression EXPR. These behave identically to "fold_buildN" but ignore
13044 potential run-time traps and exceptions that fold must preserve. */
13046 #define START_FOLD_INIT \
13047 int saved_signaling_nans = flag_signaling_nans;\
13048 int saved_trapping_math = flag_trapping_math;\
13049 int saved_rounding_math = flag_rounding_math;\
13050 int saved_trapv = flag_trapv;\
13051 int saved_folding_initializer = folding_initializer;\
13052 flag_signaling_nans = 0;\
13053 flag_trapping_math = 0;\
13054 flag_rounding_math = 0;\
13056 folding_initializer = 1;
13058 #define END_FOLD_INIT \
13059 flag_signaling_nans = saved_signaling_nans;\
13060 flag_trapping_math = saved_trapping_math;\
13061 flag_rounding_math = saved_rounding_math;\
13062 flag_trapv = saved_trapv;\
13063 folding_initializer = saved_folding_initializer;
13066 fold_build1_initializer (enum tree_code code, tree type, tree op)
13071 result = fold_build1 (code, type, op);
13078 fold_build2_initializer (enum tree_code code, tree type, tree op0, tree op1)
13083 result = fold_build2 (code, type, op0, op1);
13090 fold_build3_initializer (enum tree_code code, tree type, tree op0, tree op1,
13096 result = fold_build3 (code, type, op0, op1, op2);
13103 fold_build_call_array_initializer (tree type, tree fn,
13104 int nargs, tree *argarray)
13109 result = fold_build_call_array (type, fn, nargs, argarray);
13115 #undef START_FOLD_INIT
13116 #undef END_FOLD_INIT
13118 /* Determine if first argument is a multiple of second argument. Return 0 if
13119 it is not, or we cannot easily determined it to be.
13121 An example of the sort of thing we care about (at this point; this routine
13122 could surely be made more general, and expanded to do what the *_DIV_EXPR's
13123 fold cases do now) is discovering that
13125 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
13131 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
13133 This code also handles discovering that
13135 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
13137 is a multiple of 8 so we don't have to worry about dealing with a
13138 possible remainder.
13140 Note that we *look* inside a SAVE_EXPR only to determine how it was
13141 calculated; it is not safe for fold to do much of anything else with the
13142 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
13143 at run time. For example, the latter example above *cannot* be implemented
13144 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
13145 evaluation time of the original SAVE_EXPR is not necessarily the same at
13146 the time the new expression is evaluated. The only optimization of this
13147 sort that would be valid is changing
13149 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
13153 SAVE_EXPR (I) * SAVE_EXPR (J)
13155 (where the same SAVE_EXPR (J) is used in the original and the
13156 transformed version). */
13159 multiple_of_p (tree type, tree top, tree bottom)
13161 if (operand_equal_p (top, bottom, 0))
13164 if (TREE_CODE (type) != INTEGER_TYPE)
13167 switch (TREE_CODE (top))
13170 /* Bitwise and provides a power of two multiple. If the mask is
13171 a multiple of BOTTOM then TOP is a multiple of BOTTOM. */
13172 if (!integer_pow2p (bottom))
13177 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
13178 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
13182 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
13183 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
13186 if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
13190 op1 = TREE_OPERAND (top, 1);
13191 /* const_binop may not detect overflow correctly,
13192 so check for it explicitly here. */
13193 if (TYPE_PRECISION (TREE_TYPE (size_one_node))
13194 > TREE_INT_CST_LOW (op1)
13195 && TREE_INT_CST_HIGH (op1) == 0
13196 && 0 != (t1 = fold_convert (type,
13197 const_binop (LSHIFT_EXPR,
13200 && !TREE_OVERFLOW (t1))
13201 return multiple_of_p (type, t1, bottom);
13206 /* Can't handle conversions from non-integral or wider integral type. */
13207 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
13208 || (TYPE_PRECISION (type)
13209 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
13212 /* .. fall through ... */
13215 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
13218 if (TREE_CODE (bottom) != INTEGER_CST
13219 || integer_zerop (bottom)
13220 || (TYPE_UNSIGNED (type)
13221 && (tree_int_cst_sgn (top) < 0
13222 || tree_int_cst_sgn (bottom) < 0)))
13224 return integer_zerop (int_const_binop (TRUNC_MOD_EXPR,
13232 /* Return true if `t' is known to be non-negative. If the return
13233 value is based on the assumption that signed overflow is undefined,
13234 set *STRICT_OVERFLOW_P to true; otherwise, don't change
13235 *STRICT_OVERFLOW_P. */
13238 tree_expr_nonnegative_warnv_p (tree t, bool *strict_overflow_p)
13240 if (t == error_mark_node)
13243 if (TYPE_UNSIGNED (TREE_TYPE (t)))
13246 switch (TREE_CODE (t))
13249 /* Query VRP to see if it has recorded any information about
13250 the range of this object. */
13251 return ssa_name_nonnegative_p (t);
13254 /* We can't return 1 if flag_wrapv is set because
13255 ABS_EXPR<INT_MIN> = INT_MIN. */
13256 if (!INTEGRAL_TYPE_P (TREE_TYPE (t)))
13258 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (t)))
13260 *strict_overflow_p = true;
13266 return tree_int_cst_sgn (t) >= 0;
13269 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
13272 if (FLOAT_TYPE_P (TREE_TYPE (t)))
13273 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
13275 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
13276 strict_overflow_p));
13278 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
13279 both unsigned and at least 2 bits shorter than the result. */
13280 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
13281 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
13282 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
13284 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
13285 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
13286 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
13287 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
13289 unsigned int prec = MAX (TYPE_PRECISION (inner1),
13290 TYPE_PRECISION (inner2)) + 1;
13291 return prec < TYPE_PRECISION (TREE_TYPE (t));
13297 if (FLOAT_TYPE_P (TREE_TYPE (t)))
13299 /* x * x for floating point x is always non-negative. */
13300 if (operand_equal_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1), 0))
13302 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
13304 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
13305 strict_overflow_p));
13308 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
13309 both unsigned and their total bits is shorter than the result. */
13310 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
13311 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
13312 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
13314 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
13315 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
13316 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
13317 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
13318 return TYPE_PRECISION (inner1) + TYPE_PRECISION (inner2)
13319 < TYPE_PRECISION (TREE_TYPE (t));
13325 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
13327 || tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
13328 strict_overflow_p));
13334 case TRUNC_DIV_EXPR:
13335 case CEIL_DIV_EXPR:
13336 case FLOOR_DIV_EXPR:
13337 case ROUND_DIV_EXPR:
13338 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
13340 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
13341 strict_overflow_p));
13343 case TRUNC_MOD_EXPR:
13344 case CEIL_MOD_EXPR:
13345 case FLOOR_MOD_EXPR:
13346 case ROUND_MOD_EXPR:
13348 case NON_LVALUE_EXPR:
13350 case FIX_TRUNC_EXPR:
13351 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
13352 strict_overflow_p);
13354 case COMPOUND_EXPR:
13356 case GIMPLE_MODIFY_STMT:
13357 return tree_expr_nonnegative_warnv_p (GENERIC_TREE_OPERAND (t, 1),
13358 strict_overflow_p);
13361 return tree_expr_nonnegative_warnv_p (expr_last (TREE_OPERAND (t, 1)),
13362 strict_overflow_p);
13365 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
13367 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 2),
13368 strict_overflow_p));
13372 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
13373 tree outer_type = TREE_TYPE (t);
13375 if (TREE_CODE (outer_type) == REAL_TYPE)
13377 if (TREE_CODE (inner_type) == REAL_TYPE)
13378 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
13379 strict_overflow_p);
13380 if (TREE_CODE (inner_type) == INTEGER_TYPE)
13382 if (TYPE_UNSIGNED (inner_type))
13384 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
13385 strict_overflow_p);
13388 else if (TREE_CODE (outer_type) == INTEGER_TYPE)
13390 if (TREE_CODE (inner_type) == REAL_TYPE)
13391 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t,0),
13392 strict_overflow_p);
13393 if (TREE_CODE (inner_type) == INTEGER_TYPE)
13394 return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
13395 && TYPE_UNSIGNED (inner_type);
13402 tree temp = TARGET_EXPR_SLOT (t);
13403 t = TARGET_EXPR_INITIAL (t);
13405 /* If the initializer is non-void, then it's a normal expression
13406 that will be assigned to the slot. */
13407 if (!VOID_TYPE_P (t))
13408 return tree_expr_nonnegative_warnv_p (t, strict_overflow_p);
13410 /* Otherwise, the initializer sets the slot in some way. One common
13411 way is an assignment statement at the end of the initializer. */
13414 if (TREE_CODE (t) == BIND_EXPR)
13415 t = expr_last (BIND_EXPR_BODY (t));
13416 else if (TREE_CODE (t) == TRY_FINALLY_EXPR
13417 || TREE_CODE (t) == TRY_CATCH_EXPR)
13418 t = expr_last (TREE_OPERAND (t, 0));
13419 else if (TREE_CODE (t) == STATEMENT_LIST)
13424 if ((TREE_CODE (t) == MODIFY_EXPR
13425 || TREE_CODE (t) == GIMPLE_MODIFY_STMT)
13426 && GENERIC_TREE_OPERAND (t, 0) == temp)
13427 return tree_expr_nonnegative_warnv_p (GENERIC_TREE_OPERAND (t, 1),
13428 strict_overflow_p);
13435 tree fndecl = get_callee_fndecl (t);
13436 if (fndecl && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
13437 switch (DECL_FUNCTION_CODE (fndecl))
13439 CASE_FLT_FN (BUILT_IN_ACOS):
13440 CASE_FLT_FN (BUILT_IN_ACOSH):
13441 CASE_FLT_FN (BUILT_IN_CABS):
13442 CASE_FLT_FN (BUILT_IN_COSH):
13443 CASE_FLT_FN (BUILT_IN_ERFC):
13444 CASE_FLT_FN (BUILT_IN_EXP):
13445 CASE_FLT_FN (BUILT_IN_EXP10):
13446 CASE_FLT_FN (BUILT_IN_EXP2):
13447 CASE_FLT_FN (BUILT_IN_FABS):
13448 CASE_FLT_FN (BUILT_IN_FDIM):
13449 CASE_FLT_FN (BUILT_IN_HYPOT):
13450 CASE_FLT_FN (BUILT_IN_POW10):
13451 CASE_INT_FN (BUILT_IN_FFS):
13452 CASE_INT_FN (BUILT_IN_PARITY):
13453 CASE_INT_FN (BUILT_IN_POPCOUNT):
13454 case BUILT_IN_BSWAP32:
13455 case BUILT_IN_BSWAP64:
13459 CASE_FLT_FN (BUILT_IN_SQRT):
13460 /* sqrt(-0.0) is -0.0. */
13461 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (t))))
13463 return tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 0),
13464 strict_overflow_p);
13466 CASE_FLT_FN (BUILT_IN_ASINH):
13467 CASE_FLT_FN (BUILT_IN_ATAN):
13468 CASE_FLT_FN (BUILT_IN_ATANH):
13469 CASE_FLT_FN (BUILT_IN_CBRT):
13470 CASE_FLT_FN (BUILT_IN_CEIL):
13471 CASE_FLT_FN (BUILT_IN_ERF):
13472 CASE_FLT_FN (BUILT_IN_EXPM1):
13473 CASE_FLT_FN (BUILT_IN_FLOOR):
13474 CASE_FLT_FN (BUILT_IN_FMOD):
13475 CASE_FLT_FN (BUILT_IN_FREXP):
13476 CASE_FLT_FN (BUILT_IN_LCEIL):
13477 CASE_FLT_FN (BUILT_IN_LDEXP):
13478 CASE_FLT_FN (BUILT_IN_LFLOOR):
13479 CASE_FLT_FN (BUILT_IN_LLCEIL):
13480 CASE_FLT_FN (BUILT_IN_LLFLOOR):
13481 CASE_FLT_FN (BUILT_IN_LLRINT):
13482 CASE_FLT_FN (BUILT_IN_LLROUND):
13483 CASE_FLT_FN (BUILT_IN_LRINT):
13484 CASE_FLT_FN (BUILT_IN_LROUND):
13485 CASE_FLT_FN (BUILT_IN_MODF):
13486 CASE_FLT_FN (BUILT_IN_NEARBYINT):
13487 CASE_FLT_FN (BUILT_IN_RINT):
13488 CASE_FLT_FN (BUILT_IN_ROUND):
13489 CASE_FLT_FN (BUILT_IN_SCALB):
13490 CASE_FLT_FN (BUILT_IN_SCALBLN):
13491 CASE_FLT_FN (BUILT_IN_SCALBN):
13492 CASE_FLT_FN (BUILT_IN_SIGNBIT):
13493 CASE_FLT_FN (BUILT_IN_SIGNIFICAND):
13494 CASE_FLT_FN (BUILT_IN_SINH):
13495 CASE_FLT_FN (BUILT_IN_TANH):
13496 CASE_FLT_FN (BUILT_IN_TRUNC):
13497 /* True if the 1st argument is nonnegative. */
13498 return tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 0),
13499 strict_overflow_p);
13501 CASE_FLT_FN (BUILT_IN_FMAX):
13502 /* True if the 1st OR 2nd arguments are nonnegative. */
13503 return (tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 0),
13505 || (tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 1),
13506 strict_overflow_p)));
13508 CASE_FLT_FN (BUILT_IN_FMIN):
13509 /* True if the 1st AND 2nd arguments are nonnegative. */
13510 return (tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 0),
13512 && (tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 1),
13513 strict_overflow_p)));
13515 CASE_FLT_FN (BUILT_IN_COPYSIGN):
13516 /* True if the 2nd argument is nonnegative. */
13517 return tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 1),
13518 strict_overflow_p);
13520 CASE_FLT_FN (BUILT_IN_POWI):
13521 /* True if the 1st argument is nonnegative or the second
13522 argument is an even integer. */
13523 if (TREE_CODE (CALL_EXPR_ARG (t, 1)) == INTEGER_CST)
13525 tree arg1 = CALL_EXPR_ARG (t, 1);
13526 if ((TREE_INT_CST_LOW (arg1) & 1) == 0)
13529 return tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 0),
13530 strict_overflow_p);
13532 CASE_FLT_FN (BUILT_IN_POW):
13533 /* True if the 1st argument is nonnegative or the second
13534 argument is an even integer valued real. */
13535 if (TREE_CODE (CALL_EXPR_ARG (t, 1)) == REAL_CST)
13540 c = TREE_REAL_CST (CALL_EXPR_ARG (t, 1));
13541 n = real_to_integer (&c);
13544 REAL_VALUE_TYPE cint;
13545 real_from_integer (&cint, VOIDmode, n,
13546 n < 0 ? -1 : 0, 0);
13547 if (real_identical (&c, &cint))
13551 return tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 0),
13552 strict_overflow_p);
13559 /* ... fall through ... */
13562 if (truth_value_p (TREE_CODE (t)))
13563 /* Truth values evaluate to 0 or 1, which is nonnegative. */
13567 /* We don't know sign of `t', so be conservative and return false. */
13571 /* Return true if `t' is known to be non-negative. Handle warnings
13572 about undefined signed overflow. */
13575 tree_expr_nonnegative_p (tree t)
13577 bool ret, strict_overflow_p;
13579 strict_overflow_p = false;
13580 ret = tree_expr_nonnegative_warnv_p (t, &strict_overflow_p);
13581 if (strict_overflow_p)
13582 fold_overflow_warning (("assuming signed overflow does not occur when "
13583 "determining that expression is always "
13585 WARN_STRICT_OVERFLOW_MISC);
13589 /* Return true when T is an address and is known to be nonzero.
13590 For floating point we further ensure that T is not denormal.
13591 Similar logic is present in nonzero_address in rtlanal.h.
13593 If the return value is based on the assumption that signed overflow
13594 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
13595 change *STRICT_OVERFLOW_P. */
13598 tree_expr_nonzero_warnv_p (tree t, bool *strict_overflow_p)
13600 tree type = TREE_TYPE (t);
13601 bool sub_strict_overflow_p;
13603 /* Doing something useful for floating point would need more work. */
13604 if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
13607 switch (TREE_CODE (t))
13610 /* Query VRP to see if it has recorded any information about
13611 the range of this object. */
13612 return ssa_name_nonzero_p (t);
13615 return tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
13616 strict_overflow_p);
13619 return !integer_zerop (t);
13622 if (TYPE_OVERFLOW_UNDEFINED (type))
13624 /* With the presence of negative values it is hard
13625 to say something. */
13626 sub_strict_overflow_p = false;
13627 if (!tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
13628 &sub_strict_overflow_p)
13629 || !tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
13630 &sub_strict_overflow_p))
13632 /* One of operands must be positive and the other non-negative. */
13633 /* We don't set *STRICT_OVERFLOW_P here: even if this value
13634 overflows, on a twos-complement machine the sum of two
13635 nonnegative numbers can never be zero. */
13636 return (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
13638 || tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
13639 strict_overflow_p));
13644 if (TYPE_OVERFLOW_UNDEFINED (type))
13646 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
13648 && tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
13649 strict_overflow_p))
13651 *strict_overflow_p = true;
13659 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
13660 tree outer_type = TREE_TYPE (t);
13662 return (TYPE_PRECISION (outer_type) >= TYPE_PRECISION (inner_type)
13663 && tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
13664 strict_overflow_p));
13670 tree base = get_base_address (TREE_OPERAND (t, 0));
13675 /* Weak declarations may link to NULL. */
13676 if (VAR_OR_FUNCTION_DECL_P (base))
13677 return !DECL_WEAK (base);
13679 /* Constants are never weak. */
13680 if (CONSTANT_CLASS_P (base))
13687 sub_strict_overflow_p = false;
13688 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
13689 &sub_strict_overflow_p)
13690 && tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 2),
13691 &sub_strict_overflow_p))
13693 if (sub_strict_overflow_p)
13694 *strict_overflow_p = true;
13700 sub_strict_overflow_p = false;
13701 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
13702 &sub_strict_overflow_p)
13703 && tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
13704 &sub_strict_overflow_p))
13706 if (sub_strict_overflow_p)
13707 *strict_overflow_p = true;
13712 sub_strict_overflow_p = false;
13713 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
13714 &sub_strict_overflow_p))
13716 if (sub_strict_overflow_p)
13717 *strict_overflow_p = true;
13719 /* When both operands are nonzero, then MAX must be too. */
13720 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
13721 strict_overflow_p))
13724 /* MAX where operand 0 is positive is positive. */
13725 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
13726 strict_overflow_p);
13728 /* MAX where operand 1 is positive is positive. */
13729 else if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
13730 &sub_strict_overflow_p)
13731 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
13732 &sub_strict_overflow_p))
13734 if (sub_strict_overflow_p)
13735 *strict_overflow_p = true;
13740 case COMPOUND_EXPR:
13742 case GIMPLE_MODIFY_STMT:
13744 return tree_expr_nonzero_warnv_p (GENERIC_TREE_OPERAND (t, 1),
13745 strict_overflow_p);
13748 case NON_LVALUE_EXPR:
13749 return tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
13750 strict_overflow_p);
13753 return (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
13755 || tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
13756 strict_overflow_p));
13759 return alloca_call_p (t);
13767 /* Return true when T is an address and is known to be nonzero.
13768 Handle warnings about undefined signed overflow. */
13771 tree_expr_nonzero_p (tree t)
13773 bool ret, strict_overflow_p;
13775 strict_overflow_p = false;
13776 ret = tree_expr_nonzero_warnv_p (t, &strict_overflow_p);
13777 if (strict_overflow_p)
13778 fold_overflow_warning (("assuming signed overflow does not occur when "
13779 "determining that expression is always "
13781 WARN_STRICT_OVERFLOW_MISC);
13785 /* Given the components of a binary expression CODE, TYPE, OP0 and OP1,
13786 attempt to fold the expression to a constant without modifying TYPE,
13789 If the expression could be simplified to a constant, then return
13790 the constant. If the expression would not be simplified to a
13791 constant, then return NULL_TREE. */
13794 fold_binary_to_constant (enum tree_code code, tree type, tree op0, tree op1)
13796 tree tem = fold_binary (code, type, op0, op1);
13797 return (tem && TREE_CONSTANT (tem)) ? tem : NULL_TREE;
13800 /* Given the components of a unary expression CODE, TYPE and OP0,
13801 attempt to fold the expression to a constant without modifying
13804 If the expression could be simplified to a constant, then return
13805 the constant. If the expression would not be simplified to a
13806 constant, then return NULL_TREE. */
13809 fold_unary_to_constant (enum tree_code code, tree type, tree op0)
13811 tree tem = fold_unary (code, type, op0);
13812 return (tem && TREE_CONSTANT (tem)) ? tem : NULL_TREE;
13815 /* If EXP represents referencing an element in a constant string
13816 (either via pointer arithmetic or array indexing), return the
13817 tree representing the value accessed, otherwise return NULL. */
13820 fold_read_from_constant_string (tree exp)
13822 if ((TREE_CODE (exp) == INDIRECT_REF
13823 || TREE_CODE (exp) == ARRAY_REF)
13824 && TREE_CODE (TREE_TYPE (exp)) == INTEGER_TYPE)
13826 tree exp1 = TREE_OPERAND (exp, 0);
13830 if (TREE_CODE (exp) == INDIRECT_REF)
13831 string = string_constant (exp1, &index);
13834 tree low_bound = array_ref_low_bound (exp);
13835 index = fold_convert (sizetype, TREE_OPERAND (exp, 1));
13837 /* Optimize the special-case of a zero lower bound.
13839 We convert the low_bound to sizetype to avoid some problems
13840 with constant folding. (E.g. suppose the lower bound is 1,
13841 and its mode is QI. Without the conversion,l (ARRAY
13842 +(INDEX-(unsigned char)1)) becomes ((ARRAY+(-(unsigned char)1))
13843 +INDEX), which becomes (ARRAY+255+INDEX). Opps!) */
13844 if (! integer_zerop (low_bound))
13845 index = size_diffop (index, fold_convert (sizetype, low_bound));
13851 && TYPE_MODE (TREE_TYPE (exp)) == TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))
13852 && TREE_CODE (string) == STRING_CST
13853 && TREE_CODE (index) == INTEGER_CST
13854 && compare_tree_int (index, TREE_STRING_LENGTH (string)) < 0
13855 && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (string))))
13857 && (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))) == 1))
13858 return fold_convert (TREE_TYPE (exp),
13859 build_int_cst (NULL_TREE,
13860 (TREE_STRING_POINTER (string)
13861 [TREE_INT_CST_LOW (index)])));
13866 /* Return the tree for neg (ARG0) when ARG0 is known to be either
13867 an integer constant or real constant.
13869 TYPE is the type of the result. */
13872 fold_negate_const (tree arg0, tree type)
13874 tree t = NULL_TREE;
13876 switch (TREE_CODE (arg0))
13880 unsigned HOST_WIDE_INT low;
13881 HOST_WIDE_INT high;
13882 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
13883 TREE_INT_CST_HIGH (arg0),
13885 t = force_fit_type_double (type, low, high, 1,
13886 (overflow | TREE_OVERFLOW (arg0))
13887 && !TYPE_UNSIGNED (type));
13892 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
13896 gcc_unreachable ();
13902 /* Return the tree for abs (ARG0) when ARG0 is known to be either
13903 an integer constant or real constant.
13905 TYPE is the type of the result. */
13908 fold_abs_const (tree arg0, tree type)
13910 tree t = NULL_TREE;
13912 switch (TREE_CODE (arg0))
13915 /* If the value is unsigned, then the absolute value is
13916 the same as the ordinary value. */
13917 if (TYPE_UNSIGNED (type))
13919 /* Similarly, if the value is non-negative. */
13920 else if (INT_CST_LT (integer_minus_one_node, arg0))
13922 /* If the value is negative, then the absolute value is
13926 unsigned HOST_WIDE_INT low;
13927 HOST_WIDE_INT high;
13928 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
13929 TREE_INT_CST_HIGH (arg0),
13931 t = force_fit_type_double (type, low, high, -1,
13932 overflow | TREE_OVERFLOW (arg0));
13937 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
13938 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
13944 gcc_unreachable ();
13950 /* Return the tree for not (ARG0) when ARG0 is known to be an integer
13951 constant. TYPE is the type of the result. */
13954 fold_not_const (tree arg0, tree type)
13956 tree t = NULL_TREE;
13958 gcc_assert (TREE_CODE (arg0) == INTEGER_CST);
13960 t = force_fit_type_double (type, ~TREE_INT_CST_LOW (arg0),
13961 ~TREE_INT_CST_HIGH (arg0), 0,
13962 TREE_OVERFLOW (arg0));
13967 /* Given CODE, a relational operator, the target type, TYPE and two
13968 constant operands OP0 and OP1, return the result of the
13969 relational operation. If the result is not a compile time
13970 constant, then return NULL_TREE. */
13973 fold_relational_const (enum tree_code code, tree type, tree op0, tree op1)
13975 int result, invert;
13977 /* From here on, the only cases we handle are when the result is
13978 known to be a constant. */
13980 if (TREE_CODE (op0) == REAL_CST && TREE_CODE (op1) == REAL_CST)
13982 const REAL_VALUE_TYPE *c0 = TREE_REAL_CST_PTR (op0);
13983 const REAL_VALUE_TYPE *c1 = TREE_REAL_CST_PTR (op1);
13985 /* Handle the cases where either operand is a NaN. */
13986 if (real_isnan (c0) || real_isnan (c1))
13996 case UNORDERED_EXPR:
14010 if (flag_trapping_math)
14016 gcc_unreachable ();
14019 return constant_boolean_node (result, type);
14022 return constant_boolean_node (real_compare (code, c0, c1), type);
14025 /* Handle equality/inequality of complex constants. */
14026 if (TREE_CODE (op0) == COMPLEX_CST && TREE_CODE (op1) == COMPLEX_CST)
14028 tree rcond = fold_relational_const (code, type,
14029 TREE_REALPART (op0),
14030 TREE_REALPART (op1));
14031 tree icond = fold_relational_const (code, type,
14032 TREE_IMAGPART (op0),
14033 TREE_IMAGPART (op1));
14034 if (code == EQ_EXPR)
14035 return fold_build2 (TRUTH_ANDIF_EXPR, type, rcond, icond);
14036 else if (code == NE_EXPR)
14037 return fold_build2 (TRUTH_ORIF_EXPR, type, rcond, icond);
14042 /* From here on we only handle LT, LE, GT, GE, EQ and NE.
14044 To compute GT, swap the arguments and do LT.
14045 To compute GE, do LT and invert the result.
14046 To compute LE, swap the arguments, do LT and invert the result.
14047 To compute NE, do EQ and invert the result.
14049 Therefore, the code below must handle only EQ and LT. */
14051 if (code == LE_EXPR || code == GT_EXPR)
14056 code = swap_tree_comparison (code);
14059 /* Note that it is safe to invert for real values here because we
14060 have already handled the one case that it matters. */
14063 if (code == NE_EXPR || code == GE_EXPR)
14066 code = invert_tree_comparison (code, false);
14069 /* Compute a result for LT or EQ if args permit;
14070 Otherwise return T. */
14071 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
14073 if (code == EQ_EXPR)
14074 result = tree_int_cst_equal (op0, op1);
14075 else if (TYPE_UNSIGNED (TREE_TYPE (op0)))
14076 result = INT_CST_LT_UNSIGNED (op0, op1);
14078 result = INT_CST_LT (op0, op1);
14085 return constant_boolean_node (result, type);
14088 /* Build an expression for the a clean point containing EXPR with type TYPE.
14089 Don't build a cleanup point expression for EXPR which don't have side
14093 fold_build_cleanup_point_expr (tree type, tree expr)
14095 /* If the expression does not have side effects then we don't have to wrap
14096 it with a cleanup point expression. */
14097 if (!TREE_SIDE_EFFECTS (expr))
14100 /* If the expression is a return, check to see if the expression inside the
14101 return has no side effects or the right hand side of the modify expression
14102 inside the return. If either don't have side effects set we don't need to
14103 wrap the expression in a cleanup point expression. Note we don't check the
14104 left hand side of the modify because it should always be a return decl. */
14105 if (TREE_CODE (expr) == RETURN_EXPR)
14107 tree op = TREE_OPERAND (expr, 0);
14108 if (!op || !TREE_SIDE_EFFECTS (op))
14110 op = TREE_OPERAND (op, 1);
14111 if (!TREE_SIDE_EFFECTS (op))
14115 return build1 (CLEANUP_POINT_EXPR, type, expr);
14118 /* Build an expression for the address of T. Folds away INDIRECT_REF to
14119 avoid confusing the gimplify process. */
14122 build_fold_addr_expr_with_type (tree t, tree ptrtype)
14124 /* The size of the object is not relevant when talking about its address. */
14125 if (TREE_CODE (t) == WITH_SIZE_EXPR)
14126 t = TREE_OPERAND (t, 0);
14128 /* Note: doesn't apply to ALIGN_INDIRECT_REF */
14129 if (TREE_CODE (t) == INDIRECT_REF
14130 || TREE_CODE (t) == MISALIGNED_INDIRECT_REF)
14132 t = TREE_OPERAND (t, 0);
14133 if (TREE_TYPE (t) != ptrtype)
14134 t = build1 (NOP_EXPR, ptrtype, t);
14140 while (handled_component_p (base))
14141 base = TREE_OPERAND (base, 0);
14143 TREE_ADDRESSABLE (base) = 1;
14145 t = build1 (ADDR_EXPR, ptrtype, t);
14152 build_fold_addr_expr (tree t)
14154 return build_fold_addr_expr_with_type (t, build_pointer_type (TREE_TYPE (t)));
14157 /* Given a pointer value OP0 and a type TYPE, return a simplified version
14158 of an indirection through OP0, or NULL_TREE if no simplification is
14162 fold_indirect_ref_1 (tree type, tree op0)
14168 subtype = TREE_TYPE (sub);
14169 if (!POINTER_TYPE_P (subtype))
14172 if (TREE_CODE (sub) == ADDR_EXPR)
14174 tree op = TREE_OPERAND (sub, 0);
14175 tree optype = TREE_TYPE (op);
14176 /* *&CONST_DECL -> to the value of the const decl. */
14177 if (TREE_CODE (op) == CONST_DECL)
14178 return DECL_INITIAL (op);
14179 /* *&p => p; make sure to handle *&"str"[cst] here. */
14180 if (type == optype)
14182 tree fop = fold_read_from_constant_string (op);
14188 /* *(foo *)&fooarray => fooarray[0] */
14189 else if (TREE_CODE (optype) == ARRAY_TYPE
14190 && type == TREE_TYPE (optype))
14192 tree type_domain = TYPE_DOMAIN (optype);
14193 tree min_val = size_zero_node;
14194 if (type_domain && TYPE_MIN_VALUE (type_domain))
14195 min_val = TYPE_MIN_VALUE (type_domain);
14196 return build4 (ARRAY_REF, type, op, min_val, NULL_TREE, NULL_TREE);
14198 /* *(foo *)&complexfoo => __real__ complexfoo */
14199 else if (TREE_CODE (optype) == COMPLEX_TYPE
14200 && type == TREE_TYPE (optype))
14201 return fold_build1 (REALPART_EXPR, type, op);
14202 /* *(foo *)&vectorfoo => BIT_FIELD_REF<vectorfoo,...> */
14203 else if (TREE_CODE (optype) == VECTOR_TYPE
14204 && type == TREE_TYPE (optype))
14206 tree part_width = TYPE_SIZE (type);
14207 tree index = bitsize_int (0);
14208 return fold_build3 (BIT_FIELD_REF, type, op, part_width, index);
14212 /* ((foo*)&complexfoo)[1] => __imag__ complexfoo */
14213 if (TREE_CODE (sub) == PLUS_EXPR
14214 && TREE_CODE (TREE_OPERAND (sub, 1)) == INTEGER_CST)
14216 tree op00 = TREE_OPERAND (sub, 0);
14217 tree op01 = TREE_OPERAND (sub, 1);
14221 op00type = TREE_TYPE (op00);
14222 if (TREE_CODE (op00) == ADDR_EXPR
14223 && TREE_CODE (TREE_TYPE (op00type)) == COMPLEX_TYPE
14224 && type == TREE_TYPE (TREE_TYPE (op00type)))
14226 tree size = TYPE_SIZE_UNIT (type);
14227 if (tree_int_cst_equal (size, op01))
14228 return fold_build1 (IMAGPART_EXPR, type, TREE_OPERAND (op00, 0));
14232 /* *(foo *)fooarrptr => (*fooarrptr)[0] */
14233 if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE
14234 && type == TREE_TYPE (TREE_TYPE (subtype)))
14237 tree min_val = size_zero_node;
14238 sub = build_fold_indirect_ref (sub);
14239 type_domain = TYPE_DOMAIN (TREE_TYPE (sub));
14240 if (type_domain && TYPE_MIN_VALUE (type_domain))
14241 min_val = TYPE_MIN_VALUE (type_domain);
14242 return build4 (ARRAY_REF, type, sub, min_val, NULL_TREE, NULL_TREE);
14248 /* Builds an expression for an indirection through T, simplifying some
14252 build_fold_indirect_ref (tree t)
14254 tree type = TREE_TYPE (TREE_TYPE (t));
14255 tree sub = fold_indirect_ref_1 (type, t);
14260 return build1 (INDIRECT_REF, type, t);
14263 /* Given an INDIRECT_REF T, return either T or a simplified version. */
14266 fold_indirect_ref (tree t)
14268 tree sub = fold_indirect_ref_1 (TREE_TYPE (t), TREE_OPERAND (t, 0));
14276 /* Strip non-trapping, non-side-effecting tree nodes from an expression
14277 whose result is ignored. The type of the returned tree need not be
14278 the same as the original expression. */
14281 fold_ignored_result (tree t)
14283 if (!TREE_SIDE_EFFECTS (t))
14284 return integer_zero_node;
14287 switch (TREE_CODE_CLASS (TREE_CODE (t)))
14290 t = TREE_OPERAND (t, 0);
14294 case tcc_comparison:
14295 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
14296 t = TREE_OPERAND (t, 0);
14297 else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0)))
14298 t = TREE_OPERAND (t, 1);
14303 case tcc_expression:
14304 switch (TREE_CODE (t))
14306 case COMPOUND_EXPR:
14307 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
14309 t = TREE_OPERAND (t, 0);
14313 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1))
14314 || TREE_SIDE_EFFECTS (TREE_OPERAND (t, 2)))
14316 t = TREE_OPERAND (t, 0);
14329 /* Return the value of VALUE, rounded up to a multiple of DIVISOR.
14330 This can only be applied to objects of a sizetype. */
14333 round_up (tree value, int divisor)
14335 tree div = NULL_TREE;
14337 gcc_assert (divisor > 0);
14341 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
14342 have to do anything. Only do this when we are not given a const,
14343 because in that case, this check is more expensive than just
14345 if (TREE_CODE (value) != INTEGER_CST)
14347 div = build_int_cst (TREE_TYPE (value), divisor);
14349 if (multiple_of_p (TREE_TYPE (value), value, div))
14353 /* If divisor is a power of two, simplify this to bit manipulation. */
14354 if (divisor == (divisor & -divisor))
14356 if (TREE_CODE (value) == INTEGER_CST)
14358 unsigned HOST_WIDE_INT low = TREE_INT_CST_LOW (value);
14359 unsigned HOST_WIDE_INT high;
14362 if ((low & (divisor - 1)) == 0)
14365 overflow_p = TREE_OVERFLOW (value);
14366 high = TREE_INT_CST_HIGH (value);
14367 low &= ~(divisor - 1);
14376 return force_fit_type_double (TREE_TYPE (value), low, high,
14383 t = build_int_cst (TREE_TYPE (value), divisor - 1);
14384 value = size_binop (PLUS_EXPR, value, t);
14385 t = build_int_cst (TREE_TYPE (value), -divisor);
14386 value = size_binop (BIT_AND_EXPR, value, t);
14392 div = build_int_cst (TREE_TYPE (value), divisor);
14393 value = size_binop (CEIL_DIV_EXPR, value, div);
14394 value = size_binop (MULT_EXPR, value, div);
14400 /* Likewise, but round down. */
14403 round_down (tree value, int divisor)
14405 tree div = NULL_TREE;
14407 gcc_assert (divisor > 0);
14411 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
14412 have to do anything. Only do this when we are not given a const,
14413 because in that case, this check is more expensive than just
14415 if (TREE_CODE (value) != INTEGER_CST)
14417 div = build_int_cst (TREE_TYPE (value), divisor);
14419 if (multiple_of_p (TREE_TYPE (value), value, div))
14423 /* If divisor is a power of two, simplify this to bit manipulation. */
14424 if (divisor == (divisor & -divisor))
14428 t = build_int_cst (TREE_TYPE (value), -divisor);
14429 value = size_binop (BIT_AND_EXPR, value, t);
14434 div = build_int_cst (TREE_TYPE (value), divisor);
14435 value = size_binop (FLOOR_DIV_EXPR, value, div);
14436 value = size_binop (MULT_EXPR, value, div);
14442 /* Returns the pointer to the base of the object addressed by EXP and
14443 extracts the information about the offset of the access, storing it
14444 to PBITPOS and POFFSET. */
14447 split_address_to_core_and_offset (tree exp,
14448 HOST_WIDE_INT *pbitpos, tree *poffset)
14451 enum machine_mode mode;
14452 int unsignedp, volatilep;
14453 HOST_WIDE_INT bitsize;
14455 if (TREE_CODE (exp) == ADDR_EXPR)
14457 core = get_inner_reference (TREE_OPERAND (exp, 0), &bitsize, pbitpos,
14458 poffset, &mode, &unsignedp, &volatilep,
14460 core = build_fold_addr_expr (core);
14466 *poffset = NULL_TREE;
14472 /* Returns true if addresses of E1 and E2 differ by a constant, false
14473 otherwise. If they do, E1 - E2 is stored in *DIFF. */
14476 ptr_difference_const (tree e1, tree e2, HOST_WIDE_INT *diff)
14479 HOST_WIDE_INT bitpos1, bitpos2;
14480 tree toffset1, toffset2, tdiff, type;
14482 core1 = split_address_to_core_and_offset (e1, &bitpos1, &toffset1);
14483 core2 = split_address_to_core_and_offset (e2, &bitpos2, &toffset2);
14485 if (bitpos1 % BITS_PER_UNIT != 0
14486 || bitpos2 % BITS_PER_UNIT != 0
14487 || !operand_equal_p (core1, core2, 0))
14490 if (toffset1 && toffset2)
14492 type = TREE_TYPE (toffset1);
14493 if (type != TREE_TYPE (toffset2))
14494 toffset2 = fold_convert (type, toffset2);
14496 tdiff = fold_build2 (MINUS_EXPR, type, toffset1, toffset2);
14497 if (!cst_and_fits_in_hwi (tdiff))
14500 *diff = int_cst_value (tdiff);
14502 else if (toffset1 || toffset2)
14504 /* If only one of the offsets is non-constant, the difference cannot
14511 *diff += (bitpos1 - bitpos2) / BITS_PER_UNIT;
14515 /* Simplify the floating point expression EXP when the sign of the
14516 result is not significant. Return NULL_TREE if no simplification
14520 fold_strip_sign_ops (tree exp)
14524 switch (TREE_CODE (exp))
14528 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
14529 return arg0 ? arg0 : TREE_OPERAND (exp, 0);
14533 if (HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (exp))))
14535 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
14536 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
14537 if (arg0 != NULL_TREE || arg1 != NULL_TREE)
14538 return fold_build2 (TREE_CODE (exp), TREE_TYPE (exp),
14539 arg0 ? arg0 : TREE_OPERAND (exp, 0),
14540 arg1 ? arg1 : TREE_OPERAND (exp, 1));
14543 case COMPOUND_EXPR:
14544 arg0 = TREE_OPERAND (exp, 0);
14545 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
14547 return fold_build2 (COMPOUND_EXPR, TREE_TYPE (exp), arg0, arg1);
14551 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
14552 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 2));
14554 return fold_build3 (COND_EXPR, TREE_TYPE (exp), TREE_OPERAND (exp, 0),
14555 arg0 ? arg0 : TREE_OPERAND (exp, 1),
14556 arg1 ? arg1 : TREE_OPERAND (exp, 2));
14561 const enum built_in_function fcode = builtin_mathfn_code (exp);
14564 CASE_FLT_FN (BUILT_IN_COPYSIGN):
14565 /* Strip copysign function call, return the 1st argument. */
14566 arg0 = CALL_EXPR_ARG (exp, 0);
14567 arg1 = CALL_EXPR_ARG (exp, 1);
14568 return omit_one_operand (TREE_TYPE (exp), arg0, arg1);
14571 /* Strip sign ops from the argument of "odd" math functions. */
14572 if (negate_mathfn_p (fcode))
14574 arg0 = fold_strip_sign_ops (CALL_EXPR_ARG (exp, 0));
14576 return build_call_expr (get_callee_fndecl (exp), 1, arg0);