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 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 and prior overflow indicator, and
43 forces the value to fit the type. It returns an overflow indicator. */
47 #include "coretypes.h"
58 #include "langhooks.h"
61 /* The following constants represent a bit based encoding of GCC's
62 comparison operators. This encoding simplifies transformations
63 on relational comparison operators, such as AND and OR. */
64 enum comparison_code {
83 static void encode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT, HOST_WIDE_INT);
84 static void decode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
85 static bool negate_mathfn_p (enum built_in_function);
86 static bool negate_expr_p (tree);
87 static tree negate_expr (tree);
88 static tree split_tree (tree, enum tree_code, tree *, tree *, tree *, int);
89 static tree associate_trees (tree, tree, enum tree_code, tree);
90 static tree const_binop (enum tree_code, tree, tree, int);
91 static hashval_t size_htab_hash (const void *);
92 static int size_htab_eq (const void *, const void *);
93 static tree fold_convert_const (enum tree_code, tree, tree);
94 static enum tree_code invert_tree_comparison (enum tree_code, bool);
95 static enum comparison_code comparison_to_compcode (enum tree_code);
96 static enum tree_code compcode_to_comparison (enum comparison_code);
97 static tree combine_comparisons (enum tree_code, enum tree_code,
98 enum tree_code, tree, tree, tree);
99 static int truth_value_p (enum tree_code);
100 static int operand_equal_for_comparison_p (tree, tree, tree);
101 static int twoval_comparison_p (tree, tree *, tree *, int *);
102 static tree eval_subst (tree, tree, tree, tree, tree);
103 static tree pedantic_omit_one_operand (tree, tree, tree);
104 static tree distribute_bit_expr (enum tree_code, tree, tree, tree);
105 static tree make_bit_field_ref (tree, tree, int, int, int);
106 static tree optimize_bit_field_compare (enum tree_code, tree, tree, tree);
107 static tree decode_field_reference (tree, HOST_WIDE_INT *, HOST_WIDE_INT *,
108 enum machine_mode *, int *, int *,
110 static int all_ones_mask_p (tree, int);
111 static tree sign_bit_p (tree, tree);
112 static int simple_operand_p (tree);
113 static tree range_binop (enum tree_code, tree, tree, int, tree, int);
114 static tree make_range (tree, int *, tree *, tree *);
115 static tree build_range_check (tree, tree, int, tree, tree);
116 static int merge_ranges (int *, tree *, tree *, int, tree, tree, int, tree,
118 static tree fold_range_test (tree);
119 static tree fold_cond_expr_with_comparison (tree, tree, tree, tree);
120 static tree unextend (tree, int, int, tree);
121 static tree fold_truthop (enum tree_code, tree, tree, tree);
122 static tree optimize_minmax_comparison (tree);
123 static tree extract_muldiv (tree, tree, enum tree_code, tree);
124 static tree extract_muldiv_1 (tree, tree, enum tree_code, tree);
125 static int multiple_of_p (tree, tree, tree);
126 static tree constant_boolean_node (int, tree);
127 static tree fold_binary_op_with_conditional_arg (enum tree_code, tree, tree,
129 static bool fold_real_zero_addition_p (tree, tree, int);
130 static tree fold_mathfn_compare (enum built_in_function, enum tree_code,
132 static tree fold_inf_compare (enum tree_code, tree, tree, tree);
133 static tree fold_div_compare (enum tree_code, tree, tree, tree);
134 static bool reorder_operands_p (tree, tree);
135 static tree fold_negate_const (tree, tree);
136 static tree fold_not_const (tree, tree);
137 static tree fold_relational_const (enum tree_code, tree, tree, tree);
138 static tree fold_relational_hi_lo (enum tree_code *, const tree,
140 static bool tree_expr_nonzero_p (tree);
142 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
143 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
144 and SUM1. Then this yields nonzero if overflow occurred during the
147 Overflow occurs if A and B have the same sign, but A and SUM differ in
148 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
150 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
152 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
153 We do that by representing the two-word integer in 4 words, with only
154 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
155 number. The value of the word is LOWPART + HIGHPART * BASE. */
158 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
159 #define HIGHPART(x) \
160 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
161 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
163 /* Unpack a two-word integer into 4 words.
164 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
165 WORDS points to the array of HOST_WIDE_INTs. */
168 encode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT low, HOST_WIDE_INT hi)
170 words[0] = LOWPART (low);
171 words[1] = HIGHPART (low);
172 words[2] = LOWPART (hi);
173 words[3] = HIGHPART (hi);
176 /* Pack an array of 4 words into a two-word integer.
177 WORDS points to the array of words.
178 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
181 decode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT *low,
184 *low = words[0] + words[1] * BASE;
185 *hi = words[2] + words[3] * BASE;
188 /* Make the integer constant T valid for its type by setting to 0 or 1 all
189 the bits in the constant that don't belong in the type.
191 Return 1 if a signed overflow occurs, 0 otherwise. If OVERFLOW is
192 nonzero, a signed overflow has already occurred in calculating T, so
196 force_fit_type (tree t, int overflow)
198 unsigned HOST_WIDE_INT low;
202 if (TREE_CODE (t) == REAL_CST)
204 /* ??? Used to check for overflow here via CHECK_FLOAT_TYPE.
205 Consider doing it via real_convert now. */
209 else if (TREE_CODE (t) != INTEGER_CST)
212 low = TREE_INT_CST_LOW (t);
213 high = TREE_INT_CST_HIGH (t);
215 if (POINTER_TYPE_P (TREE_TYPE (t))
216 || TREE_CODE (TREE_TYPE (t)) == OFFSET_TYPE)
219 prec = TYPE_PRECISION (TREE_TYPE (t));
221 /* First clear all bits that are beyond the type's precision. */
223 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
225 else if (prec > HOST_BITS_PER_WIDE_INT)
226 TREE_INT_CST_HIGH (t)
227 &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
230 TREE_INT_CST_HIGH (t) = 0;
231 if (prec < HOST_BITS_PER_WIDE_INT)
232 TREE_INT_CST_LOW (t) &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
235 /* Unsigned types do not suffer sign extension or overflow unless they
237 if (TYPE_UNSIGNED (TREE_TYPE (t))
238 && ! (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
239 && TYPE_IS_SIZETYPE (TREE_TYPE (t))))
242 /* If the value's sign bit is set, extend the sign. */
243 if (prec != 2 * HOST_BITS_PER_WIDE_INT
244 && (prec > HOST_BITS_PER_WIDE_INT
245 ? 0 != (TREE_INT_CST_HIGH (t)
247 << (prec - HOST_BITS_PER_WIDE_INT - 1)))
248 : 0 != (TREE_INT_CST_LOW (t)
249 & ((unsigned HOST_WIDE_INT) 1 << (prec - 1)))))
251 /* Value is negative:
252 set to 1 all the bits that are outside this type's precision. */
253 if (prec > HOST_BITS_PER_WIDE_INT)
254 TREE_INT_CST_HIGH (t)
255 |= ((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
258 TREE_INT_CST_HIGH (t) = -1;
259 if (prec < HOST_BITS_PER_WIDE_INT)
260 TREE_INT_CST_LOW (t) |= ((unsigned HOST_WIDE_INT) (-1) << prec);
264 /* Return nonzero if signed overflow occurred. */
266 ((overflow | (low ^ TREE_INT_CST_LOW (t)) | (high ^ TREE_INT_CST_HIGH (t)))
270 /* Add two doubleword integers with doubleword result.
271 Each argument is given as two `HOST_WIDE_INT' pieces.
272 One argument is L1 and H1; the other, L2 and H2.
273 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
276 add_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
277 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
278 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
280 unsigned HOST_WIDE_INT l;
284 h = h1 + h2 + (l < l1);
288 return OVERFLOW_SUM_SIGN (h1, h2, h);
291 /* Negate a doubleword integer with doubleword result.
292 Return nonzero if the operation overflows, assuming it's signed.
293 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
294 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
297 neg_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
298 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
304 return (*hv & h1) < 0;
314 /* Multiply two doubleword integers with doubleword result.
315 Return nonzero if the operation overflows, assuming it's signed.
316 Each argument is given as two `HOST_WIDE_INT' pieces.
317 One argument is L1 and H1; the other, L2 and H2.
318 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
321 mul_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
322 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
323 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
325 HOST_WIDE_INT arg1[4];
326 HOST_WIDE_INT arg2[4];
327 HOST_WIDE_INT prod[4 * 2];
328 unsigned HOST_WIDE_INT carry;
330 unsigned HOST_WIDE_INT toplow, neglow;
331 HOST_WIDE_INT tophigh, neghigh;
333 encode (arg1, l1, h1);
334 encode (arg2, l2, h2);
336 memset (prod, 0, sizeof prod);
338 for (i = 0; i < 4; i++)
341 for (j = 0; j < 4; j++)
344 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
345 carry += arg1[i] * arg2[j];
346 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
348 prod[k] = LOWPART (carry);
349 carry = HIGHPART (carry);
354 decode (prod, lv, hv); /* This ignores prod[4] through prod[4*2-1] */
356 /* Check for overflow by calculating the top half of the answer in full;
357 it should agree with the low half's sign bit. */
358 decode (prod + 4, &toplow, &tophigh);
361 neg_double (l2, h2, &neglow, &neghigh);
362 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
366 neg_double (l1, h1, &neglow, &neghigh);
367 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
369 return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
372 /* Shift the doubleword integer in L1, H1 left by COUNT places
373 keeping only PREC bits of result.
374 Shift right if COUNT is negative.
375 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
376 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
379 lshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
380 HOST_WIDE_INT count, unsigned int prec,
381 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv, int arith)
383 unsigned HOST_WIDE_INT signmask;
387 rshift_double (l1, h1, -count, prec, lv, hv, arith);
391 if (SHIFT_COUNT_TRUNCATED)
394 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
396 /* Shifting by the host word size is undefined according to the
397 ANSI standard, so we must handle this as a special case. */
401 else if (count >= HOST_BITS_PER_WIDE_INT)
403 *hv = l1 << (count - HOST_BITS_PER_WIDE_INT);
408 *hv = (((unsigned HOST_WIDE_INT) h1 << count)
409 | (l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
413 /* Sign extend all bits that are beyond the precision. */
415 signmask = -((prec > HOST_BITS_PER_WIDE_INT
416 ? ((unsigned HOST_WIDE_INT) *hv
417 >> (prec - HOST_BITS_PER_WIDE_INT - 1))
418 : (*lv >> (prec - 1))) & 1);
420 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
422 else if (prec >= HOST_BITS_PER_WIDE_INT)
424 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
425 *hv |= signmask << (prec - HOST_BITS_PER_WIDE_INT);
430 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
431 *lv |= signmask << prec;
435 /* Shift the doubleword integer in L1, H1 right by COUNT places
436 keeping only PREC bits of result. COUNT must be positive.
437 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
438 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
441 rshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
442 HOST_WIDE_INT count, unsigned int prec,
443 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
446 unsigned HOST_WIDE_INT signmask;
449 ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
452 if (SHIFT_COUNT_TRUNCATED)
455 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
457 /* Shifting by the host word size is undefined according to the
458 ANSI standard, so we must handle this as a special case. */
462 else if (count >= HOST_BITS_PER_WIDE_INT)
465 *lv = (unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT);
469 *hv = (unsigned HOST_WIDE_INT) h1 >> count;
471 | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
474 /* Zero / sign extend all bits that are beyond the precision. */
476 if (count >= (HOST_WIDE_INT)prec)
481 else if ((prec - count) >= 2 * HOST_BITS_PER_WIDE_INT)
483 else if ((prec - count) >= HOST_BITS_PER_WIDE_INT)
485 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - count - HOST_BITS_PER_WIDE_INT));
486 *hv |= signmask << (prec - count - HOST_BITS_PER_WIDE_INT);
491 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << (prec - count));
492 *lv |= signmask << (prec - count);
496 /* Rotate the doubleword integer in L1, H1 left by COUNT places
497 keeping only PREC bits of result.
498 Rotate right if COUNT is negative.
499 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
502 lrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
503 HOST_WIDE_INT count, unsigned int prec,
504 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
506 unsigned HOST_WIDE_INT s1l, s2l;
507 HOST_WIDE_INT s1h, s2h;
513 lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
514 rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
519 /* Rotate the doubleword integer in L1, H1 left by COUNT places
520 keeping only PREC bits of result. COUNT must be positive.
521 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
524 rrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
525 HOST_WIDE_INT count, unsigned int prec,
526 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
528 unsigned HOST_WIDE_INT s1l, s2l;
529 HOST_WIDE_INT s1h, s2h;
535 rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
536 lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
541 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
542 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
543 CODE is a tree code for a kind of division, one of
544 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
546 It controls how the quotient is rounded to an integer.
547 Return nonzero if the operation overflows.
548 UNS nonzero says do unsigned division. */
551 div_and_round_double (enum tree_code code, int uns,
552 unsigned HOST_WIDE_INT lnum_orig, /* num == numerator == dividend */
553 HOST_WIDE_INT hnum_orig,
554 unsigned HOST_WIDE_INT lden_orig, /* den == denominator == divisor */
555 HOST_WIDE_INT hden_orig,
556 unsigned HOST_WIDE_INT *lquo,
557 HOST_WIDE_INT *hquo, unsigned HOST_WIDE_INT *lrem,
561 HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
562 HOST_WIDE_INT den[4], quo[4];
564 unsigned HOST_WIDE_INT work;
565 unsigned HOST_WIDE_INT carry = 0;
566 unsigned HOST_WIDE_INT lnum = lnum_orig;
567 HOST_WIDE_INT hnum = hnum_orig;
568 unsigned HOST_WIDE_INT lden = lden_orig;
569 HOST_WIDE_INT hden = hden_orig;
572 if (hden == 0 && lden == 0)
573 overflow = 1, lden = 1;
575 /* Calculate quotient sign and convert operands to unsigned. */
581 /* (minimum integer) / (-1) is the only overflow case. */
582 if (neg_double (lnum, hnum, &lnum, &hnum)
583 && ((HOST_WIDE_INT) lden & hden) == -1)
589 neg_double (lden, hden, &lden, &hden);
593 if (hnum == 0 && hden == 0)
594 { /* single precision */
596 /* This unsigned division rounds toward zero. */
602 { /* trivial case: dividend < divisor */
603 /* hden != 0 already checked. */
610 memset (quo, 0, sizeof quo);
612 memset (num, 0, sizeof num); /* to zero 9th element */
613 memset (den, 0, sizeof den);
615 encode (num, lnum, hnum);
616 encode (den, lden, hden);
618 /* Special code for when the divisor < BASE. */
619 if (hden == 0 && lden < (unsigned HOST_WIDE_INT) BASE)
621 /* hnum != 0 already checked. */
622 for (i = 4 - 1; i >= 0; i--)
624 work = num[i] + carry * BASE;
625 quo[i] = work / lden;
631 /* Full double precision division,
632 with thanks to Don Knuth's "Seminumerical Algorithms". */
633 int num_hi_sig, den_hi_sig;
634 unsigned HOST_WIDE_INT quo_est, scale;
636 /* Find the highest nonzero divisor digit. */
637 for (i = 4 - 1;; i--)
644 /* Insure that the first digit of the divisor is at least BASE/2.
645 This is required by the quotient digit estimation algorithm. */
647 scale = BASE / (den[den_hi_sig] + 1);
649 { /* scale divisor and dividend */
651 for (i = 0; i <= 4 - 1; i++)
653 work = (num[i] * scale) + carry;
654 num[i] = LOWPART (work);
655 carry = HIGHPART (work);
660 for (i = 0; i <= 4 - 1; i++)
662 work = (den[i] * scale) + carry;
663 den[i] = LOWPART (work);
664 carry = HIGHPART (work);
665 if (den[i] != 0) den_hi_sig = i;
672 for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--)
674 /* Guess the next quotient digit, quo_est, by dividing the first
675 two remaining dividend digits by the high order quotient digit.
676 quo_est is never low and is at most 2 high. */
677 unsigned HOST_WIDE_INT tmp;
679 num_hi_sig = i + den_hi_sig + 1;
680 work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
681 if (num[num_hi_sig] != den[den_hi_sig])
682 quo_est = work / den[den_hi_sig];
686 /* Refine quo_est so it's usually correct, and at most one high. */
687 tmp = work - quo_est * den[den_hi_sig];
689 && (den[den_hi_sig - 1] * quo_est
690 > (tmp * BASE + num[num_hi_sig - 2])))
693 /* Try QUO_EST as the quotient digit, by multiplying the
694 divisor by QUO_EST and subtracting from the remaining dividend.
695 Keep in mind that QUO_EST is the I - 1st digit. */
698 for (j = 0; j <= den_hi_sig; j++)
700 work = quo_est * den[j] + carry;
701 carry = HIGHPART (work);
702 work = num[i + j] - LOWPART (work);
703 num[i + j] = LOWPART (work);
704 carry += HIGHPART (work) != 0;
707 /* If quo_est was high by one, then num[i] went negative and
708 we need to correct things. */
709 if (num[num_hi_sig] < (HOST_WIDE_INT) carry)
712 carry = 0; /* add divisor back in */
713 for (j = 0; j <= den_hi_sig; j++)
715 work = num[i + j] + den[j] + carry;
716 carry = HIGHPART (work);
717 num[i + j] = LOWPART (work);
720 num [num_hi_sig] += carry;
723 /* Store the quotient digit. */
728 decode (quo, lquo, hquo);
731 /* If result is negative, make it so. */
733 neg_double (*lquo, *hquo, lquo, hquo);
735 /* Compute trial remainder: rem = num - (quo * den) */
736 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
737 neg_double (*lrem, *hrem, lrem, hrem);
738 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
743 case TRUNC_MOD_EXPR: /* round toward zero */
744 case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
748 case FLOOR_MOD_EXPR: /* round toward negative infinity */
749 if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
752 add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
760 case CEIL_MOD_EXPR: /* round toward positive infinity */
761 if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
763 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
771 case ROUND_MOD_EXPR: /* round to closest integer */
773 unsigned HOST_WIDE_INT labs_rem = *lrem;
774 HOST_WIDE_INT habs_rem = *hrem;
775 unsigned HOST_WIDE_INT labs_den = lden, ltwice;
776 HOST_WIDE_INT habs_den = hden, htwice;
778 /* Get absolute values. */
780 neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
782 neg_double (lden, hden, &labs_den, &habs_den);
784 /* If (2 * abs (lrem) >= abs (lden)) */
785 mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
786 labs_rem, habs_rem, <wice, &htwice);
788 if (((unsigned HOST_WIDE_INT) habs_den
789 < (unsigned HOST_WIDE_INT) htwice)
790 || (((unsigned HOST_WIDE_INT) habs_den
791 == (unsigned HOST_WIDE_INT) htwice)
792 && (labs_den < ltwice)))
796 add_double (*lquo, *hquo,
797 (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
800 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
812 /* Compute true remainder: rem = num - (quo * den) */
813 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
814 neg_double (*lrem, *hrem, lrem, hrem);
815 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
819 /* Return true if built-in mathematical function specified by CODE
820 preserves the sign of it argument, i.e. -f(x) == f(-x). */
823 negate_mathfn_p (enum built_in_function code)
847 /* Determine whether an expression T can be cheaply negated using
848 the function negate_expr. */
851 negate_expr_p (tree t)
853 unsigned HOST_WIDE_INT val;
860 type = TREE_TYPE (t);
863 switch (TREE_CODE (t))
866 if (TYPE_UNSIGNED (type) || ! flag_trapv)
869 /* Check that -CST will not overflow type. */
870 prec = TYPE_PRECISION (type);
871 if (prec > HOST_BITS_PER_WIDE_INT)
873 if (TREE_INT_CST_LOW (t) != 0)
875 prec -= HOST_BITS_PER_WIDE_INT;
876 val = TREE_INT_CST_HIGH (t);
879 val = TREE_INT_CST_LOW (t);
880 if (prec < HOST_BITS_PER_WIDE_INT)
881 val &= ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
882 return val != ((unsigned HOST_WIDE_INT) 1 << (prec - 1));
889 return negate_expr_p (TREE_REALPART (t))
890 && negate_expr_p (TREE_IMAGPART (t));
893 if (FLOAT_TYPE_P (type) && !flag_unsafe_math_optimizations)
895 /* -(A + B) -> (-B) - A. */
896 if (negate_expr_p (TREE_OPERAND (t, 1))
897 && reorder_operands_p (TREE_OPERAND (t, 0),
898 TREE_OPERAND (t, 1)))
900 /* -(A + B) -> (-A) - B. */
901 return negate_expr_p (TREE_OPERAND (t, 0));
904 /* We can't turn -(A-B) into B-A when we honor signed zeros. */
905 return (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
906 && reorder_operands_p (TREE_OPERAND (t, 0),
907 TREE_OPERAND (t, 1));
910 if (TYPE_UNSIGNED (TREE_TYPE (t)))
916 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
917 return negate_expr_p (TREE_OPERAND (t, 1))
918 || negate_expr_p (TREE_OPERAND (t, 0));
922 /* Negate -((double)float) as (double)(-float). */
923 if (TREE_CODE (type) == REAL_TYPE)
925 tree tem = strip_float_extensions (t);
927 return negate_expr_p (tem);
932 /* Negate -f(x) as f(-x). */
933 if (negate_mathfn_p (builtin_mathfn_code (t)))
934 return negate_expr_p (TREE_VALUE (TREE_OPERAND (t, 1)));
938 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
939 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
941 tree op1 = TREE_OPERAND (t, 1);
942 if (TREE_INT_CST_HIGH (op1) == 0
943 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
944 == TREE_INT_CST_LOW (op1))
955 /* Given T, an expression, return the negation of T. Allow for T to be
956 null, in which case return null. */
967 type = TREE_TYPE (t);
970 switch (TREE_CODE (t))
973 tem = fold_negate_const (t, type);
974 if (! TREE_OVERFLOW (tem)
975 || TYPE_UNSIGNED (type)
981 tem = fold_negate_const (t, type);
982 /* Two's complement FP formats, such as c4x, may overflow. */
983 if (! TREE_OVERFLOW (tem) || ! flag_trapping_math)
984 return fold_convert (type, tem);
989 tree rpart = negate_expr (TREE_REALPART (t));
990 tree ipart = negate_expr (TREE_IMAGPART (t));
992 if ((TREE_CODE (rpart) == REAL_CST
993 && TREE_CODE (ipart) == REAL_CST)
994 || (TREE_CODE (rpart) == INTEGER_CST
995 && TREE_CODE (ipart) == INTEGER_CST))
996 return build_complex (type, rpart, ipart);
1001 return fold_convert (type, TREE_OPERAND (t, 0));
1004 if (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
1006 /* -(A + B) -> (-B) - A. */
1007 if (negate_expr_p (TREE_OPERAND (t, 1))
1008 && reorder_operands_p (TREE_OPERAND (t, 0),
1009 TREE_OPERAND (t, 1)))
1011 tem = negate_expr (TREE_OPERAND (t, 1));
1012 tem = fold (build2 (MINUS_EXPR, TREE_TYPE (t),
1013 tem, TREE_OPERAND (t, 0)));
1014 return fold_convert (type, tem);
1017 /* -(A + B) -> (-A) - B. */
1018 if (negate_expr_p (TREE_OPERAND (t, 0)))
1020 tem = negate_expr (TREE_OPERAND (t, 0));
1021 tem = fold (build2 (MINUS_EXPR, TREE_TYPE (t),
1022 tem, TREE_OPERAND (t, 1)));
1023 return fold_convert (type, tem);
1029 /* - (A - B) -> B - A */
1030 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
1031 && reorder_operands_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1)))
1032 return fold_convert (type,
1033 fold (build2 (MINUS_EXPR, TREE_TYPE (t),
1034 TREE_OPERAND (t, 1),
1035 TREE_OPERAND (t, 0))));
1039 if (TYPE_UNSIGNED (TREE_TYPE (t)))
1045 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
1047 tem = TREE_OPERAND (t, 1);
1048 if (negate_expr_p (tem))
1049 return fold_convert (type,
1050 fold (build2 (TREE_CODE (t), TREE_TYPE (t),
1051 TREE_OPERAND (t, 0),
1052 negate_expr (tem))));
1053 tem = TREE_OPERAND (t, 0);
1054 if (negate_expr_p (tem))
1055 return fold_convert (type,
1056 fold (build2 (TREE_CODE (t), TREE_TYPE (t),
1058 TREE_OPERAND (t, 1))));
1063 /* Convert -((double)float) into (double)(-float). */
1064 if (TREE_CODE (type) == REAL_TYPE)
1066 tem = strip_float_extensions (t);
1067 if (tem != t && negate_expr_p (tem))
1068 return fold_convert (type, negate_expr (tem));
1073 /* Negate -f(x) as f(-x). */
1074 if (negate_mathfn_p (builtin_mathfn_code (t))
1075 && negate_expr_p (TREE_VALUE (TREE_OPERAND (t, 1))))
1077 tree fndecl, arg, arglist;
1079 fndecl = get_callee_fndecl (t);
1080 arg = negate_expr (TREE_VALUE (TREE_OPERAND (t, 1)));
1081 arglist = build_tree_list (NULL_TREE, arg);
1082 return build_function_call_expr (fndecl, arglist);
1087 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1088 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
1090 tree op1 = TREE_OPERAND (t, 1);
1091 if (TREE_INT_CST_HIGH (op1) == 0
1092 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
1093 == TREE_INT_CST_LOW (op1))
1095 tree ntype = TYPE_UNSIGNED (type)
1096 ? lang_hooks.types.signed_type (type)
1097 : lang_hooks.types.unsigned_type (type);
1098 tree temp = fold_convert (ntype, TREE_OPERAND (t, 0));
1099 temp = fold (build2 (RSHIFT_EXPR, ntype, temp, op1));
1100 return fold_convert (type, temp);
1109 tem = fold (build1 (NEGATE_EXPR, TREE_TYPE (t), t));
1110 return fold_convert (type, tem);
1113 /* Split a tree IN into a constant, literal and variable parts that could be
1114 combined with CODE to make IN. "constant" means an expression with
1115 TREE_CONSTANT but that isn't an actual constant. CODE must be a
1116 commutative arithmetic operation. Store the constant part into *CONP,
1117 the literal in *LITP and return the variable part. If a part isn't
1118 present, set it to null. If the tree does not decompose in this way,
1119 return the entire tree as the variable part and the other parts as null.
1121 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
1122 case, we negate an operand that was subtracted. Except if it is a
1123 literal for which we use *MINUS_LITP instead.
1125 If NEGATE_P is true, we are negating all of IN, again except a literal
1126 for which we use *MINUS_LITP instead.
1128 If IN is itself a literal or constant, return it as appropriate.
1130 Note that we do not guarantee that any of the three values will be the
1131 same type as IN, but they will have the same signedness and mode. */
1134 split_tree (tree in, enum tree_code code, tree *conp, tree *litp,
1135 tree *minus_litp, int negate_p)
1143 /* Strip any conversions that don't change the machine mode or signedness. */
1144 STRIP_SIGN_NOPS (in);
1146 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST)
1148 else if (TREE_CODE (in) == code
1149 || (! FLOAT_TYPE_P (TREE_TYPE (in))
1150 /* We can associate addition and subtraction together (even
1151 though the C standard doesn't say so) for integers because
1152 the value is not affected. For reals, the value might be
1153 affected, so we can't. */
1154 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
1155 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
1157 tree op0 = TREE_OPERAND (in, 0);
1158 tree op1 = TREE_OPERAND (in, 1);
1159 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
1160 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
1162 /* First see if either of the operands is a literal, then a constant. */
1163 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
1164 *litp = op0, op0 = 0;
1165 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST)
1166 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
1168 if (op0 != 0 && TREE_CONSTANT (op0))
1169 *conp = op0, op0 = 0;
1170 else if (op1 != 0 && TREE_CONSTANT (op1))
1171 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
1173 /* If we haven't dealt with either operand, this is not a case we can
1174 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1175 if (op0 != 0 && op1 != 0)
1180 var = op1, neg_var_p = neg1_p;
1182 /* Now do any needed negations. */
1184 *minus_litp = *litp, *litp = 0;
1186 *conp = negate_expr (*conp);
1188 var = negate_expr (var);
1190 else if (TREE_CONSTANT (in))
1198 *minus_litp = *litp, *litp = 0;
1199 else if (*minus_litp)
1200 *litp = *minus_litp, *minus_litp = 0;
1201 *conp = negate_expr (*conp);
1202 var = negate_expr (var);
1208 /* Re-associate trees split by the above function. T1 and T2 are either
1209 expressions to associate or null. Return the new expression, if any. If
1210 we build an operation, do it in TYPE and with CODE. */
1213 associate_trees (tree t1, tree t2, enum tree_code code, tree type)
1220 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1221 try to fold this since we will have infinite recursion. But do
1222 deal with any NEGATE_EXPRs. */
1223 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
1224 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1226 if (code == PLUS_EXPR)
1228 if (TREE_CODE (t1) == NEGATE_EXPR)
1229 return build2 (MINUS_EXPR, type, fold_convert (type, t2),
1230 fold_convert (type, TREE_OPERAND (t1, 0)));
1231 else if (TREE_CODE (t2) == NEGATE_EXPR)
1232 return build2 (MINUS_EXPR, type, fold_convert (type, t1),
1233 fold_convert (type, TREE_OPERAND (t2, 0)));
1235 return build2 (code, type, fold_convert (type, t1),
1236 fold_convert (type, t2));
1239 return fold (build2 (code, type, fold_convert (type, t1),
1240 fold_convert (type, t2)));
1243 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1244 to produce a new constant.
1246 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1249 int_const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1251 unsigned HOST_WIDE_INT int1l, int2l;
1252 HOST_WIDE_INT int1h, int2h;
1253 unsigned HOST_WIDE_INT low;
1255 unsigned HOST_WIDE_INT garbagel;
1256 HOST_WIDE_INT garbageh;
1258 tree type = TREE_TYPE (arg1);
1259 int uns = TYPE_UNSIGNED (type);
1261 = (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type));
1263 int no_overflow = 0;
1265 int1l = TREE_INT_CST_LOW (arg1);
1266 int1h = TREE_INT_CST_HIGH (arg1);
1267 int2l = TREE_INT_CST_LOW (arg2);
1268 int2h = TREE_INT_CST_HIGH (arg2);
1273 low = int1l | int2l, hi = int1h | int2h;
1277 low = int1l ^ int2l, hi = int1h ^ int2h;
1281 low = int1l & int2l, hi = int1h & int2h;
1287 /* It's unclear from the C standard whether shifts can overflow.
1288 The following code ignores overflow; perhaps a C standard
1289 interpretation ruling is needed. */
1290 lshift_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1298 lrotate_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1303 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1307 neg_double (int2l, int2h, &low, &hi);
1308 add_double (int1l, int1h, low, hi, &low, &hi);
1309 overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
1313 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1316 case TRUNC_DIV_EXPR:
1317 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1318 case EXACT_DIV_EXPR:
1319 /* This is a shortcut for a common special case. */
1320 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1321 && ! TREE_CONSTANT_OVERFLOW (arg1)
1322 && ! TREE_CONSTANT_OVERFLOW (arg2)
1323 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1325 if (code == CEIL_DIV_EXPR)
1328 low = int1l / int2l, hi = 0;
1332 /* ... fall through ... */
1334 case ROUND_DIV_EXPR:
1335 if (int2h == 0 && int2l == 1)
1337 low = int1l, hi = int1h;
1340 if (int1l == int2l && int1h == int2h
1341 && ! (int1l == 0 && int1h == 0))
1346 overflow = div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
1347 &low, &hi, &garbagel, &garbageh);
1350 case TRUNC_MOD_EXPR:
1351 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1352 /* This is a shortcut for a common special case. */
1353 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1354 && ! TREE_CONSTANT_OVERFLOW (arg1)
1355 && ! TREE_CONSTANT_OVERFLOW (arg2)
1356 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1358 if (code == CEIL_MOD_EXPR)
1360 low = int1l % int2l, hi = 0;
1364 /* ... fall through ... */
1366 case ROUND_MOD_EXPR:
1367 overflow = div_and_round_double (code, uns,
1368 int1l, int1h, int2l, int2h,
1369 &garbagel, &garbageh, &low, &hi);
1375 low = (((unsigned HOST_WIDE_INT) int1h
1376 < (unsigned HOST_WIDE_INT) int2h)
1377 || (((unsigned HOST_WIDE_INT) int1h
1378 == (unsigned HOST_WIDE_INT) int2h)
1381 low = (int1h < int2h
1382 || (int1h == int2h && int1l < int2l));
1384 if (low == (code == MIN_EXPR))
1385 low = int1l, hi = int1h;
1387 low = int2l, hi = int2h;
1394 /* If this is for a sizetype, can be represented as one (signed)
1395 HOST_WIDE_INT word, and doesn't overflow, use size_int since it caches
1398 && ((hi == 0 && (HOST_WIDE_INT) low >= 0)
1399 || (hi == -1 && (HOST_WIDE_INT) low < 0))
1400 && overflow == 0 && ! TREE_OVERFLOW (arg1) && ! TREE_OVERFLOW (arg2))
1401 return size_int_type (low, type);
1404 t = build_int_2 (low, hi);
1405 TREE_TYPE (t) = TREE_TYPE (arg1);
1410 ? (!uns || is_sizetype) && overflow
1411 : (force_fit_type (t, (!uns || is_sizetype) && overflow)
1413 | TREE_OVERFLOW (arg1)
1414 | TREE_OVERFLOW (arg2));
1416 /* If we're doing a size calculation, unsigned arithmetic does overflow.
1417 So check if force_fit_type truncated the value. */
1419 && ! TREE_OVERFLOW (t)
1420 && (TREE_INT_CST_HIGH (t) != hi
1421 || TREE_INT_CST_LOW (t) != low))
1422 TREE_OVERFLOW (t) = 1;
1424 TREE_CONSTANT_OVERFLOW (t) = (TREE_OVERFLOW (t)
1425 | TREE_CONSTANT_OVERFLOW (arg1)
1426 | TREE_CONSTANT_OVERFLOW (arg2));
1430 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1431 constant. We assume ARG1 and ARG2 have the same data type, or at least
1432 are the same kind of constant and the same machine mode.
1434 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1437 const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1442 if (TREE_CODE (arg1) == INTEGER_CST)
1443 return int_const_binop (code, arg1, arg2, notrunc);
1445 if (TREE_CODE (arg1) == REAL_CST)
1447 enum machine_mode mode;
1450 REAL_VALUE_TYPE value;
1453 d1 = TREE_REAL_CST (arg1);
1454 d2 = TREE_REAL_CST (arg2);
1456 type = TREE_TYPE (arg1);
1457 mode = TYPE_MODE (type);
1459 /* Don't perform operation if we honor signaling NaNs and
1460 either operand is a NaN. */
1461 if (HONOR_SNANS (mode)
1462 && (REAL_VALUE_ISNAN (d1) || REAL_VALUE_ISNAN (d2)))
1465 /* Don't perform operation if it would raise a division
1466 by zero exception. */
1467 if (code == RDIV_EXPR
1468 && REAL_VALUES_EQUAL (d2, dconst0)
1469 && (flag_trapping_math || ! MODE_HAS_INFINITIES (mode)))
1472 /* If either operand is a NaN, just return it. Otherwise, set up
1473 for floating-point trap; we return an overflow. */
1474 if (REAL_VALUE_ISNAN (d1))
1476 else if (REAL_VALUE_ISNAN (d2))
1479 REAL_ARITHMETIC (value, code, d1, d2);
1481 t = build_real (type, real_value_truncate (mode, value));
1484 = (force_fit_type (t, 0)
1485 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
1486 TREE_CONSTANT_OVERFLOW (t)
1488 | TREE_CONSTANT_OVERFLOW (arg1)
1489 | TREE_CONSTANT_OVERFLOW (arg2);
1492 if (TREE_CODE (arg1) == COMPLEX_CST)
1494 tree type = TREE_TYPE (arg1);
1495 tree r1 = TREE_REALPART (arg1);
1496 tree i1 = TREE_IMAGPART (arg1);
1497 tree r2 = TREE_REALPART (arg2);
1498 tree i2 = TREE_IMAGPART (arg2);
1504 t = build_complex (type,
1505 const_binop (PLUS_EXPR, r1, r2, notrunc),
1506 const_binop (PLUS_EXPR, i1, i2, notrunc));
1510 t = build_complex (type,
1511 const_binop (MINUS_EXPR, r1, r2, notrunc),
1512 const_binop (MINUS_EXPR, i1, i2, notrunc));
1516 t = build_complex (type,
1517 const_binop (MINUS_EXPR,
1518 const_binop (MULT_EXPR,
1520 const_binop (MULT_EXPR,
1523 const_binop (PLUS_EXPR,
1524 const_binop (MULT_EXPR,
1526 const_binop (MULT_EXPR,
1534 = const_binop (PLUS_EXPR,
1535 const_binop (MULT_EXPR, r2, r2, notrunc),
1536 const_binop (MULT_EXPR, i2, i2, notrunc),
1539 t = build_complex (type,
1541 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1542 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1543 const_binop (PLUS_EXPR,
1544 const_binop (MULT_EXPR, r1, r2,
1546 const_binop (MULT_EXPR, i1, i2,
1549 magsquared, notrunc),
1551 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1552 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1553 const_binop (MINUS_EXPR,
1554 const_binop (MULT_EXPR, i1, r2,
1556 const_binop (MULT_EXPR, r1, i2,
1559 magsquared, notrunc));
1571 /* These are the hash table functions for the hash table of INTEGER_CST
1572 nodes of a sizetype. */
1574 /* Return the hash code code X, an INTEGER_CST. */
1577 size_htab_hash (const void *x)
1581 return (TREE_INT_CST_HIGH (t) ^ TREE_INT_CST_LOW (t)
1582 ^ htab_hash_pointer (TREE_TYPE (t))
1583 ^ (TREE_OVERFLOW (t) << 20));
1586 /* Return nonzero if the value represented by *X (an INTEGER_CST tree node)
1587 is the same as that given by *Y, which is the same. */
1590 size_htab_eq (const void *x, const void *y)
1595 return (TREE_INT_CST_HIGH (xt) == TREE_INT_CST_HIGH (yt)
1596 && TREE_INT_CST_LOW (xt) == TREE_INT_CST_LOW (yt)
1597 && TREE_TYPE (xt) == TREE_TYPE (yt)
1598 && TREE_OVERFLOW (xt) == TREE_OVERFLOW (yt));
1601 /* Return an INTEGER_CST with value whose low-order HOST_BITS_PER_WIDE_INT
1602 bits are given by NUMBER and of the sizetype represented by KIND. */
1605 size_int_kind (HOST_WIDE_INT number, enum size_type_kind kind)
1607 return size_int_type (number, sizetype_tab[(int) kind]);
1610 /* Likewise, but the desired type is specified explicitly. */
1612 static GTY (()) tree new_const;
1613 static GTY ((if_marked ("ggc_marked_p"), param_is (union tree_node)))
1617 size_int_type (HOST_WIDE_INT number, tree type)
1623 size_htab = htab_create_ggc (1024, size_htab_hash, size_htab_eq, NULL);
1624 new_const = make_node (INTEGER_CST);
1627 /* Adjust NEW_CONST to be the constant we want. If it's already in the
1628 hash table, we return the value from the hash table. Otherwise, we
1629 place that in the hash table and make a new node for the next time. */
1630 TREE_INT_CST_LOW (new_const) = number;
1631 TREE_INT_CST_HIGH (new_const) = number < 0 ? -1 : 0;
1632 TREE_TYPE (new_const) = type;
1633 TREE_OVERFLOW (new_const) = TREE_CONSTANT_OVERFLOW (new_const)
1634 = force_fit_type (new_const, 0);
1636 slot = htab_find_slot (size_htab, new_const, INSERT);
1642 new_const = make_node (INTEGER_CST);
1646 return (tree) *slot;
1649 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1650 is a tree code. The type of the result is taken from the operands.
1651 Both must be the same type integer type and it must be a size type.
1652 If the operands are constant, so is the result. */
1655 size_binop (enum tree_code code, tree arg0, tree arg1)
1657 tree type = TREE_TYPE (arg0);
1659 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1660 || type != TREE_TYPE (arg1))
1663 /* Handle the special case of two integer constants faster. */
1664 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1666 /* And some specific cases even faster than that. */
1667 if (code == PLUS_EXPR && integer_zerop (arg0))
1669 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1670 && integer_zerop (arg1))
1672 else if (code == MULT_EXPR && integer_onep (arg0))
1675 /* Handle general case of two integer constants. */
1676 return int_const_binop (code, arg0, arg1, 0);
1679 if (arg0 == error_mark_node || arg1 == error_mark_node)
1680 return error_mark_node;
1682 return fold (build2 (code, type, arg0, arg1));
1685 /* Given two values, either both of sizetype or both of bitsizetype,
1686 compute the difference between the two values. Return the value
1687 in signed type corresponding to the type of the operands. */
1690 size_diffop (tree arg0, tree arg1)
1692 tree type = TREE_TYPE (arg0);
1695 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1696 || type != TREE_TYPE (arg1))
1699 /* If the type is already signed, just do the simple thing. */
1700 if (!TYPE_UNSIGNED (type))
1701 return size_binop (MINUS_EXPR, arg0, arg1);
1703 ctype = (type == bitsizetype || type == ubitsizetype
1704 ? sbitsizetype : ssizetype);
1706 /* If either operand is not a constant, do the conversions to the signed
1707 type and subtract. The hardware will do the right thing with any
1708 overflow in the subtraction. */
1709 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
1710 return size_binop (MINUS_EXPR, fold_convert (ctype, arg0),
1711 fold_convert (ctype, arg1));
1713 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
1714 Otherwise, subtract the other way, convert to CTYPE (we know that can't
1715 overflow) and negate (which can't either). Special-case a result
1716 of zero while we're here. */
1717 if (tree_int_cst_equal (arg0, arg1))
1718 return fold_convert (ctype, integer_zero_node);
1719 else if (tree_int_cst_lt (arg1, arg0))
1720 return fold_convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
1722 return size_binop (MINUS_EXPR, fold_convert (ctype, integer_zero_node),
1723 fold_convert (ctype, size_binop (MINUS_EXPR,
1728 /* Attempt to fold type conversion operation CODE of expression ARG1 to
1729 type TYPE. If no simplification can be done return NULL_TREE. */
1732 fold_convert_const (enum tree_code code, tree type, tree arg1)
1737 if (TREE_TYPE (arg1) == type)
1740 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
1742 if (TREE_CODE (arg1) == INTEGER_CST)
1744 /* If we would build a constant wider than GCC supports,
1745 leave the conversion unfolded. */
1746 if (TYPE_PRECISION (type) > 2 * HOST_BITS_PER_WIDE_INT)
1749 /* If we are trying to make a sizetype for a small integer, use
1750 size_int to pick up cached types to reduce duplicate nodes. */
1751 if (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type)
1752 && !TREE_CONSTANT_OVERFLOW (arg1)
1753 && compare_tree_int (arg1, 10000) < 0)
1754 return size_int_type (TREE_INT_CST_LOW (arg1), type);
1756 /* Given an integer constant, make new constant with new type,
1757 appropriately sign-extended or truncated. */
1758 t = build_int_2 (TREE_INT_CST_LOW (arg1),
1759 TREE_INT_CST_HIGH (arg1));
1760 TREE_TYPE (t) = type;
1761 /* Indicate an overflow if (1) ARG1 already overflowed,
1762 or (2) force_fit_type indicates an overflow.
1763 Tell force_fit_type that an overflow has already occurred
1764 if ARG1 is a too-large unsigned value and T is signed.
1765 But don't indicate an overflow if converting a pointer. */
1767 = ((force_fit_type (t,
1768 (TREE_INT_CST_HIGH (arg1) < 0
1769 && (TYPE_UNSIGNED (type)
1770 < TYPE_UNSIGNED (TREE_TYPE (arg1)))))
1771 && ! POINTER_TYPE_P (TREE_TYPE (arg1)))
1772 || TREE_OVERFLOW (arg1));
1773 TREE_CONSTANT_OVERFLOW (t)
1774 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1777 else if (TREE_CODE (arg1) == REAL_CST)
1779 /* The following code implements the floating point to integer
1780 conversion rules required by the Java Language Specification,
1781 that IEEE NaNs are mapped to zero and values that overflow
1782 the target precision saturate, i.e. values greater than
1783 INT_MAX are mapped to INT_MAX, and values less than INT_MIN
1784 are mapped to INT_MIN. These semantics are allowed by the
1785 C and C++ standards that simply state that the behavior of
1786 FP-to-integer conversion is unspecified upon overflow. */
1788 HOST_WIDE_INT high, low;
1791 REAL_VALUE_TYPE x = TREE_REAL_CST (arg1);
1795 case FIX_TRUNC_EXPR:
1796 real_trunc (&r, VOIDmode, &x);
1800 real_ceil (&r, VOIDmode, &x);
1803 case FIX_FLOOR_EXPR:
1804 real_floor (&r, VOIDmode, &x);
1807 case FIX_ROUND_EXPR:
1808 real_round (&r, VOIDmode, &x);
1815 /* If R is NaN, return zero and show we have an overflow. */
1816 if (REAL_VALUE_ISNAN (r))
1823 /* See if R is less than the lower bound or greater than the
1828 tree lt = TYPE_MIN_VALUE (type);
1829 REAL_VALUE_TYPE l = real_value_from_int_cst (NULL_TREE, lt);
1830 if (REAL_VALUES_LESS (r, l))
1833 high = TREE_INT_CST_HIGH (lt);
1834 low = TREE_INT_CST_LOW (lt);
1840 tree ut = TYPE_MAX_VALUE (type);
1843 REAL_VALUE_TYPE u = real_value_from_int_cst (NULL_TREE, ut);
1844 if (REAL_VALUES_LESS (u, r))
1847 high = TREE_INT_CST_HIGH (ut);
1848 low = TREE_INT_CST_LOW (ut);
1854 REAL_VALUE_TO_INT (&low, &high, r);
1856 t = build_int_2 (low, high);
1857 TREE_TYPE (t) = type;
1859 = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
1860 TREE_CONSTANT_OVERFLOW (t)
1861 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1865 else if (TREE_CODE (type) == REAL_TYPE)
1867 if (TREE_CODE (arg1) == INTEGER_CST)
1868 return build_real_from_int_cst (type, arg1);
1869 if (TREE_CODE (arg1) == REAL_CST)
1871 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
1873 /* We make a copy of ARG1 so that we don't modify an
1874 existing constant tree. */
1875 t = copy_node (arg1);
1876 TREE_TYPE (t) = type;
1880 t = build_real (type,
1881 real_value_truncate (TYPE_MODE (type),
1882 TREE_REAL_CST (arg1)));
1885 = TREE_OVERFLOW (arg1) | force_fit_type (t, 0);
1886 TREE_CONSTANT_OVERFLOW (t)
1887 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1894 /* Convert expression ARG to type TYPE. Used by the middle-end for
1895 simple conversions in preference to calling the front-end's convert. */
1898 fold_convert (tree type, tree arg)
1900 tree orig = TREE_TYPE (arg);
1906 if (TREE_CODE (arg) == ERROR_MARK
1907 || TREE_CODE (type) == ERROR_MARK
1908 || TREE_CODE (orig) == ERROR_MARK)
1909 return error_mark_node;
1911 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig)
1912 || lang_hooks.types_compatible_p (TYPE_MAIN_VARIANT (type),
1913 TYPE_MAIN_VARIANT (orig)))
1914 return fold (build1 (NOP_EXPR, type, arg));
1916 if (INTEGRAL_TYPE_P (type) || POINTER_TYPE_P (type)
1917 || TREE_CODE (type) == OFFSET_TYPE)
1919 if (TREE_CODE (arg) == INTEGER_CST)
1921 tem = fold_convert_const (NOP_EXPR, type, arg);
1922 if (tem != NULL_TREE)
1925 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
1926 || TREE_CODE (orig) == OFFSET_TYPE)
1927 return fold (build1 (NOP_EXPR, type, arg));
1928 if (TREE_CODE (orig) == COMPLEX_TYPE)
1930 tem = fold (build1 (REALPART_EXPR, TREE_TYPE (orig), arg));
1931 return fold_convert (type, tem);
1933 if (TREE_CODE (orig) == VECTOR_TYPE
1934 && tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)))
1935 return fold (build1 (NOP_EXPR, type, arg));
1937 else if (TREE_CODE (type) == REAL_TYPE)
1939 if (TREE_CODE (arg) == INTEGER_CST)
1941 tem = fold_convert_const (FLOAT_EXPR, type, arg);
1942 if (tem != NULL_TREE)
1945 else if (TREE_CODE (arg) == REAL_CST)
1947 tem = fold_convert_const (NOP_EXPR, type, arg);
1948 if (tem != NULL_TREE)
1952 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig))
1953 return fold (build1 (FLOAT_EXPR, type, arg));
1954 if (TREE_CODE (orig) == REAL_TYPE)
1955 return fold (build1 (flag_float_store ? CONVERT_EXPR : NOP_EXPR,
1957 if (TREE_CODE (orig) == COMPLEX_TYPE)
1959 tem = fold (build1 (REALPART_EXPR, TREE_TYPE (orig), arg));
1960 return fold_convert (type, tem);
1963 else if (TREE_CODE (type) == COMPLEX_TYPE)
1965 if (INTEGRAL_TYPE_P (orig)
1966 || POINTER_TYPE_P (orig)
1967 || TREE_CODE (orig) == REAL_TYPE)
1968 return build2 (COMPLEX_EXPR, type,
1969 fold_convert (TREE_TYPE (type), arg),
1970 fold_convert (TREE_TYPE (type), integer_zero_node));
1971 if (TREE_CODE (orig) == COMPLEX_TYPE)
1975 if (TREE_CODE (arg) == COMPLEX_EXPR)
1977 rpart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 0));
1978 ipart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 1));
1979 return fold (build2 (COMPLEX_EXPR, type, rpart, ipart));
1982 arg = save_expr (arg);
1983 rpart = fold (build1 (REALPART_EXPR, TREE_TYPE (orig), arg));
1984 ipart = fold (build1 (IMAGPART_EXPR, TREE_TYPE (orig), arg));
1985 rpart = fold_convert (TREE_TYPE (type), rpart);
1986 ipart = fold_convert (TREE_TYPE (type), ipart);
1987 return fold (build2 (COMPLEX_EXPR, type, rpart, ipart));
1990 else if (TREE_CODE (type) == VECTOR_TYPE)
1992 if ((INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig))
1993 && tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)))
1994 return fold (build1 (NOP_EXPR, type, arg));
1995 if (TREE_CODE (orig) == VECTOR_TYPE
1996 && tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)))
1997 return fold (build1 (NOP_EXPR, type, arg));
1999 else if (VOID_TYPE_P (type))
2000 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 /* We only need to wrap lvalue tree codes. */
2010 switch (TREE_CODE (x))
2022 case ARRAY_RANGE_REF:
2028 case PREINCREMENT_EXPR:
2029 case PREDECREMENT_EXPR:
2032 case TRY_CATCH_EXPR:
2033 case WITH_CLEANUP_EXPR:
2044 /* Assume the worst for front-end tree codes. */
2045 if ((int)TREE_CODE (x) >= NUM_TREE_CODES)
2049 return build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
2052 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
2053 Zero means allow extended lvalues. */
2055 int pedantic_lvalues;
2057 /* When pedantic, return an expr equal to X but certainly not valid as a
2058 pedantic lvalue. Otherwise, return X. */
2061 pedantic_non_lvalue (tree x)
2063 if (pedantic_lvalues)
2064 return non_lvalue (x);
2069 /* Given a tree comparison code, return the code that is the logical inverse
2070 of the given code. It is not safe to do this for floating-point
2071 comparisons, except for NE_EXPR and EQ_EXPR, so we receive a machine mode
2072 as well: if reversing the comparison is unsafe, return ERROR_MARK. */
2074 static enum tree_code
2075 invert_tree_comparison (enum tree_code code, bool honor_nans)
2077 if (honor_nans && flag_trapping_math)
2087 return honor_nans ? UNLE_EXPR : LE_EXPR;
2089 return honor_nans ? UNLT_EXPR : LT_EXPR;
2091 return honor_nans ? UNGE_EXPR : GE_EXPR;
2093 return honor_nans ? UNGT_EXPR : GT_EXPR;
2107 return UNORDERED_EXPR;
2108 case UNORDERED_EXPR:
2109 return ORDERED_EXPR;
2115 /* Similar, but return the comparison that results if the operands are
2116 swapped. This is safe for floating-point. */
2119 swap_tree_comparison (enum tree_code code)
2140 /* Convert a comparison tree code from an enum tree_code representation
2141 into a compcode bit-based encoding. This function is the inverse of
2142 compcode_to_comparison. */
2144 static enum comparison_code
2145 comparison_to_compcode (enum tree_code code)
2162 return COMPCODE_ORD;
2163 case UNORDERED_EXPR:
2164 return COMPCODE_UNORD;
2166 return COMPCODE_UNLT;
2168 return COMPCODE_UNEQ;
2170 return COMPCODE_UNLE;
2172 return COMPCODE_UNGT;
2174 return COMPCODE_LTGT;
2176 return COMPCODE_UNGE;
2182 /* Convert a compcode bit-based encoding of a comparison operator back
2183 to GCC's enum tree_code representation. This function is the
2184 inverse of comparison_to_compcode. */
2186 static enum tree_code
2187 compcode_to_comparison (enum comparison_code code)
2204 return ORDERED_EXPR;
2205 case COMPCODE_UNORD:
2206 return UNORDERED_EXPR;
2224 /* Return a tree for the comparison which is the combination of
2225 doing the AND or OR (depending on CODE) of the two operations LCODE
2226 and RCODE on the identical operands LL_ARG and LR_ARG. Take into account
2227 the possibility of trapping if the mode has NaNs, and return NULL_TREE
2228 if this makes the transformation invalid. */
2231 combine_comparisons (enum tree_code code, enum tree_code lcode,
2232 enum tree_code rcode, tree truth_type,
2233 tree ll_arg, tree lr_arg)
2235 bool honor_nans = HONOR_NANS (TYPE_MODE (TREE_TYPE (ll_arg)));
2236 enum comparison_code lcompcode = comparison_to_compcode (lcode);
2237 enum comparison_code rcompcode = comparison_to_compcode (rcode);
2238 enum comparison_code compcode;
2242 case TRUTH_AND_EXPR: case TRUTH_ANDIF_EXPR:
2243 compcode = lcompcode & rcompcode;
2246 case TRUTH_OR_EXPR: case TRUTH_ORIF_EXPR:
2247 compcode = lcompcode | rcompcode;
2256 /* Eliminate unordered comparisons, as well as LTGT and ORD
2257 which are not used unless the mode has NaNs. */
2258 compcode &= ~COMPCODE_UNORD;
2259 if (compcode == COMPCODE_LTGT)
2260 compcode = COMPCODE_NE;
2261 else if (compcode == COMPCODE_ORD)
2262 compcode = COMPCODE_TRUE;
2264 else if (flag_trapping_math)
2266 /* Check that the original operation and the optimized ones will trap
2267 under the same condition. */
2268 bool ltrap = (lcompcode & COMPCODE_UNORD) == 0
2269 && (lcompcode != COMPCODE_EQ)
2270 && (lcompcode != COMPCODE_ORD);
2271 bool rtrap = (rcompcode & COMPCODE_UNORD) == 0
2272 && (rcompcode != COMPCODE_EQ)
2273 && (rcompcode != COMPCODE_ORD);
2274 bool trap = (compcode & COMPCODE_UNORD) == 0
2275 && (compcode != COMPCODE_EQ)
2276 && (compcode != COMPCODE_ORD);
2278 /* In a short-circuited boolean expression the LHS might be
2279 such that the RHS, if evaluated, will never trap. For
2280 example, in ORD (x, y) && (x < y), we evaluate the RHS only
2281 if neither x nor y is NaN. (This is a mixed blessing: for
2282 example, the expression above will never trap, hence
2283 optimizing it to x < y would be invalid). */
2284 if ((code == TRUTH_ORIF_EXPR && (lcompcode & COMPCODE_UNORD))
2285 || (code == TRUTH_ANDIF_EXPR && !(lcompcode & COMPCODE_UNORD)))
2288 /* If the comparison was short-circuited, and only the RHS
2289 trapped, we may now generate a spurious trap. */
2291 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2294 /* If we changed the conditions that cause a trap, we lose. */
2295 if ((ltrap || rtrap) != trap)
2299 if (compcode == COMPCODE_TRUE)
2300 return constant_boolean_node (true, truth_type);
2301 else if (compcode == COMPCODE_FALSE)
2302 return constant_boolean_node (false, truth_type);
2304 return fold (build2 (compcode_to_comparison (compcode),
2305 truth_type, ll_arg, lr_arg));
2308 /* Return nonzero if CODE is a tree code that represents a truth value. */
2311 truth_value_p (enum tree_code code)
2313 return (TREE_CODE_CLASS (code) == '<'
2314 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2315 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2316 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
2319 /* Return nonzero if two operands (typically of the same tree node)
2320 are necessarily equal. If either argument has side-effects this
2321 function returns zero. FLAGS modifies behavior as follows:
2323 If OEP_ONLY_CONST is set, only return nonzero for constants.
2324 This function tests whether the operands are indistinguishable;
2325 it does not test whether they are equal using C's == operation.
2326 The distinction is important for IEEE floating point, because
2327 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2328 (2) two NaNs may be indistinguishable, but NaN!=NaN.
2330 If OEP_ONLY_CONST is unset, a VAR_DECL is considered equal to itself
2331 even though it may hold multiple values during a function.
2332 This is because a GCC tree node guarantees that nothing else is
2333 executed between the evaluation of its "operands" (which may often
2334 be evaluated in arbitrary order). Hence if the operands themselves
2335 don't side-effect, the VAR_DECLs, PARM_DECLs etc... must hold the
2336 same value in each operand/subexpression. Hence leaving OEP_ONLY_CONST
2337 unset means assuming isochronic (or instantaneous) tree equivalence.
2338 Unless comparing arbitrary expression trees, such as from different
2339 statements, this flag can usually be left unset.
2341 If OEP_PURE_SAME is set, then pure functions with identical arguments
2342 are considered the same. It is used when the caller has other ways
2343 to ensure that global memory is unchanged in between. */
2346 operand_equal_p (tree arg0, tree arg1, unsigned int flags)
2348 /* If one is specified and the other isn't, they aren't equal and if
2349 neither is specified, they are.
2351 ??? This is temporary and is meant only to handle the cases of the
2352 optional operands for COMPONENT_REF and ARRAY_REF. */
2353 if ((arg0 && !arg1) || (!arg0 && arg1))
2355 else if (!arg0 && !arg1)
2357 /* If either is ERROR_MARK, they aren't equal. */
2358 else if (TREE_CODE (arg0) == ERROR_MARK || TREE_CODE (arg1) == ERROR_MARK)
2361 /* If both types don't have the same signedness, then we can't consider
2362 them equal. We must check this before the STRIP_NOPS calls
2363 because they may change the signedness of the arguments. */
2364 if (TYPE_UNSIGNED (TREE_TYPE (arg0)) != TYPE_UNSIGNED (TREE_TYPE (arg1)))
2370 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2371 /* This is needed for conversions and for COMPONENT_REF.
2372 Might as well play it safe and always test this. */
2373 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
2374 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
2375 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
2378 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
2379 We don't care about side effects in that case because the SAVE_EXPR
2380 takes care of that for us. In all other cases, two expressions are
2381 equal if they have no side effects. If we have two identical
2382 expressions with side effects that should be treated the same due
2383 to the only side effects being identical SAVE_EXPR's, that will
2384 be detected in the recursive calls below. */
2385 if (arg0 == arg1 && ! (flags & OEP_ONLY_CONST)
2386 && (TREE_CODE (arg0) == SAVE_EXPR
2387 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
2390 /* Next handle constant cases, those for which we can return 1 even
2391 if ONLY_CONST is set. */
2392 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
2393 switch (TREE_CODE (arg0))
2396 return (! TREE_CONSTANT_OVERFLOW (arg0)
2397 && ! TREE_CONSTANT_OVERFLOW (arg1)
2398 && tree_int_cst_equal (arg0, arg1));
2401 return (! TREE_CONSTANT_OVERFLOW (arg0)
2402 && ! TREE_CONSTANT_OVERFLOW (arg1)
2403 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
2404 TREE_REAL_CST (arg1)));
2410 if (TREE_CONSTANT_OVERFLOW (arg0)
2411 || TREE_CONSTANT_OVERFLOW (arg1))
2414 v1 = TREE_VECTOR_CST_ELTS (arg0);
2415 v2 = TREE_VECTOR_CST_ELTS (arg1);
2418 if (!operand_equal_p (TREE_VALUE (v1), TREE_VALUE (v2),
2421 v1 = TREE_CHAIN (v1);
2422 v2 = TREE_CHAIN (v2);
2429 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
2431 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
2435 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
2436 && ! memcmp (TREE_STRING_POINTER (arg0),
2437 TREE_STRING_POINTER (arg1),
2438 TREE_STRING_LENGTH (arg0)));
2441 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
2447 if (flags & OEP_ONLY_CONST)
2450 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
2453 /* Two conversions are equal only if signedness and modes match. */
2454 if ((TREE_CODE (arg0) == NOP_EXPR || TREE_CODE (arg0) == CONVERT_EXPR)
2455 && (TYPE_UNSIGNED (TREE_TYPE (arg0))
2456 != TYPE_UNSIGNED (TREE_TYPE (arg1))))
2459 return operand_equal_p (TREE_OPERAND (arg0, 0),
2460 TREE_OPERAND (arg1, 0), flags);
2464 if (operand_equal_p (TREE_OPERAND (arg0, 0),
2465 TREE_OPERAND (arg1, 0), flags)
2466 && operand_equal_p (TREE_OPERAND (arg0, 1),
2467 TREE_OPERAND (arg1, 1), flags))
2470 /* For commutative ops, allow the other order. */
2471 return (commutative_tree_code (TREE_CODE (arg0))
2472 && operand_equal_p (TREE_OPERAND (arg0, 0),
2473 TREE_OPERAND (arg1, 1), flags)
2474 && operand_equal_p (TREE_OPERAND (arg0, 1),
2475 TREE_OPERAND (arg1, 0), flags));
2478 /* If either of the pointer (or reference) expressions we are
2479 dereferencing contain a side effect, these cannot be equal. */
2480 if (TREE_SIDE_EFFECTS (arg0)
2481 || TREE_SIDE_EFFECTS (arg1))
2484 switch (TREE_CODE (arg0))
2489 return operand_equal_p (TREE_OPERAND (arg0, 0),
2490 TREE_OPERAND (arg1, 0), flags);
2493 case ARRAY_RANGE_REF:
2494 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2495 TREE_OPERAND (arg1, 0), flags)
2496 && operand_equal_p (TREE_OPERAND (arg0, 1),
2497 TREE_OPERAND (arg1, 1), flags)
2498 && operand_equal_p (TREE_OPERAND (arg0, 2),
2499 TREE_OPERAND (arg1, 2), flags)
2500 && operand_equal_p (TREE_OPERAND (arg0, 3),
2501 TREE_OPERAND (arg1, 3), flags));
2505 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2506 TREE_OPERAND (arg1, 0), flags)
2507 && operand_equal_p (TREE_OPERAND (arg0, 1),
2508 TREE_OPERAND (arg1, 1), flags)
2509 && operand_equal_p (TREE_OPERAND (arg0, 2),
2510 TREE_OPERAND (arg1, 2), flags));
2514 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2515 TREE_OPERAND (arg1, 0), flags)
2516 && operand_equal_p (TREE_OPERAND (arg0, 1),
2517 TREE_OPERAND (arg1, 1), flags)
2518 && operand_equal_p (TREE_OPERAND (arg0, 2),
2519 TREE_OPERAND (arg1, 2), flags));
2525 switch (TREE_CODE (arg0))
2528 case TRUTH_NOT_EXPR:
2529 return operand_equal_p (TREE_OPERAND (arg0, 0),
2530 TREE_OPERAND (arg1, 0), flags);
2532 case TRUTH_ANDIF_EXPR:
2533 case TRUTH_ORIF_EXPR:
2534 return operand_equal_p (TREE_OPERAND (arg0, 0),
2535 TREE_OPERAND (arg1, 0), flags)
2536 && operand_equal_p (TREE_OPERAND (arg0, 1),
2537 TREE_OPERAND (arg1, 1), flags);
2539 case TRUTH_AND_EXPR:
2541 case TRUTH_XOR_EXPR:
2542 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2543 TREE_OPERAND (arg1, 0), flags)
2544 && operand_equal_p (TREE_OPERAND (arg0, 1),
2545 TREE_OPERAND (arg1, 1), flags))
2546 || (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. */
2554 if (! operand_equal_p (TREE_OPERAND (arg0, 0),
2555 TREE_OPERAND (arg1, 0), flags))
2559 unsigned int cef = call_expr_flags (arg0);
2560 if (flags & OEP_PURE_SAME)
2561 cef &= ECF_CONST | ECF_PURE;
2568 /* Now see if all the arguments are the same. operand_equal_p
2569 does not handle TREE_LIST, so we walk the operands here
2570 feeding them to operand_equal_p. */
2571 arg0 = TREE_OPERAND (arg0, 1);
2572 arg1 = TREE_OPERAND (arg1, 1);
2573 while (arg0 && arg1)
2575 if (! operand_equal_p (TREE_VALUE (arg0), TREE_VALUE (arg1),
2579 arg0 = TREE_CHAIN (arg0);
2580 arg1 = TREE_CHAIN (arg1);
2583 /* If we get here and both argument lists are exhausted
2584 then the CALL_EXPRs are equal. */
2585 return ! (arg0 || arg1);
2592 /* Consider __builtin_sqrt equal to sqrt. */
2593 return (TREE_CODE (arg0) == FUNCTION_DECL
2594 && DECL_BUILT_IN (arg0) && DECL_BUILT_IN (arg1)
2595 && DECL_BUILT_IN_CLASS (arg0) == DECL_BUILT_IN_CLASS (arg1)
2596 && DECL_FUNCTION_CODE (arg0) == DECL_FUNCTION_CODE (arg1));
2603 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2604 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2606 When in doubt, return 0. */
2609 operand_equal_for_comparison_p (tree arg0, tree arg1, tree other)
2611 int unsignedp1, unsignedpo;
2612 tree primarg0, primarg1, primother;
2613 unsigned int correct_width;
2615 if (operand_equal_p (arg0, arg1, 0))
2618 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
2619 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
2622 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2623 and see if the inner values are the same. This removes any
2624 signedness comparison, which doesn't matter here. */
2625 primarg0 = arg0, primarg1 = arg1;
2626 STRIP_NOPS (primarg0);
2627 STRIP_NOPS (primarg1);
2628 if (operand_equal_p (primarg0, primarg1, 0))
2631 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2632 actual comparison operand, ARG0.
2634 First throw away any conversions to wider types
2635 already present in the operands. */
2637 primarg1 = get_narrower (arg1, &unsignedp1);
2638 primother = get_narrower (other, &unsignedpo);
2640 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
2641 if (unsignedp1 == unsignedpo
2642 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
2643 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
2645 tree type = TREE_TYPE (arg0);
2647 /* Make sure shorter operand is extended the right way
2648 to match the longer operand. */
2649 primarg1 = fold_convert (lang_hooks.types.signed_or_unsigned_type
2650 (unsignedp1, TREE_TYPE (primarg1)), primarg1);
2652 if (operand_equal_p (arg0, fold_convert (type, primarg1), 0))
2659 /* See if ARG is an expression that is either a comparison or is performing
2660 arithmetic on comparisons. The comparisons must only be comparing
2661 two different values, which will be stored in *CVAL1 and *CVAL2; if
2662 they are nonzero it means that some operands have already been found.
2663 No variables may be used anywhere else in the expression except in the
2664 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2665 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2667 If this is true, return 1. Otherwise, return zero. */
2670 twoval_comparison_p (tree arg, tree *cval1, tree *cval2, int *save_p)
2672 enum tree_code code = TREE_CODE (arg);
2673 char class = TREE_CODE_CLASS (code);
2675 /* We can handle some of the 'e' cases here. */
2676 if (class == 'e' && code == TRUTH_NOT_EXPR)
2678 else if (class == 'e'
2679 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
2680 || code == COMPOUND_EXPR))
2683 else if (class == 'e' && code == SAVE_EXPR
2684 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
2686 /* If we've already found a CVAL1 or CVAL2, this expression is
2687 two complex to handle. */
2688 if (*cval1 || *cval2)
2698 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
2701 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
2702 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2703 cval1, cval2, save_p));
2709 if (code == COND_EXPR)
2710 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
2711 cval1, cval2, save_p)
2712 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2713 cval1, cval2, save_p)
2714 && twoval_comparison_p (TREE_OPERAND (arg, 2),
2715 cval1, cval2, save_p));
2719 /* First see if we can handle the first operand, then the second. For
2720 the second operand, we know *CVAL1 can't be zero. It must be that
2721 one side of the comparison is each of the values; test for the
2722 case where this isn't true by failing if the two operands
2725 if (operand_equal_p (TREE_OPERAND (arg, 0),
2726 TREE_OPERAND (arg, 1), 0))
2730 *cval1 = TREE_OPERAND (arg, 0);
2731 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
2733 else if (*cval2 == 0)
2734 *cval2 = TREE_OPERAND (arg, 0);
2735 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
2740 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
2742 else if (*cval2 == 0)
2743 *cval2 = TREE_OPERAND (arg, 1);
2744 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
2756 /* ARG is a tree that is known to contain just arithmetic operations and
2757 comparisons. Evaluate the operations in the tree substituting NEW0 for
2758 any occurrence of OLD0 as an operand of a comparison and likewise for
2762 eval_subst (tree arg, tree old0, tree new0, tree old1, tree new1)
2764 tree type = TREE_TYPE (arg);
2765 enum tree_code code = TREE_CODE (arg);
2766 char class = TREE_CODE_CLASS (code);
2768 /* We can handle some of the 'e' cases here. */
2769 if (class == 'e' && code == TRUTH_NOT_EXPR)
2771 else if (class == 'e'
2772 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2778 return fold (build1 (code, type,
2779 eval_subst (TREE_OPERAND (arg, 0),
2780 old0, new0, old1, new1)));
2783 return fold (build2 (code, type,
2784 eval_subst (TREE_OPERAND (arg, 0),
2785 old0, new0, old1, new1),
2786 eval_subst (TREE_OPERAND (arg, 1),
2787 old0, new0, old1, new1)));
2793 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
2796 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
2799 return fold (build3 (code, type,
2800 eval_subst (TREE_OPERAND (arg, 0),
2801 old0, new0, old1, new1),
2802 eval_subst (TREE_OPERAND (arg, 1),
2803 old0, new0, old1, new1),
2804 eval_subst (TREE_OPERAND (arg, 2),
2805 old0, new0, old1, new1)));
2809 /* Fall through - ??? */
2813 tree arg0 = TREE_OPERAND (arg, 0);
2814 tree arg1 = TREE_OPERAND (arg, 1);
2816 /* We need to check both for exact equality and tree equality. The
2817 former will be true if the operand has a side-effect. In that
2818 case, we know the operand occurred exactly once. */
2820 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
2822 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
2825 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
2827 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
2830 return fold (build2 (code, type, arg0, arg1));
2838 /* Return a tree for the case when the result of an expression is RESULT
2839 converted to TYPE and OMITTED was previously an operand of the expression
2840 but is now not needed (e.g., we folded OMITTED * 0).
2842 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2843 the conversion of RESULT to TYPE. */
2846 omit_one_operand (tree type, tree result, tree omitted)
2848 tree t = fold_convert (type, result);
2850 if (TREE_SIDE_EFFECTS (omitted))
2851 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
2853 return non_lvalue (t);
2856 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2859 pedantic_omit_one_operand (tree type, tree result, tree omitted)
2861 tree t = fold_convert (type, result);
2863 if (TREE_SIDE_EFFECTS (omitted))
2864 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
2866 return pedantic_non_lvalue (t);
2869 /* Return a tree for the case when the result of an expression is RESULT
2870 converted to TYPE and OMITTED1 and OMITTED2 were previously operands
2871 of the expression but are now not needed.
2873 If OMITTED1 or OMITTED2 has side effects, they must be evaluated.
2874 If both OMITTED1 and OMITTED2 have side effects, OMITTED1 is
2875 evaluated before OMITTED2. Otherwise, if neither has side effects,
2876 just do the conversion of RESULT to TYPE. */
2879 omit_two_operands (tree type, tree result, tree omitted1, tree omitted2)
2881 tree t = fold_convert (type, result);
2883 if (TREE_SIDE_EFFECTS (omitted2))
2884 t = build2 (COMPOUND_EXPR, type, omitted2, t);
2885 if (TREE_SIDE_EFFECTS (omitted1))
2886 t = build2 (COMPOUND_EXPR, type, omitted1, t);
2888 return TREE_CODE (t) != COMPOUND_EXPR ? non_lvalue (t) : t;
2892 /* Return a simplified tree node for the truth-negation of ARG. This
2893 never alters ARG itself. We assume that ARG is an operation that
2894 returns a truth value (0 or 1).
2896 FIXME: one would think we would fold the result, but it causes
2897 problems with the dominator optimizer. */
2899 invert_truthvalue (tree arg)
2901 tree type = TREE_TYPE (arg);
2902 enum tree_code code = TREE_CODE (arg);
2904 if (code == ERROR_MARK)
2907 /* If this is a comparison, we can simply invert it, except for
2908 floating-point non-equality comparisons, in which case we just
2909 enclose a TRUTH_NOT_EXPR around what we have. */
2911 if (TREE_CODE_CLASS (code) == '<')
2913 tree op_type = TREE_TYPE (TREE_OPERAND (arg, 0));
2914 if (FLOAT_TYPE_P (op_type)
2915 && flag_trapping_math
2916 && code != ORDERED_EXPR && code != UNORDERED_EXPR
2917 && code != NE_EXPR && code != EQ_EXPR)
2918 return build1 (TRUTH_NOT_EXPR, type, arg);
2921 code = invert_tree_comparison (code,
2922 HONOR_NANS (TYPE_MODE (op_type)));
2923 if (code == ERROR_MARK)
2924 return build1 (TRUTH_NOT_EXPR, type, arg);
2926 return build2 (code, type,
2927 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
2934 return fold_convert (type, build_int_2 (integer_zerop (arg), 0));
2936 case TRUTH_AND_EXPR:
2937 return build2 (TRUTH_OR_EXPR, type,
2938 invert_truthvalue (TREE_OPERAND (arg, 0)),
2939 invert_truthvalue (TREE_OPERAND (arg, 1)));
2942 return build2 (TRUTH_AND_EXPR, type,
2943 invert_truthvalue (TREE_OPERAND (arg, 0)),
2944 invert_truthvalue (TREE_OPERAND (arg, 1)));
2946 case TRUTH_XOR_EXPR:
2947 /* Here we can invert either operand. We invert the first operand
2948 unless the second operand is a TRUTH_NOT_EXPR in which case our
2949 result is the XOR of the first operand with the inside of the
2950 negation of the second operand. */
2952 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
2953 return build2 (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
2954 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
2956 return build2 (TRUTH_XOR_EXPR, type,
2957 invert_truthvalue (TREE_OPERAND (arg, 0)),
2958 TREE_OPERAND (arg, 1));
2960 case TRUTH_ANDIF_EXPR:
2961 return build2 (TRUTH_ORIF_EXPR, type,
2962 invert_truthvalue (TREE_OPERAND (arg, 0)),
2963 invert_truthvalue (TREE_OPERAND (arg, 1)));
2965 case TRUTH_ORIF_EXPR:
2966 return build2 (TRUTH_ANDIF_EXPR, type,
2967 invert_truthvalue (TREE_OPERAND (arg, 0)),
2968 invert_truthvalue (TREE_OPERAND (arg, 1)));
2970 case TRUTH_NOT_EXPR:
2971 return TREE_OPERAND (arg, 0);
2974 return build3 (COND_EXPR, type, TREE_OPERAND (arg, 0),
2975 invert_truthvalue (TREE_OPERAND (arg, 1)),
2976 invert_truthvalue (TREE_OPERAND (arg, 2)));
2979 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
2980 invert_truthvalue (TREE_OPERAND (arg, 1)));
2982 case NON_LVALUE_EXPR:
2983 return invert_truthvalue (TREE_OPERAND (arg, 0));
2986 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE)
2991 return build1 (TREE_CODE (arg), type,
2992 invert_truthvalue (TREE_OPERAND (arg, 0)));
2995 if (!integer_onep (TREE_OPERAND (arg, 1)))
2997 return build2 (EQ_EXPR, type, arg,
2998 fold_convert (type, integer_zero_node));
3001 return build1 (TRUTH_NOT_EXPR, type, arg);
3003 case CLEANUP_POINT_EXPR:
3004 return build1 (CLEANUP_POINT_EXPR, type,
3005 invert_truthvalue (TREE_OPERAND (arg, 0)));
3010 if (TREE_CODE (TREE_TYPE (arg)) != BOOLEAN_TYPE)
3012 return build1 (TRUTH_NOT_EXPR, type, arg);
3015 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
3016 operands are another bit-wise operation with a common input. If so,
3017 distribute the bit operations to save an operation and possibly two if
3018 constants are involved. For example, convert
3019 (A | B) & (A | C) into A | (B & C)
3020 Further simplification will occur if B and C are constants.
3022 If this optimization cannot be done, 0 will be returned. */
3025 distribute_bit_expr (enum tree_code code, tree type, tree arg0, tree arg1)
3030 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3031 || TREE_CODE (arg0) == code
3032 || (TREE_CODE (arg0) != BIT_AND_EXPR
3033 && TREE_CODE (arg0) != BIT_IOR_EXPR))
3036 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
3038 common = TREE_OPERAND (arg0, 0);
3039 left = TREE_OPERAND (arg0, 1);
3040 right = TREE_OPERAND (arg1, 1);
3042 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
3044 common = TREE_OPERAND (arg0, 0);
3045 left = TREE_OPERAND (arg0, 1);
3046 right = TREE_OPERAND (arg1, 0);
3048 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
3050 common = TREE_OPERAND (arg0, 1);
3051 left = TREE_OPERAND (arg0, 0);
3052 right = TREE_OPERAND (arg1, 1);
3054 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
3056 common = TREE_OPERAND (arg0, 1);
3057 left = TREE_OPERAND (arg0, 0);
3058 right = TREE_OPERAND (arg1, 0);
3063 return fold (build2 (TREE_CODE (arg0), type, common,
3064 fold (build2 (code, type, left, right))));
3067 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
3068 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
3071 make_bit_field_ref (tree inner, tree type, int bitsize, int bitpos,
3074 tree result = build3 (BIT_FIELD_REF, type, inner,
3075 size_int (bitsize), bitsize_int (bitpos));
3077 BIT_FIELD_REF_UNSIGNED (result) = unsignedp;
3082 /* Optimize a bit-field compare.
3084 There are two cases: First is a compare against a constant and the
3085 second is a comparison of two items where the fields are at the same
3086 bit position relative to the start of a chunk (byte, halfword, word)
3087 large enough to contain it. In these cases we can avoid the shift
3088 implicit in bitfield extractions.
3090 For constants, we emit a compare of the shifted constant with the
3091 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
3092 compared. For two fields at the same position, we do the ANDs with the
3093 similar mask and compare the result of the ANDs.
3095 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
3096 COMPARE_TYPE is the type of the comparison, and LHS and RHS
3097 are the left and right operands of the comparison, respectively.
3099 If the optimization described above can be done, we return the resulting
3100 tree. Otherwise we return zero. */
3103 optimize_bit_field_compare (enum tree_code code, tree compare_type,
3106 HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
3107 tree type = TREE_TYPE (lhs);
3108 tree signed_type, unsigned_type;
3109 int const_p = TREE_CODE (rhs) == INTEGER_CST;
3110 enum machine_mode lmode, rmode, nmode;
3111 int lunsignedp, runsignedp;
3112 int lvolatilep = 0, rvolatilep = 0;
3113 tree linner, rinner = NULL_TREE;
3117 /* Get all the information about the extractions being done. If the bit size
3118 if the same as the size of the underlying object, we aren't doing an
3119 extraction at all and so can do nothing. We also don't want to
3120 do anything if the inner expression is a PLACEHOLDER_EXPR since we
3121 then will no longer be able to replace it. */
3122 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
3123 &lunsignedp, &lvolatilep);
3124 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
3125 || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
3130 /* If this is not a constant, we can only do something if bit positions,
3131 sizes, and signedness are the same. */
3132 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
3133 &runsignedp, &rvolatilep);
3135 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
3136 || lunsignedp != runsignedp || offset != 0
3137 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
3141 /* See if we can find a mode to refer to this field. We should be able to,
3142 but fail if we can't. */
3143 nmode = get_best_mode (lbitsize, lbitpos,
3144 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
3145 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
3146 TYPE_ALIGN (TREE_TYPE (rinner))),
3147 word_mode, lvolatilep || rvolatilep);
3148 if (nmode == VOIDmode)
3151 /* Set signed and unsigned types of the precision of this mode for the
3153 signed_type = lang_hooks.types.type_for_mode (nmode, 0);
3154 unsigned_type = lang_hooks.types.type_for_mode (nmode, 1);
3156 /* Compute the bit position and size for the new reference and our offset
3157 within it. If the new reference is the same size as the original, we
3158 won't optimize anything, so return zero. */
3159 nbitsize = GET_MODE_BITSIZE (nmode);
3160 nbitpos = lbitpos & ~ (nbitsize - 1);
3162 if (nbitsize == lbitsize)
3165 if (BYTES_BIG_ENDIAN)
3166 lbitpos = nbitsize - lbitsize - lbitpos;
3168 /* Make the mask to be used against the extracted field. */
3169 mask = build_int_2 (~0, ~0);
3170 TREE_TYPE (mask) = unsigned_type;
3171 force_fit_type (mask, 0);
3172 mask = fold_convert (unsigned_type, mask);
3173 mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
3174 mask = const_binop (RSHIFT_EXPR, mask,
3175 size_int (nbitsize - lbitsize - lbitpos), 0);
3178 /* If not comparing with constant, just rework the comparison
3180 return build2 (code, compare_type,
3181 build2 (BIT_AND_EXPR, unsigned_type,
3182 make_bit_field_ref (linner, unsigned_type,
3183 nbitsize, nbitpos, 1),
3185 build2 (BIT_AND_EXPR, unsigned_type,
3186 make_bit_field_ref (rinner, unsigned_type,
3187 nbitsize, nbitpos, 1),
3190 /* Otherwise, we are handling the constant case. See if the constant is too
3191 big for the field. Warn and return a tree of for 0 (false) if so. We do
3192 this not only for its own sake, but to avoid having to test for this
3193 error case below. If we didn't, we might generate wrong code.
3195 For unsigned fields, the constant shifted right by the field length should
3196 be all zero. For signed fields, the high-order bits should agree with
3201 if (! integer_zerop (const_binop (RSHIFT_EXPR,
3202 fold_convert (unsigned_type, rhs),
3203 size_int (lbitsize), 0)))
3205 warning ("comparison is always %d due to width of bit-field",
3207 return constant_boolean_node (code == NE_EXPR, compare_type);
3212 tree tem = const_binop (RSHIFT_EXPR, fold_convert (signed_type, rhs),
3213 size_int (lbitsize - 1), 0);
3214 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
3216 warning ("comparison is always %d due to width of bit-field",
3218 return constant_boolean_node (code == NE_EXPR, compare_type);
3222 /* Single-bit compares should always be against zero. */
3223 if (lbitsize == 1 && ! integer_zerop (rhs))
3225 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
3226 rhs = fold_convert (type, integer_zero_node);
3229 /* Make a new bitfield reference, shift the constant over the
3230 appropriate number of bits and mask it with the computed mask
3231 (in case this was a signed field). If we changed it, make a new one. */
3232 lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1);
3235 TREE_SIDE_EFFECTS (lhs) = 1;
3236 TREE_THIS_VOLATILE (lhs) = 1;
3239 rhs = fold (const_binop (BIT_AND_EXPR,
3240 const_binop (LSHIFT_EXPR,
3241 fold_convert (unsigned_type, rhs),
3242 size_int (lbitpos), 0),
3245 return build2 (code, compare_type,
3246 build2 (BIT_AND_EXPR, unsigned_type, lhs, mask),
3250 /* Subroutine for fold_truthop: decode a field reference.
3252 If EXP is a comparison reference, we return the innermost reference.
3254 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
3255 set to the starting bit number.
3257 If the innermost field can be completely contained in a mode-sized
3258 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
3260 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
3261 otherwise it is not changed.
3263 *PUNSIGNEDP is set to the signedness of the field.
3265 *PMASK is set to the mask used. This is either contained in a
3266 BIT_AND_EXPR or derived from the width of the field.
3268 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
3270 Return 0 if this is not a component reference or is one that we can't
3271 do anything with. */
3274 decode_field_reference (tree exp, HOST_WIDE_INT *pbitsize,
3275 HOST_WIDE_INT *pbitpos, enum machine_mode *pmode,
3276 int *punsignedp, int *pvolatilep,
3277 tree *pmask, tree *pand_mask)
3279 tree outer_type = 0;
3281 tree mask, inner, offset;
3283 unsigned int precision;
3285 /* All the optimizations using this function assume integer fields.
3286 There are problems with FP fields since the type_for_size call
3287 below can fail for, e.g., XFmode. */
3288 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
3291 /* We are interested in the bare arrangement of bits, so strip everything
3292 that doesn't affect the machine mode. However, record the type of the
3293 outermost expression if it may matter below. */
3294 if (TREE_CODE (exp) == NOP_EXPR
3295 || TREE_CODE (exp) == CONVERT_EXPR
3296 || TREE_CODE (exp) == NON_LVALUE_EXPR)
3297 outer_type = TREE_TYPE (exp);
3300 if (TREE_CODE (exp) == BIT_AND_EXPR)
3302 and_mask = TREE_OPERAND (exp, 1);
3303 exp = TREE_OPERAND (exp, 0);
3304 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
3305 if (TREE_CODE (and_mask) != INTEGER_CST)
3309 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
3310 punsignedp, pvolatilep);
3311 if ((inner == exp && and_mask == 0)
3312 || *pbitsize < 0 || offset != 0
3313 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
3316 /* If the number of bits in the reference is the same as the bitsize of
3317 the outer type, then the outer type gives the signedness. Otherwise
3318 (in case of a small bitfield) the signedness is unchanged. */
3319 if (outer_type && *pbitsize == TYPE_PRECISION (outer_type))
3320 *punsignedp = TYPE_UNSIGNED (outer_type);
3322 /* Compute the mask to access the bitfield. */
3323 unsigned_type = lang_hooks.types.type_for_size (*pbitsize, 1);
3324 precision = TYPE_PRECISION (unsigned_type);
3326 mask = build_int_2 (~0, ~0);
3327 TREE_TYPE (mask) = unsigned_type;
3328 force_fit_type (mask, 0);
3329 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3330 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3332 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
3334 mask = fold (build2 (BIT_AND_EXPR, unsigned_type,
3335 fold_convert (unsigned_type, and_mask), mask));
3338 *pand_mask = and_mask;
3342 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
3346 all_ones_mask_p (tree mask, int size)
3348 tree type = TREE_TYPE (mask);
3349 unsigned int precision = TYPE_PRECISION (type);
3352 tmask = build_int_2 (~0, ~0);
3353 TREE_TYPE (tmask) = lang_hooks.types.signed_type (type);
3354 force_fit_type (tmask, 0);
3356 tree_int_cst_equal (mask,
3357 const_binop (RSHIFT_EXPR,
3358 const_binop (LSHIFT_EXPR, tmask,
3359 size_int (precision - size),
3361 size_int (precision - size), 0));
3364 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
3365 represents the sign bit of EXP's type. If EXP represents a sign
3366 or zero extension, also test VAL against the unextended type.
3367 The return value is the (sub)expression whose sign bit is VAL,
3368 or NULL_TREE otherwise. */
3371 sign_bit_p (tree exp, tree val)
3373 unsigned HOST_WIDE_INT mask_lo, lo;
3374 HOST_WIDE_INT mask_hi, hi;
3378 /* Tree EXP must have an integral type. */
3379 t = TREE_TYPE (exp);
3380 if (! INTEGRAL_TYPE_P (t))
3383 /* Tree VAL must be an integer constant. */
3384 if (TREE_CODE (val) != INTEGER_CST
3385 || TREE_CONSTANT_OVERFLOW (val))
3388 width = TYPE_PRECISION (t);
3389 if (width > HOST_BITS_PER_WIDE_INT)
3391 hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1);
3394 mask_hi = ((unsigned HOST_WIDE_INT) -1
3395 >> (2 * HOST_BITS_PER_WIDE_INT - width));
3401 lo = (unsigned HOST_WIDE_INT) 1 << (width - 1);
3404 mask_lo = ((unsigned HOST_WIDE_INT) -1
3405 >> (HOST_BITS_PER_WIDE_INT - width));
3408 /* We mask off those bits beyond TREE_TYPE (exp) so that we can
3409 treat VAL as if it were unsigned. */
3410 if ((TREE_INT_CST_HIGH (val) & mask_hi) == hi
3411 && (TREE_INT_CST_LOW (val) & mask_lo) == lo)
3414 /* Handle extension from a narrower type. */
3415 if (TREE_CODE (exp) == NOP_EXPR
3416 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width)
3417 return sign_bit_p (TREE_OPERAND (exp, 0), val);
3422 /* Subroutine for fold_truthop: determine if an operand is simple enough
3423 to be evaluated unconditionally. */
3426 simple_operand_p (tree exp)
3428 /* Strip any conversions that don't change the machine mode. */
3429 while ((TREE_CODE (exp) == NOP_EXPR
3430 || TREE_CODE (exp) == CONVERT_EXPR)
3431 && (TYPE_MODE (TREE_TYPE (exp))
3432 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)))))
3433 exp = TREE_OPERAND (exp, 0);
3435 return (TREE_CODE_CLASS (TREE_CODE (exp)) == 'c'
3437 && ! TREE_ADDRESSABLE (exp)
3438 && ! TREE_THIS_VOLATILE (exp)
3439 && ! DECL_NONLOCAL (exp)
3440 /* Don't regard global variables as simple. They may be
3441 allocated in ways unknown to the compiler (shared memory,
3442 #pragma weak, etc). */
3443 && ! TREE_PUBLIC (exp)
3444 && ! DECL_EXTERNAL (exp)
3445 /* Loading a static variable is unduly expensive, but global
3446 registers aren't expensive. */
3447 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
3450 /* The following functions are subroutines to fold_range_test and allow it to
3451 try to change a logical combination of comparisons into a range test.
3454 X == 2 || X == 3 || X == 4 || X == 5
3458 (unsigned) (X - 2) <= 3
3460 We describe each set of comparisons as being either inside or outside
3461 a range, using a variable named like IN_P, and then describe the
3462 range with a lower and upper bound. If one of the bounds is omitted,
3463 it represents either the highest or lowest value of the type.
3465 In the comments below, we represent a range by two numbers in brackets
3466 preceded by a "+" to designate being inside that range, or a "-" to
3467 designate being outside that range, so the condition can be inverted by
3468 flipping the prefix. An omitted bound is represented by a "-". For
3469 example, "- [-, 10]" means being outside the range starting at the lowest
3470 possible value and ending at 10, in other words, being greater than 10.
3471 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
3474 We set up things so that the missing bounds are handled in a consistent
3475 manner so neither a missing bound nor "true" and "false" need to be
3476 handled using a special case. */
3478 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
3479 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
3480 and UPPER1_P are nonzero if the respective argument is an upper bound
3481 and zero for a lower. TYPE, if nonzero, is the type of the result; it
3482 must be specified for a comparison. ARG1 will be converted to ARG0's
3483 type if both are specified. */
3486 range_binop (enum tree_code code, tree type, tree arg0, int upper0_p,
3487 tree arg1, int upper1_p)
3493 /* If neither arg represents infinity, do the normal operation.
3494 Else, if not a comparison, return infinity. Else handle the special
3495 comparison rules. Note that most of the cases below won't occur, but
3496 are handled for consistency. */
3498 if (arg0 != 0 && arg1 != 0)
3500 tem = fold (build2 (code, type != 0 ? type : TREE_TYPE (arg0),
3501 arg0, fold_convert (TREE_TYPE (arg0), arg1)));
3503 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
3506 if (TREE_CODE_CLASS (code) != '<')
3509 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
3510 for neither. In real maths, we cannot assume open ended ranges are
3511 the same. But, this is computer arithmetic, where numbers are finite.
3512 We can therefore make the transformation of any unbounded range with
3513 the value Z, Z being greater than any representable number. This permits
3514 us to treat unbounded ranges as equal. */
3515 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
3516 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
3520 result = sgn0 == sgn1;
3523 result = sgn0 != sgn1;
3526 result = sgn0 < sgn1;
3529 result = sgn0 <= sgn1;
3532 result = sgn0 > sgn1;
3535 result = sgn0 >= sgn1;
3541 return constant_boolean_node (result, type);
3544 /* Given EXP, a logical expression, set the range it is testing into
3545 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
3546 actually being tested. *PLOW and *PHIGH will be made of the same type
3547 as the returned expression. If EXP is not a comparison, we will most
3548 likely not be returning a useful value and range. */
3551 make_range (tree exp, int *pin_p, tree *plow, tree *phigh)
3553 enum tree_code code;
3554 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
3555 tree exp_type = NULL_TREE, arg0_type = NULL_TREE;
3557 tree low, high, n_low, n_high;
3559 /* Start with simply saying "EXP != 0" and then look at the code of EXP
3560 and see if we can refine the range. Some of the cases below may not
3561 happen, but it doesn't seem worth worrying about this. We "continue"
3562 the outer loop when we've changed something; otherwise we "break"
3563 the switch, which will "break" the while. */
3566 low = high = fold_convert (TREE_TYPE (exp), integer_zero_node);
3570 code = TREE_CODE (exp);
3571 exp_type = TREE_TYPE (exp);
3573 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
3575 if (first_rtl_op (code) > 0)
3576 arg0 = TREE_OPERAND (exp, 0);
3577 if (TREE_CODE_CLASS (code) == '<'
3578 || TREE_CODE_CLASS (code) == '1'
3579 || TREE_CODE_CLASS (code) == '2')
3580 arg0_type = TREE_TYPE (arg0);
3581 if (TREE_CODE_CLASS (code) == '2'
3582 || TREE_CODE_CLASS (code) == '<'
3583 || (TREE_CODE_CLASS (code) == 'e'
3584 && TREE_CODE_LENGTH (code) > 1))
3585 arg1 = TREE_OPERAND (exp, 1);
3590 case TRUTH_NOT_EXPR:
3591 in_p = ! in_p, exp = arg0;
3594 case EQ_EXPR: case NE_EXPR:
3595 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
3596 /* We can only do something if the range is testing for zero
3597 and if the second operand is an integer constant. Note that
3598 saying something is "in" the range we make is done by
3599 complementing IN_P since it will set in the initial case of
3600 being not equal to zero; "out" is leaving it alone. */
3601 if (low == 0 || high == 0
3602 || ! integer_zerop (low) || ! integer_zerop (high)
3603 || TREE_CODE (arg1) != INTEGER_CST)
3608 case NE_EXPR: /* - [c, c] */
3611 case EQ_EXPR: /* + [c, c] */
3612 in_p = ! in_p, low = high = arg1;
3614 case GT_EXPR: /* - [-, c] */
3615 low = 0, high = arg1;
3617 case GE_EXPR: /* + [c, -] */
3618 in_p = ! in_p, low = arg1, high = 0;
3620 case LT_EXPR: /* - [c, -] */
3621 low = arg1, high = 0;
3623 case LE_EXPR: /* + [-, c] */
3624 in_p = ! in_p, low = 0, high = arg1;
3630 /* If this is an unsigned comparison, we also know that EXP is
3631 greater than or equal to zero. We base the range tests we make
3632 on that fact, so we record it here so we can parse existing
3633 range tests. We test arg0_type since often the return type
3634 of, e.g. EQ_EXPR, is boolean. */
3635 if (TYPE_UNSIGNED (arg0_type) && (low == 0 || high == 0))
3637 if (! merge_ranges (&n_in_p, &n_low, &n_high, in_p, low, high,
3638 1, fold_convert (arg0_type, integer_zero_node),
3642 in_p = n_in_p, low = n_low, high = n_high;
3644 /* If the high bound is missing, but we have a nonzero low
3645 bound, reverse the range so it goes from zero to the low bound
3647 if (high == 0 && low && ! integer_zerop (low))
3650 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
3651 integer_one_node, 0);
3652 low = fold_convert (arg0_type, integer_zero_node);
3660 /* (-x) IN [a,b] -> x in [-b, -a] */
3661 n_low = range_binop (MINUS_EXPR, exp_type,
3662 fold_convert (exp_type, integer_zero_node),
3664 n_high = range_binop (MINUS_EXPR, exp_type,
3665 fold_convert (exp_type, integer_zero_node),
3667 low = n_low, high = n_high;
3673 exp = build2 (MINUS_EXPR, exp_type, negate_expr (arg0),
3674 fold_convert (exp_type, integer_one_node));
3677 case PLUS_EXPR: case MINUS_EXPR:
3678 if (TREE_CODE (arg1) != INTEGER_CST)
3681 /* If EXP is signed, any overflow in the computation is undefined,
3682 so we don't worry about it so long as our computations on
3683 the bounds don't overflow. For unsigned, overflow is defined
3684 and this is exactly the right thing. */
3685 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3686 arg0_type, low, 0, arg1, 0);
3687 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3688 arg0_type, high, 1, arg1, 0);
3689 if ((n_low != 0 && TREE_OVERFLOW (n_low))
3690 || (n_high != 0 && TREE_OVERFLOW (n_high)))
3693 /* Check for an unsigned range which has wrapped around the maximum
3694 value thus making n_high < n_low, and normalize it. */
3695 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
3697 low = range_binop (PLUS_EXPR, arg0_type, n_high, 0,
3698 integer_one_node, 0);
3699 high = range_binop (MINUS_EXPR, arg0_type, n_low, 0,
3700 integer_one_node, 0);
3702 /* If the range is of the form +/- [ x+1, x ], we won't
3703 be able to normalize it. But then, it represents the
3704 whole range or the empty set, so make it
3706 if (tree_int_cst_equal (n_low, low)
3707 && tree_int_cst_equal (n_high, high))
3713 low = n_low, high = n_high;
3718 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
3719 if (TYPE_PRECISION (arg0_type) > TYPE_PRECISION (exp_type))
3722 if (! INTEGRAL_TYPE_P (arg0_type)
3723 || (low != 0 && ! int_fits_type_p (low, arg0_type))
3724 || (high != 0 && ! int_fits_type_p (high, arg0_type)))
3727 n_low = low, n_high = high;
3730 n_low = fold_convert (arg0_type, n_low);
3733 n_high = fold_convert (arg0_type, n_high);
3736 /* If we're converting arg0 from an unsigned type, to exp,
3737 a signed type, we will be doing the comparison as unsigned.
3738 The tests above have already verified that LOW and HIGH
3741 So we have to ensure that we will handle large unsigned
3742 values the same way that the current signed bounds treat
3745 if (!TYPE_UNSIGNED (exp_type) && TYPE_UNSIGNED (arg0_type))
3748 tree equiv_type = lang_hooks.types.type_for_mode
3749 (TYPE_MODE (arg0_type), 1);
3751 /* A range without an upper bound is, naturally, unbounded.
3752 Since convert would have cropped a very large value, use
3753 the max value for the destination type. */
3755 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
3756 : TYPE_MAX_VALUE (arg0_type);
3758 if (TYPE_PRECISION (exp_type) == TYPE_PRECISION (arg0_type))
3759 high_positive = fold (build2 (RSHIFT_EXPR, arg0_type,
3760 fold_convert (arg0_type,
3762 fold_convert (arg0_type,
3763 integer_one_node)));
3765 /* If the low bound is specified, "and" the range with the
3766 range for which the original unsigned value will be
3770 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3771 1, n_low, n_high, 1,
3772 fold_convert (arg0_type, integer_zero_node),
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, integer_zero_node),
3788 in_p = (in_p != n_in_p);
3793 low = n_low, high = n_high;
3803 /* If EXP is a constant, we can evaluate whether this is true or false. */
3804 if (TREE_CODE (exp) == INTEGER_CST)
3806 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
3808 && integer_onep (range_binop (LE_EXPR, integer_type_node,
3814 *pin_p = in_p, *plow = low, *phigh = high;
3818 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3819 type, TYPE, return an expression to test if EXP is in (or out of, depending
3820 on IN_P) the range. Return 0 if the test couldn't be created. */
3823 build_range_check (tree type, tree exp, int in_p, tree low, tree high)
3825 tree etype = TREE_TYPE (exp);
3830 value = build_range_check (type, exp, 1, low, high);
3832 return invert_truthvalue (value);
3837 if (low == 0 && high == 0)
3838 return fold_convert (type, integer_one_node);
3841 return fold (build2 (LE_EXPR, type, exp, high));
3844 return fold (build2 (GE_EXPR, type, exp, low));
3846 if (operand_equal_p (low, high, 0))
3847 return fold (build2 (EQ_EXPR, type, exp, low));
3849 if (integer_zerop (low))
3851 if (! TYPE_UNSIGNED (etype))
3853 etype = lang_hooks.types.unsigned_type (etype);
3854 high = fold_convert (etype, high);
3855 exp = fold_convert (etype, exp);
3857 return build_range_check (type, exp, 1, 0, high);
3860 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
3861 if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST)
3863 unsigned HOST_WIDE_INT lo;
3867 prec = TYPE_PRECISION (etype);
3868 if (prec <= HOST_BITS_PER_WIDE_INT)
3871 lo = ((unsigned HOST_WIDE_INT) 1 << (prec - 1)) - 1;
3875 hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1;
3876 lo = (unsigned HOST_WIDE_INT) -1;
3879 if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo)
3881 if (TYPE_UNSIGNED (etype))
3883 etype = lang_hooks.types.signed_type (etype);
3884 exp = fold_convert (etype, exp);
3886 return fold (build2 (GT_EXPR, type, exp,
3887 fold_convert (etype, integer_zero_node)));
3891 value = const_binop (MINUS_EXPR, high, low, 0);
3892 if (value != 0 && TREE_OVERFLOW (value) && ! TYPE_UNSIGNED (etype))
3894 tree utype, minv, maxv;
3896 /* Check if (unsigned) INT_MAX + 1 == (unsigned) INT_MIN
3897 for the type in question, as we rely on this here. */
3898 switch (TREE_CODE (etype))
3903 utype = lang_hooks.types.unsigned_type (etype);
3904 maxv = fold_convert (utype, TYPE_MAX_VALUE (etype));
3905 maxv = range_binop (PLUS_EXPR, NULL_TREE, maxv, 1,
3906 integer_one_node, 1);
3907 minv = fold_convert (utype, TYPE_MIN_VALUE (etype));
3908 if (integer_zerop (range_binop (NE_EXPR, integer_type_node,
3912 high = fold_convert (etype, high);
3913 low = fold_convert (etype, low);
3914 exp = fold_convert (etype, exp);
3915 value = const_binop (MINUS_EXPR, high, low, 0);
3923 if (value != 0 && ! TREE_OVERFLOW (value))
3924 return build_range_check (type,
3925 fold (build2 (MINUS_EXPR, etype, exp, low)),
3926 1, fold_convert (etype, integer_zero_node),
3932 /* Given two ranges, see if we can merge them into one. Return 1 if we
3933 can, 0 if we can't. Set the output range into the specified parameters. */
3936 merge_ranges (int *pin_p, tree *plow, tree *phigh, int in0_p, tree low0,
3937 tree high0, int in1_p, tree low1, tree high1)
3945 int lowequal = ((low0 == 0 && low1 == 0)
3946 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3947 low0, 0, low1, 0)));
3948 int highequal = ((high0 == 0 && high1 == 0)
3949 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3950 high0, 1, high1, 1)));
3952 /* Make range 0 be the range that starts first, or ends last if they
3953 start at the same value. Swap them if it isn't. */
3954 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
3957 && integer_onep (range_binop (GT_EXPR, integer_type_node,
3958 high1, 1, high0, 1))))
3960 temp = in0_p, in0_p = in1_p, in1_p = temp;
3961 tem = low0, low0 = low1, low1 = tem;
3962 tem = high0, high0 = high1, high1 = tem;
3965 /* Now flag two cases, whether the ranges are disjoint or whether the
3966 second range is totally subsumed in the first. Note that the tests
3967 below are simplified by the ones above. */
3968 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
3969 high0, 1, low1, 0));
3970 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
3971 high1, 1, high0, 1));
3973 /* We now have four cases, depending on whether we are including or
3974 excluding the two ranges. */
3977 /* If they don't overlap, the result is false. If the second range
3978 is a subset it is the result. Otherwise, the range is from the start
3979 of the second to the end of the first. */
3981 in_p = 0, low = high = 0;
3983 in_p = 1, low = low1, high = high1;
3985 in_p = 1, low = low1, high = high0;
3988 else if (in0_p && ! in1_p)
3990 /* If they don't overlap, the result is the first range. If they are
3991 equal, the result is false. If the second range is a subset of the
3992 first, and the ranges begin at the same place, we go from just after
3993 the end of the first range to the end of the second. If the second
3994 range is not a subset of the first, or if it is a subset and both
3995 ranges end at the same place, the range starts at the start of the
3996 first range and ends just before the second range.
3997 Otherwise, we can't describe this as a single range. */
3999 in_p = 1, low = low0, high = high0;
4000 else if (lowequal && highequal)
4001 in_p = 0, low = high = 0;
4002 else if (subset && lowequal)
4004 in_p = 1, high = high0;
4005 low = range_binop (PLUS_EXPR, NULL_TREE, high1, 0,
4006 integer_one_node, 0);
4008 else if (! subset || highequal)
4010 in_p = 1, low = low0;
4011 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
4012 integer_one_node, 0);
4018 else if (! in0_p && in1_p)
4020 /* If they don't overlap, the result is the second range. If the second
4021 is a subset of the first, the result is false. Otherwise,
4022 the range starts just after the first range and ends at the
4023 end of the second. */
4025 in_p = 1, low = low1, high = high1;
4026 else if (subset || highequal)
4027 in_p = 0, low = high = 0;
4030 in_p = 1, high = high1;
4031 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
4032 integer_one_node, 0);
4038 /* The case where we are excluding both ranges. Here the complex case
4039 is if they don't overlap. In that case, the only time we have a
4040 range is if they are adjacent. If the second is a subset of the
4041 first, the result is the first. Otherwise, the range to exclude
4042 starts at the beginning of the first range and ends at the end of the
4046 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
4047 range_binop (PLUS_EXPR, NULL_TREE,
4049 integer_one_node, 1),
4051 in_p = 0, low = low0, high = high1;
4054 /* Canonicalize - [min, x] into - [-, x]. */
4055 if (low0 && TREE_CODE (low0) == INTEGER_CST)
4056 switch (TREE_CODE (TREE_TYPE (low0)))
4059 if (TYPE_PRECISION (TREE_TYPE (low0))
4060 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (low0))))
4065 if (tree_int_cst_equal (low0,
4066 TYPE_MIN_VALUE (TREE_TYPE (low0))))
4070 if (TYPE_UNSIGNED (TREE_TYPE (low0))
4071 && integer_zerop (low0))
4078 /* Canonicalize - [x, max] into - [x, -]. */
4079 if (high1 && TREE_CODE (high1) == INTEGER_CST)
4080 switch (TREE_CODE (TREE_TYPE (high1)))
4083 if (TYPE_PRECISION (TREE_TYPE (high1))
4084 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (high1))))
4089 if (tree_int_cst_equal (high1,
4090 TYPE_MAX_VALUE (TREE_TYPE (high1))))
4094 if (TYPE_UNSIGNED (TREE_TYPE (high1))
4095 && integer_zerop (range_binop (PLUS_EXPR, NULL_TREE,
4097 integer_one_node, 1)))
4104 /* The ranges might be also adjacent between the maximum and
4105 minimum values of the given type. For
4106 - [{min,-}, x] and - [y, {max,-}] ranges where x + 1 < y
4107 return + [x + 1, y - 1]. */
4108 if (low0 == 0 && high1 == 0)
4110 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
4111 integer_one_node, 1);
4112 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
4113 integer_one_node, 0);
4114 if (low == 0 || high == 0)
4124 in_p = 0, low = low0, high = high0;
4126 in_p = 0, low = low0, high = high1;
4129 *pin_p = in_p, *plow = low, *phigh = high;
4134 /* Subroutine of fold, looking inside expressions of the form
4135 A op B ? A : C, where ARG0, ARG1 and ARG2 are the three operands
4136 of the COND_EXPR. This function is being used also to optimize
4137 A op B ? C : A, by reversing the comparison first.
4139 Return a folded expression whose code is not a COND_EXPR
4140 anymore, or NULL_TREE if no folding opportunity is found. */
4143 fold_cond_expr_with_comparison (tree type, tree arg0, tree arg1, tree arg2)
4145 enum tree_code comp_code = TREE_CODE (arg0);
4146 tree arg00 = TREE_OPERAND (arg0, 0);
4147 tree arg01 = TREE_OPERAND (arg0, 1);
4148 tree arg1_type = TREE_TYPE (arg1);
4154 /* If we have A op 0 ? A : -A, consider applying the following
4157 A == 0? A : -A same as -A
4158 A != 0? A : -A same as A
4159 A >= 0? A : -A same as abs (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)
4164 None of these transformations work for modes with signed
4165 zeros. If A is +/-0, the first two transformations will
4166 change the sign of the result (from +0 to -0, or vice
4167 versa). The last four will fix the sign of the result,
4168 even though the original expressions could be positive or
4169 negative, depending on the sign of A.
4171 Note that all these transformations are correct if A is
4172 NaN, since the two alternatives (A and -A) are also NaNs. */
4173 if ((FLOAT_TYPE_P (TREE_TYPE (arg01))
4174 ? real_zerop (arg01)
4175 : integer_zerop (arg01))
4176 && TREE_CODE (arg2) == NEGATE_EXPR
4177 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
4181 tem = fold_convert (arg1_type, arg1);
4182 return pedantic_non_lvalue (fold_convert (type, negate_expr (tem)));
4184 return pedantic_non_lvalue (fold_convert (type, arg1));
4187 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
4188 arg1 = fold_convert (lang_hooks.types.signed_type
4189 (TREE_TYPE (arg1)), arg1);
4190 tem = fold (build1 (ABS_EXPR, TREE_TYPE (arg1), arg1));
4191 return pedantic_non_lvalue (fold_convert (type, tem));
4194 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
4195 arg1 = fold_convert (lang_hooks.types.signed_type
4196 (TREE_TYPE (arg1)), arg1);
4197 tem = fold (build1 (ABS_EXPR, TREE_TYPE (arg1), arg1));
4198 return negate_expr (fold_convert (type, tem));
4203 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
4204 A == 0 ? A : 0 is always 0 unless A is -0. Note that
4205 both transformations are correct when A is NaN: A != 0
4206 is then true, and A == 0 is false. */
4208 if (integer_zerop (arg01) && integer_zerop (arg2))
4210 if (comp_code == NE_EXPR)
4211 return pedantic_non_lvalue (fold_convert (type, arg1));
4212 else if (comp_code == EQ_EXPR)
4213 return pedantic_non_lvalue (fold_convert (type, integer_zero_node));
4216 /* Try some transformations of A op B ? A : B.
4218 A == B? A : B same as B
4219 A != B? A : B same as A
4220 A >= B? A : B same as max (A, B)
4221 A > B? A : B same as max (B, A)
4222 A <= B? A : B same as min (A, B)
4223 A < B? A : B same as min (B, A)
4225 As above, these transformations don't work in the presence
4226 of signed zeros. For example, if A and B are zeros of
4227 opposite sign, the first two transformations will change
4228 the sign of the result. In the last four, the original
4229 expressions give different results for (A=+0, B=-0) and
4230 (A=-0, B=+0), but the transformed expressions do not.
4232 The first two transformations are correct if either A or B
4233 is a NaN. In the first transformation, the condition will
4234 be false, and B will indeed be chosen. In the case of the
4235 second transformation, the condition A != B will be true,
4236 and A will be chosen.
4238 The conversions to max() and min() are not correct if B is
4239 a number and A is not. The conditions in the original
4240 expressions will be false, so all four give B. The min()
4241 and max() versions would give a NaN instead. */
4242 if (operand_equal_for_comparison_p (arg01, arg2, arg00))
4244 tree comp_op0 = arg00;
4245 tree comp_op1 = arg01;
4246 tree comp_type = TREE_TYPE (comp_op0);
4248 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
4249 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
4259 return pedantic_non_lvalue (fold_convert (type, arg2));
4261 return pedantic_non_lvalue (fold_convert (type, arg1));
4264 /* In C++ a ?: expression can be an lvalue, so put the
4265 operand which will be used if they are equal first
4266 so that we can convert this back to the
4267 corresponding COND_EXPR. */
4268 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4269 return pedantic_non_lvalue (
4270 fold_convert (type, fold (build2 (MIN_EXPR, comp_type,
4271 (comp_code == LE_EXPR
4272 ? comp_op0 : comp_op1),
4273 (comp_code == LE_EXPR
4274 ? comp_op1 : comp_op0)))));
4278 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4279 return pedantic_non_lvalue (
4280 fold_convert (type, fold (build2 (MAX_EXPR, comp_type,
4281 (comp_code == GE_EXPR
4282 ? comp_op0 : comp_op1),
4283 (comp_code == GE_EXPR
4284 ? comp_op1 : comp_op0)))));
4291 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
4292 we might still be able to simplify this. For example,
4293 if C1 is one less or one more than C2, this might have started
4294 out as a MIN or MAX and been transformed by this function.
4295 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
4297 if (INTEGRAL_TYPE_P (type)
4298 && TREE_CODE (arg01) == INTEGER_CST
4299 && TREE_CODE (arg2) == INTEGER_CST)
4303 /* We can replace A with C1 in this case. */
4304 arg1 = fold_convert (type, arg01);
4305 return fold (build3 (COND_EXPR, type, arg0, arg1, arg2));
4308 /* If C1 is C2 + 1, this is min(A, C2). */
4309 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
4311 && operand_equal_p (arg01,
4312 const_binop (PLUS_EXPR, arg2,
4313 integer_one_node, 0),
4315 return pedantic_non_lvalue (fold (build2 (MIN_EXPR,
4316 type, arg1, arg2)));
4320 /* If C1 is C2 - 1, this is min(A, C2). */
4321 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
4323 && operand_equal_p (arg01,
4324 const_binop (MINUS_EXPR, arg2,
4325 integer_one_node, 0),
4327 return pedantic_non_lvalue (fold (build2 (MIN_EXPR,
4328 type, arg1, arg2)));
4332 /* If C1 is C2 - 1, this is max(A, C2). */
4333 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
4335 && operand_equal_p (arg01,
4336 const_binop (MINUS_EXPR, arg2,
4337 integer_one_node, 0),
4339 return pedantic_non_lvalue (fold (build2 (MAX_EXPR,
4340 type, arg1, arg2)));
4344 /* If C1 is C2 + 1, this is max(A, C2). */
4345 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
4347 && operand_equal_p (arg01,
4348 const_binop (PLUS_EXPR, arg2,
4349 integer_one_node, 0),
4351 return pedantic_non_lvalue (fold (build2 (MAX_EXPR,
4352 type, arg1, arg2)));
4365 #ifndef RANGE_TEST_NON_SHORT_CIRCUIT
4366 #define RANGE_TEST_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
4369 /* EXP is some logical combination of boolean tests. See if we can
4370 merge it into some range test. Return the new tree if so. */
4373 fold_range_test (tree exp)
4375 int or_op = (TREE_CODE (exp) == TRUTH_ORIF_EXPR
4376 || TREE_CODE (exp) == TRUTH_OR_EXPR);
4377 int in0_p, in1_p, in_p;
4378 tree low0, low1, low, high0, high1, high;
4379 tree lhs = make_range (TREE_OPERAND (exp, 0), &in0_p, &low0, &high0);
4380 tree rhs = make_range (TREE_OPERAND (exp, 1), &in1_p, &low1, &high1);
4383 /* If this is an OR operation, invert both sides; we will invert
4384 again at the end. */
4386 in0_p = ! in0_p, in1_p = ! in1_p;
4388 /* If both expressions are the same, if we can merge the ranges, and we
4389 can build the range test, return it or it inverted. If one of the
4390 ranges is always true or always false, consider it to be the same
4391 expression as the other. */
4392 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
4393 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
4395 && 0 != (tem = (build_range_check (TREE_TYPE (exp),
4397 : rhs != 0 ? rhs : integer_zero_node,
4399 return or_op ? invert_truthvalue (tem) : tem;
4401 /* On machines where the branch cost is expensive, if this is a
4402 short-circuited branch and the underlying object on both sides
4403 is the same, make a non-short-circuit operation. */
4404 else if (RANGE_TEST_NON_SHORT_CIRCUIT
4405 && lhs != 0 && rhs != 0
4406 && (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
4407 || TREE_CODE (exp) == TRUTH_ORIF_EXPR)
4408 && operand_equal_p (lhs, rhs, 0))
4410 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
4411 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
4412 which cases we can't do this. */
4413 if (simple_operand_p (lhs))
4414 return build2 (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
4415 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
4416 TREE_TYPE (exp), TREE_OPERAND (exp, 0),
4417 TREE_OPERAND (exp, 1));
4419 else if (lang_hooks.decls.global_bindings_p () == 0
4420 && ! CONTAINS_PLACEHOLDER_P (lhs))
4422 tree common = save_expr (lhs);
4424 if (0 != (lhs = build_range_check (TREE_TYPE (exp), common,
4425 or_op ? ! in0_p : in0_p,
4427 && (0 != (rhs = build_range_check (TREE_TYPE (exp), common,
4428 or_op ? ! in1_p : in1_p,
4430 return build2 (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
4431 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
4432 TREE_TYPE (exp), lhs, rhs);
4439 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
4440 bit value. Arrange things so the extra bits will be set to zero if and
4441 only if C is signed-extended to its full width. If MASK is nonzero,
4442 it is an INTEGER_CST that should be AND'ed with the extra bits. */
4445 unextend (tree c, int p, int unsignedp, tree mask)
4447 tree type = TREE_TYPE (c);
4448 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
4451 if (p == modesize || unsignedp)
4454 /* We work by getting just the sign bit into the low-order bit, then
4455 into the high-order bit, then sign-extend. We then XOR that value
4457 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
4458 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
4460 /* We must use a signed type in order to get an arithmetic right shift.
4461 However, we must also avoid introducing accidental overflows, so that
4462 a subsequent call to integer_zerop will work. Hence we must
4463 do the type conversion here. At this point, the constant is either
4464 zero or one, and the conversion to a signed type can never overflow.
4465 We could get an overflow if this conversion is done anywhere else. */
4466 if (TYPE_UNSIGNED (type))
4467 temp = fold_convert (lang_hooks.types.signed_type (type), temp);
4469 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
4470 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
4472 temp = const_binop (BIT_AND_EXPR, temp,
4473 fold_convert (TREE_TYPE (c), mask), 0);
4474 /* If necessary, convert the type back to match the type of C. */
4475 if (TYPE_UNSIGNED (type))
4476 temp = fold_convert (type, temp);
4478 return fold_convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
4481 /* Find ways of folding logical expressions of LHS and RHS:
4482 Try to merge two comparisons to the same innermost item.
4483 Look for range tests like "ch >= '0' && ch <= '9'".
4484 Look for combinations of simple terms on machines with expensive branches
4485 and evaluate the RHS unconditionally.
4487 For example, if we have p->a == 2 && p->b == 4 and we can make an
4488 object large enough to span both A and B, we can do this with a comparison
4489 against the object ANDed with the a mask.
4491 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
4492 operations to do this with one comparison.
4494 We check for both normal comparisons and the BIT_AND_EXPRs made this by
4495 function and the one above.
4497 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
4498 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
4500 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
4503 We return the simplified tree or 0 if no optimization is possible. */
4506 fold_truthop (enum tree_code code, tree truth_type, tree lhs, tree rhs)
4508 /* If this is the "or" of two comparisons, we can do something if
4509 the comparisons are NE_EXPR. If this is the "and", we can do something
4510 if the comparisons are EQ_EXPR. I.e.,
4511 (a->b == 2 && a->c == 4) can become (a->new == NEW).
4513 WANTED_CODE is this operation code. For single bit fields, we can
4514 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
4515 comparison for one-bit fields. */
4517 enum tree_code wanted_code;
4518 enum tree_code lcode, rcode;
4519 tree ll_arg, lr_arg, rl_arg, rr_arg;
4520 tree ll_inner, lr_inner, rl_inner, rr_inner;
4521 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
4522 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
4523 HOST_WIDE_INT xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
4524 HOST_WIDE_INT lnbitsize, lnbitpos, rnbitsize, rnbitpos;
4525 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
4526 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
4527 enum machine_mode lnmode, rnmode;
4528 tree ll_mask, lr_mask, rl_mask, rr_mask;
4529 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
4530 tree l_const, r_const;
4531 tree lntype, rntype, result;
4532 int first_bit, end_bit;
4535 /* Start by getting the comparison codes. Fail if anything is volatile.
4536 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
4537 it were surrounded with a NE_EXPR. */
4539 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
4542 lcode = TREE_CODE (lhs);
4543 rcode = TREE_CODE (rhs);
4545 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
4547 lhs = build2 (NE_EXPR, truth_type, lhs, integer_zero_node);
4551 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
4553 rhs = build2 (NE_EXPR, truth_type, rhs, integer_zero_node);
4557 if (TREE_CODE_CLASS (lcode) != '<' || TREE_CODE_CLASS (rcode) != '<')
4560 ll_arg = TREE_OPERAND (lhs, 0);
4561 lr_arg = TREE_OPERAND (lhs, 1);
4562 rl_arg = TREE_OPERAND (rhs, 0);
4563 rr_arg = TREE_OPERAND (rhs, 1);
4565 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
4566 if (simple_operand_p (ll_arg)
4567 && simple_operand_p (lr_arg))
4570 if (operand_equal_p (ll_arg, rl_arg, 0)
4571 && operand_equal_p (lr_arg, rr_arg, 0))
4573 result = combine_comparisons (code, lcode, rcode,
4574 truth_type, ll_arg, lr_arg);
4578 else if (operand_equal_p (ll_arg, rr_arg, 0)
4579 && operand_equal_p (lr_arg, rl_arg, 0))
4581 result = combine_comparisons (code, lcode,
4582 swap_tree_comparison (rcode),
4583 truth_type, ll_arg, lr_arg);
4589 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
4590 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
4592 /* If the RHS can be evaluated unconditionally and its operands are
4593 simple, it wins to evaluate the RHS unconditionally on machines
4594 with expensive branches. In this case, this isn't a comparison
4595 that can be merged. Avoid doing this if the RHS is a floating-point
4596 comparison since those can trap. */
4598 if (BRANCH_COST >= 2
4599 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
4600 && simple_operand_p (rl_arg)
4601 && simple_operand_p (rr_arg))
4603 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
4604 if (code == TRUTH_OR_EXPR
4605 && lcode == NE_EXPR && integer_zerop (lr_arg)
4606 && rcode == NE_EXPR && integer_zerop (rr_arg)
4607 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
4608 return build2 (NE_EXPR, truth_type,
4609 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
4611 fold_convert (TREE_TYPE (ll_arg), integer_zero_node));
4613 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
4614 if (code == TRUTH_AND_EXPR
4615 && lcode == EQ_EXPR && integer_zerop (lr_arg)
4616 && rcode == EQ_EXPR && integer_zerop (rr_arg)
4617 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
4618 return build2 (EQ_EXPR, truth_type,
4619 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
4621 fold_convert (TREE_TYPE (ll_arg), integer_zero_node));
4623 return build2 (code, truth_type, lhs, rhs);
4626 /* See if the comparisons can be merged. Then get all the parameters for
4629 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
4630 || (rcode != EQ_EXPR && rcode != NE_EXPR))
4634 ll_inner = decode_field_reference (ll_arg,
4635 &ll_bitsize, &ll_bitpos, &ll_mode,
4636 &ll_unsignedp, &volatilep, &ll_mask,
4638 lr_inner = decode_field_reference (lr_arg,
4639 &lr_bitsize, &lr_bitpos, &lr_mode,
4640 &lr_unsignedp, &volatilep, &lr_mask,
4642 rl_inner = decode_field_reference (rl_arg,
4643 &rl_bitsize, &rl_bitpos, &rl_mode,
4644 &rl_unsignedp, &volatilep, &rl_mask,
4646 rr_inner = decode_field_reference (rr_arg,
4647 &rr_bitsize, &rr_bitpos, &rr_mode,
4648 &rr_unsignedp, &volatilep, &rr_mask,
4651 /* It must be true that the inner operation on the lhs of each
4652 comparison must be the same if we are to be able to do anything.
4653 Then see if we have constants. If not, the same must be true for
4655 if (volatilep || ll_inner == 0 || rl_inner == 0
4656 || ! operand_equal_p (ll_inner, rl_inner, 0))
4659 if (TREE_CODE (lr_arg) == INTEGER_CST
4660 && TREE_CODE (rr_arg) == INTEGER_CST)
4661 l_const = lr_arg, r_const = rr_arg;
4662 else if (lr_inner == 0 || rr_inner == 0
4663 || ! operand_equal_p (lr_inner, rr_inner, 0))
4666 l_const = r_const = 0;
4668 /* If either comparison code is not correct for our logical operation,
4669 fail. However, we can convert a one-bit comparison against zero into
4670 the opposite comparison against that bit being set in the field. */
4672 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
4673 if (lcode != wanted_code)
4675 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
4677 /* Make the left operand unsigned, since we are only interested
4678 in the value of one bit. Otherwise we are doing the wrong
4687 /* This is analogous to the code for l_const above. */
4688 if (rcode != wanted_code)
4690 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
4699 /* After this point all optimizations will generate bit-field
4700 references, which we might not want. */
4701 if (! lang_hooks.can_use_bit_fields_p ())
4704 /* See if we can find a mode that contains both fields being compared on
4705 the left. If we can't, fail. Otherwise, update all constants and masks
4706 to be relative to a field of that size. */
4707 first_bit = MIN (ll_bitpos, rl_bitpos);
4708 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
4709 lnmode = get_best_mode (end_bit - first_bit, first_bit,
4710 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
4712 if (lnmode == VOIDmode)
4715 lnbitsize = GET_MODE_BITSIZE (lnmode);
4716 lnbitpos = first_bit & ~ (lnbitsize - 1);
4717 lntype = lang_hooks.types.type_for_size (lnbitsize, 1);
4718 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
4720 if (BYTES_BIG_ENDIAN)
4722 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
4723 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
4726 ll_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, ll_mask),
4727 size_int (xll_bitpos), 0);
4728 rl_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, rl_mask),
4729 size_int (xrl_bitpos), 0);
4733 l_const = fold_convert (lntype, l_const);
4734 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
4735 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
4736 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
4737 fold (build1 (BIT_NOT_EXPR,
4741 warning ("comparison is always %d", wanted_code == NE_EXPR);
4743 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
4748 r_const = fold_convert (lntype, r_const);
4749 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
4750 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
4751 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
4752 fold (build1 (BIT_NOT_EXPR,
4756 warning ("comparison is always %d", wanted_code == NE_EXPR);
4758 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
4762 /* If the right sides are not constant, do the same for it. Also,
4763 disallow this optimization if a size or signedness mismatch occurs
4764 between the left and right sides. */
4767 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
4768 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
4769 /* Make sure the two fields on the right
4770 correspond to the left without being swapped. */
4771 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
4774 first_bit = MIN (lr_bitpos, rr_bitpos);
4775 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
4776 rnmode = get_best_mode (end_bit - first_bit, first_bit,
4777 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
4779 if (rnmode == VOIDmode)
4782 rnbitsize = GET_MODE_BITSIZE (rnmode);
4783 rnbitpos = first_bit & ~ (rnbitsize - 1);
4784 rntype = lang_hooks.types.type_for_size (rnbitsize, 1);
4785 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
4787 if (BYTES_BIG_ENDIAN)
4789 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
4790 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
4793 lr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, lr_mask),
4794 size_int (xlr_bitpos), 0);
4795 rr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, rr_mask),
4796 size_int (xrr_bitpos), 0);
4798 /* Make a mask that corresponds to both fields being compared.
4799 Do this for both items being compared. If the operands are the
4800 same size and the bits being compared are in the same position
4801 then we can do this by masking both and comparing the masked
4803 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4804 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
4805 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
4807 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4808 ll_unsignedp || rl_unsignedp);
4809 if (! all_ones_mask_p (ll_mask, lnbitsize))
4810 lhs = build2 (BIT_AND_EXPR, lntype, lhs, ll_mask);
4812 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
4813 lr_unsignedp || rr_unsignedp);
4814 if (! all_ones_mask_p (lr_mask, rnbitsize))
4815 rhs = build2 (BIT_AND_EXPR, rntype, rhs, lr_mask);
4817 return build2 (wanted_code, truth_type, lhs, rhs);
4820 /* There is still another way we can do something: If both pairs of
4821 fields being compared are adjacent, we may be able to make a wider
4822 field containing them both.
4824 Note that we still must mask the lhs/rhs expressions. Furthermore,
4825 the mask must be shifted to account for the shift done by
4826 make_bit_field_ref. */
4827 if ((ll_bitsize + ll_bitpos == rl_bitpos
4828 && lr_bitsize + lr_bitpos == rr_bitpos)
4829 || (ll_bitpos == rl_bitpos + rl_bitsize
4830 && lr_bitpos == rr_bitpos + rr_bitsize))
4834 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
4835 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
4836 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
4837 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
4839 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
4840 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
4841 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
4842 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
4844 /* Convert to the smaller type before masking out unwanted bits. */
4846 if (lntype != rntype)
4848 if (lnbitsize > rnbitsize)
4850 lhs = fold_convert (rntype, lhs);
4851 ll_mask = fold_convert (rntype, ll_mask);
4854 else if (lnbitsize < rnbitsize)
4856 rhs = fold_convert (lntype, rhs);
4857 lr_mask = fold_convert (lntype, lr_mask);
4862 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
4863 lhs = build2 (BIT_AND_EXPR, type, lhs, ll_mask);
4865 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
4866 rhs = build2 (BIT_AND_EXPR, type, rhs, lr_mask);
4868 return build2 (wanted_code, truth_type, lhs, rhs);
4874 /* Handle the case of comparisons with constants. If there is something in
4875 common between the masks, those bits of the constants must be the same.
4876 If not, the condition is always false. Test for this to avoid generating
4877 incorrect code below. */
4878 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
4879 if (! integer_zerop (result)
4880 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
4881 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
4883 if (wanted_code == NE_EXPR)
4885 warning ("`or' of unmatched not-equal tests is always 1");
4886 return constant_boolean_node (true, truth_type);
4890 warning ("`and' of mutually exclusive equal-tests is always 0");
4891 return constant_boolean_node (false, truth_type);
4895 /* Construct the expression we will return. First get the component
4896 reference we will make. Unless the mask is all ones the width of
4897 that field, perform the mask operation. Then compare with the
4899 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4900 ll_unsignedp || rl_unsignedp);
4902 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4903 if (! all_ones_mask_p (ll_mask, lnbitsize))
4904 result = build2 (BIT_AND_EXPR, lntype, result, ll_mask);
4906 return build2 (wanted_code, truth_type, result,
4907 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
4910 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
4914 optimize_minmax_comparison (tree t)
4916 tree type = TREE_TYPE (t);
4917 tree arg0 = TREE_OPERAND (t, 0);
4918 enum tree_code op_code;
4919 tree comp_const = TREE_OPERAND (t, 1);
4921 int consts_equal, consts_lt;
4924 STRIP_SIGN_NOPS (arg0);
4926 op_code = TREE_CODE (arg0);
4927 minmax_const = TREE_OPERAND (arg0, 1);
4928 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
4929 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
4930 inner = TREE_OPERAND (arg0, 0);
4932 /* If something does not permit us to optimize, return the original tree. */
4933 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
4934 || TREE_CODE (comp_const) != INTEGER_CST
4935 || TREE_CONSTANT_OVERFLOW (comp_const)
4936 || TREE_CODE (minmax_const) != INTEGER_CST
4937 || TREE_CONSTANT_OVERFLOW (minmax_const))
4940 /* Now handle all the various comparison codes. We only handle EQ_EXPR
4941 and GT_EXPR, doing the rest with recursive calls using logical
4943 switch (TREE_CODE (t))
4945 case NE_EXPR: case LT_EXPR: case LE_EXPR:
4947 invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t)));
4951 fold (build2 (TRUTH_ORIF_EXPR, type,
4952 optimize_minmax_comparison
4953 (build2 (EQ_EXPR, type, arg0, comp_const)),
4954 optimize_minmax_comparison
4955 (build2 (GT_EXPR, type, arg0, comp_const))));
4958 if (op_code == MAX_EXPR && consts_equal)
4959 /* MAX (X, 0) == 0 -> X <= 0 */
4960 return fold (build2 (LE_EXPR, type, inner, comp_const));
4962 else if (op_code == MAX_EXPR && consts_lt)
4963 /* MAX (X, 0) == 5 -> X == 5 */
4964 return fold (build2 (EQ_EXPR, type, inner, comp_const));
4966 else if (op_code == MAX_EXPR)
4967 /* MAX (X, 0) == -1 -> false */
4968 return omit_one_operand (type, integer_zero_node, inner);
4970 else if (consts_equal)
4971 /* MIN (X, 0) == 0 -> X >= 0 */
4972 return fold (build2 (GE_EXPR, type, inner, comp_const));
4975 /* MIN (X, 0) == 5 -> false */
4976 return omit_one_operand (type, integer_zero_node, inner);
4979 /* MIN (X, 0) == -1 -> X == -1 */
4980 return fold (build2 (EQ_EXPR, type, inner, comp_const));
4983 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
4984 /* MAX (X, 0) > 0 -> X > 0
4985 MAX (X, 0) > 5 -> X > 5 */
4986 return fold (build2 (GT_EXPR, type, inner, comp_const));
4988 else if (op_code == MAX_EXPR)
4989 /* MAX (X, 0) > -1 -> true */
4990 return omit_one_operand (type, integer_one_node, inner);
4992 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
4993 /* MIN (X, 0) > 0 -> false
4994 MIN (X, 0) > 5 -> false */
4995 return omit_one_operand (type, integer_zero_node, inner);
4998 /* MIN (X, 0) > -1 -> X > -1 */
4999 return fold (build2 (GT_EXPR, type, inner, comp_const));
5006 /* T is an integer expression that is being multiplied, divided, or taken a
5007 modulus (CODE says which and what kind of divide or modulus) by a
5008 constant C. See if we can eliminate that operation by folding it with
5009 other operations already in T. WIDE_TYPE, if non-null, is a type that
5010 should be used for the computation if wider than our type.
5012 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
5013 (X * 2) + (Y * 4). We must, however, be assured that either the original
5014 expression would not overflow or that overflow is undefined for the type
5015 in the language in question.
5017 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
5018 the machine has a multiply-accumulate insn or that this is part of an
5019 addressing calculation.
5021 If we return a non-null expression, it is an equivalent form of the
5022 original computation, but need not be in the original type. */
5025 extract_muldiv (tree t, tree c, enum tree_code code, tree wide_type)
5027 /* To avoid exponential search depth, refuse to allow recursion past
5028 three levels. Beyond that (1) it's highly unlikely that we'll find
5029 something interesting and (2) we've probably processed it before
5030 when we built the inner expression. */
5039 ret = extract_muldiv_1 (t, c, code, wide_type);
5046 extract_muldiv_1 (tree t, tree c, enum tree_code code, tree wide_type)
5048 tree type = TREE_TYPE (t);
5049 enum tree_code tcode = TREE_CODE (t);
5050 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
5051 > GET_MODE_SIZE (TYPE_MODE (type)))
5052 ? wide_type : type);
5054 int same_p = tcode == code;
5055 tree op0 = NULL_TREE, op1 = NULL_TREE;
5057 /* Don't deal with constants of zero here; they confuse the code below. */
5058 if (integer_zerop (c))
5061 if (TREE_CODE_CLASS (tcode) == '1')
5062 op0 = TREE_OPERAND (t, 0);
5064 if (TREE_CODE_CLASS (tcode) == '2')
5065 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
5067 /* Note that we need not handle conditional operations here since fold
5068 already handles those cases. So just do arithmetic here. */
5072 /* For a constant, we can always simplify if we are a multiply
5073 or (for divide and modulus) if it is a multiple of our constant. */
5074 if (code == MULT_EXPR
5075 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
5076 return const_binop (code, fold_convert (ctype, t),
5077 fold_convert (ctype, c), 0);
5080 case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
5081 /* If op0 is an expression ... */
5082 if ((TREE_CODE_CLASS (TREE_CODE (op0)) == '<'
5083 || TREE_CODE_CLASS (TREE_CODE (op0)) == '1'
5084 || TREE_CODE_CLASS (TREE_CODE (op0)) == '2'
5085 || TREE_CODE_CLASS (TREE_CODE (op0)) == 'e')
5086 /* ... and is unsigned, and its type is smaller than ctype,
5087 then we cannot pass through as widening. */
5088 && ((TYPE_UNSIGNED (TREE_TYPE (op0))
5089 && ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
5090 && TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
5091 && (GET_MODE_SIZE (TYPE_MODE (ctype))
5092 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
5093 /* ... or its type is larger than ctype,
5094 then we cannot pass through this truncation. */
5095 || (GET_MODE_SIZE (TYPE_MODE (ctype))
5096 < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0))))
5097 /* ... or signedness changes for division or modulus,
5098 then we cannot pass through this conversion. */
5099 || (code != MULT_EXPR
5100 && (TYPE_UNSIGNED (ctype)
5101 != TYPE_UNSIGNED (TREE_TYPE (op0))))))
5104 /* Pass the constant down and see if we can make a simplification. If
5105 we can, replace this expression with the inner simplification for
5106 possible later conversion to our or some other type. */
5107 if ((t2 = fold_convert (TREE_TYPE (op0), c)) != 0
5108 && TREE_CODE (t2) == INTEGER_CST
5109 && ! TREE_CONSTANT_OVERFLOW (t2)
5110 && (0 != (t1 = extract_muldiv (op0, t2, code,
5112 ? ctype : NULL_TREE))))
5116 case NEGATE_EXPR: case ABS_EXPR:
5117 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
5118 return fold (build1 (tcode, ctype, fold_convert (ctype, t1)));
5121 case MIN_EXPR: case MAX_EXPR:
5122 /* If widening the type changes the signedness, then we can't perform
5123 this optimization as that changes the result. */
5124 if (TYPE_UNSIGNED (ctype) != TYPE_UNSIGNED (type))
5127 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
5128 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0
5129 && (t2 = extract_muldiv (op1, c, code, wide_type)) != 0)
5131 if (tree_int_cst_sgn (c) < 0)
5132 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
5134 return fold (build2 (tcode, ctype, fold_convert (ctype, t1),
5135 fold_convert (ctype, t2)));
5139 case LSHIFT_EXPR: case RSHIFT_EXPR:
5140 /* If the second operand is constant, this is a multiplication
5141 or floor division, by a power of two, so we can treat it that
5142 way unless the multiplier or divisor overflows. Signed
5143 left-shift overflow is implementation-defined rather than
5144 undefined in C90, so do not convert signed left shift into
5146 if (TREE_CODE (op1) == INTEGER_CST
5147 && (tcode == RSHIFT_EXPR || TYPE_UNSIGNED (TREE_TYPE (op0)))
5148 /* const_binop may not detect overflow correctly,
5149 so check for it explicitly here. */
5150 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
5151 && TREE_INT_CST_HIGH (op1) == 0
5152 && 0 != (t1 = fold_convert (ctype,
5153 const_binop (LSHIFT_EXPR,
5156 && ! TREE_OVERFLOW (t1))
5157 return extract_muldiv (build2 (tcode == LSHIFT_EXPR
5158 ? MULT_EXPR : FLOOR_DIV_EXPR,
5159 ctype, fold_convert (ctype, op0), t1),
5160 c, code, wide_type);
5163 case PLUS_EXPR: case MINUS_EXPR:
5164 /* See if we can eliminate the operation on both sides. If we can, we
5165 can return a new PLUS or MINUS. If we can't, the only remaining
5166 cases where we can do anything are if the second operand is a
5168 t1 = extract_muldiv (op0, c, code, wide_type);
5169 t2 = extract_muldiv (op1, c, code, wide_type);
5170 if (t1 != 0 && t2 != 0
5171 && (code == MULT_EXPR
5172 /* If not multiplication, we can only do this if both operands
5173 are divisible by c. */
5174 || (multiple_of_p (ctype, op0, c)
5175 && multiple_of_p (ctype, op1, c))))
5176 return fold (build2 (tcode, ctype, fold_convert (ctype, t1),
5177 fold_convert (ctype, t2)));
5179 /* If this was a subtraction, negate OP1 and set it to be an addition.
5180 This simplifies the logic below. */
5181 if (tcode == MINUS_EXPR)
5182 tcode = PLUS_EXPR, op1 = negate_expr (op1);
5184 if (TREE_CODE (op1) != INTEGER_CST)
5187 /* If either OP1 or C are negative, this optimization is not safe for
5188 some of the division and remainder types while for others we need
5189 to change the code. */
5190 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
5192 if (code == CEIL_DIV_EXPR)
5193 code = FLOOR_DIV_EXPR;
5194 else if (code == FLOOR_DIV_EXPR)
5195 code = CEIL_DIV_EXPR;
5196 else if (code != MULT_EXPR
5197 && code != CEIL_MOD_EXPR && code != FLOOR_MOD_EXPR)
5201 /* If it's a multiply or a division/modulus operation of a multiple
5202 of our constant, do the operation and verify it doesn't overflow. */
5203 if (code == MULT_EXPR
5204 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5206 op1 = const_binop (code, fold_convert (ctype, op1),
5207 fold_convert (ctype, c), 0);
5208 /* We allow the constant to overflow with wrapping semantics. */
5210 || (TREE_OVERFLOW (op1) && ! flag_wrapv))
5216 /* If we have an unsigned type is not a sizetype, we cannot widen
5217 the operation since it will change the result if the original
5218 computation overflowed. */
5219 if (TYPE_UNSIGNED (ctype)
5220 && ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
5224 /* If we were able to eliminate our operation from the first side,
5225 apply our operation to the second side and reform the PLUS. */
5226 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
5227 return fold (build2 (tcode, ctype, fold_convert (ctype, t1), op1));
5229 /* The last case is if we are a multiply. In that case, we can
5230 apply the distributive law to commute the multiply and addition
5231 if the multiplication of the constants doesn't overflow. */
5232 if (code == MULT_EXPR)
5233 return fold (build2 (tcode, ctype,
5234 fold (build2 (code, ctype,
5235 fold_convert (ctype, op0),
5236 fold_convert (ctype, c))),
5242 /* We have a special case here if we are doing something like
5243 (C * 8) % 4 since we know that's zero. */
5244 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
5245 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
5246 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
5247 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5248 return omit_one_operand (type, integer_zero_node, op0);
5250 /* ... fall through ... */
5252 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
5253 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
5254 /* If we can extract our operation from the LHS, do so and return a
5255 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
5256 do something only if the second operand is a constant. */
5258 && (t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
5259 return fold (build2 (tcode, ctype, fold_convert (ctype, t1),
5260 fold_convert (ctype, op1)));
5261 else if (tcode == MULT_EXPR && code == MULT_EXPR
5262 && (t1 = extract_muldiv (op1, c, code, wide_type)) != 0)
5263 return fold (build2 (tcode, ctype, fold_convert (ctype, op0),
5264 fold_convert (ctype, t1)));
5265 else if (TREE_CODE (op1) != INTEGER_CST)
5268 /* If these are the same operation types, we can associate them
5269 assuming no overflow. */
5271 && 0 != (t1 = const_binop (MULT_EXPR, fold_convert (ctype, op1),
5272 fold_convert (ctype, c), 0))
5273 && ! TREE_OVERFLOW (t1))
5274 return fold (build2 (tcode, ctype, fold_convert (ctype, op0), t1));
5276 /* If these operations "cancel" each other, we have the main
5277 optimizations of this pass, which occur when either constant is a
5278 multiple of the other, in which case we replace this with either an
5279 operation or CODE or TCODE.
5281 If we have an unsigned type that is not a sizetype, we cannot do
5282 this since it will change the result if the original computation
5284 if ((! TYPE_UNSIGNED (ctype)
5285 || (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
5287 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
5288 || (tcode == MULT_EXPR
5289 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
5290 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR)))
5292 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5293 return fold (build2 (tcode, ctype, fold_convert (ctype, op0),
5294 fold_convert (ctype,
5295 const_binop (TRUNC_DIV_EXPR,
5297 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
5298 return fold (build2 (code, ctype, fold_convert (ctype, op0),
5299 fold_convert (ctype,
5300 const_binop (TRUNC_DIV_EXPR,
5312 /* Return a node which has the indicated constant VALUE (either 0 or
5313 1), and is of the indicated TYPE. */
5316 constant_boolean_node (int value, tree type)
5318 if (type == integer_type_node)
5319 return value ? integer_one_node : integer_zero_node;
5320 else if (type == boolean_type_node)
5321 return value ? boolean_true_node : boolean_false_node;
5322 else if (TREE_CODE (type) == BOOLEAN_TYPE)
5323 return lang_hooks.truthvalue_conversion (value ? integer_one_node
5324 : integer_zero_node);
5327 tree t = build_int_2 (value, 0);
5329 TREE_TYPE (t) = type;
5334 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
5335 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
5336 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
5337 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
5338 COND is the first argument to CODE; otherwise (as in the example
5339 given here), it is the second argument. TYPE is the type of the
5340 original expression. Return NULL_TREE if no simplification is
5344 fold_binary_op_with_conditional_arg (enum tree_code code, tree type,
5345 tree cond, tree arg, int cond_first_p)
5347 tree test, true_value, false_value;
5348 tree lhs = NULL_TREE;
5349 tree rhs = NULL_TREE;
5351 /* This transformation is only worthwhile if we don't have to wrap
5352 arg in a SAVE_EXPR, and the operation can be simplified on atleast
5353 one of the branches once its pushed inside the COND_EXPR. */
5354 if (!TREE_CONSTANT (arg))
5357 if (TREE_CODE (cond) == COND_EXPR)
5359 test = TREE_OPERAND (cond, 0);
5360 true_value = TREE_OPERAND (cond, 1);
5361 false_value = TREE_OPERAND (cond, 2);
5362 /* If this operand throws an expression, then it does not make
5363 sense to try to perform a logical or arithmetic operation
5365 if (VOID_TYPE_P (TREE_TYPE (true_value)))
5367 if (VOID_TYPE_P (TREE_TYPE (false_value)))
5372 tree testtype = TREE_TYPE (cond);
5374 true_value = constant_boolean_node (true, testtype);
5375 false_value = constant_boolean_node (false, testtype);
5379 lhs = fold (cond_first_p ? build2 (code, type, true_value, arg)
5380 : build2 (code, type, arg, true_value));
5382 rhs = fold (cond_first_p ? build2 (code, type, false_value, arg)
5383 : build2 (code, type, arg, false_value));
5385 test = fold (build3 (COND_EXPR, type, test, lhs, rhs));
5386 return fold_convert (type, test);
5390 /* Subroutine of fold() that checks for the addition of +/- 0.0.
5392 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
5393 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
5394 ADDEND is the same as X.
5396 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
5397 and finite. The problematic cases are when X is zero, and its mode
5398 has signed zeros. In the case of rounding towards -infinity,
5399 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
5400 modes, X + 0 is not the same as X because -0 + 0 is 0. */
5403 fold_real_zero_addition_p (tree type, tree addend, int negate)
5405 if (!real_zerop (addend))
5408 /* Don't allow the fold with -fsignaling-nans. */
5409 if (HONOR_SNANS (TYPE_MODE (type)))
5412 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
5413 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
5416 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
5417 if (TREE_CODE (addend) == REAL_CST
5418 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
5421 /* The mode has signed zeros, and we have to honor their sign.
5422 In this situation, there is only one case we can return true for.
5423 X - 0 is the same as X unless rounding towards -infinity is
5425 return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
5428 /* Subroutine of fold() that checks comparisons of built-in math
5429 functions against real constants.
5431 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
5432 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
5433 is the type of the result and ARG0 and ARG1 are the operands of the
5434 comparison. ARG1 must be a TREE_REAL_CST.
5436 The function returns the constant folded tree if a simplification
5437 can be made, and NULL_TREE otherwise. */
5440 fold_mathfn_compare (enum built_in_function fcode, enum tree_code code,
5441 tree type, tree arg0, tree arg1)
5445 if (BUILTIN_SQRT_P (fcode))
5447 tree arg = TREE_VALUE (TREE_OPERAND (arg0, 1));
5448 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg0));
5450 c = TREE_REAL_CST (arg1);
5451 if (REAL_VALUE_NEGATIVE (c))
5453 /* sqrt(x) < y is always false, if y is negative. */
5454 if (code == EQ_EXPR || code == LT_EXPR || code == LE_EXPR)
5455 return omit_one_operand (type, integer_zero_node, arg);
5457 /* sqrt(x) > y is always true, if y is negative and we
5458 don't care about NaNs, i.e. negative values of x. */
5459 if (code == NE_EXPR || !HONOR_NANS (mode))
5460 return omit_one_operand (type, integer_one_node, arg);
5462 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
5463 return fold (build2 (GE_EXPR, type, arg,
5464 build_real (TREE_TYPE (arg), dconst0)));
5466 else if (code == GT_EXPR || code == GE_EXPR)
5470 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
5471 real_convert (&c2, mode, &c2);
5473 if (REAL_VALUE_ISINF (c2))
5475 /* sqrt(x) > y is x == +Inf, when y is very large. */
5476 if (HONOR_INFINITIES (mode))
5477 return fold (build2 (EQ_EXPR, type, arg,
5478 build_real (TREE_TYPE (arg), c2)));
5480 /* sqrt(x) > y is always false, when y is very large
5481 and we don't care about infinities. */
5482 return omit_one_operand (type, integer_zero_node, arg);
5485 /* sqrt(x) > c is the same as x > c*c. */
5486 return fold (build2 (code, type, arg,
5487 build_real (TREE_TYPE (arg), c2)));
5489 else if (code == LT_EXPR || code == LE_EXPR)
5493 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
5494 real_convert (&c2, mode, &c2);
5496 if (REAL_VALUE_ISINF (c2))
5498 /* sqrt(x) < y is always true, when y is a very large
5499 value and we don't care about NaNs or Infinities. */
5500 if (! HONOR_NANS (mode) && ! HONOR_INFINITIES (mode))
5501 return omit_one_operand (type, integer_one_node, arg);
5503 /* sqrt(x) < y is x != +Inf when y is very large and we
5504 don't care about NaNs. */
5505 if (! HONOR_NANS (mode))
5506 return fold (build2 (NE_EXPR, type, arg,
5507 build_real (TREE_TYPE (arg), c2)));
5509 /* sqrt(x) < y is x >= 0 when y is very large and we
5510 don't care about Infinities. */
5511 if (! HONOR_INFINITIES (mode))
5512 return fold (build2 (GE_EXPR, type, arg,
5513 build_real (TREE_TYPE (arg), dconst0)));
5515 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
5516 if (lang_hooks.decls.global_bindings_p () != 0
5517 || CONTAINS_PLACEHOLDER_P (arg))
5520 arg = save_expr (arg);
5521 return fold (build2 (TRUTH_ANDIF_EXPR, type,
5522 fold (build2 (GE_EXPR, type, arg,
5523 build_real (TREE_TYPE (arg),
5525 fold (build2 (NE_EXPR, type, arg,
5526 build_real (TREE_TYPE (arg),
5530 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
5531 if (! HONOR_NANS (mode))
5532 return fold (build2 (code, type, arg,
5533 build_real (TREE_TYPE (arg), c2)));
5535 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
5536 if (lang_hooks.decls.global_bindings_p () == 0
5537 && ! CONTAINS_PLACEHOLDER_P (arg))
5539 arg = save_expr (arg);
5540 return fold (build2 (TRUTH_ANDIF_EXPR, type,
5541 fold (build2 (GE_EXPR, type, arg,
5542 build_real (TREE_TYPE (arg),
5544 fold (build2 (code, type, arg,
5545 build_real (TREE_TYPE (arg),
5554 /* Subroutine of fold() that optimizes comparisons against Infinities,
5555 either +Inf or -Inf.
5557 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
5558 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
5559 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
5561 The function returns the constant folded tree if a simplification
5562 can be made, and NULL_TREE otherwise. */
5565 fold_inf_compare (enum tree_code code, tree type, tree arg0, tree arg1)
5567 enum machine_mode mode;
5568 REAL_VALUE_TYPE max;
5572 mode = TYPE_MODE (TREE_TYPE (arg0));
5574 /* For negative infinity swap the sense of the comparison. */
5575 neg = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1));
5577 code = swap_tree_comparison (code);
5582 /* x > +Inf is always false, if with ignore sNANs. */
5583 if (HONOR_SNANS (mode))
5585 return omit_one_operand (type, integer_zero_node, arg0);
5588 /* x <= +Inf is always true, if we don't case about NaNs. */
5589 if (! HONOR_NANS (mode))
5590 return omit_one_operand (type, integer_one_node, arg0);
5592 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
5593 if (lang_hooks.decls.global_bindings_p () == 0
5594 && ! CONTAINS_PLACEHOLDER_P (arg0))
5596 arg0 = save_expr (arg0);
5597 return fold (build2 (EQ_EXPR, type, arg0, arg0));
5603 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
5604 real_maxval (&max, neg, mode);
5605 return fold (build2 (neg ? LT_EXPR : GT_EXPR, type,
5606 arg0, build_real (TREE_TYPE (arg0), max)));
5609 /* x < +Inf is always equal to x <= DBL_MAX. */
5610 real_maxval (&max, neg, mode);
5611 return fold (build2 (neg ? GE_EXPR : LE_EXPR, type,
5612 arg0, build_real (TREE_TYPE (arg0), max)));
5615 /* x != +Inf is always equal to !(x > DBL_MAX). */
5616 real_maxval (&max, neg, mode);
5617 if (! HONOR_NANS (mode))
5618 return fold (build2 (neg ? GE_EXPR : LE_EXPR, type,
5619 arg0, build_real (TREE_TYPE (arg0), max)));
5621 /* The transformation below creates non-gimple code and thus is
5622 not appropriate if we are in gimple form. */
5626 temp = fold (build2 (neg ? LT_EXPR : GT_EXPR, type,
5627 arg0, build_real (TREE_TYPE (arg0), max)));
5628 return fold (build1 (TRUTH_NOT_EXPR, type, temp));
5637 /* Subroutine of fold() that optimizes comparisons of a division by
5638 a nonzero integer constant against an integer constant, i.e.
5641 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
5642 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
5643 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
5645 The function returns the constant folded tree if a simplification
5646 can be made, and NULL_TREE otherwise. */
5649 fold_div_compare (enum tree_code code, tree type, tree arg0, tree arg1)
5651 tree prod, tmp, hi, lo;
5652 tree arg00 = TREE_OPERAND (arg0, 0);
5653 tree arg01 = TREE_OPERAND (arg0, 1);
5654 unsigned HOST_WIDE_INT lpart;
5655 HOST_WIDE_INT hpart;
5658 /* We have to do this the hard way to detect unsigned overflow.
5659 prod = int_const_binop (MULT_EXPR, arg01, arg1, 0); */
5660 overflow = mul_double (TREE_INT_CST_LOW (arg01),
5661 TREE_INT_CST_HIGH (arg01),
5662 TREE_INT_CST_LOW (arg1),
5663 TREE_INT_CST_HIGH (arg1), &lpart, &hpart);
5664 prod = build_int_2 (lpart, hpart);
5665 TREE_TYPE (prod) = TREE_TYPE (arg00);
5666 TREE_OVERFLOW (prod) = force_fit_type (prod, overflow)
5667 || TREE_INT_CST_HIGH (prod) != hpart
5668 || TREE_INT_CST_LOW (prod) != lpart;
5669 TREE_CONSTANT_OVERFLOW (prod) = TREE_OVERFLOW (prod);
5671 if (TYPE_UNSIGNED (TREE_TYPE (arg0)))
5673 tmp = int_const_binop (MINUS_EXPR, arg01, integer_one_node, 0);
5676 /* Likewise hi = int_const_binop (PLUS_EXPR, prod, tmp, 0). */
5677 overflow = add_double (TREE_INT_CST_LOW (prod),
5678 TREE_INT_CST_HIGH (prod),
5679 TREE_INT_CST_LOW (tmp),
5680 TREE_INT_CST_HIGH (tmp),
5682 hi = build_int_2 (lpart, hpart);
5683 TREE_TYPE (hi) = TREE_TYPE (arg00);
5684 TREE_OVERFLOW (hi) = force_fit_type (hi, overflow)
5685 || TREE_INT_CST_HIGH (hi) != hpart
5686 || TREE_INT_CST_LOW (hi) != lpart
5687 || TREE_OVERFLOW (prod);
5688 TREE_CONSTANT_OVERFLOW (hi) = TREE_OVERFLOW (hi);
5690 else if (tree_int_cst_sgn (arg01) >= 0)
5692 tmp = int_const_binop (MINUS_EXPR, arg01, integer_one_node, 0);
5693 switch (tree_int_cst_sgn (arg1))
5696 lo = int_const_binop (MINUS_EXPR, prod, tmp, 0);
5701 lo = fold_negate_const (tmp, TREE_TYPE (arg0));
5706 hi = int_const_binop (PLUS_EXPR, prod, tmp, 0);
5716 tmp = int_const_binop (PLUS_EXPR, arg01, integer_one_node, 0);
5717 switch (tree_int_cst_sgn (arg1))
5720 hi = int_const_binop (MINUS_EXPR, prod, tmp, 0);
5725 hi = fold_negate_const (tmp, TREE_TYPE (arg0));
5730 lo = int_const_binop (PLUS_EXPR, prod, tmp, 0);
5742 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
5743 return omit_one_operand (type, integer_zero_node, arg00);
5744 if (TREE_OVERFLOW (hi))
5745 return fold (build2 (GE_EXPR, type, arg00, lo));
5746 if (TREE_OVERFLOW (lo))
5747 return fold (build2 (LE_EXPR, type, arg00, hi));
5748 return build_range_check (type, arg00, 1, lo, hi);
5751 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
5752 return omit_one_operand (type, integer_one_node, arg00);
5753 if (TREE_OVERFLOW (hi))
5754 return fold (build2 (LT_EXPR, type, arg00, lo));
5755 if (TREE_OVERFLOW (lo))
5756 return fold (build2 (GT_EXPR, type, arg00, hi));
5757 return build_range_check (type, arg00, 0, lo, hi);
5760 if (TREE_OVERFLOW (lo))
5761 return omit_one_operand (type, integer_zero_node, arg00);
5762 return fold (build2 (LT_EXPR, type, arg00, lo));
5765 if (TREE_OVERFLOW (hi))
5766 return omit_one_operand (type, integer_one_node, arg00);
5767 return fold (build2 (LE_EXPR, type, arg00, hi));
5770 if (TREE_OVERFLOW (hi))
5771 return omit_one_operand (type, integer_zero_node, arg00);
5772 return fold (build2 (GT_EXPR, type, arg00, hi));
5775 if (TREE_OVERFLOW (lo))
5776 return omit_one_operand (type, integer_one_node, arg00);
5777 return fold (build2 (GE_EXPR, type, arg00, lo));
5787 /* If CODE with arguments ARG0 and ARG1 represents a single bit
5788 equality/inequality test, then return a simplified form of
5789 the test using shifts and logical operations. Otherwise return
5790 NULL. TYPE is the desired result type. */
5793 fold_single_bit_test (enum tree_code code, tree arg0, tree arg1,
5796 /* If this is a TRUTH_NOT_EXPR, it may have a single bit test inside
5798 if (code == TRUTH_NOT_EXPR)
5800 code = TREE_CODE (arg0);
5801 if (code != NE_EXPR && code != EQ_EXPR)
5804 /* Extract the arguments of the EQ/NE. */
5805 arg1 = TREE_OPERAND (arg0, 1);
5806 arg0 = TREE_OPERAND (arg0, 0);
5808 /* This requires us to invert the code. */
5809 code = (code == EQ_EXPR ? NE_EXPR : EQ_EXPR);
5812 /* If this is testing a single bit, we can optimize the test. */
5813 if ((code == NE_EXPR || code == EQ_EXPR)
5814 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
5815 && integer_pow2p (TREE_OPERAND (arg0, 1)))
5817 tree inner = TREE_OPERAND (arg0, 0);
5818 tree type = TREE_TYPE (arg0);
5819 int bitnum = tree_log2 (TREE_OPERAND (arg0, 1));
5820 enum machine_mode operand_mode = TYPE_MODE (type);
5822 tree signed_type, unsigned_type, intermediate_type;
5825 /* If we have (A & C) != 0 where C is the sign bit of A, convert
5826 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
5827 arg00 = sign_bit_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
5828 if (arg00 != NULL_TREE
5829 /* This is only a win if casting to a signed type is cheap,
5830 i.e. when arg00's type is not a partial mode. */
5831 && TYPE_PRECISION (TREE_TYPE (arg00))
5832 == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg00))))
5834 tree stype = lang_hooks.types.signed_type (TREE_TYPE (arg00));
5835 return fold (build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
5836 result_type, fold_convert (stype, arg00),
5837 fold_convert (stype, integer_zero_node)));
5840 /* Otherwise we have (A & C) != 0 where C is a single bit,
5841 convert that into ((A >> C2) & 1). Where C2 = log2(C).
5842 Similarly for (A & C) == 0. */
5844 /* If INNER is a right shift of a constant and it plus BITNUM does
5845 not overflow, adjust BITNUM and INNER. */
5846 if (TREE_CODE (inner) == RSHIFT_EXPR
5847 && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST
5848 && TREE_INT_CST_HIGH (TREE_OPERAND (inner, 1)) == 0
5849 && bitnum < TYPE_PRECISION (type)
5850 && 0 > compare_tree_int (TREE_OPERAND (inner, 1),
5851 bitnum - TYPE_PRECISION (type)))
5853 bitnum += TREE_INT_CST_LOW (TREE_OPERAND (inner, 1));
5854 inner = TREE_OPERAND (inner, 0);
5857 /* If we are going to be able to omit the AND below, we must do our
5858 operations as unsigned. If we must use the AND, we have a choice.
5859 Normally unsigned is faster, but for some machines signed is. */
5860 #ifdef LOAD_EXTEND_OP
5861 ops_unsigned = (LOAD_EXTEND_OP (operand_mode) == SIGN_EXTEND ? 0 : 1);
5866 signed_type = lang_hooks.types.type_for_mode (operand_mode, 0);
5867 unsigned_type = lang_hooks.types.type_for_mode (operand_mode, 1);
5868 intermediate_type = ops_unsigned ? unsigned_type : signed_type;
5869 inner = fold_convert (intermediate_type, inner);
5872 inner = build2 (RSHIFT_EXPR, intermediate_type,
5873 inner, size_int (bitnum));
5875 if (code == EQ_EXPR)
5876 inner = fold (build2 (BIT_XOR_EXPR, intermediate_type,
5877 inner, integer_one_node));
5879 /* Put the AND last so it can combine with more things. */
5880 inner = build2 (BIT_AND_EXPR, intermediate_type,
5881 inner, integer_one_node);
5883 /* Make sure to return the proper type. */
5884 inner = fold_convert (result_type, inner);
5891 /* Check whether we are allowed to reorder operands arg0 and arg1,
5892 such that the evaluation of arg1 occurs before arg0. */
5895 reorder_operands_p (tree arg0, tree arg1)
5897 if (! flag_evaluation_order)
5899 if (TREE_CONSTANT (arg0) || TREE_CONSTANT (arg1))
5901 return ! TREE_SIDE_EFFECTS (arg0)
5902 && ! TREE_SIDE_EFFECTS (arg1);
5905 /* Test whether it is preferable two swap two operands, ARG0 and
5906 ARG1, for example because ARG0 is an integer constant and ARG1
5907 isn't. If REORDER is true, only recommend swapping if we can
5908 evaluate the operands in reverse order. */
5911 tree_swap_operands_p (tree arg0, tree arg1, bool reorder)
5913 STRIP_SIGN_NOPS (arg0);
5914 STRIP_SIGN_NOPS (arg1);
5916 if (TREE_CODE (arg1) == INTEGER_CST)
5918 if (TREE_CODE (arg0) == INTEGER_CST)
5921 if (TREE_CODE (arg1) == REAL_CST)
5923 if (TREE_CODE (arg0) == REAL_CST)
5926 if (TREE_CODE (arg1) == COMPLEX_CST)
5928 if (TREE_CODE (arg0) == COMPLEX_CST)
5931 if (TREE_CONSTANT (arg1))
5933 if (TREE_CONSTANT (arg0))
5939 if (reorder && flag_evaluation_order
5940 && (TREE_SIDE_EFFECTS (arg0) || TREE_SIDE_EFFECTS (arg1)))
5948 if (reorder && flag_evaluation_order
5949 && (TREE_SIDE_EFFECTS (arg0) || TREE_SIDE_EFFECTS (arg1)))
5957 /* It is preferable to swap two SSA_NAME to ensure a canonical form
5958 for commutative and comparison operators. Ensuring a canonical
5959 form allows the optimizers to find additional redundancies without
5960 having to explicitly check for both orderings. */
5961 if (TREE_CODE (arg0) == SSA_NAME
5962 && TREE_CODE (arg1) == SSA_NAME
5963 && SSA_NAME_VERSION (arg0) > SSA_NAME_VERSION (arg1))
5969 /* Perform constant folding and related simplification of EXPR.
5970 The related simplifications include x*1 => x, x*0 => 0, etc.,
5971 and application of the associative law.
5972 NOP_EXPR conversions may be removed freely (as long as we
5973 are careful not to change the type of the overall expression).
5974 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
5975 but we can constant-fold them if they have constant operands. */
5977 #ifdef ENABLE_FOLD_CHECKING
5978 # define fold(x) fold_1 (x)
5979 static tree fold_1 (tree);
5985 const tree t = expr;
5986 const tree type = TREE_TYPE (expr);
5987 tree t1 = NULL_TREE;
5989 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
5990 enum tree_code code = TREE_CODE (t);
5991 int kind = TREE_CODE_CLASS (code);
5993 /* WINS will be nonzero when the switch is done
5994 if all operands are constant. */
5997 /* Return right away if a constant. */
6001 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
6005 /* Special case for conversion ops that can have fixed point args. */
6006 arg0 = TREE_OPERAND (t, 0);
6008 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
6010 STRIP_SIGN_NOPS (arg0);
6012 if (arg0 != 0 && TREE_CODE (arg0) == COMPLEX_CST)
6013 subop = TREE_REALPART (arg0);
6017 if (subop != 0 && TREE_CODE (subop) != INTEGER_CST
6018 && TREE_CODE (subop) != REAL_CST)
6019 /* Note that TREE_CONSTANT isn't enough:
6020 static var addresses are constant but we can't
6021 do arithmetic on them. */
6024 else if (IS_EXPR_CODE_CLASS (kind))
6026 int len = first_rtl_op (code);
6028 for (i = 0; i < len; i++)
6030 tree op = TREE_OPERAND (t, i);
6034 continue; /* Valid for CALL_EXPR, at least. */
6036 /* Strip any conversions that don't change the mode. This is
6037 safe for every expression, except for a comparison expression
6038 because its signedness is derived from its operands. So, in
6039 the latter case, only strip conversions that don't change the
6042 Note that this is done as an internal manipulation within the
6043 constant folder, in order to find the simplest representation
6044 of the arguments so that their form can be studied. In any
6045 cases, the appropriate type conversions should be put back in
6046 the tree that will get out of the constant folder. */
6048 STRIP_SIGN_NOPS (op);
6052 if (TREE_CODE (op) == COMPLEX_CST)
6053 subop = TREE_REALPART (op);
6057 if (TREE_CODE (subop) != INTEGER_CST
6058 && TREE_CODE (subop) != REAL_CST)
6059 /* Note that TREE_CONSTANT isn't enough:
6060 static var addresses are constant but we can't
6061 do arithmetic on them. */
6071 /* If this is a commutative operation, and ARG0 is a constant, move it
6072 to ARG1 to reduce the number of tests below. */
6073 if (commutative_tree_code (code)
6074 && tree_swap_operands_p (arg0, arg1, true))
6075 return fold (build2 (code, type, TREE_OPERAND (t, 1),
6076 TREE_OPERAND (t, 0)));
6078 /* Now WINS is set as described above,
6079 ARG0 is the first operand of EXPR,
6080 and ARG1 is the second operand (if it has more than one operand).
6082 First check for cases where an arithmetic operation is applied to a
6083 compound, conditional, or comparison operation. Push the arithmetic
6084 operation inside the compound or conditional to see if any folding
6085 can then be done. Convert comparison to conditional for this purpose.
6086 The also optimizes non-constant cases that used to be done in
6089 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
6090 one of the operands is a comparison and the other is a comparison, a
6091 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
6092 code below would make the expression more complex. Change it to a
6093 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
6094 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
6096 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
6097 || code == EQ_EXPR || code == NE_EXPR)
6098 && ((truth_value_p (TREE_CODE (arg0))
6099 && (truth_value_p (TREE_CODE (arg1))
6100 || (TREE_CODE (arg1) == BIT_AND_EXPR
6101 && integer_onep (TREE_OPERAND (arg1, 1)))))
6102 || (truth_value_p (TREE_CODE (arg1))
6103 && (truth_value_p (TREE_CODE (arg0))
6104 || (TREE_CODE (arg0) == BIT_AND_EXPR
6105 && integer_onep (TREE_OPERAND (arg0, 1)))))))
6107 tem = fold (build2 (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
6108 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
6110 type, fold_convert (boolean_type_node, arg0),
6111 fold_convert (boolean_type_node, arg1)));
6113 if (code == EQ_EXPR)
6114 tem = invert_truthvalue (tem);
6119 if (TREE_CODE_CLASS (code) == '1')
6121 if (TREE_CODE (arg0) == COMPOUND_EXPR)
6122 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
6123 fold (build1 (code, type, TREE_OPERAND (arg0, 1))));
6124 else if (TREE_CODE (arg0) == COND_EXPR)
6126 tree arg01 = TREE_OPERAND (arg0, 1);
6127 tree arg02 = TREE_OPERAND (arg0, 2);
6128 if (! VOID_TYPE_P (TREE_TYPE (arg01)))
6129 arg01 = fold (build1 (code, type, arg01));
6130 if (! VOID_TYPE_P (TREE_TYPE (arg02)))
6131 arg02 = fold (build1 (code, type, arg02));
6132 tem = fold (build3 (COND_EXPR, type, TREE_OPERAND (arg0, 0),
6135 /* If this was a conversion, and all we did was to move into
6136 inside the COND_EXPR, bring it back out. But leave it if
6137 it is a conversion from integer to integer and the
6138 result precision is no wider than a word since such a
6139 conversion is cheap and may be optimized away by combine,
6140 while it couldn't if it were outside the COND_EXPR. Then return
6141 so we don't get into an infinite recursion loop taking the
6142 conversion out and then back in. */
6144 if ((code == NOP_EXPR || code == CONVERT_EXPR
6145 || code == NON_LVALUE_EXPR)
6146 && TREE_CODE (tem) == COND_EXPR
6147 && TREE_CODE (TREE_OPERAND (tem, 1)) == code
6148 && TREE_CODE (TREE_OPERAND (tem, 2)) == code
6149 && ! VOID_TYPE_P (TREE_OPERAND (tem, 1))
6150 && ! VOID_TYPE_P (TREE_OPERAND (tem, 2))
6151 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))
6152 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 2), 0)))
6153 && ! (INTEGRAL_TYPE_P (TREE_TYPE (tem))
6155 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))))
6156 && TYPE_PRECISION (TREE_TYPE (tem)) <= BITS_PER_WORD))
6157 tem = build1 (code, type,
6159 TREE_TYPE (TREE_OPERAND
6160 (TREE_OPERAND (tem, 1), 0)),
6161 TREE_OPERAND (tem, 0),
6162 TREE_OPERAND (TREE_OPERAND (tem, 1), 0),
6163 TREE_OPERAND (TREE_OPERAND (tem, 2), 0)));
6166 else if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<')
6168 if (TREE_CODE (type) == BOOLEAN_TYPE)
6170 arg0 = copy_node (arg0);
6171 TREE_TYPE (arg0) = type;
6174 else if (TREE_CODE (type) != INTEGER_TYPE)
6175 return fold (build3 (COND_EXPR, type, arg0,
6176 fold (build1 (code, type,
6178 fold (build1 (code, type,
6179 integer_zero_node))));
6182 else if (TREE_CODE_CLASS (code) == '<'
6183 && TREE_CODE (arg0) == COMPOUND_EXPR)
6184 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
6185 fold (build2 (code, type, TREE_OPERAND (arg0, 1), arg1)));
6186 else if (TREE_CODE_CLASS (code) == '<'
6187 && TREE_CODE (arg1) == COMPOUND_EXPR)
6188 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
6189 fold (build2 (code, type, arg0, TREE_OPERAND (arg1, 1))));
6190 else if (TREE_CODE_CLASS (code) == '2'
6191 || TREE_CODE_CLASS (code) == '<')
6193 if (TREE_CODE (arg0) == COMPOUND_EXPR)
6194 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
6195 fold (build2 (code, type, TREE_OPERAND (arg0, 1),
6197 if (TREE_CODE (arg1) == COMPOUND_EXPR
6198 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
6199 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
6200 fold (build2 (code, type,
6201 arg0, TREE_OPERAND (arg1, 1))));
6203 if (TREE_CODE (arg0) == COND_EXPR
6204 || TREE_CODE_CLASS (TREE_CODE (arg0)) == '<')
6206 tem = fold_binary_op_with_conditional_arg (code, type, arg0, arg1,
6207 /*cond_first_p=*/1);
6208 if (tem != NULL_TREE)
6212 if (TREE_CODE (arg1) == COND_EXPR
6213 || TREE_CODE_CLASS (TREE_CODE (arg1)) == '<')
6215 tem = fold_binary_op_with_conditional_arg (code, type, arg1, arg0,
6216 /*cond_first_p=*/0);
6217 if (tem != NULL_TREE)
6225 return fold (DECL_INITIAL (t));
6230 case FIX_TRUNC_EXPR:
6232 case FIX_FLOOR_EXPR:
6233 case FIX_ROUND_EXPR:
6234 if (TREE_TYPE (TREE_OPERAND (t, 0)) == type)
6235 return TREE_OPERAND (t, 0);
6237 /* Handle cases of two conversions in a row. */
6238 if (TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
6239 || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR)
6241 tree inside_type = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
6242 tree inter_type = TREE_TYPE (TREE_OPERAND (t, 0));
6243 int inside_int = INTEGRAL_TYPE_P (inside_type);
6244 int inside_ptr = POINTER_TYPE_P (inside_type);
6245 int inside_float = FLOAT_TYPE_P (inside_type);
6246 unsigned int inside_prec = TYPE_PRECISION (inside_type);
6247 int inside_unsignedp = TYPE_UNSIGNED (inside_type);
6248 int inter_int = INTEGRAL_TYPE_P (inter_type);
6249 int inter_ptr = POINTER_TYPE_P (inter_type);
6250 int inter_float = FLOAT_TYPE_P (inter_type);
6251 unsigned int inter_prec = TYPE_PRECISION (inter_type);
6252 int inter_unsignedp = TYPE_UNSIGNED (inter_type);
6253 int final_int = INTEGRAL_TYPE_P (type);
6254 int final_ptr = POINTER_TYPE_P (type);
6255 int final_float = FLOAT_TYPE_P (type);
6256 unsigned int final_prec = TYPE_PRECISION (type);
6257 int final_unsignedp = TYPE_UNSIGNED (type);
6259 /* In addition to the cases of two conversions in a row
6260 handled below, if we are converting something to its own
6261 type via an object of identical or wider precision, neither
6262 conversion is needed. */
6263 if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (type)
6264 && ((inter_int && final_int) || (inter_float && final_float))
6265 && inter_prec >= final_prec)
6266 return fold (build1 (code, type,
6267 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
6269 /* Likewise, if the intermediate and final types are either both
6270 float or both integer, we don't need the middle conversion if
6271 it is wider than the final type and doesn't change the signedness
6272 (for integers). Avoid this if the final type is a pointer
6273 since then we sometimes need the inner conversion. Likewise if
6274 the outer has a precision not equal to the size of its mode. */
6275 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
6276 || (inter_float && inside_float))
6277 && inter_prec >= inside_prec
6278 && (inter_float || inter_unsignedp == inside_unsignedp)
6279 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
6280 && TYPE_MODE (type) == TYPE_MODE (inter_type))
6282 return fold (build1 (code, type,
6283 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
6285 /* If we have a sign-extension of a zero-extended value, we can
6286 replace that by a single zero-extension. */
6287 if (inside_int && inter_int && final_int
6288 && inside_prec < inter_prec && inter_prec < final_prec
6289 && inside_unsignedp && !inter_unsignedp)
6290 return fold (build1 (code, type,
6291 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
6293 /* Two conversions in a row are not needed unless:
6294 - some conversion is floating-point (overstrict for now), or
6295 - the intermediate type is narrower than both initial and
6297 - the intermediate type and innermost type differ in signedness,
6298 and the outermost type is wider than the intermediate, or
6299 - the initial type is a pointer type and the precisions of the
6300 intermediate and final types differ, or
6301 - the final type is a pointer type and the precisions of the
6302 initial and intermediate types differ. */
6303 if (! inside_float && ! inter_float && ! final_float
6304 && (inter_prec > inside_prec || inter_prec > final_prec)
6305 && ! (inside_int && inter_int
6306 && inter_unsignedp != inside_unsignedp
6307 && inter_prec < final_prec)
6308 && ((inter_unsignedp && inter_prec > inside_prec)
6309 == (final_unsignedp && final_prec > inter_prec))
6310 && ! (inside_ptr && inter_prec != final_prec)
6311 && ! (final_ptr && inside_prec != inter_prec)
6312 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
6313 && TYPE_MODE (type) == TYPE_MODE (inter_type))
6315 return fold (build1 (code, type,
6316 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
6319 if (TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR
6320 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t, 0), 1))
6321 /* Detect assigning a bitfield. */
6322 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) == COMPONENT_REF
6323 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 1))))
6325 /* Don't leave an assignment inside a conversion
6326 unless assigning a bitfield. */
6327 tree prev = TREE_OPERAND (t, 0);
6328 tem = copy_node (t);
6329 TREE_OPERAND (tem, 0) = TREE_OPERAND (prev, 1);
6330 /* First do the assignment, then return converted constant. */
6331 tem = build2 (COMPOUND_EXPR, TREE_TYPE (tem), prev, fold (tem));
6332 TREE_NO_WARNING (tem) = 1;
6333 TREE_USED (tem) = 1;
6337 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
6338 constants (if x has signed type, the sign bit cannot be set
6339 in c). This folds extension into the BIT_AND_EXPR. */
6340 if (INTEGRAL_TYPE_P (type)
6341 && TREE_CODE (type) != BOOLEAN_TYPE
6342 && TREE_CODE (TREE_OPERAND (t, 0)) == BIT_AND_EXPR
6343 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 1)) == INTEGER_CST)
6345 tree and = TREE_OPERAND (t, 0);
6346 tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
6349 if (TYPE_UNSIGNED (TREE_TYPE (and))
6350 || (TYPE_PRECISION (type)
6351 <= TYPE_PRECISION (TREE_TYPE (and))))
6353 else if (TYPE_PRECISION (TREE_TYPE (and1))
6354 <= HOST_BITS_PER_WIDE_INT
6355 && host_integerp (and1, 1))
6357 unsigned HOST_WIDE_INT cst;
6359 cst = tree_low_cst (and1, 1);
6360 cst &= (HOST_WIDE_INT) -1
6361 << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
6362 change = (cst == 0);
6363 #ifdef LOAD_EXTEND_OP
6365 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
6368 tree uns = lang_hooks.types.unsigned_type (TREE_TYPE (and0));
6369 and0 = fold_convert (uns, and0);
6370 and1 = fold_convert (uns, and1);
6375 return fold (build2 (BIT_AND_EXPR, type,
6376 fold_convert (type, and0),
6377 fold_convert (type, and1)));
6380 /* Convert (T1)((T2)X op Y) into (T1)X op Y, for pointer types T1 and
6381 T2 being pointers to types of the same size. */
6382 if (POINTER_TYPE_P (TREE_TYPE (t))
6383 && TREE_CODE_CLASS (TREE_CODE (arg0)) == '2'
6384 && TREE_CODE (TREE_OPERAND (arg0, 0)) == NOP_EXPR
6385 && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 0))))
6387 tree arg00 = TREE_OPERAND (arg0, 0);
6388 tree t0 = TREE_TYPE (t);
6389 tree t1 = TREE_TYPE (arg00);
6390 tree tt0 = TREE_TYPE (t0);
6391 tree tt1 = TREE_TYPE (t1);
6392 tree s0 = TYPE_SIZE (tt0);
6393 tree s1 = TYPE_SIZE (tt1);
6395 if (s0 && s1 && operand_equal_p (s0, s1, OEP_ONLY_CONST))
6396 return build2 (TREE_CODE (arg0), t0, fold_convert (t0, arg00),
6397 TREE_OPERAND (arg0, 1));
6400 tem = fold_convert_const (code, type, arg0);
6401 return tem ? tem : t;
6403 case VIEW_CONVERT_EXPR:
6404 if (TREE_CODE (TREE_OPERAND (t, 0)) == VIEW_CONVERT_EXPR)
6405 return build1 (VIEW_CONVERT_EXPR, type,
6406 TREE_OPERAND (TREE_OPERAND (t, 0), 0));
6410 if (TREE_CODE (arg0) == CONSTRUCTOR
6411 && ! type_contains_placeholder_p (TREE_TYPE (arg0)))
6413 tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0));
6415 return TREE_VALUE (m);
6420 if (TREE_CONSTANT (t) != wins)
6422 tem = copy_node (t);
6423 TREE_CONSTANT (tem) = wins;
6424 TREE_INVARIANT (tem) = wins;
6430 if (negate_expr_p (arg0))
6431 return fold_convert (type, negate_expr (arg0));
6435 if (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST)
6436 return fold_abs_const (arg0, type);
6437 else if (TREE_CODE (arg0) == NEGATE_EXPR)
6438 return fold (build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0)));
6439 /* Convert fabs((double)float) into (double)fabsf(float). */
6440 else if (TREE_CODE (arg0) == NOP_EXPR
6441 && TREE_CODE (type) == REAL_TYPE)
6443 tree targ0 = strip_float_extensions (arg0);
6445 return fold_convert (type, fold (build1 (ABS_EXPR,
6449 else if (tree_expr_nonnegative_p (arg0))
6454 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
6455 return fold_convert (type, arg0);
6456 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
6457 return build2 (COMPLEX_EXPR, type,
6458 TREE_OPERAND (arg0, 0),
6459 negate_expr (TREE_OPERAND (arg0, 1)));
6460 else if (TREE_CODE (arg0) == COMPLEX_CST)
6461 return build_complex (type, TREE_REALPART (arg0),
6462 negate_expr (TREE_IMAGPART (arg0)));
6463 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
6464 return fold (build2 (TREE_CODE (arg0), type,
6465 fold (build1 (CONJ_EXPR, type,
6466 TREE_OPERAND (arg0, 0))),
6467 fold (build1 (CONJ_EXPR, type,
6468 TREE_OPERAND (arg0, 1)))));
6469 else if (TREE_CODE (arg0) == CONJ_EXPR)
6470 return TREE_OPERAND (arg0, 0);
6474 if (TREE_CODE (arg0) == INTEGER_CST)
6475 return fold_not_const (arg0, type);
6476 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
6477 return TREE_OPERAND (arg0, 0);
6481 /* A + (-B) -> A - B */
6482 if (TREE_CODE (arg1) == NEGATE_EXPR)
6483 return fold (build2 (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
6484 /* (-A) + B -> B - A */
6485 if (TREE_CODE (arg0) == NEGATE_EXPR
6486 && reorder_operands_p (TREE_OPERAND (arg0, 0), arg1))
6487 return fold (build2 (MINUS_EXPR, type, arg1, TREE_OPERAND (arg0, 0)));
6488 if (! FLOAT_TYPE_P (type))
6490 if (integer_zerop (arg1))
6491 return non_lvalue (fold_convert (type, arg0));
6493 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
6494 with a constant, and the two constants have no bits in common,
6495 we should treat this as a BIT_IOR_EXPR since this may produce more
6497 if (TREE_CODE (arg0) == BIT_AND_EXPR
6498 && TREE_CODE (arg1) == BIT_AND_EXPR
6499 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6500 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
6501 && integer_zerop (const_binop (BIT_AND_EXPR,
6502 TREE_OPERAND (arg0, 1),
6503 TREE_OPERAND (arg1, 1), 0)))
6505 code = BIT_IOR_EXPR;
6509 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
6510 (plus (plus (mult) (mult)) (foo)) so that we can
6511 take advantage of the factoring cases below. */
6512 if ((TREE_CODE (arg0) == PLUS_EXPR
6513 && TREE_CODE (arg1) == MULT_EXPR)
6514 || (TREE_CODE (arg1) == PLUS_EXPR
6515 && TREE_CODE (arg0) == MULT_EXPR))
6517 tree parg0, parg1, parg, marg;
6519 if (TREE_CODE (arg0) == PLUS_EXPR)
6520 parg = arg0, marg = arg1;
6522 parg = arg1, marg = arg0;
6523 parg0 = TREE_OPERAND (parg, 0);
6524 parg1 = TREE_OPERAND (parg, 1);
6528 if (TREE_CODE (parg0) == MULT_EXPR
6529 && TREE_CODE (parg1) != MULT_EXPR)
6530 return fold (build2 (PLUS_EXPR, type,
6531 fold (build2 (PLUS_EXPR, type,
6532 fold_convert (type, parg0),
6533 fold_convert (type, marg))),
6534 fold_convert (type, parg1)));
6535 if (TREE_CODE (parg0) != MULT_EXPR
6536 && TREE_CODE (parg1) == MULT_EXPR)
6537 return fold (build2 (PLUS_EXPR, type,
6538 fold (build2 (PLUS_EXPR, type,
6539 fold_convert (type, parg1),
6540 fold_convert (type, marg))),
6541 fold_convert (type, parg0)));
6544 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR)
6546 tree arg00, arg01, arg10, arg11;
6547 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
6549 /* (A * C) + (B * C) -> (A+B) * C.
6550 We are most concerned about the case where C is a constant,
6551 but other combinations show up during loop reduction. Since
6552 it is not difficult, try all four possibilities. */
6554 arg00 = TREE_OPERAND (arg0, 0);
6555 arg01 = TREE_OPERAND (arg0, 1);
6556 arg10 = TREE_OPERAND (arg1, 0);
6557 arg11 = TREE_OPERAND (arg1, 1);
6560 if (operand_equal_p (arg01, arg11, 0))
6561 same = arg01, alt0 = arg00, alt1 = arg10;
6562 else if (operand_equal_p (arg00, arg10, 0))
6563 same = arg00, alt0 = arg01, alt1 = arg11;
6564 else if (operand_equal_p (arg00, arg11, 0))
6565 same = arg00, alt0 = arg01, alt1 = arg10;
6566 else if (operand_equal_p (arg01, arg10, 0))
6567 same = arg01, alt0 = arg00, alt1 = arg11;
6569 /* No identical multiplicands; see if we can find a common
6570 power-of-two factor in non-power-of-two multiplies. This
6571 can help in multi-dimensional array access. */
6572 else if (TREE_CODE (arg01) == INTEGER_CST
6573 && TREE_CODE (arg11) == INTEGER_CST
6574 && TREE_INT_CST_HIGH (arg01) == 0
6575 && TREE_INT_CST_HIGH (arg11) == 0)
6577 HOST_WIDE_INT int01, int11, tmp;
6578 int01 = TREE_INT_CST_LOW (arg01);
6579 int11 = TREE_INT_CST_LOW (arg11);
6581 /* Move min of absolute values to int11. */
6582 if ((int01 >= 0 ? int01 : -int01)
6583 < (int11 >= 0 ? int11 : -int11))
6585 tmp = int01, int01 = int11, int11 = tmp;
6586 alt0 = arg00, arg00 = arg10, arg10 = alt0;
6587 alt0 = arg01, arg01 = arg11, arg11 = alt0;
6590 if (exact_log2 (int11) > 0 && int01 % int11 == 0)
6592 alt0 = fold (build2 (MULT_EXPR, type, arg00,
6593 build_int_2 (int01 / int11, 0)));
6600 return fold (build2 (MULT_EXPR, type,
6601 fold (build2 (PLUS_EXPR, type,
6608 /* See if ARG1 is zero and X + ARG1 reduces to X. */
6609 if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
6610 return non_lvalue (fold_convert (type, arg0));
6612 /* Likewise if the operands are reversed. */
6613 if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
6614 return non_lvalue (fold_convert (type, arg1));
6616 /* Convert X + -C into X - C. */
6617 if (TREE_CODE (arg1) == REAL_CST
6618 && REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1)))
6620 tem = fold_negate_const (arg1, type);
6621 if (!TREE_OVERFLOW (arg1) || !flag_trapping_math)
6622 return fold (build2 (MINUS_EXPR, type,
6623 fold_convert (type, arg0),
6624 fold_convert (type, tem)));
6627 /* Convert x+x into x*2.0. */
6628 if (operand_equal_p (arg0, arg1, 0)
6629 && SCALAR_FLOAT_TYPE_P (type))
6630 return fold (build2 (MULT_EXPR, type, arg0,
6631 build_real (type, dconst2)));
6633 /* Convert x*c+x into x*(c+1). */
6634 if (flag_unsafe_math_optimizations
6635 && TREE_CODE (arg0) == MULT_EXPR
6636 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
6637 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0, 1))
6638 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
6642 c = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
6643 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
6644 return fold (build2 (MULT_EXPR, type, arg1,
6645 build_real (type, c)));
6648 /* Convert x+x*c into x*(c+1). */
6649 if (flag_unsafe_math_optimizations
6650 && TREE_CODE (arg1) == MULT_EXPR
6651 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST
6652 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1, 1))
6653 && operand_equal_p (TREE_OPERAND (arg1, 0), arg0, 0))
6657 c = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
6658 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
6659 return fold (build2 (MULT_EXPR, type, arg0,
6660 build_real (type, c)));
6663 /* Convert x*c1+x*c2 into x*(c1+c2). */
6664 if (flag_unsafe_math_optimizations
6665 && TREE_CODE (arg0) == MULT_EXPR
6666 && TREE_CODE (arg1) == MULT_EXPR
6667 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
6668 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0, 1))
6669 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST
6670 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1, 1))
6671 && operand_equal_p (TREE_OPERAND (arg0, 0),
6672 TREE_OPERAND (arg1, 0), 0))
6674 REAL_VALUE_TYPE c1, c2;
6676 c1 = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
6677 c2 = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
6678 real_arithmetic (&c1, PLUS_EXPR, &c1, &c2);
6679 return fold (build2 (MULT_EXPR, type,
6680 TREE_OPERAND (arg0, 0),
6681 build_real (type, c1)));
6683 /* Convert a + (b*c + d*e) into (a + b*c) + d*e */
6684 if (flag_unsafe_math_optimizations
6685 && TREE_CODE (arg1) == PLUS_EXPR
6686 && TREE_CODE (arg0) != MULT_EXPR)
6688 tree tree10 = TREE_OPERAND (arg1, 0);
6689 tree tree11 = TREE_OPERAND (arg1, 1);
6690 if (TREE_CODE (tree11) == MULT_EXPR
6691 && TREE_CODE (tree10) == MULT_EXPR)
6694 tree0 = fold (build2 (PLUS_EXPR, type, arg0, tree10));
6695 return fold (build2 (PLUS_EXPR, type, tree0, tree11));
6698 /* Convert (b*c + d*e) + a into b*c + (d*e +a) */
6699 if (flag_unsafe_math_optimizations
6700 && TREE_CODE (arg0) == PLUS_EXPR
6701 && TREE_CODE (arg1) != MULT_EXPR)
6703 tree tree00 = TREE_OPERAND (arg0, 0);
6704 tree tree01 = TREE_OPERAND (arg0, 1);
6705 if (TREE_CODE (tree01) == MULT_EXPR
6706 && TREE_CODE (tree00) == MULT_EXPR)
6709 tree0 = fold (build2 (PLUS_EXPR, type, tree01, arg1));
6710 return fold (build2 (PLUS_EXPR, type, tree00, tree0));
6716 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
6717 is a rotate of A by C1 bits. */
6718 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
6719 is a rotate of A by B bits. */
6721 enum tree_code code0, code1;
6722 code0 = TREE_CODE (arg0);
6723 code1 = TREE_CODE (arg1);
6724 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
6725 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
6726 && operand_equal_p (TREE_OPERAND (arg0, 0),
6727 TREE_OPERAND (arg1, 0), 0)
6728 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
6730 tree tree01, tree11;
6731 enum tree_code code01, code11;
6733 tree01 = TREE_OPERAND (arg0, 1);
6734 tree11 = TREE_OPERAND (arg1, 1);
6735 STRIP_NOPS (tree01);
6736 STRIP_NOPS (tree11);
6737 code01 = TREE_CODE (tree01);
6738 code11 = TREE_CODE (tree11);
6739 if (code01 == INTEGER_CST
6740 && code11 == INTEGER_CST
6741 && TREE_INT_CST_HIGH (tree01) == 0
6742 && TREE_INT_CST_HIGH (tree11) == 0
6743 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
6744 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
6745 return build2 (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
6746 code0 == LSHIFT_EXPR ? tree01 : tree11);
6747 else if (code11 == MINUS_EXPR)
6749 tree tree110, tree111;
6750 tree110 = TREE_OPERAND (tree11, 0);
6751 tree111 = TREE_OPERAND (tree11, 1);
6752 STRIP_NOPS (tree110);
6753 STRIP_NOPS (tree111);
6754 if (TREE_CODE (tree110) == INTEGER_CST
6755 && 0 == compare_tree_int (tree110,
6757 (TREE_TYPE (TREE_OPERAND
6759 && operand_equal_p (tree01, tree111, 0))
6760 return build2 ((code0 == LSHIFT_EXPR
6763 type, TREE_OPERAND (arg0, 0), tree01);
6765 else if (code01 == MINUS_EXPR)
6767 tree tree010, tree011;
6768 tree010 = TREE_OPERAND (tree01, 0);
6769 tree011 = TREE_OPERAND (tree01, 1);
6770 STRIP_NOPS (tree010);
6771 STRIP_NOPS (tree011);
6772 if (TREE_CODE (tree010) == INTEGER_CST
6773 && 0 == compare_tree_int (tree010,
6775 (TREE_TYPE (TREE_OPERAND
6777 && operand_equal_p (tree11, tree011, 0))
6778 return build2 ((code0 != LSHIFT_EXPR
6781 type, TREE_OPERAND (arg0, 0), tree11);
6787 /* In most languages, can't associate operations on floats through
6788 parentheses. Rather than remember where the parentheses were, we
6789 don't associate floats at all, unless the user has specified
6790 -funsafe-math-optimizations. */
6793 && (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
6795 tree var0, con0, lit0, minus_lit0;
6796 tree var1, con1, lit1, minus_lit1;
6798 /* Split both trees into variables, constants, and literals. Then
6799 associate each group together, the constants with literals,
6800 then the result with variables. This increases the chances of
6801 literals being recombined later and of generating relocatable
6802 expressions for the sum of a constant and literal. */
6803 var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
6804 var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
6805 code == MINUS_EXPR);
6807 /* Only do something if we found more than two objects. Otherwise,
6808 nothing has changed and we risk infinite recursion. */
6809 if (2 < ((var0 != 0) + (var1 != 0)
6810 + (con0 != 0) + (con1 != 0)
6811 + (lit0 != 0) + (lit1 != 0)
6812 + (minus_lit0 != 0) + (minus_lit1 != 0)))
6814 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
6815 if (code == MINUS_EXPR)
6818 var0 = associate_trees (var0, var1, code, type);
6819 con0 = associate_trees (con0, con1, code, type);
6820 lit0 = associate_trees (lit0, lit1, code, type);
6821 minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
6823 /* Preserve the MINUS_EXPR if the negative part of the literal is
6824 greater than the positive part. Otherwise, the multiplicative
6825 folding code (i.e extract_muldiv) may be fooled in case
6826 unsigned constants are subtracted, like in the following
6827 example: ((X*2 + 4) - 8U)/2. */
6828 if (minus_lit0 && lit0)
6830 if (TREE_CODE (lit0) == INTEGER_CST
6831 && TREE_CODE (minus_lit0) == INTEGER_CST
6832 && tree_int_cst_lt (lit0, minus_lit0))
6834 minus_lit0 = associate_trees (minus_lit0, lit0,
6840 lit0 = associate_trees (lit0, minus_lit0,
6848 return fold_convert (type,
6849 associate_trees (var0, minus_lit0,
6853 con0 = associate_trees (con0, minus_lit0,
6855 return fold_convert (type,
6856 associate_trees (var0, con0,
6861 con0 = associate_trees (con0, lit0, code, type);
6862 return fold_convert (type, associate_trees (var0, con0,
6869 t1 = const_binop (code, arg0, arg1, 0);
6870 if (t1 != NULL_TREE)
6872 /* The return value should always have
6873 the same type as the original expression. */
6874 if (TREE_TYPE (t1) != type)
6875 t1 = fold_convert (type, t1);
6882 /* A - (-B) -> A + B */
6883 if (TREE_CODE (arg1) == NEGATE_EXPR)
6884 return fold (build2 (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
6885 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
6886 if (TREE_CODE (arg0) == NEGATE_EXPR
6887 && (FLOAT_TYPE_P (type)
6888 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv))
6889 && negate_expr_p (arg1)
6890 && reorder_operands_p (arg0, arg1))
6891 return fold (build2 (MINUS_EXPR, type, negate_expr (arg1),
6892 TREE_OPERAND (arg0, 0)));
6894 if (! FLOAT_TYPE_P (type))
6896 if (! wins && integer_zerop (arg0))
6897 return negate_expr (fold_convert (type, arg1));
6898 if (integer_zerop (arg1))
6899 return non_lvalue (fold_convert (type, arg0));
6901 /* Fold A - (A & B) into ~B & A. */
6902 if (!TREE_SIDE_EFFECTS (arg0)
6903 && TREE_CODE (arg1) == BIT_AND_EXPR)
6905 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
6906 return fold (build2 (BIT_AND_EXPR, type,
6907 fold (build1 (BIT_NOT_EXPR, type,
6908 TREE_OPERAND (arg1, 0))),
6910 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
6911 return fold (build2 (BIT_AND_EXPR, type,
6912 fold (build1 (BIT_NOT_EXPR, type,
6913 TREE_OPERAND (arg1, 1))),
6917 /* Fold (A & ~B) - (A & B) into (A ^ B) - B, where B is
6918 any power of 2 minus 1. */
6919 if (TREE_CODE (arg0) == BIT_AND_EXPR
6920 && TREE_CODE (arg1) == BIT_AND_EXPR
6921 && operand_equal_p (TREE_OPERAND (arg0, 0),
6922 TREE_OPERAND (arg1, 0), 0))
6924 tree mask0 = TREE_OPERAND (arg0, 1);
6925 tree mask1 = TREE_OPERAND (arg1, 1);
6926 tree tem = fold (build1 (BIT_NOT_EXPR, type, mask0));
6928 if (operand_equal_p (tem, mask1, 0))
6930 tem = fold (build2 (BIT_XOR_EXPR, type,
6931 TREE_OPERAND (arg0, 0), mask1));
6932 return fold (build2 (MINUS_EXPR, type, tem, mask1));
6937 /* See if ARG1 is zero and X - ARG1 reduces to X. */
6938 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
6939 return non_lvalue (fold_convert (type, arg0));
6941 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
6942 ARG0 is zero and X + ARG0 reduces to X, since that would mean
6943 (-ARG1 + ARG0) reduces to -ARG1. */
6944 else if (!wins && fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
6945 return negate_expr (fold_convert (type, arg1));
6947 /* Fold &x - &x. This can happen from &x.foo - &x.
6948 This is unsafe for certain floats even in non-IEEE formats.
6949 In IEEE, it is unsafe because it does wrong for NaNs.
6950 Also note that operand_equal_p is always false if an operand
6953 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
6954 && operand_equal_p (arg0, arg1, 0))
6955 return fold_convert (type, integer_zero_node);
6957 /* A - B -> A + (-B) if B is easily negatable. */
6958 if (!wins && negate_expr_p (arg1)
6959 && ((FLOAT_TYPE_P (type)
6960 /* Avoid this transformation if B is a positive REAL_CST. */
6961 && (TREE_CODE (arg1) != REAL_CST
6962 || REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1))))
6963 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv)))
6964 return fold (build2 (PLUS_EXPR, type, arg0, negate_expr (arg1)));
6966 if (TREE_CODE (arg0) == MULT_EXPR
6967 && TREE_CODE (arg1) == MULT_EXPR
6968 && (INTEGRAL_TYPE_P (type) || flag_unsafe_math_optimizations))
6970 /* (A * C) - (B * C) -> (A-B) * C. */
6971 if (operand_equal_p (TREE_OPERAND (arg0, 1),
6972 TREE_OPERAND (arg1, 1), 0))
6973 return fold (build2 (MULT_EXPR, type,
6974 fold (build2 (MINUS_EXPR, type,
6975 TREE_OPERAND (arg0, 0),
6976 TREE_OPERAND (arg1, 0))),
6977 TREE_OPERAND (arg0, 1)));
6978 /* (A * C1) - (A * C2) -> A * (C1-C2). */
6979 if (operand_equal_p (TREE_OPERAND (arg0, 0),
6980 TREE_OPERAND (arg1, 0), 0))
6981 return fold (build2 (MULT_EXPR, type,
6982 TREE_OPERAND (arg0, 0),
6983 fold (build2 (MINUS_EXPR, type,
6984 TREE_OPERAND (arg0, 1),
6985 TREE_OPERAND (arg1, 1)))));
6991 /* (-A) * (-B) -> A * B */
6992 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
6993 return fold (build2 (MULT_EXPR, type,
6994 TREE_OPERAND (arg0, 0),
6995 negate_expr (arg1)));
6996 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
6997 return fold (build2 (MULT_EXPR, type,
6999 TREE_OPERAND (arg1, 0)));
7001 if (! FLOAT_TYPE_P (type))
7003 if (integer_zerop (arg1))
7004 return omit_one_operand (type, arg1, arg0);
7005 if (integer_onep (arg1))
7006 return non_lvalue (fold_convert (type, arg0));
7008 /* (a * (1 << b)) is (a << b) */
7009 if (TREE_CODE (arg1) == LSHIFT_EXPR
7010 && integer_onep (TREE_OPERAND (arg1, 0)))
7011 return fold (build2 (LSHIFT_EXPR, type, arg0,
7012 TREE_OPERAND (arg1, 1)));
7013 if (TREE_CODE (arg0) == LSHIFT_EXPR
7014 && integer_onep (TREE_OPERAND (arg0, 0)))
7015 return fold (build2 (LSHIFT_EXPR, type, arg1,
7016 TREE_OPERAND (arg0, 1)));
7018 if (TREE_CODE (arg1) == INTEGER_CST
7019 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0),
7020 fold_convert (type, arg1),
7022 return fold_convert (type, tem);
7027 /* Maybe fold x * 0 to 0. The expressions aren't the same
7028 when x is NaN, since x * 0 is also NaN. Nor are they the
7029 same in modes with signed zeros, since multiplying a
7030 negative value by 0 gives -0, not +0. */
7031 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
7032 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
7033 && real_zerop (arg1))
7034 return omit_one_operand (type, arg1, arg0);
7035 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
7036 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
7037 && real_onep (arg1))
7038 return non_lvalue (fold_convert (type, arg0));
7040 /* Transform x * -1.0 into -x. */
7041 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
7042 && real_minus_onep (arg1))
7043 return fold_convert (type, negate_expr (arg0));
7045 /* Convert (C1/X)*C2 into (C1*C2)/X. */
7046 if (flag_unsafe_math_optimizations
7047 && TREE_CODE (arg0) == RDIV_EXPR
7048 && TREE_CODE (arg1) == REAL_CST
7049 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST)
7051 tree tem = const_binop (MULT_EXPR, TREE_OPERAND (arg0, 0),
7054 return fold (build2 (RDIV_EXPR, type, tem,
7055 TREE_OPERAND (arg0, 1)));
7058 if (flag_unsafe_math_optimizations)
7060 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
7061 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
7063 /* Optimizations of root(...)*root(...). */
7064 if (fcode0 == fcode1 && BUILTIN_ROOT_P (fcode0))
7066 tree rootfn, arg, arglist;
7067 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
7068 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
7070 /* Optimize sqrt(x)*sqrt(x) as x. */
7071 if (BUILTIN_SQRT_P (fcode0)
7072 && operand_equal_p (arg00, arg10, 0)
7073 && ! HONOR_SNANS (TYPE_MODE (type)))
7076 /* Optimize root(x)*root(y) as root(x*y). */
7077 rootfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7078 arg = fold (build2 (MULT_EXPR, type, arg00, arg10));
7079 arglist = build_tree_list (NULL_TREE, arg);
7080 return build_function_call_expr (rootfn, arglist);
7083 /* Optimize expN(x)*expN(y) as expN(x+y). */
7084 if (fcode0 == fcode1 && BUILTIN_EXPONENT_P (fcode0))
7086 tree expfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7087 tree arg = build2 (PLUS_EXPR, type,
7088 TREE_VALUE (TREE_OPERAND (arg0, 1)),
7089 TREE_VALUE (TREE_OPERAND (arg1, 1)));
7090 tree arglist = build_tree_list (NULL_TREE, fold (arg));
7091 return build_function_call_expr (expfn, arglist);
7094 /* Optimizations of pow(...)*pow(...). */
7095 if ((fcode0 == BUILT_IN_POW && fcode1 == BUILT_IN_POW)
7096 || (fcode0 == BUILT_IN_POWF && fcode1 == BUILT_IN_POWF)
7097 || (fcode0 == BUILT_IN_POWL && fcode1 == BUILT_IN_POWL))
7099 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
7100 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
7102 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
7103 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
7106 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
7107 if (operand_equal_p (arg01, arg11, 0))
7109 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7110 tree arg = build2 (MULT_EXPR, type, arg00, arg10);
7111 tree arglist = tree_cons (NULL_TREE, fold (arg),
7112 build_tree_list (NULL_TREE,
7114 return build_function_call_expr (powfn, arglist);
7117 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
7118 if (operand_equal_p (arg00, arg10, 0))
7120 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7121 tree arg = fold (build2 (PLUS_EXPR, type, arg01, arg11));
7122 tree arglist = tree_cons (NULL_TREE, arg00,
7123 build_tree_list (NULL_TREE,
7125 return build_function_call_expr (powfn, arglist);
7129 /* Optimize tan(x)*cos(x) as sin(x). */
7130 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_COS)
7131 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_COSF)
7132 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_COSL)
7133 || (fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_TAN)
7134 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_TANF)
7135 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_TANL))
7136 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
7137 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
7139 tree sinfn = mathfn_built_in (type, BUILT_IN_SIN);
7141 if (sinfn != NULL_TREE)
7142 return build_function_call_expr (sinfn,
7143 TREE_OPERAND (arg0, 1));
7146 /* Optimize x*pow(x,c) as pow(x,c+1). */
7147 if (fcode1 == BUILT_IN_POW
7148 || fcode1 == BUILT_IN_POWF
7149 || fcode1 == BUILT_IN_POWL)
7151 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
7152 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
7154 if (TREE_CODE (arg11) == REAL_CST
7155 && ! TREE_CONSTANT_OVERFLOW (arg11)
7156 && operand_equal_p (arg0, arg10, 0))
7158 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
7162 c = TREE_REAL_CST (arg11);
7163 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
7164 arg = build_real (type, c);
7165 arglist = build_tree_list (NULL_TREE, arg);
7166 arglist = tree_cons (NULL_TREE, arg0, arglist);
7167 return build_function_call_expr (powfn, arglist);
7171 /* Optimize pow(x,c)*x as pow(x,c+1). */
7172 if (fcode0 == BUILT_IN_POW
7173 || fcode0 == BUILT_IN_POWF
7174 || fcode0 == BUILT_IN_POWL)
7176 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
7177 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
7179 if (TREE_CODE (arg01) == REAL_CST
7180 && ! TREE_CONSTANT_OVERFLOW (arg01)
7181 && operand_equal_p (arg1, arg00, 0))
7183 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7187 c = TREE_REAL_CST (arg01);
7188 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
7189 arg = build_real (type, c);
7190 arglist = build_tree_list (NULL_TREE, arg);
7191 arglist = tree_cons (NULL_TREE, arg1, arglist);
7192 return build_function_call_expr (powfn, arglist);
7196 /* Optimize x*x as pow(x,2.0), which is expanded as x*x. */
7198 && operand_equal_p (arg0, arg1, 0))
7200 tree powfn = mathfn_built_in (type, BUILT_IN_POW);
7204 tree arg = build_real (type, dconst2);
7205 tree arglist = build_tree_list (NULL_TREE, arg);
7206 arglist = tree_cons (NULL_TREE, arg0, arglist);
7207 return build_function_call_expr (powfn, arglist);
7216 if (integer_all_onesp (arg1))
7217 return omit_one_operand (type, arg1, arg0);
7218 if (integer_zerop (arg1))
7219 return non_lvalue (fold_convert (type, arg0));
7220 if (operand_equal_p (arg0, arg1, 0))
7221 return non_lvalue (fold_convert (type, arg0));
7224 if (TREE_CODE (arg0) == BIT_NOT_EXPR
7225 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
7227 t1 = build_int_2 (-1, -1);
7228 TREE_TYPE (t1) = type;
7229 force_fit_type (t1, 0);
7230 return omit_one_operand (type, t1, arg1);
7234 if (TREE_CODE (arg1) == BIT_NOT_EXPR
7235 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
7237 t1 = build_int_2 (-1, -1);
7238 TREE_TYPE (t1) = type;
7239 force_fit_type (t1, 0);
7240 return omit_one_operand (type, t1, arg0);
7243 t1 = distribute_bit_expr (code, type, arg0, arg1);
7244 if (t1 != NULL_TREE)
7247 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
7249 This results in more efficient code for machines without a NAND
7250 instruction. Combine will canonicalize to the first form
7251 which will allow use of NAND instructions provided by the
7252 backend if they exist. */
7253 if (TREE_CODE (arg0) == BIT_NOT_EXPR
7254 && TREE_CODE (arg1) == BIT_NOT_EXPR)
7256 return fold (build1 (BIT_NOT_EXPR, type,
7257 build2 (BIT_AND_EXPR, type,
7258 TREE_OPERAND (arg0, 0),
7259 TREE_OPERAND (arg1, 0))));
7262 /* See if this can be simplified into a rotate first. If that
7263 is unsuccessful continue in the association code. */
7267 if (integer_zerop (arg1))
7268 return non_lvalue (fold_convert (type, arg0));
7269 if (integer_all_onesp (arg1))
7270 return fold (build1 (BIT_NOT_EXPR, type, arg0));
7271 if (operand_equal_p (arg0, arg1, 0))
7272 return omit_one_operand (type, integer_zero_node, arg0);
7275 if (TREE_CODE (arg0) == BIT_NOT_EXPR
7276 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
7278 t1 = build_int_2 (-1, -1);
7279 TREE_TYPE (t1) = type;
7280 force_fit_type (t1, 0);
7281 return omit_one_operand (type, t1, arg1);
7285 if (TREE_CODE (arg1) == BIT_NOT_EXPR
7286 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
7288 t1 = build_int_2 (-1, -1);
7289 TREE_TYPE (t1) = type;
7290 force_fit_type (t1, 0);
7291 return omit_one_operand (type, t1, arg0);
7294 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
7295 with a constant, and the two constants have no bits in common,
7296 we should treat this as a BIT_IOR_EXPR since this may produce more
7298 if (TREE_CODE (arg0) == BIT_AND_EXPR
7299 && TREE_CODE (arg1) == BIT_AND_EXPR
7300 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7301 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
7302 && integer_zerop (const_binop (BIT_AND_EXPR,
7303 TREE_OPERAND (arg0, 1),
7304 TREE_OPERAND (arg1, 1), 0)))
7306 code = BIT_IOR_EXPR;
7310 /* See if this can be simplified into a rotate first. If that
7311 is unsuccessful continue in the association code. */
7315 if (integer_all_onesp (arg1))
7316 return non_lvalue (fold_convert (type, arg0));
7317 if (integer_zerop (arg1))
7318 return omit_one_operand (type, arg1, arg0);
7319 if (operand_equal_p (arg0, arg1, 0))
7320 return non_lvalue (fold_convert (type, arg0));
7322 /* ~X & X is always zero. */
7323 if (TREE_CODE (arg0) == BIT_NOT_EXPR
7324 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
7325 return omit_one_operand (type, integer_zero_node, arg1);
7327 /* X & ~X is always zero. */
7328 if (TREE_CODE (arg1) == BIT_NOT_EXPR
7329 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
7330 return omit_one_operand (type, integer_zero_node, arg0);
7332 t1 = distribute_bit_expr (code, type, arg0, arg1);
7333 if (t1 != NULL_TREE)
7335 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
7336 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
7337 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
7340 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
7342 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
7343 && (~TREE_INT_CST_LOW (arg1)
7344 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
7345 return fold_convert (type, TREE_OPERAND (arg0, 0));
7348 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
7350 This results in more efficient code for machines without a NOR
7351 instruction. Combine will canonicalize to the first form
7352 which will allow use of NOR instructions provided by the
7353 backend if they exist. */
7354 if (TREE_CODE (arg0) == BIT_NOT_EXPR
7355 && TREE_CODE (arg1) == BIT_NOT_EXPR)
7357 return fold (build1 (BIT_NOT_EXPR, type,
7358 build2 (BIT_IOR_EXPR, type,
7359 TREE_OPERAND (arg0, 0),
7360 TREE_OPERAND (arg1, 0))));
7366 /* Don't touch a floating-point divide by zero unless the mode
7367 of the constant can represent infinity. */
7368 if (TREE_CODE (arg1) == REAL_CST
7369 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
7370 && real_zerop (arg1))
7373 /* (-A) / (-B) -> A / B */
7374 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
7375 return fold (build2 (RDIV_EXPR, type,
7376 TREE_OPERAND (arg0, 0),
7377 negate_expr (arg1)));
7378 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
7379 return fold (build2 (RDIV_EXPR, type,
7381 TREE_OPERAND (arg1, 0)));
7383 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
7384 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
7385 && real_onep (arg1))
7386 return non_lvalue (fold_convert (type, arg0));
7388 /* In IEEE floating point, x/-1 is not equivalent to -x for snans. */
7389 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
7390 && real_minus_onep (arg1))
7391 return non_lvalue (fold_convert (type, negate_expr (arg0)));
7393 /* If ARG1 is a constant, we can convert this to a multiply by the
7394 reciprocal. This does not have the same rounding properties,
7395 so only do this if -funsafe-math-optimizations. We can actually
7396 always safely do it if ARG1 is a power of two, but it's hard to
7397 tell if it is or not in a portable manner. */
7398 if (TREE_CODE (arg1) == REAL_CST)
7400 if (flag_unsafe_math_optimizations
7401 && 0 != (tem = const_binop (code, build_real (type, dconst1),
7403 return fold (build2 (MULT_EXPR, type, arg0, tem));
7404 /* Find the reciprocal if optimizing and the result is exact. */
7408 r = TREE_REAL_CST (arg1);
7409 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
7411 tem = build_real (type, r);
7412 return fold (build2 (MULT_EXPR, type, arg0, tem));
7416 /* Convert A/B/C to A/(B*C). */
7417 if (flag_unsafe_math_optimizations
7418 && TREE_CODE (arg0) == RDIV_EXPR)
7419 return fold (build2 (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
7420 fold (build2 (MULT_EXPR, type,
7421 TREE_OPERAND (arg0, 1), arg1))));
7423 /* Convert A/(B/C) to (A/B)*C. */
7424 if (flag_unsafe_math_optimizations
7425 && TREE_CODE (arg1) == RDIV_EXPR)
7426 return fold (build2 (MULT_EXPR, type,
7427 fold (build2 (RDIV_EXPR, type, arg0,
7428 TREE_OPERAND (arg1, 0))),
7429 TREE_OPERAND (arg1, 1)));
7431 /* Convert C1/(X*C2) into (C1/C2)/X. */
7432 if (flag_unsafe_math_optimizations
7433 && TREE_CODE (arg1) == MULT_EXPR
7434 && TREE_CODE (arg0) == REAL_CST
7435 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
7437 tree tem = const_binop (RDIV_EXPR, arg0,
7438 TREE_OPERAND (arg1, 1), 0);
7440 return fold (build2 (RDIV_EXPR, type, tem,
7441 TREE_OPERAND (arg1, 0)));
7444 if (flag_unsafe_math_optimizations)
7446 enum built_in_function fcode = builtin_mathfn_code (arg1);
7447 /* Optimize x/expN(y) into x*expN(-y). */
7448 if (BUILTIN_EXPONENT_P (fcode))
7450 tree expfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
7451 tree arg = negate_expr (TREE_VALUE (TREE_OPERAND (arg1, 1)));
7452 tree arglist = build_tree_list (NULL_TREE,
7453 fold_convert (type, arg));
7454 arg1 = build_function_call_expr (expfn, arglist);
7455 return fold (build2 (MULT_EXPR, type, arg0, arg1));
7458 /* Optimize x/pow(y,z) into x*pow(y,-z). */
7459 if (fcode == BUILT_IN_POW
7460 || fcode == BUILT_IN_POWF
7461 || fcode == BUILT_IN_POWL)
7463 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
7464 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
7465 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1, 1)));
7466 tree neg11 = fold_convert (type, negate_expr (arg11));
7467 tree arglist = tree_cons(NULL_TREE, arg10,
7468 build_tree_list (NULL_TREE, neg11));
7469 arg1 = build_function_call_expr (powfn, arglist);
7470 return fold (build2 (MULT_EXPR, type, arg0, arg1));
7474 if (flag_unsafe_math_optimizations)
7476 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
7477 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
7479 /* Optimize sin(x)/cos(x) as tan(x). */
7480 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_COS)
7481 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_COSF)
7482 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_COSL))
7483 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
7484 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
7486 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
7488 if (tanfn != NULL_TREE)
7489 return build_function_call_expr (tanfn,
7490 TREE_OPERAND (arg0, 1));
7493 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
7494 if (((fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_SIN)
7495 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_SINF)
7496 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_SINL))
7497 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
7498 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
7500 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
7502 if (tanfn != NULL_TREE)
7504 tree tmp = TREE_OPERAND (arg0, 1);
7505 tmp = build_function_call_expr (tanfn, tmp);
7506 return fold (build2 (RDIV_EXPR, type,
7507 build_real (type, dconst1), tmp));
7511 /* Optimize pow(x,c)/x as pow(x,c-1). */
7512 if (fcode0 == BUILT_IN_POW
7513 || fcode0 == BUILT_IN_POWF
7514 || fcode0 == BUILT_IN_POWL)
7516 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
7517 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0, 1)));
7518 if (TREE_CODE (arg01) == REAL_CST
7519 && ! TREE_CONSTANT_OVERFLOW (arg01)
7520 && operand_equal_p (arg1, arg00, 0))
7522 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7526 c = TREE_REAL_CST (arg01);
7527 real_arithmetic (&c, MINUS_EXPR, &c, &dconst1);
7528 arg = build_real (type, c);
7529 arglist = build_tree_list (NULL_TREE, arg);
7530 arglist = tree_cons (NULL_TREE, arg1, arglist);
7531 return build_function_call_expr (powfn, arglist);
7537 case TRUNC_DIV_EXPR:
7538 case ROUND_DIV_EXPR:
7539 case FLOOR_DIV_EXPR:
7541 case EXACT_DIV_EXPR:
7542 if (integer_onep (arg1))
7543 return non_lvalue (fold_convert (type, arg0));
7544 if (integer_zerop (arg1))
7547 if (!TYPE_UNSIGNED (type)
7548 && TREE_CODE (arg1) == INTEGER_CST
7549 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
7550 && TREE_INT_CST_HIGH (arg1) == -1)
7551 return fold_convert (type, negate_expr (arg0));
7553 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
7554 operation, EXACT_DIV_EXPR.
7556 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
7557 At one time others generated faster code, it's not clear if they do
7558 after the last round to changes to the DIV code in expmed.c. */
7559 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
7560 && multiple_of_p (type, arg0, arg1))
7561 return fold (build2 (EXACT_DIV_EXPR, type, arg0, arg1));
7563 if (TREE_CODE (arg1) == INTEGER_CST
7564 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
7566 return fold_convert (type, tem);
7571 case FLOOR_MOD_EXPR:
7572 case ROUND_MOD_EXPR:
7573 case TRUNC_MOD_EXPR:
7574 if (integer_onep (arg1))
7575 return omit_one_operand (type, integer_zero_node, arg0);
7576 if (integer_zerop (arg1))
7579 /* X % -1 is zero. */
7580 if (!TYPE_UNSIGNED (type)
7581 && TREE_CODE (arg1) == INTEGER_CST
7582 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
7583 && TREE_INT_CST_HIGH (arg1) == -1)
7584 return omit_one_operand (type, integer_zero_node, arg0);
7586 /* Optimize unsigned TRUNC_MOD_EXPR by a power of two into a
7587 BIT_AND_EXPR, i.e. "X % C" into "X & C2". */
7588 if (code == TRUNC_MOD_EXPR
7589 && TYPE_UNSIGNED (type)
7590 && integer_pow2p (arg1))
7592 unsigned HOST_WIDE_INT high, low;
7596 l = tree_log2 (arg1);
7597 if (l >= HOST_BITS_PER_WIDE_INT)
7599 high = ((unsigned HOST_WIDE_INT) 1
7600 << (l - HOST_BITS_PER_WIDE_INT)) - 1;
7606 low = ((unsigned HOST_WIDE_INT) 1 << l) - 1;
7609 mask = build_int_2 (low, high);
7610 TREE_TYPE (mask) = type;
7611 return fold (build2 (BIT_AND_EXPR, type,
7612 fold_convert (type, arg0), mask));
7615 /* X % -C is the same as X % C (for all rounding moduli). */
7616 if (!TYPE_UNSIGNED (type)
7617 && TREE_CODE (arg1) == INTEGER_CST
7618 && TREE_INT_CST_HIGH (arg1) < 0
7620 /* Avoid this transformation if C is INT_MIN, i.e. C == -C. */
7621 && !sign_bit_p (arg1, arg1))
7622 return fold (build2 (code, type, fold_convert (type, arg0),
7623 fold_convert (type, negate_expr (arg1))));
7625 /* X % -Y is the same as X % Y (for all rounding moduli). */
7626 if (!TYPE_UNSIGNED (type)
7627 && TREE_CODE (arg1) == NEGATE_EXPR
7629 return fold (build2 (code, type, fold_convert (type, arg0),
7630 fold_convert (type, TREE_OPERAND (arg1, 0))));
7632 if (TREE_CODE (arg1) == INTEGER_CST
7633 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
7635 return fold_convert (type, tem);
7641 if (integer_all_onesp (arg0))
7642 return omit_one_operand (type, arg0, arg1);
7646 /* Optimize -1 >> x for arithmetic right shifts. */
7647 if (integer_all_onesp (arg0) && !TYPE_UNSIGNED (type))
7648 return omit_one_operand (type, arg0, arg1);
7649 /* ... fall through ... */
7653 if (integer_zerop (arg1))
7654 return non_lvalue (fold_convert (type, arg0));
7655 if (integer_zerop (arg0))
7656 return omit_one_operand (type, arg0, arg1);
7658 /* Since negative shift count is not well-defined,
7659 don't try to compute it in the compiler. */
7660 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
7662 /* Rewrite an LROTATE_EXPR by a constant into an
7663 RROTATE_EXPR by a new constant. */
7664 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
7666 tree tem = build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type)), 0);
7667 tem = fold_convert (TREE_TYPE (arg1), tem);
7668 tem = const_binop (MINUS_EXPR, tem, arg1, 0);
7669 return fold (build2 (RROTATE_EXPR, type, arg0, tem));
7672 /* If we have a rotate of a bit operation with the rotate count and
7673 the second operand of the bit operation both constant,
7674 permute the two operations. */
7675 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
7676 && (TREE_CODE (arg0) == BIT_AND_EXPR
7677 || TREE_CODE (arg0) == BIT_IOR_EXPR
7678 || TREE_CODE (arg0) == BIT_XOR_EXPR)
7679 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
7680 return fold (build2 (TREE_CODE (arg0), type,
7681 fold (build2 (code, type,
7682 TREE_OPERAND (arg0, 0), arg1)),
7683 fold (build2 (code, type,
7684 TREE_OPERAND (arg0, 1), arg1))));
7686 /* Two consecutive rotates adding up to the width of the mode can
7688 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
7689 && TREE_CODE (arg0) == RROTATE_EXPR
7690 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7691 && TREE_INT_CST_HIGH (arg1) == 0
7692 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
7693 && ((TREE_INT_CST_LOW (arg1)
7694 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
7695 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type))))
7696 return TREE_OPERAND (arg0, 0);
7701 if (operand_equal_p (arg0, arg1, 0))
7702 return omit_one_operand (type, arg0, arg1);
7703 if (INTEGRAL_TYPE_P (type)
7704 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
7705 return omit_one_operand (type, arg1, arg0);
7709 if (operand_equal_p (arg0, arg1, 0))
7710 return omit_one_operand (type, arg0, arg1);
7711 if (INTEGRAL_TYPE_P (type)
7712 && TYPE_MAX_VALUE (type)
7713 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
7714 return omit_one_operand (type, arg1, arg0);
7717 case TRUTH_NOT_EXPR:
7718 /* The argument to invert_truthvalue must have Boolean type. */
7719 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
7720 arg0 = fold_convert (boolean_type_node, arg0);
7722 /* Note that the operand of this must be an int
7723 and its values must be 0 or 1.
7724 ("true" is a fixed value perhaps depending on the language,
7725 but we don't handle values other than 1 correctly yet.) */
7726 tem = invert_truthvalue (arg0);
7727 /* Avoid infinite recursion. */
7728 if (TREE_CODE (tem) == TRUTH_NOT_EXPR)
7730 tem = fold_single_bit_test (code, arg0, arg1, type);
7735 return fold_convert (type, tem);
7737 case TRUTH_ANDIF_EXPR:
7738 /* Note that the operands of this must be ints
7739 and their values must be 0 or 1.
7740 ("true" is a fixed value perhaps depending on the language.) */
7741 /* If first arg is constant zero, return it. */
7742 if (integer_zerop (arg0))
7743 return fold_convert (type, arg0);
7744 case TRUTH_AND_EXPR:
7745 /* If either arg is constant true, drop it. */
7746 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
7747 return non_lvalue (fold_convert (type, arg1));
7748 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
7749 /* Preserve sequence points. */
7750 && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
7751 return non_lvalue (fold_convert (type, arg0));
7752 /* If second arg is constant zero, result is zero, but first arg
7753 must be evaluated. */
7754 if (integer_zerop (arg1))
7755 return omit_one_operand (type, arg1, arg0);
7756 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
7757 case will be handled here. */
7758 if (integer_zerop (arg0))
7759 return omit_one_operand (type, arg0, arg1);
7761 /* !X && X is always false. */
7762 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
7763 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
7764 return omit_one_operand (type, integer_zero_node, arg1);
7765 /* X && !X is always false. */
7766 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
7767 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
7768 return omit_one_operand (type, integer_zero_node, arg0);
7771 /* We only do these simplifications if we are optimizing. */
7775 /* Check for things like (A || B) && (A || C). We can convert this
7776 to A || (B && C). Note that either operator can be any of the four
7777 truth and/or operations and the transformation will still be
7778 valid. Also note that we only care about order for the
7779 ANDIF and ORIF operators. If B contains side effects, this
7780 might change the truth-value of A. */
7781 if (TREE_CODE (arg0) == TREE_CODE (arg1)
7782 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
7783 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
7784 || TREE_CODE (arg0) == TRUTH_AND_EXPR
7785 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
7786 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
7788 tree a00 = TREE_OPERAND (arg0, 0);
7789 tree a01 = TREE_OPERAND (arg0, 1);
7790 tree a10 = TREE_OPERAND (arg1, 0);
7791 tree a11 = TREE_OPERAND (arg1, 1);
7792 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
7793 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
7794 && (code == TRUTH_AND_EXPR
7795 || code == TRUTH_OR_EXPR));
7797 if (operand_equal_p (a00, a10, 0))
7798 return fold (build2 (TREE_CODE (arg0), type, a00,
7799 fold (build2 (code, type, a01, a11))));
7800 else if (commutative && operand_equal_p (a00, a11, 0))
7801 return fold (build2 (TREE_CODE (arg0), type, a00,
7802 fold (build2 (code, type, a01, a10))));
7803 else if (commutative && operand_equal_p (a01, a10, 0))
7804 return fold (build2 (TREE_CODE (arg0), type, a01,
7805 fold (build2 (code, type, a00, a11))));
7807 /* This case if tricky because we must either have commutative
7808 operators or else A10 must not have side-effects. */
7810 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
7811 && operand_equal_p (a01, a11, 0))
7812 return fold (build2 (TREE_CODE (arg0), type,
7813 fold (build2 (code, type, a00, a10)),
7817 /* See if we can build a range comparison. */
7818 if (0 != (tem = fold_range_test (t)))
7821 /* Check for the possibility of merging component references. If our
7822 lhs is another similar operation, try to merge its rhs with our
7823 rhs. Then try to merge our lhs and rhs. */
7824 if (TREE_CODE (arg0) == code
7825 && 0 != (tem = fold_truthop (code, type,
7826 TREE_OPERAND (arg0, 1), arg1)))
7827 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), tem));
7829 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
7834 case TRUTH_ORIF_EXPR:
7835 /* Note that the operands of this must be ints
7836 and their values must be 0 or true.
7837 ("true" is a fixed value perhaps depending on the language.) */
7838 /* If first arg is constant true, return it. */
7839 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
7840 return fold_convert (type, arg0);
7842 /* If either arg is constant zero, drop it. */
7843 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
7844 return non_lvalue (fold_convert (type, arg1));
7845 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
7846 /* Preserve sequence points. */
7847 && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
7848 return non_lvalue (fold_convert (type, arg0));
7849 /* If second arg is constant true, result is true, but we must
7850 evaluate first arg. */
7851 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
7852 return omit_one_operand (type, arg1, arg0);
7853 /* Likewise for first arg, but note this only occurs here for
7855 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
7856 return omit_one_operand (type, arg0, arg1);
7858 /* !X || X is always true. */
7859 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
7860 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
7861 return omit_one_operand (type, integer_one_node, arg1);
7862 /* X || !X is always true. */
7863 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
7864 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
7865 return omit_one_operand (type, integer_one_node, arg0);
7869 case TRUTH_XOR_EXPR:
7870 /* If the second arg is constant zero, drop it. */
7871 if (integer_zerop (arg1))
7872 return non_lvalue (fold_convert (type, arg0));
7873 /* If the second arg is constant true, this is a logical inversion. */
7874 if (integer_onep (arg1))
7875 return non_lvalue (fold_convert (type, invert_truthvalue (arg0)));
7876 /* Identical arguments cancel to zero. */
7877 if (operand_equal_p (arg0, arg1, 0))
7878 return omit_one_operand (type, integer_zero_node, arg0);
7880 /* !X ^ X is always true. */
7881 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
7882 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
7883 return omit_one_operand (type, integer_one_node, arg1);
7885 /* X ^ !X is always true. */
7886 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
7887 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
7888 return omit_one_operand (type, integer_one_node, arg0);
7898 /* If one arg is a real or integer constant, put it last. */
7899 if (tree_swap_operands_p (arg0, arg1, true))
7900 return fold (build2 (swap_tree_comparison (code), type, arg1, arg0));
7902 /* If this is an equality comparison of the address of a non-weak
7903 object against zero, then we know the result. */
7904 if ((code == EQ_EXPR || code == NE_EXPR)
7905 && TREE_CODE (arg0) == ADDR_EXPR
7906 && DECL_P (TREE_OPERAND (arg0, 0))
7907 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
7908 && integer_zerop (arg1))
7909 return constant_boolean_node (code != EQ_EXPR, type);
7911 /* If this is an equality comparison of the address of two non-weak,
7912 unaliased symbols neither of which are extern (since we do not
7913 have access to attributes for externs), then we know the result. */
7914 if ((code == EQ_EXPR || code == NE_EXPR)
7915 && TREE_CODE (arg0) == ADDR_EXPR
7916 && DECL_P (TREE_OPERAND (arg0, 0))
7917 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
7918 && ! lookup_attribute ("alias",
7919 DECL_ATTRIBUTES (TREE_OPERAND (arg0, 0)))
7920 && ! DECL_EXTERNAL (TREE_OPERAND (arg0, 0))
7921 && TREE_CODE (arg1) == ADDR_EXPR
7922 && DECL_P (TREE_OPERAND (arg1, 0))
7923 && ! DECL_WEAK (TREE_OPERAND (arg1, 0))
7924 && ! lookup_attribute ("alias",
7925 DECL_ATTRIBUTES (TREE_OPERAND (arg1, 0)))
7926 && ! DECL_EXTERNAL (TREE_OPERAND (arg1, 0)))
7927 return constant_boolean_node (operand_equal_p (arg0, arg1, 0)
7928 ? code == EQ_EXPR : code != EQ_EXPR,
7931 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
7933 tree targ0 = strip_float_extensions (arg0);
7934 tree targ1 = strip_float_extensions (arg1);
7935 tree newtype = TREE_TYPE (targ0);
7937 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
7938 newtype = TREE_TYPE (targ1);
7940 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
7941 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
7942 return fold (build2 (code, type, fold_convert (newtype, targ0),
7943 fold_convert (newtype, targ1)));
7945 /* (-a) CMP (-b) -> b CMP a */
7946 if (TREE_CODE (arg0) == NEGATE_EXPR
7947 && TREE_CODE (arg1) == NEGATE_EXPR)
7948 return fold (build2 (code, type, TREE_OPERAND (arg1, 0),
7949 TREE_OPERAND (arg0, 0)));
7951 if (TREE_CODE (arg1) == REAL_CST)
7953 REAL_VALUE_TYPE cst;
7954 cst = TREE_REAL_CST (arg1);
7956 /* (-a) CMP CST -> a swap(CMP) (-CST) */
7957 if (TREE_CODE (arg0) == NEGATE_EXPR)
7959 fold (build2 (swap_tree_comparison (code), type,
7960 TREE_OPERAND (arg0, 0),
7961 build_real (TREE_TYPE (arg1),
7962 REAL_VALUE_NEGATE (cst))));
7964 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
7965 /* a CMP (-0) -> a CMP 0 */
7966 if (REAL_VALUE_MINUS_ZERO (cst))
7967 return fold (build2 (code, type, arg0,
7968 build_real (TREE_TYPE (arg1), dconst0)));
7970 /* x != NaN is always true, other ops are always false. */
7971 if (REAL_VALUE_ISNAN (cst)
7972 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))))
7974 tem = (code == NE_EXPR) ? integer_one_node : integer_zero_node;
7975 return omit_one_operand (type, tem, arg0);
7978 /* Fold comparisons against infinity. */
7979 if (REAL_VALUE_ISINF (cst))
7981 tem = fold_inf_compare (code, type, arg0, arg1);
7982 if (tem != NULL_TREE)
7987 /* If this is a comparison of a real constant with a PLUS_EXPR
7988 or a MINUS_EXPR of a real constant, we can convert it into a
7989 comparison with a revised real constant as long as no overflow
7990 occurs when unsafe_math_optimizations are enabled. */
7991 if (flag_unsafe_math_optimizations
7992 && TREE_CODE (arg1) == REAL_CST
7993 && (TREE_CODE (arg0) == PLUS_EXPR
7994 || TREE_CODE (arg0) == MINUS_EXPR)
7995 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
7996 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
7997 ? MINUS_EXPR : PLUS_EXPR,
7998 arg1, TREE_OPERAND (arg0, 1), 0))
7999 && ! TREE_CONSTANT_OVERFLOW (tem))
8000 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), tem));
8002 /* Likewise, we can simplify a comparison of a real constant with
8003 a MINUS_EXPR whose first operand is also a real constant, i.e.
8004 (c1 - x) < c2 becomes x > c1-c2. */
8005 if (flag_unsafe_math_optimizations
8006 && TREE_CODE (arg1) == REAL_CST
8007 && TREE_CODE (arg0) == MINUS_EXPR
8008 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST
8009 && 0 != (tem = const_binop (MINUS_EXPR, TREE_OPERAND (arg0, 0),
8011 && ! TREE_CONSTANT_OVERFLOW (tem))
8012 return fold (build2 (swap_tree_comparison (code), type,
8013 TREE_OPERAND (arg0, 1), tem));
8015 /* Fold comparisons against built-in math functions. */
8016 if (TREE_CODE (arg1) == REAL_CST
8017 && flag_unsafe_math_optimizations
8018 && ! flag_errno_math)
8020 enum built_in_function fcode = builtin_mathfn_code (arg0);
8022 if (fcode != END_BUILTINS)
8024 tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
8025 if (tem != NULL_TREE)
8031 /* Convert foo++ == CONST into ++foo == CONST + INCR. */
8032 if (TREE_CONSTANT (arg1)
8033 && (TREE_CODE (arg0) == POSTINCREMENT_EXPR
8034 || TREE_CODE (arg0) == POSTDECREMENT_EXPR)
8035 /* This optimization is invalid for ordered comparisons
8036 if CONST+INCR overflows or if foo+incr might overflow.
8037 This optimization is invalid for floating point due to rounding.
8038 For pointer types we assume overflow doesn't happen. */
8039 && (POINTER_TYPE_P (TREE_TYPE (arg0))
8040 || (INTEGRAL_TYPE_P (TREE_TYPE (arg0))
8041 && (code == EQ_EXPR || code == NE_EXPR))))
8043 tree varop, newconst;
8045 if (TREE_CODE (arg0) == POSTINCREMENT_EXPR)
8047 newconst = fold (build2 (PLUS_EXPR, TREE_TYPE (arg0),
8048 arg1, TREE_OPERAND (arg0, 1)));
8049 varop = build2 (PREINCREMENT_EXPR, TREE_TYPE (arg0),
8050 TREE_OPERAND (arg0, 0),
8051 TREE_OPERAND (arg0, 1));
8055 newconst = fold (build2 (MINUS_EXPR, TREE_TYPE (arg0),
8056 arg1, TREE_OPERAND (arg0, 1)));
8057 varop = build2 (PREDECREMENT_EXPR, TREE_TYPE (arg0),
8058 TREE_OPERAND (arg0, 0),
8059 TREE_OPERAND (arg0, 1));
8063 /* If VAROP is a reference to a bitfield, we must mask
8064 the constant by the width of the field. */
8065 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
8066 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (varop, 0), 1))
8067 && host_integerp (DECL_SIZE (TREE_OPERAND
8068 (TREE_OPERAND (varop, 0), 1)), 1))
8070 tree fielddecl = TREE_OPERAND (TREE_OPERAND (varop, 0), 1);
8071 HOST_WIDE_INT size = tree_low_cst (DECL_SIZE (fielddecl), 1);
8072 tree folded_compare, shift;
8074 /* First check whether the comparison would come out
8075 always the same. If we don't do that we would
8076 change the meaning with the masking. */
8077 folded_compare = fold (build2 (code, type,
8078 TREE_OPERAND (varop, 0), arg1));
8079 if (integer_zerop (folded_compare)
8080 || integer_onep (folded_compare))
8081 return omit_one_operand (type, folded_compare, varop);
8083 shift = build_int_2 (TYPE_PRECISION (TREE_TYPE (varop)) - size,
8085 shift = fold_convert (TREE_TYPE (varop), shift);
8086 newconst = fold (build2 (LSHIFT_EXPR, TREE_TYPE (varop),
8088 newconst = fold (build2 (RSHIFT_EXPR, TREE_TYPE (varop),
8092 return fold (build2 (code, type, varop, newconst));
8095 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
8096 This transformation affects the cases which are handled in later
8097 optimizations involving comparisons with non-negative constants. */
8098 if (TREE_CODE (arg1) == INTEGER_CST
8099 && TREE_CODE (arg0) != INTEGER_CST
8100 && tree_int_cst_sgn (arg1) > 0)
8105 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
8106 return fold (build2 (GT_EXPR, type, arg0, arg1));
8109 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
8110 return fold (build2 (LE_EXPR, type, arg0, arg1));
8117 /* Comparisons with the highest or lowest possible integer of
8118 the specified size will have known values.
8120 This is quite similar to fold_relational_hi_lo; however, my
8121 attempts to share the code have been nothing but trouble.
8122 I give up for now. */
8124 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1)));
8126 if (TREE_CODE (arg1) == INTEGER_CST
8127 && ! TREE_CONSTANT_OVERFLOW (arg1)
8128 && width <= HOST_BITS_PER_WIDE_INT
8129 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
8130 || POINTER_TYPE_P (TREE_TYPE (arg1))))
8132 unsigned HOST_WIDE_INT signed_max;
8133 unsigned HOST_WIDE_INT max, min;
8135 signed_max = ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1;
8137 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
8139 max = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
8145 min = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
8148 if (TREE_INT_CST_HIGH (arg1) == 0
8149 && TREE_INT_CST_LOW (arg1) == max)
8153 return omit_one_operand (type, integer_zero_node, arg0);
8156 return fold (build2 (EQ_EXPR, type, arg0, arg1));
8159 return omit_one_operand (type, integer_one_node, arg0);
8162 return fold (build2 (NE_EXPR, type, arg0, arg1));
8164 /* The GE_EXPR and LT_EXPR cases above are not normally
8165 reached because of previous transformations. */
8170 else if (TREE_INT_CST_HIGH (arg1) == 0
8171 && TREE_INT_CST_LOW (arg1) == max - 1)
8175 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
8176 return fold (build2 (EQ_EXPR, type, arg0, arg1));
8178 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
8179 return fold (build2 (NE_EXPR, type, arg0, arg1));
8183 else if (TREE_INT_CST_HIGH (arg1) == (min ? -1 : 0)
8184 && TREE_INT_CST_LOW (arg1) == min)
8188 return omit_one_operand (type, integer_zero_node, arg0);
8191 return fold (build2 (EQ_EXPR, type, arg0, arg1));
8194 return omit_one_operand (type, integer_one_node, arg0);
8197 return fold (build2 (NE_EXPR, type, arg0, arg1));
8202 else if (TREE_INT_CST_HIGH (arg1) == (min ? -1 : 0)
8203 && TREE_INT_CST_LOW (arg1) == min + 1)
8207 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
8208 return fold (build2 (NE_EXPR, type, arg0, arg1));
8210 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
8211 return fold (build2 (EQ_EXPR, type, arg0, arg1));
8216 else if (!in_gimple_form
8217 && TREE_INT_CST_HIGH (arg1) == 0
8218 && TREE_INT_CST_LOW (arg1) == signed_max
8219 && TYPE_UNSIGNED (TREE_TYPE (arg1))
8220 /* signed_type does not work on pointer types. */
8221 && INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
8223 /* The following case also applies to X < signed_max+1
8224 and X >= signed_max+1 because previous transformations. */
8225 if (code == LE_EXPR || code == GT_EXPR)
8228 st0 = lang_hooks.types.signed_type (TREE_TYPE (arg0));
8229 st1 = lang_hooks.types.signed_type (TREE_TYPE (arg1));
8231 (build2 (code == LE_EXPR ? GE_EXPR: LT_EXPR,
8232 type, fold_convert (st0, arg0),
8233 fold_convert (st1, integer_zero_node)));
8239 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
8240 a MINUS_EXPR of a constant, we can convert it into a comparison with
8241 a revised constant as long as no overflow occurs. */
8242 if ((code == EQ_EXPR || code == NE_EXPR)
8243 && TREE_CODE (arg1) == INTEGER_CST
8244 && (TREE_CODE (arg0) == PLUS_EXPR
8245 || TREE_CODE (arg0) == MINUS_EXPR)
8246 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8247 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
8248 ? MINUS_EXPR : PLUS_EXPR,
8249 arg1, TREE_OPERAND (arg0, 1), 0))
8250 && ! TREE_CONSTANT_OVERFLOW (tem))
8251 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), tem));
8253 /* Similarly for a NEGATE_EXPR. */
8254 else if ((code == EQ_EXPR || code == NE_EXPR)
8255 && TREE_CODE (arg0) == NEGATE_EXPR
8256 && TREE_CODE (arg1) == INTEGER_CST
8257 && 0 != (tem = negate_expr (arg1))
8258 && TREE_CODE (tem) == INTEGER_CST
8259 && ! TREE_CONSTANT_OVERFLOW (tem))
8260 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), tem));
8262 /* If we have X - Y == 0, we can convert that to X == Y and similarly
8263 for !=. Don't do this for ordered comparisons due to overflow. */
8264 else if ((code == NE_EXPR || code == EQ_EXPR)
8265 && integer_zerop (arg1) && TREE_CODE (arg0) == MINUS_EXPR)
8266 return fold (build2 (code, type,
8267 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1)));
8269 /* If we are widening one operand of an integer comparison,
8270 see if the other operand is similarly being widened. Perhaps we
8271 can do the comparison in the narrower type. */
8272 else if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
8273 && TREE_CODE (arg0) == NOP_EXPR
8274 && (tem = get_unwidened (arg0, NULL_TREE)) != arg0
8275 && (code == EQ_EXPR || code == NE_EXPR
8276 || TYPE_UNSIGNED (TREE_TYPE (arg0))
8277 == TYPE_UNSIGNED (TREE_TYPE (tem)))
8278 && (t1 = get_unwidened (arg1, TREE_TYPE (tem))) != 0
8279 && (TREE_TYPE (t1) == TREE_TYPE (tem)
8280 || (TREE_CODE (t1) == INTEGER_CST
8281 && int_fits_type_p (t1, TREE_TYPE (tem)))))
8282 return fold (build2 (code, type, tem,
8283 fold_convert (TREE_TYPE (tem), t1)));
8285 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
8286 constant, we can simplify it. */
8287 else if (TREE_CODE (arg1) == INTEGER_CST
8288 && (TREE_CODE (arg0) == MIN_EXPR
8289 || TREE_CODE (arg0) == MAX_EXPR)
8290 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8291 return optimize_minmax_comparison (t);
8293 /* If we are comparing an ABS_EXPR with a constant, we can
8294 convert all the cases into explicit comparisons, but they may
8295 well not be faster than doing the ABS and one comparison.
8296 But ABS (X) <= C is a range comparison, which becomes a subtraction
8297 and a comparison, and is probably faster. */
8298 else if (code == LE_EXPR && TREE_CODE (arg1) == INTEGER_CST
8299 && TREE_CODE (arg0) == ABS_EXPR
8300 && ! TREE_SIDE_EFFECTS (arg0)
8301 && (0 != (tem = negate_expr (arg1)))
8302 && TREE_CODE (tem) == INTEGER_CST
8303 && ! TREE_CONSTANT_OVERFLOW (tem))
8304 return fold (build2 (TRUTH_ANDIF_EXPR, type,
8305 build2 (GE_EXPR, type,
8306 TREE_OPERAND (arg0, 0), tem),
8307 build2 (LE_EXPR, type,
8308 TREE_OPERAND (arg0, 0), arg1)));
8310 /* If this is an EQ or NE comparison with zero and ARG0 is
8311 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
8312 two operations, but the latter can be done in one less insn
8313 on machines that have only two-operand insns or on which a
8314 constant cannot be the first operand. */
8315 if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR)
8316 && TREE_CODE (arg0) == BIT_AND_EXPR)
8318 tree arg00 = TREE_OPERAND (arg0, 0);
8319 tree arg01 = TREE_OPERAND (arg0, 1);
8320 if (TREE_CODE (arg00) == LSHIFT_EXPR
8321 && integer_onep (TREE_OPERAND (arg00, 0)))
8323 fold (build2 (code, type,
8324 build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
8325 build2 (RSHIFT_EXPR, TREE_TYPE (arg00),
8326 arg01, TREE_OPERAND (arg00, 1)),
8327 fold_convert (TREE_TYPE (arg0),
8330 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
8331 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
8333 fold (build2 (code, type,
8334 build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
8335 build2 (RSHIFT_EXPR, TREE_TYPE (arg01),
8336 arg00, TREE_OPERAND (arg01, 1)),
8337 fold_convert (TREE_TYPE (arg0),
8342 /* If this is an NE or EQ comparison of zero against the result of a
8343 signed MOD operation whose second operand is a power of 2, make
8344 the MOD operation unsigned since it is simpler and equivalent. */
8345 if ((code == NE_EXPR || code == EQ_EXPR)
8346 && integer_zerop (arg1)
8347 && !TYPE_UNSIGNED (TREE_TYPE (arg0))
8348 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
8349 || TREE_CODE (arg0) == CEIL_MOD_EXPR
8350 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
8351 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
8352 && integer_pow2p (TREE_OPERAND (arg0, 1)))
8354 tree newtype = lang_hooks.types.unsigned_type (TREE_TYPE (arg0));
8355 tree newmod = fold (build2 (TREE_CODE (arg0), newtype,
8356 fold_convert (newtype,
8357 TREE_OPERAND (arg0, 0)),
8358 fold_convert (newtype,
8359 TREE_OPERAND (arg0, 1))));
8361 return fold (build2 (code, type, newmod,
8362 fold_convert (newtype, arg1)));
8365 /* If this is an NE comparison of zero with an AND of one, remove the
8366 comparison since the AND will give the correct value. */
8367 if (code == NE_EXPR && integer_zerop (arg1)
8368 && TREE_CODE (arg0) == BIT_AND_EXPR
8369 && integer_onep (TREE_OPERAND (arg0, 1)))
8370 return fold_convert (type, arg0);
8372 /* If we have (A & C) == C where C is a power of 2, convert this into
8373 (A & C) != 0. Similarly for NE_EXPR. */
8374 if ((code == EQ_EXPR || code == NE_EXPR)
8375 && TREE_CODE (arg0) == BIT_AND_EXPR
8376 && integer_pow2p (TREE_OPERAND (arg0, 1))
8377 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
8378 return fold (build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
8379 arg0, integer_zero_node));
8381 /* If we have (A & C) != 0 or (A & C) == 0 and C is a power of
8382 2, then fold the expression into shifts and logical operations. */
8383 tem = fold_single_bit_test (code, arg0, arg1, type);
8387 /* If we have (A & C) == D where D & ~C != 0, convert this into 0.
8388 Similarly for NE_EXPR. */
8389 if ((code == EQ_EXPR || code == NE_EXPR)
8390 && TREE_CODE (arg0) == BIT_AND_EXPR
8391 && TREE_CODE (arg1) == INTEGER_CST
8392 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8395 = fold (build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
8396 arg1, build1 (BIT_NOT_EXPR,
8397 TREE_TYPE (TREE_OPERAND (arg0, 1)),
8398 TREE_OPERAND (arg0, 1))));
8399 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
8400 if (integer_nonzerop (dandnotc))
8401 return omit_one_operand (type, rslt, arg0);
8404 /* If we have (A | C) == D where C & ~D != 0, convert this into 0.
8405 Similarly for NE_EXPR. */
8406 if ((code == EQ_EXPR || code == NE_EXPR)
8407 && TREE_CODE (arg0) == BIT_IOR_EXPR
8408 && TREE_CODE (arg1) == INTEGER_CST
8409 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8412 = fold (build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
8413 TREE_OPERAND (arg0, 1),
8414 build1 (BIT_NOT_EXPR, TREE_TYPE (arg1), arg1)));
8415 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
8416 if (integer_nonzerop (candnotd))
8417 return omit_one_operand (type, rslt, arg0);
8420 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
8421 and similarly for >= into !=. */
8422 if ((code == LT_EXPR || code == GE_EXPR)
8423 && TYPE_UNSIGNED (TREE_TYPE (arg0))
8424 && TREE_CODE (arg1) == LSHIFT_EXPR
8425 && integer_onep (TREE_OPERAND (arg1, 0)))
8426 return build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
8427 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
8428 TREE_OPERAND (arg1, 1)),
8429 fold_convert (TREE_TYPE (arg0), integer_zero_node));
8431 else if ((code == LT_EXPR || code == GE_EXPR)
8432 && TYPE_UNSIGNED (TREE_TYPE (arg0))
8433 && (TREE_CODE (arg1) == NOP_EXPR
8434 || TREE_CODE (arg1) == CONVERT_EXPR)
8435 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
8436 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
8438 build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
8439 fold_convert (TREE_TYPE (arg0),
8440 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
8441 TREE_OPERAND (TREE_OPERAND (arg1, 0),
8443 fold_convert (TREE_TYPE (arg0), integer_zero_node));
8445 /* Simplify comparison of something with itself. (For IEEE
8446 floating-point, we can only do some of these simplifications.) */
8447 if (operand_equal_p (arg0, arg1, 0))
8452 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
8453 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8454 return constant_boolean_node (1, type);
8459 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
8460 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8461 return constant_boolean_node (1, type);
8462 return fold (build2 (EQ_EXPR, type, arg0, arg1));
8465 /* For NE, we can only do this simplification if integer
8466 or we don't honor IEEE floating point NaNs. */
8467 if (FLOAT_TYPE_P (TREE_TYPE (arg0))
8468 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8470 /* ... fall through ... */
8473 return constant_boolean_node (0, type);
8479 /* If we are comparing an expression that just has comparisons
8480 of two integer values, arithmetic expressions of those comparisons,
8481 and constants, we can simplify it. There are only three cases
8482 to check: the two values can either be equal, the first can be
8483 greater, or the second can be greater. Fold the expression for
8484 those three values. Since each value must be 0 or 1, we have
8485 eight possibilities, each of which corresponds to the constant 0
8486 or 1 or one of the six possible comparisons.
8488 This handles common cases like (a > b) == 0 but also handles
8489 expressions like ((x > y) - (y > x)) > 0, which supposedly
8490 occur in macroized code. */
8492 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
8494 tree cval1 = 0, cval2 = 0;
8497 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
8498 /* Don't handle degenerate cases here; they should already
8499 have been handled anyway. */
8500 && cval1 != 0 && cval2 != 0
8501 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
8502 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
8503 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
8504 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
8505 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
8506 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
8507 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
8509 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
8510 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
8512 /* We can't just pass T to eval_subst in case cval1 or cval2
8513 was the same as ARG1. */
8516 = fold (build2 (code, type,
8517 eval_subst (arg0, cval1, maxval,
8521 = fold (build2 (code, type,
8522 eval_subst (arg0, cval1, maxval,
8526 = fold (build2 (code, type,
8527 eval_subst (arg0, cval1, minval,
8531 /* All three of these results should be 0 or 1. Confirm they
8532 are. Then use those values to select the proper code
8535 if ((integer_zerop (high_result)
8536 || integer_onep (high_result))
8537 && (integer_zerop (equal_result)
8538 || integer_onep (equal_result))
8539 && (integer_zerop (low_result)
8540 || integer_onep (low_result)))
8542 /* Make a 3-bit mask with the high-order bit being the
8543 value for `>', the next for '=', and the low for '<'. */
8544 switch ((integer_onep (high_result) * 4)
8545 + (integer_onep (equal_result) * 2)
8546 + integer_onep (low_result))
8550 return omit_one_operand (type, integer_zero_node, arg0);
8571 return omit_one_operand (type, integer_one_node, arg0);
8574 tem = build2 (code, type, cval1, cval2);
8576 return save_expr (tem);
8583 /* If this is a comparison of a field, we may be able to simplify it. */
8584 if (((TREE_CODE (arg0) == COMPONENT_REF
8585 && lang_hooks.can_use_bit_fields_p ())
8586 || TREE_CODE (arg0) == BIT_FIELD_REF)
8587 && (code == EQ_EXPR || code == NE_EXPR)
8588 /* Handle the constant case even without -O
8589 to make sure the warnings are given. */
8590 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
8592 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
8597 /* If this is a comparison of complex values and either or both sides
8598 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
8599 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
8600 This may prevent needless evaluations. */
8601 if ((code == EQ_EXPR || code == NE_EXPR)
8602 && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
8603 && (TREE_CODE (arg0) == COMPLEX_EXPR
8604 || TREE_CODE (arg1) == COMPLEX_EXPR
8605 || TREE_CODE (arg0) == COMPLEX_CST
8606 || TREE_CODE (arg1) == COMPLEX_CST))
8608 tree subtype = TREE_TYPE (TREE_TYPE (arg0));
8609 tree real0, imag0, real1, imag1;
8611 arg0 = save_expr (arg0);
8612 arg1 = save_expr (arg1);
8613 real0 = fold (build1 (REALPART_EXPR, subtype, arg0));
8614 imag0 = fold (build1 (IMAGPART_EXPR, subtype, arg0));
8615 real1 = fold (build1 (REALPART_EXPR, subtype, arg1));
8616 imag1 = fold (build1 (IMAGPART_EXPR, subtype, arg1));
8618 return fold (build2 ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR
8621 fold (build2 (code, type, real0, real1)),
8622 fold (build2 (code, type, imag0, imag1))));
8625 /* Optimize comparisons of strlen vs zero to a compare of the
8626 first character of the string vs zero. To wit,
8627 strlen(ptr) == 0 => *ptr == 0
8628 strlen(ptr) != 0 => *ptr != 0
8629 Other cases should reduce to one of these two (or a constant)
8630 due to the return value of strlen being unsigned. */
8631 if ((code == EQ_EXPR || code == NE_EXPR)
8632 && integer_zerop (arg1)
8633 && TREE_CODE (arg0) == CALL_EXPR)
8635 tree fndecl = get_callee_fndecl (arg0);
8639 && DECL_BUILT_IN (fndecl)
8640 && DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_MD
8641 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
8642 && (arglist = TREE_OPERAND (arg0, 1))
8643 && TREE_CODE (TREE_TYPE (TREE_VALUE (arglist))) == POINTER_TYPE
8644 && ! TREE_CHAIN (arglist))
8645 return fold (build2 (code, type,
8646 build1 (INDIRECT_REF, char_type_node,
8647 TREE_VALUE(arglist)),
8648 integer_zero_node));
8651 /* We can fold X/C1 op C2 where C1 and C2 are integer constants
8652 into a single range test. */
8653 if (TREE_CODE (arg0) == TRUNC_DIV_EXPR
8654 && TREE_CODE (arg1) == INTEGER_CST
8655 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8656 && !integer_zerop (TREE_OPERAND (arg0, 1))
8657 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
8658 && !TREE_OVERFLOW (arg1))
8660 t1 = fold_div_compare (code, type, arg0, arg1);
8661 if (t1 != NULL_TREE)
8665 if ((code == EQ_EXPR || code == NE_EXPR)
8666 && !TREE_SIDE_EFFECTS (arg0)
8667 && integer_zerop (arg1)
8668 && tree_expr_nonzero_p (arg0))
8669 return constant_boolean_node (code==NE_EXPR, type);
8671 t1 = fold_relational_const (code, type, arg0, arg1);
8672 return t1 == NULL_TREE ? t : t1;
8674 case UNORDERED_EXPR:
8682 if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
8684 t1 = fold_relational_const (code, type, arg0, arg1);
8685 if (t1 != NULL_TREE)
8689 /* If the first operand is NaN, the result is constant. */
8690 if (TREE_CODE (arg0) == REAL_CST
8691 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
8692 && (code != LTGT_EXPR || ! flag_trapping_math))
8694 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
8697 return omit_one_operand (type, t1, arg1);
8700 /* If the second operand is NaN, the result is constant. */
8701 if (TREE_CODE (arg1) == REAL_CST
8702 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg1))
8703 && (code != LTGT_EXPR || ! flag_trapping_math))
8705 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
8708 return omit_one_operand (type, t1, arg0);
8711 /* Simplify unordered comparison of something with itself. */
8712 if ((code == UNLE_EXPR || code == UNGE_EXPR || code == UNEQ_EXPR)
8713 && operand_equal_p (arg0, arg1, 0))
8714 return constant_boolean_node (1, type);
8716 if (code == LTGT_EXPR
8717 && !flag_trapping_math
8718 && operand_equal_p (arg0, arg1, 0))
8719 return constant_boolean_node (0, type);
8721 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
8723 tree targ0 = strip_float_extensions (arg0);
8724 tree targ1 = strip_float_extensions (arg1);
8725 tree newtype = TREE_TYPE (targ0);
8727 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
8728 newtype = TREE_TYPE (targ1);
8730 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
8731 return fold (build2 (code, type, fold_convert (newtype, targ0),
8732 fold_convert (newtype, targ1)));
8738 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
8739 so all simple results must be passed through pedantic_non_lvalue. */
8740 if (TREE_CODE (arg0) == INTEGER_CST)
8742 tem = TREE_OPERAND (t, (integer_zerop (arg0) ? 2 : 1));
8743 /* Only optimize constant conditions when the selected branch
8744 has the same type as the COND_EXPR. This avoids optimizing
8745 away "c ? x : throw", where the throw has a void type. */
8746 if (! VOID_TYPE_P (TREE_TYPE (tem))
8747 || VOID_TYPE_P (type))
8748 return pedantic_non_lvalue (tem);
8751 if (operand_equal_p (arg1, TREE_OPERAND (t, 2), 0))
8752 return pedantic_omit_one_operand (type, arg1, arg0);
8754 /* If we have A op B ? A : C, we may be able to convert this to a
8755 simpler expression, depending on the operation and the values
8756 of B and C. Signed zeros prevent all of these transformations,
8757 for reasons given above each one.
8759 Also try swapping the arguments and inverting the conditional. */
8760 if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
8761 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
8762 arg1, TREE_OPERAND (arg0, 1))
8763 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
8765 tem = fold_cond_expr_with_comparison (type, arg0,
8766 TREE_OPERAND (t, 1),
8767 TREE_OPERAND (t, 2));
8772 if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
8773 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
8774 TREE_OPERAND (t, 2),
8775 TREE_OPERAND (arg0, 1))
8776 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (TREE_OPERAND (t, 2)))))
8778 tem = invert_truthvalue (arg0);
8779 if (TREE_CODE_CLASS (TREE_CODE (tem)) == '<')
8781 tem = fold_cond_expr_with_comparison (type, tem,
8782 TREE_OPERAND (t, 2),
8783 TREE_OPERAND (t, 1));
8789 /* If the second operand is simpler than the third, swap them
8790 since that produces better jump optimization results. */
8791 if (tree_swap_operands_p (TREE_OPERAND (t, 1),
8792 TREE_OPERAND (t, 2), false))
8794 /* See if this can be inverted. If it can't, possibly because
8795 it was a floating-point inequality comparison, don't do
8797 tem = invert_truthvalue (arg0);
8799 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
8800 return fold (build3 (code, type, tem,
8801 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1)));
8804 /* Convert A ? 1 : 0 to simply A. */
8805 if (integer_onep (TREE_OPERAND (t, 1))
8806 && integer_zerop (TREE_OPERAND (t, 2))
8807 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
8808 call to fold will try to move the conversion inside
8809 a COND, which will recurse. In that case, the COND_EXPR
8810 is probably the best choice, so leave it alone. */
8811 && type == TREE_TYPE (arg0))
8812 return pedantic_non_lvalue (arg0);
8814 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
8815 over COND_EXPR in cases such as floating point comparisons. */
8816 if (integer_zerop (TREE_OPERAND (t, 1))
8817 && integer_onep (TREE_OPERAND (t, 2))
8818 && truth_value_p (TREE_CODE (arg0)))
8819 return pedantic_non_lvalue (fold_convert (type,
8820 invert_truthvalue (arg0)));
8822 /* A < 0 ? <sign bit of A> : 0 is simply (A & <sign bit of A>). */
8823 if (TREE_CODE (arg0) == LT_EXPR
8824 && integer_zerop (TREE_OPERAND (arg0, 1))
8825 && integer_zerop (TREE_OPERAND (t, 2))
8826 && (tem = sign_bit_p (TREE_OPERAND (arg0, 0), arg1)))
8827 return fold_convert (type, fold (build2 (BIT_AND_EXPR,
8828 TREE_TYPE (tem), tem, arg1)));
8830 /* (A >> N) & 1 ? (1 << N) : 0 is simply A & (1 << N). A & 1 was
8831 already handled above. */
8832 if (TREE_CODE (arg0) == BIT_AND_EXPR
8833 && integer_onep (TREE_OPERAND (arg0, 1))
8834 && integer_zerop (TREE_OPERAND (t, 2))
8835 && integer_pow2p (arg1))
8837 tree tem = TREE_OPERAND (arg0, 0);
8839 if (TREE_CODE (tem) == RSHIFT_EXPR
8840 && (unsigned HOST_WIDE_INT) tree_log2 (arg1) ==
8841 TREE_INT_CST_LOW (TREE_OPERAND (tem, 1)))
8842 return fold (build2 (BIT_AND_EXPR, type,
8843 TREE_OPERAND (tem, 0), arg1));
8846 /* A & N ? N : 0 is simply A & N if N is a power of two. This
8847 is probably obsolete because the first operand should be a
8848 truth value (that's why we have the two cases above), but let's
8849 leave it in until we can confirm this for all front-ends. */
8850 if (integer_zerop (TREE_OPERAND (t, 2))
8851 && TREE_CODE (arg0) == NE_EXPR
8852 && integer_zerop (TREE_OPERAND (arg0, 1))
8853 && integer_pow2p (arg1)
8854 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
8855 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
8856 arg1, OEP_ONLY_CONST))
8857 return pedantic_non_lvalue (fold_convert (type,
8858 TREE_OPERAND (arg0, 0)));
8860 /* Convert A ? B : 0 into A && B if A and B are truth values. */
8861 if (integer_zerop (TREE_OPERAND (t, 2))
8862 && truth_value_p (TREE_CODE (arg0))
8863 && truth_value_p (TREE_CODE (arg1)))
8864 return fold (build2 (TRUTH_ANDIF_EXPR, type, arg0, arg1));
8866 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
8867 if (integer_onep (TREE_OPERAND (t, 2))
8868 && truth_value_p (TREE_CODE (arg0))
8869 && truth_value_p (TREE_CODE (arg1)))
8871 /* Only perform transformation if ARG0 is easily inverted. */
8872 tem = invert_truthvalue (arg0);
8873 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
8874 return fold (build2 (TRUTH_ORIF_EXPR, type, tem, arg1));
8877 /* Convert A ? 0 : B into !A && B if A and B are truth values. */
8878 if (integer_zerop (arg1)
8879 && truth_value_p (TREE_CODE (arg0))
8880 && truth_value_p (TREE_CODE (TREE_OPERAND (t, 2))))
8882 /* Only perform transformation if ARG0 is easily inverted. */
8883 tem = invert_truthvalue (arg0);
8884 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
8885 return fold (build2 (TRUTH_ANDIF_EXPR, type, tem,
8886 TREE_OPERAND (t, 2)));
8889 /* Convert A ? 1 : B into A || B if A and B are truth values. */
8890 if (integer_onep (arg1)
8891 && truth_value_p (TREE_CODE (arg0))
8892 && truth_value_p (TREE_CODE (TREE_OPERAND (t, 2))))
8893 return fold (build2 (TRUTH_ORIF_EXPR, type, arg0,
8894 TREE_OPERAND (t, 2)));
8899 /* When pedantic, a compound expression can be neither an lvalue
8900 nor an integer constant expression. */
8901 if (TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
8903 /* Don't let (0, 0) be null pointer constant. */
8904 tem = integer_zerop (arg1) ? build1 (NOP_EXPR, type, arg1)
8905 : fold_convert (type, arg1);
8906 return pedantic_non_lvalue (tem);
8910 return build_complex (type, arg0, arg1);
8914 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8916 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
8917 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
8918 TREE_OPERAND (arg0, 1));
8919 else if (TREE_CODE (arg0) == COMPLEX_CST)
8920 return TREE_REALPART (arg0);
8921 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8922 return fold (build2 (TREE_CODE (arg0), type,
8923 fold (build1 (REALPART_EXPR, type,
8924 TREE_OPERAND (arg0, 0))),
8925 fold (build1 (REALPART_EXPR, type,
8926 TREE_OPERAND (arg0, 1)))));
8930 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8931 return fold_convert (type, integer_zero_node);
8932 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
8933 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
8934 TREE_OPERAND (arg0, 0));
8935 else if (TREE_CODE (arg0) == COMPLEX_CST)
8936 return TREE_IMAGPART (arg0);
8937 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8938 return fold (build2 (TREE_CODE (arg0), type,
8939 fold (build1 (IMAGPART_EXPR, type,
8940 TREE_OPERAND (arg0, 0))),
8941 fold (build1 (IMAGPART_EXPR, type,
8942 TREE_OPERAND (arg0, 1)))));
8945 /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
8947 case CLEANUP_POINT_EXPR:
8948 if (! has_cleanups (arg0))
8949 return TREE_OPERAND (t, 0);
8952 enum tree_code code0 = TREE_CODE (arg0);
8953 int kind0 = TREE_CODE_CLASS (code0);
8954 tree arg00 = TREE_OPERAND (arg0, 0);
8957 if (kind0 == '1' || code0 == TRUTH_NOT_EXPR)
8958 return fold (build1 (code0, type,
8959 fold (build1 (CLEANUP_POINT_EXPR,
8960 TREE_TYPE (arg00), arg00))));
8962 if (kind0 == '<' || kind0 == '2'
8963 || code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR
8964 || code0 == TRUTH_AND_EXPR || code0 == TRUTH_OR_EXPR
8965 || code0 == TRUTH_XOR_EXPR)
8967 arg01 = TREE_OPERAND (arg0, 1);
8969 if (TREE_CONSTANT (arg00)
8970 || ((code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR)
8971 && ! has_cleanups (arg00)))
8972 return fold (build2 (code0, type, arg00,
8973 fold (build1 (CLEANUP_POINT_EXPR,
8974 TREE_TYPE (arg01), arg01))));
8976 if (TREE_CONSTANT (arg01))
8977 return fold (build2 (code0, type,
8978 fold (build1 (CLEANUP_POINT_EXPR,
8979 TREE_TYPE (arg00), arg00)),
8987 /* Check for a built-in function. */
8988 if (TREE_CODE (TREE_OPERAND (t, 0)) == ADDR_EXPR
8989 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0))
8991 && DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (t, 0), 0)))
8993 tree tmp = fold_builtin (t, false);
9001 } /* switch (code) */
9004 #ifdef ENABLE_FOLD_CHECKING
9007 static void fold_checksum_tree (tree, struct md5_ctx *, htab_t);
9008 static void fold_check_failed (tree, tree);
9009 void print_fold_checksum (tree);
9011 /* When --enable-checking=fold, compute a digest of expr before
9012 and after actual fold call to see if fold did not accidentally
9013 change original expr. */
9020 unsigned char checksum_before[16], checksum_after[16];
9023 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
9024 md5_init_ctx (&ctx);
9025 fold_checksum_tree (expr, &ctx, ht);
9026 md5_finish_ctx (&ctx, checksum_before);
9029 ret = fold_1 (expr);
9031 md5_init_ctx (&ctx);
9032 fold_checksum_tree (expr, &ctx, ht);
9033 md5_finish_ctx (&ctx, checksum_after);
9036 if (memcmp (checksum_before, checksum_after, 16))
9037 fold_check_failed (expr, ret);
9043 print_fold_checksum (tree expr)
9046 unsigned char checksum[16], cnt;
9049 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
9050 md5_init_ctx (&ctx);
9051 fold_checksum_tree (expr, &ctx, ht);
9052 md5_finish_ctx (&ctx, checksum);
9054 for (cnt = 0; cnt < 16; ++cnt)
9055 fprintf (stderr, "%02x", checksum[cnt]);
9056 putc ('\n', stderr);
9060 fold_check_failed (tree expr ATTRIBUTE_UNUSED, tree ret ATTRIBUTE_UNUSED)
9062 internal_error ("fold check: original tree changed by fold");
9066 fold_checksum_tree (tree expr, struct md5_ctx *ctx, htab_t ht)
9069 enum tree_code code;
9070 char buf[sizeof (struct tree_decl)];
9073 if (sizeof (struct tree_exp) + 5 * sizeof (tree)
9074 > sizeof (struct tree_decl)
9075 || sizeof (struct tree_type) > sizeof (struct tree_decl))
9079 slot = htab_find_slot (ht, expr, INSERT);
9083 code = TREE_CODE (expr);
9084 if (TREE_CODE_CLASS (code) == 'd' && DECL_ASSEMBLER_NAME_SET_P (expr))
9086 /* Allow DECL_ASSEMBLER_NAME to be modified. */
9087 memcpy (buf, expr, tree_size (expr));
9089 SET_DECL_ASSEMBLER_NAME (expr, NULL);
9091 else if (TREE_CODE_CLASS (code) == 't'
9092 && (TYPE_POINTER_TO (expr) || TYPE_REFERENCE_TO (expr)))
9094 /* Allow TYPE_POINTER_TO and TYPE_REFERENCE_TO to be modified. */
9095 memcpy (buf, expr, tree_size (expr));
9097 TYPE_POINTER_TO (expr) = NULL;
9098 TYPE_REFERENCE_TO (expr) = NULL;
9100 md5_process_bytes (expr, tree_size (expr), ctx);
9101 fold_checksum_tree (TREE_TYPE (expr), ctx, ht);
9102 if (TREE_CODE_CLASS (code) != 't' && TREE_CODE_CLASS (code) != 'd')
9103 fold_checksum_tree (TREE_CHAIN (expr), ctx, ht);
9104 switch (TREE_CODE_CLASS (code))
9110 md5_process_bytes (TREE_STRING_POINTER (expr),
9111 TREE_STRING_LENGTH (expr), ctx);
9114 fold_checksum_tree (TREE_REALPART (expr), ctx, ht);
9115 fold_checksum_tree (TREE_IMAGPART (expr), ctx, ht);
9118 fold_checksum_tree (TREE_VECTOR_CST_ELTS (expr), ctx, ht);
9128 fold_checksum_tree (TREE_PURPOSE (expr), ctx, ht);
9129 fold_checksum_tree (TREE_VALUE (expr), ctx, ht);
9132 for (i = 0; i < TREE_VEC_LENGTH (expr); ++i)
9133 fold_checksum_tree (TREE_VEC_ELT (expr, i), ctx, ht);
9145 len = first_rtl_op (code);
9146 for (i = 0; i < len; ++i)
9147 fold_checksum_tree (TREE_OPERAND (expr, i), ctx, ht);
9150 fold_checksum_tree (DECL_SIZE (expr), ctx, ht);
9151 fold_checksum_tree (DECL_SIZE_UNIT (expr), ctx, ht);
9152 fold_checksum_tree (DECL_NAME (expr), ctx, ht);
9153 fold_checksum_tree (DECL_CONTEXT (expr), ctx, ht);
9154 fold_checksum_tree (DECL_ARGUMENTS (expr), ctx, ht);
9155 fold_checksum_tree (DECL_RESULT_FLD (expr), ctx, ht);
9156 fold_checksum_tree (DECL_INITIAL (expr), ctx, ht);
9157 fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr), ctx, ht);
9158 fold_checksum_tree (DECL_SECTION_NAME (expr), ctx, ht);
9159 fold_checksum_tree (DECL_ATTRIBUTES (expr), ctx, ht);
9160 fold_checksum_tree (DECL_VINDEX (expr), ctx, ht);
9163 if (TREE_CODE (expr) == ENUMERAL_TYPE)
9164 fold_checksum_tree (TYPE_VALUES (expr), ctx, ht);
9165 fold_checksum_tree (TYPE_SIZE (expr), ctx, ht);
9166 fold_checksum_tree (TYPE_SIZE_UNIT (expr), ctx, ht);
9167 fold_checksum_tree (TYPE_ATTRIBUTES (expr), ctx, ht);
9168 fold_checksum_tree (TYPE_NAME (expr), ctx, ht);
9169 if (INTEGRAL_TYPE_P (expr)
9170 || SCALAR_FLOAT_TYPE_P (expr))
9172 fold_checksum_tree (TYPE_MIN_VALUE (expr), ctx, ht);
9173 fold_checksum_tree (TYPE_MAX_VALUE (expr), ctx, ht);
9175 fold_checksum_tree (TYPE_MAIN_VARIANT (expr), ctx, ht);
9176 fold_checksum_tree (TYPE_BINFO (expr), ctx, ht);
9177 fold_checksum_tree (TYPE_CONTEXT (expr), ctx, ht);
9186 /* Perform constant folding and related simplification of initializer
9187 expression EXPR. This behaves identically to "fold" but ignores
9188 potential run-time traps and exceptions that fold must preserve. */
9191 fold_initializer (tree expr)
9193 int saved_signaling_nans = flag_signaling_nans;
9194 int saved_trapping_math = flag_trapping_math;
9195 int saved_trapv = flag_trapv;
9198 flag_signaling_nans = 0;
9199 flag_trapping_math = 0;
9202 result = fold (expr);
9204 flag_signaling_nans = saved_signaling_nans;
9205 flag_trapping_math = saved_trapping_math;
9206 flag_trapv = saved_trapv;
9211 /* Determine if first argument is a multiple of second argument. Return 0 if
9212 it is not, or we cannot easily determined it to be.
9214 An example of the sort of thing we care about (at this point; this routine
9215 could surely be made more general, and expanded to do what the *_DIV_EXPR's
9216 fold cases do now) is discovering that
9218 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
9224 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
9226 This code also handles discovering that
9228 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
9230 is a multiple of 8 so we don't have to worry about dealing with a
9233 Note that we *look* inside a SAVE_EXPR only to determine how it was
9234 calculated; it is not safe for fold to do much of anything else with the
9235 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
9236 at run time. For example, the latter example above *cannot* be implemented
9237 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
9238 evaluation time of the original SAVE_EXPR is not necessarily the same at
9239 the time the new expression is evaluated. The only optimization of this
9240 sort that would be valid is changing
9242 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
9246 SAVE_EXPR (I) * SAVE_EXPR (J)
9248 (where the same SAVE_EXPR (J) is used in the original and the
9249 transformed version). */
9252 multiple_of_p (tree type, tree top, tree bottom)
9254 if (operand_equal_p (top, bottom, 0))
9257 if (TREE_CODE (type) != INTEGER_TYPE)
9260 switch (TREE_CODE (top))
9263 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
9264 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
9268 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
9269 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
9272 if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
9276 op1 = TREE_OPERAND (top, 1);
9277 /* const_binop may not detect overflow correctly,
9278 so check for it explicitly here. */
9279 if (TYPE_PRECISION (TREE_TYPE (size_one_node))
9280 > TREE_INT_CST_LOW (op1)
9281 && TREE_INT_CST_HIGH (op1) == 0
9282 && 0 != (t1 = fold_convert (type,
9283 const_binop (LSHIFT_EXPR,
9286 && ! TREE_OVERFLOW (t1))
9287 return multiple_of_p (type, t1, bottom);
9292 /* Can't handle conversions from non-integral or wider integral type. */
9293 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
9294 || (TYPE_PRECISION (type)
9295 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
9298 /* .. fall through ... */
9301 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
9304 if (TREE_CODE (bottom) != INTEGER_CST
9305 || (TYPE_UNSIGNED (type)
9306 && (tree_int_cst_sgn (top) < 0
9307 || tree_int_cst_sgn (bottom) < 0)))
9309 return integer_zerop (const_binop (TRUNC_MOD_EXPR,
9317 /* Return true if `t' is known to be non-negative. */
9320 tree_expr_nonnegative_p (tree t)
9322 switch (TREE_CODE (t))
9328 return tree_int_cst_sgn (t) >= 0;
9331 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
9334 if (FLOAT_TYPE_P (TREE_TYPE (t)))
9335 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9336 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9338 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
9339 both unsigned and at least 2 bits shorter than the result. */
9340 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
9341 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
9342 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
9344 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
9345 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
9346 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
9347 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
9349 unsigned int prec = MAX (TYPE_PRECISION (inner1),
9350 TYPE_PRECISION (inner2)) + 1;
9351 return prec < TYPE_PRECISION (TREE_TYPE (t));
9357 if (FLOAT_TYPE_P (TREE_TYPE (t)))
9359 /* x * x for floating point x is always non-negative. */
9360 if (operand_equal_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1), 0))
9362 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9363 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9366 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
9367 both unsigned and their total bits is shorter than the result. */
9368 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
9369 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
9370 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
9372 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
9373 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
9374 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
9375 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
9376 return TYPE_PRECISION (inner1) + TYPE_PRECISION (inner2)
9377 < TYPE_PRECISION (TREE_TYPE (t));
9381 case TRUNC_DIV_EXPR:
9383 case FLOOR_DIV_EXPR:
9384 case ROUND_DIV_EXPR:
9385 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9386 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9388 case TRUNC_MOD_EXPR:
9390 case FLOOR_MOD_EXPR:
9391 case ROUND_MOD_EXPR:
9392 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9395 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9396 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9399 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
9400 || tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9403 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9404 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9408 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
9409 tree outer_type = TREE_TYPE (t);
9411 if (TREE_CODE (outer_type) == REAL_TYPE)
9413 if (TREE_CODE (inner_type) == REAL_TYPE)
9414 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9415 if (TREE_CODE (inner_type) == INTEGER_TYPE)
9417 if (TYPE_UNSIGNED (inner_type))
9419 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9422 else if (TREE_CODE (outer_type) == INTEGER_TYPE)
9424 if (TREE_CODE (inner_type) == REAL_TYPE)
9425 return tree_expr_nonnegative_p (TREE_OPERAND (t,0));
9426 if (TREE_CODE (inner_type) == INTEGER_TYPE)
9427 return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
9428 && TYPE_UNSIGNED (inner_type);
9434 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
9435 && tree_expr_nonnegative_p (TREE_OPERAND (t, 2));
9437 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9439 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9440 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9442 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9443 || tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9445 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9447 return tree_expr_nonnegative_p (expr_last (TREE_OPERAND (t, 1)));
9449 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9450 case NON_LVALUE_EXPR:
9451 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9453 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9457 tree temp = TARGET_EXPR_SLOT (t);
9458 t = TARGET_EXPR_INITIAL (t);
9460 /* If the initializer is non-void, then it's a normal expression
9461 that will be assigned to the slot. */
9462 if (!VOID_TYPE_P (t))
9463 return tree_expr_nonnegative_p (t);
9465 /* Otherwise, the initializer sets the slot in some way. One common
9466 way is an assignment statement at the end of the initializer. */
9469 if (TREE_CODE (t) == BIND_EXPR)
9470 t = expr_last (BIND_EXPR_BODY (t));
9471 else if (TREE_CODE (t) == TRY_FINALLY_EXPR
9472 || TREE_CODE (t) == TRY_CATCH_EXPR)
9473 t = expr_last (TREE_OPERAND (t, 0));
9474 else if (TREE_CODE (t) == STATEMENT_LIST)
9479 if (TREE_CODE (t) == MODIFY_EXPR
9480 && TREE_OPERAND (t, 0) == temp)
9481 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9488 tree fndecl = get_callee_fndecl (t);
9489 tree arglist = TREE_OPERAND (t, 1);
9491 && DECL_BUILT_IN (fndecl)
9492 && DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_MD)
9493 switch (DECL_FUNCTION_CODE (fndecl))
9495 #define CASE_BUILTIN_F(BUILT_IN_FN) \
9496 case BUILT_IN_FN: case BUILT_IN_FN##F: case BUILT_IN_FN##L:
9497 #define CASE_BUILTIN_I(BUILT_IN_FN) \
9498 case BUILT_IN_FN: case BUILT_IN_FN##L: case BUILT_IN_FN##LL:
9500 CASE_BUILTIN_F (BUILT_IN_ACOS)
9501 CASE_BUILTIN_F (BUILT_IN_ACOSH)
9502 CASE_BUILTIN_F (BUILT_IN_CABS)
9503 CASE_BUILTIN_F (BUILT_IN_COSH)
9504 CASE_BUILTIN_F (BUILT_IN_ERFC)
9505 CASE_BUILTIN_F (BUILT_IN_EXP)
9506 CASE_BUILTIN_F (BUILT_IN_EXP10)
9507 CASE_BUILTIN_F (BUILT_IN_EXP2)
9508 CASE_BUILTIN_F (BUILT_IN_FABS)
9509 CASE_BUILTIN_F (BUILT_IN_FDIM)
9510 CASE_BUILTIN_F (BUILT_IN_FREXP)
9511 CASE_BUILTIN_F (BUILT_IN_HYPOT)
9512 CASE_BUILTIN_F (BUILT_IN_POW10)
9513 CASE_BUILTIN_I (BUILT_IN_FFS)
9514 CASE_BUILTIN_I (BUILT_IN_PARITY)
9515 CASE_BUILTIN_I (BUILT_IN_POPCOUNT)
9519 CASE_BUILTIN_F (BUILT_IN_SQRT)
9520 /* sqrt(-0.0) is -0.0. */
9521 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (t))))
9523 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
9525 CASE_BUILTIN_F (BUILT_IN_ASINH)
9526 CASE_BUILTIN_F (BUILT_IN_ATAN)
9527 CASE_BUILTIN_F (BUILT_IN_ATANH)
9528 CASE_BUILTIN_F (BUILT_IN_CBRT)
9529 CASE_BUILTIN_F (BUILT_IN_CEIL)
9530 CASE_BUILTIN_F (BUILT_IN_ERF)
9531 CASE_BUILTIN_F (BUILT_IN_EXPM1)
9532 CASE_BUILTIN_F (BUILT_IN_FLOOR)
9533 CASE_BUILTIN_F (BUILT_IN_FMOD)
9534 CASE_BUILTIN_F (BUILT_IN_LDEXP)
9535 CASE_BUILTIN_F (BUILT_IN_LLRINT)
9536 CASE_BUILTIN_F (BUILT_IN_LLROUND)
9537 CASE_BUILTIN_F (BUILT_IN_LRINT)
9538 CASE_BUILTIN_F (BUILT_IN_LROUND)
9539 CASE_BUILTIN_F (BUILT_IN_MODF)
9540 CASE_BUILTIN_F (BUILT_IN_NEARBYINT)
9541 CASE_BUILTIN_F (BUILT_IN_POW)
9542 CASE_BUILTIN_F (BUILT_IN_RINT)
9543 CASE_BUILTIN_F (BUILT_IN_ROUND)
9544 CASE_BUILTIN_F (BUILT_IN_SIGNBIT)
9545 CASE_BUILTIN_F (BUILT_IN_SINH)
9546 CASE_BUILTIN_F (BUILT_IN_TANH)
9547 CASE_BUILTIN_F (BUILT_IN_TRUNC)
9548 /* True if the 1st argument is nonnegative. */
9549 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
9551 CASE_BUILTIN_F (BUILT_IN_FMAX)
9552 /* True if the 1st OR 2nd arguments are nonnegative. */
9553 return tree_expr_nonnegative_p (TREE_VALUE (arglist))
9554 || tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist)));
9556 CASE_BUILTIN_F (BUILT_IN_FMIN)
9557 /* True if the 1st AND 2nd arguments are nonnegative. */
9558 return tree_expr_nonnegative_p (TREE_VALUE (arglist))
9559 && tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist)));
9561 CASE_BUILTIN_F (BUILT_IN_COPYSIGN)
9562 /* True if the 2nd argument is nonnegative. */
9563 return tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist)));
9567 #undef CASE_BUILTIN_F
9568 #undef CASE_BUILTIN_I
9572 /* ... fall through ... */
9575 if (truth_value_p (TREE_CODE (t)))
9576 /* Truth values evaluate to 0 or 1, which is nonnegative. */
9580 /* We don't know sign of `t', so be conservative and return false. */
9584 /* Return true when T is an address and is known to be nonzero.
9585 For floating point we further ensure that T is not denormal.
9586 Similar logic is present in nonzero_address in rtlanal.h */
9589 tree_expr_nonzero_p (tree t)
9591 tree type = TREE_TYPE (t);
9593 /* Doing something useful for floating point would need more work. */
9594 if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
9597 switch (TREE_CODE (t))
9600 if (!TYPE_UNSIGNED (type) && !flag_wrapv)
9601 return tree_expr_nonzero_p (TREE_OPERAND (t, 0));
9604 return !integer_zerop (t);
9607 if (!TYPE_UNSIGNED (type) && !flag_wrapv)
9609 /* With the presence of negative values it is hard
9610 to say something. */
9611 if (!tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9612 || !tree_expr_nonnegative_p (TREE_OPERAND (t, 1)))
9614 /* One of operands must be positive and the other non-negative. */
9615 return (tree_expr_nonzero_p (TREE_OPERAND (t, 0))
9616 || tree_expr_nonzero_p (TREE_OPERAND (t, 1)));
9621 if (!TYPE_UNSIGNED (type) && !flag_wrapv)
9623 return (tree_expr_nonzero_p (TREE_OPERAND (t, 0))
9624 && tree_expr_nonzero_p (TREE_OPERAND (t, 1)));
9630 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
9631 tree outer_type = TREE_TYPE (t);
9633 return (TYPE_PRECISION (inner_type) >= TYPE_PRECISION (outer_type)
9634 && tree_expr_nonzero_p (TREE_OPERAND (t, 0)));
9639 /* Weak declarations may link to NULL. */
9640 if (DECL_P (TREE_OPERAND (t, 0)))
9641 return !DECL_WEAK (TREE_OPERAND (t, 0));
9642 /* Constants and all other cases are never weak. */
9646 return (tree_expr_nonzero_p (TREE_OPERAND (t, 1))
9647 && tree_expr_nonzero_p (TREE_OPERAND (t, 2)));
9650 return (tree_expr_nonzero_p (TREE_OPERAND (t, 0))
9651 && tree_expr_nonzero_p (TREE_OPERAND (t, 1)));
9654 if (tree_expr_nonzero_p (TREE_OPERAND (t, 0)))
9656 /* When both operands are nonzero, then MAX must be too. */
9657 if (tree_expr_nonzero_p (TREE_OPERAND (t, 1)))
9660 /* MAX where operand 0 is positive is positive. */
9661 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9663 /* MAX where operand 1 is positive is positive. */
9664 else if (tree_expr_nonzero_p (TREE_OPERAND (t, 1))
9665 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1)))
9672 return tree_expr_nonzero_p (TREE_OPERAND (t, 1));
9675 case NON_LVALUE_EXPR:
9676 return tree_expr_nonzero_p (TREE_OPERAND (t, 0));
9679 return tree_expr_nonzero_p (TREE_OPERAND (t, 1))
9680 || tree_expr_nonzero_p (TREE_OPERAND (t, 0));
9688 /* Return true if `r' is known to be non-negative.
9689 Only handles constants at the moment. */
9692 rtl_expr_nonnegative_p (rtx r)
9694 switch (GET_CODE (r))
9697 return INTVAL (r) >= 0;
9700 if (GET_MODE (r) == VOIDmode)
9701 return CONST_DOUBLE_HIGH (r) >= 0;
9709 units = CONST_VECTOR_NUNITS (r);
9711 for (i = 0; i < units; ++i)
9713 elt = CONST_VECTOR_ELT (r, i);
9714 if (!rtl_expr_nonnegative_p (elt))
9723 /* These are always nonnegative. */
9732 /* See if we are applying CODE, a relational to the highest or lowest
9733 possible integer of TYPE. If so, then the result is a compile
9737 fold_relational_hi_lo (enum tree_code *code_p, const tree type, tree *op0_p,
9742 enum tree_code code = *code_p;
9743 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (op1)));
9745 if (TREE_CODE (op1) == INTEGER_CST
9746 && ! TREE_CONSTANT_OVERFLOW (op1)
9747 && width <= HOST_BITS_PER_WIDE_INT
9748 && (INTEGRAL_TYPE_P (TREE_TYPE (op1))
9749 || POINTER_TYPE_P (TREE_TYPE (op1))))
9751 unsigned HOST_WIDE_INT signed_max;
9752 unsigned HOST_WIDE_INT max, min;
9754 signed_max = ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1;
9756 if (TYPE_UNSIGNED (TREE_TYPE (op1)))
9758 max = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
9764 min = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
9767 if (TREE_INT_CST_HIGH (op1) == 0
9768 && TREE_INT_CST_LOW (op1) == max)
9772 return omit_one_operand (type, integer_zero_node, op0);
9778 return omit_one_operand (type, integer_one_node, op0);
9784 /* The GE_EXPR and LT_EXPR cases above are not normally
9785 reached because of previous transformations. */
9790 else if (TREE_INT_CST_HIGH (op1) == 0
9791 && TREE_INT_CST_LOW (op1) == max - 1)
9796 *op1_p = const_binop (PLUS_EXPR, op1, integer_one_node, 0);
9800 *op1_p = const_binop (PLUS_EXPR, op1, integer_one_node, 0);
9805 else if (TREE_INT_CST_HIGH (op1) == (min ? -1 : 0)
9806 && TREE_INT_CST_LOW (op1) == min)
9810 return omit_one_operand (type, integer_zero_node, op0);
9817 return omit_one_operand (type, integer_one_node, op0);
9826 else if (TREE_INT_CST_HIGH (op1) == (min ? -1 : 0)
9827 && TREE_INT_CST_LOW (op1) == min + 1)
9832 *op1_p = const_binop (MINUS_EXPR, op1, integer_one_node, 0);
9836 *op1_p = const_binop (MINUS_EXPR, op1, integer_one_node, 0);
9842 else if (TREE_INT_CST_HIGH (op1) == 0
9843 && TREE_INT_CST_LOW (op1) == signed_max
9844 && TYPE_UNSIGNED (TREE_TYPE (op1))
9845 /* signed_type does not work on pointer types. */
9846 && INTEGRAL_TYPE_P (TREE_TYPE (op1)))
9848 /* The following case also applies to X < signed_max+1
9849 and X >= signed_max+1 because previous transformations. */
9850 if (code == LE_EXPR || code == GT_EXPR)
9852 tree st0, st1, exp, retval;
9853 st0 = lang_hooks.types.signed_type (TREE_TYPE (op0));
9854 st1 = lang_hooks.types.signed_type (TREE_TYPE (op1));
9856 exp = build2 (code == LE_EXPR ? GE_EXPR: LT_EXPR,
9858 fold_convert (st0, op0),
9859 fold_convert (st1, integer_zero_node));
9862 = nondestructive_fold_binary_to_constant (TREE_CODE (exp),
9864 TREE_OPERAND (exp, 0),
9865 TREE_OPERAND (exp, 1));
9867 /* If we are in gimple form, then returning EXP would create
9868 non-gimple expressions. Clearing it is safe and insures
9869 we do not allow a non-gimple expression to escape. */
9873 return (retval ? retval : exp);
9882 /* Given the components of a binary expression CODE, TYPE, OP0 and OP1,
9883 attempt to fold the expression to a constant without modifying TYPE,
9886 If the expression could be simplified to a constant, then return
9887 the constant. If the expression would not be simplified to a
9888 constant, then return NULL_TREE.
9890 Note this is primarily designed to be called after gimplification
9891 of the tree structures and when at least one operand is a constant.
9892 As a result of those simplifying assumptions this routine is far
9893 simpler than the generic fold routine. */
9896 nondestructive_fold_binary_to_constant (enum tree_code code, tree type,
9904 /* If this is a commutative operation, and ARG0 is a constant, move it
9905 to ARG1 to reduce the number of tests below. */
9906 if (commutative_tree_code (code)
9907 && (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST))
9914 /* If either operand is a complex type, extract its real component. */
9915 if (TREE_CODE (op0) == COMPLEX_CST)
9916 subop0 = TREE_REALPART (op0);
9920 if (TREE_CODE (op1) == COMPLEX_CST)
9921 subop1 = TREE_REALPART (op1);
9925 /* Note if either argument is not a real or integer constant.
9926 With a few exceptions, simplification is limited to cases
9927 where both arguments are constants. */
9928 if ((TREE_CODE (subop0) != INTEGER_CST
9929 && TREE_CODE (subop0) != REAL_CST)
9930 || (TREE_CODE (subop1) != INTEGER_CST
9931 && TREE_CODE (subop1) != REAL_CST))
9937 /* (plus (address) (const_int)) is a constant. */
9938 if (TREE_CODE (op0) == PLUS_EXPR
9939 && TREE_CODE (op1) == INTEGER_CST
9940 && (TREE_CODE (TREE_OPERAND (op0, 0)) == ADDR_EXPR
9941 || (TREE_CODE (TREE_OPERAND (op0, 0)) == NOP_EXPR
9942 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (op0, 0), 0))
9944 && TREE_CODE (TREE_OPERAND (op0, 1)) == INTEGER_CST)
9946 return build2 (PLUS_EXPR, type, TREE_OPERAND (op0, 0),
9947 const_binop (PLUS_EXPR, op1,
9948 TREE_OPERAND (op0, 1), 0));
9956 /* Both arguments are constants. Simplify. */
9957 tem = const_binop (code, op0, op1, 0);
9958 if (tem != NULL_TREE)
9960 /* The return value should always have the same type as
9961 the original expression. */
9962 if (TREE_TYPE (tem) != type)
9963 tem = fold_convert (type, tem);
9970 /* Fold &x - &x. This can happen from &x.foo - &x.
9971 This is unsafe for certain floats even in non-IEEE formats.
9972 In IEEE, it is unsafe because it does wrong for NaNs.
9973 Also note that operand_equal_p is always false if an
9974 operand is volatile. */
9975 if (! FLOAT_TYPE_P (type) && operand_equal_p (op0, op1, 0))
9976 return fold_convert (type, integer_zero_node);
9982 /* Special case multiplication or bitwise AND where one argument
9984 if (! FLOAT_TYPE_P (type) && integer_zerop (op1))
9985 return omit_one_operand (type, op1, op0);
9987 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (op0)))
9988 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (op0)))
9989 && real_zerop (op1))
9990 return omit_one_operand (type, op1, op0);
9995 /* Special case when we know the result will be all ones. */
9996 if (integer_all_onesp (op1))
9997 return omit_one_operand (type, op1, op0);
10001 case TRUNC_DIV_EXPR:
10002 case ROUND_DIV_EXPR:
10003 case FLOOR_DIV_EXPR:
10004 case CEIL_DIV_EXPR:
10005 case EXACT_DIV_EXPR:
10006 case TRUNC_MOD_EXPR:
10007 case ROUND_MOD_EXPR:
10008 case FLOOR_MOD_EXPR:
10009 case CEIL_MOD_EXPR:
10011 /* Division by zero is undefined. */
10012 if (integer_zerop (op1))
10015 if (TREE_CODE (op1) == REAL_CST
10016 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (op1)))
10017 && real_zerop (op1))
10023 if (INTEGRAL_TYPE_P (type)
10024 && operand_equal_p (op1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
10025 return omit_one_operand (type, op1, op0);
10030 if (INTEGRAL_TYPE_P (type)
10031 && TYPE_MAX_VALUE (type)
10032 && operand_equal_p (op1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
10033 return omit_one_operand (type, op1, op0);
10038 /* Optimize -1 >> x for arithmetic right shifts. */
10039 if (integer_all_onesp (op0) && ! TYPE_UNSIGNED (type))
10040 return omit_one_operand (type, op0, op1);
10041 /* ... fall through ... */
10044 if (integer_zerop (op0))
10045 return omit_one_operand (type, op0, op1);
10047 /* Since negative shift count is not well-defined, don't
10048 try to compute it in the compiler. */
10049 if (TREE_CODE (op1) == INTEGER_CST && tree_int_cst_sgn (op1) < 0)
10056 /* -1 rotated either direction by any amount is still -1. */
10057 if (integer_all_onesp (op0))
10058 return omit_one_operand (type, op0, op1);
10060 /* 0 rotated either direction by any amount is still zero. */
10061 if (integer_zerop (op0))
10062 return omit_one_operand (type, op0, op1);
10068 return build_complex (type, op0, op1);
10077 /* If one arg is a real or integer constant, put it last. */
10078 if ((TREE_CODE (op0) == INTEGER_CST
10079 && TREE_CODE (op1) != INTEGER_CST)
10080 || (TREE_CODE (op0) == REAL_CST
10081 && TREE_CODE (op0) != REAL_CST))
10088 code = swap_tree_comparison (code);
10091 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
10092 This transformation affects the cases which are handled in later
10093 optimizations involving comparisons with non-negative constants. */
10094 if (TREE_CODE (op1) == INTEGER_CST
10095 && TREE_CODE (op0) != INTEGER_CST
10096 && tree_int_cst_sgn (op1) > 0)
10102 op1 = const_binop (MINUS_EXPR, op1, integer_one_node, 0);
10107 op1 = const_binop (MINUS_EXPR, op1, integer_one_node, 0);
10115 tem = fold_relational_hi_lo (&code, type, &op0, &op1);
10119 /* Fall through. */
10122 case UNORDERED_EXPR:
10132 return fold_relational_const (code, type, op0, op1);
10135 /* This could probably be handled. */
10138 case TRUTH_AND_EXPR:
10139 /* If second arg is constant zero, result is zero, but first arg
10140 must be evaluated. */
10141 if (integer_zerop (op1))
10142 return omit_one_operand (type, op1, op0);
10143 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
10144 case will be handled here. */
10145 if (integer_zerop (op0))
10146 return omit_one_operand (type, op0, op1);
10147 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
10148 return constant_boolean_node (true, type);
10151 case TRUTH_OR_EXPR:
10152 /* If second arg is constant true, result is true, but we must
10153 evaluate first arg. */
10154 if (TREE_CODE (op1) == INTEGER_CST && ! integer_zerop (op1))
10155 return omit_one_operand (type, op1, op0);
10156 /* Likewise for first arg, but note this only occurs here for
10158 if (TREE_CODE (op0) == INTEGER_CST && ! integer_zerop (op0))
10159 return omit_one_operand (type, op0, op1);
10160 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
10161 return constant_boolean_node (false, type);
10164 case TRUTH_XOR_EXPR:
10165 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
10167 int x = ! integer_zerop (op0) ^ ! integer_zerop (op1);
10168 return constant_boolean_node (x, type);
10177 /* Given the components of a unary expression CODE, TYPE and OP0,
10178 attempt to fold the expression to a constant without modifying
10181 If the expression could be simplified to a constant, then return
10182 the constant. If the expression would not be simplified to a
10183 constant, then return NULL_TREE.
10185 Note this is primarily designed to be called after gimplification
10186 of the tree structures and when op0 is a constant. As a result
10187 of those simplifying assumptions this routine is far simpler than
10188 the generic fold routine. */
10191 nondestructive_fold_unary_to_constant (enum tree_code code, tree type,
10194 /* Make sure we have a suitable constant argument. */
10195 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
10199 if (TREE_CODE (op0) == COMPLEX_CST)
10200 subop = TREE_REALPART (op0);
10204 if (TREE_CODE (subop) != INTEGER_CST && TREE_CODE (subop) != REAL_CST)
10213 case FIX_TRUNC_EXPR:
10214 case FIX_FLOOR_EXPR:
10215 case FIX_CEIL_EXPR:
10216 return fold_convert_const (code, type, op0);
10219 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
10220 return fold_negate_const (op0, type);
10225 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
10226 return fold_abs_const (op0, type);
10231 if (TREE_CODE (op0) == INTEGER_CST)
10232 return fold_not_const (op0, type);
10236 case REALPART_EXPR:
10237 if (TREE_CODE (op0) == COMPLEX_CST)
10238 return TREE_REALPART (op0);
10242 case IMAGPART_EXPR:
10243 if (TREE_CODE (op0) == COMPLEX_CST)
10244 return TREE_IMAGPART (op0);
10249 if (TREE_CODE (op0) == COMPLEX_CST
10250 && TREE_CODE (TREE_TYPE (op0)) == COMPLEX_TYPE)
10251 return build_complex (type, TREE_REALPART (op0),
10252 negate_expr (TREE_IMAGPART (op0)));
10260 /* If EXP represents referencing an element in a constant string
10261 (either via pointer arithmetic or array indexing), return the
10262 tree representing the value accessed, otherwise return NULL. */
10265 fold_read_from_constant_string (tree exp)
10267 if (TREE_CODE (exp) == INDIRECT_REF || TREE_CODE (exp) == ARRAY_REF)
10269 tree exp1 = TREE_OPERAND (exp, 0);
10273 if (TREE_CODE (exp) == INDIRECT_REF)
10274 string = string_constant (exp1, &index);
10277 tree low_bound = array_ref_low_bound (exp);
10278 index = fold_convert (sizetype, TREE_OPERAND (exp, 1));
10280 /* Optimize the special-case of a zero lower bound.
10282 We convert the low_bound to sizetype to avoid some problems
10283 with constant folding. (E.g. suppose the lower bound is 1,
10284 and its mode is QI. Without the conversion,l (ARRAY
10285 +(INDEX-(unsigned char)1)) becomes ((ARRAY+(-(unsigned char)1))
10286 +INDEX), which becomes (ARRAY+255+INDEX). Opps!) */
10287 if (! integer_zerop (low_bound))
10288 index = size_diffop (index, fold_convert (sizetype, low_bound));
10294 && TREE_TYPE (exp) == TREE_TYPE (TREE_TYPE (string))
10295 && TREE_CODE (string) == STRING_CST
10296 && TREE_CODE (index) == INTEGER_CST
10297 && compare_tree_int (index, TREE_STRING_LENGTH (string)) < 0
10298 && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (string))))
10300 && (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))) == 1))
10301 return fold_convert (TREE_TYPE (exp),
10302 build_int_2 ((TREE_STRING_POINTER (string)
10303 [TREE_INT_CST_LOW (index)]), 0));
10308 /* Return the tree for neg (ARG0) when ARG0 is known to be either
10309 an integer constant or real constant.
10311 TYPE is the type of the result. */
10314 fold_negate_const (tree arg0, tree type)
10316 tree t = NULL_TREE;
10318 if (TREE_CODE (arg0) == INTEGER_CST)
10320 unsigned HOST_WIDE_INT low;
10321 HOST_WIDE_INT high;
10322 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
10323 TREE_INT_CST_HIGH (arg0),
10325 t = build_int_2 (low, high);
10326 TREE_TYPE (t) = type;
10328 = (TREE_OVERFLOW (arg0)
10329 | force_fit_type (t, overflow && !TYPE_UNSIGNED (type)));
10330 TREE_CONSTANT_OVERFLOW (t)
10331 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
10333 else if (TREE_CODE (arg0) == REAL_CST)
10334 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
10335 #ifdef ENABLE_CHECKING
10343 /* Return the tree for abs (ARG0) when ARG0 is known to be either
10344 an integer constant or real constant.
10346 TYPE is the type of the result. */
10349 fold_abs_const (tree arg0, tree type)
10351 tree t = NULL_TREE;
10353 if (TREE_CODE (arg0) == INTEGER_CST)
10355 /* If the value is unsigned, then the absolute value is
10356 the same as the ordinary value. */
10357 if (TYPE_UNSIGNED (type))
10359 /* Similarly, if the value is non-negative. */
10360 else if (INT_CST_LT (integer_minus_one_node, arg0))
10362 /* If the value is negative, then the absolute value is
10366 unsigned HOST_WIDE_INT low;
10367 HOST_WIDE_INT high;
10368 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
10369 TREE_INT_CST_HIGH (arg0),
10371 t = build_int_2 (low, high);
10372 TREE_TYPE (t) = type;
10374 = (TREE_OVERFLOW (arg0)
10375 | force_fit_type (t, overflow));
10376 TREE_CONSTANT_OVERFLOW (t)
10377 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
10381 else if (TREE_CODE (arg0) == REAL_CST)
10383 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
10384 return build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
10388 #ifdef ENABLE_CHECKING
10396 /* Return the tree for not (ARG0) when ARG0 is known to be an integer
10397 constant. TYPE is the type of the result. */
10400 fold_not_const (tree arg0, tree type)
10402 tree t = NULL_TREE;
10404 if (TREE_CODE (arg0) == INTEGER_CST)
10406 t = build_int_2 (~ TREE_INT_CST_LOW (arg0),
10407 ~ TREE_INT_CST_HIGH (arg0));
10408 TREE_TYPE (t) = type;
10409 force_fit_type (t, 0);
10410 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg0);
10411 TREE_CONSTANT_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (arg0);
10413 #ifdef ENABLE_CHECKING
10421 /* Given CODE, a relational operator, the target type, TYPE and two
10422 constant operands OP0 and OP1, return the result of the
10423 relational operation. If the result is not a compile time
10424 constant, then return NULL_TREE. */
10427 fold_relational_const (enum tree_code code, tree type, tree op0, tree op1)
10429 int result, invert;
10431 /* From here on, the only cases we handle are when the result is
10432 known to be a constant. */
10434 if (TREE_CODE (op0) == REAL_CST && TREE_CODE (op1) == REAL_CST)
10436 const REAL_VALUE_TYPE *c0 = TREE_REAL_CST_PTR (op0);
10437 const REAL_VALUE_TYPE *c1 = TREE_REAL_CST_PTR (op1);
10439 /* Handle the cases where either operand is a NaN. */
10440 if (real_isnan (c0) || real_isnan (c1))
10450 case UNORDERED_EXPR:
10464 if (flag_trapping_math)
10473 return constant_boolean_node (result, type);
10476 return constant_boolean_node (real_compare (code, c0, c1), type);
10479 /* From here on we only handle LT, LE, GT, GE, EQ and NE.
10481 To compute GT, swap the arguments and do LT.
10482 To compute GE, do LT and invert the result.
10483 To compute LE, swap the arguments, do LT and invert the result.
10484 To compute NE, do EQ and invert the result.
10486 Therefore, the code below must handle only EQ and LT. */
10488 if (code == LE_EXPR || code == GT_EXPR)
10493 code = swap_tree_comparison (code);
10496 /* Note that it is safe to invert for real values here because we
10497 have already handled the one case that it matters. */
10500 if (code == NE_EXPR || code == GE_EXPR)
10503 code = invert_tree_comparison (code, false);
10506 /* Compute a result for LT or EQ if args permit;
10507 Otherwise return T. */
10508 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
10510 if (code == EQ_EXPR)
10511 result = tree_int_cst_equal (op0, op1);
10512 else if (TYPE_UNSIGNED (TREE_TYPE (op0)))
10513 result = INT_CST_LT_UNSIGNED (op0, op1);
10515 result = INT_CST_LT (op0, op1);
10522 return constant_boolean_node (result, type);
10525 /* Build an expression for the address of T. Folds away INDIRECT_REF to
10526 avoid confusing the gimplify process. */
10529 build_fold_addr_expr_with_type (tree t, tree ptrtype)
10531 if (TREE_CODE (t) == INDIRECT_REF)
10533 t = TREE_OPERAND (t, 0);
10534 if (TREE_TYPE (t) != ptrtype)
10535 t = build1 (NOP_EXPR, ptrtype, t);
10541 while (handled_component_p (base)
10542 || TREE_CODE (base) == REALPART_EXPR
10543 || TREE_CODE (base) == IMAGPART_EXPR)
10544 base = TREE_OPERAND (base, 0);
10546 TREE_ADDRESSABLE (base) = 1;
10548 t = build1 (ADDR_EXPR, ptrtype, t);
10555 build_fold_addr_expr (tree t)
10557 return build_fold_addr_expr_with_type (t, build_pointer_type (TREE_TYPE (t)));
10560 /* Builds an expression for an indirection through T, simplifying some
10564 build_fold_indirect_ref (tree t)
10566 tree type = TREE_TYPE (TREE_TYPE (t));
10571 if (TREE_CODE (sub) == ADDR_EXPR)
10573 tree op = TREE_OPERAND (sub, 0);
10574 tree optype = TREE_TYPE (op);
10576 if (lang_hooks.types_compatible_p (type, optype))
10578 /* *(foo *)&fooarray => fooarray[0] */
10579 else if (TREE_CODE (optype) == ARRAY_TYPE
10580 && lang_hooks.types_compatible_p (type, TREE_TYPE (optype)))
10581 return build4 (ARRAY_REF, type, op, size_zero_node, NULL_TREE, NULL_TREE);
10584 /* *(foo *)fooarrptr => (*fooarrptr)[0] */
10585 subtype = TREE_TYPE (sub);
10586 if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE
10587 && lang_hooks.types_compatible_p (type, TREE_TYPE (TREE_TYPE (subtype))))
10589 sub = build_fold_indirect_ref (sub);
10590 return build4 (ARRAY_REF, type, sub, size_zero_node, NULL_TREE, NULL_TREE);
10593 return build1 (INDIRECT_REF, type, t);
10596 /* Strip non-trapping, non-side-effecting tree nodes from an expression
10597 whose result is ignored. The type of the returned tree need not be
10598 the same as the original expression. */
10601 fold_ignored_result (tree t)
10603 if (!TREE_SIDE_EFFECTS (t))
10604 return integer_zero_node;
10607 switch (TREE_CODE_CLASS (TREE_CODE (t)))
10610 t = TREE_OPERAND (t, 0);
10615 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
10616 t = TREE_OPERAND (t, 0);
10617 else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0)))
10618 t = TREE_OPERAND (t, 1);
10624 switch (TREE_CODE (t))
10626 case COMPOUND_EXPR:
10627 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
10629 t = TREE_OPERAND (t, 0);
10633 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1))
10634 || TREE_SIDE_EFFECTS (TREE_OPERAND (t, 2)))
10636 t = TREE_OPERAND (t, 0);
10649 #include "gt-fold-const.h"