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 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
22 /*@@ This file should be rewritten to use an arbitrary precision
23 @@ representation for "struct tree_int_cst" and "struct tree_real_cst".
24 @@ Perhaps the routines could also be used for bc/dc, and made a lib.
25 @@ The routines that translate from the ap rep should
26 @@ warn if precision et. al. is lost.
27 @@ This would also make life easier when this technology is used
28 @@ for cross-compilers. */
30 /* The entry points in this file are fold, size_int_wide, size_binop
33 fold takes a tree as argument and returns a simplified tree.
35 size_binop takes a tree code for an arithmetic operation
36 and two operands that are trees, and produces a tree for the
37 result, assuming the type comes from `sizetype'.
39 size_int takes an integer value, and creates a tree constant
40 with type from `sizetype'.
42 force_fit_type takes a constant and prior overflow indicator, and
43 forces the value to fit the type. It returns an overflow indicator. */
47 #include "coretypes.h"
58 #include "langhooks.h"
61 static void encode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT, HOST_WIDE_INT);
62 static void decode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
63 static bool negate_expr_p (tree);
64 static tree negate_expr (tree);
65 static tree split_tree (tree, enum tree_code, tree *, tree *, tree *, int);
66 static tree associate_trees (tree, tree, enum tree_code, tree);
67 static tree int_const_binop (enum tree_code, tree, tree, int);
68 static tree const_binop (enum tree_code, tree, tree, int);
69 static hashval_t size_htab_hash (const void *);
70 static int size_htab_eq (const void *, const void *);
71 static tree fold_convert (tree, tree);
72 static enum tree_code invert_tree_comparison (enum tree_code);
73 static enum tree_code swap_tree_comparison (enum tree_code);
74 static int comparison_to_compcode (enum tree_code);
75 static enum tree_code compcode_to_comparison (int);
76 static int truth_value_p (enum tree_code);
77 static int operand_equal_for_comparison_p (tree, tree, tree);
78 static int twoval_comparison_p (tree, tree *, tree *, int *);
79 static tree eval_subst (tree, tree, tree, tree, tree);
80 static tree pedantic_omit_one_operand (tree, tree, tree);
81 static tree distribute_bit_expr (enum tree_code, tree, tree, tree);
82 static tree make_bit_field_ref (tree, tree, int, int, int);
83 static tree optimize_bit_field_compare (enum tree_code, tree, tree, tree);
84 static tree decode_field_reference (tree, HOST_WIDE_INT *, HOST_WIDE_INT *,
85 enum machine_mode *, int *, int *,
87 static int all_ones_mask_p (tree, int);
88 static tree sign_bit_p (tree, tree);
89 static int simple_operand_p (tree);
90 static tree range_binop (enum tree_code, tree, tree, int, tree, int);
91 static tree make_range (tree, int *, tree *, tree *);
92 static tree build_range_check (tree, tree, int, tree, tree);
93 static int merge_ranges (int *, tree *, tree *, int, tree, tree, int, tree,
95 static tree fold_range_test (tree);
96 static tree unextend (tree, int, int, tree);
97 static tree fold_truthop (enum tree_code, tree, tree, tree);
98 static tree optimize_minmax_comparison (tree);
99 static tree extract_muldiv (tree, tree, enum tree_code, tree);
100 static tree extract_muldiv_1 (tree, tree, enum tree_code, tree);
101 static tree strip_compound_expr (tree, tree);
102 static int multiple_of_p (tree, tree, tree);
103 static tree constant_boolean_node (int, tree);
104 static int count_cond (tree, int);
105 static tree fold_binary_op_with_conditional_arg (enum tree_code, tree, tree,
107 static bool fold_real_zero_addition_p (tree, tree, int);
108 static tree fold_mathfn_compare (enum built_in_function, enum tree_code,
110 static tree fold_inf_compare (enum tree_code, tree, tree, tree);
111 static bool tree_swap_operands_p (tree, tree);
113 /* The following constants represent a bit based encoding of GCC's
114 comparison operators. This encoding simplifies transformations
115 on relational comparison operators, such as AND and OR. */
116 #define COMPCODE_FALSE 0
117 #define COMPCODE_LT 1
118 #define COMPCODE_EQ 2
119 #define COMPCODE_LE 3
120 #define COMPCODE_GT 4
121 #define COMPCODE_NE 5
122 #define COMPCODE_GE 6
123 #define COMPCODE_TRUE 7
125 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
126 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
127 and SUM1. Then this yields nonzero if overflow occurred during the
130 Overflow occurs if A and B have the same sign, but A and SUM differ in
131 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
133 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
135 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
136 We do that by representing the two-word integer in 4 words, with only
137 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
138 number. The value of the word is LOWPART + HIGHPART * BASE. */
141 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
142 #define HIGHPART(x) \
143 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
144 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
146 /* Unpack a two-word integer into 4 words.
147 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
148 WORDS points to the array of HOST_WIDE_INTs. */
151 encode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT low, HOST_WIDE_INT hi)
153 words[0] = LOWPART (low);
154 words[1] = HIGHPART (low);
155 words[2] = LOWPART (hi);
156 words[3] = HIGHPART (hi);
159 /* Pack an array of 4 words into a two-word integer.
160 WORDS points to the array of words.
161 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
164 decode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT *low,
167 *low = words[0] + words[1] * BASE;
168 *hi = words[2] + words[3] * BASE;
171 /* Make the integer constant T valid for its type by setting to 0 or 1 all
172 the bits in the constant that don't belong in the type.
174 Return 1 if a signed overflow occurs, 0 otherwise. If OVERFLOW is
175 nonzero, a signed overflow has already occurred in calculating T, so
179 force_fit_type (tree t, int overflow)
181 unsigned HOST_WIDE_INT low;
185 if (TREE_CODE (t) == REAL_CST)
187 /* ??? Used to check for overflow here via CHECK_FLOAT_TYPE.
188 Consider doing it via real_convert now. */
192 else if (TREE_CODE (t) != INTEGER_CST)
195 low = TREE_INT_CST_LOW (t);
196 high = TREE_INT_CST_HIGH (t);
198 if (POINTER_TYPE_P (TREE_TYPE (t))
199 || TREE_CODE (TREE_TYPE (t)) == OFFSET_TYPE)
202 prec = TYPE_PRECISION (TREE_TYPE (t));
204 /* First clear all bits that are beyond the type's precision. */
206 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
208 else if (prec > HOST_BITS_PER_WIDE_INT)
209 TREE_INT_CST_HIGH (t)
210 &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
213 TREE_INT_CST_HIGH (t) = 0;
214 if (prec < HOST_BITS_PER_WIDE_INT)
215 TREE_INT_CST_LOW (t) &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
218 /* Unsigned types do not suffer sign extension or overflow unless they
220 if (TREE_UNSIGNED (TREE_TYPE (t))
221 && ! (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
222 && TYPE_IS_SIZETYPE (TREE_TYPE (t))))
225 /* If the value's sign bit is set, extend the sign. */
226 if (prec != 2 * HOST_BITS_PER_WIDE_INT
227 && (prec > HOST_BITS_PER_WIDE_INT
228 ? 0 != (TREE_INT_CST_HIGH (t)
230 << (prec - HOST_BITS_PER_WIDE_INT - 1)))
231 : 0 != (TREE_INT_CST_LOW (t)
232 & ((unsigned HOST_WIDE_INT) 1 << (prec - 1)))))
234 /* Value is negative:
235 set to 1 all the bits that are outside this type's precision. */
236 if (prec > HOST_BITS_PER_WIDE_INT)
237 TREE_INT_CST_HIGH (t)
238 |= ((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
241 TREE_INT_CST_HIGH (t) = -1;
242 if (prec < HOST_BITS_PER_WIDE_INT)
243 TREE_INT_CST_LOW (t) |= ((unsigned HOST_WIDE_INT) (-1) << prec);
247 /* Return nonzero if signed overflow occurred. */
249 ((overflow | (low ^ TREE_INT_CST_LOW (t)) | (high ^ TREE_INT_CST_HIGH (t)))
253 /* Add two doubleword integers with doubleword result.
254 Each argument is given as two `HOST_WIDE_INT' pieces.
255 One argument is L1 and H1; the other, L2 and H2.
256 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
259 add_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
260 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
261 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
263 unsigned HOST_WIDE_INT l;
267 h = h1 + h2 + (l < l1);
271 return OVERFLOW_SUM_SIGN (h1, h2, h);
274 /* Negate a doubleword integer with doubleword result.
275 Return nonzero if the operation overflows, assuming it's signed.
276 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
277 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
280 neg_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
281 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
287 return (*hv & h1) < 0;
297 /* Multiply two doubleword integers with doubleword result.
298 Return nonzero if the operation overflows, assuming it's signed.
299 Each argument is given as two `HOST_WIDE_INT' pieces.
300 One argument is L1 and H1; the other, L2 and H2.
301 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
304 mul_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
305 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
306 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
308 HOST_WIDE_INT arg1[4];
309 HOST_WIDE_INT arg2[4];
310 HOST_WIDE_INT prod[4 * 2];
311 unsigned HOST_WIDE_INT carry;
313 unsigned HOST_WIDE_INT toplow, neglow;
314 HOST_WIDE_INT tophigh, neghigh;
316 encode (arg1, l1, h1);
317 encode (arg2, l2, h2);
319 memset (prod, 0, sizeof prod);
321 for (i = 0; i < 4; i++)
324 for (j = 0; j < 4; j++)
327 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
328 carry += arg1[i] * arg2[j];
329 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
331 prod[k] = LOWPART (carry);
332 carry = HIGHPART (carry);
337 decode (prod, lv, hv); /* This ignores prod[4] through prod[4*2-1] */
339 /* Check for overflow by calculating the top half of the answer in full;
340 it should agree with the low half's sign bit. */
341 decode (prod + 4, &toplow, &tophigh);
344 neg_double (l2, h2, &neglow, &neghigh);
345 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
349 neg_double (l1, h1, &neglow, &neghigh);
350 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
352 return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
355 /* Shift the doubleword integer in L1, H1 left by COUNT places
356 keeping only PREC bits of result.
357 Shift right if COUNT is negative.
358 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
359 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
362 lshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
363 HOST_WIDE_INT count, unsigned int prec,
364 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv, int arith)
366 unsigned HOST_WIDE_INT signmask;
370 rshift_double (l1, h1, -count, prec, lv, hv, arith);
374 #ifdef SHIFT_COUNT_TRUNCATED
375 if (SHIFT_COUNT_TRUNCATED)
379 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
381 /* Shifting by the host word size is undefined according to the
382 ANSI standard, so we must handle this as a special case. */
386 else if (count >= HOST_BITS_PER_WIDE_INT)
388 *hv = l1 << (count - HOST_BITS_PER_WIDE_INT);
393 *hv = (((unsigned HOST_WIDE_INT) h1 << count)
394 | (l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
398 /* Sign extend all bits that are beyond the precision. */
400 signmask = -((prec > HOST_BITS_PER_WIDE_INT
401 ? ((unsigned HOST_WIDE_INT) *hv
402 >> (prec - HOST_BITS_PER_WIDE_INT - 1))
403 : (*lv >> (prec - 1))) & 1);
405 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
407 else if (prec >= HOST_BITS_PER_WIDE_INT)
409 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
410 *hv |= signmask << (prec - HOST_BITS_PER_WIDE_INT);
415 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
416 *lv |= signmask << prec;
420 /* Shift the doubleword integer in L1, H1 right by COUNT places
421 keeping only PREC bits of result. COUNT must be positive.
422 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
423 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
426 rshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
427 HOST_WIDE_INT count, unsigned int prec,
428 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
431 unsigned HOST_WIDE_INT signmask;
434 ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
437 #ifdef SHIFT_COUNT_TRUNCATED
438 if (SHIFT_COUNT_TRUNCATED)
442 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
444 /* Shifting by the host word size is undefined according to the
445 ANSI standard, so we must handle this as a special case. */
449 else if (count >= HOST_BITS_PER_WIDE_INT)
452 *lv = (unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT);
456 *hv = (unsigned HOST_WIDE_INT) h1 >> count;
458 | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
461 /* Zero / sign extend all bits that are beyond the precision. */
463 if (count >= (HOST_WIDE_INT)prec)
468 else if ((prec - count) >= 2 * HOST_BITS_PER_WIDE_INT)
470 else if ((prec - count) >= HOST_BITS_PER_WIDE_INT)
472 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - count - HOST_BITS_PER_WIDE_INT));
473 *hv |= signmask << (prec - count - HOST_BITS_PER_WIDE_INT);
478 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << (prec - count));
479 *lv |= signmask << (prec - count);
483 /* Rotate the doubleword integer in L1, H1 left by COUNT places
484 keeping only PREC bits of result.
485 Rotate right if COUNT is negative.
486 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
489 lrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
490 HOST_WIDE_INT count, unsigned int prec,
491 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
493 unsigned HOST_WIDE_INT s1l, s2l;
494 HOST_WIDE_INT s1h, s2h;
500 lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
501 rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
506 /* Rotate the doubleword integer in L1, H1 left by COUNT places
507 keeping only PREC bits of result. COUNT must be positive.
508 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
511 rrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
512 HOST_WIDE_INT count, unsigned int prec,
513 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
515 unsigned HOST_WIDE_INT s1l, s2l;
516 HOST_WIDE_INT s1h, s2h;
522 rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
523 lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
528 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
529 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
530 CODE is a tree code for a kind of division, one of
531 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
533 It controls how the quotient is rounded to an integer.
534 Return nonzero if the operation overflows.
535 UNS nonzero says do unsigned division. */
538 div_and_round_double (enum tree_code code, int uns,
539 unsigned HOST_WIDE_INT lnum_orig, /* num == numerator == dividend */
540 HOST_WIDE_INT hnum_orig,
541 unsigned HOST_WIDE_INT lden_orig, /* den == denominator == divisor */
542 HOST_WIDE_INT hden_orig,
543 unsigned HOST_WIDE_INT *lquo,
544 HOST_WIDE_INT *hquo, unsigned HOST_WIDE_INT *lrem,
548 HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
549 HOST_WIDE_INT den[4], quo[4];
551 unsigned HOST_WIDE_INT work;
552 unsigned HOST_WIDE_INT carry = 0;
553 unsigned HOST_WIDE_INT lnum = lnum_orig;
554 HOST_WIDE_INT hnum = hnum_orig;
555 unsigned HOST_WIDE_INT lden = lden_orig;
556 HOST_WIDE_INT hden = hden_orig;
559 if (hden == 0 && lden == 0)
560 overflow = 1, lden = 1;
562 /* Calculate quotient sign and convert operands to unsigned. */
568 /* (minimum integer) / (-1) is the only overflow case. */
569 if (neg_double (lnum, hnum, &lnum, &hnum)
570 && ((HOST_WIDE_INT) lden & hden) == -1)
576 neg_double (lden, hden, &lden, &hden);
580 if (hnum == 0 && hden == 0)
581 { /* single precision */
583 /* This unsigned division rounds toward zero. */
589 { /* trivial case: dividend < divisor */
590 /* hden != 0 already checked. */
597 memset (quo, 0, sizeof quo);
599 memset (num, 0, sizeof num); /* to zero 9th element */
600 memset (den, 0, sizeof den);
602 encode (num, lnum, hnum);
603 encode (den, lden, hden);
605 /* Special code for when the divisor < BASE. */
606 if (hden == 0 && lden < (unsigned HOST_WIDE_INT) BASE)
608 /* hnum != 0 already checked. */
609 for (i = 4 - 1; i >= 0; i--)
611 work = num[i] + carry * BASE;
612 quo[i] = work / lden;
618 /* Full double precision division,
619 with thanks to Don Knuth's "Seminumerical Algorithms". */
620 int num_hi_sig, den_hi_sig;
621 unsigned HOST_WIDE_INT quo_est, scale;
623 /* Find the highest nonzero divisor digit. */
624 for (i = 4 - 1;; i--)
631 /* Insure that the first digit of the divisor is at least BASE/2.
632 This is required by the quotient digit estimation algorithm. */
634 scale = BASE / (den[den_hi_sig] + 1);
636 { /* scale divisor and dividend */
638 for (i = 0; i <= 4 - 1; i++)
640 work = (num[i] * scale) + carry;
641 num[i] = LOWPART (work);
642 carry = HIGHPART (work);
647 for (i = 0; i <= 4 - 1; i++)
649 work = (den[i] * scale) + carry;
650 den[i] = LOWPART (work);
651 carry = HIGHPART (work);
652 if (den[i] != 0) den_hi_sig = i;
659 for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--)
661 /* Guess the next quotient digit, quo_est, by dividing the first
662 two remaining dividend digits by the high order quotient digit.
663 quo_est is never low and is at most 2 high. */
664 unsigned HOST_WIDE_INT tmp;
666 num_hi_sig = i + den_hi_sig + 1;
667 work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
668 if (num[num_hi_sig] != den[den_hi_sig])
669 quo_est = work / den[den_hi_sig];
673 /* Refine quo_est so it's usually correct, and at most one high. */
674 tmp = work - quo_est * den[den_hi_sig];
676 && (den[den_hi_sig - 1] * quo_est
677 > (tmp * BASE + num[num_hi_sig - 2])))
680 /* Try QUO_EST as the quotient digit, by multiplying the
681 divisor by QUO_EST and subtracting from the remaining dividend.
682 Keep in mind that QUO_EST is the I - 1st digit. */
685 for (j = 0; j <= den_hi_sig; j++)
687 work = quo_est * den[j] + carry;
688 carry = HIGHPART (work);
689 work = num[i + j] - LOWPART (work);
690 num[i + j] = LOWPART (work);
691 carry += HIGHPART (work) != 0;
694 /* If quo_est was high by one, then num[i] went negative and
695 we need to correct things. */
696 if (num[num_hi_sig] < (HOST_WIDE_INT) carry)
699 carry = 0; /* add divisor back in */
700 for (j = 0; j <= den_hi_sig; j++)
702 work = num[i + j] + den[j] + carry;
703 carry = HIGHPART (work);
704 num[i + j] = LOWPART (work);
707 num [num_hi_sig] += carry;
710 /* Store the quotient digit. */
715 decode (quo, lquo, hquo);
718 /* If result is negative, make it so. */
720 neg_double (*lquo, *hquo, lquo, hquo);
722 /* compute trial remainder: rem = num - (quo * den) */
723 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
724 neg_double (*lrem, *hrem, lrem, hrem);
725 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
730 case TRUNC_MOD_EXPR: /* round toward zero */
731 case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
735 case FLOOR_MOD_EXPR: /* round toward negative infinity */
736 if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
739 add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
747 case CEIL_MOD_EXPR: /* round toward positive infinity */
748 if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
750 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
758 case ROUND_MOD_EXPR: /* round to closest integer */
760 unsigned HOST_WIDE_INT labs_rem = *lrem;
761 HOST_WIDE_INT habs_rem = *hrem;
762 unsigned HOST_WIDE_INT labs_den = lden, ltwice;
763 HOST_WIDE_INT habs_den = hden, htwice;
765 /* Get absolute values. */
767 neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
769 neg_double (lden, hden, &labs_den, &habs_den);
771 /* If (2 * abs (lrem) >= abs (lden)) */
772 mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
773 labs_rem, habs_rem, <wice, &htwice);
775 if (((unsigned HOST_WIDE_INT) habs_den
776 < (unsigned HOST_WIDE_INT) htwice)
777 || (((unsigned HOST_WIDE_INT) habs_den
778 == (unsigned HOST_WIDE_INT) htwice)
779 && (labs_den < ltwice)))
783 add_double (*lquo, *hquo,
784 (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
787 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
799 /* compute true remainder: rem = num - (quo * den) */
800 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
801 neg_double (*lrem, *hrem, lrem, hrem);
802 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
806 /* Determine whether an expression T can be cheaply negated using
807 the function negate_expr. */
810 negate_expr_p (tree t)
812 unsigned HOST_WIDE_INT val;
819 type = TREE_TYPE (t);
822 switch (TREE_CODE (t))
825 if (TREE_UNSIGNED (type))
828 /* Check that -CST will not overflow type. */
829 prec = TYPE_PRECISION (type);
830 if (prec > HOST_BITS_PER_WIDE_INT)
832 if (TREE_INT_CST_LOW (t) != 0)
834 prec -= HOST_BITS_PER_WIDE_INT;
835 val = TREE_INT_CST_HIGH (t);
838 val = TREE_INT_CST_LOW (t);
839 if (prec < HOST_BITS_PER_WIDE_INT)
840 val &= ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
841 return val != ((unsigned HOST_WIDE_INT) 1 << (prec - 1));
848 /* We can't turn -(A-B) into B-A when we honor signed zeros. */
849 return ! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations;
852 if (TREE_UNSIGNED (TREE_TYPE (t)))
858 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
859 return negate_expr_p (TREE_OPERAND (t, 1))
860 || negate_expr_p (TREE_OPERAND (t, 0));
869 /* Given T, an expression, return the negation of T. Allow for T to be
870 null, in which case return null. */
881 type = TREE_TYPE (t);
884 switch (TREE_CODE (t))
887 if (! TREE_UNSIGNED (type)
888 && 0 != (tem = fold (build1 (NEGATE_EXPR, type, t)))
889 && ! TREE_OVERFLOW (tem))
894 tem = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (t)));
895 /* Two's complement FP formats, such as c4x, may overflow. */
896 if (! TREE_OVERFLOW (tem))
897 return convert (type, tem);
901 return convert (type, TREE_OPERAND (t, 0));
904 /* - (A - B) -> B - A */
905 if (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
906 return convert (type,
907 fold (build (MINUS_EXPR, TREE_TYPE (t),
909 TREE_OPERAND (t, 0))));
913 if (TREE_UNSIGNED (TREE_TYPE (t)))
919 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
921 tem = TREE_OPERAND (t, 1);
922 if (negate_expr_p (tem))
923 return convert (type,
924 fold (build (TREE_CODE (t), TREE_TYPE (t),
926 negate_expr (tem))));
927 tem = TREE_OPERAND (t, 0);
928 if (negate_expr_p (tem))
929 return convert (type,
930 fold (build (TREE_CODE (t), TREE_TYPE (t),
932 TREE_OPERAND (t, 1))));
940 return convert (type, fold (build1 (NEGATE_EXPR, TREE_TYPE (t), t)));
943 /* Split a tree IN into a constant, literal and variable parts that could be
944 combined with CODE to make IN. "constant" means an expression with
945 TREE_CONSTANT but that isn't an actual constant. CODE must be a
946 commutative arithmetic operation. Store the constant part into *CONP,
947 the literal in *LITP and return the variable part. If a part isn't
948 present, set it to null. If the tree does not decompose in this way,
949 return the entire tree as the variable part and the other parts as null.
951 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
952 case, we negate an operand that was subtracted. Except if it is a
953 literal for which we use *MINUS_LITP instead.
955 If NEGATE_P is true, we are negating all of IN, again except a literal
956 for which we use *MINUS_LITP instead.
958 If IN is itself a literal or constant, return it as appropriate.
960 Note that we do not guarantee that any of the three values will be the
961 same type as IN, but they will have the same signedness and mode. */
964 split_tree (tree in, enum tree_code code, tree *conp, tree *litp,
965 tree *minus_litp, int negate_p)
973 /* Strip any conversions that don't change the machine mode or signedness. */
974 STRIP_SIGN_NOPS (in);
976 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST)
978 else if (TREE_CODE (in) == code
979 || (! FLOAT_TYPE_P (TREE_TYPE (in))
980 /* We can associate addition and subtraction together (even
981 though the C standard doesn't say so) for integers because
982 the value is not affected. For reals, the value might be
983 affected, so we can't. */
984 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
985 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
987 tree op0 = TREE_OPERAND (in, 0);
988 tree op1 = TREE_OPERAND (in, 1);
989 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
990 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
992 /* First see if either of the operands is a literal, then a constant. */
993 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
994 *litp = op0, op0 = 0;
995 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST)
996 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
998 if (op0 != 0 && TREE_CONSTANT (op0))
999 *conp = op0, op0 = 0;
1000 else if (op1 != 0 && TREE_CONSTANT (op1))
1001 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
1003 /* If we haven't dealt with either operand, this is not a case we can
1004 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1005 if (op0 != 0 && op1 != 0)
1010 var = op1, neg_var_p = neg1_p;
1012 /* Now do any needed negations. */
1014 *minus_litp = *litp, *litp = 0;
1016 *conp = negate_expr (*conp);
1018 var = negate_expr (var);
1020 else if (TREE_CONSTANT (in))
1028 *minus_litp = *litp, *litp = 0;
1029 else if (*minus_litp)
1030 *litp = *minus_litp, *minus_litp = 0;
1031 *conp = negate_expr (*conp);
1032 var = negate_expr (var);
1038 /* Re-associate trees split by the above function. T1 and T2 are either
1039 expressions to associate or null. Return the new expression, if any. If
1040 we build an operation, do it in TYPE and with CODE. */
1043 associate_trees (tree t1, tree t2, enum tree_code code, tree type)
1050 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1051 try to fold this since we will have infinite recursion. But do
1052 deal with any NEGATE_EXPRs. */
1053 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
1054 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1056 if (code == PLUS_EXPR)
1058 if (TREE_CODE (t1) == NEGATE_EXPR)
1059 return build (MINUS_EXPR, type, convert (type, t2),
1060 convert (type, TREE_OPERAND (t1, 0)));
1061 else if (TREE_CODE (t2) == NEGATE_EXPR)
1062 return build (MINUS_EXPR, type, convert (type, t1),
1063 convert (type, TREE_OPERAND (t2, 0)));
1065 return build (code, type, convert (type, t1), convert (type, t2));
1068 return fold (build (code, type, convert (type, t1), convert (type, t2)));
1071 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1072 to produce a new constant.
1074 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1077 int_const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1079 unsigned HOST_WIDE_INT int1l, int2l;
1080 HOST_WIDE_INT int1h, int2h;
1081 unsigned HOST_WIDE_INT low;
1083 unsigned HOST_WIDE_INT garbagel;
1084 HOST_WIDE_INT garbageh;
1086 tree type = TREE_TYPE (arg1);
1087 int uns = TREE_UNSIGNED (type);
1089 = (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type));
1091 int no_overflow = 0;
1093 int1l = TREE_INT_CST_LOW (arg1);
1094 int1h = TREE_INT_CST_HIGH (arg1);
1095 int2l = TREE_INT_CST_LOW (arg2);
1096 int2h = TREE_INT_CST_HIGH (arg2);
1101 low = int1l | int2l, hi = int1h | int2h;
1105 low = int1l ^ int2l, hi = int1h ^ int2h;
1109 low = int1l & int2l, hi = int1h & int2h;
1115 /* It's unclear from the C standard whether shifts can overflow.
1116 The following code ignores overflow; perhaps a C standard
1117 interpretation ruling is needed. */
1118 lshift_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1126 lrotate_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1131 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1135 neg_double (int2l, int2h, &low, &hi);
1136 add_double (int1l, int1h, low, hi, &low, &hi);
1137 overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
1141 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1144 case TRUNC_DIV_EXPR:
1145 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1146 case EXACT_DIV_EXPR:
1147 /* This is a shortcut for a common special case. */
1148 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1149 && ! TREE_CONSTANT_OVERFLOW (arg1)
1150 && ! TREE_CONSTANT_OVERFLOW (arg2)
1151 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1153 if (code == CEIL_DIV_EXPR)
1156 low = int1l / int2l, hi = 0;
1160 /* ... fall through ... */
1162 case ROUND_DIV_EXPR:
1163 if (int2h == 0 && int2l == 1)
1165 low = int1l, hi = int1h;
1168 if (int1l == int2l && int1h == int2h
1169 && ! (int1l == 0 && int1h == 0))
1174 overflow = div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
1175 &low, &hi, &garbagel, &garbageh);
1178 case TRUNC_MOD_EXPR:
1179 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1180 /* This is a shortcut for a common special case. */
1181 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1182 && ! TREE_CONSTANT_OVERFLOW (arg1)
1183 && ! TREE_CONSTANT_OVERFLOW (arg2)
1184 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1186 if (code == CEIL_MOD_EXPR)
1188 low = int1l % int2l, hi = 0;
1192 /* ... fall through ... */
1194 case ROUND_MOD_EXPR:
1195 overflow = div_and_round_double (code, uns,
1196 int1l, int1h, int2l, int2h,
1197 &garbagel, &garbageh, &low, &hi);
1203 low = (((unsigned HOST_WIDE_INT) int1h
1204 < (unsigned HOST_WIDE_INT) int2h)
1205 || (((unsigned HOST_WIDE_INT) int1h
1206 == (unsigned HOST_WIDE_INT) int2h)
1209 low = (int1h < int2h
1210 || (int1h == int2h && int1l < int2l));
1212 if (low == (code == MIN_EXPR))
1213 low = int1l, hi = int1h;
1215 low = int2l, hi = int2h;
1222 /* If this is for a sizetype, can be represented as one (signed)
1223 HOST_WIDE_INT word, and doesn't overflow, use size_int since it caches
1226 && ((hi == 0 && (HOST_WIDE_INT) low >= 0)
1227 || (hi == -1 && (HOST_WIDE_INT) low < 0))
1228 && overflow == 0 && ! TREE_OVERFLOW (arg1) && ! TREE_OVERFLOW (arg2))
1229 return size_int_type_wide (low, type);
1232 t = build_int_2 (low, hi);
1233 TREE_TYPE (t) = TREE_TYPE (arg1);
1238 ? (!uns || is_sizetype) && overflow
1239 : (force_fit_type (t, (!uns || is_sizetype) && overflow)
1241 | TREE_OVERFLOW (arg1)
1242 | TREE_OVERFLOW (arg2));
1244 /* If we're doing a size calculation, unsigned arithmetic does overflow.
1245 So check if force_fit_type truncated the value. */
1247 && ! TREE_OVERFLOW (t)
1248 && (TREE_INT_CST_HIGH (t) != hi
1249 || TREE_INT_CST_LOW (t) != low))
1250 TREE_OVERFLOW (t) = 1;
1252 TREE_CONSTANT_OVERFLOW (t) = (TREE_OVERFLOW (t)
1253 | TREE_CONSTANT_OVERFLOW (arg1)
1254 | TREE_CONSTANT_OVERFLOW (arg2));
1258 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1259 constant. We assume ARG1 and ARG2 have the same data type, or at least
1260 are the same kind of constant and the same machine mode.
1262 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1265 const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1270 if (TREE_CODE (arg1) == INTEGER_CST)
1271 return int_const_binop (code, arg1, arg2, notrunc);
1273 if (TREE_CODE (arg1) == REAL_CST)
1275 enum machine_mode mode;
1278 REAL_VALUE_TYPE value;
1281 d1 = TREE_REAL_CST (arg1);
1282 d2 = TREE_REAL_CST (arg2);
1284 type = TREE_TYPE (arg1);
1285 mode = TYPE_MODE (type);
1287 /* Don't perform operation if we honor signaling NaNs and
1288 either operand is a NaN. */
1289 if (HONOR_SNANS (mode)
1290 && (REAL_VALUE_ISNAN (d1) || REAL_VALUE_ISNAN (d2)))
1293 /* Don't perform operation if it would raise a division
1294 by zero exception. */
1295 if (code == RDIV_EXPR
1296 && REAL_VALUES_EQUAL (d2, dconst0)
1297 && (flag_trapping_math || ! MODE_HAS_INFINITIES (mode)))
1300 /* If either operand is a NaN, just return it. Otherwise, set up
1301 for floating-point trap; we return an overflow. */
1302 if (REAL_VALUE_ISNAN (d1))
1304 else if (REAL_VALUE_ISNAN (d2))
1307 REAL_ARITHMETIC (value, code, d1, d2);
1309 t = build_real (type, real_value_truncate (mode, value));
1312 = (force_fit_type (t, 0)
1313 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
1314 TREE_CONSTANT_OVERFLOW (t)
1316 | TREE_CONSTANT_OVERFLOW (arg1)
1317 | TREE_CONSTANT_OVERFLOW (arg2);
1320 if (TREE_CODE (arg1) == COMPLEX_CST)
1322 tree type = TREE_TYPE (arg1);
1323 tree r1 = TREE_REALPART (arg1);
1324 tree i1 = TREE_IMAGPART (arg1);
1325 tree r2 = TREE_REALPART (arg2);
1326 tree i2 = TREE_IMAGPART (arg2);
1332 t = build_complex (type,
1333 const_binop (PLUS_EXPR, r1, r2, notrunc),
1334 const_binop (PLUS_EXPR, i1, i2, notrunc));
1338 t = build_complex (type,
1339 const_binop (MINUS_EXPR, r1, r2, notrunc),
1340 const_binop (MINUS_EXPR, i1, i2, notrunc));
1344 t = build_complex (type,
1345 const_binop (MINUS_EXPR,
1346 const_binop (MULT_EXPR,
1348 const_binop (MULT_EXPR,
1351 const_binop (PLUS_EXPR,
1352 const_binop (MULT_EXPR,
1354 const_binop (MULT_EXPR,
1362 = const_binop (PLUS_EXPR,
1363 const_binop (MULT_EXPR, r2, r2, notrunc),
1364 const_binop (MULT_EXPR, i2, i2, notrunc),
1367 t = build_complex (type,
1369 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1370 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1371 const_binop (PLUS_EXPR,
1372 const_binop (MULT_EXPR, r1, r2,
1374 const_binop (MULT_EXPR, i1, i2,
1377 magsquared, notrunc),
1379 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1380 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1381 const_binop (MINUS_EXPR,
1382 const_binop (MULT_EXPR, i1, r2,
1384 const_binop (MULT_EXPR, r1, i2,
1387 magsquared, notrunc));
1399 /* These are the hash table functions for the hash table of INTEGER_CST
1400 nodes of a sizetype. */
1402 /* Return the hash code code X, an INTEGER_CST. */
1405 size_htab_hash (const void *x)
1409 return (TREE_INT_CST_HIGH (t) ^ TREE_INT_CST_LOW (t)
1410 ^ htab_hash_pointer (TREE_TYPE (t))
1411 ^ (TREE_OVERFLOW (t) << 20));
1414 /* Return nonzero if the value represented by *X (an INTEGER_CST tree node)
1415 is the same as that given by *Y, which is the same. */
1418 size_htab_eq (const void *x, const void *y)
1423 return (TREE_INT_CST_HIGH (xt) == TREE_INT_CST_HIGH (yt)
1424 && TREE_INT_CST_LOW (xt) == TREE_INT_CST_LOW (yt)
1425 && TREE_TYPE (xt) == TREE_TYPE (yt)
1426 && TREE_OVERFLOW (xt) == TREE_OVERFLOW (yt));
1429 /* Return an INTEGER_CST with value whose low-order HOST_BITS_PER_WIDE_INT
1430 bits are given by NUMBER and of the sizetype represented by KIND. */
1433 size_int_wide (HOST_WIDE_INT number, enum size_type_kind kind)
1435 return size_int_type_wide (number, sizetype_tab[(int) kind]);
1438 /* Likewise, but the desired type is specified explicitly. */
1440 static GTY (()) tree new_const;
1441 static GTY ((if_marked ("ggc_marked_p"), param_is (union tree_node)))
1445 size_int_type_wide (HOST_WIDE_INT number, tree type)
1451 size_htab = htab_create_ggc (1024, size_htab_hash, size_htab_eq, NULL);
1452 new_const = make_node (INTEGER_CST);
1455 /* Adjust NEW_CONST to be the constant we want. If it's already in the
1456 hash table, we return the value from the hash table. Otherwise, we
1457 place that in the hash table and make a new node for the next time. */
1458 TREE_INT_CST_LOW (new_const) = number;
1459 TREE_INT_CST_HIGH (new_const) = number < 0 ? -1 : 0;
1460 TREE_TYPE (new_const) = type;
1461 TREE_OVERFLOW (new_const) = TREE_CONSTANT_OVERFLOW (new_const)
1462 = force_fit_type (new_const, 0);
1464 slot = htab_find_slot (size_htab, new_const, INSERT);
1470 new_const = make_node (INTEGER_CST);
1474 return (tree) *slot;
1477 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1478 is a tree code. The type of the result is taken from the operands.
1479 Both must be the same type integer type and it must be a size type.
1480 If the operands are constant, so is the result. */
1483 size_binop (enum tree_code code, tree arg0, tree arg1)
1485 tree type = TREE_TYPE (arg0);
1487 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1488 || type != TREE_TYPE (arg1))
1491 /* Handle the special case of two integer constants faster. */
1492 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1494 /* And some specific cases even faster than that. */
1495 if (code == PLUS_EXPR && integer_zerop (arg0))
1497 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1498 && integer_zerop (arg1))
1500 else if (code == MULT_EXPR && integer_onep (arg0))
1503 /* Handle general case of two integer constants. */
1504 return int_const_binop (code, arg0, arg1, 0);
1507 if (arg0 == error_mark_node || arg1 == error_mark_node)
1508 return error_mark_node;
1510 return fold (build (code, type, arg0, arg1));
1513 /* Given two values, either both of sizetype or both of bitsizetype,
1514 compute the difference between the two values. Return the value
1515 in signed type corresponding to the type of the operands. */
1518 size_diffop (tree arg0, tree arg1)
1520 tree type = TREE_TYPE (arg0);
1523 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1524 || type != TREE_TYPE (arg1))
1527 /* If the type is already signed, just do the simple thing. */
1528 if (! TREE_UNSIGNED (type))
1529 return size_binop (MINUS_EXPR, arg0, arg1);
1531 ctype = (type == bitsizetype || type == ubitsizetype
1532 ? sbitsizetype : ssizetype);
1534 /* If either operand is not a constant, do the conversions to the signed
1535 type and subtract. The hardware will do the right thing with any
1536 overflow in the subtraction. */
1537 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
1538 return size_binop (MINUS_EXPR, convert (ctype, arg0),
1539 convert (ctype, arg1));
1541 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
1542 Otherwise, subtract the other way, convert to CTYPE (we know that can't
1543 overflow) and negate (which can't either). Special-case a result
1544 of zero while we're here. */
1545 if (tree_int_cst_equal (arg0, arg1))
1546 return convert (ctype, integer_zero_node);
1547 else if (tree_int_cst_lt (arg1, arg0))
1548 return convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
1550 return size_binop (MINUS_EXPR, convert (ctype, integer_zero_node),
1551 convert (ctype, size_binop (MINUS_EXPR, arg1, arg0)));
1555 /* Given T, a tree representing type conversion of ARG1, a constant,
1556 return a constant tree representing the result of conversion. */
1559 fold_convert (tree t, tree arg1)
1561 tree type = TREE_TYPE (t);
1564 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
1566 if (TREE_CODE (arg1) == INTEGER_CST)
1568 /* If we would build a constant wider than GCC supports,
1569 leave the conversion unfolded. */
1570 if (TYPE_PRECISION (type) > 2 * HOST_BITS_PER_WIDE_INT)
1573 /* If we are trying to make a sizetype for a small integer, use
1574 size_int to pick up cached types to reduce duplicate nodes. */
1575 if (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type)
1576 && !TREE_CONSTANT_OVERFLOW (arg1)
1577 && compare_tree_int (arg1, 10000) < 0)
1578 return size_int_type_wide (TREE_INT_CST_LOW (arg1), type);
1580 /* Given an integer constant, make new constant with new type,
1581 appropriately sign-extended or truncated. */
1582 t = build_int_2 (TREE_INT_CST_LOW (arg1),
1583 TREE_INT_CST_HIGH (arg1));
1584 TREE_TYPE (t) = type;
1585 /* Indicate an overflow if (1) ARG1 already overflowed,
1586 or (2) force_fit_type indicates an overflow.
1587 Tell force_fit_type that an overflow has already occurred
1588 if ARG1 is a too-large unsigned value and T is signed.
1589 But don't indicate an overflow if converting a pointer. */
1591 = ((force_fit_type (t,
1592 (TREE_INT_CST_HIGH (arg1) < 0
1593 && (TREE_UNSIGNED (type)
1594 < TREE_UNSIGNED (TREE_TYPE (arg1)))))
1595 && ! POINTER_TYPE_P (TREE_TYPE (arg1)))
1596 || TREE_OVERFLOW (arg1));
1597 TREE_CONSTANT_OVERFLOW (t)
1598 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1600 else if (TREE_CODE (arg1) == REAL_CST)
1602 /* Don't initialize these, use assignments.
1603 Initialized local aggregates don't work on old compilers. */
1607 tree type1 = TREE_TYPE (arg1);
1610 x = TREE_REAL_CST (arg1);
1611 l = real_value_from_int_cst (type1, TYPE_MIN_VALUE (type));
1613 no_upper_bound = (TYPE_MAX_VALUE (type) == NULL);
1614 if (!no_upper_bound)
1615 u = real_value_from_int_cst (type1, TYPE_MAX_VALUE (type));
1617 /* See if X will be in range after truncation towards 0.
1618 To compensate for truncation, move the bounds away from 0,
1619 but reject if X exactly equals the adjusted bounds. */
1620 REAL_ARITHMETIC (l, MINUS_EXPR, l, dconst1);
1621 if (!no_upper_bound)
1622 REAL_ARITHMETIC (u, PLUS_EXPR, u, dconst1);
1623 /* If X is a NaN, use zero instead and show we have an overflow.
1624 Otherwise, range check. */
1625 if (REAL_VALUE_ISNAN (x))
1626 overflow = 1, x = dconst0;
1627 else if (! (REAL_VALUES_LESS (l, x)
1629 && REAL_VALUES_LESS (x, u)))
1633 HOST_WIDE_INT low, high;
1634 REAL_VALUE_TO_INT (&low, &high, x);
1635 t = build_int_2 (low, high);
1637 TREE_TYPE (t) = type;
1639 = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
1640 TREE_CONSTANT_OVERFLOW (t)
1641 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1643 TREE_TYPE (t) = type;
1645 else if (TREE_CODE (type) == REAL_TYPE)
1647 if (TREE_CODE (arg1) == INTEGER_CST)
1648 return build_real_from_int_cst (type, arg1);
1649 if (TREE_CODE (arg1) == REAL_CST)
1651 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
1653 /* We make a copy of ARG1 so that we don't modify an
1654 existing constant tree. */
1655 t = copy_node (arg1);
1656 TREE_TYPE (t) = type;
1660 t = build_real (type,
1661 real_value_truncate (TYPE_MODE (type),
1662 TREE_REAL_CST (arg1)));
1665 = TREE_OVERFLOW (arg1) | force_fit_type (t, 0);
1666 TREE_CONSTANT_OVERFLOW (t)
1667 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1671 TREE_CONSTANT (t) = 1;
1675 /* Return an expr equal to X but certainly not valid as an lvalue. */
1682 /* These things are certainly not lvalues. */
1683 if (TREE_CODE (x) == NON_LVALUE_EXPR
1684 || TREE_CODE (x) == INTEGER_CST
1685 || TREE_CODE (x) == REAL_CST
1686 || TREE_CODE (x) == STRING_CST
1687 || TREE_CODE (x) == ADDR_EXPR)
1690 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
1691 TREE_CONSTANT (result) = TREE_CONSTANT (x);
1695 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
1696 Zero means allow extended lvalues. */
1698 int pedantic_lvalues;
1700 /* When pedantic, return an expr equal to X but certainly not valid as a
1701 pedantic lvalue. Otherwise, return X. */
1704 pedantic_non_lvalue (tree x)
1706 if (pedantic_lvalues)
1707 return non_lvalue (x);
1712 /* Given a tree comparison code, return the code that is the logical inverse
1713 of the given code. It is not safe to do this for floating-point
1714 comparisons, except for NE_EXPR and EQ_EXPR. */
1716 static enum tree_code
1717 invert_tree_comparison (enum tree_code code)
1738 /* Similar, but return the comparison that results if the operands are
1739 swapped. This is safe for floating-point. */
1741 static enum tree_code
1742 swap_tree_comparison (enum tree_code code)
1763 /* Convert a comparison tree code from an enum tree_code representation
1764 into a compcode bit-based encoding. This function is the inverse of
1765 compcode_to_comparison. */
1768 comparison_to_compcode (enum tree_code code)
1789 /* Convert a compcode bit-based encoding of a comparison operator back
1790 to GCC's enum tree_code representation. This function is the
1791 inverse of comparison_to_compcode. */
1793 static enum tree_code
1794 compcode_to_comparison (int code)
1815 /* Return nonzero if CODE is a tree code that represents a truth value. */
1818 truth_value_p (enum tree_code code)
1820 return (TREE_CODE_CLASS (code) == '<'
1821 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
1822 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
1823 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
1826 /* Return nonzero if two operands (typically of the same tree node)
1827 are necessarily equal. If either argument has side-effects this
1828 function returns zero.
1830 If ONLY_CONST is nonzero, only return nonzero for constants.
1831 This function tests whether the operands are indistinguishable;
1832 it does not test whether they are equal using C's == operation.
1833 The distinction is important for IEEE floating point, because
1834 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
1835 (2) two NaNs may be indistinguishable, but NaN!=NaN.
1837 If ONLY_CONST is zero, a VAR_DECL is considered equal to itself
1838 even though it may hold multiple values during a function.
1839 This is because a GCC tree node guarantees that nothing else is
1840 executed between the evaluation of its "operands" (which may often
1841 be evaluated in arbitrary order). Hence if the operands themselves
1842 don't side-effect, the VAR_DECLs, PARM_DECLs etc... must hold the
1843 same value in each operand/subexpression. Hence a zero value for
1844 ONLY_CONST assumes isochronic (or instantaneous) tree equivalence.
1845 If comparing arbitrary expression trees, such as from different
1846 statements, ONLY_CONST must usually be nonzero. */
1849 operand_equal_p (tree arg0, tree arg1, int only_const)
1853 /* If both types don't have the same signedness, then we can't consider
1854 them equal. We must check this before the STRIP_NOPS calls
1855 because they may change the signedness of the arguments. */
1856 if (TREE_UNSIGNED (TREE_TYPE (arg0)) != TREE_UNSIGNED (TREE_TYPE (arg1)))
1862 if (TREE_CODE (arg0) != TREE_CODE (arg1)
1863 /* This is needed for conversions and for COMPONENT_REF.
1864 Might as well play it safe and always test this. */
1865 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
1866 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
1867 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
1870 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
1871 We don't care about side effects in that case because the SAVE_EXPR
1872 takes care of that for us. In all other cases, two expressions are
1873 equal if they have no side effects. If we have two identical
1874 expressions with side effects that should be treated the same due
1875 to the only side effects being identical SAVE_EXPR's, that will
1876 be detected in the recursive calls below. */
1877 if (arg0 == arg1 && ! only_const
1878 && (TREE_CODE (arg0) == SAVE_EXPR
1879 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
1882 /* Next handle constant cases, those for which we can return 1 even
1883 if ONLY_CONST is set. */
1884 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
1885 switch (TREE_CODE (arg0))
1888 return (! TREE_CONSTANT_OVERFLOW (arg0)
1889 && ! TREE_CONSTANT_OVERFLOW (arg1)
1890 && tree_int_cst_equal (arg0, arg1));
1893 return (! TREE_CONSTANT_OVERFLOW (arg0)
1894 && ! TREE_CONSTANT_OVERFLOW (arg1)
1895 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
1896 TREE_REAL_CST (arg1)));
1902 if (TREE_CONSTANT_OVERFLOW (arg0)
1903 || TREE_CONSTANT_OVERFLOW (arg1))
1906 v1 = TREE_VECTOR_CST_ELTS (arg0);
1907 v2 = TREE_VECTOR_CST_ELTS (arg1);
1910 if (!operand_equal_p (v1, v2, only_const))
1912 v1 = TREE_CHAIN (v1);
1913 v2 = TREE_CHAIN (v2);
1920 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
1922 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
1926 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
1927 && ! memcmp (TREE_STRING_POINTER (arg0),
1928 TREE_STRING_POINTER (arg1),
1929 TREE_STRING_LENGTH (arg0)));
1932 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
1941 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
1944 /* Two conversions are equal only if signedness and modes match. */
1945 if ((TREE_CODE (arg0) == NOP_EXPR || TREE_CODE (arg0) == CONVERT_EXPR)
1946 && (TREE_UNSIGNED (TREE_TYPE (arg0))
1947 != TREE_UNSIGNED (TREE_TYPE (arg1))))
1950 return operand_equal_p (TREE_OPERAND (arg0, 0),
1951 TREE_OPERAND (arg1, 0), 0);
1955 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0)
1956 && operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1),
1960 /* For commutative ops, allow the other order. */
1961 return ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MULT_EXPR
1962 || TREE_CODE (arg0) == MIN_EXPR || TREE_CODE (arg0) == MAX_EXPR
1963 || TREE_CODE (arg0) == BIT_IOR_EXPR
1964 || TREE_CODE (arg0) == BIT_XOR_EXPR
1965 || TREE_CODE (arg0) == BIT_AND_EXPR
1966 || TREE_CODE (arg0) == NE_EXPR || TREE_CODE (arg0) == EQ_EXPR)
1967 && operand_equal_p (TREE_OPERAND (arg0, 0),
1968 TREE_OPERAND (arg1, 1), 0)
1969 && operand_equal_p (TREE_OPERAND (arg0, 1),
1970 TREE_OPERAND (arg1, 0), 0));
1973 /* If either of the pointer (or reference) expressions we are
1974 dereferencing contain a side effect, these cannot be equal. */
1975 if (TREE_SIDE_EFFECTS (arg0)
1976 || TREE_SIDE_EFFECTS (arg1))
1979 switch (TREE_CODE (arg0))
1982 return operand_equal_p (TREE_OPERAND (arg0, 0),
1983 TREE_OPERAND (arg1, 0), 0);
1987 case ARRAY_RANGE_REF:
1988 return (operand_equal_p (TREE_OPERAND (arg0, 0),
1989 TREE_OPERAND (arg1, 0), 0)
1990 && operand_equal_p (TREE_OPERAND (arg0, 1),
1991 TREE_OPERAND (arg1, 1), 0));
1994 return (operand_equal_p (TREE_OPERAND (arg0, 0),
1995 TREE_OPERAND (arg1, 0), 0)
1996 && operand_equal_p (TREE_OPERAND (arg0, 1),
1997 TREE_OPERAND (arg1, 1), 0)
1998 && operand_equal_p (TREE_OPERAND (arg0, 2),
1999 TREE_OPERAND (arg1, 2), 0));
2005 switch (TREE_CODE (arg0))
2008 case TRUTH_NOT_EXPR:
2009 return operand_equal_p (TREE_OPERAND (arg0, 0),
2010 TREE_OPERAND (arg1, 0), 0);
2013 return rtx_equal_p (RTL_EXPR_RTL (arg0), RTL_EXPR_RTL (arg1));
2016 /* If the CALL_EXPRs call different functions, then they
2017 clearly can not be equal. */
2018 if (! operand_equal_p (TREE_OPERAND (arg0, 0),
2019 TREE_OPERAND (arg1, 0), 0))
2022 /* Only consider const functions equivalent. */
2023 fndecl = get_callee_fndecl (arg0);
2024 if (fndecl == NULL_TREE
2025 || ! (flags_from_decl_or_type (fndecl) & ECF_CONST))
2028 /* Now see if all the arguments are the same. operand_equal_p
2029 does not handle TREE_LIST, so we walk the operands here
2030 feeding them to operand_equal_p. */
2031 arg0 = TREE_OPERAND (arg0, 1);
2032 arg1 = TREE_OPERAND (arg1, 1);
2033 while (arg0 && arg1)
2035 if (! operand_equal_p (TREE_VALUE (arg0), TREE_VALUE (arg1), 0))
2038 arg0 = TREE_CHAIN (arg0);
2039 arg1 = TREE_CHAIN (arg1);
2042 /* If we get here and both argument lists are exhausted
2043 then the CALL_EXPRs are equal. */
2044 return ! (arg0 || arg1);
2051 /* Consider __builtin_sqrt equal to sqrt. */
2052 return TREE_CODE (arg0) == FUNCTION_DECL
2053 && DECL_BUILT_IN (arg0) && DECL_BUILT_IN (arg1)
2054 && DECL_BUILT_IN_CLASS (arg0) == DECL_BUILT_IN_CLASS (arg1)
2055 && DECL_FUNCTION_CODE (arg0) == DECL_FUNCTION_CODE (arg1);
2062 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2063 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2065 When in doubt, return 0. */
2068 operand_equal_for_comparison_p (tree arg0, tree arg1, tree other)
2070 int unsignedp1, unsignedpo;
2071 tree primarg0, primarg1, primother;
2072 unsigned int correct_width;
2074 if (operand_equal_p (arg0, arg1, 0))
2077 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
2078 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
2081 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2082 and see if the inner values are the same. This removes any
2083 signedness comparison, which doesn't matter here. */
2084 primarg0 = arg0, primarg1 = arg1;
2085 STRIP_NOPS (primarg0);
2086 STRIP_NOPS (primarg1);
2087 if (operand_equal_p (primarg0, primarg1, 0))
2090 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2091 actual comparison operand, ARG0.
2093 First throw away any conversions to wider types
2094 already present in the operands. */
2096 primarg1 = get_narrower (arg1, &unsignedp1);
2097 primother = get_narrower (other, &unsignedpo);
2099 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
2100 if (unsignedp1 == unsignedpo
2101 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
2102 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
2104 tree type = TREE_TYPE (arg0);
2106 /* Make sure shorter operand is extended the right way
2107 to match the longer operand. */
2108 primarg1 = convert ((*lang_hooks.types.signed_or_unsigned_type)
2109 (unsignedp1, TREE_TYPE (primarg1)), primarg1);
2111 if (operand_equal_p (arg0, convert (type, primarg1), 0))
2118 /* See if ARG is an expression that is either a comparison or is performing
2119 arithmetic on comparisons. The comparisons must only be comparing
2120 two different values, which will be stored in *CVAL1 and *CVAL2; if
2121 they are nonzero it means that some operands have already been found.
2122 No variables may be used anywhere else in the expression except in the
2123 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2124 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2126 If this is true, return 1. Otherwise, return zero. */
2129 twoval_comparison_p (tree arg, tree *cval1, tree *cval2, int *save_p)
2131 enum tree_code code = TREE_CODE (arg);
2132 char class = TREE_CODE_CLASS (code);
2134 /* We can handle some of the 'e' cases here. */
2135 if (class == 'e' && code == TRUTH_NOT_EXPR)
2137 else if (class == 'e'
2138 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
2139 || code == COMPOUND_EXPR))
2142 else if (class == 'e' && code == SAVE_EXPR && SAVE_EXPR_RTL (arg) == 0
2143 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
2145 /* If we've already found a CVAL1 or CVAL2, this expression is
2146 two complex to handle. */
2147 if (*cval1 || *cval2)
2157 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
2160 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
2161 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2162 cval1, cval2, save_p));
2168 if (code == COND_EXPR)
2169 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
2170 cval1, cval2, save_p)
2171 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2172 cval1, cval2, save_p)
2173 && twoval_comparison_p (TREE_OPERAND (arg, 2),
2174 cval1, cval2, save_p));
2178 /* First see if we can handle the first operand, then the second. For
2179 the second operand, we know *CVAL1 can't be zero. It must be that
2180 one side of the comparison is each of the values; test for the
2181 case where this isn't true by failing if the two operands
2184 if (operand_equal_p (TREE_OPERAND (arg, 0),
2185 TREE_OPERAND (arg, 1), 0))
2189 *cval1 = TREE_OPERAND (arg, 0);
2190 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
2192 else if (*cval2 == 0)
2193 *cval2 = TREE_OPERAND (arg, 0);
2194 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
2199 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
2201 else if (*cval2 == 0)
2202 *cval2 = TREE_OPERAND (arg, 1);
2203 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
2215 /* ARG is a tree that is known to contain just arithmetic operations and
2216 comparisons. Evaluate the operations in the tree substituting NEW0 for
2217 any occurrence of OLD0 as an operand of a comparison and likewise for
2221 eval_subst (tree arg, tree old0, tree new0, tree old1, tree new1)
2223 tree type = TREE_TYPE (arg);
2224 enum tree_code code = TREE_CODE (arg);
2225 char class = TREE_CODE_CLASS (code);
2227 /* We can handle some of the 'e' cases here. */
2228 if (class == 'e' && code == TRUTH_NOT_EXPR)
2230 else if (class == 'e'
2231 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2237 return fold (build1 (code, type,
2238 eval_subst (TREE_OPERAND (arg, 0),
2239 old0, new0, old1, new1)));
2242 return fold (build (code, type,
2243 eval_subst (TREE_OPERAND (arg, 0),
2244 old0, new0, old1, new1),
2245 eval_subst (TREE_OPERAND (arg, 1),
2246 old0, new0, old1, new1)));
2252 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
2255 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
2258 return fold (build (code, type,
2259 eval_subst (TREE_OPERAND (arg, 0),
2260 old0, new0, old1, new1),
2261 eval_subst (TREE_OPERAND (arg, 1),
2262 old0, new0, old1, new1),
2263 eval_subst (TREE_OPERAND (arg, 2),
2264 old0, new0, old1, new1)));
2268 /* Fall through - ??? */
2272 tree arg0 = TREE_OPERAND (arg, 0);
2273 tree arg1 = TREE_OPERAND (arg, 1);
2275 /* We need to check both for exact equality and tree equality. The
2276 former will be true if the operand has a side-effect. In that
2277 case, we know the operand occurred exactly once. */
2279 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
2281 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
2284 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
2286 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
2289 return fold (build (code, type, arg0, arg1));
2297 /* Return a tree for the case when the result of an expression is RESULT
2298 converted to TYPE and OMITTED was previously an operand of the expression
2299 but is now not needed (e.g., we folded OMITTED * 0).
2301 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2302 the conversion of RESULT to TYPE. */
2305 omit_one_operand (tree type, tree result, tree omitted)
2307 tree t = convert (type, result);
2309 if (TREE_SIDE_EFFECTS (omitted))
2310 return build (COMPOUND_EXPR, type, omitted, t);
2312 return non_lvalue (t);
2315 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2318 pedantic_omit_one_operand (tree type, tree result, tree omitted)
2320 tree t = convert (type, result);
2322 if (TREE_SIDE_EFFECTS (omitted))
2323 return build (COMPOUND_EXPR, type, omitted, t);
2325 return pedantic_non_lvalue (t);
2328 /* Return a simplified tree node for the truth-negation of ARG. This
2329 never alters ARG itself. We assume that ARG is an operation that
2330 returns a truth value (0 or 1). */
2333 invert_truthvalue (tree arg)
2335 tree type = TREE_TYPE (arg);
2336 enum tree_code code = TREE_CODE (arg);
2338 if (code == ERROR_MARK)
2341 /* If this is a comparison, we can simply invert it, except for
2342 floating-point non-equality comparisons, in which case we just
2343 enclose a TRUTH_NOT_EXPR around what we have. */
2345 if (TREE_CODE_CLASS (code) == '<')
2347 if (FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg, 0)))
2348 && !flag_unsafe_math_optimizations
2351 return build1 (TRUTH_NOT_EXPR, type, arg);
2353 return build (invert_tree_comparison (code), type,
2354 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
2360 return convert (type, build_int_2 (integer_zerop (arg), 0));
2362 case TRUTH_AND_EXPR:
2363 return build (TRUTH_OR_EXPR, type,
2364 invert_truthvalue (TREE_OPERAND (arg, 0)),
2365 invert_truthvalue (TREE_OPERAND (arg, 1)));
2368 return build (TRUTH_AND_EXPR, type,
2369 invert_truthvalue (TREE_OPERAND (arg, 0)),
2370 invert_truthvalue (TREE_OPERAND (arg, 1)));
2372 case TRUTH_XOR_EXPR:
2373 /* Here we can invert either operand. We invert the first operand
2374 unless the second operand is a TRUTH_NOT_EXPR in which case our
2375 result is the XOR of the first operand with the inside of the
2376 negation of the second operand. */
2378 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
2379 return build (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
2380 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
2382 return build (TRUTH_XOR_EXPR, type,
2383 invert_truthvalue (TREE_OPERAND (arg, 0)),
2384 TREE_OPERAND (arg, 1));
2386 case TRUTH_ANDIF_EXPR:
2387 return build (TRUTH_ORIF_EXPR, type,
2388 invert_truthvalue (TREE_OPERAND (arg, 0)),
2389 invert_truthvalue (TREE_OPERAND (arg, 1)));
2391 case TRUTH_ORIF_EXPR:
2392 return build (TRUTH_ANDIF_EXPR, type,
2393 invert_truthvalue (TREE_OPERAND (arg, 0)),
2394 invert_truthvalue (TREE_OPERAND (arg, 1)));
2396 case TRUTH_NOT_EXPR:
2397 return TREE_OPERAND (arg, 0);
2400 return build (COND_EXPR, type, TREE_OPERAND (arg, 0),
2401 invert_truthvalue (TREE_OPERAND (arg, 1)),
2402 invert_truthvalue (TREE_OPERAND (arg, 2)));
2405 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
2406 invert_truthvalue (TREE_OPERAND (arg, 1)));
2408 case WITH_RECORD_EXPR:
2409 return build (WITH_RECORD_EXPR, type,
2410 invert_truthvalue (TREE_OPERAND (arg, 0)),
2411 TREE_OPERAND (arg, 1));
2413 case NON_LVALUE_EXPR:
2414 return invert_truthvalue (TREE_OPERAND (arg, 0));
2419 return build1 (TREE_CODE (arg), type,
2420 invert_truthvalue (TREE_OPERAND (arg, 0)));
2423 if (!integer_onep (TREE_OPERAND (arg, 1)))
2425 return build (EQ_EXPR, type, arg, convert (type, integer_zero_node));
2428 return build1 (TRUTH_NOT_EXPR, type, arg);
2430 case CLEANUP_POINT_EXPR:
2431 return build1 (CLEANUP_POINT_EXPR, type,
2432 invert_truthvalue (TREE_OPERAND (arg, 0)));
2437 if (TREE_CODE (TREE_TYPE (arg)) != BOOLEAN_TYPE)
2439 return build1 (TRUTH_NOT_EXPR, type, arg);
2442 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
2443 operands are another bit-wise operation with a common input. If so,
2444 distribute the bit operations to save an operation and possibly two if
2445 constants are involved. For example, convert
2446 (A | B) & (A | C) into A | (B & C)
2447 Further simplification will occur if B and C are constants.
2449 If this optimization cannot be done, 0 will be returned. */
2452 distribute_bit_expr (enum tree_code code, tree type, tree arg0, tree arg1)
2457 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2458 || TREE_CODE (arg0) == code
2459 || (TREE_CODE (arg0) != BIT_AND_EXPR
2460 && TREE_CODE (arg0) != BIT_IOR_EXPR))
2463 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
2465 common = TREE_OPERAND (arg0, 0);
2466 left = TREE_OPERAND (arg0, 1);
2467 right = TREE_OPERAND (arg1, 1);
2469 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
2471 common = TREE_OPERAND (arg0, 0);
2472 left = TREE_OPERAND (arg0, 1);
2473 right = TREE_OPERAND (arg1, 0);
2475 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
2477 common = TREE_OPERAND (arg0, 1);
2478 left = TREE_OPERAND (arg0, 0);
2479 right = TREE_OPERAND (arg1, 1);
2481 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
2483 common = TREE_OPERAND (arg0, 1);
2484 left = TREE_OPERAND (arg0, 0);
2485 right = TREE_OPERAND (arg1, 0);
2490 return fold (build (TREE_CODE (arg0), type, common,
2491 fold (build (code, type, left, right))));
2494 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
2495 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
2498 make_bit_field_ref (tree inner, tree type, int bitsize, int bitpos,
2501 tree result = build (BIT_FIELD_REF, type, inner,
2502 size_int (bitsize), bitsize_int (bitpos));
2504 TREE_UNSIGNED (result) = unsignedp;
2509 /* Optimize a bit-field compare.
2511 There are two cases: First is a compare against a constant and the
2512 second is a comparison of two items where the fields are at the same
2513 bit position relative to the start of a chunk (byte, halfword, word)
2514 large enough to contain it. In these cases we can avoid the shift
2515 implicit in bitfield extractions.
2517 For constants, we emit a compare of the shifted constant with the
2518 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
2519 compared. For two fields at the same position, we do the ANDs with the
2520 similar mask and compare the result of the ANDs.
2522 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
2523 COMPARE_TYPE is the type of the comparison, and LHS and RHS
2524 are the left and right operands of the comparison, respectively.
2526 If the optimization described above can be done, we return the resulting
2527 tree. Otherwise we return zero. */
2530 optimize_bit_field_compare (enum tree_code code, tree compare_type,
2533 HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
2534 tree type = TREE_TYPE (lhs);
2535 tree signed_type, unsigned_type;
2536 int const_p = TREE_CODE (rhs) == INTEGER_CST;
2537 enum machine_mode lmode, rmode, nmode;
2538 int lunsignedp, runsignedp;
2539 int lvolatilep = 0, rvolatilep = 0;
2540 tree linner, rinner = NULL_TREE;
2544 /* Get all the information about the extractions being done. If the bit size
2545 if the same as the size of the underlying object, we aren't doing an
2546 extraction at all and so can do nothing. We also don't want to
2547 do anything if the inner expression is a PLACEHOLDER_EXPR since we
2548 then will no longer be able to replace it. */
2549 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
2550 &lunsignedp, &lvolatilep);
2551 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
2552 || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
2557 /* If this is not a constant, we can only do something if bit positions,
2558 sizes, and signedness are the same. */
2559 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
2560 &runsignedp, &rvolatilep);
2562 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
2563 || lunsignedp != runsignedp || offset != 0
2564 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
2568 /* See if we can find a mode to refer to this field. We should be able to,
2569 but fail if we can't. */
2570 nmode = get_best_mode (lbitsize, lbitpos,
2571 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
2572 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
2573 TYPE_ALIGN (TREE_TYPE (rinner))),
2574 word_mode, lvolatilep || rvolatilep);
2575 if (nmode == VOIDmode)
2578 /* Set signed and unsigned types of the precision of this mode for the
2580 signed_type = (*lang_hooks.types.type_for_mode) (nmode, 0);
2581 unsigned_type = (*lang_hooks.types.type_for_mode) (nmode, 1);
2583 /* Compute the bit position and size for the new reference and our offset
2584 within it. If the new reference is the same size as the original, we
2585 won't optimize anything, so return zero. */
2586 nbitsize = GET_MODE_BITSIZE (nmode);
2587 nbitpos = lbitpos & ~ (nbitsize - 1);
2589 if (nbitsize == lbitsize)
2592 if (BYTES_BIG_ENDIAN)
2593 lbitpos = nbitsize - lbitsize - lbitpos;
2595 /* Make the mask to be used against the extracted field. */
2596 mask = build_int_2 (~0, ~0);
2597 TREE_TYPE (mask) = unsigned_type;
2598 force_fit_type (mask, 0);
2599 mask = convert (unsigned_type, mask);
2600 mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
2601 mask = const_binop (RSHIFT_EXPR, mask,
2602 size_int (nbitsize - lbitsize - lbitpos), 0);
2605 /* If not comparing with constant, just rework the comparison
2607 return build (code, compare_type,
2608 build (BIT_AND_EXPR, unsigned_type,
2609 make_bit_field_ref (linner, unsigned_type,
2610 nbitsize, nbitpos, 1),
2612 build (BIT_AND_EXPR, unsigned_type,
2613 make_bit_field_ref (rinner, unsigned_type,
2614 nbitsize, nbitpos, 1),
2617 /* Otherwise, we are handling the constant case. See if the constant is too
2618 big for the field. Warn and return a tree of for 0 (false) if so. We do
2619 this not only for its own sake, but to avoid having to test for this
2620 error case below. If we didn't, we might generate wrong code.
2622 For unsigned fields, the constant shifted right by the field length should
2623 be all zero. For signed fields, the high-order bits should agree with
2628 if (! integer_zerop (const_binop (RSHIFT_EXPR,
2629 convert (unsigned_type, rhs),
2630 size_int (lbitsize), 0)))
2632 warning ("comparison is always %d due to width of bit-field",
2634 return convert (compare_type,
2636 ? integer_one_node : integer_zero_node));
2641 tree tem = const_binop (RSHIFT_EXPR, convert (signed_type, rhs),
2642 size_int (lbitsize - 1), 0);
2643 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
2645 warning ("comparison is always %d due to width of bit-field",
2647 return convert (compare_type,
2649 ? integer_one_node : integer_zero_node));
2653 /* Single-bit compares should always be against zero. */
2654 if (lbitsize == 1 && ! integer_zerop (rhs))
2656 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
2657 rhs = convert (type, integer_zero_node);
2660 /* Make a new bitfield reference, shift the constant over the
2661 appropriate number of bits and mask it with the computed mask
2662 (in case this was a signed field). If we changed it, make a new one. */
2663 lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1);
2666 TREE_SIDE_EFFECTS (lhs) = 1;
2667 TREE_THIS_VOLATILE (lhs) = 1;
2670 rhs = fold (const_binop (BIT_AND_EXPR,
2671 const_binop (LSHIFT_EXPR,
2672 convert (unsigned_type, rhs),
2673 size_int (lbitpos), 0),
2676 return build (code, compare_type,
2677 build (BIT_AND_EXPR, unsigned_type, lhs, mask),
2681 /* Subroutine for fold_truthop: decode a field reference.
2683 If EXP is a comparison reference, we return the innermost reference.
2685 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
2686 set to the starting bit number.
2688 If the innermost field can be completely contained in a mode-sized
2689 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
2691 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
2692 otherwise it is not changed.
2694 *PUNSIGNEDP is set to the signedness of the field.
2696 *PMASK is set to the mask used. This is either contained in a
2697 BIT_AND_EXPR or derived from the width of the field.
2699 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
2701 Return 0 if this is not a component reference or is one that we can't
2702 do anything with. */
2705 decode_field_reference (tree exp, HOST_WIDE_INT *pbitsize,
2706 HOST_WIDE_INT *pbitpos, enum machine_mode *pmode,
2707 int *punsignedp, int *pvolatilep,
2708 tree *pmask, tree *pand_mask)
2710 tree outer_type = 0;
2712 tree mask, inner, offset;
2714 unsigned int precision;
2716 /* All the optimizations using this function assume integer fields.
2717 There are problems with FP fields since the type_for_size call
2718 below can fail for, e.g., XFmode. */
2719 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
2722 /* We are interested in the bare arrangement of bits, so strip everything
2723 that doesn't affect the machine mode. However, record the type of the
2724 outermost expression if it may matter below. */
2725 if (TREE_CODE (exp) == NOP_EXPR
2726 || TREE_CODE (exp) == CONVERT_EXPR
2727 || TREE_CODE (exp) == NON_LVALUE_EXPR)
2728 outer_type = TREE_TYPE (exp);
2731 if (TREE_CODE (exp) == BIT_AND_EXPR)
2733 and_mask = TREE_OPERAND (exp, 1);
2734 exp = TREE_OPERAND (exp, 0);
2735 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
2736 if (TREE_CODE (and_mask) != INTEGER_CST)
2740 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
2741 punsignedp, pvolatilep);
2742 if ((inner == exp && and_mask == 0)
2743 || *pbitsize < 0 || offset != 0
2744 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
2747 /* If the number of bits in the reference is the same as the bitsize of
2748 the outer type, then the outer type gives the signedness. Otherwise
2749 (in case of a small bitfield) the signedness is unchanged. */
2750 if (outer_type && *pbitsize == tree_low_cst (TYPE_SIZE (outer_type), 1))
2751 *punsignedp = TREE_UNSIGNED (outer_type);
2753 /* Compute the mask to access the bitfield. */
2754 unsigned_type = (*lang_hooks.types.type_for_size) (*pbitsize, 1);
2755 precision = TYPE_PRECISION (unsigned_type);
2757 mask = build_int_2 (~0, ~0);
2758 TREE_TYPE (mask) = unsigned_type;
2759 force_fit_type (mask, 0);
2760 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
2761 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
2763 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
2765 mask = fold (build (BIT_AND_EXPR, unsigned_type,
2766 convert (unsigned_type, and_mask), mask));
2769 *pand_mask = and_mask;
2773 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
2777 all_ones_mask_p (tree mask, int size)
2779 tree type = TREE_TYPE (mask);
2780 unsigned int precision = TYPE_PRECISION (type);
2783 tmask = build_int_2 (~0, ~0);
2784 TREE_TYPE (tmask) = (*lang_hooks.types.signed_type) (type);
2785 force_fit_type (tmask, 0);
2787 tree_int_cst_equal (mask,
2788 const_binop (RSHIFT_EXPR,
2789 const_binop (LSHIFT_EXPR, tmask,
2790 size_int (precision - size),
2792 size_int (precision - size), 0));
2795 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
2796 represents the sign bit of EXP's type. If EXP represents a sign
2797 or zero extension, also test VAL against the unextended type.
2798 The return value is the (sub)expression whose sign bit is VAL,
2799 or NULL_TREE otherwise. */
2802 sign_bit_p (tree exp, tree val)
2804 unsigned HOST_WIDE_INT mask_lo, lo;
2805 HOST_WIDE_INT mask_hi, hi;
2809 /* Tree EXP must have an integral type. */
2810 t = TREE_TYPE (exp);
2811 if (! INTEGRAL_TYPE_P (t))
2814 /* Tree VAL must be an integer constant. */
2815 if (TREE_CODE (val) != INTEGER_CST
2816 || TREE_CONSTANT_OVERFLOW (val))
2819 width = TYPE_PRECISION (t);
2820 if (width > HOST_BITS_PER_WIDE_INT)
2822 hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1);
2825 mask_hi = ((unsigned HOST_WIDE_INT) -1
2826 >> (2 * HOST_BITS_PER_WIDE_INT - width));
2832 lo = (unsigned HOST_WIDE_INT) 1 << (width - 1);
2835 mask_lo = ((unsigned HOST_WIDE_INT) -1
2836 >> (HOST_BITS_PER_WIDE_INT - width));
2839 /* We mask off those bits beyond TREE_TYPE (exp) so that we can
2840 treat VAL as if it were unsigned. */
2841 if ((TREE_INT_CST_HIGH (val) & mask_hi) == hi
2842 && (TREE_INT_CST_LOW (val) & mask_lo) == lo)
2845 /* Handle extension from a narrower type. */
2846 if (TREE_CODE (exp) == NOP_EXPR
2847 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width)
2848 return sign_bit_p (TREE_OPERAND (exp, 0), val);
2853 /* Subroutine for fold_truthop: determine if an operand is simple enough
2854 to be evaluated unconditionally. */
2857 simple_operand_p (tree exp)
2859 /* Strip any conversions that don't change the machine mode. */
2860 while ((TREE_CODE (exp) == NOP_EXPR
2861 || TREE_CODE (exp) == CONVERT_EXPR)
2862 && (TYPE_MODE (TREE_TYPE (exp))
2863 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)))))
2864 exp = TREE_OPERAND (exp, 0);
2866 return (TREE_CODE_CLASS (TREE_CODE (exp)) == 'c'
2868 && ! TREE_ADDRESSABLE (exp)
2869 && ! TREE_THIS_VOLATILE (exp)
2870 && ! DECL_NONLOCAL (exp)
2871 /* Don't regard global variables as simple. They may be
2872 allocated in ways unknown to the compiler (shared memory,
2873 #pragma weak, etc). */
2874 && ! TREE_PUBLIC (exp)
2875 && ! DECL_EXTERNAL (exp)
2876 /* Loading a static variable is unduly expensive, but global
2877 registers aren't expensive. */
2878 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
2881 /* The following functions are subroutines to fold_range_test and allow it to
2882 try to change a logical combination of comparisons into a range test.
2885 X == 2 || X == 3 || X == 4 || X == 5
2889 (unsigned) (X - 2) <= 3
2891 We describe each set of comparisons as being either inside or outside
2892 a range, using a variable named like IN_P, and then describe the
2893 range with a lower and upper bound. If one of the bounds is omitted,
2894 it represents either the highest or lowest value of the type.
2896 In the comments below, we represent a range by two numbers in brackets
2897 preceded by a "+" to designate being inside that range, or a "-" to
2898 designate being outside that range, so the condition can be inverted by
2899 flipping the prefix. An omitted bound is represented by a "-". For
2900 example, "- [-, 10]" means being outside the range starting at the lowest
2901 possible value and ending at 10, in other words, being greater than 10.
2902 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
2905 We set up things so that the missing bounds are handled in a consistent
2906 manner so neither a missing bound nor "true" and "false" need to be
2907 handled using a special case. */
2909 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
2910 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
2911 and UPPER1_P are nonzero if the respective argument is an upper bound
2912 and zero for a lower. TYPE, if nonzero, is the type of the result; it
2913 must be specified for a comparison. ARG1 will be converted to ARG0's
2914 type if both are specified. */
2917 range_binop (enum tree_code code, tree type, tree arg0, int upper0_p,
2918 tree arg1, int upper1_p)
2924 /* If neither arg represents infinity, do the normal operation.
2925 Else, if not a comparison, return infinity. Else handle the special
2926 comparison rules. Note that most of the cases below won't occur, but
2927 are handled for consistency. */
2929 if (arg0 != 0 && arg1 != 0)
2931 tem = fold (build (code, type != 0 ? type : TREE_TYPE (arg0),
2932 arg0, convert (TREE_TYPE (arg0), arg1)));
2934 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
2937 if (TREE_CODE_CLASS (code) != '<')
2940 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
2941 for neither. In real maths, we cannot assume open ended ranges are
2942 the same. But, this is computer arithmetic, where numbers are finite.
2943 We can therefore make the transformation of any unbounded range with
2944 the value Z, Z being greater than any representable number. This permits
2945 us to treat unbounded ranges as equal. */
2946 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
2947 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
2951 result = sgn0 == sgn1;
2954 result = sgn0 != sgn1;
2957 result = sgn0 < sgn1;
2960 result = sgn0 <= sgn1;
2963 result = sgn0 > sgn1;
2966 result = sgn0 >= sgn1;
2972 return convert (type, result ? integer_one_node : integer_zero_node);
2975 /* Given EXP, a logical expression, set the range it is testing into
2976 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
2977 actually being tested. *PLOW and *PHIGH will be made of the same type
2978 as the returned expression. If EXP is not a comparison, we will most
2979 likely not be returning a useful value and range. */
2982 make_range (tree exp, int *pin_p, tree *plow, tree *phigh)
2984 enum tree_code code;
2985 tree arg0 = NULL_TREE, arg1 = NULL_TREE, type = NULL_TREE;
2986 tree orig_type = NULL_TREE;
2988 tree low, high, n_low, n_high;
2990 /* Start with simply saying "EXP != 0" and then look at the code of EXP
2991 and see if we can refine the range. Some of the cases below may not
2992 happen, but it doesn't seem worth worrying about this. We "continue"
2993 the outer loop when we've changed something; otherwise we "break"
2994 the switch, which will "break" the while. */
2996 in_p = 0, low = high = convert (TREE_TYPE (exp), integer_zero_node);
3000 code = TREE_CODE (exp);
3002 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
3004 if (first_rtl_op (code) > 0)
3005 arg0 = TREE_OPERAND (exp, 0);
3006 if (TREE_CODE_CLASS (code) == '<'
3007 || TREE_CODE_CLASS (code) == '1'
3008 || TREE_CODE_CLASS (code) == '2')
3009 type = TREE_TYPE (arg0);
3010 if (TREE_CODE_CLASS (code) == '2'
3011 || TREE_CODE_CLASS (code) == '<'
3012 || (TREE_CODE_CLASS (code) == 'e'
3013 && TREE_CODE_LENGTH (code) > 1))
3014 arg1 = TREE_OPERAND (exp, 1);
3017 /* Set ORIG_TYPE as soon as TYPE is non-null so that we do not
3018 lose a cast by accident. */
3019 if (type != NULL_TREE && orig_type == NULL_TREE)
3024 case TRUTH_NOT_EXPR:
3025 in_p = ! in_p, exp = arg0;
3028 case EQ_EXPR: case NE_EXPR:
3029 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
3030 /* We can only do something if the range is testing for zero
3031 and if the second operand is an integer constant. Note that
3032 saying something is "in" the range we make is done by
3033 complementing IN_P since it will set in the initial case of
3034 being not equal to zero; "out" is leaving it alone. */
3035 if (low == 0 || high == 0
3036 || ! integer_zerop (low) || ! integer_zerop (high)
3037 || TREE_CODE (arg1) != INTEGER_CST)
3042 case NE_EXPR: /* - [c, c] */
3045 case EQ_EXPR: /* + [c, c] */
3046 in_p = ! in_p, low = high = arg1;
3048 case GT_EXPR: /* - [-, c] */
3049 low = 0, high = arg1;
3051 case GE_EXPR: /* + [c, -] */
3052 in_p = ! in_p, low = arg1, high = 0;
3054 case LT_EXPR: /* - [c, -] */
3055 low = arg1, high = 0;
3057 case LE_EXPR: /* + [-, c] */
3058 in_p = ! in_p, low = 0, high = arg1;
3066 /* If this is an unsigned comparison, we also know that EXP is
3067 greater than or equal to zero. We base the range tests we make
3068 on that fact, so we record it here so we can parse existing
3070 if (TREE_UNSIGNED (type) && (low == 0 || high == 0))
3072 if (! merge_ranges (&n_in_p, &n_low, &n_high, in_p, low, high,
3073 1, convert (type, integer_zero_node),
3077 in_p = n_in_p, low = n_low, high = n_high;
3079 /* If the high bound is missing, but we
3080 have a low bound, reverse the range so
3081 it goes from zero to the low bound minus 1. */
3082 if (high == 0 && low)
3085 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
3086 integer_one_node, 0);
3087 low = convert (type, integer_zero_node);
3093 /* (-x) IN [a,b] -> x in [-b, -a] */
3094 n_low = range_binop (MINUS_EXPR, type,
3095 convert (type, integer_zero_node), 0, high, 1);
3096 n_high = range_binop (MINUS_EXPR, type,
3097 convert (type, integer_zero_node), 0, low, 0);
3098 low = n_low, high = n_high;
3104 exp = build (MINUS_EXPR, type, negate_expr (arg0),
3105 convert (type, integer_one_node));
3108 case PLUS_EXPR: case MINUS_EXPR:
3109 if (TREE_CODE (arg1) != INTEGER_CST)
3112 /* If EXP is signed, any overflow in the computation is undefined,
3113 so we don't worry about it so long as our computations on
3114 the bounds don't overflow. For unsigned, overflow is defined
3115 and this is exactly the right thing. */
3116 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3117 type, low, 0, arg1, 0);
3118 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3119 type, high, 1, arg1, 0);
3120 if ((n_low != 0 && TREE_OVERFLOW (n_low))
3121 || (n_high != 0 && TREE_OVERFLOW (n_high)))
3124 /* Check for an unsigned range which has wrapped around the maximum
3125 value thus making n_high < n_low, and normalize it. */
3126 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
3128 low = range_binop (PLUS_EXPR, type, n_high, 0,
3129 integer_one_node, 0);
3130 high = range_binop (MINUS_EXPR, type, n_low, 0,
3131 integer_one_node, 0);
3133 /* If the range is of the form +/- [ x+1, x ], we won't
3134 be able to normalize it. But then, it represents the
3135 whole range or the empty set, so make it
3137 if (tree_int_cst_equal (n_low, low)
3138 && tree_int_cst_equal (n_high, high))
3144 low = n_low, high = n_high;
3149 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
3150 if (TYPE_PRECISION (type) > TYPE_PRECISION (orig_type))
3153 if (! INTEGRAL_TYPE_P (type)
3154 || (low != 0 && ! int_fits_type_p (low, type))
3155 || (high != 0 && ! int_fits_type_p (high, type)))
3158 n_low = low, n_high = high;
3161 n_low = convert (type, n_low);
3164 n_high = convert (type, n_high);
3166 /* If we're converting from an unsigned to a signed type,
3167 we will be doing the comparison as unsigned. The tests above
3168 have already verified that LOW and HIGH are both positive.
3170 So we have to make sure that the original unsigned value will
3171 be interpreted as positive. */
3172 if (TREE_UNSIGNED (type) && ! TREE_UNSIGNED (TREE_TYPE (exp)))
3174 tree equiv_type = (*lang_hooks.types.type_for_mode)
3175 (TYPE_MODE (type), 1);
3178 /* A range without an upper bound is, naturally, unbounded.
3179 Since convert would have cropped a very large value, use
3180 the max value for the destination type. */
3182 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
3183 : TYPE_MAX_VALUE (type);
3185 if (TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (exp)))
3186 high_positive = fold (build (RSHIFT_EXPR, type,
3187 convert (type, high_positive),
3188 convert (type, integer_one_node)));
3190 /* If the low bound is specified, "and" the range with the
3191 range for which the original unsigned value will be
3195 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3197 1, convert (type, integer_zero_node),
3201 in_p = (n_in_p == in_p);
3205 /* Otherwise, "or" the range with the range of the input
3206 that will be interpreted as negative. */
3207 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3209 1, convert (type, integer_zero_node),
3213 in_p = (in_p != n_in_p);
3218 low = n_low, high = n_high;
3228 /* If EXP is a constant, we can evaluate whether this is true or false. */
3229 if (TREE_CODE (exp) == INTEGER_CST)
3231 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
3233 && integer_onep (range_binop (LE_EXPR, integer_type_node,
3239 *pin_p = in_p, *plow = low, *phigh = high;
3243 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3244 type, TYPE, return an expression to test if EXP is in (or out of, depending
3245 on IN_P) the range. */
3248 build_range_check (tree type, tree exp, int in_p, tree low, tree high)
3250 tree etype = TREE_TYPE (exp);
3254 && (0 != (value = build_range_check (type, exp, 1, low, high))))
3255 return invert_truthvalue (value);
3257 if (low == 0 && high == 0)
3258 return convert (type, integer_one_node);
3261 return fold (build (LE_EXPR, type, exp, high));
3264 return fold (build (GE_EXPR, type, exp, low));
3266 if (operand_equal_p (low, high, 0))
3267 return fold (build (EQ_EXPR, type, exp, low));
3269 if (integer_zerop (low))
3271 if (! TREE_UNSIGNED (etype))
3273 etype = (*lang_hooks.types.unsigned_type) (etype);
3274 high = convert (etype, high);
3275 exp = convert (etype, exp);
3277 return build_range_check (type, exp, 1, 0, high);
3280 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
3281 if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST)
3283 unsigned HOST_WIDE_INT lo;
3287 prec = TYPE_PRECISION (etype);
3288 if (prec <= HOST_BITS_PER_WIDE_INT)
3291 lo = ((unsigned HOST_WIDE_INT) 1 << (prec - 1)) - 1;
3295 hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1;
3296 lo = (unsigned HOST_WIDE_INT) -1;
3299 if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo)
3301 if (TREE_UNSIGNED (etype))
3303 etype = (*lang_hooks.types.signed_type) (etype);
3304 exp = convert (etype, exp);
3306 return fold (build (GT_EXPR, type, exp,
3307 convert (etype, integer_zero_node)));
3311 if (0 != (value = const_binop (MINUS_EXPR, high, low, 0))
3312 && ! TREE_OVERFLOW (value))
3313 return build_range_check (type,
3314 fold (build (MINUS_EXPR, etype, exp, low)),
3315 1, convert (etype, integer_zero_node), value);
3320 /* Given two ranges, see if we can merge them into one. Return 1 if we
3321 can, 0 if we can't. Set the output range into the specified parameters. */
3324 merge_ranges (int *pin_p, tree *plow, tree *phigh, int in0_p, tree low0,
3325 tree high0, int in1_p, tree low1, tree high1)
3333 int lowequal = ((low0 == 0 && low1 == 0)
3334 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3335 low0, 0, low1, 0)));
3336 int highequal = ((high0 == 0 && high1 == 0)
3337 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3338 high0, 1, high1, 1)));
3340 /* Make range 0 be the range that starts first, or ends last if they
3341 start at the same value. Swap them if it isn't. */
3342 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
3345 && integer_onep (range_binop (GT_EXPR, integer_type_node,
3346 high1, 1, high0, 1))))
3348 temp = in0_p, in0_p = in1_p, in1_p = temp;
3349 tem = low0, low0 = low1, low1 = tem;
3350 tem = high0, high0 = high1, high1 = tem;
3353 /* Now flag two cases, whether the ranges are disjoint or whether the
3354 second range is totally subsumed in the first. Note that the tests
3355 below are simplified by the ones above. */
3356 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
3357 high0, 1, low1, 0));
3358 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
3359 high1, 1, high0, 1));
3361 /* We now have four cases, depending on whether we are including or
3362 excluding the two ranges. */
3365 /* If they don't overlap, the result is false. If the second range
3366 is a subset it is the result. Otherwise, the range is from the start
3367 of the second to the end of the first. */
3369 in_p = 0, low = high = 0;
3371 in_p = 1, low = low1, high = high1;
3373 in_p = 1, low = low1, high = high0;
3376 else if (in0_p && ! in1_p)
3378 /* If they don't overlap, the result is the first range. If they are
3379 equal, the result is false. If the second range is a subset of the
3380 first, and the ranges begin at the same place, we go from just after
3381 the end of the first range to the end of the second. If the second
3382 range is not a subset of the first, or if it is a subset and both
3383 ranges end at the same place, the range starts at the start of the
3384 first range and ends just before the second range.
3385 Otherwise, we can't describe this as a single range. */
3387 in_p = 1, low = low0, high = high0;
3388 else if (lowequal && highequal)
3389 in_p = 0, low = high = 0;
3390 else if (subset && lowequal)
3392 in_p = 1, high = high0;
3393 low = range_binop (PLUS_EXPR, NULL_TREE, high1, 0,
3394 integer_one_node, 0);
3396 else if (! subset || highequal)
3398 in_p = 1, low = low0;
3399 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
3400 integer_one_node, 0);
3406 else if (! in0_p && in1_p)
3408 /* If they don't overlap, the result is the second range. If the second
3409 is a subset of the first, the result is false. Otherwise,
3410 the range starts just after the first range and ends at the
3411 end of the second. */
3413 in_p = 1, low = low1, high = high1;
3414 else if (subset || highequal)
3415 in_p = 0, low = high = 0;
3418 in_p = 1, high = high1;
3419 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
3420 integer_one_node, 0);
3426 /* The case where we are excluding both ranges. Here the complex case
3427 is if they don't overlap. In that case, the only time we have a
3428 range is if they are adjacent. If the second is a subset of the
3429 first, the result is the first. Otherwise, the range to exclude
3430 starts at the beginning of the first range and ends at the end of the
3434 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
3435 range_binop (PLUS_EXPR, NULL_TREE,
3437 integer_one_node, 1),
3439 in_p = 0, low = low0, high = high1;
3444 in_p = 0, low = low0, high = high0;
3446 in_p = 0, low = low0, high = high1;
3449 *pin_p = in_p, *plow = low, *phigh = high;
3453 #ifndef RANGE_TEST_NON_SHORT_CIRCUIT
3454 #define RANGE_TEST_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
3457 /* EXP is some logical combination of boolean tests. See if we can
3458 merge it into some range test. Return the new tree if so. */
3461 fold_range_test (tree exp)
3463 int or_op = (TREE_CODE (exp) == TRUTH_ORIF_EXPR
3464 || TREE_CODE (exp) == TRUTH_OR_EXPR);
3465 int in0_p, in1_p, in_p;
3466 tree low0, low1, low, high0, high1, high;
3467 tree lhs = make_range (TREE_OPERAND (exp, 0), &in0_p, &low0, &high0);
3468 tree rhs = make_range (TREE_OPERAND (exp, 1), &in1_p, &low1, &high1);
3471 /* If this is an OR operation, invert both sides; we will invert
3472 again at the end. */
3474 in0_p = ! in0_p, in1_p = ! in1_p;
3476 /* If both expressions are the same, if we can merge the ranges, and we
3477 can build the range test, return it or it inverted. If one of the
3478 ranges is always true or always false, consider it to be the same
3479 expression as the other. */
3480 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
3481 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
3483 && 0 != (tem = (build_range_check (TREE_TYPE (exp),
3485 : rhs != 0 ? rhs : integer_zero_node,
3487 return or_op ? invert_truthvalue (tem) : tem;
3489 /* On machines where the branch cost is expensive, if this is a
3490 short-circuited branch and the underlying object on both sides
3491 is the same, make a non-short-circuit operation. */
3492 else if (RANGE_TEST_NON_SHORT_CIRCUIT
3493 && lhs != 0 && rhs != 0
3494 && (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3495 || TREE_CODE (exp) == TRUTH_ORIF_EXPR)
3496 && operand_equal_p (lhs, rhs, 0))
3498 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
3499 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
3500 which cases we can't do this. */
3501 if (simple_operand_p (lhs))
3502 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3503 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3504 TREE_TYPE (exp), TREE_OPERAND (exp, 0),
3505 TREE_OPERAND (exp, 1));
3507 else if ((*lang_hooks.decls.global_bindings_p) () == 0
3508 && ! CONTAINS_PLACEHOLDER_P (lhs))
3510 tree common = save_expr (lhs);
3512 if (0 != (lhs = build_range_check (TREE_TYPE (exp), common,
3513 or_op ? ! in0_p : in0_p,
3515 && (0 != (rhs = build_range_check (TREE_TYPE (exp), common,
3516 or_op ? ! in1_p : in1_p,
3518 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3519 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3520 TREE_TYPE (exp), lhs, rhs);
3527 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
3528 bit value. Arrange things so the extra bits will be set to zero if and
3529 only if C is signed-extended to its full width. If MASK is nonzero,
3530 it is an INTEGER_CST that should be AND'ed with the extra bits. */
3533 unextend (tree c, int p, int unsignedp, tree mask)
3535 tree type = TREE_TYPE (c);
3536 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
3539 if (p == modesize || unsignedp)
3542 /* We work by getting just the sign bit into the low-order bit, then
3543 into the high-order bit, then sign-extend. We then XOR that value
3545 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
3546 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
3548 /* We must use a signed type in order to get an arithmetic right shift.
3549 However, we must also avoid introducing accidental overflows, so that
3550 a subsequent call to integer_zerop will work. Hence we must
3551 do the type conversion here. At this point, the constant is either
3552 zero or one, and the conversion to a signed type can never overflow.
3553 We could get an overflow if this conversion is done anywhere else. */
3554 if (TREE_UNSIGNED (type))
3555 temp = convert ((*lang_hooks.types.signed_type) (type), temp);
3557 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
3558 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
3560 temp = const_binop (BIT_AND_EXPR, temp, convert (TREE_TYPE (c), mask), 0);
3561 /* If necessary, convert the type back to match the type of C. */
3562 if (TREE_UNSIGNED (type))
3563 temp = convert (type, temp);
3565 return convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
3568 /* Find ways of folding logical expressions of LHS and RHS:
3569 Try to merge two comparisons to the same innermost item.
3570 Look for range tests like "ch >= '0' && ch <= '9'".
3571 Look for combinations of simple terms on machines with expensive branches
3572 and evaluate the RHS unconditionally.
3574 For example, if we have p->a == 2 && p->b == 4 and we can make an
3575 object large enough to span both A and B, we can do this with a comparison
3576 against the object ANDed with the a mask.
3578 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
3579 operations to do this with one comparison.
3581 We check for both normal comparisons and the BIT_AND_EXPRs made this by
3582 function and the one above.
3584 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
3585 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
3587 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
3590 We return the simplified tree or 0 if no optimization is possible. */
3593 fold_truthop (enum tree_code code, tree truth_type, tree lhs, tree rhs)
3595 /* If this is the "or" of two comparisons, we can do something if
3596 the comparisons are NE_EXPR. If this is the "and", we can do something
3597 if the comparisons are EQ_EXPR. I.e.,
3598 (a->b == 2 && a->c == 4) can become (a->new == NEW).
3600 WANTED_CODE is this operation code. For single bit fields, we can
3601 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
3602 comparison for one-bit fields. */
3604 enum tree_code wanted_code;
3605 enum tree_code lcode, rcode;
3606 tree ll_arg, lr_arg, rl_arg, rr_arg;
3607 tree ll_inner, lr_inner, rl_inner, rr_inner;
3608 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
3609 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
3610 HOST_WIDE_INT xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
3611 HOST_WIDE_INT lnbitsize, lnbitpos, rnbitsize, rnbitpos;
3612 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
3613 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
3614 enum machine_mode lnmode, rnmode;
3615 tree ll_mask, lr_mask, rl_mask, rr_mask;
3616 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
3617 tree l_const, r_const;
3618 tree lntype, rntype, result;
3619 int first_bit, end_bit;
3622 /* Start by getting the comparison codes. Fail if anything is volatile.
3623 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
3624 it were surrounded with a NE_EXPR. */
3626 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
3629 lcode = TREE_CODE (lhs);
3630 rcode = TREE_CODE (rhs);
3632 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
3633 lcode = NE_EXPR, lhs = build (NE_EXPR, truth_type, lhs, integer_zero_node);
3635 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
3636 rcode = NE_EXPR, rhs = build (NE_EXPR, truth_type, rhs, integer_zero_node);
3638 if (TREE_CODE_CLASS (lcode) != '<' || TREE_CODE_CLASS (rcode) != '<')
3641 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
3642 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
3644 ll_arg = TREE_OPERAND (lhs, 0);
3645 lr_arg = TREE_OPERAND (lhs, 1);
3646 rl_arg = TREE_OPERAND (rhs, 0);
3647 rr_arg = TREE_OPERAND (rhs, 1);
3649 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
3650 if (simple_operand_p (ll_arg)
3651 && simple_operand_p (lr_arg)
3652 && !FLOAT_TYPE_P (TREE_TYPE (ll_arg)))
3656 if (operand_equal_p (ll_arg, rl_arg, 0)
3657 && operand_equal_p (lr_arg, rr_arg, 0))
3659 int lcompcode, rcompcode;
3661 lcompcode = comparison_to_compcode (lcode);
3662 rcompcode = comparison_to_compcode (rcode);
3663 compcode = (code == TRUTH_AND_EXPR)
3664 ? lcompcode & rcompcode
3665 : lcompcode | rcompcode;
3667 else if (operand_equal_p (ll_arg, rr_arg, 0)
3668 && operand_equal_p (lr_arg, rl_arg, 0))
3670 int lcompcode, rcompcode;
3672 rcode = swap_tree_comparison (rcode);
3673 lcompcode = comparison_to_compcode (lcode);
3674 rcompcode = comparison_to_compcode (rcode);
3675 compcode = (code == TRUTH_AND_EXPR)
3676 ? lcompcode & rcompcode
3677 : lcompcode | rcompcode;
3682 if (compcode == COMPCODE_TRUE)
3683 return convert (truth_type, integer_one_node);
3684 else if (compcode == COMPCODE_FALSE)
3685 return convert (truth_type, integer_zero_node);
3686 else if (compcode != -1)
3687 return build (compcode_to_comparison (compcode),
3688 truth_type, ll_arg, lr_arg);
3691 /* If the RHS can be evaluated unconditionally and its operands are
3692 simple, it wins to evaluate the RHS unconditionally on machines
3693 with expensive branches. In this case, this isn't a comparison
3694 that can be merged. Avoid doing this if the RHS is a floating-point
3695 comparison since those can trap. */
3697 if (BRANCH_COST >= 2
3698 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
3699 && simple_operand_p (rl_arg)
3700 && simple_operand_p (rr_arg))
3702 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
3703 if (code == TRUTH_OR_EXPR
3704 && lcode == NE_EXPR && integer_zerop (lr_arg)
3705 && rcode == NE_EXPR && integer_zerop (rr_arg)
3706 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
3707 return build (NE_EXPR, truth_type,
3708 build (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
3712 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
3713 if (code == TRUTH_AND_EXPR
3714 && lcode == EQ_EXPR && integer_zerop (lr_arg)
3715 && rcode == EQ_EXPR && integer_zerop (rr_arg)
3716 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
3717 return build (EQ_EXPR, truth_type,
3718 build (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
3722 return build (code, truth_type, lhs, rhs);
3725 /* See if the comparisons can be merged. Then get all the parameters for
3728 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
3729 || (rcode != EQ_EXPR && rcode != NE_EXPR))
3733 ll_inner = decode_field_reference (ll_arg,
3734 &ll_bitsize, &ll_bitpos, &ll_mode,
3735 &ll_unsignedp, &volatilep, &ll_mask,
3737 lr_inner = decode_field_reference (lr_arg,
3738 &lr_bitsize, &lr_bitpos, &lr_mode,
3739 &lr_unsignedp, &volatilep, &lr_mask,
3741 rl_inner = decode_field_reference (rl_arg,
3742 &rl_bitsize, &rl_bitpos, &rl_mode,
3743 &rl_unsignedp, &volatilep, &rl_mask,
3745 rr_inner = decode_field_reference (rr_arg,
3746 &rr_bitsize, &rr_bitpos, &rr_mode,
3747 &rr_unsignedp, &volatilep, &rr_mask,
3750 /* It must be true that the inner operation on the lhs of each
3751 comparison must be the same if we are to be able to do anything.
3752 Then see if we have constants. If not, the same must be true for
3754 if (volatilep || ll_inner == 0 || rl_inner == 0
3755 || ! operand_equal_p (ll_inner, rl_inner, 0))
3758 if (TREE_CODE (lr_arg) == INTEGER_CST
3759 && TREE_CODE (rr_arg) == INTEGER_CST)
3760 l_const = lr_arg, r_const = rr_arg;
3761 else if (lr_inner == 0 || rr_inner == 0
3762 || ! operand_equal_p (lr_inner, rr_inner, 0))
3765 l_const = r_const = 0;
3767 /* If either comparison code is not correct for our logical operation,
3768 fail. However, we can convert a one-bit comparison against zero into
3769 the opposite comparison against that bit being set in the field. */
3771 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
3772 if (lcode != wanted_code)
3774 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
3776 /* Make the left operand unsigned, since we are only interested
3777 in the value of one bit. Otherwise we are doing the wrong
3786 /* This is analogous to the code for l_const above. */
3787 if (rcode != wanted_code)
3789 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
3798 /* After this point all optimizations will generate bit-field
3799 references, which we might not want. */
3800 if (! (*lang_hooks.can_use_bit_fields_p) ())
3803 /* See if we can find a mode that contains both fields being compared on
3804 the left. If we can't, fail. Otherwise, update all constants and masks
3805 to be relative to a field of that size. */
3806 first_bit = MIN (ll_bitpos, rl_bitpos);
3807 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
3808 lnmode = get_best_mode (end_bit - first_bit, first_bit,
3809 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
3811 if (lnmode == VOIDmode)
3814 lnbitsize = GET_MODE_BITSIZE (lnmode);
3815 lnbitpos = first_bit & ~ (lnbitsize - 1);
3816 lntype = (*lang_hooks.types.type_for_size) (lnbitsize, 1);
3817 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
3819 if (BYTES_BIG_ENDIAN)
3821 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
3822 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
3825 ll_mask = const_binop (LSHIFT_EXPR, convert (lntype, ll_mask),
3826 size_int (xll_bitpos), 0);
3827 rl_mask = const_binop (LSHIFT_EXPR, convert (lntype, rl_mask),
3828 size_int (xrl_bitpos), 0);
3832 l_const = convert (lntype, l_const);
3833 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
3834 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
3835 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
3836 fold (build1 (BIT_NOT_EXPR,
3840 warning ("comparison is always %d", wanted_code == NE_EXPR);
3842 return convert (truth_type,
3843 wanted_code == NE_EXPR
3844 ? integer_one_node : integer_zero_node);
3849 r_const = convert (lntype, r_const);
3850 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
3851 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
3852 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
3853 fold (build1 (BIT_NOT_EXPR,
3857 warning ("comparison is always %d", wanted_code == NE_EXPR);
3859 return convert (truth_type,
3860 wanted_code == NE_EXPR
3861 ? integer_one_node : integer_zero_node);
3865 /* If the right sides are not constant, do the same for it. Also,
3866 disallow this optimization if a size or signedness mismatch occurs
3867 between the left and right sides. */
3870 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
3871 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
3872 /* Make sure the two fields on the right
3873 correspond to the left without being swapped. */
3874 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
3877 first_bit = MIN (lr_bitpos, rr_bitpos);
3878 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
3879 rnmode = get_best_mode (end_bit - first_bit, first_bit,
3880 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
3882 if (rnmode == VOIDmode)
3885 rnbitsize = GET_MODE_BITSIZE (rnmode);
3886 rnbitpos = first_bit & ~ (rnbitsize - 1);
3887 rntype = (*lang_hooks.types.type_for_size) (rnbitsize, 1);
3888 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
3890 if (BYTES_BIG_ENDIAN)
3892 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
3893 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
3896 lr_mask = const_binop (LSHIFT_EXPR, convert (rntype, lr_mask),
3897 size_int (xlr_bitpos), 0);
3898 rr_mask = const_binop (LSHIFT_EXPR, convert (rntype, rr_mask),
3899 size_int (xrr_bitpos), 0);
3901 /* Make a mask that corresponds to both fields being compared.
3902 Do this for both items being compared. If the operands are the
3903 same size and the bits being compared are in the same position
3904 then we can do this by masking both and comparing the masked
3906 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
3907 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
3908 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
3910 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
3911 ll_unsignedp || rl_unsignedp);
3912 if (! all_ones_mask_p (ll_mask, lnbitsize))
3913 lhs = build (BIT_AND_EXPR, lntype, lhs, ll_mask);
3915 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
3916 lr_unsignedp || rr_unsignedp);
3917 if (! all_ones_mask_p (lr_mask, rnbitsize))
3918 rhs = build (BIT_AND_EXPR, rntype, rhs, lr_mask);
3920 return build (wanted_code, truth_type, lhs, rhs);
3923 /* There is still another way we can do something: If both pairs of
3924 fields being compared are adjacent, we may be able to make a wider
3925 field containing them both.
3927 Note that we still must mask the lhs/rhs expressions. Furthermore,
3928 the mask must be shifted to account for the shift done by
3929 make_bit_field_ref. */
3930 if ((ll_bitsize + ll_bitpos == rl_bitpos
3931 && lr_bitsize + lr_bitpos == rr_bitpos)
3932 || (ll_bitpos == rl_bitpos + rl_bitsize
3933 && lr_bitpos == rr_bitpos + rr_bitsize))
3937 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
3938 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
3939 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
3940 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
3942 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
3943 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
3944 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
3945 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
3947 /* Convert to the smaller type before masking out unwanted bits. */
3949 if (lntype != rntype)
3951 if (lnbitsize > rnbitsize)
3953 lhs = convert (rntype, lhs);
3954 ll_mask = convert (rntype, ll_mask);
3957 else if (lnbitsize < rnbitsize)
3959 rhs = convert (lntype, rhs);
3960 lr_mask = convert (lntype, lr_mask);
3965 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
3966 lhs = build (BIT_AND_EXPR, type, lhs, ll_mask);
3968 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
3969 rhs = build (BIT_AND_EXPR, type, rhs, lr_mask);
3971 return build (wanted_code, truth_type, lhs, rhs);
3977 /* Handle the case of comparisons with constants. If there is something in
3978 common between the masks, those bits of the constants must be the same.
3979 If not, the condition is always false. Test for this to avoid generating
3980 incorrect code below. */
3981 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
3982 if (! integer_zerop (result)
3983 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
3984 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
3986 if (wanted_code == NE_EXPR)
3988 warning ("`or' of unmatched not-equal tests is always 1");
3989 return convert (truth_type, integer_one_node);
3993 warning ("`and' of mutually exclusive equal-tests is always 0");
3994 return convert (truth_type, integer_zero_node);
3998 /* Construct the expression we will return. First get the component
3999 reference we will make. Unless the mask is all ones the width of
4000 that field, perform the mask operation. Then compare with the
4002 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4003 ll_unsignedp || rl_unsignedp);
4005 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4006 if (! all_ones_mask_p (ll_mask, lnbitsize))
4007 result = build (BIT_AND_EXPR, lntype, result, ll_mask);
4009 return build (wanted_code, truth_type, result,
4010 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
4013 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
4017 optimize_minmax_comparison (tree t)
4019 tree type = TREE_TYPE (t);
4020 tree arg0 = TREE_OPERAND (t, 0);
4021 enum tree_code op_code;
4022 tree comp_const = TREE_OPERAND (t, 1);
4024 int consts_equal, consts_lt;
4027 STRIP_SIGN_NOPS (arg0);
4029 op_code = TREE_CODE (arg0);
4030 minmax_const = TREE_OPERAND (arg0, 1);
4031 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
4032 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
4033 inner = TREE_OPERAND (arg0, 0);
4035 /* If something does not permit us to optimize, return the original tree. */
4036 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
4037 || TREE_CODE (comp_const) != INTEGER_CST
4038 || TREE_CONSTANT_OVERFLOW (comp_const)
4039 || TREE_CODE (minmax_const) != INTEGER_CST
4040 || TREE_CONSTANT_OVERFLOW (minmax_const))
4043 /* Now handle all the various comparison codes. We only handle EQ_EXPR
4044 and GT_EXPR, doing the rest with recursive calls using logical
4046 switch (TREE_CODE (t))
4048 case NE_EXPR: case LT_EXPR: case LE_EXPR:
4050 invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t)));
4054 fold (build (TRUTH_ORIF_EXPR, type,
4055 optimize_minmax_comparison
4056 (build (EQ_EXPR, type, arg0, comp_const)),
4057 optimize_minmax_comparison
4058 (build (GT_EXPR, type, arg0, comp_const))));
4061 if (op_code == MAX_EXPR && consts_equal)
4062 /* MAX (X, 0) == 0 -> X <= 0 */
4063 return fold (build (LE_EXPR, type, inner, comp_const));
4065 else if (op_code == MAX_EXPR && consts_lt)
4066 /* MAX (X, 0) == 5 -> X == 5 */
4067 return fold (build (EQ_EXPR, type, inner, comp_const));
4069 else if (op_code == MAX_EXPR)
4070 /* MAX (X, 0) == -1 -> false */
4071 return omit_one_operand (type, integer_zero_node, inner);
4073 else if (consts_equal)
4074 /* MIN (X, 0) == 0 -> X >= 0 */
4075 return fold (build (GE_EXPR, type, inner, comp_const));
4078 /* MIN (X, 0) == 5 -> false */
4079 return omit_one_operand (type, integer_zero_node, inner);
4082 /* MIN (X, 0) == -1 -> X == -1 */
4083 return fold (build (EQ_EXPR, type, inner, comp_const));
4086 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
4087 /* MAX (X, 0) > 0 -> X > 0
4088 MAX (X, 0) > 5 -> X > 5 */
4089 return fold (build (GT_EXPR, type, inner, comp_const));
4091 else if (op_code == MAX_EXPR)
4092 /* MAX (X, 0) > -1 -> true */
4093 return omit_one_operand (type, integer_one_node, inner);
4095 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
4096 /* MIN (X, 0) > 0 -> false
4097 MIN (X, 0) > 5 -> false */
4098 return omit_one_operand (type, integer_zero_node, inner);
4101 /* MIN (X, 0) > -1 -> X > -1 */
4102 return fold (build (GT_EXPR, type, inner, comp_const));
4109 /* T is an integer expression that is being multiplied, divided, or taken a
4110 modulus (CODE says which and what kind of divide or modulus) by a
4111 constant C. See if we can eliminate that operation by folding it with
4112 other operations already in T. WIDE_TYPE, if non-null, is a type that
4113 should be used for the computation if wider than our type.
4115 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
4116 (X * 2) + (Y * 4). We must, however, be assured that either the original
4117 expression would not overflow or that overflow is undefined for the type
4118 in the language in question.
4120 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
4121 the machine has a multiply-accumulate insn or that this is part of an
4122 addressing calculation.
4124 If we return a non-null expression, it is an equivalent form of the
4125 original computation, but need not be in the original type. */
4128 extract_muldiv (tree t, tree c, enum tree_code code, tree wide_type)
4130 /* To avoid exponential search depth, refuse to allow recursion past
4131 three levels. Beyond that (1) it's highly unlikely that we'll find
4132 something interesting and (2) we've probably processed it before
4133 when we built the inner expression. */
4142 ret = extract_muldiv_1 (t, c, code, wide_type);
4149 extract_muldiv_1 (tree t, tree c, enum tree_code code, tree wide_type)
4151 tree type = TREE_TYPE (t);
4152 enum tree_code tcode = TREE_CODE (t);
4153 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
4154 > GET_MODE_SIZE (TYPE_MODE (type)))
4155 ? wide_type : type);
4157 int same_p = tcode == code;
4158 tree op0 = NULL_TREE, op1 = NULL_TREE;
4160 /* Don't deal with constants of zero here; they confuse the code below. */
4161 if (integer_zerop (c))
4164 if (TREE_CODE_CLASS (tcode) == '1')
4165 op0 = TREE_OPERAND (t, 0);
4167 if (TREE_CODE_CLASS (tcode) == '2')
4168 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
4170 /* Note that we need not handle conditional operations here since fold
4171 already handles those cases. So just do arithmetic here. */
4175 /* For a constant, we can always simplify if we are a multiply
4176 or (for divide and modulus) if it is a multiple of our constant. */
4177 if (code == MULT_EXPR
4178 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
4179 return const_binop (code, convert (ctype, t), convert (ctype, c), 0);
4182 case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
4183 /* If op0 is an expression ... */
4184 if ((TREE_CODE_CLASS (TREE_CODE (op0)) == '<'
4185 || TREE_CODE_CLASS (TREE_CODE (op0)) == '1'
4186 || TREE_CODE_CLASS (TREE_CODE (op0)) == '2'
4187 || TREE_CODE_CLASS (TREE_CODE (op0)) == 'e')
4188 /* ... and is unsigned, and its type is smaller than ctype,
4189 then we cannot pass through as widening. */
4190 && ((TREE_UNSIGNED (TREE_TYPE (op0))
4191 && ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
4192 && TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
4193 && (GET_MODE_SIZE (TYPE_MODE (ctype))
4194 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
4195 /* ... or its type is larger than ctype,
4196 then we cannot pass through this truncation. */
4197 || (GET_MODE_SIZE (TYPE_MODE (ctype))
4198 < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0))))
4199 /* ... or signedness changes for division or modulus,
4200 then we cannot pass through this conversion. */
4201 || (code != MULT_EXPR
4202 && (TREE_UNSIGNED (ctype)
4203 != TREE_UNSIGNED (TREE_TYPE (op0))))))
4206 /* Pass the constant down and see if we can make a simplification. If
4207 we can, replace this expression with the inner simplification for
4208 possible later conversion to our or some other type. */
4209 if ((t2 = convert (TREE_TYPE (op0), c)) != 0
4210 && TREE_CODE (t2) == INTEGER_CST
4211 && ! TREE_CONSTANT_OVERFLOW (t2)
4212 && (0 != (t1 = extract_muldiv (op0, t2, code,
4214 ? ctype : NULL_TREE))))
4218 case NEGATE_EXPR: case ABS_EXPR:
4219 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4220 return fold (build1 (tcode, ctype, convert (ctype, t1)));
4223 case MIN_EXPR: case MAX_EXPR:
4224 /* If widening the type changes the signedness, then we can't perform
4225 this optimization as that changes the result. */
4226 if (TREE_UNSIGNED (ctype) != TREE_UNSIGNED (type))
4229 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
4230 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0
4231 && (t2 = extract_muldiv (op1, c, code, wide_type)) != 0)
4233 if (tree_int_cst_sgn (c) < 0)
4234 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
4236 return fold (build (tcode, ctype, convert (ctype, t1),
4237 convert (ctype, t2)));
4241 case WITH_RECORD_EXPR:
4242 if ((t1 = extract_muldiv (TREE_OPERAND (t, 0), c, code, wide_type)) != 0)
4243 return build (WITH_RECORD_EXPR, TREE_TYPE (t1), t1,
4244 TREE_OPERAND (t, 1));
4247 case LSHIFT_EXPR: case RSHIFT_EXPR:
4248 /* If the second operand is constant, this is a multiplication
4249 or floor division, by a power of two, so we can treat it that
4250 way unless the multiplier or divisor overflows. */
4251 if (TREE_CODE (op1) == INTEGER_CST
4252 /* const_binop may not detect overflow correctly,
4253 so check for it explicitly here. */
4254 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
4255 && TREE_INT_CST_HIGH (op1) == 0
4256 && 0 != (t1 = convert (ctype,
4257 const_binop (LSHIFT_EXPR, size_one_node,
4259 && ! TREE_OVERFLOW (t1))
4260 return extract_muldiv (build (tcode == LSHIFT_EXPR
4261 ? MULT_EXPR : FLOOR_DIV_EXPR,
4262 ctype, convert (ctype, op0), t1),
4263 c, code, wide_type);
4266 case PLUS_EXPR: case MINUS_EXPR:
4267 /* See if we can eliminate the operation on both sides. If we can, we
4268 can return a new PLUS or MINUS. If we can't, the only remaining
4269 cases where we can do anything are if the second operand is a
4271 t1 = extract_muldiv (op0, c, code, wide_type);
4272 t2 = extract_muldiv (op1, c, code, wide_type);
4273 if (t1 != 0 && t2 != 0
4274 && (code == MULT_EXPR
4275 /* If not multiplication, we can only do this if both operands
4276 are divisible by c. */
4277 || (multiple_of_p (ctype, op0, c)
4278 && multiple_of_p (ctype, op1, c))))
4279 return fold (build (tcode, ctype, convert (ctype, t1),
4280 convert (ctype, t2)));
4282 /* If this was a subtraction, negate OP1 and set it to be an addition.
4283 This simplifies the logic below. */
4284 if (tcode == MINUS_EXPR)
4285 tcode = PLUS_EXPR, op1 = negate_expr (op1);
4287 if (TREE_CODE (op1) != INTEGER_CST)
4290 /* If either OP1 or C are negative, this optimization is not safe for
4291 some of the division and remainder types while for others we need
4292 to change the code. */
4293 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
4295 if (code == CEIL_DIV_EXPR)
4296 code = FLOOR_DIV_EXPR;
4297 else if (code == FLOOR_DIV_EXPR)
4298 code = CEIL_DIV_EXPR;
4299 else if (code != MULT_EXPR
4300 && code != CEIL_MOD_EXPR && code != FLOOR_MOD_EXPR)
4304 /* If it's a multiply or a division/modulus operation of a multiple
4305 of our constant, do the operation and verify it doesn't overflow. */
4306 if (code == MULT_EXPR
4307 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4309 op1 = const_binop (code, convert (ctype, op1), convert (ctype, c), 0);
4310 if (op1 == 0 || TREE_OVERFLOW (op1))
4316 /* If we have an unsigned type is not a sizetype, we cannot widen
4317 the operation since it will change the result if the original
4318 computation overflowed. */
4319 if (TREE_UNSIGNED (ctype)
4320 && ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
4324 /* If we were able to eliminate our operation from the first side,
4325 apply our operation to the second side and reform the PLUS. */
4326 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
4327 return fold (build (tcode, ctype, convert (ctype, t1), op1));
4329 /* The last case is if we are a multiply. In that case, we can
4330 apply the distributive law to commute the multiply and addition
4331 if the multiplication of the constants doesn't overflow. */
4332 if (code == MULT_EXPR)
4333 return fold (build (tcode, ctype, fold (build (code, ctype,
4334 convert (ctype, op0),
4335 convert (ctype, c))),
4341 /* We have a special case here if we are doing something like
4342 (C * 8) % 4 since we know that's zero. */
4343 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
4344 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
4345 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
4346 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4347 return omit_one_operand (type, integer_zero_node, op0);
4349 /* ... fall through ... */
4351 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
4352 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
4353 /* If we can extract our operation from the LHS, do so and return a
4354 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
4355 do something only if the second operand is a constant. */
4357 && (t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4358 return fold (build (tcode, ctype, convert (ctype, t1),
4359 convert (ctype, op1)));
4360 else if (tcode == MULT_EXPR && code == MULT_EXPR
4361 && (t1 = extract_muldiv (op1, c, code, wide_type)) != 0)
4362 return fold (build (tcode, ctype, convert (ctype, op0),
4363 convert (ctype, t1)));
4364 else if (TREE_CODE (op1) != INTEGER_CST)
4367 /* If these are the same operation types, we can associate them
4368 assuming no overflow. */
4370 && 0 != (t1 = const_binop (MULT_EXPR, convert (ctype, op1),
4371 convert (ctype, c), 0))
4372 && ! TREE_OVERFLOW (t1))
4373 return fold (build (tcode, ctype, convert (ctype, op0), t1));
4375 /* If these operations "cancel" each other, we have the main
4376 optimizations of this pass, which occur when either constant is a
4377 multiple of the other, in which case we replace this with either an
4378 operation or CODE or TCODE.
4380 If we have an unsigned type that is not a sizetype, we cannot do
4381 this since it will change the result if the original computation
4383 if ((! TREE_UNSIGNED (ctype)
4384 || (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
4386 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
4387 || (tcode == MULT_EXPR
4388 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
4389 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR)))
4391 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4392 return fold (build (tcode, ctype, convert (ctype, op0),
4394 const_binop (TRUNC_DIV_EXPR,
4396 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
4397 return fold (build (code, ctype, convert (ctype, op0),
4399 const_binop (TRUNC_DIV_EXPR,
4411 /* If T contains a COMPOUND_EXPR which was inserted merely to evaluate
4412 S, a SAVE_EXPR, return the expression actually being evaluated. Note
4413 that we may sometimes modify the tree. */
4416 strip_compound_expr (tree t, tree s)
4418 enum tree_code code = TREE_CODE (t);
4420 /* See if this is the COMPOUND_EXPR we want to eliminate. */
4421 if (code == COMPOUND_EXPR && TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR
4422 && TREE_OPERAND (TREE_OPERAND (t, 0), 0) == s)
4423 return TREE_OPERAND (t, 1);
4425 /* See if this is a COND_EXPR or a simple arithmetic operator. We
4426 don't bother handling any other types. */
4427 else if (code == COND_EXPR)
4429 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4430 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4431 TREE_OPERAND (t, 2) = strip_compound_expr (TREE_OPERAND (t, 2), s);
4433 else if (TREE_CODE_CLASS (code) == '1')
4434 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4435 else if (TREE_CODE_CLASS (code) == '<'
4436 || TREE_CODE_CLASS (code) == '2')
4438 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4439 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4445 /* Return a node which has the indicated constant VALUE (either 0 or
4446 1), and is of the indicated TYPE. */
4449 constant_boolean_node (int value, tree type)
4451 if (type == integer_type_node)
4452 return value ? integer_one_node : integer_zero_node;
4453 else if (TREE_CODE (type) == BOOLEAN_TYPE)
4454 return (*lang_hooks.truthvalue_conversion) (value ? integer_one_node :
4458 tree t = build_int_2 (value, 0);
4460 TREE_TYPE (t) = type;
4465 /* Utility function for the following routine, to see how complex a nesting of
4466 COND_EXPRs can be. EXPR is the expression and LIMIT is a count beyond which
4467 we don't care (to avoid spending too much time on complex expressions.). */
4470 count_cond (tree expr, int lim)
4474 if (TREE_CODE (expr) != COND_EXPR)
4479 ctrue = count_cond (TREE_OPERAND (expr, 1), lim - 1);
4480 cfalse = count_cond (TREE_OPERAND (expr, 2), lim - 1 - ctrue);
4481 return MIN (lim, 1 + ctrue + cfalse);
4484 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
4485 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
4486 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
4487 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
4488 COND is the first argument to CODE; otherwise (as in the example
4489 given here), it is the second argument. TYPE is the type of the
4490 original expression. */
4493 fold_binary_op_with_conditional_arg (enum tree_code code, tree type,
4494 tree cond, tree arg, int cond_first_p)
4496 tree test, true_value, false_value;
4497 tree lhs = NULL_TREE;
4498 tree rhs = NULL_TREE;
4499 /* In the end, we'll produce a COND_EXPR. Both arms of the
4500 conditional expression will be binary operations. The left-hand
4501 side of the expression to be executed if the condition is true
4502 will be pointed to by TRUE_LHS. Similarly, the right-hand side
4503 of the expression to be executed if the condition is true will be
4504 pointed to by TRUE_RHS. FALSE_LHS and FALSE_RHS are analogous --
4505 but apply to the expression to be executed if the conditional is
4511 /* These are the codes to use for the left-hand side and right-hand
4512 side of the COND_EXPR. Normally, they are the same as CODE. */
4513 enum tree_code lhs_code = code;
4514 enum tree_code rhs_code = code;
4515 /* And these are the types of the expressions. */
4516 tree lhs_type = type;
4517 tree rhs_type = type;
4522 true_rhs = false_rhs = &arg;
4523 true_lhs = &true_value;
4524 false_lhs = &false_value;
4528 true_lhs = false_lhs = &arg;
4529 true_rhs = &true_value;
4530 false_rhs = &false_value;
4533 if (TREE_CODE (cond) == COND_EXPR)
4535 test = TREE_OPERAND (cond, 0);
4536 true_value = TREE_OPERAND (cond, 1);
4537 false_value = TREE_OPERAND (cond, 2);
4538 /* If this operand throws an expression, then it does not make
4539 sense to try to perform a logical or arithmetic operation
4540 involving it. Instead of building `a + throw 3' for example,
4541 we simply build `a, throw 3'. */
4542 if (VOID_TYPE_P (TREE_TYPE (true_value)))
4546 lhs_code = COMPOUND_EXPR;
4547 lhs_type = void_type_node;
4552 if (VOID_TYPE_P (TREE_TYPE (false_value)))
4556 rhs_code = COMPOUND_EXPR;
4557 rhs_type = void_type_node;
4565 tree testtype = TREE_TYPE (cond);
4567 true_value = convert (testtype, integer_one_node);
4568 false_value = convert (testtype, integer_zero_node);
4571 /* If ARG is complex we want to make sure we only evaluate it once. Though
4572 this is only required if it is volatile, it might be more efficient even
4573 if it is not. However, if we succeed in folding one part to a constant,
4574 we do not need to make this SAVE_EXPR. Since we do this optimization
4575 primarily to see if we do end up with constant and this SAVE_EXPR
4576 interferes with later optimizations, suppressing it when we can is
4579 If we are not in a function, we can't make a SAVE_EXPR, so don't try to
4580 do so. Don't try to see if the result is a constant if an arm is a
4581 COND_EXPR since we get exponential behavior in that case. */
4583 if (saved_expr_p (arg))
4585 else if (lhs == 0 && rhs == 0
4586 && !TREE_CONSTANT (arg)
4587 && (*lang_hooks.decls.global_bindings_p) () == 0
4588 && ((TREE_CODE (arg) != VAR_DECL && TREE_CODE (arg) != PARM_DECL)
4589 || TREE_SIDE_EFFECTS (arg)))
4591 if (TREE_CODE (true_value) != COND_EXPR)
4592 lhs = fold (build (lhs_code, lhs_type, *true_lhs, *true_rhs));
4594 if (TREE_CODE (false_value) != COND_EXPR)
4595 rhs = fold (build (rhs_code, rhs_type, *false_lhs, *false_rhs));
4597 if ((lhs == 0 || ! TREE_CONSTANT (lhs))
4598 && (rhs == 0 || !TREE_CONSTANT (rhs)))
4600 arg = save_expr (arg);
4607 lhs = fold (build (lhs_code, lhs_type, *true_lhs, *true_rhs));
4609 rhs = fold (build (rhs_code, rhs_type, *false_lhs, *false_rhs));
4611 test = fold (build (COND_EXPR, type, test, lhs, rhs));
4614 return build (COMPOUND_EXPR, type,
4615 convert (void_type_node, arg),
4616 strip_compound_expr (test, arg));
4618 return convert (type, test);
4622 /* Subroutine of fold() that checks for the addition of +/- 0.0.
4624 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
4625 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
4626 ADDEND is the same as X.
4628 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
4629 and finite. The problematic cases are when X is zero, and its mode
4630 has signed zeros. In the case of rounding towards -infinity,
4631 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
4632 modes, X + 0 is not the same as X because -0 + 0 is 0. */
4635 fold_real_zero_addition_p (tree type, tree addend, int negate)
4637 if (!real_zerop (addend))
4640 /* Don't allow the fold with -fsignaling-nans. */
4641 if (HONOR_SNANS (TYPE_MODE (type)))
4644 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
4645 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
4648 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
4649 if (TREE_CODE (addend) == REAL_CST
4650 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
4653 /* The mode has signed zeros, and we have to honor their sign.
4654 In this situation, there is only one case we can return true for.
4655 X - 0 is the same as X unless rounding towards -infinity is
4657 return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
4660 /* Subroutine of fold() that checks comparisons of built-in math
4661 functions against real constants.
4663 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
4664 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
4665 is the type of the result and ARG0 and ARG1 are the operands of the
4666 comparison. ARG1 must be a TREE_REAL_CST.
4668 The function returns the constant folded tree if a simplification
4669 can be made, and NULL_TREE otherwise. */
4672 fold_mathfn_compare (enum built_in_function fcode, enum tree_code code,
4673 tree type, tree arg0, tree arg1)
4677 if (fcode == BUILT_IN_SQRT
4678 || fcode == BUILT_IN_SQRTF
4679 || fcode == BUILT_IN_SQRTL)
4681 tree arg = TREE_VALUE (TREE_OPERAND (arg0, 1));
4682 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg0));
4684 c = TREE_REAL_CST (arg1);
4685 if (REAL_VALUE_NEGATIVE (c))
4687 /* sqrt(x) < y is always false, if y is negative. */
4688 if (code == EQ_EXPR || code == LT_EXPR || code == LE_EXPR)
4689 return omit_one_operand (type,
4690 convert (type, integer_zero_node),
4693 /* sqrt(x) > y is always true, if y is negative and we
4694 don't care about NaNs, i.e. negative values of x. */
4695 if (code == NE_EXPR || !HONOR_NANS (mode))
4696 return omit_one_operand (type,
4697 convert (type, integer_one_node),
4700 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
4701 return fold (build (GE_EXPR, type, arg,
4702 build_real (TREE_TYPE (arg), dconst0)));
4704 else if (code == GT_EXPR || code == GE_EXPR)
4708 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
4709 real_convert (&c2, mode, &c2);
4711 if (REAL_VALUE_ISINF (c2))
4713 /* sqrt(x) > y is x == +Inf, when y is very large. */
4714 if (HONOR_INFINITIES (mode))
4715 return fold (build (EQ_EXPR, type, arg,
4716 build_real (TREE_TYPE (arg), c2)));
4718 /* sqrt(x) > y is always false, when y is very large
4719 and we don't care about infinities. */
4720 return omit_one_operand (type,
4721 convert (type, integer_zero_node),
4725 /* sqrt(x) > c is the same as x > c*c. */
4726 return fold (build (code, type, arg,
4727 build_real (TREE_TYPE (arg), c2)));
4729 else if (code == LT_EXPR || code == LE_EXPR)
4733 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
4734 real_convert (&c2, mode, &c2);
4736 if (REAL_VALUE_ISINF (c2))
4738 /* sqrt(x) < y is always true, when y is a very large
4739 value and we don't care about NaNs or Infinities. */
4740 if (! HONOR_NANS (mode) && ! HONOR_INFINITIES (mode))
4741 return omit_one_operand (type,
4742 convert (type, integer_one_node),
4745 /* sqrt(x) < y is x != +Inf when y is very large and we
4746 don't care about NaNs. */
4747 if (! HONOR_NANS (mode))
4748 return fold (build (NE_EXPR, type, arg,
4749 build_real (TREE_TYPE (arg), c2)));
4751 /* sqrt(x) < y is x >= 0 when y is very large and we
4752 don't care about Infinities. */
4753 if (! HONOR_INFINITIES (mode))
4754 return fold (build (GE_EXPR, type, arg,
4755 build_real (TREE_TYPE (arg), dconst0)));
4757 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
4758 if ((*lang_hooks.decls.global_bindings_p) () != 0
4759 || CONTAINS_PLACEHOLDER_P (arg))
4762 arg = save_expr (arg);
4763 return fold (build (TRUTH_ANDIF_EXPR, type,
4764 fold (build (GE_EXPR, type, arg,
4765 build_real (TREE_TYPE (arg),
4767 fold (build (NE_EXPR, type, arg,
4768 build_real (TREE_TYPE (arg),
4772 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
4773 if (! HONOR_NANS (mode))
4774 return fold (build (code, type, arg,
4775 build_real (TREE_TYPE (arg), c2)));
4777 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
4778 if ((*lang_hooks.decls.global_bindings_p) () == 0
4779 && ! CONTAINS_PLACEHOLDER_P (arg))
4781 arg = save_expr (arg);
4782 return fold (build (TRUTH_ANDIF_EXPR, type,
4783 fold (build (GE_EXPR, type, arg,
4784 build_real (TREE_TYPE (arg),
4786 fold (build (code, type, arg,
4787 build_real (TREE_TYPE (arg),
4796 /* Subroutine of fold() that optimizes comparisons against Infinities,
4797 either +Inf or -Inf.
4799 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
4800 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
4801 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
4803 The function returns the constant folded tree if a simplification
4804 can be made, and NULL_TREE otherwise. */
4807 fold_inf_compare (enum tree_code code, tree type, tree arg0, tree arg1)
4809 enum machine_mode mode;
4810 REAL_VALUE_TYPE max;
4814 mode = TYPE_MODE (TREE_TYPE (arg0));
4816 /* For negative infinity swap the sense of the comparison. */
4817 neg = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1));
4819 code = swap_tree_comparison (code);
4824 /* x > +Inf is always false, if with ignore sNANs. */
4825 if (HONOR_SNANS (mode))
4827 return omit_one_operand (type,
4828 convert (type, integer_zero_node),
4832 /* x <= +Inf is always true, if we don't case about NaNs. */
4833 if (! HONOR_NANS (mode))
4834 return omit_one_operand (type,
4835 convert (type, integer_one_node),
4838 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
4839 if ((*lang_hooks.decls.global_bindings_p) () == 0
4840 && ! CONTAINS_PLACEHOLDER_P (arg0))
4842 arg0 = save_expr (arg0);
4843 return fold (build (EQ_EXPR, type, arg0, arg0));
4849 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
4850 real_maxval (&max, neg, mode);
4851 return fold (build (neg ? LT_EXPR : GT_EXPR, type,
4852 arg0, build_real (TREE_TYPE (arg0), max)));
4855 /* x < +Inf is always equal to x <= DBL_MAX. */
4856 real_maxval (&max, neg, mode);
4857 return fold (build (neg ? GE_EXPR : LE_EXPR, type,
4858 arg0, build_real (TREE_TYPE (arg0), max)));
4861 /* x != +Inf is always equal to !(x > DBL_MAX). */
4862 real_maxval (&max, neg, mode);
4863 if (! HONOR_NANS (mode))
4864 return fold (build (neg ? GE_EXPR : LE_EXPR, type,
4865 arg0, build_real (TREE_TYPE (arg0), max)));
4866 temp = fold (build (neg ? LT_EXPR : GT_EXPR, type,
4867 arg0, build_real (TREE_TYPE (arg0), max)));
4868 return fold (build1 (TRUTH_NOT_EXPR, type, temp));
4877 /* If CODE with arguments ARG0 and ARG1 represents a single bit
4878 equality/inequality test, then return a simplified form of
4879 the test using shifts and logical operations. Otherwise return
4880 NULL. TYPE is the desired result type. */
4883 fold_single_bit_test (enum tree_code code, tree arg0, tree arg1,
4886 /* If this is a TRUTH_NOT_EXPR, it may have a single bit test inside
4888 if (code == TRUTH_NOT_EXPR)
4890 code = TREE_CODE (arg0);
4891 if (code != NE_EXPR && code != EQ_EXPR)
4894 /* Extract the arguments of the EQ/NE. */
4895 arg1 = TREE_OPERAND (arg0, 1);
4896 arg0 = TREE_OPERAND (arg0, 0);
4898 /* This requires us to invert the code. */
4899 code = (code == EQ_EXPR ? NE_EXPR : EQ_EXPR);
4902 /* If this is testing a single bit, we can optimize the test. */
4903 if ((code == NE_EXPR || code == EQ_EXPR)
4904 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
4905 && integer_pow2p (TREE_OPERAND (arg0, 1)))
4907 tree inner = TREE_OPERAND (arg0, 0);
4908 tree type = TREE_TYPE (arg0);
4909 int bitnum = tree_log2 (TREE_OPERAND (arg0, 1));
4910 enum machine_mode operand_mode = TYPE_MODE (type);
4912 tree signed_type, unsigned_type;
4915 /* If we have (A & C) != 0 where C is the sign bit of A, convert
4916 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
4917 arg00 = sign_bit_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
4918 if (arg00 != NULL_TREE)
4920 tree stype = (*lang_hooks.types.signed_type) (TREE_TYPE (arg00));
4921 return fold (build (code == EQ_EXPR ? GE_EXPR : LT_EXPR, result_type,
4922 convert (stype, arg00),
4923 convert (stype, integer_zero_node)));
4926 /* At this point, we know that arg0 is not testing the sign bit. */
4927 if (TYPE_PRECISION (type) - 1 == bitnum)
4930 /* Otherwise we have (A & C) != 0 where C is a single bit,
4931 convert that into ((A >> C2) & 1). Where C2 = log2(C).
4932 Similarly for (A & C) == 0. */
4934 /* If INNER is a right shift of a constant and it plus BITNUM does
4935 not overflow, adjust BITNUM and INNER. */
4936 if (TREE_CODE (inner) == RSHIFT_EXPR
4937 && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST
4938 && TREE_INT_CST_HIGH (TREE_OPERAND (inner, 1)) == 0
4939 && bitnum < TYPE_PRECISION (type)
4940 && 0 > compare_tree_int (TREE_OPERAND (inner, 1),
4941 bitnum - TYPE_PRECISION (type)))
4943 bitnum += TREE_INT_CST_LOW (TREE_OPERAND (inner, 1));
4944 inner = TREE_OPERAND (inner, 0);
4947 /* If we are going to be able to omit the AND below, we must do our
4948 operations as unsigned. If we must use the AND, we have a choice.
4949 Normally unsigned is faster, but for some machines signed is. */
4950 #ifdef LOAD_EXTEND_OP
4951 ops_unsigned = (LOAD_EXTEND_OP (operand_mode) == SIGN_EXTEND ? 0 : 1);
4956 signed_type = (*lang_hooks.types.type_for_mode) (operand_mode, 0);
4957 unsigned_type = (*lang_hooks.types.type_for_mode) (operand_mode, 1);
4960 inner = build (RSHIFT_EXPR, ops_unsigned ? unsigned_type : signed_type,
4961 inner, size_int (bitnum));
4963 if (code == EQ_EXPR)
4964 inner = build (BIT_XOR_EXPR, ops_unsigned ? unsigned_type : signed_type,
4965 inner, integer_one_node);
4967 /* Put the AND last so it can combine with more things. */
4968 inner = build (BIT_AND_EXPR, ops_unsigned ? unsigned_type : signed_type,
4969 inner, integer_one_node);
4971 /* Make sure to return the proper type. */
4972 if (TREE_TYPE (inner) != result_type)
4973 inner = convert (result_type, inner);
4980 /* Test whether it is preferable two swap two operands, ARG0 and
4981 ARG1, for example because ARG0 is an integer constant and ARG1
4985 tree_swap_operands_p (tree arg0, tree arg1)
4987 STRIP_SIGN_NOPS (arg0);
4988 STRIP_SIGN_NOPS (arg1);
4990 if (TREE_CODE (arg1) == INTEGER_CST)
4992 if (TREE_CODE (arg0) == INTEGER_CST)
4995 if (TREE_CODE (arg1) == REAL_CST)
4997 if (TREE_CODE (arg0) == REAL_CST)
5000 if (TREE_CODE (arg1) == COMPLEX_CST)
5002 if (TREE_CODE (arg0) == COMPLEX_CST)
5005 if (TREE_CONSTANT (arg1))
5007 if (TREE_CONSTANT (arg0))
5013 /* Perform constant folding and related simplification of EXPR.
5014 The related simplifications include x*1 => x, x*0 => 0, etc.,
5015 and application of the associative law.
5016 NOP_EXPR conversions may be removed freely (as long as we
5017 are careful not to change the C type of the overall expression)
5018 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
5019 but we can constant-fold them if they have constant operands. */
5021 #ifdef ENABLE_FOLD_CHECKING
5022 # define fold(x) fold_1 (x)
5023 static tree fold_1 (tree);
5029 tree t = expr, orig_t;
5030 tree t1 = NULL_TREE;
5032 tree type = TREE_TYPE (expr);
5033 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
5034 enum tree_code code = TREE_CODE (t);
5035 int kind = TREE_CODE_CLASS (code);
5037 /* WINS will be nonzero when the switch is done
5038 if all operands are constant. */
5041 /* Don't try to process an RTL_EXPR since its operands aren't trees.
5042 Likewise for a SAVE_EXPR that's already been evaluated. */
5043 if (code == RTL_EXPR || (code == SAVE_EXPR && SAVE_EXPR_RTL (t) != 0))
5046 /* Return right away if a constant. */
5050 #ifdef MAX_INTEGER_COMPUTATION_MODE
5051 check_max_integer_computation_mode (expr);
5055 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
5059 /* Special case for conversion ops that can have fixed point args. */
5060 arg0 = TREE_OPERAND (t, 0);
5062 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
5064 STRIP_SIGN_NOPS (arg0);
5066 if (arg0 != 0 && TREE_CODE (arg0) == COMPLEX_CST)
5067 subop = TREE_REALPART (arg0);
5071 if (subop != 0 && TREE_CODE (subop) != INTEGER_CST
5072 && TREE_CODE (subop) != REAL_CST)
5073 /* Note that TREE_CONSTANT isn't enough:
5074 static var addresses are constant but we can't
5075 do arithmetic on them. */
5078 else if (IS_EXPR_CODE_CLASS (kind))
5080 int len = first_rtl_op (code);
5082 for (i = 0; i < len; i++)
5084 tree op = TREE_OPERAND (t, i);
5088 continue; /* Valid for CALL_EXPR, at least. */
5090 if (kind == '<' || code == RSHIFT_EXPR)
5092 /* Signedness matters here. Perhaps we can refine this
5094 STRIP_SIGN_NOPS (op);
5097 /* Strip any conversions that don't change the mode. */
5100 if (TREE_CODE (op) == COMPLEX_CST)
5101 subop = TREE_REALPART (op);
5105 if (TREE_CODE (subop) != INTEGER_CST
5106 && TREE_CODE (subop) != REAL_CST)
5107 /* Note that TREE_CONSTANT isn't enough:
5108 static var addresses are constant but we can't
5109 do arithmetic on them. */
5119 /* If this is a commutative operation, and ARG0 is a constant, move it
5120 to ARG1 to reduce the number of tests below. */
5121 if ((code == PLUS_EXPR || code == MULT_EXPR || code == MIN_EXPR
5122 || code == MAX_EXPR || code == BIT_IOR_EXPR || code == BIT_XOR_EXPR
5123 || code == BIT_AND_EXPR)
5124 && tree_swap_operands_p (arg0, arg1))
5125 return fold (build (code, type, arg1, arg0));
5127 /* Now WINS is set as described above,
5128 ARG0 is the first operand of EXPR,
5129 and ARG1 is the second operand (if it has more than one operand).
5131 First check for cases where an arithmetic operation is applied to a
5132 compound, conditional, or comparison operation. Push the arithmetic
5133 operation inside the compound or conditional to see if any folding
5134 can then be done. Convert comparison to conditional for this purpose.
5135 The also optimizes non-constant cases that used to be done in
5138 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
5139 one of the operands is a comparison and the other is a comparison, a
5140 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
5141 code below would make the expression more complex. Change it to a
5142 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
5143 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
5145 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
5146 || code == EQ_EXPR || code == NE_EXPR)
5147 && ((truth_value_p (TREE_CODE (arg0))
5148 && (truth_value_p (TREE_CODE (arg1))
5149 || (TREE_CODE (arg1) == BIT_AND_EXPR
5150 && integer_onep (TREE_OPERAND (arg1, 1)))))
5151 || (truth_value_p (TREE_CODE (arg1))
5152 && (truth_value_p (TREE_CODE (arg0))
5153 || (TREE_CODE (arg0) == BIT_AND_EXPR
5154 && integer_onep (TREE_OPERAND (arg0, 1)))))))
5156 t = fold (build (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
5157 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
5161 if (code == EQ_EXPR)
5162 t = invert_truthvalue (t);
5167 if (TREE_CODE_CLASS (code) == '1')
5169 if (TREE_CODE (arg0) == COMPOUND_EXPR)
5170 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5171 fold (build1 (code, type, TREE_OPERAND (arg0, 1))));
5172 else if (TREE_CODE (arg0) == COND_EXPR)
5174 tree arg01 = TREE_OPERAND (arg0, 1);
5175 tree arg02 = TREE_OPERAND (arg0, 2);
5176 if (! VOID_TYPE_P (TREE_TYPE (arg01)))
5177 arg01 = fold (build1 (code, type, arg01));
5178 if (! VOID_TYPE_P (TREE_TYPE (arg02)))
5179 arg02 = fold (build1 (code, type, arg02));
5180 t = fold (build (COND_EXPR, type, TREE_OPERAND (arg0, 0),
5183 /* If this was a conversion, and all we did was to move into
5184 inside the COND_EXPR, bring it back out. But leave it if
5185 it is a conversion from integer to integer and the
5186 result precision is no wider than a word since such a
5187 conversion is cheap and may be optimized away by combine,
5188 while it couldn't if it were outside the COND_EXPR. Then return
5189 so we don't get into an infinite recursion loop taking the
5190 conversion out and then back in. */
5192 if ((code == NOP_EXPR || code == CONVERT_EXPR
5193 || code == NON_LVALUE_EXPR)
5194 && TREE_CODE (t) == COND_EXPR
5195 && TREE_CODE (TREE_OPERAND (t, 1)) == code
5196 && TREE_CODE (TREE_OPERAND (t, 2)) == code
5197 && ! VOID_TYPE_P (TREE_OPERAND (t, 1))
5198 && ! VOID_TYPE_P (TREE_OPERAND (t, 2))
5199 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))
5200 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 2), 0)))
5201 && ! (INTEGRAL_TYPE_P (TREE_TYPE (t))
5203 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))))
5204 && TYPE_PRECISION (TREE_TYPE (t)) <= BITS_PER_WORD))
5205 t = build1 (code, type,
5207 TREE_TYPE (TREE_OPERAND
5208 (TREE_OPERAND (t, 1), 0)),
5209 TREE_OPERAND (t, 0),
5210 TREE_OPERAND (TREE_OPERAND (t, 1), 0),
5211 TREE_OPERAND (TREE_OPERAND (t, 2), 0)));
5214 else if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<')
5215 return fold (build (COND_EXPR, type, arg0,
5216 fold (build1 (code, type, integer_one_node)),
5217 fold (build1 (code, type, integer_zero_node))));
5219 else if (TREE_CODE_CLASS (code) == '<'
5220 && TREE_CODE (arg0) == COMPOUND_EXPR)
5221 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5222 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
5223 else if (TREE_CODE_CLASS (code) == '<'
5224 && TREE_CODE (arg1) == COMPOUND_EXPR)
5225 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
5226 fold (build (code, type, arg0, TREE_OPERAND (arg1, 1))));
5227 else if (TREE_CODE_CLASS (code) == '2'
5228 || TREE_CODE_CLASS (code) == '<')
5230 if (TREE_CODE (arg1) == COMPOUND_EXPR
5231 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg1, 0))
5232 && ! TREE_SIDE_EFFECTS (arg0))
5233 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
5234 fold (build (code, type,
5235 arg0, TREE_OPERAND (arg1, 1))));
5236 else if ((TREE_CODE (arg1) == COND_EXPR
5237 || (TREE_CODE_CLASS (TREE_CODE (arg1)) == '<'
5238 && TREE_CODE_CLASS (code) != '<'))
5239 && (TREE_CODE (arg0) != COND_EXPR
5240 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
5241 && (! TREE_SIDE_EFFECTS (arg0)
5242 || ((*lang_hooks.decls.global_bindings_p) () == 0
5243 && ! CONTAINS_PLACEHOLDER_P (arg0))))
5245 fold_binary_op_with_conditional_arg (code, type, arg1, arg0,
5246 /*cond_first_p=*/0);
5247 else if (TREE_CODE (arg0) == COMPOUND_EXPR)
5248 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5249 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
5250 else if ((TREE_CODE (arg0) == COND_EXPR
5251 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
5252 && TREE_CODE_CLASS (code) != '<'))
5253 && (TREE_CODE (arg1) != COND_EXPR
5254 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
5255 && (! TREE_SIDE_EFFECTS (arg1)
5256 || ((*lang_hooks.decls.global_bindings_p) () == 0
5257 && ! CONTAINS_PLACEHOLDER_P (arg1))))
5259 fold_binary_op_with_conditional_arg (code, type, arg0, arg1,
5260 /*cond_first_p=*/1);
5274 return fold (DECL_INITIAL (t));
5279 case FIX_TRUNC_EXPR:
5280 /* Other kinds of FIX are not handled properly by fold_convert. */
5282 if (TREE_TYPE (TREE_OPERAND (t, 0)) == TREE_TYPE (t))
5283 return TREE_OPERAND (t, 0);
5285 /* Handle cases of two conversions in a row. */
5286 if (TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
5287 || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR)
5289 tree inside_type = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5290 tree inter_type = TREE_TYPE (TREE_OPERAND (t, 0));
5291 tree final_type = TREE_TYPE (t);
5292 int inside_int = INTEGRAL_TYPE_P (inside_type);
5293 int inside_ptr = POINTER_TYPE_P (inside_type);
5294 int inside_float = FLOAT_TYPE_P (inside_type);
5295 unsigned int inside_prec = TYPE_PRECISION (inside_type);
5296 int inside_unsignedp = TREE_UNSIGNED (inside_type);
5297 int inter_int = INTEGRAL_TYPE_P (inter_type);
5298 int inter_ptr = POINTER_TYPE_P (inter_type);
5299 int inter_float = FLOAT_TYPE_P (inter_type);
5300 unsigned int inter_prec = TYPE_PRECISION (inter_type);
5301 int inter_unsignedp = TREE_UNSIGNED (inter_type);
5302 int final_int = INTEGRAL_TYPE_P (final_type);
5303 int final_ptr = POINTER_TYPE_P (final_type);
5304 int final_float = FLOAT_TYPE_P (final_type);
5305 unsigned int final_prec = TYPE_PRECISION (final_type);
5306 int final_unsignedp = TREE_UNSIGNED (final_type);
5308 /* In addition to the cases of two conversions in a row
5309 handled below, if we are converting something to its own
5310 type via an object of identical or wider precision, neither
5311 conversion is needed. */
5312 if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (final_type)
5313 && ((inter_int && final_int) || (inter_float && final_float))
5314 && inter_prec >= final_prec)
5315 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5317 /* Likewise, if the intermediate and final types are either both
5318 float or both integer, we don't need the middle conversion if
5319 it is wider than the final type and doesn't change the signedness
5320 (for integers). Avoid this if the final type is a pointer
5321 since then we sometimes need the inner conversion. Likewise if
5322 the outer has a precision not equal to the size of its mode. */
5323 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
5324 || (inter_float && inside_float))
5325 && inter_prec >= inside_prec
5326 && (inter_float || inter_unsignedp == inside_unsignedp)
5327 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
5328 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
5330 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5332 /* If we have a sign-extension of a zero-extended value, we can
5333 replace that by a single zero-extension. */
5334 if (inside_int && inter_int && final_int
5335 && inside_prec < inter_prec && inter_prec < final_prec
5336 && inside_unsignedp && !inter_unsignedp)
5337 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5339 /* Two conversions in a row are not needed unless:
5340 - some conversion is floating-point (overstrict for now), or
5341 - the intermediate type is narrower than both initial and
5343 - the intermediate type and innermost type differ in signedness,
5344 and the outermost type is wider than the intermediate, or
5345 - the initial type is a pointer type and the precisions of the
5346 intermediate and final types differ, or
5347 - the final type is a pointer type and the precisions of the
5348 initial and intermediate types differ. */
5349 if (! inside_float && ! inter_float && ! final_float
5350 && (inter_prec > inside_prec || inter_prec > final_prec)
5351 && ! (inside_int && inter_int
5352 && inter_unsignedp != inside_unsignedp
5353 && inter_prec < final_prec)
5354 && ((inter_unsignedp && inter_prec > inside_prec)
5355 == (final_unsignedp && final_prec > inter_prec))
5356 && ! (inside_ptr && inter_prec != final_prec)
5357 && ! (final_ptr && inside_prec != inter_prec)
5358 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
5359 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
5361 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5364 if (TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR
5365 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t, 0), 1))
5366 /* Detect assigning a bitfield. */
5367 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) == COMPONENT_REF
5368 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 1))))
5370 /* Don't leave an assignment inside a conversion
5371 unless assigning a bitfield. */
5372 tree prev = TREE_OPERAND (t, 0);
5375 TREE_OPERAND (t, 0) = TREE_OPERAND (prev, 1);
5376 /* First do the assignment, then return converted constant. */
5377 t = build (COMPOUND_EXPR, TREE_TYPE (t), prev, fold (t));
5382 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
5383 constants (if x has signed type, the sign bit cannot be set
5384 in c). This folds extension into the BIT_AND_EXPR. */
5385 if (INTEGRAL_TYPE_P (TREE_TYPE (t))
5386 && TREE_CODE (TREE_TYPE (t)) != BOOLEAN_TYPE
5387 && TREE_CODE (TREE_OPERAND (t, 0)) == BIT_AND_EXPR
5388 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 1)) == INTEGER_CST)
5390 tree and = TREE_OPERAND (t, 0);
5391 tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
5394 if (TREE_UNSIGNED (TREE_TYPE (and))
5395 || (TYPE_PRECISION (TREE_TYPE (t))
5396 <= TYPE_PRECISION (TREE_TYPE (and))))
5398 else if (TYPE_PRECISION (TREE_TYPE (and1))
5399 <= HOST_BITS_PER_WIDE_INT
5400 && host_integerp (and1, 1))
5402 unsigned HOST_WIDE_INT cst;
5404 cst = tree_low_cst (and1, 1);
5405 cst &= (HOST_WIDE_INT) -1
5406 << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
5407 change = (cst == 0);
5408 #ifdef LOAD_EXTEND_OP
5410 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
5413 tree uns = (*lang_hooks.types.unsigned_type) (TREE_TYPE (and0));
5414 and0 = convert (uns, and0);
5415 and1 = convert (uns, and1);
5420 return fold (build (BIT_AND_EXPR, TREE_TYPE (t),
5421 convert (TREE_TYPE (t), and0),
5422 convert (TREE_TYPE (t), and1)));
5427 if (TREE_CONSTANT (t) != TREE_CONSTANT (arg0))
5431 TREE_CONSTANT (t) = TREE_CONSTANT (arg0);
5435 return fold_convert (t, arg0);
5437 case VIEW_CONVERT_EXPR:
5438 if (TREE_CODE (TREE_OPERAND (t, 0)) == VIEW_CONVERT_EXPR)
5439 return build1 (VIEW_CONVERT_EXPR, type,
5440 TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5444 if (TREE_CODE (arg0) == CONSTRUCTOR
5445 && ! type_contains_placeholder_p (TREE_TYPE (arg0)))
5447 tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0));
5454 if (TREE_CONSTANT (t) != wins)
5458 TREE_CONSTANT (t) = wins;
5465 if (TREE_CODE (arg0) == INTEGER_CST)
5467 unsigned HOST_WIDE_INT low;
5469 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
5470 TREE_INT_CST_HIGH (arg0),
5472 t = build_int_2 (low, high);
5473 TREE_TYPE (t) = type;
5475 = (TREE_OVERFLOW (arg0)
5476 | force_fit_type (t, overflow && !TREE_UNSIGNED (type)));
5477 TREE_CONSTANT_OVERFLOW (t)
5478 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
5480 else if (TREE_CODE (arg0) == REAL_CST)
5481 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
5483 else if (TREE_CODE (arg0) == NEGATE_EXPR)
5484 return TREE_OPERAND (arg0, 0);
5485 /* Convert -((double)float) into (double)(-float). */
5486 else if (TREE_CODE (arg0) == NOP_EXPR
5487 && TREE_CODE (type) == REAL_TYPE)
5489 tree targ0 = strip_float_extensions (arg0);
5491 return convert (type, build1 (NEGATE_EXPR, TREE_TYPE (targ0), targ0));
5495 /* Convert - (a - b) to (b - a) for non-floating-point. */
5496 else if (TREE_CODE (arg0) == MINUS_EXPR
5497 && (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
5498 return build (MINUS_EXPR, type, TREE_OPERAND (arg0, 1),
5499 TREE_OPERAND (arg0, 0));
5501 /* Convert -f(x) into f(-x) where f is sin, tan or atan. */
5502 switch (builtin_mathfn_code (arg0))
5511 case BUILT_IN_ATANF:
5512 case BUILT_IN_ATANL:
5513 if (negate_expr_p (TREE_VALUE (TREE_OPERAND (arg0, 1))))
5515 tree fndecl, arg, arglist;
5517 fndecl = get_callee_fndecl (arg0);
5518 arg = TREE_VALUE (TREE_OPERAND (arg0, 1));
5519 arg = fold (build1 (NEGATE_EXPR, type, arg));
5520 arglist = build_tree_list (NULL_TREE, arg);
5521 return build_function_call_expr (fndecl, arglist);
5533 if (TREE_CODE (arg0) == INTEGER_CST)
5535 /* If the value is unsigned, then the absolute value is
5536 the same as the ordinary value. */
5537 if (TREE_UNSIGNED (type))
5539 /* Similarly, if the value is non-negative. */
5540 else if (INT_CST_LT (integer_minus_one_node, arg0))
5542 /* If the value is negative, then the absolute value is
5546 unsigned HOST_WIDE_INT low;
5548 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
5549 TREE_INT_CST_HIGH (arg0),
5551 t = build_int_2 (low, high);
5552 TREE_TYPE (t) = type;
5554 = (TREE_OVERFLOW (arg0)
5555 | force_fit_type (t, overflow));
5556 TREE_CONSTANT_OVERFLOW (t)
5557 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
5560 else if (TREE_CODE (arg0) == REAL_CST)
5562 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
5563 t = build_real (type,
5564 REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
5567 else if (TREE_CODE (arg0) == NEGATE_EXPR)
5568 return fold (build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0)));
5569 /* Convert fabs((double)float) into (double)fabsf(float). */
5570 else if (TREE_CODE (arg0) == NOP_EXPR
5571 && TREE_CODE (type) == REAL_TYPE)
5573 tree targ0 = strip_float_extensions (arg0);
5575 return convert (type, fold (build1 (ABS_EXPR, TREE_TYPE (targ0),
5578 else if (tree_expr_nonnegative_p (arg0))
5583 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
5584 return convert (type, arg0);
5585 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
5586 return build (COMPLEX_EXPR, type,
5587 TREE_OPERAND (arg0, 0),
5588 negate_expr (TREE_OPERAND (arg0, 1)));
5589 else if (TREE_CODE (arg0) == COMPLEX_CST)
5590 return build_complex (type, TREE_REALPART (arg0),
5591 negate_expr (TREE_IMAGPART (arg0)));
5592 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
5593 return fold (build (TREE_CODE (arg0), type,
5594 fold (build1 (CONJ_EXPR, type,
5595 TREE_OPERAND (arg0, 0))),
5596 fold (build1 (CONJ_EXPR,
5597 type, TREE_OPERAND (arg0, 1)))));
5598 else if (TREE_CODE (arg0) == CONJ_EXPR)
5599 return TREE_OPERAND (arg0, 0);
5605 t = build_int_2 (~ TREE_INT_CST_LOW (arg0),
5606 ~ TREE_INT_CST_HIGH (arg0));
5607 TREE_TYPE (t) = type;
5608 force_fit_type (t, 0);
5609 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg0);
5610 TREE_CONSTANT_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (arg0);
5612 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
5613 return TREE_OPERAND (arg0, 0);
5617 /* A + (-B) -> A - B */
5618 if (TREE_CODE (arg1) == NEGATE_EXPR)
5619 return fold (build (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5620 /* (-A) + B -> B - A */
5621 if (TREE_CODE (arg0) == NEGATE_EXPR)
5622 return fold (build (MINUS_EXPR, type, arg1, TREE_OPERAND (arg0, 0)));
5623 else if (! FLOAT_TYPE_P (type))
5625 if (integer_zerop (arg1))
5626 return non_lvalue (convert (type, arg0));
5628 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
5629 with a constant, and the two constants have no bits in common,
5630 we should treat this as a BIT_IOR_EXPR since this may produce more
5632 if (TREE_CODE (arg0) == BIT_AND_EXPR
5633 && TREE_CODE (arg1) == BIT_AND_EXPR
5634 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5635 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
5636 && integer_zerop (const_binop (BIT_AND_EXPR,
5637 TREE_OPERAND (arg0, 1),
5638 TREE_OPERAND (arg1, 1), 0)))
5640 code = BIT_IOR_EXPR;
5644 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
5645 (plus (plus (mult) (mult)) (foo)) so that we can
5646 take advantage of the factoring cases below. */
5647 if ((TREE_CODE (arg0) == PLUS_EXPR
5648 && TREE_CODE (arg1) == MULT_EXPR)
5649 || (TREE_CODE (arg1) == PLUS_EXPR
5650 && TREE_CODE (arg0) == MULT_EXPR))
5652 tree parg0, parg1, parg, marg;
5654 if (TREE_CODE (arg0) == PLUS_EXPR)
5655 parg = arg0, marg = arg1;
5657 parg = arg1, marg = arg0;
5658 parg0 = TREE_OPERAND (parg, 0);
5659 parg1 = TREE_OPERAND (parg, 1);
5663 if (TREE_CODE (parg0) == MULT_EXPR
5664 && TREE_CODE (parg1) != MULT_EXPR)
5665 return fold (build (PLUS_EXPR, type,
5666 fold (build (PLUS_EXPR, type,
5667 convert (type, parg0),
5668 convert (type, marg))),
5669 convert (type, parg1)));
5670 if (TREE_CODE (parg0) != MULT_EXPR
5671 && TREE_CODE (parg1) == MULT_EXPR)
5672 return fold (build (PLUS_EXPR, type,
5673 fold (build (PLUS_EXPR, type,
5674 convert (type, parg1),
5675 convert (type, marg))),
5676 convert (type, parg0)));
5679 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR)
5681 tree arg00, arg01, arg10, arg11;
5682 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
5684 /* (A * C) + (B * C) -> (A+B) * C.
5685 We are most concerned about the case where C is a constant,
5686 but other combinations show up during loop reduction. Since
5687 it is not difficult, try all four possibilities. */
5689 arg00 = TREE_OPERAND (arg0, 0);
5690 arg01 = TREE_OPERAND (arg0, 1);
5691 arg10 = TREE_OPERAND (arg1, 0);
5692 arg11 = TREE_OPERAND (arg1, 1);
5695 if (operand_equal_p (arg01, arg11, 0))
5696 same = arg01, alt0 = arg00, alt1 = arg10;
5697 else if (operand_equal_p (arg00, arg10, 0))
5698 same = arg00, alt0 = arg01, alt1 = arg11;
5699 else if (operand_equal_p (arg00, arg11, 0))
5700 same = arg00, alt0 = arg01, alt1 = arg10;
5701 else if (operand_equal_p (arg01, arg10, 0))
5702 same = arg01, alt0 = arg00, alt1 = arg11;
5704 /* No identical multiplicands; see if we can find a common
5705 power-of-two factor in non-power-of-two multiplies. This
5706 can help in multi-dimensional array access. */
5707 else if (TREE_CODE (arg01) == INTEGER_CST
5708 && TREE_CODE (arg11) == INTEGER_CST
5709 && TREE_INT_CST_HIGH (arg01) == 0
5710 && TREE_INT_CST_HIGH (arg11) == 0)
5712 HOST_WIDE_INT int01, int11, tmp;
5713 int01 = TREE_INT_CST_LOW (arg01);
5714 int11 = TREE_INT_CST_LOW (arg11);
5716 /* Move min of absolute values to int11. */
5717 if ((int01 >= 0 ? int01 : -int01)
5718 < (int11 >= 0 ? int11 : -int11))
5720 tmp = int01, int01 = int11, int11 = tmp;
5721 alt0 = arg00, arg00 = arg10, arg10 = alt0;
5722 alt0 = arg01, arg01 = arg11, arg11 = alt0;
5725 if (exact_log2 (int11) > 0 && int01 % int11 == 0)
5727 alt0 = fold (build (MULT_EXPR, type, arg00,
5728 build_int_2 (int01 / int11, 0)));
5735 return fold (build (MULT_EXPR, type,
5736 fold (build (PLUS_EXPR, type, alt0, alt1)),
5742 /* See if ARG1 is zero and X + ARG1 reduces to X. */
5743 if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
5744 return non_lvalue (convert (type, arg0));
5746 /* Likewise if the operands are reversed. */
5747 if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
5748 return non_lvalue (convert (type, arg1));
5750 /* Convert x+x into x*2.0. */
5751 if (operand_equal_p (arg0, arg1, 0)
5752 && SCALAR_FLOAT_TYPE_P (type))
5753 return fold (build (MULT_EXPR, type, arg0,
5754 build_real (type, dconst2)));
5756 /* Convert x*c+x into x*(c+1). */
5757 if (flag_unsafe_math_optimizations
5758 && TREE_CODE (arg0) == MULT_EXPR
5759 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
5760 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0, 1))
5761 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
5765 c = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
5766 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
5767 return fold (build (MULT_EXPR, type, arg1,
5768 build_real (type, c)));
5771 /* Convert x+x*c into x*(c+1). */
5772 if (flag_unsafe_math_optimizations
5773 && TREE_CODE (arg1) == MULT_EXPR
5774 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST
5775 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1, 1))
5776 && operand_equal_p (TREE_OPERAND (arg1, 0), arg0, 0))
5780 c = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
5781 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
5782 return fold (build (MULT_EXPR, type, arg0,
5783 build_real (type, c)));
5786 /* Convert x*c1+x*c2 into x*(c1+c2). */
5787 if (flag_unsafe_math_optimizations
5788 && TREE_CODE (arg0) == MULT_EXPR
5789 && TREE_CODE (arg1) == MULT_EXPR
5790 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
5791 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0, 1))
5792 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST
5793 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1, 1))
5794 && operand_equal_p (TREE_OPERAND (arg0, 0),
5795 TREE_OPERAND (arg1, 0), 0))
5797 REAL_VALUE_TYPE c1, c2;
5799 c1 = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
5800 c2 = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
5801 real_arithmetic (&c1, PLUS_EXPR, &c1, &c2);
5802 return fold (build (MULT_EXPR, type,
5803 TREE_OPERAND (arg0, 0),
5804 build_real (type, c1)));
5809 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
5810 is a rotate of A by C1 bits. */
5811 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
5812 is a rotate of A by B bits. */
5814 enum tree_code code0, code1;
5815 code0 = TREE_CODE (arg0);
5816 code1 = TREE_CODE (arg1);
5817 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
5818 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
5819 && operand_equal_p (TREE_OPERAND (arg0, 0),
5820 TREE_OPERAND (arg1, 0), 0)
5821 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5823 tree tree01, tree11;
5824 enum tree_code code01, code11;
5826 tree01 = TREE_OPERAND (arg0, 1);
5827 tree11 = TREE_OPERAND (arg1, 1);
5828 STRIP_NOPS (tree01);
5829 STRIP_NOPS (tree11);
5830 code01 = TREE_CODE (tree01);
5831 code11 = TREE_CODE (tree11);
5832 if (code01 == INTEGER_CST
5833 && code11 == INTEGER_CST
5834 && TREE_INT_CST_HIGH (tree01) == 0
5835 && TREE_INT_CST_HIGH (tree11) == 0
5836 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
5837 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
5838 return build (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
5839 code0 == LSHIFT_EXPR ? tree01 : tree11);
5840 else if (code11 == MINUS_EXPR)
5842 tree tree110, tree111;
5843 tree110 = TREE_OPERAND (tree11, 0);
5844 tree111 = TREE_OPERAND (tree11, 1);
5845 STRIP_NOPS (tree110);
5846 STRIP_NOPS (tree111);
5847 if (TREE_CODE (tree110) == INTEGER_CST
5848 && 0 == compare_tree_int (tree110,
5850 (TREE_TYPE (TREE_OPERAND
5852 && operand_equal_p (tree01, tree111, 0))
5853 return build ((code0 == LSHIFT_EXPR
5856 type, TREE_OPERAND (arg0, 0), tree01);
5858 else if (code01 == MINUS_EXPR)
5860 tree tree010, tree011;
5861 tree010 = TREE_OPERAND (tree01, 0);
5862 tree011 = TREE_OPERAND (tree01, 1);
5863 STRIP_NOPS (tree010);
5864 STRIP_NOPS (tree011);
5865 if (TREE_CODE (tree010) == INTEGER_CST
5866 && 0 == compare_tree_int (tree010,
5868 (TREE_TYPE (TREE_OPERAND
5870 && operand_equal_p (tree11, tree011, 0))
5871 return build ((code0 != LSHIFT_EXPR
5874 type, TREE_OPERAND (arg0, 0), tree11);
5880 /* In most languages, can't associate operations on floats through
5881 parentheses. Rather than remember where the parentheses were, we
5882 don't associate floats at all, unless the user has specified
5883 -funsafe-math-optimizations. */
5886 && (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
5888 tree var0, con0, lit0, minus_lit0;
5889 tree var1, con1, lit1, minus_lit1;
5891 /* Split both trees into variables, constants, and literals. Then
5892 associate each group together, the constants with literals,
5893 then the result with variables. This increases the chances of
5894 literals being recombined later and of generating relocatable
5895 expressions for the sum of a constant and literal. */
5896 var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
5897 var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
5898 code == MINUS_EXPR);
5900 /* Only do something if we found more than two objects. Otherwise,
5901 nothing has changed and we risk infinite recursion. */
5902 if (2 < ((var0 != 0) + (var1 != 0)
5903 + (con0 != 0) + (con1 != 0)
5904 + (lit0 != 0) + (lit1 != 0)
5905 + (minus_lit0 != 0) + (minus_lit1 != 0)))
5907 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
5908 if (code == MINUS_EXPR)
5911 var0 = associate_trees (var0, var1, code, type);
5912 con0 = associate_trees (con0, con1, code, type);
5913 lit0 = associate_trees (lit0, lit1, code, type);
5914 minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
5916 /* Preserve the MINUS_EXPR if the negative part of the literal is
5917 greater than the positive part. Otherwise, the multiplicative
5918 folding code (i.e extract_muldiv) may be fooled in case
5919 unsigned constants are subtracted, like in the following
5920 example: ((X*2 + 4) - 8U)/2. */
5921 if (minus_lit0 && lit0)
5923 if (TREE_CODE (lit0) == INTEGER_CST
5924 && TREE_CODE (minus_lit0) == INTEGER_CST
5925 && tree_int_cst_lt (lit0, minus_lit0))
5927 minus_lit0 = associate_trees (minus_lit0, lit0,
5933 lit0 = associate_trees (lit0, minus_lit0,
5941 return convert (type, associate_trees (var0, minus_lit0,
5945 con0 = associate_trees (con0, minus_lit0,
5947 return convert (type, associate_trees (var0, con0,
5952 con0 = associate_trees (con0, lit0, code, type);
5953 return convert (type, associate_trees (var0, con0, code, type));
5959 t1 = const_binop (code, arg0, arg1, 0);
5960 if (t1 != NULL_TREE)
5962 /* The return value should always have
5963 the same type as the original expression. */
5964 if (TREE_TYPE (t1) != TREE_TYPE (t))
5965 t1 = convert (TREE_TYPE (t), t1);
5972 /* A - (-B) -> A + B */
5973 if (TREE_CODE (arg1) == NEGATE_EXPR)
5974 return fold (build (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5975 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
5976 if (TREE_CODE (arg0) == NEGATE_EXPR
5977 && (FLOAT_TYPE_P (type)
5978 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv))
5979 && negate_expr_p (arg1)
5980 && (! TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
5981 && (! TREE_SIDE_EFFECTS (arg1) || TREE_CONSTANT (arg0)))
5982 return fold (build (MINUS_EXPR, type, negate_expr (arg1),
5983 TREE_OPERAND (arg0, 0)));
5985 if (! FLOAT_TYPE_P (type))
5987 if (! wins && integer_zerop (arg0))
5988 return negate_expr (convert (type, arg1));
5989 if (integer_zerop (arg1))
5990 return non_lvalue (convert (type, arg0));
5992 /* (A * C) - (B * C) -> (A-B) * C. Since we are most concerned
5993 about the case where C is a constant, just try one of the
5994 four possibilities. */
5996 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR
5997 && operand_equal_p (TREE_OPERAND (arg0, 1),
5998 TREE_OPERAND (arg1, 1), 0))
5999 return fold (build (MULT_EXPR, type,
6000 fold (build (MINUS_EXPR, type,
6001 TREE_OPERAND (arg0, 0),
6002 TREE_OPERAND (arg1, 0))),
6003 TREE_OPERAND (arg0, 1)));
6005 /* Fold A - (A & B) into ~B & A. */
6006 if (!TREE_SIDE_EFFECTS (arg0)
6007 && TREE_CODE (arg1) == BIT_AND_EXPR)
6009 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
6010 return fold (build (BIT_AND_EXPR, type,
6011 fold (build1 (BIT_NOT_EXPR, type,
6012 TREE_OPERAND (arg1, 0))),
6014 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
6015 return fold (build (BIT_AND_EXPR, type,
6016 fold (build1 (BIT_NOT_EXPR, type,
6017 TREE_OPERAND (arg1, 1))),
6021 /* Fold (A & ~B) - (A & B) into (A ^ B) - B, , where B is
6022 any power of 2 minus 1. */
6023 if (TREE_CODE (arg0) == BIT_AND_EXPR
6024 && TREE_CODE (arg1) == BIT_AND_EXPR
6025 && operand_equal_p (TREE_OPERAND (arg0, 0),
6026 TREE_OPERAND (arg1, 0), 0)
6027 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6028 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST)
6030 tree mask0 = TREE_OPERAND (arg0, 1);
6031 tree mask1 = TREE_OPERAND (arg1, 1);
6032 tree tem = fold (build1 (BIT_NOT_EXPR, type, mask0));
6034 if (operand_equal_p (tem, mask1, 0)
6035 && integer_pow2p (fold (build (PLUS_EXPR, type,
6036 mask1, integer_one_node))))
6038 tem = fold (build (BIT_XOR_EXPR, type,
6039 TREE_OPERAND (arg0, 0), mask1));
6040 return fold (build (MINUS_EXPR, type, tem, mask1));
6045 /* See if ARG1 is zero and X - ARG1 reduces to X. */
6046 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
6047 return non_lvalue (convert (type, arg0));
6049 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
6050 ARG0 is zero and X + ARG0 reduces to X, since that would mean
6051 (-ARG1 + ARG0) reduces to -ARG1. */
6052 else if (!wins && fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
6053 return negate_expr (convert (type, arg1));
6055 /* Fold &x - &x. This can happen from &x.foo - &x.
6056 This is unsafe for certain floats even in non-IEEE formats.
6057 In IEEE, it is unsafe because it does wrong for NaNs.
6058 Also note that operand_equal_p is always false if an operand
6061 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
6062 && operand_equal_p (arg0, arg1, 0))
6063 return convert (type, integer_zero_node);
6068 /* (-A) * (-B) -> A * B */
6069 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
6070 return fold (build (MULT_EXPR, type,
6071 TREE_OPERAND (arg0, 0),
6072 negate_expr (arg1)));
6073 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
6074 return fold (build (MULT_EXPR, type,
6076 TREE_OPERAND (arg1, 0)));
6078 if (! FLOAT_TYPE_P (type))
6080 if (integer_zerop (arg1))
6081 return omit_one_operand (type, arg1, arg0);
6082 if (integer_onep (arg1))
6083 return non_lvalue (convert (type, arg0));
6085 /* (a * (1 << b)) is (a << b) */
6086 if (TREE_CODE (arg1) == LSHIFT_EXPR
6087 && integer_onep (TREE_OPERAND (arg1, 0)))
6088 return fold (build (LSHIFT_EXPR, type, arg0,
6089 TREE_OPERAND (arg1, 1)));
6090 if (TREE_CODE (arg0) == LSHIFT_EXPR
6091 && integer_onep (TREE_OPERAND (arg0, 0)))
6092 return fold (build (LSHIFT_EXPR, type, arg1,
6093 TREE_OPERAND (arg0, 1)));
6095 if (TREE_CODE (arg1) == INTEGER_CST
6096 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0),
6097 convert (type, arg1),
6099 return convert (type, tem);
6104 /* Maybe fold x * 0 to 0. The expressions aren't the same
6105 when x is NaN, since x * 0 is also NaN. Nor are they the
6106 same in modes with signed zeros, since multiplying a
6107 negative value by 0 gives -0, not +0. */
6108 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
6109 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
6110 && real_zerop (arg1))
6111 return omit_one_operand (type, arg1, arg0);
6112 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
6113 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
6114 && real_onep (arg1))
6115 return non_lvalue (convert (type, arg0));
6117 /* Transform x * -1.0 into -x. */
6118 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
6119 && real_minus_onep (arg1))
6120 return fold (build1 (NEGATE_EXPR, type, arg0));
6122 /* Convert (C1/X)*C2 into (C1*C2)/X. */
6123 if (flag_unsafe_math_optimizations
6124 && TREE_CODE (arg0) == RDIV_EXPR
6125 && TREE_CODE (arg1) == REAL_CST
6126 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST)
6128 tree tem = const_binop (MULT_EXPR, TREE_OPERAND (arg0, 0),
6131 return fold (build (RDIV_EXPR, type, tem,
6132 TREE_OPERAND (arg0, 1)));
6135 if (flag_unsafe_math_optimizations)
6137 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
6138 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
6140 /* Optimizations of sqrt(...)*sqrt(...). */
6141 if ((fcode0 == BUILT_IN_SQRT && fcode1 == BUILT_IN_SQRT)
6142 || (fcode0 == BUILT_IN_SQRTF && fcode1 == BUILT_IN_SQRTF)
6143 || (fcode0 == BUILT_IN_SQRTL && fcode1 == BUILT_IN_SQRTL))
6145 tree sqrtfn, arg, arglist;
6146 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
6147 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
6149 /* Optimize sqrt(x)*sqrt(x) as x. */
6150 if (operand_equal_p (arg00, arg10, 0)
6151 && ! HONOR_SNANS (TYPE_MODE (type)))
6154 /* Optimize sqrt(x)*sqrt(y) as sqrt(x*y). */
6155 sqrtfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
6156 arg = fold (build (MULT_EXPR, type, arg00, arg10));
6157 arglist = build_tree_list (NULL_TREE, arg);
6158 return build_function_call_expr (sqrtfn, arglist);
6161 /* Optimize expN(x)*expN(y) as expN(x+y). */
6162 if (fcode0 == fcode1
6163 && (fcode0 == BUILT_IN_EXP
6164 || fcode0 == BUILT_IN_EXPF
6165 || fcode0 == BUILT_IN_EXPL
6166 || fcode0 == BUILT_IN_EXP2
6167 || fcode0 == BUILT_IN_EXP2F
6168 || fcode0 == BUILT_IN_EXP2L
6169 || fcode0 == BUILT_IN_EXP10
6170 || fcode0 == BUILT_IN_EXP10F
6171 || fcode0 == BUILT_IN_EXP10L
6172 || fcode0 == BUILT_IN_POW10
6173 || fcode0 == BUILT_IN_POW10F
6174 || fcode0 == BUILT_IN_POW10L))
6176 tree expfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
6177 tree arg = build (PLUS_EXPR, type,
6178 TREE_VALUE (TREE_OPERAND (arg0, 1)),
6179 TREE_VALUE (TREE_OPERAND (arg1, 1)));
6180 tree arglist = build_tree_list (NULL_TREE, fold (arg));
6181 return build_function_call_expr (expfn, arglist);
6184 /* Optimizations of pow(...)*pow(...). */
6185 if ((fcode0 == BUILT_IN_POW && fcode1 == BUILT_IN_POW)
6186 || (fcode0 == BUILT_IN_POWF && fcode1 == BUILT_IN_POWF)
6187 || (fcode0 == BUILT_IN_POWL && fcode1 == BUILT_IN_POWL))
6189 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
6190 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
6192 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
6193 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
6196 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
6197 if (operand_equal_p (arg01, arg11, 0))
6199 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
6200 tree arg = build (MULT_EXPR, type, arg00, arg10);
6201 tree arglist = tree_cons (NULL_TREE, fold (arg),
6202 build_tree_list (NULL_TREE,
6204 return build_function_call_expr (powfn, arglist);
6207 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
6208 if (operand_equal_p (arg00, arg10, 0))
6210 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
6211 tree arg = fold (build (PLUS_EXPR, type, arg01, arg11));
6212 tree arglist = tree_cons (NULL_TREE, arg00,
6213 build_tree_list (NULL_TREE,
6215 return build_function_call_expr (powfn, arglist);
6219 /* Optimize tan(x)*cos(x) as sin(x). */
6220 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_COS)
6221 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_COSF)
6222 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_COSL)
6223 || (fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_TAN)
6224 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_TANF)
6225 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_TANL))
6226 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
6227 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
6235 sinfn = implicit_built_in_decls[BUILT_IN_SIN];
6239 sinfn = implicit_built_in_decls[BUILT_IN_SINF];
6243 sinfn = implicit_built_in_decls[BUILT_IN_SINL];
6249 if (sinfn != NULL_TREE)
6250 return build_function_call_expr (sinfn,
6251 TREE_OPERAND (arg0, 1));
6254 /* Optimize x*pow(x,c) as pow(x,c+1). */
6255 if (fcode1 == BUILT_IN_POW
6256 || fcode1 == BUILT_IN_POWF
6257 || fcode1 == BUILT_IN_POWL)
6259 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
6260 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
6262 if (TREE_CODE (arg11) == REAL_CST
6263 && ! TREE_CONSTANT_OVERFLOW (arg11)
6264 && operand_equal_p (arg0, arg10, 0))
6266 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
6270 c = TREE_REAL_CST (arg11);
6271 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
6272 arg = build_real (type, c);
6273 arglist = build_tree_list (NULL_TREE, arg);
6274 arglist = tree_cons (NULL_TREE, arg0, arglist);
6275 return build_function_call_expr (powfn, arglist);
6279 /* Optimize pow(x,c)*x as pow(x,c+1). */
6280 if (fcode0 == BUILT_IN_POW
6281 || fcode0 == BUILT_IN_POWF
6282 || fcode0 == BUILT_IN_POWL)
6284 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
6285 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
6287 if (TREE_CODE (arg01) == REAL_CST
6288 && ! TREE_CONSTANT_OVERFLOW (arg01)
6289 && operand_equal_p (arg1, arg00, 0))
6291 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
6295 c = TREE_REAL_CST (arg01);
6296 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
6297 arg = build_real (type, c);
6298 arglist = build_tree_list (NULL_TREE, arg);
6299 arglist = tree_cons (NULL_TREE, arg1, arglist);
6300 return build_function_call_expr (powfn, arglist);
6304 /* Optimize x*x as pow(x,2.0), which is expanded as x*x. */
6306 && operand_equal_p (arg0, arg1, 0))
6310 if (type == double_type_node)
6311 powfn = implicit_built_in_decls[BUILT_IN_POW];
6312 else if (type == float_type_node)
6313 powfn = implicit_built_in_decls[BUILT_IN_POWF];
6314 else if (type == long_double_type_node)
6315 powfn = implicit_built_in_decls[BUILT_IN_POWL];
6321 tree arg = build_real (type, dconst2);
6322 tree arglist = build_tree_list (NULL_TREE, arg);
6323 arglist = tree_cons (NULL_TREE, arg0, arglist);
6324 return build_function_call_expr (powfn, arglist);
6333 if (integer_all_onesp (arg1))
6334 return omit_one_operand (type, arg1, arg0);
6335 if (integer_zerop (arg1))
6336 return non_lvalue (convert (type, arg0));
6337 t1 = distribute_bit_expr (code, type, arg0, arg1);
6338 if (t1 != NULL_TREE)
6341 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
6343 This results in more efficient code for machines without a NAND
6344 instruction. Combine will canonicalize to the first form
6345 which will allow use of NAND instructions provided by the
6346 backend if they exist. */
6347 if (TREE_CODE (arg0) == BIT_NOT_EXPR
6348 && TREE_CODE (arg1) == BIT_NOT_EXPR)
6350 return fold (build1 (BIT_NOT_EXPR, type,
6351 build (BIT_AND_EXPR, type,
6352 TREE_OPERAND (arg0, 0),
6353 TREE_OPERAND (arg1, 0))));
6356 /* See if this can be simplified into a rotate first. If that
6357 is unsuccessful continue in the association code. */
6361 if (integer_zerop (arg1))
6362 return non_lvalue (convert (type, arg0));
6363 if (integer_all_onesp (arg1))
6364 return fold (build1 (BIT_NOT_EXPR, type, arg0));
6366 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
6367 with a constant, and the two constants have no bits in common,
6368 we should treat this as a BIT_IOR_EXPR since this may produce more
6370 if (TREE_CODE (arg0) == BIT_AND_EXPR
6371 && TREE_CODE (arg1) == BIT_AND_EXPR
6372 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6373 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
6374 && integer_zerop (const_binop (BIT_AND_EXPR,
6375 TREE_OPERAND (arg0, 1),
6376 TREE_OPERAND (arg1, 1), 0)))
6378 code = BIT_IOR_EXPR;
6382 /* See if this can be simplified into a rotate first. If that
6383 is unsuccessful continue in the association code. */
6387 if (integer_all_onesp (arg1))
6388 return non_lvalue (convert (type, arg0));
6389 if (integer_zerop (arg1))
6390 return omit_one_operand (type, arg1, arg0);
6391 t1 = distribute_bit_expr (code, type, arg0, arg1);
6392 if (t1 != NULL_TREE)
6394 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
6395 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
6396 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
6399 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
6401 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
6402 && (~TREE_INT_CST_LOW (arg1)
6403 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
6404 return build1 (NOP_EXPR, type, TREE_OPERAND (arg0, 0));
6407 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
6409 This results in more efficient code for machines without a NOR
6410 instruction. Combine will canonicalize to the first form
6411 which will allow use of NOR instructions provided by the
6412 backend if they exist. */
6413 if (TREE_CODE (arg0) == BIT_NOT_EXPR
6414 && TREE_CODE (arg1) == BIT_NOT_EXPR)
6416 return fold (build1 (BIT_NOT_EXPR, type,
6417 build (BIT_IOR_EXPR, type,
6418 TREE_OPERAND (arg0, 0),
6419 TREE_OPERAND (arg1, 0))));
6425 /* Don't touch a floating-point divide by zero unless the mode
6426 of the constant can represent infinity. */
6427 if (TREE_CODE (arg1) == REAL_CST
6428 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
6429 && real_zerop (arg1))
6432 /* (-A) / (-B) -> A / B */
6433 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
6434 return fold (build (RDIV_EXPR, type,
6435 TREE_OPERAND (arg0, 0),
6436 negate_expr (arg1)));
6437 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
6438 return fold (build (RDIV_EXPR, type,
6440 TREE_OPERAND (arg1, 0)));
6442 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
6443 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
6444 && real_onep (arg1))
6445 return non_lvalue (convert (type, arg0));
6447 /* In IEEE floating point, x/-1 is not equivalent to -x for snans. */
6448 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
6449 && real_minus_onep (arg1))
6450 return non_lvalue (convert (type, negate_expr (arg0)));
6452 /* If ARG1 is a constant, we can convert this to a multiply by the
6453 reciprocal. This does not have the same rounding properties,
6454 so only do this if -funsafe-math-optimizations. We can actually
6455 always safely do it if ARG1 is a power of two, but it's hard to
6456 tell if it is or not in a portable manner. */
6457 if (TREE_CODE (arg1) == REAL_CST)
6459 if (flag_unsafe_math_optimizations
6460 && 0 != (tem = const_binop (code, build_real (type, dconst1),
6462 return fold (build (MULT_EXPR, type, arg0, tem));
6463 /* Find the reciprocal if optimizing and the result is exact. */
6467 r = TREE_REAL_CST (arg1);
6468 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
6470 tem = build_real (type, r);
6471 return fold (build (MULT_EXPR, type, arg0, tem));
6475 /* Convert A/B/C to A/(B*C). */
6476 if (flag_unsafe_math_optimizations
6477 && TREE_CODE (arg0) == RDIV_EXPR)
6478 return fold (build (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
6479 fold (build (MULT_EXPR, type,
6480 TREE_OPERAND (arg0, 1), arg1))));
6482 /* Convert A/(B/C) to (A/B)*C. */
6483 if (flag_unsafe_math_optimizations
6484 && TREE_CODE (arg1) == RDIV_EXPR)
6485 return fold (build (MULT_EXPR, type,
6486 fold (build (RDIV_EXPR, type, arg0,
6487 TREE_OPERAND (arg1, 0))),
6488 TREE_OPERAND (arg1, 1)));
6490 /* Convert C1/(X*C2) into (C1/C2)/X. */
6491 if (flag_unsafe_math_optimizations
6492 && TREE_CODE (arg1) == MULT_EXPR
6493 && TREE_CODE (arg0) == REAL_CST
6494 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
6496 tree tem = const_binop (RDIV_EXPR, arg0,
6497 TREE_OPERAND (arg1, 1), 0);
6499 return fold (build (RDIV_EXPR, type, tem,
6500 TREE_OPERAND (arg1, 0)));
6503 if (flag_unsafe_math_optimizations)
6505 enum built_in_function fcode = builtin_mathfn_code (arg1);
6506 /* Optimize x/expN(y) into x*expN(-y). */
6507 if (fcode == BUILT_IN_EXP
6508 || fcode == BUILT_IN_EXPF
6509 || fcode == BUILT_IN_EXPL
6510 || fcode == BUILT_IN_EXP2
6511 || fcode == BUILT_IN_EXP2F
6512 || fcode == BUILT_IN_EXP2L
6513 || fcode == BUILT_IN_EXP10
6514 || fcode == BUILT_IN_EXP10F
6515 || fcode == BUILT_IN_EXP10L
6516 || fcode == BUILT_IN_POW10
6517 || fcode == BUILT_IN_POW10F
6518 || fcode == BUILT_IN_POW10L)
6520 tree expfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
6521 tree arg = build1 (NEGATE_EXPR, type,
6522 TREE_VALUE (TREE_OPERAND (arg1, 1)));
6523 tree arglist = build_tree_list (NULL_TREE, fold (arg));
6524 arg1 = build_function_call_expr (expfn, arglist);
6525 return fold (build (MULT_EXPR, type, arg0, arg1));
6528 /* Optimize x/pow(y,z) into x*pow(y,-z). */
6529 if (fcode == BUILT_IN_POW
6530 || fcode == BUILT_IN_POWF
6531 || fcode == BUILT_IN_POWL)
6533 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
6534 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
6535 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1, 1)));
6536 tree neg11 = fold (build1 (NEGATE_EXPR, type, arg11));
6537 tree arglist = tree_cons(NULL_TREE, arg10,
6538 build_tree_list (NULL_TREE, neg11));
6539 arg1 = build_function_call_expr (powfn, arglist);
6540 return fold (build (MULT_EXPR, type, arg0, arg1));
6544 if (flag_unsafe_math_optimizations)
6546 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
6547 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
6549 /* Optimize sin(x)/cos(x) as tan(x). */
6550 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_COS)
6551 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_COSF)
6552 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_COSL))
6553 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
6554 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
6558 if (fcode0 == BUILT_IN_SIN)
6559 tanfn = implicit_built_in_decls[BUILT_IN_TAN];
6560 else if (fcode0 == BUILT_IN_SINF)
6561 tanfn = implicit_built_in_decls[BUILT_IN_TANF];
6562 else if (fcode0 == BUILT_IN_SINL)
6563 tanfn = implicit_built_in_decls[BUILT_IN_TANL];
6567 if (tanfn != NULL_TREE)
6568 return build_function_call_expr (tanfn,
6569 TREE_OPERAND (arg0, 1));
6572 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
6573 if (((fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_SIN)
6574 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_SINF)
6575 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_SINL))
6576 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
6577 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
6581 if (fcode0 == BUILT_IN_COS)
6582 tanfn = implicit_built_in_decls[BUILT_IN_TAN];
6583 else if (fcode0 == BUILT_IN_COSF)
6584 tanfn = implicit_built_in_decls[BUILT_IN_TANF];
6585 else if (fcode0 == BUILT_IN_COSL)
6586 tanfn = implicit_built_in_decls[BUILT_IN_TANL];
6590 if (tanfn != NULL_TREE)
6592 tree tmp = TREE_OPERAND (arg0, 1);
6593 tmp = build_function_call_expr (tanfn, tmp);
6594 return fold (build (RDIV_EXPR, type,
6595 build_real (type, dconst1),
6600 /* Optimize pow(x,c)/x as pow(x,c-1). */
6601 if (fcode0 == BUILT_IN_POW
6602 || fcode0 == BUILT_IN_POWF
6603 || fcode0 == BUILT_IN_POWL)
6605 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
6606 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0, 1)));
6607 if (TREE_CODE (arg01) == REAL_CST
6608 && ! TREE_CONSTANT_OVERFLOW (arg01)
6609 && operand_equal_p (arg1, arg00, 0))
6611 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
6615 c = TREE_REAL_CST (arg01);
6616 real_arithmetic (&c, MINUS_EXPR, &c, &dconst1);
6617 arg = build_real (type, c);
6618 arglist = build_tree_list (NULL_TREE, arg);
6619 arglist = tree_cons (NULL_TREE, arg1, arglist);
6620 return build_function_call_expr (powfn, arglist);
6626 case TRUNC_DIV_EXPR:
6627 case ROUND_DIV_EXPR:
6628 case FLOOR_DIV_EXPR:
6630 case EXACT_DIV_EXPR:
6631 if (integer_onep (arg1))
6632 return non_lvalue (convert (type, arg0));
6633 if (integer_zerop (arg1))
6636 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
6637 operation, EXACT_DIV_EXPR.
6639 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
6640 At one time others generated faster code, it's not clear if they do
6641 after the last round to changes to the DIV code in expmed.c. */
6642 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
6643 && multiple_of_p (type, arg0, arg1))
6644 return fold (build (EXACT_DIV_EXPR, type, arg0, arg1));
6646 if (TREE_CODE (arg1) == INTEGER_CST
6647 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
6649 return convert (type, tem);
6654 case FLOOR_MOD_EXPR:
6655 case ROUND_MOD_EXPR:
6656 case TRUNC_MOD_EXPR:
6657 if (integer_onep (arg1))
6658 return omit_one_operand (type, integer_zero_node, arg0);
6659 if (integer_zerop (arg1))
6662 if (TREE_CODE (arg1) == INTEGER_CST
6663 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
6665 return convert (type, tem);
6671 if (integer_all_onesp (arg0))
6672 return omit_one_operand (type, arg0, arg1);
6676 /* Optimize -1 >> x for arithmetic right shifts. */
6677 if (integer_all_onesp (arg0) && ! TREE_UNSIGNED (type))
6678 return omit_one_operand (type, arg0, arg1);
6679 /* ... fall through ... */
6683 if (integer_zerop (arg1))
6684 return non_lvalue (convert (type, arg0));
6685 if (integer_zerop (arg0))
6686 return omit_one_operand (type, arg0, arg1);
6688 /* Since negative shift count is not well-defined,
6689 don't try to compute it in the compiler. */
6690 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
6692 /* Rewrite an LROTATE_EXPR by a constant into an
6693 RROTATE_EXPR by a new constant. */
6694 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
6696 tree tem = build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type)), 0);
6697 tem = convert (TREE_TYPE (arg1), tem);
6698 tem = const_binop (MINUS_EXPR, tem, arg1, 0);
6699 return fold (build (RROTATE_EXPR, type, arg0, tem));
6702 /* If we have a rotate of a bit operation with the rotate count and
6703 the second operand of the bit operation both constant,
6704 permute the two operations. */
6705 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
6706 && (TREE_CODE (arg0) == BIT_AND_EXPR
6707 || TREE_CODE (arg0) == BIT_IOR_EXPR
6708 || TREE_CODE (arg0) == BIT_XOR_EXPR)
6709 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
6710 return fold (build (TREE_CODE (arg0), type,
6711 fold (build (code, type,
6712 TREE_OPERAND (arg0, 0), arg1)),
6713 fold (build (code, type,
6714 TREE_OPERAND (arg0, 1), arg1))));
6716 /* Two consecutive rotates adding up to the width of the mode can
6718 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
6719 && TREE_CODE (arg0) == RROTATE_EXPR
6720 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6721 && TREE_INT_CST_HIGH (arg1) == 0
6722 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
6723 && ((TREE_INT_CST_LOW (arg1)
6724 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
6725 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type))))
6726 return TREE_OPERAND (arg0, 0);
6731 if (operand_equal_p (arg0, arg1, 0))
6732 return omit_one_operand (type, arg0, arg1);
6733 if (INTEGRAL_TYPE_P (type)
6734 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), 1))
6735 return omit_one_operand (type, arg1, arg0);
6739 if (operand_equal_p (arg0, arg1, 0))
6740 return omit_one_operand (type, arg0, arg1);
6741 if (INTEGRAL_TYPE_P (type)
6742 && TYPE_MAX_VALUE (type)
6743 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), 1))
6744 return omit_one_operand (type, arg1, arg0);
6747 case TRUTH_NOT_EXPR:
6748 /* Note that the operand of this must be an int
6749 and its values must be 0 or 1.
6750 ("true" is a fixed value perhaps depending on the language,
6751 but we don't handle values other than 1 correctly yet.) */
6752 tem = invert_truthvalue (arg0);
6753 /* Avoid infinite recursion. */
6754 if (TREE_CODE (tem) == TRUTH_NOT_EXPR)
6756 tem = fold_single_bit_test (code, arg0, arg1, type);
6761 return convert (type, tem);
6763 case TRUTH_ANDIF_EXPR:
6764 /* Note that the operands of this must be ints
6765 and their values must be 0 or 1.
6766 ("true" is a fixed value perhaps depending on the language.) */
6767 /* If first arg is constant zero, return it. */
6768 if (integer_zerop (arg0))
6769 return convert (type, arg0);
6770 case TRUTH_AND_EXPR:
6771 /* If either arg is constant true, drop it. */
6772 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
6773 return non_lvalue (convert (type, arg1));
6774 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
6775 /* Preserve sequence points. */
6776 && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
6777 return non_lvalue (convert (type, arg0));
6778 /* If second arg is constant zero, result is zero, but first arg
6779 must be evaluated. */
6780 if (integer_zerop (arg1))
6781 return omit_one_operand (type, arg1, arg0);
6782 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
6783 case will be handled here. */
6784 if (integer_zerop (arg0))
6785 return omit_one_operand (type, arg0, arg1);
6788 /* We only do these simplifications if we are optimizing. */
6792 /* Check for things like (A || B) && (A || C). We can convert this
6793 to A || (B && C). Note that either operator can be any of the four
6794 truth and/or operations and the transformation will still be
6795 valid. Also note that we only care about order for the
6796 ANDIF and ORIF operators. If B contains side effects, this
6797 might change the truth-value of A. */
6798 if (TREE_CODE (arg0) == TREE_CODE (arg1)
6799 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
6800 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
6801 || TREE_CODE (arg0) == TRUTH_AND_EXPR
6802 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
6803 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
6805 tree a00 = TREE_OPERAND (arg0, 0);
6806 tree a01 = TREE_OPERAND (arg0, 1);
6807 tree a10 = TREE_OPERAND (arg1, 0);
6808 tree a11 = TREE_OPERAND (arg1, 1);
6809 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
6810 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
6811 && (code == TRUTH_AND_EXPR
6812 || code == TRUTH_OR_EXPR));
6814 if (operand_equal_p (a00, a10, 0))
6815 return fold (build (TREE_CODE (arg0), type, a00,
6816 fold (build (code, type, a01, a11))));
6817 else if (commutative && operand_equal_p (a00, a11, 0))
6818 return fold (build (TREE_CODE (arg0), type, a00,
6819 fold (build (code, type, a01, a10))));
6820 else if (commutative && operand_equal_p (a01, a10, 0))
6821 return fold (build (TREE_CODE (arg0), type, a01,
6822 fold (build (code, type, a00, a11))));
6824 /* This case if tricky because we must either have commutative
6825 operators or else A10 must not have side-effects. */
6827 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
6828 && operand_equal_p (a01, a11, 0))
6829 return fold (build (TREE_CODE (arg0), type,
6830 fold (build (code, type, a00, a10)),
6834 /* See if we can build a range comparison. */
6835 if (0 != (tem = fold_range_test (t)))
6838 /* Check for the possibility of merging component references. If our
6839 lhs is another similar operation, try to merge its rhs with our
6840 rhs. Then try to merge our lhs and rhs. */
6841 if (TREE_CODE (arg0) == code
6842 && 0 != (tem = fold_truthop (code, type,
6843 TREE_OPERAND (arg0, 1), arg1)))
6844 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6846 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
6851 case TRUTH_ORIF_EXPR:
6852 /* Note that the operands of this must be ints
6853 and their values must be 0 or true.
6854 ("true" is a fixed value perhaps depending on the language.) */
6855 /* If first arg is constant true, return it. */
6856 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
6857 return convert (type, arg0);
6859 /* If either arg is constant zero, drop it. */
6860 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
6861 return non_lvalue (convert (type, arg1));
6862 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
6863 /* Preserve sequence points. */
6864 && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
6865 return non_lvalue (convert (type, arg0));
6866 /* If second arg is constant true, result is true, but we must
6867 evaluate first arg. */
6868 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
6869 return omit_one_operand (type, arg1, arg0);
6870 /* Likewise for first arg, but note this only occurs here for
6872 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
6873 return omit_one_operand (type, arg0, arg1);
6876 case TRUTH_XOR_EXPR:
6877 /* If either arg is constant zero, drop it. */
6878 if (integer_zerop (arg0))
6879 return non_lvalue (convert (type, arg1));
6880 if (integer_zerop (arg1))
6881 return non_lvalue (convert (type, arg0));
6882 /* If either arg is constant true, this is a logical inversion. */
6883 if (integer_onep (arg0))
6884 return non_lvalue (convert (type, invert_truthvalue (arg1)));
6885 if (integer_onep (arg1))
6886 return non_lvalue (convert (type, invert_truthvalue (arg0)));
6895 /* If one arg is a real or integer constant, put it last. */
6896 if (tree_swap_operands_p (arg0, arg1))
6897 return fold (build (swap_tree_comparison (code), type, arg1, arg0));
6899 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
6901 tree targ0 = strip_float_extensions (arg0);
6902 tree targ1 = strip_float_extensions (arg1);
6903 tree newtype = TREE_TYPE (targ0);
6905 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
6906 newtype = TREE_TYPE (targ1);
6908 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
6909 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
6910 return fold (build (code, type, convert (newtype, targ0),
6911 convert (newtype, targ1)));
6913 /* (-a) CMP (-b) -> b CMP a */
6914 if (TREE_CODE (arg0) == NEGATE_EXPR
6915 && TREE_CODE (arg1) == NEGATE_EXPR)
6916 return fold (build (code, type, TREE_OPERAND (arg1, 0),
6917 TREE_OPERAND (arg0, 0)));
6919 if (TREE_CODE (arg1) == REAL_CST)
6921 REAL_VALUE_TYPE cst;
6922 cst = TREE_REAL_CST (arg1);
6924 /* (-a) CMP CST -> a swap(CMP) (-CST) */
6925 if (TREE_CODE (arg0) == NEGATE_EXPR)
6927 fold (build (swap_tree_comparison (code), type,
6928 TREE_OPERAND (arg0, 0),
6929 build_real (TREE_TYPE (arg1),
6930 REAL_VALUE_NEGATE (cst))));
6932 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
6933 /* a CMP (-0) -> a CMP 0 */
6934 if (REAL_VALUE_MINUS_ZERO (cst))
6935 return fold (build (code, type, arg0,
6936 build_real (TREE_TYPE (arg1), dconst0)));
6938 /* x != NaN is always true, other ops are always false. */
6939 if (REAL_VALUE_ISNAN (cst)
6940 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))))
6942 t = (code == NE_EXPR) ? integer_one_node : integer_zero_node;
6943 return omit_one_operand (type, convert (type, t), arg0);
6946 /* Fold comparisons against infinity. */
6947 if (REAL_VALUE_ISINF (cst))
6949 tem = fold_inf_compare (code, type, arg0, arg1);
6950 if (tem != NULL_TREE)
6955 /* If this is a comparison of a real constant with a PLUS_EXPR
6956 or a MINUS_EXPR of a real constant, we can convert it into a
6957 comparison with a revised real constant as long as no overflow
6958 occurs when unsafe_math_optimizations are enabled. */
6959 if (flag_unsafe_math_optimizations
6960 && TREE_CODE (arg1) == REAL_CST
6961 && (TREE_CODE (arg0) == PLUS_EXPR
6962 || TREE_CODE (arg0) == MINUS_EXPR)
6963 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
6964 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
6965 ? MINUS_EXPR : PLUS_EXPR,
6966 arg1, TREE_OPERAND (arg0, 1), 0))
6967 && ! TREE_CONSTANT_OVERFLOW (tem))
6968 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6970 /* Likewise, we can simplify a comparison of a real constant with
6971 a MINUS_EXPR whose first operand is also a real constant, i.e.
6972 (c1 - x) < c2 becomes x > c1-c2. */
6973 if (flag_unsafe_math_optimizations
6974 && TREE_CODE (arg1) == REAL_CST
6975 && TREE_CODE (arg0) == MINUS_EXPR
6976 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST
6977 && 0 != (tem = const_binop (MINUS_EXPR, TREE_OPERAND (arg0, 0),
6979 && ! TREE_CONSTANT_OVERFLOW (tem))
6980 return fold (build (swap_tree_comparison (code), type,
6981 TREE_OPERAND (arg0, 1), tem));
6983 /* Fold comparisons against built-in math functions. */
6984 if (TREE_CODE (arg1) == REAL_CST
6985 && flag_unsafe_math_optimizations
6986 && ! flag_errno_math)
6988 enum built_in_function fcode = builtin_mathfn_code (arg0);
6990 if (fcode != END_BUILTINS)
6992 tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
6993 if (tem != NULL_TREE)
6999 /* Convert foo++ == CONST into ++foo == CONST + INCR.
7000 First, see if one arg is constant; find the constant arg
7001 and the other one. */
7003 tree constop = 0, varop = NULL_TREE;
7004 int constopnum = -1;
7006 if (TREE_CONSTANT (arg1))
7007 constopnum = 1, constop = arg1, varop = arg0;
7008 if (TREE_CONSTANT (arg0))
7009 constopnum = 0, constop = arg0, varop = arg1;
7011 if (constop && TREE_CODE (varop) == POSTINCREMENT_EXPR)
7013 /* This optimization is invalid for ordered comparisons
7014 if CONST+INCR overflows or if foo+incr might overflow.
7015 This optimization is invalid for floating point due to rounding.
7016 For pointer types we assume overflow doesn't happen. */
7017 if (POINTER_TYPE_P (TREE_TYPE (varop))
7018 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
7019 && (code == EQ_EXPR || code == NE_EXPR)))
7022 = fold (build (PLUS_EXPR, TREE_TYPE (varop),
7023 constop, TREE_OPERAND (varop, 1)));
7025 /* Do not overwrite the current varop to be a preincrement,
7026 create a new node so that we won't confuse our caller who
7027 might create trees and throw them away, reusing the
7028 arguments that they passed to build. This shows up in
7029 the THEN or ELSE parts of ?: being postincrements. */
7030 varop = build (PREINCREMENT_EXPR, TREE_TYPE (varop),
7031 TREE_OPERAND (varop, 0),
7032 TREE_OPERAND (varop, 1));
7034 /* If VAROP is a reference to a bitfield, we must mask
7035 the constant by the width of the field. */
7036 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
7037 && DECL_BIT_FIELD(TREE_OPERAND
7038 (TREE_OPERAND (varop, 0), 1)))
7041 = TREE_INT_CST_LOW (DECL_SIZE
7043 (TREE_OPERAND (varop, 0), 1)));
7044 tree mask, unsigned_type;
7045 unsigned int precision;
7046 tree folded_compare;
7048 /* First check whether the comparison would come out
7049 always the same. If we don't do that we would
7050 change the meaning with the masking. */
7051 if (constopnum == 0)
7052 folded_compare = fold (build (code, type, constop,
7053 TREE_OPERAND (varop, 0)));
7055 folded_compare = fold (build (code, type,
7056 TREE_OPERAND (varop, 0),
7058 if (integer_zerop (folded_compare)
7059 || integer_onep (folded_compare))
7060 return omit_one_operand (type, folded_compare, varop);
7062 unsigned_type = (*lang_hooks.types.type_for_size)(size, 1);
7063 precision = TYPE_PRECISION (unsigned_type);
7064 mask = build_int_2 (~0, ~0);
7065 TREE_TYPE (mask) = unsigned_type;
7066 force_fit_type (mask, 0);
7067 mask = const_binop (RSHIFT_EXPR, mask,
7068 size_int (precision - size), 0);
7069 newconst = fold (build (BIT_AND_EXPR,
7070 TREE_TYPE (varop), newconst,
7071 convert (TREE_TYPE (varop),
7075 t = build (code, type,
7076 (constopnum == 0) ? newconst : varop,
7077 (constopnum == 1) ? newconst : varop);
7081 else if (constop && TREE_CODE (varop) == POSTDECREMENT_EXPR)
7083 if (POINTER_TYPE_P (TREE_TYPE (varop))
7084 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
7085 && (code == EQ_EXPR || code == NE_EXPR)))
7088 = fold (build (MINUS_EXPR, TREE_TYPE (varop),
7089 constop, TREE_OPERAND (varop, 1)));
7091 /* Do not overwrite the current varop to be a predecrement,
7092 create a new node so that we won't confuse our caller who
7093 might create trees and throw them away, reusing the
7094 arguments that they passed to build. This shows up in
7095 the THEN or ELSE parts of ?: being postdecrements. */
7096 varop = build (PREDECREMENT_EXPR, TREE_TYPE (varop),
7097 TREE_OPERAND (varop, 0),
7098 TREE_OPERAND (varop, 1));
7100 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
7101 && DECL_BIT_FIELD(TREE_OPERAND
7102 (TREE_OPERAND (varop, 0), 1)))
7105 = TREE_INT_CST_LOW (DECL_SIZE
7107 (TREE_OPERAND (varop, 0), 1)));
7108 tree mask, unsigned_type;
7109 unsigned int precision;
7110 tree folded_compare;
7112 if (constopnum == 0)
7113 folded_compare = fold (build (code, type, constop,
7114 TREE_OPERAND (varop, 0)));
7116 folded_compare = fold (build (code, type,
7117 TREE_OPERAND (varop, 0),
7119 if (integer_zerop (folded_compare)
7120 || integer_onep (folded_compare))
7121 return omit_one_operand (type, folded_compare, varop);
7123 unsigned_type = (*lang_hooks.types.type_for_size)(size, 1);
7124 precision = TYPE_PRECISION (unsigned_type);
7125 mask = build_int_2 (~0, ~0);
7126 TREE_TYPE (mask) = TREE_TYPE (varop);
7127 force_fit_type (mask, 0);
7128 mask = const_binop (RSHIFT_EXPR, mask,
7129 size_int (precision - size), 0);
7130 newconst = fold (build (BIT_AND_EXPR,
7131 TREE_TYPE (varop), newconst,
7132 convert (TREE_TYPE (varop),
7136 t = build (code, type,
7137 (constopnum == 0) ? newconst : varop,
7138 (constopnum == 1) ? newconst : varop);
7144 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
7145 This transformation affects the cases which are handled in later
7146 optimizations involving comparisons with non-negative constants. */
7147 if (TREE_CODE (arg1) == INTEGER_CST
7148 && TREE_CODE (arg0) != INTEGER_CST
7149 && tree_int_cst_sgn (arg1) > 0)
7154 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
7155 return fold (build (GT_EXPR, type, arg0, arg1));
7158 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
7159 return fold (build (LE_EXPR, type, arg0, arg1));
7166 /* Comparisons with the highest or lowest possible integer of
7167 the specified size will have known values. */
7169 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1)));
7171 if (TREE_CODE (arg1) == INTEGER_CST
7172 && ! TREE_CONSTANT_OVERFLOW (arg1)
7173 && width <= HOST_BITS_PER_WIDE_INT
7174 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
7175 || POINTER_TYPE_P (TREE_TYPE (arg1))))
7177 unsigned HOST_WIDE_INT signed_max;
7178 unsigned HOST_WIDE_INT max, min;
7180 signed_max = ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1;
7182 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
7184 max = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
7190 min = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
7193 if (TREE_INT_CST_HIGH (arg1) == 0
7194 && TREE_INT_CST_LOW (arg1) == max)
7198 return omit_one_operand (type,
7199 convert (type, integer_zero_node),
7202 return fold (build (EQ_EXPR, type, arg0, arg1));
7205 return omit_one_operand (type,
7206 convert (type, integer_one_node),
7209 return fold (build (NE_EXPR, type, arg0, arg1));
7211 /* The GE_EXPR and LT_EXPR cases above are not normally
7212 reached because of previous transformations. */
7217 else if (TREE_INT_CST_HIGH (arg1) == 0
7218 && TREE_INT_CST_LOW (arg1) == max - 1)
7222 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
7223 return fold (build (EQ_EXPR, type, arg0, arg1));
7225 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
7226 return fold (build (NE_EXPR, type, arg0, arg1));
7230 else if (TREE_INT_CST_HIGH (arg1) == (min ? -1 : 0)
7231 && TREE_INT_CST_LOW (arg1) == min)
7235 return omit_one_operand (type,
7236 convert (type, integer_zero_node),
7239 return fold (build (EQ_EXPR, type, arg0, arg1));
7242 return omit_one_operand (type,
7243 convert (type, integer_one_node),
7246 return fold (build (NE_EXPR, type, arg0, arg1));
7251 else if (TREE_INT_CST_HIGH (arg1) == (min ? -1 : 0)
7252 && TREE_INT_CST_LOW (arg1) == min + 1)
7256 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
7257 return fold (build (NE_EXPR, type, arg0, arg1));
7259 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
7260 return fold (build (EQ_EXPR, type, arg0, arg1));
7265 else if (TREE_INT_CST_HIGH (arg1) == 0
7266 && TREE_INT_CST_LOW (arg1) == signed_max
7267 && TREE_UNSIGNED (TREE_TYPE (arg1))
7268 /* signed_type does not work on pointer types. */
7269 && INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
7271 /* The following case also applies to X < signed_max+1
7272 and X >= signed_max+1 because previous transformations. */
7273 if (code == LE_EXPR || code == GT_EXPR)
7276 st0 = (*lang_hooks.types.signed_type) (TREE_TYPE (arg0));
7277 st1 = (*lang_hooks.types.signed_type) (TREE_TYPE (arg1));
7279 (build (code == LE_EXPR ? GE_EXPR: LT_EXPR,
7280 type, convert (st0, arg0),
7281 convert (st1, integer_zero_node)));
7287 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
7288 a MINUS_EXPR of a constant, we can convert it into a comparison with
7289 a revised constant as long as no overflow occurs. */
7290 if ((code == EQ_EXPR || code == NE_EXPR)
7291 && TREE_CODE (arg1) == INTEGER_CST
7292 && (TREE_CODE (arg0) == PLUS_EXPR
7293 || TREE_CODE (arg0) == MINUS_EXPR)
7294 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7295 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
7296 ? MINUS_EXPR : PLUS_EXPR,
7297 arg1, TREE_OPERAND (arg0, 1), 0))
7298 && ! TREE_CONSTANT_OVERFLOW (tem))
7299 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
7301 /* Similarly for a NEGATE_EXPR. */
7302 else if ((code == EQ_EXPR || code == NE_EXPR)
7303 && TREE_CODE (arg0) == NEGATE_EXPR
7304 && TREE_CODE (arg1) == INTEGER_CST
7305 && 0 != (tem = negate_expr (arg1))
7306 && TREE_CODE (tem) == INTEGER_CST
7307 && ! TREE_CONSTANT_OVERFLOW (tem))
7308 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
7310 /* If we have X - Y == 0, we can convert that to X == Y and similarly
7311 for !=. Don't do this for ordered comparisons due to overflow. */
7312 else if ((code == NE_EXPR || code == EQ_EXPR)
7313 && integer_zerop (arg1) && TREE_CODE (arg0) == MINUS_EXPR)
7314 return fold (build (code, type,
7315 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1)));
7317 /* If we are widening one operand of an integer comparison,
7318 see if the other operand is similarly being widened. Perhaps we
7319 can do the comparison in the narrower type. */
7320 else if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
7321 && TREE_CODE (arg0) == NOP_EXPR
7322 && (tem = get_unwidened (arg0, NULL_TREE)) != arg0
7323 && (t1 = get_unwidened (arg1, TREE_TYPE (tem))) != 0
7324 && (TREE_TYPE (t1) == TREE_TYPE (tem)
7325 || (TREE_CODE (t1) == INTEGER_CST
7326 && int_fits_type_p (t1, TREE_TYPE (tem)))))
7327 return fold (build (code, type, tem, convert (TREE_TYPE (tem), t1)));
7329 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
7330 constant, we can simplify it. */
7331 else if (TREE_CODE (arg1) == INTEGER_CST
7332 && (TREE_CODE (arg0) == MIN_EXPR
7333 || TREE_CODE (arg0) == MAX_EXPR)
7334 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
7335 return optimize_minmax_comparison (t);
7337 /* If we are comparing an ABS_EXPR with a constant, we can
7338 convert all the cases into explicit comparisons, but they may
7339 well not be faster than doing the ABS and one comparison.
7340 But ABS (X) <= C is a range comparison, which becomes a subtraction
7341 and a comparison, and is probably faster. */
7342 else if (code == LE_EXPR && TREE_CODE (arg1) == INTEGER_CST
7343 && TREE_CODE (arg0) == ABS_EXPR
7344 && ! TREE_SIDE_EFFECTS (arg0)
7345 && (0 != (tem = negate_expr (arg1)))
7346 && TREE_CODE (tem) == INTEGER_CST
7347 && ! TREE_CONSTANT_OVERFLOW (tem))
7348 return fold (build (TRUTH_ANDIF_EXPR, type,
7349 build (GE_EXPR, type, TREE_OPERAND (arg0, 0), tem),
7350 build (LE_EXPR, type,
7351 TREE_OPERAND (arg0, 0), arg1)));
7353 /* If this is an EQ or NE comparison with zero and ARG0 is
7354 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
7355 two operations, but the latter can be done in one less insn
7356 on machines that have only two-operand insns or on which a
7357 constant cannot be the first operand. */
7358 if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR)
7359 && TREE_CODE (arg0) == BIT_AND_EXPR)
7361 if (TREE_CODE (TREE_OPERAND (arg0, 0)) == LSHIFT_EXPR
7362 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 0), 0)))
7364 fold (build (code, type,
7365 build (BIT_AND_EXPR, TREE_TYPE (arg0),
7367 TREE_TYPE (TREE_OPERAND (arg0, 0)),
7368 TREE_OPERAND (arg0, 1),
7369 TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)),
7370 convert (TREE_TYPE (arg0),
7373 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
7374 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
7376 fold (build (code, type,
7377 build (BIT_AND_EXPR, TREE_TYPE (arg0),
7379 TREE_TYPE (TREE_OPERAND (arg0, 1)),
7380 TREE_OPERAND (arg0, 0),
7381 TREE_OPERAND (TREE_OPERAND (arg0, 1), 1)),
7382 convert (TREE_TYPE (arg0),
7387 /* If this is an NE or EQ comparison of zero against the result of a
7388 signed MOD operation whose second operand is a power of 2, make
7389 the MOD operation unsigned since it is simpler and equivalent. */
7390 if ((code == NE_EXPR || code == EQ_EXPR)
7391 && integer_zerop (arg1)
7392 && ! TREE_UNSIGNED (TREE_TYPE (arg0))
7393 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
7394 || TREE_CODE (arg0) == CEIL_MOD_EXPR
7395 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
7396 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
7397 && integer_pow2p (TREE_OPERAND (arg0, 1)))
7399 tree newtype = (*lang_hooks.types.unsigned_type) (TREE_TYPE (arg0));
7400 tree newmod = build (TREE_CODE (arg0), newtype,
7401 convert (newtype, TREE_OPERAND (arg0, 0)),
7402 convert (newtype, TREE_OPERAND (arg0, 1)));
7404 return build (code, type, newmod, convert (newtype, arg1));
7407 /* If this is an NE comparison of zero with an AND of one, remove the
7408 comparison since the AND will give the correct value. */
7409 if (code == NE_EXPR && integer_zerop (arg1)
7410 && TREE_CODE (arg0) == BIT_AND_EXPR
7411 && integer_onep (TREE_OPERAND (arg0, 1)))
7412 return convert (type, arg0);
7414 /* If we have (A & C) == C where C is a power of 2, convert this into
7415 (A & C) != 0. Similarly for NE_EXPR. */
7416 if ((code == EQ_EXPR || code == NE_EXPR)
7417 && TREE_CODE (arg0) == BIT_AND_EXPR
7418 && integer_pow2p (TREE_OPERAND (arg0, 1))
7419 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
7420 return fold (build (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
7421 arg0, integer_zero_node));
7423 /* If we have (A & C) != 0 or (A & C) == 0 and C is a power of
7424 2, then fold the expression into shifts and logical operations. */
7425 tem = fold_single_bit_test (code, arg0, arg1, type);
7429 /* If we have (A & C) == D where D & ~C != 0, convert this into 0.
7430 Similarly for NE_EXPR. */
7431 if ((code == EQ_EXPR || code == NE_EXPR)
7432 && TREE_CODE (arg0) == BIT_AND_EXPR
7433 && TREE_CODE (arg1) == INTEGER_CST
7434 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
7437 = fold (build (BIT_AND_EXPR, TREE_TYPE (arg0),
7438 arg1, build1 (BIT_NOT_EXPR,
7439 TREE_TYPE (TREE_OPERAND (arg0, 1)),
7440 TREE_OPERAND (arg0, 1))));
7441 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
7442 if (integer_nonzerop (dandnotc))
7443 return omit_one_operand (type, rslt, arg0);
7446 /* If we have (A | C) == D where C & ~D != 0, convert this into 0.
7447 Similarly for NE_EXPR. */
7448 if ((code == EQ_EXPR || code == NE_EXPR)
7449 && TREE_CODE (arg0) == BIT_IOR_EXPR
7450 && TREE_CODE (arg1) == INTEGER_CST
7451 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
7454 = fold (build (BIT_AND_EXPR, TREE_TYPE (arg0),
7455 TREE_OPERAND (arg0, 1),
7456 build1 (BIT_NOT_EXPR, TREE_TYPE (arg1), arg1)));
7457 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
7458 if (integer_nonzerop (candnotd))
7459 return omit_one_operand (type, rslt, arg0);
7462 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
7463 and similarly for >= into !=. */
7464 if ((code == LT_EXPR || code == GE_EXPR)
7465 && TREE_UNSIGNED (TREE_TYPE (arg0))
7466 && TREE_CODE (arg1) == LSHIFT_EXPR
7467 && integer_onep (TREE_OPERAND (arg1, 0)))
7468 return build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
7469 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
7470 TREE_OPERAND (arg1, 1)),
7471 convert (TREE_TYPE (arg0), integer_zero_node));
7473 else if ((code == LT_EXPR || code == GE_EXPR)
7474 && TREE_UNSIGNED (TREE_TYPE (arg0))
7475 && (TREE_CODE (arg1) == NOP_EXPR
7476 || TREE_CODE (arg1) == CONVERT_EXPR)
7477 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
7478 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
7480 build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
7481 convert (TREE_TYPE (arg0),
7482 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
7483 TREE_OPERAND (TREE_OPERAND (arg1, 0), 1))),
7484 convert (TREE_TYPE (arg0), integer_zero_node));
7486 /* Simplify comparison of something with itself. (For IEEE
7487 floating-point, we can only do some of these simplifications.) */
7488 if (operand_equal_p (arg0, arg1, 0))
7493 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
7494 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
7495 return constant_boolean_node (1, type);
7500 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
7501 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
7502 return constant_boolean_node (1, type);
7503 return fold (build (EQ_EXPR, type, arg0, arg1));
7506 /* For NE, we can only do this simplification if integer
7507 or we don't honor IEEE floating point NaNs. */
7508 if (FLOAT_TYPE_P (TREE_TYPE (arg0))
7509 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
7511 /* ... fall through ... */
7514 return constant_boolean_node (0, type);
7520 /* If we are comparing an expression that just has comparisons
7521 of two integer values, arithmetic expressions of those comparisons,
7522 and constants, we can simplify it. There are only three cases
7523 to check: the two values can either be equal, the first can be
7524 greater, or the second can be greater. Fold the expression for
7525 those three values. Since each value must be 0 or 1, we have
7526 eight possibilities, each of which corresponds to the constant 0
7527 or 1 or one of the six possible comparisons.
7529 This handles common cases like (a > b) == 0 but also handles
7530 expressions like ((x > y) - (y > x)) > 0, which supposedly
7531 occur in macroized code. */
7533 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
7535 tree cval1 = 0, cval2 = 0;
7538 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
7539 /* Don't handle degenerate cases here; they should already
7540 have been handled anyway. */
7541 && cval1 != 0 && cval2 != 0
7542 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
7543 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
7544 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
7545 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
7546 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
7547 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
7548 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
7550 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
7551 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
7553 /* We can't just pass T to eval_subst in case cval1 or cval2
7554 was the same as ARG1. */
7557 = fold (build (code, type,
7558 eval_subst (arg0, cval1, maxval, cval2, minval),
7561 = fold (build (code, type,
7562 eval_subst (arg0, cval1, maxval, cval2, maxval),
7565 = fold (build (code, type,
7566 eval_subst (arg0, cval1, minval, cval2, maxval),
7569 /* All three of these results should be 0 or 1. Confirm they
7570 are. Then use those values to select the proper code
7573 if ((integer_zerop (high_result)
7574 || integer_onep (high_result))
7575 && (integer_zerop (equal_result)
7576 || integer_onep (equal_result))
7577 && (integer_zerop (low_result)
7578 || integer_onep (low_result)))
7580 /* Make a 3-bit mask with the high-order bit being the
7581 value for `>', the next for '=', and the low for '<'. */
7582 switch ((integer_onep (high_result) * 4)
7583 + (integer_onep (equal_result) * 2)
7584 + integer_onep (low_result))
7588 return omit_one_operand (type, integer_zero_node, arg0);
7609 return omit_one_operand (type, integer_one_node, arg0);
7612 t = build (code, type, cval1, cval2);
7614 return save_expr (t);
7621 /* If this is a comparison of a field, we may be able to simplify it. */
7622 if (((TREE_CODE (arg0) == COMPONENT_REF
7623 && (*lang_hooks.can_use_bit_fields_p) ())
7624 || TREE_CODE (arg0) == BIT_FIELD_REF)
7625 && (code == EQ_EXPR || code == NE_EXPR)
7626 /* Handle the constant case even without -O
7627 to make sure the warnings are given. */
7628 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
7630 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
7634 /* If this is a comparison of complex values and either or both sides
7635 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
7636 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
7637 This may prevent needless evaluations. */
7638 if ((code == EQ_EXPR || code == NE_EXPR)
7639 && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
7640 && (TREE_CODE (arg0) == COMPLEX_EXPR
7641 || TREE_CODE (arg1) == COMPLEX_EXPR
7642 || TREE_CODE (arg0) == COMPLEX_CST
7643 || TREE_CODE (arg1) == COMPLEX_CST))
7645 tree subtype = TREE_TYPE (TREE_TYPE (arg0));
7646 tree real0, imag0, real1, imag1;
7648 arg0 = save_expr (arg0);
7649 arg1 = save_expr (arg1);
7650 real0 = fold (build1 (REALPART_EXPR, subtype, arg0));
7651 imag0 = fold (build1 (IMAGPART_EXPR, subtype, arg0));
7652 real1 = fold (build1 (REALPART_EXPR, subtype, arg1));
7653 imag1 = fold (build1 (IMAGPART_EXPR, subtype, arg1));
7655 return fold (build ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR
7658 fold (build (code, type, real0, real1)),
7659 fold (build (code, type, imag0, imag1))));
7662 /* Optimize comparisons of strlen vs zero to a compare of the
7663 first character of the string vs zero. To wit,
7664 strlen(ptr) == 0 => *ptr == 0
7665 strlen(ptr) != 0 => *ptr != 0
7666 Other cases should reduce to one of these two (or a constant)
7667 due to the return value of strlen being unsigned. */
7668 if ((code == EQ_EXPR || code == NE_EXPR)
7669 && integer_zerop (arg1)
7670 && TREE_CODE (arg0) == CALL_EXPR)
7672 tree fndecl = get_callee_fndecl (arg0);
7676 && DECL_BUILT_IN (fndecl)
7677 && DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_MD
7678 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
7679 && (arglist = TREE_OPERAND (arg0, 1))
7680 && TREE_CODE (TREE_TYPE (TREE_VALUE (arglist))) == POINTER_TYPE
7681 && ! TREE_CHAIN (arglist))
7682 return fold (build (code, type,
7683 build1 (INDIRECT_REF, char_type_node,
7684 TREE_VALUE(arglist)),
7685 integer_zero_node));
7688 /* From here on, the only cases we handle are when the result is
7689 known to be a constant.
7691 To compute GT, swap the arguments and do LT.
7692 To compute GE, do LT and invert the result.
7693 To compute LE, swap the arguments, do LT and invert the result.
7694 To compute NE, do EQ and invert the result.
7696 Therefore, the code below must handle only EQ and LT. */
7698 if (code == LE_EXPR || code == GT_EXPR)
7700 tem = arg0, arg0 = arg1, arg1 = tem;
7701 code = swap_tree_comparison (code);
7704 /* Note that it is safe to invert for real values here because we
7705 will check below in the one case that it matters. */
7709 if (code == NE_EXPR || code == GE_EXPR)
7712 code = invert_tree_comparison (code);
7715 /* Compute a result for LT or EQ if args permit;
7716 otherwise return T. */
7717 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
7719 if (code == EQ_EXPR)
7720 t1 = build_int_2 (tree_int_cst_equal (arg0, arg1), 0);
7722 t1 = build_int_2 ((TREE_UNSIGNED (TREE_TYPE (arg0))
7723 ? INT_CST_LT_UNSIGNED (arg0, arg1)
7724 : INT_CST_LT (arg0, arg1)),
7728 #if 0 /* This is no longer useful, but breaks some real code. */
7729 /* Assume a nonexplicit constant cannot equal an explicit one,
7730 since such code would be undefined anyway.
7731 Exception: on sysvr4, using #pragma weak,
7732 a label can come out as 0. */
7733 else if (TREE_CODE (arg1) == INTEGER_CST
7734 && !integer_zerop (arg1)
7735 && TREE_CONSTANT (arg0)
7736 && TREE_CODE (arg0) == ADDR_EXPR
7738 t1 = build_int_2 (0, 0);
7740 /* Two real constants can be compared explicitly. */
7741 else if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
7743 /* If either operand is a NaN, the result is false with two
7744 exceptions: First, an NE_EXPR is true on NaNs, but that case
7745 is already handled correctly since we will be inverting the
7746 result for NE_EXPR. Second, if we had inverted a LE_EXPR
7747 or a GE_EXPR into a LT_EXPR, we must return true so that it
7748 will be inverted into false. */
7750 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
7751 || REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
7752 t1 = build_int_2 (invert && code == LT_EXPR, 0);
7754 else if (code == EQ_EXPR)
7755 t1 = build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (arg0),
7756 TREE_REAL_CST (arg1)),
7759 t1 = build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (arg0),
7760 TREE_REAL_CST (arg1)),
7764 if (t1 == NULL_TREE)
7768 TREE_INT_CST_LOW (t1) ^= 1;
7770 TREE_TYPE (t1) = type;
7771 if (TREE_CODE (type) == BOOLEAN_TYPE)
7772 return (*lang_hooks.truthvalue_conversion) (t1);
7776 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
7777 so all simple results must be passed through pedantic_non_lvalue. */
7778 if (TREE_CODE (arg0) == INTEGER_CST)
7779 return pedantic_non_lvalue
7780 (TREE_OPERAND (t, (integer_zerop (arg0) ? 2 : 1)));
7781 else if (operand_equal_p (arg1, TREE_OPERAND (expr, 2), 0))
7782 return pedantic_omit_one_operand (type, arg1, arg0);
7784 /* If we have A op B ? A : C, we may be able to convert this to a
7785 simpler expression, depending on the operation and the values
7786 of B and C. Signed zeros prevent all of these transformations,
7787 for reasons given above each one. */
7789 if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
7790 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
7791 arg1, TREE_OPERAND (arg0, 1))
7792 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
7794 tree arg2 = TREE_OPERAND (t, 2);
7795 enum tree_code comp_code = TREE_CODE (arg0);
7799 /* If we have A op 0 ? A : -A, consider applying the following
7802 A == 0? A : -A same as -A
7803 A != 0? A : -A same as A
7804 A >= 0? A : -A same as abs (A)
7805 A > 0? A : -A same as abs (A)
7806 A <= 0? A : -A same as -abs (A)
7807 A < 0? A : -A same as -abs (A)
7809 None of these transformations work for modes with signed
7810 zeros. If A is +/-0, the first two transformations will
7811 change the sign of the result (from +0 to -0, or vice
7812 versa). The last four will fix the sign of the result,
7813 even though the original expressions could be positive or
7814 negative, depending on the sign of A.
7816 Note that all these transformations are correct if A is
7817 NaN, since the two alternatives (A and -A) are also NaNs. */
7818 if ((FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 1)))
7819 ? real_zerop (TREE_OPERAND (arg0, 1))
7820 : integer_zerop (TREE_OPERAND (arg0, 1)))
7821 && TREE_CODE (arg2) == NEGATE_EXPR
7822 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
7830 (convert (TREE_TYPE (TREE_OPERAND (t, 1)),
7833 return pedantic_non_lvalue (convert (type, arg1));
7836 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
7837 arg1 = convert ((*lang_hooks.types.signed_type)
7838 (TREE_TYPE (arg1)), arg1);
7839 return pedantic_non_lvalue
7840 (convert (type, fold (build1 (ABS_EXPR,
7841 TREE_TYPE (arg1), arg1))));
7844 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
7845 arg1 = convert ((lang_hooks.types.signed_type)
7846 (TREE_TYPE (arg1)), arg1);
7847 return pedantic_non_lvalue
7848 (negate_expr (convert (type,
7849 fold (build1 (ABS_EXPR,
7856 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
7857 A == 0 ? A : 0 is always 0 unless A is -0. Note that
7858 both transformations are correct when A is NaN: A != 0
7859 is then true, and A == 0 is false. */
7861 if (integer_zerop (TREE_OPERAND (arg0, 1)) && integer_zerop (arg2))
7863 if (comp_code == NE_EXPR)
7864 return pedantic_non_lvalue (convert (type, arg1));
7865 else if (comp_code == EQ_EXPR)
7866 return pedantic_non_lvalue (convert (type, integer_zero_node));
7869 /* Try some transformations of A op B ? A : B.
7871 A == B? A : B same as B
7872 A != B? A : B same as A
7873 A >= B? A : B same as max (A, B)
7874 A > B? A : B same as max (B, A)
7875 A <= B? A : B same as min (A, B)
7876 A < B? A : B same as min (B, A)
7878 As above, these transformations don't work in the presence
7879 of signed zeros. For example, if A and B are zeros of
7880 opposite sign, the first two transformations will change
7881 the sign of the result. In the last four, the original
7882 expressions give different results for (A=+0, B=-0) and
7883 (A=-0, B=+0), but the transformed expressions do not.
7885 The first two transformations are correct if either A or B
7886 is a NaN. In the first transformation, the condition will
7887 be false, and B will indeed be chosen. In the case of the
7888 second transformation, the condition A != B will be true,
7889 and A will be chosen.
7891 The conversions to max() and min() are not correct if B is
7892 a number and A is not. The conditions in the original
7893 expressions will be false, so all four give B. The min()
7894 and max() versions would give a NaN instead. */
7895 if (operand_equal_for_comparison_p (TREE_OPERAND (arg0, 1),
7896 arg2, TREE_OPERAND (arg0, 0)))
7898 tree comp_op0 = TREE_OPERAND (arg0, 0);
7899 tree comp_op1 = TREE_OPERAND (arg0, 1);
7900 tree comp_type = TREE_TYPE (comp_op0);
7902 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
7903 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
7913 return pedantic_non_lvalue (convert (type, arg2));
7915 return pedantic_non_lvalue (convert (type, arg1));
7918 /* In C++ a ?: expression can be an lvalue, so put the
7919 operand which will be used if they are equal first
7920 so that we can convert this back to the
7921 corresponding COND_EXPR. */
7922 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
7923 return pedantic_non_lvalue
7924 (convert (type, fold (build (MIN_EXPR, comp_type,
7925 (comp_code == LE_EXPR
7926 ? comp_op0 : comp_op1),
7927 (comp_code == LE_EXPR
7928 ? comp_op1 : comp_op0)))));
7932 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
7933 return pedantic_non_lvalue
7934 (convert (type, fold (build (MAX_EXPR, comp_type,
7935 (comp_code == GE_EXPR
7936 ? comp_op0 : comp_op1),
7937 (comp_code == GE_EXPR
7938 ? comp_op1 : comp_op0)))));
7945 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
7946 we might still be able to simplify this. For example,
7947 if C1 is one less or one more than C2, this might have started
7948 out as a MIN or MAX and been transformed by this function.
7949 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
7951 if (INTEGRAL_TYPE_P (type)
7952 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7953 && TREE_CODE (arg2) == INTEGER_CST)
7957 /* We can replace A with C1 in this case. */
7958 arg1 = convert (type, TREE_OPERAND (arg0, 1));
7959 return fold (build (code, type, TREE_OPERAND (t, 0), arg1,
7960 TREE_OPERAND (t, 2)));
7963 /* If C1 is C2 + 1, this is min(A, C2). */
7964 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
7965 && operand_equal_p (TREE_OPERAND (arg0, 1),
7966 const_binop (PLUS_EXPR, arg2,
7967 integer_one_node, 0), 1))
7968 return pedantic_non_lvalue
7969 (fold (build (MIN_EXPR, type, arg1, arg2)));
7973 /* If C1 is C2 - 1, this is min(A, C2). */
7974 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
7975 && operand_equal_p (TREE_OPERAND (arg0, 1),
7976 const_binop (MINUS_EXPR, arg2,
7977 integer_one_node, 0), 1))
7978 return pedantic_non_lvalue
7979 (fold (build (MIN_EXPR, type, arg1, arg2)));
7983 /* If C1 is C2 - 1, this is max(A, C2). */
7984 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
7985 && operand_equal_p (TREE_OPERAND (arg0, 1),
7986 const_binop (MINUS_EXPR, arg2,
7987 integer_one_node, 0), 1))
7988 return pedantic_non_lvalue
7989 (fold (build (MAX_EXPR, type, arg1, arg2)));
7993 /* If C1 is C2 + 1, this is max(A, C2). */
7994 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
7995 && operand_equal_p (TREE_OPERAND (arg0, 1),
7996 const_binop (PLUS_EXPR, arg2,
7997 integer_one_node, 0), 1))
7998 return pedantic_non_lvalue
7999 (fold (build (MAX_EXPR, type, arg1, arg2)));
8008 /* If the second operand is simpler than the third, swap them
8009 since that produces better jump optimization results. */
8010 if (tree_swap_operands_p (TREE_OPERAND (t, 1), TREE_OPERAND (t, 2)))
8012 /* See if this can be inverted. If it can't, possibly because
8013 it was a floating-point inequality comparison, don't do
8015 tem = invert_truthvalue (arg0);
8017 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
8018 return fold (build (code, type, tem,
8019 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1)));
8022 /* Convert A ? 1 : 0 to simply A. */
8023 if (integer_onep (TREE_OPERAND (t, 1))
8024 && integer_zerop (TREE_OPERAND (t, 2))
8025 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
8026 call to fold will try to move the conversion inside
8027 a COND, which will recurse. In that case, the COND_EXPR
8028 is probably the best choice, so leave it alone. */
8029 && type == TREE_TYPE (arg0))
8030 return pedantic_non_lvalue (arg0);
8032 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
8033 over COND_EXPR in cases such as floating point comparisons. */
8034 if (integer_zerop (TREE_OPERAND (t, 1))
8035 && integer_onep (TREE_OPERAND (t, 2))
8036 && truth_value_p (TREE_CODE (arg0)))
8037 return pedantic_non_lvalue (convert (type,
8038 invert_truthvalue (arg0)));
8040 /* Look for expressions of the form A & 2 ? 2 : 0. The result of this
8041 operation is simply A & 2. */
8043 if (integer_zerop (TREE_OPERAND (t, 2))
8044 && TREE_CODE (arg0) == NE_EXPR
8045 && integer_zerop (TREE_OPERAND (arg0, 1))
8046 && integer_pow2p (arg1)
8047 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
8048 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
8050 return pedantic_non_lvalue (convert (type, TREE_OPERAND (arg0, 0)));
8052 /* Convert A ? B : 0 into A && B if A and B are truth values. */
8053 if (integer_zerop (TREE_OPERAND (t, 2))
8054 && truth_value_p (TREE_CODE (arg0))
8055 && truth_value_p (TREE_CODE (arg1)))
8056 return pedantic_non_lvalue (fold (build (TRUTH_ANDIF_EXPR, type,
8059 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
8060 if (integer_onep (TREE_OPERAND (t, 2))
8061 && truth_value_p (TREE_CODE (arg0))
8062 && truth_value_p (TREE_CODE (arg1)))
8064 /* Only perform transformation if ARG0 is easily inverted. */
8065 tem = invert_truthvalue (arg0);
8066 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
8067 return pedantic_non_lvalue (fold (build (TRUTH_ORIF_EXPR, type,
8074 /* When pedantic, a compound expression can be neither an lvalue
8075 nor an integer constant expression. */
8076 if (TREE_SIDE_EFFECTS (arg0) || pedantic)
8078 /* Don't let (0, 0) be null pointer constant. */
8079 if (integer_zerop (arg1))
8080 return build1 (NOP_EXPR, type, arg1);
8081 return convert (type, arg1);
8085 return build_complex (type, arg0, arg1);
8089 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8091 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
8092 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
8093 TREE_OPERAND (arg0, 1));
8094 else if (TREE_CODE (arg0) == COMPLEX_CST)
8095 return TREE_REALPART (arg0);
8096 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8097 return fold (build (TREE_CODE (arg0), type,
8098 fold (build1 (REALPART_EXPR, type,
8099 TREE_OPERAND (arg0, 0))),
8100 fold (build1 (REALPART_EXPR,
8101 type, TREE_OPERAND (arg0, 1)))));
8105 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8106 return convert (type, integer_zero_node);
8107 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
8108 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
8109 TREE_OPERAND (arg0, 0));
8110 else if (TREE_CODE (arg0) == COMPLEX_CST)
8111 return TREE_IMAGPART (arg0);
8112 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8113 return fold (build (TREE_CODE (arg0), type,
8114 fold (build1 (IMAGPART_EXPR, type,
8115 TREE_OPERAND (arg0, 0))),
8116 fold (build1 (IMAGPART_EXPR, type,
8117 TREE_OPERAND (arg0, 1)))));
8120 /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
8122 case CLEANUP_POINT_EXPR:
8123 if (! has_cleanups (arg0))
8124 return TREE_OPERAND (t, 0);
8127 enum tree_code code0 = TREE_CODE (arg0);
8128 int kind0 = TREE_CODE_CLASS (code0);
8129 tree arg00 = TREE_OPERAND (arg0, 0);
8132 if (kind0 == '1' || code0 == TRUTH_NOT_EXPR)
8133 return fold (build1 (code0, type,
8134 fold (build1 (CLEANUP_POINT_EXPR,
8135 TREE_TYPE (arg00), arg00))));
8137 if (kind0 == '<' || kind0 == '2'
8138 || code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR
8139 || code0 == TRUTH_AND_EXPR || code0 == TRUTH_OR_EXPR
8140 || code0 == TRUTH_XOR_EXPR)
8142 arg01 = TREE_OPERAND (arg0, 1);
8144 if (TREE_CONSTANT (arg00)
8145 || ((code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR)
8146 && ! has_cleanups (arg00)))
8147 return fold (build (code0, type, arg00,
8148 fold (build1 (CLEANUP_POINT_EXPR,
8149 TREE_TYPE (arg01), arg01))));
8151 if (TREE_CONSTANT (arg01))
8152 return fold (build (code0, type,
8153 fold (build1 (CLEANUP_POINT_EXPR,
8154 TREE_TYPE (arg00), arg00)),
8162 /* Check for a built-in function. */
8163 if (TREE_CODE (TREE_OPERAND (expr, 0)) == ADDR_EXPR
8164 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (expr, 0), 0))
8166 && DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (expr, 0), 0)))
8168 tree tmp = fold_builtin (expr);
8176 } /* switch (code) */
8179 #ifdef ENABLE_FOLD_CHECKING
8182 static void fold_checksum_tree (tree, struct md5_ctx *, htab_t);
8183 static void fold_check_failed (tree, tree);
8184 void print_fold_checksum (tree);
8186 /* When --enable-checking=fold, compute a digest of expr before
8187 and after actual fold call to see if fold did not accidentally
8188 change original expr. */
8195 unsigned char checksum_before[16], checksum_after[16];
8198 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
8199 md5_init_ctx (&ctx);
8200 fold_checksum_tree (expr, &ctx, ht);
8201 md5_finish_ctx (&ctx, checksum_before);
8204 ret = fold_1 (expr);
8206 md5_init_ctx (&ctx);
8207 fold_checksum_tree (expr, &ctx, ht);
8208 md5_finish_ctx (&ctx, checksum_after);
8211 if (memcmp (checksum_before, checksum_after, 16))
8212 fold_check_failed (expr, ret);
8218 print_fold_checksum (tree expr)
8221 unsigned char checksum[16], cnt;
8224 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
8225 md5_init_ctx (&ctx);
8226 fold_checksum_tree (expr, &ctx, ht);
8227 md5_finish_ctx (&ctx, checksum);
8229 for (cnt = 0; cnt < 16; ++cnt)
8230 fprintf (stderr, "%02x", checksum[cnt]);
8231 putc ('\n', stderr);
8235 fold_check_failed (tree expr ATTRIBUTE_UNUSED, tree ret ATTRIBUTE_UNUSED)
8237 internal_error ("fold check: original tree changed by fold");
8241 fold_checksum_tree (tree expr, struct md5_ctx *ctx, htab_t ht)
8244 enum tree_code code;
8245 char buf[sizeof (struct tree_decl)];
8248 if (sizeof (struct tree_exp) + 5 * sizeof (tree)
8249 > sizeof (struct tree_decl)
8250 || sizeof (struct tree_type) > sizeof (struct tree_decl))
8254 slot = htab_find_slot (ht, expr, INSERT);
8258 code = TREE_CODE (expr);
8259 if (code == SAVE_EXPR && SAVE_EXPR_NOPLACEHOLDER (expr))
8261 /* Allow SAVE_EXPR_NOPLACEHOLDER flag to be modified. */
8262 memcpy (buf, expr, tree_size (expr));
8264 SAVE_EXPR_NOPLACEHOLDER (expr) = 0;
8266 else if (TREE_CODE_CLASS (code) == 'd' && DECL_ASSEMBLER_NAME_SET_P (expr))
8268 /* Allow DECL_ASSEMBLER_NAME to be modified. */
8269 memcpy (buf, expr, tree_size (expr));
8271 SET_DECL_ASSEMBLER_NAME (expr, NULL);
8273 else if (TREE_CODE_CLASS (code) == 't'
8274 && (TYPE_POINTER_TO (expr) || TYPE_REFERENCE_TO (expr)))
8276 /* Allow TYPE_POINTER_TO and TYPE_REFERENCE_TO to be modified. */
8277 memcpy (buf, expr, tree_size (expr));
8279 TYPE_POINTER_TO (expr) = NULL;
8280 TYPE_REFERENCE_TO (expr) = NULL;
8282 md5_process_bytes (expr, tree_size (expr), ctx);
8283 fold_checksum_tree (TREE_TYPE (expr), ctx, ht);
8284 if (TREE_CODE_CLASS (code) != 't' && TREE_CODE_CLASS (code) != 'd')
8285 fold_checksum_tree (TREE_CHAIN (expr), ctx, ht);
8286 len = TREE_CODE_LENGTH (code);
8287 switch (TREE_CODE_CLASS (code))
8293 md5_process_bytes (TREE_STRING_POINTER (expr),
8294 TREE_STRING_LENGTH (expr), ctx);
8297 fold_checksum_tree (TREE_REALPART (expr), ctx, ht);
8298 fold_checksum_tree (TREE_IMAGPART (expr), ctx, ht);
8301 fold_checksum_tree (TREE_VECTOR_CST_ELTS (expr), ctx, ht);
8311 fold_checksum_tree (TREE_PURPOSE (expr), ctx, ht);
8312 fold_checksum_tree (TREE_VALUE (expr), ctx, ht);
8315 for (i = 0; i < TREE_VEC_LENGTH (expr); ++i)
8316 fold_checksum_tree (TREE_VEC_ELT (expr, i), ctx, ht);
8325 case SAVE_EXPR: len = 2; break;
8326 case GOTO_SUBROUTINE_EXPR: len = 0; break;
8327 case RTL_EXPR: len = 0; break;
8328 case WITH_CLEANUP_EXPR: len = 2; break;
8337 for (i = 0; i < len; ++i)
8338 fold_checksum_tree (TREE_OPERAND (expr, i), ctx, ht);
8341 fold_checksum_tree (DECL_SIZE (expr), ctx, ht);
8342 fold_checksum_tree (DECL_SIZE_UNIT (expr), ctx, ht);
8343 fold_checksum_tree (DECL_NAME (expr), ctx, ht);
8344 fold_checksum_tree (DECL_CONTEXT (expr), ctx, ht);
8345 fold_checksum_tree (DECL_ARGUMENTS (expr), ctx, ht);
8346 fold_checksum_tree (DECL_RESULT_FLD (expr), ctx, ht);
8347 fold_checksum_tree (DECL_INITIAL (expr), ctx, ht);
8348 fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr), ctx, ht);
8349 fold_checksum_tree (DECL_SECTION_NAME (expr), ctx, ht);
8350 fold_checksum_tree (DECL_ATTRIBUTES (expr), ctx, ht);
8351 fold_checksum_tree (DECL_VINDEX (expr), ctx, ht);
8354 fold_checksum_tree (TYPE_VALUES (expr), ctx, ht);
8355 fold_checksum_tree (TYPE_SIZE (expr), ctx, ht);
8356 fold_checksum_tree (TYPE_SIZE_UNIT (expr), ctx, ht);
8357 fold_checksum_tree (TYPE_ATTRIBUTES (expr), ctx, ht);
8358 fold_checksum_tree (TYPE_NAME (expr), ctx, ht);
8359 fold_checksum_tree (TYPE_MIN_VALUE (expr), ctx, ht);
8360 fold_checksum_tree (TYPE_MAX_VALUE (expr), ctx, ht);
8361 fold_checksum_tree (TYPE_MAIN_VARIANT (expr), ctx, ht);
8362 fold_checksum_tree (TYPE_BINFO (expr), ctx, ht);
8363 fold_checksum_tree (TYPE_CONTEXT (expr), ctx, ht);
8372 /* Perform constant folding and related simplification of initializer
8373 expression EXPR. This behaves identically to "fold" but ignores
8374 potential run-time traps and exceptions that fold must preserve. */
8377 fold_initializer (tree expr)
8379 int saved_signaling_nans = flag_signaling_nans;
8380 int saved_trapping_math = flag_trapping_math;
8381 int saved_trapv = flag_trapv;
8384 flag_signaling_nans = 0;
8385 flag_trapping_math = 0;
8388 result = fold (expr);
8390 flag_signaling_nans = saved_signaling_nans;
8391 flag_trapping_math = saved_trapping_math;
8392 flag_trapv = saved_trapv;
8397 /* Determine if first argument is a multiple of second argument. Return 0 if
8398 it is not, or we cannot easily determined it to be.
8400 An example of the sort of thing we care about (at this point; this routine
8401 could surely be made more general, and expanded to do what the *_DIV_EXPR's
8402 fold cases do now) is discovering that
8404 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
8410 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
8412 This code also handles discovering that
8414 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
8416 is a multiple of 8 so we don't have to worry about dealing with a
8419 Note that we *look* inside a SAVE_EXPR only to determine how it was
8420 calculated; it is not safe for fold to do much of anything else with the
8421 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
8422 at run time. For example, the latter example above *cannot* be implemented
8423 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
8424 evaluation time of the original SAVE_EXPR is not necessarily the same at
8425 the time the new expression is evaluated. The only optimization of this
8426 sort that would be valid is changing
8428 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
8432 SAVE_EXPR (I) * SAVE_EXPR (J)
8434 (where the same SAVE_EXPR (J) is used in the original and the
8435 transformed version). */
8438 multiple_of_p (tree type, tree top, tree bottom)
8440 if (operand_equal_p (top, bottom, 0))
8443 if (TREE_CODE (type) != INTEGER_TYPE)
8446 switch (TREE_CODE (top))
8449 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
8450 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
8454 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
8455 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
8458 if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
8462 op1 = TREE_OPERAND (top, 1);
8463 /* const_binop may not detect overflow correctly,
8464 so check for it explicitly here. */
8465 if (TYPE_PRECISION (TREE_TYPE (size_one_node))
8466 > TREE_INT_CST_LOW (op1)
8467 && TREE_INT_CST_HIGH (op1) == 0
8468 && 0 != (t1 = convert (type,
8469 const_binop (LSHIFT_EXPR, size_one_node,
8471 && ! TREE_OVERFLOW (t1))
8472 return multiple_of_p (type, t1, bottom);
8477 /* Can't handle conversions from non-integral or wider integral type. */
8478 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
8479 || (TYPE_PRECISION (type)
8480 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
8483 /* .. fall through ... */
8486 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
8489 if (TREE_CODE (bottom) != INTEGER_CST
8490 || (TREE_UNSIGNED (type)
8491 && (tree_int_cst_sgn (top) < 0
8492 || tree_int_cst_sgn (bottom) < 0)))
8494 return integer_zerop (const_binop (TRUNC_MOD_EXPR,
8502 /* Return true if `t' is known to be non-negative. */
8505 tree_expr_nonnegative_p (tree t)
8507 switch (TREE_CODE (t))
8513 return tree_int_cst_sgn (t) >= 0;
8516 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
8519 if (FLOAT_TYPE_P (TREE_TYPE (t)))
8520 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8521 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8523 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
8524 both unsigned and at least 2 bits shorter than the result. */
8525 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
8526 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
8527 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
8529 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
8530 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
8531 if (TREE_CODE (inner1) == INTEGER_TYPE && TREE_UNSIGNED (inner1)
8532 && TREE_CODE (inner2) == INTEGER_TYPE && TREE_UNSIGNED (inner2))
8534 unsigned int prec = MAX (TYPE_PRECISION (inner1),
8535 TYPE_PRECISION (inner2)) + 1;
8536 return prec < TYPE_PRECISION (TREE_TYPE (t));
8542 if (FLOAT_TYPE_P (TREE_TYPE (t)))
8544 /* x * x for floating point x is always non-negative. */
8545 if (operand_equal_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1), 0))
8547 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8548 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8551 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
8552 both unsigned and their total bits is shorter than the result. */
8553 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
8554 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
8555 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
8557 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
8558 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
8559 if (TREE_CODE (inner1) == INTEGER_TYPE && TREE_UNSIGNED (inner1)
8560 && TREE_CODE (inner2) == INTEGER_TYPE && TREE_UNSIGNED (inner2))
8561 return TYPE_PRECISION (inner1) + TYPE_PRECISION (inner2)
8562 < TYPE_PRECISION (TREE_TYPE (t));
8566 case TRUNC_DIV_EXPR:
8568 case FLOOR_DIV_EXPR:
8569 case ROUND_DIV_EXPR:
8570 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8571 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8573 case TRUNC_MOD_EXPR:
8575 case FLOOR_MOD_EXPR:
8576 case ROUND_MOD_EXPR:
8577 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8580 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8581 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8585 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
8586 tree outer_type = TREE_TYPE (t);
8588 if (TREE_CODE (outer_type) == REAL_TYPE)
8590 if (TREE_CODE (inner_type) == REAL_TYPE)
8591 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8592 if (TREE_CODE (inner_type) == INTEGER_TYPE)
8594 if (TREE_UNSIGNED (inner_type))
8596 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8599 else if (TREE_CODE (outer_type) == INTEGER_TYPE)
8601 if (TREE_CODE (inner_type) == REAL_TYPE)
8602 return tree_expr_nonnegative_p (TREE_OPERAND (t,0));
8603 if (TREE_CODE (inner_type) == INTEGER_TYPE)
8604 return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
8605 && TREE_UNSIGNED (inner_type);
8611 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
8612 && tree_expr_nonnegative_p (TREE_OPERAND (t, 2));
8614 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8616 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8617 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8619 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8620 || tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8622 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8624 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8626 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8627 case NON_LVALUE_EXPR:
8628 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8630 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8632 return rtl_expr_nonnegative_p (RTL_EXPR_RTL (t));
8636 tree fndecl = get_callee_fndecl (t);
8637 tree arglist = TREE_OPERAND (t, 1);
8639 && DECL_BUILT_IN (fndecl)
8640 && DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_MD)
8641 switch (DECL_FUNCTION_CODE (fndecl))
8644 case BUILT_IN_CABSL:
8645 case BUILT_IN_CABSF:
8650 case BUILT_IN_EXP2F:
8651 case BUILT_IN_EXP2L:
8652 case BUILT_IN_EXP10:
8653 case BUILT_IN_EXP10F:
8654 case BUILT_IN_EXP10L:
8656 case BUILT_IN_FABSF:
8657 case BUILT_IN_FABSL:
8660 case BUILT_IN_FFSLL:
8661 case BUILT_IN_PARITY:
8662 case BUILT_IN_PARITYL:
8663 case BUILT_IN_PARITYLL:
8664 case BUILT_IN_POPCOUNT:
8665 case BUILT_IN_POPCOUNTL:
8666 case BUILT_IN_POPCOUNTLL:
8667 case BUILT_IN_POW10:
8668 case BUILT_IN_POW10F:
8669 case BUILT_IN_POW10L:
8671 case BUILT_IN_SQRTF:
8672 case BUILT_IN_SQRTL:
8676 case BUILT_IN_ATANF:
8677 case BUILT_IN_ATANL:
8679 case BUILT_IN_CEILF:
8680 case BUILT_IN_CEILL:
8681 case BUILT_IN_FLOOR:
8682 case BUILT_IN_FLOORF:
8683 case BUILT_IN_FLOORL:
8684 case BUILT_IN_NEARBYINT:
8685 case BUILT_IN_NEARBYINTF:
8686 case BUILT_IN_NEARBYINTL:
8687 case BUILT_IN_ROUND:
8688 case BUILT_IN_ROUNDF:
8689 case BUILT_IN_ROUNDL:
8690 case BUILT_IN_TRUNC:
8691 case BUILT_IN_TRUNCF:
8692 case BUILT_IN_TRUNCL:
8693 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
8698 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
8705 /* ... fall through ... */
8708 if (truth_value_p (TREE_CODE (t)))
8709 /* Truth values evaluate to 0 or 1, which is nonnegative. */
8713 /* We don't know sign of `t', so be conservative and return false. */
8717 /* Return true if `r' is known to be non-negative.
8718 Only handles constants at the moment. */
8721 rtl_expr_nonnegative_p (rtx r)
8723 switch (GET_CODE (r))
8726 return INTVAL (r) >= 0;
8729 if (GET_MODE (r) == VOIDmode)
8730 return CONST_DOUBLE_HIGH (r) >= 0;
8738 units = CONST_VECTOR_NUNITS (r);
8740 for (i = 0; i < units; ++i)
8742 elt = CONST_VECTOR_ELT (r, i);
8743 if (!rtl_expr_nonnegative_p (elt))
8752 /* These are always nonnegative. */
8760 #include "gt-fold-const.h"