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 ((char *) 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 ((char *) quo, 0, sizeof quo);
596 memset ((char *) num, 0, sizeof num); /* to zero 9th element */
597 memset ((char *) 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)
1233 REAL_VALUE_TYPE value;
1236 d1 = TREE_REAL_CST (arg1);
1237 d2 = TREE_REAL_CST (arg2);
1239 /* If either operand is a NaN, just return it. Otherwise, set up
1240 for floating-point trap; we return an overflow. */
1241 if (REAL_VALUE_ISNAN (d1))
1243 else if (REAL_VALUE_ISNAN (d2))
1246 REAL_ARITHMETIC (value, code, d1, d2);
1248 t = build_real (TREE_TYPE (arg1),
1249 real_value_truncate (TYPE_MODE (TREE_TYPE (arg1)),
1253 = (force_fit_type (t, 0)
1254 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
1255 TREE_CONSTANT_OVERFLOW (t)
1257 | TREE_CONSTANT_OVERFLOW (arg1)
1258 | TREE_CONSTANT_OVERFLOW (arg2);
1261 if (TREE_CODE (arg1) == COMPLEX_CST)
1263 tree type = TREE_TYPE (arg1);
1264 tree r1 = TREE_REALPART (arg1);
1265 tree i1 = TREE_IMAGPART (arg1);
1266 tree r2 = TREE_REALPART (arg2);
1267 tree i2 = TREE_IMAGPART (arg2);
1273 t = build_complex (type,
1274 const_binop (PLUS_EXPR, r1, r2, notrunc),
1275 const_binop (PLUS_EXPR, i1, i2, notrunc));
1279 t = build_complex (type,
1280 const_binop (MINUS_EXPR, r1, r2, notrunc),
1281 const_binop (MINUS_EXPR, i1, i2, notrunc));
1285 t = build_complex (type,
1286 const_binop (MINUS_EXPR,
1287 const_binop (MULT_EXPR,
1289 const_binop (MULT_EXPR,
1292 const_binop (PLUS_EXPR,
1293 const_binop (MULT_EXPR,
1295 const_binop (MULT_EXPR,
1303 = const_binop (PLUS_EXPR,
1304 const_binop (MULT_EXPR, r2, r2, notrunc),
1305 const_binop (MULT_EXPR, i2, i2, notrunc),
1308 t = build_complex (type,
1310 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1311 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1312 const_binop (PLUS_EXPR,
1313 const_binop (MULT_EXPR, r1, r2,
1315 const_binop (MULT_EXPR, i1, i2,
1318 magsquared, notrunc),
1320 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1321 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1322 const_binop (MINUS_EXPR,
1323 const_binop (MULT_EXPR, i1, r2,
1325 const_binop (MULT_EXPR, r1, i2,
1328 magsquared, notrunc));
1340 /* These are the hash table functions for the hash table of INTEGER_CST
1341 nodes of a sizetype. */
1343 /* Return the hash code code X, an INTEGER_CST. */
1346 size_htab_hash (const void *x)
1350 return (TREE_INT_CST_HIGH (t) ^ TREE_INT_CST_LOW (t)
1351 ^ htab_hash_pointer (TREE_TYPE (t))
1352 ^ (TREE_OVERFLOW (t) << 20));
1355 /* Return nonzero if the value represented by *X (an INTEGER_CST tree node)
1356 is the same as that given by *Y, which is the same. */
1359 size_htab_eq (const void *x, const void *y)
1364 return (TREE_INT_CST_HIGH (xt) == TREE_INT_CST_HIGH (yt)
1365 && TREE_INT_CST_LOW (xt) == TREE_INT_CST_LOW (yt)
1366 && TREE_TYPE (xt) == TREE_TYPE (yt)
1367 && TREE_OVERFLOW (xt) == TREE_OVERFLOW (yt));
1370 /* Return an INTEGER_CST with value whose low-order HOST_BITS_PER_WIDE_INT
1371 bits are given by NUMBER and of the sizetype represented by KIND. */
1374 size_int_wide (HOST_WIDE_INT number, enum size_type_kind kind)
1376 return size_int_type_wide (number, sizetype_tab[(int) kind]);
1379 /* Likewise, but the desired type is specified explicitly. */
1381 static GTY (()) tree new_const;
1382 static GTY ((if_marked ("ggc_marked_p"), param_is (union tree_node)))
1386 size_int_type_wide (HOST_WIDE_INT number, tree type)
1392 size_htab = htab_create_ggc (1024, size_htab_hash, size_htab_eq, NULL);
1393 new_const = make_node (INTEGER_CST);
1396 /* Adjust NEW_CONST to be the constant we want. If it's already in the
1397 hash table, we return the value from the hash table. Otherwise, we
1398 place that in the hash table and make a new node for the next time. */
1399 TREE_INT_CST_LOW (new_const) = number;
1400 TREE_INT_CST_HIGH (new_const) = number < 0 ? -1 : 0;
1401 TREE_TYPE (new_const) = type;
1402 TREE_OVERFLOW (new_const) = TREE_CONSTANT_OVERFLOW (new_const)
1403 = force_fit_type (new_const, 0);
1405 slot = htab_find_slot (size_htab, new_const, INSERT);
1411 new_const = make_node (INTEGER_CST);
1415 return (tree) *slot;
1418 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1419 is a tree code. The type of the result is taken from the operands.
1420 Both must be the same type integer type and it must be a size type.
1421 If the operands are constant, so is the result. */
1424 size_binop (enum tree_code code, tree arg0, tree arg1)
1426 tree type = TREE_TYPE (arg0);
1428 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1429 || type != TREE_TYPE (arg1))
1432 /* Handle the special case of two integer constants faster. */
1433 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1435 /* And some specific cases even faster than that. */
1436 if (code == PLUS_EXPR && integer_zerop (arg0))
1438 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1439 && integer_zerop (arg1))
1441 else if (code == MULT_EXPR && integer_onep (arg0))
1444 /* Handle general case of two integer constants. */
1445 return int_const_binop (code, arg0, arg1, 0);
1448 if (arg0 == error_mark_node || arg1 == error_mark_node)
1449 return error_mark_node;
1451 return fold (build (code, type, arg0, arg1));
1454 /* Given two values, either both of sizetype or both of bitsizetype,
1455 compute the difference between the two values. Return the value
1456 in signed type corresponding to the type of the operands. */
1459 size_diffop (tree arg0, tree arg1)
1461 tree type = TREE_TYPE (arg0);
1464 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1465 || type != TREE_TYPE (arg1))
1468 /* If the type is already signed, just do the simple thing. */
1469 if (! TREE_UNSIGNED (type))
1470 return size_binop (MINUS_EXPR, arg0, arg1);
1472 ctype = (type == bitsizetype || type == ubitsizetype
1473 ? sbitsizetype : ssizetype);
1475 /* If either operand is not a constant, do the conversions to the signed
1476 type and subtract. The hardware will do the right thing with any
1477 overflow in the subtraction. */
1478 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
1479 return size_binop (MINUS_EXPR, convert (ctype, arg0),
1480 convert (ctype, arg1));
1482 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
1483 Otherwise, subtract the other way, convert to CTYPE (we know that can't
1484 overflow) and negate (which can't either). Special-case a result
1485 of zero while we're here. */
1486 if (tree_int_cst_equal (arg0, arg1))
1487 return convert (ctype, integer_zero_node);
1488 else if (tree_int_cst_lt (arg1, arg0))
1489 return convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
1491 return size_binop (MINUS_EXPR, convert (ctype, integer_zero_node),
1492 convert (ctype, size_binop (MINUS_EXPR, arg1, arg0)));
1496 /* Given T, a tree representing type conversion of ARG1, a constant,
1497 return a constant tree representing the result of conversion. */
1500 fold_convert (tree t, tree arg1)
1502 tree type = TREE_TYPE (t);
1505 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
1507 if (TREE_CODE (arg1) == INTEGER_CST)
1509 /* If we would build a constant wider than GCC supports,
1510 leave the conversion unfolded. */
1511 if (TYPE_PRECISION (type) > 2 * HOST_BITS_PER_WIDE_INT)
1514 /* If we are trying to make a sizetype for a small integer, use
1515 size_int to pick up cached types to reduce duplicate nodes. */
1516 if (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type)
1517 && !TREE_CONSTANT_OVERFLOW (arg1)
1518 && compare_tree_int (arg1, 10000) < 0)
1519 return size_int_type_wide (TREE_INT_CST_LOW (arg1), type);
1521 /* Given an integer constant, make new constant with new type,
1522 appropriately sign-extended or truncated. */
1523 t = build_int_2 (TREE_INT_CST_LOW (arg1),
1524 TREE_INT_CST_HIGH (arg1));
1525 TREE_TYPE (t) = type;
1526 /* Indicate an overflow if (1) ARG1 already overflowed,
1527 or (2) force_fit_type indicates an overflow.
1528 Tell force_fit_type that an overflow has already occurred
1529 if ARG1 is a too-large unsigned value and T is signed.
1530 But don't indicate an overflow if converting a pointer. */
1532 = ((force_fit_type (t,
1533 (TREE_INT_CST_HIGH (arg1) < 0
1534 && (TREE_UNSIGNED (type)
1535 < TREE_UNSIGNED (TREE_TYPE (arg1)))))
1536 && ! POINTER_TYPE_P (TREE_TYPE (arg1)))
1537 || TREE_OVERFLOW (arg1));
1538 TREE_CONSTANT_OVERFLOW (t)
1539 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1541 else if (TREE_CODE (arg1) == REAL_CST)
1543 /* Don't initialize these, use assignments.
1544 Initialized local aggregates don't work on old compilers. */
1548 tree type1 = TREE_TYPE (arg1);
1551 x = TREE_REAL_CST (arg1);
1552 l = real_value_from_int_cst (type1, TYPE_MIN_VALUE (type));
1554 no_upper_bound = (TYPE_MAX_VALUE (type) == NULL);
1555 if (!no_upper_bound)
1556 u = real_value_from_int_cst (type1, TYPE_MAX_VALUE (type));
1558 /* See if X will be in range after truncation towards 0.
1559 To compensate for truncation, move the bounds away from 0,
1560 but reject if X exactly equals the adjusted bounds. */
1561 REAL_ARITHMETIC (l, MINUS_EXPR, l, dconst1);
1562 if (!no_upper_bound)
1563 REAL_ARITHMETIC (u, PLUS_EXPR, u, dconst1);
1564 /* If X is a NaN, use zero instead and show we have an overflow.
1565 Otherwise, range check. */
1566 if (REAL_VALUE_ISNAN (x))
1567 overflow = 1, x = dconst0;
1568 else if (! (REAL_VALUES_LESS (l, x)
1570 && REAL_VALUES_LESS (x, u)))
1574 HOST_WIDE_INT low, high;
1575 REAL_VALUE_TO_INT (&low, &high, x);
1576 t = build_int_2 (low, high);
1578 TREE_TYPE (t) = type;
1580 = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
1581 TREE_CONSTANT_OVERFLOW (t)
1582 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1584 TREE_TYPE (t) = type;
1586 else if (TREE_CODE (type) == REAL_TYPE)
1588 if (TREE_CODE (arg1) == INTEGER_CST)
1589 return build_real_from_int_cst (type, arg1);
1590 if (TREE_CODE (arg1) == REAL_CST)
1592 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
1594 /* We make a copy of ARG1 so that we don't modify an
1595 existing constant tree. */
1596 t = copy_node (arg1);
1597 TREE_TYPE (t) = type;
1601 t = build_real (type,
1602 real_value_truncate (TYPE_MODE (type),
1603 TREE_REAL_CST (arg1)));
1606 = TREE_OVERFLOW (arg1) | force_fit_type (t, 0);
1607 TREE_CONSTANT_OVERFLOW (t)
1608 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1612 TREE_CONSTANT (t) = 1;
1616 /* Return an expr equal to X but certainly not valid as an lvalue. */
1623 /* These things are certainly not lvalues. */
1624 if (TREE_CODE (x) == NON_LVALUE_EXPR
1625 || TREE_CODE (x) == INTEGER_CST
1626 || TREE_CODE (x) == REAL_CST
1627 || TREE_CODE (x) == STRING_CST
1628 || TREE_CODE (x) == ADDR_EXPR)
1631 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
1632 TREE_CONSTANT (result) = TREE_CONSTANT (x);
1636 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
1637 Zero means allow extended lvalues. */
1639 int pedantic_lvalues;
1641 /* When pedantic, return an expr equal to X but certainly not valid as a
1642 pedantic lvalue. Otherwise, return X. */
1645 pedantic_non_lvalue (tree x)
1647 if (pedantic_lvalues)
1648 return non_lvalue (x);
1653 /* Given a tree comparison code, return the code that is the logical inverse
1654 of the given code. It is not safe to do this for floating-point
1655 comparisons, except for NE_EXPR and EQ_EXPR. */
1657 static enum tree_code
1658 invert_tree_comparison (enum tree_code code)
1679 /* Similar, but return the comparison that results if the operands are
1680 swapped. This is safe for floating-point. */
1682 static enum tree_code
1683 swap_tree_comparison (enum tree_code code)
1704 /* Convert a comparison tree code from an enum tree_code representation
1705 into a compcode bit-based encoding. This function is the inverse of
1706 compcode_to_comparison. */
1709 comparison_to_compcode (enum tree_code code)
1730 /* Convert a compcode bit-based encoding of a comparison operator back
1731 to GCC's enum tree_code representation. This function is the
1732 inverse of comparison_to_compcode. */
1734 static enum tree_code
1735 compcode_to_comparison (int code)
1756 /* Return nonzero if CODE is a tree code that represents a truth value. */
1759 truth_value_p (enum tree_code code)
1761 return (TREE_CODE_CLASS (code) == '<'
1762 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
1763 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
1764 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
1767 /* Return nonzero if two operands are necessarily equal.
1768 If ONLY_CONST is nonzero, only return nonzero for constants.
1769 This function tests whether the operands are indistinguishable;
1770 it does not test whether they are equal using C's == operation.
1771 The distinction is important for IEEE floating point, because
1772 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
1773 (2) two NaNs may be indistinguishable, but NaN!=NaN. */
1776 operand_equal_p (tree arg0, tree arg1, int only_const)
1778 /* If both types don't have the same signedness, then we can't consider
1779 them equal. We must check this before the STRIP_NOPS calls
1780 because they may change the signedness of the arguments. */
1781 if (TREE_UNSIGNED (TREE_TYPE (arg0)) != TREE_UNSIGNED (TREE_TYPE (arg1)))
1787 if (TREE_CODE (arg0) != TREE_CODE (arg1)
1788 /* This is needed for conversions and for COMPONENT_REF.
1789 Might as well play it safe and always test this. */
1790 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
1791 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
1792 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
1795 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
1796 We don't care about side effects in that case because the SAVE_EXPR
1797 takes care of that for us. In all other cases, two expressions are
1798 equal if they have no side effects. If we have two identical
1799 expressions with side effects that should be treated the same due
1800 to the only side effects being identical SAVE_EXPR's, that will
1801 be detected in the recursive calls below. */
1802 if (arg0 == arg1 && ! only_const
1803 && (TREE_CODE (arg0) == SAVE_EXPR
1804 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
1807 /* Next handle constant cases, those for which we can return 1 even
1808 if ONLY_CONST is set. */
1809 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
1810 switch (TREE_CODE (arg0))
1813 return (! TREE_CONSTANT_OVERFLOW (arg0)
1814 && ! TREE_CONSTANT_OVERFLOW (arg1)
1815 && tree_int_cst_equal (arg0, arg1));
1818 return (! TREE_CONSTANT_OVERFLOW (arg0)
1819 && ! TREE_CONSTANT_OVERFLOW (arg1)
1820 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
1821 TREE_REAL_CST (arg1)));
1827 if (TREE_CONSTANT_OVERFLOW (arg0)
1828 || TREE_CONSTANT_OVERFLOW (arg1))
1831 v1 = TREE_VECTOR_CST_ELTS (arg0);
1832 v2 = TREE_VECTOR_CST_ELTS (arg1);
1835 if (!operand_equal_p (v1, v2, only_const))
1837 v1 = TREE_CHAIN (v1);
1838 v2 = TREE_CHAIN (v2);
1845 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
1847 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
1851 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
1852 && ! memcmp (TREE_STRING_POINTER (arg0),
1853 TREE_STRING_POINTER (arg1),
1854 TREE_STRING_LENGTH (arg0)));
1857 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
1866 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
1869 /* Two conversions are equal only if signedness and modes match. */
1870 if ((TREE_CODE (arg0) == NOP_EXPR || TREE_CODE (arg0) == CONVERT_EXPR)
1871 && (TREE_UNSIGNED (TREE_TYPE (arg0))
1872 != TREE_UNSIGNED (TREE_TYPE (arg1))))
1875 return operand_equal_p (TREE_OPERAND (arg0, 0),
1876 TREE_OPERAND (arg1, 0), 0);
1880 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0)
1881 && operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1),
1885 /* For commutative ops, allow the other order. */
1886 return ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MULT_EXPR
1887 || TREE_CODE (arg0) == MIN_EXPR || TREE_CODE (arg0) == MAX_EXPR
1888 || TREE_CODE (arg0) == BIT_IOR_EXPR
1889 || TREE_CODE (arg0) == BIT_XOR_EXPR
1890 || TREE_CODE (arg0) == BIT_AND_EXPR
1891 || TREE_CODE (arg0) == NE_EXPR || TREE_CODE (arg0) == EQ_EXPR)
1892 && operand_equal_p (TREE_OPERAND (arg0, 0),
1893 TREE_OPERAND (arg1, 1), 0)
1894 && operand_equal_p (TREE_OPERAND (arg0, 1),
1895 TREE_OPERAND (arg1, 0), 0));
1898 /* If either of the pointer (or reference) expressions we are
1899 dereferencing contain a side effect, these cannot be equal. */
1900 if (TREE_SIDE_EFFECTS (arg0)
1901 || TREE_SIDE_EFFECTS (arg1))
1904 switch (TREE_CODE (arg0))
1907 return operand_equal_p (TREE_OPERAND (arg0, 0),
1908 TREE_OPERAND (arg1, 0), 0);
1912 case ARRAY_RANGE_REF:
1913 return (operand_equal_p (TREE_OPERAND (arg0, 0),
1914 TREE_OPERAND (arg1, 0), 0)
1915 && operand_equal_p (TREE_OPERAND (arg0, 1),
1916 TREE_OPERAND (arg1, 1), 0));
1919 return (operand_equal_p (TREE_OPERAND (arg0, 0),
1920 TREE_OPERAND (arg1, 0), 0)
1921 && operand_equal_p (TREE_OPERAND (arg0, 1),
1922 TREE_OPERAND (arg1, 1), 0)
1923 && operand_equal_p (TREE_OPERAND (arg0, 2),
1924 TREE_OPERAND (arg1, 2), 0));
1930 switch (TREE_CODE (arg0))
1933 case TRUTH_NOT_EXPR:
1934 return operand_equal_p (TREE_OPERAND (arg0, 0),
1935 TREE_OPERAND (arg1, 0), 0);
1938 return rtx_equal_p (RTL_EXPR_RTL (arg0), RTL_EXPR_RTL (arg1));
1941 /* If the CALL_EXPRs call different functions, then they
1942 clearly can not be equal. */
1943 if (! operand_equal_p (TREE_OPERAND (arg0, 0),
1944 TREE_OPERAND (arg1, 0), 0))
1947 /* Only consider const functions equivalent. */
1948 if (TREE_CODE (TREE_OPERAND (arg0, 0)) == ADDR_EXPR)
1950 tree fndecl = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
1951 if (! (flags_from_decl_or_type (fndecl) & ECF_CONST))
1957 /* Now see if all the arguments are the same. operand_equal_p
1958 does not handle TREE_LIST, so we walk the operands here
1959 feeding them to operand_equal_p. */
1960 arg0 = TREE_OPERAND (arg0, 1);
1961 arg1 = TREE_OPERAND (arg1, 1);
1962 while (arg0 && arg1)
1964 if (! operand_equal_p (TREE_VALUE (arg0), TREE_VALUE (arg1), 0))
1967 arg0 = TREE_CHAIN (arg0);
1968 arg1 = TREE_CHAIN (arg1);
1971 /* If we get here and both argument lists are exhausted
1972 then the CALL_EXPRs are equal. */
1973 return ! (arg0 || arg1);
1980 /* Consider __builtin_sqrt equal to sqrt. */
1981 return TREE_CODE (arg0) == FUNCTION_DECL
1982 && DECL_BUILT_IN (arg0) && DECL_BUILT_IN (arg1)
1983 && DECL_BUILT_IN_CLASS (arg0) == DECL_BUILT_IN_CLASS (arg1)
1984 && DECL_FUNCTION_CODE (arg0) == DECL_FUNCTION_CODE (arg1);
1991 /* Similar to operand_equal_p, but see if ARG0 might have been made by
1992 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
1994 When in doubt, return 0. */
1997 operand_equal_for_comparison_p (tree arg0, tree arg1, tree other)
1999 int unsignedp1, unsignedpo;
2000 tree primarg0, primarg1, primother;
2001 unsigned int correct_width;
2003 if (operand_equal_p (arg0, arg1, 0))
2006 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
2007 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
2010 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2011 and see if the inner values are the same. This removes any
2012 signedness comparison, which doesn't matter here. */
2013 primarg0 = arg0, primarg1 = arg1;
2014 STRIP_NOPS (primarg0);
2015 STRIP_NOPS (primarg1);
2016 if (operand_equal_p (primarg0, primarg1, 0))
2019 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2020 actual comparison operand, ARG0.
2022 First throw away any conversions to wider types
2023 already present in the operands. */
2025 primarg1 = get_narrower (arg1, &unsignedp1);
2026 primother = get_narrower (other, &unsignedpo);
2028 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
2029 if (unsignedp1 == unsignedpo
2030 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
2031 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
2033 tree type = TREE_TYPE (arg0);
2035 /* Make sure shorter operand is extended the right way
2036 to match the longer operand. */
2037 primarg1 = convert ((*lang_hooks.types.signed_or_unsigned_type)
2038 (unsignedp1, TREE_TYPE (primarg1)), primarg1);
2040 if (operand_equal_p (arg0, convert (type, primarg1), 0))
2047 /* See if ARG is an expression that is either a comparison or is performing
2048 arithmetic on comparisons. The comparisons must only be comparing
2049 two different values, which will be stored in *CVAL1 and *CVAL2; if
2050 they are nonzero it means that some operands have already been found.
2051 No variables may be used anywhere else in the expression except in the
2052 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2053 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2055 If this is true, return 1. Otherwise, return zero. */
2058 twoval_comparison_p (tree arg, tree *cval1, tree *cval2, int *save_p)
2060 enum tree_code code = TREE_CODE (arg);
2061 char class = TREE_CODE_CLASS (code);
2063 /* We can handle some of the 'e' cases here. */
2064 if (class == 'e' && code == TRUTH_NOT_EXPR)
2066 else if (class == 'e'
2067 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
2068 || code == COMPOUND_EXPR))
2071 else if (class == 'e' && code == SAVE_EXPR && SAVE_EXPR_RTL (arg) == 0
2072 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
2074 /* If we've already found a CVAL1 or CVAL2, this expression is
2075 two complex to handle. */
2076 if (*cval1 || *cval2)
2086 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
2089 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
2090 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2091 cval1, cval2, save_p));
2097 if (code == COND_EXPR)
2098 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
2099 cval1, cval2, save_p)
2100 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2101 cval1, cval2, save_p)
2102 && twoval_comparison_p (TREE_OPERAND (arg, 2),
2103 cval1, cval2, save_p));
2107 /* First see if we can handle the first operand, then the second. For
2108 the second operand, we know *CVAL1 can't be zero. It must be that
2109 one side of the comparison is each of the values; test for the
2110 case where this isn't true by failing if the two operands
2113 if (operand_equal_p (TREE_OPERAND (arg, 0),
2114 TREE_OPERAND (arg, 1), 0))
2118 *cval1 = TREE_OPERAND (arg, 0);
2119 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
2121 else if (*cval2 == 0)
2122 *cval2 = TREE_OPERAND (arg, 0);
2123 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
2128 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
2130 else if (*cval2 == 0)
2131 *cval2 = TREE_OPERAND (arg, 1);
2132 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
2144 /* ARG is a tree that is known to contain just arithmetic operations and
2145 comparisons. Evaluate the operations in the tree substituting NEW0 for
2146 any occurrence of OLD0 as an operand of a comparison and likewise for
2150 eval_subst (tree arg, tree old0, tree new0, tree old1, tree new1)
2152 tree type = TREE_TYPE (arg);
2153 enum tree_code code = TREE_CODE (arg);
2154 char class = TREE_CODE_CLASS (code);
2156 /* We can handle some of the 'e' cases here. */
2157 if (class == 'e' && code == TRUTH_NOT_EXPR)
2159 else if (class == 'e'
2160 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2166 return fold (build1 (code, type,
2167 eval_subst (TREE_OPERAND (arg, 0),
2168 old0, new0, old1, new1)));
2171 return fold (build (code, type,
2172 eval_subst (TREE_OPERAND (arg, 0),
2173 old0, new0, old1, new1),
2174 eval_subst (TREE_OPERAND (arg, 1),
2175 old0, new0, old1, new1)));
2181 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
2184 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
2187 return fold (build (code, type,
2188 eval_subst (TREE_OPERAND (arg, 0),
2189 old0, new0, old1, new1),
2190 eval_subst (TREE_OPERAND (arg, 1),
2191 old0, new0, old1, new1),
2192 eval_subst (TREE_OPERAND (arg, 2),
2193 old0, new0, old1, new1)));
2197 /* fall through - ??? */
2201 tree arg0 = TREE_OPERAND (arg, 0);
2202 tree arg1 = TREE_OPERAND (arg, 1);
2204 /* We need to check both for exact equality and tree equality. The
2205 former will be true if the operand has a side-effect. In that
2206 case, we know the operand occurred exactly once. */
2208 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
2210 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
2213 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
2215 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
2218 return fold (build (code, type, arg0, arg1));
2226 /* Return a tree for the case when the result of an expression is RESULT
2227 converted to TYPE and OMITTED was previously an operand of the expression
2228 but is now not needed (e.g., we folded OMITTED * 0).
2230 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2231 the conversion of RESULT to TYPE. */
2234 omit_one_operand (tree type, tree result, tree omitted)
2236 tree t = convert (type, result);
2238 if (TREE_SIDE_EFFECTS (omitted))
2239 return build (COMPOUND_EXPR, type, omitted, t);
2241 return non_lvalue (t);
2244 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2247 pedantic_omit_one_operand (tree type, tree result, tree omitted)
2249 tree t = convert (type, result);
2251 if (TREE_SIDE_EFFECTS (omitted))
2252 return build (COMPOUND_EXPR, type, omitted, t);
2254 return pedantic_non_lvalue (t);
2257 /* Return a simplified tree node for the truth-negation of ARG. This
2258 never alters ARG itself. We assume that ARG is an operation that
2259 returns a truth value (0 or 1). */
2262 invert_truthvalue (tree arg)
2264 tree type = TREE_TYPE (arg);
2265 enum tree_code code = TREE_CODE (arg);
2267 if (code == ERROR_MARK)
2270 /* If this is a comparison, we can simply invert it, except for
2271 floating-point non-equality comparisons, in which case we just
2272 enclose a TRUTH_NOT_EXPR around what we have. */
2274 if (TREE_CODE_CLASS (code) == '<')
2276 if (FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg, 0)))
2277 && !flag_unsafe_math_optimizations
2280 return build1 (TRUTH_NOT_EXPR, type, arg);
2282 return build (invert_tree_comparison (code), type,
2283 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
2289 return convert (type, build_int_2 (integer_zerop (arg), 0));
2291 case TRUTH_AND_EXPR:
2292 return build (TRUTH_OR_EXPR, type,
2293 invert_truthvalue (TREE_OPERAND (arg, 0)),
2294 invert_truthvalue (TREE_OPERAND (arg, 1)));
2297 return build (TRUTH_AND_EXPR, type,
2298 invert_truthvalue (TREE_OPERAND (arg, 0)),
2299 invert_truthvalue (TREE_OPERAND (arg, 1)));
2301 case TRUTH_XOR_EXPR:
2302 /* Here we can invert either operand. We invert the first operand
2303 unless the second operand is a TRUTH_NOT_EXPR in which case our
2304 result is the XOR of the first operand with the inside of the
2305 negation of the second operand. */
2307 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
2308 return build (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
2309 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
2311 return build (TRUTH_XOR_EXPR, type,
2312 invert_truthvalue (TREE_OPERAND (arg, 0)),
2313 TREE_OPERAND (arg, 1));
2315 case TRUTH_ANDIF_EXPR:
2316 return build (TRUTH_ORIF_EXPR, type,
2317 invert_truthvalue (TREE_OPERAND (arg, 0)),
2318 invert_truthvalue (TREE_OPERAND (arg, 1)));
2320 case TRUTH_ORIF_EXPR:
2321 return build (TRUTH_ANDIF_EXPR, type,
2322 invert_truthvalue (TREE_OPERAND (arg, 0)),
2323 invert_truthvalue (TREE_OPERAND (arg, 1)));
2325 case TRUTH_NOT_EXPR:
2326 return TREE_OPERAND (arg, 0);
2329 return build (COND_EXPR, type, TREE_OPERAND (arg, 0),
2330 invert_truthvalue (TREE_OPERAND (arg, 1)),
2331 invert_truthvalue (TREE_OPERAND (arg, 2)));
2334 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
2335 invert_truthvalue (TREE_OPERAND (arg, 1)));
2337 case WITH_RECORD_EXPR:
2338 return build (WITH_RECORD_EXPR, type,
2339 invert_truthvalue (TREE_OPERAND (arg, 0)),
2340 TREE_OPERAND (arg, 1));
2342 case NON_LVALUE_EXPR:
2343 return invert_truthvalue (TREE_OPERAND (arg, 0));
2348 return build1 (TREE_CODE (arg), type,
2349 invert_truthvalue (TREE_OPERAND (arg, 0)));
2352 if (!integer_onep (TREE_OPERAND (arg, 1)))
2354 return build (EQ_EXPR, type, arg, convert (type, integer_zero_node));
2357 return build1 (TRUTH_NOT_EXPR, type, arg);
2359 case CLEANUP_POINT_EXPR:
2360 return build1 (CLEANUP_POINT_EXPR, type,
2361 invert_truthvalue (TREE_OPERAND (arg, 0)));
2366 if (TREE_CODE (TREE_TYPE (arg)) != BOOLEAN_TYPE)
2368 return build1 (TRUTH_NOT_EXPR, type, arg);
2371 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
2372 operands are another bit-wise operation with a common input. If so,
2373 distribute the bit operations to save an operation and possibly two if
2374 constants are involved. For example, convert
2375 (A | B) & (A | C) into A | (B & C)
2376 Further simplification will occur if B and C are constants.
2378 If this optimization cannot be done, 0 will be returned. */
2381 distribute_bit_expr (enum tree_code code, tree type, tree arg0, tree arg1)
2386 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2387 || TREE_CODE (arg0) == code
2388 || (TREE_CODE (arg0) != BIT_AND_EXPR
2389 && TREE_CODE (arg0) != BIT_IOR_EXPR))
2392 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
2394 common = TREE_OPERAND (arg0, 0);
2395 left = TREE_OPERAND (arg0, 1);
2396 right = TREE_OPERAND (arg1, 1);
2398 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
2400 common = TREE_OPERAND (arg0, 0);
2401 left = TREE_OPERAND (arg0, 1);
2402 right = TREE_OPERAND (arg1, 0);
2404 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
2406 common = TREE_OPERAND (arg0, 1);
2407 left = TREE_OPERAND (arg0, 0);
2408 right = TREE_OPERAND (arg1, 1);
2410 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
2412 common = TREE_OPERAND (arg0, 1);
2413 left = TREE_OPERAND (arg0, 0);
2414 right = TREE_OPERAND (arg1, 0);
2419 return fold (build (TREE_CODE (arg0), type, common,
2420 fold (build (code, type, left, right))));
2423 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
2424 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
2427 make_bit_field_ref (tree inner, tree type, int bitsize, int bitpos,
2430 tree result = build (BIT_FIELD_REF, type, inner,
2431 size_int (bitsize), bitsize_int (bitpos));
2433 TREE_UNSIGNED (result) = unsignedp;
2438 /* Optimize a bit-field compare.
2440 There are two cases: First is a compare against a constant and the
2441 second is a comparison of two items where the fields are at the same
2442 bit position relative to the start of a chunk (byte, halfword, word)
2443 large enough to contain it. In these cases we can avoid the shift
2444 implicit in bitfield extractions.
2446 For constants, we emit a compare of the shifted constant with the
2447 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
2448 compared. For two fields at the same position, we do the ANDs with the
2449 similar mask and compare the result of the ANDs.
2451 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
2452 COMPARE_TYPE is the type of the comparison, and LHS and RHS
2453 are the left and right operands of the comparison, respectively.
2455 If the optimization described above can be done, we return the resulting
2456 tree. Otherwise we return zero. */
2459 optimize_bit_field_compare (enum tree_code code, tree compare_type,
2462 HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
2463 tree type = TREE_TYPE (lhs);
2464 tree signed_type, unsigned_type;
2465 int const_p = TREE_CODE (rhs) == INTEGER_CST;
2466 enum machine_mode lmode, rmode, nmode;
2467 int lunsignedp, runsignedp;
2468 int lvolatilep = 0, rvolatilep = 0;
2469 tree linner, rinner = NULL_TREE;
2473 /* Get all the information about the extractions being done. If the bit size
2474 if the same as the size of the underlying object, we aren't doing an
2475 extraction at all and so can do nothing. We also don't want to
2476 do anything if the inner expression is a PLACEHOLDER_EXPR since we
2477 then will no longer be able to replace it. */
2478 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
2479 &lunsignedp, &lvolatilep);
2480 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
2481 || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
2486 /* If this is not a constant, we can only do something if bit positions,
2487 sizes, and signedness are the same. */
2488 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
2489 &runsignedp, &rvolatilep);
2491 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
2492 || lunsignedp != runsignedp || offset != 0
2493 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
2497 /* See if we can find a mode to refer to this field. We should be able to,
2498 but fail if we can't. */
2499 nmode = get_best_mode (lbitsize, lbitpos,
2500 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
2501 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
2502 TYPE_ALIGN (TREE_TYPE (rinner))),
2503 word_mode, lvolatilep || rvolatilep);
2504 if (nmode == VOIDmode)
2507 /* Set signed and unsigned types of the precision of this mode for the
2509 signed_type = (*lang_hooks.types.type_for_mode) (nmode, 0);
2510 unsigned_type = (*lang_hooks.types.type_for_mode) (nmode, 1);
2512 /* Compute the bit position and size for the new reference and our offset
2513 within it. If the new reference is the same size as the original, we
2514 won't optimize anything, so return zero. */
2515 nbitsize = GET_MODE_BITSIZE (nmode);
2516 nbitpos = lbitpos & ~ (nbitsize - 1);
2518 if (nbitsize == lbitsize)
2521 if (BYTES_BIG_ENDIAN)
2522 lbitpos = nbitsize - lbitsize - lbitpos;
2524 /* Make the mask to be used against the extracted field. */
2525 mask = build_int_2 (~0, ~0);
2526 TREE_TYPE (mask) = unsigned_type;
2527 force_fit_type (mask, 0);
2528 mask = convert (unsigned_type, mask);
2529 mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
2530 mask = const_binop (RSHIFT_EXPR, mask,
2531 size_int (nbitsize - lbitsize - lbitpos), 0);
2534 /* If not comparing with constant, just rework the comparison
2536 return build (code, compare_type,
2537 build (BIT_AND_EXPR, unsigned_type,
2538 make_bit_field_ref (linner, unsigned_type,
2539 nbitsize, nbitpos, 1),
2541 build (BIT_AND_EXPR, unsigned_type,
2542 make_bit_field_ref (rinner, unsigned_type,
2543 nbitsize, nbitpos, 1),
2546 /* Otherwise, we are handling the constant case. See if the constant is too
2547 big for the field. Warn and return a tree of for 0 (false) if so. We do
2548 this not only for its own sake, but to avoid having to test for this
2549 error case below. If we didn't, we might generate wrong code.
2551 For unsigned fields, the constant shifted right by the field length should
2552 be all zero. For signed fields, the high-order bits should agree with
2557 if (! integer_zerop (const_binop (RSHIFT_EXPR,
2558 convert (unsigned_type, rhs),
2559 size_int (lbitsize), 0)))
2561 warning ("comparison is always %d due to width of bit-field",
2563 return convert (compare_type,
2565 ? integer_one_node : integer_zero_node));
2570 tree tem = const_binop (RSHIFT_EXPR, convert (signed_type, rhs),
2571 size_int (lbitsize - 1), 0);
2572 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
2574 warning ("comparison is always %d due to width of bit-field",
2576 return convert (compare_type,
2578 ? integer_one_node : integer_zero_node));
2582 /* Single-bit compares should always be against zero. */
2583 if (lbitsize == 1 && ! integer_zerop (rhs))
2585 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
2586 rhs = convert (type, integer_zero_node);
2589 /* Make a new bitfield reference, shift the constant over the
2590 appropriate number of bits and mask it with the computed mask
2591 (in case this was a signed field). If we changed it, make a new one. */
2592 lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1);
2595 TREE_SIDE_EFFECTS (lhs) = 1;
2596 TREE_THIS_VOLATILE (lhs) = 1;
2599 rhs = fold (const_binop (BIT_AND_EXPR,
2600 const_binop (LSHIFT_EXPR,
2601 convert (unsigned_type, rhs),
2602 size_int (lbitpos), 0),
2605 return build (code, compare_type,
2606 build (BIT_AND_EXPR, unsigned_type, lhs, mask),
2610 /* Subroutine for fold_truthop: decode a field reference.
2612 If EXP is a comparison reference, we return the innermost reference.
2614 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
2615 set to the starting bit number.
2617 If the innermost field can be completely contained in a mode-sized
2618 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
2620 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
2621 otherwise it is not changed.
2623 *PUNSIGNEDP is set to the signedness of the field.
2625 *PMASK is set to the mask used. This is either contained in a
2626 BIT_AND_EXPR or derived from the width of the field.
2628 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
2630 Return 0 if this is not a component reference or is one that we can't
2631 do anything with. */
2634 decode_field_reference (tree exp, HOST_WIDE_INT *pbitsize,
2635 HOST_WIDE_INT *pbitpos, enum machine_mode *pmode,
2636 int *punsignedp, int *pvolatilep,
2637 tree *pmask, tree *pand_mask)
2639 tree outer_type = 0;
2641 tree mask, inner, offset;
2643 unsigned int precision;
2645 /* All the optimizations using this function assume integer fields.
2646 There are problems with FP fields since the type_for_size call
2647 below can fail for, e.g., XFmode. */
2648 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
2651 /* We are interested in the bare arrangement of bits, so strip everything
2652 that doesn't affect the machine mode. However, record the type of the
2653 outermost expression if it may matter below. */
2654 if (TREE_CODE (exp) == NOP_EXPR
2655 || TREE_CODE (exp) == CONVERT_EXPR
2656 || TREE_CODE (exp) == NON_LVALUE_EXPR)
2657 outer_type = TREE_TYPE (exp);
2660 if (TREE_CODE (exp) == BIT_AND_EXPR)
2662 and_mask = TREE_OPERAND (exp, 1);
2663 exp = TREE_OPERAND (exp, 0);
2664 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
2665 if (TREE_CODE (and_mask) != INTEGER_CST)
2669 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
2670 punsignedp, pvolatilep);
2671 if ((inner == exp && and_mask == 0)
2672 || *pbitsize < 0 || offset != 0
2673 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
2676 /* If the number of bits in the reference is the same as the bitsize of
2677 the outer type, then the outer type gives the signedness. Otherwise
2678 (in case of a small bitfield) the signedness is unchanged. */
2679 if (outer_type && *pbitsize == tree_low_cst (TYPE_SIZE (outer_type), 1))
2680 *punsignedp = TREE_UNSIGNED (outer_type);
2682 /* Compute the mask to access the bitfield. */
2683 unsigned_type = (*lang_hooks.types.type_for_size) (*pbitsize, 1);
2684 precision = TYPE_PRECISION (unsigned_type);
2686 mask = build_int_2 (~0, ~0);
2687 TREE_TYPE (mask) = unsigned_type;
2688 force_fit_type (mask, 0);
2689 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
2690 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
2692 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
2694 mask = fold (build (BIT_AND_EXPR, unsigned_type,
2695 convert (unsigned_type, and_mask), mask));
2698 *pand_mask = and_mask;
2702 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
2706 all_ones_mask_p (tree mask, int size)
2708 tree type = TREE_TYPE (mask);
2709 unsigned int precision = TYPE_PRECISION (type);
2712 tmask = build_int_2 (~0, ~0);
2713 TREE_TYPE (tmask) = (*lang_hooks.types.signed_type) (type);
2714 force_fit_type (tmask, 0);
2716 tree_int_cst_equal (mask,
2717 const_binop (RSHIFT_EXPR,
2718 const_binop (LSHIFT_EXPR, tmask,
2719 size_int (precision - size),
2721 size_int (precision - size), 0));
2724 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
2725 represents the sign bit of EXP's type. If EXP represents a sign
2726 or zero extension, also test VAL against the unextended type.
2727 The return value is the (sub)expression whose sign bit is VAL,
2728 or NULL_TREE otherwise. */
2731 sign_bit_p (tree exp, tree val)
2733 unsigned HOST_WIDE_INT lo;
2738 /* Tree EXP must have an integral type. */
2739 t = TREE_TYPE (exp);
2740 if (! INTEGRAL_TYPE_P (t))
2743 /* Tree VAL must be an integer constant. */
2744 if (TREE_CODE (val) != INTEGER_CST
2745 || TREE_CONSTANT_OVERFLOW (val))
2748 width = TYPE_PRECISION (t);
2749 if (width > HOST_BITS_PER_WIDE_INT)
2751 hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1);
2757 lo = (unsigned HOST_WIDE_INT) 1 << (width - 1);
2760 if (TREE_INT_CST_HIGH (val) == hi && TREE_INT_CST_LOW (val) == lo)
2763 /* Handle extension from a narrower type. */
2764 if (TREE_CODE (exp) == NOP_EXPR
2765 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width)
2766 return sign_bit_p (TREE_OPERAND (exp, 0), val);
2771 /* Subroutine for fold_truthop: determine if an operand is simple enough
2772 to be evaluated unconditionally. */
2775 simple_operand_p (tree exp)
2777 /* Strip any conversions that don't change the machine mode. */
2778 while ((TREE_CODE (exp) == NOP_EXPR
2779 || TREE_CODE (exp) == CONVERT_EXPR)
2780 && (TYPE_MODE (TREE_TYPE (exp))
2781 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)))))
2782 exp = TREE_OPERAND (exp, 0);
2784 return (TREE_CODE_CLASS (TREE_CODE (exp)) == 'c'
2786 && ! TREE_ADDRESSABLE (exp)
2787 && ! TREE_THIS_VOLATILE (exp)
2788 && ! DECL_NONLOCAL (exp)
2789 /* Don't regard global variables as simple. They may be
2790 allocated in ways unknown to the compiler (shared memory,
2791 #pragma weak, etc). */
2792 && ! TREE_PUBLIC (exp)
2793 && ! DECL_EXTERNAL (exp)
2794 /* Loading a static variable is unduly expensive, but global
2795 registers aren't expensive. */
2796 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
2799 /* The following functions are subroutines to fold_range_test and allow it to
2800 try to change a logical combination of comparisons into a range test.
2803 X == 2 || X == 3 || X == 4 || X == 5
2807 (unsigned) (X - 2) <= 3
2809 We describe each set of comparisons as being either inside or outside
2810 a range, using a variable named like IN_P, and then describe the
2811 range with a lower and upper bound. If one of the bounds is omitted,
2812 it represents either the highest or lowest value of the type.
2814 In the comments below, we represent a range by two numbers in brackets
2815 preceded by a "+" to designate being inside that range, or a "-" to
2816 designate being outside that range, so the condition can be inverted by
2817 flipping the prefix. An omitted bound is represented by a "-". For
2818 example, "- [-, 10]" means being outside the range starting at the lowest
2819 possible value and ending at 10, in other words, being greater than 10.
2820 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
2823 We set up things so that the missing bounds are handled in a consistent
2824 manner so neither a missing bound nor "true" and "false" need to be
2825 handled using a special case. */
2827 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
2828 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
2829 and UPPER1_P are nonzero if the respective argument is an upper bound
2830 and zero for a lower. TYPE, if nonzero, is the type of the result; it
2831 must be specified for a comparison. ARG1 will be converted to ARG0's
2832 type if both are specified. */
2835 range_binop (enum tree_code code, tree type, tree arg0, int upper0_p,
2836 tree arg1, int upper1_p)
2842 /* If neither arg represents infinity, do the normal operation.
2843 Else, if not a comparison, return infinity. Else handle the special
2844 comparison rules. Note that most of the cases below won't occur, but
2845 are handled for consistency. */
2847 if (arg0 != 0 && arg1 != 0)
2849 tem = fold (build (code, type != 0 ? type : TREE_TYPE (arg0),
2850 arg0, convert (TREE_TYPE (arg0), arg1)));
2852 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
2855 if (TREE_CODE_CLASS (code) != '<')
2858 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
2859 for neither. In real maths, we cannot assume open ended ranges are
2860 the same. But, this is computer arithmetic, where numbers are finite.
2861 We can therefore make the transformation of any unbounded range with
2862 the value Z, Z being greater than any representable number. This permits
2863 us to treat unbounded ranges as equal. */
2864 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
2865 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
2869 result = sgn0 == sgn1;
2872 result = sgn0 != sgn1;
2875 result = sgn0 < sgn1;
2878 result = sgn0 <= sgn1;
2881 result = sgn0 > sgn1;
2884 result = sgn0 >= sgn1;
2890 return convert (type, result ? integer_one_node : integer_zero_node);
2893 /* Given EXP, a logical expression, set the range it is testing into
2894 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
2895 actually being tested. *PLOW and *PHIGH will be made of the same type
2896 as the returned expression. If EXP is not a comparison, we will most
2897 likely not be returning a useful value and range. */
2900 make_range (tree exp, int *pin_p, tree *plow, tree *phigh)
2902 enum tree_code code;
2903 tree arg0 = NULL_TREE, arg1 = NULL_TREE, type = NULL_TREE;
2904 tree orig_type = NULL_TREE;
2906 tree low, high, n_low, n_high;
2908 /* Start with simply saying "EXP != 0" and then look at the code of EXP
2909 and see if we can refine the range. Some of the cases below may not
2910 happen, but it doesn't seem worth worrying about this. We "continue"
2911 the outer loop when we've changed something; otherwise we "break"
2912 the switch, which will "break" the while. */
2914 in_p = 0, low = high = convert (TREE_TYPE (exp), integer_zero_node);
2918 code = TREE_CODE (exp);
2920 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
2922 if (first_rtl_op (code) > 0)
2923 arg0 = TREE_OPERAND (exp, 0);
2924 if (TREE_CODE_CLASS (code) == '<'
2925 || TREE_CODE_CLASS (code) == '1'
2926 || TREE_CODE_CLASS (code) == '2')
2927 type = TREE_TYPE (arg0);
2928 if (TREE_CODE_CLASS (code) == '2'
2929 || TREE_CODE_CLASS (code) == '<'
2930 || (TREE_CODE_CLASS (code) == 'e'
2931 && TREE_CODE_LENGTH (code) > 1))
2932 arg1 = TREE_OPERAND (exp, 1);
2935 /* Set ORIG_TYPE as soon as TYPE is non-null so that we do not
2936 lose a cast by accident. */
2937 if (type != NULL_TREE && orig_type == NULL_TREE)
2942 case TRUTH_NOT_EXPR:
2943 in_p = ! in_p, exp = arg0;
2946 case EQ_EXPR: case NE_EXPR:
2947 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
2948 /* We can only do something if the range is testing for zero
2949 and if the second operand is an integer constant. Note that
2950 saying something is "in" the range we make is done by
2951 complementing IN_P since it will set in the initial case of
2952 being not equal to zero; "out" is leaving it alone. */
2953 if (low == 0 || high == 0
2954 || ! integer_zerop (low) || ! integer_zerop (high)
2955 || TREE_CODE (arg1) != INTEGER_CST)
2960 case NE_EXPR: /* - [c, c] */
2963 case EQ_EXPR: /* + [c, c] */
2964 in_p = ! in_p, low = high = arg1;
2966 case GT_EXPR: /* - [-, c] */
2967 low = 0, high = arg1;
2969 case GE_EXPR: /* + [c, -] */
2970 in_p = ! in_p, low = arg1, high = 0;
2972 case LT_EXPR: /* - [c, -] */
2973 low = arg1, high = 0;
2975 case LE_EXPR: /* + [-, c] */
2976 in_p = ! in_p, low = 0, high = arg1;
2984 /* If this is an unsigned comparison, we also know that EXP is
2985 greater than or equal to zero. We base the range tests we make
2986 on that fact, so we record it here so we can parse existing
2988 if (TREE_UNSIGNED (type) && (low == 0 || high == 0))
2990 if (! merge_ranges (&n_in_p, &n_low, &n_high, in_p, low, high,
2991 1, convert (type, integer_zero_node),
2995 in_p = n_in_p, low = n_low, high = n_high;
2997 /* If the high bound is missing, but we
2998 have a low bound, reverse the range so
2999 it goes from zero to the low bound minus 1. */
3000 if (high == 0 && low)
3003 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
3004 integer_one_node, 0);
3005 low = convert (type, integer_zero_node);
3011 /* (-x) IN [a,b] -> x in [-b, -a] */
3012 n_low = range_binop (MINUS_EXPR, type,
3013 convert (type, integer_zero_node), 0, high, 1);
3014 n_high = range_binop (MINUS_EXPR, type,
3015 convert (type, integer_zero_node), 0, low, 0);
3016 low = n_low, high = n_high;
3022 exp = build (MINUS_EXPR, type, negate_expr (arg0),
3023 convert (type, integer_one_node));
3026 case PLUS_EXPR: case MINUS_EXPR:
3027 if (TREE_CODE (arg1) != INTEGER_CST)
3030 /* If EXP is signed, any overflow in the computation is undefined,
3031 so we don't worry about it so long as our computations on
3032 the bounds don't overflow. For unsigned, overflow is defined
3033 and this is exactly the right thing. */
3034 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3035 type, low, 0, arg1, 0);
3036 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3037 type, high, 1, arg1, 0);
3038 if ((n_low != 0 && TREE_OVERFLOW (n_low))
3039 || (n_high != 0 && TREE_OVERFLOW (n_high)))
3042 /* Check for an unsigned range which has wrapped around the maximum
3043 value thus making n_high < n_low, and normalize it. */
3044 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
3046 low = range_binop (PLUS_EXPR, type, n_high, 0,
3047 integer_one_node, 0);
3048 high = range_binop (MINUS_EXPR, type, n_low, 0,
3049 integer_one_node, 0);
3051 /* If the range is of the form +/- [ x+1, x ], we won't
3052 be able to normalize it. But then, it represents the
3053 whole range or the empty set, so make it
3055 if (tree_int_cst_equal (n_low, low)
3056 && tree_int_cst_equal (n_high, high))
3062 low = n_low, high = n_high;
3067 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
3068 if (TYPE_PRECISION (type) > TYPE_PRECISION (orig_type))
3071 if (! INTEGRAL_TYPE_P (type)
3072 || (low != 0 && ! int_fits_type_p (low, type))
3073 || (high != 0 && ! int_fits_type_p (high, type)))
3076 n_low = low, n_high = high;
3079 n_low = convert (type, n_low);
3082 n_high = convert (type, n_high);
3084 /* If we're converting from an unsigned to a signed type,
3085 we will be doing the comparison as unsigned. The tests above
3086 have already verified that LOW and HIGH are both positive.
3088 So we have to make sure that the original unsigned value will
3089 be interpreted as positive. */
3090 if (TREE_UNSIGNED (type) && ! TREE_UNSIGNED (TREE_TYPE (exp)))
3092 tree equiv_type = (*lang_hooks.types.type_for_mode)
3093 (TYPE_MODE (type), 1);
3096 /* A range without an upper bound is, naturally, unbounded.
3097 Since convert would have cropped a very large value, use
3098 the max value for the destination type. */
3100 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
3101 : TYPE_MAX_VALUE (type);
3103 if (TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (exp)))
3104 high_positive = fold (build (RSHIFT_EXPR, type,
3105 convert (type, high_positive),
3106 convert (type, integer_one_node)));
3108 /* If the low bound is specified, "and" the range with the
3109 range for which the original unsigned value will be
3113 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3115 1, convert (type, integer_zero_node),
3119 in_p = (n_in_p == in_p);
3123 /* Otherwise, "or" the range with the range of the input
3124 that will be interpreted as negative. */
3125 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3127 1, convert (type, integer_zero_node),
3131 in_p = (in_p != n_in_p);
3136 low = n_low, high = n_high;
3146 /* If EXP is a constant, we can evaluate whether this is true or false. */
3147 if (TREE_CODE (exp) == INTEGER_CST)
3149 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
3151 && integer_onep (range_binop (LE_EXPR, integer_type_node,
3157 *pin_p = in_p, *plow = low, *phigh = high;
3161 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3162 type, TYPE, return an expression to test if EXP is in (or out of, depending
3163 on IN_P) the range. */
3166 build_range_check (tree type, tree exp, int in_p, tree low, tree high)
3168 tree etype = TREE_TYPE (exp);
3172 && (0 != (value = build_range_check (type, exp, 1, low, high))))
3173 return invert_truthvalue (value);
3175 if (low == 0 && high == 0)
3176 return convert (type, integer_one_node);
3179 return fold (build (LE_EXPR, type, exp, high));
3182 return fold (build (GE_EXPR, type, exp, low));
3184 if (operand_equal_p (low, high, 0))
3185 return fold (build (EQ_EXPR, type, exp, low));
3187 if (integer_zerop (low))
3189 if (! TREE_UNSIGNED (etype))
3191 etype = (*lang_hooks.types.unsigned_type) (etype);
3192 high = convert (etype, high);
3193 exp = convert (etype, exp);
3195 return build_range_check (type, exp, 1, 0, high);
3198 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
3199 if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST)
3201 unsigned HOST_WIDE_INT lo;
3205 prec = TYPE_PRECISION (etype);
3206 if (prec <= HOST_BITS_PER_WIDE_INT)
3209 lo = ((unsigned HOST_WIDE_INT) 1 << (prec - 1)) - 1;
3213 hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1;
3214 lo = (unsigned HOST_WIDE_INT) -1;
3217 if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo)
3219 if (TREE_UNSIGNED (etype))
3221 etype = (*lang_hooks.types.signed_type) (etype);
3222 exp = convert (etype, exp);
3224 return fold (build (GT_EXPR, type, exp,
3225 convert (etype, integer_zero_node)));
3229 if (0 != (value = const_binop (MINUS_EXPR, high, low, 0))
3230 && ! TREE_OVERFLOW (value))
3231 return build_range_check (type,
3232 fold (build (MINUS_EXPR, etype, exp, low)),
3233 1, convert (etype, integer_zero_node), value);
3238 /* Given two ranges, see if we can merge them into one. Return 1 if we
3239 can, 0 if we can't. Set the output range into the specified parameters. */
3242 merge_ranges (int *pin_p, tree *plow, tree *phigh, int in0_p, tree low0,
3243 tree high0, int in1_p, tree low1, tree high1)
3251 int lowequal = ((low0 == 0 && low1 == 0)
3252 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3253 low0, 0, low1, 0)));
3254 int highequal = ((high0 == 0 && high1 == 0)
3255 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3256 high0, 1, high1, 1)));
3258 /* Make range 0 be the range that starts first, or ends last if they
3259 start at the same value. Swap them if it isn't. */
3260 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
3263 && integer_onep (range_binop (GT_EXPR, integer_type_node,
3264 high1, 1, high0, 1))))
3266 temp = in0_p, in0_p = in1_p, in1_p = temp;
3267 tem = low0, low0 = low1, low1 = tem;
3268 tem = high0, high0 = high1, high1 = tem;
3271 /* Now flag two cases, whether the ranges are disjoint or whether the
3272 second range is totally subsumed in the first. Note that the tests
3273 below are simplified by the ones above. */
3274 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
3275 high0, 1, low1, 0));
3276 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
3277 high1, 1, high0, 1));
3279 /* We now have four cases, depending on whether we are including or
3280 excluding the two ranges. */
3283 /* If they don't overlap, the result is false. If the second range
3284 is a subset it is the result. Otherwise, the range is from the start
3285 of the second to the end of the first. */
3287 in_p = 0, low = high = 0;
3289 in_p = 1, low = low1, high = high1;
3291 in_p = 1, low = low1, high = high0;
3294 else if (in0_p && ! in1_p)
3296 /* If they don't overlap, the result is the first range. If they are
3297 equal, the result is false. If the second range is a subset of the
3298 first, and the ranges begin at the same place, we go from just after
3299 the end of the first range to the end of the second. If the second
3300 range is not a subset of the first, or if it is a subset and both
3301 ranges end at the same place, the range starts at the start of the
3302 first range and ends just before the second range.
3303 Otherwise, we can't describe this as a single range. */
3305 in_p = 1, low = low0, high = high0;
3306 else if (lowequal && highequal)
3307 in_p = 0, low = high = 0;
3308 else if (subset && lowequal)
3310 in_p = 1, high = high0;
3311 low = range_binop (PLUS_EXPR, NULL_TREE, high1, 0,
3312 integer_one_node, 0);
3314 else if (! subset || highequal)
3316 in_p = 1, low = low0;
3317 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
3318 integer_one_node, 0);
3324 else if (! in0_p && in1_p)
3326 /* If they don't overlap, the result is the second range. If the second
3327 is a subset of the first, the result is false. Otherwise,
3328 the range starts just after the first range and ends at the
3329 end of the second. */
3331 in_p = 1, low = low1, high = high1;
3332 else if (subset || highequal)
3333 in_p = 0, low = high = 0;
3336 in_p = 1, high = high1;
3337 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
3338 integer_one_node, 0);
3344 /* The case where we are excluding both ranges. Here the complex case
3345 is if they don't overlap. In that case, the only time we have a
3346 range is if they are adjacent. If the second is a subset of the
3347 first, the result is the first. Otherwise, the range to exclude
3348 starts at the beginning of the first range and ends at the end of the
3352 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
3353 range_binop (PLUS_EXPR, NULL_TREE,
3355 integer_one_node, 1),
3357 in_p = 0, low = low0, high = high1;
3362 in_p = 0, low = low0, high = high0;
3364 in_p = 0, low = low0, high = high1;
3367 *pin_p = in_p, *plow = low, *phigh = high;
3371 #ifndef RANGE_TEST_NON_SHORT_CIRCUIT
3372 #define RANGE_TEST_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
3375 /* EXP is some logical combination of boolean tests. See if we can
3376 merge it into some range test. Return the new tree if so. */
3379 fold_range_test (tree exp)
3381 int or_op = (TREE_CODE (exp) == TRUTH_ORIF_EXPR
3382 || TREE_CODE (exp) == TRUTH_OR_EXPR);
3383 int in0_p, in1_p, in_p;
3384 tree low0, low1, low, high0, high1, high;
3385 tree lhs = make_range (TREE_OPERAND (exp, 0), &in0_p, &low0, &high0);
3386 tree rhs = make_range (TREE_OPERAND (exp, 1), &in1_p, &low1, &high1);
3389 /* If this is an OR operation, invert both sides; we will invert
3390 again at the end. */
3392 in0_p = ! in0_p, in1_p = ! in1_p;
3394 /* If both expressions are the same, if we can merge the ranges, and we
3395 can build the range test, return it or it inverted. If one of the
3396 ranges is always true or always false, consider it to be the same
3397 expression as the other. */
3398 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
3399 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
3401 && 0 != (tem = (build_range_check (TREE_TYPE (exp),
3403 : rhs != 0 ? rhs : integer_zero_node,
3405 return or_op ? invert_truthvalue (tem) : tem;
3407 /* On machines where the branch cost is expensive, if this is a
3408 short-circuited branch and the underlying object on both sides
3409 is the same, make a non-short-circuit operation. */
3410 else if (RANGE_TEST_NON_SHORT_CIRCUIT
3411 && lhs != 0 && rhs != 0
3412 && (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3413 || TREE_CODE (exp) == TRUTH_ORIF_EXPR)
3414 && operand_equal_p (lhs, rhs, 0))
3416 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
3417 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
3418 which cases we can't do this. */
3419 if (simple_operand_p (lhs))
3420 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3421 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3422 TREE_TYPE (exp), TREE_OPERAND (exp, 0),
3423 TREE_OPERAND (exp, 1));
3425 else if ((*lang_hooks.decls.global_bindings_p) () == 0
3426 && ! CONTAINS_PLACEHOLDER_P (lhs))
3428 tree common = save_expr (lhs);
3430 if (0 != (lhs = build_range_check (TREE_TYPE (exp), common,
3431 or_op ? ! in0_p : in0_p,
3433 && (0 != (rhs = build_range_check (TREE_TYPE (exp), common,
3434 or_op ? ! in1_p : in1_p,
3436 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3437 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3438 TREE_TYPE (exp), lhs, rhs);
3445 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
3446 bit value. Arrange things so the extra bits will be set to zero if and
3447 only if C is signed-extended to its full width. If MASK is nonzero,
3448 it is an INTEGER_CST that should be AND'ed with the extra bits. */
3451 unextend (tree c, int p, int unsignedp, tree mask)
3453 tree type = TREE_TYPE (c);
3454 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
3457 if (p == modesize || unsignedp)
3460 /* We work by getting just the sign bit into the low-order bit, then
3461 into the high-order bit, then sign-extend. We then XOR that value
3463 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
3464 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
3466 /* We must use a signed type in order to get an arithmetic right shift.
3467 However, we must also avoid introducing accidental overflows, so that
3468 a subsequent call to integer_zerop will work. Hence we must
3469 do the type conversion here. At this point, the constant is either
3470 zero or one, and the conversion to a signed type can never overflow.
3471 We could get an overflow if this conversion is done anywhere else. */
3472 if (TREE_UNSIGNED (type))
3473 temp = convert ((*lang_hooks.types.signed_type) (type), temp);
3475 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
3476 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
3478 temp = const_binop (BIT_AND_EXPR, temp, convert (TREE_TYPE (c), mask), 0);
3479 /* If necessary, convert the type back to match the type of C. */
3480 if (TREE_UNSIGNED (type))
3481 temp = convert (type, temp);
3483 return convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
3486 /* Find ways of folding logical expressions of LHS and RHS:
3487 Try to merge two comparisons to the same innermost item.
3488 Look for range tests like "ch >= '0' && ch <= '9'".
3489 Look for combinations of simple terms on machines with expensive branches
3490 and evaluate the RHS unconditionally.
3492 For example, if we have p->a == 2 && p->b == 4 and we can make an
3493 object large enough to span both A and B, we can do this with a comparison
3494 against the object ANDed with the a mask.
3496 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
3497 operations to do this with one comparison.
3499 We check for both normal comparisons and the BIT_AND_EXPRs made this by
3500 function and the one above.
3502 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
3503 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
3505 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
3508 We return the simplified tree or 0 if no optimization is possible. */
3511 fold_truthop (enum tree_code code, tree truth_type, tree lhs, tree rhs)
3513 /* If this is the "or" of two comparisons, we can do something if
3514 the comparisons are NE_EXPR. If this is the "and", we can do something
3515 if the comparisons are EQ_EXPR. I.e.,
3516 (a->b == 2 && a->c == 4) can become (a->new == NEW).
3518 WANTED_CODE is this operation code. For single bit fields, we can
3519 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
3520 comparison for one-bit fields. */
3522 enum tree_code wanted_code;
3523 enum tree_code lcode, rcode;
3524 tree ll_arg, lr_arg, rl_arg, rr_arg;
3525 tree ll_inner, lr_inner, rl_inner, rr_inner;
3526 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
3527 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
3528 HOST_WIDE_INT xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
3529 HOST_WIDE_INT lnbitsize, lnbitpos, rnbitsize, rnbitpos;
3530 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
3531 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
3532 enum machine_mode lnmode, rnmode;
3533 tree ll_mask, lr_mask, rl_mask, rr_mask;
3534 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
3535 tree l_const, r_const;
3536 tree lntype, rntype, result;
3537 int first_bit, end_bit;
3540 /* Start by getting the comparison codes. Fail if anything is volatile.
3541 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
3542 it were surrounded with a NE_EXPR. */
3544 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
3547 lcode = TREE_CODE (lhs);
3548 rcode = TREE_CODE (rhs);
3550 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
3551 lcode = NE_EXPR, lhs = build (NE_EXPR, truth_type, lhs, integer_zero_node);
3553 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
3554 rcode = NE_EXPR, rhs = build (NE_EXPR, truth_type, rhs, integer_zero_node);
3556 if (TREE_CODE_CLASS (lcode) != '<' || TREE_CODE_CLASS (rcode) != '<')
3559 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
3560 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
3562 ll_arg = TREE_OPERAND (lhs, 0);
3563 lr_arg = TREE_OPERAND (lhs, 1);
3564 rl_arg = TREE_OPERAND (rhs, 0);
3565 rr_arg = TREE_OPERAND (rhs, 1);
3567 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
3568 if (simple_operand_p (ll_arg)
3569 && simple_operand_p (lr_arg)
3570 && !FLOAT_TYPE_P (TREE_TYPE (ll_arg)))
3574 if (operand_equal_p (ll_arg, rl_arg, 0)
3575 && operand_equal_p (lr_arg, rr_arg, 0))
3577 int lcompcode, rcompcode;
3579 lcompcode = comparison_to_compcode (lcode);
3580 rcompcode = comparison_to_compcode (rcode);
3581 compcode = (code == TRUTH_AND_EXPR)
3582 ? lcompcode & rcompcode
3583 : lcompcode | rcompcode;
3585 else if (operand_equal_p (ll_arg, rr_arg, 0)
3586 && operand_equal_p (lr_arg, rl_arg, 0))
3588 int lcompcode, rcompcode;
3590 rcode = swap_tree_comparison (rcode);
3591 lcompcode = comparison_to_compcode (lcode);
3592 rcompcode = comparison_to_compcode (rcode);
3593 compcode = (code == TRUTH_AND_EXPR)
3594 ? lcompcode & rcompcode
3595 : lcompcode | rcompcode;
3600 if (compcode == COMPCODE_TRUE)
3601 return convert (truth_type, integer_one_node);
3602 else if (compcode == COMPCODE_FALSE)
3603 return convert (truth_type, integer_zero_node);
3604 else if (compcode != -1)
3605 return build (compcode_to_comparison (compcode),
3606 truth_type, ll_arg, lr_arg);
3609 /* If the RHS can be evaluated unconditionally and its operands are
3610 simple, it wins to evaluate the RHS unconditionally on machines
3611 with expensive branches. In this case, this isn't a comparison
3612 that can be merged. Avoid doing this if the RHS is a floating-point
3613 comparison since those can trap. */
3615 if (BRANCH_COST >= 2
3616 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
3617 && simple_operand_p (rl_arg)
3618 && simple_operand_p (rr_arg))
3620 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
3621 if (code == TRUTH_OR_EXPR
3622 && lcode == NE_EXPR && integer_zerop (lr_arg)
3623 && rcode == NE_EXPR && integer_zerop (rr_arg)
3624 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
3625 return build (NE_EXPR, truth_type,
3626 build (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
3630 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
3631 if (code == TRUTH_AND_EXPR
3632 && lcode == EQ_EXPR && integer_zerop (lr_arg)
3633 && rcode == EQ_EXPR && integer_zerop (rr_arg)
3634 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
3635 return build (EQ_EXPR, truth_type,
3636 build (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
3640 return build (code, truth_type, lhs, rhs);
3643 /* See if the comparisons can be merged. Then get all the parameters for
3646 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
3647 || (rcode != EQ_EXPR && rcode != NE_EXPR))
3651 ll_inner = decode_field_reference (ll_arg,
3652 &ll_bitsize, &ll_bitpos, &ll_mode,
3653 &ll_unsignedp, &volatilep, &ll_mask,
3655 lr_inner = decode_field_reference (lr_arg,
3656 &lr_bitsize, &lr_bitpos, &lr_mode,
3657 &lr_unsignedp, &volatilep, &lr_mask,
3659 rl_inner = decode_field_reference (rl_arg,
3660 &rl_bitsize, &rl_bitpos, &rl_mode,
3661 &rl_unsignedp, &volatilep, &rl_mask,
3663 rr_inner = decode_field_reference (rr_arg,
3664 &rr_bitsize, &rr_bitpos, &rr_mode,
3665 &rr_unsignedp, &volatilep, &rr_mask,
3668 /* It must be true that the inner operation on the lhs of each
3669 comparison must be the same if we are to be able to do anything.
3670 Then see if we have constants. If not, the same must be true for
3672 if (volatilep || ll_inner == 0 || rl_inner == 0
3673 || ! operand_equal_p (ll_inner, rl_inner, 0))
3676 if (TREE_CODE (lr_arg) == INTEGER_CST
3677 && TREE_CODE (rr_arg) == INTEGER_CST)
3678 l_const = lr_arg, r_const = rr_arg;
3679 else if (lr_inner == 0 || rr_inner == 0
3680 || ! operand_equal_p (lr_inner, rr_inner, 0))
3683 l_const = r_const = 0;
3685 /* If either comparison code is not correct for our logical operation,
3686 fail. However, we can convert a one-bit comparison against zero into
3687 the opposite comparison against that bit being set in the field. */
3689 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
3690 if (lcode != wanted_code)
3692 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
3694 /* Make the left operand unsigned, since we are only interested
3695 in the value of one bit. Otherwise we are doing the wrong
3704 /* This is analogous to the code for l_const above. */
3705 if (rcode != wanted_code)
3707 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
3716 /* After this point all optimizations will generate bit-field
3717 references, which we might not want. */
3718 if (! (*lang_hooks.can_use_bit_fields_p) ())
3721 /* See if we can find a mode that contains both fields being compared on
3722 the left. If we can't, fail. Otherwise, update all constants and masks
3723 to be relative to a field of that size. */
3724 first_bit = MIN (ll_bitpos, rl_bitpos);
3725 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
3726 lnmode = get_best_mode (end_bit - first_bit, first_bit,
3727 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
3729 if (lnmode == VOIDmode)
3732 lnbitsize = GET_MODE_BITSIZE (lnmode);
3733 lnbitpos = first_bit & ~ (lnbitsize - 1);
3734 lntype = (*lang_hooks.types.type_for_size) (lnbitsize, 1);
3735 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
3737 if (BYTES_BIG_ENDIAN)
3739 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
3740 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
3743 ll_mask = const_binop (LSHIFT_EXPR, convert (lntype, ll_mask),
3744 size_int (xll_bitpos), 0);
3745 rl_mask = const_binop (LSHIFT_EXPR, convert (lntype, rl_mask),
3746 size_int (xrl_bitpos), 0);
3750 l_const = convert (lntype, l_const);
3751 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
3752 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
3753 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
3754 fold (build1 (BIT_NOT_EXPR,
3758 warning ("comparison is always %d", wanted_code == NE_EXPR);
3760 return convert (truth_type,
3761 wanted_code == NE_EXPR
3762 ? integer_one_node : integer_zero_node);
3767 r_const = convert (lntype, r_const);
3768 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
3769 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
3770 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
3771 fold (build1 (BIT_NOT_EXPR,
3775 warning ("comparison is always %d", wanted_code == NE_EXPR);
3777 return convert (truth_type,
3778 wanted_code == NE_EXPR
3779 ? integer_one_node : integer_zero_node);
3783 /* If the right sides are not constant, do the same for it. Also,
3784 disallow this optimization if a size or signedness mismatch occurs
3785 between the left and right sides. */
3788 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
3789 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
3790 /* Make sure the two fields on the right
3791 correspond to the left without being swapped. */
3792 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
3795 first_bit = MIN (lr_bitpos, rr_bitpos);
3796 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
3797 rnmode = get_best_mode (end_bit - first_bit, first_bit,
3798 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
3800 if (rnmode == VOIDmode)
3803 rnbitsize = GET_MODE_BITSIZE (rnmode);
3804 rnbitpos = first_bit & ~ (rnbitsize - 1);
3805 rntype = (*lang_hooks.types.type_for_size) (rnbitsize, 1);
3806 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
3808 if (BYTES_BIG_ENDIAN)
3810 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
3811 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
3814 lr_mask = const_binop (LSHIFT_EXPR, convert (rntype, lr_mask),
3815 size_int (xlr_bitpos), 0);
3816 rr_mask = const_binop (LSHIFT_EXPR, convert (rntype, rr_mask),
3817 size_int (xrr_bitpos), 0);
3819 /* Make a mask that corresponds to both fields being compared.
3820 Do this for both items being compared. If the operands are the
3821 same size and the bits being compared are in the same position
3822 then we can do this by masking both and comparing the masked
3824 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
3825 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
3826 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
3828 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
3829 ll_unsignedp || rl_unsignedp);
3830 if (! all_ones_mask_p (ll_mask, lnbitsize))
3831 lhs = build (BIT_AND_EXPR, lntype, lhs, ll_mask);
3833 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
3834 lr_unsignedp || rr_unsignedp);
3835 if (! all_ones_mask_p (lr_mask, rnbitsize))
3836 rhs = build (BIT_AND_EXPR, rntype, rhs, lr_mask);
3838 return build (wanted_code, truth_type, lhs, rhs);
3841 /* There is still another way we can do something: If both pairs of
3842 fields being compared are adjacent, we may be able to make a wider
3843 field containing them both.
3845 Note that we still must mask the lhs/rhs expressions. Furthermore,
3846 the mask must be shifted to account for the shift done by
3847 make_bit_field_ref. */
3848 if ((ll_bitsize + ll_bitpos == rl_bitpos
3849 && lr_bitsize + lr_bitpos == rr_bitpos)
3850 || (ll_bitpos == rl_bitpos + rl_bitsize
3851 && lr_bitpos == rr_bitpos + rr_bitsize))
3855 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
3856 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
3857 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
3858 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
3860 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
3861 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
3862 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
3863 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
3865 /* Convert to the smaller type before masking out unwanted bits. */
3867 if (lntype != rntype)
3869 if (lnbitsize > rnbitsize)
3871 lhs = convert (rntype, lhs);
3872 ll_mask = convert (rntype, ll_mask);
3875 else if (lnbitsize < rnbitsize)
3877 rhs = convert (lntype, rhs);
3878 lr_mask = convert (lntype, lr_mask);
3883 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
3884 lhs = build (BIT_AND_EXPR, type, lhs, ll_mask);
3886 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
3887 rhs = build (BIT_AND_EXPR, type, rhs, lr_mask);
3889 return build (wanted_code, truth_type, lhs, rhs);
3895 /* Handle the case of comparisons with constants. If there is something in
3896 common between the masks, those bits of the constants must be the same.
3897 If not, the condition is always false. Test for this to avoid generating
3898 incorrect code below. */
3899 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
3900 if (! integer_zerop (result)
3901 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
3902 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
3904 if (wanted_code == NE_EXPR)
3906 warning ("`or' of unmatched not-equal tests is always 1");
3907 return convert (truth_type, integer_one_node);
3911 warning ("`and' of mutually exclusive equal-tests is always 0");
3912 return convert (truth_type, integer_zero_node);
3916 /* Construct the expression we will return. First get the component
3917 reference we will make. Unless the mask is all ones the width of
3918 that field, perform the mask operation. Then compare with the
3920 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
3921 ll_unsignedp || rl_unsignedp);
3923 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
3924 if (! all_ones_mask_p (ll_mask, lnbitsize))
3925 result = build (BIT_AND_EXPR, lntype, result, ll_mask);
3927 return build (wanted_code, truth_type, result,
3928 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
3931 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
3935 optimize_minmax_comparison (tree t)
3937 tree type = TREE_TYPE (t);
3938 tree arg0 = TREE_OPERAND (t, 0);
3939 enum tree_code op_code;
3940 tree comp_const = TREE_OPERAND (t, 1);
3942 int consts_equal, consts_lt;
3945 STRIP_SIGN_NOPS (arg0);
3947 op_code = TREE_CODE (arg0);
3948 minmax_const = TREE_OPERAND (arg0, 1);
3949 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
3950 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
3951 inner = TREE_OPERAND (arg0, 0);
3953 /* If something does not permit us to optimize, return the original tree. */
3954 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
3955 || TREE_CODE (comp_const) != INTEGER_CST
3956 || TREE_CONSTANT_OVERFLOW (comp_const)
3957 || TREE_CODE (minmax_const) != INTEGER_CST
3958 || TREE_CONSTANT_OVERFLOW (minmax_const))
3961 /* Now handle all the various comparison codes. We only handle EQ_EXPR
3962 and GT_EXPR, doing the rest with recursive calls using logical
3964 switch (TREE_CODE (t))
3966 case NE_EXPR: case LT_EXPR: case LE_EXPR:
3968 invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t)));
3972 fold (build (TRUTH_ORIF_EXPR, type,
3973 optimize_minmax_comparison
3974 (build (EQ_EXPR, type, arg0, comp_const)),
3975 optimize_minmax_comparison
3976 (build (GT_EXPR, type, arg0, comp_const))));
3979 if (op_code == MAX_EXPR && consts_equal)
3980 /* MAX (X, 0) == 0 -> X <= 0 */
3981 return fold (build (LE_EXPR, type, inner, comp_const));
3983 else if (op_code == MAX_EXPR && consts_lt)
3984 /* MAX (X, 0) == 5 -> X == 5 */
3985 return fold (build (EQ_EXPR, type, inner, comp_const));
3987 else if (op_code == MAX_EXPR)
3988 /* MAX (X, 0) == -1 -> false */
3989 return omit_one_operand (type, integer_zero_node, inner);
3991 else if (consts_equal)
3992 /* MIN (X, 0) == 0 -> X >= 0 */
3993 return fold (build (GE_EXPR, type, inner, comp_const));
3996 /* MIN (X, 0) == 5 -> false */
3997 return omit_one_operand (type, integer_zero_node, inner);
4000 /* MIN (X, 0) == -1 -> X == -1 */
4001 return fold (build (EQ_EXPR, type, inner, comp_const));
4004 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
4005 /* MAX (X, 0) > 0 -> X > 0
4006 MAX (X, 0) > 5 -> X > 5 */
4007 return fold (build (GT_EXPR, type, inner, comp_const));
4009 else if (op_code == MAX_EXPR)
4010 /* MAX (X, 0) > -1 -> true */
4011 return omit_one_operand (type, integer_one_node, inner);
4013 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
4014 /* MIN (X, 0) > 0 -> false
4015 MIN (X, 0) > 5 -> false */
4016 return omit_one_operand (type, integer_zero_node, inner);
4019 /* MIN (X, 0) > -1 -> X > -1 */
4020 return fold (build (GT_EXPR, type, inner, comp_const));
4027 /* T is an integer expression that is being multiplied, divided, or taken a
4028 modulus (CODE says which and what kind of divide or modulus) by a
4029 constant C. See if we can eliminate that operation by folding it with
4030 other operations already in T. WIDE_TYPE, if non-null, is a type that
4031 should be used for the computation if wider than our type.
4033 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
4034 (X * 2) + (Y * 4). We must, however, be assured that either the original
4035 expression would not overflow or that overflow is undefined for the type
4036 in the language in question.
4038 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
4039 the machine has a multiply-accumulate insn or that this is part of an
4040 addressing calculation.
4042 If we return a non-null expression, it is an equivalent form of the
4043 original computation, but need not be in the original type. */
4046 extract_muldiv (tree t, tree c, enum tree_code code, tree wide_type)
4048 /* To avoid exponential search depth, refuse to allow recursion past
4049 three levels. Beyond that (1) it's highly unlikely that we'll find
4050 something interesting and (2) we've probably processed it before
4051 when we built the inner expression. */
4060 ret = extract_muldiv_1 (t, c, code, wide_type);
4067 extract_muldiv_1 (tree t, tree c, enum tree_code code, tree wide_type)
4069 tree type = TREE_TYPE (t);
4070 enum tree_code tcode = TREE_CODE (t);
4071 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
4072 > GET_MODE_SIZE (TYPE_MODE (type)))
4073 ? wide_type : type);
4075 int same_p = tcode == code;
4076 tree op0 = NULL_TREE, op1 = NULL_TREE;
4078 /* Don't deal with constants of zero here; they confuse the code below. */
4079 if (integer_zerop (c))
4082 if (TREE_CODE_CLASS (tcode) == '1')
4083 op0 = TREE_OPERAND (t, 0);
4085 if (TREE_CODE_CLASS (tcode) == '2')
4086 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
4088 /* Note that we need not handle conditional operations here since fold
4089 already handles those cases. So just do arithmetic here. */
4093 /* For a constant, we can always simplify if we are a multiply
4094 or (for divide and modulus) if it is a multiple of our constant. */
4095 if (code == MULT_EXPR
4096 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
4097 return const_binop (code, convert (ctype, t), convert (ctype, c), 0);
4100 case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
4101 /* If op0 is an expression ... */
4102 if ((TREE_CODE_CLASS (TREE_CODE (op0)) == '<'
4103 || TREE_CODE_CLASS (TREE_CODE (op0)) == '1'
4104 || TREE_CODE_CLASS (TREE_CODE (op0)) == '2'
4105 || TREE_CODE_CLASS (TREE_CODE (op0)) == 'e')
4106 /* ... and is unsigned, and its type is smaller than ctype,
4107 then we cannot pass through as widening. */
4108 && ((TREE_UNSIGNED (TREE_TYPE (op0))
4109 && ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
4110 && TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
4111 && (GET_MODE_SIZE (TYPE_MODE (ctype))
4112 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
4113 /* ... or its type is larger than ctype,
4114 then we cannot pass through this truncation. */
4115 || (GET_MODE_SIZE (TYPE_MODE (ctype))
4116 < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0))))
4117 /* ... or signedness changes for division or modulus,
4118 then we cannot pass through this conversion. */
4119 || (code != MULT_EXPR
4120 && (TREE_UNSIGNED (ctype)
4121 != TREE_UNSIGNED (TREE_TYPE (op0))))))
4124 /* Pass the constant down and see if we can make a simplification. If
4125 we can, replace this expression with the inner simplification for
4126 possible later conversion to our or some other type. */
4127 if ((t2 = convert (TREE_TYPE (op0), c)) != 0
4128 && TREE_CODE (t2) == INTEGER_CST
4129 && ! TREE_CONSTANT_OVERFLOW (t2)
4130 && (0 != (t1 = extract_muldiv (op0, t2, code,
4132 ? ctype : NULL_TREE))))
4136 case NEGATE_EXPR: case ABS_EXPR:
4137 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4138 return fold (build1 (tcode, ctype, convert (ctype, t1)));
4141 case MIN_EXPR: case MAX_EXPR:
4142 /* If widening the type changes the signedness, then we can't perform
4143 this optimization as that changes the result. */
4144 if (TREE_UNSIGNED (ctype) != TREE_UNSIGNED (type))
4147 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
4148 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0
4149 && (t2 = extract_muldiv (op1, c, code, wide_type)) != 0)
4151 if (tree_int_cst_sgn (c) < 0)
4152 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
4154 return fold (build (tcode, ctype, convert (ctype, t1),
4155 convert (ctype, t2)));
4159 case WITH_RECORD_EXPR:
4160 if ((t1 = extract_muldiv (TREE_OPERAND (t, 0), c, code, wide_type)) != 0)
4161 return build (WITH_RECORD_EXPR, TREE_TYPE (t1), t1,
4162 TREE_OPERAND (t, 1));
4165 case LSHIFT_EXPR: case RSHIFT_EXPR:
4166 /* If the second operand is constant, this is a multiplication
4167 or floor division, by a power of two, so we can treat it that
4168 way unless the multiplier or divisor overflows. */
4169 if (TREE_CODE (op1) == INTEGER_CST
4170 /* const_binop may not detect overflow correctly,
4171 so check for it explicitly here. */
4172 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
4173 && TREE_INT_CST_HIGH (op1) == 0
4174 && 0 != (t1 = convert (ctype,
4175 const_binop (LSHIFT_EXPR, size_one_node,
4177 && ! TREE_OVERFLOW (t1))
4178 return extract_muldiv (build (tcode == LSHIFT_EXPR
4179 ? MULT_EXPR : FLOOR_DIV_EXPR,
4180 ctype, convert (ctype, op0), t1),
4181 c, code, wide_type);
4184 case PLUS_EXPR: case MINUS_EXPR:
4185 /* See if we can eliminate the operation on both sides. If we can, we
4186 can return a new PLUS or MINUS. If we can't, the only remaining
4187 cases where we can do anything are if the second operand is a
4189 t1 = extract_muldiv (op0, c, code, wide_type);
4190 t2 = extract_muldiv (op1, c, code, wide_type);
4191 if (t1 != 0 && t2 != 0
4192 && (code == MULT_EXPR
4193 /* If not multiplication, we can only do this if both operands
4194 are divisible by c. */
4195 || (multiple_of_p (ctype, op0, c)
4196 && multiple_of_p (ctype, op1, c))))
4197 return fold (build (tcode, ctype, convert (ctype, t1),
4198 convert (ctype, t2)));
4200 /* If this was a subtraction, negate OP1 and set it to be an addition.
4201 This simplifies the logic below. */
4202 if (tcode == MINUS_EXPR)
4203 tcode = PLUS_EXPR, op1 = negate_expr (op1);
4205 if (TREE_CODE (op1) != INTEGER_CST)
4208 /* If either OP1 or C are negative, this optimization is not safe for
4209 some of the division and remainder types while for others we need
4210 to change the code. */
4211 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
4213 if (code == CEIL_DIV_EXPR)
4214 code = FLOOR_DIV_EXPR;
4215 else if (code == FLOOR_DIV_EXPR)
4216 code = CEIL_DIV_EXPR;
4217 else if (code != MULT_EXPR
4218 && code != CEIL_MOD_EXPR && code != FLOOR_MOD_EXPR)
4222 /* If it's a multiply or a division/modulus operation of a multiple
4223 of our constant, do the operation and verify it doesn't overflow. */
4224 if (code == MULT_EXPR
4225 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4227 op1 = const_binop (code, convert (ctype, op1), convert (ctype, c), 0);
4228 if (op1 == 0 || TREE_OVERFLOW (op1))
4234 /* If we have an unsigned type is not a sizetype, we cannot widen
4235 the operation since it will change the result if the original
4236 computation overflowed. */
4237 if (TREE_UNSIGNED (ctype)
4238 && ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
4242 /* If we were able to eliminate our operation from the first side,
4243 apply our operation to the second side and reform the PLUS. */
4244 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
4245 return fold (build (tcode, ctype, convert (ctype, t1), op1));
4247 /* The last case is if we are a multiply. In that case, we can
4248 apply the distributive law to commute the multiply and addition
4249 if the multiplication of the constants doesn't overflow. */
4250 if (code == MULT_EXPR)
4251 return fold (build (tcode, ctype, fold (build (code, ctype,
4252 convert (ctype, op0),
4253 convert (ctype, c))),
4259 /* We have a special case here if we are doing something like
4260 (C * 8) % 4 since we know that's zero. */
4261 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
4262 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
4263 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
4264 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4265 return omit_one_operand (type, integer_zero_node, op0);
4267 /* ... fall through ... */
4269 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
4270 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
4271 /* If we can extract our operation from the LHS, do so and return a
4272 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
4273 do something only if the second operand is a constant. */
4275 && (t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4276 return fold (build (tcode, ctype, convert (ctype, t1),
4277 convert (ctype, op1)));
4278 else if (tcode == MULT_EXPR && code == MULT_EXPR
4279 && (t1 = extract_muldiv (op1, c, code, wide_type)) != 0)
4280 return fold (build (tcode, ctype, convert (ctype, op0),
4281 convert (ctype, t1)));
4282 else if (TREE_CODE (op1) != INTEGER_CST)
4285 /* If these are the same operation types, we can associate them
4286 assuming no overflow. */
4288 && 0 != (t1 = const_binop (MULT_EXPR, convert (ctype, op1),
4289 convert (ctype, c), 0))
4290 && ! TREE_OVERFLOW (t1))
4291 return fold (build (tcode, ctype, convert (ctype, op0), t1));
4293 /* If these operations "cancel" each other, we have the main
4294 optimizations of this pass, which occur when either constant is a
4295 multiple of the other, in which case we replace this with either an
4296 operation or CODE or TCODE.
4298 If we have an unsigned type that is not a sizetype, we cannot do
4299 this since it will change the result if the original computation
4301 if ((! TREE_UNSIGNED (ctype)
4302 || (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
4304 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
4305 || (tcode == MULT_EXPR
4306 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
4307 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR)))
4309 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4310 return fold (build (tcode, ctype, convert (ctype, op0),
4312 const_binop (TRUNC_DIV_EXPR,
4314 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
4315 return fold (build (code, ctype, convert (ctype, op0),
4317 const_binop (TRUNC_DIV_EXPR,
4329 /* If T contains a COMPOUND_EXPR which was inserted merely to evaluate
4330 S, a SAVE_EXPR, return the expression actually being evaluated. Note
4331 that we may sometimes modify the tree. */
4334 strip_compound_expr (tree t, tree s)
4336 enum tree_code code = TREE_CODE (t);
4338 /* See if this is the COMPOUND_EXPR we want to eliminate. */
4339 if (code == COMPOUND_EXPR && TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR
4340 && TREE_OPERAND (TREE_OPERAND (t, 0), 0) == s)
4341 return TREE_OPERAND (t, 1);
4343 /* See if this is a COND_EXPR or a simple arithmetic operator. We
4344 don't bother handling any other types. */
4345 else if (code == COND_EXPR)
4347 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4348 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4349 TREE_OPERAND (t, 2) = strip_compound_expr (TREE_OPERAND (t, 2), s);
4351 else if (TREE_CODE_CLASS (code) == '1')
4352 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4353 else if (TREE_CODE_CLASS (code) == '<'
4354 || TREE_CODE_CLASS (code) == '2')
4356 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4357 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4363 /* Return a node which has the indicated constant VALUE (either 0 or
4364 1), and is of the indicated TYPE. */
4367 constant_boolean_node (int value, tree type)
4369 if (type == integer_type_node)
4370 return value ? integer_one_node : integer_zero_node;
4371 else if (TREE_CODE (type) == BOOLEAN_TYPE)
4372 return (*lang_hooks.truthvalue_conversion) (value ? integer_one_node :
4376 tree t = build_int_2 (value, 0);
4378 TREE_TYPE (t) = type;
4383 /* Utility function for the following routine, to see how complex a nesting of
4384 COND_EXPRs can be. EXPR is the expression and LIMIT is a count beyond which
4385 we don't care (to avoid spending too much time on complex expressions.). */
4388 count_cond (tree expr, int lim)
4392 if (TREE_CODE (expr) != COND_EXPR)
4397 ctrue = count_cond (TREE_OPERAND (expr, 1), lim - 1);
4398 cfalse = count_cond (TREE_OPERAND (expr, 2), lim - 1 - ctrue);
4399 return MIN (lim, 1 + ctrue + cfalse);
4402 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
4403 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
4404 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
4405 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
4406 COND is the first argument to CODE; otherwise (as in the example
4407 given here), it is the second argument. TYPE is the type of the
4408 original expression. */
4411 fold_binary_op_with_conditional_arg (enum tree_code code, tree type,
4412 tree cond, tree arg, int cond_first_p)
4414 tree test, true_value, false_value;
4415 tree lhs = NULL_TREE;
4416 tree rhs = NULL_TREE;
4417 /* In the end, we'll produce a COND_EXPR. Both arms of the
4418 conditional expression will be binary operations. The left-hand
4419 side of the expression to be executed if the condition is true
4420 will be pointed to by TRUE_LHS. Similarly, the right-hand side
4421 of the expression to be executed if the condition is true will be
4422 pointed to by TRUE_RHS. FALSE_LHS and FALSE_RHS are analogous --
4423 but apply to the expression to be executed if the conditional is
4429 /* These are the codes to use for the left-hand side and right-hand
4430 side of the COND_EXPR. Normally, they are the same as CODE. */
4431 enum tree_code lhs_code = code;
4432 enum tree_code rhs_code = code;
4433 /* And these are the types of the expressions. */
4434 tree lhs_type = type;
4435 tree rhs_type = type;
4440 true_rhs = false_rhs = &arg;
4441 true_lhs = &true_value;
4442 false_lhs = &false_value;
4446 true_lhs = false_lhs = &arg;
4447 true_rhs = &true_value;
4448 false_rhs = &false_value;
4451 if (TREE_CODE (cond) == COND_EXPR)
4453 test = TREE_OPERAND (cond, 0);
4454 true_value = TREE_OPERAND (cond, 1);
4455 false_value = TREE_OPERAND (cond, 2);
4456 /* If this operand throws an expression, then it does not make
4457 sense to try to perform a logical or arithmetic operation
4458 involving it. Instead of building `a + throw 3' for example,
4459 we simply build `a, throw 3'. */
4460 if (VOID_TYPE_P (TREE_TYPE (true_value)))
4464 lhs_code = COMPOUND_EXPR;
4465 lhs_type = void_type_node;
4470 if (VOID_TYPE_P (TREE_TYPE (false_value)))
4474 rhs_code = COMPOUND_EXPR;
4475 rhs_type = void_type_node;
4483 tree testtype = TREE_TYPE (cond);
4485 true_value = convert (testtype, integer_one_node);
4486 false_value = convert (testtype, integer_zero_node);
4489 /* If ARG is complex we want to make sure we only evaluate it once. Though
4490 this is only required if it is volatile, it might be more efficient even
4491 if it is not. However, if we succeed in folding one part to a constant,
4492 we do not need to make this SAVE_EXPR. Since we do this optimization
4493 primarily to see if we do end up with constant and this SAVE_EXPR
4494 interferes with later optimizations, suppressing it when we can is
4497 If we are not in a function, we can't make a SAVE_EXPR, so don't try to
4498 do so. Don't try to see if the result is a constant if an arm is a
4499 COND_EXPR since we get exponential behavior in that case. */
4501 if (saved_expr_p (arg))
4503 else if (lhs == 0 && rhs == 0
4504 && !TREE_CONSTANT (arg)
4505 && (*lang_hooks.decls.global_bindings_p) () == 0
4506 && ((TREE_CODE (arg) != VAR_DECL && TREE_CODE (arg) != PARM_DECL)
4507 || TREE_SIDE_EFFECTS (arg)))
4509 if (TREE_CODE (true_value) != COND_EXPR)
4510 lhs = fold (build (lhs_code, lhs_type, *true_lhs, *true_rhs));
4512 if (TREE_CODE (false_value) != COND_EXPR)
4513 rhs = fold (build (rhs_code, rhs_type, *false_lhs, *false_rhs));
4515 if ((lhs == 0 || ! TREE_CONSTANT (lhs))
4516 && (rhs == 0 || !TREE_CONSTANT (rhs)))
4518 arg = save_expr (arg);
4525 lhs = fold (build (lhs_code, lhs_type, *true_lhs, *true_rhs));
4527 rhs = fold (build (rhs_code, rhs_type, *false_lhs, *false_rhs));
4529 test = fold (build (COND_EXPR, type, test, lhs, rhs));
4532 return build (COMPOUND_EXPR, type,
4533 convert (void_type_node, arg),
4534 strip_compound_expr (test, arg));
4536 return convert (type, test);
4540 /* Subroutine of fold() that checks for the addition of +/- 0.0.
4542 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
4543 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
4544 ADDEND is the same as X.
4546 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
4547 and finite. The problematic cases are when X is zero, and its mode
4548 has signed zeros. In the case of rounding towards -infinity,
4549 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
4550 modes, X + 0 is not the same as X because -0 + 0 is 0. */
4553 fold_real_zero_addition_p (tree type, tree addend, int negate)
4555 if (!real_zerop (addend))
4558 /* Don't allow the fold with -fsignaling-nans. */
4559 if (HONOR_SNANS (TYPE_MODE (type)))
4562 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
4563 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
4566 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
4567 if (TREE_CODE (addend) == REAL_CST
4568 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
4571 /* The mode has signed zeros, and we have to honor their sign.
4572 In this situation, there is only one case we can return true for.
4573 X - 0 is the same as X unless rounding towards -infinity is
4575 return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
4578 /* Subroutine of fold() that checks comparisons of built-in math
4579 functions against real constants.
4581 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
4582 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
4583 is the type of the result and ARG0 and ARG1 are the operands of the
4584 comparison. ARG1 must be a TREE_REAL_CST.
4586 The function returns the constant folded tree if a simplification
4587 can be made, and NULL_TREE otherwise. */
4590 fold_mathfn_compare (enum built_in_function fcode, enum tree_code code,
4591 tree type, tree arg0, tree arg1)
4595 if (fcode == BUILT_IN_SQRT
4596 || fcode == BUILT_IN_SQRTF
4597 || fcode == BUILT_IN_SQRTL)
4599 tree arg = TREE_VALUE (TREE_OPERAND (arg0, 1));
4600 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg0));
4602 c = TREE_REAL_CST (arg1);
4603 if (REAL_VALUE_NEGATIVE (c))
4605 /* sqrt(x) < y is always false, if y is negative. */
4606 if (code == EQ_EXPR || code == LT_EXPR || code == LE_EXPR)
4607 return omit_one_operand (type,
4608 convert (type, integer_zero_node),
4611 /* sqrt(x) > y is always true, if y is negative and we
4612 don't care about NaNs, i.e. negative values of x. */
4613 if (code == NE_EXPR || !HONOR_NANS (mode))
4614 return omit_one_operand (type,
4615 convert (type, integer_one_node),
4618 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
4619 return fold (build (GE_EXPR, type, arg,
4620 build_real (TREE_TYPE (arg), dconst0)));
4622 else if (code == GT_EXPR || code == GE_EXPR)
4626 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
4627 real_convert (&c2, mode, &c2);
4629 if (REAL_VALUE_ISINF (c2))
4631 /* sqrt(x) > y is x == +Inf, when y is very large. */
4632 if (HONOR_INFINITIES (mode))
4633 return fold (build (EQ_EXPR, type, arg,
4634 build_real (TREE_TYPE (arg), c2)));
4636 /* sqrt(x) > y is always false, when y is very large
4637 and we don't care about infinities. */
4638 return omit_one_operand (type,
4639 convert (type, integer_zero_node),
4643 /* sqrt(x) > c is the same as x > c*c. */
4644 return fold (build (code, type, arg,
4645 build_real (TREE_TYPE (arg), c2)));
4647 else if (code == LT_EXPR || code == LE_EXPR)
4651 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
4652 real_convert (&c2, mode, &c2);
4654 if (REAL_VALUE_ISINF (c2))
4656 /* sqrt(x) < y is always true, when y is a very large
4657 value and we don't care about NaNs or Infinities. */
4658 if (! HONOR_NANS (mode) && ! HONOR_INFINITIES (mode))
4659 return omit_one_operand (type,
4660 convert (type, integer_one_node),
4663 /* sqrt(x) < y is x != +Inf when y is very large and we
4664 don't care about NaNs. */
4665 if (! HONOR_NANS (mode))
4666 return fold (build (NE_EXPR, type, arg,
4667 build_real (TREE_TYPE (arg), c2)));
4669 /* sqrt(x) < y is x >= 0 when y is very large and we
4670 don't care about Infinities. */
4671 if (! HONOR_INFINITIES (mode))
4672 return fold (build (GE_EXPR, type, arg,
4673 build_real (TREE_TYPE (arg), dconst0)));
4675 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
4676 if ((*lang_hooks.decls.global_bindings_p) () != 0
4677 || CONTAINS_PLACEHOLDER_P (arg))
4680 arg = save_expr (arg);
4681 return fold (build (TRUTH_ANDIF_EXPR, type,
4682 fold (build (GE_EXPR, type, arg,
4683 build_real (TREE_TYPE (arg),
4685 fold (build (NE_EXPR, type, arg,
4686 build_real (TREE_TYPE (arg),
4690 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
4691 if (! HONOR_NANS (mode))
4692 return fold (build (code, type, arg,
4693 build_real (TREE_TYPE (arg), c2)));
4695 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
4696 if ((*lang_hooks.decls.global_bindings_p) () == 0
4697 && ! CONTAINS_PLACEHOLDER_P (arg))
4699 arg = save_expr (arg);
4700 return fold (build (TRUTH_ANDIF_EXPR, type,
4701 fold (build (GE_EXPR, type, arg,
4702 build_real (TREE_TYPE (arg),
4704 fold (build (code, type, arg,
4705 build_real (TREE_TYPE (arg),
4714 /* Subroutine of fold() that optimizes comparisons against Infinities,
4715 either +Inf or -Inf.
4717 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
4718 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
4719 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
4721 The function returns the constant folded tree if a simplification
4722 can be made, and NULL_TREE otherwise. */
4725 fold_inf_compare (enum tree_code code, tree type, tree arg0, tree arg1)
4727 enum machine_mode mode;
4728 REAL_VALUE_TYPE max;
4732 mode = TYPE_MODE (TREE_TYPE (arg0));
4734 /* For negative infinity swap the sense of the comparison. */
4735 neg = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1));
4737 code = swap_tree_comparison (code);
4742 /* x > +Inf is always false, if with ignore sNANs. */
4743 if (HONOR_SNANS (mode))
4745 return omit_one_operand (type,
4746 convert (type, integer_zero_node),
4750 /* x <= +Inf is always true, if we don't case about NaNs. */
4751 if (! HONOR_NANS (mode))
4752 return omit_one_operand (type,
4753 convert (type, integer_one_node),
4756 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
4757 if ((*lang_hooks.decls.global_bindings_p) () == 0
4758 && ! CONTAINS_PLACEHOLDER_P (arg0))
4760 arg0 = save_expr (arg0);
4761 return fold (build (EQ_EXPR, type, arg0, arg0));
4767 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
4768 real_maxval (&max, neg, mode);
4769 return fold (build (neg ? LT_EXPR : GT_EXPR, type,
4770 arg0, build_real (TREE_TYPE (arg0), max)));
4773 /* x < +Inf is always equal to x <= DBL_MAX. */
4774 real_maxval (&max, neg, mode);
4775 return fold (build (neg ? GE_EXPR : LE_EXPR, type,
4776 arg0, build_real (TREE_TYPE (arg0), max)));
4779 /* x != +Inf is always equal to !(x > DBL_MAX). */
4780 real_maxval (&max, neg, mode);
4781 if (! HONOR_NANS (mode))
4782 return fold (build (neg ? GE_EXPR : LE_EXPR, type,
4783 arg0, build_real (TREE_TYPE (arg0), max)));
4784 temp = fold (build (neg ? LT_EXPR : GT_EXPR, type,
4785 arg0, build_real (TREE_TYPE (arg0), max)));
4786 return fold (build1 (TRUTH_NOT_EXPR, type, temp));
4795 /* If CODE with arguments ARG0 and ARG1 represents a single bit
4796 equality/inequality test, then return a simplified form of
4797 the test using shifts and logical operations. Otherwise return
4798 NULL. TYPE is the desired result type. */
4801 fold_single_bit_test (enum tree_code code, tree arg0, tree arg1,
4804 /* If this is a TRUTH_NOT_EXPR, it may have a single bit test inside
4806 if (code == TRUTH_NOT_EXPR)
4808 code = TREE_CODE (arg0);
4809 if (code != NE_EXPR && code != EQ_EXPR)
4812 /* Extract the arguments of the EQ/NE. */
4813 arg1 = TREE_OPERAND (arg0, 1);
4814 arg0 = TREE_OPERAND (arg0, 0);
4816 /* This requires us to invert the code. */
4817 code = (code == EQ_EXPR ? NE_EXPR : EQ_EXPR);
4820 /* If this is testing a single bit, we can optimize the test. */
4821 if ((code == NE_EXPR || code == EQ_EXPR)
4822 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
4823 && integer_pow2p (TREE_OPERAND (arg0, 1)))
4825 tree inner = TREE_OPERAND (arg0, 0);
4826 tree type = TREE_TYPE (arg0);
4827 int bitnum = tree_log2 (TREE_OPERAND (arg0, 1));
4828 enum machine_mode operand_mode = TYPE_MODE (type);
4830 tree signed_type, unsigned_type;
4833 /* If we have (A & C) != 0 where C is the sign bit of A, convert
4834 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
4835 arg00 = sign_bit_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
4836 if (arg00 != NULL_TREE)
4838 tree stype = (*lang_hooks.types.signed_type) (TREE_TYPE (arg00));
4839 return fold (build (code == EQ_EXPR ? GE_EXPR : LT_EXPR, result_type,
4840 convert (stype, arg00),
4841 convert (stype, integer_zero_node)));
4844 /* Otherwise we have (A & C) != 0 where C is a single bit,
4845 convert that into ((A >> C2) & 1). Where C2 = log2(C).
4846 Similarly for (A & C) == 0. */
4848 /* If INNER is a right shift of a constant and it plus BITNUM does
4849 not overflow, adjust BITNUM and INNER. */
4850 if (TREE_CODE (inner) == RSHIFT_EXPR
4851 && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST
4852 && TREE_INT_CST_HIGH (TREE_OPERAND (inner, 1)) == 0
4853 && bitnum < TYPE_PRECISION (type)
4854 && 0 > compare_tree_int (TREE_OPERAND (inner, 1),
4855 bitnum - TYPE_PRECISION (type)))
4857 bitnum += TREE_INT_CST_LOW (TREE_OPERAND (inner, 1));
4858 inner = TREE_OPERAND (inner, 0);
4861 /* If we are going to be able to omit the AND below, we must do our
4862 operations as unsigned. If we must use the AND, we have a choice.
4863 Normally unsigned is faster, but for some machines signed is. */
4864 ops_unsigned = (bitnum == TYPE_PRECISION (type) - 1 ? 1
4865 #ifdef LOAD_EXTEND_OP
4866 : (LOAD_EXTEND_OP (operand_mode) == SIGN_EXTEND ? 0 : 1)
4872 signed_type = (*lang_hooks.types.type_for_mode) (operand_mode, 0);
4873 unsigned_type = (*lang_hooks.types.type_for_mode) (operand_mode, 1);
4876 inner = build (RSHIFT_EXPR, ops_unsigned ? unsigned_type : signed_type,
4877 inner, size_int (bitnum));
4879 if (code == EQ_EXPR)
4880 inner = build (BIT_XOR_EXPR, ops_unsigned ? unsigned_type : signed_type,
4881 inner, integer_one_node);
4883 /* Put the AND last so it can combine with more things. */
4884 if (bitnum != TYPE_PRECISION (type) - 1)
4885 inner = build (BIT_AND_EXPR, ops_unsigned ? unsigned_type : signed_type,
4886 inner, integer_one_node);
4888 /* Make sure to return the proper type. */
4889 if (TREE_TYPE (inner) != result_type)
4890 inner = convert (result_type, inner);
4897 /* Perform constant folding and related simplification of EXPR.
4898 The related simplifications include x*1 => x, x*0 => 0, etc.,
4899 and application of the associative law.
4900 NOP_EXPR conversions may be removed freely (as long as we
4901 are careful not to change the C type of the overall expression)
4902 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
4903 but we can constant-fold them if they have constant operands. */
4909 tree t1 = NULL_TREE;
4911 tree type = TREE_TYPE (expr);
4912 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
4913 enum tree_code code = TREE_CODE (t);
4914 int kind = TREE_CODE_CLASS (code);
4916 /* WINS will be nonzero when the switch is done
4917 if all operands are constant. */
4920 /* Don't try to process an RTL_EXPR since its operands aren't trees.
4921 Likewise for a SAVE_EXPR that's already been evaluated. */
4922 if (code == RTL_EXPR || (code == SAVE_EXPR && SAVE_EXPR_RTL (t) != 0))
4925 /* Return right away if a constant. */
4929 #ifdef MAX_INTEGER_COMPUTATION_MODE
4930 check_max_integer_computation_mode (expr);
4933 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
4937 /* Special case for conversion ops that can have fixed point args. */
4938 arg0 = TREE_OPERAND (t, 0);
4940 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
4942 STRIP_SIGN_NOPS (arg0);
4944 if (arg0 != 0 && TREE_CODE (arg0) == COMPLEX_CST)
4945 subop = TREE_REALPART (arg0);
4949 if (subop != 0 && TREE_CODE (subop) != INTEGER_CST
4950 && TREE_CODE (subop) != REAL_CST
4952 /* Note that TREE_CONSTANT isn't enough:
4953 static var addresses are constant but we can't
4954 do arithmetic on them. */
4957 else if (IS_EXPR_CODE_CLASS (kind) || kind == 'r')
4959 int len = first_rtl_op (code);
4961 for (i = 0; i < len; i++)
4963 tree op = TREE_OPERAND (t, i);
4967 continue; /* Valid for CALL_EXPR, at least. */
4969 if (kind == '<' || code == RSHIFT_EXPR)
4971 /* Signedness matters here. Perhaps we can refine this
4973 STRIP_SIGN_NOPS (op);
4976 /* Strip any conversions that don't change the mode. */
4979 if (TREE_CODE (op) == COMPLEX_CST)
4980 subop = TREE_REALPART (op);
4984 if (TREE_CODE (subop) != INTEGER_CST
4985 && TREE_CODE (subop) != REAL_CST)
4986 /* Note that TREE_CONSTANT isn't enough:
4987 static var addresses are constant but we can't
4988 do arithmetic on them. */
4998 /* If this is a commutative operation, and ARG0 is a constant, move it
4999 to ARG1 to reduce the number of tests below. */
5000 if ((code == PLUS_EXPR || code == MULT_EXPR || code == MIN_EXPR
5001 || code == MAX_EXPR || code == BIT_IOR_EXPR || code == BIT_XOR_EXPR
5002 || code == BIT_AND_EXPR)
5003 && (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST))
5005 tem = arg0; arg0 = arg1; arg1 = tem;
5007 tem = TREE_OPERAND (t, 0); TREE_OPERAND (t, 0) = TREE_OPERAND (t, 1);
5008 TREE_OPERAND (t, 1) = tem;
5011 /* Now WINS is set as described above,
5012 ARG0 is the first operand of EXPR,
5013 and ARG1 is the second operand (if it has more than one operand).
5015 First check for cases where an arithmetic operation is applied to a
5016 compound, conditional, or comparison operation. Push the arithmetic
5017 operation inside the compound or conditional to see if any folding
5018 can then be done. Convert comparison to conditional for this purpose.
5019 The also optimizes non-constant cases that used to be done in
5022 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
5023 one of the operands is a comparison and the other is a comparison, a
5024 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
5025 code below would make the expression more complex. Change it to a
5026 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
5027 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
5029 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
5030 || code == EQ_EXPR || code == NE_EXPR)
5031 && ((truth_value_p (TREE_CODE (arg0))
5032 && (truth_value_p (TREE_CODE (arg1))
5033 || (TREE_CODE (arg1) == BIT_AND_EXPR
5034 && integer_onep (TREE_OPERAND (arg1, 1)))))
5035 || (truth_value_p (TREE_CODE (arg1))
5036 && (truth_value_p (TREE_CODE (arg0))
5037 || (TREE_CODE (arg0) == BIT_AND_EXPR
5038 && integer_onep (TREE_OPERAND (arg0, 1)))))))
5040 t = fold (build (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
5041 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
5045 if (code == EQ_EXPR)
5046 t = invert_truthvalue (t);
5051 if (TREE_CODE_CLASS (code) == '1')
5053 if (TREE_CODE (arg0) == COMPOUND_EXPR)
5054 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5055 fold (build1 (code, type, TREE_OPERAND (arg0, 1))));
5056 else if (TREE_CODE (arg0) == COND_EXPR)
5058 tree arg01 = TREE_OPERAND (arg0, 1);
5059 tree arg02 = TREE_OPERAND (arg0, 2);
5060 if (! VOID_TYPE_P (TREE_TYPE (arg01)))
5061 arg01 = fold (build1 (code, type, arg01));
5062 if (! VOID_TYPE_P (TREE_TYPE (arg02)))
5063 arg02 = fold (build1 (code, type, arg02));
5064 t = fold (build (COND_EXPR, type, TREE_OPERAND (arg0, 0),
5067 /* If this was a conversion, and all we did was to move into
5068 inside the COND_EXPR, bring it back out. But leave it if
5069 it is a conversion from integer to integer and the
5070 result precision is no wider than a word since such a
5071 conversion is cheap and may be optimized away by combine,
5072 while it couldn't if it were outside the COND_EXPR. Then return
5073 so we don't get into an infinite recursion loop taking the
5074 conversion out and then back in. */
5076 if ((code == NOP_EXPR || code == CONVERT_EXPR
5077 || code == NON_LVALUE_EXPR)
5078 && TREE_CODE (t) == COND_EXPR
5079 && TREE_CODE (TREE_OPERAND (t, 1)) == code
5080 && TREE_CODE (TREE_OPERAND (t, 2)) == code
5081 && ! VOID_TYPE_P (TREE_OPERAND (t, 1))
5082 && ! VOID_TYPE_P (TREE_OPERAND (t, 2))
5083 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))
5084 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 2), 0)))
5085 && ! (INTEGRAL_TYPE_P (TREE_TYPE (t))
5087 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))))
5088 && TYPE_PRECISION (TREE_TYPE (t)) <= BITS_PER_WORD))
5089 t = build1 (code, type,
5091 TREE_TYPE (TREE_OPERAND
5092 (TREE_OPERAND (t, 1), 0)),
5093 TREE_OPERAND (t, 0),
5094 TREE_OPERAND (TREE_OPERAND (t, 1), 0),
5095 TREE_OPERAND (TREE_OPERAND (t, 2), 0)));
5098 else if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<')
5099 return fold (build (COND_EXPR, type, arg0,
5100 fold (build1 (code, type, integer_one_node)),
5101 fold (build1 (code, type, integer_zero_node))));
5103 else if (TREE_CODE_CLASS (code) == '<'
5104 && TREE_CODE (arg0) == COMPOUND_EXPR)
5105 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5106 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
5107 else if (TREE_CODE_CLASS (code) == '<'
5108 && TREE_CODE (arg1) == COMPOUND_EXPR)
5109 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
5110 fold (build (code, type, arg0, TREE_OPERAND (arg1, 1))));
5111 else if (TREE_CODE_CLASS (code) == '2'
5112 || TREE_CODE_CLASS (code) == '<')
5114 if (TREE_CODE (arg1) == COMPOUND_EXPR
5115 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg1, 0))
5116 && ! TREE_SIDE_EFFECTS (arg0))
5117 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
5118 fold (build (code, type,
5119 arg0, TREE_OPERAND (arg1, 1))));
5120 else if ((TREE_CODE (arg1) == COND_EXPR
5121 || (TREE_CODE_CLASS (TREE_CODE (arg1)) == '<'
5122 && TREE_CODE_CLASS (code) != '<'))
5123 && (TREE_CODE (arg0) != COND_EXPR
5124 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
5125 && (! TREE_SIDE_EFFECTS (arg0)
5126 || ((*lang_hooks.decls.global_bindings_p) () == 0
5127 && ! CONTAINS_PLACEHOLDER_P (arg0))))
5129 fold_binary_op_with_conditional_arg (code, type, arg1, arg0,
5130 /*cond_first_p=*/0);
5131 else if (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 (arg0) == COND_EXPR
5135 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
5136 && TREE_CODE_CLASS (code) != '<'))
5137 && (TREE_CODE (arg1) != COND_EXPR
5138 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
5139 && (! TREE_SIDE_EFFECTS (arg1)
5140 || ((*lang_hooks.decls.global_bindings_p) () == 0
5141 && ! CONTAINS_PLACEHOLDER_P (arg1))))
5143 fold_binary_op_with_conditional_arg (code, type, arg0, arg1,
5144 /*cond_first_p=*/1);
5158 return fold (DECL_INITIAL (t));
5163 case FIX_TRUNC_EXPR:
5164 /* Other kinds of FIX are not handled properly by fold_convert. */
5166 if (TREE_TYPE (TREE_OPERAND (t, 0)) == TREE_TYPE (t))
5167 return TREE_OPERAND (t, 0);
5169 /* Handle cases of two conversions in a row. */
5170 if (TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
5171 || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR)
5173 tree inside_type = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5174 tree inter_type = TREE_TYPE (TREE_OPERAND (t, 0));
5175 tree final_type = TREE_TYPE (t);
5176 int inside_int = INTEGRAL_TYPE_P (inside_type);
5177 int inside_ptr = POINTER_TYPE_P (inside_type);
5178 int inside_float = FLOAT_TYPE_P (inside_type);
5179 unsigned int inside_prec = TYPE_PRECISION (inside_type);
5180 int inside_unsignedp = TREE_UNSIGNED (inside_type);
5181 int inter_int = INTEGRAL_TYPE_P (inter_type);
5182 int inter_ptr = POINTER_TYPE_P (inter_type);
5183 int inter_float = FLOAT_TYPE_P (inter_type);
5184 unsigned int inter_prec = TYPE_PRECISION (inter_type);
5185 int inter_unsignedp = TREE_UNSIGNED (inter_type);
5186 int final_int = INTEGRAL_TYPE_P (final_type);
5187 int final_ptr = POINTER_TYPE_P (final_type);
5188 int final_float = FLOAT_TYPE_P (final_type);
5189 unsigned int final_prec = TYPE_PRECISION (final_type);
5190 int final_unsignedp = TREE_UNSIGNED (final_type);
5192 /* In addition to the cases of two conversions in a row
5193 handled below, if we are converting something to its own
5194 type via an object of identical or wider precision, neither
5195 conversion is needed. */
5196 if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (final_type)
5197 && ((inter_int && final_int) || (inter_float && final_float))
5198 && inter_prec >= final_prec)
5199 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5201 /* Likewise, if the intermediate and final types are either both
5202 float or both integer, we don't need the middle conversion if
5203 it is wider than the final type and doesn't change the signedness
5204 (for integers). Avoid this if the final type is a pointer
5205 since then we sometimes need the inner conversion. Likewise if
5206 the outer has a precision not equal to the size of its mode. */
5207 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
5208 || (inter_float && inside_float))
5209 && inter_prec >= inside_prec
5210 && (inter_float || inter_unsignedp == inside_unsignedp)
5211 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
5212 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
5214 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5216 /* If we have a sign-extension of a zero-extended value, we can
5217 replace that by a single zero-extension. */
5218 if (inside_int && inter_int && final_int
5219 && inside_prec < inter_prec && inter_prec < final_prec
5220 && inside_unsignedp && !inter_unsignedp)
5221 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5223 /* Two conversions in a row are not needed unless:
5224 - some conversion is floating-point (overstrict for now), or
5225 - the intermediate type is narrower than both initial and
5227 - the intermediate type and innermost type differ in signedness,
5228 and the outermost type is wider than the intermediate, or
5229 - the initial type is a pointer type and the precisions of the
5230 intermediate and final types differ, or
5231 - the final type is a pointer type and the precisions of the
5232 initial and intermediate types differ. */
5233 if (! inside_float && ! inter_float && ! final_float
5234 && (inter_prec > inside_prec || inter_prec > final_prec)
5235 && ! (inside_int && inter_int
5236 && inter_unsignedp != inside_unsignedp
5237 && inter_prec < final_prec)
5238 && ((inter_unsignedp && inter_prec > inside_prec)
5239 == (final_unsignedp && final_prec > inter_prec))
5240 && ! (inside_ptr && inter_prec != final_prec)
5241 && ! (final_ptr && inside_prec != inter_prec)
5242 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
5243 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
5245 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5248 if (TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR
5249 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t, 0), 1))
5250 /* Detect assigning a bitfield. */
5251 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) == COMPONENT_REF
5252 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 1))))
5254 /* Don't leave an assignment inside a conversion
5255 unless assigning a bitfield. */
5256 tree prev = TREE_OPERAND (t, 0);
5257 TREE_OPERAND (t, 0) = TREE_OPERAND (prev, 1);
5258 /* First do the assignment, then return converted constant. */
5259 t = build (COMPOUND_EXPR, TREE_TYPE (t), prev, fold (t));
5264 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
5265 constants (if x has signed type, the sign bit cannot be set
5266 in c). This folds extension into the BIT_AND_EXPR. */
5267 if (INTEGRAL_TYPE_P (TREE_TYPE (t))
5268 && TREE_CODE (TREE_TYPE (t)) != BOOLEAN_TYPE
5269 && TREE_CODE (TREE_OPERAND (t, 0)) == BIT_AND_EXPR
5270 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 1)) == INTEGER_CST)
5272 tree and = TREE_OPERAND (t, 0);
5273 tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
5276 if (TREE_UNSIGNED (TREE_TYPE (and))
5277 || (TYPE_PRECISION (TREE_TYPE (t))
5278 <= TYPE_PRECISION (TREE_TYPE (and))))
5280 else if (TYPE_PRECISION (TREE_TYPE (and1))
5281 <= HOST_BITS_PER_WIDE_INT
5282 && host_integerp (and1, 1))
5284 unsigned HOST_WIDE_INT cst;
5286 cst = tree_low_cst (and1, 1);
5287 cst &= (HOST_WIDE_INT) -1
5288 << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
5289 change = (cst == 0);
5290 #ifdef LOAD_EXTEND_OP
5292 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
5295 tree uns = (*lang_hooks.types.unsigned_type) (TREE_TYPE (and0));
5296 and0 = convert (uns, and0);
5297 and1 = convert (uns, and1);
5302 return fold (build (BIT_AND_EXPR, TREE_TYPE (t),
5303 convert (TREE_TYPE (t), and0),
5304 convert (TREE_TYPE (t), and1)));
5309 TREE_CONSTANT (t) = TREE_CONSTANT (arg0);
5312 return fold_convert (t, arg0);
5314 case VIEW_CONVERT_EXPR:
5315 if (TREE_CODE (TREE_OPERAND (t, 0)) == VIEW_CONVERT_EXPR)
5316 return build1 (VIEW_CONVERT_EXPR, type,
5317 TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5321 if (TREE_CODE (arg0) == CONSTRUCTOR
5322 && ! type_contains_placeholder_p (TREE_TYPE (arg0)))
5324 tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0));
5331 TREE_CONSTANT (t) = wins;
5337 if (TREE_CODE (arg0) == INTEGER_CST)
5339 unsigned HOST_WIDE_INT low;
5341 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
5342 TREE_INT_CST_HIGH (arg0),
5344 t = build_int_2 (low, high);
5345 TREE_TYPE (t) = type;
5347 = (TREE_OVERFLOW (arg0)
5348 | force_fit_type (t, overflow && !TREE_UNSIGNED (type)));
5349 TREE_CONSTANT_OVERFLOW (t)
5350 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
5352 else if (TREE_CODE (arg0) == REAL_CST)
5353 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
5355 else if (TREE_CODE (arg0) == NEGATE_EXPR)
5356 return TREE_OPERAND (arg0, 0);
5357 /* Convert -((double)float) into (double)(-float). */
5358 else if (TREE_CODE (arg0) == NOP_EXPR
5359 && TREE_CODE (type) == REAL_TYPE)
5361 tree targ0 = strip_float_extensions (arg0);
5363 return convert (type, build1 (NEGATE_EXPR, TREE_TYPE (targ0), targ0));
5367 /* Convert - (a - b) to (b - a) for non-floating-point. */
5368 else if (TREE_CODE (arg0) == MINUS_EXPR
5369 && (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
5370 return build (MINUS_EXPR, type, TREE_OPERAND (arg0, 1),
5371 TREE_OPERAND (arg0, 0));
5373 /* Convert -f(x) into f(-x) where f is sin, tan or atan. */
5374 switch (builtin_mathfn_code (arg0))
5383 case BUILT_IN_ATANF:
5384 case BUILT_IN_ATANL:
5385 if (negate_expr_p (TREE_VALUE (TREE_OPERAND (arg0, 1))))
5387 tree fndecl, arg, arglist;
5389 fndecl = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
5390 arg = TREE_VALUE (TREE_OPERAND (arg0, 1));
5391 arg = fold (build1 (NEGATE_EXPR, type, arg));
5392 arglist = build_tree_list (NULL_TREE, arg);
5393 return build_function_call_expr (fndecl, arglist);
5405 if (TREE_CODE (arg0) == INTEGER_CST)
5407 /* If the value is unsigned, then the absolute value is
5408 the same as the ordinary value. */
5409 if (TREE_UNSIGNED (type))
5411 /* Similarly, if the value is non-negative. */
5412 else if (INT_CST_LT (integer_minus_one_node, arg0))
5414 /* If the value is negative, then the absolute value is
5418 unsigned HOST_WIDE_INT low;
5420 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
5421 TREE_INT_CST_HIGH (arg0),
5423 t = build_int_2 (low, high);
5424 TREE_TYPE (t) = type;
5426 = (TREE_OVERFLOW (arg0)
5427 | force_fit_type (t, overflow));
5428 TREE_CONSTANT_OVERFLOW (t)
5429 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
5432 else if (TREE_CODE (arg0) == REAL_CST)
5434 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
5435 t = build_real (type,
5436 REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
5439 else if (TREE_CODE (arg0) == NEGATE_EXPR)
5440 return fold (build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0)));
5441 /* Convert fabs((double)float) into (double)fabsf(float). */
5442 else if (TREE_CODE (arg0) == NOP_EXPR
5443 && TREE_CODE (type) == REAL_TYPE)
5445 tree targ0 = strip_float_extensions (arg0);
5447 return convert (type, fold (build1 (ABS_EXPR, TREE_TYPE (targ0),
5450 else if (tree_expr_nonnegative_p (arg0))
5455 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
5456 return convert (type, arg0);
5457 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
5458 return build (COMPLEX_EXPR, type,
5459 TREE_OPERAND (arg0, 0),
5460 negate_expr (TREE_OPERAND (arg0, 1)));
5461 else if (TREE_CODE (arg0) == COMPLEX_CST)
5462 return build_complex (type, TREE_REALPART (arg0),
5463 negate_expr (TREE_IMAGPART (arg0)));
5464 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
5465 return fold (build (TREE_CODE (arg0), type,
5466 fold (build1 (CONJ_EXPR, type,
5467 TREE_OPERAND (arg0, 0))),
5468 fold (build1 (CONJ_EXPR,
5469 type, TREE_OPERAND (arg0, 1)))));
5470 else if (TREE_CODE (arg0) == CONJ_EXPR)
5471 return TREE_OPERAND (arg0, 0);
5477 t = build_int_2 (~ TREE_INT_CST_LOW (arg0),
5478 ~ TREE_INT_CST_HIGH (arg0));
5479 TREE_TYPE (t) = type;
5480 force_fit_type (t, 0);
5481 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg0);
5482 TREE_CONSTANT_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (arg0);
5484 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
5485 return TREE_OPERAND (arg0, 0);
5489 /* A + (-B) -> A - B */
5490 if (TREE_CODE (arg1) == NEGATE_EXPR)
5491 return fold (build (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5492 /* (-A) + B -> B - A */
5493 if (TREE_CODE (arg0) == NEGATE_EXPR)
5494 return fold (build (MINUS_EXPR, type, arg1, TREE_OPERAND (arg0, 0)));
5495 else if (! FLOAT_TYPE_P (type))
5497 if (integer_zerop (arg1))
5498 return non_lvalue (convert (type, arg0));
5500 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
5501 with a constant, and the two constants have no bits in common,
5502 we should treat this as a BIT_IOR_EXPR since this may produce more
5504 if (TREE_CODE (arg0) == BIT_AND_EXPR
5505 && TREE_CODE (arg1) == BIT_AND_EXPR
5506 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5507 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
5508 && integer_zerop (const_binop (BIT_AND_EXPR,
5509 TREE_OPERAND (arg0, 1),
5510 TREE_OPERAND (arg1, 1), 0)))
5512 code = BIT_IOR_EXPR;
5516 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
5517 (plus (plus (mult) (mult)) (foo)) so that we can
5518 take advantage of the factoring cases below. */
5519 if ((TREE_CODE (arg0) == PLUS_EXPR
5520 && TREE_CODE (arg1) == MULT_EXPR)
5521 || (TREE_CODE (arg1) == PLUS_EXPR
5522 && TREE_CODE (arg0) == MULT_EXPR))
5524 tree parg0, parg1, parg, marg;
5526 if (TREE_CODE (arg0) == PLUS_EXPR)
5527 parg = arg0, marg = arg1;
5529 parg = arg1, marg = arg0;
5530 parg0 = TREE_OPERAND (parg, 0);
5531 parg1 = TREE_OPERAND (parg, 1);
5535 if (TREE_CODE (parg0) == MULT_EXPR
5536 && TREE_CODE (parg1) != MULT_EXPR)
5537 return fold (build (PLUS_EXPR, type,
5538 fold (build (PLUS_EXPR, type,
5539 convert (type, parg0),
5540 convert (type, marg))),
5541 convert (type, parg1)));
5542 if (TREE_CODE (parg0) != MULT_EXPR
5543 && TREE_CODE (parg1) == MULT_EXPR)
5544 return fold (build (PLUS_EXPR, type,
5545 fold (build (PLUS_EXPR, type,
5546 convert (type, parg1),
5547 convert (type, marg))),
5548 convert (type, parg0)));
5551 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR)
5553 tree arg00, arg01, arg10, arg11;
5554 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
5556 /* (A * C) + (B * C) -> (A+B) * C.
5557 We are most concerned about the case where C is a constant,
5558 but other combinations show up during loop reduction. Since
5559 it is not difficult, try all four possibilities. */
5561 arg00 = TREE_OPERAND (arg0, 0);
5562 arg01 = TREE_OPERAND (arg0, 1);
5563 arg10 = TREE_OPERAND (arg1, 0);
5564 arg11 = TREE_OPERAND (arg1, 1);
5567 if (operand_equal_p (arg01, arg11, 0))
5568 same = arg01, alt0 = arg00, alt1 = arg10;
5569 else if (operand_equal_p (arg00, arg10, 0))
5570 same = arg00, alt0 = arg01, alt1 = arg11;
5571 else if (operand_equal_p (arg00, arg11, 0))
5572 same = arg00, alt0 = arg01, alt1 = arg10;
5573 else if (operand_equal_p (arg01, arg10, 0))
5574 same = arg01, alt0 = arg00, alt1 = arg11;
5576 /* No identical multiplicands; see if we can find a common
5577 power-of-two factor in non-power-of-two multiplies. This
5578 can help in multi-dimensional array access. */
5579 else if (TREE_CODE (arg01) == INTEGER_CST
5580 && TREE_CODE (arg11) == INTEGER_CST
5581 && TREE_INT_CST_HIGH (arg01) == 0
5582 && TREE_INT_CST_HIGH (arg11) == 0)
5584 HOST_WIDE_INT int01, int11, tmp;
5585 int01 = TREE_INT_CST_LOW (arg01);
5586 int11 = TREE_INT_CST_LOW (arg11);
5588 /* Move min of absolute values to int11. */
5589 if ((int01 >= 0 ? int01 : -int01)
5590 < (int11 >= 0 ? int11 : -int11))
5592 tmp = int01, int01 = int11, int11 = tmp;
5593 alt0 = arg00, arg00 = arg10, arg10 = alt0;
5594 alt0 = arg01, arg01 = arg11, arg11 = alt0;
5597 if (exact_log2 (int11) > 0 && int01 % int11 == 0)
5599 alt0 = fold (build (MULT_EXPR, type, arg00,
5600 build_int_2 (int01 / int11, 0)));
5607 return fold (build (MULT_EXPR, type,
5608 fold (build (PLUS_EXPR, type, alt0, alt1)),
5613 /* See if ARG1 is zero and X + ARG1 reduces to X. */
5614 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
5615 return non_lvalue (convert (type, arg0));
5617 /* Likewise if the operands are reversed. */
5618 else if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
5619 return non_lvalue (convert (type, arg1));
5622 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
5623 is a rotate of A by C1 bits. */
5624 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
5625 is a rotate of A by B bits. */
5627 enum tree_code code0, code1;
5628 code0 = TREE_CODE (arg0);
5629 code1 = TREE_CODE (arg1);
5630 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
5631 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
5632 && operand_equal_p (TREE_OPERAND (arg0, 0),
5633 TREE_OPERAND (arg1, 0), 0)
5634 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5636 tree tree01, tree11;
5637 enum tree_code code01, code11;
5639 tree01 = TREE_OPERAND (arg0, 1);
5640 tree11 = TREE_OPERAND (arg1, 1);
5641 STRIP_NOPS (tree01);
5642 STRIP_NOPS (tree11);
5643 code01 = TREE_CODE (tree01);
5644 code11 = TREE_CODE (tree11);
5645 if (code01 == INTEGER_CST
5646 && code11 == INTEGER_CST
5647 && TREE_INT_CST_HIGH (tree01) == 0
5648 && TREE_INT_CST_HIGH (tree11) == 0
5649 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
5650 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
5651 return build (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
5652 code0 == LSHIFT_EXPR ? tree01 : tree11);
5653 else if (code11 == MINUS_EXPR)
5655 tree tree110, tree111;
5656 tree110 = TREE_OPERAND (tree11, 0);
5657 tree111 = TREE_OPERAND (tree11, 1);
5658 STRIP_NOPS (tree110);
5659 STRIP_NOPS (tree111);
5660 if (TREE_CODE (tree110) == INTEGER_CST
5661 && 0 == compare_tree_int (tree110,
5663 (TREE_TYPE (TREE_OPERAND
5665 && operand_equal_p (tree01, tree111, 0))
5666 return build ((code0 == LSHIFT_EXPR
5669 type, TREE_OPERAND (arg0, 0), tree01);
5671 else if (code01 == MINUS_EXPR)
5673 tree tree010, tree011;
5674 tree010 = TREE_OPERAND (tree01, 0);
5675 tree011 = TREE_OPERAND (tree01, 1);
5676 STRIP_NOPS (tree010);
5677 STRIP_NOPS (tree011);
5678 if (TREE_CODE (tree010) == INTEGER_CST
5679 && 0 == compare_tree_int (tree010,
5681 (TREE_TYPE (TREE_OPERAND
5683 && operand_equal_p (tree11, tree011, 0))
5684 return build ((code0 != LSHIFT_EXPR
5687 type, TREE_OPERAND (arg0, 0), tree11);
5693 /* In most languages, can't associate operations on floats through
5694 parentheses. Rather than remember where the parentheses were, we
5695 don't associate floats at all. It shouldn't matter much. However,
5696 associating multiplications is only very slightly inaccurate, so do
5697 that if -funsafe-math-optimizations is specified. */
5700 && (! FLOAT_TYPE_P (type)
5701 || (flag_unsafe_math_optimizations && code == MULT_EXPR)))
5703 tree var0, con0, lit0, minus_lit0;
5704 tree var1, con1, lit1, minus_lit1;
5706 /* Split both trees into variables, constants, and literals. Then
5707 associate each group together, the constants with literals,
5708 then the result with variables. This increases the chances of
5709 literals being recombined later and of generating relocatable
5710 expressions for the sum of a constant and literal. */
5711 var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
5712 var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
5713 code == MINUS_EXPR);
5715 /* Only do something if we found more than two objects. Otherwise,
5716 nothing has changed and we risk infinite recursion. */
5717 if (2 < ((var0 != 0) + (var1 != 0)
5718 + (con0 != 0) + (con1 != 0)
5719 + (lit0 != 0) + (lit1 != 0)
5720 + (minus_lit0 != 0) + (minus_lit1 != 0)))
5722 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
5723 if (code == MINUS_EXPR)
5726 var0 = associate_trees (var0, var1, code, type);
5727 con0 = associate_trees (con0, con1, code, type);
5728 lit0 = associate_trees (lit0, lit1, code, type);
5729 minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
5731 /* Preserve the MINUS_EXPR if the negative part of the literal is
5732 greater than the positive part. Otherwise, the multiplicative
5733 folding code (i.e extract_muldiv) may be fooled in case
5734 unsigned constants are subtracted, like in the following
5735 example: ((X*2 + 4) - 8U)/2. */
5736 if (minus_lit0 && lit0)
5738 if (tree_int_cst_lt (lit0, minus_lit0))
5740 minus_lit0 = associate_trees (minus_lit0, lit0,
5746 lit0 = associate_trees (lit0, minus_lit0,
5754 return convert (type, associate_trees (var0, minus_lit0,
5758 con0 = associate_trees (con0, minus_lit0,
5760 return convert (type, associate_trees (var0, con0,
5765 con0 = associate_trees (con0, lit0, code, type);
5766 return convert (type, associate_trees (var0, con0, code, type));
5772 t1 = const_binop (code, arg0, arg1, 0);
5773 if (t1 != NULL_TREE)
5775 /* The return value should always have
5776 the same type as the original expression. */
5777 if (TREE_TYPE (t1) != TREE_TYPE (t))
5778 t1 = convert (TREE_TYPE (t), t1);
5785 /* A - (-B) -> A + B */
5786 if (TREE_CODE (arg1) == NEGATE_EXPR)
5787 return fold (build (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5788 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
5789 if (TREE_CODE (arg0) == NEGATE_EXPR
5790 && (FLOAT_TYPE_P (type)
5791 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv))
5792 && negate_expr_p (arg1)
5793 && (! TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
5794 && (! TREE_SIDE_EFFECTS (arg1) || TREE_CONSTANT (arg0)))
5795 return fold (build (MINUS_EXPR, type, negate_expr (arg1),
5796 TREE_OPERAND (arg0, 0)));
5798 if (! FLOAT_TYPE_P (type))
5800 if (! wins && integer_zerop (arg0))
5801 return negate_expr (convert (type, arg1));
5802 if (integer_zerop (arg1))
5803 return non_lvalue (convert (type, arg0));
5805 /* (A * C) - (B * C) -> (A-B) * C. Since we are most concerned
5806 about the case where C is a constant, just try one of the
5807 four possibilities. */
5809 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR
5810 && operand_equal_p (TREE_OPERAND (arg0, 1),
5811 TREE_OPERAND (arg1, 1), 0))
5812 return fold (build (MULT_EXPR, type,
5813 fold (build (MINUS_EXPR, type,
5814 TREE_OPERAND (arg0, 0),
5815 TREE_OPERAND (arg1, 0))),
5816 TREE_OPERAND (arg0, 1)));
5818 /* Fold A - (A & B) into ~B & A. */
5819 if (!TREE_SIDE_EFFECTS (arg0)
5820 && TREE_CODE (arg1) == BIT_AND_EXPR)
5822 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
5823 return fold (build (BIT_AND_EXPR, type,
5824 fold (build1 (BIT_NOT_EXPR, type,
5825 TREE_OPERAND (arg1, 0))),
5827 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
5828 return fold (build (BIT_AND_EXPR, type,
5829 fold (build1 (BIT_NOT_EXPR, type,
5830 TREE_OPERAND (arg1, 1))),
5835 /* See if ARG1 is zero and X - ARG1 reduces to X. */
5836 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
5837 return non_lvalue (convert (type, arg0));
5839 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
5840 ARG0 is zero and X + ARG0 reduces to X, since that would mean
5841 (-ARG1 + ARG0) reduces to -ARG1. */
5842 else if (!wins && fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
5843 return negate_expr (convert (type, arg1));
5845 /* Fold &x - &x. This can happen from &x.foo - &x.
5846 This is unsafe for certain floats even in non-IEEE formats.
5847 In IEEE, it is unsafe because it does wrong for NaNs.
5848 Also note that operand_equal_p is always false if an operand
5851 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
5852 && operand_equal_p (arg0, arg1, 0))
5853 return convert (type, integer_zero_node);
5858 /* (-A) * (-B) -> A * B */
5859 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR)
5860 return fold (build (MULT_EXPR, type, TREE_OPERAND (arg0, 0),
5861 TREE_OPERAND (arg1, 0)));
5863 if (! FLOAT_TYPE_P (type))
5865 if (integer_zerop (arg1))
5866 return omit_one_operand (type, arg1, arg0);
5867 if (integer_onep (arg1))
5868 return non_lvalue (convert (type, arg0));
5870 /* (a * (1 << b)) is (a << b) */
5871 if (TREE_CODE (arg1) == LSHIFT_EXPR
5872 && integer_onep (TREE_OPERAND (arg1, 0)))
5873 return fold (build (LSHIFT_EXPR, type, arg0,
5874 TREE_OPERAND (arg1, 1)));
5875 if (TREE_CODE (arg0) == LSHIFT_EXPR
5876 && integer_onep (TREE_OPERAND (arg0, 0)))
5877 return fold (build (LSHIFT_EXPR, type, arg1,
5878 TREE_OPERAND (arg0, 1)));
5880 if (TREE_CODE (arg1) == INTEGER_CST
5881 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0),
5882 convert (type, arg1),
5884 return convert (type, tem);
5889 /* Maybe fold x * 0 to 0. The expressions aren't the same
5890 when x is NaN, since x * 0 is also NaN. Nor are they the
5891 same in modes with signed zeros, since multiplying a
5892 negative value by 0 gives -0, not +0. */
5893 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
5894 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
5895 && real_zerop (arg1))
5896 return omit_one_operand (type, arg1, arg0);
5897 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
5898 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
5899 && real_onep (arg1))
5900 return non_lvalue (convert (type, arg0));
5902 /* Transform x * -1.0 into -x. */
5903 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
5904 && real_minus_onep (arg1))
5905 return fold (build1 (NEGATE_EXPR, type, arg0));
5908 if (! wins && real_twop (arg1)
5909 && (*lang_hooks.decls.global_bindings_p) () == 0
5910 && ! CONTAINS_PLACEHOLDER_P (arg0))
5912 tree arg = save_expr (arg0);
5913 return fold (build (PLUS_EXPR, type, arg, arg));
5916 if (flag_unsafe_math_optimizations)
5918 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
5919 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
5921 /* Optimizations of sqrt(...)*sqrt(...). */
5922 if ((fcode0 == BUILT_IN_SQRT && fcode1 == BUILT_IN_SQRT)
5923 || (fcode0 == BUILT_IN_SQRTF && fcode1 == BUILT_IN_SQRTF)
5924 || (fcode0 == BUILT_IN_SQRTL && fcode1 == BUILT_IN_SQRTL))
5926 tree sqrtfn, arg, arglist;
5927 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
5928 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
5930 /* Optimize sqrt(x)*sqrt(x) as x. */
5931 if (operand_equal_p (arg00, arg10, 0)
5932 && ! HONOR_SNANS (TYPE_MODE (type)))
5935 /* Optimize sqrt(x)*sqrt(y) as sqrt(x*y). */
5936 sqrtfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
5937 arg = fold (build (MULT_EXPR, type, arg00, arg10));
5938 arglist = build_tree_list (NULL_TREE, arg);
5939 return build_function_call_expr (sqrtfn, arglist);
5942 /* Optimize exp(x)*exp(y) as exp(x+y). */
5943 if ((fcode0 == BUILT_IN_EXP && fcode1 == BUILT_IN_EXP)
5944 || (fcode0 == BUILT_IN_EXPF && fcode1 == BUILT_IN_EXPF)
5945 || (fcode0 == BUILT_IN_EXPL && fcode1 == BUILT_IN_EXPL))
5947 tree expfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
5948 tree arg = build (PLUS_EXPR, type,
5949 TREE_VALUE (TREE_OPERAND (arg0, 1)),
5950 TREE_VALUE (TREE_OPERAND (arg1, 1)));
5951 tree arglist = build_tree_list (NULL_TREE, fold (arg));
5952 return build_function_call_expr (expfn, arglist);
5955 /* Optimizations of pow(...)*pow(...). */
5956 if ((fcode0 == BUILT_IN_POW && fcode1 == BUILT_IN_POW)
5957 || (fcode0 == BUILT_IN_POWF && fcode1 == BUILT_IN_POWF)
5958 || (fcode0 == BUILT_IN_POWL && fcode1 == BUILT_IN_POWL))
5960 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
5961 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
5963 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
5964 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
5967 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
5968 if (operand_equal_p (arg01, arg11, 0))
5970 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
5971 tree arg = build (MULT_EXPR, type, arg00, arg10);
5972 tree arglist = tree_cons (NULL_TREE, fold (arg),
5973 build_tree_list (NULL_TREE,
5975 return build_function_call_expr (powfn, arglist);
5978 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
5979 if (operand_equal_p (arg00, arg10, 0))
5981 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
5982 tree arg = fold (build (PLUS_EXPR, type, arg01, arg11));
5983 tree arglist = tree_cons (NULL_TREE, arg00,
5984 build_tree_list (NULL_TREE,
5986 return build_function_call_expr (powfn, arglist);
5990 /* Optimize tan(x)*cos(x) as sin(x). */
5991 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_COS)
5992 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_COSF)
5993 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_COSL)
5994 || (fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_TAN)
5995 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_TANF)
5996 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_TANL))
5997 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
5998 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
6006 sinfn = implicit_built_in_decls[BUILT_IN_SIN];
6010 sinfn = implicit_built_in_decls[BUILT_IN_SINF];
6014 sinfn = implicit_built_in_decls[BUILT_IN_SINL];
6020 if (sinfn != NULL_TREE)
6021 return build_function_call_expr (sinfn,
6022 TREE_OPERAND (arg0, 1));
6030 if (integer_all_onesp (arg1))
6031 return omit_one_operand (type, arg1, arg0);
6032 if (integer_zerop (arg1))
6033 return non_lvalue (convert (type, arg0));
6034 t1 = distribute_bit_expr (code, type, arg0, arg1);
6035 if (t1 != NULL_TREE)
6038 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
6040 This results in more efficient code for machines without a NAND
6041 instruction. Combine will canonicalize to the first form
6042 which will allow use of NAND instructions provided by the
6043 backend if they exist. */
6044 if (TREE_CODE (arg0) == BIT_NOT_EXPR
6045 && TREE_CODE (arg1) == BIT_NOT_EXPR)
6047 return fold (build1 (BIT_NOT_EXPR, type,
6048 build (BIT_AND_EXPR, type,
6049 TREE_OPERAND (arg0, 0),
6050 TREE_OPERAND (arg1, 0))));
6053 /* See if this can be simplified into a rotate first. If that
6054 is unsuccessful continue in the association code. */
6058 if (integer_zerop (arg1))
6059 return non_lvalue (convert (type, arg0));
6060 if (integer_all_onesp (arg1))
6061 return fold (build1 (BIT_NOT_EXPR, type, arg0));
6063 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
6064 with a constant, and the two constants have no bits in common,
6065 we should treat this as a BIT_IOR_EXPR since this may produce more
6067 if (TREE_CODE (arg0) == BIT_AND_EXPR
6068 && TREE_CODE (arg1) == BIT_AND_EXPR
6069 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6070 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
6071 && integer_zerop (const_binop (BIT_AND_EXPR,
6072 TREE_OPERAND (arg0, 1),
6073 TREE_OPERAND (arg1, 1), 0)))
6075 code = BIT_IOR_EXPR;
6079 /* See if this can be simplified into a rotate first. If that
6080 is unsuccessful continue in the association code. */
6085 if (integer_all_onesp (arg1))
6086 return non_lvalue (convert (type, arg0));
6087 if (integer_zerop (arg1))
6088 return omit_one_operand (type, arg1, arg0);
6089 t1 = distribute_bit_expr (code, type, arg0, arg1);
6090 if (t1 != NULL_TREE)
6092 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
6093 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
6094 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
6097 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
6099 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
6100 && (~TREE_INT_CST_LOW (arg1)
6101 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
6102 return build1 (NOP_EXPR, type, TREE_OPERAND (arg0, 0));
6105 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
6107 This results in more efficient code for machines without a NOR
6108 instruction. Combine will canonicalize to the first form
6109 which will allow use of NOR instructions provided by the
6110 backend if they exist. */
6111 if (TREE_CODE (arg0) == BIT_NOT_EXPR
6112 && TREE_CODE (arg1) == BIT_NOT_EXPR)
6114 return fold (build1 (BIT_NOT_EXPR, type,
6115 build (BIT_IOR_EXPR, type,
6116 TREE_OPERAND (arg0, 0),
6117 TREE_OPERAND (arg1, 0))));
6122 case BIT_ANDTC_EXPR:
6123 if (integer_all_onesp (arg0))
6124 return non_lvalue (convert (type, arg1));
6125 if (integer_zerop (arg0))
6126 return omit_one_operand (type, arg0, arg1);
6127 if (TREE_CODE (arg1) == INTEGER_CST)
6129 arg1 = fold (build1 (BIT_NOT_EXPR, type, arg1));
6130 code = BIT_AND_EXPR;
6136 /* Don't touch a floating-point divide by zero unless the mode
6137 of the constant can represent infinity. */
6138 if (TREE_CODE (arg1) == REAL_CST
6139 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
6140 && real_zerop (arg1))
6143 /* (-A) / (-B) -> A / B */
6144 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR)
6145 return fold (build (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
6146 TREE_OPERAND (arg1, 0)));
6148 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
6149 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
6150 && real_onep (arg1))
6151 return non_lvalue (convert (type, arg0));
6153 /* If ARG1 is a constant, we can convert this to a multiply by the
6154 reciprocal. This does not have the same rounding properties,
6155 so only do this if -funsafe-math-optimizations. We can actually
6156 always safely do it if ARG1 is a power of two, but it's hard to
6157 tell if it is or not in a portable manner. */
6158 if (TREE_CODE (arg1) == REAL_CST)
6160 if (flag_unsafe_math_optimizations
6161 && 0 != (tem = const_binop (code, build_real (type, dconst1),
6163 return fold (build (MULT_EXPR, type, arg0, tem));
6164 /* Find the reciprocal if optimizing and the result is exact. */
6168 r = TREE_REAL_CST (arg1);
6169 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
6171 tem = build_real (type, r);
6172 return fold (build (MULT_EXPR, type, arg0, tem));
6176 /* Convert A/B/C to A/(B*C). */
6177 if (flag_unsafe_math_optimizations
6178 && TREE_CODE (arg0) == RDIV_EXPR)
6180 return fold (build (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
6181 build (MULT_EXPR, type, TREE_OPERAND (arg0, 1),
6184 /* Convert A/(B/C) to (A/B)*C. */
6185 if (flag_unsafe_math_optimizations
6186 && TREE_CODE (arg1) == RDIV_EXPR)
6188 return fold (build (MULT_EXPR, type,
6189 build (RDIV_EXPR, type, arg0,
6190 TREE_OPERAND (arg1, 0)),
6191 TREE_OPERAND (arg1, 1)));
6194 if (flag_unsafe_math_optimizations)
6196 enum built_in_function fcode = builtin_mathfn_code (arg1);
6197 /* Optimize x/exp(y) into x*exp(-y). */
6198 if (fcode == BUILT_IN_EXP
6199 || fcode == BUILT_IN_EXPF
6200 || fcode == BUILT_IN_EXPL)
6202 tree expfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
6203 tree arg = build1 (NEGATE_EXPR, type,
6204 TREE_VALUE (TREE_OPERAND (arg1, 1)));
6205 tree arglist = build_tree_list (NULL_TREE, fold (arg));
6206 arg1 = build_function_call_expr (expfn, arglist);
6207 return fold (build (MULT_EXPR, type, arg0, arg1));
6210 /* Optimize x/pow(y,z) into x*pow(y,-z). */
6211 if (fcode == BUILT_IN_POW
6212 || fcode == BUILT_IN_POWF
6213 || fcode == BUILT_IN_POWL)
6215 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
6216 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
6217 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1, 1)));
6218 tree neg11 = fold (build1 (NEGATE_EXPR, type, arg11));
6219 tree arglist = tree_cons(NULL_TREE, arg10,
6220 build_tree_list (NULL_TREE, neg11));
6221 arg1 = build_function_call_expr (powfn, arglist);
6222 return fold (build (MULT_EXPR, type, arg0, arg1));
6226 if (flag_unsafe_math_optimizations)
6228 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
6229 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
6231 /* Optimize sin(x)/cos(x) as tan(x). */
6232 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_COS)
6233 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_COSF)
6234 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_COSL))
6235 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
6236 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
6240 if (fcode0 == BUILT_IN_SIN)
6241 tanfn = implicit_built_in_decls[BUILT_IN_TAN];
6242 else if (fcode0 == BUILT_IN_SINF)
6243 tanfn = implicit_built_in_decls[BUILT_IN_TANF];
6244 else if (fcode0 == BUILT_IN_SINL)
6245 tanfn = implicit_built_in_decls[BUILT_IN_TANL];
6249 if (tanfn != NULL_TREE)
6250 return build_function_call_expr (tanfn,
6251 TREE_OPERAND (arg0, 1));
6254 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
6255 if (((fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_SIN)
6256 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_SINF)
6257 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_SINL))
6258 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
6259 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
6263 if (fcode0 == BUILT_IN_COS)
6264 tanfn = implicit_built_in_decls[BUILT_IN_TAN];
6265 else if (fcode0 == BUILT_IN_COSF)
6266 tanfn = implicit_built_in_decls[BUILT_IN_TANF];
6267 else if (fcode0 == BUILT_IN_COSL)
6268 tanfn = implicit_built_in_decls[BUILT_IN_TANL];
6272 if (tanfn != NULL_TREE)
6274 tree tmp = TREE_OPERAND (arg0, 1);
6275 tmp = build_function_call_expr (tanfn, tmp);
6276 return fold (build (RDIV_EXPR, type,
6277 build_real (type, dconst1),
6284 case TRUNC_DIV_EXPR:
6285 case ROUND_DIV_EXPR:
6286 case FLOOR_DIV_EXPR:
6288 case EXACT_DIV_EXPR:
6289 if (integer_onep (arg1))
6290 return non_lvalue (convert (type, arg0));
6291 if (integer_zerop (arg1))
6294 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
6295 operation, EXACT_DIV_EXPR.
6297 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
6298 At one time others generated faster code, it's not clear if they do
6299 after the last round to changes to the DIV code in expmed.c. */
6300 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
6301 && multiple_of_p (type, arg0, arg1))
6302 return fold (build (EXACT_DIV_EXPR, type, arg0, arg1));
6304 if (TREE_CODE (arg1) == INTEGER_CST
6305 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
6307 return convert (type, tem);
6312 case FLOOR_MOD_EXPR:
6313 case ROUND_MOD_EXPR:
6314 case TRUNC_MOD_EXPR:
6315 if (integer_onep (arg1))
6316 return omit_one_operand (type, integer_zero_node, arg0);
6317 if (integer_zerop (arg1))
6320 if (TREE_CODE (arg1) == INTEGER_CST
6321 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
6323 return convert (type, tem);
6329 if (integer_all_onesp (arg0))
6330 return omit_one_operand (type, arg0, arg1);
6334 /* Optimize -1 >> x for arithmetic right shifts. */
6335 if (integer_all_onesp (arg0) && ! TREE_UNSIGNED (type))
6336 return omit_one_operand (type, arg0, arg1);
6337 /* ... fall through ... */
6341 if (integer_zerop (arg1))
6342 return non_lvalue (convert (type, arg0));
6343 if (integer_zerop (arg0))
6344 return omit_one_operand (type, arg0, arg1);
6346 /* Since negative shift count is not well-defined,
6347 don't try to compute it in the compiler. */
6348 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
6350 /* Rewrite an LROTATE_EXPR by a constant into an
6351 RROTATE_EXPR by a new constant. */
6352 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
6354 TREE_SET_CODE (t, RROTATE_EXPR);
6355 code = RROTATE_EXPR;
6356 TREE_OPERAND (t, 1) = arg1
6359 convert (TREE_TYPE (arg1),
6360 build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type)), 0)),
6362 if (tree_int_cst_sgn (arg1) < 0)
6366 /* If we have a rotate of a bit operation with the rotate count and
6367 the second operand of the bit operation both constant,
6368 permute the two operations. */
6369 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
6370 && (TREE_CODE (arg0) == BIT_AND_EXPR
6371 || TREE_CODE (arg0) == BIT_ANDTC_EXPR
6372 || TREE_CODE (arg0) == BIT_IOR_EXPR
6373 || TREE_CODE (arg0) == BIT_XOR_EXPR)
6374 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
6375 return fold (build (TREE_CODE (arg0), type,
6376 fold (build (code, type,
6377 TREE_OPERAND (arg0, 0), arg1)),
6378 fold (build (code, type,
6379 TREE_OPERAND (arg0, 1), arg1))));
6381 /* Two consecutive rotates adding up to the width of the mode can
6383 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
6384 && TREE_CODE (arg0) == RROTATE_EXPR
6385 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6386 && TREE_INT_CST_HIGH (arg1) == 0
6387 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
6388 && ((TREE_INT_CST_LOW (arg1)
6389 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
6390 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type))))
6391 return TREE_OPERAND (arg0, 0);
6396 if (operand_equal_p (arg0, arg1, 0))
6397 return omit_one_operand (type, arg0, arg1);
6398 if (INTEGRAL_TYPE_P (type)
6399 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), 1))
6400 return omit_one_operand (type, arg1, arg0);
6404 if (operand_equal_p (arg0, arg1, 0))
6405 return omit_one_operand (type, arg0, arg1);
6406 if (INTEGRAL_TYPE_P (type)
6407 && TYPE_MAX_VALUE (type)
6408 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), 1))
6409 return omit_one_operand (type, arg1, arg0);
6412 case TRUTH_NOT_EXPR:
6413 /* Note that the operand of this must be an int
6414 and its values must be 0 or 1.
6415 ("true" is a fixed value perhaps depending on the language,
6416 but we don't handle values other than 1 correctly yet.) */
6417 tem = invert_truthvalue (arg0);
6418 /* Avoid infinite recursion. */
6419 if (TREE_CODE (tem) == TRUTH_NOT_EXPR)
6421 tem = fold_single_bit_test (code, arg0, arg1, type);
6426 return convert (type, tem);
6428 case TRUTH_ANDIF_EXPR:
6429 /* Note that the operands of this must be ints
6430 and their values must be 0 or 1.
6431 ("true" is a fixed value perhaps depending on the language.) */
6432 /* If first arg is constant zero, return it. */
6433 if (integer_zerop (arg0))
6434 return convert (type, arg0);
6435 case TRUTH_AND_EXPR:
6436 /* If either arg is constant true, drop it. */
6437 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
6438 return non_lvalue (convert (type, arg1));
6439 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
6440 /* Preserve sequence points. */
6441 && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
6442 return non_lvalue (convert (type, arg0));
6443 /* If second arg is constant zero, result is zero, but first arg
6444 must be evaluated. */
6445 if (integer_zerop (arg1))
6446 return omit_one_operand (type, arg1, arg0);
6447 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
6448 case will be handled here. */
6449 if (integer_zerop (arg0))
6450 return omit_one_operand (type, arg0, arg1);
6453 /* We only do these simplifications if we are optimizing. */
6457 /* Check for things like (A || B) && (A || C). We can convert this
6458 to A || (B && C). Note that either operator can be any of the four
6459 truth and/or operations and the transformation will still be
6460 valid. Also note that we only care about order for the
6461 ANDIF and ORIF operators. If B contains side effects, this
6462 might change the truth-value of A. */
6463 if (TREE_CODE (arg0) == TREE_CODE (arg1)
6464 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
6465 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
6466 || TREE_CODE (arg0) == TRUTH_AND_EXPR
6467 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
6468 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
6470 tree a00 = TREE_OPERAND (arg0, 0);
6471 tree a01 = TREE_OPERAND (arg0, 1);
6472 tree a10 = TREE_OPERAND (arg1, 0);
6473 tree a11 = TREE_OPERAND (arg1, 1);
6474 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
6475 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
6476 && (code == TRUTH_AND_EXPR
6477 || code == TRUTH_OR_EXPR));
6479 if (operand_equal_p (a00, a10, 0))
6480 return fold (build (TREE_CODE (arg0), type, a00,
6481 fold (build (code, type, a01, a11))));
6482 else if (commutative && operand_equal_p (a00, a11, 0))
6483 return fold (build (TREE_CODE (arg0), type, a00,
6484 fold (build (code, type, a01, a10))));
6485 else if (commutative && operand_equal_p (a01, a10, 0))
6486 return fold (build (TREE_CODE (arg0), type, a01,
6487 fold (build (code, type, a00, a11))));
6489 /* This case if tricky because we must either have commutative
6490 operators or else A10 must not have side-effects. */
6492 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
6493 && operand_equal_p (a01, a11, 0))
6494 return fold (build (TREE_CODE (arg0), type,
6495 fold (build (code, type, a00, a10)),
6499 /* See if we can build a range comparison. */
6500 if (0 != (tem = fold_range_test (t)))
6503 /* Check for the possibility of merging component references. If our
6504 lhs is another similar operation, try to merge its rhs with our
6505 rhs. Then try to merge our lhs and rhs. */
6506 if (TREE_CODE (arg0) == code
6507 && 0 != (tem = fold_truthop (code, type,
6508 TREE_OPERAND (arg0, 1), arg1)))
6509 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6511 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
6516 case TRUTH_ORIF_EXPR:
6517 /* Note that the operands of this must be ints
6518 and their values must be 0 or true.
6519 ("true" is a fixed value perhaps depending on the language.) */
6520 /* If first arg is constant true, return it. */
6521 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
6522 return convert (type, arg0);
6524 /* If either arg is constant zero, drop it. */
6525 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
6526 return non_lvalue (convert (type, arg1));
6527 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
6528 /* Preserve sequence points. */
6529 && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
6530 return non_lvalue (convert (type, arg0));
6531 /* If second arg is constant true, result is true, but we must
6532 evaluate first arg. */
6533 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
6534 return omit_one_operand (type, arg1, arg0);
6535 /* Likewise for first arg, but note this only occurs here for
6537 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
6538 return omit_one_operand (type, arg0, arg1);
6541 case TRUTH_XOR_EXPR:
6542 /* If either arg is constant zero, drop it. */
6543 if (integer_zerop (arg0))
6544 return non_lvalue (convert (type, arg1));
6545 if (integer_zerop (arg1))
6546 return non_lvalue (convert (type, arg0));
6547 /* If either arg is constant true, this is a logical inversion. */
6548 if (integer_onep (arg0))
6549 return non_lvalue (convert (type, invert_truthvalue (arg1)));
6550 if (integer_onep (arg1))
6551 return non_lvalue (convert (type, invert_truthvalue (arg0)));
6560 /* If one arg is a real or integer constant, put it last. */
6561 if ((TREE_CODE (arg0) == INTEGER_CST
6562 && TREE_CODE (arg1) != INTEGER_CST)
6563 || (TREE_CODE (arg0) == REAL_CST
6564 && TREE_CODE (arg0) != REAL_CST))
6566 TREE_OPERAND (t, 0) = arg1;
6567 TREE_OPERAND (t, 1) = arg0;
6568 arg0 = TREE_OPERAND (t, 0);
6569 arg1 = TREE_OPERAND (t, 1);
6570 code = swap_tree_comparison (code);
6571 TREE_SET_CODE (t, code);
6574 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
6576 tree targ0 = strip_float_extensions (arg0);
6577 tree targ1 = strip_float_extensions (arg1);
6578 tree newtype = TREE_TYPE (targ0);
6580 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
6581 newtype = TREE_TYPE (targ1);
6583 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
6584 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
6585 return fold (build (code, type, convert (newtype, targ0),
6586 convert (newtype, targ1)));
6588 /* (-a) CMP (-b) -> b CMP a */
6589 if (TREE_CODE (arg0) == NEGATE_EXPR
6590 && TREE_CODE (arg1) == NEGATE_EXPR)
6591 return fold (build (code, type, TREE_OPERAND (arg1, 0),
6592 TREE_OPERAND (arg0, 0)));
6594 if (TREE_CODE (arg1) == REAL_CST)
6596 REAL_VALUE_TYPE cst;
6597 cst = TREE_REAL_CST (arg1);
6599 /* (-a) CMP CST -> a swap(CMP) (-CST) */
6600 if (TREE_CODE (arg0) == NEGATE_EXPR)
6602 fold (build (swap_tree_comparison (code), type,
6603 TREE_OPERAND (arg0, 0),
6604 build_real (TREE_TYPE (arg1),
6605 REAL_VALUE_NEGATE (cst))));
6607 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
6608 /* a CMP (-0) -> a CMP 0 */
6609 if (REAL_VALUE_MINUS_ZERO (cst))
6610 return fold (build (code, type, arg0,
6611 build_real (TREE_TYPE (arg1), dconst0)));
6613 /* x != NaN is always true, other ops are always false. */
6614 if (REAL_VALUE_ISNAN (cst)
6615 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))))
6617 t = (code == NE_EXPR) ? integer_one_node : integer_zero_node;
6618 return omit_one_operand (type, convert (type, t), arg0);
6621 /* Fold comparisons against infinity. */
6622 if (REAL_VALUE_ISINF (cst))
6624 tem = fold_inf_compare (code, type, arg0, arg1);
6625 if (tem != NULL_TREE)
6630 /* If this is a comparison of a real constant with a PLUS_EXPR
6631 or a MINUS_EXPR of a real constant, we can convert it into a
6632 comparison with a revised real constant as long as no overflow
6633 occurs when unsafe_math_optimizations are enabled. */
6634 if (flag_unsafe_math_optimizations
6635 && TREE_CODE (arg1) == REAL_CST
6636 && (TREE_CODE (arg0) == PLUS_EXPR
6637 || TREE_CODE (arg0) == MINUS_EXPR)
6638 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
6639 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
6640 ? MINUS_EXPR : PLUS_EXPR,
6641 arg1, TREE_OPERAND (arg0, 1), 0))
6642 && ! TREE_CONSTANT_OVERFLOW (tem))
6643 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6645 /* Likewise, we can simplify a comparison of a real constant with
6646 a MINUS_EXPR whose first operand is also a real constant, i.e.
6647 (c1 - x) < c2 becomes x > c1-c2. */
6648 if (flag_unsafe_math_optimizations
6649 && TREE_CODE (arg1) == REAL_CST
6650 && TREE_CODE (arg0) == MINUS_EXPR
6651 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST
6652 && 0 != (tem = const_binop (MINUS_EXPR, TREE_OPERAND (arg0, 0),
6654 && ! TREE_CONSTANT_OVERFLOW (tem))
6655 return fold (build (swap_tree_comparison (code), type,
6656 TREE_OPERAND (arg0, 1), tem));
6658 /* Fold comparisons against built-in math functions. */
6659 if (TREE_CODE (arg1) == REAL_CST
6660 && flag_unsafe_math_optimizations
6661 && ! flag_errno_math)
6663 enum built_in_function fcode = builtin_mathfn_code (arg0);
6665 if (fcode != END_BUILTINS)
6667 tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
6668 if (tem != NULL_TREE)
6674 /* Convert foo++ == CONST into ++foo == CONST + INCR.
6675 First, see if one arg is constant; find the constant arg
6676 and the other one. */
6678 tree constop = 0, varop = NULL_TREE;
6679 int constopnum = -1;
6681 if (TREE_CONSTANT (arg1))
6682 constopnum = 1, constop = arg1, varop = arg0;
6683 if (TREE_CONSTANT (arg0))
6684 constopnum = 0, constop = arg0, varop = arg1;
6686 if (constop && TREE_CODE (varop) == POSTINCREMENT_EXPR)
6688 /* This optimization is invalid for ordered comparisons
6689 if CONST+INCR overflows or if foo+incr might overflow.
6690 This optimization is invalid for floating point due to rounding.
6691 For pointer types we assume overflow doesn't happen. */
6692 if (POINTER_TYPE_P (TREE_TYPE (varop))
6693 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
6694 && (code == EQ_EXPR || code == NE_EXPR)))
6697 = fold (build (PLUS_EXPR, TREE_TYPE (varop),
6698 constop, TREE_OPERAND (varop, 1)));
6700 /* Do not overwrite the current varop to be a preincrement,
6701 create a new node so that we won't confuse our caller who
6702 might create trees and throw them away, reusing the
6703 arguments that they passed to build. This shows up in
6704 the THEN or ELSE parts of ?: being postincrements. */
6705 varop = build (PREINCREMENT_EXPR, TREE_TYPE (varop),
6706 TREE_OPERAND (varop, 0),
6707 TREE_OPERAND (varop, 1));
6709 /* If VAROP is a reference to a bitfield, we must mask
6710 the constant by the width of the field. */
6711 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
6712 && DECL_BIT_FIELD(TREE_OPERAND
6713 (TREE_OPERAND (varop, 0), 1)))
6716 = TREE_INT_CST_LOW (DECL_SIZE
6718 (TREE_OPERAND (varop, 0), 1)));
6719 tree mask, unsigned_type;
6720 unsigned int precision;
6721 tree folded_compare;
6723 /* First check whether the comparison would come out
6724 always the same. If we don't do that we would
6725 change the meaning with the masking. */
6726 if (constopnum == 0)
6727 folded_compare = fold (build (code, type, constop,
6728 TREE_OPERAND (varop, 0)));
6730 folded_compare = fold (build (code, type,
6731 TREE_OPERAND (varop, 0),
6733 if (integer_zerop (folded_compare)
6734 || integer_onep (folded_compare))
6735 return omit_one_operand (type, folded_compare, varop);
6737 unsigned_type = (*lang_hooks.types.type_for_size)(size, 1);
6738 precision = TYPE_PRECISION (unsigned_type);
6739 mask = build_int_2 (~0, ~0);
6740 TREE_TYPE (mask) = unsigned_type;
6741 force_fit_type (mask, 0);
6742 mask = const_binop (RSHIFT_EXPR, mask,
6743 size_int (precision - size), 0);
6744 newconst = fold (build (BIT_AND_EXPR,
6745 TREE_TYPE (varop), newconst,
6746 convert (TREE_TYPE (varop),
6750 t = build (code, type,
6751 (constopnum == 0) ? newconst : varop,
6752 (constopnum == 1) ? newconst : varop);
6756 else if (constop && TREE_CODE (varop) == POSTDECREMENT_EXPR)
6758 if (POINTER_TYPE_P (TREE_TYPE (varop))
6759 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
6760 && (code == EQ_EXPR || code == NE_EXPR)))
6763 = fold (build (MINUS_EXPR, TREE_TYPE (varop),
6764 constop, TREE_OPERAND (varop, 1)));
6766 /* Do not overwrite the current varop to be a predecrement,
6767 create a new node so that we won't confuse our caller who
6768 might create trees and throw them away, reusing the
6769 arguments that they passed to build. This shows up in
6770 the THEN or ELSE parts of ?: being postdecrements. */
6771 varop = build (PREDECREMENT_EXPR, TREE_TYPE (varop),
6772 TREE_OPERAND (varop, 0),
6773 TREE_OPERAND (varop, 1));
6775 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
6776 && DECL_BIT_FIELD(TREE_OPERAND
6777 (TREE_OPERAND (varop, 0), 1)))
6780 = TREE_INT_CST_LOW (DECL_SIZE
6782 (TREE_OPERAND (varop, 0), 1)));
6783 tree mask, unsigned_type;
6784 unsigned int precision;
6785 tree folded_compare;
6787 if (constopnum == 0)
6788 folded_compare = fold (build (code, type, constop,
6789 TREE_OPERAND (varop, 0)));
6791 folded_compare = fold (build (code, type,
6792 TREE_OPERAND (varop, 0),
6794 if (integer_zerop (folded_compare)
6795 || integer_onep (folded_compare))
6796 return omit_one_operand (type, folded_compare, varop);
6798 unsigned_type = (*lang_hooks.types.type_for_size)(size, 1);
6799 precision = TYPE_PRECISION (unsigned_type);
6800 mask = build_int_2 (~0, ~0);
6801 TREE_TYPE (mask) = TREE_TYPE (varop);
6802 force_fit_type (mask, 0);
6803 mask = const_binop (RSHIFT_EXPR, mask,
6804 size_int (precision - size), 0);
6805 newconst = fold (build (BIT_AND_EXPR,
6806 TREE_TYPE (varop), newconst,
6807 convert (TREE_TYPE (varop),
6811 t = build (code, type,
6812 (constopnum == 0) ? newconst : varop,
6813 (constopnum == 1) ? newconst : varop);
6819 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
6820 This transformation affects the cases which are handled in later
6821 optimizations involving comparisons with non-negative constants. */
6822 if (TREE_CODE (arg1) == INTEGER_CST
6823 && TREE_CODE (arg0) != INTEGER_CST
6824 && tree_int_cst_sgn (arg1) > 0)
6830 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6831 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6836 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6837 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6845 /* Comparisons with the highest or lowest possible integer of
6846 the specified size will have known values. */
6848 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1)));
6850 if (TREE_CODE (arg1) == INTEGER_CST
6851 && ! TREE_CONSTANT_OVERFLOW (arg1)
6852 && width <= HOST_BITS_PER_WIDE_INT
6853 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
6854 || POINTER_TYPE_P (TREE_TYPE (arg1))))
6856 unsigned HOST_WIDE_INT signed_max;
6857 unsigned HOST_WIDE_INT max, min;
6859 signed_max = ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1;
6861 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
6863 max = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
6869 min = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
6872 if (TREE_INT_CST_HIGH (arg1) == 0
6873 && TREE_INT_CST_LOW (arg1) == max)
6877 return omit_one_operand (type,
6878 convert (type, integer_zero_node),
6882 TREE_SET_CODE (t, EQ_EXPR);
6885 return omit_one_operand (type,
6886 convert (type, integer_one_node),
6890 TREE_SET_CODE (t, NE_EXPR);
6893 /* The GE_EXPR and LT_EXPR cases above are not normally
6894 reached because of previous transformations. */
6899 else if (TREE_INT_CST_HIGH (arg1) == 0
6900 && TREE_INT_CST_LOW (arg1) == max - 1)
6905 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
6906 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6910 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
6911 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6916 else if (TREE_INT_CST_HIGH (arg1) == (min ? -1 : 0)
6917 && TREE_INT_CST_LOW (arg1) == min)
6921 return omit_one_operand (type,
6922 convert (type, integer_zero_node),
6926 TREE_SET_CODE (t, EQ_EXPR);
6930 return omit_one_operand (type,
6931 convert (type, integer_one_node),
6935 TREE_SET_CODE (t, NE_EXPR);
6941 else if (TREE_INT_CST_HIGH (arg1) == (min ? -1 : 0)
6942 && TREE_INT_CST_LOW (arg1) == min + 1)
6947 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6948 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6952 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6953 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6959 else if (TREE_INT_CST_HIGH (arg1) == 0
6960 && TREE_INT_CST_LOW (arg1) == signed_max
6961 && TREE_UNSIGNED (TREE_TYPE (arg1))
6962 /* signed_type does not work on pointer types. */
6963 && INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
6965 /* The following case also applies to X < signed_max+1
6966 and X >= signed_max+1 because previous transformations. */
6967 if (code == LE_EXPR || code == GT_EXPR)
6970 st0 = (*lang_hooks.types.signed_type) (TREE_TYPE (arg0));
6971 st1 = (*lang_hooks.types.signed_type) (TREE_TYPE (arg1));
6973 (build (code == LE_EXPR ? GE_EXPR: LT_EXPR,
6974 type, convert (st0, arg0),
6975 convert (st1, integer_zero_node)));
6981 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
6982 a MINUS_EXPR of a constant, we can convert it into a comparison with
6983 a revised constant as long as no overflow occurs. */
6984 if ((code == EQ_EXPR || code == NE_EXPR)
6985 && TREE_CODE (arg1) == INTEGER_CST
6986 && (TREE_CODE (arg0) == PLUS_EXPR
6987 || TREE_CODE (arg0) == MINUS_EXPR)
6988 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6989 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
6990 ? MINUS_EXPR : PLUS_EXPR,
6991 arg1, TREE_OPERAND (arg0, 1), 0))
6992 && ! TREE_CONSTANT_OVERFLOW (tem))
6993 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6995 /* Similarly for a NEGATE_EXPR. */
6996 else if ((code == EQ_EXPR || code == NE_EXPR)
6997 && TREE_CODE (arg0) == NEGATE_EXPR
6998 && TREE_CODE (arg1) == INTEGER_CST
6999 && 0 != (tem = negate_expr (arg1))
7000 && TREE_CODE (tem) == INTEGER_CST
7001 && ! TREE_CONSTANT_OVERFLOW (tem))
7002 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
7004 /* If we have X - Y == 0, we can convert that to X == Y and similarly
7005 for !=. Don't do this for ordered comparisons due to overflow. */
7006 else if ((code == NE_EXPR || code == EQ_EXPR)
7007 && integer_zerop (arg1) && TREE_CODE (arg0) == MINUS_EXPR)
7008 return fold (build (code, type,
7009 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1)));
7011 /* If we are widening one operand of an integer comparison,
7012 see if the other operand is similarly being widened. Perhaps we
7013 can do the comparison in the narrower type. */
7014 else if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
7015 && TREE_CODE (arg0) == NOP_EXPR
7016 && (tem = get_unwidened (arg0, NULL_TREE)) != arg0
7017 && (t1 = get_unwidened (arg1, TREE_TYPE (tem))) != 0
7018 && (TREE_TYPE (t1) == TREE_TYPE (tem)
7019 || (TREE_CODE (t1) == INTEGER_CST
7020 && int_fits_type_p (t1, TREE_TYPE (tem)))))
7021 return fold (build (code, type, tem, convert (TREE_TYPE (tem), t1)));
7023 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
7024 constant, we can simplify it. */
7025 else if (TREE_CODE (arg1) == INTEGER_CST
7026 && (TREE_CODE (arg0) == MIN_EXPR
7027 || TREE_CODE (arg0) == MAX_EXPR)
7028 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
7029 return optimize_minmax_comparison (t);
7031 /* If we are comparing an ABS_EXPR with a constant, we can
7032 convert all the cases into explicit comparisons, but they may
7033 well not be faster than doing the ABS and one comparison.
7034 But ABS (X) <= C is a range comparison, which becomes a subtraction
7035 and a comparison, and is probably faster. */
7036 else if (code == LE_EXPR && TREE_CODE (arg1) == INTEGER_CST
7037 && TREE_CODE (arg0) == ABS_EXPR
7038 && ! TREE_SIDE_EFFECTS (arg0)
7039 && (0 != (tem = negate_expr (arg1)))
7040 && TREE_CODE (tem) == INTEGER_CST
7041 && ! TREE_CONSTANT_OVERFLOW (tem))
7042 return fold (build (TRUTH_ANDIF_EXPR, type,
7043 build (GE_EXPR, type, TREE_OPERAND (arg0, 0), tem),
7044 build (LE_EXPR, type,
7045 TREE_OPERAND (arg0, 0), arg1)));
7047 /* If this is an EQ or NE comparison with zero and ARG0 is
7048 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
7049 two operations, but the latter can be done in one less insn
7050 on machines that have only two-operand insns or on which a
7051 constant cannot be the first operand. */
7052 if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR)
7053 && TREE_CODE (arg0) == BIT_AND_EXPR)
7055 if (TREE_CODE (TREE_OPERAND (arg0, 0)) == LSHIFT_EXPR
7056 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 0), 0)))
7058 fold (build (code, type,
7059 build (BIT_AND_EXPR, TREE_TYPE (arg0),
7061 TREE_TYPE (TREE_OPERAND (arg0, 0)),
7062 TREE_OPERAND (arg0, 1),
7063 TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)),
7064 convert (TREE_TYPE (arg0),
7067 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
7068 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
7070 fold (build (code, type,
7071 build (BIT_AND_EXPR, TREE_TYPE (arg0),
7073 TREE_TYPE (TREE_OPERAND (arg0, 1)),
7074 TREE_OPERAND (arg0, 0),
7075 TREE_OPERAND (TREE_OPERAND (arg0, 1), 1)),
7076 convert (TREE_TYPE (arg0),
7081 /* If this is an NE or EQ comparison of zero against the result of a
7082 signed MOD operation whose second operand is a power of 2, make
7083 the MOD operation unsigned since it is simpler and equivalent. */
7084 if ((code == NE_EXPR || code == EQ_EXPR)
7085 && integer_zerop (arg1)
7086 && ! TREE_UNSIGNED (TREE_TYPE (arg0))
7087 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
7088 || TREE_CODE (arg0) == CEIL_MOD_EXPR
7089 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
7090 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
7091 && integer_pow2p (TREE_OPERAND (arg0, 1)))
7093 tree newtype = (*lang_hooks.types.unsigned_type) (TREE_TYPE (arg0));
7094 tree newmod = build (TREE_CODE (arg0), newtype,
7095 convert (newtype, TREE_OPERAND (arg0, 0)),
7096 convert (newtype, TREE_OPERAND (arg0, 1)));
7098 return build (code, type, newmod, convert (newtype, arg1));
7101 /* If this is an NE comparison of zero with an AND of one, remove the
7102 comparison since the AND will give the correct value. */
7103 if (code == NE_EXPR && integer_zerop (arg1)
7104 && TREE_CODE (arg0) == BIT_AND_EXPR
7105 && integer_onep (TREE_OPERAND (arg0, 1)))
7106 return convert (type, arg0);
7108 /* If we have (A & C) == C where C is a power of 2, convert this into
7109 (A & C) != 0. Similarly for NE_EXPR. */
7110 if ((code == EQ_EXPR || code == NE_EXPR)
7111 && TREE_CODE (arg0) == BIT_AND_EXPR
7112 && integer_pow2p (TREE_OPERAND (arg0, 1))
7113 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
7114 return fold (build (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
7115 arg0, integer_zero_node));
7117 /* If we have (A & C) != 0 or (A & C) == 0 and C is a power of
7118 2, then fold the expression into shifts and logical operations. */
7119 tem = fold_single_bit_test (code, arg0, arg1, type);
7123 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
7124 and similarly for >= into !=. */
7125 if ((code == LT_EXPR || code == GE_EXPR)
7126 && TREE_UNSIGNED (TREE_TYPE (arg0))
7127 && TREE_CODE (arg1) == LSHIFT_EXPR
7128 && integer_onep (TREE_OPERAND (arg1, 0)))
7129 return build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
7130 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
7131 TREE_OPERAND (arg1, 1)),
7132 convert (TREE_TYPE (arg0), integer_zero_node));
7134 else if ((code == LT_EXPR || code == GE_EXPR)
7135 && TREE_UNSIGNED (TREE_TYPE (arg0))
7136 && (TREE_CODE (arg1) == NOP_EXPR
7137 || TREE_CODE (arg1) == CONVERT_EXPR)
7138 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
7139 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
7141 build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
7142 convert (TREE_TYPE (arg0),
7143 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
7144 TREE_OPERAND (TREE_OPERAND (arg1, 0), 1))),
7145 convert (TREE_TYPE (arg0), integer_zero_node));
7147 /* Simplify comparison of something with itself. (For IEEE
7148 floating-point, we can only do some of these simplifications.) */
7149 if (operand_equal_p (arg0, arg1, 0))
7156 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
7157 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
7158 return constant_boolean_node (1, type);
7160 TREE_SET_CODE (t, code);
7164 /* For NE, we can only do this simplification if integer
7165 or we don't honor IEEE floating point NaNs. */
7166 if (FLOAT_TYPE_P (TREE_TYPE (arg0))
7167 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
7169 /* ... fall through ... */
7172 return constant_boolean_node (0, type);
7178 /* If we are comparing an expression that just has comparisons
7179 of two integer values, arithmetic expressions of those comparisons,
7180 and constants, we can simplify it. There are only three cases
7181 to check: the two values can either be equal, the first can be
7182 greater, or the second can be greater. Fold the expression for
7183 those three values. Since each value must be 0 or 1, we have
7184 eight possibilities, each of which corresponds to the constant 0
7185 or 1 or one of the six possible comparisons.
7187 This handles common cases like (a > b) == 0 but also handles
7188 expressions like ((x > y) - (y > x)) > 0, which supposedly
7189 occur in macroized code. */
7191 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
7193 tree cval1 = 0, cval2 = 0;
7196 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
7197 /* Don't handle degenerate cases here; they should already
7198 have been handled anyway. */
7199 && cval1 != 0 && cval2 != 0
7200 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
7201 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
7202 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
7203 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
7204 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
7205 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
7206 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
7208 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
7209 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
7211 /* We can't just pass T to eval_subst in case cval1 or cval2
7212 was the same as ARG1. */
7215 = fold (build (code, type,
7216 eval_subst (arg0, cval1, maxval, cval2, minval),
7219 = fold (build (code, type,
7220 eval_subst (arg0, cval1, maxval, cval2, maxval),
7223 = fold (build (code, type,
7224 eval_subst (arg0, cval1, minval, cval2, maxval),
7227 /* All three of these results should be 0 or 1. Confirm they
7228 are. Then use those values to select the proper code
7231 if ((integer_zerop (high_result)
7232 || integer_onep (high_result))
7233 && (integer_zerop (equal_result)
7234 || integer_onep (equal_result))
7235 && (integer_zerop (low_result)
7236 || integer_onep (low_result)))
7238 /* Make a 3-bit mask with the high-order bit being the
7239 value for `>', the next for '=', and the low for '<'. */
7240 switch ((integer_onep (high_result) * 4)
7241 + (integer_onep (equal_result) * 2)
7242 + integer_onep (low_result))
7246 return omit_one_operand (type, integer_zero_node, arg0);
7267 return omit_one_operand (type, integer_one_node, arg0);
7270 t = build (code, type, cval1, cval2);
7272 return save_expr (t);
7279 /* If this is a comparison of a field, we may be able to simplify it. */
7280 if (((TREE_CODE (arg0) == COMPONENT_REF
7281 && (*lang_hooks.can_use_bit_fields_p) ())
7282 || TREE_CODE (arg0) == BIT_FIELD_REF)
7283 && (code == EQ_EXPR || code == NE_EXPR)
7284 /* Handle the constant case even without -O
7285 to make sure the warnings are given. */
7286 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
7288 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
7292 /* If this is a comparison of complex values and either or both sides
7293 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
7294 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
7295 This may prevent needless evaluations. */
7296 if ((code == EQ_EXPR || code == NE_EXPR)
7297 && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
7298 && (TREE_CODE (arg0) == COMPLEX_EXPR
7299 || TREE_CODE (arg1) == COMPLEX_EXPR
7300 || TREE_CODE (arg0) == COMPLEX_CST
7301 || TREE_CODE (arg1) == COMPLEX_CST))
7303 tree subtype = TREE_TYPE (TREE_TYPE (arg0));
7304 tree real0, imag0, real1, imag1;
7306 arg0 = save_expr (arg0);
7307 arg1 = save_expr (arg1);
7308 real0 = fold (build1 (REALPART_EXPR, subtype, arg0));
7309 imag0 = fold (build1 (IMAGPART_EXPR, subtype, arg0));
7310 real1 = fold (build1 (REALPART_EXPR, subtype, arg1));
7311 imag1 = fold (build1 (IMAGPART_EXPR, subtype, arg1));
7313 return fold (build ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR
7316 fold (build (code, type, real0, real1)),
7317 fold (build (code, type, imag0, imag1))));
7320 /* Optimize comparisons of strlen vs zero to a compare of the
7321 first character of the string vs zero. To wit,
7322 strlen(ptr) == 0 => *ptr == 0
7323 strlen(ptr) != 0 => *ptr != 0
7324 Other cases should reduce to one of these two (or a constant)
7325 due to the return value of strlen being unsigned. */
7326 if ((code == EQ_EXPR || code == NE_EXPR)
7327 && integer_zerop (arg1)
7328 && TREE_CODE (arg0) == CALL_EXPR
7329 && TREE_CODE (TREE_OPERAND (arg0, 0)) == ADDR_EXPR)
7331 tree fndecl = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7334 if (TREE_CODE (fndecl) == FUNCTION_DECL
7335 && DECL_BUILT_IN (fndecl)
7336 && DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_MD
7337 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
7338 && (arglist = TREE_OPERAND (arg0, 1))
7339 && TREE_CODE (TREE_TYPE (TREE_VALUE (arglist))) == POINTER_TYPE
7340 && ! TREE_CHAIN (arglist))
7341 return fold (build (code, type,
7342 build1 (INDIRECT_REF, char_type_node,
7343 TREE_VALUE(arglist)),
7344 integer_zero_node));
7347 /* From here on, the only cases we handle are when the result is
7348 known to be a constant.
7350 To compute GT, swap the arguments and do LT.
7351 To compute GE, do LT and invert the result.
7352 To compute LE, swap the arguments, do LT and invert the result.
7353 To compute NE, do EQ and invert the result.
7355 Therefore, the code below must handle only EQ and LT. */
7357 if (code == LE_EXPR || code == GT_EXPR)
7359 tem = arg0, arg0 = arg1, arg1 = tem;
7360 code = swap_tree_comparison (code);
7363 /* Note that it is safe to invert for real values here because we
7364 will check below in the one case that it matters. */
7368 if (code == NE_EXPR || code == GE_EXPR)
7371 code = invert_tree_comparison (code);
7374 /* Compute a result for LT or EQ if args permit;
7375 otherwise return T. */
7376 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
7378 if (code == EQ_EXPR)
7379 t1 = build_int_2 (tree_int_cst_equal (arg0, arg1), 0);
7381 t1 = build_int_2 ((TREE_UNSIGNED (TREE_TYPE (arg0))
7382 ? INT_CST_LT_UNSIGNED (arg0, arg1)
7383 : INT_CST_LT (arg0, arg1)),
7387 #if 0 /* This is no longer useful, but breaks some real code. */
7388 /* Assume a nonexplicit constant cannot equal an explicit one,
7389 since such code would be undefined anyway.
7390 Exception: on sysvr4, using #pragma weak,
7391 a label can come out as 0. */
7392 else if (TREE_CODE (arg1) == INTEGER_CST
7393 && !integer_zerop (arg1)
7394 && TREE_CONSTANT (arg0)
7395 && TREE_CODE (arg0) == ADDR_EXPR
7397 t1 = build_int_2 (0, 0);
7399 /* Two real constants can be compared explicitly. */
7400 else if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
7402 /* If either operand is a NaN, the result is false with two
7403 exceptions: First, an NE_EXPR is true on NaNs, but that case
7404 is already handled correctly since we will be inverting the
7405 result for NE_EXPR. Second, if we had inverted a LE_EXPR
7406 or a GE_EXPR into a LT_EXPR, we must return true so that it
7407 will be inverted into false. */
7409 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
7410 || REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
7411 t1 = build_int_2 (invert && code == LT_EXPR, 0);
7413 else if (code == EQ_EXPR)
7414 t1 = build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (arg0),
7415 TREE_REAL_CST (arg1)),
7418 t1 = build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (arg0),
7419 TREE_REAL_CST (arg1)),
7423 if (t1 == NULL_TREE)
7427 TREE_INT_CST_LOW (t1) ^= 1;
7429 TREE_TYPE (t1) = type;
7430 if (TREE_CODE (type) == BOOLEAN_TYPE)
7431 return (*lang_hooks.truthvalue_conversion) (t1);
7435 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
7436 so all simple results must be passed through pedantic_non_lvalue. */
7437 if (TREE_CODE (arg0) == INTEGER_CST)
7438 return pedantic_non_lvalue
7439 (TREE_OPERAND (t, (integer_zerop (arg0) ? 2 : 1)));
7440 else if (operand_equal_p (arg1, TREE_OPERAND (expr, 2), 0))
7441 return pedantic_omit_one_operand (type, arg1, arg0);
7443 /* If the second operand is zero, invert the comparison and swap
7444 the second and third operands. Likewise if the second operand
7445 is constant and the third is not or if the third operand is
7446 equivalent to the first operand of the comparison. */
7448 if (integer_zerop (arg1)
7449 || (TREE_CONSTANT (arg1) && ! TREE_CONSTANT (TREE_OPERAND (t, 2)))
7450 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
7451 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
7452 TREE_OPERAND (t, 2),
7453 TREE_OPERAND (arg0, 1))))
7455 /* See if this can be inverted. If it can't, possibly because
7456 it was a floating-point inequality comparison, don't do
7458 tem = invert_truthvalue (arg0);
7460 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
7462 t = build (code, type, tem,
7463 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
7465 /* arg1 should be the first argument of the new T. */
7466 arg1 = TREE_OPERAND (t, 1);
7471 /* If we have A op B ? A : C, we may be able to convert this to a
7472 simpler expression, depending on the operation and the values
7473 of B and C. Signed zeros prevent all of these transformations,
7474 for reasons given above each one. */
7476 if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
7477 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
7478 arg1, TREE_OPERAND (arg0, 1))
7479 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
7481 tree arg2 = TREE_OPERAND (t, 2);
7482 enum tree_code comp_code = TREE_CODE (arg0);
7486 /* If we have A op 0 ? A : -A, consider applying the following
7489 A == 0? A : -A same as -A
7490 A != 0? A : -A same as A
7491 A >= 0? A : -A same as abs (A)
7492 A > 0? A : -A same as abs (A)
7493 A <= 0? A : -A same as -abs (A)
7494 A < 0? A : -A same as -abs (A)
7496 None of these transformations work for modes with signed
7497 zeros. If A is +/-0, the first two transformations will
7498 change the sign of the result (from +0 to -0, or vice
7499 versa). The last four will fix the sign of the result,
7500 even though the original expressions could be positive or
7501 negative, depending on the sign of A.
7503 Note that all these transformations are correct if A is
7504 NaN, since the two alternatives (A and -A) are also NaNs. */
7505 if ((FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 1)))
7506 ? real_zerop (TREE_OPERAND (arg0, 1))
7507 : integer_zerop (TREE_OPERAND (arg0, 1)))
7508 && TREE_CODE (arg2) == NEGATE_EXPR
7509 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
7517 (convert (TREE_TYPE (TREE_OPERAND (t, 1)),
7520 return pedantic_non_lvalue (convert (type, arg1));
7523 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
7524 arg1 = convert ((*lang_hooks.types.signed_type)
7525 (TREE_TYPE (arg1)), arg1);
7526 return pedantic_non_lvalue
7527 (convert (type, fold (build1 (ABS_EXPR,
7528 TREE_TYPE (arg1), arg1))));
7531 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
7532 arg1 = convert ((lang_hooks.types.signed_type)
7533 (TREE_TYPE (arg1)), arg1);
7534 return pedantic_non_lvalue
7535 (negate_expr (convert (type,
7536 fold (build1 (ABS_EXPR,
7543 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
7544 A == 0 ? A : 0 is always 0 unless A is -0. Note that
7545 both transformations are correct when A is NaN: A != 0
7546 is then true, and A == 0 is false. */
7548 if (integer_zerop (TREE_OPERAND (arg0, 1)) && integer_zerop (arg2))
7550 if (comp_code == NE_EXPR)
7551 return pedantic_non_lvalue (convert (type, arg1));
7552 else if (comp_code == EQ_EXPR)
7553 return pedantic_non_lvalue (convert (type, integer_zero_node));
7556 /* Try some transformations of A op B ? A : B.
7558 A == B? A : B same as B
7559 A != B? A : B same as A
7560 A >= B? A : B same as max (A, B)
7561 A > B? A : B same as max (B, A)
7562 A <= B? A : B same as min (A, B)
7563 A < B? A : B same as min (B, A)
7565 As above, these transformations don't work in the presence
7566 of signed zeros. For example, if A and B are zeros of
7567 opposite sign, the first two transformations will change
7568 the sign of the result. In the last four, the original
7569 expressions give different results for (A=+0, B=-0) and
7570 (A=-0, B=+0), but the transformed expressions do not.
7572 The first two transformations are correct if either A or B
7573 is a NaN. In the first transformation, the condition will
7574 be false, and B will indeed be chosen. In the case of the
7575 second transformation, the condition A != B will be true,
7576 and A will be chosen.
7578 The conversions to max() and min() are not correct if B is
7579 a number and A is not. The conditions in the original
7580 expressions will be false, so all four give B. The min()
7581 and max() versions would give a NaN instead. */
7582 if (operand_equal_for_comparison_p (TREE_OPERAND (arg0, 1),
7583 arg2, TREE_OPERAND (arg0, 0)))
7585 tree comp_op0 = TREE_OPERAND (arg0, 0);
7586 tree comp_op1 = TREE_OPERAND (arg0, 1);
7587 tree comp_type = TREE_TYPE (comp_op0);
7589 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
7590 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
7600 return pedantic_non_lvalue (convert (type, arg2));
7602 return pedantic_non_lvalue (convert (type, arg1));
7605 /* In C++ a ?: expression can be an lvalue, so put the
7606 operand which will be used if they are equal first
7607 so that we can convert this back to the
7608 corresponding COND_EXPR. */
7609 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
7610 return pedantic_non_lvalue
7611 (convert (type, fold (build (MIN_EXPR, comp_type,
7612 (comp_code == LE_EXPR
7613 ? comp_op0 : comp_op1),
7614 (comp_code == LE_EXPR
7615 ? comp_op1 : comp_op0)))));
7619 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
7620 return pedantic_non_lvalue
7621 (convert (type, fold (build (MAX_EXPR, comp_type,
7622 (comp_code == GE_EXPR
7623 ? comp_op0 : comp_op1),
7624 (comp_code == GE_EXPR
7625 ? comp_op1 : comp_op0)))));
7632 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
7633 we might still be able to simplify this. For example,
7634 if C1 is one less or one more than C2, this might have started
7635 out as a MIN or MAX and been transformed by this function.
7636 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
7638 if (INTEGRAL_TYPE_P (type)
7639 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7640 && TREE_CODE (arg2) == INTEGER_CST)
7644 /* We can replace A with C1 in this case. */
7645 arg1 = convert (type, TREE_OPERAND (arg0, 1));
7646 t = build (code, type, TREE_OPERAND (t, 0), arg1,
7647 TREE_OPERAND (t, 2));
7651 /* If C1 is C2 + 1, this is min(A, C2). */
7652 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
7653 && operand_equal_p (TREE_OPERAND (arg0, 1),
7654 const_binop (PLUS_EXPR, arg2,
7655 integer_one_node, 0), 1))
7656 return pedantic_non_lvalue
7657 (fold (build (MIN_EXPR, type, arg1, arg2)));
7661 /* If C1 is C2 - 1, this is min(A, C2). */
7662 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
7663 && operand_equal_p (TREE_OPERAND (arg0, 1),
7664 const_binop (MINUS_EXPR, arg2,
7665 integer_one_node, 0), 1))
7666 return pedantic_non_lvalue
7667 (fold (build (MIN_EXPR, type, arg1, arg2)));
7671 /* If C1 is C2 - 1, this is max(A, C2). */
7672 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
7673 && operand_equal_p (TREE_OPERAND (arg0, 1),
7674 const_binop (MINUS_EXPR, arg2,
7675 integer_one_node, 0), 1))
7676 return pedantic_non_lvalue
7677 (fold (build (MAX_EXPR, type, arg1, arg2)));
7681 /* If C1 is C2 + 1, this is max(A, C2). */
7682 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
7683 && operand_equal_p (TREE_OPERAND (arg0, 1),
7684 const_binop (PLUS_EXPR, arg2,
7685 integer_one_node, 0), 1))
7686 return pedantic_non_lvalue
7687 (fold (build (MAX_EXPR, type, arg1, arg2)));
7696 /* If the second operand is simpler than the third, swap them
7697 since that produces better jump optimization results. */
7698 if ((TREE_CONSTANT (arg1) || DECL_P (arg1)
7699 || TREE_CODE (arg1) == SAVE_EXPR)
7700 && ! (TREE_CONSTANT (TREE_OPERAND (t, 2))
7701 || DECL_P (TREE_OPERAND (t, 2))
7702 || TREE_CODE (TREE_OPERAND (t, 2)) == SAVE_EXPR))
7704 /* See if this can be inverted. If it can't, possibly because
7705 it was a floating-point inequality comparison, don't do
7707 tem = invert_truthvalue (arg0);
7709 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
7711 t = build (code, type, tem,
7712 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
7714 /* arg1 should be the first argument of the new T. */
7715 arg1 = TREE_OPERAND (t, 1);
7720 /* Convert A ? 1 : 0 to simply A. */
7721 if (integer_onep (TREE_OPERAND (t, 1))
7722 && integer_zerop (TREE_OPERAND (t, 2))
7723 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
7724 call to fold will try to move the conversion inside
7725 a COND, which will recurse. In that case, the COND_EXPR
7726 is probably the best choice, so leave it alone. */
7727 && type == TREE_TYPE (arg0))
7728 return pedantic_non_lvalue (arg0);
7730 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
7731 over COND_EXPR in cases such as floating point comparisons. */
7732 if (integer_zerop (TREE_OPERAND (t, 1))
7733 && integer_onep (TREE_OPERAND (t, 2))
7734 && truth_value_p (TREE_CODE (arg0)))
7735 return pedantic_non_lvalue (convert (type,
7736 invert_truthvalue (arg0)));
7738 /* Look for expressions of the form A & 2 ? 2 : 0. The result of this
7739 operation is simply A & 2. */
7741 if (integer_zerop (TREE_OPERAND (t, 2))
7742 && TREE_CODE (arg0) == NE_EXPR
7743 && integer_zerop (TREE_OPERAND (arg0, 1))
7744 && integer_pow2p (arg1)
7745 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
7746 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
7748 return pedantic_non_lvalue (convert (type, TREE_OPERAND (arg0, 0)));
7750 /* Convert A ? B : 0 into A && B if A and B are truth values. */
7751 if (integer_zerop (TREE_OPERAND (t, 2))
7752 && truth_value_p (TREE_CODE (arg0))
7753 && truth_value_p (TREE_CODE (arg1)))
7754 return pedantic_non_lvalue (fold (build (TRUTH_ANDIF_EXPR, type,
7757 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
7758 if (integer_onep (TREE_OPERAND (t, 2))
7759 && truth_value_p (TREE_CODE (arg0))
7760 && truth_value_p (TREE_CODE (arg1)))
7762 /* Only perform transformation if ARG0 is easily inverted. */
7763 tem = invert_truthvalue (arg0);
7764 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
7765 return pedantic_non_lvalue (fold (build (TRUTH_ORIF_EXPR, type,
7772 /* When pedantic, a compound expression can be neither an lvalue
7773 nor an integer constant expression. */
7774 if (TREE_SIDE_EFFECTS (arg0) || pedantic)
7776 /* Don't let (0, 0) be null pointer constant. */
7777 if (integer_zerop (arg1))
7778 return build1 (NOP_EXPR, type, arg1);
7779 return convert (type, arg1);
7783 return build_complex (type, arg0, arg1);
7787 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7789 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
7790 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
7791 TREE_OPERAND (arg0, 1));
7792 else if (TREE_CODE (arg0) == COMPLEX_CST)
7793 return TREE_REALPART (arg0);
7794 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7795 return fold (build (TREE_CODE (arg0), type,
7796 fold (build1 (REALPART_EXPR, type,
7797 TREE_OPERAND (arg0, 0))),
7798 fold (build1 (REALPART_EXPR,
7799 type, TREE_OPERAND (arg0, 1)))));
7803 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7804 return convert (type, integer_zero_node);
7805 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
7806 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
7807 TREE_OPERAND (arg0, 0));
7808 else if (TREE_CODE (arg0) == COMPLEX_CST)
7809 return TREE_IMAGPART (arg0);
7810 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7811 return fold (build (TREE_CODE (arg0), type,
7812 fold (build1 (IMAGPART_EXPR, type,
7813 TREE_OPERAND (arg0, 0))),
7814 fold (build1 (IMAGPART_EXPR, type,
7815 TREE_OPERAND (arg0, 1)))));
7818 /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
7820 case CLEANUP_POINT_EXPR:
7821 if (! has_cleanups (arg0))
7822 return TREE_OPERAND (t, 0);
7825 enum tree_code code0 = TREE_CODE (arg0);
7826 int kind0 = TREE_CODE_CLASS (code0);
7827 tree arg00 = TREE_OPERAND (arg0, 0);
7830 if (kind0 == '1' || code0 == TRUTH_NOT_EXPR)
7831 return fold (build1 (code0, type,
7832 fold (build1 (CLEANUP_POINT_EXPR,
7833 TREE_TYPE (arg00), arg00))));
7835 if (kind0 == '<' || kind0 == '2'
7836 || code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR
7837 || code0 == TRUTH_AND_EXPR || code0 == TRUTH_OR_EXPR
7838 || code0 == TRUTH_XOR_EXPR)
7840 arg01 = TREE_OPERAND (arg0, 1);
7842 if (TREE_CONSTANT (arg00)
7843 || ((code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR)
7844 && ! has_cleanups (arg00)))
7845 return fold (build (code0, type, arg00,
7846 fold (build1 (CLEANUP_POINT_EXPR,
7847 TREE_TYPE (arg01), arg01))));
7849 if (TREE_CONSTANT (arg01))
7850 return fold (build (code0, type,
7851 fold (build1 (CLEANUP_POINT_EXPR,
7852 TREE_TYPE (arg00), arg00)),
7860 /* Check for a built-in function. */
7861 if (TREE_CODE (TREE_OPERAND (expr, 0)) == ADDR_EXPR
7862 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (expr, 0), 0))
7864 && DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (expr, 0), 0)))
7866 tree tmp = fold_builtin (expr);
7874 } /* switch (code) */
7877 /* Determine if first argument is a multiple of second argument. Return 0 if
7878 it is not, or we cannot easily determined it to be.
7880 An example of the sort of thing we care about (at this point; this routine
7881 could surely be made more general, and expanded to do what the *_DIV_EXPR's
7882 fold cases do now) is discovering that
7884 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7890 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
7892 This code also handles discovering that
7894 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7896 is a multiple of 8 so we don't have to worry about dealing with a
7899 Note that we *look* inside a SAVE_EXPR only to determine how it was
7900 calculated; it is not safe for fold to do much of anything else with the
7901 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
7902 at run time. For example, the latter example above *cannot* be implemented
7903 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
7904 evaluation time of the original SAVE_EXPR is not necessarily the same at
7905 the time the new expression is evaluated. The only optimization of this
7906 sort that would be valid is changing
7908 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
7912 SAVE_EXPR (I) * SAVE_EXPR (J)
7914 (where the same SAVE_EXPR (J) is used in the original and the
7915 transformed version). */
7918 multiple_of_p (tree type, tree top, tree bottom)
7920 if (operand_equal_p (top, bottom, 0))
7923 if (TREE_CODE (type) != INTEGER_TYPE)
7926 switch (TREE_CODE (top))
7929 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
7930 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
7934 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
7935 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
7938 if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
7942 op1 = TREE_OPERAND (top, 1);
7943 /* const_binop may not detect overflow correctly,
7944 so check for it explicitly here. */
7945 if (TYPE_PRECISION (TREE_TYPE (size_one_node))
7946 > TREE_INT_CST_LOW (op1)
7947 && TREE_INT_CST_HIGH (op1) == 0
7948 && 0 != (t1 = convert (type,
7949 const_binop (LSHIFT_EXPR, size_one_node,
7951 && ! TREE_OVERFLOW (t1))
7952 return multiple_of_p (type, t1, bottom);
7957 /* Can't handle conversions from non-integral or wider integral type. */
7958 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
7959 || (TYPE_PRECISION (type)
7960 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
7963 /* .. fall through ... */
7966 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
7969 if (TREE_CODE (bottom) != INTEGER_CST
7970 || (TREE_UNSIGNED (type)
7971 && (tree_int_cst_sgn (top) < 0
7972 || tree_int_cst_sgn (bottom) < 0)))
7974 return integer_zerop (const_binop (TRUNC_MOD_EXPR,
7982 /* Return true if `t' is known to be non-negative. */
7985 tree_expr_nonnegative_p (tree t)
7987 switch (TREE_CODE (t))
7997 /* These are undefined at zero. This is true even if
7998 C[LT]Z_DEFINED_VALUE_AT_ZERO is set, since what we're
7999 computing here is a user-visible property. */
8003 return tree_int_cst_sgn (t) >= 0;
8006 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
8009 if (FLOAT_TYPE_P (TREE_TYPE (t)))
8010 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8011 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8013 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
8014 both unsigned and at least 2 bits shorter than the result. */
8015 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
8016 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
8017 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
8019 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
8020 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
8021 if (TREE_CODE (inner1) == INTEGER_TYPE && TREE_UNSIGNED (inner1)
8022 && TREE_CODE (inner2) == INTEGER_TYPE && TREE_UNSIGNED (inner2))
8024 unsigned int prec = MAX (TYPE_PRECISION (inner1),
8025 TYPE_PRECISION (inner2)) + 1;
8026 return prec < TYPE_PRECISION (TREE_TYPE (t));
8032 if (FLOAT_TYPE_P (TREE_TYPE (t)))
8034 /* x * x for floating point x is always non-negative. */
8035 if (operand_equal_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1), 0))
8037 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8038 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8041 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
8042 both unsigned and their total bits is shorter than the result. */
8043 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
8044 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
8045 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
8047 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
8048 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
8049 if (TREE_CODE (inner1) == INTEGER_TYPE && TREE_UNSIGNED (inner1)
8050 && TREE_CODE (inner2) == INTEGER_TYPE && TREE_UNSIGNED (inner2))
8051 return TYPE_PRECISION (inner1) + TYPE_PRECISION (inner2)
8052 < TYPE_PRECISION (TREE_TYPE (t));
8056 case TRUNC_DIV_EXPR:
8058 case FLOOR_DIV_EXPR:
8059 case ROUND_DIV_EXPR:
8060 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8061 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8063 case TRUNC_MOD_EXPR:
8065 case FLOOR_MOD_EXPR:
8066 case ROUND_MOD_EXPR:
8067 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8070 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8071 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8075 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
8076 tree outer_type = TREE_TYPE (t);
8078 if (TREE_CODE (outer_type) == REAL_TYPE)
8080 if (TREE_CODE (inner_type) == REAL_TYPE)
8081 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8082 if (TREE_CODE (inner_type) == INTEGER_TYPE)
8084 if (TREE_UNSIGNED (inner_type))
8086 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8089 else if (TREE_CODE (outer_type) == INTEGER_TYPE)
8091 if (TREE_CODE (inner_type) == REAL_TYPE)
8092 return tree_expr_nonnegative_p (TREE_OPERAND (t,0));
8093 if (TREE_CODE (inner_type) == INTEGER_TYPE)
8094 return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
8095 && TREE_UNSIGNED (inner_type);
8101 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
8102 && tree_expr_nonnegative_p (TREE_OPERAND (t, 2));
8104 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8106 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8107 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8109 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8110 || tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8112 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8114 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8116 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8117 case NON_LVALUE_EXPR:
8118 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8120 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8122 return rtl_expr_nonnegative_p (RTL_EXPR_RTL (t));
8125 if (TREE_CODE (TREE_OPERAND (t, 0)) == ADDR_EXPR)
8127 tree fndecl = TREE_OPERAND (TREE_OPERAND (t, 0), 0);
8128 tree arglist = TREE_OPERAND (t, 1);
8129 if (TREE_CODE (fndecl) == FUNCTION_DECL
8130 && DECL_BUILT_IN (fndecl)
8131 && DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_MD)
8132 switch (DECL_FUNCTION_CODE (fndecl))
8135 case BUILT_IN_CABSL:
8136 case BUILT_IN_CABSF:
8141 case BUILT_IN_FABSF:
8142 case BUILT_IN_FABSL:
8144 case BUILT_IN_SQRTF:
8145 case BUILT_IN_SQRTL:
8149 case BUILT_IN_ATANF:
8150 case BUILT_IN_ATANL:
8152 case BUILT_IN_CEILF:
8153 case BUILT_IN_CEILL:
8154 case BUILT_IN_FLOOR:
8155 case BUILT_IN_FLOORF:
8156 case BUILT_IN_FLOORL:
8157 case BUILT_IN_NEARBYINT:
8158 case BUILT_IN_NEARBYINTF:
8159 case BUILT_IN_NEARBYINTL:
8160 case BUILT_IN_ROUND:
8161 case BUILT_IN_ROUNDF:
8162 case BUILT_IN_ROUNDL:
8163 case BUILT_IN_TRUNC:
8164 case BUILT_IN_TRUNCF:
8165 case BUILT_IN_TRUNCL:
8166 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
8171 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
8178 /* ... fall through ... */
8181 if (truth_value_p (TREE_CODE (t)))
8182 /* Truth values evaluate to 0 or 1, which is nonnegative. */
8186 /* We don't know sign of `t', so be conservative and return false. */
8190 /* Return true if `r' is known to be non-negative.
8191 Only handles constants at the moment. */
8194 rtl_expr_nonnegative_p (rtx r)
8196 switch (GET_CODE (r))
8199 return INTVAL (r) >= 0;
8202 if (GET_MODE (r) == VOIDmode)
8203 return CONST_DOUBLE_HIGH (r) >= 0;
8211 units = CONST_VECTOR_NUNITS (r);
8213 for (i = 0; i < units; ++i)
8215 elt = CONST_VECTOR_ELT (r, i);
8216 if (!rtl_expr_nonnegative_p (elt))
8225 /* These are always nonnegative. */
8233 #include "gt-fold-const.h"