1 /* Fold a constant sub-tree into a single node for C-compiler
2 Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
3 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
22 /*@@ This file should be rewritten to use an arbitrary precision
23 @@ representation for "struct tree_int_cst" and "struct tree_real_cst".
24 @@ Perhaps the routines could also be used for bc/dc, and made a lib.
25 @@ The routines that translate from the ap rep should
26 @@ warn if precision et. al. is lost.
27 @@ This would also make life easier when this technology is used
28 @@ for cross-compilers. */
30 /* The entry points in this file are fold, size_int_wide, size_binop
33 fold takes a tree as argument and returns a simplified tree.
35 size_binop takes a tree code for an arithmetic operation
36 and two operands that are trees, and produces a tree for the
37 result, assuming the type comes from `sizetype'.
39 size_int takes an integer value, and creates a tree constant
40 with type from `sizetype'.
42 force_fit_type takes a constant and prior overflow indicator, and
43 forces the value to fit the type. It returns an overflow indicator. */
47 #include "coretypes.h"
58 #include "langhooks.h"
61 static void encode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT, HOST_WIDE_INT);
62 static void decode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
63 static bool negate_mathfn_p (enum built_in_function);
64 static bool negate_expr_p (tree);
65 static tree negate_expr (tree);
66 static tree split_tree (tree, enum tree_code, tree *, tree *, tree *, int);
67 static tree associate_trees (tree, tree, enum tree_code, tree);
68 static tree int_const_binop (enum tree_code, tree, tree, int);
69 static tree const_binop (enum tree_code, tree, tree, int);
70 static hashval_t size_htab_hash (const void *);
71 static int size_htab_eq (const void *, const void *);
72 static tree fold_convert_const (enum tree_code, tree, tree);
73 static tree fold_convert (tree, tree);
74 static enum tree_code invert_tree_comparison (enum tree_code);
75 static enum tree_code swap_tree_comparison (enum tree_code);
76 static int comparison_to_compcode (enum tree_code);
77 static enum tree_code compcode_to_comparison (int);
78 static int truth_value_p (enum tree_code);
79 static int operand_equal_for_comparison_p (tree, tree, tree);
80 static int twoval_comparison_p (tree, tree *, tree *, int *);
81 static tree eval_subst (tree, tree, tree, tree, tree);
82 static tree pedantic_omit_one_operand (tree, tree, tree);
83 static tree distribute_bit_expr (enum tree_code, tree, tree, tree);
84 static tree make_bit_field_ref (tree, tree, int, int, int);
85 static tree optimize_bit_field_compare (enum tree_code, tree, tree, tree);
86 static tree decode_field_reference (tree, HOST_WIDE_INT *, HOST_WIDE_INT *,
87 enum machine_mode *, int *, int *,
89 static int all_ones_mask_p (tree, int);
90 static tree sign_bit_p (tree, tree);
91 static int simple_operand_p (tree);
92 static tree range_binop (enum tree_code, tree, tree, int, tree, int);
93 static tree make_range (tree, int *, tree *, tree *);
94 static tree build_range_check (tree, tree, int, tree, tree);
95 static int merge_ranges (int *, tree *, tree *, int, tree, tree, int, tree,
97 static tree fold_range_test (tree);
98 static tree unextend (tree, int, int, tree);
99 static tree fold_truthop (enum tree_code, tree, tree, tree);
100 static tree optimize_minmax_comparison (tree);
101 static tree extract_muldiv (tree, tree, enum tree_code, tree);
102 static tree extract_muldiv_1 (tree, tree, enum tree_code, tree);
103 static tree strip_compound_expr (tree, tree);
104 static int multiple_of_p (tree, tree, tree);
105 static tree constant_boolean_node (int, tree);
106 static int count_cond (tree, int);
107 static tree fold_binary_op_with_conditional_arg (enum tree_code, tree, tree,
109 static bool fold_real_zero_addition_p (tree, tree, int);
110 static tree fold_mathfn_compare (enum built_in_function, enum tree_code,
112 static tree fold_inf_compare (enum tree_code, tree, tree, tree);
113 static bool reorder_operands_p (tree, tree);
114 static bool tree_swap_operands_p (tree, tree, bool);
116 static tree fold_negate_const (tree, tree);
117 static tree fold_abs_const (tree, tree);
118 static tree fold_relational_const (enum tree_code, tree, tree, tree);
120 /* The following constants represent a bit based encoding of GCC's
121 comparison operators. This encoding simplifies transformations
122 on relational comparison operators, such as AND and OR. */
123 #define COMPCODE_FALSE 0
124 #define COMPCODE_LT 1
125 #define COMPCODE_EQ 2
126 #define COMPCODE_LE 3
127 #define COMPCODE_GT 4
128 #define COMPCODE_NE 5
129 #define COMPCODE_GE 6
130 #define COMPCODE_TRUE 7
132 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
133 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
134 and SUM1. Then this yields nonzero if overflow occurred during the
137 Overflow occurs if A and B have the same sign, but A and SUM differ in
138 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
140 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
142 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
143 We do that by representing the two-word integer in 4 words, with only
144 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
145 number. The value of the word is LOWPART + HIGHPART * BASE. */
148 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
149 #define HIGHPART(x) \
150 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
151 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
153 /* Unpack a two-word integer into 4 words.
154 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
155 WORDS points to the array of HOST_WIDE_INTs. */
158 encode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT low, HOST_WIDE_INT hi)
160 words[0] = LOWPART (low);
161 words[1] = HIGHPART (low);
162 words[2] = LOWPART (hi);
163 words[3] = HIGHPART (hi);
166 /* Pack an array of 4 words into a two-word integer.
167 WORDS points to the array of words.
168 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
171 decode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT *low,
174 *low = words[0] + words[1] * BASE;
175 *hi = words[2] + words[3] * BASE;
178 /* Make the integer constant T valid for its type by setting to 0 or 1 all
179 the bits in the constant that don't belong in the type.
181 Return 1 if a signed overflow occurs, 0 otherwise. If OVERFLOW is
182 nonzero, a signed overflow has already occurred in calculating T, so
186 force_fit_type (tree t, int overflow)
188 unsigned HOST_WIDE_INT low;
192 if (TREE_CODE (t) == REAL_CST)
194 /* ??? Used to check for overflow here via CHECK_FLOAT_TYPE.
195 Consider doing it via real_convert now. */
199 else if (TREE_CODE (t) != INTEGER_CST)
202 low = TREE_INT_CST_LOW (t);
203 high = TREE_INT_CST_HIGH (t);
205 if (POINTER_TYPE_P (TREE_TYPE (t))
206 || TREE_CODE (TREE_TYPE (t)) == OFFSET_TYPE)
209 prec = TYPE_PRECISION (TREE_TYPE (t));
211 /* First clear all bits that are beyond the type's precision. */
213 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
215 else if (prec > HOST_BITS_PER_WIDE_INT)
216 TREE_INT_CST_HIGH (t)
217 &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
220 TREE_INT_CST_HIGH (t) = 0;
221 if (prec < HOST_BITS_PER_WIDE_INT)
222 TREE_INT_CST_LOW (t) &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
225 /* Unsigned types do not suffer sign extension or overflow unless they
227 if (TREE_UNSIGNED (TREE_TYPE (t))
228 && ! (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
229 && TYPE_IS_SIZETYPE (TREE_TYPE (t))))
232 /* If the value's sign bit is set, extend the sign. */
233 if (prec != 2 * HOST_BITS_PER_WIDE_INT
234 && (prec > HOST_BITS_PER_WIDE_INT
235 ? 0 != (TREE_INT_CST_HIGH (t)
237 << (prec - HOST_BITS_PER_WIDE_INT - 1)))
238 : 0 != (TREE_INT_CST_LOW (t)
239 & ((unsigned HOST_WIDE_INT) 1 << (prec - 1)))))
241 /* Value is negative:
242 set to 1 all the bits that are outside this type's precision. */
243 if (prec > HOST_BITS_PER_WIDE_INT)
244 TREE_INT_CST_HIGH (t)
245 |= ((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
248 TREE_INT_CST_HIGH (t) = -1;
249 if (prec < HOST_BITS_PER_WIDE_INT)
250 TREE_INT_CST_LOW (t) |= ((unsigned HOST_WIDE_INT) (-1) << prec);
254 /* Return nonzero if signed overflow occurred. */
256 ((overflow | (low ^ TREE_INT_CST_LOW (t)) | (high ^ TREE_INT_CST_HIGH (t)))
260 /* Add two doubleword integers with doubleword result.
261 Each argument is given as two `HOST_WIDE_INT' pieces.
262 One argument is L1 and H1; the other, L2 and H2.
263 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
266 add_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
267 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
268 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
270 unsigned HOST_WIDE_INT l;
274 h = h1 + h2 + (l < l1);
278 return OVERFLOW_SUM_SIGN (h1, h2, h);
281 /* Negate a doubleword integer with doubleword result.
282 Return nonzero if the operation overflows, assuming it's signed.
283 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
284 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
287 neg_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
288 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
294 return (*hv & h1) < 0;
304 /* Multiply two doubleword integers with doubleword result.
305 Return nonzero if the operation overflows, assuming it's signed.
306 Each argument is given as two `HOST_WIDE_INT' pieces.
307 One argument is L1 and H1; the other, L2 and H2.
308 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
311 mul_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
312 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
313 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
315 HOST_WIDE_INT arg1[4];
316 HOST_WIDE_INT arg2[4];
317 HOST_WIDE_INT prod[4 * 2];
318 unsigned HOST_WIDE_INT carry;
320 unsigned HOST_WIDE_INT toplow, neglow;
321 HOST_WIDE_INT tophigh, neghigh;
323 encode (arg1, l1, h1);
324 encode (arg2, l2, h2);
326 memset (prod, 0, sizeof prod);
328 for (i = 0; i < 4; i++)
331 for (j = 0; j < 4; j++)
334 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
335 carry += arg1[i] * arg2[j];
336 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
338 prod[k] = LOWPART (carry);
339 carry = HIGHPART (carry);
344 decode (prod, lv, hv); /* This ignores prod[4] through prod[4*2-1] */
346 /* Check for overflow by calculating the top half of the answer in full;
347 it should agree with the low half's sign bit. */
348 decode (prod + 4, &toplow, &tophigh);
351 neg_double (l2, h2, &neglow, &neghigh);
352 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
356 neg_double (l1, h1, &neglow, &neghigh);
357 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
359 return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
362 /* Shift the doubleword integer in L1, H1 left by COUNT places
363 keeping only PREC bits of result.
364 Shift right if COUNT is negative.
365 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
366 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
369 lshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
370 HOST_WIDE_INT count, unsigned int prec,
371 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv, int arith)
373 unsigned HOST_WIDE_INT signmask;
377 rshift_double (l1, h1, -count, prec, lv, hv, arith);
381 if (SHIFT_COUNT_TRUNCATED)
384 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
386 /* Shifting by the host word size is undefined according to the
387 ANSI standard, so we must handle this as a special case. */
391 else if (count >= HOST_BITS_PER_WIDE_INT)
393 *hv = l1 << (count - HOST_BITS_PER_WIDE_INT);
398 *hv = (((unsigned HOST_WIDE_INT) h1 << count)
399 | (l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
403 /* Sign extend all bits that are beyond the precision. */
405 signmask = -((prec > HOST_BITS_PER_WIDE_INT
406 ? ((unsigned HOST_WIDE_INT) *hv
407 >> (prec - HOST_BITS_PER_WIDE_INT - 1))
408 : (*lv >> (prec - 1))) & 1);
410 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
412 else if (prec >= HOST_BITS_PER_WIDE_INT)
414 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
415 *hv |= signmask << (prec - HOST_BITS_PER_WIDE_INT);
420 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
421 *lv |= signmask << prec;
425 /* Shift the doubleword integer in L1, H1 right by COUNT places
426 keeping only PREC bits of result. COUNT must be positive.
427 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
428 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
431 rshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
432 HOST_WIDE_INT count, unsigned int prec,
433 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
436 unsigned HOST_WIDE_INT signmask;
439 ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
442 if (SHIFT_COUNT_TRUNCATED)
445 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
447 /* Shifting by the host word size is undefined according to the
448 ANSI standard, so we must handle this as a special case. */
452 else if (count >= HOST_BITS_PER_WIDE_INT)
455 *lv = (unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT);
459 *hv = (unsigned HOST_WIDE_INT) h1 >> count;
461 | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
464 /* Zero / sign extend all bits that are beyond the precision. */
466 if (count >= (HOST_WIDE_INT)prec)
471 else if ((prec - count) >= 2 * HOST_BITS_PER_WIDE_INT)
473 else if ((prec - count) >= HOST_BITS_PER_WIDE_INT)
475 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - count - HOST_BITS_PER_WIDE_INT));
476 *hv |= signmask << (prec - count - HOST_BITS_PER_WIDE_INT);
481 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << (prec - count));
482 *lv |= signmask << (prec - count);
486 /* Rotate the doubleword integer in L1, H1 left by COUNT places
487 keeping only PREC bits of result.
488 Rotate right if COUNT is negative.
489 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
492 lrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
493 HOST_WIDE_INT count, unsigned int prec,
494 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
496 unsigned HOST_WIDE_INT s1l, s2l;
497 HOST_WIDE_INT s1h, s2h;
503 lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
504 rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
509 /* Rotate the doubleword integer in L1, H1 left by COUNT places
510 keeping only PREC bits of result. COUNT must be positive.
511 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
514 rrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
515 HOST_WIDE_INT count, unsigned int prec,
516 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
518 unsigned HOST_WIDE_INT s1l, s2l;
519 HOST_WIDE_INT s1h, s2h;
525 rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
526 lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
531 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
532 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
533 CODE is a tree code for a kind of division, one of
534 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
536 It controls how the quotient is rounded to an integer.
537 Return nonzero if the operation overflows.
538 UNS nonzero says do unsigned division. */
541 div_and_round_double (enum tree_code code, int uns,
542 unsigned HOST_WIDE_INT lnum_orig, /* num == numerator == dividend */
543 HOST_WIDE_INT hnum_orig,
544 unsigned HOST_WIDE_INT lden_orig, /* den == denominator == divisor */
545 HOST_WIDE_INT hden_orig,
546 unsigned HOST_WIDE_INT *lquo,
547 HOST_WIDE_INT *hquo, unsigned HOST_WIDE_INT *lrem,
551 HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
552 HOST_WIDE_INT den[4], quo[4];
554 unsigned HOST_WIDE_INT work;
555 unsigned HOST_WIDE_INT carry = 0;
556 unsigned HOST_WIDE_INT lnum = lnum_orig;
557 HOST_WIDE_INT hnum = hnum_orig;
558 unsigned HOST_WIDE_INT lden = lden_orig;
559 HOST_WIDE_INT hden = hden_orig;
562 if (hden == 0 && lden == 0)
563 overflow = 1, lden = 1;
565 /* Calculate quotient sign and convert operands to unsigned. */
571 /* (minimum integer) / (-1) is the only overflow case. */
572 if (neg_double (lnum, hnum, &lnum, &hnum)
573 && ((HOST_WIDE_INT) lden & hden) == -1)
579 neg_double (lden, hden, &lden, &hden);
583 if (hnum == 0 && hden == 0)
584 { /* single precision */
586 /* This unsigned division rounds toward zero. */
592 { /* trivial case: dividend < divisor */
593 /* hden != 0 already checked. */
600 memset (quo, 0, sizeof quo);
602 memset (num, 0, sizeof num); /* to zero 9th element */
603 memset (den, 0, sizeof den);
605 encode (num, lnum, hnum);
606 encode (den, lden, hden);
608 /* Special code for when the divisor < BASE. */
609 if (hden == 0 && lden < (unsigned HOST_WIDE_INT) BASE)
611 /* hnum != 0 already checked. */
612 for (i = 4 - 1; i >= 0; i--)
614 work = num[i] + carry * BASE;
615 quo[i] = work / lden;
621 /* Full double precision division,
622 with thanks to Don Knuth's "Seminumerical Algorithms". */
623 int num_hi_sig, den_hi_sig;
624 unsigned HOST_WIDE_INT quo_est, scale;
626 /* Find the highest nonzero divisor digit. */
627 for (i = 4 - 1;; i--)
634 /* Insure that the first digit of the divisor is at least BASE/2.
635 This is required by the quotient digit estimation algorithm. */
637 scale = BASE / (den[den_hi_sig] + 1);
639 { /* scale divisor and dividend */
641 for (i = 0; i <= 4 - 1; i++)
643 work = (num[i] * scale) + carry;
644 num[i] = LOWPART (work);
645 carry = HIGHPART (work);
650 for (i = 0; i <= 4 - 1; i++)
652 work = (den[i] * scale) + carry;
653 den[i] = LOWPART (work);
654 carry = HIGHPART (work);
655 if (den[i] != 0) den_hi_sig = i;
662 for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--)
664 /* Guess the next quotient digit, quo_est, by dividing the first
665 two remaining dividend digits by the high order quotient digit.
666 quo_est is never low and is at most 2 high. */
667 unsigned HOST_WIDE_INT tmp;
669 num_hi_sig = i + den_hi_sig + 1;
670 work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
671 if (num[num_hi_sig] != den[den_hi_sig])
672 quo_est = work / den[den_hi_sig];
676 /* Refine quo_est so it's usually correct, and at most one high. */
677 tmp = work - quo_est * den[den_hi_sig];
679 && (den[den_hi_sig - 1] * quo_est
680 > (tmp * BASE + num[num_hi_sig - 2])))
683 /* Try QUO_EST as the quotient digit, by multiplying the
684 divisor by QUO_EST and subtracting from the remaining dividend.
685 Keep in mind that QUO_EST is the I - 1st digit. */
688 for (j = 0; j <= den_hi_sig; j++)
690 work = quo_est * den[j] + carry;
691 carry = HIGHPART (work);
692 work = num[i + j] - LOWPART (work);
693 num[i + j] = LOWPART (work);
694 carry += HIGHPART (work) != 0;
697 /* If quo_est was high by one, then num[i] went negative and
698 we need to correct things. */
699 if (num[num_hi_sig] < (HOST_WIDE_INT) carry)
702 carry = 0; /* add divisor back in */
703 for (j = 0; j <= den_hi_sig; j++)
705 work = num[i + j] + den[j] + carry;
706 carry = HIGHPART (work);
707 num[i + j] = LOWPART (work);
710 num [num_hi_sig] += carry;
713 /* Store the quotient digit. */
718 decode (quo, lquo, hquo);
721 /* If result is negative, make it so. */
723 neg_double (*lquo, *hquo, lquo, hquo);
725 /* Compute trial remainder: rem = num - (quo * den) */
726 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
727 neg_double (*lrem, *hrem, lrem, hrem);
728 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
733 case TRUNC_MOD_EXPR: /* round toward zero */
734 case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
738 case FLOOR_MOD_EXPR: /* round toward negative infinity */
739 if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
742 add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
750 case CEIL_MOD_EXPR: /* round toward positive infinity */
751 if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
753 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
761 case ROUND_MOD_EXPR: /* round to closest integer */
763 unsigned HOST_WIDE_INT labs_rem = *lrem;
764 HOST_WIDE_INT habs_rem = *hrem;
765 unsigned HOST_WIDE_INT labs_den = lden, ltwice;
766 HOST_WIDE_INT habs_den = hden, htwice;
768 /* Get absolute values. */
770 neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
772 neg_double (lden, hden, &labs_den, &habs_den);
774 /* If (2 * abs (lrem) >= abs (lden)) */
775 mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
776 labs_rem, habs_rem, <wice, &htwice);
778 if (((unsigned HOST_WIDE_INT) habs_den
779 < (unsigned HOST_WIDE_INT) htwice)
780 || (((unsigned HOST_WIDE_INT) habs_den
781 == (unsigned HOST_WIDE_INT) htwice)
782 && (labs_den < ltwice)))
786 add_double (*lquo, *hquo,
787 (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
790 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
802 /* Compute true remainder: rem = num - (quo * den) */
803 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
804 neg_double (*lrem, *hrem, lrem, hrem);
805 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
809 /* Return true if built-in mathematical function specified by CODE
810 preserves the sign of it argument, i.e. -f(x) == f(-x). */
813 negate_mathfn_p (enum built_in_function code)
837 /* Determine whether an expression T can be cheaply negated using
838 the function negate_expr. */
841 negate_expr_p (tree t)
843 unsigned HOST_WIDE_INT val;
850 type = TREE_TYPE (t);
853 switch (TREE_CODE (t))
856 if (TREE_UNSIGNED (type) || ! flag_trapv)
859 /* Check that -CST will not overflow type. */
860 prec = TYPE_PRECISION (type);
861 if (prec > HOST_BITS_PER_WIDE_INT)
863 if (TREE_INT_CST_LOW (t) != 0)
865 prec -= HOST_BITS_PER_WIDE_INT;
866 val = TREE_INT_CST_HIGH (t);
869 val = TREE_INT_CST_LOW (t);
870 if (prec < HOST_BITS_PER_WIDE_INT)
871 val &= ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
872 return val != ((unsigned HOST_WIDE_INT) 1 << (prec - 1));
879 return negate_expr_p (TREE_REALPART (t))
880 && negate_expr_p (TREE_IMAGPART (t));
883 if (FLOAT_TYPE_P (type) && !flag_unsafe_math_optimizations)
885 /* -(A + B) -> (-B) - A. */
886 if (negate_expr_p (TREE_OPERAND (t, 1))
887 && reorder_operands_p (TREE_OPERAND (t, 0),
888 TREE_OPERAND (t, 1)))
890 /* -(A + B) -> (-A) - B. */
891 return negate_expr_p (TREE_OPERAND (t, 0));
894 /* We can't turn -(A-B) into B-A when we honor signed zeros. */
895 return (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
896 && reorder_operands_p (TREE_OPERAND (t, 0),
897 TREE_OPERAND (t, 1));
900 if (TREE_UNSIGNED (TREE_TYPE (t)))
906 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
907 return negate_expr_p (TREE_OPERAND (t, 1))
908 || negate_expr_p (TREE_OPERAND (t, 0));
912 /* Negate -((double)float) as (double)(-float). */
913 if (TREE_CODE (type) == REAL_TYPE)
915 tree tem = strip_float_extensions (t);
917 return negate_expr_p (tem);
922 /* Negate -f(x) as f(-x). */
923 if (negate_mathfn_p (builtin_mathfn_code (t)))
924 return negate_expr_p (TREE_VALUE (TREE_OPERAND (t, 1)));
928 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
929 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
931 tree op1 = TREE_OPERAND (t, 1);
932 if (TREE_INT_CST_HIGH (op1) == 0
933 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
934 == TREE_INT_CST_LOW (op1))
945 /* Given T, an expression, return the negation of T. Allow for T to be
946 null, in which case return null. */
957 type = TREE_TYPE (t);
960 switch (TREE_CODE (t))
963 tem = fold_negate_const (t, type);
964 if (! TREE_OVERFLOW (tem)
965 || TREE_UNSIGNED (type)
971 tem = fold_negate_const (t, type);
972 /* Two's complement FP formats, such as c4x, may overflow. */
973 if (! TREE_OVERFLOW (tem) || ! flag_trapping_math)
974 return fold_convert (type, tem);
979 tree rpart = negate_expr (TREE_REALPART (t));
980 tree ipart = negate_expr (TREE_IMAGPART (t));
982 if ((TREE_CODE (rpart) == REAL_CST
983 && TREE_CODE (ipart) == REAL_CST)
984 || (TREE_CODE (rpart) == INTEGER_CST
985 && TREE_CODE (ipart) == INTEGER_CST))
986 return build_complex (type, rpart, ipart);
991 return fold_convert (type, TREE_OPERAND (t, 0));
994 if (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
996 /* -(A + B) -> (-B) - A. */
997 if (negate_expr_p (TREE_OPERAND (t, 1))
998 && reorder_operands_p (TREE_OPERAND (t, 0),
999 TREE_OPERAND (t, 1)))
1000 return fold_convert (type,
1001 fold (build (MINUS_EXPR, TREE_TYPE (t),
1002 negate_expr (TREE_OPERAND (t, 1)),
1003 TREE_OPERAND (t, 0))));
1004 /* -(A + B) -> (-A) - B. */
1005 if (negate_expr_p (TREE_OPERAND (t, 0)))
1006 return fold_convert (type,
1007 fold (build (MINUS_EXPR, TREE_TYPE (t),
1008 negate_expr (TREE_OPERAND (t, 0)),
1009 TREE_OPERAND (t, 1))));
1014 /* - (A - B) -> B - A */
1015 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
1016 && reorder_operands_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1)))
1017 return fold_convert (type,
1018 fold (build (MINUS_EXPR, TREE_TYPE (t),
1019 TREE_OPERAND (t, 1),
1020 TREE_OPERAND (t, 0))));
1024 if (TREE_UNSIGNED (TREE_TYPE (t)))
1030 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
1032 tem = TREE_OPERAND (t, 1);
1033 if (negate_expr_p (tem))
1034 return fold_convert (type,
1035 fold (build (TREE_CODE (t), TREE_TYPE (t),
1036 TREE_OPERAND (t, 0),
1037 negate_expr (tem))));
1038 tem = TREE_OPERAND (t, 0);
1039 if (negate_expr_p (tem))
1040 return fold_convert (type,
1041 fold (build (TREE_CODE (t), TREE_TYPE (t),
1043 TREE_OPERAND (t, 1))));
1048 /* Convert -((double)float) into (double)(-float). */
1049 if (TREE_CODE (type) == REAL_TYPE)
1051 tem = strip_float_extensions (t);
1052 if (tem != t && negate_expr_p (tem))
1053 return fold_convert (type, negate_expr (tem));
1058 /* Negate -f(x) as f(-x). */
1059 if (negate_mathfn_p (builtin_mathfn_code (t))
1060 && negate_expr_p (TREE_VALUE (TREE_OPERAND (t, 1))))
1062 tree fndecl, arg, arglist;
1064 fndecl = get_callee_fndecl (t);
1065 arg = negate_expr (TREE_VALUE (TREE_OPERAND (t, 1)));
1066 arglist = build_tree_list (NULL_TREE, arg);
1067 return build_function_call_expr (fndecl, arglist);
1072 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1073 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
1075 tree op1 = TREE_OPERAND (t, 1);
1076 if (TREE_INT_CST_HIGH (op1) == 0
1077 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
1078 == TREE_INT_CST_LOW (op1))
1080 tree ntype = TREE_UNSIGNED (type)
1081 ? lang_hooks.types.signed_type (type)
1082 : lang_hooks.types.unsigned_type (type);
1083 tree temp = fold_convert (ntype, TREE_OPERAND (t, 0));
1084 temp = fold (build2 (RSHIFT_EXPR, ntype, temp, op1));
1085 return fold_convert (type, temp);
1094 tem = fold (build1 (NEGATE_EXPR, TREE_TYPE (t), t));
1095 return fold_convert (type, tem);
1098 /* Split a tree IN into a constant, literal and variable parts that could be
1099 combined with CODE to make IN. "constant" means an expression with
1100 TREE_CONSTANT but that isn't an actual constant. CODE must be a
1101 commutative arithmetic operation. Store the constant part into *CONP,
1102 the literal in *LITP and return the variable part. If a part isn't
1103 present, set it to null. If the tree does not decompose in this way,
1104 return the entire tree as the variable part and the other parts as null.
1106 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
1107 case, we negate an operand that was subtracted. Except if it is a
1108 literal for which we use *MINUS_LITP instead.
1110 If NEGATE_P is true, we are negating all of IN, again except a literal
1111 for which we use *MINUS_LITP instead.
1113 If IN is itself a literal or constant, return it as appropriate.
1115 Note that we do not guarantee that any of the three values will be the
1116 same type as IN, but they will have the same signedness and mode. */
1119 split_tree (tree in, enum tree_code code, tree *conp, tree *litp,
1120 tree *minus_litp, int negate_p)
1128 /* Strip any conversions that don't change the machine mode or signedness. */
1129 STRIP_SIGN_NOPS (in);
1131 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST)
1133 else if (TREE_CODE (in) == code
1134 || (! FLOAT_TYPE_P (TREE_TYPE (in))
1135 /* We can associate addition and subtraction together (even
1136 though the C standard doesn't say so) for integers because
1137 the value is not affected. For reals, the value might be
1138 affected, so we can't. */
1139 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
1140 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
1142 tree op0 = TREE_OPERAND (in, 0);
1143 tree op1 = TREE_OPERAND (in, 1);
1144 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
1145 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
1147 /* First see if either of the operands is a literal, then a constant. */
1148 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
1149 *litp = op0, op0 = 0;
1150 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST)
1151 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
1153 if (op0 != 0 && TREE_CONSTANT (op0))
1154 *conp = op0, op0 = 0;
1155 else if (op1 != 0 && TREE_CONSTANT (op1))
1156 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
1158 /* If we haven't dealt with either operand, this is not a case we can
1159 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1160 if (op0 != 0 && op1 != 0)
1165 var = op1, neg_var_p = neg1_p;
1167 /* Now do any needed negations. */
1169 *minus_litp = *litp, *litp = 0;
1171 *conp = negate_expr (*conp);
1173 var = negate_expr (var);
1175 else if (TREE_CONSTANT (in))
1183 *minus_litp = *litp, *litp = 0;
1184 else if (*minus_litp)
1185 *litp = *minus_litp, *minus_litp = 0;
1186 *conp = negate_expr (*conp);
1187 var = negate_expr (var);
1193 /* Re-associate trees split by the above function. T1 and T2 are either
1194 expressions to associate or null. Return the new expression, if any. If
1195 we build an operation, do it in TYPE and with CODE. */
1198 associate_trees (tree t1, tree t2, enum tree_code code, tree type)
1205 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1206 try to fold this since we will have infinite recursion. But do
1207 deal with any NEGATE_EXPRs. */
1208 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
1209 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1211 if (code == PLUS_EXPR)
1213 if (TREE_CODE (t1) == NEGATE_EXPR)
1214 return build (MINUS_EXPR, type, fold_convert (type, t2),
1215 fold_convert (type, TREE_OPERAND (t1, 0)));
1216 else if (TREE_CODE (t2) == NEGATE_EXPR)
1217 return build (MINUS_EXPR, type, fold_convert (type, t1),
1218 fold_convert (type, TREE_OPERAND (t2, 0)));
1220 return build (code, type, fold_convert (type, t1),
1221 fold_convert (type, t2));
1224 return fold (build (code, type, fold_convert (type, t1),
1225 fold_convert (type, t2)));
1228 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1229 to produce a new constant.
1231 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1234 int_const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1236 unsigned HOST_WIDE_INT int1l, int2l;
1237 HOST_WIDE_INT int1h, int2h;
1238 unsigned HOST_WIDE_INT low;
1240 unsigned HOST_WIDE_INT garbagel;
1241 HOST_WIDE_INT garbageh;
1243 tree type = TREE_TYPE (arg1);
1244 int uns = TREE_UNSIGNED (type);
1246 = (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type));
1248 int no_overflow = 0;
1250 int1l = TREE_INT_CST_LOW (arg1);
1251 int1h = TREE_INT_CST_HIGH (arg1);
1252 int2l = TREE_INT_CST_LOW (arg2);
1253 int2h = TREE_INT_CST_HIGH (arg2);
1258 low = int1l | int2l, hi = int1h | int2h;
1262 low = int1l ^ int2l, hi = int1h ^ int2h;
1266 low = int1l & int2l, hi = int1h & int2h;
1272 /* It's unclear from the C standard whether shifts can overflow.
1273 The following code ignores overflow; perhaps a C standard
1274 interpretation ruling is needed. */
1275 lshift_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1283 lrotate_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1288 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1292 neg_double (int2l, int2h, &low, &hi);
1293 add_double (int1l, int1h, low, hi, &low, &hi);
1294 overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
1298 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1301 case TRUNC_DIV_EXPR:
1302 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1303 case EXACT_DIV_EXPR:
1304 /* This is a shortcut for a common special case. */
1305 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1306 && ! TREE_CONSTANT_OVERFLOW (arg1)
1307 && ! TREE_CONSTANT_OVERFLOW (arg2)
1308 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1310 if (code == CEIL_DIV_EXPR)
1313 low = int1l / int2l, hi = 0;
1317 /* ... fall through ... */
1319 case ROUND_DIV_EXPR:
1320 if (int2h == 0 && int2l == 1)
1322 low = int1l, hi = int1h;
1325 if (int1l == int2l && int1h == int2h
1326 && ! (int1l == 0 && int1h == 0))
1331 overflow = div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
1332 &low, &hi, &garbagel, &garbageh);
1335 case TRUNC_MOD_EXPR:
1336 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1337 /* This is a shortcut for a common special case. */
1338 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1339 && ! TREE_CONSTANT_OVERFLOW (arg1)
1340 && ! TREE_CONSTANT_OVERFLOW (arg2)
1341 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1343 if (code == CEIL_MOD_EXPR)
1345 low = int1l % int2l, hi = 0;
1349 /* ... fall through ... */
1351 case ROUND_MOD_EXPR:
1352 overflow = div_and_round_double (code, uns,
1353 int1l, int1h, int2l, int2h,
1354 &garbagel, &garbageh, &low, &hi);
1360 low = (((unsigned HOST_WIDE_INT) int1h
1361 < (unsigned HOST_WIDE_INT) int2h)
1362 || (((unsigned HOST_WIDE_INT) int1h
1363 == (unsigned HOST_WIDE_INT) int2h)
1366 low = (int1h < int2h
1367 || (int1h == int2h && int1l < int2l));
1369 if (low == (code == MIN_EXPR))
1370 low = int1l, hi = int1h;
1372 low = int2l, hi = int2h;
1379 /* If this is for a sizetype, can be represented as one (signed)
1380 HOST_WIDE_INT word, and doesn't overflow, use size_int since it caches
1383 && ((hi == 0 && (HOST_WIDE_INT) low >= 0)
1384 || (hi == -1 && (HOST_WIDE_INT) low < 0))
1385 && overflow == 0 && ! TREE_OVERFLOW (arg1) && ! TREE_OVERFLOW (arg2))
1386 return size_int_type_wide (low, type);
1389 t = build_int_2 (low, hi);
1390 TREE_TYPE (t) = TREE_TYPE (arg1);
1395 ? (!uns || is_sizetype) && overflow
1396 : (force_fit_type (t, (!uns || is_sizetype) && overflow)
1398 | TREE_OVERFLOW (arg1)
1399 | TREE_OVERFLOW (arg2));
1401 /* If we're doing a size calculation, unsigned arithmetic does overflow.
1402 So check if force_fit_type truncated the value. */
1404 && ! TREE_OVERFLOW (t)
1405 && (TREE_INT_CST_HIGH (t) != hi
1406 || TREE_INT_CST_LOW (t) != low))
1407 TREE_OVERFLOW (t) = 1;
1409 TREE_CONSTANT_OVERFLOW (t) = (TREE_OVERFLOW (t)
1410 | TREE_CONSTANT_OVERFLOW (arg1)
1411 | TREE_CONSTANT_OVERFLOW (arg2));
1415 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1416 constant. We assume ARG1 and ARG2 have the same data type, or at least
1417 are the same kind of constant and the same machine mode.
1419 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1422 const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1427 if (TREE_CODE (arg1) == INTEGER_CST)
1428 return int_const_binop (code, arg1, arg2, notrunc);
1430 if (TREE_CODE (arg1) == REAL_CST)
1432 enum machine_mode mode;
1435 REAL_VALUE_TYPE value;
1438 d1 = TREE_REAL_CST (arg1);
1439 d2 = TREE_REAL_CST (arg2);
1441 type = TREE_TYPE (arg1);
1442 mode = TYPE_MODE (type);
1444 /* Don't perform operation if we honor signaling NaNs and
1445 either operand is a NaN. */
1446 if (HONOR_SNANS (mode)
1447 && (REAL_VALUE_ISNAN (d1) || REAL_VALUE_ISNAN (d2)))
1450 /* Don't perform operation if it would raise a division
1451 by zero exception. */
1452 if (code == RDIV_EXPR
1453 && REAL_VALUES_EQUAL (d2, dconst0)
1454 && (flag_trapping_math || ! MODE_HAS_INFINITIES (mode)))
1457 /* If either operand is a NaN, just return it. Otherwise, set up
1458 for floating-point trap; we return an overflow. */
1459 if (REAL_VALUE_ISNAN (d1))
1461 else if (REAL_VALUE_ISNAN (d2))
1464 REAL_ARITHMETIC (value, code, d1, d2);
1466 t = build_real (type, real_value_truncate (mode, value));
1469 = (force_fit_type (t, 0)
1470 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
1471 TREE_CONSTANT_OVERFLOW (t)
1473 | TREE_CONSTANT_OVERFLOW (arg1)
1474 | TREE_CONSTANT_OVERFLOW (arg2);
1477 if (TREE_CODE (arg1) == COMPLEX_CST)
1479 tree type = TREE_TYPE (arg1);
1480 tree r1 = TREE_REALPART (arg1);
1481 tree i1 = TREE_IMAGPART (arg1);
1482 tree r2 = TREE_REALPART (arg2);
1483 tree i2 = TREE_IMAGPART (arg2);
1489 t = build_complex (type,
1490 const_binop (PLUS_EXPR, r1, r2, notrunc),
1491 const_binop (PLUS_EXPR, i1, i2, notrunc));
1495 t = build_complex (type,
1496 const_binop (MINUS_EXPR, r1, r2, notrunc),
1497 const_binop (MINUS_EXPR, i1, i2, notrunc));
1501 t = build_complex (type,
1502 const_binop (MINUS_EXPR,
1503 const_binop (MULT_EXPR,
1505 const_binop (MULT_EXPR,
1508 const_binop (PLUS_EXPR,
1509 const_binop (MULT_EXPR,
1511 const_binop (MULT_EXPR,
1519 = const_binop (PLUS_EXPR,
1520 const_binop (MULT_EXPR, r2, r2, notrunc),
1521 const_binop (MULT_EXPR, i2, i2, notrunc),
1524 t = build_complex (type,
1526 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1527 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1528 const_binop (PLUS_EXPR,
1529 const_binop (MULT_EXPR, r1, r2,
1531 const_binop (MULT_EXPR, i1, i2,
1534 magsquared, notrunc),
1536 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1537 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1538 const_binop (MINUS_EXPR,
1539 const_binop (MULT_EXPR, i1, r2,
1541 const_binop (MULT_EXPR, r1, i2,
1544 magsquared, notrunc));
1556 /* These are the hash table functions for the hash table of INTEGER_CST
1557 nodes of a sizetype. */
1559 /* Return the hash code code X, an INTEGER_CST. */
1562 size_htab_hash (const void *x)
1566 return (TREE_INT_CST_HIGH (t) ^ TREE_INT_CST_LOW (t)
1567 ^ htab_hash_pointer (TREE_TYPE (t))
1568 ^ (TREE_OVERFLOW (t) << 20));
1571 /* Return nonzero if the value represented by *X (an INTEGER_CST tree node)
1572 is the same as that given by *Y, which is the same. */
1575 size_htab_eq (const void *x, const void *y)
1580 return (TREE_INT_CST_HIGH (xt) == TREE_INT_CST_HIGH (yt)
1581 && TREE_INT_CST_LOW (xt) == TREE_INT_CST_LOW (yt)
1582 && TREE_TYPE (xt) == TREE_TYPE (yt)
1583 && TREE_OVERFLOW (xt) == TREE_OVERFLOW (yt));
1586 /* Return an INTEGER_CST with value whose low-order HOST_BITS_PER_WIDE_INT
1587 bits are given by NUMBER and of the sizetype represented by KIND. */
1590 size_int_wide (HOST_WIDE_INT number, enum size_type_kind kind)
1592 return size_int_type_wide (number, sizetype_tab[(int) kind]);
1595 /* Likewise, but the desired type is specified explicitly. */
1597 static GTY (()) tree new_const;
1598 static GTY ((if_marked ("ggc_marked_p"), param_is (union tree_node)))
1602 size_int_type_wide (HOST_WIDE_INT number, tree type)
1608 size_htab = htab_create_ggc (1024, size_htab_hash, size_htab_eq, NULL);
1609 new_const = make_node (INTEGER_CST);
1612 /* Adjust NEW_CONST to be the constant we want. If it's already in the
1613 hash table, we return the value from the hash table. Otherwise, we
1614 place that in the hash table and make a new node for the next time. */
1615 TREE_INT_CST_LOW (new_const) = number;
1616 TREE_INT_CST_HIGH (new_const) = number < 0 ? -1 : 0;
1617 TREE_TYPE (new_const) = type;
1618 TREE_OVERFLOW (new_const) = TREE_CONSTANT_OVERFLOW (new_const)
1619 = force_fit_type (new_const, 0);
1621 slot = htab_find_slot (size_htab, new_const, INSERT);
1627 new_const = make_node (INTEGER_CST);
1631 return (tree) *slot;
1634 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1635 is a tree code. The type of the result is taken from the operands.
1636 Both must be the same type integer type and it must be a size type.
1637 If the operands are constant, so is the result. */
1640 size_binop (enum tree_code code, tree arg0, tree arg1)
1642 tree type = TREE_TYPE (arg0);
1644 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1645 || type != TREE_TYPE (arg1))
1648 /* Handle the special case of two integer constants faster. */
1649 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1651 /* And some specific cases even faster than that. */
1652 if (code == PLUS_EXPR && integer_zerop (arg0))
1654 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1655 && integer_zerop (arg1))
1657 else if (code == MULT_EXPR && integer_onep (arg0))
1660 /* Handle general case of two integer constants. */
1661 return int_const_binop (code, arg0, arg1, 0);
1664 if (arg0 == error_mark_node || arg1 == error_mark_node)
1665 return error_mark_node;
1667 return fold (build (code, type, arg0, arg1));
1670 /* Given two values, either both of sizetype or both of bitsizetype,
1671 compute the difference between the two values. Return the value
1672 in signed type corresponding to the type of the operands. */
1675 size_diffop (tree arg0, tree arg1)
1677 tree type = TREE_TYPE (arg0);
1680 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1681 || type != TREE_TYPE (arg1))
1684 /* If the type is already signed, just do the simple thing. */
1685 if (! TREE_UNSIGNED (type))
1686 return size_binop (MINUS_EXPR, arg0, arg1);
1688 ctype = (type == bitsizetype || type == ubitsizetype
1689 ? sbitsizetype : ssizetype);
1691 /* If either operand is not a constant, do the conversions to the signed
1692 type and subtract. The hardware will do the right thing with any
1693 overflow in the subtraction. */
1694 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
1695 return size_binop (MINUS_EXPR, fold_convert (ctype, arg0),
1696 fold_convert (ctype, arg1));
1698 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
1699 Otherwise, subtract the other way, convert to CTYPE (we know that can't
1700 overflow) and negate (which can't either). Special-case a result
1701 of zero while we're here. */
1702 if (tree_int_cst_equal (arg0, arg1))
1703 return fold_convert (ctype, integer_zero_node);
1704 else if (tree_int_cst_lt (arg1, arg0))
1705 return fold_convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
1707 return size_binop (MINUS_EXPR, fold_convert (ctype, integer_zero_node),
1708 fold_convert (ctype, size_binop (MINUS_EXPR,
1713 /* Attempt to fold type conversion operation CODE of expression ARG1 to
1714 type TYPE. If no simplification can be done return NULL_TREE. */
1717 fold_convert_const (enum tree_code code, tree type, tree arg1)
1722 if (TREE_TYPE (arg1) == type)
1725 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
1727 if (TREE_CODE (arg1) == INTEGER_CST)
1729 /* If we would build a constant wider than GCC supports,
1730 leave the conversion unfolded. */
1731 if (TYPE_PRECISION (type) > 2 * HOST_BITS_PER_WIDE_INT)
1734 /* If we are trying to make a sizetype for a small integer, use
1735 size_int to pick up cached types to reduce duplicate nodes. */
1736 if (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type)
1737 && !TREE_CONSTANT_OVERFLOW (arg1)
1738 && compare_tree_int (arg1, 10000) < 0)
1739 return size_int_type_wide (TREE_INT_CST_LOW (arg1), type);
1741 /* Given an integer constant, make new constant with new type,
1742 appropriately sign-extended or truncated. */
1743 t = build_int_2 (TREE_INT_CST_LOW (arg1),
1744 TREE_INT_CST_HIGH (arg1));
1745 TREE_TYPE (t) = type;
1746 /* Indicate an overflow if (1) ARG1 already overflowed,
1747 or (2) force_fit_type indicates an overflow.
1748 Tell force_fit_type that an overflow has already occurred
1749 if ARG1 is a too-large unsigned value and T is signed.
1750 But don't indicate an overflow if converting a pointer. */
1752 = ((force_fit_type (t,
1753 (TREE_INT_CST_HIGH (arg1) < 0
1754 && (TREE_UNSIGNED (type)
1755 < TREE_UNSIGNED (TREE_TYPE (arg1)))))
1756 && ! POINTER_TYPE_P (TREE_TYPE (arg1)))
1757 || TREE_OVERFLOW (arg1));
1758 TREE_CONSTANT_OVERFLOW (t)
1759 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1762 else if (TREE_CODE (arg1) == REAL_CST)
1764 /* The following code implements the floating point to integer
1765 conversion rules required by the Java Language Specification,
1766 that IEEE NaNs are mapped to zero and values that overflow
1767 the target precision saturate, i.e. values greater than
1768 INT_MAX are mapped to INT_MAX, and values less than INT_MIN
1769 are mapped to INT_MIN. These semantics are allowed by the
1770 C and C++ standards that simply state that the behavior of
1771 FP-to-integer conversion is unspecified upon overflow. */
1773 HOST_WIDE_INT high, low;
1776 REAL_VALUE_TYPE x = TREE_REAL_CST (arg1);
1780 case FIX_TRUNC_EXPR:
1781 real_trunc (&r, VOIDmode, &x);
1785 real_ceil (&r, VOIDmode, &x);
1788 case FIX_FLOOR_EXPR:
1789 real_floor (&r, VOIDmode, &x);
1796 /* If R is NaN, return zero and show we have an overflow. */
1797 if (REAL_VALUE_ISNAN (r))
1804 /* See if R is less than the lower bound or greater than the
1809 tree lt = TYPE_MIN_VALUE (type);
1810 REAL_VALUE_TYPE l = real_value_from_int_cst (NULL_TREE, lt);
1811 if (REAL_VALUES_LESS (r, l))
1814 high = TREE_INT_CST_HIGH (lt);
1815 low = TREE_INT_CST_LOW (lt);
1821 tree ut = TYPE_MAX_VALUE (type);
1824 REAL_VALUE_TYPE u = real_value_from_int_cst (NULL_TREE, ut);
1825 if (REAL_VALUES_LESS (u, r))
1828 high = TREE_INT_CST_HIGH (ut);
1829 low = TREE_INT_CST_LOW (ut);
1835 REAL_VALUE_TO_INT (&low, &high, r);
1837 t = build_int_2 (low, high);
1838 TREE_TYPE (t) = type;
1840 = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
1841 TREE_CONSTANT_OVERFLOW (t)
1842 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1846 else if (TREE_CODE (type) == REAL_TYPE)
1848 if (TREE_CODE (arg1) == INTEGER_CST)
1849 return build_real_from_int_cst (type, arg1);
1850 if (TREE_CODE (arg1) == REAL_CST)
1852 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
1854 /* We make a copy of ARG1 so that we don't modify an
1855 existing constant tree. */
1856 t = copy_node (arg1);
1857 TREE_TYPE (t) = type;
1861 t = build_real (type,
1862 real_value_truncate (TYPE_MODE (type),
1863 TREE_REAL_CST (arg1)));
1866 = TREE_OVERFLOW (arg1) | force_fit_type (t, 0);
1867 TREE_CONSTANT_OVERFLOW (t)
1868 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1875 /* Convert expression ARG to type TYPE. Used by the middle-end for
1876 simple conversions in preference to calling the front-end's convert. */
1879 fold_convert (tree type, tree arg)
1881 tree orig = TREE_TYPE (arg);
1887 if (TREE_CODE (arg) == ERROR_MARK
1888 || TREE_CODE (type) == ERROR_MARK
1889 || TREE_CODE (orig) == ERROR_MARK)
1890 return error_mark_node;
1892 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig))
1893 return fold (build1 (NOP_EXPR, type, arg));
1895 if (INTEGRAL_TYPE_P (type) || POINTER_TYPE_P (type))
1897 if (TREE_CODE (arg) == INTEGER_CST)
1899 tem = fold_convert_const (NOP_EXPR, type, arg);
1900 if (tem != NULL_TREE)
1903 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig))
1904 return fold (build1 (NOP_EXPR, type, arg));
1905 if (TREE_CODE (orig) == COMPLEX_TYPE)
1907 tem = fold (build1 (REALPART_EXPR, TREE_TYPE (orig), arg));
1908 return fold_convert (type, tem);
1910 if (TREE_CODE (orig) == VECTOR_TYPE
1911 && GET_MODE_SIZE (TYPE_MODE (type))
1912 == GET_MODE_SIZE (TYPE_MODE (orig)))
1913 return fold (build1 (NOP_EXPR, type, arg));
1915 else if (TREE_CODE (type) == REAL_TYPE)
1917 if (TREE_CODE (arg) == INTEGER_CST)
1919 tem = fold_convert_const (FLOAT_EXPR, type, arg);
1920 if (tem != NULL_TREE)
1923 else if (TREE_CODE (arg) == REAL_CST)
1925 tem = fold_convert_const (NOP_EXPR, type, arg);
1926 if (tem != NULL_TREE)
1930 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig))
1931 return fold (build1 (FLOAT_EXPR, type, arg));
1932 if (TREE_CODE (orig) == REAL_TYPE)
1933 return fold (build1 (flag_float_store ? CONVERT_EXPR : NOP_EXPR,
1935 if (TREE_CODE (orig) == COMPLEX_TYPE)
1937 tem = fold (build1 (REALPART_EXPR, TREE_TYPE (orig), arg));
1938 return fold_convert (type, tem);
1941 else if (TREE_CODE (type) == COMPLEX_TYPE)
1943 if (INTEGRAL_TYPE_P (orig)
1944 || POINTER_TYPE_P (orig)
1945 || TREE_CODE (orig) == REAL_TYPE)
1946 return build (COMPLEX_EXPR, type,
1947 fold_convert (TREE_TYPE (type), arg),
1948 fold_convert (TREE_TYPE (type), integer_zero_node));
1949 if (TREE_CODE (orig) == COMPLEX_TYPE)
1953 if (TREE_CODE (arg) == COMPLEX_EXPR)
1955 rpart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 0));
1956 ipart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 1));
1957 return fold (build (COMPLEX_EXPR, type, rpart, ipart));
1960 arg = save_expr (arg);
1961 rpart = fold (build1 (REALPART_EXPR, TREE_TYPE (orig), arg));
1962 ipart = fold (build1 (IMAGPART_EXPR, TREE_TYPE (orig), arg));
1963 rpart = fold_convert (TREE_TYPE (type), rpart);
1964 ipart = fold_convert (TREE_TYPE (type), ipart);
1965 return fold (build (COMPLEX_EXPR, type, rpart, ipart));
1968 else if (TREE_CODE (type) == VECTOR_TYPE)
1970 if ((INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig))
1971 && GET_MODE_SIZE (TYPE_MODE (type))
1972 == GET_MODE_SIZE (TYPE_MODE (orig)))
1973 return fold (build1 (NOP_EXPR, type, arg));
1974 if (TREE_CODE (orig) == VECTOR_TYPE
1975 && GET_MODE_SIZE (TYPE_MODE (type))
1976 == GET_MODE_SIZE (TYPE_MODE (orig)))
1977 return fold (build1 (NOP_EXPR, type, arg));
1979 else if (VOID_TYPE_P (type))
1980 return fold (build1 (CONVERT_EXPR, type, arg));
1984 /* Return an expr equal to X but certainly not valid as an lvalue. */
1991 /* These things are certainly not lvalues. */
1992 if (TREE_CODE (x) == NON_LVALUE_EXPR
1993 || TREE_CODE (x) == INTEGER_CST
1994 || TREE_CODE (x) == REAL_CST
1995 || TREE_CODE (x) == STRING_CST
1996 || TREE_CODE (x) == ADDR_EXPR)
1999 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
2000 TREE_CONSTANT (result) = TREE_CONSTANT (x);
2004 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
2005 Zero means allow extended lvalues. */
2007 int pedantic_lvalues;
2009 /* When pedantic, return an expr equal to X but certainly not valid as a
2010 pedantic lvalue. Otherwise, return X. */
2013 pedantic_non_lvalue (tree x)
2015 if (pedantic_lvalues)
2016 return non_lvalue (x);
2021 /* Given a tree comparison code, return the code that is the logical inverse
2022 of the given code. It is not safe to do this for floating-point
2023 comparisons, except for NE_EXPR and EQ_EXPR. */
2025 static enum tree_code
2026 invert_tree_comparison (enum tree_code code)
2047 /* Similar, but return the comparison that results if the operands are
2048 swapped. This is safe for floating-point. */
2050 static enum tree_code
2051 swap_tree_comparison (enum tree_code code)
2072 /* Convert a comparison tree code from an enum tree_code representation
2073 into a compcode bit-based encoding. This function is the inverse of
2074 compcode_to_comparison. */
2077 comparison_to_compcode (enum tree_code code)
2098 /* Convert a compcode bit-based encoding of a comparison operator back
2099 to GCC's enum tree_code representation. This function is the
2100 inverse of comparison_to_compcode. */
2102 static enum tree_code
2103 compcode_to_comparison (int code)
2124 /* Return nonzero if CODE is a tree code that represents a truth value. */
2127 truth_value_p (enum tree_code code)
2129 return (TREE_CODE_CLASS (code) == '<'
2130 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2131 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2132 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
2135 /* Return nonzero if two operands (typically of the same tree node)
2136 are necessarily equal. If either argument has side-effects this
2137 function returns zero.
2139 If ONLY_CONST is nonzero, only return nonzero for constants.
2140 This function tests whether the operands are indistinguishable;
2141 it does not test whether they are equal using C's == operation.
2142 The distinction is important for IEEE floating point, because
2143 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2144 (2) two NaNs may be indistinguishable, but NaN!=NaN.
2146 If ONLY_CONST is zero, a VAR_DECL is considered equal to itself
2147 even though it may hold multiple values during a function.
2148 This is because a GCC tree node guarantees that nothing else is
2149 executed between the evaluation of its "operands" (which may often
2150 be evaluated in arbitrary order). Hence if the operands themselves
2151 don't side-effect, the VAR_DECLs, PARM_DECLs etc... must hold the
2152 same value in each operand/subexpression. Hence a zero value for
2153 ONLY_CONST assumes isochronic (or instantaneous) tree equivalence.
2154 If comparing arbitrary expression trees, such as from different
2155 statements, ONLY_CONST must usually be nonzero. */
2158 operand_equal_p (tree arg0, tree arg1, int only_const)
2162 /* If both types don't have the same signedness, then we can't consider
2163 them equal. We must check this before the STRIP_NOPS calls
2164 because they may change the signedness of the arguments. */
2165 if (TREE_UNSIGNED (TREE_TYPE (arg0)) != TREE_UNSIGNED (TREE_TYPE (arg1)))
2171 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2172 /* This is needed for conversions and for COMPONENT_REF.
2173 Might as well play it safe and always test this. */
2174 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
2175 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
2176 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
2179 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
2180 We don't care about side effects in that case because the SAVE_EXPR
2181 takes care of that for us. In all other cases, two expressions are
2182 equal if they have no side effects. If we have two identical
2183 expressions with side effects that should be treated the same due
2184 to the only side effects being identical SAVE_EXPR's, that will
2185 be detected in the recursive calls below. */
2186 if (arg0 == arg1 && ! only_const
2187 && (TREE_CODE (arg0) == SAVE_EXPR
2188 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
2191 /* Next handle constant cases, those for which we can return 1 even
2192 if ONLY_CONST is set. */
2193 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
2194 switch (TREE_CODE (arg0))
2197 return (! TREE_CONSTANT_OVERFLOW (arg0)
2198 && ! TREE_CONSTANT_OVERFLOW (arg1)
2199 && tree_int_cst_equal (arg0, arg1));
2202 return (! TREE_CONSTANT_OVERFLOW (arg0)
2203 && ! TREE_CONSTANT_OVERFLOW (arg1)
2204 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
2205 TREE_REAL_CST (arg1)));
2211 if (TREE_CONSTANT_OVERFLOW (arg0)
2212 || TREE_CONSTANT_OVERFLOW (arg1))
2215 v1 = TREE_VECTOR_CST_ELTS (arg0);
2216 v2 = TREE_VECTOR_CST_ELTS (arg1);
2219 if (!operand_equal_p (TREE_VALUE (v1), TREE_VALUE (v2),
2222 v1 = TREE_CHAIN (v1);
2223 v2 = TREE_CHAIN (v2);
2230 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
2232 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
2236 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
2237 && ! memcmp (TREE_STRING_POINTER (arg0),
2238 TREE_STRING_POINTER (arg1),
2239 TREE_STRING_LENGTH (arg0)));
2242 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
2251 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
2254 /* Two conversions are equal only if signedness and modes match. */
2255 if ((TREE_CODE (arg0) == NOP_EXPR || TREE_CODE (arg0) == CONVERT_EXPR)
2256 && (TREE_UNSIGNED (TREE_TYPE (arg0))
2257 != TREE_UNSIGNED (TREE_TYPE (arg1))))
2260 return operand_equal_p (TREE_OPERAND (arg0, 0),
2261 TREE_OPERAND (arg1, 0), 0);
2265 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0)
2266 && operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1),
2270 /* For commutative ops, allow the other order. */
2271 return (commutative_tree_code (TREE_CODE (arg0))
2272 && operand_equal_p (TREE_OPERAND (arg0, 0),
2273 TREE_OPERAND (arg1, 1), 0)
2274 && operand_equal_p (TREE_OPERAND (arg0, 1),
2275 TREE_OPERAND (arg1, 0), 0));
2278 /* If either of the pointer (or reference) expressions we are
2279 dereferencing contain a side effect, these cannot be equal. */
2280 if (TREE_SIDE_EFFECTS (arg0)
2281 || TREE_SIDE_EFFECTS (arg1))
2284 switch (TREE_CODE (arg0))
2287 return operand_equal_p (TREE_OPERAND (arg0, 0),
2288 TREE_OPERAND (arg1, 0), 0);
2292 case ARRAY_RANGE_REF:
2293 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2294 TREE_OPERAND (arg1, 0), 0)
2295 && operand_equal_p (TREE_OPERAND (arg0, 1),
2296 TREE_OPERAND (arg1, 1), 0));
2299 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2300 TREE_OPERAND (arg1, 0), 0)
2301 && operand_equal_p (TREE_OPERAND (arg0, 1),
2302 TREE_OPERAND (arg1, 1), 0)
2303 && operand_equal_p (TREE_OPERAND (arg0, 2),
2304 TREE_OPERAND (arg1, 2), 0));
2310 switch (TREE_CODE (arg0))
2313 case TRUTH_NOT_EXPR:
2314 return operand_equal_p (TREE_OPERAND (arg0, 0),
2315 TREE_OPERAND (arg1, 0), 0);
2318 return rtx_equal_p (RTL_EXPR_RTL (arg0), RTL_EXPR_RTL (arg1));
2321 /* If the CALL_EXPRs call different functions, then they
2322 clearly can not be equal. */
2323 if (! operand_equal_p (TREE_OPERAND (arg0, 0),
2324 TREE_OPERAND (arg1, 0), 0))
2327 /* Only consider const functions equivalent. */
2328 fndecl = get_callee_fndecl (arg0);
2329 if (fndecl == NULL_TREE
2330 || ! (flags_from_decl_or_type (fndecl) & ECF_CONST))
2333 /* Now see if all the arguments are the same. operand_equal_p
2334 does not handle TREE_LIST, so we walk the operands here
2335 feeding them to operand_equal_p. */
2336 arg0 = TREE_OPERAND (arg0, 1);
2337 arg1 = TREE_OPERAND (arg1, 1);
2338 while (arg0 && arg1)
2340 if (! operand_equal_p (TREE_VALUE (arg0), TREE_VALUE (arg1), 0))
2343 arg0 = TREE_CHAIN (arg0);
2344 arg1 = TREE_CHAIN (arg1);
2347 /* If we get here and both argument lists are exhausted
2348 then the CALL_EXPRs are equal. */
2349 return ! (arg0 || arg1);
2356 /* Consider __builtin_sqrt equal to sqrt. */
2357 return TREE_CODE (arg0) == FUNCTION_DECL
2358 && DECL_BUILT_IN (arg0) && DECL_BUILT_IN (arg1)
2359 && DECL_BUILT_IN_CLASS (arg0) == DECL_BUILT_IN_CLASS (arg1)
2360 && DECL_FUNCTION_CODE (arg0) == DECL_FUNCTION_CODE (arg1);
2367 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2368 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2370 When in doubt, return 0. */
2373 operand_equal_for_comparison_p (tree arg0, tree arg1, tree other)
2375 int unsignedp1, unsignedpo;
2376 tree primarg0, primarg1, primother;
2377 unsigned int correct_width;
2379 if (operand_equal_p (arg0, arg1, 0))
2382 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
2383 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
2386 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2387 and see if the inner values are the same. This removes any
2388 signedness comparison, which doesn't matter here. */
2389 primarg0 = arg0, primarg1 = arg1;
2390 STRIP_NOPS (primarg0);
2391 STRIP_NOPS (primarg1);
2392 if (operand_equal_p (primarg0, primarg1, 0))
2395 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2396 actual comparison operand, ARG0.
2398 First throw away any conversions to wider types
2399 already present in the operands. */
2401 primarg1 = get_narrower (arg1, &unsignedp1);
2402 primother = get_narrower (other, &unsignedpo);
2404 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
2405 if (unsignedp1 == unsignedpo
2406 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
2407 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
2409 tree type = TREE_TYPE (arg0);
2411 /* Make sure shorter operand is extended the right way
2412 to match the longer operand. */
2413 primarg1 = fold_convert (lang_hooks.types.signed_or_unsigned_type
2414 (unsignedp1, TREE_TYPE (primarg1)), primarg1);
2416 if (operand_equal_p (arg0, fold_convert (type, primarg1), 0))
2423 /* See if ARG is an expression that is either a comparison or is performing
2424 arithmetic on comparisons. The comparisons must only be comparing
2425 two different values, which will be stored in *CVAL1 and *CVAL2; if
2426 they are nonzero it means that some operands have already been found.
2427 No variables may be used anywhere else in the expression except in the
2428 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2429 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2431 If this is true, return 1. Otherwise, return zero. */
2434 twoval_comparison_p (tree arg, tree *cval1, tree *cval2, int *save_p)
2436 enum tree_code code = TREE_CODE (arg);
2437 char class = TREE_CODE_CLASS (code);
2439 /* We can handle some of the 'e' cases here. */
2440 if (class == 'e' && code == TRUTH_NOT_EXPR)
2442 else if (class == 'e'
2443 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
2444 || code == COMPOUND_EXPR))
2447 else if (class == 'e' && code == SAVE_EXPR && SAVE_EXPR_RTL (arg) == 0
2448 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
2450 /* If we've already found a CVAL1 or CVAL2, this expression is
2451 two complex to handle. */
2452 if (*cval1 || *cval2)
2462 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
2465 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
2466 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2467 cval1, cval2, save_p));
2473 if (code == COND_EXPR)
2474 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
2475 cval1, cval2, save_p)
2476 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2477 cval1, cval2, save_p)
2478 && twoval_comparison_p (TREE_OPERAND (arg, 2),
2479 cval1, cval2, save_p));
2483 /* First see if we can handle the first operand, then the second. For
2484 the second operand, we know *CVAL1 can't be zero. It must be that
2485 one side of the comparison is each of the values; test for the
2486 case where this isn't true by failing if the two operands
2489 if (operand_equal_p (TREE_OPERAND (arg, 0),
2490 TREE_OPERAND (arg, 1), 0))
2494 *cval1 = TREE_OPERAND (arg, 0);
2495 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
2497 else if (*cval2 == 0)
2498 *cval2 = TREE_OPERAND (arg, 0);
2499 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
2504 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
2506 else if (*cval2 == 0)
2507 *cval2 = TREE_OPERAND (arg, 1);
2508 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
2520 /* ARG is a tree that is known to contain just arithmetic operations and
2521 comparisons. Evaluate the operations in the tree substituting NEW0 for
2522 any occurrence of OLD0 as an operand of a comparison and likewise for
2526 eval_subst (tree arg, tree old0, tree new0, tree old1, tree new1)
2528 tree type = TREE_TYPE (arg);
2529 enum tree_code code = TREE_CODE (arg);
2530 char class = TREE_CODE_CLASS (code);
2532 /* We can handle some of the 'e' cases here. */
2533 if (class == 'e' && code == TRUTH_NOT_EXPR)
2535 else if (class == 'e'
2536 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2542 return fold (build1 (code, type,
2543 eval_subst (TREE_OPERAND (arg, 0),
2544 old0, new0, old1, new1)));
2547 return fold (build (code, type,
2548 eval_subst (TREE_OPERAND (arg, 0),
2549 old0, new0, old1, new1),
2550 eval_subst (TREE_OPERAND (arg, 1),
2551 old0, new0, old1, new1)));
2557 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
2560 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
2563 return fold (build (code, type,
2564 eval_subst (TREE_OPERAND (arg, 0),
2565 old0, new0, old1, new1),
2566 eval_subst (TREE_OPERAND (arg, 1),
2567 old0, new0, old1, new1),
2568 eval_subst (TREE_OPERAND (arg, 2),
2569 old0, new0, old1, new1)));
2573 /* Fall through - ??? */
2577 tree arg0 = TREE_OPERAND (arg, 0);
2578 tree arg1 = TREE_OPERAND (arg, 1);
2580 /* We need to check both for exact equality and tree equality. The
2581 former will be true if the operand has a side-effect. In that
2582 case, we know the operand occurred exactly once. */
2584 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
2586 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
2589 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
2591 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
2594 return fold (build (code, type, arg0, arg1));
2602 /* Return a tree for the case when the result of an expression is RESULT
2603 converted to TYPE and OMITTED was previously an operand of the expression
2604 but is now not needed (e.g., we folded OMITTED * 0).
2606 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2607 the conversion of RESULT to TYPE. */
2610 omit_one_operand (tree type, tree result, tree omitted)
2612 tree t = fold_convert (type, result);
2614 if (TREE_SIDE_EFFECTS (omitted))
2615 return build (COMPOUND_EXPR, type, omitted, t);
2617 return non_lvalue (t);
2620 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2623 pedantic_omit_one_operand (tree type, tree result, tree omitted)
2625 tree t = fold_convert (type, result);
2627 if (TREE_SIDE_EFFECTS (omitted))
2628 return build (COMPOUND_EXPR, type, omitted, t);
2630 return pedantic_non_lvalue (t);
2633 /* Return a simplified tree node for the truth-negation of ARG. This
2634 never alters ARG itself. We assume that ARG is an operation that
2635 returns a truth value (0 or 1). */
2638 invert_truthvalue (tree arg)
2640 tree type = TREE_TYPE (arg);
2641 enum tree_code code = TREE_CODE (arg);
2643 if (code == ERROR_MARK)
2646 /* If this is a comparison, we can simply invert it, except for
2647 floating-point non-equality comparisons, in which case we just
2648 enclose a TRUTH_NOT_EXPR around what we have. */
2650 if (TREE_CODE_CLASS (code) == '<')
2652 if (FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg, 0)))
2653 && !flag_unsafe_math_optimizations
2656 return build1 (TRUTH_NOT_EXPR, type, arg);
2657 else if (code == UNORDERED_EXPR
2658 || code == ORDERED_EXPR
2659 || code == UNEQ_EXPR
2660 || code == UNLT_EXPR
2661 || code == UNLE_EXPR
2662 || code == UNGT_EXPR
2663 || code == UNGE_EXPR)
2664 return build1 (TRUTH_NOT_EXPR, type, arg);
2666 return build (invert_tree_comparison (code), type,
2667 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
2673 return fold_convert (type, build_int_2 (integer_zerop (arg), 0));
2675 case TRUTH_AND_EXPR:
2676 return build (TRUTH_OR_EXPR, type,
2677 invert_truthvalue (TREE_OPERAND (arg, 0)),
2678 invert_truthvalue (TREE_OPERAND (arg, 1)));
2681 return build (TRUTH_AND_EXPR, type,
2682 invert_truthvalue (TREE_OPERAND (arg, 0)),
2683 invert_truthvalue (TREE_OPERAND (arg, 1)));
2685 case TRUTH_XOR_EXPR:
2686 /* Here we can invert either operand. We invert the first operand
2687 unless the second operand is a TRUTH_NOT_EXPR in which case our
2688 result is the XOR of the first operand with the inside of the
2689 negation of the second operand. */
2691 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
2692 return build (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
2693 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
2695 return build (TRUTH_XOR_EXPR, type,
2696 invert_truthvalue (TREE_OPERAND (arg, 0)),
2697 TREE_OPERAND (arg, 1));
2699 case TRUTH_ANDIF_EXPR:
2700 return build (TRUTH_ORIF_EXPR, type,
2701 invert_truthvalue (TREE_OPERAND (arg, 0)),
2702 invert_truthvalue (TREE_OPERAND (arg, 1)));
2704 case TRUTH_ORIF_EXPR:
2705 return build (TRUTH_ANDIF_EXPR, type,
2706 invert_truthvalue (TREE_OPERAND (arg, 0)),
2707 invert_truthvalue (TREE_OPERAND (arg, 1)));
2709 case TRUTH_NOT_EXPR:
2710 return TREE_OPERAND (arg, 0);
2713 return build (COND_EXPR, type, TREE_OPERAND (arg, 0),
2714 invert_truthvalue (TREE_OPERAND (arg, 1)),
2715 invert_truthvalue (TREE_OPERAND (arg, 2)));
2718 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
2719 invert_truthvalue (TREE_OPERAND (arg, 1)));
2721 case WITH_RECORD_EXPR:
2722 return build (WITH_RECORD_EXPR, type,
2723 invert_truthvalue (TREE_OPERAND (arg, 0)),
2724 TREE_OPERAND (arg, 1));
2726 case NON_LVALUE_EXPR:
2727 return invert_truthvalue (TREE_OPERAND (arg, 0));
2732 return build1 (TREE_CODE (arg), type,
2733 invert_truthvalue (TREE_OPERAND (arg, 0)));
2736 if (!integer_onep (TREE_OPERAND (arg, 1)))
2738 return build (EQ_EXPR, type, arg,
2739 fold_convert (type, integer_zero_node));
2742 return build1 (TRUTH_NOT_EXPR, type, arg);
2744 case CLEANUP_POINT_EXPR:
2745 return build1 (CLEANUP_POINT_EXPR, type,
2746 invert_truthvalue (TREE_OPERAND (arg, 0)));
2751 if (TREE_CODE (TREE_TYPE (arg)) != BOOLEAN_TYPE)
2753 return build1 (TRUTH_NOT_EXPR, type, arg);
2756 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
2757 operands are another bit-wise operation with a common input. If so,
2758 distribute the bit operations to save an operation and possibly two if
2759 constants are involved. For example, convert
2760 (A | B) & (A | C) into A | (B & C)
2761 Further simplification will occur if B and C are constants.
2763 If this optimization cannot be done, 0 will be returned. */
2766 distribute_bit_expr (enum tree_code code, tree type, tree arg0, tree arg1)
2771 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2772 || TREE_CODE (arg0) == code
2773 || (TREE_CODE (arg0) != BIT_AND_EXPR
2774 && TREE_CODE (arg0) != BIT_IOR_EXPR))
2777 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
2779 common = TREE_OPERAND (arg0, 0);
2780 left = TREE_OPERAND (arg0, 1);
2781 right = TREE_OPERAND (arg1, 1);
2783 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
2785 common = TREE_OPERAND (arg0, 0);
2786 left = TREE_OPERAND (arg0, 1);
2787 right = TREE_OPERAND (arg1, 0);
2789 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
2791 common = TREE_OPERAND (arg0, 1);
2792 left = TREE_OPERAND (arg0, 0);
2793 right = TREE_OPERAND (arg1, 1);
2795 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
2797 common = TREE_OPERAND (arg0, 1);
2798 left = TREE_OPERAND (arg0, 0);
2799 right = TREE_OPERAND (arg1, 0);
2804 return fold (build (TREE_CODE (arg0), type, common,
2805 fold (build (code, type, left, right))));
2808 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
2809 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
2812 make_bit_field_ref (tree inner, tree type, int bitsize, int bitpos,
2815 tree result = build (BIT_FIELD_REF, type, inner,
2816 size_int (bitsize), bitsize_int (bitpos));
2818 TREE_UNSIGNED (result) = unsignedp;
2823 /* Optimize a bit-field compare.
2825 There are two cases: First is a compare against a constant and the
2826 second is a comparison of two items where the fields are at the same
2827 bit position relative to the start of a chunk (byte, halfword, word)
2828 large enough to contain it. In these cases we can avoid the shift
2829 implicit in bitfield extractions.
2831 For constants, we emit a compare of the shifted constant with the
2832 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
2833 compared. For two fields at the same position, we do the ANDs with the
2834 similar mask and compare the result of the ANDs.
2836 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
2837 COMPARE_TYPE is the type of the comparison, and LHS and RHS
2838 are the left and right operands of the comparison, respectively.
2840 If the optimization described above can be done, we return the resulting
2841 tree. Otherwise we return zero. */
2844 optimize_bit_field_compare (enum tree_code code, tree compare_type,
2847 HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
2848 tree type = TREE_TYPE (lhs);
2849 tree signed_type, unsigned_type;
2850 int const_p = TREE_CODE (rhs) == INTEGER_CST;
2851 enum machine_mode lmode, rmode, nmode;
2852 int lunsignedp, runsignedp;
2853 int lvolatilep = 0, rvolatilep = 0;
2854 tree linner, rinner = NULL_TREE;
2858 /* Get all the information about the extractions being done. If the bit size
2859 if the same as the size of the underlying object, we aren't doing an
2860 extraction at all and so can do nothing. We also don't want to
2861 do anything if the inner expression is a PLACEHOLDER_EXPR since we
2862 then will no longer be able to replace it. */
2863 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
2864 &lunsignedp, &lvolatilep);
2865 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
2866 || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
2871 /* If this is not a constant, we can only do something if bit positions,
2872 sizes, and signedness are the same. */
2873 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
2874 &runsignedp, &rvolatilep);
2876 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
2877 || lunsignedp != runsignedp || offset != 0
2878 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
2882 /* See if we can find a mode to refer to this field. We should be able to,
2883 but fail if we can't. */
2884 nmode = get_best_mode (lbitsize, lbitpos,
2885 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
2886 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
2887 TYPE_ALIGN (TREE_TYPE (rinner))),
2888 word_mode, lvolatilep || rvolatilep);
2889 if (nmode == VOIDmode)
2892 /* Set signed and unsigned types of the precision of this mode for the
2894 signed_type = lang_hooks.types.type_for_mode (nmode, 0);
2895 unsigned_type = lang_hooks.types.type_for_mode (nmode, 1);
2897 /* Compute the bit position and size for the new reference and our offset
2898 within it. If the new reference is the same size as the original, we
2899 won't optimize anything, so return zero. */
2900 nbitsize = GET_MODE_BITSIZE (nmode);
2901 nbitpos = lbitpos & ~ (nbitsize - 1);
2903 if (nbitsize == lbitsize)
2906 if (BYTES_BIG_ENDIAN)
2907 lbitpos = nbitsize - lbitsize - lbitpos;
2909 /* Make the mask to be used against the extracted field. */
2910 mask = build_int_2 (~0, ~0);
2911 TREE_TYPE (mask) = unsigned_type;
2912 force_fit_type (mask, 0);
2913 mask = fold_convert (unsigned_type, mask);
2914 mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
2915 mask = const_binop (RSHIFT_EXPR, mask,
2916 size_int (nbitsize - lbitsize - lbitpos), 0);
2919 /* If not comparing with constant, just rework the comparison
2921 return build (code, compare_type,
2922 build (BIT_AND_EXPR, unsigned_type,
2923 make_bit_field_ref (linner, unsigned_type,
2924 nbitsize, nbitpos, 1),
2926 build (BIT_AND_EXPR, unsigned_type,
2927 make_bit_field_ref (rinner, unsigned_type,
2928 nbitsize, nbitpos, 1),
2931 /* Otherwise, we are handling the constant case. See if the constant is too
2932 big for the field. Warn and return a tree of for 0 (false) if so. We do
2933 this not only for its own sake, but to avoid having to test for this
2934 error case below. If we didn't, we might generate wrong code.
2936 For unsigned fields, the constant shifted right by the field length should
2937 be all zero. For signed fields, the high-order bits should agree with
2942 if (! integer_zerop (const_binop (RSHIFT_EXPR,
2943 fold_convert (unsigned_type, rhs),
2944 size_int (lbitsize), 0)))
2946 warning ("comparison is always %d due to width of bit-field",
2948 return fold_convert (compare_type,
2950 ? integer_one_node : integer_zero_node));
2955 tree tem = const_binop (RSHIFT_EXPR, fold_convert (signed_type, rhs),
2956 size_int (lbitsize - 1), 0);
2957 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
2959 warning ("comparison is always %d due to width of bit-field",
2961 return fold_convert (compare_type,
2963 ? integer_one_node : integer_zero_node));
2967 /* Single-bit compares should always be against zero. */
2968 if (lbitsize == 1 && ! integer_zerop (rhs))
2970 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
2971 rhs = fold_convert (type, integer_zero_node);
2974 /* Make a new bitfield reference, shift the constant over the
2975 appropriate number of bits and mask it with the computed mask
2976 (in case this was a signed field). If we changed it, make a new one. */
2977 lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1);
2980 TREE_SIDE_EFFECTS (lhs) = 1;
2981 TREE_THIS_VOLATILE (lhs) = 1;
2984 rhs = fold (const_binop (BIT_AND_EXPR,
2985 const_binop (LSHIFT_EXPR,
2986 fold_convert (unsigned_type, rhs),
2987 size_int (lbitpos), 0),
2990 return build (code, compare_type,
2991 build (BIT_AND_EXPR, unsigned_type, lhs, mask),
2995 /* Subroutine for fold_truthop: decode a field reference.
2997 If EXP is a comparison reference, we return the innermost reference.
2999 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
3000 set to the starting bit number.
3002 If the innermost field can be completely contained in a mode-sized
3003 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
3005 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
3006 otherwise it is not changed.
3008 *PUNSIGNEDP is set to the signedness of the field.
3010 *PMASK is set to the mask used. This is either contained in a
3011 BIT_AND_EXPR or derived from the width of the field.
3013 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
3015 Return 0 if this is not a component reference or is one that we can't
3016 do anything with. */
3019 decode_field_reference (tree exp, HOST_WIDE_INT *pbitsize,
3020 HOST_WIDE_INT *pbitpos, enum machine_mode *pmode,
3021 int *punsignedp, int *pvolatilep,
3022 tree *pmask, tree *pand_mask)
3024 tree outer_type = 0;
3026 tree mask, inner, offset;
3028 unsigned int precision;
3030 /* All the optimizations using this function assume integer fields.
3031 There are problems with FP fields since the type_for_size call
3032 below can fail for, e.g., XFmode. */
3033 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
3036 /* We are interested in the bare arrangement of bits, so strip everything
3037 that doesn't affect the machine mode. However, record the type of the
3038 outermost expression if it may matter below. */
3039 if (TREE_CODE (exp) == NOP_EXPR
3040 || TREE_CODE (exp) == CONVERT_EXPR
3041 || TREE_CODE (exp) == NON_LVALUE_EXPR)
3042 outer_type = TREE_TYPE (exp);
3045 if (TREE_CODE (exp) == BIT_AND_EXPR)
3047 and_mask = TREE_OPERAND (exp, 1);
3048 exp = TREE_OPERAND (exp, 0);
3049 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
3050 if (TREE_CODE (and_mask) != INTEGER_CST)
3054 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
3055 punsignedp, pvolatilep);
3056 if ((inner == exp && and_mask == 0)
3057 || *pbitsize < 0 || offset != 0
3058 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
3061 /* If the number of bits in the reference is the same as the bitsize of
3062 the outer type, then the outer type gives the signedness. Otherwise
3063 (in case of a small bitfield) the signedness is unchanged. */
3064 if (outer_type && *pbitsize == tree_low_cst (TYPE_SIZE (outer_type), 1))
3065 *punsignedp = TREE_UNSIGNED (outer_type);
3067 /* Compute the mask to access the bitfield. */
3068 unsigned_type = lang_hooks.types.type_for_size (*pbitsize, 1);
3069 precision = TYPE_PRECISION (unsigned_type);
3071 mask = build_int_2 (~0, ~0);
3072 TREE_TYPE (mask) = unsigned_type;
3073 force_fit_type (mask, 0);
3074 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3075 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3077 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
3079 mask = fold (build (BIT_AND_EXPR, unsigned_type,
3080 fold_convert (unsigned_type, and_mask), mask));
3083 *pand_mask = and_mask;
3087 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
3091 all_ones_mask_p (tree mask, int size)
3093 tree type = TREE_TYPE (mask);
3094 unsigned int precision = TYPE_PRECISION (type);
3097 tmask = build_int_2 (~0, ~0);
3098 TREE_TYPE (tmask) = lang_hooks.types.signed_type (type);
3099 force_fit_type (tmask, 0);
3101 tree_int_cst_equal (mask,
3102 const_binop (RSHIFT_EXPR,
3103 const_binop (LSHIFT_EXPR, tmask,
3104 size_int (precision - size),
3106 size_int (precision - size), 0));
3109 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
3110 represents the sign bit of EXP's type. If EXP represents a sign
3111 or zero extension, also test VAL against the unextended type.
3112 The return value is the (sub)expression whose sign bit is VAL,
3113 or NULL_TREE otherwise. */
3116 sign_bit_p (tree exp, tree val)
3118 unsigned HOST_WIDE_INT mask_lo, lo;
3119 HOST_WIDE_INT mask_hi, hi;
3123 /* Tree EXP must have an integral type. */
3124 t = TREE_TYPE (exp);
3125 if (! INTEGRAL_TYPE_P (t))
3128 /* Tree VAL must be an integer constant. */
3129 if (TREE_CODE (val) != INTEGER_CST
3130 || TREE_CONSTANT_OVERFLOW (val))
3133 width = TYPE_PRECISION (t);
3134 if (width > HOST_BITS_PER_WIDE_INT)
3136 hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1);
3139 mask_hi = ((unsigned HOST_WIDE_INT) -1
3140 >> (2 * HOST_BITS_PER_WIDE_INT - width));
3146 lo = (unsigned HOST_WIDE_INT) 1 << (width - 1);
3149 mask_lo = ((unsigned HOST_WIDE_INT) -1
3150 >> (HOST_BITS_PER_WIDE_INT - width));
3153 /* We mask off those bits beyond TREE_TYPE (exp) so that we can
3154 treat VAL as if it were unsigned. */
3155 if ((TREE_INT_CST_HIGH (val) & mask_hi) == hi
3156 && (TREE_INT_CST_LOW (val) & mask_lo) == lo)
3159 /* Handle extension from a narrower type. */
3160 if (TREE_CODE (exp) == NOP_EXPR
3161 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width)
3162 return sign_bit_p (TREE_OPERAND (exp, 0), val);
3167 /* Subroutine for fold_truthop: determine if an operand is simple enough
3168 to be evaluated unconditionally. */
3171 simple_operand_p (tree exp)
3173 /* Strip any conversions that don't change the machine mode. */
3174 while ((TREE_CODE (exp) == NOP_EXPR
3175 || TREE_CODE (exp) == CONVERT_EXPR)
3176 && (TYPE_MODE (TREE_TYPE (exp))
3177 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)))))
3178 exp = TREE_OPERAND (exp, 0);
3180 return (TREE_CODE_CLASS (TREE_CODE (exp)) == 'c'
3182 && ! TREE_ADDRESSABLE (exp)
3183 && ! TREE_THIS_VOLATILE (exp)
3184 && ! DECL_NONLOCAL (exp)
3185 /* Don't regard global variables as simple. They may be
3186 allocated in ways unknown to the compiler (shared memory,
3187 #pragma weak, etc). */
3188 && ! TREE_PUBLIC (exp)
3189 && ! DECL_EXTERNAL (exp)
3190 /* Loading a static variable is unduly expensive, but global
3191 registers aren't expensive. */
3192 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
3195 /* The following functions are subroutines to fold_range_test and allow it to
3196 try to change a logical combination of comparisons into a range test.
3199 X == 2 || X == 3 || X == 4 || X == 5
3203 (unsigned) (X - 2) <= 3
3205 We describe each set of comparisons as being either inside or outside
3206 a range, using a variable named like IN_P, and then describe the
3207 range with a lower and upper bound. If one of the bounds is omitted,
3208 it represents either the highest or lowest value of the type.
3210 In the comments below, we represent a range by two numbers in brackets
3211 preceded by a "+" to designate being inside that range, or a "-" to
3212 designate being outside that range, so the condition can be inverted by
3213 flipping the prefix. An omitted bound is represented by a "-". For
3214 example, "- [-, 10]" means being outside the range starting at the lowest
3215 possible value and ending at 10, in other words, being greater than 10.
3216 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
3219 We set up things so that the missing bounds are handled in a consistent
3220 manner so neither a missing bound nor "true" and "false" need to be
3221 handled using a special case. */
3223 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
3224 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
3225 and UPPER1_P are nonzero if the respective argument is an upper bound
3226 and zero for a lower. TYPE, if nonzero, is the type of the result; it
3227 must be specified for a comparison. ARG1 will be converted to ARG0's
3228 type if both are specified. */
3231 range_binop (enum tree_code code, tree type, tree arg0, int upper0_p,
3232 tree arg1, int upper1_p)
3238 /* If neither arg represents infinity, do the normal operation.
3239 Else, if not a comparison, return infinity. Else handle the special
3240 comparison rules. Note that most of the cases below won't occur, but
3241 are handled for consistency. */
3243 if (arg0 != 0 && arg1 != 0)
3245 tem = fold (build (code, type != 0 ? type : TREE_TYPE (arg0),
3246 arg0, fold_convert (TREE_TYPE (arg0), arg1)));
3248 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
3251 if (TREE_CODE_CLASS (code) != '<')
3254 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
3255 for neither. In real maths, we cannot assume open ended ranges are
3256 the same. But, this is computer arithmetic, where numbers are finite.
3257 We can therefore make the transformation of any unbounded range with
3258 the value Z, Z being greater than any representable number. This permits
3259 us to treat unbounded ranges as equal. */
3260 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
3261 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
3265 result = sgn0 == sgn1;
3268 result = sgn0 != sgn1;
3271 result = sgn0 < sgn1;
3274 result = sgn0 <= sgn1;
3277 result = sgn0 > sgn1;
3280 result = sgn0 >= sgn1;
3286 return fold_convert (type, result ? integer_one_node : integer_zero_node);
3289 /* Given EXP, a logical expression, set the range it is testing into
3290 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
3291 actually being tested. *PLOW and *PHIGH will be made of the same type
3292 as the returned expression. If EXP is not a comparison, we will most
3293 likely not be returning a useful value and range. */
3296 make_range (tree exp, int *pin_p, tree *plow, tree *phigh)
3298 enum tree_code code;
3299 tree arg0 = NULL_TREE, arg1 = NULL_TREE, type = NULL_TREE;
3300 tree orig_type = NULL_TREE;
3302 tree low, high, n_low, n_high;
3304 /* Start with simply saying "EXP != 0" and then look at the code of EXP
3305 and see if we can refine the range. Some of the cases below may not
3306 happen, but it doesn't seem worth worrying about this. We "continue"
3307 the outer loop when we've changed something; otherwise we "break"
3308 the switch, which will "break" the while. */
3311 low = high = fold_convert (TREE_TYPE (exp), integer_zero_node);
3315 code = TREE_CODE (exp);
3317 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
3319 if (first_rtl_op (code) > 0)
3320 arg0 = TREE_OPERAND (exp, 0);
3321 if (TREE_CODE_CLASS (code) == '<'
3322 || TREE_CODE_CLASS (code) == '1'
3323 || TREE_CODE_CLASS (code) == '2')
3324 type = TREE_TYPE (arg0);
3325 if (TREE_CODE_CLASS (code) == '2'
3326 || TREE_CODE_CLASS (code) == '<'
3327 || (TREE_CODE_CLASS (code) == 'e'
3328 && TREE_CODE_LENGTH (code) > 1))
3329 arg1 = TREE_OPERAND (exp, 1);
3332 /* Set ORIG_TYPE as soon as TYPE is non-null so that we do not
3333 lose a cast by accident. */
3334 if (type != NULL_TREE && orig_type == NULL_TREE)
3339 case TRUTH_NOT_EXPR:
3340 in_p = ! in_p, exp = arg0;
3343 case EQ_EXPR: case NE_EXPR:
3344 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
3345 /* We can only do something if the range is testing for zero
3346 and if the second operand is an integer constant. Note that
3347 saying something is "in" the range we make is done by
3348 complementing IN_P since it will set in the initial case of
3349 being not equal to zero; "out" is leaving it alone. */
3350 if (low == 0 || high == 0
3351 || ! integer_zerop (low) || ! integer_zerop (high)
3352 || TREE_CODE (arg1) != INTEGER_CST)
3357 case NE_EXPR: /* - [c, c] */
3360 case EQ_EXPR: /* + [c, c] */
3361 in_p = ! in_p, low = high = arg1;
3363 case GT_EXPR: /* - [-, c] */
3364 low = 0, high = arg1;
3366 case GE_EXPR: /* + [c, -] */
3367 in_p = ! in_p, low = arg1, high = 0;
3369 case LT_EXPR: /* - [c, -] */
3370 low = arg1, high = 0;
3372 case LE_EXPR: /* + [-, c] */
3373 in_p = ! in_p, low = 0, high = arg1;
3381 /* If this is an unsigned comparison, we also know that EXP is
3382 greater than or equal to zero. We base the range tests we make
3383 on that fact, so we record it here so we can parse existing
3385 if (TREE_UNSIGNED (type) && (low == 0 || high == 0))
3387 if (! merge_ranges (&n_in_p, &n_low, &n_high, in_p, low, high,
3388 1, fold_convert (type, integer_zero_node),
3392 in_p = n_in_p, low = n_low, high = n_high;
3394 /* If the high bound is missing, but we have a nonzero low
3395 bound, reverse the range so it goes from zero to the low bound
3397 if (high == 0 && low && ! integer_zerop (low))
3400 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
3401 integer_one_node, 0);
3402 low = fold_convert (type, integer_zero_node);
3408 /* (-x) IN [a,b] -> x in [-b, -a] */
3409 n_low = range_binop (MINUS_EXPR, type,
3410 fold_convert (type, integer_zero_node),
3412 n_high = range_binop (MINUS_EXPR, type,
3413 fold_convert (type, integer_zero_node),
3415 low = n_low, high = n_high;
3421 exp = build (MINUS_EXPR, type, negate_expr (arg0),
3422 fold_convert (type, integer_one_node));
3425 case PLUS_EXPR: case MINUS_EXPR:
3426 if (TREE_CODE (arg1) != INTEGER_CST)
3429 /* If EXP is signed, any overflow in the computation is undefined,
3430 so we don't worry about it so long as our computations on
3431 the bounds don't overflow. For unsigned, overflow is defined
3432 and this is exactly the right thing. */
3433 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3434 type, low, 0, arg1, 0);
3435 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3436 type, high, 1, arg1, 0);
3437 if ((n_low != 0 && TREE_OVERFLOW (n_low))
3438 || (n_high != 0 && TREE_OVERFLOW (n_high)))
3441 /* Check for an unsigned range which has wrapped around the maximum
3442 value thus making n_high < n_low, and normalize it. */
3443 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
3445 low = range_binop (PLUS_EXPR, type, n_high, 0,
3446 integer_one_node, 0);
3447 high = range_binop (MINUS_EXPR, type, n_low, 0,
3448 integer_one_node, 0);
3450 /* If the range is of the form +/- [ x+1, x ], we won't
3451 be able to normalize it. But then, it represents the
3452 whole range or the empty set, so make it
3454 if (tree_int_cst_equal (n_low, low)
3455 && tree_int_cst_equal (n_high, high))
3461 low = n_low, high = n_high;
3466 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
3467 if (TYPE_PRECISION (type) > TYPE_PRECISION (orig_type))
3470 if (! INTEGRAL_TYPE_P (type)
3471 || (low != 0 && ! int_fits_type_p (low, type))
3472 || (high != 0 && ! int_fits_type_p (high, type)))
3475 n_low = low, n_high = high;
3478 n_low = fold_convert (type, n_low);
3481 n_high = fold_convert (type, n_high);
3483 /* If we're converting from an unsigned to a signed type,
3484 we will be doing the comparison as unsigned. The tests above
3485 have already verified that LOW and HIGH are both positive.
3487 So we have to make sure that the original unsigned value will
3488 be interpreted as positive. */
3489 if (TREE_UNSIGNED (type) && ! TREE_UNSIGNED (TREE_TYPE (exp)))
3491 tree equiv_type = lang_hooks.types.type_for_mode
3492 (TYPE_MODE (type), 1);
3495 /* A range without an upper bound is, naturally, unbounded.
3496 Since convert would have cropped a very large value, use
3497 the max value for the destination type. */
3499 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
3500 : TYPE_MAX_VALUE (type);
3502 if (TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (exp)))
3503 high_positive = fold (build (RSHIFT_EXPR, type,
3507 integer_one_node)));
3509 /* If the low bound is specified, "and" the range with the
3510 range for which the original unsigned value will be
3514 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3515 1, n_low, n_high, 1,
3516 fold_convert (type, integer_zero_node),
3520 in_p = (n_in_p == in_p);
3524 /* Otherwise, "or" the range with the range of the input
3525 that will be interpreted as negative. */
3526 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3527 0, n_low, n_high, 1,
3528 fold_convert (type, integer_zero_node),
3532 in_p = (in_p != n_in_p);
3537 low = n_low, high = n_high;
3547 /* If EXP is a constant, we can evaluate whether this is true or false. */
3548 if (TREE_CODE (exp) == INTEGER_CST)
3550 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
3552 && integer_onep (range_binop (LE_EXPR, integer_type_node,
3558 *pin_p = in_p, *plow = low, *phigh = high;
3562 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3563 type, TYPE, return an expression to test if EXP is in (or out of, depending
3564 on IN_P) the range. */
3567 build_range_check (tree type, tree exp, int in_p, tree low, tree high)
3569 tree etype = TREE_TYPE (exp);
3573 && (0 != (value = build_range_check (type, exp, 1, low, high))))
3574 return invert_truthvalue (value);
3576 if (low == 0 && high == 0)
3577 return fold_convert (type, integer_one_node);
3580 return fold (build (LE_EXPR, type, exp, high));
3583 return fold (build (GE_EXPR, type, exp, low));
3585 if (operand_equal_p (low, high, 0))
3586 return fold (build (EQ_EXPR, type, exp, low));
3588 if (integer_zerop (low))
3590 if (! TREE_UNSIGNED (etype))
3592 etype = lang_hooks.types.unsigned_type (etype);
3593 high = fold_convert (etype, high);
3594 exp = fold_convert (etype, exp);
3596 return build_range_check (type, exp, 1, 0, high);
3599 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
3600 if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST)
3602 unsigned HOST_WIDE_INT lo;
3606 prec = TYPE_PRECISION (etype);
3607 if (prec <= HOST_BITS_PER_WIDE_INT)
3610 lo = ((unsigned HOST_WIDE_INT) 1 << (prec - 1)) - 1;
3614 hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1;
3615 lo = (unsigned HOST_WIDE_INT) -1;
3618 if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo)
3620 if (TREE_UNSIGNED (etype))
3622 etype = lang_hooks.types.signed_type (etype);
3623 exp = fold_convert (etype, exp);
3625 return fold (build (GT_EXPR, type, exp,
3626 fold_convert (etype, integer_zero_node)));
3630 if (0 != (value = const_binop (MINUS_EXPR, high, low, 0))
3631 && ! TREE_OVERFLOW (value))
3632 return build_range_check (type,
3633 fold (build (MINUS_EXPR, etype, exp, low)),
3634 1, fold_convert (etype, integer_zero_node),
3640 /* Given two ranges, see if we can merge them into one. Return 1 if we
3641 can, 0 if we can't. Set the output range into the specified parameters. */
3644 merge_ranges (int *pin_p, tree *plow, tree *phigh, int in0_p, tree low0,
3645 tree high0, int in1_p, tree low1, tree high1)
3653 int lowequal = ((low0 == 0 && low1 == 0)
3654 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3655 low0, 0, low1, 0)));
3656 int highequal = ((high0 == 0 && high1 == 0)
3657 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3658 high0, 1, high1, 1)));
3660 /* Make range 0 be the range that starts first, or ends last if they
3661 start at the same value. Swap them if it isn't. */
3662 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
3665 && integer_onep (range_binop (GT_EXPR, integer_type_node,
3666 high1, 1, high0, 1))))
3668 temp = in0_p, in0_p = in1_p, in1_p = temp;
3669 tem = low0, low0 = low1, low1 = tem;
3670 tem = high0, high0 = high1, high1 = tem;
3673 /* Now flag two cases, whether the ranges are disjoint or whether the
3674 second range is totally subsumed in the first. Note that the tests
3675 below are simplified by the ones above. */
3676 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
3677 high0, 1, low1, 0));
3678 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
3679 high1, 1, high0, 1));
3681 /* We now have four cases, depending on whether we are including or
3682 excluding the two ranges. */
3685 /* If they don't overlap, the result is false. If the second range
3686 is a subset it is the result. Otherwise, the range is from the start
3687 of the second to the end of the first. */
3689 in_p = 0, low = high = 0;
3691 in_p = 1, low = low1, high = high1;
3693 in_p = 1, low = low1, high = high0;
3696 else if (in0_p && ! in1_p)
3698 /* If they don't overlap, the result is the first range. If they are
3699 equal, the result is false. If the second range is a subset of the
3700 first, and the ranges begin at the same place, we go from just after
3701 the end of the first range to the end of the second. If the second
3702 range is not a subset of the first, or if it is a subset and both
3703 ranges end at the same place, the range starts at the start of the
3704 first range and ends just before the second range.
3705 Otherwise, we can't describe this as a single range. */
3707 in_p = 1, low = low0, high = high0;
3708 else if (lowequal && highequal)
3709 in_p = 0, low = high = 0;
3710 else if (subset && lowequal)
3712 in_p = 1, high = high0;
3713 low = range_binop (PLUS_EXPR, NULL_TREE, high1, 0,
3714 integer_one_node, 0);
3716 else if (! subset || highequal)
3718 in_p = 1, low = low0;
3719 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
3720 integer_one_node, 0);
3726 else if (! in0_p && in1_p)
3728 /* If they don't overlap, the result is the second range. If the second
3729 is a subset of the first, the result is false. Otherwise,
3730 the range starts just after the first range and ends at the
3731 end of the second. */
3733 in_p = 1, low = low1, high = high1;
3734 else if (subset || highequal)
3735 in_p = 0, low = high = 0;
3738 in_p = 1, high = high1;
3739 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
3740 integer_one_node, 0);
3746 /* The case where we are excluding both ranges. Here the complex case
3747 is if they don't overlap. In that case, the only time we have a
3748 range is if they are adjacent. If the second is a subset of the
3749 first, the result is the first. Otherwise, the range to exclude
3750 starts at the beginning of the first range and ends at the end of the
3754 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
3755 range_binop (PLUS_EXPR, NULL_TREE,
3757 integer_one_node, 1),
3759 in_p = 0, low = low0, high = high1;
3764 in_p = 0, low = low0, high = high0;
3766 in_p = 0, low = low0, high = high1;
3769 *pin_p = in_p, *plow = low, *phigh = high;
3773 #ifndef RANGE_TEST_NON_SHORT_CIRCUIT
3774 #define RANGE_TEST_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
3777 /* EXP is some logical combination of boolean tests. See if we can
3778 merge it into some range test. Return the new tree if so. */
3781 fold_range_test (tree exp)
3783 int or_op = (TREE_CODE (exp) == TRUTH_ORIF_EXPR
3784 || TREE_CODE (exp) == TRUTH_OR_EXPR);
3785 int in0_p, in1_p, in_p;
3786 tree low0, low1, low, high0, high1, high;
3787 tree lhs = make_range (TREE_OPERAND (exp, 0), &in0_p, &low0, &high0);
3788 tree rhs = make_range (TREE_OPERAND (exp, 1), &in1_p, &low1, &high1);
3791 /* If this is an OR operation, invert both sides; we will invert
3792 again at the end. */
3794 in0_p = ! in0_p, in1_p = ! in1_p;
3796 /* If both expressions are the same, if we can merge the ranges, and we
3797 can build the range test, return it or it inverted. If one of the
3798 ranges is always true or always false, consider it to be the same
3799 expression as the other. */
3800 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
3801 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
3803 && 0 != (tem = (build_range_check (TREE_TYPE (exp),
3805 : rhs != 0 ? rhs : integer_zero_node,
3807 return or_op ? invert_truthvalue (tem) : tem;
3809 /* On machines where the branch cost is expensive, if this is a
3810 short-circuited branch and the underlying object on both sides
3811 is the same, make a non-short-circuit operation. */
3812 else if (RANGE_TEST_NON_SHORT_CIRCUIT
3813 && lhs != 0 && rhs != 0
3814 && (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3815 || TREE_CODE (exp) == TRUTH_ORIF_EXPR)
3816 && operand_equal_p (lhs, rhs, 0))
3818 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
3819 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
3820 which cases we can't do this. */
3821 if (simple_operand_p (lhs))
3822 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3823 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3824 TREE_TYPE (exp), TREE_OPERAND (exp, 0),
3825 TREE_OPERAND (exp, 1));
3827 else if (lang_hooks.decls.global_bindings_p () == 0
3828 && ! CONTAINS_PLACEHOLDER_P (lhs))
3830 tree common = save_expr (lhs);
3832 if (0 != (lhs = build_range_check (TREE_TYPE (exp), common,
3833 or_op ? ! in0_p : in0_p,
3835 && (0 != (rhs = build_range_check (TREE_TYPE (exp), common,
3836 or_op ? ! in1_p : in1_p,
3838 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3839 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3840 TREE_TYPE (exp), lhs, rhs);
3847 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
3848 bit value. Arrange things so the extra bits will be set to zero if and
3849 only if C is signed-extended to its full width. If MASK is nonzero,
3850 it is an INTEGER_CST that should be AND'ed with the extra bits. */
3853 unextend (tree c, int p, int unsignedp, tree mask)
3855 tree type = TREE_TYPE (c);
3856 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
3859 if (p == modesize || unsignedp)
3862 /* We work by getting just the sign bit into the low-order bit, then
3863 into the high-order bit, then sign-extend. We then XOR that value
3865 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
3866 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
3868 /* We must use a signed type in order to get an arithmetic right shift.
3869 However, we must also avoid introducing accidental overflows, so that
3870 a subsequent call to integer_zerop will work. Hence we must
3871 do the type conversion here. At this point, the constant is either
3872 zero or one, and the conversion to a signed type can never overflow.
3873 We could get an overflow if this conversion is done anywhere else. */
3874 if (TREE_UNSIGNED (type))
3875 temp = fold_convert (lang_hooks.types.signed_type (type), temp);
3877 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
3878 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
3880 temp = const_binop (BIT_AND_EXPR, temp,
3881 fold_convert (TREE_TYPE (c), mask), 0);
3882 /* If necessary, convert the type back to match the type of C. */
3883 if (TREE_UNSIGNED (type))
3884 temp = fold_convert (type, temp);
3886 return fold_convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
3889 /* Find ways of folding logical expressions of LHS and RHS:
3890 Try to merge two comparisons to the same innermost item.
3891 Look for range tests like "ch >= '0' && ch <= '9'".
3892 Look for combinations of simple terms on machines with expensive branches
3893 and evaluate the RHS unconditionally.
3895 For example, if we have p->a == 2 && p->b == 4 and we can make an
3896 object large enough to span both A and B, we can do this with a comparison
3897 against the object ANDed with the a mask.
3899 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
3900 operations to do this with one comparison.
3902 We check for both normal comparisons and the BIT_AND_EXPRs made this by
3903 function and the one above.
3905 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
3906 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
3908 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
3911 We return the simplified tree or 0 if no optimization is possible. */
3914 fold_truthop (enum tree_code code, tree truth_type, tree lhs, tree rhs)
3916 /* If this is the "or" of two comparisons, we can do something if
3917 the comparisons are NE_EXPR. If this is the "and", we can do something
3918 if the comparisons are EQ_EXPR. I.e.,
3919 (a->b == 2 && a->c == 4) can become (a->new == NEW).
3921 WANTED_CODE is this operation code. For single bit fields, we can
3922 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
3923 comparison for one-bit fields. */
3925 enum tree_code wanted_code;
3926 enum tree_code lcode, rcode;
3927 tree ll_arg, lr_arg, rl_arg, rr_arg;
3928 tree ll_inner, lr_inner, rl_inner, rr_inner;
3929 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
3930 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
3931 HOST_WIDE_INT xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
3932 HOST_WIDE_INT lnbitsize, lnbitpos, rnbitsize, rnbitpos;
3933 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
3934 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
3935 enum machine_mode lnmode, rnmode;
3936 tree ll_mask, lr_mask, rl_mask, rr_mask;
3937 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
3938 tree l_const, r_const;
3939 tree lntype, rntype, result;
3940 int first_bit, end_bit;
3943 /* Start by getting the comparison codes. Fail if anything is volatile.
3944 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
3945 it were surrounded with a NE_EXPR. */
3947 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
3950 lcode = TREE_CODE (lhs);
3951 rcode = TREE_CODE (rhs);
3953 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
3954 lcode = NE_EXPR, lhs = build (NE_EXPR, truth_type, lhs, integer_zero_node);
3956 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
3957 rcode = NE_EXPR, rhs = build (NE_EXPR, truth_type, rhs, integer_zero_node);
3959 if (TREE_CODE_CLASS (lcode) != '<' || TREE_CODE_CLASS (rcode) != '<')
3962 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
3963 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
3965 ll_arg = TREE_OPERAND (lhs, 0);
3966 lr_arg = TREE_OPERAND (lhs, 1);
3967 rl_arg = TREE_OPERAND (rhs, 0);
3968 rr_arg = TREE_OPERAND (rhs, 1);
3970 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
3971 if (simple_operand_p (ll_arg)
3972 && simple_operand_p (lr_arg)
3973 && !FLOAT_TYPE_P (TREE_TYPE (ll_arg)))
3977 if (operand_equal_p (ll_arg, rl_arg, 0)
3978 && operand_equal_p (lr_arg, rr_arg, 0))
3980 int lcompcode, rcompcode;
3982 lcompcode = comparison_to_compcode (lcode);
3983 rcompcode = comparison_to_compcode (rcode);
3984 compcode = (code == TRUTH_AND_EXPR)
3985 ? lcompcode & rcompcode
3986 : lcompcode | rcompcode;
3988 else if (operand_equal_p (ll_arg, rr_arg, 0)
3989 && operand_equal_p (lr_arg, rl_arg, 0))
3991 int lcompcode, rcompcode;
3993 rcode = swap_tree_comparison (rcode);
3994 lcompcode = comparison_to_compcode (lcode);
3995 rcompcode = comparison_to_compcode (rcode);
3996 compcode = (code == TRUTH_AND_EXPR)
3997 ? lcompcode & rcompcode
3998 : lcompcode | rcompcode;
4003 if (compcode == COMPCODE_TRUE)
4004 return fold_convert (truth_type, integer_one_node);
4005 else if (compcode == COMPCODE_FALSE)
4006 return fold_convert (truth_type, integer_zero_node);
4007 else if (compcode != -1)
4008 return build (compcode_to_comparison (compcode),
4009 truth_type, ll_arg, lr_arg);
4012 /* If the RHS can be evaluated unconditionally and its operands are
4013 simple, it wins to evaluate the RHS unconditionally on machines
4014 with expensive branches. In this case, this isn't a comparison
4015 that can be merged. Avoid doing this if the RHS is a floating-point
4016 comparison since those can trap. */
4018 if (BRANCH_COST >= 2
4019 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
4020 && simple_operand_p (rl_arg)
4021 && simple_operand_p (rr_arg))
4023 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
4024 if (code == TRUTH_OR_EXPR
4025 && lcode == NE_EXPR && integer_zerop (lr_arg)
4026 && rcode == NE_EXPR && integer_zerop (rr_arg)
4027 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
4028 return build (NE_EXPR, truth_type,
4029 build (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
4033 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
4034 if (code == TRUTH_AND_EXPR
4035 && lcode == EQ_EXPR && integer_zerop (lr_arg)
4036 && rcode == EQ_EXPR && integer_zerop (rr_arg)
4037 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
4038 return build (EQ_EXPR, truth_type,
4039 build (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
4043 return build (code, truth_type, lhs, rhs);
4046 /* See if the comparisons can be merged. Then get all the parameters for
4049 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
4050 || (rcode != EQ_EXPR && rcode != NE_EXPR))
4054 ll_inner = decode_field_reference (ll_arg,
4055 &ll_bitsize, &ll_bitpos, &ll_mode,
4056 &ll_unsignedp, &volatilep, &ll_mask,
4058 lr_inner = decode_field_reference (lr_arg,
4059 &lr_bitsize, &lr_bitpos, &lr_mode,
4060 &lr_unsignedp, &volatilep, &lr_mask,
4062 rl_inner = decode_field_reference (rl_arg,
4063 &rl_bitsize, &rl_bitpos, &rl_mode,
4064 &rl_unsignedp, &volatilep, &rl_mask,
4066 rr_inner = decode_field_reference (rr_arg,
4067 &rr_bitsize, &rr_bitpos, &rr_mode,
4068 &rr_unsignedp, &volatilep, &rr_mask,
4071 /* It must be true that the inner operation on the lhs of each
4072 comparison must be the same if we are to be able to do anything.
4073 Then see if we have constants. If not, the same must be true for
4075 if (volatilep || ll_inner == 0 || rl_inner == 0
4076 || ! operand_equal_p (ll_inner, rl_inner, 0))
4079 if (TREE_CODE (lr_arg) == INTEGER_CST
4080 && TREE_CODE (rr_arg) == INTEGER_CST)
4081 l_const = lr_arg, r_const = rr_arg;
4082 else if (lr_inner == 0 || rr_inner == 0
4083 || ! operand_equal_p (lr_inner, rr_inner, 0))
4086 l_const = r_const = 0;
4088 /* If either comparison code is not correct for our logical operation,
4089 fail. However, we can convert a one-bit comparison against zero into
4090 the opposite comparison against that bit being set in the field. */
4092 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
4093 if (lcode != wanted_code)
4095 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
4097 /* Make the left operand unsigned, since we are only interested
4098 in the value of one bit. Otherwise we are doing the wrong
4107 /* This is analogous to the code for l_const above. */
4108 if (rcode != wanted_code)
4110 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
4119 /* After this point all optimizations will generate bit-field
4120 references, which we might not want. */
4121 if (! lang_hooks.can_use_bit_fields_p ())
4124 /* See if we can find a mode that contains both fields being compared on
4125 the left. If we can't, fail. Otherwise, update all constants and masks
4126 to be relative to a field of that size. */
4127 first_bit = MIN (ll_bitpos, rl_bitpos);
4128 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
4129 lnmode = get_best_mode (end_bit - first_bit, first_bit,
4130 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
4132 if (lnmode == VOIDmode)
4135 lnbitsize = GET_MODE_BITSIZE (lnmode);
4136 lnbitpos = first_bit & ~ (lnbitsize - 1);
4137 lntype = lang_hooks.types.type_for_size (lnbitsize, 1);
4138 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
4140 if (BYTES_BIG_ENDIAN)
4142 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
4143 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
4146 ll_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, ll_mask),
4147 size_int (xll_bitpos), 0);
4148 rl_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, rl_mask),
4149 size_int (xrl_bitpos), 0);
4153 l_const = fold_convert (lntype, l_const);
4154 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
4155 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
4156 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
4157 fold (build1 (BIT_NOT_EXPR,
4161 warning ("comparison is always %d", wanted_code == NE_EXPR);
4163 return fold_convert (truth_type,
4164 wanted_code == NE_EXPR
4165 ? integer_one_node : integer_zero_node);
4170 r_const = fold_convert (lntype, r_const);
4171 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
4172 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
4173 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
4174 fold (build1 (BIT_NOT_EXPR,
4178 warning ("comparison is always %d", wanted_code == NE_EXPR);
4180 return fold_convert (truth_type,
4181 wanted_code == NE_EXPR
4182 ? integer_one_node : integer_zero_node);
4186 /* If the right sides are not constant, do the same for it. Also,
4187 disallow this optimization if a size or signedness mismatch occurs
4188 between the left and right sides. */
4191 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
4192 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
4193 /* Make sure the two fields on the right
4194 correspond to the left without being swapped. */
4195 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
4198 first_bit = MIN (lr_bitpos, rr_bitpos);
4199 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
4200 rnmode = get_best_mode (end_bit - first_bit, first_bit,
4201 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
4203 if (rnmode == VOIDmode)
4206 rnbitsize = GET_MODE_BITSIZE (rnmode);
4207 rnbitpos = first_bit & ~ (rnbitsize - 1);
4208 rntype = lang_hooks.types.type_for_size (rnbitsize, 1);
4209 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
4211 if (BYTES_BIG_ENDIAN)
4213 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
4214 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
4217 lr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, lr_mask),
4218 size_int (xlr_bitpos), 0);
4219 rr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, rr_mask),
4220 size_int (xrr_bitpos), 0);
4222 /* Make a mask that corresponds to both fields being compared.
4223 Do this for both items being compared. If the operands are the
4224 same size and the bits being compared are in the same position
4225 then we can do this by masking both and comparing the masked
4227 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4228 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
4229 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
4231 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4232 ll_unsignedp || rl_unsignedp);
4233 if (! all_ones_mask_p (ll_mask, lnbitsize))
4234 lhs = build (BIT_AND_EXPR, lntype, lhs, ll_mask);
4236 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
4237 lr_unsignedp || rr_unsignedp);
4238 if (! all_ones_mask_p (lr_mask, rnbitsize))
4239 rhs = build (BIT_AND_EXPR, rntype, rhs, lr_mask);
4241 return build (wanted_code, truth_type, lhs, rhs);
4244 /* There is still another way we can do something: If both pairs of
4245 fields being compared are adjacent, we may be able to make a wider
4246 field containing them both.
4248 Note that we still must mask the lhs/rhs expressions. Furthermore,
4249 the mask must be shifted to account for the shift done by
4250 make_bit_field_ref. */
4251 if ((ll_bitsize + ll_bitpos == rl_bitpos
4252 && lr_bitsize + lr_bitpos == rr_bitpos)
4253 || (ll_bitpos == rl_bitpos + rl_bitsize
4254 && lr_bitpos == rr_bitpos + rr_bitsize))
4258 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
4259 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
4260 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
4261 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
4263 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
4264 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
4265 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
4266 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
4268 /* Convert to the smaller type before masking out unwanted bits. */
4270 if (lntype != rntype)
4272 if (lnbitsize > rnbitsize)
4274 lhs = fold_convert (rntype, lhs);
4275 ll_mask = fold_convert (rntype, ll_mask);
4278 else if (lnbitsize < rnbitsize)
4280 rhs = fold_convert (lntype, rhs);
4281 lr_mask = fold_convert (lntype, lr_mask);
4286 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
4287 lhs = build (BIT_AND_EXPR, type, lhs, ll_mask);
4289 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
4290 rhs = build (BIT_AND_EXPR, type, rhs, lr_mask);
4292 return build (wanted_code, truth_type, lhs, rhs);
4298 /* Handle the case of comparisons with constants. If there is something in
4299 common between the masks, those bits of the constants must be the same.
4300 If not, the condition is always false. Test for this to avoid generating
4301 incorrect code below. */
4302 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
4303 if (! integer_zerop (result)
4304 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
4305 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
4307 if (wanted_code == NE_EXPR)
4309 warning ("`or' of unmatched not-equal tests is always 1");
4310 return fold_convert (truth_type, integer_one_node);
4314 warning ("`and' of mutually exclusive equal-tests is always 0");
4315 return fold_convert (truth_type, integer_zero_node);
4319 /* Construct the expression we will return. First get the component
4320 reference we will make. Unless the mask is all ones the width of
4321 that field, perform the mask operation. Then compare with the
4323 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4324 ll_unsignedp || rl_unsignedp);
4326 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4327 if (! all_ones_mask_p (ll_mask, lnbitsize))
4328 result = build (BIT_AND_EXPR, lntype, result, ll_mask);
4330 return build (wanted_code, truth_type, result,
4331 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
4334 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
4338 optimize_minmax_comparison (tree t)
4340 tree type = TREE_TYPE (t);
4341 tree arg0 = TREE_OPERAND (t, 0);
4342 enum tree_code op_code;
4343 tree comp_const = TREE_OPERAND (t, 1);
4345 int consts_equal, consts_lt;
4348 STRIP_SIGN_NOPS (arg0);
4350 op_code = TREE_CODE (arg0);
4351 minmax_const = TREE_OPERAND (arg0, 1);
4352 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
4353 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
4354 inner = TREE_OPERAND (arg0, 0);
4356 /* If something does not permit us to optimize, return the original tree. */
4357 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
4358 || TREE_CODE (comp_const) != INTEGER_CST
4359 || TREE_CONSTANT_OVERFLOW (comp_const)
4360 || TREE_CODE (minmax_const) != INTEGER_CST
4361 || TREE_CONSTANT_OVERFLOW (minmax_const))
4364 /* Now handle all the various comparison codes. We only handle EQ_EXPR
4365 and GT_EXPR, doing the rest with recursive calls using logical
4367 switch (TREE_CODE (t))
4369 case NE_EXPR: case LT_EXPR: case LE_EXPR:
4371 invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t)));
4375 fold (build (TRUTH_ORIF_EXPR, type,
4376 optimize_minmax_comparison
4377 (build (EQ_EXPR, type, arg0, comp_const)),
4378 optimize_minmax_comparison
4379 (build (GT_EXPR, type, arg0, comp_const))));
4382 if (op_code == MAX_EXPR && consts_equal)
4383 /* MAX (X, 0) == 0 -> X <= 0 */
4384 return fold (build (LE_EXPR, type, inner, comp_const));
4386 else if (op_code == MAX_EXPR && consts_lt)
4387 /* MAX (X, 0) == 5 -> X == 5 */
4388 return fold (build (EQ_EXPR, type, inner, comp_const));
4390 else if (op_code == MAX_EXPR)
4391 /* MAX (X, 0) == -1 -> false */
4392 return omit_one_operand (type, integer_zero_node, inner);
4394 else if (consts_equal)
4395 /* MIN (X, 0) == 0 -> X >= 0 */
4396 return fold (build (GE_EXPR, type, inner, comp_const));
4399 /* MIN (X, 0) == 5 -> false */
4400 return omit_one_operand (type, integer_zero_node, inner);
4403 /* MIN (X, 0) == -1 -> X == -1 */
4404 return fold (build (EQ_EXPR, type, inner, comp_const));
4407 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
4408 /* MAX (X, 0) > 0 -> X > 0
4409 MAX (X, 0) > 5 -> X > 5 */
4410 return fold (build (GT_EXPR, type, inner, comp_const));
4412 else if (op_code == MAX_EXPR)
4413 /* MAX (X, 0) > -1 -> true */
4414 return omit_one_operand (type, integer_one_node, inner);
4416 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
4417 /* MIN (X, 0) > 0 -> false
4418 MIN (X, 0) > 5 -> false */
4419 return omit_one_operand (type, integer_zero_node, inner);
4422 /* MIN (X, 0) > -1 -> X > -1 */
4423 return fold (build (GT_EXPR, type, inner, comp_const));
4430 /* T is an integer expression that is being multiplied, divided, or taken a
4431 modulus (CODE says which and what kind of divide or modulus) by a
4432 constant C. See if we can eliminate that operation by folding it with
4433 other operations already in T. WIDE_TYPE, if non-null, is a type that
4434 should be used for the computation if wider than our type.
4436 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
4437 (X * 2) + (Y * 4). We must, however, be assured that either the original
4438 expression would not overflow or that overflow is undefined for the type
4439 in the language in question.
4441 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
4442 the machine has a multiply-accumulate insn or that this is part of an
4443 addressing calculation.
4445 If we return a non-null expression, it is an equivalent form of the
4446 original computation, but need not be in the original type. */
4449 extract_muldiv (tree t, tree c, enum tree_code code, tree wide_type)
4451 /* To avoid exponential search depth, refuse to allow recursion past
4452 three levels. Beyond that (1) it's highly unlikely that we'll find
4453 something interesting and (2) we've probably processed it before
4454 when we built the inner expression. */
4463 ret = extract_muldiv_1 (t, c, code, wide_type);
4470 extract_muldiv_1 (tree t, tree c, enum tree_code code, tree wide_type)
4472 tree type = TREE_TYPE (t);
4473 enum tree_code tcode = TREE_CODE (t);
4474 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
4475 > GET_MODE_SIZE (TYPE_MODE (type)))
4476 ? wide_type : type);
4478 int same_p = tcode == code;
4479 tree op0 = NULL_TREE, op1 = NULL_TREE;
4481 /* Don't deal with constants of zero here; they confuse the code below. */
4482 if (integer_zerop (c))
4485 if (TREE_CODE_CLASS (tcode) == '1')
4486 op0 = TREE_OPERAND (t, 0);
4488 if (TREE_CODE_CLASS (tcode) == '2')
4489 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
4491 /* Note that we need not handle conditional operations here since fold
4492 already handles those cases. So just do arithmetic here. */
4496 /* For a constant, we can always simplify if we are a multiply
4497 or (for divide and modulus) if it is a multiple of our constant. */
4498 if (code == MULT_EXPR
4499 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
4500 return const_binop (code, fold_convert (ctype, t),
4501 fold_convert (ctype, c), 0);
4504 case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
4505 /* If op0 is an expression ... */
4506 if ((TREE_CODE_CLASS (TREE_CODE (op0)) == '<'
4507 || TREE_CODE_CLASS (TREE_CODE (op0)) == '1'
4508 || TREE_CODE_CLASS (TREE_CODE (op0)) == '2'
4509 || TREE_CODE_CLASS (TREE_CODE (op0)) == 'e')
4510 /* ... and is unsigned, and its type is smaller than ctype,
4511 then we cannot pass through as widening. */
4512 && ((TREE_UNSIGNED (TREE_TYPE (op0))
4513 && ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
4514 && TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
4515 && (GET_MODE_SIZE (TYPE_MODE (ctype))
4516 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
4517 /* ... or its type is larger than ctype,
4518 then we cannot pass through this truncation. */
4519 || (GET_MODE_SIZE (TYPE_MODE (ctype))
4520 < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0))))
4521 /* ... or signedness changes for division or modulus,
4522 then we cannot pass through this conversion. */
4523 || (code != MULT_EXPR
4524 && (TREE_UNSIGNED (ctype)
4525 != TREE_UNSIGNED (TREE_TYPE (op0))))))
4528 /* Pass the constant down and see if we can make a simplification. If
4529 we can, replace this expression with the inner simplification for
4530 possible later conversion to our or some other type. */
4531 if ((t2 = fold_convert (TREE_TYPE (op0), c)) != 0
4532 && TREE_CODE (t2) == INTEGER_CST
4533 && ! TREE_CONSTANT_OVERFLOW (t2)
4534 && (0 != (t1 = extract_muldiv (op0, t2, code,
4536 ? ctype : NULL_TREE))))
4540 case NEGATE_EXPR: case ABS_EXPR:
4541 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4542 return fold (build1 (tcode, ctype, fold_convert (ctype, t1)));
4545 case MIN_EXPR: case MAX_EXPR:
4546 /* If widening the type changes the signedness, then we can't perform
4547 this optimization as that changes the result. */
4548 if (TREE_UNSIGNED (ctype) != TREE_UNSIGNED (type))
4551 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
4552 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0
4553 && (t2 = extract_muldiv (op1, c, code, wide_type)) != 0)
4555 if (tree_int_cst_sgn (c) < 0)
4556 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
4558 return fold (build (tcode, ctype, fold_convert (ctype, t1),
4559 fold_convert (ctype, t2)));
4563 case WITH_RECORD_EXPR:
4564 if ((t1 = extract_muldiv (TREE_OPERAND (t, 0), c, code, wide_type)) != 0)
4565 return build (WITH_RECORD_EXPR, TREE_TYPE (t1), t1,
4566 TREE_OPERAND (t, 1));
4569 case LSHIFT_EXPR: case RSHIFT_EXPR:
4570 /* If the second operand is constant, this is a multiplication
4571 or floor division, by a power of two, so we can treat it that
4572 way unless the multiplier or divisor overflows. */
4573 if (TREE_CODE (op1) == INTEGER_CST
4574 /* const_binop may not detect overflow correctly,
4575 so check for it explicitly here. */
4576 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
4577 && TREE_INT_CST_HIGH (op1) == 0
4578 && 0 != (t1 = fold_convert (ctype,
4579 const_binop (LSHIFT_EXPR,
4582 && ! TREE_OVERFLOW (t1))
4583 return extract_muldiv (build (tcode == LSHIFT_EXPR
4584 ? MULT_EXPR : FLOOR_DIV_EXPR,
4585 ctype, fold_convert (ctype, op0), t1),
4586 c, code, wide_type);
4589 case PLUS_EXPR: case MINUS_EXPR:
4590 /* See if we can eliminate the operation on both sides. If we can, we
4591 can return a new PLUS or MINUS. If we can't, the only remaining
4592 cases where we can do anything are if the second operand is a
4594 t1 = extract_muldiv (op0, c, code, wide_type);
4595 t2 = extract_muldiv (op1, c, code, wide_type);
4596 if (t1 != 0 && t2 != 0
4597 && (code == MULT_EXPR
4598 /* If not multiplication, we can only do this if both operands
4599 are divisible by c. */
4600 || (multiple_of_p (ctype, op0, c)
4601 && multiple_of_p (ctype, op1, c))))
4602 return fold (build (tcode, ctype, fold_convert (ctype, t1),
4603 fold_convert (ctype, t2)));
4605 /* If this was a subtraction, negate OP1 and set it to be an addition.
4606 This simplifies the logic below. */
4607 if (tcode == MINUS_EXPR)
4608 tcode = PLUS_EXPR, op1 = negate_expr (op1);
4610 if (TREE_CODE (op1) != INTEGER_CST)
4613 /* If either OP1 or C are negative, this optimization is not safe for
4614 some of the division and remainder types while for others we need
4615 to change the code. */
4616 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
4618 if (code == CEIL_DIV_EXPR)
4619 code = FLOOR_DIV_EXPR;
4620 else if (code == FLOOR_DIV_EXPR)
4621 code = CEIL_DIV_EXPR;
4622 else if (code != MULT_EXPR
4623 && code != CEIL_MOD_EXPR && code != FLOOR_MOD_EXPR)
4627 /* If it's a multiply or a division/modulus operation of a multiple
4628 of our constant, do the operation and verify it doesn't overflow. */
4629 if (code == MULT_EXPR
4630 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4632 op1 = const_binop (code, fold_convert (ctype, op1),
4633 fold_convert (ctype, c), 0);
4634 /* We allow the constant to overflow with wrapping semantics. */
4636 || (TREE_OVERFLOW (op1) && ! flag_wrapv))
4642 /* If we have an unsigned type is not a sizetype, we cannot widen
4643 the operation since it will change the result if the original
4644 computation overflowed. */
4645 if (TREE_UNSIGNED (ctype)
4646 && ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
4650 /* If we were able to eliminate our operation from the first side,
4651 apply our operation to the second side and reform the PLUS. */
4652 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
4653 return fold (build (tcode, ctype, fold_convert (ctype, t1), op1));
4655 /* The last case is if we are a multiply. In that case, we can
4656 apply the distributive law to commute the multiply and addition
4657 if the multiplication of the constants doesn't overflow. */
4658 if (code == MULT_EXPR)
4659 return fold (build (tcode, ctype,
4660 fold (build (code, ctype,
4661 fold_convert (ctype, op0),
4662 fold_convert (ctype, c))),
4668 /* We have a special case here if we are doing something like
4669 (C * 8) % 4 since we know that's zero. */
4670 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
4671 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
4672 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
4673 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4674 return omit_one_operand (type, integer_zero_node, op0);
4676 /* ... fall through ... */
4678 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
4679 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
4680 /* If we can extract our operation from the LHS, do so and return a
4681 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
4682 do something only if the second operand is a constant. */
4684 && (t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4685 return fold (build (tcode, ctype, fold_convert (ctype, t1),
4686 fold_convert (ctype, op1)));
4687 else if (tcode == MULT_EXPR && code == MULT_EXPR
4688 && (t1 = extract_muldiv (op1, c, code, wide_type)) != 0)
4689 return fold (build (tcode, ctype, fold_convert (ctype, op0),
4690 fold_convert (ctype, t1)));
4691 else if (TREE_CODE (op1) != INTEGER_CST)
4694 /* If these are the same operation types, we can associate them
4695 assuming no overflow. */
4697 && 0 != (t1 = const_binop (MULT_EXPR, fold_convert (ctype, op1),
4698 fold_convert (ctype, c), 0))
4699 && ! TREE_OVERFLOW (t1))
4700 return fold (build (tcode, ctype, fold_convert (ctype, op0), t1));
4702 /* If these operations "cancel" each other, we have the main
4703 optimizations of this pass, which occur when either constant is a
4704 multiple of the other, in which case we replace this with either an
4705 operation or CODE or TCODE.
4707 If we have an unsigned type that is not a sizetype, we cannot do
4708 this since it will change the result if the original computation
4710 if ((! TREE_UNSIGNED (ctype)
4711 || (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
4713 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
4714 || (tcode == MULT_EXPR
4715 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
4716 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR)))
4718 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4719 return fold (build (tcode, ctype, fold_convert (ctype, op0),
4720 fold_convert (ctype,
4721 const_binop (TRUNC_DIV_EXPR,
4723 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
4724 return fold (build (code, ctype, fold_convert (ctype, op0),
4725 fold_convert (ctype,
4726 const_binop (TRUNC_DIV_EXPR,
4738 /* If T contains a COMPOUND_EXPR which was inserted merely to evaluate
4739 S, a SAVE_EXPR, return the expression actually being evaluated. Note
4740 that we may sometimes modify the tree. */
4743 strip_compound_expr (tree t, tree s)
4745 enum tree_code code = TREE_CODE (t);
4747 /* See if this is the COMPOUND_EXPR we want to eliminate. */
4748 if (code == COMPOUND_EXPR && TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR
4749 && TREE_OPERAND (TREE_OPERAND (t, 0), 0) == s)
4750 return TREE_OPERAND (t, 1);
4752 /* See if this is a COND_EXPR or a simple arithmetic operator. We
4753 don't bother handling any other types. */
4754 else if (code == COND_EXPR)
4756 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4757 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4758 TREE_OPERAND (t, 2) = strip_compound_expr (TREE_OPERAND (t, 2), s);
4760 else if (TREE_CODE_CLASS (code) == '1')
4761 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4762 else if (TREE_CODE_CLASS (code) == '<'
4763 || TREE_CODE_CLASS (code) == '2')
4765 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4766 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4772 /* Return a node which has the indicated constant VALUE (either 0 or
4773 1), and is of the indicated TYPE. */
4776 constant_boolean_node (int value, tree type)
4778 if (type == integer_type_node)
4779 return value ? integer_one_node : integer_zero_node;
4780 else if (TREE_CODE (type) == BOOLEAN_TYPE)
4781 return lang_hooks.truthvalue_conversion (value ? integer_one_node
4782 : integer_zero_node);
4785 tree t = build_int_2 (value, 0);
4787 TREE_TYPE (t) = type;
4792 /* Utility function for the following routine, to see how complex a nesting of
4793 COND_EXPRs can be. EXPR is the expression and LIMIT is a count beyond which
4794 we don't care (to avoid spending too much time on complex expressions.). */
4797 count_cond (tree expr, int lim)
4801 if (TREE_CODE (expr) != COND_EXPR)
4806 ctrue = count_cond (TREE_OPERAND (expr, 1), lim - 1);
4807 cfalse = count_cond (TREE_OPERAND (expr, 2), lim - 1 - ctrue);
4808 return MIN (lim, 1 + ctrue + cfalse);
4811 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
4812 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
4813 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
4814 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
4815 COND is the first argument to CODE; otherwise (as in the example
4816 given here), it is the second argument. TYPE is the type of the
4817 original expression. */
4820 fold_binary_op_with_conditional_arg (enum tree_code code, tree type,
4821 tree cond, tree arg, int cond_first_p)
4823 tree test, true_value, false_value;
4824 tree lhs = NULL_TREE;
4825 tree rhs = NULL_TREE;
4826 /* In the end, we'll produce a COND_EXPR. Both arms of the
4827 conditional expression will be binary operations. The left-hand
4828 side of the expression to be executed if the condition is true
4829 will be pointed to by TRUE_LHS. Similarly, the right-hand side
4830 of the expression to be executed if the condition is true will be
4831 pointed to by TRUE_RHS. FALSE_LHS and FALSE_RHS are analogous --
4832 but apply to the expression to be executed if the conditional is
4838 /* These are the codes to use for the left-hand side and right-hand
4839 side of the COND_EXPR. Normally, they are the same as CODE. */
4840 enum tree_code lhs_code = code;
4841 enum tree_code rhs_code = code;
4842 /* And these are the types of the expressions. */
4843 tree lhs_type = type;
4844 tree rhs_type = type;
4849 true_rhs = false_rhs = &arg;
4850 true_lhs = &true_value;
4851 false_lhs = &false_value;
4855 true_lhs = false_lhs = &arg;
4856 true_rhs = &true_value;
4857 false_rhs = &false_value;
4860 if (TREE_CODE (cond) == COND_EXPR)
4862 test = TREE_OPERAND (cond, 0);
4863 true_value = TREE_OPERAND (cond, 1);
4864 false_value = TREE_OPERAND (cond, 2);
4865 /* If this operand throws an expression, then it does not make
4866 sense to try to perform a logical or arithmetic operation
4867 involving it. Instead of building `a + throw 3' for example,
4868 we simply build `a, throw 3'. */
4869 if (VOID_TYPE_P (TREE_TYPE (true_value)))
4873 lhs_code = COMPOUND_EXPR;
4874 lhs_type = void_type_node;
4879 if (VOID_TYPE_P (TREE_TYPE (false_value)))
4883 rhs_code = COMPOUND_EXPR;
4884 rhs_type = void_type_node;
4892 tree testtype = TREE_TYPE (cond);
4894 true_value = fold_convert (testtype, integer_one_node);
4895 false_value = fold_convert (testtype, integer_zero_node);
4898 /* If ARG is complex we want to make sure we only evaluate it once. Though
4899 this is only required if it is volatile, it might be more efficient even
4900 if it is not. However, if we succeed in folding one part to a constant,
4901 we do not need to make this SAVE_EXPR. Since we do this optimization
4902 primarily to see if we do end up with constant and this SAVE_EXPR
4903 interferes with later optimizations, suppressing it when we can is
4906 If we are not in a function, we can't make a SAVE_EXPR, so don't try to
4907 do so. Don't try to see if the result is a constant if an arm is a
4908 COND_EXPR since we get exponential behavior in that case. */
4910 if (saved_expr_p (arg))
4912 else if (lhs == 0 && rhs == 0
4913 && !TREE_CONSTANT (arg)
4914 && lang_hooks.decls.global_bindings_p () == 0
4915 && ((TREE_CODE (arg) != VAR_DECL && TREE_CODE (arg) != PARM_DECL)
4916 || TREE_SIDE_EFFECTS (arg)))
4918 if (TREE_CODE (true_value) != COND_EXPR)
4919 lhs = fold (build (lhs_code, lhs_type, *true_lhs, *true_rhs));
4921 if (TREE_CODE (false_value) != COND_EXPR)
4922 rhs = fold (build (rhs_code, rhs_type, *false_lhs, *false_rhs));
4924 if ((lhs == 0 || ! TREE_CONSTANT (lhs))
4925 && (rhs == 0 || !TREE_CONSTANT (rhs)))
4927 arg = save_expr (arg);
4929 save = saved_expr_p (arg);
4934 lhs = fold (build (lhs_code, lhs_type, *true_lhs, *true_rhs));
4936 rhs = fold (build (rhs_code, rhs_type, *false_lhs, *false_rhs));
4938 test = fold (build (COND_EXPR, type, test, lhs, rhs));
4940 /* If ARG involves a SAVE_EXPR, we need to ensure it is evaluated
4941 ahead of the COND_EXPR we made. Otherwise we would have it only
4942 evaluated in one branch, with the other branch using the result
4943 but missing the evaluation code. Beware that the save_expr call
4944 above might not return a SAVE_EXPR, so testing the TREE_CODE
4945 of ARG is not enough to decide here. Â */
4947 return build (COMPOUND_EXPR, type,
4948 fold_convert (void_type_node, arg),
4949 strip_compound_expr (test, arg));
4951 return fold_convert (type, test);
4955 /* Subroutine of fold() that checks for the addition of +/- 0.0.
4957 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
4958 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
4959 ADDEND is the same as X.
4961 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
4962 and finite. The problematic cases are when X is zero, and its mode
4963 has signed zeros. In the case of rounding towards -infinity,
4964 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
4965 modes, X + 0 is not the same as X because -0 + 0 is 0. */
4968 fold_real_zero_addition_p (tree type, tree addend, int negate)
4970 if (!real_zerop (addend))
4973 /* Don't allow the fold with -fsignaling-nans. */
4974 if (HONOR_SNANS (TYPE_MODE (type)))
4977 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
4978 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
4981 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
4982 if (TREE_CODE (addend) == REAL_CST
4983 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
4986 /* The mode has signed zeros, and we have to honor their sign.
4987 In this situation, there is only one case we can return true for.
4988 X - 0 is the same as X unless rounding towards -infinity is
4990 return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
4993 /* Subroutine of fold() that checks comparisons of built-in math
4994 functions against real constants.
4996 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
4997 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
4998 is the type of the result and ARG0 and ARG1 are the operands of the
4999 comparison. ARG1 must be a TREE_REAL_CST.
5001 The function returns the constant folded tree if a simplification
5002 can be made, and NULL_TREE otherwise. */
5005 fold_mathfn_compare (enum built_in_function fcode, enum tree_code code,
5006 tree type, tree arg0, tree arg1)
5010 if (BUILTIN_SQRT_P (fcode))
5012 tree arg = TREE_VALUE (TREE_OPERAND (arg0, 1));
5013 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg0));
5015 c = TREE_REAL_CST (arg1);
5016 if (REAL_VALUE_NEGATIVE (c))
5018 /* sqrt(x) < y is always false, if y is negative. */
5019 if (code == EQ_EXPR || code == LT_EXPR || code == LE_EXPR)
5020 return omit_one_operand (type,
5021 fold_convert (type, integer_zero_node),
5024 /* sqrt(x) > y is always true, if y is negative and we
5025 don't care about NaNs, i.e. negative values of x. */
5026 if (code == NE_EXPR || !HONOR_NANS (mode))
5027 return omit_one_operand (type,
5028 fold_convert (type, integer_one_node),
5031 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
5032 return fold (build (GE_EXPR, type, arg,
5033 build_real (TREE_TYPE (arg), dconst0)));
5035 else if (code == GT_EXPR || code == GE_EXPR)
5039 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
5040 real_convert (&c2, mode, &c2);
5042 if (REAL_VALUE_ISINF (c2))
5044 /* sqrt(x) > y is x == +Inf, when y is very large. */
5045 if (HONOR_INFINITIES (mode))
5046 return fold (build (EQ_EXPR, type, arg,
5047 build_real (TREE_TYPE (arg), c2)));
5049 /* sqrt(x) > y is always false, when y is very large
5050 and we don't care about infinities. */
5051 return omit_one_operand (type,
5052 fold_convert (type, integer_zero_node),
5056 /* sqrt(x) > c is the same as x > c*c. */
5057 return fold (build (code, type, arg,
5058 build_real (TREE_TYPE (arg), c2)));
5060 else if (code == LT_EXPR || code == LE_EXPR)
5064 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
5065 real_convert (&c2, mode, &c2);
5067 if (REAL_VALUE_ISINF (c2))
5069 /* sqrt(x) < y is always true, when y is a very large
5070 value and we don't care about NaNs or Infinities. */
5071 if (! HONOR_NANS (mode) && ! HONOR_INFINITIES (mode))
5072 return omit_one_operand (type,
5073 fold_convert (type, integer_one_node),
5076 /* sqrt(x) < y is x != +Inf when y is very large and we
5077 don't care about NaNs. */
5078 if (! HONOR_NANS (mode))
5079 return fold (build (NE_EXPR, type, arg,
5080 build_real (TREE_TYPE (arg), c2)));
5082 /* sqrt(x) < y is x >= 0 when y is very large and we
5083 don't care about Infinities. */
5084 if (! HONOR_INFINITIES (mode))
5085 return fold (build (GE_EXPR, type, arg,
5086 build_real (TREE_TYPE (arg), dconst0)));
5088 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
5089 if (lang_hooks.decls.global_bindings_p () != 0
5090 || CONTAINS_PLACEHOLDER_P (arg))
5093 arg = save_expr (arg);
5094 return fold (build (TRUTH_ANDIF_EXPR, type,
5095 fold (build (GE_EXPR, type, arg,
5096 build_real (TREE_TYPE (arg),
5098 fold (build (NE_EXPR, type, arg,
5099 build_real (TREE_TYPE (arg),
5103 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
5104 if (! HONOR_NANS (mode))
5105 return fold (build (code, type, arg,
5106 build_real (TREE_TYPE (arg), c2)));
5108 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
5109 if (lang_hooks.decls.global_bindings_p () == 0
5110 && ! CONTAINS_PLACEHOLDER_P (arg))
5112 arg = save_expr (arg);
5113 return fold (build (TRUTH_ANDIF_EXPR, type,
5114 fold (build (GE_EXPR, type, arg,
5115 build_real (TREE_TYPE (arg),
5117 fold (build (code, type, arg,
5118 build_real (TREE_TYPE (arg),
5127 /* Subroutine of fold() that optimizes comparisons against Infinities,
5128 either +Inf or -Inf.
5130 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
5131 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
5132 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
5134 The function returns the constant folded tree if a simplification
5135 can be made, and NULL_TREE otherwise. */
5138 fold_inf_compare (enum tree_code code, tree type, tree arg0, tree arg1)
5140 enum machine_mode mode;
5141 REAL_VALUE_TYPE max;
5145 mode = TYPE_MODE (TREE_TYPE (arg0));
5147 /* For negative infinity swap the sense of the comparison. */
5148 neg = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1));
5150 code = swap_tree_comparison (code);
5155 /* x > +Inf is always false, if with ignore sNANs. */
5156 if (HONOR_SNANS (mode))
5158 return omit_one_operand (type,
5159 fold_convert (type, integer_zero_node),
5163 /* x <= +Inf is always true, if we don't case about NaNs. */
5164 if (! HONOR_NANS (mode))
5165 return omit_one_operand (type,
5166 fold_convert (type, integer_one_node),
5169 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
5170 if (lang_hooks.decls.global_bindings_p () == 0
5171 && ! CONTAINS_PLACEHOLDER_P (arg0))
5173 arg0 = save_expr (arg0);
5174 return fold (build (EQ_EXPR, type, arg0, arg0));
5180 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
5181 real_maxval (&max, neg, mode);
5182 return fold (build (neg ? LT_EXPR : GT_EXPR, type,
5183 arg0, build_real (TREE_TYPE (arg0), max)));
5186 /* x < +Inf is always equal to x <= DBL_MAX. */
5187 real_maxval (&max, neg, mode);
5188 return fold (build (neg ? GE_EXPR : LE_EXPR, type,
5189 arg0, build_real (TREE_TYPE (arg0), max)));
5192 /* x != +Inf is always equal to !(x > DBL_MAX). */
5193 real_maxval (&max, neg, mode);
5194 if (! HONOR_NANS (mode))
5195 return fold (build (neg ? GE_EXPR : LE_EXPR, type,
5196 arg0, build_real (TREE_TYPE (arg0), max)));
5197 temp = fold (build (neg ? LT_EXPR : GT_EXPR, type,
5198 arg0, build_real (TREE_TYPE (arg0), max)));
5199 return fold (build1 (TRUTH_NOT_EXPR, type, temp));
5208 /* If CODE with arguments ARG0 and ARG1 represents a single bit
5209 equality/inequality test, then return a simplified form of
5210 the test using shifts and logical operations. Otherwise return
5211 NULL. TYPE is the desired result type. */
5214 fold_single_bit_test (enum tree_code code, tree arg0, tree arg1,
5217 /* If this is a TRUTH_NOT_EXPR, it may have a single bit test inside
5219 if (code == TRUTH_NOT_EXPR)
5221 code = TREE_CODE (arg0);
5222 if (code != NE_EXPR && code != EQ_EXPR)
5225 /* Extract the arguments of the EQ/NE. */
5226 arg1 = TREE_OPERAND (arg0, 1);
5227 arg0 = TREE_OPERAND (arg0, 0);
5229 /* This requires us to invert the code. */
5230 code = (code == EQ_EXPR ? NE_EXPR : EQ_EXPR);
5233 /* If this is testing a single bit, we can optimize the test. */
5234 if ((code == NE_EXPR || code == EQ_EXPR)
5235 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
5236 && integer_pow2p (TREE_OPERAND (arg0, 1)))
5238 tree inner = TREE_OPERAND (arg0, 0);
5239 tree type = TREE_TYPE (arg0);
5240 int bitnum = tree_log2 (TREE_OPERAND (arg0, 1));
5241 enum machine_mode operand_mode = TYPE_MODE (type);
5243 tree signed_type, unsigned_type, intermediate_type;
5246 /* If we have (A & C) != 0 where C is the sign bit of A, convert
5247 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
5248 arg00 = sign_bit_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
5249 if (arg00 != NULL_TREE)
5251 tree stype = lang_hooks.types.signed_type (TREE_TYPE (arg00));
5252 return fold (build (code == EQ_EXPR ? GE_EXPR : LT_EXPR, result_type,
5253 fold_convert (stype, arg00),
5254 fold_convert (stype, integer_zero_node)));
5257 /* At this point, we know that arg0 is not testing the sign bit. */
5258 if (TYPE_PRECISION (type) - 1 == bitnum)
5261 /* Otherwise we have (A & C) != 0 where C is a single bit,
5262 convert that into ((A >> C2) & 1). Where C2 = log2(C).
5263 Similarly for (A & C) == 0. */
5265 /* If INNER is a right shift of a constant and it plus BITNUM does
5266 not overflow, adjust BITNUM and INNER. */
5267 if (TREE_CODE (inner) == RSHIFT_EXPR
5268 && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST
5269 && TREE_INT_CST_HIGH (TREE_OPERAND (inner, 1)) == 0
5270 && bitnum < TYPE_PRECISION (type)
5271 && 0 > compare_tree_int (TREE_OPERAND (inner, 1),
5272 bitnum - TYPE_PRECISION (type)))
5274 bitnum += TREE_INT_CST_LOW (TREE_OPERAND (inner, 1));
5275 inner = TREE_OPERAND (inner, 0);
5278 /* If we are going to be able to omit the AND below, we must do our
5279 operations as unsigned. If we must use the AND, we have a choice.
5280 Normally unsigned is faster, but for some machines signed is. */
5281 #ifdef LOAD_EXTEND_OP
5282 ops_unsigned = (LOAD_EXTEND_OP (operand_mode) == SIGN_EXTEND ? 0 : 1);
5287 signed_type = lang_hooks.types.type_for_mode (operand_mode, 0);
5288 unsigned_type = lang_hooks.types.type_for_mode (operand_mode, 1);
5289 intermediate_type = ops_unsigned ? unsigned_type : signed_type;
5290 inner = fold_convert (intermediate_type, inner);
5293 inner = build (RSHIFT_EXPR, intermediate_type,
5294 inner, size_int (bitnum));
5296 if (code == EQ_EXPR)
5297 inner = build (BIT_XOR_EXPR, intermediate_type,
5298 inner, integer_one_node);
5300 /* Put the AND last so it can combine with more things. */
5301 inner = build (BIT_AND_EXPR, intermediate_type,
5302 inner, integer_one_node);
5304 /* Make sure to return the proper type. */
5305 inner = fold_convert (result_type, inner);
5312 /* Check whether we are allowed to reorder operands arg0 and arg1,
5313 such that the evaluation of arg1 occurs before arg0. */
5316 reorder_operands_p (tree arg0, tree arg1)
5318 if (! flag_evaluation_order)
5320 if (TREE_CONSTANT (arg0) || TREE_CONSTANT (arg1))
5322 return ! TREE_SIDE_EFFECTS (arg0)
5323 && ! TREE_SIDE_EFFECTS (arg1);
5326 /* Test whether it is preferable two swap two operands, ARG0 and
5327 ARG1, for example because ARG0 is an integer constant and ARG1
5328 isn't. If REORDER is true, only recommend swapping if we can
5329 evaluate the operands in reverse order. */
5332 tree_swap_operands_p (tree arg0, tree arg1, bool reorder)
5334 STRIP_SIGN_NOPS (arg0);
5335 STRIP_SIGN_NOPS (arg1);
5337 if (TREE_CODE (arg1) == INTEGER_CST)
5339 if (TREE_CODE (arg0) == INTEGER_CST)
5342 if (TREE_CODE (arg1) == REAL_CST)
5344 if (TREE_CODE (arg0) == REAL_CST)
5347 if (TREE_CODE (arg1) == COMPLEX_CST)
5349 if (TREE_CODE (arg0) == COMPLEX_CST)
5352 if (TREE_CONSTANT (arg1))
5354 if (TREE_CONSTANT (arg0))
5360 if (reorder && flag_evaluation_order
5361 && (TREE_SIDE_EFFECTS (arg0) || TREE_SIDE_EFFECTS (arg1)))
5372 /* Perform constant folding and related simplification of EXPR.
5373 The related simplifications include x*1 => x, x*0 => 0, etc.,
5374 and application of the associative law.
5375 NOP_EXPR conversions may be removed freely (as long as we
5376 are careful not to change the C type of the overall expression)
5377 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
5378 but we can constant-fold them if they have constant operands. */
5380 #ifdef ENABLE_FOLD_CHECKING
5381 # define fold(x) fold_1 (x)
5382 static tree fold_1 (tree);
5388 const tree t = expr;
5389 const tree type = TREE_TYPE (expr);
5390 tree t1 = NULL_TREE;
5392 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
5393 enum tree_code code = TREE_CODE (t);
5394 int kind = TREE_CODE_CLASS (code);
5395 /* WINS will be nonzero when the switch is done
5396 if all operands are constant. */
5399 /* Don't try to process an RTL_EXPR since its operands aren't trees.
5400 Likewise for a SAVE_EXPR that's already been evaluated. */
5401 if (code == RTL_EXPR || (code == SAVE_EXPR && SAVE_EXPR_RTL (t) != 0))
5404 /* Return right away if a constant. */
5408 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
5412 /* Special case for conversion ops that can have fixed point args. */
5413 arg0 = TREE_OPERAND (t, 0);
5415 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
5417 STRIP_SIGN_NOPS (arg0);
5419 if (arg0 != 0 && TREE_CODE (arg0) == COMPLEX_CST)
5420 subop = TREE_REALPART (arg0);
5424 if (subop != 0 && TREE_CODE (subop) != INTEGER_CST
5425 && TREE_CODE (subop) != REAL_CST)
5426 /* Note that TREE_CONSTANT isn't enough:
5427 static var addresses are constant but we can't
5428 do arithmetic on them. */
5431 else if (IS_EXPR_CODE_CLASS (kind))
5433 int len = first_rtl_op (code);
5435 for (i = 0; i < len; i++)
5437 tree op = TREE_OPERAND (t, i);
5441 continue; /* Valid for CALL_EXPR, at least. */
5443 /* Strip any conversions that don't change the mode. This is
5444 safe for every expression, except for a comparison expression
5445 because its signedness is derived from its operands. So, in
5446 the latter case, only strip conversions that don't change the
5449 Note that this is done as an internal manipulation within the
5450 constant folder, in order to find the simplest representation
5451 of the arguments so that their form can be studied. In any
5452 cases, the appropriate type conversions should be put back in
5453 the tree that will get out of the constant folder. */
5455 STRIP_SIGN_NOPS (op);
5459 if (TREE_CODE (op) == COMPLEX_CST)
5460 subop = TREE_REALPART (op);
5464 if (TREE_CODE (subop) != INTEGER_CST
5465 && TREE_CODE (subop) != REAL_CST)
5466 /* Note that TREE_CONSTANT isn't enough:
5467 static var addresses are constant but we can't
5468 do arithmetic on them. */
5478 /* If this is a commutative operation, and ARG0 is a constant, move it
5479 to ARG1 to reduce the number of tests below. */
5480 if (commutative_tree_code (code)
5481 && tree_swap_operands_p (arg0, arg1, true))
5482 return fold (build (code, type, TREE_OPERAND (t, 1),
5483 TREE_OPERAND (t, 0)));
5485 /* Now WINS is set as described above,
5486 ARG0 is the first operand of EXPR,
5487 and ARG1 is the second operand (if it has more than one operand).
5489 First check for cases where an arithmetic operation is applied to a
5490 compound, conditional, or comparison operation. Push the arithmetic
5491 operation inside the compound or conditional to see if any folding
5492 can then be done. Convert comparison to conditional for this purpose.
5493 The also optimizes non-constant cases that used to be done in
5496 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
5497 one of the operands is a comparison and the other is a comparison, a
5498 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
5499 code below would make the expression more complex. Change it to a
5500 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
5501 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
5503 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
5504 || code == EQ_EXPR || code == NE_EXPR)
5505 && ((truth_value_p (TREE_CODE (arg0))
5506 && (truth_value_p (TREE_CODE (arg1))
5507 || (TREE_CODE (arg1) == BIT_AND_EXPR
5508 && integer_onep (TREE_OPERAND (arg1, 1)))))
5509 || (truth_value_p (TREE_CODE (arg1))
5510 && (truth_value_p (TREE_CODE (arg0))
5511 || (TREE_CODE (arg0) == BIT_AND_EXPR
5512 && integer_onep (TREE_OPERAND (arg0, 1)))))))
5514 tem = fold (build (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
5515 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
5519 if (code == EQ_EXPR)
5520 tem = invert_truthvalue (tem);
5525 if (TREE_CODE_CLASS (code) == '1')
5527 if (TREE_CODE (arg0) == COMPOUND_EXPR)
5528 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5529 fold (build1 (code, type, TREE_OPERAND (arg0, 1))));
5530 else if (TREE_CODE (arg0) == COND_EXPR)
5532 tree arg01 = TREE_OPERAND (arg0, 1);
5533 tree arg02 = TREE_OPERAND (arg0, 2);
5534 if (! VOID_TYPE_P (TREE_TYPE (arg01)))
5535 arg01 = fold (build1 (code, type, arg01));
5536 if (! VOID_TYPE_P (TREE_TYPE (arg02)))
5537 arg02 = fold (build1 (code, type, arg02));
5538 tem = fold (build (COND_EXPR, type, TREE_OPERAND (arg0, 0),
5541 /* If this was a conversion, and all we did was to move into
5542 inside the COND_EXPR, bring it back out. But leave it if
5543 it is a conversion from integer to integer and the
5544 result precision is no wider than a word since such a
5545 conversion is cheap and may be optimized away by combine,
5546 while it couldn't if it were outside the COND_EXPR. Then return
5547 so we don't get into an infinite recursion loop taking the
5548 conversion out and then back in. */
5550 if ((code == NOP_EXPR || code == CONVERT_EXPR
5551 || code == NON_LVALUE_EXPR)
5552 && TREE_CODE (tem) == COND_EXPR
5553 && TREE_CODE (TREE_OPERAND (tem, 1)) == code
5554 && TREE_CODE (TREE_OPERAND (tem, 2)) == code
5555 && ! VOID_TYPE_P (TREE_OPERAND (tem, 1))
5556 && ! VOID_TYPE_P (TREE_OPERAND (tem, 2))
5557 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))
5558 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 2), 0)))
5559 && ! (INTEGRAL_TYPE_P (TREE_TYPE (tem))
5561 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))))
5562 && TYPE_PRECISION (TREE_TYPE (tem)) <= BITS_PER_WORD))
5563 tem = build1 (code, type,
5565 TREE_TYPE (TREE_OPERAND
5566 (TREE_OPERAND (tem, 1), 0)),
5567 TREE_OPERAND (tem, 0),
5568 TREE_OPERAND (TREE_OPERAND (tem, 1), 0),
5569 TREE_OPERAND (TREE_OPERAND (tem, 2), 0)));
5572 else if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<')
5573 return fold (build (COND_EXPR, type, arg0,
5574 fold (build1 (code, type, integer_one_node)),
5575 fold (build1 (code, type, integer_zero_node))));
5577 else if (TREE_CODE_CLASS (code) == '<'
5578 && TREE_CODE (arg0) == COMPOUND_EXPR)
5579 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5580 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
5581 else if (TREE_CODE_CLASS (code) == '<'
5582 && TREE_CODE (arg1) == COMPOUND_EXPR)
5583 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
5584 fold (build (code, type, arg0, TREE_OPERAND (arg1, 1))));
5585 else if (TREE_CODE_CLASS (code) == '2'
5586 || TREE_CODE_CLASS (code) == '<')
5588 if (TREE_CODE (arg1) == COMPOUND_EXPR
5589 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg1, 0))
5590 && ! TREE_SIDE_EFFECTS (arg0))
5591 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
5592 fold (build (code, type,
5593 arg0, TREE_OPERAND (arg1, 1))));
5594 else if ((TREE_CODE (arg1) == COND_EXPR
5595 || (TREE_CODE_CLASS (TREE_CODE (arg1)) == '<'
5596 && TREE_CODE_CLASS (code) != '<'))
5597 && (TREE_CODE (arg0) != COND_EXPR
5598 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
5599 && (! TREE_SIDE_EFFECTS (arg0)
5600 || (lang_hooks.decls.global_bindings_p () == 0
5601 && ! CONTAINS_PLACEHOLDER_P (arg0))))
5603 fold_binary_op_with_conditional_arg (code, type, arg1, arg0,
5604 /*cond_first_p=*/0);
5605 else if (TREE_CODE (arg0) == COMPOUND_EXPR)
5606 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5607 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
5608 else if ((TREE_CODE (arg0) == COND_EXPR
5609 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
5610 && TREE_CODE_CLASS (code) != '<'))
5611 && (TREE_CODE (arg1) != COND_EXPR
5612 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
5613 && (! TREE_SIDE_EFFECTS (arg1)
5614 || (lang_hooks.decls.global_bindings_p () == 0
5615 && ! CONTAINS_PLACEHOLDER_P (arg1))))
5617 fold_binary_op_with_conditional_arg (code, type, arg0, arg1,
5618 /*cond_first_p=*/1);
5632 return fold (DECL_INITIAL (t));
5637 case FIX_TRUNC_EXPR:
5639 case FIX_FLOOR_EXPR:
5640 if (TREE_TYPE (TREE_OPERAND (t, 0)) == type)
5641 return TREE_OPERAND (t, 0);
5643 /* Handle cases of two conversions in a row. */
5644 if (TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
5645 || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR)
5647 tree inside_type = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5648 tree inter_type = TREE_TYPE (TREE_OPERAND (t, 0));
5649 int inside_int = INTEGRAL_TYPE_P (inside_type);
5650 int inside_ptr = POINTER_TYPE_P (inside_type);
5651 int inside_float = FLOAT_TYPE_P (inside_type);
5652 unsigned int inside_prec = TYPE_PRECISION (inside_type);
5653 int inside_unsignedp = TREE_UNSIGNED (inside_type);
5654 int inter_int = INTEGRAL_TYPE_P (inter_type);
5655 int inter_ptr = POINTER_TYPE_P (inter_type);
5656 int inter_float = FLOAT_TYPE_P (inter_type);
5657 unsigned int inter_prec = TYPE_PRECISION (inter_type);
5658 int inter_unsignedp = TREE_UNSIGNED (inter_type);
5659 int final_int = INTEGRAL_TYPE_P (type);
5660 int final_ptr = POINTER_TYPE_P (type);
5661 int final_float = FLOAT_TYPE_P (type);
5662 unsigned int final_prec = TYPE_PRECISION (type);
5663 int final_unsignedp = TREE_UNSIGNED (type);
5665 /* In addition to the cases of two conversions in a row
5666 handled below, if we are converting something to its own
5667 type via an object of identical or wider precision, neither
5668 conversion is needed. */
5669 if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (type)
5670 && ((inter_int && final_int) || (inter_float && final_float))
5671 && inter_prec >= final_prec)
5672 return fold (build1 (code, type,
5673 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
5675 /* Likewise, if the intermediate and final types are either both
5676 float or both integer, we don't need the middle conversion if
5677 it is wider than the final type and doesn't change the signedness
5678 (for integers). Avoid this if the final type is a pointer
5679 since then we sometimes need the inner conversion. Likewise if
5680 the outer has a precision not equal to the size of its mode. */
5681 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
5682 || (inter_float && inside_float))
5683 && inter_prec >= inside_prec
5684 && (inter_float || inter_unsignedp == inside_unsignedp)
5685 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
5686 && TYPE_MODE (type) == TYPE_MODE (inter_type))
5688 return fold (build1 (code, type,
5689 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
5691 /* If we have a sign-extension of a zero-extended value, we can
5692 replace that by a single zero-extension. */
5693 if (inside_int && inter_int && final_int
5694 && inside_prec < inter_prec && inter_prec < final_prec
5695 && inside_unsignedp && !inter_unsignedp)
5696 return fold (build1 (code, type,
5697 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
5699 /* Two conversions in a row are not needed unless:
5700 - some conversion is floating-point (overstrict for now), or
5701 - the intermediate type is narrower than both initial and
5703 - the intermediate type and innermost type differ in signedness,
5704 and the outermost type is wider than the intermediate, or
5705 - the initial type is a pointer type and the precisions of the
5706 intermediate and final types differ, or
5707 - the final type is a pointer type and the precisions of the
5708 initial and intermediate types differ. */
5709 if (! inside_float && ! inter_float && ! final_float
5710 && (inter_prec > inside_prec || inter_prec > final_prec)
5711 && ! (inside_int && inter_int
5712 && inter_unsignedp != inside_unsignedp
5713 && inter_prec < final_prec)
5714 && ((inter_unsignedp && inter_prec > inside_prec)
5715 == (final_unsignedp && final_prec > inter_prec))
5716 && ! (inside_ptr && inter_prec != final_prec)
5717 && ! (final_ptr && inside_prec != inter_prec)
5718 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
5719 && TYPE_MODE (type) == TYPE_MODE (inter_type))
5721 return fold (build1 (code, type,
5722 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
5725 if (TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR
5726 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t, 0), 1))
5727 /* Detect assigning a bitfield. */
5728 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) == COMPONENT_REF
5729 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 1))))
5731 /* Don't leave an assignment inside a conversion
5732 unless assigning a bitfield. */
5733 tree prev = TREE_OPERAND (t, 0);
5734 tem = copy_node (t);
5735 TREE_OPERAND (tem, 0) = TREE_OPERAND (prev, 1);
5736 /* First do the assignment, then return converted constant. */
5737 tem = build (COMPOUND_EXPR, TREE_TYPE (tem), prev, fold (tem));
5738 TREE_NO_UNUSED_WARNING (tem) = 1;
5739 TREE_USED (tem) = 1;
5743 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
5744 constants (if x has signed type, the sign bit cannot be set
5745 in c). This folds extension into the BIT_AND_EXPR. */
5746 if (INTEGRAL_TYPE_P (type)
5747 && TREE_CODE (type) != BOOLEAN_TYPE
5748 && TREE_CODE (TREE_OPERAND (t, 0)) == BIT_AND_EXPR
5749 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 1)) == INTEGER_CST)
5751 tree and = TREE_OPERAND (t, 0);
5752 tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
5755 if (TREE_UNSIGNED (TREE_TYPE (and))
5756 || (TYPE_PRECISION (type)
5757 <= TYPE_PRECISION (TREE_TYPE (and))))
5759 else if (TYPE_PRECISION (TREE_TYPE (and1))
5760 <= HOST_BITS_PER_WIDE_INT
5761 && host_integerp (and1, 1))
5763 unsigned HOST_WIDE_INT cst;
5765 cst = tree_low_cst (and1, 1);
5766 cst &= (HOST_WIDE_INT) -1
5767 << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
5768 change = (cst == 0);
5769 #ifdef LOAD_EXTEND_OP
5771 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
5774 tree uns = lang_hooks.types.unsigned_type (TREE_TYPE (and0));
5775 and0 = fold_convert (uns, and0);
5776 and1 = fold_convert (uns, and1);
5781 return fold (build (BIT_AND_EXPR, type,
5782 fold_convert (type, and0),
5783 fold_convert (type, and1)));
5786 tem = fold_convert_const (code, type, arg0);
5787 return tem ? tem : t;
5789 case VIEW_CONVERT_EXPR:
5790 if (TREE_CODE (TREE_OPERAND (t, 0)) == VIEW_CONVERT_EXPR)
5791 return build1 (VIEW_CONVERT_EXPR, type,
5792 TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5796 if (TREE_CODE (arg0) == CONSTRUCTOR
5797 && ! type_contains_placeholder_p (TREE_TYPE (arg0)))
5799 tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0));
5801 return TREE_VALUE (m);
5806 if (TREE_CONSTANT (t) != wins)
5808 tem = copy_node (t);
5809 TREE_CONSTANT (tem) = wins;
5815 if (negate_expr_p (arg0))
5816 return fold_convert (type, negate_expr (arg0));
5821 && (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST))
5822 return fold_abs_const (arg0, type);
5823 else if (TREE_CODE (arg0) == NEGATE_EXPR)
5824 return fold (build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0)));
5825 /* Convert fabs((double)float) into (double)fabsf(float). */
5826 else if (TREE_CODE (arg0) == NOP_EXPR
5827 && TREE_CODE (type) == REAL_TYPE)
5829 tree targ0 = strip_float_extensions (arg0);
5831 return fold_convert (type, fold (build1 (ABS_EXPR,
5835 else if (tree_expr_nonnegative_p (arg0))
5840 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
5841 return fold_convert (type, arg0);
5842 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
5843 return build (COMPLEX_EXPR, type,
5844 TREE_OPERAND (arg0, 0),
5845 negate_expr (TREE_OPERAND (arg0, 1)));
5846 else if (TREE_CODE (arg0) == COMPLEX_CST)
5847 return build_complex (type, TREE_REALPART (arg0),
5848 negate_expr (TREE_IMAGPART (arg0)));
5849 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
5850 return fold (build (TREE_CODE (arg0), type,
5851 fold (build1 (CONJ_EXPR, type,
5852 TREE_OPERAND (arg0, 0))),
5853 fold (build1 (CONJ_EXPR,
5854 type, TREE_OPERAND (arg0, 1)))));
5855 else if (TREE_CODE (arg0) == CONJ_EXPR)
5856 return TREE_OPERAND (arg0, 0);
5862 tem = build_int_2 (~ TREE_INT_CST_LOW (arg0),
5863 ~ TREE_INT_CST_HIGH (arg0));
5864 TREE_TYPE (tem) = type;
5865 force_fit_type (tem, 0);
5866 TREE_OVERFLOW (tem) = TREE_OVERFLOW (arg0);
5867 TREE_CONSTANT_OVERFLOW (tem) = TREE_CONSTANT_OVERFLOW (arg0);
5870 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
5871 return TREE_OPERAND (arg0, 0);
5875 /* A + (-B) -> A - B */
5876 if (TREE_CODE (arg1) == NEGATE_EXPR)
5877 return fold (build (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5878 /* (-A) + B -> B - A */
5879 if (TREE_CODE (arg0) == NEGATE_EXPR)
5880 return fold (build (MINUS_EXPR, type, arg1, TREE_OPERAND (arg0, 0)));
5881 else if (! FLOAT_TYPE_P (type))
5883 if (integer_zerop (arg1))
5884 return non_lvalue (fold_convert (type, arg0));
5886 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
5887 with a constant, and the two constants have no bits in common,
5888 we should treat this as a BIT_IOR_EXPR since this may produce more
5890 if (TREE_CODE (arg0) == BIT_AND_EXPR
5891 && TREE_CODE (arg1) == BIT_AND_EXPR
5892 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5893 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
5894 && integer_zerop (const_binop (BIT_AND_EXPR,
5895 TREE_OPERAND (arg0, 1),
5896 TREE_OPERAND (arg1, 1), 0)))
5898 code = BIT_IOR_EXPR;
5902 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
5903 (plus (plus (mult) (mult)) (foo)) so that we can
5904 take advantage of the factoring cases below. */
5905 if ((TREE_CODE (arg0) == PLUS_EXPR
5906 && TREE_CODE (arg1) == MULT_EXPR)
5907 || (TREE_CODE (arg1) == PLUS_EXPR
5908 && TREE_CODE (arg0) == MULT_EXPR))
5910 tree parg0, parg1, parg, marg;
5912 if (TREE_CODE (arg0) == PLUS_EXPR)
5913 parg = arg0, marg = arg1;
5915 parg = arg1, marg = arg0;
5916 parg0 = TREE_OPERAND (parg, 0);
5917 parg1 = TREE_OPERAND (parg, 1);
5921 if (TREE_CODE (parg0) == MULT_EXPR
5922 && TREE_CODE (parg1) != MULT_EXPR)
5923 return fold (build (PLUS_EXPR, type,
5924 fold (build (PLUS_EXPR, type,
5925 fold_convert (type, parg0),
5926 fold_convert (type, marg))),
5927 fold_convert (type, parg1)));
5928 if (TREE_CODE (parg0) != MULT_EXPR
5929 && TREE_CODE (parg1) == MULT_EXPR)
5930 return fold (build (PLUS_EXPR, type,
5931 fold (build (PLUS_EXPR, type,
5932 fold_convert (type, parg1),
5933 fold_convert (type, marg))),
5934 fold_convert (type, parg0)));
5937 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR)
5939 tree arg00, arg01, arg10, arg11;
5940 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
5942 /* (A * C) + (B * C) -> (A+B) * C.
5943 We are most concerned about the case where C is a constant,
5944 but other combinations show up during loop reduction. Since
5945 it is not difficult, try all four possibilities. */
5947 arg00 = TREE_OPERAND (arg0, 0);
5948 arg01 = TREE_OPERAND (arg0, 1);
5949 arg10 = TREE_OPERAND (arg1, 0);
5950 arg11 = TREE_OPERAND (arg1, 1);
5953 if (operand_equal_p (arg01, arg11, 0))
5954 same = arg01, alt0 = arg00, alt1 = arg10;
5955 else if (operand_equal_p (arg00, arg10, 0))
5956 same = arg00, alt0 = arg01, alt1 = arg11;
5957 else if (operand_equal_p (arg00, arg11, 0))
5958 same = arg00, alt0 = arg01, alt1 = arg10;
5959 else if (operand_equal_p (arg01, arg10, 0))
5960 same = arg01, alt0 = arg00, alt1 = arg11;
5962 /* No identical multiplicands; see if we can find a common
5963 power-of-two factor in non-power-of-two multiplies. This
5964 can help in multi-dimensional array access. */
5965 else if (TREE_CODE (arg01) == INTEGER_CST
5966 && TREE_CODE (arg11) == INTEGER_CST
5967 && TREE_INT_CST_HIGH (arg01) == 0
5968 && TREE_INT_CST_HIGH (arg11) == 0)
5970 HOST_WIDE_INT int01, int11, tmp;
5971 int01 = TREE_INT_CST_LOW (arg01);
5972 int11 = TREE_INT_CST_LOW (arg11);
5974 /* Move min of absolute values to int11. */
5975 if ((int01 >= 0 ? int01 : -int01)
5976 < (int11 >= 0 ? int11 : -int11))
5978 tmp = int01, int01 = int11, int11 = tmp;
5979 alt0 = arg00, arg00 = arg10, arg10 = alt0;
5980 alt0 = arg01, arg01 = arg11, arg11 = alt0;
5983 if (exact_log2 (int11) > 0 && int01 % int11 == 0)
5985 alt0 = fold (build (MULT_EXPR, type, arg00,
5986 build_int_2 (int01 / int11, 0)));
5993 return fold (build (MULT_EXPR, type,
5994 fold (build (PLUS_EXPR, type, alt0, alt1)),
6000 /* See if ARG1 is zero and X + ARG1 reduces to X. */
6001 if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
6002 return non_lvalue (fold_convert (type, arg0));
6004 /* Likewise if the operands are reversed. */
6005 if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
6006 return non_lvalue (fold_convert (type, arg1));
6008 /* Convert x+x into x*2.0. */
6009 if (operand_equal_p (arg0, arg1, 0)
6010 && SCALAR_FLOAT_TYPE_P (type))
6011 return fold (build (MULT_EXPR, type, arg0,
6012 build_real (type, dconst2)));
6014 /* Convert x*c+x into x*(c+1). */
6015 if (flag_unsafe_math_optimizations
6016 && TREE_CODE (arg0) == MULT_EXPR
6017 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
6018 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0, 1))
6019 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
6023 c = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
6024 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
6025 return fold (build (MULT_EXPR, type, arg1,
6026 build_real (type, c)));
6029 /* Convert x+x*c into x*(c+1). */
6030 if (flag_unsafe_math_optimizations
6031 && TREE_CODE (arg1) == MULT_EXPR
6032 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST
6033 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1, 1))
6034 && operand_equal_p (TREE_OPERAND (arg1, 0), arg0, 0))
6038 c = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
6039 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
6040 return fold (build (MULT_EXPR, type, arg0,
6041 build_real (type, c)));
6044 /* Convert x*c1+x*c2 into x*(c1+c2). */
6045 if (flag_unsafe_math_optimizations
6046 && TREE_CODE (arg0) == MULT_EXPR
6047 && TREE_CODE (arg1) == MULT_EXPR
6048 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
6049 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0, 1))
6050 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST
6051 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1, 1))
6052 && operand_equal_p (TREE_OPERAND (arg0, 0),
6053 TREE_OPERAND (arg1, 0), 0))
6055 REAL_VALUE_TYPE c1, c2;
6057 c1 = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
6058 c2 = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
6059 real_arithmetic (&c1, PLUS_EXPR, &c1, &c2);
6060 return fold (build (MULT_EXPR, type,
6061 TREE_OPERAND (arg0, 0),
6062 build_real (type, c1)));
6067 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
6068 is a rotate of A by C1 bits. */
6069 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
6070 is a rotate of A by B bits. */
6072 enum tree_code code0, code1;
6073 code0 = TREE_CODE (arg0);
6074 code1 = TREE_CODE (arg1);
6075 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
6076 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
6077 && operand_equal_p (TREE_OPERAND (arg0, 0),
6078 TREE_OPERAND (arg1, 0), 0)
6079 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
6081 tree tree01, tree11;
6082 enum tree_code code01, code11;
6084 tree01 = TREE_OPERAND (arg0, 1);
6085 tree11 = TREE_OPERAND (arg1, 1);
6086 STRIP_NOPS (tree01);
6087 STRIP_NOPS (tree11);
6088 code01 = TREE_CODE (tree01);
6089 code11 = TREE_CODE (tree11);
6090 if (code01 == INTEGER_CST
6091 && code11 == INTEGER_CST
6092 && TREE_INT_CST_HIGH (tree01) == 0
6093 && TREE_INT_CST_HIGH (tree11) == 0
6094 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
6095 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
6096 return build (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
6097 code0 == LSHIFT_EXPR ? tree01 : tree11);
6098 else if (code11 == MINUS_EXPR)
6100 tree tree110, tree111;
6101 tree110 = TREE_OPERAND (tree11, 0);
6102 tree111 = TREE_OPERAND (tree11, 1);
6103 STRIP_NOPS (tree110);
6104 STRIP_NOPS (tree111);
6105 if (TREE_CODE (tree110) == INTEGER_CST
6106 && 0 == compare_tree_int (tree110,
6108 (TREE_TYPE (TREE_OPERAND
6110 && operand_equal_p (tree01, tree111, 0))
6111 return build ((code0 == LSHIFT_EXPR
6114 type, TREE_OPERAND (arg0, 0), tree01);
6116 else if (code01 == MINUS_EXPR)
6118 tree tree010, tree011;
6119 tree010 = TREE_OPERAND (tree01, 0);
6120 tree011 = TREE_OPERAND (tree01, 1);
6121 STRIP_NOPS (tree010);
6122 STRIP_NOPS (tree011);
6123 if (TREE_CODE (tree010) == INTEGER_CST
6124 && 0 == compare_tree_int (tree010,
6126 (TREE_TYPE (TREE_OPERAND
6128 && operand_equal_p (tree11, tree011, 0))
6129 return build ((code0 != LSHIFT_EXPR
6132 type, TREE_OPERAND (arg0, 0), tree11);
6138 /* In most languages, can't associate operations on floats through
6139 parentheses. Rather than remember where the parentheses were, we
6140 don't associate floats at all, unless the user has specified
6141 -funsafe-math-optimizations. */
6144 && (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
6146 tree var0, con0, lit0, minus_lit0;
6147 tree var1, con1, lit1, minus_lit1;
6149 /* Split both trees into variables, constants, and literals. Then
6150 associate each group together, the constants with literals,
6151 then the result with variables. This increases the chances of
6152 literals being recombined later and of generating relocatable
6153 expressions for the sum of a constant and literal. */
6154 var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
6155 var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
6156 code == MINUS_EXPR);
6158 /* Only do something if we found more than two objects. Otherwise,
6159 nothing has changed and we risk infinite recursion. */
6160 if (2 < ((var0 != 0) + (var1 != 0)
6161 + (con0 != 0) + (con1 != 0)
6162 + (lit0 != 0) + (lit1 != 0)
6163 + (minus_lit0 != 0) + (minus_lit1 != 0)))
6165 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
6166 if (code == MINUS_EXPR)
6169 var0 = associate_trees (var0, var1, code, type);
6170 con0 = associate_trees (con0, con1, code, type);
6171 lit0 = associate_trees (lit0, lit1, code, type);
6172 minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
6174 /* Preserve the MINUS_EXPR if the negative part of the literal is
6175 greater than the positive part. Otherwise, the multiplicative
6176 folding code (i.e extract_muldiv) may be fooled in case
6177 unsigned constants are subtracted, like in the following
6178 example: ((X*2 + 4) - 8U)/2. */
6179 if (minus_lit0 && lit0)
6181 if (TREE_CODE (lit0) == INTEGER_CST
6182 && TREE_CODE (minus_lit0) == INTEGER_CST
6183 && tree_int_cst_lt (lit0, minus_lit0))
6185 minus_lit0 = associate_trees (minus_lit0, lit0,
6191 lit0 = associate_trees (lit0, minus_lit0,
6199 return fold_convert (type,
6200 associate_trees (var0, minus_lit0,
6204 con0 = associate_trees (con0, minus_lit0,
6206 return fold_convert (type,
6207 associate_trees (var0, con0,
6212 con0 = associate_trees (con0, lit0, code, type);
6213 return fold_convert (type, associate_trees (var0, con0,
6220 t1 = const_binop (code, arg0, arg1, 0);
6221 if (t1 != NULL_TREE)
6223 /* The return value should always have
6224 the same type as the original expression. */
6225 if (TREE_TYPE (t1) != type)
6226 t1 = fold_convert (type, t1);
6233 /* A - (-B) -> A + B */
6234 if (TREE_CODE (arg1) == NEGATE_EXPR)
6235 return fold (build (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
6236 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
6237 if (TREE_CODE (arg0) == NEGATE_EXPR
6238 && (FLOAT_TYPE_P (type)
6239 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv))
6240 && negate_expr_p (arg1)
6241 && reorder_operands_p (arg0, arg1))
6242 return fold (build (MINUS_EXPR, type, negate_expr (arg1),
6243 TREE_OPERAND (arg0, 0)));
6245 if (! FLOAT_TYPE_P (type))
6247 if (! wins && integer_zerop (arg0))
6248 return negate_expr (fold_convert (type, arg1));
6249 if (integer_zerop (arg1))
6250 return non_lvalue (fold_convert (type, arg0));
6252 /* Fold A - (A & B) into ~B & A. */
6253 if (!TREE_SIDE_EFFECTS (arg0)
6254 && TREE_CODE (arg1) == BIT_AND_EXPR)
6256 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
6257 return fold (build (BIT_AND_EXPR, type,
6258 fold (build1 (BIT_NOT_EXPR, type,
6259 TREE_OPERAND (arg1, 0))),
6261 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
6262 return fold (build (BIT_AND_EXPR, type,
6263 fold (build1 (BIT_NOT_EXPR, type,
6264 TREE_OPERAND (arg1, 1))),
6268 /* Fold (A & ~B) - (A & B) into (A ^ B) - B, where B is
6269 any power of 2 minus 1. */
6270 if (TREE_CODE (arg0) == BIT_AND_EXPR
6271 && TREE_CODE (arg1) == BIT_AND_EXPR
6272 && operand_equal_p (TREE_OPERAND (arg0, 0),
6273 TREE_OPERAND (arg1, 0), 0))
6275 tree mask0 = TREE_OPERAND (arg0, 1);
6276 tree mask1 = TREE_OPERAND (arg1, 1);
6277 tree tem = fold (build1 (BIT_NOT_EXPR, type, mask0));
6279 if (operand_equal_p (tem, mask1, 0))
6281 tem = fold (build (BIT_XOR_EXPR, type,
6282 TREE_OPERAND (arg0, 0), mask1));
6283 return fold (build (MINUS_EXPR, type, tem, mask1));
6288 /* See if ARG1 is zero and X - ARG1 reduces to X. */
6289 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
6290 return non_lvalue (fold_convert (type, arg0));
6292 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
6293 ARG0 is zero and X + ARG0 reduces to X, since that would mean
6294 (-ARG1 + ARG0) reduces to -ARG1. */
6295 else if (!wins && fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
6296 return negate_expr (fold_convert (type, arg1));
6298 /* Fold &x - &x. This can happen from &x.foo - &x.
6299 This is unsafe for certain floats even in non-IEEE formats.
6300 In IEEE, it is unsafe because it does wrong for NaNs.
6301 Also note that operand_equal_p is always false if an operand
6304 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
6305 && operand_equal_p (arg0, arg1, 0))
6306 return fold_convert (type, integer_zero_node);
6308 /* A - B -> A + (-B) if B is easily negatable. */
6309 if (!wins && negate_expr_p (arg1)
6310 && (FLOAT_TYPE_P (type)
6311 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv)))
6312 return fold (build (PLUS_EXPR, type, arg0, negate_expr (arg1)));
6314 if (TREE_CODE (arg0) == MULT_EXPR
6315 && TREE_CODE (arg1) == MULT_EXPR
6316 && (INTEGRAL_TYPE_P (type) || flag_unsafe_math_optimizations))
6318 /* (A * C) - (B * C) -> (A-B) * C. */
6319 if (operand_equal_p (TREE_OPERAND (arg0, 1),
6320 TREE_OPERAND (arg1, 1), 0))
6321 return fold (build (MULT_EXPR, type,
6322 fold (build (MINUS_EXPR, type,
6323 TREE_OPERAND (arg0, 0),
6324 TREE_OPERAND (arg1, 0))),
6325 TREE_OPERAND (arg0, 1)));
6326 /* (A * C1) - (A * C2) -> A * (C1-C2). */
6327 if (operand_equal_p (TREE_OPERAND (arg0, 0),
6328 TREE_OPERAND (arg1, 0), 0))
6329 return fold (build (MULT_EXPR, type,
6330 TREE_OPERAND (arg0, 0),
6331 fold (build (MINUS_EXPR, type,
6332 TREE_OPERAND (arg0, 1),
6333 TREE_OPERAND (arg1, 1)))));
6339 /* (-A) * (-B) -> A * B */
6340 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
6341 return fold (build (MULT_EXPR, type,
6342 TREE_OPERAND (arg0, 0),
6343 negate_expr (arg1)));
6344 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
6345 return fold (build (MULT_EXPR, type,
6347 TREE_OPERAND (arg1, 0)));
6349 if (! FLOAT_TYPE_P (type))
6351 if (integer_zerop (arg1))
6352 return omit_one_operand (type, arg1, arg0);
6353 if (integer_onep (arg1))
6354 return non_lvalue (fold_convert (type, arg0));
6356 /* (a * (1 << b)) is (a << b) */
6357 if (TREE_CODE (arg1) == LSHIFT_EXPR
6358 && integer_onep (TREE_OPERAND (arg1, 0)))
6359 return fold (build (LSHIFT_EXPR, type, arg0,
6360 TREE_OPERAND (arg1, 1)));
6361 if (TREE_CODE (arg0) == LSHIFT_EXPR
6362 && integer_onep (TREE_OPERAND (arg0, 0)))
6363 return fold (build (LSHIFT_EXPR, type, arg1,
6364 TREE_OPERAND (arg0, 1)));
6366 if (TREE_CODE (arg1) == INTEGER_CST
6367 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0),
6368 fold_convert (type, arg1),
6370 return fold_convert (type, tem);
6375 /* Maybe fold x * 0 to 0. The expressions aren't the same
6376 when x is NaN, since x * 0 is also NaN. Nor are they the
6377 same in modes with signed zeros, since multiplying a
6378 negative value by 0 gives -0, not +0. */
6379 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
6380 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
6381 && real_zerop (arg1))
6382 return omit_one_operand (type, arg1, arg0);
6383 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
6384 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
6385 && real_onep (arg1))
6386 return non_lvalue (fold_convert (type, arg0));
6388 /* Transform x * -1.0 into -x. */
6389 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
6390 && real_minus_onep (arg1))
6391 return fold (build1 (NEGATE_EXPR, type, arg0));
6393 /* Convert (C1/X)*C2 into (C1*C2)/X. */
6394 if (flag_unsafe_math_optimizations
6395 && TREE_CODE (arg0) == RDIV_EXPR
6396 && TREE_CODE (arg1) == REAL_CST
6397 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST)
6399 tree tem = const_binop (MULT_EXPR, TREE_OPERAND (arg0, 0),
6402 return fold (build (RDIV_EXPR, type, tem,
6403 TREE_OPERAND (arg0, 1)));
6406 if (flag_unsafe_math_optimizations)
6408 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
6409 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
6411 /* Optimizations of sqrt(...)*sqrt(...). */
6412 if (fcode0 == fcode1 && BUILTIN_SQRT_P (fcode0))
6414 tree sqrtfn, arg, arglist;
6415 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
6416 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
6418 /* Optimize sqrt(x)*sqrt(x) as x. */
6419 if (operand_equal_p (arg00, arg10, 0)
6420 && ! HONOR_SNANS (TYPE_MODE (type)))
6423 /* Optimize sqrt(x)*sqrt(y) as sqrt(x*y). */
6424 sqrtfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
6425 arg = fold (build (MULT_EXPR, type, arg00, arg10));
6426 arglist = build_tree_list (NULL_TREE, arg);
6427 return build_function_call_expr (sqrtfn, arglist);
6430 /* Optimize expN(x)*expN(y) as expN(x+y). */
6431 if (fcode0 == fcode1 && BUILTIN_EXPONENT_P (fcode0))
6433 tree expfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
6434 tree arg = build (PLUS_EXPR, type,
6435 TREE_VALUE (TREE_OPERAND (arg0, 1)),
6436 TREE_VALUE (TREE_OPERAND (arg1, 1)));
6437 tree arglist = build_tree_list (NULL_TREE, fold (arg));
6438 return build_function_call_expr (expfn, arglist);
6441 /* Optimizations of pow(...)*pow(...). */
6442 if ((fcode0 == BUILT_IN_POW && fcode1 == BUILT_IN_POW)
6443 || (fcode0 == BUILT_IN_POWF && fcode1 == BUILT_IN_POWF)
6444 || (fcode0 == BUILT_IN_POWL && fcode1 == BUILT_IN_POWL))
6446 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
6447 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
6449 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
6450 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
6453 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
6454 if (operand_equal_p (arg01, arg11, 0))
6456 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
6457 tree arg = build (MULT_EXPR, type, arg00, arg10);
6458 tree arglist = tree_cons (NULL_TREE, fold (arg),
6459 build_tree_list (NULL_TREE,
6461 return build_function_call_expr (powfn, arglist);
6464 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
6465 if (operand_equal_p (arg00, arg10, 0))
6467 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
6468 tree arg = fold (build (PLUS_EXPR, type, arg01, arg11));
6469 tree arglist = tree_cons (NULL_TREE, arg00,
6470 build_tree_list (NULL_TREE,
6472 return build_function_call_expr (powfn, arglist);
6476 /* Optimize tan(x)*cos(x) as sin(x). */
6477 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_COS)
6478 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_COSF)
6479 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_COSL)
6480 || (fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_TAN)
6481 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_TANF)
6482 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_TANL))
6483 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
6484 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
6492 sinfn = implicit_built_in_decls[BUILT_IN_SIN];
6496 sinfn = implicit_built_in_decls[BUILT_IN_SINF];
6500 sinfn = implicit_built_in_decls[BUILT_IN_SINL];
6506 if (sinfn != NULL_TREE)
6507 return build_function_call_expr (sinfn,
6508 TREE_OPERAND (arg0, 1));
6511 /* Optimize x*pow(x,c) as pow(x,c+1). */
6512 if (fcode1 == BUILT_IN_POW
6513 || fcode1 == BUILT_IN_POWF
6514 || fcode1 == BUILT_IN_POWL)
6516 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
6517 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
6519 if (TREE_CODE (arg11) == REAL_CST
6520 && ! TREE_CONSTANT_OVERFLOW (arg11)
6521 && operand_equal_p (arg0, arg10, 0))
6523 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
6527 c = TREE_REAL_CST (arg11);
6528 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
6529 arg = build_real (type, c);
6530 arglist = build_tree_list (NULL_TREE, arg);
6531 arglist = tree_cons (NULL_TREE, arg0, arglist);
6532 return build_function_call_expr (powfn, arglist);
6536 /* Optimize pow(x,c)*x as pow(x,c+1). */
6537 if (fcode0 == BUILT_IN_POW
6538 || fcode0 == BUILT_IN_POWF
6539 || fcode0 == BUILT_IN_POWL)
6541 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
6542 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
6544 if (TREE_CODE (arg01) == REAL_CST
6545 && ! TREE_CONSTANT_OVERFLOW (arg01)
6546 && operand_equal_p (arg1, arg00, 0))
6548 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
6552 c = TREE_REAL_CST (arg01);
6553 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
6554 arg = build_real (type, c);
6555 arglist = build_tree_list (NULL_TREE, arg);
6556 arglist = tree_cons (NULL_TREE, arg1, arglist);
6557 return build_function_call_expr (powfn, arglist);
6561 /* Optimize x*x as pow(x,2.0), which is expanded as x*x. */
6563 && operand_equal_p (arg0, arg1, 0))
6567 if (type == double_type_node)
6568 powfn = implicit_built_in_decls[BUILT_IN_POW];
6569 else if (type == float_type_node)
6570 powfn = implicit_built_in_decls[BUILT_IN_POWF];
6571 else if (type == long_double_type_node)
6572 powfn = implicit_built_in_decls[BUILT_IN_POWL];
6578 tree arg = build_real (type, dconst2);
6579 tree arglist = build_tree_list (NULL_TREE, arg);
6580 arglist = tree_cons (NULL_TREE, arg0, arglist);
6581 return build_function_call_expr (powfn, arglist);
6590 if (integer_all_onesp (arg1))
6591 return omit_one_operand (type, arg1, arg0);
6592 if (integer_zerop (arg1))
6593 return non_lvalue (fold_convert (type, arg0));
6594 if (operand_equal_p (arg0, arg1, 0))
6595 return non_lvalue (fold_convert (type, arg0));
6596 t1 = distribute_bit_expr (code, type, arg0, arg1);
6597 if (t1 != NULL_TREE)
6600 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
6602 This results in more efficient code for machines without a NAND
6603 instruction. Combine will canonicalize to the first form
6604 which will allow use of NAND instructions provided by the
6605 backend if they exist. */
6606 if (TREE_CODE (arg0) == BIT_NOT_EXPR
6607 && TREE_CODE (arg1) == BIT_NOT_EXPR)
6609 return fold (build1 (BIT_NOT_EXPR, type,
6610 build (BIT_AND_EXPR, type,
6611 TREE_OPERAND (arg0, 0),
6612 TREE_OPERAND (arg1, 0))));
6615 /* See if this can be simplified into a rotate first. If that
6616 is unsuccessful continue in the association code. */
6620 if (integer_zerop (arg1))
6621 return non_lvalue (fold_convert (type, arg0));
6622 if (integer_all_onesp (arg1))
6623 return fold (build1 (BIT_NOT_EXPR, type, arg0));
6624 if (operand_equal_p (arg0, arg1, 0))
6625 return omit_one_operand (type, integer_zero_node, arg0);
6627 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
6628 with a constant, and the two constants have no bits in common,
6629 we should treat this as a BIT_IOR_EXPR since this may produce more
6631 if (TREE_CODE (arg0) == BIT_AND_EXPR
6632 && TREE_CODE (arg1) == BIT_AND_EXPR
6633 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6634 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
6635 && integer_zerop (const_binop (BIT_AND_EXPR,
6636 TREE_OPERAND (arg0, 1),
6637 TREE_OPERAND (arg1, 1), 0)))
6639 code = BIT_IOR_EXPR;
6643 /* See if this can be simplified into a rotate first. If that
6644 is unsuccessful continue in the association code. */
6648 if (integer_all_onesp (arg1))
6649 return non_lvalue (fold_convert (type, arg0));
6650 if (integer_zerop (arg1))
6651 return omit_one_operand (type, arg1, arg0);
6652 if (operand_equal_p (arg0, arg1, 0))
6653 return non_lvalue (fold_convert (type, arg0));
6654 t1 = distribute_bit_expr (code, type, arg0, arg1);
6655 if (t1 != NULL_TREE)
6657 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
6658 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
6659 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
6662 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
6664 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
6665 && (~TREE_INT_CST_LOW (arg1)
6666 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
6667 return fold_convert (type, TREE_OPERAND (arg0, 0));
6670 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
6672 This results in more efficient code for machines without a NOR
6673 instruction. Combine will canonicalize to the first form
6674 which will allow use of NOR instructions provided by the
6675 backend if they exist. */
6676 if (TREE_CODE (arg0) == BIT_NOT_EXPR
6677 && TREE_CODE (arg1) == BIT_NOT_EXPR)
6679 return fold (build1 (BIT_NOT_EXPR, type,
6680 build (BIT_IOR_EXPR, type,
6681 TREE_OPERAND (arg0, 0),
6682 TREE_OPERAND (arg1, 0))));
6688 /* Don't touch a floating-point divide by zero unless the mode
6689 of the constant can represent infinity. */
6690 if (TREE_CODE (arg1) == REAL_CST
6691 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
6692 && real_zerop (arg1))
6695 /* (-A) / (-B) -> A / B */
6696 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
6697 return fold (build (RDIV_EXPR, type,
6698 TREE_OPERAND (arg0, 0),
6699 negate_expr (arg1)));
6700 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
6701 return fold (build (RDIV_EXPR, type,
6703 TREE_OPERAND (arg1, 0)));
6705 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
6706 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
6707 && real_onep (arg1))
6708 return non_lvalue (fold_convert (type, arg0));
6710 /* In IEEE floating point, x/-1 is not equivalent to -x for snans. */
6711 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
6712 && real_minus_onep (arg1))
6713 return non_lvalue (fold_convert (type, negate_expr (arg0)));
6715 /* If ARG1 is a constant, we can convert this to a multiply by the
6716 reciprocal. This does not have the same rounding properties,
6717 so only do this if -funsafe-math-optimizations. We can actually
6718 always safely do it if ARG1 is a power of two, but it's hard to
6719 tell if it is or not in a portable manner. */
6720 if (TREE_CODE (arg1) == REAL_CST)
6722 if (flag_unsafe_math_optimizations
6723 && 0 != (tem = const_binop (code, build_real (type, dconst1),
6725 return fold (build (MULT_EXPR, type, arg0, tem));
6726 /* Find the reciprocal if optimizing and the result is exact. */
6730 r = TREE_REAL_CST (arg1);
6731 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
6733 tem = build_real (type, r);
6734 return fold (build (MULT_EXPR, type, arg0, tem));
6738 /* Convert A/B/C to A/(B*C). */
6739 if (flag_unsafe_math_optimizations
6740 && TREE_CODE (arg0) == RDIV_EXPR)
6741 return fold (build (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
6742 fold (build (MULT_EXPR, type,
6743 TREE_OPERAND (arg0, 1), arg1))));
6745 /* Convert A/(B/C) to (A/B)*C. */
6746 if (flag_unsafe_math_optimizations
6747 && TREE_CODE (arg1) == RDIV_EXPR)
6748 return fold (build (MULT_EXPR, type,
6749 fold (build (RDIV_EXPR, type, arg0,
6750 TREE_OPERAND (arg1, 0))),
6751 TREE_OPERAND (arg1, 1)));
6753 /* Convert C1/(X*C2) into (C1/C2)/X. */
6754 if (flag_unsafe_math_optimizations
6755 && TREE_CODE (arg1) == MULT_EXPR
6756 && TREE_CODE (arg0) == REAL_CST
6757 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
6759 tree tem = const_binop (RDIV_EXPR, arg0,
6760 TREE_OPERAND (arg1, 1), 0);
6762 return fold (build (RDIV_EXPR, type, tem,
6763 TREE_OPERAND (arg1, 0)));
6766 if (flag_unsafe_math_optimizations)
6768 enum built_in_function fcode = builtin_mathfn_code (arg1);
6769 /* Optimize x/expN(y) into x*expN(-y). */
6770 if (BUILTIN_EXPONENT_P (fcode))
6772 tree expfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
6773 tree arg = build1 (NEGATE_EXPR, type,
6774 TREE_VALUE (TREE_OPERAND (arg1, 1)));
6775 tree arglist = build_tree_list (NULL_TREE, fold (arg));
6776 arg1 = build_function_call_expr (expfn, arglist);
6777 return fold (build (MULT_EXPR, type, arg0, arg1));
6780 /* Optimize x/pow(y,z) into x*pow(y,-z). */
6781 if (fcode == BUILT_IN_POW
6782 || fcode == BUILT_IN_POWF
6783 || fcode == BUILT_IN_POWL)
6785 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
6786 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
6787 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1, 1)));
6788 tree neg11 = fold (build1 (NEGATE_EXPR, type, arg11));
6789 tree arglist = tree_cons(NULL_TREE, arg10,
6790 build_tree_list (NULL_TREE, neg11));
6791 arg1 = build_function_call_expr (powfn, arglist);
6792 return fold (build (MULT_EXPR, type, arg0, arg1));
6796 if (flag_unsafe_math_optimizations)
6798 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
6799 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
6801 /* Optimize sin(x)/cos(x) as tan(x). */
6802 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_COS)
6803 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_COSF)
6804 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_COSL))
6805 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
6806 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
6810 if (fcode0 == BUILT_IN_SIN)
6811 tanfn = implicit_built_in_decls[BUILT_IN_TAN];
6812 else if (fcode0 == BUILT_IN_SINF)
6813 tanfn = implicit_built_in_decls[BUILT_IN_TANF];
6814 else if (fcode0 == BUILT_IN_SINL)
6815 tanfn = implicit_built_in_decls[BUILT_IN_TANL];
6819 if (tanfn != NULL_TREE)
6820 return build_function_call_expr (tanfn,
6821 TREE_OPERAND (arg0, 1));
6824 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
6825 if (((fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_SIN)
6826 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_SINF)
6827 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_SINL))
6828 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
6829 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
6833 if (fcode0 == BUILT_IN_COS)
6834 tanfn = implicit_built_in_decls[BUILT_IN_TAN];
6835 else if (fcode0 == BUILT_IN_COSF)
6836 tanfn = implicit_built_in_decls[BUILT_IN_TANF];
6837 else if (fcode0 == BUILT_IN_COSL)
6838 tanfn = implicit_built_in_decls[BUILT_IN_TANL];
6842 if (tanfn != NULL_TREE)
6844 tree tmp = TREE_OPERAND (arg0, 1);
6845 tmp = build_function_call_expr (tanfn, tmp);
6846 return fold (build (RDIV_EXPR, type,
6847 build_real (type, dconst1),
6852 /* Optimize pow(x,c)/x as pow(x,c-1). */
6853 if (fcode0 == BUILT_IN_POW
6854 || fcode0 == BUILT_IN_POWF
6855 || fcode0 == BUILT_IN_POWL)
6857 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
6858 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0, 1)));
6859 if (TREE_CODE (arg01) == REAL_CST
6860 && ! TREE_CONSTANT_OVERFLOW (arg01)
6861 && operand_equal_p (arg1, arg00, 0))
6863 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
6867 c = TREE_REAL_CST (arg01);
6868 real_arithmetic (&c, MINUS_EXPR, &c, &dconst1);
6869 arg = build_real (type, c);
6870 arglist = build_tree_list (NULL_TREE, arg);
6871 arglist = tree_cons (NULL_TREE, arg1, arglist);
6872 return build_function_call_expr (powfn, arglist);
6878 case TRUNC_DIV_EXPR:
6879 case ROUND_DIV_EXPR:
6880 case FLOOR_DIV_EXPR:
6882 case EXACT_DIV_EXPR:
6883 if (integer_onep (arg1))
6884 return non_lvalue (fold_convert (type, arg0));
6885 if (integer_zerop (arg1))
6888 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
6889 operation, EXACT_DIV_EXPR.
6891 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
6892 At one time others generated faster code, it's not clear if they do
6893 after the last round to changes to the DIV code in expmed.c. */
6894 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
6895 && multiple_of_p (type, arg0, arg1))
6896 return fold (build (EXACT_DIV_EXPR, type, arg0, arg1));
6898 if (TREE_CODE (arg1) == INTEGER_CST
6899 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
6901 return fold_convert (type, tem);
6906 case FLOOR_MOD_EXPR:
6907 case ROUND_MOD_EXPR:
6908 case TRUNC_MOD_EXPR:
6909 if (integer_onep (arg1))
6910 return omit_one_operand (type, integer_zero_node, arg0);
6911 if (integer_zerop (arg1))
6914 if (TREE_CODE (arg1) == INTEGER_CST
6915 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
6917 return fold_convert (type, tem);
6923 if (integer_all_onesp (arg0))
6924 return omit_one_operand (type, arg0, arg1);
6928 /* Optimize -1 >> x for arithmetic right shifts. */
6929 if (integer_all_onesp (arg0) && ! TREE_UNSIGNED (type))
6930 return omit_one_operand (type, arg0, arg1);
6931 /* ... fall through ... */
6935 if (integer_zerop (arg1))
6936 return non_lvalue (fold_convert (type, arg0));
6937 if (integer_zerop (arg0))
6938 return omit_one_operand (type, arg0, arg1);
6940 /* Since negative shift count is not well-defined,
6941 don't try to compute it in the compiler. */
6942 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
6944 /* Rewrite an LROTATE_EXPR by a constant into an
6945 RROTATE_EXPR by a new constant. */
6946 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
6948 tree tem = build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type)), 0);
6949 tem = fold_convert (TREE_TYPE (arg1), tem);
6950 tem = const_binop (MINUS_EXPR, tem, arg1, 0);
6951 return fold (build (RROTATE_EXPR, type, arg0, tem));
6954 /* If we have a rotate of a bit operation with the rotate count and
6955 the second operand of the bit operation both constant,
6956 permute the two operations. */
6957 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
6958 && (TREE_CODE (arg0) == BIT_AND_EXPR
6959 || TREE_CODE (arg0) == BIT_IOR_EXPR
6960 || TREE_CODE (arg0) == BIT_XOR_EXPR)
6961 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
6962 return fold (build (TREE_CODE (arg0), type,
6963 fold (build (code, type,
6964 TREE_OPERAND (arg0, 0), arg1)),
6965 fold (build (code, type,
6966 TREE_OPERAND (arg0, 1), arg1))));
6968 /* Two consecutive rotates adding up to the width of the mode can
6970 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
6971 && TREE_CODE (arg0) == RROTATE_EXPR
6972 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6973 && TREE_INT_CST_HIGH (arg1) == 0
6974 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
6975 && ((TREE_INT_CST_LOW (arg1)
6976 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
6977 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type))))
6978 return TREE_OPERAND (arg0, 0);
6983 if (operand_equal_p (arg0, arg1, 0))
6984 return omit_one_operand (type, arg0, arg1);
6985 if (INTEGRAL_TYPE_P (type)
6986 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), 1))
6987 return omit_one_operand (type, arg1, arg0);
6991 if (operand_equal_p (arg0, arg1, 0))
6992 return omit_one_operand (type, arg0, arg1);
6993 if (INTEGRAL_TYPE_P (type)
6994 && TYPE_MAX_VALUE (type)
6995 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), 1))
6996 return omit_one_operand (type, arg1, arg0);
6999 case TRUTH_NOT_EXPR:
7000 /* Note that the operand of this must be an int
7001 and its values must be 0 or 1.
7002 ("true" is a fixed value perhaps depending on the language,
7003 but we don't handle values other than 1 correctly yet.) */
7004 tem = invert_truthvalue (arg0);
7005 /* Avoid infinite recursion. */
7006 if (TREE_CODE (tem) == TRUTH_NOT_EXPR)
7008 tem = fold_single_bit_test (code, arg0, arg1, type);
7013 return fold_convert (type, tem);
7015 case TRUTH_ANDIF_EXPR:
7016 /* Note that the operands of this must be ints
7017 and their values must be 0 or 1.
7018 ("true" is a fixed value perhaps depending on the language.) */
7019 /* If first arg is constant zero, return it. */
7020 if (integer_zerop (arg0))
7021 return fold_convert (type, arg0);
7022 case TRUTH_AND_EXPR:
7023 /* If either arg is constant true, drop it. */
7024 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
7025 return non_lvalue (fold_convert (type, arg1));
7026 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
7027 /* Preserve sequence points. */
7028 && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
7029 return non_lvalue (fold_convert (type, arg0));
7030 /* If second arg is constant zero, result is zero, but first arg
7031 must be evaluated. */
7032 if (integer_zerop (arg1))
7033 return omit_one_operand (type, arg1, arg0);
7034 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
7035 case will be handled here. */
7036 if (integer_zerop (arg0))
7037 return omit_one_operand (type, arg0, arg1);
7040 /* We only do these simplifications if we are optimizing. */
7044 /* Check for things like (A || B) && (A || C). We can convert this
7045 to A || (B && C). Note that either operator can be any of the four
7046 truth and/or operations and the transformation will still be
7047 valid. Also note that we only care about order for the
7048 ANDIF and ORIF operators. If B contains side effects, this
7049 might change the truth-value of A. */
7050 if (TREE_CODE (arg0) == TREE_CODE (arg1)
7051 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
7052 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
7053 || TREE_CODE (arg0) == TRUTH_AND_EXPR
7054 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
7055 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
7057 tree a00 = TREE_OPERAND (arg0, 0);
7058 tree a01 = TREE_OPERAND (arg0, 1);
7059 tree a10 = TREE_OPERAND (arg1, 0);
7060 tree a11 = TREE_OPERAND (arg1, 1);
7061 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
7062 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
7063 && (code == TRUTH_AND_EXPR
7064 || code == TRUTH_OR_EXPR));
7066 if (operand_equal_p (a00, a10, 0))
7067 return fold (build (TREE_CODE (arg0), type, a00,
7068 fold (build (code, type, a01, a11))));
7069 else if (commutative && operand_equal_p (a00, a11, 0))
7070 return fold (build (TREE_CODE (arg0), type, a00,
7071 fold (build (code, type, a01, a10))));
7072 else if (commutative && operand_equal_p (a01, a10, 0))
7073 return fold (build (TREE_CODE (arg0), type, a01,
7074 fold (build (code, type, a00, a11))));
7076 /* This case if tricky because we must either have commutative
7077 operators or else A10 must not have side-effects. */
7079 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
7080 && operand_equal_p (a01, a11, 0))
7081 return fold (build (TREE_CODE (arg0), type,
7082 fold (build (code, type, a00, a10)),
7086 /* See if we can build a range comparison. */
7087 if (0 != (tem = fold_range_test (t)))
7090 /* Check for the possibility of merging component references. If our
7091 lhs is another similar operation, try to merge its rhs with our
7092 rhs. Then try to merge our lhs and rhs. */
7093 if (TREE_CODE (arg0) == code
7094 && 0 != (tem = fold_truthop (code, type,
7095 TREE_OPERAND (arg0, 1), arg1)))
7096 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
7098 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
7103 case TRUTH_ORIF_EXPR:
7104 /* Note that the operands of this must be ints
7105 and their values must be 0 or true.
7106 ("true" is a fixed value perhaps depending on the language.) */
7107 /* If first arg is constant true, return it. */
7108 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
7109 return fold_convert (type, arg0);
7111 /* If either arg is constant zero, drop it. */
7112 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
7113 return non_lvalue (fold_convert (type, arg1));
7114 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
7115 /* Preserve sequence points. */
7116 && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
7117 return non_lvalue (fold_convert (type, arg0));
7118 /* If second arg is constant true, result is true, but we must
7119 evaluate first arg. */
7120 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
7121 return omit_one_operand (type, arg1, arg0);
7122 /* Likewise for first arg, but note this only occurs here for
7124 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
7125 return omit_one_operand (type, arg0, arg1);
7128 case TRUTH_XOR_EXPR:
7129 /* If either arg is constant zero, drop it. */
7130 if (integer_zerop (arg0))
7131 return non_lvalue (fold_convert (type, arg1));
7132 if (integer_zerop (arg1))
7133 return non_lvalue (fold_convert (type, arg0));
7134 /* If either arg is constant true, this is a logical inversion. */
7135 if (integer_onep (arg0))
7136 return non_lvalue (fold_convert (type, invert_truthvalue (arg1)));
7137 if (integer_onep (arg1))
7138 return non_lvalue (fold_convert (type, invert_truthvalue (arg0)));
7147 /* If one arg is a real or integer constant, put it last. */
7148 if (tree_swap_operands_p (arg0, arg1, true))
7149 return fold (build (swap_tree_comparison (code), type, arg1, arg0));
7151 /* If this is an equality comparison of the address of a non-weak
7152 object against zero, then we know the result. */
7153 if ((code == EQ_EXPR || code == NE_EXPR)
7154 && TREE_CODE (arg0) == ADDR_EXPR
7155 && DECL_P (TREE_OPERAND (arg0, 0))
7156 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
7157 && integer_zerop (arg1))
7159 if (code == EQ_EXPR)
7160 return integer_zero_node;
7162 return integer_one_node;
7165 /* If this is an equality comparison of the address of two non-weak,
7166 unaliased symbols neither of which are extern (since we do not
7167 have access to attributes for externs), then we know the result. */
7168 if ((code == EQ_EXPR || code == NE_EXPR)
7169 && TREE_CODE (arg0) == ADDR_EXPR
7170 && DECL_P (TREE_OPERAND (arg0, 0))
7171 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
7172 && ! lookup_attribute ("alias",
7173 DECL_ATTRIBUTES (TREE_OPERAND (arg0, 0)))
7174 && ! DECL_EXTERNAL (TREE_OPERAND (arg0, 0))
7175 && TREE_CODE (arg1) == ADDR_EXPR
7176 && DECL_P (TREE_OPERAND (arg1, 0))
7177 && ! DECL_WEAK (TREE_OPERAND (arg1, 0))
7178 && ! lookup_attribute ("alias",
7179 DECL_ATTRIBUTES (TREE_OPERAND (arg1, 0)))
7180 && ! DECL_EXTERNAL (TREE_OPERAND (arg1, 0)))
7182 if (code == EQ_EXPR)
7183 return (operand_equal_p (arg0, arg1, 0)
7184 ? integer_one_node : integer_zero_node);
7186 return (operand_equal_p (arg0, arg1, 0)
7187 ? integer_zero_node : integer_one_node);
7190 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
7192 tree targ0 = strip_float_extensions (arg0);
7193 tree targ1 = strip_float_extensions (arg1);
7194 tree newtype = TREE_TYPE (targ0);
7196 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
7197 newtype = TREE_TYPE (targ1);
7199 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
7200 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
7201 return fold (build (code, type, fold_convert (newtype, targ0),
7202 fold_convert (newtype, targ1)));
7204 /* (-a) CMP (-b) -> b CMP a */
7205 if (TREE_CODE (arg0) == NEGATE_EXPR
7206 && TREE_CODE (arg1) == NEGATE_EXPR)
7207 return fold (build (code, type, TREE_OPERAND (arg1, 0),
7208 TREE_OPERAND (arg0, 0)));
7210 if (TREE_CODE (arg1) == REAL_CST)
7212 REAL_VALUE_TYPE cst;
7213 cst = TREE_REAL_CST (arg1);
7215 /* (-a) CMP CST -> a swap(CMP) (-CST) */
7216 if (TREE_CODE (arg0) == NEGATE_EXPR)
7218 fold (build (swap_tree_comparison (code), type,
7219 TREE_OPERAND (arg0, 0),
7220 build_real (TREE_TYPE (arg1),
7221 REAL_VALUE_NEGATE (cst))));
7223 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
7224 /* a CMP (-0) -> a CMP 0 */
7225 if (REAL_VALUE_MINUS_ZERO (cst))
7226 return fold (build (code, type, arg0,
7227 build_real (TREE_TYPE (arg1), dconst0)));
7229 /* x != NaN is always true, other ops are always false. */
7230 if (REAL_VALUE_ISNAN (cst)
7231 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))))
7233 tem = (code == NE_EXPR) ? integer_one_node : integer_zero_node;
7234 return omit_one_operand (type, fold_convert (type, tem), arg0);
7237 /* Fold comparisons against infinity. */
7238 if (REAL_VALUE_ISINF (cst))
7240 tem = fold_inf_compare (code, type, arg0, arg1);
7241 if (tem != NULL_TREE)
7246 /* If this is a comparison of a real constant with a PLUS_EXPR
7247 or a MINUS_EXPR of a real constant, we can convert it into a
7248 comparison with a revised real constant as long as no overflow
7249 occurs when unsafe_math_optimizations are enabled. */
7250 if (flag_unsafe_math_optimizations
7251 && TREE_CODE (arg1) == REAL_CST
7252 && (TREE_CODE (arg0) == PLUS_EXPR
7253 || TREE_CODE (arg0) == MINUS_EXPR)
7254 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
7255 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
7256 ? MINUS_EXPR : PLUS_EXPR,
7257 arg1, TREE_OPERAND (arg0, 1), 0))
7258 && ! TREE_CONSTANT_OVERFLOW (tem))
7259 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
7261 /* Likewise, we can simplify a comparison of a real constant with
7262 a MINUS_EXPR whose first operand is also a real constant, i.e.
7263 (c1 - x) < c2 becomes x > c1-c2. */
7264 if (flag_unsafe_math_optimizations
7265 && TREE_CODE (arg1) == REAL_CST
7266 && TREE_CODE (arg0) == MINUS_EXPR
7267 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST
7268 && 0 != (tem = const_binop (MINUS_EXPR, TREE_OPERAND (arg0, 0),
7270 && ! TREE_CONSTANT_OVERFLOW (tem))
7271 return fold (build (swap_tree_comparison (code), type,
7272 TREE_OPERAND (arg0, 1), tem));
7274 /* Fold comparisons against built-in math functions. */
7275 if (TREE_CODE (arg1) == REAL_CST
7276 && flag_unsafe_math_optimizations
7277 && ! flag_errno_math)
7279 enum built_in_function fcode = builtin_mathfn_code (arg0);
7281 if (fcode != END_BUILTINS)
7283 tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
7284 if (tem != NULL_TREE)
7290 /* Convert foo++ == CONST into ++foo == CONST + INCR. */
7291 if (TREE_CONSTANT (arg1)
7292 && (TREE_CODE (arg0) == POSTINCREMENT_EXPR
7293 || TREE_CODE (arg0) == POSTDECREMENT_EXPR)
7294 /* This optimization is invalid for ordered comparisons
7295 if CONST+INCR overflows or if foo+incr might overflow.
7296 This optimization is invalid for floating point due to rounding.
7297 For pointer types we assume overflow doesn't happen. */
7298 && (POINTER_TYPE_P (TREE_TYPE (arg0))
7299 || (INTEGRAL_TYPE_P (TREE_TYPE (arg0))
7300 && (code == EQ_EXPR || code == NE_EXPR))))
7302 tree varop, newconst;
7304 if (TREE_CODE (arg0) == POSTINCREMENT_EXPR)
7306 newconst = fold (build2 (PLUS_EXPR, TREE_TYPE (arg0),
7307 arg1, TREE_OPERAND (arg0, 1)));
7308 varop = build2 (PREINCREMENT_EXPR, TREE_TYPE (arg0),
7309 TREE_OPERAND (arg0, 0),
7310 TREE_OPERAND (arg0, 1));
7314 newconst = fold (build2 (MINUS_EXPR, TREE_TYPE (arg0),
7315 arg1, TREE_OPERAND (arg0, 1)));
7316 varop = build2 (PREDECREMENT_EXPR, TREE_TYPE (arg0),
7317 TREE_OPERAND (arg0, 0),
7318 TREE_OPERAND (arg0, 1));
7322 /* If VAROP is a reference to a bitfield, we must mask
7323 the constant by the width of the field. */
7324 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
7325 && DECL_BIT_FIELD(TREE_OPERAND (TREE_OPERAND (varop, 0), 1)))
7327 tree fielddecl = TREE_OPERAND (TREE_OPERAND (varop, 0), 1);
7328 int size = TREE_INT_CST_LOW (DECL_SIZE (fielddecl));
7329 tree folded_compare;
7332 /* First check whether the comparison would come out
7333 always the same. If we don't do that we would
7334 change the meaning with the masking. */
7335 folded_compare = fold (build2 (code, type,
7336 TREE_OPERAND (varop, 0),
7338 if (integer_zerop (folded_compare)
7339 || integer_onep (folded_compare))
7340 return omit_one_operand (type, folded_compare, varop);
7342 if (size < HOST_BITS_PER_WIDE_INT)
7344 unsigned HOST_WIDE_INT lo = ((unsigned HOST_WIDE_INT) 1
7346 mask = build_int_2 (lo, 0);
7348 else if (size < 2 * HOST_BITS_PER_WIDE_INT)
7350 HOST_WIDE_INT hi = ((HOST_WIDE_INT) 1
7351 << (size - HOST_BITS_PER_WIDE_INT)) - 1;
7352 mask = build_int_2 (~0, hi);
7357 mask = fold_convert (TREE_TYPE (varop), mask);
7358 newconst = fold (build2 (BIT_AND_EXPR, TREE_TYPE (varop),
7363 return fold (build2 (code, type, varop, newconst));
7366 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
7367 This transformation affects the cases which are handled in later
7368 optimizations involving comparisons with non-negative constants. */
7369 if (TREE_CODE (arg1) == INTEGER_CST
7370 && TREE_CODE (arg0) != INTEGER_CST
7371 && tree_int_cst_sgn (arg1) > 0)
7376 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
7377 return fold (build (GT_EXPR, type, arg0, arg1));
7380 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
7381 return fold (build (LE_EXPR, type, arg0, arg1));
7388 /* Comparisons with the highest or lowest possible integer of
7389 the specified size will have known values. */
7391 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1)));
7393 if (TREE_CODE (arg1) == INTEGER_CST
7394 && ! TREE_CONSTANT_OVERFLOW (arg1)
7395 && width <= HOST_BITS_PER_WIDE_INT
7396 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
7397 || POINTER_TYPE_P (TREE_TYPE (arg1))))
7399 unsigned HOST_WIDE_INT signed_max;
7400 unsigned HOST_WIDE_INT max, min;
7402 signed_max = ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1;
7404 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
7406 max = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
7412 min = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
7415 if (TREE_INT_CST_HIGH (arg1) == 0
7416 && TREE_INT_CST_LOW (arg1) == max)
7420 return omit_one_operand (type,
7425 return fold (build (EQ_EXPR, type, arg0, arg1));
7428 return omit_one_operand (type,
7433 return fold (build (NE_EXPR, type, arg0, arg1));
7435 /* The GE_EXPR and LT_EXPR cases above are not normally
7436 reached because of previous transformations. */
7441 else if (TREE_INT_CST_HIGH (arg1) == 0
7442 && TREE_INT_CST_LOW (arg1) == max - 1)
7446 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
7447 return fold (build (EQ_EXPR, type, arg0, arg1));
7449 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
7450 return fold (build (NE_EXPR, type, arg0, arg1));
7454 else if (TREE_INT_CST_HIGH (arg1) == (min ? -1 : 0)
7455 && TREE_INT_CST_LOW (arg1) == min)
7459 return omit_one_operand (type,
7464 return fold (build (EQ_EXPR, type, arg0, arg1));
7467 return omit_one_operand (type,
7472 return fold (build (NE_EXPR, type, arg0, arg1));
7477 else if (TREE_INT_CST_HIGH (arg1) == (min ? -1 : 0)
7478 && TREE_INT_CST_LOW (arg1) == min + 1)
7482 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
7483 return fold (build (NE_EXPR, type, arg0, arg1));
7485 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
7486 return fold (build (EQ_EXPR, type, arg0, arg1));
7491 else if (TREE_INT_CST_HIGH (arg1) == 0
7492 && TREE_INT_CST_LOW (arg1) == signed_max
7493 && TREE_UNSIGNED (TREE_TYPE (arg1))
7494 /* signed_type does not work on pointer types. */
7495 && INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
7497 /* The following case also applies to X < signed_max+1
7498 and X >= signed_max+1 because previous transformations. */
7499 if (code == LE_EXPR || code == GT_EXPR)
7502 st0 = lang_hooks.types.signed_type (TREE_TYPE (arg0));
7503 st1 = lang_hooks.types.signed_type (TREE_TYPE (arg1));
7505 (build (code == LE_EXPR ? GE_EXPR: LT_EXPR,
7506 type, fold_convert (st0, arg0),
7507 fold_convert (st1, integer_zero_node)));
7513 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
7514 a MINUS_EXPR of a constant, we can convert it into a comparison with
7515 a revised constant as long as no overflow occurs. */
7516 if ((code == EQ_EXPR || code == NE_EXPR)
7517 && TREE_CODE (arg1) == INTEGER_CST
7518 && (TREE_CODE (arg0) == PLUS_EXPR
7519 || TREE_CODE (arg0) == MINUS_EXPR)
7520 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7521 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
7522 ? MINUS_EXPR : PLUS_EXPR,
7523 arg1, TREE_OPERAND (arg0, 1), 0))
7524 && ! TREE_CONSTANT_OVERFLOW (tem))
7525 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
7527 /* Similarly for a NEGATE_EXPR. */
7528 else if ((code == EQ_EXPR || code == NE_EXPR)
7529 && TREE_CODE (arg0) == NEGATE_EXPR
7530 && TREE_CODE (arg1) == INTEGER_CST
7531 && 0 != (tem = negate_expr (arg1))
7532 && TREE_CODE (tem) == INTEGER_CST
7533 && ! TREE_CONSTANT_OVERFLOW (tem))
7534 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
7536 /* If we have X - Y == 0, we can convert that to X == Y and similarly
7537 for !=. Don't do this for ordered comparisons due to overflow. */
7538 else if ((code == NE_EXPR || code == EQ_EXPR)
7539 && integer_zerop (arg1) && TREE_CODE (arg0) == MINUS_EXPR)
7540 return fold (build (code, type,
7541 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1)));
7543 /* If we are widening one operand of an integer comparison,
7544 see if the other operand is similarly being widened. Perhaps we
7545 can do the comparison in the narrower type. */
7546 else if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
7547 && TREE_CODE (arg0) == NOP_EXPR
7548 && (tem = get_unwidened (arg0, NULL_TREE)) != arg0
7549 && (t1 = get_unwidened (arg1, TREE_TYPE (tem))) != 0
7550 && (TREE_TYPE (t1) == TREE_TYPE (tem)
7551 || (TREE_CODE (t1) == INTEGER_CST
7552 && int_fits_type_p (t1, TREE_TYPE (tem)))))
7553 return fold (build (code, type, tem,
7554 fold_convert (TREE_TYPE (tem), t1)));
7556 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
7557 constant, we can simplify it. */
7558 else if (TREE_CODE (arg1) == INTEGER_CST
7559 && (TREE_CODE (arg0) == MIN_EXPR
7560 || TREE_CODE (arg0) == MAX_EXPR)
7561 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
7562 return optimize_minmax_comparison (t);
7564 /* If we are comparing an ABS_EXPR with a constant, we can
7565 convert all the cases into explicit comparisons, but they may
7566 well not be faster than doing the ABS and one comparison.
7567 But ABS (X) <= C is a range comparison, which becomes a subtraction
7568 and a comparison, and is probably faster. */
7569 else if (code == LE_EXPR && TREE_CODE (arg1) == INTEGER_CST
7570 && TREE_CODE (arg0) == ABS_EXPR
7571 && ! TREE_SIDE_EFFECTS (arg0)
7572 && (0 != (tem = negate_expr (arg1)))
7573 && TREE_CODE (tem) == INTEGER_CST
7574 && ! TREE_CONSTANT_OVERFLOW (tem))
7575 return fold (build (TRUTH_ANDIF_EXPR, type,
7576 build (GE_EXPR, type, TREE_OPERAND (arg0, 0), tem),
7577 build (LE_EXPR, type,
7578 TREE_OPERAND (arg0, 0), arg1)));
7580 /* If this is an EQ or NE comparison with zero and ARG0 is
7581 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
7582 two operations, but the latter can be done in one less insn
7583 on machines that have only two-operand insns or on which a
7584 constant cannot be the first operand. */
7585 if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR)
7586 && TREE_CODE (arg0) == BIT_AND_EXPR)
7588 if (TREE_CODE (TREE_OPERAND (arg0, 0)) == LSHIFT_EXPR
7589 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 0), 0)))
7591 fold (build (code, type,
7592 build (BIT_AND_EXPR, TREE_TYPE (arg0),
7594 TREE_TYPE (TREE_OPERAND (arg0, 0)),
7595 TREE_OPERAND (arg0, 1),
7596 TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)),
7597 fold_convert (TREE_TYPE (arg0),
7600 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
7601 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
7603 fold (build (code, type,
7604 build (BIT_AND_EXPR, TREE_TYPE (arg0),
7606 TREE_TYPE (TREE_OPERAND (arg0, 1)),
7607 TREE_OPERAND (arg0, 0),
7608 TREE_OPERAND (TREE_OPERAND (arg0, 1), 1)),
7609 fold_convert (TREE_TYPE (arg0),
7614 /* If this is an NE or EQ comparison of zero against the result of a
7615 signed MOD operation whose second operand is a power of 2, make
7616 the MOD operation unsigned since it is simpler and equivalent. */
7617 if ((code == NE_EXPR || code == EQ_EXPR)
7618 && integer_zerop (arg1)
7619 && ! TREE_UNSIGNED (TREE_TYPE (arg0))
7620 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
7621 || TREE_CODE (arg0) == CEIL_MOD_EXPR
7622 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
7623 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
7624 && integer_pow2p (TREE_OPERAND (arg0, 1)))
7626 tree newtype = lang_hooks.types.unsigned_type (TREE_TYPE (arg0));
7627 tree newmod = build (TREE_CODE (arg0), newtype,
7628 fold_convert (newtype,
7629 TREE_OPERAND (arg0, 0)),
7630 fold_convert (newtype,
7631 TREE_OPERAND (arg0, 1)));
7633 return build (code, type, newmod, fold_convert (newtype, arg1));
7636 /* If this is an NE comparison of zero with an AND of one, remove the
7637 comparison since the AND will give the correct value. */
7638 if (code == NE_EXPR && integer_zerop (arg1)
7639 && TREE_CODE (arg0) == BIT_AND_EXPR
7640 && integer_onep (TREE_OPERAND (arg0, 1)))
7641 return fold_convert (type, arg0);
7643 /* If we have (A & C) == C where C is a power of 2, convert this into
7644 (A & C) != 0. Similarly for NE_EXPR. */
7645 if ((code == EQ_EXPR || code == NE_EXPR)
7646 && TREE_CODE (arg0) == BIT_AND_EXPR
7647 && integer_pow2p (TREE_OPERAND (arg0, 1))
7648 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
7649 return fold (build (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
7650 arg0, integer_zero_node));
7652 /* If we have (A & C) != 0 or (A & C) == 0 and C is a power of
7653 2, then fold the expression into shifts and logical operations. */
7654 tem = fold_single_bit_test (code, arg0, arg1, type);
7658 /* If we have (A & C) == D where D & ~C != 0, convert this into 0.
7659 Similarly for NE_EXPR. */
7660 if ((code == EQ_EXPR || code == NE_EXPR)
7661 && TREE_CODE (arg0) == BIT_AND_EXPR
7662 && TREE_CODE (arg1) == INTEGER_CST
7663 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
7666 = fold (build (BIT_AND_EXPR, TREE_TYPE (arg0),
7667 arg1, build1 (BIT_NOT_EXPR,
7668 TREE_TYPE (TREE_OPERAND (arg0, 1)),
7669 TREE_OPERAND (arg0, 1))));
7670 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
7671 if (integer_nonzerop (dandnotc))
7672 return omit_one_operand (type, rslt, arg0);
7675 /* If we have (A | C) == D where C & ~D != 0, convert this into 0.
7676 Similarly for NE_EXPR. */
7677 if ((code == EQ_EXPR || code == NE_EXPR)
7678 && TREE_CODE (arg0) == BIT_IOR_EXPR
7679 && TREE_CODE (arg1) == INTEGER_CST
7680 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
7683 = fold (build (BIT_AND_EXPR, TREE_TYPE (arg0),
7684 TREE_OPERAND (arg0, 1),
7685 build1 (BIT_NOT_EXPR, TREE_TYPE (arg1), arg1)));
7686 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
7687 if (integer_nonzerop (candnotd))
7688 return omit_one_operand (type, rslt, arg0);
7691 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
7692 and similarly for >= into !=. */
7693 if ((code == LT_EXPR || code == GE_EXPR)
7694 && TREE_UNSIGNED (TREE_TYPE (arg0))
7695 && TREE_CODE (arg1) == LSHIFT_EXPR
7696 && integer_onep (TREE_OPERAND (arg1, 0)))
7697 return build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
7698 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
7699 TREE_OPERAND (arg1, 1)),
7700 fold_convert (TREE_TYPE (arg0), integer_zero_node));
7702 else if ((code == LT_EXPR || code == GE_EXPR)
7703 && TREE_UNSIGNED (TREE_TYPE (arg0))
7704 && (TREE_CODE (arg1) == NOP_EXPR
7705 || TREE_CODE (arg1) == CONVERT_EXPR)
7706 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
7707 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
7709 build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
7710 fold_convert (TREE_TYPE (arg0),
7711 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
7712 TREE_OPERAND (TREE_OPERAND (arg1, 0),
7714 fold_convert (TREE_TYPE (arg0), integer_zero_node));
7716 /* Simplify comparison of something with itself. (For IEEE
7717 floating-point, we can only do some of these simplifications.) */
7718 if (operand_equal_p (arg0, arg1, 0))
7723 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
7724 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
7725 return constant_boolean_node (1, type);
7730 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
7731 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
7732 return constant_boolean_node (1, type);
7733 return fold (build (EQ_EXPR, type, arg0, arg1));
7736 /* For NE, we can only do this simplification if integer
7737 or we don't honor IEEE floating point NaNs. */
7738 if (FLOAT_TYPE_P (TREE_TYPE (arg0))
7739 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
7741 /* ... fall through ... */
7744 return constant_boolean_node (0, type);
7750 /* If we are comparing an expression that just has comparisons
7751 of two integer values, arithmetic expressions of those comparisons,
7752 and constants, we can simplify it. There are only three cases
7753 to check: the two values can either be equal, the first can be
7754 greater, or the second can be greater. Fold the expression for
7755 those three values. Since each value must be 0 or 1, we have
7756 eight possibilities, each of which corresponds to the constant 0
7757 or 1 or one of the six possible comparisons.
7759 This handles common cases like (a > b) == 0 but also handles
7760 expressions like ((x > y) - (y > x)) > 0, which supposedly
7761 occur in macroized code. */
7763 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
7765 tree cval1 = 0, cval2 = 0;
7768 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
7769 /* Don't handle degenerate cases here; they should already
7770 have been handled anyway. */
7771 && cval1 != 0 && cval2 != 0
7772 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
7773 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
7774 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
7775 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
7776 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
7777 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
7778 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
7780 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
7781 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
7783 /* We can't just pass T to eval_subst in case cval1 or cval2
7784 was the same as ARG1. */
7787 = fold (build (code, type,
7788 eval_subst (arg0, cval1, maxval, cval2, minval),
7791 = fold (build (code, type,
7792 eval_subst (arg0, cval1, maxval, cval2, maxval),
7795 = fold (build (code, type,
7796 eval_subst (arg0, cval1, minval, cval2, maxval),
7799 /* All three of these results should be 0 or 1. Confirm they
7800 are. Then use those values to select the proper code
7803 if ((integer_zerop (high_result)
7804 || integer_onep (high_result))
7805 && (integer_zerop (equal_result)
7806 || integer_onep (equal_result))
7807 && (integer_zerop (low_result)
7808 || integer_onep (low_result)))
7810 /* Make a 3-bit mask with the high-order bit being the
7811 value for `>', the next for '=', and the low for '<'. */
7812 switch ((integer_onep (high_result) * 4)
7813 + (integer_onep (equal_result) * 2)
7814 + integer_onep (low_result))
7818 return omit_one_operand (type, integer_zero_node, arg0);
7839 return omit_one_operand (type, integer_one_node, arg0);
7842 tem = build (code, type, cval1, cval2);
7844 return save_expr (tem);
7851 /* If this is a comparison of a field, we may be able to simplify it. */
7852 if (((TREE_CODE (arg0) == COMPONENT_REF
7853 && lang_hooks.can_use_bit_fields_p ())
7854 || TREE_CODE (arg0) == BIT_FIELD_REF)
7855 && (code == EQ_EXPR || code == NE_EXPR)
7856 /* Handle the constant case even without -O
7857 to make sure the warnings are given. */
7858 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
7860 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
7865 /* If this is a comparison of complex values and either or both sides
7866 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
7867 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
7868 This may prevent needless evaluations. */
7869 if ((code == EQ_EXPR || code == NE_EXPR)
7870 && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
7871 && (TREE_CODE (arg0) == COMPLEX_EXPR
7872 || TREE_CODE (arg1) == COMPLEX_EXPR
7873 || TREE_CODE (arg0) == COMPLEX_CST
7874 || TREE_CODE (arg1) == COMPLEX_CST))
7876 tree subtype = TREE_TYPE (TREE_TYPE (arg0));
7877 tree real0, imag0, real1, imag1;
7879 arg0 = save_expr (arg0);
7880 arg1 = save_expr (arg1);
7881 real0 = fold (build1 (REALPART_EXPR, subtype, arg0));
7882 imag0 = fold (build1 (IMAGPART_EXPR, subtype, arg0));
7883 real1 = fold (build1 (REALPART_EXPR, subtype, arg1));
7884 imag1 = fold (build1 (IMAGPART_EXPR, subtype, arg1));
7886 return fold (build ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR
7889 fold (build (code, type, real0, real1)),
7890 fold (build (code, type, imag0, imag1))));
7893 /* Optimize comparisons of strlen vs zero to a compare of the
7894 first character of the string vs zero. To wit,
7895 strlen(ptr) == 0 => *ptr == 0
7896 strlen(ptr) != 0 => *ptr != 0
7897 Other cases should reduce to one of these two (or a constant)
7898 due to the return value of strlen being unsigned. */
7899 if ((code == EQ_EXPR || code == NE_EXPR)
7900 && integer_zerop (arg1)
7901 && TREE_CODE (arg0) == CALL_EXPR)
7903 tree fndecl = get_callee_fndecl (arg0);
7907 && DECL_BUILT_IN (fndecl)
7908 && DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_MD
7909 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
7910 && (arglist = TREE_OPERAND (arg0, 1))
7911 && TREE_CODE (TREE_TYPE (TREE_VALUE (arglist))) == POINTER_TYPE
7912 && ! TREE_CHAIN (arglist))
7913 return fold (build (code, type,
7914 build1 (INDIRECT_REF, char_type_node,
7915 TREE_VALUE(arglist)),
7916 integer_zero_node));
7919 /* Both ARG0 and ARG1 are known to be constants at this point. */
7920 t1 = fold_relational_const (code, type, arg0, arg1);
7921 return (t1 == NULL_TREE ? t : t1);
7924 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
7925 so all simple results must be passed through pedantic_non_lvalue. */
7926 if (TREE_CODE (arg0) == INTEGER_CST)
7928 tem = TREE_OPERAND (t, (integer_zerop (arg0) ? 2 : 1));
7929 /* Only optimize constant conditions when the selected branch
7930 has the same type as the COND_EXPR. This avoids optimizing
7931 away "c ? x : throw", where the throw has a void type. */
7932 if (! VOID_TYPE_P (TREE_TYPE (tem))
7933 || VOID_TYPE_P (type))
7934 return pedantic_non_lvalue (tem);
7937 if (operand_equal_p (arg1, TREE_OPERAND (t, 2), 0))
7938 return pedantic_omit_one_operand (type, arg1, arg0);
7940 /* If we have A op B ? A : C, we may be able to convert this to a
7941 simpler expression, depending on the operation and the values
7942 of B and C. Signed zeros prevent all of these transformations,
7943 for reasons given above each one. */
7945 if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
7946 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
7947 arg1, TREE_OPERAND (arg0, 1))
7948 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
7950 tree arg2 = TREE_OPERAND (t, 2);
7951 enum tree_code comp_code = TREE_CODE (arg0);
7955 /* If we have A op 0 ? A : -A, consider applying the following
7958 A == 0? A : -A same as -A
7959 A != 0? A : -A same as A
7960 A >= 0? A : -A same as abs (A)
7961 A > 0? A : -A same as abs (A)
7962 A <= 0? A : -A same as -abs (A)
7963 A < 0? A : -A same as -abs (A)
7965 None of these transformations work for modes with signed
7966 zeros. If A is +/-0, the first two transformations will
7967 change the sign of the result (from +0 to -0, or vice
7968 versa). The last four will fix the sign of the result,
7969 even though the original expressions could be positive or
7970 negative, depending on the sign of A.
7972 Note that all these transformations are correct if A is
7973 NaN, since the two alternatives (A and -A) are also NaNs. */
7974 if ((FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 1)))
7975 ? real_zerop (TREE_OPERAND (arg0, 1))
7976 : integer_zerop (TREE_OPERAND (arg0, 1)))
7977 && TREE_CODE (arg2) == NEGATE_EXPR
7978 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
7982 tem = fold_convert (TREE_TYPE (TREE_OPERAND (t, 1)), arg1);
7983 tem = fold_convert (type, negate_expr (tem));
7984 return pedantic_non_lvalue (tem);
7986 return pedantic_non_lvalue (fold_convert (type, arg1));
7989 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
7990 arg1 = fold_convert (lang_hooks.types.signed_type
7991 (TREE_TYPE (arg1)), arg1);
7992 arg1 = fold (build1 (ABS_EXPR, TREE_TYPE (arg1), arg1));
7993 return pedantic_non_lvalue (fold_convert (type, arg1));
7996 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
7997 arg1 = fold_convert (lang_hooks.types.signed_type
7998 (TREE_TYPE (arg1)), arg1);
7999 arg1 = fold (build1 (ABS_EXPR, TREE_TYPE (arg1), arg1));
8000 arg1 = negate_expr (fold_convert (type, arg1));
8001 return pedantic_non_lvalue (arg1);
8006 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
8007 A == 0 ? A : 0 is always 0 unless A is -0. Note that
8008 both transformations are correct when A is NaN: A != 0
8009 is then true, and A == 0 is false. */
8011 if (integer_zerop (TREE_OPERAND (arg0, 1)) && integer_zerop (arg2))
8013 if (comp_code == NE_EXPR)
8014 return pedantic_non_lvalue (fold_convert (type, arg1));
8015 else if (comp_code == EQ_EXPR)
8016 return pedantic_non_lvalue (fold_convert (type, integer_zero_node));
8019 /* Try some transformations of A op B ? A : B.
8021 A == B? A : B same as B
8022 A != B? A : B same as A
8023 A >= B? A : B same as max (A, B)
8024 A > B? A : B same as max (B, A)
8025 A <= B? A : B same as min (A, B)
8026 A < B? A : B same as min (B, A)
8028 As above, these transformations don't work in the presence
8029 of signed zeros. For example, if A and B are zeros of
8030 opposite sign, the first two transformations will change
8031 the sign of the result. In the last four, the original
8032 expressions give different results for (A=+0, B=-0) and
8033 (A=-0, B=+0), but the transformed expressions do not.
8035 The first two transformations are correct if either A or B
8036 is a NaN. In the first transformation, the condition will
8037 be false, and B will indeed be chosen. In the case of the
8038 second transformation, the condition A != B will be true,
8039 and A will be chosen.
8041 The conversions to max() and min() are not correct if B is
8042 a number and A is not. The conditions in the original
8043 expressions will be false, so all four give B. The min()
8044 and max() versions would give a NaN instead. */
8045 if (operand_equal_for_comparison_p (TREE_OPERAND (arg0, 1),
8046 arg2, TREE_OPERAND (arg0, 0)))
8048 tree comp_op0 = TREE_OPERAND (arg0, 0);
8049 tree comp_op1 = TREE_OPERAND (arg0, 1);
8050 tree comp_type = TREE_TYPE (comp_op0);
8052 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
8053 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
8063 return pedantic_non_lvalue (fold_convert (type, arg2));
8065 return pedantic_non_lvalue (fold_convert (type, arg1));
8068 /* In C++ a ?: expression can be an lvalue, so put the
8069 operand which will be used if they are equal first
8070 so that we can convert this back to the
8071 corresponding COND_EXPR. */
8072 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
8073 return pedantic_non_lvalue (fold_convert
8074 (type, fold (build (MIN_EXPR, comp_type,
8075 (comp_code == LE_EXPR
8076 ? comp_op0 : comp_op1),
8077 (comp_code == LE_EXPR
8078 ? comp_op1 : comp_op0)))));
8082 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
8083 return pedantic_non_lvalue (fold_convert
8084 (type, fold (build (MAX_EXPR, comp_type,
8085 (comp_code == GE_EXPR
8086 ? comp_op0 : comp_op1),
8087 (comp_code == GE_EXPR
8088 ? comp_op1 : comp_op0)))));
8095 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
8096 we might still be able to simplify this. For example,
8097 if C1 is one less or one more than C2, this might have started
8098 out as a MIN or MAX and been transformed by this function.
8099 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
8101 if (INTEGRAL_TYPE_P (type)
8102 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8103 && TREE_CODE (arg2) == INTEGER_CST)
8107 /* We can replace A with C1 in this case. */
8108 arg1 = fold_convert (type, TREE_OPERAND (arg0, 1));
8109 return fold (build (code, type, TREE_OPERAND (t, 0), arg1,
8110 TREE_OPERAND (t, 2)));
8113 /* If C1 is C2 + 1, this is min(A, C2). */
8114 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
8115 && operand_equal_p (TREE_OPERAND (arg0, 1),
8116 const_binop (PLUS_EXPR, arg2,
8117 integer_one_node, 0), 1))
8118 return pedantic_non_lvalue
8119 (fold (build (MIN_EXPR, type, arg1, arg2)));
8123 /* If C1 is C2 - 1, this is min(A, C2). */
8124 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
8125 && operand_equal_p (TREE_OPERAND (arg0, 1),
8126 const_binop (MINUS_EXPR, arg2,
8127 integer_one_node, 0), 1))
8128 return pedantic_non_lvalue
8129 (fold (build (MIN_EXPR, type, arg1, arg2)));
8133 /* If C1 is C2 - 1, this is max(A, C2). */
8134 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
8135 && operand_equal_p (TREE_OPERAND (arg0, 1),
8136 const_binop (MINUS_EXPR, arg2,
8137 integer_one_node, 0), 1))
8138 return pedantic_non_lvalue
8139 (fold (build (MAX_EXPR, type, arg1, arg2)));
8143 /* If C1 is C2 + 1, this is max(A, C2). */
8144 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
8145 && operand_equal_p (TREE_OPERAND (arg0, 1),
8146 const_binop (PLUS_EXPR, arg2,
8147 integer_one_node, 0), 1))
8148 return pedantic_non_lvalue
8149 (fold (build (MAX_EXPR, type, arg1, arg2)));
8158 /* If the second operand is simpler than the third, swap them
8159 since that produces better jump optimization results. */
8160 if (tree_swap_operands_p (TREE_OPERAND (t, 1),
8161 TREE_OPERAND (t, 2), false))
8163 /* See if this can be inverted. If it can't, possibly because
8164 it was a floating-point inequality comparison, don't do
8166 tem = invert_truthvalue (arg0);
8168 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
8169 return fold (build (code, type, tem,
8170 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1)));
8173 /* Convert A ? 1 : 0 to simply A. */
8174 if (integer_onep (TREE_OPERAND (t, 1))
8175 && integer_zerop (TREE_OPERAND (t, 2))
8176 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
8177 call to fold will try to move the conversion inside
8178 a COND, which will recurse. In that case, the COND_EXPR
8179 is probably the best choice, so leave it alone. */
8180 && type == TREE_TYPE (arg0))
8181 return pedantic_non_lvalue (arg0);
8183 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
8184 over COND_EXPR in cases such as floating point comparisons. */
8185 if (integer_zerop (TREE_OPERAND (t, 1))
8186 && integer_onep (TREE_OPERAND (t, 2))
8187 && truth_value_p (TREE_CODE (arg0)))
8188 return pedantic_non_lvalue (fold_convert (type,
8189 invert_truthvalue (arg0)));
8191 /* Look for expressions of the form A & 2 ? 2 : 0. The result of this
8192 operation is simply A & 2. */
8194 if (integer_zerop (TREE_OPERAND (t, 2))
8195 && TREE_CODE (arg0) == NE_EXPR
8196 && integer_zerop (TREE_OPERAND (arg0, 1))
8197 && integer_pow2p (arg1)
8198 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
8199 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
8201 return pedantic_non_lvalue (fold_convert (type,
8202 TREE_OPERAND (arg0, 0)));
8204 /* Convert A ? B : 0 into A && B if A and B are truth values. */
8205 if (integer_zerop (TREE_OPERAND (t, 2))
8206 && truth_value_p (TREE_CODE (arg0))
8207 && truth_value_p (TREE_CODE (arg1)))
8208 return pedantic_non_lvalue (fold (build (TRUTH_ANDIF_EXPR, type,
8211 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
8212 if (integer_onep (TREE_OPERAND (t, 2))
8213 && truth_value_p (TREE_CODE (arg0))
8214 && truth_value_p (TREE_CODE (arg1)))
8216 /* Only perform transformation if ARG0 is easily inverted. */
8217 tem = invert_truthvalue (arg0);
8218 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
8219 return pedantic_non_lvalue (fold (build (TRUTH_ORIF_EXPR, type,
8226 /* When pedantic, a compound expression can be neither an lvalue
8227 nor an integer constant expression. */
8228 if (TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
8230 /* Don't let (0, 0) be null pointer constant. */
8231 tem = integer_zerop (arg1) ? build1 (NOP_EXPR, type, arg1)
8232 : fold_convert (type, arg1);
8233 return pedantic_non_lvalue (tem);
8237 return build_complex (type, arg0, arg1);
8241 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8243 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
8244 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
8245 TREE_OPERAND (arg0, 1));
8246 else if (TREE_CODE (arg0) == COMPLEX_CST)
8247 return TREE_REALPART (arg0);
8248 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8249 return fold (build (TREE_CODE (arg0), type,
8250 fold (build1 (REALPART_EXPR, type,
8251 TREE_OPERAND (arg0, 0))),
8252 fold (build1 (REALPART_EXPR,
8253 type, TREE_OPERAND (arg0, 1)))));
8257 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8258 return fold_convert (type, integer_zero_node);
8259 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
8260 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
8261 TREE_OPERAND (arg0, 0));
8262 else if (TREE_CODE (arg0) == COMPLEX_CST)
8263 return TREE_IMAGPART (arg0);
8264 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8265 return fold (build (TREE_CODE (arg0), type,
8266 fold (build1 (IMAGPART_EXPR, type,
8267 TREE_OPERAND (arg0, 0))),
8268 fold (build1 (IMAGPART_EXPR, type,
8269 TREE_OPERAND (arg0, 1)))));
8272 /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
8274 case CLEANUP_POINT_EXPR:
8275 if (! has_cleanups (arg0))
8276 return TREE_OPERAND (t, 0);
8279 enum tree_code code0 = TREE_CODE (arg0);
8280 int kind0 = TREE_CODE_CLASS (code0);
8281 tree arg00 = TREE_OPERAND (arg0, 0);
8284 if (kind0 == '1' || code0 == TRUTH_NOT_EXPR)
8285 return fold (build1 (code0, type,
8286 fold (build1 (CLEANUP_POINT_EXPR,
8287 TREE_TYPE (arg00), arg00))));
8289 if (kind0 == '<' || kind0 == '2'
8290 || code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR
8291 || code0 == TRUTH_AND_EXPR || code0 == TRUTH_OR_EXPR
8292 || code0 == TRUTH_XOR_EXPR)
8294 arg01 = TREE_OPERAND (arg0, 1);
8296 if (TREE_CONSTANT (arg00)
8297 || ((code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR)
8298 && ! has_cleanups (arg00)))
8299 return fold (build (code0, type, arg00,
8300 fold (build1 (CLEANUP_POINT_EXPR,
8301 TREE_TYPE (arg01), arg01))));
8303 if (TREE_CONSTANT (arg01))
8304 return fold (build (code0, type,
8305 fold (build1 (CLEANUP_POINT_EXPR,
8306 TREE_TYPE (arg00), arg00)),
8314 /* Check for a built-in function. */
8315 if (TREE_CODE (TREE_OPERAND (t, 0)) == ADDR_EXPR
8316 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0))
8318 && DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (t, 0), 0)))
8320 tree tmp = fold_builtin (t);
8328 } /* switch (code) */
8331 #ifdef ENABLE_FOLD_CHECKING
8334 static void fold_checksum_tree (tree, struct md5_ctx *, htab_t);
8335 static void fold_check_failed (tree, tree);
8336 void print_fold_checksum (tree);
8338 /* When --enable-checking=fold, compute a digest of expr before
8339 and after actual fold call to see if fold did not accidentally
8340 change original expr. */
8347 unsigned char checksum_before[16], checksum_after[16];
8350 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
8351 md5_init_ctx (&ctx);
8352 fold_checksum_tree (expr, &ctx, ht);
8353 md5_finish_ctx (&ctx, checksum_before);
8356 ret = fold_1 (expr);
8358 md5_init_ctx (&ctx);
8359 fold_checksum_tree (expr, &ctx, ht);
8360 md5_finish_ctx (&ctx, checksum_after);
8363 if (memcmp (checksum_before, checksum_after, 16))
8364 fold_check_failed (expr, ret);
8370 print_fold_checksum (tree expr)
8373 unsigned char checksum[16], cnt;
8376 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
8377 md5_init_ctx (&ctx);
8378 fold_checksum_tree (expr, &ctx, ht);
8379 md5_finish_ctx (&ctx, checksum);
8381 for (cnt = 0; cnt < 16; ++cnt)
8382 fprintf (stderr, "%02x", checksum[cnt]);
8383 putc ('\n', stderr);
8387 fold_check_failed (tree expr ATTRIBUTE_UNUSED, tree ret ATTRIBUTE_UNUSED)
8389 internal_error ("fold check: original tree changed by fold");
8393 fold_checksum_tree (tree expr, struct md5_ctx *ctx, htab_t ht)
8396 enum tree_code code;
8397 char buf[sizeof (struct tree_decl)];
8400 if (sizeof (struct tree_exp) + 5 * sizeof (tree)
8401 > sizeof (struct tree_decl)
8402 || sizeof (struct tree_type) > sizeof (struct tree_decl))
8406 slot = htab_find_slot (ht, expr, INSERT);
8410 code = TREE_CODE (expr);
8411 if (code == SAVE_EXPR && SAVE_EXPR_NOPLACEHOLDER (expr))
8413 /* Allow SAVE_EXPR_NOPLACEHOLDER flag to be modified. */
8414 memcpy (buf, expr, tree_size (expr));
8416 SAVE_EXPR_NOPLACEHOLDER (expr) = 0;
8418 else if (TREE_CODE_CLASS (code) == 'd' && DECL_ASSEMBLER_NAME_SET_P (expr))
8420 /* Allow DECL_ASSEMBLER_NAME to be modified. */
8421 memcpy (buf, expr, tree_size (expr));
8423 SET_DECL_ASSEMBLER_NAME (expr, NULL);
8425 else if (TREE_CODE_CLASS (code) == 't'
8426 && (TYPE_POINTER_TO (expr) || TYPE_REFERENCE_TO (expr)))
8428 /* Allow TYPE_POINTER_TO and TYPE_REFERENCE_TO to be modified. */
8429 memcpy (buf, expr, tree_size (expr));
8431 TYPE_POINTER_TO (expr) = NULL;
8432 TYPE_REFERENCE_TO (expr) = NULL;
8434 md5_process_bytes (expr, tree_size (expr), ctx);
8435 fold_checksum_tree (TREE_TYPE (expr), ctx, ht);
8436 if (TREE_CODE_CLASS (code) != 't' && TREE_CODE_CLASS (code) != 'd')
8437 fold_checksum_tree (TREE_CHAIN (expr), ctx, ht);
8438 len = TREE_CODE_LENGTH (code);
8439 switch (TREE_CODE_CLASS (code))
8445 md5_process_bytes (TREE_STRING_POINTER (expr),
8446 TREE_STRING_LENGTH (expr), ctx);
8449 fold_checksum_tree (TREE_REALPART (expr), ctx, ht);
8450 fold_checksum_tree (TREE_IMAGPART (expr), ctx, ht);
8453 fold_checksum_tree (TREE_VECTOR_CST_ELTS (expr), ctx, ht);
8463 fold_checksum_tree (TREE_PURPOSE (expr), ctx, ht);
8464 fold_checksum_tree (TREE_VALUE (expr), ctx, ht);
8467 for (i = 0; i < TREE_VEC_LENGTH (expr); ++i)
8468 fold_checksum_tree (TREE_VEC_ELT (expr, i), ctx, ht);
8477 case SAVE_EXPR: len = 2; break;
8478 case GOTO_SUBROUTINE_EXPR: len = 0; break;
8479 case RTL_EXPR: len = 0; break;
8480 case WITH_CLEANUP_EXPR: len = 2; break;
8489 for (i = 0; i < len; ++i)
8490 fold_checksum_tree (TREE_OPERAND (expr, i), ctx, ht);
8493 fold_checksum_tree (DECL_SIZE (expr), ctx, ht);
8494 fold_checksum_tree (DECL_SIZE_UNIT (expr), ctx, ht);
8495 fold_checksum_tree (DECL_NAME (expr), ctx, ht);
8496 fold_checksum_tree (DECL_CONTEXT (expr), ctx, ht);
8497 fold_checksum_tree (DECL_ARGUMENTS (expr), ctx, ht);
8498 fold_checksum_tree (DECL_RESULT_FLD (expr), ctx, ht);
8499 fold_checksum_tree (DECL_INITIAL (expr), ctx, ht);
8500 fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr), ctx, ht);
8501 fold_checksum_tree (DECL_SECTION_NAME (expr), ctx, ht);
8502 fold_checksum_tree (DECL_ATTRIBUTES (expr), ctx, ht);
8503 fold_checksum_tree (DECL_VINDEX (expr), ctx, ht);
8506 fold_checksum_tree (TYPE_VALUES (expr), ctx, ht);
8507 fold_checksum_tree (TYPE_SIZE (expr), ctx, ht);
8508 fold_checksum_tree (TYPE_SIZE_UNIT (expr), ctx, ht);
8509 fold_checksum_tree (TYPE_ATTRIBUTES (expr), ctx, ht);
8510 fold_checksum_tree (TYPE_NAME (expr), ctx, ht);
8511 fold_checksum_tree (TYPE_MIN_VALUE (expr), ctx, ht);
8512 fold_checksum_tree (TYPE_MAX_VALUE (expr), ctx, ht);
8513 fold_checksum_tree (TYPE_MAIN_VARIANT (expr), ctx, ht);
8514 fold_checksum_tree (TYPE_BINFO (expr), ctx, ht);
8515 fold_checksum_tree (TYPE_CONTEXT (expr), ctx, ht);
8524 /* Perform constant folding and related simplification of initializer
8525 expression EXPR. This behaves identically to "fold" but ignores
8526 potential run-time traps and exceptions that fold must preserve. */
8529 fold_initializer (tree expr)
8531 int saved_signaling_nans = flag_signaling_nans;
8532 int saved_trapping_math = flag_trapping_math;
8533 int saved_trapv = flag_trapv;
8536 flag_signaling_nans = 0;
8537 flag_trapping_math = 0;
8540 result = fold (expr);
8542 flag_signaling_nans = saved_signaling_nans;
8543 flag_trapping_math = saved_trapping_math;
8544 flag_trapv = saved_trapv;
8549 /* Determine if first argument is a multiple of second argument. Return 0 if
8550 it is not, or we cannot easily determined it to be.
8552 An example of the sort of thing we care about (at this point; this routine
8553 could surely be made more general, and expanded to do what the *_DIV_EXPR's
8554 fold cases do now) is discovering that
8556 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
8562 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
8564 This code also handles discovering that
8566 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
8568 is a multiple of 8 so we don't have to worry about dealing with a
8571 Note that we *look* inside a SAVE_EXPR only to determine how it was
8572 calculated; it is not safe for fold to do much of anything else with the
8573 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
8574 at run time. For example, the latter example above *cannot* be implemented
8575 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
8576 evaluation time of the original SAVE_EXPR is not necessarily the same at
8577 the time the new expression is evaluated. The only optimization of this
8578 sort that would be valid is changing
8580 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
8584 SAVE_EXPR (I) * SAVE_EXPR (J)
8586 (where the same SAVE_EXPR (J) is used in the original and the
8587 transformed version). */
8590 multiple_of_p (tree type, tree top, tree bottom)
8592 if (operand_equal_p (top, bottom, 0))
8595 if (TREE_CODE (type) != INTEGER_TYPE)
8598 switch (TREE_CODE (top))
8601 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
8602 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
8606 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
8607 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
8610 if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
8614 op1 = TREE_OPERAND (top, 1);
8615 /* const_binop may not detect overflow correctly,
8616 so check for it explicitly here. */
8617 if (TYPE_PRECISION (TREE_TYPE (size_one_node))
8618 > TREE_INT_CST_LOW (op1)
8619 && TREE_INT_CST_HIGH (op1) == 0
8620 && 0 != (t1 = fold_convert (type,
8621 const_binop (LSHIFT_EXPR,
8624 && ! TREE_OVERFLOW (t1))
8625 return multiple_of_p (type, t1, bottom);
8630 /* Can't handle conversions from non-integral or wider integral type. */
8631 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
8632 || (TYPE_PRECISION (type)
8633 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
8636 /* .. fall through ... */
8639 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
8642 if (TREE_CODE (bottom) != INTEGER_CST
8643 || (TREE_UNSIGNED (type)
8644 && (tree_int_cst_sgn (top) < 0
8645 || tree_int_cst_sgn (bottom) < 0)))
8647 return integer_zerop (const_binop (TRUNC_MOD_EXPR,
8655 /* Return true if `t' is known to be non-negative. */
8658 tree_expr_nonnegative_p (tree t)
8660 switch (TREE_CODE (t))
8666 return tree_int_cst_sgn (t) >= 0;
8669 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
8672 if (FLOAT_TYPE_P (TREE_TYPE (t)))
8673 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8674 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8676 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
8677 both unsigned and at least 2 bits shorter than the result. */
8678 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
8679 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
8680 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
8682 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
8683 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
8684 if (TREE_CODE (inner1) == INTEGER_TYPE && TREE_UNSIGNED (inner1)
8685 && TREE_CODE (inner2) == INTEGER_TYPE && TREE_UNSIGNED (inner2))
8687 unsigned int prec = MAX (TYPE_PRECISION (inner1),
8688 TYPE_PRECISION (inner2)) + 1;
8689 return prec < TYPE_PRECISION (TREE_TYPE (t));
8695 if (FLOAT_TYPE_P (TREE_TYPE (t)))
8697 /* x * x for floating point x is always non-negative. */
8698 if (operand_equal_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1), 0))
8700 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8701 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8704 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
8705 both unsigned and their total bits is shorter than the result. */
8706 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
8707 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
8708 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
8710 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
8711 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
8712 if (TREE_CODE (inner1) == INTEGER_TYPE && TREE_UNSIGNED (inner1)
8713 && TREE_CODE (inner2) == INTEGER_TYPE && TREE_UNSIGNED (inner2))
8714 return TYPE_PRECISION (inner1) + TYPE_PRECISION (inner2)
8715 < TYPE_PRECISION (TREE_TYPE (t));
8719 case TRUNC_DIV_EXPR:
8721 case FLOOR_DIV_EXPR:
8722 case ROUND_DIV_EXPR:
8723 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8724 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8726 case TRUNC_MOD_EXPR:
8728 case FLOOR_MOD_EXPR:
8729 case ROUND_MOD_EXPR:
8730 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8733 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8734 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8738 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
8739 tree outer_type = TREE_TYPE (t);
8741 if (TREE_CODE (outer_type) == REAL_TYPE)
8743 if (TREE_CODE (inner_type) == REAL_TYPE)
8744 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8745 if (TREE_CODE (inner_type) == INTEGER_TYPE)
8747 if (TREE_UNSIGNED (inner_type))
8749 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8752 else if (TREE_CODE (outer_type) == INTEGER_TYPE)
8754 if (TREE_CODE (inner_type) == REAL_TYPE)
8755 return tree_expr_nonnegative_p (TREE_OPERAND (t,0));
8756 if (TREE_CODE (inner_type) == INTEGER_TYPE)
8757 return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
8758 && TREE_UNSIGNED (inner_type);
8764 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
8765 && tree_expr_nonnegative_p (TREE_OPERAND (t, 2));
8767 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8769 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8770 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8772 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8773 || tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8775 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8777 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8779 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8780 case NON_LVALUE_EXPR:
8781 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8783 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8785 return rtl_expr_nonnegative_p (RTL_EXPR_RTL (t));
8789 tree fndecl = get_callee_fndecl (t);
8790 tree arglist = TREE_OPERAND (t, 1);
8792 && DECL_BUILT_IN (fndecl)
8793 && DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_MD)
8794 switch (DECL_FUNCTION_CODE (fndecl))
8796 #define CASE_BUILTIN_F(BUILT_IN_FN) \
8797 case BUILT_IN_FN: case BUILT_IN_FN##F: case BUILT_IN_FN##L:
8798 #define CASE_BUILTIN_I(BUILT_IN_FN) \
8799 case BUILT_IN_FN: case BUILT_IN_FN##L: case BUILT_IN_FN##LL:
8801 CASE_BUILTIN_F (BUILT_IN_ACOS)
8802 CASE_BUILTIN_F (BUILT_IN_ACOSH)
8803 CASE_BUILTIN_F (BUILT_IN_CABS)
8804 CASE_BUILTIN_F (BUILT_IN_COSH)
8805 CASE_BUILTIN_F (BUILT_IN_ERFC)
8806 CASE_BUILTIN_F (BUILT_IN_EXP)
8807 CASE_BUILTIN_F (BUILT_IN_EXP10)
8808 CASE_BUILTIN_F (BUILT_IN_EXP2)
8809 CASE_BUILTIN_F (BUILT_IN_FABS)
8810 CASE_BUILTIN_F (BUILT_IN_FDIM)
8811 CASE_BUILTIN_F (BUILT_IN_FREXP)
8812 CASE_BUILTIN_F (BUILT_IN_HYPOT)
8813 CASE_BUILTIN_F (BUILT_IN_POW10)
8814 CASE_BUILTIN_F (BUILT_IN_SQRT)
8815 CASE_BUILTIN_I (BUILT_IN_FFS)
8816 CASE_BUILTIN_I (BUILT_IN_PARITY)
8817 CASE_BUILTIN_I (BUILT_IN_POPCOUNT)
8821 CASE_BUILTIN_F (BUILT_IN_ASINH)
8822 CASE_BUILTIN_F (BUILT_IN_ATAN)
8823 CASE_BUILTIN_F (BUILT_IN_ATANH)
8824 CASE_BUILTIN_F (BUILT_IN_CBRT)
8825 CASE_BUILTIN_F (BUILT_IN_CEIL)
8826 CASE_BUILTIN_F (BUILT_IN_ERF)
8827 CASE_BUILTIN_F (BUILT_IN_EXPM1)
8828 CASE_BUILTIN_F (BUILT_IN_FLOOR)
8829 CASE_BUILTIN_F (BUILT_IN_FMOD)
8830 CASE_BUILTIN_F (BUILT_IN_LDEXP)
8831 CASE_BUILTIN_F (BUILT_IN_LLRINT)
8832 CASE_BUILTIN_F (BUILT_IN_LLROUND)
8833 CASE_BUILTIN_F (BUILT_IN_LRINT)
8834 CASE_BUILTIN_F (BUILT_IN_LROUND)
8835 CASE_BUILTIN_F (BUILT_IN_MODF)
8836 CASE_BUILTIN_F (BUILT_IN_NEARBYINT)
8837 CASE_BUILTIN_F (BUILT_IN_POW)
8838 CASE_BUILTIN_F (BUILT_IN_RINT)
8839 CASE_BUILTIN_F (BUILT_IN_ROUND)
8840 CASE_BUILTIN_F (BUILT_IN_SIGNBIT)
8841 CASE_BUILTIN_F (BUILT_IN_SINH)
8842 CASE_BUILTIN_F (BUILT_IN_TANH)
8843 CASE_BUILTIN_F (BUILT_IN_TRUNC)
8844 /* True if the 1st argument is nonnegative. */
8845 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
8847 CASE_BUILTIN_F(BUILT_IN_FMAX)
8848 /* True if the 1st OR 2nd arguments are nonnegative. */
8849 return tree_expr_nonnegative_p (TREE_VALUE (arglist))
8850 || tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist)));
8852 CASE_BUILTIN_F(BUILT_IN_FMIN)
8853 /* True if the 1st AND 2nd arguments are nonnegative. */
8854 return tree_expr_nonnegative_p (TREE_VALUE (arglist))
8855 && tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist)));
8857 CASE_BUILTIN_F(BUILT_IN_COPYSIGN)
8858 /* True if the 2nd argument is nonnegative. */
8859 return tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist)));
8863 #undef CASE_BUILTIN_F
8864 #undef CASE_BUILTIN_I
8868 /* ... fall through ... */
8871 if (truth_value_p (TREE_CODE (t)))
8872 /* Truth values evaluate to 0 or 1, which is nonnegative. */
8876 /* We don't know sign of `t', so be conservative and return false. */
8880 /* Return true when T is an address and is known to be nonzero.
8881 For floating point we further ensure that T is not denormal.
8882 Similar logic is present in nonzero_address in rtlanal.h */
8885 tree_expr_nonzero_p (tree t)
8887 tree type = TREE_TYPE (t);
8889 /* Doing something usefull for floating point would need more work. */
8890 if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
8893 switch (TREE_CODE (t))
8896 if (!TREE_UNSIGNED (type) && !flag_wrapv)
8897 return tree_expr_nonzero_p (TREE_OPERAND (t, 0));
8900 return !integer_zerop (t);
8903 if (!TREE_UNSIGNED (type) && !flag_wrapv)
8905 /* With the presence of negative values it is hard
8906 to say something. */
8907 if (!tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8908 || !tree_expr_nonnegative_p (TREE_OPERAND (t, 1)))
8910 /* One of operands must be positive and the other non-negative. */
8911 return (tree_expr_nonzero_p (TREE_OPERAND (t, 0))
8912 || tree_expr_nonzero_p (TREE_OPERAND (t, 1)));
8917 if (!TREE_UNSIGNED (type) && !flag_wrapv)
8919 return (tree_expr_nonzero_p (TREE_OPERAND (t, 0))
8920 && tree_expr_nonzero_p (TREE_OPERAND (t, 1)));
8926 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
8927 tree outer_type = TREE_TYPE (t);
8929 return (TYPE_PRECISION (inner_type) >= TYPE_PRECISION (outer_type)
8930 && tree_expr_nonzero_p (TREE_OPERAND (t, 0)));
8935 /* Weak declarations may link to NULL. */
8936 if (DECL_P (TREE_OPERAND (t, 0)))
8937 return !DECL_WEAK (TREE_OPERAND (t, 0));
8938 /* Constants and all other cases are never weak. */
8942 return (tree_expr_nonzero_p (TREE_OPERAND (t, 1))
8943 && tree_expr_nonzero_p (TREE_OPERAND (t, 2)));
8946 return (tree_expr_nonzero_p (TREE_OPERAND (t, 0))
8947 && tree_expr_nonzero_p (TREE_OPERAND (t, 1)));
8950 if (tree_expr_nonzero_p (TREE_OPERAND (t, 0)))
8952 /* When both operands are nonzero, then MAX must be too. */
8953 if (tree_expr_nonzero_p (TREE_OPERAND (t, 1)))
8956 /* MAX where operand 0 is positive is positive. */
8957 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8959 /* MAX where operand 1 is positive is positive. */
8960 else if (tree_expr_nonzero_p (TREE_OPERAND (t, 1))
8961 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1)))
8968 return tree_expr_nonzero_p (TREE_OPERAND (t, 1));
8971 case NON_LVALUE_EXPR:
8972 return tree_expr_nonzero_p (TREE_OPERAND (t, 0));
8980 /* Return true if `r' is known to be non-negative.
8981 Only handles constants at the moment. */
8984 rtl_expr_nonnegative_p (rtx r)
8986 switch (GET_CODE (r))
8989 return INTVAL (r) >= 0;
8992 if (GET_MODE (r) == VOIDmode)
8993 return CONST_DOUBLE_HIGH (r) >= 0;
9001 units = CONST_VECTOR_NUNITS (r);
9003 for (i = 0; i < units; ++i)
9005 elt = CONST_VECTOR_ELT (r, i);
9006 if (!rtl_expr_nonnegative_p (elt))
9015 /* These are always nonnegative. */
9023 /* Return the tree for neg (ARG0) when ARG0 is known to be either
9024 an integer constant or real constant.
9026 TYPE is the type of the result. */
9029 fold_negate_const (tree arg0, tree type)
9033 if (TREE_CODE (arg0) == INTEGER_CST)
9035 unsigned HOST_WIDE_INT low;
9037 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
9038 TREE_INT_CST_HIGH (arg0),
9040 t = build_int_2 (low, high);
9041 TREE_TYPE (t) = type;
9043 = (TREE_OVERFLOW (arg0)
9044 | force_fit_type (t, overflow && !TREE_UNSIGNED (type)));
9045 TREE_CONSTANT_OVERFLOW (t)
9046 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
9048 else if (TREE_CODE (arg0) == REAL_CST)
9049 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
9050 #ifdef ENABLE_CHECKING
9058 /* Return the tree for abs (ARG0) when ARG0 is known to be either
9059 an integer constant or real constant.
9061 TYPE is the type of the result. */
9064 fold_abs_const (tree arg0, tree type)
9068 if (TREE_CODE (arg0) == INTEGER_CST)
9070 /* If the value is unsigned, then the absolute value is
9071 the same as the ordinary value. */
9072 if (TREE_UNSIGNED (type))
9074 /* Similarly, if the value is non-negative. */
9075 else if (INT_CST_LT (integer_minus_one_node, arg0))
9077 /* If the value is negative, then the absolute value is
9081 unsigned HOST_WIDE_INT low;
9083 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
9084 TREE_INT_CST_HIGH (arg0),
9086 t = build_int_2 (low, high);
9087 TREE_TYPE (t) = type;
9089 = (TREE_OVERFLOW (arg0)
9090 | force_fit_type (t, overflow));
9091 TREE_CONSTANT_OVERFLOW (t)
9092 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
9096 else if (TREE_CODE (arg0) == REAL_CST)
9098 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
9099 return build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
9103 #ifdef ENABLE_CHECKING
9111 /* Given CODE, a relational operator, the target type, TYPE and two
9112 constant operands OP0 and OP1, return the result of the
9113 relational operation. If the result is not a compile time
9114 constant, then return NULL_TREE. */
9117 fold_relational_const (enum tree_code code, tree type, tree op0, tree op1)
9122 /* From here on, the only cases we handle are when the result is
9123 known to be a constant.
9125 To compute GT, swap the arguments and do LT.
9126 To compute GE, do LT and invert the result.
9127 To compute LE, swap the arguments, do LT and invert the result.
9128 To compute NE, do EQ and invert the result.
9130 Therefore, the code below must handle only EQ and LT. */
9132 if (code == LE_EXPR || code == GT_EXPR)
9134 tem = op0, op0 = op1, op1 = tem;
9135 code = swap_tree_comparison (code);
9138 /* Note that it is safe to invert for real values here because we
9139 will check below in the one case that it matters. */
9143 if (code == NE_EXPR || code == GE_EXPR)
9146 code = invert_tree_comparison (code);
9149 /* Compute a result for LT or EQ if args permit;
9150 Otherwise return T. */
9151 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
9153 if (code == EQ_EXPR)
9154 tem = build_int_2 (tree_int_cst_equal (op0, op1), 0);
9156 tem = build_int_2 ((TREE_UNSIGNED (TREE_TYPE (op0))
9157 ? INT_CST_LT_UNSIGNED (op0, op1)
9158 : INT_CST_LT (op0, op1)),
9162 else if (code == EQ_EXPR && !TREE_SIDE_EFFECTS (op0)
9163 && integer_zerop (op1) && tree_expr_nonzero_p (op0))
9164 tem = build_int_2 (0, 0);
9166 /* Two real constants can be compared explicitly. */
9167 else if (TREE_CODE (op0) == REAL_CST && TREE_CODE (op1) == REAL_CST)
9169 /* If either operand is a NaN, the result is false with two
9170 exceptions: First, an NE_EXPR is true on NaNs, but that case
9171 is already handled correctly since we will be inverting the
9172 result for NE_EXPR. Second, if we had inverted a LE_EXPR
9173 or a GE_EXPR into a LT_EXPR, we must return true so that it
9174 will be inverted into false. */
9176 if (REAL_VALUE_ISNAN (TREE_REAL_CST (op0))
9177 || REAL_VALUE_ISNAN (TREE_REAL_CST (op1)))
9178 tem = build_int_2 (invert && code == LT_EXPR, 0);
9180 else if (code == EQ_EXPR)
9181 tem = build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (op0),
9182 TREE_REAL_CST (op1)),
9185 tem = build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (op0),
9186 TREE_REAL_CST (op1)),
9190 if (tem == NULL_TREE)
9194 TREE_INT_CST_LOW (tem) ^= 1;
9196 TREE_TYPE (tem) = type;
9197 if (TREE_CODE (type) == BOOLEAN_TYPE)
9198 return (*lang_hooks.truthvalue_conversion) (tem);
9202 #include "gt-fold-const.h"