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 (enum tree_code, tree, tree,
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. */
1522 if (flag_rounding_math
1523 && (inexact || !real_identical (&result, &value)))
1526 t = build_real (type, result);
1528 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2);
1529 TREE_CONSTANT_OVERFLOW (t)
1531 | TREE_CONSTANT_OVERFLOW (arg1)
1532 | TREE_CONSTANT_OVERFLOW (arg2);
1535 if (TREE_CODE (arg1) == COMPLEX_CST)
1537 tree type = TREE_TYPE (arg1);
1538 tree r1 = TREE_REALPART (arg1);
1539 tree i1 = TREE_IMAGPART (arg1);
1540 tree r2 = TREE_REALPART (arg2);
1541 tree i2 = TREE_IMAGPART (arg2);
1547 t = build_complex (type,
1548 const_binop (PLUS_EXPR, r1, r2, notrunc),
1549 const_binop (PLUS_EXPR, i1, i2, notrunc));
1553 t = build_complex (type,
1554 const_binop (MINUS_EXPR, r1, r2, notrunc),
1555 const_binop (MINUS_EXPR, i1, i2, notrunc));
1559 t = build_complex (type,
1560 const_binop (MINUS_EXPR,
1561 const_binop (MULT_EXPR,
1563 const_binop (MULT_EXPR,
1566 const_binop (PLUS_EXPR,
1567 const_binop (MULT_EXPR,
1569 const_binop (MULT_EXPR,
1577 = const_binop (PLUS_EXPR,
1578 const_binop (MULT_EXPR, r2, r2, notrunc),
1579 const_binop (MULT_EXPR, i2, i2, notrunc),
1582 t = build_complex (type,
1584 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1585 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1586 const_binop (PLUS_EXPR,
1587 const_binop (MULT_EXPR, r1, r2,
1589 const_binop (MULT_EXPR, i1, i2,
1592 magsquared, notrunc),
1594 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1595 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1596 const_binop (MINUS_EXPR,
1597 const_binop (MULT_EXPR, i1, r2,
1599 const_binop (MULT_EXPR, r1, i2,
1602 magsquared, notrunc));
1614 /* Create a size type INT_CST node with NUMBER sign extended. KIND
1615 indicates which particular sizetype to create. */
1618 size_int_kind (HOST_WIDE_INT number, enum size_type_kind kind)
1620 return build_int_cst (sizetype_tab[(int) kind], number);
1623 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1624 is a tree code. The type of the result is taken from the operands.
1625 Both must be the same type integer type and it must be a size type.
1626 If the operands are constant, so is the result. */
1629 size_binop (enum tree_code code, tree arg0, tree arg1)
1631 tree type = TREE_TYPE (arg0);
1633 gcc_assert (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type)
1634 && type == TREE_TYPE (arg1));
1636 /* Handle the special case of two integer constants faster. */
1637 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1639 /* And some specific cases even faster than that. */
1640 if (code == PLUS_EXPR && integer_zerop (arg0))
1642 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1643 && integer_zerop (arg1))
1645 else if (code == MULT_EXPR && integer_onep (arg0))
1648 /* Handle general case of two integer constants. */
1649 return int_const_binop (code, arg0, arg1, 0);
1652 if (arg0 == error_mark_node || arg1 == error_mark_node)
1653 return error_mark_node;
1655 return fold (build2 (code, type, arg0, arg1));
1658 /* Given two values, either both of sizetype or both of bitsizetype,
1659 compute the difference between the two values. Return the value
1660 in signed type corresponding to the type of the operands. */
1663 size_diffop (tree arg0, tree arg1)
1665 tree type = TREE_TYPE (arg0);
1668 gcc_assert (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type)
1669 && type == TREE_TYPE (arg1));
1671 /* If the type is already signed, just do the simple thing. */
1672 if (!TYPE_UNSIGNED (type))
1673 return size_binop (MINUS_EXPR, arg0, arg1);
1675 ctype = type == bitsizetype ? sbitsizetype : ssizetype;
1677 /* If either operand is not a constant, do the conversions to the signed
1678 type and subtract. The hardware will do the right thing with any
1679 overflow in the subtraction. */
1680 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
1681 return size_binop (MINUS_EXPR, fold_convert (ctype, arg0),
1682 fold_convert (ctype, arg1));
1684 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
1685 Otherwise, subtract the other way, convert to CTYPE (we know that can't
1686 overflow) and negate (which can't either). Special-case a result
1687 of zero while we're here. */
1688 if (tree_int_cst_equal (arg0, arg1))
1689 return fold_convert (ctype, integer_zero_node);
1690 else if (tree_int_cst_lt (arg1, arg0))
1691 return fold_convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
1693 return size_binop (MINUS_EXPR, fold_convert (ctype, integer_zero_node),
1694 fold_convert (ctype, size_binop (MINUS_EXPR,
1698 /* A subroutine of fold_convert_const handling conversions of an
1699 INTEGER_CST to another integer type. */
1702 fold_convert_const_int_from_int (tree type, tree arg1)
1706 /* Given an integer constant, make new constant with new type,
1707 appropriately sign-extended or truncated. */
1708 t = build_int_cst_wide (type, TREE_INT_CST_LOW (arg1),
1709 TREE_INT_CST_HIGH (arg1));
1711 t = force_fit_type (t,
1712 /* Don't set the overflow when
1713 converting a pointer */
1714 !POINTER_TYPE_P (TREE_TYPE (arg1)),
1715 (TREE_INT_CST_HIGH (arg1) < 0
1716 && (TYPE_UNSIGNED (type)
1717 < TYPE_UNSIGNED (TREE_TYPE (arg1))))
1718 | TREE_OVERFLOW (arg1),
1719 TREE_CONSTANT_OVERFLOW (arg1));
1724 /* A subroutine of fold_convert_const handling conversions a REAL_CST
1725 to an integer type. */
1728 fold_convert_const_int_from_real (enum tree_code code, tree type, tree arg1)
1733 /* The following code implements the floating point to integer
1734 conversion rules required by the Java Language Specification,
1735 that IEEE NaNs are mapped to zero and values that overflow
1736 the target precision saturate, i.e. values greater than
1737 INT_MAX are mapped to INT_MAX, and values less than INT_MIN
1738 are mapped to INT_MIN. These semantics are allowed by the
1739 C and C++ standards that simply state that the behavior of
1740 FP-to-integer conversion is unspecified upon overflow. */
1742 HOST_WIDE_INT high, low;
1744 REAL_VALUE_TYPE x = TREE_REAL_CST (arg1);
1748 case FIX_TRUNC_EXPR:
1749 real_trunc (&r, VOIDmode, &x);
1753 real_ceil (&r, VOIDmode, &x);
1756 case FIX_FLOOR_EXPR:
1757 real_floor (&r, VOIDmode, &x);
1760 case FIX_ROUND_EXPR:
1761 real_round (&r, VOIDmode, &x);
1768 /* If R is NaN, return zero and show we have an overflow. */
1769 if (REAL_VALUE_ISNAN (r))
1776 /* See if R is less than the lower bound or greater than the
1781 tree lt = TYPE_MIN_VALUE (type);
1782 REAL_VALUE_TYPE l = real_value_from_int_cst (NULL_TREE, lt);
1783 if (REAL_VALUES_LESS (r, l))
1786 high = TREE_INT_CST_HIGH (lt);
1787 low = TREE_INT_CST_LOW (lt);
1793 tree ut = TYPE_MAX_VALUE (type);
1796 REAL_VALUE_TYPE u = real_value_from_int_cst (NULL_TREE, ut);
1797 if (REAL_VALUES_LESS (u, r))
1800 high = TREE_INT_CST_HIGH (ut);
1801 low = TREE_INT_CST_LOW (ut);
1807 REAL_VALUE_TO_INT (&low, &high, r);
1809 t = build_int_cst_wide (type, low, high);
1811 t = force_fit_type (t, -1, overflow | TREE_OVERFLOW (arg1),
1812 TREE_CONSTANT_OVERFLOW (arg1));
1816 /* A subroutine of fold_convert_const handling conversions a REAL_CST
1817 to another floating point type. */
1820 fold_convert_const_real_from_real (tree type, tree arg1)
1822 REAL_VALUE_TYPE value;
1825 real_convert (&value, TYPE_MODE (type), &TREE_REAL_CST (arg1));
1826 t = build_real (type, value);
1828 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1);
1829 TREE_CONSTANT_OVERFLOW (t)
1830 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1834 /* Attempt to fold type conversion operation CODE of expression ARG1 to
1835 type TYPE. If no simplification can be done return NULL_TREE. */
1838 fold_convert_const (enum tree_code code, tree type, tree arg1)
1840 if (TREE_TYPE (arg1) == type)
1843 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
1845 if (TREE_CODE (arg1) == INTEGER_CST)
1846 return fold_convert_const_int_from_int (type, arg1);
1847 else if (TREE_CODE (arg1) == REAL_CST)
1848 return fold_convert_const_int_from_real (code, type, arg1);
1850 else if (TREE_CODE (type) == REAL_TYPE)
1852 if (TREE_CODE (arg1) == INTEGER_CST)
1853 return build_real_from_int_cst (type, arg1);
1854 if (TREE_CODE (arg1) == REAL_CST)
1855 return fold_convert_const_real_from_real (type, arg1);
1860 /* Construct a vector of zero elements of vector type TYPE. */
1863 build_zero_vector (tree type)
1868 elem = fold_convert_const (NOP_EXPR, TREE_TYPE (type), integer_zero_node);
1869 units = TYPE_VECTOR_SUBPARTS (type);
1872 for (i = 0; i < units; i++)
1873 list = tree_cons (NULL_TREE, elem, list);
1874 return build_vector (type, list);
1877 /* Convert expression ARG to type TYPE. Used by the middle-end for
1878 simple conversions in preference to calling the front-end's convert. */
1881 fold_convert (tree type, tree arg)
1883 tree orig = TREE_TYPE (arg);
1889 if (TREE_CODE (arg) == ERROR_MARK
1890 || TREE_CODE (type) == ERROR_MARK
1891 || TREE_CODE (orig) == ERROR_MARK)
1892 return error_mark_node;
1894 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig)
1895 || lang_hooks.types_compatible_p (TYPE_MAIN_VARIANT (type),
1896 TYPE_MAIN_VARIANT (orig)))
1897 return fold (build1 (NOP_EXPR, type, arg));
1899 switch (TREE_CODE (type))
1901 case INTEGER_TYPE: case CHAR_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
1902 case POINTER_TYPE: case REFERENCE_TYPE:
1904 if (TREE_CODE (arg) == INTEGER_CST)
1906 tem = fold_convert_const (NOP_EXPR, type, arg);
1907 if (tem != NULL_TREE)
1910 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
1911 || TREE_CODE (orig) == OFFSET_TYPE)
1912 return fold (build1 (NOP_EXPR, type, arg));
1913 if (TREE_CODE (orig) == COMPLEX_TYPE)
1915 tem = fold (build1 (REALPART_EXPR, TREE_TYPE (orig), arg));
1916 return fold_convert (type, tem);
1918 gcc_assert (TREE_CODE (orig) == VECTOR_TYPE
1919 && tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
1920 return fold (build1 (NOP_EXPR, type, arg));
1923 if (TREE_CODE (arg) == INTEGER_CST)
1925 tem = fold_convert_const (FLOAT_EXPR, type, arg);
1926 if (tem != NULL_TREE)
1929 else if (TREE_CODE (arg) == REAL_CST)
1931 tem = fold_convert_const (NOP_EXPR, type, arg);
1932 if (tem != NULL_TREE)
1936 switch (TREE_CODE (orig))
1938 case INTEGER_TYPE: case CHAR_TYPE:
1939 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
1940 case POINTER_TYPE: case REFERENCE_TYPE:
1941 return fold (build1 (FLOAT_EXPR, type, arg));
1944 return fold (build1 (flag_float_store ? CONVERT_EXPR : NOP_EXPR,
1948 tem = fold (build1 (REALPART_EXPR, TREE_TYPE (orig), arg));
1949 return fold_convert (type, tem);
1956 switch (TREE_CODE (orig))
1958 case INTEGER_TYPE: case CHAR_TYPE:
1959 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
1960 case POINTER_TYPE: case REFERENCE_TYPE:
1962 return build2 (COMPLEX_EXPR, type,
1963 fold_convert (TREE_TYPE (type), arg),
1964 fold_convert (TREE_TYPE (type), integer_zero_node));
1969 if (TREE_CODE (arg) == COMPLEX_EXPR)
1971 rpart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 0));
1972 ipart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 1));
1973 return fold (build2 (COMPLEX_EXPR, type, rpart, ipart));
1976 arg = save_expr (arg);
1977 rpart = fold (build1 (REALPART_EXPR, TREE_TYPE (orig), arg));
1978 ipart = fold (build1 (IMAGPART_EXPR, TREE_TYPE (orig), arg));
1979 rpart = fold_convert (TREE_TYPE (type), rpart);
1980 ipart = fold_convert (TREE_TYPE (type), ipart);
1981 return fold (build2 (COMPLEX_EXPR, type, rpart, ipart));
1989 if (integer_zerop (arg))
1990 return build_zero_vector (type);
1991 gcc_assert (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
1992 gcc_assert (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
1993 || TREE_CODE (orig) == VECTOR_TYPE);
1994 return fold (build1 (NOP_EXPR, type, arg));
1997 return fold (build1 (CONVERT_EXPR, type, fold_ignored_result (arg)));
2004 /* Return an expr equal to X but certainly not valid as an lvalue. */
2009 /* While we are in GIMPLE, NON_LVALUE_EXPR doesn't mean anything to
2014 /* We only need to wrap lvalue tree codes. */
2015 switch (TREE_CODE (x))
2026 case ALIGN_INDIRECT_REF:
2027 case MISALIGNED_INDIRECT_REF:
2029 case ARRAY_RANGE_REF:
2035 case PREINCREMENT_EXPR:
2036 case PREDECREMENT_EXPR:
2038 case TRY_CATCH_EXPR:
2039 case WITH_CLEANUP_EXPR:
2050 /* Assume the worst for front-end tree codes. */
2051 if ((int)TREE_CODE (x) >= NUM_TREE_CODES)
2055 return build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
2058 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
2059 Zero means allow extended lvalues. */
2061 int pedantic_lvalues;
2063 /* When pedantic, return an expr equal to X but certainly not valid as a
2064 pedantic lvalue. Otherwise, return X. */
2067 pedantic_non_lvalue (tree x)
2069 if (pedantic_lvalues)
2070 return non_lvalue (x);
2075 /* Given a tree comparison code, return the code that is the logical inverse
2076 of the given code. It is not safe to do this for floating-point
2077 comparisons, except for NE_EXPR and EQ_EXPR, so we receive a machine mode
2078 as well: if reversing the comparison is unsafe, return ERROR_MARK. */
2080 static enum tree_code
2081 invert_tree_comparison (enum tree_code code, bool honor_nans)
2083 if (honor_nans && flag_trapping_math)
2093 return honor_nans ? UNLE_EXPR : LE_EXPR;
2095 return honor_nans ? UNLT_EXPR : LT_EXPR;
2097 return honor_nans ? UNGE_EXPR : GE_EXPR;
2099 return honor_nans ? UNGT_EXPR : GT_EXPR;
2113 return UNORDERED_EXPR;
2114 case UNORDERED_EXPR:
2115 return ORDERED_EXPR;
2121 /* Similar, but return the comparison that results if the operands are
2122 swapped. This is safe for floating-point. */
2125 swap_tree_comparison (enum tree_code code)
2146 /* Convert a comparison tree code from an enum tree_code representation
2147 into a compcode bit-based encoding. This function is the inverse of
2148 compcode_to_comparison. */
2150 static enum comparison_code
2151 comparison_to_compcode (enum tree_code code)
2168 return COMPCODE_ORD;
2169 case UNORDERED_EXPR:
2170 return COMPCODE_UNORD;
2172 return COMPCODE_UNLT;
2174 return COMPCODE_UNEQ;
2176 return COMPCODE_UNLE;
2178 return COMPCODE_UNGT;
2180 return COMPCODE_LTGT;
2182 return COMPCODE_UNGE;
2188 /* Convert a compcode bit-based encoding of a comparison operator back
2189 to GCC's enum tree_code representation. This function is the
2190 inverse of comparison_to_compcode. */
2192 static enum tree_code
2193 compcode_to_comparison (enum comparison_code code)
2210 return ORDERED_EXPR;
2211 case COMPCODE_UNORD:
2212 return UNORDERED_EXPR;
2230 /* Return a tree for the comparison which is the combination of
2231 doing the AND or OR (depending on CODE) of the two operations LCODE
2232 and RCODE on the identical operands LL_ARG and LR_ARG. Take into account
2233 the possibility of trapping if the mode has NaNs, and return NULL_TREE
2234 if this makes the transformation invalid. */
2237 combine_comparisons (enum tree_code code, enum tree_code lcode,
2238 enum tree_code rcode, tree truth_type,
2239 tree ll_arg, tree lr_arg)
2241 bool honor_nans = HONOR_NANS (TYPE_MODE (TREE_TYPE (ll_arg)));
2242 enum comparison_code lcompcode = comparison_to_compcode (lcode);
2243 enum comparison_code rcompcode = comparison_to_compcode (rcode);
2244 enum comparison_code compcode;
2248 case TRUTH_AND_EXPR: case TRUTH_ANDIF_EXPR:
2249 compcode = lcompcode & rcompcode;
2252 case TRUTH_OR_EXPR: case TRUTH_ORIF_EXPR:
2253 compcode = lcompcode | rcompcode;
2262 /* Eliminate unordered comparisons, as well as LTGT and ORD
2263 which are not used unless the mode has NaNs. */
2264 compcode &= ~COMPCODE_UNORD;
2265 if (compcode == COMPCODE_LTGT)
2266 compcode = COMPCODE_NE;
2267 else if (compcode == COMPCODE_ORD)
2268 compcode = COMPCODE_TRUE;
2270 else if (flag_trapping_math)
2272 /* Check that the original operation and the optimized ones will trap
2273 under the same condition. */
2274 bool ltrap = (lcompcode & COMPCODE_UNORD) == 0
2275 && (lcompcode != COMPCODE_EQ)
2276 && (lcompcode != COMPCODE_ORD);
2277 bool rtrap = (rcompcode & COMPCODE_UNORD) == 0
2278 && (rcompcode != COMPCODE_EQ)
2279 && (rcompcode != COMPCODE_ORD);
2280 bool trap = (compcode & COMPCODE_UNORD) == 0
2281 && (compcode != COMPCODE_EQ)
2282 && (compcode != COMPCODE_ORD);
2284 /* In a short-circuited boolean expression the LHS might be
2285 such that the RHS, if evaluated, will never trap. For
2286 example, in ORD (x, y) && (x < y), we evaluate the RHS only
2287 if neither x nor y is NaN. (This is a mixed blessing: for
2288 example, the expression above will never trap, hence
2289 optimizing it to x < y would be invalid). */
2290 if ((code == TRUTH_ORIF_EXPR && (lcompcode & COMPCODE_UNORD))
2291 || (code == TRUTH_ANDIF_EXPR && !(lcompcode & COMPCODE_UNORD)))
2294 /* If the comparison was short-circuited, and only the RHS
2295 trapped, we may now generate a spurious trap. */
2297 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2300 /* If we changed the conditions that cause a trap, we lose. */
2301 if ((ltrap || rtrap) != trap)
2305 if (compcode == COMPCODE_TRUE)
2306 return constant_boolean_node (true, truth_type);
2307 else if (compcode == COMPCODE_FALSE)
2308 return constant_boolean_node (false, truth_type);
2310 return fold (build2 (compcode_to_comparison (compcode),
2311 truth_type, ll_arg, lr_arg));
2314 /* Return nonzero if CODE is a tree code that represents a truth value. */
2317 truth_value_p (enum tree_code code)
2319 return (TREE_CODE_CLASS (code) == tcc_comparison
2320 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2321 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2322 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
2325 /* Return nonzero if two operands (typically of the same tree node)
2326 are necessarily equal. If either argument has side-effects this
2327 function returns zero. FLAGS modifies behavior as follows:
2329 If OEP_ONLY_CONST is set, only return nonzero for constants.
2330 This function tests whether the operands are indistinguishable;
2331 it does not test whether they are equal using C's == operation.
2332 The distinction is important for IEEE floating point, because
2333 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2334 (2) two NaNs may be indistinguishable, but NaN!=NaN.
2336 If OEP_ONLY_CONST is unset, a VAR_DECL is considered equal to itself
2337 even though it may hold multiple values during a function.
2338 This is because a GCC tree node guarantees that nothing else is
2339 executed between the evaluation of its "operands" (which may often
2340 be evaluated in arbitrary order). Hence if the operands themselves
2341 don't side-effect, the VAR_DECLs, PARM_DECLs etc... must hold the
2342 same value in each operand/subexpression. Hence leaving OEP_ONLY_CONST
2343 unset means assuming isochronic (or instantaneous) tree equivalence.
2344 Unless comparing arbitrary expression trees, such as from different
2345 statements, this flag can usually be left unset.
2347 If OEP_PURE_SAME is set, then pure functions with identical arguments
2348 are considered the same. It is used when the caller has other ways
2349 to ensure that global memory is unchanged in between. */
2352 operand_equal_p (tree arg0, tree arg1, unsigned int flags)
2354 /* If either is ERROR_MARK, they aren't equal. */
2355 if (TREE_CODE (arg0) == ERROR_MARK || TREE_CODE (arg1) == ERROR_MARK)
2358 /* If both types don't have the same signedness, then we can't consider
2359 them equal. We must check this before the STRIP_NOPS calls
2360 because they may change the signedness of the arguments. */
2361 if (TYPE_UNSIGNED (TREE_TYPE (arg0)) != TYPE_UNSIGNED (TREE_TYPE (arg1)))
2367 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2368 /* This is needed for conversions and for COMPONENT_REF.
2369 Might as well play it safe and always test this. */
2370 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
2371 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
2372 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
2375 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
2376 We don't care about side effects in that case because the SAVE_EXPR
2377 takes care of that for us. In all other cases, two expressions are
2378 equal if they have no side effects. If we have two identical
2379 expressions with side effects that should be treated the same due
2380 to the only side effects being identical SAVE_EXPR's, that will
2381 be detected in the recursive calls below. */
2382 if (arg0 == arg1 && ! (flags & OEP_ONLY_CONST)
2383 && (TREE_CODE (arg0) == SAVE_EXPR
2384 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
2387 /* Next handle constant cases, those for which we can return 1 even
2388 if ONLY_CONST is set. */
2389 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
2390 switch (TREE_CODE (arg0))
2393 return (! TREE_CONSTANT_OVERFLOW (arg0)
2394 && ! TREE_CONSTANT_OVERFLOW (arg1)
2395 && tree_int_cst_equal (arg0, arg1));
2398 return (! TREE_CONSTANT_OVERFLOW (arg0)
2399 && ! TREE_CONSTANT_OVERFLOW (arg1)
2400 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
2401 TREE_REAL_CST (arg1)));
2407 if (TREE_CONSTANT_OVERFLOW (arg0)
2408 || TREE_CONSTANT_OVERFLOW (arg1))
2411 v1 = TREE_VECTOR_CST_ELTS (arg0);
2412 v2 = TREE_VECTOR_CST_ELTS (arg1);
2415 if (!operand_equal_p (TREE_VALUE (v1), TREE_VALUE (v2),
2418 v1 = TREE_CHAIN (v1);
2419 v2 = TREE_CHAIN (v2);
2426 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
2428 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
2432 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
2433 && ! memcmp (TREE_STRING_POINTER (arg0),
2434 TREE_STRING_POINTER (arg1),
2435 TREE_STRING_LENGTH (arg0)));
2438 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
2444 if (flags & OEP_ONLY_CONST)
2447 /* Define macros to test an operand from arg0 and arg1 for equality and a
2448 variant that allows null and views null as being different from any
2449 non-null value. In the latter case, if either is null, the both
2450 must be; otherwise, do the normal comparison. */
2451 #define OP_SAME(N) operand_equal_p (TREE_OPERAND (arg0, N), \
2452 TREE_OPERAND (arg1, N), flags)
2454 #define OP_SAME_WITH_NULL(N) \
2455 ((!TREE_OPERAND (arg0, N) || !TREE_OPERAND (arg1, N)) \
2456 ? TREE_OPERAND (arg0, N) == TREE_OPERAND (arg1, N) : OP_SAME (N))
2458 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
2461 /* Two conversions are equal only if signedness and modes match. */
2462 switch (TREE_CODE (arg0))
2467 case FIX_TRUNC_EXPR:
2468 case FIX_FLOOR_EXPR:
2469 case FIX_ROUND_EXPR:
2470 if (TYPE_UNSIGNED (TREE_TYPE (arg0))
2471 != TYPE_UNSIGNED (TREE_TYPE (arg1)))
2481 case tcc_comparison:
2483 if (OP_SAME (0) && OP_SAME (1))
2486 /* For commutative ops, allow the other order. */
2487 return (commutative_tree_code (TREE_CODE (arg0))
2488 && operand_equal_p (TREE_OPERAND (arg0, 0),
2489 TREE_OPERAND (arg1, 1), flags)
2490 && operand_equal_p (TREE_OPERAND (arg0, 1),
2491 TREE_OPERAND (arg1, 0), flags));
2494 /* If either of the pointer (or reference) expressions we are
2495 dereferencing contain a side effect, these cannot be equal. */
2496 if (TREE_SIDE_EFFECTS (arg0)
2497 || TREE_SIDE_EFFECTS (arg1))
2500 switch (TREE_CODE (arg0))
2503 case ALIGN_INDIRECT_REF:
2504 case MISALIGNED_INDIRECT_REF:
2510 case ARRAY_RANGE_REF:
2511 /* Operands 2 and 3 may be null. */
2514 && OP_SAME_WITH_NULL (2)
2515 && OP_SAME_WITH_NULL (3));
2518 /* Handle operand 2 the same as for ARRAY_REF. */
2519 return OP_SAME (0) && OP_SAME (1) && OP_SAME_WITH_NULL (2);
2522 return OP_SAME (0) && OP_SAME (1) && OP_SAME (2);
2528 case tcc_expression:
2529 switch (TREE_CODE (arg0))
2532 case TRUTH_NOT_EXPR:
2535 case TRUTH_ANDIF_EXPR:
2536 case TRUTH_ORIF_EXPR:
2537 return OP_SAME (0) && OP_SAME (1);
2539 case TRUTH_AND_EXPR:
2541 case TRUTH_XOR_EXPR:
2542 if (OP_SAME (0) && OP_SAME (1))
2545 /* Otherwise take into account this is a commutative operation. */
2546 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2547 TREE_OPERAND (arg1, 1), flags)
2548 && operand_equal_p (TREE_OPERAND (arg0, 1),
2549 TREE_OPERAND (arg1, 0), flags));
2552 /* If the CALL_EXPRs call different functions, then they
2553 clearly can not be equal. */
2558 unsigned int cef = call_expr_flags (arg0);
2559 if (flags & OEP_PURE_SAME)
2560 cef &= ECF_CONST | ECF_PURE;
2567 /* Now see if all the arguments are the same. operand_equal_p
2568 does not handle TREE_LIST, so we walk the operands here
2569 feeding them to operand_equal_p. */
2570 arg0 = TREE_OPERAND (arg0, 1);
2571 arg1 = TREE_OPERAND (arg1, 1);
2572 while (arg0 && arg1)
2574 if (! operand_equal_p (TREE_VALUE (arg0), TREE_VALUE (arg1),
2578 arg0 = TREE_CHAIN (arg0);
2579 arg1 = TREE_CHAIN (arg1);
2582 /* If we get here and both argument lists are exhausted
2583 then the CALL_EXPRs are equal. */
2584 return ! (arg0 || arg1);
2590 case tcc_declaration:
2591 /* Consider __builtin_sqrt equal to sqrt. */
2592 return (TREE_CODE (arg0) == FUNCTION_DECL
2593 && DECL_BUILT_IN (arg0) && DECL_BUILT_IN (arg1)
2594 && DECL_BUILT_IN_CLASS (arg0) == DECL_BUILT_IN_CLASS (arg1)
2595 && DECL_FUNCTION_CODE (arg0) == DECL_FUNCTION_CODE (arg1));
2602 #undef OP_SAME_WITH_NULL
2605 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2606 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2608 When in doubt, return 0. */
2611 operand_equal_for_comparison_p (tree arg0, tree arg1, tree other)
2613 int unsignedp1, unsignedpo;
2614 tree primarg0, primarg1, primother;
2615 unsigned int correct_width;
2617 if (operand_equal_p (arg0, arg1, 0))
2620 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
2621 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
2624 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2625 and see if the inner values are the same. This removes any
2626 signedness comparison, which doesn't matter here. */
2627 primarg0 = arg0, primarg1 = arg1;
2628 STRIP_NOPS (primarg0);
2629 STRIP_NOPS (primarg1);
2630 if (operand_equal_p (primarg0, primarg1, 0))
2633 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2634 actual comparison operand, ARG0.
2636 First throw away any conversions to wider types
2637 already present in the operands. */
2639 primarg1 = get_narrower (arg1, &unsignedp1);
2640 primother = get_narrower (other, &unsignedpo);
2642 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
2643 if (unsignedp1 == unsignedpo
2644 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
2645 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
2647 tree type = TREE_TYPE (arg0);
2649 /* Make sure shorter operand is extended the right way
2650 to match the longer operand. */
2651 primarg1 = fold_convert (lang_hooks.types.signed_or_unsigned_type
2652 (unsignedp1, TREE_TYPE (primarg1)), primarg1);
2654 if (operand_equal_p (arg0, fold_convert (type, primarg1), 0))
2661 /* See if ARG is an expression that is either a comparison or is performing
2662 arithmetic on comparisons. The comparisons must only be comparing
2663 two different values, which will be stored in *CVAL1 and *CVAL2; if
2664 they are nonzero it means that some operands have already been found.
2665 No variables may be used anywhere else in the expression except in the
2666 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2667 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2669 If this is true, return 1. Otherwise, return zero. */
2672 twoval_comparison_p (tree arg, tree *cval1, tree *cval2, int *save_p)
2674 enum tree_code code = TREE_CODE (arg);
2675 enum tree_code_class class = TREE_CODE_CLASS (code);
2677 /* We can handle some of the tcc_expression cases here. */
2678 if (class == tcc_expression && code == TRUTH_NOT_EXPR)
2680 else if (class == tcc_expression
2681 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
2682 || code == COMPOUND_EXPR))
2685 else if (class == tcc_expression && code == SAVE_EXPR
2686 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
2688 /* If we've already found a CVAL1 or CVAL2, this expression is
2689 two complex to handle. */
2690 if (*cval1 || *cval2)
2700 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
2703 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
2704 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2705 cval1, cval2, save_p));
2710 case tcc_expression:
2711 if (code == COND_EXPR)
2712 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
2713 cval1, cval2, save_p)
2714 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2715 cval1, cval2, save_p)
2716 && twoval_comparison_p (TREE_OPERAND (arg, 2),
2717 cval1, cval2, save_p));
2720 case tcc_comparison:
2721 /* First see if we can handle the first operand, then the second. For
2722 the second operand, we know *CVAL1 can't be zero. It must be that
2723 one side of the comparison is each of the values; test for the
2724 case where this isn't true by failing if the two operands
2727 if (operand_equal_p (TREE_OPERAND (arg, 0),
2728 TREE_OPERAND (arg, 1), 0))
2732 *cval1 = TREE_OPERAND (arg, 0);
2733 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
2735 else if (*cval2 == 0)
2736 *cval2 = TREE_OPERAND (arg, 0);
2737 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
2742 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
2744 else if (*cval2 == 0)
2745 *cval2 = TREE_OPERAND (arg, 1);
2746 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
2758 /* ARG is a tree that is known to contain just arithmetic operations and
2759 comparisons. Evaluate the operations in the tree substituting NEW0 for
2760 any occurrence of OLD0 as an operand of a comparison and likewise for
2764 eval_subst (tree arg, tree old0, tree new0, tree old1, tree new1)
2766 tree type = TREE_TYPE (arg);
2767 enum tree_code code = TREE_CODE (arg);
2768 enum tree_code_class class = TREE_CODE_CLASS (code);
2770 /* We can handle some of the tcc_expression cases here. */
2771 if (class == tcc_expression && code == TRUTH_NOT_EXPR)
2773 else if (class == tcc_expression
2774 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2780 return fold (build1 (code, type,
2781 eval_subst (TREE_OPERAND (arg, 0),
2782 old0, new0, old1, new1)));
2785 return fold (build2 (code, type,
2786 eval_subst (TREE_OPERAND (arg, 0),
2787 old0, new0, old1, new1),
2788 eval_subst (TREE_OPERAND (arg, 1),
2789 old0, new0, old1, new1)));
2791 case tcc_expression:
2795 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
2798 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
2801 return fold (build3 (code, type,
2802 eval_subst (TREE_OPERAND (arg, 0),
2803 old0, new0, old1, new1),
2804 eval_subst (TREE_OPERAND (arg, 1),
2805 old0, new0, old1, new1),
2806 eval_subst (TREE_OPERAND (arg, 2),
2807 old0, new0, old1, new1)));
2811 /* Fall through - ??? */
2813 case tcc_comparison:
2815 tree arg0 = TREE_OPERAND (arg, 0);
2816 tree arg1 = TREE_OPERAND (arg, 1);
2818 /* We need to check both for exact equality and tree equality. The
2819 former will be true if the operand has a side-effect. In that
2820 case, we know the operand occurred exactly once. */
2822 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
2824 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
2827 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
2829 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
2832 return fold (build2 (code, type, arg0, arg1));
2840 /* Return a tree for the case when the result of an expression is RESULT
2841 converted to TYPE and OMITTED was previously an operand of the expression
2842 but is now not needed (e.g., we folded OMITTED * 0).
2844 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2845 the conversion of RESULT to TYPE. */
2848 omit_one_operand (tree type, tree result, tree omitted)
2850 tree t = fold_convert (type, result);
2852 if (TREE_SIDE_EFFECTS (omitted))
2853 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
2855 return non_lvalue (t);
2858 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2861 pedantic_omit_one_operand (tree type, tree result, tree omitted)
2863 tree t = fold_convert (type, result);
2865 if (TREE_SIDE_EFFECTS (omitted))
2866 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
2868 return pedantic_non_lvalue (t);
2871 /* Return a tree for the case when the result of an expression is RESULT
2872 converted to TYPE and OMITTED1 and OMITTED2 were previously operands
2873 of the expression but are now not needed.
2875 If OMITTED1 or OMITTED2 has side effects, they must be evaluated.
2876 If both OMITTED1 and OMITTED2 have side effects, OMITTED1 is
2877 evaluated before OMITTED2. Otherwise, if neither has side effects,
2878 just do the conversion of RESULT to TYPE. */
2881 omit_two_operands (tree type, tree result, tree omitted1, tree omitted2)
2883 tree t = fold_convert (type, result);
2885 if (TREE_SIDE_EFFECTS (omitted2))
2886 t = build2 (COMPOUND_EXPR, type, omitted2, t);
2887 if (TREE_SIDE_EFFECTS (omitted1))
2888 t = build2 (COMPOUND_EXPR, type, omitted1, t);
2890 return TREE_CODE (t) != COMPOUND_EXPR ? non_lvalue (t) : t;
2894 /* Return a simplified tree node for the truth-negation of ARG. This
2895 never alters ARG itself. We assume that ARG is an operation that
2896 returns a truth value (0 or 1).
2898 FIXME: one would think we would fold the result, but it causes
2899 problems with the dominator optimizer. */
2901 invert_truthvalue (tree arg)
2903 tree type = TREE_TYPE (arg);
2904 enum tree_code code = TREE_CODE (arg);
2906 if (code == ERROR_MARK)
2909 /* If this is a comparison, we can simply invert it, except for
2910 floating-point non-equality comparisons, in which case we just
2911 enclose a TRUTH_NOT_EXPR around what we have. */
2913 if (TREE_CODE_CLASS (code) == tcc_comparison)
2915 tree op_type = TREE_TYPE (TREE_OPERAND (arg, 0));
2916 if (FLOAT_TYPE_P (op_type)
2917 && flag_trapping_math
2918 && code != ORDERED_EXPR && code != UNORDERED_EXPR
2919 && code != NE_EXPR && code != EQ_EXPR)
2920 return build1 (TRUTH_NOT_EXPR, type, arg);
2923 code = invert_tree_comparison (code,
2924 HONOR_NANS (TYPE_MODE (op_type)));
2925 if (code == ERROR_MARK)
2926 return build1 (TRUTH_NOT_EXPR, type, arg);
2928 return build2 (code, type,
2929 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
2936 return fold_convert (type,
2937 build_int_cst (NULL_TREE, integer_zerop (arg)));
2939 case TRUTH_AND_EXPR:
2940 return build2 (TRUTH_OR_EXPR, type,
2941 invert_truthvalue (TREE_OPERAND (arg, 0)),
2942 invert_truthvalue (TREE_OPERAND (arg, 1)));
2945 return build2 (TRUTH_AND_EXPR, type,
2946 invert_truthvalue (TREE_OPERAND (arg, 0)),
2947 invert_truthvalue (TREE_OPERAND (arg, 1)));
2949 case TRUTH_XOR_EXPR:
2950 /* Here we can invert either operand. We invert the first operand
2951 unless the second operand is a TRUTH_NOT_EXPR in which case our
2952 result is the XOR of the first operand with the inside of the
2953 negation of the second operand. */
2955 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
2956 return build2 (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
2957 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
2959 return build2 (TRUTH_XOR_EXPR, type,
2960 invert_truthvalue (TREE_OPERAND (arg, 0)),
2961 TREE_OPERAND (arg, 1));
2963 case TRUTH_ANDIF_EXPR:
2964 return build2 (TRUTH_ORIF_EXPR, type,
2965 invert_truthvalue (TREE_OPERAND (arg, 0)),
2966 invert_truthvalue (TREE_OPERAND (arg, 1)));
2968 case TRUTH_ORIF_EXPR:
2969 return build2 (TRUTH_ANDIF_EXPR, type,
2970 invert_truthvalue (TREE_OPERAND (arg, 0)),
2971 invert_truthvalue (TREE_OPERAND (arg, 1)));
2973 case TRUTH_NOT_EXPR:
2974 return TREE_OPERAND (arg, 0);
2977 return build3 (COND_EXPR, type, TREE_OPERAND (arg, 0),
2978 invert_truthvalue (TREE_OPERAND (arg, 1)),
2979 invert_truthvalue (TREE_OPERAND (arg, 2)));
2982 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
2983 invert_truthvalue (TREE_OPERAND (arg, 1)));
2985 case NON_LVALUE_EXPR:
2986 return invert_truthvalue (TREE_OPERAND (arg, 0));
2989 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE)
2994 return build1 (TREE_CODE (arg), type,
2995 invert_truthvalue (TREE_OPERAND (arg, 0)));
2998 if (!integer_onep (TREE_OPERAND (arg, 1)))
3000 return build2 (EQ_EXPR, type, arg,
3001 fold_convert (type, integer_zero_node));
3004 return build1 (TRUTH_NOT_EXPR, type, arg);
3006 case CLEANUP_POINT_EXPR:
3007 return build1 (CLEANUP_POINT_EXPR, type,
3008 invert_truthvalue (TREE_OPERAND (arg, 0)));
3013 gcc_assert (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE);
3014 return build1 (TRUTH_NOT_EXPR, type, arg);
3017 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
3018 operands are another bit-wise operation with a common input. If so,
3019 distribute the bit operations to save an operation and possibly two if
3020 constants are involved. For example, convert
3021 (A | B) & (A | C) into A | (B & C)
3022 Further simplification will occur if B and C are constants.
3024 If this optimization cannot be done, 0 will be returned. */
3027 distribute_bit_expr (enum tree_code code, tree type, tree arg0, tree arg1)
3032 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3033 || TREE_CODE (arg0) == code
3034 || (TREE_CODE (arg0) != BIT_AND_EXPR
3035 && TREE_CODE (arg0) != BIT_IOR_EXPR))
3038 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
3040 common = TREE_OPERAND (arg0, 0);
3041 left = TREE_OPERAND (arg0, 1);
3042 right = TREE_OPERAND (arg1, 1);
3044 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
3046 common = TREE_OPERAND (arg0, 0);
3047 left = TREE_OPERAND (arg0, 1);
3048 right = TREE_OPERAND (arg1, 0);
3050 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
3052 common = TREE_OPERAND (arg0, 1);
3053 left = TREE_OPERAND (arg0, 0);
3054 right = TREE_OPERAND (arg1, 1);
3056 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
3058 common = TREE_OPERAND (arg0, 1);
3059 left = TREE_OPERAND (arg0, 0);
3060 right = TREE_OPERAND (arg1, 0);
3065 return fold (build2 (TREE_CODE (arg0), type, common,
3066 fold (build2 (code, type, left, right))));
3069 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
3070 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
3073 make_bit_field_ref (tree inner, tree type, int bitsize, int bitpos,
3076 tree result = build3 (BIT_FIELD_REF, type, inner,
3077 size_int (bitsize), bitsize_int (bitpos));
3079 BIT_FIELD_REF_UNSIGNED (result) = unsignedp;
3084 /* Optimize a bit-field compare.
3086 There are two cases: First is a compare against a constant and the
3087 second is a comparison of two items where the fields are at the same
3088 bit position relative to the start of a chunk (byte, halfword, word)
3089 large enough to contain it. In these cases we can avoid the shift
3090 implicit in bitfield extractions.
3092 For constants, we emit a compare of the shifted constant with the
3093 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
3094 compared. For two fields at the same position, we do the ANDs with the
3095 similar mask and compare the result of the ANDs.
3097 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
3098 COMPARE_TYPE is the type of the comparison, and LHS and RHS
3099 are the left and right operands of the comparison, respectively.
3101 If the optimization described above can be done, we return the resulting
3102 tree. Otherwise we return zero. */
3105 optimize_bit_field_compare (enum tree_code code, tree compare_type,
3108 HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
3109 tree type = TREE_TYPE (lhs);
3110 tree signed_type, unsigned_type;
3111 int const_p = TREE_CODE (rhs) == INTEGER_CST;
3112 enum machine_mode lmode, rmode, nmode;
3113 int lunsignedp, runsignedp;
3114 int lvolatilep = 0, rvolatilep = 0;
3115 tree linner, rinner = NULL_TREE;
3119 /* Get all the information about the extractions being done. If the bit size
3120 if the same as the size of the underlying object, we aren't doing an
3121 extraction at all and so can do nothing. We also don't want to
3122 do anything if the inner expression is a PLACEHOLDER_EXPR since we
3123 then will no longer be able to replace it. */
3124 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
3125 &lunsignedp, &lvolatilep, false);
3126 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
3127 || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
3132 /* If this is not a constant, we can only do something if bit positions,
3133 sizes, and signedness are the same. */
3134 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
3135 &runsignedp, &rvolatilep, false);
3137 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
3138 || lunsignedp != runsignedp || offset != 0
3139 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
3143 /* See if we can find a mode to refer to this field. We should be able to,
3144 but fail if we can't. */
3145 nmode = get_best_mode (lbitsize, lbitpos,
3146 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
3147 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
3148 TYPE_ALIGN (TREE_TYPE (rinner))),
3149 word_mode, lvolatilep || rvolatilep);
3150 if (nmode == VOIDmode)
3153 /* Set signed and unsigned types of the precision of this mode for the
3155 signed_type = lang_hooks.types.type_for_mode (nmode, 0);
3156 unsigned_type = lang_hooks.types.type_for_mode (nmode, 1);
3158 /* Compute the bit position and size for the new reference and our offset
3159 within it. If the new reference is the same size as the original, we
3160 won't optimize anything, so return zero. */
3161 nbitsize = GET_MODE_BITSIZE (nmode);
3162 nbitpos = lbitpos & ~ (nbitsize - 1);
3164 if (nbitsize == lbitsize)
3167 if (BYTES_BIG_ENDIAN)
3168 lbitpos = nbitsize - lbitsize - lbitpos;
3170 /* Make the mask to be used against the extracted field. */
3171 mask = build_int_cst (unsigned_type, -1);
3172 mask = force_fit_type (mask, 0, false, false);
3173 mask = fold_convert (unsigned_type, mask);
3174 mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
3175 mask = const_binop (RSHIFT_EXPR, mask,
3176 size_int (nbitsize - lbitsize - lbitpos), 0);
3179 /* If not comparing with constant, just rework the comparison
3181 return build2 (code, compare_type,
3182 build2 (BIT_AND_EXPR, unsigned_type,
3183 make_bit_field_ref (linner, unsigned_type,
3184 nbitsize, nbitpos, 1),
3186 build2 (BIT_AND_EXPR, unsigned_type,
3187 make_bit_field_ref (rinner, unsigned_type,
3188 nbitsize, nbitpos, 1),
3191 /* Otherwise, we are handling the constant case. See if the constant is too
3192 big for the field. Warn and return a tree of for 0 (false) if so. We do
3193 this not only for its own sake, but to avoid having to test for this
3194 error case below. If we didn't, we might generate wrong code.
3196 For unsigned fields, the constant shifted right by the field length should
3197 be all zero. For signed fields, the high-order bits should agree with
3202 if (! integer_zerop (const_binop (RSHIFT_EXPR,
3203 fold_convert (unsigned_type, rhs),
3204 size_int (lbitsize), 0)))
3206 warning ("comparison is always %d due to width of bit-field",
3208 return constant_boolean_node (code == NE_EXPR, compare_type);
3213 tree tem = const_binop (RSHIFT_EXPR, fold_convert (signed_type, rhs),
3214 size_int (lbitsize - 1), 0);
3215 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
3217 warning ("comparison is always %d due to width of bit-field",
3219 return constant_boolean_node (code == NE_EXPR, compare_type);
3223 /* Single-bit compares should always be against zero. */
3224 if (lbitsize == 1 && ! integer_zerop (rhs))
3226 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
3227 rhs = fold_convert (type, integer_zero_node);
3230 /* Make a new bitfield reference, shift the constant over the
3231 appropriate number of bits and mask it with the computed mask
3232 (in case this was a signed field). If we changed it, make a new one. */
3233 lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1);
3236 TREE_SIDE_EFFECTS (lhs) = 1;
3237 TREE_THIS_VOLATILE (lhs) = 1;
3240 rhs = fold (const_binop (BIT_AND_EXPR,
3241 const_binop (LSHIFT_EXPR,
3242 fold_convert (unsigned_type, rhs),
3243 size_int (lbitpos), 0),
3246 return build2 (code, compare_type,
3247 build2 (BIT_AND_EXPR, unsigned_type, lhs, mask),
3251 /* Subroutine for fold_truthop: decode a field reference.
3253 If EXP is a comparison reference, we return the innermost reference.
3255 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
3256 set to the starting bit number.
3258 If the innermost field can be completely contained in a mode-sized
3259 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
3261 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
3262 otherwise it is not changed.
3264 *PUNSIGNEDP is set to the signedness of the field.
3266 *PMASK is set to the mask used. This is either contained in a
3267 BIT_AND_EXPR or derived from the width of the field.
3269 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
3271 Return 0 if this is not a component reference or is one that we can't
3272 do anything with. */
3275 decode_field_reference (tree exp, HOST_WIDE_INT *pbitsize,
3276 HOST_WIDE_INT *pbitpos, enum machine_mode *pmode,
3277 int *punsignedp, int *pvolatilep,
3278 tree *pmask, tree *pand_mask)
3280 tree outer_type = 0;
3282 tree mask, inner, offset;
3284 unsigned int precision;
3286 /* All the optimizations using this function assume integer fields.
3287 There are problems with FP fields since the type_for_size call
3288 below can fail for, e.g., XFmode. */
3289 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
3292 /* We are interested in the bare arrangement of bits, so strip everything
3293 that doesn't affect the machine mode. However, record the type of the
3294 outermost expression if it may matter below. */
3295 if (TREE_CODE (exp) == NOP_EXPR
3296 || TREE_CODE (exp) == CONVERT_EXPR
3297 || TREE_CODE (exp) == NON_LVALUE_EXPR)
3298 outer_type = TREE_TYPE (exp);
3301 if (TREE_CODE (exp) == BIT_AND_EXPR)
3303 and_mask = TREE_OPERAND (exp, 1);
3304 exp = TREE_OPERAND (exp, 0);
3305 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
3306 if (TREE_CODE (and_mask) != INTEGER_CST)
3310 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
3311 punsignedp, pvolatilep, false);
3312 if ((inner == exp && and_mask == 0)
3313 || *pbitsize < 0 || offset != 0
3314 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
3317 /* If the number of bits in the reference is the same as the bitsize of
3318 the outer type, then the outer type gives the signedness. Otherwise
3319 (in case of a small bitfield) the signedness is unchanged. */
3320 if (outer_type && *pbitsize == TYPE_PRECISION (outer_type))
3321 *punsignedp = TYPE_UNSIGNED (outer_type);
3323 /* Compute the mask to access the bitfield. */
3324 unsigned_type = lang_hooks.types.type_for_size (*pbitsize, 1);
3325 precision = TYPE_PRECISION (unsigned_type);
3327 mask = build_int_cst (unsigned_type, -1);
3328 mask = force_fit_type (mask, 0, false, false);
3330 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3331 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3333 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
3335 mask = fold (build2 (BIT_AND_EXPR, unsigned_type,
3336 fold_convert (unsigned_type, and_mask), mask));
3339 *pand_mask = and_mask;
3343 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
3347 all_ones_mask_p (tree mask, int size)
3349 tree type = TREE_TYPE (mask);
3350 unsigned int precision = TYPE_PRECISION (type);
3353 tmask = build_int_cst (lang_hooks.types.signed_type (type), -1);
3354 tmask = force_fit_type (tmask, 0, false, false);
3357 tree_int_cst_equal (mask,
3358 const_binop (RSHIFT_EXPR,
3359 const_binop (LSHIFT_EXPR, tmask,
3360 size_int (precision - size),
3362 size_int (precision - size), 0));
3365 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
3366 represents the sign bit of EXP's type. If EXP represents a sign
3367 or zero extension, also test VAL against the unextended type.
3368 The return value is the (sub)expression whose sign bit is VAL,
3369 or NULL_TREE otherwise. */
3372 sign_bit_p (tree exp, tree val)
3374 unsigned HOST_WIDE_INT mask_lo, lo;
3375 HOST_WIDE_INT mask_hi, hi;
3379 /* Tree EXP must have an integral type. */
3380 t = TREE_TYPE (exp);
3381 if (! INTEGRAL_TYPE_P (t))
3384 /* Tree VAL must be an integer constant. */
3385 if (TREE_CODE (val) != INTEGER_CST
3386 || TREE_CONSTANT_OVERFLOW (val))
3389 width = TYPE_PRECISION (t);
3390 if (width > HOST_BITS_PER_WIDE_INT)
3392 hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1);
3395 mask_hi = ((unsigned HOST_WIDE_INT) -1
3396 >> (2 * HOST_BITS_PER_WIDE_INT - width));
3402 lo = (unsigned HOST_WIDE_INT) 1 << (width - 1);
3405 mask_lo = ((unsigned HOST_WIDE_INT) -1
3406 >> (HOST_BITS_PER_WIDE_INT - width));
3409 /* We mask off those bits beyond TREE_TYPE (exp) so that we can
3410 treat VAL as if it were unsigned. */
3411 if ((TREE_INT_CST_HIGH (val) & mask_hi) == hi
3412 && (TREE_INT_CST_LOW (val) & mask_lo) == lo)
3415 /* Handle extension from a narrower type. */
3416 if (TREE_CODE (exp) == NOP_EXPR
3417 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width)
3418 return sign_bit_p (TREE_OPERAND (exp, 0), val);
3423 /* Subroutine for fold_truthop: determine if an operand is simple enough
3424 to be evaluated unconditionally. */
3427 simple_operand_p (tree exp)
3429 /* Strip any conversions that don't change the machine mode. */
3432 return (CONSTANT_CLASS_P (exp)
3433 || TREE_CODE (exp) == SSA_NAME
3435 && ! TREE_ADDRESSABLE (exp)
3436 && ! TREE_THIS_VOLATILE (exp)
3437 && ! DECL_NONLOCAL (exp)
3438 /* Don't regard global variables as simple. They may be
3439 allocated in ways unknown to the compiler (shared memory,
3440 #pragma weak, etc). */
3441 && ! TREE_PUBLIC (exp)
3442 && ! DECL_EXTERNAL (exp)
3443 /* Loading a static variable is unduly expensive, but global
3444 registers aren't expensive. */
3445 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
3448 /* The following functions are subroutines to fold_range_test and allow it to
3449 try to change a logical combination of comparisons into a range test.
3452 X == 2 || X == 3 || X == 4 || X == 5
3456 (unsigned) (X - 2) <= 3
3458 We describe each set of comparisons as being either inside or outside
3459 a range, using a variable named like IN_P, and then describe the
3460 range with a lower and upper bound. If one of the bounds is omitted,
3461 it represents either the highest or lowest value of the type.
3463 In the comments below, we represent a range by two numbers in brackets
3464 preceded by a "+" to designate being inside that range, or a "-" to
3465 designate being outside that range, so the condition can be inverted by
3466 flipping the prefix. An omitted bound is represented by a "-". For
3467 example, "- [-, 10]" means being outside the range starting at the lowest
3468 possible value and ending at 10, in other words, being greater than 10.
3469 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
3472 We set up things so that the missing bounds are handled in a consistent
3473 manner so neither a missing bound nor "true" and "false" need to be
3474 handled using a special case. */
3476 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
3477 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
3478 and UPPER1_P are nonzero if the respective argument is an upper bound
3479 and zero for a lower. TYPE, if nonzero, is the type of the result; it
3480 must be specified for a comparison. ARG1 will be converted to ARG0's
3481 type if both are specified. */
3484 range_binop (enum tree_code code, tree type, tree arg0, int upper0_p,
3485 tree arg1, int upper1_p)
3491 /* If neither arg represents infinity, do the normal operation.
3492 Else, if not a comparison, return infinity. Else handle the special
3493 comparison rules. Note that most of the cases below won't occur, but
3494 are handled for consistency. */
3496 if (arg0 != 0 && arg1 != 0)
3498 tem = fold (build2 (code, type != 0 ? type : TREE_TYPE (arg0),
3499 arg0, fold_convert (TREE_TYPE (arg0), arg1)));
3501 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
3504 if (TREE_CODE_CLASS (code) != tcc_comparison)
3507 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
3508 for neither. In real maths, we cannot assume open ended ranges are
3509 the same. But, this is computer arithmetic, where numbers are finite.
3510 We can therefore make the transformation of any unbounded range with
3511 the value Z, Z being greater than any representable number. This permits
3512 us to treat unbounded ranges as equal. */
3513 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
3514 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
3518 result = sgn0 == sgn1;
3521 result = sgn0 != sgn1;
3524 result = sgn0 < sgn1;
3527 result = sgn0 <= sgn1;
3530 result = sgn0 > sgn1;
3533 result = sgn0 >= sgn1;
3539 return constant_boolean_node (result, type);
3542 /* Given EXP, a logical expression, set the range it is testing into
3543 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
3544 actually being tested. *PLOW and *PHIGH will be made of the same type
3545 as the returned expression. If EXP is not a comparison, we will most
3546 likely not be returning a useful value and range. */
3549 make_range (tree exp, int *pin_p, tree *plow, tree *phigh)
3551 enum tree_code code;
3552 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
3553 tree exp_type = NULL_TREE, arg0_type = NULL_TREE;
3555 tree low, high, n_low, n_high;
3557 /* Start with simply saying "EXP != 0" and then look at the code of EXP
3558 and see if we can refine the range. Some of the cases below may not
3559 happen, but it doesn't seem worth worrying about this. We "continue"
3560 the outer loop when we've changed something; otherwise we "break"
3561 the switch, which will "break" the while. */
3564 low = high = fold_convert (TREE_TYPE (exp), integer_zero_node);
3568 code = TREE_CODE (exp);
3569 exp_type = TREE_TYPE (exp);
3571 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
3573 if (TREE_CODE_LENGTH (code) > 0)
3574 arg0 = TREE_OPERAND (exp, 0);
3575 if (TREE_CODE_CLASS (code) == tcc_comparison
3576 || TREE_CODE_CLASS (code) == tcc_unary
3577 || TREE_CODE_CLASS (code) == tcc_binary)
3578 arg0_type = TREE_TYPE (arg0);
3579 if (TREE_CODE_CLASS (code) == tcc_binary
3580 || TREE_CODE_CLASS (code) == tcc_comparison
3581 || (TREE_CODE_CLASS (code) == tcc_expression
3582 && TREE_CODE_LENGTH (code) > 1))
3583 arg1 = TREE_OPERAND (exp, 1);
3588 case TRUTH_NOT_EXPR:
3589 in_p = ! in_p, exp = arg0;
3592 case EQ_EXPR: case NE_EXPR:
3593 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
3594 /* We can only do something if the range is testing for zero
3595 and if the second operand is an integer constant. Note that
3596 saying something is "in" the range we make is done by
3597 complementing IN_P since it will set in the initial case of
3598 being not equal to zero; "out" is leaving it alone. */
3599 if (low == 0 || high == 0
3600 || ! integer_zerop (low) || ! integer_zerop (high)
3601 || TREE_CODE (arg1) != INTEGER_CST)
3606 case NE_EXPR: /* - [c, c] */
3609 case EQ_EXPR: /* + [c, c] */
3610 in_p = ! in_p, low = high = arg1;
3612 case GT_EXPR: /* - [-, c] */
3613 low = 0, high = arg1;
3615 case GE_EXPR: /* + [c, -] */
3616 in_p = ! in_p, low = arg1, high = 0;
3618 case LT_EXPR: /* - [c, -] */
3619 low = arg1, high = 0;
3621 case LE_EXPR: /* + [-, c] */
3622 in_p = ! in_p, low = 0, high = arg1;
3628 /* If this is an unsigned comparison, we also know that EXP is
3629 greater than or equal to zero. We base the range tests we make
3630 on that fact, so we record it here so we can parse existing
3631 range tests. We test arg0_type since often the return type
3632 of, e.g. EQ_EXPR, is boolean. */
3633 if (TYPE_UNSIGNED (arg0_type) && (low == 0 || high == 0))
3635 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3637 fold_convert (arg0_type, integer_zero_node),
3641 in_p = n_in_p, low = n_low, high = n_high;
3643 /* If the high bound is missing, but we have a nonzero low
3644 bound, reverse the range so it goes from zero to the low bound
3646 if (high == 0 && low && ! integer_zerop (low))
3649 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
3650 integer_one_node, 0);
3651 low = fold_convert (arg0_type, integer_zero_node);
3659 /* (-x) IN [a,b] -> x in [-b, -a] */
3660 n_low = range_binop (MINUS_EXPR, exp_type,
3661 fold_convert (exp_type, integer_zero_node),
3663 n_high = range_binop (MINUS_EXPR, exp_type,
3664 fold_convert (exp_type, integer_zero_node),
3666 low = n_low, high = n_high;
3672 exp = build2 (MINUS_EXPR, exp_type, negate_expr (arg0),
3673 fold_convert (exp_type, integer_one_node));
3676 case PLUS_EXPR: case MINUS_EXPR:
3677 if (TREE_CODE (arg1) != INTEGER_CST)
3680 /* If EXP is signed, any overflow in the computation is undefined,
3681 so we don't worry about it so long as our computations on
3682 the bounds don't overflow. For unsigned, overflow is defined
3683 and this is exactly the right thing. */
3684 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3685 arg0_type, low, 0, arg1, 0);
3686 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3687 arg0_type, high, 1, arg1, 0);
3688 if ((n_low != 0 && TREE_OVERFLOW (n_low))
3689 || (n_high != 0 && TREE_OVERFLOW (n_high)))
3692 /* Check for an unsigned range which has wrapped around the maximum
3693 value thus making n_high < n_low, and normalize it. */
3694 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
3696 low = range_binop (PLUS_EXPR, arg0_type, n_high, 0,
3697 integer_one_node, 0);
3698 high = range_binop (MINUS_EXPR, arg0_type, n_low, 0,
3699 integer_one_node, 0);
3701 /* If the range is of the form +/- [ x+1, x ], we won't
3702 be able to normalize it. But then, it represents the
3703 whole range or the empty set, so make it
3705 if (tree_int_cst_equal (n_low, low)
3706 && tree_int_cst_equal (n_high, high))
3712 low = n_low, high = n_high;
3717 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
3718 if (TYPE_PRECISION (arg0_type) > TYPE_PRECISION (exp_type))
3721 if (! INTEGRAL_TYPE_P (arg0_type)
3722 || (low != 0 && ! int_fits_type_p (low, arg0_type))
3723 || (high != 0 && ! int_fits_type_p (high, arg0_type)))
3726 n_low = low, n_high = high;
3729 n_low = fold_convert (arg0_type, n_low);
3732 n_high = fold_convert (arg0_type, n_high);
3735 /* If we're converting arg0 from an unsigned type, to exp,
3736 a signed type, we will be doing the comparison as unsigned.
3737 The tests above have already verified that LOW and HIGH
3740 So we have to ensure that we will handle large unsigned
3741 values the same way that the current signed bounds treat
3744 if (!TYPE_UNSIGNED (exp_type) && TYPE_UNSIGNED (arg0_type))
3747 tree equiv_type = lang_hooks.types.type_for_mode
3748 (TYPE_MODE (arg0_type), 1);
3750 /* A range without an upper bound is, naturally, unbounded.
3751 Since convert would have cropped a very large value, use
3752 the max value for the destination type. */
3754 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
3755 : TYPE_MAX_VALUE (arg0_type);
3757 if (TYPE_PRECISION (exp_type) == TYPE_PRECISION (arg0_type))
3758 high_positive = fold (build2 (RSHIFT_EXPR, arg0_type,
3759 fold_convert (arg0_type,
3761 fold_convert (arg0_type,
3762 integer_one_node)));
3764 /* If the low bound is specified, "and" the range with the
3765 range for which the original unsigned value will be
3769 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3770 1, n_low, n_high, 1,
3771 fold_convert (arg0_type,
3776 in_p = (n_in_p == in_p);
3780 /* Otherwise, "or" the range with the range of the input
3781 that will be interpreted as negative. */
3782 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3783 0, n_low, n_high, 1,
3784 fold_convert (arg0_type,
3789 in_p = (in_p != n_in_p);
3794 low = n_low, high = n_high;
3804 /* If EXP is a constant, we can evaluate whether this is true or false. */
3805 if (TREE_CODE (exp) == INTEGER_CST)
3807 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
3809 && integer_onep (range_binop (LE_EXPR, integer_type_node,
3815 *pin_p = in_p, *plow = low, *phigh = high;
3819 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3820 type, TYPE, return an expression to test if EXP is in (or out of, depending
3821 on IN_P) the range. Return 0 if the test couldn't be created. */
3824 build_range_check (tree type, tree exp, int in_p, tree low, tree high)
3826 tree etype = TREE_TYPE (exp);
3831 value = build_range_check (type, exp, 1, low, high);
3833 return invert_truthvalue (value);
3838 if (low == 0 && high == 0)
3839 return fold_convert (type, integer_one_node);
3842 return fold (build2 (LE_EXPR, type, exp, high));
3845 return fold (build2 (GE_EXPR, type, exp, low));
3847 if (operand_equal_p (low, high, 0))
3848 return fold (build2 (EQ_EXPR, type, exp, low));
3850 if (integer_zerop (low))
3852 if (! TYPE_UNSIGNED (etype))
3854 etype = lang_hooks.types.unsigned_type (etype);
3855 high = fold_convert (etype, high);
3856 exp = fold_convert (etype, exp);
3858 return build_range_check (type, exp, 1, 0, high);
3861 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
3862 if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST)
3864 unsigned HOST_WIDE_INT lo;
3868 prec = TYPE_PRECISION (etype);
3869 if (prec <= HOST_BITS_PER_WIDE_INT)
3872 lo = ((unsigned HOST_WIDE_INT) 1 << (prec - 1)) - 1;
3876 hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1;
3877 lo = (unsigned HOST_WIDE_INT) -1;
3880 if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo)
3882 if (TYPE_UNSIGNED (etype))
3884 etype = lang_hooks.types.signed_type (etype);
3885 exp = fold_convert (etype, exp);
3887 return fold (build2 (GT_EXPR, type, exp,
3888 fold_convert (etype, integer_zero_node)));
3892 value = const_binop (MINUS_EXPR, high, low, 0);
3893 if (value != 0 && TREE_OVERFLOW (value) && ! TYPE_UNSIGNED (etype))
3895 tree utype, minv, maxv;
3897 /* Check if (unsigned) INT_MAX + 1 == (unsigned) INT_MIN
3898 for the type in question, as we rely on this here. */
3899 switch (TREE_CODE (etype))
3904 utype = lang_hooks.types.unsigned_type (etype);
3905 maxv = fold_convert (utype, TYPE_MAX_VALUE (etype));
3906 maxv = range_binop (PLUS_EXPR, NULL_TREE, maxv, 1,
3907 integer_one_node, 1);
3908 minv = fold_convert (utype, TYPE_MIN_VALUE (etype));
3909 if (integer_zerop (range_binop (NE_EXPR, integer_type_node,
3913 high = fold_convert (etype, high);
3914 low = fold_convert (etype, low);
3915 exp = fold_convert (etype, exp);
3916 value = const_binop (MINUS_EXPR, high, low, 0);
3924 if (value != 0 && ! TREE_OVERFLOW (value))
3925 return build_range_check (type,
3926 fold (build2 (MINUS_EXPR, etype, exp, low)),
3927 1, fold_convert (etype, integer_zero_node),
3933 /* Given two ranges, see if we can merge them into one. Return 1 if we
3934 can, 0 if we can't. Set the output range into the specified parameters. */
3937 merge_ranges (int *pin_p, tree *plow, tree *phigh, int in0_p, tree low0,
3938 tree high0, int in1_p, tree low1, tree high1)
3946 int lowequal = ((low0 == 0 && low1 == 0)
3947 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3948 low0, 0, low1, 0)));
3949 int highequal = ((high0 == 0 && high1 == 0)
3950 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3951 high0, 1, high1, 1)));
3953 /* Make range 0 be the range that starts first, or ends last if they
3954 start at the same value. Swap them if it isn't. */
3955 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
3958 && integer_onep (range_binop (GT_EXPR, integer_type_node,
3959 high1, 1, high0, 1))))
3961 temp = in0_p, in0_p = in1_p, in1_p = temp;
3962 tem = low0, low0 = low1, low1 = tem;
3963 tem = high0, high0 = high1, high1 = tem;
3966 /* Now flag two cases, whether the ranges are disjoint or whether the
3967 second range is totally subsumed in the first. Note that the tests
3968 below are simplified by the ones above. */
3969 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
3970 high0, 1, low1, 0));
3971 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
3972 high1, 1, high0, 1));
3974 /* We now have four cases, depending on whether we are including or
3975 excluding the two ranges. */
3978 /* If they don't overlap, the result is false. If the second range
3979 is a subset it is the result. Otherwise, the range is from the start
3980 of the second to the end of the first. */
3982 in_p = 0, low = high = 0;
3984 in_p = 1, low = low1, high = high1;
3986 in_p = 1, low = low1, high = high0;
3989 else if (in0_p && ! in1_p)
3991 /* If they don't overlap, the result is the first range. If they are
3992 equal, the result is false. If the second range is a subset of the
3993 first, and the ranges begin at the same place, we go from just after
3994 the end of the first range to the end of the second. If the second
3995 range is not a subset of the first, or if it is a subset and both
3996 ranges end at the same place, the range starts at the start of the
3997 first range and ends just before the second range.
3998 Otherwise, we can't describe this as a single range. */
4000 in_p = 1, low = low0, high = high0;
4001 else if (lowequal && highequal)
4002 in_p = 0, low = high = 0;
4003 else if (subset && lowequal)
4005 in_p = 1, high = high0;
4006 low = range_binop (PLUS_EXPR, NULL_TREE, high1, 0,
4007 integer_one_node, 0);
4009 else if (! subset || highequal)
4011 in_p = 1, low = low0;
4012 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
4013 integer_one_node, 0);
4019 else if (! in0_p && in1_p)
4021 /* If they don't overlap, the result is the second range. If the second
4022 is a subset of the first, the result is false. Otherwise,
4023 the range starts just after the first range and ends at the
4024 end of the second. */
4026 in_p = 1, low = low1, high = high1;
4027 else if (subset || highequal)
4028 in_p = 0, low = high = 0;
4031 in_p = 1, high = high1;
4032 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
4033 integer_one_node, 0);
4039 /* The case where we are excluding both ranges. Here the complex case
4040 is if they don't overlap. In that case, the only time we have a
4041 range is if they are adjacent. If the second is a subset of the
4042 first, the result is the first. Otherwise, the range to exclude
4043 starts at the beginning of the first range and ends at the end of the
4047 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
4048 range_binop (PLUS_EXPR, NULL_TREE,
4050 integer_one_node, 1),
4052 in_p = 0, low = low0, high = high1;
4055 /* Canonicalize - [min, x] into - [-, x]. */
4056 if (low0 && TREE_CODE (low0) == INTEGER_CST)
4057 switch (TREE_CODE (TREE_TYPE (low0)))
4060 if (TYPE_PRECISION (TREE_TYPE (low0))
4061 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (low0))))
4066 if (tree_int_cst_equal (low0,
4067 TYPE_MIN_VALUE (TREE_TYPE (low0))))
4071 if (TYPE_UNSIGNED (TREE_TYPE (low0))
4072 && integer_zerop (low0))
4079 /* Canonicalize - [x, max] into - [x, -]. */
4080 if (high1 && TREE_CODE (high1) == INTEGER_CST)
4081 switch (TREE_CODE (TREE_TYPE (high1)))
4084 if (TYPE_PRECISION (TREE_TYPE (high1))
4085 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (high1))))
4090 if (tree_int_cst_equal (high1,
4091 TYPE_MAX_VALUE (TREE_TYPE (high1))))
4095 if (TYPE_UNSIGNED (TREE_TYPE (high1))
4096 && integer_zerop (range_binop (PLUS_EXPR, NULL_TREE,
4098 integer_one_node, 1)))
4105 /* The ranges might be also adjacent between the maximum and
4106 minimum values of the given type. For
4107 - [{min,-}, x] and - [y, {max,-}] ranges where x + 1 < y
4108 return + [x + 1, y - 1]. */
4109 if (low0 == 0 && high1 == 0)
4111 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
4112 integer_one_node, 1);
4113 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
4114 integer_one_node, 0);
4115 if (low == 0 || high == 0)
4125 in_p = 0, low = low0, high = high0;
4127 in_p = 0, low = low0, high = high1;
4130 *pin_p = in_p, *plow = low, *phigh = high;
4135 /* Subroutine of fold, looking inside expressions of the form
4136 A op B ? A : C, where ARG0, ARG1 and ARG2 are the three operands
4137 of the COND_EXPR. This function is being used also to optimize
4138 A op B ? C : A, by reversing the comparison first.
4140 Return a folded expression whose code is not a COND_EXPR
4141 anymore, or NULL_TREE if no folding opportunity is found. */
4144 fold_cond_expr_with_comparison (tree type, tree arg0, tree arg1, tree arg2)
4146 enum tree_code comp_code = TREE_CODE (arg0);
4147 tree arg00 = TREE_OPERAND (arg0, 0);
4148 tree arg01 = TREE_OPERAND (arg0, 1);
4149 tree arg1_type = TREE_TYPE (arg1);
4155 /* If we have A op 0 ? A : -A, consider applying the following
4158 A == 0? A : -A same as -A
4159 A != 0? A : -A same as A
4160 A >= 0? A : -A same as abs (A)
4161 A > 0? A : -A same as abs (A)
4162 A <= 0? A : -A same as -abs (A)
4163 A < 0? A : -A same as -abs (A)
4165 None of these transformations work for modes with signed
4166 zeros. If A is +/-0, the first two transformations will
4167 change the sign of the result (from +0 to -0, or vice
4168 versa). The last four will fix the sign of the result,
4169 even though the original expressions could be positive or
4170 negative, depending on the sign of A.
4172 Note that all these transformations are correct if A is
4173 NaN, since the two alternatives (A and -A) are also NaNs. */
4174 if ((FLOAT_TYPE_P (TREE_TYPE (arg01))
4175 ? real_zerop (arg01)
4176 : integer_zerop (arg01))
4177 && TREE_CODE (arg2) == NEGATE_EXPR
4178 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
4183 tem = fold_convert (arg1_type, arg1);
4184 return pedantic_non_lvalue (fold_convert (type, negate_expr (tem)));
4187 return pedantic_non_lvalue (fold_convert (type, arg1));
4190 if (flag_trapping_math)
4195 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
4196 arg1 = fold_convert (lang_hooks.types.signed_type
4197 (TREE_TYPE (arg1)), arg1);
4198 tem = fold (build1 (ABS_EXPR, TREE_TYPE (arg1), arg1));
4199 return pedantic_non_lvalue (fold_convert (type, tem));
4202 if (flag_trapping_math)
4206 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
4207 arg1 = fold_convert (lang_hooks.types.signed_type
4208 (TREE_TYPE (arg1)), arg1);
4209 tem = fold (build1 (ABS_EXPR, TREE_TYPE (arg1), arg1));
4210 return negate_expr (fold_convert (type, tem));
4212 gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
4216 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
4217 A == 0 ? A : 0 is always 0 unless A is -0. Note that
4218 both transformations are correct when A is NaN: A != 0
4219 is then true, and A == 0 is false. */
4221 if (integer_zerop (arg01) && integer_zerop (arg2))
4223 if (comp_code == NE_EXPR)
4224 return pedantic_non_lvalue (fold_convert (type, arg1));
4225 else if (comp_code == EQ_EXPR)
4226 return fold_convert (type, integer_zero_node);
4229 /* Try some transformations of A op B ? A : B.
4231 A == B? A : B same as B
4232 A != B? A : B same as A
4233 A >= B? A : B same as max (A, B)
4234 A > B? A : B same as max (B, A)
4235 A <= B? A : B same as min (A, B)
4236 A < B? A : B same as min (B, A)
4238 As above, these transformations don't work in the presence
4239 of signed zeros. For example, if A and B are zeros of
4240 opposite sign, the first two transformations will change
4241 the sign of the result. In the last four, the original
4242 expressions give different results for (A=+0, B=-0) and
4243 (A=-0, B=+0), but the transformed expressions do not.
4245 The first two transformations are correct if either A or B
4246 is a NaN. In the first transformation, the condition will
4247 be false, and B will indeed be chosen. In the case of the
4248 second transformation, the condition A != B will be true,
4249 and A will be chosen.
4251 The conversions to max() and min() are not correct if B is
4252 a number and A is not. The conditions in the original
4253 expressions will be false, so all four give B. The min()
4254 and max() versions would give a NaN instead. */
4255 if (operand_equal_for_comparison_p (arg01, arg2, arg00))
4257 tree comp_op0 = arg00;
4258 tree comp_op1 = arg01;
4259 tree comp_type = TREE_TYPE (comp_op0);
4261 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
4262 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
4272 return pedantic_non_lvalue (fold_convert (type, arg2));
4274 return pedantic_non_lvalue (fold_convert (type, arg1));
4279 /* In C++ a ?: expression can be an lvalue, so put the
4280 operand which will be used if they are equal first
4281 so that we can convert this back to the
4282 corresponding COND_EXPR. */
4283 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4285 comp_op0 = fold_convert (comp_type, comp_op0);
4286 comp_op1 = fold_convert (comp_type, comp_op1);
4287 tem = (comp_code == LE_EXPR || comp_code == UNLE_EXPR)
4288 ? fold (build2 (MIN_EXPR, comp_type, comp_op0, comp_op1))
4289 : fold (build2 (MIN_EXPR, comp_type, comp_op1, comp_op0));
4290 return pedantic_non_lvalue (fold_convert (type, tem));
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 == GE_EXPR || comp_code == UNGE_EXPR)
4302 ? fold (build2 (MAX_EXPR, comp_type, comp_op0, comp_op1))
4303 : fold (build2 (MAX_EXPR, comp_type, comp_op1, comp_op0));
4304 return pedantic_non_lvalue (fold_convert (type, tem));
4308 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4309 return pedantic_non_lvalue (fold_convert (type, arg2));
4312 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4313 return pedantic_non_lvalue (fold_convert (type, arg1));
4316 gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
4321 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
4322 we might still be able to simplify this. For example,
4323 if C1 is one less or one more than C2, this might have started
4324 out as a MIN or MAX and been transformed by this function.
4325 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
4327 if (INTEGRAL_TYPE_P (type)
4328 && TREE_CODE (arg01) == INTEGER_CST
4329 && TREE_CODE (arg2) == INTEGER_CST)
4333 /* We can replace A with C1 in this case. */
4334 arg1 = fold_convert (type, arg01);
4335 return fold (build3 (COND_EXPR, type, arg0, arg1, arg2));
4338 /* If C1 is C2 + 1, this is min(A, C2). */
4339 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
4341 && operand_equal_p (arg01,
4342 const_binop (PLUS_EXPR, arg2,
4343 integer_one_node, 0),
4345 return pedantic_non_lvalue (fold (build2 (MIN_EXPR,
4346 type, arg1, arg2)));
4350 /* If C1 is C2 - 1, this is min(A, C2). */
4351 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
4353 && operand_equal_p (arg01,
4354 const_binop (MINUS_EXPR, arg2,
4355 integer_one_node, 0),
4357 return pedantic_non_lvalue (fold (build2 (MIN_EXPR,
4358 type, arg1, arg2)));
4362 /* If C1 is C2 - 1, this is max(A, C2). */
4363 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
4365 && operand_equal_p (arg01,
4366 const_binop (MINUS_EXPR, arg2,
4367 integer_one_node, 0),
4369 return pedantic_non_lvalue (fold (build2 (MAX_EXPR,
4370 type, arg1, arg2)));
4374 /* If C1 is C2 + 1, this is max(A, C2). */
4375 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
4377 && operand_equal_p (arg01,
4378 const_binop (PLUS_EXPR, arg2,
4379 integer_one_node, 0),
4381 return pedantic_non_lvalue (fold (build2 (MAX_EXPR,
4382 type, arg1, arg2)));
4395 #ifndef LOGICAL_OP_NON_SHORT_CIRCUIT
4396 #define LOGICAL_OP_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
4399 /* EXP is some logical combination of boolean tests. See if we can
4400 merge it into some range test. Return the new tree if so. */
4403 fold_range_test (tree exp)
4405 int or_op = (TREE_CODE (exp) == TRUTH_ORIF_EXPR
4406 || TREE_CODE (exp) == TRUTH_OR_EXPR);
4407 int in0_p, in1_p, in_p;
4408 tree low0, low1, low, high0, high1, high;
4409 tree lhs = make_range (TREE_OPERAND (exp, 0), &in0_p, &low0, &high0);
4410 tree rhs = make_range (TREE_OPERAND (exp, 1), &in1_p, &low1, &high1);
4413 /* If this is an OR operation, invert both sides; we will invert
4414 again at the end. */
4416 in0_p = ! in0_p, in1_p = ! in1_p;
4418 /* If both expressions are the same, if we can merge the ranges, and we
4419 can build the range test, return it or it inverted. If one of the
4420 ranges is always true or always false, consider it to be the same
4421 expression as the other. */
4422 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
4423 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
4425 && 0 != (tem = (build_range_check (TREE_TYPE (exp),
4427 : rhs != 0 ? rhs : integer_zero_node,
4429 return or_op ? invert_truthvalue (tem) : tem;
4431 /* On machines where the branch cost is expensive, if this is a
4432 short-circuited branch and the underlying object on both sides
4433 is the same, make a non-short-circuit operation. */
4434 else if (LOGICAL_OP_NON_SHORT_CIRCUIT
4435 && lhs != 0 && rhs != 0
4436 && (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
4437 || TREE_CODE (exp) == TRUTH_ORIF_EXPR)
4438 && operand_equal_p (lhs, rhs, 0))
4440 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
4441 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
4442 which cases we can't do this. */
4443 if (simple_operand_p (lhs))
4444 return build2 (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
4445 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
4446 TREE_TYPE (exp), TREE_OPERAND (exp, 0),
4447 TREE_OPERAND (exp, 1));
4449 else if (lang_hooks.decls.global_bindings_p () == 0
4450 && ! CONTAINS_PLACEHOLDER_P (lhs))
4452 tree common = save_expr (lhs);
4454 if (0 != (lhs = build_range_check (TREE_TYPE (exp), common,
4455 or_op ? ! in0_p : in0_p,
4457 && (0 != (rhs = build_range_check (TREE_TYPE (exp), common,
4458 or_op ? ! in1_p : in1_p,
4460 return build2 (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
4461 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
4462 TREE_TYPE (exp), lhs, rhs);
4469 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
4470 bit value. Arrange things so the extra bits will be set to zero if and
4471 only if C is signed-extended to its full width. If MASK is nonzero,
4472 it is an INTEGER_CST that should be AND'ed with the extra bits. */
4475 unextend (tree c, int p, int unsignedp, tree mask)
4477 tree type = TREE_TYPE (c);
4478 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
4481 if (p == modesize || unsignedp)
4484 /* We work by getting just the sign bit into the low-order bit, then
4485 into the high-order bit, then sign-extend. We then XOR that value
4487 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
4488 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
4490 /* We must use a signed type in order to get an arithmetic right shift.
4491 However, we must also avoid introducing accidental overflows, so that
4492 a subsequent call to integer_zerop will work. Hence we must
4493 do the type conversion here. At this point, the constant is either
4494 zero or one, and the conversion to a signed type can never overflow.
4495 We could get an overflow if this conversion is done anywhere else. */
4496 if (TYPE_UNSIGNED (type))
4497 temp = fold_convert (lang_hooks.types.signed_type (type), temp);
4499 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
4500 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
4502 temp = const_binop (BIT_AND_EXPR, temp,
4503 fold_convert (TREE_TYPE (c), mask), 0);
4504 /* If necessary, convert the type back to match the type of C. */
4505 if (TYPE_UNSIGNED (type))
4506 temp = fold_convert (type, temp);
4508 return fold_convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
4511 /* Find ways of folding logical expressions of LHS and RHS:
4512 Try to merge two comparisons to the same innermost item.
4513 Look for range tests like "ch >= '0' && ch <= '9'".
4514 Look for combinations of simple terms on machines with expensive branches
4515 and evaluate the RHS unconditionally.
4517 For example, if we have p->a == 2 && p->b == 4 and we can make an
4518 object large enough to span both A and B, we can do this with a comparison
4519 against the object ANDed with the a mask.
4521 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
4522 operations to do this with one comparison.
4524 We check for both normal comparisons and the BIT_AND_EXPRs made this by
4525 function and the one above.
4527 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
4528 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
4530 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
4533 We return the simplified tree or 0 if no optimization is possible. */
4536 fold_truthop (enum tree_code code, tree truth_type, tree lhs, tree rhs)
4538 /* If this is the "or" of two comparisons, we can do something if
4539 the comparisons are NE_EXPR. If this is the "and", we can do something
4540 if the comparisons are EQ_EXPR. I.e.,
4541 (a->b == 2 && a->c == 4) can become (a->new == NEW).
4543 WANTED_CODE is this operation code. For single bit fields, we can
4544 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
4545 comparison for one-bit fields. */
4547 enum tree_code wanted_code;
4548 enum tree_code lcode, rcode;
4549 tree ll_arg, lr_arg, rl_arg, rr_arg;
4550 tree ll_inner, lr_inner, rl_inner, rr_inner;
4551 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
4552 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
4553 HOST_WIDE_INT xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
4554 HOST_WIDE_INT lnbitsize, lnbitpos, rnbitsize, rnbitpos;
4555 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
4556 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
4557 enum machine_mode lnmode, rnmode;
4558 tree ll_mask, lr_mask, rl_mask, rr_mask;
4559 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
4560 tree l_const, r_const;
4561 tree lntype, rntype, result;
4562 int first_bit, end_bit;
4565 /* Start by getting the comparison codes. Fail if anything is volatile.
4566 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
4567 it were surrounded with a NE_EXPR. */
4569 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
4572 lcode = TREE_CODE (lhs);
4573 rcode = TREE_CODE (rhs);
4575 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
4577 lhs = build2 (NE_EXPR, truth_type, lhs,
4578 fold_convert (TREE_TYPE (lhs), integer_zero_node));
4582 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
4584 rhs = build2 (NE_EXPR, truth_type, rhs,
4585 fold_convert (TREE_TYPE (rhs), integer_zero_node));
4589 if (TREE_CODE_CLASS (lcode) != tcc_comparison
4590 || TREE_CODE_CLASS (rcode) != tcc_comparison)
4593 ll_arg = TREE_OPERAND (lhs, 0);
4594 lr_arg = TREE_OPERAND (lhs, 1);
4595 rl_arg = TREE_OPERAND (rhs, 0);
4596 rr_arg = TREE_OPERAND (rhs, 1);
4598 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
4599 if (simple_operand_p (ll_arg)
4600 && simple_operand_p (lr_arg))
4603 if (operand_equal_p (ll_arg, rl_arg, 0)
4604 && operand_equal_p (lr_arg, rr_arg, 0))
4606 result = combine_comparisons (code, lcode, rcode,
4607 truth_type, ll_arg, lr_arg);
4611 else if (operand_equal_p (ll_arg, rr_arg, 0)
4612 && operand_equal_p (lr_arg, rl_arg, 0))
4614 result = combine_comparisons (code, lcode,
4615 swap_tree_comparison (rcode),
4616 truth_type, ll_arg, lr_arg);
4622 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
4623 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
4625 /* If the RHS can be evaluated unconditionally and its operands are
4626 simple, it wins to evaluate the RHS unconditionally on machines
4627 with expensive branches. In this case, this isn't a comparison
4628 that can be merged. Avoid doing this if the RHS is a floating-point
4629 comparison since those can trap. */
4631 if (BRANCH_COST >= 2
4632 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
4633 && simple_operand_p (rl_arg)
4634 && simple_operand_p (rr_arg))
4636 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
4637 if (code == TRUTH_OR_EXPR
4638 && lcode == NE_EXPR && integer_zerop (lr_arg)
4639 && rcode == NE_EXPR && integer_zerop (rr_arg)
4640 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
4641 return build2 (NE_EXPR, truth_type,
4642 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
4644 fold_convert (TREE_TYPE (ll_arg), integer_zero_node));
4646 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
4647 if (code == TRUTH_AND_EXPR
4648 && lcode == EQ_EXPR && integer_zerop (lr_arg)
4649 && rcode == EQ_EXPR && integer_zerop (rr_arg)
4650 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
4651 return build2 (EQ_EXPR, truth_type,
4652 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
4654 fold_convert (TREE_TYPE (ll_arg), integer_zero_node));
4656 if (LOGICAL_OP_NON_SHORT_CIRCUIT)
4657 return build2 (code, truth_type, lhs, rhs);
4660 /* See if the comparisons can be merged. Then get all the parameters for
4663 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
4664 || (rcode != EQ_EXPR && rcode != NE_EXPR))
4668 ll_inner = decode_field_reference (ll_arg,
4669 &ll_bitsize, &ll_bitpos, &ll_mode,
4670 &ll_unsignedp, &volatilep, &ll_mask,
4672 lr_inner = decode_field_reference (lr_arg,
4673 &lr_bitsize, &lr_bitpos, &lr_mode,
4674 &lr_unsignedp, &volatilep, &lr_mask,
4676 rl_inner = decode_field_reference (rl_arg,
4677 &rl_bitsize, &rl_bitpos, &rl_mode,
4678 &rl_unsignedp, &volatilep, &rl_mask,
4680 rr_inner = decode_field_reference (rr_arg,
4681 &rr_bitsize, &rr_bitpos, &rr_mode,
4682 &rr_unsignedp, &volatilep, &rr_mask,
4685 /* It must be true that the inner operation on the lhs of each
4686 comparison must be the same if we are to be able to do anything.
4687 Then see if we have constants. If not, the same must be true for
4689 if (volatilep || ll_inner == 0 || rl_inner == 0
4690 || ! operand_equal_p (ll_inner, rl_inner, 0))
4693 if (TREE_CODE (lr_arg) == INTEGER_CST
4694 && TREE_CODE (rr_arg) == INTEGER_CST)
4695 l_const = lr_arg, r_const = rr_arg;
4696 else if (lr_inner == 0 || rr_inner == 0
4697 || ! operand_equal_p (lr_inner, rr_inner, 0))
4700 l_const = r_const = 0;
4702 /* If either comparison code is not correct for our logical operation,
4703 fail. However, we can convert a one-bit comparison against zero into
4704 the opposite comparison against that bit being set in the field. */
4706 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
4707 if (lcode != wanted_code)
4709 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
4711 /* Make the left operand unsigned, since we are only interested
4712 in the value of one bit. Otherwise we are doing the wrong
4721 /* This is analogous to the code for l_const above. */
4722 if (rcode != wanted_code)
4724 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
4733 /* After this point all optimizations will generate bit-field
4734 references, which we might not want. */
4735 if (! lang_hooks.can_use_bit_fields_p ())
4738 /* See if we can find a mode that contains both fields being compared on
4739 the left. If we can't, fail. Otherwise, update all constants and masks
4740 to be relative to a field of that size. */
4741 first_bit = MIN (ll_bitpos, rl_bitpos);
4742 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
4743 lnmode = get_best_mode (end_bit - first_bit, first_bit,
4744 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
4746 if (lnmode == VOIDmode)
4749 lnbitsize = GET_MODE_BITSIZE (lnmode);
4750 lnbitpos = first_bit & ~ (lnbitsize - 1);
4751 lntype = lang_hooks.types.type_for_size (lnbitsize, 1);
4752 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
4754 if (BYTES_BIG_ENDIAN)
4756 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
4757 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
4760 ll_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, ll_mask),
4761 size_int (xll_bitpos), 0);
4762 rl_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, rl_mask),
4763 size_int (xrl_bitpos), 0);
4767 l_const = fold_convert (lntype, l_const);
4768 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
4769 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
4770 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
4771 fold (build1 (BIT_NOT_EXPR,
4775 warning ("comparison is always %d", wanted_code == NE_EXPR);
4777 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
4782 r_const = fold_convert (lntype, r_const);
4783 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
4784 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
4785 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
4786 fold (build1 (BIT_NOT_EXPR,
4790 warning ("comparison is always %d", wanted_code == NE_EXPR);
4792 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
4796 /* If the right sides are not constant, do the same for it. Also,
4797 disallow this optimization if a size or signedness mismatch occurs
4798 between the left and right sides. */
4801 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
4802 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
4803 /* Make sure the two fields on the right
4804 correspond to the left without being swapped. */
4805 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
4808 first_bit = MIN (lr_bitpos, rr_bitpos);
4809 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
4810 rnmode = get_best_mode (end_bit - first_bit, first_bit,
4811 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
4813 if (rnmode == VOIDmode)
4816 rnbitsize = GET_MODE_BITSIZE (rnmode);
4817 rnbitpos = first_bit & ~ (rnbitsize - 1);
4818 rntype = lang_hooks.types.type_for_size (rnbitsize, 1);
4819 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
4821 if (BYTES_BIG_ENDIAN)
4823 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
4824 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
4827 lr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, lr_mask),
4828 size_int (xlr_bitpos), 0);
4829 rr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, rr_mask),
4830 size_int (xrr_bitpos), 0);
4832 /* Make a mask that corresponds to both fields being compared.
4833 Do this for both items being compared. If the operands are the
4834 same size and the bits being compared are in the same position
4835 then we can do this by masking both and comparing the masked
4837 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4838 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
4839 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
4841 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4842 ll_unsignedp || rl_unsignedp);
4843 if (! all_ones_mask_p (ll_mask, lnbitsize))
4844 lhs = build2 (BIT_AND_EXPR, lntype, lhs, ll_mask);
4846 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
4847 lr_unsignedp || rr_unsignedp);
4848 if (! all_ones_mask_p (lr_mask, rnbitsize))
4849 rhs = build2 (BIT_AND_EXPR, rntype, rhs, lr_mask);
4851 return build2 (wanted_code, truth_type, lhs, rhs);
4854 /* There is still another way we can do something: If both pairs of
4855 fields being compared are adjacent, we may be able to make a wider
4856 field containing them both.
4858 Note that we still must mask the lhs/rhs expressions. Furthermore,
4859 the mask must be shifted to account for the shift done by
4860 make_bit_field_ref. */
4861 if ((ll_bitsize + ll_bitpos == rl_bitpos
4862 && lr_bitsize + lr_bitpos == rr_bitpos)
4863 || (ll_bitpos == rl_bitpos + rl_bitsize
4864 && lr_bitpos == rr_bitpos + rr_bitsize))
4868 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
4869 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
4870 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
4871 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
4873 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
4874 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
4875 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
4876 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
4878 /* Convert to the smaller type before masking out unwanted bits. */
4880 if (lntype != rntype)
4882 if (lnbitsize > rnbitsize)
4884 lhs = fold_convert (rntype, lhs);
4885 ll_mask = fold_convert (rntype, ll_mask);
4888 else if (lnbitsize < rnbitsize)
4890 rhs = fold_convert (lntype, rhs);
4891 lr_mask = fold_convert (lntype, lr_mask);
4896 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
4897 lhs = build2 (BIT_AND_EXPR, type, lhs, ll_mask);
4899 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
4900 rhs = build2 (BIT_AND_EXPR, type, rhs, lr_mask);
4902 return build2 (wanted_code, truth_type, lhs, rhs);
4908 /* Handle the case of comparisons with constants. If there is something in
4909 common between the masks, those bits of the constants must be the same.
4910 If not, the condition is always false. Test for this to avoid generating
4911 incorrect code below. */
4912 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
4913 if (! integer_zerop (result)
4914 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
4915 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
4917 if (wanted_code == NE_EXPR)
4919 warning ("%<or%> of unmatched not-equal tests is always 1");
4920 return constant_boolean_node (true, truth_type);
4924 warning ("%<and%> of mutually exclusive equal-tests is always 0");
4925 return constant_boolean_node (false, truth_type);
4929 /* Construct the expression we will return. First get the component
4930 reference we will make. Unless the mask is all ones the width of
4931 that field, perform the mask operation. Then compare with the
4933 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4934 ll_unsignedp || rl_unsignedp);
4936 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4937 if (! all_ones_mask_p (ll_mask, lnbitsize))
4938 result = build2 (BIT_AND_EXPR, lntype, result, ll_mask);
4940 return build2 (wanted_code, truth_type, result,
4941 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
4944 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
4948 optimize_minmax_comparison (tree t)
4950 tree type = TREE_TYPE (t);
4951 tree arg0 = TREE_OPERAND (t, 0);
4952 enum tree_code op_code;
4953 tree comp_const = TREE_OPERAND (t, 1);
4955 int consts_equal, consts_lt;
4958 STRIP_SIGN_NOPS (arg0);
4960 op_code = TREE_CODE (arg0);
4961 minmax_const = TREE_OPERAND (arg0, 1);
4962 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
4963 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
4964 inner = TREE_OPERAND (arg0, 0);
4966 /* If something does not permit us to optimize, return the original tree. */
4967 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
4968 || TREE_CODE (comp_const) != INTEGER_CST
4969 || TREE_CONSTANT_OVERFLOW (comp_const)
4970 || TREE_CODE (minmax_const) != INTEGER_CST
4971 || TREE_CONSTANT_OVERFLOW (minmax_const))
4974 /* Now handle all the various comparison codes. We only handle EQ_EXPR
4975 and GT_EXPR, doing the rest with recursive calls using logical
4977 switch (TREE_CODE (t))
4979 case NE_EXPR: case LT_EXPR: case LE_EXPR:
4981 invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t)));
4985 fold (build2 (TRUTH_ORIF_EXPR, type,
4986 optimize_minmax_comparison
4987 (build2 (EQ_EXPR, type, arg0, comp_const)),
4988 optimize_minmax_comparison
4989 (build2 (GT_EXPR, type, arg0, comp_const))));
4992 if (op_code == MAX_EXPR && consts_equal)
4993 /* MAX (X, 0) == 0 -> X <= 0 */
4994 return fold (build2 (LE_EXPR, type, inner, comp_const));
4996 else if (op_code == MAX_EXPR && consts_lt)
4997 /* MAX (X, 0) == 5 -> X == 5 */
4998 return fold (build2 (EQ_EXPR, type, inner, comp_const));
5000 else if (op_code == MAX_EXPR)
5001 /* MAX (X, 0) == -1 -> false */
5002 return omit_one_operand (type, integer_zero_node, inner);
5004 else if (consts_equal)
5005 /* MIN (X, 0) == 0 -> X >= 0 */
5006 return fold (build2 (GE_EXPR, type, inner, comp_const));
5009 /* MIN (X, 0) == 5 -> false */
5010 return omit_one_operand (type, integer_zero_node, inner);
5013 /* MIN (X, 0) == -1 -> X == -1 */
5014 return fold (build2 (EQ_EXPR, type, inner, comp_const));
5017 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
5018 /* MAX (X, 0) > 0 -> X > 0
5019 MAX (X, 0) > 5 -> X > 5 */
5020 return fold (build2 (GT_EXPR, type, inner, comp_const));
5022 else if (op_code == MAX_EXPR)
5023 /* MAX (X, 0) > -1 -> true */
5024 return omit_one_operand (type, integer_one_node, inner);
5026 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
5027 /* MIN (X, 0) > 0 -> false
5028 MIN (X, 0) > 5 -> false */
5029 return omit_one_operand (type, integer_zero_node, inner);
5032 /* MIN (X, 0) > -1 -> X > -1 */
5033 return fold (build2 (GT_EXPR, type, inner, comp_const));
5040 /* T is an integer expression that is being multiplied, divided, or taken a
5041 modulus (CODE says which and what kind of divide or modulus) by a
5042 constant C. See if we can eliminate that operation by folding it with
5043 other operations already in T. WIDE_TYPE, if non-null, is a type that
5044 should be used for the computation if wider than our type.
5046 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
5047 (X * 2) + (Y * 4). We must, however, be assured that either the original
5048 expression would not overflow or that overflow is undefined for the type
5049 in the language in question.
5051 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
5052 the machine has a multiply-accumulate insn or that this is part of an
5053 addressing calculation.
5055 If we return a non-null expression, it is an equivalent form of the
5056 original computation, but need not be in the original type. */
5059 extract_muldiv (tree t, tree c, enum tree_code code, tree wide_type)
5061 /* To avoid exponential search depth, refuse to allow recursion past
5062 three levels. Beyond that (1) it's highly unlikely that we'll find
5063 something interesting and (2) we've probably processed it before
5064 when we built the inner expression. */
5073 ret = extract_muldiv_1 (t, c, code, wide_type);
5080 extract_muldiv_1 (tree t, tree c, enum tree_code code, tree wide_type)
5082 tree type = TREE_TYPE (t);
5083 enum tree_code tcode = TREE_CODE (t);
5084 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
5085 > GET_MODE_SIZE (TYPE_MODE (type)))
5086 ? wide_type : type);
5088 int same_p = tcode == code;
5089 tree op0 = NULL_TREE, op1 = NULL_TREE;
5091 /* Don't deal with constants of zero here; they confuse the code below. */
5092 if (integer_zerop (c))
5095 if (TREE_CODE_CLASS (tcode) == tcc_unary)
5096 op0 = TREE_OPERAND (t, 0);
5098 if (TREE_CODE_CLASS (tcode) == tcc_binary)
5099 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
5101 /* Note that we need not handle conditional operations here since fold
5102 already handles those cases. So just do arithmetic here. */
5106 /* For a constant, we can always simplify if we are a multiply
5107 or (for divide and modulus) if it is a multiple of our constant. */
5108 if (code == MULT_EXPR
5109 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
5110 return const_binop (code, fold_convert (ctype, t),
5111 fold_convert (ctype, c), 0);
5114 case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
5115 /* If op0 is an expression ... */
5116 if ((COMPARISON_CLASS_P (op0)
5117 || UNARY_CLASS_P (op0)
5118 || BINARY_CLASS_P (op0)
5119 || EXPRESSION_CLASS_P (op0))
5120 /* ... and is unsigned, and its type is smaller than ctype,
5121 then we cannot pass through as widening. */
5122 && ((TYPE_UNSIGNED (TREE_TYPE (op0))
5123 && ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
5124 && TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
5125 && (GET_MODE_SIZE (TYPE_MODE (ctype))
5126 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
5127 /* ... or this is a truncation (t is narrower than op0),
5128 then we cannot pass through this narrowing. */
5129 || (GET_MODE_SIZE (TYPE_MODE (type))
5130 < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0))))
5131 /* ... or signedness changes for division or modulus,
5132 then we cannot pass through this conversion. */
5133 || (code != MULT_EXPR
5134 && (TYPE_UNSIGNED (ctype)
5135 != TYPE_UNSIGNED (TREE_TYPE (op0))))))
5138 /* Pass the constant down and see if we can make a simplification. If
5139 we can, replace this expression with the inner simplification for
5140 possible later conversion to our or some other type. */
5141 if ((t2 = fold_convert (TREE_TYPE (op0), c)) != 0
5142 && TREE_CODE (t2) == INTEGER_CST
5143 && ! TREE_CONSTANT_OVERFLOW (t2)
5144 && (0 != (t1 = extract_muldiv (op0, t2, code,
5146 ? ctype : NULL_TREE))))
5151 /* If widening the type changes it from signed to unsigned, then we
5152 must avoid building ABS_EXPR itself as unsigned. */
5153 if (TYPE_UNSIGNED (ctype) && !TYPE_UNSIGNED (type))
5155 tree cstype = (*lang_hooks.types.signed_type) (ctype);
5156 if ((t1 = extract_muldiv (op0, c, code, cstype)) != 0)
5158 t1 = fold (build1 (tcode, cstype, fold_convert (cstype, t1)));
5159 return fold_convert (ctype, t1);
5165 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
5166 return fold (build1 (tcode, ctype, fold_convert (ctype, t1)));
5169 case MIN_EXPR: case MAX_EXPR:
5170 /* If widening the type changes the signedness, then we can't perform
5171 this optimization as that changes the result. */
5172 if (TYPE_UNSIGNED (ctype) != TYPE_UNSIGNED (type))
5175 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
5176 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0
5177 && (t2 = extract_muldiv (op1, c, code, wide_type)) != 0)
5179 if (tree_int_cst_sgn (c) < 0)
5180 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
5182 return fold (build2 (tcode, ctype, fold_convert (ctype, t1),
5183 fold_convert (ctype, t2)));
5187 case LSHIFT_EXPR: case RSHIFT_EXPR:
5188 /* If the second operand is constant, this is a multiplication
5189 or floor division, by a power of two, so we can treat it that
5190 way unless the multiplier or divisor overflows. Signed
5191 left-shift overflow is implementation-defined rather than
5192 undefined in C90, so do not convert signed left shift into
5194 if (TREE_CODE (op1) == INTEGER_CST
5195 && (tcode == RSHIFT_EXPR || TYPE_UNSIGNED (TREE_TYPE (op0)))
5196 /* const_binop may not detect overflow correctly,
5197 so check for it explicitly here. */
5198 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
5199 && TREE_INT_CST_HIGH (op1) == 0
5200 && 0 != (t1 = fold_convert (ctype,
5201 const_binop (LSHIFT_EXPR,
5204 && ! TREE_OVERFLOW (t1))
5205 return extract_muldiv (build2 (tcode == LSHIFT_EXPR
5206 ? MULT_EXPR : FLOOR_DIV_EXPR,
5207 ctype, fold_convert (ctype, op0), t1),
5208 c, code, wide_type);
5211 case PLUS_EXPR: case MINUS_EXPR:
5212 /* See if we can eliminate the operation on both sides. If we can, we
5213 can return a new PLUS or MINUS. If we can't, the only remaining
5214 cases where we can do anything are if the second operand is a
5216 t1 = extract_muldiv (op0, c, code, wide_type);
5217 t2 = extract_muldiv (op1, c, code, wide_type);
5218 if (t1 != 0 && t2 != 0
5219 && (code == MULT_EXPR
5220 /* If not multiplication, we can only do this if both operands
5221 are divisible by c. */
5222 || (multiple_of_p (ctype, op0, c)
5223 && multiple_of_p (ctype, op1, c))))
5224 return fold (build2 (tcode, ctype, fold_convert (ctype, t1),
5225 fold_convert (ctype, t2)));
5227 /* If this was a subtraction, negate OP1 and set it to be an addition.
5228 This simplifies the logic below. */
5229 if (tcode == MINUS_EXPR)
5230 tcode = PLUS_EXPR, op1 = negate_expr (op1);
5232 if (TREE_CODE (op1) != INTEGER_CST)
5235 /* If either OP1 or C are negative, this optimization is not safe for
5236 some of the division and remainder types while for others we need
5237 to change the code. */
5238 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
5240 if (code == CEIL_DIV_EXPR)
5241 code = FLOOR_DIV_EXPR;
5242 else if (code == FLOOR_DIV_EXPR)
5243 code = CEIL_DIV_EXPR;
5244 else if (code != MULT_EXPR
5245 && code != CEIL_MOD_EXPR && code != FLOOR_MOD_EXPR)
5249 /* If it's a multiply or a division/modulus operation of a multiple
5250 of our constant, do the operation and verify it doesn't overflow. */
5251 if (code == MULT_EXPR
5252 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5254 op1 = const_binop (code, fold_convert (ctype, op1),
5255 fold_convert (ctype, c), 0);
5256 /* We allow the constant to overflow with wrapping semantics. */
5258 || (TREE_OVERFLOW (op1) && ! flag_wrapv))
5264 /* If we have an unsigned type is not a sizetype, we cannot widen
5265 the operation since it will change the result if the original
5266 computation overflowed. */
5267 if (TYPE_UNSIGNED (ctype)
5268 && ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
5272 /* If we were able to eliminate our operation from the first side,
5273 apply our operation to the second side and reform the PLUS. */
5274 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
5275 return fold (build2 (tcode, ctype, fold_convert (ctype, t1), op1));
5277 /* The last case is if we are a multiply. In that case, we can
5278 apply the distributive law to commute the multiply and addition
5279 if the multiplication of the constants doesn't overflow. */
5280 if (code == MULT_EXPR)
5281 return fold (build2 (tcode, ctype,
5282 fold (build2 (code, ctype,
5283 fold_convert (ctype, op0),
5284 fold_convert (ctype, c))),
5290 /* We have a special case here if we are doing something like
5291 (C * 8) % 4 since we know that's zero. */
5292 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
5293 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
5294 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
5295 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5296 return omit_one_operand (type, integer_zero_node, op0);
5298 /* ... fall through ... */
5300 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
5301 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
5302 /* If we can extract our operation from the LHS, do so and return a
5303 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
5304 do something only if the second operand is a constant. */
5306 && (t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
5307 return fold (build2 (tcode, ctype, fold_convert (ctype, t1),
5308 fold_convert (ctype, op1)));
5309 else if (tcode == MULT_EXPR && code == MULT_EXPR
5310 && (t1 = extract_muldiv (op1, c, code, wide_type)) != 0)
5311 return fold (build2 (tcode, ctype, fold_convert (ctype, op0),
5312 fold_convert (ctype, t1)));
5313 else if (TREE_CODE (op1) != INTEGER_CST)
5316 /* If these are the same operation types, we can associate them
5317 assuming no overflow. */
5319 && 0 != (t1 = const_binop (MULT_EXPR, fold_convert (ctype, op1),
5320 fold_convert (ctype, c), 0))
5321 && ! TREE_OVERFLOW (t1))
5322 return fold (build2 (tcode, ctype, fold_convert (ctype, op0), t1));
5324 /* If these operations "cancel" each other, we have the main
5325 optimizations of this pass, which occur when either constant is a
5326 multiple of the other, in which case we replace this with either an
5327 operation or CODE or TCODE.
5329 If we have an unsigned type that is not a sizetype, we cannot do
5330 this since it will change the result if the original computation
5332 if ((! TYPE_UNSIGNED (ctype)
5333 || (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
5335 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
5336 || (tcode == MULT_EXPR
5337 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
5338 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR)))
5340 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5341 return fold (build2 (tcode, ctype, fold_convert (ctype, op0),
5342 fold_convert (ctype,
5343 const_binop (TRUNC_DIV_EXPR,
5345 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
5346 return fold (build2 (code, ctype, fold_convert (ctype, op0),
5347 fold_convert (ctype,
5348 const_binop (TRUNC_DIV_EXPR,
5360 /* Return a node which has the indicated constant VALUE (either 0 or
5361 1), and is of the indicated TYPE. */
5364 constant_boolean_node (int value, tree type)
5366 if (type == integer_type_node)
5367 return value ? integer_one_node : integer_zero_node;
5368 else if (type == boolean_type_node)
5369 return value ? boolean_true_node : boolean_false_node;
5370 else if (TREE_CODE (type) == BOOLEAN_TYPE)
5371 return lang_hooks.truthvalue_conversion (value ? integer_one_node
5372 : integer_zero_node);
5374 return build_int_cst (type, value);
5377 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
5378 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
5379 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
5380 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
5381 COND is the first argument to CODE; otherwise (as in the example
5382 given here), it is the second argument. TYPE is the type of the
5383 original expression. Return NULL_TREE if no simplification is
5387 fold_binary_op_with_conditional_arg (enum tree_code code, tree type,
5388 tree cond, tree arg, int cond_first_p)
5390 tree test, true_value, false_value;
5391 tree lhs = NULL_TREE;
5392 tree rhs = NULL_TREE;
5394 /* This transformation is only worthwhile if we don't have to wrap
5395 arg in a SAVE_EXPR, and the operation can be simplified on at least
5396 one of the branches once its pushed inside the COND_EXPR. */
5397 if (!TREE_CONSTANT (arg))
5400 if (TREE_CODE (cond) == COND_EXPR)
5402 test = TREE_OPERAND (cond, 0);
5403 true_value = TREE_OPERAND (cond, 1);
5404 false_value = TREE_OPERAND (cond, 2);
5405 /* If this operand throws an expression, then it does not make
5406 sense to try to perform a logical or arithmetic operation
5408 if (VOID_TYPE_P (TREE_TYPE (true_value)))
5410 if (VOID_TYPE_P (TREE_TYPE (false_value)))
5415 tree testtype = TREE_TYPE (cond);
5417 true_value = constant_boolean_node (true, testtype);
5418 false_value = constant_boolean_node (false, testtype);
5422 lhs = fold (cond_first_p ? build2 (code, type, true_value, arg)
5423 : build2 (code, type, arg, true_value));
5425 rhs = fold (cond_first_p ? build2 (code, type, false_value, arg)
5426 : build2 (code, type, arg, false_value));
5428 test = fold (build3 (COND_EXPR, type, test, lhs, rhs));
5429 return fold_convert (type, test);
5433 /* Subroutine of fold() that checks for the addition of +/- 0.0.
5435 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
5436 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
5437 ADDEND is the same as X.
5439 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
5440 and finite. The problematic cases are when X is zero, and its mode
5441 has signed zeros. In the case of rounding towards -infinity,
5442 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
5443 modes, X + 0 is not the same as X because -0 + 0 is 0. */
5446 fold_real_zero_addition_p (tree type, tree addend, int negate)
5448 if (!real_zerop (addend))
5451 /* Don't allow the fold with -fsignaling-nans. */
5452 if (HONOR_SNANS (TYPE_MODE (type)))
5455 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
5456 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
5459 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
5460 if (TREE_CODE (addend) == REAL_CST
5461 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
5464 /* The mode has signed zeros, and we have to honor their sign.
5465 In this situation, there is only one case we can return true for.
5466 X - 0 is the same as X unless rounding towards -infinity is
5468 return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
5471 /* Subroutine of fold() that checks comparisons of built-in math
5472 functions against real constants.
5474 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
5475 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
5476 is the type of the result and ARG0 and ARG1 are the operands of the
5477 comparison. ARG1 must be a TREE_REAL_CST.
5479 The function returns the constant folded tree if a simplification
5480 can be made, and NULL_TREE otherwise. */
5483 fold_mathfn_compare (enum built_in_function fcode, enum tree_code code,
5484 tree type, tree arg0, tree arg1)
5488 if (BUILTIN_SQRT_P (fcode))
5490 tree arg = TREE_VALUE (TREE_OPERAND (arg0, 1));
5491 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg0));
5493 c = TREE_REAL_CST (arg1);
5494 if (REAL_VALUE_NEGATIVE (c))
5496 /* sqrt(x) < y is always false, if y is negative. */
5497 if (code == EQ_EXPR || code == LT_EXPR || code == LE_EXPR)
5498 return omit_one_operand (type, integer_zero_node, arg);
5500 /* sqrt(x) > y is always true, if y is negative and we
5501 don't care about NaNs, i.e. negative values of x. */
5502 if (code == NE_EXPR || !HONOR_NANS (mode))
5503 return omit_one_operand (type, integer_one_node, arg);
5505 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
5506 return fold (build2 (GE_EXPR, type, arg,
5507 build_real (TREE_TYPE (arg), dconst0)));
5509 else if (code == GT_EXPR || code == GE_EXPR)
5513 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
5514 real_convert (&c2, mode, &c2);
5516 if (REAL_VALUE_ISINF (c2))
5518 /* sqrt(x) > y is x == +Inf, when y is very large. */
5519 if (HONOR_INFINITIES (mode))
5520 return fold (build2 (EQ_EXPR, type, arg,
5521 build_real (TREE_TYPE (arg), c2)));
5523 /* sqrt(x) > y is always false, when y is very large
5524 and we don't care about infinities. */
5525 return omit_one_operand (type, integer_zero_node, arg);
5528 /* sqrt(x) > c is the same as x > c*c. */
5529 return fold (build2 (code, type, arg,
5530 build_real (TREE_TYPE (arg), c2)));
5532 else if (code == LT_EXPR || code == LE_EXPR)
5536 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
5537 real_convert (&c2, mode, &c2);
5539 if (REAL_VALUE_ISINF (c2))
5541 /* sqrt(x) < y is always true, when y is a very large
5542 value and we don't care about NaNs or Infinities. */
5543 if (! HONOR_NANS (mode) && ! HONOR_INFINITIES (mode))
5544 return omit_one_operand (type, integer_one_node, arg);
5546 /* sqrt(x) < y is x != +Inf when y is very large and we
5547 don't care about NaNs. */
5548 if (! HONOR_NANS (mode))
5549 return fold (build2 (NE_EXPR, type, arg,
5550 build_real (TREE_TYPE (arg), c2)));
5552 /* sqrt(x) < y is x >= 0 when y is very large and we
5553 don't care about Infinities. */
5554 if (! HONOR_INFINITIES (mode))
5555 return fold (build2 (GE_EXPR, type, arg,
5556 build_real (TREE_TYPE (arg), dconst0)));
5558 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
5559 if (lang_hooks.decls.global_bindings_p () != 0
5560 || CONTAINS_PLACEHOLDER_P (arg))
5563 arg = save_expr (arg);
5564 return fold (build2 (TRUTH_ANDIF_EXPR, type,
5565 fold (build2 (GE_EXPR, type, arg,
5566 build_real (TREE_TYPE (arg),
5568 fold (build2 (NE_EXPR, type, arg,
5569 build_real (TREE_TYPE (arg),
5573 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
5574 if (! HONOR_NANS (mode))
5575 return fold (build2 (code, type, arg,
5576 build_real (TREE_TYPE (arg), c2)));
5578 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
5579 if (lang_hooks.decls.global_bindings_p () == 0
5580 && ! CONTAINS_PLACEHOLDER_P (arg))
5582 arg = save_expr (arg);
5583 return fold (build2 (TRUTH_ANDIF_EXPR, type,
5584 fold (build2 (GE_EXPR, type, arg,
5585 build_real (TREE_TYPE (arg),
5587 fold (build2 (code, type, arg,
5588 build_real (TREE_TYPE (arg),
5597 /* Subroutine of fold() that optimizes comparisons against Infinities,
5598 either +Inf or -Inf.
5600 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
5601 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
5602 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
5604 The function returns the constant folded tree if a simplification
5605 can be made, and NULL_TREE otherwise. */
5608 fold_inf_compare (enum tree_code code, tree type, tree arg0, tree arg1)
5610 enum machine_mode mode;
5611 REAL_VALUE_TYPE max;
5615 mode = TYPE_MODE (TREE_TYPE (arg0));
5617 /* For negative infinity swap the sense of the comparison. */
5618 neg = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1));
5620 code = swap_tree_comparison (code);
5625 /* x > +Inf is always false, if with ignore sNANs. */
5626 if (HONOR_SNANS (mode))
5628 return omit_one_operand (type, integer_zero_node, arg0);
5631 /* x <= +Inf is always true, if we don't case about NaNs. */
5632 if (! HONOR_NANS (mode))
5633 return omit_one_operand (type, integer_one_node, arg0);
5635 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
5636 if (lang_hooks.decls.global_bindings_p () == 0
5637 && ! CONTAINS_PLACEHOLDER_P (arg0))
5639 arg0 = save_expr (arg0);
5640 return fold (build2 (EQ_EXPR, type, arg0, arg0));
5646 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
5647 real_maxval (&max, neg, mode);
5648 return fold (build2 (neg ? LT_EXPR : GT_EXPR, type,
5649 arg0, build_real (TREE_TYPE (arg0), max)));
5652 /* x < +Inf is always equal to x <= DBL_MAX. */
5653 real_maxval (&max, neg, mode);
5654 return fold (build2 (neg ? GE_EXPR : LE_EXPR, type,
5655 arg0, build_real (TREE_TYPE (arg0), max)));
5658 /* x != +Inf is always equal to !(x > DBL_MAX). */
5659 real_maxval (&max, neg, mode);
5660 if (! HONOR_NANS (mode))
5661 return fold (build2 (neg ? GE_EXPR : LE_EXPR, type,
5662 arg0, build_real (TREE_TYPE (arg0), max)));
5664 /* The transformation below creates non-gimple code and thus is
5665 not appropriate if we are in gimple form. */
5669 temp = fold (build2 (neg ? LT_EXPR : GT_EXPR, type,
5670 arg0, build_real (TREE_TYPE (arg0), max)));
5671 return fold (build1 (TRUTH_NOT_EXPR, type, temp));
5680 /* Subroutine of fold() that optimizes comparisons of a division by
5681 a nonzero integer constant against an integer constant, i.e.
5684 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
5685 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
5686 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
5688 The function returns the constant folded tree if a simplification
5689 can be made, and NULL_TREE otherwise. */
5692 fold_div_compare (enum tree_code code, tree type, tree arg0, tree arg1)
5694 tree prod, tmp, hi, lo;
5695 tree arg00 = TREE_OPERAND (arg0, 0);
5696 tree arg01 = TREE_OPERAND (arg0, 1);
5697 unsigned HOST_WIDE_INT lpart;
5698 HOST_WIDE_INT hpart;
5701 /* We have to do this the hard way to detect unsigned overflow.
5702 prod = int_const_binop (MULT_EXPR, arg01, arg1, 0); */
5703 overflow = mul_double (TREE_INT_CST_LOW (arg01),
5704 TREE_INT_CST_HIGH (arg01),
5705 TREE_INT_CST_LOW (arg1),
5706 TREE_INT_CST_HIGH (arg1), &lpart, &hpart);
5707 prod = build_int_cst_wide (TREE_TYPE (arg00), lpart, hpart);
5708 prod = force_fit_type (prod, -1, overflow, false);
5710 if (TYPE_UNSIGNED (TREE_TYPE (arg0)))
5712 tmp = int_const_binop (MINUS_EXPR, arg01, integer_one_node, 0);
5715 /* Likewise hi = int_const_binop (PLUS_EXPR, prod, tmp, 0). */
5716 overflow = add_double (TREE_INT_CST_LOW (prod),
5717 TREE_INT_CST_HIGH (prod),
5718 TREE_INT_CST_LOW (tmp),
5719 TREE_INT_CST_HIGH (tmp),
5721 hi = build_int_cst_wide (TREE_TYPE (arg00), lpart, hpart);
5722 hi = force_fit_type (hi, -1, overflow | TREE_OVERFLOW (prod),
5723 TREE_CONSTANT_OVERFLOW (prod));
5725 else if (tree_int_cst_sgn (arg01) >= 0)
5727 tmp = int_const_binop (MINUS_EXPR, arg01, integer_one_node, 0);
5728 switch (tree_int_cst_sgn (arg1))
5731 lo = int_const_binop (MINUS_EXPR, prod, tmp, 0);
5736 lo = fold_negate_const (tmp, TREE_TYPE (arg0));
5741 hi = int_const_binop (PLUS_EXPR, prod, tmp, 0);
5751 /* A negative divisor reverses the relational operators. */
5752 code = swap_tree_comparison (code);
5754 tmp = int_const_binop (PLUS_EXPR, arg01, integer_one_node, 0);
5755 switch (tree_int_cst_sgn (arg1))
5758 hi = int_const_binop (MINUS_EXPR, prod, tmp, 0);
5763 hi = fold_negate_const (tmp, TREE_TYPE (arg0));
5768 lo = int_const_binop (PLUS_EXPR, prod, tmp, 0);
5780 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
5781 return omit_one_operand (type, integer_zero_node, arg00);
5782 if (TREE_OVERFLOW (hi))
5783 return fold (build2 (GE_EXPR, type, arg00, lo));
5784 if (TREE_OVERFLOW (lo))
5785 return fold (build2 (LE_EXPR, type, arg00, hi));
5786 return build_range_check (type, arg00, 1, lo, hi);
5789 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
5790 return omit_one_operand (type, integer_one_node, arg00);
5791 if (TREE_OVERFLOW (hi))
5792 return fold (build2 (LT_EXPR, type, arg00, lo));
5793 if (TREE_OVERFLOW (lo))
5794 return fold (build2 (GT_EXPR, type, arg00, hi));
5795 return build_range_check (type, arg00, 0, lo, hi);
5798 if (TREE_OVERFLOW (lo))
5799 return omit_one_operand (type, integer_zero_node, arg00);
5800 return fold (build2 (LT_EXPR, type, arg00, lo));
5803 if (TREE_OVERFLOW (hi))
5804 return omit_one_operand (type, integer_one_node, arg00);
5805 return fold (build2 (LE_EXPR, type, arg00, hi));
5808 if (TREE_OVERFLOW (hi))
5809 return omit_one_operand (type, integer_zero_node, arg00);
5810 return fold (build2 (GT_EXPR, type, arg00, hi));
5813 if (TREE_OVERFLOW (lo))
5814 return omit_one_operand (type, integer_one_node, arg00);
5815 return fold (build2 (GE_EXPR, type, arg00, lo));
5825 /* If CODE with arguments ARG0 and ARG1 represents a single bit
5826 equality/inequality test, then return a simplified form of
5827 the test using shifts and logical operations. Otherwise return
5828 NULL. TYPE is the desired result type. */
5831 fold_single_bit_test (enum tree_code code, tree arg0, tree arg1,
5834 /* If this is testing a single bit, we can optimize the test. */
5835 if ((code == NE_EXPR || code == EQ_EXPR)
5836 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
5837 && integer_pow2p (TREE_OPERAND (arg0, 1)))
5839 tree inner = TREE_OPERAND (arg0, 0);
5840 tree type = TREE_TYPE (arg0);
5841 int bitnum = tree_log2 (TREE_OPERAND (arg0, 1));
5842 enum machine_mode operand_mode = TYPE_MODE (type);
5844 tree signed_type, unsigned_type, intermediate_type;
5847 /* If we have (A & C) != 0 where C is the sign bit of A, convert
5848 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
5849 arg00 = sign_bit_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
5850 if (arg00 != NULL_TREE
5851 /* This is only a win if casting to a signed type is cheap,
5852 i.e. when arg00's type is not a partial mode. */
5853 && TYPE_PRECISION (TREE_TYPE (arg00))
5854 == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg00))))
5856 tree stype = lang_hooks.types.signed_type (TREE_TYPE (arg00));
5857 return fold (build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
5858 result_type, fold_convert (stype, arg00),
5859 fold_convert (stype, integer_zero_node)));
5862 /* Otherwise we have (A & C) != 0 where C is a single bit,
5863 convert that into ((A >> C2) & 1). Where C2 = log2(C).
5864 Similarly for (A & C) == 0. */
5866 /* If INNER is a right shift of a constant and it plus BITNUM does
5867 not overflow, adjust BITNUM and INNER. */
5868 if (TREE_CODE (inner) == RSHIFT_EXPR
5869 && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST
5870 && TREE_INT_CST_HIGH (TREE_OPERAND (inner, 1)) == 0
5871 && bitnum < TYPE_PRECISION (type)
5872 && 0 > compare_tree_int (TREE_OPERAND (inner, 1),
5873 bitnum - TYPE_PRECISION (type)))
5875 bitnum += TREE_INT_CST_LOW (TREE_OPERAND (inner, 1));
5876 inner = TREE_OPERAND (inner, 0);
5879 /* If we are going to be able to omit the AND below, we must do our
5880 operations as unsigned. If we must use the AND, we have a choice.
5881 Normally unsigned is faster, but for some machines signed is. */
5882 #ifdef LOAD_EXTEND_OP
5883 ops_unsigned = (LOAD_EXTEND_OP (operand_mode) == SIGN_EXTEND
5884 && !flag_syntax_only) ? 0 : 1;
5889 signed_type = lang_hooks.types.type_for_mode (operand_mode, 0);
5890 unsigned_type = lang_hooks.types.type_for_mode (operand_mode, 1);
5891 intermediate_type = ops_unsigned ? unsigned_type : signed_type;
5892 inner = fold_convert (intermediate_type, inner);
5895 inner = build2 (RSHIFT_EXPR, intermediate_type,
5896 inner, size_int (bitnum));
5898 if (code == EQ_EXPR)
5899 inner = fold (build2 (BIT_XOR_EXPR, intermediate_type,
5900 inner, integer_one_node));
5902 /* Put the AND last so it can combine with more things. */
5903 inner = build2 (BIT_AND_EXPR, intermediate_type,
5904 inner, integer_one_node);
5906 /* Make sure to return the proper type. */
5907 inner = fold_convert (result_type, inner);
5914 /* Check whether we are allowed to reorder operands arg0 and arg1,
5915 such that the evaluation of arg1 occurs before arg0. */
5918 reorder_operands_p (tree arg0, tree arg1)
5920 if (! flag_evaluation_order)
5922 if (TREE_CONSTANT (arg0) || TREE_CONSTANT (arg1))
5924 return ! TREE_SIDE_EFFECTS (arg0)
5925 && ! TREE_SIDE_EFFECTS (arg1);
5928 /* Test whether it is preferable two swap two operands, ARG0 and
5929 ARG1, for example because ARG0 is an integer constant and ARG1
5930 isn't. If REORDER is true, only recommend swapping if we can
5931 evaluate the operands in reverse order. */
5934 tree_swap_operands_p (tree arg0, tree arg1, bool reorder)
5936 STRIP_SIGN_NOPS (arg0);
5937 STRIP_SIGN_NOPS (arg1);
5939 if (TREE_CODE (arg1) == INTEGER_CST)
5941 if (TREE_CODE (arg0) == INTEGER_CST)
5944 if (TREE_CODE (arg1) == REAL_CST)
5946 if (TREE_CODE (arg0) == REAL_CST)
5949 if (TREE_CODE (arg1) == COMPLEX_CST)
5951 if (TREE_CODE (arg0) == COMPLEX_CST)
5954 if (TREE_CONSTANT (arg1))
5956 if (TREE_CONSTANT (arg0))
5962 if (reorder && flag_evaluation_order
5963 && (TREE_SIDE_EFFECTS (arg0) || TREE_SIDE_EFFECTS (arg1)))
5971 /* It is preferable to swap two SSA_NAME to ensure a canonical form
5972 for commutative and comparison operators. Ensuring a canonical
5973 form allows the optimizers to find additional redundancies without
5974 having to explicitly check for both orderings. */
5975 if (TREE_CODE (arg0) == SSA_NAME
5976 && TREE_CODE (arg1) == SSA_NAME
5977 && SSA_NAME_VERSION (arg0) > SSA_NAME_VERSION (arg1))
5983 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where
5984 ARG0 is extended to a wider type. */
5987 fold_widened_comparison (enum tree_code code, tree type, tree arg0, tree arg1)
5989 tree arg0_unw = get_unwidened (arg0, NULL_TREE);
5991 tree shorter_type, outer_type;
5995 if (arg0_unw == arg0)
5997 shorter_type = TREE_TYPE (arg0_unw);
5999 if (TYPE_PRECISION (TREE_TYPE (arg0)) <= TYPE_PRECISION (shorter_type))
6002 arg1_unw = get_unwidened (arg1, shorter_type);
6006 /* If possible, express the comparison in the shorter mode. */
6007 if ((code == EQ_EXPR || code == NE_EXPR
6008 || TYPE_UNSIGNED (TREE_TYPE (arg0)) == TYPE_UNSIGNED (shorter_type))
6009 && (TREE_TYPE (arg1_unw) == shorter_type
6010 || (TREE_CODE (arg1_unw) == INTEGER_CST
6011 && TREE_CODE (shorter_type) == INTEGER_TYPE
6012 && int_fits_type_p (arg1_unw, shorter_type))))
6013 return fold (build (code, type, arg0_unw,
6014 fold_convert (shorter_type, arg1_unw)));
6016 if (TREE_CODE (arg1_unw) != INTEGER_CST)
6019 /* If we are comparing with the integer that does not fit into the range
6020 of the shorter type, the result is known. */
6021 outer_type = TREE_TYPE (arg1_unw);
6022 min = lower_bound_in_type (outer_type, shorter_type);
6023 max = upper_bound_in_type (outer_type, shorter_type);
6025 above = integer_nonzerop (fold_relational_const (LT_EXPR, type,
6027 below = integer_nonzerop (fold_relational_const (LT_EXPR, type,
6034 return omit_one_operand (type, integer_zero_node, arg0);
6039 return omit_one_operand (type, integer_one_node, arg0);
6045 return omit_one_operand (type, integer_one_node, arg0);
6047 return omit_one_operand (type, integer_zero_node, arg0);
6052 return omit_one_operand (type, integer_zero_node, arg0);
6054 return omit_one_operand (type, integer_one_node, arg0);
6063 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where for
6064 ARG0 just the signedness is changed. */
6067 fold_sign_changed_comparison (enum tree_code code, tree type,
6068 tree arg0, tree arg1)
6070 tree arg0_inner, tmp;
6071 tree inner_type, outer_type;
6073 if (TREE_CODE (arg0) != NOP_EXPR)
6076 outer_type = TREE_TYPE (arg0);
6077 arg0_inner = TREE_OPERAND (arg0, 0);
6078 inner_type = TREE_TYPE (arg0_inner);
6080 if (TYPE_PRECISION (inner_type) != TYPE_PRECISION (outer_type))
6083 if (TREE_CODE (arg1) != INTEGER_CST
6084 && !(TREE_CODE (arg1) == NOP_EXPR
6085 && TREE_TYPE (TREE_OPERAND (arg1, 0)) == inner_type))
6088 if (TYPE_UNSIGNED (inner_type) != TYPE_UNSIGNED (outer_type)
6093 if (TREE_CODE (arg1) == INTEGER_CST)
6095 tmp = build_int_cst_wide (inner_type,
6096 TREE_INT_CST_LOW (arg1),
6097 TREE_INT_CST_HIGH (arg1));
6098 arg1 = force_fit_type (tmp, 0,
6099 TREE_OVERFLOW (arg1),
6100 TREE_CONSTANT_OVERFLOW (arg1));
6103 arg1 = fold_convert (inner_type, arg1);
6105 return fold (build (code, type, arg0_inner, arg1));
6108 /* Tries to replace &a[idx] CODE s * delta with &a[idx CODE delta], if s is
6109 step of the array. TYPE is the type of the expression. ADDR is the address.
6110 MULT is the multiplicative expression. If the function succeeds, the new
6111 address expression is returned. Otherwise NULL_TREE is returned. */
6114 try_move_mult_to_index (tree type, enum tree_code code, tree addr, tree mult)
6116 tree s, delta, step;
6117 tree arg0 = TREE_OPERAND (mult, 0), arg1 = TREE_OPERAND (mult, 1);
6118 tree ref = TREE_OPERAND (addr, 0), pref;
6125 if (TREE_CODE (arg0) == INTEGER_CST)
6130 else if (TREE_CODE (arg1) == INTEGER_CST)
6138 for (;; ref = TREE_OPERAND (ref, 0))
6140 if (TREE_CODE (ref) == ARRAY_REF)
6142 step = array_ref_element_size (ref);
6144 if (TREE_CODE (step) != INTEGER_CST)
6147 itype = TREE_TYPE (step);
6149 /* If the type sizes do not match, we might run into problems
6150 when one of them would overflow. */
6151 if (TYPE_PRECISION (itype) != TYPE_PRECISION (type))
6154 if (!operand_equal_p (step, fold_convert (itype, s), 0))
6157 delta = fold_convert (itype, delta);
6161 if (!handled_component_p (ref))
6165 /* We found the suitable array reference. So copy everything up to it,
6166 and replace the index. */
6168 pref = TREE_OPERAND (addr, 0);
6169 ret = copy_node (pref);
6174 pref = TREE_OPERAND (pref, 0);
6175 TREE_OPERAND (pos, 0) = copy_node (pref);
6176 pos = TREE_OPERAND (pos, 0);
6179 TREE_OPERAND (pos, 1) = fold (build2 (code, itype,
6180 TREE_OPERAND (pos, 1),
6183 return build1 (ADDR_EXPR, type, ret);
6187 /* Fold A < X && A + 1 > Y to A < X && A >= Y. Normally A + 1 > Y
6188 means A >= Y && A != MAX, but in this case we know that
6189 A < X <= MAX. INEQ is A + 1 > Y, BOUND is A < X. */
6192 fold_to_nonsharp_ineq_using_bound (tree ineq, tree bound)
6194 tree a, typea, type = TREE_TYPE (ineq), a1, diff, y;
6196 if (TREE_CODE (bound) == LT_EXPR)
6197 a = TREE_OPERAND (bound, 0);
6198 else if (TREE_CODE (bound) == GT_EXPR)
6199 a = TREE_OPERAND (bound, 1);
6203 typea = TREE_TYPE (a);
6204 if (!INTEGRAL_TYPE_P (typea)
6205 && !POINTER_TYPE_P (typea))
6208 if (TREE_CODE (ineq) == LT_EXPR)
6210 a1 = TREE_OPERAND (ineq, 1);
6211 y = TREE_OPERAND (ineq, 0);
6213 else if (TREE_CODE (ineq) == GT_EXPR)
6215 a1 = TREE_OPERAND (ineq, 0);
6216 y = TREE_OPERAND (ineq, 1);
6221 if (TREE_TYPE (a1) != typea)
6224 diff = fold (build2 (MINUS_EXPR, typea, a1, a));
6225 if (!integer_onep (diff))
6228 return fold (build2 (GE_EXPR, type, a, y));
6231 /* Perform constant folding and related simplification of EXPR.
6232 The related simplifications include x*1 => x, x*0 => 0, etc.,
6233 and application of the associative law.
6234 NOP_EXPR conversions may be removed freely (as long as we
6235 are careful not to change the type of the overall expression).
6236 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
6237 but we can constant-fold them if they have constant operands. */
6239 #ifdef ENABLE_FOLD_CHECKING
6240 # define fold(x) fold_1 (x)
6241 static tree fold_1 (tree);
6247 const tree t = expr;
6248 const tree type = TREE_TYPE (expr);
6249 tree t1 = NULL_TREE;
6251 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
6252 enum tree_code code = TREE_CODE (t);
6253 enum tree_code_class kind = TREE_CODE_CLASS (code);
6255 /* WINS will be nonzero when the switch is done
6256 if all operands are constant. */
6259 /* Return right away if a constant. */
6260 if (kind == tcc_constant)
6263 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
6267 /* Special case for conversion ops that can have fixed point args. */
6268 arg0 = TREE_OPERAND (t, 0);
6270 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
6272 STRIP_SIGN_NOPS (arg0);
6274 if (arg0 != 0 && TREE_CODE (arg0) == COMPLEX_CST)
6275 subop = TREE_REALPART (arg0);
6279 if (subop != 0 && TREE_CODE (subop) != INTEGER_CST
6280 && TREE_CODE (subop) != REAL_CST)
6281 /* Note that TREE_CONSTANT isn't enough:
6282 static var addresses are constant but we can't
6283 do arithmetic on them. */
6286 else if (IS_EXPR_CODE_CLASS (kind))
6288 int len = TREE_CODE_LENGTH (code);
6290 for (i = 0; i < len; i++)
6292 tree op = TREE_OPERAND (t, i);
6296 continue; /* Valid for CALL_EXPR, at least. */
6298 /* Strip any conversions that don't change the mode. This is
6299 safe for every expression, except for a comparison expression
6300 because its signedness is derived from its operands. So, in
6301 the latter case, only strip conversions that don't change the
6304 Note that this is done as an internal manipulation within the
6305 constant folder, in order to find the simplest representation
6306 of the arguments so that their form can be studied. In any
6307 cases, the appropriate type conversions should be put back in
6308 the tree that will get out of the constant folder. */
6309 if (kind == tcc_comparison)
6310 STRIP_SIGN_NOPS (op);
6314 if (TREE_CODE (op) == COMPLEX_CST)
6315 subop = TREE_REALPART (op);
6319 if (TREE_CODE (subop) != INTEGER_CST
6320 && TREE_CODE (subop) != REAL_CST)
6321 /* Note that TREE_CONSTANT isn't enough:
6322 static var addresses are constant but we can't
6323 do arithmetic on them. */
6333 /* If this is a commutative operation, and ARG0 is a constant, move it
6334 to ARG1 to reduce the number of tests below. */
6335 if (commutative_tree_code (code)
6336 && tree_swap_operands_p (arg0, arg1, true))
6337 return fold (build2 (code, type, TREE_OPERAND (t, 1),
6338 TREE_OPERAND (t, 0)));
6340 /* Now WINS is set as described above,
6341 ARG0 is the first operand of EXPR,
6342 and ARG1 is the second operand (if it has more than one operand).
6344 First check for cases where an arithmetic operation is applied to a
6345 compound, conditional, or comparison operation. Push the arithmetic
6346 operation inside the compound or conditional to see if any folding
6347 can then be done. Convert comparison to conditional for this purpose.
6348 The also optimizes non-constant cases that used to be done in
6351 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
6352 one of the operands is a comparison and the other is a comparison, a
6353 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
6354 code below would make the expression more complex. Change it to a
6355 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
6356 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
6358 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
6359 || code == EQ_EXPR || code == NE_EXPR)
6360 && ((truth_value_p (TREE_CODE (arg0))
6361 && (truth_value_p (TREE_CODE (arg1))
6362 || (TREE_CODE (arg1) == BIT_AND_EXPR
6363 && integer_onep (TREE_OPERAND (arg1, 1)))))
6364 || (truth_value_p (TREE_CODE (arg1))
6365 && (truth_value_p (TREE_CODE (arg0))
6366 || (TREE_CODE (arg0) == BIT_AND_EXPR
6367 && integer_onep (TREE_OPERAND (arg0, 1)))))))
6369 tem = fold (build2 (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
6370 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
6372 type, fold_convert (boolean_type_node, arg0),
6373 fold_convert (boolean_type_node, arg1)));
6375 if (code == EQ_EXPR)
6376 tem = invert_truthvalue (tem);
6381 if (TREE_CODE_CLASS (code) == tcc_unary)
6383 if (TREE_CODE (arg0) == COMPOUND_EXPR)
6384 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
6385 fold (build1 (code, type, TREE_OPERAND (arg0, 1))));
6386 else if (TREE_CODE (arg0) == COND_EXPR)
6388 tree arg01 = TREE_OPERAND (arg0, 1);
6389 tree arg02 = TREE_OPERAND (arg0, 2);
6390 if (! VOID_TYPE_P (TREE_TYPE (arg01)))
6391 arg01 = fold (build1 (code, type, arg01));
6392 if (! VOID_TYPE_P (TREE_TYPE (arg02)))
6393 arg02 = fold (build1 (code, type, arg02));
6394 tem = fold (build3 (COND_EXPR, type, TREE_OPERAND (arg0, 0),
6397 /* If this was a conversion, and all we did was to move into
6398 inside the COND_EXPR, bring it back out. But leave it if
6399 it is a conversion from integer to integer and the
6400 result precision is no wider than a word since such a
6401 conversion is cheap and may be optimized away by combine,
6402 while it couldn't if it were outside the COND_EXPR. Then return
6403 so we don't get into an infinite recursion loop taking the
6404 conversion out and then back in. */
6406 if ((code == NOP_EXPR || code == CONVERT_EXPR
6407 || code == NON_LVALUE_EXPR)
6408 && TREE_CODE (tem) == COND_EXPR
6409 && TREE_CODE (TREE_OPERAND (tem, 1)) == code
6410 && TREE_CODE (TREE_OPERAND (tem, 2)) == code
6411 && ! VOID_TYPE_P (TREE_OPERAND (tem, 1))
6412 && ! VOID_TYPE_P (TREE_OPERAND (tem, 2))
6413 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))
6414 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 2), 0)))
6415 && (! (INTEGRAL_TYPE_P (TREE_TYPE (tem))
6417 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))))
6418 && TYPE_PRECISION (TREE_TYPE (tem)) <= BITS_PER_WORD)
6419 || flag_syntax_only))
6420 tem = build1 (code, type,
6422 TREE_TYPE (TREE_OPERAND
6423 (TREE_OPERAND (tem, 1), 0)),
6424 TREE_OPERAND (tem, 0),
6425 TREE_OPERAND (TREE_OPERAND (tem, 1), 0),
6426 TREE_OPERAND (TREE_OPERAND (tem, 2), 0)));
6429 else if (COMPARISON_CLASS_P (arg0))
6431 if (TREE_CODE (type) == BOOLEAN_TYPE)
6433 arg0 = copy_node (arg0);
6434 TREE_TYPE (arg0) = type;
6437 else if (TREE_CODE (type) != INTEGER_TYPE)
6438 return fold (build3 (COND_EXPR, type, arg0,
6439 fold (build1 (code, type,
6441 fold (build1 (code, type,
6442 integer_zero_node))));
6445 else if (TREE_CODE_CLASS (code) == tcc_comparison
6446 && TREE_CODE (arg0) == COMPOUND_EXPR)
6447 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
6448 fold (build2 (code, type, TREE_OPERAND (arg0, 1), arg1)));
6449 else if (TREE_CODE_CLASS (code) == tcc_comparison
6450 && TREE_CODE (arg1) == COMPOUND_EXPR)
6451 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
6452 fold (build2 (code, type, arg0, TREE_OPERAND (arg1, 1))));
6453 else if (TREE_CODE_CLASS (code) == tcc_binary
6454 || TREE_CODE_CLASS (code) == tcc_comparison)
6456 if (TREE_CODE (arg0) == COMPOUND_EXPR)
6457 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
6458 fold (build2 (code, type, TREE_OPERAND (arg0, 1),
6460 if (TREE_CODE (arg1) == COMPOUND_EXPR
6461 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
6462 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
6463 fold (build2 (code, type,
6464 arg0, TREE_OPERAND (arg1, 1))));
6466 if (TREE_CODE (arg0) == COND_EXPR || COMPARISON_CLASS_P (arg0))
6468 tem = fold_binary_op_with_conditional_arg (code, type, arg0, arg1,
6469 /*cond_first_p=*/1);
6470 if (tem != NULL_TREE)
6474 if (TREE_CODE (arg1) == COND_EXPR || COMPARISON_CLASS_P (arg1))
6476 tem = fold_binary_op_with_conditional_arg (code, type, arg1, arg0,
6477 /*cond_first_p=*/0);
6478 if (tem != NULL_TREE)
6486 return fold (DECL_INITIAL (t));
6491 case FIX_TRUNC_EXPR:
6493 case FIX_FLOOR_EXPR:
6494 case FIX_ROUND_EXPR:
6495 if (TREE_TYPE (TREE_OPERAND (t, 0)) == type)
6496 return TREE_OPERAND (t, 0);
6498 /* Handle cases of two conversions in a row. */
6499 if (TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
6500 || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR)
6502 tree inside_type = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
6503 tree inter_type = TREE_TYPE (TREE_OPERAND (t, 0));
6504 int inside_int = INTEGRAL_TYPE_P (inside_type);
6505 int inside_ptr = POINTER_TYPE_P (inside_type);
6506 int inside_float = FLOAT_TYPE_P (inside_type);
6507 unsigned int inside_prec = TYPE_PRECISION (inside_type);
6508 int inside_unsignedp = TYPE_UNSIGNED (inside_type);
6509 int inter_int = INTEGRAL_TYPE_P (inter_type);
6510 int inter_ptr = POINTER_TYPE_P (inter_type);
6511 int inter_float = FLOAT_TYPE_P (inter_type);
6512 unsigned int inter_prec = TYPE_PRECISION (inter_type);
6513 int inter_unsignedp = TYPE_UNSIGNED (inter_type);
6514 int final_int = INTEGRAL_TYPE_P (type);
6515 int final_ptr = POINTER_TYPE_P (type);
6516 int final_float = FLOAT_TYPE_P (type);
6517 unsigned int final_prec = TYPE_PRECISION (type);
6518 int final_unsignedp = TYPE_UNSIGNED (type);
6520 /* In addition to the cases of two conversions in a row
6521 handled below, if we are converting something to its own
6522 type via an object of identical or wider precision, neither
6523 conversion is needed. */
6524 if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (type)
6525 && ((inter_int && final_int) || (inter_float && final_float))
6526 && inter_prec >= final_prec)
6527 return fold (build1 (code, type,
6528 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
6530 /* Likewise, if the intermediate and final types are either both
6531 float or both integer, we don't need the middle conversion if
6532 it is wider than the final type and doesn't change the signedness
6533 (for integers). Avoid this if the final type is a pointer
6534 since then we sometimes need the inner conversion. Likewise if
6535 the outer has a precision not equal to the size of its mode. */
6536 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
6537 || (inter_float && inside_float))
6538 && inter_prec >= inside_prec
6539 && (inter_float || inter_unsignedp == inside_unsignedp)
6540 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
6541 && TYPE_MODE (type) == TYPE_MODE (inter_type))
6543 return fold (build1 (code, type,
6544 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
6546 /* If we have a sign-extension of a zero-extended value, we can
6547 replace that by a single zero-extension. */
6548 if (inside_int && inter_int && final_int
6549 && inside_prec < inter_prec && inter_prec < final_prec
6550 && inside_unsignedp && !inter_unsignedp)
6551 return fold (build1 (code, type,
6552 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
6554 /* Two conversions in a row are not needed unless:
6555 - some conversion is floating-point (overstrict for now), or
6556 - the intermediate type is narrower than both initial and
6558 - the intermediate type and innermost type differ in signedness,
6559 and the outermost type is wider than the intermediate, or
6560 - the initial type is a pointer type and the precisions of the
6561 intermediate and final types differ, or
6562 - the final type is a pointer type and the precisions of the
6563 initial and intermediate types differ. */
6564 if (! inside_float && ! inter_float && ! final_float
6565 && (inter_prec > inside_prec || inter_prec > final_prec)
6566 && ! (inside_int && inter_int
6567 && inter_unsignedp != inside_unsignedp
6568 && inter_prec < final_prec)
6569 && ((inter_unsignedp && inter_prec > inside_prec)
6570 == (final_unsignedp && final_prec > inter_prec))
6571 && ! (inside_ptr && inter_prec != final_prec)
6572 && ! (final_ptr && inside_prec != inter_prec)
6573 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
6574 && TYPE_MODE (type) == TYPE_MODE (inter_type))
6576 return fold (build1 (code, type,
6577 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
6580 if (TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR
6581 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t, 0), 1))
6582 /* Detect assigning a bitfield. */
6583 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) == COMPONENT_REF
6584 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 1))))
6586 /* Don't leave an assignment inside a conversion
6587 unless assigning a bitfield. */
6588 tree prev = TREE_OPERAND (t, 0);
6589 tem = copy_node (t);
6590 TREE_OPERAND (tem, 0) = TREE_OPERAND (prev, 1);
6591 /* First do the assignment, then return converted constant. */
6592 tem = build2 (COMPOUND_EXPR, TREE_TYPE (tem), prev, fold (tem));
6593 TREE_NO_WARNING (tem) = 1;
6594 TREE_USED (tem) = 1;
6598 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
6599 constants (if x has signed type, the sign bit cannot be set
6600 in c). This folds extension into the BIT_AND_EXPR. */
6601 if (INTEGRAL_TYPE_P (type)
6602 && TREE_CODE (type) != BOOLEAN_TYPE
6603 && TREE_CODE (TREE_OPERAND (t, 0)) == BIT_AND_EXPR
6604 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 1)) == INTEGER_CST)
6606 tree and = TREE_OPERAND (t, 0);
6607 tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
6610 if (TYPE_UNSIGNED (TREE_TYPE (and))
6611 || (TYPE_PRECISION (type)
6612 <= TYPE_PRECISION (TREE_TYPE (and))))
6614 else if (TYPE_PRECISION (TREE_TYPE (and1))
6615 <= HOST_BITS_PER_WIDE_INT
6616 && host_integerp (and1, 1))
6618 unsigned HOST_WIDE_INT cst;
6620 cst = tree_low_cst (and1, 1);
6621 cst &= (HOST_WIDE_INT) -1
6622 << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
6623 change = (cst == 0);
6624 #ifdef LOAD_EXTEND_OP
6626 && !flag_syntax_only
6627 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
6630 tree uns = lang_hooks.types.unsigned_type (TREE_TYPE (and0));
6631 and0 = fold_convert (uns, and0);
6632 and1 = fold_convert (uns, and1);
6637 return fold (build2 (BIT_AND_EXPR, type,
6638 fold_convert (type, and0),
6639 fold_convert (type, and1)));
6642 /* Convert (T1)((T2)X op Y) into (T1)X op Y, for pointer types T1 and
6643 T2 being pointers to types of the same size. */
6644 if (POINTER_TYPE_P (TREE_TYPE (t))
6645 && BINARY_CLASS_P (arg0)
6646 && TREE_CODE (TREE_OPERAND (arg0, 0)) == NOP_EXPR
6647 && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 0))))
6649 tree arg00 = TREE_OPERAND (arg0, 0);
6650 tree t0 = TREE_TYPE (t);
6651 tree t1 = TREE_TYPE (arg00);
6652 tree tt0 = TREE_TYPE (t0);
6653 tree tt1 = TREE_TYPE (t1);
6654 tree s0 = TYPE_SIZE (tt0);
6655 tree s1 = TYPE_SIZE (tt1);
6657 if (s0 && s1 && operand_equal_p (s0, s1, OEP_ONLY_CONST))
6658 return build2 (TREE_CODE (arg0), t0, fold_convert (t0, arg00),
6659 TREE_OPERAND (arg0, 1));
6662 tem = fold_convert_const (code, type, arg0);
6663 return tem ? tem : t;
6665 case VIEW_CONVERT_EXPR:
6666 if (TREE_CODE (TREE_OPERAND (t, 0)) == VIEW_CONVERT_EXPR)
6667 return build1 (VIEW_CONVERT_EXPR, type,
6668 TREE_OPERAND (TREE_OPERAND (t, 0), 0));
6672 if (TREE_CODE (arg0) == CONSTRUCTOR
6673 && ! type_contains_placeholder_p (TREE_TYPE (arg0)))
6675 tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0));
6677 return TREE_VALUE (m);
6682 if (TREE_CONSTANT (t) != wins)
6684 tem = copy_node (t);
6685 TREE_CONSTANT (tem) = wins;
6686 TREE_INVARIANT (tem) = wins;
6692 if (negate_expr_p (arg0))
6693 return fold_convert (type, negate_expr (arg0));
6697 if (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST)
6698 return fold_abs_const (arg0, type);
6699 else if (TREE_CODE (arg0) == NEGATE_EXPR)
6700 return fold (build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0)));
6701 /* Convert fabs((double)float) into (double)fabsf(float). */
6702 else if (TREE_CODE (arg0) == NOP_EXPR
6703 && TREE_CODE (type) == REAL_TYPE)
6705 tree targ0 = strip_float_extensions (arg0);
6707 return fold_convert (type, fold (build1 (ABS_EXPR,
6711 else if (tree_expr_nonnegative_p (arg0))
6716 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
6717 return fold_convert (type, arg0);
6718 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
6719 return build2 (COMPLEX_EXPR, type,
6720 TREE_OPERAND (arg0, 0),
6721 negate_expr (TREE_OPERAND (arg0, 1)));
6722 else if (TREE_CODE (arg0) == COMPLEX_CST)
6723 return build_complex (type, TREE_REALPART (arg0),
6724 negate_expr (TREE_IMAGPART (arg0)));
6725 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
6726 return fold (build2 (TREE_CODE (arg0), type,
6727 fold (build1 (CONJ_EXPR, type,
6728 TREE_OPERAND (arg0, 0))),
6729 fold (build1 (CONJ_EXPR, type,
6730 TREE_OPERAND (arg0, 1)))));
6731 else if (TREE_CODE (arg0) == CONJ_EXPR)
6732 return TREE_OPERAND (arg0, 0);
6736 if (TREE_CODE (arg0) == INTEGER_CST)
6737 return fold_not_const (arg0, type);
6738 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
6739 return TREE_OPERAND (arg0, 0);
6743 /* A + (-B) -> A - B */
6744 if (TREE_CODE (arg1) == NEGATE_EXPR)
6745 return fold (build2 (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
6746 /* (-A) + B -> B - A */
6747 if (TREE_CODE (arg0) == NEGATE_EXPR
6748 && reorder_operands_p (TREE_OPERAND (arg0, 0), arg1))
6749 return fold (build2 (MINUS_EXPR, type, arg1, TREE_OPERAND (arg0, 0)));
6750 if (! FLOAT_TYPE_P (type))
6752 if (integer_zerop (arg1))
6753 return non_lvalue (fold_convert (type, arg0));
6755 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
6756 with a constant, and the two constants have no bits in common,
6757 we should treat this as a BIT_IOR_EXPR since this may produce more
6759 if (TREE_CODE (arg0) == BIT_AND_EXPR
6760 && TREE_CODE (arg1) == BIT_AND_EXPR
6761 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6762 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
6763 && integer_zerop (const_binop (BIT_AND_EXPR,
6764 TREE_OPERAND (arg0, 1),
6765 TREE_OPERAND (arg1, 1), 0)))
6767 code = BIT_IOR_EXPR;
6771 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
6772 (plus (plus (mult) (mult)) (foo)) so that we can
6773 take advantage of the factoring cases below. */
6774 if (((TREE_CODE (arg0) == PLUS_EXPR
6775 || TREE_CODE (arg0) == MINUS_EXPR)
6776 && TREE_CODE (arg1) == MULT_EXPR)
6777 || ((TREE_CODE (arg1) == PLUS_EXPR
6778 || TREE_CODE (arg1) == MINUS_EXPR)
6779 && TREE_CODE (arg0) == MULT_EXPR))
6781 tree parg0, parg1, parg, marg;
6782 enum tree_code pcode;
6784 if (TREE_CODE (arg1) == MULT_EXPR)
6785 parg = arg0, marg = arg1;
6787 parg = arg1, marg = arg0;
6788 pcode = TREE_CODE (parg);
6789 parg0 = TREE_OPERAND (parg, 0);
6790 parg1 = TREE_OPERAND (parg, 1);
6794 if (TREE_CODE (parg0) == MULT_EXPR
6795 && TREE_CODE (parg1) != MULT_EXPR)
6796 return fold (build2 (pcode, type,
6797 fold (build2 (PLUS_EXPR, type,
6798 fold_convert (type, parg0),
6799 fold_convert (type, marg))),
6800 fold_convert (type, parg1)));
6801 if (TREE_CODE (parg0) != MULT_EXPR
6802 && TREE_CODE (parg1) == MULT_EXPR)
6803 return fold (build2 (PLUS_EXPR, type,
6804 fold_convert (type, parg0),
6805 fold (build2 (pcode, type,
6806 fold_convert (type, marg),
6811 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR)
6813 tree arg00, arg01, arg10, arg11;
6814 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
6816 /* (A * C) + (B * C) -> (A+B) * C.
6817 We are most concerned about the case where C is a constant,
6818 but other combinations show up during loop reduction. Since
6819 it is not difficult, try all four possibilities. */
6821 arg00 = TREE_OPERAND (arg0, 0);
6822 arg01 = TREE_OPERAND (arg0, 1);
6823 arg10 = TREE_OPERAND (arg1, 0);
6824 arg11 = TREE_OPERAND (arg1, 1);
6827 if (operand_equal_p (arg01, arg11, 0))
6828 same = arg01, alt0 = arg00, alt1 = arg10;
6829 else if (operand_equal_p (arg00, arg10, 0))
6830 same = arg00, alt0 = arg01, alt1 = arg11;
6831 else if (operand_equal_p (arg00, arg11, 0))
6832 same = arg00, alt0 = arg01, alt1 = arg10;
6833 else if (operand_equal_p (arg01, arg10, 0))
6834 same = arg01, alt0 = arg00, alt1 = arg11;
6836 /* No identical multiplicands; see if we can find a common
6837 power-of-two factor in non-power-of-two multiplies. This
6838 can help in multi-dimensional array access. */
6839 else if (TREE_CODE (arg01) == INTEGER_CST
6840 && TREE_CODE (arg11) == INTEGER_CST
6841 && TREE_INT_CST_HIGH (arg01) == 0
6842 && TREE_INT_CST_HIGH (arg11) == 0)
6844 HOST_WIDE_INT int01, int11, tmp;
6845 int01 = TREE_INT_CST_LOW (arg01);
6846 int11 = TREE_INT_CST_LOW (arg11);
6848 /* Move min of absolute values to int11. */
6849 if ((int01 >= 0 ? int01 : -int01)
6850 < (int11 >= 0 ? int11 : -int11))
6852 tmp = int01, int01 = int11, int11 = tmp;
6853 alt0 = arg00, arg00 = arg10, arg10 = alt0;
6854 alt0 = arg01, arg01 = arg11, arg11 = alt0;
6857 if (exact_log2 (int11) > 0 && int01 % int11 == 0)
6859 alt0 = fold (build2 (MULT_EXPR, type, arg00,
6860 build_int_cst (NULL_TREE,
6868 return fold (build2 (MULT_EXPR, type,
6869 fold (build2 (PLUS_EXPR, type,
6870 fold_convert (type, alt0),
6871 fold_convert (type, alt1))),
6875 /* Try replacing &a[i1] + c * i2 with &a[i1 + i2], if c is step
6876 of the array. Loop optimizer sometimes produce this type of
6878 if (TREE_CODE (arg0) == ADDR_EXPR
6879 && TREE_CODE (arg1) == MULT_EXPR)
6881 tem = try_move_mult_to_index (type, PLUS_EXPR, arg0, arg1);
6885 else if (TREE_CODE (arg1) == ADDR_EXPR
6886 && TREE_CODE (arg0) == MULT_EXPR)
6888 tem = try_move_mult_to_index (type, PLUS_EXPR, arg1, arg0);
6895 /* See if ARG1 is zero and X + ARG1 reduces to X. */
6896 if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
6897 return non_lvalue (fold_convert (type, arg0));
6899 /* Likewise if the operands are reversed. */
6900 if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
6901 return non_lvalue (fold_convert (type, arg1));
6903 /* Convert X + -C into X - C. */
6904 if (TREE_CODE (arg1) == REAL_CST
6905 && REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1)))
6907 tem = fold_negate_const (arg1, type);
6908 if (!TREE_OVERFLOW (arg1) || !flag_trapping_math)
6909 return fold (build2 (MINUS_EXPR, type,
6910 fold_convert (type, arg0),
6911 fold_convert (type, tem)));
6914 /* Convert x+x into x*2.0. */
6915 if (operand_equal_p (arg0, arg1, 0)
6916 && SCALAR_FLOAT_TYPE_P (type))
6917 return fold (build2 (MULT_EXPR, type, arg0,
6918 build_real (type, dconst2)));
6920 /* Convert x*c+x into x*(c+1). */
6921 if (flag_unsafe_math_optimizations
6922 && TREE_CODE (arg0) == MULT_EXPR
6923 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
6924 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0, 1))
6925 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
6929 c = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
6930 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
6931 return fold (build2 (MULT_EXPR, type, arg1,
6932 build_real (type, c)));
6935 /* Convert x+x*c into x*(c+1). */
6936 if (flag_unsafe_math_optimizations
6937 && TREE_CODE (arg1) == MULT_EXPR
6938 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST
6939 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1, 1))
6940 && operand_equal_p (TREE_OPERAND (arg1, 0), arg0, 0))
6944 c = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
6945 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
6946 return fold (build2 (MULT_EXPR, type, arg0,
6947 build_real (type, c)));
6950 /* Convert x*c1+x*c2 into x*(c1+c2). */
6951 if (flag_unsafe_math_optimizations
6952 && TREE_CODE (arg0) == MULT_EXPR
6953 && TREE_CODE (arg1) == MULT_EXPR
6954 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
6955 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0, 1))
6956 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST
6957 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1, 1))
6958 && operand_equal_p (TREE_OPERAND (arg0, 0),
6959 TREE_OPERAND (arg1, 0), 0))
6961 REAL_VALUE_TYPE c1, c2;
6963 c1 = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
6964 c2 = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
6965 real_arithmetic (&c1, PLUS_EXPR, &c1, &c2);
6966 return fold (build2 (MULT_EXPR, type,
6967 TREE_OPERAND (arg0, 0),
6968 build_real (type, c1)));
6970 /* Convert a + (b*c + d*e) into (a + b*c) + d*e. */
6971 if (flag_unsafe_math_optimizations
6972 && TREE_CODE (arg1) == PLUS_EXPR
6973 && TREE_CODE (arg0) != MULT_EXPR)
6975 tree tree10 = TREE_OPERAND (arg1, 0);
6976 tree tree11 = TREE_OPERAND (arg1, 1);
6977 if (TREE_CODE (tree11) == MULT_EXPR
6978 && TREE_CODE (tree10) == MULT_EXPR)
6981 tree0 = fold (build2 (PLUS_EXPR, type, arg0, tree10));
6982 return fold (build2 (PLUS_EXPR, type, tree0, tree11));
6985 /* Convert (b*c + d*e) + a into b*c + (d*e +a). */
6986 if (flag_unsafe_math_optimizations
6987 && TREE_CODE (arg0) == PLUS_EXPR
6988 && TREE_CODE (arg1) != MULT_EXPR)
6990 tree tree00 = TREE_OPERAND (arg0, 0);
6991 tree tree01 = TREE_OPERAND (arg0, 1);
6992 if (TREE_CODE (tree01) == MULT_EXPR
6993 && TREE_CODE (tree00) == MULT_EXPR)
6996 tree0 = fold (build2 (PLUS_EXPR, type, tree01, arg1));
6997 return fold (build2 (PLUS_EXPR, type, tree00, tree0));
7003 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
7004 is a rotate of A by C1 bits. */
7005 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
7006 is a rotate of A by B bits. */
7008 enum tree_code code0, code1;
7009 code0 = TREE_CODE (arg0);
7010 code1 = TREE_CODE (arg1);
7011 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
7012 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
7013 && operand_equal_p (TREE_OPERAND (arg0, 0),
7014 TREE_OPERAND (arg1, 0), 0)
7015 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
7017 tree tree01, tree11;
7018 enum tree_code code01, code11;
7020 tree01 = TREE_OPERAND (arg0, 1);
7021 tree11 = TREE_OPERAND (arg1, 1);
7022 STRIP_NOPS (tree01);
7023 STRIP_NOPS (tree11);
7024 code01 = TREE_CODE (tree01);
7025 code11 = TREE_CODE (tree11);
7026 if (code01 == INTEGER_CST
7027 && code11 == INTEGER_CST
7028 && TREE_INT_CST_HIGH (tree01) == 0
7029 && TREE_INT_CST_HIGH (tree11) == 0
7030 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
7031 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
7032 return build2 (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
7033 code0 == LSHIFT_EXPR ? tree01 : tree11);
7034 else if (code11 == MINUS_EXPR)
7036 tree tree110, tree111;
7037 tree110 = TREE_OPERAND (tree11, 0);
7038 tree111 = TREE_OPERAND (tree11, 1);
7039 STRIP_NOPS (tree110);
7040 STRIP_NOPS (tree111);
7041 if (TREE_CODE (tree110) == INTEGER_CST
7042 && 0 == compare_tree_int (tree110,
7044 (TREE_TYPE (TREE_OPERAND
7046 && operand_equal_p (tree01, tree111, 0))
7047 return build2 ((code0 == LSHIFT_EXPR
7050 type, TREE_OPERAND (arg0, 0), tree01);
7052 else if (code01 == MINUS_EXPR)
7054 tree tree010, tree011;
7055 tree010 = TREE_OPERAND (tree01, 0);
7056 tree011 = TREE_OPERAND (tree01, 1);
7057 STRIP_NOPS (tree010);
7058 STRIP_NOPS (tree011);
7059 if (TREE_CODE (tree010) == INTEGER_CST
7060 && 0 == compare_tree_int (tree010,
7062 (TREE_TYPE (TREE_OPERAND
7064 && operand_equal_p (tree11, tree011, 0))
7065 return build2 ((code0 != LSHIFT_EXPR
7068 type, TREE_OPERAND (arg0, 0), tree11);
7074 /* In most languages, can't associate operations on floats through
7075 parentheses. Rather than remember where the parentheses were, we
7076 don't associate floats at all, unless the user has specified
7077 -funsafe-math-optimizations. */
7080 && (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
7082 tree var0, con0, lit0, minus_lit0;
7083 tree var1, con1, lit1, minus_lit1;
7085 /* Split both trees into variables, constants, and literals. Then
7086 associate each group together, the constants with literals,
7087 then the result with variables. This increases the chances of
7088 literals being recombined later and of generating relocatable
7089 expressions for the sum of a constant and literal. */
7090 var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
7091 var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
7092 code == MINUS_EXPR);
7094 /* Only do something if we found more than two objects. Otherwise,
7095 nothing has changed and we risk infinite recursion. */
7096 if (2 < ((var0 != 0) + (var1 != 0)
7097 + (con0 != 0) + (con1 != 0)
7098 + (lit0 != 0) + (lit1 != 0)
7099 + (minus_lit0 != 0) + (minus_lit1 != 0)))
7101 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
7102 if (code == MINUS_EXPR)
7105 var0 = associate_trees (var0, var1, code, type);
7106 con0 = associate_trees (con0, con1, code, type);
7107 lit0 = associate_trees (lit0, lit1, code, type);
7108 minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
7110 /* Preserve the MINUS_EXPR if the negative part of the literal is
7111 greater than the positive part. Otherwise, the multiplicative
7112 folding code (i.e extract_muldiv) may be fooled in case
7113 unsigned constants are subtracted, like in the following
7114 example: ((X*2 + 4) - 8U)/2. */
7115 if (minus_lit0 && lit0)
7117 if (TREE_CODE (lit0) == INTEGER_CST
7118 && TREE_CODE (minus_lit0) == INTEGER_CST
7119 && tree_int_cst_lt (lit0, minus_lit0))
7121 minus_lit0 = associate_trees (minus_lit0, lit0,
7127 lit0 = associate_trees (lit0, minus_lit0,
7135 return fold_convert (type,
7136 associate_trees (var0, minus_lit0,
7140 con0 = associate_trees (con0, minus_lit0,
7142 return fold_convert (type,
7143 associate_trees (var0, con0,
7148 con0 = associate_trees (con0, lit0, code, type);
7149 return fold_convert (type, associate_trees (var0, con0,
7156 t1 = const_binop (code, arg0, arg1, 0);
7157 if (t1 != NULL_TREE)
7159 /* The return value should always have
7160 the same type as the original expression. */
7161 if (TREE_TYPE (t1) != type)
7162 t1 = fold_convert (type, t1);
7169 /* A - (-B) -> A + B */
7170 if (TREE_CODE (arg1) == NEGATE_EXPR)
7171 return fold (build2 (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
7172 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
7173 if (TREE_CODE (arg0) == NEGATE_EXPR
7174 && (FLOAT_TYPE_P (type)
7175 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv))
7176 && negate_expr_p (arg1)
7177 && reorder_operands_p (arg0, arg1))
7178 return fold (build2 (MINUS_EXPR, type, negate_expr (arg1),
7179 TREE_OPERAND (arg0, 0)));
7181 if (! FLOAT_TYPE_P (type))
7183 if (! wins && integer_zerop (arg0))
7184 return negate_expr (fold_convert (type, arg1));
7185 if (integer_zerop (arg1))
7186 return non_lvalue (fold_convert (type, arg0));
7188 /* Fold A - (A & B) into ~B & A. */
7189 if (!TREE_SIDE_EFFECTS (arg0)
7190 && TREE_CODE (arg1) == BIT_AND_EXPR)
7192 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
7193 return fold (build2 (BIT_AND_EXPR, type,
7194 fold (build1 (BIT_NOT_EXPR, type,
7195 TREE_OPERAND (arg1, 0))),
7197 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
7198 return fold (build2 (BIT_AND_EXPR, type,
7199 fold (build1 (BIT_NOT_EXPR, type,
7200 TREE_OPERAND (arg1, 1))),
7204 /* Fold (A & ~B) - (A & B) into (A ^ B) - B, where B is
7205 any power of 2 minus 1. */
7206 if (TREE_CODE (arg0) == BIT_AND_EXPR
7207 && TREE_CODE (arg1) == BIT_AND_EXPR
7208 && operand_equal_p (TREE_OPERAND (arg0, 0),
7209 TREE_OPERAND (arg1, 0), 0))
7211 tree mask0 = TREE_OPERAND (arg0, 1);
7212 tree mask1 = TREE_OPERAND (arg1, 1);
7213 tree tem = fold (build1 (BIT_NOT_EXPR, type, mask0));
7215 if (operand_equal_p (tem, mask1, 0))
7217 tem = fold (build2 (BIT_XOR_EXPR, type,
7218 TREE_OPERAND (arg0, 0), mask1));
7219 return fold (build2 (MINUS_EXPR, type, tem, mask1));
7224 /* See if ARG1 is zero and X - ARG1 reduces to X. */
7225 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
7226 return non_lvalue (fold_convert (type, arg0));
7228 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
7229 ARG0 is zero and X + ARG0 reduces to X, since that would mean
7230 (-ARG1 + ARG0) reduces to -ARG1. */
7231 else if (!wins && fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
7232 return negate_expr (fold_convert (type, arg1));
7234 /* Fold &x - &x. This can happen from &x.foo - &x.
7235 This is unsafe for certain floats even in non-IEEE formats.
7236 In IEEE, it is unsafe because it does wrong for NaNs.
7237 Also note that operand_equal_p is always false if an operand
7240 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
7241 && operand_equal_p (arg0, arg1, 0))
7242 return fold_convert (type, integer_zero_node);
7244 /* A - B -> A + (-B) if B is easily negatable. */
7245 if (!wins && negate_expr_p (arg1)
7246 && ((FLOAT_TYPE_P (type)
7247 /* Avoid this transformation if B is a positive REAL_CST. */
7248 && (TREE_CODE (arg1) != REAL_CST
7249 || REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1))))
7250 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv)))
7251 return fold (build2 (PLUS_EXPR, type, arg0, negate_expr (arg1)));
7253 /* Try folding difference of addresses. */
7257 if ((TREE_CODE (arg0) == ADDR_EXPR
7258 || TREE_CODE (arg1) == ADDR_EXPR)
7259 && ptr_difference_const (arg0, arg1, &diff))
7260 return build_int_cst_type (type, diff);
7263 /* Try replacing &a[i1] - c * i2 with &a[i1 - i2], if c is step
7264 of the array. Loop optimizer sometimes produce this type of
7266 if (TREE_CODE (arg0) == ADDR_EXPR
7267 && TREE_CODE (arg1) == MULT_EXPR)
7269 tem = try_move_mult_to_index (type, MINUS_EXPR, arg0, arg1);
7274 if (TREE_CODE (arg0) == MULT_EXPR
7275 && TREE_CODE (arg1) == MULT_EXPR
7276 && (!FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
7278 /* (A * C) - (B * C) -> (A-B) * C. */
7279 if (operand_equal_p (TREE_OPERAND (arg0, 1),
7280 TREE_OPERAND (arg1, 1), 0))
7281 return fold (build2 (MULT_EXPR, type,
7282 fold (build2 (MINUS_EXPR, type,
7283 TREE_OPERAND (arg0, 0),
7284 TREE_OPERAND (arg1, 0))),
7285 TREE_OPERAND (arg0, 1)));
7286 /* (A * C1) - (A * C2) -> A * (C1-C2). */
7287 if (operand_equal_p (TREE_OPERAND (arg0, 0),
7288 TREE_OPERAND (arg1, 0), 0))
7289 return fold (build2 (MULT_EXPR, type,
7290 TREE_OPERAND (arg0, 0),
7291 fold (build2 (MINUS_EXPR, type,
7292 TREE_OPERAND (arg0, 1),
7293 TREE_OPERAND (arg1, 1)))));
7299 /* (-A) * (-B) -> A * B */
7300 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
7301 return fold (build2 (MULT_EXPR, type,
7302 TREE_OPERAND (arg0, 0),
7303 negate_expr (arg1)));
7304 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
7305 return fold (build2 (MULT_EXPR, type,
7307 TREE_OPERAND (arg1, 0)));
7309 if (! FLOAT_TYPE_P (type))
7311 if (integer_zerop (arg1))
7312 return omit_one_operand (type, arg1, arg0);
7313 if (integer_onep (arg1))
7314 return non_lvalue (fold_convert (type, arg0));
7316 /* (a * (1 << b)) is (a << b) */
7317 if (TREE_CODE (arg1) == LSHIFT_EXPR
7318 && integer_onep (TREE_OPERAND (arg1, 0)))
7319 return fold (build2 (LSHIFT_EXPR, type, arg0,
7320 TREE_OPERAND (arg1, 1)));
7321 if (TREE_CODE (arg0) == LSHIFT_EXPR
7322 && integer_onep (TREE_OPERAND (arg0, 0)))
7323 return fold (build2 (LSHIFT_EXPR, type, arg1,
7324 TREE_OPERAND (arg0, 1)));
7326 if (TREE_CODE (arg1) == INTEGER_CST
7327 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0),
7328 fold_convert (type, arg1),
7330 return fold_convert (type, tem);
7335 /* Maybe fold x * 0 to 0. The expressions aren't the same
7336 when x is NaN, since x * 0 is also NaN. Nor are they the
7337 same in modes with signed zeros, since multiplying a
7338 negative value by 0 gives -0, not +0. */
7339 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
7340 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
7341 && real_zerop (arg1))
7342 return omit_one_operand (type, arg1, arg0);
7343 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
7344 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
7345 && real_onep (arg1))
7346 return non_lvalue (fold_convert (type, arg0));
7348 /* Transform x * -1.0 into -x. */
7349 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
7350 && real_minus_onep (arg1))
7351 return fold_convert (type, negate_expr (arg0));
7353 /* Convert (C1/X)*C2 into (C1*C2)/X. */
7354 if (flag_unsafe_math_optimizations
7355 && TREE_CODE (arg0) == RDIV_EXPR
7356 && TREE_CODE (arg1) == REAL_CST
7357 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST)
7359 tree tem = const_binop (MULT_EXPR, TREE_OPERAND (arg0, 0),
7362 return fold (build2 (RDIV_EXPR, type, tem,
7363 TREE_OPERAND (arg0, 1)));
7366 if (flag_unsafe_math_optimizations)
7368 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
7369 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
7371 /* Optimizations of root(...)*root(...). */
7372 if (fcode0 == fcode1 && BUILTIN_ROOT_P (fcode0))
7374 tree rootfn, arg, arglist;
7375 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
7376 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
7378 /* Optimize sqrt(x)*sqrt(x) as x. */
7379 if (BUILTIN_SQRT_P (fcode0)
7380 && operand_equal_p (arg00, arg10, 0)
7381 && ! HONOR_SNANS (TYPE_MODE (type)))
7384 /* Optimize root(x)*root(y) as root(x*y). */
7385 rootfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7386 arg = fold (build2 (MULT_EXPR, type, arg00, arg10));
7387 arglist = build_tree_list (NULL_TREE, arg);
7388 return build_function_call_expr (rootfn, arglist);
7391 /* Optimize expN(x)*expN(y) as expN(x+y). */
7392 if (fcode0 == fcode1 && BUILTIN_EXPONENT_P (fcode0))
7394 tree expfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7395 tree arg = build2 (PLUS_EXPR, type,
7396 TREE_VALUE (TREE_OPERAND (arg0, 1)),
7397 TREE_VALUE (TREE_OPERAND (arg1, 1)));
7398 tree arglist = build_tree_list (NULL_TREE, fold (arg));
7399 return build_function_call_expr (expfn, arglist);
7402 /* Optimizations of pow(...)*pow(...). */
7403 if ((fcode0 == BUILT_IN_POW && fcode1 == BUILT_IN_POW)
7404 || (fcode0 == BUILT_IN_POWF && fcode1 == BUILT_IN_POWF)
7405 || (fcode0 == BUILT_IN_POWL && fcode1 == BUILT_IN_POWL))
7407 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
7408 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
7410 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
7411 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
7414 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
7415 if (operand_equal_p (arg01, arg11, 0))
7417 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7418 tree arg = build2 (MULT_EXPR, type, arg00, arg10);
7419 tree arglist = tree_cons (NULL_TREE, fold (arg),
7420 build_tree_list (NULL_TREE,
7422 return build_function_call_expr (powfn, arglist);
7425 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
7426 if (operand_equal_p (arg00, arg10, 0))
7428 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7429 tree arg = fold (build2 (PLUS_EXPR, type, arg01, arg11));
7430 tree arglist = tree_cons (NULL_TREE, arg00,
7431 build_tree_list (NULL_TREE,
7433 return build_function_call_expr (powfn, arglist);
7437 /* Optimize tan(x)*cos(x) as sin(x). */
7438 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_COS)
7439 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_COSF)
7440 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_COSL)
7441 || (fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_TAN)
7442 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_TANF)
7443 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_TANL))
7444 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
7445 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
7447 tree sinfn = mathfn_built_in (type, BUILT_IN_SIN);
7449 if (sinfn != NULL_TREE)
7450 return build_function_call_expr (sinfn,
7451 TREE_OPERAND (arg0, 1));
7454 /* Optimize x*pow(x,c) as pow(x,c+1). */
7455 if (fcode1 == BUILT_IN_POW
7456 || fcode1 == BUILT_IN_POWF
7457 || fcode1 == BUILT_IN_POWL)
7459 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
7460 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
7462 if (TREE_CODE (arg11) == REAL_CST
7463 && ! TREE_CONSTANT_OVERFLOW (arg11)
7464 && operand_equal_p (arg0, arg10, 0))
7466 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
7470 c = TREE_REAL_CST (arg11);
7471 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
7472 arg = build_real (type, c);
7473 arglist = build_tree_list (NULL_TREE, arg);
7474 arglist = tree_cons (NULL_TREE, arg0, arglist);
7475 return build_function_call_expr (powfn, arglist);
7479 /* Optimize pow(x,c)*x as pow(x,c+1). */
7480 if (fcode0 == BUILT_IN_POW
7481 || fcode0 == BUILT_IN_POWF
7482 || fcode0 == BUILT_IN_POWL)
7484 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
7485 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
7487 if (TREE_CODE (arg01) == REAL_CST
7488 && ! TREE_CONSTANT_OVERFLOW (arg01)
7489 && operand_equal_p (arg1, arg00, 0))
7491 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7495 c = TREE_REAL_CST (arg01);
7496 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
7497 arg = build_real (type, c);
7498 arglist = build_tree_list (NULL_TREE, arg);
7499 arglist = tree_cons (NULL_TREE, arg1, arglist);
7500 return build_function_call_expr (powfn, arglist);
7504 /* Optimize x*x as pow(x,2.0), which is expanded as x*x. */
7506 && operand_equal_p (arg0, arg1, 0))
7508 tree powfn = mathfn_built_in (type, BUILT_IN_POW);
7512 tree arg = build_real (type, dconst2);
7513 tree arglist = build_tree_list (NULL_TREE, arg);
7514 arglist = tree_cons (NULL_TREE, arg0, arglist);
7515 return build_function_call_expr (powfn, arglist);
7524 if (integer_all_onesp (arg1))
7525 return omit_one_operand (type, arg1, arg0);
7526 if (integer_zerop (arg1))
7527 return non_lvalue (fold_convert (type, arg0));
7528 if (operand_equal_p (arg0, arg1, 0))
7529 return non_lvalue (fold_convert (type, arg0));
7532 if (TREE_CODE (arg0) == BIT_NOT_EXPR
7533 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
7535 t1 = build_int_cst (type, -1);
7536 t1 = force_fit_type (t1, 0, false, false);
7537 return omit_one_operand (type, t1, arg1);
7541 if (TREE_CODE (arg1) == BIT_NOT_EXPR
7542 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
7544 t1 = build_int_cst (type, -1);
7545 t1 = force_fit_type (t1, 0, false, false);
7546 return omit_one_operand (type, t1, arg0);
7549 t1 = distribute_bit_expr (code, type, arg0, arg1);
7550 if (t1 != NULL_TREE)
7553 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
7555 This results in more efficient code for machines without a NAND
7556 instruction. Combine will canonicalize to the first form
7557 which will allow use of NAND instructions provided by the
7558 backend if they exist. */
7559 if (TREE_CODE (arg0) == BIT_NOT_EXPR
7560 && TREE_CODE (arg1) == BIT_NOT_EXPR)
7562 return fold (build1 (BIT_NOT_EXPR, type,
7563 build2 (BIT_AND_EXPR, type,
7564 TREE_OPERAND (arg0, 0),
7565 TREE_OPERAND (arg1, 0))));
7568 /* See if this can be simplified into a rotate first. If that
7569 is unsuccessful continue in the association code. */
7573 if (integer_zerop (arg1))
7574 return non_lvalue (fold_convert (type, arg0));
7575 if (integer_all_onesp (arg1))
7576 return fold (build1 (BIT_NOT_EXPR, type, arg0));
7577 if (operand_equal_p (arg0, arg1, 0))
7578 return omit_one_operand (type, integer_zero_node, arg0);
7581 if (TREE_CODE (arg0) == BIT_NOT_EXPR
7582 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
7584 t1 = build_int_cst (type, -1);
7585 t1 = force_fit_type (t1, 0, false, false);
7586 return omit_one_operand (type, t1, arg1);
7590 if (TREE_CODE (arg1) == BIT_NOT_EXPR
7591 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
7593 t1 = build_int_cst (type, -1);
7594 t1 = force_fit_type (t1, 0, false, false);
7595 return omit_one_operand (type, t1, arg0);
7598 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
7599 with a constant, and the two constants have no bits in common,
7600 we should treat this as a BIT_IOR_EXPR since this may produce more
7602 if (TREE_CODE (arg0) == BIT_AND_EXPR
7603 && TREE_CODE (arg1) == BIT_AND_EXPR
7604 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7605 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
7606 && integer_zerop (const_binop (BIT_AND_EXPR,
7607 TREE_OPERAND (arg0, 1),
7608 TREE_OPERAND (arg1, 1), 0)))
7610 code = BIT_IOR_EXPR;
7614 /* See if this can be simplified into a rotate first. If that
7615 is unsuccessful continue in the association code. */
7619 if (integer_all_onesp (arg1))
7620 return non_lvalue (fold_convert (type, arg0));
7621 if (integer_zerop (arg1))
7622 return omit_one_operand (type, arg1, arg0);
7623 if (operand_equal_p (arg0, arg1, 0))
7624 return non_lvalue (fold_convert (type, arg0));
7626 /* ~X & X is always zero. */
7627 if (TREE_CODE (arg0) == BIT_NOT_EXPR
7628 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
7629 return omit_one_operand (type, integer_zero_node, arg1);
7631 /* X & ~X is always zero. */
7632 if (TREE_CODE (arg1) == BIT_NOT_EXPR
7633 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
7634 return omit_one_operand (type, integer_zero_node, arg0);
7636 t1 = distribute_bit_expr (code, type, arg0, arg1);
7637 if (t1 != NULL_TREE)
7639 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
7640 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
7641 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
7644 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
7646 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
7647 && (~TREE_INT_CST_LOW (arg1)
7648 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
7649 return fold_convert (type, TREE_OPERAND (arg0, 0));
7652 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
7654 This results in more efficient code for machines without a NOR
7655 instruction. Combine will canonicalize to the first form
7656 which will allow use of NOR instructions provided by the
7657 backend if they exist. */
7658 if (TREE_CODE (arg0) == BIT_NOT_EXPR
7659 && TREE_CODE (arg1) == BIT_NOT_EXPR)
7661 return fold (build1 (BIT_NOT_EXPR, type,
7662 build2 (BIT_IOR_EXPR, type,
7663 TREE_OPERAND (arg0, 0),
7664 TREE_OPERAND (arg1, 0))));
7670 /* Don't touch a floating-point divide by zero unless the mode
7671 of the constant can represent infinity. */
7672 if (TREE_CODE (arg1) == REAL_CST
7673 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
7674 && real_zerop (arg1))
7677 /* (-A) / (-B) -> A / B */
7678 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
7679 return fold (build2 (RDIV_EXPR, type,
7680 TREE_OPERAND (arg0, 0),
7681 negate_expr (arg1)));
7682 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
7683 return fold (build2 (RDIV_EXPR, type,
7685 TREE_OPERAND (arg1, 0)));
7687 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
7688 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
7689 && real_onep (arg1))
7690 return non_lvalue (fold_convert (type, arg0));
7692 /* In IEEE floating point, x/-1 is not equivalent to -x for snans. */
7693 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
7694 && real_minus_onep (arg1))
7695 return non_lvalue (fold_convert (type, negate_expr (arg0)));
7697 /* If ARG1 is a constant, we can convert this to a multiply by the
7698 reciprocal. This does not have the same rounding properties,
7699 so only do this if -funsafe-math-optimizations. We can actually
7700 always safely do it if ARG1 is a power of two, but it's hard to
7701 tell if it is or not in a portable manner. */
7702 if (TREE_CODE (arg1) == REAL_CST)
7704 if (flag_unsafe_math_optimizations
7705 && 0 != (tem = const_binop (code, build_real (type, dconst1),
7707 return fold (build2 (MULT_EXPR, type, arg0, tem));
7708 /* Find the reciprocal if optimizing and the result is exact. */
7712 r = TREE_REAL_CST (arg1);
7713 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
7715 tem = build_real (type, r);
7716 return fold (build2 (MULT_EXPR, type, arg0, tem));
7720 /* Convert A/B/C to A/(B*C). */
7721 if (flag_unsafe_math_optimizations
7722 && TREE_CODE (arg0) == RDIV_EXPR)
7723 return fold (build2 (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
7724 fold (build2 (MULT_EXPR, type,
7725 TREE_OPERAND (arg0, 1), arg1))));
7727 /* Convert A/(B/C) to (A/B)*C. */
7728 if (flag_unsafe_math_optimizations
7729 && TREE_CODE (arg1) == RDIV_EXPR)
7730 return fold (build2 (MULT_EXPR, type,
7731 fold (build2 (RDIV_EXPR, type, arg0,
7732 TREE_OPERAND (arg1, 0))),
7733 TREE_OPERAND (arg1, 1)));
7735 /* Convert C1/(X*C2) into (C1/C2)/X. */
7736 if (flag_unsafe_math_optimizations
7737 && TREE_CODE (arg1) == MULT_EXPR
7738 && TREE_CODE (arg0) == REAL_CST
7739 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
7741 tree tem = const_binop (RDIV_EXPR, arg0,
7742 TREE_OPERAND (arg1, 1), 0);
7744 return fold (build2 (RDIV_EXPR, type, tem,
7745 TREE_OPERAND (arg1, 0)));
7748 if (flag_unsafe_math_optimizations)
7750 enum built_in_function fcode = builtin_mathfn_code (arg1);
7751 /* Optimize x/expN(y) into x*expN(-y). */
7752 if (BUILTIN_EXPONENT_P (fcode))
7754 tree expfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
7755 tree arg = negate_expr (TREE_VALUE (TREE_OPERAND (arg1, 1)));
7756 tree arglist = build_tree_list (NULL_TREE,
7757 fold_convert (type, arg));
7758 arg1 = build_function_call_expr (expfn, arglist);
7759 return fold (build2 (MULT_EXPR, type, arg0, arg1));
7762 /* Optimize x/pow(y,z) into x*pow(y,-z). */
7763 if (fcode == BUILT_IN_POW
7764 || fcode == BUILT_IN_POWF
7765 || fcode == BUILT_IN_POWL)
7767 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
7768 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
7769 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1, 1)));
7770 tree neg11 = fold_convert (type, negate_expr (arg11));
7771 tree arglist = tree_cons(NULL_TREE, arg10,
7772 build_tree_list (NULL_TREE, neg11));
7773 arg1 = build_function_call_expr (powfn, arglist);
7774 return fold (build2 (MULT_EXPR, type, arg0, arg1));
7778 if (flag_unsafe_math_optimizations)
7780 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
7781 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
7783 /* Optimize sin(x)/cos(x) as tan(x). */
7784 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_COS)
7785 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_COSF)
7786 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_COSL))
7787 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
7788 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
7790 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
7792 if (tanfn != NULL_TREE)
7793 return build_function_call_expr (tanfn,
7794 TREE_OPERAND (arg0, 1));
7797 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
7798 if (((fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_SIN)
7799 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_SINF)
7800 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_SINL))
7801 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
7802 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
7804 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
7806 if (tanfn != NULL_TREE)
7808 tree tmp = TREE_OPERAND (arg0, 1);
7809 tmp = build_function_call_expr (tanfn, tmp);
7810 return fold (build2 (RDIV_EXPR, type,
7811 build_real (type, dconst1), tmp));
7815 /* Optimize pow(x,c)/x as pow(x,c-1). */
7816 if (fcode0 == BUILT_IN_POW
7817 || fcode0 == BUILT_IN_POWF
7818 || fcode0 == BUILT_IN_POWL)
7820 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
7821 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0, 1)));
7822 if (TREE_CODE (arg01) == REAL_CST
7823 && ! TREE_CONSTANT_OVERFLOW (arg01)
7824 && operand_equal_p (arg1, arg00, 0))
7826 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7830 c = TREE_REAL_CST (arg01);
7831 real_arithmetic (&c, MINUS_EXPR, &c, &dconst1);
7832 arg = build_real (type, c);
7833 arglist = build_tree_list (NULL_TREE, arg);
7834 arglist = tree_cons (NULL_TREE, arg1, arglist);
7835 return build_function_call_expr (powfn, arglist);
7841 case TRUNC_DIV_EXPR:
7842 case ROUND_DIV_EXPR:
7843 case FLOOR_DIV_EXPR:
7845 case EXACT_DIV_EXPR:
7846 if (integer_onep (arg1))
7847 return non_lvalue (fold_convert (type, arg0));
7848 if (integer_zerop (arg1))
7851 if (!TYPE_UNSIGNED (type)
7852 && TREE_CODE (arg1) == INTEGER_CST
7853 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
7854 && TREE_INT_CST_HIGH (arg1) == -1)
7855 return fold_convert (type, negate_expr (arg0));
7857 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
7858 operation, EXACT_DIV_EXPR.
7860 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
7861 At one time others generated faster code, it's not clear if they do
7862 after the last round to changes to the DIV code in expmed.c. */
7863 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
7864 && multiple_of_p (type, arg0, arg1))
7865 return fold (build2 (EXACT_DIV_EXPR, type, arg0, arg1));
7867 if (TREE_CODE (arg1) == INTEGER_CST
7868 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
7870 return fold_convert (type, tem);
7875 case FLOOR_MOD_EXPR:
7876 case ROUND_MOD_EXPR:
7877 case TRUNC_MOD_EXPR:
7878 if (integer_onep (arg1))
7879 return omit_one_operand (type, integer_zero_node, arg0);
7880 if (integer_zerop (arg1))
7883 /* X % -1 is zero. */
7884 if (!TYPE_UNSIGNED (type)
7885 && TREE_CODE (arg1) == INTEGER_CST
7886 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
7887 && TREE_INT_CST_HIGH (arg1) == -1)
7888 return omit_one_operand (type, integer_zero_node, arg0);
7890 /* Optimize unsigned TRUNC_MOD_EXPR by a power of two into a
7891 BIT_AND_EXPR, i.e. "X % C" into "X & C2". */
7892 if (code == TRUNC_MOD_EXPR
7893 && TYPE_UNSIGNED (type)
7894 && integer_pow2p (arg1))
7896 unsigned HOST_WIDE_INT high, low;
7900 l = tree_log2 (arg1);
7901 if (l >= HOST_BITS_PER_WIDE_INT)
7903 high = ((unsigned HOST_WIDE_INT) 1
7904 << (l - HOST_BITS_PER_WIDE_INT)) - 1;
7910 low = ((unsigned HOST_WIDE_INT) 1 << l) - 1;
7913 mask = build_int_cst_wide (type, low, high);
7914 return fold (build2 (BIT_AND_EXPR, type,
7915 fold_convert (type, arg0), mask));
7918 /* X % -C is the same as X % C. */
7919 if (code == TRUNC_MOD_EXPR
7920 && !TYPE_UNSIGNED (type)
7921 && TREE_CODE (arg1) == INTEGER_CST
7922 && TREE_INT_CST_HIGH (arg1) < 0
7924 /* Avoid this transformation if C is INT_MIN, i.e. C == -C. */
7925 && !sign_bit_p (arg1, arg1))
7926 return fold (build2 (code, type, fold_convert (type, arg0),
7927 fold_convert (type, negate_expr (arg1))));
7929 /* X % -Y is the same as X % Y. */
7930 if (code == TRUNC_MOD_EXPR
7931 && !TYPE_UNSIGNED (type)
7932 && TREE_CODE (arg1) == NEGATE_EXPR
7934 return fold (build2 (code, type, fold_convert (type, arg0),
7935 fold_convert (type, TREE_OPERAND (arg1, 0))));
7937 if (TREE_CODE (arg1) == INTEGER_CST
7938 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
7940 return fold_convert (type, tem);
7946 if (integer_all_onesp (arg0))
7947 return omit_one_operand (type, arg0, arg1);
7951 /* Optimize -1 >> x for arithmetic right shifts. */
7952 if (integer_all_onesp (arg0) && !TYPE_UNSIGNED (type))
7953 return omit_one_operand (type, arg0, arg1);
7954 /* ... fall through ... */
7958 if (integer_zerop (arg1))
7959 return non_lvalue (fold_convert (type, arg0));
7960 if (integer_zerop (arg0))
7961 return omit_one_operand (type, arg0, arg1);
7963 /* Since negative shift count is not well-defined,
7964 don't try to compute it in the compiler. */
7965 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
7967 /* Rewrite an LROTATE_EXPR by a constant into an
7968 RROTATE_EXPR by a new constant. */
7969 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
7971 tree tem = build_int_cst (NULL_TREE,
7972 GET_MODE_BITSIZE (TYPE_MODE (type)));
7973 tem = fold_convert (TREE_TYPE (arg1), tem);
7974 tem = const_binop (MINUS_EXPR, tem, arg1, 0);
7975 return fold (build2 (RROTATE_EXPR, type, arg0, tem));
7978 /* If we have a rotate of a bit operation with the rotate count and
7979 the second operand of the bit operation both constant,
7980 permute the two operations. */
7981 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
7982 && (TREE_CODE (arg0) == BIT_AND_EXPR
7983 || TREE_CODE (arg0) == BIT_IOR_EXPR
7984 || TREE_CODE (arg0) == BIT_XOR_EXPR)
7985 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
7986 return fold (build2 (TREE_CODE (arg0), type,
7987 fold (build2 (code, type,
7988 TREE_OPERAND (arg0, 0), arg1)),
7989 fold (build2 (code, type,
7990 TREE_OPERAND (arg0, 1), arg1))));
7992 /* Two consecutive rotates adding up to the width of the mode can
7994 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
7995 && TREE_CODE (arg0) == RROTATE_EXPR
7996 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7997 && TREE_INT_CST_HIGH (arg1) == 0
7998 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
7999 && ((TREE_INT_CST_LOW (arg1)
8000 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
8001 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type))))
8002 return TREE_OPERAND (arg0, 0);
8007 if (operand_equal_p (arg0, arg1, 0))
8008 return omit_one_operand (type, arg0, arg1);
8009 if (INTEGRAL_TYPE_P (type)
8010 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
8011 return omit_one_operand (type, arg1, arg0);
8015 if (operand_equal_p (arg0, arg1, 0))
8016 return omit_one_operand (type, arg0, arg1);
8017 if (INTEGRAL_TYPE_P (type)
8018 && TYPE_MAX_VALUE (type)
8019 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
8020 return omit_one_operand (type, arg1, arg0);
8023 case TRUTH_NOT_EXPR:
8024 /* The argument to invert_truthvalue must have Boolean type. */
8025 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
8026 arg0 = fold_convert (boolean_type_node, arg0);
8028 /* Note that the operand of this must be an int
8029 and its values must be 0 or 1.
8030 ("true" is a fixed value perhaps depending on the language,
8031 but we don't handle values other than 1 correctly yet.) */
8032 tem = invert_truthvalue (arg0);
8033 /* Avoid infinite recursion. */
8034 if (TREE_CODE (tem) == TRUTH_NOT_EXPR)
8036 return fold_convert (type, tem);
8038 case TRUTH_ANDIF_EXPR:
8039 /* Note that the operands of this must be ints
8040 and their values must be 0 or 1.
8041 ("true" is a fixed value perhaps depending on the language.) */
8042 /* If first arg is constant zero, return it. */
8043 if (integer_zerop (arg0))
8044 return fold_convert (type, arg0);
8045 case TRUTH_AND_EXPR:
8046 /* If either arg is constant true, drop it. */
8047 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
8048 return non_lvalue (fold_convert (type, arg1));
8049 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
8050 /* Preserve sequence points. */
8051 && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
8052 return non_lvalue (fold_convert (type, arg0));
8053 /* If second arg is constant zero, result is zero, but first arg
8054 must be evaluated. */
8055 if (integer_zerop (arg1))
8056 return omit_one_operand (type, arg1, arg0);
8057 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
8058 case will be handled here. */
8059 if (integer_zerop (arg0))
8060 return omit_one_operand (type, arg0, arg1);
8062 /* !X && X is always false. */
8063 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
8064 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
8065 return omit_one_operand (type, integer_zero_node, arg1);
8066 /* X && !X is always false. */
8067 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
8068 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
8069 return omit_one_operand (type, integer_zero_node, arg0);
8071 /* A < X && A + 1 > Y ==> A < X && A >= Y. Normally A + 1 > Y
8072 means A >= Y && A != MAX, but in this case we know that
8075 if (!TREE_SIDE_EFFECTS (arg0)
8076 && !TREE_SIDE_EFFECTS (arg1))
8078 tem = fold_to_nonsharp_ineq_using_bound (arg0, arg1);
8080 return fold (build2 (code, type, tem, arg1));
8082 tem = fold_to_nonsharp_ineq_using_bound (arg1, arg0);
8084 return fold (build2 (code, type, arg0, tem));
8088 /* We only do these simplifications if we are optimizing. */
8092 /* Check for things like (A || B) && (A || C). We can convert this
8093 to A || (B && C). Note that either operator can be any of the four
8094 truth and/or operations and the transformation will still be
8095 valid. Also note that we only care about order for the
8096 ANDIF and ORIF operators. If B contains side effects, this
8097 might change the truth-value of A. */
8098 if (TREE_CODE (arg0) == TREE_CODE (arg1)
8099 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
8100 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
8101 || TREE_CODE (arg0) == TRUTH_AND_EXPR
8102 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
8103 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
8105 tree a00 = TREE_OPERAND (arg0, 0);
8106 tree a01 = TREE_OPERAND (arg0, 1);
8107 tree a10 = TREE_OPERAND (arg1, 0);
8108 tree a11 = TREE_OPERAND (arg1, 1);
8109 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
8110 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
8111 && (code == TRUTH_AND_EXPR
8112 || code == TRUTH_OR_EXPR));
8114 if (operand_equal_p (a00, a10, 0))
8115 return fold (build2 (TREE_CODE (arg0), type, a00,
8116 fold (build2 (code, type, a01, a11))));
8117 else if (commutative && operand_equal_p (a00, a11, 0))
8118 return fold (build2 (TREE_CODE (arg0), type, a00,
8119 fold (build2 (code, type, a01, a10))));
8120 else if (commutative && operand_equal_p (a01, a10, 0))
8121 return fold (build2 (TREE_CODE (arg0), type, a01,
8122 fold (build2 (code, type, a00, a11))));
8124 /* This case if tricky because we must either have commutative
8125 operators or else A10 must not have side-effects. */
8127 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
8128 && operand_equal_p (a01, a11, 0))
8129 return fold (build2 (TREE_CODE (arg0), type,
8130 fold (build2 (code, type, a00, a10)),
8134 /* See if we can build a range comparison. */
8135 if (0 != (tem = fold_range_test (t)))
8138 /* Check for the possibility of merging component references. If our
8139 lhs is another similar operation, try to merge its rhs with our
8140 rhs. Then try to merge our lhs and rhs. */
8141 if (TREE_CODE (arg0) == code
8142 && 0 != (tem = fold_truthop (code, type,
8143 TREE_OPERAND (arg0, 1), arg1)))
8144 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), tem));
8146 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
8151 case TRUTH_ORIF_EXPR:
8152 /* Note that the operands of this must be ints
8153 and their values must be 0 or true.
8154 ("true" is a fixed value perhaps depending on the language.) */
8155 /* If first arg is constant true, return it. */
8156 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
8157 return fold_convert (type, arg0);
8159 /* If either arg is constant zero, drop it. */
8160 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
8161 return non_lvalue (fold_convert (type, arg1));
8162 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
8163 /* Preserve sequence points. */
8164 && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
8165 return non_lvalue (fold_convert (type, arg0));
8166 /* If second arg is constant true, result is true, but we must
8167 evaluate first arg. */
8168 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
8169 return omit_one_operand (type, arg1, arg0);
8170 /* Likewise for first arg, but note this only occurs here for
8172 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
8173 return omit_one_operand (type, arg0, arg1);
8175 /* !X || X is always true. */
8176 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
8177 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
8178 return omit_one_operand (type, integer_one_node, arg1);
8179 /* X || !X is always true. */
8180 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
8181 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
8182 return omit_one_operand (type, integer_one_node, arg0);
8186 case TRUTH_XOR_EXPR:
8187 /* If the second arg is constant zero, drop it. */
8188 if (integer_zerop (arg1))
8189 return non_lvalue (fold_convert (type, arg0));
8190 /* If the second arg is constant true, this is a logical inversion. */
8191 if (integer_onep (arg1))
8192 return non_lvalue (fold_convert (type, invert_truthvalue (arg0)));
8193 /* Identical arguments cancel to zero. */
8194 if (operand_equal_p (arg0, arg1, 0))
8195 return omit_one_operand (type, integer_zero_node, arg0);
8197 /* !X ^ X is always true. */
8198 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
8199 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
8200 return omit_one_operand (type, integer_one_node, arg1);
8202 /* X ^ !X is always true. */
8203 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
8204 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
8205 return omit_one_operand (type, integer_one_node, arg0);
8215 /* If one arg is a real or integer constant, put it last. */
8216 if (tree_swap_operands_p (arg0, arg1, true))
8217 return fold (build2 (swap_tree_comparison (code), type, arg1, arg0));
8219 /* If this is an equality comparison of the address of a non-weak
8220 object against zero, then we know the result. */
8221 if ((code == EQ_EXPR || code == NE_EXPR)
8222 && TREE_CODE (arg0) == ADDR_EXPR
8223 && DECL_P (TREE_OPERAND (arg0, 0))
8224 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
8225 && integer_zerop (arg1))
8226 return constant_boolean_node (code != EQ_EXPR, type);
8228 /* If this is an equality comparison of the address of two non-weak,
8229 unaliased symbols neither of which are extern (since we do not
8230 have access to attributes for externs), then we know the result. */
8231 if ((code == EQ_EXPR || code == NE_EXPR)
8232 && TREE_CODE (arg0) == ADDR_EXPR
8233 && DECL_P (TREE_OPERAND (arg0, 0))
8234 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
8235 && ! lookup_attribute ("alias",
8236 DECL_ATTRIBUTES (TREE_OPERAND (arg0, 0)))
8237 && ! DECL_EXTERNAL (TREE_OPERAND (arg0, 0))
8238 && TREE_CODE (arg1) == ADDR_EXPR
8239 && DECL_P (TREE_OPERAND (arg1, 0))
8240 && ! DECL_WEAK (TREE_OPERAND (arg1, 0))
8241 && ! lookup_attribute ("alias",
8242 DECL_ATTRIBUTES (TREE_OPERAND (arg1, 0)))
8243 && ! DECL_EXTERNAL (TREE_OPERAND (arg1, 0)))
8244 return constant_boolean_node (operand_equal_p (arg0, arg1, 0)
8245 ? code == EQ_EXPR : code != EQ_EXPR,
8248 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
8250 tree targ0 = strip_float_extensions (arg0);
8251 tree targ1 = strip_float_extensions (arg1);
8252 tree newtype = TREE_TYPE (targ0);
8254 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
8255 newtype = TREE_TYPE (targ1);
8257 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
8258 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
8259 return fold (build2 (code, type, fold_convert (newtype, targ0),
8260 fold_convert (newtype, targ1)));
8262 /* (-a) CMP (-b) -> b CMP a */
8263 if (TREE_CODE (arg0) == NEGATE_EXPR
8264 && TREE_CODE (arg1) == NEGATE_EXPR)
8265 return fold (build2 (code, type, TREE_OPERAND (arg1, 0),
8266 TREE_OPERAND (arg0, 0)));
8268 if (TREE_CODE (arg1) == REAL_CST)
8270 REAL_VALUE_TYPE cst;
8271 cst = TREE_REAL_CST (arg1);
8273 /* (-a) CMP CST -> a swap(CMP) (-CST) */
8274 if (TREE_CODE (arg0) == NEGATE_EXPR)
8276 fold (build2 (swap_tree_comparison (code), type,
8277 TREE_OPERAND (arg0, 0),
8278 build_real (TREE_TYPE (arg1),
8279 REAL_VALUE_NEGATE (cst))));
8281 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
8282 /* a CMP (-0) -> a CMP 0 */
8283 if (REAL_VALUE_MINUS_ZERO (cst))
8284 return fold (build2 (code, type, arg0,
8285 build_real (TREE_TYPE (arg1), dconst0)));
8287 /* x != NaN is always true, other ops are always false. */
8288 if (REAL_VALUE_ISNAN (cst)
8289 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))))
8291 tem = (code == NE_EXPR) ? integer_one_node : integer_zero_node;
8292 return omit_one_operand (type, tem, arg0);
8295 /* Fold comparisons against infinity. */
8296 if (REAL_VALUE_ISINF (cst))
8298 tem = fold_inf_compare (code, type, arg0, arg1);
8299 if (tem != NULL_TREE)
8304 /* If this is a comparison of a real constant with a PLUS_EXPR
8305 or a MINUS_EXPR of a real constant, we can convert it into a
8306 comparison with a revised real constant as long as no overflow
8307 occurs when unsafe_math_optimizations are enabled. */
8308 if (flag_unsafe_math_optimizations
8309 && TREE_CODE (arg1) == REAL_CST
8310 && (TREE_CODE (arg0) == PLUS_EXPR
8311 || TREE_CODE (arg0) == MINUS_EXPR)
8312 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
8313 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
8314 ? MINUS_EXPR : PLUS_EXPR,
8315 arg1, TREE_OPERAND (arg0, 1), 0))
8316 && ! TREE_CONSTANT_OVERFLOW (tem))
8317 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), tem));
8319 /* Likewise, we can simplify a comparison of a real constant with
8320 a MINUS_EXPR whose first operand is also a real constant, i.e.
8321 (c1 - x) < c2 becomes x > c1-c2. */
8322 if (flag_unsafe_math_optimizations
8323 && TREE_CODE (arg1) == REAL_CST
8324 && TREE_CODE (arg0) == MINUS_EXPR
8325 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST
8326 && 0 != (tem = const_binop (MINUS_EXPR, TREE_OPERAND (arg0, 0),
8328 && ! TREE_CONSTANT_OVERFLOW (tem))
8329 return fold (build2 (swap_tree_comparison (code), type,
8330 TREE_OPERAND (arg0, 1), tem));
8332 /* Fold comparisons against built-in math functions. */
8333 if (TREE_CODE (arg1) == REAL_CST
8334 && flag_unsafe_math_optimizations
8335 && ! flag_errno_math)
8337 enum built_in_function fcode = builtin_mathfn_code (arg0);
8339 if (fcode != END_BUILTINS)
8341 tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
8342 if (tem != NULL_TREE)
8348 /* Convert foo++ == CONST into ++foo == CONST + INCR. */
8349 if (TREE_CONSTANT (arg1)
8350 && (TREE_CODE (arg0) == POSTINCREMENT_EXPR
8351 || TREE_CODE (arg0) == POSTDECREMENT_EXPR)
8352 /* This optimization is invalid for ordered comparisons
8353 if CONST+INCR overflows or if foo+incr might overflow.
8354 This optimization is invalid for floating point due to rounding.
8355 For pointer types we assume overflow doesn't happen. */
8356 && (POINTER_TYPE_P (TREE_TYPE (arg0))
8357 || (INTEGRAL_TYPE_P (TREE_TYPE (arg0))
8358 && (code == EQ_EXPR || code == NE_EXPR))))
8360 tree varop, newconst;
8362 if (TREE_CODE (arg0) == POSTINCREMENT_EXPR)
8364 newconst = fold (build2 (PLUS_EXPR, TREE_TYPE (arg0),
8365 arg1, TREE_OPERAND (arg0, 1)));
8366 varop = build2 (PREINCREMENT_EXPR, TREE_TYPE (arg0),
8367 TREE_OPERAND (arg0, 0),
8368 TREE_OPERAND (arg0, 1));
8372 newconst = fold (build2 (MINUS_EXPR, TREE_TYPE (arg0),
8373 arg1, TREE_OPERAND (arg0, 1)));
8374 varop = build2 (PREDECREMENT_EXPR, TREE_TYPE (arg0),
8375 TREE_OPERAND (arg0, 0),
8376 TREE_OPERAND (arg0, 1));
8380 /* If VAROP is a reference to a bitfield, we must mask
8381 the constant by the width of the field. */
8382 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
8383 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (varop, 0), 1))
8384 && host_integerp (DECL_SIZE (TREE_OPERAND
8385 (TREE_OPERAND (varop, 0), 1)), 1))
8387 tree fielddecl = TREE_OPERAND (TREE_OPERAND (varop, 0), 1);
8388 HOST_WIDE_INT size = tree_low_cst (DECL_SIZE (fielddecl), 1);
8389 tree folded_compare, shift;
8391 /* First check whether the comparison would come out
8392 always the same. If we don't do that we would
8393 change the meaning with the masking. */
8394 folded_compare = fold (build2 (code, type,
8395 TREE_OPERAND (varop, 0), arg1));
8396 if (integer_zerop (folded_compare)
8397 || integer_onep (folded_compare))
8398 return omit_one_operand (type, folded_compare, varop);
8400 shift = build_int_cst (NULL_TREE,
8401 TYPE_PRECISION (TREE_TYPE (varop)) - size);
8402 shift = fold_convert (TREE_TYPE (varop), shift);
8403 newconst = fold (build2 (LSHIFT_EXPR, TREE_TYPE (varop),
8405 newconst = fold (build2 (RSHIFT_EXPR, TREE_TYPE (varop),
8409 return fold (build2 (code, type, varop, newconst));
8412 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
8413 This transformation affects the cases which are handled in later
8414 optimizations involving comparisons with non-negative constants. */
8415 if (TREE_CODE (arg1) == INTEGER_CST
8416 && TREE_CODE (arg0) != INTEGER_CST
8417 && tree_int_cst_sgn (arg1) > 0)
8422 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
8423 return fold (build2 (GT_EXPR, type, arg0, arg1));
8426 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
8427 return fold (build2 (LE_EXPR, type, arg0, arg1));
8434 /* Comparisons with the highest or lowest possible integer of
8435 the specified size will have known values.
8437 This is quite similar to fold_relational_hi_lo, however,
8438 attempts to share the code have been nothing but trouble. */
8440 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1)));
8442 if (TREE_CODE (arg1) == INTEGER_CST
8443 && ! TREE_CONSTANT_OVERFLOW (arg1)
8444 && width <= 2 * HOST_BITS_PER_WIDE_INT
8445 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
8446 || POINTER_TYPE_P (TREE_TYPE (arg1))))
8448 HOST_WIDE_INT signed_max_hi;
8449 unsigned HOST_WIDE_INT signed_max_lo;
8450 unsigned HOST_WIDE_INT max_hi, max_lo, min_hi, min_lo;
8452 if (width <= HOST_BITS_PER_WIDE_INT)
8454 signed_max_lo = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
8459 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
8461 max_lo = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
8467 max_lo = signed_max_lo;
8468 min_lo = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
8474 width -= HOST_BITS_PER_WIDE_INT;
8476 signed_max_hi = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
8481 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
8483 max_hi = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
8488 max_hi = signed_max_hi;
8489 min_hi = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
8493 if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1) == max_hi
8494 && TREE_INT_CST_LOW (arg1) == max_lo)
8498 return omit_one_operand (type, integer_zero_node, arg0);
8501 return fold (build2 (EQ_EXPR, type, arg0, arg1));
8504 return omit_one_operand (type, integer_one_node, arg0);
8507 return fold (build2 (NE_EXPR, type, arg0, arg1));
8509 /* The GE_EXPR and LT_EXPR cases above are not normally
8510 reached because of previous transformations. */
8515 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
8517 && TREE_INT_CST_LOW (arg1) == max_lo - 1)
8521 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
8522 return fold (build2 (EQ_EXPR, type, arg0, arg1));
8524 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
8525 return fold (build2 (NE_EXPR, type, arg0, arg1));
8529 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
8531 && TREE_INT_CST_LOW (arg1) == min_lo)
8535 return omit_one_operand (type, integer_zero_node, arg0);
8538 return fold (build2 (EQ_EXPR, type, arg0, arg1));
8541 return omit_one_operand (type, integer_one_node, arg0);
8544 return fold (build2 (NE_EXPR, type, arg0, arg1));
8549 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
8551 && TREE_INT_CST_LOW (arg1) == min_lo + 1)
8555 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
8556 return fold (build2 (NE_EXPR, type, arg0, arg1));
8558 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
8559 return fold (build2 (EQ_EXPR, type, arg0, arg1));
8564 else if (!in_gimple_form
8565 && TREE_INT_CST_HIGH (arg1) == signed_max_hi
8566 && TREE_INT_CST_LOW (arg1) == signed_max_lo
8567 && TYPE_UNSIGNED (TREE_TYPE (arg1))
8568 /* signed_type does not work on pointer types. */
8569 && INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
8571 /* The following case also applies to X < signed_max+1
8572 and X >= signed_max+1 because previous transformations. */
8573 if (code == LE_EXPR || code == GT_EXPR)
8576 st0 = lang_hooks.types.signed_type (TREE_TYPE (arg0));
8577 st1 = lang_hooks.types.signed_type (TREE_TYPE (arg1));
8579 (build2 (code == LE_EXPR ? GE_EXPR: LT_EXPR,
8580 type, fold_convert (st0, arg0),
8581 fold_convert (st1, integer_zero_node)));
8587 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
8588 a MINUS_EXPR of a constant, we can convert it into a comparison with
8589 a revised constant as long as no overflow occurs. */
8590 if ((code == EQ_EXPR || code == NE_EXPR)
8591 && TREE_CODE (arg1) == INTEGER_CST
8592 && (TREE_CODE (arg0) == PLUS_EXPR
8593 || TREE_CODE (arg0) == MINUS_EXPR)
8594 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8595 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
8596 ? MINUS_EXPR : PLUS_EXPR,
8597 arg1, TREE_OPERAND (arg0, 1), 0))
8598 && ! TREE_CONSTANT_OVERFLOW (tem))
8599 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), tem));
8601 /* Similarly for a NEGATE_EXPR. */
8602 else if ((code == EQ_EXPR || code == NE_EXPR)
8603 && TREE_CODE (arg0) == NEGATE_EXPR
8604 && TREE_CODE (arg1) == INTEGER_CST
8605 && 0 != (tem = negate_expr (arg1))
8606 && TREE_CODE (tem) == INTEGER_CST
8607 && ! TREE_CONSTANT_OVERFLOW (tem))
8608 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), tem));
8610 /* If we have X - Y == 0, we can convert that to X == Y and similarly
8611 for !=. Don't do this for ordered comparisons due to overflow. */
8612 else if ((code == NE_EXPR || code == EQ_EXPR)
8613 && integer_zerop (arg1) && TREE_CODE (arg0) == MINUS_EXPR)
8614 return fold (build2 (code, type,
8615 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1)));
8617 else if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
8618 && TREE_CODE (arg0) == NOP_EXPR)
8620 /* If we are widening one operand of an integer comparison,
8621 see if the other operand is similarly being widened. Perhaps we
8622 can do the comparison in the narrower type. */
8623 tem = fold_widened_comparison (code, type, arg0, arg1);
8627 /* Or if we are changing signedness. */
8628 tem = fold_sign_changed_comparison (code, type, arg0, arg1);
8633 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
8634 constant, we can simplify it. */
8635 else if (TREE_CODE (arg1) == INTEGER_CST
8636 && (TREE_CODE (arg0) == MIN_EXPR
8637 || TREE_CODE (arg0) == MAX_EXPR)
8638 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8639 return optimize_minmax_comparison (t);
8641 /* If we are comparing an ABS_EXPR with a constant, we can
8642 convert all the cases into explicit comparisons, but they may
8643 well not be faster than doing the ABS and one comparison.
8644 But ABS (X) <= C is a range comparison, which becomes a subtraction
8645 and a comparison, and is probably faster. */
8646 else if (code == LE_EXPR && TREE_CODE (arg1) == INTEGER_CST
8647 && TREE_CODE (arg0) == ABS_EXPR
8648 && ! TREE_SIDE_EFFECTS (arg0)
8649 && (0 != (tem = negate_expr (arg1)))
8650 && TREE_CODE (tem) == INTEGER_CST
8651 && ! TREE_CONSTANT_OVERFLOW (tem))
8652 return fold (build2 (TRUTH_ANDIF_EXPR, type,
8653 build2 (GE_EXPR, type,
8654 TREE_OPERAND (arg0, 0), tem),
8655 build2 (LE_EXPR, type,
8656 TREE_OPERAND (arg0, 0), arg1)));
8658 /* If this is an EQ or NE comparison with zero and ARG0 is
8659 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
8660 two operations, but the latter can be done in one less insn
8661 on machines that have only two-operand insns or on which a
8662 constant cannot be the first operand. */
8663 if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR)
8664 && TREE_CODE (arg0) == BIT_AND_EXPR)
8666 tree arg00 = TREE_OPERAND (arg0, 0);
8667 tree arg01 = TREE_OPERAND (arg0, 1);
8668 if (TREE_CODE (arg00) == LSHIFT_EXPR
8669 && integer_onep (TREE_OPERAND (arg00, 0)))
8671 fold (build2 (code, type,
8672 build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
8673 build2 (RSHIFT_EXPR, TREE_TYPE (arg00),
8674 arg01, TREE_OPERAND (arg00, 1)),
8675 fold_convert (TREE_TYPE (arg0),
8678 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
8679 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
8681 fold (build2 (code, type,
8682 build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
8683 build2 (RSHIFT_EXPR, TREE_TYPE (arg01),
8684 arg00, TREE_OPERAND (arg01, 1)),
8685 fold_convert (TREE_TYPE (arg0),
8690 /* If this is an NE or EQ comparison of zero against the result of a
8691 signed MOD operation whose second operand is a power of 2, make
8692 the MOD operation unsigned since it is simpler and equivalent. */
8693 if ((code == NE_EXPR || code == EQ_EXPR)
8694 && integer_zerop (arg1)
8695 && !TYPE_UNSIGNED (TREE_TYPE (arg0))
8696 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
8697 || TREE_CODE (arg0) == CEIL_MOD_EXPR
8698 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
8699 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
8700 && integer_pow2p (TREE_OPERAND (arg0, 1)))
8702 tree newtype = lang_hooks.types.unsigned_type (TREE_TYPE (arg0));
8703 tree newmod = fold (build2 (TREE_CODE (arg0), newtype,
8704 fold_convert (newtype,
8705 TREE_OPERAND (arg0, 0)),
8706 fold_convert (newtype,
8707 TREE_OPERAND (arg0, 1))));
8709 return fold (build2 (code, type, newmod,
8710 fold_convert (newtype, arg1)));
8713 /* If this is an NE comparison of zero with an AND of one, remove the
8714 comparison since the AND will give the correct value. */
8715 if (code == NE_EXPR && integer_zerop (arg1)
8716 && TREE_CODE (arg0) == BIT_AND_EXPR
8717 && integer_onep (TREE_OPERAND (arg0, 1)))
8718 return fold_convert (type, arg0);
8720 /* If we have (A & C) == C where C is a power of 2, convert this into
8721 (A & C) != 0. Similarly for NE_EXPR. */
8722 if ((code == EQ_EXPR || code == NE_EXPR)
8723 && TREE_CODE (arg0) == BIT_AND_EXPR
8724 && integer_pow2p (TREE_OPERAND (arg0, 1))
8725 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
8726 return fold (build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
8727 arg0, fold_convert (TREE_TYPE (arg0),
8728 integer_zero_node)));
8730 /* If we have (A & C) != 0 or (A & C) == 0 and C is a power of
8731 2, then fold the expression into shifts and logical operations. */
8732 tem = fold_single_bit_test (code, arg0, arg1, type);
8736 /* If we have (A & C) == D where D & ~C != 0, convert this into 0.
8737 Similarly for NE_EXPR. */
8738 if ((code == EQ_EXPR || code == NE_EXPR)
8739 && TREE_CODE (arg0) == BIT_AND_EXPR
8740 && TREE_CODE (arg1) == INTEGER_CST
8741 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8743 tree notc = fold (build1 (BIT_NOT_EXPR,
8744 TREE_TYPE (TREE_OPERAND (arg0, 1)),
8745 TREE_OPERAND (arg0, 1)));
8746 tree dandnotc = fold (build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
8748 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
8749 if (integer_nonzerop (dandnotc))
8750 return omit_one_operand (type, rslt, arg0);
8753 /* If we have (A | C) == D where C & ~D != 0, convert this into 0.
8754 Similarly for NE_EXPR. */
8755 if ((code == EQ_EXPR || code == NE_EXPR)
8756 && TREE_CODE (arg0) == BIT_IOR_EXPR
8757 && TREE_CODE (arg1) == INTEGER_CST
8758 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8760 tree notd = fold (build1 (BIT_NOT_EXPR, TREE_TYPE (arg1), arg1));
8761 tree candnotd = fold (build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
8762 TREE_OPERAND (arg0, 1), notd));
8763 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
8764 if (integer_nonzerop (candnotd))
8765 return omit_one_operand (type, rslt, arg0);
8768 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
8769 and similarly for >= into !=. */
8770 if ((code == LT_EXPR || code == GE_EXPR)
8771 && TYPE_UNSIGNED (TREE_TYPE (arg0))
8772 && TREE_CODE (arg1) == LSHIFT_EXPR
8773 && integer_onep (TREE_OPERAND (arg1, 0)))
8774 return build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
8775 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
8776 TREE_OPERAND (arg1, 1)),
8777 fold_convert (TREE_TYPE (arg0), integer_zero_node));
8779 else if ((code == LT_EXPR || code == GE_EXPR)
8780 && TYPE_UNSIGNED (TREE_TYPE (arg0))
8781 && (TREE_CODE (arg1) == NOP_EXPR
8782 || TREE_CODE (arg1) == CONVERT_EXPR)
8783 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
8784 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
8786 build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
8787 fold_convert (TREE_TYPE (arg0),
8788 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
8789 TREE_OPERAND (TREE_OPERAND (arg1, 0),
8791 fold_convert (TREE_TYPE (arg0), integer_zero_node));
8793 /* Simplify comparison of something with itself. (For IEEE
8794 floating-point, we can only do some of these simplifications.) */
8795 if (operand_equal_p (arg0, arg1, 0))
8800 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
8801 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8802 return constant_boolean_node (1, type);
8807 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
8808 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8809 return constant_boolean_node (1, type);
8810 return fold (build2 (EQ_EXPR, type, arg0, arg1));
8813 /* For NE, we can only do this simplification if integer
8814 or we don't honor IEEE floating point NaNs. */
8815 if (FLOAT_TYPE_P (TREE_TYPE (arg0))
8816 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8818 /* ... fall through ... */
8821 return constant_boolean_node (0, type);
8827 /* If we are comparing an expression that just has comparisons
8828 of two integer values, arithmetic expressions of those comparisons,
8829 and constants, we can simplify it. There are only three cases
8830 to check: the two values can either be equal, the first can be
8831 greater, or the second can be greater. Fold the expression for
8832 those three values. Since each value must be 0 or 1, we have
8833 eight possibilities, each of which corresponds to the constant 0
8834 or 1 or one of the six possible comparisons.
8836 This handles common cases like (a > b) == 0 but also handles
8837 expressions like ((x > y) - (y > x)) > 0, which supposedly
8838 occur in macroized code. */
8840 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
8842 tree cval1 = 0, cval2 = 0;
8845 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
8846 /* Don't handle degenerate cases here; they should already
8847 have been handled anyway. */
8848 && cval1 != 0 && cval2 != 0
8849 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
8850 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
8851 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
8852 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
8853 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
8854 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
8855 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
8857 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
8858 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
8860 /* We can't just pass T to eval_subst in case cval1 or cval2
8861 was the same as ARG1. */
8864 = fold (build2 (code, type,
8865 eval_subst (arg0, cval1, maxval,
8869 = fold (build2 (code, type,
8870 eval_subst (arg0, cval1, maxval,
8874 = fold (build2 (code, type,
8875 eval_subst (arg0, cval1, minval,
8879 /* All three of these results should be 0 or 1. Confirm they
8880 are. Then use those values to select the proper code
8883 if ((integer_zerop (high_result)
8884 || integer_onep (high_result))
8885 && (integer_zerop (equal_result)
8886 || integer_onep (equal_result))
8887 && (integer_zerop (low_result)
8888 || integer_onep (low_result)))
8890 /* Make a 3-bit mask with the high-order bit being the
8891 value for `>', the next for '=', and the low for '<'. */
8892 switch ((integer_onep (high_result) * 4)
8893 + (integer_onep (equal_result) * 2)
8894 + integer_onep (low_result))
8898 return omit_one_operand (type, integer_zero_node, arg0);
8919 return omit_one_operand (type, integer_one_node, arg0);
8922 tem = build2 (code, type, cval1, cval2);
8924 return save_expr (tem);
8931 /* If this is a comparison of a field, we may be able to simplify it. */
8932 if (((TREE_CODE (arg0) == COMPONENT_REF
8933 && lang_hooks.can_use_bit_fields_p ())
8934 || TREE_CODE (arg0) == BIT_FIELD_REF)
8935 && (code == EQ_EXPR || code == NE_EXPR)
8936 /* Handle the constant case even without -O
8937 to make sure the warnings are given. */
8938 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
8940 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
8945 /* If this is a comparison of complex values and either or both sides
8946 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
8947 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
8948 This may prevent needless evaluations. */
8949 if ((code == EQ_EXPR || code == NE_EXPR)
8950 && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
8951 && (TREE_CODE (arg0) == COMPLEX_EXPR
8952 || TREE_CODE (arg1) == COMPLEX_EXPR
8953 || TREE_CODE (arg0) == COMPLEX_CST
8954 || TREE_CODE (arg1) == COMPLEX_CST))
8956 tree subtype = TREE_TYPE (TREE_TYPE (arg0));
8957 tree real0, imag0, real1, imag1;
8959 arg0 = save_expr (arg0);
8960 arg1 = save_expr (arg1);
8961 real0 = fold (build1 (REALPART_EXPR, subtype, arg0));
8962 imag0 = fold (build1 (IMAGPART_EXPR, subtype, arg0));
8963 real1 = fold (build1 (REALPART_EXPR, subtype, arg1));
8964 imag1 = fold (build1 (IMAGPART_EXPR, subtype, arg1));
8966 return fold (build2 ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR
8969 fold (build2 (code, type, real0, real1)),
8970 fold (build2 (code, type, imag0, imag1))));
8973 /* Optimize comparisons of strlen vs zero to a compare of the
8974 first character of the string vs zero. To wit,
8975 strlen(ptr) == 0 => *ptr == 0
8976 strlen(ptr) != 0 => *ptr != 0
8977 Other cases should reduce to one of these two (or a constant)
8978 due to the return value of strlen being unsigned. */
8979 if ((code == EQ_EXPR || code == NE_EXPR)
8980 && integer_zerop (arg1)
8981 && TREE_CODE (arg0) == CALL_EXPR)
8983 tree fndecl = get_callee_fndecl (arg0);
8987 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
8988 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
8989 && (arglist = TREE_OPERAND (arg0, 1))
8990 && TREE_CODE (TREE_TYPE (TREE_VALUE (arglist))) == POINTER_TYPE
8991 && ! TREE_CHAIN (arglist))
8992 return fold (build2 (code, type,
8993 build1 (INDIRECT_REF, char_type_node,
8994 TREE_VALUE (arglist)),
8995 fold_convert (char_type_node,
8996 integer_zero_node)));
8999 /* We can fold X/C1 op C2 where C1 and C2 are integer constants
9000 into a single range test. */
9001 if ((TREE_CODE (arg0) == TRUNC_DIV_EXPR
9002 || TREE_CODE (arg0) == EXACT_DIV_EXPR)
9003 && TREE_CODE (arg1) == INTEGER_CST
9004 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
9005 && !integer_zerop (TREE_OPERAND (arg0, 1))
9006 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
9007 && !TREE_OVERFLOW (arg1))
9009 t1 = fold_div_compare (code, type, arg0, arg1);
9010 if (t1 != NULL_TREE)
9014 if ((code == EQ_EXPR || code == NE_EXPR)
9015 && !TREE_SIDE_EFFECTS (arg0)
9016 && integer_zerop (arg1)
9017 && tree_expr_nonzero_p (arg0))
9018 return constant_boolean_node (code==NE_EXPR, type);
9020 t1 = fold_relational_const (code, type, arg0, arg1);
9021 return t1 == NULL_TREE ? t : t1;
9023 case UNORDERED_EXPR:
9031 if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
9033 t1 = fold_relational_const (code, type, arg0, arg1);
9034 if (t1 != NULL_TREE)
9038 /* If the first operand is NaN, the result is constant. */
9039 if (TREE_CODE (arg0) == REAL_CST
9040 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
9041 && (code != LTGT_EXPR || ! flag_trapping_math))
9043 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
9046 return omit_one_operand (type, t1, arg1);
9049 /* If the second operand is NaN, the result is constant. */
9050 if (TREE_CODE (arg1) == REAL_CST
9051 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg1))
9052 && (code != LTGT_EXPR || ! flag_trapping_math))
9054 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
9057 return omit_one_operand (type, t1, arg0);
9060 /* Simplify unordered comparison of something with itself. */
9061 if ((code == UNLE_EXPR || code == UNGE_EXPR || code == UNEQ_EXPR)
9062 && operand_equal_p (arg0, arg1, 0))
9063 return constant_boolean_node (1, type);
9065 if (code == LTGT_EXPR
9066 && !flag_trapping_math
9067 && operand_equal_p (arg0, arg1, 0))
9068 return constant_boolean_node (0, type);
9070 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
9072 tree targ0 = strip_float_extensions (arg0);
9073 tree targ1 = strip_float_extensions (arg1);
9074 tree newtype = TREE_TYPE (targ0);
9076 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
9077 newtype = TREE_TYPE (targ1);
9079 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
9080 return fold (build2 (code, type, fold_convert (newtype, targ0),
9081 fold_convert (newtype, targ1)));
9087 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
9088 so all simple results must be passed through pedantic_non_lvalue. */
9089 if (TREE_CODE (arg0) == INTEGER_CST)
9091 tem = TREE_OPERAND (t, (integer_zerop (arg0) ? 2 : 1));
9092 /* Only optimize constant conditions when the selected branch
9093 has the same type as the COND_EXPR. This avoids optimizing
9094 away "c ? x : throw", where the throw has a void type. */
9095 if (! VOID_TYPE_P (TREE_TYPE (tem))
9096 || VOID_TYPE_P (type))
9097 return pedantic_non_lvalue (tem);
9100 if (operand_equal_p (arg1, TREE_OPERAND (t, 2), 0))
9101 return pedantic_omit_one_operand (type, arg1, arg0);
9103 /* If we have A op B ? A : C, we may be able to convert this to a
9104 simpler expression, depending on the operation and the values
9105 of B and C. Signed zeros prevent all of these transformations,
9106 for reasons given above each one.
9108 Also try swapping the arguments and inverting the conditional. */
9109 if (COMPARISON_CLASS_P (arg0)
9110 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
9111 arg1, TREE_OPERAND (arg0, 1))
9112 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
9114 tem = fold_cond_expr_with_comparison (type, arg0,
9115 TREE_OPERAND (t, 1),
9116 TREE_OPERAND (t, 2));
9121 if (COMPARISON_CLASS_P (arg0)
9122 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
9123 TREE_OPERAND (t, 2),
9124 TREE_OPERAND (arg0, 1))
9125 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (TREE_OPERAND (t, 2)))))
9127 tem = invert_truthvalue (arg0);
9128 if (COMPARISON_CLASS_P (tem))
9130 tem = fold_cond_expr_with_comparison (type, tem,
9131 TREE_OPERAND (t, 2),
9132 TREE_OPERAND (t, 1));
9138 /* If the second operand is simpler than the third, swap them
9139 since that produces better jump optimization results. */
9140 if (tree_swap_operands_p (TREE_OPERAND (t, 1),
9141 TREE_OPERAND (t, 2), false))
9143 /* See if this can be inverted. If it can't, possibly because
9144 it was a floating-point inequality comparison, don't do
9146 tem = invert_truthvalue (arg0);
9148 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
9149 return fold (build3 (code, type, tem,
9150 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1)));
9153 /* Convert A ? 1 : 0 to simply A. */
9154 if (integer_onep (TREE_OPERAND (t, 1))
9155 && integer_zerop (TREE_OPERAND (t, 2))
9156 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
9157 call to fold will try to move the conversion inside
9158 a COND, which will recurse. In that case, the COND_EXPR
9159 is probably the best choice, so leave it alone. */
9160 && type == TREE_TYPE (arg0))
9161 return pedantic_non_lvalue (arg0);
9163 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
9164 over COND_EXPR in cases such as floating point comparisons. */
9165 if (integer_zerop (TREE_OPERAND (t, 1))
9166 && integer_onep (TREE_OPERAND (t, 2))
9167 && truth_value_p (TREE_CODE (arg0)))
9168 return pedantic_non_lvalue (fold_convert (type,
9169 invert_truthvalue (arg0)));
9171 /* A < 0 ? <sign bit of A> : 0 is simply (A & <sign bit of A>). */
9172 if (TREE_CODE (arg0) == LT_EXPR
9173 && integer_zerop (TREE_OPERAND (arg0, 1))
9174 && integer_zerop (TREE_OPERAND (t, 2))
9175 && (tem = sign_bit_p (TREE_OPERAND (arg0, 0), arg1)))
9176 return fold_convert (type, fold (build2 (BIT_AND_EXPR,
9177 TREE_TYPE (tem), tem, arg1)));
9179 /* (A >> N) & 1 ? (1 << N) : 0 is simply A & (1 << N). A & 1 was
9180 already handled above. */
9181 if (TREE_CODE (arg0) == BIT_AND_EXPR
9182 && integer_onep (TREE_OPERAND (arg0, 1))
9183 && integer_zerop (TREE_OPERAND (t, 2))
9184 && integer_pow2p (arg1))
9186 tree tem = TREE_OPERAND (arg0, 0);
9188 if (TREE_CODE (tem) == RSHIFT_EXPR
9189 && TREE_CODE (TREE_OPERAND (tem, 1)) == INTEGER_CST
9190 && (unsigned HOST_WIDE_INT) tree_log2 (arg1) ==
9191 TREE_INT_CST_LOW (TREE_OPERAND (tem, 1)))
9192 return fold (build2 (BIT_AND_EXPR, type,
9193 TREE_OPERAND (tem, 0), arg1));
9196 /* A & N ? N : 0 is simply A & N if N is a power of two. This
9197 is probably obsolete because the first operand should be a
9198 truth value (that's why we have the two cases above), but let's
9199 leave it in until we can confirm this for all front-ends. */
9200 if (integer_zerop (TREE_OPERAND (t, 2))
9201 && TREE_CODE (arg0) == NE_EXPR
9202 && integer_zerop (TREE_OPERAND (arg0, 1))
9203 && integer_pow2p (arg1)
9204 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
9205 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
9206 arg1, OEP_ONLY_CONST))
9207 return pedantic_non_lvalue (fold_convert (type,
9208 TREE_OPERAND (arg0, 0)));
9210 /* Convert A ? B : 0 into A && B if A and B are truth values. */
9211 if (integer_zerop (TREE_OPERAND (t, 2))
9212 && truth_value_p (TREE_CODE (arg0))
9213 && truth_value_p (TREE_CODE (arg1)))
9214 return fold (build2 (TRUTH_ANDIF_EXPR, type, arg0, arg1));
9216 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
9217 if (integer_onep (TREE_OPERAND (t, 2))
9218 && truth_value_p (TREE_CODE (arg0))
9219 && truth_value_p (TREE_CODE (arg1)))
9221 /* Only perform transformation if ARG0 is easily inverted. */
9222 tem = invert_truthvalue (arg0);
9223 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
9224 return fold (build2 (TRUTH_ORIF_EXPR, type, tem, arg1));
9227 /* Convert A ? 0 : B into !A && B if A and B are truth values. */
9228 if (integer_zerop (arg1)
9229 && truth_value_p (TREE_CODE (arg0))
9230 && truth_value_p (TREE_CODE (TREE_OPERAND (t, 2))))
9232 /* Only perform transformation if ARG0 is easily inverted. */
9233 tem = invert_truthvalue (arg0);
9234 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
9235 return fold (build2 (TRUTH_ANDIF_EXPR, type, tem,
9236 TREE_OPERAND (t, 2)));
9239 /* Convert A ? 1 : B into A || B if A and B are truth values. */
9240 if (integer_onep (arg1)
9241 && truth_value_p (TREE_CODE (arg0))
9242 && truth_value_p (TREE_CODE (TREE_OPERAND (t, 2))))
9243 return fold (build2 (TRUTH_ORIF_EXPR, type, arg0,
9244 TREE_OPERAND (t, 2)));
9249 /* When pedantic, a compound expression can be neither an lvalue
9250 nor an integer constant expression. */
9251 if (TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
9253 /* Don't let (0, 0) be null pointer constant. */
9254 tem = integer_zerop (arg1) ? build1 (NOP_EXPR, type, arg1)
9255 : fold_convert (type, arg1);
9256 return pedantic_non_lvalue (tem);
9260 return build_complex (type, arg0, arg1);
9264 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
9266 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
9267 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
9268 TREE_OPERAND (arg0, 1));
9269 else if (TREE_CODE (arg0) == COMPLEX_CST)
9270 return TREE_REALPART (arg0);
9271 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
9272 return fold (build2 (TREE_CODE (arg0), type,
9273 fold (build1 (REALPART_EXPR, type,
9274 TREE_OPERAND (arg0, 0))),
9275 fold (build1 (REALPART_EXPR, type,
9276 TREE_OPERAND (arg0, 1)))));
9280 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
9281 return fold_convert (type, integer_zero_node);
9282 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
9283 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
9284 TREE_OPERAND (arg0, 0));
9285 else if (TREE_CODE (arg0) == COMPLEX_CST)
9286 return TREE_IMAGPART (arg0);
9287 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
9288 return fold (build2 (TREE_CODE (arg0), type,
9289 fold (build1 (IMAGPART_EXPR, type,
9290 TREE_OPERAND (arg0, 0))),
9291 fold (build1 (IMAGPART_EXPR, type,
9292 TREE_OPERAND (arg0, 1)))));
9296 /* Check for a built-in function. */
9297 if (TREE_CODE (TREE_OPERAND (t, 0)) == ADDR_EXPR
9298 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0))
9300 && DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (t, 0), 0)))
9302 tree tmp = fold_builtin (t, false);
9310 } /* switch (code) */
9313 #ifdef ENABLE_FOLD_CHECKING
9316 static void fold_checksum_tree (tree, struct md5_ctx *, htab_t);
9317 static void fold_check_failed (tree, tree);
9318 void print_fold_checksum (tree);
9320 /* When --enable-checking=fold, compute a digest of expr before
9321 and after actual fold call to see if fold did not accidentally
9322 change original expr. */
9329 unsigned char checksum_before[16], checksum_after[16];
9332 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
9333 md5_init_ctx (&ctx);
9334 fold_checksum_tree (expr, &ctx, ht);
9335 md5_finish_ctx (&ctx, checksum_before);
9338 ret = fold_1 (expr);
9340 md5_init_ctx (&ctx);
9341 fold_checksum_tree (expr, &ctx, ht);
9342 md5_finish_ctx (&ctx, checksum_after);
9345 if (memcmp (checksum_before, checksum_after, 16))
9346 fold_check_failed (expr, ret);
9352 print_fold_checksum (tree expr)
9355 unsigned char checksum[16], cnt;
9358 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
9359 md5_init_ctx (&ctx);
9360 fold_checksum_tree (expr, &ctx, ht);
9361 md5_finish_ctx (&ctx, checksum);
9363 for (cnt = 0; cnt < 16; ++cnt)
9364 fprintf (stderr, "%02x", checksum[cnt]);
9365 putc ('\n', stderr);
9369 fold_check_failed (tree expr ATTRIBUTE_UNUSED, tree ret ATTRIBUTE_UNUSED)
9371 internal_error ("fold check: original tree changed by fold");
9375 fold_checksum_tree (tree expr, struct md5_ctx *ctx, htab_t ht)
9378 enum tree_code code;
9379 char buf[sizeof (struct tree_decl)];
9382 gcc_assert ((sizeof (struct tree_exp) + 5 * sizeof (tree)
9383 <= sizeof (struct tree_decl))
9384 && sizeof (struct tree_type) <= sizeof (struct tree_decl));
9387 slot = htab_find_slot (ht, expr, INSERT);
9391 code = TREE_CODE (expr);
9392 if (TREE_CODE_CLASS (code) == tcc_declaration
9393 && DECL_ASSEMBLER_NAME_SET_P (expr))
9395 /* Allow DECL_ASSEMBLER_NAME to be modified. */
9396 memcpy (buf, expr, tree_size (expr));
9398 SET_DECL_ASSEMBLER_NAME (expr, NULL);
9400 else if (TREE_CODE_CLASS (code) == tcc_type
9401 && (TYPE_POINTER_TO (expr) || TYPE_REFERENCE_TO (expr)
9402 || TYPE_CACHED_VALUES_P (expr)))
9404 /* Allow these fields to be modified. */
9405 memcpy (buf, expr, tree_size (expr));
9407 TYPE_POINTER_TO (expr) = NULL;
9408 TYPE_REFERENCE_TO (expr) = NULL;
9409 TYPE_CACHED_VALUES_P (expr) = 0;
9410 TYPE_CACHED_VALUES (expr) = NULL;
9412 md5_process_bytes (expr, tree_size (expr), ctx);
9413 fold_checksum_tree (TREE_TYPE (expr), ctx, ht);
9414 if (TREE_CODE_CLASS (code) != tcc_type
9415 && TREE_CODE_CLASS (code) != tcc_declaration)
9416 fold_checksum_tree (TREE_CHAIN (expr), ctx, ht);
9417 switch (TREE_CODE_CLASS (code))
9423 md5_process_bytes (TREE_STRING_POINTER (expr),
9424 TREE_STRING_LENGTH (expr), ctx);
9427 fold_checksum_tree (TREE_REALPART (expr), ctx, ht);
9428 fold_checksum_tree (TREE_IMAGPART (expr), ctx, ht);
9431 fold_checksum_tree (TREE_VECTOR_CST_ELTS (expr), ctx, ht);
9437 case tcc_exceptional:
9441 fold_checksum_tree (TREE_PURPOSE (expr), ctx, ht);
9442 fold_checksum_tree (TREE_VALUE (expr), ctx, ht);
9445 for (i = 0; i < TREE_VEC_LENGTH (expr); ++i)
9446 fold_checksum_tree (TREE_VEC_ELT (expr, i), ctx, ht);
9452 case tcc_expression:
9454 case tcc_comparison:
9458 len = TREE_CODE_LENGTH (code);
9459 for (i = 0; i < len; ++i)
9460 fold_checksum_tree (TREE_OPERAND (expr, i), ctx, ht);
9462 case tcc_declaration:
9463 fold_checksum_tree (DECL_SIZE (expr), ctx, ht);
9464 fold_checksum_tree (DECL_SIZE_UNIT (expr), ctx, ht);
9465 fold_checksum_tree (DECL_NAME (expr), ctx, ht);
9466 fold_checksum_tree (DECL_CONTEXT (expr), ctx, ht);
9467 fold_checksum_tree (DECL_ARGUMENTS (expr), ctx, ht);
9468 fold_checksum_tree (DECL_RESULT_FLD (expr), ctx, ht);
9469 fold_checksum_tree (DECL_INITIAL (expr), ctx, ht);
9470 fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr), ctx, ht);
9471 fold_checksum_tree (DECL_SECTION_NAME (expr), ctx, ht);
9472 fold_checksum_tree (DECL_ATTRIBUTES (expr), ctx, ht);
9473 fold_checksum_tree (DECL_VINDEX (expr), ctx, ht);
9476 if (TREE_CODE (expr) == ENUMERAL_TYPE)
9477 fold_checksum_tree (TYPE_VALUES (expr), ctx, ht);
9478 fold_checksum_tree (TYPE_SIZE (expr), ctx, ht);
9479 fold_checksum_tree (TYPE_SIZE_UNIT (expr), ctx, ht);
9480 fold_checksum_tree (TYPE_ATTRIBUTES (expr), ctx, ht);
9481 fold_checksum_tree (TYPE_NAME (expr), ctx, ht);
9482 if (INTEGRAL_TYPE_P (expr)
9483 || SCALAR_FLOAT_TYPE_P (expr))
9485 fold_checksum_tree (TYPE_MIN_VALUE (expr), ctx, ht);
9486 fold_checksum_tree (TYPE_MAX_VALUE (expr), ctx, ht);
9488 fold_checksum_tree (TYPE_MAIN_VARIANT (expr), ctx, ht);
9489 if (TREE_CODE (expr) == RECORD_TYPE
9490 || TREE_CODE (expr) == UNION_TYPE
9491 || TREE_CODE (expr) == QUAL_UNION_TYPE)
9492 fold_checksum_tree (TYPE_BINFO (expr), ctx, ht);
9493 fold_checksum_tree (TYPE_CONTEXT (expr), ctx, ht);
9502 /* Perform constant folding and related simplification of initializer
9503 expression EXPR. This behaves identically to "fold" but ignores
9504 potential run-time traps and exceptions that fold must preserve. */
9507 fold_initializer (tree expr)
9509 int saved_signaling_nans = flag_signaling_nans;
9510 int saved_trapping_math = flag_trapping_math;
9511 int saved_rounding_math = flag_rounding_math;
9512 int saved_trapv = flag_trapv;
9515 flag_signaling_nans = 0;
9516 flag_trapping_math = 0;
9517 flag_rounding_math = 0;
9520 result = fold (expr);
9522 flag_signaling_nans = saved_signaling_nans;
9523 flag_trapping_math = saved_trapping_math;
9524 flag_rounding_math = saved_rounding_math;
9525 flag_trapv = saved_trapv;
9530 /* Determine if first argument is a multiple of second argument. Return 0 if
9531 it is not, or we cannot easily determined it to be.
9533 An example of the sort of thing we care about (at this point; this routine
9534 could surely be made more general, and expanded to do what the *_DIV_EXPR's
9535 fold cases do now) is discovering that
9537 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
9543 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
9545 This code also handles discovering that
9547 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
9549 is a multiple of 8 so we don't have to worry about dealing with a
9552 Note that we *look* inside a SAVE_EXPR only to determine how it was
9553 calculated; it is not safe for fold to do much of anything else with the
9554 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
9555 at run time. For example, the latter example above *cannot* be implemented
9556 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
9557 evaluation time of the original SAVE_EXPR is not necessarily the same at
9558 the time the new expression is evaluated. The only optimization of this
9559 sort that would be valid is changing
9561 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
9565 SAVE_EXPR (I) * SAVE_EXPR (J)
9567 (where the same SAVE_EXPR (J) is used in the original and the
9568 transformed version). */
9571 multiple_of_p (tree type, tree top, tree bottom)
9573 if (operand_equal_p (top, bottom, 0))
9576 if (TREE_CODE (type) != INTEGER_TYPE)
9579 switch (TREE_CODE (top))
9582 /* Bitwise and provides a power of two multiple. If the mask is
9583 a multiple of BOTTOM then TOP is a multiple of BOTTOM. */
9584 if (!integer_pow2p (bottom))
9589 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
9590 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
9594 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
9595 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
9598 if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
9602 op1 = TREE_OPERAND (top, 1);
9603 /* const_binop may not detect overflow correctly,
9604 so check for it explicitly here. */
9605 if (TYPE_PRECISION (TREE_TYPE (size_one_node))
9606 > TREE_INT_CST_LOW (op1)
9607 && TREE_INT_CST_HIGH (op1) == 0
9608 && 0 != (t1 = fold_convert (type,
9609 const_binop (LSHIFT_EXPR,
9612 && ! TREE_OVERFLOW (t1))
9613 return multiple_of_p (type, t1, bottom);
9618 /* Can't handle conversions from non-integral or wider integral type. */
9619 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
9620 || (TYPE_PRECISION (type)
9621 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
9624 /* .. fall through ... */
9627 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
9630 if (TREE_CODE (bottom) != INTEGER_CST
9631 || (TYPE_UNSIGNED (type)
9632 && (tree_int_cst_sgn (top) < 0
9633 || tree_int_cst_sgn (bottom) < 0)))
9635 return integer_zerop (const_binop (TRUNC_MOD_EXPR,
9643 /* Return true if `t' is known to be non-negative. */
9646 tree_expr_nonnegative_p (tree t)
9648 switch (TREE_CODE (t))
9654 return tree_int_cst_sgn (t) >= 0;
9657 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
9660 if (FLOAT_TYPE_P (TREE_TYPE (t)))
9661 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9662 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9664 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
9665 both unsigned and at least 2 bits shorter than the result. */
9666 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
9667 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
9668 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
9670 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
9671 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
9672 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
9673 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
9675 unsigned int prec = MAX (TYPE_PRECISION (inner1),
9676 TYPE_PRECISION (inner2)) + 1;
9677 return prec < TYPE_PRECISION (TREE_TYPE (t));
9683 if (FLOAT_TYPE_P (TREE_TYPE (t)))
9685 /* x * x for floating point x is always non-negative. */
9686 if (operand_equal_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1), 0))
9688 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9689 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9692 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
9693 both unsigned and their total bits is shorter than the result. */
9694 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
9695 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
9696 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
9698 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
9699 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
9700 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
9701 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
9702 return TYPE_PRECISION (inner1) + TYPE_PRECISION (inner2)
9703 < TYPE_PRECISION (TREE_TYPE (t));
9707 case TRUNC_DIV_EXPR:
9709 case FLOOR_DIV_EXPR:
9710 case ROUND_DIV_EXPR:
9711 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9712 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9714 case TRUNC_MOD_EXPR:
9716 case FLOOR_MOD_EXPR:
9717 case ROUND_MOD_EXPR:
9718 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9721 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9722 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9725 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
9726 || tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9729 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9730 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9734 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
9735 tree outer_type = TREE_TYPE (t);
9737 if (TREE_CODE (outer_type) == REAL_TYPE)
9739 if (TREE_CODE (inner_type) == REAL_TYPE)
9740 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9741 if (TREE_CODE (inner_type) == INTEGER_TYPE)
9743 if (TYPE_UNSIGNED (inner_type))
9745 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9748 else if (TREE_CODE (outer_type) == INTEGER_TYPE)
9750 if (TREE_CODE (inner_type) == REAL_TYPE)
9751 return tree_expr_nonnegative_p (TREE_OPERAND (t,0));
9752 if (TREE_CODE (inner_type) == INTEGER_TYPE)
9753 return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
9754 && TYPE_UNSIGNED (inner_type);
9760 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
9761 && tree_expr_nonnegative_p (TREE_OPERAND (t, 2));
9763 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9765 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9766 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9768 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9769 || tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9771 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9773 return tree_expr_nonnegative_p (expr_last (TREE_OPERAND (t, 1)));
9775 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9776 case NON_LVALUE_EXPR:
9777 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9779 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9783 tree temp = TARGET_EXPR_SLOT (t);
9784 t = TARGET_EXPR_INITIAL (t);
9786 /* If the initializer is non-void, then it's a normal expression
9787 that will be assigned to the slot. */
9788 if (!VOID_TYPE_P (t))
9789 return tree_expr_nonnegative_p (t);
9791 /* Otherwise, the initializer sets the slot in some way. One common
9792 way is an assignment statement at the end of the initializer. */
9795 if (TREE_CODE (t) == BIND_EXPR)
9796 t = expr_last (BIND_EXPR_BODY (t));
9797 else if (TREE_CODE (t) == TRY_FINALLY_EXPR
9798 || TREE_CODE (t) == TRY_CATCH_EXPR)
9799 t = expr_last (TREE_OPERAND (t, 0));
9800 else if (TREE_CODE (t) == STATEMENT_LIST)
9805 if (TREE_CODE (t) == MODIFY_EXPR
9806 && TREE_OPERAND (t, 0) == temp)
9807 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9814 tree fndecl = get_callee_fndecl (t);
9815 tree arglist = TREE_OPERAND (t, 1);
9816 if (fndecl && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
9817 switch (DECL_FUNCTION_CODE (fndecl))
9819 #define CASE_BUILTIN_F(BUILT_IN_FN) \
9820 case BUILT_IN_FN: case BUILT_IN_FN##F: case BUILT_IN_FN##L:
9821 #define CASE_BUILTIN_I(BUILT_IN_FN) \
9822 case BUILT_IN_FN: case BUILT_IN_FN##L: case BUILT_IN_FN##LL:
9824 CASE_BUILTIN_F (BUILT_IN_ACOS)
9825 CASE_BUILTIN_F (BUILT_IN_ACOSH)
9826 CASE_BUILTIN_F (BUILT_IN_CABS)
9827 CASE_BUILTIN_F (BUILT_IN_COSH)
9828 CASE_BUILTIN_F (BUILT_IN_ERFC)
9829 CASE_BUILTIN_F (BUILT_IN_EXP)
9830 CASE_BUILTIN_F (BUILT_IN_EXP10)
9831 CASE_BUILTIN_F (BUILT_IN_EXP2)
9832 CASE_BUILTIN_F (BUILT_IN_FABS)
9833 CASE_BUILTIN_F (BUILT_IN_FDIM)
9834 CASE_BUILTIN_F (BUILT_IN_FREXP)
9835 CASE_BUILTIN_F (BUILT_IN_HYPOT)
9836 CASE_BUILTIN_F (BUILT_IN_POW10)
9837 CASE_BUILTIN_I (BUILT_IN_FFS)
9838 CASE_BUILTIN_I (BUILT_IN_PARITY)
9839 CASE_BUILTIN_I (BUILT_IN_POPCOUNT)
9843 CASE_BUILTIN_F (BUILT_IN_SQRT)
9844 /* sqrt(-0.0) is -0.0. */
9845 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (t))))
9847 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
9849 CASE_BUILTIN_F (BUILT_IN_ASINH)
9850 CASE_BUILTIN_F (BUILT_IN_ATAN)
9851 CASE_BUILTIN_F (BUILT_IN_ATANH)
9852 CASE_BUILTIN_F (BUILT_IN_CBRT)
9853 CASE_BUILTIN_F (BUILT_IN_CEIL)
9854 CASE_BUILTIN_F (BUILT_IN_ERF)
9855 CASE_BUILTIN_F (BUILT_IN_EXPM1)
9856 CASE_BUILTIN_F (BUILT_IN_FLOOR)
9857 CASE_BUILTIN_F (BUILT_IN_FMOD)
9858 CASE_BUILTIN_F (BUILT_IN_LDEXP)
9859 CASE_BUILTIN_F (BUILT_IN_LLRINT)
9860 CASE_BUILTIN_F (BUILT_IN_LLROUND)
9861 CASE_BUILTIN_F (BUILT_IN_LRINT)
9862 CASE_BUILTIN_F (BUILT_IN_LROUND)
9863 CASE_BUILTIN_F (BUILT_IN_MODF)
9864 CASE_BUILTIN_F (BUILT_IN_NEARBYINT)
9865 CASE_BUILTIN_F (BUILT_IN_POW)
9866 CASE_BUILTIN_F (BUILT_IN_RINT)
9867 CASE_BUILTIN_F (BUILT_IN_ROUND)
9868 CASE_BUILTIN_F (BUILT_IN_SIGNBIT)
9869 CASE_BUILTIN_F (BUILT_IN_SINH)
9870 CASE_BUILTIN_F (BUILT_IN_TANH)
9871 CASE_BUILTIN_F (BUILT_IN_TRUNC)
9872 /* True if the 1st argument is nonnegative. */
9873 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
9875 CASE_BUILTIN_F (BUILT_IN_FMAX)
9876 /* True if the 1st OR 2nd arguments are nonnegative. */
9877 return tree_expr_nonnegative_p (TREE_VALUE (arglist))
9878 || tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist)));
9880 CASE_BUILTIN_F (BUILT_IN_FMIN)
9881 /* True if the 1st AND 2nd arguments are nonnegative. */
9882 return tree_expr_nonnegative_p (TREE_VALUE (arglist))
9883 && tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist)));
9885 CASE_BUILTIN_F (BUILT_IN_COPYSIGN)
9886 /* True if the 2nd argument is nonnegative. */
9887 return tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist)));
9891 #undef CASE_BUILTIN_F
9892 #undef CASE_BUILTIN_I
9896 /* ... fall through ... */
9899 if (truth_value_p (TREE_CODE (t)))
9900 /* Truth values evaluate to 0 or 1, which is nonnegative. */
9904 /* We don't know sign of `t', so be conservative and return false. */
9908 /* Return true when T is an address and is known to be nonzero.
9909 For floating point we further ensure that T is not denormal.
9910 Similar logic is present in nonzero_address in rtlanal.h. */
9913 tree_expr_nonzero_p (tree t)
9915 tree type = TREE_TYPE (t);
9917 /* Doing something useful for floating point would need more work. */
9918 if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
9921 switch (TREE_CODE (t))
9924 if (!TYPE_UNSIGNED (type) && !flag_wrapv)
9925 return tree_expr_nonzero_p (TREE_OPERAND (t, 0));
9928 /* We used to test for !integer_zerop here. This does not work correctly
9929 if TREE_CONSTANT_OVERFLOW (t). */
9930 return (TREE_INT_CST_LOW (t) != 0
9931 || TREE_INT_CST_HIGH (t) != 0);
9934 if (!TYPE_UNSIGNED (type) && !flag_wrapv)
9936 /* With the presence of negative values it is hard
9937 to say something. */
9938 if (!tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9939 || !tree_expr_nonnegative_p (TREE_OPERAND (t, 1)))
9941 /* One of operands must be positive and the other non-negative. */
9942 return (tree_expr_nonzero_p (TREE_OPERAND (t, 0))
9943 || tree_expr_nonzero_p (TREE_OPERAND (t, 1)));
9948 if (!TYPE_UNSIGNED (type) && !flag_wrapv)
9950 return (tree_expr_nonzero_p (TREE_OPERAND (t, 0))
9951 && tree_expr_nonzero_p (TREE_OPERAND (t, 1)));
9957 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
9958 tree outer_type = TREE_TYPE (t);
9960 return (TYPE_PRECISION (inner_type) >= TYPE_PRECISION (outer_type)
9961 && tree_expr_nonzero_p (TREE_OPERAND (t, 0)));
9967 tree base = get_base_address (TREE_OPERAND (t, 0));
9972 /* Weak declarations may link to NULL. */
9974 return !DECL_WEAK (base);
9976 /* Constants are never weak. */
9977 if (CONSTANT_CLASS_P (base))
9984 return (tree_expr_nonzero_p (TREE_OPERAND (t, 1))
9985 && tree_expr_nonzero_p (TREE_OPERAND (t, 2)));
9988 return (tree_expr_nonzero_p (TREE_OPERAND (t, 0))
9989 && tree_expr_nonzero_p (TREE_OPERAND (t, 1)));
9992 if (tree_expr_nonzero_p (TREE_OPERAND (t, 0)))
9994 /* When both operands are nonzero, then MAX must be too. */
9995 if (tree_expr_nonzero_p (TREE_OPERAND (t, 1)))
9998 /* MAX where operand 0 is positive is positive. */
9999 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
10001 /* MAX where operand 1 is positive is positive. */
10002 else if (tree_expr_nonzero_p (TREE_OPERAND (t, 1))
10003 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1)))
10007 case COMPOUND_EXPR:
10010 return tree_expr_nonzero_p (TREE_OPERAND (t, 1));
10013 case NON_LVALUE_EXPR:
10014 return tree_expr_nonzero_p (TREE_OPERAND (t, 0));
10017 return tree_expr_nonzero_p (TREE_OPERAND (t, 1))
10018 || tree_expr_nonzero_p (TREE_OPERAND (t, 0));
10026 /* See if we are applying CODE, a relational to the highest or lowest
10027 possible integer of TYPE. If so, then the result is a compile
10031 fold_relational_hi_lo (enum tree_code *code_p, const tree type, tree *op0_p,
10036 enum tree_code code = *code_p;
10037 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (op1)));
10039 if (TREE_CODE (op1) == INTEGER_CST
10040 && ! TREE_CONSTANT_OVERFLOW (op1)
10041 && width <= HOST_BITS_PER_WIDE_INT
10042 && (INTEGRAL_TYPE_P (TREE_TYPE (op1))
10043 || POINTER_TYPE_P (TREE_TYPE (op1))))
10045 unsigned HOST_WIDE_INT signed_max;
10046 unsigned HOST_WIDE_INT max, min;
10048 signed_max = ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1;
10050 if (TYPE_UNSIGNED (TREE_TYPE (op1)))
10052 max = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
10058 min = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
10061 if (TREE_INT_CST_HIGH (op1) == 0
10062 && TREE_INT_CST_LOW (op1) == max)
10066 return omit_one_operand (type, integer_zero_node, op0);
10072 return omit_one_operand (type, integer_one_node, op0);
10078 /* The GE_EXPR and LT_EXPR cases above are not normally
10079 reached because of previous transformations. */
10084 else if (TREE_INT_CST_HIGH (op1) == 0
10085 && TREE_INT_CST_LOW (op1) == max - 1)
10090 *op1_p = const_binop (PLUS_EXPR, op1, integer_one_node, 0);
10094 *op1_p = const_binop (PLUS_EXPR, op1, integer_one_node, 0);
10099 else if (TREE_INT_CST_HIGH (op1) == (min ? -1 : 0)
10100 && TREE_INT_CST_LOW (op1) == min)
10104 return omit_one_operand (type, integer_zero_node, op0);
10111 return omit_one_operand (type, integer_one_node, op0);
10120 else if (TREE_INT_CST_HIGH (op1) == (min ? -1 : 0)
10121 && TREE_INT_CST_LOW (op1) == min + 1)
10126 *op1_p = const_binop (MINUS_EXPR, op1, integer_one_node, 0);
10130 *op1_p = const_binop (MINUS_EXPR, op1, integer_one_node, 0);
10136 else if (TREE_INT_CST_HIGH (op1) == 0
10137 && TREE_INT_CST_LOW (op1) == signed_max
10138 && TYPE_UNSIGNED (TREE_TYPE (op1))
10139 /* signed_type does not work on pointer types. */
10140 && INTEGRAL_TYPE_P (TREE_TYPE (op1)))
10142 /* The following case also applies to X < signed_max+1
10143 and X >= signed_max+1 because previous transformations. */
10144 if (code == LE_EXPR || code == GT_EXPR)
10146 tree st0, st1, exp, retval;
10147 st0 = lang_hooks.types.signed_type (TREE_TYPE (op0));
10148 st1 = lang_hooks.types.signed_type (TREE_TYPE (op1));
10150 exp = build2 (code == LE_EXPR ? GE_EXPR: LT_EXPR,
10152 fold_convert (st0, op0),
10153 fold_convert (st1, integer_zero_node));
10155 retval = fold_binary_to_constant (TREE_CODE (exp),
10157 TREE_OPERAND (exp, 0),
10158 TREE_OPERAND (exp, 1));
10160 /* If we are in gimple form, then returning EXP would create
10161 non-gimple expressions. Clearing it is safe and insures
10162 we do not allow a non-gimple expression to escape. */
10163 if (in_gimple_form)
10166 return (retval ? retval : exp);
10175 /* Given the components of a binary expression CODE, TYPE, OP0 and OP1,
10176 attempt to fold the expression to a constant without modifying TYPE,
10179 If the expression could be simplified to a constant, then return
10180 the constant. If the expression would not be simplified to a
10181 constant, then return NULL_TREE.
10183 Note this is primarily designed to be called after gimplification
10184 of the tree structures and when at least one operand is a constant.
10185 As a result of those simplifying assumptions this routine is far
10186 simpler than the generic fold routine. */
10189 fold_binary_to_constant (enum tree_code code, tree type, tree op0, tree op1)
10196 /* If this is a commutative operation, and ARG0 is a constant, move it
10197 to ARG1 to reduce the number of tests below. */
10198 if (commutative_tree_code (code)
10199 && (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST))
10206 /* If either operand is a complex type, extract its real component. */
10207 if (TREE_CODE (op0) == COMPLEX_CST)
10208 subop0 = TREE_REALPART (op0);
10212 if (TREE_CODE (op1) == COMPLEX_CST)
10213 subop1 = TREE_REALPART (op1);
10217 /* Note if either argument is not a real or integer constant.
10218 With a few exceptions, simplification is limited to cases
10219 where both arguments are constants. */
10220 if ((TREE_CODE (subop0) != INTEGER_CST
10221 && TREE_CODE (subop0) != REAL_CST)
10222 || (TREE_CODE (subop1) != INTEGER_CST
10223 && TREE_CODE (subop1) != REAL_CST))
10229 /* (plus (address) (const_int)) is a constant. */
10230 if (TREE_CODE (op0) == PLUS_EXPR
10231 && TREE_CODE (op1) == INTEGER_CST
10232 && (TREE_CODE (TREE_OPERAND (op0, 0)) == ADDR_EXPR
10233 || (TREE_CODE (TREE_OPERAND (op0, 0)) == NOP_EXPR
10234 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (op0, 0), 0))
10236 && TREE_CODE (TREE_OPERAND (op0, 1)) == INTEGER_CST)
10238 return build2 (PLUS_EXPR, type, TREE_OPERAND (op0, 0),
10239 const_binop (PLUS_EXPR, op1,
10240 TREE_OPERAND (op0, 1), 0));
10248 /* Both arguments are constants. Simplify. */
10249 tem = const_binop (code, op0, op1, 0);
10250 if (tem != NULL_TREE)
10252 /* The return value should always have the same type as
10253 the original expression. */
10254 if (TREE_TYPE (tem) != type)
10255 tem = fold_convert (type, tem);
10262 /* Fold &x - &x. This can happen from &x.foo - &x.
10263 This is unsafe for certain floats even in non-IEEE formats.
10264 In IEEE, it is unsafe because it does wrong for NaNs.
10265 Also note that operand_equal_p is always false if an
10266 operand is volatile. */
10267 if (! FLOAT_TYPE_P (type) && operand_equal_p (op0, op1, 0))
10268 return fold_convert (type, integer_zero_node);
10274 /* Special case multiplication or bitwise AND where one argument
10276 if (! FLOAT_TYPE_P (type) && integer_zerop (op1))
10277 return omit_one_operand (type, op1, op0);
10279 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (op0)))
10280 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (op0)))
10281 && real_zerop (op1))
10282 return omit_one_operand (type, op1, op0);
10287 /* Special case when we know the result will be all ones. */
10288 if (integer_all_onesp (op1))
10289 return omit_one_operand (type, op1, op0);
10293 case TRUNC_DIV_EXPR:
10294 case ROUND_DIV_EXPR:
10295 case FLOOR_DIV_EXPR:
10296 case CEIL_DIV_EXPR:
10297 case EXACT_DIV_EXPR:
10298 case TRUNC_MOD_EXPR:
10299 case ROUND_MOD_EXPR:
10300 case FLOOR_MOD_EXPR:
10301 case CEIL_MOD_EXPR:
10303 /* Division by zero is undefined. */
10304 if (integer_zerop (op1))
10307 if (TREE_CODE (op1) == REAL_CST
10308 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (op1)))
10309 && real_zerop (op1))
10315 if (INTEGRAL_TYPE_P (type)
10316 && operand_equal_p (op1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
10317 return omit_one_operand (type, op1, op0);
10322 if (INTEGRAL_TYPE_P (type)
10323 && TYPE_MAX_VALUE (type)
10324 && operand_equal_p (op1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
10325 return omit_one_operand (type, op1, op0);
10330 /* Optimize -1 >> x for arithmetic right shifts. */
10331 if (integer_all_onesp (op0) && ! TYPE_UNSIGNED (type))
10332 return omit_one_operand (type, op0, op1);
10333 /* ... fall through ... */
10336 if (integer_zerop (op0))
10337 return omit_one_operand (type, op0, op1);
10339 /* Since negative shift count is not well-defined, don't
10340 try to compute it in the compiler. */
10341 if (TREE_CODE (op1) == INTEGER_CST && tree_int_cst_sgn (op1) < 0)
10348 /* -1 rotated either direction by any amount is still -1. */
10349 if (integer_all_onesp (op0))
10350 return omit_one_operand (type, op0, op1);
10352 /* 0 rotated either direction by any amount is still zero. */
10353 if (integer_zerop (op0))
10354 return omit_one_operand (type, op0, op1);
10360 return build_complex (type, op0, op1);
10369 /* If one arg is a real or integer constant, put it last. */
10370 if ((TREE_CODE (op0) == INTEGER_CST
10371 && TREE_CODE (op1) != INTEGER_CST)
10372 || (TREE_CODE (op0) == REAL_CST
10373 && TREE_CODE (op0) != REAL_CST))
10380 code = swap_tree_comparison (code);
10383 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
10384 This transformation affects the cases which are handled in later
10385 optimizations involving comparisons with non-negative constants. */
10386 if (TREE_CODE (op1) == INTEGER_CST
10387 && TREE_CODE (op0) != INTEGER_CST
10388 && tree_int_cst_sgn (op1) > 0)
10394 op1 = const_binop (MINUS_EXPR, op1, integer_one_node, 0);
10399 op1 = const_binop (MINUS_EXPR, op1, integer_one_node, 0);
10407 tem = fold_relational_hi_lo (&code, type, &op0, &op1);
10411 /* Fall through. */
10414 case UNORDERED_EXPR:
10424 return fold_relational_const (code, type, op0, op1);
10427 /* This could probably be handled. */
10430 case TRUTH_AND_EXPR:
10431 /* If second arg is constant zero, result is zero, but first arg
10432 must be evaluated. */
10433 if (integer_zerop (op1))
10434 return omit_one_operand (type, op1, op0);
10435 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
10436 case will be handled here. */
10437 if (integer_zerop (op0))
10438 return omit_one_operand (type, op0, op1);
10439 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
10440 return constant_boolean_node (true, type);
10443 case TRUTH_OR_EXPR:
10444 /* If second arg is constant true, result is true, but we must
10445 evaluate first arg. */
10446 if (TREE_CODE (op1) == INTEGER_CST && ! integer_zerop (op1))
10447 return omit_one_operand (type, op1, op0);
10448 /* Likewise for first arg, but note this only occurs here for
10450 if (TREE_CODE (op0) == INTEGER_CST && ! integer_zerop (op0))
10451 return omit_one_operand (type, op0, op1);
10452 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
10453 return constant_boolean_node (false, type);
10456 case TRUTH_XOR_EXPR:
10457 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
10459 int x = ! integer_zerop (op0) ^ ! integer_zerop (op1);
10460 return constant_boolean_node (x, type);
10469 /* Given the components of a unary expression CODE, TYPE and OP0,
10470 attempt to fold the expression to a constant without modifying
10473 If the expression could be simplified to a constant, then return
10474 the constant. If the expression would not be simplified to a
10475 constant, then return NULL_TREE.
10477 Note this is primarily designed to be called after gimplification
10478 of the tree structures and when op0 is a constant. As a result
10479 of those simplifying assumptions this routine is far simpler than
10480 the generic fold routine. */
10483 fold_unary_to_constant (enum tree_code code, tree type, tree op0)
10485 /* Make sure we have a suitable constant argument. */
10486 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
10490 if (TREE_CODE (op0) == COMPLEX_CST)
10491 subop = TREE_REALPART (op0);
10495 if (TREE_CODE (subop) != INTEGER_CST && TREE_CODE (subop) != REAL_CST)
10504 case FIX_TRUNC_EXPR:
10505 case FIX_FLOOR_EXPR:
10506 case FIX_CEIL_EXPR:
10507 return fold_convert_const (code, type, op0);
10510 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
10511 return fold_negate_const (op0, type);
10516 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
10517 return fold_abs_const (op0, type);
10522 if (TREE_CODE (op0) == INTEGER_CST)
10523 return fold_not_const (op0, type);
10527 case REALPART_EXPR:
10528 if (TREE_CODE (op0) == COMPLEX_CST)
10529 return TREE_REALPART (op0);
10533 case IMAGPART_EXPR:
10534 if (TREE_CODE (op0) == COMPLEX_CST)
10535 return TREE_IMAGPART (op0);
10540 if (TREE_CODE (op0) == COMPLEX_CST
10541 && TREE_CODE (TREE_TYPE (op0)) == COMPLEX_TYPE)
10542 return build_complex (type, TREE_REALPART (op0),
10543 negate_expr (TREE_IMAGPART (op0)));
10551 /* If EXP represents referencing an element in a constant string
10552 (either via pointer arithmetic or array indexing), return the
10553 tree representing the value accessed, otherwise return NULL. */
10556 fold_read_from_constant_string (tree exp)
10558 if (TREE_CODE (exp) == INDIRECT_REF || TREE_CODE (exp) == ARRAY_REF)
10560 tree exp1 = TREE_OPERAND (exp, 0);
10564 if (TREE_CODE (exp) == INDIRECT_REF)
10565 string = string_constant (exp1, &index);
10568 tree low_bound = array_ref_low_bound (exp);
10569 index = fold_convert (sizetype, TREE_OPERAND (exp, 1));
10571 /* Optimize the special-case of a zero lower bound.
10573 We convert the low_bound to sizetype to avoid some problems
10574 with constant folding. (E.g. suppose the lower bound is 1,
10575 and its mode is QI. Without the conversion,l (ARRAY
10576 +(INDEX-(unsigned char)1)) becomes ((ARRAY+(-(unsigned char)1))
10577 +INDEX), which becomes (ARRAY+255+INDEX). Opps!) */
10578 if (! integer_zerop (low_bound))
10579 index = size_diffop (index, fold_convert (sizetype, low_bound));
10585 && TREE_TYPE (exp) == TREE_TYPE (TREE_TYPE (string))
10586 && TREE_CODE (string) == STRING_CST
10587 && TREE_CODE (index) == INTEGER_CST
10588 && compare_tree_int (index, TREE_STRING_LENGTH (string)) < 0
10589 && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (string))))
10591 && (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))) == 1))
10592 return fold_convert (TREE_TYPE (exp),
10593 build_int_cst (NULL_TREE,
10594 (TREE_STRING_POINTER (string)
10595 [TREE_INT_CST_LOW (index)])));
10600 /* Return the tree for neg (ARG0) when ARG0 is known to be either
10601 an integer constant or real constant.
10603 TYPE is the type of the result. */
10606 fold_negate_const (tree arg0, tree type)
10608 tree t = NULL_TREE;
10610 switch (TREE_CODE (arg0))
10614 unsigned HOST_WIDE_INT low;
10615 HOST_WIDE_INT high;
10616 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
10617 TREE_INT_CST_HIGH (arg0),
10619 t = build_int_cst_wide (type, low, high);
10620 t = force_fit_type (t, 1,
10621 (overflow | TREE_OVERFLOW (arg0))
10622 && !TYPE_UNSIGNED (type),
10623 TREE_CONSTANT_OVERFLOW (arg0));
10628 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
10632 gcc_unreachable ();
10638 /* Return the tree for abs (ARG0) when ARG0 is known to be either
10639 an integer constant or real constant.
10641 TYPE is the type of the result. */
10644 fold_abs_const (tree arg0, tree type)
10646 tree t = NULL_TREE;
10648 switch (TREE_CODE (arg0))
10651 /* If the value is unsigned, then the absolute value is
10652 the same as the ordinary value. */
10653 if (TYPE_UNSIGNED (type))
10655 /* Similarly, if the value is non-negative. */
10656 else if (INT_CST_LT (integer_minus_one_node, arg0))
10658 /* If the value is negative, then the absolute value is
10662 unsigned HOST_WIDE_INT low;
10663 HOST_WIDE_INT high;
10664 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
10665 TREE_INT_CST_HIGH (arg0),
10667 t = build_int_cst_wide (type, low, high);
10668 t = force_fit_type (t, -1, overflow | TREE_OVERFLOW (arg0),
10669 TREE_CONSTANT_OVERFLOW (arg0));
10674 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
10675 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
10681 gcc_unreachable ();
10687 /* Return the tree for not (ARG0) when ARG0 is known to be an integer
10688 constant. TYPE is the type of the result. */
10691 fold_not_const (tree arg0, tree type)
10693 tree t = NULL_TREE;
10695 gcc_assert (TREE_CODE (arg0) == INTEGER_CST);
10697 t = build_int_cst_wide (type,
10698 ~ TREE_INT_CST_LOW (arg0),
10699 ~ TREE_INT_CST_HIGH (arg0));
10700 t = force_fit_type (t, 0, TREE_OVERFLOW (arg0),
10701 TREE_CONSTANT_OVERFLOW (arg0));
10706 /* Given CODE, a relational operator, the target type, TYPE and two
10707 constant operands OP0 and OP1, return the result of the
10708 relational operation. If the result is not a compile time
10709 constant, then return NULL_TREE. */
10712 fold_relational_const (enum tree_code code, tree type, tree op0, tree op1)
10714 int result, invert;
10716 /* From here on, the only cases we handle are when the result is
10717 known to be a constant. */
10719 if (TREE_CODE (op0) == REAL_CST && TREE_CODE (op1) == REAL_CST)
10721 const REAL_VALUE_TYPE *c0 = TREE_REAL_CST_PTR (op0);
10722 const REAL_VALUE_TYPE *c1 = TREE_REAL_CST_PTR (op1);
10724 /* Handle the cases where either operand is a NaN. */
10725 if (real_isnan (c0) || real_isnan (c1))
10735 case UNORDERED_EXPR:
10749 if (flag_trapping_math)
10755 gcc_unreachable ();
10758 return constant_boolean_node (result, type);
10761 return constant_boolean_node (real_compare (code, c0, c1), type);
10764 /* From here on we only handle LT, LE, GT, GE, EQ and NE.
10766 To compute GT, swap the arguments and do LT.
10767 To compute GE, do LT and invert the result.
10768 To compute LE, swap the arguments, do LT and invert the result.
10769 To compute NE, do EQ and invert the result.
10771 Therefore, the code below must handle only EQ and LT. */
10773 if (code == LE_EXPR || code == GT_EXPR)
10778 code = swap_tree_comparison (code);
10781 /* Note that it is safe to invert for real values here because we
10782 have already handled the one case that it matters. */
10785 if (code == NE_EXPR || code == GE_EXPR)
10788 code = invert_tree_comparison (code, false);
10791 /* Compute a result for LT or EQ if args permit;
10792 Otherwise return T. */
10793 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
10795 if (code == EQ_EXPR)
10796 result = tree_int_cst_equal (op0, op1);
10797 else if (TYPE_UNSIGNED (TREE_TYPE (op0)))
10798 result = INT_CST_LT_UNSIGNED (op0, op1);
10800 result = INT_CST_LT (op0, op1);
10807 return constant_boolean_node (result, type);
10810 /* Build an expression for the a clean point containing EXPR with type TYPE.
10811 Don't build a cleanup point expression for EXPR which don't have side
10815 fold_build_cleanup_point_expr (tree type, tree expr)
10817 /* If the expression does not have side effects then we don't have to wrap
10818 it with a cleanup point expression. */
10819 if (!TREE_SIDE_EFFECTS (expr))
10822 /* If the expression is a return, check to see if the expression inside the
10823 return has no side effects or the right hand side of the modify expression
10824 inside the return. If either don't have side effects set we don't need to
10825 wrap the expression in a cleanup point expression. Note we don't check the
10826 left hand side of the modify because it should always be a return decl. */
10827 if (TREE_CODE (expr) == RETURN_EXPR)
10829 tree op = TREE_OPERAND (expr, 0);
10830 if (!op || !TREE_SIDE_EFFECTS (op))
10832 op = TREE_OPERAND (op, 1);
10833 if (!TREE_SIDE_EFFECTS (op))
10837 return build1 (CLEANUP_POINT_EXPR, type, expr);
10840 /* Build an expression for the address of T. Folds away INDIRECT_REF to
10841 avoid confusing the gimplify process. */
10844 build_fold_addr_expr_with_type (tree t, tree ptrtype)
10846 /* The size of the object is not relevant when talking about its address. */
10847 if (TREE_CODE (t) == WITH_SIZE_EXPR)
10848 t = TREE_OPERAND (t, 0);
10850 /* Note: doesn't apply to ALIGN_INDIRECT_REF */
10851 if (TREE_CODE (t) == INDIRECT_REF
10852 || TREE_CODE (t) == MISALIGNED_INDIRECT_REF)
10854 t = TREE_OPERAND (t, 0);
10855 if (TREE_TYPE (t) != ptrtype)
10856 t = build1 (NOP_EXPR, ptrtype, t);
10862 while (handled_component_p (base))
10863 base = TREE_OPERAND (base, 0);
10865 TREE_ADDRESSABLE (base) = 1;
10867 t = build1 (ADDR_EXPR, ptrtype, t);
10874 build_fold_addr_expr (tree t)
10876 return build_fold_addr_expr_with_type (t, build_pointer_type (TREE_TYPE (t)));
10879 /* Builds an expression for an indirection through T, simplifying some
10883 build_fold_indirect_ref (tree t)
10885 tree type = TREE_TYPE (TREE_TYPE (t));
10890 if (TREE_CODE (sub) == ADDR_EXPR)
10892 tree op = TREE_OPERAND (sub, 0);
10893 tree optype = TREE_TYPE (op);
10895 if (lang_hooks.types_compatible_p (type, optype))
10897 /* *(foo *)&fooarray => fooarray[0] */
10898 else if (TREE_CODE (optype) == ARRAY_TYPE
10899 && lang_hooks.types_compatible_p (type, TREE_TYPE (optype)))
10900 return build4 (ARRAY_REF, type, op, size_zero_node, NULL_TREE, NULL_TREE);
10903 /* *(foo *)fooarrptr => (*fooarrptr)[0] */
10904 subtype = TREE_TYPE (sub);
10905 if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE
10906 && lang_hooks.types_compatible_p (type, TREE_TYPE (TREE_TYPE (subtype))))
10908 sub = build_fold_indirect_ref (sub);
10909 return build4 (ARRAY_REF, type, sub, size_zero_node, NULL_TREE, NULL_TREE);
10912 return build1 (INDIRECT_REF, type, t);
10915 /* Strip non-trapping, non-side-effecting tree nodes from an expression
10916 whose result is ignored. The type of the returned tree need not be
10917 the same as the original expression. */
10920 fold_ignored_result (tree t)
10922 if (!TREE_SIDE_EFFECTS (t))
10923 return integer_zero_node;
10926 switch (TREE_CODE_CLASS (TREE_CODE (t)))
10929 t = TREE_OPERAND (t, 0);
10933 case tcc_comparison:
10934 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
10935 t = TREE_OPERAND (t, 0);
10936 else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0)))
10937 t = TREE_OPERAND (t, 1);
10942 case tcc_expression:
10943 switch (TREE_CODE (t))
10945 case COMPOUND_EXPR:
10946 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
10948 t = TREE_OPERAND (t, 0);
10952 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1))
10953 || TREE_SIDE_EFFECTS (TREE_OPERAND (t, 2)))
10955 t = TREE_OPERAND (t, 0);
10968 /* Return the value of VALUE, rounded up to a multiple of DIVISOR.
10969 This can only be applied to objects of a sizetype. */
10972 round_up (tree value, int divisor)
10974 tree div = NULL_TREE;
10976 gcc_assert (divisor > 0);
10980 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
10981 have to do anything. Only do this when we are not given a const,
10982 because in that case, this check is more expensive than just
10984 if (TREE_CODE (value) != INTEGER_CST)
10986 div = build_int_cst (TREE_TYPE (value), divisor);
10988 if (multiple_of_p (TREE_TYPE (value), value, div))
10992 /* If divisor is a power of two, simplify this to bit manipulation. */
10993 if (divisor == (divisor & -divisor))
10997 t = build_int_cst (TREE_TYPE (value), divisor - 1);
10998 value = size_binop (PLUS_EXPR, value, t);
10999 t = build_int_cst (TREE_TYPE (value), -divisor);
11000 value = size_binop (BIT_AND_EXPR, value, t);
11005 div = build_int_cst (TREE_TYPE (value), divisor);
11006 value = size_binop (CEIL_DIV_EXPR, value, div);
11007 value = size_binop (MULT_EXPR, value, div);
11013 /* Likewise, but round down. */
11016 round_down (tree value, int divisor)
11018 tree div = NULL_TREE;
11020 gcc_assert (divisor > 0);
11024 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
11025 have to do anything. Only do this when we are not given a const,
11026 because in that case, this check is more expensive than just
11028 if (TREE_CODE (value) != INTEGER_CST)
11030 div = build_int_cst (TREE_TYPE (value), divisor);
11032 if (multiple_of_p (TREE_TYPE (value), value, div))
11036 /* If divisor is a power of two, simplify this to bit manipulation. */
11037 if (divisor == (divisor & -divisor))
11041 t = build_int_cst (TREE_TYPE (value), -divisor);
11042 value = size_binop (BIT_AND_EXPR, value, t);
11047 div = build_int_cst (TREE_TYPE (value), divisor);
11048 value = size_binop (FLOOR_DIV_EXPR, value, div);
11049 value = size_binop (MULT_EXPR, value, div);
11055 /* Returns the pointer to the base of the object addressed by EXP and
11056 extracts the information about the offset of the access, storing it
11057 to PBITPOS and POFFSET. */
11060 split_address_to_core_and_offset (tree exp,
11061 HOST_WIDE_INT *pbitpos, tree *poffset)
11064 enum machine_mode mode;
11065 int unsignedp, volatilep;
11066 HOST_WIDE_INT bitsize;
11068 if (TREE_CODE (exp) == ADDR_EXPR)
11070 core = get_inner_reference (TREE_OPERAND (exp, 0), &bitsize, pbitpos,
11071 poffset, &mode, &unsignedp, &volatilep,
11074 if (TREE_CODE (core) == INDIRECT_REF)
11075 core = TREE_OPERAND (core, 0);
11081 *poffset = NULL_TREE;
11087 /* Returns true if addresses of E1 and E2 differ by a constant, false
11088 otherwise. If they do, E1 - E2 is stored in *DIFF. */
11091 ptr_difference_const (tree e1, tree e2, HOST_WIDE_INT *diff)
11094 HOST_WIDE_INT bitpos1, bitpos2;
11095 tree toffset1, toffset2, tdiff, type;
11097 core1 = split_address_to_core_and_offset (e1, &bitpos1, &toffset1);
11098 core2 = split_address_to_core_and_offset (e2, &bitpos2, &toffset2);
11100 if (bitpos1 % BITS_PER_UNIT != 0
11101 || bitpos2 % BITS_PER_UNIT != 0
11102 || !operand_equal_p (core1, core2, 0))
11105 if (toffset1 && toffset2)
11107 type = TREE_TYPE (toffset1);
11108 if (type != TREE_TYPE (toffset2))
11109 toffset2 = fold_convert (type, toffset2);
11111 tdiff = fold (build2 (MINUS_EXPR, type, toffset1, toffset2));
11112 if (!host_integerp (tdiff, 0))
11115 *diff = tree_low_cst (tdiff, 0);
11117 else if (toffset1 || toffset2)
11119 /* If only one of the offsets is non-constant, the difference cannot
11126 *diff += (bitpos1 - bitpos2) / BITS_PER_UNIT;