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, an overflowable flag and prior
43 overflow indicators. It forces the value to fit the type and sets
44 TREE_OVERFLOW and TREE_CONSTANT_OVERFLOW as appropriate. */
48 #include "coretypes.h"
59 #include "langhooks.h"
62 /* The following constants represent a bit based encoding of GCC's
63 comparison operators. This encoding simplifies transformations
64 on relational comparison operators, such as AND and OR. */
65 enum comparison_code {
84 static void encode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT, HOST_WIDE_INT);
85 static void decode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
86 static bool negate_mathfn_p (enum built_in_function);
87 static bool negate_expr_p (tree);
88 static tree negate_expr (tree);
89 static tree split_tree (tree, enum tree_code, tree *, tree *, tree *, int);
90 static tree associate_trees (tree, tree, enum tree_code, tree);
91 static tree const_binop (enum tree_code, tree, tree, int);
92 static tree build_zero_vector (tree);
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, 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 fold_binary_op_with_conditional_arg (enum tree_code, tree, tree,
128 static bool fold_real_zero_addition_p (tree, tree, int);
129 static tree fold_mathfn_compare (enum built_in_function, enum tree_code,
131 static tree fold_inf_compare (enum tree_code, tree, tree, tree);
132 static tree fold_div_compare (enum tree_code, tree, tree, tree);
133 static bool reorder_operands_p (tree, tree);
134 static tree fold_negate_const (tree, tree);
135 static tree fold_not_const (tree, tree);
136 static tree fold_relational_const (enum tree_code, tree, tree, tree);
137 static tree fold_relational_hi_lo (enum tree_code *, const tree,
139 static bool tree_expr_nonzero_p (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 /* T is an INT_CST node. OVERFLOWABLE indicates if we are interested
188 in overflow of the value, when >0 we are only interested in signed
189 overflow, for <0 we are interested in any overflow. OVERFLOWED
190 indicates whether overflow has already occurred. CONST_OVERFLOWED
191 indicates whether constant overflow has already occurred. We force
192 T's value to be within range of T's type (by setting to 0 or 1 all
193 the bits outside the type's range). We set TREE_OVERFLOWED if,
194 OVERFLOWED is nonzero,
195 or OVERFLOWABLE is >0 and signed overflow occurs
196 or OVERFLOWABLE is <0 and any overflow occurs
197 We set TREE_CONSTANT_OVERFLOWED if,
198 CONST_OVERFLOWED is nonzero
199 or we set TREE_OVERFLOWED.
200 We return either the original T, or a copy. */
203 force_fit_type (tree t, int overflowable,
204 bool overflowed, bool overflowed_const)
206 unsigned HOST_WIDE_INT low;
209 int sign_extended_type;
211 gcc_assert (TREE_CODE (t) == INTEGER_CST);
213 low = TREE_INT_CST_LOW (t);
214 high = TREE_INT_CST_HIGH (t);
216 if (POINTER_TYPE_P (TREE_TYPE (t))
217 || TREE_CODE (TREE_TYPE (t)) == OFFSET_TYPE)
220 prec = TYPE_PRECISION (TREE_TYPE (t));
221 /* Size types *are* sign extended. */
222 sign_extended_type = (!TYPE_UNSIGNED (TREE_TYPE (t))
223 || (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
224 && TYPE_IS_SIZETYPE (TREE_TYPE (t))));
226 /* First clear all bits that are beyond the type's precision. */
228 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
230 else if (prec > HOST_BITS_PER_WIDE_INT)
231 high &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
235 if (prec < HOST_BITS_PER_WIDE_INT)
236 low &= ~((HOST_WIDE_INT) (-1) << prec);
239 if (!sign_extended_type)
240 /* No sign extension */;
241 else if (prec == 2 * HOST_BITS_PER_WIDE_INT)
242 /* Correct width already. */;
243 else if (prec > HOST_BITS_PER_WIDE_INT)
245 /* Sign extend top half? */
246 if (high & ((unsigned HOST_WIDE_INT)1
247 << (prec - HOST_BITS_PER_WIDE_INT - 1)))
248 high |= (HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT);
250 else if (prec == HOST_BITS_PER_WIDE_INT)
252 if ((HOST_WIDE_INT)low < 0)
257 /* Sign extend bottom half? */
258 if (low & ((unsigned HOST_WIDE_INT)1 << (prec - 1)))
261 low |= (HOST_WIDE_INT)(-1) << prec;
265 /* If the value changed, return a new node. */
266 if (overflowed || overflowed_const
267 || low != TREE_INT_CST_LOW (t) || high != TREE_INT_CST_HIGH (t))
269 t = build_int_cst_wide (TREE_TYPE (t), low, high);
273 || (overflowable > 0 && sign_extended_type))
276 TREE_OVERFLOW (t) = 1;
277 TREE_CONSTANT_OVERFLOW (t) = 1;
279 else if (overflowed_const)
282 TREE_CONSTANT_OVERFLOW (t) = 1;
289 /* Add two doubleword integers with doubleword result.
290 Each argument is given as two `HOST_WIDE_INT' pieces.
291 One argument is L1 and H1; the other, L2 and H2.
292 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
295 add_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
296 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
297 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
299 unsigned HOST_WIDE_INT l;
303 h = h1 + h2 + (l < l1);
307 return OVERFLOW_SUM_SIGN (h1, h2, h);
310 /* Negate a doubleword integer with doubleword result.
311 Return nonzero if the operation overflows, assuming it's signed.
312 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
313 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
316 neg_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
317 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
323 return (*hv & h1) < 0;
333 /* Multiply two doubleword integers with doubleword result.
334 Return nonzero if the operation overflows, assuming it's signed.
335 Each argument is given as two `HOST_WIDE_INT' pieces.
336 One argument is L1 and H1; the other, L2 and H2.
337 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
340 mul_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
341 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
342 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
344 HOST_WIDE_INT arg1[4];
345 HOST_WIDE_INT arg2[4];
346 HOST_WIDE_INT prod[4 * 2];
347 unsigned HOST_WIDE_INT carry;
349 unsigned HOST_WIDE_INT toplow, neglow;
350 HOST_WIDE_INT tophigh, neghigh;
352 encode (arg1, l1, h1);
353 encode (arg2, l2, h2);
355 memset (prod, 0, sizeof prod);
357 for (i = 0; i < 4; i++)
360 for (j = 0; j < 4; j++)
363 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
364 carry += arg1[i] * arg2[j];
365 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
367 prod[k] = LOWPART (carry);
368 carry = HIGHPART (carry);
373 decode (prod, lv, hv); /* This ignores prod[4] through prod[4*2-1] */
375 /* Check for overflow by calculating the top half of the answer in full;
376 it should agree with the low half's sign bit. */
377 decode (prod + 4, &toplow, &tophigh);
380 neg_double (l2, h2, &neglow, &neghigh);
381 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
385 neg_double (l1, h1, &neglow, &neghigh);
386 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
388 return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
391 /* Shift the doubleword integer in L1, H1 left by COUNT places
392 keeping only PREC bits of result.
393 Shift right if COUNT is negative.
394 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
395 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
398 lshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
399 HOST_WIDE_INT count, unsigned int prec,
400 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv, int arith)
402 unsigned HOST_WIDE_INT signmask;
406 rshift_double (l1, h1, -count, prec, lv, hv, arith);
410 if (SHIFT_COUNT_TRUNCATED)
413 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
415 /* Shifting by the host word size is undefined according to the
416 ANSI standard, so we must handle this as a special case. */
420 else if (count >= HOST_BITS_PER_WIDE_INT)
422 *hv = l1 << (count - HOST_BITS_PER_WIDE_INT);
427 *hv = (((unsigned HOST_WIDE_INT) h1 << count)
428 | (l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
432 /* Sign extend all bits that are beyond the precision. */
434 signmask = -((prec > HOST_BITS_PER_WIDE_INT
435 ? ((unsigned HOST_WIDE_INT) *hv
436 >> (prec - HOST_BITS_PER_WIDE_INT - 1))
437 : (*lv >> (prec - 1))) & 1);
439 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
441 else if (prec >= HOST_BITS_PER_WIDE_INT)
443 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
444 *hv |= signmask << (prec - HOST_BITS_PER_WIDE_INT);
449 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
450 *lv |= signmask << prec;
454 /* Shift the doubleword integer in L1, H1 right by COUNT places
455 keeping only PREC bits of result. COUNT must be positive.
456 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
457 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
460 rshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
461 HOST_WIDE_INT count, unsigned int prec,
462 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
465 unsigned HOST_WIDE_INT signmask;
468 ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
471 if (SHIFT_COUNT_TRUNCATED)
474 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
476 /* Shifting by the host word size is undefined according to the
477 ANSI standard, so we must handle this as a special case. */
481 else if (count >= HOST_BITS_PER_WIDE_INT)
484 *lv = (unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT);
488 *hv = (unsigned HOST_WIDE_INT) h1 >> count;
490 | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
493 /* Zero / sign extend all bits that are beyond the precision. */
495 if (count >= (HOST_WIDE_INT)prec)
500 else if ((prec - count) >= 2 * HOST_BITS_PER_WIDE_INT)
502 else if ((prec - count) >= HOST_BITS_PER_WIDE_INT)
504 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - count - HOST_BITS_PER_WIDE_INT));
505 *hv |= signmask << (prec - count - HOST_BITS_PER_WIDE_INT);
510 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << (prec - count));
511 *lv |= signmask << (prec - count);
515 /* Rotate the doubleword integer in L1, H1 left by COUNT places
516 keeping only PREC bits of result.
517 Rotate right if COUNT is negative.
518 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
521 lrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
522 HOST_WIDE_INT count, unsigned int prec,
523 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
525 unsigned HOST_WIDE_INT s1l, s2l;
526 HOST_WIDE_INT s1h, s2h;
532 lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
533 rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
538 /* Rotate the doubleword integer in L1, H1 left by COUNT places
539 keeping only PREC bits of result. COUNT must be positive.
540 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
543 rrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
544 HOST_WIDE_INT count, unsigned int prec,
545 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
547 unsigned HOST_WIDE_INT s1l, s2l;
548 HOST_WIDE_INT s1h, s2h;
554 rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
555 lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
560 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
561 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
562 CODE is a tree code for a kind of division, one of
563 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
565 It controls how the quotient is rounded to an integer.
566 Return nonzero if the operation overflows.
567 UNS nonzero says do unsigned division. */
570 div_and_round_double (enum tree_code code, int uns,
571 unsigned HOST_WIDE_INT lnum_orig, /* num == numerator == dividend */
572 HOST_WIDE_INT hnum_orig,
573 unsigned HOST_WIDE_INT lden_orig, /* den == denominator == divisor */
574 HOST_WIDE_INT hden_orig,
575 unsigned HOST_WIDE_INT *lquo,
576 HOST_WIDE_INT *hquo, unsigned HOST_WIDE_INT *lrem,
580 HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
581 HOST_WIDE_INT den[4], quo[4];
583 unsigned HOST_WIDE_INT work;
584 unsigned HOST_WIDE_INT carry = 0;
585 unsigned HOST_WIDE_INT lnum = lnum_orig;
586 HOST_WIDE_INT hnum = hnum_orig;
587 unsigned HOST_WIDE_INT lden = lden_orig;
588 HOST_WIDE_INT hden = hden_orig;
591 if (hden == 0 && lden == 0)
592 overflow = 1, lden = 1;
594 /* Calculate quotient sign and convert operands to unsigned. */
600 /* (minimum integer) / (-1) is the only overflow case. */
601 if (neg_double (lnum, hnum, &lnum, &hnum)
602 && ((HOST_WIDE_INT) lden & hden) == -1)
608 neg_double (lden, hden, &lden, &hden);
612 if (hnum == 0 && hden == 0)
613 { /* single precision */
615 /* This unsigned division rounds toward zero. */
621 { /* trivial case: dividend < divisor */
622 /* hden != 0 already checked. */
629 memset (quo, 0, sizeof quo);
631 memset (num, 0, sizeof num); /* to zero 9th element */
632 memset (den, 0, sizeof den);
634 encode (num, lnum, hnum);
635 encode (den, lden, hden);
637 /* Special code for when the divisor < BASE. */
638 if (hden == 0 && lden < (unsigned HOST_WIDE_INT) BASE)
640 /* hnum != 0 already checked. */
641 for (i = 4 - 1; i >= 0; i--)
643 work = num[i] + carry * BASE;
644 quo[i] = work / lden;
650 /* Full double precision division,
651 with thanks to Don Knuth's "Seminumerical Algorithms". */
652 int num_hi_sig, den_hi_sig;
653 unsigned HOST_WIDE_INT quo_est, scale;
655 /* Find the highest nonzero divisor digit. */
656 for (i = 4 - 1;; i--)
663 /* Insure that the first digit of the divisor is at least BASE/2.
664 This is required by the quotient digit estimation algorithm. */
666 scale = BASE / (den[den_hi_sig] + 1);
668 { /* scale divisor and dividend */
670 for (i = 0; i <= 4 - 1; i++)
672 work = (num[i] * scale) + carry;
673 num[i] = LOWPART (work);
674 carry = HIGHPART (work);
679 for (i = 0; i <= 4 - 1; i++)
681 work = (den[i] * scale) + carry;
682 den[i] = LOWPART (work);
683 carry = HIGHPART (work);
684 if (den[i] != 0) den_hi_sig = i;
691 for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--)
693 /* Guess the next quotient digit, quo_est, by dividing the first
694 two remaining dividend digits by the high order quotient digit.
695 quo_est is never low and is at most 2 high. */
696 unsigned HOST_WIDE_INT tmp;
698 num_hi_sig = i + den_hi_sig + 1;
699 work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
700 if (num[num_hi_sig] != den[den_hi_sig])
701 quo_est = work / den[den_hi_sig];
705 /* Refine quo_est so it's usually correct, and at most one high. */
706 tmp = work - quo_est * den[den_hi_sig];
708 && (den[den_hi_sig - 1] * quo_est
709 > (tmp * BASE + num[num_hi_sig - 2])))
712 /* Try QUO_EST as the quotient digit, by multiplying the
713 divisor by QUO_EST and subtracting from the remaining dividend.
714 Keep in mind that QUO_EST is the I - 1st digit. */
717 for (j = 0; j <= den_hi_sig; j++)
719 work = quo_est * den[j] + carry;
720 carry = HIGHPART (work);
721 work = num[i + j] - LOWPART (work);
722 num[i + j] = LOWPART (work);
723 carry += HIGHPART (work) != 0;
726 /* If quo_est was high by one, then num[i] went negative and
727 we need to correct things. */
728 if (num[num_hi_sig] < (HOST_WIDE_INT) carry)
731 carry = 0; /* add divisor back in */
732 for (j = 0; j <= den_hi_sig; j++)
734 work = num[i + j] + den[j] + carry;
735 carry = HIGHPART (work);
736 num[i + j] = LOWPART (work);
739 num [num_hi_sig] += carry;
742 /* Store the quotient digit. */
747 decode (quo, lquo, hquo);
750 /* If result is negative, make it so. */
752 neg_double (*lquo, *hquo, lquo, hquo);
754 /* Compute trial remainder: rem = num - (quo * den) */
755 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
756 neg_double (*lrem, *hrem, lrem, hrem);
757 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
762 case TRUNC_MOD_EXPR: /* round toward zero */
763 case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
767 case FLOOR_MOD_EXPR: /* round toward negative infinity */
768 if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
771 add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
779 case CEIL_MOD_EXPR: /* round toward positive infinity */
780 if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
782 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
790 case ROUND_MOD_EXPR: /* round to closest integer */
792 unsigned HOST_WIDE_INT labs_rem = *lrem;
793 HOST_WIDE_INT habs_rem = *hrem;
794 unsigned HOST_WIDE_INT labs_den = lden, ltwice;
795 HOST_WIDE_INT habs_den = hden, htwice;
797 /* Get absolute values. */
799 neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
801 neg_double (lden, hden, &labs_den, &habs_den);
803 /* If (2 * abs (lrem) >= abs (lden)) */
804 mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
805 labs_rem, habs_rem, <wice, &htwice);
807 if (((unsigned HOST_WIDE_INT) habs_den
808 < (unsigned HOST_WIDE_INT) htwice)
809 || (((unsigned HOST_WIDE_INT) habs_den
810 == (unsigned HOST_WIDE_INT) htwice)
811 && (labs_den < ltwice)))
815 add_double (*lquo, *hquo,
816 (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
819 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
831 /* Compute true remainder: rem = num - (quo * den) */
832 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
833 neg_double (*lrem, *hrem, lrem, hrem);
834 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
838 /* Return true if built-in mathematical function specified by CODE
839 preserves the sign of it argument, i.e. -f(x) == f(-x). */
842 negate_mathfn_p (enum built_in_function code)
866 /* Check whether we may negate an integer constant T without causing
870 may_negate_without_overflow_p (tree t)
872 unsigned HOST_WIDE_INT val;
876 gcc_assert (TREE_CODE (t) == INTEGER_CST);
878 type = TREE_TYPE (t);
879 if (TYPE_UNSIGNED (type))
882 prec = TYPE_PRECISION (type);
883 if (prec > HOST_BITS_PER_WIDE_INT)
885 if (TREE_INT_CST_LOW (t) != 0)
887 prec -= HOST_BITS_PER_WIDE_INT;
888 val = TREE_INT_CST_HIGH (t);
891 val = TREE_INT_CST_LOW (t);
892 if (prec < HOST_BITS_PER_WIDE_INT)
893 val &= ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
894 return val != ((unsigned HOST_WIDE_INT) 1 << (prec - 1));
897 /* Determine whether an expression T can be cheaply negated using
898 the function negate_expr. */
901 negate_expr_p (tree t)
908 type = TREE_TYPE (t);
911 switch (TREE_CODE (t))
914 if (TYPE_UNSIGNED (type) || ! flag_trapv)
917 /* Check that -CST will not overflow type. */
918 return may_negate_without_overflow_p (t);
925 return negate_expr_p (TREE_REALPART (t))
926 && negate_expr_p (TREE_IMAGPART (t));
929 if (FLOAT_TYPE_P (type) && !flag_unsafe_math_optimizations)
931 /* -(A + B) -> (-B) - A. */
932 if (negate_expr_p (TREE_OPERAND (t, 1))
933 && reorder_operands_p (TREE_OPERAND (t, 0),
934 TREE_OPERAND (t, 1)))
936 /* -(A + B) -> (-A) - B. */
937 return negate_expr_p (TREE_OPERAND (t, 0));
940 /* We can't turn -(A-B) into B-A when we honor signed zeros. */
941 return (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
942 && reorder_operands_p (TREE_OPERAND (t, 0),
943 TREE_OPERAND (t, 1));
946 if (TYPE_UNSIGNED (TREE_TYPE (t)))
952 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
953 return negate_expr_p (TREE_OPERAND (t, 1))
954 || negate_expr_p (TREE_OPERAND (t, 0));
958 /* Negate -((double)float) as (double)(-float). */
959 if (TREE_CODE (type) == REAL_TYPE)
961 tree tem = strip_float_extensions (t);
963 return negate_expr_p (tem);
968 /* Negate -f(x) as f(-x). */
969 if (negate_mathfn_p (builtin_mathfn_code (t)))
970 return negate_expr_p (TREE_VALUE (TREE_OPERAND (t, 1)));
974 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
975 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
977 tree op1 = TREE_OPERAND (t, 1);
978 if (TREE_INT_CST_HIGH (op1) == 0
979 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
980 == TREE_INT_CST_LOW (op1))
991 /* Given T, an expression, return the negation of T. Allow for T to be
992 null, in which case return null. */
1003 type = TREE_TYPE (t);
1004 STRIP_SIGN_NOPS (t);
1006 switch (TREE_CODE (t))
1009 tem = fold_negate_const (t, type);
1010 if (! TREE_OVERFLOW (tem)
1011 || TYPE_UNSIGNED (type)
1017 tem = fold_negate_const (t, type);
1018 /* Two's complement FP formats, such as c4x, may overflow. */
1019 if (! TREE_OVERFLOW (tem) || ! flag_trapping_math)
1020 return fold_convert (type, tem);
1025 tree rpart = negate_expr (TREE_REALPART (t));
1026 tree ipart = negate_expr (TREE_IMAGPART (t));
1028 if ((TREE_CODE (rpart) == REAL_CST
1029 && TREE_CODE (ipart) == REAL_CST)
1030 || (TREE_CODE (rpart) == INTEGER_CST
1031 && TREE_CODE (ipart) == INTEGER_CST))
1032 return build_complex (type, rpart, ipart);
1037 return fold_convert (type, TREE_OPERAND (t, 0));
1040 if (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
1042 /* -(A + B) -> (-B) - A. */
1043 if (negate_expr_p (TREE_OPERAND (t, 1))
1044 && reorder_operands_p (TREE_OPERAND (t, 0),
1045 TREE_OPERAND (t, 1)))
1047 tem = negate_expr (TREE_OPERAND (t, 1));
1048 tem = fold (build2 (MINUS_EXPR, TREE_TYPE (t),
1049 tem, TREE_OPERAND (t, 0)));
1050 return fold_convert (type, tem);
1053 /* -(A + B) -> (-A) - B. */
1054 if (negate_expr_p (TREE_OPERAND (t, 0)))
1056 tem = negate_expr (TREE_OPERAND (t, 0));
1057 tem = fold (build2 (MINUS_EXPR, TREE_TYPE (t),
1058 tem, TREE_OPERAND (t, 1)));
1059 return fold_convert (type, tem);
1065 /* - (A - B) -> B - A */
1066 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
1067 && reorder_operands_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1)))
1068 return fold_convert (type,
1069 fold (build2 (MINUS_EXPR, TREE_TYPE (t),
1070 TREE_OPERAND (t, 1),
1071 TREE_OPERAND (t, 0))));
1075 if (TYPE_UNSIGNED (TREE_TYPE (t)))
1081 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
1083 tem = TREE_OPERAND (t, 1);
1084 if (negate_expr_p (tem))
1085 return fold_convert (type,
1086 fold (build2 (TREE_CODE (t), TREE_TYPE (t),
1087 TREE_OPERAND (t, 0),
1088 negate_expr (tem))));
1089 tem = TREE_OPERAND (t, 0);
1090 if (negate_expr_p (tem))
1091 return fold_convert (type,
1092 fold (build2 (TREE_CODE (t), TREE_TYPE (t),
1094 TREE_OPERAND (t, 1))));
1099 /* Convert -((double)float) into (double)(-float). */
1100 if (TREE_CODE (type) == REAL_TYPE)
1102 tem = strip_float_extensions (t);
1103 if (tem != t && negate_expr_p (tem))
1104 return fold_convert (type, negate_expr (tem));
1109 /* Negate -f(x) as f(-x). */
1110 if (negate_mathfn_p (builtin_mathfn_code (t))
1111 && negate_expr_p (TREE_VALUE (TREE_OPERAND (t, 1))))
1113 tree fndecl, arg, arglist;
1115 fndecl = get_callee_fndecl (t);
1116 arg = negate_expr (TREE_VALUE (TREE_OPERAND (t, 1)));
1117 arglist = build_tree_list (NULL_TREE, arg);
1118 return build_function_call_expr (fndecl, arglist);
1123 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1124 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
1126 tree op1 = TREE_OPERAND (t, 1);
1127 if (TREE_INT_CST_HIGH (op1) == 0
1128 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
1129 == TREE_INT_CST_LOW (op1))
1131 tree ntype = TYPE_UNSIGNED (type)
1132 ? lang_hooks.types.signed_type (type)
1133 : lang_hooks.types.unsigned_type (type);
1134 tree temp = fold_convert (ntype, TREE_OPERAND (t, 0));
1135 temp = fold (build2 (RSHIFT_EXPR, ntype, temp, op1));
1136 return fold_convert (type, temp);
1145 tem = fold (build1 (NEGATE_EXPR, TREE_TYPE (t), t));
1146 return fold_convert (type, tem);
1149 /* Split a tree IN into a constant, literal and variable parts that could be
1150 combined with CODE to make IN. "constant" means an expression with
1151 TREE_CONSTANT but that isn't an actual constant. CODE must be a
1152 commutative arithmetic operation. Store the constant part into *CONP,
1153 the literal in *LITP and return the variable part. If a part isn't
1154 present, set it to null. If the tree does not decompose in this way,
1155 return the entire tree as the variable part and the other parts as null.
1157 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
1158 case, we negate an operand that was subtracted. Except if it is a
1159 literal for which we use *MINUS_LITP instead.
1161 If NEGATE_P is true, we are negating all of IN, again except a literal
1162 for which we use *MINUS_LITP instead.
1164 If IN is itself a literal or constant, return it as appropriate.
1166 Note that we do not guarantee that any of the three values will be the
1167 same type as IN, but they will have the same signedness and mode. */
1170 split_tree (tree in, enum tree_code code, tree *conp, tree *litp,
1171 tree *minus_litp, int negate_p)
1179 /* Strip any conversions that don't change the machine mode or signedness. */
1180 STRIP_SIGN_NOPS (in);
1182 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST)
1184 else if (TREE_CODE (in) == code
1185 || (! FLOAT_TYPE_P (TREE_TYPE (in))
1186 /* We can associate addition and subtraction together (even
1187 though the C standard doesn't say so) for integers because
1188 the value is not affected. For reals, the value might be
1189 affected, so we can't. */
1190 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
1191 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
1193 tree op0 = TREE_OPERAND (in, 0);
1194 tree op1 = TREE_OPERAND (in, 1);
1195 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
1196 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
1198 /* First see if either of the operands is a literal, then a constant. */
1199 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
1200 *litp = op0, op0 = 0;
1201 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST)
1202 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
1204 if (op0 != 0 && TREE_CONSTANT (op0))
1205 *conp = op0, op0 = 0;
1206 else if (op1 != 0 && TREE_CONSTANT (op1))
1207 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
1209 /* If we haven't dealt with either operand, this is not a case we can
1210 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1211 if (op0 != 0 && op1 != 0)
1216 var = op1, neg_var_p = neg1_p;
1218 /* Now do any needed negations. */
1220 *minus_litp = *litp, *litp = 0;
1222 *conp = negate_expr (*conp);
1224 var = negate_expr (var);
1226 else if (TREE_CONSTANT (in))
1234 *minus_litp = *litp, *litp = 0;
1235 else if (*minus_litp)
1236 *litp = *minus_litp, *minus_litp = 0;
1237 *conp = negate_expr (*conp);
1238 var = negate_expr (var);
1244 /* Re-associate trees split by the above function. T1 and T2 are either
1245 expressions to associate or null. Return the new expression, if any. If
1246 we build an operation, do it in TYPE and with CODE. */
1249 associate_trees (tree t1, tree t2, enum tree_code code, tree type)
1256 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1257 try to fold this since we will have infinite recursion. But do
1258 deal with any NEGATE_EXPRs. */
1259 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
1260 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1262 if (code == PLUS_EXPR)
1264 if (TREE_CODE (t1) == NEGATE_EXPR)
1265 return build2 (MINUS_EXPR, type, fold_convert (type, t2),
1266 fold_convert (type, TREE_OPERAND (t1, 0)));
1267 else if (TREE_CODE (t2) == NEGATE_EXPR)
1268 return build2 (MINUS_EXPR, type, fold_convert (type, t1),
1269 fold_convert (type, TREE_OPERAND (t2, 0)));
1271 return build2 (code, type, fold_convert (type, t1),
1272 fold_convert (type, t2));
1275 return fold (build2 (code, type, fold_convert (type, t1),
1276 fold_convert (type, t2)));
1279 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1280 to produce a new constant.
1282 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1285 int_const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1287 unsigned HOST_WIDE_INT int1l, int2l;
1288 HOST_WIDE_INT int1h, int2h;
1289 unsigned HOST_WIDE_INT low;
1291 unsigned HOST_WIDE_INT garbagel;
1292 HOST_WIDE_INT garbageh;
1294 tree type = TREE_TYPE (arg1);
1295 int uns = TYPE_UNSIGNED (type);
1297 = (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type));
1299 int no_overflow = 0;
1301 int1l = TREE_INT_CST_LOW (arg1);
1302 int1h = TREE_INT_CST_HIGH (arg1);
1303 int2l = TREE_INT_CST_LOW (arg2);
1304 int2h = TREE_INT_CST_HIGH (arg2);
1309 low = int1l | int2l, hi = int1h | int2h;
1313 low = int1l ^ int2l, hi = int1h ^ int2h;
1317 low = int1l & int2l, hi = int1h & int2h;
1323 /* It's unclear from the C standard whether shifts can overflow.
1324 The following code ignores overflow; perhaps a C standard
1325 interpretation ruling is needed. */
1326 lshift_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1334 lrotate_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1339 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1343 neg_double (int2l, int2h, &low, &hi);
1344 add_double (int1l, int1h, low, hi, &low, &hi);
1345 overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
1349 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1352 case TRUNC_DIV_EXPR:
1353 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1354 case EXACT_DIV_EXPR:
1355 /* This is a shortcut for a common special case. */
1356 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1357 && ! TREE_CONSTANT_OVERFLOW (arg1)
1358 && ! TREE_CONSTANT_OVERFLOW (arg2)
1359 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1361 if (code == CEIL_DIV_EXPR)
1364 low = int1l / int2l, hi = 0;
1368 /* ... fall through ... */
1370 case ROUND_DIV_EXPR:
1371 if (int2h == 0 && int2l == 1)
1373 low = int1l, hi = int1h;
1376 if (int1l == int2l && int1h == int2h
1377 && ! (int1l == 0 && int1h == 0))
1382 overflow = div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
1383 &low, &hi, &garbagel, &garbageh);
1386 case TRUNC_MOD_EXPR:
1387 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1388 /* This is a shortcut for a common special case. */
1389 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1390 && ! TREE_CONSTANT_OVERFLOW (arg1)
1391 && ! TREE_CONSTANT_OVERFLOW (arg2)
1392 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1394 if (code == CEIL_MOD_EXPR)
1396 low = int1l % int2l, hi = 0;
1400 /* ... fall through ... */
1402 case ROUND_MOD_EXPR:
1403 overflow = div_and_round_double (code, uns,
1404 int1l, int1h, int2l, int2h,
1405 &garbagel, &garbageh, &low, &hi);
1411 low = (((unsigned HOST_WIDE_INT) int1h
1412 < (unsigned HOST_WIDE_INT) int2h)
1413 || (((unsigned HOST_WIDE_INT) int1h
1414 == (unsigned HOST_WIDE_INT) int2h)
1417 low = (int1h < int2h
1418 || (int1h == int2h && int1l < int2l));
1420 if (low == (code == MIN_EXPR))
1421 low = int1l, hi = int1h;
1423 low = int2l, hi = int2h;
1430 t = build_int_cst_wide (TREE_TYPE (arg1), low, hi);
1434 /* Propagate overflow flags ourselves. */
1435 if (((!uns || is_sizetype) && overflow)
1436 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2))
1439 TREE_OVERFLOW (t) = 1;
1440 TREE_CONSTANT_OVERFLOW (t) = 1;
1442 else if (TREE_CONSTANT_OVERFLOW (arg1) | TREE_CONSTANT_OVERFLOW (arg2))
1445 TREE_CONSTANT_OVERFLOW (t) = 1;
1449 t = force_fit_type (t, 1,
1450 ((!uns || is_sizetype) && overflow)
1451 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2),
1452 TREE_CONSTANT_OVERFLOW (arg1)
1453 | TREE_CONSTANT_OVERFLOW (arg2));
1458 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1459 constant. We assume ARG1 and ARG2 have the same data type, or at least
1460 are the same kind of constant and the same machine mode.
1462 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1465 const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1470 if (TREE_CODE (arg1) == INTEGER_CST)
1471 return int_const_binop (code, arg1, arg2, notrunc);
1473 if (TREE_CODE (arg1) == REAL_CST)
1475 enum machine_mode mode;
1478 REAL_VALUE_TYPE value;
1481 d1 = TREE_REAL_CST (arg1);
1482 d2 = TREE_REAL_CST (arg2);
1484 type = TREE_TYPE (arg1);
1485 mode = TYPE_MODE (type);
1487 /* Don't perform operation if we honor signaling NaNs and
1488 either operand is a NaN. */
1489 if (HONOR_SNANS (mode)
1490 && (REAL_VALUE_ISNAN (d1) || REAL_VALUE_ISNAN (d2)))
1493 /* Don't perform operation if it would raise a division
1494 by zero exception. */
1495 if (code == RDIV_EXPR
1496 && REAL_VALUES_EQUAL (d2, dconst0)
1497 && (flag_trapping_math || ! MODE_HAS_INFINITIES (mode)))
1500 /* If either operand is a NaN, just return it. Otherwise, set up
1501 for floating-point trap; we return an overflow. */
1502 if (REAL_VALUE_ISNAN (d1))
1504 else if (REAL_VALUE_ISNAN (d2))
1507 REAL_ARITHMETIC (value, code, d1, d2);
1509 t = build_real (type, real_value_truncate (mode, value));
1511 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2);
1512 TREE_CONSTANT_OVERFLOW (t)
1514 | TREE_CONSTANT_OVERFLOW (arg1)
1515 | TREE_CONSTANT_OVERFLOW (arg2);
1518 if (TREE_CODE (arg1) == COMPLEX_CST)
1520 tree type = TREE_TYPE (arg1);
1521 tree r1 = TREE_REALPART (arg1);
1522 tree i1 = TREE_IMAGPART (arg1);
1523 tree r2 = TREE_REALPART (arg2);
1524 tree i2 = TREE_IMAGPART (arg2);
1530 t = build_complex (type,
1531 const_binop (PLUS_EXPR, r1, r2, notrunc),
1532 const_binop (PLUS_EXPR, i1, i2, notrunc));
1536 t = build_complex (type,
1537 const_binop (MINUS_EXPR, r1, r2, notrunc),
1538 const_binop (MINUS_EXPR, i1, i2, notrunc));
1542 t = build_complex (type,
1543 const_binop (MINUS_EXPR,
1544 const_binop (MULT_EXPR,
1546 const_binop (MULT_EXPR,
1549 const_binop (PLUS_EXPR,
1550 const_binop (MULT_EXPR,
1552 const_binop (MULT_EXPR,
1560 = const_binop (PLUS_EXPR,
1561 const_binop (MULT_EXPR, r2, r2, notrunc),
1562 const_binop (MULT_EXPR, i2, i2, notrunc),
1565 t = build_complex (type,
1567 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1568 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1569 const_binop (PLUS_EXPR,
1570 const_binop (MULT_EXPR, r1, r2,
1572 const_binop (MULT_EXPR, i1, i2,
1575 magsquared, notrunc),
1577 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1578 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1579 const_binop (MINUS_EXPR,
1580 const_binop (MULT_EXPR, i1, r2,
1582 const_binop (MULT_EXPR, r1, i2,
1585 magsquared, notrunc));
1597 /* Create a size type INT_CST node with NUMBER sign extended. KIND
1598 indicates which particular sizetype to create. */
1601 size_int_kind (HOST_WIDE_INT number, enum size_type_kind kind)
1603 return build_int_cst (sizetype_tab[(int) kind], number);
1606 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1607 is a tree code. The type of the result is taken from the operands.
1608 Both must be the same type integer type and it must be a size type.
1609 If the operands are constant, so is the result. */
1612 size_binop (enum tree_code code, tree arg0, tree arg1)
1614 tree type = TREE_TYPE (arg0);
1616 gcc_assert (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type)
1617 && type == TREE_TYPE (arg1));
1619 /* Handle the special case of two integer constants faster. */
1620 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1622 /* And some specific cases even faster than that. */
1623 if (code == PLUS_EXPR && integer_zerop (arg0))
1625 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1626 && integer_zerop (arg1))
1628 else if (code == MULT_EXPR && integer_onep (arg0))
1631 /* Handle general case of two integer constants. */
1632 return int_const_binop (code, arg0, arg1, 0);
1635 if (arg0 == error_mark_node || arg1 == error_mark_node)
1636 return error_mark_node;
1638 return fold (build2 (code, type, arg0, arg1));
1641 /* Given two values, either both of sizetype or both of bitsizetype,
1642 compute the difference between the two values. Return the value
1643 in signed type corresponding to the type of the operands. */
1646 size_diffop (tree arg0, tree arg1)
1648 tree type = TREE_TYPE (arg0);
1651 gcc_assert (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type)
1652 && type == TREE_TYPE (arg1));
1654 /* If the type is already signed, just do the simple thing. */
1655 if (!TYPE_UNSIGNED (type))
1656 return size_binop (MINUS_EXPR, arg0, arg1);
1658 ctype = type == bitsizetype ? sbitsizetype : ssizetype;
1660 /* If either operand is not a constant, do the conversions to the signed
1661 type and subtract. The hardware will do the right thing with any
1662 overflow in the subtraction. */
1663 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
1664 return size_binop (MINUS_EXPR, fold_convert (ctype, arg0),
1665 fold_convert (ctype, arg1));
1667 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
1668 Otherwise, subtract the other way, convert to CTYPE (we know that can't
1669 overflow) and negate (which can't either). Special-case a result
1670 of zero while we're here. */
1671 if (tree_int_cst_equal (arg0, arg1))
1672 return fold_convert (ctype, integer_zero_node);
1673 else if (tree_int_cst_lt (arg1, arg0))
1674 return fold_convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
1676 return size_binop (MINUS_EXPR, fold_convert (ctype, integer_zero_node),
1677 fold_convert (ctype, size_binop (MINUS_EXPR,
1681 /* Construct a vector of zero elements of vector type TYPE. */
1684 build_zero_vector (tree type)
1689 elem = fold_convert_const (NOP_EXPR, TREE_TYPE (type), integer_zero_node);
1690 units = TYPE_VECTOR_SUBPARTS (type);
1693 for (i = 0; i < units; i++)
1694 list = tree_cons (NULL_TREE, elem, list);
1695 return build_vector (type, list);
1699 /* Attempt to fold type conversion operation CODE of expression ARG1 to
1700 type TYPE. If no simplification can be done return NULL_TREE. */
1703 fold_convert_const (enum tree_code code, tree type, tree arg1)
1708 if (TREE_TYPE (arg1) == type)
1711 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
1713 if (TREE_CODE (arg1) == INTEGER_CST)
1715 /* If we would build a constant wider than GCC supports,
1716 leave the conversion unfolded. */
1717 if (TYPE_PRECISION (type) > 2 * HOST_BITS_PER_WIDE_INT)
1720 /* Given an integer constant, make new constant with new type,
1721 appropriately sign-extended or truncated. */
1722 t = build_int_cst_wide (type, TREE_INT_CST_LOW (arg1),
1723 TREE_INT_CST_HIGH (arg1));
1725 t = force_fit_type (t,
1726 /* Don't set the overflow when
1727 converting a pointer */
1728 !POINTER_TYPE_P (TREE_TYPE (arg1)),
1729 (TREE_INT_CST_HIGH (arg1) < 0
1730 && (TYPE_UNSIGNED (type)
1731 < TYPE_UNSIGNED (TREE_TYPE (arg1))))
1732 | TREE_OVERFLOW (arg1),
1733 TREE_CONSTANT_OVERFLOW (arg1));
1736 else if (TREE_CODE (arg1) == REAL_CST)
1738 /* The following code implements the floating point to integer
1739 conversion rules required by the Java Language Specification,
1740 that IEEE NaNs are mapped to zero and values that overflow
1741 the target precision saturate, i.e. values greater than
1742 INT_MAX are mapped to INT_MAX, and values less than INT_MIN
1743 are mapped to INT_MIN. These semantics are allowed by the
1744 C and C++ standards that simply state that the behavior of
1745 FP-to-integer conversion is unspecified upon overflow. */
1747 HOST_WIDE_INT high, low;
1749 REAL_VALUE_TYPE x = TREE_REAL_CST (arg1);
1753 case FIX_TRUNC_EXPR:
1754 real_trunc (&r, VOIDmode, &x);
1758 real_ceil (&r, VOIDmode, &x);
1761 case FIX_FLOOR_EXPR:
1762 real_floor (&r, VOIDmode, &x);
1765 case FIX_ROUND_EXPR:
1766 real_round (&r, VOIDmode, &x);
1773 /* If R is NaN, return zero and show we have an overflow. */
1774 if (REAL_VALUE_ISNAN (r))
1781 /* See if R is less than the lower bound or greater than the
1786 tree lt = TYPE_MIN_VALUE (type);
1787 REAL_VALUE_TYPE l = real_value_from_int_cst (NULL_TREE, lt);
1788 if (REAL_VALUES_LESS (r, l))
1791 high = TREE_INT_CST_HIGH (lt);
1792 low = TREE_INT_CST_LOW (lt);
1798 tree ut = TYPE_MAX_VALUE (type);
1801 REAL_VALUE_TYPE u = real_value_from_int_cst (NULL_TREE, ut);
1802 if (REAL_VALUES_LESS (u, r))
1805 high = TREE_INT_CST_HIGH (ut);
1806 low = TREE_INT_CST_LOW (ut);
1812 REAL_VALUE_TO_INT (&low, &high, r);
1814 t = build_int_cst_wide (type, low, high);
1816 t = force_fit_type (t, -1, overflow | TREE_OVERFLOW (arg1),
1817 TREE_CONSTANT_OVERFLOW (arg1));
1821 else if (TREE_CODE (type) == REAL_TYPE)
1823 if (TREE_CODE (arg1) == INTEGER_CST)
1824 return build_real_from_int_cst (type, arg1);
1825 if (TREE_CODE (arg1) == REAL_CST)
1827 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
1829 /* We make a copy of ARG1 so that we don't modify an
1830 existing constant tree. */
1831 t = copy_node (arg1);
1832 TREE_TYPE (t) = type;
1836 t = build_real (type,
1837 real_value_truncate (TYPE_MODE (type),
1838 TREE_REAL_CST (arg1)));
1840 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1);
1841 TREE_CONSTANT_OVERFLOW (t)
1842 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1849 /* Convert expression ARG to type TYPE. Used by the middle-end for
1850 simple conversions in preference to calling the front-end's convert. */
1853 fold_convert (tree type, tree arg)
1855 tree orig = TREE_TYPE (arg);
1861 if (TREE_CODE (arg) == ERROR_MARK
1862 || TREE_CODE (type) == ERROR_MARK
1863 || TREE_CODE (orig) == ERROR_MARK)
1864 return error_mark_node;
1866 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig)
1867 || lang_hooks.types_compatible_p (TYPE_MAIN_VARIANT (type),
1868 TYPE_MAIN_VARIANT (orig)))
1869 return fold (build1 (NOP_EXPR, type, arg));
1871 switch (TREE_CODE (type))
1873 case INTEGER_TYPE: case CHAR_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
1874 case POINTER_TYPE: case REFERENCE_TYPE:
1876 if (TREE_CODE (arg) == INTEGER_CST)
1878 tem = fold_convert_const (NOP_EXPR, type, arg);
1879 if (tem != NULL_TREE)
1882 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
1883 || TREE_CODE (orig) == OFFSET_TYPE)
1884 return fold (build1 (NOP_EXPR, type, arg));
1885 if (TREE_CODE (orig) == COMPLEX_TYPE)
1887 tem = fold (build1 (REALPART_EXPR, TREE_TYPE (orig), arg));
1888 return fold_convert (type, tem);
1890 gcc_assert (TREE_CODE (orig) == VECTOR_TYPE
1891 && tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
1892 return fold (build1 (NOP_EXPR, type, arg));
1895 if (TREE_CODE (arg) == INTEGER_CST)
1897 tem = fold_convert_const (FLOAT_EXPR, type, arg);
1898 if (tem != NULL_TREE)
1901 else if (TREE_CODE (arg) == REAL_CST)
1903 tem = fold_convert_const (NOP_EXPR, type, arg);
1904 if (tem != NULL_TREE)
1908 switch (TREE_CODE (orig))
1910 case INTEGER_TYPE: case CHAR_TYPE:
1911 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
1912 case POINTER_TYPE: case REFERENCE_TYPE:
1913 return fold (build1 (FLOAT_EXPR, type, arg));
1916 return fold (build1 (flag_float_store ? CONVERT_EXPR : NOP_EXPR,
1920 tem = fold (build1 (REALPART_EXPR, TREE_TYPE (orig), arg));
1921 return fold_convert (type, tem);
1928 switch (TREE_CODE (orig))
1930 case INTEGER_TYPE: case CHAR_TYPE:
1931 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
1932 case POINTER_TYPE: case REFERENCE_TYPE:
1934 return build2 (COMPLEX_EXPR, type,
1935 fold_convert (TREE_TYPE (type), arg),
1936 fold_convert (TREE_TYPE (type), integer_zero_node));
1941 if (TREE_CODE (arg) == COMPLEX_EXPR)
1943 rpart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 0));
1944 ipart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 1));
1945 return fold (build2 (COMPLEX_EXPR, type, rpart, ipart));
1948 arg = save_expr (arg);
1949 rpart = fold (build1 (REALPART_EXPR, TREE_TYPE (orig), arg));
1950 ipart = fold (build1 (IMAGPART_EXPR, TREE_TYPE (orig), arg));
1951 rpart = fold_convert (TREE_TYPE (type), rpart);
1952 ipart = fold_convert (TREE_TYPE (type), ipart);
1953 return fold (build2 (COMPLEX_EXPR, type, rpart, ipart));
1961 if (integer_zerop (arg))
1962 return build_zero_vector (type);
1963 gcc_assert (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
1964 gcc_assert (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
1965 || TREE_CODE (orig) == VECTOR_TYPE);
1966 return fold (build1 (NOP_EXPR, type, arg));
1969 return fold (build1 (CONVERT_EXPR, type, fold_ignored_result (arg)));
1976 /* Return an expr equal to X but certainly not valid as an lvalue. */
1981 /* We only need to wrap lvalue tree codes. */
1982 switch (TREE_CODE (x))
1994 case ARRAY_RANGE_REF:
2000 case PREINCREMENT_EXPR:
2001 case PREDECREMENT_EXPR:
2003 case TRY_CATCH_EXPR:
2004 case WITH_CLEANUP_EXPR:
2015 /* Assume the worst for front-end tree codes. */
2016 if ((int)TREE_CODE (x) >= NUM_TREE_CODES)
2020 return build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
2023 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
2024 Zero means allow extended lvalues. */
2026 int pedantic_lvalues;
2028 /* When pedantic, return an expr equal to X but certainly not valid as a
2029 pedantic lvalue. Otherwise, return X. */
2032 pedantic_non_lvalue (tree x)
2034 if (pedantic_lvalues)
2035 return non_lvalue (x);
2040 /* Given a tree comparison code, return the code that is the logical inverse
2041 of the given code. It is not safe to do this for floating-point
2042 comparisons, except for NE_EXPR and EQ_EXPR, so we receive a machine mode
2043 as well: if reversing the comparison is unsafe, return ERROR_MARK. */
2045 static enum tree_code
2046 invert_tree_comparison (enum tree_code code, bool honor_nans)
2048 if (honor_nans && flag_trapping_math)
2058 return honor_nans ? UNLE_EXPR : LE_EXPR;
2060 return honor_nans ? UNLT_EXPR : LT_EXPR;
2062 return honor_nans ? UNGE_EXPR : GE_EXPR;
2064 return honor_nans ? UNGT_EXPR : GT_EXPR;
2078 return UNORDERED_EXPR;
2079 case UNORDERED_EXPR:
2080 return ORDERED_EXPR;
2086 /* Similar, but return the comparison that results if the operands are
2087 swapped. This is safe for floating-point. */
2090 swap_tree_comparison (enum tree_code code)
2111 /* Convert a comparison tree code from an enum tree_code representation
2112 into a compcode bit-based encoding. This function is the inverse of
2113 compcode_to_comparison. */
2115 static enum comparison_code
2116 comparison_to_compcode (enum tree_code code)
2133 return COMPCODE_ORD;
2134 case UNORDERED_EXPR:
2135 return COMPCODE_UNORD;
2137 return COMPCODE_UNLT;
2139 return COMPCODE_UNEQ;
2141 return COMPCODE_UNLE;
2143 return COMPCODE_UNGT;
2145 return COMPCODE_LTGT;
2147 return COMPCODE_UNGE;
2153 /* Convert a compcode bit-based encoding of a comparison operator back
2154 to GCC's enum tree_code representation. This function is the
2155 inverse of comparison_to_compcode. */
2157 static enum tree_code
2158 compcode_to_comparison (enum comparison_code code)
2175 return ORDERED_EXPR;
2176 case COMPCODE_UNORD:
2177 return UNORDERED_EXPR;
2195 /* Return a tree for the comparison which is the combination of
2196 doing the AND or OR (depending on CODE) of the two operations LCODE
2197 and RCODE on the identical operands LL_ARG and LR_ARG. Take into account
2198 the possibility of trapping if the mode has NaNs, and return NULL_TREE
2199 if this makes the transformation invalid. */
2202 combine_comparisons (enum tree_code code, enum tree_code lcode,
2203 enum tree_code rcode, tree truth_type,
2204 tree ll_arg, tree lr_arg)
2206 bool honor_nans = HONOR_NANS (TYPE_MODE (TREE_TYPE (ll_arg)));
2207 enum comparison_code lcompcode = comparison_to_compcode (lcode);
2208 enum comparison_code rcompcode = comparison_to_compcode (rcode);
2209 enum comparison_code compcode;
2213 case TRUTH_AND_EXPR: case TRUTH_ANDIF_EXPR:
2214 compcode = lcompcode & rcompcode;
2217 case TRUTH_OR_EXPR: case TRUTH_ORIF_EXPR:
2218 compcode = lcompcode | rcompcode;
2227 /* Eliminate unordered comparisons, as well as LTGT and ORD
2228 which are not used unless the mode has NaNs. */
2229 compcode &= ~COMPCODE_UNORD;
2230 if (compcode == COMPCODE_LTGT)
2231 compcode = COMPCODE_NE;
2232 else if (compcode == COMPCODE_ORD)
2233 compcode = COMPCODE_TRUE;
2235 else if (flag_trapping_math)
2237 /* Check that the original operation and the optimized ones will trap
2238 under the same condition. */
2239 bool ltrap = (lcompcode & COMPCODE_UNORD) == 0
2240 && (lcompcode != COMPCODE_EQ)
2241 && (lcompcode != COMPCODE_ORD);
2242 bool rtrap = (rcompcode & COMPCODE_UNORD) == 0
2243 && (rcompcode != COMPCODE_EQ)
2244 && (rcompcode != COMPCODE_ORD);
2245 bool trap = (compcode & COMPCODE_UNORD) == 0
2246 && (compcode != COMPCODE_EQ)
2247 && (compcode != COMPCODE_ORD);
2249 /* In a short-circuited boolean expression the LHS might be
2250 such that the RHS, if evaluated, will never trap. For
2251 example, in ORD (x, y) && (x < y), we evaluate the RHS only
2252 if neither x nor y is NaN. (This is a mixed blessing: for
2253 example, the expression above will never trap, hence
2254 optimizing it to x < y would be invalid). */
2255 if ((code == TRUTH_ORIF_EXPR && (lcompcode & COMPCODE_UNORD))
2256 || (code == TRUTH_ANDIF_EXPR && !(lcompcode & COMPCODE_UNORD)))
2259 /* If the comparison was short-circuited, and only the RHS
2260 trapped, we may now generate a spurious trap. */
2262 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2265 /* If we changed the conditions that cause a trap, we lose. */
2266 if ((ltrap || rtrap) != trap)
2270 if (compcode == COMPCODE_TRUE)
2271 return constant_boolean_node (true, truth_type);
2272 else if (compcode == COMPCODE_FALSE)
2273 return constant_boolean_node (false, truth_type);
2275 return fold (build2 (compcode_to_comparison (compcode),
2276 truth_type, ll_arg, lr_arg));
2279 /* Return nonzero if CODE is a tree code that represents a truth value. */
2282 truth_value_p (enum tree_code code)
2284 return (TREE_CODE_CLASS (code) == '<'
2285 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2286 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2287 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
2290 /* Return nonzero if two operands (typically of the same tree node)
2291 are necessarily equal. If either argument has side-effects this
2292 function returns zero. FLAGS modifies behavior as follows:
2294 If OEP_ONLY_CONST is set, only return nonzero for constants.
2295 This function tests whether the operands are indistinguishable;
2296 it does not test whether they are equal using C's == operation.
2297 The distinction is important for IEEE floating point, because
2298 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2299 (2) two NaNs may be indistinguishable, but NaN!=NaN.
2301 If OEP_ONLY_CONST is unset, a VAR_DECL is considered equal to itself
2302 even though it may hold multiple values during a function.
2303 This is because a GCC tree node guarantees that nothing else is
2304 executed between the evaluation of its "operands" (which may often
2305 be evaluated in arbitrary order). Hence if the operands themselves
2306 don't side-effect, the VAR_DECLs, PARM_DECLs etc... must hold the
2307 same value in each operand/subexpression. Hence leaving OEP_ONLY_CONST
2308 unset means assuming isochronic (or instantaneous) tree equivalence.
2309 Unless comparing arbitrary expression trees, such as from different
2310 statements, this flag can usually be left unset.
2312 If OEP_PURE_SAME is set, then pure functions with identical arguments
2313 are considered the same. It is used when the caller has other ways
2314 to ensure that global memory is unchanged in between. */
2317 operand_equal_p (tree arg0, tree arg1, unsigned int flags)
2319 /* If one is specified and the other isn't, they aren't equal and if
2320 neither is specified, they are.
2322 ??? This is temporary and is meant only to handle the cases of the
2323 optional operands for COMPONENT_REF and ARRAY_REF. */
2324 if ((arg0 && !arg1) || (!arg0 && arg1))
2326 else if (!arg0 && !arg1)
2328 /* If either is ERROR_MARK, they aren't equal. */
2329 else if (TREE_CODE (arg0) == ERROR_MARK || TREE_CODE (arg1) == ERROR_MARK)
2332 /* If both types don't have the same signedness, then we can't consider
2333 them equal. We must check this before the STRIP_NOPS calls
2334 because they may change the signedness of the arguments. */
2335 if (TYPE_UNSIGNED (TREE_TYPE (arg0)) != TYPE_UNSIGNED (TREE_TYPE (arg1)))
2341 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2342 /* This is needed for conversions and for COMPONENT_REF.
2343 Might as well play it safe and always test this. */
2344 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
2345 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
2346 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
2349 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
2350 We don't care about side effects in that case because the SAVE_EXPR
2351 takes care of that for us. In all other cases, two expressions are
2352 equal if they have no side effects. If we have two identical
2353 expressions with side effects that should be treated the same due
2354 to the only side effects being identical SAVE_EXPR's, that will
2355 be detected in the recursive calls below. */
2356 if (arg0 == arg1 && ! (flags & OEP_ONLY_CONST)
2357 && (TREE_CODE (arg0) == SAVE_EXPR
2358 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
2361 /* Next handle constant cases, those for which we can return 1 even
2362 if ONLY_CONST is set. */
2363 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
2364 switch (TREE_CODE (arg0))
2367 return (! TREE_CONSTANT_OVERFLOW (arg0)
2368 && ! TREE_CONSTANT_OVERFLOW (arg1)
2369 && tree_int_cst_equal (arg0, arg1));
2372 return (! TREE_CONSTANT_OVERFLOW (arg0)
2373 && ! TREE_CONSTANT_OVERFLOW (arg1)
2374 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
2375 TREE_REAL_CST (arg1)));
2381 if (TREE_CONSTANT_OVERFLOW (arg0)
2382 || TREE_CONSTANT_OVERFLOW (arg1))
2385 v1 = TREE_VECTOR_CST_ELTS (arg0);
2386 v2 = TREE_VECTOR_CST_ELTS (arg1);
2389 if (!operand_equal_p (TREE_VALUE (v1), TREE_VALUE (v2),
2392 v1 = TREE_CHAIN (v1);
2393 v2 = TREE_CHAIN (v2);
2400 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
2402 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
2406 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
2407 && ! memcmp (TREE_STRING_POINTER (arg0),
2408 TREE_STRING_POINTER (arg1),
2409 TREE_STRING_LENGTH (arg0)));
2412 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
2418 if (flags & OEP_ONLY_CONST)
2421 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
2424 /* Two conversions are equal only if signedness and modes match. */
2425 switch (TREE_CODE (arg0))
2430 case FIX_TRUNC_EXPR:
2431 case FIX_FLOOR_EXPR:
2432 case FIX_ROUND_EXPR:
2433 if (TYPE_UNSIGNED (TREE_TYPE (arg0))
2434 != TYPE_UNSIGNED (TREE_TYPE (arg1)))
2441 return operand_equal_p (TREE_OPERAND (arg0, 0),
2442 TREE_OPERAND (arg1, 0), flags);
2446 if (operand_equal_p (TREE_OPERAND (arg0, 0),
2447 TREE_OPERAND (arg1, 0), flags)
2448 && operand_equal_p (TREE_OPERAND (arg0, 1),
2449 TREE_OPERAND (arg1, 1), flags))
2452 /* For commutative ops, allow the other order. */
2453 return (commutative_tree_code (TREE_CODE (arg0))
2454 && operand_equal_p (TREE_OPERAND (arg0, 0),
2455 TREE_OPERAND (arg1, 1), flags)
2456 && operand_equal_p (TREE_OPERAND (arg0, 1),
2457 TREE_OPERAND (arg1, 0), flags));
2460 /* If either of the pointer (or reference) expressions we are
2461 dereferencing contain a side effect, these cannot be equal. */
2462 if (TREE_SIDE_EFFECTS (arg0)
2463 || TREE_SIDE_EFFECTS (arg1))
2466 switch (TREE_CODE (arg0))
2471 return operand_equal_p (TREE_OPERAND (arg0, 0),
2472 TREE_OPERAND (arg1, 0), flags);
2475 case ARRAY_RANGE_REF:
2476 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2477 TREE_OPERAND (arg1, 0), flags)
2478 && operand_equal_p (TREE_OPERAND (arg0, 1),
2479 TREE_OPERAND (arg1, 1), flags)
2480 && operand_equal_p (TREE_OPERAND (arg0, 2),
2481 TREE_OPERAND (arg1, 2), flags)
2482 && operand_equal_p (TREE_OPERAND (arg0, 3),
2483 TREE_OPERAND (arg1, 3), flags));
2487 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2488 TREE_OPERAND (arg1, 0), flags)
2489 && operand_equal_p (TREE_OPERAND (arg0, 1),
2490 TREE_OPERAND (arg1, 1), flags)
2491 && operand_equal_p (TREE_OPERAND (arg0, 2),
2492 TREE_OPERAND (arg1, 2), flags));
2496 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2497 TREE_OPERAND (arg1, 0), flags)
2498 && operand_equal_p (TREE_OPERAND (arg0, 1),
2499 TREE_OPERAND (arg1, 1), flags)
2500 && operand_equal_p (TREE_OPERAND (arg0, 2),
2501 TREE_OPERAND (arg1, 2), flags));
2507 switch (TREE_CODE (arg0))
2510 case TRUTH_NOT_EXPR:
2511 return operand_equal_p (TREE_OPERAND (arg0, 0),
2512 TREE_OPERAND (arg1, 0), flags);
2514 case TRUTH_ANDIF_EXPR:
2515 case TRUTH_ORIF_EXPR:
2516 return operand_equal_p (TREE_OPERAND (arg0, 0),
2517 TREE_OPERAND (arg1, 0), flags)
2518 && operand_equal_p (TREE_OPERAND (arg0, 1),
2519 TREE_OPERAND (arg1, 1), flags);
2521 case TRUTH_AND_EXPR:
2523 case TRUTH_XOR_EXPR:
2524 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2525 TREE_OPERAND (arg1, 0), flags)
2526 && operand_equal_p (TREE_OPERAND (arg0, 1),
2527 TREE_OPERAND (arg1, 1), flags))
2528 || (operand_equal_p (TREE_OPERAND (arg0, 0),
2529 TREE_OPERAND (arg1, 1), flags)
2530 && operand_equal_p (TREE_OPERAND (arg0, 1),
2531 TREE_OPERAND (arg1, 0), flags));
2534 /* If the CALL_EXPRs call different functions, then they
2535 clearly can not be equal. */
2536 if (! operand_equal_p (TREE_OPERAND (arg0, 0),
2537 TREE_OPERAND (arg1, 0), flags))
2541 unsigned int cef = call_expr_flags (arg0);
2542 if (flags & OEP_PURE_SAME)
2543 cef &= ECF_CONST | ECF_PURE;
2550 /* Now see if all the arguments are the same. operand_equal_p
2551 does not handle TREE_LIST, so we walk the operands here
2552 feeding them to operand_equal_p. */
2553 arg0 = TREE_OPERAND (arg0, 1);
2554 arg1 = TREE_OPERAND (arg1, 1);
2555 while (arg0 && arg1)
2557 if (! operand_equal_p (TREE_VALUE (arg0), TREE_VALUE (arg1),
2561 arg0 = TREE_CHAIN (arg0);
2562 arg1 = TREE_CHAIN (arg1);
2565 /* If we get here and both argument lists are exhausted
2566 then the CALL_EXPRs are equal. */
2567 return ! (arg0 || arg1);
2574 /* Consider __builtin_sqrt equal to sqrt. */
2575 return (TREE_CODE (arg0) == FUNCTION_DECL
2576 && DECL_BUILT_IN (arg0) && DECL_BUILT_IN (arg1)
2577 && DECL_BUILT_IN_CLASS (arg0) == DECL_BUILT_IN_CLASS (arg1)
2578 && DECL_FUNCTION_CODE (arg0) == DECL_FUNCTION_CODE (arg1));
2585 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2586 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2588 When in doubt, return 0. */
2591 operand_equal_for_comparison_p (tree arg0, tree arg1, tree other)
2593 int unsignedp1, unsignedpo;
2594 tree primarg0, primarg1, primother;
2595 unsigned int correct_width;
2597 if (operand_equal_p (arg0, arg1, 0))
2600 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
2601 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
2604 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2605 and see if the inner values are the same. This removes any
2606 signedness comparison, which doesn't matter here. */
2607 primarg0 = arg0, primarg1 = arg1;
2608 STRIP_NOPS (primarg0);
2609 STRIP_NOPS (primarg1);
2610 if (operand_equal_p (primarg0, primarg1, 0))
2613 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2614 actual comparison operand, ARG0.
2616 First throw away any conversions to wider types
2617 already present in the operands. */
2619 primarg1 = get_narrower (arg1, &unsignedp1);
2620 primother = get_narrower (other, &unsignedpo);
2622 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
2623 if (unsignedp1 == unsignedpo
2624 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
2625 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
2627 tree type = TREE_TYPE (arg0);
2629 /* Make sure shorter operand is extended the right way
2630 to match the longer operand. */
2631 primarg1 = fold_convert (lang_hooks.types.signed_or_unsigned_type
2632 (unsignedp1, TREE_TYPE (primarg1)), primarg1);
2634 if (operand_equal_p (arg0, fold_convert (type, primarg1), 0))
2641 /* See if ARG is an expression that is either a comparison or is performing
2642 arithmetic on comparisons. The comparisons must only be comparing
2643 two different values, which will be stored in *CVAL1 and *CVAL2; if
2644 they are nonzero it means that some operands have already been found.
2645 No variables may be used anywhere else in the expression except in the
2646 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2647 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2649 If this is true, return 1. Otherwise, return zero. */
2652 twoval_comparison_p (tree arg, tree *cval1, tree *cval2, int *save_p)
2654 enum tree_code code = TREE_CODE (arg);
2655 char class = TREE_CODE_CLASS (code);
2657 /* We can handle some of the 'e' cases here. */
2658 if (class == 'e' && code == TRUTH_NOT_EXPR)
2660 else if (class == 'e'
2661 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
2662 || code == COMPOUND_EXPR))
2665 else if (class == 'e' && code == SAVE_EXPR
2666 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
2668 /* If we've already found a CVAL1 or CVAL2, this expression is
2669 two complex to handle. */
2670 if (*cval1 || *cval2)
2680 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
2683 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
2684 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2685 cval1, cval2, save_p));
2691 if (code == COND_EXPR)
2692 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
2693 cval1, cval2, save_p)
2694 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2695 cval1, cval2, save_p)
2696 && twoval_comparison_p (TREE_OPERAND (arg, 2),
2697 cval1, cval2, save_p));
2701 /* First see if we can handle the first operand, then the second. For
2702 the second operand, we know *CVAL1 can't be zero. It must be that
2703 one side of the comparison is each of the values; test for the
2704 case where this isn't true by failing if the two operands
2707 if (operand_equal_p (TREE_OPERAND (arg, 0),
2708 TREE_OPERAND (arg, 1), 0))
2712 *cval1 = TREE_OPERAND (arg, 0);
2713 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
2715 else if (*cval2 == 0)
2716 *cval2 = TREE_OPERAND (arg, 0);
2717 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
2722 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
2724 else if (*cval2 == 0)
2725 *cval2 = TREE_OPERAND (arg, 1);
2726 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
2738 /* ARG is a tree that is known to contain just arithmetic operations and
2739 comparisons. Evaluate the operations in the tree substituting NEW0 for
2740 any occurrence of OLD0 as an operand of a comparison and likewise for
2744 eval_subst (tree arg, tree old0, tree new0, tree old1, tree new1)
2746 tree type = TREE_TYPE (arg);
2747 enum tree_code code = TREE_CODE (arg);
2748 char class = TREE_CODE_CLASS (code);
2750 /* We can handle some of the 'e' cases here. */
2751 if (class == 'e' && code == TRUTH_NOT_EXPR)
2753 else if (class == 'e'
2754 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2760 return fold (build1 (code, type,
2761 eval_subst (TREE_OPERAND (arg, 0),
2762 old0, new0, old1, new1)));
2765 return fold (build2 (code, type,
2766 eval_subst (TREE_OPERAND (arg, 0),
2767 old0, new0, old1, new1),
2768 eval_subst (TREE_OPERAND (arg, 1),
2769 old0, new0, old1, new1)));
2775 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
2778 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
2781 return fold (build3 (code, type,
2782 eval_subst (TREE_OPERAND (arg, 0),
2783 old0, new0, old1, new1),
2784 eval_subst (TREE_OPERAND (arg, 1),
2785 old0, new0, old1, new1),
2786 eval_subst (TREE_OPERAND (arg, 2),
2787 old0, new0, old1, new1)));
2791 /* Fall through - ??? */
2795 tree arg0 = TREE_OPERAND (arg, 0);
2796 tree arg1 = TREE_OPERAND (arg, 1);
2798 /* We need to check both for exact equality and tree equality. The
2799 former will be true if the operand has a side-effect. In that
2800 case, we know the operand occurred exactly once. */
2802 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
2804 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
2807 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
2809 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
2812 return fold (build2 (code, type, arg0, arg1));
2820 /* Return a tree for the case when the result of an expression is RESULT
2821 converted to TYPE and OMITTED was previously an operand of the expression
2822 but is now not needed (e.g., we folded OMITTED * 0).
2824 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2825 the conversion of RESULT to TYPE. */
2828 omit_one_operand (tree type, tree result, tree omitted)
2830 tree t = fold_convert (type, result);
2832 if (TREE_SIDE_EFFECTS (omitted))
2833 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
2835 return non_lvalue (t);
2838 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2841 pedantic_omit_one_operand (tree type, tree result, tree omitted)
2843 tree t = fold_convert (type, result);
2845 if (TREE_SIDE_EFFECTS (omitted))
2846 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
2848 return pedantic_non_lvalue (t);
2851 /* Return a tree for the case when the result of an expression is RESULT
2852 converted to TYPE and OMITTED1 and OMITTED2 were previously operands
2853 of the expression but are now not needed.
2855 If OMITTED1 or OMITTED2 has side effects, they must be evaluated.
2856 If both OMITTED1 and OMITTED2 have side effects, OMITTED1 is
2857 evaluated before OMITTED2. Otherwise, if neither has side effects,
2858 just do the conversion of RESULT to TYPE. */
2861 omit_two_operands (tree type, tree result, tree omitted1, tree omitted2)
2863 tree t = fold_convert (type, result);
2865 if (TREE_SIDE_EFFECTS (omitted2))
2866 t = build2 (COMPOUND_EXPR, type, omitted2, t);
2867 if (TREE_SIDE_EFFECTS (omitted1))
2868 t = build2 (COMPOUND_EXPR, type, omitted1, t);
2870 return TREE_CODE (t) != COMPOUND_EXPR ? non_lvalue (t) : t;
2874 /* Return a simplified tree node for the truth-negation of ARG. This
2875 never alters ARG itself. We assume that ARG is an operation that
2876 returns a truth value (0 or 1).
2878 FIXME: one would think we would fold the result, but it causes
2879 problems with the dominator optimizer. */
2881 invert_truthvalue (tree arg)
2883 tree type = TREE_TYPE (arg);
2884 enum tree_code code = TREE_CODE (arg);
2886 if (code == ERROR_MARK)
2889 /* If this is a comparison, we can simply invert it, except for
2890 floating-point non-equality comparisons, in which case we just
2891 enclose a TRUTH_NOT_EXPR around what we have. */
2893 if (TREE_CODE_CLASS (code) == '<')
2895 tree op_type = TREE_TYPE (TREE_OPERAND (arg, 0));
2896 if (FLOAT_TYPE_P (op_type)
2897 && flag_trapping_math
2898 && code != ORDERED_EXPR && code != UNORDERED_EXPR
2899 && code != NE_EXPR && code != EQ_EXPR)
2900 return build1 (TRUTH_NOT_EXPR, type, arg);
2903 code = invert_tree_comparison (code,
2904 HONOR_NANS (TYPE_MODE (op_type)));
2905 if (code == ERROR_MARK)
2906 return build1 (TRUTH_NOT_EXPR, type, arg);
2908 return build2 (code, type,
2909 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
2916 return fold_convert (type,
2917 build_int_cst (NULL_TREE, integer_zerop (arg)));
2919 case TRUTH_AND_EXPR:
2920 return build2 (TRUTH_OR_EXPR, type,
2921 invert_truthvalue (TREE_OPERAND (arg, 0)),
2922 invert_truthvalue (TREE_OPERAND (arg, 1)));
2925 return build2 (TRUTH_AND_EXPR, type,
2926 invert_truthvalue (TREE_OPERAND (arg, 0)),
2927 invert_truthvalue (TREE_OPERAND (arg, 1)));
2929 case TRUTH_XOR_EXPR:
2930 /* Here we can invert either operand. We invert the first operand
2931 unless the second operand is a TRUTH_NOT_EXPR in which case our
2932 result is the XOR of the first operand with the inside of the
2933 negation of the second operand. */
2935 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
2936 return build2 (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
2937 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
2939 return build2 (TRUTH_XOR_EXPR, type,
2940 invert_truthvalue (TREE_OPERAND (arg, 0)),
2941 TREE_OPERAND (arg, 1));
2943 case TRUTH_ANDIF_EXPR:
2944 return build2 (TRUTH_ORIF_EXPR, type,
2945 invert_truthvalue (TREE_OPERAND (arg, 0)),
2946 invert_truthvalue (TREE_OPERAND (arg, 1)));
2948 case TRUTH_ORIF_EXPR:
2949 return build2 (TRUTH_ANDIF_EXPR, type,
2950 invert_truthvalue (TREE_OPERAND (arg, 0)),
2951 invert_truthvalue (TREE_OPERAND (arg, 1)));
2953 case TRUTH_NOT_EXPR:
2954 return TREE_OPERAND (arg, 0);
2957 return build3 (COND_EXPR, type, TREE_OPERAND (arg, 0),
2958 invert_truthvalue (TREE_OPERAND (arg, 1)),
2959 invert_truthvalue (TREE_OPERAND (arg, 2)));
2962 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
2963 invert_truthvalue (TREE_OPERAND (arg, 1)));
2965 case NON_LVALUE_EXPR:
2966 return invert_truthvalue (TREE_OPERAND (arg, 0));
2969 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE)
2974 return build1 (TREE_CODE (arg), type,
2975 invert_truthvalue (TREE_OPERAND (arg, 0)));
2978 if (!integer_onep (TREE_OPERAND (arg, 1)))
2980 return build2 (EQ_EXPR, type, arg,
2981 fold_convert (type, integer_zero_node));
2984 return build1 (TRUTH_NOT_EXPR, type, arg);
2986 case CLEANUP_POINT_EXPR:
2987 return build1 (CLEANUP_POINT_EXPR, type,
2988 invert_truthvalue (TREE_OPERAND (arg, 0)));
2993 gcc_assert (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE);
2994 return build1 (TRUTH_NOT_EXPR, type, arg);
2997 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
2998 operands are another bit-wise operation with a common input. If so,
2999 distribute the bit operations to save an operation and possibly two if
3000 constants are involved. For example, convert
3001 (A | B) & (A | C) into A | (B & C)
3002 Further simplification will occur if B and C are constants.
3004 If this optimization cannot be done, 0 will be returned. */
3007 distribute_bit_expr (enum tree_code code, tree type, tree arg0, tree arg1)
3012 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3013 || TREE_CODE (arg0) == code
3014 || (TREE_CODE (arg0) != BIT_AND_EXPR
3015 && TREE_CODE (arg0) != BIT_IOR_EXPR))
3018 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
3020 common = TREE_OPERAND (arg0, 0);
3021 left = TREE_OPERAND (arg0, 1);
3022 right = TREE_OPERAND (arg1, 1);
3024 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
3026 common = TREE_OPERAND (arg0, 0);
3027 left = TREE_OPERAND (arg0, 1);
3028 right = TREE_OPERAND (arg1, 0);
3030 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
3032 common = TREE_OPERAND (arg0, 1);
3033 left = TREE_OPERAND (arg0, 0);
3034 right = TREE_OPERAND (arg1, 1);
3036 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
3038 common = TREE_OPERAND (arg0, 1);
3039 left = TREE_OPERAND (arg0, 0);
3040 right = TREE_OPERAND (arg1, 0);
3045 return fold (build2 (TREE_CODE (arg0), type, common,
3046 fold (build2 (code, type, left, right))));
3049 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
3050 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
3053 make_bit_field_ref (tree inner, tree type, int bitsize, int bitpos,
3056 tree result = build3 (BIT_FIELD_REF, type, inner,
3057 size_int (bitsize), bitsize_int (bitpos));
3059 BIT_FIELD_REF_UNSIGNED (result) = unsignedp;
3064 /* Optimize a bit-field compare.
3066 There are two cases: First is a compare against a constant and the
3067 second is a comparison of two items where the fields are at the same
3068 bit position relative to the start of a chunk (byte, halfword, word)
3069 large enough to contain it. In these cases we can avoid the shift
3070 implicit in bitfield extractions.
3072 For constants, we emit a compare of the shifted constant with the
3073 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
3074 compared. For two fields at the same position, we do the ANDs with the
3075 similar mask and compare the result of the ANDs.
3077 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
3078 COMPARE_TYPE is the type of the comparison, and LHS and RHS
3079 are the left and right operands of the comparison, respectively.
3081 If the optimization described above can be done, we return the resulting
3082 tree. Otherwise we return zero. */
3085 optimize_bit_field_compare (enum tree_code code, tree compare_type,
3088 HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
3089 tree type = TREE_TYPE (lhs);
3090 tree signed_type, unsigned_type;
3091 int const_p = TREE_CODE (rhs) == INTEGER_CST;
3092 enum machine_mode lmode, rmode, nmode;
3093 int lunsignedp, runsignedp;
3094 int lvolatilep = 0, rvolatilep = 0;
3095 tree linner, rinner = NULL_TREE;
3099 /* Get all the information about the extractions being done. If the bit size
3100 if the same as the size of the underlying object, we aren't doing an
3101 extraction at all and so can do nothing. We also don't want to
3102 do anything if the inner expression is a PLACEHOLDER_EXPR since we
3103 then will no longer be able to replace it. */
3104 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
3105 &lunsignedp, &lvolatilep);
3106 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
3107 || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
3112 /* If this is not a constant, we can only do something if bit positions,
3113 sizes, and signedness are the same. */
3114 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
3115 &runsignedp, &rvolatilep);
3117 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
3118 || lunsignedp != runsignedp || offset != 0
3119 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
3123 /* See if we can find a mode to refer to this field. We should be able to,
3124 but fail if we can't. */
3125 nmode = get_best_mode (lbitsize, lbitpos,
3126 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
3127 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
3128 TYPE_ALIGN (TREE_TYPE (rinner))),
3129 word_mode, lvolatilep || rvolatilep);
3130 if (nmode == VOIDmode)
3133 /* Set signed and unsigned types of the precision of this mode for the
3135 signed_type = lang_hooks.types.type_for_mode (nmode, 0);
3136 unsigned_type = lang_hooks.types.type_for_mode (nmode, 1);
3138 /* Compute the bit position and size for the new reference and our offset
3139 within it. If the new reference is the same size as the original, we
3140 won't optimize anything, so return zero. */
3141 nbitsize = GET_MODE_BITSIZE (nmode);
3142 nbitpos = lbitpos & ~ (nbitsize - 1);
3144 if (nbitsize == lbitsize)
3147 if (BYTES_BIG_ENDIAN)
3148 lbitpos = nbitsize - lbitsize - lbitpos;
3150 /* Make the mask to be used against the extracted field. */
3151 mask = build_int_cst (unsigned_type, -1);
3152 mask = force_fit_type (mask, 0, false, false);
3153 mask = fold_convert (unsigned_type, mask);
3154 mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
3155 mask = const_binop (RSHIFT_EXPR, mask,
3156 size_int (nbitsize - lbitsize - lbitpos), 0);
3159 /* If not comparing with constant, just rework the comparison
3161 return build2 (code, compare_type,
3162 build2 (BIT_AND_EXPR, unsigned_type,
3163 make_bit_field_ref (linner, unsigned_type,
3164 nbitsize, nbitpos, 1),
3166 build2 (BIT_AND_EXPR, unsigned_type,
3167 make_bit_field_ref (rinner, unsigned_type,
3168 nbitsize, nbitpos, 1),
3171 /* Otherwise, we are handling the constant case. See if the constant is too
3172 big for the field. Warn and return a tree of for 0 (false) if so. We do
3173 this not only for its own sake, but to avoid having to test for this
3174 error case below. If we didn't, we might generate wrong code.
3176 For unsigned fields, the constant shifted right by the field length should
3177 be all zero. For signed fields, the high-order bits should agree with
3182 if (! integer_zerop (const_binop (RSHIFT_EXPR,
3183 fold_convert (unsigned_type, rhs),
3184 size_int (lbitsize), 0)))
3186 warning ("comparison is always %d due to width of bit-field",
3188 return constant_boolean_node (code == NE_EXPR, compare_type);
3193 tree tem = const_binop (RSHIFT_EXPR, fold_convert (signed_type, rhs),
3194 size_int (lbitsize - 1), 0);
3195 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
3197 warning ("comparison is always %d due to width of bit-field",
3199 return constant_boolean_node (code == NE_EXPR, compare_type);
3203 /* Single-bit compares should always be against zero. */
3204 if (lbitsize == 1 && ! integer_zerop (rhs))
3206 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
3207 rhs = fold_convert (type, integer_zero_node);
3210 /* Make a new bitfield reference, shift the constant over the
3211 appropriate number of bits and mask it with the computed mask
3212 (in case this was a signed field). If we changed it, make a new one. */
3213 lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1);
3216 TREE_SIDE_EFFECTS (lhs) = 1;
3217 TREE_THIS_VOLATILE (lhs) = 1;
3220 rhs = fold (const_binop (BIT_AND_EXPR,
3221 const_binop (LSHIFT_EXPR,
3222 fold_convert (unsigned_type, rhs),
3223 size_int (lbitpos), 0),
3226 return build2 (code, compare_type,
3227 build2 (BIT_AND_EXPR, unsigned_type, lhs, mask),
3231 /* Subroutine for fold_truthop: decode a field reference.
3233 If EXP is a comparison reference, we return the innermost reference.
3235 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
3236 set to the starting bit number.
3238 If the innermost field can be completely contained in a mode-sized
3239 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
3241 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
3242 otherwise it is not changed.
3244 *PUNSIGNEDP is set to the signedness of the field.
3246 *PMASK is set to the mask used. This is either contained in a
3247 BIT_AND_EXPR or derived from the width of the field.
3249 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
3251 Return 0 if this is not a component reference or is one that we can't
3252 do anything with. */
3255 decode_field_reference (tree exp, HOST_WIDE_INT *pbitsize,
3256 HOST_WIDE_INT *pbitpos, enum machine_mode *pmode,
3257 int *punsignedp, int *pvolatilep,
3258 tree *pmask, tree *pand_mask)
3260 tree outer_type = 0;
3262 tree mask, inner, offset;
3264 unsigned int precision;
3266 /* All the optimizations using this function assume integer fields.
3267 There are problems with FP fields since the type_for_size call
3268 below can fail for, e.g., XFmode. */
3269 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
3272 /* We are interested in the bare arrangement of bits, so strip everything
3273 that doesn't affect the machine mode. However, record the type of the
3274 outermost expression if it may matter below. */
3275 if (TREE_CODE (exp) == NOP_EXPR
3276 || TREE_CODE (exp) == CONVERT_EXPR
3277 || TREE_CODE (exp) == NON_LVALUE_EXPR)
3278 outer_type = TREE_TYPE (exp);
3281 if (TREE_CODE (exp) == BIT_AND_EXPR)
3283 and_mask = TREE_OPERAND (exp, 1);
3284 exp = TREE_OPERAND (exp, 0);
3285 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
3286 if (TREE_CODE (and_mask) != INTEGER_CST)
3290 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
3291 punsignedp, pvolatilep);
3292 if ((inner == exp && and_mask == 0)
3293 || *pbitsize < 0 || offset != 0
3294 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
3297 /* If the number of bits in the reference is the same as the bitsize of
3298 the outer type, then the outer type gives the signedness. Otherwise
3299 (in case of a small bitfield) the signedness is unchanged. */
3300 if (outer_type && *pbitsize == TYPE_PRECISION (outer_type))
3301 *punsignedp = TYPE_UNSIGNED (outer_type);
3303 /* Compute the mask to access the bitfield. */
3304 unsigned_type = lang_hooks.types.type_for_size (*pbitsize, 1);
3305 precision = TYPE_PRECISION (unsigned_type);
3307 mask = build_int_cst (unsigned_type, -1);
3308 mask = force_fit_type (mask, 0, false, false);
3310 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3311 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3313 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
3315 mask = fold (build2 (BIT_AND_EXPR, unsigned_type,
3316 fold_convert (unsigned_type, and_mask), mask));
3319 *pand_mask = and_mask;
3323 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
3327 all_ones_mask_p (tree mask, int size)
3329 tree type = TREE_TYPE (mask);
3330 unsigned int precision = TYPE_PRECISION (type);
3333 tmask = build_int_cst (lang_hooks.types.signed_type (type), -1);
3334 tmask = force_fit_type (tmask, 0, false, false);
3337 tree_int_cst_equal (mask,
3338 const_binop (RSHIFT_EXPR,
3339 const_binop (LSHIFT_EXPR, tmask,
3340 size_int (precision - size),
3342 size_int (precision - size), 0));
3345 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
3346 represents the sign bit of EXP's type. If EXP represents a sign
3347 or zero extension, also test VAL against the unextended type.
3348 The return value is the (sub)expression whose sign bit is VAL,
3349 or NULL_TREE otherwise. */
3352 sign_bit_p (tree exp, tree val)
3354 unsigned HOST_WIDE_INT mask_lo, lo;
3355 HOST_WIDE_INT mask_hi, hi;
3359 /* Tree EXP must have an integral type. */
3360 t = TREE_TYPE (exp);
3361 if (! INTEGRAL_TYPE_P (t))
3364 /* Tree VAL must be an integer constant. */
3365 if (TREE_CODE (val) != INTEGER_CST
3366 || TREE_CONSTANT_OVERFLOW (val))
3369 width = TYPE_PRECISION (t);
3370 if (width > HOST_BITS_PER_WIDE_INT)
3372 hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1);
3375 mask_hi = ((unsigned HOST_WIDE_INT) -1
3376 >> (2 * HOST_BITS_PER_WIDE_INT - width));
3382 lo = (unsigned HOST_WIDE_INT) 1 << (width - 1);
3385 mask_lo = ((unsigned HOST_WIDE_INT) -1
3386 >> (HOST_BITS_PER_WIDE_INT - width));
3389 /* We mask off those bits beyond TREE_TYPE (exp) so that we can
3390 treat VAL as if it were unsigned. */
3391 if ((TREE_INT_CST_HIGH (val) & mask_hi) == hi
3392 && (TREE_INT_CST_LOW (val) & mask_lo) == lo)
3395 /* Handle extension from a narrower type. */
3396 if (TREE_CODE (exp) == NOP_EXPR
3397 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width)
3398 return sign_bit_p (TREE_OPERAND (exp, 0), val);
3403 /* Subroutine for fold_truthop: determine if an operand is simple enough
3404 to be evaluated unconditionally. */
3407 simple_operand_p (tree exp)
3409 /* Strip any conversions that don't change the machine mode. */
3410 while ((TREE_CODE (exp) == NOP_EXPR
3411 || TREE_CODE (exp) == CONVERT_EXPR)
3412 && (TYPE_MODE (TREE_TYPE (exp))
3413 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)))))
3414 exp = TREE_OPERAND (exp, 0);
3416 return (TREE_CODE_CLASS (TREE_CODE (exp)) == 'c'
3418 && ! TREE_ADDRESSABLE (exp)
3419 && ! TREE_THIS_VOLATILE (exp)
3420 && ! DECL_NONLOCAL (exp)
3421 /* Don't regard global variables as simple. They may be
3422 allocated in ways unknown to the compiler (shared memory,
3423 #pragma weak, etc). */
3424 && ! TREE_PUBLIC (exp)
3425 && ! DECL_EXTERNAL (exp)
3426 /* Loading a static variable is unduly expensive, but global
3427 registers aren't expensive. */
3428 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
3431 /* The following functions are subroutines to fold_range_test and allow it to
3432 try to change a logical combination of comparisons into a range test.
3435 X == 2 || X == 3 || X == 4 || X == 5
3439 (unsigned) (X - 2) <= 3
3441 We describe each set of comparisons as being either inside or outside
3442 a range, using a variable named like IN_P, and then describe the
3443 range with a lower and upper bound. If one of the bounds is omitted,
3444 it represents either the highest or lowest value of the type.
3446 In the comments below, we represent a range by two numbers in brackets
3447 preceded by a "+" to designate being inside that range, or a "-" to
3448 designate being outside that range, so the condition can be inverted by
3449 flipping the prefix. An omitted bound is represented by a "-". For
3450 example, "- [-, 10]" means being outside the range starting at the lowest
3451 possible value and ending at 10, in other words, being greater than 10.
3452 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
3455 We set up things so that the missing bounds are handled in a consistent
3456 manner so neither a missing bound nor "true" and "false" need to be
3457 handled using a special case. */
3459 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
3460 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
3461 and UPPER1_P are nonzero if the respective argument is an upper bound
3462 and zero for a lower. TYPE, if nonzero, is the type of the result; it
3463 must be specified for a comparison. ARG1 will be converted to ARG0's
3464 type if both are specified. */
3467 range_binop (enum tree_code code, tree type, tree arg0, int upper0_p,
3468 tree arg1, int upper1_p)
3474 /* If neither arg represents infinity, do the normal operation.
3475 Else, if not a comparison, return infinity. Else handle the special
3476 comparison rules. Note that most of the cases below won't occur, but
3477 are handled for consistency. */
3479 if (arg0 != 0 && arg1 != 0)
3481 tem = fold (build2 (code, type != 0 ? type : TREE_TYPE (arg0),
3482 arg0, fold_convert (TREE_TYPE (arg0), arg1)));
3484 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
3487 if (TREE_CODE_CLASS (code) != '<')
3490 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
3491 for neither. In real maths, we cannot assume open ended ranges are
3492 the same. But, this is computer arithmetic, where numbers are finite.
3493 We can therefore make the transformation of any unbounded range with
3494 the value Z, Z being greater than any representable number. This permits
3495 us to treat unbounded ranges as equal. */
3496 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
3497 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
3501 result = sgn0 == sgn1;
3504 result = sgn0 != sgn1;
3507 result = sgn0 < sgn1;
3510 result = sgn0 <= sgn1;
3513 result = sgn0 > sgn1;
3516 result = sgn0 >= sgn1;
3522 return constant_boolean_node (result, type);
3525 /* Given EXP, a logical expression, set the range it is testing into
3526 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
3527 actually being tested. *PLOW and *PHIGH will be made of the same type
3528 as the returned expression. If EXP is not a comparison, we will most
3529 likely not be returning a useful value and range. */
3532 make_range (tree exp, int *pin_p, tree *plow, tree *phigh)
3534 enum tree_code code;
3535 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
3536 tree exp_type = NULL_TREE, arg0_type = NULL_TREE;
3538 tree low, high, n_low, n_high;
3540 /* Start with simply saying "EXP != 0" and then look at the code of EXP
3541 and see if we can refine the range. Some of the cases below may not
3542 happen, but it doesn't seem worth worrying about this. We "continue"
3543 the outer loop when we've changed something; otherwise we "break"
3544 the switch, which will "break" the while. */
3547 low = high = fold_convert (TREE_TYPE (exp), integer_zero_node);
3551 code = TREE_CODE (exp);
3552 exp_type = TREE_TYPE (exp);
3554 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
3556 if (first_rtl_op (code) > 0)
3557 arg0 = TREE_OPERAND (exp, 0);
3558 if (TREE_CODE_CLASS (code) == '<'
3559 || TREE_CODE_CLASS (code) == '1'
3560 || TREE_CODE_CLASS (code) == '2')
3561 arg0_type = TREE_TYPE (arg0);
3562 if (TREE_CODE_CLASS (code) == '2'
3563 || TREE_CODE_CLASS (code) == '<'
3564 || (TREE_CODE_CLASS (code) == 'e'
3565 && TREE_CODE_LENGTH (code) > 1))
3566 arg1 = TREE_OPERAND (exp, 1);
3571 case TRUTH_NOT_EXPR:
3572 in_p = ! in_p, exp = arg0;
3575 case EQ_EXPR: case NE_EXPR:
3576 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
3577 /* We can only do something if the range is testing for zero
3578 and if the second operand is an integer constant. Note that
3579 saying something is "in" the range we make is done by
3580 complementing IN_P since it will set in the initial case of
3581 being not equal to zero; "out" is leaving it alone. */
3582 if (low == 0 || high == 0
3583 || ! integer_zerop (low) || ! integer_zerop (high)
3584 || TREE_CODE (arg1) != INTEGER_CST)
3589 case NE_EXPR: /* - [c, c] */
3592 case EQ_EXPR: /* + [c, c] */
3593 in_p = ! in_p, low = high = arg1;
3595 case GT_EXPR: /* - [-, c] */
3596 low = 0, high = arg1;
3598 case GE_EXPR: /* + [c, -] */
3599 in_p = ! in_p, low = arg1, high = 0;
3601 case LT_EXPR: /* - [c, -] */
3602 low = arg1, high = 0;
3604 case LE_EXPR: /* + [-, c] */
3605 in_p = ! in_p, low = 0, high = arg1;
3611 /* If this is an unsigned comparison, we also know that EXP is
3612 greater than or equal to zero. We base the range tests we make
3613 on that fact, so we record it here so we can parse existing
3614 range tests. We test arg0_type since often the return type
3615 of, e.g. EQ_EXPR, is boolean. */
3616 if (TYPE_UNSIGNED (arg0_type) && (low == 0 || high == 0))
3618 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3620 fold_convert (arg0_type, integer_zero_node),
3624 in_p = n_in_p, low = n_low, high = n_high;
3626 /* If the high bound is missing, but we have a nonzero low
3627 bound, reverse the range so it goes from zero to the low bound
3629 if (high == 0 && low && ! integer_zerop (low))
3632 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
3633 integer_one_node, 0);
3634 low = fold_convert (arg0_type, integer_zero_node);
3642 /* (-x) IN [a,b] -> x in [-b, -a] */
3643 n_low = range_binop (MINUS_EXPR, exp_type,
3644 fold_convert (exp_type, integer_zero_node),
3646 n_high = range_binop (MINUS_EXPR, exp_type,
3647 fold_convert (exp_type, integer_zero_node),
3649 low = n_low, high = n_high;
3655 exp = build2 (MINUS_EXPR, exp_type, negate_expr (arg0),
3656 fold_convert (exp_type, integer_one_node));
3659 case PLUS_EXPR: case MINUS_EXPR:
3660 if (TREE_CODE (arg1) != INTEGER_CST)
3663 /* If EXP is signed, any overflow in the computation is undefined,
3664 so we don't worry about it so long as our computations on
3665 the bounds don't overflow. For unsigned, overflow is defined
3666 and this is exactly the right thing. */
3667 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3668 arg0_type, low, 0, arg1, 0);
3669 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3670 arg0_type, high, 1, arg1, 0);
3671 if ((n_low != 0 && TREE_OVERFLOW (n_low))
3672 || (n_high != 0 && TREE_OVERFLOW (n_high)))
3675 /* Check for an unsigned range which has wrapped around the maximum
3676 value thus making n_high < n_low, and normalize it. */
3677 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
3679 low = range_binop (PLUS_EXPR, arg0_type, n_high, 0,
3680 integer_one_node, 0);
3681 high = range_binop (MINUS_EXPR, arg0_type, n_low, 0,
3682 integer_one_node, 0);
3684 /* If the range is of the form +/- [ x+1, x ], we won't
3685 be able to normalize it. But then, it represents the
3686 whole range or the empty set, so make it
3688 if (tree_int_cst_equal (n_low, low)
3689 && tree_int_cst_equal (n_high, high))
3695 low = n_low, high = n_high;
3700 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
3701 if (TYPE_PRECISION (arg0_type) > TYPE_PRECISION (exp_type))
3704 if (! INTEGRAL_TYPE_P (arg0_type)
3705 || (low != 0 && ! int_fits_type_p (low, arg0_type))
3706 || (high != 0 && ! int_fits_type_p (high, arg0_type)))
3709 n_low = low, n_high = high;
3712 n_low = fold_convert (arg0_type, n_low);
3715 n_high = fold_convert (arg0_type, n_high);
3718 /* If we're converting arg0 from an unsigned type, to exp,
3719 a signed type, we will be doing the comparison as unsigned.
3720 The tests above have already verified that LOW and HIGH
3723 So we have to ensure that we will handle large unsigned
3724 values the same way that the current signed bounds treat
3727 if (!TYPE_UNSIGNED (exp_type) && TYPE_UNSIGNED (arg0_type))
3730 tree equiv_type = lang_hooks.types.type_for_mode
3731 (TYPE_MODE (arg0_type), 1);
3733 /* A range without an upper bound is, naturally, unbounded.
3734 Since convert would have cropped a very large value, use
3735 the max value for the destination type. */
3737 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
3738 : TYPE_MAX_VALUE (arg0_type);
3740 if (TYPE_PRECISION (exp_type) == TYPE_PRECISION (arg0_type))
3741 high_positive = fold (build2 (RSHIFT_EXPR, arg0_type,
3742 fold_convert (arg0_type,
3744 fold_convert (arg0_type,
3745 integer_one_node)));
3747 /* If the low bound is specified, "and" the range with the
3748 range for which the original unsigned value will be
3752 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3753 1, n_low, n_high, 1,
3754 fold_convert (arg0_type,
3759 in_p = (n_in_p == in_p);
3763 /* Otherwise, "or" the range with the range of the input
3764 that will be interpreted as negative. */
3765 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3766 0, n_low, n_high, 1,
3767 fold_convert (arg0_type,
3772 in_p = (in_p != n_in_p);
3777 low = n_low, high = n_high;
3787 /* If EXP is a constant, we can evaluate whether this is true or false. */
3788 if (TREE_CODE (exp) == INTEGER_CST)
3790 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
3792 && integer_onep (range_binop (LE_EXPR, integer_type_node,
3798 *pin_p = in_p, *plow = low, *phigh = high;
3802 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3803 type, TYPE, return an expression to test if EXP is in (or out of, depending
3804 on IN_P) the range. Return 0 if the test couldn't be created. */
3807 build_range_check (tree type, tree exp, int in_p, tree low, tree high)
3809 tree etype = TREE_TYPE (exp);
3814 value = build_range_check (type, exp, 1, low, high);
3816 return invert_truthvalue (value);
3821 if (low == 0 && high == 0)
3822 return fold_convert (type, integer_one_node);
3825 return fold (build2 (LE_EXPR, type, exp, high));
3828 return fold (build2 (GE_EXPR, type, exp, low));
3830 if (operand_equal_p (low, high, 0))
3831 return fold (build2 (EQ_EXPR, type, exp, low));
3833 if (integer_zerop (low))
3835 if (! TYPE_UNSIGNED (etype))
3837 etype = lang_hooks.types.unsigned_type (etype);
3838 high = fold_convert (etype, high);
3839 exp = fold_convert (etype, exp);
3841 return build_range_check (type, exp, 1, 0, high);
3844 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
3845 if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST)
3847 unsigned HOST_WIDE_INT lo;
3851 prec = TYPE_PRECISION (etype);
3852 if (prec <= HOST_BITS_PER_WIDE_INT)
3855 lo = ((unsigned HOST_WIDE_INT) 1 << (prec - 1)) - 1;
3859 hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1;
3860 lo = (unsigned HOST_WIDE_INT) -1;
3863 if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo)
3865 if (TYPE_UNSIGNED (etype))
3867 etype = lang_hooks.types.signed_type (etype);
3868 exp = fold_convert (etype, exp);
3870 return fold (build2 (GT_EXPR, type, exp,
3871 fold_convert (etype, integer_zero_node)));
3875 value = const_binop (MINUS_EXPR, high, low, 0);
3876 if (value != 0 && TREE_OVERFLOW (value) && ! TYPE_UNSIGNED (etype))
3878 tree utype, minv, maxv;
3880 /* Check if (unsigned) INT_MAX + 1 == (unsigned) INT_MIN
3881 for the type in question, as we rely on this here. */
3882 switch (TREE_CODE (etype))
3887 utype = lang_hooks.types.unsigned_type (etype);
3888 maxv = fold_convert (utype, TYPE_MAX_VALUE (etype));
3889 maxv = range_binop (PLUS_EXPR, NULL_TREE, maxv, 1,
3890 integer_one_node, 1);
3891 minv = fold_convert (utype, TYPE_MIN_VALUE (etype));
3892 if (integer_zerop (range_binop (NE_EXPR, integer_type_node,
3896 high = fold_convert (etype, high);
3897 low = fold_convert (etype, low);
3898 exp = fold_convert (etype, exp);
3899 value = const_binop (MINUS_EXPR, high, low, 0);
3907 if (value != 0 && ! TREE_OVERFLOW (value))
3908 return build_range_check (type,
3909 fold (build2 (MINUS_EXPR, etype, exp, low)),
3910 1, fold_convert (etype, integer_zero_node),
3916 /* Given two ranges, see if we can merge them into one. Return 1 if we
3917 can, 0 if we can't. Set the output range into the specified parameters. */
3920 merge_ranges (int *pin_p, tree *plow, tree *phigh, int in0_p, tree low0,
3921 tree high0, int in1_p, tree low1, tree high1)
3929 int lowequal = ((low0 == 0 && low1 == 0)
3930 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3931 low0, 0, low1, 0)));
3932 int highequal = ((high0 == 0 && high1 == 0)
3933 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3934 high0, 1, high1, 1)));
3936 /* Make range 0 be the range that starts first, or ends last if they
3937 start at the same value. Swap them if it isn't. */
3938 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
3941 && integer_onep (range_binop (GT_EXPR, integer_type_node,
3942 high1, 1, high0, 1))))
3944 temp = in0_p, in0_p = in1_p, in1_p = temp;
3945 tem = low0, low0 = low1, low1 = tem;
3946 tem = high0, high0 = high1, high1 = tem;
3949 /* Now flag two cases, whether the ranges are disjoint or whether the
3950 second range is totally subsumed in the first. Note that the tests
3951 below are simplified by the ones above. */
3952 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
3953 high0, 1, low1, 0));
3954 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
3955 high1, 1, high0, 1));
3957 /* We now have four cases, depending on whether we are including or
3958 excluding the two ranges. */
3961 /* If they don't overlap, the result is false. If the second range
3962 is a subset it is the result. Otherwise, the range is from the start
3963 of the second to the end of the first. */
3965 in_p = 0, low = high = 0;
3967 in_p = 1, low = low1, high = high1;
3969 in_p = 1, low = low1, high = high0;
3972 else if (in0_p && ! in1_p)
3974 /* If they don't overlap, the result is the first range. If they are
3975 equal, the result is false. If the second range is a subset of the
3976 first, and the ranges begin at the same place, we go from just after
3977 the end of the first range to the end of the second. If the second
3978 range is not a subset of the first, or if it is a subset and both
3979 ranges end at the same place, the range starts at the start of the
3980 first range and ends just before the second range.
3981 Otherwise, we can't describe this as a single range. */
3983 in_p = 1, low = low0, high = high0;
3984 else if (lowequal && highequal)
3985 in_p = 0, low = high = 0;
3986 else if (subset && lowequal)
3988 in_p = 1, high = high0;
3989 low = range_binop (PLUS_EXPR, NULL_TREE, high1, 0,
3990 integer_one_node, 0);
3992 else if (! subset || highequal)
3994 in_p = 1, low = low0;
3995 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
3996 integer_one_node, 0);
4002 else if (! in0_p && in1_p)
4004 /* If they don't overlap, the result is the second range. If the second
4005 is a subset of the first, the result is false. Otherwise,
4006 the range starts just after the first range and ends at the
4007 end of the second. */
4009 in_p = 1, low = low1, high = high1;
4010 else if (subset || highequal)
4011 in_p = 0, low = high = 0;
4014 in_p = 1, high = high1;
4015 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
4016 integer_one_node, 0);
4022 /* The case where we are excluding both ranges. Here the complex case
4023 is if they don't overlap. In that case, the only time we have a
4024 range is if they are adjacent. If the second is a subset of the
4025 first, the result is the first. Otherwise, the range to exclude
4026 starts at the beginning of the first range and ends at the end of the
4030 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
4031 range_binop (PLUS_EXPR, NULL_TREE,
4033 integer_one_node, 1),
4035 in_p = 0, low = low0, high = high1;
4038 /* Canonicalize - [min, x] into - [-, x]. */
4039 if (low0 && TREE_CODE (low0) == INTEGER_CST)
4040 switch (TREE_CODE (TREE_TYPE (low0)))
4043 if (TYPE_PRECISION (TREE_TYPE (low0))
4044 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (low0))))
4049 if (tree_int_cst_equal (low0,
4050 TYPE_MIN_VALUE (TREE_TYPE (low0))))
4054 if (TYPE_UNSIGNED (TREE_TYPE (low0))
4055 && integer_zerop (low0))
4062 /* Canonicalize - [x, max] into - [x, -]. */
4063 if (high1 && TREE_CODE (high1) == INTEGER_CST)
4064 switch (TREE_CODE (TREE_TYPE (high1)))
4067 if (TYPE_PRECISION (TREE_TYPE (high1))
4068 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (high1))))
4073 if (tree_int_cst_equal (high1,
4074 TYPE_MAX_VALUE (TREE_TYPE (high1))))
4078 if (TYPE_UNSIGNED (TREE_TYPE (high1))
4079 && integer_zerop (range_binop (PLUS_EXPR, NULL_TREE,
4081 integer_one_node, 1)))
4088 /* The ranges might be also adjacent between the maximum and
4089 minimum values of the given type. For
4090 - [{min,-}, x] and - [y, {max,-}] ranges where x + 1 < y
4091 return + [x + 1, y - 1]. */
4092 if (low0 == 0 && high1 == 0)
4094 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
4095 integer_one_node, 1);
4096 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
4097 integer_one_node, 0);
4098 if (low == 0 || high == 0)
4108 in_p = 0, low = low0, high = high0;
4110 in_p = 0, low = low0, high = high1;
4113 *pin_p = in_p, *plow = low, *phigh = high;
4118 /* Subroutine of fold, looking inside expressions of the form
4119 A op B ? A : C, where ARG0, ARG1 and ARG2 are the three operands
4120 of the COND_EXPR. This function is being used also to optimize
4121 A op B ? C : A, by reversing the comparison first.
4123 Return a folded expression whose code is not a COND_EXPR
4124 anymore, or NULL_TREE if no folding opportunity is found. */
4127 fold_cond_expr_with_comparison (tree type, tree arg0, tree arg1, tree arg2)
4129 enum tree_code comp_code = TREE_CODE (arg0);
4130 tree arg00 = TREE_OPERAND (arg0, 0);
4131 tree arg01 = TREE_OPERAND (arg0, 1);
4132 tree arg1_type = TREE_TYPE (arg1);
4138 /* If we have A op 0 ? A : -A, consider applying the following
4141 A == 0? A : -A same as -A
4142 A != 0? A : -A same as A
4143 A >= 0? A : -A same as abs (A)
4144 A > 0? A : -A same as abs (A)
4145 A <= 0? A : -A same as -abs (A)
4146 A < 0? A : -A same as -abs (A)
4148 None of these transformations work for modes with signed
4149 zeros. If A is +/-0, the first two transformations will
4150 change the sign of the result (from +0 to -0, or vice
4151 versa). The last four will fix the sign of the result,
4152 even though the original expressions could be positive or
4153 negative, depending on the sign of A.
4155 Note that all these transformations are correct if A is
4156 NaN, since the two alternatives (A and -A) are also NaNs. */
4157 if ((FLOAT_TYPE_P (TREE_TYPE (arg01))
4158 ? real_zerop (arg01)
4159 : integer_zerop (arg01))
4160 && TREE_CODE (arg2) == NEGATE_EXPR
4161 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
4166 tem = fold_convert (arg1_type, arg1);
4167 return pedantic_non_lvalue (fold_convert (type, negate_expr (tem)));
4170 return pedantic_non_lvalue (fold_convert (type, arg1));
4173 if (flag_trapping_math)
4178 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
4179 arg1 = fold_convert (lang_hooks.types.signed_type
4180 (TREE_TYPE (arg1)), arg1);
4181 tem = fold (build1 (ABS_EXPR, TREE_TYPE (arg1), arg1));
4182 return pedantic_non_lvalue (fold_convert (type, tem));
4185 if (flag_trapping_math)
4189 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
4190 arg1 = fold_convert (lang_hooks.types.signed_type
4191 (TREE_TYPE (arg1)), arg1);
4192 tem = fold (build1 (ABS_EXPR, TREE_TYPE (arg1), arg1));
4193 return negate_expr (fold_convert (type, tem));
4195 gcc_assert (TREE_CODE_CLASS (comp_code) == '<');
4199 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
4200 A == 0 ? A : 0 is always 0 unless A is -0. Note that
4201 both transformations are correct when A is NaN: A != 0
4202 is then true, and A == 0 is false. */
4204 if (integer_zerop (arg01) && integer_zerop (arg2))
4206 if (comp_code == NE_EXPR)
4207 return pedantic_non_lvalue (fold_convert (type, arg1));
4208 else if (comp_code == EQ_EXPR)
4209 return fold_convert (type, integer_zero_node);
4212 /* Try some transformations of A op B ? A : B.
4214 A == B? A : B same as B
4215 A != B? A : B same as A
4216 A >= B? A : B same as max (A, B)
4217 A > B? A : B same as max (B, A)
4218 A <= B? A : B same as min (A, B)
4219 A < B? A : B same as min (B, A)
4221 As above, these transformations don't work in the presence
4222 of signed zeros. For example, if A and B are zeros of
4223 opposite sign, the first two transformations will change
4224 the sign of the result. In the last four, the original
4225 expressions give different results for (A=+0, B=-0) and
4226 (A=-0, B=+0), but the transformed expressions do not.
4228 The first two transformations are correct if either A or B
4229 is a NaN. In the first transformation, the condition will
4230 be false, and B will indeed be chosen. In the case of the
4231 second transformation, the condition A != B will be true,
4232 and A will be chosen.
4234 The conversions to max() and min() are not correct if B is
4235 a number and A is not. The conditions in the original
4236 expressions will be false, so all four give B. The min()
4237 and max() versions would give a NaN instead. */
4238 if (operand_equal_for_comparison_p (arg01, arg2, arg00))
4240 tree comp_op0 = arg00;
4241 tree comp_op1 = arg01;
4242 tree comp_type = TREE_TYPE (comp_op0);
4244 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
4245 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
4255 return pedantic_non_lvalue (fold_convert (type, arg2));
4257 return pedantic_non_lvalue (fold_convert (type, arg1));
4262 /* In C++ a ?: expression can be an lvalue, so put the
4263 operand which will be used if they are equal first
4264 so that we can convert this back to the
4265 corresponding COND_EXPR. */
4266 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4268 comp_op0 = fold_convert (comp_type, comp_op0);
4269 comp_op1 = fold_convert (comp_type, comp_op1);
4270 tem = (comp_code == LE_EXPR || comp_code == UNLE_EXPR)
4271 ? fold (build2 (MIN_EXPR, comp_type, comp_op0, comp_op1))
4272 : fold (build2 (MIN_EXPR, comp_type, comp_op1, comp_op0));
4273 return pedantic_non_lvalue (fold_convert (type, tem));
4280 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4282 comp_op0 = fold_convert (comp_type, comp_op0);
4283 comp_op1 = fold_convert (comp_type, comp_op1);
4284 tem = (comp_code == GE_EXPR || comp_code == UNGE_EXPR)
4285 ? fold (build2 (MAX_EXPR, comp_type, comp_op0, comp_op1))
4286 : fold (build2 (MAX_EXPR, comp_type, comp_op1, comp_op0));
4287 return pedantic_non_lvalue (fold_convert (type, tem));
4291 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4292 return pedantic_non_lvalue (fold_convert (type, arg2));
4295 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4296 return pedantic_non_lvalue (fold_convert (type, arg1));
4299 gcc_assert (TREE_CODE_CLASS (comp_code) == '<');
4304 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
4305 we might still be able to simplify this. For example,
4306 if C1 is one less or one more than C2, this might have started
4307 out as a MIN or MAX and been transformed by this function.
4308 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
4310 if (INTEGRAL_TYPE_P (type)
4311 && TREE_CODE (arg01) == INTEGER_CST
4312 && TREE_CODE (arg2) == INTEGER_CST)
4316 /* We can replace A with C1 in this case. */
4317 arg1 = fold_convert (type, arg01);
4318 return fold (build3 (COND_EXPR, type, arg0, arg1, arg2));
4321 /* If C1 is C2 + 1, this is min(A, C2). */
4322 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
4324 && operand_equal_p (arg01,
4325 const_binop (PLUS_EXPR, arg2,
4326 integer_one_node, 0),
4328 return pedantic_non_lvalue (fold (build2 (MIN_EXPR,
4329 type, arg1, arg2)));
4333 /* If C1 is C2 - 1, this is min(A, C2). */
4334 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
4336 && operand_equal_p (arg01,
4337 const_binop (MINUS_EXPR, arg2,
4338 integer_one_node, 0),
4340 return pedantic_non_lvalue (fold (build2 (MIN_EXPR,
4341 type, arg1, arg2)));
4345 /* If C1 is C2 - 1, this is max(A, C2). */
4346 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
4348 && operand_equal_p (arg01,
4349 const_binop (MINUS_EXPR, arg2,
4350 integer_one_node, 0),
4352 return pedantic_non_lvalue (fold (build2 (MAX_EXPR,
4353 type, arg1, arg2)));
4357 /* If C1 is C2 + 1, this is max(A, C2). */
4358 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
4360 && operand_equal_p (arg01,
4361 const_binop (PLUS_EXPR, arg2,
4362 integer_one_node, 0),
4364 return pedantic_non_lvalue (fold (build2 (MAX_EXPR,
4365 type, arg1, arg2)));
4378 #ifndef RANGE_TEST_NON_SHORT_CIRCUIT
4379 #define RANGE_TEST_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
4382 /* EXP is some logical combination of boolean tests. See if we can
4383 merge it into some range test. Return the new tree if so. */
4386 fold_range_test (tree exp)
4388 int or_op = (TREE_CODE (exp) == TRUTH_ORIF_EXPR
4389 || TREE_CODE (exp) == TRUTH_OR_EXPR);
4390 int in0_p, in1_p, in_p;
4391 tree low0, low1, low, high0, high1, high;
4392 tree lhs = make_range (TREE_OPERAND (exp, 0), &in0_p, &low0, &high0);
4393 tree rhs = make_range (TREE_OPERAND (exp, 1), &in1_p, &low1, &high1);
4396 /* If this is an OR operation, invert both sides; we will invert
4397 again at the end. */
4399 in0_p = ! in0_p, in1_p = ! in1_p;
4401 /* If both expressions are the same, if we can merge the ranges, and we
4402 can build the range test, return it or it inverted. If one of the
4403 ranges is always true or always false, consider it to be the same
4404 expression as the other. */
4405 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
4406 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
4408 && 0 != (tem = (build_range_check (TREE_TYPE (exp),
4410 : rhs != 0 ? rhs : integer_zero_node,
4412 return or_op ? invert_truthvalue (tem) : tem;
4414 /* On machines where the branch cost is expensive, if this is a
4415 short-circuited branch and the underlying object on both sides
4416 is the same, make a non-short-circuit operation. */
4417 else if (RANGE_TEST_NON_SHORT_CIRCUIT
4418 && lhs != 0 && rhs != 0
4419 && (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
4420 || TREE_CODE (exp) == TRUTH_ORIF_EXPR)
4421 && operand_equal_p (lhs, rhs, 0))
4423 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
4424 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
4425 which cases we can't do this. */
4426 if (simple_operand_p (lhs))
4427 return build2 (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
4428 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
4429 TREE_TYPE (exp), TREE_OPERAND (exp, 0),
4430 TREE_OPERAND (exp, 1));
4432 else if (lang_hooks.decls.global_bindings_p () == 0
4433 && ! CONTAINS_PLACEHOLDER_P (lhs))
4435 tree common = save_expr (lhs);
4437 if (0 != (lhs = build_range_check (TREE_TYPE (exp), common,
4438 or_op ? ! in0_p : in0_p,
4440 && (0 != (rhs = build_range_check (TREE_TYPE (exp), common,
4441 or_op ? ! in1_p : in1_p,
4443 return build2 (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
4444 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
4445 TREE_TYPE (exp), lhs, rhs);
4452 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
4453 bit value. Arrange things so the extra bits will be set to zero if and
4454 only if C is signed-extended to its full width. If MASK is nonzero,
4455 it is an INTEGER_CST that should be AND'ed with the extra bits. */
4458 unextend (tree c, int p, int unsignedp, tree mask)
4460 tree type = TREE_TYPE (c);
4461 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
4464 if (p == modesize || unsignedp)
4467 /* We work by getting just the sign bit into the low-order bit, then
4468 into the high-order bit, then sign-extend. We then XOR that value
4470 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
4471 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
4473 /* We must use a signed type in order to get an arithmetic right shift.
4474 However, we must also avoid introducing accidental overflows, so that
4475 a subsequent call to integer_zerop will work. Hence we must
4476 do the type conversion here. At this point, the constant is either
4477 zero or one, and the conversion to a signed type can never overflow.
4478 We could get an overflow if this conversion is done anywhere else. */
4479 if (TYPE_UNSIGNED (type))
4480 temp = fold_convert (lang_hooks.types.signed_type (type), temp);
4482 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
4483 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
4485 temp = const_binop (BIT_AND_EXPR, temp,
4486 fold_convert (TREE_TYPE (c), mask), 0);
4487 /* If necessary, convert the type back to match the type of C. */
4488 if (TYPE_UNSIGNED (type))
4489 temp = fold_convert (type, temp);
4491 return fold_convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
4494 /* Find ways of folding logical expressions of LHS and RHS:
4495 Try to merge two comparisons to the same innermost item.
4496 Look for range tests like "ch >= '0' && ch <= '9'".
4497 Look for combinations of simple terms on machines with expensive branches
4498 and evaluate the RHS unconditionally.
4500 For example, if we have p->a == 2 && p->b == 4 and we can make an
4501 object large enough to span both A and B, we can do this with a comparison
4502 against the object ANDed with the a mask.
4504 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
4505 operations to do this with one comparison.
4507 We check for both normal comparisons and the BIT_AND_EXPRs made this by
4508 function and the one above.
4510 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
4511 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
4513 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
4516 We return the simplified tree or 0 if no optimization is possible. */
4519 fold_truthop (enum tree_code code, tree truth_type, tree lhs, tree rhs)
4521 /* If this is the "or" of two comparisons, we can do something if
4522 the comparisons are NE_EXPR. If this is the "and", we can do something
4523 if the comparisons are EQ_EXPR. I.e.,
4524 (a->b == 2 && a->c == 4) can become (a->new == NEW).
4526 WANTED_CODE is this operation code. For single bit fields, we can
4527 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
4528 comparison for one-bit fields. */
4530 enum tree_code wanted_code;
4531 enum tree_code lcode, rcode;
4532 tree ll_arg, lr_arg, rl_arg, rr_arg;
4533 tree ll_inner, lr_inner, rl_inner, rr_inner;
4534 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
4535 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
4536 HOST_WIDE_INT xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
4537 HOST_WIDE_INT lnbitsize, lnbitpos, rnbitsize, rnbitpos;
4538 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
4539 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
4540 enum machine_mode lnmode, rnmode;
4541 tree ll_mask, lr_mask, rl_mask, rr_mask;
4542 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
4543 tree l_const, r_const;
4544 tree lntype, rntype, result;
4545 int first_bit, end_bit;
4548 /* Start by getting the comparison codes. Fail if anything is volatile.
4549 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
4550 it were surrounded with a NE_EXPR. */
4552 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
4555 lcode = TREE_CODE (lhs);
4556 rcode = TREE_CODE (rhs);
4558 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
4560 lhs = build2 (NE_EXPR, truth_type, lhs,
4561 fold_convert (TREE_TYPE (lhs), integer_zero_node));
4565 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
4567 rhs = build2 (NE_EXPR, truth_type, rhs,
4568 fold_convert (TREE_TYPE (rhs), integer_zero_node));
4572 if (TREE_CODE_CLASS (lcode) != '<' || TREE_CODE_CLASS (rcode) != '<')
4575 ll_arg = TREE_OPERAND (lhs, 0);
4576 lr_arg = TREE_OPERAND (lhs, 1);
4577 rl_arg = TREE_OPERAND (rhs, 0);
4578 rr_arg = TREE_OPERAND (rhs, 1);
4580 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
4581 if (simple_operand_p (ll_arg)
4582 && simple_operand_p (lr_arg))
4585 if (operand_equal_p (ll_arg, rl_arg, 0)
4586 && operand_equal_p (lr_arg, rr_arg, 0))
4588 result = combine_comparisons (code, lcode, rcode,
4589 truth_type, ll_arg, lr_arg);
4593 else if (operand_equal_p (ll_arg, rr_arg, 0)
4594 && operand_equal_p (lr_arg, rl_arg, 0))
4596 result = combine_comparisons (code, lcode,
4597 swap_tree_comparison (rcode),
4598 truth_type, ll_arg, lr_arg);
4604 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
4605 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
4607 /* If the RHS can be evaluated unconditionally and its operands are
4608 simple, it wins to evaluate the RHS unconditionally on machines
4609 with expensive branches. In this case, this isn't a comparison
4610 that can be merged. Avoid doing this if the RHS is a floating-point
4611 comparison since those can trap. */
4613 if (BRANCH_COST >= 2
4614 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
4615 && simple_operand_p (rl_arg)
4616 && simple_operand_p (rr_arg))
4618 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
4619 if (code == TRUTH_OR_EXPR
4620 && lcode == NE_EXPR && integer_zerop (lr_arg)
4621 && rcode == NE_EXPR && integer_zerop (rr_arg)
4622 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
4623 return build2 (NE_EXPR, truth_type,
4624 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
4626 fold_convert (TREE_TYPE (ll_arg), integer_zero_node));
4628 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
4629 if (code == TRUTH_AND_EXPR
4630 && lcode == EQ_EXPR && integer_zerop (lr_arg)
4631 && rcode == EQ_EXPR && integer_zerop (rr_arg)
4632 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
4633 return build2 (EQ_EXPR, truth_type,
4634 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
4636 fold_convert (TREE_TYPE (ll_arg), integer_zero_node));
4638 return build2 (code, truth_type, lhs, rhs);
4641 /* See if the comparisons can be merged. Then get all the parameters for
4644 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
4645 || (rcode != EQ_EXPR && rcode != NE_EXPR))
4649 ll_inner = decode_field_reference (ll_arg,
4650 &ll_bitsize, &ll_bitpos, &ll_mode,
4651 &ll_unsignedp, &volatilep, &ll_mask,
4653 lr_inner = decode_field_reference (lr_arg,
4654 &lr_bitsize, &lr_bitpos, &lr_mode,
4655 &lr_unsignedp, &volatilep, &lr_mask,
4657 rl_inner = decode_field_reference (rl_arg,
4658 &rl_bitsize, &rl_bitpos, &rl_mode,
4659 &rl_unsignedp, &volatilep, &rl_mask,
4661 rr_inner = decode_field_reference (rr_arg,
4662 &rr_bitsize, &rr_bitpos, &rr_mode,
4663 &rr_unsignedp, &volatilep, &rr_mask,
4666 /* It must be true that the inner operation on the lhs of each
4667 comparison must be the same if we are to be able to do anything.
4668 Then see if we have constants. If not, the same must be true for
4670 if (volatilep || ll_inner == 0 || rl_inner == 0
4671 || ! operand_equal_p (ll_inner, rl_inner, 0))
4674 if (TREE_CODE (lr_arg) == INTEGER_CST
4675 && TREE_CODE (rr_arg) == INTEGER_CST)
4676 l_const = lr_arg, r_const = rr_arg;
4677 else if (lr_inner == 0 || rr_inner == 0
4678 || ! operand_equal_p (lr_inner, rr_inner, 0))
4681 l_const = r_const = 0;
4683 /* If either comparison code is not correct for our logical operation,
4684 fail. However, we can convert a one-bit comparison against zero into
4685 the opposite comparison against that bit being set in the field. */
4687 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
4688 if (lcode != wanted_code)
4690 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
4692 /* Make the left operand unsigned, since we are only interested
4693 in the value of one bit. Otherwise we are doing the wrong
4702 /* This is analogous to the code for l_const above. */
4703 if (rcode != wanted_code)
4705 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
4714 /* After this point all optimizations will generate bit-field
4715 references, which we might not want. */
4716 if (! lang_hooks.can_use_bit_fields_p ())
4719 /* See if we can find a mode that contains both fields being compared on
4720 the left. If we can't, fail. Otherwise, update all constants and masks
4721 to be relative to a field of that size. */
4722 first_bit = MIN (ll_bitpos, rl_bitpos);
4723 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
4724 lnmode = get_best_mode (end_bit - first_bit, first_bit,
4725 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
4727 if (lnmode == VOIDmode)
4730 lnbitsize = GET_MODE_BITSIZE (lnmode);
4731 lnbitpos = first_bit & ~ (lnbitsize - 1);
4732 lntype = lang_hooks.types.type_for_size (lnbitsize, 1);
4733 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
4735 if (BYTES_BIG_ENDIAN)
4737 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
4738 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
4741 ll_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, ll_mask),
4742 size_int (xll_bitpos), 0);
4743 rl_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, rl_mask),
4744 size_int (xrl_bitpos), 0);
4748 l_const = fold_convert (lntype, l_const);
4749 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
4750 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
4751 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
4752 fold (build1 (BIT_NOT_EXPR,
4756 warning ("comparison is always %d", wanted_code == NE_EXPR);
4758 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
4763 r_const = fold_convert (lntype, r_const);
4764 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
4765 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
4766 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
4767 fold (build1 (BIT_NOT_EXPR,
4771 warning ("comparison is always %d", wanted_code == NE_EXPR);
4773 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
4777 /* If the right sides are not constant, do the same for it. Also,
4778 disallow this optimization if a size or signedness mismatch occurs
4779 between the left and right sides. */
4782 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
4783 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
4784 /* Make sure the two fields on the right
4785 correspond to the left without being swapped. */
4786 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
4789 first_bit = MIN (lr_bitpos, rr_bitpos);
4790 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
4791 rnmode = get_best_mode (end_bit - first_bit, first_bit,
4792 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
4794 if (rnmode == VOIDmode)
4797 rnbitsize = GET_MODE_BITSIZE (rnmode);
4798 rnbitpos = first_bit & ~ (rnbitsize - 1);
4799 rntype = lang_hooks.types.type_for_size (rnbitsize, 1);
4800 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
4802 if (BYTES_BIG_ENDIAN)
4804 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
4805 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
4808 lr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, lr_mask),
4809 size_int (xlr_bitpos), 0);
4810 rr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, rr_mask),
4811 size_int (xrr_bitpos), 0);
4813 /* Make a mask that corresponds to both fields being compared.
4814 Do this for both items being compared. If the operands are the
4815 same size and the bits being compared are in the same position
4816 then we can do this by masking both and comparing the masked
4818 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4819 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
4820 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
4822 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4823 ll_unsignedp || rl_unsignedp);
4824 if (! all_ones_mask_p (ll_mask, lnbitsize))
4825 lhs = build2 (BIT_AND_EXPR, lntype, lhs, ll_mask);
4827 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
4828 lr_unsignedp || rr_unsignedp);
4829 if (! all_ones_mask_p (lr_mask, rnbitsize))
4830 rhs = build2 (BIT_AND_EXPR, rntype, rhs, lr_mask);
4832 return build2 (wanted_code, truth_type, lhs, rhs);
4835 /* There is still another way we can do something: If both pairs of
4836 fields being compared are adjacent, we may be able to make a wider
4837 field containing them both.
4839 Note that we still must mask the lhs/rhs expressions. Furthermore,
4840 the mask must be shifted to account for the shift done by
4841 make_bit_field_ref. */
4842 if ((ll_bitsize + ll_bitpos == rl_bitpos
4843 && lr_bitsize + lr_bitpos == rr_bitpos)
4844 || (ll_bitpos == rl_bitpos + rl_bitsize
4845 && lr_bitpos == rr_bitpos + rr_bitsize))
4849 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
4850 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
4851 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
4852 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
4854 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
4855 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
4856 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
4857 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
4859 /* Convert to the smaller type before masking out unwanted bits. */
4861 if (lntype != rntype)
4863 if (lnbitsize > rnbitsize)
4865 lhs = fold_convert (rntype, lhs);
4866 ll_mask = fold_convert (rntype, ll_mask);
4869 else if (lnbitsize < rnbitsize)
4871 rhs = fold_convert (lntype, rhs);
4872 lr_mask = fold_convert (lntype, lr_mask);
4877 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
4878 lhs = build2 (BIT_AND_EXPR, type, lhs, ll_mask);
4880 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
4881 rhs = build2 (BIT_AND_EXPR, type, rhs, lr_mask);
4883 return build2 (wanted_code, truth_type, lhs, rhs);
4889 /* Handle the case of comparisons with constants. If there is something in
4890 common between the masks, those bits of the constants must be the same.
4891 If not, the condition is always false. Test for this to avoid generating
4892 incorrect code below. */
4893 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
4894 if (! integer_zerop (result)
4895 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
4896 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
4898 if (wanted_code == NE_EXPR)
4900 warning ("%<or%> of unmatched not-equal tests is always 1");
4901 return constant_boolean_node (true, truth_type);
4905 warning ("%<and%> of mutually exclusive equal-tests is always 0");
4906 return constant_boolean_node (false, truth_type);
4910 /* Construct the expression we will return. First get the component
4911 reference we will make. Unless the mask is all ones the width of
4912 that field, perform the mask operation. Then compare with the
4914 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4915 ll_unsignedp || rl_unsignedp);
4917 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4918 if (! all_ones_mask_p (ll_mask, lnbitsize))
4919 result = build2 (BIT_AND_EXPR, lntype, result, ll_mask);
4921 return build2 (wanted_code, truth_type, result,
4922 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
4925 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
4929 optimize_minmax_comparison (tree t)
4931 tree type = TREE_TYPE (t);
4932 tree arg0 = TREE_OPERAND (t, 0);
4933 enum tree_code op_code;
4934 tree comp_const = TREE_OPERAND (t, 1);
4936 int consts_equal, consts_lt;
4939 STRIP_SIGN_NOPS (arg0);
4941 op_code = TREE_CODE (arg0);
4942 minmax_const = TREE_OPERAND (arg0, 1);
4943 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
4944 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
4945 inner = TREE_OPERAND (arg0, 0);
4947 /* If something does not permit us to optimize, return the original tree. */
4948 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
4949 || TREE_CODE (comp_const) != INTEGER_CST
4950 || TREE_CONSTANT_OVERFLOW (comp_const)
4951 || TREE_CODE (minmax_const) != INTEGER_CST
4952 || TREE_CONSTANT_OVERFLOW (minmax_const))
4955 /* Now handle all the various comparison codes. We only handle EQ_EXPR
4956 and GT_EXPR, doing the rest with recursive calls using logical
4958 switch (TREE_CODE (t))
4960 case NE_EXPR: case LT_EXPR: case LE_EXPR:
4962 invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t)));
4966 fold (build2 (TRUTH_ORIF_EXPR, type,
4967 optimize_minmax_comparison
4968 (build2 (EQ_EXPR, type, arg0, comp_const)),
4969 optimize_minmax_comparison
4970 (build2 (GT_EXPR, type, arg0, comp_const))));
4973 if (op_code == MAX_EXPR && consts_equal)
4974 /* MAX (X, 0) == 0 -> X <= 0 */
4975 return fold (build2 (LE_EXPR, type, inner, comp_const));
4977 else if (op_code == MAX_EXPR && consts_lt)
4978 /* MAX (X, 0) == 5 -> X == 5 */
4979 return fold (build2 (EQ_EXPR, type, inner, comp_const));
4981 else if (op_code == MAX_EXPR)
4982 /* MAX (X, 0) == -1 -> false */
4983 return omit_one_operand (type, integer_zero_node, inner);
4985 else if (consts_equal)
4986 /* MIN (X, 0) == 0 -> X >= 0 */
4987 return fold (build2 (GE_EXPR, type, inner, comp_const));
4990 /* MIN (X, 0) == 5 -> false */
4991 return omit_one_operand (type, integer_zero_node, inner);
4994 /* MIN (X, 0) == -1 -> X == -1 */
4995 return fold (build2 (EQ_EXPR, type, inner, comp_const));
4998 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
4999 /* MAX (X, 0) > 0 -> X > 0
5000 MAX (X, 0) > 5 -> X > 5 */
5001 return fold (build2 (GT_EXPR, type, inner, comp_const));
5003 else if (op_code == MAX_EXPR)
5004 /* MAX (X, 0) > -1 -> true */
5005 return omit_one_operand (type, integer_one_node, inner);
5007 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
5008 /* MIN (X, 0) > 0 -> false
5009 MIN (X, 0) > 5 -> false */
5010 return omit_one_operand (type, integer_zero_node, inner);
5013 /* MIN (X, 0) > -1 -> X > -1 */
5014 return fold (build2 (GT_EXPR, type, inner, comp_const));
5021 /* T is an integer expression that is being multiplied, divided, or taken a
5022 modulus (CODE says which and what kind of divide or modulus) by a
5023 constant C. See if we can eliminate that operation by folding it with
5024 other operations already in T. WIDE_TYPE, if non-null, is a type that
5025 should be used for the computation if wider than our type.
5027 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
5028 (X * 2) + (Y * 4). We must, however, be assured that either the original
5029 expression would not overflow or that overflow is undefined for the type
5030 in the language in question.
5032 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
5033 the machine has a multiply-accumulate insn or that this is part of an
5034 addressing calculation.
5036 If we return a non-null expression, it is an equivalent form of the
5037 original computation, but need not be in the original type. */
5040 extract_muldiv (tree t, tree c, enum tree_code code, tree wide_type)
5042 /* To avoid exponential search depth, refuse to allow recursion past
5043 three levels. Beyond that (1) it's highly unlikely that we'll find
5044 something interesting and (2) we've probably processed it before
5045 when we built the inner expression. */
5054 ret = extract_muldiv_1 (t, c, code, wide_type);
5061 extract_muldiv_1 (tree t, tree c, enum tree_code code, tree wide_type)
5063 tree type = TREE_TYPE (t);
5064 enum tree_code tcode = TREE_CODE (t);
5065 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
5066 > GET_MODE_SIZE (TYPE_MODE (type)))
5067 ? wide_type : type);
5069 int same_p = tcode == code;
5070 tree op0 = NULL_TREE, op1 = NULL_TREE;
5072 /* Don't deal with constants of zero here; they confuse the code below. */
5073 if (integer_zerop (c))
5076 if (TREE_CODE_CLASS (tcode) == '1')
5077 op0 = TREE_OPERAND (t, 0);
5079 if (TREE_CODE_CLASS (tcode) == '2')
5080 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
5082 /* Note that we need not handle conditional operations here since fold
5083 already handles those cases. So just do arithmetic here. */
5087 /* For a constant, we can always simplify if we are a multiply
5088 or (for divide and modulus) if it is a multiple of our constant. */
5089 if (code == MULT_EXPR
5090 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
5091 return const_binop (code, fold_convert (ctype, t),
5092 fold_convert (ctype, c), 0);
5095 case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
5096 /* If op0 is an expression ... */
5097 if ((TREE_CODE_CLASS (TREE_CODE (op0)) == '<'
5098 || TREE_CODE_CLASS (TREE_CODE (op0)) == '1'
5099 || TREE_CODE_CLASS (TREE_CODE (op0)) == '2'
5100 || TREE_CODE_CLASS (TREE_CODE (op0)) == 'e')
5101 /* ... and is unsigned, and its type is smaller than ctype,
5102 then we cannot pass through as widening. */
5103 && ((TYPE_UNSIGNED (TREE_TYPE (op0))
5104 && ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
5105 && TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
5106 && (GET_MODE_SIZE (TYPE_MODE (ctype))
5107 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
5108 /* ... or this is a truncation (t is narrower than op0),
5109 then we cannot pass through this narrowing. */
5110 || (GET_MODE_SIZE (TYPE_MODE (type))
5111 < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0))))
5112 /* ... or signedness changes for division or modulus,
5113 then we cannot pass through this conversion. */
5114 || (code != MULT_EXPR
5115 && (TYPE_UNSIGNED (ctype)
5116 != TYPE_UNSIGNED (TREE_TYPE (op0))))))
5119 /* Pass the constant down and see if we can make a simplification. If
5120 we can, replace this expression with the inner simplification for
5121 possible later conversion to our or some other type. */
5122 if ((t2 = fold_convert (TREE_TYPE (op0), c)) != 0
5123 && TREE_CODE (t2) == INTEGER_CST
5124 && ! TREE_CONSTANT_OVERFLOW (t2)
5125 && (0 != (t1 = extract_muldiv (op0, t2, code,
5127 ? ctype : NULL_TREE))))
5131 case NEGATE_EXPR: case ABS_EXPR:
5132 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
5133 return fold (build1 (tcode, ctype, fold_convert (ctype, t1)));
5136 case MIN_EXPR: case MAX_EXPR:
5137 /* If widening the type changes the signedness, then we can't perform
5138 this optimization as that changes the result. */
5139 if (TYPE_UNSIGNED (ctype) != TYPE_UNSIGNED (type))
5142 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
5143 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0
5144 && (t2 = extract_muldiv (op1, c, code, wide_type)) != 0)
5146 if (tree_int_cst_sgn (c) < 0)
5147 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
5149 return fold (build2 (tcode, ctype, fold_convert (ctype, t1),
5150 fold_convert (ctype, t2)));
5154 case LSHIFT_EXPR: case RSHIFT_EXPR:
5155 /* If the second operand is constant, this is a multiplication
5156 or floor division, by a power of two, so we can treat it that
5157 way unless the multiplier or divisor overflows. Signed
5158 left-shift overflow is implementation-defined rather than
5159 undefined in C90, so do not convert signed left shift into
5161 if (TREE_CODE (op1) == INTEGER_CST
5162 && (tcode == RSHIFT_EXPR || TYPE_UNSIGNED (TREE_TYPE (op0)))
5163 /* const_binop may not detect overflow correctly,
5164 so check for it explicitly here. */
5165 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
5166 && TREE_INT_CST_HIGH (op1) == 0
5167 && 0 != (t1 = fold_convert (ctype,
5168 const_binop (LSHIFT_EXPR,
5171 && ! TREE_OVERFLOW (t1))
5172 return extract_muldiv (build2 (tcode == LSHIFT_EXPR
5173 ? MULT_EXPR : FLOOR_DIV_EXPR,
5174 ctype, fold_convert (ctype, op0), t1),
5175 c, code, wide_type);
5178 case PLUS_EXPR: case MINUS_EXPR:
5179 /* See if we can eliminate the operation on both sides. If we can, we
5180 can return a new PLUS or MINUS. If we can't, the only remaining
5181 cases where we can do anything are if the second operand is a
5183 t1 = extract_muldiv (op0, c, code, wide_type);
5184 t2 = extract_muldiv (op1, c, code, wide_type);
5185 if (t1 != 0 && t2 != 0
5186 && (code == MULT_EXPR
5187 /* If not multiplication, we can only do this if both operands
5188 are divisible by c. */
5189 || (multiple_of_p (ctype, op0, c)
5190 && multiple_of_p (ctype, op1, c))))
5191 return fold (build2 (tcode, ctype, fold_convert (ctype, t1),
5192 fold_convert (ctype, t2)));
5194 /* If this was a subtraction, negate OP1 and set it to be an addition.
5195 This simplifies the logic below. */
5196 if (tcode == MINUS_EXPR)
5197 tcode = PLUS_EXPR, op1 = negate_expr (op1);
5199 if (TREE_CODE (op1) != INTEGER_CST)
5202 /* If either OP1 or C are negative, this optimization is not safe for
5203 some of the division and remainder types while for others we need
5204 to change the code. */
5205 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
5207 if (code == CEIL_DIV_EXPR)
5208 code = FLOOR_DIV_EXPR;
5209 else if (code == FLOOR_DIV_EXPR)
5210 code = CEIL_DIV_EXPR;
5211 else if (code != MULT_EXPR
5212 && code != CEIL_MOD_EXPR && code != FLOOR_MOD_EXPR)
5216 /* If it's a multiply or a division/modulus operation of a multiple
5217 of our constant, do the operation and verify it doesn't overflow. */
5218 if (code == MULT_EXPR
5219 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5221 op1 = const_binop (code, fold_convert (ctype, op1),
5222 fold_convert (ctype, c), 0);
5223 /* We allow the constant to overflow with wrapping semantics. */
5225 || (TREE_OVERFLOW (op1) && ! flag_wrapv))
5231 /* If we have an unsigned type is not a sizetype, we cannot widen
5232 the operation since it will change the result if the original
5233 computation overflowed. */
5234 if (TYPE_UNSIGNED (ctype)
5235 && ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
5239 /* If we were able to eliminate our operation from the first side,
5240 apply our operation to the second side and reform the PLUS. */
5241 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
5242 return fold (build2 (tcode, ctype, fold_convert (ctype, t1), op1));
5244 /* The last case is if we are a multiply. In that case, we can
5245 apply the distributive law to commute the multiply and addition
5246 if the multiplication of the constants doesn't overflow. */
5247 if (code == MULT_EXPR)
5248 return fold (build2 (tcode, ctype,
5249 fold (build2 (code, ctype,
5250 fold_convert (ctype, op0),
5251 fold_convert (ctype, c))),
5257 /* We have a special case here if we are doing something like
5258 (C * 8) % 4 since we know that's zero. */
5259 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
5260 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
5261 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
5262 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5263 return omit_one_operand (type, integer_zero_node, op0);
5265 /* ... fall through ... */
5267 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
5268 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
5269 /* If we can extract our operation from the LHS, do so and return a
5270 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
5271 do something only if the second operand is a constant. */
5273 && (t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
5274 return fold (build2 (tcode, ctype, fold_convert (ctype, t1),
5275 fold_convert (ctype, op1)));
5276 else if (tcode == MULT_EXPR && code == MULT_EXPR
5277 && (t1 = extract_muldiv (op1, c, code, wide_type)) != 0)
5278 return fold (build2 (tcode, ctype, fold_convert (ctype, op0),
5279 fold_convert (ctype, t1)));
5280 else if (TREE_CODE (op1) != INTEGER_CST)
5283 /* If these are the same operation types, we can associate them
5284 assuming no overflow. */
5286 && 0 != (t1 = const_binop (MULT_EXPR, fold_convert (ctype, op1),
5287 fold_convert (ctype, c), 0))
5288 && ! TREE_OVERFLOW (t1))
5289 return fold (build2 (tcode, ctype, fold_convert (ctype, op0), t1));
5291 /* If these operations "cancel" each other, we have the main
5292 optimizations of this pass, which occur when either constant is a
5293 multiple of the other, in which case we replace this with either an
5294 operation or CODE or TCODE.
5296 If we have an unsigned type that is not a sizetype, we cannot do
5297 this since it will change the result if the original computation
5299 if ((! TYPE_UNSIGNED (ctype)
5300 || (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
5302 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
5303 || (tcode == MULT_EXPR
5304 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
5305 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR)))
5307 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5308 return fold (build2 (tcode, ctype, fold_convert (ctype, op0),
5309 fold_convert (ctype,
5310 const_binop (TRUNC_DIV_EXPR,
5312 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
5313 return fold (build2 (code, ctype, fold_convert (ctype, op0),
5314 fold_convert (ctype,
5315 const_binop (TRUNC_DIV_EXPR,
5327 /* Return a node which has the indicated constant VALUE (either 0 or
5328 1), and is of the indicated TYPE. */
5331 constant_boolean_node (int value, tree type)
5333 if (type == integer_type_node)
5334 return value ? integer_one_node : integer_zero_node;
5335 else if (type == boolean_type_node)
5336 return value ? boolean_true_node : boolean_false_node;
5337 else if (TREE_CODE (type) == BOOLEAN_TYPE)
5338 return lang_hooks.truthvalue_conversion (value ? integer_one_node
5339 : integer_zero_node);
5341 return build_int_cst (type, value);
5344 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
5345 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
5346 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
5347 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
5348 COND is the first argument to CODE; otherwise (as in the example
5349 given here), it is the second argument. TYPE is the type of the
5350 original expression. Return NULL_TREE if no simplification is
5354 fold_binary_op_with_conditional_arg (enum tree_code code, tree type,
5355 tree cond, tree arg, int cond_first_p)
5357 tree test, true_value, false_value;
5358 tree lhs = NULL_TREE;
5359 tree rhs = NULL_TREE;
5361 /* This transformation is only worthwhile if we don't have to wrap
5362 arg in a SAVE_EXPR, and the operation can be simplified on atleast
5363 one of the branches once its pushed inside the COND_EXPR. */
5364 if (!TREE_CONSTANT (arg))
5367 if (TREE_CODE (cond) == COND_EXPR)
5369 test = TREE_OPERAND (cond, 0);
5370 true_value = TREE_OPERAND (cond, 1);
5371 false_value = TREE_OPERAND (cond, 2);
5372 /* If this operand throws an expression, then it does not make
5373 sense to try to perform a logical or arithmetic operation
5375 if (VOID_TYPE_P (TREE_TYPE (true_value)))
5377 if (VOID_TYPE_P (TREE_TYPE (false_value)))
5382 tree testtype = TREE_TYPE (cond);
5384 true_value = constant_boolean_node (true, testtype);
5385 false_value = constant_boolean_node (false, testtype);
5389 lhs = fold (cond_first_p ? build2 (code, type, true_value, arg)
5390 : build2 (code, type, arg, true_value));
5392 rhs = fold (cond_first_p ? build2 (code, type, false_value, arg)
5393 : build2 (code, type, arg, false_value));
5395 test = fold (build3 (COND_EXPR, type, test, lhs, rhs));
5396 return fold_convert (type, test);
5400 /* Subroutine of fold() that checks for the addition of +/- 0.0.
5402 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
5403 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
5404 ADDEND is the same as X.
5406 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
5407 and finite. The problematic cases are when X is zero, and its mode
5408 has signed zeros. In the case of rounding towards -infinity,
5409 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
5410 modes, X + 0 is not the same as X because -0 + 0 is 0. */
5413 fold_real_zero_addition_p (tree type, tree addend, int negate)
5415 if (!real_zerop (addend))
5418 /* Don't allow the fold with -fsignaling-nans. */
5419 if (HONOR_SNANS (TYPE_MODE (type)))
5422 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
5423 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
5426 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
5427 if (TREE_CODE (addend) == REAL_CST
5428 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
5431 /* The mode has signed zeros, and we have to honor their sign.
5432 In this situation, there is only one case we can return true for.
5433 X - 0 is the same as X unless rounding towards -infinity is
5435 return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
5438 /* Subroutine of fold() that checks comparisons of built-in math
5439 functions against real constants.
5441 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
5442 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
5443 is the type of the result and ARG0 and ARG1 are the operands of the
5444 comparison. ARG1 must be a TREE_REAL_CST.
5446 The function returns the constant folded tree if a simplification
5447 can be made, and NULL_TREE otherwise. */
5450 fold_mathfn_compare (enum built_in_function fcode, enum tree_code code,
5451 tree type, tree arg0, tree arg1)
5455 if (BUILTIN_SQRT_P (fcode))
5457 tree arg = TREE_VALUE (TREE_OPERAND (arg0, 1));
5458 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg0));
5460 c = TREE_REAL_CST (arg1);
5461 if (REAL_VALUE_NEGATIVE (c))
5463 /* sqrt(x) < y is always false, if y is negative. */
5464 if (code == EQ_EXPR || code == LT_EXPR || code == LE_EXPR)
5465 return omit_one_operand (type, integer_zero_node, arg);
5467 /* sqrt(x) > y is always true, if y is negative and we
5468 don't care about NaNs, i.e. negative values of x. */
5469 if (code == NE_EXPR || !HONOR_NANS (mode))
5470 return omit_one_operand (type, integer_one_node, arg);
5472 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
5473 return fold (build2 (GE_EXPR, type, arg,
5474 build_real (TREE_TYPE (arg), dconst0)));
5476 else if (code == GT_EXPR || code == GE_EXPR)
5480 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
5481 real_convert (&c2, mode, &c2);
5483 if (REAL_VALUE_ISINF (c2))
5485 /* sqrt(x) > y is x == +Inf, when y is very large. */
5486 if (HONOR_INFINITIES (mode))
5487 return fold (build2 (EQ_EXPR, type, arg,
5488 build_real (TREE_TYPE (arg), c2)));
5490 /* sqrt(x) > y is always false, when y is very large
5491 and we don't care about infinities. */
5492 return omit_one_operand (type, integer_zero_node, arg);
5495 /* sqrt(x) > c is the same as x > c*c. */
5496 return fold (build2 (code, type, arg,
5497 build_real (TREE_TYPE (arg), c2)));
5499 else if (code == LT_EXPR || code == LE_EXPR)
5503 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
5504 real_convert (&c2, mode, &c2);
5506 if (REAL_VALUE_ISINF (c2))
5508 /* sqrt(x) < y is always true, when y is a very large
5509 value and we don't care about NaNs or Infinities. */
5510 if (! HONOR_NANS (mode) && ! HONOR_INFINITIES (mode))
5511 return omit_one_operand (type, integer_one_node, arg);
5513 /* sqrt(x) < y is x != +Inf when y is very large and we
5514 don't care about NaNs. */
5515 if (! HONOR_NANS (mode))
5516 return fold (build2 (NE_EXPR, type, arg,
5517 build_real (TREE_TYPE (arg), c2)));
5519 /* sqrt(x) < y is x >= 0 when y is very large and we
5520 don't care about Infinities. */
5521 if (! HONOR_INFINITIES (mode))
5522 return fold (build2 (GE_EXPR, type, arg,
5523 build_real (TREE_TYPE (arg), dconst0)));
5525 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
5526 if (lang_hooks.decls.global_bindings_p () != 0
5527 || CONTAINS_PLACEHOLDER_P (arg))
5530 arg = save_expr (arg);
5531 return fold (build2 (TRUTH_ANDIF_EXPR, type,
5532 fold (build2 (GE_EXPR, type, arg,
5533 build_real (TREE_TYPE (arg),
5535 fold (build2 (NE_EXPR, type, arg,
5536 build_real (TREE_TYPE (arg),
5540 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
5541 if (! HONOR_NANS (mode))
5542 return fold (build2 (code, type, arg,
5543 build_real (TREE_TYPE (arg), c2)));
5545 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
5546 if (lang_hooks.decls.global_bindings_p () == 0
5547 && ! CONTAINS_PLACEHOLDER_P (arg))
5549 arg = save_expr (arg);
5550 return fold (build2 (TRUTH_ANDIF_EXPR, type,
5551 fold (build2 (GE_EXPR, type, arg,
5552 build_real (TREE_TYPE (arg),
5554 fold (build2 (code, type, arg,
5555 build_real (TREE_TYPE (arg),
5564 /* Subroutine of fold() that optimizes comparisons against Infinities,
5565 either +Inf or -Inf.
5567 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
5568 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
5569 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
5571 The function returns the constant folded tree if a simplification
5572 can be made, and NULL_TREE otherwise. */
5575 fold_inf_compare (enum tree_code code, tree type, tree arg0, tree arg1)
5577 enum machine_mode mode;
5578 REAL_VALUE_TYPE max;
5582 mode = TYPE_MODE (TREE_TYPE (arg0));
5584 /* For negative infinity swap the sense of the comparison. */
5585 neg = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1));
5587 code = swap_tree_comparison (code);
5592 /* x > +Inf is always false, if with ignore sNANs. */
5593 if (HONOR_SNANS (mode))
5595 return omit_one_operand (type, integer_zero_node, arg0);
5598 /* x <= +Inf is always true, if we don't case about NaNs. */
5599 if (! HONOR_NANS (mode))
5600 return omit_one_operand (type, integer_one_node, arg0);
5602 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
5603 if (lang_hooks.decls.global_bindings_p () == 0
5604 && ! CONTAINS_PLACEHOLDER_P (arg0))
5606 arg0 = save_expr (arg0);
5607 return fold (build2 (EQ_EXPR, type, arg0, arg0));
5613 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
5614 real_maxval (&max, neg, mode);
5615 return fold (build2 (neg ? LT_EXPR : GT_EXPR, type,
5616 arg0, build_real (TREE_TYPE (arg0), max)));
5619 /* x < +Inf is always equal to x <= DBL_MAX. */
5620 real_maxval (&max, neg, mode);
5621 return fold (build2 (neg ? GE_EXPR : LE_EXPR, type,
5622 arg0, build_real (TREE_TYPE (arg0), max)));
5625 /* x != +Inf is always equal to !(x > DBL_MAX). */
5626 real_maxval (&max, neg, mode);
5627 if (! HONOR_NANS (mode))
5628 return fold (build2 (neg ? GE_EXPR : LE_EXPR, type,
5629 arg0, build_real (TREE_TYPE (arg0), max)));
5631 /* The transformation below creates non-gimple code and thus is
5632 not appropriate if we are in gimple form. */
5636 temp = fold (build2 (neg ? LT_EXPR : GT_EXPR, type,
5637 arg0, build_real (TREE_TYPE (arg0), max)));
5638 return fold (build1 (TRUTH_NOT_EXPR, type, temp));
5647 /* Subroutine of fold() that optimizes comparisons of a division by
5648 a nonzero integer constant against an integer constant, i.e.
5651 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
5652 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
5653 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
5655 The function returns the constant folded tree if a simplification
5656 can be made, and NULL_TREE otherwise. */
5659 fold_div_compare (enum tree_code code, tree type, tree arg0, tree arg1)
5661 tree prod, tmp, hi, lo;
5662 tree arg00 = TREE_OPERAND (arg0, 0);
5663 tree arg01 = TREE_OPERAND (arg0, 1);
5664 unsigned HOST_WIDE_INT lpart;
5665 HOST_WIDE_INT hpart;
5668 /* We have to do this the hard way to detect unsigned overflow.
5669 prod = int_const_binop (MULT_EXPR, arg01, arg1, 0); */
5670 overflow = mul_double (TREE_INT_CST_LOW (arg01),
5671 TREE_INT_CST_HIGH (arg01),
5672 TREE_INT_CST_LOW (arg1),
5673 TREE_INT_CST_HIGH (arg1), &lpart, &hpart);
5674 prod = build_int_cst_wide (TREE_TYPE (arg00), lpart, hpart);
5675 prod = force_fit_type (prod, -1, overflow, false);
5677 if (TYPE_UNSIGNED (TREE_TYPE (arg0)))
5679 tmp = int_const_binop (MINUS_EXPR, arg01, integer_one_node, 0);
5682 /* Likewise hi = int_const_binop (PLUS_EXPR, prod, tmp, 0). */
5683 overflow = add_double (TREE_INT_CST_LOW (prod),
5684 TREE_INT_CST_HIGH (prod),
5685 TREE_INT_CST_LOW (tmp),
5686 TREE_INT_CST_HIGH (tmp),
5688 hi = build_int_cst_wide (TREE_TYPE (arg00), lpart, hpart);
5689 hi = force_fit_type (hi, -1, overflow | TREE_OVERFLOW (prod),
5690 TREE_CONSTANT_OVERFLOW (prod));
5692 else if (tree_int_cst_sgn (arg01) >= 0)
5694 tmp = int_const_binop (MINUS_EXPR, arg01, integer_one_node, 0);
5695 switch (tree_int_cst_sgn (arg1))
5698 lo = int_const_binop (MINUS_EXPR, prod, tmp, 0);
5703 lo = fold_negate_const (tmp, TREE_TYPE (arg0));
5708 hi = int_const_binop (PLUS_EXPR, prod, tmp, 0);
5718 tmp = int_const_binop (PLUS_EXPR, arg01, integer_one_node, 0);
5719 switch (tree_int_cst_sgn (arg1))
5722 hi = int_const_binop (MINUS_EXPR, prod, tmp, 0);
5727 hi = fold_negate_const (tmp, TREE_TYPE (arg0));
5732 lo = int_const_binop (PLUS_EXPR, prod, tmp, 0);
5744 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
5745 return omit_one_operand (type, integer_zero_node, arg00);
5746 if (TREE_OVERFLOW (hi))
5747 return fold (build2 (GE_EXPR, type, arg00, lo));
5748 if (TREE_OVERFLOW (lo))
5749 return fold (build2 (LE_EXPR, type, arg00, hi));
5750 return build_range_check (type, arg00, 1, lo, hi);
5753 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
5754 return omit_one_operand (type, integer_one_node, arg00);
5755 if (TREE_OVERFLOW (hi))
5756 return fold (build2 (LT_EXPR, type, arg00, lo));
5757 if (TREE_OVERFLOW (lo))
5758 return fold (build2 (GT_EXPR, type, arg00, hi));
5759 return build_range_check (type, arg00, 0, lo, hi);
5762 if (TREE_OVERFLOW (lo))
5763 return omit_one_operand (type, integer_zero_node, arg00);
5764 return fold (build2 (LT_EXPR, type, arg00, lo));
5767 if (TREE_OVERFLOW (hi))
5768 return omit_one_operand (type, integer_one_node, arg00);
5769 return fold (build2 (LE_EXPR, type, arg00, hi));
5772 if (TREE_OVERFLOW (hi))
5773 return omit_one_operand (type, integer_zero_node, arg00);
5774 return fold (build2 (GT_EXPR, type, arg00, hi));
5777 if (TREE_OVERFLOW (lo))
5778 return omit_one_operand (type, integer_one_node, arg00);
5779 return fold (build2 (GE_EXPR, type, arg00, lo));
5789 /* If CODE with arguments ARG0 and ARG1 represents a single bit
5790 equality/inequality test, then return a simplified form of
5791 the test using shifts and logical operations. Otherwise return
5792 NULL. TYPE is the desired result type. */
5795 fold_single_bit_test (enum tree_code code, tree arg0, tree arg1,
5798 /* If this is a TRUTH_NOT_EXPR, it may have a single bit test inside
5800 if (code == TRUTH_NOT_EXPR)
5802 code = TREE_CODE (arg0);
5803 if (code != NE_EXPR && code != EQ_EXPR)
5806 /* Extract the arguments of the EQ/NE. */
5807 arg1 = TREE_OPERAND (arg0, 1);
5808 arg0 = TREE_OPERAND (arg0, 0);
5810 /* This requires us to invert the code. */
5811 code = (code == EQ_EXPR ? NE_EXPR : EQ_EXPR);
5814 /* If this is testing a single bit, we can optimize the test. */
5815 if ((code == NE_EXPR || code == EQ_EXPR)
5816 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
5817 && integer_pow2p (TREE_OPERAND (arg0, 1)))
5819 tree inner = TREE_OPERAND (arg0, 0);
5820 tree type = TREE_TYPE (arg0);
5821 int bitnum = tree_log2 (TREE_OPERAND (arg0, 1));
5822 enum machine_mode operand_mode = TYPE_MODE (type);
5824 tree signed_type, unsigned_type, intermediate_type;
5827 /* If we have (A & C) != 0 where C is the sign bit of A, convert
5828 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
5829 arg00 = sign_bit_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
5830 if (arg00 != NULL_TREE
5831 /* This is only a win if casting to a signed type is cheap,
5832 i.e. when arg00's type is not a partial mode. */
5833 && TYPE_PRECISION (TREE_TYPE (arg00))
5834 == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg00))))
5836 tree stype = lang_hooks.types.signed_type (TREE_TYPE (arg00));
5837 return fold (build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
5838 result_type, fold_convert (stype, arg00),
5839 fold_convert (stype, integer_zero_node)));
5842 /* Otherwise we have (A & C) != 0 where C is a single bit,
5843 convert that into ((A >> C2) & 1). Where C2 = log2(C).
5844 Similarly for (A & C) == 0. */
5846 /* If INNER is a right shift of a constant and it plus BITNUM does
5847 not overflow, adjust BITNUM and INNER. */
5848 if (TREE_CODE (inner) == RSHIFT_EXPR
5849 && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST
5850 && TREE_INT_CST_HIGH (TREE_OPERAND (inner, 1)) == 0
5851 && bitnum < TYPE_PRECISION (type)
5852 && 0 > compare_tree_int (TREE_OPERAND (inner, 1),
5853 bitnum - TYPE_PRECISION (type)))
5855 bitnum += TREE_INT_CST_LOW (TREE_OPERAND (inner, 1));
5856 inner = TREE_OPERAND (inner, 0);
5859 /* If we are going to be able to omit the AND below, we must do our
5860 operations as unsigned. If we must use the AND, we have a choice.
5861 Normally unsigned is faster, but for some machines signed is. */
5862 #ifdef LOAD_EXTEND_OP
5863 ops_unsigned = (LOAD_EXTEND_OP (operand_mode) == SIGN_EXTEND ? 0 : 1);
5868 signed_type = lang_hooks.types.type_for_mode (operand_mode, 0);
5869 unsigned_type = lang_hooks.types.type_for_mode (operand_mode, 1);
5870 intermediate_type = ops_unsigned ? unsigned_type : signed_type;
5871 inner = fold_convert (intermediate_type, inner);
5874 inner = build2 (RSHIFT_EXPR, intermediate_type,
5875 inner, size_int (bitnum));
5877 if (code == EQ_EXPR)
5878 inner = fold (build2 (BIT_XOR_EXPR, intermediate_type,
5879 inner, integer_one_node));
5881 /* Put the AND last so it can combine with more things. */
5882 inner = build2 (BIT_AND_EXPR, intermediate_type,
5883 inner, integer_one_node);
5885 /* Make sure to return the proper type. */
5886 inner = fold_convert (result_type, inner);
5893 /* Check whether we are allowed to reorder operands arg0 and arg1,
5894 such that the evaluation of arg1 occurs before arg0. */
5897 reorder_operands_p (tree arg0, tree arg1)
5899 if (! flag_evaluation_order)
5901 if (TREE_CONSTANT (arg0) || TREE_CONSTANT (arg1))
5903 return ! TREE_SIDE_EFFECTS (arg0)
5904 && ! TREE_SIDE_EFFECTS (arg1);
5907 /* Test whether it is preferable two swap two operands, ARG0 and
5908 ARG1, for example because ARG0 is an integer constant and ARG1
5909 isn't. If REORDER is true, only recommend swapping if we can
5910 evaluate the operands in reverse order. */
5913 tree_swap_operands_p (tree arg0, tree arg1, bool reorder)
5915 STRIP_SIGN_NOPS (arg0);
5916 STRIP_SIGN_NOPS (arg1);
5918 if (TREE_CODE (arg1) == INTEGER_CST)
5920 if (TREE_CODE (arg0) == INTEGER_CST)
5923 if (TREE_CODE (arg1) == REAL_CST)
5925 if (TREE_CODE (arg0) == REAL_CST)
5928 if (TREE_CODE (arg1) == COMPLEX_CST)
5930 if (TREE_CODE (arg0) == COMPLEX_CST)
5933 if (TREE_CONSTANT (arg1))
5935 if (TREE_CONSTANT (arg0))
5941 if (reorder && flag_evaluation_order
5942 && (TREE_SIDE_EFFECTS (arg0) || TREE_SIDE_EFFECTS (arg1)))
5950 if (reorder && flag_evaluation_order
5951 && (TREE_SIDE_EFFECTS (arg0) || TREE_SIDE_EFFECTS (arg1)))
5959 /* It is preferable to swap two SSA_NAME to ensure a canonical form
5960 for commutative and comparison operators. Ensuring a canonical
5961 form allows the optimizers to find additional redundancies without
5962 having to explicitly check for both orderings. */
5963 if (TREE_CODE (arg0) == SSA_NAME
5964 && TREE_CODE (arg1) == SSA_NAME
5965 && SSA_NAME_VERSION (arg0) > SSA_NAME_VERSION (arg1))
5971 /* Perform constant folding and related simplification of EXPR.
5972 The related simplifications include x*1 => x, x*0 => 0, etc.,
5973 and application of the associative law.
5974 NOP_EXPR conversions may be removed freely (as long as we
5975 are careful not to change the type of the overall expression).
5976 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
5977 but we can constant-fold them if they have constant operands. */
5979 #ifdef ENABLE_FOLD_CHECKING
5980 # define fold(x) fold_1 (x)
5981 static tree fold_1 (tree);
5987 const tree t = expr;
5988 const tree type = TREE_TYPE (expr);
5989 tree t1 = NULL_TREE;
5991 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
5992 enum tree_code code = TREE_CODE (t);
5993 int kind = TREE_CODE_CLASS (code);
5995 /* WINS will be nonzero when the switch is done
5996 if all operands are constant. */
5999 /* Return right away if a constant. */
6003 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
6007 /* Special case for conversion ops that can have fixed point args. */
6008 arg0 = TREE_OPERAND (t, 0);
6010 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
6012 STRIP_SIGN_NOPS (arg0);
6014 if (arg0 != 0 && TREE_CODE (arg0) == COMPLEX_CST)
6015 subop = TREE_REALPART (arg0);
6019 if (subop != 0 && TREE_CODE (subop) != INTEGER_CST
6020 && TREE_CODE (subop) != REAL_CST)
6021 /* Note that TREE_CONSTANT isn't enough:
6022 static var addresses are constant but we can't
6023 do arithmetic on them. */
6026 else if (IS_EXPR_CODE_CLASS (kind))
6028 int len = first_rtl_op (code);
6030 for (i = 0; i < len; i++)
6032 tree op = TREE_OPERAND (t, i);
6036 continue; /* Valid for CALL_EXPR, at least. */
6038 /* Strip any conversions that don't change the mode. This is
6039 safe for every expression, except for a comparison expression
6040 because its signedness is derived from its operands. So, in
6041 the latter case, only strip conversions that don't change the
6044 Note that this is done as an internal manipulation within the
6045 constant folder, in order to find the simplest representation
6046 of the arguments so that their form can be studied. In any
6047 cases, the appropriate type conversions should be put back in
6048 the tree that will get out of the constant folder. */
6050 STRIP_SIGN_NOPS (op);
6054 if (TREE_CODE (op) == COMPLEX_CST)
6055 subop = TREE_REALPART (op);
6059 if (TREE_CODE (subop) != INTEGER_CST
6060 && TREE_CODE (subop) != REAL_CST)
6061 /* Note that TREE_CONSTANT isn't enough:
6062 static var addresses are constant but we can't
6063 do arithmetic on them. */
6073 /* If this is a commutative operation, and ARG0 is a constant, move it
6074 to ARG1 to reduce the number of tests below. */
6075 if (commutative_tree_code (code)
6076 && tree_swap_operands_p (arg0, arg1, true))
6077 return fold (build2 (code, type, TREE_OPERAND (t, 1),
6078 TREE_OPERAND (t, 0)));
6080 /* Now WINS is set as described above,
6081 ARG0 is the first operand of EXPR,
6082 and ARG1 is the second operand (if it has more than one operand).
6084 First check for cases where an arithmetic operation is applied to a
6085 compound, conditional, or comparison operation. Push the arithmetic
6086 operation inside the compound or conditional to see if any folding
6087 can then be done. Convert comparison to conditional for this purpose.
6088 The also optimizes non-constant cases that used to be done in
6091 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
6092 one of the operands is a comparison and the other is a comparison, a
6093 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
6094 code below would make the expression more complex. Change it to a
6095 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
6096 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
6098 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
6099 || code == EQ_EXPR || code == NE_EXPR)
6100 && ((truth_value_p (TREE_CODE (arg0))
6101 && (truth_value_p (TREE_CODE (arg1))
6102 || (TREE_CODE (arg1) == BIT_AND_EXPR
6103 && integer_onep (TREE_OPERAND (arg1, 1)))))
6104 || (truth_value_p (TREE_CODE (arg1))
6105 && (truth_value_p (TREE_CODE (arg0))
6106 || (TREE_CODE (arg0) == BIT_AND_EXPR
6107 && integer_onep (TREE_OPERAND (arg0, 1)))))))
6109 tem = fold (build2 (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
6110 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
6112 type, fold_convert (boolean_type_node, arg0),
6113 fold_convert (boolean_type_node, arg1)));
6115 if (code == EQ_EXPR)
6116 tem = invert_truthvalue (tem);
6121 if (TREE_CODE_CLASS (code) == '1')
6123 if (TREE_CODE (arg0) == COMPOUND_EXPR)
6124 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
6125 fold (build1 (code, type, TREE_OPERAND (arg0, 1))));
6126 else if (TREE_CODE (arg0) == COND_EXPR)
6128 tree arg01 = TREE_OPERAND (arg0, 1);
6129 tree arg02 = TREE_OPERAND (arg0, 2);
6130 if (! VOID_TYPE_P (TREE_TYPE (arg01)))
6131 arg01 = fold (build1 (code, type, arg01));
6132 if (! VOID_TYPE_P (TREE_TYPE (arg02)))
6133 arg02 = fold (build1 (code, type, arg02));
6134 tem = fold (build3 (COND_EXPR, type, TREE_OPERAND (arg0, 0),
6137 /* If this was a conversion, and all we did was to move into
6138 inside the COND_EXPR, bring it back out. But leave it if
6139 it is a conversion from integer to integer and the
6140 result precision is no wider than a word since such a
6141 conversion is cheap and may be optimized away by combine,
6142 while it couldn't if it were outside the COND_EXPR. Then return
6143 so we don't get into an infinite recursion loop taking the
6144 conversion out and then back in. */
6146 if ((code == NOP_EXPR || code == CONVERT_EXPR
6147 || code == NON_LVALUE_EXPR)
6148 && TREE_CODE (tem) == COND_EXPR
6149 && TREE_CODE (TREE_OPERAND (tem, 1)) == code
6150 && TREE_CODE (TREE_OPERAND (tem, 2)) == code
6151 && ! VOID_TYPE_P (TREE_OPERAND (tem, 1))
6152 && ! VOID_TYPE_P (TREE_OPERAND (tem, 2))
6153 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))
6154 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 2), 0)))
6155 && ! (INTEGRAL_TYPE_P (TREE_TYPE (tem))
6157 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))))
6158 && TYPE_PRECISION (TREE_TYPE (tem)) <= BITS_PER_WORD))
6159 tem = build1 (code, type,
6161 TREE_TYPE (TREE_OPERAND
6162 (TREE_OPERAND (tem, 1), 0)),
6163 TREE_OPERAND (tem, 0),
6164 TREE_OPERAND (TREE_OPERAND (tem, 1), 0),
6165 TREE_OPERAND (TREE_OPERAND (tem, 2), 0)));
6168 else if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<')
6170 if (TREE_CODE (type) == BOOLEAN_TYPE)
6172 arg0 = copy_node (arg0);
6173 TREE_TYPE (arg0) = type;
6176 else if (TREE_CODE (type) != INTEGER_TYPE)
6177 return fold (build3 (COND_EXPR, type, arg0,
6178 fold (build1 (code, type,
6180 fold (build1 (code, type,
6181 integer_zero_node))));
6184 else if (TREE_CODE_CLASS (code) == '<'
6185 && TREE_CODE (arg0) == COMPOUND_EXPR)
6186 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
6187 fold (build2 (code, type, TREE_OPERAND (arg0, 1), arg1)));
6188 else if (TREE_CODE_CLASS (code) == '<'
6189 && TREE_CODE (arg1) == COMPOUND_EXPR)
6190 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
6191 fold (build2 (code, type, arg0, TREE_OPERAND (arg1, 1))));
6192 else if (TREE_CODE_CLASS (code) == '2'
6193 || TREE_CODE_CLASS (code) == '<')
6195 if (TREE_CODE (arg0) == COMPOUND_EXPR)
6196 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
6197 fold (build2 (code, type, TREE_OPERAND (arg0, 1),
6199 if (TREE_CODE (arg1) == COMPOUND_EXPR
6200 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
6201 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
6202 fold (build2 (code, type,
6203 arg0, TREE_OPERAND (arg1, 1))));
6205 if (TREE_CODE (arg0) == COND_EXPR
6206 || TREE_CODE_CLASS (TREE_CODE (arg0)) == '<')
6208 tem = fold_binary_op_with_conditional_arg (code, type, arg0, arg1,
6209 /*cond_first_p=*/1);
6210 if (tem != NULL_TREE)
6214 if (TREE_CODE (arg1) == COND_EXPR
6215 || TREE_CODE_CLASS (TREE_CODE (arg1)) == '<')
6217 tem = fold_binary_op_with_conditional_arg (code, type, arg1, arg0,
6218 /*cond_first_p=*/0);
6219 if (tem != NULL_TREE)
6227 return fold (DECL_INITIAL (t));
6232 case FIX_TRUNC_EXPR:
6234 case FIX_FLOOR_EXPR:
6235 case FIX_ROUND_EXPR:
6236 if (TREE_TYPE (TREE_OPERAND (t, 0)) == type)
6237 return TREE_OPERAND (t, 0);
6239 /* Handle cases of two conversions in a row. */
6240 if (TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
6241 || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR)
6243 tree inside_type = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
6244 tree inter_type = TREE_TYPE (TREE_OPERAND (t, 0));
6245 int inside_int = INTEGRAL_TYPE_P (inside_type);
6246 int inside_ptr = POINTER_TYPE_P (inside_type);
6247 int inside_float = FLOAT_TYPE_P (inside_type);
6248 unsigned int inside_prec = TYPE_PRECISION (inside_type);
6249 int inside_unsignedp = TYPE_UNSIGNED (inside_type);
6250 int inter_int = INTEGRAL_TYPE_P (inter_type);
6251 int inter_ptr = POINTER_TYPE_P (inter_type);
6252 int inter_float = FLOAT_TYPE_P (inter_type);
6253 unsigned int inter_prec = TYPE_PRECISION (inter_type);
6254 int inter_unsignedp = TYPE_UNSIGNED (inter_type);
6255 int final_int = INTEGRAL_TYPE_P (type);
6256 int final_ptr = POINTER_TYPE_P (type);
6257 int final_float = FLOAT_TYPE_P (type);
6258 unsigned int final_prec = TYPE_PRECISION (type);
6259 int final_unsignedp = TYPE_UNSIGNED (type);
6261 /* In addition to the cases of two conversions in a row
6262 handled below, if we are converting something to its own
6263 type via an object of identical or wider precision, neither
6264 conversion is needed. */
6265 if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (type)
6266 && ((inter_int && final_int) || (inter_float && final_float))
6267 && inter_prec >= final_prec)
6268 return fold (build1 (code, type,
6269 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
6271 /* Likewise, if the intermediate and final types are either both
6272 float or both integer, we don't need the middle conversion if
6273 it is wider than the final type and doesn't change the signedness
6274 (for integers). Avoid this if the final type is a pointer
6275 since then we sometimes need the inner conversion. Likewise if
6276 the outer has a precision not equal to the size of its mode. */
6277 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
6278 || (inter_float && inside_float))
6279 && inter_prec >= inside_prec
6280 && (inter_float || inter_unsignedp == inside_unsignedp)
6281 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
6282 && TYPE_MODE (type) == TYPE_MODE (inter_type))
6284 return fold (build1 (code, type,
6285 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
6287 /* If we have a sign-extension of a zero-extended value, we can
6288 replace that by a single zero-extension. */
6289 if (inside_int && inter_int && final_int
6290 && inside_prec < inter_prec && inter_prec < final_prec
6291 && inside_unsignedp && !inter_unsignedp)
6292 return fold (build1 (code, type,
6293 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
6295 /* Two conversions in a row are not needed unless:
6296 - some conversion is floating-point (overstrict for now), or
6297 - the intermediate type is narrower than both initial and
6299 - the intermediate type and innermost type differ in signedness,
6300 and the outermost type is wider than the intermediate, or
6301 - the initial type is a pointer type and the precisions of the
6302 intermediate and final types differ, or
6303 - the final type is a pointer type and the precisions of the
6304 initial and intermediate types differ. */
6305 if (! inside_float && ! inter_float && ! final_float
6306 && (inter_prec > inside_prec || inter_prec > final_prec)
6307 && ! (inside_int && inter_int
6308 && inter_unsignedp != inside_unsignedp
6309 && inter_prec < final_prec)
6310 && ((inter_unsignedp && inter_prec > inside_prec)
6311 == (final_unsignedp && final_prec > inter_prec))
6312 && ! (inside_ptr && inter_prec != final_prec)
6313 && ! (final_ptr && inside_prec != inter_prec)
6314 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
6315 && TYPE_MODE (type) == TYPE_MODE (inter_type))
6317 return fold (build1 (code, type,
6318 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
6321 if (TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR
6322 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t, 0), 1))
6323 /* Detect assigning a bitfield. */
6324 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) == COMPONENT_REF
6325 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 1))))
6327 /* Don't leave an assignment inside a conversion
6328 unless assigning a bitfield. */
6329 tree prev = TREE_OPERAND (t, 0);
6330 tem = copy_node (t);
6331 TREE_OPERAND (tem, 0) = TREE_OPERAND (prev, 1);
6332 /* First do the assignment, then return converted constant. */
6333 tem = build2 (COMPOUND_EXPR, TREE_TYPE (tem), prev, fold (tem));
6334 TREE_NO_WARNING (tem) = 1;
6335 TREE_USED (tem) = 1;
6339 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
6340 constants (if x has signed type, the sign bit cannot be set
6341 in c). This folds extension into the BIT_AND_EXPR. */
6342 if (INTEGRAL_TYPE_P (type)
6343 && TREE_CODE (type) != BOOLEAN_TYPE
6344 && TREE_CODE (TREE_OPERAND (t, 0)) == BIT_AND_EXPR
6345 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 1)) == INTEGER_CST)
6347 tree and = TREE_OPERAND (t, 0);
6348 tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
6351 if (TYPE_UNSIGNED (TREE_TYPE (and))
6352 || (TYPE_PRECISION (type)
6353 <= TYPE_PRECISION (TREE_TYPE (and))))
6355 else if (TYPE_PRECISION (TREE_TYPE (and1))
6356 <= HOST_BITS_PER_WIDE_INT
6357 && host_integerp (and1, 1))
6359 unsigned HOST_WIDE_INT cst;
6361 cst = tree_low_cst (and1, 1);
6362 cst &= (HOST_WIDE_INT) -1
6363 << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
6364 change = (cst == 0);
6365 #ifdef LOAD_EXTEND_OP
6367 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
6370 tree uns = lang_hooks.types.unsigned_type (TREE_TYPE (and0));
6371 and0 = fold_convert (uns, and0);
6372 and1 = fold_convert (uns, and1);
6377 return fold (build2 (BIT_AND_EXPR, type,
6378 fold_convert (type, and0),
6379 fold_convert (type, and1)));
6382 /* Convert (T1)((T2)X op Y) into (T1)X op Y, for pointer types T1 and
6383 T2 being pointers to types of the same size. */
6384 if (POINTER_TYPE_P (TREE_TYPE (t))
6385 && TREE_CODE_CLASS (TREE_CODE (arg0)) == '2'
6386 && TREE_CODE (TREE_OPERAND (arg0, 0)) == NOP_EXPR
6387 && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 0))))
6389 tree arg00 = TREE_OPERAND (arg0, 0);
6390 tree t0 = TREE_TYPE (t);
6391 tree t1 = TREE_TYPE (arg00);
6392 tree tt0 = TREE_TYPE (t0);
6393 tree tt1 = TREE_TYPE (t1);
6394 tree s0 = TYPE_SIZE (tt0);
6395 tree s1 = TYPE_SIZE (tt1);
6397 if (s0 && s1 && operand_equal_p (s0, s1, OEP_ONLY_CONST))
6398 return build2 (TREE_CODE (arg0), t0, fold_convert (t0, arg00),
6399 TREE_OPERAND (arg0, 1));
6402 tem = fold_convert_const (code, type, arg0);
6403 return tem ? tem : t;
6405 case VIEW_CONVERT_EXPR:
6406 if (TREE_CODE (TREE_OPERAND (t, 0)) == VIEW_CONVERT_EXPR)
6407 return build1 (VIEW_CONVERT_EXPR, type,
6408 TREE_OPERAND (TREE_OPERAND (t, 0), 0));
6412 if (TREE_CODE (arg0) == CONSTRUCTOR
6413 && ! type_contains_placeholder_p (TREE_TYPE (arg0)))
6415 tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0));
6417 return TREE_VALUE (m);
6422 if (TREE_CONSTANT (t) != wins)
6424 tem = copy_node (t);
6425 TREE_CONSTANT (tem) = wins;
6426 TREE_INVARIANT (tem) = wins;
6432 if (negate_expr_p (arg0))
6433 return fold_convert (type, negate_expr (arg0));
6437 if (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST)
6438 return fold_abs_const (arg0, type);
6439 else if (TREE_CODE (arg0) == NEGATE_EXPR)
6440 return fold (build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0)));
6441 /* Convert fabs((double)float) into (double)fabsf(float). */
6442 else if (TREE_CODE (arg0) == NOP_EXPR
6443 && TREE_CODE (type) == REAL_TYPE)
6445 tree targ0 = strip_float_extensions (arg0);
6447 return fold_convert (type, fold (build1 (ABS_EXPR,
6451 else if (tree_expr_nonnegative_p (arg0))
6456 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
6457 return fold_convert (type, arg0);
6458 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
6459 return build2 (COMPLEX_EXPR, type,
6460 TREE_OPERAND (arg0, 0),
6461 negate_expr (TREE_OPERAND (arg0, 1)));
6462 else if (TREE_CODE (arg0) == COMPLEX_CST)
6463 return build_complex (type, TREE_REALPART (arg0),
6464 negate_expr (TREE_IMAGPART (arg0)));
6465 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
6466 return fold (build2 (TREE_CODE (arg0), type,
6467 fold (build1 (CONJ_EXPR, type,
6468 TREE_OPERAND (arg0, 0))),
6469 fold (build1 (CONJ_EXPR, type,
6470 TREE_OPERAND (arg0, 1)))));
6471 else if (TREE_CODE (arg0) == CONJ_EXPR)
6472 return TREE_OPERAND (arg0, 0);
6476 if (TREE_CODE (arg0) == INTEGER_CST)
6477 return fold_not_const (arg0, type);
6478 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
6479 return TREE_OPERAND (arg0, 0);
6483 /* A + (-B) -> A - B */
6484 if (TREE_CODE (arg1) == NEGATE_EXPR)
6485 return fold (build2 (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
6486 /* (-A) + B -> B - A */
6487 if (TREE_CODE (arg0) == NEGATE_EXPR
6488 && reorder_operands_p (TREE_OPERAND (arg0, 0), arg1))
6489 return fold (build2 (MINUS_EXPR, type, arg1, TREE_OPERAND (arg0, 0)));
6490 if (! FLOAT_TYPE_P (type))
6492 if (integer_zerop (arg1))
6493 return non_lvalue (fold_convert (type, arg0));
6495 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
6496 with a constant, and the two constants have no bits in common,
6497 we should treat this as a BIT_IOR_EXPR since this may produce more
6499 if (TREE_CODE (arg0) == BIT_AND_EXPR
6500 && TREE_CODE (arg1) == BIT_AND_EXPR
6501 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6502 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
6503 && integer_zerop (const_binop (BIT_AND_EXPR,
6504 TREE_OPERAND (arg0, 1),
6505 TREE_OPERAND (arg1, 1), 0)))
6507 code = BIT_IOR_EXPR;
6511 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
6512 (plus (plus (mult) (mult)) (foo)) so that we can
6513 take advantage of the factoring cases below. */
6514 if ((TREE_CODE (arg0) == PLUS_EXPR
6515 && TREE_CODE (arg1) == MULT_EXPR)
6516 || (TREE_CODE (arg1) == PLUS_EXPR
6517 && TREE_CODE (arg0) == MULT_EXPR))
6519 tree parg0, parg1, parg, marg;
6521 if (TREE_CODE (arg0) == PLUS_EXPR)
6522 parg = arg0, marg = arg1;
6524 parg = arg1, marg = arg0;
6525 parg0 = TREE_OPERAND (parg, 0);
6526 parg1 = TREE_OPERAND (parg, 1);
6530 if (TREE_CODE (parg0) == MULT_EXPR
6531 && TREE_CODE (parg1) != MULT_EXPR)
6532 return fold (build2 (PLUS_EXPR, type,
6533 fold (build2 (PLUS_EXPR, type,
6534 fold_convert (type, parg0),
6535 fold_convert (type, marg))),
6536 fold_convert (type, parg1)));
6537 if (TREE_CODE (parg0) != MULT_EXPR
6538 && TREE_CODE (parg1) == MULT_EXPR)
6539 return fold (build2 (PLUS_EXPR, type,
6540 fold (build2 (PLUS_EXPR, type,
6541 fold_convert (type, parg1),
6542 fold_convert (type, marg))),
6543 fold_convert (type, parg0)));
6546 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR)
6548 tree arg00, arg01, arg10, arg11;
6549 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
6551 /* (A * C) + (B * C) -> (A+B) * C.
6552 We are most concerned about the case where C is a constant,
6553 but other combinations show up during loop reduction. Since
6554 it is not difficult, try all four possibilities. */
6556 arg00 = TREE_OPERAND (arg0, 0);
6557 arg01 = TREE_OPERAND (arg0, 1);
6558 arg10 = TREE_OPERAND (arg1, 0);
6559 arg11 = TREE_OPERAND (arg1, 1);
6562 if (operand_equal_p (arg01, arg11, 0))
6563 same = arg01, alt0 = arg00, alt1 = arg10;
6564 else if (operand_equal_p (arg00, arg10, 0))
6565 same = arg00, alt0 = arg01, alt1 = arg11;
6566 else if (operand_equal_p (arg00, arg11, 0))
6567 same = arg00, alt0 = arg01, alt1 = arg10;
6568 else if (operand_equal_p (arg01, arg10, 0))
6569 same = arg01, alt0 = arg00, alt1 = arg11;
6571 /* No identical multiplicands; see if we can find a common
6572 power-of-two factor in non-power-of-two multiplies. This
6573 can help in multi-dimensional array access. */
6574 else if (TREE_CODE (arg01) == INTEGER_CST
6575 && TREE_CODE (arg11) == INTEGER_CST
6576 && TREE_INT_CST_HIGH (arg01) == 0
6577 && TREE_INT_CST_HIGH (arg11) == 0)
6579 HOST_WIDE_INT int01, int11, tmp;
6580 int01 = TREE_INT_CST_LOW (arg01);
6581 int11 = TREE_INT_CST_LOW (arg11);
6583 /* Move min of absolute values to int11. */
6584 if ((int01 >= 0 ? int01 : -int01)
6585 < (int11 >= 0 ? int11 : -int11))
6587 tmp = int01, int01 = int11, int11 = tmp;
6588 alt0 = arg00, arg00 = arg10, arg10 = alt0;
6589 alt0 = arg01, arg01 = arg11, arg11 = alt0;
6592 if (exact_log2 (int11) > 0 && int01 % int11 == 0)
6594 alt0 = fold (build2 (MULT_EXPR, type, arg00,
6595 build_int_cst (NULL_TREE,
6603 return fold (build2 (MULT_EXPR, type,
6604 fold (build2 (PLUS_EXPR, type,
6611 /* See if ARG1 is zero and X + ARG1 reduces to X. */
6612 if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
6613 return non_lvalue (fold_convert (type, arg0));
6615 /* Likewise if the operands are reversed. */
6616 if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
6617 return non_lvalue (fold_convert (type, arg1));
6619 /* Convert X + -C into X - C. */
6620 if (TREE_CODE (arg1) == REAL_CST
6621 && REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1)))
6623 tem = fold_negate_const (arg1, type);
6624 if (!TREE_OVERFLOW (arg1) || !flag_trapping_math)
6625 return fold (build2 (MINUS_EXPR, type,
6626 fold_convert (type, arg0),
6627 fold_convert (type, tem)));
6630 /* Convert x+x into x*2.0. */
6631 if (operand_equal_p (arg0, arg1, 0)
6632 && SCALAR_FLOAT_TYPE_P (type))
6633 return fold (build2 (MULT_EXPR, type, arg0,
6634 build_real (type, dconst2)));
6636 /* Convert x*c+x into x*(c+1). */
6637 if (flag_unsafe_math_optimizations
6638 && TREE_CODE (arg0) == MULT_EXPR
6639 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
6640 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0, 1))
6641 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
6645 c = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
6646 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
6647 return fold (build2 (MULT_EXPR, type, arg1,
6648 build_real (type, c)));
6651 /* Convert x+x*c into x*(c+1). */
6652 if (flag_unsafe_math_optimizations
6653 && TREE_CODE (arg1) == MULT_EXPR
6654 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST
6655 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1, 1))
6656 && operand_equal_p (TREE_OPERAND (arg1, 0), arg0, 0))
6660 c = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
6661 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
6662 return fold (build2 (MULT_EXPR, type, arg0,
6663 build_real (type, c)));
6666 /* Convert x*c1+x*c2 into x*(c1+c2). */
6667 if (flag_unsafe_math_optimizations
6668 && TREE_CODE (arg0) == MULT_EXPR
6669 && TREE_CODE (arg1) == MULT_EXPR
6670 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
6671 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0, 1))
6672 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST
6673 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1, 1))
6674 && operand_equal_p (TREE_OPERAND (arg0, 0),
6675 TREE_OPERAND (arg1, 0), 0))
6677 REAL_VALUE_TYPE c1, c2;
6679 c1 = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
6680 c2 = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
6681 real_arithmetic (&c1, PLUS_EXPR, &c1, &c2);
6682 return fold (build2 (MULT_EXPR, type,
6683 TREE_OPERAND (arg0, 0),
6684 build_real (type, c1)));
6686 /* Convert a + (b*c + d*e) into (a + b*c) + d*e */
6687 if (flag_unsafe_math_optimizations
6688 && TREE_CODE (arg1) == PLUS_EXPR
6689 && TREE_CODE (arg0) != MULT_EXPR)
6691 tree tree10 = TREE_OPERAND (arg1, 0);
6692 tree tree11 = TREE_OPERAND (arg1, 1);
6693 if (TREE_CODE (tree11) == MULT_EXPR
6694 && TREE_CODE (tree10) == MULT_EXPR)
6697 tree0 = fold (build2 (PLUS_EXPR, type, arg0, tree10));
6698 return fold (build2 (PLUS_EXPR, type, tree0, tree11));
6701 /* Convert (b*c + d*e) + a into b*c + (d*e +a) */
6702 if (flag_unsafe_math_optimizations
6703 && TREE_CODE (arg0) == PLUS_EXPR
6704 && TREE_CODE (arg1) != MULT_EXPR)
6706 tree tree00 = TREE_OPERAND (arg0, 0);
6707 tree tree01 = TREE_OPERAND (arg0, 1);
6708 if (TREE_CODE (tree01) == MULT_EXPR
6709 && TREE_CODE (tree00) == MULT_EXPR)
6712 tree0 = fold (build2 (PLUS_EXPR, type, tree01, arg1));
6713 return fold (build2 (PLUS_EXPR, type, tree00, tree0));
6719 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
6720 is a rotate of A by C1 bits. */
6721 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
6722 is a rotate of A by B bits. */
6724 enum tree_code code0, code1;
6725 code0 = TREE_CODE (arg0);
6726 code1 = TREE_CODE (arg1);
6727 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
6728 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
6729 && operand_equal_p (TREE_OPERAND (arg0, 0),
6730 TREE_OPERAND (arg1, 0), 0)
6731 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
6733 tree tree01, tree11;
6734 enum tree_code code01, code11;
6736 tree01 = TREE_OPERAND (arg0, 1);
6737 tree11 = TREE_OPERAND (arg1, 1);
6738 STRIP_NOPS (tree01);
6739 STRIP_NOPS (tree11);
6740 code01 = TREE_CODE (tree01);
6741 code11 = TREE_CODE (tree11);
6742 if (code01 == INTEGER_CST
6743 && code11 == INTEGER_CST
6744 && TREE_INT_CST_HIGH (tree01) == 0
6745 && TREE_INT_CST_HIGH (tree11) == 0
6746 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
6747 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
6748 return build2 (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
6749 code0 == LSHIFT_EXPR ? tree01 : tree11);
6750 else if (code11 == MINUS_EXPR)
6752 tree tree110, tree111;
6753 tree110 = TREE_OPERAND (tree11, 0);
6754 tree111 = TREE_OPERAND (tree11, 1);
6755 STRIP_NOPS (tree110);
6756 STRIP_NOPS (tree111);
6757 if (TREE_CODE (tree110) == INTEGER_CST
6758 && 0 == compare_tree_int (tree110,
6760 (TREE_TYPE (TREE_OPERAND
6762 && operand_equal_p (tree01, tree111, 0))
6763 return build2 ((code0 == LSHIFT_EXPR
6766 type, TREE_OPERAND (arg0, 0), tree01);
6768 else if (code01 == MINUS_EXPR)
6770 tree tree010, tree011;
6771 tree010 = TREE_OPERAND (tree01, 0);
6772 tree011 = TREE_OPERAND (tree01, 1);
6773 STRIP_NOPS (tree010);
6774 STRIP_NOPS (tree011);
6775 if (TREE_CODE (tree010) == INTEGER_CST
6776 && 0 == compare_tree_int (tree010,
6778 (TREE_TYPE (TREE_OPERAND
6780 && operand_equal_p (tree11, tree011, 0))
6781 return build2 ((code0 != LSHIFT_EXPR
6784 type, TREE_OPERAND (arg0, 0), tree11);
6790 /* In most languages, can't associate operations on floats through
6791 parentheses. Rather than remember where the parentheses were, we
6792 don't associate floats at all, unless the user has specified
6793 -funsafe-math-optimizations. */
6796 && (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
6798 tree var0, con0, lit0, minus_lit0;
6799 tree var1, con1, lit1, minus_lit1;
6801 /* Split both trees into variables, constants, and literals. Then
6802 associate each group together, the constants with literals,
6803 then the result with variables. This increases the chances of
6804 literals being recombined later and of generating relocatable
6805 expressions for the sum of a constant and literal. */
6806 var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
6807 var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
6808 code == MINUS_EXPR);
6810 /* Only do something if we found more than two objects. Otherwise,
6811 nothing has changed and we risk infinite recursion. */
6812 if (2 < ((var0 != 0) + (var1 != 0)
6813 + (con0 != 0) + (con1 != 0)
6814 + (lit0 != 0) + (lit1 != 0)
6815 + (minus_lit0 != 0) + (minus_lit1 != 0)))
6817 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
6818 if (code == MINUS_EXPR)
6821 var0 = associate_trees (var0, var1, code, type);
6822 con0 = associate_trees (con0, con1, code, type);
6823 lit0 = associate_trees (lit0, lit1, code, type);
6824 minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
6826 /* Preserve the MINUS_EXPR if the negative part of the literal is
6827 greater than the positive part. Otherwise, the multiplicative
6828 folding code (i.e extract_muldiv) may be fooled in case
6829 unsigned constants are subtracted, like in the following
6830 example: ((X*2 + 4) - 8U)/2. */
6831 if (minus_lit0 && lit0)
6833 if (TREE_CODE (lit0) == INTEGER_CST
6834 && TREE_CODE (minus_lit0) == INTEGER_CST
6835 && tree_int_cst_lt (lit0, minus_lit0))
6837 minus_lit0 = associate_trees (minus_lit0, lit0,
6843 lit0 = associate_trees (lit0, minus_lit0,
6851 return fold_convert (type,
6852 associate_trees (var0, minus_lit0,
6856 con0 = associate_trees (con0, minus_lit0,
6858 return fold_convert (type,
6859 associate_trees (var0, con0,
6864 con0 = associate_trees (con0, lit0, code, type);
6865 return fold_convert (type, associate_trees (var0, con0,
6872 t1 = const_binop (code, arg0, arg1, 0);
6873 if (t1 != NULL_TREE)
6875 /* The return value should always have
6876 the same type as the original expression. */
6877 if (TREE_TYPE (t1) != type)
6878 t1 = fold_convert (type, t1);
6885 /* A - (-B) -> A + B */
6886 if (TREE_CODE (arg1) == NEGATE_EXPR)
6887 return fold (build2 (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
6888 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
6889 if (TREE_CODE (arg0) == NEGATE_EXPR
6890 && (FLOAT_TYPE_P (type)
6891 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv))
6892 && negate_expr_p (arg1)
6893 && reorder_operands_p (arg0, arg1))
6894 return fold (build2 (MINUS_EXPR, type, negate_expr (arg1),
6895 TREE_OPERAND (arg0, 0)));
6897 if (! FLOAT_TYPE_P (type))
6899 if (! wins && integer_zerop (arg0))
6900 return negate_expr (fold_convert (type, arg1));
6901 if (integer_zerop (arg1))
6902 return non_lvalue (fold_convert (type, arg0));
6904 /* Fold A - (A & B) into ~B & A. */
6905 if (!TREE_SIDE_EFFECTS (arg0)
6906 && TREE_CODE (arg1) == BIT_AND_EXPR)
6908 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
6909 return fold (build2 (BIT_AND_EXPR, type,
6910 fold (build1 (BIT_NOT_EXPR, type,
6911 TREE_OPERAND (arg1, 0))),
6913 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
6914 return fold (build2 (BIT_AND_EXPR, type,
6915 fold (build1 (BIT_NOT_EXPR, type,
6916 TREE_OPERAND (arg1, 1))),
6920 /* Fold (A & ~B) - (A & B) into (A ^ B) - B, where B is
6921 any power of 2 minus 1. */
6922 if (TREE_CODE (arg0) == BIT_AND_EXPR
6923 && TREE_CODE (arg1) == BIT_AND_EXPR
6924 && operand_equal_p (TREE_OPERAND (arg0, 0),
6925 TREE_OPERAND (arg1, 0), 0))
6927 tree mask0 = TREE_OPERAND (arg0, 1);
6928 tree mask1 = TREE_OPERAND (arg1, 1);
6929 tree tem = fold (build1 (BIT_NOT_EXPR, type, mask0));
6931 if (operand_equal_p (tem, mask1, 0))
6933 tem = fold (build2 (BIT_XOR_EXPR, type,
6934 TREE_OPERAND (arg0, 0), mask1));
6935 return fold (build2 (MINUS_EXPR, type, tem, mask1));
6940 /* See if ARG1 is zero and X - ARG1 reduces to X. */
6941 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
6942 return non_lvalue (fold_convert (type, arg0));
6944 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
6945 ARG0 is zero and X + ARG0 reduces to X, since that would mean
6946 (-ARG1 + ARG0) reduces to -ARG1. */
6947 else if (!wins && fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
6948 return negate_expr (fold_convert (type, arg1));
6950 /* Fold &x - &x. This can happen from &x.foo - &x.
6951 This is unsafe for certain floats even in non-IEEE formats.
6952 In IEEE, it is unsafe because it does wrong for NaNs.
6953 Also note that operand_equal_p is always false if an operand
6956 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
6957 && operand_equal_p (arg0, arg1, 0))
6958 return fold_convert (type, integer_zero_node);
6960 /* A - B -> A + (-B) if B is easily negatable. */
6961 if (!wins && negate_expr_p (arg1)
6962 && ((FLOAT_TYPE_P (type)
6963 /* Avoid this transformation if B is a positive REAL_CST. */
6964 && (TREE_CODE (arg1) != REAL_CST
6965 || REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1))))
6966 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv)))
6967 return fold (build2 (PLUS_EXPR, type, arg0, negate_expr (arg1)));
6969 /* Try folding difference of addresses. */
6973 if (TREE_CODE (arg0) == ADDR_EXPR
6974 && TREE_CODE (arg1) == ADDR_EXPR
6975 && ptr_difference_const (TREE_OPERAND (arg0, 0),
6976 TREE_OPERAND (arg1, 0),
6978 return build_int_cst_type (type, diff);
6981 if (TREE_CODE (arg0) == MULT_EXPR
6982 && TREE_CODE (arg1) == MULT_EXPR
6983 && (INTEGRAL_TYPE_P (type) || flag_unsafe_math_optimizations))
6985 /* (A * C) - (B * C) -> (A-B) * C. */
6986 if (operand_equal_p (TREE_OPERAND (arg0, 1),
6987 TREE_OPERAND (arg1, 1), 0))
6988 return fold (build2 (MULT_EXPR, type,
6989 fold (build2 (MINUS_EXPR, type,
6990 TREE_OPERAND (arg0, 0),
6991 TREE_OPERAND (arg1, 0))),
6992 TREE_OPERAND (arg0, 1)));
6993 /* (A * C1) - (A * C2) -> A * (C1-C2). */
6994 if (operand_equal_p (TREE_OPERAND (arg0, 0),
6995 TREE_OPERAND (arg1, 0), 0))
6996 return fold (build2 (MULT_EXPR, type,
6997 TREE_OPERAND (arg0, 0),
6998 fold (build2 (MINUS_EXPR, type,
6999 TREE_OPERAND (arg0, 1),
7000 TREE_OPERAND (arg1, 1)))));
7006 /* (-A) * (-B) -> A * B */
7007 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
7008 return fold (build2 (MULT_EXPR, type,
7009 TREE_OPERAND (arg0, 0),
7010 negate_expr (arg1)));
7011 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
7012 return fold (build2 (MULT_EXPR, type,
7014 TREE_OPERAND (arg1, 0)));
7016 if (! FLOAT_TYPE_P (type))
7018 if (integer_zerop (arg1))
7019 return omit_one_operand (type, arg1, arg0);
7020 if (integer_onep (arg1))
7021 return non_lvalue (fold_convert (type, arg0));
7023 /* (a * (1 << b)) is (a << b) */
7024 if (TREE_CODE (arg1) == LSHIFT_EXPR
7025 && integer_onep (TREE_OPERAND (arg1, 0)))
7026 return fold (build2 (LSHIFT_EXPR, type, arg0,
7027 TREE_OPERAND (arg1, 1)));
7028 if (TREE_CODE (arg0) == LSHIFT_EXPR
7029 && integer_onep (TREE_OPERAND (arg0, 0)))
7030 return fold (build2 (LSHIFT_EXPR, type, arg1,
7031 TREE_OPERAND (arg0, 1)));
7033 if (TREE_CODE (arg1) == INTEGER_CST
7034 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0),
7035 fold_convert (type, arg1),
7037 return fold_convert (type, tem);
7042 /* Maybe fold x * 0 to 0. The expressions aren't the same
7043 when x is NaN, since x * 0 is also NaN. Nor are they the
7044 same in modes with signed zeros, since multiplying a
7045 negative value by 0 gives -0, not +0. */
7046 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
7047 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
7048 && real_zerop (arg1))
7049 return omit_one_operand (type, arg1, arg0);
7050 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
7051 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
7052 && real_onep (arg1))
7053 return non_lvalue (fold_convert (type, arg0));
7055 /* Transform x * -1.0 into -x. */
7056 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
7057 && real_minus_onep (arg1))
7058 return fold_convert (type, negate_expr (arg0));
7060 /* Convert (C1/X)*C2 into (C1*C2)/X. */
7061 if (flag_unsafe_math_optimizations
7062 && TREE_CODE (arg0) == RDIV_EXPR
7063 && TREE_CODE (arg1) == REAL_CST
7064 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST)
7066 tree tem = const_binop (MULT_EXPR, TREE_OPERAND (arg0, 0),
7069 return fold (build2 (RDIV_EXPR, type, tem,
7070 TREE_OPERAND (arg0, 1)));
7073 if (flag_unsafe_math_optimizations)
7075 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
7076 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
7078 /* Optimizations of root(...)*root(...). */
7079 if (fcode0 == fcode1 && BUILTIN_ROOT_P (fcode0))
7081 tree rootfn, arg, arglist;
7082 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
7083 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
7085 /* Optimize sqrt(x)*sqrt(x) as x. */
7086 if (BUILTIN_SQRT_P (fcode0)
7087 && operand_equal_p (arg00, arg10, 0)
7088 && ! HONOR_SNANS (TYPE_MODE (type)))
7091 /* Optimize root(x)*root(y) as root(x*y). */
7092 rootfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7093 arg = fold (build2 (MULT_EXPR, type, arg00, arg10));
7094 arglist = build_tree_list (NULL_TREE, arg);
7095 return build_function_call_expr (rootfn, arglist);
7098 /* Optimize expN(x)*expN(y) as expN(x+y). */
7099 if (fcode0 == fcode1 && BUILTIN_EXPONENT_P (fcode0))
7101 tree expfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7102 tree arg = build2 (PLUS_EXPR, type,
7103 TREE_VALUE (TREE_OPERAND (arg0, 1)),
7104 TREE_VALUE (TREE_OPERAND (arg1, 1)));
7105 tree arglist = build_tree_list (NULL_TREE, fold (arg));
7106 return build_function_call_expr (expfn, arglist);
7109 /* Optimizations of pow(...)*pow(...). */
7110 if ((fcode0 == BUILT_IN_POW && fcode1 == BUILT_IN_POW)
7111 || (fcode0 == BUILT_IN_POWF && fcode1 == BUILT_IN_POWF)
7112 || (fcode0 == BUILT_IN_POWL && fcode1 == BUILT_IN_POWL))
7114 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
7115 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
7117 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
7118 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
7121 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
7122 if (operand_equal_p (arg01, arg11, 0))
7124 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7125 tree arg = build2 (MULT_EXPR, type, arg00, arg10);
7126 tree arglist = tree_cons (NULL_TREE, fold (arg),
7127 build_tree_list (NULL_TREE,
7129 return build_function_call_expr (powfn, arglist);
7132 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
7133 if (operand_equal_p (arg00, arg10, 0))
7135 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7136 tree arg = fold (build2 (PLUS_EXPR, type, arg01, arg11));
7137 tree arglist = tree_cons (NULL_TREE, arg00,
7138 build_tree_list (NULL_TREE,
7140 return build_function_call_expr (powfn, arglist);
7144 /* Optimize tan(x)*cos(x) as sin(x). */
7145 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_COS)
7146 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_COSF)
7147 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_COSL)
7148 || (fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_TAN)
7149 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_TANF)
7150 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_TANL))
7151 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
7152 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
7154 tree sinfn = mathfn_built_in (type, BUILT_IN_SIN);
7156 if (sinfn != NULL_TREE)
7157 return build_function_call_expr (sinfn,
7158 TREE_OPERAND (arg0, 1));
7161 /* Optimize x*pow(x,c) as pow(x,c+1). */
7162 if (fcode1 == BUILT_IN_POW
7163 || fcode1 == BUILT_IN_POWF
7164 || fcode1 == BUILT_IN_POWL)
7166 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
7167 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
7169 if (TREE_CODE (arg11) == REAL_CST
7170 && ! TREE_CONSTANT_OVERFLOW (arg11)
7171 && operand_equal_p (arg0, arg10, 0))
7173 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
7177 c = TREE_REAL_CST (arg11);
7178 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
7179 arg = build_real (type, c);
7180 arglist = build_tree_list (NULL_TREE, arg);
7181 arglist = tree_cons (NULL_TREE, arg0, arglist);
7182 return build_function_call_expr (powfn, arglist);
7186 /* Optimize pow(x,c)*x as pow(x,c+1). */
7187 if (fcode0 == BUILT_IN_POW
7188 || fcode0 == BUILT_IN_POWF
7189 || fcode0 == BUILT_IN_POWL)
7191 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
7192 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
7194 if (TREE_CODE (arg01) == REAL_CST
7195 && ! TREE_CONSTANT_OVERFLOW (arg01)
7196 && operand_equal_p (arg1, arg00, 0))
7198 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7202 c = TREE_REAL_CST (arg01);
7203 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
7204 arg = build_real (type, c);
7205 arglist = build_tree_list (NULL_TREE, arg);
7206 arglist = tree_cons (NULL_TREE, arg1, arglist);
7207 return build_function_call_expr (powfn, arglist);
7211 /* Optimize x*x as pow(x,2.0), which is expanded as x*x. */
7213 && operand_equal_p (arg0, arg1, 0))
7215 tree powfn = mathfn_built_in (type, BUILT_IN_POW);
7219 tree arg = build_real (type, dconst2);
7220 tree arglist = build_tree_list (NULL_TREE, arg);
7221 arglist = tree_cons (NULL_TREE, arg0, arglist);
7222 return build_function_call_expr (powfn, arglist);
7231 if (integer_all_onesp (arg1))
7232 return omit_one_operand (type, arg1, arg0);
7233 if (integer_zerop (arg1))
7234 return non_lvalue (fold_convert (type, arg0));
7235 if (operand_equal_p (arg0, arg1, 0))
7236 return non_lvalue (fold_convert (type, arg0));
7239 if (TREE_CODE (arg0) == BIT_NOT_EXPR
7240 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
7242 t1 = build_int_cst (type, -1);
7243 t1 = force_fit_type (t1, 0, false, false);
7244 return omit_one_operand (type, t1, arg1);
7248 if (TREE_CODE (arg1) == BIT_NOT_EXPR
7249 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
7251 t1 = build_int_cst (type, -1);
7252 t1 = force_fit_type (t1, 0, false, false);
7253 return omit_one_operand (type, t1, arg0);
7256 t1 = distribute_bit_expr (code, type, arg0, arg1);
7257 if (t1 != NULL_TREE)
7260 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
7262 This results in more efficient code for machines without a NAND
7263 instruction. Combine will canonicalize to the first form
7264 which will allow use of NAND instructions provided by the
7265 backend if they exist. */
7266 if (TREE_CODE (arg0) == BIT_NOT_EXPR
7267 && TREE_CODE (arg1) == BIT_NOT_EXPR)
7269 return fold (build1 (BIT_NOT_EXPR, type,
7270 build2 (BIT_AND_EXPR, type,
7271 TREE_OPERAND (arg0, 0),
7272 TREE_OPERAND (arg1, 0))));
7275 /* See if this can be simplified into a rotate first. If that
7276 is unsuccessful continue in the association code. */
7280 if (integer_zerop (arg1))
7281 return non_lvalue (fold_convert (type, arg0));
7282 if (integer_all_onesp (arg1))
7283 return fold (build1 (BIT_NOT_EXPR, type, arg0));
7284 if (operand_equal_p (arg0, arg1, 0))
7285 return omit_one_operand (type, integer_zero_node, arg0);
7288 if (TREE_CODE (arg0) == BIT_NOT_EXPR
7289 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
7291 t1 = build_int_cst (type, -1);
7292 t1 = force_fit_type (t1, 0, false, false);
7293 return omit_one_operand (type, t1, arg1);
7297 if (TREE_CODE (arg1) == BIT_NOT_EXPR
7298 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
7300 t1 = build_int_cst (type, -1);
7301 t1 = force_fit_type (t1, 0, false, false);
7302 return omit_one_operand (type, t1, arg0);
7305 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
7306 with a constant, and the two constants have no bits in common,
7307 we should treat this as a BIT_IOR_EXPR since this may produce more
7309 if (TREE_CODE (arg0) == BIT_AND_EXPR
7310 && TREE_CODE (arg1) == BIT_AND_EXPR
7311 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7312 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
7313 && integer_zerop (const_binop (BIT_AND_EXPR,
7314 TREE_OPERAND (arg0, 1),
7315 TREE_OPERAND (arg1, 1), 0)))
7317 code = BIT_IOR_EXPR;
7321 /* See if this can be simplified into a rotate first. If that
7322 is unsuccessful continue in the association code. */
7326 if (integer_all_onesp (arg1))
7327 return non_lvalue (fold_convert (type, arg0));
7328 if (integer_zerop (arg1))
7329 return omit_one_operand (type, arg1, arg0);
7330 if (operand_equal_p (arg0, arg1, 0))
7331 return non_lvalue (fold_convert (type, arg0));
7333 /* ~X & X is always zero. */
7334 if (TREE_CODE (arg0) == BIT_NOT_EXPR
7335 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
7336 return omit_one_operand (type, integer_zero_node, arg1);
7338 /* X & ~X is always zero. */
7339 if (TREE_CODE (arg1) == BIT_NOT_EXPR
7340 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
7341 return omit_one_operand (type, integer_zero_node, arg0);
7343 t1 = distribute_bit_expr (code, type, arg0, arg1);
7344 if (t1 != NULL_TREE)
7346 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
7347 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
7348 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
7351 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
7353 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
7354 && (~TREE_INT_CST_LOW (arg1)
7355 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
7356 return fold_convert (type, TREE_OPERAND (arg0, 0));
7359 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
7361 This results in more efficient code for machines without a NOR
7362 instruction. Combine will canonicalize to the first form
7363 which will allow use of NOR instructions provided by the
7364 backend if they exist. */
7365 if (TREE_CODE (arg0) == BIT_NOT_EXPR
7366 && TREE_CODE (arg1) == BIT_NOT_EXPR)
7368 return fold (build1 (BIT_NOT_EXPR, type,
7369 build2 (BIT_IOR_EXPR, type,
7370 TREE_OPERAND (arg0, 0),
7371 TREE_OPERAND (arg1, 0))));
7377 /* Don't touch a floating-point divide by zero unless the mode
7378 of the constant can represent infinity. */
7379 if (TREE_CODE (arg1) == REAL_CST
7380 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
7381 && real_zerop (arg1))
7384 /* (-A) / (-B) -> A / B */
7385 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
7386 return fold (build2 (RDIV_EXPR, type,
7387 TREE_OPERAND (arg0, 0),
7388 negate_expr (arg1)));
7389 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
7390 return fold (build2 (RDIV_EXPR, type,
7392 TREE_OPERAND (arg1, 0)));
7394 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
7395 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
7396 && real_onep (arg1))
7397 return non_lvalue (fold_convert (type, arg0));
7399 /* In IEEE floating point, x/-1 is not equivalent to -x for snans. */
7400 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
7401 && real_minus_onep (arg1))
7402 return non_lvalue (fold_convert (type, negate_expr (arg0)));
7404 /* If ARG1 is a constant, we can convert this to a multiply by the
7405 reciprocal. This does not have the same rounding properties,
7406 so only do this if -funsafe-math-optimizations. We can actually
7407 always safely do it if ARG1 is a power of two, but it's hard to
7408 tell if it is or not in a portable manner. */
7409 if (TREE_CODE (arg1) == REAL_CST)
7411 if (flag_unsafe_math_optimizations
7412 && 0 != (tem = const_binop (code, build_real (type, dconst1),
7414 return fold (build2 (MULT_EXPR, type, arg0, tem));
7415 /* Find the reciprocal if optimizing and the result is exact. */
7419 r = TREE_REAL_CST (arg1);
7420 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
7422 tem = build_real (type, r);
7423 return fold (build2 (MULT_EXPR, type, arg0, tem));
7427 /* Convert A/B/C to A/(B*C). */
7428 if (flag_unsafe_math_optimizations
7429 && TREE_CODE (arg0) == RDIV_EXPR)
7430 return fold (build2 (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
7431 fold (build2 (MULT_EXPR, type,
7432 TREE_OPERAND (arg0, 1), arg1))));
7434 /* Convert A/(B/C) to (A/B)*C. */
7435 if (flag_unsafe_math_optimizations
7436 && TREE_CODE (arg1) == RDIV_EXPR)
7437 return fold (build2 (MULT_EXPR, type,
7438 fold (build2 (RDIV_EXPR, type, arg0,
7439 TREE_OPERAND (arg1, 0))),
7440 TREE_OPERAND (arg1, 1)));
7442 /* Convert C1/(X*C2) into (C1/C2)/X. */
7443 if (flag_unsafe_math_optimizations
7444 && TREE_CODE (arg1) == MULT_EXPR
7445 && TREE_CODE (arg0) == REAL_CST
7446 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
7448 tree tem = const_binop (RDIV_EXPR, arg0,
7449 TREE_OPERAND (arg1, 1), 0);
7451 return fold (build2 (RDIV_EXPR, type, tem,
7452 TREE_OPERAND (arg1, 0)));
7455 if (flag_unsafe_math_optimizations)
7457 enum built_in_function fcode = builtin_mathfn_code (arg1);
7458 /* Optimize x/expN(y) into x*expN(-y). */
7459 if (BUILTIN_EXPONENT_P (fcode))
7461 tree expfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
7462 tree arg = negate_expr (TREE_VALUE (TREE_OPERAND (arg1, 1)));
7463 tree arglist = build_tree_list (NULL_TREE,
7464 fold_convert (type, arg));
7465 arg1 = build_function_call_expr (expfn, arglist);
7466 return fold (build2 (MULT_EXPR, type, arg0, arg1));
7469 /* Optimize x/pow(y,z) into x*pow(y,-z). */
7470 if (fcode == BUILT_IN_POW
7471 || fcode == BUILT_IN_POWF
7472 || fcode == BUILT_IN_POWL)
7474 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
7475 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
7476 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1, 1)));
7477 tree neg11 = fold_convert (type, negate_expr (arg11));
7478 tree arglist = tree_cons(NULL_TREE, arg10,
7479 build_tree_list (NULL_TREE, neg11));
7480 arg1 = build_function_call_expr (powfn, arglist);
7481 return fold (build2 (MULT_EXPR, type, arg0, arg1));
7485 if (flag_unsafe_math_optimizations)
7487 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
7488 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
7490 /* Optimize sin(x)/cos(x) as tan(x). */
7491 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_COS)
7492 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_COSF)
7493 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_COSL))
7494 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
7495 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
7497 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
7499 if (tanfn != NULL_TREE)
7500 return build_function_call_expr (tanfn,
7501 TREE_OPERAND (arg0, 1));
7504 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
7505 if (((fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_SIN)
7506 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_SINF)
7507 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_SINL))
7508 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
7509 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
7511 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
7513 if (tanfn != NULL_TREE)
7515 tree tmp = TREE_OPERAND (arg0, 1);
7516 tmp = build_function_call_expr (tanfn, tmp);
7517 return fold (build2 (RDIV_EXPR, type,
7518 build_real (type, dconst1), tmp));
7522 /* Optimize pow(x,c)/x as pow(x,c-1). */
7523 if (fcode0 == BUILT_IN_POW
7524 || fcode0 == BUILT_IN_POWF
7525 || fcode0 == BUILT_IN_POWL)
7527 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
7528 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0, 1)));
7529 if (TREE_CODE (arg01) == REAL_CST
7530 && ! TREE_CONSTANT_OVERFLOW (arg01)
7531 && operand_equal_p (arg1, arg00, 0))
7533 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7537 c = TREE_REAL_CST (arg01);
7538 real_arithmetic (&c, MINUS_EXPR, &c, &dconst1);
7539 arg = build_real (type, c);
7540 arglist = build_tree_list (NULL_TREE, arg);
7541 arglist = tree_cons (NULL_TREE, arg1, arglist);
7542 return build_function_call_expr (powfn, arglist);
7548 case TRUNC_DIV_EXPR:
7549 case ROUND_DIV_EXPR:
7550 case FLOOR_DIV_EXPR:
7552 case EXACT_DIV_EXPR:
7553 if (integer_onep (arg1))
7554 return non_lvalue (fold_convert (type, arg0));
7555 if (integer_zerop (arg1))
7558 if (!TYPE_UNSIGNED (type)
7559 && TREE_CODE (arg1) == INTEGER_CST
7560 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
7561 && TREE_INT_CST_HIGH (arg1) == -1)
7562 return fold_convert (type, negate_expr (arg0));
7564 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
7565 operation, EXACT_DIV_EXPR.
7567 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
7568 At one time others generated faster code, it's not clear if they do
7569 after the last round to changes to the DIV code in expmed.c. */
7570 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
7571 && multiple_of_p (type, arg0, arg1))
7572 return fold (build2 (EXACT_DIV_EXPR, type, arg0, arg1));
7574 if (TREE_CODE (arg1) == INTEGER_CST
7575 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
7577 return fold_convert (type, tem);
7582 case FLOOR_MOD_EXPR:
7583 case ROUND_MOD_EXPR:
7584 case TRUNC_MOD_EXPR:
7585 if (integer_onep (arg1))
7586 return omit_one_operand (type, integer_zero_node, arg0);
7587 if (integer_zerop (arg1))
7590 /* X % -1 is zero. */
7591 if (!TYPE_UNSIGNED (type)
7592 && TREE_CODE (arg1) == INTEGER_CST
7593 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
7594 && TREE_INT_CST_HIGH (arg1) == -1)
7595 return omit_one_operand (type, integer_zero_node, arg0);
7597 /* Optimize unsigned TRUNC_MOD_EXPR by a power of two into a
7598 BIT_AND_EXPR, i.e. "X % C" into "X & C2". */
7599 if (code == TRUNC_MOD_EXPR
7600 && TYPE_UNSIGNED (type)
7601 && integer_pow2p (arg1))
7603 unsigned HOST_WIDE_INT high, low;
7607 l = tree_log2 (arg1);
7608 if (l >= HOST_BITS_PER_WIDE_INT)
7610 high = ((unsigned HOST_WIDE_INT) 1
7611 << (l - HOST_BITS_PER_WIDE_INT)) - 1;
7617 low = ((unsigned HOST_WIDE_INT) 1 << l) - 1;
7620 mask = build_int_cst_wide (type, low, high);
7621 return fold (build2 (BIT_AND_EXPR, type,
7622 fold_convert (type, arg0), mask));
7625 /* X % -C is the same as X % C. */
7626 if (code == TRUNC_MOD_EXPR
7627 && !TYPE_UNSIGNED (type)
7628 && TREE_CODE (arg1) == INTEGER_CST
7629 && TREE_INT_CST_HIGH (arg1) < 0
7631 /* Avoid this transformation if C is INT_MIN, i.e. C == -C. */
7632 && !sign_bit_p (arg1, arg1))
7633 return fold (build2 (code, type, fold_convert (type, arg0),
7634 fold_convert (type, negate_expr (arg1))));
7636 /* X % -Y is the same as X % Y. */
7637 if (code == TRUNC_MOD_EXPR
7638 && !TYPE_UNSIGNED (type)
7639 && TREE_CODE (arg1) == NEGATE_EXPR
7641 return fold (build2 (code, type, fold_convert (type, arg0),
7642 fold_convert (type, TREE_OPERAND (arg1, 0))));
7644 if (TREE_CODE (arg1) == INTEGER_CST
7645 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
7647 return fold_convert (type, tem);
7653 if (integer_all_onesp (arg0))
7654 return omit_one_operand (type, arg0, arg1);
7658 /* Optimize -1 >> x for arithmetic right shifts. */
7659 if (integer_all_onesp (arg0) && !TYPE_UNSIGNED (type))
7660 return omit_one_operand (type, arg0, arg1);
7661 /* ... fall through ... */
7665 if (integer_zerop (arg1))
7666 return non_lvalue (fold_convert (type, arg0));
7667 if (integer_zerop (arg0))
7668 return omit_one_operand (type, arg0, arg1);
7670 /* Since negative shift count is not well-defined,
7671 don't try to compute it in the compiler. */
7672 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
7674 /* Rewrite an LROTATE_EXPR by a constant into an
7675 RROTATE_EXPR by a new constant. */
7676 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
7678 tree tem = build_int_cst (NULL_TREE,
7679 GET_MODE_BITSIZE (TYPE_MODE (type)));
7680 tem = fold_convert (TREE_TYPE (arg1), tem);
7681 tem = const_binop (MINUS_EXPR, tem, arg1, 0);
7682 return fold (build2 (RROTATE_EXPR, type, arg0, tem));
7685 /* If we have a rotate of a bit operation with the rotate count and
7686 the second operand of the bit operation both constant,
7687 permute the two operations. */
7688 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
7689 && (TREE_CODE (arg0) == BIT_AND_EXPR
7690 || TREE_CODE (arg0) == BIT_IOR_EXPR
7691 || TREE_CODE (arg0) == BIT_XOR_EXPR)
7692 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
7693 return fold (build2 (TREE_CODE (arg0), type,
7694 fold (build2 (code, type,
7695 TREE_OPERAND (arg0, 0), arg1)),
7696 fold (build2 (code, type,
7697 TREE_OPERAND (arg0, 1), arg1))));
7699 /* Two consecutive rotates adding up to the width of the mode can
7701 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
7702 && TREE_CODE (arg0) == RROTATE_EXPR
7703 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7704 && TREE_INT_CST_HIGH (arg1) == 0
7705 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
7706 && ((TREE_INT_CST_LOW (arg1)
7707 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
7708 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type))))
7709 return TREE_OPERAND (arg0, 0);
7714 if (operand_equal_p (arg0, arg1, 0))
7715 return omit_one_operand (type, arg0, arg1);
7716 if (INTEGRAL_TYPE_P (type)
7717 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
7718 return omit_one_operand (type, arg1, arg0);
7722 if (operand_equal_p (arg0, arg1, 0))
7723 return omit_one_operand (type, arg0, arg1);
7724 if (INTEGRAL_TYPE_P (type)
7725 && TYPE_MAX_VALUE (type)
7726 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
7727 return omit_one_operand (type, arg1, arg0);
7730 case TRUTH_NOT_EXPR:
7731 /* The argument to invert_truthvalue must have Boolean type. */
7732 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
7733 arg0 = fold_convert (boolean_type_node, arg0);
7735 /* Note that the operand of this must be an int
7736 and its values must be 0 or 1.
7737 ("true" is a fixed value perhaps depending on the language,
7738 but we don't handle values other than 1 correctly yet.) */
7739 tem = invert_truthvalue (arg0);
7740 /* Avoid infinite recursion. */
7741 if (TREE_CODE (tem) == TRUTH_NOT_EXPR)
7743 tem = fold_single_bit_test (code, arg0, arg1, type);
7748 return fold_convert (type, tem);
7750 case TRUTH_ANDIF_EXPR:
7751 /* Note that the operands of this must be ints
7752 and their values must be 0 or 1.
7753 ("true" is a fixed value perhaps depending on the language.) */
7754 /* If first arg is constant zero, return it. */
7755 if (integer_zerop (arg0))
7756 return fold_convert (type, arg0);
7757 case TRUTH_AND_EXPR:
7758 /* If either arg is constant true, drop it. */
7759 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
7760 return non_lvalue (fold_convert (type, arg1));
7761 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
7762 /* Preserve sequence points. */
7763 && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
7764 return non_lvalue (fold_convert (type, arg0));
7765 /* If second arg is constant zero, result is zero, but first arg
7766 must be evaluated. */
7767 if (integer_zerop (arg1))
7768 return omit_one_operand (type, arg1, arg0);
7769 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
7770 case will be handled here. */
7771 if (integer_zerop (arg0))
7772 return omit_one_operand (type, arg0, arg1);
7774 /* !X && X is always false. */
7775 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
7776 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
7777 return omit_one_operand (type, integer_zero_node, arg1);
7778 /* X && !X is always false. */
7779 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
7780 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
7781 return omit_one_operand (type, integer_zero_node, arg0);
7784 /* We only do these simplifications if we are optimizing. */
7788 /* Check for things like (A || B) && (A || C). We can convert this
7789 to A || (B && C). Note that either operator can be any of the four
7790 truth and/or operations and the transformation will still be
7791 valid. Also note that we only care about order for the
7792 ANDIF and ORIF operators. If B contains side effects, this
7793 might change the truth-value of A. */
7794 if (TREE_CODE (arg0) == TREE_CODE (arg1)
7795 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
7796 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
7797 || TREE_CODE (arg0) == TRUTH_AND_EXPR
7798 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
7799 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
7801 tree a00 = TREE_OPERAND (arg0, 0);
7802 tree a01 = TREE_OPERAND (arg0, 1);
7803 tree a10 = TREE_OPERAND (arg1, 0);
7804 tree a11 = TREE_OPERAND (arg1, 1);
7805 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
7806 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
7807 && (code == TRUTH_AND_EXPR
7808 || code == TRUTH_OR_EXPR));
7810 if (operand_equal_p (a00, a10, 0))
7811 return fold (build2 (TREE_CODE (arg0), type, a00,
7812 fold (build2 (code, type, a01, a11))));
7813 else if (commutative && operand_equal_p (a00, a11, 0))
7814 return fold (build2 (TREE_CODE (arg0), type, a00,
7815 fold (build2 (code, type, a01, a10))));
7816 else if (commutative && operand_equal_p (a01, a10, 0))
7817 return fold (build2 (TREE_CODE (arg0), type, a01,
7818 fold (build2 (code, type, a00, a11))));
7820 /* This case if tricky because we must either have commutative
7821 operators or else A10 must not have side-effects. */
7823 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
7824 && operand_equal_p (a01, a11, 0))
7825 return fold (build2 (TREE_CODE (arg0), type,
7826 fold (build2 (code, type, a00, a10)),
7830 /* See if we can build a range comparison. */
7831 if (0 != (tem = fold_range_test (t)))
7834 /* Check for the possibility of merging component references. If our
7835 lhs is another similar operation, try to merge its rhs with our
7836 rhs. Then try to merge our lhs and rhs. */
7837 if (TREE_CODE (arg0) == code
7838 && 0 != (tem = fold_truthop (code, type,
7839 TREE_OPERAND (arg0, 1), arg1)))
7840 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), tem));
7842 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
7847 case TRUTH_ORIF_EXPR:
7848 /* Note that the operands of this must be ints
7849 and their values must be 0 or true.
7850 ("true" is a fixed value perhaps depending on the language.) */
7851 /* If first arg is constant true, return it. */
7852 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
7853 return fold_convert (type, arg0);
7855 /* If either arg is constant zero, drop it. */
7856 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
7857 return non_lvalue (fold_convert (type, arg1));
7858 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
7859 /* Preserve sequence points. */
7860 && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
7861 return non_lvalue (fold_convert (type, arg0));
7862 /* If second arg is constant true, result is true, but we must
7863 evaluate first arg. */
7864 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
7865 return omit_one_operand (type, arg1, arg0);
7866 /* Likewise for first arg, but note this only occurs here for
7868 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
7869 return omit_one_operand (type, arg0, arg1);
7871 /* !X || X is always true. */
7872 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
7873 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
7874 return omit_one_operand (type, integer_one_node, arg1);
7875 /* X || !X is always true. */
7876 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
7877 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
7878 return omit_one_operand (type, integer_one_node, arg0);
7882 case TRUTH_XOR_EXPR:
7883 /* If the second arg is constant zero, drop it. */
7884 if (integer_zerop (arg1))
7885 return non_lvalue (fold_convert (type, arg0));
7886 /* If the second arg is constant true, this is a logical inversion. */
7887 if (integer_onep (arg1))
7888 return non_lvalue (fold_convert (type, invert_truthvalue (arg0)));
7889 /* Identical arguments cancel to zero. */
7890 if (operand_equal_p (arg0, arg1, 0))
7891 return omit_one_operand (type, integer_zero_node, arg0);
7893 /* !X ^ X is always true. */
7894 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
7895 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
7896 return omit_one_operand (type, integer_one_node, arg1);
7898 /* X ^ !X is always true. */
7899 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
7900 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
7901 return omit_one_operand (type, integer_one_node, arg0);
7911 /* If one arg is a real or integer constant, put it last. */
7912 if (tree_swap_operands_p (arg0, arg1, true))
7913 return fold (build2 (swap_tree_comparison (code), type, arg1, arg0));
7915 /* If this is an equality comparison of the address of a non-weak
7916 object against zero, then we know the result. */
7917 if ((code == EQ_EXPR || code == NE_EXPR)
7918 && TREE_CODE (arg0) == ADDR_EXPR
7919 && DECL_P (TREE_OPERAND (arg0, 0))
7920 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
7921 && integer_zerop (arg1))
7922 return constant_boolean_node (code != EQ_EXPR, type);
7924 /* If this is an equality comparison of the address of two non-weak,
7925 unaliased symbols neither of which are extern (since we do not
7926 have access to attributes for externs), then we know the result. */
7927 if ((code == EQ_EXPR || code == NE_EXPR)
7928 && TREE_CODE (arg0) == ADDR_EXPR
7929 && DECL_P (TREE_OPERAND (arg0, 0))
7930 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
7931 && ! lookup_attribute ("alias",
7932 DECL_ATTRIBUTES (TREE_OPERAND (arg0, 0)))
7933 && ! DECL_EXTERNAL (TREE_OPERAND (arg0, 0))
7934 && TREE_CODE (arg1) == ADDR_EXPR
7935 && DECL_P (TREE_OPERAND (arg1, 0))
7936 && ! DECL_WEAK (TREE_OPERAND (arg1, 0))
7937 && ! lookup_attribute ("alias",
7938 DECL_ATTRIBUTES (TREE_OPERAND (arg1, 0)))
7939 && ! DECL_EXTERNAL (TREE_OPERAND (arg1, 0)))
7940 return constant_boolean_node (operand_equal_p (arg0, arg1, 0)
7941 ? code == EQ_EXPR : code != EQ_EXPR,
7944 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
7946 tree targ0 = strip_float_extensions (arg0);
7947 tree targ1 = strip_float_extensions (arg1);
7948 tree newtype = TREE_TYPE (targ0);
7950 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
7951 newtype = TREE_TYPE (targ1);
7953 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
7954 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
7955 return fold (build2 (code, type, fold_convert (newtype, targ0),
7956 fold_convert (newtype, targ1)));
7958 /* (-a) CMP (-b) -> b CMP a */
7959 if (TREE_CODE (arg0) == NEGATE_EXPR
7960 && TREE_CODE (arg1) == NEGATE_EXPR)
7961 return fold (build2 (code, type, TREE_OPERAND (arg1, 0),
7962 TREE_OPERAND (arg0, 0)));
7964 if (TREE_CODE (arg1) == REAL_CST)
7966 REAL_VALUE_TYPE cst;
7967 cst = TREE_REAL_CST (arg1);
7969 /* (-a) CMP CST -> a swap(CMP) (-CST) */
7970 if (TREE_CODE (arg0) == NEGATE_EXPR)
7972 fold (build2 (swap_tree_comparison (code), type,
7973 TREE_OPERAND (arg0, 0),
7974 build_real (TREE_TYPE (arg1),
7975 REAL_VALUE_NEGATE (cst))));
7977 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
7978 /* a CMP (-0) -> a CMP 0 */
7979 if (REAL_VALUE_MINUS_ZERO (cst))
7980 return fold (build2 (code, type, arg0,
7981 build_real (TREE_TYPE (arg1), dconst0)));
7983 /* x != NaN is always true, other ops are always false. */
7984 if (REAL_VALUE_ISNAN (cst)
7985 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))))
7987 tem = (code == NE_EXPR) ? integer_one_node : integer_zero_node;
7988 return omit_one_operand (type, tem, arg0);
7991 /* Fold comparisons against infinity. */
7992 if (REAL_VALUE_ISINF (cst))
7994 tem = fold_inf_compare (code, type, arg0, arg1);
7995 if (tem != NULL_TREE)
8000 /* If this is a comparison of a real constant with a PLUS_EXPR
8001 or a MINUS_EXPR of a real constant, we can convert it into a
8002 comparison with a revised real constant as long as no overflow
8003 occurs when unsafe_math_optimizations are enabled. */
8004 if (flag_unsafe_math_optimizations
8005 && TREE_CODE (arg1) == REAL_CST
8006 && (TREE_CODE (arg0) == PLUS_EXPR
8007 || TREE_CODE (arg0) == MINUS_EXPR)
8008 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
8009 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
8010 ? MINUS_EXPR : PLUS_EXPR,
8011 arg1, TREE_OPERAND (arg0, 1), 0))
8012 && ! TREE_CONSTANT_OVERFLOW (tem))
8013 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), tem));
8015 /* Likewise, we can simplify a comparison of a real constant with
8016 a MINUS_EXPR whose first operand is also a real constant, i.e.
8017 (c1 - x) < c2 becomes x > c1-c2. */
8018 if (flag_unsafe_math_optimizations
8019 && TREE_CODE (arg1) == REAL_CST
8020 && TREE_CODE (arg0) == MINUS_EXPR
8021 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST
8022 && 0 != (tem = const_binop (MINUS_EXPR, TREE_OPERAND (arg0, 0),
8024 && ! TREE_CONSTANT_OVERFLOW (tem))
8025 return fold (build2 (swap_tree_comparison (code), type,
8026 TREE_OPERAND (arg0, 1), tem));
8028 /* Fold comparisons against built-in math functions. */
8029 if (TREE_CODE (arg1) == REAL_CST
8030 && flag_unsafe_math_optimizations
8031 && ! flag_errno_math)
8033 enum built_in_function fcode = builtin_mathfn_code (arg0);
8035 if (fcode != END_BUILTINS)
8037 tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
8038 if (tem != NULL_TREE)
8044 /* Convert foo++ == CONST into ++foo == CONST + INCR. */
8045 if (TREE_CONSTANT (arg1)
8046 && (TREE_CODE (arg0) == POSTINCREMENT_EXPR
8047 || TREE_CODE (arg0) == POSTDECREMENT_EXPR)
8048 /* This optimization is invalid for ordered comparisons
8049 if CONST+INCR overflows or if foo+incr might overflow.
8050 This optimization is invalid for floating point due to rounding.
8051 For pointer types we assume overflow doesn't happen. */
8052 && (POINTER_TYPE_P (TREE_TYPE (arg0))
8053 || (INTEGRAL_TYPE_P (TREE_TYPE (arg0))
8054 && (code == EQ_EXPR || code == NE_EXPR))))
8056 tree varop, newconst;
8058 if (TREE_CODE (arg0) == POSTINCREMENT_EXPR)
8060 newconst = fold (build2 (PLUS_EXPR, TREE_TYPE (arg0),
8061 arg1, TREE_OPERAND (arg0, 1)));
8062 varop = build2 (PREINCREMENT_EXPR, TREE_TYPE (arg0),
8063 TREE_OPERAND (arg0, 0),
8064 TREE_OPERAND (arg0, 1));
8068 newconst = fold (build2 (MINUS_EXPR, TREE_TYPE (arg0),
8069 arg1, TREE_OPERAND (arg0, 1)));
8070 varop = build2 (PREDECREMENT_EXPR, TREE_TYPE (arg0),
8071 TREE_OPERAND (arg0, 0),
8072 TREE_OPERAND (arg0, 1));
8076 /* If VAROP is a reference to a bitfield, we must mask
8077 the constant by the width of the field. */
8078 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
8079 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (varop, 0), 1))
8080 && host_integerp (DECL_SIZE (TREE_OPERAND
8081 (TREE_OPERAND (varop, 0), 1)), 1))
8083 tree fielddecl = TREE_OPERAND (TREE_OPERAND (varop, 0), 1);
8084 HOST_WIDE_INT size = tree_low_cst (DECL_SIZE (fielddecl), 1);
8085 tree folded_compare, shift;
8087 /* First check whether the comparison would come out
8088 always the same. If we don't do that we would
8089 change the meaning with the masking. */
8090 folded_compare = fold (build2 (code, type,
8091 TREE_OPERAND (varop, 0), arg1));
8092 if (integer_zerop (folded_compare)
8093 || integer_onep (folded_compare))
8094 return omit_one_operand (type, folded_compare, varop);
8096 shift = build_int_cst (NULL_TREE,
8097 TYPE_PRECISION (TREE_TYPE (varop)) - size);
8098 shift = fold_convert (TREE_TYPE (varop), shift);
8099 newconst = fold (build2 (LSHIFT_EXPR, TREE_TYPE (varop),
8101 newconst = fold (build2 (RSHIFT_EXPR, TREE_TYPE (varop),
8105 return fold (build2 (code, type, varop, newconst));
8108 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
8109 This transformation affects the cases which are handled in later
8110 optimizations involving comparisons with non-negative constants. */
8111 if (TREE_CODE (arg1) == INTEGER_CST
8112 && TREE_CODE (arg0) != INTEGER_CST
8113 && tree_int_cst_sgn (arg1) > 0)
8118 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
8119 return fold (build2 (GT_EXPR, type, arg0, arg1));
8122 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
8123 return fold (build2 (LE_EXPR, type, arg0, arg1));
8130 /* Comparisons with the highest or lowest possible integer of
8131 the specified size will have known values.
8133 This is quite similar to fold_relational_hi_lo; however, my
8134 attempts to share the code have been nothing but trouble.
8135 I give up for now. */
8137 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1)));
8139 if (TREE_CODE (arg1) == INTEGER_CST
8140 && ! TREE_CONSTANT_OVERFLOW (arg1)
8141 && width <= HOST_BITS_PER_WIDE_INT
8142 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
8143 || POINTER_TYPE_P (TREE_TYPE (arg1))))
8145 unsigned HOST_WIDE_INT signed_max;
8146 unsigned HOST_WIDE_INT max, min;
8148 signed_max = ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1;
8150 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
8152 max = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
8158 min = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
8161 if (TREE_INT_CST_HIGH (arg1) == 0
8162 && TREE_INT_CST_LOW (arg1) == max)
8166 return omit_one_operand (type, integer_zero_node, arg0);
8169 return fold (build2 (EQ_EXPR, type, arg0, arg1));
8172 return omit_one_operand (type, integer_one_node, arg0);
8175 return fold (build2 (NE_EXPR, type, arg0, arg1));
8177 /* The GE_EXPR and LT_EXPR cases above are not normally
8178 reached because of previous transformations. */
8183 else if (TREE_INT_CST_HIGH (arg1) == 0
8184 && TREE_INT_CST_LOW (arg1) == max - 1)
8188 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
8189 return fold (build2 (EQ_EXPR, type, arg0, arg1));
8191 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
8192 return fold (build2 (NE_EXPR, type, arg0, arg1));
8196 else if (TREE_INT_CST_HIGH (arg1) == (min ? -1 : 0)
8197 && TREE_INT_CST_LOW (arg1) == min)
8201 return omit_one_operand (type, integer_zero_node, arg0);
8204 return fold (build2 (EQ_EXPR, type, arg0, arg1));
8207 return omit_one_operand (type, integer_one_node, arg0);
8210 return fold (build2 (NE_EXPR, type, arg0, arg1));
8215 else if (TREE_INT_CST_HIGH (arg1) == (min ? -1 : 0)
8216 && TREE_INT_CST_LOW (arg1) == min + 1)
8220 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
8221 return fold (build2 (NE_EXPR, type, arg0, arg1));
8223 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
8224 return fold (build2 (EQ_EXPR, type, arg0, arg1));
8229 else if (!in_gimple_form
8230 && TREE_INT_CST_HIGH (arg1) == 0
8231 && TREE_INT_CST_LOW (arg1) == signed_max
8232 && TYPE_UNSIGNED (TREE_TYPE (arg1))
8233 /* signed_type does not work on pointer types. */
8234 && INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
8236 /* The following case also applies to X < signed_max+1
8237 and X >= signed_max+1 because previous transformations. */
8238 if (code == LE_EXPR || code == GT_EXPR)
8241 st0 = lang_hooks.types.signed_type (TREE_TYPE (arg0));
8242 st1 = lang_hooks.types.signed_type (TREE_TYPE (arg1));
8244 (build2 (code == LE_EXPR ? GE_EXPR: LT_EXPR,
8245 type, fold_convert (st0, arg0),
8246 fold_convert (st1, integer_zero_node)));
8252 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
8253 a MINUS_EXPR of a constant, we can convert it into a comparison with
8254 a revised constant as long as no overflow occurs. */
8255 if ((code == EQ_EXPR || code == NE_EXPR)
8256 && TREE_CODE (arg1) == INTEGER_CST
8257 && (TREE_CODE (arg0) == PLUS_EXPR
8258 || TREE_CODE (arg0) == MINUS_EXPR)
8259 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8260 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
8261 ? MINUS_EXPR : PLUS_EXPR,
8262 arg1, TREE_OPERAND (arg0, 1), 0))
8263 && ! TREE_CONSTANT_OVERFLOW (tem))
8264 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), tem));
8266 /* Similarly for a NEGATE_EXPR. */
8267 else if ((code == EQ_EXPR || code == NE_EXPR)
8268 && TREE_CODE (arg0) == NEGATE_EXPR
8269 && TREE_CODE (arg1) == INTEGER_CST
8270 && 0 != (tem = negate_expr (arg1))
8271 && TREE_CODE (tem) == INTEGER_CST
8272 && ! TREE_CONSTANT_OVERFLOW (tem))
8273 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), tem));
8275 /* If we have X - Y == 0, we can convert that to X == Y and similarly
8276 for !=. Don't do this for ordered comparisons due to overflow. */
8277 else if ((code == NE_EXPR || code == EQ_EXPR)
8278 && integer_zerop (arg1) && TREE_CODE (arg0) == MINUS_EXPR)
8279 return fold (build2 (code, type,
8280 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1)));
8282 /* If we are widening one operand of an integer comparison,
8283 see if the other operand is similarly being widened. Perhaps we
8284 can do the comparison in the narrower type. */
8285 else if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
8286 && TREE_CODE (arg0) == NOP_EXPR
8287 && (tem = get_unwidened (arg0, NULL_TREE)) != arg0
8288 && (code == EQ_EXPR || code == NE_EXPR
8289 || TYPE_UNSIGNED (TREE_TYPE (arg0))
8290 == TYPE_UNSIGNED (TREE_TYPE (tem)))
8291 && (t1 = get_unwidened (arg1, TREE_TYPE (tem))) != 0
8292 && (TREE_TYPE (t1) == TREE_TYPE (tem)
8293 || (TREE_CODE (t1) == INTEGER_CST
8294 && int_fits_type_p (t1, TREE_TYPE (tem)))))
8295 return fold (build2 (code, type, tem,
8296 fold_convert (TREE_TYPE (tem), t1)));
8298 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
8299 constant, we can simplify it. */
8300 else if (TREE_CODE (arg1) == INTEGER_CST
8301 && (TREE_CODE (arg0) == MIN_EXPR
8302 || TREE_CODE (arg0) == MAX_EXPR)
8303 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8304 return optimize_minmax_comparison (t);
8306 /* If we are comparing an ABS_EXPR with a constant, we can
8307 convert all the cases into explicit comparisons, but they may
8308 well not be faster than doing the ABS and one comparison.
8309 But ABS (X) <= C is a range comparison, which becomes a subtraction
8310 and a comparison, and is probably faster. */
8311 else if (code == LE_EXPR && TREE_CODE (arg1) == INTEGER_CST
8312 && TREE_CODE (arg0) == ABS_EXPR
8313 && ! TREE_SIDE_EFFECTS (arg0)
8314 && (0 != (tem = negate_expr (arg1)))
8315 && TREE_CODE (tem) == INTEGER_CST
8316 && ! TREE_CONSTANT_OVERFLOW (tem))
8317 return fold (build2 (TRUTH_ANDIF_EXPR, type,
8318 build2 (GE_EXPR, type,
8319 TREE_OPERAND (arg0, 0), tem),
8320 build2 (LE_EXPR, type,
8321 TREE_OPERAND (arg0, 0), arg1)));
8323 /* If this is an EQ or NE comparison with zero and ARG0 is
8324 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
8325 two operations, but the latter can be done in one less insn
8326 on machines that have only two-operand insns or on which a
8327 constant cannot be the first operand. */
8328 if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR)
8329 && TREE_CODE (arg0) == BIT_AND_EXPR)
8331 tree arg00 = TREE_OPERAND (arg0, 0);
8332 tree arg01 = TREE_OPERAND (arg0, 1);
8333 if (TREE_CODE (arg00) == LSHIFT_EXPR
8334 && integer_onep (TREE_OPERAND (arg00, 0)))
8336 fold (build2 (code, type,
8337 build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
8338 build2 (RSHIFT_EXPR, TREE_TYPE (arg00),
8339 arg01, TREE_OPERAND (arg00, 1)),
8340 fold_convert (TREE_TYPE (arg0),
8343 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
8344 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
8346 fold (build2 (code, type,
8347 build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
8348 build2 (RSHIFT_EXPR, TREE_TYPE (arg01),
8349 arg00, TREE_OPERAND (arg01, 1)),
8350 fold_convert (TREE_TYPE (arg0),
8355 /* If this is an NE or EQ comparison of zero against the result of a
8356 signed MOD operation whose second operand is a power of 2, make
8357 the MOD operation unsigned since it is simpler and equivalent. */
8358 if ((code == NE_EXPR || code == EQ_EXPR)
8359 && integer_zerop (arg1)
8360 && !TYPE_UNSIGNED (TREE_TYPE (arg0))
8361 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
8362 || TREE_CODE (arg0) == CEIL_MOD_EXPR
8363 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
8364 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
8365 && integer_pow2p (TREE_OPERAND (arg0, 1)))
8367 tree newtype = lang_hooks.types.unsigned_type (TREE_TYPE (arg0));
8368 tree newmod = fold (build2 (TREE_CODE (arg0), newtype,
8369 fold_convert (newtype,
8370 TREE_OPERAND (arg0, 0)),
8371 fold_convert (newtype,
8372 TREE_OPERAND (arg0, 1))));
8374 return fold (build2 (code, type, newmod,
8375 fold_convert (newtype, arg1)));
8378 /* If this is an NE comparison of zero with an AND of one, remove the
8379 comparison since the AND will give the correct value. */
8380 if (code == NE_EXPR && integer_zerop (arg1)
8381 && TREE_CODE (arg0) == BIT_AND_EXPR
8382 && integer_onep (TREE_OPERAND (arg0, 1)))
8383 return fold_convert (type, arg0);
8385 /* If we have (A & C) == C where C is a power of 2, convert this into
8386 (A & C) != 0. Similarly for NE_EXPR. */
8387 if ((code == EQ_EXPR || code == NE_EXPR)
8388 && TREE_CODE (arg0) == BIT_AND_EXPR
8389 && integer_pow2p (TREE_OPERAND (arg0, 1))
8390 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
8391 return fold (build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
8392 arg0, fold_convert (TREE_TYPE (arg0),
8393 integer_zero_node)));
8395 /* If we have (A & C) != 0 or (A & C) == 0 and C is a power of
8396 2, then fold the expression into shifts and logical operations. */
8397 tem = fold_single_bit_test (code, arg0, arg1, type);
8401 /* If we have (A & C) == D where D & ~C != 0, convert this into 0.
8402 Similarly for NE_EXPR. */
8403 if ((code == EQ_EXPR || code == NE_EXPR)
8404 && TREE_CODE (arg0) == BIT_AND_EXPR
8405 && TREE_CODE (arg1) == INTEGER_CST
8406 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8409 = fold (build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
8410 arg1, build1 (BIT_NOT_EXPR,
8411 TREE_TYPE (TREE_OPERAND (arg0, 1)),
8412 TREE_OPERAND (arg0, 1))));
8413 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
8414 if (integer_nonzerop (dandnotc))
8415 return omit_one_operand (type, rslt, arg0);
8418 /* If we have (A | C) == D where C & ~D != 0, convert this into 0.
8419 Similarly for NE_EXPR. */
8420 if ((code == EQ_EXPR || code == NE_EXPR)
8421 && TREE_CODE (arg0) == BIT_IOR_EXPR
8422 && TREE_CODE (arg1) == INTEGER_CST
8423 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8426 = fold (build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
8427 TREE_OPERAND (arg0, 1),
8428 build1 (BIT_NOT_EXPR, TREE_TYPE (arg1), arg1)));
8429 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
8430 if (integer_nonzerop (candnotd))
8431 return omit_one_operand (type, rslt, arg0);
8434 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
8435 and similarly for >= into !=. */
8436 if ((code == LT_EXPR || code == GE_EXPR)
8437 && TYPE_UNSIGNED (TREE_TYPE (arg0))
8438 && TREE_CODE (arg1) == LSHIFT_EXPR
8439 && integer_onep (TREE_OPERAND (arg1, 0)))
8440 return build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
8441 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
8442 TREE_OPERAND (arg1, 1)),
8443 fold_convert (TREE_TYPE (arg0), integer_zero_node));
8445 else if ((code == LT_EXPR || code == GE_EXPR)
8446 && TYPE_UNSIGNED (TREE_TYPE (arg0))
8447 && (TREE_CODE (arg1) == NOP_EXPR
8448 || TREE_CODE (arg1) == CONVERT_EXPR)
8449 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
8450 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
8452 build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
8453 fold_convert (TREE_TYPE (arg0),
8454 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
8455 TREE_OPERAND (TREE_OPERAND (arg1, 0),
8457 fold_convert (TREE_TYPE (arg0), integer_zero_node));
8459 /* Simplify comparison of something with itself. (For IEEE
8460 floating-point, we can only do some of these simplifications.) */
8461 if (operand_equal_p (arg0, arg1, 0))
8466 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
8467 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8468 return constant_boolean_node (1, type);
8473 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
8474 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8475 return constant_boolean_node (1, type);
8476 return fold (build2 (EQ_EXPR, type, arg0, arg1));
8479 /* For NE, we can only do this simplification if integer
8480 or we don't honor IEEE floating point NaNs. */
8481 if (FLOAT_TYPE_P (TREE_TYPE (arg0))
8482 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8484 /* ... fall through ... */
8487 return constant_boolean_node (0, type);
8493 /* If we are comparing an expression that just has comparisons
8494 of two integer values, arithmetic expressions of those comparisons,
8495 and constants, we can simplify it. There are only three cases
8496 to check: the two values can either be equal, the first can be
8497 greater, or the second can be greater. Fold the expression for
8498 those three values. Since each value must be 0 or 1, we have
8499 eight possibilities, each of which corresponds to the constant 0
8500 or 1 or one of the six possible comparisons.
8502 This handles common cases like (a > b) == 0 but also handles
8503 expressions like ((x > y) - (y > x)) > 0, which supposedly
8504 occur in macroized code. */
8506 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
8508 tree cval1 = 0, cval2 = 0;
8511 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
8512 /* Don't handle degenerate cases here; they should already
8513 have been handled anyway. */
8514 && cval1 != 0 && cval2 != 0
8515 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
8516 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
8517 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
8518 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
8519 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
8520 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
8521 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
8523 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
8524 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
8526 /* We can't just pass T to eval_subst in case cval1 or cval2
8527 was the same as ARG1. */
8530 = fold (build2 (code, type,
8531 eval_subst (arg0, cval1, maxval,
8535 = fold (build2 (code, type,
8536 eval_subst (arg0, cval1, maxval,
8540 = fold (build2 (code, type,
8541 eval_subst (arg0, cval1, minval,
8545 /* All three of these results should be 0 or 1. Confirm they
8546 are. Then use those values to select the proper code
8549 if ((integer_zerop (high_result)
8550 || integer_onep (high_result))
8551 && (integer_zerop (equal_result)
8552 || integer_onep (equal_result))
8553 && (integer_zerop (low_result)
8554 || integer_onep (low_result)))
8556 /* Make a 3-bit mask with the high-order bit being the
8557 value for `>', the next for '=', and the low for '<'. */
8558 switch ((integer_onep (high_result) * 4)
8559 + (integer_onep (equal_result) * 2)
8560 + integer_onep (low_result))
8564 return omit_one_operand (type, integer_zero_node, arg0);
8585 return omit_one_operand (type, integer_one_node, arg0);
8588 tem = build2 (code, type, cval1, cval2);
8590 return save_expr (tem);
8597 /* If this is a comparison of a field, we may be able to simplify it. */
8598 if (((TREE_CODE (arg0) == COMPONENT_REF
8599 && lang_hooks.can_use_bit_fields_p ())
8600 || TREE_CODE (arg0) == BIT_FIELD_REF)
8601 && (code == EQ_EXPR || code == NE_EXPR)
8602 /* Handle the constant case even without -O
8603 to make sure the warnings are given. */
8604 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
8606 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
8611 /* If this is a comparison of complex values and either or both sides
8612 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
8613 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
8614 This may prevent needless evaluations. */
8615 if ((code == EQ_EXPR || code == NE_EXPR)
8616 && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
8617 && (TREE_CODE (arg0) == COMPLEX_EXPR
8618 || TREE_CODE (arg1) == COMPLEX_EXPR
8619 || TREE_CODE (arg0) == COMPLEX_CST
8620 || TREE_CODE (arg1) == COMPLEX_CST))
8622 tree subtype = TREE_TYPE (TREE_TYPE (arg0));
8623 tree real0, imag0, real1, imag1;
8625 arg0 = save_expr (arg0);
8626 arg1 = save_expr (arg1);
8627 real0 = fold (build1 (REALPART_EXPR, subtype, arg0));
8628 imag0 = fold (build1 (IMAGPART_EXPR, subtype, arg0));
8629 real1 = fold (build1 (REALPART_EXPR, subtype, arg1));
8630 imag1 = fold (build1 (IMAGPART_EXPR, subtype, arg1));
8632 return fold (build2 ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR
8635 fold (build2 (code, type, real0, real1)),
8636 fold (build2 (code, type, imag0, imag1))));
8639 /* Optimize comparisons of strlen vs zero to a compare of the
8640 first character of the string vs zero. To wit,
8641 strlen(ptr) == 0 => *ptr == 0
8642 strlen(ptr) != 0 => *ptr != 0
8643 Other cases should reduce to one of these two (or a constant)
8644 due to the return value of strlen being unsigned. */
8645 if ((code == EQ_EXPR || code == NE_EXPR)
8646 && integer_zerop (arg1)
8647 && TREE_CODE (arg0) == CALL_EXPR)
8649 tree fndecl = get_callee_fndecl (arg0);
8653 && DECL_BUILT_IN (fndecl)
8654 && DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_MD
8655 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
8656 && (arglist = TREE_OPERAND (arg0, 1))
8657 && TREE_CODE (TREE_TYPE (TREE_VALUE (arglist))) == POINTER_TYPE
8658 && ! TREE_CHAIN (arglist))
8659 return fold (build2 (code, type,
8660 build1 (INDIRECT_REF, char_type_node,
8661 TREE_VALUE (arglist)),
8662 fold_convert (char_type_node,
8663 integer_zero_node)));
8666 /* We can fold X/C1 op C2 where C1 and C2 are integer constants
8667 into a single range test. */
8668 if (TREE_CODE (arg0) == TRUNC_DIV_EXPR
8669 && TREE_CODE (arg1) == INTEGER_CST
8670 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8671 && !integer_zerop (TREE_OPERAND (arg0, 1))
8672 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
8673 && !TREE_OVERFLOW (arg1))
8675 t1 = fold_div_compare (code, type, arg0, arg1);
8676 if (t1 != NULL_TREE)
8680 if ((code == EQ_EXPR || code == NE_EXPR)
8681 && !TREE_SIDE_EFFECTS (arg0)
8682 && integer_zerop (arg1)
8683 && tree_expr_nonzero_p (arg0))
8684 return constant_boolean_node (code==NE_EXPR, type);
8686 t1 = fold_relational_const (code, type, arg0, arg1);
8687 return t1 == NULL_TREE ? t : t1;
8689 case UNORDERED_EXPR:
8697 if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
8699 t1 = fold_relational_const (code, type, arg0, arg1);
8700 if (t1 != NULL_TREE)
8704 /* If the first operand is NaN, the result is constant. */
8705 if (TREE_CODE (arg0) == REAL_CST
8706 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
8707 && (code != LTGT_EXPR || ! flag_trapping_math))
8709 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
8712 return omit_one_operand (type, t1, arg1);
8715 /* If the second operand is NaN, the result is constant. */
8716 if (TREE_CODE (arg1) == REAL_CST
8717 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg1))
8718 && (code != LTGT_EXPR || ! flag_trapping_math))
8720 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
8723 return omit_one_operand (type, t1, arg0);
8726 /* Simplify unordered comparison of something with itself. */
8727 if ((code == UNLE_EXPR || code == UNGE_EXPR || code == UNEQ_EXPR)
8728 && operand_equal_p (arg0, arg1, 0))
8729 return constant_boolean_node (1, type);
8731 if (code == LTGT_EXPR
8732 && !flag_trapping_math
8733 && operand_equal_p (arg0, arg1, 0))
8734 return constant_boolean_node (0, type);
8736 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
8738 tree targ0 = strip_float_extensions (arg0);
8739 tree targ1 = strip_float_extensions (arg1);
8740 tree newtype = TREE_TYPE (targ0);
8742 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
8743 newtype = TREE_TYPE (targ1);
8745 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
8746 return fold (build2 (code, type, fold_convert (newtype, targ0),
8747 fold_convert (newtype, targ1)));
8753 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
8754 so all simple results must be passed through pedantic_non_lvalue. */
8755 if (TREE_CODE (arg0) == INTEGER_CST)
8757 tem = TREE_OPERAND (t, (integer_zerop (arg0) ? 2 : 1));
8758 /* Only optimize constant conditions when the selected branch
8759 has the same type as the COND_EXPR. This avoids optimizing
8760 away "c ? x : throw", where the throw has a void type. */
8761 if (! VOID_TYPE_P (TREE_TYPE (tem))
8762 || VOID_TYPE_P (type))
8763 return pedantic_non_lvalue (tem);
8766 if (operand_equal_p (arg1, TREE_OPERAND (t, 2), 0))
8767 return pedantic_omit_one_operand (type, arg1, arg0);
8769 /* If we have A op B ? A : C, we may be able to convert this to a
8770 simpler expression, depending on the operation and the values
8771 of B and C. Signed zeros prevent all of these transformations,
8772 for reasons given above each one.
8774 Also try swapping the arguments and inverting the conditional. */
8775 if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
8776 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
8777 arg1, TREE_OPERAND (arg0, 1))
8778 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
8780 tem = fold_cond_expr_with_comparison (type, arg0,
8781 TREE_OPERAND (t, 1),
8782 TREE_OPERAND (t, 2));
8787 if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
8788 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
8789 TREE_OPERAND (t, 2),
8790 TREE_OPERAND (arg0, 1))
8791 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (TREE_OPERAND (t, 2)))))
8793 tem = invert_truthvalue (arg0);
8794 if (TREE_CODE_CLASS (TREE_CODE (tem)) == '<')
8796 tem = fold_cond_expr_with_comparison (type, tem,
8797 TREE_OPERAND (t, 2),
8798 TREE_OPERAND (t, 1));
8804 /* If the second operand is simpler than the third, swap them
8805 since that produces better jump optimization results. */
8806 if (tree_swap_operands_p (TREE_OPERAND (t, 1),
8807 TREE_OPERAND (t, 2), false))
8809 /* See if this can be inverted. If it can't, possibly because
8810 it was a floating-point inequality comparison, don't do
8812 tem = invert_truthvalue (arg0);
8814 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
8815 return fold (build3 (code, type, tem,
8816 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1)));
8819 /* Convert A ? 1 : 0 to simply A. */
8820 if (integer_onep (TREE_OPERAND (t, 1))
8821 && integer_zerop (TREE_OPERAND (t, 2))
8822 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
8823 call to fold will try to move the conversion inside
8824 a COND, which will recurse. In that case, the COND_EXPR
8825 is probably the best choice, so leave it alone. */
8826 && type == TREE_TYPE (arg0))
8827 return pedantic_non_lvalue (arg0);
8829 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
8830 over COND_EXPR in cases such as floating point comparisons. */
8831 if (integer_zerop (TREE_OPERAND (t, 1))
8832 && integer_onep (TREE_OPERAND (t, 2))
8833 && truth_value_p (TREE_CODE (arg0)))
8834 return pedantic_non_lvalue (fold_convert (type,
8835 invert_truthvalue (arg0)));
8837 /* A < 0 ? <sign bit of A> : 0 is simply (A & <sign bit of A>). */
8838 if (TREE_CODE (arg0) == LT_EXPR
8839 && integer_zerop (TREE_OPERAND (arg0, 1))
8840 && integer_zerop (TREE_OPERAND (t, 2))
8841 && (tem = sign_bit_p (TREE_OPERAND (arg0, 0), arg1)))
8842 return fold_convert (type, fold (build2 (BIT_AND_EXPR,
8843 TREE_TYPE (tem), tem, arg1)));
8845 /* (A >> N) & 1 ? (1 << N) : 0 is simply A & (1 << N). A & 1 was
8846 already handled above. */
8847 if (TREE_CODE (arg0) == BIT_AND_EXPR
8848 && integer_onep (TREE_OPERAND (arg0, 1))
8849 && integer_zerop (TREE_OPERAND (t, 2))
8850 && integer_pow2p (arg1))
8852 tree tem = TREE_OPERAND (arg0, 0);
8854 if (TREE_CODE (tem) == RSHIFT_EXPR
8855 && TREE_CODE (TREE_OPERAND (tem, 1)) == INTEGER_CST
8856 && (unsigned HOST_WIDE_INT) tree_log2 (arg1) ==
8857 TREE_INT_CST_LOW (TREE_OPERAND (tem, 1)))
8858 return fold (build2 (BIT_AND_EXPR, type,
8859 TREE_OPERAND (tem, 0), arg1));
8862 /* A & N ? N : 0 is simply A & N if N is a power of two. This
8863 is probably obsolete because the first operand should be a
8864 truth value (that's why we have the two cases above), but let's
8865 leave it in until we can confirm this for all front-ends. */
8866 if (integer_zerop (TREE_OPERAND (t, 2))
8867 && TREE_CODE (arg0) == NE_EXPR
8868 && integer_zerop (TREE_OPERAND (arg0, 1))
8869 && integer_pow2p (arg1)
8870 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
8871 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
8872 arg1, OEP_ONLY_CONST))
8873 return pedantic_non_lvalue (fold_convert (type,
8874 TREE_OPERAND (arg0, 0)));
8876 /* Convert A ? B : 0 into A && B if A and B are truth values. */
8877 if (integer_zerop (TREE_OPERAND (t, 2))
8878 && truth_value_p (TREE_CODE (arg0))
8879 && truth_value_p (TREE_CODE (arg1)))
8880 return fold (build2 (TRUTH_ANDIF_EXPR, type, arg0, arg1));
8882 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
8883 if (integer_onep (TREE_OPERAND (t, 2))
8884 && truth_value_p (TREE_CODE (arg0))
8885 && truth_value_p (TREE_CODE (arg1)))
8887 /* Only perform transformation if ARG0 is easily inverted. */
8888 tem = invert_truthvalue (arg0);
8889 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
8890 return fold (build2 (TRUTH_ORIF_EXPR, type, tem, arg1));
8893 /* Convert A ? 0 : B into !A && B if A and B are truth values. */
8894 if (integer_zerop (arg1)
8895 && truth_value_p (TREE_CODE (arg0))
8896 && truth_value_p (TREE_CODE (TREE_OPERAND (t, 2))))
8898 /* Only perform transformation if ARG0 is easily inverted. */
8899 tem = invert_truthvalue (arg0);
8900 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
8901 return fold (build2 (TRUTH_ANDIF_EXPR, type, tem,
8902 TREE_OPERAND (t, 2)));
8905 /* Convert A ? 1 : B into A || B if A and B are truth values. */
8906 if (integer_onep (arg1)
8907 && truth_value_p (TREE_CODE (arg0))
8908 && truth_value_p (TREE_CODE (TREE_OPERAND (t, 2))))
8909 return fold (build2 (TRUTH_ORIF_EXPR, type, arg0,
8910 TREE_OPERAND (t, 2)));
8915 /* When pedantic, a compound expression can be neither an lvalue
8916 nor an integer constant expression. */
8917 if (TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
8919 /* Don't let (0, 0) be null pointer constant. */
8920 tem = integer_zerop (arg1) ? build1 (NOP_EXPR, type, arg1)
8921 : fold_convert (type, arg1);
8922 return pedantic_non_lvalue (tem);
8926 return build_complex (type, arg0, arg1);
8930 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8932 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
8933 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
8934 TREE_OPERAND (arg0, 1));
8935 else if (TREE_CODE (arg0) == COMPLEX_CST)
8936 return TREE_REALPART (arg0);
8937 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8938 return fold (build2 (TREE_CODE (arg0), type,
8939 fold (build1 (REALPART_EXPR, type,
8940 TREE_OPERAND (arg0, 0))),
8941 fold (build1 (REALPART_EXPR, type,
8942 TREE_OPERAND (arg0, 1)))));
8946 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8947 return fold_convert (type, integer_zero_node);
8948 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
8949 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
8950 TREE_OPERAND (arg0, 0));
8951 else if (TREE_CODE (arg0) == COMPLEX_CST)
8952 return TREE_IMAGPART (arg0);
8953 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8954 return fold (build2 (TREE_CODE (arg0), type,
8955 fold (build1 (IMAGPART_EXPR, type,
8956 TREE_OPERAND (arg0, 0))),
8957 fold (build1 (IMAGPART_EXPR, type,
8958 TREE_OPERAND (arg0, 1)))));
8962 /* Check for a built-in function. */
8963 if (TREE_CODE (TREE_OPERAND (t, 0)) == ADDR_EXPR
8964 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0))
8966 && DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (t, 0), 0)))
8968 tree tmp = fold_builtin (t, false);
8976 } /* switch (code) */
8979 #ifdef ENABLE_FOLD_CHECKING
8982 static void fold_checksum_tree (tree, struct md5_ctx *, htab_t);
8983 static void fold_check_failed (tree, tree);
8984 void print_fold_checksum (tree);
8986 /* When --enable-checking=fold, compute a digest of expr before
8987 and after actual fold call to see if fold did not accidentally
8988 change original expr. */
8995 unsigned char checksum_before[16], checksum_after[16];
8998 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
8999 md5_init_ctx (&ctx);
9000 fold_checksum_tree (expr, &ctx, ht);
9001 md5_finish_ctx (&ctx, checksum_before);
9004 ret = fold_1 (expr);
9006 md5_init_ctx (&ctx);
9007 fold_checksum_tree (expr, &ctx, ht);
9008 md5_finish_ctx (&ctx, checksum_after);
9011 if (memcmp (checksum_before, checksum_after, 16))
9012 fold_check_failed (expr, ret);
9018 print_fold_checksum (tree expr)
9021 unsigned char checksum[16], cnt;
9024 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
9025 md5_init_ctx (&ctx);
9026 fold_checksum_tree (expr, &ctx, ht);
9027 md5_finish_ctx (&ctx, checksum);
9029 for (cnt = 0; cnt < 16; ++cnt)
9030 fprintf (stderr, "%02x", checksum[cnt]);
9031 putc ('\n', stderr);
9035 fold_check_failed (tree expr ATTRIBUTE_UNUSED, tree ret ATTRIBUTE_UNUSED)
9037 internal_error ("fold check: original tree changed by fold");
9041 fold_checksum_tree (tree expr, struct md5_ctx *ctx, htab_t ht)
9044 enum tree_code code;
9045 char buf[sizeof (struct tree_decl)];
9048 gcc_assert ((sizeof (struct tree_exp) + 5 * sizeof (tree)
9049 <= sizeof (struct tree_decl))
9050 && sizeof (struct tree_type) <= sizeof (struct tree_decl));
9053 slot = htab_find_slot (ht, expr, INSERT);
9057 code = TREE_CODE (expr);
9058 if (TREE_CODE_CLASS (code) == 'd' && DECL_ASSEMBLER_NAME_SET_P (expr))
9060 /* Allow DECL_ASSEMBLER_NAME to be modified. */
9061 memcpy (buf, expr, tree_size (expr));
9063 SET_DECL_ASSEMBLER_NAME (expr, NULL);
9065 else if (TREE_CODE_CLASS (code) == 't'
9066 && (TYPE_POINTER_TO (expr) || TYPE_REFERENCE_TO (expr)
9067 || TYPE_CACHED_VALUES_P (expr)))
9069 /* Allow these fields to be modified. */
9070 memcpy (buf, expr, tree_size (expr));
9072 TYPE_POINTER_TO (expr) = NULL;
9073 TYPE_REFERENCE_TO (expr) = NULL;
9074 TYPE_CACHED_VALUES_P (expr) = 0;
9075 TYPE_CACHED_VALUES (expr) = NULL;
9077 md5_process_bytes (expr, tree_size (expr), ctx);
9078 fold_checksum_tree (TREE_TYPE (expr), ctx, ht);
9079 if (TREE_CODE_CLASS (code) != 't' && TREE_CODE_CLASS (code) != 'd')
9080 fold_checksum_tree (TREE_CHAIN (expr), ctx, ht);
9081 switch (TREE_CODE_CLASS (code))
9087 md5_process_bytes (TREE_STRING_POINTER (expr),
9088 TREE_STRING_LENGTH (expr), ctx);
9091 fold_checksum_tree (TREE_REALPART (expr), ctx, ht);
9092 fold_checksum_tree (TREE_IMAGPART (expr), ctx, ht);
9095 fold_checksum_tree (TREE_VECTOR_CST_ELTS (expr), ctx, ht);
9105 fold_checksum_tree (TREE_PURPOSE (expr), ctx, ht);
9106 fold_checksum_tree (TREE_VALUE (expr), ctx, ht);
9109 for (i = 0; i < TREE_VEC_LENGTH (expr); ++i)
9110 fold_checksum_tree (TREE_VEC_ELT (expr, i), ctx, ht);
9122 len = first_rtl_op (code);
9123 for (i = 0; i < len; ++i)
9124 fold_checksum_tree (TREE_OPERAND (expr, i), ctx, ht);
9127 fold_checksum_tree (DECL_SIZE (expr), ctx, ht);
9128 fold_checksum_tree (DECL_SIZE_UNIT (expr), ctx, ht);
9129 fold_checksum_tree (DECL_NAME (expr), ctx, ht);
9130 fold_checksum_tree (DECL_CONTEXT (expr), ctx, ht);
9131 fold_checksum_tree (DECL_ARGUMENTS (expr), ctx, ht);
9132 fold_checksum_tree (DECL_RESULT_FLD (expr), ctx, ht);
9133 fold_checksum_tree (DECL_INITIAL (expr), ctx, ht);
9134 fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr), ctx, ht);
9135 fold_checksum_tree (DECL_SECTION_NAME (expr), ctx, ht);
9136 fold_checksum_tree (DECL_ATTRIBUTES (expr), ctx, ht);
9137 fold_checksum_tree (DECL_VINDEX (expr), ctx, ht);
9140 if (TREE_CODE (expr) == ENUMERAL_TYPE)
9141 fold_checksum_tree (TYPE_VALUES (expr), ctx, ht);
9142 fold_checksum_tree (TYPE_SIZE (expr), ctx, ht);
9143 fold_checksum_tree (TYPE_SIZE_UNIT (expr), ctx, ht);
9144 fold_checksum_tree (TYPE_ATTRIBUTES (expr), ctx, ht);
9145 fold_checksum_tree (TYPE_NAME (expr), ctx, ht);
9146 if (INTEGRAL_TYPE_P (expr)
9147 || SCALAR_FLOAT_TYPE_P (expr))
9149 fold_checksum_tree (TYPE_MIN_VALUE (expr), ctx, ht);
9150 fold_checksum_tree (TYPE_MAX_VALUE (expr), ctx, ht);
9152 fold_checksum_tree (TYPE_MAIN_VARIANT (expr), ctx, ht);
9153 if (TREE_CODE (expr) == RECORD_TYPE
9154 || TREE_CODE (expr) == UNION_TYPE
9155 || TREE_CODE (expr) == QUAL_UNION_TYPE)
9156 fold_checksum_tree (TYPE_BINFO (expr), ctx, ht);
9157 fold_checksum_tree (TYPE_CONTEXT (expr), ctx, ht);
9166 /* Perform constant folding and related simplification of initializer
9167 expression EXPR. This behaves identically to "fold" but ignores
9168 potential run-time traps and exceptions that fold must preserve. */
9171 fold_initializer (tree expr)
9173 int saved_signaling_nans = flag_signaling_nans;
9174 int saved_trapping_math = flag_trapping_math;
9175 int saved_trapv = flag_trapv;
9178 flag_signaling_nans = 0;
9179 flag_trapping_math = 0;
9182 result = fold (expr);
9184 flag_signaling_nans = saved_signaling_nans;
9185 flag_trapping_math = saved_trapping_math;
9186 flag_trapv = saved_trapv;
9191 /* Determine if first argument is a multiple of second argument. Return 0 if
9192 it is not, or we cannot easily determined it to be.
9194 An example of the sort of thing we care about (at this point; this routine
9195 could surely be made more general, and expanded to do what the *_DIV_EXPR's
9196 fold cases do now) is discovering that
9198 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
9204 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
9206 This code also handles discovering that
9208 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
9210 is a multiple of 8 so we don't have to worry about dealing with a
9213 Note that we *look* inside a SAVE_EXPR only to determine how it was
9214 calculated; it is not safe for fold to do much of anything else with the
9215 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
9216 at run time. For example, the latter example above *cannot* be implemented
9217 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
9218 evaluation time of the original SAVE_EXPR is not necessarily the same at
9219 the time the new expression is evaluated. The only optimization of this
9220 sort that would be valid is changing
9222 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
9226 SAVE_EXPR (I) * SAVE_EXPR (J)
9228 (where the same SAVE_EXPR (J) is used in the original and the
9229 transformed version). */
9232 multiple_of_p (tree type, tree top, tree bottom)
9234 if (operand_equal_p (top, bottom, 0))
9237 if (TREE_CODE (type) != INTEGER_TYPE)
9240 switch (TREE_CODE (top))
9243 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
9244 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
9248 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
9249 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
9252 if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
9256 op1 = TREE_OPERAND (top, 1);
9257 /* const_binop may not detect overflow correctly,
9258 so check for it explicitly here. */
9259 if (TYPE_PRECISION (TREE_TYPE (size_one_node))
9260 > TREE_INT_CST_LOW (op1)
9261 && TREE_INT_CST_HIGH (op1) == 0
9262 && 0 != (t1 = fold_convert (type,
9263 const_binop (LSHIFT_EXPR,
9266 && ! TREE_OVERFLOW (t1))
9267 return multiple_of_p (type, t1, bottom);
9272 /* Can't handle conversions from non-integral or wider integral type. */
9273 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
9274 || (TYPE_PRECISION (type)
9275 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
9278 /* .. fall through ... */
9281 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
9284 if (TREE_CODE (bottom) != INTEGER_CST
9285 || (TYPE_UNSIGNED (type)
9286 && (tree_int_cst_sgn (top) < 0
9287 || tree_int_cst_sgn (bottom) < 0)))
9289 return integer_zerop (const_binop (TRUNC_MOD_EXPR,
9297 /* Return true if `t' is known to be non-negative. */
9300 tree_expr_nonnegative_p (tree t)
9302 switch (TREE_CODE (t))
9308 return tree_int_cst_sgn (t) >= 0;
9311 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
9314 if (FLOAT_TYPE_P (TREE_TYPE (t)))
9315 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9316 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9318 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
9319 both unsigned and at least 2 bits shorter than the result. */
9320 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
9321 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
9322 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
9324 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
9325 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
9326 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
9327 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
9329 unsigned int prec = MAX (TYPE_PRECISION (inner1),
9330 TYPE_PRECISION (inner2)) + 1;
9331 return prec < TYPE_PRECISION (TREE_TYPE (t));
9337 if (FLOAT_TYPE_P (TREE_TYPE (t)))
9339 /* x * x for floating point x is always non-negative. */
9340 if (operand_equal_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1), 0))
9342 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9343 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9346 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
9347 both unsigned and their total bits is shorter than the result. */
9348 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
9349 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
9350 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
9352 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
9353 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
9354 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
9355 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
9356 return TYPE_PRECISION (inner1) + TYPE_PRECISION (inner2)
9357 < TYPE_PRECISION (TREE_TYPE (t));
9361 case TRUNC_DIV_EXPR:
9363 case FLOOR_DIV_EXPR:
9364 case ROUND_DIV_EXPR:
9365 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9366 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9368 case TRUNC_MOD_EXPR:
9370 case FLOOR_MOD_EXPR:
9371 case ROUND_MOD_EXPR:
9372 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9375 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9376 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9379 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
9380 || tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9383 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9384 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9388 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
9389 tree outer_type = TREE_TYPE (t);
9391 if (TREE_CODE (outer_type) == REAL_TYPE)
9393 if (TREE_CODE (inner_type) == REAL_TYPE)
9394 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9395 if (TREE_CODE (inner_type) == INTEGER_TYPE)
9397 if (TYPE_UNSIGNED (inner_type))
9399 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9402 else if (TREE_CODE (outer_type) == INTEGER_TYPE)
9404 if (TREE_CODE (inner_type) == REAL_TYPE)
9405 return tree_expr_nonnegative_p (TREE_OPERAND (t,0));
9406 if (TREE_CODE (inner_type) == INTEGER_TYPE)
9407 return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
9408 && TYPE_UNSIGNED (inner_type);
9414 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
9415 && tree_expr_nonnegative_p (TREE_OPERAND (t, 2));
9417 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9419 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9420 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9422 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9423 || tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9425 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9427 return tree_expr_nonnegative_p (expr_last (TREE_OPERAND (t, 1)));
9429 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9430 case NON_LVALUE_EXPR:
9431 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9433 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9437 tree temp = TARGET_EXPR_SLOT (t);
9438 t = TARGET_EXPR_INITIAL (t);
9440 /* If the initializer is non-void, then it's a normal expression
9441 that will be assigned to the slot. */
9442 if (!VOID_TYPE_P (t))
9443 return tree_expr_nonnegative_p (t);
9445 /* Otherwise, the initializer sets the slot in some way. One common
9446 way is an assignment statement at the end of the initializer. */
9449 if (TREE_CODE (t) == BIND_EXPR)
9450 t = expr_last (BIND_EXPR_BODY (t));
9451 else if (TREE_CODE (t) == TRY_FINALLY_EXPR
9452 || TREE_CODE (t) == TRY_CATCH_EXPR)
9453 t = expr_last (TREE_OPERAND (t, 0));
9454 else if (TREE_CODE (t) == STATEMENT_LIST)
9459 if (TREE_CODE (t) == MODIFY_EXPR
9460 && TREE_OPERAND (t, 0) == temp)
9461 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9468 tree fndecl = get_callee_fndecl (t);
9469 tree arglist = TREE_OPERAND (t, 1);
9471 && DECL_BUILT_IN (fndecl)
9472 && DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_MD)
9473 switch (DECL_FUNCTION_CODE (fndecl))
9475 #define CASE_BUILTIN_F(BUILT_IN_FN) \
9476 case BUILT_IN_FN: case BUILT_IN_FN##F: case BUILT_IN_FN##L:
9477 #define CASE_BUILTIN_I(BUILT_IN_FN) \
9478 case BUILT_IN_FN: case BUILT_IN_FN##L: case BUILT_IN_FN##LL:
9480 CASE_BUILTIN_F (BUILT_IN_ACOS)
9481 CASE_BUILTIN_F (BUILT_IN_ACOSH)
9482 CASE_BUILTIN_F (BUILT_IN_CABS)
9483 CASE_BUILTIN_F (BUILT_IN_COSH)
9484 CASE_BUILTIN_F (BUILT_IN_ERFC)
9485 CASE_BUILTIN_F (BUILT_IN_EXP)
9486 CASE_BUILTIN_F (BUILT_IN_EXP10)
9487 CASE_BUILTIN_F (BUILT_IN_EXP2)
9488 CASE_BUILTIN_F (BUILT_IN_FABS)
9489 CASE_BUILTIN_F (BUILT_IN_FDIM)
9490 CASE_BUILTIN_F (BUILT_IN_FREXP)
9491 CASE_BUILTIN_F (BUILT_IN_HYPOT)
9492 CASE_BUILTIN_F (BUILT_IN_POW10)
9493 CASE_BUILTIN_I (BUILT_IN_FFS)
9494 CASE_BUILTIN_I (BUILT_IN_PARITY)
9495 CASE_BUILTIN_I (BUILT_IN_POPCOUNT)
9499 CASE_BUILTIN_F (BUILT_IN_SQRT)
9500 /* sqrt(-0.0) is -0.0. */
9501 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (t))))
9503 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
9505 CASE_BUILTIN_F (BUILT_IN_ASINH)
9506 CASE_BUILTIN_F (BUILT_IN_ATAN)
9507 CASE_BUILTIN_F (BUILT_IN_ATANH)
9508 CASE_BUILTIN_F (BUILT_IN_CBRT)
9509 CASE_BUILTIN_F (BUILT_IN_CEIL)
9510 CASE_BUILTIN_F (BUILT_IN_ERF)
9511 CASE_BUILTIN_F (BUILT_IN_EXPM1)
9512 CASE_BUILTIN_F (BUILT_IN_FLOOR)
9513 CASE_BUILTIN_F (BUILT_IN_FMOD)
9514 CASE_BUILTIN_F (BUILT_IN_LDEXP)
9515 CASE_BUILTIN_F (BUILT_IN_LLRINT)
9516 CASE_BUILTIN_F (BUILT_IN_LLROUND)
9517 CASE_BUILTIN_F (BUILT_IN_LRINT)
9518 CASE_BUILTIN_F (BUILT_IN_LROUND)
9519 CASE_BUILTIN_F (BUILT_IN_MODF)
9520 CASE_BUILTIN_F (BUILT_IN_NEARBYINT)
9521 CASE_BUILTIN_F (BUILT_IN_POW)
9522 CASE_BUILTIN_F (BUILT_IN_RINT)
9523 CASE_BUILTIN_F (BUILT_IN_ROUND)
9524 CASE_BUILTIN_F (BUILT_IN_SIGNBIT)
9525 CASE_BUILTIN_F (BUILT_IN_SINH)
9526 CASE_BUILTIN_F (BUILT_IN_TANH)
9527 CASE_BUILTIN_F (BUILT_IN_TRUNC)
9528 /* True if the 1st argument is nonnegative. */
9529 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
9531 CASE_BUILTIN_F (BUILT_IN_FMAX)
9532 /* True if the 1st OR 2nd arguments are nonnegative. */
9533 return tree_expr_nonnegative_p (TREE_VALUE (arglist))
9534 || tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist)));
9536 CASE_BUILTIN_F (BUILT_IN_FMIN)
9537 /* True if the 1st AND 2nd arguments are nonnegative. */
9538 return tree_expr_nonnegative_p (TREE_VALUE (arglist))
9539 && tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist)));
9541 CASE_BUILTIN_F (BUILT_IN_COPYSIGN)
9542 /* True if the 2nd argument is nonnegative. */
9543 return tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist)));
9547 #undef CASE_BUILTIN_F
9548 #undef CASE_BUILTIN_I
9552 /* ... fall through ... */
9555 if (truth_value_p (TREE_CODE (t)))
9556 /* Truth values evaluate to 0 or 1, which is nonnegative. */
9560 /* We don't know sign of `t', so be conservative and return false. */
9564 /* Return true when T is an address and is known to be nonzero.
9565 For floating point we further ensure that T is not denormal.
9566 Similar logic is present in nonzero_address in rtlanal.h */
9569 tree_expr_nonzero_p (tree t)
9571 tree type = TREE_TYPE (t);
9573 /* Doing something useful for floating point would need more work. */
9574 if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
9577 switch (TREE_CODE (t))
9580 if (!TYPE_UNSIGNED (type) && !flag_wrapv)
9581 return tree_expr_nonzero_p (TREE_OPERAND (t, 0));
9584 /* We used to test for !integer_zerop here. This does not work correctly
9585 if TREE_CONSTANT_OVERFLOW (t). */
9586 return (TREE_INT_CST_LOW (t) != 0
9587 || TREE_INT_CST_HIGH (t) != 0);
9590 if (!TYPE_UNSIGNED (type) && !flag_wrapv)
9592 /* With the presence of negative values it is hard
9593 to say something. */
9594 if (!tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9595 || !tree_expr_nonnegative_p (TREE_OPERAND (t, 1)))
9597 /* One of operands must be positive and the other non-negative. */
9598 return (tree_expr_nonzero_p (TREE_OPERAND (t, 0))
9599 || tree_expr_nonzero_p (TREE_OPERAND (t, 1)));
9604 if (!TYPE_UNSIGNED (type) && !flag_wrapv)
9606 return (tree_expr_nonzero_p (TREE_OPERAND (t, 0))
9607 && tree_expr_nonzero_p (TREE_OPERAND (t, 1)));
9613 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
9614 tree outer_type = TREE_TYPE (t);
9616 return (TYPE_PRECISION (inner_type) >= TYPE_PRECISION (outer_type)
9617 && tree_expr_nonzero_p (TREE_OPERAND (t, 0)));
9623 tree base = get_base_address (TREE_OPERAND (t, 0));
9628 /* Weak declarations may link to NULL. */
9630 return !DECL_WEAK (base);
9632 /* Constants are never weak. */
9633 if (TREE_CODE_CLASS (TREE_CODE (base)) == 'c')
9640 return (tree_expr_nonzero_p (TREE_OPERAND (t, 1))
9641 && tree_expr_nonzero_p (TREE_OPERAND (t, 2)));
9644 return (tree_expr_nonzero_p (TREE_OPERAND (t, 0))
9645 && tree_expr_nonzero_p (TREE_OPERAND (t, 1)));
9648 if (tree_expr_nonzero_p (TREE_OPERAND (t, 0)))
9650 /* When both operands are nonzero, then MAX must be too. */
9651 if (tree_expr_nonzero_p (TREE_OPERAND (t, 1)))
9654 /* MAX where operand 0 is positive is positive. */
9655 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9657 /* MAX where operand 1 is positive is positive. */
9658 else if (tree_expr_nonzero_p (TREE_OPERAND (t, 1))
9659 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1)))
9666 return tree_expr_nonzero_p (TREE_OPERAND (t, 1));
9669 case NON_LVALUE_EXPR:
9670 return tree_expr_nonzero_p (TREE_OPERAND (t, 0));
9673 return tree_expr_nonzero_p (TREE_OPERAND (t, 1))
9674 || tree_expr_nonzero_p (TREE_OPERAND (t, 0));
9682 /* See if we are applying CODE, a relational to the highest or lowest
9683 possible integer of TYPE. If so, then the result is a compile
9687 fold_relational_hi_lo (enum tree_code *code_p, const tree type, tree *op0_p,
9692 enum tree_code code = *code_p;
9693 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (op1)));
9695 if (TREE_CODE (op1) == INTEGER_CST
9696 && ! TREE_CONSTANT_OVERFLOW (op1)
9697 && width <= HOST_BITS_PER_WIDE_INT
9698 && (INTEGRAL_TYPE_P (TREE_TYPE (op1))
9699 || POINTER_TYPE_P (TREE_TYPE (op1))))
9701 unsigned HOST_WIDE_INT signed_max;
9702 unsigned HOST_WIDE_INT max, min;
9704 signed_max = ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1;
9706 if (TYPE_UNSIGNED (TREE_TYPE (op1)))
9708 max = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
9714 min = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
9717 if (TREE_INT_CST_HIGH (op1) == 0
9718 && TREE_INT_CST_LOW (op1) == max)
9722 return omit_one_operand (type, integer_zero_node, op0);
9728 return omit_one_operand (type, integer_one_node, op0);
9734 /* The GE_EXPR and LT_EXPR cases above are not normally
9735 reached because of previous transformations. */
9740 else if (TREE_INT_CST_HIGH (op1) == 0
9741 && TREE_INT_CST_LOW (op1) == max - 1)
9746 *op1_p = const_binop (PLUS_EXPR, op1, integer_one_node, 0);
9750 *op1_p = const_binop (PLUS_EXPR, op1, integer_one_node, 0);
9755 else if (TREE_INT_CST_HIGH (op1) == (min ? -1 : 0)
9756 && TREE_INT_CST_LOW (op1) == min)
9760 return omit_one_operand (type, integer_zero_node, op0);
9767 return omit_one_operand (type, integer_one_node, op0);
9776 else if (TREE_INT_CST_HIGH (op1) == (min ? -1 : 0)
9777 && TREE_INT_CST_LOW (op1) == min + 1)
9782 *op1_p = const_binop (MINUS_EXPR, op1, integer_one_node, 0);
9786 *op1_p = const_binop (MINUS_EXPR, op1, integer_one_node, 0);
9792 else if (TREE_INT_CST_HIGH (op1) == 0
9793 && TREE_INT_CST_LOW (op1) == signed_max
9794 && TYPE_UNSIGNED (TREE_TYPE (op1))
9795 /* signed_type does not work on pointer types. */
9796 && INTEGRAL_TYPE_P (TREE_TYPE (op1)))
9798 /* The following case also applies to X < signed_max+1
9799 and X >= signed_max+1 because previous transformations. */
9800 if (code == LE_EXPR || code == GT_EXPR)
9802 tree st0, st1, exp, retval;
9803 st0 = lang_hooks.types.signed_type (TREE_TYPE (op0));
9804 st1 = lang_hooks.types.signed_type (TREE_TYPE (op1));
9806 exp = build2 (code == LE_EXPR ? GE_EXPR: LT_EXPR,
9808 fold_convert (st0, op0),
9809 fold_convert (st1, integer_zero_node));
9812 = nondestructive_fold_binary_to_constant (TREE_CODE (exp),
9814 TREE_OPERAND (exp, 0),
9815 TREE_OPERAND (exp, 1));
9817 /* If we are in gimple form, then returning EXP would create
9818 non-gimple expressions. Clearing it is safe and insures
9819 we do not allow a non-gimple expression to escape. */
9823 return (retval ? retval : exp);
9832 /* Given the components of a binary expression CODE, TYPE, OP0 and OP1,
9833 attempt to fold the expression to a constant without modifying TYPE,
9836 If the expression could be simplified to a constant, then return
9837 the constant. If the expression would not be simplified to a
9838 constant, then return NULL_TREE.
9840 Note this is primarily designed to be called after gimplification
9841 of the tree structures and when at least one operand is a constant.
9842 As a result of those simplifying assumptions this routine is far
9843 simpler than the generic fold routine. */
9846 nondestructive_fold_binary_to_constant (enum tree_code code, tree type,
9854 /* If this is a commutative operation, and ARG0 is a constant, move it
9855 to ARG1 to reduce the number of tests below. */
9856 if (commutative_tree_code (code)
9857 && (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST))
9864 /* If either operand is a complex type, extract its real component. */
9865 if (TREE_CODE (op0) == COMPLEX_CST)
9866 subop0 = TREE_REALPART (op0);
9870 if (TREE_CODE (op1) == COMPLEX_CST)
9871 subop1 = TREE_REALPART (op1);
9875 /* Note if either argument is not a real or integer constant.
9876 With a few exceptions, simplification is limited to cases
9877 where both arguments are constants. */
9878 if ((TREE_CODE (subop0) != INTEGER_CST
9879 && TREE_CODE (subop0) != REAL_CST)
9880 || (TREE_CODE (subop1) != INTEGER_CST
9881 && TREE_CODE (subop1) != REAL_CST))
9887 /* (plus (address) (const_int)) is a constant. */
9888 if (TREE_CODE (op0) == PLUS_EXPR
9889 && TREE_CODE (op1) == INTEGER_CST
9890 && (TREE_CODE (TREE_OPERAND (op0, 0)) == ADDR_EXPR
9891 || (TREE_CODE (TREE_OPERAND (op0, 0)) == NOP_EXPR
9892 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (op0, 0), 0))
9894 && TREE_CODE (TREE_OPERAND (op0, 1)) == INTEGER_CST)
9896 return build2 (PLUS_EXPR, type, TREE_OPERAND (op0, 0),
9897 const_binop (PLUS_EXPR, op1,
9898 TREE_OPERAND (op0, 1), 0));
9906 /* Both arguments are constants. Simplify. */
9907 tem = const_binop (code, op0, op1, 0);
9908 if (tem != NULL_TREE)
9910 /* The return value should always have the same type as
9911 the original expression. */
9912 if (TREE_TYPE (tem) != type)
9913 tem = fold_convert (type, tem);
9920 /* Fold &x - &x. This can happen from &x.foo - &x.
9921 This is unsafe for certain floats even in non-IEEE formats.
9922 In IEEE, it is unsafe because it does wrong for NaNs.
9923 Also note that operand_equal_p is always false if an
9924 operand is volatile. */
9925 if (! FLOAT_TYPE_P (type) && operand_equal_p (op0, op1, 0))
9926 return fold_convert (type, integer_zero_node);
9932 /* Special case multiplication or bitwise AND where one argument
9934 if (! FLOAT_TYPE_P (type) && integer_zerop (op1))
9935 return omit_one_operand (type, op1, op0);
9937 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (op0)))
9938 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (op0)))
9939 && real_zerop (op1))
9940 return omit_one_operand (type, op1, op0);
9945 /* Special case when we know the result will be all ones. */
9946 if (integer_all_onesp (op1))
9947 return omit_one_operand (type, op1, op0);
9951 case TRUNC_DIV_EXPR:
9952 case ROUND_DIV_EXPR:
9953 case FLOOR_DIV_EXPR:
9955 case EXACT_DIV_EXPR:
9956 case TRUNC_MOD_EXPR:
9957 case ROUND_MOD_EXPR:
9958 case FLOOR_MOD_EXPR:
9961 /* Division by zero is undefined. */
9962 if (integer_zerop (op1))
9965 if (TREE_CODE (op1) == REAL_CST
9966 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (op1)))
9967 && real_zerop (op1))
9973 if (INTEGRAL_TYPE_P (type)
9974 && operand_equal_p (op1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
9975 return omit_one_operand (type, op1, op0);
9980 if (INTEGRAL_TYPE_P (type)
9981 && TYPE_MAX_VALUE (type)
9982 && operand_equal_p (op1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
9983 return omit_one_operand (type, op1, op0);
9988 /* Optimize -1 >> x for arithmetic right shifts. */
9989 if (integer_all_onesp (op0) && ! TYPE_UNSIGNED (type))
9990 return omit_one_operand (type, op0, op1);
9991 /* ... fall through ... */
9994 if (integer_zerop (op0))
9995 return omit_one_operand (type, op0, op1);
9997 /* Since negative shift count is not well-defined, don't
9998 try to compute it in the compiler. */
9999 if (TREE_CODE (op1) == INTEGER_CST && tree_int_cst_sgn (op1) < 0)
10006 /* -1 rotated either direction by any amount is still -1. */
10007 if (integer_all_onesp (op0))
10008 return omit_one_operand (type, op0, op1);
10010 /* 0 rotated either direction by any amount is still zero. */
10011 if (integer_zerop (op0))
10012 return omit_one_operand (type, op0, op1);
10018 return build_complex (type, op0, op1);
10027 /* If one arg is a real or integer constant, put it last. */
10028 if ((TREE_CODE (op0) == INTEGER_CST
10029 && TREE_CODE (op1) != INTEGER_CST)
10030 || (TREE_CODE (op0) == REAL_CST
10031 && TREE_CODE (op0) != REAL_CST))
10038 code = swap_tree_comparison (code);
10041 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
10042 This transformation affects the cases which are handled in later
10043 optimizations involving comparisons with non-negative constants. */
10044 if (TREE_CODE (op1) == INTEGER_CST
10045 && TREE_CODE (op0) != INTEGER_CST
10046 && tree_int_cst_sgn (op1) > 0)
10052 op1 = const_binop (MINUS_EXPR, op1, integer_one_node, 0);
10057 op1 = const_binop (MINUS_EXPR, op1, integer_one_node, 0);
10065 tem = fold_relational_hi_lo (&code, type, &op0, &op1);
10069 /* Fall through. */
10072 case UNORDERED_EXPR:
10082 return fold_relational_const (code, type, op0, op1);
10085 /* This could probably be handled. */
10088 case TRUTH_AND_EXPR:
10089 /* If second arg is constant zero, result is zero, but first arg
10090 must be evaluated. */
10091 if (integer_zerop (op1))
10092 return omit_one_operand (type, op1, op0);
10093 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
10094 case will be handled here. */
10095 if (integer_zerop (op0))
10096 return omit_one_operand (type, op0, op1);
10097 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
10098 return constant_boolean_node (true, type);
10101 case TRUTH_OR_EXPR:
10102 /* If second arg is constant true, result is true, but we must
10103 evaluate first arg. */
10104 if (TREE_CODE (op1) == INTEGER_CST && ! integer_zerop (op1))
10105 return omit_one_operand (type, op1, op0);
10106 /* Likewise for first arg, but note this only occurs here for
10108 if (TREE_CODE (op0) == INTEGER_CST && ! integer_zerop (op0))
10109 return omit_one_operand (type, op0, op1);
10110 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
10111 return constant_boolean_node (false, type);
10114 case TRUTH_XOR_EXPR:
10115 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
10117 int x = ! integer_zerop (op0) ^ ! integer_zerop (op1);
10118 return constant_boolean_node (x, type);
10127 /* Given the components of a unary expression CODE, TYPE and OP0,
10128 attempt to fold the expression to a constant without modifying
10131 If the expression could be simplified to a constant, then return
10132 the constant. If the expression would not be simplified to a
10133 constant, then return NULL_TREE.
10135 Note this is primarily designed to be called after gimplification
10136 of the tree structures and when op0 is a constant. As a result
10137 of those simplifying assumptions this routine is far simpler than
10138 the generic fold routine. */
10141 nondestructive_fold_unary_to_constant (enum tree_code code, tree type,
10144 /* Make sure we have a suitable constant argument. */
10145 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
10149 if (TREE_CODE (op0) == COMPLEX_CST)
10150 subop = TREE_REALPART (op0);
10154 if (TREE_CODE (subop) != INTEGER_CST && TREE_CODE (subop) != REAL_CST)
10163 case FIX_TRUNC_EXPR:
10164 case FIX_FLOOR_EXPR:
10165 case FIX_CEIL_EXPR:
10166 return fold_convert_const (code, type, op0);
10169 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
10170 return fold_negate_const (op0, type);
10175 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
10176 return fold_abs_const (op0, type);
10181 if (TREE_CODE (op0) == INTEGER_CST)
10182 return fold_not_const (op0, type);
10186 case REALPART_EXPR:
10187 if (TREE_CODE (op0) == COMPLEX_CST)
10188 return TREE_REALPART (op0);
10192 case IMAGPART_EXPR:
10193 if (TREE_CODE (op0) == COMPLEX_CST)
10194 return TREE_IMAGPART (op0);
10199 if (TREE_CODE (op0) == COMPLEX_CST
10200 && TREE_CODE (TREE_TYPE (op0)) == COMPLEX_TYPE)
10201 return build_complex (type, TREE_REALPART (op0),
10202 negate_expr (TREE_IMAGPART (op0)));
10210 /* If EXP represents referencing an element in a constant string
10211 (either via pointer arithmetic or array indexing), return the
10212 tree representing the value accessed, otherwise return NULL. */
10215 fold_read_from_constant_string (tree exp)
10217 if (TREE_CODE (exp) == INDIRECT_REF || TREE_CODE (exp) == ARRAY_REF)
10219 tree exp1 = TREE_OPERAND (exp, 0);
10223 if (TREE_CODE (exp) == INDIRECT_REF)
10224 string = string_constant (exp1, &index);
10227 tree low_bound = array_ref_low_bound (exp);
10228 index = fold_convert (sizetype, TREE_OPERAND (exp, 1));
10230 /* Optimize the special-case of a zero lower bound.
10232 We convert the low_bound to sizetype to avoid some problems
10233 with constant folding. (E.g. suppose the lower bound is 1,
10234 and its mode is QI. Without the conversion,l (ARRAY
10235 +(INDEX-(unsigned char)1)) becomes ((ARRAY+(-(unsigned char)1))
10236 +INDEX), which becomes (ARRAY+255+INDEX). Opps!) */
10237 if (! integer_zerop (low_bound))
10238 index = size_diffop (index, fold_convert (sizetype, low_bound));
10244 && TREE_TYPE (exp) == TREE_TYPE (TREE_TYPE (string))
10245 && TREE_CODE (string) == STRING_CST
10246 && TREE_CODE (index) == INTEGER_CST
10247 && compare_tree_int (index, TREE_STRING_LENGTH (string)) < 0
10248 && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (string))))
10250 && (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))) == 1))
10251 return fold_convert (TREE_TYPE (exp),
10252 build_int_cst (NULL_TREE,
10253 (TREE_STRING_POINTER (string)
10254 [TREE_INT_CST_LOW (index)])));
10259 /* Return the tree for neg (ARG0) when ARG0 is known to be either
10260 an integer constant or real constant.
10262 TYPE is the type of the result. */
10265 fold_negate_const (tree arg0, tree type)
10267 tree t = NULL_TREE;
10269 switch (TREE_CODE (arg0))
10273 unsigned HOST_WIDE_INT low;
10274 HOST_WIDE_INT high;
10275 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
10276 TREE_INT_CST_HIGH (arg0),
10278 t = build_int_cst_wide (type, low, high);
10279 t = force_fit_type (t, 1,
10280 (overflow | TREE_OVERFLOW (arg0))
10281 && !TYPE_UNSIGNED (type),
10282 TREE_CONSTANT_OVERFLOW (arg0));
10287 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
10291 gcc_unreachable ();
10297 /* Return the tree for abs (ARG0) when ARG0 is known to be either
10298 an integer constant or real constant.
10300 TYPE is the type of the result. */
10303 fold_abs_const (tree arg0, tree type)
10305 tree t = NULL_TREE;
10307 switch (TREE_CODE (arg0))
10310 /* If the value is unsigned, then the absolute value is
10311 the same as the ordinary value. */
10312 if (TYPE_UNSIGNED (type))
10314 /* Similarly, if the value is non-negative. */
10315 else if (INT_CST_LT (integer_minus_one_node, arg0))
10317 /* If the value is negative, then the absolute value is
10321 unsigned HOST_WIDE_INT low;
10322 HOST_WIDE_INT high;
10323 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
10324 TREE_INT_CST_HIGH (arg0),
10326 t = build_int_cst_wide (type, low, high);
10327 t = force_fit_type (t, -1, overflow | TREE_OVERFLOW (arg0),
10328 TREE_CONSTANT_OVERFLOW (arg0));
10333 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
10334 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
10340 gcc_unreachable ();
10346 /* Return the tree for not (ARG0) when ARG0 is known to be an integer
10347 constant. TYPE is the type of the result. */
10350 fold_not_const (tree arg0, tree type)
10352 tree t = NULL_TREE;
10354 gcc_assert (TREE_CODE (arg0) == INTEGER_CST);
10356 t = build_int_cst_wide (type,
10357 ~ TREE_INT_CST_LOW (arg0),
10358 ~ TREE_INT_CST_HIGH (arg0));
10359 t = force_fit_type (t, 0, TREE_OVERFLOW (arg0),
10360 TREE_CONSTANT_OVERFLOW (arg0));
10365 /* Given CODE, a relational operator, the target type, TYPE and two
10366 constant operands OP0 and OP1, return the result of the
10367 relational operation. If the result is not a compile time
10368 constant, then return NULL_TREE. */
10371 fold_relational_const (enum tree_code code, tree type, tree op0, tree op1)
10373 int result, invert;
10375 /* From here on, the only cases we handle are when the result is
10376 known to be a constant. */
10378 if (TREE_CODE (op0) == REAL_CST && TREE_CODE (op1) == REAL_CST)
10380 const REAL_VALUE_TYPE *c0 = TREE_REAL_CST_PTR (op0);
10381 const REAL_VALUE_TYPE *c1 = TREE_REAL_CST_PTR (op1);
10383 /* Handle the cases where either operand is a NaN. */
10384 if (real_isnan (c0) || real_isnan (c1))
10394 case UNORDERED_EXPR:
10408 if (flag_trapping_math)
10414 gcc_unreachable ();
10417 return constant_boolean_node (result, type);
10420 return constant_boolean_node (real_compare (code, c0, c1), type);
10423 /* From here on we only handle LT, LE, GT, GE, EQ and NE.
10425 To compute GT, swap the arguments and do LT.
10426 To compute GE, do LT and invert the result.
10427 To compute LE, swap the arguments, do LT and invert the result.
10428 To compute NE, do EQ and invert the result.
10430 Therefore, the code below must handle only EQ and LT. */
10432 if (code == LE_EXPR || code == GT_EXPR)
10437 code = swap_tree_comparison (code);
10440 /* Note that it is safe to invert for real values here because we
10441 have already handled the one case that it matters. */
10444 if (code == NE_EXPR || code == GE_EXPR)
10447 code = invert_tree_comparison (code, false);
10450 /* Compute a result for LT or EQ if args permit;
10451 Otherwise return T. */
10452 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
10454 if (code == EQ_EXPR)
10455 result = tree_int_cst_equal (op0, op1);
10456 else if (TYPE_UNSIGNED (TREE_TYPE (op0)))
10457 result = INT_CST_LT_UNSIGNED (op0, op1);
10459 result = INT_CST_LT (op0, op1);
10466 return constant_boolean_node (result, type);
10469 /* Build an expression for the address of T. Folds away INDIRECT_REF to
10470 avoid confusing the gimplify process. */
10473 build_fold_addr_expr_with_type (tree t, tree ptrtype)
10475 /* The size of the object is not relevant when talking about its address. */
10476 if (TREE_CODE (t) == WITH_SIZE_EXPR)
10477 t = TREE_OPERAND (t, 0);
10479 if (TREE_CODE (t) == INDIRECT_REF)
10481 t = TREE_OPERAND (t, 0);
10482 if (TREE_TYPE (t) != ptrtype)
10483 t = build1 (NOP_EXPR, ptrtype, t);
10489 while (handled_component_p (base)
10490 || TREE_CODE (base) == REALPART_EXPR
10491 || TREE_CODE (base) == IMAGPART_EXPR)
10492 base = TREE_OPERAND (base, 0);
10494 TREE_ADDRESSABLE (base) = 1;
10496 t = build1 (ADDR_EXPR, ptrtype, t);
10503 build_fold_addr_expr (tree t)
10505 return build_fold_addr_expr_with_type (t, build_pointer_type (TREE_TYPE (t)));
10508 /* Builds an expression for an indirection through T, simplifying some
10512 build_fold_indirect_ref (tree t)
10514 tree type = TREE_TYPE (TREE_TYPE (t));
10519 if (TREE_CODE (sub) == ADDR_EXPR)
10521 tree op = TREE_OPERAND (sub, 0);
10522 tree optype = TREE_TYPE (op);
10524 if (lang_hooks.types_compatible_p (type, optype))
10526 /* *(foo *)&fooarray => fooarray[0] */
10527 else if (TREE_CODE (optype) == ARRAY_TYPE
10528 && lang_hooks.types_compatible_p (type, TREE_TYPE (optype)))
10529 return build4 (ARRAY_REF, type, op, size_zero_node, NULL_TREE, NULL_TREE);
10532 /* *(foo *)fooarrptr => (*fooarrptr)[0] */
10533 subtype = TREE_TYPE (sub);
10534 if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE
10535 && lang_hooks.types_compatible_p (type, TREE_TYPE (TREE_TYPE (subtype))))
10537 sub = build_fold_indirect_ref (sub);
10538 return build4 (ARRAY_REF, type, sub, size_zero_node, NULL_TREE, NULL_TREE);
10541 return build1 (INDIRECT_REF, type, t);
10544 /* Strip non-trapping, non-side-effecting tree nodes from an expression
10545 whose result is ignored. The type of the returned tree need not be
10546 the same as the original expression. */
10549 fold_ignored_result (tree t)
10551 if (!TREE_SIDE_EFFECTS (t))
10552 return integer_zero_node;
10555 switch (TREE_CODE_CLASS (TREE_CODE (t)))
10558 t = TREE_OPERAND (t, 0);
10563 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
10564 t = TREE_OPERAND (t, 0);
10565 else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0)))
10566 t = TREE_OPERAND (t, 1);
10572 switch (TREE_CODE (t))
10574 case COMPOUND_EXPR:
10575 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
10577 t = TREE_OPERAND (t, 0);
10581 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1))
10582 || TREE_SIDE_EFFECTS (TREE_OPERAND (t, 2)))
10584 t = TREE_OPERAND (t, 0);
10597 /* Return the value of VALUE, rounded up to a multiple of DIVISOR.
10598 This can only be applied to objects of a sizetype. */
10601 round_up (tree value, int divisor)
10603 tree div = NULL_TREE;
10605 gcc_assert (divisor > 0);
10609 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
10610 have to do anything. Only do this when we are not given a const,
10611 because in that case, this check is more expensive than just
10613 if (TREE_CODE (value) != INTEGER_CST)
10615 div = build_int_cst (TREE_TYPE (value), divisor);
10617 if (multiple_of_p (TREE_TYPE (value), value, div))
10621 /* If divisor is a power of two, simplify this to bit manipulation. */
10622 if (divisor == (divisor & -divisor))
10626 t = build_int_cst (TREE_TYPE (value), divisor - 1);
10627 value = size_binop (PLUS_EXPR, value, t);
10628 t = build_int_cst (TREE_TYPE (value), -divisor);
10629 value = size_binop (BIT_AND_EXPR, value, t);
10634 div = build_int_cst (TREE_TYPE (value), divisor);
10635 value = size_binop (CEIL_DIV_EXPR, value, div);
10636 value = size_binop (MULT_EXPR, value, div);
10642 /* Likewise, but round down. */
10645 round_down (tree value, int divisor)
10647 tree div = NULL_TREE;
10649 gcc_assert (divisor > 0);
10653 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
10654 have to do anything. Only do this when we are not given a const,
10655 because in that case, this check is more expensive than just
10657 if (TREE_CODE (value) != INTEGER_CST)
10659 div = build_int_cst (TREE_TYPE (value), divisor);
10661 if (multiple_of_p (TREE_TYPE (value), value, div))
10665 /* If divisor is a power of two, simplify this to bit manipulation. */
10666 if (divisor == (divisor & -divisor))
10670 t = build_int_cst (TREE_TYPE (value), -divisor);
10671 value = size_binop (BIT_AND_EXPR, value, t);
10676 div = build_int_cst (TREE_TYPE (value), divisor);
10677 value = size_binop (FLOOR_DIV_EXPR, value, div);
10678 value = size_binop (MULT_EXPR, value, div);
10684 /* Returns true if addresses of E1 and E2 differ by a constant, false
10685 otherwise. If they do, &E1 - &E2 is stored in *DIFF. */
10688 ptr_difference_const (tree e1, tree e2, HOST_WIDE_INT *diff)
10691 HOST_WIDE_INT bitsize1, bitsize2;
10692 HOST_WIDE_INT bitpos1, bitpos2;
10693 tree toffset1, toffset2, tdiff, type;
10694 enum machine_mode mode1, mode2;
10695 int unsignedp1, unsignedp2, volatilep1, volatilep2;
10697 core1 = get_inner_reference (e1, &bitsize1, &bitpos1, &toffset1, &mode1,
10698 &unsignedp1, &volatilep1);
10699 core2 = get_inner_reference (e2, &bitsize2, &bitpos2, &toffset2, &mode2,
10700 &unsignedp2, &volatilep2);
10702 if (bitpos1 % BITS_PER_UNIT != 0
10703 || bitpos2 % BITS_PER_UNIT != 0
10704 || !operand_equal_p (core1, core2, 0))
10707 if (toffset1 && toffset2)
10709 type = TREE_TYPE (toffset1);
10710 if (type != TREE_TYPE (toffset2))
10711 toffset2 = fold_convert (type, toffset2);
10713 tdiff = fold (build2 (MINUS_EXPR, type, toffset1, toffset2));
10714 if (!host_integerp (tdiff, 0))
10717 *diff = tree_low_cst (tdiff, 0);
10719 else if (toffset1 || toffset2)
10721 /* If only one of the offsets is non-constant, the difference cannot
10728 *diff += (bitpos1 - bitpos2) / BITS_PER_UNIT;