1 /* Fold a constant sub-tree into a single node for C-compiler
2 Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
3 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
22 /*@@ This file should be rewritten to use an arbitrary precision
23 @@ representation for "struct tree_int_cst" and "struct tree_real_cst".
24 @@ Perhaps the routines could also be used for bc/dc, and made a lib.
25 @@ The routines that translate from the ap rep should
26 @@ warn if precision et. al. is lost.
27 @@ This would also make life easier when this technology is used
28 @@ for cross-compilers. */
30 /* The entry points in this file are fold, size_int_wide, size_binop
33 fold takes a tree as argument and returns a simplified tree.
35 size_binop takes a tree code for an arithmetic operation
36 and two operands that are trees, and produces a tree for the
37 result, assuming the type comes from `sizetype'.
39 size_int takes an integer value, and creates a tree constant
40 with type from `sizetype'.
42 force_fit_type takes a constant and prior overflow indicator, and
43 forces the value to fit the type. It returns an overflow indicator. */
47 #include "coretypes.h"
58 #include "langhooks.h"
61 /* The following constants represent a bit based encoding of GCC's
62 comparison operators. This encoding simplifies transformations
63 on relational comparison operators, such as AND and OR. */
64 enum comparison_code {
83 static void encode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT, HOST_WIDE_INT);
84 static void decode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
85 static bool negate_mathfn_p (enum built_in_function);
86 static bool negate_expr_p (tree);
87 static tree negate_expr (tree);
88 static tree split_tree (tree, enum tree_code, tree *, tree *, tree *, int);
89 static tree associate_trees (tree, tree, enum tree_code, tree);
90 static tree const_binop (enum tree_code, tree, tree, int);
91 static hashval_t size_htab_hash (const void *);
92 static int size_htab_eq (const void *, const void *);
93 static tree fold_convert_const (enum tree_code, tree, tree);
94 static enum tree_code invert_tree_comparison (enum tree_code, bool);
95 static enum comparison_code comparison_to_compcode (enum tree_code);
96 static enum tree_code compcode_to_comparison (enum comparison_code);
97 static tree combine_comparisons (enum tree_code, enum tree_code,
98 enum tree_code, tree, tree, tree);
99 static int truth_value_p (enum tree_code);
100 static int operand_equal_for_comparison_p (tree, tree, tree);
101 static int twoval_comparison_p (tree, tree *, tree *, int *);
102 static tree eval_subst (tree, tree, tree, tree, tree);
103 static tree pedantic_omit_one_operand (tree, tree, tree);
104 static tree distribute_bit_expr (enum tree_code, tree, tree, tree);
105 static tree make_bit_field_ref (tree, tree, int, int, int);
106 static tree optimize_bit_field_compare (enum tree_code, tree, tree, tree);
107 static tree decode_field_reference (tree, HOST_WIDE_INT *, HOST_WIDE_INT *,
108 enum machine_mode *, int *, int *,
110 static int all_ones_mask_p (tree, int);
111 static tree sign_bit_p (tree, tree);
112 static int simple_operand_p (tree);
113 static tree range_binop (enum tree_code, tree, tree, int, tree, int);
114 static tree make_range (tree, int *, tree *, tree *);
115 static tree build_range_check (tree, tree, int, tree, tree);
116 static int merge_ranges (int *, tree *, tree *, int, tree, tree, int, tree,
118 static tree fold_range_test (tree);
119 static tree fold_cond_expr_with_comparison (tree, tree, tree);
120 static tree unextend (tree, int, int, tree);
121 static tree fold_truthop (enum tree_code, tree, tree, tree);
122 static tree optimize_minmax_comparison (tree);
123 static tree extract_muldiv (tree, tree, enum tree_code, tree);
124 static tree extract_muldiv_1 (tree, tree, enum tree_code, tree);
125 static int multiple_of_p (tree, tree, tree);
126 static tree constant_boolean_node (int, tree);
127 static tree fold_binary_op_with_conditional_arg (enum tree_code, tree, tree,
129 static bool fold_real_zero_addition_p (tree, tree, int);
130 static tree fold_mathfn_compare (enum built_in_function, enum tree_code,
132 static tree fold_inf_compare (enum tree_code, tree, tree, tree);
133 static tree fold_div_compare (enum tree_code, tree, tree, tree);
134 static bool reorder_operands_p (tree, tree);
135 static tree fold_negate_const (tree, tree);
136 static tree fold_not_const (tree, tree);
137 static tree fold_relational_const (enum tree_code, tree, tree, tree);
138 static tree fold_relational_hi_lo (enum tree_code *, const tree,
141 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
142 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
143 and SUM1. Then this yields nonzero if overflow occurred during the
146 Overflow occurs if A and B have the same sign, but A and SUM differ in
147 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
149 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
151 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
152 We do that by representing the two-word integer in 4 words, with only
153 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
154 number. The value of the word is LOWPART + HIGHPART * BASE. */
157 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
158 #define HIGHPART(x) \
159 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
160 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
162 /* Unpack a two-word integer into 4 words.
163 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
164 WORDS points to the array of HOST_WIDE_INTs. */
167 encode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT low, HOST_WIDE_INT hi)
169 words[0] = LOWPART (low);
170 words[1] = HIGHPART (low);
171 words[2] = LOWPART (hi);
172 words[3] = HIGHPART (hi);
175 /* Pack an array of 4 words into a two-word integer.
176 WORDS points to the array of words.
177 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
180 decode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT *low,
183 *low = words[0] + words[1] * BASE;
184 *hi = words[2] + words[3] * BASE;
187 /* Make the integer constant T valid for its type by setting to 0 or 1 all
188 the bits in the constant that don't belong in the type.
190 Return 1 if a signed overflow occurs, 0 otherwise. If OVERFLOW is
191 nonzero, a signed overflow has already occurred in calculating T, so
195 force_fit_type (tree t, int overflow)
197 unsigned HOST_WIDE_INT low;
201 if (TREE_CODE (t) == REAL_CST)
203 /* ??? Used to check for overflow here via CHECK_FLOAT_TYPE.
204 Consider doing it via real_convert now. */
208 else if (TREE_CODE (t) != INTEGER_CST)
211 low = TREE_INT_CST_LOW (t);
212 high = TREE_INT_CST_HIGH (t);
214 if (POINTER_TYPE_P (TREE_TYPE (t))
215 || TREE_CODE (TREE_TYPE (t)) == OFFSET_TYPE)
218 prec = TYPE_PRECISION (TREE_TYPE (t));
220 /* First clear all bits that are beyond the type's precision. */
222 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
224 else if (prec > HOST_BITS_PER_WIDE_INT)
225 TREE_INT_CST_HIGH (t)
226 &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
229 TREE_INT_CST_HIGH (t) = 0;
230 if (prec < HOST_BITS_PER_WIDE_INT)
231 TREE_INT_CST_LOW (t) &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
234 /* Unsigned types do not suffer sign extension or overflow unless they
236 if (TYPE_UNSIGNED (TREE_TYPE (t))
237 && ! (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
238 && TYPE_IS_SIZETYPE (TREE_TYPE (t))))
241 /* If the value's sign bit is set, extend the sign. */
242 if (prec != 2 * HOST_BITS_PER_WIDE_INT
243 && (prec > HOST_BITS_PER_WIDE_INT
244 ? 0 != (TREE_INT_CST_HIGH (t)
246 << (prec - HOST_BITS_PER_WIDE_INT - 1)))
247 : 0 != (TREE_INT_CST_LOW (t)
248 & ((unsigned HOST_WIDE_INT) 1 << (prec - 1)))))
250 /* Value is negative:
251 set to 1 all the bits that are outside this type's precision. */
252 if (prec > HOST_BITS_PER_WIDE_INT)
253 TREE_INT_CST_HIGH (t)
254 |= ((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
257 TREE_INT_CST_HIGH (t) = -1;
258 if (prec < HOST_BITS_PER_WIDE_INT)
259 TREE_INT_CST_LOW (t) |= ((unsigned HOST_WIDE_INT) (-1) << prec);
263 /* Return nonzero if signed overflow occurred. */
265 ((overflow | (low ^ TREE_INT_CST_LOW (t)) | (high ^ TREE_INT_CST_HIGH (t)))
269 /* Add two doubleword integers with doubleword result.
270 Each argument is given as two `HOST_WIDE_INT' pieces.
271 One argument is L1 and H1; the other, L2 and H2.
272 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
275 add_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
276 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
277 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
279 unsigned HOST_WIDE_INT l;
283 h = h1 + h2 + (l < l1);
287 return OVERFLOW_SUM_SIGN (h1, h2, h);
290 /* Negate a doubleword integer with doubleword result.
291 Return nonzero if the operation overflows, assuming it's signed.
292 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
293 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
296 neg_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
297 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
303 return (*hv & h1) < 0;
313 /* Multiply two doubleword integers with doubleword result.
314 Return nonzero if the operation overflows, assuming it's signed.
315 Each argument is given as two `HOST_WIDE_INT' pieces.
316 One argument is L1 and H1; the other, L2 and H2.
317 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
320 mul_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
321 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
322 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
324 HOST_WIDE_INT arg1[4];
325 HOST_WIDE_INT arg2[4];
326 HOST_WIDE_INT prod[4 * 2];
327 unsigned HOST_WIDE_INT carry;
329 unsigned HOST_WIDE_INT toplow, neglow;
330 HOST_WIDE_INT tophigh, neghigh;
332 encode (arg1, l1, h1);
333 encode (arg2, l2, h2);
335 memset (prod, 0, sizeof prod);
337 for (i = 0; i < 4; i++)
340 for (j = 0; j < 4; j++)
343 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
344 carry += arg1[i] * arg2[j];
345 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
347 prod[k] = LOWPART (carry);
348 carry = HIGHPART (carry);
353 decode (prod, lv, hv); /* This ignores prod[4] through prod[4*2-1] */
355 /* Check for overflow by calculating the top half of the answer in full;
356 it should agree with the low half's sign bit. */
357 decode (prod + 4, &toplow, &tophigh);
360 neg_double (l2, h2, &neglow, &neghigh);
361 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
365 neg_double (l1, h1, &neglow, &neghigh);
366 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
368 return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
371 /* Shift the doubleword integer in L1, H1 left by COUNT places
372 keeping only PREC bits of result.
373 Shift right if COUNT is negative.
374 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
375 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
378 lshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
379 HOST_WIDE_INT count, unsigned int prec,
380 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv, int arith)
382 unsigned HOST_WIDE_INT signmask;
386 rshift_double (l1, h1, -count, prec, lv, hv, arith);
390 if (SHIFT_COUNT_TRUNCATED)
393 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
395 /* Shifting by the host word size is undefined according to the
396 ANSI standard, so we must handle this as a special case. */
400 else if (count >= HOST_BITS_PER_WIDE_INT)
402 *hv = l1 << (count - HOST_BITS_PER_WIDE_INT);
407 *hv = (((unsigned HOST_WIDE_INT) h1 << count)
408 | (l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
412 /* Sign extend all bits that are beyond the precision. */
414 signmask = -((prec > HOST_BITS_PER_WIDE_INT
415 ? ((unsigned HOST_WIDE_INT) *hv
416 >> (prec - HOST_BITS_PER_WIDE_INT - 1))
417 : (*lv >> (prec - 1))) & 1);
419 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
421 else if (prec >= HOST_BITS_PER_WIDE_INT)
423 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
424 *hv |= signmask << (prec - HOST_BITS_PER_WIDE_INT);
429 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
430 *lv |= signmask << prec;
434 /* Shift the doubleword integer in L1, H1 right by COUNT places
435 keeping only PREC bits of result. COUNT must be positive.
436 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
437 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
440 rshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
441 HOST_WIDE_INT count, unsigned int prec,
442 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
445 unsigned HOST_WIDE_INT signmask;
448 ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
451 if (SHIFT_COUNT_TRUNCATED)
454 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
456 /* Shifting by the host word size is undefined according to the
457 ANSI standard, so we must handle this as a special case. */
461 else if (count >= HOST_BITS_PER_WIDE_INT)
464 *lv = (unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT);
468 *hv = (unsigned HOST_WIDE_INT) h1 >> count;
470 | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
473 /* Zero / sign extend all bits that are beyond the precision. */
475 if (count >= (HOST_WIDE_INT)prec)
480 else if ((prec - count) >= 2 * HOST_BITS_PER_WIDE_INT)
482 else if ((prec - count) >= HOST_BITS_PER_WIDE_INT)
484 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - count - HOST_BITS_PER_WIDE_INT));
485 *hv |= signmask << (prec - count - HOST_BITS_PER_WIDE_INT);
490 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << (prec - count));
491 *lv |= signmask << (prec - count);
495 /* Rotate the doubleword integer in L1, H1 left by COUNT places
496 keeping only PREC bits of result.
497 Rotate right if COUNT is negative.
498 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
501 lrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
502 HOST_WIDE_INT count, unsigned int prec,
503 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
505 unsigned HOST_WIDE_INT s1l, s2l;
506 HOST_WIDE_INT s1h, s2h;
512 lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
513 rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
518 /* Rotate the doubleword integer in L1, H1 left by COUNT places
519 keeping only PREC bits of result. COUNT must be positive.
520 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
523 rrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
524 HOST_WIDE_INT count, unsigned int prec,
525 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
527 unsigned HOST_WIDE_INT s1l, s2l;
528 HOST_WIDE_INT s1h, s2h;
534 rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
535 lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
540 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
541 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
542 CODE is a tree code for a kind of division, one of
543 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
545 It controls how the quotient is rounded to an integer.
546 Return nonzero if the operation overflows.
547 UNS nonzero says do unsigned division. */
550 div_and_round_double (enum tree_code code, int uns,
551 unsigned HOST_WIDE_INT lnum_orig, /* num == numerator == dividend */
552 HOST_WIDE_INT hnum_orig,
553 unsigned HOST_WIDE_INT lden_orig, /* den == denominator == divisor */
554 HOST_WIDE_INT hden_orig,
555 unsigned HOST_WIDE_INT *lquo,
556 HOST_WIDE_INT *hquo, unsigned HOST_WIDE_INT *lrem,
560 HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
561 HOST_WIDE_INT den[4], quo[4];
563 unsigned HOST_WIDE_INT work;
564 unsigned HOST_WIDE_INT carry = 0;
565 unsigned HOST_WIDE_INT lnum = lnum_orig;
566 HOST_WIDE_INT hnum = hnum_orig;
567 unsigned HOST_WIDE_INT lden = lden_orig;
568 HOST_WIDE_INT hden = hden_orig;
571 if (hden == 0 && lden == 0)
572 overflow = 1, lden = 1;
574 /* Calculate quotient sign and convert operands to unsigned. */
580 /* (minimum integer) / (-1) is the only overflow case. */
581 if (neg_double (lnum, hnum, &lnum, &hnum)
582 && ((HOST_WIDE_INT) lden & hden) == -1)
588 neg_double (lden, hden, &lden, &hden);
592 if (hnum == 0 && hden == 0)
593 { /* single precision */
595 /* This unsigned division rounds toward zero. */
601 { /* trivial case: dividend < divisor */
602 /* hden != 0 already checked. */
609 memset (quo, 0, sizeof quo);
611 memset (num, 0, sizeof num); /* to zero 9th element */
612 memset (den, 0, sizeof den);
614 encode (num, lnum, hnum);
615 encode (den, lden, hden);
617 /* Special code for when the divisor < BASE. */
618 if (hden == 0 && lden < (unsigned HOST_WIDE_INT) BASE)
620 /* hnum != 0 already checked. */
621 for (i = 4 - 1; i >= 0; i--)
623 work = num[i] + carry * BASE;
624 quo[i] = work / lden;
630 /* Full double precision division,
631 with thanks to Don Knuth's "Seminumerical Algorithms". */
632 int num_hi_sig, den_hi_sig;
633 unsigned HOST_WIDE_INT quo_est, scale;
635 /* Find the highest nonzero divisor digit. */
636 for (i = 4 - 1;; i--)
643 /* Insure that the first digit of the divisor is at least BASE/2.
644 This is required by the quotient digit estimation algorithm. */
646 scale = BASE / (den[den_hi_sig] + 1);
648 { /* scale divisor and dividend */
650 for (i = 0; i <= 4 - 1; i++)
652 work = (num[i] * scale) + carry;
653 num[i] = LOWPART (work);
654 carry = HIGHPART (work);
659 for (i = 0; i <= 4 - 1; i++)
661 work = (den[i] * scale) + carry;
662 den[i] = LOWPART (work);
663 carry = HIGHPART (work);
664 if (den[i] != 0) den_hi_sig = i;
671 for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--)
673 /* Guess the next quotient digit, quo_est, by dividing the first
674 two remaining dividend digits by the high order quotient digit.
675 quo_est is never low and is at most 2 high. */
676 unsigned HOST_WIDE_INT tmp;
678 num_hi_sig = i + den_hi_sig + 1;
679 work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
680 if (num[num_hi_sig] != den[den_hi_sig])
681 quo_est = work / den[den_hi_sig];
685 /* Refine quo_est so it's usually correct, and at most one high. */
686 tmp = work - quo_est * den[den_hi_sig];
688 && (den[den_hi_sig - 1] * quo_est
689 > (tmp * BASE + num[num_hi_sig - 2])))
692 /* Try QUO_EST as the quotient digit, by multiplying the
693 divisor by QUO_EST and subtracting from the remaining dividend.
694 Keep in mind that QUO_EST is the I - 1st digit. */
697 for (j = 0; j <= den_hi_sig; j++)
699 work = quo_est * den[j] + carry;
700 carry = HIGHPART (work);
701 work = num[i + j] - LOWPART (work);
702 num[i + j] = LOWPART (work);
703 carry += HIGHPART (work) != 0;
706 /* If quo_est was high by one, then num[i] went negative and
707 we need to correct things. */
708 if (num[num_hi_sig] < (HOST_WIDE_INT) carry)
711 carry = 0; /* add divisor back in */
712 for (j = 0; j <= den_hi_sig; j++)
714 work = num[i + j] + den[j] + carry;
715 carry = HIGHPART (work);
716 num[i + j] = LOWPART (work);
719 num [num_hi_sig] += carry;
722 /* Store the quotient digit. */
727 decode (quo, lquo, hquo);
730 /* If result is negative, make it so. */
732 neg_double (*lquo, *hquo, lquo, hquo);
734 /* Compute trial remainder: rem = num - (quo * den) */
735 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
736 neg_double (*lrem, *hrem, lrem, hrem);
737 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
742 case TRUNC_MOD_EXPR: /* round toward zero */
743 case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
747 case FLOOR_MOD_EXPR: /* round toward negative infinity */
748 if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
751 add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
759 case CEIL_MOD_EXPR: /* round toward positive infinity */
760 if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
762 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
770 case ROUND_MOD_EXPR: /* round to closest integer */
772 unsigned HOST_WIDE_INT labs_rem = *lrem;
773 HOST_WIDE_INT habs_rem = *hrem;
774 unsigned HOST_WIDE_INT labs_den = lden, ltwice;
775 HOST_WIDE_INT habs_den = hden, htwice;
777 /* Get absolute values. */
779 neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
781 neg_double (lden, hden, &labs_den, &habs_den);
783 /* If (2 * abs (lrem) >= abs (lden)) */
784 mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
785 labs_rem, habs_rem, <wice, &htwice);
787 if (((unsigned HOST_WIDE_INT) habs_den
788 < (unsigned HOST_WIDE_INT) htwice)
789 || (((unsigned HOST_WIDE_INT) habs_den
790 == (unsigned HOST_WIDE_INT) htwice)
791 && (labs_den < ltwice)))
795 add_double (*lquo, *hquo,
796 (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
799 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
811 /* Compute true remainder: rem = num - (quo * den) */
812 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
813 neg_double (*lrem, *hrem, lrem, hrem);
814 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
818 /* Return true if built-in mathematical function specified by CODE
819 preserves the sign of it argument, i.e. -f(x) == f(-x). */
822 negate_mathfn_p (enum built_in_function code)
846 /* Determine whether an expression T can be cheaply negated using
847 the function negate_expr. */
850 negate_expr_p (tree t)
852 unsigned HOST_WIDE_INT val;
859 type = TREE_TYPE (t);
862 switch (TREE_CODE (t))
865 if (TYPE_UNSIGNED (type) || ! flag_trapv)
868 /* Check that -CST will not overflow type. */
869 prec = TYPE_PRECISION (type);
870 if (prec > HOST_BITS_PER_WIDE_INT)
872 if (TREE_INT_CST_LOW (t) != 0)
874 prec -= HOST_BITS_PER_WIDE_INT;
875 val = TREE_INT_CST_HIGH (t);
878 val = TREE_INT_CST_LOW (t);
879 if (prec < HOST_BITS_PER_WIDE_INT)
880 val &= ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
881 return val != ((unsigned HOST_WIDE_INT) 1 << (prec - 1));
888 return negate_expr_p (TREE_REALPART (t))
889 && negate_expr_p (TREE_IMAGPART (t));
892 if (FLOAT_TYPE_P (type) && !flag_unsafe_math_optimizations)
894 /* -(A + B) -> (-B) - A. */
895 if (negate_expr_p (TREE_OPERAND (t, 1))
896 && reorder_operands_p (TREE_OPERAND (t, 0),
897 TREE_OPERAND (t, 1)))
899 /* -(A + B) -> (-A) - B. */
900 return negate_expr_p (TREE_OPERAND (t, 0));
903 /* We can't turn -(A-B) into B-A when we honor signed zeros. */
904 return (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
905 && reorder_operands_p (TREE_OPERAND (t, 0),
906 TREE_OPERAND (t, 1));
909 if (TYPE_UNSIGNED (TREE_TYPE (t)))
915 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
916 return negate_expr_p (TREE_OPERAND (t, 1))
917 || negate_expr_p (TREE_OPERAND (t, 0));
921 /* Negate -((double)float) as (double)(-float). */
922 if (TREE_CODE (type) == REAL_TYPE)
924 tree tem = strip_float_extensions (t);
926 return negate_expr_p (tem);
931 /* Negate -f(x) as f(-x). */
932 if (negate_mathfn_p (builtin_mathfn_code (t)))
933 return negate_expr_p (TREE_VALUE (TREE_OPERAND (t, 1)));
937 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
938 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
940 tree op1 = TREE_OPERAND (t, 1);
941 if (TREE_INT_CST_HIGH (op1) == 0
942 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
943 == TREE_INT_CST_LOW (op1))
954 /* Given T, an expression, return the negation of T. Allow for T to be
955 null, in which case return null. */
966 type = TREE_TYPE (t);
969 switch (TREE_CODE (t))
972 tem = fold_negate_const (t, type);
973 if (! TREE_OVERFLOW (tem)
974 || TYPE_UNSIGNED (type)
980 tem = fold_negate_const (t, type);
981 /* Two's complement FP formats, such as c4x, may overflow. */
982 if (! TREE_OVERFLOW (tem) || ! flag_trapping_math)
983 return fold_convert (type, tem);
988 tree rpart = negate_expr (TREE_REALPART (t));
989 tree ipart = negate_expr (TREE_IMAGPART (t));
991 if ((TREE_CODE (rpart) == REAL_CST
992 && TREE_CODE (ipart) == REAL_CST)
993 || (TREE_CODE (rpart) == INTEGER_CST
994 && TREE_CODE (ipart) == INTEGER_CST))
995 return build_complex (type, rpart, ipart);
1000 return fold_convert (type, TREE_OPERAND (t, 0));
1003 if (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
1005 /* -(A + B) -> (-B) - A. */
1006 if (negate_expr_p (TREE_OPERAND (t, 1))
1007 && reorder_operands_p (TREE_OPERAND (t, 0),
1008 TREE_OPERAND (t, 1)))
1010 tem = negate_expr (TREE_OPERAND (t, 1));
1011 tem = fold (build2 (MINUS_EXPR, TREE_TYPE (t),
1012 tem, TREE_OPERAND (t, 0)));
1013 return fold_convert (type, tem);
1016 /* -(A + B) -> (-A) - B. */
1017 if (negate_expr_p (TREE_OPERAND (t, 0)))
1019 tem = negate_expr (TREE_OPERAND (t, 0));
1020 tem = fold (build2 (MINUS_EXPR, TREE_TYPE (t),
1021 tem, TREE_OPERAND (t, 1)));
1022 return fold_convert (type, tem);
1028 /* - (A - B) -> B - A */
1029 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
1030 && reorder_operands_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1)))
1031 return fold_convert (type,
1032 fold (build2 (MINUS_EXPR, TREE_TYPE (t),
1033 TREE_OPERAND (t, 1),
1034 TREE_OPERAND (t, 0))));
1038 if (TYPE_UNSIGNED (TREE_TYPE (t)))
1044 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
1046 tem = TREE_OPERAND (t, 1);
1047 if (negate_expr_p (tem))
1048 return fold_convert (type,
1049 fold (build2 (TREE_CODE (t), TREE_TYPE (t),
1050 TREE_OPERAND (t, 0),
1051 negate_expr (tem))));
1052 tem = TREE_OPERAND (t, 0);
1053 if (negate_expr_p (tem))
1054 return fold_convert (type,
1055 fold (build2 (TREE_CODE (t), TREE_TYPE (t),
1057 TREE_OPERAND (t, 1))));
1062 /* Convert -((double)float) into (double)(-float). */
1063 if (TREE_CODE (type) == REAL_TYPE)
1065 tem = strip_float_extensions (t);
1066 if (tem != t && negate_expr_p (tem))
1067 return fold_convert (type, negate_expr (tem));
1072 /* Negate -f(x) as f(-x). */
1073 if (negate_mathfn_p (builtin_mathfn_code (t))
1074 && negate_expr_p (TREE_VALUE (TREE_OPERAND (t, 1))))
1076 tree fndecl, arg, arglist;
1078 fndecl = get_callee_fndecl (t);
1079 arg = negate_expr (TREE_VALUE (TREE_OPERAND (t, 1)));
1080 arglist = build_tree_list (NULL_TREE, arg);
1081 return build_function_call_expr (fndecl, arglist);
1086 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1087 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
1089 tree op1 = TREE_OPERAND (t, 1);
1090 if (TREE_INT_CST_HIGH (op1) == 0
1091 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
1092 == TREE_INT_CST_LOW (op1))
1094 tree ntype = TYPE_UNSIGNED (type)
1095 ? lang_hooks.types.signed_type (type)
1096 : lang_hooks.types.unsigned_type (type);
1097 tree temp = fold_convert (ntype, TREE_OPERAND (t, 0));
1098 temp = fold (build2 (RSHIFT_EXPR, ntype, temp, op1));
1099 return fold_convert (type, temp);
1108 tem = fold (build1 (NEGATE_EXPR, TREE_TYPE (t), t));
1109 return fold_convert (type, tem);
1112 /* Split a tree IN into a constant, literal and variable parts that could be
1113 combined with CODE to make IN. "constant" means an expression with
1114 TREE_CONSTANT but that isn't an actual constant. CODE must be a
1115 commutative arithmetic operation. Store the constant part into *CONP,
1116 the literal in *LITP and return the variable part. If a part isn't
1117 present, set it to null. If the tree does not decompose in this way,
1118 return the entire tree as the variable part and the other parts as null.
1120 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
1121 case, we negate an operand that was subtracted. Except if it is a
1122 literal for which we use *MINUS_LITP instead.
1124 If NEGATE_P is true, we are negating all of IN, again except a literal
1125 for which we use *MINUS_LITP instead.
1127 If IN is itself a literal or constant, return it as appropriate.
1129 Note that we do not guarantee that any of the three values will be the
1130 same type as IN, but they will have the same signedness and mode. */
1133 split_tree (tree in, enum tree_code code, tree *conp, tree *litp,
1134 tree *minus_litp, int negate_p)
1142 /* Strip any conversions that don't change the machine mode or signedness. */
1143 STRIP_SIGN_NOPS (in);
1145 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST)
1147 else if (TREE_CODE (in) == code
1148 || (! FLOAT_TYPE_P (TREE_TYPE (in))
1149 /* We can associate addition and subtraction together (even
1150 though the C standard doesn't say so) for integers because
1151 the value is not affected. For reals, the value might be
1152 affected, so we can't. */
1153 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
1154 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
1156 tree op0 = TREE_OPERAND (in, 0);
1157 tree op1 = TREE_OPERAND (in, 1);
1158 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
1159 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
1161 /* First see if either of the operands is a literal, then a constant. */
1162 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
1163 *litp = op0, op0 = 0;
1164 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST)
1165 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
1167 if (op0 != 0 && TREE_CONSTANT (op0))
1168 *conp = op0, op0 = 0;
1169 else if (op1 != 0 && TREE_CONSTANT (op1))
1170 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
1172 /* If we haven't dealt with either operand, this is not a case we can
1173 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1174 if (op0 != 0 && op1 != 0)
1179 var = op1, neg_var_p = neg1_p;
1181 /* Now do any needed negations. */
1183 *minus_litp = *litp, *litp = 0;
1185 *conp = negate_expr (*conp);
1187 var = negate_expr (var);
1189 else if (TREE_CONSTANT (in))
1197 *minus_litp = *litp, *litp = 0;
1198 else if (*minus_litp)
1199 *litp = *minus_litp, *minus_litp = 0;
1200 *conp = negate_expr (*conp);
1201 var = negate_expr (var);
1207 /* Re-associate trees split by the above function. T1 and T2 are either
1208 expressions to associate or null. Return the new expression, if any. If
1209 we build an operation, do it in TYPE and with CODE. */
1212 associate_trees (tree t1, tree t2, enum tree_code code, tree type)
1219 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1220 try to fold this since we will have infinite recursion. But do
1221 deal with any NEGATE_EXPRs. */
1222 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
1223 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1225 if (code == PLUS_EXPR)
1227 if (TREE_CODE (t1) == NEGATE_EXPR)
1228 return build2 (MINUS_EXPR, type, fold_convert (type, t2),
1229 fold_convert (type, TREE_OPERAND (t1, 0)));
1230 else if (TREE_CODE (t2) == NEGATE_EXPR)
1231 return build2 (MINUS_EXPR, type, fold_convert (type, t1),
1232 fold_convert (type, TREE_OPERAND (t2, 0)));
1234 return build2 (code, type, fold_convert (type, t1),
1235 fold_convert (type, t2));
1238 return fold (build2 (code, type, fold_convert (type, t1),
1239 fold_convert (type, t2)));
1242 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1243 to produce a new constant.
1245 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1248 int_const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1250 unsigned HOST_WIDE_INT int1l, int2l;
1251 HOST_WIDE_INT int1h, int2h;
1252 unsigned HOST_WIDE_INT low;
1254 unsigned HOST_WIDE_INT garbagel;
1255 HOST_WIDE_INT garbageh;
1257 tree type = TREE_TYPE (arg1);
1258 int uns = TYPE_UNSIGNED (type);
1260 = (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type));
1262 int no_overflow = 0;
1264 int1l = TREE_INT_CST_LOW (arg1);
1265 int1h = TREE_INT_CST_HIGH (arg1);
1266 int2l = TREE_INT_CST_LOW (arg2);
1267 int2h = TREE_INT_CST_HIGH (arg2);
1272 low = int1l | int2l, hi = int1h | int2h;
1276 low = int1l ^ int2l, hi = int1h ^ int2h;
1280 low = int1l & int2l, hi = int1h & int2h;
1286 /* It's unclear from the C standard whether shifts can overflow.
1287 The following code ignores overflow; perhaps a C standard
1288 interpretation ruling is needed. */
1289 lshift_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1297 lrotate_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1302 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1306 neg_double (int2l, int2h, &low, &hi);
1307 add_double (int1l, int1h, low, hi, &low, &hi);
1308 overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
1312 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1315 case TRUNC_DIV_EXPR:
1316 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1317 case EXACT_DIV_EXPR:
1318 /* This is a shortcut for a common special case. */
1319 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1320 && ! TREE_CONSTANT_OVERFLOW (arg1)
1321 && ! TREE_CONSTANT_OVERFLOW (arg2)
1322 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1324 if (code == CEIL_DIV_EXPR)
1327 low = int1l / int2l, hi = 0;
1331 /* ... fall through ... */
1333 case ROUND_DIV_EXPR:
1334 if (int2h == 0 && int2l == 1)
1336 low = int1l, hi = int1h;
1339 if (int1l == int2l && int1h == int2h
1340 && ! (int1l == 0 && int1h == 0))
1345 overflow = div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
1346 &low, &hi, &garbagel, &garbageh);
1349 case TRUNC_MOD_EXPR:
1350 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1351 /* This is a shortcut for a common special case. */
1352 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1353 && ! TREE_CONSTANT_OVERFLOW (arg1)
1354 && ! TREE_CONSTANT_OVERFLOW (arg2)
1355 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1357 if (code == CEIL_MOD_EXPR)
1359 low = int1l % int2l, hi = 0;
1363 /* ... fall through ... */
1365 case ROUND_MOD_EXPR:
1366 overflow = div_and_round_double (code, uns,
1367 int1l, int1h, int2l, int2h,
1368 &garbagel, &garbageh, &low, &hi);
1374 low = (((unsigned HOST_WIDE_INT) int1h
1375 < (unsigned HOST_WIDE_INT) int2h)
1376 || (((unsigned HOST_WIDE_INT) int1h
1377 == (unsigned HOST_WIDE_INT) int2h)
1380 low = (int1h < int2h
1381 || (int1h == int2h && int1l < int2l));
1383 if (low == (code == MIN_EXPR))
1384 low = int1l, hi = int1h;
1386 low = int2l, hi = int2h;
1393 /* If this is for a sizetype, can be represented as one (signed)
1394 HOST_WIDE_INT word, and doesn't overflow, use size_int since it caches
1397 && ((hi == 0 && (HOST_WIDE_INT) low >= 0)
1398 || (hi == -1 && (HOST_WIDE_INT) low < 0))
1399 && overflow == 0 && ! TREE_OVERFLOW (arg1) && ! TREE_OVERFLOW (arg2))
1400 return size_int_type_wide (low, type);
1403 t = build_int_2 (low, hi);
1404 TREE_TYPE (t) = TREE_TYPE (arg1);
1409 ? (!uns || is_sizetype) && overflow
1410 : (force_fit_type (t, (!uns || is_sizetype) && overflow)
1412 | TREE_OVERFLOW (arg1)
1413 | TREE_OVERFLOW (arg2));
1415 /* If we're doing a size calculation, unsigned arithmetic does overflow.
1416 So check if force_fit_type truncated the value. */
1418 && ! TREE_OVERFLOW (t)
1419 && (TREE_INT_CST_HIGH (t) != hi
1420 || TREE_INT_CST_LOW (t) != low))
1421 TREE_OVERFLOW (t) = 1;
1423 TREE_CONSTANT_OVERFLOW (t) = (TREE_OVERFLOW (t)
1424 | TREE_CONSTANT_OVERFLOW (arg1)
1425 | TREE_CONSTANT_OVERFLOW (arg2));
1429 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1430 constant. We assume ARG1 and ARG2 have the same data type, or at least
1431 are the same kind of constant and the same machine mode.
1433 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1436 const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1441 if (TREE_CODE (arg1) == INTEGER_CST)
1442 return int_const_binop (code, arg1, arg2, notrunc);
1444 if (TREE_CODE (arg1) == REAL_CST)
1446 enum machine_mode mode;
1449 REAL_VALUE_TYPE value;
1452 d1 = TREE_REAL_CST (arg1);
1453 d2 = TREE_REAL_CST (arg2);
1455 type = TREE_TYPE (arg1);
1456 mode = TYPE_MODE (type);
1458 /* Don't perform operation if we honor signaling NaNs and
1459 either operand is a NaN. */
1460 if (HONOR_SNANS (mode)
1461 && (REAL_VALUE_ISNAN (d1) || REAL_VALUE_ISNAN (d2)))
1464 /* Don't perform operation if it would raise a division
1465 by zero exception. */
1466 if (code == RDIV_EXPR
1467 && REAL_VALUES_EQUAL (d2, dconst0)
1468 && (flag_trapping_math || ! MODE_HAS_INFINITIES (mode)))
1471 /* If either operand is a NaN, just return it. Otherwise, set up
1472 for floating-point trap; we return an overflow. */
1473 if (REAL_VALUE_ISNAN (d1))
1475 else if (REAL_VALUE_ISNAN (d2))
1478 REAL_ARITHMETIC (value, code, d1, d2);
1480 t = build_real (type, real_value_truncate (mode, value));
1483 = (force_fit_type (t, 0)
1484 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
1485 TREE_CONSTANT_OVERFLOW (t)
1487 | TREE_CONSTANT_OVERFLOW (arg1)
1488 | TREE_CONSTANT_OVERFLOW (arg2);
1491 if (TREE_CODE (arg1) == COMPLEX_CST)
1493 tree type = TREE_TYPE (arg1);
1494 tree r1 = TREE_REALPART (arg1);
1495 tree i1 = TREE_IMAGPART (arg1);
1496 tree r2 = TREE_REALPART (arg2);
1497 tree i2 = TREE_IMAGPART (arg2);
1503 t = build_complex (type,
1504 const_binop (PLUS_EXPR, r1, r2, notrunc),
1505 const_binop (PLUS_EXPR, i1, i2, notrunc));
1509 t = build_complex (type,
1510 const_binop (MINUS_EXPR, r1, r2, notrunc),
1511 const_binop (MINUS_EXPR, i1, i2, notrunc));
1515 t = build_complex (type,
1516 const_binop (MINUS_EXPR,
1517 const_binop (MULT_EXPR,
1519 const_binop (MULT_EXPR,
1522 const_binop (PLUS_EXPR,
1523 const_binop (MULT_EXPR,
1525 const_binop (MULT_EXPR,
1533 = const_binop (PLUS_EXPR,
1534 const_binop (MULT_EXPR, r2, r2, notrunc),
1535 const_binop (MULT_EXPR, i2, i2, notrunc),
1538 t = build_complex (type,
1540 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1541 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1542 const_binop (PLUS_EXPR,
1543 const_binop (MULT_EXPR, r1, r2,
1545 const_binop (MULT_EXPR, i1, i2,
1548 magsquared, notrunc),
1550 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1551 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1552 const_binop (MINUS_EXPR,
1553 const_binop (MULT_EXPR, i1, r2,
1555 const_binop (MULT_EXPR, r1, i2,
1558 magsquared, notrunc));
1570 /* These are the hash table functions for the hash table of INTEGER_CST
1571 nodes of a sizetype. */
1573 /* Return the hash code code X, an INTEGER_CST. */
1576 size_htab_hash (const void *x)
1580 return (TREE_INT_CST_HIGH (t) ^ TREE_INT_CST_LOW (t)
1581 ^ htab_hash_pointer (TREE_TYPE (t))
1582 ^ (TREE_OVERFLOW (t) << 20));
1585 /* Return nonzero if the value represented by *X (an INTEGER_CST tree node)
1586 is the same as that given by *Y, which is the same. */
1589 size_htab_eq (const void *x, const void *y)
1594 return (TREE_INT_CST_HIGH (xt) == TREE_INT_CST_HIGH (yt)
1595 && TREE_INT_CST_LOW (xt) == TREE_INT_CST_LOW (yt)
1596 && TREE_TYPE (xt) == TREE_TYPE (yt)
1597 && TREE_OVERFLOW (xt) == TREE_OVERFLOW (yt));
1600 /* Return an INTEGER_CST with value whose low-order HOST_BITS_PER_WIDE_INT
1601 bits are given by NUMBER and of the sizetype represented by KIND. */
1604 size_int_wide (HOST_WIDE_INT number, enum size_type_kind kind)
1606 return size_int_type_wide (number, sizetype_tab[(int) kind]);
1609 /* Likewise, but the desired type is specified explicitly. */
1611 static GTY (()) tree new_const;
1612 static GTY ((if_marked ("ggc_marked_p"), param_is (union tree_node)))
1616 size_int_type_wide (HOST_WIDE_INT number, tree type)
1622 size_htab = htab_create_ggc (1024, size_htab_hash, size_htab_eq, NULL);
1623 new_const = make_node (INTEGER_CST);
1626 /* Adjust NEW_CONST to be the constant we want. If it's already in the
1627 hash table, we return the value from the hash table. Otherwise, we
1628 place that in the hash table and make a new node for the next time. */
1629 TREE_INT_CST_LOW (new_const) = number;
1630 TREE_INT_CST_HIGH (new_const) = number < 0 ? -1 : 0;
1631 TREE_TYPE (new_const) = type;
1632 TREE_OVERFLOW (new_const) = TREE_CONSTANT_OVERFLOW (new_const)
1633 = force_fit_type (new_const, 0);
1635 slot = htab_find_slot (size_htab, new_const, INSERT);
1641 new_const = make_node (INTEGER_CST);
1645 return (tree) *slot;
1648 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1649 is a tree code. The type of the result is taken from the operands.
1650 Both must be the same type integer type and it must be a size type.
1651 If the operands are constant, so is the result. */
1654 size_binop (enum tree_code code, tree arg0, tree arg1)
1656 tree type = TREE_TYPE (arg0);
1658 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1659 || type != TREE_TYPE (arg1))
1662 /* Handle the special case of two integer constants faster. */
1663 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1665 /* And some specific cases even faster than that. */
1666 if (code == PLUS_EXPR && integer_zerop (arg0))
1668 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1669 && integer_zerop (arg1))
1671 else if (code == MULT_EXPR && integer_onep (arg0))
1674 /* Handle general case of two integer constants. */
1675 return int_const_binop (code, arg0, arg1, 0);
1678 if (arg0 == error_mark_node || arg1 == error_mark_node)
1679 return error_mark_node;
1681 return fold (build2 (code, type, arg0, arg1));
1684 /* Given two values, either both of sizetype or both of bitsizetype,
1685 compute the difference between the two values. Return the value
1686 in signed type corresponding to the type of the operands. */
1689 size_diffop (tree arg0, tree arg1)
1691 tree type = TREE_TYPE (arg0);
1694 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1695 || type != TREE_TYPE (arg1))
1698 /* If the type is already signed, just do the simple thing. */
1699 if (!TYPE_UNSIGNED (type))
1700 return size_binop (MINUS_EXPR, arg0, arg1);
1702 ctype = (type == bitsizetype || type == ubitsizetype
1703 ? sbitsizetype : ssizetype);
1705 /* If either operand is not a constant, do the conversions to the signed
1706 type and subtract. The hardware will do the right thing with any
1707 overflow in the subtraction. */
1708 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
1709 return size_binop (MINUS_EXPR, fold_convert (ctype, arg0),
1710 fold_convert (ctype, arg1));
1712 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
1713 Otherwise, subtract the other way, convert to CTYPE (we know that can't
1714 overflow) and negate (which can't either). Special-case a result
1715 of zero while we're here. */
1716 if (tree_int_cst_equal (arg0, arg1))
1717 return fold_convert (ctype, integer_zero_node);
1718 else if (tree_int_cst_lt (arg1, arg0))
1719 return fold_convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
1721 return size_binop (MINUS_EXPR, fold_convert (ctype, integer_zero_node),
1722 fold_convert (ctype, size_binop (MINUS_EXPR,
1727 /* Attempt to fold type conversion operation CODE of expression ARG1 to
1728 type TYPE. If no simplification can be done return NULL_TREE. */
1731 fold_convert_const (enum tree_code code, tree type, tree arg1)
1736 if (TREE_TYPE (arg1) == type)
1739 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
1741 if (TREE_CODE (arg1) == INTEGER_CST)
1743 /* If we would build a constant wider than GCC supports,
1744 leave the conversion unfolded. */
1745 if (TYPE_PRECISION (type) > 2 * HOST_BITS_PER_WIDE_INT)
1748 /* If we are trying to make a sizetype for a small integer, use
1749 size_int to pick up cached types to reduce duplicate nodes. */
1750 if (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type)
1751 && !TREE_CONSTANT_OVERFLOW (arg1)
1752 && compare_tree_int (arg1, 10000) < 0)
1753 return size_int_type_wide (TREE_INT_CST_LOW (arg1), type);
1755 /* Given an integer constant, make new constant with new type,
1756 appropriately sign-extended or truncated. */
1757 t = build_int_2 (TREE_INT_CST_LOW (arg1),
1758 TREE_INT_CST_HIGH (arg1));
1759 TREE_TYPE (t) = type;
1760 /* Indicate an overflow if (1) ARG1 already overflowed,
1761 or (2) force_fit_type indicates an overflow.
1762 Tell force_fit_type that an overflow has already occurred
1763 if ARG1 is a too-large unsigned value and T is signed.
1764 But don't indicate an overflow if converting a pointer. */
1766 = ((force_fit_type (t,
1767 (TREE_INT_CST_HIGH (arg1) < 0
1768 && (TYPE_UNSIGNED (type)
1769 < TYPE_UNSIGNED (TREE_TYPE (arg1)))))
1770 && ! POINTER_TYPE_P (TREE_TYPE (arg1)))
1771 || TREE_OVERFLOW (arg1));
1772 TREE_CONSTANT_OVERFLOW (t)
1773 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1776 else if (TREE_CODE (arg1) == REAL_CST)
1778 /* The following code implements the floating point to integer
1779 conversion rules required by the Java Language Specification,
1780 that IEEE NaNs are mapped to zero and values that overflow
1781 the target precision saturate, i.e. values greater than
1782 INT_MAX are mapped to INT_MAX, and values less than INT_MIN
1783 are mapped to INT_MIN. These semantics are allowed by the
1784 C and C++ standards that simply state that the behavior of
1785 FP-to-integer conversion is unspecified upon overflow. */
1787 HOST_WIDE_INT high, low;
1790 REAL_VALUE_TYPE x = TREE_REAL_CST (arg1);
1794 case FIX_TRUNC_EXPR:
1795 real_trunc (&r, VOIDmode, &x);
1799 real_ceil (&r, VOIDmode, &x);
1802 case FIX_FLOOR_EXPR:
1803 real_floor (&r, VOIDmode, &x);
1806 case FIX_ROUND_EXPR:
1807 real_round (&r, VOIDmode, &x);
1814 /* If R is NaN, return zero and show we have an overflow. */
1815 if (REAL_VALUE_ISNAN (r))
1822 /* See if R is less than the lower bound or greater than the
1827 tree lt = TYPE_MIN_VALUE (type);
1828 REAL_VALUE_TYPE l = real_value_from_int_cst (NULL_TREE, lt);
1829 if (REAL_VALUES_LESS (r, l))
1832 high = TREE_INT_CST_HIGH (lt);
1833 low = TREE_INT_CST_LOW (lt);
1839 tree ut = TYPE_MAX_VALUE (type);
1842 REAL_VALUE_TYPE u = real_value_from_int_cst (NULL_TREE, ut);
1843 if (REAL_VALUES_LESS (u, r))
1846 high = TREE_INT_CST_HIGH (ut);
1847 low = TREE_INT_CST_LOW (ut);
1853 REAL_VALUE_TO_INT (&low, &high, r);
1855 t = build_int_2 (low, high);
1856 TREE_TYPE (t) = type;
1858 = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
1859 TREE_CONSTANT_OVERFLOW (t)
1860 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1864 else if (TREE_CODE (type) == REAL_TYPE)
1866 if (TREE_CODE (arg1) == INTEGER_CST)
1867 return build_real_from_int_cst (type, arg1);
1868 if (TREE_CODE (arg1) == REAL_CST)
1870 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
1872 /* We make a copy of ARG1 so that we don't modify an
1873 existing constant tree. */
1874 t = copy_node (arg1);
1875 TREE_TYPE (t) = type;
1879 t = build_real (type,
1880 real_value_truncate (TYPE_MODE (type),
1881 TREE_REAL_CST (arg1)));
1884 = TREE_OVERFLOW (arg1) | force_fit_type (t, 0);
1885 TREE_CONSTANT_OVERFLOW (t)
1886 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1893 /* Convert expression ARG to type TYPE. Used by the middle-end for
1894 simple conversions in preference to calling the front-end's convert. */
1897 fold_convert (tree type, tree arg)
1899 tree orig = TREE_TYPE (arg);
1905 if (TREE_CODE (arg) == ERROR_MARK
1906 || TREE_CODE (type) == ERROR_MARK
1907 || TREE_CODE (orig) == ERROR_MARK)
1908 return error_mark_node;
1910 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig))
1911 return fold (build1 (NOP_EXPR, type, arg));
1913 if (INTEGRAL_TYPE_P (type) || POINTER_TYPE_P (type)
1914 || TREE_CODE (type) == OFFSET_TYPE)
1916 if (TREE_CODE (arg) == INTEGER_CST)
1918 tem = fold_convert_const (NOP_EXPR, type, arg);
1919 if (tem != NULL_TREE)
1922 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
1923 || TREE_CODE (orig) == OFFSET_TYPE)
1924 return fold (build1 (NOP_EXPR, type, arg));
1925 if (TREE_CODE (orig) == COMPLEX_TYPE)
1927 tem = fold (build1 (REALPART_EXPR, TREE_TYPE (orig), arg));
1928 return fold_convert (type, tem);
1930 if (TREE_CODE (orig) == VECTOR_TYPE
1931 && GET_MODE_SIZE (TYPE_MODE (type))
1932 == GET_MODE_SIZE (TYPE_MODE (orig)))
1933 return fold (build1 (NOP_EXPR, type, arg));
1935 else if (TREE_CODE (type) == REAL_TYPE)
1937 if (TREE_CODE (arg) == INTEGER_CST)
1939 tem = fold_convert_const (FLOAT_EXPR, type, arg);
1940 if (tem != NULL_TREE)
1943 else if (TREE_CODE (arg) == REAL_CST)
1945 tem = fold_convert_const (NOP_EXPR, type, arg);
1946 if (tem != NULL_TREE)
1950 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig))
1951 return fold (build1 (FLOAT_EXPR, type, arg));
1952 if (TREE_CODE (orig) == REAL_TYPE)
1953 return fold (build1 (flag_float_store ? CONVERT_EXPR : NOP_EXPR,
1955 if (TREE_CODE (orig) == COMPLEX_TYPE)
1957 tem = fold (build1 (REALPART_EXPR, TREE_TYPE (orig), arg));
1958 return fold_convert (type, tem);
1961 else if (TREE_CODE (type) == COMPLEX_TYPE)
1963 if (INTEGRAL_TYPE_P (orig)
1964 || POINTER_TYPE_P (orig)
1965 || TREE_CODE (orig) == REAL_TYPE)
1966 return build2 (COMPLEX_EXPR, type,
1967 fold_convert (TREE_TYPE (type), arg),
1968 fold_convert (TREE_TYPE (type), integer_zero_node));
1969 if (TREE_CODE (orig) == COMPLEX_TYPE)
1973 if (TREE_CODE (arg) == COMPLEX_EXPR)
1975 rpart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 0));
1976 ipart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 1));
1977 return fold (build2 (COMPLEX_EXPR, type, rpart, ipart));
1980 arg = save_expr (arg);
1981 rpart = fold (build1 (REALPART_EXPR, TREE_TYPE (orig), arg));
1982 ipart = fold (build1 (IMAGPART_EXPR, TREE_TYPE (orig), arg));
1983 rpart = fold_convert (TREE_TYPE (type), rpart);
1984 ipart = fold_convert (TREE_TYPE (type), ipart);
1985 return fold (build2 (COMPLEX_EXPR, type, rpart, ipart));
1988 else if (TREE_CODE (type) == VECTOR_TYPE)
1990 if ((INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig))
1991 && GET_MODE_SIZE (TYPE_MODE (type))
1992 == GET_MODE_SIZE (TYPE_MODE (orig)))
1993 return fold (build1 (NOP_EXPR, type, arg));
1994 if (TREE_CODE (orig) == VECTOR_TYPE
1995 && GET_MODE_SIZE (TYPE_MODE (type))
1996 == GET_MODE_SIZE (TYPE_MODE (orig)))
1997 return fold (build1 (NOP_EXPR, type, arg));
1999 else if (VOID_TYPE_P (type))
2000 return fold (build1 (CONVERT_EXPR, type, arg));
2004 /* Return an expr equal to X but certainly not valid as an lvalue. */
2009 /* We only need to wrap lvalue tree codes. */
2010 switch (TREE_CODE (x))
2022 case ARRAY_RANGE_REF:
2029 case PREINCREMENT_EXPR:
2030 case PREDECREMENT_EXPR:
2033 case TRY_CATCH_EXPR:
2034 case WITH_CLEANUP_EXPR:
2046 /* Assume the worst for front-end tree codes. */
2047 if ((int)TREE_CODE (x) >= NUM_TREE_CODES)
2051 return build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
2054 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
2055 Zero means allow extended lvalues. */
2057 int pedantic_lvalues;
2059 /* When pedantic, return an expr equal to X but certainly not valid as a
2060 pedantic lvalue. Otherwise, return X. */
2063 pedantic_non_lvalue (tree x)
2065 if (pedantic_lvalues)
2066 return non_lvalue (x);
2071 /* Given a tree comparison code, return the code that is the logical inverse
2072 of the given code. It is not safe to do this for floating-point
2073 comparisons, except for NE_EXPR and EQ_EXPR, so we receive a machine mode
2074 as well: if reversing the comparison is unsafe, return ERROR_MARK. */
2076 static enum tree_code
2077 invert_tree_comparison (enum tree_code code, bool honor_nans)
2079 if (honor_nans && flag_trapping_math)
2089 return honor_nans ? UNLE_EXPR : LE_EXPR;
2091 return honor_nans ? UNLT_EXPR : LT_EXPR;
2093 return honor_nans ? UNGE_EXPR : GE_EXPR;
2095 return honor_nans ? UNGT_EXPR : GT_EXPR;
2109 return UNORDERED_EXPR;
2110 case UNORDERED_EXPR:
2111 return ORDERED_EXPR;
2117 /* Similar, but return the comparison that results if the operands are
2118 swapped. This is safe for floating-point. */
2121 swap_tree_comparison (enum tree_code code)
2142 /* Convert a comparison tree code from an enum tree_code representation
2143 into a compcode bit-based encoding. This function is the inverse of
2144 compcode_to_comparison. */
2146 static enum comparison_code
2147 comparison_to_compcode (enum tree_code code)
2164 return COMPCODE_ORD;
2165 case UNORDERED_EXPR:
2166 return COMPCODE_UNORD;
2168 return COMPCODE_UNLT;
2170 return COMPCODE_UNEQ;
2172 return COMPCODE_UNLE;
2174 return COMPCODE_UNGT;
2176 return COMPCODE_LTGT;
2178 return COMPCODE_UNGE;
2184 /* Convert a compcode bit-based encoding of a comparison operator back
2185 to GCC's enum tree_code representation. This function is the
2186 inverse of comparison_to_compcode. */
2188 static enum tree_code
2189 compcode_to_comparison (enum comparison_code code)
2206 return ORDERED_EXPR;
2207 case COMPCODE_UNORD:
2208 return UNORDERED_EXPR;
2226 /* Return a tree for the comparison which is the combination of
2227 doing the AND or OR (depending on CODE) of the two operations LCODE
2228 and RCODE on the identical operands LL_ARG and LR_ARG. Take into account
2229 the possibility of trapping if the mode has NaNs, and return NULL_TREE
2230 if this makes the transformation invalid. */
2233 combine_comparisons (enum tree_code code, enum tree_code lcode,
2234 enum tree_code rcode, tree truth_type,
2235 tree ll_arg, tree lr_arg)
2237 bool honor_nans = HONOR_NANS (TYPE_MODE (TREE_TYPE (ll_arg)));
2238 enum comparison_code lcompcode = comparison_to_compcode (lcode);
2239 enum comparison_code rcompcode = comparison_to_compcode (rcode);
2240 enum comparison_code compcode;
2244 case TRUTH_AND_EXPR: case TRUTH_ANDIF_EXPR:
2245 compcode = lcompcode & rcompcode;
2248 case TRUTH_OR_EXPR: case TRUTH_ORIF_EXPR:
2249 compcode = lcompcode | rcompcode;
2258 /* Eliminate unordered comparisons, as well as LTGT and ORD
2259 which are not used unless the mode has NaNs. */
2260 compcode &= ~COMPCODE_UNORD;
2261 if (compcode == COMPCODE_LTGT)
2262 compcode = COMPCODE_NE;
2263 else if (compcode == COMPCODE_ORD)
2264 compcode = COMPCODE_TRUE;
2266 else if (flag_trapping_math)
2268 /* Check that the original operation and the optimized ones will trap
2269 under the same condition. */
2270 bool ltrap = (lcompcode & COMPCODE_UNORD) == 0
2271 && (lcompcode != COMPCODE_EQ)
2272 && (lcompcode != COMPCODE_ORD);
2273 bool rtrap = (rcompcode & COMPCODE_UNORD) == 0
2274 && (rcompcode != COMPCODE_EQ)
2275 && (rcompcode != COMPCODE_ORD);
2276 bool trap = (compcode & COMPCODE_UNORD) == 0
2277 && (compcode != COMPCODE_EQ)
2278 && (compcode != COMPCODE_ORD);
2280 /* In a short-circuited boolean expression the LHS might be
2281 such that the RHS, if evaluated, will never trap. For
2282 example, in ORD (x, y) && (x < y), we evaluate the RHS only
2283 if neither x nor y is NaN. (This is a mixed blessing: for
2284 example, the expression above will never trap, hence
2285 optimizing it to x < y would be invalid). */
2286 if ((code == TRUTH_ORIF_EXPR && (lcompcode & COMPCODE_UNORD))
2287 || (code == TRUTH_ANDIF_EXPR && !(lcompcode & COMPCODE_UNORD)))
2290 /* If the comparison was short-circuited, and only the RHS
2291 trapped, we may now generate a spurious trap. */
2293 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2296 /* If we changed the conditions that cause a trap, we lose. */
2297 if ((ltrap || rtrap) != trap)
2301 if (compcode == COMPCODE_TRUE)
2302 return constant_boolean_node (true, truth_type);
2303 else if (compcode == COMPCODE_FALSE)
2304 return constant_boolean_node (false, truth_type);
2306 return fold (build2 (compcode_to_comparison (compcode),
2307 truth_type, ll_arg, lr_arg));
2310 /* Return nonzero if CODE is a tree code that represents a truth value. */
2313 truth_value_p (enum tree_code code)
2315 return (TREE_CODE_CLASS (code) == '<'
2316 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2317 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2318 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
2321 /* Return nonzero if two operands (typically of the same tree node)
2322 are necessarily equal. If either argument has side-effects this
2323 function returns zero. FLAGS modifies behavior as follows:
2325 If OEP_ONLY_CONST is set, only return nonzero for constants.
2326 This function tests whether the operands are indistinguishable;
2327 it does not test whether they are equal using C's == operation.
2328 The distinction is important for IEEE floating point, because
2329 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2330 (2) two NaNs may be indistinguishable, but NaN!=NaN.
2332 If OEP_ONLY_CONST is unset, a VAR_DECL is considered equal to itself
2333 even though it may hold multiple values during a function.
2334 This is because a GCC tree node guarantees that nothing else is
2335 executed between the evaluation of its "operands" (which may often
2336 be evaluated in arbitrary order). Hence if the operands themselves
2337 don't side-effect, the VAR_DECLs, PARM_DECLs etc... must hold the
2338 same value in each operand/subexpression. Hence leaving OEP_ONLY_CONST
2339 unset means assuming isochronic (or instantaneous) tree equivalence.
2340 Unless comparing arbitrary expression trees, such as from different
2341 statements, this flag can usually be left unset.
2343 If OEP_PURE_SAME is set, then pure functions with identical arguments
2344 are considered the same. It is used when the caller has other ways
2345 to ensure that global memory is unchanged in between. */
2348 operand_equal_p (tree arg0, tree arg1, unsigned int flags)
2350 /* If either is ERROR_MARK, they aren't equal. */
2351 if (TREE_CODE (arg0) == ERROR_MARK || TREE_CODE (arg1) == ERROR_MARK)
2354 /* If both types don't have the same signedness, then we can't consider
2355 them equal. We must check this before the STRIP_NOPS calls
2356 because they may change the signedness of the arguments. */
2357 if (TYPE_UNSIGNED (TREE_TYPE (arg0)) != TYPE_UNSIGNED (TREE_TYPE (arg1)))
2363 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2364 /* This is needed for conversions and for COMPONENT_REF.
2365 Might as well play it safe and always test this. */
2366 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
2367 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
2368 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
2371 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
2372 We don't care about side effects in that case because the SAVE_EXPR
2373 takes care of that for us. In all other cases, two expressions are
2374 equal if they have no side effects. If we have two identical
2375 expressions with side effects that should be treated the same due
2376 to the only side effects being identical SAVE_EXPR's, that will
2377 be detected in the recursive calls below. */
2378 if (arg0 == arg1 && ! (flags & OEP_ONLY_CONST)
2379 && (TREE_CODE (arg0) == SAVE_EXPR
2380 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
2383 /* Next handle constant cases, those for which we can return 1 even
2384 if ONLY_CONST is set. */
2385 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
2386 switch (TREE_CODE (arg0))
2389 return (! TREE_CONSTANT_OVERFLOW (arg0)
2390 && ! TREE_CONSTANT_OVERFLOW (arg1)
2391 && tree_int_cst_equal (arg0, arg1));
2394 return (! TREE_CONSTANT_OVERFLOW (arg0)
2395 && ! TREE_CONSTANT_OVERFLOW (arg1)
2396 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
2397 TREE_REAL_CST (arg1)));
2403 if (TREE_CONSTANT_OVERFLOW (arg0)
2404 || TREE_CONSTANT_OVERFLOW (arg1))
2407 v1 = TREE_VECTOR_CST_ELTS (arg0);
2408 v2 = TREE_VECTOR_CST_ELTS (arg1);
2411 if (!operand_equal_p (TREE_VALUE (v1), TREE_VALUE (v2),
2414 v1 = TREE_CHAIN (v1);
2415 v2 = TREE_CHAIN (v2);
2422 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
2424 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
2428 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
2429 && ! memcmp (TREE_STRING_POINTER (arg0),
2430 TREE_STRING_POINTER (arg1),
2431 TREE_STRING_LENGTH (arg0)));
2434 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
2440 if (flags & OEP_ONLY_CONST)
2443 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
2446 /* Two conversions are equal only if signedness and modes match. */
2447 if ((TREE_CODE (arg0) == NOP_EXPR || TREE_CODE (arg0) == CONVERT_EXPR)
2448 && (TYPE_UNSIGNED (TREE_TYPE (arg0))
2449 != TYPE_UNSIGNED (TREE_TYPE (arg1))))
2452 return operand_equal_p (TREE_OPERAND (arg0, 0),
2453 TREE_OPERAND (arg1, 0), flags);
2457 if (operand_equal_p (TREE_OPERAND (arg0, 0),
2458 TREE_OPERAND (arg1, 0), flags)
2459 && operand_equal_p (TREE_OPERAND (arg0, 1),
2460 TREE_OPERAND (arg1, 1), flags))
2463 /* For commutative ops, allow the other order. */
2464 return (commutative_tree_code (TREE_CODE (arg0))
2465 && operand_equal_p (TREE_OPERAND (arg0, 0),
2466 TREE_OPERAND (arg1, 1), flags)
2467 && operand_equal_p (TREE_OPERAND (arg0, 1),
2468 TREE_OPERAND (arg1, 0), flags));
2471 /* If either of the pointer (or reference) expressions we are
2472 dereferencing contain a side effect, these cannot be equal. */
2473 if (TREE_SIDE_EFFECTS (arg0)
2474 || TREE_SIDE_EFFECTS (arg1))
2477 switch (TREE_CODE (arg0))
2480 return operand_equal_p (TREE_OPERAND (arg0, 0),
2481 TREE_OPERAND (arg1, 0), flags);
2485 case ARRAY_RANGE_REF:
2486 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2487 TREE_OPERAND (arg1, 0), flags)
2488 && operand_equal_p (TREE_OPERAND (arg0, 1),
2489 TREE_OPERAND (arg1, 1), flags));
2492 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2493 TREE_OPERAND (arg1, 0), flags)
2494 && operand_equal_p (TREE_OPERAND (arg0, 1),
2495 TREE_OPERAND (arg1, 1), flags)
2496 && operand_equal_p (TREE_OPERAND (arg0, 2),
2497 TREE_OPERAND (arg1, 2), flags));
2503 switch (TREE_CODE (arg0))
2506 case TRUTH_NOT_EXPR:
2507 return operand_equal_p (TREE_OPERAND (arg0, 0),
2508 TREE_OPERAND (arg1, 0), flags);
2510 case TRUTH_ANDIF_EXPR:
2511 case TRUTH_ORIF_EXPR:
2512 return operand_equal_p (TREE_OPERAND (arg0, 0),
2513 TREE_OPERAND (arg1, 0), flags)
2514 && operand_equal_p (TREE_OPERAND (arg0, 1),
2515 TREE_OPERAND (arg1, 1), flags);
2517 case TRUTH_AND_EXPR:
2519 case TRUTH_XOR_EXPR:
2520 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2521 TREE_OPERAND (arg1, 0), flags)
2522 && operand_equal_p (TREE_OPERAND (arg0, 1),
2523 TREE_OPERAND (arg1, 1), flags))
2524 || (operand_equal_p (TREE_OPERAND (arg0, 0),
2525 TREE_OPERAND (arg1, 1), flags)
2526 && operand_equal_p (TREE_OPERAND (arg0, 1),
2527 TREE_OPERAND (arg1, 0), flags));
2530 return rtx_equal_p (RTL_EXPR_RTL (arg0), RTL_EXPR_RTL (arg1));
2533 /* If the CALL_EXPRs call different functions, then they
2534 clearly can not be equal. */
2535 if (! operand_equal_p (TREE_OPERAND (arg0, 0),
2536 TREE_OPERAND (arg1, 0), flags))
2540 unsigned int cef = call_expr_flags (arg0);
2541 if (flags & OEP_PURE_SAME)
2542 cef &= ECF_CONST | ECF_PURE;
2549 /* Now see if all the arguments are the same. operand_equal_p
2550 does not handle TREE_LIST, so we walk the operands here
2551 feeding them to operand_equal_p. */
2552 arg0 = TREE_OPERAND (arg0, 1);
2553 arg1 = TREE_OPERAND (arg1, 1);
2554 while (arg0 && arg1)
2556 if (! operand_equal_p (TREE_VALUE (arg0), TREE_VALUE (arg1),
2560 arg0 = TREE_CHAIN (arg0);
2561 arg1 = TREE_CHAIN (arg1);
2564 /* If we get here and both argument lists are exhausted
2565 then the CALL_EXPRs are equal. */
2566 return ! (arg0 || arg1);
2573 /* Consider __builtin_sqrt equal to sqrt. */
2574 return (TREE_CODE (arg0) == FUNCTION_DECL
2575 && DECL_BUILT_IN (arg0) && DECL_BUILT_IN (arg1)
2576 && DECL_BUILT_IN_CLASS (arg0) == DECL_BUILT_IN_CLASS (arg1)
2577 && DECL_FUNCTION_CODE (arg0) == DECL_FUNCTION_CODE (arg1));
2584 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2585 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2587 When in doubt, return 0. */
2590 operand_equal_for_comparison_p (tree arg0, tree arg1, tree other)
2592 int unsignedp1, unsignedpo;
2593 tree primarg0, primarg1, primother;
2594 unsigned int correct_width;
2596 if (operand_equal_p (arg0, arg1, 0))
2599 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
2600 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
2603 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2604 and see if the inner values are the same. This removes any
2605 signedness comparison, which doesn't matter here. */
2606 primarg0 = arg0, primarg1 = arg1;
2607 STRIP_NOPS (primarg0);
2608 STRIP_NOPS (primarg1);
2609 if (operand_equal_p (primarg0, primarg1, 0))
2612 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2613 actual comparison operand, ARG0.
2615 First throw away any conversions to wider types
2616 already present in the operands. */
2618 primarg1 = get_narrower (arg1, &unsignedp1);
2619 primother = get_narrower (other, &unsignedpo);
2621 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
2622 if (unsignedp1 == unsignedpo
2623 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
2624 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
2626 tree type = TREE_TYPE (arg0);
2628 /* Make sure shorter operand is extended the right way
2629 to match the longer operand. */
2630 primarg1 = fold_convert (lang_hooks.types.signed_or_unsigned_type
2631 (unsignedp1, TREE_TYPE (primarg1)), primarg1);
2633 if (operand_equal_p (arg0, fold_convert (type, primarg1), 0))
2640 /* See if ARG is an expression that is either a comparison or is performing
2641 arithmetic on comparisons. The comparisons must only be comparing
2642 two different values, which will be stored in *CVAL1 and *CVAL2; if
2643 they are nonzero it means that some operands have already been found.
2644 No variables may be used anywhere else in the expression except in the
2645 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2646 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2648 If this is true, return 1. Otherwise, return zero. */
2651 twoval_comparison_p (tree arg, tree *cval1, tree *cval2, int *save_p)
2653 enum tree_code code = TREE_CODE (arg);
2654 char class = TREE_CODE_CLASS (code);
2656 /* We can handle some of the 'e' cases here. */
2657 if (class == 'e' && code == TRUTH_NOT_EXPR)
2659 else if (class == 'e'
2660 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
2661 || code == COMPOUND_EXPR))
2664 else if (class == 'e' && code == SAVE_EXPR && SAVE_EXPR_RTL (arg) == 0
2665 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
2667 /* If we've already found a CVAL1 or CVAL2, this expression is
2668 two complex to handle. */
2669 if (*cval1 || *cval2)
2679 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
2682 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
2683 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2684 cval1, cval2, save_p));
2690 if (code == COND_EXPR)
2691 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
2692 cval1, cval2, save_p)
2693 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2694 cval1, cval2, save_p)
2695 && twoval_comparison_p (TREE_OPERAND (arg, 2),
2696 cval1, cval2, save_p));
2700 /* First see if we can handle the first operand, then the second. For
2701 the second operand, we know *CVAL1 can't be zero. It must be that
2702 one side of the comparison is each of the values; test for the
2703 case where this isn't true by failing if the two operands
2706 if (operand_equal_p (TREE_OPERAND (arg, 0),
2707 TREE_OPERAND (arg, 1), 0))
2711 *cval1 = TREE_OPERAND (arg, 0);
2712 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
2714 else if (*cval2 == 0)
2715 *cval2 = TREE_OPERAND (arg, 0);
2716 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
2721 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
2723 else if (*cval2 == 0)
2724 *cval2 = TREE_OPERAND (arg, 1);
2725 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
2737 /* ARG is a tree that is known to contain just arithmetic operations and
2738 comparisons. Evaluate the operations in the tree substituting NEW0 for
2739 any occurrence of OLD0 as an operand of a comparison and likewise for
2743 eval_subst (tree arg, tree old0, tree new0, tree old1, tree new1)
2745 tree type = TREE_TYPE (arg);
2746 enum tree_code code = TREE_CODE (arg);
2747 char class = TREE_CODE_CLASS (code);
2749 /* We can handle some of the 'e' cases here. */
2750 if (class == 'e' && code == TRUTH_NOT_EXPR)
2752 else if (class == 'e'
2753 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2759 return fold (build1 (code, type,
2760 eval_subst (TREE_OPERAND (arg, 0),
2761 old0, new0, old1, new1)));
2764 return fold (build2 (code, type,
2765 eval_subst (TREE_OPERAND (arg, 0),
2766 old0, new0, old1, new1),
2767 eval_subst (TREE_OPERAND (arg, 1),
2768 old0, new0, old1, new1)));
2774 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
2777 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
2780 return fold (build3 (code, type,
2781 eval_subst (TREE_OPERAND (arg, 0),
2782 old0, new0, old1, new1),
2783 eval_subst (TREE_OPERAND (arg, 1),
2784 old0, new0, old1, new1),
2785 eval_subst (TREE_OPERAND (arg, 2),
2786 old0, new0, old1, new1)));
2790 /* Fall through - ??? */
2794 tree arg0 = TREE_OPERAND (arg, 0);
2795 tree arg1 = TREE_OPERAND (arg, 1);
2797 /* We need to check both for exact equality and tree equality. The
2798 former will be true if the operand has a side-effect. In that
2799 case, we know the operand occurred exactly once. */
2801 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
2803 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
2806 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
2808 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
2811 return fold (build2 (code, type, arg0, arg1));
2819 /* Return a tree for the case when the result of an expression is RESULT
2820 converted to TYPE and OMITTED was previously an operand of the expression
2821 but is now not needed (e.g., we folded OMITTED * 0).
2823 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2824 the conversion of RESULT to TYPE. */
2827 omit_one_operand (tree type, tree result, tree omitted)
2829 tree t = fold_convert (type, result);
2831 if (TREE_SIDE_EFFECTS (omitted))
2832 return build2 (COMPOUND_EXPR, type, omitted, t);
2834 return non_lvalue (t);
2837 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2840 pedantic_omit_one_operand (tree type, tree result, tree omitted)
2842 tree t = fold_convert (type, result);
2844 if (TREE_SIDE_EFFECTS (omitted))
2845 return build2 (COMPOUND_EXPR, type, omitted, t);
2847 return pedantic_non_lvalue (t);
2850 /* Return a tree for the case when the result of an expression is RESULT
2851 converted to TYPE and OMITTED1 and OMITTED2 were previously operands
2852 of the expression but are now not needed.
2854 If OMITTED1 or OMITTED2 has side effects, they must be evaluated.
2855 If both OMITTED1 and OMITTED2 have side effects, OMITTED1 is
2856 evaluated before OMITTED2. Otherwise, if neither has side effects,
2857 just do the conversion of RESULT to TYPE. */
2860 omit_two_operands (tree type, tree result, tree omitted1, tree omitted2)
2862 tree t = fold_convert (type, result);
2864 if (TREE_SIDE_EFFECTS (omitted2))
2865 t = build2 (COMPOUND_EXPR, type, omitted2, t);
2866 if (TREE_SIDE_EFFECTS (omitted1))
2867 t = build2 (COMPOUND_EXPR, type, omitted1, t);
2869 return TREE_CODE (t) != COMPOUND_EXPR ? non_lvalue (t) : t;
2873 /* Return a simplified tree node for the truth-negation of ARG. This
2874 never alters ARG itself. We assume that ARG is an operation that
2875 returns a truth value (0 or 1).
2877 FIXME: one would think we would fold the result, but it causes
2878 problems with the dominator optimizer. */
2880 invert_truthvalue (tree arg)
2882 tree type = TREE_TYPE (arg);
2883 enum tree_code code = TREE_CODE (arg);
2885 if (code == ERROR_MARK)
2888 /* If this is a comparison, we can simply invert it, except for
2889 floating-point non-equality comparisons, in which case we just
2890 enclose a TRUTH_NOT_EXPR around what we have. */
2892 if (TREE_CODE_CLASS (code) == '<')
2894 tree op_type = TREE_TYPE (TREE_OPERAND (arg, 0));
2895 if (FLOAT_TYPE_P (op_type)
2896 && flag_trapping_math
2897 && code != ORDERED_EXPR && code != UNORDERED_EXPR
2898 && code != NE_EXPR && code != EQ_EXPR)
2899 return build1 (TRUTH_NOT_EXPR, type, arg);
2902 code = invert_tree_comparison (code,
2903 HONOR_NANS (TYPE_MODE (op_type)));
2904 if (code == ERROR_MARK)
2905 return build1 (TRUTH_NOT_EXPR, type, arg);
2907 return build2 (code, type,
2908 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
2915 return fold_convert (type, build_int_2 (integer_zerop (arg), 0));
2917 case TRUTH_AND_EXPR:
2918 return build2 (TRUTH_OR_EXPR, type,
2919 invert_truthvalue (TREE_OPERAND (arg, 0)),
2920 invert_truthvalue (TREE_OPERAND (arg, 1)));
2923 return build2 (TRUTH_AND_EXPR, type,
2924 invert_truthvalue (TREE_OPERAND (arg, 0)),
2925 invert_truthvalue (TREE_OPERAND (arg, 1)));
2927 case TRUTH_XOR_EXPR:
2928 /* Here we can invert either operand. We invert the first operand
2929 unless the second operand is a TRUTH_NOT_EXPR in which case our
2930 result is the XOR of the first operand with the inside of the
2931 negation of the second operand. */
2933 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
2934 return build2 (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
2935 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
2937 return build2 (TRUTH_XOR_EXPR, type,
2938 invert_truthvalue (TREE_OPERAND (arg, 0)),
2939 TREE_OPERAND (arg, 1));
2941 case TRUTH_ANDIF_EXPR:
2942 return build2 (TRUTH_ORIF_EXPR, type,
2943 invert_truthvalue (TREE_OPERAND (arg, 0)),
2944 invert_truthvalue (TREE_OPERAND (arg, 1)));
2946 case TRUTH_ORIF_EXPR:
2947 return build2 (TRUTH_ANDIF_EXPR, type,
2948 invert_truthvalue (TREE_OPERAND (arg, 0)),
2949 invert_truthvalue (TREE_OPERAND (arg, 1)));
2951 case TRUTH_NOT_EXPR:
2952 return TREE_OPERAND (arg, 0);
2955 return build3 (COND_EXPR, type, TREE_OPERAND (arg, 0),
2956 invert_truthvalue (TREE_OPERAND (arg, 1)),
2957 invert_truthvalue (TREE_OPERAND (arg, 2)));
2960 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
2961 invert_truthvalue (TREE_OPERAND (arg, 1)));
2963 case NON_LVALUE_EXPR:
2964 return invert_truthvalue (TREE_OPERAND (arg, 0));
2967 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE)
2972 return build1 (TREE_CODE (arg), type,
2973 invert_truthvalue (TREE_OPERAND (arg, 0)));
2976 if (!integer_onep (TREE_OPERAND (arg, 1)))
2978 return build2 (EQ_EXPR, type, arg,
2979 fold_convert (type, integer_zero_node));
2982 return build1 (TRUTH_NOT_EXPR, type, arg);
2984 case CLEANUP_POINT_EXPR:
2985 return build1 (CLEANUP_POINT_EXPR, type,
2986 invert_truthvalue (TREE_OPERAND (arg, 0)));
2991 if (TREE_CODE (TREE_TYPE (arg)) != BOOLEAN_TYPE)
2993 return build1 (TRUTH_NOT_EXPR, type, arg);
2996 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
2997 operands are another bit-wise operation with a common input. If so,
2998 distribute the bit operations to save an operation and possibly two if
2999 constants are involved. For example, convert
3000 (A | B) & (A | C) into A | (B & C)
3001 Further simplification will occur if B and C are constants.
3003 If this optimization cannot be done, 0 will be returned. */
3006 distribute_bit_expr (enum tree_code code, tree type, tree arg0, tree arg1)
3011 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3012 || TREE_CODE (arg0) == code
3013 || (TREE_CODE (arg0) != BIT_AND_EXPR
3014 && TREE_CODE (arg0) != BIT_IOR_EXPR))
3017 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
3019 common = TREE_OPERAND (arg0, 0);
3020 left = TREE_OPERAND (arg0, 1);
3021 right = TREE_OPERAND (arg1, 1);
3023 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
3025 common = TREE_OPERAND (arg0, 0);
3026 left = TREE_OPERAND (arg0, 1);
3027 right = TREE_OPERAND (arg1, 0);
3029 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
3031 common = TREE_OPERAND (arg0, 1);
3032 left = TREE_OPERAND (arg0, 0);
3033 right = TREE_OPERAND (arg1, 1);
3035 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
3037 common = TREE_OPERAND (arg0, 1);
3038 left = TREE_OPERAND (arg0, 0);
3039 right = TREE_OPERAND (arg1, 0);
3044 return fold (build2 (TREE_CODE (arg0), type, common,
3045 fold (build2 (code, type, left, right))));
3048 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
3049 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
3052 make_bit_field_ref (tree inner, tree type, int bitsize, int bitpos,
3055 tree result = build3 (BIT_FIELD_REF, type, inner,
3056 size_int (bitsize), bitsize_int (bitpos));
3058 BIT_FIELD_REF_UNSIGNED (result) = unsignedp;
3063 /* Optimize a bit-field compare.
3065 There are two cases: First is a compare against a constant and the
3066 second is a comparison of two items where the fields are at the same
3067 bit position relative to the start of a chunk (byte, halfword, word)
3068 large enough to contain it. In these cases we can avoid the shift
3069 implicit in bitfield extractions.
3071 For constants, we emit a compare of the shifted constant with the
3072 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
3073 compared. For two fields at the same position, we do the ANDs with the
3074 similar mask and compare the result of the ANDs.
3076 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
3077 COMPARE_TYPE is the type of the comparison, and LHS and RHS
3078 are the left and right operands of the comparison, respectively.
3080 If the optimization described above can be done, we return the resulting
3081 tree. Otherwise we return zero. */
3084 optimize_bit_field_compare (enum tree_code code, tree compare_type,
3087 HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
3088 tree type = TREE_TYPE (lhs);
3089 tree signed_type, unsigned_type;
3090 int const_p = TREE_CODE (rhs) == INTEGER_CST;
3091 enum machine_mode lmode, rmode, nmode;
3092 int lunsignedp, runsignedp;
3093 int lvolatilep = 0, rvolatilep = 0;
3094 tree linner, rinner = NULL_TREE;
3098 /* Get all the information about the extractions being done. If the bit size
3099 if the same as the size of the underlying object, we aren't doing an
3100 extraction at all and so can do nothing. We also don't want to
3101 do anything if the inner expression is a PLACEHOLDER_EXPR since we
3102 then will no longer be able to replace it. */
3103 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
3104 &lunsignedp, &lvolatilep);
3105 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
3106 || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
3111 /* If this is not a constant, we can only do something if bit positions,
3112 sizes, and signedness are the same. */
3113 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
3114 &runsignedp, &rvolatilep);
3116 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
3117 || lunsignedp != runsignedp || offset != 0
3118 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
3122 /* See if we can find a mode to refer to this field. We should be able to,
3123 but fail if we can't. */
3124 nmode = get_best_mode (lbitsize, lbitpos,
3125 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
3126 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
3127 TYPE_ALIGN (TREE_TYPE (rinner))),
3128 word_mode, lvolatilep || rvolatilep);
3129 if (nmode == VOIDmode)
3132 /* Set signed and unsigned types of the precision of this mode for the
3134 signed_type = lang_hooks.types.type_for_mode (nmode, 0);
3135 unsigned_type = lang_hooks.types.type_for_mode (nmode, 1);
3137 /* Compute the bit position and size for the new reference and our offset
3138 within it. If the new reference is the same size as the original, we
3139 won't optimize anything, so return zero. */
3140 nbitsize = GET_MODE_BITSIZE (nmode);
3141 nbitpos = lbitpos & ~ (nbitsize - 1);
3143 if (nbitsize == lbitsize)
3146 if (BYTES_BIG_ENDIAN)
3147 lbitpos = nbitsize - lbitsize - lbitpos;
3149 /* Make the mask to be used against the extracted field. */
3150 mask = build_int_2 (~0, ~0);
3151 TREE_TYPE (mask) = unsigned_type;
3152 force_fit_type (mask, 0);
3153 mask = fold_convert (unsigned_type, mask);
3154 mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
3155 mask = const_binop (RSHIFT_EXPR, mask,
3156 size_int (nbitsize - lbitsize - lbitpos), 0);
3159 /* If not comparing with constant, just rework the comparison
3161 return build2 (code, compare_type,
3162 build2 (BIT_AND_EXPR, unsigned_type,
3163 make_bit_field_ref (linner, unsigned_type,
3164 nbitsize, nbitpos, 1),
3166 build2 (BIT_AND_EXPR, unsigned_type,
3167 make_bit_field_ref (rinner, unsigned_type,
3168 nbitsize, nbitpos, 1),
3171 /* Otherwise, we are handling the constant case. See if the constant is too
3172 big for the field. Warn and return a tree of for 0 (false) if so. We do
3173 this not only for its own sake, but to avoid having to test for this
3174 error case below. If we didn't, we might generate wrong code.
3176 For unsigned fields, the constant shifted right by the field length should
3177 be all zero. For signed fields, the high-order bits should agree with
3182 if (! integer_zerop (const_binop (RSHIFT_EXPR,
3183 fold_convert (unsigned_type, rhs),
3184 size_int (lbitsize), 0)))
3186 warning ("comparison is always %d due to width of bit-field",
3188 return constant_boolean_node (code == NE_EXPR, compare_type);
3193 tree tem = const_binop (RSHIFT_EXPR, fold_convert (signed_type, rhs),
3194 size_int (lbitsize - 1), 0);
3195 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
3197 warning ("comparison is always %d due to width of bit-field",
3199 return constant_boolean_node (code == NE_EXPR, compare_type);
3203 /* Single-bit compares should always be against zero. */
3204 if (lbitsize == 1 && ! integer_zerop (rhs))
3206 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
3207 rhs = fold_convert (type, integer_zero_node);
3210 /* Make a new bitfield reference, shift the constant over the
3211 appropriate number of bits and mask it with the computed mask
3212 (in case this was a signed field). If we changed it, make a new one. */
3213 lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1);
3216 TREE_SIDE_EFFECTS (lhs) = 1;
3217 TREE_THIS_VOLATILE (lhs) = 1;
3220 rhs = fold (const_binop (BIT_AND_EXPR,
3221 const_binop (LSHIFT_EXPR,
3222 fold_convert (unsigned_type, rhs),
3223 size_int (lbitpos), 0),
3226 return build2 (code, compare_type,
3227 build2 (BIT_AND_EXPR, unsigned_type, lhs, mask),
3231 /* Subroutine for fold_truthop: decode a field reference.
3233 If EXP is a comparison reference, we return the innermost reference.
3235 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
3236 set to the starting bit number.
3238 If the innermost field can be completely contained in a mode-sized
3239 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
3241 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
3242 otherwise it is not changed.
3244 *PUNSIGNEDP is set to the signedness of the field.
3246 *PMASK is set to the mask used. This is either contained in a
3247 BIT_AND_EXPR or derived from the width of the field.
3249 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
3251 Return 0 if this is not a component reference or is one that we can't
3252 do anything with. */
3255 decode_field_reference (tree exp, HOST_WIDE_INT *pbitsize,
3256 HOST_WIDE_INT *pbitpos, enum machine_mode *pmode,
3257 int *punsignedp, int *pvolatilep,
3258 tree *pmask, tree *pand_mask)
3260 tree outer_type = 0;
3262 tree mask, inner, offset;
3264 unsigned int precision;
3266 /* All the optimizations using this function assume integer fields.
3267 There are problems with FP fields since the type_for_size call
3268 below can fail for, e.g., XFmode. */
3269 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
3272 /* We are interested in the bare arrangement of bits, so strip everything
3273 that doesn't affect the machine mode. However, record the type of the
3274 outermost expression if it may matter below. */
3275 if (TREE_CODE (exp) == NOP_EXPR
3276 || TREE_CODE (exp) == CONVERT_EXPR
3277 || TREE_CODE (exp) == NON_LVALUE_EXPR)
3278 outer_type = TREE_TYPE (exp);
3281 if (TREE_CODE (exp) == BIT_AND_EXPR)
3283 and_mask = TREE_OPERAND (exp, 1);
3284 exp = TREE_OPERAND (exp, 0);
3285 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
3286 if (TREE_CODE (and_mask) != INTEGER_CST)
3290 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
3291 punsignedp, pvolatilep);
3292 if ((inner == exp && and_mask == 0)
3293 || *pbitsize < 0 || offset != 0
3294 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
3297 /* If the number of bits in the reference is the same as the bitsize of
3298 the outer type, then the outer type gives the signedness. Otherwise
3299 (in case of a small bitfield) the signedness is unchanged. */
3300 if (outer_type && *pbitsize == tree_low_cst (TYPE_SIZE (outer_type), 1))
3301 *punsignedp = TYPE_UNSIGNED (outer_type);
3303 /* Compute the mask to access the bitfield. */
3304 unsigned_type = lang_hooks.types.type_for_size (*pbitsize, 1);
3305 precision = TYPE_PRECISION (unsigned_type);
3307 mask = build_int_2 (~0, ~0);
3308 TREE_TYPE (mask) = unsigned_type;
3309 force_fit_type (mask, 0);
3310 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3311 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3313 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
3315 mask = fold (build2 (BIT_AND_EXPR, unsigned_type,
3316 fold_convert (unsigned_type, and_mask), mask));
3319 *pand_mask = and_mask;
3323 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
3327 all_ones_mask_p (tree mask, int size)
3329 tree type = TREE_TYPE (mask);
3330 unsigned int precision = TYPE_PRECISION (type);
3333 tmask = build_int_2 (~0, ~0);
3334 TREE_TYPE (tmask) = lang_hooks.types.signed_type (type);
3335 force_fit_type (tmask, 0);
3337 tree_int_cst_equal (mask,
3338 const_binop (RSHIFT_EXPR,
3339 const_binop (LSHIFT_EXPR, tmask,
3340 size_int (precision - size),
3342 size_int (precision - size), 0));
3345 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
3346 represents the sign bit of EXP's type. If EXP represents a sign
3347 or zero extension, also test VAL against the unextended type.
3348 The return value is the (sub)expression whose sign bit is VAL,
3349 or NULL_TREE otherwise. */
3352 sign_bit_p (tree exp, tree val)
3354 unsigned HOST_WIDE_INT mask_lo, lo;
3355 HOST_WIDE_INT mask_hi, hi;
3359 /* Tree EXP must have an integral type. */
3360 t = TREE_TYPE (exp);
3361 if (! INTEGRAL_TYPE_P (t))
3364 /* Tree VAL must be an integer constant. */
3365 if (TREE_CODE (val) != INTEGER_CST
3366 || TREE_CONSTANT_OVERFLOW (val))
3369 width = TYPE_PRECISION (t);
3370 if (width > HOST_BITS_PER_WIDE_INT)
3372 hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1);
3375 mask_hi = ((unsigned HOST_WIDE_INT) -1
3376 >> (2 * HOST_BITS_PER_WIDE_INT - width));
3382 lo = (unsigned HOST_WIDE_INT) 1 << (width - 1);
3385 mask_lo = ((unsigned HOST_WIDE_INT) -1
3386 >> (HOST_BITS_PER_WIDE_INT - width));
3389 /* We mask off those bits beyond TREE_TYPE (exp) so that we can
3390 treat VAL as if it were unsigned. */
3391 if ((TREE_INT_CST_HIGH (val) & mask_hi) == hi
3392 && (TREE_INT_CST_LOW (val) & mask_lo) == lo)
3395 /* Handle extension from a narrower type. */
3396 if (TREE_CODE (exp) == NOP_EXPR
3397 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width)
3398 return sign_bit_p (TREE_OPERAND (exp, 0), val);
3403 /* Subroutine for fold_truthop: determine if an operand is simple enough
3404 to be evaluated unconditionally. */
3407 simple_operand_p (tree exp)
3409 /* Strip any conversions that don't change the machine mode. */
3410 while ((TREE_CODE (exp) == NOP_EXPR
3411 || TREE_CODE (exp) == CONVERT_EXPR)
3412 && (TYPE_MODE (TREE_TYPE (exp))
3413 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)))))
3414 exp = TREE_OPERAND (exp, 0);
3416 return (TREE_CODE_CLASS (TREE_CODE (exp)) == 'c'
3418 && ! TREE_ADDRESSABLE (exp)
3419 && ! TREE_THIS_VOLATILE (exp)
3420 && ! DECL_NONLOCAL (exp)
3421 /* Don't regard global variables as simple. They may be
3422 allocated in ways unknown to the compiler (shared memory,
3423 #pragma weak, etc). */
3424 && ! TREE_PUBLIC (exp)
3425 && ! DECL_EXTERNAL (exp)
3426 /* Loading a static variable is unduly expensive, but global
3427 registers aren't expensive. */
3428 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
3431 /* The following functions are subroutines to fold_range_test and allow it to
3432 try to change a logical combination of comparisons into a range test.
3435 X == 2 || X == 3 || X == 4 || X == 5
3439 (unsigned) (X - 2) <= 3
3441 We describe each set of comparisons as being either inside or outside
3442 a range, using a variable named like IN_P, and then describe the
3443 range with a lower and upper bound. If one of the bounds is omitted,
3444 it represents either the highest or lowest value of the type.
3446 In the comments below, we represent a range by two numbers in brackets
3447 preceded by a "+" to designate being inside that range, or a "-" to
3448 designate being outside that range, so the condition can be inverted by
3449 flipping the prefix. An omitted bound is represented by a "-". For
3450 example, "- [-, 10]" means being outside the range starting at the lowest
3451 possible value and ending at 10, in other words, being greater than 10.
3452 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
3455 We set up things so that the missing bounds are handled in a consistent
3456 manner so neither a missing bound nor "true" and "false" need to be
3457 handled using a special case. */
3459 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
3460 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
3461 and UPPER1_P are nonzero if the respective argument is an upper bound
3462 and zero for a lower. TYPE, if nonzero, is the type of the result; it
3463 must be specified for a comparison. ARG1 will be converted to ARG0's
3464 type if both are specified. */
3467 range_binop (enum tree_code code, tree type, tree arg0, int upper0_p,
3468 tree arg1, int upper1_p)
3474 /* If neither arg represents infinity, do the normal operation.
3475 Else, if not a comparison, return infinity. Else handle the special
3476 comparison rules. Note that most of the cases below won't occur, but
3477 are handled for consistency. */
3479 if (arg0 != 0 && arg1 != 0)
3481 tem = fold (build2 (code, type != 0 ? type : TREE_TYPE (arg0),
3482 arg0, fold_convert (TREE_TYPE (arg0), arg1)));
3484 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
3487 if (TREE_CODE_CLASS (code) != '<')
3490 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
3491 for neither. In real maths, we cannot assume open ended ranges are
3492 the same. But, this is computer arithmetic, where numbers are finite.
3493 We can therefore make the transformation of any unbounded range with
3494 the value Z, Z being greater than any representable number. This permits
3495 us to treat unbounded ranges as equal. */
3496 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
3497 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
3501 result = sgn0 == sgn1;
3504 result = sgn0 != sgn1;
3507 result = sgn0 < sgn1;
3510 result = sgn0 <= sgn1;
3513 result = sgn0 > sgn1;
3516 result = sgn0 >= sgn1;
3522 return constant_boolean_node (result, type);
3525 /* Given EXP, a logical expression, set the range it is testing into
3526 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
3527 actually being tested. *PLOW and *PHIGH will be made of the same type
3528 as the returned expression. If EXP is not a comparison, we will most
3529 likely not be returning a useful value and range. */
3532 make_range (tree exp, int *pin_p, tree *plow, tree *phigh)
3534 enum tree_code code;
3535 tree arg0 = NULL_TREE, arg1 = NULL_TREE, type = NULL_TREE;
3536 tree orig_type = NULL_TREE;
3538 tree low, high, n_low, n_high;
3540 /* Start with simply saying "EXP != 0" and then look at the code of EXP
3541 and see if we can refine the range. Some of the cases below may not
3542 happen, but it doesn't seem worth worrying about this. We "continue"
3543 the outer loop when we've changed something; otherwise we "break"
3544 the switch, which will "break" the while. */
3547 low = high = fold_convert (TREE_TYPE (exp), integer_zero_node);
3551 code = TREE_CODE (exp);
3553 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
3555 if (first_rtl_op (code) > 0)
3556 arg0 = TREE_OPERAND (exp, 0);
3557 if (TREE_CODE_CLASS (code) == '<'
3558 || TREE_CODE_CLASS (code) == '1'
3559 || TREE_CODE_CLASS (code) == '2')
3560 type = TREE_TYPE (arg0);
3561 if (TREE_CODE_CLASS (code) == '2'
3562 || TREE_CODE_CLASS (code) == '<'
3563 || (TREE_CODE_CLASS (code) == 'e'
3564 && TREE_CODE_LENGTH (code) > 1))
3565 arg1 = TREE_OPERAND (exp, 1);
3568 /* Set ORIG_TYPE as soon as TYPE is non-null so that we do not
3569 lose a cast by accident. */
3570 if (type != NULL_TREE && orig_type == NULL_TREE)
3575 case TRUTH_NOT_EXPR:
3576 in_p = ! in_p, exp = arg0;
3579 case EQ_EXPR: case NE_EXPR:
3580 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
3581 /* We can only do something if the range is testing for zero
3582 and if the second operand is an integer constant. Note that
3583 saying something is "in" the range we make is done by
3584 complementing IN_P since it will set in the initial case of
3585 being not equal to zero; "out" is leaving it alone. */
3586 if (low == 0 || high == 0
3587 || ! integer_zerop (low) || ! integer_zerop (high)
3588 || TREE_CODE (arg1) != INTEGER_CST)
3593 case NE_EXPR: /* - [c, c] */
3596 case EQ_EXPR: /* + [c, c] */
3597 in_p = ! in_p, low = high = arg1;
3599 case GT_EXPR: /* - [-, c] */
3600 low = 0, high = arg1;
3602 case GE_EXPR: /* + [c, -] */
3603 in_p = ! in_p, low = arg1, high = 0;
3605 case LT_EXPR: /* - [c, -] */
3606 low = arg1, high = 0;
3608 case LE_EXPR: /* + [-, c] */
3609 in_p = ! in_p, low = 0, high = arg1;
3617 /* If this is an unsigned comparison, we also know that EXP is
3618 greater than or equal to zero. We base the range tests we make
3619 on that fact, so we record it here so we can parse existing
3621 if (TYPE_UNSIGNED (type) && (low == 0 || high == 0))
3623 if (! merge_ranges (&n_in_p, &n_low, &n_high, in_p, low, high,
3624 1, fold_convert (type, integer_zero_node),
3628 in_p = n_in_p, low = n_low, high = n_high;
3630 /* If the high bound is missing, but we have a nonzero low
3631 bound, reverse the range so it goes from zero to the low bound
3633 if (high == 0 && low && ! integer_zerop (low))
3636 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
3637 integer_one_node, 0);
3638 low = fold_convert (type, integer_zero_node);
3644 /* (-x) IN [a,b] -> x in [-b, -a] */
3645 n_low = range_binop (MINUS_EXPR, type,
3646 fold_convert (type, integer_zero_node),
3648 n_high = range_binop (MINUS_EXPR, type,
3649 fold_convert (type, integer_zero_node),
3651 low = n_low, high = n_high;
3657 exp = build2 (MINUS_EXPR, type, negate_expr (arg0),
3658 fold_convert (type, integer_one_node));
3661 case PLUS_EXPR: case MINUS_EXPR:
3662 if (TREE_CODE (arg1) != INTEGER_CST)
3665 /* If EXP is signed, any overflow in the computation is undefined,
3666 so we don't worry about it so long as our computations on
3667 the bounds don't overflow. For unsigned, overflow is defined
3668 and this is exactly the right thing. */
3669 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3670 type, low, 0, arg1, 0);
3671 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3672 type, high, 1, arg1, 0);
3673 if ((n_low != 0 && TREE_OVERFLOW (n_low))
3674 || (n_high != 0 && TREE_OVERFLOW (n_high)))
3677 /* Check for an unsigned range which has wrapped around the maximum
3678 value thus making n_high < n_low, and normalize it. */
3679 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
3681 low = range_binop (PLUS_EXPR, type, n_high, 0,
3682 integer_one_node, 0);
3683 high = range_binop (MINUS_EXPR, type, n_low, 0,
3684 integer_one_node, 0);
3686 /* If the range is of the form +/- [ x+1, x ], we won't
3687 be able to normalize it. But then, it represents the
3688 whole range or the empty set, so make it
3690 if (tree_int_cst_equal (n_low, low)
3691 && tree_int_cst_equal (n_high, high))
3697 low = n_low, high = n_high;
3702 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
3703 if (TYPE_PRECISION (type) > TYPE_PRECISION (orig_type))
3706 if (! INTEGRAL_TYPE_P (type)
3707 || (low != 0 && ! int_fits_type_p (low, type))
3708 || (high != 0 && ! int_fits_type_p (high, type)))
3711 n_low = low, n_high = high;
3714 n_low = fold_convert (type, n_low);
3717 n_high = fold_convert (type, n_high);
3719 /* If we're converting from an unsigned to a signed type,
3720 we will be doing the comparison as unsigned. The tests above
3721 have already verified that LOW and HIGH are both positive.
3723 So we have to make sure that the original unsigned value will
3724 be interpreted as positive. */
3725 if (TYPE_UNSIGNED (type) && ! TYPE_UNSIGNED (TREE_TYPE (exp)))
3727 tree equiv_type = lang_hooks.types.type_for_mode
3728 (TYPE_MODE (type), 1);
3731 /* A range without an upper bound is, naturally, unbounded.
3732 Since convert would have cropped a very large value, use
3733 the max value for the destination type. */
3735 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
3736 : TYPE_MAX_VALUE (type);
3738 if (TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (exp)))
3739 high_positive = fold (build2 (RSHIFT_EXPR, type,
3743 integer_one_node)));
3745 /* If the low bound is specified, "and" the range with the
3746 range for which the original unsigned value will be
3750 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3751 1, n_low, n_high, 1,
3752 fold_convert (type, integer_zero_node),
3756 in_p = (n_in_p == in_p);
3760 /* Otherwise, "or" the range with the range of the input
3761 that will be interpreted as negative. */
3762 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3763 0, n_low, n_high, 1,
3764 fold_convert (type, integer_zero_node),
3768 in_p = (in_p != n_in_p);
3773 low = n_low, high = n_high;
3783 /* If EXP is a constant, we can evaluate whether this is true or false. */
3784 if (TREE_CODE (exp) == INTEGER_CST)
3786 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
3788 && integer_onep (range_binop (LE_EXPR, integer_type_node,
3794 *pin_p = in_p, *plow = low, *phigh = high;
3798 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3799 type, TYPE, return an expression to test if EXP is in (or out of, depending
3800 on IN_P) the range. Return 0 if the test couldn't be created. */
3803 build_range_check (tree type, tree exp, int in_p, tree low, tree high)
3805 tree etype = TREE_TYPE (exp);
3810 value = build_range_check (type, exp, 1, low, high);
3812 return invert_truthvalue (value);
3817 if (low == 0 && high == 0)
3818 return fold_convert (type, integer_one_node);
3821 return fold (build2 (LE_EXPR, type, exp, high));
3824 return fold (build2 (GE_EXPR, type, exp, low));
3826 if (operand_equal_p (low, high, 0))
3827 return fold (build2 (EQ_EXPR, type, exp, low));
3829 if (integer_zerop (low))
3831 if (! TYPE_UNSIGNED (etype))
3833 etype = lang_hooks.types.unsigned_type (etype);
3834 high = fold_convert (etype, high);
3835 exp = fold_convert (etype, exp);
3837 return build_range_check (type, exp, 1, 0, high);
3840 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
3841 if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST)
3843 unsigned HOST_WIDE_INT lo;
3847 prec = TYPE_PRECISION (etype);
3848 if (prec <= HOST_BITS_PER_WIDE_INT)
3851 lo = ((unsigned HOST_WIDE_INT) 1 << (prec - 1)) - 1;
3855 hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1;
3856 lo = (unsigned HOST_WIDE_INT) -1;
3859 if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo)
3861 if (TYPE_UNSIGNED (etype))
3863 etype = lang_hooks.types.signed_type (etype);
3864 exp = fold_convert (etype, exp);
3866 return fold (build2 (GT_EXPR, type, exp,
3867 fold_convert (etype, integer_zero_node)));
3871 value = const_binop (MINUS_EXPR, high, low, 0);
3872 if (value != 0 && TREE_OVERFLOW (value) && ! TYPE_UNSIGNED (etype))
3874 tree utype, minv, maxv;
3876 /* Check if (unsigned) INT_MAX + 1 == (unsigned) INT_MIN
3877 for the type in question, as we rely on this here. */
3878 switch (TREE_CODE (etype))
3883 utype = lang_hooks.types.unsigned_type (etype);
3884 maxv = fold_convert (utype, TYPE_MAX_VALUE (etype));
3885 maxv = range_binop (PLUS_EXPR, NULL_TREE, maxv, 1,
3886 integer_one_node, 1);
3887 minv = fold_convert (utype, TYPE_MIN_VALUE (etype));
3888 if (integer_zerop (range_binop (NE_EXPR, integer_type_node,
3892 high = fold_convert (etype, high);
3893 low = fold_convert (etype, low);
3894 exp = fold_convert (etype, exp);
3895 value = const_binop (MINUS_EXPR, high, low, 0);
3903 if (value != 0 && ! TREE_OVERFLOW (value))
3904 return build_range_check (type,
3905 fold (build2 (MINUS_EXPR, etype, exp, low)),
3906 1, fold_convert (etype, integer_zero_node),
3912 /* Given two ranges, see if we can merge them into one. Return 1 if we
3913 can, 0 if we can't. Set the output range into the specified parameters. */
3916 merge_ranges (int *pin_p, tree *plow, tree *phigh, int in0_p, tree low0,
3917 tree high0, int in1_p, tree low1, tree high1)
3925 int lowequal = ((low0 == 0 && low1 == 0)
3926 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3927 low0, 0, low1, 0)));
3928 int highequal = ((high0 == 0 && high1 == 0)
3929 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3930 high0, 1, high1, 1)));
3932 /* Make range 0 be the range that starts first, or ends last if they
3933 start at the same value. Swap them if it isn't. */
3934 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
3937 && integer_onep (range_binop (GT_EXPR, integer_type_node,
3938 high1, 1, high0, 1))))
3940 temp = in0_p, in0_p = in1_p, in1_p = temp;
3941 tem = low0, low0 = low1, low1 = tem;
3942 tem = high0, high0 = high1, high1 = tem;
3945 /* Now flag two cases, whether the ranges are disjoint or whether the
3946 second range is totally subsumed in the first. Note that the tests
3947 below are simplified by the ones above. */
3948 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
3949 high0, 1, low1, 0));
3950 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
3951 high1, 1, high0, 1));
3953 /* We now have four cases, depending on whether we are including or
3954 excluding the two ranges. */
3957 /* If they don't overlap, the result is false. If the second range
3958 is a subset it is the result. Otherwise, the range is from the start
3959 of the second to the end of the first. */
3961 in_p = 0, low = high = 0;
3963 in_p = 1, low = low1, high = high1;
3965 in_p = 1, low = low1, high = high0;
3968 else if (in0_p && ! in1_p)
3970 /* If they don't overlap, the result is the first range. If they are
3971 equal, the result is false. If the second range is a subset of the
3972 first, and the ranges begin at the same place, we go from just after
3973 the end of the first range to the end of the second. If the second
3974 range is not a subset of the first, or if it is a subset and both
3975 ranges end at the same place, the range starts at the start of the
3976 first range and ends just before the second range.
3977 Otherwise, we can't describe this as a single range. */
3979 in_p = 1, low = low0, high = high0;
3980 else if (lowequal && highequal)
3981 in_p = 0, low = high = 0;
3982 else if (subset && lowequal)
3984 in_p = 1, high = high0;
3985 low = range_binop (PLUS_EXPR, NULL_TREE, high1, 0,
3986 integer_one_node, 0);
3988 else if (! subset || highequal)
3990 in_p = 1, low = low0;
3991 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
3992 integer_one_node, 0);
3998 else if (! in0_p && in1_p)
4000 /* If they don't overlap, the result is the second range. If the second
4001 is a subset of the first, the result is false. Otherwise,
4002 the range starts just after the first range and ends at the
4003 end of the second. */
4005 in_p = 1, low = low1, high = high1;
4006 else if (subset || highequal)
4007 in_p = 0, low = high = 0;
4010 in_p = 1, high = high1;
4011 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
4012 integer_one_node, 0);
4018 /* The case where we are excluding both ranges. Here the complex case
4019 is if they don't overlap. In that case, the only time we have a
4020 range is if they are adjacent. If the second is a subset of the
4021 first, the result is the first. Otherwise, the range to exclude
4022 starts at the beginning of the first range and ends at the end of the
4026 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
4027 range_binop (PLUS_EXPR, NULL_TREE,
4029 integer_one_node, 1),
4031 in_p = 0, low = low0, high = high1;
4034 /* Canonicalize - [min, x] into - [-, x]. */
4035 if (low0 && TREE_CODE (low0) == INTEGER_CST)
4036 switch (TREE_CODE (TREE_TYPE (low0)))
4039 if (TYPE_PRECISION (TREE_TYPE (low0))
4040 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (low0))))
4045 if (tree_int_cst_equal (low0,
4046 TYPE_MIN_VALUE (TREE_TYPE (low0))))
4050 if (TYPE_UNSIGNED (TREE_TYPE (low0))
4051 && integer_zerop (low0))
4058 /* Canonicalize - [x, max] into - [x, -]. */
4059 if (high1 && TREE_CODE (high1) == INTEGER_CST)
4060 switch (TREE_CODE (TREE_TYPE (high1)))
4063 if (TYPE_PRECISION (TREE_TYPE (high1))
4064 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (high1))))
4069 if (tree_int_cst_equal (high1,
4070 TYPE_MAX_VALUE (TREE_TYPE (high1))))
4074 if (TYPE_UNSIGNED (TREE_TYPE (high1))
4075 && integer_zerop (range_binop (PLUS_EXPR, NULL_TREE,
4077 integer_one_node, 1)))
4084 /* The ranges might be also adjacent between the maximum and
4085 minimum values of the given type. For
4086 - [{min,-}, x] and - [y, {max,-}] ranges where x + 1 < y
4087 return + [x + 1, y - 1]. */
4088 if (low0 == 0 && high1 == 0)
4090 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
4091 integer_one_node, 1);
4092 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
4093 integer_one_node, 0);
4094 if (low == 0 || high == 0)
4104 in_p = 0, low = low0, high = high0;
4106 in_p = 0, low = low0, high = high1;
4109 *pin_p = in_p, *plow = low, *phigh = high;
4114 /* Subroutine of fold, looking inside expressions of the form
4115 A op B ? A : C, where ARG0 is A op B and ARG2 is C. This
4116 function is being used also to optimize A op B ? C : A, by
4117 reversing the comparison first.
4119 Return a folded expression whose code is not a COND_EXPR
4120 anymore, or NULL_TREE if no folding opportunity is found. */
4123 fold_cond_expr_with_comparison (tree type, tree arg0, tree arg2)
4125 enum tree_code comp_code = TREE_CODE (arg0);
4126 tree arg00 = TREE_OPERAND (arg0, 0);
4127 tree arg01 = TREE_OPERAND (arg0, 1);
4131 /* If we have A op 0 ? A : -A, consider applying the following
4134 A == 0? A : -A same as -A
4135 A != 0? A : -A same as A
4136 A >= 0? A : -A same as abs (A)
4137 A > 0? A : -A same as abs (A)
4138 A <= 0? A : -A same as -abs (A)
4139 A < 0? A : -A same as -abs (A)
4141 None of these transformations work for modes with signed
4142 zeros. If A is +/-0, the first two transformations will
4143 change the sign of the result (from +0 to -0, or vice
4144 versa). The last four will fix the sign of the result,
4145 even though the original expressions could be positive or
4146 negative, depending on the sign of A.
4148 Note that all these transformations are correct if A is
4149 NaN, since the two alternatives (A and -A) are also NaNs. */
4150 if ((FLOAT_TYPE_P (TREE_TYPE (arg01))
4151 ? real_zerop (arg01)
4152 : integer_zerop (arg01))
4153 && TREE_CODE (arg2) == NEGATE_EXPR
4154 && operand_equal_p (TREE_OPERAND (arg2, 0), arg00, 0))
4158 return fold_convert (type, negate_expr (arg00));
4160 return pedantic_non_lvalue (fold_convert (type, arg00));
4163 if (TYPE_UNSIGNED (TREE_TYPE (arg00)))
4164 arg00 = fold_convert (lang_hooks.types.signed_type
4165 (TREE_TYPE (arg00)), arg00);
4166 tem = fold (build1 (ABS_EXPR, TREE_TYPE (arg00), arg00));
4167 return pedantic_non_lvalue (fold_convert (type, tem));
4170 if (TYPE_UNSIGNED (TREE_TYPE (arg00)))
4171 arg00 = fold_convert (lang_hooks.types.signed_type
4172 (TREE_TYPE (arg00)), arg00);
4173 tem = fold (build1 (ABS_EXPR, TREE_TYPE (arg00), arg00));
4174 return negate_expr (fold_convert (type, tem));
4179 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
4180 A == 0 ? A : 0 is always 0 unless A is -0. Note that
4181 both transformations are correct when A is NaN: A != 0
4182 is then true, and A == 0 is false. */
4184 if (integer_zerop (arg01) && integer_zerop (arg2))
4186 if (comp_code == NE_EXPR)
4187 return pedantic_non_lvalue (fold_convert (type, arg00));
4188 else if (comp_code == EQ_EXPR)
4189 return pedantic_non_lvalue (fold_convert (type, integer_zero_node));
4192 /* Try some transformations of A op B ? A : B.
4194 A == B? A : B same as B
4195 A != B? A : B same as A
4196 A >= B? A : B same as max (A, B)
4197 A > B? A : B same as max (B, A)
4198 A <= B? A : B same as min (A, B)
4199 A < B? A : B same as min (B, A)
4201 As above, these transformations don't work in the presence
4202 of signed zeros. For example, if A and B are zeros of
4203 opposite sign, the first two transformations will change
4204 the sign of the result. In the last four, the original
4205 expressions give different results for (A=+0, B=-0) and
4206 (A=-0, B=+0), but the transformed expressions do not.
4208 The first two transformations are correct if either A or B
4209 is a NaN. In the first transformation, the condition will
4210 be false, and B will indeed be chosen. In the case of the
4211 second transformation, the condition A != B will be true,
4212 and A will be chosen.
4214 The conversions to max() and min() are not correct if B is
4215 a number and A is not. The conditions in the original
4216 expressions will be false, so all four give B. The min()
4217 and max() versions would give a NaN instead. */
4218 if (operand_equal_for_comparison_p (arg01, arg2, arg00))
4220 tree comp_op0 = arg00;
4221 tree comp_op1 = arg01;
4222 tree comp_type = TREE_TYPE (comp_op0);
4224 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
4225 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
4235 return pedantic_non_lvalue (fold_convert (type, arg2));
4237 return pedantic_non_lvalue (fold_convert (type, arg00));
4240 /* In C++ a ?: expression can be an lvalue, so put the
4241 operand which will be used if they are equal first
4242 so that we can convert this back to the
4243 corresponding COND_EXPR. */
4244 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg00))))
4245 return pedantic_non_lvalue (
4246 fold_convert (type, fold (build2 (MIN_EXPR, comp_type,
4247 (comp_code == LE_EXPR
4248 ? comp_op0 : comp_op1),
4249 (comp_code == LE_EXPR
4250 ? comp_op1 : comp_op0)))));
4254 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg00))))
4255 return pedantic_non_lvalue (
4256 fold_convert (type, fold (build2 (MAX_EXPR, comp_type,
4257 (comp_code == GE_EXPR
4258 ? comp_op0 : comp_op1),
4259 (comp_code == GE_EXPR
4260 ? comp_op1 : comp_op0)))));
4267 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
4268 we might still be able to simplify this. For example,
4269 if C1 is one less or one more than C2, this might have started
4270 out as a MIN or MAX and been transformed by this function.
4271 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
4273 if (INTEGRAL_TYPE_P (type)
4274 && TREE_CODE (arg01) == INTEGER_CST
4275 && TREE_CODE (arg2) == INTEGER_CST)
4279 /* We can replace A with C1 in this case. */
4280 arg00 = fold_convert (type, arg01);
4281 return fold (build3 (COND_EXPR, type, arg0, arg00, arg2));
4284 /* If C1 is C2 + 1, this is min(A, C2). */
4285 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
4287 && operand_equal_p (arg01,
4288 const_binop (PLUS_EXPR, arg2,
4289 integer_one_node, 0),
4291 return pedantic_non_lvalue (fold (build2 (MIN_EXPR,
4292 type, arg00, arg2)));
4296 /* If C1 is C2 - 1, this is min(A, C2). */
4297 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
4299 && operand_equal_p (arg01,
4300 const_binop (MINUS_EXPR, arg2,
4301 integer_one_node, 0),
4303 return pedantic_non_lvalue (fold (build2 (MIN_EXPR,
4304 type, arg00, arg2)));
4308 /* If C1 is C2 - 1, this is max(A, C2). */
4309 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
4311 && operand_equal_p (arg01,
4312 const_binop (MINUS_EXPR, arg2,
4313 integer_one_node, 0),
4315 return pedantic_non_lvalue (fold (build2 (MAX_EXPR,
4316 type, arg00, arg2)));
4320 /* If C1 is C2 + 1, this is max(A, C2). */
4321 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
4323 && operand_equal_p (arg01,
4324 const_binop (PLUS_EXPR, arg2,
4325 integer_one_node, 0),
4327 return pedantic_non_lvalue (fold (build2 (MAX_EXPR,
4328 type, arg00, arg2)));
4341 #ifndef RANGE_TEST_NON_SHORT_CIRCUIT
4342 #define RANGE_TEST_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
4345 /* EXP is some logical combination of boolean tests. See if we can
4346 merge it into some range test. Return the new tree if so. */
4349 fold_range_test (tree exp)
4351 int or_op = (TREE_CODE (exp) == TRUTH_ORIF_EXPR
4352 || TREE_CODE (exp) == TRUTH_OR_EXPR);
4353 int in0_p, in1_p, in_p;
4354 tree low0, low1, low, high0, high1, high;
4355 tree lhs = make_range (TREE_OPERAND (exp, 0), &in0_p, &low0, &high0);
4356 tree rhs = make_range (TREE_OPERAND (exp, 1), &in1_p, &low1, &high1);
4359 /* If this is an OR operation, invert both sides; we will invert
4360 again at the end. */
4362 in0_p = ! in0_p, in1_p = ! in1_p;
4364 /* If both expressions are the same, if we can merge the ranges, and we
4365 can build the range test, return it or it inverted. If one of the
4366 ranges is always true or always false, consider it to be the same
4367 expression as the other. */
4368 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
4369 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
4371 && 0 != (tem = (build_range_check (TREE_TYPE (exp),
4373 : rhs != 0 ? rhs : integer_zero_node,
4375 return or_op ? invert_truthvalue (tem) : tem;
4377 /* On machines where the branch cost is expensive, if this is a
4378 short-circuited branch and the underlying object on both sides
4379 is the same, make a non-short-circuit operation. */
4380 else if (RANGE_TEST_NON_SHORT_CIRCUIT
4381 && lhs != 0 && rhs != 0
4382 && (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
4383 || TREE_CODE (exp) == TRUTH_ORIF_EXPR)
4384 && operand_equal_p (lhs, rhs, 0))
4386 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
4387 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
4388 which cases we can't do this. */
4389 if (simple_operand_p (lhs))
4390 return build2 (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
4391 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
4392 TREE_TYPE (exp), TREE_OPERAND (exp, 0),
4393 TREE_OPERAND (exp, 1));
4395 else if (lang_hooks.decls.global_bindings_p () == 0
4396 && ! CONTAINS_PLACEHOLDER_P (lhs))
4398 tree common = save_expr (lhs);
4400 if (0 != (lhs = build_range_check (TREE_TYPE (exp), common,
4401 or_op ? ! in0_p : in0_p,
4403 && (0 != (rhs = build_range_check (TREE_TYPE (exp), common,
4404 or_op ? ! in1_p : in1_p,
4406 return build2 (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
4407 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
4408 TREE_TYPE (exp), lhs, rhs);
4415 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
4416 bit value. Arrange things so the extra bits will be set to zero if and
4417 only if C is signed-extended to its full width. If MASK is nonzero,
4418 it is an INTEGER_CST that should be AND'ed with the extra bits. */
4421 unextend (tree c, int p, int unsignedp, tree mask)
4423 tree type = TREE_TYPE (c);
4424 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
4427 if (p == modesize || unsignedp)
4430 /* We work by getting just the sign bit into the low-order bit, then
4431 into the high-order bit, then sign-extend. We then XOR that value
4433 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
4434 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
4436 /* We must use a signed type in order to get an arithmetic right shift.
4437 However, we must also avoid introducing accidental overflows, so that
4438 a subsequent call to integer_zerop will work. Hence we must
4439 do the type conversion here. At this point, the constant is either
4440 zero or one, and the conversion to a signed type can never overflow.
4441 We could get an overflow if this conversion is done anywhere else. */
4442 if (TYPE_UNSIGNED (type))
4443 temp = fold_convert (lang_hooks.types.signed_type (type), temp);
4445 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
4446 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
4448 temp = const_binop (BIT_AND_EXPR, temp,
4449 fold_convert (TREE_TYPE (c), mask), 0);
4450 /* If necessary, convert the type back to match the type of C. */
4451 if (TYPE_UNSIGNED (type))
4452 temp = fold_convert (type, temp);
4454 return fold_convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
4457 /* Find ways of folding logical expressions of LHS and RHS:
4458 Try to merge two comparisons to the same innermost item.
4459 Look for range tests like "ch >= '0' && ch <= '9'".
4460 Look for combinations of simple terms on machines with expensive branches
4461 and evaluate the RHS unconditionally.
4463 For example, if we have p->a == 2 && p->b == 4 and we can make an
4464 object large enough to span both A and B, we can do this with a comparison
4465 against the object ANDed with the a mask.
4467 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
4468 operations to do this with one comparison.
4470 We check for both normal comparisons and the BIT_AND_EXPRs made this by
4471 function and the one above.
4473 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
4474 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
4476 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
4479 We return the simplified tree or 0 if no optimization is possible. */
4482 fold_truthop (enum tree_code code, tree truth_type, tree lhs, tree rhs)
4484 /* If this is the "or" of two comparisons, we can do something if
4485 the comparisons are NE_EXPR. If this is the "and", we can do something
4486 if the comparisons are EQ_EXPR. I.e.,
4487 (a->b == 2 && a->c == 4) can become (a->new == NEW).
4489 WANTED_CODE is this operation code. For single bit fields, we can
4490 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
4491 comparison for one-bit fields. */
4493 enum tree_code wanted_code;
4494 enum tree_code lcode, rcode;
4495 tree ll_arg, lr_arg, rl_arg, rr_arg;
4496 tree ll_inner, lr_inner, rl_inner, rr_inner;
4497 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
4498 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
4499 HOST_WIDE_INT xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
4500 HOST_WIDE_INT lnbitsize, lnbitpos, rnbitsize, rnbitpos;
4501 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
4502 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
4503 enum machine_mode lnmode, rnmode;
4504 tree ll_mask, lr_mask, rl_mask, rr_mask;
4505 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
4506 tree l_const, r_const;
4507 tree lntype, rntype, result;
4508 int first_bit, end_bit;
4511 /* Start by getting the comparison codes. Fail if anything is volatile.
4512 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
4513 it were surrounded with a NE_EXPR. */
4515 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
4518 lcode = TREE_CODE (lhs);
4519 rcode = TREE_CODE (rhs);
4521 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
4523 lhs = build2 (NE_EXPR, truth_type, lhs, integer_zero_node);
4527 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
4529 rhs = build2 (NE_EXPR, truth_type, rhs, integer_zero_node);
4533 if (TREE_CODE_CLASS (lcode) != '<' || TREE_CODE_CLASS (rcode) != '<')
4536 ll_arg = TREE_OPERAND (lhs, 0);
4537 lr_arg = TREE_OPERAND (lhs, 1);
4538 rl_arg = TREE_OPERAND (rhs, 0);
4539 rr_arg = TREE_OPERAND (rhs, 1);
4541 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
4542 if (simple_operand_p (ll_arg)
4543 && simple_operand_p (lr_arg))
4546 if (operand_equal_p (ll_arg, rl_arg, 0)
4547 && operand_equal_p (lr_arg, rr_arg, 0))
4549 result = combine_comparisons (code, lcode, rcode,
4550 truth_type, ll_arg, lr_arg);
4554 else if (operand_equal_p (ll_arg, rr_arg, 0)
4555 && operand_equal_p (lr_arg, rl_arg, 0))
4557 result = combine_comparisons (code, lcode,
4558 swap_tree_comparison (rcode),
4559 truth_type, ll_arg, lr_arg);
4565 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
4566 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
4568 /* If the RHS can be evaluated unconditionally and its operands are
4569 simple, it wins to evaluate the RHS unconditionally on machines
4570 with expensive branches. In this case, this isn't a comparison
4571 that can be merged. Avoid doing this if the RHS is a floating-point
4572 comparison since those can trap. */
4574 if (BRANCH_COST >= 2
4575 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
4576 && simple_operand_p (rl_arg)
4577 && simple_operand_p (rr_arg))
4579 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
4580 if (code == TRUTH_OR_EXPR
4581 && lcode == NE_EXPR && integer_zerop (lr_arg)
4582 && rcode == NE_EXPR && integer_zerop (rr_arg)
4583 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
4584 return build2 (NE_EXPR, truth_type,
4585 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
4587 fold_convert (TREE_TYPE (ll_arg), integer_zero_node));
4589 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
4590 if (code == TRUTH_AND_EXPR
4591 && lcode == EQ_EXPR && integer_zerop (lr_arg)
4592 && rcode == EQ_EXPR && integer_zerop (rr_arg)
4593 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
4594 return build2 (EQ_EXPR, truth_type,
4595 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
4597 fold_convert (TREE_TYPE (ll_arg), integer_zero_node));
4599 return build2 (code, truth_type, lhs, rhs);
4602 /* See if the comparisons can be merged. Then get all the parameters for
4605 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
4606 || (rcode != EQ_EXPR && rcode != NE_EXPR))
4610 ll_inner = decode_field_reference (ll_arg,
4611 &ll_bitsize, &ll_bitpos, &ll_mode,
4612 &ll_unsignedp, &volatilep, &ll_mask,
4614 lr_inner = decode_field_reference (lr_arg,
4615 &lr_bitsize, &lr_bitpos, &lr_mode,
4616 &lr_unsignedp, &volatilep, &lr_mask,
4618 rl_inner = decode_field_reference (rl_arg,
4619 &rl_bitsize, &rl_bitpos, &rl_mode,
4620 &rl_unsignedp, &volatilep, &rl_mask,
4622 rr_inner = decode_field_reference (rr_arg,
4623 &rr_bitsize, &rr_bitpos, &rr_mode,
4624 &rr_unsignedp, &volatilep, &rr_mask,
4627 /* It must be true that the inner operation on the lhs of each
4628 comparison must be the same if we are to be able to do anything.
4629 Then see if we have constants. If not, the same must be true for
4631 if (volatilep || ll_inner == 0 || rl_inner == 0
4632 || ! operand_equal_p (ll_inner, rl_inner, 0))
4635 if (TREE_CODE (lr_arg) == INTEGER_CST
4636 && TREE_CODE (rr_arg) == INTEGER_CST)
4637 l_const = lr_arg, r_const = rr_arg;
4638 else if (lr_inner == 0 || rr_inner == 0
4639 || ! operand_equal_p (lr_inner, rr_inner, 0))
4642 l_const = r_const = 0;
4644 /* If either comparison code is not correct for our logical operation,
4645 fail. However, we can convert a one-bit comparison against zero into
4646 the opposite comparison against that bit being set in the field. */
4648 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
4649 if (lcode != wanted_code)
4651 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
4653 /* Make the left operand unsigned, since we are only interested
4654 in the value of one bit. Otherwise we are doing the wrong
4663 /* This is analogous to the code for l_const above. */
4664 if (rcode != wanted_code)
4666 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
4675 /* After this point all optimizations will generate bit-field
4676 references, which we might not want. */
4677 if (! lang_hooks.can_use_bit_fields_p ())
4680 /* See if we can find a mode that contains both fields being compared on
4681 the left. If we can't, fail. Otherwise, update all constants and masks
4682 to be relative to a field of that size. */
4683 first_bit = MIN (ll_bitpos, rl_bitpos);
4684 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
4685 lnmode = get_best_mode (end_bit - first_bit, first_bit,
4686 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
4688 if (lnmode == VOIDmode)
4691 lnbitsize = GET_MODE_BITSIZE (lnmode);
4692 lnbitpos = first_bit & ~ (lnbitsize - 1);
4693 lntype = lang_hooks.types.type_for_size (lnbitsize, 1);
4694 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
4696 if (BYTES_BIG_ENDIAN)
4698 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
4699 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
4702 ll_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, ll_mask),
4703 size_int (xll_bitpos), 0);
4704 rl_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, rl_mask),
4705 size_int (xrl_bitpos), 0);
4709 l_const = fold_convert (lntype, l_const);
4710 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
4711 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
4712 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
4713 fold (build1 (BIT_NOT_EXPR,
4717 warning ("comparison is always %d", wanted_code == NE_EXPR);
4719 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
4724 r_const = fold_convert (lntype, r_const);
4725 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
4726 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
4727 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
4728 fold (build1 (BIT_NOT_EXPR,
4732 warning ("comparison is always %d", wanted_code == NE_EXPR);
4734 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
4738 /* If the right sides are not constant, do the same for it. Also,
4739 disallow this optimization if a size or signedness mismatch occurs
4740 between the left and right sides. */
4743 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
4744 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
4745 /* Make sure the two fields on the right
4746 correspond to the left without being swapped. */
4747 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
4750 first_bit = MIN (lr_bitpos, rr_bitpos);
4751 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
4752 rnmode = get_best_mode (end_bit - first_bit, first_bit,
4753 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
4755 if (rnmode == VOIDmode)
4758 rnbitsize = GET_MODE_BITSIZE (rnmode);
4759 rnbitpos = first_bit & ~ (rnbitsize - 1);
4760 rntype = lang_hooks.types.type_for_size (rnbitsize, 1);
4761 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
4763 if (BYTES_BIG_ENDIAN)
4765 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
4766 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
4769 lr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, lr_mask),
4770 size_int (xlr_bitpos), 0);
4771 rr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, rr_mask),
4772 size_int (xrr_bitpos), 0);
4774 /* Make a mask that corresponds to both fields being compared.
4775 Do this for both items being compared. If the operands are the
4776 same size and the bits being compared are in the same position
4777 then we can do this by masking both and comparing the masked
4779 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4780 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
4781 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
4783 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4784 ll_unsignedp || rl_unsignedp);
4785 if (! all_ones_mask_p (ll_mask, lnbitsize))
4786 lhs = build2 (BIT_AND_EXPR, lntype, lhs, ll_mask);
4788 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
4789 lr_unsignedp || rr_unsignedp);
4790 if (! all_ones_mask_p (lr_mask, rnbitsize))
4791 rhs = build2 (BIT_AND_EXPR, rntype, rhs, lr_mask);
4793 return build2 (wanted_code, truth_type, lhs, rhs);
4796 /* There is still another way we can do something: If both pairs of
4797 fields being compared are adjacent, we may be able to make a wider
4798 field containing them both.
4800 Note that we still must mask the lhs/rhs expressions. Furthermore,
4801 the mask must be shifted to account for the shift done by
4802 make_bit_field_ref. */
4803 if ((ll_bitsize + ll_bitpos == rl_bitpos
4804 && lr_bitsize + lr_bitpos == rr_bitpos)
4805 || (ll_bitpos == rl_bitpos + rl_bitsize
4806 && lr_bitpos == rr_bitpos + rr_bitsize))
4810 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
4811 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
4812 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
4813 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
4815 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
4816 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
4817 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
4818 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
4820 /* Convert to the smaller type before masking out unwanted bits. */
4822 if (lntype != rntype)
4824 if (lnbitsize > rnbitsize)
4826 lhs = fold_convert (rntype, lhs);
4827 ll_mask = fold_convert (rntype, ll_mask);
4830 else if (lnbitsize < rnbitsize)
4832 rhs = fold_convert (lntype, rhs);
4833 lr_mask = fold_convert (lntype, lr_mask);
4838 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
4839 lhs = build2 (BIT_AND_EXPR, type, lhs, ll_mask);
4841 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
4842 rhs = build2 (BIT_AND_EXPR, type, rhs, lr_mask);
4844 return build2 (wanted_code, truth_type, lhs, rhs);
4850 /* Handle the case of comparisons with constants. If there is something in
4851 common between the masks, those bits of the constants must be the same.
4852 If not, the condition is always false. Test for this to avoid generating
4853 incorrect code below. */
4854 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
4855 if (! integer_zerop (result)
4856 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
4857 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
4859 if (wanted_code == NE_EXPR)
4861 warning ("`or' of unmatched not-equal tests is always 1");
4862 return constant_boolean_node (true, truth_type);
4866 warning ("`and' of mutually exclusive equal-tests is always 0");
4867 return constant_boolean_node (false, truth_type);
4871 /* Construct the expression we will return. First get the component
4872 reference we will make. Unless the mask is all ones the width of
4873 that field, perform the mask operation. Then compare with the
4875 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4876 ll_unsignedp || rl_unsignedp);
4878 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4879 if (! all_ones_mask_p (ll_mask, lnbitsize))
4880 result = build2 (BIT_AND_EXPR, lntype, result, ll_mask);
4882 return build2 (wanted_code, truth_type, result,
4883 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
4886 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
4890 optimize_minmax_comparison (tree t)
4892 tree type = TREE_TYPE (t);
4893 tree arg0 = TREE_OPERAND (t, 0);
4894 enum tree_code op_code;
4895 tree comp_const = TREE_OPERAND (t, 1);
4897 int consts_equal, consts_lt;
4900 STRIP_SIGN_NOPS (arg0);
4902 op_code = TREE_CODE (arg0);
4903 minmax_const = TREE_OPERAND (arg0, 1);
4904 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
4905 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
4906 inner = TREE_OPERAND (arg0, 0);
4908 /* If something does not permit us to optimize, return the original tree. */
4909 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
4910 || TREE_CODE (comp_const) != INTEGER_CST
4911 || TREE_CONSTANT_OVERFLOW (comp_const)
4912 || TREE_CODE (minmax_const) != INTEGER_CST
4913 || TREE_CONSTANT_OVERFLOW (minmax_const))
4916 /* Now handle all the various comparison codes. We only handle EQ_EXPR
4917 and GT_EXPR, doing the rest with recursive calls using logical
4919 switch (TREE_CODE (t))
4921 case NE_EXPR: case LT_EXPR: case LE_EXPR:
4923 invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t)));
4927 fold (build2 (TRUTH_ORIF_EXPR, type,
4928 optimize_minmax_comparison
4929 (build2 (EQ_EXPR, type, arg0, comp_const)),
4930 optimize_minmax_comparison
4931 (build2 (GT_EXPR, type, arg0, comp_const))));
4934 if (op_code == MAX_EXPR && consts_equal)
4935 /* MAX (X, 0) == 0 -> X <= 0 */
4936 return fold (build2 (LE_EXPR, type, inner, comp_const));
4938 else if (op_code == MAX_EXPR && consts_lt)
4939 /* MAX (X, 0) == 5 -> X == 5 */
4940 return fold (build2 (EQ_EXPR, type, inner, comp_const));
4942 else if (op_code == MAX_EXPR)
4943 /* MAX (X, 0) == -1 -> false */
4944 return omit_one_operand (type, integer_zero_node, inner);
4946 else if (consts_equal)
4947 /* MIN (X, 0) == 0 -> X >= 0 */
4948 return fold (build2 (GE_EXPR, type, inner, comp_const));
4951 /* MIN (X, 0) == 5 -> false */
4952 return omit_one_operand (type, integer_zero_node, inner);
4955 /* MIN (X, 0) == -1 -> X == -1 */
4956 return fold (build2 (EQ_EXPR, type, inner, comp_const));
4959 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
4960 /* MAX (X, 0) > 0 -> X > 0
4961 MAX (X, 0) > 5 -> X > 5 */
4962 return fold (build2 (GT_EXPR, type, inner, comp_const));
4964 else if (op_code == MAX_EXPR)
4965 /* MAX (X, 0) > -1 -> true */
4966 return omit_one_operand (type, integer_one_node, inner);
4968 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
4969 /* MIN (X, 0) > 0 -> false
4970 MIN (X, 0) > 5 -> false */
4971 return omit_one_operand (type, integer_zero_node, inner);
4974 /* MIN (X, 0) > -1 -> X > -1 */
4975 return fold (build2 (GT_EXPR, type, inner, comp_const));
4982 /* T is an integer expression that is being multiplied, divided, or taken a
4983 modulus (CODE says which and what kind of divide or modulus) by a
4984 constant C. See if we can eliminate that operation by folding it with
4985 other operations already in T. WIDE_TYPE, if non-null, is a type that
4986 should be used for the computation if wider than our type.
4988 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
4989 (X * 2) + (Y * 4). We must, however, be assured that either the original
4990 expression would not overflow or that overflow is undefined for the type
4991 in the language in question.
4993 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
4994 the machine has a multiply-accumulate insn or that this is part of an
4995 addressing calculation.
4997 If we return a non-null expression, it is an equivalent form of the
4998 original computation, but need not be in the original type. */
5001 extract_muldiv (tree t, tree c, enum tree_code code, tree wide_type)
5003 /* To avoid exponential search depth, refuse to allow recursion past
5004 three levels. Beyond that (1) it's highly unlikely that we'll find
5005 something interesting and (2) we've probably processed it before
5006 when we built the inner expression. */
5015 ret = extract_muldiv_1 (t, c, code, wide_type);
5022 extract_muldiv_1 (tree t, tree c, enum tree_code code, tree wide_type)
5024 tree type = TREE_TYPE (t);
5025 enum tree_code tcode = TREE_CODE (t);
5026 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
5027 > GET_MODE_SIZE (TYPE_MODE (type)))
5028 ? wide_type : type);
5030 int same_p = tcode == code;
5031 tree op0 = NULL_TREE, op1 = NULL_TREE;
5033 /* Don't deal with constants of zero here; they confuse the code below. */
5034 if (integer_zerop (c))
5037 if (TREE_CODE_CLASS (tcode) == '1')
5038 op0 = TREE_OPERAND (t, 0);
5040 if (TREE_CODE_CLASS (tcode) == '2')
5041 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
5043 /* Note that we need not handle conditional operations here since fold
5044 already handles those cases. So just do arithmetic here. */
5048 /* For a constant, we can always simplify if we are a multiply
5049 or (for divide and modulus) if it is a multiple of our constant. */
5050 if (code == MULT_EXPR
5051 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
5052 return const_binop (code, fold_convert (ctype, t),
5053 fold_convert (ctype, c), 0);
5056 case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
5057 /* If op0 is an expression ... */
5058 if ((TREE_CODE_CLASS (TREE_CODE (op0)) == '<'
5059 || TREE_CODE_CLASS (TREE_CODE (op0)) == '1'
5060 || TREE_CODE_CLASS (TREE_CODE (op0)) == '2'
5061 || TREE_CODE_CLASS (TREE_CODE (op0)) == 'e')
5062 /* ... and is unsigned, and its type is smaller than ctype,
5063 then we cannot pass through as widening. */
5064 && ((TYPE_UNSIGNED (TREE_TYPE (op0))
5065 && ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
5066 && TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
5067 && (GET_MODE_SIZE (TYPE_MODE (ctype))
5068 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
5069 /* ... or its type is larger than ctype,
5070 then we cannot pass through this truncation. */
5071 || (GET_MODE_SIZE (TYPE_MODE (ctype))
5072 < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0))))
5073 /* ... or signedness changes for division or modulus,
5074 then we cannot pass through this conversion. */
5075 || (code != MULT_EXPR
5076 && (TYPE_UNSIGNED (ctype)
5077 != TYPE_UNSIGNED (TREE_TYPE (op0))))))
5080 /* Pass the constant down and see if we can make a simplification. If
5081 we can, replace this expression with the inner simplification for
5082 possible later conversion to our or some other type. */
5083 if ((t2 = fold_convert (TREE_TYPE (op0), c)) != 0
5084 && TREE_CODE (t2) == INTEGER_CST
5085 && ! TREE_CONSTANT_OVERFLOW (t2)
5086 && (0 != (t1 = extract_muldiv (op0, t2, code,
5088 ? ctype : NULL_TREE))))
5092 case NEGATE_EXPR: case ABS_EXPR:
5093 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
5094 return fold (build1 (tcode, ctype, fold_convert (ctype, t1)));
5097 case MIN_EXPR: case MAX_EXPR:
5098 /* If widening the type changes the signedness, then we can't perform
5099 this optimization as that changes the result. */
5100 if (TYPE_UNSIGNED (ctype) != TYPE_UNSIGNED (type))
5103 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
5104 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0
5105 && (t2 = extract_muldiv (op1, c, code, wide_type)) != 0)
5107 if (tree_int_cst_sgn (c) < 0)
5108 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
5110 return fold (build2 (tcode, ctype, fold_convert (ctype, t1),
5111 fold_convert (ctype, t2)));
5115 case LSHIFT_EXPR: case RSHIFT_EXPR:
5116 /* If the second operand is constant, this is a multiplication
5117 or floor division, by a power of two, so we can treat it that
5118 way unless the multiplier or divisor overflows. */
5119 if (TREE_CODE (op1) == INTEGER_CST
5120 /* const_binop may not detect overflow correctly,
5121 so check for it explicitly here. */
5122 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
5123 && TREE_INT_CST_HIGH (op1) == 0
5124 && 0 != (t1 = fold_convert (ctype,
5125 const_binop (LSHIFT_EXPR,
5128 && ! TREE_OVERFLOW (t1))
5129 return extract_muldiv (build2 (tcode == LSHIFT_EXPR
5130 ? MULT_EXPR : FLOOR_DIV_EXPR,
5131 ctype, fold_convert (ctype, op0), t1),
5132 c, code, wide_type);
5135 case PLUS_EXPR: case MINUS_EXPR:
5136 /* See if we can eliminate the operation on both sides. If we can, we
5137 can return a new PLUS or MINUS. If we can't, the only remaining
5138 cases where we can do anything are if the second operand is a
5140 t1 = extract_muldiv (op0, c, code, wide_type);
5141 t2 = extract_muldiv (op1, c, code, wide_type);
5142 if (t1 != 0 && t2 != 0
5143 && (code == MULT_EXPR
5144 /* If not multiplication, we can only do this if both operands
5145 are divisible by c. */
5146 || (multiple_of_p (ctype, op0, c)
5147 && multiple_of_p (ctype, op1, c))))
5148 return fold (build2 (tcode, ctype, fold_convert (ctype, t1),
5149 fold_convert (ctype, t2)));
5151 /* If this was a subtraction, negate OP1 and set it to be an addition.
5152 This simplifies the logic below. */
5153 if (tcode == MINUS_EXPR)
5154 tcode = PLUS_EXPR, op1 = negate_expr (op1);
5156 if (TREE_CODE (op1) != INTEGER_CST)
5159 /* If either OP1 or C are negative, this optimization is not safe for
5160 some of the division and remainder types while for others we need
5161 to change the code. */
5162 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
5164 if (code == CEIL_DIV_EXPR)
5165 code = FLOOR_DIV_EXPR;
5166 else if (code == FLOOR_DIV_EXPR)
5167 code = CEIL_DIV_EXPR;
5168 else if (code != MULT_EXPR
5169 && code != CEIL_MOD_EXPR && code != FLOOR_MOD_EXPR)
5173 /* If it's a multiply or a division/modulus operation of a multiple
5174 of our constant, do the operation and verify it doesn't overflow. */
5175 if (code == MULT_EXPR
5176 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5178 op1 = const_binop (code, fold_convert (ctype, op1),
5179 fold_convert (ctype, c), 0);
5180 /* We allow the constant to overflow with wrapping semantics. */
5182 || (TREE_OVERFLOW (op1) && ! flag_wrapv))
5188 /* If we have an unsigned type is not a sizetype, we cannot widen
5189 the operation since it will change the result if the original
5190 computation overflowed. */
5191 if (TYPE_UNSIGNED (ctype)
5192 && ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
5196 /* If we were able to eliminate our operation from the first side,
5197 apply our operation to the second side and reform the PLUS. */
5198 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
5199 return fold (build2 (tcode, ctype, fold_convert (ctype, t1), op1));
5201 /* The last case is if we are a multiply. In that case, we can
5202 apply the distributive law to commute the multiply and addition
5203 if the multiplication of the constants doesn't overflow. */
5204 if (code == MULT_EXPR)
5205 return fold (build2 (tcode, ctype,
5206 fold (build2 (code, ctype,
5207 fold_convert (ctype, op0),
5208 fold_convert (ctype, c))),
5214 /* We have a special case here if we are doing something like
5215 (C * 8) % 4 since we know that's zero. */
5216 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
5217 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
5218 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
5219 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5220 return omit_one_operand (type, integer_zero_node, op0);
5222 /* ... fall through ... */
5224 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
5225 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
5226 /* If we can extract our operation from the LHS, do so and return a
5227 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
5228 do something only if the second operand is a constant. */
5230 && (t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
5231 return fold (build2 (tcode, ctype, fold_convert (ctype, t1),
5232 fold_convert (ctype, op1)));
5233 else if (tcode == MULT_EXPR && code == MULT_EXPR
5234 && (t1 = extract_muldiv (op1, c, code, wide_type)) != 0)
5235 return fold (build2 (tcode, ctype, fold_convert (ctype, op0),
5236 fold_convert (ctype, t1)));
5237 else if (TREE_CODE (op1) != INTEGER_CST)
5240 /* If these are the same operation types, we can associate them
5241 assuming no overflow. */
5243 && 0 != (t1 = const_binop (MULT_EXPR, fold_convert (ctype, op1),
5244 fold_convert (ctype, c), 0))
5245 && ! TREE_OVERFLOW (t1))
5246 return fold (build2 (tcode, ctype, fold_convert (ctype, op0), t1));
5248 /* If these operations "cancel" each other, we have the main
5249 optimizations of this pass, which occur when either constant is a
5250 multiple of the other, in which case we replace this with either an
5251 operation or CODE or TCODE.
5253 If we have an unsigned type that is not a sizetype, we cannot do
5254 this since it will change the result if the original computation
5256 if ((! TYPE_UNSIGNED (ctype)
5257 || (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
5259 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
5260 || (tcode == MULT_EXPR
5261 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
5262 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR)))
5264 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5265 return fold (build2 (tcode, ctype, fold_convert (ctype, op0),
5266 fold_convert (ctype,
5267 const_binop (TRUNC_DIV_EXPR,
5269 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
5270 return fold (build2 (code, ctype, fold_convert (ctype, op0),
5271 fold_convert (ctype,
5272 const_binop (TRUNC_DIV_EXPR,
5284 /* Return a node which has the indicated constant VALUE (either 0 or
5285 1), and is of the indicated TYPE. */
5288 constant_boolean_node (int value, tree type)
5290 if (type == integer_type_node)
5291 return value ? integer_one_node : integer_zero_node;
5292 else if (type == boolean_type_node)
5293 return value ? boolean_true_node : boolean_false_node;
5294 else if (TREE_CODE (type) == BOOLEAN_TYPE)
5295 return lang_hooks.truthvalue_conversion (value ? integer_one_node
5296 : integer_zero_node);
5299 tree t = build_int_2 (value, 0);
5301 TREE_TYPE (t) = type;
5306 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
5307 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
5308 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
5309 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
5310 COND is the first argument to CODE; otherwise (as in the example
5311 given here), it is the second argument. TYPE is the type of the
5312 original expression. Return NULL_TREE if no simplification is
5316 fold_binary_op_with_conditional_arg (enum tree_code code, tree type,
5317 tree cond, tree arg, int cond_first_p)
5319 tree test, true_value, false_value;
5320 tree lhs = NULL_TREE;
5321 tree rhs = NULL_TREE;
5323 /* This transformation is only worthwhile if we don't have to wrap
5324 arg in a SAVE_EXPR, and the operation can be simplified on atleast
5325 one of the branches once its pushed inside the COND_EXPR. */
5326 if (!TREE_CONSTANT (arg))
5329 if (TREE_CODE (cond) == COND_EXPR)
5331 test = TREE_OPERAND (cond, 0);
5332 true_value = TREE_OPERAND (cond, 1);
5333 false_value = TREE_OPERAND (cond, 2);
5334 /* If this operand throws an expression, then it does not make
5335 sense to try to perform a logical or arithmetic operation
5337 if (VOID_TYPE_P (TREE_TYPE (true_value)))
5339 if (VOID_TYPE_P (TREE_TYPE (false_value)))
5344 tree testtype = TREE_TYPE (cond);
5346 true_value = constant_boolean_node (true, testtype);
5347 false_value = constant_boolean_node (false, testtype);
5351 lhs = fold (cond_first_p ? build2 (code, type, true_value, arg)
5352 : build2 (code, type, arg, true_value));
5354 rhs = fold (cond_first_p ? build2 (code, type, false_value, arg)
5355 : build2 (code, type, arg, false_value));
5357 test = fold (build3 (COND_EXPR, type, test, lhs, rhs));
5358 return fold_convert (type, test);
5362 /* Subroutine of fold() that checks for the addition of +/- 0.0.
5364 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
5365 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
5366 ADDEND is the same as X.
5368 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
5369 and finite. The problematic cases are when X is zero, and its mode
5370 has signed zeros. In the case of rounding towards -infinity,
5371 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
5372 modes, X + 0 is not the same as X because -0 + 0 is 0. */
5375 fold_real_zero_addition_p (tree type, tree addend, int negate)
5377 if (!real_zerop (addend))
5380 /* Don't allow the fold with -fsignaling-nans. */
5381 if (HONOR_SNANS (TYPE_MODE (type)))
5384 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
5385 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
5388 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
5389 if (TREE_CODE (addend) == REAL_CST
5390 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
5393 /* The mode has signed zeros, and we have to honor their sign.
5394 In this situation, there is only one case we can return true for.
5395 X - 0 is the same as X unless rounding towards -infinity is
5397 return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
5400 /* Subroutine of fold() that checks comparisons of built-in math
5401 functions against real constants.
5403 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
5404 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
5405 is the type of the result and ARG0 and ARG1 are the operands of the
5406 comparison. ARG1 must be a TREE_REAL_CST.
5408 The function returns the constant folded tree if a simplification
5409 can be made, and NULL_TREE otherwise. */
5412 fold_mathfn_compare (enum built_in_function fcode, enum tree_code code,
5413 tree type, tree arg0, tree arg1)
5417 if (BUILTIN_SQRT_P (fcode))
5419 tree arg = TREE_VALUE (TREE_OPERAND (arg0, 1));
5420 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg0));
5422 c = TREE_REAL_CST (arg1);
5423 if (REAL_VALUE_NEGATIVE (c))
5425 /* sqrt(x) < y is always false, if y is negative. */
5426 if (code == EQ_EXPR || code == LT_EXPR || code == LE_EXPR)
5427 return omit_one_operand (type, integer_zero_node, arg);
5429 /* sqrt(x) > y is always true, if y is negative and we
5430 don't care about NaNs, i.e. negative values of x. */
5431 if (code == NE_EXPR || !HONOR_NANS (mode))
5432 return omit_one_operand (type, integer_one_node, arg);
5434 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
5435 return fold (build2 (GE_EXPR, type, arg,
5436 build_real (TREE_TYPE (arg), dconst0)));
5438 else if (code == GT_EXPR || code == GE_EXPR)
5442 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
5443 real_convert (&c2, mode, &c2);
5445 if (REAL_VALUE_ISINF (c2))
5447 /* sqrt(x) > y is x == +Inf, when y is very large. */
5448 if (HONOR_INFINITIES (mode))
5449 return fold (build2 (EQ_EXPR, type, arg,
5450 build_real (TREE_TYPE (arg), c2)));
5452 /* sqrt(x) > y is always false, when y is very large
5453 and we don't care about infinities. */
5454 return omit_one_operand (type, integer_zero_node, arg);
5457 /* sqrt(x) > c is the same as x > c*c. */
5458 return fold (build2 (code, type, arg,
5459 build_real (TREE_TYPE (arg), c2)));
5461 else if (code == LT_EXPR || code == LE_EXPR)
5465 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
5466 real_convert (&c2, mode, &c2);
5468 if (REAL_VALUE_ISINF (c2))
5470 /* sqrt(x) < y is always true, when y is a very large
5471 value and we don't care about NaNs or Infinities. */
5472 if (! HONOR_NANS (mode) && ! HONOR_INFINITIES (mode))
5473 return omit_one_operand (type, integer_one_node, arg);
5475 /* sqrt(x) < y is x != +Inf when y is very large and we
5476 don't care about NaNs. */
5477 if (! HONOR_NANS (mode))
5478 return fold (build2 (NE_EXPR, type, arg,
5479 build_real (TREE_TYPE (arg), c2)));
5481 /* sqrt(x) < y is x >= 0 when y is very large and we
5482 don't care about Infinities. */
5483 if (! HONOR_INFINITIES (mode))
5484 return fold (build2 (GE_EXPR, type, arg,
5485 build_real (TREE_TYPE (arg), dconst0)));
5487 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
5488 if (lang_hooks.decls.global_bindings_p () != 0
5489 || CONTAINS_PLACEHOLDER_P (arg))
5492 arg = save_expr (arg);
5493 return fold (build2 (TRUTH_ANDIF_EXPR, type,
5494 fold (build2 (GE_EXPR, type, arg,
5495 build_real (TREE_TYPE (arg),
5497 fold (build2 (NE_EXPR, type, arg,
5498 build_real (TREE_TYPE (arg),
5502 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
5503 if (! HONOR_NANS (mode))
5504 return fold (build2 (code, type, arg,
5505 build_real (TREE_TYPE (arg), c2)));
5507 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
5508 if (lang_hooks.decls.global_bindings_p () == 0
5509 && ! CONTAINS_PLACEHOLDER_P (arg))
5511 arg = save_expr (arg);
5512 return fold (build2 (TRUTH_ANDIF_EXPR, type,
5513 fold (build2 (GE_EXPR, type, arg,
5514 build_real (TREE_TYPE (arg),
5516 fold (build2 (code, type, arg,
5517 build_real (TREE_TYPE (arg),
5526 /* Subroutine of fold() that optimizes comparisons against Infinities,
5527 either +Inf or -Inf.
5529 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
5530 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
5531 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
5533 The function returns the constant folded tree if a simplification
5534 can be made, and NULL_TREE otherwise. */
5537 fold_inf_compare (enum tree_code code, tree type, tree arg0, tree arg1)
5539 enum machine_mode mode;
5540 REAL_VALUE_TYPE max;
5544 mode = TYPE_MODE (TREE_TYPE (arg0));
5546 /* For negative infinity swap the sense of the comparison. */
5547 neg = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1));
5549 code = swap_tree_comparison (code);
5554 /* x > +Inf is always false, if with ignore sNANs. */
5555 if (HONOR_SNANS (mode))
5557 return omit_one_operand (type, integer_zero_node, arg0);
5560 /* x <= +Inf is always true, if we don't case about NaNs. */
5561 if (! HONOR_NANS (mode))
5562 return omit_one_operand (type, integer_one_node, arg0);
5564 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
5565 if (lang_hooks.decls.global_bindings_p () == 0
5566 && ! CONTAINS_PLACEHOLDER_P (arg0))
5568 arg0 = save_expr (arg0);
5569 return fold (build2 (EQ_EXPR, type, arg0, arg0));
5575 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
5576 real_maxval (&max, neg, mode);
5577 return fold (build2 (neg ? LT_EXPR : GT_EXPR, type,
5578 arg0, build_real (TREE_TYPE (arg0), max)));
5581 /* x < +Inf is always equal to x <= DBL_MAX. */
5582 real_maxval (&max, neg, mode);
5583 return fold (build2 (neg ? GE_EXPR : LE_EXPR, type,
5584 arg0, build_real (TREE_TYPE (arg0), max)));
5587 /* x != +Inf is always equal to !(x > DBL_MAX). */
5588 real_maxval (&max, neg, mode);
5589 if (! HONOR_NANS (mode))
5590 return fold (build2 (neg ? GE_EXPR : LE_EXPR, type,
5591 arg0, build_real (TREE_TYPE (arg0), max)));
5593 /* The transformation below creates non-gimple code and thus is
5594 not appropriate if we are in gimple form. */
5598 temp = fold (build2 (neg ? LT_EXPR : GT_EXPR, type,
5599 arg0, build_real (TREE_TYPE (arg0), max)));
5600 return fold (build1 (TRUTH_NOT_EXPR, type, temp));
5609 /* Subroutine of fold() that optimizes comparisons of a division by
5610 a nonzero integer constant against an integer constant, i.e.
5613 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
5614 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
5615 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
5617 The function returns the constant folded tree if a simplification
5618 can be made, and NULL_TREE otherwise. */
5621 fold_div_compare (enum tree_code code, tree type, tree arg0, tree arg1)
5623 tree prod, tmp, hi, lo;
5624 tree arg00 = TREE_OPERAND (arg0, 0);
5625 tree arg01 = TREE_OPERAND (arg0, 1);
5626 unsigned HOST_WIDE_INT lpart;
5627 HOST_WIDE_INT hpart;
5630 /* We have to do this the hard way to detect unsigned overflow.
5631 prod = int_const_binop (MULT_EXPR, arg01, arg1, 0); */
5632 overflow = mul_double (TREE_INT_CST_LOW (arg01),
5633 TREE_INT_CST_HIGH (arg01),
5634 TREE_INT_CST_LOW (arg1),
5635 TREE_INT_CST_HIGH (arg1), &lpart, &hpart);
5636 prod = build_int_2 (lpart, hpart);
5637 TREE_TYPE (prod) = TREE_TYPE (arg00);
5638 TREE_OVERFLOW (prod) = force_fit_type (prod, overflow)
5639 || TREE_INT_CST_HIGH (prod) != hpart
5640 || TREE_INT_CST_LOW (prod) != lpart;
5641 TREE_CONSTANT_OVERFLOW (prod) = TREE_OVERFLOW (prod);
5643 if (TYPE_UNSIGNED (TREE_TYPE (arg0)))
5645 tmp = int_const_binop (MINUS_EXPR, arg01, integer_one_node, 0);
5648 /* Likewise hi = int_const_binop (PLUS_EXPR, prod, tmp, 0). */
5649 overflow = add_double (TREE_INT_CST_LOW (prod),
5650 TREE_INT_CST_HIGH (prod),
5651 TREE_INT_CST_LOW (tmp),
5652 TREE_INT_CST_HIGH (tmp),
5654 hi = build_int_2 (lpart, hpart);
5655 TREE_TYPE (hi) = TREE_TYPE (arg00);
5656 TREE_OVERFLOW (hi) = force_fit_type (hi, overflow)
5657 || TREE_INT_CST_HIGH (hi) != hpart
5658 || TREE_INT_CST_LOW (hi) != lpart
5659 || TREE_OVERFLOW (prod);
5660 TREE_CONSTANT_OVERFLOW (hi) = TREE_OVERFLOW (hi);
5662 else if (tree_int_cst_sgn (arg01) >= 0)
5664 tmp = int_const_binop (MINUS_EXPR, arg01, integer_one_node, 0);
5665 switch (tree_int_cst_sgn (arg1))
5668 lo = int_const_binop (MINUS_EXPR, prod, tmp, 0);
5673 lo = fold_negate_const (tmp, TREE_TYPE (arg0));
5678 hi = int_const_binop (PLUS_EXPR, prod, tmp, 0);
5688 tmp = int_const_binop (PLUS_EXPR, arg01, integer_one_node, 0);
5689 switch (tree_int_cst_sgn (arg1))
5692 hi = int_const_binop (MINUS_EXPR, prod, tmp, 0);
5697 hi = fold_negate_const (tmp, TREE_TYPE (arg0));
5702 lo = int_const_binop (PLUS_EXPR, prod, tmp, 0);
5714 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
5715 return omit_one_operand (type, integer_zero_node, arg00);
5716 if (TREE_OVERFLOW (hi))
5717 return fold (build2 (GE_EXPR, type, arg00, lo));
5718 if (TREE_OVERFLOW (lo))
5719 return fold (build2 (LE_EXPR, type, arg00, hi));
5720 return build_range_check (type, arg00, 1, lo, hi);
5723 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
5724 return omit_one_operand (type, integer_one_node, arg00);
5725 if (TREE_OVERFLOW (hi))
5726 return fold (build2 (LT_EXPR, type, arg00, lo));
5727 if (TREE_OVERFLOW (lo))
5728 return fold (build2 (GT_EXPR, type, arg00, hi));
5729 return build_range_check (type, arg00, 0, lo, hi);
5732 if (TREE_OVERFLOW (lo))
5733 return omit_one_operand (type, integer_zero_node, arg00);
5734 return fold (build2 (LT_EXPR, type, arg00, lo));
5737 if (TREE_OVERFLOW (hi))
5738 return omit_one_operand (type, integer_one_node, arg00);
5739 return fold (build2 (LE_EXPR, type, arg00, hi));
5742 if (TREE_OVERFLOW (hi))
5743 return omit_one_operand (type, integer_zero_node, arg00);
5744 return fold (build2 (GT_EXPR, type, arg00, hi));
5747 if (TREE_OVERFLOW (lo))
5748 return omit_one_operand (type, integer_one_node, arg00);
5749 return fold (build2 (GE_EXPR, type, arg00, lo));
5759 /* If CODE with arguments ARG0 and ARG1 represents a single bit
5760 equality/inequality test, then return a simplified form of
5761 the test using shifts and logical operations. Otherwise return
5762 NULL. TYPE is the desired result type. */
5765 fold_single_bit_test (enum tree_code code, tree arg0, tree arg1,
5768 /* If this is a TRUTH_NOT_EXPR, it may have a single bit test inside
5770 if (code == TRUTH_NOT_EXPR)
5772 code = TREE_CODE (arg0);
5773 if (code != NE_EXPR && code != EQ_EXPR)
5776 /* Extract the arguments of the EQ/NE. */
5777 arg1 = TREE_OPERAND (arg0, 1);
5778 arg0 = TREE_OPERAND (arg0, 0);
5780 /* This requires us to invert the code. */
5781 code = (code == EQ_EXPR ? NE_EXPR : EQ_EXPR);
5784 /* If this is testing a single bit, we can optimize the test. */
5785 if ((code == NE_EXPR || code == EQ_EXPR)
5786 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
5787 && integer_pow2p (TREE_OPERAND (arg0, 1)))
5789 tree inner = TREE_OPERAND (arg0, 0);
5790 tree type = TREE_TYPE (arg0);
5791 int bitnum = tree_log2 (TREE_OPERAND (arg0, 1));
5792 enum machine_mode operand_mode = TYPE_MODE (type);
5794 tree signed_type, unsigned_type, intermediate_type;
5797 /* If we have (A & C) != 0 where C is the sign bit of A, convert
5798 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
5799 arg00 = sign_bit_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
5800 if (arg00 != NULL_TREE
5801 /* This is only a win if casting to a signed type is cheap,
5802 i.e. when arg00's type is not a partial mode. */
5803 && TYPE_PRECISION (TREE_TYPE (arg00))
5804 == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg00))))
5806 tree stype = lang_hooks.types.signed_type (TREE_TYPE (arg00));
5807 return fold (build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
5808 result_type, fold_convert (stype, arg00),
5809 fold_convert (stype, integer_zero_node)));
5812 /* Otherwise we have (A & C) != 0 where C is a single bit,
5813 convert that into ((A >> C2) & 1). Where C2 = log2(C).
5814 Similarly for (A & C) == 0. */
5816 /* If INNER is a right shift of a constant and it plus BITNUM does
5817 not overflow, adjust BITNUM and INNER. */
5818 if (TREE_CODE (inner) == RSHIFT_EXPR
5819 && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST
5820 && TREE_INT_CST_HIGH (TREE_OPERAND (inner, 1)) == 0
5821 && bitnum < TYPE_PRECISION (type)
5822 && 0 > compare_tree_int (TREE_OPERAND (inner, 1),
5823 bitnum - TYPE_PRECISION (type)))
5825 bitnum += TREE_INT_CST_LOW (TREE_OPERAND (inner, 1));
5826 inner = TREE_OPERAND (inner, 0);
5829 /* If we are going to be able to omit the AND below, we must do our
5830 operations as unsigned. If we must use the AND, we have a choice.
5831 Normally unsigned is faster, but for some machines signed is. */
5832 #ifdef LOAD_EXTEND_OP
5833 ops_unsigned = (LOAD_EXTEND_OP (operand_mode) == SIGN_EXTEND ? 0 : 1);
5838 signed_type = lang_hooks.types.type_for_mode (operand_mode, 0);
5839 unsigned_type = lang_hooks.types.type_for_mode (operand_mode, 1);
5840 intermediate_type = ops_unsigned ? unsigned_type : signed_type;
5841 inner = fold_convert (intermediate_type, inner);
5844 inner = build2 (RSHIFT_EXPR, intermediate_type,
5845 inner, size_int (bitnum));
5847 if (code == EQ_EXPR)
5848 inner = build2 (BIT_XOR_EXPR, intermediate_type,
5849 inner, integer_one_node);
5851 /* Put the AND last so it can combine with more things. */
5852 inner = build2 (BIT_AND_EXPR, intermediate_type,
5853 inner, integer_one_node);
5855 /* Make sure to return the proper type. */
5856 inner = fold_convert (result_type, inner);
5863 /* Check whether we are allowed to reorder operands arg0 and arg1,
5864 such that the evaluation of arg1 occurs before arg0. */
5867 reorder_operands_p (tree arg0, tree arg1)
5869 if (! flag_evaluation_order)
5871 if (TREE_CONSTANT (arg0) || TREE_CONSTANT (arg1))
5873 return ! TREE_SIDE_EFFECTS (arg0)
5874 && ! TREE_SIDE_EFFECTS (arg1);
5877 /* Test whether it is preferable two swap two operands, ARG0 and
5878 ARG1, for example because ARG0 is an integer constant and ARG1
5879 isn't. If REORDER is true, only recommend swapping if we can
5880 evaluate the operands in reverse order. */
5883 tree_swap_operands_p (tree arg0, tree arg1, bool reorder)
5885 STRIP_SIGN_NOPS (arg0);
5886 STRIP_SIGN_NOPS (arg1);
5888 if (TREE_CODE (arg1) == INTEGER_CST)
5890 if (TREE_CODE (arg0) == INTEGER_CST)
5893 if (TREE_CODE (arg1) == REAL_CST)
5895 if (TREE_CODE (arg0) == REAL_CST)
5898 if (TREE_CODE (arg1) == COMPLEX_CST)
5900 if (TREE_CODE (arg0) == COMPLEX_CST)
5903 if (TREE_CONSTANT (arg1))
5905 if (TREE_CONSTANT (arg0))
5911 if (reorder && flag_evaluation_order
5912 && (TREE_SIDE_EFFECTS (arg0) || TREE_SIDE_EFFECTS (arg1)))
5920 if (reorder && flag_evaluation_order
5921 && (TREE_SIDE_EFFECTS (arg0) || TREE_SIDE_EFFECTS (arg1)))
5929 /* It is preferable to swap two SSA_NAME to ensure a canonical form
5930 for commutative and comparison operators. Ensuring a canonical
5931 form allows the optimizers to find additional redundancies without
5932 having to explicitly check for both orderings. */
5933 if (TREE_CODE (arg0) == SSA_NAME
5934 && TREE_CODE (arg1) == SSA_NAME
5935 && SSA_NAME_VERSION (arg0) > SSA_NAME_VERSION (arg1))
5941 /* Perform constant folding and related simplification of EXPR.
5942 The related simplifications include x*1 => x, x*0 => 0, etc.,
5943 and application of the associative law.
5944 NOP_EXPR conversions may be removed freely (as long as we
5945 are careful not to change the type of the overall expression).
5946 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
5947 but we can constant-fold them if they have constant operands. */
5949 #ifdef ENABLE_FOLD_CHECKING
5950 # define fold(x) fold_1 (x)
5951 static tree fold_1 (tree);
5957 const tree t = expr;
5958 const tree type = TREE_TYPE (expr);
5959 tree t1 = NULL_TREE;
5961 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
5962 enum tree_code code = TREE_CODE (t);
5963 int kind = TREE_CODE_CLASS (code);
5965 /* WINS will be nonzero when the switch is done
5966 if all operands are constant. */
5969 /* Don't try to process an RTL_EXPR since its operands aren't trees.
5970 Likewise for a SAVE_EXPR that's already been evaluated. */
5971 if (code == RTL_EXPR || (code == SAVE_EXPR && SAVE_EXPR_RTL (t) != 0))
5974 /* Return right away if a constant. */
5978 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
5982 /* Special case for conversion ops that can have fixed point args. */
5983 arg0 = TREE_OPERAND (t, 0);
5985 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
5987 STRIP_SIGN_NOPS (arg0);
5989 if (arg0 != 0 && TREE_CODE (arg0) == COMPLEX_CST)
5990 subop = TREE_REALPART (arg0);
5994 if (subop != 0 && TREE_CODE (subop) != INTEGER_CST
5995 && TREE_CODE (subop) != REAL_CST)
5996 /* Note that TREE_CONSTANT isn't enough:
5997 static var addresses are constant but we can't
5998 do arithmetic on them. */
6001 else if (IS_EXPR_CODE_CLASS (kind))
6003 int len = first_rtl_op (code);
6005 for (i = 0; i < len; i++)
6007 tree op = TREE_OPERAND (t, i);
6011 continue; /* Valid for CALL_EXPR, at least. */
6013 /* Strip any conversions that don't change the mode. This is
6014 safe for every expression, except for a comparison expression
6015 because its signedness is derived from its operands. So, in
6016 the latter case, only strip conversions that don't change the
6019 Note that this is done as an internal manipulation within the
6020 constant folder, in order to find the simplest representation
6021 of the arguments so that their form can be studied. In any
6022 cases, the appropriate type conversions should be put back in
6023 the tree that will get out of the constant folder. */
6025 STRIP_SIGN_NOPS (op);
6029 if (TREE_CODE (op) == COMPLEX_CST)
6030 subop = TREE_REALPART (op);
6034 if (TREE_CODE (subop) != INTEGER_CST
6035 && TREE_CODE (subop) != REAL_CST)
6036 /* Note that TREE_CONSTANT isn't enough:
6037 static var addresses are constant but we can't
6038 do arithmetic on them. */
6048 /* If this is a commutative operation, and ARG0 is a constant, move it
6049 to ARG1 to reduce the number of tests below. */
6050 if (commutative_tree_code (code)
6051 && tree_swap_operands_p (arg0, arg1, true))
6052 return fold (build2 (code, type, TREE_OPERAND (t, 1),
6053 TREE_OPERAND (t, 0)));
6055 /* Now WINS is set as described above,
6056 ARG0 is the first operand of EXPR,
6057 and ARG1 is the second operand (if it has more than one operand).
6059 First check for cases where an arithmetic operation is applied to a
6060 compound, conditional, or comparison operation. Push the arithmetic
6061 operation inside the compound or conditional to see if any folding
6062 can then be done. Convert comparison to conditional for this purpose.
6063 The also optimizes non-constant cases that used to be done in
6066 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
6067 one of the operands is a comparison and the other is a comparison, a
6068 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
6069 code below would make the expression more complex. Change it to a
6070 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
6071 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
6073 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
6074 || code == EQ_EXPR || code == NE_EXPR)
6075 && ((truth_value_p (TREE_CODE (arg0))
6076 && (truth_value_p (TREE_CODE (arg1))
6077 || (TREE_CODE (arg1) == BIT_AND_EXPR
6078 && integer_onep (TREE_OPERAND (arg1, 1)))))
6079 || (truth_value_p (TREE_CODE (arg1))
6080 && (truth_value_p (TREE_CODE (arg0))
6081 || (TREE_CODE (arg0) == BIT_AND_EXPR
6082 && integer_onep (TREE_OPERAND (arg0, 1)))))))
6084 tem = fold (build2 (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
6085 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
6087 type, fold_convert (boolean_type_node, arg0),
6088 fold_convert (boolean_type_node, arg1)));
6090 if (code == EQ_EXPR)
6091 tem = invert_truthvalue (tem);
6096 if (TREE_CODE_CLASS (code) == '1')
6098 if (TREE_CODE (arg0) == COMPOUND_EXPR)
6099 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
6100 fold (build1 (code, type, TREE_OPERAND (arg0, 1))));
6101 else if (TREE_CODE (arg0) == COND_EXPR)
6103 tree arg01 = TREE_OPERAND (arg0, 1);
6104 tree arg02 = TREE_OPERAND (arg0, 2);
6105 if (! VOID_TYPE_P (TREE_TYPE (arg01)))
6106 arg01 = fold (build1 (code, type, arg01));
6107 if (! VOID_TYPE_P (TREE_TYPE (arg02)))
6108 arg02 = fold (build1 (code, type, arg02));
6109 tem = fold (build3 (COND_EXPR, type, TREE_OPERAND (arg0, 0),
6112 /* If this was a conversion, and all we did was to move into
6113 inside the COND_EXPR, bring it back out. But leave it if
6114 it is a conversion from integer to integer and the
6115 result precision is no wider than a word since such a
6116 conversion is cheap and may be optimized away by combine,
6117 while it couldn't if it were outside the COND_EXPR. Then return
6118 so we don't get into an infinite recursion loop taking the
6119 conversion out and then back in. */
6121 if ((code == NOP_EXPR || code == CONVERT_EXPR
6122 || code == NON_LVALUE_EXPR)
6123 && TREE_CODE (tem) == COND_EXPR
6124 && TREE_CODE (TREE_OPERAND (tem, 1)) == code
6125 && TREE_CODE (TREE_OPERAND (tem, 2)) == code
6126 && ! VOID_TYPE_P (TREE_OPERAND (tem, 1))
6127 && ! VOID_TYPE_P (TREE_OPERAND (tem, 2))
6128 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))
6129 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 2), 0)))
6130 && ! (INTEGRAL_TYPE_P (TREE_TYPE (tem))
6132 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))))
6133 && TYPE_PRECISION (TREE_TYPE (tem)) <= BITS_PER_WORD))
6134 tem = build1 (code, type,
6136 TREE_TYPE (TREE_OPERAND
6137 (TREE_OPERAND (tem, 1), 0)),
6138 TREE_OPERAND (tem, 0),
6139 TREE_OPERAND (TREE_OPERAND (tem, 1), 0),
6140 TREE_OPERAND (TREE_OPERAND (tem, 2), 0)));
6143 else if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<')
6145 if (TREE_CODE (type) == BOOLEAN_TYPE)
6147 arg0 = copy_node (arg0);
6148 TREE_TYPE (arg0) = type;
6151 else if (TREE_CODE (type) != INTEGER_TYPE)
6152 return fold (build3 (COND_EXPR, type, arg0,
6153 fold (build1 (code, type,
6155 fold (build1 (code, type,
6156 integer_zero_node))));
6159 else if (TREE_CODE_CLASS (code) == '<'
6160 && TREE_CODE (arg0) == COMPOUND_EXPR)
6161 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
6162 fold (build2 (code, type, TREE_OPERAND (arg0, 1), arg1)));
6163 else if (TREE_CODE_CLASS (code) == '<'
6164 && TREE_CODE (arg1) == COMPOUND_EXPR)
6165 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
6166 fold (build2 (code, type, arg0, TREE_OPERAND (arg1, 1))));
6167 else if (TREE_CODE_CLASS (code) == '2'
6168 || TREE_CODE_CLASS (code) == '<')
6170 if (TREE_CODE (arg0) == COMPOUND_EXPR)
6171 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
6172 fold (build2 (code, type, TREE_OPERAND (arg0, 1),
6174 if (TREE_CODE (arg1) == COMPOUND_EXPR
6175 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
6176 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
6177 fold (build2 (code, type,
6178 arg0, TREE_OPERAND (arg1, 1))));
6180 if (TREE_CODE (arg0) == COND_EXPR
6181 || TREE_CODE_CLASS (TREE_CODE (arg0)) == '<')
6183 tem = fold_binary_op_with_conditional_arg (code, type, arg0, arg1,
6184 /*cond_first_p=*/1);
6185 if (tem != NULL_TREE)
6189 if (TREE_CODE (arg1) == COND_EXPR
6190 || TREE_CODE_CLASS (TREE_CODE (arg1)) == '<')
6192 tem = fold_binary_op_with_conditional_arg (code, type, arg1, arg0,
6193 /*cond_first_p=*/0);
6194 if (tem != NULL_TREE)
6202 return fold (DECL_INITIAL (t));
6207 case FIX_TRUNC_EXPR:
6209 case FIX_FLOOR_EXPR:
6210 case FIX_ROUND_EXPR:
6211 if (TREE_TYPE (TREE_OPERAND (t, 0)) == type)
6212 return TREE_OPERAND (t, 0);
6214 /* Handle cases of two conversions in a row. */
6215 if (TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
6216 || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR)
6218 tree inside_type = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
6219 tree inter_type = TREE_TYPE (TREE_OPERAND (t, 0));
6220 int inside_int = INTEGRAL_TYPE_P (inside_type);
6221 int inside_ptr = POINTER_TYPE_P (inside_type);
6222 int inside_float = FLOAT_TYPE_P (inside_type);
6223 unsigned int inside_prec = TYPE_PRECISION (inside_type);
6224 int inside_unsignedp = TYPE_UNSIGNED (inside_type);
6225 int inter_int = INTEGRAL_TYPE_P (inter_type);
6226 int inter_ptr = POINTER_TYPE_P (inter_type);
6227 int inter_float = FLOAT_TYPE_P (inter_type);
6228 unsigned int inter_prec = TYPE_PRECISION (inter_type);
6229 int inter_unsignedp = TYPE_UNSIGNED (inter_type);
6230 int final_int = INTEGRAL_TYPE_P (type);
6231 int final_ptr = POINTER_TYPE_P (type);
6232 int final_float = FLOAT_TYPE_P (type);
6233 unsigned int final_prec = TYPE_PRECISION (type);
6234 int final_unsignedp = TYPE_UNSIGNED (type);
6236 /* In addition to the cases of two conversions in a row
6237 handled below, if we are converting something to its own
6238 type via an object of identical or wider precision, neither
6239 conversion is needed. */
6240 if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (type)
6241 && ((inter_int && final_int) || (inter_float && final_float))
6242 && inter_prec >= final_prec)
6243 return fold (build1 (code, type,
6244 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
6246 /* Likewise, if the intermediate and final types are either both
6247 float or both integer, we don't need the middle conversion if
6248 it is wider than the final type and doesn't change the signedness
6249 (for integers). Avoid this if the final type is a pointer
6250 since then we sometimes need the inner conversion. Likewise if
6251 the outer has a precision not equal to the size of its mode. */
6252 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
6253 || (inter_float && inside_float))
6254 && inter_prec >= inside_prec
6255 && (inter_float || inter_unsignedp == inside_unsignedp)
6256 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
6257 && TYPE_MODE (type) == TYPE_MODE (inter_type))
6259 return fold (build1 (code, type,
6260 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
6262 /* If we have a sign-extension of a zero-extended value, we can
6263 replace that by a single zero-extension. */
6264 if (inside_int && inter_int && final_int
6265 && inside_prec < inter_prec && inter_prec < final_prec
6266 && inside_unsignedp && !inter_unsignedp)
6267 return fold (build1 (code, type,
6268 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
6270 /* Two conversions in a row are not needed unless:
6271 - some conversion is floating-point (overstrict for now), or
6272 - the intermediate type is narrower than both initial and
6274 - the intermediate type and innermost type differ in signedness,
6275 and the outermost type is wider than the intermediate, or
6276 - the initial type is a pointer type and the precisions of the
6277 intermediate and final types differ, or
6278 - the final type is a pointer type and the precisions of the
6279 initial and intermediate types differ. */
6280 if (! inside_float && ! inter_float && ! final_float
6281 && (inter_prec > inside_prec || inter_prec > final_prec)
6282 && ! (inside_int && inter_int
6283 && inter_unsignedp != inside_unsignedp
6284 && inter_prec < final_prec)
6285 && ((inter_unsignedp && inter_prec > inside_prec)
6286 == (final_unsignedp && final_prec > inter_prec))
6287 && ! (inside_ptr && inter_prec != final_prec)
6288 && ! (final_ptr && inside_prec != inter_prec)
6289 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
6290 && TYPE_MODE (type) == TYPE_MODE (inter_type))
6292 return fold (build1 (code, type,
6293 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
6296 if (TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR
6297 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t, 0), 1))
6298 /* Detect assigning a bitfield. */
6299 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) == COMPONENT_REF
6300 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 1))))
6302 /* Don't leave an assignment inside a conversion
6303 unless assigning a bitfield. */
6304 tree prev = TREE_OPERAND (t, 0);
6305 tem = copy_node (t);
6306 TREE_OPERAND (tem, 0) = TREE_OPERAND (prev, 1);
6307 /* First do the assignment, then return converted constant. */
6308 tem = build2 (COMPOUND_EXPR, TREE_TYPE (tem), prev, fold (tem));
6309 TREE_NO_WARNING (tem) = 1;
6310 TREE_USED (tem) = 1;
6314 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
6315 constants (if x has signed type, the sign bit cannot be set
6316 in c). This folds extension into the BIT_AND_EXPR. */
6317 if (INTEGRAL_TYPE_P (type)
6318 && TREE_CODE (type) != BOOLEAN_TYPE
6319 && TREE_CODE (TREE_OPERAND (t, 0)) == BIT_AND_EXPR
6320 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 1)) == INTEGER_CST)
6322 tree and = TREE_OPERAND (t, 0);
6323 tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
6326 if (TYPE_UNSIGNED (TREE_TYPE (and))
6327 || (TYPE_PRECISION (type)
6328 <= TYPE_PRECISION (TREE_TYPE (and))))
6330 else if (TYPE_PRECISION (TREE_TYPE (and1))
6331 <= HOST_BITS_PER_WIDE_INT
6332 && host_integerp (and1, 1))
6334 unsigned HOST_WIDE_INT cst;
6336 cst = tree_low_cst (and1, 1);
6337 cst &= (HOST_WIDE_INT) -1
6338 << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
6339 change = (cst == 0);
6340 #ifdef LOAD_EXTEND_OP
6342 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
6345 tree uns = lang_hooks.types.unsigned_type (TREE_TYPE (and0));
6346 and0 = fold_convert (uns, and0);
6347 and1 = fold_convert (uns, and1);
6352 return fold (build2 (BIT_AND_EXPR, type,
6353 fold_convert (type, and0),
6354 fold_convert (type, and1)));
6357 /* Convert (T1)((T2)X op Y) into (T1)X op Y, for pointer types T1 and
6358 T2 being pointers to types of the same size. */
6359 if (POINTER_TYPE_P (TREE_TYPE (t))
6360 && TREE_CODE_CLASS (TREE_CODE (arg0)) == '2'
6361 && TREE_CODE (TREE_OPERAND (arg0, 0)) == NOP_EXPR
6362 && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 0))))
6364 tree arg00 = TREE_OPERAND (arg0, 0);
6365 tree t0 = TREE_TYPE (t);
6366 tree t1 = TREE_TYPE (arg00);
6367 tree tt0 = TREE_TYPE (t0);
6368 tree tt1 = TREE_TYPE (t1);
6369 tree s0 = TYPE_SIZE (tt0);
6370 tree s1 = TYPE_SIZE (tt1);
6372 if (s0 && s1 && operand_equal_p (s0, s1, OEP_ONLY_CONST))
6373 return build2 (TREE_CODE (arg0), t0, fold_convert (t0, arg00),
6374 TREE_OPERAND (arg0, 1));
6377 tem = fold_convert_const (code, type, arg0);
6378 return tem ? tem : t;
6380 case VIEW_CONVERT_EXPR:
6381 if (TREE_CODE (TREE_OPERAND (t, 0)) == VIEW_CONVERT_EXPR)
6382 return build1 (VIEW_CONVERT_EXPR, type,
6383 TREE_OPERAND (TREE_OPERAND (t, 0), 0));
6387 if (TREE_CODE (arg0) == CONSTRUCTOR
6388 && ! type_contains_placeholder_p (TREE_TYPE (arg0)))
6390 tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0));
6392 return TREE_VALUE (m);
6397 if (TREE_CONSTANT (t) != wins)
6399 tem = copy_node (t);
6400 TREE_CONSTANT (tem) = wins;
6401 TREE_INVARIANT (tem) = wins;
6407 if (negate_expr_p (arg0))
6408 return fold_convert (type, negate_expr (arg0));
6412 if (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST)
6413 return fold_abs_const (arg0, type);
6414 else if (TREE_CODE (arg0) == NEGATE_EXPR)
6415 return fold (build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0)));
6416 /* Convert fabs((double)float) into (double)fabsf(float). */
6417 else if (TREE_CODE (arg0) == NOP_EXPR
6418 && TREE_CODE (type) == REAL_TYPE)
6420 tree targ0 = strip_float_extensions (arg0);
6422 return fold_convert (type, fold (build1 (ABS_EXPR,
6426 else if (tree_expr_nonnegative_p (arg0))
6431 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
6432 return fold_convert (type, arg0);
6433 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
6434 return build2 (COMPLEX_EXPR, type,
6435 TREE_OPERAND (arg0, 0),
6436 negate_expr (TREE_OPERAND (arg0, 1)));
6437 else if (TREE_CODE (arg0) == COMPLEX_CST)
6438 return build_complex (type, TREE_REALPART (arg0),
6439 negate_expr (TREE_IMAGPART (arg0)));
6440 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
6441 return fold (build2 (TREE_CODE (arg0), type,
6442 fold (build1 (CONJ_EXPR, type,
6443 TREE_OPERAND (arg0, 0))),
6444 fold (build1 (CONJ_EXPR, type,
6445 TREE_OPERAND (arg0, 1)))));
6446 else if (TREE_CODE (arg0) == CONJ_EXPR)
6447 return TREE_OPERAND (arg0, 0);
6451 if (TREE_CODE (arg0) == INTEGER_CST)
6452 return fold_not_const (arg0, type);
6453 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
6454 return TREE_OPERAND (arg0, 0);
6458 /* A + (-B) -> A - B */
6459 if (TREE_CODE (arg1) == NEGATE_EXPR)
6460 return fold (build2 (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
6461 /* (-A) + B -> B - A */
6462 if (TREE_CODE (arg0) == NEGATE_EXPR
6463 && reorder_operands_p (TREE_OPERAND (arg0, 0), arg1))
6464 return fold (build2 (MINUS_EXPR, type, arg1, TREE_OPERAND (arg0, 0)));
6465 if (! FLOAT_TYPE_P (type))
6467 if (integer_zerop (arg1))
6468 return non_lvalue (fold_convert (type, arg0));
6470 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
6471 with a constant, and the two constants have no bits in common,
6472 we should treat this as a BIT_IOR_EXPR since this may produce more
6474 if (TREE_CODE (arg0) == BIT_AND_EXPR
6475 && TREE_CODE (arg1) == BIT_AND_EXPR
6476 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6477 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
6478 && integer_zerop (const_binop (BIT_AND_EXPR,
6479 TREE_OPERAND (arg0, 1),
6480 TREE_OPERAND (arg1, 1), 0)))
6482 code = BIT_IOR_EXPR;
6486 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
6487 (plus (plus (mult) (mult)) (foo)) so that we can
6488 take advantage of the factoring cases below. */
6489 if ((TREE_CODE (arg0) == PLUS_EXPR
6490 && TREE_CODE (arg1) == MULT_EXPR)
6491 || (TREE_CODE (arg1) == PLUS_EXPR
6492 && TREE_CODE (arg0) == MULT_EXPR))
6494 tree parg0, parg1, parg, marg;
6496 if (TREE_CODE (arg0) == PLUS_EXPR)
6497 parg = arg0, marg = arg1;
6499 parg = arg1, marg = arg0;
6500 parg0 = TREE_OPERAND (parg, 0);
6501 parg1 = TREE_OPERAND (parg, 1);
6505 if (TREE_CODE (parg0) == MULT_EXPR
6506 && TREE_CODE (parg1) != MULT_EXPR)
6507 return fold (build2 (PLUS_EXPR, type,
6508 fold (build2 (PLUS_EXPR, type,
6509 fold_convert (type, parg0),
6510 fold_convert (type, marg))),
6511 fold_convert (type, parg1)));
6512 if (TREE_CODE (parg0) != MULT_EXPR
6513 && TREE_CODE (parg1) == MULT_EXPR)
6514 return fold (build2 (PLUS_EXPR, type,
6515 fold (build2 (PLUS_EXPR, type,
6516 fold_convert (type, parg1),
6517 fold_convert (type, marg))),
6518 fold_convert (type, parg0)));
6521 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR)
6523 tree arg00, arg01, arg10, arg11;
6524 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
6526 /* (A * C) + (B * C) -> (A+B) * C.
6527 We are most concerned about the case where C is a constant,
6528 but other combinations show up during loop reduction. Since
6529 it is not difficult, try all four possibilities. */
6531 arg00 = TREE_OPERAND (arg0, 0);
6532 arg01 = TREE_OPERAND (arg0, 1);
6533 arg10 = TREE_OPERAND (arg1, 0);
6534 arg11 = TREE_OPERAND (arg1, 1);
6537 if (operand_equal_p (arg01, arg11, 0))
6538 same = arg01, alt0 = arg00, alt1 = arg10;
6539 else if (operand_equal_p (arg00, arg10, 0))
6540 same = arg00, alt0 = arg01, alt1 = arg11;
6541 else if (operand_equal_p (arg00, arg11, 0))
6542 same = arg00, alt0 = arg01, alt1 = arg10;
6543 else if (operand_equal_p (arg01, arg10, 0))
6544 same = arg01, alt0 = arg00, alt1 = arg11;
6546 /* No identical multiplicands; see if we can find a common
6547 power-of-two factor in non-power-of-two multiplies. This
6548 can help in multi-dimensional array access. */
6549 else if (TREE_CODE (arg01) == INTEGER_CST
6550 && TREE_CODE (arg11) == INTEGER_CST
6551 && TREE_INT_CST_HIGH (arg01) == 0
6552 && TREE_INT_CST_HIGH (arg11) == 0)
6554 HOST_WIDE_INT int01, int11, tmp;
6555 int01 = TREE_INT_CST_LOW (arg01);
6556 int11 = TREE_INT_CST_LOW (arg11);
6558 /* Move min of absolute values to int11. */
6559 if ((int01 >= 0 ? int01 : -int01)
6560 < (int11 >= 0 ? int11 : -int11))
6562 tmp = int01, int01 = int11, int11 = tmp;
6563 alt0 = arg00, arg00 = arg10, arg10 = alt0;
6564 alt0 = arg01, arg01 = arg11, arg11 = alt0;
6567 if (exact_log2 (int11) > 0 && int01 % int11 == 0)
6569 alt0 = fold (build2 (MULT_EXPR, type, arg00,
6570 build_int_2 (int01 / int11, 0)));
6577 return fold (build2 (MULT_EXPR, type,
6578 fold (build2 (PLUS_EXPR, type,
6585 /* See if ARG1 is zero and X + ARG1 reduces to X. */
6586 if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
6587 return non_lvalue (fold_convert (type, arg0));
6589 /* Likewise if the operands are reversed. */
6590 if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
6591 return non_lvalue (fold_convert (type, arg1));
6593 /* Convert x+x into x*2.0. */
6594 if (operand_equal_p (arg0, arg1, 0)
6595 && SCALAR_FLOAT_TYPE_P (type))
6596 return fold (build2 (MULT_EXPR, type, arg0,
6597 build_real (type, dconst2)));
6599 /* Convert x*c+x into x*(c+1). */
6600 if (flag_unsafe_math_optimizations
6601 && TREE_CODE (arg0) == MULT_EXPR
6602 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
6603 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0, 1))
6604 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
6608 c = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
6609 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
6610 return fold (build2 (MULT_EXPR, type, arg1,
6611 build_real (type, c)));
6614 /* Convert x+x*c into x*(c+1). */
6615 if (flag_unsafe_math_optimizations
6616 && TREE_CODE (arg1) == MULT_EXPR
6617 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST
6618 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1, 1))
6619 && operand_equal_p (TREE_OPERAND (arg1, 0), arg0, 0))
6623 c = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
6624 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
6625 return fold (build2 (MULT_EXPR, type, arg0,
6626 build_real (type, c)));
6629 /* Convert x*c1+x*c2 into x*(c1+c2). */
6630 if (flag_unsafe_math_optimizations
6631 && TREE_CODE (arg0) == MULT_EXPR
6632 && TREE_CODE (arg1) == MULT_EXPR
6633 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
6634 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0, 1))
6635 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST
6636 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1, 1))
6637 && operand_equal_p (TREE_OPERAND (arg0, 0),
6638 TREE_OPERAND (arg1, 0), 0))
6640 REAL_VALUE_TYPE c1, c2;
6642 c1 = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
6643 c2 = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
6644 real_arithmetic (&c1, PLUS_EXPR, &c1, &c2);
6645 return fold (build2 (MULT_EXPR, type,
6646 TREE_OPERAND (arg0, 0),
6647 build_real (type, c1)));
6649 /* Convert a + (b*c + d*e) into (a + b*c) + d*e */
6650 if (flag_unsafe_math_optimizations
6651 && TREE_CODE (arg1) == PLUS_EXPR
6652 && TREE_CODE (arg0) != MULT_EXPR)
6654 tree tree10 = TREE_OPERAND (arg1, 0);
6655 tree tree11 = TREE_OPERAND (arg1, 1);
6656 if (TREE_CODE (tree11) == MULT_EXPR
6657 && TREE_CODE (tree10) == MULT_EXPR)
6660 tree0 = fold (build2 (PLUS_EXPR, type, arg0, tree10));
6661 return fold (build2 (PLUS_EXPR, type, tree0, tree11));
6664 /* Convert (b*c + d*e) + a into b*c + (d*e +a) */
6665 if (flag_unsafe_math_optimizations
6666 && TREE_CODE (arg0) == PLUS_EXPR
6667 && TREE_CODE (arg1) != MULT_EXPR)
6669 tree tree00 = TREE_OPERAND (arg0, 0);
6670 tree tree01 = TREE_OPERAND (arg0, 1);
6671 if (TREE_CODE (tree01) == MULT_EXPR
6672 && TREE_CODE (tree00) == MULT_EXPR)
6675 tree0 = fold (build2 (PLUS_EXPR, type, tree01, arg1));
6676 return fold (build2 (PLUS_EXPR, type, tree00, tree0));
6682 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
6683 is a rotate of A by C1 bits. */
6684 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
6685 is a rotate of A by B bits. */
6687 enum tree_code code0, code1;
6688 code0 = TREE_CODE (arg0);
6689 code1 = TREE_CODE (arg1);
6690 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
6691 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
6692 && operand_equal_p (TREE_OPERAND (arg0, 0),
6693 TREE_OPERAND (arg1, 0), 0)
6694 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
6696 tree tree01, tree11;
6697 enum tree_code code01, code11;
6699 tree01 = TREE_OPERAND (arg0, 1);
6700 tree11 = TREE_OPERAND (arg1, 1);
6701 STRIP_NOPS (tree01);
6702 STRIP_NOPS (tree11);
6703 code01 = TREE_CODE (tree01);
6704 code11 = TREE_CODE (tree11);
6705 if (code01 == INTEGER_CST
6706 && code11 == INTEGER_CST
6707 && TREE_INT_CST_HIGH (tree01) == 0
6708 && TREE_INT_CST_HIGH (tree11) == 0
6709 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
6710 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
6711 return build2 (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
6712 code0 == LSHIFT_EXPR ? tree01 : tree11);
6713 else if (code11 == MINUS_EXPR)
6715 tree tree110, tree111;
6716 tree110 = TREE_OPERAND (tree11, 0);
6717 tree111 = TREE_OPERAND (tree11, 1);
6718 STRIP_NOPS (tree110);
6719 STRIP_NOPS (tree111);
6720 if (TREE_CODE (tree110) == INTEGER_CST
6721 && 0 == compare_tree_int (tree110,
6723 (TREE_TYPE (TREE_OPERAND
6725 && operand_equal_p (tree01, tree111, 0))
6726 return build2 ((code0 == LSHIFT_EXPR
6729 type, TREE_OPERAND (arg0, 0), tree01);
6731 else if (code01 == MINUS_EXPR)
6733 tree tree010, tree011;
6734 tree010 = TREE_OPERAND (tree01, 0);
6735 tree011 = TREE_OPERAND (tree01, 1);
6736 STRIP_NOPS (tree010);
6737 STRIP_NOPS (tree011);
6738 if (TREE_CODE (tree010) == INTEGER_CST
6739 && 0 == compare_tree_int (tree010,
6741 (TREE_TYPE (TREE_OPERAND
6743 && operand_equal_p (tree11, tree011, 0))
6744 return build2 ((code0 != LSHIFT_EXPR
6747 type, TREE_OPERAND (arg0, 0), tree11);
6753 /* In most languages, can't associate operations on floats through
6754 parentheses. Rather than remember where the parentheses were, we
6755 don't associate floats at all, unless the user has specified
6756 -funsafe-math-optimizations. */
6759 && (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
6761 tree var0, con0, lit0, minus_lit0;
6762 tree var1, con1, lit1, minus_lit1;
6764 /* Split both trees into variables, constants, and literals. Then
6765 associate each group together, the constants with literals,
6766 then the result with variables. This increases the chances of
6767 literals being recombined later and of generating relocatable
6768 expressions for the sum of a constant and literal. */
6769 var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
6770 var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
6771 code == MINUS_EXPR);
6773 /* Only do something if we found more than two objects. Otherwise,
6774 nothing has changed and we risk infinite recursion. */
6775 if (2 < ((var0 != 0) + (var1 != 0)
6776 + (con0 != 0) + (con1 != 0)
6777 + (lit0 != 0) + (lit1 != 0)
6778 + (minus_lit0 != 0) + (minus_lit1 != 0)))
6780 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
6781 if (code == MINUS_EXPR)
6784 var0 = associate_trees (var0, var1, code, type);
6785 con0 = associate_trees (con0, con1, code, type);
6786 lit0 = associate_trees (lit0, lit1, code, type);
6787 minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
6789 /* Preserve the MINUS_EXPR if the negative part of the literal is
6790 greater than the positive part. Otherwise, the multiplicative
6791 folding code (i.e extract_muldiv) may be fooled in case
6792 unsigned constants are subtracted, like in the following
6793 example: ((X*2 + 4) - 8U)/2. */
6794 if (minus_lit0 && lit0)
6796 if (TREE_CODE (lit0) == INTEGER_CST
6797 && TREE_CODE (minus_lit0) == INTEGER_CST
6798 && tree_int_cst_lt (lit0, minus_lit0))
6800 minus_lit0 = associate_trees (minus_lit0, lit0,
6806 lit0 = associate_trees (lit0, minus_lit0,
6814 return fold_convert (type,
6815 associate_trees (var0, minus_lit0,
6819 con0 = associate_trees (con0, minus_lit0,
6821 return fold_convert (type,
6822 associate_trees (var0, con0,
6827 con0 = associate_trees (con0, lit0, code, type);
6828 return fold_convert (type, associate_trees (var0, con0,
6835 t1 = const_binop (code, arg0, arg1, 0);
6836 if (t1 != NULL_TREE)
6838 /* The return value should always have
6839 the same type as the original expression. */
6840 if (TREE_TYPE (t1) != type)
6841 t1 = fold_convert (type, t1);
6848 /* A - (-B) -> A + B */
6849 if (TREE_CODE (arg1) == NEGATE_EXPR)
6850 return fold (build2 (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
6851 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
6852 if (TREE_CODE (arg0) == NEGATE_EXPR
6853 && (FLOAT_TYPE_P (type)
6854 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv))
6855 && negate_expr_p (arg1)
6856 && reorder_operands_p (arg0, arg1))
6857 return fold (build2 (MINUS_EXPR, type, negate_expr (arg1),
6858 TREE_OPERAND (arg0, 0)));
6860 if (! FLOAT_TYPE_P (type))
6862 if (! wins && integer_zerop (arg0))
6863 return negate_expr (fold_convert (type, arg1));
6864 if (integer_zerop (arg1))
6865 return non_lvalue (fold_convert (type, arg0));
6867 /* Fold A - (A & B) into ~B & A. */
6868 if (!TREE_SIDE_EFFECTS (arg0)
6869 && TREE_CODE (arg1) == BIT_AND_EXPR)
6871 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
6872 return fold (build2 (BIT_AND_EXPR, type,
6873 fold (build1 (BIT_NOT_EXPR, type,
6874 TREE_OPERAND (arg1, 0))),
6876 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
6877 return fold (build2 (BIT_AND_EXPR, type,
6878 fold (build1 (BIT_NOT_EXPR, type,
6879 TREE_OPERAND (arg1, 1))),
6883 /* Fold (A & ~B) - (A & B) into (A ^ B) - B, where B is
6884 any power of 2 minus 1. */
6885 if (TREE_CODE (arg0) == BIT_AND_EXPR
6886 && TREE_CODE (arg1) == BIT_AND_EXPR
6887 && operand_equal_p (TREE_OPERAND (arg0, 0),
6888 TREE_OPERAND (arg1, 0), 0))
6890 tree mask0 = TREE_OPERAND (arg0, 1);
6891 tree mask1 = TREE_OPERAND (arg1, 1);
6892 tree tem = fold (build1 (BIT_NOT_EXPR, type, mask0));
6894 if (operand_equal_p (tem, mask1, 0))
6896 tem = fold (build2 (BIT_XOR_EXPR, type,
6897 TREE_OPERAND (arg0, 0), mask1));
6898 return fold (build2 (MINUS_EXPR, type, tem, mask1));
6903 /* See if ARG1 is zero and X - ARG1 reduces to X. */
6904 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
6905 return non_lvalue (fold_convert (type, arg0));
6907 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
6908 ARG0 is zero and X + ARG0 reduces to X, since that would mean
6909 (-ARG1 + ARG0) reduces to -ARG1. */
6910 else if (!wins && fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
6911 return negate_expr (fold_convert (type, arg1));
6913 /* Fold &x - &x. This can happen from &x.foo - &x.
6914 This is unsafe for certain floats even in non-IEEE formats.
6915 In IEEE, it is unsafe because it does wrong for NaNs.
6916 Also note that operand_equal_p is always false if an operand
6919 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
6920 && operand_equal_p (arg0, arg1, 0))
6921 return fold_convert (type, integer_zero_node);
6923 /* A - B -> A + (-B) if B is easily negatable. */
6924 if (!wins && negate_expr_p (arg1)
6925 && (FLOAT_TYPE_P (type)
6926 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv)))
6927 return fold (build2 (PLUS_EXPR, type, arg0, negate_expr (arg1)));
6929 if (TREE_CODE (arg0) == MULT_EXPR
6930 && TREE_CODE (arg1) == MULT_EXPR
6931 && (INTEGRAL_TYPE_P (type) || flag_unsafe_math_optimizations))
6933 /* (A * C) - (B * C) -> (A-B) * C. */
6934 if (operand_equal_p (TREE_OPERAND (arg0, 1),
6935 TREE_OPERAND (arg1, 1), 0))
6936 return fold (build2 (MULT_EXPR, type,
6937 fold (build2 (MINUS_EXPR, type,
6938 TREE_OPERAND (arg0, 0),
6939 TREE_OPERAND (arg1, 0))),
6940 TREE_OPERAND (arg0, 1)));
6941 /* (A * C1) - (A * C2) -> A * (C1-C2). */
6942 if (operand_equal_p (TREE_OPERAND (arg0, 0),
6943 TREE_OPERAND (arg1, 0), 0))
6944 return fold (build2 (MULT_EXPR, type,
6945 TREE_OPERAND (arg0, 0),
6946 fold (build2 (MINUS_EXPR, type,
6947 TREE_OPERAND (arg0, 1),
6948 TREE_OPERAND (arg1, 1)))));
6954 /* (-A) * (-B) -> A * B */
6955 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
6956 return fold (build2 (MULT_EXPR, type,
6957 TREE_OPERAND (arg0, 0),
6958 negate_expr (arg1)));
6959 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
6960 return fold (build2 (MULT_EXPR, type,
6962 TREE_OPERAND (arg1, 0)));
6964 if (! FLOAT_TYPE_P (type))
6966 if (integer_zerop (arg1))
6967 return omit_one_operand (type, arg1, arg0);
6968 if (integer_onep (arg1))
6969 return non_lvalue (fold_convert (type, arg0));
6971 /* (a * (1 << b)) is (a << b) */
6972 if (TREE_CODE (arg1) == LSHIFT_EXPR
6973 && integer_onep (TREE_OPERAND (arg1, 0)))
6974 return fold (build2 (LSHIFT_EXPR, type, arg0,
6975 TREE_OPERAND (arg1, 1)));
6976 if (TREE_CODE (arg0) == LSHIFT_EXPR
6977 && integer_onep (TREE_OPERAND (arg0, 0)))
6978 return fold (build2 (LSHIFT_EXPR, type, arg1,
6979 TREE_OPERAND (arg0, 1)));
6981 if (TREE_CODE (arg1) == INTEGER_CST
6982 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0),
6983 fold_convert (type, arg1),
6985 return fold_convert (type, tem);
6990 /* Maybe fold x * 0 to 0. The expressions aren't the same
6991 when x is NaN, since x * 0 is also NaN. Nor are they the
6992 same in modes with signed zeros, since multiplying a
6993 negative value by 0 gives -0, not +0. */
6994 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
6995 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
6996 && real_zerop (arg1))
6997 return omit_one_operand (type, arg1, arg0);
6998 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
6999 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
7000 && real_onep (arg1))
7001 return non_lvalue (fold_convert (type, arg0));
7003 /* Transform x * -1.0 into -x. */
7004 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
7005 && real_minus_onep (arg1))
7006 return fold_convert (type, negate_expr (arg0));
7008 /* Convert (C1/X)*C2 into (C1*C2)/X. */
7009 if (flag_unsafe_math_optimizations
7010 && TREE_CODE (arg0) == RDIV_EXPR
7011 && TREE_CODE (arg1) == REAL_CST
7012 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST)
7014 tree tem = const_binop (MULT_EXPR, TREE_OPERAND (arg0, 0),
7017 return fold (build2 (RDIV_EXPR, type, tem,
7018 TREE_OPERAND (arg0, 1)));
7021 if (flag_unsafe_math_optimizations)
7023 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
7024 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
7026 /* Optimizations of root(...)*root(...). */
7027 if (fcode0 == fcode1 && BUILTIN_ROOT_P (fcode0))
7029 tree rootfn, arg, arglist;
7030 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
7031 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
7033 /* Optimize sqrt(x)*sqrt(x) as x. */
7034 if (BUILTIN_SQRT_P (fcode0)
7035 && operand_equal_p (arg00, arg10, 0)
7036 && ! HONOR_SNANS (TYPE_MODE (type)))
7039 /* Optimize root(x)*root(y) as root(x*y). */
7040 rootfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7041 arg = fold (build2 (MULT_EXPR, type, arg00, arg10));
7042 arglist = build_tree_list (NULL_TREE, arg);
7043 return build_function_call_expr (rootfn, arglist);
7046 /* Optimize expN(x)*expN(y) as expN(x+y). */
7047 if (fcode0 == fcode1 && BUILTIN_EXPONENT_P (fcode0))
7049 tree expfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7050 tree arg = build2 (PLUS_EXPR, type,
7051 TREE_VALUE (TREE_OPERAND (arg0, 1)),
7052 TREE_VALUE (TREE_OPERAND (arg1, 1)));
7053 tree arglist = build_tree_list (NULL_TREE, fold (arg));
7054 return build_function_call_expr (expfn, arglist);
7057 /* Optimizations of pow(...)*pow(...). */
7058 if ((fcode0 == BUILT_IN_POW && fcode1 == BUILT_IN_POW)
7059 || (fcode0 == BUILT_IN_POWF && fcode1 == BUILT_IN_POWF)
7060 || (fcode0 == BUILT_IN_POWL && fcode1 == BUILT_IN_POWL))
7062 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
7063 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
7065 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
7066 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
7069 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
7070 if (operand_equal_p (arg01, arg11, 0))
7072 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7073 tree arg = build2 (MULT_EXPR, type, arg00, arg10);
7074 tree arglist = tree_cons (NULL_TREE, fold (arg),
7075 build_tree_list (NULL_TREE,
7077 return build_function_call_expr (powfn, arglist);
7080 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
7081 if (operand_equal_p (arg00, arg10, 0))
7083 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7084 tree arg = fold (build2 (PLUS_EXPR, type, arg01, arg11));
7085 tree arglist = tree_cons (NULL_TREE, arg00,
7086 build_tree_list (NULL_TREE,
7088 return build_function_call_expr (powfn, arglist);
7092 /* Optimize tan(x)*cos(x) as sin(x). */
7093 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_COS)
7094 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_COSF)
7095 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_COSL)
7096 || (fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_TAN)
7097 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_TANF)
7098 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_TANL))
7099 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
7100 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
7102 tree sinfn = mathfn_built_in (type, BUILT_IN_SIN);
7104 if (sinfn != NULL_TREE)
7105 return build_function_call_expr (sinfn,
7106 TREE_OPERAND (arg0, 1));
7109 /* Optimize x*pow(x,c) as pow(x,c+1). */
7110 if (fcode1 == BUILT_IN_POW
7111 || fcode1 == BUILT_IN_POWF
7112 || fcode1 == BUILT_IN_POWL)
7114 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
7115 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
7117 if (TREE_CODE (arg11) == REAL_CST
7118 && ! TREE_CONSTANT_OVERFLOW (arg11)
7119 && operand_equal_p (arg0, arg10, 0))
7121 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
7125 c = TREE_REAL_CST (arg11);
7126 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
7127 arg = build_real (type, c);
7128 arglist = build_tree_list (NULL_TREE, arg);
7129 arglist = tree_cons (NULL_TREE, arg0, arglist);
7130 return build_function_call_expr (powfn, arglist);
7134 /* Optimize pow(x,c)*x as pow(x,c+1). */
7135 if (fcode0 == BUILT_IN_POW
7136 || fcode0 == BUILT_IN_POWF
7137 || fcode0 == BUILT_IN_POWL)
7139 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
7140 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
7142 if (TREE_CODE (arg01) == REAL_CST
7143 && ! TREE_CONSTANT_OVERFLOW (arg01)
7144 && operand_equal_p (arg1, arg00, 0))
7146 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7150 c = TREE_REAL_CST (arg01);
7151 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
7152 arg = build_real (type, c);
7153 arglist = build_tree_list (NULL_TREE, arg);
7154 arglist = tree_cons (NULL_TREE, arg1, arglist);
7155 return build_function_call_expr (powfn, arglist);
7159 /* Optimize x*x as pow(x,2.0), which is expanded as x*x. */
7161 && operand_equal_p (arg0, arg1, 0))
7163 tree powfn = mathfn_built_in (type, BUILT_IN_POW);
7167 tree arg = build_real (type, dconst2);
7168 tree arglist = build_tree_list (NULL_TREE, arg);
7169 arglist = tree_cons (NULL_TREE, arg0, arglist);
7170 return build_function_call_expr (powfn, arglist);
7179 if (integer_all_onesp (arg1))
7180 return omit_one_operand (type, arg1, arg0);
7181 if (integer_zerop (arg1))
7182 return non_lvalue (fold_convert (type, arg0));
7183 if (operand_equal_p (arg0, arg1, 0))
7184 return non_lvalue (fold_convert (type, arg0));
7185 t1 = distribute_bit_expr (code, type, arg0, arg1);
7186 if (t1 != NULL_TREE)
7189 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
7191 This results in more efficient code for machines without a NAND
7192 instruction. Combine will canonicalize to the first form
7193 which will allow use of NAND instructions provided by the
7194 backend if they exist. */
7195 if (TREE_CODE (arg0) == BIT_NOT_EXPR
7196 && TREE_CODE (arg1) == BIT_NOT_EXPR)
7198 return fold (build1 (BIT_NOT_EXPR, type,
7199 build2 (BIT_AND_EXPR, type,
7200 TREE_OPERAND (arg0, 0),
7201 TREE_OPERAND (arg1, 0))));
7204 /* See if this can be simplified into a rotate first. If that
7205 is unsuccessful continue in the association code. */
7209 if (integer_zerop (arg1))
7210 return non_lvalue (fold_convert (type, arg0));
7211 if (integer_all_onesp (arg1))
7212 return fold (build1 (BIT_NOT_EXPR, type, arg0));
7213 if (operand_equal_p (arg0, arg1, 0))
7214 return omit_one_operand (type, integer_zero_node, arg0);
7216 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
7217 with a constant, and the two constants have no bits in common,
7218 we should treat this as a BIT_IOR_EXPR since this may produce more
7220 if (TREE_CODE (arg0) == BIT_AND_EXPR
7221 && TREE_CODE (arg1) == BIT_AND_EXPR
7222 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7223 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
7224 && integer_zerop (const_binop (BIT_AND_EXPR,
7225 TREE_OPERAND (arg0, 1),
7226 TREE_OPERAND (arg1, 1), 0)))
7228 code = BIT_IOR_EXPR;
7232 /* See if this can be simplified into a rotate first. If that
7233 is unsuccessful continue in the association code. */
7237 if (integer_all_onesp (arg1))
7238 return non_lvalue (fold_convert (type, arg0));
7239 if (integer_zerop (arg1))
7240 return omit_one_operand (type, arg1, arg0);
7241 if (operand_equal_p (arg0, arg1, 0))
7242 return non_lvalue (fold_convert (type, arg0));
7243 t1 = distribute_bit_expr (code, type, arg0, arg1);
7244 if (t1 != NULL_TREE)
7246 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
7247 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
7248 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
7251 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
7253 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
7254 && (~TREE_INT_CST_LOW (arg1)
7255 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
7256 return fold_convert (type, TREE_OPERAND (arg0, 0));
7259 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
7261 This results in more efficient code for machines without a NOR
7262 instruction. Combine will canonicalize to the first form
7263 which will allow use of NOR instructions provided by the
7264 backend if they exist. */
7265 if (TREE_CODE (arg0) == BIT_NOT_EXPR
7266 && TREE_CODE (arg1) == BIT_NOT_EXPR)
7268 return fold (build1 (BIT_NOT_EXPR, type,
7269 build2 (BIT_IOR_EXPR, type,
7270 TREE_OPERAND (arg0, 0),
7271 TREE_OPERAND (arg1, 0))));
7277 /* Don't touch a floating-point divide by zero unless the mode
7278 of the constant can represent infinity. */
7279 if (TREE_CODE (arg1) == REAL_CST
7280 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
7281 && real_zerop (arg1))
7284 /* (-A) / (-B) -> A / B */
7285 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
7286 return fold (build2 (RDIV_EXPR, type,
7287 TREE_OPERAND (arg0, 0),
7288 negate_expr (arg1)));
7289 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
7290 return fold (build2 (RDIV_EXPR, type,
7292 TREE_OPERAND (arg1, 0)));
7294 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
7295 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
7296 && real_onep (arg1))
7297 return non_lvalue (fold_convert (type, arg0));
7299 /* In IEEE floating point, x/-1 is not equivalent to -x for snans. */
7300 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
7301 && real_minus_onep (arg1))
7302 return non_lvalue (fold_convert (type, negate_expr (arg0)));
7304 /* If ARG1 is a constant, we can convert this to a multiply by the
7305 reciprocal. This does not have the same rounding properties,
7306 so only do this if -funsafe-math-optimizations. We can actually
7307 always safely do it if ARG1 is a power of two, but it's hard to
7308 tell if it is or not in a portable manner. */
7309 if (TREE_CODE (arg1) == REAL_CST)
7311 if (flag_unsafe_math_optimizations
7312 && 0 != (tem = const_binop (code, build_real (type, dconst1),
7314 return fold (build2 (MULT_EXPR, type, arg0, tem));
7315 /* Find the reciprocal if optimizing and the result is exact. */
7319 r = TREE_REAL_CST (arg1);
7320 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
7322 tem = build_real (type, r);
7323 return fold (build2 (MULT_EXPR, type, arg0, tem));
7327 /* Convert A/B/C to A/(B*C). */
7328 if (flag_unsafe_math_optimizations
7329 && TREE_CODE (arg0) == RDIV_EXPR)
7330 return fold (build2 (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
7331 fold (build2 (MULT_EXPR, type,
7332 TREE_OPERAND (arg0, 1), arg1))));
7334 /* Convert A/(B/C) to (A/B)*C. */
7335 if (flag_unsafe_math_optimizations
7336 && TREE_CODE (arg1) == RDIV_EXPR)
7337 return fold (build2 (MULT_EXPR, type,
7338 fold (build2 (RDIV_EXPR, type, arg0,
7339 TREE_OPERAND (arg1, 0))),
7340 TREE_OPERAND (arg1, 1)));
7342 /* Convert C1/(X*C2) into (C1/C2)/X. */
7343 if (flag_unsafe_math_optimizations
7344 && TREE_CODE (arg1) == MULT_EXPR
7345 && TREE_CODE (arg0) == REAL_CST
7346 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
7348 tree tem = const_binop (RDIV_EXPR, arg0,
7349 TREE_OPERAND (arg1, 1), 0);
7351 return fold (build2 (RDIV_EXPR, type, tem,
7352 TREE_OPERAND (arg1, 0)));
7355 if (flag_unsafe_math_optimizations)
7357 enum built_in_function fcode = builtin_mathfn_code (arg1);
7358 /* Optimize x/expN(y) into x*expN(-y). */
7359 if (BUILTIN_EXPONENT_P (fcode))
7361 tree expfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
7362 tree arg = negate_expr (TREE_VALUE (TREE_OPERAND (arg1, 1)));
7363 tree arglist = build_tree_list (NULL_TREE,
7364 fold_convert (type, arg));
7365 arg1 = build_function_call_expr (expfn, arglist);
7366 return fold (build2 (MULT_EXPR, type, arg0, arg1));
7369 /* Optimize x/pow(y,z) into x*pow(y,-z). */
7370 if (fcode == BUILT_IN_POW
7371 || fcode == BUILT_IN_POWF
7372 || fcode == BUILT_IN_POWL)
7374 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
7375 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
7376 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1, 1)));
7377 tree neg11 = fold_convert (type, negate_expr (arg11));
7378 tree arglist = tree_cons(NULL_TREE, arg10,
7379 build_tree_list (NULL_TREE, neg11));
7380 arg1 = build_function_call_expr (powfn, arglist);
7381 return fold (build2 (MULT_EXPR, type, arg0, arg1));
7385 if (flag_unsafe_math_optimizations)
7387 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
7388 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
7390 /* Optimize sin(x)/cos(x) as tan(x). */
7391 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_COS)
7392 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_COSF)
7393 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_COSL))
7394 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
7395 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
7397 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
7399 if (tanfn != NULL_TREE)
7400 return build_function_call_expr (tanfn,
7401 TREE_OPERAND (arg0, 1));
7404 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
7405 if (((fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_SIN)
7406 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_SINF)
7407 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_SINL))
7408 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
7409 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
7411 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
7413 if (tanfn != NULL_TREE)
7415 tree tmp = TREE_OPERAND (arg0, 1);
7416 tmp = build_function_call_expr (tanfn, tmp);
7417 return fold (build2 (RDIV_EXPR, type,
7418 build_real (type, dconst1), tmp));
7422 /* Optimize pow(x,c)/x as pow(x,c-1). */
7423 if (fcode0 == BUILT_IN_POW
7424 || fcode0 == BUILT_IN_POWF
7425 || fcode0 == BUILT_IN_POWL)
7427 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
7428 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0, 1)));
7429 if (TREE_CODE (arg01) == REAL_CST
7430 && ! TREE_CONSTANT_OVERFLOW (arg01)
7431 && operand_equal_p (arg1, arg00, 0))
7433 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7437 c = TREE_REAL_CST (arg01);
7438 real_arithmetic (&c, MINUS_EXPR, &c, &dconst1);
7439 arg = build_real (type, c);
7440 arglist = build_tree_list (NULL_TREE, arg);
7441 arglist = tree_cons (NULL_TREE, arg1, arglist);
7442 return build_function_call_expr (powfn, arglist);
7448 case TRUNC_DIV_EXPR:
7449 case ROUND_DIV_EXPR:
7450 case FLOOR_DIV_EXPR:
7452 case EXACT_DIV_EXPR:
7453 if (integer_onep (arg1))
7454 return non_lvalue (fold_convert (type, arg0));
7455 if (integer_zerop (arg1))
7458 if (!TYPE_UNSIGNED (type)
7459 && TREE_CODE (arg1) == INTEGER_CST
7460 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
7461 && TREE_INT_CST_HIGH (arg1) == -1)
7462 return fold_convert (type, negate_expr (arg0));
7464 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
7465 operation, EXACT_DIV_EXPR.
7467 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
7468 At one time others generated faster code, it's not clear if they do
7469 after the last round to changes to the DIV code in expmed.c. */
7470 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
7471 && multiple_of_p (type, arg0, arg1))
7472 return fold (build2 (EXACT_DIV_EXPR, type, arg0, arg1));
7474 if (TREE_CODE (arg1) == INTEGER_CST
7475 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
7477 return fold_convert (type, tem);
7482 case FLOOR_MOD_EXPR:
7483 case ROUND_MOD_EXPR:
7484 case TRUNC_MOD_EXPR:
7485 if (integer_onep (arg1))
7486 return omit_one_operand (type, integer_zero_node, arg0);
7487 if (integer_zerop (arg1))
7489 /* X % -1 is zero. */
7490 if (!TYPE_UNSIGNED (type)
7491 && TREE_CODE (arg1) == INTEGER_CST
7492 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
7493 && TREE_INT_CST_HIGH (arg1) == -1)
7494 return omit_one_operand (type, integer_zero_node, arg0);
7496 if (TREE_CODE (arg1) == INTEGER_CST
7497 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
7499 return fold_convert (type, tem);
7505 if (integer_all_onesp (arg0))
7506 return omit_one_operand (type, arg0, arg1);
7510 /* Optimize -1 >> x for arithmetic right shifts. */
7511 if (integer_all_onesp (arg0) && !TYPE_UNSIGNED (type))
7512 return omit_one_operand (type, arg0, arg1);
7513 /* ... fall through ... */
7517 if (integer_zerop (arg1))
7518 return non_lvalue (fold_convert (type, arg0));
7519 if (integer_zerop (arg0))
7520 return omit_one_operand (type, arg0, arg1);
7522 /* Since negative shift count is not well-defined,
7523 don't try to compute it in the compiler. */
7524 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
7526 /* Rewrite an LROTATE_EXPR by a constant into an
7527 RROTATE_EXPR by a new constant. */
7528 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
7530 tree tem = build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type)), 0);
7531 tem = fold_convert (TREE_TYPE (arg1), tem);
7532 tem = const_binop (MINUS_EXPR, tem, arg1, 0);
7533 return fold (build2 (RROTATE_EXPR, type, arg0, tem));
7536 /* If we have a rotate of a bit operation with the rotate count and
7537 the second operand of the bit operation both constant,
7538 permute the two operations. */
7539 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
7540 && (TREE_CODE (arg0) == BIT_AND_EXPR
7541 || TREE_CODE (arg0) == BIT_IOR_EXPR
7542 || TREE_CODE (arg0) == BIT_XOR_EXPR)
7543 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
7544 return fold (build2 (TREE_CODE (arg0), type,
7545 fold (build2 (code, type,
7546 TREE_OPERAND (arg0, 0), arg1)),
7547 fold (build2 (code, type,
7548 TREE_OPERAND (arg0, 1), arg1))));
7550 /* Two consecutive rotates adding up to the width of the mode can
7552 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
7553 && TREE_CODE (arg0) == RROTATE_EXPR
7554 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7555 && TREE_INT_CST_HIGH (arg1) == 0
7556 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
7557 && ((TREE_INT_CST_LOW (arg1)
7558 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
7559 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type))))
7560 return TREE_OPERAND (arg0, 0);
7565 if (operand_equal_p (arg0, arg1, 0))
7566 return omit_one_operand (type, arg0, arg1);
7567 if (INTEGRAL_TYPE_P (type)
7568 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
7569 return omit_one_operand (type, arg1, arg0);
7573 if (operand_equal_p (arg0, arg1, 0))
7574 return omit_one_operand (type, arg0, arg1);
7575 if (INTEGRAL_TYPE_P (type)
7576 && TYPE_MAX_VALUE (type)
7577 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
7578 return omit_one_operand (type, arg1, arg0);
7581 case TRUTH_NOT_EXPR:
7582 /* The argument to invert_truthvalue must have Boolean type. */
7583 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
7584 arg0 = fold_convert (boolean_type_node, arg0);
7586 /* Note that the operand of this must be an int
7587 and its values must be 0 or 1.
7588 ("true" is a fixed value perhaps depending on the language,
7589 but we don't handle values other than 1 correctly yet.) */
7590 tem = invert_truthvalue (arg0);
7591 /* Avoid infinite recursion. */
7592 if (TREE_CODE (tem) == TRUTH_NOT_EXPR)
7594 tem = fold_single_bit_test (code, arg0, arg1, type);
7599 return fold_convert (type, tem);
7601 case TRUTH_ANDIF_EXPR:
7602 /* Note that the operands of this must be ints
7603 and their values must be 0 or 1.
7604 ("true" is a fixed value perhaps depending on the language.) */
7605 /* If first arg is constant zero, return it. */
7606 if (integer_zerop (arg0))
7607 return fold_convert (type, arg0);
7608 case TRUTH_AND_EXPR:
7609 /* If either arg is constant true, drop it. */
7610 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
7611 return non_lvalue (fold_convert (type, arg1));
7612 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
7613 /* Preserve sequence points. */
7614 && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
7615 return non_lvalue (fold_convert (type, arg0));
7616 /* If second arg is constant zero, result is zero, but first arg
7617 must be evaluated. */
7618 if (integer_zerop (arg1))
7619 return omit_one_operand (type, arg1, arg0);
7620 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
7621 case will be handled here. */
7622 if (integer_zerop (arg0))
7623 return omit_one_operand (type, arg0, arg1);
7626 /* We only do these simplifications if we are optimizing. */
7630 /* Check for things like (A || B) && (A || C). We can convert this
7631 to A || (B && C). Note that either operator can be any of the four
7632 truth and/or operations and the transformation will still be
7633 valid. Also note that we only care about order for the
7634 ANDIF and ORIF operators. If B contains side effects, this
7635 might change the truth-value of A. */
7636 if (TREE_CODE (arg0) == TREE_CODE (arg1)
7637 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
7638 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
7639 || TREE_CODE (arg0) == TRUTH_AND_EXPR
7640 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
7641 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
7643 tree a00 = TREE_OPERAND (arg0, 0);
7644 tree a01 = TREE_OPERAND (arg0, 1);
7645 tree a10 = TREE_OPERAND (arg1, 0);
7646 tree a11 = TREE_OPERAND (arg1, 1);
7647 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
7648 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
7649 && (code == TRUTH_AND_EXPR
7650 || code == TRUTH_OR_EXPR));
7652 if (operand_equal_p (a00, a10, 0))
7653 return fold (build2 (TREE_CODE (arg0), type, a00,
7654 fold (build2 (code, type, a01, a11))));
7655 else if (commutative && operand_equal_p (a00, a11, 0))
7656 return fold (build2 (TREE_CODE (arg0), type, a00,
7657 fold (build2 (code, type, a01, a10))));
7658 else if (commutative && operand_equal_p (a01, a10, 0))
7659 return fold (build2 (TREE_CODE (arg0), type, a01,
7660 fold (build2 (code, type, a00, a11))));
7662 /* This case if tricky because we must either have commutative
7663 operators or else A10 must not have side-effects. */
7665 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
7666 && operand_equal_p (a01, a11, 0))
7667 return fold (build2 (TREE_CODE (arg0), type,
7668 fold (build2 (code, type, a00, a10)),
7672 /* See if we can build a range comparison. */
7673 if (0 != (tem = fold_range_test (t)))
7676 /* Check for the possibility of merging component references. If our
7677 lhs is another similar operation, try to merge its rhs with our
7678 rhs. Then try to merge our lhs and rhs. */
7679 if (TREE_CODE (arg0) == code
7680 && 0 != (tem = fold_truthop (code, type,
7681 TREE_OPERAND (arg0, 1), arg1)))
7682 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), tem));
7684 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
7689 case TRUTH_ORIF_EXPR:
7690 /* Note that the operands of this must be ints
7691 and their values must be 0 or true.
7692 ("true" is a fixed value perhaps depending on the language.) */
7693 /* If first arg is constant true, return it. */
7694 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
7695 return fold_convert (type, arg0);
7697 /* If either arg is constant zero, drop it. */
7698 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
7699 return non_lvalue (fold_convert (type, arg1));
7700 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
7701 /* Preserve sequence points. */
7702 && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
7703 return non_lvalue (fold_convert (type, arg0));
7704 /* If second arg is constant true, result is true, but we must
7705 evaluate first arg. */
7706 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
7707 return omit_one_operand (type, arg1, arg0);
7708 /* Likewise for first arg, but note this only occurs here for
7710 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
7711 return omit_one_operand (type, arg0, arg1);
7714 case TRUTH_XOR_EXPR:
7715 /* If either arg is constant zero, drop it. */
7716 if (integer_zerop (arg0))
7717 return non_lvalue (fold_convert (type, arg1));
7718 if (integer_zerop (arg1))
7719 return non_lvalue (fold_convert (type, arg0));
7720 /* If either arg is constant true, this is a logical inversion. */
7721 if (integer_onep (arg0))
7722 return non_lvalue (fold_convert (type, invert_truthvalue (arg1)));
7723 if (integer_onep (arg1))
7724 return non_lvalue (fold_convert (type, invert_truthvalue (arg0)));
7725 /* Identical arguments cancel to zero. */
7726 if (operand_equal_p (arg0, arg1, 0))
7727 return omit_one_operand (type, integer_zero_node, arg0);
7736 /* If one arg is a real or integer constant, put it last. */
7737 if (tree_swap_operands_p (arg0, arg1, true))
7738 return fold (build2 (swap_tree_comparison (code), type, arg1, arg0));
7740 /* If this is an equality comparison of the address of a non-weak
7741 object against zero, then we know the result. */
7742 if ((code == EQ_EXPR || code == NE_EXPR)
7743 && TREE_CODE (arg0) == ADDR_EXPR
7744 && DECL_P (TREE_OPERAND (arg0, 0))
7745 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
7746 && integer_zerop (arg1))
7747 return constant_boolean_node (code != EQ_EXPR, type);
7749 /* If this is an equality comparison of the address of two non-weak,
7750 unaliased symbols neither of which are extern (since we do not
7751 have access to attributes for externs), then we know the result. */
7752 if ((code == EQ_EXPR || code == NE_EXPR)
7753 && TREE_CODE (arg0) == ADDR_EXPR
7754 && DECL_P (TREE_OPERAND (arg0, 0))
7755 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
7756 && ! lookup_attribute ("alias",
7757 DECL_ATTRIBUTES (TREE_OPERAND (arg0, 0)))
7758 && ! DECL_EXTERNAL (TREE_OPERAND (arg0, 0))
7759 && TREE_CODE (arg1) == ADDR_EXPR
7760 && DECL_P (TREE_OPERAND (arg1, 0))
7761 && ! DECL_WEAK (TREE_OPERAND (arg1, 0))
7762 && ! lookup_attribute ("alias",
7763 DECL_ATTRIBUTES (TREE_OPERAND (arg1, 0)))
7764 && ! DECL_EXTERNAL (TREE_OPERAND (arg1, 0)))
7765 return constant_boolean_node (operand_equal_p (arg0, arg1, 0)
7766 ? code == EQ_EXPR : code != EQ_EXPR,
7769 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
7771 tree targ0 = strip_float_extensions (arg0);
7772 tree targ1 = strip_float_extensions (arg1);
7773 tree newtype = TREE_TYPE (targ0);
7775 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
7776 newtype = TREE_TYPE (targ1);
7778 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
7779 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
7780 return fold (build2 (code, type, fold_convert (newtype, targ0),
7781 fold_convert (newtype, targ1)));
7783 /* (-a) CMP (-b) -> b CMP a */
7784 if (TREE_CODE (arg0) == NEGATE_EXPR
7785 && TREE_CODE (arg1) == NEGATE_EXPR)
7786 return fold (build2 (code, type, TREE_OPERAND (arg1, 0),
7787 TREE_OPERAND (arg0, 0)));
7789 if (TREE_CODE (arg1) == REAL_CST)
7791 REAL_VALUE_TYPE cst;
7792 cst = TREE_REAL_CST (arg1);
7794 /* (-a) CMP CST -> a swap(CMP) (-CST) */
7795 if (TREE_CODE (arg0) == NEGATE_EXPR)
7797 fold (build2 (swap_tree_comparison (code), type,
7798 TREE_OPERAND (arg0, 0),
7799 build_real (TREE_TYPE (arg1),
7800 REAL_VALUE_NEGATE (cst))));
7802 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
7803 /* a CMP (-0) -> a CMP 0 */
7804 if (REAL_VALUE_MINUS_ZERO (cst))
7805 return fold (build2 (code, type, arg0,
7806 build_real (TREE_TYPE (arg1), dconst0)));
7808 /* x != NaN is always true, other ops are always false. */
7809 if (REAL_VALUE_ISNAN (cst)
7810 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))))
7812 tem = (code == NE_EXPR) ? integer_one_node : integer_zero_node;
7813 return omit_one_operand (type, tem, arg0);
7816 /* Fold comparisons against infinity. */
7817 if (REAL_VALUE_ISINF (cst))
7819 tem = fold_inf_compare (code, type, arg0, arg1);
7820 if (tem != NULL_TREE)
7825 /* If this is a comparison of a real constant with a PLUS_EXPR
7826 or a MINUS_EXPR of a real constant, we can convert it into a
7827 comparison with a revised real constant as long as no overflow
7828 occurs when unsafe_math_optimizations are enabled. */
7829 if (flag_unsafe_math_optimizations
7830 && TREE_CODE (arg1) == REAL_CST
7831 && (TREE_CODE (arg0) == PLUS_EXPR
7832 || TREE_CODE (arg0) == MINUS_EXPR)
7833 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
7834 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
7835 ? MINUS_EXPR : PLUS_EXPR,
7836 arg1, TREE_OPERAND (arg0, 1), 0))
7837 && ! TREE_CONSTANT_OVERFLOW (tem))
7838 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), tem));
7840 /* Likewise, we can simplify a comparison of a real constant with
7841 a MINUS_EXPR whose first operand is also a real constant, i.e.
7842 (c1 - x) < c2 becomes x > c1-c2. */
7843 if (flag_unsafe_math_optimizations
7844 && TREE_CODE (arg1) == REAL_CST
7845 && TREE_CODE (arg0) == MINUS_EXPR
7846 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST
7847 && 0 != (tem = const_binop (MINUS_EXPR, TREE_OPERAND (arg0, 0),
7849 && ! TREE_CONSTANT_OVERFLOW (tem))
7850 return fold (build2 (swap_tree_comparison (code), type,
7851 TREE_OPERAND (arg0, 1), tem));
7853 /* Fold comparisons against built-in math functions. */
7854 if (TREE_CODE (arg1) == REAL_CST
7855 && flag_unsafe_math_optimizations
7856 && ! flag_errno_math)
7858 enum built_in_function fcode = builtin_mathfn_code (arg0);
7860 if (fcode != END_BUILTINS)
7862 tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
7863 if (tem != NULL_TREE)
7869 /* Convert foo++ == CONST into ++foo == CONST + INCR. */
7870 if (TREE_CONSTANT (arg1)
7871 && (TREE_CODE (arg0) == POSTINCREMENT_EXPR
7872 || TREE_CODE (arg0) == POSTDECREMENT_EXPR)
7873 /* This optimization is invalid for ordered comparisons
7874 if CONST+INCR overflows or if foo+incr might overflow.
7875 This optimization is invalid for floating point due to rounding.
7876 For pointer types we assume overflow doesn't happen. */
7877 && (POINTER_TYPE_P (TREE_TYPE (arg0))
7878 || (INTEGRAL_TYPE_P (TREE_TYPE (arg0))
7879 && (code == EQ_EXPR || code == NE_EXPR))))
7881 tree varop, newconst;
7883 if (TREE_CODE (arg0) == POSTINCREMENT_EXPR)
7885 newconst = fold (build2 (PLUS_EXPR, TREE_TYPE (arg0),
7886 arg1, TREE_OPERAND (arg0, 1)));
7887 varop = build2 (PREINCREMENT_EXPR, TREE_TYPE (arg0),
7888 TREE_OPERAND (arg0, 0),
7889 TREE_OPERAND (arg0, 1));
7893 newconst = fold (build2 (MINUS_EXPR, TREE_TYPE (arg0),
7894 arg1, TREE_OPERAND (arg0, 1)));
7895 varop = build2 (PREDECREMENT_EXPR, TREE_TYPE (arg0),
7896 TREE_OPERAND (arg0, 0),
7897 TREE_OPERAND (arg0, 1));
7901 /* If VAROP is a reference to a bitfield, we must mask
7902 the constant by the width of the field. */
7903 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
7904 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (varop, 0), 1))
7905 && host_integerp (DECL_SIZE (TREE_OPERAND
7906 (TREE_OPERAND (varop, 0), 1)), 1))
7908 tree fielddecl = TREE_OPERAND (TREE_OPERAND (varop, 0), 1);
7909 HOST_WIDE_INT size = tree_low_cst (DECL_SIZE (fielddecl), 1);
7910 tree folded_compare, shift;
7912 /* First check whether the comparison would come out
7913 always the same. If we don't do that we would
7914 change the meaning with the masking. */
7915 folded_compare = fold (build2 (code, type,
7916 TREE_OPERAND (varop, 0), arg1));
7917 if (integer_zerop (folded_compare)
7918 || integer_onep (folded_compare))
7919 return omit_one_operand (type, folded_compare, varop);
7921 shift = build_int_2 (TYPE_PRECISION (TREE_TYPE (varop)) - size,
7923 shift = fold_convert (TREE_TYPE (varop), shift);
7924 newconst = fold (build2 (LSHIFT_EXPR, TREE_TYPE (varop),
7926 newconst = fold (build2 (RSHIFT_EXPR, TREE_TYPE (varop),
7930 return fold (build2 (code, type, varop, newconst));
7933 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
7934 This transformation affects the cases which are handled in later
7935 optimizations involving comparisons with non-negative constants. */
7936 if (TREE_CODE (arg1) == INTEGER_CST
7937 && TREE_CODE (arg0) != INTEGER_CST
7938 && tree_int_cst_sgn (arg1) > 0)
7943 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
7944 return fold (build2 (GT_EXPR, type, arg0, arg1));
7947 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
7948 return fold (build2 (LE_EXPR, type, arg0, arg1));
7955 /* Comparisons with the highest or lowest possible integer of
7956 the specified size will have known values.
7958 This is quite similar to fold_relational_hi_lo; however, my
7959 attempts to share the code have been nothing but trouble.
7960 I give up for now. */
7962 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1)));
7964 if (TREE_CODE (arg1) == INTEGER_CST
7965 && ! TREE_CONSTANT_OVERFLOW (arg1)
7966 && width <= HOST_BITS_PER_WIDE_INT
7967 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
7968 || POINTER_TYPE_P (TREE_TYPE (arg1))))
7970 unsigned HOST_WIDE_INT signed_max;
7971 unsigned HOST_WIDE_INT max, min;
7973 signed_max = ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1;
7975 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
7977 max = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
7983 min = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
7986 if (TREE_INT_CST_HIGH (arg1) == 0
7987 && TREE_INT_CST_LOW (arg1) == max)
7991 return omit_one_operand (type, integer_zero_node, arg0);
7994 return fold (build2 (EQ_EXPR, type, arg0, arg1));
7997 return omit_one_operand (type, integer_one_node, arg0);
8000 return fold (build2 (NE_EXPR, type, arg0, arg1));
8002 /* The GE_EXPR and LT_EXPR cases above are not normally
8003 reached because of previous transformations. */
8008 else if (TREE_INT_CST_HIGH (arg1) == 0
8009 && TREE_INT_CST_LOW (arg1) == max - 1)
8013 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
8014 return fold (build2 (EQ_EXPR, type, arg0, arg1));
8016 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
8017 return fold (build2 (NE_EXPR, type, arg0, arg1));
8021 else if (TREE_INT_CST_HIGH (arg1) == (min ? -1 : 0)
8022 && TREE_INT_CST_LOW (arg1) == min)
8026 return omit_one_operand (type, integer_zero_node, arg0);
8029 return fold (build2 (EQ_EXPR, type, arg0, arg1));
8032 return omit_one_operand (type, integer_one_node, arg0);
8035 return fold (build2 (NE_EXPR, type, arg0, arg1));
8040 else if (TREE_INT_CST_HIGH (arg1) == (min ? -1 : 0)
8041 && TREE_INT_CST_LOW (arg1) == min + 1)
8045 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
8046 return fold (build2 (NE_EXPR, type, arg0, arg1));
8048 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
8049 return fold (build2 (EQ_EXPR, type, arg0, arg1));
8054 else if (!in_gimple_form
8055 && TREE_INT_CST_HIGH (arg1) == 0
8056 && TREE_INT_CST_LOW (arg1) == signed_max
8057 && TYPE_UNSIGNED (TREE_TYPE (arg1))
8058 /* signed_type does not work on pointer types. */
8059 && INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
8061 /* The following case also applies to X < signed_max+1
8062 and X >= signed_max+1 because previous transformations. */
8063 if (code == LE_EXPR || code == GT_EXPR)
8066 st0 = lang_hooks.types.signed_type (TREE_TYPE (arg0));
8067 st1 = lang_hooks.types.signed_type (TREE_TYPE (arg1));
8069 (build2 (code == LE_EXPR ? GE_EXPR: LT_EXPR,
8070 type, fold_convert (st0, arg0),
8071 fold_convert (st1, integer_zero_node)));
8077 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
8078 a MINUS_EXPR of a constant, we can convert it into a comparison with
8079 a revised constant as long as no overflow occurs. */
8080 if ((code == EQ_EXPR || code == NE_EXPR)
8081 && TREE_CODE (arg1) == INTEGER_CST
8082 && (TREE_CODE (arg0) == PLUS_EXPR
8083 || TREE_CODE (arg0) == MINUS_EXPR)
8084 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8085 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
8086 ? MINUS_EXPR : PLUS_EXPR,
8087 arg1, TREE_OPERAND (arg0, 1), 0))
8088 && ! TREE_CONSTANT_OVERFLOW (tem))
8089 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), tem));
8091 /* Similarly for a NEGATE_EXPR. */
8092 else if ((code == EQ_EXPR || code == NE_EXPR)
8093 && TREE_CODE (arg0) == NEGATE_EXPR
8094 && TREE_CODE (arg1) == INTEGER_CST
8095 && 0 != (tem = negate_expr (arg1))
8096 && TREE_CODE (tem) == INTEGER_CST
8097 && ! TREE_CONSTANT_OVERFLOW (tem))
8098 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), tem));
8100 /* If we have X - Y == 0, we can convert that to X == Y and similarly
8101 for !=. Don't do this for ordered comparisons due to overflow. */
8102 else if ((code == NE_EXPR || code == EQ_EXPR)
8103 && integer_zerop (arg1) && TREE_CODE (arg0) == MINUS_EXPR)
8104 return fold (build2 (code, type,
8105 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1)));
8107 /* If we are widening one operand of an integer comparison,
8108 see if the other operand is similarly being widened. Perhaps we
8109 can do the comparison in the narrower type. */
8110 else if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
8111 && TREE_CODE (arg0) == NOP_EXPR
8112 && (tem = get_unwidened (arg0, NULL_TREE)) != arg0
8113 && (code == EQ_EXPR || code == NE_EXPR
8114 || TYPE_UNSIGNED (TREE_TYPE (arg0))
8115 == TYPE_UNSIGNED (TREE_TYPE (tem)))
8116 && (t1 = get_unwidened (arg1, TREE_TYPE (tem))) != 0
8117 && (TREE_TYPE (t1) == TREE_TYPE (tem)
8118 || (TREE_CODE (t1) == INTEGER_CST
8119 && int_fits_type_p (t1, TREE_TYPE (tem)))))
8120 return fold (build2 (code, type, tem,
8121 fold_convert (TREE_TYPE (tem), t1)));
8123 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
8124 constant, we can simplify it. */
8125 else if (TREE_CODE (arg1) == INTEGER_CST
8126 && (TREE_CODE (arg0) == MIN_EXPR
8127 || TREE_CODE (arg0) == MAX_EXPR)
8128 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8129 return optimize_minmax_comparison (t);
8131 /* If we are comparing an ABS_EXPR with a constant, we can
8132 convert all the cases into explicit comparisons, but they may
8133 well not be faster than doing the ABS and one comparison.
8134 But ABS (X) <= C is a range comparison, which becomes a subtraction
8135 and a comparison, and is probably faster. */
8136 else if (code == LE_EXPR && TREE_CODE (arg1) == INTEGER_CST
8137 && TREE_CODE (arg0) == ABS_EXPR
8138 && ! TREE_SIDE_EFFECTS (arg0)
8139 && (0 != (tem = negate_expr (arg1)))
8140 && TREE_CODE (tem) == INTEGER_CST
8141 && ! TREE_CONSTANT_OVERFLOW (tem))
8142 return fold (build2 (TRUTH_ANDIF_EXPR, type,
8143 build2 (GE_EXPR, type,
8144 TREE_OPERAND (arg0, 0), tem),
8145 build2 (LE_EXPR, type,
8146 TREE_OPERAND (arg0, 0), arg1)));
8148 /* If this is an EQ or NE comparison with zero and ARG0 is
8149 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
8150 two operations, but the latter can be done in one less insn
8151 on machines that have only two-operand insns or on which a
8152 constant cannot be the first operand. */
8153 if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR)
8154 && TREE_CODE (arg0) == BIT_AND_EXPR)
8156 tree arg00 = TREE_OPERAND (arg0, 0);
8157 tree arg01 = TREE_OPERAND (arg0, 1);
8158 if (TREE_CODE (arg00) == LSHIFT_EXPR
8159 && integer_onep (TREE_OPERAND (arg00, 0)))
8161 fold (build2 (code, type,
8162 build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
8163 build2 (RSHIFT_EXPR, TREE_TYPE (arg00),
8164 arg01, TREE_OPERAND (arg00, 1)),
8165 fold_convert (TREE_TYPE (arg0),
8168 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
8169 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
8171 fold (build2 (code, type,
8172 build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
8173 build2 (RSHIFT_EXPR, TREE_TYPE (arg01),
8174 arg00, TREE_OPERAND (arg01, 1)),
8175 fold_convert (TREE_TYPE (arg0),
8180 /* If this is an NE or EQ comparison of zero against the result of a
8181 signed MOD operation whose second operand is a power of 2, make
8182 the MOD operation unsigned since it is simpler and equivalent. */
8183 if ((code == NE_EXPR || code == EQ_EXPR)
8184 && integer_zerop (arg1)
8185 && !TYPE_UNSIGNED (TREE_TYPE (arg0))
8186 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
8187 || TREE_CODE (arg0) == CEIL_MOD_EXPR
8188 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
8189 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
8190 && integer_pow2p (TREE_OPERAND (arg0, 1)))
8192 tree newtype = lang_hooks.types.unsigned_type (TREE_TYPE (arg0));
8193 tree newmod = build2 (TREE_CODE (arg0), newtype,
8194 fold_convert (newtype,
8195 TREE_OPERAND (arg0, 0)),
8196 fold_convert (newtype,
8197 TREE_OPERAND (arg0, 1)));
8199 return build2 (code, type, newmod, fold_convert (newtype, arg1));
8202 /* If this is an NE comparison of zero with an AND of one, remove the
8203 comparison since the AND will give the correct value. */
8204 if (code == NE_EXPR && integer_zerop (arg1)
8205 && TREE_CODE (arg0) == BIT_AND_EXPR
8206 && integer_onep (TREE_OPERAND (arg0, 1)))
8207 return fold_convert (type, arg0);
8209 /* If we have (A & C) == C where C is a power of 2, convert this into
8210 (A & C) != 0. Similarly for NE_EXPR. */
8211 if ((code == EQ_EXPR || code == NE_EXPR)
8212 && TREE_CODE (arg0) == BIT_AND_EXPR
8213 && integer_pow2p (TREE_OPERAND (arg0, 1))
8214 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
8215 return fold (build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
8216 arg0, integer_zero_node));
8218 /* If we have (A & C) != 0 or (A & C) == 0 and C is a power of
8219 2, then fold the expression into shifts and logical operations. */
8220 tem = fold_single_bit_test (code, arg0, arg1, type);
8224 /* If we have (A & C) == D where D & ~C != 0, convert this into 0.
8225 Similarly for NE_EXPR. */
8226 if ((code == EQ_EXPR || code == NE_EXPR)
8227 && TREE_CODE (arg0) == BIT_AND_EXPR
8228 && TREE_CODE (arg1) == INTEGER_CST
8229 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8232 = fold (build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
8233 arg1, build1 (BIT_NOT_EXPR,
8234 TREE_TYPE (TREE_OPERAND (arg0, 1)),
8235 TREE_OPERAND (arg0, 1))));
8236 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
8237 if (integer_nonzerop (dandnotc))
8238 return omit_one_operand (type, rslt, arg0);
8241 /* If we have (A | C) == D where C & ~D != 0, convert this into 0.
8242 Similarly for NE_EXPR. */
8243 if ((code == EQ_EXPR || code == NE_EXPR)
8244 && TREE_CODE (arg0) == BIT_IOR_EXPR
8245 && TREE_CODE (arg1) == INTEGER_CST
8246 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8249 = fold (build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
8250 TREE_OPERAND (arg0, 1),
8251 build1 (BIT_NOT_EXPR, TREE_TYPE (arg1), arg1)));
8252 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
8253 if (integer_nonzerop (candnotd))
8254 return omit_one_operand (type, rslt, arg0);
8257 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
8258 and similarly for >= into !=. */
8259 if ((code == LT_EXPR || code == GE_EXPR)
8260 && TYPE_UNSIGNED (TREE_TYPE (arg0))
8261 && TREE_CODE (arg1) == LSHIFT_EXPR
8262 && integer_onep (TREE_OPERAND (arg1, 0)))
8263 return build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
8264 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
8265 TREE_OPERAND (arg1, 1)),
8266 fold_convert (TREE_TYPE (arg0), integer_zero_node));
8268 else if ((code == LT_EXPR || code == GE_EXPR)
8269 && TYPE_UNSIGNED (TREE_TYPE (arg0))
8270 && (TREE_CODE (arg1) == NOP_EXPR
8271 || TREE_CODE (arg1) == CONVERT_EXPR)
8272 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
8273 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
8275 build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
8276 fold_convert (TREE_TYPE (arg0),
8277 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
8278 TREE_OPERAND (TREE_OPERAND (arg1, 0),
8280 fold_convert (TREE_TYPE (arg0), integer_zero_node));
8282 /* Simplify comparison of something with itself. (For IEEE
8283 floating-point, we can only do some of these simplifications.) */
8284 if (operand_equal_p (arg0, arg1, 0))
8289 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
8290 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8291 return constant_boolean_node (1, type);
8296 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
8297 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8298 return constant_boolean_node (1, type);
8299 return fold (build2 (EQ_EXPR, type, arg0, arg1));
8302 /* For NE, we can only do this simplification if integer
8303 or we don't honor IEEE floating point NaNs. */
8304 if (FLOAT_TYPE_P (TREE_TYPE (arg0))
8305 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8307 /* ... fall through ... */
8310 return constant_boolean_node (0, type);
8316 /* If we are comparing an expression that just has comparisons
8317 of two integer values, arithmetic expressions of those comparisons,
8318 and constants, we can simplify it. There are only three cases
8319 to check: the two values can either be equal, the first can be
8320 greater, or the second can be greater. Fold the expression for
8321 those three values. Since each value must be 0 or 1, we have
8322 eight possibilities, each of which corresponds to the constant 0
8323 or 1 or one of the six possible comparisons.
8325 This handles common cases like (a > b) == 0 but also handles
8326 expressions like ((x > y) - (y > x)) > 0, which supposedly
8327 occur in macroized code. */
8329 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
8331 tree cval1 = 0, cval2 = 0;
8334 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
8335 /* Don't handle degenerate cases here; they should already
8336 have been handled anyway. */
8337 && cval1 != 0 && cval2 != 0
8338 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
8339 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
8340 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
8341 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
8342 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
8343 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
8344 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
8346 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
8347 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
8349 /* We can't just pass T to eval_subst in case cval1 or cval2
8350 was the same as ARG1. */
8353 = fold (build2 (code, type,
8354 eval_subst (arg0, cval1, maxval,
8358 = fold (build2 (code, type,
8359 eval_subst (arg0, cval1, maxval,
8363 = fold (build2 (code, type,
8364 eval_subst (arg0, cval1, minval,
8368 /* All three of these results should be 0 or 1. Confirm they
8369 are. Then use those values to select the proper code
8372 if ((integer_zerop (high_result)
8373 || integer_onep (high_result))
8374 && (integer_zerop (equal_result)
8375 || integer_onep (equal_result))
8376 && (integer_zerop (low_result)
8377 || integer_onep (low_result)))
8379 /* Make a 3-bit mask with the high-order bit being the
8380 value for `>', the next for '=', and the low for '<'. */
8381 switch ((integer_onep (high_result) * 4)
8382 + (integer_onep (equal_result) * 2)
8383 + integer_onep (low_result))
8387 return omit_one_operand (type, integer_zero_node, arg0);
8408 return omit_one_operand (type, integer_one_node, arg0);
8411 tem = build2 (code, type, cval1, cval2);
8413 return save_expr (tem);
8420 /* If this is a comparison of a field, we may be able to simplify it. */
8421 if (((TREE_CODE (arg0) == COMPONENT_REF
8422 && lang_hooks.can_use_bit_fields_p ())
8423 || TREE_CODE (arg0) == BIT_FIELD_REF)
8424 && (code == EQ_EXPR || code == NE_EXPR)
8425 /* Handle the constant case even without -O
8426 to make sure the warnings are given. */
8427 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
8429 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
8434 /* If this is a comparison of complex values and either or both sides
8435 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
8436 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
8437 This may prevent needless evaluations. */
8438 if ((code == EQ_EXPR || code == NE_EXPR)
8439 && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
8440 && (TREE_CODE (arg0) == COMPLEX_EXPR
8441 || TREE_CODE (arg1) == COMPLEX_EXPR
8442 || TREE_CODE (arg0) == COMPLEX_CST
8443 || TREE_CODE (arg1) == COMPLEX_CST))
8445 tree subtype = TREE_TYPE (TREE_TYPE (arg0));
8446 tree real0, imag0, real1, imag1;
8448 arg0 = save_expr (arg0);
8449 arg1 = save_expr (arg1);
8450 real0 = fold (build1 (REALPART_EXPR, subtype, arg0));
8451 imag0 = fold (build1 (IMAGPART_EXPR, subtype, arg0));
8452 real1 = fold (build1 (REALPART_EXPR, subtype, arg1));
8453 imag1 = fold (build1 (IMAGPART_EXPR, subtype, arg1));
8455 return fold (build2 ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR
8458 fold (build2 (code, type, real0, real1)),
8459 fold (build2 (code, type, imag0, imag1))));
8462 /* Optimize comparisons of strlen vs zero to a compare of the
8463 first character of the string vs zero. To wit,
8464 strlen(ptr) == 0 => *ptr == 0
8465 strlen(ptr) != 0 => *ptr != 0
8466 Other cases should reduce to one of these two (or a constant)
8467 due to the return value of strlen being unsigned. */
8468 if ((code == EQ_EXPR || code == NE_EXPR)
8469 && integer_zerop (arg1)
8470 && TREE_CODE (arg0) == CALL_EXPR)
8472 tree fndecl = get_callee_fndecl (arg0);
8476 && DECL_BUILT_IN (fndecl)
8477 && DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_MD
8478 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
8479 && (arglist = TREE_OPERAND (arg0, 1))
8480 && TREE_CODE (TREE_TYPE (TREE_VALUE (arglist))) == POINTER_TYPE
8481 && ! TREE_CHAIN (arglist))
8482 return fold (build2 (code, type,
8483 build1 (INDIRECT_REF, char_type_node,
8484 TREE_VALUE(arglist)),
8485 integer_zero_node));
8488 /* We can fold X/C1 op C2 where C1 and C2 are integer constants
8489 into a single range test. */
8490 if (TREE_CODE (arg0) == TRUNC_DIV_EXPR
8491 && TREE_CODE (arg1) == INTEGER_CST
8492 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8493 && !integer_zerop (TREE_OPERAND (arg0, 1))
8494 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
8495 && !TREE_OVERFLOW (arg1))
8497 t1 = fold_div_compare (code, type, arg0, arg1);
8498 if (t1 != NULL_TREE)
8502 /* Both ARG0 and ARG1 are known to be constants at this point. */
8503 t1 = fold_relational_const (code, type, arg0, arg1);
8504 return (t1 == NULL_TREE ? t : t1);
8506 case UNORDERED_EXPR:
8514 if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
8516 t1 = fold_relational_const (code, type, arg0, arg1);
8517 if (t1 != NULL_TREE)
8521 /* If the first operand is NaN, the result is constant. */
8522 if (TREE_CODE (arg0) == REAL_CST
8523 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
8524 && (code != LTGT_EXPR || ! flag_trapping_math))
8526 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
8529 return omit_one_operand (type, t1, arg1);
8532 /* If the second operand is NaN, the result is constant. */
8533 if (TREE_CODE (arg1) == REAL_CST
8534 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg1))
8535 && (code != LTGT_EXPR || ! flag_trapping_math))
8537 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
8540 return omit_one_operand (type, t1, arg0);
8543 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
8545 tree targ0 = strip_float_extensions (arg0);
8546 tree targ1 = strip_float_extensions (arg1);
8547 tree newtype = TREE_TYPE (targ0);
8549 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
8550 newtype = TREE_TYPE (targ1);
8552 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
8553 return fold (build2 (code, type, fold_convert (newtype, targ0),
8554 fold_convert (newtype, targ1)));
8560 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
8561 so all simple results must be passed through pedantic_non_lvalue. */
8562 if (TREE_CODE (arg0) == INTEGER_CST)
8564 tem = TREE_OPERAND (t, (integer_zerop (arg0) ? 2 : 1));
8565 /* Only optimize constant conditions when the selected branch
8566 has the same type as the COND_EXPR. This avoids optimizing
8567 away "c ? x : throw", where the throw has a void type. */
8568 if (! VOID_TYPE_P (TREE_TYPE (tem))
8569 || VOID_TYPE_P (type))
8570 return pedantic_non_lvalue (tem);
8573 if (operand_equal_p (arg1, TREE_OPERAND (t, 2), 0))
8574 return pedantic_omit_one_operand (type, arg1, arg0);
8576 /* If we have A op B ? A : C, we may be able to convert this to a
8577 simpler expression, depending on the operation and the values
8578 of B and C. Signed zeros prevent all of these transformations,
8579 for reasons given above each one.
8581 Also try swapping the arguments and inverting the conditional. */
8582 if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
8583 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
8584 arg1, TREE_OPERAND (arg0, 1))
8585 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
8587 tem = fold_cond_expr_with_comparison (type, arg0,
8588 TREE_OPERAND (t, 2));
8593 if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
8594 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
8595 TREE_OPERAND (t, 2),
8596 TREE_OPERAND (arg0, 1))
8597 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (TREE_OPERAND (t, 2)))))
8599 tem = invert_truthvalue (arg0);
8600 if (TREE_CODE_CLASS (TREE_CODE (tem)) == '<')
8602 tem = fold_cond_expr_with_comparison (type, tem, arg1);
8608 /* If the second operand is simpler than the third, swap them
8609 since that produces better jump optimization results. */
8610 if (tree_swap_operands_p (TREE_OPERAND (t, 1),
8611 TREE_OPERAND (t, 2), false))
8613 /* See if this can be inverted. If it can't, possibly because
8614 it was a floating-point inequality comparison, don't do
8616 tem = invert_truthvalue (arg0);
8618 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
8619 return fold (build3 (code, type, tem,
8620 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1)));
8623 /* Convert A ? 1 : 0 to simply A. */
8624 if (integer_onep (TREE_OPERAND (t, 1))
8625 && integer_zerop (TREE_OPERAND (t, 2))
8626 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
8627 call to fold will try to move the conversion inside
8628 a COND, which will recurse. In that case, the COND_EXPR
8629 is probably the best choice, so leave it alone. */
8630 && type == TREE_TYPE (arg0))
8631 return pedantic_non_lvalue (arg0);
8633 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
8634 over COND_EXPR in cases such as floating point comparisons. */
8635 if (integer_zerop (TREE_OPERAND (t, 1))
8636 && integer_onep (TREE_OPERAND (t, 2))
8637 && truth_value_p (TREE_CODE (arg0)))
8638 return pedantic_non_lvalue (fold_convert (type,
8639 invert_truthvalue (arg0)));
8641 /* A < 0 ? <sign bit of A> : 0 is simply (A & <sign bit of A>). */
8642 if (TREE_CODE (arg0) == LT_EXPR
8643 && integer_zerop (TREE_OPERAND (arg0, 1))
8644 && integer_zerop (TREE_OPERAND (t, 2))
8645 && (tem = sign_bit_p (TREE_OPERAND (arg0, 0), arg1)))
8646 return fold_convert (type, fold (build2 (BIT_AND_EXPR,
8647 TREE_TYPE (tem), tem, arg1)));
8649 /* (A >> N) & 1 ? (1 << N) : 0 is simply A & (1 << N). A & 1 was
8650 already handled above. */
8651 if (TREE_CODE (arg0) == BIT_AND_EXPR
8652 && integer_onep (TREE_OPERAND (arg0, 1))
8653 && integer_zerop (TREE_OPERAND (t, 2))
8654 && integer_pow2p (arg1))
8656 tree tem = TREE_OPERAND (arg0, 0);
8658 if (TREE_CODE (tem) == RSHIFT_EXPR
8659 && (unsigned HOST_WIDE_INT) tree_log2 (arg1) ==
8660 TREE_INT_CST_LOW (TREE_OPERAND (tem, 1)))
8661 return fold (build2 (BIT_AND_EXPR, type,
8662 TREE_OPERAND (tem, 0), arg1));
8665 /* A & N ? N : 0 is simply A & N if N is a power of two. This
8666 is probably obsolete because the first operand should be a
8667 truth value (that's why we have the two cases above), but let's
8668 leave it in until we can confirm this for all front-ends. */
8669 if (integer_zerop (TREE_OPERAND (t, 2))
8670 && TREE_CODE (arg0) == NE_EXPR
8671 && integer_zerop (TREE_OPERAND (arg0, 1))
8672 && integer_pow2p (arg1)
8673 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
8674 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
8675 arg1, OEP_ONLY_CONST))
8676 return pedantic_non_lvalue (fold_convert (type,
8677 TREE_OPERAND (arg0, 0)));
8679 /* Convert A ? B : 0 into A && B if A and B are truth values. */
8680 if (integer_zerop (TREE_OPERAND (t, 2))
8681 && truth_value_p (TREE_CODE (arg0))
8682 && truth_value_p (TREE_CODE (arg1)))
8683 return fold (build2 (TRUTH_ANDIF_EXPR, type, arg0, arg1));
8685 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
8686 if (integer_onep (TREE_OPERAND (t, 2))
8687 && truth_value_p (TREE_CODE (arg0))
8688 && truth_value_p (TREE_CODE (arg1)))
8690 /* Only perform transformation if ARG0 is easily inverted. */
8691 tem = invert_truthvalue (arg0);
8692 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
8693 return fold (build2 (TRUTH_ORIF_EXPR, type, tem, arg1));
8696 /* Convert A ? 0 : B into !A && B if A and B are truth values. */
8697 if (integer_zerop (arg1)
8698 && truth_value_p (TREE_CODE (arg0))
8699 && truth_value_p (TREE_CODE (TREE_OPERAND (t, 2))))
8701 /* Only perform transformation if ARG0 is easily inverted. */
8702 tem = invert_truthvalue (arg0);
8703 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
8704 return fold (build2 (TRUTH_ANDIF_EXPR, type, tem,
8705 TREE_OPERAND (t, 2)));
8708 /* Convert A ? 1 : B into A || B if A and B are truth values. */
8709 if (integer_onep (arg1)
8710 && truth_value_p (TREE_CODE (arg0))
8711 && truth_value_p (TREE_CODE (TREE_OPERAND (t, 2))))
8712 return fold (build2 (TRUTH_ORIF_EXPR, type, arg0,
8713 TREE_OPERAND (t, 2)));
8718 /* When pedantic, a compound expression can be neither an lvalue
8719 nor an integer constant expression. */
8720 if (TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
8722 /* Don't let (0, 0) be null pointer constant. */
8723 tem = integer_zerop (arg1) ? build1 (NOP_EXPR, type, arg1)
8724 : fold_convert (type, arg1);
8725 return pedantic_non_lvalue (tem);
8729 return build_complex (type, arg0, arg1);
8733 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8735 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
8736 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
8737 TREE_OPERAND (arg0, 1));
8738 else if (TREE_CODE (arg0) == COMPLEX_CST)
8739 return TREE_REALPART (arg0);
8740 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8741 return fold (build2 (TREE_CODE (arg0), type,
8742 fold (build1 (REALPART_EXPR, type,
8743 TREE_OPERAND (arg0, 0))),
8744 fold (build1 (REALPART_EXPR, type,
8745 TREE_OPERAND (arg0, 1)))));
8749 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8750 return fold_convert (type, integer_zero_node);
8751 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
8752 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
8753 TREE_OPERAND (arg0, 0));
8754 else if (TREE_CODE (arg0) == COMPLEX_CST)
8755 return TREE_IMAGPART (arg0);
8756 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8757 return fold (build2 (TREE_CODE (arg0), type,
8758 fold (build1 (IMAGPART_EXPR, type,
8759 TREE_OPERAND (arg0, 0))),
8760 fold (build1 (IMAGPART_EXPR, type,
8761 TREE_OPERAND (arg0, 1)))));
8764 /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
8766 case CLEANUP_POINT_EXPR:
8767 if (! has_cleanups (arg0))
8768 return TREE_OPERAND (t, 0);
8771 enum tree_code code0 = TREE_CODE (arg0);
8772 int kind0 = TREE_CODE_CLASS (code0);
8773 tree arg00 = TREE_OPERAND (arg0, 0);
8776 if (kind0 == '1' || code0 == TRUTH_NOT_EXPR)
8777 return fold (build1 (code0, type,
8778 fold (build1 (CLEANUP_POINT_EXPR,
8779 TREE_TYPE (arg00), arg00))));
8781 if (kind0 == '<' || kind0 == '2'
8782 || code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR
8783 || code0 == TRUTH_AND_EXPR || code0 == TRUTH_OR_EXPR
8784 || code0 == TRUTH_XOR_EXPR)
8786 arg01 = TREE_OPERAND (arg0, 1);
8788 if (TREE_CONSTANT (arg00)
8789 || ((code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR)
8790 && ! has_cleanups (arg00)))
8791 return fold (build2 (code0, type, arg00,
8792 fold (build1 (CLEANUP_POINT_EXPR,
8793 TREE_TYPE (arg01), arg01))));
8795 if (TREE_CONSTANT (arg01))
8796 return fold (build2 (code0, type,
8797 fold (build1 (CLEANUP_POINT_EXPR,
8798 TREE_TYPE (arg00), arg00)),
8806 /* Check for a built-in function. */
8807 if (TREE_CODE (TREE_OPERAND (t, 0)) == ADDR_EXPR
8808 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0))
8810 && DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (t, 0), 0)))
8812 tree tmp = fold_builtin (t);
8820 } /* switch (code) */
8823 #ifdef ENABLE_FOLD_CHECKING
8826 static void fold_checksum_tree (tree, struct md5_ctx *, htab_t);
8827 static void fold_check_failed (tree, tree);
8828 void print_fold_checksum (tree);
8830 /* When --enable-checking=fold, compute a digest of expr before
8831 and after actual fold call to see if fold did not accidentally
8832 change original expr. */
8839 unsigned char checksum_before[16], checksum_after[16];
8842 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
8843 md5_init_ctx (&ctx);
8844 fold_checksum_tree (expr, &ctx, ht);
8845 md5_finish_ctx (&ctx, checksum_before);
8848 ret = fold_1 (expr);
8850 md5_init_ctx (&ctx);
8851 fold_checksum_tree (expr, &ctx, ht);
8852 md5_finish_ctx (&ctx, checksum_after);
8855 if (memcmp (checksum_before, checksum_after, 16))
8856 fold_check_failed (expr, ret);
8862 print_fold_checksum (tree expr)
8865 unsigned char checksum[16], cnt;
8868 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
8869 md5_init_ctx (&ctx);
8870 fold_checksum_tree (expr, &ctx, ht);
8871 md5_finish_ctx (&ctx, checksum);
8873 for (cnt = 0; cnt < 16; ++cnt)
8874 fprintf (stderr, "%02x", checksum[cnt]);
8875 putc ('\n', stderr);
8879 fold_check_failed (tree expr ATTRIBUTE_UNUSED, tree ret ATTRIBUTE_UNUSED)
8881 internal_error ("fold check: original tree changed by fold");
8885 fold_checksum_tree (tree expr, struct md5_ctx *ctx, htab_t ht)
8888 enum tree_code code;
8889 char buf[sizeof (struct tree_decl)];
8892 if (sizeof (struct tree_exp) + 5 * sizeof (tree)
8893 > sizeof (struct tree_decl)
8894 || sizeof (struct tree_type) > sizeof (struct tree_decl))
8898 slot = htab_find_slot (ht, expr, INSERT);
8902 code = TREE_CODE (expr);
8903 if (code == SAVE_EXPR && SAVE_EXPR_NOPLACEHOLDER (expr))
8905 /* Allow SAVE_EXPR_NOPLACEHOLDER flag to be modified. */
8906 memcpy (buf, expr, tree_size (expr));
8908 SAVE_EXPR_NOPLACEHOLDER (expr) = 0;
8910 else if (TREE_CODE_CLASS (code) == 'd' && DECL_ASSEMBLER_NAME_SET_P (expr))
8912 /* Allow DECL_ASSEMBLER_NAME to be modified. */
8913 memcpy (buf, expr, tree_size (expr));
8915 SET_DECL_ASSEMBLER_NAME (expr, NULL);
8917 else if (TREE_CODE_CLASS (code) == 't'
8918 && (TYPE_POINTER_TO (expr) || TYPE_REFERENCE_TO (expr)))
8920 /* Allow TYPE_POINTER_TO and TYPE_REFERENCE_TO to be modified. */
8921 memcpy (buf, expr, tree_size (expr));
8923 TYPE_POINTER_TO (expr) = NULL;
8924 TYPE_REFERENCE_TO (expr) = NULL;
8926 md5_process_bytes (expr, tree_size (expr), ctx);
8927 fold_checksum_tree (TREE_TYPE (expr), ctx, ht);
8928 if (TREE_CODE_CLASS (code) != 't' && TREE_CODE_CLASS (code) != 'd')
8929 fold_checksum_tree (TREE_CHAIN (expr), ctx, ht);
8930 len = TREE_CODE_LENGTH (code);
8931 switch (TREE_CODE_CLASS (code))
8937 md5_process_bytes (TREE_STRING_POINTER (expr),
8938 TREE_STRING_LENGTH (expr), ctx);
8941 fold_checksum_tree (TREE_REALPART (expr), ctx, ht);
8942 fold_checksum_tree (TREE_IMAGPART (expr), ctx, ht);
8945 fold_checksum_tree (TREE_VECTOR_CST_ELTS (expr), ctx, ht);
8955 fold_checksum_tree (TREE_PURPOSE (expr), ctx, ht);
8956 fold_checksum_tree (TREE_VALUE (expr), ctx, ht);
8959 for (i = 0; i < TREE_VEC_LENGTH (expr); ++i)
8960 fold_checksum_tree (TREE_VEC_ELT (expr, i), ctx, ht);
8969 case SAVE_EXPR: len = 2; break;
8970 case GOTO_SUBROUTINE_EXPR: len = 0; break;
8971 case RTL_EXPR: len = 0; break;
8972 case WITH_CLEANUP_EXPR: len = 2; break;
8981 for (i = 0; i < len; ++i)
8982 fold_checksum_tree (TREE_OPERAND (expr, i), ctx, ht);
8985 fold_checksum_tree (DECL_SIZE (expr), ctx, ht);
8986 fold_checksum_tree (DECL_SIZE_UNIT (expr), ctx, ht);
8987 fold_checksum_tree (DECL_NAME (expr), ctx, ht);
8988 fold_checksum_tree (DECL_CONTEXT (expr), ctx, ht);
8989 fold_checksum_tree (DECL_ARGUMENTS (expr), ctx, ht);
8990 fold_checksum_tree (DECL_RESULT_FLD (expr), ctx, ht);
8991 fold_checksum_tree (DECL_INITIAL (expr), ctx, ht);
8992 fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr), ctx, ht);
8993 fold_checksum_tree (DECL_SECTION_NAME (expr), ctx, ht);
8994 fold_checksum_tree (DECL_ATTRIBUTES (expr), ctx, ht);
8995 fold_checksum_tree (DECL_VINDEX (expr), ctx, ht);
8998 if (TREE_CODE (expr) == ENUMERAL_TYPE)
8999 fold_checksum_tree (TYPE_VALUES (expr), ctx, ht);
9000 fold_checksum_tree (TYPE_SIZE (expr), ctx, ht);
9001 fold_checksum_tree (TYPE_SIZE_UNIT (expr), ctx, ht);
9002 fold_checksum_tree (TYPE_ATTRIBUTES (expr), ctx, ht);
9003 fold_checksum_tree (TYPE_NAME (expr), ctx, ht);
9004 if (INTEGRAL_TYPE_P (expr)
9005 || SCALAR_FLOAT_TYPE_P (expr))
9007 fold_checksum_tree (TYPE_MIN_VALUE (expr), ctx, ht);
9008 fold_checksum_tree (TYPE_MAX_VALUE (expr), ctx, ht);
9010 fold_checksum_tree (TYPE_MAIN_VARIANT (expr), ctx, ht);
9011 fold_checksum_tree (TYPE_BINFO (expr), ctx, ht);
9012 fold_checksum_tree (TYPE_CONTEXT (expr), ctx, ht);
9021 /* Perform constant folding and related simplification of initializer
9022 expression EXPR. This behaves identically to "fold" but ignores
9023 potential run-time traps and exceptions that fold must preserve. */
9026 fold_initializer (tree expr)
9028 int saved_signaling_nans = flag_signaling_nans;
9029 int saved_trapping_math = flag_trapping_math;
9030 int saved_trapv = flag_trapv;
9033 flag_signaling_nans = 0;
9034 flag_trapping_math = 0;
9037 result = fold (expr);
9039 flag_signaling_nans = saved_signaling_nans;
9040 flag_trapping_math = saved_trapping_math;
9041 flag_trapv = saved_trapv;
9046 /* Determine if first argument is a multiple of second argument. Return 0 if
9047 it is not, or we cannot easily determined it to be.
9049 An example of the sort of thing we care about (at this point; this routine
9050 could surely be made more general, and expanded to do what the *_DIV_EXPR's
9051 fold cases do now) is discovering that
9053 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
9059 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
9061 This code also handles discovering that
9063 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
9065 is a multiple of 8 so we don't have to worry about dealing with a
9068 Note that we *look* inside a SAVE_EXPR only to determine how it was
9069 calculated; it is not safe for fold to do much of anything else with the
9070 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
9071 at run time. For example, the latter example above *cannot* be implemented
9072 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
9073 evaluation time of the original SAVE_EXPR is not necessarily the same at
9074 the time the new expression is evaluated. The only optimization of this
9075 sort that would be valid is changing
9077 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
9081 SAVE_EXPR (I) * SAVE_EXPR (J)
9083 (where the same SAVE_EXPR (J) is used in the original and the
9084 transformed version). */
9087 multiple_of_p (tree type, tree top, tree bottom)
9089 if (operand_equal_p (top, bottom, 0))
9092 if (TREE_CODE (type) != INTEGER_TYPE)
9095 switch (TREE_CODE (top))
9098 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
9099 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
9103 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
9104 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
9107 if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
9111 op1 = TREE_OPERAND (top, 1);
9112 /* const_binop may not detect overflow correctly,
9113 so check for it explicitly here. */
9114 if (TYPE_PRECISION (TREE_TYPE (size_one_node))
9115 > TREE_INT_CST_LOW (op1)
9116 && TREE_INT_CST_HIGH (op1) == 0
9117 && 0 != (t1 = fold_convert (type,
9118 const_binop (LSHIFT_EXPR,
9121 && ! TREE_OVERFLOW (t1))
9122 return multiple_of_p (type, t1, bottom);
9127 /* Can't handle conversions from non-integral or wider integral type. */
9128 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
9129 || (TYPE_PRECISION (type)
9130 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
9133 /* .. fall through ... */
9136 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
9139 if (TREE_CODE (bottom) != INTEGER_CST
9140 || (TYPE_UNSIGNED (type)
9141 && (tree_int_cst_sgn (top) < 0
9142 || tree_int_cst_sgn (bottom) < 0)))
9144 return integer_zerop (const_binop (TRUNC_MOD_EXPR,
9152 /* Return true if `t' is known to be non-negative. */
9155 tree_expr_nonnegative_p (tree t)
9157 switch (TREE_CODE (t))
9163 return tree_int_cst_sgn (t) >= 0;
9166 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
9169 if (FLOAT_TYPE_P (TREE_TYPE (t)))
9170 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9171 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9173 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
9174 both unsigned and at least 2 bits shorter than the result. */
9175 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
9176 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
9177 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
9179 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
9180 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
9181 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
9182 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
9184 unsigned int prec = MAX (TYPE_PRECISION (inner1),
9185 TYPE_PRECISION (inner2)) + 1;
9186 return prec < TYPE_PRECISION (TREE_TYPE (t));
9192 if (FLOAT_TYPE_P (TREE_TYPE (t)))
9194 /* x * x for floating point x is always non-negative. */
9195 if (operand_equal_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1), 0))
9197 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9198 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9201 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
9202 both unsigned and their total bits is shorter than the result. */
9203 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
9204 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
9205 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
9207 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
9208 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
9209 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
9210 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
9211 return TYPE_PRECISION (inner1) + TYPE_PRECISION (inner2)
9212 < TYPE_PRECISION (TREE_TYPE (t));
9216 case TRUNC_DIV_EXPR:
9218 case FLOOR_DIV_EXPR:
9219 case ROUND_DIV_EXPR:
9220 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9221 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9223 case TRUNC_MOD_EXPR:
9225 case FLOOR_MOD_EXPR:
9226 case ROUND_MOD_EXPR:
9227 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9230 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9231 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9234 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
9235 || tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9238 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9239 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9243 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
9244 tree outer_type = TREE_TYPE (t);
9246 if (TREE_CODE (outer_type) == REAL_TYPE)
9248 if (TREE_CODE (inner_type) == REAL_TYPE)
9249 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9250 if (TREE_CODE (inner_type) == INTEGER_TYPE)
9252 if (TYPE_UNSIGNED (inner_type))
9254 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9257 else if (TREE_CODE (outer_type) == INTEGER_TYPE)
9259 if (TREE_CODE (inner_type) == REAL_TYPE)
9260 return tree_expr_nonnegative_p (TREE_OPERAND (t,0));
9261 if (TREE_CODE (inner_type) == INTEGER_TYPE)
9262 return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
9263 && TYPE_UNSIGNED (inner_type);
9269 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
9270 && tree_expr_nonnegative_p (TREE_OPERAND (t, 2));
9272 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9274 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9275 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9277 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9278 || tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9280 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9282 return tree_expr_nonnegative_p (expr_last (TREE_OPERAND (t, 1)));
9284 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9285 case NON_LVALUE_EXPR:
9286 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9288 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9290 return rtl_expr_nonnegative_p (RTL_EXPR_RTL (t));
9294 tree temp = TARGET_EXPR_SLOT (t);
9295 t = TARGET_EXPR_INITIAL (t);
9297 /* If the initializer is non-void, then it's a normal expression
9298 that will be assigned to the slot. */
9299 if (!VOID_TYPE_P (t))
9300 return tree_expr_nonnegative_p (t);
9302 /* Otherwise, the initializer sets the slot in some way. One common
9303 way is an assignment statement at the end of the initializer. */
9306 if (TREE_CODE (t) == BIND_EXPR)
9307 t = expr_last (BIND_EXPR_BODY (t));
9308 else if (TREE_CODE (t) == TRY_FINALLY_EXPR
9309 || TREE_CODE (t) == TRY_CATCH_EXPR)
9310 t = expr_last (TREE_OPERAND (t, 0));
9311 else if (TREE_CODE (t) == STATEMENT_LIST)
9316 if (TREE_CODE (t) == MODIFY_EXPR
9317 && TREE_OPERAND (t, 0) == temp)
9318 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9325 tree fndecl = get_callee_fndecl (t);
9326 tree arglist = TREE_OPERAND (t, 1);
9328 && DECL_BUILT_IN (fndecl)
9329 && DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_MD)
9330 switch (DECL_FUNCTION_CODE (fndecl))
9332 #define CASE_BUILTIN_F(BUILT_IN_FN) \
9333 case BUILT_IN_FN: case BUILT_IN_FN##F: case BUILT_IN_FN##L:
9334 #define CASE_BUILTIN_I(BUILT_IN_FN) \
9335 case BUILT_IN_FN: case BUILT_IN_FN##L: case BUILT_IN_FN##LL:
9337 CASE_BUILTIN_F (BUILT_IN_ACOS)
9338 CASE_BUILTIN_F (BUILT_IN_ACOSH)
9339 CASE_BUILTIN_F (BUILT_IN_CABS)
9340 CASE_BUILTIN_F (BUILT_IN_COSH)
9341 CASE_BUILTIN_F (BUILT_IN_ERFC)
9342 CASE_BUILTIN_F (BUILT_IN_EXP)
9343 CASE_BUILTIN_F (BUILT_IN_EXP10)
9344 CASE_BUILTIN_F (BUILT_IN_EXP2)
9345 CASE_BUILTIN_F (BUILT_IN_FABS)
9346 CASE_BUILTIN_F (BUILT_IN_FDIM)
9347 CASE_BUILTIN_F (BUILT_IN_FREXP)
9348 CASE_BUILTIN_F (BUILT_IN_HYPOT)
9349 CASE_BUILTIN_F (BUILT_IN_POW10)
9350 CASE_BUILTIN_I (BUILT_IN_FFS)
9351 CASE_BUILTIN_I (BUILT_IN_PARITY)
9352 CASE_BUILTIN_I (BUILT_IN_POPCOUNT)
9356 CASE_BUILTIN_F (BUILT_IN_SQRT)
9357 /* sqrt(-0.0) is -0.0. */
9358 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (t))))
9360 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
9362 CASE_BUILTIN_F (BUILT_IN_ASINH)
9363 CASE_BUILTIN_F (BUILT_IN_ATAN)
9364 CASE_BUILTIN_F (BUILT_IN_ATANH)
9365 CASE_BUILTIN_F (BUILT_IN_CBRT)
9366 CASE_BUILTIN_F (BUILT_IN_CEIL)
9367 CASE_BUILTIN_F (BUILT_IN_ERF)
9368 CASE_BUILTIN_F (BUILT_IN_EXPM1)
9369 CASE_BUILTIN_F (BUILT_IN_FLOOR)
9370 CASE_BUILTIN_F (BUILT_IN_FMOD)
9371 CASE_BUILTIN_F (BUILT_IN_LDEXP)
9372 CASE_BUILTIN_F (BUILT_IN_LLRINT)
9373 CASE_BUILTIN_F (BUILT_IN_LLROUND)
9374 CASE_BUILTIN_F (BUILT_IN_LRINT)
9375 CASE_BUILTIN_F (BUILT_IN_LROUND)
9376 CASE_BUILTIN_F (BUILT_IN_MODF)
9377 CASE_BUILTIN_F (BUILT_IN_NEARBYINT)
9378 CASE_BUILTIN_F (BUILT_IN_POW)
9379 CASE_BUILTIN_F (BUILT_IN_RINT)
9380 CASE_BUILTIN_F (BUILT_IN_ROUND)
9381 CASE_BUILTIN_F (BUILT_IN_SIGNBIT)
9382 CASE_BUILTIN_F (BUILT_IN_SINH)
9383 CASE_BUILTIN_F (BUILT_IN_TANH)
9384 CASE_BUILTIN_F (BUILT_IN_TRUNC)
9385 /* True if the 1st argument is nonnegative. */
9386 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
9388 CASE_BUILTIN_F (BUILT_IN_FMAX)
9389 /* True if the 1st OR 2nd arguments are nonnegative. */
9390 return tree_expr_nonnegative_p (TREE_VALUE (arglist))
9391 || tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist)));
9393 CASE_BUILTIN_F (BUILT_IN_FMIN)
9394 /* True if the 1st AND 2nd arguments are nonnegative. */
9395 return tree_expr_nonnegative_p (TREE_VALUE (arglist))
9396 && tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist)));
9398 CASE_BUILTIN_F (BUILT_IN_COPYSIGN)
9399 /* True if the 2nd argument is nonnegative. */
9400 return tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist)));
9404 #undef CASE_BUILTIN_F
9405 #undef CASE_BUILTIN_I
9409 /* ... fall through ... */
9412 if (truth_value_p (TREE_CODE (t)))
9413 /* Truth values evaluate to 0 or 1, which is nonnegative. */
9417 /* We don't know sign of `t', so be conservative and return false. */
9421 /* Return true when T is an address and is known to be nonzero.
9422 For floating point we further ensure that T is not denormal.
9423 Similar logic is present in nonzero_address in rtlanal.h */
9426 tree_expr_nonzero_p (tree t)
9428 tree type = TREE_TYPE (t);
9430 /* Doing something useful for floating point would need more work. */
9431 if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
9434 switch (TREE_CODE (t))
9437 if (!TYPE_UNSIGNED (type) && !flag_wrapv)
9438 return tree_expr_nonzero_p (TREE_OPERAND (t, 0));
9441 return !integer_zerop (t);
9444 if (!TYPE_UNSIGNED (type) && !flag_wrapv)
9446 /* With the presence of negative values it is hard
9447 to say something. */
9448 if (!tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9449 || !tree_expr_nonnegative_p (TREE_OPERAND (t, 1)))
9451 /* One of operands must be positive and the other non-negative. */
9452 return (tree_expr_nonzero_p (TREE_OPERAND (t, 0))
9453 || tree_expr_nonzero_p (TREE_OPERAND (t, 1)));
9458 if (!TYPE_UNSIGNED (type) && !flag_wrapv)
9460 return (tree_expr_nonzero_p (TREE_OPERAND (t, 0))
9461 && tree_expr_nonzero_p (TREE_OPERAND (t, 1)));
9467 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
9468 tree outer_type = TREE_TYPE (t);
9470 return (TYPE_PRECISION (inner_type) >= TYPE_PRECISION (outer_type)
9471 && tree_expr_nonzero_p (TREE_OPERAND (t, 0)));
9476 /* Weak declarations may link to NULL. */
9477 if (DECL_P (TREE_OPERAND (t, 0)))
9478 return !DECL_WEAK (TREE_OPERAND (t, 0));
9479 /* Constants and all other cases are never weak. */
9483 return (tree_expr_nonzero_p (TREE_OPERAND (t, 1))
9484 && tree_expr_nonzero_p (TREE_OPERAND (t, 2)));
9487 return (tree_expr_nonzero_p (TREE_OPERAND (t, 0))
9488 && tree_expr_nonzero_p (TREE_OPERAND (t, 1)));
9491 if (tree_expr_nonzero_p (TREE_OPERAND (t, 0)))
9493 /* When both operands are nonzero, then MAX must be too. */
9494 if (tree_expr_nonzero_p (TREE_OPERAND (t, 1)))
9497 /* MAX where operand 0 is positive is positive. */
9498 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9500 /* MAX where operand 1 is positive is positive. */
9501 else if (tree_expr_nonzero_p (TREE_OPERAND (t, 1))
9502 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1)))
9509 return tree_expr_nonzero_p (TREE_OPERAND (t, 1));
9512 case NON_LVALUE_EXPR:
9513 return tree_expr_nonzero_p (TREE_OPERAND (t, 0));
9516 return tree_expr_nonzero_p (TREE_OPERAND (t, 1))
9517 || tree_expr_nonzero_p (TREE_OPERAND (t, 0));
9525 /* Return true if `r' is known to be non-negative.
9526 Only handles constants at the moment. */
9529 rtl_expr_nonnegative_p (rtx r)
9531 switch (GET_CODE (r))
9534 return INTVAL (r) >= 0;
9537 if (GET_MODE (r) == VOIDmode)
9538 return CONST_DOUBLE_HIGH (r) >= 0;
9546 units = CONST_VECTOR_NUNITS (r);
9548 for (i = 0; i < units; ++i)
9550 elt = CONST_VECTOR_ELT (r, i);
9551 if (!rtl_expr_nonnegative_p (elt))
9560 /* These are always nonnegative. */
9569 /* See if we are applying CODE, a relational to the highest or lowest
9570 possible integer of TYPE. If so, then the result is a compile
9574 fold_relational_hi_lo (enum tree_code *code_p, const tree type, tree *op0_p,
9579 enum tree_code code = *code_p;
9580 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (op1)));
9582 if (TREE_CODE (op1) == INTEGER_CST
9583 && ! TREE_CONSTANT_OVERFLOW (op1)
9584 && width <= HOST_BITS_PER_WIDE_INT
9585 && (INTEGRAL_TYPE_P (TREE_TYPE (op1))
9586 || POINTER_TYPE_P (TREE_TYPE (op1))))
9588 unsigned HOST_WIDE_INT signed_max;
9589 unsigned HOST_WIDE_INT max, min;
9591 signed_max = ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1;
9593 if (TYPE_UNSIGNED (TREE_TYPE (op1)))
9595 max = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
9601 min = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
9604 if (TREE_INT_CST_HIGH (op1) == 0
9605 && TREE_INT_CST_LOW (op1) == max)
9609 return omit_one_operand (type, integer_zero_node, op0);
9615 return omit_one_operand (type, integer_one_node, op0);
9621 /* The GE_EXPR and LT_EXPR cases above are not normally
9622 reached because of previous transformations. */
9627 else if (TREE_INT_CST_HIGH (op1) == 0
9628 && TREE_INT_CST_LOW (op1) == max - 1)
9633 *op1_p = const_binop (PLUS_EXPR, op1, integer_one_node, 0);
9637 *op1_p = const_binop (PLUS_EXPR, op1, integer_one_node, 0);
9642 else if (TREE_INT_CST_HIGH (op1) == (min ? -1 : 0)
9643 && TREE_INT_CST_LOW (op1) == min)
9647 return omit_one_operand (type, integer_zero_node, op0);
9654 return omit_one_operand (type, integer_one_node, op0);
9663 else if (TREE_INT_CST_HIGH (op1) == (min ? -1 : 0)
9664 && TREE_INT_CST_LOW (op1) == min + 1)
9669 *op1_p = const_binop (MINUS_EXPR, op1, integer_one_node, 0);
9673 *op1_p = const_binop (MINUS_EXPR, op1, integer_one_node, 0);
9679 else if (TREE_INT_CST_HIGH (op1) == 0
9680 && TREE_INT_CST_LOW (op1) == signed_max
9681 && TYPE_UNSIGNED (TREE_TYPE (op1))
9682 /* signed_type does not work on pointer types. */
9683 && INTEGRAL_TYPE_P (TREE_TYPE (op1)))
9685 /* The following case also applies to X < signed_max+1
9686 and X >= signed_max+1 because previous transformations. */
9687 if (code == LE_EXPR || code == GT_EXPR)
9689 tree st0, st1, exp, retval;
9690 st0 = lang_hooks.types.signed_type (TREE_TYPE (op0));
9691 st1 = lang_hooks.types.signed_type (TREE_TYPE (op1));
9693 exp = build2 (code == LE_EXPR ? GE_EXPR: LT_EXPR,
9695 fold_convert (st0, op0),
9696 fold_convert (st1, integer_zero_node));
9699 = nondestructive_fold_binary_to_constant (TREE_CODE (exp),
9701 TREE_OPERAND (exp, 0),
9702 TREE_OPERAND (exp, 1));
9704 /* If we are in gimple form, then returning EXP would create
9705 non-gimple expressions. Clearing it is safe and insures
9706 we do not allow a non-gimple expression to escape. */
9710 return (retval ? retval : exp);
9719 /* Given the components of a binary expression CODE, TYPE, OP0 and OP1,
9720 attempt to fold the expression to a constant without modifying TYPE,
9723 If the expression could be simplified to a constant, then return
9724 the constant. If the expression would not be simplified to a
9725 constant, then return NULL_TREE.
9727 Note this is primarily designed to be called after gimplification
9728 of the tree structures and when at least one operand is a constant.
9729 As a result of those simplifying assumptions this routine is far
9730 simpler than the generic fold routine. */
9733 nondestructive_fold_binary_to_constant (enum tree_code code, tree type,
9741 /* If this is a commutative operation, and ARG0 is a constant, move it
9742 to ARG1 to reduce the number of tests below. */
9743 if (commutative_tree_code (code)
9744 && (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST))
9751 /* If either operand is a complex type, extract its real component. */
9752 if (TREE_CODE (op0) == COMPLEX_CST)
9753 subop0 = TREE_REALPART (op0);
9757 if (TREE_CODE (op1) == COMPLEX_CST)
9758 subop1 = TREE_REALPART (op1);
9762 /* Note if either argument is not a real or integer constant.
9763 With a few exceptions, simplification is limited to cases
9764 where both arguments are constants. */
9765 if ((TREE_CODE (subop0) != INTEGER_CST
9766 && TREE_CODE (subop0) != REAL_CST)
9767 || (TREE_CODE (subop1) != INTEGER_CST
9768 && TREE_CODE (subop1) != REAL_CST))
9774 /* (plus (address) (const_int)) is a constant. */
9775 if (TREE_CODE (op0) == PLUS_EXPR
9776 && TREE_CODE (op1) == INTEGER_CST
9777 && (TREE_CODE (TREE_OPERAND (op0, 0)) == ADDR_EXPR
9778 || (TREE_CODE (TREE_OPERAND (op0, 0)) == NOP_EXPR
9779 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (op0, 0), 0))
9781 && TREE_CODE (TREE_OPERAND (op0, 1)) == INTEGER_CST)
9783 return build2 (PLUS_EXPR, type, TREE_OPERAND (op0, 0),
9784 const_binop (PLUS_EXPR, op1,
9785 TREE_OPERAND (op0, 1), 0));
9793 /* Both arguments are constants. Simplify. */
9794 tem = const_binop (code, op0, op1, 0);
9795 if (tem != NULL_TREE)
9797 /* The return value should always have the same type as
9798 the original expression. */
9799 if (TREE_TYPE (tem) != type)
9800 tem = fold_convert (type, tem);
9807 /* Fold &x - &x. This can happen from &x.foo - &x.
9808 This is unsafe for certain floats even in non-IEEE formats.
9809 In IEEE, it is unsafe because it does wrong for NaNs.
9810 Also note that operand_equal_p is always false if an
9811 operand is volatile. */
9812 if (! FLOAT_TYPE_P (type) && operand_equal_p (op0, op1, 0))
9813 return fold_convert (type, integer_zero_node);
9819 /* Special case multiplication or bitwise AND where one argument
9821 if (! FLOAT_TYPE_P (type) && integer_zerop (op1))
9822 return omit_one_operand (type, op1, op0);
9824 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (op0)))
9825 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (op0)))
9826 && real_zerop (op1))
9827 return omit_one_operand (type, op1, op0);
9832 /* Special case when we know the result will be all ones. */
9833 if (integer_all_onesp (op1))
9834 return omit_one_operand (type, op1, op0);
9838 case TRUNC_DIV_EXPR:
9839 case ROUND_DIV_EXPR:
9840 case FLOOR_DIV_EXPR:
9842 case EXACT_DIV_EXPR:
9843 case TRUNC_MOD_EXPR:
9844 case ROUND_MOD_EXPR:
9845 case FLOOR_MOD_EXPR:
9848 /* Division by zero is undefined. */
9849 if (integer_zerop (op1))
9852 if (TREE_CODE (op1) == REAL_CST
9853 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (op1)))
9854 && real_zerop (op1))
9860 if (INTEGRAL_TYPE_P (type)
9861 && operand_equal_p (op1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
9862 return omit_one_operand (type, op1, op0);
9867 if (INTEGRAL_TYPE_P (type)
9868 && TYPE_MAX_VALUE (type)
9869 && operand_equal_p (op1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
9870 return omit_one_operand (type, op1, op0);
9875 /* Optimize -1 >> x for arithmetic right shifts. */
9876 if (integer_all_onesp (op0) && ! TYPE_UNSIGNED (type))
9877 return omit_one_operand (type, op0, op1);
9878 /* ... fall through ... */
9881 if (integer_zerop (op0))
9882 return omit_one_operand (type, op0, op1);
9884 /* Since negative shift count is not well-defined, don't
9885 try to compute it in the compiler. */
9886 if (TREE_CODE (op1) == INTEGER_CST && tree_int_cst_sgn (op1) < 0)
9893 /* -1 rotated either direction by any amount is still -1. */
9894 if (integer_all_onesp (op0))
9895 return omit_one_operand (type, op0, op1);
9897 /* 0 rotated either direction by any amount is still zero. */
9898 if (integer_zerop (op0))
9899 return omit_one_operand (type, op0, op1);
9905 return build_complex (type, op0, op1);
9914 /* If one arg is a real or integer constant, put it last. */
9915 if ((TREE_CODE (op0) == INTEGER_CST
9916 && TREE_CODE (op1) != INTEGER_CST)
9917 || (TREE_CODE (op0) == REAL_CST
9918 && TREE_CODE (op0) != REAL_CST))
9925 code = swap_tree_comparison (code);
9928 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
9929 This transformation affects the cases which are handled in later
9930 optimizations involving comparisons with non-negative constants. */
9931 if (TREE_CODE (op1) == INTEGER_CST
9932 && TREE_CODE (op0) != INTEGER_CST
9933 && tree_int_cst_sgn (op1) > 0)
9939 op1 = const_binop (MINUS_EXPR, op1, integer_one_node, 0);
9944 op1 = const_binop (MINUS_EXPR, op1, integer_one_node, 0);
9952 tem = fold_relational_hi_lo (&code, type, &op0, &op1);
9959 case UNORDERED_EXPR:
9969 return fold_relational_const (code, type, op0, op1);
9972 /* This could probably be handled. */
9975 case TRUTH_AND_EXPR:
9976 /* If second arg is constant zero, result is zero, but first arg
9977 must be evaluated. */
9978 if (integer_zerop (op1))
9979 return omit_one_operand (type, op1, op0);
9980 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
9981 case will be handled here. */
9982 if (integer_zerop (op0))
9983 return omit_one_operand (type, op0, op1);
9984 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
9985 return constant_boolean_node (true, type);
9989 /* If second arg is constant true, result is true, but we must
9990 evaluate first arg. */
9991 if (TREE_CODE (op1) == INTEGER_CST && ! integer_zerop (op1))
9992 return omit_one_operand (type, op1, op0);
9993 /* Likewise for first arg, but note this only occurs here for
9995 if (TREE_CODE (op0) == INTEGER_CST && ! integer_zerop (op0))
9996 return omit_one_operand (type, op0, op1);
9997 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
9998 return constant_boolean_node (false, type);
10001 case TRUTH_XOR_EXPR:
10002 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
10004 int x = ! integer_zerop (op0) ^ ! integer_zerop (op1);
10005 return constant_boolean_node (x, type);
10014 /* Given the components of a unary expression CODE, TYPE and OP0,
10015 attempt to fold the expression to a constant without modifying
10018 If the expression could be simplified to a constant, then return
10019 the constant. If the expression would not be simplified to a
10020 constant, then return NULL_TREE.
10022 Note this is primarily designed to be called after gimplification
10023 of the tree structures and when op0 is a constant. As a result
10024 of those simplifying assumptions this routine is far simpler than
10025 the generic fold routine. */
10028 nondestructive_fold_unary_to_constant (enum tree_code code, tree type,
10031 /* Make sure we have a suitable constant argument. */
10032 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
10036 if (TREE_CODE (op0) == COMPLEX_CST)
10037 subop = TREE_REALPART (op0);
10041 if (TREE_CODE (subop) != INTEGER_CST && TREE_CODE (subop) != REAL_CST)
10050 case FIX_TRUNC_EXPR:
10051 case FIX_FLOOR_EXPR:
10052 case FIX_CEIL_EXPR:
10053 return fold_convert_const (code, type, op0);
10056 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
10057 return fold_negate_const (op0, type);
10062 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
10063 return fold_abs_const (op0, type);
10068 if (TREE_CODE (op0) == INTEGER_CST)
10069 return fold_not_const (op0, type);
10073 case REALPART_EXPR:
10074 if (TREE_CODE (op0) == COMPLEX_CST)
10075 return TREE_REALPART (op0);
10079 case IMAGPART_EXPR:
10080 if (TREE_CODE (op0) == COMPLEX_CST)
10081 return TREE_IMAGPART (op0);
10086 if (TREE_CODE (op0) == COMPLEX_CST
10087 && TREE_CODE (TREE_TYPE (op0)) == COMPLEX_TYPE)
10088 return build_complex (type, TREE_REALPART (op0),
10089 negate_expr (TREE_IMAGPART (op0)));
10097 /* If EXP represents referencing an element in a constant string
10098 (either via pointer arithmetic or array indexing), return the
10099 tree representing the value accessed, otherwise return NULL. */
10102 fold_read_from_constant_string (tree exp)
10104 if (TREE_CODE (exp) == INDIRECT_REF || TREE_CODE (exp) == ARRAY_REF)
10106 tree exp1 = TREE_OPERAND (exp, 0);
10110 if (TREE_CODE (exp) == INDIRECT_REF)
10111 string = string_constant (exp1, &index);
10114 tree low_bound = array_ref_low_bound (exp);
10115 index = fold_convert (sizetype, TREE_OPERAND (exp, 1));
10117 /* Optimize the special-case of a zero lower bound.
10119 We convert the low_bound to sizetype to avoid some problems
10120 with constant folding. (E.g. suppose the lower bound is 1,
10121 and its mode is QI. Without the conversion,l (ARRAY
10122 +(INDEX-(unsigned char)1)) becomes ((ARRAY+(-(unsigned char)1))
10123 +INDEX), which becomes (ARRAY+255+INDEX). Opps!) */
10124 if (! integer_zerop (low_bound))
10125 index = size_diffop (index, fold_convert (sizetype, low_bound));
10131 && TREE_TYPE (exp) == TREE_TYPE (TREE_TYPE (string))
10132 && TREE_CODE (string) == STRING_CST
10133 && TREE_CODE (index) == INTEGER_CST
10134 && compare_tree_int (index, TREE_STRING_LENGTH (string)) < 0
10135 && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (string))))
10137 && (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))) == 1))
10138 return fold_convert (TREE_TYPE (exp),
10139 build_int_2 ((TREE_STRING_POINTER (string)
10140 [TREE_INT_CST_LOW (index)]), 0));
10145 /* Return the tree for neg (ARG0) when ARG0 is known to be either
10146 an integer constant or real constant.
10148 TYPE is the type of the result. */
10151 fold_negate_const (tree arg0, tree type)
10153 tree t = NULL_TREE;
10155 if (TREE_CODE (arg0) == INTEGER_CST)
10157 unsigned HOST_WIDE_INT low;
10158 HOST_WIDE_INT high;
10159 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
10160 TREE_INT_CST_HIGH (arg0),
10162 t = build_int_2 (low, high);
10163 TREE_TYPE (t) = type;
10165 = (TREE_OVERFLOW (arg0)
10166 | force_fit_type (t, overflow && !TYPE_UNSIGNED (type)));
10167 TREE_CONSTANT_OVERFLOW (t)
10168 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
10170 else if (TREE_CODE (arg0) == REAL_CST)
10171 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
10172 #ifdef ENABLE_CHECKING
10180 /* Return the tree for abs (ARG0) when ARG0 is known to be either
10181 an integer constant or real constant.
10183 TYPE is the type of the result. */
10186 fold_abs_const (tree arg0, tree type)
10188 tree t = NULL_TREE;
10190 if (TREE_CODE (arg0) == INTEGER_CST)
10192 /* If the value is unsigned, then the absolute value is
10193 the same as the ordinary value. */
10194 if (TYPE_UNSIGNED (type))
10196 /* Similarly, if the value is non-negative. */
10197 else if (INT_CST_LT (integer_minus_one_node, arg0))
10199 /* If the value is negative, then the absolute value is
10203 unsigned HOST_WIDE_INT low;
10204 HOST_WIDE_INT high;
10205 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
10206 TREE_INT_CST_HIGH (arg0),
10208 t = build_int_2 (low, high);
10209 TREE_TYPE (t) = type;
10211 = (TREE_OVERFLOW (arg0)
10212 | force_fit_type (t, overflow));
10213 TREE_CONSTANT_OVERFLOW (t)
10214 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
10218 else if (TREE_CODE (arg0) == REAL_CST)
10220 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
10221 return build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
10225 #ifdef ENABLE_CHECKING
10233 /* Return the tree for not (ARG0) when ARG0 is known to be an integer
10234 constant. TYPE is the type of the result. */
10237 fold_not_const (tree arg0, tree type)
10239 tree t = NULL_TREE;
10241 if (TREE_CODE (arg0) == INTEGER_CST)
10243 t = build_int_2 (~ TREE_INT_CST_LOW (arg0),
10244 ~ TREE_INT_CST_HIGH (arg0));
10245 TREE_TYPE (t) = type;
10246 force_fit_type (t, 0);
10247 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg0);
10248 TREE_CONSTANT_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (arg0);
10250 #ifdef ENABLE_CHECKING
10258 /* Given CODE, a relational operator, the target type, TYPE and two
10259 constant operands OP0 and OP1, return the result of the
10260 relational operation. If the result is not a compile time
10261 constant, then return NULL_TREE. */
10264 fold_relational_const (enum tree_code code, tree type, tree op0, tree op1)
10266 int result, invert;
10268 /* From here on, the only cases we handle are when the result is
10269 known to be a constant. */
10271 if (TREE_CODE (op0) == REAL_CST && TREE_CODE (op1) == REAL_CST)
10273 /* Handle the cases where either operand is a NaN. */
10274 if (REAL_VALUE_ISNAN (TREE_REAL_CST (op0))
10275 || REAL_VALUE_ISNAN (TREE_REAL_CST (op1)))
10285 case UNORDERED_EXPR:
10299 if (flag_trapping_math)
10308 return constant_boolean_node (result, type);
10311 /* From here on we're sure there are no NaNs. */
10315 return constant_boolean_node (true, type);
10317 case UNORDERED_EXPR:
10318 return constant_boolean_node (false, type);
10344 /* From here on we only handle LT, LE, GT, GE, EQ and NE.
10346 To compute GT, swap the arguments and do LT.
10347 To compute GE, do LT and invert the result.
10348 To compute LE, swap the arguments, do LT and invert the result.
10349 To compute NE, do EQ and invert the result.
10351 Therefore, the code below must handle only EQ and LT. */
10353 if (code == LE_EXPR || code == GT_EXPR)
10358 code = swap_tree_comparison (code);
10361 /* Note that it is safe to invert for real values here because we
10362 have already handled the one case that it matters. */
10365 if (code == NE_EXPR || code == GE_EXPR)
10368 code = invert_tree_comparison (code, false);
10371 /* Compute a result for LT or EQ if args permit;
10372 Otherwise return T. */
10373 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
10375 if (code == EQ_EXPR)
10376 result = tree_int_cst_equal (op0, op1);
10377 else if (TYPE_UNSIGNED (TREE_TYPE (op0)))
10378 result = INT_CST_LT_UNSIGNED (op0, op1);
10380 result = INT_CST_LT (op0, op1);
10383 else if (code == EQ_EXPR && !TREE_SIDE_EFFECTS (op0)
10384 && integer_zerop (op1) && tree_expr_nonzero_p (op0))
10387 /* Two real constants can be compared explicitly. */
10388 else if (TREE_CODE (op0) == REAL_CST && TREE_CODE (op1) == REAL_CST)
10390 if (code == EQ_EXPR)
10391 result = REAL_VALUES_EQUAL (TREE_REAL_CST (op0),
10392 TREE_REAL_CST (op1));
10394 result = REAL_VALUES_LESS (TREE_REAL_CST (op0),
10395 TREE_REAL_CST (op1));
10402 return constant_boolean_node (result, type);
10405 /* Build an expression for the address of T. Folds away INDIRECT_REF to
10406 avoid confusing the gimplify process. */
10409 build_fold_addr_expr_with_type (tree t, tree ptrtype)
10411 if (TREE_CODE (t) == INDIRECT_REF)
10413 t = TREE_OPERAND (t, 0);
10414 if (TREE_TYPE (t) != ptrtype)
10415 t = build1 (NOP_EXPR, ptrtype, t);
10420 while (TREE_CODE (base) == COMPONENT_REF
10421 || TREE_CODE (base) == ARRAY_REF)
10422 base = TREE_OPERAND (base, 0);
10424 TREE_ADDRESSABLE (base) = 1;
10426 t = build1 (ADDR_EXPR, ptrtype, t);
10433 build_fold_addr_expr (tree t)
10435 return build_fold_addr_expr_with_type (t, build_pointer_type (TREE_TYPE (t)));
10438 /* Builds an expression for an indirection through T, simplifying some
10442 build_fold_indirect_ref (tree t)
10444 tree type = TREE_TYPE (TREE_TYPE (t));
10449 if (TREE_CODE (sub) == ADDR_EXPR)
10451 tree op = TREE_OPERAND (sub, 0);
10452 tree optype = TREE_TYPE (op);
10454 if (lang_hooks.types_compatible_p (type, optype))
10456 /* *(foo *)&fooarray => fooarray[0] */
10457 else if (TREE_CODE (optype) == ARRAY_TYPE
10458 && lang_hooks.types_compatible_p (type, TREE_TYPE (optype)))
10459 return build4 (ARRAY_REF, type, op, size_zero_node, NULL_TREE, NULL_TREE);
10462 /* *(foo *)fooarrptr => (*fooarrptr)[0] */
10463 subtype = TREE_TYPE (sub);
10464 if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE
10465 && lang_hooks.types_compatible_p (type, TREE_TYPE (TREE_TYPE (subtype))))
10467 sub = build_fold_indirect_ref (sub);
10468 return build4 (ARRAY_REF, type, sub, size_zero_node, NULL_TREE, NULL_TREE);
10471 return build1 (INDIRECT_REF, type, t);
10474 #include "gt-fold-const.h"