1 /* Fold a constant sub-tree into a single node for C-compiler
2 Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
3 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
22 /*@@ This file should be rewritten to use an arbitrary precision
23 @@ representation for "struct tree_int_cst" and "struct tree_real_cst".
24 @@ Perhaps the routines could also be used for bc/dc, and made a lib.
25 @@ The routines that translate from the ap rep should
26 @@ warn if precision et. al. is lost.
27 @@ This would also make life easier when this technology is used
28 @@ for cross-compilers. */
30 /* The entry points in this file are fold, size_int_wide, size_binop
33 fold takes a tree as argument and returns a simplified tree.
35 size_binop takes a tree code for an arithmetic operation
36 and two operands that are trees, and produces a tree for the
37 result, assuming the type comes from `sizetype'.
39 size_int takes an integer value, and creates a tree constant
40 with type from `sizetype'.
42 force_fit_type takes a constant and prior overflow indicator, and
43 forces the value to fit the type. It returns an overflow indicator. */
47 #include "coretypes.h"
58 #include "langhooks.h"
61 /* The following constants represent a bit based encoding of GCC's
62 comparison operators. This encoding simplifies transformations
63 on relational comparison operators, such as AND and OR. */
64 enum comparison_code {
83 static void encode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT, HOST_WIDE_INT);
84 static void decode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
85 static bool negate_mathfn_p (enum built_in_function);
86 static bool negate_expr_p (tree);
87 static tree negate_expr (tree);
88 static tree split_tree (tree, enum tree_code, tree *, tree *, tree *, int);
89 static tree associate_trees (tree, tree, enum tree_code, tree);
90 static tree const_binop (enum tree_code, tree, tree, int);
91 static hashval_t size_htab_hash (const void *);
92 static int size_htab_eq (const void *, const void *);
93 static tree fold_convert_const (enum tree_code, tree, tree);
94 static enum tree_code invert_tree_comparison (enum tree_code, bool);
95 static enum comparison_code comparison_to_compcode (enum tree_code);
96 static enum tree_code compcode_to_comparison (enum comparison_code);
97 static tree combine_comparisons (enum tree_code, enum tree_code,
98 enum tree_code, tree, tree, tree);
99 static int truth_value_p (enum tree_code);
100 static int operand_equal_for_comparison_p (tree, tree, tree);
101 static int twoval_comparison_p (tree, tree *, tree *, int *);
102 static tree eval_subst (tree, tree, tree, tree, tree);
103 static tree pedantic_omit_one_operand (tree, tree, tree);
104 static tree distribute_bit_expr (enum tree_code, tree, tree, tree);
105 static tree make_bit_field_ref (tree, tree, int, int, int);
106 static tree optimize_bit_field_compare (enum tree_code, tree, tree, tree);
107 static tree decode_field_reference (tree, HOST_WIDE_INT *, HOST_WIDE_INT *,
108 enum machine_mode *, int *, int *,
110 static int all_ones_mask_p (tree, int);
111 static tree sign_bit_p (tree, tree);
112 static int simple_operand_p (tree);
113 static tree range_binop (enum tree_code, tree, tree, int, tree, int);
114 static tree make_range (tree, int *, tree *, tree *);
115 static tree build_range_check (tree, tree, int, tree, tree);
116 static int merge_ranges (int *, tree *, tree *, int, tree, tree, int, tree,
118 static tree fold_range_test (tree);
119 static tree fold_cond_expr_with_comparison (tree, tree, tree);
120 static tree unextend (tree, int, int, tree);
121 static tree fold_truthop (enum tree_code, tree, tree, tree);
122 static tree optimize_minmax_comparison (tree);
123 static tree extract_muldiv (tree, tree, enum tree_code, tree);
124 static tree extract_muldiv_1 (tree, tree, enum tree_code, tree);
125 static int multiple_of_p (tree, tree, tree);
126 static tree constant_boolean_node (int, tree);
127 static tree fold_binary_op_with_conditional_arg (enum tree_code, tree, tree,
129 static bool fold_real_zero_addition_p (tree, tree, int);
130 static tree fold_mathfn_compare (enum built_in_function, enum tree_code,
132 static tree fold_inf_compare (enum tree_code, tree, tree, tree);
133 static tree fold_div_compare (enum tree_code, tree, tree, tree);
134 static bool reorder_operands_p (tree, tree);
135 static tree fold_negate_const (tree, tree);
136 static tree fold_not_const (tree, tree);
137 static tree fold_relational_const (enum tree_code, tree, tree, tree);
138 static tree fold_relational_hi_lo (enum tree_code *, const tree,
141 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
142 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
143 and SUM1. Then this yields nonzero if overflow occurred during the
146 Overflow occurs if A and B have the same sign, but A and SUM differ in
147 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
149 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
151 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
152 We do that by representing the two-word integer in 4 words, with only
153 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
154 number. The value of the word is LOWPART + HIGHPART * BASE. */
157 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
158 #define HIGHPART(x) \
159 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
160 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
162 /* Unpack a two-word integer into 4 words.
163 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
164 WORDS points to the array of HOST_WIDE_INTs. */
167 encode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT low, HOST_WIDE_INT hi)
169 words[0] = LOWPART (low);
170 words[1] = HIGHPART (low);
171 words[2] = LOWPART (hi);
172 words[3] = HIGHPART (hi);
175 /* Pack an array of 4 words into a two-word integer.
176 WORDS points to the array of words.
177 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
180 decode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT *low,
183 *low = words[0] + words[1] * BASE;
184 *hi = words[2] + words[3] * BASE;
187 /* Make the integer constant T valid for its type by setting to 0 or 1 all
188 the bits in the constant that don't belong in the type.
190 Return 1 if a signed overflow occurs, 0 otherwise. If OVERFLOW is
191 nonzero, a signed overflow has already occurred in calculating T, so
195 force_fit_type (tree t, int overflow)
197 unsigned HOST_WIDE_INT low;
201 if (TREE_CODE (t) == REAL_CST)
203 /* ??? Used to check for overflow here via CHECK_FLOAT_TYPE.
204 Consider doing it via real_convert now. */
208 else if (TREE_CODE (t) != INTEGER_CST)
211 low = TREE_INT_CST_LOW (t);
212 high = TREE_INT_CST_HIGH (t);
214 if (POINTER_TYPE_P (TREE_TYPE (t))
215 || TREE_CODE (TREE_TYPE (t)) == OFFSET_TYPE)
218 prec = TYPE_PRECISION (TREE_TYPE (t));
220 /* First clear all bits that are beyond the type's precision. */
222 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
224 else if (prec > HOST_BITS_PER_WIDE_INT)
225 TREE_INT_CST_HIGH (t)
226 &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
229 TREE_INT_CST_HIGH (t) = 0;
230 if (prec < HOST_BITS_PER_WIDE_INT)
231 TREE_INT_CST_LOW (t) &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
234 /* Unsigned types do not suffer sign extension or overflow unless they
236 if (TYPE_UNSIGNED (TREE_TYPE (t))
237 && ! (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
238 && TYPE_IS_SIZETYPE (TREE_TYPE (t))))
241 /* If the value's sign bit is set, extend the sign. */
242 if (prec != 2 * HOST_BITS_PER_WIDE_INT
243 && (prec > HOST_BITS_PER_WIDE_INT
244 ? 0 != (TREE_INT_CST_HIGH (t)
246 << (prec - HOST_BITS_PER_WIDE_INT - 1)))
247 : 0 != (TREE_INT_CST_LOW (t)
248 & ((unsigned HOST_WIDE_INT) 1 << (prec - 1)))))
250 /* Value is negative:
251 set to 1 all the bits that are outside this type's precision. */
252 if (prec > HOST_BITS_PER_WIDE_INT)
253 TREE_INT_CST_HIGH (t)
254 |= ((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
257 TREE_INT_CST_HIGH (t) = -1;
258 if (prec < HOST_BITS_PER_WIDE_INT)
259 TREE_INT_CST_LOW (t) |= ((unsigned HOST_WIDE_INT) (-1) << prec);
263 /* Return nonzero if signed overflow occurred. */
265 ((overflow | (low ^ TREE_INT_CST_LOW (t)) | (high ^ TREE_INT_CST_HIGH (t)))
269 /* Add two doubleword integers with doubleword result.
270 Each argument is given as two `HOST_WIDE_INT' pieces.
271 One argument is L1 and H1; the other, L2 and H2.
272 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
275 add_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
276 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
277 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
279 unsigned HOST_WIDE_INT l;
283 h = h1 + h2 + (l < l1);
287 return OVERFLOW_SUM_SIGN (h1, h2, h);
290 /* Negate a doubleword integer with doubleword result.
291 Return nonzero if the operation overflows, assuming it's signed.
292 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
293 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
296 neg_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
297 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
303 return (*hv & h1) < 0;
313 /* Multiply two doubleword integers with doubleword result.
314 Return nonzero if the operation overflows, assuming it's signed.
315 Each argument is given as two `HOST_WIDE_INT' pieces.
316 One argument is L1 and H1; the other, L2 and H2.
317 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
320 mul_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
321 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
322 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
324 HOST_WIDE_INT arg1[4];
325 HOST_WIDE_INT arg2[4];
326 HOST_WIDE_INT prod[4 * 2];
327 unsigned HOST_WIDE_INT carry;
329 unsigned HOST_WIDE_INT toplow, neglow;
330 HOST_WIDE_INT tophigh, neghigh;
332 encode (arg1, l1, h1);
333 encode (arg2, l2, h2);
335 memset (prod, 0, sizeof prod);
337 for (i = 0; i < 4; i++)
340 for (j = 0; j < 4; j++)
343 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
344 carry += arg1[i] * arg2[j];
345 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
347 prod[k] = LOWPART (carry);
348 carry = HIGHPART (carry);
353 decode (prod, lv, hv); /* This ignores prod[4] through prod[4*2-1] */
355 /* Check for overflow by calculating the top half of the answer in full;
356 it should agree with the low half's sign bit. */
357 decode (prod + 4, &toplow, &tophigh);
360 neg_double (l2, h2, &neglow, &neghigh);
361 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
365 neg_double (l1, h1, &neglow, &neghigh);
366 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
368 return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
371 /* Shift the doubleword integer in L1, H1 left by COUNT places
372 keeping only PREC bits of result.
373 Shift right if COUNT is negative.
374 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
375 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
378 lshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
379 HOST_WIDE_INT count, unsigned int prec,
380 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv, int arith)
382 unsigned HOST_WIDE_INT signmask;
386 rshift_double (l1, h1, -count, prec, lv, hv, arith);
390 if (SHIFT_COUNT_TRUNCATED)
393 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
395 /* Shifting by the host word size is undefined according to the
396 ANSI standard, so we must handle this as a special case. */
400 else if (count >= HOST_BITS_PER_WIDE_INT)
402 *hv = l1 << (count - HOST_BITS_PER_WIDE_INT);
407 *hv = (((unsigned HOST_WIDE_INT) h1 << count)
408 | (l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
412 /* Sign extend all bits that are beyond the precision. */
414 signmask = -((prec > HOST_BITS_PER_WIDE_INT
415 ? ((unsigned HOST_WIDE_INT) *hv
416 >> (prec - HOST_BITS_PER_WIDE_INT - 1))
417 : (*lv >> (prec - 1))) & 1);
419 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
421 else if (prec >= HOST_BITS_PER_WIDE_INT)
423 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
424 *hv |= signmask << (prec - HOST_BITS_PER_WIDE_INT);
429 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
430 *lv |= signmask << prec;
434 /* Shift the doubleword integer in L1, H1 right by COUNT places
435 keeping only PREC bits of result. COUNT must be positive.
436 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
437 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
440 rshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
441 HOST_WIDE_INT count, unsigned int prec,
442 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
445 unsigned HOST_WIDE_INT signmask;
448 ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
451 if (SHIFT_COUNT_TRUNCATED)
454 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
456 /* Shifting by the host word size is undefined according to the
457 ANSI standard, so we must handle this as a special case. */
461 else if (count >= HOST_BITS_PER_WIDE_INT)
464 *lv = (unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT);
468 *hv = (unsigned HOST_WIDE_INT) h1 >> count;
470 | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
473 /* Zero / sign extend all bits that are beyond the precision. */
475 if (count >= (HOST_WIDE_INT)prec)
480 else if ((prec - count) >= 2 * HOST_BITS_PER_WIDE_INT)
482 else if ((prec - count) >= HOST_BITS_PER_WIDE_INT)
484 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - count - HOST_BITS_PER_WIDE_INT));
485 *hv |= signmask << (prec - count - HOST_BITS_PER_WIDE_INT);
490 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << (prec - count));
491 *lv |= signmask << (prec - count);
495 /* Rotate the doubleword integer in L1, H1 left by COUNT places
496 keeping only PREC bits of result.
497 Rotate right if COUNT is negative.
498 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
501 lrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
502 HOST_WIDE_INT count, unsigned int prec,
503 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
505 unsigned HOST_WIDE_INT s1l, s2l;
506 HOST_WIDE_INT s1h, s2h;
512 lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
513 rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
518 /* Rotate the doubleword integer in L1, H1 left by COUNT places
519 keeping only PREC bits of result. COUNT must be positive.
520 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
523 rrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
524 HOST_WIDE_INT count, unsigned int prec,
525 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
527 unsigned HOST_WIDE_INT s1l, s2l;
528 HOST_WIDE_INT s1h, s2h;
534 rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
535 lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
540 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
541 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
542 CODE is a tree code for a kind of division, one of
543 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
545 It controls how the quotient is rounded to an integer.
546 Return nonzero if the operation overflows.
547 UNS nonzero says do unsigned division. */
550 div_and_round_double (enum tree_code code, int uns,
551 unsigned HOST_WIDE_INT lnum_orig, /* num == numerator == dividend */
552 HOST_WIDE_INT hnum_orig,
553 unsigned HOST_WIDE_INT lden_orig, /* den == denominator == divisor */
554 HOST_WIDE_INT hden_orig,
555 unsigned HOST_WIDE_INT *lquo,
556 HOST_WIDE_INT *hquo, unsigned HOST_WIDE_INT *lrem,
560 HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
561 HOST_WIDE_INT den[4], quo[4];
563 unsigned HOST_WIDE_INT work;
564 unsigned HOST_WIDE_INT carry = 0;
565 unsigned HOST_WIDE_INT lnum = lnum_orig;
566 HOST_WIDE_INT hnum = hnum_orig;
567 unsigned HOST_WIDE_INT lden = lden_orig;
568 HOST_WIDE_INT hden = hden_orig;
571 if (hden == 0 && lden == 0)
572 overflow = 1, lden = 1;
574 /* Calculate quotient sign and convert operands to unsigned. */
580 /* (minimum integer) / (-1) is the only overflow case. */
581 if (neg_double (lnum, hnum, &lnum, &hnum)
582 && ((HOST_WIDE_INT) lden & hden) == -1)
588 neg_double (lden, hden, &lden, &hden);
592 if (hnum == 0 && hden == 0)
593 { /* single precision */
595 /* This unsigned division rounds toward zero. */
601 { /* trivial case: dividend < divisor */
602 /* hden != 0 already checked. */
609 memset (quo, 0, sizeof quo);
611 memset (num, 0, sizeof num); /* to zero 9th element */
612 memset (den, 0, sizeof den);
614 encode (num, lnum, hnum);
615 encode (den, lden, hden);
617 /* Special code for when the divisor < BASE. */
618 if (hden == 0 && lden < (unsigned HOST_WIDE_INT) BASE)
620 /* hnum != 0 already checked. */
621 for (i = 4 - 1; i >= 0; i--)
623 work = num[i] + carry * BASE;
624 quo[i] = work / lden;
630 /* Full double precision division,
631 with thanks to Don Knuth's "Seminumerical Algorithms". */
632 int num_hi_sig, den_hi_sig;
633 unsigned HOST_WIDE_INT quo_est, scale;
635 /* Find the highest nonzero divisor digit. */
636 for (i = 4 - 1;; i--)
643 /* Insure that the first digit of the divisor is at least BASE/2.
644 This is required by the quotient digit estimation algorithm. */
646 scale = BASE / (den[den_hi_sig] + 1);
648 { /* scale divisor and dividend */
650 for (i = 0; i <= 4 - 1; i++)
652 work = (num[i] * scale) + carry;
653 num[i] = LOWPART (work);
654 carry = HIGHPART (work);
659 for (i = 0; i <= 4 - 1; i++)
661 work = (den[i] * scale) + carry;
662 den[i] = LOWPART (work);
663 carry = HIGHPART (work);
664 if (den[i] != 0) den_hi_sig = i;
671 for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--)
673 /* Guess the next quotient digit, quo_est, by dividing the first
674 two remaining dividend digits by the high order quotient digit.
675 quo_est is never low and is at most 2 high. */
676 unsigned HOST_WIDE_INT tmp;
678 num_hi_sig = i + den_hi_sig + 1;
679 work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
680 if (num[num_hi_sig] != den[den_hi_sig])
681 quo_est = work / den[den_hi_sig];
685 /* Refine quo_est so it's usually correct, and at most one high. */
686 tmp = work - quo_est * den[den_hi_sig];
688 && (den[den_hi_sig - 1] * quo_est
689 > (tmp * BASE + num[num_hi_sig - 2])))
692 /* Try QUO_EST as the quotient digit, by multiplying the
693 divisor by QUO_EST and subtracting from the remaining dividend.
694 Keep in mind that QUO_EST is the I - 1st digit. */
697 for (j = 0; j <= den_hi_sig; j++)
699 work = quo_est * den[j] + carry;
700 carry = HIGHPART (work);
701 work = num[i + j] - LOWPART (work);
702 num[i + j] = LOWPART (work);
703 carry += HIGHPART (work) != 0;
706 /* If quo_est was high by one, then num[i] went negative and
707 we need to correct things. */
708 if (num[num_hi_sig] < (HOST_WIDE_INT) carry)
711 carry = 0; /* add divisor back in */
712 for (j = 0; j <= den_hi_sig; j++)
714 work = num[i + j] + den[j] + carry;
715 carry = HIGHPART (work);
716 num[i + j] = LOWPART (work);
719 num [num_hi_sig] += carry;
722 /* Store the quotient digit. */
727 decode (quo, lquo, hquo);
730 /* If result is negative, make it so. */
732 neg_double (*lquo, *hquo, lquo, hquo);
734 /* Compute trial remainder: rem = num - (quo * den) */
735 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
736 neg_double (*lrem, *hrem, lrem, hrem);
737 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
742 case TRUNC_MOD_EXPR: /* round toward zero */
743 case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
747 case FLOOR_MOD_EXPR: /* round toward negative infinity */
748 if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
751 add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
759 case CEIL_MOD_EXPR: /* round toward positive infinity */
760 if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
762 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
770 case ROUND_MOD_EXPR: /* round to closest integer */
772 unsigned HOST_WIDE_INT labs_rem = *lrem;
773 HOST_WIDE_INT habs_rem = *hrem;
774 unsigned HOST_WIDE_INT labs_den = lden, ltwice;
775 HOST_WIDE_INT habs_den = hden, htwice;
777 /* Get absolute values. */
779 neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
781 neg_double (lden, hden, &labs_den, &habs_den);
783 /* If (2 * abs (lrem) >= abs (lden)) */
784 mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
785 labs_rem, habs_rem, <wice, &htwice);
787 if (((unsigned HOST_WIDE_INT) habs_den
788 < (unsigned HOST_WIDE_INT) htwice)
789 || (((unsigned HOST_WIDE_INT) habs_den
790 == (unsigned HOST_WIDE_INT) htwice)
791 && (labs_den < ltwice)))
795 add_double (*lquo, *hquo,
796 (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
799 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
811 /* Compute true remainder: rem = num - (quo * den) */
812 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
813 neg_double (*lrem, *hrem, lrem, hrem);
814 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
818 /* Return true if built-in mathematical function specified by CODE
819 preserves the sign of it argument, i.e. -f(x) == f(-x). */
822 negate_mathfn_p (enum built_in_function code)
846 /* Determine whether an expression T can be cheaply negated using
847 the function negate_expr. */
850 negate_expr_p (tree t)
852 unsigned HOST_WIDE_INT val;
859 type = TREE_TYPE (t);
862 switch (TREE_CODE (t))
865 if (TYPE_UNSIGNED (type) || ! flag_trapv)
868 /* Check that -CST will not overflow type. */
869 prec = TYPE_PRECISION (type);
870 if (prec > HOST_BITS_PER_WIDE_INT)
872 if (TREE_INT_CST_LOW (t) != 0)
874 prec -= HOST_BITS_PER_WIDE_INT;
875 val = TREE_INT_CST_HIGH (t);
878 val = TREE_INT_CST_LOW (t);
879 if (prec < HOST_BITS_PER_WIDE_INT)
880 val &= ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
881 return val != ((unsigned HOST_WIDE_INT) 1 << (prec - 1));
888 return negate_expr_p (TREE_REALPART (t))
889 && negate_expr_p (TREE_IMAGPART (t));
892 if (FLOAT_TYPE_P (type) && !flag_unsafe_math_optimizations)
894 /* -(A + B) -> (-B) - A. */
895 if (negate_expr_p (TREE_OPERAND (t, 1))
896 && reorder_operands_p (TREE_OPERAND (t, 0),
897 TREE_OPERAND (t, 1)))
899 /* -(A + B) -> (-A) - B. */
900 return negate_expr_p (TREE_OPERAND (t, 0));
903 /* We can't turn -(A-B) into B-A when we honor signed zeros. */
904 return (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
905 && reorder_operands_p (TREE_OPERAND (t, 0),
906 TREE_OPERAND (t, 1));
909 if (TYPE_UNSIGNED (TREE_TYPE (t)))
915 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
916 return negate_expr_p (TREE_OPERAND (t, 1))
917 || negate_expr_p (TREE_OPERAND (t, 0));
921 /* Negate -((double)float) as (double)(-float). */
922 if (TREE_CODE (type) == REAL_TYPE)
924 tree tem = strip_float_extensions (t);
926 return negate_expr_p (tem);
931 /* Negate -f(x) as f(-x). */
932 if (negate_mathfn_p (builtin_mathfn_code (t)))
933 return negate_expr_p (TREE_VALUE (TREE_OPERAND (t, 1)));
937 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
938 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
940 tree op1 = TREE_OPERAND (t, 1);
941 if (TREE_INT_CST_HIGH (op1) == 0
942 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
943 == TREE_INT_CST_LOW (op1))
954 /* Given T, an expression, return the negation of T. Allow for T to be
955 null, in which case return null. */
966 type = TREE_TYPE (t);
969 switch (TREE_CODE (t))
972 tem = fold_negate_const (t, type);
973 if (! TREE_OVERFLOW (tem)
974 || TYPE_UNSIGNED (type)
980 tem = fold_negate_const (t, type);
981 /* Two's complement FP formats, such as c4x, may overflow. */
982 if (! TREE_OVERFLOW (tem) || ! flag_trapping_math)
983 return fold_convert (type, tem);
988 tree rpart = negate_expr (TREE_REALPART (t));
989 tree ipart = negate_expr (TREE_IMAGPART (t));
991 if ((TREE_CODE (rpart) == REAL_CST
992 && TREE_CODE (ipart) == REAL_CST)
993 || (TREE_CODE (rpart) == INTEGER_CST
994 && TREE_CODE (ipart) == INTEGER_CST))
995 return build_complex (type, rpart, ipart);
1000 return fold_convert (type, TREE_OPERAND (t, 0));
1003 if (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
1005 /* -(A + B) -> (-B) - A. */
1006 if (negate_expr_p (TREE_OPERAND (t, 1))
1007 && reorder_operands_p (TREE_OPERAND (t, 0),
1008 TREE_OPERAND (t, 1)))
1010 tem = negate_expr (TREE_OPERAND (t, 1));
1011 tem = fold (build2 (MINUS_EXPR, TREE_TYPE (t),
1012 tem, TREE_OPERAND (t, 0)));
1013 return fold_convert (type, tem);
1016 /* -(A + B) -> (-A) - B. */
1017 if (negate_expr_p (TREE_OPERAND (t, 0)))
1019 tem = negate_expr (TREE_OPERAND (t, 0));
1020 tem = fold (build2 (MINUS_EXPR, TREE_TYPE (t),
1021 tem, TREE_OPERAND (t, 1)));
1022 return fold_convert (type, tem);
1028 /* - (A - B) -> B - A */
1029 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
1030 && reorder_operands_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1)))
1031 return fold_convert (type,
1032 fold (build2 (MINUS_EXPR, TREE_TYPE (t),
1033 TREE_OPERAND (t, 1),
1034 TREE_OPERAND (t, 0))));
1038 if (TYPE_UNSIGNED (TREE_TYPE (t)))
1044 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
1046 tem = TREE_OPERAND (t, 1);
1047 if (negate_expr_p (tem))
1048 return fold_convert (type,
1049 fold (build2 (TREE_CODE (t), TREE_TYPE (t),
1050 TREE_OPERAND (t, 0),
1051 negate_expr (tem))));
1052 tem = TREE_OPERAND (t, 0);
1053 if (negate_expr_p (tem))
1054 return fold_convert (type,
1055 fold (build2 (TREE_CODE (t), TREE_TYPE (t),
1057 TREE_OPERAND (t, 1))));
1062 /* Convert -((double)float) into (double)(-float). */
1063 if (TREE_CODE (type) == REAL_TYPE)
1065 tem = strip_float_extensions (t);
1066 if (tem != t && negate_expr_p (tem))
1067 return fold_convert (type, negate_expr (tem));
1072 /* Negate -f(x) as f(-x). */
1073 if (negate_mathfn_p (builtin_mathfn_code (t))
1074 && negate_expr_p (TREE_VALUE (TREE_OPERAND (t, 1))))
1076 tree fndecl, arg, arglist;
1078 fndecl = get_callee_fndecl (t);
1079 arg = negate_expr (TREE_VALUE (TREE_OPERAND (t, 1)));
1080 arglist = build_tree_list (NULL_TREE, arg);
1081 return build_function_call_expr (fndecl, arglist);
1086 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1087 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
1089 tree op1 = TREE_OPERAND (t, 1);
1090 if (TREE_INT_CST_HIGH (op1) == 0
1091 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
1092 == TREE_INT_CST_LOW (op1))
1094 tree ntype = TYPE_UNSIGNED (type)
1095 ? lang_hooks.types.signed_type (type)
1096 : lang_hooks.types.unsigned_type (type);
1097 tree temp = fold_convert (ntype, TREE_OPERAND (t, 0));
1098 temp = fold (build2 (RSHIFT_EXPR, ntype, temp, op1));
1099 return fold_convert (type, temp);
1108 tem = fold (build1 (NEGATE_EXPR, TREE_TYPE (t), t));
1109 return fold_convert (type, tem);
1112 /* Split a tree IN into a constant, literal and variable parts that could be
1113 combined with CODE to make IN. "constant" means an expression with
1114 TREE_CONSTANT but that isn't an actual constant. CODE must be a
1115 commutative arithmetic operation. Store the constant part into *CONP,
1116 the literal in *LITP and return the variable part. If a part isn't
1117 present, set it to null. If the tree does not decompose in this way,
1118 return the entire tree as the variable part and the other parts as null.
1120 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
1121 case, we negate an operand that was subtracted. Except if it is a
1122 literal for which we use *MINUS_LITP instead.
1124 If NEGATE_P is true, we are negating all of IN, again except a literal
1125 for which we use *MINUS_LITP instead.
1127 If IN is itself a literal or constant, return it as appropriate.
1129 Note that we do not guarantee that any of the three values will be the
1130 same type as IN, but they will have the same signedness and mode. */
1133 split_tree (tree in, enum tree_code code, tree *conp, tree *litp,
1134 tree *minus_litp, int negate_p)
1142 /* Strip any conversions that don't change the machine mode or signedness. */
1143 STRIP_SIGN_NOPS (in);
1145 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST)
1147 else if (TREE_CODE (in) == code
1148 || (! FLOAT_TYPE_P (TREE_TYPE (in))
1149 /* We can associate addition and subtraction together (even
1150 though the C standard doesn't say so) for integers because
1151 the value is not affected. For reals, the value might be
1152 affected, so we can't. */
1153 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
1154 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
1156 tree op0 = TREE_OPERAND (in, 0);
1157 tree op1 = TREE_OPERAND (in, 1);
1158 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
1159 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
1161 /* First see if either of the operands is a literal, then a constant. */
1162 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
1163 *litp = op0, op0 = 0;
1164 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST)
1165 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
1167 if (op0 != 0 && TREE_CONSTANT (op0))
1168 *conp = op0, op0 = 0;
1169 else if (op1 != 0 && TREE_CONSTANT (op1))
1170 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
1172 /* If we haven't dealt with either operand, this is not a case we can
1173 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1174 if (op0 != 0 && op1 != 0)
1179 var = op1, neg_var_p = neg1_p;
1181 /* Now do any needed negations. */
1183 *minus_litp = *litp, *litp = 0;
1185 *conp = negate_expr (*conp);
1187 var = negate_expr (var);
1189 else if (TREE_CONSTANT (in))
1197 *minus_litp = *litp, *litp = 0;
1198 else if (*minus_litp)
1199 *litp = *minus_litp, *minus_litp = 0;
1200 *conp = negate_expr (*conp);
1201 var = negate_expr (var);
1207 /* Re-associate trees split by the above function. T1 and T2 are either
1208 expressions to associate or null. Return the new expression, if any. If
1209 we build an operation, do it in TYPE and with CODE. */
1212 associate_trees (tree t1, tree t2, enum tree_code code, tree type)
1219 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1220 try to fold this since we will have infinite recursion. But do
1221 deal with any NEGATE_EXPRs. */
1222 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
1223 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1225 if (code == PLUS_EXPR)
1227 if (TREE_CODE (t1) == NEGATE_EXPR)
1228 return build2 (MINUS_EXPR, type, fold_convert (type, t2),
1229 fold_convert (type, TREE_OPERAND (t1, 0)));
1230 else if (TREE_CODE (t2) == NEGATE_EXPR)
1231 return build2 (MINUS_EXPR, type, fold_convert (type, t1),
1232 fold_convert (type, TREE_OPERAND (t2, 0)));
1234 return build2 (code, type, fold_convert (type, t1),
1235 fold_convert (type, t2));
1238 return fold (build2 (code, type, fold_convert (type, t1),
1239 fold_convert (type, t2)));
1242 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1243 to produce a new constant.
1245 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1248 int_const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1250 unsigned HOST_WIDE_INT int1l, int2l;
1251 HOST_WIDE_INT int1h, int2h;
1252 unsigned HOST_WIDE_INT low;
1254 unsigned HOST_WIDE_INT garbagel;
1255 HOST_WIDE_INT garbageh;
1257 tree type = TREE_TYPE (arg1);
1258 int uns = TYPE_UNSIGNED (type);
1260 = (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type));
1262 int no_overflow = 0;
1264 int1l = TREE_INT_CST_LOW (arg1);
1265 int1h = TREE_INT_CST_HIGH (arg1);
1266 int2l = TREE_INT_CST_LOW (arg2);
1267 int2h = TREE_INT_CST_HIGH (arg2);
1272 low = int1l | int2l, hi = int1h | int2h;
1276 low = int1l ^ int2l, hi = int1h ^ int2h;
1280 low = int1l & int2l, hi = int1h & int2h;
1286 /* It's unclear from the C standard whether shifts can overflow.
1287 The following code ignores overflow; perhaps a C standard
1288 interpretation ruling is needed. */
1289 lshift_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1297 lrotate_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1302 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1306 neg_double (int2l, int2h, &low, &hi);
1307 add_double (int1l, int1h, low, hi, &low, &hi);
1308 overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
1312 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1315 case TRUNC_DIV_EXPR:
1316 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1317 case EXACT_DIV_EXPR:
1318 /* This is a shortcut for a common special case. */
1319 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1320 && ! TREE_CONSTANT_OVERFLOW (arg1)
1321 && ! TREE_CONSTANT_OVERFLOW (arg2)
1322 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1324 if (code == CEIL_DIV_EXPR)
1327 low = int1l / int2l, hi = 0;
1331 /* ... fall through ... */
1333 case ROUND_DIV_EXPR:
1334 if (int2h == 0 && int2l == 1)
1336 low = int1l, hi = int1h;
1339 if (int1l == int2l && int1h == int2h
1340 && ! (int1l == 0 && int1h == 0))
1345 overflow = div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
1346 &low, &hi, &garbagel, &garbageh);
1349 case TRUNC_MOD_EXPR:
1350 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1351 /* This is a shortcut for a common special case. */
1352 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1353 && ! TREE_CONSTANT_OVERFLOW (arg1)
1354 && ! TREE_CONSTANT_OVERFLOW (arg2)
1355 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1357 if (code == CEIL_MOD_EXPR)
1359 low = int1l % int2l, hi = 0;
1363 /* ... fall through ... */
1365 case ROUND_MOD_EXPR:
1366 overflow = div_and_round_double (code, uns,
1367 int1l, int1h, int2l, int2h,
1368 &garbagel, &garbageh, &low, &hi);
1374 low = (((unsigned HOST_WIDE_INT) int1h
1375 < (unsigned HOST_WIDE_INT) int2h)
1376 || (((unsigned HOST_WIDE_INT) int1h
1377 == (unsigned HOST_WIDE_INT) int2h)
1380 low = (int1h < int2h
1381 || (int1h == int2h && int1l < int2l));
1383 if (low == (code == MIN_EXPR))
1384 low = int1l, hi = int1h;
1386 low = int2l, hi = int2h;
1393 /* If this is for a sizetype, can be represented as one (signed)
1394 HOST_WIDE_INT word, and doesn't overflow, use size_int since it caches
1397 && ((hi == 0 && (HOST_WIDE_INT) low >= 0)
1398 || (hi == -1 && (HOST_WIDE_INT) low < 0))
1399 && overflow == 0 && ! TREE_OVERFLOW (arg1) && ! TREE_OVERFLOW (arg2))
1400 return size_int_type_wide (low, type);
1403 t = build_int_2 (low, hi);
1404 TREE_TYPE (t) = TREE_TYPE (arg1);
1409 ? (!uns || is_sizetype) && overflow
1410 : (force_fit_type (t, (!uns || is_sizetype) && overflow)
1412 | TREE_OVERFLOW (arg1)
1413 | TREE_OVERFLOW (arg2));
1415 /* If we're doing a size calculation, unsigned arithmetic does overflow.
1416 So check if force_fit_type truncated the value. */
1418 && ! TREE_OVERFLOW (t)
1419 && (TREE_INT_CST_HIGH (t) != hi
1420 || TREE_INT_CST_LOW (t) != low))
1421 TREE_OVERFLOW (t) = 1;
1423 TREE_CONSTANT_OVERFLOW (t) = (TREE_OVERFLOW (t)
1424 | TREE_CONSTANT_OVERFLOW (arg1)
1425 | TREE_CONSTANT_OVERFLOW (arg2));
1429 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1430 constant. We assume ARG1 and ARG2 have the same data type, or at least
1431 are the same kind of constant and the same machine mode.
1433 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1436 const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1441 if (TREE_CODE (arg1) == INTEGER_CST)
1442 return int_const_binop (code, arg1, arg2, notrunc);
1444 if (TREE_CODE (arg1) == REAL_CST)
1446 enum machine_mode mode;
1449 REAL_VALUE_TYPE value;
1452 d1 = TREE_REAL_CST (arg1);
1453 d2 = TREE_REAL_CST (arg2);
1455 type = TREE_TYPE (arg1);
1456 mode = TYPE_MODE (type);
1458 /* Don't perform operation if we honor signaling NaNs and
1459 either operand is a NaN. */
1460 if (HONOR_SNANS (mode)
1461 && (REAL_VALUE_ISNAN (d1) || REAL_VALUE_ISNAN (d2)))
1464 /* Don't perform operation if it would raise a division
1465 by zero exception. */
1466 if (code == RDIV_EXPR
1467 && REAL_VALUES_EQUAL (d2, dconst0)
1468 && (flag_trapping_math || ! MODE_HAS_INFINITIES (mode)))
1471 /* If either operand is a NaN, just return it. Otherwise, set up
1472 for floating-point trap; we return an overflow. */
1473 if (REAL_VALUE_ISNAN (d1))
1475 else if (REAL_VALUE_ISNAN (d2))
1478 REAL_ARITHMETIC (value, code, d1, d2);
1480 t = build_real (type, real_value_truncate (mode, value));
1483 = (force_fit_type (t, 0)
1484 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
1485 TREE_CONSTANT_OVERFLOW (t)
1487 | TREE_CONSTANT_OVERFLOW (arg1)
1488 | TREE_CONSTANT_OVERFLOW (arg2);
1491 if (TREE_CODE (arg1) == COMPLEX_CST)
1493 tree type = TREE_TYPE (arg1);
1494 tree r1 = TREE_REALPART (arg1);
1495 tree i1 = TREE_IMAGPART (arg1);
1496 tree r2 = TREE_REALPART (arg2);
1497 tree i2 = TREE_IMAGPART (arg2);
1503 t = build_complex (type,
1504 const_binop (PLUS_EXPR, r1, r2, notrunc),
1505 const_binop (PLUS_EXPR, i1, i2, notrunc));
1509 t = build_complex (type,
1510 const_binop (MINUS_EXPR, r1, r2, notrunc),
1511 const_binop (MINUS_EXPR, i1, i2, notrunc));
1515 t = build_complex (type,
1516 const_binop (MINUS_EXPR,
1517 const_binop (MULT_EXPR,
1519 const_binop (MULT_EXPR,
1522 const_binop (PLUS_EXPR,
1523 const_binop (MULT_EXPR,
1525 const_binop (MULT_EXPR,
1533 = const_binop (PLUS_EXPR,
1534 const_binop (MULT_EXPR, r2, r2, notrunc),
1535 const_binop (MULT_EXPR, i2, i2, notrunc),
1538 t = build_complex (type,
1540 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1541 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1542 const_binop (PLUS_EXPR,
1543 const_binop (MULT_EXPR, r1, r2,
1545 const_binop (MULT_EXPR, i1, i2,
1548 magsquared, notrunc),
1550 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1551 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1552 const_binop (MINUS_EXPR,
1553 const_binop (MULT_EXPR, i1, r2,
1555 const_binop (MULT_EXPR, r1, i2,
1558 magsquared, notrunc));
1570 /* These are the hash table functions for the hash table of INTEGER_CST
1571 nodes of a sizetype. */
1573 /* Return the hash code code X, an INTEGER_CST. */
1576 size_htab_hash (const void *x)
1580 return (TREE_INT_CST_HIGH (t) ^ TREE_INT_CST_LOW (t)
1581 ^ htab_hash_pointer (TREE_TYPE (t))
1582 ^ (TREE_OVERFLOW (t) << 20));
1585 /* Return nonzero if the value represented by *X (an INTEGER_CST tree node)
1586 is the same as that given by *Y, which is the same. */
1589 size_htab_eq (const void *x, const void *y)
1594 return (TREE_INT_CST_HIGH (xt) == TREE_INT_CST_HIGH (yt)
1595 && TREE_INT_CST_LOW (xt) == TREE_INT_CST_LOW (yt)
1596 && TREE_TYPE (xt) == TREE_TYPE (yt)
1597 && TREE_OVERFLOW (xt) == TREE_OVERFLOW (yt));
1600 /* Return an INTEGER_CST with value whose low-order HOST_BITS_PER_WIDE_INT
1601 bits are given by NUMBER and of the sizetype represented by KIND. */
1604 size_int_wide (HOST_WIDE_INT number, enum size_type_kind kind)
1606 return size_int_type_wide (number, sizetype_tab[(int) kind]);
1609 /* Likewise, but the desired type is specified explicitly. */
1611 static GTY (()) tree new_const;
1612 static GTY ((if_marked ("ggc_marked_p"), param_is (union tree_node)))
1616 size_int_type_wide (HOST_WIDE_INT number, tree type)
1622 size_htab = htab_create_ggc (1024, size_htab_hash, size_htab_eq, NULL);
1623 new_const = make_node (INTEGER_CST);
1626 /* Adjust NEW_CONST to be the constant we want. If it's already in the
1627 hash table, we return the value from the hash table. Otherwise, we
1628 place that in the hash table and make a new node for the next time. */
1629 TREE_INT_CST_LOW (new_const) = number;
1630 TREE_INT_CST_HIGH (new_const) = number < 0 ? -1 : 0;
1631 TREE_TYPE (new_const) = type;
1632 TREE_OVERFLOW (new_const) = TREE_CONSTANT_OVERFLOW (new_const)
1633 = force_fit_type (new_const, 0);
1635 slot = htab_find_slot (size_htab, new_const, INSERT);
1641 new_const = make_node (INTEGER_CST);
1645 return (tree) *slot;
1648 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1649 is a tree code. The type of the result is taken from the operands.
1650 Both must be the same type integer type and it must be a size type.
1651 If the operands are constant, so is the result. */
1654 size_binop (enum tree_code code, tree arg0, tree arg1)
1656 tree type = TREE_TYPE (arg0);
1658 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1659 || type != TREE_TYPE (arg1))
1662 /* Handle the special case of two integer constants faster. */
1663 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1665 /* And some specific cases even faster than that. */
1666 if (code == PLUS_EXPR && integer_zerop (arg0))
1668 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1669 && integer_zerop (arg1))
1671 else if (code == MULT_EXPR && integer_onep (arg0))
1674 /* Handle general case of two integer constants. */
1675 return int_const_binop (code, arg0, arg1, 0);
1678 if (arg0 == error_mark_node || arg1 == error_mark_node)
1679 return error_mark_node;
1681 return fold (build2 (code, type, arg0, arg1));
1684 /* Given two values, either both of sizetype or both of bitsizetype,
1685 compute the difference between the two values. Return the value
1686 in signed type corresponding to the type of the operands. */
1689 size_diffop (tree arg0, tree arg1)
1691 tree type = TREE_TYPE (arg0);
1694 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1695 || type != TREE_TYPE (arg1))
1698 /* If the type is already signed, just do the simple thing. */
1699 if (!TYPE_UNSIGNED (type))
1700 return size_binop (MINUS_EXPR, arg0, arg1);
1702 ctype = (type == bitsizetype || type == ubitsizetype
1703 ? sbitsizetype : ssizetype);
1705 /* If either operand is not a constant, do the conversions to the signed
1706 type and subtract. The hardware will do the right thing with any
1707 overflow in the subtraction. */
1708 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
1709 return size_binop (MINUS_EXPR, fold_convert (ctype, arg0),
1710 fold_convert (ctype, arg1));
1712 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
1713 Otherwise, subtract the other way, convert to CTYPE (we know that can't
1714 overflow) and negate (which can't either). Special-case a result
1715 of zero while we're here. */
1716 if (tree_int_cst_equal (arg0, arg1))
1717 return fold_convert (ctype, integer_zero_node);
1718 else if (tree_int_cst_lt (arg1, arg0))
1719 return fold_convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
1721 return size_binop (MINUS_EXPR, fold_convert (ctype, integer_zero_node),
1722 fold_convert (ctype, size_binop (MINUS_EXPR,
1727 /* Attempt to fold type conversion operation CODE of expression ARG1 to
1728 type TYPE. If no simplification can be done return NULL_TREE. */
1731 fold_convert_const (enum tree_code code, tree type, tree arg1)
1736 if (TREE_TYPE (arg1) == type)
1739 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
1741 if (TREE_CODE (arg1) == INTEGER_CST)
1743 /* If we would build a constant wider than GCC supports,
1744 leave the conversion unfolded. */
1745 if (TYPE_PRECISION (type) > 2 * HOST_BITS_PER_WIDE_INT)
1748 /* If we are trying to make a sizetype for a small integer, use
1749 size_int to pick up cached types to reduce duplicate nodes. */
1750 if (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type)
1751 && !TREE_CONSTANT_OVERFLOW (arg1)
1752 && compare_tree_int (arg1, 10000) < 0)
1753 return size_int_type_wide (TREE_INT_CST_LOW (arg1), type);
1755 /* Given an integer constant, make new constant with new type,
1756 appropriately sign-extended or truncated. */
1757 t = build_int_2 (TREE_INT_CST_LOW (arg1),
1758 TREE_INT_CST_HIGH (arg1));
1759 TREE_TYPE (t) = type;
1760 /* Indicate an overflow if (1) ARG1 already overflowed,
1761 or (2) force_fit_type indicates an overflow.
1762 Tell force_fit_type that an overflow has already occurred
1763 if ARG1 is a too-large unsigned value and T is signed.
1764 But don't indicate an overflow if converting a pointer. */
1766 = ((force_fit_type (t,
1767 (TREE_INT_CST_HIGH (arg1) < 0
1768 && (TYPE_UNSIGNED (type)
1769 < TYPE_UNSIGNED (TREE_TYPE (arg1)))))
1770 && ! POINTER_TYPE_P (TREE_TYPE (arg1)))
1771 || TREE_OVERFLOW (arg1));
1772 TREE_CONSTANT_OVERFLOW (t)
1773 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1776 else if (TREE_CODE (arg1) == REAL_CST)
1778 /* The following code implements the floating point to integer
1779 conversion rules required by the Java Language Specification,
1780 that IEEE NaNs are mapped to zero and values that overflow
1781 the target precision saturate, i.e. values greater than
1782 INT_MAX are mapped to INT_MAX, and values less than INT_MIN
1783 are mapped to INT_MIN. These semantics are allowed by the
1784 C and C++ standards that simply state that the behavior of
1785 FP-to-integer conversion is unspecified upon overflow. */
1787 HOST_WIDE_INT high, low;
1790 REAL_VALUE_TYPE x = TREE_REAL_CST (arg1);
1794 case FIX_TRUNC_EXPR:
1795 real_trunc (&r, VOIDmode, &x);
1799 real_ceil (&r, VOIDmode, &x);
1802 case FIX_FLOOR_EXPR:
1803 real_floor (&r, VOIDmode, &x);
1806 case FIX_ROUND_EXPR:
1807 real_round (&r, VOIDmode, &x);
1814 /* If R is NaN, return zero and show we have an overflow. */
1815 if (REAL_VALUE_ISNAN (r))
1822 /* See if R is less than the lower bound or greater than the
1827 tree lt = TYPE_MIN_VALUE (type);
1828 REAL_VALUE_TYPE l = real_value_from_int_cst (NULL_TREE, lt);
1829 if (REAL_VALUES_LESS (r, l))
1832 high = TREE_INT_CST_HIGH (lt);
1833 low = TREE_INT_CST_LOW (lt);
1839 tree ut = TYPE_MAX_VALUE (type);
1842 REAL_VALUE_TYPE u = real_value_from_int_cst (NULL_TREE, ut);
1843 if (REAL_VALUES_LESS (u, r))
1846 high = TREE_INT_CST_HIGH (ut);
1847 low = TREE_INT_CST_LOW (ut);
1853 REAL_VALUE_TO_INT (&low, &high, r);
1855 t = build_int_2 (low, high);
1856 TREE_TYPE (t) = type;
1858 = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
1859 TREE_CONSTANT_OVERFLOW (t)
1860 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1864 else if (TREE_CODE (type) == REAL_TYPE)
1866 if (TREE_CODE (arg1) == INTEGER_CST)
1867 return build_real_from_int_cst (type, arg1);
1868 if (TREE_CODE (arg1) == REAL_CST)
1870 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
1872 /* We make a copy of ARG1 so that we don't modify an
1873 existing constant tree. */
1874 t = copy_node (arg1);
1875 TREE_TYPE (t) = type;
1879 t = build_real (type,
1880 real_value_truncate (TYPE_MODE (type),
1881 TREE_REAL_CST (arg1)));
1884 = TREE_OVERFLOW (arg1) | force_fit_type (t, 0);
1885 TREE_CONSTANT_OVERFLOW (t)
1886 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1893 /* Convert expression ARG to type TYPE. Used by the middle-end for
1894 simple conversions in preference to calling the front-end's convert. */
1897 fold_convert (tree type, tree arg)
1899 tree orig = TREE_TYPE (arg);
1905 if (TREE_CODE (arg) == ERROR_MARK
1906 || TREE_CODE (type) == ERROR_MARK
1907 || TREE_CODE (orig) == ERROR_MARK)
1908 return error_mark_node;
1910 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig))
1911 return fold (build1 (NOP_EXPR, type, arg));
1913 if (INTEGRAL_TYPE_P (type) || POINTER_TYPE_P (type)
1914 || TREE_CODE (type) == OFFSET_TYPE)
1916 if (TREE_CODE (arg) == INTEGER_CST)
1918 tem = fold_convert_const (NOP_EXPR, type, arg);
1919 if (tem != NULL_TREE)
1922 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
1923 || TREE_CODE (orig) == OFFSET_TYPE)
1924 return fold (build1 (NOP_EXPR, type, arg));
1925 if (TREE_CODE (orig) == COMPLEX_TYPE)
1927 tem = fold (build1 (REALPART_EXPR, TREE_TYPE (orig), arg));
1928 return fold_convert (type, tem);
1930 if (TREE_CODE (orig) == VECTOR_TYPE
1931 && GET_MODE_SIZE (TYPE_MODE (type))
1932 == GET_MODE_SIZE (TYPE_MODE (orig)))
1933 return fold (build1 (NOP_EXPR, type, arg));
1935 else if (TREE_CODE (type) == REAL_TYPE)
1937 if (TREE_CODE (arg) == INTEGER_CST)
1939 tem = fold_convert_const (FLOAT_EXPR, type, arg);
1940 if (tem != NULL_TREE)
1943 else if (TREE_CODE (arg) == REAL_CST)
1945 tem = fold_convert_const (NOP_EXPR, type, arg);
1946 if (tem != NULL_TREE)
1950 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig))
1951 return fold (build1 (FLOAT_EXPR, type, arg));
1952 if (TREE_CODE (orig) == REAL_TYPE)
1953 return fold (build1 (flag_float_store ? CONVERT_EXPR : NOP_EXPR,
1955 if (TREE_CODE (orig) == COMPLEX_TYPE)
1957 tem = fold (build1 (REALPART_EXPR, TREE_TYPE (orig), arg));
1958 return fold_convert (type, tem);
1961 else if (TREE_CODE (type) == COMPLEX_TYPE)
1963 if (INTEGRAL_TYPE_P (orig)
1964 || POINTER_TYPE_P (orig)
1965 || TREE_CODE (orig) == REAL_TYPE)
1966 return build2 (COMPLEX_EXPR, type,
1967 fold_convert (TREE_TYPE (type), arg),
1968 fold_convert (TREE_TYPE (type), integer_zero_node));
1969 if (TREE_CODE (orig) == COMPLEX_TYPE)
1973 if (TREE_CODE (arg) == COMPLEX_EXPR)
1975 rpart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 0));
1976 ipart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 1));
1977 return fold (build2 (COMPLEX_EXPR, type, rpart, ipart));
1980 arg = save_expr (arg);
1981 rpart = fold (build1 (REALPART_EXPR, TREE_TYPE (orig), arg));
1982 ipart = fold (build1 (IMAGPART_EXPR, TREE_TYPE (orig), arg));
1983 rpart = fold_convert (TREE_TYPE (type), rpart);
1984 ipart = fold_convert (TREE_TYPE (type), ipart);
1985 return fold (build2 (COMPLEX_EXPR, type, rpart, ipart));
1988 else if (TREE_CODE (type) == VECTOR_TYPE)
1990 if ((INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig))
1991 && GET_MODE_SIZE (TYPE_MODE (type))
1992 == GET_MODE_SIZE (TYPE_MODE (orig)))
1993 return fold (build1 (NOP_EXPR, type, arg));
1994 if (TREE_CODE (orig) == VECTOR_TYPE
1995 && GET_MODE_SIZE (TYPE_MODE (type))
1996 == GET_MODE_SIZE (TYPE_MODE (orig)))
1997 return fold (build1 (NOP_EXPR, type, arg));
1999 else if (VOID_TYPE_P (type))
2000 return fold (build1 (CONVERT_EXPR, type, arg));
2004 /* Return an expr equal to X but certainly not valid as an lvalue. */
2009 /* We only need to wrap lvalue tree codes. */
2010 switch (TREE_CODE (x))
2024 case ARRAY_RANGE_REF:
2029 case PREINCREMENT_EXPR:
2030 case PREDECREMENT_EXPR:
2033 case TRY_CATCH_EXPR:
2034 case WITH_CLEANUP_EXPR:
2046 /* Assume the worst for front-end tree codes. */
2047 if ((int)TREE_CODE (x) >= NUM_TREE_CODES)
2051 return build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
2054 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
2055 Zero means allow extended lvalues. */
2057 int pedantic_lvalues;
2059 /* When pedantic, return an expr equal to X but certainly not valid as a
2060 pedantic lvalue. Otherwise, return X. */
2063 pedantic_non_lvalue (tree x)
2065 if (pedantic_lvalues)
2066 return non_lvalue (x);
2071 /* Given a tree comparison code, return the code that is the logical inverse
2072 of the given code. It is not safe to do this for floating-point
2073 comparisons, except for NE_EXPR and EQ_EXPR, so we receive a machine mode
2074 as well: if reversing the comparison is unsafe, return ERROR_MARK. */
2076 static enum tree_code
2077 invert_tree_comparison (enum tree_code code, bool honor_nans)
2079 if (honor_nans && flag_trapping_math)
2089 return honor_nans ? UNLE_EXPR : LE_EXPR;
2091 return honor_nans ? UNLT_EXPR : LT_EXPR;
2093 return honor_nans ? UNGE_EXPR : GE_EXPR;
2095 return honor_nans ? UNGT_EXPR : GT_EXPR;
2109 return UNORDERED_EXPR;
2110 case UNORDERED_EXPR:
2111 return ORDERED_EXPR;
2117 /* Similar, but return the comparison that results if the operands are
2118 swapped. This is safe for floating-point. */
2121 swap_tree_comparison (enum tree_code code)
2142 /* Convert a comparison tree code from an enum tree_code representation
2143 into a compcode bit-based encoding. This function is the inverse of
2144 compcode_to_comparison. */
2146 static enum comparison_code
2147 comparison_to_compcode (enum tree_code code)
2164 return COMPCODE_ORD;
2165 case UNORDERED_EXPR:
2166 return COMPCODE_UNORD;
2168 return COMPCODE_UNLT;
2170 return COMPCODE_UNEQ;
2172 return COMPCODE_UNLE;
2174 return COMPCODE_UNGT;
2176 return COMPCODE_LTGT;
2178 return COMPCODE_UNGE;
2184 /* Convert a compcode bit-based encoding of a comparison operator back
2185 to GCC's enum tree_code representation. This function is the
2186 inverse of comparison_to_compcode. */
2188 static enum tree_code
2189 compcode_to_comparison (enum comparison_code code)
2206 return ORDERED_EXPR;
2207 case COMPCODE_UNORD:
2208 return UNORDERED_EXPR;
2226 /* Return a tree for the comparison which is the combination of
2227 doing the AND or OR (depending on CODE) of the two operations LCODE
2228 and RCODE on the identical operands LL_ARG and LR_ARG. Take into account
2229 the possibility of trapping if the mode has NaNs, and return NULL_TREE
2230 if this makes the transformation invalid. */
2233 combine_comparisons (enum tree_code code, enum tree_code lcode,
2234 enum tree_code rcode, tree truth_type,
2235 tree ll_arg, tree lr_arg)
2237 bool honor_nans = HONOR_NANS (TYPE_MODE (TREE_TYPE (ll_arg)));
2238 enum comparison_code lcompcode = comparison_to_compcode (lcode);
2239 enum comparison_code rcompcode = comparison_to_compcode (rcode);
2240 enum comparison_code compcode;
2244 case TRUTH_AND_EXPR: case TRUTH_ANDIF_EXPR:
2245 compcode = lcompcode & rcompcode;
2248 case TRUTH_OR_EXPR: case TRUTH_ORIF_EXPR:
2249 compcode = lcompcode | rcompcode;
2258 /* Eliminate unordered comparisons, as well as LTGT and ORD
2259 which are not used unless the mode has NaNs. */
2260 compcode &= ~COMPCODE_UNORD;
2261 if (compcode == COMPCODE_LTGT)
2262 compcode = COMPCODE_NE;
2263 else if (compcode == COMPCODE_ORD)
2264 compcode = COMPCODE_TRUE;
2266 else if (flag_trapping_math)
2268 /* Check that the original operation and the optimized ones will trap
2269 under the same condition. */
2270 bool ltrap = (lcompcode & COMPCODE_UNORD) == 0
2271 && (lcompcode != COMPCODE_EQ)
2272 && (lcompcode != COMPCODE_ORD);
2273 bool rtrap = (rcompcode & COMPCODE_UNORD) == 0
2274 && (rcompcode != COMPCODE_EQ)
2275 && (rcompcode != COMPCODE_ORD);
2276 bool trap = (compcode & COMPCODE_UNORD) == 0
2277 && (compcode != COMPCODE_EQ)
2278 && (compcode != COMPCODE_ORD);
2280 /* In a short-circuited boolean expression the LHS might be
2281 such that the RHS, if evaluated, will never trap. For
2282 example, in ORD (x, y) && (x < y), we evaluate the RHS only
2283 if neither x nor y is NaN. (This is a mixed blessing: for
2284 example, the expression above will never trap, hence
2285 optimizing it to x < y would be invalid). */
2286 if ((code == TRUTH_ORIF_EXPR && (lcompcode & COMPCODE_UNORD))
2287 || (code == TRUTH_ANDIF_EXPR && !(lcompcode & COMPCODE_UNORD)))
2290 /* If the comparison was short-circuited, and only the RHS
2291 trapped, we may now generate a spurious trap. */
2293 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2296 /* If we changed the conditions that cause a trap, we lose. */
2297 if ((ltrap || rtrap) != trap)
2301 if (compcode == COMPCODE_TRUE)
2302 return constant_boolean_node (true, truth_type);
2303 else if (compcode == COMPCODE_FALSE)
2304 return constant_boolean_node (false, truth_type);
2306 return fold (build2 (compcode_to_comparison (compcode),
2307 truth_type, ll_arg, lr_arg));
2310 /* Return nonzero if CODE is a tree code that represents a truth value. */
2313 truth_value_p (enum tree_code code)
2315 return (TREE_CODE_CLASS (code) == '<'
2316 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2317 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2318 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
2321 /* Return nonzero if two operands (typically of the same tree node)
2322 are necessarily equal. If either argument has side-effects this
2323 function returns zero. FLAGS modifies behavior as follows:
2325 If OEP_ONLY_CONST is set, only return nonzero for constants.
2326 This function tests whether the operands are indistinguishable;
2327 it does not test whether they are equal using C's == operation.
2328 The distinction is important for IEEE floating point, because
2329 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2330 (2) two NaNs may be indistinguishable, but NaN!=NaN.
2332 If OEP_ONLY_CONST is unset, a VAR_DECL is considered equal to itself
2333 even though it may hold multiple values during a function.
2334 This is because a GCC tree node guarantees that nothing else is
2335 executed between the evaluation of its "operands" (which may often
2336 be evaluated in arbitrary order). Hence if the operands themselves
2337 don't side-effect, the VAR_DECLs, PARM_DECLs etc... must hold the
2338 same value in each operand/subexpression. Hence leaving OEP_ONLY_CONST
2339 unset means assuming isochronic (or instantaneous) tree equivalence.
2340 Unless comparing arbitrary expression trees, such as from different
2341 statements, this flag can usually be left unset.
2343 If OEP_PURE_SAME is set, then pure functions with identical arguments
2344 are considered the same. It is used when the caller has other ways
2345 to ensure that global memory is unchanged in between. */
2348 operand_equal_p (tree arg0, tree arg1, unsigned int flags)
2350 /* If either is ERROR_MARK, they aren't equal. */
2351 if (TREE_CODE (arg0) == ERROR_MARK || TREE_CODE (arg1) == ERROR_MARK)
2354 /* If both types don't have the same signedness, then we can't consider
2355 them equal. We must check this before the STRIP_NOPS calls
2356 because they may change the signedness of the arguments. */
2357 if (TYPE_UNSIGNED (TREE_TYPE (arg0)) != TYPE_UNSIGNED (TREE_TYPE (arg1)))
2363 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2364 /* This is needed for conversions and for COMPONENT_REF.
2365 Might as well play it safe and always test this. */
2366 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
2367 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
2368 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
2371 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
2372 We don't care about side effects in that case because the SAVE_EXPR
2373 takes care of that for us. In all other cases, two expressions are
2374 equal if they have no side effects. If we have two identical
2375 expressions with side effects that should be treated the same due
2376 to the only side effects being identical SAVE_EXPR's, that will
2377 be detected in the recursive calls below. */
2378 if (arg0 == arg1 && ! (flags & OEP_ONLY_CONST)
2379 && (TREE_CODE (arg0) == SAVE_EXPR
2380 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
2383 /* Next handle constant cases, those for which we can return 1 even
2384 if ONLY_CONST is set. */
2385 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
2386 switch (TREE_CODE (arg0))
2389 return (! TREE_CONSTANT_OVERFLOW (arg0)
2390 && ! TREE_CONSTANT_OVERFLOW (arg1)
2391 && tree_int_cst_equal (arg0, arg1));
2394 return (! TREE_CONSTANT_OVERFLOW (arg0)
2395 && ! TREE_CONSTANT_OVERFLOW (arg1)
2396 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
2397 TREE_REAL_CST (arg1)));
2403 if (TREE_CONSTANT_OVERFLOW (arg0)
2404 || TREE_CONSTANT_OVERFLOW (arg1))
2407 v1 = TREE_VECTOR_CST_ELTS (arg0);
2408 v2 = TREE_VECTOR_CST_ELTS (arg1);
2411 if (!operand_equal_p (TREE_VALUE (v1), TREE_VALUE (v2),
2414 v1 = TREE_CHAIN (v1);
2415 v2 = TREE_CHAIN (v2);
2422 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
2424 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
2428 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
2429 && ! memcmp (TREE_STRING_POINTER (arg0),
2430 TREE_STRING_POINTER (arg1),
2431 TREE_STRING_LENGTH (arg0)));
2434 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
2440 if (flags & OEP_ONLY_CONST)
2443 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
2446 /* Two conversions are equal only if signedness and modes match. */
2447 if ((TREE_CODE (arg0) == NOP_EXPR || TREE_CODE (arg0) == CONVERT_EXPR)
2448 && (TYPE_UNSIGNED (TREE_TYPE (arg0))
2449 != TYPE_UNSIGNED (TREE_TYPE (arg1))))
2452 return operand_equal_p (TREE_OPERAND (arg0, 0),
2453 TREE_OPERAND (arg1, 0), flags);
2457 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0)
2458 && operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1),
2462 /* For commutative ops, allow the other order. */
2463 return (commutative_tree_code (TREE_CODE (arg0))
2464 && operand_equal_p (TREE_OPERAND (arg0, 0),
2465 TREE_OPERAND (arg1, 1), flags)
2466 && operand_equal_p (TREE_OPERAND (arg0, 1),
2467 TREE_OPERAND (arg1, 0), flags));
2470 /* If either of the pointer (or reference) expressions we are
2471 dereferencing contain a side effect, these cannot be equal. */
2472 if (TREE_SIDE_EFFECTS (arg0)
2473 || TREE_SIDE_EFFECTS (arg1))
2476 switch (TREE_CODE (arg0))
2479 return operand_equal_p (TREE_OPERAND (arg0, 0),
2480 TREE_OPERAND (arg1, 0), flags);
2484 case ARRAY_RANGE_REF:
2485 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2486 TREE_OPERAND (arg1, 0), flags)
2487 && operand_equal_p (TREE_OPERAND (arg0, 1),
2488 TREE_OPERAND (arg1, 1), flags));
2491 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2492 TREE_OPERAND (arg1, 0), flags)
2493 && operand_equal_p (TREE_OPERAND (arg0, 1),
2494 TREE_OPERAND (arg1, 1), flags)
2495 && operand_equal_p (TREE_OPERAND (arg0, 2),
2496 TREE_OPERAND (arg1, 2), flags));
2502 switch (TREE_CODE (arg0))
2505 case TRUTH_NOT_EXPR:
2506 return operand_equal_p (TREE_OPERAND (arg0, 0),
2507 TREE_OPERAND (arg1, 0), flags);
2510 return rtx_equal_p (RTL_EXPR_RTL (arg0), RTL_EXPR_RTL (arg1));
2513 /* If the CALL_EXPRs call different functions, then they
2514 clearly can not be equal. */
2515 if (! operand_equal_p (TREE_OPERAND (arg0, 0),
2516 TREE_OPERAND (arg1, 0), flags))
2520 unsigned int cef = call_expr_flags (arg0);
2521 if (flags & OEP_PURE_SAME)
2522 cef &= ECF_CONST | ECF_PURE;
2529 /* Now see if all the arguments are the same. operand_equal_p
2530 does not handle TREE_LIST, so we walk the operands here
2531 feeding them to operand_equal_p. */
2532 arg0 = TREE_OPERAND (arg0, 1);
2533 arg1 = TREE_OPERAND (arg1, 1);
2534 while (arg0 && arg1)
2536 if (! operand_equal_p (TREE_VALUE (arg0), TREE_VALUE (arg1),
2540 arg0 = TREE_CHAIN (arg0);
2541 arg1 = TREE_CHAIN (arg1);
2544 /* If we get here and both argument lists are exhausted
2545 then the CALL_EXPRs are equal. */
2546 return ! (arg0 || arg1);
2553 /* Consider __builtin_sqrt equal to sqrt. */
2554 return (TREE_CODE (arg0) == FUNCTION_DECL
2555 && DECL_BUILT_IN (arg0) && DECL_BUILT_IN (arg1)
2556 && DECL_BUILT_IN_CLASS (arg0) == DECL_BUILT_IN_CLASS (arg1)
2557 && DECL_FUNCTION_CODE (arg0) == DECL_FUNCTION_CODE (arg1));
2564 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2565 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2567 When in doubt, return 0. */
2570 operand_equal_for_comparison_p (tree arg0, tree arg1, tree other)
2572 int unsignedp1, unsignedpo;
2573 tree primarg0, primarg1, primother;
2574 unsigned int correct_width;
2576 if (operand_equal_p (arg0, arg1, 0))
2579 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
2580 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
2583 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2584 and see if the inner values are the same. This removes any
2585 signedness comparison, which doesn't matter here. */
2586 primarg0 = arg0, primarg1 = arg1;
2587 STRIP_NOPS (primarg0);
2588 STRIP_NOPS (primarg1);
2589 if (operand_equal_p (primarg0, primarg1, 0))
2592 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2593 actual comparison operand, ARG0.
2595 First throw away any conversions to wider types
2596 already present in the operands. */
2598 primarg1 = get_narrower (arg1, &unsignedp1);
2599 primother = get_narrower (other, &unsignedpo);
2601 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
2602 if (unsignedp1 == unsignedpo
2603 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
2604 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
2606 tree type = TREE_TYPE (arg0);
2608 /* Make sure shorter operand is extended the right way
2609 to match the longer operand. */
2610 primarg1 = fold_convert (lang_hooks.types.signed_or_unsigned_type
2611 (unsignedp1, TREE_TYPE (primarg1)), primarg1);
2613 if (operand_equal_p (arg0, fold_convert (type, primarg1), 0))
2620 /* See if ARG is an expression that is either a comparison or is performing
2621 arithmetic on comparisons. The comparisons must only be comparing
2622 two different values, which will be stored in *CVAL1 and *CVAL2; if
2623 they are nonzero it means that some operands have already been found.
2624 No variables may be used anywhere else in the expression except in the
2625 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2626 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2628 If this is true, return 1. Otherwise, return zero. */
2631 twoval_comparison_p (tree arg, tree *cval1, tree *cval2, int *save_p)
2633 enum tree_code code = TREE_CODE (arg);
2634 char class = TREE_CODE_CLASS (code);
2636 /* We can handle some of the 'e' cases here. */
2637 if (class == 'e' && code == TRUTH_NOT_EXPR)
2639 else if (class == 'e'
2640 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
2641 || code == COMPOUND_EXPR))
2644 else if (class == 'e' && code == SAVE_EXPR && SAVE_EXPR_RTL (arg) == 0
2645 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
2647 /* If we've already found a CVAL1 or CVAL2, this expression is
2648 two complex to handle. */
2649 if (*cval1 || *cval2)
2659 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
2662 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
2663 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2664 cval1, cval2, save_p));
2670 if (code == COND_EXPR)
2671 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
2672 cval1, cval2, save_p)
2673 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2674 cval1, cval2, save_p)
2675 && twoval_comparison_p (TREE_OPERAND (arg, 2),
2676 cval1, cval2, save_p));
2680 /* First see if we can handle the first operand, then the second. For
2681 the second operand, we know *CVAL1 can't be zero. It must be that
2682 one side of the comparison is each of the values; test for the
2683 case where this isn't true by failing if the two operands
2686 if (operand_equal_p (TREE_OPERAND (arg, 0),
2687 TREE_OPERAND (arg, 1), 0))
2691 *cval1 = TREE_OPERAND (arg, 0);
2692 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
2694 else if (*cval2 == 0)
2695 *cval2 = TREE_OPERAND (arg, 0);
2696 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
2701 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
2703 else if (*cval2 == 0)
2704 *cval2 = TREE_OPERAND (arg, 1);
2705 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
2717 /* ARG is a tree that is known to contain just arithmetic operations and
2718 comparisons. Evaluate the operations in the tree substituting NEW0 for
2719 any occurrence of OLD0 as an operand of a comparison and likewise for
2723 eval_subst (tree arg, tree old0, tree new0, tree old1, tree new1)
2725 tree type = TREE_TYPE (arg);
2726 enum tree_code code = TREE_CODE (arg);
2727 char class = TREE_CODE_CLASS (code);
2729 /* We can handle some of the 'e' cases here. */
2730 if (class == 'e' && code == TRUTH_NOT_EXPR)
2732 else if (class == 'e'
2733 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2739 return fold (build1 (code, type,
2740 eval_subst (TREE_OPERAND (arg, 0),
2741 old0, new0, old1, new1)));
2744 return fold (build2 (code, type,
2745 eval_subst (TREE_OPERAND (arg, 0),
2746 old0, new0, old1, new1),
2747 eval_subst (TREE_OPERAND (arg, 1),
2748 old0, new0, old1, new1)));
2754 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
2757 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
2760 return fold (build3 (code, type,
2761 eval_subst (TREE_OPERAND (arg, 0),
2762 old0, new0, old1, new1),
2763 eval_subst (TREE_OPERAND (arg, 1),
2764 old0, new0, old1, new1),
2765 eval_subst (TREE_OPERAND (arg, 2),
2766 old0, new0, old1, new1)));
2770 /* Fall through - ??? */
2774 tree arg0 = TREE_OPERAND (arg, 0);
2775 tree arg1 = TREE_OPERAND (arg, 1);
2777 /* We need to check both for exact equality and tree equality. The
2778 former will be true if the operand has a side-effect. In that
2779 case, we know the operand occurred exactly once. */
2781 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
2783 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
2786 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
2788 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
2791 return fold (build2 (code, type, arg0, arg1));
2799 /* Return a tree for the case when the result of an expression is RESULT
2800 converted to TYPE and OMITTED was previously an operand of the expression
2801 but is now not needed (e.g., we folded OMITTED * 0).
2803 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2804 the conversion of RESULT to TYPE. */
2807 omit_one_operand (tree type, tree result, tree omitted)
2809 tree t = fold_convert (type, result);
2811 if (TREE_SIDE_EFFECTS (omitted))
2812 return build2 (COMPOUND_EXPR, type, omitted, t);
2814 return non_lvalue (t);
2817 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2820 pedantic_omit_one_operand (tree type, tree result, tree omitted)
2822 tree t = fold_convert (type, result);
2824 if (TREE_SIDE_EFFECTS (omitted))
2825 return build2 (COMPOUND_EXPR, type, omitted, t);
2827 return pedantic_non_lvalue (t);
2830 /* Return a tree for the case when the result of an expression is RESULT
2831 converted to TYPE and OMITTED1 and OMITTED2 were previously operands
2832 of the expression but are now not needed.
2834 If OMITTED1 or OMITTED2 has side effects, they must be evaluated.
2835 If both OMITTED1 and OMITTED2 have side effects, OMITTED1 is
2836 evaluated before OMITTED2. Otherwise, if neither has side effects,
2837 just do the conversion of RESULT to TYPE. */
2840 omit_two_operands (tree type, tree result, tree omitted1, tree omitted2)
2842 tree t = fold_convert (type, result);
2844 if (TREE_SIDE_EFFECTS (omitted2))
2845 t = build2 (COMPOUND_EXPR, type, omitted2, t);
2846 if (TREE_SIDE_EFFECTS (omitted1))
2847 t = build2 (COMPOUND_EXPR, type, omitted1, t);
2849 return TREE_CODE (t) != COMPOUND_EXPR ? non_lvalue (t) : t;
2853 /* Return a simplified tree node for the truth-negation of ARG. This
2854 never alters ARG itself. We assume that ARG is an operation that
2855 returns a truth value (0 or 1).
2857 FIXME: one would think we would fold the result, but it causes
2858 problems with the dominator optimizer. */
2860 invert_truthvalue (tree arg)
2862 tree type = TREE_TYPE (arg);
2863 enum tree_code code = TREE_CODE (arg);
2865 if (code == ERROR_MARK)
2868 /* If this is a comparison, we can simply invert it, except for
2869 floating-point non-equality comparisons, in which case we just
2870 enclose a TRUTH_NOT_EXPR around what we have. */
2872 if (TREE_CODE_CLASS (code) == '<')
2874 tree op_type = TREE_TYPE (TREE_OPERAND (arg, 0));
2875 if (FLOAT_TYPE_P (op_type)
2876 && flag_trapping_math
2877 && code != ORDERED_EXPR && code != UNORDERED_EXPR
2878 && code != NE_EXPR && code != EQ_EXPR)
2879 return build1 (TRUTH_NOT_EXPR, type, arg);
2882 code = invert_tree_comparison (code,
2883 HONOR_NANS (TYPE_MODE (op_type)));
2884 if (code == ERROR_MARK)
2885 return build1 (TRUTH_NOT_EXPR, type, arg);
2887 return build2 (code, type,
2888 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
2895 return fold_convert (type, build_int_2 (integer_zerop (arg), 0));
2897 case TRUTH_AND_EXPR:
2898 return build2 (TRUTH_OR_EXPR, type,
2899 invert_truthvalue (TREE_OPERAND (arg, 0)),
2900 invert_truthvalue (TREE_OPERAND (arg, 1)));
2903 return build2 (TRUTH_AND_EXPR, type,
2904 invert_truthvalue (TREE_OPERAND (arg, 0)),
2905 invert_truthvalue (TREE_OPERAND (arg, 1)));
2907 case TRUTH_XOR_EXPR:
2908 /* Here we can invert either operand. We invert the first operand
2909 unless the second operand is a TRUTH_NOT_EXPR in which case our
2910 result is the XOR of the first operand with the inside of the
2911 negation of the second operand. */
2913 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
2914 return build2 (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
2915 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
2917 return build2 (TRUTH_XOR_EXPR, type,
2918 invert_truthvalue (TREE_OPERAND (arg, 0)),
2919 TREE_OPERAND (arg, 1));
2921 case TRUTH_ANDIF_EXPR:
2922 return build2 (TRUTH_ORIF_EXPR, type,
2923 invert_truthvalue (TREE_OPERAND (arg, 0)),
2924 invert_truthvalue (TREE_OPERAND (arg, 1)));
2926 case TRUTH_ORIF_EXPR:
2927 return build2 (TRUTH_ANDIF_EXPR, type,
2928 invert_truthvalue (TREE_OPERAND (arg, 0)),
2929 invert_truthvalue (TREE_OPERAND (arg, 1)));
2931 case TRUTH_NOT_EXPR:
2932 return TREE_OPERAND (arg, 0);
2935 return build3 (COND_EXPR, type, TREE_OPERAND (arg, 0),
2936 invert_truthvalue (TREE_OPERAND (arg, 1)),
2937 invert_truthvalue (TREE_OPERAND (arg, 2)));
2940 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
2941 invert_truthvalue (TREE_OPERAND (arg, 1)));
2943 case NON_LVALUE_EXPR:
2944 return invert_truthvalue (TREE_OPERAND (arg, 0));
2947 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE)
2952 return build1 (TREE_CODE (arg), type,
2953 invert_truthvalue (TREE_OPERAND (arg, 0)));
2956 if (!integer_onep (TREE_OPERAND (arg, 1)))
2958 return build2 (EQ_EXPR, type, arg,
2959 fold_convert (type, integer_zero_node));
2962 return build1 (TRUTH_NOT_EXPR, type, arg);
2964 case CLEANUP_POINT_EXPR:
2965 return build1 (CLEANUP_POINT_EXPR, type,
2966 invert_truthvalue (TREE_OPERAND (arg, 0)));
2971 if (TREE_CODE (TREE_TYPE (arg)) != BOOLEAN_TYPE)
2973 return build1 (TRUTH_NOT_EXPR, type, arg);
2976 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
2977 operands are another bit-wise operation with a common input. If so,
2978 distribute the bit operations to save an operation and possibly two if
2979 constants are involved. For example, convert
2980 (A | B) & (A | C) into A | (B & C)
2981 Further simplification will occur if B and C are constants.
2983 If this optimization cannot be done, 0 will be returned. */
2986 distribute_bit_expr (enum tree_code code, tree type, tree arg0, tree arg1)
2991 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2992 || TREE_CODE (arg0) == code
2993 || (TREE_CODE (arg0) != BIT_AND_EXPR
2994 && TREE_CODE (arg0) != BIT_IOR_EXPR))
2997 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
2999 common = TREE_OPERAND (arg0, 0);
3000 left = TREE_OPERAND (arg0, 1);
3001 right = TREE_OPERAND (arg1, 1);
3003 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
3005 common = TREE_OPERAND (arg0, 0);
3006 left = TREE_OPERAND (arg0, 1);
3007 right = TREE_OPERAND (arg1, 0);
3009 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
3011 common = TREE_OPERAND (arg0, 1);
3012 left = TREE_OPERAND (arg0, 0);
3013 right = TREE_OPERAND (arg1, 1);
3015 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
3017 common = TREE_OPERAND (arg0, 1);
3018 left = TREE_OPERAND (arg0, 0);
3019 right = TREE_OPERAND (arg1, 0);
3024 return fold (build2 (TREE_CODE (arg0), type, common,
3025 fold (build2 (code, type, left, right))));
3028 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
3029 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
3032 make_bit_field_ref (tree inner, tree type, int bitsize, int bitpos,
3035 tree result = build3 (BIT_FIELD_REF, type, inner,
3036 size_int (bitsize), bitsize_int (bitpos));
3038 BIT_FIELD_REF_UNSIGNED (result) = unsignedp;
3043 /* Optimize a bit-field compare.
3045 There are two cases: First is a compare against a constant and the
3046 second is a comparison of two items where the fields are at the same
3047 bit position relative to the start of a chunk (byte, halfword, word)
3048 large enough to contain it. In these cases we can avoid the shift
3049 implicit in bitfield extractions.
3051 For constants, we emit a compare of the shifted constant with the
3052 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
3053 compared. For two fields at the same position, we do the ANDs with the
3054 similar mask and compare the result of the ANDs.
3056 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
3057 COMPARE_TYPE is the type of the comparison, and LHS and RHS
3058 are the left and right operands of the comparison, respectively.
3060 If the optimization described above can be done, we return the resulting
3061 tree. Otherwise we return zero. */
3064 optimize_bit_field_compare (enum tree_code code, tree compare_type,
3067 HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
3068 tree type = TREE_TYPE (lhs);
3069 tree signed_type, unsigned_type;
3070 int const_p = TREE_CODE (rhs) == INTEGER_CST;
3071 enum machine_mode lmode, rmode, nmode;
3072 int lunsignedp, runsignedp;
3073 int lvolatilep = 0, rvolatilep = 0;
3074 tree linner, rinner = NULL_TREE;
3078 /* Get all the information about the extractions being done. If the bit size
3079 if the same as the size of the underlying object, we aren't doing an
3080 extraction at all and so can do nothing. We also don't want to
3081 do anything if the inner expression is a PLACEHOLDER_EXPR since we
3082 then will no longer be able to replace it. */
3083 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
3084 &lunsignedp, &lvolatilep);
3085 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
3086 || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
3091 /* If this is not a constant, we can only do something if bit positions,
3092 sizes, and signedness are the same. */
3093 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
3094 &runsignedp, &rvolatilep);
3096 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
3097 || lunsignedp != runsignedp || offset != 0
3098 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
3102 /* See if we can find a mode to refer to this field. We should be able to,
3103 but fail if we can't. */
3104 nmode = get_best_mode (lbitsize, lbitpos,
3105 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
3106 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
3107 TYPE_ALIGN (TREE_TYPE (rinner))),
3108 word_mode, lvolatilep || rvolatilep);
3109 if (nmode == VOIDmode)
3112 /* Set signed and unsigned types of the precision of this mode for the
3114 signed_type = lang_hooks.types.type_for_mode (nmode, 0);
3115 unsigned_type = lang_hooks.types.type_for_mode (nmode, 1);
3117 /* Compute the bit position and size for the new reference and our offset
3118 within it. If the new reference is the same size as the original, we
3119 won't optimize anything, so return zero. */
3120 nbitsize = GET_MODE_BITSIZE (nmode);
3121 nbitpos = lbitpos & ~ (nbitsize - 1);
3123 if (nbitsize == lbitsize)
3126 if (BYTES_BIG_ENDIAN)
3127 lbitpos = nbitsize - lbitsize - lbitpos;
3129 /* Make the mask to be used against the extracted field. */
3130 mask = build_int_2 (~0, ~0);
3131 TREE_TYPE (mask) = unsigned_type;
3132 force_fit_type (mask, 0);
3133 mask = fold_convert (unsigned_type, mask);
3134 mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
3135 mask = const_binop (RSHIFT_EXPR, mask,
3136 size_int (nbitsize - lbitsize - lbitpos), 0);
3139 /* If not comparing with constant, just rework the comparison
3141 return build2 (code, compare_type,
3142 build2 (BIT_AND_EXPR, unsigned_type,
3143 make_bit_field_ref (linner, unsigned_type,
3144 nbitsize, nbitpos, 1),
3146 build2 (BIT_AND_EXPR, unsigned_type,
3147 make_bit_field_ref (rinner, unsigned_type,
3148 nbitsize, nbitpos, 1),
3151 /* Otherwise, we are handling the constant case. See if the constant is too
3152 big for the field. Warn and return a tree of for 0 (false) if so. We do
3153 this not only for its own sake, but to avoid having to test for this
3154 error case below. If we didn't, we might generate wrong code.
3156 For unsigned fields, the constant shifted right by the field length should
3157 be all zero. For signed fields, the high-order bits should agree with
3162 if (! integer_zerop (const_binop (RSHIFT_EXPR,
3163 fold_convert (unsigned_type, rhs),
3164 size_int (lbitsize), 0)))
3166 warning ("comparison is always %d due to width of bit-field",
3168 return constant_boolean_node (code == NE_EXPR, compare_type);
3173 tree tem = const_binop (RSHIFT_EXPR, fold_convert (signed_type, rhs),
3174 size_int (lbitsize - 1), 0);
3175 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
3177 warning ("comparison is always %d due to width of bit-field",
3179 return constant_boolean_node (code == NE_EXPR, compare_type);
3183 /* Single-bit compares should always be against zero. */
3184 if (lbitsize == 1 && ! integer_zerop (rhs))
3186 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
3187 rhs = fold_convert (type, integer_zero_node);
3190 /* Make a new bitfield reference, shift the constant over the
3191 appropriate number of bits and mask it with the computed mask
3192 (in case this was a signed field). If we changed it, make a new one. */
3193 lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1);
3196 TREE_SIDE_EFFECTS (lhs) = 1;
3197 TREE_THIS_VOLATILE (lhs) = 1;
3200 rhs = fold (const_binop (BIT_AND_EXPR,
3201 const_binop (LSHIFT_EXPR,
3202 fold_convert (unsigned_type, rhs),
3203 size_int (lbitpos), 0),
3206 return build2 (code, compare_type,
3207 build2 (BIT_AND_EXPR, unsigned_type, lhs, mask),
3211 /* Subroutine for fold_truthop: decode a field reference.
3213 If EXP is a comparison reference, we return the innermost reference.
3215 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
3216 set to the starting bit number.
3218 If the innermost field can be completely contained in a mode-sized
3219 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
3221 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
3222 otherwise it is not changed.
3224 *PUNSIGNEDP is set to the signedness of the field.
3226 *PMASK is set to the mask used. This is either contained in a
3227 BIT_AND_EXPR or derived from the width of the field.
3229 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
3231 Return 0 if this is not a component reference or is one that we can't
3232 do anything with. */
3235 decode_field_reference (tree exp, HOST_WIDE_INT *pbitsize,
3236 HOST_WIDE_INT *pbitpos, enum machine_mode *pmode,
3237 int *punsignedp, int *pvolatilep,
3238 tree *pmask, tree *pand_mask)
3240 tree outer_type = 0;
3242 tree mask, inner, offset;
3244 unsigned int precision;
3246 /* All the optimizations using this function assume integer fields.
3247 There are problems with FP fields since the type_for_size call
3248 below can fail for, e.g., XFmode. */
3249 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
3252 /* We are interested in the bare arrangement of bits, so strip everything
3253 that doesn't affect the machine mode. However, record the type of the
3254 outermost expression if it may matter below. */
3255 if (TREE_CODE (exp) == NOP_EXPR
3256 || TREE_CODE (exp) == CONVERT_EXPR
3257 || TREE_CODE (exp) == NON_LVALUE_EXPR)
3258 outer_type = TREE_TYPE (exp);
3261 if (TREE_CODE (exp) == BIT_AND_EXPR)
3263 and_mask = TREE_OPERAND (exp, 1);
3264 exp = TREE_OPERAND (exp, 0);
3265 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
3266 if (TREE_CODE (and_mask) != INTEGER_CST)
3270 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
3271 punsignedp, pvolatilep);
3272 if ((inner == exp && and_mask == 0)
3273 || *pbitsize < 0 || offset != 0
3274 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
3277 /* If the number of bits in the reference is the same as the bitsize of
3278 the outer type, then the outer type gives the signedness. Otherwise
3279 (in case of a small bitfield) the signedness is unchanged. */
3280 if (outer_type && *pbitsize == tree_low_cst (TYPE_SIZE (outer_type), 1))
3281 *punsignedp = TYPE_UNSIGNED (outer_type);
3283 /* Compute the mask to access the bitfield. */
3284 unsigned_type = lang_hooks.types.type_for_size (*pbitsize, 1);
3285 precision = TYPE_PRECISION (unsigned_type);
3287 mask = build_int_2 (~0, ~0);
3288 TREE_TYPE (mask) = unsigned_type;
3289 force_fit_type (mask, 0);
3290 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3291 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3293 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
3295 mask = fold (build2 (BIT_AND_EXPR, unsigned_type,
3296 fold_convert (unsigned_type, and_mask), mask));
3299 *pand_mask = and_mask;
3303 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
3307 all_ones_mask_p (tree mask, int size)
3309 tree type = TREE_TYPE (mask);
3310 unsigned int precision = TYPE_PRECISION (type);
3313 tmask = build_int_2 (~0, ~0);
3314 TREE_TYPE (tmask) = lang_hooks.types.signed_type (type);
3315 force_fit_type (tmask, 0);
3317 tree_int_cst_equal (mask,
3318 const_binop (RSHIFT_EXPR,
3319 const_binop (LSHIFT_EXPR, tmask,
3320 size_int (precision - size),
3322 size_int (precision - size), 0));
3325 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
3326 represents the sign bit of EXP's type. If EXP represents a sign
3327 or zero extension, also test VAL against the unextended type.
3328 The return value is the (sub)expression whose sign bit is VAL,
3329 or NULL_TREE otherwise. */
3332 sign_bit_p (tree exp, tree val)
3334 unsigned HOST_WIDE_INT mask_lo, lo;
3335 HOST_WIDE_INT mask_hi, hi;
3339 /* Tree EXP must have an integral type. */
3340 t = TREE_TYPE (exp);
3341 if (! INTEGRAL_TYPE_P (t))
3344 /* Tree VAL must be an integer constant. */
3345 if (TREE_CODE (val) != INTEGER_CST
3346 || TREE_CONSTANT_OVERFLOW (val))
3349 width = TYPE_PRECISION (t);
3350 if (width > HOST_BITS_PER_WIDE_INT)
3352 hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1);
3355 mask_hi = ((unsigned HOST_WIDE_INT) -1
3356 >> (2 * HOST_BITS_PER_WIDE_INT - width));
3362 lo = (unsigned HOST_WIDE_INT) 1 << (width - 1);
3365 mask_lo = ((unsigned HOST_WIDE_INT) -1
3366 >> (HOST_BITS_PER_WIDE_INT - width));
3369 /* We mask off those bits beyond TREE_TYPE (exp) so that we can
3370 treat VAL as if it were unsigned. */
3371 if ((TREE_INT_CST_HIGH (val) & mask_hi) == hi
3372 && (TREE_INT_CST_LOW (val) & mask_lo) == lo)
3375 /* Handle extension from a narrower type. */
3376 if (TREE_CODE (exp) == NOP_EXPR
3377 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width)
3378 return sign_bit_p (TREE_OPERAND (exp, 0), val);
3383 /* Subroutine for fold_truthop: determine if an operand is simple enough
3384 to be evaluated unconditionally. */
3387 simple_operand_p (tree exp)
3389 /* Strip any conversions that don't change the machine mode. */
3390 while ((TREE_CODE (exp) == NOP_EXPR
3391 || TREE_CODE (exp) == CONVERT_EXPR)
3392 && (TYPE_MODE (TREE_TYPE (exp))
3393 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)))))
3394 exp = TREE_OPERAND (exp, 0);
3396 return (TREE_CODE_CLASS (TREE_CODE (exp)) == 'c'
3398 && ! TREE_ADDRESSABLE (exp)
3399 && ! TREE_THIS_VOLATILE (exp)
3400 && ! DECL_NONLOCAL (exp)
3401 /* Don't regard global variables as simple. They may be
3402 allocated in ways unknown to the compiler (shared memory,
3403 #pragma weak, etc). */
3404 && ! TREE_PUBLIC (exp)
3405 && ! DECL_EXTERNAL (exp)
3406 /* Loading a static variable is unduly expensive, but global
3407 registers aren't expensive. */
3408 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
3411 /* The following functions are subroutines to fold_range_test and allow it to
3412 try to change a logical combination of comparisons into a range test.
3415 X == 2 || X == 3 || X == 4 || X == 5
3419 (unsigned) (X - 2) <= 3
3421 We describe each set of comparisons as being either inside or outside
3422 a range, using a variable named like IN_P, and then describe the
3423 range with a lower and upper bound. If one of the bounds is omitted,
3424 it represents either the highest or lowest value of the type.
3426 In the comments below, we represent a range by two numbers in brackets
3427 preceded by a "+" to designate being inside that range, or a "-" to
3428 designate being outside that range, so the condition can be inverted by
3429 flipping the prefix. An omitted bound is represented by a "-". For
3430 example, "- [-, 10]" means being outside the range starting at the lowest
3431 possible value and ending at 10, in other words, being greater than 10.
3432 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
3435 We set up things so that the missing bounds are handled in a consistent
3436 manner so neither a missing bound nor "true" and "false" need to be
3437 handled using a special case. */
3439 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
3440 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
3441 and UPPER1_P are nonzero if the respective argument is an upper bound
3442 and zero for a lower. TYPE, if nonzero, is the type of the result; it
3443 must be specified for a comparison. ARG1 will be converted to ARG0's
3444 type if both are specified. */
3447 range_binop (enum tree_code code, tree type, tree arg0, int upper0_p,
3448 tree arg1, int upper1_p)
3454 /* If neither arg represents infinity, do the normal operation.
3455 Else, if not a comparison, return infinity. Else handle the special
3456 comparison rules. Note that most of the cases below won't occur, but
3457 are handled for consistency. */
3459 if (arg0 != 0 && arg1 != 0)
3461 tem = fold (build2 (code, type != 0 ? type : TREE_TYPE (arg0),
3462 arg0, fold_convert (TREE_TYPE (arg0), arg1)));
3464 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
3467 if (TREE_CODE_CLASS (code) != '<')
3470 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
3471 for neither. In real maths, we cannot assume open ended ranges are
3472 the same. But, this is computer arithmetic, where numbers are finite.
3473 We can therefore make the transformation of any unbounded range with
3474 the value Z, Z being greater than any representable number. This permits
3475 us to treat unbounded ranges as equal. */
3476 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
3477 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
3481 result = sgn0 == sgn1;
3484 result = sgn0 != sgn1;
3487 result = sgn0 < sgn1;
3490 result = sgn0 <= sgn1;
3493 result = sgn0 > sgn1;
3496 result = sgn0 >= sgn1;
3502 return constant_boolean_node (result, type);
3505 /* Given EXP, a logical expression, set the range it is testing into
3506 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
3507 actually being tested. *PLOW and *PHIGH will be made of the same type
3508 as the returned expression. If EXP is not a comparison, we will most
3509 likely not be returning a useful value and range. */
3512 make_range (tree exp, int *pin_p, tree *plow, tree *phigh)
3514 enum tree_code code;
3515 tree arg0 = NULL_TREE, arg1 = NULL_TREE, type = NULL_TREE;
3516 tree orig_type = NULL_TREE;
3518 tree low, high, n_low, n_high;
3520 /* Start with simply saying "EXP != 0" and then look at the code of EXP
3521 and see if we can refine the range. Some of the cases below may not
3522 happen, but it doesn't seem worth worrying about this. We "continue"
3523 the outer loop when we've changed something; otherwise we "break"
3524 the switch, which will "break" the while. */
3527 low = high = fold_convert (TREE_TYPE (exp), integer_zero_node);
3531 code = TREE_CODE (exp);
3533 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
3535 if (first_rtl_op (code) > 0)
3536 arg0 = TREE_OPERAND (exp, 0);
3537 if (TREE_CODE_CLASS (code) == '<'
3538 || TREE_CODE_CLASS (code) == '1'
3539 || TREE_CODE_CLASS (code) == '2')
3540 type = TREE_TYPE (arg0);
3541 if (TREE_CODE_CLASS (code) == '2'
3542 || TREE_CODE_CLASS (code) == '<'
3543 || (TREE_CODE_CLASS (code) == 'e'
3544 && TREE_CODE_LENGTH (code) > 1))
3545 arg1 = TREE_OPERAND (exp, 1);
3548 /* Set ORIG_TYPE as soon as TYPE is non-null so that we do not
3549 lose a cast by accident. */
3550 if (type != NULL_TREE && orig_type == NULL_TREE)
3555 case TRUTH_NOT_EXPR:
3556 in_p = ! in_p, exp = arg0;
3559 case EQ_EXPR: case NE_EXPR:
3560 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
3561 /* We can only do something if the range is testing for zero
3562 and if the second operand is an integer constant. Note that
3563 saying something is "in" the range we make is done by
3564 complementing IN_P since it will set in the initial case of
3565 being not equal to zero; "out" is leaving it alone. */
3566 if (low == 0 || high == 0
3567 || ! integer_zerop (low) || ! integer_zerop (high)
3568 || TREE_CODE (arg1) != INTEGER_CST)
3573 case NE_EXPR: /* - [c, c] */
3576 case EQ_EXPR: /* + [c, c] */
3577 in_p = ! in_p, low = high = arg1;
3579 case GT_EXPR: /* - [-, c] */
3580 low = 0, high = arg1;
3582 case GE_EXPR: /* + [c, -] */
3583 in_p = ! in_p, low = arg1, high = 0;
3585 case LT_EXPR: /* - [c, -] */
3586 low = arg1, high = 0;
3588 case LE_EXPR: /* + [-, c] */
3589 in_p = ! in_p, low = 0, high = arg1;
3597 /* If this is an unsigned comparison, we also know that EXP is
3598 greater than or equal to zero. We base the range tests we make
3599 on that fact, so we record it here so we can parse existing
3601 if (TYPE_UNSIGNED (type) && (low == 0 || high == 0))
3603 if (! merge_ranges (&n_in_p, &n_low, &n_high, in_p, low, high,
3604 1, fold_convert (type, integer_zero_node),
3608 in_p = n_in_p, low = n_low, high = n_high;
3610 /* If the high bound is missing, but we have a nonzero low
3611 bound, reverse the range so it goes from zero to the low bound
3613 if (high == 0 && low && ! integer_zerop (low))
3616 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
3617 integer_one_node, 0);
3618 low = fold_convert (type, integer_zero_node);
3624 /* (-x) IN [a,b] -> x in [-b, -a] */
3625 n_low = range_binop (MINUS_EXPR, type,
3626 fold_convert (type, integer_zero_node),
3628 n_high = range_binop (MINUS_EXPR, type,
3629 fold_convert (type, integer_zero_node),
3631 low = n_low, high = n_high;
3637 exp = build2 (MINUS_EXPR, type, negate_expr (arg0),
3638 fold_convert (type, integer_one_node));
3641 case PLUS_EXPR: case MINUS_EXPR:
3642 if (TREE_CODE (arg1) != INTEGER_CST)
3645 /* If EXP is signed, any overflow in the computation is undefined,
3646 so we don't worry about it so long as our computations on
3647 the bounds don't overflow. For unsigned, overflow is defined
3648 and this is exactly the right thing. */
3649 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3650 type, low, 0, arg1, 0);
3651 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3652 type, high, 1, arg1, 0);
3653 if ((n_low != 0 && TREE_OVERFLOW (n_low))
3654 || (n_high != 0 && TREE_OVERFLOW (n_high)))
3657 /* Check for an unsigned range which has wrapped around the maximum
3658 value thus making n_high < n_low, and normalize it. */
3659 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
3661 low = range_binop (PLUS_EXPR, type, n_high, 0,
3662 integer_one_node, 0);
3663 high = range_binop (MINUS_EXPR, type, n_low, 0,
3664 integer_one_node, 0);
3666 /* If the range is of the form +/- [ x+1, x ], we won't
3667 be able to normalize it. But then, it represents the
3668 whole range or the empty set, so make it
3670 if (tree_int_cst_equal (n_low, low)
3671 && tree_int_cst_equal (n_high, high))
3677 low = n_low, high = n_high;
3682 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
3683 if (TYPE_PRECISION (type) > TYPE_PRECISION (orig_type))
3686 if (! INTEGRAL_TYPE_P (type)
3687 || (low != 0 && ! int_fits_type_p (low, type))
3688 || (high != 0 && ! int_fits_type_p (high, type)))
3691 n_low = low, n_high = high;
3694 n_low = fold_convert (type, n_low);
3697 n_high = fold_convert (type, n_high);
3699 /* If we're converting from an unsigned to a signed type,
3700 we will be doing the comparison as unsigned. The tests above
3701 have already verified that LOW and HIGH are both positive.
3703 So we have to make sure that the original unsigned value will
3704 be interpreted as positive. */
3705 if (TYPE_UNSIGNED (type) && ! TYPE_UNSIGNED (TREE_TYPE (exp)))
3707 tree equiv_type = lang_hooks.types.type_for_mode
3708 (TYPE_MODE (type), 1);
3711 /* A range without an upper bound is, naturally, unbounded.
3712 Since convert would have cropped a very large value, use
3713 the max value for the destination type. */
3715 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
3716 : TYPE_MAX_VALUE (type);
3718 if (TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (exp)))
3719 high_positive = fold (build2 (RSHIFT_EXPR, type,
3723 integer_one_node)));
3725 /* If the low bound is specified, "and" the range with the
3726 range for which the original unsigned value will be
3730 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3731 1, n_low, n_high, 1,
3732 fold_convert (type, integer_zero_node),
3736 in_p = (n_in_p == in_p);
3740 /* Otherwise, "or" the range with the range of the input
3741 that will be interpreted as negative. */
3742 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3743 0, n_low, n_high, 1,
3744 fold_convert (type, integer_zero_node),
3748 in_p = (in_p != n_in_p);
3753 low = n_low, high = n_high;
3763 /* If EXP is a constant, we can evaluate whether this is true or false. */
3764 if (TREE_CODE (exp) == INTEGER_CST)
3766 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
3768 && integer_onep (range_binop (LE_EXPR, integer_type_node,
3774 *pin_p = in_p, *plow = low, *phigh = high;
3778 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3779 type, TYPE, return an expression to test if EXP is in (or out of, depending
3780 on IN_P) the range. Return 0 if the test couldn't be created. */
3783 build_range_check (tree type, tree exp, int in_p, tree low, tree high)
3785 tree etype = TREE_TYPE (exp);
3790 value = build_range_check (type, exp, 1, low, high);
3792 return invert_truthvalue (value);
3797 if (low == 0 && high == 0)
3798 return fold_convert (type, integer_one_node);
3801 return fold (build2 (LE_EXPR, type, exp, high));
3804 return fold (build2 (GE_EXPR, type, exp, low));
3806 if (operand_equal_p (low, high, 0))
3807 return fold (build2 (EQ_EXPR, type, exp, low));
3809 if (integer_zerop (low))
3811 if (! TYPE_UNSIGNED (etype))
3813 etype = lang_hooks.types.unsigned_type (etype);
3814 high = fold_convert (etype, high);
3815 exp = fold_convert (etype, exp);
3817 return build_range_check (type, exp, 1, 0, high);
3820 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
3821 if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST)
3823 unsigned HOST_WIDE_INT lo;
3827 prec = TYPE_PRECISION (etype);
3828 if (prec <= HOST_BITS_PER_WIDE_INT)
3831 lo = ((unsigned HOST_WIDE_INT) 1 << (prec - 1)) - 1;
3835 hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1;
3836 lo = (unsigned HOST_WIDE_INT) -1;
3839 if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo)
3841 if (TYPE_UNSIGNED (etype))
3843 etype = lang_hooks.types.signed_type (etype);
3844 exp = fold_convert (etype, exp);
3846 return fold (build2 (GT_EXPR, type, exp,
3847 fold_convert (etype, integer_zero_node)));
3851 value = const_binop (MINUS_EXPR, high, low, 0);
3852 if (value != 0 && TREE_OVERFLOW (value) && ! TYPE_UNSIGNED (etype))
3854 tree utype, minv, maxv;
3856 /* Check if (unsigned) INT_MAX + 1 == (unsigned) INT_MIN
3857 for the type in question, as we rely on this here. */
3858 switch (TREE_CODE (etype))
3863 utype = lang_hooks.types.unsigned_type (etype);
3864 maxv = fold_convert (utype, TYPE_MAX_VALUE (etype));
3865 maxv = range_binop (PLUS_EXPR, NULL_TREE, maxv, 1,
3866 integer_one_node, 1);
3867 minv = fold_convert (utype, TYPE_MIN_VALUE (etype));
3868 if (integer_zerop (range_binop (NE_EXPR, integer_type_node,
3872 high = fold_convert (etype, high);
3873 low = fold_convert (etype, low);
3874 exp = fold_convert (etype, exp);
3875 value = const_binop (MINUS_EXPR, high, low, 0);
3883 if (value != 0 && ! TREE_OVERFLOW (value))
3884 return build_range_check (type,
3885 fold (build2 (MINUS_EXPR, etype, exp, low)),
3886 1, fold_convert (etype, integer_zero_node),
3892 /* Given two ranges, see if we can merge them into one. Return 1 if we
3893 can, 0 if we can't. Set the output range into the specified parameters. */
3896 merge_ranges (int *pin_p, tree *plow, tree *phigh, int in0_p, tree low0,
3897 tree high0, int in1_p, tree low1, tree high1)
3905 int lowequal = ((low0 == 0 && low1 == 0)
3906 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3907 low0, 0, low1, 0)));
3908 int highequal = ((high0 == 0 && high1 == 0)
3909 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3910 high0, 1, high1, 1)));
3912 /* Make range 0 be the range that starts first, or ends last if they
3913 start at the same value. Swap them if it isn't. */
3914 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
3917 && integer_onep (range_binop (GT_EXPR, integer_type_node,
3918 high1, 1, high0, 1))))
3920 temp = in0_p, in0_p = in1_p, in1_p = temp;
3921 tem = low0, low0 = low1, low1 = tem;
3922 tem = high0, high0 = high1, high1 = tem;
3925 /* Now flag two cases, whether the ranges are disjoint or whether the
3926 second range is totally subsumed in the first. Note that the tests
3927 below are simplified by the ones above. */
3928 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
3929 high0, 1, low1, 0));
3930 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
3931 high1, 1, high0, 1));
3933 /* We now have four cases, depending on whether we are including or
3934 excluding the two ranges. */
3937 /* If they don't overlap, the result is false. If the second range
3938 is a subset it is the result. Otherwise, the range is from the start
3939 of the second to the end of the first. */
3941 in_p = 0, low = high = 0;
3943 in_p = 1, low = low1, high = high1;
3945 in_p = 1, low = low1, high = high0;
3948 else if (in0_p && ! in1_p)
3950 /* If they don't overlap, the result is the first range. If they are
3951 equal, the result is false. If the second range is a subset of the
3952 first, and the ranges begin at the same place, we go from just after
3953 the end of the first range to the end of the second. If the second
3954 range is not a subset of the first, or if it is a subset and both
3955 ranges end at the same place, the range starts at the start of the
3956 first range and ends just before the second range.
3957 Otherwise, we can't describe this as a single range. */
3959 in_p = 1, low = low0, high = high0;
3960 else if (lowequal && highequal)
3961 in_p = 0, low = high = 0;
3962 else if (subset && lowequal)
3964 in_p = 1, high = high0;
3965 low = range_binop (PLUS_EXPR, NULL_TREE, high1, 0,
3966 integer_one_node, 0);
3968 else if (! subset || highequal)
3970 in_p = 1, low = low0;
3971 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
3972 integer_one_node, 0);
3978 else if (! in0_p && in1_p)
3980 /* If they don't overlap, the result is the second range. If the second
3981 is a subset of the first, the result is false. Otherwise,
3982 the range starts just after the first range and ends at the
3983 end of the second. */
3985 in_p = 1, low = low1, high = high1;
3986 else if (subset || highequal)
3987 in_p = 0, low = high = 0;
3990 in_p = 1, high = high1;
3991 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
3992 integer_one_node, 0);
3998 /* The case where we are excluding both ranges. Here the complex case
3999 is if they don't overlap. In that case, the only time we have a
4000 range is if they are adjacent. If the second is a subset of the
4001 first, the result is the first. Otherwise, the range to exclude
4002 starts at the beginning of the first range and ends at the end of the
4006 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
4007 range_binop (PLUS_EXPR, NULL_TREE,
4009 integer_one_node, 1),
4011 in_p = 0, low = low0, high = high1;
4014 /* Canonicalize - [min, x] into - [-, x]. */
4015 if (low0 && TREE_CODE (low0) == INTEGER_CST)
4016 switch (TREE_CODE (TREE_TYPE (low0)))
4019 if (TYPE_PRECISION (TREE_TYPE (low0))
4020 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (low0))))
4025 if (tree_int_cst_equal (low0,
4026 TYPE_MIN_VALUE (TREE_TYPE (low0))))
4030 if (TYPE_UNSIGNED (TREE_TYPE (low0))
4031 && integer_zerop (low0))
4038 /* Canonicalize - [x, max] into - [x, -]. */
4039 if (high1 && TREE_CODE (high1) == INTEGER_CST)
4040 switch (TREE_CODE (TREE_TYPE (high1)))
4043 if (TYPE_PRECISION (TREE_TYPE (high1))
4044 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (high1))))
4049 if (tree_int_cst_equal (high1,
4050 TYPE_MAX_VALUE (TREE_TYPE (high1))))
4054 if (TYPE_UNSIGNED (TREE_TYPE (high1))
4055 && integer_zerop (range_binop (PLUS_EXPR, NULL_TREE,
4057 integer_one_node, 1)))
4064 /* The ranges might be also adjacent between the maximum and
4065 minimum values of the given type. For
4066 - [{min,-}, x] and - [y, {max,-}] ranges where x + 1 < y
4067 return + [x + 1, y - 1]. */
4068 if (low0 == 0 && high1 == 0)
4070 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
4071 integer_one_node, 1);
4072 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
4073 integer_one_node, 0);
4074 if (low == 0 || high == 0)
4084 in_p = 0, low = low0, high = high0;
4086 in_p = 0, low = low0, high = high1;
4089 *pin_p = in_p, *plow = low, *phigh = high;
4094 /* Subroutine of fold, looking inside expressions of the form
4095 A op B ? A : C, where ARG0 is A op B and ARG2 is C. This
4096 function is being used also to optimize A op B ? C : A, by
4097 reversing the comparison first.
4099 Return a folded expression whose code is not a COND_EXPR
4100 anymore, or NULL_TREE if no folding opportunity is found. */
4103 fold_cond_expr_with_comparison (tree type, tree arg0, tree arg2)
4105 enum tree_code comp_code = TREE_CODE (arg0);
4106 tree arg00 = TREE_OPERAND (arg0, 0);
4107 tree arg01 = TREE_OPERAND (arg0, 1);
4111 /* If we have A op 0 ? A : -A, consider applying the following
4114 A == 0? A : -A same as -A
4115 A != 0? A : -A same as A
4116 A >= 0? A : -A same as abs (A)
4117 A > 0? A : -A same as abs (A)
4118 A <= 0? A : -A same as -abs (A)
4119 A < 0? A : -A same as -abs (A)
4121 None of these transformations work for modes with signed
4122 zeros. If A is +/-0, the first two transformations will
4123 change the sign of the result (from +0 to -0, or vice
4124 versa). The last four will fix the sign of the result,
4125 even though the original expressions could be positive or
4126 negative, depending on the sign of A.
4128 Note that all these transformations are correct if A is
4129 NaN, since the two alternatives (A and -A) are also NaNs. */
4130 if ((FLOAT_TYPE_P (TREE_TYPE (arg01))
4131 ? real_zerop (arg01)
4132 : integer_zerop (arg01))
4133 && TREE_CODE (arg2) == NEGATE_EXPR
4134 && operand_equal_p (TREE_OPERAND (arg2, 0), arg00, 0))
4138 return fold_convert (type, negate_expr (arg00));
4140 return pedantic_non_lvalue (fold_convert (type, arg00));
4143 if (TYPE_UNSIGNED (TREE_TYPE (arg00)))
4144 arg00 = fold_convert (lang_hooks.types.signed_type
4145 (TREE_TYPE (arg00)), arg00);
4146 tem = fold (build1 (ABS_EXPR, TREE_TYPE (arg00), arg00));
4147 return pedantic_non_lvalue (fold_convert (type, tem));
4150 if (TYPE_UNSIGNED (TREE_TYPE (arg00)))
4151 arg00 = fold_convert (lang_hooks.types.signed_type
4152 (TREE_TYPE (arg00)), arg00);
4153 tem = fold (build1 (ABS_EXPR, TREE_TYPE (arg00), arg00));
4154 return negate_expr (fold_convert (type, tem));
4159 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
4160 A == 0 ? A : 0 is always 0 unless A is -0. Note that
4161 both transformations are correct when A is NaN: A != 0
4162 is then true, and A == 0 is false. */
4164 if (integer_zerop (arg01) && integer_zerop (arg2))
4166 if (comp_code == NE_EXPR)
4167 return pedantic_non_lvalue (fold_convert (type, arg00));
4168 else if (comp_code == EQ_EXPR)
4169 return pedantic_non_lvalue (fold_convert (type, integer_zero_node));
4172 /* Try some transformations of A op B ? A : B.
4174 A == B? A : B same as B
4175 A != B? A : B same as A
4176 A >= B? A : B same as max (A, B)
4177 A > B? A : B same as max (B, A)
4178 A <= B? A : B same as min (A, B)
4179 A < B? A : B same as min (B, A)
4181 As above, these transformations don't work in the presence
4182 of signed zeros. For example, if A and B are zeros of
4183 opposite sign, the first two transformations will change
4184 the sign of the result. In the last four, the original
4185 expressions give different results for (A=+0, B=-0) and
4186 (A=-0, B=+0), but the transformed expressions do not.
4188 The first two transformations are correct if either A or B
4189 is a NaN. In the first transformation, the condition will
4190 be false, and B will indeed be chosen. In the case of the
4191 second transformation, the condition A != B will be true,
4192 and A will be chosen.
4194 The conversions to max() and min() are not correct if B is
4195 a number and A is not. The conditions in the original
4196 expressions will be false, so all four give B. The min()
4197 and max() versions would give a NaN instead. */
4198 if (operand_equal_for_comparison_p (arg01, arg2, arg00))
4200 tree comp_op0 = arg00;
4201 tree comp_op1 = arg01;
4202 tree comp_type = TREE_TYPE (comp_op0);
4204 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
4205 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
4215 return pedantic_non_lvalue (fold_convert (type, arg2));
4217 return pedantic_non_lvalue (fold_convert (type, arg00));
4220 /* In C++ a ?: expression can be an lvalue, so put the
4221 operand which will be used if they are equal first
4222 so that we can convert this back to the
4223 corresponding COND_EXPR. */
4224 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg00))))
4225 return pedantic_non_lvalue (
4226 fold_convert (type, fold (build2 (MIN_EXPR, comp_type,
4227 (comp_code == LE_EXPR
4228 ? comp_op0 : comp_op1),
4229 (comp_code == LE_EXPR
4230 ? comp_op1 : comp_op0)))));
4234 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg00))))
4235 return pedantic_non_lvalue (
4236 fold_convert (type, fold (build2 (MAX_EXPR, comp_type,
4237 (comp_code == GE_EXPR
4238 ? comp_op0 : comp_op1),
4239 (comp_code == GE_EXPR
4240 ? comp_op1 : comp_op0)))));
4247 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
4248 we might still be able to simplify this. For example,
4249 if C1 is one less or one more than C2, this might have started
4250 out as a MIN or MAX and been transformed by this function.
4251 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
4253 if (INTEGRAL_TYPE_P (type)
4254 && TREE_CODE (arg01) == INTEGER_CST
4255 && TREE_CODE (arg2) == INTEGER_CST)
4259 /* We can replace A with C1 in this case. */
4260 arg00 = fold_convert (type, arg01);
4261 return fold (build3 (COND_EXPR, type, arg0, arg00, arg2));
4264 /* If C1 is C2 + 1, this is min(A, C2). */
4265 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
4267 && operand_equal_p (arg01,
4268 const_binop (PLUS_EXPR, arg2,
4269 integer_one_node, 0),
4271 return pedantic_non_lvalue (fold (build2 (MIN_EXPR,
4272 type, arg00, arg2)));
4276 /* If C1 is C2 - 1, this is min(A, C2). */
4277 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
4279 && operand_equal_p (arg01,
4280 const_binop (MINUS_EXPR, arg2,
4281 integer_one_node, 0),
4283 return pedantic_non_lvalue (fold (build2 (MIN_EXPR,
4284 type, arg00, arg2)));
4288 /* If C1 is C2 - 1, this is max(A, C2). */
4289 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
4291 && operand_equal_p (arg01,
4292 const_binop (MINUS_EXPR, arg2,
4293 integer_one_node, 0),
4295 return pedantic_non_lvalue (fold (build2 (MAX_EXPR,
4296 type, arg00, arg2)));
4300 /* If C1 is C2 + 1, this is max(A, C2). */
4301 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
4303 && operand_equal_p (arg01,
4304 const_binop (PLUS_EXPR, arg2,
4305 integer_one_node, 0),
4307 return pedantic_non_lvalue (fold (build2 (MAX_EXPR,
4308 type, arg00, arg2)));
4321 #ifndef RANGE_TEST_NON_SHORT_CIRCUIT
4322 #define RANGE_TEST_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
4325 /* EXP is some logical combination of boolean tests. See if we can
4326 merge it into some range test. Return the new tree if so. */
4329 fold_range_test (tree exp)
4331 int or_op = (TREE_CODE (exp) == TRUTH_ORIF_EXPR
4332 || TREE_CODE (exp) == TRUTH_OR_EXPR);
4333 int in0_p, in1_p, in_p;
4334 tree low0, low1, low, high0, high1, high;
4335 tree lhs = make_range (TREE_OPERAND (exp, 0), &in0_p, &low0, &high0);
4336 tree rhs = make_range (TREE_OPERAND (exp, 1), &in1_p, &low1, &high1);
4339 /* If this is an OR operation, invert both sides; we will invert
4340 again at the end. */
4342 in0_p = ! in0_p, in1_p = ! in1_p;
4344 /* If both expressions are the same, if we can merge the ranges, and we
4345 can build the range test, return it or it inverted. If one of the
4346 ranges is always true or always false, consider it to be the same
4347 expression as the other. */
4348 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
4349 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
4351 && 0 != (tem = (build_range_check (TREE_TYPE (exp),
4353 : rhs != 0 ? rhs : integer_zero_node,
4355 return or_op ? invert_truthvalue (tem) : tem;
4357 /* On machines where the branch cost is expensive, if this is a
4358 short-circuited branch and the underlying object on both sides
4359 is the same, make a non-short-circuit operation. */
4360 else if (RANGE_TEST_NON_SHORT_CIRCUIT
4361 && lhs != 0 && rhs != 0
4362 && (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
4363 || TREE_CODE (exp) == TRUTH_ORIF_EXPR)
4364 && operand_equal_p (lhs, rhs, 0))
4366 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
4367 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
4368 which cases we can't do this. */
4369 if (simple_operand_p (lhs))
4370 return build2 (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
4371 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
4372 TREE_TYPE (exp), TREE_OPERAND (exp, 0),
4373 TREE_OPERAND (exp, 1));
4375 else if (lang_hooks.decls.global_bindings_p () == 0
4376 && ! CONTAINS_PLACEHOLDER_P (lhs))
4378 tree common = save_expr (lhs);
4380 if (0 != (lhs = build_range_check (TREE_TYPE (exp), common,
4381 or_op ? ! in0_p : in0_p,
4383 && (0 != (rhs = build_range_check (TREE_TYPE (exp), common,
4384 or_op ? ! in1_p : in1_p,
4386 return build2 (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
4387 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
4388 TREE_TYPE (exp), lhs, rhs);
4395 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
4396 bit value. Arrange things so the extra bits will be set to zero if and
4397 only if C is signed-extended to its full width. If MASK is nonzero,
4398 it is an INTEGER_CST that should be AND'ed with the extra bits. */
4401 unextend (tree c, int p, int unsignedp, tree mask)
4403 tree type = TREE_TYPE (c);
4404 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
4407 if (p == modesize || unsignedp)
4410 /* We work by getting just the sign bit into the low-order bit, then
4411 into the high-order bit, then sign-extend. We then XOR that value
4413 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
4414 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
4416 /* We must use a signed type in order to get an arithmetic right shift.
4417 However, we must also avoid introducing accidental overflows, so that
4418 a subsequent call to integer_zerop will work. Hence we must
4419 do the type conversion here. At this point, the constant is either
4420 zero or one, and the conversion to a signed type can never overflow.
4421 We could get an overflow if this conversion is done anywhere else. */
4422 if (TYPE_UNSIGNED (type))
4423 temp = fold_convert (lang_hooks.types.signed_type (type), temp);
4425 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
4426 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
4428 temp = const_binop (BIT_AND_EXPR, temp,
4429 fold_convert (TREE_TYPE (c), mask), 0);
4430 /* If necessary, convert the type back to match the type of C. */
4431 if (TYPE_UNSIGNED (type))
4432 temp = fold_convert (type, temp);
4434 return fold_convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
4437 /* Find ways of folding logical expressions of LHS and RHS:
4438 Try to merge two comparisons to the same innermost item.
4439 Look for range tests like "ch >= '0' && ch <= '9'".
4440 Look for combinations of simple terms on machines with expensive branches
4441 and evaluate the RHS unconditionally.
4443 For example, if we have p->a == 2 && p->b == 4 and we can make an
4444 object large enough to span both A and B, we can do this with a comparison
4445 against the object ANDed with the a mask.
4447 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
4448 operations to do this with one comparison.
4450 We check for both normal comparisons and the BIT_AND_EXPRs made this by
4451 function and the one above.
4453 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
4454 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
4456 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
4459 We return the simplified tree or 0 if no optimization is possible. */
4462 fold_truthop (enum tree_code code, tree truth_type, tree lhs, tree rhs)
4464 /* If this is the "or" of two comparisons, we can do something if
4465 the comparisons are NE_EXPR. If this is the "and", we can do something
4466 if the comparisons are EQ_EXPR. I.e.,
4467 (a->b == 2 && a->c == 4) can become (a->new == NEW).
4469 WANTED_CODE is this operation code. For single bit fields, we can
4470 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
4471 comparison for one-bit fields. */
4473 enum tree_code wanted_code;
4474 enum tree_code lcode, rcode;
4475 tree ll_arg, lr_arg, rl_arg, rr_arg;
4476 tree ll_inner, lr_inner, rl_inner, rr_inner;
4477 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
4478 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
4479 HOST_WIDE_INT xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
4480 HOST_WIDE_INT lnbitsize, lnbitpos, rnbitsize, rnbitpos;
4481 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
4482 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
4483 enum machine_mode lnmode, rnmode;
4484 tree ll_mask, lr_mask, rl_mask, rr_mask;
4485 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
4486 tree l_const, r_const;
4487 tree lntype, rntype, result;
4488 int first_bit, end_bit;
4491 /* Start by getting the comparison codes. Fail if anything is volatile.
4492 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
4493 it were surrounded with a NE_EXPR. */
4495 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
4498 lcode = TREE_CODE (lhs);
4499 rcode = TREE_CODE (rhs);
4501 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
4503 lhs = build2 (NE_EXPR, truth_type, lhs, integer_zero_node);
4507 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
4509 rhs = build2 (NE_EXPR, truth_type, rhs, integer_zero_node);
4513 if (TREE_CODE_CLASS (lcode) != '<' || TREE_CODE_CLASS (rcode) != '<')
4516 ll_arg = TREE_OPERAND (lhs, 0);
4517 lr_arg = TREE_OPERAND (lhs, 1);
4518 rl_arg = TREE_OPERAND (rhs, 0);
4519 rr_arg = TREE_OPERAND (rhs, 1);
4521 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
4522 if (simple_operand_p (ll_arg)
4523 && simple_operand_p (lr_arg))
4526 if (operand_equal_p (ll_arg, rl_arg, 0)
4527 && operand_equal_p (lr_arg, rr_arg, 0))
4529 result = combine_comparisons (code, lcode, rcode,
4530 truth_type, ll_arg, lr_arg);
4534 else if (operand_equal_p (ll_arg, rr_arg, 0)
4535 && operand_equal_p (lr_arg, rl_arg, 0))
4537 result = combine_comparisons (code, lcode,
4538 swap_tree_comparison (rcode),
4539 truth_type, ll_arg, lr_arg);
4545 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
4546 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
4548 /* If the RHS can be evaluated unconditionally and its operands are
4549 simple, it wins to evaluate the RHS unconditionally on machines
4550 with expensive branches. In this case, this isn't a comparison
4551 that can be merged. Avoid doing this if the RHS is a floating-point
4552 comparison since those can trap. */
4554 if (BRANCH_COST >= 2
4555 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
4556 && simple_operand_p (rl_arg)
4557 && simple_operand_p (rr_arg))
4559 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
4560 if (code == TRUTH_OR_EXPR
4561 && lcode == NE_EXPR && integer_zerop (lr_arg)
4562 && rcode == NE_EXPR && integer_zerop (rr_arg)
4563 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
4564 return build2 (NE_EXPR, truth_type,
4565 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
4567 fold_convert (TREE_TYPE (ll_arg), integer_zero_node));
4569 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
4570 if (code == TRUTH_AND_EXPR
4571 && lcode == EQ_EXPR && integer_zerop (lr_arg)
4572 && rcode == EQ_EXPR && integer_zerop (rr_arg)
4573 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
4574 return build2 (EQ_EXPR, truth_type,
4575 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
4577 fold_convert (TREE_TYPE (ll_arg), integer_zero_node));
4579 return build2 (code, truth_type, lhs, rhs);
4582 /* See if the comparisons can be merged. Then get all the parameters for
4585 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
4586 || (rcode != EQ_EXPR && rcode != NE_EXPR))
4590 ll_inner = decode_field_reference (ll_arg,
4591 &ll_bitsize, &ll_bitpos, &ll_mode,
4592 &ll_unsignedp, &volatilep, &ll_mask,
4594 lr_inner = decode_field_reference (lr_arg,
4595 &lr_bitsize, &lr_bitpos, &lr_mode,
4596 &lr_unsignedp, &volatilep, &lr_mask,
4598 rl_inner = decode_field_reference (rl_arg,
4599 &rl_bitsize, &rl_bitpos, &rl_mode,
4600 &rl_unsignedp, &volatilep, &rl_mask,
4602 rr_inner = decode_field_reference (rr_arg,
4603 &rr_bitsize, &rr_bitpos, &rr_mode,
4604 &rr_unsignedp, &volatilep, &rr_mask,
4607 /* It must be true that the inner operation on the lhs of each
4608 comparison must be the same if we are to be able to do anything.
4609 Then see if we have constants. If not, the same must be true for
4611 if (volatilep || ll_inner == 0 || rl_inner == 0
4612 || ! operand_equal_p (ll_inner, rl_inner, 0))
4615 if (TREE_CODE (lr_arg) == INTEGER_CST
4616 && TREE_CODE (rr_arg) == INTEGER_CST)
4617 l_const = lr_arg, r_const = rr_arg;
4618 else if (lr_inner == 0 || rr_inner == 0
4619 || ! operand_equal_p (lr_inner, rr_inner, 0))
4622 l_const = r_const = 0;
4624 /* If either comparison code is not correct for our logical operation,
4625 fail. However, we can convert a one-bit comparison against zero into
4626 the opposite comparison against that bit being set in the field. */
4628 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
4629 if (lcode != wanted_code)
4631 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
4633 /* Make the left operand unsigned, since we are only interested
4634 in the value of one bit. Otherwise we are doing the wrong
4643 /* This is analogous to the code for l_const above. */
4644 if (rcode != wanted_code)
4646 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
4655 /* After this point all optimizations will generate bit-field
4656 references, which we might not want. */
4657 if (! lang_hooks.can_use_bit_fields_p ())
4660 /* See if we can find a mode that contains both fields being compared on
4661 the left. If we can't, fail. Otherwise, update all constants and masks
4662 to be relative to a field of that size. */
4663 first_bit = MIN (ll_bitpos, rl_bitpos);
4664 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
4665 lnmode = get_best_mode (end_bit - first_bit, first_bit,
4666 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
4668 if (lnmode == VOIDmode)
4671 lnbitsize = GET_MODE_BITSIZE (lnmode);
4672 lnbitpos = first_bit & ~ (lnbitsize - 1);
4673 lntype = lang_hooks.types.type_for_size (lnbitsize, 1);
4674 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
4676 if (BYTES_BIG_ENDIAN)
4678 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
4679 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
4682 ll_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, ll_mask),
4683 size_int (xll_bitpos), 0);
4684 rl_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, rl_mask),
4685 size_int (xrl_bitpos), 0);
4689 l_const = fold_convert (lntype, l_const);
4690 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
4691 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
4692 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
4693 fold (build1 (BIT_NOT_EXPR,
4697 warning ("comparison is always %d", wanted_code == NE_EXPR);
4699 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
4704 r_const = fold_convert (lntype, r_const);
4705 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
4706 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
4707 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
4708 fold (build1 (BIT_NOT_EXPR,
4712 warning ("comparison is always %d", wanted_code == NE_EXPR);
4714 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
4718 /* If the right sides are not constant, do the same for it. Also,
4719 disallow this optimization if a size or signedness mismatch occurs
4720 between the left and right sides. */
4723 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
4724 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
4725 /* Make sure the two fields on the right
4726 correspond to the left without being swapped. */
4727 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
4730 first_bit = MIN (lr_bitpos, rr_bitpos);
4731 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
4732 rnmode = get_best_mode (end_bit - first_bit, first_bit,
4733 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
4735 if (rnmode == VOIDmode)
4738 rnbitsize = GET_MODE_BITSIZE (rnmode);
4739 rnbitpos = first_bit & ~ (rnbitsize - 1);
4740 rntype = lang_hooks.types.type_for_size (rnbitsize, 1);
4741 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
4743 if (BYTES_BIG_ENDIAN)
4745 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
4746 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
4749 lr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, lr_mask),
4750 size_int (xlr_bitpos), 0);
4751 rr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, rr_mask),
4752 size_int (xrr_bitpos), 0);
4754 /* Make a mask that corresponds to both fields being compared.
4755 Do this for both items being compared. If the operands are the
4756 same size and the bits being compared are in the same position
4757 then we can do this by masking both and comparing the masked
4759 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4760 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
4761 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
4763 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4764 ll_unsignedp || rl_unsignedp);
4765 if (! all_ones_mask_p (ll_mask, lnbitsize))
4766 lhs = build2 (BIT_AND_EXPR, lntype, lhs, ll_mask);
4768 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
4769 lr_unsignedp || rr_unsignedp);
4770 if (! all_ones_mask_p (lr_mask, rnbitsize))
4771 rhs = build2 (BIT_AND_EXPR, rntype, rhs, lr_mask);
4773 return build2 (wanted_code, truth_type, lhs, rhs);
4776 /* There is still another way we can do something: If both pairs of
4777 fields being compared are adjacent, we may be able to make a wider
4778 field containing them both.
4780 Note that we still must mask the lhs/rhs expressions. Furthermore,
4781 the mask must be shifted to account for the shift done by
4782 make_bit_field_ref. */
4783 if ((ll_bitsize + ll_bitpos == rl_bitpos
4784 && lr_bitsize + lr_bitpos == rr_bitpos)
4785 || (ll_bitpos == rl_bitpos + rl_bitsize
4786 && lr_bitpos == rr_bitpos + rr_bitsize))
4790 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
4791 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
4792 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
4793 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
4795 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
4796 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
4797 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
4798 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
4800 /* Convert to the smaller type before masking out unwanted bits. */
4802 if (lntype != rntype)
4804 if (lnbitsize > rnbitsize)
4806 lhs = fold_convert (rntype, lhs);
4807 ll_mask = fold_convert (rntype, ll_mask);
4810 else if (lnbitsize < rnbitsize)
4812 rhs = fold_convert (lntype, rhs);
4813 lr_mask = fold_convert (lntype, lr_mask);
4818 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
4819 lhs = build2 (BIT_AND_EXPR, type, lhs, ll_mask);
4821 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
4822 rhs = build2 (BIT_AND_EXPR, type, rhs, lr_mask);
4824 return build2 (wanted_code, truth_type, lhs, rhs);
4830 /* Handle the case of comparisons with constants. If there is something in
4831 common between the masks, those bits of the constants must be the same.
4832 If not, the condition is always false. Test for this to avoid generating
4833 incorrect code below. */
4834 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
4835 if (! integer_zerop (result)
4836 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
4837 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
4839 if (wanted_code == NE_EXPR)
4841 warning ("`or' of unmatched not-equal tests is always 1");
4842 return constant_boolean_node (true, truth_type);
4846 warning ("`and' of mutually exclusive equal-tests is always 0");
4847 return constant_boolean_node (false, truth_type);
4851 /* Construct the expression we will return. First get the component
4852 reference we will make. Unless the mask is all ones the width of
4853 that field, perform the mask operation. Then compare with the
4855 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4856 ll_unsignedp || rl_unsignedp);
4858 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4859 if (! all_ones_mask_p (ll_mask, lnbitsize))
4860 result = build2 (BIT_AND_EXPR, lntype, result, ll_mask);
4862 return build2 (wanted_code, truth_type, result,
4863 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
4866 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
4870 optimize_minmax_comparison (tree t)
4872 tree type = TREE_TYPE (t);
4873 tree arg0 = TREE_OPERAND (t, 0);
4874 enum tree_code op_code;
4875 tree comp_const = TREE_OPERAND (t, 1);
4877 int consts_equal, consts_lt;
4880 STRIP_SIGN_NOPS (arg0);
4882 op_code = TREE_CODE (arg0);
4883 minmax_const = TREE_OPERAND (arg0, 1);
4884 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
4885 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
4886 inner = TREE_OPERAND (arg0, 0);
4888 /* If something does not permit us to optimize, return the original tree. */
4889 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
4890 || TREE_CODE (comp_const) != INTEGER_CST
4891 || TREE_CONSTANT_OVERFLOW (comp_const)
4892 || TREE_CODE (minmax_const) != INTEGER_CST
4893 || TREE_CONSTANT_OVERFLOW (minmax_const))
4896 /* Now handle all the various comparison codes. We only handle EQ_EXPR
4897 and GT_EXPR, doing the rest with recursive calls using logical
4899 switch (TREE_CODE (t))
4901 case NE_EXPR: case LT_EXPR: case LE_EXPR:
4903 invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t)));
4907 fold (build2 (TRUTH_ORIF_EXPR, type,
4908 optimize_minmax_comparison
4909 (build2 (EQ_EXPR, type, arg0, comp_const)),
4910 optimize_minmax_comparison
4911 (build2 (GT_EXPR, type, arg0, comp_const))));
4914 if (op_code == MAX_EXPR && consts_equal)
4915 /* MAX (X, 0) == 0 -> X <= 0 */
4916 return fold (build2 (LE_EXPR, type, inner, comp_const));
4918 else if (op_code == MAX_EXPR && consts_lt)
4919 /* MAX (X, 0) == 5 -> X == 5 */
4920 return fold (build2 (EQ_EXPR, type, inner, comp_const));
4922 else if (op_code == MAX_EXPR)
4923 /* MAX (X, 0) == -1 -> false */
4924 return omit_one_operand (type, integer_zero_node, inner);
4926 else if (consts_equal)
4927 /* MIN (X, 0) == 0 -> X >= 0 */
4928 return fold (build2 (GE_EXPR, type, inner, comp_const));
4931 /* MIN (X, 0) == 5 -> false */
4932 return omit_one_operand (type, integer_zero_node, inner);
4935 /* MIN (X, 0) == -1 -> X == -1 */
4936 return fold (build2 (EQ_EXPR, type, inner, comp_const));
4939 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
4940 /* MAX (X, 0) > 0 -> X > 0
4941 MAX (X, 0) > 5 -> X > 5 */
4942 return fold (build2 (GT_EXPR, type, inner, comp_const));
4944 else if (op_code == MAX_EXPR)
4945 /* MAX (X, 0) > -1 -> true */
4946 return omit_one_operand (type, integer_one_node, inner);
4948 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
4949 /* MIN (X, 0) > 0 -> false
4950 MIN (X, 0) > 5 -> false */
4951 return omit_one_operand (type, integer_zero_node, inner);
4954 /* MIN (X, 0) > -1 -> X > -1 */
4955 return fold (build2 (GT_EXPR, type, inner, comp_const));
4962 /* T is an integer expression that is being multiplied, divided, or taken a
4963 modulus (CODE says which and what kind of divide or modulus) by a
4964 constant C. See if we can eliminate that operation by folding it with
4965 other operations already in T. WIDE_TYPE, if non-null, is a type that
4966 should be used for the computation if wider than our type.
4968 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
4969 (X * 2) + (Y * 4). We must, however, be assured that either the original
4970 expression would not overflow or that overflow is undefined for the type
4971 in the language in question.
4973 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
4974 the machine has a multiply-accumulate insn or that this is part of an
4975 addressing calculation.
4977 If we return a non-null expression, it is an equivalent form of the
4978 original computation, but need not be in the original type. */
4981 extract_muldiv (tree t, tree c, enum tree_code code, tree wide_type)
4983 /* To avoid exponential search depth, refuse to allow recursion past
4984 three levels. Beyond that (1) it's highly unlikely that we'll find
4985 something interesting and (2) we've probably processed it before
4986 when we built the inner expression. */
4995 ret = extract_muldiv_1 (t, c, code, wide_type);
5002 extract_muldiv_1 (tree t, tree c, enum tree_code code, tree wide_type)
5004 tree type = TREE_TYPE (t);
5005 enum tree_code tcode = TREE_CODE (t);
5006 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
5007 > GET_MODE_SIZE (TYPE_MODE (type)))
5008 ? wide_type : type);
5010 int same_p = tcode == code;
5011 tree op0 = NULL_TREE, op1 = NULL_TREE;
5013 /* Don't deal with constants of zero here; they confuse the code below. */
5014 if (integer_zerop (c))
5017 if (TREE_CODE_CLASS (tcode) == '1')
5018 op0 = TREE_OPERAND (t, 0);
5020 if (TREE_CODE_CLASS (tcode) == '2')
5021 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
5023 /* Note that we need not handle conditional operations here since fold
5024 already handles those cases. So just do arithmetic here. */
5028 /* For a constant, we can always simplify if we are a multiply
5029 or (for divide and modulus) if it is a multiple of our constant. */
5030 if (code == MULT_EXPR
5031 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
5032 return const_binop (code, fold_convert (ctype, t),
5033 fold_convert (ctype, c), 0);
5036 case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
5037 /* If op0 is an expression ... */
5038 if ((TREE_CODE_CLASS (TREE_CODE (op0)) == '<'
5039 || TREE_CODE_CLASS (TREE_CODE (op0)) == '1'
5040 || TREE_CODE_CLASS (TREE_CODE (op0)) == '2'
5041 || TREE_CODE_CLASS (TREE_CODE (op0)) == 'e')
5042 /* ... and is unsigned, and its type is smaller than ctype,
5043 then we cannot pass through as widening. */
5044 && ((TYPE_UNSIGNED (TREE_TYPE (op0))
5045 && ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
5046 && TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
5047 && (GET_MODE_SIZE (TYPE_MODE (ctype))
5048 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
5049 /* ... or its type is larger than ctype,
5050 then we cannot pass through this truncation. */
5051 || (GET_MODE_SIZE (TYPE_MODE (ctype))
5052 < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0))))
5053 /* ... or signedness changes for division or modulus,
5054 then we cannot pass through this conversion. */
5055 || (code != MULT_EXPR
5056 && (TYPE_UNSIGNED (ctype)
5057 != TYPE_UNSIGNED (TREE_TYPE (op0))))))
5060 /* Pass the constant down and see if we can make a simplification. If
5061 we can, replace this expression with the inner simplification for
5062 possible later conversion to our or some other type. */
5063 if ((t2 = fold_convert (TREE_TYPE (op0), c)) != 0
5064 && TREE_CODE (t2) == INTEGER_CST
5065 && ! TREE_CONSTANT_OVERFLOW (t2)
5066 && (0 != (t1 = extract_muldiv (op0, t2, code,
5068 ? ctype : NULL_TREE))))
5072 case NEGATE_EXPR: case ABS_EXPR:
5073 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
5074 return fold (build1 (tcode, ctype, fold_convert (ctype, t1)));
5077 case MIN_EXPR: case MAX_EXPR:
5078 /* If widening the type changes the signedness, then we can't perform
5079 this optimization as that changes the result. */
5080 if (TYPE_UNSIGNED (ctype) != TYPE_UNSIGNED (type))
5083 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
5084 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0
5085 && (t2 = extract_muldiv (op1, c, code, wide_type)) != 0)
5087 if (tree_int_cst_sgn (c) < 0)
5088 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
5090 return fold (build2 (tcode, ctype, fold_convert (ctype, t1),
5091 fold_convert (ctype, t2)));
5095 case LSHIFT_EXPR: case RSHIFT_EXPR:
5096 /* If the second operand is constant, this is a multiplication
5097 or floor division, by a power of two, so we can treat it that
5098 way unless the multiplier or divisor overflows. */
5099 if (TREE_CODE (op1) == INTEGER_CST
5100 /* const_binop may not detect overflow correctly,
5101 so check for it explicitly here. */
5102 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
5103 && TREE_INT_CST_HIGH (op1) == 0
5104 && 0 != (t1 = fold_convert (ctype,
5105 const_binop (LSHIFT_EXPR,
5108 && ! TREE_OVERFLOW (t1))
5109 return extract_muldiv (build2 (tcode == LSHIFT_EXPR
5110 ? MULT_EXPR : FLOOR_DIV_EXPR,
5111 ctype, fold_convert (ctype, op0), t1),
5112 c, code, wide_type);
5115 case PLUS_EXPR: case MINUS_EXPR:
5116 /* See if we can eliminate the operation on both sides. If we can, we
5117 can return a new PLUS or MINUS. If we can't, the only remaining
5118 cases where we can do anything are if the second operand is a
5120 t1 = extract_muldiv (op0, c, code, wide_type);
5121 t2 = extract_muldiv (op1, c, code, wide_type);
5122 if (t1 != 0 && t2 != 0
5123 && (code == MULT_EXPR
5124 /* If not multiplication, we can only do this if both operands
5125 are divisible by c. */
5126 || (multiple_of_p (ctype, op0, c)
5127 && multiple_of_p (ctype, op1, c))))
5128 return fold (build2 (tcode, ctype, fold_convert (ctype, t1),
5129 fold_convert (ctype, t2)));
5131 /* If this was a subtraction, negate OP1 and set it to be an addition.
5132 This simplifies the logic below. */
5133 if (tcode == MINUS_EXPR)
5134 tcode = PLUS_EXPR, op1 = negate_expr (op1);
5136 if (TREE_CODE (op1) != INTEGER_CST)
5139 /* If either OP1 or C are negative, this optimization is not safe for
5140 some of the division and remainder types while for others we need
5141 to change the code. */
5142 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
5144 if (code == CEIL_DIV_EXPR)
5145 code = FLOOR_DIV_EXPR;
5146 else if (code == FLOOR_DIV_EXPR)
5147 code = CEIL_DIV_EXPR;
5148 else if (code != MULT_EXPR
5149 && code != CEIL_MOD_EXPR && code != FLOOR_MOD_EXPR)
5153 /* If it's a multiply or a division/modulus operation of a multiple
5154 of our constant, do the operation and verify it doesn't overflow. */
5155 if (code == MULT_EXPR
5156 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5158 op1 = const_binop (code, fold_convert (ctype, op1),
5159 fold_convert (ctype, c), 0);
5160 /* We allow the constant to overflow with wrapping semantics. */
5162 || (TREE_OVERFLOW (op1) && ! flag_wrapv))
5168 /* If we have an unsigned type is not a sizetype, we cannot widen
5169 the operation since it will change the result if the original
5170 computation overflowed. */
5171 if (TYPE_UNSIGNED (ctype)
5172 && ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
5176 /* If we were able to eliminate our operation from the first side,
5177 apply our operation to the second side and reform the PLUS. */
5178 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
5179 return fold (build2 (tcode, ctype, fold_convert (ctype, t1), op1));
5181 /* The last case is if we are a multiply. In that case, we can
5182 apply the distributive law to commute the multiply and addition
5183 if the multiplication of the constants doesn't overflow. */
5184 if (code == MULT_EXPR)
5185 return fold (build2 (tcode, ctype,
5186 fold (build2 (code, ctype,
5187 fold_convert (ctype, op0),
5188 fold_convert (ctype, c))),
5194 /* We have a special case here if we are doing something like
5195 (C * 8) % 4 since we know that's zero. */
5196 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
5197 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
5198 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
5199 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5200 return omit_one_operand (type, integer_zero_node, op0);
5202 /* ... fall through ... */
5204 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
5205 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
5206 /* If we can extract our operation from the LHS, do so and return a
5207 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
5208 do something only if the second operand is a constant. */
5210 && (t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
5211 return fold (build2 (tcode, ctype, fold_convert (ctype, t1),
5212 fold_convert (ctype, op1)));
5213 else if (tcode == MULT_EXPR && code == MULT_EXPR
5214 && (t1 = extract_muldiv (op1, c, code, wide_type)) != 0)
5215 return fold (build2 (tcode, ctype, fold_convert (ctype, op0),
5216 fold_convert (ctype, t1)));
5217 else if (TREE_CODE (op1) != INTEGER_CST)
5220 /* If these are the same operation types, we can associate them
5221 assuming no overflow. */
5223 && 0 != (t1 = const_binop (MULT_EXPR, fold_convert (ctype, op1),
5224 fold_convert (ctype, c), 0))
5225 && ! TREE_OVERFLOW (t1))
5226 return fold (build2 (tcode, ctype, fold_convert (ctype, op0), t1));
5228 /* If these operations "cancel" each other, we have the main
5229 optimizations of this pass, which occur when either constant is a
5230 multiple of the other, in which case we replace this with either an
5231 operation or CODE or TCODE.
5233 If we have an unsigned type that is not a sizetype, we cannot do
5234 this since it will change the result if the original computation
5236 if ((! TYPE_UNSIGNED (ctype)
5237 || (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
5239 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
5240 || (tcode == MULT_EXPR
5241 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
5242 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR)))
5244 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5245 return fold (build2 (tcode, ctype, fold_convert (ctype, op0),
5246 fold_convert (ctype,
5247 const_binop (TRUNC_DIV_EXPR,
5249 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
5250 return fold (build2 (code, ctype, fold_convert (ctype, op0),
5251 fold_convert (ctype,
5252 const_binop (TRUNC_DIV_EXPR,
5264 /* Return a node which has the indicated constant VALUE (either 0 or
5265 1), and is of the indicated TYPE. */
5268 constant_boolean_node (int value, tree type)
5270 if (type == integer_type_node)
5271 return value ? integer_one_node : integer_zero_node;
5272 else if (type == boolean_type_node)
5273 return value ? boolean_true_node : boolean_false_node;
5274 else if (TREE_CODE (type) == BOOLEAN_TYPE)
5275 return lang_hooks.truthvalue_conversion (value ? integer_one_node
5276 : integer_zero_node);
5279 tree t = build_int_2 (value, 0);
5281 TREE_TYPE (t) = type;
5286 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
5287 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
5288 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
5289 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
5290 COND is the first argument to CODE; otherwise (as in the example
5291 given here), it is the second argument. TYPE is the type of the
5292 original expression. Return NULL_TREE if no simplification is
5296 fold_binary_op_with_conditional_arg (enum tree_code code, tree type,
5297 tree cond, tree arg, int cond_first_p)
5299 tree test, true_value, false_value;
5300 tree lhs = NULL_TREE;
5301 tree rhs = NULL_TREE;
5303 /* This transformation is only worthwhile if we don't have to wrap
5304 arg in a SAVE_EXPR, and the operation can be simplified on atleast
5305 one of the branches once its pushed inside the COND_EXPR. */
5306 if (!TREE_CONSTANT (arg))
5309 if (TREE_CODE (cond) == COND_EXPR)
5311 test = TREE_OPERAND (cond, 0);
5312 true_value = TREE_OPERAND (cond, 1);
5313 false_value = TREE_OPERAND (cond, 2);
5314 /* If this operand throws an expression, then it does not make
5315 sense to try to perform a logical or arithmetic operation
5317 if (VOID_TYPE_P (TREE_TYPE (true_value)))
5319 if (VOID_TYPE_P (TREE_TYPE (false_value)))
5324 tree testtype = TREE_TYPE (cond);
5326 true_value = constant_boolean_node (true, testtype);
5327 false_value = constant_boolean_node (false, testtype);
5331 lhs = fold (cond_first_p ? build2 (code, type, true_value, arg)
5332 : build2 (code, type, arg, true_value));
5334 rhs = fold (cond_first_p ? build2 (code, type, false_value, arg)
5335 : build2 (code, type, arg, false_value));
5337 test = fold (build3 (COND_EXPR, type, test, lhs, rhs));
5338 return fold_convert (type, test);
5342 /* Subroutine of fold() that checks for the addition of +/- 0.0.
5344 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
5345 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
5346 ADDEND is the same as X.
5348 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
5349 and finite. The problematic cases are when X is zero, and its mode
5350 has signed zeros. In the case of rounding towards -infinity,
5351 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
5352 modes, X + 0 is not the same as X because -0 + 0 is 0. */
5355 fold_real_zero_addition_p (tree type, tree addend, int negate)
5357 if (!real_zerop (addend))
5360 /* Don't allow the fold with -fsignaling-nans. */
5361 if (HONOR_SNANS (TYPE_MODE (type)))
5364 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
5365 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
5368 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
5369 if (TREE_CODE (addend) == REAL_CST
5370 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
5373 /* The mode has signed zeros, and we have to honor their sign.
5374 In this situation, there is only one case we can return true for.
5375 X - 0 is the same as X unless rounding towards -infinity is
5377 return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
5380 /* Subroutine of fold() that checks comparisons of built-in math
5381 functions against real constants.
5383 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
5384 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
5385 is the type of the result and ARG0 and ARG1 are the operands of the
5386 comparison. ARG1 must be a TREE_REAL_CST.
5388 The function returns the constant folded tree if a simplification
5389 can be made, and NULL_TREE otherwise. */
5392 fold_mathfn_compare (enum built_in_function fcode, enum tree_code code,
5393 tree type, tree arg0, tree arg1)
5397 if (BUILTIN_SQRT_P (fcode))
5399 tree arg = TREE_VALUE (TREE_OPERAND (arg0, 1));
5400 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg0));
5402 c = TREE_REAL_CST (arg1);
5403 if (REAL_VALUE_NEGATIVE (c))
5405 /* sqrt(x) < y is always false, if y is negative. */
5406 if (code == EQ_EXPR || code == LT_EXPR || code == LE_EXPR)
5407 return omit_one_operand (type, integer_zero_node, arg);
5409 /* sqrt(x) > y is always true, if y is negative and we
5410 don't care about NaNs, i.e. negative values of x. */
5411 if (code == NE_EXPR || !HONOR_NANS (mode))
5412 return omit_one_operand (type, integer_one_node, arg);
5414 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
5415 return fold (build2 (GE_EXPR, type, arg,
5416 build_real (TREE_TYPE (arg), dconst0)));
5418 else if (code == GT_EXPR || code == GE_EXPR)
5422 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
5423 real_convert (&c2, mode, &c2);
5425 if (REAL_VALUE_ISINF (c2))
5427 /* sqrt(x) > y is x == +Inf, when y is very large. */
5428 if (HONOR_INFINITIES (mode))
5429 return fold (build2 (EQ_EXPR, type, arg,
5430 build_real (TREE_TYPE (arg), c2)));
5432 /* sqrt(x) > y is always false, when y is very large
5433 and we don't care about infinities. */
5434 return omit_one_operand (type, integer_zero_node, arg);
5437 /* sqrt(x) > c is the same as x > c*c. */
5438 return fold (build2 (code, type, arg,
5439 build_real (TREE_TYPE (arg), c2)));
5441 else if (code == LT_EXPR || code == LE_EXPR)
5445 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
5446 real_convert (&c2, mode, &c2);
5448 if (REAL_VALUE_ISINF (c2))
5450 /* sqrt(x) < y is always true, when y is a very large
5451 value and we don't care about NaNs or Infinities. */
5452 if (! HONOR_NANS (mode) && ! HONOR_INFINITIES (mode))
5453 return omit_one_operand (type, integer_one_node, arg);
5455 /* sqrt(x) < y is x != +Inf when y is very large and we
5456 don't care about NaNs. */
5457 if (! HONOR_NANS (mode))
5458 return fold (build2 (NE_EXPR, type, arg,
5459 build_real (TREE_TYPE (arg), c2)));
5461 /* sqrt(x) < y is x >= 0 when y is very large and we
5462 don't care about Infinities. */
5463 if (! HONOR_INFINITIES (mode))
5464 return fold (build2 (GE_EXPR, type, arg,
5465 build_real (TREE_TYPE (arg), dconst0)));
5467 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
5468 if (lang_hooks.decls.global_bindings_p () != 0
5469 || CONTAINS_PLACEHOLDER_P (arg))
5472 arg = save_expr (arg);
5473 return fold (build2 (TRUTH_ANDIF_EXPR, type,
5474 fold (build2 (GE_EXPR, type, arg,
5475 build_real (TREE_TYPE (arg),
5477 fold (build2 (NE_EXPR, type, arg,
5478 build_real (TREE_TYPE (arg),
5482 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
5483 if (! HONOR_NANS (mode))
5484 return fold (build2 (code, type, arg,
5485 build_real (TREE_TYPE (arg), c2)));
5487 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
5488 if (lang_hooks.decls.global_bindings_p () == 0
5489 && ! CONTAINS_PLACEHOLDER_P (arg))
5491 arg = save_expr (arg);
5492 return fold (build2 (TRUTH_ANDIF_EXPR, type,
5493 fold (build2 (GE_EXPR, type, arg,
5494 build_real (TREE_TYPE (arg),
5496 fold (build2 (code, type, arg,
5497 build_real (TREE_TYPE (arg),
5506 /* Subroutine of fold() that optimizes comparisons against Infinities,
5507 either +Inf or -Inf.
5509 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
5510 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
5511 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
5513 The function returns the constant folded tree if a simplification
5514 can be made, and NULL_TREE otherwise. */
5517 fold_inf_compare (enum tree_code code, tree type, tree arg0, tree arg1)
5519 enum machine_mode mode;
5520 REAL_VALUE_TYPE max;
5524 mode = TYPE_MODE (TREE_TYPE (arg0));
5526 /* For negative infinity swap the sense of the comparison. */
5527 neg = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1));
5529 code = swap_tree_comparison (code);
5534 /* x > +Inf is always false, if with ignore sNANs. */
5535 if (HONOR_SNANS (mode))
5537 return omit_one_operand (type, integer_zero_node, arg0);
5540 /* x <= +Inf is always true, if we don't case about NaNs. */
5541 if (! HONOR_NANS (mode))
5542 return omit_one_operand (type, integer_one_node, arg0);
5544 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
5545 if (lang_hooks.decls.global_bindings_p () == 0
5546 && ! CONTAINS_PLACEHOLDER_P (arg0))
5548 arg0 = save_expr (arg0);
5549 return fold (build2 (EQ_EXPR, type, arg0, arg0));
5555 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
5556 real_maxval (&max, neg, mode);
5557 return fold (build2 (neg ? LT_EXPR : GT_EXPR, type,
5558 arg0, build_real (TREE_TYPE (arg0), max)));
5561 /* x < +Inf is always equal to x <= DBL_MAX. */
5562 real_maxval (&max, neg, mode);
5563 return fold (build2 (neg ? GE_EXPR : LE_EXPR, type,
5564 arg0, build_real (TREE_TYPE (arg0), max)));
5567 /* x != +Inf is always equal to !(x > DBL_MAX). */
5568 real_maxval (&max, neg, mode);
5569 if (! HONOR_NANS (mode))
5570 return fold (build2 (neg ? GE_EXPR : LE_EXPR, type,
5571 arg0, build_real (TREE_TYPE (arg0), max)));
5573 /* The transformation below creates non-gimple code and thus is
5574 not appropriate if we are in gimple form. */
5578 temp = fold (build2 (neg ? LT_EXPR : GT_EXPR, type,
5579 arg0, build_real (TREE_TYPE (arg0), max)));
5580 return fold (build1 (TRUTH_NOT_EXPR, type, temp));
5589 /* Subroutine of fold() that optimizes comparisons of a division by
5590 a nonzero integer constant against an integer constant, i.e.
5593 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
5594 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
5595 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
5597 The function returns the constant folded tree if a simplification
5598 can be made, and NULL_TREE otherwise. */
5601 fold_div_compare (enum tree_code code, tree type, tree arg0, tree arg1)
5603 tree prod, tmp, hi, lo;
5604 tree arg00 = TREE_OPERAND (arg0, 0);
5605 tree arg01 = TREE_OPERAND (arg0, 1);
5606 unsigned HOST_WIDE_INT lpart;
5607 HOST_WIDE_INT hpart;
5610 /* We have to do this the hard way to detect unsigned overflow.
5611 prod = int_const_binop (MULT_EXPR, arg01, arg1, 0); */
5612 overflow = mul_double (TREE_INT_CST_LOW (arg01),
5613 TREE_INT_CST_HIGH (arg01),
5614 TREE_INT_CST_LOW (arg1),
5615 TREE_INT_CST_HIGH (arg1), &lpart, &hpart);
5616 prod = build_int_2 (lpart, hpart);
5617 TREE_TYPE (prod) = TREE_TYPE (arg00);
5618 TREE_OVERFLOW (prod) = force_fit_type (prod, overflow)
5619 || TREE_INT_CST_HIGH (prod) != hpart
5620 || TREE_INT_CST_LOW (prod) != lpart;
5621 TREE_CONSTANT_OVERFLOW (prod) = TREE_OVERFLOW (prod);
5623 if (TYPE_UNSIGNED (TREE_TYPE (arg0)))
5625 tmp = int_const_binop (MINUS_EXPR, arg01, integer_one_node, 0);
5628 /* Likewise hi = int_const_binop (PLUS_EXPR, prod, tmp, 0). */
5629 overflow = add_double (TREE_INT_CST_LOW (prod),
5630 TREE_INT_CST_HIGH (prod),
5631 TREE_INT_CST_LOW (tmp),
5632 TREE_INT_CST_HIGH (tmp),
5634 hi = build_int_2 (lpart, hpart);
5635 TREE_TYPE (hi) = TREE_TYPE (arg00);
5636 TREE_OVERFLOW (hi) = force_fit_type (hi, overflow)
5637 || TREE_INT_CST_HIGH (hi) != hpart
5638 || TREE_INT_CST_LOW (hi) != lpart
5639 || TREE_OVERFLOW (prod);
5640 TREE_CONSTANT_OVERFLOW (hi) = TREE_OVERFLOW (hi);
5642 else if (tree_int_cst_sgn (arg01) >= 0)
5644 tmp = int_const_binop (MINUS_EXPR, arg01, integer_one_node, 0);
5645 switch (tree_int_cst_sgn (arg1))
5648 lo = int_const_binop (MINUS_EXPR, prod, tmp, 0);
5653 lo = fold_negate_const (tmp, TREE_TYPE (arg0));
5658 hi = int_const_binop (PLUS_EXPR, prod, tmp, 0);
5668 tmp = int_const_binop (PLUS_EXPR, arg01, integer_one_node, 0);
5669 switch (tree_int_cst_sgn (arg1))
5672 hi = int_const_binop (MINUS_EXPR, prod, tmp, 0);
5677 hi = fold_negate_const (tmp, TREE_TYPE (arg0));
5682 lo = int_const_binop (PLUS_EXPR, prod, tmp, 0);
5694 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
5695 return omit_one_operand (type, integer_zero_node, arg00);
5696 if (TREE_OVERFLOW (hi))
5697 return fold (build2 (GE_EXPR, type, arg00, lo));
5698 if (TREE_OVERFLOW (lo))
5699 return fold (build2 (LE_EXPR, type, arg00, hi));
5700 return build_range_check (type, arg00, 1, lo, hi);
5703 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
5704 return omit_one_operand (type, integer_one_node, arg00);
5705 if (TREE_OVERFLOW (hi))
5706 return fold (build2 (LT_EXPR, type, arg00, lo));
5707 if (TREE_OVERFLOW (lo))
5708 return fold (build2 (GT_EXPR, type, arg00, hi));
5709 return build_range_check (type, arg00, 0, lo, hi);
5712 if (TREE_OVERFLOW (lo))
5713 return omit_one_operand (type, integer_zero_node, arg00);
5714 return fold (build2 (LT_EXPR, type, arg00, lo));
5717 if (TREE_OVERFLOW (hi))
5718 return omit_one_operand (type, integer_one_node, arg00);
5719 return fold (build2 (LE_EXPR, type, arg00, hi));
5722 if (TREE_OVERFLOW (hi))
5723 return omit_one_operand (type, integer_zero_node, arg00);
5724 return fold (build2 (GT_EXPR, type, arg00, hi));
5727 if (TREE_OVERFLOW (lo))
5728 return omit_one_operand (type, integer_one_node, arg00);
5729 return fold (build2 (GE_EXPR, type, arg00, lo));
5739 /* If CODE with arguments ARG0 and ARG1 represents a single bit
5740 equality/inequality test, then return a simplified form of
5741 the test using shifts and logical operations. Otherwise return
5742 NULL. TYPE is the desired result type. */
5745 fold_single_bit_test (enum tree_code code, tree arg0, tree arg1,
5748 /* If this is a TRUTH_NOT_EXPR, it may have a single bit test inside
5750 if (code == TRUTH_NOT_EXPR)
5752 code = TREE_CODE (arg0);
5753 if (code != NE_EXPR && code != EQ_EXPR)
5756 /* Extract the arguments of the EQ/NE. */
5757 arg1 = TREE_OPERAND (arg0, 1);
5758 arg0 = TREE_OPERAND (arg0, 0);
5760 /* This requires us to invert the code. */
5761 code = (code == EQ_EXPR ? NE_EXPR : EQ_EXPR);
5764 /* If this is testing a single bit, we can optimize the test. */
5765 if ((code == NE_EXPR || code == EQ_EXPR)
5766 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
5767 && integer_pow2p (TREE_OPERAND (arg0, 1)))
5769 tree inner = TREE_OPERAND (arg0, 0);
5770 tree type = TREE_TYPE (arg0);
5771 int bitnum = tree_log2 (TREE_OPERAND (arg0, 1));
5772 enum machine_mode operand_mode = TYPE_MODE (type);
5774 tree signed_type, unsigned_type, intermediate_type;
5777 /* If we have (A & C) != 0 where C is the sign bit of A, convert
5778 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
5779 arg00 = sign_bit_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
5780 if (arg00 != NULL_TREE
5781 /* This is only a win if casting to a signed type is cheap,
5782 i.e. when arg00's type is not a partial mode. */
5783 && TYPE_PRECISION (TREE_TYPE (arg00))
5784 == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg00))))
5786 tree stype = lang_hooks.types.signed_type (TREE_TYPE (arg00));
5787 return fold (build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
5788 result_type, fold_convert (stype, arg00),
5789 fold_convert (stype, integer_zero_node)));
5792 /* Otherwise we have (A & C) != 0 where C is a single bit,
5793 convert that into ((A >> C2) & 1). Where C2 = log2(C).
5794 Similarly for (A & C) == 0. */
5796 /* If INNER is a right shift of a constant and it plus BITNUM does
5797 not overflow, adjust BITNUM and INNER. */
5798 if (TREE_CODE (inner) == RSHIFT_EXPR
5799 && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST
5800 && TREE_INT_CST_HIGH (TREE_OPERAND (inner, 1)) == 0
5801 && bitnum < TYPE_PRECISION (type)
5802 && 0 > compare_tree_int (TREE_OPERAND (inner, 1),
5803 bitnum - TYPE_PRECISION (type)))
5805 bitnum += TREE_INT_CST_LOW (TREE_OPERAND (inner, 1));
5806 inner = TREE_OPERAND (inner, 0);
5809 /* If we are going to be able to omit the AND below, we must do our
5810 operations as unsigned. If we must use the AND, we have a choice.
5811 Normally unsigned is faster, but for some machines signed is. */
5812 #ifdef LOAD_EXTEND_OP
5813 ops_unsigned = (LOAD_EXTEND_OP (operand_mode) == SIGN_EXTEND ? 0 : 1);
5818 signed_type = lang_hooks.types.type_for_mode (operand_mode, 0);
5819 unsigned_type = lang_hooks.types.type_for_mode (operand_mode, 1);
5820 intermediate_type = ops_unsigned ? unsigned_type : signed_type;
5821 inner = fold_convert (intermediate_type, inner);
5824 inner = build2 (RSHIFT_EXPR, intermediate_type,
5825 inner, size_int (bitnum));
5827 if (code == EQ_EXPR)
5828 inner = build2 (BIT_XOR_EXPR, intermediate_type,
5829 inner, integer_one_node);
5831 /* Put the AND last so it can combine with more things. */
5832 inner = build2 (BIT_AND_EXPR, intermediate_type,
5833 inner, integer_one_node);
5835 /* Make sure to return the proper type. */
5836 inner = fold_convert (result_type, inner);
5843 /* Check whether we are allowed to reorder operands arg0 and arg1,
5844 such that the evaluation of arg1 occurs before arg0. */
5847 reorder_operands_p (tree arg0, tree arg1)
5849 if (! flag_evaluation_order)
5851 if (TREE_CONSTANT (arg0) || TREE_CONSTANT (arg1))
5853 return ! TREE_SIDE_EFFECTS (arg0)
5854 && ! TREE_SIDE_EFFECTS (arg1);
5857 /* Test whether it is preferable two swap two operands, ARG0 and
5858 ARG1, for example because ARG0 is an integer constant and ARG1
5859 isn't. If REORDER is true, only recommend swapping if we can
5860 evaluate the operands in reverse order. */
5863 tree_swap_operands_p (tree arg0, tree arg1, bool reorder)
5865 STRIP_SIGN_NOPS (arg0);
5866 STRIP_SIGN_NOPS (arg1);
5868 if (TREE_CODE (arg1) == INTEGER_CST)
5870 if (TREE_CODE (arg0) == INTEGER_CST)
5873 if (TREE_CODE (arg1) == REAL_CST)
5875 if (TREE_CODE (arg0) == REAL_CST)
5878 if (TREE_CODE (arg1) == COMPLEX_CST)
5880 if (TREE_CODE (arg0) == COMPLEX_CST)
5883 if (TREE_CONSTANT (arg1))
5885 if (TREE_CONSTANT (arg0))
5891 if (reorder && flag_evaluation_order
5892 && (TREE_SIDE_EFFECTS (arg0) || TREE_SIDE_EFFECTS (arg1)))
5900 if (reorder && flag_evaluation_order
5901 && (TREE_SIDE_EFFECTS (arg0) || TREE_SIDE_EFFECTS (arg1)))
5909 /* It is preferable to swap two SSA_NAME to ensure a canonical form
5910 for commutative and comparison operators. Ensuring a canonical
5911 form allows the optimizers to find additional redundancies without
5912 having to explicitly check for both orderings. */
5913 if (TREE_CODE (arg0) == SSA_NAME
5914 && TREE_CODE (arg1) == SSA_NAME
5915 && SSA_NAME_VERSION (arg0) > SSA_NAME_VERSION (arg1))
5921 /* Perform constant folding and related simplification of EXPR.
5922 The related simplifications include x*1 => x, x*0 => 0, etc.,
5923 and application of the associative law.
5924 NOP_EXPR conversions may be removed freely (as long as we
5925 are careful not to change the type of the overall expression).
5926 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
5927 but we can constant-fold them if they have constant operands. */
5929 #ifdef ENABLE_FOLD_CHECKING
5930 # define fold(x) fold_1 (x)
5931 static tree fold_1 (tree);
5937 const tree t = expr;
5938 const tree type = TREE_TYPE (expr);
5939 tree t1 = NULL_TREE;
5941 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
5942 enum tree_code code = TREE_CODE (t);
5943 int kind = TREE_CODE_CLASS (code);
5945 /* WINS will be nonzero when the switch is done
5946 if all operands are constant. */
5949 /* Don't try to process an RTL_EXPR since its operands aren't trees.
5950 Likewise for a SAVE_EXPR that's already been evaluated. */
5951 if (code == RTL_EXPR || (code == SAVE_EXPR && SAVE_EXPR_RTL (t) != 0))
5954 /* Return right away if a constant. */
5958 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
5962 /* Special case for conversion ops that can have fixed point args. */
5963 arg0 = TREE_OPERAND (t, 0);
5965 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
5967 STRIP_SIGN_NOPS (arg0);
5969 if (arg0 != 0 && TREE_CODE (arg0) == COMPLEX_CST)
5970 subop = TREE_REALPART (arg0);
5974 if (subop != 0 && TREE_CODE (subop) != INTEGER_CST
5975 && TREE_CODE (subop) != REAL_CST)
5976 /* Note that TREE_CONSTANT isn't enough:
5977 static var addresses are constant but we can't
5978 do arithmetic on them. */
5981 else if (IS_EXPR_CODE_CLASS (kind))
5983 int len = first_rtl_op (code);
5985 for (i = 0; i < len; i++)
5987 tree op = TREE_OPERAND (t, i);
5991 continue; /* Valid for CALL_EXPR, at least. */
5993 /* Strip any conversions that don't change the mode. This is
5994 safe for every expression, except for a comparison expression
5995 because its signedness is derived from its operands. So, in
5996 the latter case, only strip conversions that don't change the
5999 Note that this is done as an internal manipulation within the
6000 constant folder, in order to find the simplest representation
6001 of the arguments so that their form can be studied. In any
6002 cases, the appropriate type conversions should be put back in
6003 the tree that will get out of the constant folder. */
6005 STRIP_SIGN_NOPS (op);
6009 if (TREE_CODE (op) == COMPLEX_CST)
6010 subop = TREE_REALPART (op);
6014 if (TREE_CODE (subop) != INTEGER_CST
6015 && TREE_CODE (subop) != REAL_CST)
6016 /* Note that TREE_CONSTANT isn't enough:
6017 static var addresses are constant but we can't
6018 do arithmetic on them. */
6028 /* If this is a commutative operation, and ARG0 is a constant, move it
6029 to ARG1 to reduce the number of tests below. */
6030 if (commutative_tree_code (code)
6031 && tree_swap_operands_p (arg0, arg1, true))
6032 return fold (build2 (code, type, TREE_OPERAND (t, 1),
6033 TREE_OPERAND (t, 0)));
6035 /* Now WINS is set as described above,
6036 ARG0 is the first operand of EXPR,
6037 and ARG1 is the second operand (if it has more than one operand).
6039 First check for cases where an arithmetic operation is applied to a
6040 compound, conditional, or comparison operation. Push the arithmetic
6041 operation inside the compound or conditional to see if any folding
6042 can then be done. Convert comparison to conditional for this purpose.
6043 The also optimizes non-constant cases that used to be done in
6046 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
6047 one of the operands is a comparison and the other is a comparison, a
6048 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
6049 code below would make the expression more complex. Change it to a
6050 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
6051 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
6053 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
6054 || code == EQ_EXPR || code == NE_EXPR)
6055 && ((truth_value_p (TREE_CODE (arg0))
6056 && (truth_value_p (TREE_CODE (arg1))
6057 || (TREE_CODE (arg1) == BIT_AND_EXPR
6058 && integer_onep (TREE_OPERAND (arg1, 1)))))
6059 || (truth_value_p (TREE_CODE (arg1))
6060 && (truth_value_p (TREE_CODE (arg0))
6061 || (TREE_CODE (arg0) == BIT_AND_EXPR
6062 && integer_onep (TREE_OPERAND (arg0, 1)))))))
6064 tem = fold (build2 (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
6065 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
6067 type, fold_convert (boolean_type_node, arg0),
6068 fold_convert (boolean_type_node, arg1)));
6070 if (code == EQ_EXPR)
6071 tem = invert_truthvalue (tem);
6076 if (TREE_CODE_CLASS (code) == '1')
6078 if (TREE_CODE (arg0) == COMPOUND_EXPR)
6079 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
6080 fold (build1 (code, type, TREE_OPERAND (arg0, 1))));
6081 else if (TREE_CODE (arg0) == COND_EXPR)
6083 tree arg01 = TREE_OPERAND (arg0, 1);
6084 tree arg02 = TREE_OPERAND (arg0, 2);
6085 if (! VOID_TYPE_P (TREE_TYPE (arg01)))
6086 arg01 = fold (build1 (code, type, arg01));
6087 if (! VOID_TYPE_P (TREE_TYPE (arg02)))
6088 arg02 = fold (build1 (code, type, arg02));
6089 tem = fold (build3 (COND_EXPR, type, TREE_OPERAND (arg0, 0),
6092 /* If this was a conversion, and all we did was to move into
6093 inside the COND_EXPR, bring it back out. But leave it if
6094 it is a conversion from integer to integer and the
6095 result precision is no wider than a word since such a
6096 conversion is cheap and may be optimized away by combine,
6097 while it couldn't if it were outside the COND_EXPR. Then return
6098 so we don't get into an infinite recursion loop taking the
6099 conversion out and then back in. */
6101 if ((code == NOP_EXPR || code == CONVERT_EXPR
6102 || code == NON_LVALUE_EXPR)
6103 && TREE_CODE (tem) == COND_EXPR
6104 && TREE_CODE (TREE_OPERAND (tem, 1)) == code
6105 && TREE_CODE (TREE_OPERAND (tem, 2)) == code
6106 && ! VOID_TYPE_P (TREE_OPERAND (tem, 1))
6107 && ! VOID_TYPE_P (TREE_OPERAND (tem, 2))
6108 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))
6109 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 2), 0)))
6110 && ! (INTEGRAL_TYPE_P (TREE_TYPE (tem))
6112 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))))
6113 && TYPE_PRECISION (TREE_TYPE (tem)) <= BITS_PER_WORD))
6114 tem = build1 (code, type,
6116 TREE_TYPE (TREE_OPERAND
6117 (TREE_OPERAND (tem, 1), 0)),
6118 TREE_OPERAND (tem, 0),
6119 TREE_OPERAND (TREE_OPERAND (tem, 1), 0),
6120 TREE_OPERAND (TREE_OPERAND (tem, 2), 0)));
6123 else if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<')
6125 if (TREE_CODE (type) == BOOLEAN_TYPE)
6127 arg0 = copy_node (arg0);
6128 TREE_TYPE (arg0) = type;
6131 else if (TREE_CODE (type) != INTEGER_TYPE)
6132 return fold (build3 (COND_EXPR, type, arg0,
6133 fold (build1 (code, type,
6135 fold (build1 (code, type,
6136 integer_zero_node))));
6139 else if (TREE_CODE_CLASS (code) == '<'
6140 && TREE_CODE (arg0) == COMPOUND_EXPR)
6141 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
6142 fold (build2 (code, type, TREE_OPERAND (arg0, 1), arg1)));
6143 else if (TREE_CODE_CLASS (code) == '<'
6144 && TREE_CODE (arg1) == COMPOUND_EXPR)
6145 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
6146 fold (build2 (code, type, arg0, TREE_OPERAND (arg1, 1))));
6147 else if (TREE_CODE_CLASS (code) == '2'
6148 || TREE_CODE_CLASS (code) == '<')
6150 if (TREE_CODE (arg0) == COMPOUND_EXPR)
6151 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
6152 fold (build2 (code, type, TREE_OPERAND (arg0, 1),
6154 if (TREE_CODE (arg1) == COMPOUND_EXPR
6155 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
6156 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
6157 fold (build2 (code, type,
6158 arg0, TREE_OPERAND (arg1, 1))));
6160 if (TREE_CODE (arg0) == COND_EXPR
6161 || TREE_CODE_CLASS (TREE_CODE (arg0)) == '<')
6163 tem = fold_binary_op_with_conditional_arg (code, type, arg0, arg1,
6164 /*cond_first_p=*/1);
6165 if (tem != NULL_TREE)
6169 if (TREE_CODE (arg1) == COND_EXPR
6170 || TREE_CODE_CLASS (TREE_CODE (arg1)) == '<')
6172 tem = fold_binary_op_with_conditional_arg (code, type, arg1, arg0,
6173 /*cond_first_p=*/0);
6174 if (tem != NULL_TREE)
6182 return fold (DECL_INITIAL (t));
6187 case FIX_TRUNC_EXPR:
6189 case FIX_FLOOR_EXPR:
6190 case FIX_ROUND_EXPR:
6191 if (TREE_TYPE (TREE_OPERAND (t, 0)) == type)
6192 return TREE_OPERAND (t, 0);
6194 /* Handle cases of two conversions in a row. */
6195 if (TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
6196 || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR)
6198 tree inside_type = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
6199 tree inter_type = TREE_TYPE (TREE_OPERAND (t, 0));
6200 int inside_int = INTEGRAL_TYPE_P (inside_type);
6201 int inside_ptr = POINTER_TYPE_P (inside_type);
6202 int inside_float = FLOAT_TYPE_P (inside_type);
6203 unsigned int inside_prec = TYPE_PRECISION (inside_type);
6204 int inside_unsignedp = TYPE_UNSIGNED (inside_type);
6205 int inter_int = INTEGRAL_TYPE_P (inter_type);
6206 int inter_ptr = POINTER_TYPE_P (inter_type);
6207 int inter_float = FLOAT_TYPE_P (inter_type);
6208 unsigned int inter_prec = TYPE_PRECISION (inter_type);
6209 int inter_unsignedp = TYPE_UNSIGNED (inter_type);
6210 int final_int = INTEGRAL_TYPE_P (type);
6211 int final_ptr = POINTER_TYPE_P (type);
6212 int final_float = FLOAT_TYPE_P (type);
6213 unsigned int final_prec = TYPE_PRECISION (type);
6214 int final_unsignedp = TYPE_UNSIGNED (type);
6216 /* In addition to the cases of two conversions in a row
6217 handled below, if we are converting something to its own
6218 type via an object of identical or wider precision, neither
6219 conversion is needed. */
6220 if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (type)
6221 && ((inter_int && final_int) || (inter_float && final_float))
6222 && inter_prec >= final_prec)
6223 return fold (build1 (code, type,
6224 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
6226 /* Likewise, if the intermediate and final types are either both
6227 float or both integer, we don't need the middle conversion if
6228 it is wider than the final type and doesn't change the signedness
6229 (for integers). Avoid this if the final type is a pointer
6230 since then we sometimes need the inner conversion. Likewise if
6231 the outer has a precision not equal to the size of its mode. */
6232 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
6233 || (inter_float && inside_float))
6234 && inter_prec >= inside_prec
6235 && (inter_float || inter_unsignedp == inside_unsignedp)
6236 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
6237 && TYPE_MODE (type) == TYPE_MODE (inter_type))
6239 return fold (build1 (code, type,
6240 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
6242 /* If we have a sign-extension of a zero-extended value, we can
6243 replace that by a single zero-extension. */
6244 if (inside_int && inter_int && final_int
6245 && inside_prec < inter_prec && inter_prec < final_prec
6246 && inside_unsignedp && !inter_unsignedp)
6247 return fold (build1 (code, type,
6248 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
6250 /* Two conversions in a row are not needed unless:
6251 - some conversion is floating-point (overstrict for now), or
6252 - the intermediate type is narrower than both initial and
6254 - the intermediate type and innermost type differ in signedness,
6255 and the outermost type is wider than the intermediate, or
6256 - the initial type is a pointer type and the precisions of the
6257 intermediate and final types differ, or
6258 - the final type is a pointer type and the precisions of the
6259 initial and intermediate types differ. */
6260 if (! inside_float && ! inter_float && ! final_float
6261 && (inter_prec > inside_prec || inter_prec > final_prec)
6262 && ! (inside_int && inter_int
6263 && inter_unsignedp != inside_unsignedp
6264 && inter_prec < final_prec)
6265 && ((inter_unsignedp && inter_prec > inside_prec)
6266 == (final_unsignedp && final_prec > inter_prec))
6267 && ! (inside_ptr && inter_prec != final_prec)
6268 && ! (final_ptr && inside_prec != inter_prec)
6269 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
6270 && TYPE_MODE (type) == TYPE_MODE (inter_type))
6272 return fold (build1 (code, type,
6273 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
6276 if (TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR
6277 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t, 0), 1))
6278 /* Detect assigning a bitfield. */
6279 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) == COMPONENT_REF
6280 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 1))))
6282 /* Don't leave an assignment inside a conversion
6283 unless assigning a bitfield. */
6284 tree prev = TREE_OPERAND (t, 0);
6285 tem = copy_node (t);
6286 TREE_OPERAND (tem, 0) = TREE_OPERAND (prev, 1);
6287 /* First do the assignment, then return converted constant. */
6288 tem = build2 (COMPOUND_EXPR, TREE_TYPE (tem), prev, fold (tem));
6289 TREE_NO_WARNING (tem) = 1;
6290 TREE_USED (tem) = 1;
6294 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
6295 constants (if x has signed type, the sign bit cannot be set
6296 in c). This folds extension into the BIT_AND_EXPR. */
6297 if (INTEGRAL_TYPE_P (type)
6298 && TREE_CODE (type) != BOOLEAN_TYPE
6299 && TREE_CODE (TREE_OPERAND (t, 0)) == BIT_AND_EXPR
6300 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 1)) == INTEGER_CST)
6302 tree and = TREE_OPERAND (t, 0);
6303 tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
6306 if (TYPE_UNSIGNED (TREE_TYPE (and))
6307 || (TYPE_PRECISION (type)
6308 <= TYPE_PRECISION (TREE_TYPE (and))))
6310 else if (TYPE_PRECISION (TREE_TYPE (and1))
6311 <= HOST_BITS_PER_WIDE_INT
6312 && host_integerp (and1, 1))
6314 unsigned HOST_WIDE_INT cst;
6316 cst = tree_low_cst (and1, 1);
6317 cst &= (HOST_WIDE_INT) -1
6318 << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
6319 change = (cst == 0);
6320 #ifdef LOAD_EXTEND_OP
6322 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
6325 tree uns = lang_hooks.types.unsigned_type (TREE_TYPE (and0));
6326 and0 = fold_convert (uns, and0);
6327 and1 = fold_convert (uns, and1);
6332 return fold (build2 (BIT_AND_EXPR, type,
6333 fold_convert (type, and0),
6334 fold_convert (type, and1)));
6337 /* Convert (T1)((T2)X op Y) into (T1)X op Y, for pointer types T1 and
6338 T2 being pointers to types of the same size. */
6339 if (POINTER_TYPE_P (TREE_TYPE (t))
6340 && TREE_CODE_CLASS (TREE_CODE (arg0)) == '2'
6341 && TREE_CODE (TREE_OPERAND (arg0, 0)) == NOP_EXPR
6342 && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 0))))
6344 tree arg00 = TREE_OPERAND (arg0, 0);
6345 tree t0 = TREE_TYPE (t);
6346 tree t1 = TREE_TYPE (arg00);
6347 tree tt0 = TREE_TYPE (t0);
6348 tree tt1 = TREE_TYPE (t1);
6349 tree s0 = TYPE_SIZE (tt0);
6350 tree s1 = TYPE_SIZE (tt1);
6352 if (s0 && s1 && operand_equal_p (s0, s1, OEP_ONLY_CONST))
6353 return build2 (TREE_CODE (arg0), t0, fold_convert (t0, arg00),
6354 TREE_OPERAND (arg0, 1));
6357 tem = fold_convert_const (code, type, arg0);
6358 return tem ? tem : t;
6360 case VIEW_CONVERT_EXPR:
6361 if (TREE_CODE (TREE_OPERAND (t, 0)) == VIEW_CONVERT_EXPR)
6362 return build1 (VIEW_CONVERT_EXPR, type,
6363 TREE_OPERAND (TREE_OPERAND (t, 0), 0));
6367 if (TREE_CODE (arg0) == CONSTRUCTOR
6368 && ! type_contains_placeholder_p (TREE_TYPE (arg0)))
6370 tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0));
6372 return TREE_VALUE (m);
6377 if (TREE_CONSTANT (t) != wins)
6379 tem = copy_node (t);
6380 TREE_CONSTANT (tem) = wins;
6381 TREE_INVARIANT (tem) = wins;
6387 if (negate_expr_p (arg0))
6388 return fold_convert (type, negate_expr (arg0));
6392 if (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST)
6393 return fold_abs_const (arg0, type);
6394 else if (TREE_CODE (arg0) == NEGATE_EXPR)
6395 return fold (build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0)));
6396 /* Convert fabs((double)float) into (double)fabsf(float). */
6397 else if (TREE_CODE (arg0) == NOP_EXPR
6398 && TREE_CODE (type) == REAL_TYPE)
6400 tree targ0 = strip_float_extensions (arg0);
6402 return fold_convert (type, fold (build1 (ABS_EXPR,
6406 else if (tree_expr_nonnegative_p (arg0))
6411 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
6412 return fold_convert (type, arg0);
6413 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
6414 return build2 (COMPLEX_EXPR, type,
6415 TREE_OPERAND (arg0, 0),
6416 negate_expr (TREE_OPERAND (arg0, 1)));
6417 else if (TREE_CODE (arg0) == COMPLEX_CST)
6418 return build_complex (type, TREE_REALPART (arg0),
6419 negate_expr (TREE_IMAGPART (arg0)));
6420 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
6421 return fold (build2 (TREE_CODE (arg0), type,
6422 fold (build1 (CONJ_EXPR, type,
6423 TREE_OPERAND (arg0, 0))),
6424 fold (build1 (CONJ_EXPR, type,
6425 TREE_OPERAND (arg0, 1)))));
6426 else if (TREE_CODE (arg0) == CONJ_EXPR)
6427 return TREE_OPERAND (arg0, 0);
6431 if (TREE_CODE (arg0) == INTEGER_CST)
6432 return fold_not_const (arg0, type);
6433 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
6434 return TREE_OPERAND (arg0, 0);
6438 /* A + (-B) -> A - B */
6439 if (TREE_CODE (arg1) == NEGATE_EXPR)
6440 return fold (build2 (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
6441 /* (-A) + B -> B - A */
6442 if (TREE_CODE (arg0) == NEGATE_EXPR
6443 && reorder_operands_p (TREE_OPERAND (arg0, 0), arg1))
6444 return fold (build2 (MINUS_EXPR, type, arg1, TREE_OPERAND (arg0, 0)));
6445 if (! FLOAT_TYPE_P (type))
6447 if (integer_zerop (arg1))
6448 return non_lvalue (fold_convert (type, arg0));
6450 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
6451 with a constant, and the two constants have no bits in common,
6452 we should treat this as a BIT_IOR_EXPR since this may produce more
6454 if (TREE_CODE (arg0) == BIT_AND_EXPR
6455 && TREE_CODE (arg1) == BIT_AND_EXPR
6456 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6457 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
6458 && integer_zerop (const_binop (BIT_AND_EXPR,
6459 TREE_OPERAND (arg0, 1),
6460 TREE_OPERAND (arg1, 1), 0)))
6462 code = BIT_IOR_EXPR;
6466 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
6467 (plus (plus (mult) (mult)) (foo)) so that we can
6468 take advantage of the factoring cases below. */
6469 if ((TREE_CODE (arg0) == PLUS_EXPR
6470 && TREE_CODE (arg1) == MULT_EXPR)
6471 || (TREE_CODE (arg1) == PLUS_EXPR
6472 && TREE_CODE (arg0) == MULT_EXPR))
6474 tree parg0, parg1, parg, marg;
6476 if (TREE_CODE (arg0) == PLUS_EXPR)
6477 parg = arg0, marg = arg1;
6479 parg = arg1, marg = arg0;
6480 parg0 = TREE_OPERAND (parg, 0);
6481 parg1 = TREE_OPERAND (parg, 1);
6485 if (TREE_CODE (parg0) == MULT_EXPR
6486 && TREE_CODE (parg1) != MULT_EXPR)
6487 return fold (build2 (PLUS_EXPR, type,
6488 fold (build2 (PLUS_EXPR, type,
6489 fold_convert (type, parg0),
6490 fold_convert (type, marg))),
6491 fold_convert (type, parg1)));
6492 if (TREE_CODE (parg0) != MULT_EXPR
6493 && TREE_CODE (parg1) == MULT_EXPR)
6494 return fold (build2 (PLUS_EXPR, type,
6495 fold (build2 (PLUS_EXPR, type,
6496 fold_convert (type, parg1),
6497 fold_convert (type, marg))),
6498 fold_convert (type, parg0)));
6501 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR)
6503 tree arg00, arg01, arg10, arg11;
6504 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
6506 /* (A * C) + (B * C) -> (A+B) * C.
6507 We are most concerned about the case where C is a constant,
6508 but other combinations show up during loop reduction. Since
6509 it is not difficult, try all four possibilities. */
6511 arg00 = TREE_OPERAND (arg0, 0);
6512 arg01 = TREE_OPERAND (arg0, 1);
6513 arg10 = TREE_OPERAND (arg1, 0);
6514 arg11 = TREE_OPERAND (arg1, 1);
6517 if (operand_equal_p (arg01, arg11, 0))
6518 same = arg01, alt0 = arg00, alt1 = arg10;
6519 else if (operand_equal_p (arg00, arg10, 0))
6520 same = arg00, alt0 = arg01, alt1 = arg11;
6521 else if (operand_equal_p (arg00, arg11, 0))
6522 same = arg00, alt0 = arg01, alt1 = arg10;
6523 else if (operand_equal_p (arg01, arg10, 0))
6524 same = arg01, alt0 = arg00, alt1 = arg11;
6526 /* No identical multiplicands; see if we can find a common
6527 power-of-two factor in non-power-of-two multiplies. This
6528 can help in multi-dimensional array access. */
6529 else if (TREE_CODE (arg01) == INTEGER_CST
6530 && TREE_CODE (arg11) == INTEGER_CST
6531 && TREE_INT_CST_HIGH (arg01) == 0
6532 && TREE_INT_CST_HIGH (arg11) == 0)
6534 HOST_WIDE_INT int01, int11, tmp;
6535 int01 = TREE_INT_CST_LOW (arg01);
6536 int11 = TREE_INT_CST_LOW (arg11);
6538 /* Move min of absolute values to int11. */
6539 if ((int01 >= 0 ? int01 : -int01)
6540 < (int11 >= 0 ? int11 : -int11))
6542 tmp = int01, int01 = int11, int11 = tmp;
6543 alt0 = arg00, arg00 = arg10, arg10 = alt0;
6544 alt0 = arg01, arg01 = arg11, arg11 = alt0;
6547 if (exact_log2 (int11) > 0 && int01 % int11 == 0)
6549 alt0 = fold (build2 (MULT_EXPR, type, arg00,
6550 build_int_2 (int01 / int11, 0)));
6557 return fold (build2 (MULT_EXPR, type,
6558 fold (build2 (PLUS_EXPR, type,
6565 /* See if ARG1 is zero and X + ARG1 reduces to X. */
6566 if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
6567 return non_lvalue (fold_convert (type, arg0));
6569 /* Likewise if the operands are reversed. */
6570 if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
6571 return non_lvalue (fold_convert (type, arg1));
6573 /* Convert x+x into x*2.0. */
6574 if (operand_equal_p (arg0, arg1, 0)
6575 && SCALAR_FLOAT_TYPE_P (type))
6576 return fold (build2 (MULT_EXPR, type, arg0,
6577 build_real (type, dconst2)));
6579 /* Convert x*c+x into x*(c+1). */
6580 if (flag_unsafe_math_optimizations
6581 && TREE_CODE (arg0) == MULT_EXPR
6582 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
6583 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0, 1))
6584 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
6588 c = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
6589 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
6590 return fold (build2 (MULT_EXPR, type, arg1,
6591 build_real (type, c)));
6594 /* Convert x+x*c into x*(c+1). */
6595 if (flag_unsafe_math_optimizations
6596 && TREE_CODE (arg1) == MULT_EXPR
6597 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST
6598 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1, 1))
6599 && operand_equal_p (TREE_OPERAND (arg1, 0), arg0, 0))
6603 c = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
6604 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
6605 return fold (build2 (MULT_EXPR, type, arg0,
6606 build_real (type, c)));
6609 /* Convert x*c1+x*c2 into x*(c1+c2). */
6610 if (flag_unsafe_math_optimizations
6611 && TREE_CODE (arg0) == MULT_EXPR
6612 && TREE_CODE (arg1) == MULT_EXPR
6613 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
6614 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0, 1))
6615 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST
6616 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1, 1))
6617 && operand_equal_p (TREE_OPERAND (arg0, 0),
6618 TREE_OPERAND (arg1, 0), 0))
6620 REAL_VALUE_TYPE c1, c2;
6622 c1 = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
6623 c2 = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
6624 real_arithmetic (&c1, PLUS_EXPR, &c1, &c2);
6625 return fold (build2 (MULT_EXPR, type,
6626 TREE_OPERAND (arg0, 0),
6627 build_real (type, c1)));
6629 /* Convert a + (b*c + d*e) into (a + b*c) + d*e */
6630 if (flag_unsafe_math_optimizations
6631 && TREE_CODE (arg1) == PLUS_EXPR
6632 && TREE_CODE (arg0) != MULT_EXPR)
6634 tree tree10 = TREE_OPERAND (arg1, 0);
6635 tree tree11 = TREE_OPERAND (arg1, 1);
6636 if (TREE_CODE (tree11) == MULT_EXPR
6637 && TREE_CODE (tree10) == MULT_EXPR)
6640 tree0 = fold (build2 (PLUS_EXPR, type, arg0, tree10));
6641 return fold (build2 (PLUS_EXPR, type, tree0, tree11));
6644 /* Convert (b*c + d*e) + a into b*c + (d*e +a) */
6645 if (flag_unsafe_math_optimizations
6646 && TREE_CODE (arg0) == PLUS_EXPR
6647 && TREE_CODE (arg1) != MULT_EXPR)
6649 tree tree00 = TREE_OPERAND (arg0, 0);
6650 tree tree01 = TREE_OPERAND (arg0, 1);
6651 if (TREE_CODE (tree01) == MULT_EXPR
6652 && TREE_CODE (tree00) == MULT_EXPR)
6655 tree0 = fold (build2 (PLUS_EXPR, type, tree01, arg1));
6656 return fold (build2 (PLUS_EXPR, type, tree00, tree0));
6662 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
6663 is a rotate of A by C1 bits. */
6664 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
6665 is a rotate of A by B bits. */
6667 enum tree_code code0, code1;
6668 code0 = TREE_CODE (arg0);
6669 code1 = TREE_CODE (arg1);
6670 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
6671 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
6672 && operand_equal_p (TREE_OPERAND (arg0, 0),
6673 TREE_OPERAND (arg1, 0), 0)
6674 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
6676 tree tree01, tree11;
6677 enum tree_code code01, code11;
6679 tree01 = TREE_OPERAND (arg0, 1);
6680 tree11 = TREE_OPERAND (arg1, 1);
6681 STRIP_NOPS (tree01);
6682 STRIP_NOPS (tree11);
6683 code01 = TREE_CODE (tree01);
6684 code11 = TREE_CODE (tree11);
6685 if (code01 == INTEGER_CST
6686 && code11 == INTEGER_CST
6687 && TREE_INT_CST_HIGH (tree01) == 0
6688 && TREE_INT_CST_HIGH (tree11) == 0
6689 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
6690 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
6691 return build2 (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
6692 code0 == LSHIFT_EXPR ? tree01 : tree11);
6693 else if (code11 == MINUS_EXPR)
6695 tree tree110, tree111;
6696 tree110 = TREE_OPERAND (tree11, 0);
6697 tree111 = TREE_OPERAND (tree11, 1);
6698 STRIP_NOPS (tree110);
6699 STRIP_NOPS (tree111);
6700 if (TREE_CODE (tree110) == INTEGER_CST
6701 && 0 == compare_tree_int (tree110,
6703 (TREE_TYPE (TREE_OPERAND
6705 && operand_equal_p (tree01, tree111, 0))
6706 return build2 ((code0 == LSHIFT_EXPR
6709 type, TREE_OPERAND (arg0, 0), tree01);
6711 else if (code01 == MINUS_EXPR)
6713 tree tree010, tree011;
6714 tree010 = TREE_OPERAND (tree01, 0);
6715 tree011 = TREE_OPERAND (tree01, 1);
6716 STRIP_NOPS (tree010);
6717 STRIP_NOPS (tree011);
6718 if (TREE_CODE (tree010) == INTEGER_CST
6719 && 0 == compare_tree_int (tree010,
6721 (TREE_TYPE (TREE_OPERAND
6723 && operand_equal_p (tree11, tree011, 0))
6724 return build2 ((code0 != LSHIFT_EXPR
6727 type, TREE_OPERAND (arg0, 0), tree11);
6733 /* In most languages, can't associate operations on floats through
6734 parentheses. Rather than remember where the parentheses were, we
6735 don't associate floats at all, unless the user has specified
6736 -funsafe-math-optimizations. */
6739 && (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
6741 tree var0, con0, lit0, minus_lit0;
6742 tree var1, con1, lit1, minus_lit1;
6744 /* Split both trees into variables, constants, and literals. Then
6745 associate each group together, the constants with literals,
6746 then the result with variables. This increases the chances of
6747 literals being recombined later and of generating relocatable
6748 expressions for the sum of a constant and literal. */
6749 var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
6750 var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
6751 code == MINUS_EXPR);
6753 /* Only do something if we found more than two objects. Otherwise,
6754 nothing has changed and we risk infinite recursion. */
6755 if (2 < ((var0 != 0) + (var1 != 0)
6756 + (con0 != 0) + (con1 != 0)
6757 + (lit0 != 0) + (lit1 != 0)
6758 + (minus_lit0 != 0) + (minus_lit1 != 0)))
6760 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
6761 if (code == MINUS_EXPR)
6764 var0 = associate_trees (var0, var1, code, type);
6765 con0 = associate_trees (con0, con1, code, type);
6766 lit0 = associate_trees (lit0, lit1, code, type);
6767 minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
6769 /* Preserve the MINUS_EXPR if the negative part of the literal is
6770 greater than the positive part. Otherwise, the multiplicative
6771 folding code (i.e extract_muldiv) may be fooled in case
6772 unsigned constants are subtracted, like in the following
6773 example: ((X*2 + 4) - 8U)/2. */
6774 if (minus_lit0 && lit0)
6776 if (TREE_CODE (lit0) == INTEGER_CST
6777 && TREE_CODE (minus_lit0) == INTEGER_CST
6778 && tree_int_cst_lt (lit0, minus_lit0))
6780 minus_lit0 = associate_trees (minus_lit0, lit0,
6786 lit0 = associate_trees (lit0, minus_lit0,
6794 return fold_convert (type,
6795 associate_trees (var0, minus_lit0,
6799 con0 = associate_trees (con0, minus_lit0,
6801 return fold_convert (type,
6802 associate_trees (var0, con0,
6807 con0 = associate_trees (con0, lit0, code, type);
6808 return fold_convert (type, associate_trees (var0, con0,
6815 t1 = const_binop (code, arg0, arg1, 0);
6816 if (t1 != NULL_TREE)
6818 /* The return value should always have
6819 the same type as the original expression. */
6820 if (TREE_TYPE (t1) != type)
6821 t1 = fold_convert (type, t1);
6828 /* A - (-B) -> A + B */
6829 if (TREE_CODE (arg1) == NEGATE_EXPR)
6830 return fold (build2 (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
6831 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
6832 if (TREE_CODE (arg0) == NEGATE_EXPR
6833 && (FLOAT_TYPE_P (type)
6834 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv))
6835 && negate_expr_p (arg1)
6836 && reorder_operands_p (arg0, arg1))
6837 return fold (build2 (MINUS_EXPR, type, negate_expr (arg1),
6838 TREE_OPERAND (arg0, 0)));
6840 if (! FLOAT_TYPE_P (type))
6842 if (! wins && integer_zerop (arg0))
6843 return negate_expr (fold_convert (type, arg1));
6844 if (integer_zerop (arg1))
6845 return non_lvalue (fold_convert (type, arg0));
6847 /* Fold A - (A & B) into ~B & A. */
6848 if (!TREE_SIDE_EFFECTS (arg0)
6849 && TREE_CODE (arg1) == BIT_AND_EXPR)
6851 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
6852 return fold (build2 (BIT_AND_EXPR, type,
6853 fold (build1 (BIT_NOT_EXPR, type,
6854 TREE_OPERAND (arg1, 0))),
6856 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
6857 return fold (build2 (BIT_AND_EXPR, type,
6858 fold (build1 (BIT_NOT_EXPR, type,
6859 TREE_OPERAND (arg1, 1))),
6863 /* Fold (A & ~B) - (A & B) into (A ^ B) - B, where B is
6864 any power of 2 minus 1. */
6865 if (TREE_CODE (arg0) == BIT_AND_EXPR
6866 && TREE_CODE (arg1) == BIT_AND_EXPR
6867 && operand_equal_p (TREE_OPERAND (arg0, 0),
6868 TREE_OPERAND (arg1, 0), 0))
6870 tree mask0 = TREE_OPERAND (arg0, 1);
6871 tree mask1 = TREE_OPERAND (arg1, 1);
6872 tree tem = fold (build1 (BIT_NOT_EXPR, type, mask0));
6874 if (operand_equal_p (tem, mask1, 0))
6876 tem = fold (build2 (BIT_XOR_EXPR, type,
6877 TREE_OPERAND (arg0, 0), mask1));
6878 return fold (build2 (MINUS_EXPR, type, tem, mask1));
6883 /* See if ARG1 is zero and X - ARG1 reduces to X. */
6884 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
6885 return non_lvalue (fold_convert (type, arg0));
6887 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
6888 ARG0 is zero and X + ARG0 reduces to X, since that would mean
6889 (-ARG1 + ARG0) reduces to -ARG1. */
6890 else if (!wins && fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
6891 return negate_expr (fold_convert (type, arg1));
6893 /* Fold &x - &x. This can happen from &x.foo - &x.
6894 This is unsafe for certain floats even in non-IEEE formats.
6895 In IEEE, it is unsafe because it does wrong for NaNs.
6896 Also note that operand_equal_p is always false if an operand
6899 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
6900 && operand_equal_p (arg0, arg1, 0))
6901 return fold_convert (type, integer_zero_node);
6903 /* A - B -> A + (-B) if B is easily negatable. */
6904 if (!wins && negate_expr_p (arg1)
6905 && (FLOAT_TYPE_P (type)
6906 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv)))
6907 return fold (build2 (PLUS_EXPR, type, arg0, negate_expr (arg1)));
6909 if (TREE_CODE (arg0) == MULT_EXPR
6910 && TREE_CODE (arg1) == MULT_EXPR
6911 && (INTEGRAL_TYPE_P (type) || flag_unsafe_math_optimizations))
6913 /* (A * C) - (B * C) -> (A-B) * C. */
6914 if (operand_equal_p (TREE_OPERAND (arg0, 1),
6915 TREE_OPERAND (arg1, 1), 0))
6916 return fold (build2 (MULT_EXPR, type,
6917 fold (build2 (MINUS_EXPR, type,
6918 TREE_OPERAND (arg0, 0),
6919 TREE_OPERAND (arg1, 0))),
6920 TREE_OPERAND (arg0, 1)));
6921 /* (A * C1) - (A * C2) -> A * (C1-C2). */
6922 if (operand_equal_p (TREE_OPERAND (arg0, 0),
6923 TREE_OPERAND (arg1, 0), 0))
6924 return fold (build2 (MULT_EXPR, type,
6925 TREE_OPERAND (arg0, 0),
6926 fold (build2 (MINUS_EXPR, type,
6927 TREE_OPERAND (arg0, 1),
6928 TREE_OPERAND (arg1, 1)))));
6934 /* (-A) * (-B) -> A * B */
6935 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
6936 return fold (build2 (MULT_EXPR, type,
6937 TREE_OPERAND (arg0, 0),
6938 negate_expr (arg1)));
6939 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
6940 return fold (build2 (MULT_EXPR, type,
6942 TREE_OPERAND (arg1, 0)));
6944 if (! FLOAT_TYPE_P (type))
6946 if (integer_zerop (arg1))
6947 return omit_one_operand (type, arg1, arg0);
6948 if (integer_onep (arg1))
6949 return non_lvalue (fold_convert (type, arg0));
6951 /* (a * (1 << b)) is (a << b) */
6952 if (TREE_CODE (arg1) == LSHIFT_EXPR
6953 && integer_onep (TREE_OPERAND (arg1, 0)))
6954 return fold (build2 (LSHIFT_EXPR, type, arg0,
6955 TREE_OPERAND (arg1, 1)));
6956 if (TREE_CODE (arg0) == LSHIFT_EXPR
6957 && integer_onep (TREE_OPERAND (arg0, 0)))
6958 return fold (build2 (LSHIFT_EXPR, type, arg1,
6959 TREE_OPERAND (arg0, 1)));
6961 if (TREE_CODE (arg1) == INTEGER_CST
6962 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0),
6963 fold_convert (type, arg1),
6965 return fold_convert (type, tem);
6970 /* Maybe fold x * 0 to 0. The expressions aren't the same
6971 when x is NaN, since x * 0 is also NaN. Nor are they the
6972 same in modes with signed zeros, since multiplying a
6973 negative value by 0 gives -0, not +0. */
6974 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
6975 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
6976 && real_zerop (arg1))
6977 return omit_one_operand (type, arg1, arg0);
6978 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
6979 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
6980 && real_onep (arg1))
6981 return non_lvalue (fold_convert (type, arg0));
6983 /* Transform x * -1.0 into -x. */
6984 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
6985 && real_minus_onep (arg1))
6986 return fold_convert (type, negate_expr (arg0));
6988 /* Convert (C1/X)*C2 into (C1*C2)/X. */
6989 if (flag_unsafe_math_optimizations
6990 && TREE_CODE (arg0) == RDIV_EXPR
6991 && TREE_CODE (arg1) == REAL_CST
6992 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST)
6994 tree tem = const_binop (MULT_EXPR, TREE_OPERAND (arg0, 0),
6997 return fold (build2 (RDIV_EXPR, type, tem,
6998 TREE_OPERAND (arg0, 1)));
7001 if (flag_unsafe_math_optimizations)
7003 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
7004 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
7006 /* Optimizations of root(...)*root(...). */
7007 if (fcode0 == fcode1 && BUILTIN_ROOT_P (fcode0))
7009 tree rootfn, arg, arglist;
7010 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
7011 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
7013 /* Optimize sqrt(x)*sqrt(x) as x. */
7014 if (BUILTIN_SQRT_P (fcode0)
7015 && operand_equal_p (arg00, arg10, 0)
7016 && ! HONOR_SNANS (TYPE_MODE (type)))
7019 /* Optimize root(x)*root(y) as root(x*y). */
7020 rootfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7021 arg = fold (build2 (MULT_EXPR, type, arg00, arg10));
7022 arglist = build_tree_list (NULL_TREE, arg);
7023 return build_function_call_expr (rootfn, arglist);
7026 /* Optimize expN(x)*expN(y) as expN(x+y). */
7027 if (fcode0 == fcode1 && BUILTIN_EXPONENT_P (fcode0))
7029 tree expfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7030 tree arg = build2 (PLUS_EXPR, type,
7031 TREE_VALUE (TREE_OPERAND (arg0, 1)),
7032 TREE_VALUE (TREE_OPERAND (arg1, 1)));
7033 tree arglist = build_tree_list (NULL_TREE, fold (arg));
7034 return build_function_call_expr (expfn, arglist);
7037 /* Optimizations of pow(...)*pow(...). */
7038 if ((fcode0 == BUILT_IN_POW && fcode1 == BUILT_IN_POW)
7039 || (fcode0 == BUILT_IN_POWF && fcode1 == BUILT_IN_POWF)
7040 || (fcode0 == BUILT_IN_POWL && fcode1 == BUILT_IN_POWL))
7042 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
7043 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
7045 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
7046 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
7049 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
7050 if (operand_equal_p (arg01, arg11, 0))
7052 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7053 tree arg = build2 (MULT_EXPR, type, arg00, arg10);
7054 tree arglist = tree_cons (NULL_TREE, fold (arg),
7055 build_tree_list (NULL_TREE,
7057 return build_function_call_expr (powfn, arglist);
7060 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
7061 if (operand_equal_p (arg00, arg10, 0))
7063 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7064 tree arg = fold (build2 (PLUS_EXPR, type, arg01, arg11));
7065 tree arglist = tree_cons (NULL_TREE, arg00,
7066 build_tree_list (NULL_TREE,
7068 return build_function_call_expr (powfn, arglist);
7072 /* Optimize tan(x)*cos(x) as sin(x). */
7073 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_COS)
7074 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_COSF)
7075 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_COSL)
7076 || (fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_TAN)
7077 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_TANF)
7078 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_TANL))
7079 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
7080 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
7082 tree sinfn = mathfn_built_in (type, BUILT_IN_SIN);
7084 if (sinfn != NULL_TREE)
7085 return build_function_call_expr (sinfn,
7086 TREE_OPERAND (arg0, 1));
7089 /* Optimize x*pow(x,c) as pow(x,c+1). */
7090 if (fcode1 == BUILT_IN_POW
7091 || fcode1 == BUILT_IN_POWF
7092 || fcode1 == BUILT_IN_POWL)
7094 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
7095 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
7097 if (TREE_CODE (arg11) == REAL_CST
7098 && ! TREE_CONSTANT_OVERFLOW (arg11)
7099 && operand_equal_p (arg0, arg10, 0))
7101 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
7105 c = TREE_REAL_CST (arg11);
7106 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
7107 arg = build_real (type, c);
7108 arglist = build_tree_list (NULL_TREE, arg);
7109 arglist = tree_cons (NULL_TREE, arg0, arglist);
7110 return build_function_call_expr (powfn, arglist);
7114 /* Optimize pow(x,c)*x as pow(x,c+1). */
7115 if (fcode0 == BUILT_IN_POW
7116 || fcode0 == BUILT_IN_POWF
7117 || fcode0 == BUILT_IN_POWL)
7119 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
7120 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
7122 if (TREE_CODE (arg01) == REAL_CST
7123 && ! TREE_CONSTANT_OVERFLOW (arg01)
7124 && operand_equal_p (arg1, arg00, 0))
7126 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7130 c = TREE_REAL_CST (arg01);
7131 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
7132 arg = build_real (type, c);
7133 arglist = build_tree_list (NULL_TREE, arg);
7134 arglist = tree_cons (NULL_TREE, arg1, arglist);
7135 return build_function_call_expr (powfn, arglist);
7139 /* Optimize x*x as pow(x,2.0), which is expanded as x*x. */
7141 && operand_equal_p (arg0, arg1, 0))
7143 tree powfn = mathfn_built_in (type, BUILT_IN_POW);
7147 tree arg = build_real (type, dconst2);
7148 tree arglist = build_tree_list (NULL_TREE, arg);
7149 arglist = tree_cons (NULL_TREE, arg0, arglist);
7150 return build_function_call_expr (powfn, arglist);
7159 if (integer_all_onesp (arg1))
7160 return omit_one_operand (type, arg1, arg0);
7161 if (integer_zerop (arg1))
7162 return non_lvalue (fold_convert (type, arg0));
7163 if (operand_equal_p (arg0, arg1, 0))
7164 return non_lvalue (fold_convert (type, arg0));
7165 t1 = distribute_bit_expr (code, type, arg0, arg1);
7166 if (t1 != NULL_TREE)
7169 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
7171 This results in more efficient code for machines without a NAND
7172 instruction. Combine will canonicalize to the first form
7173 which will allow use of NAND instructions provided by the
7174 backend if they exist. */
7175 if (TREE_CODE (arg0) == BIT_NOT_EXPR
7176 && TREE_CODE (arg1) == BIT_NOT_EXPR)
7178 return fold (build1 (BIT_NOT_EXPR, type,
7179 build2 (BIT_AND_EXPR, type,
7180 TREE_OPERAND (arg0, 0),
7181 TREE_OPERAND (arg1, 0))));
7184 /* See if this can be simplified into a rotate first. If that
7185 is unsuccessful continue in the association code. */
7189 if (integer_zerop (arg1))
7190 return non_lvalue (fold_convert (type, arg0));
7191 if (integer_all_onesp (arg1))
7192 return fold (build1 (BIT_NOT_EXPR, type, arg0));
7193 if (operand_equal_p (arg0, arg1, 0))
7194 return omit_one_operand (type, integer_zero_node, arg0);
7196 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
7197 with a constant, and the two constants have no bits in common,
7198 we should treat this as a BIT_IOR_EXPR since this may produce more
7200 if (TREE_CODE (arg0) == BIT_AND_EXPR
7201 && TREE_CODE (arg1) == BIT_AND_EXPR
7202 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7203 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
7204 && integer_zerop (const_binop (BIT_AND_EXPR,
7205 TREE_OPERAND (arg0, 1),
7206 TREE_OPERAND (arg1, 1), 0)))
7208 code = BIT_IOR_EXPR;
7212 /* See if this can be simplified into a rotate first. If that
7213 is unsuccessful continue in the association code. */
7217 if (integer_all_onesp (arg1))
7218 return non_lvalue (fold_convert (type, arg0));
7219 if (integer_zerop (arg1))
7220 return omit_one_operand (type, arg1, arg0);
7221 if (operand_equal_p (arg0, arg1, 0))
7222 return non_lvalue (fold_convert (type, arg0));
7223 t1 = distribute_bit_expr (code, type, arg0, arg1);
7224 if (t1 != NULL_TREE)
7226 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
7227 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
7228 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
7231 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
7233 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
7234 && (~TREE_INT_CST_LOW (arg1)
7235 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
7236 return fold_convert (type, TREE_OPERAND (arg0, 0));
7239 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
7241 This results in more efficient code for machines without a NOR
7242 instruction. Combine will canonicalize to the first form
7243 which will allow use of NOR instructions provided by the
7244 backend if they exist. */
7245 if (TREE_CODE (arg0) == BIT_NOT_EXPR
7246 && TREE_CODE (arg1) == BIT_NOT_EXPR)
7248 return fold (build1 (BIT_NOT_EXPR, type,
7249 build2 (BIT_IOR_EXPR, type,
7250 TREE_OPERAND (arg0, 0),
7251 TREE_OPERAND (arg1, 0))));
7257 /* Don't touch a floating-point divide by zero unless the mode
7258 of the constant can represent infinity. */
7259 if (TREE_CODE (arg1) == REAL_CST
7260 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
7261 && real_zerop (arg1))
7264 /* (-A) / (-B) -> A / B */
7265 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
7266 return fold (build2 (RDIV_EXPR, type,
7267 TREE_OPERAND (arg0, 0),
7268 negate_expr (arg1)));
7269 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
7270 return fold (build2 (RDIV_EXPR, type,
7272 TREE_OPERAND (arg1, 0)));
7274 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
7275 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
7276 && real_onep (arg1))
7277 return non_lvalue (fold_convert (type, arg0));
7279 /* In IEEE floating point, x/-1 is not equivalent to -x for snans. */
7280 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
7281 && real_minus_onep (arg1))
7282 return non_lvalue (fold_convert (type, negate_expr (arg0)));
7284 /* If ARG1 is a constant, we can convert this to a multiply by the
7285 reciprocal. This does not have the same rounding properties,
7286 so only do this if -funsafe-math-optimizations. We can actually
7287 always safely do it if ARG1 is a power of two, but it's hard to
7288 tell if it is or not in a portable manner. */
7289 if (TREE_CODE (arg1) == REAL_CST)
7291 if (flag_unsafe_math_optimizations
7292 && 0 != (tem = const_binop (code, build_real (type, dconst1),
7294 return fold (build2 (MULT_EXPR, type, arg0, tem));
7295 /* Find the reciprocal if optimizing and the result is exact. */
7299 r = TREE_REAL_CST (arg1);
7300 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
7302 tem = build_real (type, r);
7303 return fold (build2 (MULT_EXPR, type, arg0, tem));
7307 /* Convert A/B/C to A/(B*C). */
7308 if (flag_unsafe_math_optimizations
7309 && TREE_CODE (arg0) == RDIV_EXPR)
7310 return fold (build2 (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
7311 fold (build2 (MULT_EXPR, type,
7312 TREE_OPERAND (arg0, 1), arg1))));
7314 /* Convert A/(B/C) to (A/B)*C. */
7315 if (flag_unsafe_math_optimizations
7316 && TREE_CODE (arg1) == RDIV_EXPR)
7317 return fold (build2 (MULT_EXPR, type,
7318 fold (build2 (RDIV_EXPR, type, arg0,
7319 TREE_OPERAND (arg1, 0))),
7320 TREE_OPERAND (arg1, 1)));
7322 /* Convert C1/(X*C2) into (C1/C2)/X. */
7323 if (flag_unsafe_math_optimizations
7324 && TREE_CODE (arg1) == MULT_EXPR
7325 && TREE_CODE (arg0) == REAL_CST
7326 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
7328 tree tem = const_binop (RDIV_EXPR, arg0,
7329 TREE_OPERAND (arg1, 1), 0);
7331 return fold (build2 (RDIV_EXPR, type, tem,
7332 TREE_OPERAND (arg1, 0)));
7335 if (flag_unsafe_math_optimizations)
7337 enum built_in_function fcode = builtin_mathfn_code (arg1);
7338 /* Optimize x/expN(y) into x*expN(-y). */
7339 if (BUILTIN_EXPONENT_P (fcode))
7341 tree expfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
7342 tree arg = negate_expr (TREE_VALUE (TREE_OPERAND (arg1, 1)));
7343 tree arglist = build_tree_list (NULL_TREE,
7344 fold_convert (type, arg));
7345 arg1 = build_function_call_expr (expfn, arglist);
7346 return fold (build2 (MULT_EXPR, type, arg0, arg1));
7349 /* Optimize x/pow(y,z) into x*pow(y,-z). */
7350 if (fcode == BUILT_IN_POW
7351 || fcode == BUILT_IN_POWF
7352 || fcode == BUILT_IN_POWL)
7354 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
7355 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
7356 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1, 1)));
7357 tree neg11 = fold_convert (type, negate_expr (arg11));
7358 tree arglist = tree_cons(NULL_TREE, arg10,
7359 build_tree_list (NULL_TREE, neg11));
7360 arg1 = build_function_call_expr (powfn, arglist);
7361 return fold (build2 (MULT_EXPR, type, arg0, arg1));
7365 if (flag_unsafe_math_optimizations)
7367 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
7368 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
7370 /* Optimize sin(x)/cos(x) as tan(x). */
7371 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_COS)
7372 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_COSF)
7373 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_COSL))
7374 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
7375 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
7377 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
7379 if (tanfn != NULL_TREE)
7380 return build_function_call_expr (tanfn,
7381 TREE_OPERAND (arg0, 1));
7384 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
7385 if (((fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_SIN)
7386 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_SINF)
7387 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_SINL))
7388 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
7389 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
7391 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
7393 if (tanfn != NULL_TREE)
7395 tree tmp = TREE_OPERAND (arg0, 1);
7396 tmp = build_function_call_expr (tanfn, tmp);
7397 return fold (build2 (RDIV_EXPR, type,
7398 build_real (type, dconst1), tmp));
7402 /* Optimize pow(x,c)/x as pow(x,c-1). */
7403 if (fcode0 == BUILT_IN_POW
7404 || fcode0 == BUILT_IN_POWF
7405 || fcode0 == BUILT_IN_POWL)
7407 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
7408 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0, 1)));
7409 if (TREE_CODE (arg01) == REAL_CST
7410 && ! TREE_CONSTANT_OVERFLOW (arg01)
7411 && operand_equal_p (arg1, arg00, 0))
7413 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7417 c = TREE_REAL_CST (arg01);
7418 real_arithmetic (&c, MINUS_EXPR, &c, &dconst1);
7419 arg = build_real (type, c);
7420 arglist = build_tree_list (NULL_TREE, arg);
7421 arglist = tree_cons (NULL_TREE, arg1, arglist);
7422 return build_function_call_expr (powfn, arglist);
7428 case TRUNC_DIV_EXPR:
7429 case ROUND_DIV_EXPR:
7430 case FLOOR_DIV_EXPR:
7432 case EXACT_DIV_EXPR:
7433 if (integer_onep (arg1))
7434 return non_lvalue (fold_convert (type, arg0));
7435 if (integer_zerop (arg1))
7438 if (!TYPE_UNSIGNED (type)
7439 && TREE_CODE (arg1) == INTEGER_CST
7440 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
7441 && TREE_INT_CST_HIGH (arg1) == -1)
7442 return fold_convert (type, negate_expr (arg0));
7444 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
7445 operation, EXACT_DIV_EXPR.
7447 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
7448 At one time others generated faster code, it's not clear if they do
7449 after the last round to changes to the DIV code in expmed.c. */
7450 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
7451 && multiple_of_p (type, arg0, arg1))
7452 return fold (build2 (EXACT_DIV_EXPR, type, arg0, arg1));
7454 if (TREE_CODE (arg1) == INTEGER_CST
7455 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
7457 return fold_convert (type, tem);
7462 case FLOOR_MOD_EXPR:
7463 case ROUND_MOD_EXPR:
7464 case TRUNC_MOD_EXPR:
7465 if (integer_onep (arg1))
7466 return omit_one_operand (type, integer_zero_node, arg0);
7467 if (integer_zerop (arg1))
7469 /* X % -1 is zero. */
7470 if (!TYPE_UNSIGNED (type)
7471 && TREE_CODE (arg1) == INTEGER_CST
7472 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
7473 && TREE_INT_CST_HIGH (arg1) == -1)
7474 return omit_one_operand (type, integer_zero_node, arg0);
7476 if (TREE_CODE (arg1) == INTEGER_CST
7477 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
7479 return fold_convert (type, tem);
7485 if (integer_all_onesp (arg0))
7486 return omit_one_operand (type, arg0, arg1);
7490 /* Optimize -1 >> x for arithmetic right shifts. */
7491 if (integer_all_onesp (arg0) && !TYPE_UNSIGNED (type))
7492 return omit_one_operand (type, arg0, arg1);
7493 /* ... fall through ... */
7497 if (integer_zerop (arg1))
7498 return non_lvalue (fold_convert (type, arg0));
7499 if (integer_zerop (arg0))
7500 return omit_one_operand (type, arg0, arg1);
7502 /* Since negative shift count is not well-defined,
7503 don't try to compute it in the compiler. */
7504 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
7506 /* Rewrite an LROTATE_EXPR by a constant into an
7507 RROTATE_EXPR by a new constant. */
7508 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
7510 tree tem = build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type)), 0);
7511 tem = fold_convert (TREE_TYPE (arg1), tem);
7512 tem = const_binop (MINUS_EXPR, tem, arg1, 0);
7513 return fold (build2 (RROTATE_EXPR, type, arg0, tem));
7516 /* If we have a rotate of a bit operation with the rotate count and
7517 the second operand of the bit operation both constant,
7518 permute the two operations. */
7519 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
7520 && (TREE_CODE (arg0) == BIT_AND_EXPR
7521 || TREE_CODE (arg0) == BIT_IOR_EXPR
7522 || TREE_CODE (arg0) == BIT_XOR_EXPR)
7523 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
7524 return fold (build2 (TREE_CODE (arg0), type,
7525 fold (build2 (code, type,
7526 TREE_OPERAND (arg0, 0), arg1)),
7527 fold (build2 (code, type,
7528 TREE_OPERAND (arg0, 1), arg1))));
7530 /* Two consecutive rotates adding up to the width of the mode can
7532 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
7533 && TREE_CODE (arg0) == RROTATE_EXPR
7534 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7535 && TREE_INT_CST_HIGH (arg1) == 0
7536 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
7537 && ((TREE_INT_CST_LOW (arg1)
7538 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
7539 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type))))
7540 return TREE_OPERAND (arg0, 0);
7545 if (operand_equal_p (arg0, arg1, 0))
7546 return omit_one_operand (type, arg0, arg1);
7547 if (INTEGRAL_TYPE_P (type)
7548 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
7549 return omit_one_operand (type, arg1, arg0);
7553 if (operand_equal_p (arg0, arg1, 0))
7554 return omit_one_operand (type, arg0, arg1);
7555 if (INTEGRAL_TYPE_P (type)
7556 && TYPE_MAX_VALUE (type)
7557 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
7558 return omit_one_operand (type, arg1, arg0);
7561 case TRUTH_NOT_EXPR:
7562 /* The argument to invert_truthvalue must have Boolean type. */
7563 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
7564 arg0 = fold_convert (boolean_type_node, arg0);
7566 /* Note that the operand of this must be an int
7567 and its values must be 0 or 1.
7568 ("true" is a fixed value perhaps depending on the language,
7569 but we don't handle values other than 1 correctly yet.) */
7570 tem = invert_truthvalue (arg0);
7571 /* Avoid infinite recursion. */
7572 if (TREE_CODE (tem) == TRUTH_NOT_EXPR)
7574 tem = fold_single_bit_test (code, arg0, arg1, type);
7579 return fold_convert (type, tem);
7581 case TRUTH_ANDIF_EXPR:
7582 /* Note that the operands of this must be ints
7583 and their values must be 0 or 1.
7584 ("true" is a fixed value perhaps depending on the language.) */
7585 /* If first arg is constant zero, return it. */
7586 if (integer_zerop (arg0))
7587 return fold_convert (type, arg0);
7588 case TRUTH_AND_EXPR:
7589 /* If either arg is constant true, drop it. */
7590 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
7591 return non_lvalue (fold_convert (type, arg1));
7592 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
7593 /* Preserve sequence points. */
7594 && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
7595 return non_lvalue (fold_convert (type, arg0));
7596 /* If second arg is constant zero, result is zero, but first arg
7597 must be evaluated. */
7598 if (integer_zerop (arg1))
7599 return omit_one_operand (type, arg1, arg0);
7600 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
7601 case will be handled here. */
7602 if (integer_zerop (arg0))
7603 return omit_one_operand (type, arg0, arg1);
7606 /* We only do these simplifications if we are optimizing. */
7610 /* Check for things like (A || B) && (A || C). We can convert this
7611 to A || (B && C). Note that either operator can be any of the four
7612 truth and/or operations and the transformation will still be
7613 valid. Also note that we only care about order for the
7614 ANDIF and ORIF operators. If B contains side effects, this
7615 might change the truth-value of A. */
7616 if (TREE_CODE (arg0) == TREE_CODE (arg1)
7617 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
7618 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
7619 || TREE_CODE (arg0) == TRUTH_AND_EXPR
7620 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
7621 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
7623 tree a00 = TREE_OPERAND (arg0, 0);
7624 tree a01 = TREE_OPERAND (arg0, 1);
7625 tree a10 = TREE_OPERAND (arg1, 0);
7626 tree a11 = TREE_OPERAND (arg1, 1);
7627 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
7628 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
7629 && (code == TRUTH_AND_EXPR
7630 || code == TRUTH_OR_EXPR));
7632 if (operand_equal_p (a00, a10, 0))
7633 return fold (build2 (TREE_CODE (arg0), type, a00,
7634 fold (build2 (code, type, a01, a11))));
7635 else if (commutative && operand_equal_p (a00, a11, 0))
7636 return fold (build2 (TREE_CODE (arg0), type, a00,
7637 fold (build2 (code, type, a01, a10))));
7638 else if (commutative && operand_equal_p (a01, a10, 0))
7639 return fold (build2 (TREE_CODE (arg0), type, a01,
7640 fold (build2 (code, type, a00, a11))));
7642 /* This case if tricky because we must either have commutative
7643 operators or else A10 must not have side-effects. */
7645 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
7646 && operand_equal_p (a01, a11, 0))
7647 return fold (build2 (TREE_CODE (arg0), type,
7648 fold (build2 (code, type, a00, a10)),
7652 /* See if we can build a range comparison. */
7653 if (0 != (tem = fold_range_test (t)))
7656 /* Check for the possibility of merging component references. If our
7657 lhs is another similar operation, try to merge its rhs with our
7658 rhs. Then try to merge our lhs and rhs. */
7659 if (TREE_CODE (arg0) == code
7660 && 0 != (tem = fold_truthop (code, type,
7661 TREE_OPERAND (arg0, 1), arg1)))
7662 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), tem));
7664 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
7669 case TRUTH_ORIF_EXPR:
7670 /* Note that the operands of this must be ints
7671 and their values must be 0 or true.
7672 ("true" is a fixed value perhaps depending on the language.) */
7673 /* If first arg is constant true, return it. */
7674 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
7675 return fold_convert (type, arg0);
7677 /* If either arg is constant zero, drop it. */
7678 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
7679 return non_lvalue (fold_convert (type, arg1));
7680 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
7681 /* Preserve sequence points. */
7682 && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
7683 return non_lvalue (fold_convert (type, arg0));
7684 /* If second arg is constant true, result is true, but we must
7685 evaluate first arg. */
7686 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
7687 return omit_one_operand (type, arg1, arg0);
7688 /* Likewise for first arg, but note this only occurs here for
7690 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
7691 return omit_one_operand (type, arg0, arg1);
7694 case TRUTH_XOR_EXPR:
7695 /* If either arg is constant zero, drop it. */
7696 if (integer_zerop (arg0))
7697 return non_lvalue (fold_convert (type, arg1));
7698 if (integer_zerop (arg1))
7699 return non_lvalue (fold_convert (type, arg0));
7700 /* If either arg is constant true, this is a logical inversion. */
7701 if (integer_onep (arg0))
7702 return non_lvalue (fold_convert (type, invert_truthvalue (arg1)));
7703 if (integer_onep (arg1))
7704 return non_lvalue (fold_convert (type, invert_truthvalue (arg0)));
7705 /* Identical arguments cancel to zero. */
7706 if (operand_equal_p (arg0, arg1, 0))
7707 return omit_one_operand (type, integer_zero_node, arg0);
7716 /* If one arg is a real or integer constant, put it last. */
7717 if (tree_swap_operands_p (arg0, arg1, true))
7718 return fold (build2 (swap_tree_comparison (code), type, arg1, arg0));
7720 /* If this is an equality comparison of the address of a non-weak
7721 object against zero, then we know the result. */
7722 if ((code == EQ_EXPR || code == NE_EXPR)
7723 && TREE_CODE (arg0) == ADDR_EXPR
7724 && DECL_P (TREE_OPERAND (arg0, 0))
7725 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
7726 && integer_zerop (arg1))
7727 return constant_boolean_node (code != EQ_EXPR, type);
7729 /* If this is an equality comparison of the address of two non-weak,
7730 unaliased symbols neither of which are extern (since we do not
7731 have access to attributes for externs), then we know the result. */
7732 if ((code == EQ_EXPR || code == NE_EXPR)
7733 && TREE_CODE (arg0) == ADDR_EXPR
7734 && DECL_P (TREE_OPERAND (arg0, 0))
7735 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
7736 && ! lookup_attribute ("alias",
7737 DECL_ATTRIBUTES (TREE_OPERAND (arg0, 0)))
7738 && ! DECL_EXTERNAL (TREE_OPERAND (arg0, 0))
7739 && TREE_CODE (arg1) == ADDR_EXPR
7740 && DECL_P (TREE_OPERAND (arg1, 0))
7741 && ! DECL_WEAK (TREE_OPERAND (arg1, 0))
7742 && ! lookup_attribute ("alias",
7743 DECL_ATTRIBUTES (TREE_OPERAND (arg1, 0)))
7744 && ! DECL_EXTERNAL (TREE_OPERAND (arg1, 0)))
7745 return constant_boolean_node (operand_equal_p (arg0, arg1, 0)
7746 ? code == EQ_EXPR : code != EQ_EXPR,
7749 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
7751 tree targ0 = strip_float_extensions (arg0);
7752 tree targ1 = strip_float_extensions (arg1);
7753 tree newtype = TREE_TYPE (targ0);
7755 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
7756 newtype = TREE_TYPE (targ1);
7758 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
7759 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
7760 return fold (build2 (code, type, fold_convert (newtype, targ0),
7761 fold_convert (newtype, targ1)));
7763 /* (-a) CMP (-b) -> b CMP a */
7764 if (TREE_CODE (arg0) == NEGATE_EXPR
7765 && TREE_CODE (arg1) == NEGATE_EXPR)
7766 return fold (build2 (code, type, TREE_OPERAND (arg1, 0),
7767 TREE_OPERAND (arg0, 0)));
7769 if (TREE_CODE (arg1) == REAL_CST)
7771 REAL_VALUE_TYPE cst;
7772 cst = TREE_REAL_CST (arg1);
7774 /* (-a) CMP CST -> a swap(CMP) (-CST) */
7775 if (TREE_CODE (arg0) == NEGATE_EXPR)
7777 fold (build2 (swap_tree_comparison (code), type,
7778 TREE_OPERAND (arg0, 0),
7779 build_real (TREE_TYPE (arg1),
7780 REAL_VALUE_NEGATE (cst))));
7782 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
7783 /* a CMP (-0) -> a CMP 0 */
7784 if (REAL_VALUE_MINUS_ZERO (cst))
7785 return fold (build2 (code, type, arg0,
7786 build_real (TREE_TYPE (arg1), dconst0)));
7788 /* x != NaN is always true, other ops are always false. */
7789 if (REAL_VALUE_ISNAN (cst)
7790 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))))
7792 tem = (code == NE_EXPR) ? integer_one_node : integer_zero_node;
7793 return omit_one_operand (type, tem, arg0);
7796 /* Fold comparisons against infinity. */
7797 if (REAL_VALUE_ISINF (cst))
7799 tem = fold_inf_compare (code, type, arg0, arg1);
7800 if (tem != NULL_TREE)
7805 /* If this is a comparison of a real constant with a PLUS_EXPR
7806 or a MINUS_EXPR of a real constant, we can convert it into a
7807 comparison with a revised real constant as long as no overflow
7808 occurs when unsafe_math_optimizations are enabled. */
7809 if (flag_unsafe_math_optimizations
7810 && TREE_CODE (arg1) == REAL_CST
7811 && (TREE_CODE (arg0) == PLUS_EXPR
7812 || TREE_CODE (arg0) == MINUS_EXPR)
7813 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
7814 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
7815 ? MINUS_EXPR : PLUS_EXPR,
7816 arg1, TREE_OPERAND (arg0, 1), 0))
7817 && ! TREE_CONSTANT_OVERFLOW (tem))
7818 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), tem));
7820 /* Likewise, we can simplify a comparison of a real constant with
7821 a MINUS_EXPR whose first operand is also a real constant, i.e.
7822 (c1 - x) < c2 becomes x > c1-c2. */
7823 if (flag_unsafe_math_optimizations
7824 && TREE_CODE (arg1) == REAL_CST
7825 && TREE_CODE (arg0) == MINUS_EXPR
7826 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST
7827 && 0 != (tem = const_binop (MINUS_EXPR, TREE_OPERAND (arg0, 0),
7829 && ! TREE_CONSTANT_OVERFLOW (tem))
7830 return fold (build2 (swap_tree_comparison (code), type,
7831 TREE_OPERAND (arg0, 1), tem));
7833 /* Fold comparisons against built-in math functions. */
7834 if (TREE_CODE (arg1) == REAL_CST
7835 && flag_unsafe_math_optimizations
7836 && ! flag_errno_math)
7838 enum built_in_function fcode = builtin_mathfn_code (arg0);
7840 if (fcode != END_BUILTINS)
7842 tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
7843 if (tem != NULL_TREE)
7849 /* Convert foo++ == CONST into ++foo == CONST + INCR. */
7850 if (TREE_CONSTANT (arg1)
7851 && (TREE_CODE (arg0) == POSTINCREMENT_EXPR
7852 || TREE_CODE (arg0) == POSTDECREMENT_EXPR)
7853 /* This optimization is invalid for ordered comparisons
7854 if CONST+INCR overflows or if foo+incr might overflow.
7855 This optimization is invalid for floating point due to rounding.
7856 For pointer types we assume overflow doesn't happen. */
7857 && (POINTER_TYPE_P (TREE_TYPE (arg0))
7858 || (INTEGRAL_TYPE_P (TREE_TYPE (arg0))
7859 && (code == EQ_EXPR || code == NE_EXPR))))
7861 tree varop, newconst;
7863 if (TREE_CODE (arg0) == POSTINCREMENT_EXPR)
7865 newconst = fold (build2 (PLUS_EXPR, TREE_TYPE (arg0),
7866 arg1, TREE_OPERAND (arg0, 1)));
7867 varop = build2 (PREINCREMENT_EXPR, TREE_TYPE (arg0),
7868 TREE_OPERAND (arg0, 0),
7869 TREE_OPERAND (arg0, 1));
7873 newconst = fold (build2 (MINUS_EXPR, TREE_TYPE (arg0),
7874 arg1, TREE_OPERAND (arg0, 1)));
7875 varop = build2 (PREDECREMENT_EXPR, TREE_TYPE (arg0),
7876 TREE_OPERAND (arg0, 0),
7877 TREE_OPERAND (arg0, 1));
7881 /* If VAROP is a reference to a bitfield, we must mask
7882 the constant by the width of the field. */
7883 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
7884 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (varop, 0), 1)))
7886 tree fielddecl = TREE_OPERAND (TREE_OPERAND (varop, 0), 1);
7887 int size = TREE_INT_CST_LOW (DECL_SIZE (fielddecl));
7888 tree folded_compare, shift;
7890 /* First check whether the comparison would come out
7891 always the same. If we don't do that we would
7892 change the meaning with the masking. */
7893 folded_compare = fold (build2 (code, type,
7894 TREE_OPERAND (varop, 0),
7896 if (integer_zerop (folded_compare)
7897 || integer_onep (folded_compare))
7898 return omit_one_operand (type, folded_compare, varop);
7900 shift = build_int_2 (TYPE_PRECISION (TREE_TYPE (varop)) - size,
7902 newconst = fold (build2 (LSHIFT_EXPR, TREE_TYPE (varop),
7904 newconst = fold (build2 (RSHIFT_EXPR, TREE_TYPE (varop),
7908 return fold (build2 (code, type, varop, newconst));
7911 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
7912 This transformation affects the cases which are handled in later
7913 optimizations involving comparisons with non-negative constants. */
7914 if (TREE_CODE (arg1) == INTEGER_CST
7915 && TREE_CODE (arg0) != INTEGER_CST
7916 && tree_int_cst_sgn (arg1) > 0)
7921 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
7922 return fold (build2 (GT_EXPR, type, arg0, arg1));
7925 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
7926 return fold (build2 (LE_EXPR, type, arg0, arg1));
7933 /* Comparisons with the highest or lowest possible integer of
7934 the specified size will have known values.
7936 This is quite similar to fold_relational_hi_lo; however, my
7937 attempts to share the code have been nothing but trouble.
7938 I give up for now. */
7940 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1)));
7942 if (TREE_CODE (arg1) == INTEGER_CST
7943 && ! TREE_CONSTANT_OVERFLOW (arg1)
7944 && width <= HOST_BITS_PER_WIDE_INT
7945 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
7946 || POINTER_TYPE_P (TREE_TYPE (arg1))))
7948 unsigned HOST_WIDE_INT signed_max;
7949 unsigned HOST_WIDE_INT max, min;
7951 signed_max = ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1;
7953 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
7955 max = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
7961 min = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
7964 if (TREE_INT_CST_HIGH (arg1) == 0
7965 && TREE_INT_CST_LOW (arg1) == max)
7969 return omit_one_operand (type, integer_zero_node, arg0);
7972 return fold (build2 (EQ_EXPR, type, arg0, arg1));
7975 return omit_one_operand (type, integer_one_node, arg0);
7978 return fold (build2 (NE_EXPR, type, arg0, arg1));
7980 /* The GE_EXPR and LT_EXPR cases above are not normally
7981 reached because of previous transformations. */
7986 else if (TREE_INT_CST_HIGH (arg1) == 0
7987 && TREE_INT_CST_LOW (arg1) == max - 1)
7991 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
7992 return fold (build2 (EQ_EXPR, type, arg0, arg1));
7994 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
7995 return fold (build2 (NE_EXPR, type, arg0, arg1));
7999 else if (TREE_INT_CST_HIGH (arg1) == (min ? -1 : 0)
8000 && TREE_INT_CST_LOW (arg1) == min)
8004 return omit_one_operand (type, integer_zero_node, arg0);
8007 return fold (build2 (EQ_EXPR, type, arg0, arg1));
8010 return omit_one_operand (type, integer_one_node, arg0);
8013 return fold (build2 (NE_EXPR, type, arg0, arg1));
8018 else if (TREE_INT_CST_HIGH (arg1) == (min ? -1 : 0)
8019 && TREE_INT_CST_LOW (arg1) == min + 1)
8023 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
8024 return fold (build2 (NE_EXPR, type, arg0, arg1));
8026 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
8027 return fold (build2 (EQ_EXPR, type, arg0, arg1));
8032 else if (!in_gimple_form
8033 && TREE_INT_CST_HIGH (arg1) == 0
8034 && TREE_INT_CST_LOW (arg1) == signed_max
8035 && TYPE_UNSIGNED (TREE_TYPE (arg1))
8036 /* signed_type does not work on pointer types. */
8037 && INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
8039 /* The following case also applies to X < signed_max+1
8040 and X >= signed_max+1 because previous transformations. */
8041 if (code == LE_EXPR || code == GT_EXPR)
8044 st0 = lang_hooks.types.signed_type (TREE_TYPE (arg0));
8045 st1 = lang_hooks.types.signed_type (TREE_TYPE (arg1));
8047 (build2 (code == LE_EXPR ? GE_EXPR: LT_EXPR,
8048 type, fold_convert (st0, arg0),
8049 fold_convert (st1, integer_zero_node)));
8055 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
8056 a MINUS_EXPR of a constant, we can convert it into a comparison with
8057 a revised constant as long as no overflow occurs. */
8058 if ((code == EQ_EXPR || code == NE_EXPR)
8059 && TREE_CODE (arg1) == INTEGER_CST
8060 && (TREE_CODE (arg0) == PLUS_EXPR
8061 || TREE_CODE (arg0) == MINUS_EXPR)
8062 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8063 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
8064 ? MINUS_EXPR : PLUS_EXPR,
8065 arg1, TREE_OPERAND (arg0, 1), 0))
8066 && ! TREE_CONSTANT_OVERFLOW (tem))
8067 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), tem));
8069 /* Similarly for a NEGATE_EXPR. */
8070 else if ((code == EQ_EXPR || code == NE_EXPR)
8071 && TREE_CODE (arg0) == NEGATE_EXPR
8072 && TREE_CODE (arg1) == INTEGER_CST
8073 && 0 != (tem = negate_expr (arg1))
8074 && TREE_CODE (tem) == INTEGER_CST
8075 && ! TREE_CONSTANT_OVERFLOW (tem))
8076 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), tem));
8078 /* If we have X - Y == 0, we can convert that to X == Y and similarly
8079 for !=. Don't do this for ordered comparisons due to overflow. */
8080 else if ((code == NE_EXPR || code == EQ_EXPR)
8081 && integer_zerop (arg1) && TREE_CODE (arg0) == MINUS_EXPR)
8082 return fold (build2 (code, type,
8083 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1)));
8085 /* If we are widening one operand of an integer comparison,
8086 see if the other operand is similarly being widened. Perhaps we
8087 can do the comparison in the narrower type. */
8088 else if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
8089 && TREE_CODE (arg0) == NOP_EXPR
8090 && (tem = get_unwidened (arg0, NULL_TREE)) != arg0
8091 && (code == EQ_EXPR || code == NE_EXPR
8092 || TYPE_UNSIGNED (TREE_TYPE (arg0))
8093 == TYPE_UNSIGNED (TREE_TYPE (tem)))
8094 && (t1 = get_unwidened (arg1, TREE_TYPE (tem))) != 0
8095 && (TREE_TYPE (t1) == TREE_TYPE (tem)
8096 || (TREE_CODE (t1) == INTEGER_CST
8097 && int_fits_type_p (t1, TREE_TYPE (tem)))))
8098 return fold (build2 (code, type, tem,
8099 fold_convert (TREE_TYPE (tem), t1)));
8101 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
8102 constant, we can simplify it. */
8103 else if (TREE_CODE (arg1) == INTEGER_CST
8104 && (TREE_CODE (arg0) == MIN_EXPR
8105 || TREE_CODE (arg0) == MAX_EXPR)
8106 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8107 return optimize_minmax_comparison (t);
8109 /* If we are comparing an ABS_EXPR with a constant, we can
8110 convert all the cases into explicit comparisons, but they may
8111 well not be faster than doing the ABS and one comparison.
8112 But ABS (X) <= C is a range comparison, which becomes a subtraction
8113 and a comparison, and is probably faster. */
8114 else if (code == LE_EXPR && TREE_CODE (arg1) == INTEGER_CST
8115 && TREE_CODE (arg0) == ABS_EXPR
8116 && ! TREE_SIDE_EFFECTS (arg0)
8117 && (0 != (tem = negate_expr (arg1)))
8118 && TREE_CODE (tem) == INTEGER_CST
8119 && ! TREE_CONSTANT_OVERFLOW (tem))
8120 return fold (build2 (TRUTH_ANDIF_EXPR, type,
8121 build2 (GE_EXPR, type,
8122 TREE_OPERAND (arg0, 0), tem),
8123 build2 (LE_EXPR, type,
8124 TREE_OPERAND (arg0, 0), arg1)));
8126 /* If this is an EQ or NE comparison with zero and ARG0 is
8127 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
8128 two operations, but the latter can be done in one less insn
8129 on machines that have only two-operand insns or on which a
8130 constant cannot be the first operand. */
8131 if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR)
8132 && TREE_CODE (arg0) == BIT_AND_EXPR)
8134 tree arg00 = TREE_OPERAND (arg0, 0);
8135 tree arg01 = TREE_OPERAND (arg0, 1);
8136 if (TREE_CODE (arg00) == LSHIFT_EXPR
8137 && integer_onep (TREE_OPERAND (arg00, 0)))
8139 fold (build2 (code, type,
8140 build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
8141 build2 (RSHIFT_EXPR, TREE_TYPE (arg00),
8142 arg01, TREE_OPERAND (arg00, 1)),
8143 fold_convert (TREE_TYPE (arg0),
8146 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
8147 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
8149 fold (build2 (code, type,
8150 build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
8151 build2 (RSHIFT_EXPR, TREE_TYPE (arg01),
8152 arg00, TREE_OPERAND (arg01, 1)),
8153 fold_convert (TREE_TYPE (arg0),
8158 /* If this is an NE or EQ comparison of zero against the result of a
8159 signed MOD operation whose second operand is a power of 2, make
8160 the MOD operation unsigned since it is simpler and equivalent. */
8161 if ((code == NE_EXPR || code == EQ_EXPR)
8162 && integer_zerop (arg1)
8163 && !TYPE_UNSIGNED (TREE_TYPE (arg0))
8164 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
8165 || TREE_CODE (arg0) == CEIL_MOD_EXPR
8166 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
8167 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
8168 && integer_pow2p (TREE_OPERAND (arg0, 1)))
8170 tree newtype = lang_hooks.types.unsigned_type (TREE_TYPE (arg0));
8171 tree newmod = build2 (TREE_CODE (arg0), newtype,
8172 fold_convert (newtype,
8173 TREE_OPERAND (arg0, 0)),
8174 fold_convert (newtype,
8175 TREE_OPERAND (arg0, 1)));
8177 return build2 (code, type, newmod, fold_convert (newtype, arg1));
8180 /* If this is an NE comparison of zero with an AND of one, remove the
8181 comparison since the AND will give the correct value. */
8182 if (code == NE_EXPR && integer_zerop (arg1)
8183 && TREE_CODE (arg0) == BIT_AND_EXPR
8184 && integer_onep (TREE_OPERAND (arg0, 1)))
8185 return fold_convert (type, arg0);
8187 /* If we have (A & C) == C where C is a power of 2, convert this into
8188 (A & C) != 0. Similarly for NE_EXPR. */
8189 if ((code == EQ_EXPR || code == NE_EXPR)
8190 && TREE_CODE (arg0) == BIT_AND_EXPR
8191 && integer_pow2p (TREE_OPERAND (arg0, 1))
8192 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
8193 return fold (build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
8194 arg0, integer_zero_node));
8196 /* If we have (A & C) != 0 or (A & C) == 0 and C is a power of
8197 2, then fold the expression into shifts and logical operations. */
8198 tem = fold_single_bit_test (code, arg0, arg1, type);
8202 /* If we have (A & C) == D where D & ~C != 0, convert this into 0.
8203 Similarly for NE_EXPR. */
8204 if ((code == EQ_EXPR || code == NE_EXPR)
8205 && TREE_CODE (arg0) == BIT_AND_EXPR
8206 && TREE_CODE (arg1) == INTEGER_CST
8207 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8210 = fold (build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
8211 arg1, build1 (BIT_NOT_EXPR,
8212 TREE_TYPE (TREE_OPERAND (arg0, 1)),
8213 TREE_OPERAND (arg0, 1))));
8214 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
8215 if (integer_nonzerop (dandnotc))
8216 return omit_one_operand (type, rslt, arg0);
8219 /* If we have (A | C) == D where C & ~D != 0, convert this into 0.
8220 Similarly for NE_EXPR. */
8221 if ((code == EQ_EXPR || code == NE_EXPR)
8222 && TREE_CODE (arg0) == BIT_IOR_EXPR
8223 && TREE_CODE (arg1) == INTEGER_CST
8224 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8227 = fold (build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
8228 TREE_OPERAND (arg0, 1),
8229 build1 (BIT_NOT_EXPR, TREE_TYPE (arg1), arg1)));
8230 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
8231 if (integer_nonzerop (candnotd))
8232 return omit_one_operand (type, rslt, arg0);
8235 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
8236 and similarly for >= into !=. */
8237 if ((code == LT_EXPR || code == GE_EXPR)
8238 && TYPE_UNSIGNED (TREE_TYPE (arg0))
8239 && TREE_CODE (arg1) == LSHIFT_EXPR
8240 && integer_onep (TREE_OPERAND (arg1, 0)))
8241 return build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
8242 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
8243 TREE_OPERAND (arg1, 1)),
8244 fold_convert (TREE_TYPE (arg0), integer_zero_node));
8246 else if ((code == LT_EXPR || code == GE_EXPR)
8247 && TYPE_UNSIGNED (TREE_TYPE (arg0))
8248 && (TREE_CODE (arg1) == NOP_EXPR
8249 || TREE_CODE (arg1) == CONVERT_EXPR)
8250 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
8251 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
8253 build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
8254 fold_convert (TREE_TYPE (arg0),
8255 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
8256 TREE_OPERAND (TREE_OPERAND (arg1, 0),
8258 fold_convert (TREE_TYPE (arg0), integer_zero_node));
8260 /* Simplify comparison of something with itself. (For IEEE
8261 floating-point, we can only do some of these simplifications.) */
8262 if (operand_equal_p (arg0, arg1, 0))
8267 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
8268 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8269 return constant_boolean_node (1, type);
8274 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
8275 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8276 return constant_boolean_node (1, type);
8277 return fold (build2 (EQ_EXPR, type, arg0, arg1));
8280 /* For NE, we can only do this simplification if integer
8281 or we don't honor IEEE floating point NaNs. */
8282 if (FLOAT_TYPE_P (TREE_TYPE (arg0))
8283 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8285 /* ... fall through ... */
8288 return constant_boolean_node (0, type);
8294 /* If we are comparing an expression that just has comparisons
8295 of two integer values, arithmetic expressions of those comparisons,
8296 and constants, we can simplify it. There are only three cases
8297 to check: the two values can either be equal, the first can be
8298 greater, or the second can be greater. Fold the expression for
8299 those three values. Since each value must be 0 or 1, we have
8300 eight possibilities, each of which corresponds to the constant 0
8301 or 1 or one of the six possible comparisons.
8303 This handles common cases like (a > b) == 0 but also handles
8304 expressions like ((x > y) - (y > x)) > 0, which supposedly
8305 occur in macroized code. */
8307 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
8309 tree cval1 = 0, cval2 = 0;
8312 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
8313 /* Don't handle degenerate cases here; they should already
8314 have been handled anyway. */
8315 && cval1 != 0 && cval2 != 0
8316 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
8317 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
8318 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
8319 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
8320 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
8321 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
8322 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
8324 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
8325 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
8327 /* We can't just pass T to eval_subst in case cval1 or cval2
8328 was the same as ARG1. */
8331 = fold (build2 (code, type,
8332 eval_subst (arg0, cval1, maxval,
8336 = fold (build2 (code, type,
8337 eval_subst (arg0, cval1, maxval,
8341 = fold (build2 (code, type,
8342 eval_subst (arg0, cval1, minval,
8346 /* All three of these results should be 0 or 1. Confirm they
8347 are. Then use those values to select the proper code
8350 if ((integer_zerop (high_result)
8351 || integer_onep (high_result))
8352 && (integer_zerop (equal_result)
8353 || integer_onep (equal_result))
8354 && (integer_zerop (low_result)
8355 || integer_onep (low_result)))
8357 /* Make a 3-bit mask with the high-order bit being the
8358 value for `>', the next for '=', and the low for '<'. */
8359 switch ((integer_onep (high_result) * 4)
8360 + (integer_onep (equal_result) * 2)
8361 + integer_onep (low_result))
8365 return omit_one_operand (type, integer_zero_node, arg0);
8386 return omit_one_operand (type, integer_one_node, arg0);
8389 tem = build2 (code, type, cval1, cval2);
8391 return save_expr (tem);
8398 /* If this is a comparison of a field, we may be able to simplify it. */
8399 if (((TREE_CODE (arg0) == COMPONENT_REF
8400 && lang_hooks.can_use_bit_fields_p ())
8401 || TREE_CODE (arg0) == BIT_FIELD_REF)
8402 && (code == EQ_EXPR || code == NE_EXPR)
8403 /* Handle the constant case even without -O
8404 to make sure the warnings are given. */
8405 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
8407 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
8412 /* If this is a comparison of complex values and either or both sides
8413 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
8414 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
8415 This may prevent needless evaluations. */
8416 if ((code == EQ_EXPR || code == NE_EXPR)
8417 && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
8418 && (TREE_CODE (arg0) == COMPLEX_EXPR
8419 || TREE_CODE (arg1) == COMPLEX_EXPR
8420 || TREE_CODE (arg0) == COMPLEX_CST
8421 || TREE_CODE (arg1) == COMPLEX_CST))
8423 tree subtype = TREE_TYPE (TREE_TYPE (arg0));
8424 tree real0, imag0, real1, imag1;
8426 arg0 = save_expr (arg0);
8427 arg1 = save_expr (arg1);
8428 real0 = fold (build1 (REALPART_EXPR, subtype, arg0));
8429 imag0 = fold (build1 (IMAGPART_EXPR, subtype, arg0));
8430 real1 = fold (build1 (REALPART_EXPR, subtype, arg1));
8431 imag1 = fold (build1 (IMAGPART_EXPR, subtype, arg1));
8433 return fold (build2 ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR
8436 fold (build2 (code, type, real0, real1)),
8437 fold (build2 (code, type, imag0, imag1))));
8440 /* Optimize comparisons of strlen vs zero to a compare of the
8441 first character of the string vs zero. To wit,
8442 strlen(ptr) == 0 => *ptr == 0
8443 strlen(ptr) != 0 => *ptr != 0
8444 Other cases should reduce to one of these two (or a constant)
8445 due to the return value of strlen being unsigned. */
8446 if ((code == EQ_EXPR || code == NE_EXPR)
8447 && integer_zerop (arg1)
8448 && TREE_CODE (arg0) == CALL_EXPR)
8450 tree fndecl = get_callee_fndecl (arg0);
8454 && DECL_BUILT_IN (fndecl)
8455 && DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_MD
8456 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
8457 && (arglist = TREE_OPERAND (arg0, 1))
8458 && TREE_CODE (TREE_TYPE (TREE_VALUE (arglist))) == POINTER_TYPE
8459 && ! TREE_CHAIN (arglist))
8460 return fold (build2 (code, type,
8461 build1 (INDIRECT_REF, char_type_node,
8462 TREE_VALUE(arglist)),
8463 integer_zero_node));
8466 /* We can fold X/C1 op C2 where C1 and C2 are integer constants
8467 into a single range test. */
8468 if (TREE_CODE (arg0) == TRUNC_DIV_EXPR
8469 && TREE_CODE (arg1) == INTEGER_CST
8470 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8471 && !integer_zerop (TREE_OPERAND (arg0, 1))
8472 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
8473 && !TREE_OVERFLOW (arg1))
8475 t1 = fold_div_compare (code, type, arg0, arg1);
8476 if (t1 != NULL_TREE)
8480 /* Both ARG0 and ARG1 are known to be constants at this point. */
8481 t1 = fold_relational_const (code, type, arg0, arg1);
8482 return (t1 == NULL_TREE ? t : t1);
8484 case UNORDERED_EXPR:
8492 if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
8494 t1 = fold_relational_const (code, type, arg0, arg1);
8495 if (t1 != NULL_TREE)
8499 /* If the first operand is NaN, the result is constant. */
8500 if (TREE_CODE (arg0) == REAL_CST
8501 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
8502 && (code != LTGT_EXPR || ! flag_trapping_math))
8504 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
8507 return omit_one_operand (type, t1, arg1);
8510 /* If the second operand is NaN, the result is constant. */
8511 if (TREE_CODE (arg1) == REAL_CST
8512 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg1))
8513 && (code != LTGT_EXPR || ! flag_trapping_math))
8515 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
8518 return omit_one_operand (type, t1, arg0);
8521 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
8523 tree targ0 = strip_float_extensions (arg0);
8524 tree targ1 = strip_float_extensions (arg1);
8525 tree newtype = TREE_TYPE (targ0);
8527 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
8528 newtype = TREE_TYPE (targ1);
8530 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
8531 return fold (build2 (code, type, fold_convert (newtype, targ0),
8532 fold_convert (newtype, targ1)));
8538 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
8539 so all simple results must be passed through pedantic_non_lvalue. */
8540 if (TREE_CODE (arg0) == INTEGER_CST)
8542 tem = TREE_OPERAND (t, (integer_zerop (arg0) ? 2 : 1));
8543 /* Only optimize constant conditions when the selected branch
8544 has the same type as the COND_EXPR. This avoids optimizing
8545 away "c ? x : throw", where the throw has a void type. */
8546 if (! VOID_TYPE_P (TREE_TYPE (tem))
8547 || VOID_TYPE_P (type))
8548 return pedantic_non_lvalue (tem);
8551 if (operand_equal_p (arg1, TREE_OPERAND (t, 2), 0))
8552 return pedantic_omit_one_operand (type, arg1, arg0);
8554 /* If we have A op B ? A : C, we may be able to convert this to a
8555 simpler expression, depending on the operation and the values
8556 of B and C. Signed zeros prevent all of these transformations,
8557 for reasons given above each one.
8559 Also try swapping the arguments and inverting the conditional. */
8560 if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
8561 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
8562 arg1, TREE_OPERAND (arg0, 1))
8563 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
8565 tem = fold_cond_expr_with_comparison (type, arg0,
8566 TREE_OPERAND (t, 2));
8571 if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
8572 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
8573 TREE_OPERAND (t, 2),
8574 TREE_OPERAND (arg0, 1))
8575 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (TREE_OPERAND (t, 2)))))
8577 tem = invert_truthvalue (arg0);
8578 if (TREE_CODE_CLASS (TREE_CODE (tem)) == '<')
8580 tem = fold_cond_expr_with_comparison (type, tem, arg1);
8586 /* If the second operand is simpler than the third, swap them
8587 since that produces better jump optimization results. */
8588 if (tree_swap_operands_p (TREE_OPERAND (t, 1),
8589 TREE_OPERAND (t, 2), false))
8591 /* See if this can be inverted. If it can't, possibly because
8592 it was a floating-point inequality comparison, don't do
8594 tem = invert_truthvalue (arg0);
8596 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
8597 return fold (build3 (code, type, tem,
8598 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1)));
8601 /* Convert A ? 1 : 0 to simply A. */
8602 if (integer_onep (TREE_OPERAND (t, 1))
8603 && integer_zerop (TREE_OPERAND (t, 2))
8604 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
8605 call to fold will try to move the conversion inside
8606 a COND, which will recurse. In that case, the COND_EXPR
8607 is probably the best choice, so leave it alone. */
8608 && type == TREE_TYPE (arg0))
8609 return pedantic_non_lvalue (arg0);
8611 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
8612 over COND_EXPR in cases such as floating point comparisons. */
8613 if (integer_zerop (TREE_OPERAND (t, 1))
8614 && integer_onep (TREE_OPERAND (t, 2))
8615 && truth_value_p (TREE_CODE (arg0)))
8616 return pedantic_non_lvalue (fold_convert (type,
8617 invert_truthvalue (arg0)));
8619 /* A < 0 ? <sign bit of A> : 0 is simply (A & <sign bit of A>). */
8620 if (TREE_CODE (arg0) == LT_EXPR
8621 && integer_zerop (TREE_OPERAND (arg0, 1))
8622 && integer_zerop (TREE_OPERAND (t, 2))
8623 && (tem = sign_bit_p (TREE_OPERAND (arg0, 0), arg1)))
8624 return fold_convert (type, fold (build2 (BIT_AND_EXPR,
8625 TREE_TYPE (tem), tem, arg1)));
8627 /* (A >> N) & 1 ? (1 << N) : 0 is simply A & (1 << N). A & 1 was
8628 already handled above. */
8629 if (TREE_CODE (arg0) == BIT_AND_EXPR
8630 && integer_onep (TREE_OPERAND (arg0, 1))
8631 && integer_zerop (TREE_OPERAND (t, 2))
8632 && integer_pow2p (arg1))
8634 tree tem = TREE_OPERAND (arg0, 0);
8636 if (TREE_CODE (tem) == RSHIFT_EXPR
8637 && (unsigned HOST_WIDE_INT) tree_log2 (arg1) ==
8638 TREE_INT_CST_LOW (TREE_OPERAND (tem, 1)))
8639 return fold (build2 (BIT_AND_EXPR, type,
8640 TREE_OPERAND (tem, 0), arg1));
8643 /* A & N ? N : 0 is simply A & N if N is a power of two. This
8644 is probably obsolete because the first operand should be a
8645 truth value (that's why we have the two cases above), but let's
8646 leave it in until we can confirm this for all front-ends. */
8647 if (integer_zerop (TREE_OPERAND (t, 2))
8648 && TREE_CODE (arg0) == NE_EXPR
8649 && integer_zerop (TREE_OPERAND (arg0, 1))
8650 && integer_pow2p (arg1)
8651 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
8652 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
8653 arg1, OEP_ONLY_CONST))
8654 return pedantic_non_lvalue (fold_convert (type,
8655 TREE_OPERAND (arg0, 0)));
8657 /* Convert A ? B : 0 into A && B if A and B are truth values. */
8658 if (integer_zerop (TREE_OPERAND (t, 2))
8659 && truth_value_p (TREE_CODE (arg0))
8660 && truth_value_p (TREE_CODE (arg1)))
8661 return fold (build2 (TRUTH_ANDIF_EXPR, type, arg0, arg1));
8663 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
8664 if (integer_onep (TREE_OPERAND (t, 2))
8665 && truth_value_p (TREE_CODE (arg0))
8666 && truth_value_p (TREE_CODE (arg1)))
8668 /* Only perform transformation if ARG0 is easily inverted. */
8669 tem = invert_truthvalue (arg0);
8670 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
8671 return fold (build2 (TRUTH_ORIF_EXPR, type, tem, arg1));
8674 /* Convert A ? 0 : B into !A && B if A and B are truth values. */
8675 if (integer_zerop (arg1)
8676 && truth_value_p (TREE_CODE (arg0))
8677 && truth_value_p (TREE_CODE (TREE_OPERAND (t, 2))))
8679 /* Only perform transformation if ARG0 is easily inverted. */
8680 tem = invert_truthvalue (arg0);
8681 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
8682 return fold (build2 (TRUTH_ANDIF_EXPR, type, tem,
8683 TREE_OPERAND (t, 2)));
8686 /* Convert A ? 1 : B into A || B if A and B are truth values. */
8687 if (integer_onep (arg1)
8688 && truth_value_p (TREE_CODE (arg0))
8689 && truth_value_p (TREE_CODE (TREE_OPERAND (t, 2))))
8690 return fold (build2 (TRUTH_ORIF_EXPR, type, arg0,
8691 TREE_OPERAND (t, 2)));
8696 /* When pedantic, a compound expression can be neither an lvalue
8697 nor an integer constant expression. */
8698 if (TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
8700 /* Don't let (0, 0) be null pointer constant. */
8701 tem = integer_zerop (arg1) ? build1 (NOP_EXPR, type, arg1)
8702 : fold_convert (type, arg1);
8703 return pedantic_non_lvalue (tem);
8707 return build_complex (type, arg0, arg1);
8711 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8713 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
8714 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
8715 TREE_OPERAND (arg0, 1));
8716 else if (TREE_CODE (arg0) == COMPLEX_CST)
8717 return TREE_REALPART (arg0);
8718 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8719 return fold (build2 (TREE_CODE (arg0), type,
8720 fold (build1 (REALPART_EXPR, type,
8721 TREE_OPERAND (arg0, 0))),
8722 fold (build1 (REALPART_EXPR, type,
8723 TREE_OPERAND (arg0, 1)))));
8727 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8728 return fold_convert (type, integer_zero_node);
8729 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
8730 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
8731 TREE_OPERAND (arg0, 0));
8732 else if (TREE_CODE (arg0) == COMPLEX_CST)
8733 return TREE_IMAGPART (arg0);
8734 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8735 return fold (build2 (TREE_CODE (arg0), type,
8736 fold (build1 (IMAGPART_EXPR, type,
8737 TREE_OPERAND (arg0, 0))),
8738 fold (build1 (IMAGPART_EXPR, type,
8739 TREE_OPERAND (arg0, 1)))));
8742 /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
8744 case CLEANUP_POINT_EXPR:
8745 if (! has_cleanups (arg0))
8746 return TREE_OPERAND (t, 0);
8749 enum tree_code code0 = TREE_CODE (arg0);
8750 int kind0 = TREE_CODE_CLASS (code0);
8751 tree arg00 = TREE_OPERAND (arg0, 0);
8754 if (kind0 == '1' || code0 == TRUTH_NOT_EXPR)
8755 return fold (build1 (code0, type,
8756 fold (build1 (CLEANUP_POINT_EXPR,
8757 TREE_TYPE (arg00), arg00))));
8759 if (kind0 == '<' || kind0 == '2'
8760 || code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR
8761 || code0 == TRUTH_AND_EXPR || code0 == TRUTH_OR_EXPR
8762 || code0 == TRUTH_XOR_EXPR)
8764 arg01 = TREE_OPERAND (arg0, 1);
8766 if (TREE_CONSTANT (arg00)
8767 || ((code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR)
8768 && ! has_cleanups (arg00)))
8769 return fold (build2 (code0, type, arg00,
8770 fold (build1 (CLEANUP_POINT_EXPR,
8771 TREE_TYPE (arg01), arg01))));
8773 if (TREE_CONSTANT (arg01))
8774 return fold (build2 (code0, type,
8775 fold (build1 (CLEANUP_POINT_EXPR,
8776 TREE_TYPE (arg00), arg00)),
8784 /* Check for a built-in function. */
8785 if (TREE_CODE (TREE_OPERAND (t, 0)) == ADDR_EXPR
8786 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0))
8788 && DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (t, 0), 0)))
8790 tree tmp = fold_builtin (t);
8798 } /* switch (code) */
8801 #ifdef ENABLE_FOLD_CHECKING
8804 static void fold_checksum_tree (tree, struct md5_ctx *, htab_t);
8805 static void fold_check_failed (tree, tree);
8806 void print_fold_checksum (tree);
8808 /* When --enable-checking=fold, compute a digest of expr before
8809 and after actual fold call to see if fold did not accidentally
8810 change original expr. */
8817 unsigned char checksum_before[16], checksum_after[16];
8820 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
8821 md5_init_ctx (&ctx);
8822 fold_checksum_tree (expr, &ctx, ht);
8823 md5_finish_ctx (&ctx, checksum_before);
8826 ret = fold_1 (expr);
8828 md5_init_ctx (&ctx);
8829 fold_checksum_tree (expr, &ctx, ht);
8830 md5_finish_ctx (&ctx, checksum_after);
8833 if (memcmp (checksum_before, checksum_after, 16))
8834 fold_check_failed (expr, ret);
8840 print_fold_checksum (tree expr)
8843 unsigned char checksum[16], cnt;
8846 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
8847 md5_init_ctx (&ctx);
8848 fold_checksum_tree (expr, &ctx, ht);
8849 md5_finish_ctx (&ctx, checksum);
8851 for (cnt = 0; cnt < 16; ++cnt)
8852 fprintf (stderr, "%02x", checksum[cnt]);
8853 putc ('\n', stderr);
8857 fold_check_failed (tree expr ATTRIBUTE_UNUSED, tree ret ATTRIBUTE_UNUSED)
8859 internal_error ("fold check: original tree changed by fold");
8863 fold_checksum_tree (tree expr, struct md5_ctx *ctx, htab_t ht)
8866 enum tree_code code;
8867 char buf[sizeof (struct tree_decl)];
8870 if (sizeof (struct tree_exp) + 5 * sizeof (tree)
8871 > sizeof (struct tree_decl)
8872 || sizeof (struct tree_type) > sizeof (struct tree_decl))
8876 slot = htab_find_slot (ht, expr, INSERT);
8880 code = TREE_CODE (expr);
8881 if (code == SAVE_EXPR && SAVE_EXPR_NOPLACEHOLDER (expr))
8883 /* Allow SAVE_EXPR_NOPLACEHOLDER flag to be modified. */
8884 memcpy (buf, expr, tree_size (expr));
8886 SAVE_EXPR_NOPLACEHOLDER (expr) = 0;
8888 else if (TREE_CODE_CLASS (code) == 'd' && DECL_ASSEMBLER_NAME_SET_P (expr))
8890 /* Allow DECL_ASSEMBLER_NAME to be modified. */
8891 memcpy (buf, expr, tree_size (expr));
8893 SET_DECL_ASSEMBLER_NAME (expr, NULL);
8895 else if (TREE_CODE_CLASS (code) == 't'
8896 && (TYPE_POINTER_TO (expr) || TYPE_REFERENCE_TO (expr)))
8898 /* Allow TYPE_POINTER_TO and TYPE_REFERENCE_TO to be modified. */
8899 memcpy (buf, expr, tree_size (expr));
8901 TYPE_POINTER_TO (expr) = NULL;
8902 TYPE_REFERENCE_TO (expr) = NULL;
8904 md5_process_bytes (expr, tree_size (expr), ctx);
8905 fold_checksum_tree (TREE_TYPE (expr), ctx, ht);
8906 if (TREE_CODE_CLASS (code) != 't' && TREE_CODE_CLASS (code) != 'd')
8907 fold_checksum_tree (TREE_CHAIN (expr), ctx, ht);
8908 len = TREE_CODE_LENGTH (code);
8909 switch (TREE_CODE_CLASS (code))
8915 md5_process_bytes (TREE_STRING_POINTER (expr),
8916 TREE_STRING_LENGTH (expr), ctx);
8919 fold_checksum_tree (TREE_REALPART (expr), ctx, ht);
8920 fold_checksum_tree (TREE_IMAGPART (expr), ctx, ht);
8923 fold_checksum_tree (TREE_VECTOR_CST_ELTS (expr), ctx, ht);
8933 fold_checksum_tree (TREE_PURPOSE (expr), ctx, ht);
8934 fold_checksum_tree (TREE_VALUE (expr), ctx, ht);
8937 for (i = 0; i < TREE_VEC_LENGTH (expr); ++i)
8938 fold_checksum_tree (TREE_VEC_ELT (expr, i), ctx, ht);
8947 case SAVE_EXPR: len = 2; break;
8948 case GOTO_SUBROUTINE_EXPR: len = 0; break;
8949 case RTL_EXPR: len = 0; break;
8950 case WITH_CLEANUP_EXPR: len = 2; break;
8959 for (i = 0; i < len; ++i)
8960 fold_checksum_tree (TREE_OPERAND (expr, i), ctx, ht);
8963 fold_checksum_tree (DECL_SIZE (expr), ctx, ht);
8964 fold_checksum_tree (DECL_SIZE_UNIT (expr), ctx, ht);
8965 fold_checksum_tree (DECL_NAME (expr), ctx, ht);
8966 fold_checksum_tree (DECL_CONTEXT (expr), ctx, ht);
8967 fold_checksum_tree (DECL_ARGUMENTS (expr), ctx, ht);
8968 fold_checksum_tree (DECL_RESULT_FLD (expr), ctx, ht);
8969 fold_checksum_tree (DECL_INITIAL (expr), ctx, ht);
8970 fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr), ctx, ht);
8971 fold_checksum_tree (DECL_SECTION_NAME (expr), ctx, ht);
8972 fold_checksum_tree (DECL_ATTRIBUTES (expr), ctx, ht);
8973 fold_checksum_tree (DECL_VINDEX (expr), ctx, ht);
8976 if (TREE_CODE (expr) == ENUMERAL_TYPE)
8977 fold_checksum_tree (TYPE_VALUES (expr), ctx, ht);
8978 fold_checksum_tree (TYPE_SIZE (expr), ctx, ht);
8979 fold_checksum_tree (TYPE_SIZE_UNIT (expr), ctx, ht);
8980 fold_checksum_tree (TYPE_ATTRIBUTES (expr), ctx, ht);
8981 fold_checksum_tree (TYPE_NAME (expr), ctx, ht);
8982 if (INTEGRAL_TYPE_P (expr)
8983 || SCALAR_FLOAT_TYPE_P (expr))
8985 fold_checksum_tree (TYPE_MIN_VALUE (expr), ctx, ht);
8986 fold_checksum_tree (TYPE_MAX_VALUE (expr), ctx, ht);
8988 fold_checksum_tree (TYPE_MAIN_VARIANT (expr), ctx, ht);
8989 fold_checksum_tree (TYPE_BINFO (expr), ctx, ht);
8990 fold_checksum_tree (TYPE_CONTEXT (expr), ctx, ht);
8999 /* Perform constant folding and related simplification of initializer
9000 expression EXPR. This behaves identically to "fold" but ignores
9001 potential run-time traps and exceptions that fold must preserve. */
9004 fold_initializer (tree expr)
9006 int saved_signaling_nans = flag_signaling_nans;
9007 int saved_trapping_math = flag_trapping_math;
9008 int saved_trapv = flag_trapv;
9011 flag_signaling_nans = 0;
9012 flag_trapping_math = 0;
9015 result = fold (expr);
9017 flag_signaling_nans = saved_signaling_nans;
9018 flag_trapping_math = saved_trapping_math;
9019 flag_trapv = saved_trapv;
9024 /* Determine if first argument is a multiple of second argument. Return 0 if
9025 it is not, or we cannot easily determined it to be.
9027 An example of the sort of thing we care about (at this point; this routine
9028 could surely be made more general, and expanded to do what the *_DIV_EXPR's
9029 fold cases do now) is discovering that
9031 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
9037 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
9039 This code also handles discovering that
9041 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
9043 is a multiple of 8 so we don't have to worry about dealing with a
9046 Note that we *look* inside a SAVE_EXPR only to determine how it was
9047 calculated; it is not safe for fold to do much of anything else with the
9048 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
9049 at run time. For example, the latter example above *cannot* be implemented
9050 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
9051 evaluation time of the original SAVE_EXPR is not necessarily the same at
9052 the time the new expression is evaluated. The only optimization of this
9053 sort that would be valid is changing
9055 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
9059 SAVE_EXPR (I) * SAVE_EXPR (J)
9061 (where the same SAVE_EXPR (J) is used in the original and the
9062 transformed version). */
9065 multiple_of_p (tree type, tree top, tree bottom)
9067 if (operand_equal_p (top, bottom, 0))
9070 if (TREE_CODE (type) != INTEGER_TYPE)
9073 switch (TREE_CODE (top))
9076 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
9077 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
9081 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
9082 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
9085 if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
9089 op1 = TREE_OPERAND (top, 1);
9090 /* const_binop may not detect overflow correctly,
9091 so check for it explicitly here. */
9092 if (TYPE_PRECISION (TREE_TYPE (size_one_node))
9093 > TREE_INT_CST_LOW (op1)
9094 && TREE_INT_CST_HIGH (op1) == 0
9095 && 0 != (t1 = fold_convert (type,
9096 const_binop (LSHIFT_EXPR,
9099 && ! TREE_OVERFLOW (t1))
9100 return multiple_of_p (type, t1, bottom);
9105 /* Can't handle conversions from non-integral or wider integral type. */
9106 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
9107 || (TYPE_PRECISION (type)
9108 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
9111 /* .. fall through ... */
9114 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
9117 if (TREE_CODE (bottom) != INTEGER_CST
9118 || (TYPE_UNSIGNED (type)
9119 && (tree_int_cst_sgn (top) < 0
9120 || tree_int_cst_sgn (bottom) < 0)))
9122 return integer_zerop (const_binop (TRUNC_MOD_EXPR,
9130 /* Return true if `t' is known to be non-negative. */
9133 tree_expr_nonnegative_p (tree t)
9135 switch (TREE_CODE (t))
9141 return tree_int_cst_sgn (t) >= 0;
9144 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
9147 if (FLOAT_TYPE_P (TREE_TYPE (t)))
9148 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9149 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9151 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
9152 both unsigned and at least 2 bits shorter than the result. */
9153 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
9154 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
9155 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
9157 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
9158 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
9159 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
9160 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
9162 unsigned int prec = MAX (TYPE_PRECISION (inner1),
9163 TYPE_PRECISION (inner2)) + 1;
9164 return prec < TYPE_PRECISION (TREE_TYPE (t));
9170 if (FLOAT_TYPE_P (TREE_TYPE (t)))
9172 /* x * x for floating point x is always non-negative. */
9173 if (operand_equal_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1), 0))
9175 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9176 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9179 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
9180 both unsigned and their total bits is shorter than the result. */
9181 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
9182 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
9183 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
9185 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
9186 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
9187 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
9188 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
9189 return TYPE_PRECISION (inner1) + TYPE_PRECISION (inner2)
9190 < TYPE_PRECISION (TREE_TYPE (t));
9194 case TRUNC_DIV_EXPR:
9196 case FLOOR_DIV_EXPR:
9197 case ROUND_DIV_EXPR:
9198 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9199 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9201 case TRUNC_MOD_EXPR:
9203 case FLOOR_MOD_EXPR:
9204 case ROUND_MOD_EXPR:
9205 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9208 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9209 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9212 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
9213 || tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9216 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9217 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9221 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
9222 tree outer_type = TREE_TYPE (t);
9224 if (TREE_CODE (outer_type) == REAL_TYPE)
9226 if (TREE_CODE (inner_type) == REAL_TYPE)
9227 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9228 if (TREE_CODE (inner_type) == INTEGER_TYPE)
9230 if (TYPE_UNSIGNED (inner_type))
9232 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9235 else if (TREE_CODE (outer_type) == INTEGER_TYPE)
9237 if (TREE_CODE (inner_type) == REAL_TYPE)
9238 return tree_expr_nonnegative_p (TREE_OPERAND (t,0));
9239 if (TREE_CODE (inner_type) == INTEGER_TYPE)
9240 return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
9241 && TYPE_UNSIGNED (inner_type);
9247 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
9248 && tree_expr_nonnegative_p (TREE_OPERAND (t, 2));
9250 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9252 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9253 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9255 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9256 || tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9258 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9260 return tree_expr_nonnegative_p (expr_last (TREE_OPERAND (t, 1)));
9262 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9263 case NON_LVALUE_EXPR:
9264 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9266 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9268 return rtl_expr_nonnegative_p (RTL_EXPR_RTL (t));
9272 tree fndecl = get_callee_fndecl (t);
9273 tree arglist = TREE_OPERAND (t, 1);
9275 && DECL_BUILT_IN (fndecl)
9276 && DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_MD)
9277 switch (DECL_FUNCTION_CODE (fndecl))
9279 #define CASE_BUILTIN_F(BUILT_IN_FN) \
9280 case BUILT_IN_FN: case BUILT_IN_FN##F: case BUILT_IN_FN##L:
9281 #define CASE_BUILTIN_I(BUILT_IN_FN) \
9282 case BUILT_IN_FN: case BUILT_IN_FN##L: case BUILT_IN_FN##LL:
9284 CASE_BUILTIN_F (BUILT_IN_ACOS)
9285 CASE_BUILTIN_F (BUILT_IN_ACOSH)
9286 CASE_BUILTIN_F (BUILT_IN_CABS)
9287 CASE_BUILTIN_F (BUILT_IN_COSH)
9288 CASE_BUILTIN_F (BUILT_IN_ERFC)
9289 CASE_BUILTIN_F (BUILT_IN_EXP)
9290 CASE_BUILTIN_F (BUILT_IN_EXP10)
9291 CASE_BUILTIN_F (BUILT_IN_EXP2)
9292 CASE_BUILTIN_F (BUILT_IN_FABS)
9293 CASE_BUILTIN_F (BUILT_IN_FDIM)
9294 CASE_BUILTIN_F (BUILT_IN_FREXP)
9295 CASE_BUILTIN_F (BUILT_IN_HYPOT)
9296 CASE_BUILTIN_F (BUILT_IN_POW10)
9297 CASE_BUILTIN_I (BUILT_IN_FFS)
9298 CASE_BUILTIN_I (BUILT_IN_PARITY)
9299 CASE_BUILTIN_I (BUILT_IN_POPCOUNT)
9303 CASE_BUILTIN_F (BUILT_IN_SQRT)
9304 /* sqrt(-0.0) is -0.0. */
9305 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (t))))
9307 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
9309 CASE_BUILTIN_F (BUILT_IN_ASINH)
9310 CASE_BUILTIN_F (BUILT_IN_ATAN)
9311 CASE_BUILTIN_F (BUILT_IN_ATANH)
9312 CASE_BUILTIN_F (BUILT_IN_CBRT)
9313 CASE_BUILTIN_F (BUILT_IN_CEIL)
9314 CASE_BUILTIN_F (BUILT_IN_ERF)
9315 CASE_BUILTIN_F (BUILT_IN_EXPM1)
9316 CASE_BUILTIN_F (BUILT_IN_FLOOR)
9317 CASE_BUILTIN_F (BUILT_IN_FMOD)
9318 CASE_BUILTIN_F (BUILT_IN_LDEXP)
9319 CASE_BUILTIN_F (BUILT_IN_LLRINT)
9320 CASE_BUILTIN_F (BUILT_IN_LLROUND)
9321 CASE_BUILTIN_F (BUILT_IN_LRINT)
9322 CASE_BUILTIN_F (BUILT_IN_LROUND)
9323 CASE_BUILTIN_F (BUILT_IN_MODF)
9324 CASE_BUILTIN_F (BUILT_IN_NEARBYINT)
9325 CASE_BUILTIN_F (BUILT_IN_POW)
9326 CASE_BUILTIN_F (BUILT_IN_RINT)
9327 CASE_BUILTIN_F (BUILT_IN_ROUND)
9328 CASE_BUILTIN_F (BUILT_IN_SIGNBIT)
9329 CASE_BUILTIN_F (BUILT_IN_SINH)
9330 CASE_BUILTIN_F (BUILT_IN_TANH)
9331 CASE_BUILTIN_F (BUILT_IN_TRUNC)
9332 /* True if the 1st argument is nonnegative. */
9333 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
9335 CASE_BUILTIN_F (BUILT_IN_FMAX)
9336 /* True if the 1st OR 2nd arguments are nonnegative. */
9337 return tree_expr_nonnegative_p (TREE_VALUE (arglist))
9338 || tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist)));
9340 CASE_BUILTIN_F (BUILT_IN_FMIN)
9341 /* True if the 1st AND 2nd arguments are nonnegative. */
9342 return tree_expr_nonnegative_p (TREE_VALUE (arglist))
9343 && tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist)));
9345 CASE_BUILTIN_F (BUILT_IN_COPYSIGN)
9346 /* True if the 2nd argument is nonnegative. */
9347 return tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist)));
9351 #undef CASE_BUILTIN_F
9352 #undef CASE_BUILTIN_I
9356 /* ... fall through ... */
9359 if (truth_value_p (TREE_CODE (t)))
9360 /* Truth values evaluate to 0 or 1, which is nonnegative. */
9364 /* We don't know sign of `t', so be conservative and return false. */
9368 /* Return true when T is an address and is known to be nonzero.
9369 For floating point we further ensure that T is not denormal.
9370 Similar logic is present in nonzero_address in rtlanal.h */
9373 tree_expr_nonzero_p (tree t)
9375 tree type = TREE_TYPE (t);
9377 /* Doing something useful for floating point would need more work. */
9378 if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
9381 switch (TREE_CODE (t))
9384 if (!TYPE_UNSIGNED (type) && !flag_wrapv)
9385 return tree_expr_nonzero_p (TREE_OPERAND (t, 0));
9388 return !integer_zerop (t);
9391 if (!TYPE_UNSIGNED (type) && !flag_wrapv)
9393 /* With the presence of negative values it is hard
9394 to say something. */
9395 if (!tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9396 || !tree_expr_nonnegative_p (TREE_OPERAND (t, 1)))
9398 /* One of operands must be positive and the other non-negative. */
9399 return (tree_expr_nonzero_p (TREE_OPERAND (t, 0))
9400 || tree_expr_nonzero_p (TREE_OPERAND (t, 1)));
9405 if (!TYPE_UNSIGNED (type) && !flag_wrapv)
9407 return (tree_expr_nonzero_p (TREE_OPERAND (t, 0))
9408 && tree_expr_nonzero_p (TREE_OPERAND (t, 1)));
9414 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
9415 tree outer_type = TREE_TYPE (t);
9417 return (TYPE_PRECISION (inner_type) >= TYPE_PRECISION (outer_type)
9418 && tree_expr_nonzero_p (TREE_OPERAND (t, 0)));
9423 /* Weak declarations may link to NULL. */
9424 if (DECL_P (TREE_OPERAND (t, 0)))
9425 return !DECL_WEAK (TREE_OPERAND (t, 0));
9426 /* Constants and all other cases are never weak. */
9430 return (tree_expr_nonzero_p (TREE_OPERAND (t, 1))
9431 && tree_expr_nonzero_p (TREE_OPERAND (t, 2)));
9434 return (tree_expr_nonzero_p (TREE_OPERAND (t, 0))
9435 && tree_expr_nonzero_p (TREE_OPERAND (t, 1)));
9438 if (tree_expr_nonzero_p (TREE_OPERAND (t, 0)))
9440 /* When both operands are nonzero, then MAX must be too. */
9441 if (tree_expr_nonzero_p (TREE_OPERAND (t, 1)))
9444 /* MAX where operand 0 is positive is positive. */
9445 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9447 /* MAX where operand 1 is positive is positive. */
9448 else if (tree_expr_nonzero_p (TREE_OPERAND (t, 1))
9449 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1)))
9456 return tree_expr_nonzero_p (TREE_OPERAND (t, 1));
9459 case NON_LVALUE_EXPR:
9460 return tree_expr_nonzero_p (TREE_OPERAND (t, 0));
9463 return tree_expr_nonzero_p (TREE_OPERAND (t, 1))
9464 || tree_expr_nonzero_p (TREE_OPERAND (t, 0));
9472 /* Return true if `r' is known to be non-negative.
9473 Only handles constants at the moment. */
9476 rtl_expr_nonnegative_p (rtx r)
9478 switch (GET_CODE (r))
9481 return INTVAL (r) >= 0;
9484 if (GET_MODE (r) == VOIDmode)
9485 return CONST_DOUBLE_HIGH (r) >= 0;
9493 units = CONST_VECTOR_NUNITS (r);
9495 for (i = 0; i < units; ++i)
9497 elt = CONST_VECTOR_ELT (r, i);
9498 if (!rtl_expr_nonnegative_p (elt))
9507 /* These are always nonnegative. */
9516 /* See if we are applying CODE, a relational to the highest or lowest
9517 possible integer of TYPE. If so, then the result is a compile
9521 fold_relational_hi_lo (enum tree_code *code_p, const tree type, tree *op0_p,
9526 enum tree_code code = *code_p;
9527 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (op1)));
9529 if (TREE_CODE (op1) == INTEGER_CST
9530 && ! TREE_CONSTANT_OVERFLOW (op1)
9531 && width <= HOST_BITS_PER_WIDE_INT
9532 && (INTEGRAL_TYPE_P (TREE_TYPE (op1))
9533 || POINTER_TYPE_P (TREE_TYPE (op1))))
9535 unsigned HOST_WIDE_INT signed_max;
9536 unsigned HOST_WIDE_INT max, min;
9538 signed_max = ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1;
9540 if (TYPE_UNSIGNED (TREE_TYPE (op1)))
9542 max = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
9548 min = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
9551 if (TREE_INT_CST_HIGH (op1) == 0
9552 && TREE_INT_CST_LOW (op1) == max)
9556 return omit_one_operand (type, integer_zero_node, op0);
9562 return omit_one_operand (type, integer_one_node, op0);
9568 /* The GE_EXPR and LT_EXPR cases above are not normally
9569 reached because of previous transformations. */
9574 else if (TREE_INT_CST_HIGH (op1) == 0
9575 && TREE_INT_CST_LOW (op1) == max - 1)
9580 *op1_p = const_binop (PLUS_EXPR, op1, integer_one_node, 0);
9584 *op1_p = const_binop (PLUS_EXPR, op1, integer_one_node, 0);
9589 else if (TREE_INT_CST_HIGH (op1) == (min ? -1 : 0)
9590 && TREE_INT_CST_LOW (op1) == min)
9594 return omit_one_operand (type, integer_zero_node, op0);
9601 return omit_one_operand (type, integer_one_node, op0);
9610 else if (TREE_INT_CST_HIGH (op1) == (min ? -1 : 0)
9611 && TREE_INT_CST_LOW (op1) == min + 1)
9616 *op1_p = const_binop (MINUS_EXPR, op1, integer_one_node, 0);
9620 *op1_p = const_binop (MINUS_EXPR, op1, integer_one_node, 0);
9626 else if (TREE_INT_CST_HIGH (op1) == 0
9627 && TREE_INT_CST_LOW (op1) == signed_max
9628 && TYPE_UNSIGNED (TREE_TYPE (op1))
9629 /* signed_type does not work on pointer types. */
9630 && INTEGRAL_TYPE_P (TREE_TYPE (op1)))
9632 /* The following case also applies to X < signed_max+1
9633 and X >= signed_max+1 because previous transformations. */
9634 if (code == LE_EXPR || code == GT_EXPR)
9636 tree st0, st1, exp, retval;
9637 st0 = lang_hooks.types.signed_type (TREE_TYPE (op0));
9638 st1 = lang_hooks.types.signed_type (TREE_TYPE (op1));
9640 exp = build2 (code == LE_EXPR ? GE_EXPR: LT_EXPR,
9642 fold_convert (st0, op0),
9643 fold_convert (st1, integer_zero_node));
9646 = nondestructive_fold_binary_to_constant (TREE_CODE (exp),
9648 TREE_OPERAND (exp, 0),
9649 TREE_OPERAND (exp, 1));
9651 /* If we are in gimple form, then returning EXP would create
9652 non-gimple expressions. Clearing it is safe and insures
9653 we do not allow a non-gimple expression to escape. */
9657 return (retval ? retval : exp);
9666 /* Given the components of a binary expression CODE, TYPE, OP0 and OP1,
9667 attempt to fold the expression to a constant without modifying TYPE,
9670 If the expression could be simplified to a constant, then return
9671 the constant. If the expression would not be simplified to a
9672 constant, then return NULL_TREE.
9674 Note this is primarily designed to be called after gimplification
9675 of the tree structures and when at least one operand is a constant.
9676 As a result of those simplifying assumptions this routine is far
9677 simpler than the generic fold routine. */
9680 nondestructive_fold_binary_to_constant (enum tree_code code, tree type,
9688 /* If this is a commutative operation, and ARG0 is a constant, move it
9689 to ARG1 to reduce the number of tests below. */
9690 if (commutative_tree_code (code)
9691 && (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST))
9698 /* If either operand is a complex type, extract its real component. */
9699 if (TREE_CODE (op0) == COMPLEX_CST)
9700 subop0 = TREE_REALPART (op0);
9704 if (TREE_CODE (op1) == COMPLEX_CST)
9705 subop1 = TREE_REALPART (op1);
9709 /* Note if either argument is not a real or integer constant.
9710 With a few exceptions, simplification is limited to cases
9711 where both arguments are constants. */
9712 if ((TREE_CODE (subop0) != INTEGER_CST
9713 && TREE_CODE (subop0) != REAL_CST)
9714 || (TREE_CODE (subop1) != INTEGER_CST
9715 && TREE_CODE (subop1) != REAL_CST))
9721 /* (plus (address) (const_int)) is a constant. */
9722 if (TREE_CODE (op0) == PLUS_EXPR
9723 && TREE_CODE (op1) == INTEGER_CST
9724 && (TREE_CODE (TREE_OPERAND (op0, 0)) == ADDR_EXPR
9725 || (TREE_CODE (TREE_OPERAND (op0, 0)) == NOP_EXPR
9726 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (op0, 0), 0))
9728 && TREE_CODE (TREE_OPERAND (op0, 1)) == INTEGER_CST)
9730 return build2 (PLUS_EXPR, type, TREE_OPERAND (op0, 0),
9731 const_binop (PLUS_EXPR, op1,
9732 TREE_OPERAND (op0, 1), 0));
9740 /* Both arguments are constants. Simplify. */
9741 tem = const_binop (code, op0, op1, 0);
9742 if (tem != NULL_TREE)
9744 /* The return value should always have the same type as
9745 the original expression. */
9746 if (TREE_TYPE (tem) != type)
9747 tem = fold_convert (type, tem);
9754 /* Fold &x - &x. This can happen from &x.foo - &x.
9755 This is unsafe for certain floats even in non-IEEE formats.
9756 In IEEE, it is unsafe because it does wrong for NaNs.
9757 Also note that operand_equal_p is always false if an
9758 operand is volatile. */
9759 if (! FLOAT_TYPE_P (type) && operand_equal_p (op0, op1, 0))
9760 return fold_convert (type, integer_zero_node);
9766 /* Special case multiplication or bitwise AND where one argument
9768 if (! FLOAT_TYPE_P (type) && integer_zerop (op1))
9769 return omit_one_operand (type, op1, op0);
9771 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (op0)))
9772 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (op0)))
9773 && real_zerop (op1))
9774 return omit_one_operand (type, op1, op0);
9779 /* Special case when we know the result will be all ones. */
9780 if (integer_all_onesp (op1))
9781 return omit_one_operand (type, op1, op0);
9785 case TRUNC_DIV_EXPR:
9786 case ROUND_DIV_EXPR:
9787 case FLOOR_DIV_EXPR:
9789 case EXACT_DIV_EXPR:
9790 case TRUNC_MOD_EXPR:
9791 case ROUND_MOD_EXPR:
9792 case FLOOR_MOD_EXPR:
9795 /* Division by zero is undefined. */
9796 if (integer_zerop (op1))
9799 if (TREE_CODE (op1) == REAL_CST
9800 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (op1)))
9801 && real_zerop (op1))
9807 if (INTEGRAL_TYPE_P (type)
9808 && operand_equal_p (op1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
9809 return omit_one_operand (type, op1, op0);
9814 if (INTEGRAL_TYPE_P (type)
9815 && TYPE_MAX_VALUE (type)
9816 && operand_equal_p (op1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
9817 return omit_one_operand (type, op1, op0);
9822 /* Optimize -1 >> x for arithmetic right shifts. */
9823 if (integer_all_onesp (op0) && ! TYPE_UNSIGNED (type))
9824 return omit_one_operand (type, op0, op1);
9825 /* ... fall through ... */
9828 if (integer_zerop (op0))
9829 return omit_one_operand (type, op0, op1);
9831 /* Since negative shift count is not well-defined, don't
9832 try to compute it in the compiler. */
9833 if (TREE_CODE (op1) == INTEGER_CST && tree_int_cst_sgn (op1) < 0)
9840 /* -1 rotated either direction by any amount is still -1. */
9841 if (integer_all_onesp (op0))
9842 return omit_one_operand (type, op0, op1);
9844 /* 0 rotated either direction by any amount is still zero. */
9845 if (integer_zerop (op0))
9846 return omit_one_operand (type, op0, op1);
9852 return build_complex (type, op0, op1);
9861 /* If one arg is a real or integer constant, put it last. */
9862 if ((TREE_CODE (op0) == INTEGER_CST
9863 && TREE_CODE (op1) != INTEGER_CST)
9864 || (TREE_CODE (op0) == REAL_CST
9865 && TREE_CODE (op0) != REAL_CST))
9872 code = swap_tree_comparison (code);
9875 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
9876 This transformation affects the cases which are handled in later
9877 optimizations involving comparisons with non-negative constants. */
9878 if (TREE_CODE (op1) == INTEGER_CST
9879 && TREE_CODE (op0) != INTEGER_CST
9880 && tree_int_cst_sgn (op1) > 0)
9886 op1 = const_binop (MINUS_EXPR, op1, integer_one_node, 0);
9891 op1 = const_binop (MINUS_EXPR, op1, integer_one_node, 0);
9899 tem = fold_relational_hi_lo (&code, type, &op0, &op1);
9906 case UNORDERED_EXPR:
9916 return fold_relational_const (code, type, op0, op1);
9919 /* This could probably be handled. */
9922 case TRUTH_AND_EXPR:
9923 /* If second arg is constant zero, result is zero, but first arg
9924 must be evaluated. */
9925 if (integer_zerop (op1))
9926 return omit_one_operand (type, op1, op0);
9927 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
9928 case will be handled here. */
9929 if (integer_zerop (op0))
9930 return omit_one_operand (type, op0, op1);
9931 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
9932 return constant_boolean_node (true, type);
9936 /* If second arg is constant true, result is true, but we must
9937 evaluate first arg. */
9938 if (TREE_CODE (op1) == INTEGER_CST && ! integer_zerop (op1))
9939 return omit_one_operand (type, op1, op0);
9940 /* Likewise for first arg, but note this only occurs here for
9942 if (TREE_CODE (op0) == INTEGER_CST && ! integer_zerop (op0))
9943 return omit_one_operand (type, op0, op1);
9944 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
9945 return constant_boolean_node (false, type);
9948 case TRUTH_XOR_EXPR:
9949 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
9951 int x = ! integer_zerop (op0) ^ ! integer_zerop (op1);
9952 return constant_boolean_node (x, type);
9961 /* Given the components of a unary expression CODE, TYPE and OP0,
9962 attempt to fold the expression to a constant without modifying
9965 If the expression could be simplified to a constant, then return
9966 the constant. If the expression would not be simplified to a
9967 constant, then return NULL_TREE.
9969 Note this is primarily designed to be called after gimplification
9970 of the tree structures and when op0 is a constant. As a result
9971 of those simplifying assumptions this routine is far simpler than
9972 the generic fold routine. */
9975 nondestructive_fold_unary_to_constant (enum tree_code code, tree type,
9978 /* Make sure we have a suitable constant argument. */
9979 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
9983 if (TREE_CODE (op0) == COMPLEX_CST)
9984 subop = TREE_REALPART (op0);
9988 if (TREE_CODE (subop) != INTEGER_CST && TREE_CODE (subop) != REAL_CST)
9997 case FIX_TRUNC_EXPR:
9998 case FIX_FLOOR_EXPR:
10000 return fold_convert_const (code, type, op0);
10003 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
10004 return fold_negate_const (op0, type);
10009 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
10010 return fold_abs_const (op0, type);
10015 if (TREE_CODE (op0) == INTEGER_CST)
10016 return fold_not_const (op0, type);
10020 case REALPART_EXPR:
10021 if (TREE_CODE (op0) == COMPLEX_CST)
10022 return TREE_REALPART (op0);
10026 case IMAGPART_EXPR:
10027 if (TREE_CODE (op0) == COMPLEX_CST)
10028 return TREE_IMAGPART (op0);
10033 if (TREE_CODE (op0) == COMPLEX_CST
10034 && TREE_CODE (TREE_TYPE (op0)) == COMPLEX_TYPE)
10035 return build_complex (type, TREE_REALPART (op0),
10036 negate_expr (TREE_IMAGPART (op0)));
10044 /* If EXP represents referencing an element in a constant string
10045 (either via pointer arithmetic or array indexing), return the
10046 tree representing the value accessed, otherwise return NULL. */
10049 fold_read_from_constant_string (tree exp)
10051 if (TREE_CODE (exp) == INDIRECT_REF || TREE_CODE (exp) == ARRAY_REF)
10053 tree exp1 = TREE_OPERAND (exp, 0);
10057 if (TREE_CODE (exp) == INDIRECT_REF)
10059 string = string_constant (exp1, &index);
10063 tree domain = TYPE_DOMAIN (TREE_TYPE (exp1));
10064 tree low_bound = domain ? TYPE_MIN_VALUE (domain) : integer_zero_node;
10065 index = fold_convert (sizetype, TREE_OPERAND (exp, 1));
10067 /* Optimize the special-case of a zero lower bound.
10069 We convert the low_bound to sizetype to avoid some problems
10070 with constant folding. (E.g. suppose the lower bound is 1,
10071 and its mode is QI. Without the conversion,l (ARRAY
10072 +(INDEX-(unsigned char)1)) becomes ((ARRAY+(-(unsigned char)1))
10073 +INDEX), which becomes (ARRAY+255+INDEX). Opps!) */
10074 if (! integer_zerop (low_bound))
10075 index = size_diffop (index, fold_convert (sizetype, low_bound));
10081 && TREE_CODE (string) == STRING_CST
10082 && TREE_CODE (index) == INTEGER_CST
10083 && compare_tree_int (index, TREE_STRING_LENGTH (string)) < 0
10084 && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (string))))
10086 && (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))) == 1))
10087 return fold_convert (TREE_TYPE (exp),
10088 build_int_2 ((TREE_STRING_POINTER (string)
10089 [TREE_INT_CST_LOW (index)]), 0));
10094 /* Return the tree for neg (ARG0) when ARG0 is known to be either
10095 an integer constant or real constant.
10097 TYPE is the type of the result. */
10100 fold_negate_const (tree arg0, tree type)
10102 tree t = NULL_TREE;
10104 if (TREE_CODE (arg0) == INTEGER_CST)
10106 unsigned HOST_WIDE_INT low;
10107 HOST_WIDE_INT high;
10108 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
10109 TREE_INT_CST_HIGH (arg0),
10111 t = build_int_2 (low, high);
10112 TREE_TYPE (t) = type;
10114 = (TREE_OVERFLOW (arg0)
10115 | force_fit_type (t, overflow && !TYPE_UNSIGNED (type)));
10116 TREE_CONSTANT_OVERFLOW (t)
10117 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
10119 else if (TREE_CODE (arg0) == REAL_CST)
10120 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
10121 #ifdef ENABLE_CHECKING
10129 /* Return the tree for abs (ARG0) when ARG0 is known to be either
10130 an integer constant or real constant.
10132 TYPE is the type of the result. */
10135 fold_abs_const (tree arg0, tree type)
10137 tree t = NULL_TREE;
10139 if (TREE_CODE (arg0) == INTEGER_CST)
10141 /* If the value is unsigned, then the absolute value is
10142 the same as the ordinary value. */
10143 if (TYPE_UNSIGNED (type))
10145 /* Similarly, if the value is non-negative. */
10146 else if (INT_CST_LT (integer_minus_one_node, arg0))
10148 /* If the value is negative, then the absolute value is
10152 unsigned HOST_WIDE_INT low;
10153 HOST_WIDE_INT high;
10154 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
10155 TREE_INT_CST_HIGH (arg0),
10157 t = build_int_2 (low, high);
10158 TREE_TYPE (t) = type;
10160 = (TREE_OVERFLOW (arg0)
10161 | force_fit_type (t, overflow));
10162 TREE_CONSTANT_OVERFLOW (t)
10163 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
10167 else if (TREE_CODE (arg0) == REAL_CST)
10169 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
10170 return build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
10174 #ifdef ENABLE_CHECKING
10182 /* Return the tree for not (ARG0) when ARG0 is known to be an integer
10183 constant. TYPE is the type of the result. */
10186 fold_not_const (tree arg0, tree type)
10188 tree t = NULL_TREE;
10190 if (TREE_CODE (arg0) == INTEGER_CST)
10192 t = build_int_2 (~ TREE_INT_CST_LOW (arg0),
10193 ~ TREE_INT_CST_HIGH (arg0));
10194 TREE_TYPE (t) = type;
10195 force_fit_type (t, 0);
10196 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg0);
10197 TREE_CONSTANT_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (arg0);
10199 #ifdef ENABLE_CHECKING
10207 /* Given CODE, a relational operator, the target type, TYPE and two
10208 constant operands OP0 and OP1, return the result of the
10209 relational operation. If the result is not a compile time
10210 constant, then return NULL_TREE. */
10213 fold_relational_const (enum tree_code code, tree type, tree op0, tree op1)
10215 int result, invert;
10217 /* From here on, the only cases we handle are when the result is
10218 known to be a constant. */
10220 if (TREE_CODE (op0) == REAL_CST && TREE_CODE (op1) == REAL_CST)
10222 /* Handle the cases where either operand is a NaN. */
10223 if (REAL_VALUE_ISNAN (TREE_REAL_CST (op0))
10224 || REAL_VALUE_ISNAN (TREE_REAL_CST (op1)))
10234 case UNORDERED_EXPR:
10248 if (flag_trapping_math)
10257 return constant_boolean_node (result, type);
10260 /* From here on we're sure there are no NaNs. */
10264 return constant_boolean_node (true, type);
10266 case UNORDERED_EXPR:
10267 return constant_boolean_node (false, type);
10293 /* From here on we only handle LT, LE, GT, GE, EQ and NE.
10295 To compute GT, swap the arguments and do LT.
10296 To compute GE, do LT and invert the result.
10297 To compute LE, swap the arguments, do LT and invert the result.
10298 To compute NE, do EQ and invert the result.
10300 Therefore, the code below must handle only EQ and LT. */
10302 if (code == LE_EXPR || code == GT_EXPR)
10307 code = swap_tree_comparison (code);
10310 /* Note that it is safe to invert for real values here because we
10311 have already handled the one case that it matters. */
10314 if (code == NE_EXPR || code == GE_EXPR)
10317 code = invert_tree_comparison (code, false);
10320 /* Compute a result for LT or EQ if args permit;
10321 Otherwise return T. */
10322 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
10324 if (code == EQ_EXPR)
10325 result = tree_int_cst_equal (op0, op1);
10326 else if (TYPE_UNSIGNED (TREE_TYPE (op0)))
10327 result = INT_CST_LT_UNSIGNED (op0, op1);
10329 result = INT_CST_LT (op0, op1);
10332 else if (code == EQ_EXPR && !TREE_SIDE_EFFECTS (op0)
10333 && integer_zerop (op1) && tree_expr_nonzero_p (op0))
10336 /* Two real constants can be compared explicitly. */
10337 else if (TREE_CODE (op0) == REAL_CST && TREE_CODE (op1) == REAL_CST)
10339 if (code == EQ_EXPR)
10340 result = REAL_VALUES_EQUAL (TREE_REAL_CST (op0),
10341 TREE_REAL_CST (op1));
10343 result = REAL_VALUES_LESS (TREE_REAL_CST (op0),
10344 TREE_REAL_CST (op1));
10351 return constant_boolean_node (result, type);
10354 /* Build an expression for the address of T. Folds away INDIRECT_REF to
10355 avoid confusing the gimplify process. */
10358 build_fold_addr_expr_with_type (tree t, tree ptrtype)
10360 if (TREE_CODE (t) == INDIRECT_REF)
10362 t = TREE_OPERAND (t, 0);
10363 if (TREE_TYPE (t) != ptrtype)
10364 t = build1 (NOP_EXPR, ptrtype, t);
10369 while (TREE_CODE (base) == COMPONENT_REF
10370 || TREE_CODE (base) == ARRAY_REF)
10371 base = TREE_OPERAND (base, 0);
10373 TREE_ADDRESSABLE (base) = 1;
10375 t = build1 (ADDR_EXPR, ptrtype, t);
10382 build_fold_addr_expr (tree t)
10384 return build_fold_addr_expr_with_type (t, build_pointer_type (TREE_TYPE (t)));
10387 /* Builds an expression for an indirection through T, simplifying some
10391 build_fold_indirect_ref (tree t)
10393 tree type = TREE_TYPE (TREE_TYPE (t));
10398 if (TREE_CODE (sub) == ADDR_EXPR)
10400 tree op = TREE_OPERAND (sub, 0);
10401 tree optype = TREE_TYPE (op);
10403 if (lang_hooks.types_compatible_p (type, optype))
10405 /* *(foo *)&fooarray => fooarray[0] */
10406 else if (TREE_CODE (optype) == ARRAY_TYPE
10407 && lang_hooks.types_compatible_p (type, TREE_TYPE (optype)))
10408 return build2 (ARRAY_REF, type, op, size_zero_node);
10411 /* *(foo *)fooarrptr => (*fooarrptr)[0] */
10412 subtype = TREE_TYPE (sub);
10413 if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE
10414 && lang_hooks.types_compatible_p (type, TREE_TYPE (TREE_TYPE (subtype))))
10416 sub = build_fold_indirect_ref (sub);
10417 return build2 (ARRAY_REF, type, sub, size_zero_node);
10420 return build1 (INDIRECT_REF, type, t);
10423 #include "gt-fold-const.h"