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 static void encode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT, HOST_WIDE_INT);
62 static void decode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
63 static bool negate_mathfn_p (enum built_in_function);
64 static bool negate_expr_p (tree);
65 static tree negate_expr (tree);
66 static tree split_tree (tree, enum tree_code, tree *, tree *, tree *, int);
67 static tree associate_trees (tree, tree, enum tree_code, tree);
68 static tree int_const_binop (enum tree_code, tree, tree, int);
69 static tree const_binop (enum tree_code, tree, tree, int);
70 static hashval_t size_htab_hash (const void *);
71 static int size_htab_eq (const void *, const void *);
72 static tree fold_convert_const (enum tree_code, tree, tree);
73 static tree fold_convert (tree, tree);
74 static enum tree_code invert_tree_comparison (enum tree_code);
75 static enum tree_code swap_tree_comparison (enum tree_code);
76 static int comparison_to_compcode (enum tree_code);
77 static enum tree_code compcode_to_comparison (int);
78 static int truth_value_p (enum tree_code);
79 static int operand_equal_for_comparison_p (tree, tree, tree);
80 static int twoval_comparison_p (tree, tree *, tree *, int *);
81 static tree eval_subst (tree, tree, tree, tree, tree);
82 static tree pedantic_omit_one_operand (tree, tree, tree);
83 static tree distribute_bit_expr (enum tree_code, tree, tree, tree);
84 static tree make_bit_field_ref (tree, tree, int, int, int);
85 static tree optimize_bit_field_compare (enum tree_code, tree, tree, tree);
86 static tree decode_field_reference (tree, HOST_WIDE_INT *, HOST_WIDE_INT *,
87 enum machine_mode *, int *, int *,
89 static int all_ones_mask_p (tree, int);
90 static tree sign_bit_p (tree, tree);
91 static int simple_operand_p (tree);
92 static tree range_binop (enum tree_code, tree, tree, int, tree, int);
93 static tree make_range (tree, int *, tree *, tree *);
94 static tree build_range_check (tree, tree, int, tree, tree);
95 static int merge_ranges (int *, tree *, tree *, int, tree, tree, int, tree,
97 static tree fold_range_test (tree);
98 static tree unextend (tree, int, int, tree);
99 static tree fold_truthop (enum tree_code, tree, tree, tree);
100 static tree optimize_minmax_comparison (tree);
101 static tree extract_muldiv (tree, tree, enum tree_code, tree);
102 static tree extract_muldiv_1 (tree, tree, enum tree_code, tree);
103 static tree strip_compound_expr (tree, tree);
104 static int multiple_of_p (tree, tree, tree);
105 static tree constant_boolean_node (int, tree);
106 static int count_cond (tree, int);
107 static tree fold_binary_op_with_conditional_arg (enum tree_code, tree, tree,
109 static bool fold_real_zero_addition_p (tree, tree, int);
110 static tree fold_mathfn_compare (enum built_in_function, enum tree_code,
112 static tree fold_inf_compare (enum tree_code, tree, tree, tree);
113 static bool reorder_operands_p (tree, tree);
114 static bool tree_swap_operands_p (tree, tree, bool);
116 static tree fold_negate_const (tree, tree);
117 static tree fold_abs_const (tree, tree);
118 static tree fold_relational_const (enum tree_code, tree, tree, tree);
120 /* The following constants represent a bit based encoding of GCC's
121 comparison operators. This encoding simplifies transformations
122 on relational comparison operators, such as AND and OR. */
123 #define COMPCODE_FALSE 0
124 #define COMPCODE_LT 1
125 #define COMPCODE_EQ 2
126 #define COMPCODE_LE 3
127 #define COMPCODE_GT 4
128 #define COMPCODE_NE 5
129 #define COMPCODE_GE 6
130 #define COMPCODE_TRUE 7
132 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
133 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
134 and SUM1. Then this yields nonzero if overflow occurred during the
137 Overflow occurs if A and B have the same sign, but A and SUM differ in
138 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
140 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
142 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
143 We do that by representing the two-word integer in 4 words, with only
144 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
145 number. The value of the word is LOWPART + HIGHPART * BASE. */
148 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
149 #define HIGHPART(x) \
150 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
151 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
153 /* Unpack a two-word integer into 4 words.
154 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
155 WORDS points to the array of HOST_WIDE_INTs. */
158 encode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT low, HOST_WIDE_INT hi)
160 words[0] = LOWPART (low);
161 words[1] = HIGHPART (low);
162 words[2] = LOWPART (hi);
163 words[3] = HIGHPART (hi);
166 /* Pack an array of 4 words into a two-word integer.
167 WORDS points to the array of words.
168 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
171 decode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT *low,
174 *low = words[0] + words[1] * BASE;
175 *hi = words[2] + words[3] * BASE;
178 /* Make the integer constant T valid for its type by setting to 0 or 1 all
179 the bits in the constant that don't belong in the type.
181 Return 1 if a signed overflow occurs, 0 otherwise. If OVERFLOW is
182 nonzero, a signed overflow has already occurred in calculating T, so
186 force_fit_type (tree t, int overflow)
188 unsigned HOST_WIDE_INT low;
192 if (TREE_CODE (t) == REAL_CST)
194 /* ??? Used to check for overflow here via CHECK_FLOAT_TYPE.
195 Consider doing it via real_convert now. */
199 else if (TREE_CODE (t) != INTEGER_CST)
202 low = TREE_INT_CST_LOW (t);
203 high = TREE_INT_CST_HIGH (t);
205 if (POINTER_TYPE_P (TREE_TYPE (t))
206 || TREE_CODE (TREE_TYPE (t)) == OFFSET_TYPE)
209 prec = TYPE_PRECISION (TREE_TYPE (t));
211 /* First clear all bits that are beyond the type's precision. */
213 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
215 else if (prec > HOST_BITS_PER_WIDE_INT)
216 TREE_INT_CST_HIGH (t)
217 &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
220 TREE_INT_CST_HIGH (t) = 0;
221 if (prec < HOST_BITS_PER_WIDE_INT)
222 TREE_INT_CST_LOW (t) &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
225 /* Unsigned types do not suffer sign extension or overflow unless they
227 if (TYPE_UNSIGNED (TREE_TYPE (t))
228 && ! (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
229 && TYPE_IS_SIZETYPE (TREE_TYPE (t))))
232 /* If the value's sign bit is set, extend the sign. */
233 if (prec != 2 * HOST_BITS_PER_WIDE_INT
234 && (prec > HOST_BITS_PER_WIDE_INT
235 ? 0 != (TREE_INT_CST_HIGH (t)
237 << (prec - HOST_BITS_PER_WIDE_INT - 1)))
238 : 0 != (TREE_INT_CST_LOW (t)
239 & ((unsigned HOST_WIDE_INT) 1 << (prec - 1)))))
241 /* Value is negative:
242 set to 1 all the bits that are outside this type's precision. */
243 if (prec > HOST_BITS_PER_WIDE_INT)
244 TREE_INT_CST_HIGH (t)
245 |= ((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
248 TREE_INT_CST_HIGH (t) = -1;
249 if (prec < HOST_BITS_PER_WIDE_INT)
250 TREE_INT_CST_LOW (t) |= ((unsigned HOST_WIDE_INT) (-1) << prec);
254 /* Return nonzero if signed overflow occurred. */
256 ((overflow | (low ^ TREE_INT_CST_LOW (t)) | (high ^ TREE_INT_CST_HIGH (t)))
260 /* Add two doubleword integers with doubleword result.
261 Each argument is given as two `HOST_WIDE_INT' pieces.
262 One argument is L1 and H1; the other, L2 and H2.
263 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
266 add_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
267 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
268 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
270 unsigned HOST_WIDE_INT l;
274 h = h1 + h2 + (l < l1);
278 return OVERFLOW_SUM_SIGN (h1, h2, h);
281 /* Negate a doubleword integer with doubleword result.
282 Return nonzero if the operation overflows, assuming it's signed.
283 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
284 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
287 neg_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
288 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
294 return (*hv & h1) < 0;
304 /* Multiply two doubleword integers with doubleword result.
305 Return nonzero if the operation overflows, assuming it's signed.
306 Each argument is given as two `HOST_WIDE_INT' pieces.
307 One argument is L1 and H1; the other, L2 and H2.
308 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
311 mul_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
312 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
313 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
315 HOST_WIDE_INT arg1[4];
316 HOST_WIDE_INT arg2[4];
317 HOST_WIDE_INT prod[4 * 2];
318 unsigned HOST_WIDE_INT carry;
320 unsigned HOST_WIDE_INT toplow, neglow;
321 HOST_WIDE_INT tophigh, neghigh;
323 encode (arg1, l1, h1);
324 encode (arg2, l2, h2);
326 memset (prod, 0, sizeof prod);
328 for (i = 0; i < 4; i++)
331 for (j = 0; j < 4; j++)
334 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
335 carry += arg1[i] * arg2[j];
336 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
338 prod[k] = LOWPART (carry);
339 carry = HIGHPART (carry);
344 decode (prod, lv, hv); /* This ignores prod[4] through prod[4*2-1] */
346 /* Check for overflow by calculating the top half of the answer in full;
347 it should agree with the low half's sign bit. */
348 decode (prod + 4, &toplow, &tophigh);
351 neg_double (l2, h2, &neglow, &neghigh);
352 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
356 neg_double (l1, h1, &neglow, &neghigh);
357 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
359 return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
362 /* Shift the doubleword integer in L1, H1 left by COUNT places
363 keeping only PREC bits of result.
364 Shift right if COUNT is negative.
365 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
366 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
369 lshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
370 HOST_WIDE_INT count, unsigned int prec,
371 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv, int arith)
373 unsigned HOST_WIDE_INT signmask;
377 rshift_double (l1, h1, -count, prec, lv, hv, arith);
381 if (SHIFT_COUNT_TRUNCATED)
384 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
386 /* Shifting by the host word size is undefined according to the
387 ANSI standard, so we must handle this as a special case. */
391 else if (count >= HOST_BITS_PER_WIDE_INT)
393 *hv = l1 << (count - HOST_BITS_PER_WIDE_INT);
398 *hv = (((unsigned HOST_WIDE_INT) h1 << count)
399 | (l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
403 /* Sign extend all bits that are beyond the precision. */
405 signmask = -((prec > HOST_BITS_PER_WIDE_INT
406 ? ((unsigned HOST_WIDE_INT) *hv
407 >> (prec - HOST_BITS_PER_WIDE_INT - 1))
408 : (*lv >> (prec - 1))) & 1);
410 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
412 else if (prec >= HOST_BITS_PER_WIDE_INT)
414 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
415 *hv |= signmask << (prec - HOST_BITS_PER_WIDE_INT);
420 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
421 *lv |= signmask << prec;
425 /* Shift the doubleword integer in L1, H1 right by COUNT places
426 keeping only PREC bits of result. COUNT must be positive.
427 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
428 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
431 rshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
432 HOST_WIDE_INT count, unsigned int prec,
433 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
436 unsigned HOST_WIDE_INT signmask;
439 ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
442 if (SHIFT_COUNT_TRUNCATED)
445 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
447 /* Shifting by the host word size is undefined according to the
448 ANSI standard, so we must handle this as a special case. */
452 else if (count >= HOST_BITS_PER_WIDE_INT)
455 *lv = (unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT);
459 *hv = (unsigned HOST_WIDE_INT) h1 >> count;
461 | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
464 /* Zero / sign extend all bits that are beyond the precision. */
466 if (count >= (HOST_WIDE_INT)prec)
471 else if ((prec - count) >= 2 * HOST_BITS_PER_WIDE_INT)
473 else if ((prec - count) >= HOST_BITS_PER_WIDE_INT)
475 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - count - HOST_BITS_PER_WIDE_INT));
476 *hv |= signmask << (prec - count - HOST_BITS_PER_WIDE_INT);
481 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << (prec - count));
482 *lv |= signmask << (prec - count);
486 /* Rotate the doubleword integer in L1, H1 left by COUNT places
487 keeping only PREC bits of result.
488 Rotate right if COUNT is negative.
489 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
492 lrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
493 HOST_WIDE_INT count, unsigned int prec,
494 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
496 unsigned HOST_WIDE_INT s1l, s2l;
497 HOST_WIDE_INT s1h, s2h;
503 lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
504 rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
509 /* Rotate the doubleword integer in L1, H1 left by COUNT places
510 keeping only PREC bits of result. COUNT must be positive.
511 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
514 rrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
515 HOST_WIDE_INT count, unsigned int prec,
516 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
518 unsigned HOST_WIDE_INT s1l, s2l;
519 HOST_WIDE_INT s1h, s2h;
525 rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
526 lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
531 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
532 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
533 CODE is a tree code for a kind of division, one of
534 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
536 It controls how the quotient is rounded to an integer.
537 Return nonzero if the operation overflows.
538 UNS nonzero says do unsigned division. */
541 div_and_round_double (enum tree_code code, int uns,
542 unsigned HOST_WIDE_INT lnum_orig, /* num == numerator == dividend */
543 HOST_WIDE_INT hnum_orig,
544 unsigned HOST_WIDE_INT lden_orig, /* den == denominator == divisor */
545 HOST_WIDE_INT hden_orig,
546 unsigned HOST_WIDE_INT *lquo,
547 HOST_WIDE_INT *hquo, unsigned HOST_WIDE_INT *lrem,
551 HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
552 HOST_WIDE_INT den[4], quo[4];
554 unsigned HOST_WIDE_INT work;
555 unsigned HOST_WIDE_INT carry = 0;
556 unsigned HOST_WIDE_INT lnum = lnum_orig;
557 HOST_WIDE_INT hnum = hnum_orig;
558 unsigned HOST_WIDE_INT lden = lden_orig;
559 HOST_WIDE_INT hden = hden_orig;
562 if (hden == 0 && lden == 0)
563 overflow = 1, lden = 1;
565 /* Calculate quotient sign and convert operands to unsigned. */
571 /* (minimum integer) / (-1) is the only overflow case. */
572 if (neg_double (lnum, hnum, &lnum, &hnum)
573 && ((HOST_WIDE_INT) lden & hden) == -1)
579 neg_double (lden, hden, &lden, &hden);
583 if (hnum == 0 && hden == 0)
584 { /* single precision */
586 /* This unsigned division rounds toward zero. */
592 { /* trivial case: dividend < divisor */
593 /* hden != 0 already checked. */
600 memset (quo, 0, sizeof quo);
602 memset (num, 0, sizeof num); /* to zero 9th element */
603 memset (den, 0, sizeof den);
605 encode (num, lnum, hnum);
606 encode (den, lden, hden);
608 /* Special code for when the divisor < BASE. */
609 if (hden == 0 && lden < (unsigned HOST_WIDE_INT) BASE)
611 /* hnum != 0 already checked. */
612 for (i = 4 - 1; i >= 0; i--)
614 work = num[i] + carry * BASE;
615 quo[i] = work / lden;
621 /* Full double precision division,
622 with thanks to Don Knuth's "Seminumerical Algorithms". */
623 int num_hi_sig, den_hi_sig;
624 unsigned HOST_WIDE_INT quo_est, scale;
626 /* Find the highest nonzero divisor digit. */
627 for (i = 4 - 1;; i--)
634 /* Insure that the first digit of the divisor is at least BASE/2.
635 This is required by the quotient digit estimation algorithm. */
637 scale = BASE / (den[den_hi_sig] + 1);
639 { /* scale divisor and dividend */
641 for (i = 0; i <= 4 - 1; i++)
643 work = (num[i] * scale) + carry;
644 num[i] = LOWPART (work);
645 carry = HIGHPART (work);
650 for (i = 0; i <= 4 - 1; i++)
652 work = (den[i] * scale) + carry;
653 den[i] = LOWPART (work);
654 carry = HIGHPART (work);
655 if (den[i] != 0) den_hi_sig = i;
662 for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--)
664 /* Guess the next quotient digit, quo_est, by dividing the first
665 two remaining dividend digits by the high order quotient digit.
666 quo_est is never low and is at most 2 high. */
667 unsigned HOST_WIDE_INT tmp;
669 num_hi_sig = i + den_hi_sig + 1;
670 work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
671 if (num[num_hi_sig] != den[den_hi_sig])
672 quo_est = work / den[den_hi_sig];
676 /* Refine quo_est so it's usually correct, and at most one high. */
677 tmp = work - quo_est * den[den_hi_sig];
679 && (den[den_hi_sig - 1] * quo_est
680 > (tmp * BASE + num[num_hi_sig - 2])))
683 /* Try QUO_EST as the quotient digit, by multiplying the
684 divisor by QUO_EST and subtracting from the remaining dividend.
685 Keep in mind that QUO_EST is the I - 1st digit. */
688 for (j = 0; j <= den_hi_sig; j++)
690 work = quo_est * den[j] + carry;
691 carry = HIGHPART (work);
692 work = num[i + j] - LOWPART (work);
693 num[i + j] = LOWPART (work);
694 carry += HIGHPART (work) != 0;
697 /* If quo_est was high by one, then num[i] went negative and
698 we need to correct things. */
699 if (num[num_hi_sig] < (HOST_WIDE_INT) carry)
702 carry = 0; /* add divisor back in */
703 for (j = 0; j <= den_hi_sig; j++)
705 work = num[i + j] + den[j] + carry;
706 carry = HIGHPART (work);
707 num[i + j] = LOWPART (work);
710 num [num_hi_sig] += carry;
713 /* Store the quotient digit. */
718 decode (quo, lquo, hquo);
721 /* If result is negative, make it so. */
723 neg_double (*lquo, *hquo, lquo, hquo);
725 /* Compute trial remainder: rem = num - (quo * den) */
726 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
727 neg_double (*lrem, *hrem, lrem, hrem);
728 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
733 case TRUNC_MOD_EXPR: /* round toward zero */
734 case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
738 case FLOOR_MOD_EXPR: /* round toward negative infinity */
739 if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
742 add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
750 case CEIL_MOD_EXPR: /* round toward positive infinity */
751 if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
753 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
761 case ROUND_MOD_EXPR: /* round to closest integer */
763 unsigned HOST_WIDE_INT labs_rem = *lrem;
764 HOST_WIDE_INT habs_rem = *hrem;
765 unsigned HOST_WIDE_INT labs_den = lden, ltwice;
766 HOST_WIDE_INT habs_den = hden, htwice;
768 /* Get absolute values. */
770 neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
772 neg_double (lden, hden, &labs_den, &habs_den);
774 /* If (2 * abs (lrem) >= abs (lden)) */
775 mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
776 labs_rem, habs_rem, <wice, &htwice);
778 if (((unsigned HOST_WIDE_INT) habs_den
779 < (unsigned HOST_WIDE_INT) htwice)
780 || (((unsigned HOST_WIDE_INT) habs_den
781 == (unsigned HOST_WIDE_INT) htwice)
782 && (labs_den < ltwice)))
786 add_double (*lquo, *hquo,
787 (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
790 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
802 /* Compute true remainder: rem = num - (quo * den) */
803 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
804 neg_double (*lrem, *hrem, lrem, hrem);
805 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
809 /* Return true if built-in mathematical function specified by CODE
810 preserves the sign of it argument, i.e. -f(x) == f(-x). */
813 negate_mathfn_p (enum built_in_function code)
837 /* Determine whether an expression T can be cheaply negated using
838 the function negate_expr. */
841 negate_expr_p (tree t)
843 unsigned HOST_WIDE_INT val;
850 type = TREE_TYPE (t);
853 switch (TREE_CODE (t))
856 if (TYPE_UNSIGNED (type) || ! flag_trapv)
859 /* Check that -CST will not overflow type. */
860 prec = TYPE_PRECISION (type);
861 if (prec > HOST_BITS_PER_WIDE_INT)
863 if (TREE_INT_CST_LOW (t) != 0)
865 prec -= HOST_BITS_PER_WIDE_INT;
866 val = TREE_INT_CST_HIGH (t);
869 val = TREE_INT_CST_LOW (t);
870 if (prec < HOST_BITS_PER_WIDE_INT)
871 val &= ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
872 return val != ((unsigned HOST_WIDE_INT) 1 << (prec - 1));
879 return negate_expr_p (TREE_REALPART (t))
880 && negate_expr_p (TREE_IMAGPART (t));
883 if (FLOAT_TYPE_P (type) && !flag_unsafe_math_optimizations)
885 /* -(A + B) -> (-B) - A. */
886 if (negate_expr_p (TREE_OPERAND (t, 1))
887 && reorder_operands_p (TREE_OPERAND (t, 0),
888 TREE_OPERAND (t, 1)))
890 /* -(A + B) -> (-A) - B. */
891 return negate_expr_p (TREE_OPERAND (t, 0));
894 /* We can't turn -(A-B) into B-A when we honor signed zeros. */
895 return (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
896 && reorder_operands_p (TREE_OPERAND (t, 0),
897 TREE_OPERAND (t, 1));
900 if (TYPE_UNSIGNED (TREE_TYPE (t)))
906 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
907 return negate_expr_p (TREE_OPERAND (t, 1))
908 || negate_expr_p (TREE_OPERAND (t, 0));
912 /* Negate -((double)float) as (double)(-float). */
913 if (TREE_CODE (type) == REAL_TYPE)
915 tree tem = strip_float_extensions (t);
917 return negate_expr_p (tem);
922 /* Negate -f(x) as f(-x). */
923 if (negate_mathfn_p (builtin_mathfn_code (t)))
924 return negate_expr_p (TREE_VALUE (TREE_OPERAND (t, 1)));
928 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
929 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
931 tree op1 = TREE_OPERAND (t, 1);
932 if (TREE_INT_CST_HIGH (op1) == 0
933 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
934 == TREE_INT_CST_LOW (op1))
945 /* Given T, an expression, return the negation of T. Allow for T to be
946 null, in which case return null. */
957 type = TREE_TYPE (t);
960 switch (TREE_CODE (t))
963 tem = fold_negate_const (t, type);
964 if (! TREE_OVERFLOW (tem)
965 || TYPE_UNSIGNED (type)
971 tem = fold_negate_const (t, type);
972 /* Two's complement FP formats, such as c4x, may overflow. */
973 if (! TREE_OVERFLOW (tem) || ! flag_trapping_math)
974 return fold_convert (type, tem);
979 tree rpart = negate_expr (TREE_REALPART (t));
980 tree ipart = negate_expr (TREE_IMAGPART (t));
982 if ((TREE_CODE (rpart) == REAL_CST
983 && TREE_CODE (ipart) == REAL_CST)
984 || (TREE_CODE (rpart) == INTEGER_CST
985 && TREE_CODE (ipart) == INTEGER_CST))
986 return build_complex (type, rpart, ipart);
991 return fold_convert (type, TREE_OPERAND (t, 0));
994 if (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
996 /* -(A + B) -> (-B) - A. */
997 if (negate_expr_p (TREE_OPERAND (t, 1))
998 && reorder_operands_p (TREE_OPERAND (t, 0),
999 TREE_OPERAND (t, 1)))
1000 return fold_convert (type,
1001 fold (build (MINUS_EXPR, TREE_TYPE (t),
1002 negate_expr (TREE_OPERAND (t, 1)),
1003 TREE_OPERAND (t, 0))));
1004 /* -(A + B) -> (-A) - B. */
1005 if (negate_expr_p (TREE_OPERAND (t, 0)))
1006 return fold_convert (type,
1007 fold (build (MINUS_EXPR, TREE_TYPE (t),
1008 negate_expr (TREE_OPERAND (t, 0)),
1009 TREE_OPERAND (t, 1))));
1014 /* - (A - B) -> B - A */
1015 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
1016 && reorder_operands_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1)))
1017 return fold_convert (type,
1018 fold (build (MINUS_EXPR, TREE_TYPE (t),
1019 TREE_OPERAND (t, 1),
1020 TREE_OPERAND (t, 0))));
1024 if (TYPE_UNSIGNED (TREE_TYPE (t)))
1030 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
1032 tem = TREE_OPERAND (t, 1);
1033 if (negate_expr_p (tem))
1034 return fold_convert (type,
1035 fold (build (TREE_CODE (t), TREE_TYPE (t),
1036 TREE_OPERAND (t, 0),
1037 negate_expr (tem))));
1038 tem = TREE_OPERAND (t, 0);
1039 if (negate_expr_p (tem))
1040 return fold_convert (type,
1041 fold (build (TREE_CODE (t), TREE_TYPE (t),
1043 TREE_OPERAND (t, 1))));
1048 /* Convert -((double)float) into (double)(-float). */
1049 if (TREE_CODE (type) == REAL_TYPE)
1051 tem = strip_float_extensions (t);
1052 if (tem != t && negate_expr_p (tem))
1053 return fold_convert (type, negate_expr (tem));
1058 /* Negate -f(x) as f(-x). */
1059 if (negate_mathfn_p (builtin_mathfn_code (t))
1060 && negate_expr_p (TREE_VALUE (TREE_OPERAND (t, 1))))
1062 tree fndecl, arg, arglist;
1064 fndecl = get_callee_fndecl (t);
1065 arg = negate_expr (TREE_VALUE (TREE_OPERAND (t, 1)));
1066 arglist = build_tree_list (NULL_TREE, arg);
1067 return build_function_call_expr (fndecl, arglist);
1072 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1073 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
1075 tree op1 = TREE_OPERAND (t, 1);
1076 if (TREE_INT_CST_HIGH (op1) == 0
1077 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
1078 == TREE_INT_CST_LOW (op1))
1080 tree ntype = TYPE_UNSIGNED (type)
1081 ? lang_hooks.types.signed_type (type)
1082 : lang_hooks.types.unsigned_type (type);
1083 tree temp = fold_convert (ntype, TREE_OPERAND (t, 0));
1084 temp = fold (build2 (RSHIFT_EXPR, ntype, temp, op1));
1085 return fold_convert (type, temp);
1094 tem = fold (build1 (NEGATE_EXPR, TREE_TYPE (t), t));
1095 return fold_convert (type, tem);
1098 /* Split a tree IN into a constant, literal and variable parts that could be
1099 combined with CODE to make IN. "constant" means an expression with
1100 TREE_CONSTANT but that isn't an actual constant. CODE must be a
1101 commutative arithmetic operation. Store the constant part into *CONP,
1102 the literal in *LITP and return the variable part. If a part isn't
1103 present, set it to null. If the tree does not decompose in this way,
1104 return the entire tree as the variable part and the other parts as null.
1106 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
1107 case, we negate an operand that was subtracted. Except if it is a
1108 literal for which we use *MINUS_LITP instead.
1110 If NEGATE_P is true, we are negating all of IN, again except a literal
1111 for which we use *MINUS_LITP instead.
1113 If IN is itself a literal or constant, return it as appropriate.
1115 Note that we do not guarantee that any of the three values will be the
1116 same type as IN, but they will have the same signedness and mode. */
1119 split_tree (tree in, enum tree_code code, tree *conp, tree *litp,
1120 tree *minus_litp, int negate_p)
1128 /* Strip any conversions that don't change the machine mode or signedness. */
1129 STRIP_SIGN_NOPS (in);
1131 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST)
1133 else if (TREE_CODE (in) == code
1134 || (! FLOAT_TYPE_P (TREE_TYPE (in))
1135 /* We can associate addition and subtraction together (even
1136 though the C standard doesn't say so) for integers because
1137 the value is not affected. For reals, the value might be
1138 affected, so we can't. */
1139 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
1140 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
1142 tree op0 = TREE_OPERAND (in, 0);
1143 tree op1 = TREE_OPERAND (in, 1);
1144 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
1145 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
1147 /* First see if either of the operands is a literal, then a constant. */
1148 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
1149 *litp = op0, op0 = 0;
1150 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST)
1151 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
1153 if (op0 != 0 && TREE_CONSTANT (op0))
1154 *conp = op0, op0 = 0;
1155 else if (op1 != 0 && TREE_CONSTANT (op1))
1156 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
1158 /* If we haven't dealt with either operand, this is not a case we can
1159 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1160 if (op0 != 0 && op1 != 0)
1165 var = op1, neg_var_p = neg1_p;
1167 /* Now do any needed negations. */
1169 *minus_litp = *litp, *litp = 0;
1171 *conp = negate_expr (*conp);
1173 var = negate_expr (var);
1175 else if (TREE_CONSTANT (in))
1183 *minus_litp = *litp, *litp = 0;
1184 else if (*minus_litp)
1185 *litp = *minus_litp, *minus_litp = 0;
1186 *conp = negate_expr (*conp);
1187 var = negate_expr (var);
1193 /* Re-associate trees split by the above function. T1 and T2 are either
1194 expressions to associate or null. Return the new expression, if any. If
1195 we build an operation, do it in TYPE and with CODE. */
1198 associate_trees (tree t1, tree t2, enum tree_code code, tree type)
1205 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1206 try to fold this since we will have infinite recursion. But do
1207 deal with any NEGATE_EXPRs. */
1208 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
1209 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1211 if (code == PLUS_EXPR)
1213 if (TREE_CODE (t1) == NEGATE_EXPR)
1214 return build (MINUS_EXPR, type, fold_convert (type, t2),
1215 fold_convert (type, TREE_OPERAND (t1, 0)));
1216 else if (TREE_CODE (t2) == NEGATE_EXPR)
1217 return build (MINUS_EXPR, type, fold_convert (type, t1),
1218 fold_convert (type, TREE_OPERAND (t2, 0)));
1220 return build (code, type, fold_convert (type, t1),
1221 fold_convert (type, t2));
1224 return fold (build (code, type, fold_convert (type, t1),
1225 fold_convert (type, t2)));
1228 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1229 to produce a new constant.
1231 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1234 int_const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1236 unsigned HOST_WIDE_INT int1l, int2l;
1237 HOST_WIDE_INT int1h, int2h;
1238 unsigned HOST_WIDE_INT low;
1240 unsigned HOST_WIDE_INT garbagel;
1241 HOST_WIDE_INT garbageh;
1243 tree type = TREE_TYPE (arg1);
1244 int uns = TYPE_UNSIGNED (type);
1246 = (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type));
1248 int no_overflow = 0;
1250 int1l = TREE_INT_CST_LOW (arg1);
1251 int1h = TREE_INT_CST_HIGH (arg1);
1252 int2l = TREE_INT_CST_LOW (arg2);
1253 int2h = TREE_INT_CST_HIGH (arg2);
1258 low = int1l | int2l, hi = int1h | int2h;
1262 low = int1l ^ int2l, hi = int1h ^ int2h;
1266 low = int1l & int2l, hi = int1h & int2h;
1272 /* It's unclear from the C standard whether shifts can overflow.
1273 The following code ignores overflow; perhaps a C standard
1274 interpretation ruling is needed. */
1275 lshift_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1283 lrotate_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1288 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1292 neg_double (int2l, int2h, &low, &hi);
1293 add_double (int1l, int1h, low, hi, &low, &hi);
1294 overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
1298 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1301 case TRUNC_DIV_EXPR:
1302 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1303 case EXACT_DIV_EXPR:
1304 /* This is a shortcut for a common special case. */
1305 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1306 && ! TREE_CONSTANT_OVERFLOW (arg1)
1307 && ! TREE_CONSTANT_OVERFLOW (arg2)
1308 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1310 if (code == CEIL_DIV_EXPR)
1313 low = int1l / int2l, hi = 0;
1317 /* ... fall through ... */
1319 case ROUND_DIV_EXPR:
1320 if (int2h == 0 && int2l == 1)
1322 low = int1l, hi = int1h;
1325 if (int1l == int2l && int1h == int2h
1326 && ! (int1l == 0 && int1h == 0))
1331 overflow = div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
1332 &low, &hi, &garbagel, &garbageh);
1335 case TRUNC_MOD_EXPR:
1336 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1337 /* This is a shortcut for a common special case. */
1338 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1339 && ! TREE_CONSTANT_OVERFLOW (arg1)
1340 && ! TREE_CONSTANT_OVERFLOW (arg2)
1341 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1343 if (code == CEIL_MOD_EXPR)
1345 low = int1l % int2l, hi = 0;
1349 /* ... fall through ... */
1351 case ROUND_MOD_EXPR:
1352 overflow = div_and_round_double (code, uns,
1353 int1l, int1h, int2l, int2h,
1354 &garbagel, &garbageh, &low, &hi);
1360 low = (((unsigned HOST_WIDE_INT) int1h
1361 < (unsigned HOST_WIDE_INT) int2h)
1362 || (((unsigned HOST_WIDE_INT) int1h
1363 == (unsigned HOST_WIDE_INT) int2h)
1366 low = (int1h < int2h
1367 || (int1h == int2h && int1l < int2l));
1369 if (low == (code == MIN_EXPR))
1370 low = int1l, hi = int1h;
1372 low = int2l, hi = int2h;
1379 /* If this is for a sizetype, can be represented as one (signed)
1380 HOST_WIDE_INT word, and doesn't overflow, use size_int since it caches
1383 && ((hi == 0 && (HOST_WIDE_INT) low >= 0)
1384 || (hi == -1 && (HOST_WIDE_INT) low < 0))
1385 && overflow == 0 && ! TREE_OVERFLOW (arg1) && ! TREE_OVERFLOW (arg2))
1386 return size_int_type_wide (low, type);
1389 t = build_int_2 (low, hi);
1390 TREE_TYPE (t) = TREE_TYPE (arg1);
1395 ? (!uns || is_sizetype) && overflow
1396 : (force_fit_type (t, (!uns || is_sizetype) && overflow)
1398 | TREE_OVERFLOW (arg1)
1399 | TREE_OVERFLOW (arg2));
1401 /* If we're doing a size calculation, unsigned arithmetic does overflow.
1402 So check if force_fit_type truncated the value. */
1404 && ! TREE_OVERFLOW (t)
1405 && (TREE_INT_CST_HIGH (t) != hi
1406 || TREE_INT_CST_LOW (t) != low))
1407 TREE_OVERFLOW (t) = 1;
1409 TREE_CONSTANT_OVERFLOW (t) = (TREE_OVERFLOW (t)
1410 | TREE_CONSTANT_OVERFLOW (arg1)
1411 | TREE_CONSTANT_OVERFLOW (arg2));
1415 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1416 constant. We assume ARG1 and ARG2 have the same data type, or at least
1417 are the same kind of constant and the same machine mode.
1419 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1422 const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1427 if (TREE_CODE (arg1) == INTEGER_CST)
1428 return int_const_binop (code, arg1, arg2, notrunc);
1430 if (TREE_CODE (arg1) == REAL_CST)
1432 enum machine_mode mode;
1435 REAL_VALUE_TYPE value;
1438 d1 = TREE_REAL_CST (arg1);
1439 d2 = TREE_REAL_CST (arg2);
1441 type = TREE_TYPE (arg1);
1442 mode = TYPE_MODE (type);
1444 /* Don't perform operation if we honor signaling NaNs and
1445 either operand is a NaN. */
1446 if (HONOR_SNANS (mode)
1447 && (REAL_VALUE_ISNAN (d1) || REAL_VALUE_ISNAN (d2)))
1450 /* Don't perform operation if it would raise a division
1451 by zero exception. */
1452 if (code == RDIV_EXPR
1453 && REAL_VALUES_EQUAL (d2, dconst0)
1454 && (flag_trapping_math || ! MODE_HAS_INFINITIES (mode)))
1457 /* If either operand is a NaN, just return it. Otherwise, set up
1458 for floating-point trap; we return an overflow. */
1459 if (REAL_VALUE_ISNAN (d1))
1461 else if (REAL_VALUE_ISNAN (d2))
1464 REAL_ARITHMETIC (value, code, d1, d2);
1466 t = build_real (type, real_value_truncate (mode, value));
1469 = (force_fit_type (t, 0)
1470 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
1471 TREE_CONSTANT_OVERFLOW (t)
1473 | TREE_CONSTANT_OVERFLOW (arg1)
1474 | TREE_CONSTANT_OVERFLOW (arg2);
1477 if (TREE_CODE (arg1) == COMPLEX_CST)
1479 tree type = TREE_TYPE (arg1);
1480 tree r1 = TREE_REALPART (arg1);
1481 tree i1 = TREE_IMAGPART (arg1);
1482 tree r2 = TREE_REALPART (arg2);
1483 tree i2 = TREE_IMAGPART (arg2);
1489 t = build_complex (type,
1490 const_binop (PLUS_EXPR, r1, r2, notrunc),
1491 const_binop (PLUS_EXPR, i1, i2, notrunc));
1495 t = build_complex (type,
1496 const_binop (MINUS_EXPR, r1, r2, notrunc),
1497 const_binop (MINUS_EXPR, i1, i2, notrunc));
1501 t = build_complex (type,
1502 const_binop (MINUS_EXPR,
1503 const_binop (MULT_EXPR,
1505 const_binop (MULT_EXPR,
1508 const_binop (PLUS_EXPR,
1509 const_binop (MULT_EXPR,
1511 const_binop (MULT_EXPR,
1519 = const_binop (PLUS_EXPR,
1520 const_binop (MULT_EXPR, r2, r2, notrunc),
1521 const_binop (MULT_EXPR, i2, i2, notrunc),
1524 t = build_complex (type,
1526 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1527 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1528 const_binop (PLUS_EXPR,
1529 const_binop (MULT_EXPR, r1, r2,
1531 const_binop (MULT_EXPR, i1, i2,
1534 magsquared, notrunc),
1536 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1537 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1538 const_binop (MINUS_EXPR,
1539 const_binop (MULT_EXPR, i1, r2,
1541 const_binop (MULT_EXPR, r1, i2,
1544 magsquared, notrunc));
1556 /* These are the hash table functions for the hash table of INTEGER_CST
1557 nodes of a sizetype. */
1559 /* Return the hash code code X, an INTEGER_CST. */
1562 size_htab_hash (const void *x)
1566 return (TREE_INT_CST_HIGH (t) ^ TREE_INT_CST_LOW (t)
1567 ^ htab_hash_pointer (TREE_TYPE (t))
1568 ^ (TREE_OVERFLOW (t) << 20));
1571 /* Return nonzero if the value represented by *X (an INTEGER_CST tree node)
1572 is the same as that given by *Y, which is the same. */
1575 size_htab_eq (const void *x, const void *y)
1580 return (TREE_INT_CST_HIGH (xt) == TREE_INT_CST_HIGH (yt)
1581 && TREE_INT_CST_LOW (xt) == TREE_INT_CST_LOW (yt)
1582 && TREE_TYPE (xt) == TREE_TYPE (yt)
1583 && TREE_OVERFLOW (xt) == TREE_OVERFLOW (yt));
1586 /* Return an INTEGER_CST with value whose low-order HOST_BITS_PER_WIDE_INT
1587 bits are given by NUMBER and of the sizetype represented by KIND. */
1590 size_int_wide (HOST_WIDE_INT number, enum size_type_kind kind)
1592 return size_int_type_wide (number, sizetype_tab[(int) kind]);
1595 /* Likewise, but the desired type is specified explicitly. */
1597 static GTY (()) tree new_const;
1598 static GTY ((if_marked ("ggc_marked_p"), param_is (union tree_node)))
1602 size_int_type_wide (HOST_WIDE_INT number, tree type)
1608 size_htab = htab_create_ggc (1024, size_htab_hash, size_htab_eq, NULL);
1609 new_const = make_node (INTEGER_CST);
1612 /* Adjust NEW_CONST to be the constant we want. If it's already in the
1613 hash table, we return the value from the hash table. Otherwise, we
1614 place that in the hash table and make a new node for the next time. */
1615 TREE_INT_CST_LOW (new_const) = number;
1616 TREE_INT_CST_HIGH (new_const) = number < 0 ? -1 : 0;
1617 TREE_TYPE (new_const) = type;
1618 TREE_OVERFLOW (new_const) = TREE_CONSTANT_OVERFLOW (new_const)
1619 = force_fit_type (new_const, 0);
1621 slot = htab_find_slot (size_htab, new_const, INSERT);
1627 new_const = make_node (INTEGER_CST);
1631 return (tree) *slot;
1634 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1635 is a tree code. The type of the result is taken from the operands.
1636 Both must be the same type integer type and it must be a size type.
1637 If the operands are constant, so is the result. */
1640 size_binop (enum tree_code code, tree arg0, tree arg1)
1642 tree type = TREE_TYPE (arg0);
1644 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1645 || type != TREE_TYPE (arg1))
1648 /* Handle the special case of two integer constants faster. */
1649 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1651 /* And some specific cases even faster than that. */
1652 if (code == PLUS_EXPR && integer_zerop (arg0))
1654 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1655 && integer_zerop (arg1))
1657 else if (code == MULT_EXPR && integer_onep (arg0))
1660 /* Handle general case of two integer constants. */
1661 return int_const_binop (code, arg0, arg1, 0);
1664 if (arg0 == error_mark_node || arg1 == error_mark_node)
1665 return error_mark_node;
1667 return fold (build (code, type, arg0, arg1));
1670 /* Given two values, either both of sizetype or both of bitsizetype,
1671 compute the difference between the two values. Return the value
1672 in signed type corresponding to the type of the operands. */
1675 size_diffop (tree arg0, tree arg1)
1677 tree type = TREE_TYPE (arg0);
1680 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1681 || type != TREE_TYPE (arg1))
1684 /* If the type is already signed, just do the simple thing. */
1685 if (!TYPE_UNSIGNED (type))
1686 return size_binop (MINUS_EXPR, arg0, arg1);
1688 ctype = (type == bitsizetype || type == ubitsizetype
1689 ? sbitsizetype : ssizetype);
1691 /* If either operand is not a constant, do the conversions to the signed
1692 type and subtract. The hardware will do the right thing with any
1693 overflow in the subtraction. */
1694 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
1695 return size_binop (MINUS_EXPR, fold_convert (ctype, arg0),
1696 fold_convert (ctype, arg1));
1698 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
1699 Otherwise, subtract the other way, convert to CTYPE (we know that can't
1700 overflow) and negate (which can't either). Special-case a result
1701 of zero while we're here. */
1702 if (tree_int_cst_equal (arg0, arg1))
1703 return fold_convert (ctype, integer_zero_node);
1704 else if (tree_int_cst_lt (arg1, arg0))
1705 return fold_convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
1707 return size_binop (MINUS_EXPR, fold_convert (ctype, integer_zero_node),
1708 fold_convert (ctype, size_binop (MINUS_EXPR,
1713 /* Attempt to fold type conversion operation CODE of expression ARG1 to
1714 type TYPE. If no simplification can be done return NULL_TREE. */
1717 fold_convert_const (enum tree_code code, tree type, tree arg1)
1722 if (TREE_TYPE (arg1) == type)
1725 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
1727 if (TREE_CODE (arg1) == INTEGER_CST)
1729 /* If we would build a constant wider than GCC supports,
1730 leave the conversion unfolded. */
1731 if (TYPE_PRECISION (type) > 2 * HOST_BITS_PER_WIDE_INT)
1734 /* If we are trying to make a sizetype for a small integer, use
1735 size_int to pick up cached types to reduce duplicate nodes. */
1736 if (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type)
1737 && !TREE_CONSTANT_OVERFLOW (arg1)
1738 && compare_tree_int (arg1, 10000) < 0)
1739 return size_int_type_wide (TREE_INT_CST_LOW (arg1), type);
1741 /* Given an integer constant, make new constant with new type,
1742 appropriately sign-extended or truncated. */
1743 t = build_int_2 (TREE_INT_CST_LOW (arg1),
1744 TREE_INT_CST_HIGH (arg1));
1745 TREE_TYPE (t) = type;
1746 /* Indicate an overflow if (1) ARG1 already overflowed,
1747 or (2) force_fit_type indicates an overflow.
1748 Tell force_fit_type that an overflow has already occurred
1749 if ARG1 is a too-large unsigned value and T is signed.
1750 But don't indicate an overflow if converting a pointer. */
1752 = ((force_fit_type (t,
1753 (TREE_INT_CST_HIGH (arg1) < 0
1754 && (TYPE_UNSIGNED (type)
1755 < TYPE_UNSIGNED (TREE_TYPE (arg1)))))
1756 && ! POINTER_TYPE_P (TREE_TYPE (arg1)))
1757 || TREE_OVERFLOW (arg1));
1758 TREE_CONSTANT_OVERFLOW (t)
1759 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1762 else if (TREE_CODE (arg1) == REAL_CST)
1764 /* The following code implements the floating point to integer
1765 conversion rules required by the Java Language Specification,
1766 that IEEE NaNs are mapped to zero and values that overflow
1767 the target precision saturate, i.e. values greater than
1768 INT_MAX are mapped to INT_MAX, and values less than INT_MIN
1769 are mapped to INT_MIN. These semantics are allowed by the
1770 C and C++ standards that simply state that the behavior of
1771 FP-to-integer conversion is unspecified upon overflow. */
1773 HOST_WIDE_INT high, low;
1776 REAL_VALUE_TYPE x = TREE_REAL_CST (arg1);
1780 case FIX_TRUNC_EXPR:
1781 real_trunc (&r, VOIDmode, &x);
1785 real_ceil (&r, VOIDmode, &x);
1788 case FIX_FLOOR_EXPR:
1789 real_floor (&r, VOIDmode, &x);
1796 /* If R is NaN, return zero and show we have an overflow. */
1797 if (REAL_VALUE_ISNAN (r))
1804 /* See if R is less than the lower bound or greater than the
1809 tree lt = TYPE_MIN_VALUE (type);
1810 REAL_VALUE_TYPE l = real_value_from_int_cst (NULL_TREE, lt);
1811 if (REAL_VALUES_LESS (r, l))
1814 high = TREE_INT_CST_HIGH (lt);
1815 low = TREE_INT_CST_LOW (lt);
1821 tree ut = TYPE_MAX_VALUE (type);
1824 REAL_VALUE_TYPE u = real_value_from_int_cst (NULL_TREE, ut);
1825 if (REAL_VALUES_LESS (u, r))
1828 high = TREE_INT_CST_HIGH (ut);
1829 low = TREE_INT_CST_LOW (ut);
1835 REAL_VALUE_TO_INT (&low, &high, r);
1837 t = build_int_2 (low, high);
1838 TREE_TYPE (t) = type;
1840 = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
1841 TREE_CONSTANT_OVERFLOW (t)
1842 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1846 else if (TREE_CODE (type) == REAL_TYPE)
1848 if (TREE_CODE (arg1) == INTEGER_CST)
1849 return build_real_from_int_cst (type, arg1);
1850 if (TREE_CODE (arg1) == REAL_CST)
1852 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
1854 /* We make a copy of ARG1 so that we don't modify an
1855 existing constant tree. */
1856 t = copy_node (arg1);
1857 TREE_TYPE (t) = type;
1861 t = build_real (type,
1862 real_value_truncate (TYPE_MODE (type),
1863 TREE_REAL_CST (arg1)));
1866 = TREE_OVERFLOW (arg1) | force_fit_type (t, 0);
1867 TREE_CONSTANT_OVERFLOW (t)
1868 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1875 /* Convert expression ARG to type TYPE. Used by the middle-end for
1876 simple conversions in preference to calling the front-end's convert. */
1879 fold_convert (tree type, tree arg)
1881 tree orig = TREE_TYPE (arg);
1887 if (TREE_CODE (arg) == ERROR_MARK
1888 || TREE_CODE (type) == ERROR_MARK
1889 || TREE_CODE (orig) == ERROR_MARK)
1890 return error_mark_node;
1892 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig))
1893 return fold (build1 (NOP_EXPR, type, arg));
1895 if (INTEGRAL_TYPE_P (type) || POINTER_TYPE_P (type))
1897 if (TREE_CODE (arg) == INTEGER_CST)
1899 tem = fold_convert_const (NOP_EXPR, type, arg);
1900 if (tem != NULL_TREE)
1903 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig))
1904 return fold (build1 (NOP_EXPR, type, arg));
1905 if (TREE_CODE (orig) == COMPLEX_TYPE)
1907 tem = fold (build1 (REALPART_EXPR, TREE_TYPE (orig), arg));
1908 return fold_convert (type, tem);
1910 if (TREE_CODE (orig) == VECTOR_TYPE
1911 && GET_MODE_SIZE (TYPE_MODE (type))
1912 == GET_MODE_SIZE (TYPE_MODE (orig)))
1913 return fold (build1 (NOP_EXPR, type, arg));
1915 else if (TREE_CODE (type) == REAL_TYPE)
1917 if (TREE_CODE (arg) == INTEGER_CST)
1919 tem = fold_convert_const (FLOAT_EXPR, type, arg);
1920 if (tem != NULL_TREE)
1923 else if (TREE_CODE (arg) == REAL_CST)
1925 tem = fold_convert_const (NOP_EXPR, type, arg);
1926 if (tem != NULL_TREE)
1930 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig))
1931 return fold (build1 (FLOAT_EXPR, type, arg));
1932 if (TREE_CODE (orig) == REAL_TYPE)
1933 return fold (build1 (flag_float_store ? CONVERT_EXPR : NOP_EXPR,
1935 if (TREE_CODE (orig) == COMPLEX_TYPE)
1937 tem = fold (build1 (REALPART_EXPR, TREE_TYPE (orig), arg));
1938 return fold_convert (type, tem);
1941 else if (TREE_CODE (type) == COMPLEX_TYPE)
1943 if (INTEGRAL_TYPE_P (orig)
1944 || POINTER_TYPE_P (orig)
1945 || TREE_CODE (orig) == REAL_TYPE)
1946 return build (COMPLEX_EXPR, type,
1947 fold_convert (TREE_TYPE (type), arg),
1948 fold_convert (TREE_TYPE (type), integer_zero_node));
1949 if (TREE_CODE (orig) == COMPLEX_TYPE)
1953 if (TREE_CODE (arg) == COMPLEX_EXPR)
1955 rpart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 0));
1956 ipart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 1));
1957 return fold (build (COMPLEX_EXPR, type, rpart, ipart));
1960 arg = save_expr (arg);
1961 rpart = fold (build1 (REALPART_EXPR, TREE_TYPE (orig), arg));
1962 ipart = fold (build1 (IMAGPART_EXPR, TREE_TYPE (orig), arg));
1963 rpart = fold_convert (TREE_TYPE (type), rpart);
1964 ipart = fold_convert (TREE_TYPE (type), ipart);
1965 return fold (build (COMPLEX_EXPR, type, rpart, ipart));
1968 else if (TREE_CODE (type) == VECTOR_TYPE)
1970 if ((INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig))
1971 && GET_MODE_SIZE (TYPE_MODE (type))
1972 == GET_MODE_SIZE (TYPE_MODE (orig)))
1973 return fold (build1 (NOP_EXPR, type, arg));
1974 if (TREE_CODE (orig) == VECTOR_TYPE
1975 && GET_MODE_SIZE (TYPE_MODE (type))
1976 == GET_MODE_SIZE (TYPE_MODE (orig)))
1977 return fold (build1 (NOP_EXPR, type, arg));
1979 else if (VOID_TYPE_P (type))
1980 return fold (build1 (CONVERT_EXPR, type, arg));
1984 /* Return an expr equal to X but certainly not valid as an lvalue. */
1991 /* These things are certainly not lvalues. */
1992 if (TREE_CODE (x) == NON_LVALUE_EXPR
1993 || TREE_CODE (x) == INTEGER_CST
1994 || TREE_CODE (x) == REAL_CST
1995 || TREE_CODE (x) == STRING_CST
1996 || TREE_CODE (x) == ADDR_EXPR)
1999 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
2000 TREE_CONSTANT (result) = TREE_CONSTANT (x);
2004 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
2005 Zero means allow extended lvalues. */
2007 int pedantic_lvalues;
2009 /* When pedantic, return an expr equal to X but certainly not valid as a
2010 pedantic lvalue. Otherwise, return X. */
2013 pedantic_non_lvalue (tree x)
2015 if (pedantic_lvalues)
2016 return non_lvalue (x);
2021 /* Given a tree comparison code, return the code that is the logical inverse
2022 of the given code. It is not safe to do this for floating-point
2023 comparisons, except for NE_EXPR and EQ_EXPR. */
2025 static enum tree_code
2026 invert_tree_comparison (enum tree_code code)
2047 /* Similar, but return the comparison that results if the operands are
2048 swapped. This is safe for floating-point. */
2050 static enum tree_code
2051 swap_tree_comparison (enum tree_code code)
2072 /* Convert a comparison tree code from an enum tree_code representation
2073 into a compcode bit-based encoding. This function is the inverse of
2074 compcode_to_comparison. */
2077 comparison_to_compcode (enum tree_code code)
2098 /* Convert a compcode bit-based encoding of a comparison operator back
2099 to GCC's enum tree_code representation. This function is the
2100 inverse of comparison_to_compcode. */
2102 static enum tree_code
2103 compcode_to_comparison (int code)
2124 /* Return nonzero if CODE is a tree code that represents a truth value. */
2127 truth_value_p (enum tree_code code)
2129 return (TREE_CODE_CLASS (code) == '<'
2130 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2131 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2132 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
2135 /* Return nonzero if two operands (typically of the same tree node)
2136 are necessarily equal. If either argument has side-effects this
2137 function returns zero.
2139 If ONLY_CONST is nonzero, only return nonzero for constants.
2140 This function tests whether the operands are indistinguishable;
2141 it does not test whether they are equal using C's == operation.
2142 The distinction is important for IEEE floating point, because
2143 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2144 (2) two NaNs may be indistinguishable, but NaN!=NaN.
2146 If ONLY_CONST is zero, a VAR_DECL is considered equal to itself
2147 even though it may hold multiple values during a function.
2148 This is because a GCC tree node guarantees that nothing else is
2149 executed between the evaluation of its "operands" (which may often
2150 be evaluated in arbitrary order). Hence if the operands themselves
2151 don't side-effect, the VAR_DECLs, PARM_DECLs etc... must hold the
2152 same value in each operand/subexpression. Hence a zero value for
2153 ONLY_CONST assumes isochronic (or instantaneous) tree equivalence.
2154 If comparing arbitrary expression trees, such as from different
2155 statements, ONLY_CONST must usually be nonzero. */
2158 operand_equal_p (tree arg0, tree arg1, int only_const)
2162 /* If either is ERROR_MARK, they aren't equal. */
2163 if (TREE_CODE (arg0) == ERROR_MARK || TREE_CODE (arg1) == ERROR_MARK)
2166 /* If both types don't have the same signedness, then we can't consider
2167 them equal. We must check this before the STRIP_NOPS calls
2168 because they may change the signedness of the arguments. */
2169 if (TYPE_UNSIGNED (TREE_TYPE (arg0)) != TYPE_UNSIGNED (TREE_TYPE (arg1)))
2175 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2176 /* This is needed for conversions and for COMPONENT_REF.
2177 Might as well play it safe and always test this. */
2178 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
2179 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
2180 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
2183 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
2184 We don't care about side effects in that case because the SAVE_EXPR
2185 takes care of that for us. In all other cases, two expressions are
2186 equal if they have no side effects. If we have two identical
2187 expressions with side effects that should be treated the same due
2188 to the only side effects being identical SAVE_EXPR's, that will
2189 be detected in the recursive calls below. */
2190 if (arg0 == arg1 && ! only_const
2191 && (TREE_CODE (arg0) == SAVE_EXPR
2192 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
2195 /* Next handle constant cases, those for which we can return 1 even
2196 if ONLY_CONST is set. */
2197 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
2198 switch (TREE_CODE (arg0))
2201 return (! TREE_CONSTANT_OVERFLOW (arg0)
2202 && ! TREE_CONSTANT_OVERFLOW (arg1)
2203 && tree_int_cst_equal (arg0, arg1));
2206 return (! TREE_CONSTANT_OVERFLOW (arg0)
2207 && ! TREE_CONSTANT_OVERFLOW (arg1)
2208 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
2209 TREE_REAL_CST (arg1)));
2215 if (TREE_CONSTANT_OVERFLOW (arg0)
2216 || TREE_CONSTANT_OVERFLOW (arg1))
2219 v1 = TREE_VECTOR_CST_ELTS (arg0);
2220 v2 = TREE_VECTOR_CST_ELTS (arg1);
2223 if (!operand_equal_p (TREE_VALUE (v1), TREE_VALUE (v2),
2226 v1 = TREE_CHAIN (v1);
2227 v2 = TREE_CHAIN (v2);
2234 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
2236 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
2240 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
2241 && ! memcmp (TREE_STRING_POINTER (arg0),
2242 TREE_STRING_POINTER (arg1),
2243 TREE_STRING_LENGTH (arg0)));
2246 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
2255 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
2258 /* Two conversions are equal only if signedness and modes match. */
2259 if ((TREE_CODE (arg0) == NOP_EXPR || TREE_CODE (arg0) == CONVERT_EXPR)
2260 && (TYPE_UNSIGNED (TREE_TYPE (arg0))
2261 != TYPE_UNSIGNED (TREE_TYPE (arg1))))
2264 return operand_equal_p (TREE_OPERAND (arg0, 0),
2265 TREE_OPERAND (arg1, 0), 0);
2269 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0)
2270 && operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1),
2274 /* For commutative ops, allow the other order. */
2275 return (commutative_tree_code (TREE_CODE (arg0))
2276 && operand_equal_p (TREE_OPERAND (arg0, 0),
2277 TREE_OPERAND (arg1, 1), 0)
2278 && operand_equal_p (TREE_OPERAND (arg0, 1),
2279 TREE_OPERAND (arg1, 0), 0));
2282 /* If either of the pointer (or reference) expressions we are
2283 dereferencing contain a side effect, these cannot be equal. */
2284 if (TREE_SIDE_EFFECTS (arg0)
2285 || TREE_SIDE_EFFECTS (arg1))
2288 switch (TREE_CODE (arg0))
2291 return operand_equal_p (TREE_OPERAND (arg0, 0),
2292 TREE_OPERAND (arg1, 0), 0);
2296 case ARRAY_RANGE_REF:
2297 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2298 TREE_OPERAND (arg1, 0), 0)
2299 && operand_equal_p (TREE_OPERAND (arg0, 1),
2300 TREE_OPERAND (arg1, 1), 0));
2303 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2304 TREE_OPERAND (arg1, 0), 0)
2305 && operand_equal_p (TREE_OPERAND (arg0, 1),
2306 TREE_OPERAND (arg1, 1), 0)
2307 && operand_equal_p (TREE_OPERAND (arg0, 2),
2308 TREE_OPERAND (arg1, 2), 0));
2314 switch (TREE_CODE (arg0))
2317 case TRUTH_NOT_EXPR:
2318 return operand_equal_p (TREE_OPERAND (arg0, 0),
2319 TREE_OPERAND (arg1, 0), 0);
2322 return rtx_equal_p (RTL_EXPR_RTL (arg0), RTL_EXPR_RTL (arg1));
2325 /* If the CALL_EXPRs call different functions, then they
2326 clearly can not be equal. */
2327 if (! operand_equal_p (TREE_OPERAND (arg0, 0),
2328 TREE_OPERAND (arg1, 0), 0))
2331 /* Only consider const functions equivalent. */
2332 fndecl = get_callee_fndecl (arg0);
2333 if (fndecl == NULL_TREE
2334 || ! (flags_from_decl_or_type (fndecl) & ECF_CONST))
2337 /* Now see if all the arguments are the same. operand_equal_p
2338 does not handle TREE_LIST, so we walk the operands here
2339 feeding them to operand_equal_p. */
2340 arg0 = TREE_OPERAND (arg0, 1);
2341 arg1 = TREE_OPERAND (arg1, 1);
2342 while (arg0 && arg1)
2344 if (! operand_equal_p (TREE_VALUE (arg0), TREE_VALUE (arg1), 0))
2347 arg0 = TREE_CHAIN (arg0);
2348 arg1 = TREE_CHAIN (arg1);
2351 /* If we get here and both argument lists are exhausted
2352 then the CALL_EXPRs are equal. */
2353 return ! (arg0 || arg1);
2360 /* Consider __builtin_sqrt equal to sqrt. */
2361 return TREE_CODE (arg0) == FUNCTION_DECL
2362 && DECL_BUILT_IN (arg0) && DECL_BUILT_IN (arg1)
2363 && DECL_BUILT_IN_CLASS (arg0) == DECL_BUILT_IN_CLASS (arg1)
2364 && DECL_FUNCTION_CODE (arg0) == DECL_FUNCTION_CODE (arg1);
2371 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2372 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2374 When in doubt, return 0. */
2377 operand_equal_for_comparison_p (tree arg0, tree arg1, tree other)
2379 int unsignedp1, unsignedpo;
2380 tree primarg0, primarg1, primother;
2381 unsigned int correct_width;
2383 if (operand_equal_p (arg0, arg1, 0))
2386 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
2387 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
2390 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2391 and see if the inner values are the same. This removes any
2392 signedness comparison, which doesn't matter here. */
2393 primarg0 = arg0, primarg1 = arg1;
2394 STRIP_NOPS (primarg0);
2395 STRIP_NOPS (primarg1);
2396 if (operand_equal_p (primarg0, primarg1, 0))
2399 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2400 actual comparison operand, ARG0.
2402 First throw away any conversions to wider types
2403 already present in the operands. */
2405 primarg1 = get_narrower (arg1, &unsignedp1);
2406 primother = get_narrower (other, &unsignedpo);
2408 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
2409 if (unsignedp1 == unsignedpo
2410 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
2411 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
2413 tree type = TREE_TYPE (arg0);
2415 /* Make sure shorter operand is extended the right way
2416 to match the longer operand. */
2417 primarg1 = fold_convert (lang_hooks.types.signed_or_unsigned_type
2418 (unsignedp1, TREE_TYPE (primarg1)), primarg1);
2420 if (operand_equal_p (arg0, fold_convert (type, primarg1), 0))
2427 /* See if ARG is an expression that is either a comparison or is performing
2428 arithmetic on comparisons. The comparisons must only be comparing
2429 two different values, which will be stored in *CVAL1 and *CVAL2; if
2430 they are nonzero it means that some operands have already been found.
2431 No variables may be used anywhere else in the expression except in the
2432 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2433 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2435 If this is true, return 1. Otherwise, return zero. */
2438 twoval_comparison_p (tree arg, tree *cval1, tree *cval2, int *save_p)
2440 enum tree_code code = TREE_CODE (arg);
2441 char class = TREE_CODE_CLASS (code);
2443 /* We can handle some of the 'e' cases here. */
2444 if (class == 'e' && code == TRUTH_NOT_EXPR)
2446 else if (class == 'e'
2447 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
2448 || code == COMPOUND_EXPR))
2451 else if (class == 'e' && code == SAVE_EXPR && SAVE_EXPR_RTL (arg) == 0
2452 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
2454 /* If we've already found a CVAL1 or CVAL2, this expression is
2455 two complex to handle. */
2456 if (*cval1 || *cval2)
2466 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
2469 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
2470 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2471 cval1, cval2, save_p));
2477 if (code == COND_EXPR)
2478 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
2479 cval1, cval2, save_p)
2480 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2481 cval1, cval2, save_p)
2482 && twoval_comparison_p (TREE_OPERAND (arg, 2),
2483 cval1, cval2, save_p));
2487 /* First see if we can handle the first operand, then the second. For
2488 the second operand, we know *CVAL1 can't be zero. It must be that
2489 one side of the comparison is each of the values; test for the
2490 case where this isn't true by failing if the two operands
2493 if (operand_equal_p (TREE_OPERAND (arg, 0),
2494 TREE_OPERAND (arg, 1), 0))
2498 *cval1 = TREE_OPERAND (arg, 0);
2499 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
2501 else if (*cval2 == 0)
2502 *cval2 = TREE_OPERAND (arg, 0);
2503 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
2508 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
2510 else if (*cval2 == 0)
2511 *cval2 = TREE_OPERAND (arg, 1);
2512 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
2524 /* ARG is a tree that is known to contain just arithmetic operations and
2525 comparisons. Evaluate the operations in the tree substituting NEW0 for
2526 any occurrence of OLD0 as an operand of a comparison and likewise for
2530 eval_subst (tree arg, tree old0, tree new0, tree old1, tree new1)
2532 tree type = TREE_TYPE (arg);
2533 enum tree_code code = TREE_CODE (arg);
2534 char class = TREE_CODE_CLASS (code);
2536 /* We can handle some of the 'e' cases here. */
2537 if (class == 'e' && code == TRUTH_NOT_EXPR)
2539 else if (class == 'e'
2540 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2546 return fold (build1 (code, type,
2547 eval_subst (TREE_OPERAND (arg, 0),
2548 old0, new0, old1, new1)));
2551 return fold (build (code, type,
2552 eval_subst (TREE_OPERAND (arg, 0),
2553 old0, new0, old1, new1),
2554 eval_subst (TREE_OPERAND (arg, 1),
2555 old0, new0, old1, new1)));
2561 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
2564 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
2567 return fold (build (code, type,
2568 eval_subst (TREE_OPERAND (arg, 0),
2569 old0, new0, old1, new1),
2570 eval_subst (TREE_OPERAND (arg, 1),
2571 old0, new0, old1, new1),
2572 eval_subst (TREE_OPERAND (arg, 2),
2573 old0, new0, old1, new1)));
2577 /* Fall through - ??? */
2581 tree arg0 = TREE_OPERAND (arg, 0);
2582 tree arg1 = TREE_OPERAND (arg, 1);
2584 /* We need to check both for exact equality and tree equality. The
2585 former will be true if the operand has a side-effect. In that
2586 case, we know the operand occurred exactly once. */
2588 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
2590 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
2593 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
2595 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
2598 return fold (build (code, type, arg0, arg1));
2606 /* Return a tree for the case when the result of an expression is RESULT
2607 converted to TYPE and OMITTED was previously an operand of the expression
2608 but is now not needed (e.g., we folded OMITTED * 0).
2610 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2611 the conversion of RESULT to TYPE. */
2614 omit_one_operand (tree type, tree result, tree omitted)
2616 tree t = fold_convert (type, result);
2618 if (TREE_SIDE_EFFECTS (omitted))
2619 return build (COMPOUND_EXPR, type, omitted, t);
2621 return non_lvalue (t);
2624 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2627 pedantic_omit_one_operand (tree type, tree result, tree omitted)
2629 tree t = fold_convert (type, result);
2631 if (TREE_SIDE_EFFECTS (omitted))
2632 return build (COMPOUND_EXPR, type, omitted, t);
2634 return pedantic_non_lvalue (t);
2637 /* Return a simplified tree node for the truth-negation of ARG. This
2638 never alters ARG itself. We assume that ARG is an operation that
2639 returns a truth value (0 or 1). */
2642 invert_truthvalue (tree arg)
2644 tree type = TREE_TYPE (arg);
2645 enum tree_code code = TREE_CODE (arg);
2647 if (code == ERROR_MARK)
2650 /* If this is a comparison, we can simply invert it, except for
2651 floating-point non-equality comparisons, in which case we just
2652 enclose a TRUTH_NOT_EXPR around what we have. */
2654 if (TREE_CODE_CLASS (code) == '<')
2656 if (FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg, 0)))
2657 && !flag_unsafe_math_optimizations
2660 return build1 (TRUTH_NOT_EXPR, type, arg);
2661 else if (code == UNORDERED_EXPR
2662 || code == ORDERED_EXPR
2663 || code == UNEQ_EXPR
2664 || code == UNLT_EXPR
2665 || code == UNLE_EXPR
2666 || code == UNGT_EXPR
2667 || code == UNGE_EXPR)
2668 return build1 (TRUTH_NOT_EXPR, type, arg);
2670 return build (invert_tree_comparison (code), type,
2671 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
2677 return fold_convert (type, build_int_2 (integer_zerop (arg), 0));
2679 case TRUTH_AND_EXPR:
2680 return build (TRUTH_OR_EXPR, type,
2681 invert_truthvalue (TREE_OPERAND (arg, 0)),
2682 invert_truthvalue (TREE_OPERAND (arg, 1)));
2685 return build (TRUTH_AND_EXPR, type,
2686 invert_truthvalue (TREE_OPERAND (arg, 0)),
2687 invert_truthvalue (TREE_OPERAND (arg, 1)));
2689 case TRUTH_XOR_EXPR:
2690 /* Here we can invert either operand. We invert the first operand
2691 unless the second operand is a TRUTH_NOT_EXPR in which case our
2692 result is the XOR of the first operand with the inside of the
2693 negation of the second operand. */
2695 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
2696 return build (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
2697 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
2699 return build (TRUTH_XOR_EXPR, type,
2700 invert_truthvalue (TREE_OPERAND (arg, 0)),
2701 TREE_OPERAND (arg, 1));
2703 case TRUTH_ANDIF_EXPR:
2704 return build (TRUTH_ORIF_EXPR, type,
2705 invert_truthvalue (TREE_OPERAND (arg, 0)),
2706 invert_truthvalue (TREE_OPERAND (arg, 1)));
2708 case TRUTH_ORIF_EXPR:
2709 return build (TRUTH_ANDIF_EXPR, type,
2710 invert_truthvalue (TREE_OPERAND (arg, 0)),
2711 invert_truthvalue (TREE_OPERAND (arg, 1)));
2713 case TRUTH_NOT_EXPR:
2714 return TREE_OPERAND (arg, 0);
2717 return build (COND_EXPR, type, TREE_OPERAND (arg, 0),
2718 invert_truthvalue (TREE_OPERAND (arg, 1)),
2719 invert_truthvalue (TREE_OPERAND (arg, 2)));
2722 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
2723 invert_truthvalue (TREE_OPERAND (arg, 1)));
2725 case NON_LVALUE_EXPR:
2726 return invert_truthvalue (TREE_OPERAND (arg, 0));
2731 return build1 (TREE_CODE (arg), type,
2732 invert_truthvalue (TREE_OPERAND (arg, 0)));
2735 if (!integer_onep (TREE_OPERAND (arg, 1)))
2737 return build (EQ_EXPR, type, arg,
2738 fold_convert (type, integer_zero_node));
2741 return build1 (TRUTH_NOT_EXPR, type, arg);
2743 case CLEANUP_POINT_EXPR:
2744 return build1 (CLEANUP_POINT_EXPR, type,
2745 invert_truthvalue (TREE_OPERAND (arg, 0)));
2750 if (TREE_CODE (TREE_TYPE (arg)) != BOOLEAN_TYPE)
2752 return build1 (TRUTH_NOT_EXPR, type, arg);
2755 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
2756 operands are another bit-wise operation with a common input. If so,
2757 distribute the bit operations to save an operation and possibly two if
2758 constants are involved. For example, convert
2759 (A | B) & (A | C) into A | (B & C)
2760 Further simplification will occur if B and C are constants.
2762 If this optimization cannot be done, 0 will be returned. */
2765 distribute_bit_expr (enum tree_code code, tree type, tree arg0, tree arg1)
2770 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2771 || TREE_CODE (arg0) == code
2772 || (TREE_CODE (arg0) != BIT_AND_EXPR
2773 && TREE_CODE (arg0) != BIT_IOR_EXPR))
2776 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
2778 common = TREE_OPERAND (arg0, 0);
2779 left = TREE_OPERAND (arg0, 1);
2780 right = TREE_OPERAND (arg1, 1);
2782 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
2784 common = TREE_OPERAND (arg0, 0);
2785 left = TREE_OPERAND (arg0, 1);
2786 right = TREE_OPERAND (arg1, 0);
2788 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
2790 common = TREE_OPERAND (arg0, 1);
2791 left = TREE_OPERAND (arg0, 0);
2792 right = TREE_OPERAND (arg1, 1);
2794 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
2796 common = TREE_OPERAND (arg0, 1);
2797 left = TREE_OPERAND (arg0, 0);
2798 right = TREE_OPERAND (arg1, 0);
2803 return fold (build (TREE_CODE (arg0), type, common,
2804 fold (build (code, type, left, right))));
2807 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
2808 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
2811 make_bit_field_ref (tree inner, tree type, int bitsize, int bitpos,
2814 tree result = build (BIT_FIELD_REF, type, inner,
2815 size_int (bitsize), bitsize_int (bitpos));
2817 BIT_FIELD_REF_UNSIGNED (result) = unsignedp;
2822 /* Optimize a bit-field compare.
2824 There are two cases: First is a compare against a constant and the
2825 second is a comparison of two items where the fields are at the same
2826 bit position relative to the start of a chunk (byte, halfword, word)
2827 large enough to contain it. In these cases we can avoid the shift
2828 implicit in bitfield extractions.
2830 For constants, we emit a compare of the shifted constant with the
2831 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
2832 compared. For two fields at the same position, we do the ANDs with the
2833 similar mask and compare the result of the ANDs.
2835 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
2836 COMPARE_TYPE is the type of the comparison, and LHS and RHS
2837 are the left and right operands of the comparison, respectively.
2839 If the optimization described above can be done, we return the resulting
2840 tree. Otherwise we return zero. */
2843 optimize_bit_field_compare (enum tree_code code, tree compare_type,
2846 HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
2847 tree type = TREE_TYPE (lhs);
2848 tree signed_type, unsigned_type;
2849 int const_p = TREE_CODE (rhs) == INTEGER_CST;
2850 enum machine_mode lmode, rmode, nmode;
2851 int lunsignedp, runsignedp;
2852 int lvolatilep = 0, rvolatilep = 0;
2853 tree linner, rinner = NULL_TREE;
2857 /* Get all the information about the extractions being done. If the bit size
2858 if the same as the size of the underlying object, we aren't doing an
2859 extraction at all and so can do nothing. We also don't want to
2860 do anything if the inner expression is a PLACEHOLDER_EXPR since we
2861 then will no longer be able to replace it. */
2862 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
2863 &lunsignedp, &lvolatilep);
2864 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
2865 || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
2870 /* If this is not a constant, we can only do something if bit positions,
2871 sizes, and signedness are the same. */
2872 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
2873 &runsignedp, &rvolatilep);
2875 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
2876 || lunsignedp != runsignedp || offset != 0
2877 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
2881 /* See if we can find a mode to refer to this field. We should be able to,
2882 but fail if we can't. */
2883 nmode = get_best_mode (lbitsize, lbitpos,
2884 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
2885 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
2886 TYPE_ALIGN (TREE_TYPE (rinner))),
2887 word_mode, lvolatilep || rvolatilep);
2888 if (nmode == VOIDmode)
2891 /* Set signed and unsigned types of the precision of this mode for the
2893 signed_type = lang_hooks.types.type_for_mode (nmode, 0);
2894 unsigned_type = lang_hooks.types.type_for_mode (nmode, 1);
2896 /* Compute the bit position and size for the new reference and our offset
2897 within it. If the new reference is the same size as the original, we
2898 won't optimize anything, so return zero. */
2899 nbitsize = GET_MODE_BITSIZE (nmode);
2900 nbitpos = lbitpos & ~ (nbitsize - 1);
2902 if (nbitsize == lbitsize)
2905 if (BYTES_BIG_ENDIAN)
2906 lbitpos = nbitsize - lbitsize - lbitpos;
2908 /* Make the mask to be used against the extracted field. */
2909 mask = build_int_2 (~0, ~0);
2910 TREE_TYPE (mask) = unsigned_type;
2911 force_fit_type (mask, 0);
2912 mask = fold_convert (unsigned_type, mask);
2913 mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
2914 mask = const_binop (RSHIFT_EXPR, mask,
2915 size_int (nbitsize - lbitsize - lbitpos), 0);
2918 /* If not comparing with constant, just rework the comparison
2920 return build (code, compare_type,
2921 build (BIT_AND_EXPR, unsigned_type,
2922 make_bit_field_ref (linner, unsigned_type,
2923 nbitsize, nbitpos, 1),
2925 build (BIT_AND_EXPR, unsigned_type,
2926 make_bit_field_ref (rinner, unsigned_type,
2927 nbitsize, nbitpos, 1),
2930 /* Otherwise, we are handling the constant case. See if the constant is too
2931 big for the field. Warn and return a tree of for 0 (false) if so. We do
2932 this not only for its own sake, but to avoid having to test for this
2933 error case below. If we didn't, we might generate wrong code.
2935 For unsigned fields, the constant shifted right by the field length should
2936 be all zero. For signed fields, the high-order bits should agree with
2941 if (! integer_zerop (const_binop (RSHIFT_EXPR,
2942 fold_convert (unsigned_type, rhs),
2943 size_int (lbitsize), 0)))
2945 warning ("comparison is always %d due to width of bit-field",
2947 return fold_convert (compare_type,
2949 ? integer_one_node : integer_zero_node));
2954 tree tem = const_binop (RSHIFT_EXPR, fold_convert (signed_type, rhs),
2955 size_int (lbitsize - 1), 0);
2956 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
2958 warning ("comparison is always %d due to width of bit-field",
2960 return fold_convert (compare_type,
2962 ? integer_one_node : integer_zero_node));
2966 /* Single-bit compares should always be against zero. */
2967 if (lbitsize == 1 && ! integer_zerop (rhs))
2969 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
2970 rhs = fold_convert (type, integer_zero_node);
2973 /* Make a new bitfield reference, shift the constant over the
2974 appropriate number of bits and mask it with the computed mask
2975 (in case this was a signed field). If we changed it, make a new one. */
2976 lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1);
2979 TREE_SIDE_EFFECTS (lhs) = 1;
2980 TREE_THIS_VOLATILE (lhs) = 1;
2983 rhs = fold (const_binop (BIT_AND_EXPR,
2984 const_binop (LSHIFT_EXPR,
2985 fold_convert (unsigned_type, rhs),
2986 size_int (lbitpos), 0),
2989 return build (code, compare_type,
2990 build (BIT_AND_EXPR, unsigned_type, lhs, mask),
2994 /* Subroutine for fold_truthop: decode a field reference.
2996 If EXP is a comparison reference, we return the innermost reference.
2998 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
2999 set to the starting bit number.
3001 If the innermost field can be completely contained in a mode-sized
3002 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
3004 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
3005 otherwise it is not changed.
3007 *PUNSIGNEDP is set to the signedness of the field.
3009 *PMASK is set to the mask used. This is either contained in a
3010 BIT_AND_EXPR or derived from the width of the field.
3012 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
3014 Return 0 if this is not a component reference or is one that we can't
3015 do anything with. */
3018 decode_field_reference (tree exp, HOST_WIDE_INT *pbitsize,
3019 HOST_WIDE_INT *pbitpos, enum machine_mode *pmode,
3020 int *punsignedp, int *pvolatilep,
3021 tree *pmask, tree *pand_mask)
3023 tree outer_type = 0;
3025 tree mask, inner, offset;
3027 unsigned int precision;
3029 /* All the optimizations using this function assume integer fields.
3030 There are problems with FP fields since the type_for_size call
3031 below can fail for, e.g., XFmode. */
3032 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
3035 /* We are interested in the bare arrangement of bits, so strip everything
3036 that doesn't affect the machine mode. However, record the type of the
3037 outermost expression if it may matter below. */
3038 if (TREE_CODE (exp) == NOP_EXPR
3039 || TREE_CODE (exp) == CONVERT_EXPR
3040 || TREE_CODE (exp) == NON_LVALUE_EXPR)
3041 outer_type = TREE_TYPE (exp);
3044 if (TREE_CODE (exp) == BIT_AND_EXPR)
3046 and_mask = TREE_OPERAND (exp, 1);
3047 exp = TREE_OPERAND (exp, 0);
3048 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
3049 if (TREE_CODE (and_mask) != INTEGER_CST)
3053 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
3054 punsignedp, pvolatilep);
3055 if ((inner == exp && and_mask == 0)
3056 || *pbitsize < 0 || offset != 0
3057 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
3060 /* If the number of bits in the reference is the same as the bitsize of
3061 the outer type, then the outer type gives the signedness. Otherwise
3062 (in case of a small bitfield) the signedness is unchanged. */
3063 if (outer_type && *pbitsize == tree_low_cst (TYPE_SIZE (outer_type), 1))
3064 *punsignedp = TYPE_UNSIGNED (outer_type);
3066 /* Compute the mask to access the bitfield. */
3067 unsigned_type = lang_hooks.types.type_for_size (*pbitsize, 1);
3068 precision = TYPE_PRECISION (unsigned_type);
3070 mask = build_int_2 (~0, ~0);
3071 TREE_TYPE (mask) = unsigned_type;
3072 force_fit_type (mask, 0);
3073 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3074 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3076 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
3078 mask = fold (build (BIT_AND_EXPR, unsigned_type,
3079 fold_convert (unsigned_type, and_mask), mask));
3082 *pand_mask = and_mask;
3086 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
3090 all_ones_mask_p (tree mask, int size)
3092 tree type = TREE_TYPE (mask);
3093 unsigned int precision = TYPE_PRECISION (type);
3096 tmask = build_int_2 (~0, ~0);
3097 TREE_TYPE (tmask) = lang_hooks.types.signed_type (type);
3098 force_fit_type (tmask, 0);
3100 tree_int_cst_equal (mask,
3101 const_binop (RSHIFT_EXPR,
3102 const_binop (LSHIFT_EXPR, tmask,
3103 size_int (precision - size),
3105 size_int (precision - size), 0));
3108 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
3109 represents the sign bit of EXP's type. If EXP represents a sign
3110 or zero extension, also test VAL against the unextended type.
3111 The return value is the (sub)expression whose sign bit is VAL,
3112 or NULL_TREE otherwise. */
3115 sign_bit_p (tree exp, tree val)
3117 unsigned HOST_WIDE_INT mask_lo, lo;
3118 HOST_WIDE_INT mask_hi, hi;
3122 /* Tree EXP must have an integral type. */
3123 t = TREE_TYPE (exp);
3124 if (! INTEGRAL_TYPE_P (t))
3127 /* Tree VAL must be an integer constant. */
3128 if (TREE_CODE (val) != INTEGER_CST
3129 || TREE_CONSTANT_OVERFLOW (val))
3132 width = TYPE_PRECISION (t);
3133 if (width > HOST_BITS_PER_WIDE_INT)
3135 hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1);
3138 mask_hi = ((unsigned HOST_WIDE_INT) -1
3139 >> (2 * HOST_BITS_PER_WIDE_INT - width));
3145 lo = (unsigned HOST_WIDE_INT) 1 << (width - 1);
3148 mask_lo = ((unsigned HOST_WIDE_INT) -1
3149 >> (HOST_BITS_PER_WIDE_INT - width));
3152 /* We mask off those bits beyond TREE_TYPE (exp) so that we can
3153 treat VAL as if it were unsigned. */
3154 if ((TREE_INT_CST_HIGH (val) & mask_hi) == hi
3155 && (TREE_INT_CST_LOW (val) & mask_lo) == lo)
3158 /* Handle extension from a narrower type. */
3159 if (TREE_CODE (exp) == NOP_EXPR
3160 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width)
3161 return sign_bit_p (TREE_OPERAND (exp, 0), val);
3166 /* Subroutine for fold_truthop: determine if an operand is simple enough
3167 to be evaluated unconditionally. */
3170 simple_operand_p (tree exp)
3172 /* Strip any conversions that don't change the machine mode. */
3173 while ((TREE_CODE (exp) == NOP_EXPR
3174 || TREE_CODE (exp) == CONVERT_EXPR)
3175 && (TYPE_MODE (TREE_TYPE (exp))
3176 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)))))
3177 exp = TREE_OPERAND (exp, 0);
3179 return (TREE_CODE_CLASS (TREE_CODE (exp)) == 'c'
3181 && ! TREE_ADDRESSABLE (exp)
3182 && ! TREE_THIS_VOLATILE (exp)
3183 && ! DECL_NONLOCAL (exp)
3184 /* Don't regard global variables as simple. They may be
3185 allocated in ways unknown to the compiler (shared memory,
3186 #pragma weak, etc). */
3187 && ! TREE_PUBLIC (exp)
3188 && ! DECL_EXTERNAL (exp)
3189 /* Loading a static variable is unduly expensive, but global
3190 registers aren't expensive. */
3191 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
3194 /* The following functions are subroutines to fold_range_test and allow it to
3195 try to change a logical combination of comparisons into a range test.
3198 X == 2 || X == 3 || X == 4 || X == 5
3202 (unsigned) (X - 2) <= 3
3204 We describe each set of comparisons as being either inside or outside
3205 a range, using a variable named like IN_P, and then describe the
3206 range with a lower and upper bound. If one of the bounds is omitted,
3207 it represents either the highest or lowest value of the type.
3209 In the comments below, we represent a range by two numbers in brackets
3210 preceded by a "+" to designate being inside that range, or a "-" to
3211 designate being outside that range, so the condition can be inverted by
3212 flipping the prefix. An omitted bound is represented by a "-". For
3213 example, "- [-, 10]" means being outside the range starting at the lowest
3214 possible value and ending at 10, in other words, being greater than 10.
3215 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
3218 We set up things so that the missing bounds are handled in a consistent
3219 manner so neither a missing bound nor "true" and "false" need to be
3220 handled using a special case. */
3222 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
3223 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
3224 and UPPER1_P are nonzero if the respective argument is an upper bound
3225 and zero for a lower. TYPE, if nonzero, is the type of the result; it
3226 must be specified for a comparison. ARG1 will be converted to ARG0's
3227 type if both are specified. */
3230 range_binop (enum tree_code code, tree type, tree arg0, int upper0_p,
3231 tree arg1, int upper1_p)
3237 /* If neither arg represents infinity, do the normal operation.
3238 Else, if not a comparison, return infinity. Else handle the special
3239 comparison rules. Note that most of the cases below won't occur, but
3240 are handled for consistency. */
3242 if (arg0 != 0 && arg1 != 0)
3244 tem = fold (build (code, type != 0 ? type : TREE_TYPE (arg0),
3245 arg0, fold_convert (TREE_TYPE (arg0), arg1)));
3247 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
3250 if (TREE_CODE_CLASS (code) != '<')
3253 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
3254 for neither. In real maths, we cannot assume open ended ranges are
3255 the same. But, this is computer arithmetic, where numbers are finite.
3256 We can therefore make the transformation of any unbounded range with
3257 the value Z, Z being greater than any representable number. This permits
3258 us to treat unbounded ranges as equal. */
3259 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
3260 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
3264 result = sgn0 == sgn1;
3267 result = sgn0 != sgn1;
3270 result = sgn0 < sgn1;
3273 result = sgn0 <= sgn1;
3276 result = sgn0 > sgn1;
3279 result = sgn0 >= sgn1;
3285 return fold_convert (type, result ? integer_one_node : integer_zero_node);
3288 /* Given EXP, a logical expression, set the range it is testing into
3289 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
3290 actually being tested. *PLOW and *PHIGH will be made of the same type
3291 as the returned expression. If EXP is not a comparison, we will most
3292 likely not be returning a useful value and range. */
3295 make_range (tree exp, int *pin_p, tree *plow, tree *phigh)
3297 enum tree_code code;
3298 tree arg0 = NULL_TREE, arg1 = NULL_TREE, type = NULL_TREE;
3299 tree orig_type = NULL_TREE;
3301 tree low, high, n_low, n_high;
3303 /* Start with simply saying "EXP != 0" and then look at the code of EXP
3304 and see if we can refine the range. Some of the cases below may not
3305 happen, but it doesn't seem worth worrying about this. We "continue"
3306 the outer loop when we've changed something; otherwise we "break"
3307 the switch, which will "break" the while. */
3310 low = high = fold_convert (TREE_TYPE (exp), integer_zero_node);
3314 code = TREE_CODE (exp);
3316 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
3318 if (first_rtl_op (code) > 0)
3319 arg0 = TREE_OPERAND (exp, 0);
3320 if (TREE_CODE_CLASS (code) == '<'
3321 || TREE_CODE_CLASS (code) == '1'
3322 || TREE_CODE_CLASS (code) == '2')
3323 type = TREE_TYPE (arg0);
3324 if (TREE_CODE_CLASS (code) == '2'
3325 || TREE_CODE_CLASS (code) == '<'
3326 || (TREE_CODE_CLASS (code) == 'e'
3327 && TREE_CODE_LENGTH (code) > 1))
3328 arg1 = TREE_OPERAND (exp, 1);
3331 /* Set ORIG_TYPE as soon as TYPE is non-null so that we do not
3332 lose a cast by accident. */
3333 if (type != NULL_TREE && orig_type == NULL_TREE)
3338 case TRUTH_NOT_EXPR:
3339 in_p = ! in_p, exp = arg0;
3342 case EQ_EXPR: case NE_EXPR:
3343 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
3344 /* We can only do something if the range is testing for zero
3345 and if the second operand is an integer constant. Note that
3346 saying something is "in" the range we make is done by
3347 complementing IN_P since it will set in the initial case of
3348 being not equal to zero; "out" is leaving it alone. */
3349 if (low == 0 || high == 0
3350 || ! integer_zerop (low) || ! integer_zerop (high)
3351 || TREE_CODE (arg1) != INTEGER_CST)
3356 case NE_EXPR: /* - [c, c] */
3359 case EQ_EXPR: /* + [c, c] */
3360 in_p = ! in_p, low = high = arg1;
3362 case GT_EXPR: /* - [-, c] */
3363 low = 0, high = arg1;
3365 case GE_EXPR: /* + [c, -] */
3366 in_p = ! in_p, low = arg1, high = 0;
3368 case LT_EXPR: /* - [c, -] */
3369 low = arg1, high = 0;
3371 case LE_EXPR: /* + [-, c] */
3372 in_p = ! in_p, low = 0, high = arg1;
3380 /* If this is an unsigned comparison, we also know that EXP is
3381 greater than or equal to zero. We base the range tests we make
3382 on that fact, so we record it here so we can parse existing
3384 if (TYPE_UNSIGNED (type) && (low == 0 || high == 0))
3386 if (! merge_ranges (&n_in_p, &n_low, &n_high, in_p, low, high,
3387 1, fold_convert (type, integer_zero_node),
3391 in_p = n_in_p, low = n_low, high = n_high;
3393 /* If the high bound is missing, but we have a nonzero low
3394 bound, reverse the range so it goes from zero to the low bound
3396 if (high == 0 && low && ! integer_zerop (low))
3399 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
3400 integer_one_node, 0);
3401 low = fold_convert (type, integer_zero_node);
3407 /* (-x) IN [a,b] -> x in [-b, -a] */
3408 n_low = range_binop (MINUS_EXPR, type,
3409 fold_convert (type, integer_zero_node),
3411 n_high = range_binop (MINUS_EXPR, type,
3412 fold_convert (type, integer_zero_node),
3414 low = n_low, high = n_high;
3420 exp = build (MINUS_EXPR, type, negate_expr (arg0),
3421 fold_convert (type, integer_one_node));
3424 case PLUS_EXPR: case MINUS_EXPR:
3425 if (TREE_CODE (arg1) != INTEGER_CST)
3428 /* If EXP is signed, any overflow in the computation is undefined,
3429 so we don't worry about it so long as our computations on
3430 the bounds don't overflow. For unsigned, overflow is defined
3431 and this is exactly the right thing. */
3432 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3433 type, low, 0, arg1, 0);
3434 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3435 type, high, 1, arg1, 0);
3436 if ((n_low != 0 && TREE_OVERFLOW (n_low))
3437 || (n_high != 0 && TREE_OVERFLOW (n_high)))
3440 /* Check for an unsigned range which has wrapped around the maximum
3441 value thus making n_high < n_low, and normalize it. */
3442 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
3444 low = range_binop (PLUS_EXPR, type, n_high, 0,
3445 integer_one_node, 0);
3446 high = range_binop (MINUS_EXPR, type, n_low, 0,
3447 integer_one_node, 0);
3449 /* If the range is of the form +/- [ x+1, x ], we won't
3450 be able to normalize it. But then, it represents the
3451 whole range or the empty set, so make it
3453 if (tree_int_cst_equal (n_low, low)
3454 && tree_int_cst_equal (n_high, high))
3460 low = n_low, high = n_high;
3465 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
3466 if (TYPE_PRECISION (type) > TYPE_PRECISION (orig_type))
3469 if (! INTEGRAL_TYPE_P (type)
3470 || (low != 0 && ! int_fits_type_p (low, type))
3471 || (high != 0 && ! int_fits_type_p (high, type)))
3474 n_low = low, n_high = high;
3477 n_low = fold_convert (type, n_low);
3480 n_high = fold_convert (type, n_high);
3482 /* If we're converting from an unsigned to a signed type,
3483 we will be doing the comparison as unsigned. The tests above
3484 have already verified that LOW and HIGH are both positive.
3486 So we have to make sure that the original unsigned value will
3487 be interpreted as positive. */
3488 if (TYPE_UNSIGNED (type) && ! TYPE_UNSIGNED (TREE_TYPE (exp)))
3490 tree equiv_type = lang_hooks.types.type_for_mode
3491 (TYPE_MODE (type), 1);
3494 /* A range without an upper bound is, naturally, unbounded.
3495 Since convert would have cropped a very large value, use
3496 the max value for the destination type. */
3498 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
3499 : TYPE_MAX_VALUE (type);
3501 if (TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (exp)))
3502 high_positive = fold (build (RSHIFT_EXPR, type,
3506 integer_one_node)));
3508 /* If the low bound is specified, "and" the range with the
3509 range for which the original unsigned value will be
3513 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3514 1, n_low, n_high, 1,
3515 fold_convert (type, integer_zero_node),
3519 in_p = (n_in_p == in_p);
3523 /* Otherwise, "or" the range with the range of the input
3524 that will be interpreted as negative. */
3525 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3526 0, n_low, n_high, 1,
3527 fold_convert (type, integer_zero_node),
3531 in_p = (in_p != n_in_p);
3536 low = n_low, high = n_high;
3546 /* If EXP is a constant, we can evaluate whether this is true or false. */
3547 if (TREE_CODE (exp) == INTEGER_CST)
3549 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
3551 && integer_onep (range_binop (LE_EXPR, integer_type_node,
3557 *pin_p = in_p, *plow = low, *phigh = high;
3561 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3562 type, TYPE, return an expression to test if EXP is in (or out of, depending
3563 on IN_P) the range. */
3566 build_range_check (tree type, tree exp, int in_p, tree low, tree high)
3568 tree etype = TREE_TYPE (exp);
3572 && (0 != (value = build_range_check (type, exp, 1, low, high))))
3573 return invert_truthvalue (value);
3575 if (low == 0 && high == 0)
3576 return fold_convert (type, integer_one_node);
3579 return fold (build (LE_EXPR, type, exp, high));
3582 return fold (build (GE_EXPR, type, exp, low));
3584 if (operand_equal_p (low, high, 0))
3585 return fold (build (EQ_EXPR, type, exp, low));
3587 if (integer_zerop (low))
3589 if (! TYPE_UNSIGNED (etype))
3591 etype = lang_hooks.types.unsigned_type (etype);
3592 high = fold_convert (etype, high);
3593 exp = fold_convert (etype, exp);
3595 return build_range_check (type, exp, 1, 0, high);
3598 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
3599 if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST)
3601 unsigned HOST_WIDE_INT lo;
3605 prec = TYPE_PRECISION (etype);
3606 if (prec <= HOST_BITS_PER_WIDE_INT)
3609 lo = ((unsigned HOST_WIDE_INT) 1 << (prec - 1)) - 1;
3613 hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1;
3614 lo = (unsigned HOST_WIDE_INT) -1;
3617 if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo)
3619 if (TYPE_UNSIGNED (etype))
3621 etype = lang_hooks.types.signed_type (etype);
3622 exp = fold_convert (etype, exp);
3624 return fold (build (GT_EXPR, type, exp,
3625 fold_convert (etype, integer_zero_node)));
3629 if (0 != (value = const_binop (MINUS_EXPR, high, low, 0))
3630 && ! TREE_OVERFLOW (value))
3631 return build_range_check (type,
3632 fold (build (MINUS_EXPR, etype, exp, low)),
3633 1, fold_convert (etype, integer_zero_node),
3639 /* Given two ranges, see if we can merge them into one. Return 1 if we
3640 can, 0 if we can't. Set the output range into the specified parameters. */
3643 merge_ranges (int *pin_p, tree *plow, tree *phigh, int in0_p, tree low0,
3644 tree high0, int in1_p, tree low1, tree high1)
3652 int lowequal = ((low0 == 0 && low1 == 0)
3653 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3654 low0, 0, low1, 0)));
3655 int highequal = ((high0 == 0 && high1 == 0)
3656 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3657 high0, 1, high1, 1)));
3659 /* Make range 0 be the range that starts first, or ends last if they
3660 start at the same value. Swap them if it isn't. */
3661 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
3664 && integer_onep (range_binop (GT_EXPR, integer_type_node,
3665 high1, 1, high0, 1))))
3667 temp = in0_p, in0_p = in1_p, in1_p = temp;
3668 tem = low0, low0 = low1, low1 = tem;
3669 tem = high0, high0 = high1, high1 = tem;
3672 /* Now flag two cases, whether the ranges are disjoint or whether the
3673 second range is totally subsumed in the first. Note that the tests
3674 below are simplified by the ones above. */
3675 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
3676 high0, 1, low1, 0));
3677 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
3678 high1, 1, high0, 1));
3680 /* We now have four cases, depending on whether we are including or
3681 excluding the two ranges. */
3684 /* If they don't overlap, the result is false. If the second range
3685 is a subset it is the result. Otherwise, the range is from the start
3686 of the second to the end of the first. */
3688 in_p = 0, low = high = 0;
3690 in_p = 1, low = low1, high = high1;
3692 in_p = 1, low = low1, high = high0;
3695 else if (in0_p && ! in1_p)
3697 /* If they don't overlap, the result is the first range. If they are
3698 equal, the result is false. If the second range is a subset of the
3699 first, and the ranges begin at the same place, we go from just after
3700 the end of the first range to the end of the second. If the second
3701 range is not a subset of the first, or if it is a subset and both
3702 ranges end at the same place, the range starts at the start of the
3703 first range and ends just before the second range.
3704 Otherwise, we can't describe this as a single range. */
3706 in_p = 1, low = low0, high = high0;
3707 else if (lowequal && highequal)
3708 in_p = 0, low = high = 0;
3709 else if (subset && lowequal)
3711 in_p = 1, high = high0;
3712 low = range_binop (PLUS_EXPR, NULL_TREE, high1, 0,
3713 integer_one_node, 0);
3715 else if (! subset || highequal)
3717 in_p = 1, low = low0;
3718 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
3719 integer_one_node, 0);
3725 else if (! in0_p && in1_p)
3727 /* If they don't overlap, the result is the second range. If the second
3728 is a subset of the first, the result is false. Otherwise,
3729 the range starts just after the first range and ends at the
3730 end of the second. */
3732 in_p = 1, low = low1, high = high1;
3733 else if (subset || highequal)
3734 in_p = 0, low = high = 0;
3737 in_p = 1, high = high1;
3738 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
3739 integer_one_node, 0);
3745 /* The case where we are excluding both ranges. Here the complex case
3746 is if they don't overlap. In that case, the only time we have a
3747 range is if they are adjacent. If the second is a subset of the
3748 first, the result is the first. Otherwise, the range to exclude
3749 starts at the beginning of the first range and ends at the end of the
3753 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
3754 range_binop (PLUS_EXPR, NULL_TREE,
3756 integer_one_node, 1),
3758 in_p = 0, low = low0, high = high1;
3763 in_p = 0, low = low0, high = high0;
3765 in_p = 0, low = low0, high = high1;
3768 *pin_p = in_p, *plow = low, *phigh = high;
3772 #ifndef RANGE_TEST_NON_SHORT_CIRCUIT
3773 #define RANGE_TEST_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
3776 /* EXP is some logical combination of boolean tests. See if we can
3777 merge it into some range test. Return the new tree if so. */
3780 fold_range_test (tree exp)
3782 int or_op = (TREE_CODE (exp) == TRUTH_ORIF_EXPR
3783 || TREE_CODE (exp) == TRUTH_OR_EXPR);
3784 int in0_p, in1_p, in_p;
3785 tree low0, low1, low, high0, high1, high;
3786 tree lhs = make_range (TREE_OPERAND (exp, 0), &in0_p, &low0, &high0);
3787 tree rhs = make_range (TREE_OPERAND (exp, 1), &in1_p, &low1, &high1);
3790 /* If this is an OR operation, invert both sides; we will invert
3791 again at the end. */
3793 in0_p = ! in0_p, in1_p = ! in1_p;
3795 /* If both expressions are the same, if we can merge the ranges, and we
3796 can build the range test, return it or it inverted. If one of the
3797 ranges is always true or always false, consider it to be the same
3798 expression as the other. */
3799 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
3800 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
3802 && 0 != (tem = (build_range_check (TREE_TYPE (exp),
3804 : rhs != 0 ? rhs : integer_zero_node,
3806 return or_op ? invert_truthvalue (tem) : tem;
3808 /* On machines where the branch cost is expensive, if this is a
3809 short-circuited branch and the underlying object on both sides
3810 is the same, make a non-short-circuit operation. */
3811 else if (RANGE_TEST_NON_SHORT_CIRCUIT
3812 && lhs != 0 && rhs != 0
3813 && (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3814 || TREE_CODE (exp) == TRUTH_ORIF_EXPR)
3815 && operand_equal_p (lhs, rhs, 0))
3817 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
3818 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
3819 which cases we can't do this. */
3820 if (simple_operand_p (lhs))
3821 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3822 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3823 TREE_TYPE (exp), TREE_OPERAND (exp, 0),
3824 TREE_OPERAND (exp, 1));
3826 else if (lang_hooks.decls.global_bindings_p () == 0
3827 && ! CONTAINS_PLACEHOLDER_P (lhs))
3829 tree common = save_expr (lhs);
3831 if (0 != (lhs = build_range_check (TREE_TYPE (exp), common,
3832 or_op ? ! in0_p : in0_p,
3834 && (0 != (rhs = build_range_check (TREE_TYPE (exp), common,
3835 or_op ? ! in1_p : in1_p,
3837 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3838 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3839 TREE_TYPE (exp), lhs, rhs);
3846 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
3847 bit value. Arrange things so the extra bits will be set to zero if and
3848 only if C is signed-extended to its full width. If MASK is nonzero,
3849 it is an INTEGER_CST that should be AND'ed with the extra bits. */
3852 unextend (tree c, int p, int unsignedp, tree mask)
3854 tree type = TREE_TYPE (c);
3855 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
3858 if (p == modesize || unsignedp)
3861 /* We work by getting just the sign bit into the low-order bit, then
3862 into the high-order bit, then sign-extend. We then XOR that value
3864 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
3865 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
3867 /* We must use a signed type in order to get an arithmetic right shift.
3868 However, we must also avoid introducing accidental overflows, so that
3869 a subsequent call to integer_zerop will work. Hence we must
3870 do the type conversion here. At this point, the constant is either
3871 zero or one, and the conversion to a signed type can never overflow.
3872 We could get an overflow if this conversion is done anywhere else. */
3873 if (TYPE_UNSIGNED (type))
3874 temp = fold_convert (lang_hooks.types.signed_type (type), temp);
3876 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
3877 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
3879 temp = const_binop (BIT_AND_EXPR, temp,
3880 fold_convert (TREE_TYPE (c), mask), 0);
3881 /* If necessary, convert the type back to match the type of C. */
3882 if (TYPE_UNSIGNED (type))
3883 temp = fold_convert (type, temp);
3885 return fold_convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
3888 /* Find ways of folding logical expressions of LHS and RHS:
3889 Try to merge two comparisons to the same innermost item.
3890 Look for range tests like "ch >= '0' && ch <= '9'".
3891 Look for combinations of simple terms on machines with expensive branches
3892 and evaluate the RHS unconditionally.
3894 For example, if we have p->a == 2 && p->b == 4 and we can make an
3895 object large enough to span both A and B, we can do this with a comparison
3896 against the object ANDed with the a mask.
3898 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
3899 operations to do this with one comparison.
3901 We check for both normal comparisons and the BIT_AND_EXPRs made this by
3902 function and the one above.
3904 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
3905 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
3907 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
3910 We return the simplified tree or 0 if no optimization is possible. */
3913 fold_truthop (enum tree_code code, tree truth_type, tree lhs, tree rhs)
3915 /* If this is the "or" of two comparisons, we can do something if
3916 the comparisons are NE_EXPR. If this is the "and", we can do something
3917 if the comparisons are EQ_EXPR. I.e.,
3918 (a->b == 2 && a->c == 4) can become (a->new == NEW).
3920 WANTED_CODE is this operation code. For single bit fields, we can
3921 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
3922 comparison for one-bit fields. */
3924 enum tree_code wanted_code;
3925 enum tree_code lcode, rcode;
3926 tree ll_arg, lr_arg, rl_arg, rr_arg;
3927 tree ll_inner, lr_inner, rl_inner, rr_inner;
3928 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
3929 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
3930 HOST_WIDE_INT xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
3931 HOST_WIDE_INT lnbitsize, lnbitpos, rnbitsize, rnbitpos;
3932 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
3933 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
3934 enum machine_mode lnmode, rnmode;
3935 tree ll_mask, lr_mask, rl_mask, rr_mask;
3936 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
3937 tree l_const, r_const;
3938 tree lntype, rntype, result;
3939 int first_bit, end_bit;
3942 /* Start by getting the comparison codes. Fail if anything is volatile.
3943 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
3944 it were surrounded with a NE_EXPR. */
3946 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
3949 lcode = TREE_CODE (lhs);
3950 rcode = TREE_CODE (rhs);
3952 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
3953 lcode = NE_EXPR, lhs = build (NE_EXPR, truth_type, lhs, integer_zero_node);
3955 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
3956 rcode = NE_EXPR, rhs = build (NE_EXPR, truth_type, rhs, integer_zero_node);
3958 if (TREE_CODE_CLASS (lcode) != '<' || TREE_CODE_CLASS (rcode) != '<')
3961 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
3962 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
3964 ll_arg = TREE_OPERAND (lhs, 0);
3965 lr_arg = TREE_OPERAND (lhs, 1);
3966 rl_arg = TREE_OPERAND (rhs, 0);
3967 rr_arg = TREE_OPERAND (rhs, 1);
3969 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
3970 if (simple_operand_p (ll_arg)
3971 && simple_operand_p (lr_arg)
3972 && !FLOAT_TYPE_P (TREE_TYPE (ll_arg)))
3976 if (operand_equal_p (ll_arg, rl_arg, 0)
3977 && operand_equal_p (lr_arg, rr_arg, 0))
3979 int lcompcode, rcompcode;
3981 lcompcode = comparison_to_compcode (lcode);
3982 rcompcode = comparison_to_compcode (rcode);
3983 compcode = (code == TRUTH_AND_EXPR)
3984 ? lcompcode & rcompcode
3985 : lcompcode | rcompcode;
3987 else if (operand_equal_p (ll_arg, rr_arg, 0)
3988 && operand_equal_p (lr_arg, rl_arg, 0))
3990 int lcompcode, rcompcode;
3992 rcode = swap_tree_comparison (rcode);
3993 lcompcode = comparison_to_compcode (lcode);
3994 rcompcode = comparison_to_compcode (rcode);
3995 compcode = (code == TRUTH_AND_EXPR)
3996 ? lcompcode & rcompcode
3997 : lcompcode | rcompcode;
4002 if (compcode == COMPCODE_TRUE)
4003 return fold_convert (truth_type, integer_one_node);
4004 else if (compcode == COMPCODE_FALSE)
4005 return fold_convert (truth_type, integer_zero_node);
4006 else if (compcode != -1)
4007 return build (compcode_to_comparison (compcode),
4008 truth_type, ll_arg, lr_arg);
4011 /* If the RHS can be evaluated unconditionally and its operands are
4012 simple, it wins to evaluate the RHS unconditionally on machines
4013 with expensive branches. In this case, this isn't a comparison
4014 that can be merged. Avoid doing this if the RHS is a floating-point
4015 comparison since those can trap. */
4017 if (BRANCH_COST >= 2
4018 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
4019 && simple_operand_p (rl_arg)
4020 && simple_operand_p (rr_arg))
4022 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
4023 if (code == TRUTH_OR_EXPR
4024 && lcode == NE_EXPR && integer_zerop (lr_arg)
4025 && rcode == NE_EXPR && integer_zerop (rr_arg)
4026 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
4027 return build (NE_EXPR, truth_type,
4028 build (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
4032 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
4033 if (code == TRUTH_AND_EXPR
4034 && lcode == EQ_EXPR && integer_zerop (lr_arg)
4035 && rcode == EQ_EXPR && integer_zerop (rr_arg)
4036 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
4037 return build (EQ_EXPR, truth_type,
4038 build (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
4042 return build (code, truth_type, lhs, rhs);
4045 /* See if the comparisons can be merged. Then get all the parameters for
4048 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
4049 || (rcode != EQ_EXPR && rcode != NE_EXPR))
4053 ll_inner = decode_field_reference (ll_arg,
4054 &ll_bitsize, &ll_bitpos, &ll_mode,
4055 &ll_unsignedp, &volatilep, &ll_mask,
4057 lr_inner = decode_field_reference (lr_arg,
4058 &lr_bitsize, &lr_bitpos, &lr_mode,
4059 &lr_unsignedp, &volatilep, &lr_mask,
4061 rl_inner = decode_field_reference (rl_arg,
4062 &rl_bitsize, &rl_bitpos, &rl_mode,
4063 &rl_unsignedp, &volatilep, &rl_mask,
4065 rr_inner = decode_field_reference (rr_arg,
4066 &rr_bitsize, &rr_bitpos, &rr_mode,
4067 &rr_unsignedp, &volatilep, &rr_mask,
4070 /* It must be true that the inner operation on the lhs of each
4071 comparison must be the same if we are to be able to do anything.
4072 Then see if we have constants. If not, the same must be true for
4074 if (volatilep || ll_inner == 0 || rl_inner == 0
4075 || ! operand_equal_p (ll_inner, rl_inner, 0))
4078 if (TREE_CODE (lr_arg) == INTEGER_CST
4079 && TREE_CODE (rr_arg) == INTEGER_CST)
4080 l_const = lr_arg, r_const = rr_arg;
4081 else if (lr_inner == 0 || rr_inner == 0
4082 || ! operand_equal_p (lr_inner, rr_inner, 0))
4085 l_const = r_const = 0;
4087 /* If either comparison code is not correct for our logical operation,
4088 fail. However, we can convert a one-bit comparison against zero into
4089 the opposite comparison against that bit being set in the field. */
4091 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
4092 if (lcode != wanted_code)
4094 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
4096 /* Make the left operand unsigned, since we are only interested
4097 in the value of one bit. Otherwise we are doing the wrong
4106 /* This is analogous to the code for l_const above. */
4107 if (rcode != wanted_code)
4109 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
4118 /* After this point all optimizations will generate bit-field
4119 references, which we might not want. */
4120 if (! lang_hooks.can_use_bit_fields_p ())
4123 /* See if we can find a mode that contains both fields being compared on
4124 the left. If we can't, fail. Otherwise, update all constants and masks
4125 to be relative to a field of that size. */
4126 first_bit = MIN (ll_bitpos, rl_bitpos);
4127 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
4128 lnmode = get_best_mode (end_bit - first_bit, first_bit,
4129 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
4131 if (lnmode == VOIDmode)
4134 lnbitsize = GET_MODE_BITSIZE (lnmode);
4135 lnbitpos = first_bit & ~ (lnbitsize - 1);
4136 lntype = lang_hooks.types.type_for_size (lnbitsize, 1);
4137 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
4139 if (BYTES_BIG_ENDIAN)
4141 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
4142 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
4145 ll_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, ll_mask),
4146 size_int (xll_bitpos), 0);
4147 rl_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, rl_mask),
4148 size_int (xrl_bitpos), 0);
4152 l_const = fold_convert (lntype, l_const);
4153 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
4154 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
4155 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
4156 fold (build1 (BIT_NOT_EXPR,
4160 warning ("comparison is always %d", wanted_code == NE_EXPR);
4162 return fold_convert (truth_type,
4163 wanted_code == NE_EXPR
4164 ? integer_one_node : integer_zero_node);
4169 r_const = fold_convert (lntype, r_const);
4170 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
4171 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
4172 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
4173 fold (build1 (BIT_NOT_EXPR,
4177 warning ("comparison is always %d", wanted_code == NE_EXPR);
4179 return fold_convert (truth_type,
4180 wanted_code == NE_EXPR
4181 ? integer_one_node : integer_zero_node);
4185 /* If the right sides are not constant, do the same for it. Also,
4186 disallow this optimization if a size or signedness mismatch occurs
4187 between the left and right sides. */
4190 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
4191 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
4192 /* Make sure the two fields on the right
4193 correspond to the left without being swapped. */
4194 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
4197 first_bit = MIN (lr_bitpos, rr_bitpos);
4198 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
4199 rnmode = get_best_mode (end_bit - first_bit, first_bit,
4200 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
4202 if (rnmode == VOIDmode)
4205 rnbitsize = GET_MODE_BITSIZE (rnmode);
4206 rnbitpos = first_bit & ~ (rnbitsize - 1);
4207 rntype = lang_hooks.types.type_for_size (rnbitsize, 1);
4208 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
4210 if (BYTES_BIG_ENDIAN)
4212 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
4213 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
4216 lr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, lr_mask),
4217 size_int (xlr_bitpos), 0);
4218 rr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, rr_mask),
4219 size_int (xrr_bitpos), 0);
4221 /* Make a mask that corresponds to both fields being compared.
4222 Do this for both items being compared. If the operands are the
4223 same size and the bits being compared are in the same position
4224 then we can do this by masking both and comparing the masked
4226 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4227 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
4228 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
4230 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4231 ll_unsignedp || rl_unsignedp);
4232 if (! all_ones_mask_p (ll_mask, lnbitsize))
4233 lhs = build (BIT_AND_EXPR, lntype, lhs, ll_mask);
4235 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
4236 lr_unsignedp || rr_unsignedp);
4237 if (! all_ones_mask_p (lr_mask, rnbitsize))
4238 rhs = build (BIT_AND_EXPR, rntype, rhs, lr_mask);
4240 return build (wanted_code, truth_type, lhs, rhs);
4243 /* There is still another way we can do something: If both pairs of
4244 fields being compared are adjacent, we may be able to make a wider
4245 field containing them both.
4247 Note that we still must mask the lhs/rhs expressions. Furthermore,
4248 the mask must be shifted to account for the shift done by
4249 make_bit_field_ref. */
4250 if ((ll_bitsize + ll_bitpos == rl_bitpos
4251 && lr_bitsize + lr_bitpos == rr_bitpos)
4252 || (ll_bitpos == rl_bitpos + rl_bitsize
4253 && lr_bitpos == rr_bitpos + rr_bitsize))
4257 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
4258 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
4259 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
4260 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
4262 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
4263 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
4264 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
4265 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
4267 /* Convert to the smaller type before masking out unwanted bits. */
4269 if (lntype != rntype)
4271 if (lnbitsize > rnbitsize)
4273 lhs = fold_convert (rntype, lhs);
4274 ll_mask = fold_convert (rntype, ll_mask);
4277 else if (lnbitsize < rnbitsize)
4279 rhs = fold_convert (lntype, rhs);
4280 lr_mask = fold_convert (lntype, lr_mask);
4285 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
4286 lhs = build (BIT_AND_EXPR, type, lhs, ll_mask);
4288 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
4289 rhs = build (BIT_AND_EXPR, type, rhs, lr_mask);
4291 return build (wanted_code, truth_type, lhs, rhs);
4297 /* Handle the case of comparisons with constants. If there is something in
4298 common between the masks, those bits of the constants must be the same.
4299 If not, the condition is always false. Test for this to avoid generating
4300 incorrect code below. */
4301 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
4302 if (! integer_zerop (result)
4303 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
4304 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
4306 if (wanted_code == NE_EXPR)
4308 warning ("`or' of unmatched not-equal tests is always 1");
4309 return fold_convert (truth_type, integer_one_node);
4313 warning ("`and' of mutually exclusive equal-tests is always 0");
4314 return fold_convert (truth_type, integer_zero_node);
4318 /* Construct the expression we will return. First get the component
4319 reference we will make. Unless the mask is all ones the width of
4320 that field, perform the mask operation. Then compare with the
4322 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4323 ll_unsignedp || rl_unsignedp);
4325 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4326 if (! all_ones_mask_p (ll_mask, lnbitsize))
4327 result = build (BIT_AND_EXPR, lntype, result, ll_mask);
4329 return build (wanted_code, truth_type, result,
4330 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
4333 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
4337 optimize_minmax_comparison (tree t)
4339 tree type = TREE_TYPE (t);
4340 tree arg0 = TREE_OPERAND (t, 0);
4341 enum tree_code op_code;
4342 tree comp_const = TREE_OPERAND (t, 1);
4344 int consts_equal, consts_lt;
4347 STRIP_SIGN_NOPS (arg0);
4349 op_code = TREE_CODE (arg0);
4350 minmax_const = TREE_OPERAND (arg0, 1);
4351 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
4352 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
4353 inner = TREE_OPERAND (arg0, 0);
4355 /* If something does not permit us to optimize, return the original tree. */
4356 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
4357 || TREE_CODE (comp_const) != INTEGER_CST
4358 || TREE_CONSTANT_OVERFLOW (comp_const)
4359 || TREE_CODE (minmax_const) != INTEGER_CST
4360 || TREE_CONSTANT_OVERFLOW (minmax_const))
4363 /* Now handle all the various comparison codes. We only handle EQ_EXPR
4364 and GT_EXPR, doing the rest with recursive calls using logical
4366 switch (TREE_CODE (t))
4368 case NE_EXPR: case LT_EXPR: case LE_EXPR:
4370 invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t)));
4374 fold (build (TRUTH_ORIF_EXPR, type,
4375 optimize_minmax_comparison
4376 (build (EQ_EXPR, type, arg0, comp_const)),
4377 optimize_minmax_comparison
4378 (build (GT_EXPR, type, arg0, comp_const))));
4381 if (op_code == MAX_EXPR && consts_equal)
4382 /* MAX (X, 0) == 0 -> X <= 0 */
4383 return fold (build (LE_EXPR, type, inner, comp_const));
4385 else if (op_code == MAX_EXPR && consts_lt)
4386 /* MAX (X, 0) == 5 -> X == 5 */
4387 return fold (build (EQ_EXPR, type, inner, comp_const));
4389 else if (op_code == MAX_EXPR)
4390 /* MAX (X, 0) == -1 -> false */
4391 return omit_one_operand (type, integer_zero_node, inner);
4393 else if (consts_equal)
4394 /* MIN (X, 0) == 0 -> X >= 0 */
4395 return fold (build (GE_EXPR, type, inner, comp_const));
4398 /* MIN (X, 0) == 5 -> false */
4399 return omit_one_operand (type, integer_zero_node, inner);
4402 /* MIN (X, 0) == -1 -> X == -1 */
4403 return fold (build (EQ_EXPR, type, inner, comp_const));
4406 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
4407 /* MAX (X, 0) > 0 -> X > 0
4408 MAX (X, 0) > 5 -> X > 5 */
4409 return fold (build (GT_EXPR, type, inner, comp_const));
4411 else if (op_code == MAX_EXPR)
4412 /* MAX (X, 0) > -1 -> true */
4413 return omit_one_operand (type, integer_one_node, inner);
4415 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
4416 /* MIN (X, 0) > 0 -> false
4417 MIN (X, 0) > 5 -> false */
4418 return omit_one_operand (type, integer_zero_node, inner);
4421 /* MIN (X, 0) > -1 -> X > -1 */
4422 return fold (build (GT_EXPR, type, inner, comp_const));
4429 /* T is an integer expression that is being multiplied, divided, or taken a
4430 modulus (CODE says which and what kind of divide or modulus) by a
4431 constant C. See if we can eliminate that operation by folding it with
4432 other operations already in T. WIDE_TYPE, if non-null, is a type that
4433 should be used for the computation if wider than our type.
4435 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
4436 (X * 2) + (Y * 4). We must, however, be assured that either the original
4437 expression would not overflow or that overflow is undefined for the type
4438 in the language in question.
4440 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
4441 the machine has a multiply-accumulate insn or that this is part of an
4442 addressing calculation.
4444 If we return a non-null expression, it is an equivalent form of the
4445 original computation, but need not be in the original type. */
4448 extract_muldiv (tree t, tree c, enum tree_code code, tree wide_type)
4450 /* To avoid exponential search depth, refuse to allow recursion past
4451 three levels. Beyond that (1) it's highly unlikely that we'll find
4452 something interesting and (2) we've probably processed it before
4453 when we built the inner expression. */
4462 ret = extract_muldiv_1 (t, c, code, wide_type);
4469 extract_muldiv_1 (tree t, tree c, enum tree_code code, tree wide_type)
4471 tree type = TREE_TYPE (t);
4472 enum tree_code tcode = TREE_CODE (t);
4473 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
4474 > GET_MODE_SIZE (TYPE_MODE (type)))
4475 ? wide_type : type);
4477 int same_p = tcode == code;
4478 tree op0 = NULL_TREE, op1 = NULL_TREE;
4480 /* Don't deal with constants of zero here; they confuse the code below. */
4481 if (integer_zerop (c))
4484 if (TREE_CODE_CLASS (tcode) == '1')
4485 op0 = TREE_OPERAND (t, 0);
4487 if (TREE_CODE_CLASS (tcode) == '2')
4488 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
4490 /* Note that we need not handle conditional operations here since fold
4491 already handles those cases. So just do arithmetic here. */
4495 /* For a constant, we can always simplify if we are a multiply
4496 or (for divide and modulus) if it is a multiple of our constant. */
4497 if (code == MULT_EXPR
4498 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
4499 return const_binop (code, fold_convert (ctype, t),
4500 fold_convert (ctype, c), 0);
4503 case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
4504 /* If op0 is an expression ... */
4505 if ((TREE_CODE_CLASS (TREE_CODE (op0)) == '<'
4506 || TREE_CODE_CLASS (TREE_CODE (op0)) == '1'
4507 || TREE_CODE_CLASS (TREE_CODE (op0)) == '2'
4508 || TREE_CODE_CLASS (TREE_CODE (op0)) == 'e')
4509 /* ... and is unsigned, and its type is smaller than ctype,
4510 then we cannot pass through as widening. */
4511 && ((TYPE_UNSIGNED (TREE_TYPE (op0))
4512 && ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
4513 && TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
4514 && (GET_MODE_SIZE (TYPE_MODE (ctype))
4515 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
4516 /* ... or its type is larger than ctype,
4517 then we cannot pass through this truncation. */
4518 || (GET_MODE_SIZE (TYPE_MODE (ctype))
4519 < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0))))
4520 /* ... or signedness changes for division or modulus,
4521 then we cannot pass through this conversion. */
4522 || (code != MULT_EXPR
4523 && (TYPE_UNSIGNED (ctype)
4524 != TYPE_UNSIGNED (TREE_TYPE (op0))))))
4527 /* Pass the constant down and see if we can make a simplification. If
4528 we can, replace this expression with the inner simplification for
4529 possible later conversion to our or some other type. */
4530 if ((t2 = fold_convert (TREE_TYPE (op0), c)) != 0
4531 && TREE_CODE (t2) == INTEGER_CST
4532 && ! TREE_CONSTANT_OVERFLOW (t2)
4533 && (0 != (t1 = extract_muldiv (op0, t2, code,
4535 ? ctype : NULL_TREE))))
4539 case NEGATE_EXPR: case ABS_EXPR:
4540 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4541 return fold (build1 (tcode, ctype, fold_convert (ctype, t1)));
4544 case MIN_EXPR: case MAX_EXPR:
4545 /* If widening the type changes the signedness, then we can't perform
4546 this optimization as that changes the result. */
4547 if (TYPE_UNSIGNED (ctype) != TYPE_UNSIGNED (type))
4550 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
4551 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0
4552 && (t2 = extract_muldiv (op1, c, code, wide_type)) != 0)
4554 if (tree_int_cst_sgn (c) < 0)
4555 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
4557 return fold (build (tcode, ctype, fold_convert (ctype, t1),
4558 fold_convert (ctype, t2)));
4562 case LSHIFT_EXPR: case RSHIFT_EXPR:
4563 /* If the second operand is constant, this is a multiplication
4564 or floor division, by a power of two, so we can treat it that
4565 way unless the multiplier or divisor overflows. */
4566 if (TREE_CODE (op1) == INTEGER_CST
4567 /* const_binop may not detect overflow correctly,
4568 so check for it explicitly here. */
4569 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
4570 && TREE_INT_CST_HIGH (op1) == 0
4571 && 0 != (t1 = fold_convert (ctype,
4572 const_binop (LSHIFT_EXPR,
4575 && ! TREE_OVERFLOW (t1))
4576 return extract_muldiv (build (tcode == LSHIFT_EXPR
4577 ? MULT_EXPR : FLOOR_DIV_EXPR,
4578 ctype, fold_convert (ctype, op0), t1),
4579 c, code, wide_type);
4582 case PLUS_EXPR: case MINUS_EXPR:
4583 /* See if we can eliminate the operation on both sides. If we can, we
4584 can return a new PLUS or MINUS. If we can't, the only remaining
4585 cases where we can do anything are if the second operand is a
4587 t1 = extract_muldiv (op0, c, code, wide_type);
4588 t2 = extract_muldiv (op1, c, code, wide_type);
4589 if (t1 != 0 && t2 != 0
4590 && (code == MULT_EXPR
4591 /* If not multiplication, we can only do this if both operands
4592 are divisible by c. */
4593 || (multiple_of_p (ctype, op0, c)
4594 && multiple_of_p (ctype, op1, c))))
4595 return fold (build (tcode, ctype, fold_convert (ctype, t1),
4596 fold_convert (ctype, t2)));
4598 /* If this was a subtraction, negate OP1 and set it to be an addition.
4599 This simplifies the logic below. */
4600 if (tcode == MINUS_EXPR)
4601 tcode = PLUS_EXPR, op1 = negate_expr (op1);
4603 if (TREE_CODE (op1) != INTEGER_CST)
4606 /* If either OP1 or C are negative, this optimization is not safe for
4607 some of the division and remainder types while for others we need
4608 to change the code. */
4609 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
4611 if (code == CEIL_DIV_EXPR)
4612 code = FLOOR_DIV_EXPR;
4613 else if (code == FLOOR_DIV_EXPR)
4614 code = CEIL_DIV_EXPR;
4615 else if (code != MULT_EXPR
4616 && code != CEIL_MOD_EXPR && code != FLOOR_MOD_EXPR)
4620 /* If it's a multiply or a division/modulus operation of a multiple
4621 of our constant, do the operation and verify it doesn't overflow. */
4622 if (code == MULT_EXPR
4623 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4625 op1 = const_binop (code, fold_convert (ctype, op1),
4626 fold_convert (ctype, c), 0);
4627 /* We allow the constant to overflow with wrapping semantics. */
4629 || (TREE_OVERFLOW (op1) && ! flag_wrapv))
4635 /* If we have an unsigned type is not a sizetype, we cannot widen
4636 the operation since it will change the result if the original
4637 computation overflowed. */
4638 if (TYPE_UNSIGNED (ctype)
4639 && ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
4643 /* If we were able to eliminate our operation from the first side,
4644 apply our operation to the second side and reform the PLUS. */
4645 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
4646 return fold (build (tcode, ctype, fold_convert (ctype, t1), op1));
4648 /* The last case is if we are a multiply. In that case, we can
4649 apply the distributive law to commute the multiply and addition
4650 if the multiplication of the constants doesn't overflow. */
4651 if (code == MULT_EXPR)
4652 return fold (build (tcode, ctype,
4653 fold (build (code, ctype,
4654 fold_convert (ctype, op0),
4655 fold_convert (ctype, c))),
4661 /* We have a special case here if we are doing something like
4662 (C * 8) % 4 since we know that's zero. */
4663 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
4664 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
4665 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
4666 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4667 return omit_one_operand (type, integer_zero_node, op0);
4669 /* ... fall through ... */
4671 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
4672 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
4673 /* If we can extract our operation from the LHS, do so and return a
4674 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
4675 do something only if the second operand is a constant. */
4677 && (t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4678 return fold (build (tcode, ctype, fold_convert (ctype, t1),
4679 fold_convert (ctype, op1)));
4680 else if (tcode == MULT_EXPR && code == MULT_EXPR
4681 && (t1 = extract_muldiv (op1, c, code, wide_type)) != 0)
4682 return fold (build (tcode, ctype, fold_convert (ctype, op0),
4683 fold_convert (ctype, t1)));
4684 else if (TREE_CODE (op1) != INTEGER_CST)
4687 /* If these are the same operation types, we can associate them
4688 assuming no overflow. */
4690 && 0 != (t1 = const_binop (MULT_EXPR, fold_convert (ctype, op1),
4691 fold_convert (ctype, c), 0))
4692 && ! TREE_OVERFLOW (t1))
4693 return fold (build (tcode, ctype, fold_convert (ctype, op0), t1));
4695 /* If these operations "cancel" each other, we have the main
4696 optimizations of this pass, which occur when either constant is a
4697 multiple of the other, in which case we replace this with either an
4698 operation or CODE or TCODE.
4700 If we have an unsigned type that is not a sizetype, we cannot do
4701 this since it will change the result if the original computation
4703 if ((! TYPE_UNSIGNED (ctype)
4704 || (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
4706 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
4707 || (tcode == MULT_EXPR
4708 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
4709 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR)))
4711 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4712 return fold (build (tcode, ctype, fold_convert (ctype, op0),
4713 fold_convert (ctype,
4714 const_binop (TRUNC_DIV_EXPR,
4716 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
4717 return fold (build (code, ctype, fold_convert (ctype, op0),
4718 fold_convert (ctype,
4719 const_binop (TRUNC_DIV_EXPR,
4731 /* If T contains a COMPOUND_EXPR which was inserted merely to evaluate
4732 S, a SAVE_EXPR, return the expression actually being evaluated. Note
4733 that we may sometimes modify the tree. */
4736 strip_compound_expr (tree t, tree s)
4738 enum tree_code code = TREE_CODE (t);
4740 /* See if this is the COMPOUND_EXPR we want to eliminate. */
4741 if (code == COMPOUND_EXPR && TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR
4742 && TREE_OPERAND (TREE_OPERAND (t, 0), 0) == s)
4743 return TREE_OPERAND (t, 1);
4745 /* See if this is a COND_EXPR or a simple arithmetic operator. We
4746 don't bother handling any other types. */
4747 else if (code == COND_EXPR)
4749 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4750 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4751 TREE_OPERAND (t, 2) = strip_compound_expr (TREE_OPERAND (t, 2), s);
4753 else if (TREE_CODE_CLASS (code) == '1')
4754 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4755 else if (TREE_CODE_CLASS (code) == '<'
4756 || TREE_CODE_CLASS (code) == '2')
4758 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4759 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4765 /* Return a node which has the indicated constant VALUE (either 0 or
4766 1), and is of the indicated TYPE. */
4769 constant_boolean_node (int value, tree type)
4771 if (type == integer_type_node)
4772 return value ? integer_one_node : integer_zero_node;
4773 else if (TREE_CODE (type) == BOOLEAN_TYPE)
4774 return lang_hooks.truthvalue_conversion (value ? integer_one_node
4775 : integer_zero_node);
4778 tree t = build_int_2 (value, 0);
4780 TREE_TYPE (t) = type;
4785 /* Utility function for the following routine, to see how complex a nesting of
4786 COND_EXPRs can be. EXPR is the expression and LIMIT is a count beyond which
4787 we don't care (to avoid spending too much time on complex expressions.). */
4790 count_cond (tree expr, int lim)
4794 if (TREE_CODE (expr) != COND_EXPR)
4799 ctrue = count_cond (TREE_OPERAND (expr, 1), lim - 1);
4800 cfalse = count_cond (TREE_OPERAND (expr, 2), lim - 1 - ctrue);
4801 return MIN (lim, 1 + ctrue + cfalse);
4804 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
4805 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
4806 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
4807 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
4808 COND is the first argument to CODE; otherwise (as in the example
4809 given here), it is the second argument. TYPE is the type of the
4810 original expression. */
4813 fold_binary_op_with_conditional_arg (enum tree_code code, tree type,
4814 tree cond, tree arg, int cond_first_p)
4816 tree test, true_value, false_value;
4817 tree lhs = NULL_TREE;
4818 tree rhs = NULL_TREE;
4819 /* In the end, we'll produce a COND_EXPR. Both arms of the
4820 conditional expression will be binary operations. The left-hand
4821 side of the expression to be executed if the condition is true
4822 will be pointed to by TRUE_LHS. Similarly, the right-hand side
4823 of the expression to be executed if the condition is true will be
4824 pointed to by TRUE_RHS. FALSE_LHS and FALSE_RHS are analogous --
4825 but apply to the expression to be executed if the conditional is
4831 /* These are the codes to use for the left-hand side and right-hand
4832 side of the COND_EXPR. Normally, they are the same as CODE. */
4833 enum tree_code lhs_code = code;
4834 enum tree_code rhs_code = code;
4835 /* And these are the types of the expressions. */
4836 tree lhs_type = type;
4837 tree rhs_type = type;
4842 true_rhs = false_rhs = &arg;
4843 true_lhs = &true_value;
4844 false_lhs = &false_value;
4848 true_lhs = false_lhs = &arg;
4849 true_rhs = &true_value;
4850 false_rhs = &false_value;
4853 if (TREE_CODE (cond) == COND_EXPR)
4855 test = TREE_OPERAND (cond, 0);
4856 true_value = TREE_OPERAND (cond, 1);
4857 false_value = TREE_OPERAND (cond, 2);
4858 /* If this operand throws an expression, then it does not make
4859 sense to try to perform a logical or arithmetic operation
4860 involving it. Instead of building `a + throw 3' for example,
4861 we simply build `a, throw 3'. */
4862 if (VOID_TYPE_P (TREE_TYPE (true_value)))
4866 lhs_code = COMPOUND_EXPR;
4867 lhs_type = void_type_node;
4872 if (VOID_TYPE_P (TREE_TYPE (false_value)))
4876 rhs_code = COMPOUND_EXPR;
4877 rhs_type = void_type_node;
4885 tree testtype = TREE_TYPE (cond);
4887 true_value = fold_convert (testtype, integer_one_node);
4888 false_value = fold_convert (testtype, integer_zero_node);
4891 /* If ARG is complex we want to make sure we only evaluate it once. Though
4892 this is only required if it is volatile, it might be more efficient even
4893 if it is not. However, if we succeed in folding one part to a constant,
4894 we do not need to make this SAVE_EXPR. Since we do this optimization
4895 primarily to see if we do end up with constant and this SAVE_EXPR
4896 interferes with later optimizations, suppressing it when we can is
4899 If we are not in a function, we can't make a SAVE_EXPR, so don't try to
4900 do so. Don't try to see if the result is a constant if an arm is a
4901 COND_EXPR since we get exponential behavior in that case. */
4903 if (saved_expr_p (arg))
4905 else if (lhs == 0 && rhs == 0
4906 && !TREE_CONSTANT (arg)
4907 && lang_hooks.decls.global_bindings_p () == 0
4908 && ((TREE_CODE (arg) != VAR_DECL && TREE_CODE (arg) != PARM_DECL)
4909 || TREE_SIDE_EFFECTS (arg)))
4911 if (TREE_CODE (true_value) != COND_EXPR)
4912 lhs = fold (build (lhs_code, lhs_type, *true_lhs, *true_rhs));
4914 if (TREE_CODE (false_value) != COND_EXPR)
4915 rhs = fold (build (rhs_code, rhs_type, *false_lhs, *false_rhs));
4917 if ((lhs == 0 || ! TREE_CONSTANT (lhs))
4918 && (rhs == 0 || !TREE_CONSTANT (rhs)))
4920 arg = save_expr (arg);
4922 save = saved_expr_p (arg);
4927 lhs = fold (build (lhs_code, lhs_type, *true_lhs, *true_rhs));
4929 rhs = fold (build (rhs_code, rhs_type, *false_lhs, *false_rhs));
4931 test = fold (build (COND_EXPR, type, test, lhs, rhs));
4933 /* If ARG involves a SAVE_EXPR, we need to ensure it is evaluated
4934 ahead of the COND_EXPR we made. Otherwise we would have it only
4935 evaluated in one branch, with the other branch using the result
4936 but missing the evaluation code. Beware that the save_expr call
4937 above might not return a SAVE_EXPR, so testing the TREE_CODE
4938 of ARG is not enough to decide here. Â */
4940 return build (COMPOUND_EXPR, type,
4941 fold_convert (void_type_node, arg),
4942 strip_compound_expr (test, arg));
4944 return fold_convert (type, test);
4948 /* Subroutine of fold() that checks for the addition of +/- 0.0.
4950 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
4951 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
4952 ADDEND is the same as X.
4954 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
4955 and finite. The problematic cases are when X is zero, and its mode
4956 has signed zeros. In the case of rounding towards -infinity,
4957 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
4958 modes, X + 0 is not the same as X because -0 + 0 is 0. */
4961 fold_real_zero_addition_p (tree type, tree addend, int negate)
4963 if (!real_zerop (addend))
4966 /* Don't allow the fold with -fsignaling-nans. */
4967 if (HONOR_SNANS (TYPE_MODE (type)))
4970 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
4971 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
4974 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
4975 if (TREE_CODE (addend) == REAL_CST
4976 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
4979 /* The mode has signed zeros, and we have to honor their sign.
4980 In this situation, there is only one case we can return true for.
4981 X - 0 is the same as X unless rounding towards -infinity is
4983 return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
4986 /* Subroutine of fold() that checks comparisons of built-in math
4987 functions against real constants.
4989 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
4990 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
4991 is the type of the result and ARG0 and ARG1 are the operands of the
4992 comparison. ARG1 must be a TREE_REAL_CST.
4994 The function returns the constant folded tree if a simplification
4995 can be made, and NULL_TREE otherwise. */
4998 fold_mathfn_compare (enum built_in_function fcode, enum tree_code code,
4999 tree type, tree arg0, tree arg1)
5003 if (BUILTIN_SQRT_P (fcode))
5005 tree arg = TREE_VALUE (TREE_OPERAND (arg0, 1));
5006 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg0));
5008 c = TREE_REAL_CST (arg1);
5009 if (REAL_VALUE_NEGATIVE (c))
5011 /* sqrt(x) < y is always false, if y is negative. */
5012 if (code == EQ_EXPR || code == LT_EXPR || code == LE_EXPR)
5013 return omit_one_operand (type,
5014 fold_convert (type, integer_zero_node),
5017 /* sqrt(x) > y is always true, if y is negative and we
5018 don't care about NaNs, i.e. negative values of x. */
5019 if (code == NE_EXPR || !HONOR_NANS (mode))
5020 return omit_one_operand (type,
5021 fold_convert (type, integer_one_node),
5024 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
5025 return fold (build (GE_EXPR, type, arg,
5026 build_real (TREE_TYPE (arg), dconst0)));
5028 else if (code == GT_EXPR || code == GE_EXPR)
5032 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
5033 real_convert (&c2, mode, &c2);
5035 if (REAL_VALUE_ISINF (c2))
5037 /* sqrt(x) > y is x == +Inf, when y is very large. */
5038 if (HONOR_INFINITIES (mode))
5039 return fold (build (EQ_EXPR, type, arg,
5040 build_real (TREE_TYPE (arg), c2)));
5042 /* sqrt(x) > y is always false, when y is very large
5043 and we don't care about infinities. */
5044 return omit_one_operand (type,
5045 fold_convert (type, integer_zero_node),
5049 /* sqrt(x) > c is the same as x > c*c. */
5050 return fold (build (code, type, arg,
5051 build_real (TREE_TYPE (arg), c2)));
5053 else if (code == LT_EXPR || code == LE_EXPR)
5057 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
5058 real_convert (&c2, mode, &c2);
5060 if (REAL_VALUE_ISINF (c2))
5062 /* sqrt(x) < y is always true, when y is a very large
5063 value and we don't care about NaNs or Infinities. */
5064 if (! HONOR_NANS (mode) && ! HONOR_INFINITIES (mode))
5065 return omit_one_operand (type,
5066 fold_convert (type, integer_one_node),
5069 /* sqrt(x) < y is x != +Inf when y is very large and we
5070 don't care about NaNs. */
5071 if (! HONOR_NANS (mode))
5072 return fold (build (NE_EXPR, type, arg,
5073 build_real (TREE_TYPE (arg), c2)));
5075 /* sqrt(x) < y is x >= 0 when y is very large and we
5076 don't care about Infinities. */
5077 if (! HONOR_INFINITIES (mode))
5078 return fold (build (GE_EXPR, type, arg,
5079 build_real (TREE_TYPE (arg), dconst0)));
5081 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
5082 if (lang_hooks.decls.global_bindings_p () != 0
5083 || CONTAINS_PLACEHOLDER_P (arg))
5086 arg = save_expr (arg);
5087 return fold (build (TRUTH_ANDIF_EXPR, type,
5088 fold (build (GE_EXPR, type, arg,
5089 build_real (TREE_TYPE (arg),
5091 fold (build (NE_EXPR, type, arg,
5092 build_real (TREE_TYPE (arg),
5096 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
5097 if (! HONOR_NANS (mode))
5098 return fold (build (code, type, arg,
5099 build_real (TREE_TYPE (arg), c2)));
5101 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
5102 if (lang_hooks.decls.global_bindings_p () == 0
5103 && ! CONTAINS_PLACEHOLDER_P (arg))
5105 arg = save_expr (arg);
5106 return fold (build (TRUTH_ANDIF_EXPR, type,
5107 fold (build (GE_EXPR, type, arg,
5108 build_real (TREE_TYPE (arg),
5110 fold (build (code, type, arg,
5111 build_real (TREE_TYPE (arg),
5120 /* Subroutine of fold() that optimizes comparisons against Infinities,
5121 either +Inf or -Inf.
5123 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
5124 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
5125 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
5127 The function returns the constant folded tree if a simplification
5128 can be made, and NULL_TREE otherwise. */
5131 fold_inf_compare (enum tree_code code, tree type, tree arg0, tree arg1)
5133 enum machine_mode mode;
5134 REAL_VALUE_TYPE max;
5138 mode = TYPE_MODE (TREE_TYPE (arg0));
5140 /* For negative infinity swap the sense of the comparison. */
5141 neg = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1));
5143 code = swap_tree_comparison (code);
5148 /* x > +Inf is always false, if with ignore sNANs. */
5149 if (HONOR_SNANS (mode))
5151 return omit_one_operand (type,
5152 fold_convert (type, integer_zero_node),
5156 /* x <= +Inf is always true, if we don't case about NaNs. */
5157 if (! HONOR_NANS (mode))
5158 return omit_one_operand (type,
5159 fold_convert (type, integer_one_node),
5162 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
5163 if (lang_hooks.decls.global_bindings_p () == 0
5164 && ! CONTAINS_PLACEHOLDER_P (arg0))
5166 arg0 = save_expr (arg0);
5167 return fold (build (EQ_EXPR, type, arg0, arg0));
5173 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
5174 real_maxval (&max, neg, mode);
5175 return fold (build (neg ? LT_EXPR : GT_EXPR, type,
5176 arg0, build_real (TREE_TYPE (arg0), max)));
5179 /* x < +Inf is always equal to x <= DBL_MAX. */
5180 real_maxval (&max, neg, mode);
5181 return fold (build (neg ? GE_EXPR : LE_EXPR, type,
5182 arg0, build_real (TREE_TYPE (arg0), max)));
5185 /* x != +Inf is always equal to !(x > DBL_MAX). */
5186 real_maxval (&max, neg, mode);
5187 if (! HONOR_NANS (mode))
5188 return fold (build (neg ? GE_EXPR : LE_EXPR, type,
5189 arg0, build_real (TREE_TYPE (arg0), max)));
5190 temp = fold (build (neg ? LT_EXPR : GT_EXPR, type,
5191 arg0, build_real (TREE_TYPE (arg0), max)));
5192 return fold (build1 (TRUTH_NOT_EXPR, type, temp));
5201 /* If CODE with arguments ARG0 and ARG1 represents a single bit
5202 equality/inequality test, then return a simplified form of
5203 the test using shifts and logical operations. Otherwise return
5204 NULL. TYPE is the desired result type. */
5207 fold_single_bit_test (enum tree_code code, tree arg0, tree arg1,
5210 /* If this is a TRUTH_NOT_EXPR, it may have a single bit test inside
5212 if (code == TRUTH_NOT_EXPR)
5214 code = TREE_CODE (arg0);
5215 if (code != NE_EXPR && code != EQ_EXPR)
5218 /* Extract the arguments of the EQ/NE. */
5219 arg1 = TREE_OPERAND (arg0, 1);
5220 arg0 = TREE_OPERAND (arg0, 0);
5222 /* This requires us to invert the code. */
5223 code = (code == EQ_EXPR ? NE_EXPR : EQ_EXPR);
5226 /* If this is testing a single bit, we can optimize the test. */
5227 if ((code == NE_EXPR || code == EQ_EXPR)
5228 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
5229 && integer_pow2p (TREE_OPERAND (arg0, 1)))
5231 tree inner = TREE_OPERAND (arg0, 0);
5232 tree type = TREE_TYPE (arg0);
5233 int bitnum = tree_log2 (TREE_OPERAND (arg0, 1));
5234 enum machine_mode operand_mode = TYPE_MODE (type);
5236 tree signed_type, unsigned_type, intermediate_type;
5239 /* If we have (A & C) != 0 where C is the sign bit of A, convert
5240 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
5241 arg00 = sign_bit_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
5242 if (arg00 != NULL_TREE)
5244 tree stype = lang_hooks.types.signed_type (TREE_TYPE (arg00));
5245 return fold (build (code == EQ_EXPR ? GE_EXPR : LT_EXPR, result_type,
5246 fold_convert (stype, arg00),
5247 fold_convert (stype, integer_zero_node)));
5250 /* At this point, we know that arg0 is not testing the sign bit. */
5251 if (TYPE_PRECISION (type) - 1 == bitnum)
5254 /* Otherwise we have (A & C) != 0 where C is a single bit,
5255 convert that into ((A >> C2) & 1). Where C2 = log2(C).
5256 Similarly for (A & C) == 0. */
5258 /* If INNER is a right shift of a constant and it plus BITNUM does
5259 not overflow, adjust BITNUM and INNER. */
5260 if (TREE_CODE (inner) == RSHIFT_EXPR
5261 && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST
5262 && TREE_INT_CST_HIGH (TREE_OPERAND (inner, 1)) == 0
5263 && bitnum < TYPE_PRECISION (type)
5264 && 0 > compare_tree_int (TREE_OPERAND (inner, 1),
5265 bitnum - TYPE_PRECISION (type)))
5267 bitnum += TREE_INT_CST_LOW (TREE_OPERAND (inner, 1));
5268 inner = TREE_OPERAND (inner, 0);
5271 /* If we are going to be able to omit the AND below, we must do our
5272 operations as unsigned. If we must use the AND, we have a choice.
5273 Normally unsigned is faster, but for some machines signed is. */
5274 #ifdef LOAD_EXTEND_OP
5275 ops_unsigned = (LOAD_EXTEND_OP (operand_mode) == SIGN_EXTEND ? 0 : 1);
5280 signed_type = lang_hooks.types.type_for_mode (operand_mode, 0);
5281 unsigned_type = lang_hooks.types.type_for_mode (operand_mode, 1);
5282 intermediate_type = ops_unsigned ? unsigned_type : signed_type;
5283 inner = fold_convert (intermediate_type, inner);
5286 inner = build (RSHIFT_EXPR, intermediate_type,
5287 inner, size_int (bitnum));
5289 if (code == EQ_EXPR)
5290 inner = build (BIT_XOR_EXPR, intermediate_type,
5291 inner, integer_one_node);
5293 /* Put the AND last so it can combine with more things. */
5294 inner = build (BIT_AND_EXPR, intermediate_type,
5295 inner, integer_one_node);
5297 /* Make sure to return the proper type. */
5298 inner = fold_convert (result_type, inner);
5305 /* Check whether we are allowed to reorder operands arg0 and arg1,
5306 such that the evaluation of arg1 occurs before arg0. */
5309 reorder_operands_p (tree arg0, tree arg1)
5311 if (! flag_evaluation_order)
5313 if (TREE_CONSTANT (arg0) || TREE_CONSTANT (arg1))
5315 return ! TREE_SIDE_EFFECTS (arg0)
5316 && ! TREE_SIDE_EFFECTS (arg1);
5319 /* Test whether it is preferable two swap two operands, ARG0 and
5320 ARG1, for example because ARG0 is an integer constant and ARG1
5321 isn't. If REORDER is true, only recommend swapping if we can
5322 evaluate the operands in reverse order. */
5325 tree_swap_operands_p (tree arg0, tree arg1, bool reorder)
5327 STRIP_SIGN_NOPS (arg0);
5328 STRIP_SIGN_NOPS (arg1);
5330 if (TREE_CODE (arg1) == INTEGER_CST)
5332 if (TREE_CODE (arg0) == INTEGER_CST)
5335 if (TREE_CODE (arg1) == REAL_CST)
5337 if (TREE_CODE (arg0) == REAL_CST)
5340 if (TREE_CODE (arg1) == COMPLEX_CST)
5342 if (TREE_CODE (arg0) == COMPLEX_CST)
5345 if (TREE_CONSTANT (arg1))
5347 if (TREE_CONSTANT (arg0))
5353 if (reorder && flag_evaluation_order
5354 && (TREE_SIDE_EFFECTS (arg0) || TREE_SIDE_EFFECTS (arg1)))
5365 /* Perform constant folding and related simplification of EXPR.
5366 The related simplifications include x*1 => x, x*0 => 0, etc.,
5367 and application of the associative law.
5368 NOP_EXPR conversions may be removed freely (as long as we
5369 are careful not to change the type of the overall expression).
5370 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
5371 but we can constant-fold them if they have constant operands. */
5373 #ifdef ENABLE_FOLD_CHECKING
5374 # define fold(x) fold_1 (x)
5375 static tree fold_1 (tree);
5381 const tree t = expr;
5382 const tree type = TREE_TYPE (expr);
5383 tree t1 = NULL_TREE;
5385 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
5386 enum tree_code code = TREE_CODE (t);
5387 int kind = TREE_CODE_CLASS (code);
5388 /* WINS will be nonzero when the switch is done
5389 if all operands are constant. */
5392 /* Don't try to process an RTL_EXPR since its operands aren't trees.
5393 Likewise for a SAVE_EXPR that's already been evaluated. */
5394 if (code == RTL_EXPR || (code == SAVE_EXPR && SAVE_EXPR_RTL (t) != 0))
5397 /* Return right away if a constant. */
5401 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
5405 /* Special case for conversion ops that can have fixed point args. */
5406 arg0 = TREE_OPERAND (t, 0);
5408 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
5410 STRIP_SIGN_NOPS (arg0);
5412 if (arg0 != 0 && TREE_CODE (arg0) == COMPLEX_CST)
5413 subop = TREE_REALPART (arg0);
5417 if (subop != 0 && TREE_CODE (subop) != INTEGER_CST
5418 && TREE_CODE (subop) != REAL_CST)
5419 /* Note that TREE_CONSTANT isn't enough:
5420 static var addresses are constant but we can't
5421 do arithmetic on them. */
5424 else if (IS_EXPR_CODE_CLASS (kind))
5426 int len = first_rtl_op (code);
5428 for (i = 0; i < len; i++)
5430 tree op = TREE_OPERAND (t, i);
5434 continue; /* Valid for CALL_EXPR, at least. */
5436 /* Strip any conversions that don't change the mode. This is
5437 safe for every expression, except for a comparison expression
5438 because its signedness is derived from its operands. So, in
5439 the latter case, only strip conversions that don't change the
5442 Note that this is done as an internal manipulation within the
5443 constant folder, in order to find the simplest representation
5444 of the arguments so that their form can be studied. In any
5445 cases, the appropriate type conversions should be put back in
5446 the tree that will get out of the constant folder. */
5448 STRIP_SIGN_NOPS (op);
5452 if (TREE_CODE (op) == COMPLEX_CST)
5453 subop = TREE_REALPART (op);
5457 if (TREE_CODE (subop) != INTEGER_CST
5458 && TREE_CODE (subop) != REAL_CST)
5459 /* Note that TREE_CONSTANT isn't enough:
5460 static var addresses are constant but we can't
5461 do arithmetic on them. */
5471 /* If this is a commutative operation, and ARG0 is a constant, move it
5472 to ARG1 to reduce the number of tests below. */
5473 if (commutative_tree_code (code)
5474 && tree_swap_operands_p (arg0, arg1, true))
5475 return fold (build (code, type, TREE_OPERAND (t, 1),
5476 TREE_OPERAND (t, 0)));
5478 /* Now WINS is set as described above,
5479 ARG0 is the first operand of EXPR,
5480 and ARG1 is the second operand (if it has more than one operand).
5482 First check for cases where an arithmetic operation is applied to a
5483 compound, conditional, or comparison operation. Push the arithmetic
5484 operation inside the compound or conditional to see if any folding
5485 can then be done. Convert comparison to conditional for this purpose.
5486 The also optimizes non-constant cases that used to be done in
5489 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
5490 one of the operands is a comparison and the other is a comparison, a
5491 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
5492 code below would make the expression more complex. Change it to a
5493 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
5494 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
5496 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
5497 || code == EQ_EXPR || code == NE_EXPR)
5498 && ((truth_value_p (TREE_CODE (arg0))
5499 && (truth_value_p (TREE_CODE (arg1))
5500 || (TREE_CODE (arg1) == BIT_AND_EXPR
5501 && integer_onep (TREE_OPERAND (arg1, 1)))))
5502 || (truth_value_p (TREE_CODE (arg1))
5503 && (truth_value_p (TREE_CODE (arg0))
5504 || (TREE_CODE (arg0) == BIT_AND_EXPR
5505 && integer_onep (TREE_OPERAND (arg0, 1)))))))
5507 tem = fold (build (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
5508 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
5512 if (code == EQ_EXPR)
5513 tem = invert_truthvalue (tem);
5518 if (TREE_CODE_CLASS (code) == '1')
5520 if (TREE_CODE (arg0) == COMPOUND_EXPR)
5521 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5522 fold (build1 (code, type, TREE_OPERAND (arg0, 1))));
5523 else if (TREE_CODE (arg0) == COND_EXPR)
5525 tree arg01 = TREE_OPERAND (arg0, 1);
5526 tree arg02 = TREE_OPERAND (arg0, 2);
5527 if (! VOID_TYPE_P (TREE_TYPE (arg01)))
5528 arg01 = fold (build1 (code, type, arg01));
5529 if (! VOID_TYPE_P (TREE_TYPE (arg02)))
5530 arg02 = fold (build1 (code, type, arg02));
5531 tem = fold (build (COND_EXPR, type, TREE_OPERAND (arg0, 0),
5534 /* If this was a conversion, and all we did was to move into
5535 inside the COND_EXPR, bring it back out. But leave it if
5536 it is a conversion from integer to integer and the
5537 result precision is no wider than a word since such a
5538 conversion is cheap and may be optimized away by combine,
5539 while it couldn't if it were outside the COND_EXPR. Then return
5540 so we don't get into an infinite recursion loop taking the
5541 conversion out and then back in. */
5543 if ((code == NOP_EXPR || code == CONVERT_EXPR
5544 || code == NON_LVALUE_EXPR)
5545 && TREE_CODE (tem) == COND_EXPR
5546 && TREE_CODE (TREE_OPERAND (tem, 1)) == code
5547 && TREE_CODE (TREE_OPERAND (tem, 2)) == code
5548 && ! VOID_TYPE_P (TREE_OPERAND (tem, 1))
5549 && ! VOID_TYPE_P (TREE_OPERAND (tem, 2))
5550 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))
5551 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 2), 0)))
5552 && ! (INTEGRAL_TYPE_P (TREE_TYPE (tem))
5554 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))))
5555 && TYPE_PRECISION (TREE_TYPE (tem)) <= BITS_PER_WORD))
5556 tem = build1 (code, type,
5558 TREE_TYPE (TREE_OPERAND
5559 (TREE_OPERAND (tem, 1), 0)),
5560 TREE_OPERAND (tem, 0),
5561 TREE_OPERAND (TREE_OPERAND (tem, 1), 0),
5562 TREE_OPERAND (TREE_OPERAND (tem, 2), 0)));
5565 else if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<')
5566 return fold (build (COND_EXPR, type, arg0,
5567 fold (build1 (code, type, integer_one_node)),
5568 fold (build1 (code, type, integer_zero_node))));
5570 else if (TREE_CODE_CLASS (code) == '<'
5571 && TREE_CODE (arg0) == COMPOUND_EXPR)
5572 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5573 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
5574 else if (TREE_CODE_CLASS (code) == '<'
5575 && TREE_CODE (arg1) == COMPOUND_EXPR)
5576 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
5577 fold (build (code, type, arg0, TREE_OPERAND (arg1, 1))));
5578 else if (TREE_CODE_CLASS (code) == '2'
5579 || TREE_CODE_CLASS (code) == '<')
5581 if (TREE_CODE (arg1) == COMPOUND_EXPR
5582 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg1, 0))
5583 && ! TREE_SIDE_EFFECTS (arg0))
5584 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
5585 fold (build (code, type,
5586 arg0, TREE_OPERAND (arg1, 1))));
5587 else if ((TREE_CODE (arg1) == COND_EXPR
5588 || (TREE_CODE_CLASS (TREE_CODE (arg1)) == '<'
5589 && TREE_CODE_CLASS (code) != '<'))
5590 && (TREE_CODE (arg0) != COND_EXPR
5591 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
5592 && (! TREE_SIDE_EFFECTS (arg0)
5593 || (lang_hooks.decls.global_bindings_p () == 0
5594 && ! CONTAINS_PLACEHOLDER_P (arg0))))
5596 fold_binary_op_with_conditional_arg (code, type, arg1, arg0,
5597 /*cond_first_p=*/0);
5598 else if (TREE_CODE (arg0) == COMPOUND_EXPR)
5599 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5600 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
5601 else if ((TREE_CODE (arg0) == COND_EXPR
5602 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
5603 && TREE_CODE_CLASS (code) != '<'))
5604 && (TREE_CODE (arg1) != COND_EXPR
5605 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
5606 && (! TREE_SIDE_EFFECTS (arg1)
5607 || (lang_hooks.decls.global_bindings_p () == 0
5608 && ! CONTAINS_PLACEHOLDER_P (arg1))))
5610 fold_binary_op_with_conditional_arg (code, type, arg0, arg1,
5611 /*cond_first_p=*/1);
5617 return fold (DECL_INITIAL (t));
5622 case FIX_TRUNC_EXPR:
5624 case FIX_FLOOR_EXPR:
5625 if (TREE_TYPE (TREE_OPERAND (t, 0)) == type)
5626 return TREE_OPERAND (t, 0);
5628 /* Handle cases of two conversions in a row. */
5629 if (TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
5630 || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR)
5632 tree inside_type = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5633 tree inter_type = TREE_TYPE (TREE_OPERAND (t, 0));
5634 int inside_int = INTEGRAL_TYPE_P (inside_type);
5635 int inside_ptr = POINTER_TYPE_P (inside_type);
5636 int inside_float = FLOAT_TYPE_P (inside_type);
5637 unsigned int inside_prec = TYPE_PRECISION (inside_type);
5638 int inside_unsignedp = TYPE_UNSIGNED (inside_type);
5639 int inter_int = INTEGRAL_TYPE_P (inter_type);
5640 int inter_ptr = POINTER_TYPE_P (inter_type);
5641 int inter_float = FLOAT_TYPE_P (inter_type);
5642 unsigned int inter_prec = TYPE_PRECISION (inter_type);
5643 int inter_unsignedp = TYPE_UNSIGNED (inter_type);
5644 int final_int = INTEGRAL_TYPE_P (type);
5645 int final_ptr = POINTER_TYPE_P (type);
5646 int final_float = FLOAT_TYPE_P (type);
5647 unsigned int final_prec = TYPE_PRECISION (type);
5648 int final_unsignedp = TYPE_UNSIGNED (type);
5650 /* In addition to the cases of two conversions in a row
5651 handled below, if we are converting something to its own
5652 type via an object of identical or wider precision, neither
5653 conversion is needed. */
5654 if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (type)
5655 && ((inter_int && final_int) || (inter_float && final_float))
5656 && inter_prec >= final_prec)
5657 return fold (build1 (code, type,
5658 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
5660 /* Likewise, if the intermediate and final types are either both
5661 float or both integer, we don't need the middle conversion if
5662 it is wider than the final type and doesn't change the signedness
5663 (for integers). Avoid this if the final type is a pointer
5664 since then we sometimes need the inner conversion. Likewise if
5665 the outer has a precision not equal to the size of its mode. */
5666 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
5667 || (inter_float && inside_float))
5668 && inter_prec >= inside_prec
5669 && (inter_float || inter_unsignedp == inside_unsignedp)
5670 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
5671 && TYPE_MODE (type) == TYPE_MODE (inter_type))
5673 return fold (build1 (code, type,
5674 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
5676 /* If we have a sign-extension of a zero-extended value, we can
5677 replace that by a single zero-extension. */
5678 if (inside_int && inter_int && final_int
5679 && inside_prec < inter_prec && inter_prec < final_prec
5680 && inside_unsignedp && !inter_unsignedp)
5681 return fold (build1 (code, type,
5682 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
5684 /* Two conversions in a row are not needed unless:
5685 - some conversion is floating-point (overstrict for now), or
5686 - the intermediate type is narrower than both initial and
5688 - the intermediate type and innermost type differ in signedness,
5689 and the outermost type is wider than the intermediate, or
5690 - the initial type is a pointer type and the precisions of the
5691 intermediate and final types differ, or
5692 - the final type is a pointer type and the precisions of the
5693 initial and intermediate types differ. */
5694 if (! inside_float && ! inter_float && ! final_float
5695 && (inter_prec > inside_prec || inter_prec > final_prec)
5696 && ! (inside_int && inter_int
5697 && inter_unsignedp != inside_unsignedp
5698 && inter_prec < final_prec)
5699 && ((inter_unsignedp && inter_prec > inside_prec)
5700 == (final_unsignedp && final_prec > inter_prec))
5701 && ! (inside_ptr && inter_prec != final_prec)
5702 && ! (final_ptr && inside_prec != inter_prec)
5703 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
5704 && TYPE_MODE (type) == TYPE_MODE (inter_type))
5706 return fold (build1 (code, type,
5707 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
5710 if (TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR
5711 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t, 0), 1))
5712 /* Detect assigning a bitfield. */
5713 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) == COMPONENT_REF
5714 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 1))))
5716 /* Don't leave an assignment inside a conversion
5717 unless assigning a bitfield. */
5718 tree prev = TREE_OPERAND (t, 0);
5719 tem = copy_node (t);
5720 TREE_OPERAND (tem, 0) = TREE_OPERAND (prev, 1);
5721 /* First do the assignment, then return converted constant. */
5722 tem = build (COMPOUND_EXPR, TREE_TYPE (tem), prev, fold (tem));
5723 TREE_NO_UNUSED_WARNING (tem) = 1;
5724 TREE_USED (tem) = 1;
5728 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
5729 constants (if x has signed type, the sign bit cannot be set
5730 in c). This folds extension into the BIT_AND_EXPR. */
5731 if (INTEGRAL_TYPE_P (type)
5732 && TREE_CODE (type) != BOOLEAN_TYPE
5733 && TREE_CODE (TREE_OPERAND (t, 0)) == BIT_AND_EXPR
5734 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 1)) == INTEGER_CST)
5736 tree and = TREE_OPERAND (t, 0);
5737 tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
5740 if (TYPE_UNSIGNED (TREE_TYPE (and))
5741 || (TYPE_PRECISION (type)
5742 <= TYPE_PRECISION (TREE_TYPE (and))))
5744 else if (TYPE_PRECISION (TREE_TYPE (and1))
5745 <= HOST_BITS_PER_WIDE_INT
5746 && host_integerp (and1, 1))
5748 unsigned HOST_WIDE_INT cst;
5750 cst = tree_low_cst (and1, 1);
5751 cst &= (HOST_WIDE_INT) -1
5752 << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
5753 change = (cst == 0);
5754 #ifdef LOAD_EXTEND_OP
5756 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
5759 tree uns = lang_hooks.types.unsigned_type (TREE_TYPE (and0));
5760 and0 = fold_convert (uns, and0);
5761 and1 = fold_convert (uns, and1);
5766 return fold (build (BIT_AND_EXPR, type,
5767 fold_convert (type, and0),
5768 fold_convert (type, and1)));
5771 tem = fold_convert_const (code, type, arg0);
5772 return tem ? tem : t;
5774 case VIEW_CONVERT_EXPR:
5775 if (TREE_CODE (TREE_OPERAND (t, 0)) == VIEW_CONVERT_EXPR)
5776 return build1 (VIEW_CONVERT_EXPR, type,
5777 TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5781 if (TREE_CODE (arg0) == CONSTRUCTOR
5782 && ! type_contains_placeholder_p (TREE_TYPE (arg0)))
5784 tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0));
5786 return TREE_VALUE (m);
5791 if (TREE_CONSTANT (t) != wins)
5793 tem = copy_node (t);
5794 TREE_CONSTANT (tem) = wins;
5800 if (negate_expr_p (arg0))
5801 return fold_convert (type, negate_expr (arg0));
5806 && (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST))
5807 return fold_abs_const (arg0, type);
5808 else if (TREE_CODE (arg0) == NEGATE_EXPR)
5809 return fold (build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0)));
5810 /* Convert fabs((double)float) into (double)fabsf(float). */
5811 else if (TREE_CODE (arg0) == NOP_EXPR
5812 && TREE_CODE (type) == REAL_TYPE)
5814 tree targ0 = strip_float_extensions (arg0);
5816 return fold_convert (type, fold (build1 (ABS_EXPR,
5820 else if (tree_expr_nonnegative_p (arg0))
5825 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
5826 return fold_convert (type, arg0);
5827 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
5828 return build (COMPLEX_EXPR, type,
5829 TREE_OPERAND (arg0, 0),
5830 negate_expr (TREE_OPERAND (arg0, 1)));
5831 else if (TREE_CODE (arg0) == COMPLEX_CST)
5832 return build_complex (type, TREE_REALPART (arg0),
5833 negate_expr (TREE_IMAGPART (arg0)));
5834 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
5835 return fold (build (TREE_CODE (arg0), type,
5836 fold (build1 (CONJ_EXPR, type,
5837 TREE_OPERAND (arg0, 0))),
5838 fold (build1 (CONJ_EXPR,
5839 type, TREE_OPERAND (arg0, 1)))));
5840 else if (TREE_CODE (arg0) == CONJ_EXPR)
5841 return TREE_OPERAND (arg0, 0);
5847 tem = build_int_2 (~ TREE_INT_CST_LOW (arg0),
5848 ~ TREE_INT_CST_HIGH (arg0));
5849 TREE_TYPE (tem) = type;
5850 force_fit_type (tem, 0);
5851 TREE_OVERFLOW (tem) = TREE_OVERFLOW (arg0);
5852 TREE_CONSTANT_OVERFLOW (tem) = TREE_CONSTANT_OVERFLOW (arg0);
5855 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
5856 return TREE_OPERAND (arg0, 0);
5860 /* A + (-B) -> A - B */
5861 if (TREE_CODE (arg1) == NEGATE_EXPR)
5862 return fold (build (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5863 /* (-A) + B -> B - A */
5864 if (TREE_CODE (arg0) == NEGATE_EXPR
5865 && reorder_operands_p (TREE_OPERAND (arg0, 0), arg1))
5866 return fold (build (MINUS_EXPR, type, arg1, TREE_OPERAND (arg0, 0)));
5867 if (! FLOAT_TYPE_P (type))
5869 if (integer_zerop (arg1))
5870 return non_lvalue (fold_convert (type, arg0));
5872 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
5873 with a constant, and the two constants have no bits in common,
5874 we should treat this as a BIT_IOR_EXPR since this may produce more
5876 if (TREE_CODE (arg0) == BIT_AND_EXPR
5877 && TREE_CODE (arg1) == BIT_AND_EXPR
5878 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5879 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
5880 && integer_zerop (const_binop (BIT_AND_EXPR,
5881 TREE_OPERAND (arg0, 1),
5882 TREE_OPERAND (arg1, 1), 0)))
5884 code = BIT_IOR_EXPR;
5888 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
5889 (plus (plus (mult) (mult)) (foo)) so that we can
5890 take advantage of the factoring cases below. */
5891 if ((TREE_CODE (arg0) == PLUS_EXPR
5892 && TREE_CODE (arg1) == MULT_EXPR)
5893 || (TREE_CODE (arg1) == PLUS_EXPR
5894 && TREE_CODE (arg0) == MULT_EXPR))
5896 tree parg0, parg1, parg, marg;
5898 if (TREE_CODE (arg0) == PLUS_EXPR)
5899 parg = arg0, marg = arg1;
5901 parg = arg1, marg = arg0;
5902 parg0 = TREE_OPERAND (parg, 0);
5903 parg1 = TREE_OPERAND (parg, 1);
5907 if (TREE_CODE (parg0) == MULT_EXPR
5908 && TREE_CODE (parg1) != MULT_EXPR)
5909 return fold (build (PLUS_EXPR, type,
5910 fold (build (PLUS_EXPR, type,
5911 fold_convert (type, parg0),
5912 fold_convert (type, marg))),
5913 fold_convert (type, parg1)));
5914 if (TREE_CODE (parg0) != MULT_EXPR
5915 && TREE_CODE (parg1) == MULT_EXPR)
5916 return fold (build (PLUS_EXPR, type,
5917 fold (build (PLUS_EXPR, type,
5918 fold_convert (type, parg1),
5919 fold_convert (type, marg))),
5920 fold_convert (type, parg0)));
5923 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR)
5925 tree arg00, arg01, arg10, arg11;
5926 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
5928 /* (A * C) + (B * C) -> (A+B) * C.
5929 We are most concerned about the case where C is a constant,
5930 but other combinations show up during loop reduction. Since
5931 it is not difficult, try all four possibilities. */
5933 arg00 = TREE_OPERAND (arg0, 0);
5934 arg01 = TREE_OPERAND (arg0, 1);
5935 arg10 = TREE_OPERAND (arg1, 0);
5936 arg11 = TREE_OPERAND (arg1, 1);
5939 if (operand_equal_p (arg01, arg11, 0))
5940 same = arg01, alt0 = arg00, alt1 = arg10;
5941 else if (operand_equal_p (arg00, arg10, 0))
5942 same = arg00, alt0 = arg01, alt1 = arg11;
5943 else if (operand_equal_p (arg00, arg11, 0))
5944 same = arg00, alt0 = arg01, alt1 = arg10;
5945 else if (operand_equal_p (arg01, arg10, 0))
5946 same = arg01, alt0 = arg00, alt1 = arg11;
5948 /* No identical multiplicands; see if we can find a common
5949 power-of-two factor in non-power-of-two multiplies. This
5950 can help in multi-dimensional array access. */
5951 else if (TREE_CODE (arg01) == INTEGER_CST
5952 && TREE_CODE (arg11) == INTEGER_CST
5953 && TREE_INT_CST_HIGH (arg01) == 0
5954 && TREE_INT_CST_HIGH (arg11) == 0)
5956 HOST_WIDE_INT int01, int11, tmp;
5957 int01 = TREE_INT_CST_LOW (arg01);
5958 int11 = TREE_INT_CST_LOW (arg11);
5960 /* Move min of absolute values to int11. */
5961 if ((int01 >= 0 ? int01 : -int01)
5962 < (int11 >= 0 ? int11 : -int11))
5964 tmp = int01, int01 = int11, int11 = tmp;
5965 alt0 = arg00, arg00 = arg10, arg10 = alt0;
5966 alt0 = arg01, arg01 = arg11, arg11 = alt0;
5969 if (exact_log2 (int11) > 0 && int01 % int11 == 0)
5971 alt0 = fold (build (MULT_EXPR, type, arg00,
5972 build_int_2 (int01 / int11, 0)));
5979 return fold (build (MULT_EXPR, type,
5980 fold (build (PLUS_EXPR, type, alt0, alt1)),
5986 /* See if ARG1 is zero and X + ARG1 reduces to X. */
5987 if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
5988 return non_lvalue (fold_convert (type, arg0));
5990 /* Likewise if the operands are reversed. */
5991 if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
5992 return non_lvalue (fold_convert (type, arg1));
5994 /* Convert x+x into x*2.0. */
5995 if (operand_equal_p (arg0, arg1, 0)
5996 && SCALAR_FLOAT_TYPE_P (type))
5997 return fold (build (MULT_EXPR, type, arg0,
5998 build_real (type, dconst2)));
6000 /* Convert x*c+x into x*(c+1). */
6001 if (flag_unsafe_math_optimizations
6002 && TREE_CODE (arg0) == MULT_EXPR
6003 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
6004 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0, 1))
6005 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
6009 c = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
6010 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
6011 return fold (build (MULT_EXPR, type, arg1,
6012 build_real (type, c)));
6015 /* Convert x+x*c into x*(c+1). */
6016 if (flag_unsafe_math_optimizations
6017 && TREE_CODE (arg1) == MULT_EXPR
6018 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST
6019 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1, 1))
6020 && operand_equal_p (TREE_OPERAND (arg1, 0), arg0, 0))
6024 c = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
6025 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
6026 return fold (build (MULT_EXPR, type, arg0,
6027 build_real (type, c)));
6030 /* Convert x*c1+x*c2 into x*(c1+c2). */
6031 if (flag_unsafe_math_optimizations
6032 && TREE_CODE (arg0) == MULT_EXPR
6033 && TREE_CODE (arg1) == MULT_EXPR
6034 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
6035 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0, 1))
6036 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST
6037 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1, 1))
6038 && operand_equal_p (TREE_OPERAND (arg0, 0),
6039 TREE_OPERAND (arg1, 0), 0))
6041 REAL_VALUE_TYPE c1, c2;
6043 c1 = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
6044 c2 = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
6045 real_arithmetic (&c1, PLUS_EXPR, &c1, &c2);
6046 return fold (build (MULT_EXPR, type,
6047 TREE_OPERAND (arg0, 0),
6048 build_real (type, c1)));
6050 /* Convert a + (b*c + d*e) into (a + b*c) + d*e */
6051 if (flag_unsafe_math_optimizations
6052 && TREE_CODE (arg1) == PLUS_EXPR
6053 && TREE_CODE (arg0) != MULT_EXPR)
6055 tree tree10 = TREE_OPERAND (arg1, 0);
6056 tree tree11 = TREE_OPERAND (arg1, 1);
6057 if (TREE_CODE (tree11) == MULT_EXPR
6058 && TREE_CODE (tree10) == MULT_EXPR)
6061 tree0 = fold (build (PLUS_EXPR, type, arg0, tree10));
6062 return fold (build (PLUS_EXPR, type, tree0, tree11));
6065 /* Convert (b*c + d*e) + a into b*c + (d*e +a) */
6066 if (flag_unsafe_math_optimizations
6067 && TREE_CODE (arg0) == PLUS_EXPR
6068 && TREE_CODE (arg1) != MULT_EXPR)
6070 tree tree00 = TREE_OPERAND (arg0, 0);
6071 tree tree01 = TREE_OPERAND (arg0, 1);
6072 if (TREE_CODE (tree01) == MULT_EXPR
6073 && TREE_CODE (tree00) == MULT_EXPR)
6076 tree0 = fold (build (PLUS_EXPR, type, tree01, arg1));
6077 return fold (build (PLUS_EXPR, type, tree00, tree0));
6083 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
6084 is a rotate of A by C1 bits. */
6085 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
6086 is a rotate of A by B bits. */
6088 enum tree_code code0, code1;
6089 code0 = TREE_CODE (arg0);
6090 code1 = TREE_CODE (arg1);
6091 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
6092 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
6093 && operand_equal_p (TREE_OPERAND (arg0, 0),
6094 TREE_OPERAND (arg1, 0), 0)
6095 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
6097 tree tree01, tree11;
6098 enum tree_code code01, code11;
6100 tree01 = TREE_OPERAND (arg0, 1);
6101 tree11 = TREE_OPERAND (arg1, 1);
6102 STRIP_NOPS (tree01);
6103 STRIP_NOPS (tree11);
6104 code01 = TREE_CODE (tree01);
6105 code11 = TREE_CODE (tree11);
6106 if (code01 == INTEGER_CST
6107 && code11 == INTEGER_CST
6108 && TREE_INT_CST_HIGH (tree01) == 0
6109 && TREE_INT_CST_HIGH (tree11) == 0
6110 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
6111 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
6112 return build (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
6113 code0 == LSHIFT_EXPR ? tree01 : tree11);
6114 else if (code11 == MINUS_EXPR)
6116 tree tree110, tree111;
6117 tree110 = TREE_OPERAND (tree11, 0);
6118 tree111 = TREE_OPERAND (tree11, 1);
6119 STRIP_NOPS (tree110);
6120 STRIP_NOPS (tree111);
6121 if (TREE_CODE (tree110) == INTEGER_CST
6122 && 0 == compare_tree_int (tree110,
6124 (TREE_TYPE (TREE_OPERAND
6126 && operand_equal_p (tree01, tree111, 0))
6127 return build ((code0 == LSHIFT_EXPR
6130 type, TREE_OPERAND (arg0, 0), tree01);
6132 else if (code01 == MINUS_EXPR)
6134 tree tree010, tree011;
6135 tree010 = TREE_OPERAND (tree01, 0);
6136 tree011 = TREE_OPERAND (tree01, 1);
6137 STRIP_NOPS (tree010);
6138 STRIP_NOPS (tree011);
6139 if (TREE_CODE (tree010) == INTEGER_CST
6140 && 0 == compare_tree_int (tree010,
6142 (TREE_TYPE (TREE_OPERAND
6144 && operand_equal_p (tree11, tree011, 0))
6145 return build ((code0 != LSHIFT_EXPR
6148 type, TREE_OPERAND (arg0, 0), tree11);
6154 /* In most languages, can't associate operations on floats through
6155 parentheses. Rather than remember where the parentheses were, we
6156 don't associate floats at all, unless the user has specified
6157 -funsafe-math-optimizations. */
6160 && (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
6162 tree var0, con0, lit0, minus_lit0;
6163 tree var1, con1, lit1, minus_lit1;
6165 /* Split both trees into variables, constants, and literals. Then
6166 associate each group together, the constants with literals,
6167 then the result with variables. This increases the chances of
6168 literals being recombined later and of generating relocatable
6169 expressions for the sum of a constant and literal. */
6170 var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
6171 var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
6172 code == MINUS_EXPR);
6174 /* Only do something if we found more than two objects. Otherwise,
6175 nothing has changed and we risk infinite recursion. */
6176 if (2 < ((var0 != 0) + (var1 != 0)
6177 + (con0 != 0) + (con1 != 0)
6178 + (lit0 != 0) + (lit1 != 0)
6179 + (minus_lit0 != 0) + (minus_lit1 != 0)))
6181 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
6182 if (code == MINUS_EXPR)
6185 var0 = associate_trees (var0, var1, code, type);
6186 con0 = associate_trees (con0, con1, code, type);
6187 lit0 = associate_trees (lit0, lit1, code, type);
6188 minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
6190 /* Preserve the MINUS_EXPR if the negative part of the literal is
6191 greater than the positive part. Otherwise, the multiplicative
6192 folding code (i.e extract_muldiv) may be fooled in case
6193 unsigned constants are subtracted, like in the following
6194 example: ((X*2 + 4) - 8U)/2. */
6195 if (minus_lit0 && lit0)
6197 if (TREE_CODE (lit0) == INTEGER_CST
6198 && TREE_CODE (minus_lit0) == INTEGER_CST
6199 && tree_int_cst_lt (lit0, minus_lit0))
6201 minus_lit0 = associate_trees (minus_lit0, lit0,
6207 lit0 = associate_trees (lit0, minus_lit0,
6215 return fold_convert (type,
6216 associate_trees (var0, minus_lit0,
6220 con0 = associate_trees (con0, minus_lit0,
6222 return fold_convert (type,
6223 associate_trees (var0, con0,
6228 con0 = associate_trees (con0, lit0, code, type);
6229 return fold_convert (type, associate_trees (var0, con0,
6236 t1 = const_binop (code, arg0, arg1, 0);
6237 if (t1 != NULL_TREE)
6239 /* The return value should always have
6240 the same type as the original expression. */
6241 if (TREE_TYPE (t1) != type)
6242 t1 = fold_convert (type, t1);
6249 /* A - (-B) -> A + B */
6250 if (TREE_CODE (arg1) == NEGATE_EXPR)
6251 return fold (build (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
6252 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
6253 if (TREE_CODE (arg0) == NEGATE_EXPR
6254 && (FLOAT_TYPE_P (type)
6255 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv))
6256 && negate_expr_p (arg1)
6257 && reorder_operands_p (arg0, arg1))
6258 return fold (build (MINUS_EXPR, type, negate_expr (arg1),
6259 TREE_OPERAND (arg0, 0)));
6261 if (! FLOAT_TYPE_P (type))
6263 if (! wins && integer_zerop (arg0))
6264 return negate_expr (fold_convert (type, arg1));
6265 if (integer_zerop (arg1))
6266 return non_lvalue (fold_convert (type, arg0));
6268 /* Fold A - (A & B) into ~B & A. */
6269 if (!TREE_SIDE_EFFECTS (arg0)
6270 && TREE_CODE (arg1) == BIT_AND_EXPR)
6272 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
6273 return fold (build (BIT_AND_EXPR, type,
6274 fold (build1 (BIT_NOT_EXPR, type,
6275 TREE_OPERAND (arg1, 0))),
6277 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
6278 return fold (build (BIT_AND_EXPR, type,
6279 fold (build1 (BIT_NOT_EXPR, type,
6280 TREE_OPERAND (arg1, 1))),
6284 /* Fold (A & ~B) - (A & B) into (A ^ B) - B, where B is
6285 any power of 2 minus 1. */
6286 if (TREE_CODE (arg0) == BIT_AND_EXPR
6287 && TREE_CODE (arg1) == BIT_AND_EXPR
6288 && operand_equal_p (TREE_OPERAND (arg0, 0),
6289 TREE_OPERAND (arg1, 0), 0))
6291 tree mask0 = TREE_OPERAND (arg0, 1);
6292 tree mask1 = TREE_OPERAND (arg1, 1);
6293 tree tem = fold (build1 (BIT_NOT_EXPR, type, mask0));
6295 if (operand_equal_p (tem, mask1, 0))
6297 tem = fold (build (BIT_XOR_EXPR, type,
6298 TREE_OPERAND (arg0, 0), mask1));
6299 return fold (build (MINUS_EXPR, type, tem, mask1));
6304 /* See if ARG1 is zero and X - ARG1 reduces to X. */
6305 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
6306 return non_lvalue (fold_convert (type, arg0));
6308 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
6309 ARG0 is zero and X + ARG0 reduces to X, since that would mean
6310 (-ARG1 + ARG0) reduces to -ARG1. */
6311 else if (!wins && fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
6312 return negate_expr (fold_convert (type, arg1));
6314 /* Fold &x - &x. This can happen from &x.foo - &x.
6315 This is unsafe for certain floats even in non-IEEE formats.
6316 In IEEE, it is unsafe because it does wrong for NaNs.
6317 Also note that operand_equal_p is always false if an operand
6320 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
6321 && operand_equal_p (arg0, arg1, 0))
6322 return fold_convert (type, integer_zero_node);
6324 /* A - B -> A + (-B) if B is easily negatable. */
6325 if (!wins && negate_expr_p (arg1)
6326 && (FLOAT_TYPE_P (type)
6327 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv)))
6328 return fold (build (PLUS_EXPR, type, arg0, negate_expr (arg1)));
6330 if (TREE_CODE (arg0) == MULT_EXPR
6331 && TREE_CODE (arg1) == MULT_EXPR
6332 && (INTEGRAL_TYPE_P (type) || flag_unsafe_math_optimizations))
6334 /* (A * C) - (B * C) -> (A-B) * C. */
6335 if (operand_equal_p (TREE_OPERAND (arg0, 1),
6336 TREE_OPERAND (arg1, 1), 0))
6337 return fold (build (MULT_EXPR, type,
6338 fold (build (MINUS_EXPR, type,
6339 TREE_OPERAND (arg0, 0),
6340 TREE_OPERAND (arg1, 0))),
6341 TREE_OPERAND (arg0, 1)));
6342 /* (A * C1) - (A * C2) -> A * (C1-C2). */
6343 if (operand_equal_p (TREE_OPERAND (arg0, 0),
6344 TREE_OPERAND (arg1, 0), 0))
6345 return fold (build (MULT_EXPR, type,
6346 TREE_OPERAND (arg0, 0),
6347 fold (build (MINUS_EXPR, type,
6348 TREE_OPERAND (arg0, 1),
6349 TREE_OPERAND (arg1, 1)))));
6355 /* (-A) * (-B) -> A * B */
6356 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
6357 return fold (build (MULT_EXPR, type,
6358 TREE_OPERAND (arg0, 0),
6359 negate_expr (arg1)));
6360 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
6361 return fold (build (MULT_EXPR, type,
6363 TREE_OPERAND (arg1, 0)));
6365 if (! FLOAT_TYPE_P (type))
6367 if (integer_zerop (arg1))
6368 return omit_one_operand (type, arg1, arg0);
6369 if (integer_onep (arg1))
6370 return non_lvalue (fold_convert (type, arg0));
6372 /* (a * (1 << b)) is (a << b) */
6373 if (TREE_CODE (arg1) == LSHIFT_EXPR
6374 && integer_onep (TREE_OPERAND (arg1, 0)))
6375 return fold (build (LSHIFT_EXPR, type, arg0,
6376 TREE_OPERAND (arg1, 1)));
6377 if (TREE_CODE (arg0) == LSHIFT_EXPR
6378 && integer_onep (TREE_OPERAND (arg0, 0)))
6379 return fold (build (LSHIFT_EXPR, type, arg1,
6380 TREE_OPERAND (arg0, 1)));
6382 if (TREE_CODE (arg1) == INTEGER_CST
6383 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0),
6384 fold_convert (type, arg1),
6386 return fold_convert (type, tem);
6391 /* Maybe fold x * 0 to 0. The expressions aren't the same
6392 when x is NaN, since x * 0 is also NaN. Nor are they the
6393 same in modes with signed zeros, since multiplying a
6394 negative value by 0 gives -0, not +0. */
6395 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
6396 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
6397 && real_zerop (arg1))
6398 return omit_one_operand (type, arg1, arg0);
6399 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
6400 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
6401 && real_onep (arg1))
6402 return non_lvalue (fold_convert (type, arg0));
6404 /* Transform x * -1.0 into -x. */
6405 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
6406 && real_minus_onep (arg1))
6407 return fold (build1 (NEGATE_EXPR, type, arg0));
6409 /* Convert (C1/X)*C2 into (C1*C2)/X. */
6410 if (flag_unsafe_math_optimizations
6411 && TREE_CODE (arg0) == RDIV_EXPR
6412 && TREE_CODE (arg1) == REAL_CST
6413 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST)
6415 tree tem = const_binop (MULT_EXPR, TREE_OPERAND (arg0, 0),
6418 return fold (build (RDIV_EXPR, type, tem,
6419 TREE_OPERAND (arg0, 1)));
6422 if (flag_unsafe_math_optimizations)
6424 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
6425 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
6427 /* Optimizations of root(...)*root(...). */
6428 if (fcode0 == fcode1 && BUILTIN_ROOT_P (fcode0))
6430 tree rootfn, arg, arglist;
6431 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
6432 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
6434 /* Optimize sqrt(x)*sqrt(x) as x. */
6435 if (BUILTIN_SQRT_P (fcode0)
6436 && operand_equal_p (arg00, arg10, 0)
6437 && ! HONOR_SNANS (TYPE_MODE (type)))
6440 /* Optimize root(x)*root(y) as root(x*y). */
6441 rootfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
6442 arg = fold (build (MULT_EXPR, type, arg00, arg10));
6443 arglist = build_tree_list (NULL_TREE, arg);
6444 return build_function_call_expr (rootfn, arglist);
6447 /* Optimize expN(x)*expN(y) as expN(x+y). */
6448 if (fcode0 == fcode1 && BUILTIN_EXPONENT_P (fcode0))
6450 tree expfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
6451 tree arg = build (PLUS_EXPR, type,
6452 TREE_VALUE (TREE_OPERAND (arg0, 1)),
6453 TREE_VALUE (TREE_OPERAND (arg1, 1)));
6454 tree arglist = build_tree_list (NULL_TREE, fold (arg));
6455 return build_function_call_expr (expfn, arglist);
6458 /* Optimizations of pow(...)*pow(...). */
6459 if ((fcode0 == BUILT_IN_POW && fcode1 == BUILT_IN_POW)
6460 || (fcode0 == BUILT_IN_POWF && fcode1 == BUILT_IN_POWF)
6461 || (fcode0 == BUILT_IN_POWL && fcode1 == BUILT_IN_POWL))
6463 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
6464 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
6466 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
6467 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
6470 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
6471 if (operand_equal_p (arg01, arg11, 0))
6473 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
6474 tree arg = build (MULT_EXPR, type, arg00, arg10);
6475 tree arglist = tree_cons (NULL_TREE, fold (arg),
6476 build_tree_list (NULL_TREE,
6478 return build_function_call_expr (powfn, arglist);
6481 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
6482 if (operand_equal_p (arg00, arg10, 0))
6484 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
6485 tree arg = fold (build (PLUS_EXPR, type, arg01, arg11));
6486 tree arglist = tree_cons (NULL_TREE, arg00,
6487 build_tree_list (NULL_TREE,
6489 return build_function_call_expr (powfn, arglist);
6493 /* Optimize tan(x)*cos(x) as sin(x). */
6494 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_COS)
6495 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_COSF)
6496 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_COSL)
6497 || (fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_TAN)
6498 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_TANF)
6499 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_TANL))
6500 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
6501 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
6509 sinfn = implicit_built_in_decls[BUILT_IN_SIN];
6513 sinfn = implicit_built_in_decls[BUILT_IN_SINF];
6517 sinfn = implicit_built_in_decls[BUILT_IN_SINL];
6523 if (sinfn != NULL_TREE)
6524 return build_function_call_expr (sinfn,
6525 TREE_OPERAND (arg0, 1));
6528 /* Optimize x*pow(x,c) as pow(x,c+1). */
6529 if (fcode1 == BUILT_IN_POW
6530 || fcode1 == BUILT_IN_POWF
6531 || fcode1 == BUILT_IN_POWL)
6533 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
6534 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
6536 if (TREE_CODE (arg11) == REAL_CST
6537 && ! TREE_CONSTANT_OVERFLOW (arg11)
6538 && operand_equal_p (arg0, arg10, 0))
6540 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
6544 c = TREE_REAL_CST (arg11);
6545 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
6546 arg = build_real (type, c);
6547 arglist = build_tree_list (NULL_TREE, arg);
6548 arglist = tree_cons (NULL_TREE, arg0, arglist);
6549 return build_function_call_expr (powfn, arglist);
6553 /* Optimize pow(x,c)*x as pow(x,c+1). */
6554 if (fcode0 == BUILT_IN_POW
6555 || fcode0 == BUILT_IN_POWF
6556 || fcode0 == BUILT_IN_POWL)
6558 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
6559 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
6561 if (TREE_CODE (arg01) == REAL_CST
6562 && ! TREE_CONSTANT_OVERFLOW (arg01)
6563 && operand_equal_p (arg1, arg00, 0))
6565 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
6569 c = TREE_REAL_CST (arg01);
6570 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
6571 arg = build_real (type, c);
6572 arglist = build_tree_list (NULL_TREE, arg);
6573 arglist = tree_cons (NULL_TREE, arg1, arglist);
6574 return build_function_call_expr (powfn, arglist);
6578 /* Optimize x*x as pow(x,2.0), which is expanded as x*x. */
6580 && operand_equal_p (arg0, arg1, 0))
6584 if (type == double_type_node)
6585 powfn = implicit_built_in_decls[BUILT_IN_POW];
6586 else if (type == float_type_node)
6587 powfn = implicit_built_in_decls[BUILT_IN_POWF];
6588 else if (type == long_double_type_node)
6589 powfn = implicit_built_in_decls[BUILT_IN_POWL];
6595 tree arg = build_real (type, dconst2);
6596 tree arglist = build_tree_list (NULL_TREE, arg);
6597 arglist = tree_cons (NULL_TREE, arg0, arglist);
6598 return build_function_call_expr (powfn, arglist);
6607 if (integer_all_onesp (arg1))
6608 return omit_one_operand (type, arg1, arg0);
6609 if (integer_zerop (arg1))
6610 return non_lvalue (fold_convert (type, arg0));
6611 if (operand_equal_p (arg0, arg1, 0))
6612 return non_lvalue (fold_convert (type, arg0));
6613 t1 = distribute_bit_expr (code, type, arg0, arg1);
6614 if (t1 != NULL_TREE)
6617 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
6619 This results in more efficient code for machines without a NAND
6620 instruction. Combine will canonicalize to the first form
6621 which will allow use of NAND instructions provided by the
6622 backend if they exist. */
6623 if (TREE_CODE (arg0) == BIT_NOT_EXPR
6624 && TREE_CODE (arg1) == BIT_NOT_EXPR)
6626 return fold (build1 (BIT_NOT_EXPR, type,
6627 build (BIT_AND_EXPR, type,
6628 TREE_OPERAND (arg0, 0),
6629 TREE_OPERAND (arg1, 0))));
6632 /* See if this can be simplified into a rotate first. If that
6633 is unsuccessful continue in the association code. */
6637 if (integer_zerop (arg1))
6638 return non_lvalue (fold_convert (type, arg0));
6639 if (integer_all_onesp (arg1))
6640 return fold (build1 (BIT_NOT_EXPR, type, arg0));
6641 if (operand_equal_p (arg0, arg1, 0))
6642 return omit_one_operand (type, integer_zero_node, arg0);
6644 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
6645 with a constant, and the two constants have no bits in common,
6646 we should treat this as a BIT_IOR_EXPR since this may produce more
6648 if (TREE_CODE (arg0) == BIT_AND_EXPR
6649 && TREE_CODE (arg1) == BIT_AND_EXPR
6650 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6651 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
6652 && integer_zerop (const_binop (BIT_AND_EXPR,
6653 TREE_OPERAND (arg0, 1),
6654 TREE_OPERAND (arg1, 1), 0)))
6656 code = BIT_IOR_EXPR;
6660 /* See if this can be simplified into a rotate first. If that
6661 is unsuccessful continue in the association code. */
6665 if (integer_all_onesp (arg1))
6666 return non_lvalue (fold_convert (type, arg0));
6667 if (integer_zerop (arg1))
6668 return omit_one_operand (type, arg1, arg0);
6669 if (operand_equal_p (arg0, arg1, 0))
6670 return non_lvalue (fold_convert (type, arg0));
6671 t1 = distribute_bit_expr (code, type, arg0, arg1);
6672 if (t1 != NULL_TREE)
6674 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
6675 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
6676 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
6679 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
6681 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
6682 && (~TREE_INT_CST_LOW (arg1)
6683 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
6684 return fold_convert (type, TREE_OPERAND (arg0, 0));
6687 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
6689 This results in more efficient code for machines without a NOR
6690 instruction. Combine will canonicalize to the first form
6691 which will allow use of NOR instructions provided by the
6692 backend if they exist. */
6693 if (TREE_CODE (arg0) == BIT_NOT_EXPR
6694 && TREE_CODE (arg1) == BIT_NOT_EXPR)
6696 return fold (build1 (BIT_NOT_EXPR, type,
6697 build (BIT_IOR_EXPR, type,
6698 TREE_OPERAND (arg0, 0),
6699 TREE_OPERAND (arg1, 0))));
6705 /* Don't touch a floating-point divide by zero unless the mode
6706 of the constant can represent infinity. */
6707 if (TREE_CODE (arg1) == REAL_CST
6708 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
6709 && real_zerop (arg1))
6712 /* (-A) / (-B) -> A / B */
6713 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
6714 return fold (build (RDIV_EXPR, type,
6715 TREE_OPERAND (arg0, 0),
6716 negate_expr (arg1)));
6717 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
6718 return fold (build (RDIV_EXPR, type,
6720 TREE_OPERAND (arg1, 0)));
6722 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
6723 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
6724 && real_onep (arg1))
6725 return non_lvalue (fold_convert (type, arg0));
6727 /* In IEEE floating point, x/-1 is not equivalent to -x for snans. */
6728 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
6729 && real_minus_onep (arg1))
6730 return non_lvalue (fold_convert (type, negate_expr (arg0)));
6732 /* If ARG1 is a constant, we can convert this to a multiply by the
6733 reciprocal. This does not have the same rounding properties,
6734 so only do this if -funsafe-math-optimizations. We can actually
6735 always safely do it if ARG1 is a power of two, but it's hard to
6736 tell if it is or not in a portable manner. */
6737 if (TREE_CODE (arg1) == REAL_CST)
6739 if (flag_unsafe_math_optimizations
6740 && 0 != (tem = const_binop (code, build_real (type, dconst1),
6742 return fold (build (MULT_EXPR, type, arg0, tem));
6743 /* Find the reciprocal if optimizing and the result is exact. */
6747 r = TREE_REAL_CST (arg1);
6748 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
6750 tem = build_real (type, r);
6751 return fold (build (MULT_EXPR, type, arg0, tem));
6755 /* Convert A/B/C to A/(B*C). */
6756 if (flag_unsafe_math_optimizations
6757 && TREE_CODE (arg0) == RDIV_EXPR)
6758 return fold (build (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
6759 fold (build (MULT_EXPR, type,
6760 TREE_OPERAND (arg0, 1), arg1))));
6762 /* Convert A/(B/C) to (A/B)*C. */
6763 if (flag_unsafe_math_optimizations
6764 && TREE_CODE (arg1) == RDIV_EXPR)
6765 return fold (build (MULT_EXPR, type,
6766 fold (build (RDIV_EXPR, type, arg0,
6767 TREE_OPERAND (arg1, 0))),
6768 TREE_OPERAND (arg1, 1)));
6770 /* Convert C1/(X*C2) into (C1/C2)/X. */
6771 if (flag_unsafe_math_optimizations
6772 && TREE_CODE (arg1) == MULT_EXPR
6773 && TREE_CODE (arg0) == REAL_CST
6774 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
6776 tree tem = const_binop (RDIV_EXPR, arg0,
6777 TREE_OPERAND (arg1, 1), 0);
6779 return fold (build (RDIV_EXPR, type, tem,
6780 TREE_OPERAND (arg1, 0)));
6783 if (flag_unsafe_math_optimizations)
6785 enum built_in_function fcode = builtin_mathfn_code (arg1);
6786 /* Optimize x/expN(y) into x*expN(-y). */
6787 if (BUILTIN_EXPONENT_P (fcode))
6789 tree expfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
6790 tree arg = build1 (NEGATE_EXPR, type,
6791 TREE_VALUE (TREE_OPERAND (arg1, 1)));
6792 tree arglist = build_tree_list (NULL_TREE, fold (arg));
6793 arg1 = build_function_call_expr (expfn, arglist);
6794 return fold (build (MULT_EXPR, type, arg0, arg1));
6797 /* Optimize x/pow(y,z) into x*pow(y,-z). */
6798 if (fcode == BUILT_IN_POW
6799 || fcode == BUILT_IN_POWF
6800 || fcode == BUILT_IN_POWL)
6802 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
6803 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
6804 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1, 1)));
6805 tree neg11 = fold (build1 (NEGATE_EXPR, type, arg11));
6806 tree arglist = tree_cons(NULL_TREE, arg10,
6807 build_tree_list (NULL_TREE, neg11));
6808 arg1 = build_function_call_expr (powfn, arglist);
6809 return fold (build (MULT_EXPR, type, arg0, arg1));
6813 if (flag_unsafe_math_optimizations)
6815 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
6816 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
6818 /* Optimize sin(x)/cos(x) as tan(x). */
6819 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_COS)
6820 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_COSF)
6821 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_COSL))
6822 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
6823 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
6827 if (fcode0 == BUILT_IN_SIN)
6828 tanfn = implicit_built_in_decls[BUILT_IN_TAN];
6829 else if (fcode0 == BUILT_IN_SINF)
6830 tanfn = implicit_built_in_decls[BUILT_IN_TANF];
6831 else if (fcode0 == BUILT_IN_SINL)
6832 tanfn = implicit_built_in_decls[BUILT_IN_TANL];
6836 if (tanfn != NULL_TREE)
6837 return build_function_call_expr (tanfn,
6838 TREE_OPERAND (arg0, 1));
6841 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
6842 if (((fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_SIN)
6843 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_SINF)
6844 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_SINL))
6845 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
6846 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
6850 if (fcode0 == BUILT_IN_COS)
6851 tanfn = implicit_built_in_decls[BUILT_IN_TAN];
6852 else if (fcode0 == BUILT_IN_COSF)
6853 tanfn = implicit_built_in_decls[BUILT_IN_TANF];
6854 else if (fcode0 == BUILT_IN_COSL)
6855 tanfn = implicit_built_in_decls[BUILT_IN_TANL];
6859 if (tanfn != NULL_TREE)
6861 tree tmp = TREE_OPERAND (arg0, 1);
6862 tmp = build_function_call_expr (tanfn, tmp);
6863 return fold (build (RDIV_EXPR, type,
6864 build_real (type, dconst1),
6869 /* Optimize pow(x,c)/x as pow(x,c-1). */
6870 if (fcode0 == BUILT_IN_POW
6871 || fcode0 == BUILT_IN_POWF
6872 || fcode0 == BUILT_IN_POWL)
6874 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
6875 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0, 1)));
6876 if (TREE_CODE (arg01) == REAL_CST
6877 && ! TREE_CONSTANT_OVERFLOW (arg01)
6878 && operand_equal_p (arg1, arg00, 0))
6880 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
6884 c = TREE_REAL_CST (arg01);
6885 real_arithmetic (&c, MINUS_EXPR, &c, &dconst1);
6886 arg = build_real (type, c);
6887 arglist = build_tree_list (NULL_TREE, arg);
6888 arglist = tree_cons (NULL_TREE, arg1, arglist);
6889 return build_function_call_expr (powfn, arglist);
6895 case TRUNC_DIV_EXPR:
6896 case ROUND_DIV_EXPR:
6897 case FLOOR_DIV_EXPR:
6899 case EXACT_DIV_EXPR:
6900 if (integer_onep (arg1))
6901 return non_lvalue (fold_convert (type, arg0));
6902 if (integer_zerop (arg1))
6905 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
6906 operation, EXACT_DIV_EXPR.
6908 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
6909 At one time others generated faster code, it's not clear if they do
6910 after the last round to changes to the DIV code in expmed.c. */
6911 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
6912 && multiple_of_p (type, arg0, arg1))
6913 return fold (build (EXACT_DIV_EXPR, type, arg0, arg1));
6915 if (TREE_CODE (arg1) == INTEGER_CST
6916 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
6918 return fold_convert (type, tem);
6923 case FLOOR_MOD_EXPR:
6924 case ROUND_MOD_EXPR:
6925 case TRUNC_MOD_EXPR:
6926 if (integer_onep (arg1))
6927 return omit_one_operand (type, integer_zero_node, arg0);
6928 if (integer_zerop (arg1))
6931 if (TREE_CODE (arg1) == INTEGER_CST
6932 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
6934 return fold_convert (type, tem);
6940 if (integer_all_onesp (arg0))
6941 return omit_one_operand (type, arg0, arg1);
6945 /* Optimize -1 >> x for arithmetic right shifts. */
6946 if (integer_all_onesp (arg0) && !TYPE_UNSIGNED (type))
6947 return omit_one_operand (type, arg0, arg1);
6948 /* ... fall through ... */
6952 if (integer_zerop (arg1))
6953 return non_lvalue (fold_convert (type, arg0));
6954 if (integer_zerop (arg0))
6955 return omit_one_operand (type, arg0, arg1);
6957 /* Since negative shift count is not well-defined,
6958 don't try to compute it in the compiler. */
6959 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
6961 /* Rewrite an LROTATE_EXPR by a constant into an
6962 RROTATE_EXPR by a new constant. */
6963 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
6965 tree tem = build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type)), 0);
6966 tem = fold_convert (TREE_TYPE (arg1), tem);
6967 tem = const_binop (MINUS_EXPR, tem, arg1, 0);
6968 return fold (build (RROTATE_EXPR, type, arg0, tem));
6971 /* If we have a rotate of a bit operation with the rotate count and
6972 the second operand of the bit operation both constant,
6973 permute the two operations. */
6974 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
6975 && (TREE_CODE (arg0) == BIT_AND_EXPR
6976 || TREE_CODE (arg0) == BIT_IOR_EXPR
6977 || TREE_CODE (arg0) == BIT_XOR_EXPR)
6978 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
6979 return fold (build (TREE_CODE (arg0), type,
6980 fold (build (code, type,
6981 TREE_OPERAND (arg0, 0), arg1)),
6982 fold (build (code, type,
6983 TREE_OPERAND (arg0, 1), arg1))));
6985 /* Two consecutive rotates adding up to the width of the mode can
6987 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
6988 && TREE_CODE (arg0) == RROTATE_EXPR
6989 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6990 && TREE_INT_CST_HIGH (arg1) == 0
6991 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
6992 && ((TREE_INT_CST_LOW (arg1)
6993 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
6994 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type))))
6995 return TREE_OPERAND (arg0, 0);
7000 if (operand_equal_p (arg0, arg1, 0))
7001 return omit_one_operand (type, arg0, arg1);
7002 if (INTEGRAL_TYPE_P (type)
7003 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), 1))
7004 return omit_one_operand (type, arg1, arg0);
7008 if (operand_equal_p (arg0, arg1, 0))
7009 return omit_one_operand (type, arg0, arg1);
7010 if (INTEGRAL_TYPE_P (type)
7011 && TYPE_MAX_VALUE (type)
7012 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), 1))
7013 return omit_one_operand (type, arg1, arg0);
7016 case TRUTH_NOT_EXPR:
7017 /* Note that the operand of this must be an int
7018 and its values must be 0 or 1.
7019 ("true" is a fixed value perhaps depending on the language,
7020 but we don't handle values other than 1 correctly yet.) */
7021 tem = invert_truthvalue (arg0);
7022 /* Avoid infinite recursion. */
7023 if (TREE_CODE (tem) == TRUTH_NOT_EXPR)
7025 tem = fold_single_bit_test (code, arg0, arg1, type);
7030 return fold_convert (type, tem);
7032 case TRUTH_ANDIF_EXPR:
7033 /* Note that the operands of this must be ints
7034 and their values must be 0 or 1.
7035 ("true" is a fixed value perhaps depending on the language.) */
7036 /* If first arg is constant zero, return it. */
7037 if (integer_zerop (arg0))
7038 return fold_convert (type, arg0);
7039 case TRUTH_AND_EXPR:
7040 /* If either arg is constant true, drop it. */
7041 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
7042 return non_lvalue (fold_convert (type, arg1));
7043 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
7044 /* Preserve sequence points. */
7045 && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
7046 return non_lvalue (fold_convert (type, arg0));
7047 /* If second arg is constant zero, result is zero, but first arg
7048 must be evaluated. */
7049 if (integer_zerop (arg1))
7050 return omit_one_operand (type, arg1, arg0);
7051 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
7052 case will be handled here. */
7053 if (integer_zerop (arg0))
7054 return omit_one_operand (type, arg0, arg1);
7057 /* We only do these simplifications if we are optimizing. */
7061 /* Check for things like (A || B) && (A || C). We can convert this
7062 to A || (B && C). Note that either operator can be any of the four
7063 truth and/or operations and the transformation will still be
7064 valid. Also note that we only care about order for the
7065 ANDIF and ORIF operators. If B contains side effects, this
7066 might change the truth-value of A. */
7067 if (TREE_CODE (arg0) == TREE_CODE (arg1)
7068 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
7069 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
7070 || TREE_CODE (arg0) == TRUTH_AND_EXPR
7071 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
7072 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
7074 tree a00 = TREE_OPERAND (arg0, 0);
7075 tree a01 = TREE_OPERAND (arg0, 1);
7076 tree a10 = TREE_OPERAND (arg1, 0);
7077 tree a11 = TREE_OPERAND (arg1, 1);
7078 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
7079 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
7080 && (code == TRUTH_AND_EXPR
7081 || code == TRUTH_OR_EXPR));
7083 if (operand_equal_p (a00, a10, 0))
7084 return fold (build (TREE_CODE (arg0), type, a00,
7085 fold (build (code, type, a01, a11))));
7086 else if (commutative && operand_equal_p (a00, a11, 0))
7087 return fold (build (TREE_CODE (arg0), type, a00,
7088 fold (build (code, type, a01, a10))));
7089 else if (commutative && operand_equal_p (a01, a10, 0))
7090 return fold (build (TREE_CODE (arg0), type, a01,
7091 fold (build (code, type, a00, a11))));
7093 /* This case if tricky because we must either have commutative
7094 operators or else A10 must not have side-effects. */
7096 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
7097 && operand_equal_p (a01, a11, 0))
7098 return fold (build (TREE_CODE (arg0), type,
7099 fold (build (code, type, a00, a10)),
7103 /* See if we can build a range comparison. */
7104 if (0 != (tem = fold_range_test (t)))
7107 /* Check for the possibility of merging component references. If our
7108 lhs is another similar operation, try to merge its rhs with our
7109 rhs. Then try to merge our lhs and rhs. */
7110 if (TREE_CODE (arg0) == code
7111 && 0 != (tem = fold_truthop (code, type,
7112 TREE_OPERAND (arg0, 1), arg1)))
7113 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
7115 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
7120 case TRUTH_ORIF_EXPR:
7121 /* Note that the operands of this must be ints
7122 and their values must be 0 or true.
7123 ("true" is a fixed value perhaps depending on the language.) */
7124 /* If first arg is constant true, return it. */
7125 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
7126 return fold_convert (type, arg0);
7128 /* If either arg is constant zero, drop it. */
7129 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
7130 return non_lvalue (fold_convert (type, arg1));
7131 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
7132 /* Preserve sequence points. */
7133 && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
7134 return non_lvalue (fold_convert (type, arg0));
7135 /* If second arg is constant true, result is true, but we must
7136 evaluate first arg. */
7137 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
7138 return omit_one_operand (type, arg1, arg0);
7139 /* Likewise for first arg, but note this only occurs here for
7141 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
7142 return omit_one_operand (type, arg0, arg1);
7145 case TRUTH_XOR_EXPR:
7146 /* If either arg is constant zero, drop it. */
7147 if (integer_zerop (arg0))
7148 return non_lvalue (fold_convert (type, arg1));
7149 if (integer_zerop (arg1))
7150 return non_lvalue (fold_convert (type, arg0));
7151 /* If either arg is constant true, this is a logical inversion. */
7152 if (integer_onep (arg0))
7153 return non_lvalue (fold_convert (type, invert_truthvalue (arg1)));
7154 if (integer_onep (arg1))
7155 return non_lvalue (fold_convert (type, invert_truthvalue (arg0)));
7164 /* If one arg is a real or integer constant, put it last. */
7165 if (tree_swap_operands_p (arg0, arg1, true))
7166 return fold (build (swap_tree_comparison (code), type, arg1, arg0));
7168 /* If this is an equality comparison of the address of a non-weak
7169 object against zero, then we know the result. */
7170 if ((code == EQ_EXPR || code == NE_EXPR)
7171 && TREE_CODE (arg0) == ADDR_EXPR
7172 && DECL_P (TREE_OPERAND (arg0, 0))
7173 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
7174 && integer_zerop (arg1))
7176 if (code == EQ_EXPR)
7177 return fold_convert (type, integer_zero_node);
7179 return fold_convert (type, integer_one_node);
7182 /* If this is an equality comparison of the address of two non-weak,
7183 unaliased symbols neither of which are extern (since we do not
7184 have access to attributes for externs), then we know the result. */
7185 if ((code == EQ_EXPR || code == NE_EXPR)
7186 && TREE_CODE (arg0) == ADDR_EXPR
7187 && DECL_P (TREE_OPERAND (arg0, 0))
7188 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
7189 && ! lookup_attribute ("alias",
7190 DECL_ATTRIBUTES (TREE_OPERAND (arg0, 0)))
7191 && ! DECL_EXTERNAL (TREE_OPERAND (arg0, 0))
7192 && TREE_CODE (arg1) == ADDR_EXPR
7193 && DECL_P (TREE_OPERAND (arg1, 0))
7194 && ! DECL_WEAK (TREE_OPERAND (arg1, 0))
7195 && ! lookup_attribute ("alias",
7196 DECL_ATTRIBUTES (TREE_OPERAND (arg1, 0)))
7197 && ! DECL_EXTERNAL (TREE_OPERAND (arg1, 0)))
7199 if (code == EQ_EXPR)
7200 return fold_convert (type, (operand_equal_p (arg0, arg1, 0)
7201 ? integer_one_node : integer_zero_node));
7203 return fold_convert (type, (operand_equal_p (arg0, arg1, 0)
7204 ? integer_zero_node : integer_one_node));
7207 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
7209 tree targ0 = strip_float_extensions (arg0);
7210 tree targ1 = strip_float_extensions (arg1);
7211 tree newtype = TREE_TYPE (targ0);
7213 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
7214 newtype = TREE_TYPE (targ1);
7216 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
7217 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
7218 return fold (build (code, type, fold_convert (newtype, targ0),
7219 fold_convert (newtype, targ1)));
7221 /* (-a) CMP (-b) -> b CMP a */
7222 if (TREE_CODE (arg0) == NEGATE_EXPR
7223 && TREE_CODE (arg1) == NEGATE_EXPR)
7224 return fold (build (code, type, TREE_OPERAND (arg1, 0),
7225 TREE_OPERAND (arg0, 0)));
7227 if (TREE_CODE (arg1) == REAL_CST)
7229 REAL_VALUE_TYPE cst;
7230 cst = TREE_REAL_CST (arg1);
7232 /* (-a) CMP CST -> a swap(CMP) (-CST) */
7233 if (TREE_CODE (arg0) == NEGATE_EXPR)
7235 fold (build (swap_tree_comparison (code), type,
7236 TREE_OPERAND (arg0, 0),
7237 build_real (TREE_TYPE (arg1),
7238 REAL_VALUE_NEGATE (cst))));
7240 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
7241 /* a CMP (-0) -> a CMP 0 */
7242 if (REAL_VALUE_MINUS_ZERO (cst))
7243 return fold (build (code, type, arg0,
7244 build_real (TREE_TYPE (arg1), dconst0)));
7246 /* x != NaN is always true, other ops are always false. */
7247 if (REAL_VALUE_ISNAN (cst)
7248 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))))
7250 tem = (code == NE_EXPR) ? integer_one_node : integer_zero_node;
7251 return omit_one_operand (type, fold_convert (type, tem), arg0);
7254 /* Fold comparisons against infinity. */
7255 if (REAL_VALUE_ISINF (cst))
7257 tem = fold_inf_compare (code, type, arg0, arg1);
7258 if (tem != NULL_TREE)
7263 /* If this is a comparison of a real constant with a PLUS_EXPR
7264 or a MINUS_EXPR of a real constant, we can convert it into a
7265 comparison with a revised real constant as long as no overflow
7266 occurs when unsafe_math_optimizations are enabled. */
7267 if (flag_unsafe_math_optimizations
7268 && TREE_CODE (arg1) == REAL_CST
7269 && (TREE_CODE (arg0) == PLUS_EXPR
7270 || TREE_CODE (arg0) == MINUS_EXPR)
7271 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
7272 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
7273 ? MINUS_EXPR : PLUS_EXPR,
7274 arg1, TREE_OPERAND (arg0, 1), 0))
7275 && ! TREE_CONSTANT_OVERFLOW (tem))
7276 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
7278 /* Likewise, we can simplify a comparison of a real constant with
7279 a MINUS_EXPR whose first operand is also a real constant, i.e.
7280 (c1 - x) < c2 becomes x > c1-c2. */
7281 if (flag_unsafe_math_optimizations
7282 && TREE_CODE (arg1) == REAL_CST
7283 && TREE_CODE (arg0) == MINUS_EXPR
7284 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST
7285 && 0 != (tem = const_binop (MINUS_EXPR, TREE_OPERAND (arg0, 0),
7287 && ! TREE_CONSTANT_OVERFLOW (tem))
7288 return fold (build (swap_tree_comparison (code), type,
7289 TREE_OPERAND (arg0, 1), tem));
7291 /* Fold comparisons against built-in math functions. */
7292 if (TREE_CODE (arg1) == REAL_CST
7293 && flag_unsafe_math_optimizations
7294 && ! flag_errno_math)
7296 enum built_in_function fcode = builtin_mathfn_code (arg0);
7298 if (fcode != END_BUILTINS)
7300 tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
7301 if (tem != NULL_TREE)
7307 /* Convert foo++ == CONST into ++foo == CONST + INCR. */
7308 if (TREE_CONSTANT (arg1)
7309 && (TREE_CODE (arg0) == POSTINCREMENT_EXPR
7310 || TREE_CODE (arg0) == POSTDECREMENT_EXPR)
7311 /* This optimization is invalid for ordered comparisons
7312 if CONST+INCR overflows or if foo+incr might overflow.
7313 This optimization is invalid for floating point due to rounding.
7314 For pointer types we assume overflow doesn't happen. */
7315 && (POINTER_TYPE_P (TREE_TYPE (arg0))
7316 || (INTEGRAL_TYPE_P (TREE_TYPE (arg0))
7317 && (code == EQ_EXPR || code == NE_EXPR))))
7319 tree varop, newconst;
7321 if (TREE_CODE (arg0) == POSTINCREMENT_EXPR)
7323 newconst = fold (build2 (PLUS_EXPR, TREE_TYPE (arg0),
7324 arg1, TREE_OPERAND (arg0, 1)));
7325 varop = build2 (PREINCREMENT_EXPR, TREE_TYPE (arg0),
7326 TREE_OPERAND (arg0, 0),
7327 TREE_OPERAND (arg0, 1));
7331 newconst = fold (build2 (MINUS_EXPR, TREE_TYPE (arg0),
7332 arg1, TREE_OPERAND (arg0, 1)));
7333 varop = build2 (PREDECREMENT_EXPR, TREE_TYPE (arg0),
7334 TREE_OPERAND (arg0, 0),
7335 TREE_OPERAND (arg0, 1));
7339 /* If VAROP is a reference to a bitfield, we must mask
7340 the constant by the width of the field. */
7341 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
7342 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (varop, 0), 1)))
7344 tree fielddecl = TREE_OPERAND (TREE_OPERAND (varop, 0), 1);
7345 int size = TREE_INT_CST_LOW (DECL_SIZE (fielddecl));
7346 tree folded_compare, shift;
7348 /* First check whether the comparison would come out
7349 always the same. If we don't do that we would
7350 change the meaning with the masking. */
7351 folded_compare = fold (build2 (code, type,
7352 TREE_OPERAND (varop, 0),
7354 if (integer_zerop (folded_compare)
7355 || integer_onep (folded_compare))
7356 return omit_one_operand (type, folded_compare, varop);
7358 shift = build_int_2 (TYPE_PRECISION (TREE_TYPE (varop)) - size,
7360 newconst = fold (build2 (LSHIFT_EXPR, TREE_TYPE (varop),
7362 newconst = fold (build2 (RSHIFT_EXPR, TREE_TYPE (varop),
7366 return fold (build2 (code, type, varop, newconst));
7369 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
7370 This transformation affects the cases which are handled in later
7371 optimizations involving comparisons with non-negative constants. */
7372 if (TREE_CODE (arg1) == INTEGER_CST
7373 && TREE_CODE (arg0) != INTEGER_CST
7374 && tree_int_cst_sgn (arg1) > 0)
7379 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
7380 return fold (build (GT_EXPR, type, arg0, arg1));
7383 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
7384 return fold (build (LE_EXPR, type, arg0, arg1));
7391 /* Comparisons with the highest or lowest possible integer of
7392 the specified size will have known values. */
7394 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1)));
7396 if (TREE_CODE (arg1) == INTEGER_CST
7397 && ! TREE_CONSTANT_OVERFLOW (arg1)
7398 && width <= HOST_BITS_PER_WIDE_INT
7399 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
7400 || POINTER_TYPE_P (TREE_TYPE (arg1))))
7402 unsigned HOST_WIDE_INT signed_max;
7403 unsigned HOST_WIDE_INT max, min;
7405 signed_max = ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1;
7407 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
7409 max = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
7415 min = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
7418 if (TREE_INT_CST_HIGH (arg1) == 0
7419 && TREE_INT_CST_LOW (arg1) == max)
7423 return omit_one_operand (type,
7428 return fold (build (EQ_EXPR, type, arg0, arg1));
7431 return omit_one_operand (type,
7436 return fold (build (NE_EXPR, type, arg0, arg1));
7438 /* The GE_EXPR and LT_EXPR cases above are not normally
7439 reached because of previous transformations. */
7444 else if (TREE_INT_CST_HIGH (arg1) == 0
7445 && TREE_INT_CST_LOW (arg1) == max - 1)
7449 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
7450 return fold (build (EQ_EXPR, type, arg0, arg1));
7452 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
7453 return fold (build (NE_EXPR, type, arg0, arg1));
7457 else if (TREE_INT_CST_HIGH (arg1) == (min ? -1 : 0)
7458 && TREE_INT_CST_LOW (arg1) == min)
7462 return omit_one_operand (type,
7467 return fold (build (EQ_EXPR, type, arg0, arg1));
7470 return omit_one_operand (type,
7475 return fold (build (NE_EXPR, type, arg0, arg1));
7480 else if (TREE_INT_CST_HIGH (arg1) == (min ? -1 : 0)
7481 && TREE_INT_CST_LOW (arg1) == min + 1)
7485 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
7486 return fold (build (NE_EXPR, type, arg0, arg1));
7488 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
7489 return fold (build (EQ_EXPR, type, arg0, arg1));
7494 else if (TREE_INT_CST_HIGH (arg1) == 0
7495 && TREE_INT_CST_LOW (arg1) == signed_max
7496 && TYPE_UNSIGNED (TREE_TYPE (arg1))
7497 /* signed_type does not work on pointer types. */
7498 && INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
7500 /* The following case also applies to X < signed_max+1
7501 and X >= signed_max+1 because previous transformations. */
7502 if (code == LE_EXPR || code == GT_EXPR)
7505 st0 = lang_hooks.types.signed_type (TREE_TYPE (arg0));
7506 st1 = lang_hooks.types.signed_type (TREE_TYPE (arg1));
7508 (build (code == LE_EXPR ? GE_EXPR: LT_EXPR,
7509 type, fold_convert (st0, arg0),
7510 fold_convert (st1, integer_zero_node)));
7516 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
7517 a MINUS_EXPR of a constant, we can convert it into a comparison with
7518 a revised constant as long as no overflow occurs. */
7519 if ((code == EQ_EXPR || code == NE_EXPR)
7520 && TREE_CODE (arg1) == INTEGER_CST
7521 && (TREE_CODE (arg0) == PLUS_EXPR
7522 || TREE_CODE (arg0) == MINUS_EXPR)
7523 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7524 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
7525 ? MINUS_EXPR : PLUS_EXPR,
7526 arg1, TREE_OPERAND (arg0, 1), 0))
7527 && ! TREE_CONSTANT_OVERFLOW (tem))
7528 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
7530 /* Similarly for a NEGATE_EXPR. */
7531 else if ((code == EQ_EXPR || code == NE_EXPR)
7532 && TREE_CODE (arg0) == NEGATE_EXPR
7533 && TREE_CODE (arg1) == INTEGER_CST
7534 && 0 != (tem = negate_expr (arg1))
7535 && TREE_CODE (tem) == INTEGER_CST
7536 && ! TREE_CONSTANT_OVERFLOW (tem))
7537 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
7539 /* If we have X - Y == 0, we can convert that to X == Y and similarly
7540 for !=. Don't do this for ordered comparisons due to overflow. */
7541 else if ((code == NE_EXPR || code == EQ_EXPR)
7542 && integer_zerop (arg1) && TREE_CODE (arg0) == MINUS_EXPR)
7543 return fold (build (code, type,
7544 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1)));
7546 /* If we are widening one operand of an integer comparison,
7547 see if the other operand is similarly being widened. Perhaps we
7548 can do the comparison in the narrower type. */
7549 else if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
7550 && TREE_CODE (arg0) == NOP_EXPR
7551 && (tem = get_unwidened (arg0, NULL_TREE)) != arg0
7552 && (code == EQ_EXPR || code == NE_EXPR
7553 || TYPE_UNSIGNED (TREE_TYPE (arg0))
7554 == TYPE_UNSIGNED (TREE_TYPE (tem)))
7555 && (t1 = get_unwidened (arg1, TREE_TYPE (tem))) != 0
7556 && (TREE_TYPE (t1) == TREE_TYPE (tem)
7557 || (TREE_CODE (t1) == INTEGER_CST
7558 && int_fits_type_p (t1, TREE_TYPE (tem)))))
7559 return fold (build (code, type, tem,
7560 fold_convert (TREE_TYPE (tem), t1)));
7562 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
7563 constant, we can simplify it. */
7564 else if (TREE_CODE (arg1) == INTEGER_CST
7565 && (TREE_CODE (arg0) == MIN_EXPR
7566 || TREE_CODE (arg0) == MAX_EXPR)
7567 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
7568 return optimize_minmax_comparison (t);
7570 /* If we are comparing an ABS_EXPR with a constant, we can
7571 convert all the cases into explicit comparisons, but they may
7572 well not be faster than doing the ABS and one comparison.
7573 But ABS (X) <= C is a range comparison, which becomes a subtraction
7574 and a comparison, and is probably faster. */
7575 else if (code == LE_EXPR && TREE_CODE (arg1) == INTEGER_CST
7576 && TREE_CODE (arg0) == ABS_EXPR
7577 && ! TREE_SIDE_EFFECTS (arg0)
7578 && (0 != (tem = negate_expr (arg1)))
7579 && TREE_CODE (tem) == INTEGER_CST
7580 && ! TREE_CONSTANT_OVERFLOW (tem))
7581 return fold (build (TRUTH_ANDIF_EXPR, type,
7582 build (GE_EXPR, type, TREE_OPERAND (arg0, 0), tem),
7583 build (LE_EXPR, type,
7584 TREE_OPERAND (arg0, 0), arg1)));
7586 /* If this is an EQ or NE comparison with zero and ARG0 is
7587 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
7588 two operations, but the latter can be done in one less insn
7589 on machines that have only two-operand insns or on which a
7590 constant cannot be the first operand. */
7591 if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR)
7592 && TREE_CODE (arg0) == BIT_AND_EXPR)
7594 if (TREE_CODE (TREE_OPERAND (arg0, 0)) == LSHIFT_EXPR
7595 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 0), 0)))
7597 fold (build (code, type,
7598 build (BIT_AND_EXPR, TREE_TYPE (arg0),
7600 TREE_TYPE (TREE_OPERAND (arg0, 0)),
7601 TREE_OPERAND (arg0, 1),
7602 TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)),
7603 fold_convert (TREE_TYPE (arg0),
7606 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
7607 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
7609 fold (build (code, type,
7610 build (BIT_AND_EXPR, TREE_TYPE (arg0),
7612 TREE_TYPE (TREE_OPERAND (arg0, 1)),
7613 TREE_OPERAND (arg0, 0),
7614 TREE_OPERAND (TREE_OPERAND (arg0, 1), 1)),
7615 fold_convert (TREE_TYPE (arg0),
7620 /* If this is an NE or EQ comparison of zero against the result of a
7621 signed MOD operation whose second operand is a power of 2, make
7622 the MOD operation unsigned since it is simpler and equivalent. */
7623 if ((code == NE_EXPR || code == EQ_EXPR)
7624 && integer_zerop (arg1)
7625 && !TYPE_UNSIGNED (TREE_TYPE (arg0))
7626 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
7627 || TREE_CODE (arg0) == CEIL_MOD_EXPR
7628 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
7629 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
7630 && integer_pow2p (TREE_OPERAND (arg0, 1)))
7632 tree newtype = lang_hooks.types.unsigned_type (TREE_TYPE (arg0));
7633 tree newmod = build (TREE_CODE (arg0), newtype,
7634 fold_convert (newtype,
7635 TREE_OPERAND (arg0, 0)),
7636 fold_convert (newtype,
7637 TREE_OPERAND (arg0, 1)));
7639 return build (code, type, newmod, fold_convert (newtype, arg1));
7642 /* If this is an NE comparison of zero with an AND of one, remove the
7643 comparison since the AND will give the correct value. */
7644 if (code == NE_EXPR && integer_zerop (arg1)
7645 && TREE_CODE (arg0) == BIT_AND_EXPR
7646 && integer_onep (TREE_OPERAND (arg0, 1)))
7647 return fold_convert (type, arg0);
7649 /* If we have (A & C) == C where C is a power of 2, convert this into
7650 (A & C) != 0. Similarly for NE_EXPR. */
7651 if ((code == EQ_EXPR || code == NE_EXPR)
7652 && TREE_CODE (arg0) == BIT_AND_EXPR
7653 && integer_pow2p (TREE_OPERAND (arg0, 1))
7654 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
7655 return fold (build (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
7656 arg0, integer_zero_node));
7658 /* If we have (A & C) != 0 or (A & C) == 0 and C is a power of
7659 2, then fold the expression into shifts and logical operations. */
7660 tem = fold_single_bit_test (code, arg0, arg1, type);
7664 /* If we have (A & C) == D where D & ~C != 0, convert this into 0.
7665 Similarly for NE_EXPR. */
7666 if ((code == EQ_EXPR || code == NE_EXPR)
7667 && TREE_CODE (arg0) == BIT_AND_EXPR
7668 && TREE_CODE (arg1) == INTEGER_CST
7669 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
7672 = fold (build (BIT_AND_EXPR, TREE_TYPE (arg0),
7673 arg1, build1 (BIT_NOT_EXPR,
7674 TREE_TYPE (TREE_OPERAND (arg0, 1)),
7675 TREE_OPERAND (arg0, 1))));
7676 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
7677 if (integer_nonzerop (dandnotc))
7678 return omit_one_operand (type, rslt, arg0);
7681 /* If we have (A | C) == D where C & ~D != 0, convert this into 0.
7682 Similarly for NE_EXPR. */
7683 if ((code == EQ_EXPR || code == NE_EXPR)
7684 && TREE_CODE (arg0) == BIT_IOR_EXPR
7685 && TREE_CODE (arg1) == INTEGER_CST
7686 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
7689 = fold (build (BIT_AND_EXPR, TREE_TYPE (arg0),
7690 TREE_OPERAND (arg0, 1),
7691 build1 (BIT_NOT_EXPR, TREE_TYPE (arg1), arg1)));
7692 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
7693 if (integer_nonzerop (candnotd))
7694 return omit_one_operand (type, rslt, arg0);
7697 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
7698 and similarly for >= into !=. */
7699 if ((code == LT_EXPR || code == GE_EXPR)
7700 && TYPE_UNSIGNED (TREE_TYPE (arg0))
7701 && TREE_CODE (arg1) == LSHIFT_EXPR
7702 && integer_onep (TREE_OPERAND (arg1, 0)))
7703 return build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
7704 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
7705 TREE_OPERAND (arg1, 1)),
7706 fold_convert (TREE_TYPE (arg0), integer_zero_node));
7708 else if ((code == LT_EXPR || code == GE_EXPR)
7709 && TYPE_UNSIGNED (TREE_TYPE (arg0))
7710 && (TREE_CODE (arg1) == NOP_EXPR
7711 || TREE_CODE (arg1) == CONVERT_EXPR)
7712 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
7713 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
7715 build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
7716 fold_convert (TREE_TYPE (arg0),
7717 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
7718 TREE_OPERAND (TREE_OPERAND (arg1, 0),
7720 fold_convert (TREE_TYPE (arg0), integer_zero_node));
7722 /* Simplify comparison of something with itself. (For IEEE
7723 floating-point, we can only do some of these simplifications.) */
7724 if (operand_equal_p (arg0, arg1, 0))
7729 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
7730 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
7731 return constant_boolean_node (1, type);
7736 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
7737 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
7738 return constant_boolean_node (1, type);
7739 return fold (build (EQ_EXPR, type, arg0, arg1));
7742 /* For NE, we can only do this simplification if integer
7743 or we don't honor IEEE floating point NaNs. */
7744 if (FLOAT_TYPE_P (TREE_TYPE (arg0))
7745 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
7747 /* ... fall through ... */
7750 return constant_boolean_node (0, type);
7756 /* If we are comparing an expression that just has comparisons
7757 of two integer values, arithmetic expressions of those comparisons,
7758 and constants, we can simplify it. There are only three cases
7759 to check: the two values can either be equal, the first can be
7760 greater, or the second can be greater. Fold the expression for
7761 those three values. Since each value must be 0 or 1, we have
7762 eight possibilities, each of which corresponds to the constant 0
7763 or 1 or one of the six possible comparisons.
7765 This handles common cases like (a > b) == 0 but also handles
7766 expressions like ((x > y) - (y > x)) > 0, which supposedly
7767 occur in macroized code. */
7769 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
7771 tree cval1 = 0, cval2 = 0;
7774 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
7775 /* Don't handle degenerate cases here; they should already
7776 have been handled anyway. */
7777 && cval1 != 0 && cval2 != 0
7778 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
7779 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
7780 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
7781 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
7782 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
7783 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
7784 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
7786 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
7787 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
7789 /* We can't just pass T to eval_subst in case cval1 or cval2
7790 was the same as ARG1. */
7793 = fold (build (code, type,
7794 eval_subst (arg0, cval1, maxval, cval2, minval),
7797 = fold (build (code, type,
7798 eval_subst (arg0, cval1, maxval, cval2, maxval),
7801 = fold (build (code, type,
7802 eval_subst (arg0, cval1, minval, cval2, maxval),
7805 /* All three of these results should be 0 or 1. Confirm they
7806 are. Then use those values to select the proper code
7809 if ((integer_zerop (high_result)
7810 || integer_onep (high_result))
7811 && (integer_zerop (equal_result)
7812 || integer_onep (equal_result))
7813 && (integer_zerop (low_result)
7814 || integer_onep (low_result)))
7816 /* Make a 3-bit mask with the high-order bit being the
7817 value for `>', the next for '=', and the low for '<'. */
7818 switch ((integer_onep (high_result) * 4)
7819 + (integer_onep (equal_result) * 2)
7820 + integer_onep (low_result))
7824 return omit_one_operand (type, integer_zero_node, arg0);
7845 return omit_one_operand (type, integer_one_node, arg0);
7848 tem = build (code, type, cval1, cval2);
7850 return save_expr (tem);
7857 /* If this is a comparison of a field, we may be able to simplify it. */
7858 if (((TREE_CODE (arg0) == COMPONENT_REF
7859 && lang_hooks.can_use_bit_fields_p ())
7860 || TREE_CODE (arg0) == BIT_FIELD_REF)
7861 && (code == EQ_EXPR || code == NE_EXPR)
7862 /* Handle the constant case even without -O
7863 to make sure the warnings are given. */
7864 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
7866 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
7871 /* If this is a comparison of complex values and either or both sides
7872 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
7873 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
7874 This may prevent needless evaluations. */
7875 if ((code == EQ_EXPR || code == NE_EXPR)
7876 && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
7877 && (TREE_CODE (arg0) == COMPLEX_EXPR
7878 || TREE_CODE (arg1) == COMPLEX_EXPR
7879 || TREE_CODE (arg0) == COMPLEX_CST
7880 || TREE_CODE (arg1) == COMPLEX_CST))
7882 tree subtype = TREE_TYPE (TREE_TYPE (arg0));
7883 tree real0, imag0, real1, imag1;
7885 arg0 = save_expr (arg0);
7886 arg1 = save_expr (arg1);
7887 real0 = fold (build1 (REALPART_EXPR, subtype, arg0));
7888 imag0 = fold (build1 (IMAGPART_EXPR, subtype, arg0));
7889 real1 = fold (build1 (REALPART_EXPR, subtype, arg1));
7890 imag1 = fold (build1 (IMAGPART_EXPR, subtype, arg1));
7892 return fold (build ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR
7895 fold (build (code, type, real0, real1)),
7896 fold (build (code, type, imag0, imag1))));
7899 /* Optimize comparisons of strlen vs zero to a compare of the
7900 first character of the string vs zero. To wit,
7901 strlen(ptr) == 0 => *ptr == 0
7902 strlen(ptr) != 0 => *ptr != 0
7903 Other cases should reduce to one of these two (or a constant)
7904 due to the return value of strlen being unsigned. */
7905 if ((code == EQ_EXPR || code == NE_EXPR)
7906 && integer_zerop (arg1)
7907 && TREE_CODE (arg0) == CALL_EXPR)
7909 tree fndecl = get_callee_fndecl (arg0);
7913 && DECL_BUILT_IN (fndecl)
7914 && DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_MD
7915 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
7916 && (arglist = TREE_OPERAND (arg0, 1))
7917 && TREE_CODE (TREE_TYPE (TREE_VALUE (arglist))) == POINTER_TYPE
7918 && ! TREE_CHAIN (arglist))
7919 return fold (build (code, type,
7920 build1 (INDIRECT_REF, char_type_node,
7921 TREE_VALUE(arglist)),
7922 integer_zero_node));
7925 /* Both ARG0 and ARG1 are known to be constants at this point. */
7926 t1 = fold_relational_const (code, type, arg0, arg1);
7927 return (t1 == NULL_TREE ? t : t1);
7930 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
7931 so all simple results must be passed through pedantic_non_lvalue. */
7932 if (TREE_CODE (arg0) == INTEGER_CST)
7934 tem = TREE_OPERAND (t, (integer_zerop (arg0) ? 2 : 1));
7935 /* Only optimize constant conditions when the selected branch
7936 has the same type as the COND_EXPR. This avoids optimizing
7937 away "c ? x : throw", where the throw has a void type. */
7938 if (! VOID_TYPE_P (TREE_TYPE (tem))
7939 || VOID_TYPE_P (type))
7940 return pedantic_non_lvalue (tem);
7943 if (operand_equal_p (arg1, TREE_OPERAND (t, 2), 0))
7944 return pedantic_omit_one_operand (type, arg1, arg0);
7946 /* If we have A op B ? A : C, we may be able to convert this to a
7947 simpler expression, depending on the operation and the values
7948 of B and C. Signed zeros prevent all of these transformations,
7949 for reasons given above each one. */
7951 if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
7952 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
7953 arg1, TREE_OPERAND (arg0, 1))
7954 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
7956 tree arg2 = TREE_OPERAND (t, 2);
7957 enum tree_code comp_code = TREE_CODE (arg0);
7961 /* If we have A op 0 ? A : -A, consider applying the following
7964 A == 0? A : -A same as -A
7965 A != 0? A : -A same as A
7966 A >= 0? A : -A same as abs (A)
7967 A > 0? A : -A same as abs (A)
7968 A <= 0? A : -A same as -abs (A)
7969 A < 0? A : -A same as -abs (A)
7971 None of these transformations work for modes with signed
7972 zeros. If A is +/-0, the first two transformations will
7973 change the sign of the result (from +0 to -0, or vice
7974 versa). The last four will fix the sign of the result,
7975 even though the original expressions could be positive or
7976 negative, depending on the sign of A.
7978 Note that all these transformations are correct if A is
7979 NaN, since the two alternatives (A and -A) are also NaNs. */
7980 if ((FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 1)))
7981 ? real_zerop (TREE_OPERAND (arg0, 1))
7982 : integer_zerop (TREE_OPERAND (arg0, 1)))
7983 && TREE_CODE (arg2) == NEGATE_EXPR
7984 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
7988 tem = fold_convert (TREE_TYPE (TREE_OPERAND (t, 1)), arg1);
7989 tem = fold_convert (type, negate_expr (tem));
7990 return pedantic_non_lvalue (tem);
7992 return pedantic_non_lvalue (fold_convert (type, arg1));
7995 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
7996 arg1 = fold_convert (lang_hooks.types.signed_type
7997 (TREE_TYPE (arg1)), arg1);
7998 arg1 = fold (build1 (ABS_EXPR, TREE_TYPE (arg1), arg1));
7999 return pedantic_non_lvalue (fold_convert (type, arg1));
8002 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
8003 arg1 = fold_convert (lang_hooks.types.signed_type
8004 (TREE_TYPE (arg1)), arg1);
8005 arg1 = fold (build1 (ABS_EXPR, TREE_TYPE (arg1), arg1));
8006 arg1 = negate_expr (fold_convert (type, arg1));
8007 return pedantic_non_lvalue (arg1);
8012 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
8013 A == 0 ? A : 0 is always 0 unless A is -0. Note that
8014 both transformations are correct when A is NaN: A != 0
8015 is then true, and A == 0 is false. */
8017 if (integer_zerop (TREE_OPERAND (arg0, 1)) && integer_zerop (arg2))
8019 if (comp_code == NE_EXPR)
8020 return pedantic_non_lvalue (fold_convert (type, arg1));
8021 else if (comp_code == EQ_EXPR)
8022 return pedantic_non_lvalue (fold_convert (type, integer_zero_node));
8025 /* Try some transformations of A op B ? A : B.
8027 A == B? A : B same as B
8028 A != B? A : B same as A
8029 A >= B? A : B same as max (A, B)
8030 A > B? A : B same as max (B, A)
8031 A <= B? A : B same as min (A, B)
8032 A < B? A : B same as min (B, A)
8034 As above, these transformations don't work in the presence
8035 of signed zeros. For example, if A and B are zeros of
8036 opposite sign, the first two transformations will change
8037 the sign of the result. In the last four, the original
8038 expressions give different results for (A=+0, B=-0) and
8039 (A=-0, B=+0), but the transformed expressions do not.
8041 The first two transformations are correct if either A or B
8042 is a NaN. In the first transformation, the condition will
8043 be false, and B will indeed be chosen. In the case of the
8044 second transformation, the condition A != B will be true,
8045 and A will be chosen.
8047 The conversions to max() and min() are not correct if B is
8048 a number and A is not. The conditions in the original
8049 expressions will be false, so all four give B. The min()
8050 and max() versions would give a NaN instead. */
8051 if (operand_equal_for_comparison_p (TREE_OPERAND (arg0, 1),
8052 arg2, TREE_OPERAND (arg0, 0)))
8054 tree comp_op0 = TREE_OPERAND (arg0, 0);
8055 tree comp_op1 = TREE_OPERAND (arg0, 1);
8056 tree comp_type = TREE_TYPE (comp_op0);
8058 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
8059 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
8069 return pedantic_non_lvalue (fold_convert (type, arg2));
8071 return pedantic_non_lvalue (fold_convert (type, arg1));
8074 /* In C++ a ?: expression can be an lvalue, so put the
8075 operand which will be used if they are equal first
8076 so that we can convert this back to the
8077 corresponding COND_EXPR. */
8078 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
8079 return pedantic_non_lvalue (fold_convert
8080 (type, fold (build (MIN_EXPR, comp_type,
8081 (comp_code == LE_EXPR
8082 ? comp_op0 : comp_op1),
8083 (comp_code == LE_EXPR
8084 ? comp_op1 : comp_op0)))));
8088 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
8089 return pedantic_non_lvalue (fold_convert
8090 (type, fold (build (MAX_EXPR, comp_type,
8091 (comp_code == GE_EXPR
8092 ? comp_op0 : comp_op1),
8093 (comp_code == GE_EXPR
8094 ? comp_op1 : comp_op0)))));
8101 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
8102 we might still be able to simplify this. For example,
8103 if C1 is one less or one more than C2, this might have started
8104 out as a MIN or MAX and been transformed by this function.
8105 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
8107 if (INTEGRAL_TYPE_P (type)
8108 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8109 && TREE_CODE (arg2) == INTEGER_CST)
8113 /* We can replace A with C1 in this case. */
8114 arg1 = fold_convert (type, TREE_OPERAND (arg0, 1));
8115 return fold (build (code, type, TREE_OPERAND (t, 0), arg1,
8116 TREE_OPERAND (t, 2)));
8119 /* If C1 is C2 + 1, this is min(A, C2). */
8120 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
8121 && operand_equal_p (TREE_OPERAND (arg0, 1),
8122 const_binop (PLUS_EXPR, arg2,
8123 integer_one_node, 0), 1))
8124 return pedantic_non_lvalue
8125 (fold (build (MIN_EXPR, type, arg1, arg2)));
8129 /* If C1 is C2 - 1, this is min(A, C2). */
8130 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
8131 && operand_equal_p (TREE_OPERAND (arg0, 1),
8132 const_binop (MINUS_EXPR, arg2,
8133 integer_one_node, 0), 1))
8134 return pedantic_non_lvalue
8135 (fold (build (MIN_EXPR, type, arg1, arg2)));
8139 /* If C1 is C2 - 1, this is max(A, C2). */
8140 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
8141 && operand_equal_p (TREE_OPERAND (arg0, 1),
8142 const_binop (MINUS_EXPR, arg2,
8143 integer_one_node, 0), 1))
8144 return pedantic_non_lvalue
8145 (fold (build (MAX_EXPR, type, arg1, arg2)));
8149 /* If C1 is C2 + 1, this is max(A, C2). */
8150 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
8151 && operand_equal_p (TREE_OPERAND (arg0, 1),
8152 const_binop (PLUS_EXPR, arg2,
8153 integer_one_node, 0), 1))
8154 return pedantic_non_lvalue
8155 (fold (build (MAX_EXPR, type, arg1, arg2)));
8164 /* If the second operand is simpler than the third, swap them
8165 since that produces better jump optimization results. */
8166 if (tree_swap_operands_p (TREE_OPERAND (t, 1),
8167 TREE_OPERAND (t, 2), false))
8169 /* See if this can be inverted. If it can't, possibly because
8170 it was a floating-point inequality comparison, don't do
8172 tem = invert_truthvalue (arg0);
8174 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
8175 return fold (build (code, type, tem,
8176 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1)));
8179 /* Convert A ? 1 : 0 to simply A. */
8180 if (integer_onep (TREE_OPERAND (t, 1))
8181 && integer_zerop (TREE_OPERAND (t, 2))
8182 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
8183 call to fold will try to move the conversion inside
8184 a COND, which will recurse. In that case, the COND_EXPR
8185 is probably the best choice, so leave it alone. */
8186 && type == TREE_TYPE (arg0))
8187 return pedantic_non_lvalue (arg0);
8189 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
8190 over COND_EXPR in cases such as floating point comparisons. */
8191 if (integer_zerop (TREE_OPERAND (t, 1))
8192 && integer_onep (TREE_OPERAND (t, 2))
8193 && truth_value_p (TREE_CODE (arg0)))
8194 return pedantic_non_lvalue (fold_convert (type,
8195 invert_truthvalue (arg0)));
8197 /* Look for expressions of the form A & 2 ? 2 : 0. The result of this
8198 operation is simply A & 2. */
8200 if (integer_zerop (TREE_OPERAND (t, 2))
8201 && TREE_CODE (arg0) == NE_EXPR
8202 && integer_zerop (TREE_OPERAND (arg0, 1))
8203 && integer_pow2p (arg1)
8204 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
8205 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
8207 return pedantic_non_lvalue (fold_convert (type,
8208 TREE_OPERAND (arg0, 0)));
8210 /* Convert A ? B : 0 into A && B if A and B are truth values. */
8211 if (integer_zerop (TREE_OPERAND (t, 2))
8212 && truth_value_p (TREE_CODE (arg0))
8213 && truth_value_p (TREE_CODE (arg1)))
8214 return pedantic_non_lvalue (fold (build (TRUTH_ANDIF_EXPR, type,
8217 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
8218 if (integer_onep (TREE_OPERAND (t, 2))
8219 && truth_value_p (TREE_CODE (arg0))
8220 && truth_value_p (TREE_CODE (arg1)))
8222 /* Only perform transformation if ARG0 is easily inverted. */
8223 tem = invert_truthvalue (arg0);
8224 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
8225 return pedantic_non_lvalue (fold (build (TRUTH_ORIF_EXPR, type,
8232 /* When pedantic, a compound expression can be neither an lvalue
8233 nor an integer constant expression. */
8234 if (TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
8236 /* Don't let (0, 0) be null pointer constant. */
8237 tem = integer_zerop (arg1) ? build1 (NOP_EXPR, type, arg1)
8238 : fold_convert (type, arg1);
8239 return pedantic_non_lvalue (tem);
8243 return build_complex (type, arg0, arg1);
8247 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8249 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
8250 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
8251 TREE_OPERAND (arg0, 1));
8252 else if (TREE_CODE (arg0) == COMPLEX_CST)
8253 return TREE_REALPART (arg0);
8254 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8255 return fold (build (TREE_CODE (arg0), type,
8256 fold (build1 (REALPART_EXPR, type,
8257 TREE_OPERAND (arg0, 0))),
8258 fold (build1 (REALPART_EXPR,
8259 type, TREE_OPERAND (arg0, 1)))));
8263 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8264 return fold_convert (type, integer_zero_node);
8265 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
8266 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
8267 TREE_OPERAND (arg0, 0));
8268 else if (TREE_CODE (arg0) == COMPLEX_CST)
8269 return TREE_IMAGPART (arg0);
8270 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8271 return fold (build (TREE_CODE (arg0), type,
8272 fold (build1 (IMAGPART_EXPR, type,
8273 TREE_OPERAND (arg0, 0))),
8274 fold (build1 (IMAGPART_EXPR, type,
8275 TREE_OPERAND (arg0, 1)))));
8278 /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
8280 case CLEANUP_POINT_EXPR:
8281 if (! has_cleanups (arg0))
8282 return TREE_OPERAND (t, 0);
8285 enum tree_code code0 = TREE_CODE (arg0);
8286 int kind0 = TREE_CODE_CLASS (code0);
8287 tree arg00 = TREE_OPERAND (arg0, 0);
8290 if (kind0 == '1' || code0 == TRUTH_NOT_EXPR)
8291 return fold (build1 (code0, type,
8292 fold (build1 (CLEANUP_POINT_EXPR,
8293 TREE_TYPE (arg00), arg00))));
8295 if (kind0 == '<' || kind0 == '2'
8296 || code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR
8297 || code0 == TRUTH_AND_EXPR || code0 == TRUTH_OR_EXPR
8298 || code0 == TRUTH_XOR_EXPR)
8300 arg01 = TREE_OPERAND (arg0, 1);
8302 if (TREE_CONSTANT (arg00)
8303 || ((code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR)
8304 && ! has_cleanups (arg00)))
8305 return fold (build (code0, type, arg00,
8306 fold (build1 (CLEANUP_POINT_EXPR,
8307 TREE_TYPE (arg01), arg01))));
8309 if (TREE_CONSTANT (arg01))
8310 return fold (build (code0, type,
8311 fold (build1 (CLEANUP_POINT_EXPR,
8312 TREE_TYPE (arg00), arg00)),
8320 /* Check for a built-in function. */
8321 if (TREE_CODE (TREE_OPERAND (t, 0)) == ADDR_EXPR
8322 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0))
8324 && DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (t, 0), 0)))
8326 tree tmp = fold_builtin (t);
8334 } /* switch (code) */
8337 #ifdef ENABLE_FOLD_CHECKING
8340 static void fold_checksum_tree (tree, struct md5_ctx *, htab_t);
8341 static void fold_check_failed (tree, tree);
8342 void print_fold_checksum (tree);
8344 /* When --enable-checking=fold, compute a digest of expr before
8345 and after actual fold call to see if fold did not accidentally
8346 change original expr. */
8353 unsigned char checksum_before[16], checksum_after[16];
8356 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
8357 md5_init_ctx (&ctx);
8358 fold_checksum_tree (expr, &ctx, ht);
8359 md5_finish_ctx (&ctx, checksum_before);
8362 ret = fold_1 (expr);
8364 md5_init_ctx (&ctx);
8365 fold_checksum_tree (expr, &ctx, ht);
8366 md5_finish_ctx (&ctx, checksum_after);
8369 if (memcmp (checksum_before, checksum_after, 16))
8370 fold_check_failed (expr, ret);
8376 print_fold_checksum (tree expr)
8379 unsigned char checksum[16], cnt;
8382 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
8383 md5_init_ctx (&ctx);
8384 fold_checksum_tree (expr, &ctx, ht);
8385 md5_finish_ctx (&ctx, checksum);
8387 for (cnt = 0; cnt < 16; ++cnt)
8388 fprintf (stderr, "%02x", checksum[cnt]);
8389 putc ('\n', stderr);
8393 fold_check_failed (tree expr ATTRIBUTE_UNUSED, tree ret ATTRIBUTE_UNUSED)
8395 internal_error ("fold check: original tree changed by fold");
8399 fold_checksum_tree (tree expr, struct md5_ctx *ctx, htab_t ht)
8402 enum tree_code code;
8403 char buf[sizeof (struct tree_decl)];
8406 if (sizeof (struct tree_exp) + 5 * sizeof (tree)
8407 > sizeof (struct tree_decl)
8408 || sizeof (struct tree_type) > sizeof (struct tree_decl))
8412 slot = htab_find_slot (ht, expr, INSERT);
8416 code = TREE_CODE (expr);
8417 if (code == SAVE_EXPR && SAVE_EXPR_NOPLACEHOLDER (expr))
8419 /* Allow SAVE_EXPR_NOPLACEHOLDER flag to be modified. */
8420 memcpy (buf, expr, tree_size (expr));
8422 SAVE_EXPR_NOPLACEHOLDER (expr) = 0;
8424 else if (TREE_CODE_CLASS (code) == 'd' && DECL_ASSEMBLER_NAME_SET_P (expr))
8426 /* Allow DECL_ASSEMBLER_NAME to be modified. */
8427 memcpy (buf, expr, tree_size (expr));
8429 SET_DECL_ASSEMBLER_NAME (expr, NULL);
8431 else if (TREE_CODE_CLASS (code) == 't'
8432 && (TYPE_POINTER_TO (expr) || TYPE_REFERENCE_TO (expr)))
8434 /* Allow TYPE_POINTER_TO and TYPE_REFERENCE_TO to be modified. */
8435 memcpy (buf, expr, tree_size (expr));
8437 TYPE_POINTER_TO (expr) = NULL;
8438 TYPE_REFERENCE_TO (expr) = NULL;
8440 md5_process_bytes (expr, tree_size (expr), ctx);
8441 fold_checksum_tree (TREE_TYPE (expr), ctx, ht);
8442 if (TREE_CODE_CLASS (code) != 't' && TREE_CODE_CLASS (code) != 'd')
8443 fold_checksum_tree (TREE_CHAIN (expr), ctx, ht);
8444 len = TREE_CODE_LENGTH (code);
8445 switch (TREE_CODE_CLASS (code))
8451 md5_process_bytes (TREE_STRING_POINTER (expr),
8452 TREE_STRING_LENGTH (expr), ctx);
8455 fold_checksum_tree (TREE_REALPART (expr), ctx, ht);
8456 fold_checksum_tree (TREE_IMAGPART (expr), ctx, ht);
8459 fold_checksum_tree (TREE_VECTOR_CST_ELTS (expr), ctx, ht);
8469 fold_checksum_tree (TREE_PURPOSE (expr), ctx, ht);
8470 fold_checksum_tree (TREE_VALUE (expr), ctx, ht);
8473 for (i = 0; i < TREE_VEC_LENGTH (expr); ++i)
8474 fold_checksum_tree (TREE_VEC_ELT (expr, i), ctx, ht);
8483 case SAVE_EXPR: len = 2; break;
8484 case GOTO_SUBROUTINE_EXPR: len = 0; break;
8485 case RTL_EXPR: len = 0; break;
8486 case WITH_CLEANUP_EXPR: len = 2; break;
8495 for (i = 0; i < len; ++i)
8496 fold_checksum_tree (TREE_OPERAND (expr, i), ctx, ht);
8499 fold_checksum_tree (DECL_SIZE (expr), ctx, ht);
8500 fold_checksum_tree (DECL_SIZE_UNIT (expr), ctx, ht);
8501 fold_checksum_tree (DECL_NAME (expr), ctx, ht);
8502 fold_checksum_tree (DECL_CONTEXT (expr), ctx, ht);
8503 fold_checksum_tree (DECL_ARGUMENTS (expr), ctx, ht);
8504 fold_checksum_tree (DECL_RESULT_FLD (expr), ctx, ht);
8505 fold_checksum_tree (DECL_INITIAL (expr), ctx, ht);
8506 fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr), ctx, ht);
8507 fold_checksum_tree (DECL_SECTION_NAME (expr), ctx, ht);
8508 fold_checksum_tree (DECL_ATTRIBUTES (expr), ctx, ht);
8509 fold_checksum_tree (DECL_VINDEX (expr), ctx, ht);
8512 fold_checksum_tree (TYPE_VALUES (expr), ctx, ht);
8513 fold_checksum_tree (TYPE_SIZE (expr), ctx, ht);
8514 fold_checksum_tree (TYPE_SIZE_UNIT (expr), ctx, ht);
8515 fold_checksum_tree (TYPE_ATTRIBUTES (expr), ctx, ht);
8516 fold_checksum_tree (TYPE_NAME (expr), ctx, ht);
8517 fold_checksum_tree (TYPE_MIN_VALUE (expr), ctx, ht);
8518 fold_checksum_tree (TYPE_MAX_VALUE (expr), ctx, ht);
8519 fold_checksum_tree (TYPE_MAIN_VARIANT (expr), ctx, ht);
8520 fold_checksum_tree (TYPE_BINFO (expr), ctx, ht);
8521 fold_checksum_tree (TYPE_CONTEXT (expr), ctx, ht);
8530 /* Perform constant folding and related simplification of initializer
8531 expression EXPR. This behaves identically to "fold" but ignores
8532 potential run-time traps and exceptions that fold must preserve. */
8535 fold_initializer (tree expr)
8537 int saved_signaling_nans = flag_signaling_nans;
8538 int saved_trapping_math = flag_trapping_math;
8539 int saved_trapv = flag_trapv;
8542 flag_signaling_nans = 0;
8543 flag_trapping_math = 0;
8546 result = fold (expr);
8548 flag_signaling_nans = saved_signaling_nans;
8549 flag_trapping_math = saved_trapping_math;
8550 flag_trapv = saved_trapv;
8555 /* Determine if first argument is a multiple of second argument. Return 0 if
8556 it is not, or we cannot easily determined it to be.
8558 An example of the sort of thing we care about (at this point; this routine
8559 could surely be made more general, and expanded to do what the *_DIV_EXPR's
8560 fold cases do now) is discovering that
8562 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
8568 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
8570 This code also handles discovering that
8572 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
8574 is a multiple of 8 so we don't have to worry about dealing with a
8577 Note that we *look* inside a SAVE_EXPR only to determine how it was
8578 calculated; it is not safe for fold to do much of anything else with the
8579 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
8580 at run time. For example, the latter example above *cannot* be implemented
8581 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
8582 evaluation time of the original SAVE_EXPR is not necessarily the same at
8583 the time the new expression is evaluated. The only optimization of this
8584 sort that would be valid is changing
8586 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
8590 SAVE_EXPR (I) * SAVE_EXPR (J)
8592 (where the same SAVE_EXPR (J) is used in the original and the
8593 transformed version). */
8596 multiple_of_p (tree type, tree top, tree bottom)
8598 if (operand_equal_p (top, bottom, 0))
8601 if (TREE_CODE (type) != INTEGER_TYPE)
8604 switch (TREE_CODE (top))
8607 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
8608 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
8612 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
8613 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
8616 if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
8620 op1 = TREE_OPERAND (top, 1);
8621 /* const_binop may not detect overflow correctly,
8622 so check for it explicitly here. */
8623 if (TYPE_PRECISION (TREE_TYPE (size_one_node))
8624 > TREE_INT_CST_LOW (op1)
8625 && TREE_INT_CST_HIGH (op1) == 0
8626 && 0 != (t1 = fold_convert (type,
8627 const_binop (LSHIFT_EXPR,
8630 && ! TREE_OVERFLOW (t1))
8631 return multiple_of_p (type, t1, bottom);
8636 /* Can't handle conversions from non-integral or wider integral type. */
8637 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
8638 || (TYPE_PRECISION (type)
8639 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
8642 /* .. fall through ... */
8645 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
8648 if (TREE_CODE (bottom) != INTEGER_CST
8649 || (TYPE_UNSIGNED (type)
8650 && (tree_int_cst_sgn (top) < 0
8651 || tree_int_cst_sgn (bottom) < 0)))
8653 return integer_zerop (const_binop (TRUNC_MOD_EXPR,
8661 /* Return true if `t' is known to be non-negative. */
8664 tree_expr_nonnegative_p (tree t)
8666 switch (TREE_CODE (t))
8672 return tree_int_cst_sgn (t) >= 0;
8675 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
8678 if (FLOAT_TYPE_P (TREE_TYPE (t)))
8679 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8680 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8682 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
8683 both unsigned and at least 2 bits shorter than the result. */
8684 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
8685 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
8686 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
8688 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
8689 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
8690 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
8691 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
8693 unsigned int prec = MAX (TYPE_PRECISION (inner1),
8694 TYPE_PRECISION (inner2)) + 1;
8695 return prec < TYPE_PRECISION (TREE_TYPE (t));
8701 if (FLOAT_TYPE_P (TREE_TYPE (t)))
8703 /* x * x for floating point x is always non-negative. */
8704 if (operand_equal_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1), 0))
8706 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8707 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8710 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
8711 both unsigned and their total bits is shorter than the result. */
8712 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
8713 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
8714 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
8716 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
8717 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
8718 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
8719 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
8720 return TYPE_PRECISION (inner1) + TYPE_PRECISION (inner2)
8721 < TYPE_PRECISION (TREE_TYPE (t));
8725 case TRUNC_DIV_EXPR:
8727 case FLOOR_DIV_EXPR:
8728 case ROUND_DIV_EXPR:
8729 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8730 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8732 case TRUNC_MOD_EXPR:
8734 case FLOOR_MOD_EXPR:
8735 case ROUND_MOD_EXPR:
8736 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8739 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8740 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8743 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
8744 || tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8747 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8748 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8752 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
8753 tree outer_type = TREE_TYPE (t);
8755 if (TREE_CODE (outer_type) == REAL_TYPE)
8757 if (TREE_CODE (inner_type) == REAL_TYPE)
8758 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8759 if (TREE_CODE (inner_type) == INTEGER_TYPE)
8761 if (TYPE_UNSIGNED (inner_type))
8763 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8766 else if (TREE_CODE (outer_type) == INTEGER_TYPE)
8768 if (TREE_CODE (inner_type) == REAL_TYPE)
8769 return tree_expr_nonnegative_p (TREE_OPERAND (t,0));
8770 if (TREE_CODE (inner_type) == INTEGER_TYPE)
8771 return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
8772 && TYPE_UNSIGNED (inner_type);
8778 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
8779 && tree_expr_nonnegative_p (TREE_OPERAND (t, 2));
8781 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8783 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8784 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8786 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8787 || tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8789 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8791 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8793 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8794 case NON_LVALUE_EXPR:
8795 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8797 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8799 return rtl_expr_nonnegative_p (RTL_EXPR_RTL (t));
8803 tree fndecl = get_callee_fndecl (t);
8804 tree arglist = TREE_OPERAND (t, 1);
8806 && DECL_BUILT_IN (fndecl)
8807 && DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_MD)
8808 switch (DECL_FUNCTION_CODE (fndecl))
8810 #define CASE_BUILTIN_F(BUILT_IN_FN) \
8811 case BUILT_IN_FN: case BUILT_IN_FN##F: case BUILT_IN_FN##L:
8812 #define CASE_BUILTIN_I(BUILT_IN_FN) \
8813 case BUILT_IN_FN: case BUILT_IN_FN##L: case BUILT_IN_FN##LL:
8815 CASE_BUILTIN_F (BUILT_IN_ACOS)
8816 CASE_BUILTIN_F (BUILT_IN_ACOSH)
8817 CASE_BUILTIN_F (BUILT_IN_CABS)
8818 CASE_BUILTIN_F (BUILT_IN_COSH)
8819 CASE_BUILTIN_F (BUILT_IN_ERFC)
8820 CASE_BUILTIN_F (BUILT_IN_EXP)
8821 CASE_BUILTIN_F (BUILT_IN_EXP10)
8822 CASE_BUILTIN_F (BUILT_IN_EXP2)
8823 CASE_BUILTIN_F (BUILT_IN_FABS)
8824 CASE_BUILTIN_F (BUILT_IN_FDIM)
8825 CASE_BUILTIN_F (BUILT_IN_FREXP)
8826 CASE_BUILTIN_F (BUILT_IN_HYPOT)
8827 CASE_BUILTIN_F (BUILT_IN_POW10)
8828 CASE_BUILTIN_F (BUILT_IN_SQRT)
8829 CASE_BUILTIN_I (BUILT_IN_FFS)
8830 CASE_BUILTIN_I (BUILT_IN_PARITY)
8831 CASE_BUILTIN_I (BUILT_IN_POPCOUNT)
8835 CASE_BUILTIN_F (BUILT_IN_ASINH)
8836 CASE_BUILTIN_F (BUILT_IN_ATAN)
8837 CASE_BUILTIN_F (BUILT_IN_ATANH)
8838 CASE_BUILTIN_F (BUILT_IN_CBRT)
8839 CASE_BUILTIN_F (BUILT_IN_CEIL)
8840 CASE_BUILTIN_F (BUILT_IN_ERF)
8841 CASE_BUILTIN_F (BUILT_IN_EXPM1)
8842 CASE_BUILTIN_F (BUILT_IN_FLOOR)
8843 CASE_BUILTIN_F (BUILT_IN_FMOD)
8844 CASE_BUILTIN_F (BUILT_IN_LDEXP)
8845 CASE_BUILTIN_F (BUILT_IN_LLRINT)
8846 CASE_BUILTIN_F (BUILT_IN_LLROUND)
8847 CASE_BUILTIN_F (BUILT_IN_LRINT)
8848 CASE_BUILTIN_F (BUILT_IN_LROUND)
8849 CASE_BUILTIN_F (BUILT_IN_MODF)
8850 CASE_BUILTIN_F (BUILT_IN_NEARBYINT)
8851 CASE_BUILTIN_F (BUILT_IN_POW)
8852 CASE_BUILTIN_F (BUILT_IN_RINT)
8853 CASE_BUILTIN_F (BUILT_IN_ROUND)
8854 CASE_BUILTIN_F (BUILT_IN_SIGNBIT)
8855 CASE_BUILTIN_F (BUILT_IN_SINH)
8856 CASE_BUILTIN_F (BUILT_IN_TANH)
8857 CASE_BUILTIN_F (BUILT_IN_TRUNC)
8858 /* True if the 1st argument is nonnegative. */
8859 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
8861 CASE_BUILTIN_F(BUILT_IN_FMAX)
8862 /* True if the 1st OR 2nd arguments are nonnegative. */
8863 return tree_expr_nonnegative_p (TREE_VALUE (arglist))
8864 || tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist)));
8866 CASE_BUILTIN_F(BUILT_IN_FMIN)
8867 /* True if the 1st AND 2nd arguments are nonnegative. */
8868 return tree_expr_nonnegative_p (TREE_VALUE (arglist))
8869 && tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist)));
8871 CASE_BUILTIN_F(BUILT_IN_COPYSIGN)
8872 /* True if the 2nd argument is nonnegative. */
8873 return tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist)));
8877 #undef CASE_BUILTIN_F
8878 #undef CASE_BUILTIN_I
8882 /* ... fall through ... */
8885 if (truth_value_p (TREE_CODE (t)))
8886 /* Truth values evaluate to 0 or 1, which is nonnegative. */
8890 /* We don't know sign of `t', so be conservative and return false. */
8894 /* Return true when T is an address and is known to be nonzero.
8895 For floating point we further ensure that T is not denormal.
8896 Similar logic is present in nonzero_address in rtlanal.h */
8899 tree_expr_nonzero_p (tree t)
8901 tree type = TREE_TYPE (t);
8903 /* Doing something usefull for floating point would need more work. */
8904 if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
8907 switch (TREE_CODE (t))
8910 if (!TYPE_UNSIGNED (type) && !flag_wrapv)
8911 return tree_expr_nonzero_p (TREE_OPERAND (t, 0));
8914 return !integer_zerop (t);
8917 if (!TYPE_UNSIGNED (type) && !flag_wrapv)
8919 /* With the presence of negative values it is hard
8920 to say something. */
8921 if (!tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8922 || !tree_expr_nonnegative_p (TREE_OPERAND (t, 1)))
8924 /* One of operands must be positive and the other non-negative. */
8925 return (tree_expr_nonzero_p (TREE_OPERAND (t, 0))
8926 || tree_expr_nonzero_p (TREE_OPERAND (t, 1)));
8931 if (!TYPE_UNSIGNED (type) && !flag_wrapv)
8933 return (tree_expr_nonzero_p (TREE_OPERAND (t, 0))
8934 && tree_expr_nonzero_p (TREE_OPERAND (t, 1)));
8940 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
8941 tree outer_type = TREE_TYPE (t);
8943 return (TYPE_PRECISION (inner_type) >= TYPE_PRECISION (outer_type)
8944 && tree_expr_nonzero_p (TREE_OPERAND (t, 0)));
8949 /* Weak declarations may link to NULL. */
8950 if (DECL_P (TREE_OPERAND (t, 0)))
8951 return !DECL_WEAK (TREE_OPERAND (t, 0));
8952 /* Constants and all other cases are never weak. */
8956 return (tree_expr_nonzero_p (TREE_OPERAND (t, 1))
8957 && tree_expr_nonzero_p (TREE_OPERAND (t, 2)));
8960 return (tree_expr_nonzero_p (TREE_OPERAND (t, 0))
8961 && tree_expr_nonzero_p (TREE_OPERAND (t, 1)));
8964 if (tree_expr_nonzero_p (TREE_OPERAND (t, 0)))
8966 /* When both operands are nonzero, then MAX must be too. */
8967 if (tree_expr_nonzero_p (TREE_OPERAND (t, 1)))
8970 /* MAX where operand 0 is positive is positive. */
8971 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8973 /* MAX where operand 1 is positive is positive. */
8974 else if (tree_expr_nonzero_p (TREE_OPERAND (t, 1))
8975 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1)))
8982 return tree_expr_nonzero_p (TREE_OPERAND (t, 1));
8985 case NON_LVALUE_EXPR:
8986 return tree_expr_nonzero_p (TREE_OPERAND (t, 0));
8989 return tree_expr_nonzero_p (TREE_OPERAND (t, 1))
8990 || tree_expr_nonzero_p (TREE_OPERAND (t, 0));
8998 /* Return true if `r' is known to be non-negative.
8999 Only handles constants at the moment. */
9002 rtl_expr_nonnegative_p (rtx r)
9004 switch (GET_CODE (r))
9007 return INTVAL (r) >= 0;
9010 if (GET_MODE (r) == VOIDmode)
9011 return CONST_DOUBLE_HIGH (r) >= 0;
9019 units = CONST_VECTOR_NUNITS (r);
9021 for (i = 0; i < units; ++i)
9023 elt = CONST_VECTOR_ELT (r, i);
9024 if (!rtl_expr_nonnegative_p (elt))
9033 /* These are always nonnegative. */
9041 /* Return the tree for neg (ARG0) when ARG0 is known to be either
9042 an integer constant or real constant.
9044 TYPE is the type of the result. */
9047 fold_negate_const (tree arg0, tree type)
9051 if (TREE_CODE (arg0) == INTEGER_CST)
9053 unsigned HOST_WIDE_INT low;
9055 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
9056 TREE_INT_CST_HIGH (arg0),
9058 t = build_int_2 (low, high);
9059 TREE_TYPE (t) = type;
9061 = (TREE_OVERFLOW (arg0)
9062 | force_fit_type (t, overflow && !TYPE_UNSIGNED (type)));
9063 TREE_CONSTANT_OVERFLOW (t)
9064 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
9066 else if (TREE_CODE (arg0) == REAL_CST)
9067 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
9068 #ifdef ENABLE_CHECKING
9076 /* Return the tree for abs (ARG0) when ARG0 is known to be either
9077 an integer constant or real constant.
9079 TYPE is the type of the result. */
9082 fold_abs_const (tree arg0, tree type)
9086 if (TREE_CODE (arg0) == INTEGER_CST)
9088 /* If the value is unsigned, then the absolute value is
9089 the same as the ordinary value. */
9090 if (TYPE_UNSIGNED (type))
9092 /* Similarly, if the value is non-negative. */
9093 else if (INT_CST_LT (integer_minus_one_node, arg0))
9095 /* If the value is negative, then the absolute value is
9099 unsigned HOST_WIDE_INT low;
9101 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
9102 TREE_INT_CST_HIGH (arg0),
9104 t = build_int_2 (low, high);
9105 TREE_TYPE (t) = type;
9107 = (TREE_OVERFLOW (arg0)
9108 | force_fit_type (t, overflow));
9109 TREE_CONSTANT_OVERFLOW (t)
9110 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
9114 else if (TREE_CODE (arg0) == REAL_CST)
9116 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
9117 return build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
9121 #ifdef ENABLE_CHECKING
9129 /* Given CODE, a relational operator, the target type, TYPE and two
9130 constant operands OP0 and OP1, return the result of the
9131 relational operation. If the result is not a compile time
9132 constant, then return NULL_TREE. */
9135 fold_relational_const (enum tree_code code, tree type, tree op0, tree op1)
9140 /* From here on, the only cases we handle are when the result is
9141 known to be a constant.
9143 To compute GT, swap the arguments and do LT.
9144 To compute GE, do LT and invert the result.
9145 To compute LE, swap the arguments, do LT and invert the result.
9146 To compute NE, do EQ and invert the result.
9148 Therefore, the code below must handle only EQ and LT. */
9150 if (code == LE_EXPR || code == GT_EXPR)
9152 tem = op0, op0 = op1, op1 = tem;
9153 code = swap_tree_comparison (code);
9156 /* Note that it is safe to invert for real values here because we
9157 will check below in the one case that it matters. */
9161 if (code == NE_EXPR || code == GE_EXPR)
9164 code = invert_tree_comparison (code);
9167 /* Compute a result for LT or EQ if args permit;
9168 Otherwise return T. */
9169 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
9171 if (code == EQ_EXPR)
9172 tem = build_int_2 (tree_int_cst_equal (op0, op1), 0);
9174 tem = build_int_2 ((TYPE_UNSIGNED (TREE_TYPE (op0))
9175 ? INT_CST_LT_UNSIGNED (op0, op1)
9176 : INT_CST_LT (op0, op1)),
9180 else if (code == EQ_EXPR && !TREE_SIDE_EFFECTS (op0)
9181 && integer_zerop (op1) && tree_expr_nonzero_p (op0))
9182 tem = build_int_2 (0, 0);
9184 /* Two real constants can be compared explicitly. */
9185 else if (TREE_CODE (op0) == REAL_CST && TREE_CODE (op1) == REAL_CST)
9187 /* If either operand is a NaN, the result is false with two
9188 exceptions: First, an NE_EXPR is true on NaNs, but that case
9189 is already handled correctly since we will be inverting the
9190 result for NE_EXPR. Second, if we had inverted a LE_EXPR
9191 or a GE_EXPR into a LT_EXPR, we must return true so that it
9192 will be inverted into false. */
9194 if (REAL_VALUE_ISNAN (TREE_REAL_CST (op0))
9195 || REAL_VALUE_ISNAN (TREE_REAL_CST (op1)))
9196 tem = build_int_2 (invert && code == LT_EXPR, 0);
9198 else if (code == EQ_EXPR)
9199 tem = build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (op0),
9200 TREE_REAL_CST (op1)),
9203 tem = build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (op0),
9204 TREE_REAL_CST (op1)),
9208 if (tem == NULL_TREE)
9212 TREE_INT_CST_LOW (tem) ^= 1;
9214 TREE_TYPE (tem) = type;
9215 if (TREE_CODE (type) == BOOLEAN_TYPE)
9216 return (*lang_hooks.truthvalue_conversion) (tem);
9220 #include "gt-fold-const.h"