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 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
22 /*@@ This file should be rewritten to use an arbitrary precision
23 @@ representation for "struct tree_int_cst" and "struct tree_real_cst".
24 @@ Perhaps the routines could also be used for bc/dc, and made a lib.
25 @@ The routines that translate from the ap rep should
26 @@ warn if precision et. al. is lost.
27 @@ This would also make life easier when this technology is used
28 @@ for cross-compilers. */
30 /* The entry points in this file are fold, size_int_wide, size_binop
33 fold takes a tree as argument and returns a simplified tree.
35 size_binop takes a tree code for an arithmetic operation
36 and two operands that are trees, and produces a tree for the
37 result, assuming the type comes from `sizetype'.
39 size_int takes an integer value, and creates a tree constant
40 with type from `sizetype'.
42 force_fit_type takes a constant, an overflowable flag and prior
43 overflow indicators. It forces the value to fit the type and sets
44 TREE_OVERFLOW and TREE_CONSTANT_OVERFLOW as appropriate. */
48 #include "coretypes.h"
59 #include "langhooks.h"
62 /* The following constants represent a bit based encoding of GCC's
63 comparison operators. This encoding simplifies transformations
64 on relational comparison operators, such as AND and OR. */
65 enum comparison_code {
84 static void encode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT, HOST_WIDE_INT);
85 static void decode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
86 static bool negate_mathfn_p (enum built_in_function);
87 static bool negate_expr_p (tree);
88 static tree negate_expr (tree);
89 static tree split_tree (tree, enum tree_code, tree *, tree *, tree *, int);
90 static tree associate_trees (tree, tree, enum tree_code, tree);
91 static tree const_binop (enum tree_code, tree, tree, int);
92 static enum tree_code invert_tree_comparison (enum tree_code, bool);
93 static enum comparison_code comparison_to_compcode (enum tree_code);
94 static enum tree_code compcode_to_comparison (enum comparison_code);
95 static tree combine_comparisons (enum tree_code, enum tree_code,
96 enum tree_code, tree, tree, tree);
97 static int truth_value_p (enum tree_code);
98 static int operand_equal_for_comparison_p (tree, tree, tree);
99 static int twoval_comparison_p (tree, tree *, tree *, int *);
100 static tree eval_subst (tree, tree, tree, tree, tree);
101 static tree pedantic_omit_one_operand (tree, tree, tree);
102 static tree distribute_bit_expr (enum tree_code, tree, tree, tree);
103 static tree make_bit_field_ref (tree, tree, int, int, int);
104 static tree optimize_bit_field_compare (enum tree_code, tree, tree, tree);
105 static tree decode_field_reference (tree, HOST_WIDE_INT *, HOST_WIDE_INT *,
106 enum machine_mode *, int *, int *,
108 static int all_ones_mask_p (tree, int);
109 static tree sign_bit_p (tree, tree);
110 static int simple_operand_p (tree);
111 static tree range_binop (enum tree_code, tree, tree, int, tree, int);
112 static tree make_range (tree, int *, tree *, tree *);
113 static tree build_range_check (tree, tree, int, tree, tree);
114 static int merge_ranges (int *, tree *, tree *, int, tree, tree, int, tree,
116 static tree fold_range_test (tree);
117 static tree fold_cond_expr_with_comparison (tree, tree, tree, tree);
118 static tree unextend (tree, int, int, tree);
119 static tree fold_truthop (enum tree_code, tree, tree, tree);
120 static tree optimize_minmax_comparison (tree);
121 static tree extract_muldiv (tree, tree, enum tree_code, tree);
122 static tree extract_muldiv_1 (tree, tree, enum tree_code, tree);
123 static int multiple_of_p (tree, tree, tree);
124 static tree fold_binary_op_with_conditional_arg (tree, enum tree_code,
126 static bool fold_real_zero_addition_p (tree, tree, int);
127 static tree fold_mathfn_compare (enum built_in_function, enum tree_code,
129 static tree fold_inf_compare (enum tree_code, tree, tree, tree);
130 static tree fold_div_compare (enum tree_code, tree, tree, tree);
131 static bool reorder_operands_p (tree, tree);
132 static tree fold_negate_const (tree, tree);
133 static tree fold_not_const (tree, tree);
134 static tree fold_relational_const (enum tree_code, tree, tree, tree);
135 static tree fold_relational_hi_lo (enum tree_code *, const tree,
137 static bool tree_expr_nonzero_p (tree);
139 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
140 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
141 and SUM1. Then this yields nonzero if overflow occurred during the
144 Overflow occurs if A and B have the same sign, but A and SUM differ in
145 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
147 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
149 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
150 We do that by representing the two-word integer in 4 words, with only
151 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
152 number. The value of the word is LOWPART + HIGHPART * BASE. */
155 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
156 #define HIGHPART(x) \
157 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
158 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
160 /* Unpack a two-word integer into 4 words.
161 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
162 WORDS points to the array of HOST_WIDE_INTs. */
165 encode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT low, HOST_WIDE_INT hi)
167 words[0] = LOWPART (low);
168 words[1] = HIGHPART (low);
169 words[2] = LOWPART (hi);
170 words[3] = HIGHPART (hi);
173 /* Pack an array of 4 words into a two-word integer.
174 WORDS points to the array of words.
175 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
178 decode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT *low,
181 *low = words[0] + words[1] * BASE;
182 *hi = words[2] + words[3] * BASE;
185 /* T is an INT_CST node. OVERFLOWABLE indicates if we are interested
186 in overflow of the value, when >0 we are only interested in signed
187 overflow, for <0 we are interested in any overflow. OVERFLOWED
188 indicates whether overflow has already occurred. CONST_OVERFLOWED
189 indicates whether constant overflow has already occurred. We force
190 T's value to be within range of T's type (by setting to 0 or 1 all
191 the bits outside the type's range). We set TREE_OVERFLOWED if,
192 OVERFLOWED is nonzero,
193 or OVERFLOWABLE is >0 and signed overflow occurs
194 or OVERFLOWABLE is <0 and any overflow occurs
195 We set TREE_CONSTANT_OVERFLOWED if,
196 CONST_OVERFLOWED is nonzero
197 or we set TREE_OVERFLOWED.
198 We return either the original T, or a copy. */
201 force_fit_type (tree t, int overflowable,
202 bool overflowed, bool overflowed_const)
204 unsigned HOST_WIDE_INT low;
207 int sign_extended_type;
209 gcc_assert (TREE_CODE (t) == INTEGER_CST);
211 low = TREE_INT_CST_LOW (t);
212 high = TREE_INT_CST_HIGH (t);
214 if (POINTER_TYPE_P (TREE_TYPE (t))
215 || TREE_CODE (TREE_TYPE (t)) == OFFSET_TYPE)
218 prec = TYPE_PRECISION (TREE_TYPE (t));
219 /* Size types *are* sign extended. */
220 sign_extended_type = (!TYPE_UNSIGNED (TREE_TYPE (t))
221 || (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
222 && TYPE_IS_SIZETYPE (TREE_TYPE (t))));
224 /* First clear all bits that are beyond the type's precision. */
226 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
228 else if (prec > HOST_BITS_PER_WIDE_INT)
229 high &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
233 if (prec < HOST_BITS_PER_WIDE_INT)
234 low &= ~((HOST_WIDE_INT) (-1) << prec);
237 if (!sign_extended_type)
238 /* No sign extension */;
239 else if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
240 /* Correct width already. */;
241 else if (prec > HOST_BITS_PER_WIDE_INT)
243 /* Sign extend top half? */
244 if (high & ((unsigned HOST_WIDE_INT)1
245 << (prec - HOST_BITS_PER_WIDE_INT - 1)))
246 high |= (HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT);
248 else if (prec == HOST_BITS_PER_WIDE_INT)
250 if ((HOST_WIDE_INT)low < 0)
255 /* Sign extend bottom half? */
256 if (low & ((unsigned HOST_WIDE_INT)1 << (prec - 1)))
259 low |= (HOST_WIDE_INT)(-1) << prec;
263 /* If the value changed, return a new node. */
264 if (overflowed || overflowed_const
265 || low != TREE_INT_CST_LOW (t) || high != TREE_INT_CST_HIGH (t))
267 t = build_int_cst_wide (TREE_TYPE (t), low, high);
271 || (overflowable > 0 && sign_extended_type))
274 TREE_OVERFLOW (t) = 1;
275 TREE_CONSTANT_OVERFLOW (t) = 1;
277 else if (overflowed_const)
280 TREE_CONSTANT_OVERFLOW (t) = 1;
287 /* Add two doubleword integers with doubleword result.
288 Each argument is given as two `HOST_WIDE_INT' pieces.
289 One argument is L1 and H1; the other, L2 and H2.
290 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
293 add_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
294 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
295 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
297 unsigned HOST_WIDE_INT l;
301 h = h1 + h2 + (l < l1);
305 return OVERFLOW_SUM_SIGN (h1, h2, h);
308 /* Negate a doubleword integer with doubleword result.
309 Return nonzero if the operation overflows, assuming it's signed.
310 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
311 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
314 neg_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
315 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
321 return (*hv & h1) < 0;
331 /* Multiply two doubleword integers with doubleword result.
332 Return nonzero if the operation overflows, assuming it's signed.
333 Each argument is given as two `HOST_WIDE_INT' pieces.
334 One argument is L1 and H1; the other, L2 and H2.
335 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
338 mul_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
339 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
340 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
342 HOST_WIDE_INT arg1[4];
343 HOST_WIDE_INT arg2[4];
344 HOST_WIDE_INT prod[4 * 2];
345 unsigned HOST_WIDE_INT carry;
347 unsigned HOST_WIDE_INT toplow, neglow;
348 HOST_WIDE_INT tophigh, neghigh;
350 encode (arg1, l1, h1);
351 encode (arg2, l2, h2);
353 memset (prod, 0, sizeof prod);
355 for (i = 0; i < 4; i++)
358 for (j = 0; j < 4; j++)
361 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
362 carry += arg1[i] * arg2[j];
363 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
365 prod[k] = LOWPART (carry);
366 carry = HIGHPART (carry);
371 decode (prod, lv, hv); /* This ignores prod[4] through prod[4*2-1] */
373 /* Check for overflow by calculating the top half of the answer in full;
374 it should agree with the low half's sign bit. */
375 decode (prod + 4, &toplow, &tophigh);
378 neg_double (l2, h2, &neglow, &neghigh);
379 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
383 neg_double (l1, h1, &neglow, &neghigh);
384 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
386 return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
389 /* Shift the doubleword integer in L1, H1 left by COUNT places
390 keeping only PREC bits of result.
391 Shift right if COUNT is negative.
392 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
393 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
396 lshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
397 HOST_WIDE_INT count, unsigned int prec,
398 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv, int arith)
400 unsigned HOST_WIDE_INT signmask;
404 rshift_double (l1, h1, -count, prec, lv, hv, arith);
408 if (SHIFT_COUNT_TRUNCATED)
411 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
413 /* Shifting by the host word size is undefined according to the
414 ANSI standard, so we must handle this as a special case. */
418 else if (count >= HOST_BITS_PER_WIDE_INT)
420 *hv = l1 << (count - HOST_BITS_PER_WIDE_INT);
425 *hv = (((unsigned HOST_WIDE_INT) h1 << count)
426 | (l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
430 /* Sign extend all bits that are beyond the precision. */
432 signmask = -((prec > HOST_BITS_PER_WIDE_INT
433 ? ((unsigned HOST_WIDE_INT) *hv
434 >> (prec - HOST_BITS_PER_WIDE_INT - 1))
435 : (*lv >> (prec - 1))) & 1);
437 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
439 else if (prec >= HOST_BITS_PER_WIDE_INT)
441 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
442 *hv |= signmask << (prec - HOST_BITS_PER_WIDE_INT);
447 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
448 *lv |= signmask << prec;
452 /* Shift the doubleword integer in L1, H1 right by COUNT places
453 keeping only PREC bits of result. COUNT must be positive.
454 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
455 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
458 rshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
459 HOST_WIDE_INT count, unsigned int prec,
460 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
463 unsigned HOST_WIDE_INT signmask;
466 ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
469 if (SHIFT_COUNT_TRUNCATED)
472 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
474 /* Shifting by the host word size is undefined according to the
475 ANSI standard, so we must handle this as a special case. */
479 else if (count >= HOST_BITS_PER_WIDE_INT)
482 *lv = (unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT);
486 *hv = (unsigned HOST_WIDE_INT) h1 >> count;
488 | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
491 /* Zero / sign extend all bits that are beyond the precision. */
493 if (count >= (HOST_WIDE_INT)prec)
498 else if ((prec - count) >= 2 * HOST_BITS_PER_WIDE_INT)
500 else if ((prec - count) >= HOST_BITS_PER_WIDE_INT)
502 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - count - HOST_BITS_PER_WIDE_INT));
503 *hv |= signmask << (prec - count - HOST_BITS_PER_WIDE_INT);
508 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << (prec - count));
509 *lv |= signmask << (prec - count);
513 /* Rotate the doubleword integer in L1, H1 left by COUNT places
514 keeping only PREC bits of result.
515 Rotate right if COUNT is negative.
516 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
519 lrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
520 HOST_WIDE_INT count, unsigned int prec,
521 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
523 unsigned HOST_WIDE_INT s1l, s2l;
524 HOST_WIDE_INT s1h, s2h;
530 lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
531 rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
536 /* Rotate the doubleword integer in L1, H1 left by COUNT places
537 keeping only PREC bits of result. COUNT must be positive.
538 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
541 rrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
542 HOST_WIDE_INT count, unsigned int prec,
543 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
545 unsigned HOST_WIDE_INT s1l, s2l;
546 HOST_WIDE_INT s1h, s2h;
552 rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
553 lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
558 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
559 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
560 CODE is a tree code for a kind of division, one of
561 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
563 It controls how the quotient is rounded to an integer.
564 Return nonzero if the operation overflows.
565 UNS nonzero says do unsigned division. */
568 div_and_round_double (enum tree_code code, int uns,
569 unsigned HOST_WIDE_INT lnum_orig, /* num == numerator == dividend */
570 HOST_WIDE_INT hnum_orig,
571 unsigned HOST_WIDE_INT lden_orig, /* den == denominator == divisor */
572 HOST_WIDE_INT hden_orig,
573 unsigned HOST_WIDE_INT *lquo,
574 HOST_WIDE_INT *hquo, unsigned HOST_WIDE_INT *lrem,
578 HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
579 HOST_WIDE_INT den[4], quo[4];
581 unsigned HOST_WIDE_INT work;
582 unsigned HOST_WIDE_INT carry = 0;
583 unsigned HOST_WIDE_INT lnum = lnum_orig;
584 HOST_WIDE_INT hnum = hnum_orig;
585 unsigned HOST_WIDE_INT lden = lden_orig;
586 HOST_WIDE_INT hden = hden_orig;
589 if (hden == 0 && lden == 0)
590 overflow = 1, lden = 1;
592 /* Calculate quotient sign and convert operands to unsigned. */
598 /* (minimum integer) / (-1) is the only overflow case. */
599 if (neg_double (lnum, hnum, &lnum, &hnum)
600 && ((HOST_WIDE_INT) lden & hden) == -1)
606 neg_double (lden, hden, &lden, &hden);
610 if (hnum == 0 && hden == 0)
611 { /* single precision */
613 /* This unsigned division rounds toward zero. */
619 { /* trivial case: dividend < divisor */
620 /* hden != 0 already checked. */
627 memset (quo, 0, sizeof quo);
629 memset (num, 0, sizeof num); /* to zero 9th element */
630 memset (den, 0, sizeof den);
632 encode (num, lnum, hnum);
633 encode (den, lden, hden);
635 /* Special code for when the divisor < BASE. */
636 if (hden == 0 && lden < (unsigned HOST_WIDE_INT) BASE)
638 /* hnum != 0 already checked. */
639 for (i = 4 - 1; i >= 0; i--)
641 work = num[i] + carry * BASE;
642 quo[i] = work / lden;
648 /* Full double precision division,
649 with thanks to Don Knuth's "Seminumerical Algorithms". */
650 int num_hi_sig, den_hi_sig;
651 unsigned HOST_WIDE_INT quo_est, scale;
653 /* Find the highest nonzero divisor digit. */
654 for (i = 4 - 1;; i--)
661 /* Insure that the first digit of the divisor is at least BASE/2.
662 This is required by the quotient digit estimation algorithm. */
664 scale = BASE / (den[den_hi_sig] + 1);
666 { /* scale divisor and dividend */
668 for (i = 0; i <= 4 - 1; i++)
670 work = (num[i] * scale) + carry;
671 num[i] = LOWPART (work);
672 carry = HIGHPART (work);
677 for (i = 0; i <= 4 - 1; i++)
679 work = (den[i] * scale) + carry;
680 den[i] = LOWPART (work);
681 carry = HIGHPART (work);
682 if (den[i] != 0) den_hi_sig = i;
689 for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--)
691 /* Guess the next quotient digit, quo_est, by dividing the first
692 two remaining dividend digits by the high order quotient digit.
693 quo_est is never low and is at most 2 high. */
694 unsigned HOST_WIDE_INT tmp;
696 num_hi_sig = i + den_hi_sig + 1;
697 work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
698 if (num[num_hi_sig] != den[den_hi_sig])
699 quo_est = work / den[den_hi_sig];
703 /* Refine quo_est so it's usually correct, and at most one high. */
704 tmp = work - quo_est * den[den_hi_sig];
706 && (den[den_hi_sig - 1] * quo_est
707 > (tmp * BASE + num[num_hi_sig - 2])))
710 /* Try QUO_EST as the quotient digit, by multiplying the
711 divisor by QUO_EST and subtracting from the remaining dividend.
712 Keep in mind that QUO_EST is the I - 1st digit. */
715 for (j = 0; j <= den_hi_sig; j++)
717 work = quo_est * den[j] + carry;
718 carry = HIGHPART (work);
719 work = num[i + j] - LOWPART (work);
720 num[i + j] = LOWPART (work);
721 carry += HIGHPART (work) != 0;
724 /* If quo_est was high by one, then num[i] went negative and
725 we need to correct things. */
726 if (num[num_hi_sig] < (HOST_WIDE_INT) carry)
729 carry = 0; /* add divisor back in */
730 for (j = 0; j <= den_hi_sig; j++)
732 work = num[i + j] + den[j] + carry;
733 carry = HIGHPART (work);
734 num[i + j] = LOWPART (work);
737 num [num_hi_sig] += carry;
740 /* Store the quotient digit. */
745 decode (quo, lquo, hquo);
748 /* If result is negative, make it so. */
750 neg_double (*lquo, *hquo, lquo, hquo);
752 /* Compute trial remainder: rem = num - (quo * den) */
753 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
754 neg_double (*lrem, *hrem, lrem, hrem);
755 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
760 case TRUNC_MOD_EXPR: /* round toward zero */
761 case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
765 case FLOOR_MOD_EXPR: /* round toward negative infinity */
766 if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
769 add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
777 case CEIL_MOD_EXPR: /* round toward positive infinity */
778 if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
780 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
788 case ROUND_MOD_EXPR: /* round to closest integer */
790 unsigned HOST_WIDE_INT labs_rem = *lrem;
791 HOST_WIDE_INT habs_rem = *hrem;
792 unsigned HOST_WIDE_INT labs_den = lden, ltwice;
793 HOST_WIDE_INT habs_den = hden, htwice;
795 /* Get absolute values. */
797 neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
799 neg_double (lden, hden, &labs_den, &habs_den);
801 /* If (2 * abs (lrem) >= abs (lden)) */
802 mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
803 labs_rem, habs_rem, <wice, &htwice);
805 if (((unsigned HOST_WIDE_INT) habs_den
806 < (unsigned HOST_WIDE_INT) htwice)
807 || (((unsigned HOST_WIDE_INT) habs_den
808 == (unsigned HOST_WIDE_INT) htwice)
809 && (labs_den < ltwice)))
813 add_double (*lquo, *hquo,
814 (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
817 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
829 /* Compute true remainder: rem = num - (quo * den) */
830 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
831 neg_double (*lrem, *hrem, lrem, hrem);
832 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
836 /* Return true if built-in mathematical function specified by CODE
837 preserves the sign of it argument, i.e. -f(x) == f(-x). */
840 negate_mathfn_p (enum built_in_function code)
864 /* Check whether we may negate an integer constant T without causing
868 may_negate_without_overflow_p (tree t)
870 unsigned HOST_WIDE_INT val;
874 gcc_assert (TREE_CODE (t) == INTEGER_CST);
876 type = TREE_TYPE (t);
877 if (TYPE_UNSIGNED (type))
880 prec = TYPE_PRECISION (type);
881 if (prec > HOST_BITS_PER_WIDE_INT)
883 if (TREE_INT_CST_LOW (t) != 0)
885 prec -= HOST_BITS_PER_WIDE_INT;
886 val = TREE_INT_CST_HIGH (t);
889 val = TREE_INT_CST_LOW (t);
890 if (prec < HOST_BITS_PER_WIDE_INT)
891 val &= ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
892 return val != ((unsigned HOST_WIDE_INT) 1 << (prec - 1));
895 /* Determine whether an expression T can be cheaply negated using
896 the function negate_expr. */
899 negate_expr_p (tree t)
906 type = TREE_TYPE (t);
909 switch (TREE_CODE (t))
912 if (TYPE_UNSIGNED (type) || ! flag_trapv)
915 /* Check that -CST will not overflow type. */
916 return may_negate_without_overflow_p (t);
923 return negate_expr_p (TREE_REALPART (t))
924 && negate_expr_p (TREE_IMAGPART (t));
927 if (FLOAT_TYPE_P (type) && !flag_unsafe_math_optimizations)
929 /* -(A + B) -> (-B) - A. */
930 if (negate_expr_p (TREE_OPERAND (t, 1))
931 && reorder_operands_p (TREE_OPERAND (t, 0),
932 TREE_OPERAND (t, 1)))
934 /* -(A + B) -> (-A) - B. */
935 return negate_expr_p (TREE_OPERAND (t, 0));
938 /* We can't turn -(A-B) into B-A when we honor signed zeros. */
939 return (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
940 && reorder_operands_p (TREE_OPERAND (t, 0),
941 TREE_OPERAND (t, 1));
944 if (TYPE_UNSIGNED (TREE_TYPE (t)))
950 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
951 return negate_expr_p (TREE_OPERAND (t, 1))
952 || negate_expr_p (TREE_OPERAND (t, 0));
956 /* Negate -((double)float) as (double)(-float). */
957 if (TREE_CODE (type) == REAL_TYPE)
959 tree tem = strip_float_extensions (t);
961 return negate_expr_p (tem);
966 /* Negate -f(x) as f(-x). */
967 if (negate_mathfn_p (builtin_mathfn_code (t)))
968 return negate_expr_p (TREE_VALUE (TREE_OPERAND (t, 1)));
972 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
973 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
975 tree op1 = TREE_OPERAND (t, 1);
976 if (TREE_INT_CST_HIGH (op1) == 0
977 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
978 == TREE_INT_CST_LOW (op1))
989 /* Given T, an expression, return the negation of T. Allow for T to be
990 null, in which case return null. */
1001 type = TREE_TYPE (t);
1002 STRIP_SIGN_NOPS (t);
1004 switch (TREE_CODE (t))
1007 tem = fold_negate_const (t, type);
1008 if (! TREE_OVERFLOW (tem)
1009 || TYPE_UNSIGNED (type)
1015 tem = fold_negate_const (t, type);
1016 /* Two's complement FP formats, such as c4x, may overflow. */
1017 if (! TREE_OVERFLOW (tem) || ! flag_trapping_math)
1018 return fold_convert (type, tem);
1023 tree rpart = negate_expr (TREE_REALPART (t));
1024 tree ipart = negate_expr (TREE_IMAGPART (t));
1026 if ((TREE_CODE (rpart) == REAL_CST
1027 && TREE_CODE (ipart) == REAL_CST)
1028 || (TREE_CODE (rpart) == INTEGER_CST
1029 && TREE_CODE (ipart) == INTEGER_CST))
1030 return build_complex (type, rpart, ipart);
1035 return fold_convert (type, TREE_OPERAND (t, 0));
1038 if (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
1040 /* -(A + B) -> (-B) - A. */
1041 if (negate_expr_p (TREE_OPERAND (t, 1))
1042 && reorder_operands_p (TREE_OPERAND (t, 0),
1043 TREE_OPERAND (t, 1)))
1045 tem = negate_expr (TREE_OPERAND (t, 1));
1046 tem = fold (build2 (MINUS_EXPR, TREE_TYPE (t),
1047 tem, TREE_OPERAND (t, 0)));
1048 return fold_convert (type, tem);
1051 /* -(A + B) -> (-A) - B. */
1052 if (negate_expr_p (TREE_OPERAND (t, 0)))
1054 tem = negate_expr (TREE_OPERAND (t, 0));
1055 tem = fold (build2 (MINUS_EXPR, TREE_TYPE (t),
1056 tem, TREE_OPERAND (t, 1)));
1057 return fold_convert (type, tem);
1063 /* - (A - B) -> B - A */
1064 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
1065 && reorder_operands_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1)))
1066 return fold_convert (type,
1067 fold (build2 (MINUS_EXPR, TREE_TYPE (t),
1068 TREE_OPERAND (t, 1),
1069 TREE_OPERAND (t, 0))));
1073 if (TYPE_UNSIGNED (TREE_TYPE (t)))
1079 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
1081 tem = TREE_OPERAND (t, 1);
1082 if (negate_expr_p (tem))
1083 return fold_convert (type,
1084 fold (build2 (TREE_CODE (t), TREE_TYPE (t),
1085 TREE_OPERAND (t, 0),
1086 negate_expr (tem))));
1087 tem = TREE_OPERAND (t, 0);
1088 if (negate_expr_p (tem))
1089 return fold_convert (type,
1090 fold (build2 (TREE_CODE (t), TREE_TYPE (t),
1092 TREE_OPERAND (t, 1))));
1097 /* Convert -((double)float) into (double)(-float). */
1098 if (TREE_CODE (type) == REAL_TYPE)
1100 tem = strip_float_extensions (t);
1101 if (tem != t && negate_expr_p (tem))
1102 return fold_convert (type, negate_expr (tem));
1107 /* Negate -f(x) as f(-x). */
1108 if (negate_mathfn_p (builtin_mathfn_code (t))
1109 && negate_expr_p (TREE_VALUE (TREE_OPERAND (t, 1))))
1111 tree fndecl, arg, arglist;
1113 fndecl = get_callee_fndecl (t);
1114 arg = negate_expr (TREE_VALUE (TREE_OPERAND (t, 1)));
1115 arglist = build_tree_list (NULL_TREE, arg);
1116 return build_function_call_expr (fndecl, arglist);
1121 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1122 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
1124 tree op1 = TREE_OPERAND (t, 1);
1125 if (TREE_INT_CST_HIGH (op1) == 0
1126 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
1127 == TREE_INT_CST_LOW (op1))
1129 tree ntype = TYPE_UNSIGNED (type)
1130 ? lang_hooks.types.signed_type (type)
1131 : lang_hooks.types.unsigned_type (type);
1132 tree temp = fold_convert (ntype, TREE_OPERAND (t, 0));
1133 temp = fold (build2 (RSHIFT_EXPR, ntype, temp, op1));
1134 return fold_convert (type, temp);
1143 tem = fold (build1 (NEGATE_EXPR, TREE_TYPE (t), t));
1144 return fold_convert (type, tem);
1147 /* Split a tree IN into a constant, literal and variable parts that could be
1148 combined with CODE to make IN. "constant" means an expression with
1149 TREE_CONSTANT but that isn't an actual constant. CODE must be a
1150 commutative arithmetic operation. Store the constant part into *CONP,
1151 the literal in *LITP and return the variable part. If a part isn't
1152 present, set it to null. If the tree does not decompose in this way,
1153 return the entire tree as the variable part and the other parts as null.
1155 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
1156 case, we negate an operand that was subtracted. Except if it is a
1157 literal for which we use *MINUS_LITP instead.
1159 If NEGATE_P is true, we are negating all of IN, again except a literal
1160 for which we use *MINUS_LITP instead.
1162 If IN is itself a literal or constant, return it as appropriate.
1164 Note that we do not guarantee that any of the three values will be the
1165 same type as IN, but they will have the same signedness and mode. */
1168 split_tree (tree in, enum tree_code code, tree *conp, tree *litp,
1169 tree *minus_litp, int negate_p)
1177 /* Strip any conversions that don't change the machine mode or signedness. */
1178 STRIP_SIGN_NOPS (in);
1180 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST)
1182 else if (TREE_CODE (in) == code
1183 || (! FLOAT_TYPE_P (TREE_TYPE (in))
1184 /* We can associate addition and subtraction together (even
1185 though the C standard doesn't say so) for integers because
1186 the value is not affected. For reals, the value might be
1187 affected, so we can't. */
1188 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
1189 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
1191 tree op0 = TREE_OPERAND (in, 0);
1192 tree op1 = TREE_OPERAND (in, 1);
1193 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
1194 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
1196 /* First see if either of the operands is a literal, then a constant. */
1197 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
1198 *litp = op0, op0 = 0;
1199 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST)
1200 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
1202 if (op0 != 0 && TREE_CONSTANT (op0))
1203 *conp = op0, op0 = 0;
1204 else if (op1 != 0 && TREE_CONSTANT (op1))
1205 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
1207 /* If we haven't dealt with either operand, this is not a case we can
1208 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1209 if (op0 != 0 && op1 != 0)
1214 var = op1, neg_var_p = neg1_p;
1216 /* Now do any needed negations. */
1218 *minus_litp = *litp, *litp = 0;
1220 *conp = negate_expr (*conp);
1222 var = negate_expr (var);
1224 else if (TREE_CONSTANT (in))
1232 *minus_litp = *litp, *litp = 0;
1233 else if (*minus_litp)
1234 *litp = *minus_litp, *minus_litp = 0;
1235 *conp = negate_expr (*conp);
1236 var = negate_expr (var);
1242 /* Re-associate trees split by the above function. T1 and T2 are either
1243 expressions to associate or null. Return the new expression, if any. If
1244 we build an operation, do it in TYPE and with CODE. */
1247 associate_trees (tree t1, tree t2, enum tree_code code, tree type)
1254 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1255 try to fold this since we will have infinite recursion. But do
1256 deal with any NEGATE_EXPRs. */
1257 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
1258 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1260 if (code == PLUS_EXPR)
1262 if (TREE_CODE (t1) == NEGATE_EXPR)
1263 return build2 (MINUS_EXPR, type, fold_convert (type, t2),
1264 fold_convert (type, TREE_OPERAND (t1, 0)));
1265 else if (TREE_CODE (t2) == NEGATE_EXPR)
1266 return build2 (MINUS_EXPR, type, fold_convert (type, t1),
1267 fold_convert (type, TREE_OPERAND (t2, 0)));
1268 else if (integer_zerop (t2))
1269 return fold_convert (type, t1);
1271 else if (code == MINUS_EXPR)
1273 if (integer_zerop (t2))
1274 return fold_convert (type, t1);
1277 return build2 (code, type, fold_convert (type, t1),
1278 fold_convert (type, t2));
1281 return fold (build2 (code, type, fold_convert (type, t1),
1282 fold_convert (type, t2)));
1285 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1286 to produce a new constant.
1288 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1291 int_const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1293 unsigned HOST_WIDE_INT int1l, int2l;
1294 HOST_WIDE_INT int1h, int2h;
1295 unsigned HOST_WIDE_INT low;
1297 unsigned HOST_WIDE_INT garbagel;
1298 HOST_WIDE_INT garbageh;
1300 tree type = TREE_TYPE (arg1);
1301 int uns = TYPE_UNSIGNED (type);
1303 = (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type));
1305 int no_overflow = 0;
1307 int1l = TREE_INT_CST_LOW (arg1);
1308 int1h = TREE_INT_CST_HIGH (arg1);
1309 int2l = TREE_INT_CST_LOW (arg2);
1310 int2h = TREE_INT_CST_HIGH (arg2);
1315 low = int1l | int2l, hi = int1h | int2h;
1319 low = int1l ^ int2l, hi = int1h ^ int2h;
1323 low = int1l & int2l, hi = int1h & int2h;
1329 /* It's unclear from the C standard whether shifts can overflow.
1330 The following code ignores overflow; perhaps a C standard
1331 interpretation ruling is needed. */
1332 lshift_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1340 lrotate_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1345 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1349 neg_double (int2l, int2h, &low, &hi);
1350 add_double (int1l, int1h, low, hi, &low, &hi);
1351 overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
1355 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1358 case TRUNC_DIV_EXPR:
1359 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1360 case EXACT_DIV_EXPR:
1361 /* This is a shortcut for a common special case. */
1362 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1363 && ! TREE_CONSTANT_OVERFLOW (arg1)
1364 && ! TREE_CONSTANT_OVERFLOW (arg2)
1365 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1367 if (code == CEIL_DIV_EXPR)
1370 low = int1l / int2l, hi = 0;
1374 /* ... fall through ... */
1376 case ROUND_DIV_EXPR:
1377 if (int2h == 0 && int2l == 1)
1379 low = int1l, hi = int1h;
1382 if (int1l == int2l && int1h == int2h
1383 && ! (int1l == 0 && int1h == 0))
1388 overflow = div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
1389 &low, &hi, &garbagel, &garbageh);
1392 case TRUNC_MOD_EXPR:
1393 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1394 /* This is a shortcut for a common special case. */
1395 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1396 && ! TREE_CONSTANT_OVERFLOW (arg1)
1397 && ! TREE_CONSTANT_OVERFLOW (arg2)
1398 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1400 if (code == CEIL_MOD_EXPR)
1402 low = int1l % int2l, hi = 0;
1406 /* ... fall through ... */
1408 case ROUND_MOD_EXPR:
1409 overflow = div_and_round_double (code, uns,
1410 int1l, int1h, int2l, int2h,
1411 &garbagel, &garbageh, &low, &hi);
1417 low = (((unsigned HOST_WIDE_INT) int1h
1418 < (unsigned HOST_WIDE_INT) int2h)
1419 || (((unsigned HOST_WIDE_INT) int1h
1420 == (unsigned HOST_WIDE_INT) int2h)
1423 low = (int1h < int2h
1424 || (int1h == int2h && int1l < int2l));
1426 if (low == (code == MIN_EXPR))
1427 low = int1l, hi = int1h;
1429 low = int2l, hi = int2h;
1436 t = build_int_cst_wide (TREE_TYPE (arg1), low, hi);
1440 /* Propagate overflow flags ourselves. */
1441 if (((!uns || is_sizetype) && overflow)
1442 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2))
1445 TREE_OVERFLOW (t) = 1;
1446 TREE_CONSTANT_OVERFLOW (t) = 1;
1448 else if (TREE_CONSTANT_OVERFLOW (arg1) | TREE_CONSTANT_OVERFLOW (arg2))
1451 TREE_CONSTANT_OVERFLOW (t) = 1;
1455 t = force_fit_type (t, 1,
1456 ((!uns || is_sizetype) && overflow)
1457 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2),
1458 TREE_CONSTANT_OVERFLOW (arg1)
1459 | TREE_CONSTANT_OVERFLOW (arg2));
1464 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1465 constant. We assume ARG1 and ARG2 have the same data type, or at least
1466 are the same kind of constant and the same machine mode.
1468 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1471 const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1476 if (TREE_CODE (arg1) == INTEGER_CST)
1477 return int_const_binop (code, arg1, arg2, notrunc);
1479 if (TREE_CODE (arg1) == REAL_CST)
1481 enum machine_mode mode;
1484 REAL_VALUE_TYPE value;
1485 REAL_VALUE_TYPE result;
1489 d1 = TREE_REAL_CST (arg1);
1490 d2 = TREE_REAL_CST (arg2);
1492 type = TREE_TYPE (arg1);
1493 mode = TYPE_MODE (type);
1495 /* Don't perform operation if we honor signaling NaNs and
1496 either operand is a NaN. */
1497 if (HONOR_SNANS (mode)
1498 && (REAL_VALUE_ISNAN (d1) || REAL_VALUE_ISNAN (d2)))
1501 /* Don't perform operation if it would raise a division
1502 by zero exception. */
1503 if (code == RDIV_EXPR
1504 && REAL_VALUES_EQUAL (d2, dconst0)
1505 && (flag_trapping_math || ! MODE_HAS_INFINITIES (mode)))
1508 /* If either operand is a NaN, just return it. Otherwise, set up
1509 for floating-point trap; we return an overflow. */
1510 if (REAL_VALUE_ISNAN (d1))
1512 else if (REAL_VALUE_ISNAN (d2))
1515 inexact = real_arithmetic (&value, code, &d1, &d2);
1516 real_convert (&result, mode, &value);
1518 /* Don't constant fold this floating point operation if the
1519 result may dependent upon the run-time rounding mode and
1520 flag_rounding_math is set, or if GCC's software emulation
1521 is unable to accurately represent the result. */
1523 if ((flag_rounding_math
1524 || (REAL_MODE_FORMAT_COMPOSITE_P (mode)
1525 && !flag_unsafe_math_optimizations))
1526 && (inexact || !real_identical (&result, &value)))
1529 t = build_real (type, result);
1531 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2);
1532 TREE_CONSTANT_OVERFLOW (t)
1534 | TREE_CONSTANT_OVERFLOW (arg1)
1535 | TREE_CONSTANT_OVERFLOW (arg2);
1538 if (TREE_CODE (arg1) == COMPLEX_CST)
1540 tree type = TREE_TYPE (arg1);
1541 tree r1 = TREE_REALPART (arg1);
1542 tree i1 = TREE_IMAGPART (arg1);
1543 tree r2 = TREE_REALPART (arg2);
1544 tree i2 = TREE_IMAGPART (arg2);
1550 t = build_complex (type,
1551 const_binop (PLUS_EXPR, r1, r2, notrunc),
1552 const_binop (PLUS_EXPR, i1, i2, notrunc));
1556 t = build_complex (type,
1557 const_binop (MINUS_EXPR, r1, r2, notrunc),
1558 const_binop (MINUS_EXPR, i1, i2, notrunc));
1562 t = build_complex (type,
1563 const_binop (MINUS_EXPR,
1564 const_binop (MULT_EXPR,
1566 const_binop (MULT_EXPR,
1569 const_binop (PLUS_EXPR,
1570 const_binop (MULT_EXPR,
1572 const_binop (MULT_EXPR,
1580 = const_binop (PLUS_EXPR,
1581 const_binop (MULT_EXPR, r2, r2, notrunc),
1582 const_binop (MULT_EXPR, i2, i2, notrunc),
1585 t = build_complex (type,
1587 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1588 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1589 const_binop (PLUS_EXPR,
1590 const_binop (MULT_EXPR, r1, r2,
1592 const_binop (MULT_EXPR, i1, i2,
1595 magsquared, notrunc),
1597 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1598 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1599 const_binop (MINUS_EXPR,
1600 const_binop (MULT_EXPR, i1, r2,
1602 const_binop (MULT_EXPR, r1, i2,
1605 magsquared, notrunc));
1617 /* Create a size type INT_CST node with NUMBER sign extended. KIND
1618 indicates which particular sizetype to create. */
1621 size_int_kind (HOST_WIDE_INT number, enum size_type_kind kind)
1623 return build_int_cst (sizetype_tab[(int) kind], number);
1626 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1627 is a tree code. The type of the result is taken from the operands.
1628 Both must be the same type integer type and it must be a size type.
1629 If the operands are constant, so is the result. */
1632 size_binop (enum tree_code code, tree arg0, tree arg1)
1634 tree type = TREE_TYPE (arg0);
1636 gcc_assert (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type)
1637 && type == TREE_TYPE (arg1));
1639 /* Handle the special case of two integer constants faster. */
1640 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1642 /* And some specific cases even faster than that. */
1643 if (code == PLUS_EXPR && integer_zerop (arg0))
1645 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1646 && integer_zerop (arg1))
1648 else if (code == MULT_EXPR && integer_onep (arg0))
1651 /* Handle general case of two integer constants. */
1652 return int_const_binop (code, arg0, arg1, 0);
1655 if (arg0 == error_mark_node || arg1 == error_mark_node)
1656 return error_mark_node;
1658 return fold (build2 (code, type, arg0, arg1));
1661 /* Given two values, either both of sizetype or both of bitsizetype,
1662 compute the difference between the two values. Return the value
1663 in signed type corresponding to the type of the operands. */
1666 size_diffop (tree arg0, tree arg1)
1668 tree type = TREE_TYPE (arg0);
1671 gcc_assert (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type)
1672 && type == TREE_TYPE (arg1));
1674 /* If the type is already signed, just do the simple thing. */
1675 if (!TYPE_UNSIGNED (type))
1676 return size_binop (MINUS_EXPR, arg0, arg1);
1678 ctype = type == bitsizetype ? sbitsizetype : ssizetype;
1680 /* If either operand is not a constant, do the conversions to the signed
1681 type and subtract. The hardware will do the right thing with any
1682 overflow in the subtraction. */
1683 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
1684 return size_binop (MINUS_EXPR, fold_convert (ctype, arg0),
1685 fold_convert (ctype, arg1));
1687 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
1688 Otherwise, subtract the other way, convert to CTYPE (we know that can't
1689 overflow) and negate (which can't either). Special-case a result
1690 of zero while we're here. */
1691 if (tree_int_cst_equal (arg0, arg1))
1692 return fold_convert (ctype, integer_zero_node);
1693 else if (tree_int_cst_lt (arg1, arg0))
1694 return fold_convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
1696 return size_binop (MINUS_EXPR, fold_convert (ctype, integer_zero_node),
1697 fold_convert (ctype, size_binop (MINUS_EXPR,
1701 /* A subroutine of fold_convert_const handling conversions of an
1702 INTEGER_CST to another integer type. */
1705 fold_convert_const_int_from_int (tree type, tree arg1)
1709 /* Given an integer constant, make new constant with new type,
1710 appropriately sign-extended or truncated. */
1711 t = build_int_cst_wide (type, TREE_INT_CST_LOW (arg1),
1712 TREE_INT_CST_HIGH (arg1));
1714 t = force_fit_type (t,
1715 /* Don't set the overflow when
1716 converting a pointer */
1717 !POINTER_TYPE_P (TREE_TYPE (arg1)),
1718 (TREE_INT_CST_HIGH (arg1) < 0
1719 && (TYPE_UNSIGNED (type)
1720 < TYPE_UNSIGNED (TREE_TYPE (arg1))))
1721 | TREE_OVERFLOW (arg1),
1722 TREE_CONSTANT_OVERFLOW (arg1));
1727 /* A subroutine of fold_convert_const handling conversions a REAL_CST
1728 to an integer type. */
1731 fold_convert_const_int_from_real (enum tree_code code, tree type, tree arg1)
1736 /* The following code implements the floating point to integer
1737 conversion rules required by the Java Language Specification,
1738 that IEEE NaNs are mapped to zero and values that overflow
1739 the target precision saturate, i.e. values greater than
1740 INT_MAX are mapped to INT_MAX, and values less than INT_MIN
1741 are mapped to INT_MIN. These semantics are allowed by the
1742 C and C++ standards that simply state that the behavior of
1743 FP-to-integer conversion is unspecified upon overflow. */
1745 HOST_WIDE_INT high, low;
1747 REAL_VALUE_TYPE x = TREE_REAL_CST (arg1);
1751 case FIX_TRUNC_EXPR:
1752 real_trunc (&r, VOIDmode, &x);
1756 real_ceil (&r, VOIDmode, &x);
1759 case FIX_FLOOR_EXPR:
1760 real_floor (&r, VOIDmode, &x);
1763 case FIX_ROUND_EXPR:
1764 real_round (&r, VOIDmode, &x);
1771 /* If R is NaN, return zero and show we have an overflow. */
1772 if (REAL_VALUE_ISNAN (r))
1779 /* See if R is less than the lower bound or greater than the
1784 tree lt = TYPE_MIN_VALUE (type);
1785 REAL_VALUE_TYPE l = real_value_from_int_cst (NULL_TREE, lt);
1786 if (REAL_VALUES_LESS (r, l))
1789 high = TREE_INT_CST_HIGH (lt);
1790 low = TREE_INT_CST_LOW (lt);
1796 tree ut = TYPE_MAX_VALUE (type);
1799 REAL_VALUE_TYPE u = real_value_from_int_cst (NULL_TREE, ut);
1800 if (REAL_VALUES_LESS (u, r))
1803 high = TREE_INT_CST_HIGH (ut);
1804 low = TREE_INT_CST_LOW (ut);
1810 REAL_VALUE_TO_INT (&low, &high, r);
1812 t = build_int_cst_wide (type, low, high);
1814 t = force_fit_type (t, -1, overflow | TREE_OVERFLOW (arg1),
1815 TREE_CONSTANT_OVERFLOW (arg1));
1819 /* A subroutine of fold_convert_const handling conversions a REAL_CST
1820 to another floating point type. */
1823 fold_convert_const_real_from_real (tree type, tree arg1)
1825 REAL_VALUE_TYPE value;
1828 real_convert (&value, TYPE_MODE (type), &TREE_REAL_CST (arg1));
1829 t = build_real (type, value);
1831 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1);
1832 TREE_CONSTANT_OVERFLOW (t)
1833 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1837 /* Attempt to fold type conversion operation CODE of expression ARG1 to
1838 type TYPE. If no simplification can be done return NULL_TREE. */
1841 fold_convert_const (enum tree_code code, tree type, tree arg1)
1843 if (TREE_TYPE (arg1) == type)
1846 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
1848 if (TREE_CODE (arg1) == INTEGER_CST)
1849 return fold_convert_const_int_from_int (type, arg1);
1850 else if (TREE_CODE (arg1) == REAL_CST)
1851 return fold_convert_const_int_from_real (code, type, arg1);
1853 else if (TREE_CODE (type) == REAL_TYPE)
1855 if (TREE_CODE (arg1) == INTEGER_CST)
1856 return build_real_from_int_cst (type, arg1);
1857 if (TREE_CODE (arg1) == REAL_CST)
1858 return fold_convert_const_real_from_real (type, arg1);
1863 /* Construct a vector of zero elements of vector type TYPE. */
1866 build_zero_vector (tree type)
1871 elem = fold_convert_const (NOP_EXPR, TREE_TYPE (type), integer_zero_node);
1872 units = TYPE_VECTOR_SUBPARTS (type);
1875 for (i = 0; i < units; i++)
1876 list = tree_cons (NULL_TREE, elem, list);
1877 return build_vector (type, list);
1880 /* Convert expression ARG to type TYPE. Used by the middle-end for
1881 simple conversions in preference to calling the front-end's convert. */
1884 fold_convert (tree type, tree arg)
1886 tree orig = TREE_TYPE (arg);
1892 if (TREE_CODE (arg) == ERROR_MARK
1893 || TREE_CODE (type) == ERROR_MARK
1894 || TREE_CODE (orig) == ERROR_MARK)
1895 return error_mark_node;
1897 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig)
1898 || lang_hooks.types_compatible_p (TYPE_MAIN_VARIANT (type),
1899 TYPE_MAIN_VARIANT (orig)))
1900 return fold (build1 (NOP_EXPR, type, arg));
1902 switch (TREE_CODE (type))
1904 case INTEGER_TYPE: case CHAR_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
1905 case POINTER_TYPE: case REFERENCE_TYPE:
1907 if (TREE_CODE (arg) == INTEGER_CST)
1909 tem = fold_convert_const (NOP_EXPR, type, arg);
1910 if (tem != NULL_TREE)
1913 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
1914 || TREE_CODE (orig) == OFFSET_TYPE)
1915 return fold (build1 (NOP_EXPR, type, arg));
1916 if (TREE_CODE (orig) == COMPLEX_TYPE)
1918 tem = fold (build1 (REALPART_EXPR, TREE_TYPE (orig), arg));
1919 return fold_convert (type, tem);
1921 gcc_assert (TREE_CODE (orig) == VECTOR_TYPE
1922 && tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
1923 return fold (build1 (NOP_EXPR, type, arg));
1926 if (TREE_CODE (arg) == INTEGER_CST)
1928 tem = fold_convert_const (FLOAT_EXPR, type, arg);
1929 if (tem != NULL_TREE)
1932 else if (TREE_CODE (arg) == REAL_CST)
1934 tem = fold_convert_const (NOP_EXPR, type, arg);
1935 if (tem != NULL_TREE)
1939 switch (TREE_CODE (orig))
1941 case INTEGER_TYPE: case CHAR_TYPE:
1942 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
1943 case POINTER_TYPE: case REFERENCE_TYPE:
1944 return fold (build1 (FLOAT_EXPR, type, arg));
1947 return fold (build1 (flag_float_store ? CONVERT_EXPR : NOP_EXPR,
1951 tem = fold (build1 (REALPART_EXPR, TREE_TYPE (orig), arg));
1952 return fold_convert (type, tem);
1959 switch (TREE_CODE (orig))
1961 case INTEGER_TYPE: case CHAR_TYPE:
1962 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
1963 case POINTER_TYPE: case REFERENCE_TYPE:
1965 return build2 (COMPLEX_EXPR, type,
1966 fold_convert (TREE_TYPE (type), arg),
1967 fold_convert (TREE_TYPE (type), integer_zero_node));
1972 if (TREE_CODE (arg) == COMPLEX_EXPR)
1974 rpart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 0));
1975 ipart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 1));
1976 return fold (build2 (COMPLEX_EXPR, type, rpart, ipart));
1979 arg = save_expr (arg);
1980 rpart = fold (build1 (REALPART_EXPR, TREE_TYPE (orig), arg));
1981 ipart = fold (build1 (IMAGPART_EXPR, TREE_TYPE (orig), arg));
1982 rpart = fold_convert (TREE_TYPE (type), rpart);
1983 ipart = fold_convert (TREE_TYPE (type), ipart);
1984 return fold (build2 (COMPLEX_EXPR, type, rpart, ipart));
1992 if (integer_zerop (arg))
1993 return build_zero_vector (type);
1994 gcc_assert (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
1995 gcc_assert (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
1996 || TREE_CODE (orig) == VECTOR_TYPE);
1997 return fold (build1 (NOP_EXPR, type, arg));
2000 return fold (build1 (CONVERT_EXPR, type, fold_ignored_result (arg)));
2007 /* Return an expr equal to X but certainly not valid as an lvalue. */
2012 /* While we are in GIMPLE, NON_LVALUE_EXPR doesn't mean anything to
2017 /* We only need to wrap lvalue tree codes. */
2018 switch (TREE_CODE (x))
2029 case ALIGN_INDIRECT_REF:
2030 case MISALIGNED_INDIRECT_REF:
2032 case ARRAY_RANGE_REF:
2038 case PREINCREMENT_EXPR:
2039 case PREDECREMENT_EXPR:
2041 case TRY_CATCH_EXPR:
2042 case WITH_CLEANUP_EXPR:
2053 /* Assume the worst for front-end tree codes. */
2054 if ((int)TREE_CODE (x) >= NUM_TREE_CODES)
2058 return build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
2061 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
2062 Zero means allow extended lvalues. */
2064 int pedantic_lvalues;
2066 /* When pedantic, return an expr equal to X but certainly not valid as a
2067 pedantic lvalue. Otherwise, return X. */
2070 pedantic_non_lvalue (tree x)
2072 if (pedantic_lvalues)
2073 return non_lvalue (x);
2078 /* Given a tree comparison code, return the code that is the logical inverse
2079 of the given code. It is not safe to do this for floating-point
2080 comparisons, except for NE_EXPR and EQ_EXPR, so we receive a machine mode
2081 as well: if reversing the comparison is unsafe, return ERROR_MARK. */
2083 static enum tree_code
2084 invert_tree_comparison (enum tree_code code, bool honor_nans)
2086 if (honor_nans && flag_trapping_math)
2096 return honor_nans ? UNLE_EXPR : LE_EXPR;
2098 return honor_nans ? UNLT_EXPR : LT_EXPR;
2100 return honor_nans ? UNGE_EXPR : GE_EXPR;
2102 return honor_nans ? UNGT_EXPR : GT_EXPR;
2116 return UNORDERED_EXPR;
2117 case UNORDERED_EXPR:
2118 return ORDERED_EXPR;
2124 /* Similar, but return the comparison that results if the operands are
2125 swapped. This is safe for floating-point. */
2128 swap_tree_comparison (enum tree_code code)
2149 /* Convert a comparison tree code from an enum tree_code representation
2150 into a compcode bit-based encoding. This function is the inverse of
2151 compcode_to_comparison. */
2153 static enum comparison_code
2154 comparison_to_compcode (enum tree_code code)
2171 return COMPCODE_ORD;
2172 case UNORDERED_EXPR:
2173 return COMPCODE_UNORD;
2175 return COMPCODE_UNLT;
2177 return COMPCODE_UNEQ;
2179 return COMPCODE_UNLE;
2181 return COMPCODE_UNGT;
2183 return COMPCODE_LTGT;
2185 return COMPCODE_UNGE;
2191 /* Convert a compcode bit-based encoding of a comparison operator back
2192 to GCC's enum tree_code representation. This function is the
2193 inverse of comparison_to_compcode. */
2195 static enum tree_code
2196 compcode_to_comparison (enum comparison_code code)
2213 return ORDERED_EXPR;
2214 case COMPCODE_UNORD:
2215 return UNORDERED_EXPR;
2233 /* Return a tree for the comparison which is the combination of
2234 doing the AND or OR (depending on CODE) of the two operations LCODE
2235 and RCODE on the identical operands LL_ARG and LR_ARG. Take into account
2236 the possibility of trapping if the mode has NaNs, and return NULL_TREE
2237 if this makes the transformation invalid. */
2240 combine_comparisons (enum tree_code code, enum tree_code lcode,
2241 enum tree_code rcode, tree truth_type,
2242 tree ll_arg, tree lr_arg)
2244 bool honor_nans = HONOR_NANS (TYPE_MODE (TREE_TYPE (ll_arg)));
2245 enum comparison_code lcompcode = comparison_to_compcode (lcode);
2246 enum comparison_code rcompcode = comparison_to_compcode (rcode);
2247 enum comparison_code compcode;
2251 case TRUTH_AND_EXPR: case TRUTH_ANDIF_EXPR:
2252 compcode = lcompcode & rcompcode;
2255 case TRUTH_OR_EXPR: case TRUTH_ORIF_EXPR:
2256 compcode = lcompcode | rcompcode;
2265 /* Eliminate unordered comparisons, as well as LTGT and ORD
2266 which are not used unless the mode has NaNs. */
2267 compcode &= ~COMPCODE_UNORD;
2268 if (compcode == COMPCODE_LTGT)
2269 compcode = COMPCODE_NE;
2270 else if (compcode == COMPCODE_ORD)
2271 compcode = COMPCODE_TRUE;
2273 else if (flag_trapping_math)
2275 /* Check that the original operation and the optimized ones will trap
2276 under the same condition. */
2277 bool ltrap = (lcompcode & COMPCODE_UNORD) == 0
2278 && (lcompcode != COMPCODE_EQ)
2279 && (lcompcode != COMPCODE_ORD);
2280 bool rtrap = (rcompcode & COMPCODE_UNORD) == 0
2281 && (rcompcode != COMPCODE_EQ)
2282 && (rcompcode != COMPCODE_ORD);
2283 bool trap = (compcode & COMPCODE_UNORD) == 0
2284 && (compcode != COMPCODE_EQ)
2285 && (compcode != COMPCODE_ORD);
2287 /* In a short-circuited boolean expression the LHS might be
2288 such that the RHS, if evaluated, will never trap. For
2289 example, in ORD (x, y) && (x < y), we evaluate the RHS only
2290 if neither x nor y is NaN. (This is a mixed blessing: for
2291 example, the expression above will never trap, hence
2292 optimizing it to x < y would be invalid). */
2293 if ((code == TRUTH_ORIF_EXPR && (lcompcode & COMPCODE_UNORD))
2294 || (code == TRUTH_ANDIF_EXPR && !(lcompcode & COMPCODE_UNORD)))
2297 /* If the comparison was short-circuited, and only the RHS
2298 trapped, we may now generate a spurious trap. */
2300 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2303 /* If we changed the conditions that cause a trap, we lose. */
2304 if ((ltrap || rtrap) != trap)
2308 if (compcode == COMPCODE_TRUE)
2309 return constant_boolean_node (true, truth_type);
2310 else if (compcode == COMPCODE_FALSE)
2311 return constant_boolean_node (false, truth_type);
2313 return fold (build2 (compcode_to_comparison (compcode),
2314 truth_type, ll_arg, lr_arg));
2317 /* Return nonzero if CODE is a tree code that represents a truth value. */
2320 truth_value_p (enum tree_code code)
2322 return (TREE_CODE_CLASS (code) == tcc_comparison
2323 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2324 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2325 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
2328 /* Return nonzero if two operands (typically of the same tree node)
2329 are necessarily equal. If either argument has side-effects this
2330 function returns zero. FLAGS modifies behavior as follows:
2332 If OEP_ONLY_CONST is set, only return nonzero for constants.
2333 This function tests whether the operands are indistinguishable;
2334 it does not test whether they are equal using C's == operation.
2335 The distinction is important for IEEE floating point, because
2336 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2337 (2) two NaNs may be indistinguishable, but NaN!=NaN.
2339 If OEP_ONLY_CONST is unset, a VAR_DECL is considered equal to itself
2340 even though it may hold multiple values during a function.
2341 This is because a GCC tree node guarantees that nothing else is
2342 executed between the evaluation of its "operands" (which may often
2343 be evaluated in arbitrary order). Hence if the operands themselves
2344 don't side-effect, the VAR_DECLs, PARM_DECLs etc... must hold the
2345 same value in each operand/subexpression. Hence leaving OEP_ONLY_CONST
2346 unset means assuming isochronic (or instantaneous) tree equivalence.
2347 Unless comparing arbitrary expression trees, such as from different
2348 statements, this flag can usually be left unset.
2350 If OEP_PURE_SAME is set, then pure functions with identical arguments
2351 are considered the same. It is used when the caller has other ways
2352 to ensure that global memory is unchanged in between. */
2355 operand_equal_p (tree arg0, tree arg1, unsigned int flags)
2357 /* If either is ERROR_MARK, they aren't equal. */
2358 if (TREE_CODE (arg0) == ERROR_MARK || TREE_CODE (arg1) == ERROR_MARK)
2361 /* If both types don't have the same signedness, then we can't consider
2362 them equal. We must check this before the STRIP_NOPS calls
2363 because they may change the signedness of the arguments. */
2364 if (TYPE_UNSIGNED (TREE_TYPE (arg0)) != TYPE_UNSIGNED (TREE_TYPE (arg1)))
2370 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2371 /* This is needed for conversions and for COMPONENT_REF.
2372 Might as well play it safe and always test this. */
2373 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
2374 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
2375 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
2378 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
2379 We don't care about side effects in that case because the SAVE_EXPR
2380 takes care of that for us. In all other cases, two expressions are
2381 equal if they have no side effects. If we have two identical
2382 expressions with side effects that should be treated the same due
2383 to the only side effects being identical SAVE_EXPR's, that will
2384 be detected in the recursive calls below. */
2385 if (arg0 == arg1 && ! (flags & OEP_ONLY_CONST)
2386 && (TREE_CODE (arg0) == SAVE_EXPR
2387 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
2390 /* Next handle constant cases, those for which we can return 1 even
2391 if ONLY_CONST is set. */
2392 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
2393 switch (TREE_CODE (arg0))
2396 return (! TREE_CONSTANT_OVERFLOW (arg0)
2397 && ! TREE_CONSTANT_OVERFLOW (arg1)
2398 && tree_int_cst_equal (arg0, arg1));
2401 return (! TREE_CONSTANT_OVERFLOW (arg0)
2402 && ! TREE_CONSTANT_OVERFLOW (arg1)
2403 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
2404 TREE_REAL_CST (arg1)));
2410 if (TREE_CONSTANT_OVERFLOW (arg0)
2411 || TREE_CONSTANT_OVERFLOW (arg1))
2414 v1 = TREE_VECTOR_CST_ELTS (arg0);
2415 v2 = TREE_VECTOR_CST_ELTS (arg1);
2418 if (!operand_equal_p (TREE_VALUE (v1), TREE_VALUE (v2),
2421 v1 = TREE_CHAIN (v1);
2422 v2 = TREE_CHAIN (v2);
2429 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
2431 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
2435 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
2436 && ! memcmp (TREE_STRING_POINTER (arg0),
2437 TREE_STRING_POINTER (arg1),
2438 TREE_STRING_LENGTH (arg0)));
2441 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
2447 if (flags & OEP_ONLY_CONST)
2450 /* Define macros to test an operand from arg0 and arg1 for equality and a
2451 variant that allows null and views null as being different from any
2452 non-null value. In the latter case, if either is null, the both
2453 must be; otherwise, do the normal comparison. */
2454 #define OP_SAME(N) operand_equal_p (TREE_OPERAND (arg0, N), \
2455 TREE_OPERAND (arg1, N), flags)
2457 #define OP_SAME_WITH_NULL(N) \
2458 ((!TREE_OPERAND (arg0, N) || !TREE_OPERAND (arg1, N)) \
2459 ? TREE_OPERAND (arg0, N) == TREE_OPERAND (arg1, N) : OP_SAME (N))
2461 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
2464 /* Two conversions are equal only if signedness and modes match. */
2465 switch (TREE_CODE (arg0))
2470 case FIX_TRUNC_EXPR:
2471 case FIX_FLOOR_EXPR:
2472 case FIX_ROUND_EXPR:
2473 if (TYPE_UNSIGNED (TREE_TYPE (arg0))
2474 != TYPE_UNSIGNED (TREE_TYPE (arg1)))
2484 case tcc_comparison:
2486 if (OP_SAME (0) && OP_SAME (1))
2489 /* For commutative ops, allow the other order. */
2490 return (commutative_tree_code (TREE_CODE (arg0))
2491 && operand_equal_p (TREE_OPERAND (arg0, 0),
2492 TREE_OPERAND (arg1, 1), flags)
2493 && operand_equal_p (TREE_OPERAND (arg0, 1),
2494 TREE_OPERAND (arg1, 0), flags));
2497 /* If either of the pointer (or reference) expressions we are
2498 dereferencing contain a side effect, these cannot be equal. */
2499 if (TREE_SIDE_EFFECTS (arg0)
2500 || TREE_SIDE_EFFECTS (arg1))
2503 switch (TREE_CODE (arg0))
2506 case ALIGN_INDIRECT_REF:
2507 case MISALIGNED_INDIRECT_REF:
2513 case ARRAY_RANGE_REF:
2514 /* Operands 2 and 3 may be null. */
2517 && OP_SAME_WITH_NULL (2)
2518 && OP_SAME_WITH_NULL (3));
2521 /* Handle operand 2 the same as for ARRAY_REF. */
2522 return OP_SAME (0) && OP_SAME (1) && OP_SAME_WITH_NULL (2);
2525 return OP_SAME (0) && OP_SAME (1) && OP_SAME (2);
2531 case tcc_expression:
2532 switch (TREE_CODE (arg0))
2535 case TRUTH_NOT_EXPR:
2538 case TRUTH_ANDIF_EXPR:
2539 case TRUTH_ORIF_EXPR:
2540 return OP_SAME (0) && OP_SAME (1);
2542 case TRUTH_AND_EXPR:
2544 case TRUTH_XOR_EXPR:
2545 if (OP_SAME (0) && OP_SAME (1))
2548 /* Otherwise take into account this is a commutative operation. */
2549 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2550 TREE_OPERAND (arg1, 1), flags)
2551 && operand_equal_p (TREE_OPERAND (arg0, 1),
2552 TREE_OPERAND (arg1, 0), flags));
2555 /* If the CALL_EXPRs call different functions, then they
2556 clearly can not be equal. */
2561 unsigned int cef = call_expr_flags (arg0);
2562 if (flags & OEP_PURE_SAME)
2563 cef &= ECF_CONST | ECF_PURE;
2570 /* Now see if all the arguments are the same. operand_equal_p
2571 does not handle TREE_LIST, so we walk the operands here
2572 feeding them to operand_equal_p. */
2573 arg0 = TREE_OPERAND (arg0, 1);
2574 arg1 = TREE_OPERAND (arg1, 1);
2575 while (arg0 && arg1)
2577 if (! operand_equal_p (TREE_VALUE (arg0), TREE_VALUE (arg1),
2581 arg0 = TREE_CHAIN (arg0);
2582 arg1 = TREE_CHAIN (arg1);
2585 /* If we get here and both argument lists are exhausted
2586 then the CALL_EXPRs are equal. */
2587 return ! (arg0 || arg1);
2593 case tcc_declaration:
2594 /* Consider __builtin_sqrt equal to sqrt. */
2595 return (TREE_CODE (arg0) == FUNCTION_DECL
2596 && DECL_BUILT_IN (arg0) && DECL_BUILT_IN (arg1)
2597 && DECL_BUILT_IN_CLASS (arg0) == DECL_BUILT_IN_CLASS (arg1)
2598 && DECL_FUNCTION_CODE (arg0) == DECL_FUNCTION_CODE (arg1));
2605 #undef OP_SAME_WITH_NULL
2608 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2609 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2611 When in doubt, return 0. */
2614 operand_equal_for_comparison_p (tree arg0, tree arg1, tree other)
2616 int unsignedp1, unsignedpo;
2617 tree primarg0, primarg1, primother;
2618 unsigned int correct_width;
2620 if (operand_equal_p (arg0, arg1, 0))
2623 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
2624 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
2627 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2628 and see if the inner values are the same. This removes any
2629 signedness comparison, which doesn't matter here. */
2630 primarg0 = arg0, primarg1 = arg1;
2631 STRIP_NOPS (primarg0);
2632 STRIP_NOPS (primarg1);
2633 if (operand_equal_p (primarg0, primarg1, 0))
2636 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2637 actual comparison operand, ARG0.
2639 First throw away any conversions to wider types
2640 already present in the operands. */
2642 primarg1 = get_narrower (arg1, &unsignedp1);
2643 primother = get_narrower (other, &unsignedpo);
2645 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
2646 if (unsignedp1 == unsignedpo
2647 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
2648 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
2650 tree type = TREE_TYPE (arg0);
2652 /* Make sure shorter operand is extended the right way
2653 to match the longer operand. */
2654 primarg1 = fold_convert (lang_hooks.types.signed_or_unsigned_type
2655 (unsignedp1, TREE_TYPE (primarg1)), primarg1);
2657 if (operand_equal_p (arg0, fold_convert (type, primarg1), 0))
2664 /* See if ARG is an expression that is either a comparison or is performing
2665 arithmetic on comparisons. The comparisons must only be comparing
2666 two different values, which will be stored in *CVAL1 and *CVAL2; if
2667 they are nonzero it means that some operands have already been found.
2668 No variables may be used anywhere else in the expression except in the
2669 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2670 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2672 If this is true, return 1. Otherwise, return zero. */
2675 twoval_comparison_p (tree arg, tree *cval1, tree *cval2, int *save_p)
2677 enum tree_code code = TREE_CODE (arg);
2678 enum tree_code_class class = TREE_CODE_CLASS (code);
2680 /* We can handle some of the tcc_expression cases here. */
2681 if (class == tcc_expression && code == TRUTH_NOT_EXPR)
2683 else if (class == tcc_expression
2684 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
2685 || code == COMPOUND_EXPR))
2688 else if (class == tcc_expression && code == SAVE_EXPR
2689 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
2691 /* If we've already found a CVAL1 or CVAL2, this expression is
2692 two complex to handle. */
2693 if (*cval1 || *cval2)
2703 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
2706 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
2707 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2708 cval1, cval2, save_p));
2713 case tcc_expression:
2714 if (code == COND_EXPR)
2715 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
2716 cval1, cval2, save_p)
2717 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2718 cval1, cval2, save_p)
2719 && twoval_comparison_p (TREE_OPERAND (arg, 2),
2720 cval1, cval2, save_p));
2723 case tcc_comparison:
2724 /* First see if we can handle the first operand, then the second. For
2725 the second operand, we know *CVAL1 can't be zero. It must be that
2726 one side of the comparison is each of the values; test for the
2727 case where this isn't true by failing if the two operands
2730 if (operand_equal_p (TREE_OPERAND (arg, 0),
2731 TREE_OPERAND (arg, 1), 0))
2735 *cval1 = TREE_OPERAND (arg, 0);
2736 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
2738 else if (*cval2 == 0)
2739 *cval2 = TREE_OPERAND (arg, 0);
2740 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
2745 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
2747 else if (*cval2 == 0)
2748 *cval2 = TREE_OPERAND (arg, 1);
2749 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
2761 /* ARG is a tree that is known to contain just arithmetic operations and
2762 comparisons. Evaluate the operations in the tree substituting NEW0 for
2763 any occurrence of OLD0 as an operand of a comparison and likewise for
2767 eval_subst (tree arg, tree old0, tree new0, tree old1, tree new1)
2769 tree type = TREE_TYPE (arg);
2770 enum tree_code code = TREE_CODE (arg);
2771 enum tree_code_class class = TREE_CODE_CLASS (code);
2773 /* We can handle some of the tcc_expression cases here. */
2774 if (class == tcc_expression && code == TRUTH_NOT_EXPR)
2776 else if (class == tcc_expression
2777 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2783 return fold (build1 (code, type,
2784 eval_subst (TREE_OPERAND (arg, 0),
2785 old0, new0, old1, new1)));
2788 return fold (build2 (code, type,
2789 eval_subst (TREE_OPERAND (arg, 0),
2790 old0, new0, old1, new1),
2791 eval_subst (TREE_OPERAND (arg, 1),
2792 old0, new0, old1, new1)));
2794 case tcc_expression:
2798 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
2801 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
2804 return fold (build3 (code, type,
2805 eval_subst (TREE_OPERAND (arg, 0),
2806 old0, new0, old1, new1),
2807 eval_subst (TREE_OPERAND (arg, 1),
2808 old0, new0, old1, new1),
2809 eval_subst (TREE_OPERAND (arg, 2),
2810 old0, new0, old1, new1)));
2814 /* Fall through - ??? */
2816 case tcc_comparison:
2818 tree arg0 = TREE_OPERAND (arg, 0);
2819 tree arg1 = TREE_OPERAND (arg, 1);
2821 /* We need to check both for exact equality and tree equality. The
2822 former will be true if the operand has a side-effect. In that
2823 case, we know the operand occurred exactly once. */
2825 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
2827 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
2830 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
2832 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
2835 return fold (build2 (code, type, arg0, arg1));
2843 /* Return a tree for the case when the result of an expression is RESULT
2844 converted to TYPE and OMITTED was previously an operand of the expression
2845 but is now not needed (e.g., we folded OMITTED * 0).
2847 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2848 the conversion of RESULT to TYPE. */
2851 omit_one_operand (tree type, tree result, tree omitted)
2853 tree t = fold_convert (type, result);
2855 if (TREE_SIDE_EFFECTS (omitted))
2856 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
2858 return non_lvalue (t);
2861 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2864 pedantic_omit_one_operand (tree type, tree result, tree omitted)
2866 tree t = fold_convert (type, result);
2868 if (TREE_SIDE_EFFECTS (omitted))
2869 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
2871 return pedantic_non_lvalue (t);
2874 /* Return a tree for the case when the result of an expression is RESULT
2875 converted to TYPE and OMITTED1 and OMITTED2 were previously operands
2876 of the expression but are now not needed.
2878 If OMITTED1 or OMITTED2 has side effects, they must be evaluated.
2879 If both OMITTED1 and OMITTED2 have side effects, OMITTED1 is
2880 evaluated before OMITTED2. Otherwise, if neither has side effects,
2881 just do the conversion of RESULT to TYPE. */
2884 omit_two_operands (tree type, tree result, tree omitted1, tree omitted2)
2886 tree t = fold_convert (type, result);
2888 if (TREE_SIDE_EFFECTS (omitted2))
2889 t = build2 (COMPOUND_EXPR, type, omitted2, t);
2890 if (TREE_SIDE_EFFECTS (omitted1))
2891 t = build2 (COMPOUND_EXPR, type, omitted1, t);
2893 return TREE_CODE (t) != COMPOUND_EXPR ? non_lvalue (t) : t;
2897 /* Return a simplified tree node for the truth-negation of ARG. This
2898 never alters ARG itself. We assume that ARG is an operation that
2899 returns a truth value (0 or 1).
2901 FIXME: one would think we would fold the result, but it causes
2902 problems with the dominator optimizer. */
2904 invert_truthvalue (tree arg)
2906 tree type = TREE_TYPE (arg);
2907 enum tree_code code = TREE_CODE (arg);
2909 if (code == ERROR_MARK)
2912 /* If this is a comparison, we can simply invert it, except for
2913 floating-point non-equality comparisons, in which case we just
2914 enclose a TRUTH_NOT_EXPR around what we have. */
2916 if (TREE_CODE_CLASS (code) == tcc_comparison)
2918 tree op_type = TREE_TYPE (TREE_OPERAND (arg, 0));
2919 if (FLOAT_TYPE_P (op_type)
2920 && flag_trapping_math
2921 && code != ORDERED_EXPR && code != UNORDERED_EXPR
2922 && code != NE_EXPR && code != EQ_EXPR)
2923 return build1 (TRUTH_NOT_EXPR, type, arg);
2926 code = invert_tree_comparison (code,
2927 HONOR_NANS (TYPE_MODE (op_type)));
2928 if (code == ERROR_MARK)
2929 return build1 (TRUTH_NOT_EXPR, type, arg);
2931 return build2 (code, type,
2932 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
2939 return constant_boolean_node (integer_zerop (arg), type);
2941 case TRUTH_AND_EXPR:
2942 return build2 (TRUTH_OR_EXPR, type,
2943 invert_truthvalue (TREE_OPERAND (arg, 0)),
2944 invert_truthvalue (TREE_OPERAND (arg, 1)));
2947 return build2 (TRUTH_AND_EXPR, type,
2948 invert_truthvalue (TREE_OPERAND (arg, 0)),
2949 invert_truthvalue (TREE_OPERAND (arg, 1)));
2951 case TRUTH_XOR_EXPR:
2952 /* Here we can invert either operand. We invert the first operand
2953 unless the second operand is a TRUTH_NOT_EXPR in which case our
2954 result is the XOR of the first operand with the inside of the
2955 negation of the second operand. */
2957 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
2958 return build2 (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
2959 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
2961 return build2 (TRUTH_XOR_EXPR, type,
2962 invert_truthvalue (TREE_OPERAND (arg, 0)),
2963 TREE_OPERAND (arg, 1));
2965 case TRUTH_ANDIF_EXPR:
2966 return build2 (TRUTH_ORIF_EXPR, type,
2967 invert_truthvalue (TREE_OPERAND (arg, 0)),
2968 invert_truthvalue (TREE_OPERAND (arg, 1)));
2970 case TRUTH_ORIF_EXPR:
2971 return build2 (TRUTH_ANDIF_EXPR, type,
2972 invert_truthvalue (TREE_OPERAND (arg, 0)),
2973 invert_truthvalue (TREE_OPERAND (arg, 1)));
2975 case TRUTH_NOT_EXPR:
2976 return TREE_OPERAND (arg, 0);
2979 return build3 (COND_EXPR, type, TREE_OPERAND (arg, 0),
2980 invert_truthvalue (TREE_OPERAND (arg, 1)),
2981 invert_truthvalue (TREE_OPERAND (arg, 2)));
2984 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
2985 invert_truthvalue (TREE_OPERAND (arg, 1)));
2987 case NON_LVALUE_EXPR:
2988 return invert_truthvalue (TREE_OPERAND (arg, 0));
2991 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE)
2996 return build1 (TREE_CODE (arg), type,
2997 invert_truthvalue (TREE_OPERAND (arg, 0)));
3000 if (!integer_onep (TREE_OPERAND (arg, 1)))
3002 return build2 (EQ_EXPR, type, arg,
3003 fold_convert (type, integer_zero_node));
3006 return build1 (TRUTH_NOT_EXPR, type, arg);
3008 case CLEANUP_POINT_EXPR:
3009 return build1 (CLEANUP_POINT_EXPR, type,
3010 invert_truthvalue (TREE_OPERAND (arg, 0)));
3015 gcc_assert (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE);
3016 return build1 (TRUTH_NOT_EXPR, type, arg);
3019 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
3020 operands are another bit-wise operation with a common input. If so,
3021 distribute the bit operations to save an operation and possibly two if
3022 constants are involved. For example, convert
3023 (A | B) & (A | C) into A | (B & C)
3024 Further simplification will occur if B and C are constants.
3026 If this optimization cannot be done, 0 will be returned. */
3029 distribute_bit_expr (enum tree_code code, tree type, tree arg0, tree arg1)
3034 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3035 || TREE_CODE (arg0) == code
3036 || (TREE_CODE (arg0) != BIT_AND_EXPR
3037 && TREE_CODE (arg0) != BIT_IOR_EXPR))
3040 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
3042 common = TREE_OPERAND (arg0, 0);
3043 left = TREE_OPERAND (arg0, 1);
3044 right = TREE_OPERAND (arg1, 1);
3046 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
3048 common = TREE_OPERAND (arg0, 0);
3049 left = TREE_OPERAND (arg0, 1);
3050 right = TREE_OPERAND (arg1, 0);
3052 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
3054 common = TREE_OPERAND (arg0, 1);
3055 left = TREE_OPERAND (arg0, 0);
3056 right = TREE_OPERAND (arg1, 1);
3058 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
3060 common = TREE_OPERAND (arg0, 1);
3061 left = TREE_OPERAND (arg0, 0);
3062 right = TREE_OPERAND (arg1, 0);
3067 return fold (build2 (TREE_CODE (arg0), type, common,
3068 fold (build2 (code, type, left, right))));
3071 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
3072 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
3075 make_bit_field_ref (tree inner, tree type, int bitsize, int bitpos,
3082 tree size = TYPE_SIZE (TREE_TYPE (inner));
3083 if ((INTEGRAL_TYPE_P (TREE_TYPE (inner))
3084 || POINTER_TYPE_P (TREE_TYPE (inner)))
3085 && host_integerp (size, 0)
3086 && tree_low_cst (size, 0) == bitsize)
3087 return fold_convert (type, inner);
3090 result = build3 (BIT_FIELD_REF, type, inner,
3091 size_int (bitsize), bitsize_int (bitpos));
3093 BIT_FIELD_REF_UNSIGNED (result) = unsignedp;
3098 /* Optimize a bit-field compare.
3100 There are two cases: First is a compare against a constant and the
3101 second is a comparison of two items where the fields are at the same
3102 bit position relative to the start of a chunk (byte, halfword, word)
3103 large enough to contain it. In these cases we can avoid the shift
3104 implicit in bitfield extractions.
3106 For constants, we emit a compare of the shifted constant with the
3107 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
3108 compared. For two fields at the same position, we do the ANDs with the
3109 similar mask and compare the result of the ANDs.
3111 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
3112 COMPARE_TYPE is the type of the comparison, and LHS and RHS
3113 are the left and right operands of the comparison, respectively.
3115 If the optimization described above can be done, we return the resulting
3116 tree. Otherwise we return zero. */
3119 optimize_bit_field_compare (enum tree_code code, tree compare_type,
3122 HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
3123 tree type = TREE_TYPE (lhs);
3124 tree signed_type, unsigned_type;
3125 int const_p = TREE_CODE (rhs) == INTEGER_CST;
3126 enum machine_mode lmode, rmode, nmode;
3127 int lunsignedp, runsignedp;
3128 int lvolatilep = 0, rvolatilep = 0;
3129 tree linner, rinner = NULL_TREE;
3133 /* Get all the information about the extractions being done. If the bit size
3134 if the same as the size of the underlying object, we aren't doing an
3135 extraction at all and so can do nothing. We also don't want to
3136 do anything if the inner expression is a PLACEHOLDER_EXPR since we
3137 then will no longer be able to replace it. */
3138 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
3139 &lunsignedp, &lvolatilep, false);
3140 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
3141 || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
3146 /* If this is not a constant, we can only do something if bit positions,
3147 sizes, and signedness are the same. */
3148 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
3149 &runsignedp, &rvolatilep, false);
3151 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
3152 || lunsignedp != runsignedp || offset != 0
3153 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
3157 /* See if we can find a mode to refer to this field. We should be able to,
3158 but fail if we can't. */
3159 nmode = get_best_mode (lbitsize, lbitpos,
3160 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
3161 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
3162 TYPE_ALIGN (TREE_TYPE (rinner))),
3163 word_mode, lvolatilep || rvolatilep);
3164 if (nmode == VOIDmode)
3167 /* Set signed and unsigned types of the precision of this mode for the
3169 signed_type = lang_hooks.types.type_for_mode (nmode, 0);
3170 unsigned_type = lang_hooks.types.type_for_mode (nmode, 1);
3172 /* Compute the bit position and size for the new reference and our offset
3173 within it. If the new reference is the same size as the original, we
3174 won't optimize anything, so return zero. */
3175 nbitsize = GET_MODE_BITSIZE (nmode);
3176 nbitpos = lbitpos & ~ (nbitsize - 1);
3178 if (nbitsize == lbitsize)
3181 if (BYTES_BIG_ENDIAN)
3182 lbitpos = nbitsize - lbitsize - lbitpos;
3184 /* Make the mask to be used against the extracted field. */
3185 mask = build_int_cst (unsigned_type, -1);
3186 mask = force_fit_type (mask, 0, false, false);
3187 mask = fold_convert (unsigned_type, mask);
3188 mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
3189 mask = const_binop (RSHIFT_EXPR, mask,
3190 size_int (nbitsize - lbitsize - lbitpos), 0);
3193 /* If not comparing with constant, just rework the comparison
3195 return build2 (code, compare_type,
3196 build2 (BIT_AND_EXPR, unsigned_type,
3197 make_bit_field_ref (linner, unsigned_type,
3198 nbitsize, nbitpos, 1),
3200 build2 (BIT_AND_EXPR, unsigned_type,
3201 make_bit_field_ref (rinner, unsigned_type,
3202 nbitsize, nbitpos, 1),
3205 /* Otherwise, we are handling the constant case. See if the constant is too
3206 big for the field. Warn and return a tree of for 0 (false) if so. We do
3207 this not only for its own sake, but to avoid having to test for this
3208 error case below. If we didn't, we might generate wrong code.
3210 For unsigned fields, the constant shifted right by the field length should
3211 be all zero. For signed fields, the high-order bits should agree with
3216 if (! integer_zerop (const_binop (RSHIFT_EXPR,
3217 fold_convert (unsigned_type, rhs),
3218 size_int (lbitsize), 0)))
3220 warning ("comparison is always %d due to width of bit-field",
3222 return constant_boolean_node (code == NE_EXPR, compare_type);
3227 tree tem = const_binop (RSHIFT_EXPR, fold_convert (signed_type, rhs),
3228 size_int (lbitsize - 1), 0);
3229 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
3231 warning ("comparison is always %d due to width of bit-field",
3233 return constant_boolean_node (code == NE_EXPR, compare_type);
3237 /* Single-bit compares should always be against zero. */
3238 if (lbitsize == 1 && ! integer_zerop (rhs))
3240 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
3241 rhs = fold_convert (type, integer_zero_node);
3244 /* Make a new bitfield reference, shift the constant over the
3245 appropriate number of bits and mask it with the computed mask
3246 (in case this was a signed field). If we changed it, make a new one. */
3247 lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1);
3250 TREE_SIDE_EFFECTS (lhs) = 1;
3251 TREE_THIS_VOLATILE (lhs) = 1;
3254 rhs = fold (const_binop (BIT_AND_EXPR,
3255 const_binop (LSHIFT_EXPR,
3256 fold_convert (unsigned_type, rhs),
3257 size_int (lbitpos), 0),
3260 return build2 (code, compare_type,
3261 build2 (BIT_AND_EXPR, unsigned_type, lhs, mask),
3265 /* Subroutine for fold_truthop: decode a field reference.
3267 If EXP is a comparison reference, we return the innermost reference.
3269 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
3270 set to the starting bit number.
3272 If the innermost field can be completely contained in a mode-sized
3273 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
3275 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
3276 otherwise it is not changed.
3278 *PUNSIGNEDP is set to the signedness of the field.
3280 *PMASK is set to the mask used. This is either contained in a
3281 BIT_AND_EXPR or derived from the width of the field.
3283 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
3285 Return 0 if this is not a component reference or is one that we can't
3286 do anything with. */
3289 decode_field_reference (tree exp, HOST_WIDE_INT *pbitsize,
3290 HOST_WIDE_INT *pbitpos, enum machine_mode *pmode,
3291 int *punsignedp, int *pvolatilep,
3292 tree *pmask, tree *pand_mask)
3294 tree outer_type = 0;
3296 tree mask, inner, offset;
3298 unsigned int precision;
3300 /* All the optimizations using this function assume integer fields.
3301 There are problems with FP fields since the type_for_size call
3302 below can fail for, e.g., XFmode. */
3303 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
3306 /* We are interested in the bare arrangement of bits, so strip everything
3307 that doesn't affect the machine mode. However, record the type of the
3308 outermost expression if it may matter below. */
3309 if (TREE_CODE (exp) == NOP_EXPR
3310 || TREE_CODE (exp) == CONVERT_EXPR
3311 || TREE_CODE (exp) == NON_LVALUE_EXPR)
3312 outer_type = TREE_TYPE (exp);
3315 if (TREE_CODE (exp) == BIT_AND_EXPR)
3317 and_mask = TREE_OPERAND (exp, 1);
3318 exp = TREE_OPERAND (exp, 0);
3319 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
3320 if (TREE_CODE (and_mask) != INTEGER_CST)
3324 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
3325 punsignedp, pvolatilep, false);
3326 if ((inner == exp && and_mask == 0)
3327 || *pbitsize < 0 || offset != 0
3328 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
3331 /* If the number of bits in the reference is the same as the bitsize of
3332 the outer type, then the outer type gives the signedness. Otherwise
3333 (in case of a small bitfield) the signedness is unchanged. */
3334 if (outer_type && *pbitsize == TYPE_PRECISION (outer_type))
3335 *punsignedp = TYPE_UNSIGNED (outer_type);
3337 /* Compute the mask to access the bitfield. */
3338 unsigned_type = lang_hooks.types.type_for_size (*pbitsize, 1);
3339 precision = TYPE_PRECISION (unsigned_type);
3341 mask = build_int_cst (unsigned_type, -1);
3342 mask = force_fit_type (mask, 0, false, false);
3344 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3345 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3347 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
3349 mask = fold (build2 (BIT_AND_EXPR, unsigned_type,
3350 fold_convert (unsigned_type, and_mask), mask));
3353 *pand_mask = and_mask;
3357 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
3361 all_ones_mask_p (tree mask, int size)
3363 tree type = TREE_TYPE (mask);
3364 unsigned int precision = TYPE_PRECISION (type);
3367 tmask = build_int_cst (lang_hooks.types.signed_type (type), -1);
3368 tmask = force_fit_type (tmask, 0, false, false);
3371 tree_int_cst_equal (mask,
3372 const_binop (RSHIFT_EXPR,
3373 const_binop (LSHIFT_EXPR, tmask,
3374 size_int (precision - size),
3376 size_int (precision - size), 0));
3379 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
3380 represents the sign bit of EXP's type. If EXP represents a sign
3381 or zero extension, also test VAL against the unextended type.
3382 The return value is the (sub)expression whose sign bit is VAL,
3383 or NULL_TREE otherwise. */
3386 sign_bit_p (tree exp, tree val)
3388 unsigned HOST_WIDE_INT mask_lo, lo;
3389 HOST_WIDE_INT mask_hi, hi;
3393 /* Tree EXP must have an integral type. */
3394 t = TREE_TYPE (exp);
3395 if (! INTEGRAL_TYPE_P (t))
3398 /* Tree VAL must be an integer constant. */
3399 if (TREE_CODE (val) != INTEGER_CST
3400 || TREE_CONSTANT_OVERFLOW (val))
3403 width = TYPE_PRECISION (t);
3404 if (width > HOST_BITS_PER_WIDE_INT)
3406 hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1);
3409 mask_hi = ((unsigned HOST_WIDE_INT) -1
3410 >> (2 * HOST_BITS_PER_WIDE_INT - width));
3416 lo = (unsigned HOST_WIDE_INT) 1 << (width - 1);
3419 mask_lo = ((unsigned HOST_WIDE_INT) -1
3420 >> (HOST_BITS_PER_WIDE_INT - width));
3423 /* We mask off those bits beyond TREE_TYPE (exp) so that we can
3424 treat VAL as if it were unsigned. */
3425 if ((TREE_INT_CST_HIGH (val) & mask_hi) == hi
3426 && (TREE_INT_CST_LOW (val) & mask_lo) == lo)
3429 /* Handle extension from a narrower type. */
3430 if (TREE_CODE (exp) == NOP_EXPR
3431 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width)
3432 return sign_bit_p (TREE_OPERAND (exp, 0), val);
3437 /* Subroutine for fold_truthop: determine if an operand is simple enough
3438 to be evaluated unconditionally. */
3441 simple_operand_p (tree exp)
3443 /* Strip any conversions that don't change the machine mode. */
3446 return (CONSTANT_CLASS_P (exp)
3447 || TREE_CODE (exp) == SSA_NAME
3449 && ! TREE_ADDRESSABLE (exp)
3450 && ! TREE_THIS_VOLATILE (exp)
3451 && ! DECL_NONLOCAL (exp)
3452 /* Don't regard global variables as simple. They may be
3453 allocated in ways unknown to the compiler (shared memory,
3454 #pragma weak, etc). */
3455 && ! TREE_PUBLIC (exp)
3456 && ! DECL_EXTERNAL (exp)
3457 /* Loading a static variable is unduly expensive, but global
3458 registers aren't expensive. */
3459 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
3462 /* The following functions are subroutines to fold_range_test and allow it to
3463 try to change a logical combination of comparisons into a range test.
3466 X == 2 || X == 3 || X == 4 || X == 5
3470 (unsigned) (X - 2) <= 3
3472 We describe each set of comparisons as being either inside or outside
3473 a range, using a variable named like IN_P, and then describe the
3474 range with a lower and upper bound. If one of the bounds is omitted,
3475 it represents either the highest or lowest value of the type.
3477 In the comments below, we represent a range by two numbers in brackets
3478 preceded by a "+" to designate being inside that range, or a "-" to
3479 designate being outside that range, so the condition can be inverted by
3480 flipping the prefix. An omitted bound is represented by a "-". For
3481 example, "- [-, 10]" means being outside the range starting at the lowest
3482 possible value and ending at 10, in other words, being greater than 10.
3483 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
3486 We set up things so that the missing bounds are handled in a consistent
3487 manner so neither a missing bound nor "true" and "false" need to be
3488 handled using a special case. */
3490 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
3491 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
3492 and UPPER1_P are nonzero if the respective argument is an upper bound
3493 and zero for a lower. TYPE, if nonzero, is the type of the result; it
3494 must be specified for a comparison. ARG1 will be converted to ARG0's
3495 type if both are specified. */
3498 range_binop (enum tree_code code, tree type, tree arg0, int upper0_p,
3499 tree arg1, int upper1_p)
3505 /* If neither arg represents infinity, do the normal operation.
3506 Else, if not a comparison, return infinity. Else handle the special
3507 comparison rules. Note that most of the cases below won't occur, but
3508 are handled for consistency. */
3510 if (arg0 != 0 && arg1 != 0)
3512 tem = fold (build2 (code, type != 0 ? type : TREE_TYPE (arg0),
3513 arg0, fold_convert (TREE_TYPE (arg0), arg1)));
3515 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
3518 if (TREE_CODE_CLASS (code) != tcc_comparison)
3521 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
3522 for neither. In real maths, we cannot assume open ended ranges are
3523 the same. But, this is computer arithmetic, where numbers are finite.
3524 We can therefore make the transformation of any unbounded range with
3525 the value Z, Z being greater than any representable number. This permits
3526 us to treat unbounded ranges as equal. */
3527 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
3528 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
3532 result = sgn0 == sgn1;
3535 result = sgn0 != sgn1;
3538 result = sgn0 < sgn1;
3541 result = sgn0 <= sgn1;
3544 result = sgn0 > sgn1;
3547 result = sgn0 >= sgn1;
3553 return constant_boolean_node (result, type);
3556 /* Given EXP, a logical expression, set the range it is testing into
3557 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
3558 actually being tested. *PLOW and *PHIGH will be made of the same type
3559 as the returned expression. If EXP is not a comparison, we will most
3560 likely not be returning a useful value and range. */
3563 make_range (tree exp, int *pin_p, tree *plow, tree *phigh)
3565 enum tree_code code;
3566 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
3567 tree exp_type = NULL_TREE, arg0_type = NULL_TREE;
3569 tree low, high, n_low, n_high;
3571 /* Start with simply saying "EXP != 0" and then look at the code of EXP
3572 and see if we can refine the range. Some of the cases below may not
3573 happen, but it doesn't seem worth worrying about this. We "continue"
3574 the outer loop when we've changed something; otherwise we "break"
3575 the switch, which will "break" the while. */
3578 low = high = fold_convert (TREE_TYPE (exp), integer_zero_node);
3582 code = TREE_CODE (exp);
3583 exp_type = TREE_TYPE (exp);
3585 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
3587 if (TREE_CODE_LENGTH (code) > 0)
3588 arg0 = TREE_OPERAND (exp, 0);
3589 if (TREE_CODE_CLASS (code) == tcc_comparison
3590 || TREE_CODE_CLASS (code) == tcc_unary
3591 || TREE_CODE_CLASS (code) == tcc_binary)
3592 arg0_type = TREE_TYPE (arg0);
3593 if (TREE_CODE_CLASS (code) == tcc_binary
3594 || TREE_CODE_CLASS (code) == tcc_comparison
3595 || (TREE_CODE_CLASS (code) == tcc_expression
3596 && TREE_CODE_LENGTH (code) > 1))
3597 arg1 = TREE_OPERAND (exp, 1);
3602 case TRUTH_NOT_EXPR:
3603 in_p = ! in_p, exp = arg0;
3606 case EQ_EXPR: case NE_EXPR:
3607 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
3608 /* We can only do something if the range is testing for zero
3609 and if the second operand is an integer constant. Note that
3610 saying something is "in" the range we make is done by
3611 complementing IN_P since it will set in the initial case of
3612 being not equal to zero; "out" is leaving it alone. */
3613 if (low == 0 || high == 0
3614 || ! integer_zerop (low) || ! integer_zerop (high)
3615 || TREE_CODE (arg1) != INTEGER_CST)
3620 case NE_EXPR: /* - [c, c] */
3623 case EQ_EXPR: /* + [c, c] */
3624 in_p = ! in_p, low = high = arg1;
3626 case GT_EXPR: /* - [-, c] */
3627 low = 0, high = arg1;
3629 case GE_EXPR: /* + [c, -] */
3630 in_p = ! in_p, low = arg1, high = 0;
3632 case LT_EXPR: /* - [c, -] */
3633 low = arg1, high = 0;
3635 case LE_EXPR: /* + [-, c] */
3636 in_p = ! in_p, low = 0, high = arg1;
3642 /* If this is an unsigned comparison, we also know that EXP is
3643 greater than or equal to zero. We base the range tests we make
3644 on that fact, so we record it here so we can parse existing
3645 range tests. We test arg0_type since often the return type
3646 of, e.g. EQ_EXPR, is boolean. */
3647 if (TYPE_UNSIGNED (arg0_type) && (low == 0 || high == 0))
3649 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3651 fold_convert (arg0_type, integer_zero_node),
3655 in_p = n_in_p, low = n_low, high = n_high;
3657 /* If the high bound is missing, but we have a nonzero low
3658 bound, reverse the range so it goes from zero to the low bound
3660 if (high == 0 && low && ! integer_zerop (low))
3663 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
3664 integer_one_node, 0);
3665 low = fold_convert (arg0_type, integer_zero_node);
3673 /* (-x) IN [a,b] -> x in [-b, -a] */
3674 n_low = range_binop (MINUS_EXPR, exp_type,
3675 fold_convert (exp_type, integer_zero_node),
3677 n_high = range_binop (MINUS_EXPR, exp_type,
3678 fold_convert (exp_type, integer_zero_node),
3680 low = n_low, high = n_high;
3686 exp = build2 (MINUS_EXPR, exp_type, negate_expr (arg0),
3687 fold_convert (exp_type, integer_one_node));
3690 case PLUS_EXPR: case MINUS_EXPR:
3691 if (TREE_CODE (arg1) != INTEGER_CST)
3694 /* If EXP is signed, any overflow in the computation is undefined,
3695 so we don't worry about it so long as our computations on
3696 the bounds don't overflow. For unsigned, overflow is defined
3697 and this is exactly the right thing. */
3698 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3699 arg0_type, low, 0, arg1, 0);
3700 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3701 arg0_type, high, 1, arg1, 0);
3702 if ((n_low != 0 && TREE_OVERFLOW (n_low))
3703 || (n_high != 0 && TREE_OVERFLOW (n_high)))
3706 /* Check for an unsigned range which has wrapped around the maximum
3707 value thus making n_high < n_low, and normalize it. */
3708 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
3710 low = range_binop (PLUS_EXPR, arg0_type, n_high, 0,
3711 integer_one_node, 0);
3712 high = range_binop (MINUS_EXPR, arg0_type, n_low, 0,
3713 integer_one_node, 0);
3715 /* If the range is of the form +/- [ x+1, x ], we won't
3716 be able to normalize it. But then, it represents the
3717 whole range or the empty set, so make it
3719 if (tree_int_cst_equal (n_low, low)
3720 && tree_int_cst_equal (n_high, high))
3726 low = n_low, high = n_high;
3731 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
3732 if (TYPE_PRECISION (arg0_type) > TYPE_PRECISION (exp_type))
3735 if (! INTEGRAL_TYPE_P (arg0_type)
3736 || (low != 0 && ! int_fits_type_p (low, arg0_type))
3737 || (high != 0 && ! int_fits_type_p (high, arg0_type)))
3740 n_low = low, n_high = high;
3743 n_low = fold_convert (arg0_type, n_low);
3746 n_high = fold_convert (arg0_type, n_high);
3749 /* If we're converting arg0 from an unsigned type, to exp,
3750 a signed type, we will be doing the comparison as unsigned.
3751 The tests above have already verified that LOW and HIGH
3754 So we have to ensure that we will handle large unsigned
3755 values the same way that the current signed bounds treat
3758 if (!TYPE_UNSIGNED (exp_type) && TYPE_UNSIGNED (arg0_type))
3761 tree equiv_type = lang_hooks.types.type_for_mode
3762 (TYPE_MODE (arg0_type), 1);
3764 /* A range without an upper bound is, naturally, unbounded.
3765 Since convert would have cropped a very large value, use
3766 the max value for the destination type. */
3768 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
3769 : TYPE_MAX_VALUE (arg0_type);
3771 if (TYPE_PRECISION (exp_type) == TYPE_PRECISION (arg0_type))
3772 high_positive = fold (build2 (RSHIFT_EXPR, arg0_type,
3773 fold_convert (arg0_type,
3775 fold_convert (arg0_type,
3776 integer_one_node)));
3778 /* If the low bound is specified, "and" the range with the
3779 range for which the original unsigned value will be
3783 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3784 1, n_low, n_high, 1,
3785 fold_convert (arg0_type,
3790 in_p = (n_in_p == in_p);
3794 /* Otherwise, "or" the range with the range of the input
3795 that will be interpreted as negative. */
3796 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3797 0, n_low, n_high, 1,
3798 fold_convert (arg0_type,
3803 in_p = (in_p != n_in_p);
3808 low = n_low, high = n_high;
3818 /* If EXP is a constant, we can evaluate whether this is true or false. */
3819 if (TREE_CODE (exp) == INTEGER_CST)
3821 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
3823 && integer_onep (range_binop (LE_EXPR, integer_type_node,
3829 *pin_p = in_p, *plow = low, *phigh = high;
3833 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3834 type, TYPE, return an expression to test if EXP is in (or out of, depending
3835 on IN_P) the range. Return 0 if the test couldn't be created. */
3838 build_range_check (tree type, tree exp, int in_p, tree low, tree high)
3840 tree etype = TREE_TYPE (exp);
3845 value = build_range_check (type, exp, 1, low, high);
3847 return invert_truthvalue (value);
3852 if (low == 0 && high == 0)
3853 return fold_convert (type, integer_one_node);
3856 return fold (build2 (LE_EXPR, type, exp, high));
3859 return fold (build2 (GE_EXPR, type, exp, low));
3861 if (operand_equal_p (low, high, 0))
3862 return fold (build2 (EQ_EXPR, type, exp, low));
3864 if (integer_zerop (low))
3866 if (! TYPE_UNSIGNED (etype))
3868 etype = lang_hooks.types.unsigned_type (etype);
3869 high = fold_convert (etype, high);
3870 exp = fold_convert (etype, exp);
3872 return build_range_check (type, exp, 1, 0, high);
3875 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
3876 if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST)
3878 unsigned HOST_WIDE_INT lo;
3882 prec = TYPE_PRECISION (etype);
3883 if (prec <= HOST_BITS_PER_WIDE_INT)
3886 lo = ((unsigned HOST_WIDE_INT) 1 << (prec - 1)) - 1;
3890 hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1;
3891 lo = (unsigned HOST_WIDE_INT) -1;
3894 if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo)
3896 if (TYPE_UNSIGNED (etype))
3898 etype = lang_hooks.types.signed_type (etype);
3899 exp = fold_convert (etype, exp);
3901 return fold (build2 (GT_EXPR, type, exp,
3902 fold_convert (etype, integer_zero_node)));
3906 value = const_binop (MINUS_EXPR, high, low, 0);
3907 if (value != 0 && TREE_OVERFLOW (value) && ! TYPE_UNSIGNED (etype))
3909 tree utype, minv, maxv;
3911 /* Check if (unsigned) INT_MAX + 1 == (unsigned) INT_MIN
3912 for the type in question, as we rely on this here. */
3913 switch (TREE_CODE (etype))
3918 utype = lang_hooks.types.unsigned_type (etype);
3919 maxv = fold_convert (utype, TYPE_MAX_VALUE (etype));
3920 maxv = range_binop (PLUS_EXPR, NULL_TREE, maxv, 1,
3921 integer_one_node, 1);
3922 minv = fold_convert (utype, TYPE_MIN_VALUE (etype));
3923 if (integer_zerop (range_binop (NE_EXPR, integer_type_node,
3927 high = fold_convert (etype, high);
3928 low = fold_convert (etype, low);
3929 exp = fold_convert (etype, exp);
3930 value = const_binop (MINUS_EXPR, high, low, 0);
3938 if (value != 0 && ! TREE_OVERFLOW (value))
3939 return build_range_check (type,
3940 fold (build2 (MINUS_EXPR, etype, exp, low)),
3941 1, fold_convert (etype, integer_zero_node),
3947 /* Given two ranges, see if we can merge them into one. Return 1 if we
3948 can, 0 if we can't. Set the output range into the specified parameters. */
3951 merge_ranges (int *pin_p, tree *plow, tree *phigh, int in0_p, tree low0,
3952 tree high0, int in1_p, tree low1, tree high1)
3960 int lowequal = ((low0 == 0 && low1 == 0)
3961 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3962 low0, 0, low1, 0)));
3963 int highequal = ((high0 == 0 && high1 == 0)
3964 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3965 high0, 1, high1, 1)));
3967 /* Make range 0 be the range that starts first, or ends last if they
3968 start at the same value. Swap them if it isn't. */
3969 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
3972 && integer_onep (range_binop (GT_EXPR, integer_type_node,
3973 high1, 1, high0, 1))))
3975 temp = in0_p, in0_p = in1_p, in1_p = temp;
3976 tem = low0, low0 = low1, low1 = tem;
3977 tem = high0, high0 = high1, high1 = tem;
3980 /* Now flag two cases, whether the ranges are disjoint or whether the
3981 second range is totally subsumed in the first. Note that the tests
3982 below are simplified by the ones above. */
3983 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
3984 high0, 1, low1, 0));
3985 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
3986 high1, 1, high0, 1));
3988 /* We now have four cases, depending on whether we are including or
3989 excluding the two ranges. */
3992 /* If they don't overlap, the result is false. If the second range
3993 is a subset it is the result. Otherwise, the range is from the start
3994 of the second to the end of the first. */
3996 in_p = 0, low = high = 0;
3998 in_p = 1, low = low1, high = high1;
4000 in_p = 1, low = low1, high = high0;
4003 else if (in0_p && ! in1_p)
4005 /* If they don't overlap, the result is the first range. If they are
4006 equal, the result is false. If the second range is a subset of the
4007 first, and the ranges begin at the same place, we go from just after
4008 the end of the first range to the end of the second. If the second
4009 range is not a subset of the first, or if it is a subset and both
4010 ranges end at the same place, the range starts at the start of the
4011 first range and ends just before the second range.
4012 Otherwise, we can't describe this as a single range. */
4014 in_p = 1, low = low0, high = high0;
4015 else if (lowequal && highequal)
4016 in_p = 0, low = high = 0;
4017 else if (subset && lowequal)
4019 in_p = 1, high = high0;
4020 low = range_binop (PLUS_EXPR, NULL_TREE, high1, 0,
4021 integer_one_node, 0);
4023 else if (! subset || highequal)
4025 in_p = 1, low = low0;
4026 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
4027 integer_one_node, 0);
4033 else if (! in0_p && in1_p)
4035 /* If they don't overlap, the result is the second range. If the second
4036 is a subset of the first, the result is false. Otherwise,
4037 the range starts just after the first range and ends at the
4038 end of the second. */
4040 in_p = 1, low = low1, high = high1;
4041 else if (subset || highequal)
4042 in_p = 0, low = high = 0;
4045 in_p = 1, high = high1;
4046 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
4047 integer_one_node, 0);
4053 /* The case where we are excluding both ranges. Here the complex case
4054 is if they don't overlap. In that case, the only time we have a
4055 range is if they are adjacent. If the second is a subset of the
4056 first, the result is the first. Otherwise, the range to exclude
4057 starts at the beginning of the first range and ends at the end of the
4061 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
4062 range_binop (PLUS_EXPR, NULL_TREE,
4064 integer_one_node, 1),
4066 in_p = 0, low = low0, high = high1;
4069 /* Canonicalize - [min, x] into - [-, x]. */
4070 if (low0 && TREE_CODE (low0) == INTEGER_CST)
4071 switch (TREE_CODE (TREE_TYPE (low0)))
4074 if (TYPE_PRECISION (TREE_TYPE (low0))
4075 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (low0))))
4080 if (tree_int_cst_equal (low0,
4081 TYPE_MIN_VALUE (TREE_TYPE (low0))))
4085 if (TYPE_UNSIGNED (TREE_TYPE (low0))
4086 && integer_zerop (low0))
4093 /* Canonicalize - [x, max] into - [x, -]. */
4094 if (high1 && TREE_CODE (high1) == INTEGER_CST)
4095 switch (TREE_CODE (TREE_TYPE (high1)))
4098 if (TYPE_PRECISION (TREE_TYPE (high1))
4099 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (high1))))
4104 if (tree_int_cst_equal (high1,
4105 TYPE_MAX_VALUE (TREE_TYPE (high1))))
4109 if (TYPE_UNSIGNED (TREE_TYPE (high1))
4110 && integer_zerop (range_binop (PLUS_EXPR, NULL_TREE,
4112 integer_one_node, 1)))
4119 /* The ranges might be also adjacent between the maximum and
4120 minimum values of the given type. For
4121 - [{min,-}, x] and - [y, {max,-}] ranges where x + 1 < y
4122 return + [x + 1, y - 1]. */
4123 if (low0 == 0 && high1 == 0)
4125 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
4126 integer_one_node, 1);
4127 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
4128 integer_one_node, 0);
4129 if (low == 0 || high == 0)
4139 in_p = 0, low = low0, high = high0;
4141 in_p = 0, low = low0, high = high1;
4144 *pin_p = in_p, *plow = low, *phigh = high;
4149 /* Subroutine of fold, looking inside expressions of the form
4150 A op B ? A : C, where ARG0, ARG1 and ARG2 are the three operands
4151 of the COND_EXPR. This function is being used also to optimize
4152 A op B ? C : A, by reversing the comparison first.
4154 Return a folded expression whose code is not a COND_EXPR
4155 anymore, or NULL_TREE if no folding opportunity is found. */
4158 fold_cond_expr_with_comparison (tree type, tree arg0, tree arg1, tree arg2)
4160 enum tree_code comp_code = TREE_CODE (arg0);
4161 tree arg00 = TREE_OPERAND (arg0, 0);
4162 tree arg01 = TREE_OPERAND (arg0, 1);
4163 tree arg1_type = TREE_TYPE (arg1);
4169 /* If we have A op 0 ? A : -A, consider applying the following
4172 A == 0? A : -A same as -A
4173 A != 0? A : -A same as A
4174 A >= 0? A : -A same as abs (A)
4175 A > 0? A : -A same as abs (A)
4176 A <= 0? A : -A same as -abs (A)
4177 A < 0? A : -A same as -abs (A)
4179 None of these transformations work for modes with signed
4180 zeros. If A is +/-0, the first two transformations will
4181 change the sign of the result (from +0 to -0, or vice
4182 versa). The last four will fix the sign of the result,
4183 even though the original expressions could be positive or
4184 negative, depending on the sign of A.
4186 Note that all these transformations are correct if A is
4187 NaN, since the two alternatives (A and -A) are also NaNs. */
4188 if ((FLOAT_TYPE_P (TREE_TYPE (arg01))
4189 ? real_zerop (arg01)
4190 : integer_zerop (arg01))
4191 && TREE_CODE (arg2) == NEGATE_EXPR
4192 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
4197 tem = fold_convert (arg1_type, arg1);
4198 return pedantic_non_lvalue (fold_convert (type, negate_expr (tem)));
4201 return pedantic_non_lvalue (fold_convert (type, arg1));
4204 if (flag_trapping_math)
4209 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
4210 arg1 = fold_convert (lang_hooks.types.signed_type
4211 (TREE_TYPE (arg1)), arg1);
4212 tem = fold (build1 (ABS_EXPR, TREE_TYPE (arg1), arg1));
4213 return pedantic_non_lvalue (fold_convert (type, tem));
4216 if (flag_trapping_math)
4220 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
4221 arg1 = fold_convert (lang_hooks.types.signed_type
4222 (TREE_TYPE (arg1)), arg1);
4223 tem = fold (build1 (ABS_EXPR, TREE_TYPE (arg1), arg1));
4224 return negate_expr (fold_convert (type, tem));
4226 gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
4230 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
4231 A == 0 ? A : 0 is always 0 unless A is -0. Note that
4232 both transformations are correct when A is NaN: A != 0
4233 is then true, and A == 0 is false. */
4235 if (integer_zerop (arg01) && integer_zerop (arg2))
4237 if (comp_code == NE_EXPR)
4238 return pedantic_non_lvalue (fold_convert (type, arg1));
4239 else if (comp_code == EQ_EXPR)
4240 return fold_convert (type, integer_zero_node);
4243 /* Try some transformations of A op B ? A : B.
4245 A == B? A : B same as B
4246 A != B? A : B same as A
4247 A >= B? A : B same as max (A, B)
4248 A > B? A : B same as max (B, A)
4249 A <= B? A : B same as min (A, B)
4250 A < B? A : B same as min (B, A)
4252 As above, these transformations don't work in the presence
4253 of signed zeros. For example, if A and B are zeros of
4254 opposite sign, the first two transformations will change
4255 the sign of the result. In the last four, the original
4256 expressions give different results for (A=+0, B=-0) and
4257 (A=-0, B=+0), but the transformed expressions do not.
4259 The first two transformations are correct if either A or B
4260 is a NaN. In the first transformation, the condition will
4261 be false, and B will indeed be chosen. In the case of the
4262 second transformation, the condition A != B will be true,
4263 and A will be chosen.
4265 The conversions to max() and min() are not correct if B is
4266 a number and A is not. The conditions in the original
4267 expressions will be false, so all four give B. The min()
4268 and max() versions would give a NaN instead. */
4269 if (operand_equal_for_comparison_p (arg01, arg2, arg00))
4271 tree comp_op0 = arg00;
4272 tree comp_op1 = arg01;
4273 tree comp_type = TREE_TYPE (comp_op0);
4275 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
4276 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
4286 return pedantic_non_lvalue (fold_convert (type, arg2));
4288 return pedantic_non_lvalue (fold_convert (type, arg1));
4293 /* In C++ a ?: expression can be an lvalue, so put the
4294 operand which will be used if they are equal first
4295 so that we can convert this back to the
4296 corresponding COND_EXPR. */
4297 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4299 comp_op0 = fold_convert (comp_type, comp_op0);
4300 comp_op1 = fold_convert (comp_type, comp_op1);
4301 tem = (comp_code == LE_EXPR || comp_code == UNLE_EXPR)
4302 ? fold (build2 (MIN_EXPR, comp_type, comp_op0, comp_op1))
4303 : fold (build2 (MIN_EXPR, comp_type, comp_op1, comp_op0));
4304 return pedantic_non_lvalue (fold_convert (type, tem));
4311 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4313 comp_op0 = fold_convert (comp_type, comp_op0);
4314 comp_op1 = fold_convert (comp_type, comp_op1);
4315 tem = (comp_code == GE_EXPR || comp_code == UNGE_EXPR)
4316 ? fold (build2 (MAX_EXPR, comp_type, comp_op0, comp_op1))
4317 : fold (build2 (MAX_EXPR, comp_type, comp_op1, comp_op0));
4318 return pedantic_non_lvalue (fold_convert (type, tem));
4322 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4323 return pedantic_non_lvalue (fold_convert (type, arg2));
4326 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4327 return pedantic_non_lvalue (fold_convert (type, arg1));
4330 gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
4335 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
4336 we might still be able to simplify this. For example,
4337 if C1 is one less or one more than C2, this might have started
4338 out as a MIN or MAX and been transformed by this function.
4339 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
4341 if (INTEGRAL_TYPE_P (type)
4342 && TREE_CODE (arg01) == INTEGER_CST
4343 && TREE_CODE (arg2) == INTEGER_CST)
4347 /* We can replace A with C1 in this case. */
4348 arg1 = fold_convert (type, arg01);
4349 return fold (build3 (COND_EXPR, type, arg0, arg1, arg2));
4352 /* If C1 is C2 + 1, this is min(A, C2). */
4353 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
4355 && operand_equal_p (arg01,
4356 const_binop (PLUS_EXPR, arg2,
4357 integer_one_node, 0),
4359 return pedantic_non_lvalue (fold (build2 (MIN_EXPR,
4360 type, arg1, arg2)));
4364 /* If C1 is C2 - 1, this is min(A, C2). */
4365 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
4367 && operand_equal_p (arg01,
4368 const_binop (MINUS_EXPR, arg2,
4369 integer_one_node, 0),
4371 return pedantic_non_lvalue (fold (build2 (MIN_EXPR,
4372 type, arg1, arg2)));
4376 /* If C1 is C2 - 1, this is max(A, C2). */
4377 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
4379 && operand_equal_p (arg01,
4380 const_binop (MINUS_EXPR, arg2,
4381 integer_one_node, 0),
4383 return pedantic_non_lvalue (fold (build2 (MAX_EXPR,
4384 type, arg1, arg2)));
4388 /* If C1 is C2 + 1, this is max(A, C2). */
4389 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
4391 && operand_equal_p (arg01,
4392 const_binop (PLUS_EXPR, arg2,
4393 integer_one_node, 0),
4395 return pedantic_non_lvalue (fold (build2 (MAX_EXPR,
4396 type, arg1, arg2)));
4409 #ifndef LOGICAL_OP_NON_SHORT_CIRCUIT
4410 #define LOGICAL_OP_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
4413 /* EXP is some logical combination of boolean tests. See if we can
4414 merge it into some range test. Return the new tree if so. */
4417 fold_range_test (tree exp)
4419 int or_op = (TREE_CODE (exp) == TRUTH_ORIF_EXPR
4420 || TREE_CODE (exp) == TRUTH_OR_EXPR);
4421 int in0_p, in1_p, in_p;
4422 tree low0, low1, low, high0, high1, high;
4423 tree lhs = make_range (TREE_OPERAND (exp, 0), &in0_p, &low0, &high0);
4424 tree rhs = make_range (TREE_OPERAND (exp, 1), &in1_p, &low1, &high1);
4427 /* If this is an OR operation, invert both sides; we will invert
4428 again at the end. */
4430 in0_p = ! in0_p, in1_p = ! in1_p;
4432 /* If both expressions are the same, if we can merge the ranges, and we
4433 can build the range test, return it or it inverted. If one of the
4434 ranges is always true or always false, consider it to be the same
4435 expression as the other. */
4436 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
4437 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
4439 && 0 != (tem = (build_range_check (TREE_TYPE (exp),
4441 : rhs != 0 ? rhs : integer_zero_node,
4443 return or_op ? invert_truthvalue (tem) : tem;
4445 /* On machines where the branch cost is expensive, if this is a
4446 short-circuited branch and the underlying object on both sides
4447 is the same, make a non-short-circuit operation. */
4448 else if (LOGICAL_OP_NON_SHORT_CIRCUIT
4449 && lhs != 0 && rhs != 0
4450 && (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
4451 || TREE_CODE (exp) == TRUTH_ORIF_EXPR)
4452 && operand_equal_p (lhs, rhs, 0))
4454 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
4455 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
4456 which cases we can't do this. */
4457 if (simple_operand_p (lhs))
4458 return build2 (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
4459 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
4460 TREE_TYPE (exp), TREE_OPERAND (exp, 0),
4461 TREE_OPERAND (exp, 1));
4463 else if (lang_hooks.decls.global_bindings_p () == 0
4464 && ! CONTAINS_PLACEHOLDER_P (lhs))
4466 tree common = save_expr (lhs);
4468 if (0 != (lhs = build_range_check (TREE_TYPE (exp), common,
4469 or_op ? ! in0_p : in0_p,
4471 && (0 != (rhs = build_range_check (TREE_TYPE (exp), common,
4472 or_op ? ! in1_p : in1_p,
4474 return build2 (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
4475 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
4476 TREE_TYPE (exp), lhs, rhs);
4483 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
4484 bit value. Arrange things so the extra bits will be set to zero if and
4485 only if C is signed-extended to its full width. If MASK is nonzero,
4486 it is an INTEGER_CST that should be AND'ed with the extra bits. */
4489 unextend (tree c, int p, int unsignedp, tree mask)
4491 tree type = TREE_TYPE (c);
4492 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
4495 if (p == modesize || unsignedp)
4498 /* We work by getting just the sign bit into the low-order bit, then
4499 into the high-order bit, then sign-extend. We then XOR that value
4501 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
4502 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
4504 /* We must use a signed type in order to get an arithmetic right shift.
4505 However, we must also avoid introducing accidental overflows, so that
4506 a subsequent call to integer_zerop will work. Hence we must
4507 do the type conversion here. At this point, the constant is either
4508 zero or one, and the conversion to a signed type can never overflow.
4509 We could get an overflow if this conversion is done anywhere else. */
4510 if (TYPE_UNSIGNED (type))
4511 temp = fold_convert (lang_hooks.types.signed_type (type), temp);
4513 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
4514 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
4516 temp = const_binop (BIT_AND_EXPR, temp,
4517 fold_convert (TREE_TYPE (c), mask), 0);
4518 /* If necessary, convert the type back to match the type of C. */
4519 if (TYPE_UNSIGNED (type))
4520 temp = fold_convert (type, temp);
4522 return fold_convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
4525 /* Find ways of folding logical expressions of LHS and RHS:
4526 Try to merge two comparisons to the same innermost item.
4527 Look for range tests like "ch >= '0' && ch <= '9'".
4528 Look for combinations of simple terms on machines with expensive branches
4529 and evaluate the RHS unconditionally.
4531 For example, if we have p->a == 2 && p->b == 4 and we can make an
4532 object large enough to span both A and B, we can do this with a comparison
4533 against the object ANDed with the a mask.
4535 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
4536 operations to do this with one comparison.
4538 We check for both normal comparisons and the BIT_AND_EXPRs made this by
4539 function and the one above.
4541 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
4542 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
4544 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
4547 We return the simplified tree or 0 if no optimization is possible. */
4550 fold_truthop (enum tree_code code, tree truth_type, tree lhs, tree rhs)
4552 /* If this is the "or" of two comparisons, we can do something if
4553 the comparisons are NE_EXPR. If this is the "and", we can do something
4554 if the comparisons are EQ_EXPR. I.e.,
4555 (a->b == 2 && a->c == 4) can become (a->new == NEW).
4557 WANTED_CODE is this operation code. For single bit fields, we can
4558 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
4559 comparison for one-bit fields. */
4561 enum tree_code wanted_code;
4562 enum tree_code lcode, rcode;
4563 tree ll_arg, lr_arg, rl_arg, rr_arg;
4564 tree ll_inner, lr_inner, rl_inner, rr_inner;
4565 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
4566 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
4567 HOST_WIDE_INT xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
4568 HOST_WIDE_INT lnbitsize, lnbitpos, rnbitsize, rnbitpos;
4569 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
4570 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
4571 enum machine_mode lnmode, rnmode;
4572 tree ll_mask, lr_mask, rl_mask, rr_mask;
4573 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
4574 tree l_const, r_const;
4575 tree lntype, rntype, result;
4576 int first_bit, end_bit;
4579 /* Start by getting the comparison codes. Fail if anything is volatile.
4580 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
4581 it were surrounded with a NE_EXPR. */
4583 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
4586 lcode = TREE_CODE (lhs);
4587 rcode = TREE_CODE (rhs);
4589 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
4591 lhs = build2 (NE_EXPR, truth_type, lhs,
4592 fold_convert (TREE_TYPE (lhs), integer_zero_node));
4596 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
4598 rhs = build2 (NE_EXPR, truth_type, rhs,
4599 fold_convert (TREE_TYPE (rhs), integer_zero_node));
4603 if (TREE_CODE_CLASS (lcode) != tcc_comparison
4604 || TREE_CODE_CLASS (rcode) != tcc_comparison)
4607 ll_arg = TREE_OPERAND (lhs, 0);
4608 lr_arg = TREE_OPERAND (lhs, 1);
4609 rl_arg = TREE_OPERAND (rhs, 0);
4610 rr_arg = TREE_OPERAND (rhs, 1);
4612 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
4613 if (simple_operand_p (ll_arg)
4614 && simple_operand_p (lr_arg))
4617 if (operand_equal_p (ll_arg, rl_arg, 0)
4618 && operand_equal_p (lr_arg, rr_arg, 0))
4620 result = combine_comparisons (code, lcode, rcode,
4621 truth_type, ll_arg, lr_arg);
4625 else if (operand_equal_p (ll_arg, rr_arg, 0)
4626 && operand_equal_p (lr_arg, rl_arg, 0))
4628 result = combine_comparisons (code, lcode,
4629 swap_tree_comparison (rcode),
4630 truth_type, ll_arg, lr_arg);
4636 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
4637 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
4639 /* If the RHS can be evaluated unconditionally and its operands are
4640 simple, it wins to evaluate the RHS unconditionally on machines
4641 with expensive branches. In this case, this isn't a comparison
4642 that can be merged. Avoid doing this if the RHS is a floating-point
4643 comparison since those can trap. */
4645 if (BRANCH_COST >= 2
4646 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
4647 && simple_operand_p (rl_arg)
4648 && simple_operand_p (rr_arg))
4650 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
4651 if (code == TRUTH_OR_EXPR
4652 && lcode == NE_EXPR && integer_zerop (lr_arg)
4653 && rcode == NE_EXPR && integer_zerop (rr_arg)
4654 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
4655 return build2 (NE_EXPR, truth_type,
4656 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
4658 fold_convert (TREE_TYPE (ll_arg), integer_zero_node));
4660 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
4661 if (code == TRUTH_AND_EXPR
4662 && lcode == EQ_EXPR && integer_zerop (lr_arg)
4663 && rcode == EQ_EXPR && integer_zerop (rr_arg)
4664 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
4665 return build2 (EQ_EXPR, truth_type,
4666 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
4668 fold_convert (TREE_TYPE (ll_arg), integer_zero_node));
4670 if (LOGICAL_OP_NON_SHORT_CIRCUIT)
4671 return build2 (code, truth_type, lhs, rhs);
4674 /* See if the comparisons can be merged. Then get all the parameters for
4677 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
4678 || (rcode != EQ_EXPR && rcode != NE_EXPR))
4682 ll_inner = decode_field_reference (ll_arg,
4683 &ll_bitsize, &ll_bitpos, &ll_mode,
4684 &ll_unsignedp, &volatilep, &ll_mask,
4686 lr_inner = decode_field_reference (lr_arg,
4687 &lr_bitsize, &lr_bitpos, &lr_mode,
4688 &lr_unsignedp, &volatilep, &lr_mask,
4690 rl_inner = decode_field_reference (rl_arg,
4691 &rl_bitsize, &rl_bitpos, &rl_mode,
4692 &rl_unsignedp, &volatilep, &rl_mask,
4694 rr_inner = decode_field_reference (rr_arg,
4695 &rr_bitsize, &rr_bitpos, &rr_mode,
4696 &rr_unsignedp, &volatilep, &rr_mask,
4699 /* It must be true that the inner operation on the lhs of each
4700 comparison must be the same if we are to be able to do anything.
4701 Then see if we have constants. If not, the same must be true for
4703 if (volatilep || ll_inner == 0 || rl_inner == 0
4704 || ! operand_equal_p (ll_inner, rl_inner, 0))
4707 if (TREE_CODE (lr_arg) == INTEGER_CST
4708 && TREE_CODE (rr_arg) == INTEGER_CST)
4709 l_const = lr_arg, r_const = rr_arg;
4710 else if (lr_inner == 0 || rr_inner == 0
4711 || ! operand_equal_p (lr_inner, rr_inner, 0))
4714 l_const = r_const = 0;
4716 /* If either comparison code is not correct for our logical operation,
4717 fail. However, we can convert a one-bit comparison against zero into
4718 the opposite comparison against that bit being set in the field. */
4720 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
4721 if (lcode != wanted_code)
4723 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
4725 /* Make the left operand unsigned, since we are only interested
4726 in the value of one bit. Otherwise we are doing the wrong
4735 /* This is analogous to the code for l_const above. */
4736 if (rcode != wanted_code)
4738 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
4747 /* After this point all optimizations will generate bit-field
4748 references, which we might not want. */
4749 if (! lang_hooks.can_use_bit_fields_p ())
4752 /* See if we can find a mode that contains both fields being compared on
4753 the left. If we can't, fail. Otherwise, update all constants and masks
4754 to be relative to a field of that size. */
4755 first_bit = MIN (ll_bitpos, rl_bitpos);
4756 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
4757 lnmode = get_best_mode (end_bit - first_bit, first_bit,
4758 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
4760 if (lnmode == VOIDmode)
4763 lnbitsize = GET_MODE_BITSIZE (lnmode);
4764 lnbitpos = first_bit & ~ (lnbitsize - 1);
4765 lntype = lang_hooks.types.type_for_size (lnbitsize, 1);
4766 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
4768 if (BYTES_BIG_ENDIAN)
4770 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
4771 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
4774 ll_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, ll_mask),
4775 size_int (xll_bitpos), 0);
4776 rl_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, rl_mask),
4777 size_int (xrl_bitpos), 0);
4781 l_const = fold_convert (lntype, l_const);
4782 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
4783 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
4784 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
4785 fold (build1 (BIT_NOT_EXPR,
4789 warning ("comparison is always %d", wanted_code == NE_EXPR);
4791 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
4796 r_const = fold_convert (lntype, r_const);
4797 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
4798 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
4799 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
4800 fold (build1 (BIT_NOT_EXPR,
4804 warning ("comparison is always %d", wanted_code == NE_EXPR);
4806 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
4810 /* If the right sides are not constant, do the same for it. Also,
4811 disallow this optimization if a size or signedness mismatch occurs
4812 between the left and right sides. */
4815 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
4816 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
4817 /* Make sure the two fields on the right
4818 correspond to the left without being swapped. */
4819 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
4822 first_bit = MIN (lr_bitpos, rr_bitpos);
4823 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
4824 rnmode = get_best_mode (end_bit - first_bit, first_bit,
4825 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
4827 if (rnmode == VOIDmode)
4830 rnbitsize = GET_MODE_BITSIZE (rnmode);
4831 rnbitpos = first_bit & ~ (rnbitsize - 1);
4832 rntype = lang_hooks.types.type_for_size (rnbitsize, 1);
4833 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
4835 if (BYTES_BIG_ENDIAN)
4837 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
4838 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
4841 lr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, lr_mask),
4842 size_int (xlr_bitpos), 0);
4843 rr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, rr_mask),
4844 size_int (xrr_bitpos), 0);
4846 /* Make a mask that corresponds to both fields being compared.
4847 Do this for both items being compared. If the operands are the
4848 same size and the bits being compared are in the same position
4849 then we can do this by masking both and comparing the masked
4851 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4852 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
4853 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
4855 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4856 ll_unsignedp || rl_unsignedp);
4857 if (! all_ones_mask_p (ll_mask, lnbitsize))
4858 lhs = build2 (BIT_AND_EXPR, lntype, lhs, ll_mask);
4860 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
4861 lr_unsignedp || rr_unsignedp);
4862 if (! all_ones_mask_p (lr_mask, rnbitsize))
4863 rhs = build2 (BIT_AND_EXPR, rntype, rhs, lr_mask);
4865 return build2 (wanted_code, truth_type, lhs, rhs);
4868 /* There is still another way we can do something: If both pairs of
4869 fields being compared are adjacent, we may be able to make a wider
4870 field containing them both.
4872 Note that we still must mask the lhs/rhs expressions. Furthermore,
4873 the mask must be shifted to account for the shift done by
4874 make_bit_field_ref. */
4875 if ((ll_bitsize + ll_bitpos == rl_bitpos
4876 && lr_bitsize + lr_bitpos == rr_bitpos)
4877 || (ll_bitpos == rl_bitpos + rl_bitsize
4878 && lr_bitpos == rr_bitpos + rr_bitsize))
4882 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
4883 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
4884 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
4885 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
4887 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
4888 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
4889 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
4890 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
4892 /* Convert to the smaller type before masking out unwanted bits. */
4894 if (lntype != rntype)
4896 if (lnbitsize > rnbitsize)
4898 lhs = fold_convert (rntype, lhs);
4899 ll_mask = fold_convert (rntype, ll_mask);
4902 else if (lnbitsize < rnbitsize)
4904 rhs = fold_convert (lntype, rhs);
4905 lr_mask = fold_convert (lntype, lr_mask);
4910 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
4911 lhs = build2 (BIT_AND_EXPR, type, lhs, ll_mask);
4913 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
4914 rhs = build2 (BIT_AND_EXPR, type, rhs, lr_mask);
4916 return build2 (wanted_code, truth_type, lhs, rhs);
4922 /* Handle the case of comparisons with constants. If there is something in
4923 common between the masks, those bits of the constants must be the same.
4924 If not, the condition is always false. Test for this to avoid generating
4925 incorrect code below. */
4926 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
4927 if (! integer_zerop (result)
4928 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
4929 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
4931 if (wanted_code == NE_EXPR)
4933 warning ("%<or%> of unmatched not-equal tests is always 1");
4934 return constant_boolean_node (true, truth_type);
4938 warning ("%<and%> of mutually exclusive equal-tests is always 0");
4939 return constant_boolean_node (false, truth_type);
4943 /* Construct the expression we will return. First get the component
4944 reference we will make. Unless the mask is all ones the width of
4945 that field, perform the mask operation. Then compare with the
4947 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4948 ll_unsignedp || rl_unsignedp);
4950 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4951 if (! all_ones_mask_p (ll_mask, lnbitsize))
4952 result = build2 (BIT_AND_EXPR, lntype, result, ll_mask);
4954 return build2 (wanted_code, truth_type, result,
4955 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
4958 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
4962 optimize_minmax_comparison (tree t)
4964 tree type = TREE_TYPE (t);
4965 tree arg0 = TREE_OPERAND (t, 0);
4966 enum tree_code op_code;
4967 tree comp_const = TREE_OPERAND (t, 1);
4969 int consts_equal, consts_lt;
4972 STRIP_SIGN_NOPS (arg0);
4974 op_code = TREE_CODE (arg0);
4975 minmax_const = TREE_OPERAND (arg0, 1);
4976 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
4977 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
4978 inner = TREE_OPERAND (arg0, 0);
4980 /* If something does not permit us to optimize, return the original tree. */
4981 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
4982 || TREE_CODE (comp_const) != INTEGER_CST
4983 || TREE_CONSTANT_OVERFLOW (comp_const)
4984 || TREE_CODE (minmax_const) != INTEGER_CST
4985 || TREE_CONSTANT_OVERFLOW (minmax_const))
4988 /* Now handle all the various comparison codes. We only handle EQ_EXPR
4989 and GT_EXPR, doing the rest with recursive calls using logical
4991 switch (TREE_CODE (t))
4993 case NE_EXPR: case LT_EXPR: case LE_EXPR:
4995 invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t)));
4999 fold (build2 (TRUTH_ORIF_EXPR, type,
5000 optimize_minmax_comparison
5001 (build2 (EQ_EXPR, type, arg0, comp_const)),
5002 optimize_minmax_comparison
5003 (build2 (GT_EXPR, type, arg0, comp_const))));
5006 if (op_code == MAX_EXPR && consts_equal)
5007 /* MAX (X, 0) == 0 -> X <= 0 */
5008 return fold (build2 (LE_EXPR, type, inner, comp_const));
5010 else if (op_code == MAX_EXPR && consts_lt)
5011 /* MAX (X, 0) == 5 -> X == 5 */
5012 return fold (build2 (EQ_EXPR, type, inner, comp_const));
5014 else if (op_code == MAX_EXPR)
5015 /* MAX (X, 0) == -1 -> false */
5016 return omit_one_operand (type, integer_zero_node, inner);
5018 else if (consts_equal)
5019 /* MIN (X, 0) == 0 -> X >= 0 */
5020 return fold (build2 (GE_EXPR, type, inner, comp_const));
5023 /* MIN (X, 0) == 5 -> false */
5024 return omit_one_operand (type, integer_zero_node, inner);
5027 /* MIN (X, 0) == -1 -> X == -1 */
5028 return fold (build2 (EQ_EXPR, type, inner, comp_const));
5031 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
5032 /* MAX (X, 0) > 0 -> X > 0
5033 MAX (X, 0) > 5 -> X > 5 */
5034 return fold (build2 (GT_EXPR, type, inner, comp_const));
5036 else if (op_code == MAX_EXPR)
5037 /* MAX (X, 0) > -1 -> true */
5038 return omit_one_operand (type, integer_one_node, inner);
5040 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
5041 /* MIN (X, 0) > 0 -> false
5042 MIN (X, 0) > 5 -> false */
5043 return omit_one_operand (type, integer_zero_node, inner);
5046 /* MIN (X, 0) > -1 -> X > -1 */
5047 return fold (build2 (GT_EXPR, type, inner, comp_const));
5054 /* T is an integer expression that is being multiplied, divided, or taken a
5055 modulus (CODE says which and what kind of divide or modulus) by a
5056 constant C. See if we can eliminate that operation by folding it with
5057 other operations already in T. WIDE_TYPE, if non-null, is a type that
5058 should be used for the computation if wider than our type.
5060 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
5061 (X * 2) + (Y * 4). We must, however, be assured that either the original
5062 expression would not overflow or that overflow is undefined for the type
5063 in the language in question.
5065 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
5066 the machine has a multiply-accumulate insn or that this is part of an
5067 addressing calculation.
5069 If we return a non-null expression, it is an equivalent form of the
5070 original computation, but need not be in the original type. */
5073 extract_muldiv (tree t, tree c, enum tree_code code, tree wide_type)
5075 /* To avoid exponential search depth, refuse to allow recursion past
5076 three levels. Beyond that (1) it's highly unlikely that we'll find
5077 something interesting and (2) we've probably processed it before
5078 when we built the inner expression. */
5087 ret = extract_muldiv_1 (t, c, code, wide_type);
5094 extract_muldiv_1 (tree t, tree c, enum tree_code code, tree wide_type)
5096 tree type = TREE_TYPE (t);
5097 enum tree_code tcode = TREE_CODE (t);
5098 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
5099 > GET_MODE_SIZE (TYPE_MODE (type)))
5100 ? wide_type : type);
5102 int same_p = tcode == code;
5103 tree op0 = NULL_TREE, op1 = NULL_TREE;
5105 /* Don't deal with constants of zero here; they confuse the code below. */
5106 if (integer_zerop (c))
5109 if (TREE_CODE_CLASS (tcode) == tcc_unary)
5110 op0 = TREE_OPERAND (t, 0);
5112 if (TREE_CODE_CLASS (tcode) == tcc_binary)
5113 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
5115 /* Note that we need not handle conditional operations here since fold
5116 already handles those cases. So just do arithmetic here. */
5120 /* For a constant, we can always simplify if we are a multiply
5121 or (for divide and modulus) if it is a multiple of our constant. */
5122 if (code == MULT_EXPR
5123 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
5124 return const_binop (code, fold_convert (ctype, t),
5125 fold_convert (ctype, c), 0);
5128 case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
5129 /* If op0 is an expression ... */
5130 if ((COMPARISON_CLASS_P (op0)
5131 || UNARY_CLASS_P (op0)
5132 || BINARY_CLASS_P (op0)
5133 || EXPRESSION_CLASS_P (op0))
5134 /* ... and is unsigned, and its type is smaller than ctype,
5135 then we cannot pass through as widening. */
5136 && ((TYPE_UNSIGNED (TREE_TYPE (op0))
5137 && ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
5138 && TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
5139 && (GET_MODE_SIZE (TYPE_MODE (ctype))
5140 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
5141 /* ... or this is a truncation (t is narrower than op0),
5142 then we cannot pass through this narrowing. */
5143 || (GET_MODE_SIZE (TYPE_MODE (type))
5144 < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0))))
5145 /* ... or signedness changes for division or modulus,
5146 then we cannot pass through this conversion. */
5147 || (code != MULT_EXPR
5148 && (TYPE_UNSIGNED (ctype)
5149 != TYPE_UNSIGNED (TREE_TYPE (op0))))))
5152 /* Pass the constant down and see if we can make a simplification. If
5153 we can, replace this expression with the inner simplification for
5154 possible later conversion to our or some other type. */
5155 if ((t2 = fold_convert (TREE_TYPE (op0), c)) != 0
5156 && TREE_CODE (t2) == INTEGER_CST
5157 && ! TREE_CONSTANT_OVERFLOW (t2)
5158 && (0 != (t1 = extract_muldiv (op0, t2, code,
5160 ? ctype : NULL_TREE))))
5165 /* If widening the type changes it from signed to unsigned, then we
5166 must avoid building ABS_EXPR itself as unsigned. */
5167 if (TYPE_UNSIGNED (ctype) && !TYPE_UNSIGNED (type))
5169 tree cstype = (*lang_hooks.types.signed_type) (ctype);
5170 if ((t1 = extract_muldiv (op0, c, code, cstype)) != 0)
5172 t1 = fold (build1 (tcode, cstype, fold_convert (cstype, t1)));
5173 return fold_convert (ctype, t1);
5179 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
5180 return fold (build1 (tcode, ctype, fold_convert (ctype, t1)));
5183 case MIN_EXPR: case MAX_EXPR:
5184 /* If widening the type changes the signedness, then we can't perform
5185 this optimization as that changes the result. */
5186 if (TYPE_UNSIGNED (ctype) != TYPE_UNSIGNED (type))
5189 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
5190 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0
5191 && (t2 = extract_muldiv (op1, c, code, wide_type)) != 0)
5193 if (tree_int_cst_sgn (c) < 0)
5194 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
5196 return fold (build2 (tcode, ctype, fold_convert (ctype, t1),
5197 fold_convert (ctype, t2)));
5201 case LSHIFT_EXPR: case RSHIFT_EXPR:
5202 /* If the second operand is constant, this is a multiplication
5203 or floor division, by a power of two, so we can treat it that
5204 way unless the multiplier or divisor overflows. Signed
5205 left-shift overflow is implementation-defined rather than
5206 undefined in C90, so do not convert signed left shift into
5208 if (TREE_CODE (op1) == INTEGER_CST
5209 && (tcode == RSHIFT_EXPR || TYPE_UNSIGNED (TREE_TYPE (op0)))
5210 /* const_binop may not detect overflow correctly,
5211 so check for it explicitly here. */
5212 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
5213 && TREE_INT_CST_HIGH (op1) == 0
5214 && 0 != (t1 = fold_convert (ctype,
5215 const_binop (LSHIFT_EXPR,
5218 && ! TREE_OVERFLOW (t1))
5219 return extract_muldiv (build2 (tcode == LSHIFT_EXPR
5220 ? MULT_EXPR : FLOOR_DIV_EXPR,
5221 ctype, fold_convert (ctype, op0), t1),
5222 c, code, wide_type);
5225 case PLUS_EXPR: case MINUS_EXPR:
5226 /* See if we can eliminate the operation on both sides. If we can, we
5227 can return a new PLUS or MINUS. If we can't, the only remaining
5228 cases where we can do anything are if the second operand is a
5230 t1 = extract_muldiv (op0, c, code, wide_type);
5231 t2 = extract_muldiv (op1, c, code, wide_type);
5232 if (t1 != 0 && t2 != 0
5233 && (code == MULT_EXPR
5234 /* If not multiplication, we can only do this if both operands
5235 are divisible by c. */
5236 || (multiple_of_p (ctype, op0, c)
5237 && multiple_of_p (ctype, op1, c))))
5238 return fold (build2 (tcode, ctype, fold_convert (ctype, t1),
5239 fold_convert (ctype, t2)));
5241 /* If this was a subtraction, negate OP1 and set it to be an addition.
5242 This simplifies the logic below. */
5243 if (tcode == MINUS_EXPR)
5244 tcode = PLUS_EXPR, op1 = negate_expr (op1);
5246 if (TREE_CODE (op1) != INTEGER_CST)
5249 /* If either OP1 or C are negative, this optimization is not safe for
5250 some of the division and remainder types while for others we need
5251 to change the code. */
5252 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
5254 if (code == CEIL_DIV_EXPR)
5255 code = FLOOR_DIV_EXPR;
5256 else if (code == FLOOR_DIV_EXPR)
5257 code = CEIL_DIV_EXPR;
5258 else if (code != MULT_EXPR
5259 && code != CEIL_MOD_EXPR && code != FLOOR_MOD_EXPR)
5263 /* If it's a multiply or a division/modulus operation of a multiple
5264 of our constant, do the operation and verify it doesn't overflow. */
5265 if (code == MULT_EXPR
5266 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5268 op1 = const_binop (code, fold_convert (ctype, op1),
5269 fold_convert (ctype, c), 0);
5270 /* We allow the constant to overflow with wrapping semantics. */
5272 || (TREE_OVERFLOW (op1) && ! flag_wrapv))
5278 /* If we have an unsigned type is not a sizetype, we cannot widen
5279 the operation since it will change the result if the original
5280 computation overflowed. */
5281 if (TYPE_UNSIGNED (ctype)
5282 && ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
5286 /* If we were able to eliminate our operation from the first side,
5287 apply our operation to the second side and reform the PLUS. */
5288 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
5289 return fold (build2 (tcode, ctype, fold_convert (ctype, t1), op1));
5291 /* The last case is if we are a multiply. In that case, we can
5292 apply the distributive law to commute the multiply and addition
5293 if the multiplication of the constants doesn't overflow. */
5294 if (code == MULT_EXPR)
5295 return fold (build2 (tcode, ctype,
5296 fold (build2 (code, ctype,
5297 fold_convert (ctype, op0),
5298 fold_convert (ctype, c))),
5304 /* We have a special case here if we are doing something like
5305 (C * 8) % 4 since we know that's zero. */
5306 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
5307 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
5308 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
5309 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5310 return omit_one_operand (type, integer_zero_node, op0);
5312 /* ... fall through ... */
5314 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
5315 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
5316 /* If we can extract our operation from the LHS, do so and return a
5317 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
5318 do something only if the second operand is a constant. */
5320 && (t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
5321 return fold (build2 (tcode, ctype, fold_convert (ctype, t1),
5322 fold_convert (ctype, op1)));
5323 else if (tcode == MULT_EXPR && code == MULT_EXPR
5324 && (t1 = extract_muldiv (op1, c, code, wide_type)) != 0)
5325 return fold (build2 (tcode, ctype, fold_convert (ctype, op0),
5326 fold_convert (ctype, t1)));
5327 else if (TREE_CODE (op1) != INTEGER_CST)
5330 /* If these are the same operation types, we can associate them
5331 assuming no overflow. */
5333 && 0 != (t1 = const_binop (MULT_EXPR, fold_convert (ctype, op1),
5334 fold_convert (ctype, c), 0))
5335 && ! TREE_OVERFLOW (t1))
5336 return fold (build2 (tcode, ctype, fold_convert (ctype, op0), t1));
5338 /* If these operations "cancel" each other, we have the main
5339 optimizations of this pass, which occur when either constant is a
5340 multiple of the other, in which case we replace this with either an
5341 operation or CODE or TCODE.
5343 If we have an unsigned type that is not a sizetype, we cannot do
5344 this since it will change the result if the original computation
5346 if ((! TYPE_UNSIGNED (ctype)
5347 || (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
5349 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
5350 || (tcode == MULT_EXPR
5351 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
5352 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR)))
5354 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5355 return fold (build2 (tcode, ctype, fold_convert (ctype, op0),
5356 fold_convert (ctype,
5357 const_binop (TRUNC_DIV_EXPR,
5359 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
5360 return fold (build2 (code, ctype, fold_convert (ctype, op0),
5361 fold_convert (ctype,
5362 const_binop (TRUNC_DIV_EXPR,
5374 /* Return a node which has the indicated constant VALUE (either 0 or
5375 1), and is of the indicated TYPE. */
5378 constant_boolean_node (int value, tree type)
5380 if (type == integer_type_node)
5381 return value ? integer_one_node : integer_zero_node;
5382 else if (type == boolean_type_node)
5383 return value ? boolean_true_node : boolean_false_node;
5385 return build_int_cst (type, value);
5389 /* Return true if expr looks like an ARRAY_REF and set base and
5390 offset to the appropriate trees. If there is no offset,
5391 offset is set to NULL_TREE. */
5394 extract_array_ref (tree expr, tree *base, tree *offset)
5396 /* We have to be careful with stripping nops as with the
5397 base type the meaning of the offset can change. */
5398 tree inner_expr = expr;
5399 STRIP_NOPS (inner_expr);
5400 /* One canonical form is a PLUS_EXPR with the first
5401 argument being an ADDR_EXPR with a possible NOP_EXPR
5403 if (TREE_CODE (expr) == PLUS_EXPR)
5405 tree op0 = TREE_OPERAND (expr, 0);
5407 if (TREE_CODE (op0) == ADDR_EXPR)
5409 *base = TREE_OPERAND (expr, 0);
5410 *offset = TREE_OPERAND (expr, 1);
5414 /* Other canonical form is an ADDR_EXPR of an ARRAY_REF,
5415 which we transform into an ADDR_EXPR with appropriate
5416 offset. For other arguments to the ADDR_EXPR we assume
5417 zero offset and as such do not care about the ADDR_EXPR
5418 type and strip possible nops from it. */
5419 else if (TREE_CODE (inner_expr) == ADDR_EXPR)
5421 tree op0 = TREE_OPERAND (inner_expr, 0);
5422 if (TREE_CODE (op0) == ARRAY_REF)
5424 *base = build_fold_addr_expr (TREE_OPERAND (op0, 0));
5425 *offset = TREE_OPERAND (op0, 1);
5430 *offset = NULL_TREE;
5439 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
5440 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
5441 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
5442 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
5443 COND is the first argument to CODE; otherwise (as in the example
5444 given here), it is the second argument. TYPE is the type of the
5445 original expression. Return NULL_TREE if no simplification is
5449 fold_binary_op_with_conditional_arg (tree t, enum tree_code code, tree cond,
5450 tree arg, int cond_first_p)
5452 const tree type = TREE_TYPE (t);
5453 tree cond_type = cond_first_p ? TREE_TYPE (TREE_OPERAND (t, 0))
5454 : TREE_TYPE (TREE_OPERAND (t, 1));
5455 tree arg_type = cond_first_p ? TREE_TYPE (TREE_OPERAND (t, 1))
5456 : TREE_TYPE (TREE_OPERAND (t, 0));
5457 tree test, true_value, false_value;
5458 tree lhs = NULL_TREE;
5459 tree rhs = NULL_TREE;
5461 /* This transformation is only worthwhile if we don't have to wrap
5462 arg in a SAVE_EXPR, and the operation can be simplified on at least
5463 one of the branches once its pushed inside the COND_EXPR. */
5464 if (!TREE_CONSTANT (arg))
5467 if (TREE_CODE (cond) == COND_EXPR)
5469 test = TREE_OPERAND (cond, 0);
5470 true_value = TREE_OPERAND (cond, 1);
5471 false_value = TREE_OPERAND (cond, 2);
5472 /* If this operand throws an expression, then it does not make
5473 sense to try to perform a logical or arithmetic operation
5475 if (VOID_TYPE_P (TREE_TYPE (true_value)))
5477 if (VOID_TYPE_P (TREE_TYPE (false_value)))
5482 tree testtype = TREE_TYPE (cond);
5484 true_value = constant_boolean_node (true, testtype);
5485 false_value = constant_boolean_node (false, testtype);
5488 arg = fold_convert (arg_type, arg);
5491 true_value = fold_convert (cond_type, true_value);
5492 lhs = fold (cond_first_p ? build2 (code, type, true_value, arg)
5493 : build2 (code, type, arg, true_value));
5497 false_value = fold_convert (cond_type, false_value);
5498 rhs = fold (cond_first_p ? build2 (code, type, false_value, arg)
5499 : build2 (code, type, arg, false_value));
5502 test = fold (build3 (COND_EXPR, type, test, lhs, rhs));
5503 return fold_convert (type, test);
5507 /* Subroutine of fold() that checks for the addition of +/- 0.0.
5509 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
5510 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
5511 ADDEND is the same as X.
5513 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
5514 and finite. The problematic cases are when X is zero, and its mode
5515 has signed zeros. In the case of rounding towards -infinity,
5516 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
5517 modes, X + 0 is not the same as X because -0 + 0 is 0. */
5520 fold_real_zero_addition_p (tree type, tree addend, int negate)
5522 if (!real_zerop (addend))
5525 /* Don't allow the fold with -fsignaling-nans. */
5526 if (HONOR_SNANS (TYPE_MODE (type)))
5529 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
5530 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
5533 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
5534 if (TREE_CODE (addend) == REAL_CST
5535 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
5538 /* The mode has signed zeros, and we have to honor their sign.
5539 In this situation, there is only one case we can return true for.
5540 X - 0 is the same as X unless rounding towards -infinity is
5542 return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
5545 /* Subroutine of fold() that checks comparisons of built-in math
5546 functions against real constants.
5548 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
5549 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
5550 is the type of the result and ARG0 and ARG1 are the operands of the
5551 comparison. ARG1 must be a TREE_REAL_CST.
5553 The function returns the constant folded tree if a simplification
5554 can be made, and NULL_TREE otherwise. */
5557 fold_mathfn_compare (enum built_in_function fcode, enum tree_code code,
5558 tree type, tree arg0, tree arg1)
5562 if (BUILTIN_SQRT_P (fcode))
5564 tree arg = TREE_VALUE (TREE_OPERAND (arg0, 1));
5565 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg0));
5567 c = TREE_REAL_CST (arg1);
5568 if (REAL_VALUE_NEGATIVE (c))
5570 /* sqrt(x) < y is always false, if y is negative. */
5571 if (code == EQ_EXPR || code == LT_EXPR || code == LE_EXPR)
5572 return omit_one_operand (type, integer_zero_node, arg);
5574 /* sqrt(x) > y is always true, if y is negative and we
5575 don't care about NaNs, i.e. negative values of x. */
5576 if (code == NE_EXPR || !HONOR_NANS (mode))
5577 return omit_one_operand (type, integer_one_node, arg);
5579 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
5580 return fold (build2 (GE_EXPR, type, arg,
5581 build_real (TREE_TYPE (arg), dconst0)));
5583 else if (code == GT_EXPR || code == GE_EXPR)
5587 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
5588 real_convert (&c2, mode, &c2);
5590 if (REAL_VALUE_ISINF (c2))
5592 /* sqrt(x) > y is x == +Inf, when y is very large. */
5593 if (HONOR_INFINITIES (mode))
5594 return fold (build2 (EQ_EXPR, type, arg,
5595 build_real (TREE_TYPE (arg), c2)));
5597 /* sqrt(x) > y is always false, when y is very large
5598 and we don't care about infinities. */
5599 return omit_one_operand (type, integer_zero_node, arg);
5602 /* sqrt(x) > c is the same as x > c*c. */
5603 return fold (build2 (code, type, arg,
5604 build_real (TREE_TYPE (arg), c2)));
5606 else if (code == LT_EXPR || code == LE_EXPR)
5610 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
5611 real_convert (&c2, mode, &c2);
5613 if (REAL_VALUE_ISINF (c2))
5615 /* sqrt(x) < y is always true, when y is a very large
5616 value and we don't care about NaNs or Infinities. */
5617 if (! HONOR_NANS (mode) && ! HONOR_INFINITIES (mode))
5618 return omit_one_operand (type, integer_one_node, arg);
5620 /* sqrt(x) < y is x != +Inf when y is very large and we
5621 don't care about NaNs. */
5622 if (! HONOR_NANS (mode))
5623 return fold (build2 (NE_EXPR, type, arg,
5624 build_real (TREE_TYPE (arg), c2)));
5626 /* sqrt(x) < y is x >= 0 when y is very large and we
5627 don't care about Infinities. */
5628 if (! HONOR_INFINITIES (mode))
5629 return fold (build2 (GE_EXPR, type, arg,
5630 build_real (TREE_TYPE (arg), dconst0)));
5632 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
5633 if (lang_hooks.decls.global_bindings_p () != 0
5634 || CONTAINS_PLACEHOLDER_P (arg))
5637 arg = save_expr (arg);
5638 return fold (build2 (TRUTH_ANDIF_EXPR, type,
5639 fold (build2 (GE_EXPR, type, arg,
5640 build_real (TREE_TYPE (arg),
5642 fold (build2 (NE_EXPR, type, arg,
5643 build_real (TREE_TYPE (arg),
5647 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
5648 if (! HONOR_NANS (mode))
5649 return fold (build2 (code, type, arg,
5650 build_real (TREE_TYPE (arg), c2)));
5652 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
5653 if (lang_hooks.decls.global_bindings_p () == 0
5654 && ! CONTAINS_PLACEHOLDER_P (arg))
5656 arg = save_expr (arg);
5657 return fold (build2 (TRUTH_ANDIF_EXPR, type,
5658 fold (build2 (GE_EXPR, type, arg,
5659 build_real (TREE_TYPE (arg),
5661 fold (build2 (code, type, arg,
5662 build_real (TREE_TYPE (arg),
5671 /* Subroutine of fold() that optimizes comparisons against Infinities,
5672 either +Inf or -Inf.
5674 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
5675 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
5676 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
5678 The function returns the constant folded tree if a simplification
5679 can be made, and NULL_TREE otherwise. */
5682 fold_inf_compare (enum tree_code code, tree type, tree arg0, tree arg1)
5684 enum machine_mode mode;
5685 REAL_VALUE_TYPE max;
5689 mode = TYPE_MODE (TREE_TYPE (arg0));
5691 /* For negative infinity swap the sense of the comparison. */
5692 neg = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1));
5694 code = swap_tree_comparison (code);
5699 /* x > +Inf is always false, if with ignore sNANs. */
5700 if (HONOR_SNANS (mode))
5702 return omit_one_operand (type, integer_zero_node, arg0);
5705 /* x <= +Inf is always true, if we don't case about NaNs. */
5706 if (! HONOR_NANS (mode))
5707 return omit_one_operand (type, integer_one_node, arg0);
5709 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
5710 if (lang_hooks.decls.global_bindings_p () == 0
5711 && ! CONTAINS_PLACEHOLDER_P (arg0))
5713 arg0 = save_expr (arg0);
5714 return fold (build2 (EQ_EXPR, type, arg0, arg0));
5720 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
5721 real_maxval (&max, neg, mode);
5722 return fold (build2 (neg ? LT_EXPR : GT_EXPR, type,
5723 arg0, build_real (TREE_TYPE (arg0), max)));
5726 /* x < +Inf is always equal to x <= DBL_MAX. */
5727 real_maxval (&max, neg, mode);
5728 return fold (build2 (neg ? GE_EXPR : LE_EXPR, type,
5729 arg0, build_real (TREE_TYPE (arg0), max)));
5732 /* x != +Inf is always equal to !(x > DBL_MAX). */
5733 real_maxval (&max, neg, mode);
5734 if (! HONOR_NANS (mode))
5735 return fold (build2 (neg ? GE_EXPR : LE_EXPR, type,
5736 arg0, build_real (TREE_TYPE (arg0), max)));
5738 /* The transformation below creates non-gimple code and thus is
5739 not appropriate if we are in gimple form. */
5743 temp = fold (build2 (neg ? LT_EXPR : GT_EXPR, type,
5744 arg0, build_real (TREE_TYPE (arg0), max)));
5745 return fold (build1 (TRUTH_NOT_EXPR, type, temp));
5754 /* Subroutine of fold() that optimizes comparisons of a division by
5755 a nonzero integer constant against an integer constant, i.e.
5758 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
5759 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
5760 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
5762 The function returns the constant folded tree if a simplification
5763 can be made, and NULL_TREE otherwise. */
5766 fold_div_compare (enum tree_code code, tree type, tree arg0, tree arg1)
5768 tree prod, tmp, hi, lo;
5769 tree arg00 = TREE_OPERAND (arg0, 0);
5770 tree arg01 = TREE_OPERAND (arg0, 1);
5771 unsigned HOST_WIDE_INT lpart;
5772 HOST_WIDE_INT hpart;
5775 /* We have to do this the hard way to detect unsigned overflow.
5776 prod = int_const_binop (MULT_EXPR, arg01, arg1, 0); */
5777 overflow = mul_double (TREE_INT_CST_LOW (arg01),
5778 TREE_INT_CST_HIGH (arg01),
5779 TREE_INT_CST_LOW (arg1),
5780 TREE_INT_CST_HIGH (arg1), &lpart, &hpart);
5781 prod = build_int_cst_wide (TREE_TYPE (arg00), lpart, hpart);
5782 prod = force_fit_type (prod, -1, overflow, false);
5784 if (TYPE_UNSIGNED (TREE_TYPE (arg0)))
5786 tmp = int_const_binop (MINUS_EXPR, arg01, integer_one_node, 0);
5789 /* Likewise hi = int_const_binop (PLUS_EXPR, prod, tmp, 0). */
5790 overflow = add_double (TREE_INT_CST_LOW (prod),
5791 TREE_INT_CST_HIGH (prod),
5792 TREE_INT_CST_LOW (tmp),
5793 TREE_INT_CST_HIGH (tmp),
5795 hi = build_int_cst_wide (TREE_TYPE (arg00), lpart, hpart);
5796 hi = force_fit_type (hi, -1, overflow | TREE_OVERFLOW (prod),
5797 TREE_CONSTANT_OVERFLOW (prod));
5799 else if (tree_int_cst_sgn (arg01) >= 0)
5801 tmp = int_const_binop (MINUS_EXPR, arg01, integer_one_node, 0);
5802 switch (tree_int_cst_sgn (arg1))
5805 lo = int_const_binop (MINUS_EXPR, prod, tmp, 0);
5810 lo = fold_negate_const (tmp, TREE_TYPE (arg0));
5815 hi = int_const_binop (PLUS_EXPR, prod, tmp, 0);
5825 /* A negative divisor reverses the relational operators. */
5826 code = swap_tree_comparison (code);
5828 tmp = int_const_binop (PLUS_EXPR, arg01, integer_one_node, 0);
5829 switch (tree_int_cst_sgn (arg1))
5832 hi = int_const_binop (MINUS_EXPR, prod, tmp, 0);
5837 hi = fold_negate_const (tmp, TREE_TYPE (arg0));
5842 lo = int_const_binop (PLUS_EXPR, prod, tmp, 0);
5854 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
5855 return omit_one_operand (type, integer_zero_node, arg00);
5856 if (TREE_OVERFLOW (hi))
5857 return fold (build2 (GE_EXPR, type, arg00, lo));
5858 if (TREE_OVERFLOW (lo))
5859 return fold (build2 (LE_EXPR, type, arg00, hi));
5860 return build_range_check (type, arg00, 1, lo, hi);
5863 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
5864 return omit_one_operand (type, integer_one_node, arg00);
5865 if (TREE_OVERFLOW (hi))
5866 return fold (build2 (LT_EXPR, type, arg00, lo));
5867 if (TREE_OVERFLOW (lo))
5868 return fold (build2 (GT_EXPR, type, arg00, hi));
5869 return build_range_check (type, arg00, 0, lo, hi);
5872 if (TREE_OVERFLOW (lo))
5873 return omit_one_operand (type, integer_zero_node, arg00);
5874 return fold (build2 (LT_EXPR, type, arg00, lo));
5877 if (TREE_OVERFLOW (hi))
5878 return omit_one_operand (type, integer_one_node, arg00);
5879 return fold (build2 (LE_EXPR, type, arg00, hi));
5882 if (TREE_OVERFLOW (hi))
5883 return omit_one_operand (type, integer_zero_node, arg00);
5884 return fold (build2 (GT_EXPR, type, arg00, hi));
5887 if (TREE_OVERFLOW (lo))
5888 return omit_one_operand (type, integer_one_node, arg00);
5889 return fold (build2 (GE_EXPR, type, arg00, lo));
5899 /* If CODE with arguments ARG0 and ARG1 represents a single bit
5900 equality/inequality test, then return a simplified form of
5901 the test using shifts and logical operations. Otherwise return
5902 NULL. TYPE is the desired result type. */
5905 fold_single_bit_test (enum tree_code code, tree arg0, tree arg1,
5908 /* If this is testing a single bit, we can optimize the test. */
5909 if ((code == NE_EXPR || code == EQ_EXPR)
5910 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
5911 && integer_pow2p (TREE_OPERAND (arg0, 1)))
5913 tree inner = TREE_OPERAND (arg0, 0);
5914 tree type = TREE_TYPE (arg0);
5915 int bitnum = tree_log2 (TREE_OPERAND (arg0, 1));
5916 enum machine_mode operand_mode = TYPE_MODE (type);
5918 tree signed_type, unsigned_type, intermediate_type;
5921 /* If we have (A & C) != 0 where C is the sign bit of A, convert
5922 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
5923 arg00 = sign_bit_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
5924 if (arg00 != NULL_TREE
5925 /* This is only a win if casting to a signed type is cheap,
5926 i.e. when arg00's type is not a partial mode. */
5927 && TYPE_PRECISION (TREE_TYPE (arg00))
5928 == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg00))))
5930 tree stype = lang_hooks.types.signed_type (TREE_TYPE (arg00));
5931 return fold (build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
5932 result_type, fold_convert (stype, arg00),
5933 fold_convert (stype, integer_zero_node)));
5936 /* Otherwise we have (A & C) != 0 where C is a single bit,
5937 convert that into ((A >> C2) & 1). Where C2 = log2(C).
5938 Similarly for (A & C) == 0. */
5940 /* If INNER is a right shift of a constant and it plus BITNUM does
5941 not overflow, adjust BITNUM and INNER. */
5942 if (TREE_CODE (inner) == RSHIFT_EXPR
5943 && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST
5944 && TREE_INT_CST_HIGH (TREE_OPERAND (inner, 1)) == 0
5945 && bitnum < TYPE_PRECISION (type)
5946 && 0 > compare_tree_int (TREE_OPERAND (inner, 1),
5947 bitnum - TYPE_PRECISION (type)))
5949 bitnum += TREE_INT_CST_LOW (TREE_OPERAND (inner, 1));
5950 inner = TREE_OPERAND (inner, 0);
5953 /* If we are going to be able to omit the AND below, we must do our
5954 operations as unsigned. If we must use the AND, we have a choice.
5955 Normally unsigned is faster, but for some machines signed is. */
5956 #ifdef LOAD_EXTEND_OP
5957 ops_unsigned = (LOAD_EXTEND_OP (operand_mode) == SIGN_EXTEND
5958 && !flag_syntax_only) ? 0 : 1;
5963 signed_type = lang_hooks.types.type_for_mode (operand_mode, 0);
5964 unsigned_type = lang_hooks.types.type_for_mode (operand_mode, 1);
5965 intermediate_type = ops_unsigned ? unsigned_type : signed_type;
5966 inner = fold_convert (intermediate_type, inner);
5969 inner = build2 (RSHIFT_EXPR, intermediate_type,
5970 inner, size_int (bitnum));
5972 if (code == EQ_EXPR)
5973 inner = fold (build2 (BIT_XOR_EXPR, intermediate_type,
5974 inner, integer_one_node));
5976 /* Put the AND last so it can combine with more things. */
5977 inner = build2 (BIT_AND_EXPR, intermediate_type,
5978 inner, integer_one_node);
5980 /* Make sure to return the proper type. */
5981 inner = fold_convert (result_type, inner);
5988 /* Check whether we are allowed to reorder operands arg0 and arg1,
5989 such that the evaluation of arg1 occurs before arg0. */
5992 reorder_operands_p (tree arg0, tree arg1)
5994 if (! flag_evaluation_order)
5996 if (TREE_CONSTANT (arg0) || TREE_CONSTANT (arg1))
5998 return ! TREE_SIDE_EFFECTS (arg0)
5999 && ! TREE_SIDE_EFFECTS (arg1);
6002 /* Test whether it is preferable two swap two operands, ARG0 and
6003 ARG1, for example because ARG0 is an integer constant and ARG1
6004 isn't. If REORDER is true, only recommend swapping if we can
6005 evaluate the operands in reverse order. */
6008 tree_swap_operands_p (tree arg0, tree arg1, bool reorder)
6010 STRIP_SIGN_NOPS (arg0);
6011 STRIP_SIGN_NOPS (arg1);
6013 if (TREE_CODE (arg1) == INTEGER_CST)
6015 if (TREE_CODE (arg0) == INTEGER_CST)
6018 if (TREE_CODE (arg1) == REAL_CST)
6020 if (TREE_CODE (arg0) == REAL_CST)
6023 if (TREE_CODE (arg1) == COMPLEX_CST)
6025 if (TREE_CODE (arg0) == COMPLEX_CST)
6028 if (TREE_CONSTANT (arg1))
6030 if (TREE_CONSTANT (arg0))
6036 if (reorder && flag_evaluation_order
6037 && (TREE_SIDE_EFFECTS (arg0) || TREE_SIDE_EFFECTS (arg1)))
6045 /* It is preferable to swap two SSA_NAME to ensure a canonical form
6046 for commutative and comparison operators. Ensuring a canonical
6047 form allows the optimizers to find additional redundancies without
6048 having to explicitly check for both orderings. */
6049 if (TREE_CODE (arg0) == SSA_NAME
6050 && TREE_CODE (arg1) == SSA_NAME
6051 && SSA_NAME_VERSION (arg0) > SSA_NAME_VERSION (arg1))
6057 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where
6058 ARG0 is extended to a wider type. */
6061 fold_widened_comparison (enum tree_code code, tree type, tree arg0, tree arg1)
6063 tree arg0_unw = get_unwidened (arg0, NULL_TREE);
6065 tree shorter_type, outer_type;
6069 if (arg0_unw == arg0)
6071 shorter_type = TREE_TYPE (arg0_unw);
6073 if (TYPE_PRECISION (TREE_TYPE (arg0)) <= TYPE_PRECISION (shorter_type))
6076 arg1_unw = get_unwidened (arg1, shorter_type);
6080 /* If possible, express the comparison in the shorter mode. */
6081 if ((code == EQ_EXPR || code == NE_EXPR
6082 || TYPE_UNSIGNED (TREE_TYPE (arg0)) == TYPE_UNSIGNED (shorter_type))
6083 && (TREE_TYPE (arg1_unw) == shorter_type
6084 || (TREE_CODE (arg1_unw) == INTEGER_CST
6085 && TREE_CODE (shorter_type) == INTEGER_TYPE
6086 && int_fits_type_p (arg1_unw, shorter_type))))
6087 return fold (build (code, type, arg0_unw,
6088 fold_convert (shorter_type, arg1_unw)));
6090 if (TREE_CODE (arg1_unw) != INTEGER_CST)
6093 /* If we are comparing with the integer that does not fit into the range
6094 of the shorter type, the result is known. */
6095 outer_type = TREE_TYPE (arg1_unw);
6096 min = lower_bound_in_type (outer_type, shorter_type);
6097 max = upper_bound_in_type (outer_type, shorter_type);
6099 above = integer_nonzerop (fold_relational_const (LT_EXPR, type,
6101 below = integer_nonzerop (fold_relational_const (LT_EXPR, type,
6108 return omit_one_operand (type, integer_zero_node, arg0);
6113 return omit_one_operand (type, integer_one_node, arg0);
6119 return omit_one_operand (type, integer_one_node, arg0);
6121 return omit_one_operand (type, integer_zero_node, arg0);
6126 return omit_one_operand (type, integer_zero_node, arg0);
6128 return omit_one_operand (type, integer_one_node, arg0);
6137 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where for
6138 ARG0 just the signedness is changed. */
6141 fold_sign_changed_comparison (enum tree_code code, tree type,
6142 tree arg0, tree arg1)
6144 tree arg0_inner, tmp;
6145 tree inner_type, outer_type;
6147 if (TREE_CODE (arg0) != NOP_EXPR)
6150 outer_type = TREE_TYPE (arg0);
6151 arg0_inner = TREE_OPERAND (arg0, 0);
6152 inner_type = TREE_TYPE (arg0_inner);
6154 if (TYPE_PRECISION (inner_type) != TYPE_PRECISION (outer_type))
6157 if (TREE_CODE (arg1) != INTEGER_CST
6158 && !(TREE_CODE (arg1) == NOP_EXPR
6159 && TREE_TYPE (TREE_OPERAND (arg1, 0)) == inner_type))
6162 if (TYPE_UNSIGNED (inner_type) != TYPE_UNSIGNED (outer_type)
6167 if (TREE_CODE (arg1) == INTEGER_CST)
6169 tmp = build_int_cst_wide (inner_type,
6170 TREE_INT_CST_LOW (arg1),
6171 TREE_INT_CST_HIGH (arg1));
6172 arg1 = force_fit_type (tmp, 0,
6173 TREE_OVERFLOW (arg1),
6174 TREE_CONSTANT_OVERFLOW (arg1));
6177 arg1 = fold_convert (inner_type, arg1);
6179 return fold (build (code, type, arg0_inner, arg1));
6182 /* Tries to replace &a[idx] CODE s * delta with &a[idx CODE delta], if s is
6183 step of the array. ADDR is the address. MULT is the multiplicative expression.
6184 If the function succeeds, the new address expression is returned. Otherwise
6185 NULL_TREE is returned. */
6188 try_move_mult_to_index (enum tree_code code, tree addr, tree mult)
6190 tree s, delta, step;
6191 tree arg0 = TREE_OPERAND (mult, 0), arg1 = TREE_OPERAND (mult, 1);
6192 tree ref = TREE_OPERAND (addr, 0), pref;
6199 if (TREE_CODE (arg0) == INTEGER_CST)
6204 else if (TREE_CODE (arg1) == INTEGER_CST)
6212 for (;; ref = TREE_OPERAND (ref, 0))
6214 if (TREE_CODE (ref) == ARRAY_REF)
6216 step = array_ref_element_size (ref);
6218 if (TREE_CODE (step) != INTEGER_CST)
6221 itype = TREE_TYPE (step);
6223 /* If the type sizes do not match, we might run into problems
6224 when one of them would overflow. */
6225 if (TYPE_PRECISION (itype) != TYPE_PRECISION (TREE_TYPE (s)))
6228 if (!operand_equal_p (step, fold_convert (itype, s), 0))
6231 delta = fold_convert (itype, delta);
6235 if (!handled_component_p (ref))
6239 /* We found the suitable array reference. So copy everything up to it,
6240 and replace the index. */
6242 pref = TREE_OPERAND (addr, 0);
6243 ret = copy_node (pref);
6248 pref = TREE_OPERAND (pref, 0);
6249 TREE_OPERAND (pos, 0) = copy_node (pref);
6250 pos = TREE_OPERAND (pos, 0);
6253 TREE_OPERAND (pos, 1) = fold (build2 (code, itype,
6254 TREE_OPERAND (pos, 1),
6257 return build1 (ADDR_EXPR, TREE_TYPE (addr), ret);
6261 /* Fold A < X && A + 1 > Y to A < X && A >= Y. Normally A + 1 > Y
6262 means A >= Y && A != MAX, but in this case we know that
6263 A < X <= MAX. INEQ is A + 1 > Y, BOUND is A < X. */
6266 fold_to_nonsharp_ineq_using_bound (tree ineq, tree bound)
6268 tree a, typea, type = TREE_TYPE (ineq), a1, diff, y;
6270 if (TREE_CODE (bound) == LT_EXPR)
6271 a = TREE_OPERAND (bound, 0);
6272 else if (TREE_CODE (bound) == GT_EXPR)
6273 a = TREE_OPERAND (bound, 1);
6277 typea = TREE_TYPE (a);
6278 if (!INTEGRAL_TYPE_P (typea)
6279 && !POINTER_TYPE_P (typea))
6282 if (TREE_CODE (ineq) == LT_EXPR)
6284 a1 = TREE_OPERAND (ineq, 1);
6285 y = TREE_OPERAND (ineq, 0);
6287 else if (TREE_CODE (ineq) == GT_EXPR)
6289 a1 = TREE_OPERAND (ineq, 0);
6290 y = TREE_OPERAND (ineq, 1);
6295 if (TREE_TYPE (a1) != typea)
6298 diff = fold (build2 (MINUS_EXPR, typea, a1, a));
6299 if (!integer_onep (diff))
6302 return fold (build2 (GE_EXPR, type, a, y));
6305 /* Fold complex addition when both components are accessible by parts.
6306 Return non-null if successful. CODE should be PLUS_EXPR for addition,
6307 or MINUS_EXPR for subtraction. */
6310 fold_complex_add (tree type, tree ac, tree bc, enum tree_code code)
6312 tree ar, ai, br, bi, rr, ri, inner_type;
6314 if (TREE_CODE (ac) == COMPLEX_EXPR)
6315 ar = TREE_OPERAND (ac, 0), ai = TREE_OPERAND (ac, 1);
6316 else if (TREE_CODE (ac) == COMPLEX_CST)
6317 ar = TREE_REALPART (ac), ai = TREE_IMAGPART (ac);
6321 if (TREE_CODE (bc) == COMPLEX_EXPR)
6322 br = TREE_OPERAND (bc, 0), bi = TREE_OPERAND (bc, 1);
6323 else if (TREE_CODE (bc) == COMPLEX_CST)
6324 br = TREE_REALPART (bc), bi = TREE_IMAGPART (bc);
6328 inner_type = TREE_TYPE (type);
6330 rr = fold (build2 (code, inner_type, ar, br));
6331 ri = fold (build2 (code, inner_type, ai, bi));
6333 return fold (build2 (COMPLEX_EXPR, type, rr, ri));
6336 /* Perform some simplifications of complex multiplication when one or more
6337 of the components are constants or zeros. Return non-null if successful. */
6340 fold_complex_mult_parts (tree type, tree ar, tree ai, tree br, tree bi)
6342 tree rr, ri, inner_type, zero;
6343 bool ar0, ai0, br0, bi0, bi1;
6345 inner_type = TREE_TYPE (type);
6348 if (SCALAR_FLOAT_TYPE_P (inner_type))
6350 ar0 = ai0 = br0 = bi0 = bi1 = false;
6352 /* We're only interested in +0.0 here, thus we don't use real_zerop. */
6354 if (TREE_CODE (ar) == REAL_CST
6355 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (ar), dconst0))
6356 ar0 = true, zero = ar;
6358 if (TREE_CODE (ai) == REAL_CST
6359 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (ai), dconst0))
6360 ai0 = true, zero = ai;
6362 if (TREE_CODE (br) == REAL_CST
6363 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (br), dconst0))
6364 br0 = true, zero = br;
6366 if (TREE_CODE (bi) == REAL_CST)
6368 if (REAL_VALUES_IDENTICAL (TREE_REAL_CST (bi), dconst0))
6369 bi0 = true, zero = bi;
6370 else if (REAL_VALUES_IDENTICAL (TREE_REAL_CST (bi), dconst1))
6376 ar0 = integer_zerop (ar);
6379 ai0 = integer_zerop (ai);
6382 br0 = integer_zerop (br);
6385 bi0 = integer_zerop (bi);
6392 bi1 = integer_onep (bi);
6395 /* We won't optimize anything below unless something is zero. */
6399 if (ai0 && br0 && bi1)
6404 else if (ai0 && bi0)
6406 rr = fold (build2 (MULT_EXPR, inner_type, ar, br));
6409 else if (ai0 && br0)
6412 ri = fold (build2 (MULT_EXPR, inner_type, ar, bi));
6414 else if (ar0 && bi0)
6417 ri = fold (build2 (MULT_EXPR, inner_type, ai, br));
6419 else if (ar0 && br0)
6421 rr = fold (build2 (MULT_EXPR, inner_type, ai, bi));
6422 rr = fold (build1 (NEGATE_EXPR, inner_type, rr));
6427 rr = fold (build2 (MULT_EXPR, inner_type, ar, br));
6428 ri = fold (build2 (MULT_EXPR, inner_type, ai, br));
6432 rr = fold (build2 (MULT_EXPR, inner_type, ar, br));
6433 ri = fold (build2 (MULT_EXPR, inner_type, ar, bi));
6437 rr = fold (build2 (MULT_EXPR, inner_type, ai, bi));
6438 rr = fold (build1 (NEGATE_EXPR, inner_type, rr));
6439 ri = fold (build2 (MULT_EXPR, inner_type, ar, bi));
6443 rr = fold (build2 (MULT_EXPR, inner_type, ai, bi));
6444 rr = fold (build1 (NEGATE_EXPR, inner_type, rr));
6445 ri = fold (build2 (MULT_EXPR, inner_type, ai, br));
6450 return fold (build2 (COMPLEX_EXPR, type, rr, ri));
6454 fold_complex_mult (tree type, tree ac, tree bc)
6456 tree ar, ai, br, bi;
6458 if (TREE_CODE (ac) == COMPLEX_EXPR)
6459 ar = TREE_OPERAND (ac, 0), ai = TREE_OPERAND (ac, 1);
6460 else if (TREE_CODE (ac) == COMPLEX_CST)
6461 ar = TREE_REALPART (ac), ai = TREE_IMAGPART (ac);
6465 if (TREE_CODE (bc) == COMPLEX_EXPR)
6466 br = TREE_OPERAND (bc, 0), bi = TREE_OPERAND (bc, 1);
6467 else if (TREE_CODE (bc) == COMPLEX_CST)
6468 br = TREE_REALPART (bc), bi = TREE_IMAGPART (bc);
6472 return fold_complex_mult_parts (type, ar, ai, br, bi);
6475 /* Perform some simplifications of complex division when one or more of
6476 the components are constants or zeros. Return non-null if successful. */
6479 fold_complex_div_parts (tree type, tree ar, tree ai, tree br, tree bi,
6480 enum tree_code code)
6482 tree rr, ri, inner_type, zero;
6483 bool ar0, ai0, br0, bi0, bi1;
6485 inner_type = TREE_TYPE (type);
6488 if (SCALAR_FLOAT_TYPE_P (inner_type))
6490 ar0 = ai0 = br0 = bi0 = bi1 = false;
6492 /* We're only interested in +0.0 here, thus we don't use real_zerop. */
6494 if (TREE_CODE (ar) == REAL_CST
6495 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (ar), dconst0))
6496 ar0 = true, zero = ar;
6498 if (TREE_CODE (ai) == REAL_CST
6499 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (ai), dconst0))
6500 ai0 = true, zero = ai;
6502 if (TREE_CODE (br) == REAL_CST
6503 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (br), dconst0))
6504 br0 = true, zero = br;
6506 if (TREE_CODE (bi) == REAL_CST)
6508 if (REAL_VALUES_IDENTICAL (TREE_REAL_CST (bi), dconst0))
6509 bi0 = true, zero = bi;
6510 else if (REAL_VALUES_IDENTICAL (TREE_REAL_CST (bi), dconst1))
6516 ar0 = integer_zerop (ar);
6519 ai0 = integer_zerop (ai);
6522 br0 = integer_zerop (br);
6525 bi0 = integer_zerop (bi);
6532 bi1 = integer_onep (bi);
6535 /* We won't optimize anything below unless something is zero. */
6541 rr = fold (build2 (code, inner_type, ar, br));
6544 else if (ai0 && br0)
6547 ri = fold (build2 (code, inner_type, ar, bi));
6548 ri = fold (build1 (NEGATE_EXPR, inner_type, ri));
6550 else if (ar0 && bi0)
6553 ri = fold (build2 (code, inner_type, ai, br));
6555 else if (ar0 && br0)
6557 rr = fold (build2 (code, inner_type, ai, bi));
6562 rr = fold (build2 (code, inner_type, ar, br));
6563 ri = fold (build2 (code, inner_type, ai, br));
6567 rr = fold (build2 (code, inner_type, ai, bi));
6568 ri = fold (build2 (code, inner_type, ar, bi));
6569 ri = fold (build1 (NEGATE_EXPR, inner_type, ri));
6574 return fold (build2 (COMPLEX_EXPR, type, rr, ri));
6578 fold_complex_div (tree type, tree ac, tree bc, enum tree_code code)
6580 tree ar, ai, br, bi;
6582 if (TREE_CODE (ac) == COMPLEX_EXPR)
6583 ar = TREE_OPERAND (ac, 0), ai = TREE_OPERAND (ac, 1);
6584 else if (TREE_CODE (ac) == COMPLEX_CST)
6585 ar = TREE_REALPART (ac), ai = TREE_IMAGPART (ac);
6589 if (TREE_CODE (bc) == COMPLEX_EXPR)
6590 br = TREE_OPERAND (bc, 0), bi = TREE_OPERAND (bc, 1);
6591 else if (TREE_CODE (bc) == COMPLEX_CST)
6592 br = TREE_REALPART (bc), bi = TREE_IMAGPART (bc);
6596 return fold_complex_div_parts (type, ar, ai, br, bi, code);
6599 /* Fold a unary expression EXPR. Return the folded expression if
6600 folding is successful. Otherwise, return the original
6604 fold_unary (tree expr)
6606 const tree t = expr;
6607 const tree type = TREE_TYPE (expr);
6610 enum tree_code code = TREE_CODE (t);
6611 enum tree_code_class kind = TREE_CODE_CLASS (code);
6613 gcc_assert (IS_EXPR_CODE_CLASS (kind)
6614 && TREE_CODE_LENGTH (code) == 1);
6617 arg0 = op0 = TREE_OPERAND (t, 0);
6620 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
6622 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
6623 STRIP_SIGN_NOPS (arg0);
6627 /* Strip any conversions that don't change the mode. This
6628 is safe for every expression, except for a comparison
6629 expression because its signedness is derived from its
6632 Note that this is done as an internal manipulation within
6633 the constant folder, in order to find the simplest
6634 representation of the arguments so that their form can be
6635 studied. In any cases, the appropriate type conversions
6636 should be put back in the tree that will get out of the
6642 if (TREE_CODE_CLASS (code) == tcc_unary)
6644 if (TREE_CODE (arg0) == COMPOUND_EXPR)
6645 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
6646 fold (build1 (code, type, TREE_OPERAND (arg0, 1))));
6647 else if (TREE_CODE (arg0) == COND_EXPR)
6649 tree arg01 = TREE_OPERAND (arg0, 1);
6650 tree arg02 = TREE_OPERAND (arg0, 2);
6651 if (! VOID_TYPE_P (TREE_TYPE (arg01)))
6652 arg01 = fold (build1 (code, type, arg01));
6653 if (! VOID_TYPE_P (TREE_TYPE (arg02)))
6654 arg02 = fold (build1 (code, type, arg02));
6655 tem = fold (build3 (COND_EXPR, type, TREE_OPERAND (arg0, 0),
6658 /* If this was a conversion, and all we did was to move into
6659 inside the COND_EXPR, bring it back out. But leave it if
6660 it is a conversion from integer to integer and the
6661 result precision is no wider than a word since such a
6662 conversion is cheap and may be optimized away by combine,
6663 while it couldn't if it were outside the COND_EXPR. Then return
6664 so we don't get into an infinite recursion loop taking the
6665 conversion out and then back in. */
6667 if ((code == NOP_EXPR || code == CONVERT_EXPR
6668 || code == NON_LVALUE_EXPR)
6669 && TREE_CODE (tem) == COND_EXPR
6670 && TREE_CODE (TREE_OPERAND (tem, 1)) == code
6671 && TREE_CODE (TREE_OPERAND (tem, 2)) == code
6672 && ! VOID_TYPE_P (TREE_OPERAND (tem, 1))
6673 && ! VOID_TYPE_P (TREE_OPERAND (tem, 2))
6674 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))
6675 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 2), 0)))
6676 && (! (INTEGRAL_TYPE_P (TREE_TYPE (tem))
6678 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))))
6679 && TYPE_PRECISION (TREE_TYPE (tem)) <= BITS_PER_WORD)
6680 || flag_syntax_only))
6681 tem = build1 (code, type,
6683 TREE_TYPE (TREE_OPERAND
6684 (TREE_OPERAND (tem, 1), 0)),
6685 TREE_OPERAND (tem, 0),
6686 TREE_OPERAND (TREE_OPERAND (tem, 1), 0),
6687 TREE_OPERAND (TREE_OPERAND (tem, 2), 0)));
6690 else if (COMPARISON_CLASS_P (arg0))
6692 if (TREE_CODE (type) == BOOLEAN_TYPE)
6694 arg0 = copy_node (arg0);
6695 TREE_TYPE (arg0) = type;
6698 else if (TREE_CODE (type) != INTEGER_TYPE)
6699 return fold (build3 (COND_EXPR, type, arg0,
6700 fold (build1 (code, type,
6702 fold (build1 (code, type,
6703 integer_zero_node))));
6712 case FIX_TRUNC_EXPR:
6714 case FIX_FLOOR_EXPR:
6715 case FIX_ROUND_EXPR:
6716 if (TREE_TYPE (op0) == type)
6719 /* Handle cases of two conversions in a row. */
6720 if (TREE_CODE (op0) == NOP_EXPR
6721 || TREE_CODE (op0) == CONVERT_EXPR)
6723 tree inside_type = TREE_TYPE (TREE_OPERAND (op0, 0));
6724 tree inter_type = TREE_TYPE (op0);
6725 int inside_int = INTEGRAL_TYPE_P (inside_type);
6726 int inside_ptr = POINTER_TYPE_P (inside_type);
6727 int inside_float = FLOAT_TYPE_P (inside_type);
6728 unsigned int inside_prec = TYPE_PRECISION (inside_type);
6729 int inside_unsignedp = TYPE_UNSIGNED (inside_type);
6730 int inter_int = INTEGRAL_TYPE_P (inter_type);
6731 int inter_ptr = POINTER_TYPE_P (inter_type);
6732 int inter_float = FLOAT_TYPE_P (inter_type);
6733 unsigned int inter_prec = TYPE_PRECISION (inter_type);
6734 int inter_unsignedp = TYPE_UNSIGNED (inter_type);
6735 int final_int = INTEGRAL_TYPE_P (type);
6736 int final_ptr = POINTER_TYPE_P (type);
6737 int final_float = FLOAT_TYPE_P (type);
6738 unsigned int final_prec = TYPE_PRECISION (type);
6739 int final_unsignedp = TYPE_UNSIGNED (type);
6741 /* In addition to the cases of two conversions in a row
6742 handled below, if we are converting something to its own
6743 type via an object of identical or wider precision, neither
6744 conversion is needed. */
6745 if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (type)
6746 && ((inter_int && final_int) || (inter_float && final_float))
6747 && inter_prec >= final_prec)
6748 return fold (build1 (code, type, TREE_OPERAND (op0, 0)));
6750 /* Likewise, if the intermediate and final types are either both
6751 float or both integer, we don't need the middle conversion if
6752 it is wider than the final type and doesn't change the signedness
6753 (for integers). Avoid this if the final type is a pointer
6754 since then we sometimes need the inner conversion. Likewise if
6755 the outer has a precision not equal to the size of its mode. */
6756 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
6757 || (inter_float && inside_float))
6758 && inter_prec >= inside_prec
6759 && (inter_float || inter_unsignedp == inside_unsignedp)
6760 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
6761 && TYPE_MODE (type) == TYPE_MODE (inter_type))
6763 return fold (build1 (code, type, TREE_OPERAND (op0, 0)));
6765 /* If we have a sign-extension of a zero-extended value, we can
6766 replace that by a single zero-extension. */
6767 if (inside_int && inter_int && final_int
6768 && inside_prec < inter_prec && inter_prec < final_prec
6769 && inside_unsignedp && !inter_unsignedp)
6770 return fold (build1 (code, type, TREE_OPERAND (op0, 0)));
6772 /* Two conversions in a row are not needed unless:
6773 - some conversion is floating-point (overstrict for now), or
6774 - the intermediate type is narrower than both initial and
6776 - the intermediate type and innermost type differ in signedness,
6777 and the outermost type is wider than the intermediate, or
6778 - the initial type is a pointer type and the precisions of the
6779 intermediate and final types differ, or
6780 - the final type is a pointer type and the precisions of the
6781 initial and intermediate types differ. */
6782 if (! inside_float && ! inter_float && ! final_float
6783 && (inter_prec > inside_prec || inter_prec > final_prec)
6784 && ! (inside_int && inter_int
6785 && inter_unsignedp != inside_unsignedp
6786 && inter_prec < final_prec)
6787 && ((inter_unsignedp && inter_prec > inside_prec)
6788 == (final_unsignedp && final_prec > inter_prec))
6789 && ! (inside_ptr && inter_prec != final_prec)
6790 && ! (final_ptr && inside_prec != inter_prec)
6791 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
6792 && TYPE_MODE (type) == TYPE_MODE (inter_type))
6794 return fold (build1 (code, type, TREE_OPERAND (op0, 0)));
6797 if (TREE_CODE (op0) == MODIFY_EXPR
6798 && TREE_CONSTANT (TREE_OPERAND (op0, 1))
6799 /* Detect assigning a bitfield. */
6800 && !(TREE_CODE (TREE_OPERAND (op0, 0)) == COMPONENT_REF
6801 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (op0, 0), 1))))
6803 /* Don't leave an assignment inside a conversion
6804 unless assigning a bitfield. */
6805 tem = copy_node (t);
6806 TREE_OPERAND (tem, 0) = TREE_OPERAND (op0, 1);
6807 /* First do the assignment, then return converted constant. */
6808 tem = build2 (COMPOUND_EXPR, TREE_TYPE (tem), op0, fold (tem));
6809 TREE_NO_WARNING (tem) = 1;
6810 TREE_USED (tem) = 1;
6814 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
6815 constants (if x has signed type, the sign bit cannot be set
6816 in c). This folds extension into the BIT_AND_EXPR. */
6817 if (INTEGRAL_TYPE_P (type)
6818 && TREE_CODE (type) != BOOLEAN_TYPE
6819 && TREE_CODE (op0) == BIT_AND_EXPR
6820 && TREE_CODE (TREE_OPERAND (op0, 1)) == INTEGER_CST)
6823 tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
6826 if (TYPE_UNSIGNED (TREE_TYPE (and))
6827 || (TYPE_PRECISION (type)
6828 <= TYPE_PRECISION (TREE_TYPE (and))))
6830 else if (TYPE_PRECISION (TREE_TYPE (and1))
6831 <= HOST_BITS_PER_WIDE_INT
6832 && host_integerp (and1, 1))
6834 unsigned HOST_WIDE_INT cst;
6836 cst = tree_low_cst (and1, 1);
6837 cst &= (HOST_WIDE_INT) -1
6838 << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
6839 change = (cst == 0);
6840 #ifdef LOAD_EXTEND_OP
6842 && !flag_syntax_only
6843 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
6846 tree uns = lang_hooks.types.unsigned_type (TREE_TYPE (and0));
6847 and0 = fold_convert (uns, and0);
6848 and1 = fold_convert (uns, and1);
6854 tem = build_int_cst_wide (type, TREE_INT_CST_LOW (and1),
6855 TREE_INT_CST_HIGH (and1));
6856 tem = force_fit_type (tem, 0, TREE_OVERFLOW (and1),
6857 TREE_CONSTANT_OVERFLOW (and1));
6858 return fold (build2 (BIT_AND_EXPR, type,
6859 fold_convert (type, and0), tem));
6863 /* Convert (T1)((T2)X op Y) into (T1)X op Y, for pointer types T1 and
6864 T2 being pointers to types of the same size. */
6865 if (POINTER_TYPE_P (type)
6866 && BINARY_CLASS_P (arg0)
6867 && TREE_CODE (TREE_OPERAND (arg0, 0)) == NOP_EXPR
6868 && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 0))))
6870 tree arg00 = TREE_OPERAND (arg0, 0);
6872 tree t1 = TREE_TYPE (arg00);
6873 tree tt0 = TREE_TYPE (t0);
6874 tree tt1 = TREE_TYPE (t1);
6875 tree s0 = TYPE_SIZE (tt0);
6876 tree s1 = TYPE_SIZE (tt1);
6878 if (s0 && s1 && operand_equal_p (s0, s1, OEP_ONLY_CONST))
6879 return build2 (TREE_CODE (arg0), t0, fold_convert (t0, arg00),
6880 TREE_OPERAND (arg0, 1));
6883 tem = fold_convert_const (code, type, arg0);
6884 return tem ? tem : t;
6886 case VIEW_CONVERT_EXPR:
6887 if (TREE_CODE (op0) == VIEW_CONVERT_EXPR)
6888 return build1 (VIEW_CONVERT_EXPR, type, TREE_OPERAND (op0, 0));
6892 if (negate_expr_p (arg0))
6893 return fold_convert (type, negate_expr (arg0));
6894 /* Convert - (~A) to A + 1. */
6895 if (INTEGRAL_TYPE_P (type) && TREE_CODE (arg0) == BIT_NOT_EXPR)
6896 return fold (build2 (PLUS_EXPR, type, TREE_OPERAND (arg0, 0),
6897 build_int_cst (type, 1)));
6901 if (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST)
6902 return fold_abs_const (arg0, type);
6903 else if (TREE_CODE (arg0) == NEGATE_EXPR)
6904 return fold (build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0)));
6905 /* Convert fabs((double)float) into (double)fabsf(float). */
6906 else if (TREE_CODE (arg0) == NOP_EXPR
6907 && TREE_CODE (type) == REAL_TYPE)
6909 tree targ0 = strip_float_extensions (arg0);
6911 return fold_convert (type, fold (build1 (ABS_EXPR,
6915 else if (tree_expr_nonnegative_p (arg0))
6918 /* Strip sign ops from argument. */
6919 if (TREE_CODE (type) == REAL_TYPE)
6921 tem = fold_strip_sign_ops (arg0);
6923 return fold (build1 (ABS_EXPR, type, fold_convert (type, tem)));
6928 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
6929 return fold_convert (type, arg0);
6930 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
6931 return build2 (COMPLEX_EXPR, type,
6932 TREE_OPERAND (arg0, 0),
6933 negate_expr (TREE_OPERAND (arg0, 1)));
6934 else if (TREE_CODE (arg0) == COMPLEX_CST)
6935 return build_complex (type, TREE_REALPART (arg0),
6936 negate_expr (TREE_IMAGPART (arg0)));
6937 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
6938 return fold (build2 (TREE_CODE (arg0), type,
6939 fold (build1 (CONJ_EXPR, type,
6940 TREE_OPERAND (arg0, 0))),
6941 fold (build1 (CONJ_EXPR, type,
6942 TREE_OPERAND (arg0, 1)))));
6943 else if (TREE_CODE (arg0) == CONJ_EXPR)
6944 return TREE_OPERAND (arg0, 0);
6948 if (TREE_CODE (arg0) == INTEGER_CST)
6949 return fold_not_const (arg0, type);
6950 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
6951 return TREE_OPERAND (arg0, 0);
6952 /* Convert ~ (-A) to A - 1. */
6953 else if (INTEGRAL_TYPE_P (type) && TREE_CODE (arg0) == NEGATE_EXPR)
6954 return fold (build2 (MINUS_EXPR, type, TREE_OPERAND (arg0, 0),
6955 build_int_cst (type, 1)));
6956 /* Convert ~ (A - 1) or ~ (A + -1) to -A. */
6957 else if (INTEGRAL_TYPE_P (type)
6958 && ((TREE_CODE (arg0) == MINUS_EXPR
6959 && integer_onep (TREE_OPERAND (arg0, 1)))
6960 || (TREE_CODE (arg0) == PLUS_EXPR
6961 && integer_all_onesp (TREE_OPERAND (arg0, 1)))))
6962 return fold (build1 (NEGATE_EXPR, type, TREE_OPERAND (arg0, 0)));
6965 case TRUTH_NOT_EXPR:
6966 /* The argument to invert_truthvalue must have Boolean type. */
6967 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
6968 arg0 = fold_convert (boolean_type_node, arg0);
6970 /* Note that the operand of this must be an int
6971 and its values must be 0 or 1.
6972 ("true" is a fixed value perhaps depending on the language,
6973 but we don't handle values other than 1 correctly yet.) */
6974 tem = invert_truthvalue (arg0);
6975 /* Avoid infinite recursion. */
6976 if (TREE_CODE (tem) == TRUTH_NOT_EXPR)
6978 return fold_convert (type, tem);
6981 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
6983 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
6984 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
6985 TREE_OPERAND (arg0, 1));
6986 else if (TREE_CODE (arg0) == COMPLEX_CST)
6987 return TREE_REALPART (arg0);
6988 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
6989 return fold (build2 (TREE_CODE (arg0), type,
6990 fold (build1 (REALPART_EXPR, type,
6991 TREE_OPERAND (arg0, 0))),
6992 fold (build1 (REALPART_EXPR, type,
6993 TREE_OPERAND (arg0, 1)))));
6997 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
6998 return fold_convert (type, integer_zero_node);
6999 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
7000 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
7001 TREE_OPERAND (arg0, 0));
7002 else if (TREE_CODE (arg0) == COMPLEX_CST)
7003 return TREE_IMAGPART (arg0);
7004 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7005 return fold (build2 (TREE_CODE (arg0), type,
7006 fold (build1 (IMAGPART_EXPR, type,
7007 TREE_OPERAND (arg0, 0))),
7008 fold (build1 (IMAGPART_EXPR, type,
7009 TREE_OPERAND (arg0, 1)))));
7014 } /* switch (code) */
7017 /* Perform constant folding and related simplification of EXPR.
7018 The related simplifications include x*1 => x, x*0 => 0, etc.,
7019 and application of the associative law.
7020 NOP_EXPR conversions may be removed freely (as long as we
7021 are careful not to change the type of the overall expression).
7022 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
7023 but we can constant-fold them if they have constant operands. */
7025 #ifdef ENABLE_FOLD_CHECKING
7026 # define fold(x) fold_1 (x)
7027 static tree fold_1 (tree);
7033 const tree t = expr;
7034 const tree type = TREE_TYPE (expr);
7035 tree t1 = NULL_TREE;
7037 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
7038 enum tree_code code = TREE_CODE (t);
7039 enum tree_code_class kind = TREE_CODE_CLASS (code);
7041 /* WINS will be nonzero when the switch is done
7042 if all operands are constant. */
7045 /* Return right away if a constant. */
7046 if (kind == tcc_constant)
7049 if (IS_EXPR_CODE_CLASS (kind))
7051 switch (TREE_CODE_LENGTH (code))
7054 return fold_unary (expr);
7060 if (IS_EXPR_CODE_CLASS (kind))
7062 int len = TREE_CODE_LENGTH (code);
7064 for (i = 0; i < len; i++)
7066 tree op = TREE_OPERAND (t, i);
7070 continue; /* Valid for CALL_EXPR, at least. */
7072 /* Strip any conversions that don't change the mode. This is
7073 safe for every expression, except for a comparison expression
7074 because its signedness is derived from its operands. So, in
7075 the latter case, only strip conversions that don't change the
7078 Note that this is done as an internal manipulation within the
7079 constant folder, in order to find the simplest representation
7080 of the arguments so that their form can be studied. In any
7081 cases, the appropriate type conversions should be put back in
7082 the tree that will get out of the constant folder. */
7083 if (kind == tcc_comparison)
7084 STRIP_SIGN_NOPS (op);
7088 if (TREE_CODE (op) == COMPLEX_CST)
7089 subop = TREE_REALPART (op);
7093 if (TREE_CODE (subop) != INTEGER_CST
7094 && TREE_CODE (subop) != REAL_CST)
7095 /* Note that TREE_CONSTANT isn't enough:
7096 static var addresses are constant but we can't
7097 do arithmetic on them. */
7107 /* If this is a commutative operation, and ARG0 is a constant, move it
7108 to ARG1 to reduce the number of tests below. */
7109 if (commutative_tree_code (code)
7110 && tree_swap_operands_p (arg0, arg1, true))
7111 return fold (build2 (code, type, TREE_OPERAND (t, 1),
7112 TREE_OPERAND (t, 0)));
7114 /* Now WINS is set as described above,
7115 ARG0 is the first operand of EXPR,
7116 and ARG1 is the second operand (if it has more than one operand).
7118 First check for cases where an arithmetic operation is applied to a
7119 compound, conditional, or comparison operation. Push the arithmetic
7120 operation inside the compound or conditional to see if any folding
7121 can then be done. Convert comparison to conditional for this purpose.
7122 The also optimizes non-constant cases that used to be done in
7125 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
7126 one of the operands is a comparison and the other is a comparison, a
7127 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
7128 code below would make the expression more complex. Change it to a
7129 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
7130 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
7132 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
7133 || code == EQ_EXPR || code == NE_EXPR)
7134 && ((truth_value_p (TREE_CODE (arg0))
7135 && (truth_value_p (TREE_CODE (arg1))
7136 || (TREE_CODE (arg1) == BIT_AND_EXPR
7137 && integer_onep (TREE_OPERAND (arg1, 1)))))
7138 || (truth_value_p (TREE_CODE (arg1))
7139 && (truth_value_p (TREE_CODE (arg0))
7140 || (TREE_CODE (arg0) == BIT_AND_EXPR
7141 && integer_onep (TREE_OPERAND (arg0, 1)))))))
7143 tem = fold (build2 (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
7144 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
7146 type, fold_convert (boolean_type_node, arg0),
7147 fold_convert (boolean_type_node, arg1)));
7149 if (code == EQ_EXPR)
7150 tem = invert_truthvalue (tem);
7155 if (TREE_CODE_CLASS (code) == tcc_comparison
7156 && TREE_CODE (arg0) == COMPOUND_EXPR)
7157 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
7158 fold (build2 (code, type, TREE_OPERAND (arg0, 1), arg1)));
7159 else if (TREE_CODE_CLASS (code) == tcc_comparison
7160 && TREE_CODE (arg1) == COMPOUND_EXPR)
7161 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
7162 fold (build2 (code, type, arg0, TREE_OPERAND (arg1, 1))));
7163 else if (TREE_CODE_CLASS (code) == tcc_binary
7164 || TREE_CODE_CLASS (code) == tcc_comparison)
7166 if (TREE_CODE (arg0) == COMPOUND_EXPR)
7167 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
7168 fold (build2 (code, type, TREE_OPERAND (arg0, 1),
7170 if (TREE_CODE (arg1) == COMPOUND_EXPR
7171 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
7172 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
7173 fold (build2 (code, type,
7174 arg0, TREE_OPERAND (arg1, 1))));
7176 if (TREE_CODE (arg0) == COND_EXPR || COMPARISON_CLASS_P (arg0))
7178 tem = fold_binary_op_with_conditional_arg (t, code, arg0, arg1,
7179 /*cond_first_p=*/1);
7180 if (tem != NULL_TREE)
7184 if (TREE_CODE (arg1) == COND_EXPR || COMPARISON_CLASS_P (arg1))
7186 tem = fold_binary_op_with_conditional_arg (t, code, arg1, arg0,
7187 /*cond_first_p=*/0);
7188 if (tem != NULL_TREE)
7196 return fold (DECL_INITIAL (t));
7199 if (TREE_CODE (arg0) == CONSTRUCTOR
7200 && ! type_contains_placeholder_p (TREE_TYPE (arg0)))
7202 tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0));
7204 return TREE_VALUE (m);
7209 if (TREE_CONSTANT (t) != wins)
7211 tem = copy_node (t);
7212 TREE_CONSTANT (tem) = wins;
7213 TREE_INVARIANT (tem) = wins;
7219 /* A + (-B) -> A - B */
7220 if (TREE_CODE (arg1) == NEGATE_EXPR)
7221 return fold (build2 (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
7222 /* (-A) + B -> B - A */
7223 if (TREE_CODE (arg0) == NEGATE_EXPR
7224 && reorder_operands_p (TREE_OPERAND (arg0, 0), arg1))
7225 return fold (build2 (MINUS_EXPR, type, arg1, TREE_OPERAND (arg0, 0)));
7227 if (TREE_CODE (type) == COMPLEX_TYPE)
7229 tem = fold_complex_add (type, arg0, arg1, PLUS_EXPR);
7234 if (! FLOAT_TYPE_P (type))
7236 if (integer_zerop (arg1))
7237 return non_lvalue (fold_convert (type, arg0));
7239 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
7240 with a constant, and the two constants have no bits in common,
7241 we should treat this as a BIT_IOR_EXPR since this may produce more
7243 if (TREE_CODE (arg0) == BIT_AND_EXPR
7244 && TREE_CODE (arg1) == BIT_AND_EXPR
7245 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7246 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
7247 && integer_zerop (const_binop (BIT_AND_EXPR,
7248 TREE_OPERAND (arg0, 1),
7249 TREE_OPERAND (arg1, 1), 0)))
7251 code = BIT_IOR_EXPR;
7255 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
7256 (plus (plus (mult) (mult)) (foo)) so that we can
7257 take advantage of the factoring cases below. */
7258 if (((TREE_CODE (arg0) == PLUS_EXPR
7259 || TREE_CODE (arg0) == MINUS_EXPR)
7260 && TREE_CODE (arg1) == MULT_EXPR)
7261 || ((TREE_CODE (arg1) == PLUS_EXPR
7262 || TREE_CODE (arg1) == MINUS_EXPR)
7263 && TREE_CODE (arg0) == MULT_EXPR))
7265 tree parg0, parg1, parg, marg;
7266 enum tree_code pcode;
7268 if (TREE_CODE (arg1) == MULT_EXPR)
7269 parg = arg0, marg = arg1;
7271 parg = arg1, marg = arg0;
7272 pcode = TREE_CODE (parg);
7273 parg0 = TREE_OPERAND (parg, 0);
7274 parg1 = TREE_OPERAND (parg, 1);
7278 if (TREE_CODE (parg0) == MULT_EXPR
7279 && TREE_CODE (parg1) != MULT_EXPR)
7280 return fold (build2 (pcode, type,
7281 fold (build2 (PLUS_EXPR, type,
7282 fold_convert (type, parg0),
7283 fold_convert (type, marg))),
7284 fold_convert (type, parg1)));
7285 if (TREE_CODE (parg0) != MULT_EXPR
7286 && TREE_CODE (parg1) == MULT_EXPR)
7287 return fold (build2 (PLUS_EXPR, type,
7288 fold_convert (type, parg0),
7289 fold (build2 (pcode, type,
7290 fold_convert (type, marg),
7295 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR)
7297 tree arg00, arg01, arg10, arg11;
7298 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
7300 /* (A * C) + (B * C) -> (A+B) * C.
7301 We are most concerned about the case where C is a constant,
7302 but other combinations show up during loop reduction. Since
7303 it is not difficult, try all four possibilities. */
7305 arg00 = TREE_OPERAND (arg0, 0);
7306 arg01 = TREE_OPERAND (arg0, 1);
7307 arg10 = TREE_OPERAND (arg1, 0);
7308 arg11 = TREE_OPERAND (arg1, 1);
7311 if (operand_equal_p (arg01, arg11, 0))
7312 same = arg01, alt0 = arg00, alt1 = arg10;
7313 else if (operand_equal_p (arg00, arg10, 0))
7314 same = arg00, alt0 = arg01, alt1 = arg11;
7315 else if (operand_equal_p (arg00, arg11, 0))
7316 same = arg00, alt0 = arg01, alt1 = arg10;
7317 else if (operand_equal_p (arg01, arg10, 0))
7318 same = arg01, alt0 = arg00, alt1 = arg11;
7320 /* No identical multiplicands; see if we can find a common
7321 power-of-two factor in non-power-of-two multiplies. This
7322 can help in multi-dimensional array access. */
7323 else if (TREE_CODE (arg01) == INTEGER_CST
7324 && TREE_CODE (arg11) == INTEGER_CST
7325 && TREE_INT_CST_HIGH (arg01) == 0
7326 && TREE_INT_CST_HIGH (arg11) == 0)
7328 HOST_WIDE_INT int01, int11, tmp;
7329 int01 = TREE_INT_CST_LOW (arg01);
7330 int11 = TREE_INT_CST_LOW (arg11);
7332 /* Move min of absolute values to int11. */
7333 if ((int01 >= 0 ? int01 : -int01)
7334 < (int11 >= 0 ? int11 : -int11))
7336 tmp = int01, int01 = int11, int11 = tmp;
7337 alt0 = arg00, arg00 = arg10, arg10 = alt0;
7338 alt0 = arg01, arg01 = arg11, arg11 = alt0;
7341 if (exact_log2 (int11) > 0 && int01 % int11 == 0)
7343 alt0 = fold (build2 (MULT_EXPR, type, arg00,
7344 build_int_cst (NULL_TREE,
7352 return fold (build2 (MULT_EXPR, type,
7353 fold (build2 (PLUS_EXPR, type,
7354 fold_convert (type, alt0),
7355 fold_convert (type, alt1))),
7359 /* Try replacing &a[i1] + c * i2 with &a[i1 + i2], if c is step
7360 of the array. Loop optimizer sometimes produce this type of
7362 if (TREE_CODE (arg0) == ADDR_EXPR
7363 && TREE_CODE (arg1) == MULT_EXPR)
7365 tem = try_move_mult_to_index (PLUS_EXPR, arg0, arg1);
7367 return fold_convert (type, fold (tem));
7369 else if (TREE_CODE (arg1) == ADDR_EXPR
7370 && TREE_CODE (arg0) == MULT_EXPR)
7372 tem = try_move_mult_to_index (PLUS_EXPR, arg1, arg0);
7374 return fold_convert (type, fold (tem));
7379 /* See if ARG1 is zero and X + ARG1 reduces to X. */
7380 if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
7381 return non_lvalue (fold_convert (type, arg0));
7383 /* Likewise if the operands are reversed. */
7384 if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
7385 return non_lvalue (fold_convert (type, arg1));
7387 /* Convert X + -C into X - C. */
7388 if (TREE_CODE (arg1) == REAL_CST
7389 && REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1)))
7391 tem = fold_negate_const (arg1, type);
7392 if (!TREE_OVERFLOW (arg1) || !flag_trapping_math)
7393 return fold (build2 (MINUS_EXPR, type,
7394 fold_convert (type, arg0),
7395 fold_convert (type, tem)));
7398 /* Convert x+x into x*2.0. */
7399 if (operand_equal_p (arg0, arg1, 0)
7400 && SCALAR_FLOAT_TYPE_P (type))
7401 return fold (build2 (MULT_EXPR, type, arg0,
7402 build_real (type, dconst2)));
7404 /* Convert x*c+x into x*(c+1). */
7405 if (flag_unsafe_math_optimizations
7406 && TREE_CODE (arg0) == MULT_EXPR
7407 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
7408 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0, 1))
7409 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
7413 c = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
7414 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
7415 return fold (build2 (MULT_EXPR, type, arg1,
7416 build_real (type, c)));
7419 /* Convert x+x*c into x*(c+1). */
7420 if (flag_unsafe_math_optimizations
7421 && TREE_CODE (arg1) == MULT_EXPR
7422 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST
7423 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1, 1))
7424 && operand_equal_p (TREE_OPERAND (arg1, 0), arg0, 0))
7428 c = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
7429 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
7430 return fold (build2 (MULT_EXPR, type, arg0,
7431 build_real (type, c)));
7434 /* Convert x*c1+x*c2 into x*(c1+c2). */
7435 if (flag_unsafe_math_optimizations
7436 && TREE_CODE (arg0) == MULT_EXPR
7437 && TREE_CODE (arg1) == MULT_EXPR
7438 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
7439 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0, 1))
7440 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST
7441 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1, 1))
7442 && operand_equal_p (TREE_OPERAND (arg0, 0),
7443 TREE_OPERAND (arg1, 0), 0))
7445 REAL_VALUE_TYPE c1, c2;
7447 c1 = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
7448 c2 = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
7449 real_arithmetic (&c1, PLUS_EXPR, &c1, &c2);
7450 return fold (build2 (MULT_EXPR, type,
7451 TREE_OPERAND (arg0, 0),
7452 build_real (type, c1)));
7454 /* Convert a + (b*c + d*e) into (a + b*c) + d*e. */
7455 if (flag_unsafe_math_optimizations
7456 && TREE_CODE (arg1) == PLUS_EXPR
7457 && TREE_CODE (arg0) != MULT_EXPR)
7459 tree tree10 = TREE_OPERAND (arg1, 0);
7460 tree tree11 = TREE_OPERAND (arg1, 1);
7461 if (TREE_CODE (tree11) == MULT_EXPR
7462 && TREE_CODE (tree10) == MULT_EXPR)
7465 tree0 = fold (build2 (PLUS_EXPR, type, arg0, tree10));
7466 return fold (build2 (PLUS_EXPR, type, tree0, tree11));
7469 /* Convert (b*c + d*e) + a into b*c + (d*e +a). */
7470 if (flag_unsafe_math_optimizations
7471 && TREE_CODE (arg0) == PLUS_EXPR
7472 && TREE_CODE (arg1) != MULT_EXPR)
7474 tree tree00 = TREE_OPERAND (arg0, 0);
7475 tree tree01 = TREE_OPERAND (arg0, 1);
7476 if (TREE_CODE (tree01) == MULT_EXPR
7477 && TREE_CODE (tree00) == MULT_EXPR)
7480 tree0 = fold (build2 (PLUS_EXPR, type, tree01, arg1));
7481 return fold (build2 (PLUS_EXPR, type, tree00, tree0));
7487 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
7488 is a rotate of A by C1 bits. */
7489 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
7490 is a rotate of A by B bits. */
7492 enum tree_code code0, code1;
7493 code0 = TREE_CODE (arg0);
7494 code1 = TREE_CODE (arg1);
7495 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
7496 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
7497 && operand_equal_p (TREE_OPERAND (arg0, 0),
7498 TREE_OPERAND (arg1, 0), 0)
7499 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
7501 tree tree01, tree11;
7502 enum tree_code code01, code11;
7504 tree01 = TREE_OPERAND (arg0, 1);
7505 tree11 = TREE_OPERAND (arg1, 1);
7506 STRIP_NOPS (tree01);
7507 STRIP_NOPS (tree11);
7508 code01 = TREE_CODE (tree01);
7509 code11 = TREE_CODE (tree11);
7510 if (code01 == INTEGER_CST
7511 && code11 == INTEGER_CST
7512 && TREE_INT_CST_HIGH (tree01) == 0
7513 && TREE_INT_CST_HIGH (tree11) == 0
7514 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
7515 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
7516 return build2 (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
7517 code0 == LSHIFT_EXPR ? tree01 : tree11);
7518 else if (code11 == MINUS_EXPR)
7520 tree tree110, tree111;
7521 tree110 = TREE_OPERAND (tree11, 0);
7522 tree111 = TREE_OPERAND (tree11, 1);
7523 STRIP_NOPS (tree110);
7524 STRIP_NOPS (tree111);
7525 if (TREE_CODE (tree110) == INTEGER_CST
7526 && 0 == compare_tree_int (tree110,
7528 (TREE_TYPE (TREE_OPERAND
7530 && operand_equal_p (tree01, tree111, 0))
7531 return build2 ((code0 == LSHIFT_EXPR
7534 type, TREE_OPERAND (arg0, 0), tree01);
7536 else if (code01 == MINUS_EXPR)
7538 tree tree010, tree011;
7539 tree010 = TREE_OPERAND (tree01, 0);
7540 tree011 = TREE_OPERAND (tree01, 1);
7541 STRIP_NOPS (tree010);
7542 STRIP_NOPS (tree011);
7543 if (TREE_CODE (tree010) == INTEGER_CST
7544 && 0 == compare_tree_int (tree010,
7546 (TREE_TYPE (TREE_OPERAND
7548 && operand_equal_p (tree11, tree011, 0))
7549 return build2 ((code0 != LSHIFT_EXPR
7552 type, TREE_OPERAND (arg0, 0), tree11);
7558 /* In most languages, can't associate operations on floats through
7559 parentheses. Rather than remember where the parentheses were, we
7560 don't associate floats at all, unless the user has specified
7561 -funsafe-math-optimizations. */
7564 && (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
7566 tree var0, con0, lit0, minus_lit0;
7567 tree var1, con1, lit1, minus_lit1;
7569 /* Split both trees into variables, constants, and literals. Then
7570 associate each group together, the constants with literals,
7571 then the result with variables. This increases the chances of
7572 literals being recombined later and of generating relocatable
7573 expressions for the sum of a constant and literal. */
7574 var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
7575 var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
7576 code == MINUS_EXPR);
7578 /* Only do something if we found more than two objects. Otherwise,
7579 nothing has changed and we risk infinite recursion. */
7580 if (2 < ((var0 != 0) + (var1 != 0)
7581 + (con0 != 0) + (con1 != 0)
7582 + (lit0 != 0) + (lit1 != 0)
7583 + (minus_lit0 != 0) + (minus_lit1 != 0)))
7585 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
7586 if (code == MINUS_EXPR)
7589 var0 = associate_trees (var0, var1, code, type);
7590 con0 = associate_trees (con0, con1, code, type);
7591 lit0 = associate_trees (lit0, lit1, code, type);
7592 minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
7594 /* Preserve the MINUS_EXPR if the negative part of the literal is
7595 greater than the positive part. Otherwise, the multiplicative
7596 folding code (i.e extract_muldiv) may be fooled in case
7597 unsigned constants are subtracted, like in the following
7598 example: ((X*2 + 4) - 8U)/2. */
7599 if (minus_lit0 && lit0)
7601 if (TREE_CODE (lit0) == INTEGER_CST
7602 && TREE_CODE (minus_lit0) == INTEGER_CST
7603 && tree_int_cst_lt (lit0, minus_lit0))
7605 minus_lit0 = associate_trees (minus_lit0, lit0,
7611 lit0 = associate_trees (lit0, minus_lit0,
7619 return fold_convert (type,
7620 associate_trees (var0, minus_lit0,
7624 con0 = associate_trees (con0, minus_lit0,
7626 return fold_convert (type,
7627 associate_trees (var0, con0,
7632 con0 = associate_trees (con0, lit0, code, type);
7633 return fold_convert (type, associate_trees (var0, con0,
7640 t1 = const_binop (code, arg0, arg1, 0);
7641 if (t1 != NULL_TREE)
7643 /* The return value should always have
7644 the same type as the original expression. */
7645 if (TREE_TYPE (t1) != type)
7646 t1 = fold_convert (type, t1);
7653 /* A - (-B) -> A + B */
7654 if (TREE_CODE (arg1) == NEGATE_EXPR)
7655 return fold (build2 (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
7656 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
7657 if (TREE_CODE (arg0) == NEGATE_EXPR
7658 && (FLOAT_TYPE_P (type)
7659 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv))
7660 && negate_expr_p (arg1)
7661 && reorder_operands_p (arg0, arg1))
7662 return fold (build2 (MINUS_EXPR, type, negate_expr (arg1),
7663 TREE_OPERAND (arg0, 0)));
7665 if (TREE_CODE (type) == COMPLEX_TYPE)
7667 tem = fold_complex_add (type, arg0, arg1, MINUS_EXPR);
7672 if (! FLOAT_TYPE_P (type))
7674 if (! wins && integer_zerop (arg0))
7675 return negate_expr (fold_convert (type, arg1));
7676 if (integer_zerop (arg1))
7677 return non_lvalue (fold_convert (type, arg0));
7679 /* Fold A - (A & B) into ~B & A. */
7680 if (!TREE_SIDE_EFFECTS (arg0)
7681 && TREE_CODE (arg1) == BIT_AND_EXPR)
7683 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
7684 return fold (build2 (BIT_AND_EXPR, type,
7685 fold (build1 (BIT_NOT_EXPR, type,
7686 TREE_OPERAND (arg1, 0))),
7688 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
7689 return fold (build2 (BIT_AND_EXPR, type,
7690 fold (build1 (BIT_NOT_EXPR, type,
7691 TREE_OPERAND (arg1, 1))),
7695 /* Fold (A & ~B) - (A & B) into (A ^ B) - B, where B is
7696 any power of 2 minus 1. */
7697 if (TREE_CODE (arg0) == BIT_AND_EXPR
7698 && TREE_CODE (arg1) == BIT_AND_EXPR
7699 && operand_equal_p (TREE_OPERAND (arg0, 0),
7700 TREE_OPERAND (arg1, 0), 0))
7702 tree mask0 = TREE_OPERAND (arg0, 1);
7703 tree mask1 = TREE_OPERAND (arg1, 1);
7704 tree tem = fold (build1 (BIT_NOT_EXPR, type, mask0));
7706 if (operand_equal_p (tem, mask1, 0))
7708 tem = fold (build2 (BIT_XOR_EXPR, type,
7709 TREE_OPERAND (arg0, 0), mask1));
7710 return fold (build2 (MINUS_EXPR, type, tem, mask1));
7715 /* See if ARG1 is zero and X - ARG1 reduces to X. */
7716 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
7717 return non_lvalue (fold_convert (type, arg0));
7719 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
7720 ARG0 is zero and X + ARG0 reduces to X, since that would mean
7721 (-ARG1 + ARG0) reduces to -ARG1. */
7722 else if (!wins && fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
7723 return negate_expr (fold_convert (type, arg1));
7725 /* Fold &x - &x. This can happen from &x.foo - &x.
7726 This is unsafe for certain floats even in non-IEEE formats.
7727 In IEEE, it is unsafe because it does wrong for NaNs.
7728 Also note that operand_equal_p is always false if an operand
7731 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
7732 && operand_equal_p (arg0, arg1, 0))
7733 return fold_convert (type, integer_zero_node);
7735 /* A - B -> A + (-B) if B is easily negatable. */
7736 if (!wins && negate_expr_p (arg1)
7737 && ((FLOAT_TYPE_P (type)
7738 /* Avoid this transformation if B is a positive REAL_CST. */
7739 && (TREE_CODE (arg1) != REAL_CST
7740 || REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1))))
7741 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv)))
7742 return fold (build2 (PLUS_EXPR, type, arg0, negate_expr (arg1)));
7744 /* Try folding difference of addresses. */
7748 if ((TREE_CODE (arg0) == ADDR_EXPR
7749 || TREE_CODE (arg1) == ADDR_EXPR)
7750 && ptr_difference_const (arg0, arg1, &diff))
7751 return build_int_cst_type (type, diff);
7754 /* Try replacing &a[i1] - c * i2 with &a[i1 - i2], if c is step
7755 of the array. Loop optimizer sometimes produce this type of
7757 if (TREE_CODE (arg0) == ADDR_EXPR
7758 && TREE_CODE (arg1) == MULT_EXPR)
7760 tem = try_move_mult_to_index (MINUS_EXPR, arg0, arg1);
7762 return fold_convert (type, fold (tem));
7765 if (TREE_CODE (arg0) == MULT_EXPR
7766 && TREE_CODE (arg1) == MULT_EXPR
7767 && (!FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
7769 /* (A * C) - (B * C) -> (A-B) * C. */
7770 if (operand_equal_p (TREE_OPERAND (arg0, 1),
7771 TREE_OPERAND (arg1, 1), 0))
7772 return fold (build2 (MULT_EXPR, type,
7773 fold (build2 (MINUS_EXPR, type,
7774 TREE_OPERAND (arg0, 0),
7775 TREE_OPERAND (arg1, 0))),
7776 TREE_OPERAND (arg0, 1)));
7777 /* (A * C1) - (A * C2) -> A * (C1-C2). */
7778 if (operand_equal_p (TREE_OPERAND (arg0, 0),
7779 TREE_OPERAND (arg1, 0), 0))
7780 return fold (build2 (MULT_EXPR, type,
7781 TREE_OPERAND (arg0, 0),
7782 fold (build2 (MINUS_EXPR, type,
7783 TREE_OPERAND (arg0, 1),
7784 TREE_OPERAND (arg1, 1)))));
7790 /* (-A) * (-B) -> A * B */
7791 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
7792 return fold (build2 (MULT_EXPR, type,
7793 TREE_OPERAND (arg0, 0),
7794 negate_expr (arg1)));
7795 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
7796 return fold (build2 (MULT_EXPR, type,
7798 TREE_OPERAND (arg1, 0)));
7800 if (TREE_CODE (type) == COMPLEX_TYPE)
7802 tem = fold_complex_mult (type, arg0, arg1);
7807 if (! FLOAT_TYPE_P (type))
7809 if (integer_zerop (arg1))
7810 return omit_one_operand (type, arg1, arg0);
7811 if (integer_onep (arg1))
7812 return non_lvalue (fold_convert (type, arg0));
7814 /* (a * (1 << b)) is (a << b) */
7815 if (TREE_CODE (arg1) == LSHIFT_EXPR
7816 && integer_onep (TREE_OPERAND (arg1, 0)))
7817 return fold (build2 (LSHIFT_EXPR, type, arg0,
7818 TREE_OPERAND (arg1, 1)));
7819 if (TREE_CODE (arg0) == LSHIFT_EXPR
7820 && integer_onep (TREE_OPERAND (arg0, 0)))
7821 return fold (build2 (LSHIFT_EXPR, type, arg1,
7822 TREE_OPERAND (arg0, 1)));
7824 if (TREE_CODE (arg1) == INTEGER_CST
7825 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0),
7826 fold_convert (type, arg1),
7828 return fold_convert (type, tem);
7833 /* Maybe fold x * 0 to 0. The expressions aren't the same
7834 when x is NaN, since x * 0 is also NaN. Nor are they the
7835 same in modes with signed zeros, since multiplying a
7836 negative value by 0 gives -0, not +0. */
7837 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
7838 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
7839 && real_zerop (arg1))
7840 return omit_one_operand (type, arg1, arg0);
7841 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
7842 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
7843 && real_onep (arg1))
7844 return non_lvalue (fold_convert (type, arg0));
7846 /* Transform x * -1.0 into -x. */
7847 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
7848 && real_minus_onep (arg1))
7849 return fold_convert (type, negate_expr (arg0));
7851 /* Convert (C1/X)*C2 into (C1*C2)/X. */
7852 if (flag_unsafe_math_optimizations
7853 && TREE_CODE (arg0) == RDIV_EXPR
7854 && TREE_CODE (arg1) == REAL_CST
7855 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST)
7857 tree tem = const_binop (MULT_EXPR, TREE_OPERAND (arg0, 0),
7860 return fold (build2 (RDIV_EXPR, type, tem,
7861 TREE_OPERAND (arg0, 1)));
7864 /* Strip sign operations from X in X*X, i.e. -Y*-Y -> Y*Y. */
7865 if (operand_equal_p (arg0, arg1, 0))
7867 tree tem = fold_strip_sign_ops (arg0);
7868 if (tem != NULL_TREE)
7870 tem = fold_convert (type, tem);
7871 return fold (build2 (MULT_EXPR, type, tem, tem));
7875 if (flag_unsafe_math_optimizations)
7877 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
7878 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
7880 /* Optimizations of root(...)*root(...). */
7881 if (fcode0 == fcode1 && BUILTIN_ROOT_P (fcode0))
7883 tree rootfn, arg, arglist;
7884 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
7885 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
7887 /* Optimize sqrt(x)*sqrt(x) as x. */
7888 if (BUILTIN_SQRT_P (fcode0)
7889 && operand_equal_p (arg00, arg10, 0)
7890 && ! HONOR_SNANS (TYPE_MODE (type)))
7893 /* Optimize root(x)*root(y) as root(x*y). */
7894 rootfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7895 arg = fold (build2 (MULT_EXPR, type, arg00, arg10));
7896 arglist = build_tree_list (NULL_TREE, arg);
7897 return build_function_call_expr (rootfn, arglist);
7900 /* Optimize expN(x)*expN(y) as expN(x+y). */
7901 if (fcode0 == fcode1 && BUILTIN_EXPONENT_P (fcode0))
7903 tree expfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7904 tree arg = build2 (PLUS_EXPR, type,
7905 TREE_VALUE (TREE_OPERAND (arg0, 1)),
7906 TREE_VALUE (TREE_OPERAND (arg1, 1)));
7907 tree arglist = build_tree_list (NULL_TREE, fold (arg));
7908 return build_function_call_expr (expfn, arglist);
7911 /* Optimizations of pow(...)*pow(...). */
7912 if ((fcode0 == BUILT_IN_POW && fcode1 == BUILT_IN_POW)
7913 || (fcode0 == BUILT_IN_POWF && fcode1 == BUILT_IN_POWF)
7914 || (fcode0 == BUILT_IN_POWL && fcode1 == BUILT_IN_POWL))
7916 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
7917 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
7919 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
7920 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
7923 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
7924 if (operand_equal_p (arg01, arg11, 0))
7926 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7927 tree arg = build2 (MULT_EXPR, type, arg00, arg10);
7928 tree arglist = tree_cons (NULL_TREE, fold (arg),
7929 build_tree_list (NULL_TREE,
7931 return build_function_call_expr (powfn, arglist);
7934 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
7935 if (operand_equal_p (arg00, arg10, 0))
7937 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7938 tree arg = fold (build2 (PLUS_EXPR, type, arg01, arg11));
7939 tree arglist = tree_cons (NULL_TREE, arg00,
7940 build_tree_list (NULL_TREE,
7942 return build_function_call_expr (powfn, arglist);
7946 /* Optimize tan(x)*cos(x) as sin(x). */
7947 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_COS)
7948 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_COSF)
7949 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_COSL)
7950 || (fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_TAN)
7951 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_TANF)
7952 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_TANL))
7953 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
7954 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
7956 tree sinfn = mathfn_built_in (type, BUILT_IN_SIN);
7958 if (sinfn != NULL_TREE)
7959 return build_function_call_expr (sinfn,
7960 TREE_OPERAND (arg0, 1));
7963 /* Optimize x*pow(x,c) as pow(x,c+1). */
7964 if (fcode1 == BUILT_IN_POW
7965 || fcode1 == BUILT_IN_POWF
7966 || fcode1 == BUILT_IN_POWL)
7968 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
7969 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
7971 if (TREE_CODE (arg11) == REAL_CST
7972 && ! TREE_CONSTANT_OVERFLOW (arg11)
7973 && operand_equal_p (arg0, arg10, 0))
7975 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
7979 c = TREE_REAL_CST (arg11);
7980 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
7981 arg = build_real (type, c);
7982 arglist = build_tree_list (NULL_TREE, arg);
7983 arglist = tree_cons (NULL_TREE, arg0, arglist);
7984 return build_function_call_expr (powfn, arglist);
7988 /* Optimize pow(x,c)*x as pow(x,c+1). */
7989 if (fcode0 == BUILT_IN_POW
7990 || fcode0 == BUILT_IN_POWF
7991 || fcode0 == BUILT_IN_POWL)
7993 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
7994 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
7996 if (TREE_CODE (arg01) == REAL_CST
7997 && ! TREE_CONSTANT_OVERFLOW (arg01)
7998 && operand_equal_p (arg1, arg00, 0))
8000 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
8004 c = TREE_REAL_CST (arg01);
8005 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
8006 arg = build_real (type, c);
8007 arglist = build_tree_list (NULL_TREE, arg);
8008 arglist = tree_cons (NULL_TREE, arg1, arglist);
8009 return build_function_call_expr (powfn, arglist);
8013 /* Optimize x*x as pow(x,2.0), which is expanded as x*x. */
8015 && operand_equal_p (arg0, arg1, 0))
8017 tree powfn = mathfn_built_in (type, BUILT_IN_POW);
8021 tree arg = build_real (type, dconst2);
8022 tree arglist = build_tree_list (NULL_TREE, arg);
8023 arglist = tree_cons (NULL_TREE, arg0, arglist);
8024 return build_function_call_expr (powfn, arglist);
8033 if (integer_all_onesp (arg1))
8034 return omit_one_operand (type, arg1, arg0);
8035 if (integer_zerop (arg1))
8036 return non_lvalue (fold_convert (type, arg0));
8037 if (operand_equal_p (arg0, arg1, 0))
8038 return non_lvalue (fold_convert (type, arg0));
8041 if (TREE_CODE (arg0) == BIT_NOT_EXPR
8042 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
8044 t1 = build_int_cst (type, -1);
8045 t1 = force_fit_type (t1, 0, false, false);
8046 return omit_one_operand (type, t1, arg1);
8050 if (TREE_CODE (arg1) == BIT_NOT_EXPR
8051 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
8053 t1 = build_int_cst (type, -1);
8054 t1 = force_fit_type (t1, 0, false, false);
8055 return omit_one_operand (type, t1, arg0);
8058 t1 = distribute_bit_expr (code, type, arg0, arg1);
8059 if (t1 != NULL_TREE)
8062 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
8064 This results in more efficient code for machines without a NAND
8065 instruction. Combine will canonicalize to the first form
8066 which will allow use of NAND instructions provided by the
8067 backend if they exist. */
8068 if (TREE_CODE (arg0) == BIT_NOT_EXPR
8069 && TREE_CODE (arg1) == BIT_NOT_EXPR)
8071 return fold (build1 (BIT_NOT_EXPR, type,
8072 build2 (BIT_AND_EXPR, type,
8073 TREE_OPERAND (arg0, 0),
8074 TREE_OPERAND (arg1, 0))));
8077 /* See if this can be simplified into a rotate first. If that
8078 is unsuccessful continue in the association code. */
8082 if (integer_zerop (arg1))
8083 return non_lvalue (fold_convert (type, arg0));
8084 if (integer_all_onesp (arg1))
8085 return fold (build1 (BIT_NOT_EXPR, type, arg0));
8086 if (operand_equal_p (arg0, arg1, 0))
8087 return omit_one_operand (type, integer_zero_node, arg0);
8090 if (TREE_CODE (arg0) == BIT_NOT_EXPR
8091 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
8093 t1 = build_int_cst (type, -1);
8094 t1 = force_fit_type (t1, 0, false, false);
8095 return omit_one_operand (type, t1, arg1);
8099 if (TREE_CODE (arg1) == BIT_NOT_EXPR
8100 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
8102 t1 = build_int_cst (type, -1);
8103 t1 = force_fit_type (t1, 0, false, false);
8104 return omit_one_operand (type, t1, arg0);
8107 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
8108 with a constant, and the two constants have no bits in common,
8109 we should treat this as a BIT_IOR_EXPR since this may produce more
8111 if (TREE_CODE (arg0) == BIT_AND_EXPR
8112 && TREE_CODE (arg1) == BIT_AND_EXPR
8113 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8114 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
8115 && integer_zerop (const_binop (BIT_AND_EXPR,
8116 TREE_OPERAND (arg0, 1),
8117 TREE_OPERAND (arg1, 1), 0)))
8119 code = BIT_IOR_EXPR;
8123 /* See if this can be simplified into a rotate first. If that
8124 is unsuccessful continue in the association code. */
8128 if (integer_all_onesp (arg1))
8129 return non_lvalue (fold_convert (type, arg0));
8130 if (integer_zerop (arg1))
8131 return omit_one_operand (type, arg1, arg0);
8132 if (operand_equal_p (arg0, arg1, 0))
8133 return non_lvalue (fold_convert (type, arg0));
8135 /* ~X & X is always zero. */
8136 if (TREE_CODE (arg0) == BIT_NOT_EXPR
8137 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
8138 return omit_one_operand (type, integer_zero_node, arg1);
8140 /* X & ~X is always zero. */
8141 if (TREE_CODE (arg1) == BIT_NOT_EXPR
8142 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
8143 return omit_one_operand (type, integer_zero_node, arg0);
8145 t1 = distribute_bit_expr (code, type, arg0, arg1);
8146 if (t1 != NULL_TREE)
8148 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
8149 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
8150 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
8153 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
8155 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
8156 && (~TREE_INT_CST_LOW (arg1)
8157 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
8158 return fold_convert (type, TREE_OPERAND (arg0, 0));
8161 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
8163 This results in more efficient code for machines without a NOR
8164 instruction. Combine will canonicalize to the first form
8165 which will allow use of NOR instructions provided by the
8166 backend if they exist. */
8167 if (TREE_CODE (arg0) == BIT_NOT_EXPR
8168 && TREE_CODE (arg1) == BIT_NOT_EXPR)
8170 return fold (build1 (BIT_NOT_EXPR, type,
8171 build2 (BIT_IOR_EXPR, type,
8172 TREE_OPERAND (arg0, 0),
8173 TREE_OPERAND (arg1, 0))));
8179 /* Don't touch a floating-point divide by zero unless the mode
8180 of the constant can represent infinity. */
8181 if (TREE_CODE (arg1) == REAL_CST
8182 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
8183 && real_zerop (arg1))
8186 /* (-A) / (-B) -> A / B */
8187 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
8188 return fold (build2 (RDIV_EXPR, type,
8189 TREE_OPERAND (arg0, 0),
8190 negate_expr (arg1)));
8191 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
8192 return fold (build2 (RDIV_EXPR, type,
8194 TREE_OPERAND (arg1, 0)));
8196 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
8197 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
8198 && real_onep (arg1))
8199 return non_lvalue (fold_convert (type, arg0));
8201 /* In IEEE floating point, x/-1 is not equivalent to -x for snans. */
8202 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
8203 && real_minus_onep (arg1))
8204 return non_lvalue (fold_convert (type, negate_expr (arg0)));
8206 /* If ARG1 is a constant, we can convert this to a multiply by the
8207 reciprocal. This does not have the same rounding properties,
8208 so only do this if -funsafe-math-optimizations. We can actually
8209 always safely do it if ARG1 is a power of two, but it's hard to
8210 tell if it is or not in a portable manner. */
8211 if (TREE_CODE (arg1) == REAL_CST)
8213 if (flag_unsafe_math_optimizations
8214 && 0 != (tem = const_binop (code, build_real (type, dconst1),
8216 return fold (build2 (MULT_EXPR, type, arg0, tem));
8217 /* Find the reciprocal if optimizing and the result is exact. */
8221 r = TREE_REAL_CST (arg1);
8222 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
8224 tem = build_real (type, r);
8225 return fold (build2 (MULT_EXPR, type, arg0, tem));
8229 /* Convert A/B/C to A/(B*C). */
8230 if (flag_unsafe_math_optimizations
8231 && TREE_CODE (arg0) == RDIV_EXPR)
8232 return fold (build2 (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
8233 fold (build2 (MULT_EXPR, type,
8234 TREE_OPERAND (arg0, 1), arg1))));
8236 /* Convert A/(B/C) to (A/B)*C. */
8237 if (flag_unsafe_math_optimizations
8238 && TREE_CODE (arg1) == RDIV_EXPR)
8239 return fold (build2 (MULT_EXPR, type,
8240 fold (build2 (RDIV_EXPR, type, arg0,
8241 TREE_OPERAND (arg1, 0))),
8242 TREE_OPERAND (arg1, 1)));
8244 /* Convert C1/(X*C2) into (C1/C2)/X. */
8245 if (flag_unsafe_math_optimizations
8246 && TREE_CODE (arg1) == MULT_EXPR
8247 && TREE_CODE (arg0) == REAL_CST
8248 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
8250 tree tem = const_binop (RDIV_EXPR, arg0,
8251 TREE_OPERAND (arg1, 1), 0);
8253 return fold (build2 (RDIV_EXPR, type, tem,
8254 TREE_OPERAND (arg1, 0)));
8257 if (TREE_CODE (type) == COMPLEX_TYPE)
8259 tem = fold_complex_div (type, arg0, arg1, code);
8264 if (flag_unsafe_math_optimizations)
8266 enum built_in_function fcode = builtin_mathfn_code (arg1);
8267 /* Optimize x/expN(y) into x*expN(-y). */
8268 if (BUILTIN_EXPONENT_P (fcode))
8270 tree expfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
8271 tree arg = negate_expr (TREE_VALUE (TREE_OPERAND (arg1, 1)));
8272 tree arglist = build_tree_list (NULL_TREE,
8273 fold_convert (type, arg));
8274 arg1 = build_function_call_expr (expfn, arglist);
8275 return fold (build2 (MULT_EXPR, type, arg0, arg1));
8278 /* Optimize x/pow(y,z) into x*pow(y,-z). */
8279 if (fcode == BUILT_IN_POW
8280 || fcode == BUILT_IN_POWF
8281 || fcode == BUILT_IN_POWL)
8283 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
8284 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
8285 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1, 1)));
8286 tree neg11 = fold_convert (type, negate_expr (arg11));
8287 tree arglist = tree_cons(NULL_TREE, arg10,
8288 build_tree_list (NULL_TREE, neg11));
8289 arg1 = build_function_call_expr (powfn, arglist);
8290 return fold (build2 (MULT_EXPR, type, arg0, arg1));
8294 if (flag_unsafe_math_optimizations)
8296 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
8297 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
8299 /* Optimize sin(x)/cos(x) as tan(x). */
8300 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_COS)
8301 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_COSF)
8302 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_COSL))
8303 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
8304 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
8306 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
8308 if (tanfn != NULL_TREE)
8309 return build_function_call_expr (tanfn,
8310 TREE_OPERAND (arg0, 1));
8313 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
8314 if (((fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_SIN)
8315 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_SINF)
8316 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_SINL))
8317 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
8318 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
8320 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
8322 if (tanfn != NULL_TREE)
8324 tree tmp = TREE_OPERAND (arg0, 1);
8325 tmp = build_function_call_expr (tanfn, tmp);
8326 return fold (build2 (RDIV_EXPR, type,
8327 build_real (type, dconst1), tmp));
8331 /* Optimize pow(x,c)/x as pow(x,c-1). */
8332 if (fcode0 == BUILT_IN_POW
8333 || fcode0 == BUILT_IN_POWF
8334 || fcode0 == BUILT_IN_POWL)
8336 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
8337 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0, 1)));
8338 if (TREE_CODE (arg01) == REAL_CST
8339 && ! TREE_CONSTANT_OVERFLOW (arg01)
8340 && operand_equal_p (arg1, arg00, 0))
8342 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
8346 c = TREE_REAL_CST (arg01);
8347 real_arithmetic (&c, MINUS_EXPR, &c, &dconst1);
8348 arg = build_real (type, c);
8349 arglist = build_tree_list (NULL_TREE, arg);
8350 arglist = tree_cons (NULL_TREE, arg1, arglist);
8351 return build_function_call_expr (powfn, arglist);
8357 case TRUNC_DIV_EXPR:
8358 case ROUND_DIV_EXPR:
8359 case FLOOR_DIV_EXPR:
8361 case EXACT_DIV_EXPR:
8362 if (integer_onep (arg1))
8363 return non_lvalue (fold_convert (type, arg0));
8364 if (integer_zerop (arg1))
8367 if (!TYPE_UNSIGNED (type)
8368 && TREE_CODE (arg1) == INTEGER_CST
8369 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
8370 && TREE_INT_CST_HIGH (arg1) == -1)
8371 return fold_convert (type, negate_expr (arg0));
8373 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
8374 operation, EXACT_DIV_EXPR.
8376 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
8377 At one time others generated faster code, it's not clear if they do
8378 after the last round to changes to the DIV code in expmed.c. */
8379 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
8380 && multiple_of_p (type, arg0, arg1))
8381 return fold (build2 (EXACT_DIV_EXPR, type, arg0, arg1));
8383 if (TREE_CODE (arg1) == INTEGER_CST
8384 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
8386 return fold_convert (type, tem);
8388 if (TREE_CODE (type) == COMPLEX_TYPE)
8390 tem = fold_complex_div (type, arg0, arg1, code);
8397 case FLOOR_MOD_EXPR:
8398 case ROUND_MOD_EXPR:
8399 case TRUNC_MOD_EXPR:
8400 /* X % 1 is always zero, but be sure to preserve any side
8402 if (integer_onep (arg1))
8403 return omit_one_operand (type, integer_zero_node, arg0);
8405 /* X % 0, return X % 0 unchanged so that we can get the
8406 proper warnings and errors. */
8407 if (integer_zerop (arg1))
8410 /* 0 % X is always zero, but be sure to preserve any side
8411 effects in X. Place this after checking for X == 0. */
8412 if (integer_zerop (arg0))
8413 return omit_one_operand (type, integer_zero_node, arg1);
8415 /* X % -1 is zero. */
8416 if (!TYPE_UNSIGNED (type)
8417 && TREE_CODE (arg1) == INTEGER_CST
8418 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
8419 && TREE_INT_CST_HIGH (arg1) == -1)
8420 return omit_one_operand (type, integer_zero_node, arg0);
8422 /* Optimize unsigned TRUNC_MOD_EXPR by a power of two into a
8423 BIT_AND_EXPR, i.e. "X % C" into "X & C2". */
8424 if (code == TRUNC_MOD_EXPR
8425 && TYPE_UNSIGNED (type)
8426 && integer_pow2p (arg1))
8428 unsigned HOST_WIDE_INT high, low;
8432 l = tree_log2 (arg1);
8433 if (l >= HOST_BITS_PER_WIDE_INT)
8435 high = ((unsigned HOST_WIDE_INT) 1
8436 << (l - HOST_BITS_PER_WIDE_INT)) - 1;
8442 low = ((unsigned HOST_WIDE_INT) 1 << l) - 1;
8445 mask = build_int_cst_wide (type, low, high);
8446 return fold (build2 (BIT_AND_EXPR, type,
8447 fold_convert (type, arg0), mask));
8450 /* X % -C is the same as X % C. */
8451 if (code == TRUNC_MOD_EXPR
8452 && !TYPE_UNSIGNED (type)
8453 && TREE_CODE (arg1) == INTEGER_CST
8454 && TREE_INT_CST_HIGH (arg1) < 0
8456 /* Avoid this transformation if C is INT_MIN, i.e. C == -C. */
8457 && !sign_bit_p (arg1, arg1))
8458 return fold (build2 (code, type, fold_convert (type, arg0),
8459 fold_convert (type, negate_expr (arg1))));
8461 /* X % -Y is the same as X % Y. */
8462 if (code == TRUNC_MOD_EXPR
8463 && !TYPE_UNSIGNED (type)
8464 && TREE_CODE (arg1) == NEGATE_EXPR
8466 return fold (build2 (code, type, fold_convert (type, arg0),
8467 fold_convert (type, TREE_OPERAND (arg1, 0))));
8469 if (TREE_CODE (arg1) == INTEGER_CST
8470 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
8472 return fold_convert (type, tem);
8478 if (integer_all_onesp (arg0))
8479 return omit_one_operand (type, arg0, arg1);
8483 /* Optimize -1 >> x for arithmetic right shifts. */
8484 if (integer_all_onesp (arg0) && !TYPE_UNSIGNED (type))
8485 return omit_one_operand (type, arg0, arg1);
8486 /* ... fall through ... */
8490 if (integer_zerop (arg1))
8491 return non_lvalue (fold_convert (type, arg0));
8492 if (integer_zerop (arg0))
8493 return omit_one_operand (type, arg0, arg1);
8495 /* Since negative shift count is not well-defined,
8496 don't try to compute it in the compiler. */
8497 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
8499 /* Rewrite an LROTATE_EXPR by a constant into an
8500 RROTATE_EXPR by a new constant. */
8501 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
8503 tree tem = build_int_cst (NULL_TREE,
8504 GET_MODE_BITSIZE (TYPE_MODE (type)));
8505 tem = fold_convert (TREE_TYPE (arg1), tem);
8506 tem = const_binop (MINUS_EXPR, tem, arg1, 0);
8507 return fold (build2 (RROTATE_EXPR, type, arg0, tem));
8510 /* If we have a rotate of a bit operation with the rotate count and
8511 the second operand of the bit operation both constant,
8512 permute the two operations. */
8513 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
8514 && (TREE_CODE (arg0) == BIT_AND_EXPR
8515 || TREE_CODE (arg0) == BIT_IOR_EXPR
8516 || TREE_CODE (arg0) == BIT_XOR_EXPR)
8517 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8518 return fold (build2 (TREE_CODE (arg0), type,
8519 fold (build2 (code, type,
8520 TREE_OPERAND (arg0, 0), arg1)),
8521 fold (build2 (code, type,
8522 TREE_OPERAND (arg0, 1), arg1))));
8524 /* Two consecutive rotates adding up to the width of the mode can
8526 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
8527 && TREE_CODE (arg0) == RROTATE_EXPR
8528 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8529 && TREE_INT_CST_HIGH (arg1) == 0
8530 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
8531 && ((TREE_INT_CST_LOW (arg1)
8532 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
8533 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type))))
8534 return TREE_OPERAND (arg0, 0);
8539 if (operand_equal_p (arg0, arg1, 0))
8540 return omit_one_operand (type, arg0, arg1);
8541 if (INTEGRAL_TYPE_P (type)
8542 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
8543 return omit_one_operand (type, arg1, arg0);
8547 if (operand_equal_p (arg0, arg1, 0))
8548 return omit_one_operand (type, arg0, arg1);
8549 if (INTEGRAL_TYPE_P (type)
8550 && TYPE_MAX_VALUE (type)
8551 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
8552 return omit_one_operand (type, arg1, arg0);
8555 case TRUTH_ANDIF_EXPR:
8556 /* Note that the operands of this must be ints
8557 and their values must be 0 or 1.
8558 ("true" is a fixed value perhaps depending on the language.) */
8559 /* If first arg is constant zero, return it. */
8560 if (integer_zerop (arg0))
8561 return fold_convert (type, arg0);
8562 case TRUTH_AND_EXPR:
8563 /* If either arg is constant true, drop it. */
8564 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
8565 return non_lvalue (fold_convert (type, arg1));
8566 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
8567 /* Preserve sequence points. */
8568 && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
8569 return non_lvalue (fold_convert (type, arg0));
8570 /* If second arg is constant zero, result is zero, but first arg
8571 must be evaluated. */
8572 if (integer_zerop (arg1))
8573 return omit_one_operand (type, arg1, arg0);
8574 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
8575 case will be handled here. */
8576 if (integer_zerop (arg0))
8577 return omit_one_operand (type, arg0, arg1);
8579 /* !X && X is always false. */
8580 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
8581 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
8582 return omit_one_operand (type, integer_zero_node, arg1);
8583 /* X && !X is always false. */
8584 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
8585 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
8586 return omit_one_operand (type, integer_zero_node, arg0);
8588 /* A < X && A + 1 > Y ==> A < X && A >= Y. Normally A + 1 > Y
8589 means A >= Y && A != MAX, but in this case we know that
8592 if (!TREE_SIDE_EFFECTS (arg0)
8593 && !TREE_SIDE_EFFECTS (arg1))
8595 tem = fold_to_nonsharp_ineq_using_bound (arg0, arg1);
8597 return fold (build2 (code, type, tem, arg1));
8599 tem = fold_to_nonsharp_ineq_using_bound (arg1, arg0);
8601 return fold (build2 (code, type, arg0, tem));
8605 /* We only do these simplifications if we are optimizing. */
8609 /* Check for things like (A || B) && (A || C). We can convert this
8610 to A || (B && C). Note that either operator can be any of the four
8611 truth and/or operations and the transformation will still be
8612 valid. Also note that we only care about order for the
8613 ANDIF and ORIF operators. If B contains side effects, this
8614 might change the truth-value of A. */
8615 if (TREE_CODE (arg0) == TREE_CODE (arg1)
8616 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
8617 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
8618 || TREE_CODE (arg0) == TRUTH_AND_EXPR
8619 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
8620 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
8622 tree a00 = TREE_OPERAND (arg0, 0);
8623 tree a01 = TREE_OPERAND (arg0, 1);
8624 tree a10 = TREE_OPERAND (arg1, 0);
8625 tree a11 = TREE_OPERAND (arg1, 1);
8626 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
8627 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
8628 && (code == TRUTH_AND_EXPR
8629 || code == TRUTH_OR_EXPR));
8631 if (operand_equal_p (a00, a10, 0))
8632 return fold (build2 (TREE_CODE (arg0), type, a00,
8633 fold (build2 (code, type, a01, a11))));
8634 else if (commutative && operand_equal_p (a00, a11, 0))
8635 return fold (build2 (TREE_CODE (arg0), type, a00,
8636 fold (build2 (code, type, a01, a10))));
8637 else if (commutative && operand_equal_p (a01, a10, 0))
8638 return fold (build2 (TREE_CODE (arg0), type, a01,
8639 fold (build2 (code, type, a00, a11))));
8641 /* This case if tricky because we must either have commutative
8642 operators or else A10 must not have side-effects. */
8644 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
8645 && operand_equal_p (a01, a11, 0))
8646 return fold (build2 (TREE_CODE (arg0), type,
8647 fold (build2 (code, type, a00, a10)),
8651 /* See if we can build a range comparison. */
8652 if (0 != (tem = fold_range_test (t)))
8655 /* Check for the possibility of merging component references. If our
8656 lhs is another similar operation, try to merge its rhs with our
8657 rhs. Then try to merge our lhs and rhs. */
8658 if (TREE_CODE (arg0) == code
8659 && 0 != (tem = fold_truthop (code, type,
8660 TREE_OPERAND (arg0, 1), arg1)))
8661 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), tem));
8663 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
8668 case TRUTH_ORIF_EXPR:
8669 /* Note that the operands of this must be ints
8670 and their values must be 0 or true.
8671 ("true" is a fixed value perhaps depending on the language.) */
8672 /* If first arg is constant true, return it. */
8673 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
8674 return fold_convert (type, arg0);
8676 /* If either arg is constant zero, drop it. */
8677 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
8678 return non_lvalue (fold_convert (type, arg1));
8679 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
8680 /* Preserve sequence points. */
8681 && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
8682 return non_lvalue (fold_convert (type, arg0));
8683 /* If second arg is constant true, result is true, but we must
8684 evaluate first arg. */
8685 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
8686 return omit_one_operand (type, arg1, arg0);
8687 /* Likewise for first arg, but note this only occurs here for
8689 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
8690 return omit_one_operand (type, arg0, arg1);
8692 /* !X || X is always true. */
8693 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
8694 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
8695 return omit_one_operand (type, integer_one_node, arg1);
8696 /* X || !X is always true. */
8697 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
8698 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
8699 return omit_one_operand (type, integer_one_node, arg0);
8703 case TRUTH_XOR_EXPR:
8704 /* If the second arg is constant zero, drop it. */
8705 if (integer_zerop (arg1))
8706 return non_lvalue (fold_convert (type, arg0));
8707 /* If the second arg is constant true, this is a logical inversion. */
8708 if (integer_onep (arg1))
8709 return non_lvalue (fold_convert (type, invert_truthvalue (arg0)));
8710 /* Identical arguments cancel to zero. */
8711 if (operand_equal_p (arg0, arg1, 0))
8712 return omit_one_operand (type, integer_zero_node, arg0);
8714 /* !X ^ X is always true. */
8715 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
8716 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
8717 return omit_one_operand (type, integer_one_node, arg1);
8719 /* X ^ !X is always true. */
8720 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
8721 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
8722 return omit_one_operand (type, integer_one_node, arg0);
8732 /* If one arg is a real or integer constant, put it last. */
8733 if (tree_swap_operands_p (arg0, arg1, true))
8734 return fold (build2 (swap_tree_comparison (code), type, arg1, arg0));
8736 /* If this is an equality comparison of the address of a non-weak
8737 object against zero, then we know the result. */
8738 if ((code == EQ_EXPR || code == NE_EXPR)
8739 && TREE_CODE (arg0) == ADDR_EXPR
8740 && DECL_P (TREE_OPERAND (arg0, 0))
8741 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
8742 && integer_zerop (arg1))
8743 return constant_boolean_node (code != EQ_EXPR, type);
8745 /* If this is an equality comparison of the address of two non-weak,
8746 unaliased symbols neither of which are extern (since we do not
8747 have access to attributes for externs), then we know the result. */
8748 if ((code == EQ_EXPR || code == NE_EXPR)
8749 && TREE_CODE (arg0) == ADDR_EXPR
8750 && DECL_P (TREE_OPERAND (arg0, 0))
8751 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
8752 && ! lookup_attribute ("alias",
8753 DECL_ATTRIBUTES (TREE_OPERAND (arg0, 0)))
8754 && ! DECL_EXTERNAL (TREE_OPERAND (arg0, 0))
8755 && TREE_CODE (arg1) == ADDR_EXPR
8756 && DECL_P (TREE_OPERAND (arg1, 0))
8757 && ! DECL_WEAK (TREE_OPERAND (arg1, 0))
8758 && ! lookup_attribute ("alias",
8759 DECL_ATTRIBUTES (TREE_OPERAND (arg1, 0)))
8760 && ! DECL_EXTERNAL (TREE_OPERAND (arg1, 0)))
8761 return constant_boolean_node (operand_equal_p (arg0, arg1, 0)
8762 ? code == EQ_EXPR : code != EQ_EXPR,
8765 /* If this is a comparison of two exprs that look like an
8766 ARRAY_REF of the same object, then we can fold this to a
8767 comparison of the two offsets. */
8768 if (COMPARISON_CLASS_P (t))
8770 tree base0, offset0, base1, offset1;
8772 if (extract_array_ref (arg0, &base0, &offset0)
8773 && extract_array_ref (arg1, &base1, &offset1)
8774 && operand_equal_p (base0, base1, 0))
8776 if (offset0 == NULL_TREE
8777 && offset1 == NULL_TREE)
8779 offset0 = integer_zero_node;
8780 offset1 = integer_zero_node;
8782 else if (offset0 == NULL_TREE)
8783 offset0 = build_int_cst (TREE_TYPE (offset1), 0);
8784 else if (offset1 == NULL_TREE)
8785 offset1 = build_int_cst (TREE_TYPE (offset0), 0);
8787 if (TREE_TYPE (offset0) == TREE_TYPE (offset1))
8788 return fold (build2 (code, type, offset0, offset1));
8792 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
8794 tree targ0 = strip_float_extensions (arg0);
8795 tree targ1 = strip_float_extensions (arg1);
8796 tree newtype = TREE_TYPE (targ0);
8798 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
8799 newtype = TREE_TYPE (targ1);
8801 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
8802 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
8803 return fold (build2 (code, type, fold_convert (newtype, targ0),
8804 fold_convert (newtype, targ1)));
8806 /* (-a) CMP (-b) -> b CMP a */
8807 if (TREE_CODE (arg0) == NEGATE_EXPR
8808 && TREE_CODE (arg1) == NEGATE_EXPR)
8809 return fold (build2 (code, type, TREE_OPERAND (arg1, 0),
8810 TREE_OPERAND (arg0, 0)));
8812 if (TREE_CODE (arg1) == REAL_CST)
8814 REAL_VALUE_TYPE cst;
8815 cst = TREE_REAL_CST (arg1);
8817 /* (-a) CMP CST -> a swap(CMP) (-CST) */
8818 if (TREE_CODE (arg0) == NEGATE_EXPR)
8820 fold (build2 (swap_tree_comparison (code), type,
8821 TREE_OPERAND (arg0, 0),
8822 build_real (TREE_TYPE (arg1),
8823 REAL_VALUE_NEGATE (cst))));
8825 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
8826 /* a CMP (-0) -> a CMP 0 */
8827 if (REAL_VALUE_MINUS_ZERO (cst))
8828 return fold (build2 (code, type, arg0,
8829 build_real (TREE_TYPE (arg1), dconst0)));
8831 /* x != NaN is always true, other ops are always false. */
8832 if (REAL_VALUE_ISNAN (cst)
8833 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))))
8835 tem = (code == NE_EXPR) ? integer_one_node : integer_zero_node;
8836 return omit_one_operand (type, tem, arg0);
8839 /* Fold comparisons against infinity. */
8840 if (REAL_VALUE_ISINF (cst))
8842 tem = fold_inf_compare (code, type, arg0, arg1);
8843 if (tem != NULL_TREE)
8848 /* If this is a comparison of a real constant with a PLUS_EXPR
8849 or a MINUS_EXPR of a real constant, we can convert it into a
8850 comparison with a revised real constant as long as no overflow
8851 occurs when unsafe_math_optimizations are enabled. */
8852 if (flag_unsafe_math_optimizations
8853 && TREE_CODE (arg1) == REAL_CST
8854 && (TREE_CODE (arg0) == PLUS_EXPR
8855 || TREE_CODE (arg0) == MINUS_EXPR)
8856 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
8857 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
8858 ? MINUS_EXPR : PLUS_EXPR,
8859 arg1, TREE_OPERAND (arg0, 1), 0))
8860 && ! TREE_CONSTANT_OVERFLOW (tem))
8861 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), tem));
8863 /* Likewise, we can simplify a comparison of a real constant with
8864 a MINUS_EXPR whose first operand is also a real constant, i.e.
8865 (c1 - x) < c2 becomes x > c1-c2. */
8866 if (flag_unsafe_math_optimizations
8867 && TREE_CODE (arg1) == REAL_CST
8868 && TREE_CODE (arg0) == MINUS_EXPR
8869 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST
8870 && 0 != (tem = const_binop (MINUS_EXPR, TREE_OPERAND (arg0, 0),
8872 && ! TREE_CONSTANT_OVERFLOW (tem))
8873 return fold (build2 (swap_tree_comparison (code), type,
8874 TREE_OPERAND (arg0, 1), tem));
8876 /* Fold comparisons against built-in math functions. */
8877 if (TREE_CODE (arg1) == REAL_CST
8878 && flag_unsafe_math_optimizations
8879 && ! flag_errno_math)
8881 enum built_in_function fcode = builtin_mathfn_code (arg0);
8883 if (fcode != END_BUILTINS)
8885 tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
8886 if (tem != NULL_TREE)
8892 /* Convert foo++ == CONST into ++foo == CONST + INCR. */
8893 if (TREE_CONSTANT (arg1)
8894 && (TREE_CODE (arg0) == POSTINCREMENT_EXPR
8895 || TREE_CODE (arg0) == POSTDECREMENT_EXPR)
8896 /* This optimization is invalid for ordered comparisons
8897 if CONST+INCR overflows or if foo+incr might overflow.
8898 This optimization is invalid for floating point due to rounding.
8899 For pointer types we assume overflow doesn't happen. */
8900 && (POINTER_TYPE_P (TREE_TYPE (arg0))
8901 || (INTEGRAL_TYPE_P (TREE_TYPE (arg0))
8902 && (code == EQ_EXPR || code == NE_EXPR))))
8904 tree varop, newconst;
8906 if (TREE_CODE (arg0) == POSTINCREMENT_EXPR)
8908 newconst = fold (build2 (PLUS_EXPR, TREE_TYPE (arg0),
8909 arg1, TREE_OPERAND (arg0, 1)));
8910 varop = build2 (PREINCREMENT_EXPR, TREE_TYPE (arg0),
8911 TREE_OPERAND (arg0, 0),
8912 TREE_OPERAND (arg0, 1));
8916 newconst = fold (build2 (MINUS_EXPR, TREE_TYPE (arg0),
8917 arg1, TREE_OPERAND (arg0, 1)));
8918 varop = build2 (PREDECREMENT_EXPR, TREE_TYPE (arg0),
8919 TREE_OPERAND (arg0, 0),
8920 TREE_OPERAND (arg0, 1));
8924 /* If VAROP is a reference to a bitfield, we must mask
8925 the constant by the width of the field. */
8926 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
8927 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (varop, 0), 1))
8928 && host_integerp (DECL_SIZE (TREE_OPERAND
8929 (TREE_OPERAND (varop, 0), 1)), 1))
8931 tree fielddecl = TREE_OPERAND (TREE_OPERAND (varop, 0), 1);
8932 HOST_WIDE_INT size = tree_low_cst (DECL_SIZE (fielddecl), 1);
8933 tree folded_compare, shift;
8935 /* First check whether the comparison would come out
8936 always the same. If we don't do that we would
8937 change the meaning with the masking. */
8938 folded_compare = fold (build2 (code, type,
8939 TREE_OPERAND (varop, 0), arg1));
8940 if (integer_zerop (folded_compare)
8941 || integer_onep (folded_compare))
8942 return omit_one_operand (type, folded_compare, varop);
8944 shift = build_int_cst (NULL_TREE,
8945 TYPE_PRECISION (TREE_TYPE (varop)) - size);
8946 shift = fold_convert (TREE_TYPE (varop), shift);
8947 newconst = fold (build2 (LSHIFT_EXPR, TREE_TYPE (varop),
8949 newconst = fold (build2 (RSHIFT_EXPR, TREE_TYPE (varop),
8953 return fold (build2 (code, type, varop, newconst));
8956 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
8957 This transformation affects the cases which are handled in later
8958 optimizations involving comparisons with non-negative constants. */
8959 if (TREE_CODE (arg1) == INTEGER_CST
8960 && TREE_CODE (arg0) != INTEGER_CST
8961 && tree_int_cst_sgn (arg1) > 0)
8966 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
8967 return fold (build2 (GT_EXPR, type, arg0, arg1));
8970 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
8971 return fold (build2 (LE_EXPR, type, arg0, arg1));
8978 /* Comparisons with the highest or lowest possible integer of
8979 the specified size will have known values.
8981 This is quite similar to fold_relational_hi_lo, however,
8982 attempts to share the code have been nothing but trouble. */
8984 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1)));
8986 if (TREE_CODE (arg1) == INTEGER_CST
8987 && ! TREE_CONSTANT_OVERFLOW (arg1)
8988 && width <= 2 * HOST_BITS_PER_WIDE_INT
8989 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
8990 || POINTER_TYPE_P (TREE_TYPE (arg1))))
8992 HOST_WIDE_INT signed_max_hi;
8993 unsigned HOST_WIDE_INT signed_max_lo;
8994 unsigned HOST_WIDE_INT max_hi, max_lo, min_hi, min_lo;
8996 if (width <= HOST_BITS_PER_WIDE_INT)
8998 signed_max_lo = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
9003 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
9005 max_lo = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
9011 max_lo = signed_max_lo;
9012 min_lo = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
9018 width -= HOST_BITS_PER_WIDE_INT;
9020 signed_max_hi = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
9025 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
9027 max_hi = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
9032 max_hi = signed_max_hi;
9033 min_hi = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
9037 if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1) == max_hi
9038 && TREE_INT_CST_LOW (arg1) == max_lo)
9042 return omit_one_operand (type, integer_zero_node, arg0);
9045 return fold (build2 (EQ_EXPR, type, arg0, arg1));
9048 return omit_one_operand (type, integer_one_node, arg0);
9051 return fold (build2 (NE_EXPR, type, arg0, arg1));
9053 /* The GE_EXPR and LT_EXPR cases above are not normally
9054 reached because of previous transformations. */
9059 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
9061 && TREE_INT_CST_LOW (arg1) == max_lo - 1)
9065 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
9066 return fold (build2 (EQ_EXPR, type, arg0, arg1));
9068 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
9069 return fold (build2 (NE_EXPR, type, arg0, arg1));
9073 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
9075 && TREE_INT_CST_LOW (arg1) == min_lo)
9079 return omit_one_operand (type, integer_zero_node, arg0);
9082 return fold (build2 (EQ_EXPR, type, arg0, arg1));
9085 return omit_one_operand (type, integer_one_node, arg0);
9088 return fold (build2 (NE_EXPR, type, arg0, arg1));
9093 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
9095 && TREE_INT_CST_LOW (arg1) == min_lo + 1)
9099 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
9100 return fold (build2 (NE_EXPR, type, arg0, arg1));
9102 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
9103 return fold (build2 (EQ_EXPR, type, arg0, arg1));
9108 else if (!in_gimple_form
9109 && TREE_INT_CST_HIGH (arg1) == signed_max_hi
9110 && TREE_INT_CST_LOW (arg1) == signed_max_lo
9111 && TYPE_UNSIGNED (TREE_TYPE (arg1))
9112 /* signed_type does not work on pointer types. */
9113 && INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
9115 /* The following case also applies to X < signed_max+1
9116 and X >= signed_max+1 because previous transformations. */
9117 if (code == LE_EXPR || code == GT_EXPR)
9120 st0 = lang_hooks.types.signed_type (TREE_TYPE (arg0));
9121 st1 = lang_hooks.types.signed_type (TREE_TYPE (arg1));
9123 (build2 (code == LE_EXPR ? GE_EXPR: LT_EXPR,
9124 type, fold_convert (st0, arg0),
9125 fold_convert (st1, integer_zero_node)));
9131 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
9132 a MINUS_EXPR of a constant, we can convert it into a comparison with
9133 a revised constant as long as no overflow occurs. */
9134 if ((code == EQ_EXPR || code == NE_EXPR)
9135 && TREE_CODE (arg1) == INTEGER_CST
9136 && (TREE_CODE (arg0) == PLUS_EXPR
9137 || TREE_CODE (arg0) == MINUS_EXPR)
9138 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
9139 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
9140 ? MINUS_EXPR : PLUS_EXPR,
9141 arg1, TREE_OPERAND (arg0, 1), 0))
9142 && ! TREE_CONSTANT_OVERFLOW (tem))
9143 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), tem));
9145 /* Similarly for a NEGATE_EXPR. */
9146 else if ((code == EQ_EXPR || code == NE_EXPR)
9147 && TREE_CODE (arg0) == NEGATE_EXPR
9148 && TREE_CODE (arg1) == INTEGER_CST
9149 && 0 != (tem = negate_expr (arg1))
9150 && TREE_CODE (tem) == INTEGER_CST
9151 && ! TREE_CONSTANT_OVERFLOW (tem))
9152 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), tem));
9154 /* If we have X - Y == 0, we can convert that to X == Y and similarly
9155 for !=. Don't do this for ordered comparisons due to overflow. */
9156 else if ((code == NE_EXPR || code == EQ_EXPR)
9157 && integer_zerop (arg1) && TREE_CODE (arg0) == MINUS_EXPR)
9158 return fold (build2 (code, type,
9159 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1)));
9161 else if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
9162 && TREE_CODE (arg0) == NOP_EXPR)
9164 /* If we are widening one operand of an integer comparison,
9165 see if the other operand is similarly being widened. Perhaps we
9166 can do the comparison in the narrower type. */
9167 tem = fold_widened_comparison (code, type, arg0, arg1);
9171 /* Or if we are changing signedness. */
9172 tem = fold_sign_changed_comparison (code, type, arg0, arg1);
9177 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
9178 constant, we can simplify it. */
9179 else if (TREE_CODE (arg1) == INTEGER_CST
9180 && (TREE_CODE (arg0) == MIN_EXPR
9181 || TREE_CODE (arg0) == MAX_EXPR)
9182 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
9183 return optimize_minmax_comparison (t);
9185 /* If we are comparing an ABS_EXPR with a constant, we can
9186 convert all the cases into explicit comparisons, but they may
9187 well not be faster than doing the ABS and one comparison.
9188 But ABS (X) <= C is a range comparison, which becomes a subtraction
9189 and a comparison, and is probably faster. */
9190 else if (code == LE_EXPR && TREE_CODE (arg1) == INTEGER_CST
9191 && TREE_CODE (arg0) == ABS_EXPR
9192 && ! TREE_SIDE_EFFECTS (arg0)
9193 && (0 != (tem = negate_expr (arg1)))
9194 && TREE_CODE (tem) == INTEGER_CST
9195 && ! TREE_CONSTANT_OVERFLOW (tem))
9196 return fold (build2 (TRUTH_ANDIF_EXPR, type,
9197 build2 (GE_EXPR, type,
9198 TREE_OPERAND (arg0, 0), tem),
9199 build2 (LE_EXPR, type,
9200 TREE_OPERAND (arg0, 0), arg1)));
9202 /* Convert ABS_EXPR<x> >= 0 to true. */
9203 else if (code == GE_EXPR
9204 && tree_expr_nonnegative_p (arg0)
9205 && (integer_zerop (arg1)
9206 || (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
9207 && real_zerop (arg1))))
9208 return omit_one_operand (type, integer_one_node, arg0);
9210 /* Convert ABS_EXPR<x> < 0 to false. */
9211 else if (code == LT_EXPR
9212 && tree_expr_nonnegative_p (arg0)
9213 && (integer_zerop (arg1) || real_zerop (arg1)))
9214 return omit_one_operand (type, integer_zero_node, arg0);
9216 /* Convert ABS_EXPR<x> == 0 or ABS_EXPR<x> != 0 to x == 0 or x != 0. */
9217 else if ((code == EQ_EXPR || code == NE_EXPR)
9218 && TREE_CODE (arg0) == ABS_EXPR
9219 && (integer_zerop (arg1) || real_zerop (arg1)))
9220 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), arg1));
9222 /* If this is an EQ or NE comparison with zero and ARG0 is
9223 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
9224 two operations, but the latter can be done in one less insn
9225 on machines that have only two-operand insns or on which a
9226 constant cannot be the first operand. */
9227 if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR)
9228 && TREE_CODE (arg0) == BIT_AND_EXPR)
9230 tree arg00 = TREE_OPERAND (arg0, 0);
9231 tree arg01 = TREE_OPERAND (arg0, 1);
9232 if (TREE_CODE (arg00) == LSHIFT_EXPR
9233 && integer_onep (TREE_OPERAND (arg00, 0)))
9235 fold (build2 (code, type,
9236 build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
9237 build2 (RSHIFT_EXPR, TREE_TYPE (arg00),
9238 arg01, TREE_OPERAND (arg00, 1)),
9239 fold_convert (TREE_TYPE (arg0),
9242 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
9243 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
9245 fold (build2 (code, type,
9246 build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
9247 build2 (RSHIFT_EXPR, TREE_TYPE (arg01),
9248 arg00, TREE_OPERAND (arg01, 1)),
9249 fold_convert (TREE_TYPE (arg0),
9254 /* If this is an NE or EQ comparison of zero against the result of a
9255 signed MOD operation whose second operand is a power of 2, make
9256 the MOD operation unsigned since it is simpler and equivalent. */
9257 if ((code == NE_EXPR || code == EQ_EXPR)
9258 && integer_zerop (arg1)
9259 && !TYPE_UNSIGNED (TREE_TYPE (arg0))
9260 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
9261 || TREE_CODE (arg0) == CEIL_MOD_EXPR
9262 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
9263 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
9264 && integer_pow2p (TREE_OPERAND (arg0, 1)))
9266 tree newtype = lang_hooks.types.unsigned_type (TREE_TYPE (arg0));
9267 tree newmod = fold (build2 (TREE_CODE (arg0), newtype,
9268 fold_convert (newtype,
9269 TREE_OPERAND (arg0, 0)),
9270 fold_convert (newtype,
9271 TREE_OPERAND (arg0, 1))));
9273 return fold (build2 (code, type, newmod,
9274 fold_convert (newtype, arg1)));
9277 /* If this is an NE comparison of zero with an AND of one, remove the
9278 comparison since the AND will give the correct value. */
9279 if (code == NE_EXPR && integer_zerop (arg1)
9280 && TREE_CODE (arg0) == BIT_AND_EXPR
9281 && integer_onep (TREE_OPERAND (arg0, 1)))
9282 return fold_convert (type, arg0);
9284 /* If we have (A & C) == C where C is a power of 2, convert this into
9285 (A & C) != 0. Similarly for NE_EXPR. */
9286 if ((code == EQ_EXPR || code == NE_EXPR)
9287 && TREE_CODE (arg0) == BIT_AND_EXPR
9288 && integer_pow2p (TREE_OPERAND (arg0, 1))
9289 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
9290 return fold (build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
9291 arg0, fold_convert (TREE_TYPE (arg0),
9292 integer_zero_node)));
9294 /* If we have (A & C) != 0 or (A & C) == 0 and C is a power of
9295 2, then fold the expression into shifts and logical operations. */
9296 tem = fold_single_bit_test (code, arg0, arg1, type);
9300 /* If we have (A & C) == D where D & ~C != 0, convert this into 0.
9301 Similarly for NE_EXPR. */
9302 if ((code == EQ_EXPR || code == NE_EXPR)
9303 && TREE_CODE (arg0) == BIT_AND_EXPR
9304 && TREE_CODE (arg1) == INTEGER_CST
9305 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
9307 tree notc = fold (build1 (BIT_NOT_EXPR,
9308 TREE_TYPE (TREE_OPERAND (arg0, 1)),
9309 TREE_OPERAND (arg0, 1)));
9310 tree dandnotc = fold (build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
9312 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
9313 if (integer_nonzerop (dandnotc))
9314 return omit_one_operand (type, rslt, arg0);
9317 /* If we have (A | C) == D where C & ~D != 0, convert this into 0.
9318 Similarly for NE_EXPR. */
9319 if ((code == EQ_EXPR || code == NE_EXPR)
9320 && TREE_CODE (arg0) == BIT_IOR_EXPR
9321 && TREE_CODE (arg1) == INTEGER_CST
9322 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
9324 tree notd = fold (build1 (BIT_NOT_EXPR, TREE_TYPE (arg1), arg1));
9325 tree candnotd = fold (build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
9326 TREE_OPERAND (arg0, 1), notd));
9327 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
9328 if (integer_nonzerop (candnotd))
9329 return omit_one_operand (type, rslt, arg0);
9332 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
9333 and similarly for >= into !=. */
9334 if ((code == LT_EXPR || code == GE_EXPR)
9335 && TYPE_UNSIGNED (TREE_TYPE (arg0))
9336 && TREE_CODE (arg1) == LSHIFT_EXPR
9337 && integer_onep (TREE_OPERAND (arg1, 0)))
9338 return build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
9339 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
9340 TREE_OPERAND (arg1, 1)),
9341 fold_convert (TREE_TYPE (arg0), integer_zero_node));
9343 else if ((code == LT_EXPR || code == GE_EXPR)
9344 && TYPE_UNSIGNED (TREE_TYPE (arg0))
9345 && (TREE_CODE (arg1) == NOP_EXPR
9346 || TREE_CODE (arg1) == CONVERT_EXPR)
9347 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
9348 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
9350 build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
9351 fold_convert (TREE_TYPE (arg0),
9352 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
9353 TREE_OPERAND (TREE_OPERAND (arg1, 0),
9355 fold_convert (TREE_TYPE (arg0), integer_zero_node));
9357 /* Simplify comparison of something with itself. (For IEEE
9358 floating-point, we can only do some of these simplifications.) */
9359 if (operand_equal_p (arg0, arg1, 0))
9364 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
9365 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
9366 return constant_boolean_node (1, type);
9371 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
9372 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
9373 return constant_boolean_node (1, type);
9374 return fold (build2 (EQ_EXPR, type, arg0, arg1));
9377 /* For NE, we can only do this simplification if integer
9378 or we don't honor IEEE floating point NaNs. */
9379 if (FLOAT_TYPE_P (TREE_TYPE (arg0))
9380 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
9382 /* ... fall through ... */
9385 return constant_boolean_node (0, type);
9391 /* If we are comparing an expression that just has comparisons
9392 of two integer values, arithmetic expressions of those comparisons,
9393 and constants, we can simplify it. There are only three cases
9394 to check: the two values can either be equal, the first can be
9395 greater, or the second can be greater. Fold the expression for
9396 those three values. Since each value must be 0 or 1, we have
9397 eight possibilities, each of which corresponds to the constant 0
9398 or 1 or one of the six possible comparisons.
9400 This handles common cases like (a > b) == 0 but also handles
9401 expressions like ((x > y) - (y > x)) > 0, which supposedly
9402 occur in macroized code. */
9404 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
9406 tree cval1 = 0, cval2 = 0;
9409 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
9410 /* Don't handle degenerate cases here; they should already
9411 have been handled anyway. */
9412 && cval1 != 0 && cval2 != 0
9413 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
9414 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
9415 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
9416 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
9417 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
9418 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
9419 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
9421 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
9422 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
9424 /* We can't just pass T to eval_subst in case cval1 or cval2
9425 was the same as ARG1. */
9428 = fold (build2 (code, type,
9429 eval_subst (arg0, cval1, maxval,
9433 = fold (build2 (code, type,
9434 eval_subst (arg0, cval1, maxval,
9438 = fold (build2 (code, type,
9439 eval_subst (arg0, cval1, minval,
9443 /* All three of these results should be 0 or 1. Confirm they
9444 are. Then use those values to select the proper code
9447 if ((integer_zerop (high_result)
9448 || integer_onep (high_result))
9449 && (integer_zerop (equal_result)
9450 || integer_onep (equal_result))
9451 && (integer_zerop (low_result)
9452 || integer_onep (low_result)))
9454 /* Make a 3-bit mask with the high-order bit being the
9455 value for `>', the next for '=', and the low for '<'. */
9456 switch ((integer_onep (high_result) * 4)
9457 + (integer_onep (equal_result) * 2)
9458 + integer_onep (low_result))
9462 return omit_one_operand (type, integer_zero_node, arg0);
9483 return omit_one_operand (type, integer_one_node, arg0);
9486 tem = build2 (code, type, cval1, cval2);
9488 return save_expr (tem);
9495 /* If this is a comparison of a field, we may be able to simplify it. */
9496 if (((TREE_CODE (arg0) == COMPONENT_REF
9497 && lang_hooks.can_use_bit_fields_p ())
9498 || TREE_CODE (arg0) == BIT_FIELD_REF)
9499 && (code == EQ_EXPR || code == NE_EXPR)
9500 /* Handle the constant case even without -O
9501 to make sure the warnings are given. */
9502 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
9504 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
9509 /* If this is a comparison of complex values and either or both sides
9510 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
9511 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
9512 This may prevent needless evaluations. */
9513 if ((code == EQ_EXPR || code == NE_EXPR)
9514 && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
9515 && (TREE_CODE (arg0) == COMPLEX_EXPR
9516 || TREE_CODE (arg1) == COMPLEX_EXPR
9517 || TREE_CODE (arg0) == COMPLEX_CST
9518 || TREE_CODE (arg1) == COMPLEX_CST))
9520 tree subtype = TREE_TYPE (TREE_TYPE (arg0));
9521 tree real0, imag0, real1, imag1;
9523 arg0 = save_expr (arg0);
9524 arg1 = save_expr (arg1);
9525 real0 = fold (build1 (REALPART_EXPR, subtype, arg0));
9526 imag0 = fold (build1 (IMAGPART_EXPR, subtype, arg0));
9527 real1 = fold (build1 (REALPART_EXPR, subtype, arg1));
9528 imag1 = fold (build1 (IMAGPART_EXPR, subtype, arg1));
9530 return fold (build2 ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR
9533 fold (build2 (code, type, real0, real1)),
9534 fold (build2 (code, type, imag0, imag1))));
9537 /* Optimize comparisons of strlen vs zero to a compare of the
9538 first character of the string vs zero. To wit,
9539 strlen(ptr) == 0 => *ptr == 0
9540 strlen(ptr) != 0 => *ptr != 0
9541 Other cases should reduce to one of these two (or a constant)
9542 due to the return value of strlen being unsigned. */
9543 if ((code == EQ_EXPR || code == NE_EXPR)
9544 && integer_zerop (arg1)
9545 && TREE_CODE (arg0) == CALL_EXPR)
9547 tree fndecl = get_callee_fndecl (arg0);
9551 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
9552 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
9553 && (arglist = TREE_OPERAND (arg0, 1))
9554 && TREE_CODE (TREE_TYPE (TREE_VALUE (arglist))) == POINTER_TYPE
9555 && ! TREE_CHAIN (arglist))
9556 return fold (build2 (code, type,
9557 build1 (INDIRECT_REF, char_type_node,
9558 TREE_VALUE (arglist)),
9559 fold_convert (char_type_node,
9560 integer_zero_node)));
9563 /* We can fold X/C1 op C2 where C1 and C2 are integer constants
9564 into a single range test. */
9565 if ((TREE_CODE (arg0) == TRUNC_DIV_EXPR
9566 || TREE_CODE (arg0) == EXACT_DIV_EXPR)
9567 && TREE_CODE (arg1) == INTEGER_CST
9568 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
9569 && !integer_zerop (TREE_OPERAND (arg0, 1))
9570 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
9571 && !TREE_OVERFLOW (arg1))
9573 t1 = fold_div_compare (code, type, arg0, arg1);
9574 if (t1 != NULL_TREE)
9578 if ((code == EQ_EXPR || code == NE_EXPR)
9579 && !TREE_SIDE_EFFECTS (arg0)
9580 && integer_zerop (arg1)
9581 && tree_expr_nonzero_p (arg0))
9582 return constant_boolean_node (code==NE_EXPR, type);
9584 t1 = fold_relational_const (code, type, arg0, arg1);
9585 return t1 == NULL_TREE ? t : t1;
9587 case UNORDERED_EXPR:
9595 if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
9597 t1 = fold_relational_const (code, type, arg0, arg1);
9598 if (t1 != NULL_TREE)
9602 /* If the first operand is NaN, the result is constant. */
9603 if (TREE_CODE (arg0) == REAL_CST
9604 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
9605 && (code != LTGT_EXPR || ! flag_trapping_math))
9607 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
9610 return omit_one_operand (type, t1, arg1);
9613 /* If the second operand is NaN, the result is constant. */
9614 if (TREE_CODE (arg1) == REAL_CST
9615 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg1))
9616 && (code != LTGT_EXPR || ! flag_trapping_math))
9618 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
9621 return omit_one_operand (type, t1, arg0);
9624 /* Simplify unordered comparison of something with itself. */
9625 if ((code == UNLE_EXPR || code == UNGE_EXPR || code == UNEQ_EXPR)
9626 && operand_equal_p (arg0, arg1, 0))
9627 return constant_boolean_node (1, type);
9629 if (code == LTGT_EXPR
9630 && !flag_trapping_math
9631 && operand_equal_p (arg0, arg1, 0))
9632 return constant_boolean_node (0, type);
9634 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
9636 tree targ0 = strip_float_extensions (arg0);
9637 tree targ1 = strip_float_extensions (arg1);
9638 tree newtype = TREE_TYPE (targ0);
9640 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
9641 newtype = TREE_TYPE (targ1);
9643 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
9644 return fold (build2 (code, type, fold_convert (newtype, targ0),
9645 fold_convert (newtype, targ1)));
9651 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
9652 so all simple results must be passed through pedantic_non_lvalue. */
9653 if (TREE_CODE (arg0) == INTEGER_CST)
9655 tem = TREE_OPERAND (t, (integer_zerop (arg0) ? 2 : 1));
9656 /* Only optimize constant conditions when the selected branch
9657 has the same type as the COND_EXPR. This avoids optimizing
9658 away "c ? x : throw", where the throw has a void type. */
9659 if (! VOID_TYPE_P (TREE_TYPE (tem))
9660 || VOID_TYPE_P (type))
9661 return pedantic_non_lvalue (tem);
9664 if (operand_equal_p (arg1, TREE_OPERAND (t, 2), 0))
9665 return pedantic_omit_one_operand (type, arg1, arg0);
9667 /* If we have A op B ? A : C, we may be able to convert this to a
9668 simpler expression, depending on the operation and the values
9669 of B and C. Signed zeros prevent all of these transformations,
9670 for reasons given above each one.
9672 Also try swapping the arguments and inverting the conditional. */
9673 if (COMPARISON_CLASS_P (arg0)
9674 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
9675 arg1, TREE_OPERAND (arg0, 1))
9676 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
9678 tem = fold_cond_expr_with_comparison (type, arg0,
9679 TREE_OPERAND (t, 1),
9680 TREE_OPERAND (t, 2));
9685 if (COMPARISON_CLASS_P (arg0)
9686 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
9687 TREE_OPERAND (t, 2),
9688 TREE_OPERAND (arg0, 1))
9689 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (TREE_OPERAND (t, 2)))))
9691 tem = invert_truthvalue (arg0);
9692 if (COMPARISON_CLASS_P (tem))
9694 tem = fold_cond_expr_with_comparison (type, tem,
9695 TREE_OPERAND (t, 2),
9696 TREE_OPERAND (t, 1));
9702 /* If the second operand is simpler than the third, swap them
9703 since that produces better jump optimization results. */
9704 if (tree_swap_operands_p (TREE_OPERAND (t, 1),
9705 TREE_OPERAND (t, 2), false))
9707 /* See if this can be inverted. If it can't, possibly because
9708 it was a floating-point inequality comparison, don't do
9710 tem = invert_truthvalue (arg0);
9712 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
9713 return fold (build3 (code, type, tem,
9714 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1)));
9717 /* Convert A ? 1 : 0 to simply A. */
9718 if (integer_onep (TREE_OPERAND (t, 1))
9719 && integer_zerop (TREE_OPERAND (t, 2))
9720 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
9721 call to fold will try to move the conversion inside
9722 a COND, which will recurse. In that case, the COND_EXPR
9723 is probably the best choice, so leave it alone. */
9724 && type == TREE_TYPE (arg0))
9725 return pedantic_non_lvalue (arg0);
9727 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
9728 over COND_EXPR in cases such as floating point comparisons. */
9729 if (integer_zerop (TREE_OPERAND (t, 1))
9730 && integer_onep (TREE_OPERAND (t, 2))
9731 && truth_value_p (TREE_CODE (arg0)))
9732 return pedantic_non_lvalue (fold_convert (type,
9733 invert_truthvalue (arg0)));
9735 /* A < 0 ? <sign bit of A> : 0 is simply (A & <sign bit of A>). */
9736 if (TREE_CODE (arg0) == LT_EXPR
9737 && integer_zerop (TREE_OPERAND (arg0, 1))
9738 && integer_zerop (TREE_OPERAND (t, 2))
9739 && (tem = sign_bit_p (TREE_OPERAND (arg0, 0), arg1)))
9740 return fold_convert (type, fold (build2 (BIT_AND_EXPR,
9741 TREE_TYPE (tem), tem, arg1)));
9743 /* (A >> N) & 1 ? (1 << N) : 0 is simply A & (1 << N). A & 1 was
9744 already handled above. */
9745 if (TREE_CODE (arg0) == BIT_AND_EXPR
9746 && integer_onep (TREE_OPERAND (arg0, 1))
9747 && integer_zerop (TREE_OPERAND (t, 2))
9748 && integer_pow2p (arg1))
9750 tree tem = TREE_OPERAND (arg0, 0);
9752 if (TREE_CODE (tem) == RSHIFT_EXPR
9753 && TREE_CODE (TREE_OPERAND (tem, 1)) == INTEGER_CST
9754 && (unsigned HOST_WIDE_INT) tree_log2 (arg1) ==
9755 TREE_INT_CST_LOW (TREE_OPERAND (tem, 1)))
9756 return fold (build2 (BIT_AND_EXPR, type,
9757 TREE_OPERAND (tem, 0), arg1));
9760 /* A & N ? N : 0 is simply A & N if N is a power of two. This
9761 is probably obsolete because the first operand should be a
9762 truth value (that's why we have the two cases above), but let's
9763 leave it in until we can confirm this for all front-ends. */
9764 if (integer_zerop (TREE_OPERAND (t, 2))
9765 && TREE_CODE (arg0) == NE_EXPR
9766 && integer_zerop (TREE_OPERAND (arg0, 1))
9767 && integer_pow2p (arg1)
9768 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
9769 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
9770 arg1, OEP_ONLY_CONST))
9771 return pedantic_non_lvalue (fold_convert (type,
9772 TREE_OPERAND (arg0, 0)));
9774 /* Convert A ? B : 0 into A && B if A and B are truth values. */
9775 if (integer_zerop (TREE_OPERAND (t, 2))
9776 && truth_value_p (TREE_CODE (arg0))
9777 && truth_value_p (TREE_CODE (arg1)))
9778 return fold (build2 (TRUTH_ANDIF_EXPR, type, arg0, arg1));
9780 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
9781 if (integer_onep (TREE_OPERAND (t, 2))
9782 && truth_value_p (TREE_CODE (arg0))
9783 && truth_value_p (TREE_CODE (arg1)))
9785 /* Only perform transformation if ARG0 is easily inverted. */
9786 tem = invert_truthvalue (arg0);
9787 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
9788 return fold (build2 (TRUTH_ORIF_EXPR, type, tem, arg1));
9791 /* Convert A ? 0 : B into !A && B if A and B are truth values. */
9792 if (integer_zerop (arg1)
9793 && truth_value_p (TREE_CODE (arg0))
9794 && truth_value_p (TREE_CODE (TREE_OPERAND (t, 2))))
9796 /* Only perform transformation if ARG0 is easily inverted. */
9797 tem = invert_truthvalue (arg0);
9798 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
9799 return fold (build2 (TRUTH_ANDIF_EXPR, type, tem,
9800 TREE_OPERAND (t, 2)));
9803 /* Convert A ? 1 : B into A || B if A and B are truth values. */
9804 if (integer_onep (arg1)
9805 && truth_value_p (TREE_CODE (arg0))
9806 && truth_value_p (TREE_CODE (TREE_OPERAND (t, 2))))
9807 return fold (build2 (TRUTH_ORIF_EXPR, type, arg0,
9808 TREE_OPERAND (t, 2)));
9813 /* When pedantic, a compound expression can be neither an lvalue
9814 nor an integer constant expression. */
9815 if (TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
9817 /* Don't let (0, 0) be null pointer constant. */
9818 tem = integer_zerop (arg1) ? build1 (NOP_EXPR, type, arg1)
9819 : fold_convert (type, arg1);
9820 return pedantic_non_lvalue (tem);
9824 return build_complex (type, arg0, arg1);
9828 /* Check for a built-in function. */
9829 if (TREE_CODE (TREE_OPERAND (t, 0)) == ADDR_EXPR
9830 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0))
9832 && DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (t, 0), 0)))
9834 tree tmp = fold_builtin (t, false);
9842 } /* switch (code) */
9845 #ifdef ENABLE_FOLD_CHECKING
9848 static void fold_checksum_tree (tree, struct md5_ctx *, htab_t);
9849 static void fold_check_failed (tree, tree);
9850 void print_fold_checksum (tree);
9852 /* When --enable-checking=fold, compute a digest of expr before
9853 and after actual fold call to see if fold did not accidentally
9854 change original expr. */
9861 unsigned char checksum_before[16], checksum_after[16];
9864 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
9865 md5_init_ctx (&ctx);
9866 fold_checksum_tree (expr, &ctx, ht);
9867 md5_finish_ctx (&ctx, checksum_before);
9870 ret = fold_1 (expr);
9872 md5_init_ctx (&ctx);
9873 fold_checksum_tree (expr, &ctx, ht);
9874 md5_finish_ctx (&ctx, checksum_after);
9877 if (memcmp (checksum_before, checksum_after, 16))
9878 fold_check_failed (expr, ret);
9884 print_fold_checksum (tree expr)
9887 unsigned char checksum[16], cnt;
9890 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
9891 md5_init_ctx (&ctx);
9892 fold_checksum_tree (expr, &ctx, ht);
9893 md5_finish_ctx (&ctx, checksum);
9895 for (cnt = 0; cnt < 16; ++cnt)
9896 fprintf (stderr, "%02x", checksum[cnt]);
9897 putc ('\n', stderr);
9901 fold_check_failed (tree expr ATTRIBUTE_UNUSED, tree ret ATTRIBUTE_UNUSED)
9903 internal_error ("fold check: original tree changed by fold");
9907 fold_checksum_tree (tree expr, struct md5_ctx *ctx, htab_t ht)
9910 enum tree_code code;
9911 char buf[sizeof (struct tree_decl)];
9914 gcc_assert ((sizeof (struct tree_exp) + 5 * sizeof (tree)
9915 <= sizeof (struct tree_decl))
9916 && sizeof (struct tree_type) <= sizeof (struct tree_decl));
9919 slot = htab_find_slot (ht, expr, INSERT);
9923 code = TREE_CODE (expr);
9924 if (TREE_CODE_CLASS (code) == tcc_declaration
9925 && DECL_ASSEMBLER_NAME_SET_P (expr))
9927 /* Allow DECL_ASSEMBLER_NAME to be modified. */
9928 memcpy (buf, expr, tree_size (expr));
9930 SET_DECL_ASSEMBLER_NAME (expr, NULL);
9932 else if (TREE_CODE_CLASS (code) == tcc_type
9933 && (TYPE_POINTER_TO (expr) || TYPE_REFERENCE_TO (expr)
9934 || TYPE_CACHED_VALUES_P (expr)))
9936 /* Allow these fields to be modified. */
9937 memcpy (buf, expr, tree_size (expr));
9939 TYPE_POINTER_TO (expr) = NULL;
9940 TYPE_REFERENCE_TO (expr) = NULL;
9941 TYPE_CACHED_VALUES_P (expr) = 0;
9942 TYPE_CACHED_VALUES (expr) = NULL;
9944 md5_process_bytes (expr, tree_size (expr), ctx);
9945 fold_checksum_tree (TREE_TYPE (expr), ctx, ht);
9946 if (TREE_CODE_CLASS (code) != tcc_type
9947 && TREE_CODE_CLASS (code) != tcc_declaration)
9948 fold_checksum_tree (TREE_CHAIN (expr), ctx, ht);
9949 switch (TREE_CODE_CLASS (code))
9955 md5_process_bytes (TREE_STRING_POINTER (expr),
9956 TREE_STRING_LENGTH (expr), ctx);
9959 fold_checksum_tree (TREE_REALPART (expr), ctx, ht);
9960 fold_checksum_tree (TREE_IMAGPART (expr), ctx, ht);
9963 fold_checksum_tree (TREE_VECTOR_CST_ELTS (expr), ctx, ht);
9969 case tcc_exceptional:
9973 fold_checksum_tree (TREE_PURPOSE (expr), ctx, ht);
9974 fold_checksum_tree (TREE_VALUE (expr), ctx, ht);
9977 for (i = 0; i < TREE_VEC_LENGTH (expr); ++i)
9978 fold_checksum_tree (TREE_VEC_ELT (expr, i), ctx, ht);
9984 case tcc_expression:
9986 case tcc_comparison:
9990 len = TREE_CODE_LENGTH (code);
9991 for (i = 0; i < len; ++i)
9992 fold_checksum_tree (TREE_OPERAND (expr, i), ctx, ht);
9994 case tcc_declaration:
9995 fold_checksum_tree (DECL_SIZE (expr), ctx, ht);
9996 fold_checksum_tree (DECL_SIZE_UNIT (expr), ctx, ht);
9997 fold_checksum_tree (DECL_NAME (expr), ctx, ht);
9998 fold_checksum_tree (DECL_CONTEXT (expr), ctx, ht);
9999 fold_checksum_tree (DECL_ARGUMENTS (expr), ctx, ht);
10000 fold_checksum_tree (DECL_RESULT_FLD (expr), ctx, ht);
10001 fold_checksum_tree (DECL_INITIAL (expr), ctx, ht);
10002 fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr), ctx, ht);
10003 fold_checksum_tree (DECL_SECTION_NAME (expr), ctx, ht);
10004 fold_checksum_tree (DECL_ATTRIBUTES (expr), ctx, ht);
10005 fold_checksum_tree (DECL_VINDEX (expr), ctx, ht);
10008 if (TREE_CODE (expr) == ENUMERAL_TYPE)
10009 fold_checksum_tree (TYPE_VALUES (expr), ctx, ht);
10010 fold_checksum_tree (TYPE_SIZE (expr), ctx, ht);
10011 fold_checksum_tree (TYPE_SIZE_UNIT (expr), ctx, ht);
10012 fold_checksum_tree (TYPE_ATTRIBUTES (expr), ctx, ht);
10013 fold_checksum_tree (TYPE_NAME (expr), ctx, ht);
10014 if (INTEGRAL_TYPE_P (expr)
10015 || SCALAR_FLOAT_TYPE_P (expr))
10017 fold_checksum_tree (TYPE_MIN_VALUE (expr), ctx, ht);
10018 fold_checksum_tree (TYPE_MAX_VALUE (expr), ctx, ht);
10020 fold_checksum_tree (TYPE_MAIN_VARIANT (expr), ctx, ht);
10021 if (TREE_CODE (expr) == RECORD_TYPE
10022 || TREE_CODE (expr) == UNION_TYPE
10023 || TREE_CODE (expr) == QUAL_UNION_TYPE)
10024 fold_checksum_tree (TYPE_BINFO (expr), ctx, ht);
10025 fold_checksum_tree (TYPE_CONTEXT (expr), ctx, ht);
10034 /* Perform constant folding and related simplification of initializer
10035 expression EXPR. This behaves identically to "fold" but ignores
10036 potential run-time traps and exceptions that fold must preserve. */
10039 fold_initializer (tree expr)
10041 int saved_signaling_nans = flag_signaling_nans;
10042 int saved_trapping_math = flag_trapping_math;
10043 int saved_rounding_math = flag_rounding_math;
10044 int saved_trapv = flag_trapv;
10047 flag_signaling_nans = 0;
10048 flag_trapping_math = 0;
10049 flag_rounding_math = 0;
10052 result = fold (expr);
10054 flag_signaling_nans = saved_signaling_nans;
10055 flag_trapping_math = saved_trapping_math;
10056 flag_rounding_math = saved_rounding_math;
10057 flag_trapv = saved_trapv;
10062 /* Determine if first argument is a multiple of second argument. Return 0 if
10063 it is not, or we cannot easily determined it to be.
10065 An example of the sort of thing we care about (at this point; this routine
10066 could surely be made more general, and expanded to do what the *_DIV_EXPR's
10067 fold cases do now) is discovering that
10069 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
10075 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
10077 This code also handles discovering that
10079 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
10081 is a multiple of 8 so we don't have to worry about dealing with a
10082 possible remainder.
10084 Note that we *look* inside a SAVE_EXPR only to determine how it was
10085 calculated; it is not safe for fold to do much of anything else with the
10086 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
10087 at run time. For example, the latter example above *cannot* be implemented
10088 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
10089 evaluation time of the original SAVE_EXPR is not necessarily the same at
10090 the time the new expression is evaluated. The only optimization of this
10091 sort that would be valid is changing
10093 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
10097 SAVE_EXPR (I) * SAVE_EXPR (J)
10099 (where the same SAVE_EXPR (J) is used in the original and the
10100 transformed version). */
10103 multiple_of_p (tree type, tree top, tree bottom)
10105 if (operand_equal_p (top, bottom, 0))
10108 if (TREE_CODE (type) != INTEGER_TYPE)
10111 switch (TREE_CODE (top))
10114 /* Bitwise and provides a power of two multiple. If the mask is
10115 a multiple of BOTTOM then TOP is a multiple of BOTTOM. */
10116 if (!integer_pow2p (bottom))
10121 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
10122 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
10126 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
10127 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
10130 if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
10134 op1 = TREE_OPERAND (top, 1);
10135 /* const_binop may not detect overflow correctly,
10136 so check for it explicitly here. */
10137 if (TYPE_PRECISION (TREE_TYPE (size_one_node))
10138 > TREE_INT_CST_LOW (op1)
10139 && TREE_INT_CST_HIGH (op1) == 0
10140 && 0 != (t1 = fold_convert (type,
10141 const_binop (LSHIFT_EXPR,
10144 && ! TREE_OVERFLOW (t1))
10145 return multiple_of_p (type, t1, bottom);
10150 /* Can't handle conversions from non-integral or wider integral type. */
10151 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
10152 || (TYPE_PRECISION (type)
10153 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
10156 /* .. fall through ... */
10159 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
10162 if (TREE_CODE (bottom) != INTEGER_CST
10163 || (TYPE_UNSIGNED (type)
10164 && (tree_int_cst_sgn (top) < 0
10165 || tree_int_cst_sgn (bottom) < 0)))
10167 return integer_zerop (const_binop (TRUNC_MOD_EXPR,
10175 /* Return true if `t' is known to be non-negative. */
10178 tree_expr_nonnegative_p (tree t)
10180 switch (TREE_CODE (t))
10186 return tree_int_cst_sgn (t) >= 0;
10189 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
10192 if (FLOAT_TYPE_P (TREE_TYPE (t)))
10193 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
10194 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10196 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
10197 both unsigned and at least 2 bits shorter than the result. */
10198 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
10199 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
10200 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
10202 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
10203 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
10204 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
10205 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
10207 unsigned int prec = MAX (TYPE_PRECISION (inner1),
10208 TYPE_PRECISION (inner2)) + 1;
10209 return prec < TYPE_PRECISION (TREE_TYPE (t));
10215 if (FLOAT_TYPE_P (TREE_TYPE (t)))
10217 /* x * x for floating point x is always non-negative. */
10218 if (operand_equal_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1), 0))
10220 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
10221 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10224 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
10225 both unsigned and their total bits is shorter than the result. */
10226 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
10227 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
10228 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
10230 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
10231 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
10232 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
10233 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
10234 return TYPE_PRECISION (inner1) + TYPE_PRECISION (inner2)
10235 < TYPE_PRECISION (TREE_TYPE (t));
10239 case TRUNC_DIV_EXPR:
10240 case CEIL_DIV_EXPR:
10241 case FLOOR_DIV_EXPR:
10242 case ROUND_DIV_EXPR:
10243 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
10244 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10246 case TRUNC_MOD_EXPR:
10247 case CEIL_MOD_EXPR:
10248 case FLOOR_MOD_EXPR:
10249 case ROUND_MOD_EXPR:
10250 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
10253 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
10254 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10257 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
10258 || tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
10261 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
10262 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10266 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
10267 tree outer_type = TREE_TYPE (t);
10269 if (TREE_CODE (outer_type) == REAL_TYPE)
10271 if (TREE_CODE (inner_type) == REAL_TYPE)
10272 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
10273 if (TREE_CODE (inner_type) == INTEGER_TYPE)
10275 if (TYPE_UNSIGNED (inner_type))
10277 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
10280 else if (TREE_CODE (outer_type) == INTEGER_TYPE)
10282 if (TREE_CODE (inner_type) == REAL_TYPE)
10283 return tree_expr_nonnegative_p (TREE_OPERAND (t,0));
10284 if (TREE_CODE (inner_type) == INTEGER_TYPE)
10285 return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
10286 && TYPE_UNSIGNED (inner_type);
10292 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
10293 && tree_expr_nonnegative_p (TREE_OPERAND (t, 2));
10294 case COMPOUND_EXPR:
10295 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10297 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
10298 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10300 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
10301 || tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10303 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10305 return tree_expr_nonnegative_p (expr_last (TREE_OPERAND (t, 1)));
10307 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
10308 case NON_LVALUE_EXPR:
10309 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
10311 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
10315 tree temp = TARGET_EXPR_SLOT (t);
10316 t = TARGET_EXPR_INITIAL (t);
10318 /* If the initializer is non-void, then it's a normal expression
10319 that will be assigned to the slot. */
10320 if (!VOID_TYPE_P (t))
10321 return tree_expr_nonnegative_p (t);
10323 /* Otherwise, the initializer sets the slot in some way. One common
10324 way is an assignment statement at the end of the initializer. */
10327 if (TREE_CODE (t) == BIND_EXPR)
10328 t = expr_last (BIND_EXPR_BODY (t));
10329 else if (TREE_CODE (t) == TRY_FINALLY_EXPR
10330 || TREE_CODE (t) == TRY_CATCH_EXPR)
10331 t = expr_last (TREE_OPERAND (t, 0));
10332 else if (TREE_CODE (t) == STATEMENT_LIST)
10337 if (TREE_CODE (t) == MODIFY_EXPR
10338 && TREE_OPERAND (t, 0) == temp)
10339 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10346 tree fndecl = get_callee_fndecl (t);
10347 tree arglist = TREE_OPERAND (t, 1);
10348 if (fndecl && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
10349 switch (DECL_FUNCTION_CODE (fndecl))
10351 #define CASE_BUILTIN_F(BUILT_IN_FN) \
10352 case BUILT_IN_FN: case BUILT_IN_FN##F: case BUILT_IN_FN##L:
10353 #define CASE_BUILTIN_I(BUILT_IN_FN) \
10354 case BUILT_IN_FN: case BUILT_IN_FN##L: case BUILT_IN_FN##LL:
10356 CASE_BUILTIN_F (BUILT_IN_ACOS)
10357 CASE_BUILTIN_F (BUILT_IN_ACOSH)
10358 CASE_BUILTIN_F (BUILT_IN_CABS)
10359 CASE_BUILTIN_F (BUILT_IN_COSH)
10360 CASE_BUILTIN_F (BUILT_IN_ERFC)
10361 CASE_BUILTIN_F (BUILT_IN_EXP)
10362 CASE_BUILTIN_F (BUILT_IN_EXP10)
10363 CASE_BUILTIN_F (BUILT_IN_EXP2)
10364 CASE_BUILTIN_F (BUILT_IN_FABS)
10365 CASE_BUILTIN_F (BUILT_IN_FDIM)
10366 CASE_BUILTIN_F (BUILT_IN_FREXP)
10367 CASE_BUILTIN_F (BUILT_IN_HYPOT)
10368 CASE_BUILTIN_F (BUILT_IN_POW10)
10369 CASE_BUILTIN_I (BUILT_IN_FFS)
10370 CASE_BUILTIN_I (BUILT_IN_PARITY)
10371 CASE_BUILTIN_I (BUILT_IN_POPCOUNT)
10375 CASE_BUILTIN_F (BUILT_IN_SQRT)
10376 /* sqrt(-0.0) is -0.0. */
10377 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (t))))
10379 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
10381 CASE_BUILTIN_F (BUILT_IN_ASINH)
10382 CASE_BUILTIN_F (BUILT_IN_ATAN)
10383 CASE_BUILTIN_F (BUILT_IN_ATANH)
10384 CASE_BUILTIN_F (BUILT_IN_CBRT)
10385 CASE_BUILTIN_F (BUILT_IN_CEIL)
10386 CASE_BUILTIN_F (BUILT_IN_ERF)
10387 CASE_BUILTIN_F (BUILT_IN_EXPM1)
10388 CASE_BUILTIN_F (BUILT_IN_FLOOR)
10389 CASE_BUILTIN_F (BUILT_IN_FMOD)
10390 CASE_BUILTIN_F (BUILT_IN_LDEXP)
10391 CASE_BUILTIN_F (BUILT_IN_LLRINT)
10392 CASE_BUILTIN_F (BUILT_IN_LLROUND)
10393 CASE_BUILTIN_F (BUILT_IN_LRINT)
10394 CASE_BUILTIN_F (BUILT_IN_LROUND)
10395 CASE_BUILTIN_F (BUILT_IN_MODF)
10396 CASE_BUILTIN_F (BUILT_IN_NEARBYINT)
10397 CASE_BUILTIN_F (BUILT_IN_POW)
10398 CASE_BUILTIN_F (BUILT_IN_RINT)
10399 CASE_BUILTIN_F (BUILT_IN_ROUND)
10400 CASE_BUILTIN_F (BUILT_IN_SIGNBIT)
10401 CASE_BUILTIN_F (BUILT_IN_SINH)
10402 CASE_BUILTIN_F (BUILT_IN_TANH)
10403 CASE_BUILTIN_F (BUILT_IN_TRUNC)
10404 /* True if the 1st argument is nonnegative. */
10405 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
10407 CASE_BUILTIN_F (BUILT_IN_FMAX)
10408 /* True if the 1st OR 2nd arguments are nonnegative. */
10409 return tree_expr_nonnegative_p (TREE_VALUE (arglist))
10410 || tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist)));
10412 CASE_BUILTIN_F (BUILT_IN_FMIN)
10413 /* True if the 1st AND 2nd arguments are nonnegative. */
10414 return tree_expr_nonnegative_p (TREE_VALUE (arglist))
10415 && tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist)));
10417 CASE_BUILTIN_F (BUILT_IN_COPYSIGN)
10418 /* True if the 2nd argument is nonnegative. */
10419 return tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist)));
10423 #undef CASE_BUILTIN_F
10424 #undef CASE_BUILTIN_I
10428 /* ... fall through ... */
10431 if (truth_value_p (TREE_CODE (t)))
10432 /* Truth values evaluate to 0 or 1, which is nonnegative. */
10436 /* We don't know sign of `t', so be conservative and return false. */
10440 /* Return true when T is an address and is known to be nonzero.
10441 For floating point we further ensure that T is not denormal.
10442 Similar logic is present in nonzero_address in rtlanal.h. */
10445 tree_expr_nonzero_p (tree t)
10447 tree type = TREE_TYPE (t);
10449 /* Doing something useful for floating point would need more work. */
10450 if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
10453 switch (TREE_CODE (t))
10456 if (!TYPE_UNSIGNED (type) && !flag_wrapv)
10457 return tree_expr_nonzero_p (TREE_OPERAND (t, 0));
10460 /* We used to test for !integer_zerop here. This does not work correctly
10461 if TREE_CONSTANT_OVERFLOW (t). */
10462 return (TREE_INT_CST_LOW (t) != 0
10463 || TREE_INT_CST_HIGH (t) != 0);
10466 if (!TYPE_UNSIGNED (type) && !flag_wrapv)
10468 /* With the presence of negative values it is hard
10469 to say something. */
10470 if (!tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
10471 || !tree_expr_nonnegative_p (TREE_OPERAND (t, 1)))
10473 /* One of operands must be positive and the other non-negative. */
10474 return (tree_expr_nonzero_p (TREE_OPERAND (t, 0))
10475 || tree_expr_nonzero_p (TREE_OPERAND (t, 1)));
10480 if (!TYPE_UNSIGNED (type) && !flag_wrapv)
10482 return (tree_expr_nonzero_p (TREE_OPERAND (t, 0))
10483 && tree_expr_nonzero_p (TREE_OPERAND (t, 1)));
10489 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
10490 tree outer_type = TREE_TYPE (t);
10492 return (TYPE_PRECISION (inner_type) >= TYPE_PRECISION (outer_type)
10493 && tree_expr_nonzero_p (TREE_OPERAND (t, 0)));
10499 tree base = get_base_address (TREE_OPERAND (t, 0));
10504 /* Weak declarations may link to NULL. */
10506 return !DECL_WEAK (base);
10508 /* Constants are never weak. */
10509 if (CONSTANT_CLASS_P (base))
10516 return (tree_expr_nonzero_p (TREE_OPERAND (t, 1))
10517 && tree_expr_nonzero_p (TREE_OPERAND (t, 2)));
10520 return (tree_expr_nonzero_p (TREE_OPERAND (t, 0))
10521 && tree_expr_nonzero_p (TREE_OPERAND (t, 1)));
10524 if (tree_expr_nonzero_p (TREE_OPERAND (t, 0)))
10526 /* When both operands are nonzero, then MAX must be too. */
10527 if (tree_expr_nonzero_p (TREE_OPERAND (t, 1)))
10530 /* MAX where operand 0 is positive is positive. */
10531 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
10533 /* MAX where operand 1 is positive is positive. */
10534 else if (tree_expr_nonzero_p (TREE_OPERAND (t, 1))
10535 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1)))
10539 case COMPOUND_EXPR:
10542 return tree_expr_nonzero_p (TREE_OPERAND (t, 1));
10545 case NON_LVALUE_EXPR:
10546 return tree_expr_nonzero_p (TREE_OPERAND (t, 0));
10549 return tree_expr_nonzero_p (TREE_OPERAND (t, 1))
10550 || tree_expr_nonzero_p (TREE_OPERAND (t, 0));
10558 /* See if we are applying CODE, a relational to the highest or lowest
10559 possible integer of TYPE. If so, then the result is a compile
10563 fold_relational_hi_lo (enum tree_code *code_p, const tree type, tree *op0_p,
10568 enum tree_code code = *code_p;
10569 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (op1)));
10571 if (TREE_CODE (op1) == INTEGER_CST
10572 && ! TREE_CONSTANT_OVERFLOW (op1)
10573 && width <= HOST_BITS_PER_WIDE_INT
10574 && (INTEGRAL_TYPE_P (TREE_TYPE (op1))
10575 || POINTER_TYPE_P (TREE_TYPE (op1))))
10577 unsigned HOST_WIDE_INT signed_max;
10578 unsigned HOST_WIDE_INT max, min;
10580 signed_max = ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1;
10582 if (TYPE_UNSIGNED (TREE_TYPE (op1)))
10584 max = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
10590 min = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
10593 if (TREE_INT_CST_HIGH (op1) == 0
10594 && TREE_INT_CST_LOW (op1) == max)
10598 return omit_one_operand (type, integer_zero_node, op0);
10604 return omit_one_operand (type, integer_one_node, op0);
10610 /* The GE_EXPR and LT_EXPR cases above are not normally
10611 reached because of previous transformations. */
10616 else if (TREE_INT_CST_HIGH (op1) == 0
10617 && TREE_INT_CST_LOW (op1) == max - 1)
10622 *op1_p = const_binop (PLUS_EXPR, op1, integer_one_node, 0);
10626 *op1_p = const_binop (PLUS_EXPR, op1, integer_one_node, 0);
10631 else if (TREE_INT_CST_HIGH (op1) == (min ? -1 : 0)
10632 && TREE_INT_CST_LOW (op1) == min)
10636 return omit_one_operand (type, integer_zero_node, op0);
10643 return omit_one_operand (type, integer_one_node, op0);
10652 else if (TREE_INT_CST_HIGH (op1) == (min ? -1 : 0)
10653 && TREE_INT_CST_LOW (op1) == min + 1)
10658 *op1_p = const_binop (MINUS_EXPR, op1, integer_one_node, 0);
10662 *op1_p = const_binop (MINUS_EXPR, op1, integer_one_node, 0);
10668 else if (TREE_INT_CST_HIGH (op1) == 0
10669 && TREE_INT_CST_LOW (op1) == signed_max
10670 && TYPE_UNSIGNED (TREE_TYPE (op1))
10671 /* signed_type does not work on pointer types. */
10672 && INTEGRAL_TYPE_P (TREE_TYPE (op1)))
10674 /* The following case also applies to X < signed_max+1
10675 and X >= signed_max+1 because previous transformations. */
10676 if (code == LE_EXPR || code == GT_EXPR)
10678 tree st0, st1, exp, retval;
10679 st0 = lang_hooks.types.signed_type (TREE_TYPE (op0));
10680 st1 = lang_hooks.types.signed_type (TREE_TYPE (op1));
10682 exp = build2 (code == LE_EXPR ? GE_EXPR: LT_EXPR,
10684 fold_convert (st0, op0),
10685 fold_convert (st1, integer_zero_node));
10687 retval = fold_binary_to_constant (TREE_CODE (exp),
10689 TREE_OPERAND (exp, 0),
10690 TREE_OPERAND (exp, 1));
10692 /* If we are in gimple form, then returning EXP would create
10693 non-gimple expressions. Clearing it is safe and insures
10694 we do not allow a non-gimple expression to escape. */
10695 if (in_gimple_form)
10698 return (retval ? retval : exp);
10707 /* Given the components of a binary expression CODE, TYPE, OP0 and OP1,
10708 attempt to fold the expression to a constant without modifying TYPE,
10711 If the expression could be simplified to a constant, then return
10712 the constant. If the expression would not be simplified to a
10713 constant, then return NULL_TREE.
10715 Note this is primarily designed to be called after gimplification
10716 of the tree structures and when at least one operand is a constant.
10717 As a result of those simplifying assumptions this routine is far
10718 simpler than the generic fold routine. */
10721 fold_binary_to_constant (enum tree_code code, tree type, tree op0, tree op1)
10728 /* If this is a commutative operation, and ARG0 is a constant, move it
10729 to ARG1 to reduce the number of tests below. */
10730 if (commutative_tree_code (code)
10731 && (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST))
10738 /* If either operand is a complex type, extract its real component. */
10739 if (TREE_CODE (op0) == COMPLEX_CST)
10740 subop0 = TREE_REALPART (op0);
10744 if (TREE_CODE (op1) == COMPLEX_CST)
10745 subop1 = TREE_REALPART (op1);
10749 /* Note if either argument is not a real or integer constant.
10750 With a few exceptions, simplification is limited to cases
10751 where both arguments are constants. */
10752 if ((TREE_CODE (subop0) != INTEGER_CST
10753 && TREE_CODE (subop0) != REAL_CST)
10754 || (TREE_CODE (subop1) != INTEGER_CST
10755 && TREE_CODE (subop1) != REAL_CST))
10761 /* (plus (address) (const_int)) is a constant. */
10762 if (TREE_CODE (op0) == PLUS_EXPR
10763 && TREE_CODE (op1) == INTEGER_CST
10764 && (TREE_CODE (TREE_OPERAND (op0, 0)) == ADDR_EXPR
10765 || (TREE_CODE (TREE_OPERAND (op0, 0)) == NOP_EXPR
10766 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (op0, 0), 0))
10768 && TREE_CODE (TREE_OPERAND (op0, 1)) == INTEGER_CST)
10770 return build2 (PLUS_EXPR, type, TREE_OPERAND (op0, 0),
10771 const_binop (PLUS_EXPR, op1,
10772 TREE_OPERAND (op0, 1), 0));
10780 /* Both arguments are constants. Simplify. */
10781 tem = const_binop (code, op0, op1, 0);
10782 if (tem != NULL_TREE)
10784 /* The return value should always have the same type as
10785 the original expression. */
10786 if (TREE_TYPE (tem) != type)
10787 tem = fold_convert (type, tem);
10794 /* Fold &x - &x. This can happen from &x.foo - &x.
10795 This is unsafe for certain floats even in non-IEEE formats.
10796 In IEEE, it is unsafe because it does wrong for NaNs.
10797 Also note that operand_equal_p is always false if an
10798 operand is volatile. */
10799 if (! FLOAT_TYPE_P (type) && operand_equal_p (op0, op1, 0))
10800 return fold_convert (type, integer_zero_node);
10806 /* Special case multiplication or bitwise AND where one argument
10808 if (! FLOAT_TYPE_P (type) && integer_zerop (op1))
10809 return omit_one_operand (type, op1, op0);
10811 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (op0)))
10812 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (op0)))
10813 && real_zerop (op1))
10814 return omit_one_operand (type, op1, op0);
10819 /* Special case when we know the result will be all ones. */
10820 if (integer_all_onesp (op1))
10821 return omit_one_operand (type, op1, op0);
10825 case TRUNC_DIV_EXPR:
10826 case ROUND_DIV_EXPR:
10827 case FLOOR_DIV_EXPR:
10828 case CEIL_DIV_EXPR:
10829 case EXACT_DIV_EXPR:
10830 case TRUNC_MOD_EXPR:
10831 case ROUND_MOD_EXPR:
10832 case FLOOR_MOD_EXPR:
10833 case CEIL_MOD_EXPR:
10835 /* Division by zero is undefined. */
10836 if (integer_zerop (op1))
10839 if (TREE_CODE (op1) == REAL_CST
10840 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (op1)))
10841 && real_zerop (op1))
10847 if (INTEGRAL_TYPE_P (type)
10848 && operand_equal_p (op1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
10849 return omit_one_operand (type, op1, op0);
10854 if (INTEGRAL_TYPE_P (type)
10855 && TYPE_MAX_VALUE (type)
10856 && operand_equal_p (op1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
10857 return omit_one_operand (type, op1, op0);
10862 /* Optimize -1 >> x for arithmetic right shifts. */
10863 if (integer_all_onesp (op0) && ! TYPE_UNSIGNED (type))
10864 return omit_one_operand (type, op0, op1);
10865 /* ... fall through ... */
10868 if (integer_zerop (op0))
10869 return omit_one_operand (type, op0, op1);
10871 /* Since negative shift count is not well-defined, don't
10872 try to compute it in the compiler. */
10873 if (TREE_CODE (op1) == INTEGER_CST && tree_int_cst_sgn (op1) < 0)
10880 /* -1 rotated either direction by any amount is still -1. */
10881 if (integer_all_onesp (op0))
10882 return omit_one_operand (type, op0, op1);
10884 /* 0 rotated either direction by any amount is still zero. */
10885 if (integer_zerop (op0))
10886 return omit_one_operand (type, op0, op1);
10892 return build_complex (type, op0, op1);
10901 /* If one arg is a real or integer constant, put it last. */
10902 if ((TREE_CODE (op0) == INTEGER_CST
10903 && TREE_CODE (op1) != INTEGER_CST)
10904 || (TREE_CODE (op0) == REAL_CST
10905 && TREE_CODE (op0) != REAL_CST))
10912 code = swap_tree_comparison (code);
10915 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
10916 This transformation affects the cases which are handled in later
10917 optimizations involving comparisons with non-negative constants. */
10918 if (TREE_CODE (op1) == INTEGER_CST
10919 && TREE_CODE (op0) != INTEGER_CST
10920 && tree_int_cst_sgn (op1) > 0)
10926 op1 = const_binop (MINUS_EXPR, op1, integer_one_node, 0);
10931 op1 = const_binop (MINUS_EXPR, op1, integer_one_node, 0);
10939 tem = fold_relational_hi_lo (&code, type, &op0, &op1);
10943 /* Fall through. */
10946 case UNORDERED_EXPR:
10956 return fold_relational_const (code, type, op0, op1);
10959 /* This could probably be handled. */
10962 case TRUTH_AND_EXPR:
10963 /* If second arg is constant zero, result is zero, but first arg
10964 must be evaluated. */
10965 if (integer_zerop (op1))
10966 return omit_one_operand (type, op1, op0);
10967 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
10968 case will be handled here. */
10969 if (integer_zerop (op0))
10970 return omit_one_operand (type, op0, op1);
10971 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
10972 return constant_boolean_node (true, type);
10975 case TRUTH_OR_EXPR:
10976 /* If second arg is constant true, result is true, but we must
10977 evaluate first arg. */
10978 if (TREE_CODE (op1) == INTEGER_CST && ! integer_zerop (op1))
10979 return omit_one_operand (type, op1, op0);
10980 /* Likewise for first arg, but note this only occurs here for
10982 if (TREE_CODE (op0) == INTEGER_CST && ! integer_zerop (op0))
10983 return omit_one_operand (type, op0, op1);
10984 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
10985 return constant_boolean_node (false, type);
10988 case TRUTH_XOR_EXPR:
10989 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
10991 int x = ! integer_zerop (op0) ^ ! integer_zerop (op1);
10992 return constant_boolean_node (x, type);
11001 /* Given the components of a unary expression CODE, TYPE and OP0,
11002 attempt to fold the expression to a constant without modifying
11005 If the expression could be simplified to a constant, then return
11006 the constant. If the expression would not be simplified to a
11007 constant, then return NULL_TREE.
11009 Note this is primarily designed to be called after gimplification
11010 of the tree structures and when op0 is a constant. As a result
11011 of those simplifying assumptions this routine is far simpler than
11012 the generic fold routine. */
11015 fold_unary_to_constant (enum tree_code code, tree type, tree op0)
11017 /* Make sure we have a suitable constant argument. */
11018 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
11022 if (TREE_CODE (op0) == COMPLEX_CST)
11023 subop = TREE_REALPART (op0);
11027 if (TREE_CODE (subop) != INTEGER_CST && TREE_CODE (subop) != REAL_CST)
11036 case FIX_TRUNC_EXPR:
11037 case FIX_FLOOR_EXPR:
11038 case FIX_CEIL_EXPR:
11039 return fold_convert_const (code, type, op0);
11042 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
11043 return fold_negate_const (op0, type);
11048 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
11049 return fold_abs_const (op0, type);
11054 if (TREE_CODE (op0) == INTEGER_CST)
11055 return fold_not_const (op0, type);
11059 case REALPART_EXPR:
11060 if (TREE_CODE (op0) == COMPLEX_CST)
11061 return TREE_REALPART (op0);
11065 case IMAGPART_EXPR:
11066 if (TREE_CODE (op0) == COMPLEX_CST)
11067 return TREE_IMAGPART (op0);
11072 if (TREE_CODE (op0) == COMPLEX_CST
11073 && TREE_CODE (TREE_TYPE (op0)) == COMPLEX_TYPE)
11074 return build_complex (type, TREE_REALPART (op0),
11075 negate_expr (TREE_IMAGPART (op0)));
11083 /* If EXP represents referencing an element in a constant string
11084 (either via pointer arithmetic or array indexing), return the
11085 tree representing the value accessed, otherwise return NULL. */
11088 fold_read_from_constant_string (tree exp)
11090 if (TREE_CODE (exp) == INDIRECT_REF || TREE_CODE (exp) == ARRAY_REF)
11092 tree exp1 = TREE_OPERAND (exp, 0);
11096 if (TREE_CODE (exp) == INDIRECT_REF)
11097 string = string_constant (exp1, &index);
11100 tree low_bound = array_ref_low_bound (exp);
11101 index = fold_convert (sizetype, TREE_OPERAND (exp, 1));
11103 /* Optimize the special-case of a zero lower bound.
11105 We convert the low_bound to sizetype to avoid some problems
11106 with constant folding. (E.g. suppose the lower bound is 1,
11107 and its mode is QI. Without the conversion,l (ARRAY
11108 +(INDEX-(unsigned char)1)) becomes ((ARRAY+(-(unsigned char)1))
11109 +INDEX), which becomes (ARRAY+255+INDEX). Opps!) */
11110 if (! integer_zerop (low_bound))
11111 index = size_diffop (index, fold_convert (sizetype, low_bound));
11117 && TREE_TYPE (exp) == TREE_TYPE (TREE_TYPE (string))
11118 && TREE_CODE (string) == STRING_CST
11119 && TREE_CODE (index) == INTEGER_CST
11120 && compare_tree_int (index, TREE_STRING_LENGTH (string)) < 0
11121 && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (string))))
11123 && (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))) == 1))
11124 return fold_convert (TREE_TYPE (exp),
11125 build_int_cst (NULL_TREE,
11126 (TREE_STRING_POINTER (string)
11127 [TREE_INT_CST_LOW (index)])));
11132 /* Return the tree for neg (ARG0) when ARG0 is known to be either
11133 an integer constant or real constant.
11135 TYPE is the type of the result. */
11138 fold_negate_const (tree arg0, tree type)
11140 tree t = NULL_TREE;
11142 switch (TREE_CODE (arg0))
11146 unsigned HOST_WIDE_INT low;
11147 HOST_WIDE_INT high;
11148 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
11149 TREE_INT_CST_HIGH (arg0),
11151 t = build_int_cst_wide (type, low, high);
11152 t = force_fit_type (t, 1,
11153 (overflow | TREE_OVERFLOW (arg0))
11154 && !TYPE_UNSIGNED (type),
11155 TREE_CONSTANT_OVERFLOW (arg0));
11160 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
11164 gcc_unreachable ();
11170 /* Return the tree for abs (ARG0) when ARG0 is known to be either
11171 an integer constant or real constant.
11173 TYPE is the type of the result. */
11176 fold_abs_const (tree arg0, tree type)
11178 tree t = NULL_TREE;
11180 switch (TREE_CODE (arg0))
11183 /* If the value is unsigned, then the absolute value is
11184 the same as the ordinary value. */
11185 if (TYPE_UNSIGNED (type))
11187 /* Similarly, if the value is non-negative. */
11188 else if (INT_CST_LT (integer_minus_one_node, arg0))
11190 /* If the value is negative, then the absolute value is
11194 unsigned HOST_WIDE_INT low;
11195 HOST_WIDE_INT high;
11196 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
11197 TREE_INT_CST_HIGH (arg0),
11199 t = build_int_cst_wide (type, low, high);
11200 t = force_fit_type (t, -1, overflow | TREE_OVERFLOW (arg0),
11201 TREE_CONSTANT_OVERFLOW (arg0));
11206 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
11207 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
11213 gcc_unreachable ();
11219 /* Return the tree for not (ARG0) when ARG0 is known to be an integer
11220 constant. TYPE is the type of the result. */
11223 fold_not_const (tree arg0, tree type)
11225 tree t = NULL_TREE;
11227 gcc_assert (TREE_CODE (arg0) == INTEGER_CST);
11229 t = build_int_cst_wide (type,
11230 ~ TREE_INT_CST_LOW (arg0),
11231 ~ TREE_INT_CST_HIGH (arg0));
11232 t = force_fit_type (t, 0, TREE_OVERFLOW (arg0),
11233 TREE_CONSTANT_OVERFLOW (arg0));
11238 /* Given CODE, a relational operator, the target type, TYPE and two
11239 constant operands OP0 and OP1, return the result of the
11240 relational operation. If the result is not a compile time
11241 constant, then return NULL_TREE. */
11244 fold_relational_const (enum tree_code code, tree type, tree op0, tree op1)
11246 int result, invert;
11248 /* From here on, the only cases we handle are when the result is
11249 known to be a constant. */
11251 if (TREE_CODE (op0) == REAL_CST && TREE_CODE (op1) == REAL_CST)
11253 const REAL_VALUE_TYPE *c0 = TREE_REAL_CST_PTR (op0);
11254 const REAL_VALUE_TYPE *c1 = TREE_REAL_CST_PTR (op1);
11256 /* Handle the cases where either operand is a NaN. */
11257 if (real_isnan (c0) || real_isnan (c1))
11267 case UNORDERED_EXPR:
11281 if (flag_trapping_math)
11287 gcc_unreachable ();
11290 return constant_boolean_node (result, type);
11293 return constant_boolean_node (real_compare (code, c0, c1), type);
11296 /* From here on we only handle LT, LE, GT, GE, EQ and NE.
11298 To compute GT, swap the arguments and do LT.
11299 To compute GE, do LT and invert the result.
11300 To compute LE, swap the arguments, do LT and invert the result.
11301 To compute NE, do EQ and invert the result.
11303 Therefore, the code below must handle only EQ and LT. */
11305 if (code == LE_EXPR || code == GT_EXPR)
11310 code = swap_tree_comparison (code);
11313 /* Note that it is safe to invert for real values here because we
11314 have already handled the one case that it matters. */
11317 if (code == NE_EXPR || code == GE_EXPR)
11320 code = invert_tree_comparison (code, false);
11323 /* Compute a result for LT or EQ if args permit;
11324 Otherwise return T. */
11325 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
11327 if (code == EQ_EXPR)
11328 result = tree_int_cst_equal (op0, op1);
11329 else if (TYPE_UNSIGNED (TREE_TYPE (op0)))
11330 result = INT_CST_LT_UNSIGNED (op0, op1);
11332 result = INT_CST_LT (op0, op1);
11339 return constant_boolean_node (result, type);
11342 /* Build an expression for the a clean point containing EXPR with type TYPE.
11343 Don't build a cleanup point expression for EXPR which don't have side
11347 fold_build_cleanup_point_expr (tree type, tree expr)
11349 /* If the expression does not have side effects then we don't have to wrap
11350 it with a cleanup point expression. */
11351 if (!TREE_SIDE_EFFECTS (expr))
11354 /* If the expression is a return, check to see if the expression inside the
11355 return has no side effects or the right hand side of the modify expression
11356 inside the return. If either don't have side effects set we don't need to
11357 wrap the expression in a cleanup point expression. Note we don't check the
11358 left hand side of the modify because it should always be a return decl. */
11359 if (TREE_CODE (expr) == RETURN_EXPR)
11361 tree op = TREE_OPERAND (expr, 0);
11362 if (!op || !TREE_SIDE_EFFECTS (op))
11364 op = TREE_OPERAND (op, 1);
11365 if (!TREE_SIDE_EFFECTS (op))
11369 return build1 (CLEANUP_POINT_EXPR, type, expr);
11372 /* Build an expression for the address of T. Folds away INDIRECT_REF to
11373 avoid confusing the gimplify process. */
11376 build_fold_addr_expr_with_type (tree t, tree ptrtype)
11378 /* The size of the object is not relevant when talking about its address. */
11379 if (TREE_CODE (t) == WITH_SIZE_EXPR)
11380 t = TREE_OPERAND (t, 0);
11382 /* Note: doesn't apply to ALIGN_INDIRECT_REF */
11383 if (TREE_CODE (t) == INDIRECT_REF
11384 || TREE_CODE (t) == MISALIGNED_INDIRECT_REF)
11386 t = TREE_OPERAND (t, 0);
11387 if (TREE_TYPE (t) != ptrtype)
11388 t = build1 (NOP_EXPR, ptrtype, t);
11394 while (handled_component_p (base))
11395 base = TREE_OPERAND (base, 0);
11397 TREE_ADDRESSABLE (base) = 1;
11399 t = build1 (ADDR_EXPR, ptrtype, t);
11406 build_fold_addr_expr (tree t)
11408 return build_fold_addr_expr_with_type (t, build_pointer_type (TREE_TYPE (t)));
11411 /* Given a pointer value T, return a simplified version of an indirection
11412 through T, or NULL_TREE if no simplification is possible. */
11415 fold_indirect_ref_1 (tree t)
11417 tree type = TREE_TYPE (TREE_TYPE (t));
11422 subtype = TREE_TYPE (sub);
11423 if (!POINTER_TYPE_P (subtype))
11426 if (TREE_CODE (sub) == ADDR_EXPR)
11428 tree op = TREE_OPERAND (sub, 0);
11429 tree optype = TREE_TYPE (op);
11431 if (lang_hooks.types_compatible_p (type, optype))
11433 /* *(foo *)&fooarray => fooarray[0] */
11434 else if (TREE_CODE (optype) == ARRAY_TYPE
11435 && lang_hooks.types_compatible_p (type, TREE_TYPE (optype)))
11437 tree type_domain = TYPE_DOMAIN (optype);
11438 tree min_val = size_zero_node;
11439 if (type_domain && TYPE_MIN_VALUE (type_domain))
11440 min_val = TYPE_MIN_VALUE (type_domain);
11441 return build4 (ARRAY_REF, type, op, min_val, NULL_TREE, NULL_TREE);
11445 /* *(foo *)fooarrptr => (*fooarrptr)[0] */
11446 if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE
11447 && lang_hooks.types_compatible_p (type, TREE_TYPE (TREE_TYPE (subtype))))
11450 tree min_val = size_zero_node;
11451 sub = build_fold_indirect_ref (sub);
11452 type_domain = TYPE_DOMAIN (TREE_TYPE (sub));
11453 if (type_domain && TYPE_MIN_VALUE (type_domain))
11454 min_val = TYPE_MIN_VALUE (type_domain);
11455 return build4 (ARRAY_REF, type, sub, min_val, NULL_TREE, NULL_TREE);
11461 /* Builds an expression for an indirection through T, simplifying some
11465 build_fold_indirect_ref (tree t)
11467 tree sub = fold_indirect_ref_1 (t);
11472 return build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (t)), t);
11475 /* Given an INDIRECT_REF T, return either T or a simplified version. */
11478 fold_indirect_ref (tree t)
11480 tree sub = fold_indirect_ref_1 (TREE_OPERAND (t, 0));
11488 /* Strip non-trapping, non-side-effecting tree nodes from an expression
11489 whose result is ignored. The type of the returned tree need not be
11490 the same as the original expression. */
11493 fold_ignored_result (tree t)
11495 if (!TREE_SIDE_EFFECTS (t))
11496 return integer_zero_node;
11499 switch (TREE_CODE_CLASS (TREE_CODE (t)))
11502 t = TREE_OPERAND (t, 0);
11506 case tcc_comparison:
11507 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
11508 t = TREE_OPERAND (t, 0);
11509 else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0)))
11510 t = TREE_OPERAND (t, 1);
11515 case tcc_expression:
11516 switch (TREE_CODE (t))
11518 case COMPOUND_EXPR:
11519 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
11521 t = TREE_OPERAND (t, 0);
11525 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1))
11526 || TREE_SIDE_EFFECTS (TREE_OPERAND (t, 2)))
11528 t = TREE_OPERAND (t, 0);
11541 /* Return the value of VALUE, rounded up to a multiple of DIVISOR.
11542 This can only be applied to objects of a sizetype. */
11545 round_up (tree value, int divisor)
11547 tree div = NULL_TREE;
11549 gcc_assert (divisor > 0);
11553 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
11554 have to do anything. Only do this when we are not given a const,
11555 because in that case, this check is more expensive than just
11557 if (TREE_CODE (value) != INTEGER_CST)
11559 div = build_int_cst (TREE_TYPE (value), divisor);
11561 if (multiple_of_p (TREE_TYPE (value), value, div))
11565 /* If divisor is a power of two, simplify this to bit manipulation. */
11566 if (divisor == (divisor & -divisor))
11570 t = build_int_cst (TREE_TYPE (value), divisor - 1);
11571 value = size_binop (PLUS_EXPR, value, t);
11572 t = build_int_cst (TREE_TYPE (value), -divisor);
11573 value = size_binop (BIT_AND_EXPR, value, t);
11578 div = build_int_cst (TREE_TYPE (value), divisor);
11579 value = size_binop (CEIL_DIV_EXPR, value, div);
11580 value = size_binop (MULT_EXPR, value, div);
11586 /* Likewise, but round down. */
11589 round_down (tree value, int divisor)
11591 tree div = NULL_TREE;
11593 gcc_assert (divisor > 0);
11597 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
11598 have to do anything. Only do this when we are not given a const,
11599 because in that case, this check is more expensive than just
11601 if (TREE_CODE (value) != INTEGER_CST)
11603 div = build_int_cst (TREE_TYPE (value), divisor);
11605 if (multiple_of_p (TREE_TYPE (value), value, div))
11609 /* If divisor is a power of two, simplify this to bit manipulation. */
11610 if (divisor == (divisor & -divisor))
11614 t = build_int_cst (TREE_TYPE (value), -divisor);
11615 value = size_binop (BIT_AND_EXPR, value, t);
11620 div = build_int_cst (TREE_TYPE (value), divisor);
11621 value = size_binop (FLOOR_DIV_EXPR, value, div);
11622 value = size_binop (MULT_EXPR, value, div);
11628 /* Returns the pointer to the base of the object addressed by EXP and
11629 extracts the information about the offset of the access, storing it
11630 to PBITPOS and POFFSET. */
11633 split_address_to_core_and_offset (tree exp,
11634 HOST_WIDE_INT *pbitpos, tree *poffset)
11637 enum machine_mode mode;
11638 int unsignedp, volatilep;
11639 HOST_WIDE_INT bitsize;
11641 if (TREE_CODE (exp) == ADDR_EXPR)
11643 core = get_inner_reference (TREE_OPERAND (exp, 0), &bitsize, pbitpos,
11644 poffset, &mode, &unsignedp, &volatilep,
11647 if (TREE_CODE (core) == INDIRECT_REF)
11648 core = TREE_OPERAND (core, 0);
11654 *poffset = NULL_TREE;
11660 /* Returns true if addresses of E1 and E2 differ by a constant, false
11661 otherwise. If they do, E1 - E2 is stored in *DIFF. */
11664 ptr_difference_const (tree e1, tree e2, HOST_WIDE_INT *diff)
11667 HOST_WIDE_INT bitpos1, bitpos2;
11668 tree toffset1, toffset2, tdiff, type;
11670 core1 = split_address_to_core_and_offset (e1, &bitpos1, &toffset1);
11671 core2 = split_address_to_core_and_offset (e2, &bitpos2, &toffset2);
11673 if (bitpos1 % BITS_PER_UNIT != 0
11674 || bitpos2 % BITS_PER_UNIT != 0
11675 || !operand_equal_p (core1, core2, 0))
11678 if (toffset1 && toffset2)
11680 type = TREE_TYPE (toffset1);
11681 if (type != TREE_TYPE (toffset2))
11682 toffset2 = fold_convert (type, toffset2);
11684 tdiff = fold (build2 (MINUS_EXPR, type, toffset1, toffset2));
11685 if (!host_integerp (tdiff, 0))
11688 *diff = tree_low_cst (tdiff, 0);
11690 else if (toffset1 || toffset2)
11692 /* If only one of the offsets is non-constant, the difference cannot
11699 *diff += (bitpos1 - bitpos2) / BITS_PER_UNIT;
11703 /* Simplify the floating point expression EXP when the sign of the
11704 result is not significant. Return NULL_TREE if no simplification
11708 fold_strip_sign_ops (tree exp)
11712 switch (TREE_CODE (exp))
11716 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
11717 return arg0 ? arg0 : TREE_OPERAND (exp, 0);
11721 if (HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (exp))))
11723 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
11724 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
11725 if (arg0 != NULL_TREE || arg1 != NULL_TREE)
11726 return fold (build2 (TREE_CODE (exp), TREE_TYPE (exp),
11727 arg0 ? arg0 : TREE_OPERAND (exp, 0),
11728 arg1 ? arg1 : TREE_OPERAND (exp, 1)));