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"
60 static void encode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT, HOST_WIDE_INT);
61 static void decode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
62 static bool negate_expr_p (tree);
63 static tree negate_expr (tree);
64 static tree split_tree (tree, enum tree_code, tree *, tree *, tree *, int);
65 static tree associate_trees (tree, tree, enum tree_code, tree);
66 static tree int_const_binop (enum tree_code, tree, tree, int);
67 static tree const_binop (enum tree_code, tree, tree, int);
68 static hashval_t size_htab_hash (const void *);
69 static int size_htab_eq (const void *, const void *);
70 static tree fold_convert (tree, tree);
71 static enum tree_code invert_tree_comparison (enum tree_code);
72 static enum tree_code swap_tree_comparison (enum tree_code);
73 static int comparison_to_compcode (enum tree_code);
74 static enum tree_code compcode_to_comparison (int);
75 static int truth_value_p (enum tree_code);
76 static int operand_equal_for_comparison_p (tree, tree, tree);
77 static int twoval_comparison_p (tree, tree *, tree *, int *);
78 static tree eval_subst (tree, tree, tree, tree, tree);
79 static tree pedantic_omit_one_operand (tree, tree, tree);
80 static tree distribute_bit_expr (enum tree_code, tree, tree, tree);
81 static tree make_bit_field_ref (tree, tree, int, int, int);
82 static tree optimize_bit_field_compare (enum tree_code, tree, tree, tree);
83 static tree decode_field_reference (tree, HOST_WIDE_INT *, HOST_WIDE_INT *,
84 enum machine_mode *, int *, int *,
86 static int all_ones_mask_p (tree, int);
87 static tree sign_bit_p (tree, tree);
88 static int simple_operand_p (tree);
89 static tree range_binop (enum tree_code, tree, tree, int, tree, int);
90 static tree make_range (tree, int *, tree *, tree *);
91 static tree build_range_check (tree, tree, int, tree, tree);
92 static int merge_ranges (int *, tree *, tree *, int, tree, tree, int, tree,
94 static tree fold_range_test (tree);
95 static tree unextend (tree, int, int, tree);
96 static tree fold_truthop (enum tree_code, tree, tree, tree);
97 static tree optimize_minmax_comparison (tree);
98 static tree extract_muldiv (tree, tree, enum tree_code, tree);
99 static tree extract_muldiv_1 (tree, tree, enum tree_code, tree);
100 static tree strip_compound_expr (tree, tree);
101 static int multiple_of_p (tree, tree, tree);
102 static tree constant_boolean_node (int, tree);
103 static int count_cond (tree, int);
104 static tree fold_binary_op_with_conditional_arg (enum tree_code, tree, tree,
106 static bool fold_real_zero_addition_p (tree, tree, int);
107 static tree fold_mathfn_compare (enum built_in_function, enum tree_code,
109 static tree fold_inf_compare (enum tree_code, tree, tree, tree);
111 /* The following constants represent a bit based encoding of GCC's
112 comparison operators. This encoding simplifies transformations
113 on relational comparison operators, such as AND and OR. */
114 #define COMPCODE_FALSE 0
115 #define COMPCODE_LT 1
116 #define COMPCODE_EQ 2
117 #define COMPCODE_LE 3
118 #define COMPCODE_GT 4
119 #define COMPCODE_NE 5
120 #define COMPCODE_GE 6
121 #define COMPCODE_TRUE 7
123 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
124 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
125 and SUM1. Then this yields nonzero if overflow occurred during the
128 Overflow occurs if A and B have the same sign, but A and SUM differ in
129 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
131 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
133 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
134 We do that by representing the two-word integer in 4 words, with only
135 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
136 number. The value of the word is LOWPART + HIGHPART * BASE. */
139 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
140 #define HIGHPART(x) \
141 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
142 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
144 /* Unpack a two-word integer into 4 words.
145 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
146 WORDS points to the array of HOST_WIDE_INTs. */
149 encode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT low, HOST_WIDE_INT hi)
151 words[0] = LOWPART (low);
152 words[1] = HIGHPART (low);
153 words[2] = LOWPART (hi);
154 words[3] = HIGHPART (hi);
157 /* Pack an array of 4 words into a two-word integer.
158 WORDS points to the array of words.
159 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
162 decode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT *low,
165 *low = words[0] + words[1] * BASE;
166 *hi = words[2] + words[3] * BASE;
169 /* Make the integer constant T valid for its type by setting to 0 or 1 all
170 the bits in the constant that don't belong in the type.
172 Return 1 if a signed overflow occurs, 0 otherwise. If OVERFLOW is
173 nonzero, a signed overflow has already occurred in calculating T, so
177 force_fit_type (tree t, int overflow)
179 unsigned HOST_WIDE_INT low;
183 if (TREE_CODE (t) == REAL_CST)
185 /* ??? Used to check for overflow here via CHECK_FLOAT_TYPE.
186 Consider doing it via real_convert now. */
190 else if (TREE_CODE (t) != INTEGER_CST)
193 low = TREE_INT_CST_LOW (t);
194 high = TREE_INT_CST_HIGH (t);
196 if (POINTER_TYPE_P (TREE_TYPE (t)))
199 prec = TYPE_PRECISION (TREE_TYPE (t));
201 /* First clear all bits that are beyond the type's precision. */
203 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
205 else if (prec > HOST_BITS_PER_WIDE_INT)
206 TREE_INT_CST_HIGH (t)
207 &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
210 TREE_INT_CST_HIGH (t) = 0;
211 if (prec < HOST_BITS_PER_WIDE_INT)
212 TREE_INT_CST_LOW (t) &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
215 /* Unsigned types do not suffer sign extension or overflow unless they
217 if (TREE_UNSIGNED (TREE_TYPE (t))
218 && ! (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
219 && TYPE_IS_SIZETYPE (TREE_TYPE (t))))
222 /* If the value's sign bit is set, extend the sign. */
223 if (prec != 2 * HOST_BITS_PER_WIDE_INT
224 && (prec > HOST_BITS_PER_WIDE_INT
225 ? 0 != (TREE_INT_CST_HIGH (t)
227 << (prec - HOST_BITS_PER_WIDE_INT - 1)))
228 : 0 != (TREE_INT_CST_LOW (t)
229 & ((unsigned HOST_WIDE_INT) 1 << (prec - 1)))))
231 /* Value is negative:
232 set to 1 all the bits that are outside this type's precision. */
233 if (prec > HOST_BITS_PER_WIDE_INT)
234 TREE_INT_CST_HIGH (t)
235 |= ((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
238 TREE_INT_CST_HIGH (t) = -1;
239 if (prec < HOST_BITS_PER_WIDE_INT)
240 TREE_INT_CST_LOW (t) |= ((unsigned HOST_WIDE_INT) (-1) << prec);
244 /* Return nonzero if signed overflow occurred. */
246 ((overflow | (low ^ TREE_INT_CST_LOW (t)) | (high ^ TREE_INT_CST_HIGH (t)))
250 /* Add two doubleword integers with doubleword result.
251 Each argument is given as two `HOST_WIDE_INT' pieces.
252 One argument is L1 and H1; the other, L2 and H2.
253 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
256 add_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
257 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
258 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
260 unsigned HOST_WIDE_INT l;
264 h = h1 + h2 + (l < l1);
268 return OVERFLOW_SUM_SIGN (h1, h2, h);
271 /* Negate a doubleword integer with doubleword result.
272 Return nonzero if the operation overflows, assuming it's signed.
273 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
274 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
277 neg_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
278 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
284 return (*hv & h1) < 0;
294 /* Multiply two doubleword integers with doubleword result.
295 Return nonzero if the operation overflows, assuming it's signed.
296 Each argument is given as two `HOST_WIDE_INT' pieces.
297 One argument is L1 and H1; the other, L2 and H2.
298 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
301 mul_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
302 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
303 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
305 HOST_WIDE_INT arg1[4];
306 HOST_WIDE_INT arg2[4];
307 HOST_WIDE_INT prod[4 * 2];
308 unsigned HOST_WIDE_INT carry;
310 unsigned HOST_WIDE_INT toplow, neglow;
311 HOST_WIDE_INT tophigh, neghigh;
313 encode (arg1, l1, h1);
314 encode (arg2, l2, h2);
316 memset (prod, 0, sizeof prod);
318 for (i = 0; i < 4; i++)
321 for (j = 0; j < 4; j++)
324 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
325 carry += arg1[i] * arg2[j];
326 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
328 prod[k] = LOWPART (carry);
329 carry = HIGHPART (carry);
334 decode (prod, lv, hv); /* This ignores prod[4] through prod[4*2-1] */
336 /* Check for overflow by calculating the top half of the answer in full;
337 it should agree with the low half's sign bit. */
338 decode (prod + 4, &toplow, &tophigh);
341 neg_double (l2, h2, &neglow, &neghigh);
342 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
346 neg_double (l1, h1, &neglow, &neghigh);
347 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
349 return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
352 /* Shift the doubleword integer in L1, H1 left by COUNT places
353 keeping only PREC bits of result.
354 Shift right if COUNT is negative.
355 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
356 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
359 lshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
360 HOST_WIDE_INT count, unsigned int prec,
361 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv, int arith)
363 unsigned HOST_WIDE_INT signmask;
367 rshift_double (l1, h1, -count, prec, lv, hv, arith);
371 #ifdef SHIFT_COUNT_TRUNCATED
372 if (SHIFT_COUNT_TRUNCATED)
376 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
378 /* Shifting by the host word size is undefined according to the
379 ANSI standard, so we must handle this as a special case. */
383 else if (count >= HOST_BITS_PER_WIDE_INT)
385 *hv = l1 << (count - HOST_BITS_PER_WIDE_INT);
390 *hv = (((unsigned HOST_WIDE_INT) h1 << count)
391 | (l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
395 /* Sign extend all bits that are beyond the precision. */
397 signmask = -((prec > HOST_BITS_PER_WIDE_INT
398 ? ((unsigned HOST_WIDE_INT) *hv
399 >> (prec - HOST_BITS_PER_WIDE_INT - 1))
400 : (*lv >> (prec - 1))) & 1);
402 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
404 else if (prec >= HOST_BITS_PER_WIDE_INT)
406 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
407 *hv |= signmask << (prec - HOST_BITS_PER_WIDE_INT);
412 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
413 *lv |= signmask << prec;
417 /* Shift the doubleword integer in L1, H1 right by COUNT places
418 keeping only PREC bits of result. COUNT must be positive.
419 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
420 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
423 rshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
424 HOST_WIDE_INT count, unsigned int prec,
425 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
428 unsigned HOST_WIDE_INT signmask;
431 ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
434 #ifdef SHIFT_COUNT_TRUNCATED
435 if (SHIFT_COUNT_TRUNCATED)
439 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
441 /* Shifting by the host word size is undefined according to the
442 ANSI standard, so we must handle this as a special case. */
446 else if (count >= HOST_BITS_PER_WIDE_INT)
449 *lv = (unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT);
453 *hv = (unsigned HOST_WIDE_INT) h1 >> count;
455 | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
458 /* Zero / sign extend all bits that are beyond the precision. */
460 if (count >= (HOST_WIDE_INT)prec)
465 else if ((prec - count) >= 2 * HOST_BITS_PER_WIDE_INT)
467 else if ((prec - count) >= HOST_BITS_PER_WIDE_INT)
469 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - count - HOST_BITS_PER_WIDE_INT));
470 *hv |= signmask << (prec - count - HOST_BITS_PER_WIDE_INT);
475 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << (prec - count));
476 *lv |= signmask << (prec - count);
480 /* Rotate the doubleword integer in L1, H1 left by COUNT places
481 keeping only PREC bits of result.
482 Rotate right if COUNT is negative.
483 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
486 lrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
487 HOST_WIDE_INT count, unsigned int prec,
488 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
490 unsigned HOST_WIDE_INT s1l, s2l;
491 HOST_WIDE_INT s1h, s2h;
497 lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
498 rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
503 /* Rotate the doubleword integer in L1, H1 left by COUNT places
504 keeping only PREC bits of result. COUNT must be positive.
505 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
508 rrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
509 HOST_WIDE_INT count, unsigned int prec,
510 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
512 unsigned HOST_WIDE_INT s1l, s2l;
513 HOST_WIDE_INT s1h, s2h;
519 rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
520 lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
525 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
526 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
527 CODE is a tree code for a kind of division, one of
528 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
530 It controls how the quotient is rounded to an integer.
531 Return nonzero if the operation overflows.
532 UNS nonzero says do unsigned division. */
535 div_and_round_double (enum tree_code code, int uns,
536 unsigned HOST_WIDE_INT lnum_orig, /* num == numerator == dividend */
537 HOST_WIDE_INT hnum_orig,
538 unsigned HOST_WIDE_INT lden_orig, /* den == denominator == divisor */
539 HOST_WIDE_INT hden_orig,
540 unsigned HOST_WIDE_INT *lquo,
541 HOST_WIDE_INT *hquo, unsigned HOST_WIDE_INT *lrem,
545 HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
546 HOST_WIDE_INT den[4], quo[4];
548 unsigned HOST_WIDE_INT work;
549 unsigned HOST_WIDE_INT carry = 0;
550 unsigned HOST_WIDE_INT lnum = lnum_orig;
551 HOST_WIDE_INT hnum = hnum_orig;
552 unsigned HOST_WIDE_INT lden = lden_orig;
553 HOST_WIDE_INT hden = hden_orig;
556 if (hden == 0 && lden == 0)
557 overflow = 1, lden = 1;
559 /* calculate quotient sign and convert operands to unsigned. */
565 /* (minimum integer) / (-1) is the only overflow case. */
566 if (neg_double (lnum, hnum, &lnum, &hnum)
567 && ((HOST_WIDE_INT) lden & hden) == -1)
573 neg_double (lden, hden, &lden, &hden);
577 if (hnum == 0 && hden == 0)
578 { /* single precision */
580 /* This unsigned division rounds toward zero. */
586 { /* trivial case: dividend < divisor */
587 /* hden != 0 already checked. */
594 memset (quo, 0, sizeof quo);
596 memset (num, 0, sizeof num); /* to zero 9th element */
597 memset (den, 0, sizeof den);
599 encode (num, lnum, hnum);
600 encode (den, lden, hden);
602 /* Special code for when the divisor < BASE. */
603 if (hden == 0 && lden < (unsigned HOST_WIDE_INT) BASE)
605 /* hnum != 0 already checked. */
606 for (i = 4 - 1; i >= 0; i--)
608 work = num[i] + carry * BASE;
609 quo[i] = work / lden;
615 /* Full double precision division,
616 with thanks to Don Knuth's "Seminumerical Algorithms". */
617 int num_hi_sig, den_hi_sig;
618 unsigned HOST_WIDE_INT quo_est, scale;
620 /* Find the highest nonzero divisor digit. */
621 for (i = 4 - 1;; i--)
628 /* Insure that the first digit of the divisor is at least BASE/2.
629 This is required by the quotient digit estimation algorithm. */
631 scale = BASE / (den[den_hi_sig] + 1);
633 { /* scale divisor and dividend */
635 for (i = 0; i <= 4 - 1; i++)
637 work = (num[i] * scale) + carry;
638 num[i] = LOWPART (work);
639 carry = HIGHPART (work);
644 for (i = 0; i <= 4 - 1; i++)
646 work = (den[i] * scale) + carry;
647 den[i] = LOWPART (work);
648 carry = HIGHPART (work);
649 if (den[i] != 0) den_hi_sig = i;
656 for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--)
658 /* Guess the next quotient digit, quo_est, by dividing the first
659 two remaining dividend digits by the high order quotient digit.
660 quo_est is never low and is at most 2 high. */
661 unsigned HOST_WIDE_INT tmp;
663 num_hi_sig = i + den_hi_sig + 1;
664 work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
665 if (num[num_hi_sig] != den[den_hi_sig])
666 quo_est = work / den[den_hi_sig];
670 /* Refine quo_est so it's usually correct, and at most one high. */
671 tmp = work - quo_est * den[den_hi_sig];
673 && (den[den_hi_sig - 1] * quo_est
674 > (tmp * BASE + num[num_hi_sig - 2])))
677 /* Try QUO_EST as the quotient digit, by multiplying the
678 divisor by QUO_EST and subtracting from the remaining dividend.
679 Keep in mind that QUO_EST is the I - 1st digit. */
682 for (j = 0; j <= den_hi_sig; j++)
684 work = quo_est * den[j] + carry;
685 carry = HIGHPART (work);
686 work = num[i + j] - LOWPART (work);
687 num[i + j] = LOWPART (work);
688 carry += HIGHPART (work) != 0;
691 /* If quo_est was high by one, then num[i] went negative and
692 we need to correct things. */
693 if (num[num_hi_sig] < (HOST_WIDE_INT) carry)
696 carry = 0; /* add divisor back in */
697 for (j = 0; j <= den_hi_sig; j++)
699 work = num[i + j] + den[j] + carry;
700 carry = HIGHPART (work);
701 num[i + j] = LOWPART (work);
704 num [num_hi_sig] += carry;
707 /* Store the quotient digit. */
712 decode (quo, lquo, hquo);
715 /* If result is negative, make it so. */
717 neg_double (*lquo, *hquo, lquo, hquo);
719 /* compute trial remainder: rem = num - (quo * den) */
720 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
721 neg_double (*lrem, *hrem, lrem, hrem);
722 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
727 case TRUNC_MOD_EXPR: /* round toward zero */
728 case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
732 case FLOOR_MOD_EXPR: /* round toward negative infinity */
733 if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
736 add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
744 case CEIL_MOD_EXPR: /* round toward positive infinity */
745 if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
747 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
755 case ROUND_MOD_EXPR: /* round to closest integer */
757 unsigned HOST_WIDE_INT labs_rem = *lrem;
758 HOST_WIDE_INT habs_rem = *hrem;
759 unsigned HOST_WIDE_INT labs_den = lden, ltwice;
760 HOST_WIDE_INT habs_den = hden, htwice;
762 /* Get absolute values. */
764 neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
766 neg_double (lden, hden, &labs_den, &habs_den);
768 /* If (2 * abs (lrem) >= abs (lden)) */
769 mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
770 labs_rem, habs_rem, <wice, &htwice);
772 if (((unsigned HOST_WIDE_INT) habs_den
773 < (unsigned HOST_WIDE_INT) htwice)
774 || (((unsigned HOST_WIDE_INT) habs_den
775 == (unsigned HOST_WIDE_INT) htwice)
776 && (labs_den < ltwice)))
780 add_double (*lquo, *hquo,
781 (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
784 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
796 /* compute true remainder: rem = num - (quo * den) */
797 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
798 neg_double (*lrem, *hrem, lrem, hrem);
799 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
803 /* Determine whether an expression T can be cheaply negated using
804 the function negate_expr. */
807 negate_expr_p (tree t)
809 unsigned HOST_WIDE_INT val;
816 type = TREE_TYPE (t);
819 switch (TREE_CODE (t))
822 if (TREE_UNSIGNED (type))
825 /* Check that -CST will not overflow type. */
826 prec = TYPE_PRECISION (type);
827 if (prec > HOST_BITS_PER_WIDE_INT)
829 if (TREE_INT_CST_LOW (t) != 0)
831 prec -= HOST_BITS_PER_WIDE_INT;
832 val = TREE_INT_CST_HIGH (t);
835 val = TREE_INT_CST_LOW (t);
836 if (prec < HOST_BITS_PER_WIDE_INT)
837 val &= ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
838 return val != ((unsigned HOST_WIDE_INT) 1 << (prec - 1));
851 /* Given T, an expression, return the negation of T. Allow for T to be
852 null, in which case return null. */
863 type = TREE_TYPE (t);
866 switch (TREE_CODE (t))
870 if (! TREE_UNSIGNED (type)
871 && 0 != (tem = fold (build1 (NEGATE_EXPR, type, t)))
872 && ! TREE_OVERFLOW (tem))
877 return convert (type, TREE_OPERAND (t, 0));
880 /* - (A - B) -> B - A */
881 if (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
882 return convert (type,
883 fold (build (MINUS_EXPR, TREE_TYPE (t),
885 TREE_OPERAND (t, 0))));
892 return convert (type, fold (build1 (NEGATE_EXPR, TREE_TYPE (t), t)));
895 /* Split a tree IN into a constant, literal and variable parts that could be
896 combined with CODE to make IN. "constant" means an expression with
897 TREE_CONSTANT but that isn't an actual constant. CODE must be a
898 commutative arithmetic operation. Store the constant part into *CONP,
899 the literal in *LITP and return the variable part. If a part isn't
900 present, set it to null. If the tree does not decompose in this way,
901 return the entire tree as the variable part and the other parts as null.
903 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
904 case, we negate an operand that was subtracted. Except if it is a
905 literal for which we use *MINUS_LITP instead.
907 If NEGATE_P is true, we are negating all of IN, again except a literal
908 for which we use *MINUS_LITP instead.
910 If IN is itself a literal or constant, return it as appropriate.
912 Note that we do not guarantee that any of the three values will be the
913 same type as IN, but they will have the same signedness and mode. */
916 split_tree (tree in, enum tree_code code, tree *conp, tree *litp,
917 tree *minus_litp, int negate_p)
925 /* Strip any conversions that don't change the machine mode or signedness. */
926 STRIP_SIGN_NOPS (in);
928 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST)
930 else if (TREE_CODE (in) == code
931 || (! FLOAT_TYPE_P (TREE_TYPE (in))
932 /* We can associate addition and subtraction together (even
933 though the C standard doesn't say so) for integers because
934 the value is not affected. For reals, the value might be
935 affected, so we can't. */
936 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
937 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
939 tree op0 = TREE_OPERAND (in, 0);
940 tree op1 = TREE_OPERAND (in, 1);
941 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
942 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
944 /* First see if either of the operands is a literal, then a constant. */
945 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
946 *litp = op0, op0 = 0;
947 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST)
948 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
950 if (op0 != 0 && TREE_CONSTANT (op0))
951 *conp = op0, op0 = 0;
952 else if (op1 != 0 && TREE_CONSTANT (op1))
953 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
955 /* If we haven't dealt with either operand, this is not a case we can
956 decompose. Otherwise, VAR is either of the ones remaining, if any. */
957 if (op0 != 0 && op1 != 0)
962 var = op1, neg_var_p = neg1_p;
964 /* Now do any needed negations. */
966 *minus_litp = *litp, *litp = 0;
968 *conp = negate_expr (*conp);
970 var = negate_expr (var);
972 else if (TREE_CONSTANT (in))
980 *minus_litp = *litp, *litp = 0;
981 else if (*minus_litp)
982 *litp = *minus_litp, *minus_litp = 0;
983 *conp = negate_expr (*conp);
984 var = negate_expr (var);
990 /* Re-associate trees split by the above function. T1 and T2 are either
991 expressions to associate or null. Return the new expression, if any. If
992 we build an operation, do it in TYPE and with CODE. */
995 associate_trees (tree t1, tree t2, enum tree_code code, tree type)
1002 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1003 try to fold this since we will have infinite recursion. But do
1004 deal with any NEGATE_EXPRs. */
1005 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
1006 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1008 if (code == PLUS_EXPR)
1010 if (TREE_CODE (t1) == NEGATE_EXPR)
1011 return build (MINUS_EXPR, type, convert (type, t2),
1012 convert (type, TREE_OPERAND (t1, 0)));
1013 else if (TREE_CODE (t2) == NEGATE_EXPR)
1014 return build (MINUS_EXPR, type, convert (type, t1),
1015 convert (type, TREE_OPERAND (t2, 0)));
1017 return build (code, type, convert (type, t1), convert (type, t2));
1020 return fold (build (code, type, convert (type, t1), convert (type, t2)));
1023 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1024 to produce a new constant.
1026 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1029 int_const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1031 unsigned HOST_WIDE_INT int1l, int2l;
1032 HOST_WIDE_INT int1h, int2h;
1033 unsigned HOST_WIDE_INT low;
1035 unsigned HOST_WIDE_INT garbagel;
1036 HOST_WIDE_INT garbageh;
1038 tree type = TREE_TYPE (arg1);
1039 int uns = TREE_UNSIGNED (type);
1041 = (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type));
1043 int no_overflow = 0;
1045 int1l = TREE_INT_CST_LOW (arg1);
1046 int1h = TREE_INT_CST_HIGH (arg1);
1047 int2l = TREE_INT_CST_LOW (arg2);
1048 int2h = TREE_INT_CST_HIGH (arg2);
1053 low = int1l | int2l, hi = int1h | int2h;
1057 low = int1l ^ int2l, hi = int1h ^ int2h;
1061 low = int1l & int2l, hi = int1h & int2h;
1064 case BIT_ANDTC_EXPR:
1065 low = int1l & ~int2l, hi = int1h & ~int2h;
1071 /* It's unclear from the C standard whether shifts can overflow.
1072 The following code ignores overflow; perhaps a C standard
1073 interpretation ruling is needed. */
1074 lshift_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1082 lrotate_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1087 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1091 neg_double (int2l, int2h, &low, &hi);
1092 add_double (int1l, int1h, low, hi, &low, &hi);
1093 overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
1097 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1100 case TRUNC_DIV_EXPR:
1101 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1102 case EXACT_DIV_EXPR:
1103 /* This is a shortcut for a common special case. */
1104 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1105 && ! TREE_CONSTANT_OVERFLOW (arg1)
1106 && ! TREE_CONSTANT_OVERFLOW (arg2)
1107 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1109 if (code == CEIL_DIV_EXPR)
1112 low = int1l / int2l, hi = 0;
1116 /* ... fall through ... */
1118 case ROUND_DIV_EXPR:
1119 if (int2h == 0 && int2l == 1)
1121 low = int1l, hi = int1h;
1124 if (int1l == int2l && int1h == int2h
1125 && ! (int1l == 0 && int1h == 0))
1130 overflow = div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
1131 &low, &hi, &garbagel, &garbageh);
1134 case TRUNC_MOD_EXPR:
1135 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1136 /* This is a shortcut for a common special case. */
1137 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1138 && ! TREE_CONSTANT_OVERFLOW (arg1)
1139 && ! TREE_CONSTANT_OVERFLOW (arg2)
1140 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1142 if (code == CEIL_MOD_EXPR)
1144 low = int1l % int2l, hi = 0;
1148 /* ... fall through ... */
1150 case ROUND_MOD_EXPR:
1151 overflow = div_and_round_double (code, uns,
1152 int1l, int1h, int2l, int2h,
1153 &garbagel, &garbageh, &low, &hi);
1159 low = (((unsigned HOST_WIDE_INT) int1h
1160 < (unsigned HOST_WIDE_INT) int2h)
1161 || (((unsigned HOST_WIDE_INT) int1h
1162 == (unsigned HOST_WIDE_INT) int2h)
1165 low = (int1h < int2h
1166 || (int1h == int2h && int1l < int2l));
1168 if (low == (code == MIN_EXPR))
1169 low = int1l, hi = int1h;
1171 low = int2l, hi = int2h;
1178 /* If this is for a sizetype, can be represented as one (signed)
1179 HOST_WIDE_INT word, and doesn't overflow, use size_int since it caches
1182 && ((hi == 0 && (HOST_WIDE_INT) low >= 0)
1183 || (hi == -1 && (HOST_WIDE_INT) low < 0))
1184 && overflow == 0 && ! TREE_OVERFLOW (arg1) && ! TREE_OVERFLOW (arg2))
1185 return size_int_type_wide (low, type);
1188 t = build_int_2 (low, hi);
1189 TREE_TYPE (t) = TREE_TYPE (arg1);
1194 ? (!uns || is_sizetype) && overflow
1195 : (force_fit_type (t, (!uns || is_sizetype) && overflow)
1197 | TREE_OVERFLOW (arg1)
1198 | TREE_OVERFLOW (arg2));
1200 /* If we're doing a size calculation, unsigned arithmetic does overflow.
1201 So check if force_fit_type truncated the value. */
1203 && ! TREE_OVERFLOW (t)
1204 && (TREE_INT_CST_HIGH (t) != hi
1205 || TREE_INT_CST_LOW (t) != low))
1206 TREE_OVERFLOW (t) = 1;
1208 TREE_CONSTANT_OVERFLOW (t) = (TREE_OVERFLOW (t)
1209 | TREE_CONSTANT_OVERFLOW (arg1)
1210 | TREE_CONSTANT_OVERFLOW (arg2));
1214 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1215 constant. We assume ARG1 and ARG2 have the same data type, or at least
1216 are the same kind of constant and the same machine mode.
1218 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1221 const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1226 if (TREE_CODE (arg1) == INTEGER_CST)
1227 return int_const_binop (code, arg1, arg2, notrunc);
1229 if (TREE_CODE (arg1) == REAL_CST)
1231 enum machine_mode mode;
1234 REAL_VALUE_TYPE value;
1237 d1 = TREE_REAL_CST (arg1);
1238 d2 = TREE_REAL_CST (arg2);
1240 type = TREE_TYPE (arg1);
1241 mode = TYPE_MODE (type);
1243 /* Don't perform operation if we honor signaling NaNs and
1244 either operand is a NaN. */
1245 if (HONOR_SNANS (mode)
1246 && (REAL_VALUE_ISNAN (d1) || REAL_VALUE_ISNAN (d2)))
1249 /* Don't perform operation if it would raise a division
1250 by zero exception. */
1251 if (code == RDIV_EXPR
1252 && REAL_VALUES_EQUAL (d2, dconst0)
1253 && (flag_trapping_math || ! MODE_HAS_INFINITIES (mode)))
1256 /* If either operand is a NaN, just return it. Otherwise, set up
1257 for floating-point trap; we return an overflow. */
1258 if (REAL_VALUE_ISNAN (d1))
1260 else if (REAL_VALUE_ISNAN (d2))
1263 REAL_ARITHMETIC (value, code, d1, d2);
1265 t = build_real (type, real_value_truncate (mode, value));
1268 = (force_fit_type (t, 0)
1269 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
1270 TREE_CONSTANT_OVERFLOW (t)
1272 | TREE_CONSTANT_OVERFLOW (arg1)
1273 | TREE_CONSTANT_OVERFLOW (arg2);
1276 if (TREE_CODE (arg1) == COMPLEX_CST)
1278 tree type = TREE_TYPE (arg1);
1279 tree r1 = TREE_REALPART (arg1);
1280 tree i1 = TREE_IMAGPART (arg1);
1281 tree r2 = TREE_REALPART (arg2);
1282 tree i2 = TREE_IMAGPART (arg2);
1288 t = build_complex (type,
1289 const_binop (PLUS_EXPR, r1, r2, notrunc),
1290 const_binop (PLUS_EXPR, i1, i2, notrunc));
1294 t = build_complex (type,
1295 const_binop (MINUS_EXPR, r1, r2, notrunc),
1296 const_binop (MINUS_EXPR, i1, i2, notrunc));
1300 t = build_complex (type,
1301 const_binop (MINUS_EXPR,
1302 const_binop (MULT_EXPR,
1304 const_binop (MULT_EXPR,
1307 const_binop (PLUS_EXPR,
1308 const_binop (MULT_EXPR,
1310 const_binop (MULT_EXPR,
1318 = const_binop (PLUS_EXPR,
1319 const_binop (MULT_EXPR, r2, r2, notrunc),
1320 const_binop (MULT_EXPR, i2, i2, notrunc),
1323 t = build_complex (type,
1325 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1326 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1327 const_binop (PLUS_EXPR,
1328 const_binop (MULT_EXPR, r1, r2,
1330 const_binop (MULT_EXPR, i1, i2,
1333 magsquared, notrunc),
1335 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1336 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1337 const_binop (MINUS_EXPR,
1338 const_binop (MULT_EXPR, i1, r2,
1340 const_binop (MULT_EXPR, r1, i2,
1343 magsquared, notrunc));
1355 /* These are the hash table functions for the hash table of INTEGER_CST
1356 nodes of a sizetype. */
1358 /* Return the hash code code X, an INTEGER_CST. */
1361 size_htab_hash (const void *x)
1365 return (TREE_INT_CST_HIGH (t) ^ TREE_INT_CST_LOW (t)
1366 ^ htab_hash_pointer (TREE_TYPE (t))
1367 ^ (TREE_OVERFLOW (t) << 20));
1370 /* Return nonzero if the value represented by *X (an INTEGER_CST tree node)
1371 is the same as that given by *Y, which is the same. */
1374 size_htab_eq (const void *x, const void *y)
1379 return (TREE_INT_CST_HIGH (xt) == TREE_INT_CST_HIGH (yt)
1380 && TREE_INT_CST_LOW (xt) == TREE_INT_CST_LOW (yt)
1381 && TREE_TYPE (xt) == TREE_TYPE (yt)
1382 && TREE_OVERFLOW (xt) == TREE_OVERFLOW (yt));
1385 /* Return an INTEGER_CST with value whose low-order HOST_BITS_PER_WIDE_INT
1386 bits are given by NUMBER and of the sizetype represented by KIND. */
1389 size_int_wide (HOST_WIDE_INT number, enum size_type_kind kind)
1391 return size_int_type_wide (number, sizetype_tab[(int) kind]);
1394 /* Likewise, but the desired type is specified explicitly. */
1396 static GTY (()) tree new_const;
1397 static GTY ((if_marked ("ggc_marked_p"), param_is (union tree_node)))
1401 size_int_type_wide (HOST_WIDE_INT number, tree type)
1407 size_htab = htab_create_ggc (1024, size_htab_hash, size_htab_eq, NULL);
1408 new_const = make_node (INTEGER_CST);
1411 /* Adjust NEW_CONST to be the constant we want. If it's already in the
1412 hash table, we return the value from the hash table. Otherwise, we
1413 place that in the hash table and make a new node for the next time. */
1414 TREE_INT_CST_LOW (new_const) = number;
1415 TREE_INT_CST_HIGH (new_const) = number < 0 ? -1 : 0;
1416 TREE_TYPE (new_const) = type;
1417 TREE_OVERFLOW (new_const) = TREE_CONSTANT_OVERFLOW (new_const)
1418 = force_fit_type (new_const, 0);
1420 slot = htab_find_slot (size_htab, new_const, INSERT);
1426 new_const = make_node (INTEGER_CST);
1430 return (tree) *slot;
1433 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1434 is a tree code. The type of the result is taken from the operands.
1435 Both must be the same type integer type and it must be a size type.
1436 If the operands are constant, so is the result. */
1439 size_binop (enum tree_code code, tree arg0, tree arg1)
1441 tree type = TREE_TYPE (arg0);
1443 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1444 || type != TREE_TYPE (arg1))
1447 /* Handle the special case of two integer constants faster. */
1448 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1450 /* And some specific cases even faster than that. */
1451 if (code == PLUS_EXPR && integer_zerop (arg0))
1453 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1454 && integer_zerop (arg1))
1456 else if (code == MULT_EXPR && integer_onep (arg0))
1459 /* Handle general case of two integer constants. */
1460 return int_const_binop (code, arg0, arg1, 0);
1463 if (arg0 == error_mark_node || arg1 == error_mark_node)
1464 return error_mark_node;
1466 return fold (build (code, type, arg0, arg1));
1469 /* Given two values, either both of sizetype or both of bitsizetype,
1470 compute the difference between the two values. Return the value
1471 in signed type corresponding to the type of the operands. */
1474 size_diffop (tree arg0, tree arg1)
1476 tree type = TREE_TYPE (arg0);
1479 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1480 || type != TREE_TYPE (arg1))
1483 /* If the type is already signed, just do the simple thing. */
1484 if (! TREE_UNSIGNED (type))
1485 return size_binop (MINUS_EXPR, arg0, arg1);
1487 ctype = (type == bitsizetype || type == ubitsizetype
1488 ? sbitsizetype : ssizetype);
1490 /* If either operand is not a constant, do the conversions to the signed
1491 type and subtract. The hardware will do the right thing with any
1492 overflow in the subtraction. */
1493 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
1494 return size_binop (MINUS_EXPR, convert (ctype, arg0),
1495 convert (ctype, arg1));
1497 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
1498 Otherwise, subtract the other way, convert to CTYPE (we know that can't
1499 overflow) and negate (which can't either). Special-case a result
1500 of zero while we're here. */
1501 if (tree_int_cst_equal (arg0, arg1))
1502 return convert (ctype, integer_zero_node);
1503 else if (tree_int_cst_lt (arg1, arg0))
1504 return convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
1506 return size_binop (MINUS_EXPR, convert (ctype, integer_zero_node),
1507 convert (ctype, size_binop (MINUS_EXPR, arg1, arg0)));
1511 /* Given T, a tree representing type conversion of ARG1, a constant,
1512 return a constant tree representing the result of conversion. */
1515 fold_convert (tree t, tree arg1)
1517 tree type = TREE_TYPE (t);
1520 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
1522 if (TREE_CODE (arg1) == INTEGER_CST)
1524 /* If we would build a constant wider than GCC supports,
1525 leave the conversion unfolded. */
1526 if (TYPE_PRECISION (type) > 2 * HOST_BITS_PER_WIDE_INT)
1529 /* If we are trying to make a sizetype for a small integer, use
1530 size_int to pick up cached types to reduce duplicate nodes. */
1531 if (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type)
1532 && !TREE_CONSTANT_OVERFLOW (arg1)
1533 && compare_tree_int (arg1, 10000) < 0)
1534 return size_int_type_wide (TREE_INT_CST_LOW (arg1), type);
1536 /* Given an integer constant, make new constant with new type,
1537 appropriately sign-extended or truncated. */
1538 t = build_int_2 (TREE_INT_CST_LOW (arg1),
1539 TREE_INT_CST_HIGH (arg1));
1540 TREE_TYPE (t) = type;
1541 /* Indicate an overflow if (1) ARG1 already overflowed,
1542 or (2) force_fit_type indicates an overflow.
1543 Tell force_fit_type that an overflow has already occurred
1544 if ARG1 is a too-large unsigned value and T is signed.
1545 But don't indicate an overflow if converting a pointer. */
1547 = ((force_fit_type (t,
1548 (TREE_INT_CST_HIGH (arg1) < 0
1549 && (TREE_UNSIGNED (type)
1550 < TREE_UNSIGNED (TREE_TYPE (arg1)))))
1551 && ! POINTER_TYPE_P (TREE_TYPE (arg1)))
1552 || TREE_OVERFLOW (arg1));
1553 TREE_CONSTANT_OVERFLOW (t)
1554 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1556 else if (TREE_CODE (arg1) == REAL_CST)
1558 /* Don't initialize these, use assignments.
1559 Initialized local aggregates don't work on old compilers. */
1563 tree type1 = TREE_TYPE (arg1);
1566 x = TREE_REAL_CST (arg1);
1567 l = real_value_from_int_cst (type1, TYPE_MIN_VALUE (type));
1569 no_upper_bound = (TYPE_MAX_VALUE (type) == NULL);
1570 if (!no_upper_bound)
1571 u = real_value_from_int_cst (type1, TYPE_MAX_VALUE (type));
1573 /* See if X will be in range after truncation towards 0.
1574 To compensate for truncation, move the bounds away from 0,
1575 but reject if X exactly equals the adjusted bounds. */
1576 REAL_ARITHMETIC (l, MINUS_EXPR, l, dconst1);
1577 if (!no_upper_bound)
1578 REAL_ARITHMETIC (u, PLUS_EXPR, u, dconst1);
1579 /* If X is a NaN, use zero instead and show we have an overflow.
1580 Otherwise, range check. */
1581 if (REAL_VALUE_ISNAN (x))
1582 overflow = 1, x = dconst0;
1583 else if (! (REAL_VALUES_LESS (l, x)
1585 && REAL_VALUES_LESS (x, u)))
1589 HOST_WIDE_INT low, high;
1590 REAL_VALUE_TO_INT (&low, &high, x);
1591 t = build_int_2 (low, high);
1593 TREE_TYPE (t) = type;
1595 = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
1596 TREE_CONSTANT_OVERFLOW (t)
1597 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1599 TREE_TYPE (t) = type;
1601 else if (TREE_CODE (type) == REAL_TYPE)
1603 if (TREE_CODE (arg1) == INTEGER_CST)
1604 return build_real_from_int_cst (type, arg1);
1605 if (TREE_CODE (arg1) == REAL_CST)
1607 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
1609 /* We make a copy of ARG1 so that we don't modify an
1610 existing constant tree. */
1611 t = copy_node (arg1);
1612 TREE_TYPE (t) = type;
1616 t = build_real (type,
1617 real_value_truncate (TYPE_MODE (type),
1618 TREE_REAL_CST (arg1)));
1621 = TREE_OVERFLOW (arg1) | force_fit_type (t, 0);
1622 TREE_CONSTANT_OVERFLOW (t)
1623 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1627 TREE_CONSTANT (t) = 1;
1631 /* Return an expr equal to X but certainly not valid as an lvalue. */
1638 /* These things are certainly not lvalues. */
1639 if (TREE_CODE (x) == NON_LVALUE_EXPR
1640 || TREE_CODE (x) == INTEGER_CST
1641 || TREE_CODE (x) == REAL_CST
1642 || TREE_CODE (x) == STRING_CST
1643 || TREE_CODE (x) == ADDR_EXPR)
1646 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
1647 TREE_CONSTANT (result) = TREE_CONSTANT (x);
1651 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
1652 Zero means allow extended lvalues. */
1654 int pedantic_lvalues;
1656 /* When pedantic, return an expr equal to X but certainly not valid as a
1657 pedantic lvalue. Otherwise, return X. */
1660 pedantic_non_lvalue (tree x)
1662 if (pedantic_lvalues)
1663 return non_lvalue (x);
1668 /* Given a tree comparison code, return the code that is the logical inverse
1669 of the given code. It is not safe to do this for floating-point
1670 comparisons, except for NE_EXPR and EQ_EXPR. */
1672 static enum tree_code
1673 invert_tree_comparison (enum tree_code code)
1694 /* Similar, but return the comparison that results if the operands are
1695 swapped. This is safe for floating-point. */
1697 static enum tree_code
1698 swap_tree_comparison (enum tree_code code)
1719 /* Convert a comparison tree code from an enum tree_code representation
1720 into a compcode bit-based encoding. This function is the inverse of
1721 compcode_to_comparison. */
1724 comparison_to_compcode (enum tree_code code)
1745 /* Convert a compcode bit-based encoding of a comparison operator back
1746 to GCC's enum tree_code representation. This function is the
1747 inverse of comparison_to_compcode. */
1749 static enum tree_code
1750 compcode_to_comparison (int code)
1771 /* Return nonzero if CODE is a tree code that represents a truth value. */
1774 truth_value_p (enum tree_code code)
1776 return (TREE_CODE_CLASS (code) == '<'
1777 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
1778 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
1779 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
1782 /* Return nonzero if two operands are necessarily equal.
1783 If ONLY_CONST is nonzero, only return nonzero for constants.
1784 This function tests whether the operands are indistinguishable;
1785 it does not test whether they are equal using C's == operation.
1786 The distinction is important for IEEE floating point, because
1787 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
1788 (2) two NaNs may be indistinguishable, but NaN!=NaN. */
1791 operand_equal_p (tree arg0, tree arg1, int only_const)
1793 /* If both types don't have the same signedness, then we can't consider
1794 them equal. We must check this before the STRIP_NOPS calls
1795 because they may change the signedness of the arguments. */
1796 if (TREE_UNSIGNED (TREE_TYPE (arg0)) != TREE_UNSIGNED (TREE_TYPE (arg1)))
1802 if (TREE_CODE (arg0) != TREE_CODE (arg1)
1803 /* This is needed for conversions and for COMPONENT_REF.
1804 Might as well play it safe and always test this. */
1805 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
1806 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
1807 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
1810 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
1811 We don't care about side effects in that case because the SAVE_EXPR
1812 takes care of that for us. In all other cases, two expressions are
1813 equal if they have no side effects. If we have two identical
1814 expressions with side effects that should be treated the same due
1815 to the only side effects being identical SAVE_EXPR's, that will
1816 be detected in the recursive calls below. */
1817 if (arg0 == arg1 && ! only_const
1818 && (TREE_CODE (arg0) == SAVE_EXPR
1819 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
1822 /* Next handle constant cases, those for which we can return 1 even
1823 if ONLY_CONST is set. */
1824 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
1825 switch (TREE_CODE (arg0))
1828 return (! TREE_CONSTANT_OVERFLOW (arg0)
1829 && ! TREE_CONSTANT_OVERFLOW (arg1)
1830 && tree_int_cst_equal (arg0, arg1));
1833 return (! TREE_CONSTANT_OVERFLOW (arg0)
1834 && ! TREE_CONSTANT_OVERFLOW (arg1)
1835 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
1836 TREE_REAL_CST (arg1)));
1842 if (TREE_CONSTANT_OVERFLOW (arg0)
1843 || TREE_CONSTANT_OVERFLOW (arg1))
1846 v1 = TREE_VECTOR_CST_ELTS (arg0);
1847 v2 = TREE_VECTOR_CST_ELTS (arg1);
1850 if (!operand_equal_p (v1, v2, only_const))
1852 v1 = TREE_CHAIN (v1);
1853 v2 = TREE_CHAIN (v2);
1860 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
1862 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
1866 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
1867 && ! memcmp (TREE_STRING_POINTER (arg0),
1868 TREE_STRING_POINTER (arg1),
1869 TREE_STRING_LENGTH (arg0)));
1872 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
1881 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
1884 /* Two conversions are equal only if signedness and modes match. */
1885 if ((TREE_CODE (arg0) == NOP_EXPR || TREE_CODE (arg0) == CONVERT_EXPR)
1886 && (TREE_UNSIGNED (TREE_TYPE (arg0))
1887 != TREE_UNSIGNED (TREE_TYPE (arg1))))
1890 return operand_equal_p (TREE_OPERAND (arg0, 0),
1891 TREE_OPERAND (arg1, 0), 0);
1895 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0)
1896 && operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1),
1900 /* For commutative ops, allow the other order. */
1901 return ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MULT_EXPR
1902 || TREE_CODE (arg0) == MIN_EXPR || TREE_CODE (arg0) == MAX_EXPR
1903 || TREE_CODE (arg0) == BIT_IOR_EXPR
1904 || TREE_CODE (arg0) == BIT_XOR_EXPR
1905 || TREE_CODE (arg0) == BIT_AND_EXPR
1906 || TREE_CODE (arg0) == NE_EXPR || TREE_CODE (arg0) == EQ_EXPR)
1907 && operand_equal_p (TREE_OPERAND (arg0, 0),
1908 TREE_OPERAND (arg1, 1), 0)
1909 && operand_equal_p (TREE_OPERAND (arg0, 1),
1910 TREE_OPERAND (arg1, 0), 0));
1913 /* If either of the pointer (or reference) expressions we are
1914 dereferencing contain a side effect, these cannot be equal. */
1915 if (TREE_SIDE_EFFECTS (arg0)
1916 || TREE_SIDE_EFFECTS (arg1))
1919 switch (TREE_CODE (arg0))
1922 return operand_equal_p (TREE_OPERAND (arg0, 0),
1923 TREE_OPERAND (arg1, 0), 0);
1927 case ARRAY_RANGE_REF:
1928 return (operand_equal_p (TREE_OPERAND (arg0, 0),
1929 TREE_OPERAND (arg1, 0), 0)
1930 && operand_equal_p (TREE_OPERAND (arg0, 1),
1931 TREE_OPERAND (arg1, 1), 0));
1934 return (operand_equal_p (TREE_OPERAND (arg0, 0),
1935 TREE_OPERAND (arg1, 0), 0)
1936 && operand_equal_p (TREE_OPERAND (arg0, 1),
1937 TREE_OPERAND (arg1, 1), 0)
1938 && operand_equal_p (TREE_OPERAND (arg0, 2),
1939 TREE_OPERAND (arg1, 2), 0));
1945 switch (TREE_CODE (arg0))
1948 case TRUTH_NOT_EXPR:
1949 return operand_equal_p (TREE_OPERAND (arg0, 0),
1950 TREE_OPERAND (arg1, 0), 0);
1953 return rtx_equal_p (RTL_EXPR_RTL (arg0), RTL_EXPR_RTL (arg1));
1956 /* If the CALL_EXPRs call different functions, then they
1957 clearly can not be equal. */
1958 if (! operand_equal_p (TREE_OPERAND (arg0, 0),
1959 TREE_OPERAND (arg1, 0), 0))
1962 /* Only consider const functions equivalent. */
1963 if (TREE_CODE (TREE_OPERAND (arg0, 0)) == ADDR_EXPR)
1965 tree fndecl = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
1966 if (! (flags_from_decl_or_type (fndecl) & ECF_CONST))
1972 /* Now see if all the arguments are the same. operand_equal_p
1973 does not handle TREE_LIST, so we walk the operands here
1974 feeding them to operand_equal_p. */
1975 arg0 = TREE_OPERAND (arg0, 1);
1976 arg1 = TREE_OPERAND (arg1, 1);
1977 while (arg0 && arg1)
1979 if (! operand_equal_p (TREE_VALUE (arg0), TREE_VALUE (arg1), 0))
1982 arg0 = TREE_CHAIN (arg0);
1983 arg1 = TREE_CHAIN (arg1);
1986 /* If we get here and both argument lists are exhausted
1987 then the CALL_EXPRs are equal. */
1988 return ! (arg0 || arg1);
1995 /* Consider __builtin_sqrt equal to sqrt. */
1996 return TREE_CODE (arg0) == FUNCTION_DECL
1997 && DECL_BUILT_IN (arg0) && DECL_BUILT_IN (arg1)
1998 && DECL_BUILT_IN_CLASS (arg0) == DECL_BUILT_IN_CLASS (arg1)
1999 && DECL_FUNCTION_CODE (arg0) == DECL_FUNCTION_CODE (arg1);
2006 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2007 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2009 When in doubt, return 0. */
2012 operand_equal_for_comparison_p (tree arg0, tree arg1, tree other)
2014 int unsignedp1, unsignedpo;
2015 tree primarg0, primarg1, primother;
2016 unsigned int correct_width;
2018 if (operand_equal_p (arg0, arg1, 0))
2021 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
2022 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
2025 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2026 and see if the inner values are the same. This removes any
2027 signedness comparison, which doesn't matter here. */
2028 primarg0 = arg0, primarg1 = arg1;
2029 STRIP_NOPS (primarg0);
2030 STRIP_NOPS (primarg1);
2031 if (operand_equal_p (primarg0, primarg1, 0))
2034 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2035 actual comparison operand, ARG0.
2037 First throw away any conversions to wider types
2038 already present in the operands. */
2040 primarg1 = get_narrower (arg1, &unsignedp1);
2041 primother = get_narrower (other, &unsignedpo);
2043 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
2044 if (unsignedp1 == unsignedpo
2045 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
2046 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
2048 tree type = TREE_TYPE (arg0);
2050 /* Make sure shorter operand is extended the right way
2051 to match the longer operand. */
2052 primarg1 = convert ((*lang_hooks.types.signed_or_unsigned_type)
2053 (unsignedp1, TREE_TYPE (primarg1)), primarg1);
2055 if (operand_equal_p (arg0, convert (type, primarg1), 0))
2062 /* See if ARG is an expression that is either a comparison or is performing
2063 arithmetic on comparisons. The comparisons must only be comparing
2064 two different values, which will be stored in *CVAL1 and *CVAL2; if
2065 they are nonzero it means that some operands have already been found.
2066 No variables may be used anywhere else in the expression except in the
2067 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2068 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2070 If this is true, return 1. Otherwise, return zero. */
2073 twoval_comparison_p (tree arg, tree *cval1, tree *cval2, int *save_p)
2075 enum tree_code code = TREE_CODE (arg);
2076 char class = TREE_CODE_CLASS (code);
2078 /* We can handle some of the 'e' cases here. */
2079 if (class == 'e' && code == TRUTH_NOT_EXPR)
2081 else if (class == 'e'
2082 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
2083 || code == COMPOUND_EXPR))
2086 else if (class == 'e' && code == SAVE_EXPR && SAVE_EXPR_RTL (arg) == 0
2087 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
2089 /* If we've already found a CVAL1 or CVAL2, this expression is
2090 two complex to handle. */
2091 if (*cval1 || *cval2)
2101 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
2104 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
2105 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2106 cval1, cval2, save_p));
2112 if (code == COND_EXPR)
2113 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
2114 cval1, cval2, save_p)
2115 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2116 cval1, cval2, save_p)
2117 && twoval_comparison_p (TREE_OPERAND (arg, 2),
2118 cval1, cval2, save_p));
2122 /* First see if we can handle the first operand, then the second. For
2123 the second operand, we know *CVAL1 can't be zero. It must be that
2124 one side of the comparison is each of the values; test for the
2125 case where this isn't true by failing if the two operands
2128 if (operand_equal_p (TREE_OPERAND (arg, 0),
2129 TREE_OPERAND (arg, 1), 0))
2133 *cval1 = TREE_OPERAND (arg, 0);
2134 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
2136 else if (*cval2 == 0)
2137 *cval2 = TREE_OPERAND (arg, 0);
2138 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
2143 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
2145 else if (*cval2 == 0)
2146 *cval2 = TREE_OPERAND (arg, 1);
2147 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
2159 /* ARG is a tree that is known to contain just arithmetic operations and
2160 comparisons. Evaluate the operations in the tree substituting NEW0 for
2161 any occurrence of OLD0 as an operand of a comparison and likewise for
2165 eval_subst (tree arg, tree old0, tree new0, tree old1, tree new1)
2167 tree type = TREE_TYPE (arg);
2168 enum tree_code code = TREE_CODE (arg);
2169 char class = TREE_CODE_CLASS (code);
2171 /* We can handle some of the 'e' cases here. */
2172 if (class == 'e' && code == TRUTH_NOT_EXPR)
2174 else if (class == 'e'
2175 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2181 return fold (build1 (code, type,
2182 eval_subst (TREE_OPERAND (arg, 0),
2183 old0, new0, old1, new1)));
2186 return fold (build (code, type,
2187 eval_subst (TREE_OPERAND (arg, 0),
2188 old0, new0, old1, new1),
2189 eval_subst (TREE_OPERAND (arg, 1),
2190 old0, new0, old1, new1)));
2196 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
2199 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
2202 return fold (build (code, type,
2203 eval_subst (TREE_OPERAND (arg, 0),
2204 old0, new0, old1, new1),
2205 eval_subst (TREE_OPERAND (arg, 1),
2206 old0, new0, old1, new1),
2207 eval_subst (TREE_OPERAND (arg, 2),
2208 old0, new0, old1, new1)));
2212 /* Fall through - ??? */
2216 tree arg0 = TREE_OPERAND (arg, 0);
2217 tree arg1 = TREE_OPERAND (arg, 1);
2219 /* We need to check both for exact equality and tree equality. The
2220 former will be true if the operand has a side-effect. In that
2221 case, we know the operand occurred exactly once. */
2223 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
2225 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
2228 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
2230 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
2233 return fold (build (code, type, arg0, arg1));
2241 /* Return a tree for the case when the result of an expression is RESULT
2242 converted to TYPE and OMITTED was previously an operand of the expression
2243 but is now not needed (e.g., we folded OMITTED * 0).
2245 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2246 the conversion of RESULT to TYPE. */
2249 omit_one_operand (tree type, tree result, tree omitted)
2251 tree t = convert (type, result);
2253 if (TREE_SIDE_EFFECTS (omitted))
2254 return build (COMPOUND_EXPR, type, omitted, t);
2256 return non_lvalue (t);
2259 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2262 pedantic_omit_one_operand (tree type, tree result, tree omitted)
2264 tree t = convert (type, result);
2266 if (TREE_SIDE_EFFECTS (omitted))
2267 return build (COMPOUND_EXPR, type, omitted, t);
2269 return pedantic_non_lvalue (t);
2272 /* Return a simplified tree node for the truth-negation of ARG. This
2273 never alters ARG itself. We assume that ARG is an operation that
2274 returns a truth value (0 or 1). */
2277 invert_truthvalue (tree arg)
2279 tree type = TREE_TYPE (arg);
2280 enum tree_code code = TREE_CODE (arg);
2282 if (code == ERROR_MARK)
2285 /* If this is a comparison, we can simply invert it, except for
2286 floating-point non-equality comparisons, in which case we just
2287 enclose a TRUTH_NOT_EXPR around what we have. */
2289 if (TREE_CODE_CLASS (code) == '<')
2291 if (FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg, 0)))
2292 && !flag_unsafe_math_optimizations
2295 return build1 (TRUTH_NOT_EXPR, type, arg);
2297 return build (invert_tree_comparison (code), type,
2298 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
2304 return convert (type, build_int_2 (integer_zerop (arg), 0));
2306 case TRUTH_AND_EXPR:
2307 return build (TRUTH_OR_EXPR, type,
2308 invert_truthvalue (TREE_OPERAND (arg, 0)),
2309 invert_truthvalue (TREE_OPERAND (arg, 1)));
2312 return build (TRUTH_AND_EXPR, type,
2313 invert_truthvalue (TREE_OPERAND (arg, 0)),
2314 invert_truthvalue (TREE_OPERAND (arg, 1)));
2316 case TRUTH_XOR_EXPR:
2317 /* Here we can invert either operand. We invert the first operand
2318 unless the second operand is a TRUTH_NOT_EXPR in which case our
2319 result is the XOR of the first operand with the inside of the
2320 negation of the second operand. */
2322 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
2323 return build (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
2324 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
2326 return build (TRUTH_XOR_EXPR, type,
2327 invert_truthvalue (TREE_OPERAND (arg, 0)),
2328 TREE_OPERAND (arg, 1));
2330 case TRUTH_ANDIF_EXPR:
2331 return build (TRUTH_ORIF_EXPR, type,
2332 invert_truthvalue (TREE_OPERAND (arg, 0)),
2333 invert_truthvalue (TREE_OPERAND (arg, 1)));
2335 case TRUTH_ORIF_EXPR:
2336 return build (TRUTH_ANDIF_EXPR, type,
2337 invert_truthvalue (TREE_OPERAND (arg, 0)),
2338 invert_truthvalue (TREE_OPERAND (arg, 1)));
2340 case TRUTH_NOT_EXPR:
2341 return TREE_OPERAND (arg, 0);
2344 return build (COND_EXPR, type, TREE_OPERAND (arg, 0),
2345 invert_truthvalue (TREE_OPERAND (arg, 1)),
2346 invert_truthvalue (TREE_OPERAND (arg, 2)));
2349 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
2350 invert_truthvalue (TREE_OPERAND (arg, 1)));
2352 case WITH_RECORD_EXPR:
2353 return build (WITH_RECORD_EXPR, type,
2354 invert_truthvalue (TREE_OPERAND (arg, 0)),
2355 TREE_OPERAND (arg, 1));
2357 case NON_LVALUE_EXPR:
2358 return invert_truthvalue (TREE_OPERAND (arg, 0));
2363 return build1 (TREE_CODE (arg), type,
2364 invert_truthvalue (TREE_OPERAND (arg, 0)));
2367 if (!integer_onep (TREE_OPERAND (arg, 1)))
2369 return build (EQ_EXPR, type, arg, convert (type, integer_zero_node));
2372 return build1 (TRUTH_NOT_EXPR, type, arg);
2374 case CLEANUP_POINT_EXPR:
2375 return build1 (CLEANUP_POINT_EXPR, type,
2376 invert_truthvalue (TREE_OPERAND (arg, 0)));
2381 if (TREE_CODE (TREE_TYPE (arg)) != BOOLEAN_TYPE)
2383 return build1 (TRUTH_NOT_EXPR, type, arg);
2386 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
2387 operands are another bit-wise operation with a common input. If so,
2388 distribute the bit operations to save an operation and possibly two if
2389 constants are involved. For example, convert
2390 (A | B) & (A | C) into A | (B & C)
2391 Further simplification will occur if B and C are constants.
2393 If this optimization cannot be done, 0 will be returned. */
2396 distribute_bit_expr (enum tree_code code, tree type, tree arg0, tree arg1)
2401 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2402 || TREE_CODE (arg0) == code
2403 || (TREE_CODE (arg0) != BIT_AND_EXPR
2404 && TREE_CODE (arg0) != BIT_IOR_EXPR))
2407 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
2409 common = TREE_OPERAND (arg0, 0);
2410 left = TREE_OPERAND (arg0, 1);
2411 right = TREE_OPERAND (arg1, 1);
2413 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
2415 common = TREE_OPERAND (arg0, 0);
2416 left = TREE_OPERAND (arg0, 1);
2417 right = TREE_OPERAND (arg1, 0);
2419 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
2421 common = TREE_OPERAND (arg0, 1);
2422 left = TREE_OPERAND (arg0, 0);
2423 right = TREE_OPERAND (arg1, 1);
2425 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
2427 common = TREE_OPERAND (arg0, 1);
2428 left = TREE_OPERAND (arg0, 0);
2429 right = TREE_OPERAND (arg1, 0);
2434 return fold (build (TREE_CODE (arg0), type, common,
2435 fold (build (code, type, left, right))));
2438 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
2439 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
2442 make_bit_field_ref (tree inner, tree type, int bitsize, int bitpos,
2445 tree result = build (BIT_FIELD_REF, type, inner,
2446 size_int (bitsize), bitsize_int (bitpos));
2448 TREE_UNSIGNED (result) = unsignedp;
2453 /* Optimize a bit-field compare.
2455 There are two cases: First is a compare against a constant and the
2456 second is a comparison of two items where the fields are at the same
2457 bit position relative to the start of a chunk (byte, halfword, word)
2458 large enough to contain it. In these cases we can avoid the shift
2459 implicit in bitfield extractions.
2461 For constants, we emit a compare of the shifted constant with the
2462 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
2463 compared. For two fields at the same position, we do the ANDs with the
2464 similar mask and compare the result of the ANDs.
2466 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
2467 COMPARE_TYPE is the type of the comparison, and LHS and RHS
2468 are the left and right operands of the comparison, respectively.
2470 If the optimization described above can be done, we return the resulting
2471 tree. Otherwise we return zero. */
2474 optimize_bit_field_compare (enum tree_code code, tree compare_type,
2477 HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
2478 tree type = TREE_TYPE (lhs);
2479 tree signed_type, unsigned_type;
2480 int const_p = TREE_CODE (rhs) == INTEGER_CST;
2481 enum machine_mode lmode, rmode, nmode;
2482 int lunsignedp, runsignedp;
2483 int lvolatilep = 0, rvolatilep = 0;
2484 tree linner, rinner = NULL_TREE;
2488 /* Get all the information about the extractions being done. If the bit size
2489 if the same as the size of the underlying object, we aren't doing an
2490 extraction at all and so can do nothing. We also don't want to
2491 do anything if the inner expression is a PLACEHOLDER_EXPR since we
2492 then will no longer be able to replace it. */
2493 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
2494 &lunsignedp, &lvolatilep);
2495 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
2496 || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
2501 /* If this is not a constant, we can only do something if bit positions,
2502 sizes, and signedness are the same. */
2503 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
2504 &runsignedp, &rvolatilep);
2506 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
2507 || lunsignedp != runsignedp || offset != 0
2508 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
2512 /* See if we can find a mode to refer to this field. We should be able to,
2513 but fail if we can't. */
2514 nmode = get_best_mode (lbitsize, lbitpos,
2515 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
2516 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
2517 TYPE_ALIGN (TREE_TYPE (rinner))),
2518 word_mode, lvolatilep || rvolatilep);
2519 if (nmode == VOIDmode)
2522 /* Set signed and unsigned types of the precision of this mode for the
2524 signed_type = (*lang_hooks.types.type_for_mode) (nmode, 0);
2525 unsigned_type = (*lang_hooks.types.type_for_mode) (nmode, 1);
2527 /* Compute the bit position and size for the new reference and our offset
2528 within it. If the new reference is the same size as the original, we
2529 won't optimize anything, so return zero. */
2530 nbitsize = GET_MODE_BITSIZE (nmode);
2531 nbitpos = lbitpos & ~ (nbitsize - 1);
2533 if (nbitsize == lbitsize)
2536 if (BYTES_BIG_ENDIAN)
2537 lbitpos = nbitsize - lbitsize - lbitpos;
2539 /* Make the mask to be used against the extracted field. */
2540 mask = build_int_2 (~0, ~0);
2541 TREE_TYPE (mask) = unsigned_type;
2542 force_fit_type (mask, 0);
2543 mask = convert (unsigned_type, mask);
2544 mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
2545 mask = const_binop (RSHIFT_EXPR, mask,
2546 size_int (nbitsize - lbitsize - lbitpos), 0);
2549 /* If not comparing with constant, just rework the comparison
2551 return build (code, compare_type,
2552 build (BIT_AND_EXPR, unsigned_type,
2553 make_bit_field_ref (linner, unsigned_type,
2554 nbitsize, nbitpos, 1),
2556 build (BIT_AND_EXPR, unsigned_type,
2557 make_bit_field_ref (rinner, unsigned_type,
2558 nbitsize, nbitpos, 1),
2561 /* Otherwise, we are handling the constant case. See if the constant is too
2562 big for the field. Warn and return a tree of for 0 (false) if so. We do
2563 this not only for its own sake, but to avoid having to test for this
2564 error case below. If we didn't, we might generate wrong code.
2566 For unsigned fields, the constant shifted right by the field length should
2567 be all zero. For signed fields, the high-order bits should agree with
2572 if (! integer_zerop (const_binop (RSHIFT_EXPR,
2573 convert (unsigned_type, rhs),
2574 size_int (lbitsize), 0)))
2576 warning ("comparison is always %d due to width of bit-field",
2578 return convert (compare_type,
2580 ? integer_one_node : integer_zero_node));
2585 tree tem = const_binop (RSHIFT_EXPR, convert (signed_type, rhs),
2586 size_int (lbitsize - 1), 0);
2587 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
2589 warning ("comparison is always %d due to width of bit-field",
2591 return convert (compare_type,
2593 ? integer_one_node : integer_zero_node));
2597 /* Single-bit compares should always be against zero. */
2598 if (lbitsize == 1 && ! integer_zerop (rhs))
2600 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
2601 rhs = convert (type, integer_zero_node);
2604 /* Make a new bitfield reference, shift the constant over the
2605 appropriate number of bits and mask it with the computed mask
2606 (in case this was a signed field). If we changed it, make a new one. */
2607 lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1);
2610 TREE_SIDE_EFFECTS (lhs) = 1;
2611 TREE_THIS_VOLATILE (lhs) = 1;
2614 rhs = fold (const_binop (BIT_AND_EXPR,
2615 const_binop (LSHIFT_EXPR,
2616 convert (unsigned_type, rhs),
2617 size_int (lbitpos), 0),
2620 return build (code, compare_type,
2621 build (BIT_AND_EXPR, unsigned_type, lhs, mask),
2625 /* Subroutine for fold_truthop: decode a field reference.
2627 If EXP is a comparison reference, we return the innermost reference.
2629 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
2630 set to the starting bit number.
2632 If the innermost field can be completely contained in a mode-sized
2633 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
2635 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
2636 otherwise it is not changed.
2638 *PUNSIGNEDP is set to the signedness of the field.
2640 *PMASK is set to the mask used. This is either contained in a
2641 BIT_AND_EXPR or derived from the width of the field.
2643 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
2645 Return 0 if this is not a component reference or is one that we can't
2646 do anything with. */
2649 decode_field_reference (tree exp, HOST_WIDE_INT *pbitsize,
2650 HOST_WIDE_INT *pbitpos, enum machine_mode *pmode,
2651 int *punsignedp, int *pvolatilep,
2652 tree *pmask, tree *pand_mask)
2654 tree outer_type = 0;
2656 tree mask, inner, offset;
2658 unsigned int precision;
2660 /* All the optimizations using this function assume integer fields.
2661 There are problems with FP fields since the type_for_size call
2662 below can fail for, e.g., XFmode. */
2663 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
2666 /* We are interested in the bare arrangement of bits, so strip everything
2667 that doesn't affect the machine mode. However, record the type of the
2668 outermost expression if it may matter below. */
2669 if (TREE_CODE (exp) == NOP_EXPR
2670 || TREE_CODE (exp) == CONVERT_EXPR
2671 || TREE_CODE (exp) == NON_LVALUE_EXPR)
2672 outer_type = TREE_TYPE (exp);
2675 if (TREE_CODE (exp) == BIT_AND_EXPR)
2677 and_mask = TREE_OPERAND (exp, 1);
2678 exp = TREE_OPERAND (exp, 0);
2679 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
2680 if (TREE_CODE (and_mask) != INTEGER_CST)
2684 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
2685 punsignedp, pvolatilep);
2686 if ((inner == exp && and_mask == 0)
2687 || *pbitsize < 0 || offset != 0
2688 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
2691 /* If the number of bits in the reference is the same as the bitsize of
2692 the outer type, then the outer type gives the signedness. Otherwise
2693 (in case of a small bitfield) the signedness is unchanged. */
2694 if (outer_type && *pbitsize == tree_low_cst (TYPE_SIZE (outer_type), 1))
2695 *punsignedp = TREE_UNSIGNED (outer_type);
2697 /* Compute the mask to access the bitfield. */
2698 unsigned_type = (*lang_hooks.types.type_for_size) (*pbitsize, 1);
2699 precision = TYPE_PRECISION (unsigned_type);
2701 mask = build_int_2 (~0, ~0);
2702 TREE_TYPE (mask) = unsigned_type;
2703 force_fit_type (mask, 0);
2704 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
2705 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
2707 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
2709 mask = fold (build (BIT_AND_EXPR, unsigned_type,
2710 convert (unsigned_type, and_mask), mask));
2713 *pand_mask = and_mask;
2717 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
2721 all_ones_mask_p (tree mask, int size)
2723 tree type = TREE_TYPE (mask);
2724 unsigned int precision = TYPE_PRECISION (type);
2727 tmask = build_int_2 (~0, ~0);
2728 TREE_TYPE (tmask) = (*lang_hooks.types.signed_type) (type);
2729 force_fit_type (tmask, 0);
2731 tree_int_cst_equal (mask,
2732 const_binop (RSHIFT_EXPR,
2733 const_binop (LSHIFT_EXPR, tmask,
2734 size_int (precision - size),
2736 size_int (precision - size), 0));
2739 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
2740 represents the sign bit of EXP's type. If EXP represents a sign
2741 or zero extension, also test VAL against the unextended type.
2742 The return value is the (sub)expression whose sign bit is VAL,
2743 or NULL_TREE otherwise. */
2746 sign_bit_p (tree exp, tree val)
2748 unsigned HOST_WIDE_INT mask_lo, lo;
2749 HOST_WIDE_INT mask_hi, hi;
2753 /* Tree EXP must have an integral type. */
2754 t = TREE_TYPE (exp);
2755 if (! INTEGRAL_TYPE_P (t))
2758 /* Tree VAL must be an integer constant. */
2759 if (TREE_CODE (val) != INTEGER_CST
2760 || TREE_CONSTANT_OVERFLOW (val))
2763 width = TYPE_PRECISION (t);
2764 if (width > HOST_BITS_PER_WIDE_INT)
2766 hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1);
2769 mask_hi = ((unsigned HOST_WIDE_INT) -1
2770 >> (2 * HOST_BITS_PER_WIDE_INT - width));
2776 lo = (unsigned HOST_WIDE_INT) 1 << (width - 1);
2779 mask_lo = ((unsigned HOST_WIDE_INT) -1
2780 >> (HOST_BITS_PER_WIDE_INT - width));
2783 /* We mask off those bits beyond TREE_TYPE (exp) so that we can
2784 treat VAL as if it were unsigned. */
2785 if ((TREE_INT_CST_HIGH (val) & mask_hi) == hi
2786 && (TREE_INT_CST_LOW (val) & mask_lo) == lo)
2789 /* Handle extension from a narrower type. */
2790 if (TREE_CODE (exp) == NOP_EXPR
2791 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width)
2792 return sign_bit_p (TREE_OPERAND (exp, 0), val);
2797 /* Subroutine for fold_truthop: determine if an operand is simple enough
2798 to be evaluated unconditionally. */
2801 simple_operand_p (tree exp)
2803 /* Strip any conversions that don't change the machine mode. */
2804 while ((TREE_CODE (exp) == NOP_EXPR
2805 || TREE_CODE (exp) == CONVERT_EXPR)
2806 && (TYPE_MODE (TREE_TYPE (exp))
2807 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)))))
2808 exp = TREE_OPERAND (exp, 0);
2810 return (TREE_CODE_CLASS (TREE_CODE (exp)) == 'c'
2812 && ! TREE_ADDRESSABLE (exp)
2813 && ! TREE_THIS_VOLATILE (exp)
2814 && ! DECL_NONLOCAL (exp)
2815 /* Don't regard global variables as simple. They may be
2816 allocated in ways unknown to the compiler (shared memory,
2817 #pragma weak, etc). */
2818 && ! TREE_PUBLIC (exp)
2819 && ! DECL_EXTERNAL (exp)
2820 /* Loading a static variable is unduly expensive, but global
2821 registers aren't expensive. */
2822 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
2825 /* The following functions are subroutines to fold_range_test and allow it to
2826 try to change a logical combination of comparisons into a range test.
2829 X == 2 || X == 3 || X == 4 || X == 5
2833 (unsigned) (X - 2) <= 3
2835 We describe each set of comparisons as being either inside or outside
2836 a range, using a variable named like IN_P, and then describe the
2837 range with a lower and upper bound. If one of the bounds is omitted,
2838 it represents either the highest or lowest value of the type.
2840 In the comments below, we represent a range by two numbers in brackets
2841 preceded by a "+" to designate being inside that range, or a "-" to
2842 designate being outside that range, so the condition can be inverted by
2843 flipping the prefix. An omitted bound is represented by a "-". For
2844 example, "- [-, 10]" means being outside the range starting at the lowest
2845 possible value and ending at 10, in other words, being greater than 10.
2846 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
2849 We set up things so that the missing bounds are handled in a consistent
2850 manner so neither a missing bound nor "true" and "false" need to be
2851 handled using a special case. */
2853 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
2854 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
2855 and UPPER1_P are nonzero if the respective argument is an upper bound
2856 and zero for a lower. TYPE, if nonzero, is the type of the result; it
2857 must be specified for a comparison. ARG1 will be converted to ARG0's
2858 type if both are specified. */
2861 range_binop (enum tree_code code, tree type, tree arg0, int upper0_p,
2862 tree arg1, int upper1_p)
2868 /* If neither arg represents infinity, do the normal operation.
2869 Else, if not a comparison, return infinity. Else handle the special
2870 comparison rules. Note that most of the cases below won't occur, but
2871 are handled for consistency. */
2873 if (arg0 != 0 && arg1 != 0)
2875 tem = fold (build (code, type != 0 ? type : TREE_TYPE (arg0),
2876 arg0, convert (TREE_TYPE (arg0), arg1)));
2878 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
2881 if (TREE_CODE_CLASS (code) != '<')
2884 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
2885 for neither. In real maths, we cannot assume open ended ranges are
2886 the same. But, this is computer arithmetic, where numbers are finite.
2887 We can therefore make the transformation of any unbounded range with
2888 the value Z, Z being greater than any representable number. This permits
2889 us to treat unbounded ranges as equal. */
2890 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
2891 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
2895 result = sgn0 == sgn1;
2898 result = sgn0 != sgn1;
2901 result = sgn0 < sgn1;
2904 result = sgn0 <= sgn1;
2907 result = sgn0 > sgn1;
2910 result = sgn0 >= sgn1;
2916 return convert (type, result ? integer_one_node : integer_zero_node);
2919 /* Given EXP, a logical expression, set the range it is testing into
2920 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
2921 actually being tested. *PLOW and *PHIGH will be made of the same type
2922 as the returned expression. If EXP is not a comparison, we will most
2923 likely not be returning a useful value and range. */
2926 make_range (tree exp, int *pin_p, tree *plow, tree *phigh)
2928 enum tree_code code;
2929 tree arg0 = NULL_TREE, arg1 = NULL_TREE, type = NULL_TREE;
2930 tree orig_type = NULL_TREE;
2932 tree low, high, n_low, n_high;
2934 /* Start with simply saying "EXP != 0" and then look at the code of EXP
2935 and see if we can refine the range. Some of the cases below may not
2936 happen, but it doesn't seem worth worrying about this. We "continue"
2937 the outer loop when we've changed something; otherwise we "break"
2938 the switch, which will "break" the while. */
2940 in_p = 0, low = high = convert (TREE_TYPE (exp), integer_zero_node);
2944 code = TREE_CODE (exp);
2946 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
2948 if (first_rtl_op (code) > 0)
2949 arg0 = TREE_OPERAND (exp, 0);
2950 if (TREE_CODE_CLASS (code) == '<'
2951 || TREE_CODE_CLASS (code) == '1'
2952 || TREE_CODE_CLASS (code) == '2')
2953 type = TREE_TYPE (arg0);
2954 if (TREE_CODE_CLASS (code) == '2'
2955 || TREE_CODE_CLASS (code) == '<'
2956 || (TREE_CODE_CLASS (code) == 'e'
2957 && TREE_CODE_LENGTH (code) > 1))
2958 arg1 = TREE_OPERAND (exp, 1);
2961 /* Set ORIG_TYPE as soon as TYPE is non-null so that we do not
2962 lose a cast by accident. */
2963 if (type != NULL_TREE && orig_type == NULL_TREE)
2968 case TRUTH_NOT_EXPR:
2969 in_p = ! in_p, exp = arg0;
2972 case EQ_EXPR: case NE_EXPR:
2973 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
2974 /* We can only do something if the range is testing for zero
2975 and if the second operand is an integer constant. Note that
2976 saying something is "in" the range we make is done by
2977 complementing IN_P since it will set in the initial case of
2978 being not equal to zero; "out" is leaving it alone. */
2979 if (low == 0 || high == 0
2980 || ! integer_zerop (low) || ! integer_zerop (high)
2981 || TREE_CODE (arg1) != INTEGER_CST)
2986 case NE_EXPR: /* - [c, c] */
2989 case EQ_EXPR: /* + [c, c] */
2990 in_p = ! in_p, low = high = arg1;
2992 case GT_EXPR: /* - [-, c] */
2993 low = 0, high = arg1;
2995 case GE_EXPR: /* + [c, -] */
2996 in_p = ! in_p, low = arg1, high = 0;
2998 case LT_EXPR: /* - [c, -] */
2999 low = arg1, high = 0;
3001 case LE_EXPR: /* + [-, c] */
3002 in_p = ! in_p, low = 0, high = arg1;
3010 /* If this is an unsigned comparison, we also know that EXP is
3011 greater than or equal to zero. We base the range tests we make
3012 on that fact, so we record it here so we can parse existing
3014 if (TREE_UNSIGNED (type) && (low == 0 || high == 0))
3016 if (! merge_ranges (&n_in_p, &n_low, &n_high, in_p, low, high,
3017 1, convert (type, integer_zero_node),
3021 in_p = n_in_p, low = n_low, high = n_high;
3023 /* If the high bound is missing, but we
3024 have a low bound, reverse the range so
3025 it goes from zero to the low bound minus 1. */
3026 if (high == 0 && low)
3029 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
3030 integer_one_node, 0);
3031 low = convert (type, integer_zero_node);
3037 /* (-x) IN [a,b] -> x in [-b, -a] */
3038 n_low = range_binop (MINUS_EXPR, type,
3039 convert (type, integer_zero_node), 0, high, 1);
3040 n_high = range_binop (MINUS_EXPR, type,
3041 convert (type, integer_zero_node), 0, low, 0);
3042 low = n_low, high = n_high;
3048 exp = build (MINUS_EXPR, type, negate_expr (arg0),
3049 convert (type, integer_one_node));
3052 case PLUS_EXPR: case MINUS_EXPR:
3053 if (TREE_CODE (arg1) != INTEGER_CST)
3056 /* If EXP is signed, any overflow in the computation is undefined,
3057 so we don't worry about it so long as our computations on
3058 the bounds don't overflow. For unsigned, overflow is defined
3059 and this is exactly the right thing. */
3060 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3061 type, low, 0, arg1, 0);
3062 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3063 type, high, 1, arg1, 0);
3064 if ((n_low != 0 && TREE_OVERFLOW (n_low))
3065 || (n_high != 0 && TREE_OVERFLOW (n_high)))
3068 /* Check for an unsigned range which has wrapped around the maximum
3069 value thus making n_high < n_low, and normalize it. */
3070 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
3072 low = range_binop (PLUS_EXPR, type, n_high, 0,
3073 integer_one_node, 0);
3074 high = range_binop (MINUS_EXPR, type, n_low, 0,
3075 integer_one_node, 0);
3077 /* If the range is of the form +/- [ x+1, x ], we won't
3078 be able to normalize it. But then, it represents the
3079 whole range or the empty set, so make it
3081 if (tree_int_cst_equal (n_low, low)
3082 && tree_int_cst_equal (n_high, high))
3088 low = n_low, high = n_high;
3093 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
3094 if (TYPE_PRECISION (type) > TYPE_PRECISION (orig_type))
3097 if (! INTEGRAL_TYPE_P (type)
3098 || (low != 0 && ! int_fits_type_p (low, type))
3099 || (high != 0 && ! int_fits_type_p (high, type)))
3102 n_low = low, n_high = high;
3105 n_low = convert (type, n_low);
3108 n_high = convert (type, n_high);
3110 /* If we're converting from an unsigned to a signed type,
3111 we will be doing the comparison as unsigned. The tests above
3112 have already verified that LOW and HIGH are both positive.
3114 So we have to make sure that the original unsigned value will
3115 be interpreted as positive. */
3116 if (TREE_UNSIGNED (type) && ! TREE_UNSIGNED (TREE_TYPE (exp)))
3118 tree equiv_type = (*lang_hooks.types.type_for_mode)
3119 (TYPE_MODE (type), 1);
3122 /* A range without an upper bound is, naturally, unbounded.
3123 Since convert would have cropped a very large value, use
3124 the max value for the destination type. */
3126 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
3127 : TYPE_MAX_VALUE (type);
3129 if (TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (exp)))
3130 high_positive = fold (build (RSHIFT_EXPR, type,
3131 convert (type, high_positive),
3132 convert (type, integer_one_node)));
3134 /* If the low bound is specified, "and" the range with the
3135 range for which the original unsigned value will be
3139 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3141 1, convert (type, integer_zero_node),
3145 in_p = (n_in_p == in_p);
3149 /* Otherwise, "or" the range with the range of the input
3150 that will be interpreted as negative. */
3151 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3153 1, convert (type, integer_zero_node),
3157 in_p = (in_p != n_in_p);
3162 low = n_low, high = n_high;
3172 /* If EXP is a constant, we can evaluate whether this is true or false. */
3173 if (TREE_CODE (exp) == INTEGER_CST)
3175 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
3177 && integer_onep (range_binop (LE_EXPR, integer_type_node,
3183 *pin_p = in_p, *plow = low, *phigh = high;
3187 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3188 type, TYPE, return an expression to test if EXP is in (or out of, depending
3189 on IN_P) the range. */
3192 build_range_check (tree type, tree exp, int in_p, tree low, tree high)
3194 tree etype = TREE_TYPE (exp);
3198 && (0 != (value = build_range_check (type, exp, 1, low, high))))
3199 return invert_truthvalue (value);
3201 if (low == 0 && high == 0)
3202 return convert (type, integer_one_node);
3205 return fold (build (LE_EXPR, type, exp, high));
3208 return fold (build (GE_EXPR, type, exp, low));
3210 if (operand_equal_p (low, high, 0))
3211 return fold (build (EQ_EXPR, type, exp, low));
3213 if (integer_zerop (low))
3215 if (! TREE_UNSIGNED (etype))
3217 etype = (*lang_hooks.types.unsigned_type) (etype);
3218 high = convert (etype, high);
3219 exp = convert (etype, exp);
3221 return build_range_check (type, exp, 1, 0, high);
3224 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
3225 if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST)
3227 unsigned HOST_WIDE_INT lo;
3231 prec = TYPE_PRECISION (etype);
3232 if (prec <= HOST_BITS_PER_WIDE_INT)
3235 lo = ((unsigned HOST_WIDE_INT) 1 << (prec - 1)) - 1;
3239 hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1;
3240 lo = (unsigned HOST_WIDE_INT) -1;
3243 if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo)
3245 if (TREE_UNSIGNED (etype))
3247 etype = (*lang_hooks.types.signed_type) (etype);
3248 exp = convert (etype, exp);
3250 return fold (build (GT_EXPR, type, exp,
3251 convert (etype, integer_zero_node)));
3255 if (0 != (value = const_binop (MINUS_EXPR, high, low, 0))
3256 && ! TREE_OVERFLOW (value))
3257 return build_range_check (type,
3258 fold (build (MINUS_EXPR, etype, exp, low)),
3259 1, convert (etype, integer_zero_node), value);
3264 /* Given two ranges, see if we can merge them into one. Return 1 if we
3265 can, 0 if we can't. Set the output range into the specified parameters. */
3268 merge_ranges (int *pin_p, tree *plow, tree *phigh, int in0_p, tree low0,
3269 tree high0, int in1_p, tree low1, tree high1)
3277 int lowequal = ((low0 == 0 && low1 == 0)
3278 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3279 low0, 0, low1, 0)));
3280 int highequal = ((high0 == 0 && high1 == 0)
3281 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3282 high0, 1, high1, 1)));
3284 /* Make range 0 be the range that starts first, or ends last if they
3285 start at the same value. Swap them if it isn't. */
3286 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
3289 && integer_onep (range_binop (GT_EXPR, integer_type_node,
3290 high1, 1, high0, 1))))
3292 temp = in0_p, in0_p = in1_p, in1_p = temp;
3293 tem = low0, low0 = low1, low1 = tem;
3294 tem = high0, high0 = high1, high1 = tem;
3297 /* Now flag two cases, whether the ranges are disjoint or whether the
3298 second range is totally subsumed in the first. Note that the tests
3299 below are simplified by the ones above. */
3300 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
3301 high0, 1, low1, 0));
3302 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
3303 high1, 1, high0, 1));
3305 /* We now have four cases, depending on whether we are including or
3306 excluding the two ranges. */
3309 /* If they don't overlap, the result is false. If the second range
3310 is a subset it is the result. Otherwise, the range is from the start
3311 of the second to the end of the first. */
3313 in_p = 0, low = high = 0;
3315 in_p = 1, low = low1, high = high1;
3317 in_p = 1, low = low1, high = high0;
3320 else if (in0_p && ! in1_p)
3322 /* If they don't overlap, the result is the first range. If they are
3323 equal, the result is false. If the second range is a subset of the
3324 first, and the ranges begin at the same place, we go from just after
3325 the end of the first range to the end of the second. If the second
3326 range is not a subset of the first, or if it is a subset and both
3327 ranges end at the same place, the range starts at the start of the
3328 first range and ends just before the second range.
3329 Otherwise, we can't describe this as a single range. */
3331 in_p = 1, low = low0, high = high0;
3332 else if (lowequal && highequal)
3333 in_p = 0, low = high = 0;
3334 else if (subset && lowequal)
3336 in_p = 1, high = high0;
3337 low = range_binop (PLUS_EXPR, NULL_TREE, high1, 0,
3338 integer_one_node, 0);
3340 else if (! subset || highequal)
3342 in_p = 1, low = low0;
3343 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
3344 integer_one_node, 0);
3350 else if (! in0_p && in1_p)
3352 /* If they don't overlap, the result is the second range. If the second
3353 is a subset of the first, the result is false. Otherwise,
3354 the range starts just after the first range and ends at the
3355 end of the second. */
3357 in_p = 1, low = low1, high = high1;
3358 else if (subset || highequal)
3359 in_p = 0, low = high = 0;
3362 in_p = 1, high = high1;
3363 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
3364 integer_one_node, 0);
3370 /* The case where we are excluding both ranges. Here the complex case
3371 is if they don't overlap. In that case, the only time we have a
3372 range is if they are adjacent. If the second is a subset of the
3373 first, the result is the first. Otherwise, the range to exclude
3374 starts at the beginning of the first range and ends at the end of the
3378 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
3379 range_binop (PLUS_EXPR, NULL_TREE,
3381 integer_one_node, 1),
3383 in_p = 0, low = low0, high = high1;
3388 in_p = 0, low = low0, high = high0;
3390 in_p = 0, low = low0, high = high1;
3393 *pin_p = in_p, *plow = low, *phigh = high;
3397 #ifndef RANGE_TEST_NON_SHORT_CIRCUIT
3398 #define RANGE_TEST_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
3401 /* EXP is some logical combination of boolean tests. See if we can
3402 merge it into some range test. Return the new tree if so. */
3405 fold_range_test (tree exp)
3407 int or_op = (TREE_CODE (exp) == TRUTH_ORIF_EXPR
3408 || TREE_CODE (exp) == TRUTH_OR_EXPR);
3409 int in0_p, in1_p, in_p;
3410 tree low0, low1, low, high0, high1, high;
3411 tree lhs = make_range (TREE_OPERAND (exp, 0), &in0_p, &low0, &high0);
3412 tree rhs = make_range (TREE_OPERAND (exp, 1), &in1_p, &low1, &high1);
3415 /* If this is an OR operation, invert both sides; we will invert
3416 again at the end. */
3418 in0_p = ! in0_p, in1_p = ! in1_p;
3420 /* If both expressions are the same, if we can merge the ranges, and we
3421 can build the range test, return it or it inverted. If one of the
3422 ranges is always true or always false, consider it to be the same
3423 expression as the other. */
3424 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
3425 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
3427 && 0 != (tem = (build_range_check (TREE_TYPE (exp),
3429 : rhs != 0 ? rhs : integer_zero_node,
3431 return or_op ? invert_truthvalue (tem) : tem;
3433 /* On machines where the branch cost is expensive, if this is a
3434 short-circuited branch and the underlying object on both sides
3435 is the same, make a non-short-circuit operation. */
3436 else if (RANGE_TEST_NON_SHORT_CIRCUIT
3437 && lhs != 0 && rhs != 0
3438 && (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3439 || TREE_CODE (exp) == TRUTH_ORIF_EXPR)
3440 && operand_equal_p (lhs, rhs, 0))
3442 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
3443 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
3444 which cases we can't do this. */
3445 if (simple_operand_p (lhs))
3446 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3447 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3448 TREE_TYPE (exp), TREE_OPERAND (exp, 0),
3449 TREE_OPERAND (exp, 1));
3451 else if ((*lang_hooks.decls.global_bindings_p) () == 0
3452 && ! CONTAINS_PLACEHOLDER_P (lhs))
3454 tree common = save_expr (lhs);
3456 if (0 != (lhs = build_range_check (TREE_TYPE (exp), common,
3457 or_op ? ! in0_p : in0_p,
3459 && (0 != (rhs = build_range_check (TREE_TYPE (exp), common,
3460 or_op ? ! in1_p : in1_p,
3462 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3463 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3464 TREE_TYPE (exp), lhs, rhs);
3471 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
3472 bit value. Arrange things so the extra bits will be set to zero if and
3473 only if C is signed-extended to its full width. If MASK is nonzero,
3474 it is an INTEGER_CST that should be AND'ed with the extra bits. */
3477 unextend (tree c, int p, int unsignedp, tree mask)
3479 tree type = TREE_TYPE (c);
3480 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
3483 if (p == modesize || unsignedp)
3486 /* We work by getting just the sign bit into the low-order bit, then
3487 into the high-order bit, then sign-extend. We then XOR that value
3489 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
3490 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
3492 /* We must use a signed type in order to get an arithmetic right shift.
3493 However, we must also avoid introducing accidental overflows, so that
3494 a subsequent call to integer_zerop will work. Hence we must
3495 do the type conversion here. At this point, the constant is either
3496 zero or one, and the conversion to a signed type can never overflow.
3497 We could get an overflow if this conversion is done anywhere else. */
3498 if (TREE_UNSIGNED (type))
3499 temp = convert ((*lang_hooks.types.signed_type) (type), temp);
3501 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
3502 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
3504 temp = const_binop (BIT_AND_EXPR, temp, convert (TREE_TYPE (c), mask), 0);
3505 /* If necessary, convert the type back to match the type of C. */
3506 if (TREE_UNSIGNED (type))
3507 temp = convert (type, temp);
3509 return convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
3512 /* Find ways of folding logical expressions of LHS and RHS:
3513 Try to merge two comparisons to the same innermost item.
3514 Look for range tests like "ch >= '0' && ch <= '9'".
3515 Look for combinations of simple terms on machines with expensive branches
3516 and evaluate the RHS unconditionally.
3518 For example, if we have p->a == 2 && p->b == 4 and we can make an
3519 object large enough to span both A and B, we can do this with a comparison
3520 against the object ANDed with the a mask.
3522 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
3523 operations to do this with one comparison.
3525 We check for both normal comparisons and the BIT_AND_EXPRs made this by
3526 function and the one above.
3528 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
3529 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
3531 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
3534 We return the simplified tree or 0 if no optimization is possible. */
3537 fold_truthop (enum tree_code code, tree truth_type, tree lhs, tree rhs)
3539 /* If this is the "or" of two comparisons, we can do something if
3540 the comparisons are NE_EXPR. If this is the "and", we can do something
3541 if the comparisons are EQ_EXPR. I.e.,
3542 (a->b == 2 && a->c == 4) can become (a->new == NEW).
3544 WANTED_CODE is this operation code. For single bit fields, we can
3545 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
3546 comparison for one-bit fields. */
3548 enum tree_code wanted_code;
3549 enum tree_code lcode, rcode;
3550 tree ll_arg, lr_arg, rl_arg, rr_arg;
3551 tree ll_inner, lr_inner, rl_inner, rr_inner;
3552 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
3553 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
3554 HOST_WIDE_INT xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
3555 HOST_WIDE_INT lnbitsize, lnbitpos, rnbitsize, rnbitpos;
3556 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
3557 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
3558 enum machine_mode lnmode, rnmode;
3559 tree ll_mask, lr_mask, rl_mask, rr_mask;
3560 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
3561 tree l_const, r_const;
3562 tree lntype, rntype, result;
3563 int first_bit, end_bit;
3566 /* Start by getting the comparison codes. Fail if anything is volatile.
3567 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
3568 it were surrounded with a NE_EXPR. */
3570 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
3573 lcode = TREE_CODE (lhs);
3574 rcode = TREE_CODE (rhs);
3576 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
3577 lcode = NE_EXPR, lhs = build (NE_EXPR, truth_type, lhs, integer_zero_node);
3579 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
3580 rcode = NE_EXPR, rhs = build (NE_EXPR, truth_type, rhs, integer_zero_node);
3582 if (TREE_CODE_CLASS (lcode) != '<' || TREE_CODE_CLASS (rcode) != '<')
3585 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
3586 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
3588 ll_arg = TREE_OPERAND (lhs, 0);
3589 lr_arg = TREE_OPERAND (lhs, 1);
3590 rl_arg = TREE_OPERAND (rhs, 0);
3591 rr_arg = TREE_OPERAND (rhs, 1);
3593 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
3594 if (simple_operand_p (ll_arg)
3595 && simple_operand_p (lr_arg)
3596 && !FLOAT_TYPE_P (TREE_TYPE (ll_arg)))
3600 if (operand_equal_p (ll_arg, rl_arg, 0)
3601 && operand_equal_p (lr_arg, rr_arg, 0))
3603 int lcompcode, rcompcode;
3605 lcompcode = comparison_to_compcode (lcode);
3606 rcompcode = comparison_to_compcode (rcode);
3607 compcode = (code == TRUTH_AND_EXPR)
3608 ? lcompcode & rcompcode
3609 : lcompcode | rcompcode;
3611 else if (operand_equal_p (ll_arg, rr_arg, 0)
3612 && operand_equal_p (lr_arg, rl_arg, 0))
3614 int lcompcode, rcompcode;
3616 rcode = swap_tree_comparison (rcode);
3617 lcompcode = comparison_to_compcode (lcode);
3618 rcompcode = comparison_to_compcode (rcode);
3619 compcode = (code == TRUTH_AND_EXPR)
3620 ? lcompcode & rcompcode
3621 : lcompcode | rcompcode;
3626 if (compcode == COMPCODE_TRUE)
3627 return convert (truth_type, integer_one_node);
3628 else if (compcode == COMPCODE_FALSE)
3629 return convert (truth_type, integer_zero_node);
3630 else if (compcode != -1)
3631 return build (compcode_to_comparison (compcode),
3632 truth_type, ll_arg, lr_arg);
3635 /* If the RHS can be evaluated unconditionally and its operands are
3636 simple, it wins to evaluate the RHS unconditionally on machines
3637 with expensive branches. In this case, this isn't a comparison
3638 that can be merged. Avoid doing this if the RHS is a floating-point
3639 comparison since those can trap. */
3641 if (BRANCH_COST >= 2
3642 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
3643 && simple_operand_p (rl_arg)
3644 && simple_operand_p (rr_arg))
3646 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
3647 if (code == TRUTH_OR_EXPR
3648 && lcode == NE_EXPR && integer_zerop (lr_arg)
3649 && rcode == NE_EXPR && integer_zerop (rr_arg)
3650 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
3651 return build (NE_EXPR, truth_type,
3652 build (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
3656 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
3657 if (code == TRUTH_AND_EXPR
3658 && lcode == EQ_EXPR && integer_zerop (lr_arg)
3659 && rcode == EQ_EXPR && integer_zerop (rr_arg)
3660 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
3661 return build (EQ_EXPR, truth_type,
3662 build (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
3666 return build (code, truth_type, lhs, rhs);
3669 /* See if the comparisons can be merged. Then get all the parameters for
3672 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
3673 || (rcode != EQ_EXPR && rcode != NE_EXPR))
3677 ll_inner = decode_field_reference (ll_arg,
3678 &ll_bitsize, &ll_bitpos, &ll_mode,
3679 &ll_unsignedp, &volatilep, &ll_mask,
3681 lr_inner = decode_field_reference (lr_arg,
3682 &lr_bitsize, &lr_bitpos, &lr_mode,
3683 &lr_unsignedp, &volatilep, &lr_mask,
3685 rl_inner = decode_field_reference (rl_arg,
3686 &rl_bitsize, &rl_bitpos, &rl_mode,
3687 &rl_unsignedp, &volatilep, &rl_mask,
3689 rr_inner = decode_field_reference (rr_arg,
3690 &rr_bitsize, &rr_bitpos, &rr_mode,
3691 &rr_unsignedp, &volatilep, &rr_mask,
3694 /* It must be true that the inner operation on the lhs of each
3695 comparison must be the same if we are to be able to do anything.
3696 Then see if we have constants. If not, the same must be true for
3698 if (volatilep || ll_inner == 0 || rl_inner == 0
3699 || ! operand_equal_p (ll_inner, rl_inner, 0))
3702 if (TREE_CODE (lr_arg) == INTEGER_CST
3703 && TREE_CODE (rr_arg) == INTEGER_CST)
3704 l_const = lr_arg, r_const = rr_arg;
3705 else if (lr_inner == 0 || rr_inner == 0
3706 || ! operand_equal_p (lr_inner, rr_inner, 0))
3709 l_const = r_const = 0;
3711 /* If either comparison code is not correct for our logical operation,
3712 fail. However, we can convert a one-bit comparison against zero into
3713 the opposite comparison against that bit being set in the field. */
3715 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
3716 if (lcode != wanted_code)
3718 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
3720 /* Make the left operand unsigned, since we are only interested
3721 in the value of one bit. Otherwise we are doing the wrong
3730 /* This is analogous to the code for l_const above. */
3731 if (rcode != wanted_code)
3733 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
3742 /* After this point all optimizations will generate bit-field
3743 references, which we might not want. */
3744 if (! (*lang_hooks.can_use_bit_fields_p) ())
3747 /* See if we can find a mode that contains both fields being compared on
3748 the left. If we can't, fail. Otherwise, update all constants and masks
3749 to be relative to a field of that size. */
3750 first_bit = MIN (ll_bitpos, rl_bitpos);
3751 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
3752 lnmode = get_best_mode (end_bit - first_bit, first_bit,
3753 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
3755 if (lnmode == VOIDmode)
3758 lnbitsize = GET_MODE_BITSIZE (lnmode);
3759 lnbitpos = first_bit & ~ (lnbitsize - 1);
3760 lntype = (*lang_hooks.types.type_for_size) (lnbitsize, 1);
3761 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
3763 if (BYTES_BIG_ENDIAN)
3765 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
3766 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
3769 ll_mask = const_binop (LSHIFT_EXPR, convert (lntype, ll_mask),
3770 size_int (xll_bitpos), 0);
3771 rl_mask = const_binop (LSHIFT_EXPR, convert (lntype, rl_mask),
3772 size_int (xrl_bitpos), 0);
3776 l_const = convert (lntype, l_const);
3777 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
3778 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
3779 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
3780 fold (build1 (BIT_NOT_EXPR,
3784 warning ("comparison is always %d", wanted_code == NE_EXPR);
3786 return convert (truth_type,
3787 wanted_code == NE_EXPR
3788 ? integer_one_node : integer_zero_node);
3793 r_const = convert (lntype, r_const);
3794 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
3795 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
3796 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
3797 fold (build1 (BIT_NOT_EXPR,
3801 warning ("comparison is always %d", wanted_code == NE_EXPR);
3803 return convert (truth_type,
3804 wanted_code == NE_EXPR
3805 ? integer_one_node : integer_zero_node);
3809 /* If the right sides are not constant, do the same for it. Also,
3810 disallow this optimization if a size or signedness mismatch occurs
3811 between the left and right sides. */
3814 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
3815 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
3816 /* Make sure the two fields on the right
3817 correspond to the left without being swapped. */
3818 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
3821 first_bit = MIN (lr_bitpos, rr_bitpos);
3822 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
3823 rnmode = get_best_mode (end_bit - first_bit, first_bit,
3824 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
3826 if (rnmode == VOIDmode)
3829 rnbitsize = GET_MODE_BITSIZE (rnmode);
3830 rnbitpos = first_bit & ~ (rnbitsize - 1);
3831 rntype = (*lang_hooks.types.type_for_size) (rnbitsize, 1);
3832 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
3834 if (BYTES_BIG_ENDIAN)
3836 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
3837 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
3840 lr_mask = const_binop (LSHIFT_EXPR, convert (rntype, lr_mask),
3841 size_int (xlr_bitpos), 0);
3842 rr_mask = const_binop (LSHIFT_EXPR, convert (rntype, rr_mask),
3843 size_int (xrr_bitpos), 0);
3845 /* Make a mask that corresponds to both fields being compared.
3846 Do this for both items being compared. If the operands are the
3847 same size and the bits being compared are in the same position
3848 then we can do this by masking both and comparing the masked
3850 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
3851 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
3852 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
3854 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
3855 ll_unsignedp || rl_unsignedp);
3856 if (! all_ones_mask_p (ll_mask, lnbitsize))
3857 lhs = build (BIT_AND_EXPR, lntype, lhs, ll_mask);
3859 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
3860 lr_unsignedp || rr_unsignedp);
3861 if (! all_ones_mask_p (lr_mask, rnbitsize))
3862 rhs = build (BIT_AND_EXPR, rntype, rhs, lr_mask);
3864 return build (wanted_code, truth_type, lhs, rhs);
3867 /* There is still another way we can do something: If both pairs of
3868 fields being compared are adjacent, we may be able to make a wider
3869 field containing them both.
3871 Note that we still must mask the lhs/rhs expressions. Furthermore,
3872 the mask must be shifted to account for the shift done by
3873 make_bit_field_ref. */
3874 if ((ll_bitsize + ll_bitpos == rl_bitpos
3875 && lr_bitsize + lr_bitpos == rr_bitpos)
3876 || (ll_bitpos == rl_bitpos + rl_bitsize
3877 && lr_bitpos == rr_bitpos + rr_bitsize))
3881 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
3882 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
3883 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
3884 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
3886 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
3887 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
3888 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
3889 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
3891 /* Convert to the smaller type before masking out unwanted bits. */
3893 if (lntype != rntype)
3895 if (lnbitsize > rnbitsize)
3897 lhs = convert (rntype, lhs);
3898 ll_mask = convert (rntype, ll_mask);
3901 else if (lnbitsize < rnbitsize)
3903 rhs = convert (lntype, rhs);
3904 lr_mask = convert (lntype, lr_mask);
3909 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
3910 lhs = build (BIT_AND_EXPR, type, lhs, ll_mask);
3912 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
3913 rhs = build (BIT_AND_EXPR, type, rhs, lr_mask);
3915 return build (wanted_code, truth_type, lhs, rhs);
3921 /* Handle the case of comparisons with constants. If there is something in
3922 common between the masks, those bits of the constants must be the same.
3923 If not, the condition is always false. Test for this to avoid generating
3924 incorrect code below. */
3925 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
3926 if (! integer_zerop (result)
3927 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
3928 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
3930 if (wanted_code == NE_EXPR)
3932 warning ("`or' of unmatched not-equal tests is always 1");
3933 return convert (truth_type, integer_one_node);
3937 warning ("`and' of mutually exclusive equal-tests is always 0");
3938 return convert (truth_type, integer_zero_node);
3942 /* Construct the expression we will return. First get the component
3943 reference we will make. Unless the mask is all ones the width of
3944 that field, perform the mask operation. Then compare with the
3946 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
3947 ll_unsignedp || rl_unsignedp);
3949 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
3950 if (! all_ones_mask_p (ll_mask, lnbitsize))
3951 result = build (BIT_AND_EXPR, lntype, result, ll_mask);
3953 return build (wanted_code, truth_type, result,
3954 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
3957 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
3961 optimize_minmax_comparison (tree t)
3963 tree type = TREE_TYPE (t);
3964 tree arg0 = TREE_OPERAND (t, 0);
3965 enum tree_code op_code;
3966 tree comp_const = TREE_OPERAND (t, 1);
3968 int consts_equal, consts_lt;
3971 STRIP_SIGN_NOPS (arg0);
3973 op_code = TREE_CODE (arg0);
3974 minmax_const = TREE_OPERAND (arg0, 1);
3975 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
3976 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
3977 inner = TREE_OPERAND (arg0, 0);
3979 /* If something does not permit us to optimize, return the original tree. */
3980 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
3981 || TREE_CODE (comp_const) != INTEGER_CST
3982 || TREE_CONSTANT_OVERFLOW (comp_const)
3983 || TREE_CODE (minmax_const) != INTEGER_CST
3984 || TREE_CONSTANT_OVERFLOW (minmax_const))
3987 /* Now handle all the various comparison codes. We only handle EQ_EXPR
3988 and GT_EXPR, doing the rest with recursive calls using logical
3990 switch (TREE_CODE (t))
3992 case NE_EXPR: case LT_EXPR: case LE_EXPR:
3994 invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t)));
3998 fold (build (TRUTH_ORIF_EXPR, type,
3999 optimize_minmax_comparison
4000 (build (EQ_EXPR, type, arg0, comp_const)),
4001 optimize_minmax_comparison
4002 (build (GT_EXPR, type, arg0, comp_const))));
4005 if (op_code == MAX_EXPR && consts_equal)
4006 /* MAX (X, 0) == 0 -> X <= 0 */
4007 return fold (build (LE_EXPR, type, inner, comp_const));
4009 else if (op_code == MAX_EXPR && consts_lt)
4010 /* MAX (X, 0) == 5 -> X == 5 */
4011 return fold (build (EQ_EXPR, type, inner, comp_const));
4013 else if (op_code == MAX_EXPR)
4014 /* MAX (X, 0) == -1 -> false */
4015 return omit_one_operand (type, integer_zero_node, inner);
4017 else if (consts_equal)
4018 /* MIN (X, 0) == 0 -> X >= 0 */
4019 return fold (build (GE_EXPR, type, inner, comp_const));
4022 /* MIN (X, 0) == 5 -> false */
4023 return omit_one_operand (type, integer_zero_node, inner);
4026 /* MIN (X, 0) == -1 -> X == -1 */
4027 return fold (build (EQ_EXPR, type, inner, comp_const));
4030 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
4031 /* MAX (X, 0) > 0 -> X > 0
4032 MAX (X, 0) > 5 -> X > 5 */
4033 return fold (build (GT_EXPR, type, inner, comp_const));
4035 else if (op_code == MAX_EXPR)
4036 /* MAX (X, 0) > -1 -> true */
4037 return omit_one_operand (type, integer_one_node, inner);
4039 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
4040 /* MIN (X, 0) > 0 -> false
4041 MIN (X, 0) > 5 -> false */
4042 return omit_one_operand (type, integer_zero_node, inner);
4045 /* MIN (X, 0) > -1 -> X > -1 */
4046 return fold (build (GT_EXPR, type, inner, comp_const));
4053 /* T is an integer expression that is being multiplied, divided, or taken a
4054 modulus (CODE says which and what kind of divide or modulus) by a
4055 constant C. See if we can eliminate that operation by folding it with
4056 other operations already in T. WIDE_TYPE, if non-null, is a type that
4057 should be used for the computation if wider than our type.
4059 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
4060 (X * 2) + (Y * 4). We must, however, be assured that either the original
4061 expression would not overflow or that overflow is undefined for the type
4062 in the language in question.
4064 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
4065 the machine has a multiply-accumulate insn or that this is part of an
4066 addressing calculation.
4068 If we return a non-null expression, it is an equivalent form of the
4069 original computation, but need not be in the original type. */
4072 extract_muldiv (tree t, tree c, enum tree_code code, tree wide_type)
4074 /* To avoid exponential search depth, refuse to allow recursion past
4075 three levels. Beyond that (1) it's highly unlikely that we'll find
4076 something interesting and (2) we've probably processed it before
4077 when we built the inner expression. */
4086 ret = extract_muldiv_1 (t, c, code, wide_type);
4093 extract_muldiv_1 (tree t, tree c, enum tree_code code, tree wide_type)
4095 tree type = TREE_TYPE (t);
4096 enum tree_code tcode = TREE_CODE (t);
4097 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
4098 > GET_MODE_SIZE (TYPE_MODE (type)))
4099 ? wide_type : type);
4101 int same_p = tcode == code;
4102 tree op0 = NULL_TREE, op1 = NULL_TREE;
4104 /* Don't deal with constants of zero here; they confuse the code below. */
4105 if (integer_zerop (c))
4108 if (TREE_CODE_CLASS (tcode) == '1')
4109 op0 = TREE_OPERAND (t, 0);
4111 if (TREE_CODE_CLASS (tcode) == '2')
4112 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
4114 /* Note that we need not handle conditional operations here since fold
4115 already handles those cases. So just do arithmetic here. */
4119 /* For a constant, we can always simplify if we are a multiply
4120 or (for divide and modulus) if it is a multiple of our constant. */
4121 if (code == MULT_EXPR
4122 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
4123 return const_binop (code, convert (ctype, t), convert (ctype, c), 0);
4126 case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
4127 /* If op0 is an expression ... */
4128 if ((TREE_CODE_CLASS (TREE_CODE (op0)) == '<'
4129 || TREE_CODE_CLASS (TREE_CODE (op0)) == '1'
4130 || TREE_CODE_CLASS (TREE_CODE (op0)) == '2'
4131 || TREE_CODE_CLASS (TREE_CODE (op0)) == 'e')
4132 /* ... and is unsigned, and its type is smaller than ctype,
4133 then we cannot pass through as widening. */
4134 && ((TREE_UNSIGNED (TREE_TYPE (op0))
4135 && ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
4136 && TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
4137 && (GET_MODE_SIZE (TYPE_MODE (ctype))
4138 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
4139 /* ... or its type is larger than ctype,
4140 then we cannot pass through this truncation. */
4141 || (GET_MODE_SIZE (TYPE_MODE (ctype))
4142 < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0))))
4143 /* ... or signedness changes for division or modulus,
4144 then we cannot pass through this conversion. */
4145 || (code != MULT_EXPR
4146 && (TREE_UNSIGNED (ctype)
4147 != TREE_UNSIGNED (TREE_TYPE (op0))))))
4150 /* Pass the constant down and see if we can make a simplification. If
4151 we can, replace this expression with the inner simplification for
4152 possible later conversion to our or some other type. */
4153 if ((t2 = convert (TREE_TYPE (op0), c)) != 0
4154 && TREE_CODE (t2) == INTEGER_CST
4155 && ! TREE_CONSTANT_OVERFLOW (t2)
4156 && (0 != (t1 = extract_muldiv (op0, t2, code,
4158 ? ctype : NULL_TREE))))
4162 case NEGATE_EXPR: case ABS_EXPR:
4163 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4164 return fold (build1 (tcode, ctype, convert (ctype, t1)));
4167 case MIN_EXPR: case MAX_EXPR:
4168 /* If widening the type changes the signedness, then we can't perform
4169 this optimization as that changes the result. */
4170 if (TREE_UNSIGNED (ctype) != TREE_UNSIGNED (type))
4173 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
4174 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0
4175 && (t2 = extract_muldiv (op1, c, code, wide_type)) != 0)
4177 if (tree_int_cst_sgn (c) < 0)
4178 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
4180 return fold (build (tcode, ctype, convert (ctype, t1),
4181 convert (ctype, t2)));
4185 case WITH_RECORD_EXPR:
4186 if ((t1 = extract_muldiv (TREE_OPERAND (t, 0), c, code, wide_type)) != 0)
4187 return build (WITH_RECORD_EXPR, TREE_TYPE (t1), t1,
4188 TREE_OPERAND (t, 1));
4191 case LSHIFT_EXPR: case RSHIFT_EXPR:
4192 /* If the second operand is constant, this is a multiplication
4193 or floor division, by a power of two, so we can treat it that
4194 way unless the multiplier or divisor overflows. */
4195 if (TREE_CODE (op1) == INTEGER_CST
4196 /* const_binop may not detect overflow correctly,
4197 so check for it explicitly here. */
4198 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
4199 && TREE_INT_CST_HIGH (op1) == 0
4200 && 0 != (t1 = convert (ctype,
4201 const_binop (LSHIFT_EXPR, size_one_node,
4203 && ! TREE_OVERFLOW (t1))
4204 return extract_muldiv (build (tcode == LSHIFT_EXPR
4205 ? MULT_EXPR : FLOOR_DIV_EXPR,
4206 ctype, convert (ctype, op0), t1),
4207 c, code, wide_type);
4210 case PLUS_EXPR: case MINUS_EXPR:
4211 /* See if we can eliminate the operation on both sides. If we can, we
4212 can return a new PLUS or MINUS. If we can't, the only remaining
4213 cases where we can do anything are if the second operand is a
4215 t1 = extract_muldiv (op0, c, code, wide_type);
4216 t2 = extract_muldiv (op1, c, code, wide_type);
4217 if (t1 != 0 && t2 != 0
4218 && (code == MULT_EXPR
4219 /* If not multiplication, we can only do this if both operands
4220 are divisible by c. */
4221 || (multiple_of_p (ctype, op0, c)
4222 && multiple_of_p (ctype, op1, c))))
4223 return fold (build (tcode, ctype, convert (ctype, t1),
4224 convert (ctype, t2)));
4226 /* If this was a subtraction, negate OP1 and set it to be an addition.
4227 This simplifies the logic below. */
4228 if (tcode == MINUS_EXPR)
4229 tcode = PLUS_EXPR, op1 = negate_expr (op1);
4231 if (TREE_CODE (op1) != INTEGER_CST)
4234 /* If either OP1 or C are negative, this optimization is not safe for
4235 some of the division and remainder types while for others we need
4236 to change the code. */
4237 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
4239 if (code == CEIL_DIV_EXPR)
4240 code = FLOOR_DIV_EXPR;
4241 else if (code == FLOOR_DIV_EXPR)
4242 code = CEIL_DIV_EXPR;
4243 else if (code != MULT_EXPR
4244 && code != CEIL_MOD_EXPR && code != FLOOR_MOD_EXPR)
4248 /* If it's a multiply or a division/modulus operation of a multiple
4249 of our constant, do the operation and verify it doesn't overflow. */
4250 if (code == MULT_EXPR
4251 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4253 op1 = const_binop (code, convert (ctype, op1), convert (ctype, c), 0);
4254 if (op1 == 0 || TREE_OVERFLOW (op1))
4260 /* If we have an unsigned type is not a sizetype, we cannot widen
4261 the operation since it will change the result if the original
4262 computation overflowed. */
4263 if (TREE_UNSIGNED (ctype)
4264 && ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
4268 /* If we were able to eliminate our operation from the first side,
4269 apply our operation to the second side and reform the PLUS. */
4270 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
4271 return fold (build (tcode, ctype, convert (ctype, t1), op1));
4273 /* The last case is if we are a multiply. In that case, we can
4274 apply the distributive law to commute the multiply and addition
4275 if the multiplication of the constants doesn't overflow. */
4276 if (code == MULT_EXPR)
4277 return fold (build (tcode, ctype, fold (build (code, ctype,
4278 convert (ctype, op0),
4279 convert (ctype, c))),
4285 /* We have a special case here if we are doing something like
4286 (C * 8) % 4 since we know that's zero. */
4287 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
4288 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
4289 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
4290 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4291 return omit_one_operand (type, integer_zero_node, op0);
4293 /* ... fall through ... */
4295 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
4296 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
4297 /* If we can extract our operation from the LHS, do so and return a
4298 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
4299 do something only if the second operand is a constant. */
4301 && (t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4302 return fold (build (tcode, ctype, convert (ctype, t1),
4303 convert (ctype, op1)));
4304 else if (tcode == MULT_EXPR && code == MULT_EXPR
4305 && (t1 = extract_muldiv (op1, c, code, wide_type)) != 0)
4306 return fold (build (tcode, ctype, convert (ctype, op0),
4307 convert (ctype, t1)));
4308 else if (TREE_CODE (op1) != INTEGER_CST)
4311 /* If these are the same operation types, we can associate them
4312 assuming no overflow. */
4314 && 0 != (t1 = const_binop (MULT_EXPR, convert (ctype, op1),
4315 convert (ctype, c), 0))
4316 && ! TREE_OVERFLOW (t1))
4317 return fold (build (tcode, ctype, convert (ctype, op0), t1));
4319 /* If these operations "cancel" each other, we have the main
4320 optimizations of this pass, which occur when either constant is a
4321 multiple of the other, in which case we replace this with either an
4322 operation or CODE or TCODE.
4324 If we have an unsigned type that is not a sizetype, we cannot do
4325 this since it will change the result if the original computation
4327 if ((! TREE_UNSIGNED (ctype)
4328 || (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
4330 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
4331 || (tcode == MULT_EXPR
4332 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
4333 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR)))
4335 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4336 return fold (build (tcode, ctype, convert (ctype, op0),
4338 const_binop (TRUNC_DIV_EXPR,
4340 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
4341 return fold (build (code, ctype, convert (ctype, op0),
4343 const_binop (TRUNC_DIV_EXPR,
4355 /* If T contains a COMPOUND_EXPR which was inserted merely to evaluate
4356 S, a SAVE_EXPR, return the expression actually being evaluated. Note
4357 that we may sometimes modify the tree. */
4360 strip_compound_expr (tree t, tree s)
4362 enum tree_code code = TREE_CODE (t);
4364 /* See if this is the COMPOUND_EXPR we want to eliminate. */
4365 if (code == COMPOUND_EXPR && TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR
4366 && TREE_OPERAND (TREE_OPERAND (t, 0), 0) == s)
4367 return TREE_OPERAND (t, 1);
4369 /* See if this is a COND_EXPR or a simple arithmetic operator. We
4370 don't bother handling any other types. */
4371 else if (code == COND_EXPR)
4373 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4374 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4375 TREE_OPERAND (t, 2) = strip_compound_expr (TREE_OPERAND (t, 2), s);
4377 else if (TREE_CODE_CLASS (code) == '1')
4378 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4379 else if (TREE_CODE_CLASS (code) == '<'
4380 || TREE_CODE_CLASS (code) == '2')
4382 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4383 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4389 /* Return a node which has the indicated constant VALUE (either 0 or
4390 1), and is of the indicated TYPE. */
4393 constant_boolean_node (int value, tree type)
4395 if (type == integer_type_node)
4396 return value ? integer_one_node : integer_zero_node;
4397 else if (TREE_CODE (type) == BOOLEAN_TYPE)
4398 return (*lang_hooks.truthvalue_conversion) (value ? integer_one_node :
4402 tree t = build_int_2 (value, 0);
4404 TREE_TYPE (t) = type;
4409 /* Utility function for the following routine, to see how complex a nesting of
4410 COND_EXPRs can be. EXPR is the expression and LIMIT is a count beyond which
4411 we don't care (to avoid spending too much time on complex expressions.). */
4414 count_cond (tree expr, int lim)
4418 if (TREE_CODE (expr) != COND_EXPR)
4423 ctrue = count_cond (TREE_OPERAND (expr, 1), lim - 1);
4424 cfalse = count_cond (TREE_OPERAND (expr, 2), lim - 1 - ctrue);
4425 return MIN (lim, 1 + ctrue + cfalse);
4428 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
4429 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
4430 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
4431 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
4432 COND is the first argument to CODE; otherwise (as in the example
4433 given here), it is the second argument. TYPE is the type of the
4434 original expression. */
4437 fold_binary_op_with_conditional_arg (enum tree_code code, tree type,
4438 tree cond, tree arg, int cond_first_p)
4440 tree test, true_value, false_value;
4441 tree lhs = NULL_TREE;
4442 tree rhs = NULL_TREE;
4443 /* In the end, we'll produce a COND_EXPR. Both arms of the
4444 conditional expression will be binary operations. The left-hand
4445 side of the expression to be executed if the condition is true
4446 will be pointed to by TRUE_LHS. Similarly, the right-hand side
4447 of the expression to be executed if the condition is true will be
4448 pointed to by TRUE_RHS. FALSE_LHS and FALSE_RHS are analogous --
4449 but apply to the expression to be executed if the conditional is
4455 /* These are the codes to use for the left-hand side and right-hand
4456 side of the COND_EXPR. Normally, they are the same as CODE. */
4457 enum tree_code lhs_code = code;
4458 enum tree_code rhs_code = code;
4459 /* And these are the types of the expressions. */
4460 tree lhs_type = type;
4461 tree rhs_type = type;
4466 true_rhs = false_rhs = &arg;
4467 true_lhs = &true_value;
4468 false_lhs = &false_value;
4472 true_lhs = false_lhs = &arg;
4473 true_rhs = &true_value;
4474 false_rhs = &false_value;
4477 if (TREE_CODE (cond) == COND_EXPR)
4479 test = TREE_OPERAND (cond, 0);
4480 true_value = TREE_OPERAND (cond, 1);
4481 false_value = TREE_OPERAND (cond, 2);
4482 /* If this operand throws an expression, then it does not make
4483 sense to try to perform a logical or arithmetic operation
4484 involving it. Instead of building `a + throw 3' for example,
4485 we simply build `a, throw 3'. */
4486 if (VOID_TYPE_P (TREE_TYPE (true_value)))
4490 lhs_code = COMPOUND_EXPR;
4491 lhs_type = void_type_node;
4496 if (VOID_TYPE_P (TREE_TYPE (false_value)))
4500 rhs_code = COMPOUND_EXPR;
4501 rhs_type = void_type_node;
4509 tree testtype = TREE_TYPE (cond);
4511 true_value = convert (testtype, integer_one_node);
4512 false_value = convert (testtype, integer_zero_node);
4515 /* If ARG is complex we want to make sure we only evaluate it once. Though
4516 this is only required if it is volatile, it might be more efficient even
4517 if it is not. However, if we succeed in folding one part to a constant,
4518 we do not need to make this SAVE_EXPR. Since we do this optimization
4519 primarily to see if we do end up with constant and this SAVE_EXPR
4520 interferes with later optimizations, suppressing it when we can is
4523 If we are not in a function, we can't make a SAVE_EXPR, so don't try to
4524 do so. Don't try to see if the result is a constant if an arm is a
4525 COND_EXPR since we get exponential behavior in that case. */
4527 if (saved_expr_p (arg))
4529 else if (lhs == 0 && rhs == 0
4530 && !TREE_CONSTANT (arg)
4531 && (*lang_hooks.decls.global_bindings_p) () == 0
4532 && ((TREE_CODE (arg) != VAR_DECL && TREE_CODE (arg) != PARM_DECL)
4533 || TREE_SIDE_EFFECTS (arg)))
4535 if (TREE_CODE (true_value) != COND_EXPR)
4536 lhs = fold (build (lhs_code, lhs_type, *true_lhs, *true_rhs));
4538 if (TREE_CODE (false_value) != COND_EXPR)
4539 rhs = fold (build (rhs_code, rhs_type, *false_lhs, *false_rhs));
4541 if ((lhs == 0 || ! TREE_CONSTANT (lhs))
4542 && (rhs == 0 || !TREE_CONSTANT (rhs)))
4544 arg = save_expr (arg);
4551 lhs = fold (build (lhs_code, lhs_type, *true_lhs, *true_rhs));
4553 rhs = fold (build (rhs_code, rhs_type, *false_lhs, *false_rhs));
4555 test = fold (build (COND_EXPR, type, test, lhs, rhs));
4558 return build (COMPOUND_EXPR, type,
4559 convert (void_type_node, arg),
4560 strip_compound_expr (test, arg));
4562 return convert (type, test);
4566 /* Subroutine of fold() that checks for the addition of +/- 0.0.
4568 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
4569 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
4570 ADDEND is the same as X.
4572 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
4573 and finite. The problematic cases are when X is zero, and its mode
4574 has signed zeros. In the case of rounding towards -infinity,
4575 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
4576 modes, X + 0 is not the same as X because -0 + 0 is 0. */
4579 fold_real_zero_addition_p (tree type, tree addend, int negate)
4581 if (!real_zerop (addend))
4584 /* Don't allow the fold with -fsignaling-nans. */
4585 if (HONOR_SNANS (TYPE_MODE (type)))
4588 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
4589 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
4592 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
4593 if (TREE_CODE (addend) == REAL_CST
4594 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
4597 /* The mode has signed zeros, and we have to honor their sign.
4598 In this situation, there is only one case we can return true for.
4599 X - 0 is the same as X unless rounding towards -infinity is
4601 return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
4604 /* Subroutine of fold() that checks comparisons of built-in math
4605 functions against real constants.
4607 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
4608 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
4609 is the type of the result and ARG0 and ARG1 are the operands of the
4610 comparison. ARG1 must be a TREE_REAL_CST.
4612 The function returns the constant folded tree if a simplification
4613 can be made, and NULL_TREE otherwise. */
4616 fold_mathfn_compare (enum built_in_function fcode, enum tree_code code,
4617 tree type, tree arg0, tree arg1)
4621 if (fcode == BUILT_IN_SQRT
4622 || fcode == BUILT_IN_SQRTF
4623 || fcode == BUILT_IN_SQRTL)
4625 tree arg = TREE_VALUE (TREE_OPERAND (arg0, 1));
4626 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg0));
4628 c = TREE_REAL_CST (arg1);
4629 if (REAL_VALUE_NEGATIVE (c))
4631 /* sqrt(x) < y is always false, if y is negative. */
4632 if (code == EQ_EXPR || code == LT_EXPR || code == LE_EXPR)
4633 return omit_one_operand (type,
4634 convert (type, integer_zero_node),
4637 /* sqrt(x) > y is always true, if y is negative and we
4638 don't care about NaNs, i.e. negative values of x. */
4639 if (code == NE_EXPR || !HONOR_NANS (mode))
4640 return omit_one_operand (type,
4641 convert (type, integer_one_node),
4644 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
4645 return fold (build (GE_EXPR, type, arg,
4646 build_real (TREE_TYPE (arg), dconst0)));
4648 else if (code == GT_EXPR || code == GE_EXPR)
4652 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
4653 real_convert (&c2, mode, &c2);
4655 if (REAL_VALUE_ISINF (c2))
4657 /* sqrt(x) > y is x == +Inf, when y is very large. */
4658 if (HONOR_INFINITIES (mode))
4659 return fold (build (EQ_EXPR, type, arg,
4660 build_real (TREE_TYPE (arg), c2)));
4662 /* sqrt(x) > y is always false, when y is very large
4663 and we don't care about infinities. */
4664 return omit_one_operand (type,
4665 convert (type, integer_zero_node),
4669 /* sqrt(x) > c is the same as x > c*c. */
4670 return fold (build (code, type, arg,
4671 build_real (TREE_TYPE (arg), c2)));
4673 else if (code == LT_EXPR || code == LE_EXPR)
4677 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
4678 real_convert (&c2, mode, &c2);
4680 if (REAL_VALUE_ISINF (c2))
4682 /* sqrt(x) < y is always true, when y is a very large
4683 value and we don't care about NaNs or Infinities. */
4684 if (! HONOR_NANS (mode) && ! HONOR_INFINITIES (mode))
4685 return omit_one_operand (type,
4686 convert (type, integer_one_node),
4689 /* sqrt(x) < y is x != +Inf when y is very large and we
4690 don't care about NaNs. */
4691 if (! HONOR_NANS (mode))
4692 return fold (build (NE_EXPR, type, arg,
4693 build_real (TREE_TYPE (arg), c2)));
4695 /* sqrt(x) < y is x >= 0 when y is very large and we
4696 don't care about Infinities. */
4697 if (! HONOR_INFINITIES (mode))
4698 return fold (build (GE_EXPR, type, arg,
4699 build_real (TREE_TYPE (arg), dconst0)));
4701 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
4702 if ((*lang_hooks.decls.global_bindings_p) () != 0
4703 || CONTAINS_PLACEHOLDER_P (arg))
4706 arg = save_expr (arg);
4707 return fold (build (TRUTH_ANDIF_EXPR, type,
4708 fold (build (GE_EXPR, type, arg,
4709 build_real (TREE_TYPE (arg),
4711 fold (build (NE_EXPR, type, arg,
4712 build_real (TREE_TYPE (arg),
4716 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
4717 if (! HONOR_NANS (mode))
4718 return fold (build (code, type, arg,
4719 build_real (TREE_TYPE (arg), c2)));
4721 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
4722 if ((*lang_hooks.decls.global_bindings_p) () == 0
4723 && ! CONTAINS_PLACEHOLDER_P (arg))
4725 arg = save_expr (arg);
4726 return fold (build (TRUTH_ANDIF_EXPR, type,
4727 fold (build (GE_EXPR, type, arg,
4728 build_real (TREE_TYPE (arg),
4730 fold (build (code, type, arg,
4731 build_real (TREE_TYPE (arg),
4740 /* Subroutine of fold() that optimizes comparisons against Infinities,
4741 either +Inf or -Inf.
4743 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
4744 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
4745 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
4747 The function returns the constant folded tree if a simplification
4748 can be made, and NULL_TREE otherwise. */
4751 fold_inf_compare (enum tree_code code, tree type, tree arg0, tree arg1)
4753 enum machine_mode mode;
4754 REAL_VALUE_TYPE max;
4758 mode = TYPE_MODE (TREE_TYPE (arg0));
4760 /* For negative infinity swap the sense of the comparison. */
4761 neg = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1));
4763 code = swap_tree_comparison (code);
4768 /* x > +Inf is always false, if with ignore sNANs. */
4769 if (HONOR_SNANS (mode))
4771 return omit_one_operand (type,
4772 convert (type, integer_zero_node),
4776 /* x <= +Inf is always true, if we don't case about NaNs. */
4777 if (! HONOR_NANS (mode))
4778 return omit_one_operand (type,
4779 convert (type, integer_one_node),
4782 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
4783 if ((*lang_hooks.decls.global_bindings_p) () == 0
4784 && ! CONTAINS_PLACEHOLDER_P (arg0))
4786 arg0 = save_expr (arg0);
4787 return fold (build (EQ_EXPR, type, arg0, arg0));
4793 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
4794 real_maxval (&max, neg, mode);
4795 return fold (build (neg ? LT_EXPR : GT_EXPR, type,
4796 arg0, build_real (TREE_TYPE (arg0), max)));
4799 /* x < +Inf is always equal to x <= DBL_MAX. */
4800 real_maxval (&max, neg, mode);
4801 return fold (build (neg ? GE_EXPR : LE_EXPR, type,
4802 arg0, build_real (TREE_TYPE (arg0), max)));
4805 /* x != +Inf is always equal to !(x > DBL_MAX). */
4806 real_maxval (&max, neg, mode);
4807 if (! HONOR_NANS (mode))
4808 return fold (build (neg ? GE_EXPR : LE_EXPR, type,
4809 arg0, build_real (TREE_TYPE (arg0), max)));
4810 temp = fold (build (neg ? LT_EXPR : GT_EXPR, type,
4811 arg0, build_real (TREE_TYPE (arg0), max)));
4812 return fold (build1 (TRUTH_NOT_EXPR, type, temp));
4821 /* If CODE with arguments ARG0 and ARG1 represents a single bit
4822 equality/inequality test, then return a simplified form of
4823 the test using shifts and logical operations. Otherwise return
4824 NULL. TYPE is the desired result type. */
4827 fold_single_bit_test (enum tree_code code, tree arg0, tree arg1,
4830 /* If this is a TRUTH_NOT_EXPR, it may have a single bit test inside
4832 if (code == TRUTH_NOT_EXPR)
4834 code = TREE_CODE (arg0);
4835 if (code != NE_EXPR && code != EQ_EXPR)
4838 /* Extract the arguments of the EQ/NE. */
4839 arg1 = TREE_OPERAND (arg0, 1);
4840 arg0 = TREE_OPERAND (arg0, 0);
4842 /* This requires us to invert the code. */
4843 code = (code == EQ_EXPR ? NE_EXPR : EQ_EXPR);
4846 /* If this is testing a single bit, we can optimize the test. */
4847 if ((code == NE_EXPR || code == EQ_EXPR)
4848 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
4849 && integer_pow2p (TREE_OPERAND (arg0, 1)))
4851 tree inner = TREE_OPERAND (arg0, 0);
4852 tree type = TREE_TYPE (arg0);
4853 int bitnum = tree_log2 (TREE_OPERAND (arg0, 1));
4854 enum machine_mode operand_mode = TYPE_MODE (type);
4856 tree signed_type, unsigned_type;
4859 /* If we have (A & C) != 0 where C is the sign bit of A, convert
4860 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
4861 arg00 = sign_bit_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
4862 if (arg00 != NULL_TREE)
4864 tree stype = (*lang_hooks.types.signed_type) (TREE_TYPE (arg00));
4865 return fold (build (code == EQ_EXPR ? GE_EXPR : LT_EXPR, result_type,
4866 convert (stype, arg00),
4867 convert (stype, integer_zero_node)));
4870 /* At this point, we know that arg0 is not testing the sign bit. */
4871 if (TYPE_PRECISION (type) - 1 == bitnum)
4874 /* Otherwise we have (A & C) != 0 where C is a single bit,
4875 convert that into ((A >> C2) & 1). Where C2 = log2(C).
4876 Similarly for (A & C) == 0. */
4878 /* If INNER is a right shift of a constant and it plus BITNUM does
4879 not overflow, adjust BITNUM and INNER. */
4880 if (TREE_CODE (inner) == RSHIFT_EXPR
4881 && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST
4882 && TREE_INT_CST_HIGH (TREE_OPERAND (inner, 1)) == 0
4883 && bitnum < TYPE_PRECISION (type)
4884 && 0 > compare_tree_int (TREE_OPERAND (inner, 1),
4885 bitnum - TYPE_PRECISION (type)))
4887 bitnum += TREE_INT_CST_LOW (TREE_OPERAND (inner, 1));
4888 inner = TREE_OPERAND (inner, 0);
4891 /* If we are going to be able to omit the AND below, we must do our
4892 operations as unsigned. If we must use the AND, we have a choice.
4893 Normally unsigned is faster, but for some machines signed is. */
4894 #ifdef LOAD_EXTEND_OP
4895 ops_unsigned = (LOAD_EXTEND_OP (operand_mode) == SIGN_EXTEND ? 0 : 1);
4900 signed_type = (*lang_hooks.types.type_for_mode) (operand_mode, 0);
4901 unsigned_type = (*lang_hooks.types.type_for_mode) (operand_mode, 1);
4904 inner = build (RSHIFT_EXPR, ops_unsigned ? unsigned_type : signed_type,
4905 inner, size_int (bitnum));
4907 if (code == EQ_EXPR)
4908 inner = build (BIT_XOR_EXPR, ops_unsigned ? unsigned_type : signed_type,
4909 inner, integer_one_node);
4911 /* Put the AND last so it can combine with more things. */
4912 inner = build (BIT_AND_EXPR, ops_unsigned ? unsigned_type : signed_type,
4913 inner, integer_one_node);
4915 /* Make sure to return the proper type. */
4916 if (TREE_TYPE (inner) != result_type)
4917 inner = convert (result_type, inner);
4924 /* Perform constant folding and related simplification of EXPR.
4925 The related simplifications include x*1 => x, x*0 => 0, etc.,
4926 and application of the associative law.
4927 NOP_EXPR conversions may be removed freely (as long as we
4928 are careful not to change the C type of the overall expression)
4929 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
4930 but we can constant-fold them if they have constant operands. */
4936 tree t1 = NULL_TREE;
4938 tree type = TREE_TYPE (expr);
4939 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
4940 enum tree_code code = TREE_CODE (t);
4941 int kind = TREE_CODE_CLASS (code);
4943 /* WINS will be nonzero when the switch is done
4944 if all operands are constant. */
4947 /* Don't try to process an RTL_EXPR since its operands aren't trees.
4948 Likewise for a SAVE_EXPR that's already been evaluated. */
4949 if (code == RTL_EXPR || (code == SAVE_EXPR && SAVE_EXPR_RTL (t) != 0))
4952 /* Return right away if a constant. */
4956 #ifdef MAX_INTEGER_COMPUTATION_MODE
4957 check_max_integer_computation_mode (expr);
4960 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
4964 /* Special case for conversion ops that can have fixed point args. */
4965 arg0 = TREE_OPERAND (t, 0);
4967 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
4969 STRIP_SIGN_NOPS (arg0);
4971 if (arg0 != 0 && TREE_CODE (arg0) == COMPLEX_CST)
4972 subop = TREE_REALPART (arg0);
4976 if (subop != 0 && TREE_CODE (subop) != INTEGER_CST
4977 && TREE_CODE (subop) != REAL_CST
4979 /* Note that TREE_CONSTANT isn't enough:
4980 static var addresses are constant but we can't
4981 do arithmetic on them. */
4984 else if (IS_EXPR_CODE_CLASS (kind) || kind == 'r')
4986 int len = first_rtl_op (code);
4988 for (i = 0; i < len; i++)
4990 tree op = TREE_OPERAND (t, i);
4994 continue; /* Valid for CALL_EXPR, at least. */
4996 if (kind == '<' || code == RSHIFT_EXPR)
4998 /* Signedness matters here. Perhaps we can refine this
5000 STRIP_SIGN_NOPS (op);
5003 /* Strip any conversions that don't change the mode. */
5006 if (TREE_CODE (op) == COMPLEX_CST)
5007 subop = TREE_REALPART (op);
5011 if (TREE_CODE (subop) != INTEGER_CST
5012 && TREE_CODE (subop) != REAL_CST)
5013 /* Note that TREE_CONSTANT isn't enough:
5014 static var addresses are constant but we can't
5015 do arithmetic on them. */
5025 /* If this is a commutative operation, and ARG0 is a constant, move it
5026 to ARG1 to reduce the number of tests below. */
5027 if ((code == PLUS_EXPR || code == MULT_EXPR || code == MIN_EXPR
5028 || code == MAX_EXPR || code == BIT_IOR_EXPR || code == BIT_XOR_EXPR
5029 || code == BIT_AND_EXPR)
5030 && (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST))
5032 tem = arg0; arg0 = arg1; arg1 = tem;
5034 tem = TREE_OPERAND (t, 0); TREE_OPERAND (t, 0) = TREE_OPERAND (t, 1);
5035 TREE_OPERAND (t, 1) = tem;
5038 /* Now WINS is set as described above,
5039 ARG0 is the first operand of EXPR,
5040 and ARG1 is the second operand (if it has more than one operand).
5042 First check for cases where an arithmetic operation is applied to a
5043 compound, conditional, or comparison operation. Push the arithmetic
5044 operation inside the compound or conditional to see if any folding
5045 can then be done. Convert comparison to conditional for this purpose.
5046 The also optimizes non-constant cases that used to be done in
5049 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
5050 one of the operands is a comparison and the other is a comparison, a
5051 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
5052 code below would make the expression more complex. Change it to a
5053 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
5054 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
5056 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
5057 || code == EQ_EXPR || code == NE_EXPR)
5058 && ((truth_value_p (TREE_CODE (arg0))
5059 && (truth_value_p (TREE_CODE (arg1))
5060 || (TREE_CODE (arg1) == BIT_AND_EXPR
5061 && integer_onep (TREE_OPERAND (arg1, 1)))))
5062 || (truth_value_p (TREE_CODE (arg1))
5063 && (truth_value_p (TREE_CODE (arg0))
5064 || (TREE_CODE (arg0) == BIT_AND_EXPR
5065 && integer_onep (TREE_OPERAND (arg0, 1)))))))
5067 t = fold (build (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
5068 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
5072 if (code == EQ_EXPR)
5073 t = invert_truthvalue (t);
5078 if (TREE_CODE_CLASS (code) == '1')
5080 if (TREE_CODE (arg0) == COMPOUND_EXPR)
5081 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5082 fold (build1 (code, type, TREE_OPERAND (arg0, 1))));
5083 else if (TREE_CODE (arg0) == COND_EXPR)
5085 tree arg01 = TREE_OPERAND (arg0, 1);
5086 tree arg02 = TREE_OPERAND (arg0, 2);
5087 if (! VOID_TYPE_P (TREE_TYPE (arg01)))
5088 arg01 = fold (build1 (code, type, arg01));
5089 if (! VOID_TYPE_P (TREE_TYPE (arg02)))
5090 arg02 = fold (build1 (code, type, arg02));
5091 t = fold (build (COND_EXPR, type, TREE_OPERAND (arg0, 0),
5094 /* If this was a conversion, and all we did was to move into
5095 inside the COND_EXPR, bring it back out. But leave it if
5096 it is a conversion from integer to integer and the
5097 result precision is no wider than a word since such a
5098 conversion is cheap and may be optimized away by combine,
5099 while it couldn't if it were outside the COND_EXPR. Then return
5100 so we don't get into an infinite recursion loop taking the
5101 conversion out and then back in. */
5103 if ((code == NOP_EXPR || code == CONVERT_EXPR
5104 || code == NON_LVALUE_EXPR)
5105 && TREE_CODE (t) == COND_EXPR
5106 && TREE_CODE (TREE_OPERAND (t, 1)) == code
5107 && TREE_CODE (TREE_OPERAND (t, 2)) == code
5108 && ! VOID_TYPE_P (TREE_OPERAND (t, 1))
5109 && ! VOID_TYPE_P (TREE_OPERAND (t, 2))
5110 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))
5111 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 2), 0)))
5112 && ! (INTEGRAL_TYPE_P (TREE_TYPE (t))
5114 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))))
5115 && TYPE_PRECISION (TREE_TYPE (t)) <= BITS_PER_WORD))
5116 t = build1 (code, type,
5118 TREE_TYPE (TREE_OPERAND
5119 (TREE_OPERAND (t, 1), 0)),
5120 TREE_OPERAND (t, 0),
5121 TREE_OPERAND (TREE_OPERAND (t, 1), 0),
5122 TREE_OPERAND (TREE_OPERAND (t, 2), 0)));
5125 else if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<')
5126 return fold (build (COND_EXPR, type, arg0,
5127 fold (build1 (code, type, integer_one_node)),
5128 fold (build1 (code, type, integer_zero_node))));
5130 else if (TREE_CODE_CLASS (code) == '<'
5131 && TREE_CODE (arg0) == COMPOUND_EXPR)
5132 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5133 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
5134 else if (TREE_CODE_CLASS (code) == '<'
5135 && TREE_CODE (arg1) == COMPOUND_EXPR)
5136 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
5137 fold (build (code, type, arg0, TREE_OPERAND (arg1, 1))));
5138 else if (TREE_CODE_CLASS (code) == '2'
5139 || TREE_CODE_CLASS (code) == '<')
5141 if (TREE_CODE (arg1) == COMPOUND_EXPR
5142 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg1, 0))
5143 && ! TREE_SIDE_EFFECTS (arg0))
5144 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
5145 fold (build (code, type,
5146 arg0, TREE_OPERAND (arg1, 1))));
5147 else if ((TREE_CODE (arg1) == COND_EXPR
5148 || (TREE_CODE_CLASS (TREE_CODE (arg1)) == '<'
5149 && TREE_CODE_CLASS (code) != '<'))
5150 && (TREE_CODE (arg0) != COND_EXPR
5151 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
5152 && (! TREE_SIDE_EFFECTS (arg0)
5153 || ((*lang_hooks.decls.global_bindings_p) () == 0
5154 && ! CONTAINS_PLACEHOLDER_P (arg0))))
5156 fold_binary_op_with_conditional_arg (code, type, arg1, arg0,
5157 /*cond_first_p=*/0);
5158 else if (TREE_CODE (arg0) == COMPOUND_EXPR)
5159 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5160 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
5161 else if ((TREE_CODE (arg0) == COND_EXPR
5162 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
5163 && TREE_CODE_CLASS (code) != '<'))
5164 && (TREE_CODE (arg1) != COND_EXPR
5165 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
5166 && (! TREE_SIDE_EFFECTS (arg1)
5167 || ((*lang_hooks.decls.global_bindings_p) () == 0
5168 && ! CONTAINS_PLACEHOLDER_P (arg1))))
5170 fold_binary_op_with_conditional_arg (code, type, arg0, arg1,
5171 /*cond_first_p=*/1);
5185 return fold (DECL_INITIAL (t));
5190 case FIX_TRUNC_EXPR:
5191 /* Other kinds of FIX are not handled properly by fold_convert. */
5193 if (TREE_TYPE (TREE_OPERAND (t, 0)) == TREE_TYPE (t))
5194 return TREE_OPERAND (t, 0);
5196 /* Handle cases of two conversions in a row. */
5197 if (TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
5198 || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR)
5200 tree inside_type = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5201 tree inter_type = TREE_TYPE (TREE_OPERAND (t, 0));
5202 tree final_type = TREE_TYPE (t);
5203 int inside_int = INTEGRAL_TYPE_P (inside_type);
5204 int inside_ptr = POINTER_TYPE_P (inside_type);
5205 int inside_float = FLOAT_TYPE_P (inside_type);
5206 unsigned int inside_prec = TYPE_PRECISION (inside_type);
5207 int inside_unsignedp = TREE_UNSIGNED (inside_type);
5208 int inter_int = INTEGRAL_TYPE_P (inter_type);
5209 int inter_ptr = POINTER_TYPE_P (inter_type);
5210 int inter_float = FLOAT_TYPE_P (inter_type);
5211 unsigned int inter_prec = TYPE_PRECISION (inter_type);
5212 int inter_unsignedp = TREE_UNSIGNED (inter_type);
5213 int final_int = INTEGRAL_TYPE_P (final_type);
5214 int final_ptr = POINTER_TYPE_P (final_type);
5215 int final_float = FLOAT_TYPE_P (final_type);
5216 unsigned int final_prec = TYPE_PRECISION (final_type);
5217 int final_unsignedp = TREE_UNSIGNED (final_type);
5219 /* In addition to the cases of two conversions in a row
5220 handled below, if we are converting something to its own
5221 type via an object of identical or wider precision, neither
5222 conversion is needed. */
5223 if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (final_type)
5224 && ((inter_int && final_int) || (inter_float && final_float))
5225 && inter_prec >= final_prec)
5226 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5228 /* Likewise, if the intermediate and final types are either both
5229 float or both integer, we don't need the middle conversion if
5230 it is wider than the final type and doesn't change the signedness
5231 (for integers). Avoid this if the final type is a pointer
5232 since then we sometimes need the inner conversion. Likewise if
5233 the outer has a precision not equal to the size of its mode. */
5234 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
5235 || (inter_float && inside_float))
5236 && inter_prec >= inside_prec
5237 && (inter_float || inter_unsignedp == inside_unsignedp)
5238 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
5239 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
5241 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5243 /* If we have a sign-extension of a zero-extended value, we can
5244 replace that by a single zero-extension. */
5245 if (inside_int && inter_int && final_int
5246 && inside_prec < inter_prec && inter_prec < final_prec
5247 && inside_unsignedp && !inter_unsignedp)
5248 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5250 /* Two conversions in a row are not needed unless:
5251 - some conversion is floating-point (overstrict for now), or
5252 - the intermediate type is narrower than both initial and
5254 - the intermediate type and innermost type differ in signedness,
5255 and the outermost type is wider than the intermediate, or
5256 - the initial type is a pointer type and the precisions of the
5257 intermediate and final types differ, or
5258 - the final type is a pointer type and the precisions of the
5259 initial and intermediate types differ. */
5260 if (! inside_float && ! inter_float && ! final_float
5261 && (inter_prec > inside_prec || inter_prec > final_prec)
5262 && ! (inside_int && inter_int
5263 && inter_unsignedp != inside_unsignedp
5264 && inter_prec < final_prec)
5265 && ((inter_unsignedp && inter_prec > inside_prec)
5266 == (final_unsignedp && final_prec > inter_prec))
5267 && ! (inside_ptr && inter_prec != final_prec)
5268 && ! (final_ptr && inside_prec != inter_prec)
5269 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
5270 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
5272 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5275 if (TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR
5276 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t, 0), 1))
5277 /* Detect assigning a bitfield. */
5278 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) == COMPONENT_REF
5279 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 1))))
5281 /* Don't leave an assignment inside a conversion
5282 unless assigning a bitfield. */
5283 tree prev = TREE_OPERAND (t, 0);
5284 TREE_OPERAND (t, 0) = TREE_OPERAND (prev, 1);
5285 /* First do the assignment, then return converted constant. */
5286 t = build (COMPOUND_EXPR, TREE_TYPE (t), prev, fold (t));
5291 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
5292 constants (if x has signed type, the sign bit cannot be set
5293 in c). This folds extension into the BIT_AND_EXPR. */
5294 if (INTEGRAL_TYPE_P (TREE_TYPE (t))
5295 && TREE_CODE (TREE_TYPE (t)) != BOOLEAN_TYPE
5296 && TREE_CODE (TREE_OPERAND (t, 0)) == BIT_AND_EXPR
5297 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 1)) == INTEGER_CST)
5299 tree and = TREE_OPERAND (t, 0);
5300 tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
5303 if (TREE_UNSIGNED (TREE_TYPE (and))
5304 || (TYPE_PRECISION (TREE_TYPE (t))
5305 <= TYPE_PRECISION (TREE_TYPE (and))))
5307 else if (TYPE_PRECISION (TREE_TYPE (and1))
5308 <= HOST_BITS_PER_WIDE_INT
5309 && host_integerp (and1, 1))
5311 unsigned HOST_WIDE_INT cst;
5313 cst = tree_low_cst (and1, 1);
5314 cst &= (HOST_WIDE_INT) -1
5315 << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
5316 change = (cst == 0);
5317 #ifdef LOAD_EXTEND_OP
5319 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
5322 tree uns = (*lang_hooks.types.unsigned_type) (TREE_TYPE (and0));
5323 and0 = convert (uns, and0);
5324 and1 = convert (uns, and1);
5329 return fold (build (BIT_AND_EXPR, TREE_TYPE (t),
5330 convert (TREE_TYPE (t), and0),
5331 convert (TREE_TYPE (t), and1)));
5336 TREE_CONSTANT (t) = TREE_CONSTANT (arg0);
5339 return fold_convert (t, arg0);
5341 case VIEW_CONVERT_EXPR:
5342 if (TREE_CODE (TREE_OPERAND (t, 0)) == VIEW_CONVERT_EXPR)
5343 return build1 (VIEW_CONVERT_EXPR, type,
5344 TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5348 if (TREE_CODE (arg0) == CONSTRUCTOR
5349 && ! type_contains_placeholder_p (TREE_TYPE (arg0)))
5351 tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0));
5358 TREE_CONSTANT (t) = wins;
5364 if (TREE_CODE (arg0) == INTEGER_CST)
5366 unsigned HOST_WIDE_INT low;
5368 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
5369 TREE_INT_CST_HIGH (arg0),
5371 t = build_int_2 (low, high);
5372 TREE_TYPE (t) = type;
5374 = (TREE_OVERFLOW (arg0)
5375 | force_fit_type (t, overflow && !TREE_UNSIGNED (type)));
5376 TREE_CONSTANT_OVERFLOW (t)
5377 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
5379 else if (TREE_CODE (arg0) == REAL_CST)
5380 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
5382 else if (TREE_CODE (arg0) == NEGATE_EXPR)
5383 return TREE_OPERAND (arg0, 0);
5384 /* Convert -((double)float) into (double)(-float). */
5385 else if (TREE_CODE (arg0) == NOP_EXPR
5386 && TREE_CODE (type) == REAL_TYPE)
5388 tree targ0 = strip_float_extensions (arg0);
5390 return convert (type, build1 (NEGATE_EXPR, TREE_TYPE (targ0), targ0));
5394 /* Convert - (a - b) to (b - a) for non-floating-point. */
5395 else if (TREE_CODE (arg0) == MINUS_EXPR
5396 && (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
5397 return build (MINUS_EXPR, type, TREE_OPERAND (arg0, 1),
5398 TREE_OPERAND (arg0, 0));
5400 /* Convert -f(x) into f(-x) where f is sin, tan or atan. */
5401 switch (builtin_mathfn_code (arg0))
5410 case BUILT_IN_ATANF:
5411 case BUILT_IN_ATANL:
5412 if (negate_expr_p (TREE_VALUE (TREE_OPERAND (arg0, 1))))
5414 tree fndecl, arg, arglist;
5416 fndecl = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
5417 arg = TREE_VALUE (TREE_OPERAND (arg0, 1));
5418 arg = fold (build1 (NEGATE_EXPR, type, arg));
5419 arglist = build_tree_list (NULL_TREE, arg);
5420 return build_function_call_expr (fndecl, arglist);
5432 if (TREE_CODE (arg0) == INTEGER_CST)
5434 /* If the value is unsigned, then the absolute value is
5435 the same as the ordinary value. */
5436 if (TREE_UNSIGNED (type))
5438 /* Similarly, if the value is non-negative. */
5439 else if (INT_CST_LT (integer_minus_one_node, arg0))
5441 /* If the value is negative, then the absolute value is
5445 unsigned HOST_WIDE_INT low;
5447 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
5448 TREE_INT_CST_HIGH (arg0),
5450 t = build_int_2 (low, high);
5451 TREE_TYPE (t) = type;
5453 = (TREE_OVERFLOW (arg0)
5454 | force_fit_type (t, overflow));
5455 TREE_CONSTANT_OVERFLOW (t)
5456 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
5459 else if (TREE_CODE (arg0) == REAL_CST)
5461 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
5462 t = build_real (type,
5463 REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
5466 else if (TREE_CODE (arg0) == NEGATE_EXPR)
5467 return fold (build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0)));
5468 /* Convert fabs((double)float) into (double)fabsf(float). */
5469 else if (TREE_CODE (arg0) == NOP_EXPR
5470 && TREE_CODE (type) == REAL_TYPE)
5472 tree targ0 = strip_float_extensions (arg0);
5474 return convert (type, fold (build1 (ABS_EXPR, TREE_TYPE (targ0),
5477 else if (tree_expr_nonnegative_p (arg0))
5482 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
5483 return convert (type, arg0);
5484 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
5485 return build (COMPLEX_EXPR, type,
5486 TREE_OPERAND (arg0, 0),
5487 negate_expr (TREE_OPERAND (arg0, 1)));
5488 else if (TREE_CODE (arg0) == COMPLEX_CST)
5489 return build_complex (type, TREE_REALPART (arg0),
5490 negate_expr (TREE_IMAGPART (arg0)));
5491 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
5492 return fold (build (TREE_CODE (arg0), type,
5493 fold (build1 (CONJ_EXPR, type,
5494 TREE_OPERAND (arg0, 0))),
5495 fold (build1 (CONJ_EXPR,
5496 type, TREE_OPERAND (arg0, 1)))));
5497 else if (TREE_CODE (arg0) == CONJ_EXPR)
5498 return TREE_OPERAND (arg0, 0);
5504 t = build_int_2 (~ TREE_INT_CST_LOW (arg0),
5505 ~ TREE_INT_CST_HIGH (arg0));
5506 TREE_TYPE (t) = type;
5507 force_fit_type (t, 0);
5508 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg0);
5509 TREE_CONSTANT_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (arg0);
5511 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
5512 return TREE_OPERAND (arg0, 0);
5516 /* A + (-B) -> A - B */
5517 if (TREE_CODE (arg1) == NEGATE_EXPR)
5518 return fold (build (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5519 /* (-A) + B -> B - A */
5520 if (TREE_CODE (arg0) == NEGATE_EXPR)
5521 return fold (build (MINUS_EXPR, type, arg1, TREE_OPERAND (arg0, 0)));
5522 else if (! FLOAT_TYPE_P (type))
5524 if (integer_zerop (arg1))
5525 return non_lvalue (convert (type, arg0));
5527 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
5528 with a constant, and the two constants have no bits in common,
5529 we should treat this as a BIT_IOR_EXPR since this may produce more
5531 if (TREE_CODE (arg0) == BIT_AND_EXPR
5532 && TREE_CODE (arg1) == BIT_AND_EXPR
5533 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5534 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
5535 && integer_zerop (const_binop (BIT_AND_EXPR,
5536 TREE_OPERAND (arg0, 1),
5537 TREE_OPERAND (arg1, 1), 0)))
5539 code = BIT_IOR_EXPR;
5543 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
5544 (plus (plus (mult) (mult)) (foo)) so that we can
5545 take advantage of the factoring cases below. */
5546 if ((TREE_CODE (arg0) == PLUS_EXPR
5547 && TREE_CODE (arg1) == MULT_EXPR)
5548 || (TREE_CODE (arg1) == PLUS_EXPR
5549 && TREE_CODE (arg0) == MULT_EXPR))
5551 tree parg0, parg1, parg, marg;
5553 if (TREE_CODE (arg0) == PLUS_EXPR)
5554 parg = arg0, marg = arg1;
5556 parg = arg1, marg = arg0;
5557 parg0 = TREE_OPERAND (parg, 0);
5558 parg1 = TREE_OPERAND (parg, 1);
5562 if (TREE_CODE (parg0) == MULT_EXPR
5563 && TREE_CODE (parg1) != MULT_EXPR)
5564 return fold (build (PLUS_EXPR, type,
5565 fold (build (PLUS_EXPR, type,
5566 convert (type, parg0),
5567 convert (type, marg))),
5568 convert (type, parg1)));
5569 if (TREE_CODE (parg0) != MULT_EXPR
5570 && TREE_CODE (parg1) == MULT_EXPR)
5571 return fold (build (PLUS_EXPR, type,
5572 fold (build (PLUS_EXPR, type,
5573 convert (type, parg1),
5574 convert (type, marg))),
5575 convert (type, parg0)));
5578 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR)
5580 tree arg00, arg01, arg10, arg11;
5581 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
5583 /* (A * C) + (B * C) -> (A+B) * C.
5584 We are most concerned about the case where C is a constant,
5585 but other combinations show up during loop reduction. Since
5586 it is not difficult, try all four possibilities. */
5588 arg00 = TREE_OPERAND (arg0, 0);
5589 arg01 = TREE_OPERAND (arg0, 1);
5590 arg10 = TREE_OPERAND (arg1, 0);
5591 arg11 = TREE_OPERAND (arg1, 1);
5594 if (operand_equal_p (arg01, arg11, 0))
5595 same = arg01, alt0 = arg00, alt1 = arg10;
5596 else if (operand_equal_p (arg00, arg10, 0))
5597 same = arg00, alt0 = arg01, alt1 = arg11;
5598 else if (operand_equal_p (arg00, arg11, 0))
5599 same = arg00, alt0 = arg01, alt1 = arg10;
5600 else if (operand_equal_p (arg01, arg10, 0))
5601 same = arg01, alt0 = arg00, alt1 = arg11;
5603 /* No identical multiplicands; see if we can find a common
5604 power-of-two factor in non-power-of-two multiplies. This
5605 can help in multi-dimensional array access. */
5606 else if (TREE_CODE (arg01) == INTEGER_CST
5607 && TREE_CODE (arg11) == INTEGER_CST
5608 && TREE_INT_CST_HIGH (arg01) == 0
5609 && TREE_INT_CST_HIGH (arg11) == 0)
5611 HOST_WIDE_INT int01, int11, tmp;
5612 int01 = TREE_INT_CST_LOW (arg01);
5613 int11 = TREE_INT_CST_LOW (arg11);
5615 /* Move min of absolute values to int11. */
5616 if ((int01 >= 0 ? int01 : -int01)
5617 < (int11 >= 0 ? int11 : -int11))
5619 tmp = int01, int01 = int11, int11 = tmp;
5620 alt0 = arg00, arg00 = arg10, arg10 = alt0;
5621 alt0 = arg01, arg01 = arg11, arg11 = alt0;
5624 if (exact_log2 (int11) > 0 && int01 % int11 == 0)
5626 alt0 = fold (build (MULT_EXPR, type, arg00,
5627 build_int_2 (int01 / int11, 0)));
5634 return fold (build (MULT_EXPR, type,
5635 fold (build (PLUS_EXPR, type, alt0, alt1)),
5640 /* See if ARG1 is zero and X + ARG1 reduces to X. */
5641 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
5642 return non_lvalue (convert (type, arg0));
5644 /* Likewise if the operands are reversed. */
5645 else if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
5646 return non_lvalue (convert (type, arg1));
5649 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
5650 is a rotate of A by C1 bits. */
5651 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
5652 is a rotate of A by B bits. */
5654 enum tree_code code0, code1;
5655 code0 = TREE_CODE (arg0);
5656 code1 = TREE_CODE (arg1);
5657 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
5658 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
5659 && operand_equal_p (TREE_OPERAND (arg0, 0),
5660 TREE_OPERAND (arg1, 0), 0)
5661 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5663 tree tree01, tree11;
5664 enum tree_code code01, code11;
5666 tree01 = TREE_OPERAND (arg0, 1);
5667 tree11 = TREE_OPERAND (arg1, 1);
5668 STRIP_NOPS (tree01);
5669 STRIP_NOPS (tree11);
5670 code01 = TREE_CODE (tree01);
5671 code11 = TREE_CODE (tree11);
5672 if (code01 == INTEGER_CST
5673 && code11 == INTEGER_CST
5674 && TREE_INT_CST_HIGH (tree01) == 0
5675 && TREE_INT_CST_HIGH (tree11) == 0
5676 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
5677 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
5678 return build (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
5679 code0 == LSHIFT_EXPR ? tree01 : tree11);
5680 else if (code11 == MINUS_EXPR)
5682 tree tree110, tree111;
5683 tree110 = TREE_OPERAND (tree11, 0);
5684 tree111 = TREE_OPERAND (tree11, 1);
5685 STRIP_NOPS (tree110);
5686 STRIP_NOPS (tree111);
5687 if (TREE_CODE (tree110) == INTEGER_CST
5688 && 0 == compare_tree_int (tree110,
5690 (TREE_TYPE (TREE_OPERAND
5692 && operand_equal_p (tree01, tree111, 0))
5693 return build ((code0 == LSHIFT_EXPR
5696 type, TREE_OPERAND (arg0, 0), tree01);
5698 else if (code01 == MINUS_EXPR)
5700 tree tree010, tree011;
5701 tree010 = TREE_OPERAND (tree01, 0);
5702 tree011 = TREE_OPERAND (tree01, 1);
5703 STRIP_NOPS (tree010);
5704 STRIP_NOPS (tree011);
5705 if (TREE_CODE (tree010) == INTEGER_CST
5706 && 0 == compare_tree_int (tree010,
5708 (TREE_TYPE (TREE_OPERAND
5710 && operand_equal_p (tree11, tree011, 0))
5711 return build ((code0 != LSHIFT_EXPR
5714 type, TREE_OPERAND (arg0, 0), tree11);
5720 /* In most languages, can't associate operations on floats through
5721 parentheses. Rather than remember where the parentheses were, we
5722 don't associate floats at all. It shouldn't matter much. However,
5723 associating multiplications is only very slightly inaccurate, so do
5724 that if -funsafe-math-optimizations is specified. */
5727 && (! FLOAT_TYPE_P (type)
5728 || (flag_unsafe_math_optimizations && code == MULT_EXPR)))
5730 tree var0, con0, lit0, minus_lit0;
5731 tree var1, con1, lit1, minus_lit1;
5733 /* Split both trees into variables, constants, and literals. Then
5734 associate each group together, the constants with literals,
5735 then the result with variables. This increases the chances of
5736 literals being recombined later and of generating relocatable
5737 expressions for the sum of a constant and literal. */
5738 var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
5739 var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
5740 code == MINUS_EXPR);
5742 /* Only do something if we found more than two objects. Otherwise,
5743 nothing has changed and we risk infinite recursion. */
5744 if (2 < ((var0 != 0) + (var1 != 0)
5745 + (con0 != 0) + (con1 != 0)
5746 + (lit0 != 0) + (lit1 != 0)
5747 + (minus_lit0 != 0) + (minus_lit1 != 0)))
5749 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
5750 if (code == MINUS_EXPR)
5753 var0 = associate_trees (var0, var1, code, type);
5754 con0 = associate_trees (con0, con1, code, type);
5755 lit0 = associate_trees (lit0, lit1, code, type);
5756 minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
5758 /* Preserve the MINUS_EXPR if the negative part of the literal is
5759 greater than the positive part. Otherwise, the multiplicative
5760 folding code (i.e extract_muldiv) may be fooled in case
5761 unsigned constants are subtracted, like in the following
5762 example: ((X*2 + 4) - 8U)/2. */
5763 if (minus_lit0 && lit0)
5765 if (tree_int_cst_lt (lit0, minus_lit0))
5767 minus_lit0 = associate_trees (minus_lit0, lit0,
5773 lit0 = associate_trees (lit0, minus_lit0,
5781 return convert (type, associate_trees (var0, minus_lit0,
5785 con0 = associate_trees (con0, minus_lit0,
5787 return convert (type, associate_trees (var0, con0,
5792 con0 = associate_trees (con0, lit0, code, type);
5793 return convert (type, associate_trees (var0, con0, code, type));
5799 t1 = const_binop (code, arg0, arg1, 0);
5800 if (t1 != NULL_TREE)
5802 /* The return value should always have
5803 the same type as the original expression. */
5804 if (TREE_TYPE (t1) != TREE_TYPE (t))
5805 t1 = convert (TREE_TYPE (t), t1);
5812 /* A - (-B) -> A + B */
5813 if (TREE_CODE (arg1) == NEGATE_EXPR)
5814 return fold (build (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5815 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
5816 if (TREE_CODE (arg0) == NEGATE_EXPR
5817 && (FLOAT_TYPE_P (type)
5818 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv))
5819 && negate_expr_p (arg1)
5820 && (! TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
5821 && (! TREE_SIDE_EFFECTS (arg1) || TREE_CONSTANT (arg0)))
5822 return fold (build (MINUS_EXPR, type, negate_expr (arg1),
5823 TREE_OPERAND (arg0, 0)));
5825 if (! FLOAT_TYPE_P (type))
5827 if (! wins && integer_zerop (arg0))
5828 return negate_expr (convert (type, arg1));
5829 if (integer_zerop (arg1))
5830 return non_lvalue (convert (type, arg0));
5832 /* (A * C) - (B * C) -> (A-B) * C. Since we are most concerned
5833 about the case where C is a constant, just try one of the
5834 four possibilities. */
5836 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR
5837 && operand_equal_p (TREE_OPERAND (arg0, 1),
5838 TREE_OPERAND (arg1, 1), 0))
5839 return fold (build (MULT_EXPR, type,
5840 fold (build (MINUS_EXPR, type,
5841 TREE_OPERAND (arg0, 0),
5842 TREE_OPERAND (arg1, 0))),
5843 TREE_OPERAND (arg0, 1)));
5845 /* Fold A - (A & B) into ~B & A. */
5846 if (!TREE_SIDE_EFFECTS (arg0)
5847 && TREE_CODE (arg1) == BIT_AND_EXPR)
5849 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
5850 return fold (build (BIT_AND_EXPR, type,
5851 fold (build1 (BIT_NOT_EXPR, type,
5852 TREE_OPERAND (arg1, 0))),
5854 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
5855 return fold (build (BIT_AND_EXPR, type,
5856 fold (build1 (BIT_NOT_EXPR, type,
5857 TREE_OPERAND (arg1, 1))),
5862 /* See if ARG1 is zero and X - ARG1 reduces to X. */
5863 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
5864 return non_lvalue (convert (type, arg0));
5866 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
5867 ARG0 is zero and X + ARG0 reduces to X, since that would mean
5868 (-ARG1 + ARG0) reduces to -ARG1. */
5869 else if (!wins && fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
5870 return negate_expr (convert (type, arg1));
5872 /* Fold &x - &x. This can happen from &x.foo - &x.
5873 This is unsafe for certain floats even in non-IEEE formats.
5874 In IEEE, it is unsafe because it does wrong for NaNs.
5875 Also note that operand_equal_p is always false if an operand
5878 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
5879 && operand_equal_p (arg0, arg1, 0))
5880 return convert (type, integer_zero_node);
5885 /* (-A) * (-B) -> A * B */
5886 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR)
5887 return fold (build (MULT_EXPR, type, TREE_OPERAND (arg0, 0),
5888 TREE_OPERAND (arg1, 0)));
5890 if (! FLOAT_TYPE_P (type))
5892 if (integer_zerop (arg1))
5893 return omit_one_operand (type, arg1, arg0);
5894 if (integer_onep (arg1))
5895 return non_lvalue (convert (type, arg0));
5897 /* (a * (1 << b)) is (a << b) */
5898 if (TREE_CODE (arg1) == LSHIFT_EXPR
5899 && integer_onep (TREE_OPERAND (arg1, 0)))
5900 return fold (build (LSHIFT_EXPR, type, arg0,
5901 TREE_OPERAND (arg1, 1)));
5902 if (TREE_CODE (arg0) == LSHIFT_EXPR
5903 && integer_onep (TREE_OPERAND (arg0, 0)))
5904 return fold (build (LSHIFT_EXPR, type, arg1,
5905 TREE_OPERAND (arg0, 1)));
5907 if (TREE_CODE (arg1) == INTEGER_CST
5908 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0),
5909 convert (type, arg1),
5911 return convert (type, tem);
5916 /* Maybe fold x * 0 to 0. The expressions aren't the same
5917 when x is NaN, since x * 0 is also NaN. Nor are they the
5918 same in modes with signed zeros, since multiplying a
5919 negative value by 0 gives -0, not +0. */
5920 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
5921 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
5922 && real_zerop (arg1))
5923 return omit_one_operand (type, arg1, arg0);
5924 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
5925 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
5926 && real_onep (arg1))
5927 return non_lvalue (convert (type, arg0));
5929 /* Transform x * -1.0 into -x. */
5930 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
5931 && real_minus_onep (arg1))
5932 return fold (build1 (NEGATE_EXPR, type, arg0));
5935 if (! wins && real_twop (arg1)
5936 && (*lang_hooks.decls.global_bindings_p) () == 0
5937 && ! CONTAINS_PLACEHOLDER_P (arg0))
5939 tree arg = save_expr (arg0);
5940 return fold (build (PLUS_EXPR, type, arg, arg));
5943 if (flag_unsafe_math_optimizations)
5945 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
5946 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
5948 /* Optimizations of sqrt(...)*sqrt(...). */
5949 if ((fcode0 == BUILT_IN_SQRT && fcode1 == BUILT_IN_SQRT)
5950 || (fcode0 == BUILT_IN_SQRTF && fcode1 == BUILT_IN_SQRTF)
5951 || (fcode0 == BUILT_IN_SQRTL && fcode1 == BUILT_IN_SQRTL))
5953 tree sqrtfn, arg, arglist;
5954 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
5955 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
5957 /* Optimize sqrt(x)*sqrt(x) as x. */
5958 if (operand_equal_p (arg00, arg10, 0)
5959 && ! HONOR_SNANS (TYPE_MODE (type)))
5962 /* Optimize sqrt(x)*sqrt(y) as sqrt(x*y). */
5963 sqrtfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
5964 arg = fold (build (MULT_EXPR, type, arg00, arg10));
5965 arglist = build_tree_list (NULL_TREE, arg);
5966 return build_function_call_expr (sqrtfn, arglist);
5969 /* Optimize exp(x)*exp(y) as exp(x+y). */
5970 if ((fcode0 == BUILT_IN_EXP && fcode1 == BUILT_IN_EXP)
5971 || (fcode0 == BUILT_IN_EXPF && fcode1 == BUILT_IN_EXPF)
5972 || (fcode0 == BUILT_IN_EXPL && fcode1 == BUILT_IN_EXPL))
5974 tree expfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
5975 tree arg = build (PLUS_EXPR, type,
5976 TREE_VALUE (TREE_OPERAND (arg0, 1)),
5977 TREE_VALUE (TREE_OPERAND (arg1, 1)));
5978 tree arglist = build_tree_list (NULL_TREE, fold (arg));
5979 return build_function_call_expr (expfn, arglist);
5982 /* Optimizations of pow(...)*pow(...). */
5983 if ((fcode0 == BUILT_IN_POW && fcode1 == BUILT_IN_POW)
5984 || (fcode0 == BUILT_IN_POWF && fcode1 == BUILT_IN_POWF)
5985 || (fcode0 == BUILT_IN_POWL && fcode1 == BUILT_IN_POWL))
5987 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
5988 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
5990 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
5991 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
5994 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
5995 if (operand_equal_p (arg01, arg11, 0))
5997 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
5998 tree arg = build (MULT_EXPR, type, arg00, arg10);
5999 tree arglist = tree_cons (NULL_TREE, fold (arg),
6000 build_tree_list (NULL_TREE,
6002 return build_function_call_expr (powfn, arglist);
6005 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
6006 if (operand_equal_p (arg00, arg10, 0))
6008 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
6009 tree arg = fold (build (PLUS_EXPR, type, arg01, arg11));
6010 tree arglist = tree_cons (NULL_TREE, arg00,
6011 build_tree_list (NULL_TREE,
6013 return build_function_call_expr (powfn, arglist);
6017 /* Optimize tan(x)*cos(x) as sin(x). */
6018 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_COS)
6019 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_COSF)
6020 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_COSL)
6021 || (fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_TAN)
6022 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_TANF)
6023 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_TANL))
6024 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
6025 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
6033 sinfn = implicit_built_in_decls[BUILT_IN_SIN];
6037 sinfn = implicit_built_in_decls[BUILT_IN_SINF];
6041 sinfn = implicit_built_in_decls[BUILT_IN_SINL];
6047 if (sinfn != NULL_TREE)
6048 return build_function_call_expr (sinfn,
6049 TREE_OPERAND (arg0, 1));
6057 if (integer_all_onesp (arg1))
6058 return omit_one_operand (type, arg1, arg0);
6059 if (integer_zerop (arg1))
6060 return non_lvalue (convert (type, arg0));
6061 t1 = distribute_bit_expr (code, type, arg0, arg1);
6062 if (t1 != NULL_TREE)
6065 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
6067 This results in more efficient code for machines without a NAND
6068 instruction. Combine will canonicalize to the first form
6069 which will allow use of NAND instructions provided by the
6070 backend if they exist. */
6071 if (TREE_CODE (arg0) == BIT_NOT_EXPR
6072 && TREE_CODE (arg1) == BIT_NOT_EXPR)
6074 return fold (build1 (BIT_NOT_EXPR, type,
6075 build (BIT_AND_EXPR, type,
6076 TREE_OPERAND (arg0, 0),
6077 TREE_OPERAND (arg1, 0))));
6080 /* See if this can be simplified into a rotate first. If that
6081 is unsuccessful continue in the association code. */
6085 if (integer_zerop (arg1))
6086 return non_lvalue (convert (type, arg0));
6087 if (integer_all_onesp (arg1))
6088 return fold (build1 (BIT_NOT_EXPR, type, arg0));
6090 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
6091 with a constant, and the two constants have no bits in common,
6092 we should treat this as a BIT_IOR_EXPR since this may produce more
6094 if (TREE_CODE (arg0) == BIT_AND_EXPR
6095 && TREE_CODE (arg1) == BIT_AND_EXPR
6096 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6097 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
6098 && integer_zerop (const_binop (BIT_AND_EXPR,
6099 TREE_OPERAND (arg0, 1),
6100 TREE_OPERAND (arg1, 1), 0)))
6102 code = BIT_IOR_EXPR;
6106 /* See if this can be simplified into a rotate first. If that
6107 is unsuccessful continue in the association code. */
6112 if (integer_all_onesp (arg1))
6113 return non_lvalue (convert (type, arg0));
6114 if (integer_zerop (arg1))
6115 return omit_one_operand (type, arg1, arg0);
6116 t1 = distribute_bit_expr (code, type, arg0, arg1);
6117 if (t1 != NULL_TREE)
6119 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
6120 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
6121 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
6124 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
6126 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
6127 && (~TREE_INT_CST_LOW (arg1)
6128 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
6129 return build1 (NOP_EXPR, type, TREE_OPERAND (arg0, 0));
6132 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
6134 This results in more efficient code for machines without a NOR
6135 instruction. Combine will canonicalize to the first form
6136 which will allow use of NOR instructions provided by the
6137 backend if they exist. */
6138 if (TREE_CODE (arg0) == BIT_NOT_EXPR
6139 && TREE_CODE (arg1) == BIT_NOT_EXPR)
6141 return fold (build1 (BIT_NOT_EXPR, type,
6142 build (BIT_IOR_EXPR, type,
6143 TREE_OPERAND (arg0, 0),
6144 TREE_OPERAND (arg1, 0))));
6149 case BIT_ANDTC_EXPR:
6150 if (integer_all_onesp (arg0))
6151 return non_lvalue (convert (type, arg1));
6152 if (integer_zerop (arg0))
6153 return omit_one_operand (type, arg0, arg1);
6154 if (TREE_CODE (arg1) == INTEGER_CST)
6156 arg1 = fold (build1 (BIT_NOT_EXPR, type, arg1));
6157 code = BIT_AND_EXPR;
6163 /* Don't touch a floating-point divide by zero unless the mode
6164 of the constant can represent infinity. */
6165 if (TREE_CODE (arg1) == REAL_CST
6166 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
6167 && real_zerop (arg1))
6170 /* (-A) / (-B) -> A / B */
6171 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR)
6172 return fold (build (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
6173 TREE_OPERAND (arg1, 0)));
6175 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
6176 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
6177 && real_onep (arg1))
6178 return non_lvalue (convert (type, arg0));
6180 /* If ARG1 is a constant, we can convert this to a multiply by the
6181 reciprocal. This does not have the same rounding properties,
6182 so only do this if -funsafe-math-optimizations. We can actually
6183 always safely do it if ARG1 is a power of two, but it's hard to
6184 tell if it is or not in a portable manner. */
6185 if (TREE_CODE (arg1) == REAL_CST)
6187 if (flag_unsafe_math_optimizations
6188 && 0 != (tem = const_binop (code, build_real (type, dconst1),
6190 return fold (build (MULT_EXPR, type, arg0, tem));
6191 /* Find the reciprocal if optimizing and the result is exact. */
6195 r = TREE_REAL_CST (arg1);
6196 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
6198 tem = build_real (type, r);
6199 return fold (build (MULT_EXPR, type, arg0, tem));
6203 /* Convert A/B/C to A/(B*C). */
6204 if (flag_unsafe_math_optimizations
6205 && TREE_CODE (arg0) == RDIV_EXPR)
6207 return fold (build (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
6208 build (MULT_EXPR, type, TREE_OPERAND (arg0, 1),
6211 /* Convert A/(B/C) to (A/B)*C. */
6212 if (flag_unsafe_math_optimizations
6213 && TREE_CODE (arg1) == RDIV_EXPR)
6215 return fold (build (MULT_EXPR, type,
6216 build (RDIV_EXPR, type, arg0,
6217 TREE_OPERAND (arg1, 0)),
6218 TREE_OPERAND (arg1, 1)));
6221 if (flag_unsafe_math_optimizations)
6223 enum built_in_function fcode = builtin_mathfn_code (arg1);
6224 /* Optimize x/exp(y) into x*exp(-y). */
6225 if (fcode == BUILT_IN_EXP
6226 || fcode == BUILT_IN_EXPF
6227 || fcode == BUILT_IN_EXPL)
6229 tree expfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
6230 tree arg = build1 (NEGATE_EXPR, type,
6231 TREE_VALUE (TREE_OPERAND (arg1, 1)));
6232 tree arglist = build_tree_list (NULL_TREE, fold (arg));
6233 arg1 = build_function_call_expr (expfn, arglist);
6234 return fold (build (MULT_EXPR, type, arg0, arg1));
6237 /* Optimize x/pow(y,z) into x*pow(y,-z). */
6238 if (fcode == BUILT_IN_POW
6239 || fcode == BUILT_IN_POWF
6240 || fcode == BUILT_IN_POWL)
6242 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
6243 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
6244 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1, 1)));
6245 tree neg11 = fold (build1 (NEGATE_EXPR, type, arg11));
6246 tree arglist = tree_cons(NULL_TREE, arg10,
6247 build_tree_list (NULL_TREE, neg11));
6248 arg1 = build_function_call_expr (powfn, arglist);
6249 return fold (build (MULT_EXPR, type, arg0, arg1));
6253 if (flag_unsafe_math_optimizations)
6255 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
6256 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
6258 /* Optimize sin(x)/cos(x) as tan(x). */
6259 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_COS)
6260 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_COSF)
6261 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_COSL))
6262 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
6263 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
6267 if (fcode0 == BUILT_IN_SIN)
6268 tanfn = implicit_built_in_decls[BUILT_IN_TAN];
6269 else if (fcode0 == BUILT_IN_SINF)
6270 tanfn = implicit_built_in_decls[BUILT_IN_TANF];
6271 else if (fcode0 == BUILT_IN_SINL)
6272 tanfn = implicit_built_in_decls[BUILT_IN_TANL];
6276 if (tanfn != NULL_TREE)
6277 return build_function_call_expr (tanfn,
6278 TREE_OPERAND (arg0, 1));
6281 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
6282 if (((fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_SIN)
6283 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_SINF)
6284 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_SINL))
6285 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
6286 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
6290 if (fcode0 == BUILT_IN_COS)
6291 tanfn = implicit_built_in_decls[BUILT_IN_TAN];
6292 else if (fcode0 == BUILT_IN_COSF)
6293 tanfn = implicit_built_in_decls[BUILT_IN_TANF];
6294 else if (fcode0 == BUILT_IN_COSL)
6295 tanfn = implicit_built_in_decls[BUILT_IN_TANL];
6299 if (tanfn != NULL_TREE)
6301 tree tmp = TREE_OPERAND (arg0, 1);
6302 tmp = build_function_call_expr (tanfn, tmp);
6303 return fold (build (RDIV_EXPR, type,
6304 build_real (type, dconst1),
6311 case TRUNC_DIV_EXPR:
6312 case ROUND_DIV_EXPR:
6313 case FLOOR_DIV_EXPR:
6315 case EXACT_DIV_EXPR:
6316 if (integer_onep (arg1))
6317 return non_lvalue (convert (type, arg0));
6318 if (integer_zerop (arg1))
6321 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
6322 operation, EXACT_DIV_EXPR.
6324 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
6325 At one time others generated faster code, it's not clear if they do
6326 after the last round to changes to the DIV code in expmed.c. */
6327 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
6328 && multiple_of_p (type, arg0, arg1))
6329 return fold (build (EXACT_DIV_EXPR, type, arg0, arg1));
6331 if (TREE_CODE (arg1) == INTEGER_CST
6332 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
6334 return convert (type, tem);
6339 case FLOOR_MOD_EXPR:
6340 case ROUND_MOD_EXPR:
6341 case TRUNC_MOD_EXPR:
6342 if (integer_onep (arg1))
6343 return omit_one_operand (type, integer_zero_node, arg0);
6344 if (integer_zerop (arg1))
6347 if (TREE_CODE (arg1) == INTEGER_CST
6348 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
6350 return convert (type, tem);
6356 if (integer_all_onesp (arg0))
6357 return omit_one_operand (type, arg0, arg1);
6361 /* Optimize -1 >> x for arithmetic right shifts. */
6362 if (integer_all_onesp (arg0) && ! TREE_UNSIGNED (type))
6363 return omit_one_operand (type, arg0, arg1);
6364 /* ... fall through ... */
6368 if (integer_zerop (arg1))
6369 return non_lvalue (convert (type, arg0));
6370 if (integer_zerop (arg0))
6371 return omit_one_operand (type, arg0, arg1);
6373 /* Since negative shift count is not well-defined,
6374 don't try to compute it in the compiler. */
6375 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
6377 /* Rewrite an LROTATE_EXPR by a constant into an
6378 RROTATE_EXPR by a new constant. */
6379 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
6381 TREE_SET_CODE (t, RROTATE_EXPR);
6382 code = RROTATE_EXPR;
6383 TREE_OPERAND (t, 1) = arg1
6386 convert (TREE_TYPE (arg1),
6387 build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type)), 0)),
6389 if (tree_int_cst_sgn (arg1) < 0)
6393 /* If we have a rotate of a bit operation with the rotate count and
6394 the second operand of the bit operation both constant,
6395 permute the two operations. */
6396 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
6397 && (TREE_CODE (arg0) == BIT_AND_EXPR
6398 || TREE_CODE (arg0) == BIT_ANDTC_EXPR
6399 || TREE_CODE (arg0) == BIT_IOR_EXPR
6400 || TREE_CODE (arg0) == BIT_XOR_EXPR)
6401 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
6402 return fold (build (TREE_CODE (arg0), type,
6403 fold (build (code, type,
6404 TREE_OPERAND (arg0, 0), arg1)),
6405 fold (build (code, type,
6406 TREE_OPERAND (arg0, 1), arg1))));
6408 /* Two consecutive rotates adding up to the width of the mode can
6410 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
6411 && TREE_CODE (arg0) == RROTATE_EXPR
6412 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6413 && TREE_INT_CST_HIGH (arg1) == 0
6414 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
6415 && ((TREE_INT_CST_LOW (arg1)
6416 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
6417 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type))))
6418 return TREE_OPERAND (arg0, 0);
6423 if (operand_equal_p (arg0, arg1, 0))
6424 return omit_one_operand (type, arg0, arg1);
6425 if (INTEGRAL_TYPE_P (type)
6426 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), 1))
6427 return omit_one_operand (type, arg1, arg0);
6431 if (operand_equal_p (arg0, arg1, 0))
6432 return omit_one_operand (type, arg0, arg1);
6433 if (INTEGRAL_TYPE_P (type)
6434 && TYPE_MAX_VALUE (type)
6435 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), 1))
6436 return omit_one_operand (type, arg1, arg0);
6439 case TRUTH_NOT_EXPR:
6440 /* Note that the operand of this must be an int
6441 and its values must be 0 or 1.
6442 ("true" is a fixed value perhaps depending on the language,
6443 but we don't handle values other than 1 correctly yet.) */
6444 tem = invert_truthvalue (arg0);
6445 /* Avoid infinite recursion. */
6446 if (TREE_CODE (tem) == TRUTH_NOT_EXPR)
6448 tem = fold_single_bit_test (code, arg0, arg1, type);
6453 return convert (type, tem);
6455 case TRUTH_ANDIF_EXPR:
6456 /* Note that the operands of this must be ints
6457 and their values must be 0 or 1.
6458 ("true" is a fixed value perhaps depending on the language.) */
6459 /* If first arg is constant zero, return it. */
6460 if (integer_zerop (arg0))
6461 return convert (type, arg0);
6462 case TRUTH_AND_EXPR:
6463 /* If either arg is constant true, drop it. */
6464 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
6465 return non_lvalue (convert (type, arg1));
6466 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
6467 /* Preserve sequence points. */
6468 && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
6469 return non_lvalue (convert (type, arg0));
6470 /* If second arg is constant zero, result is zero, but first arg
6471 must be evaluated. */
6472 if (integer_zerop (arg1))
6473 return omit_one_operand (type, arg1, arg0);
6474 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
6475 case will be handled here. */
6476 if (integer_zerop (arg0))
6477 return omit_one_operand (type, arg0, arg1);
6480 /* We only do these simplifications if we are optimizing. */
6484 /* Check for things like (A || B) && (A || C). We can convert this
6485 to A || (B && C). Note that either operator can be any of the four
6486 truth and/or operations and the transformation will still be
6487 valid. Also note that we only care about order for the
6488 ANDIF and ORIF operators. If B contains side effects, this
6489 might change the truth-value of A. */
6490 if (TREE_CODE (arg0) == TREE_CODE (arg1)
6491 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
6492 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
6493 || TREE_CODE (arg0) == TRUTH_AND_EXPR
6494 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
6495 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
6497 tree a00 = TREE_OPERAND (arg0, 0);
6498 tree a01 = TREE_OPERAND (arg0, 1);
6499 tree a10 = TREE_OPERAND (arg1, 0);
6500 tree a11 = TREE_OPERAND (arg1, 1);
6501 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
6502 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
6503 && (code == TRUTH_AND_EXPR
6504 || code == TRUTH_OR_EXPR));
6506 if (operand_equal_p (a00, a10, 0))
6507 return fold (build (TREE_CODE (arg0), type, a00,
6508 fold (build (code, type, a01, a11))));
6509 else if (commutative && operand_equal_p (a00, a11, 0))
6510 return fold (build (TREE_CODE (arg0), type, a00,
6511 fold (build (code, type, a01, a10))));
6512 else if (commutative && operand_equal_p (a01, a10, 0))
6513 return fold (build (TREE_CODE (arg0), type, a01,
6514 fold (build (code, type, a00, a11))));
6516 /* This case if tricky because we must either have commutative
6517 operators or else A10 must not have side-effects. */
6519 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
6520 && operand_equal_p (a01, a11, 0))
6521 return fold (build (TREE_CODE (arg0), type,
6522 fold (build (code, type, a00, a10)),
6526 /* See if we can build a range comparison. */
6527 if (0 != (tem = fold_range_test (t)))
6530 /* Check for the possibility of merging component references. If our
6531 lhs is another similar operation, try to merge its rhs with our
6532 rhs. Then try to merge our lhs and rhs. */
6533 if (TREE_CODE (arg0) == code
6534 && 0 != (tem = fold_truthop (code, type,
6535 TREE_OPERAND (arg0, 1), arg1)))
6536 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6538 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
6543 case TRUTH_ORIF_EXPR:
6544 /* Note that the operands of this must be ints
6545 and their values must be 0 or true.
6546 ("true" is a fixed value perhaps depending on the language.) */
6547 /* If first arg is constant true, return it. */
6548 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
6549 return convert (type, arg0);
6551 /* If either arg is constant zero, drop it. */
6552 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
6553 return non_lvalue (convert (type, arg1));
6554 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
6555 /* Preserve sequence points. */
6556 && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
6557 return non_lvalue (convert (type, arg0));
6558 /* If second arg is constant true, result is true, but we must
6559 evaluate first arg. */
6560 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
6561 return omit_one_operand (type, arg1, arg0);
6562 /* Likewise for first arg, but note this only occurs here for
6564 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
6565 return omit_one_operand (type, arg0, arg1);
6568 case TRUTH_XOR_EXPR:
6569 /* If either arg is constant zero, drop it. */
6570 if (integer_zerop (arg0))
6571 return non_lvalue (convert (type, arg1));
6572 if (integer_zerop (arg1))
6573 return non_lvalue (convert (type, arg0));
6574 /* If either arg is constant true, this is a logical inversion. */
6575 if (integer_onep (arg0))
6576 return non_lvalue (convert (type, invert_truthvalue (arg1)));
6577 if (integer_onep (arg1))
6578 return non_lvalue (convert (type, invert_truthvalue (arg0)));
6587 /* If one arg is a real or integer constant, put it last. */
6588 if ((TREE_CODE (arg0) == INTEGER_CST
6589 && TREE_CODE (arg1) != INTEGER_CST)
6590 || (TREE_CODE (arg0) == REAL_CST
6591 && TREE_CODE (arg0) != REAL_CST))
6593 TREE_OPERAND (t, 0) = arg1;
6594 TREE_OPERAND (t, 1) = arg0;
6595 arg0 = TREE_OPERAND (t, 0);
6596 arg1 = TREE_OPERAND (t, 1);
6597 code = swap_tree_comparison (code);
6598 TREE_SET_CODE (t, code);
6601 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
6603 tree targ0 = strip_float_extensions (arg0);
6604 tree targ1 = strip_float_extensions (arg1);
6605 tree newtype = TREE_TYPE (targ0);
6607 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
6608 newtype = TREE_TYPE (targ1);
6610 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
6611 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
6612 return fold (build (code, type, convert (newtype, targ0),
6613 convert (newtype, targ1)));
6615 /* (-a) CMP (-b) -> b CMP a */
6616 if (TREE_CODE (arg0) == NEGATE_EXPR
6617 && TREE_CODE (arg1) == NEGATE_EXPR)
6618 return fold (build (code, type, TREE_OPERAND (arg1, 0),
6619 TREE_OPERAND (arg0, 0)));
6621 if (TREE_CODE (arg1) == REAL_CST)
6623 REAL_VALUE_TYPE cst;
6624 cst = TREE_REAL_CST (arg1);
6626 /* (-a) CMP CST -> a swap(CMP) (-CST) */
6627 if (TREE_CODE (arg0) == NEGATE_EXPR)
6629 fold (build (swap_tree_comparison (code), type,
6630 TREE_OPERAND (arg0, 0),
6631 build_real (TREE_TYPE (arg1),
6632 REAL_VALUE_NEGATE (cst))));
6634 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
6635 /* a CMP (-0) -> a CMP 0 */
6636 if (REAL_VALUE_MINUS_ZERO (cst))
6637 return fold (build (code, type, arg0,
6638 build_real (TREE_TYPE (arg1), dconst0)));
6640 /* x != NaN is always true, other ops are always false. */
6641 if (REAL_VALUE_ISNAN (cst)
6642 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))))
6644 t = (code == NE_EXPR) ? integer_one_node : integer_zero_node;
6645 return omit_one_operand (type, convert (type, t), arg0);
6648 /* Fold comparisons against infinity. */
6649 if (REAL_VALUE_ISINF (cst))
6651 tem = fold_inf_compare (code, type, arg0, arg1);
6652 if (tem != NULL_TREE)
6657 /* If this is a comparison of a real constant with a PLUS_EXPR
6658 or a MINUS_EXPR of a real constant, we can convert it into a
6659 comparison with a revised real constant as long as no overflow
6660 occurs when unsafe_math_optimizations are enabled. */
6661 if (flag_unsafe_math_optimizations
6662 && TREE_CODE (arg1) == REAL_CST
6663 && (TREE_CODE (arg0) == PLUS_EXPR
6664 || TREE_CODE (arg0) == MINUS_EXPR)
6665 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
6666 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
6667 ? MINUS_EXPR : PLUS_EXPR,
6668 arg1, TREE_OPERAND (arg0, 1), 0))
6669 && ! TREE_CONSTANT_OVERFLOW (tem))
6670 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6672 /* Likewise, we can simplify a comparison of a real constant with
6673 a MINUS_EXPR whose first operand is also a real constant, i.e.
6674 (c1 - x) < c2 becomes x > c1-c2. */
6675 if (flag_unsafe_math_optimizations
6676 && TREE_CODE (arg1) == REAL_CST
6677 && TREE_CODE (arg0) == MINUS_EXPR
6678 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST
6679 && 0 != (tem = const_binop (MINUS_EXPR, TREE_OPERAND (arg0, 0),
6681 && ! TREE_CONSTANT_OVERFLOW (tem))
6682 return fold (build (swap_tree_comparison (code), type,
6683 TREE_OPERAND (arg0, 1), tem));
6685 /* Fold comparisons against built-in math functions. */
6686 if (TREE_CODE (arg1) == REAL_CST
6687 && flag_unsafe_math_optimizations
6688 && ! flag_errno_math)
6690 enum built_in_function fcode = builtin_mathfn_code (arg0);
6692 if (fcode != END_BUILTINS)
6694 tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
6695 if (tem != NULL_TREE)
6701 /* Convert foo++ == CONST into ++foo == CONST + INCR.
6702 First, see if one arg is constant; find the constant arg
6703 and the other one. */
6705 tree constop = 0, varop = NULL_TREE;
6706 int constopnum = -1;
6708 if (TREE_CONSTANT (arg1))
6709 constopnum = 1, constop = arg1, varop = arg0;
6710 if (TREE_CONSTANT (arg0))
6711 constopnum = 0, constop = arg0, varop = arg1;
6713 if (constop && TREE_CODE (varop) == POSTINCREMENT_EXPR)
6715 /* This optimization is invalid for ordered comparisons
6716 if CONST+INCR overflows or if foo+incr might overflow.
6717 This optimization is invalid for floating point due to rounding.
6718 For pointer types we assume overflow doesn't happen. */
6719 if (POINTER_TYPE_P (TREE_TYPE (varop))
6720 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
6721 && (code == EQ_EXPR || code == NE_EXPR)))
6724 = fold (build (PLUS_EXPR, TREE_TYPE (varop),
6725 constop, TREE_OPERAND (varop, 1)));
6727 /* Do not overwrite the current varop to be a preincrement,
6728 create a new node so that we won't confuse our caller who
6729 might create trees and throw them away, reusing the
6730 arguments that they passed to build. This shows up in
6731 the THEN or ELSE parts of ?: being postincrements. */
6732 varop = build (PREINCREMENT_EXPR, TREE_TYPE (varop),
6733 TREE_OPERAND (varop, 0),
6734 TREE_OPERAND (varop, 1));
6736 /* If VAROP is a reference to a bitfield, we must mask
6737 the constant by the width of the field. */
6738 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
6739 && DECL_BIT_FIELD(TREE_OPERAND
6740 (TREE_OPERAND (varop, 0), 1)))
6743 = TREE_INT_CST_LOW (DECL_SIZE
6745 (TREE_OPERAND (varop, 0), 1)));
6746 tree mask, unsigned_type;
6747 unsigned int precision;
6748 tree folded_compare;
6750 /* First check whether the comparison would come out
6751 always the same. If we don't do that we would
6752 change the meaning with the masking. */
6753 if (constopnum == 0)
6754 folded_compare = fold (build (code, type, constop,
6755 TREE_OPERAND (varop, 0)));
6757 folded_compare = fold (build (code, type,
6758 TREE_OPERAND (varop, 0),
6760 if (integer_zerop (folded_compare)
6761 || integer_onep (folded_compare))
6762 return omit_one_operand (type, folded_compare, varop);
6764 unsigned_type = (*lang_hooks.types.type_for_size)(size, 1);
6765 precision = TYPE_PRECISION (unsigned_type);
6766 mask = build_int_2 (~0, ~0);
6767 TREE_TYPE (mask) = unsigned_type;
6768 force_fit_type (mask, 0);
6769 mask = const_binop (RSHIFT_EXPR, mask,
6770 size_int (precision - size), 0);
6771 newconst = fold (build (BIT_AND_EXPR,
6772 TREE_TYPE (varop), newconst,
6773 convert (TREE_TYPE (varop),
6777 t = build (code, type,
6778 (constopnum == 0) ? newconst : varop,
6779 (constopnum == 1) ? newconst : varop);
6783 else if (constop && TREE_CODE (varop) == POSTDECREMENT_EXPR)
6785 if (POINTER_TYPE_P (TREE_TYPE (varop))
6786 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
6787 && (code == EQ_EXPR || code == NE_EXPR)))
6790 = fold (build (MINUS_EXPR, TREE_TYPE (varop),
6791 constop, TREE_OPERAND (varop, 1)));
6793 /* Do not overwrite the current varop to be a predecrement,
6794 create a new node so that we won't confuse our caller who
6795 might create trees and throw them away, reusing the
6796 arguments that they passed to build. This shows up in
6797 the THEN or ELSE parts of ?: being postdecrements. */
6798 varop = build (PREDECREMENT_EXPR, TREE_TYPE (varop),
6799 TREE_OPERAND (varop, 0),
6800 TREE_OPERAND (varop, 1));
6802 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
6803 && DECL_BIT_FIELD(TREE_OPERAND
6804 (TREE_OPERAND (varop, 0), 1)))
6807 = TREE_INT_CST_LOW (DECL_SIZE
6809 (TREE_OPERAND (varop, 0), 1)));
6810 tree mask, unsigned_type;
6811 unsigned int precision;
6812 tree folded_compare;
6814 if (constopnum == 0)
6815 folded_compare = fold (build (code, type, constop,
6816 TREE_OPERAND (varop, 0)));
6818 folded_compare = fold (build (code, type,
6819 TREE_OPERAND (varop, 0),
6821 if (integer_zerop (folded_compare)
6822 || integer_onep (folded_compare))
6823 return omit_one_operand (type, folded_compare, varop);
6825 unsigned_type = (*lang_hooks.types.type_for_size)(size, 1);
6826 precision = TYPE_PRECISION (unsigned_type);
6827 mask = build_int_2 (~0, ~0);
6828 TREE_TYPE (mask) = TREE_TYPE (varop);
6829 force_fit_type (mask, 0);
6830 mask = const_binop (RSHIFT_EXPR, mask,
6831 size_int (precision - size), 0);
6832 newconst = fold (build (BIT_AND_EXPR,
6833 TREE_TYPE (varop), newconst,
6834 convert (TREE_TYPE (varop),
6838 t = build (code, type,
6839 (constopnum == 0) ? newconst : varop,
6840 (constopnum == 1) ? newconst : varop);
6846 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
6847 This transformation affects the cases which are handled in later
6848 optimizations involving comparisons with non-negative constants. */
6849 if (TREE_CODE (arg1) == INTEGER_CST
6850 && TREE_CODE (arg0) != INTEGER_CST
6851 && tree_int_cst_sgn (arg1) > 0)
6857 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6858 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6863 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6864 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6872 /* Comparisons with the highest or lowest possible integer of
6873 the specified size will have known values. */
6875 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1)));
6877 if (TREE_CODE (arg1) == INTEGER_CST
6878 && ! TREE_CONSTANT_OVERFLOW (arg1)
6879 && width <= HOST_BITS_PER_WIDE_INT
6880 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
6881 || POINTER_TYPE_P (TREE_TYPE (arg1))))
6883 unsigned HOST_WIDE_INT signed_max;
6884 unsigned HOST_WIDE_INT max, min;
6886 signed_max = ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1;
6888 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
6890 max = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
6896 min = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
6899 if (TREE_INT_CST_HIGH (arg1) == 0
6900 && TREE_INT_CST_LOW (arg1) == max)
6904 return omit_one_operand (type,
6905 convert (type, integer_zero_node),
6909 TREE_SET_CODE (t, EQ_EXPR);
6912 return omit_one_operand (type,
6913 convert (type, integer_one_node),
6917 TREE_SET_CODE (t, NE_EXPR);
6920 /* The GE_EXPR and LT_EXPR cases above are not normally
6921 reached because of previous transformations. */
6926 else if (TREE_INT_CST_HIGH (arg1) == 0
6927 && TREE_INT_CST_LOW (arg1) == max - 1)
6932 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
6933 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6937 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
6938 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6943 else if (TREE_INT_CST_HIGH (arg1) == (min ? -1 : 0)
6944 && TREE_INT_CST_LOW (arg1) == min)
6948 return omit_one_operand (type,
6949 convert (type, integer_zero_node),
6953 TREE_SET_CODE (t, EQ_EXPR);
6957 return omit_one_operand (type,
6958 convert (type, integer_one_node),
6962 TREE_SET_CODE (t, NE_EXPR);
6968 else if (TREE_INT_CST_HIGH (arg1) == (min ? -1 : 0)
6969 && TREE_INT_CST_LOW (arg1) == min + 1)
6974 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6975 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6979 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6980 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6986 else if (TREE_INT_CST_HIGH (arg1) == 0
6987 && TREE_INT_CST_LOW (arg1) == signed_max
6988 && TREE_UNSIGNED (TREE_TYPE (arg1))
6989 /* signed_type does not work on pointer types. */
6990 && INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
6992 /* The following case also applies to X < signed_max+1
6993 and X >= signed_max+1 because previous transformations. */
6994 if (code == LE_EXPR || code == GT_EXPR)
6997 st0 = (*lang_hooks.types.signed_type) (TREE_TYPE (arg0));
6998 st1 = (*lang_hooks.types.signed_type) (TREE_TYPE (arg1));
7000 (build (code == LE_EXPR ? GE_EXPR: LT_EXPR,
7001 type, convert (st0, arg0),
7002 convert (st1, integer_zero_node)));
7008 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
7009 a MINUS_EXPR of a constant, we can convert it into a comparison with
7010 a revised constant as long as no overflow occurs. */
7011 if ((code == EQ_EXPR || code == NE_EXPR)
7012 && TREE_CODE (arg1) == INTEGER_CST
7013 && (TREE_CODE (arg0) == PLUS_EXPR
7014 || TREE_CODE (arg0) == MINUS_EXPR)
7015 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7016 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
7017 ? MINUS_EXPR : PLUS_EXPR,
7018 arg1, TREE_OPERAND (arg0, 1), 0))
7019 && ! TREE_CONSTANT_OVERFLOW (tem))
7020 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
7022 /* Similarly for a NEGATE_EXPR. */
7023 else if ((code == EQ_EXPR || code == NE_EXPR)
7024 && TREE_CODE (arg0) == NEGATE_EXPR
7025 && TREE_CODE (arg1) == INTEGER_CST
7026 && 0 != (tem = negate_expr (arg1))
7027 && TREE_CODE (tem) == INTEGER_CST
7028 && ! TREE_CONSTANT_OVERFLOW (tem))
7029 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
7031 /* If we have X - Y == 0, we can convert that to X == Y and similarly
7032 for !=. Don't do this for ordered comparisons due to overflow. */
7033 else if ((code == NE_EXPR || code == EQ_EXPR)
7034 && integer_zerop (arg1) && TREE_CODE (arg0) == MINUS_EXPR)
7035 return fold (build (code, type,
7036 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1)));
7038 /* If we are widening one operand of an integer comparison,
7039 see if the other operand is similarly being widened. Perhaps we
7040 can do the comparison in the narrower type. */
7041 else if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
7042 && TREE_CODE (arg0) == NOP_EXPR
7043 && (tem = get_unwidened (arg0, NULL_TREE)) != arg0
7044 && (t1 = get_unwidened (arg1, TREE_TYPE (tem))) != 0
7045 && (TREE_TYPE (t1) == TREE_TYPE (tem)
7046 || (TREE_CODE (t1) == INTEGER_CST
7047 && int_fits_type_p (t1, TREE_TYPE (tem)))))
7048 return fold (build (code, type, tem, convert (TREE_TYPE (tem), t1)));
7050 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
7051 constant, we can simplify it. */
7052 else if (TREE_CODE (arg1) == INTEGER_CST
7053 && (TREE_CODE (arg0) == MIN_EXPR
7054 || TREE_CODE (arg0) == MAX_EXPR)
7055 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
7056 return optimize_minmax_comparison (t);
7058 /* If we are comparing an ABS_EXPR with a constant, we can
7059 convert all the cases into explicit comparisons, but they may
7060 well not be faster than doing the ABS and one comparison.
7061 But ABS (X) <= C is a range comparison, which becomes a subtraction
7062 and a comparison, and is probably faster. */
7063 else if (code == LE_EXPR && TREE_CODE (arg1) == INTEGER_CST
7064 && TREE_CODE (arg0) == ABS_EXPR
7065 && ! TREE_SIDE_EFFECTS (arg0)
7066 && (0 != (tem = negate_expr (arg1)))
7067 && TREE_CODE (tem) == INTEGER_CST
7068 && ! TREE_CONSTANT_OVERFLOW (tem))
7069 return fold (build (TRUTH_ANDIF_EXPR, type,
7070 build (GE_EXPR, type, TREE_OPERAND (arg0, 0), tem),
7071 build (LE_EXPR, type,
7072 TREE_OPERAND (arg0, 0), arg1)));
7074 /* If this is an EQ or NE comparison with zero and ARG0 is
7075 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
7076 two operations, but the latter can be done in one less insn
7077 on machines that have only two-operand insns or on which a
7078 constant cannot be the first operand. */
7079 if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR)
7080 && TREE_CODE (arg0) == BIT_AND_EXPR)
7082 if (TREE_CODE (TREE_OPERAND (arg0, 0)) == LSHIFT_EXPR
7083 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 0), 0)))
7085 fold (build (code, type,
7086 build (BIT_AND_EXPR, TREE_TYPE (arg0),
7088 TREE_TYPE (TREE_OPERAND (arg0, 0)),
7089 TREE_OPERAND (arg0, 1),
7090 TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)),
7091 convert (TREE_TYPE (arg0),
7094 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
7095 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
7097 fold (build (code, type,
7098 build (BIT_AND_EXPR, TREE_TYPE (arg0),
7100 TREE_TYPE (TREE_OPERAND (arg0, 1)),
7101 TREE_OPERAND (arg0, 0),
7102 TREE_OPERAND (TREE_OPERAND (arg0, 1), 1)),
7103 convert (TREE_TYPE (arg0),
7108 /* If this is an NE or EQ comparison of zero against the result of a
7109 signed MOD operation whose second operand is a power of 2, make
7110 the MOD operation unsigned since it is simpler and equivalent. */
7111 if ((code == NE_EXPR || code == EQ_EXPR)
7112 && integer_zerop (arg1)
7113 && ! TREE_UNSIGNED (TREE_TYPE (arg0))
7114 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
7115 || TREE_CODE (arg0) == CEIL_MOD_EXPR
7116 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
7117 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
7118 && integer_pow2p (TREE_OPERAND (arg0, 1)))
7120 tree newtype = (*lang_hooks.types.unsigned_type) (TREE_TYPE (arg0));
7121 tree newmod = build (TREE_CODE (arg0), newtype,
7122 convert (newtype, TREE_OPERAND (arg0, 0)),
7123 convert (newtype, TREE_OPERAND (arg0, 1)));
7125 return build (code, type, newmod, convert (newtype, arg1));
7128 /* If this is an NE comparison of zero with an AND of one, remove the
7129 comparison since the AND will give the correct value. */
7130 if (code == NE_EXPR && integer_zerop (arg1)
7131 && TREE_CODE (arg0) == BIT_AND_EXPR
7132 && integer_onep (TREE_OPERAND (arg0, 1)))
7133 return convert (type, arg0);
7135 /* If we have (A & C) == C where C is a power of 2, convert this into
7136 (A & C) != 0. Similarly for NE_EXPR. */
7137 if ((code == EQ_EXPR || code == NE_EXPR)
7138 && TREE_CODE (arg0) == BIT_AND_EXPR
7139 && integer_pow2p (TREE_OPERAND (arg0, 1))
7140 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
7141 return fold (build (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
7142 arg0, integer_zero_node));
7144 /* If we have (A & C) != 0 or (A & C) == 0 and C is a power of
7145 2, then fold the expression into shifts and logical operations. */
7146 tem = fold_single_bit_test (code, arg0, arg1, type);
7150 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
7151 and similarly for >= into !=. */
7152 if ((code == LT_EXPR || code == GE_EXPR)
7153 && TREE_UNSIGNED (TREE_TYPE (arg0))
7154 && TREE_CODE (arg1) == LSHIFT_EXPR
7155 && integer_onep (TREE_OPERAND (arg1, 0)))
7156 return build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
7157 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
7158 TREE_OPERAND (arg1, 1)),
7159 convert (TREE_TYPE (arg0), integer_zero_node));
7161 else if ((code == LT_EXPR || code == GE_EXPR)
7162 && TREE_UNSIGNED (TREE_TYPE (arg0))
7163 && (TREE_CODE (arg1) == NOP_EXPR
7164 || TREE_CODE (arg1) == CONVERT_EXPR)
7165 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
7166 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
7168 build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
7169 convert (TREE_TYPE (arg0),
7170 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
7171 TREE_OPERAND (TREE_OPERAND (arg1, 0), 1))),
7172 convert (TREE_TYPE (arg0), integer_zero_node));
7174 /* Simplify comparison of something with itself. (For IEEE
7175 floating-point, we can only do some of these simplifications.) */
7176 if (operand_equal_p (arg0, arg1, 0))
7183 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
7184 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
7185 return constant_boolean_node (1, type);
7187 TREE_SET_CODE (t, code);
7191 /* For NE, we can only do this simplification if integer
7192 or we don't honor IEEE floating point NaNs. */
7193 if (FLOAT_TYPE_P (TREE_TYPE (arg0))
7194 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
7196 /* ... fall through ... */
7199 return constant_boolean_node (0, type);
7205 /* If we are comparing an expression that just has comparisons
7206 of two integer values, arithmetic expressions of those comparisons,
7207 and constants, we can simplify it. There are only three cases
7208 to check: the two values can either be equal, the first can be
7209 greater, or the second can be greater. Fold the expression for
7210 those three values. Since each value must be 0 or 1, we have
7211 eight possibilities, each of which corresponds to the constant 0
7212 or 1 or one of the six possible comparisons.
7214 This handles common cases like (a > b) == 0 but also handles
7215 expressions like ((x > y) - (y > x)) > 0, which supposedly
7216 occur in macroized code. */
7218 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
7220 tree cval1 = 0, cval2 = 0;
7223 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
7224 /* Don't handle degenerate cases here; they should already
7225 have been handled anyway. */
7226 && cval1 != 0 && cval2 != 0
7227 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
7228 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
7229 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
7230 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
7231 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
7232 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
7233 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
7235 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
7236 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
7238 /* We can't just pass T to eval_subst in case cval1 or cval2
7239 was the same as ARG1. */
7242 = fold (build (code, type,
7243 eval_subst (arg0, cval1, maxval, cval2, minval),
7246 = fold (build (code, type,
7247 eval_subst (arg0, cval1, maxval, cval2, maxval),
7250 = fold (build (code, type,
7251 eval_subst (arg0, cval1, minval, cval2, maxval),
7254 /* All three of these results should be 0 or 1. Confirm they
7255 are. Then use those values to select the proper code
7258 if ((integer_zerop (high_result)
7259 || integer_onep (high_result))
7260 && (integer_zerop (equal_result)
7261 || integer_onep (equal_result))
7262 && (integer_zerop (low_result)
7263 || integer_onep (low_result)))
7265 /* Make a 3-bit mask with the high-order bit being the
7266 value for `>', the next for '=', and the low for '<'. */
7267 switch ((integer_onep (high_result) * 4)
7268 + (integer_onep (equal_result) * 2)
7269 + integer_onep (low_result))
7273 return omit_one_operand (type, integer_zero_node, arg0);
7294 return omit_one_operand (type, integer_one_node, arg0);
7297 t = build (code, type, cval1, cval2);
7299 return save_expr (t);
7306 /* If this is a comparison of a field, we may be able to simplify it. */
7307 if (((TREE_CODE (arg0) == COMPONENT_REF
7308 && (*lang_hooks.can_use_bit_fields_p) ())
7309 || TREE_CODE (arg0) == BIT_FIELD_REF)
7310 && (code == EQ_EXPR || code == NE_EXPR)
7311 /* Handle the constant case even without -O
7312 to make sure the warnings are given. */
7313 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
7315 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
7319 /* If this is a comparison of complex values and either or both sides
7320 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
7321 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
7322 This may prevent needless evaluations. */
7323 if ((code == EQ_EXPR || code == NE_EXPR)
7324 && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
7325 && (TREE_CODE (arg0) == COMPLEX_EXPR
7326 || TREE_CODE (arg1) == COMPLEX_EXPR
7327 || TREE_CODE (arg0) == COMPLEX_CST
7328 || TREE_CODE (arg1) == COMPLEX_CST))
7330 tree subtype = TREE_TYPE (TREE_TYPE (arg0));
7331 tree real0, imag0, real1, imag1;
7333 arg0 = save_expr (arg0);
7334 arg1 = save_expr (arg1);
7335 real0 = fold (build1 (REALPART_EXPR, subtype, arg0));
7336 imag0 = fold (build1 (IMAGPART_EXPR, subtype, arg0));
7337 real1 = fold (build1 (REALPART_EXPR, subtype, arg1));
7338 imag1 = fold (build1 (IMAGPART_EXPR, subtype, arg1));
7340 return fold (build ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR
7343 fold (build (code, type, real0, real1)),
7344 fold (build (code, type, imag0, imag1))));
7347 /* Optimize comparisons of strlen vs zero to a compare of the
7348 first character of the string vs zero. To wit,
7349 strlen(ptr) == 0 => *ptr == 0
7350 strlen(ptr) != 0 => *ptr != 0
7351 Other cases should reduce to one of these two (or a constant)
7352 due to the return value of strlen being unsigned. */
7353 if ((code == EQ_EXPR || code == NE_EXPR)
7354 && integer_zerop (arg1)
7355 && TREE_CODE (arg0) == CALL_EXPR
7356 && TREE_CODE (TREE_OPERAND (arg0, 0)) == ADDR_EXPR)
7358 tree fndecl = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7361 if (TREE_CODE (fndecl) == FUNCTION_DECL
7362 && DECL_BUILT_IN (fndecl)
7363 && DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_MD
7364 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
7365 && (arglist = TREE_OPERAND (arg0, 1))
7366 && TREE_CODE (TREE_TYPE (TREE_VALUE (arglist))) == POINTER_TYPE
7367 && ! TREE_CHAIN (arglist))
7368 return fold (build (code, type,
7369 build1 (INDIRECT_REF, char_type_node,
7370 TREE_VALUE(arglist)),
7371 integer_zero_node));
7374 /* From here on, the only cases we handle are when the result is
7375 known to be a constant.
7377 To compute GT, swap the arguments and do LT.
7378 To compute GE, do LT and invert the result.
7379 To compute LE, swap the arguments, do LT and invert the result.
7380 To compute NE, do EQ and invert the result.
7382 Therefore, the code below must handle only EQ and LT. */
7384 if (code == LE_EXPR || code == GT_EXPR)
7386 tem = arg0, arg0 = arg1, arg1 = tem;
7387 code = swap_tree_comparison (code);
7390 /* Note that it is safe to invert for real values here because we
7391 will check below in the one case that it matters. */
7395 if (code == NE_EXPR || code == GE_EXPR)
7398 code = invert_tree_comparison (code);
7401 /* Compute a result for LT or EQ if args permit;
7402 otherwise return T. */
7403 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
7405 if (code == EQ_EXPR)
7406 t1 = build_int_2 (tree_int_cst_equal (arg0, arg1), 0);
7408 t1 = build_int_2 ((TREE_UNSIGNED (TREE_TYPE (arg0))
7409 ? INT_CST_LT_UNSIGNED (arg0, arg1)
7410 : INT_CST_LT (arg0, arg1)),
7414 #if 0 /* This is no longer useful, but breaks some real code. */
7415 /* Assume a nonexplicit constant cannot equal an explicit one,
7416 since such code would be undefined anyway.
7417 Exception: on sysvr4, using #pragma weak,
7418 a label can come out as 0. */
7419 else if (TREE_CODE (arg1) == INTEGER_CST
7420 && !integer_zerop (arg1)
7421 && TREE_CONSTANT (arg0)
7422 && TREE_CODE (arg0) == ADDR_EXPR
7424 t1 = build_int_2 (0, 0);
7426 /* Two real constants can be compared explicitly. */
7427 else if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
7429 /* If either operand is a NaN, the result is false with two
7430 exceptions: First, an NE_EXPR is true on NaNs, but that case
7431 is already handled correctly since we will be inverting the
7432 result for NE_EXPR. Second, if we had inverted a LE_EXPR
7433 or a GE_EXPR into a LT_EXPR, we must return true so that it
7434 will be inverted into false. */
7436 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
7437 || REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
7438 t1 = build_int_2 (invert && code == LT_EXPR, 0);
7440 else if (code == EQ_EXPR)
7441 t1 = build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (arg0),
7442 TREE_REAL_CST (arg1)),
7445 t1 = build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (arg0),
7446 TREE_REAL_CST (arg1)),
7450 if (t1 == NULL_TREE)
7454 TREE_INT_CST_LOW (t1) ^= 1;
7456 TREE_TYPE (t1) = type;
7457 if (TREE_CODE (type) == BOOLEAN_TYPE)
7458 return (*lang_hooks.truthvalue_conversion) (t1);
7462 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
7463 so all simple results must be passed through pedantic_non_lvalue. */
7464 if (TREE_CODE (arg0) == INTEGER_CST)
7465 return pedantic_non_lvalue
7466 (TREE_OPERAND (t, (integer_zerop (arg0) ? 2 : 1)));
7467 else if (operand_equal_p (arg1, TREE_OPERAND (expr, 2), 0))
7468 return pedantic_omit_one_operand (type, arg1, arg0);
7470 /* If the second operand is zero, invert the comparison and swap
7471 the second and third operands. Likewise if the second operand
7472 is constant and the third is not or if the third operand is
7473 equivalent to the first operand of the comparison. */
7475 if (integer_zerop (arg1)
7476 || (TREE_CONSTANT (arg1) && ! TREE_CONSTANT (TREE_OPERAND (t, 2)))
7477 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
7478 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
7479 TREE_OPERAND (t, 2),
7480 TREE_OPERAND (arg0, 1))))
7482 /* See if this can be inverted. If it can't, possibly because
7483 it was a floating-point inequality comparison, don't do
7485 tem = invert_truthvalue (arg0);
7487 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
7489 t = build (code, type, tem,
7490 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
7492 /* arg1 should be the first argument of the new T. */
7493 arg1 = TREE_OPERAND (t, 1);
7498 /* If we have A op B ? A : C, we may be able to convert this to a
7499 simpler expression, depending on the operation and the values
7500 of B and C. Signed zeros prevent all of these transformations,
7501 for reasons given above each one. */
7503 if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
7504 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
7505 arg1, TREE_OPERAND (arg0, 1))
7506 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
7508 tree arg2 = TREE_OPERAND (t, 2);
7509 enum tree_code comp_code = TREE_CODE (arg0);
7513 /* If we have A op 0 ? A : -A, consider applying the following
7516 A == 0? A : -A same as -A
7517 A != 0? A : -A same as A
7518 A >= 0? A : -A same as abs (A)
7519 A > 0? A : -A same as abs (A)
7520 A <= 0? A : -A same as -abs (A)
7521 A < 0? A : -A same as -abs (A)
7523 None of these transformations work for modes with signed
7524 zeros. If A is +/-0, the first two transformations will
7525 change the sign of the result (from +0 to -0, or vice
7526 versa). The last four will fix the sign of the result,
7527 even though the original expressions could be positive or
7528 negative, depending on the sign of A.
7530 Note that all these transformations are correct if A is
7531 NaN, since the two alternatives (A and -A) are also NaNs. */
7532 if ((FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 1)))
7533 ? real_zerop (TREE_OPERAND (arg0, 1))
7534 : integer_zerop (TREE_OPERAND (arg0, 1)))
7535 && TREE_CODE (arg2) == NEGATE_EXPR
7536 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
7544 (convert (TREE_TYPE (TREE_OPERAND (t, 1)),
7547 return pedantic_non_lvalue (convert (type, arg1));
7550 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
7551 arg1 = convert ((*lang_hooks.types.signed_type)
7552 (TREE_TYPE (arg1)), arg1);
7553 return pedantic_non_lvalue
7554 (convert (type, fold (build1 (ABS_EXPR,
7555 TREE_TYPE (arg1), arg1))));
7558 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
7559 arg1 = convert ((lang_hooks.types.signed_type)
7560 (TREE_TYPE (arg1)), arg1);
7561 return pedantic_non_lvalue
7562 (negate_expr (convert (type,
7563 fold (build1 (ABS_EXPR,
7570 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
7571 A == 0 ? A : 0 is always 0 unless A is -0. Note that
7572 both transformations are correct when A is NaN: A != 0
7573 is then true, and A == 0 is false. */
7575 if (integer_zerop (TREE_OPERAND (arg0, 1)) && integer_zerop (arg2))
7577 if (comp_code == NE_EXPR)
7578 return pedantic_non_lvalue (convert (type, arg1));
7579 else if (comp_code == EQ_EXPR)
7580 return pedantic_non_lvalue (convert (type, integer_zero_node));
7583 /* Try some transformations of A op B ? A : B.
7585 A == B? A : B same as B
7586 A != B? A : B same as A
7587 A >= B? A : B same as max (A, B)
7588 A > B? A : B same as max (B, A)
7589 A <= B? A : B same as min (A, B)
7590 A < B? A : B same as min (B, A)
7592 As above, these transformations don't work in the presence
7593 of signed zeros. For example, if A and B are zeros of
7594 opposite sign, the first two transformations will change
7595 the sign of the result. In the last four, the original
7596 expressions give different results for (A=+0, B=-0) and
7597 (A=-0, B=+0), but the transformed expressions do not.
7599 The first two transformations are correct if either A or B
7600 is a NaN. In the first transformation, the condition will
7601 be false, and B will indeed be chosen. In the case of the
7602 second transformation, the condition A != B will be true,
7603 and A will be chosen.
7605 The conversions to max() and min() are not correct if B is
7606 a number and A is not. The conditions in the original
7607 expressions will be false, so all four give B. The min()
7608 and max() versions would give a NaN instead. */
7609 if (operand_equal_for_comparison_p (TREE_OPERAND (arg0, 1),
7610 arg2, TREE_OPERAND (arg0, 0)))
7612 tree comp_op0 = TREE_OPERAND (arg0, 0);
7613 tree comp_op1 = TREE_OPERAND (arg0, 1);
7614 tree comp_type = TREE_TYPE (comp_op0);
7616 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
7617 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
7627 return pedantic_non_lvalue (convert (type, arg2));
7629 return pedantic_non_lvalue (convert (type, arg1));
7632 /* In C++ a ?: expression can be an lvalue, so put the
7633 operand which will be used if they are equal first
7634 so that we can convert this back to the
7635 corresponding COND_EXPR. */
7636 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
7637 return pedantic_non_lvalue
7638 (convert (type, fold (build (MIN_EXPR, comp_type,
7639 (comp_code == LE_EXPR
7640 ? comp_op0 : comp_op1),
7641 (comp_code == LE_EXPR
7642 ? comp_op1 : comp_op0)))));
7646 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
7647 return pedantic_non_lvalue
7648 (convert (type, fold (build (MAX_EXPR, comp_type,
7649 (comp_code == GE_EXPR
7650 ? comp_op0 : comp_op1),
7651 (comp_code == GE_EXPR
7652 ? comp_op1 : comp_op0)))));
7659 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
7660 we might still be able to simplify this. For example,
7661 if C1 is one less or one more than C2, this might have started
7662 out as a MIN or MAX and been transformed by this function.
7663 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
7665 if (INTEGRAL_TYPE_P (type)
7666 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7667 && TREE_CODE (arg2) == INTEGER_CST)
7671 /* We can replace A with C1 in this case. */
7672 arg1 = convert (type, TREE_OPERAND (arg0, 1));
7673 t = build (code, type, TREE_OPERAND (t, 0), arg1,
7674 TREE_OPERAND (t, 2));
7678 /* If C1 is C2 + 1, this is min(A, C2). */
7679 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
7680 && operand_equal_p (TREE_OPERAND (arg0, 1),
7681 const_binop (PLUS_EXPR, arg2,
7682 integer_one_node, 0), 1))
7683 return pedantic_non_lvalue
7684 (fold (build (MIN_EXPR, type, arg1, arg2)));
7688 /* If C1 is C2 - 1, this is min(A, C2). */
7689 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
7690 && operand_equal_p (TREE_OPERAND (arg0, 1),
7691 const_binop (MINUS_EXPR, arg2,
7692 integer_one_node, 0), 1))
7693 return pedantic_non_lvalue
7694 (fold (build (MIN_EXPR, type, arg1, arg2)));
7698 /* If C1 is C2 - 1, this is max(A, C2). */
7699 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
7700 && operand_equal_p (TREE_OPERAND (arg0, 1),
7701 const_binop (MINUS_EXPR, arg2,
7702 integer_one_node, 0), 1))
7703 return pedantic_non_lvalue
7704 (fold (build (MAX_EXPR, type, arg1, arg2)));
7708 /* If C1 is C2 + 1, this is max(A, C2). */
7709 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
7710 && operand_equal_p (TREE_OPERAND (arg0, 1),
7711 const_binop (PLUS_EXPR, arg2,
7712 integer_one_node, 0), 1))
7713 return pedantic_non_lvalue
7714 (fold (build (MAX_EXPR, type, arg1, arg2)));
7723 /* If the second operand is simpler than the third, swap them
7724 since that produces better jump optimization results. */
7725 if ((TREE_CONSTANT (arg1) || DECL_P (arg1)
7726 || TREE_CODE (arg1) == SAVE_EXPR)
7727 && ! (TREE_CONSTANT (TREE_OPERAND (t, 2))
7728 || DECL_P (TREE_OPERAND (t, 2))
7729 || TREE_CODE (TREE_OPERAND (t, 2)) == SAVE_EXPR))
7731 /* See if this can be inverted. If it can't, possibly because
7732 it was a floating-point inequality comparison, don't do
7734 tem = invert_truthvalue (arg0);
7736 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
7738 t = build (code, type, tem,
7739 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
7741 /* arg1 should be the first argument of the new T. */
7742 arg1 = TREE_OPERAND (t, 1);
7747 /* Convert A ? 1 : 0 to simply A. */
7748 if (integer_onep (TREE_OPERAND (t, 1))
7749 && integer_zerop (TREE_OPERAND (t, 2))
7750 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
7751 call to fold will try to move the conversion inside
7752 a COND, which will recurse. In that case, the COND_EXPR
7753 is probably the best choice, so leave it alone. */
7754 && type == TREE_TYPE (arg0))
7755 return pedantic_non_lvalue (arg0);
7757 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
7758 over COND_EXPR in cases such as floating point comparisons. */
7759 if (integer_zerop (TREE_OPERAND (t, 1))
7760 && integer_onep (TREE_OPERAND (t, 2))
7761 && truth_value_p (TREE_CODE (arg0)))
7762 return pedantic_non_lvalue (convert (type,
7763 invert_truthvalue (arg0)));
7765 /* Look for expressions of the form A & 2 ? 2 : 0. The result of this
7766 operation is simply A & 2. */
7768 if (integer_zerop (TREE_OPERAND (t, 2))
7769 && TREE_CODE (arg0) == NE_EXPR
7770 && integer_zerop (TREE_OPERAND (arg0, 1))
7771 && integer_pow2p (arg1)
7772 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
7773 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
7775 return pedantic_non_lvalue (convert (type, TREE_OPERAND (arg0, 0)));
7777 /* Convert A ? B : 0 into A && B if A and B are truth values. */
7778 if (integer_zerop (TREE_OPERAND (t, 2))
7779 && truth_value_p (TREE_CODE (arg0))
7780 && truth_value_p (TREE_CODE (arg1)))
7781 return pedantic_non_lvalue (fold (build (TRUTH_ANDIF_EXPR, type,
7784 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
7785 if (integer_onep (TREE_OPERAND (t, 2))
7786 && truth_value_p (TREE_CODE (arg0))
7787 && truth_value_p (TREE_CODE (arg1)))
7789 /* Only perform transformation if ARG0 is easily inverted. */
7790 tem = invert_truthvalue (arg0);
7791 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
7792 return pedantic_non_lvalue (fold (build (TRUTH_ORIF_EXPR, type,
7799 /* When pedantic, a compound expression can be neither an lvalue
7800 nor an integer constant expression. */
7801 if (TREE_SIDE_EFFECTS (arg0) || pedantic)
7803 /* Don't let (0, 0) be null pointer constant. */
7804 if (integer_zerop (arg1))
7805 return build1 (NOP_EXPR, type, arg1);
7806 return convert (type, arg1);
7810 return build_complex (type, arg0, arg1);
7814 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7816 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
7817 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
7818 TREE_OPERAND (arg0, 1));
7819 else if (TREE_CODE (arg0) == COMPLEX_CST)
7820 return TREE_REALPART (arg0);
7821 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7822 return fold (build (TREE_CODE (arg0), type,
7823 fold (build1 (REALPART_EXPR, type,
7824 TREE_OPERAND (arg0, 0))),
7825 fold (build1 (REALPART_EXPR,
7826 type, TREE_OPERAND (arg0, 1)))));
7830 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7831 return convert (type, integer_zero_node);
7832 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
7833 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
7834 TREE_OPERAND (arg0, 0));
7835 else if (TREE_CODE (arg0) == COMPLEX_CST)
7836 return TREE_IMAGPART (arg0);
7837 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7838 return fold (build (TREE_CODE (arg0), type,
7839 fold (build1 (IMAGPART_EXPR, type,
7840 TREE_OPERAND (arg0, 0))),
7841 fold (build1 (IMAGPART_EXPR, type,
7842 TREE_OPERAND (arg0, 1)))));
7845 /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
7847 case CLEANUP_POINT_EXPR:
7848 if (! has_cleanups (arg0))
7849 return TREE_OPERAND (t, 0);
7852 enum tree_code code0 = TREE_CODE (arg0);
7853 int kind0 = TREE_CODE_CLASS (code0);
7854 tree arg00 = TREE_OPERAND (arg0, 0);
7857 if (kind0 == '1' || code0 == TRUTH_NOT_EXPR)
7858 return fold (build1 (code0, type,
7859 fold (build1 (CLEANUP_POINT_EXPR,
7860 TREE_TYPE (arg00), arg00))));
7862 if (kind0 == '<' || kind0 == '2'
7863 || code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR
7864 || code0 == TRUTH_AND_EXPR || code0 == TRUTH_OR_EXPR
7865 || code0 == TRUTH_XOR_EXPR)
7867 arg01 = TREE_OPERAND (arg0, 1);
7869 if (TREE_CONSTANT (arg00)
7870 || ((code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR)
7871 && ! has_cleanups (arg00)))
7872 return fold (build (code0, type, arg00,
7873 fold (build1 (CLEANUP_POINT_EXPR,
7874 TREE_TYPE (arg01), arg01))));
7876 if (TREE_CONSTANT (arg01))
7877 return fold (build (code0, type,
7878 fold (build1 (CLEANUP_POINT_EXPR,
7879 TREE_TYPE (arg00), arg00)),
7887 /* Check for a built-in function. */
7888 if (TREE_CODE (TREE_OPERAND (expr, 0)) == ADDR_EXPR
7889 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (expr, 0), 0))
7891 && DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (expr, 0), 0)))
7893 tree tmp = fold_builtin (expr);
7901 } /* switch (code) */
7904 /* Perform constant folding and related simplification of intializer
7905 expression EXPR. This behaves identically to "fold" but ignores
7906 potential run-time traps and exceptions that fold must preserve. */
7909 fold_initializer (tree expr)
7911 int saved_signaling_nans = flag_signaling_nans;
7912 int saved_trapping_math = flag_trapping_math;
7913 int saved_trapv = flag_trapv;
7916 flag_signaling_nans = 0;
7917 flag_trapping_math = 0;
7920 result = fold (expr);
7922 flag_signaling_nans = saved_signaling_nans;
7923 flag_trapping_math = saved_trapping_math;
7924 flag_trapv = saved_trapv;
7929 /* Determine if first argument is a multiple of second argument. Return 0 if
7930 it is not, or we cannot easily determined it to be.
7932 An example of the sort of thing we care about (at this point; this routine
7933 could surely be made more general, and expanded to do what the *_DIV_EXPR's
7934 fold cases do now) is discovering that
7936 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7942 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
7944 This code also handles discovering that
7946 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7948 is a multiple of 8 so we don't have to worry about dealing with a
7951 Note that we *look* inside a SAVE_EXPR only to determine how it was
7952 calculated; it is not safe for fold to do much of anything else with the
7953 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
7954 at run time. For example, the latter example above *cannot* be implemented
7955 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
7956 evaluation time of the original SAVE_EXPR is not necessarily the same at
7957 the time the new expression is evaluated. The only optimization of this
7958 sort that would be valid is changing
7960 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
7964 SAVE_EXPR (I) * SAVE_EXPR (J)
7966 (where the same SAVE_EXPR (J) is used in the original and the
7967 transformed version). */
7970 multiple_of_p (tree type, tree top, tree bottom)
7972 if (operand_equal_p (top, bottom, 0))
7975 if (TREE_CODE (type) != INTEGER_TYPE)
7978 switch (TREE_CODE (top))
7981 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
7982 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
7986 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
7987 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
7990 if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
7994 op1 = TREE_OPERAND (top, 1);
7995 /* const_binop may not detect overflow correctly,
7996 so check for it explicitly here. */
7997 if (TYPE_PRECISION (TREE_TYPE (size_one_node))
7998 > TREE_INT_CST_LOW (op1)
7999 && TREE_INT_CST_HIGH (op1) == 0
8000 && 0 != (t1 = convert (type,
8001 const_binop (LSHIFT_EXPR, size_one_node,
8003 && ! TREE_OVERFLOW (t1))
8004 return multiple_of_p (type, t1, bottom);
8009 /* Can't handle conversions from non-integral or wider integral type. */
8010 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
8011 || (TYPE_PRECISION (type)
8012 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
8015 /* .. fall through ... */
8018 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
8021 if (TREE_CODE (bottom) != INTEGER_CST
8022 || (TREE_UNSIGNED (type)
8023 && (tree_int_cst_sgn (top) < 0
8024 || tree_int_cst_sgn (bottom) < 0)))
8026 return integer_zerop (const_binop (TRUNC_MOD_EXPR,
8034 /* Return true if `t' is known to be non-negative. */
8037 tree_expr_nonnegative_p (tree t)
8039 switch (TREE_CODE (t))
8049 /* These are undefined at zero. This is true even if
8050 C[LT]Z_DEFINED_VALUE_AT_ZERO is set, since what we're
8051 computing here is a user-visible property. */
8055 return tree_int_cst_sgn (t) >= 0;
8058 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
8061 if (FLOAT_TYPE_P (TREE_TYPE (t)))
8062 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8063 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8065 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
8066 both unsigned and at least 2 bits shorter than the result. */
8067 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
8068 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
8069 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
8071 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
8072 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
8073 if (TREE_CODE (inner1) == INTEGER_TYPE && TREE_UNSIGNED (inner1)
8074 && TREE_CODE (inner2) == INTEGER_TYPE && TREE_UNSIGNED (inner2))
8076 unsigned int prec = MAX (TYPE_PRECISION (inner1),
8077 TYPE_PRECISION (inner2)) + 1;
8078 return prec < TYPE_PRECISION (TREE_TYPE (t));
8084 if (FLOAT_TYPE_P (TREE_TYPE (t)))
8086 /* x * x for floating point x is always non-negative. */
8087 if (operand_equal_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1), 0))
8089 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8090 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8093 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
8094 both unsigned and their total bits is shorter than the result. */
8095 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
8096 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
8097 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
8099 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
8100 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
8101 if (TREE_CODE (inner1) == INTEGER_TYPE && TREE_UNSIGNED (inner1)
8102 && TREE_CODE (inner2) == INTEGER_TYPE && TREE_UNSIGNED (inner2))
8103 return TYPE_PRECISION (inner1) + TYPE_PRECISION (inner2)
8104 < TYPE_PRECISION (TREE_TYPE (t));
8108 case TRUNC_DIV_EXPR:
8110 case FLOOR_DIV_EXPR:
8111 case ROUND_DIV_EXPR:
8112 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8113 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8115 case TRUNC_MOD_EXPR:
8117 case FLOOR_MOD_EXPR:
8118 case ROUND_MOD_EXPR:
8119 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8122 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8123 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8127 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
8128 tree outer_type = TREE_TYPE (t);
8130 if (TREE_CODE (outer_type) == REAL_TYPE)
8132 if (TREE_CODE (inner_type) == REAL_TYPE)
8133 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8134 if (TREE_CODE (inner_type) == INTEGER_TYPE)
8136 if (TREE_UNSIGNED (inner_type))
8138 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8141 else if (TREE_CODE (outer_type) == INTEGER_TYPE)
8143 if (TREE_CODE (inner_type) == REAL_TYPE)
8144 return tree_expr_nonnegative_p (TREE_OPERAND (t,0));
8145 if (TREE_CODE (inner_type) == INTEGER_TYPE)
8146 return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
8147 && TREE_UNSIGNED (inner_type);
8153 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
8154 && tree_expr_nonnegative_p (TREE_OPERAND (t, 2));
8156 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8158 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8159 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8161 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8162 || tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8164 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8166 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8168 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8169 case NON_LVALUE_EXPR:
8170 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8172 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8174 return rtl_expr_nonnegative_p (RTL_EXPR_RTL (t));
8177 if (TREE_CODE (TREE_OPERAND (t, 0)) == ADDR_EXPR)
8179 tree fndecl = TREE_OPERAND (TREE_OPERAND (t, 0), 0);
8180 tree arglist = TREE_OPERAND (t, 1);
8181 if (TREE_CODE (fndecl) == FUNCTION_DECL
8182 && DECL_BUILT_IN (fndecl)
8183 && DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_MD)
8184 switch (DECL_FUNCTION_CODE (fndecl))
8187 case BUILT_IN_CABSL:
8188 case BUILT_IN_CABSF:
8193 case BUILT_IN_FABSF:
8194 case BUILT_IN_FABSL:
8196 case BUILT_IN_SQRTF:
8197 case BUILT_IN_SQRTL:
8201 case BUILT_IN_ATANF:
8202 case BUILT_IN_ATANL:
8204 case BUILT_IN_CEILF:
8205 case BUILT_IN_CEILL:
8206 case BUILT_IN_FLOOR:
8207 case BUILT_IN_FLOORF:
8208 case BUILT_IN_FLOORL:
8209 case BUILT_IN_NEARBYINT:
8210 case BUILT_IN_NEARBYINTF:
8211 case BUILT_IN_NEARBYINTL:
8212 case BUILT_IN_ROUND:
8213 case BUILT_IN_ROUNDF:
8214 case BUILT_IN_ROUNDL:
8215 case BUILT_IN_TRUNC:
8216 case BUILT_IN_TRUNCF:
8217 case BUILT_IN_TRUNCL:
8218 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
8223 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
8230 /* ... fall through ... */
8233 if (truth_value_p (TREE_CODE (t)))
8234 /* Truth values evaluate to 0 or 1, which is nonnegative. */
8238 /* We don't know sign of `t', so be conservative and return false. */
8242 /* Return true if `r' is known to be non-negative.
8243 Only handles constants at the moment. */
8246 rtl_expr_nonnegative_p (rtx r)
8248 switch (GET_CODE (r))
8251 return INTVAL (r) >= 0;
8254 if (GET_MODE (r) == VOIDmode)
8255 return CONST_DOUBLE_HIGH (r) >= 0;
8263 units = CONST_VECTOR_NUNITS (r);
8265 for (i = 0; i < units; ++i)
8267 elt = CONST_VECTOR_ELT (r, i);
8268 if (!rtl_expr_nonnegative_p (elt))
8277 /* These are always nonnegative. */
8285 #include "gt-fold-const.h"