1 /* Fold a constant sub-tree into a single node for C-compiler
2 Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
3 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
22 /*@@ This file should be rewritten to use an arbitrary precision
23 @@ representation for "struct tree_int_cst" and "struct tree_real_cst".
24 @@ Perhaps the routines could also be used for bc/dc, and made a lib.
25 @@ The routines that translate from the ap rep should
26 @@ warn if precision et. al. is lost.
27 @@ This would also make life easier when this technology is used
28 @@ for cross-compilers. */
30 /* The entry points in this file are fold, size_int_wide, size_binop
33 fold takes a tree as argument and returns a simplified tree.
35 size_binop takes a tree code for an arithmetic operation
36 and two operands that are trees, and produces a tree for the
37 result, assuming the type comes from `sizetype'.
39 size_int takes an integer value, and creates a tree constant
40 with type from `sizetype'.
42 force_fit_type takes a constant and prior overflow indicator, and
43 forces the value to fit the type. It returns an overflow indicator. */
47 #include "coretypes.h"
58 #include "langhooks.h"
61 static void encode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT, HOST_WIDE_INT);
62 static void decode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
63 static bool negate_mathfn_p (enum built_in_function);
64 static bool negate_expr_p (tree);
65 static tree negate_expr (tree);
66 static tree split_tree (tree, enum tree_code, tree *, tree *, tree *, int);
67 static tree associate_trees (tree, tree, enum tree_code, tree);
68 static tree int_const_binop (enum tree_code, tree, tree, int);
69 static tree const_binop (enum tree_code, tree, tree, int);
70 static hashval_t size_htab_hash (const void *);
71 static int size_htab_eq (const void *, const void *);
72 static tree fold_convert_const (enum tree_code, tree, tree);
73 static tree fold_convert (tree, tree);
74 static enum tree_code invert_tree_comparison (enum tree_code);
75 static enum tree_code swap_tree_comparison (enum tree_code);
76 static int comparison_to_compcode (enum tree_code);
77 static enum tree_code compcode_to_comparison (int);
78 static int truth_value_p (enum tree_code);
79 static int operand_equal_for_comparison_p (tree, tree, tree);
80 static int twoval_comparison_p (tree, tree *, tree *, int *);
81 static tree eval_subst (tree, tree, tree, tree, tree);
82 static tree pedantic_omit_one_operand (tree, tree, tree);
83 static tree distribute_bit_expr (enum tree_code, tree, tree, tree);
84 static tree make_bit_field_ref (tree, tree, int, int, int);
85 static tree optimize_bit_field_compare (enum tree_code, tree, tree, tree);
86 static tree decode_field_reference (tree, HOST_WIDE_INT *, HOST_WIDE_INT *,
87 enum machine_mode *, int *, int *,
89 static int all_ones_mask_p (tree, int);
90 static tree sign_bit_p (tree, tree);
91 static int simple_operand_p (tree);
92 static tree range_binop (enum tree_code, tree, tree, int, tree, int);
93 static tree make_range (tree, int *, tree *, tree *);
94 static tree build_range_check (tree, tree, int, tree, tree);
95 static int merge_ranges (int *, tree *, tree *, int, tree, tree, int, tree,
97 static tree fold_range_test (tree);
98 static tree unextend (tree, int, int, tree);
99 static tree fold_truthop (enum tree_code, tree, tree, tree);
100 static tree optimize_minmax_comparison (tree);
101 static tree extract_muldiv (tree, tree, enum tree_code, tree);
102 static tree extract_muldiv_1 (tree, tree, enum tree_code, tree);
103 static tree strip_compound_expr (tree, tree);
104 static int multiple_of_p (tree, tree, tree);
105 static tree constant_boolean_node (int, tree);
106 static int count_cond (tree, int);
107 static tree fold_binary_op_with_conditional_arg (enum tree_code, tree, tree,
109 static bool fold_real_zero_addition_p (tree, tree, int);
110 static tree fold_mathfn_compare (enum built_in_function, enum tree_code,
112 static tree fold_inf_compare (enum tree_code, tree, tree, tree);
113 static bool reorder_operands_p (tree, tree);
114 static bool tree_swap_operands_p (tree, tree, bool);
116 /* The following constants represent a bit based encoding of GCC's
117 comparison operators. This encoding simplifies transformations
118 on relational comparison operators, such as AND and OR. */
119 #define COMPCODE_FALSE 0
120 #define COMPCODE_LT 1
121 #define COMPCODE_EQ 2
122 #define COMPCODE_LE 3
123 #define COMPCODE_GT 4
124 #define COMPCODE_NE 5
125 #define COMPCODE_GE 6
126 #define COMPCODE_TRUE 7
128 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
129 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
130 and SUM1. Then this yields nonzero if overflow occurred during the
133 Overflow occurs if A and B have the same sign, but A and SUM differ in
134 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
136 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
138 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
139 We do that by representing the two-word integer in 4 words, with only
140 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
141 number. The value of the word is LOWPART + HIGHPART * BASE. */
144 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
145 #define HIGHPART(x) \
146 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
147 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
149 /* Unpack a two-word integer into 4 words.
150 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
151 WORDS points to the array of HOST_WIDE_INTs. */
154 encode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT low, HOST_WIDE_INT hi)
156 words[0] = LOWPART (low);
157 words[1] = HIGHPART (low);
158 words[2] = LOWPART (hi);
159 words[3] = HIGHPART (hi);
162 /* Pack an array of 4 words into a two-word integer.
163 WORDS points to the array of words.
164 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
167 decode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT *low,
170 *low = words[0] + words[1] * BASE;
171 *hi = words[2] + words[3] * BASE;
174 /* Make the integer constant T valid for its type by setting to 0 or 1 all
175 the bits in the constant that don't belong in the type.
177 Return 1 if a signed overflow occurs, 0 otherwise. If OVERFLOW is
178 nonzero, a signed overflow has already occurred in calculating T, so
182 force_fit_type (tree t, int overflow)
184 unsigned HOST_WIDE_INT low;
188 if (TREE_CODE (t) == REAL_CST)
190 /* ??? Used to check for overflow here via CHECK_FLOAT_TYPE.
191 Consider doing it via real_convert now. */
195 else if (TREE_CODE (t) != INTEGER_CST)
198 low = TREE_INT_CST_LOW (t);
199 high = TREE_INT_CST_HIGH (t);
201 if (POINTER_TYPE_P (TREE_TYPE (t))
202 || TREE_CODE (TREE_TYPE (t)) == OFFSET_TYPE)
205 prec = TYPE_PRECISION (TREE_TYPE (t));
207 /* First clear all bits that are beyond the type's precision. */
209 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
211 else if (prec > HOST_BITS_PER_WIDE_INT)
212 TREE_INT_CST_HIGH (t)
213 &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
216 TREE_INT_CST_HIGH (t) = 0;
217 if (prec < HOST_BITS_PER_WIDE_INT)
218 TREE_INT_CST_LOW (t) &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
221 /* Unsigned types do not suffer sign extension or overflow unless they
223 if (TREE_UNSIGNED (TREE_TYPE (t))
224 && ! (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
225 && TYPE_IS_SIZETYPE (TREE_TYPE (t))))
228 /* If the value's sign bit is set, extend the sign. */
229 if (prec != 2 * HOST_BITS_PER_WIDE_INT
230 && (prec > HOST_BITS_PER_WIDE_INT
231 ? 0 != (TREE_INT_CST_HIGH (t)
233 << (prec - HOST_BITS_PER_WIDE_INT - 1)))
234 : 0 != (TREE_INT_CST_LOW (t)
235 & ((unsigned HOST_WIDE_INT) 1 << (prec - 1)))))
237 /* Value is negative:
238 set to 1 all the bits that are outside this type's precision. */
239 if (prec > HOST_BITS_PER_WIDE_INT)
240 TREE_INT_CST_HIGH (t)
241 |= ((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
244 TREE_INT_CST_HIGH (t) = -1;
245 if (prec < HOST_BITS_PER_WIDE_INT)
246 TREE_INT_CST_LOW (t) |= ((unsigned HOST_WIDE_INT) (-1) << prec);
250 /* Return nonzero if signed overflow occurred. */
252 ((overflow | (low ^ TREE_INT_CST_LOW (t)) | (high ^ TREE_INT_CST_HIGH (t)))
256 /* Add two doubleword integers with doubleword result.
257 Each argument is given as two `HOST_WIDE_INT' pieces.
258 One argument is L1 and H1; the other, L2 and H2.
259 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
262 add_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
263 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
264 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
266 unsigned HOST_WIDE_INT l;
270 h = h1 + h2 + (l < l1);
274 return OVERFLOW_SUM_SIGN (h1, h2, h);
277 /* Negate a doubleword integer with doubleword result.
278 Return nonzero if the operation overflows, assuming it's signed.
279 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
280 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
283 neg_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
284 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
290 return (*hv & h1) < 0;
300 /* Multiply two doubleword integers with doubleword result.
301 Return nonzero if the operation overflows, assuming it's signed.
302 Each argument is given as two `HOST_WIDE_INT' pieces.
303 One argument is L1 and H1; the other, L2 and H2.
304 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
307 mul_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
308 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
309 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
311 HOST_WIDE_INT arg1[4];
312 HOST_WIDE_INT arg2[4];
313 HOST_WIDE_INT prod[4 * 2];
314 unsigned HOST_WIDE_INT carry;
316 unsigned HOST_WIDE_INT toplow, neglow;
317 HOST_WIDE_INT tophigh, neghigh;
319 encode (arg1, l1, h1);
320 encode (arg2, l2, h2);
322 memset (prod, 0, sizeof prod);
324 for (i = 0; i < 4; i++)
327 for (j = 0; j < 4; j++)
330 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
331 carry += arg1[i] * arg2[j];
332 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
334 prod[k] = LOWPART (carry);
335 carry = HIGHPART (carry);
340 decode (prod, lv, hv); /* This ignores prod[4] through prod[4*2-1] */
342 /* Check for overflow by calculating the top half of the answer in full;
343 it should agree with the low half's sign bit. */
344 decode (prod + 4, &toplow, &tophigh);
347 neg_double (l2, h2, &neglow, &neghigh);
348 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
352 neg_double (l1, h1, &neglow, &neghigh);
353 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
355 return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
358 /* Shift the doubleword integer in L1, H1 left by COUNT places
359 keeping only PREC bits of result.
360 Shift right if COUNT is negative.
361 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
362 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
365 lshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
366 HOST_WIDE_INT count, unsigned int prec,
367 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv, int arith)
369 unsigned HOST_WIDE_INT signmask;
373 rshift_double (l1, h1, -count, prec, lv, hv, arith);
377 if (SHIFT_COUNT_TRUNCATED)
380 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
382 /* Shifting by the host word size is undefined according to the
383 ANSI standard, so we must handle this as a special case. */
387 else if (count >= HOST_BITS_PER_WIDE_INT)
389 *hv = l1 << (count - HOST_BITS_PER_WIDE_INT);
394 *hv = (((unsigned HOST_WIDE_INT) h1 << count)
395 | (l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
399 /* Sign extend all bits that are beyond the precision. */
401 signmask = -((prec > HOST_BITS_PER_WIDE_INT
402 ? ((unsigned HOST_WIDE_INT) *hv
403 >> (prec - HOST_BITS_PER_WIDE_INT - 1))
404 : (*lv >> (prec - 1))) & 1);
406 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
408 else if (prec >= HOST_BITS_PER_WIDE_INT)
410 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
411 *hv |= signmask << (prec - HOST_BITS_PER_WIDE_INT);
416 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
417 *lv |= signmask << prec;
421 /* Shift the doubleword integer in L1, H1 right by COUNT places
422 keeping only PREC bits of result. COUNT must be positive.
423 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
424 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
427 rshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
428 HOST_WIDE_INT count, unsigned int prec,
429 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
432 unsigned HOST_WIDE_INT signmask;
435 ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
438 if (SHIFT_COUNT_TRUNCATED)
441 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
443 /* Shifting by the host word size is undefined according to the
444 ANSI standard, so we must handle this as a special case. */
448 else if (count >= HOST_BITS_PER_WIDE_INT)
451 *lv = (unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT);
455 *hv = (unsigned HOST_WIDE_INT) h1 >> count;
457 | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
460 /* Zero / sign extend all bits that are beyond the precision. */
462 if (count >= (HOST_WIDE_INT)prec)
467 else if ((prec - count) >= 2 * HOST_BITS_PER_WIDE_INT)
469 else if ((prec - count) >= HOST_BITS_PER_WIDE_INT)
471 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - count - HOST_BITS_PER_WIDE_INT));
472 *hv |= signmask << (prec - count - HOST_BITS_PER_WIDE_INT);
477 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << (prec - count));
478 *lv |= signmask << (prec - count);
482 /* Rotate the doubleword integer in L1, H1 left by COUNT places
483 keeping only PREC bits of result.
484 Rotate right if COUNT is negative.
485 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
488 lrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
489 HOST_WIDE_INT count, unsigned int prec,
490 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
492 unsigned HOST_WIDE_INT s1l, s2l;
493 HOST_WIDE_INT s1h, s2h;
499 lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
500 rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
505 /* Rotate the doubleword integer in L1, H1 left by COUNT places
506 keeping only PREC bits of result. COUNT must be positive.
507 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
510 rrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
511 HOST_WIDE_INT count, unsigned int prec,
512 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
514 unsigned HOST_WIDE_INT s1l, s2l;
515 HOST_WIDE_INT s1h, s2h;
521 rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
522 lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
527 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
528 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
529 CODE is a tree code for a kind of division, one of
530 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
532 It controls how the quotient is rounded to an integer.
533 Return nonzero if the operation overflows.
534 UNS nonzero says do unsigned division. */
537 div_and_round_double (enum tree_code code, int uns,
538 unsigned HOST_WIDE_INT lnum_orig, /* num == numerator == dividend */
539 HOST_WIDE_INT hnum_orig,
540 unsigned HOST_WIDE_INT lden_orig, /* den == denominator == divisor */
541 HOST_WIDE_INT hden_orig,
542 unsigned HOST_WIDE_INT *lquo,
543 HOST_WIDE_INT *hquo, unsigned HOST_WIDE_INT *lrem,
547 HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
548 HOST_WIDE_INT den[4], quo[4];
550 unsigned HOST_WIDE_INT work;
551 unsigned HOST_WIDE_INT carry = 0;
552 unsigned HOST_WIDE_INT lnum = lnum_orig;
553 HOST_WIDE_INT hnum = hnum_orig;
554 unsigned HOST_WIDE_INT lden = lden_orig;
555 HOST_WIDE_INT hden = hden_orig;
558 if (hden == 0 && lden == 0)
559 overflow = 1, lden = 1;
561 /* Calculate quotient sign and convert operands to unsigned. */
567 /* (minimum integer) / (-1) is the only overflow case. */
568 if (neg_double (lnum, hnum, &lnum, &hnum)
569 && ((HOST_WIDE_INT) lden & hden) == -1)
575 neg_double (lden, hden, &lden, &hden);
579 if (hnum == 0 && hden == 0)
580 { /* single precision */
582 /* This unsigned division rounds toward zero. */
588 { /* trivial case: dividend < divisor */
589 /* hden != 0 already checked. */
596 memset (quo, 0, sizeof quo);
598 memset (num, 0, sizeof num); /* to zero 9th element */
599 memset (den, 0, sizeof den);
601 encode (num, lnum, hnum);
602 encode (den, lden, hden);
604 /* Special code for when the divisor < BASE. */
605 if (hden == 0 && lden < (unsigned HOST_WIDE_INT) BASE)
607 /* hnum != 0 already checked. */
608 for (i = 4 - 1; i >= 0; i--)
610 work = num[i] + carry * BASE;
611 quo[i] = work / lden;
617 /* Full double precision division,
618 with thanks to Don Knuth's "Seminumerical Algorithms". */
619 int num_hi_sig, den_hi_sig;
620 unsigned HOST_WIDE_INT quo_est, scale;
622 /* Find the highest nonzero divisor digit. */
623 for (i = 4 - 1;; i--)
630 /* Insure that the first digit of the divisor is at least BASE/2.
631 This is required by the quotient digit estimation algorithm. */
633 scale = BASE / (den[den_hi_sig] + 1);
635 { /* scale divisor and dividend */
637 for (i = 0; i <= 4 - 1; i++)
639 work = (num[i] * scale) + carry;
640 num[i] = LOWPART (work);
641 carry = HIGHPART (work);
646 for (i = 0; i <= 4 - 1; i++)
648 work = (den[i] * scale) + carry;
649 den[i] = LOWPART (work);
650 carry = HIGHPART (work);
651 if (den[i] != 0) den_hi_sig = i;
658 for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--)
660 /* Guess the next quotient digit, quo_est, by dividing the first
661 two remaining dividend digits by the high order quotient digit.
662 quo_est is never low and is at most 2 high. */
663 unsigned HOST_WIDE_INT tmp;
665 num_hi_sig = i + den_hi_sig + 1;
666 work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
667 if (num[num_hi_sig] != den[den_hi_sig])
668 quo_est = work / den[den_hi_sig];
672 /* Refine quo_est so it's usually correct, and at most one high. */
673 tmp = work - quo_est * den[den_hi_sig];
675 && (den[den_hi_sig - 1] * quo_est
676 > (tmp * BASE + num[num_hi_sig - 2])))
679 /* Try QUO_EST as the quotient digit, by multiplying the
680 divisor by QUO_EST and subtracting from the remaining dividend.
681 Keep in mind that QUO_EST is the I - 1st digit. */
684 for (j = 0; j <= den_hi_sig; j++)
686 work = quo_est * den[j] + carry;
687 carry = HIGHPART (work);
688 work = num[i + j] - LOWPART (work);
689 num[i + j] = LOWPART (work);
690 carry += HIGHPART (work) != 0;
693 /* If quo_est was high by one, then num[i] went negative and
694 we need to correct things. */
695 if (num[num_hi_sig] < (HOST_WIDE_INT) carry)
698 carry = 0; /* add divisor back in */
699 for (j = 0; j <= den_hi_sig; j++)
701 work = num[i + j] + den[j] + carry;
702 carry = HIGHPART (work);
703 num[i + j] = LOWPART (work);
706 num [num_hi_sig] += carry;
709 /* Store the quotient digit. */
714 decode (quo, lquo, hquo);
717 /* If result is negative, make it so. */
719 neg_double (*lquo, *hquo, lquo, hquo);
721 /* Compute trial remainder: rem = num - (quo * den) */
722 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
723 neg_double (*lrem, *hrem, lrem, hrem);
724 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
729 case TRUNC_MOD_EXPR: /* round toward zero */
730 case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
734 case FLOOR_MOD_EXPR: /* round toward negative infinity */
735 if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
738 add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
746 case CEIL_MOD_EXPR: /* round toward positive infinity */
747 if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
749 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
757 case ROUND_MOD_EXPR: /* round to closest integer */
759 unsigned HOST_WIDE_INT labs_rem = *lrem;
760 HOST_WIDE_INT habs_rem = *hrem;
761 unsigned HOST_WIDE_INT labs_den = lden, ltwice;
762 HOST_WIDE_INT habs_den = hden, htwice;
764 /* Get absolute values. */
766 neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
768 neg_double (lden, hden, &labs_den, &habs_den);
770 /* If (2 * abs (lrem) >= abs (lden)) */
771 mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
772 labs_rem, habs_rem, <wice, &htwice);
774 if (((unsigned HOST_WIDE_INT) habs_den
775 < (unsigned HOST_WIDE_INT) htwice)
776 || (((unsigned HOST_WIDE_INT) habs_den
777 == (unsigned HOST_WIDE_INT) htwice)
778 && (labs_den < ltwice)))
782 add_double (*lquo, *hquo,
783 (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
786 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
798 /* Compute true remainder: rem = num - (quo * den) */
799 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
800 neg_double (*lrem, *hrem, lrem, hrem);
801 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
805 /* Return true if built-in mathematical function specified by CODE
806 preserves the sign of it argument, i.e. -f(x) == f(-x). */
809 negate_mathfn_p (enum built_in_function code)
833 /* Determine whether an expression T can be cheaply negated using
834 the function negate_expr. */
837 negate_expr_p (tree t)
839 unsigned HOST_WIDE_INT val;
846 type = TREE_TYPE (t);
849 switch (TREE_CODE (t))
852 if (TREE_UNSIGNED (type) || ! flag_trapv)
855 /* Check that -CST will not overflow type. */
856 prec = TYPE_PRECISION (type);
857 if (prec > HOST_BITS_PER_WIDE_INT)
859 if (TREE_INT_CST_LOW (t) != 0)
861 prec -= HOST_BITS_PER_WIDE_INT;
862 val = TREE_INT_CST_HIGH (t);
865 val = TREE_INT_CST_LOW (t);
866 if (prec < HOST_BITS_PER_WIDE_INT)
867 val &= ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
868 return val != ((unsigned HOST_WIDE_INT) 1 << (prec - 1));
875 return negate_expr_p (TREE_REALPART (t))
876 && negate_expr_p (TREE_IMAGPART (t));
879 if (FLOAT_TYPE_P (type) && !flag_unsafe_math_optimizations)
881 /* -(A + B) -> (-B) - A. */
882 if (negate_expr_p (TREE_OPERAND (t, 1))
883 && reorder_operands_p (TREE_OPERAND (t, 0),
884 TREE_OPERAND (t, 1)))
886 /* -(A + B) -> (-A) - B. */
887 return negate_expr_p (TREE_OPERAND (t, 0));
890 /* We can't turn -(A-B) into B-A when we honor signed zeros. */
891 return (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
892 && reorder_operands_p (TREE_OPERAND (t, 0),
893 TREE_OPERAND (t, 1));
896 if (TREE_UNSIGNED (TREE_TYPE (t)))
902 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
903 return negate_expr_p (TREE_OPERAND (t, 1))
904 || negate_expr_p (TREE_OPERAND (t, 0));
908 /* Negate -((double)float) as (double)(-float). */
909 if (TREE_CODE (type) == REAL_TYPE)
911 tree tem = strip_float_extensions (t);
913 return negate_expr_p (tem);
918 /* Negate -f(x) as f(-x). */
919 if (negate_mathfn_p (builtin_mathfn_code (t)))
920 return negate_expr_p (TREE_VALUE (TREE_OPERAND (t, 1)));
929 /* Given T, an expression, return the negation of T. Allow for T to be
930 null, in which case return null. */
941 type = TREE_TYPE (t);
944 switch (TREE_CODE (t))
948 unsigned HOST_WIDE_INT low;
950 int overflow = neg_double (TREE_INT_CST_LOW (t),
951 TREE_INT_CST_HIGH (t),
953 tem = build_int_2 (low, high);
954 TREE_TYPE (tem) = type;
957 | force_fit_type (tem, overflow && !TREE_UNSIGNED (type)));
958 TREE_CONSTANT_OVERFLOW (tem)
959 = TREE_OVERFLOW (tem) | TREE_CONSTANT_OVERFLOW (t);
961 if (! TREE_OVERFLOW (tem)
962 || TREE_UNSIGNED (type)
968 tem = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (t)));
969 /* Two's complement FP formats, such as c4x, may overflow. */
970 if (! TREE_OVERFLOW (tem) || ! flag_trapping_math)
971 return fold_convert (type, tem);
976 tree rpart = negate_expr (TREE_REALPART (t));
977 tree ipart = negate_expr (TREE_IMAGPART (t));
979 if ((TREE_CODE (rpart) == REAL_CST
980 && TREE_CODE (ipart) == REAL_CST)
981 || (TREE_CODE (rpart) == INTEGER_CST
982 && TREE_CODE (ipart) == INTEGER_CST))
983 return build_complex (type, rpart, ipart);
988 return fold_convert (type, TREE_OPERAND (t, 0));
991 if (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
993 /* -(A + B) -> (-B) - A. */
994 if (negate_expr_p (TREE_OPERAND (t, 1))
995 && reorder_operands_p (TREE_OPERAND (t, 0),
996 TREE_OPERAND (t, 1)))
997 return fold_convert (type,
998 fold (build (MINUS_EXPR, TREE_TYPE (t),
999 negate_expr (TREE_OPERAND (t, 1)),
1000 TREE_OPERAND (t, 0))));
1001 /* -(A + B) -> (-A) - B. */
1002 if (negate_expr_p (TREE_OPERAND (t, 0)))
1003 return fold_convert (type,
1004 fold (build (MINUS_EXPR, TREE_TYPE (t),
1005 negate_expr (TREE_OPERAND (t, 0)),
1006 TREE_OPERAND (t, 1))));
1011 /* - (A - B) -> B - A */
1012 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
1013 && reorder_operands_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1)))
1014 return fold_convert (type,
1015 fold (build (MINUS_EXPR, TREE_TYPE (t),
1016 TREE_OPERAND (t, 1),
1017 TREE_OPERAND (t, 0))));
1021 if (TREE_UNSIGNED (TREE_TYPE (t)))
1027 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
1029 tem = TREE_OPERAND (t, 1);
1030 if (negate_expr_p (tem))
1031 return fold_convert (type,
1032 fold (build (TREE_CODE (t), TREE_TYPE (t),
1033 TREE_OPERAND (t, 0),
1034 negate_expr (tem))));
1035 tem = TREE_OPERAND (t, 0);
1036 if (negate_expr_p (tem))
1037 return fold_convert (type,
1038 fold (build (TREE_CODE (t), TREE_TYPE (t),
1040 TREE_OPERAND (t, 1))));
1045 /* Convert -((double)float) into (double)(-float). */
1046 if (TREE_CODE (type) == REAL_TYPE)
1048 tem = strip_float_extensions (t);
1049 if (tem != t && negate_expr_p (tem))
1050 return fold_convert (type, negate_expr (tem));
1055 /* Negate -f(x) as f(-x). */
1056 if (negate_mathfn_p (builtin_mathfn_code (t))
1057 && negate_expr_p (TREE_VALUE (TREE_OPERAND (t, 1))))
1059 tree fndecl, arg, arglist;
1061 fndecl = get_callee_fndecl (t);
1062 arg = negate_expr (TREE_VALUE (TREE_OPERAND (t, 1)));
1063 arglist = build_tree_list (NULL_TREE, arg);
1064 return build_function_call_expr (fndecl, arglist);
1072 tem = fold (build1 (NEGATE_EXPR, TREE_TYPE (t), t));
1073 return fold_convert (type, tem);
1076 /* Split a tree IN into a constant, literal and variable parts that could be
1077 combined with CODE to make IN. "constant" means an expression with
1078 TREE_CONSTANT but that isn't an actual constant. CODE must be a
1079 commutative arithmetic operation. Store the constant part into *CONP,
1080 the literal in *LITP and return the variable part. If a part isn't
1081 present, set it to null. If the tree does not decompose in this way,
1082 return the entire tree as the variable part and the other parts as null.
1084 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
1085 case, we negate an operand that was subtracted. Except if it is a
1086 literal for which we use *MINUS_LITP instead.
1088 If NEGATE_P is true, we are negating all of IN, again except a literal
1089 for which we use *MINUS_LITP instead.
1091 If IN is itself a literal or constant, return it as appropriate.
1093 Note that we do not guarantee that any of the three values will be the
1094 same type as IN, but they will have the same signedness and mode. */
1097 split_tree (tree in, enum tree_code code, tree *conp, tree *litp,
1098 tree *minus_litp, int negate_p)
1106 /* Strip any conversions that don't change the machine mode or signedness. */
1107 STRIP_SIGN_NOPS (in);
1109 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST)
1111 else if (TREE_CODE (in) == code
1112 || (! FLOAT_TYPE_P (TREE_TYPE (in))
1113 /* We can associate addition and subtraction together (even
1114 though the C standard doesn't say so) for integers because
1115 the value is not affected. For reals, the value might be
1116 affected, so we can't. */
1117 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
1118 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
1120 tree op0 = TREE_OPERAND (in, 0);
1121 tree op1 = TREE_OPERAND (in, 1);
1122 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
1123 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
1125 /* First see if either of the operands is a literal, then a constant. */
1126 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
1127 *litp = op0, op0 = 0;
1128 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST)
1129 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
1131 if (op0 != 0 && TREE_CONSTANT (op0))
1132 *conp = op0, op0 = 0;
1133 else if (op1 != 0 && TREE_CONSTANT (op1))
1134 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
1136 /* If we haven't dealt with either operand, this is not a case we can
1137 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1138 if (op0 != 0 && op1 != 0)
1143 var = op1, neg_var_p = neg1_p;
1145 /* Now do any needed negations. */
1147 *minus_litp = *litp, *litp = 0;
1149 *conp = negate_expr (*conp);
1151 var = negate_expr (var);
1153 else if (TREE_CONSTANT (in))
1161 *minus_litp = *litp, *litp = 0;
1162 else if (*minus_litp)
1163 *litp = *minus_litp, *minus_litp = 0;
1164 *conp = negate_expr (*conp);
1165 var = negate_expr (var);
1171 /* Re-associate trees split by the above function. T1 and T2 are either
1172 expressions to associate or null. Return the new expression, if any. If
1173 we build an operation, do it in TYPE and with CODE. */
1176 associate_trees (tree t1, tree t2, enum tree_code code, tree type)
1183 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1184 try to fold this since we will have infinite recursion. But do
1185 deal with any NEGATE_EXPRs. */
1186 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
1187 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1189 if (code == PLUS_EXPR)
1191 if (TREE_CODE (t1) == NEGATE_EXPR)
1192 return build (MINUS_EXPR, type, fold_convert (type, t2),
1193 fold_convert (type, TREE_OPERAND (t1, 0)));
1194 else if (TREE_CODE (t2) == NEGATE_EXPR)
1195 return build (MINUS_EXPR, type, fold_convert (type, t1),
1196 fold_convert (type, TREE_OPERAND (t2, 0)));
1198 return build (code, type, fold_convert (type, t1),
1199 fold_convert (type, t2));
1202 return fold (build (code, type, fold_convert (type, t1),
1203 fold_convert (type, t2)));
1206 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1207 to produce a new constant.
1209 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1212 int_const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1214 unsigned HOST_WIDE_INT int1l, int2l;
1215 HOST_WIDE_INT int1h, int2h;
1216 unsigned HOST_WIDE_INT low;
1218 unsigned HOST_WIDE_INT garbagel;
1219 HOST_WIDE_INT garbageh;
1221 tree type = TREE_TYPE (arg1);
1222 int uns = TREE_UNSIGNED (type);
1224 = (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type));
1226 int no_overflow = 0;
1228 int1l = TREE_INT_CST_LOW (arg1);
1229 int1h = TREE_INT_CST_HIGH (arg1);
1230 int2l = TREE_INT_CST_LOW (arg2);
1231 int2h = TREE_INT_CST_HIGH (arg2);
1236 low = int1l | int2l, hi = int1h | int2h;
1240 low = int1l ^ int2l, hi = int1h ^ int2h;
1244 low = int1l & int2l, hi = int1h & int2h;
1250 /* It's unclear from the C standard whether shifts can overflow.
1251 The following code ignores overflow; perhaps a C standard
1252 interpretation ruling is needed. */
1253 lshift_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1261 lrotate_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1266 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1270 neg_double (int2l, int2h, &low, &hi);
1271 add_double (int1l, int1h, low, hi, &low, &hi);
1272 overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
1276 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1279 case TRUNC_DIV_EXPR:
1280 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1281 case EXACT_DIV_EXPR:
1282 /* This is a shortcut for a common special case. */
1283 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1284 && ! TREE_CONSTANT_OVERFLOW (arg1)
1285 && ! TREE_CONSTANT_OVERFLOW (arg2)
1286 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1288 if (code == CEIL_DIV_EXPR)
1291 low = int1l / int2l, hi = 0;
1295 /* ... fall through ... */
1297 case ROUND_DIV_EXPR:
1298 if (int2h == 0 && int2l == 1)
1300 low = int1l, hi = int1h;
1303 if (int1l == int2l && int1h == int2h
1304 && ! (int1l == 0 && int1h == 0))
1309 overflow = div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
1310 &low, &hi, &garbagel, &garbageh);
1313 case TRUNC_MOD_EXPR:
1314 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1315 /* This is a shortcut for a common special case. */
1316 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1317 && ! TREE_CONSTANT_OVERFLOW (arg1)
1318 && ! TREE_CONSTANT_OVERFLOW (arg2)
1319 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1321 if (code == CEIL_MOD_EXPR)
1323 low = int1l % int2l, hi = 0;
1327 /* ... fall through ... */
1329 case ROUND_MOD_EXPR:
1330 overflow = div_and_round_double (code, uns,
1331 int1l, int1h, int2l, int2h,
1332 &garbagel, &garbageh, &low, &hi);
1338 low = (((unsigned HOST_WIDE_INT) int1h
1339 < (unsigned HOST_WIDE_INT) int2h)
1340 || (((unsigned HOST_WIDE_INT) int1h
1341 == (unsigned HOST_WIDE_INT) int2h)
1344 low = (int1h < int2h
1345 || (int1h == int2h && int1l < int2l));
1347 if (low == (code == MIN_EXPR))
1348 low = int1l, hi = int1h;
1350 low = int2l, hi = int2h;
1357 /* If this is for a sizetype, can be represented as one (signed)
1358 HOST_WIDE_INT word, and doesn't overflow, use size_int since it caches
1361 && ((hi == 0 && (HOST_WIDE_INT) low >= 0)
1362 || (hi == -1 && (HOST_WIDE_INT) low < 0))
1363 && overflow == 0 && ! TREE_OVERFLOW (arg1) && ! TREE_OVERFLOW (arg2))
1364 return size_int_type_wide (low, type);
1367 t = build_int_2 (low, hi);
1368 TREE_TYPE (t) = TREE_TYPE (arg1);
1373 ? (!uns || is_sizetype) && overflow
1374 : (force_fit_type (t, (!uns || is_sizetype) && overflow)
1376 | TREE_OVERFLOW (arg1)
1377 | TREE_OVERFLOW (arg2));
1379 /* If we're doing a size calculation, unsigned arithmetic does overflow.
1380 So check if force_fit_type truncated the value. */
1382 && ! TREE_OVERFLOW (t)
1383 && (TREE_INT_CST_HIGH (t) != hi
1384 || TREE_INT_CST_LOW (t) != low))
1385 TREE_OVERFLOW (t) = 1;
1387 TREE_CONSTANT_OVERFLOW (t) = (TREE_OVERFLOW (t)
1388 | TREE_CONSTANT_OVERFLOW (arg1)
1389 | TREE_CONSTANT_OVERFLOW (arg2));
1393 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1394 constant. We assume ARG1 and ARG2 have the same data type, or at least
1395 are the same kind of constant and the same machine mode.
1397 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1400 const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1405 if (TREE_CODE (arg1) == INTEGER_CST)
1406 return int_const_binop (code, arg1, arg2, notrunc);
1408 if (TREE_CODE (arg1) == REAL_CST)
1410 enum machine_mode mode;
1413 REAL_VALUE_TYPE value;
1416 d1 = TREE_REAL_CST (arg1);
1417 d2 = TREE_REAL_CST (arg2);
1419 type = TREE_TYPE (arg1);
1420 mode = TYPE_MODE (type);
1422 /* Don't perform operation if we honor signaling NaNs and
1423 either operand is a NaN. */
1424 if (HONOR_SNANS (mode)
1425 && (REAL_VALUE_ISNAN (d1) || REAL_VALUE_ISNAN (d2)))
1428 /* Don't perform operation if it would raise a division
1429 by zero exception. */
1430 if (code == RDIV_EXPR
1431 && REAL_VALUES_EQUAL (d2, dconst0)
1432 && (flag_trapping_math || ! MODE_HAS_INFINITIES (mode)))
1435 /* If either operand is a NaN, just return it. Otherwise, set up
1436 for floating-point trap; we return an overflow. */
1437 if (REAL_VALUE_ISNAN (d1))
1439 else if (REAL_VALUE_ISNAN (d2))
1442 REAL_ARITHMETIC (value, code, d1, d2);
1444 t = build_real (type, real_value_truncate (mode, value));
1447 = (force_fit_type (t, 0)
1448 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
1449 TREE_CONSTANT_OVERFLOW (t)
1451 | TREE_CONSTANT_OVERFLOW (arg1)
1452 | TREE_CONSTANT_OVERFLOW (arg2);
1455 if (TREE_CODE (arg1) == COMPLEX_CST)
1457 tree type = TREE_TYPE (arg1);
1458 tree r1 = TREE_REALPART (arg1);
1459 tree i1 = TREE_IMAGPART (arg1);
1460 tree r2 = TREE_REALPART (arg2);
1461 tree i2 = TREE_IMAGPART (arg2);
1467 t = build_complex (type,
1468 const_binop (PLUS_EXPR, r1, r2, notrunc),
1469 const_binop (PLUS_EXPR, i1, i2, notrunc));
1473 t = build_complex (type,
1474 const_binop (MINUS_EXPR, r1, r2, notrunc),
1475 const_binop (MINUS_EXPR, i1, i2, notrunc));
1479 t = build_complex (type,
1480 const_binop (MINUS_EXPR,
1481 const_binop (MULT_EXPR,
1483 const_binop (MULT_EXPR,
1486 const_binop (PLUS_EXPR,
1487 const_binop (MULT_EXPR,
1489 const_binop (MULT_EXPR,
1497 = const_binop (PLUS_EXPR,
1498 const_binop (MULT_EXPR, r2, r2, notrunc),
1499 const_binop (MULT_EXPR, i2, i2, notrunc),
1502 t = build_complex (type,
1504 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1505 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1506 const_binop (PLUS_EXPR,
1507 const_binop (MULT_EXPR, r1, r2,
1509 const_binop (MULT_EXPR, i1, i2,
1512 magsquared, notrunc),
1514 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1515 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1516 const_binop (MINUS_EXPR,
1517 const_binop (MULT_EXPR, i1, r2,
1519 const_binop (MULT_EXPR, r1, i2,
1522 magsquared, notrunc));
1534 /* These are the hash table functions for the hash table of INTEGER_CST
1535 nodes of a sizetype. */
1537 /* Return the hash code code X, an INTEGER_CST. */
1540 size_htab_hash (const void *x)
1544 return (TREE_INT_CST_HIGH (t) ^ TREE_INT_CST_LOW (t)
1545 ^ htab_hash_pointer (TREE_TYPE (t))
1546 ^ (TREE_OVERFLOW (t) << 20));
1549 /* Return nonzero if the value represented by *X (an INTEGER_CST tree node)
1550 is the same as that given by *Y, which is the same. */
1553 size_htab_eq (const void *x, const void *y)
1558 return (TREE_INT_CST_HIGH (xt) == TREE_INT_CST_HIGH (yt)
1559 && TREE_INT_CST_LOW (xt) == TREE_INT_CST_LOW (yt)
1560 && TREE_TYPE (xt) == TREE_TYPE (yt)
1561 && TREE_OVERFLOW (xt) == TREE_OVERFLOW (yt));
1564 /* Return an INTEGER_CST with value whose low-order HOST_BITS_PER_WIDE_INT
1565 bits are given by NUMBER and of the sizetype represented by KIND. */
1568 size_int_wide (HOST_WIDE_INT number, enum size_type_kind kind)
1570 return size_int_type_wide (number, sizetype_tab[(int) kind]);
1573 /* Likewise, but the desired type is specified explicitly. */
1575 static GTY (()) tree new_const;
1576 static GTY ((if_marked ("ggc_marked_p"), param_is (union tree_node)))
1580 size_int_type_wide (HOST_WIDE_INT number, tree type)
1586 size_htab = htab_create_ggc (1024, size_htab_hash, size_htab_eq, NULL);
1587 new_const = make_node (INTEGER_CST);
1590 /* Adjust NEW_CONST to be the constant we want. If it's already in the
1591 hash table, we return the value from the hash table. Otherwise, we
1592 place that in the hash table and make a new node for the next time. */
1593 TREE_INT_CST_LOW (new_const) = number;
1594 TREE_INT_CST_HIGH (new_const) = number < 0 ? -1 : 0;
1595 TREE_TYPE (new_const) = type;
1596 TREE_OVERFLOW (new_const) = TREE_CONSTANT_OVERFLOW (new_const)
1597 = force_fit_type (new_const, 0);
1599 slot = htab_find_slot (size_htab, new_const, INSERT);
1605 new_const = make_node (INTEGER_CST);
1609 return (tree) *slot;
1612 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1613 is a tree code. The type of the result is taken from the operands.
1614 Both must be the same type integer type and it must be a size type.
1615 If the operands are constant, so is the result. */
1618 size_binop (enum tree_code code, tree arg0, tree arg1)
1620 tree type = TREE_TYPE (arg0);
1622 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1623 || type != TREE_TYPE (arg1))
1626 /* Handle the special case of two integer constants faster. */
1627 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1629 /* And some specific cases even faster than that. */
1630 if (code == PLUS_EXPR && integer_zerop (arg0))
1632 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1633 && integer_zerop (arg1))
1635 else if (code == MULT_EXPR && integer_onep (arg0))
1638 /* Handle general case of two integer constants. */
1639 return int_const_binop (code, arg0, arg1, 0);
1642 if (arg0 == error_mark_node || arg1 == error_mark_node)
1643 return error_mark_node;
1645 return fold (build (code, type, arg0, arg1));
1648 /* Given two values, either both of sizetype or both of bitsizetype,
1649 compute the difference between the two values. Return the value
1650 in signed type corresponding to the type of the operands. */
1653 size_diffop (tree arg0, tree arg1)
1655 tree type = TREE_TYPE (arg0);
1658 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1659 || type != TREE_TYPE (arg1))
1662 /* If the type is already signed, just do the simple thing. */
1663 if (! TREE_UNSIGNED (type))
1664 return size_binop (MINUS_EXPR, arg0, arg1);
1666 ctype = (type == bitsizetype || type == ubitsizetype
1667 ? sbitsizetype : ssizetype);
1669 /* If either operand is not a constant, do the conversions to the signed
1670 type and subtract. The hardware will do the right thing with any
1671 overflow in the subtraction. */
1672 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
1673 return size_binop (MINUS_EXPR, fold_convert (ctype, arg0),
1674 fold_convert (ctype, arg1));
1676 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
1677 Otherwise, subtract the other way, convert to CTYPE (we know that can't
1678 overflow) and negate (which can't either). Special-case a result
1679 of zero while we're here. */
1680 if (tree_int_cst_equal (arg0, arg1))
1681 return fold_convert (ctype, integer_zero_node);
1682 else if (tree_int_cst_lt (arg1, arg0))
1683 return fold_convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
1685 return size_binop (MINUS_EXPR, fold_convert (ctype, integer_zero_node),
1686 fold_convert (ctype, size_binop (MINUS_EXPR,
1691 /* Attempt to fold type conversion operation CODE of expression ARG1 to
1692 type TYPE. If no simplification can be done return NULL_TREE. */
1695 fold_convert_const (enum tree_code code, tree type, tree arg1)
1700 if (TREE_TYPE (arg1) == type)
1703 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
1705 if (TREE_CODE (arg1) == INTEGER_CST)
1707 /* If we would build a constant wider than GCC supports,
1708 leave the conversion unfolded. */
1709 if (TYPE_PRECISION (type) > 2 * HOST_BITS_PER_WIDE_INT)
1712 /* If we are trying to make a sizetype for a small integer, use
1713 size_int to pick up cached types to reduce duplicate nodes. */
1714 if (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type)
1715 && !TREE_CONSTANT_OVERFLOW (arg1)
1716 && compare_tree_int (arg1, 10000) < 0)
1717 return size_int_type_wide (TREE_INT_CST_LOW (arg1), type);
1719 /* Given an integer constant, make new constant with new type,
1720 appropriately sign-extended or truncated. */
1721 t = build_int_2 (TREE_INT_CST_LOW (arg1),
1722 TREE_INT_CST_HIGH (arg1));
1723 TREE_TYPE (t) = type;
1724 /* Indicate an overflow if (1) ARG1 already overflowed,
1725 or (2) force_fit_type indicates an overflow.
1726 Tell force_fit_type that an overflow has already occurred
1727 if ARG1 is a too-large unsigned value and T is signed.
1728 But don't indicate an overflow if converting a pointer. */
1730 = ((force_fit_type (t,
1731 (TREE_INT_CST_HIGH (arg1) < 0
1732 && (TREE_UNSIGNED (type)
1733 < TREE_UNSIGNED (TREE_TYPE (arg1)))))
1734 && ! POINTER_TYPE_P (TREE_TYPE (arg1)))
1735 || TREE_OVERFLOW (arg1));
1736 TREE_CONSTANT_OVERFLOW (t)
1737 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1740 else if (TREE_CODE (arg1) == REAL_CST)
1742 /* The following code implements the floating point to integer
1743 conversion rules required by the Java Language Specification,
1744 that IEEE NaNs are mapped to zero and values that overflow
1745 the target precision saturate, i.e. values greater than
1746 INT_MAX are mapped to INT_MAX, and values less than INT_MIN
1747 are mapped to INT_MIN. These semantics are allowed by the
1748 C and C++ standards that simply state that the behavior of
1749 FP-to-integer conversion is unspecified upon overflow. */
1751 HOST_WIDE_INT high, low;
1754 REAL_VALUE_TYPE x = TREE_REAL_CST (arg1);
1758 case FIX_TRUNC_EXPR:
1759 real_trunc (&r, VOIDmode, &x);
1763 real_ceil (&r, VOIDmode, &x);
1766 case FIX_FLOOR_EXPR:
1767 real_floor (&r, VOIDmode, &x);
1774 /* If R is NaN, return zero and show we have an overflow. */
1775 if (REAL_VALUE_ISNAN (r))
1782 /* See if R is less than the lower bound or greater than the
1787 tree lt = TYPE_MIN_VALUE (type);
1788 REAL_VALUE_TYPE l = real_value_from_int_cst (NULL_TREE, lt);
1789 if (REAL_VALUES_LESS (r, l))
1792 high = TREE_INT_CST_HIGH (lt);
1793 low = TREE_INT_CST_LOW (lt);
1799 tree ut = TYPE_MAX_VALUE (type);
1802 REAL_VALUE_TYPE u = real_value_from_int_cst (NULL_TREE, ut);
1803 if (REAL_VALUES_LESS (u, r))
1806 high = TREE_INT_CST_HIGH (ut);
1807 low = TREE_INT_CST_LOW (ut);
1813 REAL_VALUE_TO_INT (&low, &high, r);
1815 t = build_int_2 (low, high);
1816 TREE_TYPE (t) = type;
1818 = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
1819 TREE_CONSTANT_OVERFLOW (t)
1820 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1824 else if (TREE_CODE (type) == REAL_TYPE)
1826 if (TREE_CODE (arg1) == INTEGER_CST)
1827 return build_real_from_int_cst (type, arg1);
1828 if (TREE_CODE (arg1) == REAL_CST)
1830 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
1832 /* We make a copy of ARG1 so that we don't modify an
1833 existing constant tree. */
1834 t = copy_node (arg1);
1835 TREE_TYPE (t) = type;
1839 t = build_real (type,
1840 real_value_truncate (TYPE_MODE (type),
1841 TREE_REAL_CST (arg1)));
1844 = TREE_OVERFLOW (arg1) | force_fit_type (t, 0);
1845 TREE_CONSTANT_OVERFLOW (t)
1846 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1853 /* Convert expression ARG to type TYPE. Used by the middle-end for
1854 simple conversions in preference to calling the front-end's convert. */
1857 fold_convert (tree type, tree arg)
1859 tree orig = TREE_TYPE (arg);
1865 if (TREE_CODE (arg) == ERROR_MARK
1866 || TREE_CODE (type) == ERROR_MARK
1867 || TREE_CODE (orig) == ERROR_MARK)
1868 return error_mark_node;
1870 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig))
1871 return fold (build1 (NOP_EXPR, type, arg));
1873 if (INTEGRAL_TYPE_P (type) || POINTER_TYPE_P (type))
1875 if (TREE_CODE (arg) == INTEGER_CST)
1877 tem = fold_convert_const (NOP_EXPR, type, arg);
1878 if (tem != NULL_TREE)
1881 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig))
1882 return fold (build1 (NOP_EXPR, type, arg));
1883 if (TREE_CODE (orig) == COMPLEX_TYPE)
1885 tem = fold (build1 (REALPART_EXPR, TREE_TYPE (orig), arg));
1886 return fold_convert (type, tem);
1888 if (TREE_CODE (orig) == VECTOR_TYPE
1889 && GET_MODE_SIZE (TYPE_MODE (type))
1890 == GET_MODE_SIZE (TYPE_MODE (orig)))
1891 return fold (build1 (NOP_EXPR, type, arg));
1893 else if (TREE_CODE (type) == REAL_TYPE)
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 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig))
1909 return fold (build1 (FLOAT_EXPR, type, arg));
1910 if (TREE_CODE (orig) == REAL_TYPE)
1911 return fold (build1 (flag_float_store ? CONVERT_EXPR : NOP_EXPR,
1913 if (TREE_CODE (orig) == COMPLEX_TYPE)
1915 tem = fold (build1 (REALPART_EXPR, TREE_TYPE (orig), arg));
1916 return fold_convert (type, tem);
1919 else if (TREE_CODE (type) == COMPLEX_TYPE)
1921 if (INTEGRAL_TYPE_P (orig)
1922 || POINTER_TYPE_P (orig)
1923 || TREE_CODE (orig) == REAL_TYPE)
1924 return build (COMPLEX_EXPR, type,
1925 fold_convert (TREE_TYPE (type), arg),
1926 fold_convert (TREE_TYPE (type), integer_zero_node));
1927 if (TREE_CODE (orig) == COMPLEX_TYPE)
1931 if (TREE_CODE (arg) == COMPLEX_EXPR)
1933 rpart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 0));
1934 ipart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 1));
1935 return fold (build (COMPLEX_EXPR, type, rpart, ipart));
1938 arg = save_expr (arg);
1939 rpart = fold (build1 (REALPART_EXPR, TREE_TYPE (orig), arg));
1940 ipart = fold (build1 (IMAGPART_EXPR, TREE_TYPE (orig), arg));
1941 rpart = fold_convert (TREE_TYPE (type), rpart);
1942 ipart = fold_convert (TREE_TYPE (type), ipart);
1943 return fold (build (COMPLEX_EXPR, type, rpart, ipart));
1946 else if (TREE_CODE (type) == VECTOR_TYPE)
1948 if ((INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig))
1949 && GET_MODE_SIZE (TYPE_MODE (type))
1950 == GET_MODE_SIZE (TYPE_MODE (orig)))
1951 return fold (build1 (NOP_EXPR, type, arg));
1952 if (TREE_CODE (orig) == VECTOR_TYPE
1953 && GET_MODE_SIZE (TYPE_MODE (type))
1954 == GET_MODE_SIZE (TYPE_MODE (orig)))
1955 return fold (build1 (NOP_EXPR, type, arg));
1957 else if (VOID_TYPE_P (type))
1958 return fold (build1 (CONVERT_EXPR, type, arg));
1962 /* Return an expr equal to X but certainly not valid as an lvalue. */
1969 /* These things are certainly not lvalues. */
1970 if (TREE_CODE (x) == NON_LVALUE_EXPR
1971 || TREE_CODE (x) == INTEGER_CST
1972 || TREE_CODE (x) == REAL_CST
1973 || TREE_CODE (x) == STRING_CST
1974 || TREE_CODE (x) == ADDR_EXPR)
1977 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
1978 TREE_CONSTANT (result) = TREE_CONSTANT (x);
1982 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
1983 Zero means allow extended lvalues. */
1985 int pedantic_lvalues;
1987 /* When pedantic, return an expr equal to X but certainly not valid as a
1988 pedantic lvalue. Otherwise, return X. */
1991 pedantic_non_lvalue (tree x)
1993 if (pedantic_lvalues)
1994 return non_lvalue (x);
1999 /* Given a tree comparison code, return the code that is the logical inverse
2000 of the given code. It is not safe to do this for floating-point
2001 comparisons, except for NE_EXPR and EQ_EXPR. */
2003 static enum tree_code
2004 invert_tree_comparison (enum tree_code code)
2025 /* Similar, but return the comparison that results if the operands are
2026 swapped. This is safe for floating-point. */
2028 static enum tree_code
2029 swap_tree_comparison (enum tree_code code)
2050 /* Convert a comparison tree code from an enum tree_code representation
2051 into a compcode bit-based encoding. This function is the inverse of
2052 compcode_to_comparison. */
2055 comparison_to_compcode (enum tree_code code)
2076 /* Convert a compcode bit-based encoding of a comparison operator back
2077 to GCC's enum tree_code representation. This function is the
2078 inverse of comparison_to_compcode. */
2080 static enum tree_code
2081 compcode_to_comparison (int code)
2102 /* Return nonzero if CODE is a tree code that represents a truth value. */
2105 truth_value_p (enum tree_code code)
2107 return (TREE_CODE_CLASS (code) == '<'
2108 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2109 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2110 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
2113 /* Return nonzero if two operands (typically of the same tree node)
2114 are necessarily equal. If either argument has side-effects this
2115 function returns zero.
2117 If ONLY_CONST is nonzero, only return nonzero for constants.
2118 This function tests whether the operands are indistinguishable;
2119 it does not test whether they are equal using C's == operation.
2120 The distinction is important for IEEE floating point, because
2121 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2122 (2) two NaNs may be indistinguishable, but NaN!=NaN.
2124 If ONLY_CONST is zero, a VAR_DECL is considered equal to itself
2125 even though it may hold multiple values during a function.
2126 This is because a GCC tree node guarantees that nothing else is
2127 executed between the evaluation of its "operands" (which may often
2128 be evaluated in arbitrary order). Hence if the operands themselves
2129 don't side-effect, the VAR_DECLs, PARM_DECLs etc... must hold the
2130 same value in each operand/subexpression. Hence a zero value for
2131 ONLY_CONST assumes isochronic (or instantaneous) tree equivalence.
2132 If comparing arbitrary expression trees, such as from different
2133 statements, ONLY_CONST must usually be nonzero. */
2136 operand_equal_p (tree arg0, tree arg1, int only_const)
2140 /* If both types don't have the same signedness, then we can't consider
2141 them equal. We must check this before the STRIP_NOPS calls
2142 because they may change the signedness of the arguments. */
2143 if (TREE_UNSIGNED (TREE_TYPE (arg0)) != TREE_UNSIGNED (TREE_TYPE (arg1)))
2149 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2150 /* This is needed for conversions and for COMPONENT_REF.
2151 Might as well play it safe and always test this. */
2152 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
2153 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
2154 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
2157 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
2158 We don't care about side effects in that case because the SAVE_EXPR
2159 takes care of that for us. In all other cases, two expressions are
2160 equal if they have no side effects. If we have two identical
2161 expressions with side effects that should be treated the same due
2162 to the only side effects being identical SAVE_EXPR's, that will
2163 be detected in the recursive calls below. */
2164 if (arg0 == arg1 && ! only_const
2165 && (TREE_CODE (arg0) == SAVE_EXPR
2166 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
2169 /* Next handle constant cases, those for which we can return 1 even
2170 if ONLY_CONST is set. */
2171 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
2172 switch (TREE_CODE (arg0))
2175 return (! TREE_CONSTANT_OVERFLOW (arg0)
2176 && ! TREE_CONSTANT_OVERFLOW (arg1)
2177 && tree_int_cst_equal (arg0, arg1));
2180 return (! TREE_CONSTANT_OVERFLOW (arg0)
2181 && ! TREE_CONSTANT_OVERFLOW (arg1)
2182 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
2183 TREE_REAL_CST (arg1)));
2189 if (TREE_CONSTANT_OVERFLOW (arg0)
2190 || TREE_CONSTANT_OVERFLOW (arg1))
2193 v1 = TREE_VECTOR_CST_ELTS (arg0);
2194 v2 = TREE_VECTOR_CST_ELTS (arg1);
2197 if (!operand_equal_p (TREE_VALUE (v1), TREE_VALUE (v2),
2200 v1 = TREE_CHAIN (v1);
2201 v2 = TREE_CHAIN (v2);
2208 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
2210 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
2214 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
2215 && ! memcmp (TREE_STRING_POINTER (arg0),
2216 TREE_STRING_POINTER (arg1),
2217 TREE_STRING_LENGTH (arg0)));
2220 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
2229 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
2232 /* Two conversions are equal only if signedness and modes match. */
2233 if ((TREE_CODE (arg0) == NOP_EXPR || TREE_CODE (arg0) == CONVERT_EXPR)
2234 && (TREE_UNSIGNED (TREE_TYPE (arg0))
2235 != TREE_UNSIGNED (TREE_TYPE (arg1))))
2238 return operand_equal_p (TREE_OPERAND (arg0, 0),
2239 TREE_OPERAND (arg1, 0), 0);
2243 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0)
2244 && operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1),
2248 /* For commutative ops, allow the other order. */
2249 return (commutative_tree_code (TREE_CODE (arg0))
2250 && operand_equal_p (TREE_OPERAND (arg0, 0),
2251 TREE_OPERAND (arg1, 1), 0)
2252 && operand_equal_p (TREE_OPERAND (arg0, 1),
2253 TREE_OPERAND (arg1, 0), 0));
2256 /* If either of the pointer (or reference) expressions we are
2257 dereferencing contain a side effect, these cannot be equal. */
2258 if (TREE_SIDE_EFFECTS (arg0)
2259 || TREE_SIDE_EFFECTS (arg1))
2262 switch (TREE_CODE (arg0))
2265 return operand_equal_p (TREE_OPERAND (arg0, 0),
2266 TREE_OPERAND (arg1, 0), 0);
2270 case ARRAY_RANGE_REF:
2271 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2272 TREE_OPERAND (arg1, 0), 0)
2273 && operand_equal_p (TREE_OPERAND (arg0, 1),
2274 TREE_OPERAND (arg1, 1), 0));
2277 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2278 TREE_OPERAND (arg1, 0), 0)
2279 && operand_equal_p (TREE_OPERAND (arg0, 1),
2280 TREE_OPERAND (arg1, 1), 0)
2281 && operand_equal_p (TREE_OPERAND (arg0, 2),
2282 TREE_OPERAND (arg1, 2), 0));
2288 switch (TREE_CODE (arg0))
2291 case TRUTH_NOT_EXPR:
2292 return operand_equal_p (TREE_OPERAND (arg0, 0),
2293 TREE_OPERAND (arg1, 0), 0);
2296 return rtx_equal_p (RTL_EXPR_RTL (arg0), RTL_EXPR_RTL (arg1));
2299 /* If the CALL_EXPRs call different functions, then they
2300 clearly can not be equal. */
2301 if (! operand_equal_p (TREE_OPERAND (arg0, 0),
2302 TREE_OPERAND (arg1, 0), 0))
2305 /* Only consider const functions equivalent. */
2306 fndecl = get_callee_fndecl (arg0);
2307 if (fndecl == NULL_TREE
2308 || ! (flags_from_decl_or_type (fndecl) & ECF_CONST))
2311 /* Now see if all the arguments are the same. operand_equal_p
2312 does not handle TREE_LIST, so we walk the operands here
2313 feeding them to operand_equal_p. */
2314 arg0 = TREE_OPERAND (arg0, 1);
2315 arg1 = TREE_OPERAND (arg1, 1);
2316 while (arg0 && arg1)
2318 if (! operand_equal_p (TREE_VALUE (arg0), TREE_VALUE (arg1), 0))
2321 arg0 = TREE_CHAIN (arg0);
2322 arg1 = TREE_CHAIN (arg1);
2325 /* If we get here and both argument lists are exhausted
2326 then the CALL_EXPRs are equal. */
2327 return ! (arg0 || arg1);
2334 /* Consider __builtin_sqrt equal to sqrt. */
2335 return TREE_CODE (arg0) == FUNCTION_DECL
2336 && DECL_BUILT_IN (arg0) && DECL_BUILT_IN (arg1)
2337 && DECL_BUILT_IN_CLASS (arg0) == DECL_BUILT_IN_CLASS (arg1)
2338 && DECL_FUNCTION_CODE (arg0) == DECL_FUNCTION_CODE (arg1);
2345 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2346 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2348 When in doubt, return 0. */
2351 operand_equal_for_comparison_p (tree arg0, tree arg1, tree other)
2353 int unsignedp1, unsignedpo;
2354 tree primarg0, primarg1, primother;
2355 unsigned int correct_width;
2357 if (operand_equal_p (arg0, arg1, 0))
2360 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
2361 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
2364 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2365 and see if the inner values are the same. This removes any
2366 signedness comparison, which doesn't matter here. */
2367 primarg0 = arg0, primarg1 = arg1;
2368 STRIP_NOPS (primarg0);
2369 STRIP_NOPS (primarg1);
2370 if (operand_equal_p (primarg0, primarg1, 0))
2373 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2374 actual comparison operand, ARG0.
2376 First throw away any conversions to wider types
2377 already present in the operands. */
2379 primarg1 = get_narrower (arg1, &unsignedp1);
2380 primother = get_narrower (other, &unsignedpo);
2382 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
2383 if (unsignedp1 == unsignedpo
2384 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
2385 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
2387 tree type = TREE_TYPE (arg0);
2389 /* Make sure shorter operand is extended the right way
2390 to match the longer operand. */
2391 primarg1 = fold_convert ((*lang_hooks.types.signed_or_unsigned_type)
2392 (unsignedp1, TREE_TYPE (primarg1)), primarg1);
2394 if (operand_equal_p (arg0, fold_convert (type, primarg1), 0))
2401 /* See if ARG is an expression that is either a comparison or is performing
2402 arithmetic on comparisons. The comparisons must only be comparing
2403 two different values, which will be stored in *CVAL1 and *CVAL2; if
2404 they are nonzero it means that some operands have already been found.
2405 No variables may be used anywhere else in the expression except in the
2406 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2407 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2409 If this is true, return 1. Otherwise, return zero. */
2412 twoval_comparison_p (tree arg, tree *cval1, tree *cval2, int *save_p)
2414 enum tree_code code = TREE_CODE (arg);
2415 char class = TREE_CODE_CLASS (code);
2417 /* We can handle some of the 'e' cases here. */
2418 if (class == 'e' && code == TRUTH_NOT_EXPR)
2420 else if (class == 'e'
2421 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
2422 || code == COMPOUND_EXPR))
2425 else if (class == 'e' && code == SAVE_EXPR && SAVE_EXPR_RTL (arg) == 0
2426 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
2428 /* If we've already found a CVAL1 or CVAL2, this expression is
2429 two complex to handle. */
2430 if (*cval1 || *cval2)
2440 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
2443 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
2444 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2445 cval1, cval2, save_p));
2451 if (code == COND_EXPR)
2452 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
2453 cval1, cval2, save_p)
2454 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2455 cval1, cval2, save_p)
2456 && twoval_comparison_p (TREE_OPERAND (arg, 2),
2457 cval1, cval2, save_p));
2461 /* First see if we can handle the first operand, then the second. For
2462 the second operand, we know *CVAL1 can't be zero. It must be that
2463 one side of the comparison is each of the values; test for the
2464 case where this isn't true by failing if the two operands
2467 if (operand_equal_p (TREE_OPERAND (arg, 0),
2468 TREE_OPERAND (arg, 1), 0))
2472 *cval1 = TREE_OPERAND (arg, 0);
2473 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
2475 else if (*cval2 == 0)
2476 *cval2 = TREE_OPERAND (arg, 0);
2477 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
2482 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
2484 else if (*cval2 == 0)
2485 *cval2 = TREE_OPERAND (arg, 1);
2486 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
2498 /* ARG is a tree that is known to contain just arithmetic operations and
2499 comparisons. Evaluate the operations in the tree substituting NEW0 for
2500 any occurrence of OLD0 as an operand of a comparison and likewise for
2504 eval_subst (tree arg, tree old0, tree new0, tree old1, tree new1)
2506 tree type = TREE_TYPE (arg);
2507 enum tree_code code = TREE_CODE (arg);
2508 char class = TREE_CODE_CLASS (code);
2510 /* We can handle some of the 'e' cases here. */
2511 if (class == 'e' && code == TRUTH_NOT_EXPR)
2513 else if (class == 'e'
2514 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2520 return fold (build1 (code, type,
2521 eval_subst (TREE_OPERAND (arg, 0),
2522 old0, new0, old1, new1)));
2525 return fold (build (code, type,
2526 eval_subst (TREE_OPERAND (arg, 0),
2527 old0, new0, old1, new1),
2528 eval_subst (TREE_OPERAND (arg, 1),
2529 old0, new0, old1, new1)));
2535 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
2538 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
2541 return fold (build (code, type,
2542 eval_subst (TREE_OPERAND (arg, 0),
2543 old0, new0, old1, new1),
2544 eval_subst (TREE_OPERAND (arg, 1),
2545 old0, new0, old1, new1),
2546 eval_subst (TREE_OPERAND (arg, 2),
2547 old0, new0, old1, new1)));
2551 /* Fall through - ??? */
2555 tree arg0 = TREE_OPERAND (arg, 0);
2556 tree arg1 = TREE_OPERAND (arg, 1);
2558 /* We need to check both for exact equality and tree equality. The
2559 former will be true if the operand has a side-effect. In that
2560 case, we know the operand occurred exactly once. */
2562 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
2564 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
2567 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
2569 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
2572 return fold (build (code, type, arg0, arg1));
2580 /* Return a tree for the case when the result of an expression is RESULT
2581 converted to TYPE and OMITTED was previously an operand of the expression
2582 but is now not needed (e.g., we folded OMITTED * 0).
2584 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2585 the conversion of RESULT to TYPE. */
2588 omit_one_operand (tree type, tree result, tree omitted)
2590 tree t = fold_convert (type, result);
2592 if (TREE_SIDE_EFFECTS (omitted))
2593 return build (COMPOUND_EXPR, type, omitted, t);
2595 return non_lvalue (t);
2598 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2601 pedantic_omit_one_operand (tree type, tree result, tree omitted)
2603 tree t = fold_convert (type, result);
2605 if (TREE_SIDE_EFFECTS (omitted))
2606 return build (COMPOUND_EXPR, type, omitted, t);
2608 return pedantic_non_lvalue (t);
2611 /* Return a simplified tree node for the truth-negation of ARG. This
2612 never alters ARG itself. We assume that ARG is an operation that
2613 returns a truth value (0 or 1). */
2616 invert_truthvalue (tree arg)
2618 tree type = TREE_TYPE (arg);
2619 enum tree_code code = TREE_CODE (arg);
2621 if (code == ERROR_MARK)
2624 /* If this is a comparison, we can simply invert it, except for
2625 floating-point non-equality comparisons, in which case we just
2626 enclose a TRUTH_NOT_EXPR around what we have. */
2628 if (TREE_CODE_CLASS (code) == '<')
2630 if (FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg, 0)))
2631 && !flag_unsafe_math_optimizations
2634 return build1 (TRUTH_NOT_EXPR, type, arg);
2635 else if (code == UNORDERED_EXPR
2636 || code == ORDERED_EXPR
2637 || code == UNEQ_EXPR
2638 || code == UNLT_EXPR
2639 || code == UNLE_EXPR
2640 || code == UNGT_EXPR
2641 || code == UNGE_EXPR)
2642 return build1 (TRUTH_NOT_EXPR, type, arg);
2644 return build (invert_tree_comparison (code), type,
2645 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
2651 return fold_convert (type, build_int_2 (integer_zerop (arg), 0));
2653 case TRUTH_AND_EXPR:
2654 return build (TRUTH_OR_EXPR, type,
2655 invert_truthvalue (TREE_OPERAND (arg, 0)),
2656 invert_truthvalue (TREE_OPERAND (arg, 1)));
2659 return build (TRUTH_AND_EXPR, type,
2660 invert_truthvalue (TREE_OPERAND (arg, 0)),
2661 invert_truthvalue (TREE_OPERAND (arg, 1)));
2663 case TRUTH_XOR_EXPR:
2664 /* Here we can invert either operand. We invert the first operand
2665 unless the second operand is a TRUTH_NOT_EXPR in which case our
2666 result is the XOR of the first operand with the inside of the
2667 negation of the second operand. */
2669 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
2670 return build (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
2671 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
2673 return build (TRUTH_XOR_EXPR, type,
2674 invert_truthvalue (TREE_OPERAND (arg, 0)),
2675 TREE_OPERAND (arg, 1));
2677 case TRUTH_ANDIF_EXPR:
2678 return build (TRUTH_ORIF_EXPR, type,
2679 invert_truthvalue (TREE_OPERAND (arg, 0)),
2680 invert_truthvalue (TREE_OPERAND (arg, 1)));
2682 case TRUTH_ORIF_EXPR:
2683 return build (TRUTH_ANDIF_EXPR, type,
2684 invert_truthvalue (TREE_OPERAND (arg, 0)),
2685 invert_truthvalue (TREE_OPERAND (arg, 1)));
2687 case TRUTH_NOT_EXPR:
2688 return TREE_OPERAND (arg, 0);
2691 return build (COND_EXPR, type, TREE_OPERAND (arg, 0),
2692 invert_truthvalue (TREE_OPERAND (arg, 1)),
2693 invert_truthvalue (TREE_OPERAND (arg, 2)));
2696 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
2697 invert_truthvalue (TREE_OPERAND (arg, 1)));
2699 case WITH_RECORD_EXPR:
2700 return build (WITH_RECORD_EXPR, type,
2701 invert_truthvalue (TREE_OPERAND (arg, 0)),
2702 TREE_OPERAND (arg, 1));
2704 case NON_LVALUE_EXPR:
2705 return invert_truthvalue (TREE_OPERAND (arg, 0));
2710 return build1 (TREE_CODE (arg), type,
2711 invert_truthvalue (TREE_OPERAND (arg, 0)));
2714 if (!integer_onep (TREE_OPERAND (arg, 1)))
2716 return build (EQ_EXPR, type, arg,
2717 fold_convert (type, integer_zero_node));
2720 return build1 (TRUTH_NOT_EXPR, type, arg);
2722 case CLEANUP_POINT_EXPR:
2723 return build1 (CLEANUP_POINT_EXPR, type,
2724 invert_truthvalue (TREE_OPERAND (arg, 0)));
2729 if (TREE_CODE (TREE_TYPE (arg)) != BOOLEAN_TYPE)
2731 return build1 (TRUTH_NOT_EXPR, type, arg);
2734 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
2735 operands are another bit-wise operation with a common input. If so,
2736 distribute the bit operations to save an operation and possibly two if
2737 constants are involved. For example, convert
2738 (A | B) & (A | C) into A | (B & C)
2739 Further simplification will occur if B and C are constants.
2741 If this optimization cannot be done, 0 will be returned. */
2744 distribute_bit_expr (enum tree_code code, tree type, tree arg0, tree arg1)
2749 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2750 || TREE_CODE (arg0) == code
2751 || (TREE_CODE (arg0) != BIT_AND_EXPR
2752 && TREE_CODE (arg0) != BIT_IOR_EXPR))
2755 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
2757 common = TREE_OPERAND (arg0, 0);
2758 left = TREE_OPERAND (arg0, 1);
2759 right = TREE_OPERAND (arg1, 1);
2761 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
2763 common = TREE_OPERAND (arg0, 0);
2764 left = TREE_OPERAND (arg0, 1);
2765 right = TREE_OPERAND (arg1, 0);
2767 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
2769 common = TREE_OPERAND (arg0, 1);
2770 left = TREE_OPERAND (arg0, 0);
2771 right = TREE_OPERAND (arg1, 1);
2773 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
2775 common = TREE_OPERAND (arg0, 1);
2776 left = TREE_OPERAND (arg0, 0);
2777 right = TREE_OPERAND (arg1, 0);
2782 return fold (build (TREE_CODE (arg0), type, common,
2783 fold (build (code, type, left, right))));
2786 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
2787 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
2790 make_bit_field_ref (tree inner, tree type, int bitsize, int bitpos,
2793 tree result = build (BIT_FIELD_REF, type, inner,
2794 size_int (bitsize), bitsize_int (bitpos));
2796 TREE_UNSIGNED (result) = unsignedp;
2801 /* Optimize a bit-field compare.
2803 There are two cases: First is a compare against a constant and the
2804 second is a comparison of two items where the fields are at the same
2805 bit position relative to the start of a chunk (byte, halfword, word)
2806 large enough to contain it. In these cases we can avoid the shift
2807 implicit in bitfield extractions.
2809 For constants, we emit a compare of the shifted constant with the
2810 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
2811 compared. For two fields at the same position, we do the ANDs with the
2812 similar mask and compare the result of the ANDs.
2814 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
2815 COMPARE_TYPE is the type of the comparison, and LHS and RHS
2816 are the left and right operands of the comparison, respectively.
2818 If the optimization described above can be done, we return the resulting
2819 tree. Otherwise we return zero. */
2822 optimize_bit_field_compare (enum tree_code code, tree compare_type,
2825 HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
2826 tree type = TREE_TYPE (lhs);
2827 tree signed_type, unsigned_type;
2828 int const_p = TREE_CODE (rhs) == INTEGER_CST;
2829 enum machine_mode lmode, rmode, nmode;
2830 int lunsignedp, runsignedp;
2831 int lvolatilep = 0, rvolatilep = 0;
2832 tree linner, rinner = NULL_TREE;
2836 /* Get all the information about the extractions being done. If the bit size
2837 if the same as the size of the underlying object, we aren't doing an
2838 extraction at all and so can do nothing. We also don't want to
2839 do anything if the inner expression is a PLACEHOLDER_EXPR since we
2840 then will no longer be able to replace it. */
2841 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
2842 &lunsignedp, &lvolatilep);
2843 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
2844 || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
2849 /* If this is not a constant, we can only do something if bit positions,
2850 sizes, and signedness are the same. */
2851 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
2852 &runsignedp, &rvolatilep);
2854 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
2855 || lunsignedp != runsignedp || offset != 0
2856 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
2860 /* See if we can find a mode to refer to this field. We should be able to,
2861 but fail if we can't. */
2862 nmode = get_best_mode (lbitsize, lbitpos,
2863 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
2864 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
2865 TYPE_ALIGN (TREE_TYPE (rinner))),
2866 word_mode, lvolatilep || rvolatilep);
2867 if (nmode == VOIDmode)
2870 /* Set signed and unsigned types of the precision of this mode for the
2872 signed_type = (*lang_hooks.types.type_for_mode) (nmode, 0);
2873 unsigned_type = (*lang_hooks.types.type_for_mode) (nmode, 1);
2875 /* Compute the bit position and size for the new reference and our offset
2876 within it. If the new reference is the same size as the original, we
2877 won't optimize anything, so return zero. */
2878 nbitsize = GET_MODE_BITSIZE (nmode);
2879 nbitpos = lbitpos & ~ (nbitsize - 1);
2881 if (nbitsize == lbitsize)
2884 if (BYTES_BIG_ENDIAN)
2885 lbitpos = nbitsize - lbitsize - lbitpos;
2887 /* Make the mask to be used against the extracted field. */
2888 mask = build_int_2 (~0, ~0);
2889 TREE_TYPE (mask) = unsigned_type;
2890 force_fit_type (mask, 0);
2891 mask = fold_convert (unsigned_type, mask);
2892 mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
2893 mask = const_binop (RSHIFT_EXPR, mask,
2894 size_int (nbitsize - lbitsize - lbitpos), 0);
2897 /* If not comparing with constant, just rework the comparison
2899 return build (code, compare_type,
2900 build (BIT_AND_EXPR, unsigned_type,
2901 make_bit_field_ref (linner, unsigned_type,
2902 nbitsize, nbitpos, 1),
2904 build (BIT_AND_EXPR, unsigned_type,
2905 make_bit_field_ref (rinner, unsigned_type,
2906 nbitsize, nbitpos, 1),
2909 /* Otherwise, we are handling the constant case. See if the constant is too
2910 big for the field. Warn and return a tree of for 0 (false) if so. We do
2911 this not only for its own sake, but to avoid having to test for this
2912 error case below. If we didn't, we might generate wrong code.
2914 For unsigned fields, the constant shifted right by the field length should
2915 be all zero. For signed fields, the high-order bits should agree with
2920 if (! integer_zerop (const_binop (RSHIFT_EXPR,
2921 fold_convert (unsigned_type, rhs),
2922 size_int (lbitsize), 0)))
2924 warning ("comparison is always %d due to width of bit-field",
2926 return fold_convert (compare_type,
2928 ? integer_one_node : integer_zero_node));
2933 tree tem = const_binop (RSHIFT_EXPR, fold_convert (signed_type, rhs),
2934 size_int (lbitsize - 1), 0);
2935 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
2937 warning ("comparison is always %d due to width of bit-field",
2939 return fold_convert (compare_type,
2941 ? integer_one_node : integer_zero_node));
2945 /* Single-bit compares should always be against zero. */
2946 if (lbitsize == 1 && ! integer_zerop (rhs))
2948 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
2949 rhs = fold_convert (type, integer_zero_node);
2952 /* Make a new bitfield reference, shift the constant over the
2953 appropriate number of bits and mask it with the computed mask
2954 (in case this was a signed field). If we changed it, make a new one. */
2955 lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1);
2958 TREE_SIDE_EFFECTS (lhs) = 1;
2959 TREE_THIS_VOLATILE (lhs) = 1;
2962 rhs = fold (const_binop (BIT_AND_EXPR,
2963 const_binop (LSHIFT_EXPR,
2964 fold_convert (unsigned_type, rhs),
2965 size_int (lbitpos), 0),
2968 return build (code, compare_type,
2969 build (BIT_AND_EXPR, unsigned_type, lhs, mask),
2973 /* Subroutine for fold_truthop: decode a field reference.
2975 If EXP is a comparison reference, we return the innermost reference.
2977 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
2978 set to the starting bit number.
2980 If the innermost field can be completely contained in a mode-sized
2981 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
2983 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
2984 otherwise it is not changed.
2986 *PUNSIGNEDP is set to the signedness of the field.
2988 *PMASK is set to the mask used. This is either contained in a
2989 BIT_AND_EXPR or derived from the width of the field.
2991 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
2993 Return 0 if this is not a component reference or is one that we can't
2994 do anything with. */
2997 decode_field_reference (tree exp, HOST_WIDE_INT *pbitsize,
2998 HOST_WIDE_INT *pbitpos, enum machine_mode *pmode,
2999 int *punsignedp, int *pvolatilep,
3000 tree *pmask, tree *pand_mask)
3002 tree outer_type = 0;
3004 tree mask, inner, offset;
3006 unsigned int precision;
3008 /* All the optimizations using this function assume integer fields.
3009 There are problems with FP fields since the type_for_size call
3010 below can fail for, e.g., XFmode. */
3011 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
3014 /* We are interested in the bare arrangement of bits, so strip everything
3015 that doesn't affect the machine mode. However, record the type of the
3016 outermost expression if it may matter below. */
3017 if (TREE_CODE (exp) == NOP_EXPR
3018 || TREE_CODE (exp) == CONVERT_EXPR
3019 || TREE_CODE (exp) == NON_LVALUE_EXPR)
3020 outer_type = TREE_TYPE (exp);
3023 if (TREE_CODE (exp) == BIT_AND_EXPR)
3025 and_mask = TREE_OPERAND (exp, 1);
3026 exp = TREE_OPERAND (exp, 0);
3027 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
3028 if (TREE_CODE (and_mask) != INTEGER_CST)
3032 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
3033 punsignedp, pvolatilep);
3034 if ((inner == exp && and_mask == 0)
3035 || *pbitsize < 0 || offset != 0
3036 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
3039 /* If the number of bits in the reference is the same as the bitsize of
3040 the outer type, then the outer type gives the signedness. Otherwise
3041 (in case of a small bitfield) the signedness is unchanged. */
3042 if (outer_type && *pbitsize == tree_low_cst (TYPE_SIZE (outer_type), 1))
3043 *punsignedp = TREE_UNSIGNED (outer_type);
3045 /* Compute the mask to access the bitfield. */
3046 unsigned_type = (*lang_hooks.types.type_for_size) (*pbitsize, 1);
3047 precision = TYPE_PRECISION (unsigned_type);
3049 mask = build_int_2 (~0, ~0);
3050 TREE_TYPE (mask) = unsigned_type;
3051 force_fit_type (mask, 0);
3052 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3053 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3055 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
3057 mask = fold (build (BIT_AND_EXPR, unsigned_type,
3058 fold_convert (unsigned_type, and_mask), mask));
3061 *pand_mask = and_mask;
3065 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
3069 all_ones_mask_p (tree mask, int size)
3071 tree type = TREE_TYPE (mask);
3072 unsigned int precision = TYPE_PRECISION (type);
3075 tmask = build_int_2 (~0, ~0);
3076 TREE_TYPE (tmask) = (*lang_hooks.types.signed_type) (type);
3077 force_fit_type (tmask, 0);
3079 tree_int_cst_equal (mask,
3080 const_binop (RSHIFT_EXPR,
3081 const_binop (LSHIFT_EXPR, tmask,
3082 size_int (precision - size),
3084 size_int (precision - size), 0));
3087 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
3088 represents the sign bit of EXP's type. If EXP represents a sign
3089 or zero extension, also test VAL against the unextended type.
3090 The return value is the (sub)expression whose sign bit is VAL,
3091 or NULL_TREE otherwise. */
3094 sign_bit_p (tree exp, tree val)
3096 unsigned HOST_WIDE_INT mask_lo, lo;
3097 HOST_WIDE_INT mask_hi, hi;
3101 /* Tree EXP must have an integral type. */
3102 t = TREE_TYPE (exp);
3103 if (! INTEGRAL_TYPE_P (t))
3106 /* Tree VAL must be an integer constant. */
3107 if (TREE_CODE (val) != INTEGER_CST
3108 || TREE_CONSTANT_OVERFLOW (val))
3111 width = TYPE_PRECISION (t);
3112 if (width > HOST_BITS_PER_WIDE_INT)
3114 hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1);
3117 mask_hi = ((unsigned HOST_WIDE_INT) -1
3118 >> (2 * HOST_BITS_PER_WIDE_INT - width));
3124 lo = (unsigned HOST_WIDE_INT) 1 << (width - 1);
3127 mask_lo = ((unsigned HOST_WIDE_INT) -1
3128 >> (HOST_BITS_PER_WIDE_INT - width));
3131 /* We mask off those bits beyond TREE_TYPE (exp) so that we can
3132 treat VAL as if it were unsigned. */
3133 if ((TREE_INT_CST_HIGH (val) & mask_hi) == hi
3134 && (TREE_INT_CST_LOW (val) & mask_lo) == lo)
3137 /* Handle extension from a narrower type. */
3138 if (TREE_CODE (exp) == NOP_EXPR
3139 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width)
3140 return sign_bit_p (TREE_OPERAND (exp, 0), val);
3145 /* Subroutine for fold_truthop: determine if an operand is simple enough
3146 to be evaluated unconditionally. */
3149 simple_operand_p (tree exp)
3151 /* Strip any conversions that don't change the machine mode. */
3152 while ((TREE_CODE (exp) == NOP_EXPR
3153 || TREE_CODE (exp) == CONVERT_EXPR)
3154 && (TYPE_MODE (TREE_TYPE (exp))
3155 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)))))
3156 exp = TREE_OPERAND (exp, 0);
3158 return (TREE_CODE_CLASS (TREE_CODE (exp)) == 'c'
3160 && ! TREE_ADDRESSABLE (exp)
3161 && ! TREE_THIS_VOLATILE (exp)
3162 && ! DECL_NONLOCAL (exp)
3163 /* Don't regard global variables as simple. They may be
3164 allocated in ways unknown to the compiler (shared memory,
3165 #pragma weak, etc). */
3166 && ! TREE_PUBLIC (exp)
3167 && ! DECL_EXTERNAL (exp)
3168 /* Loading a static variable is unduly expensive, but global
3169 registers aren't expensive. */
3170 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
3173 /* The following functions are subroutines to fold_range_test and allow it to
3174 try to change a logical combination of comparisons into a range test.
3177 X == 2 || X == 3 || X == 4 || X == 5
3181 (unsigned) (X - 2) <= 3
3183 We describe each set of comparisons as being either inside or outside
3184 a range, using a variable named like IN_P, and then describe the
3185 range with a lower and upper bound. If one of the bounds is omitted,
3186 it represents either the highest or lowest value of the type.
3188 In the comments below, we represent a range by two numbers in brackets
3189 preceded by a "+" to designate being inside that range, or a "-" to
3190 designate being outside that range, so the condition can be inverted by
3191 flipping the prefix. An omitted bound is represented by a "-". For
3192 example, "- [-, 10]" means being outside the range starting at the lowest
3193 possible value and ending at 10, in other words, being greater than 10.
3194 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
3197 We set up things so that the missing bounds are handled in a consistent
3198 manner so neither a missing bound nor "true" and "false" need to be
3199 handled using a special case. */
3201 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
3202 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
3203 and UPPER1_P are nonzero if the respective argument is an upper bound
3204 and zero for a lower. TYPE, if nonzero, is the type of the result; it
3205 must be specified for a comparison. ARG1 will be converted to ARG0's
3206 type if both are specified. */
3209 range_binop (enum tree_code code, tree type, tree arg0, int upper0_p,
3210 tree arg1, int upper1_p)
3216 /* If neither arg represents infinity, do the normal operation.
3217 Else, if not a comparison, return infinity. Else handle the special
3218 comparison rules. Note that most of the cases below won't occur, but
3219 are handled for consistency. */
3221 if (arg0 != 0 && arg1 != 0)
3223 tem = fold (build (code, type != 0 ? type : TREE_TYPE (arg0),
3224 arg0, fold_convert (TREE_TYPE (arg0), arg1)));
3226 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
3229 if (TREE_CODE_CLASS (code) != '<')
3232 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
3233 for neither. In real maths, we cannot assume open ended ranges are
3234 the same. But, this is computer arithmetic, where numbers are finite.
3235 We can therefore make the transformation of any unbounded range with
3236 the value Z, Z being greater than any representable number. This permits
3237 us to treat unbounded ranges as equal. */
3238 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
3239 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
3243 result = sgn0 == sgn1;
3246 result = sgn0 != sgn1;
3249 result = sgn0 < sgn1;
3252 result = sgn0 <= sgn1;
3255 result = sgn0 > sgn1;
3258 result = sgn0 >= sgn1;
3264 return fold_convert (type, result ? integer_one_node : integer_zero_node);
3267 /* Given EXP, a logical expression, set the range it is testing into
3268 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
3269 actually being tested. *PLOW and *PHIGH will be made of the same type
3270 as the returned expression. If EXP is not a comparison, we will most
3271 likely not be returning a useful value and range. */
3274 make_range (tree exp, int *pin_p, tree *plow, tree *phigh)
3276 enum tree_code code;
3277 tree arg0 = NULL_TREE, arg1 = NULL_TREE, type = NULL_TREE;
3278 tree orig_type = NULL_TREE;
3280 tree low, high, n_low, n_high;
3282 /* Start with simply saying "EXP != 0" and then look at the code of EXP
3283 and see if we can refine the range. Some of the cases below may not
3284 happen, but it doesn't seem worth worrying about this. We "continue"
3285 the outer loop when we've changed something; otherwise we "break"
3286 the switch, which will "break" the while. */
3289 low = high = fold_convert (TREE_TYPE (exp), integer_zero_node);
3293 code = TREE_CODE (exp);
3295 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
3297 if (first_rtl_op (code) > 0)
3298 arg0 = TREE_OPERAND (exp, 0);
3299 if (TREE_CODE_CLASS (code) == '<'
3300 || TREE_CODE_CLASS (code) == '1'
3301 || TREE_CODE_CLASS (code) == '2')
3302 type = TREE_TYPE (arg0);
3303 if (TREE_CODE_CLASS (code) == '2'
3304 || TREE_CODE_CLASS (code) == '<'
3305 || (TREE_CODE_CLASS (code) == 'e'
3306 && TREE_CODE_LENGTH (code) > 1))
3307 arg1 = TREE_OPERAND (exp, 1);
3310 /* Set ORIG_TYPE as soon as TYPE is non-null so that we do not
3311 lose a cast by accident. */
3312 if (type != NULL_TREE && orig_type == NULL_TREE)
3317 case TRUTH_NOT_EXPR:
3318 in_p = ! in_p, exp = arg0;
3321 case EQ_EXPR: case NE_EXPR:
3322 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
3323 /* We can only do something if the range is testing for zero
3324 and if the second operand is an integer constant. Note that
3325 saying something is "in" the range we make is done by
3326 complementing IN_P since it will set in the initial case of
3327 being not equal to zero; "out" is leaving it alone. */
3328 if (low == 0 || high == 0
3329 || ! integer_zerop (low) || ! integer_zerop (high)
3330 || TREE_CODE (arg1) != INTEGER_CST)
3335 case NE_EXPR: /* - [c, c] */
3338 case EQ_EXPR: /* + [c, c] */
3339 in_p = ! in_p, low = high = arg1;
3341 case GT_EXPR: /* - [-, c] */
3342 low = 0, high = arg1;
3344 case GE_EXPR: /* + [c, -] */
3345 in_p = ! in_p, low = arg1, high = 0;
3347 case LT_EXPR: /* - [c, -] */
3348 low = arg1, high = 0;
3350 case LE_EXPR: /* + [-, c] */
3351 in_p = ! in_p, low = 0, high = arg1;
3359 /* If this is an unsigned comparison, we also know that EXP is
3360 greater than or equal to zero. We base the range tests we make
3361 on that fact, so we record it here so we can parse existing
3363 if (TREE_UNSIGNED (type) && (low == 0 || high == 0))
3365 if (! merge_ranges (&n_in_p, &n_low, &n_high, in_p, low, high,
3366 1, fold_convert (type, integer_zero_node),
3370 in_p = n_in_p, low = n_low, high = n_high;
3372 /* If the high bound is missing, but we have a nonzero low
3373 bound, reverse the range so it goes from zero to the low bound
3375 if (high == 0 && low && ! integer_zerop (low))
3378 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
3379 integer_one_node, 0);
3380 low = fold_convert (type, integer_zero_node);
3386 /* (-x) IN [a,b] -> x in [-b, -a] */
3387 n_low = range_binop (MINUS_EXPR, type,
3388 fold_convert (type, integer_zero_node),
3390 n_high = range_binop (MINUS_EXPR, type,
3391 fold_convert (type, integer_zero_node),
3393 low = n_low, high = n_high;
3399 exp = build (MINUS_EXPR, type, negate_expr (arg0),
3400 fold_convert (type, integer_one_node));
3403 case PLUS_EXPR: case MINUS_EXPR:
3404 if (TREE_CODE (arg1) != INTEGER_CST)
3407 /* If EXP is signed, any overflow in the computation is undefined,
3408 so we don't worry about it so long as our computations on
3409 the bounds don't overflow. For unsigned, overflow is defined
3410 and this is exactly the right thing. */
3411 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3412 type, low, 0, arg1, 0);
3413 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3414 type, high, 1, arg1, 0);
3415 if ((n_low != 0 && TREE_OVERFLOW (n_low))
3416 || (n_high != 0 && TREE_OVERFLOW (n_high)))
3419 /* Check for an unsigned range which has wrapped around the maximum
3420 value thus making n_high < n_low, and normalize it. */
3421 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
3423 low = range_binop (PLUS_EXPR, type, n_high, 0,
3424 integer_one_node, 0);
3425 high = range_binop (MINUS_EXPR, type, n_low, 0,
3426 integer_one_node, 0);
3428 /* If the range is of the form +/- [ x+1, x ], we won't
3429 be able to normalize it. But then, it represents the
3430 whole range or the empty set, so make it
3432 if (tree_int_cst_equal (n_low, low)
3433 && tree_int_cst_equal (n_high, high))
3439 low = n_low, high = n_high;
3444 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
3445 if (TYPE_PRECISION (type) > TYPE_PRECISION (orig_type))
3448 if (! INTEGRAL_TYPE_P (type)
3449 || (low != 0 && ! int_fits_type_p (low, type))
3450 || (high != 0 && ! int_fits_type_p (high, type)))
3453 n_low = low, n_high = high;
3456 n_low = fold_convert (type, n_low);
3459 n_high = fold_convert (type, n_high);
3461 /* If we're converting from an unsigned to a signed type,
3462 we will be doing the comparison as unsigned. The tests above
3463 have already verified that LOW and HIGH are both positive.
3465 So we have to make sure that the original unsigned value will
3466 be interpreted as positive. */
3467 if (TREE_UNSIGNED (type) && ! TREE_UNSIGNED (TREE_TYPE (exp)))
3469 tree equiv_type = (*lang_hooks.types.type_for_mode)
3470 (TYPE_MODE (type), 1);
3473 /* A range without an upper bound is, naturally, unbounded.
3474 Since convert would have cropped a very large value, use
3475 the max value for the destination type. */
3477 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
3478 : TYPE_MAX_VALUE (type);
3480 if (TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (exp)))
3481 high_positive = fold (build (RSHIFT_EXPR, type,
3485 integer_one_node)));
3487 /* If the low bound is specified, "and" the range with the
3488 range for which the original unsigned value will be
3492 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3493 1, n_low, n_high, 1,
3494 fold_convert (type, integer_zero_node),
3498 in_p = (n_in_p == in_p);
3502 /* Otherwise, "or" the range with the range of the input
3503 that will be interpreted as negative. */
3504 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3505 0, n_low, n_high, 1,
3506 fold_convert (type, integer_zero_node),
3510 in_p = (in_p != n_in_p);
3515 low = n_low, high = n_high;
3525 /* If EXP is a constant, we can evaluate whether this is true or false. */
3526 if (TREE_CODE (exp) == INTEGER_CST)
3528 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
3530 && integer_onep (range_binop (LE_EXPR, integer_type_node,
3536 *pin_p = in_p, *plow = low, *phigh = high;
3540 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3541 type, TYPE, return an expression to test if EXP is in (or out of, depending
3542 on IN_P) the range. */
3545 build_range_check (tree type, tree exp, int in_p, tree low, tree high)
3547 tree etype = TREE_TYPE (exp);
3551 && (0 != (value = build_range_check (type, exp, 1, low, high))))
3552 return invert_truthvalue (value);
3554 if (low == 0 && high == 0)
3555 return fold_convert (type, integer_one_node);
3558 return fold (build (LE_EXPR, type, exp, high));
3561 return fold (build (GE_EXPR, type, exp, low));
3563 if (operand_equal_p (low, high, 0))
3564 return fold (build (EQ_EXPR, type, exp, low));
3566 if (integer_zerop (low))
3568 if (! TREE_UNSIGNED (etype))
3570 etype = (*lang_hooks.types.unsigned_type) (etype);
3571 high = fold_convert (etype, high);
3572 exp = fold_convert (etype, exp);
3574 return build_range_check (type, exp, 1, 0, high);
3577 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
3578 if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST)
3580 unsigned HOST_WIDE_INT lo;
3584 prec = TYPE_PRECISION (etype);
3585 if (prec <= HOST_BITS_PER_WIDE_INT)
3588 lo = ((unsigned HOST_WIDE_INT) 1 << (prec - 1)) - 1;
3592 hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1;
3593 lo = (unsigned HOST_WIDE_INT) -1;
3596 if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo)
3598 if (TREE_UNSIGNED (etype))
3600 etype = (*lang_hooks.types.signed_type) (etype);
3601 exp = fold_convert (etype, exp);
3603 return fold (build (GT_EXPR, type, exp,
3604 fold_convert (etype, integer_zero_node)));
3608 if (0 != (value = const_binop (MINUS_EXPR, high, low, 0))
3609 && ! TREE_OVERFLOW (value))
3610 return build_range_check (type,
3611 fold (build (MINUS_EXPR, etype, exp, low)),
3612 1, fold_convert (etype, integer_zero_node),
3618 /* Given two ranges, see if we can merge them into one. Return 1 if we
3619 can, 0 if we can't. Set the output range into the specified parameters. */
3622 merge_ranges (int *pin_p, tree *plow, tree *phigh, int in0_p, tree low0,
3623 tree high0, int in1_p, tree low1, tree high1)
3631 int lowequal = ((low0 == 0 && low1 == 0)
3632 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3633 low0, 0, low1, 0)));
3634 int highequal = ((high0 == 0 && high1 == 0)
3635 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3636 high0, 1, high1, 1)));
3638 /* Make range 0 be the range that starts first, or ends last if they
3639 start at the same value. Swap them if it isn't. */
3640 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
3643 && integer_onep (range_binop (GT_EXPR, integer_type_node,
3644 high1, 1, high0, 1))))
3646 temp = in0_p, in0_p = in1_p, in1_p = temp;
3647 tem = low0, low0 = low1, low1 = tem;
3648 tem = high0, high0 = high1, high1 = tem;
3651 /* Now flag two cases, whether the ranges are disjoint or whether the
3652 second range is totally subsumed in the first. Note that the tests
3653 below are simplified by the ones above. */
3654 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
3655 high0, 1, low1, 0));
3656 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
3657 high1, 1, high0, 1));
3659 /* We now have four cases, depending on whether we are including or
3660 excluding the two ranges. */
3663 /* If they don't overlap, the result is false. If the second range
3664 is a subset it is the result. Otherwise, the range is from the start
3665 of the second to the end of the first. */
3667 in_p = 0, low = high = 0;
3669 in_p = 1, low = low1, high = high1;
3671 in_p = 1, low = low1, high = high0;
3674 else if (in0_p && ! in1_p)
3676 /* If they don't overlap, the result is the first range. If they are
3677 equal, the result is false. If the second range is a subset of the
3678 first, and the ranges begin at the same place, we go from just after
3679 the end of the first range to the end of the second. If the second
3680 range is not a subset of the first, or if it is a subset and both
3681 ranges end at the same place, the range starts at the start of the
3682 first range and ends just before the second range.
3683 Otherwise, we can't describe this as a single range. */
3685 in_p = 1, low = low0, high = high0;
3686 else if (lowequal && highequal)
3687 in_p = 0, low = high = 0;
3688 else if (subset && lowequal)
3690 in_p = 1, high = high0;
3691 low = range_binop (PLUS_EXPR, NULL_TREE, high1, 0,
3692 integer_one_node, 0);
3694 else if (! subset || highequal)
3696 in_p = 1, low = low0;
3697 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
3698 integer_one_node, 0);
3704 else if (! in0_p && in1_p)
3706 /* If they don't overlap, the result is the second range. If the second
3707 is a subset of the first, the result is false. Otherwise,
3708 the range starts just after the first range and ends at the
3709 end of the second. */
3711 in_p = 1, low = low1, high = high1;
3712 else if (subset || highequal)
3713 in_p = 0, low = high = 0;
3716 in_p = 1, high = high1;
3717 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
3718 integer_one_node, 0);
3724 /* The case where we are excluding both ranges. Here the complex case
3725 is if they don't overlap. In that case, the only time we have a
3726 range is if they are adjacent. If the second is a subset of the
3727 first, the result is the first. Otherwise, the range to exclude
3728 starts at the beginning of the first range and ends at the end of the
3732 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
3733 range_binop (PLUS_EXPR, NULL_TREE,
3735 integer_one_node, 1),
3737 in_p = 0, low = low0, high = high1;
3742 in_p = 0, low = low0, high = high0;
3744 in_p = 0, low = low0, high = high1;
3747 *pin_p = in_p, *plow = low, *phigh = high;
3751 #ifndef RANGE_TEST_NON_SHORT_CIRCUIT
3752 #define RANGE_TEST_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
3755 /* EXP is some logical combination of boolean tests. See if we can
3756 merge it into some range test. Return the new tree if so. */
3759 fold_range_test (tree exp)
3761 int or_op = (TREE_CODE (exp) == TRUTH_ORIF_EXPR
3762 || TREE_CODE (exp) == TRUTH_OR_EXPR);
3763 int in0_p, in1_p, in_p;
3764 tree low0, low1, low, high0, high1, high;
3765 tree lhs = make_range (TREE_OPERAND (exp, 0), &in0_p, &low0, &high0);
3766 tree rhs = make_range (TREE_OPERAND (exp, 1), &in1_p, &low1, &high1);
3769 /* If this is an OR operation, invert both sides; we will invert
3770 again at the end. */
3772 in0_p = ! in0_p, in1_p = ! in1_p;
3774 /* If both expressions are the same, if we can merge the ranges, and we
3775 can build the range test, return it or it inverted. If one of the
3776 ranges is always true or always false, consider it to be the same
3777 expression as the other. */
3778 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
3779 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
3781 && 0 != (tem = (build_range_check (TREE_TYPE (exp),
3783 : rhs != 0 ? rhs : integer_zero_node,
3785 return or_op ? invert_truthvalue (tem) : tem;
3787 /* On machines where the branch cost is expensive, if this is a
3788 short-circuited branch and the underlying object on both sides
3789 is the same, make a non-short-circuit operation. */
3790 else if (RANGE_TEST_NON_SHORT_CIRCUIT
3791 && lhs != 0 && rhs != 0
3792 && (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3793 || TREE_CODE (exp) == TRUTH_ORIF_EXPR)
3794 && operand_equal_p (lhs, rhs, 0))
3796 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
3797 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
3798 which cases we can't do this. */
3799 if (simple_operand_p (lhs))
3800 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3801 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3802 TREE_TYPE (exp), TREE_OPERAND (exp, 0),
3803 TREE_OPERAND (exp, 1));
3805 else if ((*lang_hooks.decls.global_bindings_p) () == 0
3806 && ! CONTAINS_PLACEHOLDER_P (lhs))
3808 tree common = save_expr (lhs);
3810 if (0 != (lhs = build_range_check (TREE_TYPE (exp), common,
3811 or_op ? ! in0_p : in0_p,
3813 && (0 != (rhs = build_range_check (TREE_TYPE (exp), common,
3814 or_op ? ! in1_p : in1_p,
3816 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3817 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3818 TREE_TYPE (exp), lhs, rhs);
3825 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
3826 bit value. Arrange things so the extra bits will be set to zero if and
3827 only if C is signed-extended to its full width. If MASK is nonzero,
3828 it is an INTEGER_CST that should be AND'ed with the extra bits. */
3831 unextend (tree c, int p, int unsignedp, tree mask)
3833 tree type = TREE_TYPE (c);
3834 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
3837 if (p == modesize || unsignedp)
3840 /* We work by getting just the sign bit into the low-order bit, then
3841 into the high-order bit, then sign-extend. We then XOR that value
3843 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
3844 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
3846 /* We must use a signed type in order to get an arithmetic right shift.
3847 However, we must also avoid introducing accidental overflows, so that
3848 a subsequent call to integer_zerop will work. Hence we must
3849 do the type conversion here. At this point, the constant is either
3850 zero or one, and the conversion to a signed type can never overflow.
3851 We could get an overflow if this conversion is done anywhere else. */
3852 if (TREE_UNSIGNED (type))
3853 temp = fold_convert ((*lang_hooks.types.signed_type) (type), temp);
3855 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
3856 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
3858 temp = const_binop (BIT_AND_EXPR, temp,
3859 fold_convert (TREE_TYPE (c), mask), 0);
3860 /* If necessary, convert the type back to match the type of C. */
3861 if (TREE_UNSIGNED (type))
3862 temp = fold_convert (type, temp);
3864 return fold_convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
3867 /* Find ways of folding logical expressions of LHS and RHS:
3868 Try to merge two comparisons to the same innermost item.
3869 Look for range tests like "ch >= '0' && ch <= '9'".
3870 Look for combinations of simple terms on machines with expensive branches
3871 and evaluate the RHS unconditionally.
3873 For example, if we have p->a == 2 && p->b == 4 and we can make an
3874 object large enough to span both A and B, we can do this with a comparison
3875 against the object ANDed with the a mask.
3877 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
3878 operations to do this with one comparison.
3880 We check for both normal comparisons and the BIT_AND_EXPRs made this by
3881 function and the one above.
3883 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
3884 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
3886 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
3889 We return the simplified tree or 0 if no optimization is possible. */
3892 fold_truthop (enum tree_code code, tree truth_type, tree lhs, tree rhs)
3894 /* If this is the "or" of two comparisons, we can do something if
3895 the comparisons are NE_EXPR. If this is the "and", we can do something
3896 if the comparisons are EQ_EXPR. I.e.,
3897 (a->b == 2 && a->c == 4) can become (a->new == NEW).
3899 WANTED_CODE is this operation code. For single bit fields, we can
3900 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
3901 comparison for one-bit fields. */
3903 enum tree_code wanted_code;
3904 enum tree_code lcode, rcode;
3905 tree ll_arg, lr_arg, rl_arg, rr_arg;
3906 tree ll_inner, lr_inner, rl_inner, rr_inner;
3907 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
3908 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
3909 HOST_WIDE_INT xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
3910 HOST_WIDE_INT lnbitsize, lnbitpos, rnbitsize, rnbitpos;
3911 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
3912 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
3913 enum machine_mode lnmode, rnmode;
3914 tree ll_mask, lr_mask, rl_mask, rr_mask;
3915 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
3916 tree l_const, r_const;
3917 tree lntype, rntype, result;
3918 int first_bit, end_bit;
3921 /* Start by getting the comparison codes. Fail if anything is volatile.
3922 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
3923 it were surrounded with a NE_EXPR. */
3925 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
3928 lcode = TREE_CODE (lhs);
3929 rcode = TREE_CODE (rhs);
3931 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
3932 lcode = NE_EXPR, lhs = build (NE_EXPR, truth_type, lhs, integer_zero_node);
3934 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
3935 rcode = NE_EXPR, rhs = build (NE_EXPR, truth_type, rhs, integer_zero_node);
3937 if (TREE_CODE_CLASS (lcode) != '<' || TREE_CODE_CLASS (rcode) != '<')
3940 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
3941 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
3943 ll_arg = TREE_OPERAND (lhs, 0);
3944 lr_arg = TREE_OPERAND (lhs, 1);
3945 rl_arg = TREE_OPERAND (rhs, 0);
3946 rr_arg = TREE_OPERAND (rhs, 1);
3948 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
3949 if (simple_operand_p (ll_arg)
3950 && simple_operand_p (lr_arg)
3951 && !FLOAT_TYPE_P (TREE_TYPE (ll_arg)))
3955 if (operand_equal_p (ll_arg, rl_arg, 0)
3956 && operand_equal_p (lr_arg, rr_arg, 0))
3958 int lcompcode, rcompcode;
3960 lcompcode = comparison_to_compcode (lcode);
3961 rcompcode = comparison_to_compcode (rcode);
3962 compcode = (code == TRUTH_AND_EXPR)
3963 ? lcompcode & rcompcode
3964 : lcompcode | rcompcode;
3966 else if (operand_equal_p (ll_arg, rr_arg, 0)
3967 && operand_equal_p (lr_arg, rl_arg, 0))
3969 int lcompcode, rcompcode;
3971 rcode = swap_tree_comparison (rcode);
3972 lcompcode = comparison_to_compcode (lcode);
3973 rcompcode = comparison_to_compcode (rcode);
3974 compcode = (code == TRUTH_AND_EXPR)
3975 ? lcompcode & rcompcode
3976 : lcompcode | rcompcode;
3981 if (compcode == COMPCODE_TRUE)
3982 return fold_convert (truth_type, integer_one_node);
3983 else if (compcode == COMPCODE_FALSE)
3984 return fold_convert (truth_type, integer_zero_node);
3985 else if (compcode != -1)
3986 return build (compcode_to_comparison (compcode),
3987 truth_type, ll_arg, lr_arg);
3990 /* If the RHS can be evaluated unconditionally and its operands are
3991 simple, it wins to evaluate the RHS unconditionally on machines
3992 with expensive branches. In this case, this isn't a comparison
3993 that can be merged. Avoid doing this if the RHS is a floating-point
3994 comparison since those can trap. */
3996 if (BRANCH_COST >= 2
3997 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
3998 && simple_operand_p (rl_arg)
3999 && simple_operand_p (rr_arg))
4001 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
4002 if (code == TRUTH_OR_EXPR
4003 && lcode == NE_EXPR && integer_zerop (lr_arg)
4004 && rcode == NE_EXPR && integer_zerop (rr_arg)
4005 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
4006 return build (NE_EXPR, truth_type,
4007 build (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
4011 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
4012 if (code == TRUTH_AND_EXPR
4013 && lcode == EQ_EXPR && integer_zerop (lr_arg)
4014 && rcode == EQ_EXPR && integer_zerop (rr_arg)
4015 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
4016 return build (EQ_EXPR, truth_type,
4017 build (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
4021 return build (code, truth_type, lhs, rhs);
4024 /* See if the comparisons can be merged. Then get all the parameters for
4027 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
4028 || (rcode != EQ_EXPR && rcode != NE_EXPR))
4032 ll_inner = decode_field_reference (ll_arg,
4033 &ll_bitsize, &ll_bitpos, &ll_mode,
4034 &ll_unsignedp, &volatilep, &ll_mask,
4036 lr_inner = decode_field_reference (lr_arg,
4037 &lr_bitsize, &lr_bitpos, &lr_mode,
4038 &lr_unsignedp, &volatilep, &lr_mask,
4040 rl_inner = decode_field_reference (rl_arg,
4041 &rl_bitsize, &rl_bitpos, &rl_mode,
4042 &rl_unsignedp, &volatilep, &rl_mask,
4044 rr_inner = decode_field_reference (rr_arg,
4045 &rr_bitsize, &rr_bitpos, &rr_mode,
4046 &rr_unsignedp, &volatilep, &rr_mask,
4049 /* It must be true that the inner operation on the lhs of each
4050 comparison must be the same if we are to be able to do anything.
4051 Then see if we have constants. If not, the same must be true for
4053 if (volatilep || ll_inner == 0 || rl_inner == 0
4054 || ! operand_equal_p (ll_inner, rl_inner, 0))
4057 if (TREE_CODE (lr_arg) == INTEGER_CST
4058 && TREE_CODE (rr_arg) == INTEGER_CST)
4059 l_const = lr_arg, r_const = rr_arg;
4060 else if (lr_inner == 0 || rr_inner == 0
4061 || ! operand_equal_p (lr_inner, rr_inner, 0))
4064 l_const = r_const = 0;
4066 /* If either comparison code is not correct for our logical operation,
4067 fail. However, we can convert a one-bit comparison against zero into
4068 the opposite comparison against that bit being set in the field. */
4070 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
4071 if (lcode != wanted_code)
4073 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
4075 /* Make the left operand unsigned, since we are only interested
4076 in the value of one bit. Otherwise we are doing the wrong
4085 /* This is analogous to the code for l_const above. */
4086 if (rcode != wanted_code)
4088 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
4097 /* After this point all optimizations will generate bit-field
4098 references, which we might not want. */
4099 if (! (*lang_hooks.can_use_bit_fields_p) ())
4102 /* See if we can find a mode that contains both fields being compared on
4103 the left. If we can't, fail. Otherwise, update all constants and masks
4104 to be relative to a field of that size. */
4105 first_bit = MIN (ll_bitpos, rl_bitpos);
4106 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
4107 lnmode = get_best_mode (end_bit - first_bit, first_bit,
4108 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
4110 if (lnmode == VOIDmode)
4113 lnbitsize = GET_MODE_BITSIZE (lnmode);
4114 lnbitpos = first_bit & ~ (lnbitsize - 1);
4115 lntype = (*lang_hooks.types.type_for_size) (lnbitsize, 1);
4116 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
4118 if (BYTES_BIG_ENDIAN)
4120 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
4121 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
4124 ll_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, ll_mask),
4125 size_int (xll_bitpos), 0);
4126 rl_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, rl_mask),
4127 size_int (xrl_bitpos), 0);
4131 l_const = fold_convert (lntype, l_const);
4132 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
4133 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
4134 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
4135 fold (build1 (BIT_NOT_EXPR,
4139 warning ("comparison is always %d", wanted_code == NE_EXPR);
4141 return fold_convert (truth_type,
4142 wanted_code == NE_EXPR
4143 ? integer_one_node : integer_zero_node);
4148 r_const = fold_convert (lntype, r_const);
4149 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
4150 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
4151 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
4152 fold (build1 (BIT_NOT_EXPR,
4156 warning ("comparison is always %d", wanted_code == NE_EXPR);
4158 return fold_convert (truth_type,
4159 wanted_code == NE_EXPR
4160 ? integer_one_node : integer_zero_node);
4164 /* If the right sides are not constant, do the same for it. Also,
4165 disallow this optimization if a size or signedness mismatch occurs
4166 between the left and right sides. */
4169 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
4170 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
4171 /* Make sure the two fields on the right
4172 correspond to the left without being swapped. */
4173 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
4176 first_bit = MIN (lr_bitpos, rr_bitpos);
4177 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
4178 rnmode = get_best_mode (end_bit - first_bit, first_bit,
4179 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
4181 if (rnmode == VOIDmode)
4184 rnbitsize = GET_MODE_BITSIZE (rnmode);
4185 rnbitpos = first_bit & ~ (rnbitsize - 1);
4186 rntype = (*lang_hooks.types.type_for_size) (rnbitsize, 1);
4187 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
4189 if (BYTES_BIG_ENDIAN)
4191 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
4192 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
4195 lr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, lr_mask),
4196 size_int (xlr_bitpos), 0);
4197 rr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, rr_mask),
4198 size_int (xrr_bitpos), 0);
4200 /* Make a mask that corresponds to both fields being compared.
4201 Do this for both items being compared. If the operands are the
4202 same size and the bits being compared are in the same position
4203 then we can do this by masking both and comparing the masked
4205 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4206 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
4207 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
4209 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4210 ll_unsignedp || rl_unsignedp);
4211 if (! all_ones_mask_p (ll_mask, lnbitsize))
4212 lhs = build (BIT_AND_EXPR, lntype, lhs, ll_mask);
4214 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
4215 lr_unsignedp || rr_unsignedp);
4216 if (! all_ones_mask_p (lr_mask, rnbitsize))
4217 rhs = build (BIT_AND_EXPR, rntype, rhs, lr_mask);
4219 return build (wanted_code, truth_type, lhs, rhs);
4222 /* There is still another way we can do something: If both pairs of
4223 fields being compared are adjacent, we may be able to make a wider
4224 field containing them both.
4226 Note that we still must mask the lhs/rhs expressions. Furthermore,
4227 the mask must be shifted to account for the shift done by
4228 make_bit_field_ref. */
4229 if ((ll_bitsize + ll_bitpos == rl_bitpos
4230 && lr_bitsize + lr_bitpos == rr_bitpos)
4231 || (ll_bitpos == rl_bitpos + rl_bitsize
4232 && lr_bitpos == rr_bitpos + rr_bitsize))
4236 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
4237 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
4238 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
4239 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
4241 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
4242 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
4243 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
4244 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
4246 /* Convert to the smaller type before masking out unwanted bits. */
4248 if (lntype != rntype)
4250 if (lnbitsize > rnbitsize)
4252 lhs = fold_convert (rntype, lhs);
4253 ll_mask = fold_convert (rntype, ll_mask);
4256 else if (lnbitsize < rnbitsize)
4258 rhs = fold_convert (lntype, rhs);
4259 lr_mask = fold_convert (lntype, lr_mask);
4264 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
4265 lhs = build (BIT_AND_EXPR, type, lhs, ll_mask);
4267 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
4268 rhs = build (BIT_AND_EXPR, type, rhs, lr_mask);
4270 return build (wanted_code, truth_type, lhs, rhs);
4276 /* Handle the case of comparisons with constants. If there is something in
4277 common between the masks, those bits of the constants must be the same.
4278 If not, the condition is always false. Test for this to avoid generating
4279 incorrect code below. */
4280 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
4281 if (! integer_zerop (result)
4282 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
4283 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
4285 if (wanted_code == NE_EXPR)
4287 warning ("`or' of unmatched not-equal tests is always 1");
4288 return fold_convert (truth_type, integer_one_node);
4292 warning ("`and' of mutually exclusive equal-tests is always 0");
4293 return fold_convert (truth_type, integer_zero_node);
4297 /* Construct the expression we will return. First get the component
4298 reference we will make. Unless the mask is all ones the width of
4299 that field, perform the mask operation. Then compare with the
4301 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4302 ll_unsignedp || rl_unsignedp);
4304 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4305 if (! all_ones_mask_p (ll_mask, lnbitsize))
4306 result = build (BIT_AND_EXPR, lntype, result, ll_mask);
4308 return build (wanted_code, truth_type, result,
4309 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
4312 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
4316 optimize_minmax_comparison (tree t)
4318 tree type = TREE_TYPE (t);
4319 tree arg0 = TREE_OPERAND (t, 0);
4320 enum tree_code op_code;
4321 tree comp_const = TREE_OPERAND (t, 1);
4323 int consts_equal, consts_lt;
4326 STRIP_SIGN_NOPS (arg0);
4328 op_code = TREE_CODE (arg0);
4329 minmax_const = TREE_OPERAND (arg0, 1);
4330 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
4331 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
4332 inner = TREE_OPERAND (arg0, 0);
4334 /* If something does not permit us to optimize, return the original tree. */
4335 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
4336 || TREE_CODE (comp_const) != INTEGER_CST
4337 || TREE_CONSTANT_OVERFLOW (comp_const)
4338 || TREE_CODE (minmax_const) != INTEGER_CST
4339 || TREE_CONSTANT_OVERFLOW (minmax_const))
4342 /* Now handle all the various comparison codes. We only handle EQ_EXPR
4343 and GT_EXPR, doing the rest with recursive calls using logical
4345 switch (TREE_CODE (t))
4347 case NE_EXPR: case LT_EXPR: case LE_EXPR:
4349 invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t)));
4353 fold (build (TRUTH_ORIF_EXPR, type,
4354 optimize_minmax_comparison
4355 (build (EQ_EXPR, type, arg0, comp_const)),
4356 optimize_minmax_comparison
4357 (build (GT_EXPR, type, arg0, comp_const))));
4360 if (op_code == MAX_EXPR && consts_equal)
4361 /* MAX (X, 0) == 0 -> X <= 0 */
4362 return fold (build (LE_EXPR, type, inner, comp_const));
4364 else if (op_code == MAX_EXPR && consts_lt)
4365 /* MAX (X, 0) == 5 -> X == 5 */
4366 return fold (build (EQ_EXPR, type, inner, comp_const));
4368 else if (op_code == MAX_EXPR)
4369 /* MAX (X, 0) == -1 -> false */
4370 return omit_one_operand (type, integer_zero_node, inner);
4372 else if (consts_equal)
4373 /* MIN (X, 0) == 0 -> X >= 0 */
4374 return fold (build (GE_EXPR, type, inner, comp_const));
4377 /* MIN (X, 0) == 5 -> false */
4378 return omit_one_operand (type, integer_zero_node, inner);
4381 /* MIN (X, 0) == -1 -> X == -1 */
4382 return fold (build (EQ_EXPR, type, inner, comp_const));
4385 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
4386 /* MAX (X, 0) > 0 -> X > 0
4387 MAX (X, 0) > 5 -> X > 5 */
4388 return fold (build (GT_EXPR, type, inner, comp_const));
4390 else if (op_code == MAX_EXPR)
4391 /* MAX (X, 0) > -1 -> true */
4392 return omit_one_operand (type, integer_one_node, inner);
4394 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
4395 /* MIN (X, 0) > 0 -> false
4396 MIN (X, 0) > 5 -> false */
4397 return omit_one_operand (type, integer_zero_node, inner);
4400 /* MIN (X, 0) > -1 -> X > -1 */
4401 return fold (build (GT_EXPR, type, inner, comp_const));
4408 /* T is an integer expression that is being multiplied, divided, or taken a
4409 modulus (CODE says which and what kind of divide or modulus) by a
4410 constant C. See if we can eliminate that operation by folding it with
4411 other operations already in T. WIDE_TYPE, if non-null, is a type that
4412 should be used for the computation if wider than our type.
4414 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
4415 (X * 2) + (Y * 4). We must, however, be assured that either the original
4416 expression would not overflow or that overflow is undefined for the type
4417 in the language in question.
4419 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
4420 the machine has a multiply-accumulate insn or that this is part of an
4421 addressing calculation.
4423 If we return a non-null expression, it is an equivalent form of the
4424 original computation, but need not be in the original type. */
4427 extract_muldiv (tree t, tree c, enum tree_code code, tree wide_type)
4429 /* To avoid exponential search depth, refuse to allow recursion past
4430 three levels. Beyond that (1) it's highly unlikely that we'll find
4431 something interesting and (2) we've probably processed it before
4432 when we built the inner expression. */
4441 ret = extract_muldiv_1 (t, c, code, wide_type);
4448 extract_muldiv_1 (tree t, tree c, enum tree_code code, tree wide_type)
4450 tree type = TREE_TYPE (t);
4451 enum tree_code tcode = TREE_CODE (t);
4452 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
4453 > GET_MODE_SIZE (TYPE_MODE (type)))
4454 ? wide_type : type);
4456 int same_p = tcode == code;
4457 tree op0 = NULL_TREE, op1 = NULL_TREE;
4459 /* Don't deal with constants of zero here; they confuse the code below. */
4460 if (integer_zerop (c))
4463 if (TREE_CODE_CLASS (tcode) == '1')
4464 op0 = TREE_OPERAND (t, 0);
4466 if (TREE_CODE_CLASS (tcode) == '2')
4467 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
4469 /* Note that we need not handle conditional operations here since fold
4470 already handles those cases. So just do arithmetic here. */
4474 /* For a constant, we can always simplify if we are a multiply
4475 or (for divide and modulus) if it is a multiple of our constant. */
4476 if (code == MULT_EXPR
4477 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
4478 return const_binop (code, fold_convert (ctype, t),
4479 fold_convert (ctype, c), 0);
4482 case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
4483 /* If op0 is an expression ... */
4484 if ((TREE_CODE_CLASS (TREE_CODE (op0)) == '<'
4485 || TREE_CODE_CLASS (TREE_CODE (op0)) == '1'
4486 || TREE_CODE_CLASS (TREE_CODE (op0)) == '2'
4487 || TREE_CODE_CLASS (TREE_CODE (op0)) == 'e')
4488 /* ... and is unsigned, and its type is smaller than ctype,
4489 then we cannot pass through as widening. */
4490 && ((TREE_UNSIGNED (TREE_TYPE (op0))
4491 && ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
4492 && TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
4493 && (GET_MODE_SIZE (TYPE_MODE (ctype))
4494 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
4495 /* ... or its type is larger than ctype,
4496 then we cannot pass through this truncation. */
4497 || (GET_MODE_SIZE (TYPE_MODE (ctype))
4498 < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0))))
4499 /* ... or signedness changes for division or modulus,
4500 then we cannot pass through this conversion. */
4501 || (code != MULT_EXPR
4502 && (TREE_UNSIGNED (ctype)
4503 != TREE_UNSIGNED (TREE_TYPE (op0))))))
4506 /* Pass the constant down and see if we can make a simplification. If
4507 we can, replace this expression with the inner simplification for
4508 possible later conversion to our or some other type. */
4509 if ((t2 = fold_convert (TREE_TYPE (op0), c)) != 0
4510 && TREE_CODE (t2) == INTEGER_CST
4511 && ! TREE_CONSTANT_OVERFLOW (t2)
4512 && (0 != (t1 = extract_muldiv (op0, t2, code,
4514 ? ctype : NULL_TREE))))
4518 case NEGATE_EXPR: case ABS_EXPR:
4519 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4520 return fold (build1 (tcode, ctype, fold_convert (ctype, t1)));
4523 case MIN_EXPR: case MAX_EXPR:
4524 /* If widening the type changes the signedness, then we can't perform
4525 this optimization as that changes the result. */
4526 if (TREE_UNSIGNED (ctype) != TREE_UNSIGNED (type))
4529 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
4530 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0
4531 && (t2 = extract_muldiv (op1, c, code, wide_type)) != 0)
4533 if (tree_int_cst_sgn (c) < 0)
4534 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
4536 return fold (build (tcode, ctype, fold_convert (ctype, t1),
4537 fold_convert (ctype, t2)));
4541 case WITH_RECORD_EXPR:
4542 if ((t1 = extract_muldiv (TREE_OPERAND (t, 0), c, code, wide_type)) != 0)
4543 return build (WITH_RECORD_EXPR, TREE_TYPE (t1), t1,
4544 TREE_OPERAND (t, 1));
4547 case LSHIFT_EXPR: case RSHIFT_EXPR:
4548 /* If the second operand is constant, this is a multiplication
4549 or floor division, by a power of two, so we can treat it that
4550 way unless the multiplier or divisor overflows. */
4551 if (TREE_CODE (op1) == INTEGER_CST
4552 /* const_binop may not detect overflow correctly,
4553 so check for it explicitly here. */
4554 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
4555 && TREE_INT_CST_HIGH (op1) == 0
4556 && 0 != (t1 = fold_convert (ctype,
4557 const_binop (LSHIFT_EXPR,
4560 && ! TREE_OVERFLOW (t1))
4561 return extract_muldiv (build (tcode == LSHIFT_EXPR
4562 ? MULT_EXPR : FLOOR_DIV_EXPR,
4563 ctype, fold_convert (ctype, op0), t1),
4564 c, code, wide_type);
4567 case PLUS_EXPR: case MINUS_EXPR:
4568 /* See if we can eliminate the operation on both sides. If we can, we
4569 can return a new PLUS or MINUS. If we can't, the only remaining
4570 cases where we can do anything are if the second operand is a
4572 t1 = extract_muldiv (op0, c, code, wide_type);
4573 t2 = extract_muldiv (op1, c, code, wide_type);
4574 if (t1 != 0 && t2 != 0
4575 && (code == MULT_EXPR
4576 /* If not multiplication, we can only do this if both operands
4577 are divisible by c. */
4578 || (multiple_of_p (ctype, op0, c)
4579 && multiple_of_p (ctype, op1, c))))
4580 return fold (build (tcode, ctype, fold_convert (ctype, t1),
4581 fold_convert (ctype, t2)));
4583 /* If this was a subtraction, negate OP1 and set it to be an addition.
4584 This simplifies the logic below. */
4585 if (tcode == MINUS_EXPR)
4586 tcode = PLUS_EXPR, op1 = negate_expr (op1);
4588 if (TREE_CODE (op1) != INTEGER_CST)
4591 /* If either OP1 or C are negative, this optimization is not safe for
4592 some of the division and remainder types while for others we need
4593 to change the code. */
4594 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
4596 if (code == CEIL_DIV_EXPR)
4597 code = FLOOR_DIV_EXPR;
4598 else if (code == FLOOR_DIV_EXPR)
4599 code = CEIL_DIV_EXPR;
4600 else if (code != MULT_EXPR
4601 && code != CEIL_MOD_EXPR && code != FLOOR_MOD_EXPR)
4605 /* If it's a multiply or a division/modulus operation of a multiple
4606 of our constant, do the operation and verify it doesn't overflow. */
4607 if (code == MULT_EXPR
4608 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4610 op1 = const_binop (code, fold_convert (ctype, op1),
4611 fold_convert (ctype, c), 0);
4612 /* We allow the constant to overflow with wrapping semantics. */
4614 || (TREE_OVERFLOW (op1) && ! flag_wrapv))
4620 /* If we have an unsigned type is not a sizetype, we cannot widen
4621 the operation since it will change the result if the original
4622 computation overflowed. */
4623 if (TREE_UNSIGNED (ctype)
4624 && ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
4628 /* If we were able to eliminate our operation from the first side,
4629 apply our operation to the second side and reform the PLUS. */
4630 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
4631 return fold (build (tcode, ctype, fold_convert (ctype, t1), op1));
4633 /* The last case is if we are a multiply. In that case, we can
4634 apply the distributive law to commute the multiply and addition
4635 if the multiplication of the constants doesn't overflow. */
4636 if (code == MULT_EXPR)
4637 return fold (build (tcode, ctype,
4638 fold (build (code, ctype,
4639 fold_convert (ctype, op0),
4640 fold_convert (ctype, c))),
4646 /* We have a special case here if we are doing something like
4647 (C * 8) % 4 since we know that's zero. */
4648 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
4649 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
4650 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
4651 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4652 return omit_one_operand (type, integer_zero_node, op0);
4654 /* ... fall through ... */
4656 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
4657 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
4658 /* If we can extract our operation from the LHS, do so and return a
4659 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
4660 do something only if the second operand is a constant. */
4662 && (t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4663 return fold (build (tcode, ctype, fold_convert (ctype, t1),
4664 fold_convert (ctype, op1)));
4665 else if (tcode == MULT_EXPR && code == MULT_EXPR
4666 && (t1 = extract_muldiv (op1, c, code, wide_type)) != 0)
4667 return fold (build (tcode, ctype, fold_convert (ctype, op0),
4668 fold_convert (ctype, t1)));
4669 else if (TREE_CODE (op1) != INTEGER_CST)
4672 /* If these are the same operation types, we can associate them
4673 assuming no overflow. */
4675 && 0 != (t1 = const_binop (MULT_EXPR, fold_convert (ctype, op1),
4676 fold_convert (ctype, c), 0))
4677 && ! TREE_OVERFLOW (t1))
4678 return fold (build (tcode, ctype, fold_convert (ctype, op0), t1));
4680 /* If these operations "cancel" each other, we have the main
4681 optimizations of this pass, which occur when either constant is a
4682 multiple of the other, in which case we replace this with either an
4683 operation or CODE or TCODE.
4685 If we have an unsigned type that is not a sizetype, we cannot do
4686 this since it will change the result if the original computation
4688 if ((! TREE_UNSIGNED (ctype)
4689 || (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
4691 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
4692 || (tcode == MULT_EXPR
4693 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
4694 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR)))
4696 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4697 return fold (build (tcode, ctype, fold_convert (ctype, op0),
4698 fold_convert (ctype,
4699 const_binop (TRUNC_DIV_EXPR,
4701 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
4702 return fold (build (code, ctype, fold_convert (ctype, op0),
4703 fold_convert (ctype,
4704 const_binop (TRUNC_DIV_EXPR,
4716 /* If T contains a COMPOUND_EXPR which was inserted merely to evaluate
4717 S, a SAVE_EXPR, return the expression actually being evaluated. Note
4718 that we may sometimes modify the tree. */
4721 strip_compound_expr (tree t, tree s)
4723 enum tree_code code = TREE_CODE (t);
4725 /* See if this is the COMPOUND_EXPR we want to eliminate. */
4726 if (code == COMPOUND_EXPR && TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR
4727 && TREE_OPERAND (TREE_OPERAND (t, 0), 0) == s)
4728 return TREE_OPERAND (t, 1);
4730 /* See if this is a COND_EXPR or a simple arithmetic operator. We
4731 don't bother handling any other types. */
4732 else if (code == COND_EXPR)
4734 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4735 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4736 TREE_OPERAND (t, 2) = strip_compound_expr (TREE_OPERAND (t, 2), s);
4738 else if (TREE_CODE_CLASS (code) == '1')
4739 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4740 else if (TREE_CODE_CLASS (code) == '<'
4741 || TREE_CODE_CLASS (code) == '2')
4743 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4744 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4750 /* Return a node which has the indicated constant VALUE (either 0 or
4751 1), and is of the indicated TYPE. */
4754 constant_boolean_node (int value, tree type)
4756 if (type == integer_type_node)
4757 return value ? integer_one_node : integer_zero_node;
4758 else if (TREE_CODE (type) == BOOLEAN_TYPE)
4759 return (*lang_hooks.truthvalue_conversion) (value ? integer_one_node :
4763 tree t = build_int_2 (value, 0);
4765 TREE_TYPE (t) = type;
4770 /* Utility function for the following routine, to see how complex a nesting of
4771 COND_EXPRs can be. EXPR is the expression and LIMIT is a count beyond which
4772 we don't care (to avoid spending too much time on complex expressions.). */
4775 count_cond (tree expr, int lim)
4779 if (TREE_CODE (expr) != COND_EXPR)
4784 ctrue = count_cond (TREE_OPERAND (expr, 1), lim - 1);
4785 cfalse = count_cond (TREE_OPERAND (expr, 2), lim - 1 - ctrue);
4786 return MIN (lim, 1 + ctrue + cfalse);
4789 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
4790 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
4791 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
4792 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
4793 COND is the first argument to CODE; otherwise (as in the example
4794 given here), it is the second argument. TYPE is the type of the
4795 original expression. */
4798 fold_binary_op_with_conditional_arg (enum tree_code code, tree type,
4799 tree cond, tree arg, int cond_first_p)
4801 tree test, true_value, false_value;
4802 tree lhs = NULL_TREE;
4803 tree rhs = NULL_TREE;
4804 /* In the end, we'll produce a COND_EXPR. Both arms of the
4805 conditional expression will be binary operations. The left-hand
4806 side of the expression to be executed if the condition is true
4807 will be pointed to by TRUE_LHS. Similarly, the right-hand side
4808 of the expression to be executed if the condition is true will be
4809 pointed to by TRUE_RHS. FALSE_LHS and FALSE_RHS are analogous --
4810 but apply to the expression to be executed if the conditional is
4816 /* These are the codes to use for the left-hand side and right-hand
4817 side of the COND_EXPR. Normally, they are the same as CODE. */
4818 enum tree_code lhs_code = code;
4819 enum tree_code rhs_code = code;
4820 /* And these are the types of the expressions. */
4821 tree lhs_type = type;
4822 tree rhs_type = type;
4827 true_rhs = false_rhs = &arg;
4828 true_lhs = &true_value;
4829 false_lhs = &false_value;
4833 true_lhs = false_lhs = &arg;
4834 true_rhs = &true_value;
4835 false_rhs = &false_value;
4838 if (TREE_CODE (cond) == COND_EXPR)
4840 test = TREE_OPERAND (cond, 0);
4841 true_value = TREE_OPERAND (cond, 1);
4842 false_value = TREE_OPERAND (cond, 2);
4843 /* If this operand throws an expression, then it does not make
4844 sense to try to perform a logical or arithmetic operation
4845 involving it. Instead of building `a + throw 3' for example,
4846 we simply build `a, throw 3'. */
4847 if (VOID_TYPE_P (TREE_TYPE (true_value)))
4851 lhs_code = COMPOUND_EXPR;
4852 lhs_type = void_type_node;
4857 if (VOID_TYPE_P (TREE_TYPE (false_value)))
4861 rhs_code = COMPOUND_EXPR;
4862 rhs_type = void_type_node;
4870 tree testtype = TREE_TYPE (cond);
4872 true_value = fold_convert (testtype, integer_one_node);
4873 false_value = fold_convert (testtype, integer_zero_node);
4876 /* If ARG is complex we want to make sure we only evaluate it once. Though
4877 this is only required if it is volatile, it might be more efficient even
4878 if it is not. However, if we succeed in folding one part to a constant,
4879 we do not need to make this SAVE_EXPR. Since we do this optimization
4880 primarily to see if we do end up with constant and this SAVE_EXPR
4881 interferes with later optimizations, suppressing it when we can is
4884 If we are not in a function, we can't make a SAVE_EXPR, so don't try to
4885 do so. Don't try to see if the result is a constant if an arm is a
4886 COND_EXPR since we get exponential behavior in that case. */
4888 if (saved_expr_p (arg))
4890 else if (lhs == 0 && rhs == 0
4891 && !TREE_CONSTANT (arg)
4892 && (*lang_hooks.decls.global_bindings_p) () == 0
4893 && ((TREE_CODE (arg) != VAR_DECL && TREE_CODE (arg) != PARM_DECL)
4894 || TREE_SIDE_EFFECTS (arg)))
4896 if (TREE_CODE (true_value) != COND_EXPR)
4897 lhs = fold (build (lhs_code, lhs_type, *true_lhs, *true_rhs));
4899 if (TREE_CODE (false_value) != COND_EXPR)
4900 rhs = fold (build (rhs_code, rhs_type, *false_lhs, *false_rhs));
4902 if ((lhs == 0 || ! TREE_CONSTANT (lhs))
4903 && (rhs == 0 || !TREE_CONSTANT (rhs)))
4905 arg = save_expr (arg);
4907 save = saved_expr_p (arg);
4912 lhs = fold (build (lhs_code, lhs_type, *true_lhs, *true_rhs));
4914 rhs = fold (build (rhs_code, rhs_type, *false_lhs, *false_rhs));
4916 test = fold (build (COND_EXPR, type, test, lhs, rhs));
4918 /* If ARG involves a SAVE_EXPR, we need to ensure it is evaluated
4919 ahead of the COND_EXPR we made. Otherwise we would have it only
4920 evaluated in one branch, with the other branch using the result
4921 but missing the evaluation code. Beware that the save_expr call
4922 above might not return a SAVE_EXPR, so testing the TREE_CODE
4923 of ARG is not enough to decide here. Â */
4925 return build (COMPOUND_EXPR, type,
4926 fold_convert (void_type_node, arg),
4927 strip_compound_expr (test, arg));
4929 return fold_convert (type, test);
4933 /* Subroutine of fold() that checks for the addition of +/- 0.0.
4935 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
4936 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
4937 ADDEND is the same as X.
4939 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
4940 and finite. The problematic cases are when X is zero, and its mode
4941 has signed zeros. In the case of rounding towards -infinity,
4942 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
4943 modes, X + 0 is not the same as X because -0 + 0 is 0. */
4946 fold_real_zero_addition_p (tree type, tree addend, int negate)
4948 if (!real_zerop (addend))
4951 /* Don't allow the fold with -fsignaling-nans. */
4952 if (HONOR_SNANS (TYPE_MODE (type)))
4955 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
4956 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
4959 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
4960 if (TREE_CODE (addend) == REAL_CST
4961 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
4964 /* The mode has signed zeros, and we have to honor their sign.
4965 In this situation, there is only one case we can return true for.
4966 X - 0 is the same as X unless rounding towards -infinity is
4968 return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
4971 /* Subroutine of fold() that checks comparisons of built-in math
4972 functions against real constants.
4974 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
4975 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
4976 is the type of the result and ARG0 and ARG1 are the operands of the
4977 comparison. ARG1 must be a TREE_REAL_CST.
4979 The function returns the constant folded tree if a simplification
4980 can be made, and NULL_TREE otherwise. */
4983 fold_mathfn_compare (enum built_in_function fcode, enum tree_code code,
4984 tree type, tree arg0, tree arg1)
4988 if (BUILTIN_SQRT_P (fcode))
4990 tree arg = TREE_VALUE (TREE_OPERAND (arg0, 1));
4991 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg0));
4993 c = TREE_REAL_CST (arg1);
4994 if (REAL_VALUE_NEGATIVE (c))
4996 /* sqrt(x) < y is always false, if y is negative. */
4997 if (code == EQ_EXPR || code == LT_EXPR || code == LE_EXPR)
4998 return omit_one_operand (type,
4999 fold_convert (type, integer_zero_node),
5002 /* sqrt(x) > y is always true, if y is negative and we
5003 don't care about NaNs, i.e. negative values of x. */
5004 if (code == NE_EXPR || !HONOR_NANS (mode))
5005 return omit_one_operand (type,
5006 fold_convert (type, integer_one_node),
5009 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
5010 return fold (build (GE_EXPR, type, arg,
5011 build_real (TREE_TYPE (arg), dconst0)));
5013 else if (code == GT_EXPR || code == GE_EXPR)
5017 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
5018 real_convert (&c2, mode, &c2);
5020 if (REAL_VALUE_ISINF (c2))
5022 /* sqrt(x) > y is x == +Inf, when y is very large. */
5023 if (HONOR_INFINITIES (mode))
5024 return fold (build (EQ_EXPR, type, arg,
5025 build_real (TREE_TYPE (arg), c2)));
5027 /* sqrt(x) > y is always false, when y is very large
5028 and we don't care about infinities. */
5029 return omit_one_operand (type,
5030 fold_convert (type, integer_zero_node),
5034 /* sqrt(x) > c is the same as x > c*c. */
5035 return fold (build (code, type, arg,
5036 build_real (TREE_TYPE (arg), c2)));
5038 else if (code == LT_EXPR || code == LE_EXPR)
5042 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
5043 real_convert (&c2, mode, &c2);
5045 if (REAL_VALUE_ISINF (c2))
5047 /* sqrt(x) < y is always true, when y is a very large
5048 value and we don't care about NaNs or Infinities. */
5049 if (! HONOR_NANS (mode) && ! HONOR_INFINITIES (mode))
5050 return omit_one_operand (type,
5051 fold_convert (type, integer_one_node),
5054 /* sqrt(x) < y is x != +Inf when y is very large and we
5055 don't care about NaNs. */
5056 if (! HONOR_NANS (mode))
5057 return fold (build (NE_EXPR, type, arg,
5058 build_real (TREE_TYPE (arg), c2)));
5060 /* sqrt(x) < y is x >= 0 when y is very large and we
5061 don't care about Infinities. */
5062 if (! HONOR_INFINITIES (mode))
5063 return fold (build (GE_EXPR, type, arg,
5064 build_real (TREE_TYPE (arg), dconst0)));
5066 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
5067 if ((*lang_hooks.decls.global_bindings_p) () != 0
5068 || CONTAINS_PLACEHOLDER_P (arg))
5071 arg = save_expr (arg);
5072 return fold (build (TRUTH_ANDIF_EXPR, type,
5073 fold (build (GE_EXPR, type, arg,
5074 build_real (TREE_TYPE (arg),
5076 fold (build (NE_EXPR, type, arg,
5077 build_real (TREE_TYPE (arg),
5081 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
5082 if (! HONOR_NANS (mode))
5083 return fold (build (code, type, arg,
5084 build_real (TREE_TYPE (arg), c2)));
5086 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
5087 if ((*lang_hooks.decls.global_bindings_p) () == 0
5088 && ! CONTAINS_PLACEHOLDER_P (arg))
5090 arg = save_expr (arg);
5091 return fold (build (TRUTH_ANDIF_EXPR, type,
5092 fold (build (GE_EXPR, type, arg,
5093 build_real (TREE_TYPE (arg),
5095 fold (build (code, type, arg,
5096 build_real (TREE_TYPE (arg),
5105 /* Subroutine of fold() that optimizes comparisons against Infinities,
5106 either +Inf or -Inf.
5108 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
5109 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
5110 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
5112 The function returns the constant folded tree if a simplification
5113 can be made, and NULL_TREE otherwise. */
5116 fold_inf_compare (enum tree_code code, tree type, tree arg0, tree arg1)
5118 enum machine_mode mode;
5119 REAL_VALUE_TYPE max;
5123 mode = TYPE_MODE (TREE_TYPE (arg0));
5125 /* For negative infinity swap the sense of the comparison. */
5126 neg = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1));
5128 code = swap_tree_comparison (code);
5133 /* x > +Inf is always false, if with ignore sNANs. */
5134 if (HONOR_SNANS (mode))
5136 return omit_one_operand (type,
5137 fold_convert (type, integer_zero_node),
5141 /* x <= +Inf is always true, if we don't case about NaNs. */
5142 if (! HONOR_NANS (mode))
5143 return omit_one_operand (type,
5144 fold_convert (type, integer_one_node),
5147 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
5148 if ((*lang_hooks.decls.global_bindings_p) () == 0
5149 && ! CONTAINS_PLACEHOLDER_P (arg0))
5151 arg0 = save_expr (arg0);
5152 return fold (build (EQ_EXPR, type, arg0, arg0));
5158 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
5159 real_maxval (&max, neg, mode);
5160 return fold (build (neg ? LT_EXPR : GT_EXPR, type,
5161 arg0, build_real (TREE_TYPE (arg0), max)));
5164 /* x < +Inf is always equal to x <= DBL_MAX. */
5165 real_maxval (&max, neg, mode);
5166 return fold (build (neg ? GE_EXPR : LE_EXPR, type,
5167 arg0, build_real (TREE_TYPE (arg0), max)));
5170 /* x != +Inf is always equal to !(x > DBL_MAX). */
5171 real_maxval (&max, neg, mode);
5172 if (! HONOR_NANS (mode))
5173 return fold (build (neg ? GE_EXPR : LE_EXPR, type,
5174 arg0, build_real (TREE_TYPE (arg0), max)));
5175 temp = fold (build (neg ? LT_EXPR : GT_EXPR, type,
5176 arg0, build_real (TREE_TYPE (arg0), max)));
5177 return fold (build1 (TRUTH_NOT_EXPR, type, temp));
5186 /* If CODE with arguments ARG0 and ARG1 represents a single bit
5187 equality/inequality test, then return a simplified form of
5188 the test using shifts and logical operations. Otherwise return
5189 NULL. TYPE is the desired result type. */
5192 fold_single_bit_test (enum tree_code code, tree arg0, tree arg1,
5195 /* If this is a TRUTH_NOT_EXPR, it may have a single bit test inside
5197 if (code == TRUTH_NOT_EXPR)
5199 code = TREE_CODE (arg0);
5200 if (code != NE_EXPR && code != EQ_EXPR)
5203 /* Extract the arguments of the EQ/NE. */
5204 arg1 = TREE_OPERAND (arg0, 1);
5205 arg0 = TREE_OPERAND (arg0, 0);
5207 /* This requires us to invert the code. */
5208 code = (code == EQ_EXPR ? NE_EXPR : EQ_EXPR);
5211 /* If this is testing a single bit, we can optimize the test. */
5212 if ((code == NE_EXPR || code == EQ_EXPR)
5213 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
5214 && integer_pow2p (TREE_OPERAND (arg0, 1)))
5216 tree inner = TREE_OPERAND (arg0, 0);
5217 tree type = TREE_TYPE (arg0);
5218 int bitnum = tree_log2 (TREE_OPERAND (arg0, 1));
5219 enum machine_mode operand_mode = TYPE_MODE (type);
5221 tree signed_type, unsigned_type, intermediate_type;
5224 /* If we have (A & C) != 0 where C is the sign bit of A, convert
5225 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
5226 arg00 = sign_bit_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
5227 if (arg00 != NULL_TREE)
5229 tree stype = (*lang_hooks.types.signed_type) (TREE_TYPE (arg00));
5230 return fold (build (code == EQ_EXPR ? GE_EXPR : LT_EXPR, result_type,
5231 fold_convert (stype, arg00),
5232 fold_convert (stype, integer_zero_node)));
5235 /* At this point, we know that arg0 is not testing the sign bit. */
5236 if (TYPE_PRECISION (type) - 1 == bitnum)
5239 /* Otherwise we have (A & C) != 0 where C is a single bit,
5240 convert that into ((A >> C2) & 1). Where C2 = log2(C).
5241 Similarly for (A & C) == 0. */
5243 /* If INNER is a right shift of a constant and it plus BITNUM does
5244 not overflow, adjust BITNUM and INNER. */
5245 if (TREE_CODE (inner) == RSHIFT_EXPR
5246 && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST
5247 && TREE_INT_CST_HIGH (TREE_OPERAND (inner, 1)) == 0
5248 && bitnum < TYPE_PRECISION (type)
5249 && 0 > compare_tree_int (TREE_OPERAND (inner, 1),
5250 bitnum - TYPE_PRECISION (type)))
5252 bitnum += TREE_INT_CST_LOW (TREE_OPERAND (inner, 1));
5253 inner = TREE_OPERAND (inner, 0);
5256 /* If we are going to be able to omit the AND below, we must do our
5257 operations as unsigned. If we must use the AND, we have a choice.
5258 Normally unsigned is faster, but for some machines signed is. */
5259 #ifdef LOAD_EXTEND_OP
5260 ops_unsigned = (LOAD_EXTEND_OP (operand_mode) == SIGN_EXTEND ? 0 : 1);
5265 signed_type = (*lang_hooks.types.type_for_mode) (operand_mode, 0);
5266 unsigned_type = (*lang_hooks.types.type_for_mode) (operand_mode, 1);
5267 intermediate_type = ops_unsigned ? unsigned_type : signed_type;
5268 inner = fold_convert (intermediate_type, inner);
5271 inner = build (RSHIFT_EXPR, intermediate_type,
5272 inner, size_int (bitnum));
5274 if (code == EQ_EXPR)
5275 inner = build (BIT_XOR_EXPR, intermediate_type,
5276 inner, integer_one_node);
5278 /* Put the AND last so it can combine with more things. */
5279 inner = build (BIT_AND_EXPR, intermediate_type,
5280 inner, integer_one_node);
5282 /* Make sure to return the proper type. */
5283 inner = fold_convert (result_type, inner);
5290 /* Check whether we are allowed to reorder operands arg0 and arg1,
5291 such that the evaluation of arg1 occurs before arg0. */
5294 reorder_operands_p (tree arg0, tree arg1)
5296 if (! flag_evaluation_order)
5298 if (TREE_CONSTANT (arg0) || TREE_CONSTANT (arg1))
5300 return ! TREE_SIDE_EFFECTS (arg0)
5301 && ! TREE_SIDE_EFFECTS (arg1);
5304 /* Test whether it is preferable two swap two operands, ARG0 and
5305 ARG1, for example because ARG0 is an integer constant and ARG1
5306 isn't. If REORDER is true, only recommend swapping if we can
5307 evaluate the operands in reverse order. */
5310 tree_swap_operands_p (tree arg0, tree arg1, bool reorder)
5312 STRIP_SIGN_NOPS (arg0);
5313 STRIP_SIGN_NOPS (arg1);
5315 if (TREE_CODE (arg1) == INTEGER_CST)
5317 if (TREE_CODE (arg0) == INTEGER_CST)
5320 if (TREE_CODE (arg1) == REAL_CST)
5322 if (TREE_CODE (arg0) == REAL_CST)
5325 if (TREE_CODE (arg1) == COMPLEX_CST)
5327 if (TREE_CODE (arg0) == COMPLEX_CST)
5330 if (TREE_CONSTANT (arg1))
5332 if (TREE_CONSTANT (arg0))
5338 if (reorder && flag_evaluation_order
5339 && (TREE_SIDE_EFFECTS (arg0) || TREE_SIDE_EFFECTS (arg1)))
5350 /* Perform constant folding and related simplification of EXPR.
5351 The related simplifications include x*1 => x, x*0 => 0, etc.,
5352 and application of the associative law.
5353 NOP_EXPR conversions may be removed freely (as long as we
5354 are careful not to change the C type of the overall expression)
5355 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
5356 but we can constant-fold them if they have constant operands. */
5358 #ifdef ENABLE_FOLD_CHECKING
5359 # define fold(x) fold_1 (x)
5360 static tree fold_1 (tree);
5366 tree t = expr, orig_t;
5367 tree t1 = NULL_TREE;
5369 tree type = TREE_TYPE (expr);
5370 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
5371 enum tree_code code = TREE_CODE (t);
5372 int kind = TREE_CODE_CLASS (code);
5374 /* WINS will be nonzero when the switch is done
5375 if all operands are constant. */
5378 /* Don't try to process an RTL_EXPR since its operands aren't trees.
5379 Likewise for a SAVE_EXPR that's already been evaluated. */
5380 if (code == RTL_EXPR || (code == SAVE_EXPR && SAVE_EXPR_RTL (t) != 0))
5383 /* Return right away if a constant. */
5389 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
5393 /* Special case for conversion ops that can have fixed point args. */
5394 arg0 = TREE_OPERAND (t, 0);
5396 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
5398 STRIP_SIGN_NOPS (arg0);
5400 if (arg0 != 0 && TREE_CODE (arg0) == COMPLEX_CST)
5401 subop = TREE_REALPART (arg0);
5405 if (subop != 0 && TREE_CODE (subop) != INTEGER_CST
5406 && TREE_CODE (subop) != REAL_CST)
5407 /* Note that TREE_CONSTANT isn't enough:
5408 static var addresses are constant but we can't
5409 do arithmetic on them. */
5412 else if (IS_EXPR_CODE_CLASS (kind))
5414 int len = first_rtl_op (code);
5416 for (i = 0; i < len; i++)
5418 tree op = TREE_OPERAND (t, i);
5422 continue; /* Valid for CALL_EXPR, at least. */
5424 /* Strip any conversions that don't change the mode. This is
5425 safe for every expression, except for a comparison expression
5426 because its signedness is derived from its operands. So, in
5427 the latter case, only strip conversions that don't change the
5430 Note that this is done as an internal manipulation within the
5431 constant folder, in order to find the simplest representation
5432 of the arguments so that their form can be studied. In any
5433 cases, the appropriate type conversions should be put back in
5434 the tree that will get out of the constant folder. */
5436 STRIP_SIGN_NOPS (op);
5440 if (TREE_CODE (op) == COMPLEX_CST)
5441 subop = TREE_REALPART (op);
5445 if (TREE_CODE (subop) != INTEGER_CST
5446 && TREE_CODE (subop) != REAL_CST)
5447 /* Note that TREE_CONSTANT isn't enough:
5448 static var addresses are constant but we can't
5449 do arithmetic on them. */
5459 /* If this is a commutative operation, and ARG0 is a constant, move it
5460 to ARG1 to reduce the number of tests below. */
5461 if (commutative_tree_code (code)
5462 && tree_swap_operands_p (arg0, arg1, true))
5463 return fold (build (code, type, TREE_OPERAND (t, 1),
5464 TREE_OPERAND (t, 0)));
5466 /* Now WINS is set as described above,
5467 ARG0 is the first operand of EXPR,
5468 and ARG1 is the second operand (if it has more than one operand).
5470 First check for cases where an arithmetic operation is applied to a
5471 compound, conditional, or comparison operation. Push the arithmetic
5472 operation inside the compound or conditional to see if any folding
5473 can then be done. Convert comparison to conditional for this purpose.
5474 The also optimizes non-constant cases that used to be done in
5477 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
5478 one of the operands is a comparison and the other is a comparison, a
5479 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
5480 code below would make the expression more complex. Change it to a
5481 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
5482 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
5484 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
5485 || code == EQ_EXPR || code == NE_EXPR)
5486 && ((truth_value_p (TREE_CODE (arg0))
5487 && (truth_value_p (TREE_CODE (arg1))
5488 || (TREE_CODE (arg1) == BIT_AND_EXPR
5489 && integer_onep (TREE_OPERAND (arg1, 1)))))
5490 || (truth_value_p (TREE_CODE (arg1))
5491 && (truth_value_p (TREE_CODE (arg0))
5492 || (TREE_CODE (arg0) == BIT_AND_EXPR
5493 && integer_onep (TREE_OPERAND (arg0, 1)))))))
5495 t = fold (build (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
5496 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
5500 if (code == EQ_EXPR)
5501 t = invert_truthvalue (t);
5506 if (TREE_CODE_CLASS (code) == '1')
5508 if (TREE_CODE (arg0) == COMPOUND_EXPR)
5509 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5510 fold (build1 (code, type, TREE_OPERAND (arg0, 1))));
5511 else if (TREE_CODE (arg0) == COND_EXPR)
5513 tree arg01 = TREE_OPERAND (arg0, 1);
5514 tree arg02 = TREE_OPERAND (arg0, 2);
5515 if (! VOID_TYPE_P (TREE_TYPE (arg01)))
5516 arg01 = fold (build1 (code, type, arg01));
5517 if (! VOID_TYPE_P (TREE_TYPE (arg02)))
5518 arg02 = fold (build1 (code, type, arg02));
5519 t = fold (build (COND_EXPR, type, TREE_OPERAND (arg0, 0),
5522 /* If this was a conversion, and all we did was to move into
5523 inside the COND_EXPR, bring it back out. But leave it if
5524 it is a conversion from integer to integer and the
5525 result precision is no wider than a word since such a
5526 conversion is cheap and may be optimized away by combine,
5527 while it couldn't if it were outside the COND_EXPR. Then return
5528 so we don't get into an infinite recursion loop taking the
5529 conversion out and then back in. */
5531 if ((code == NOP_EXPR || code == CONVERT_EXPR
5532 || code == NON_LVALUE_EXPR)
5533 && TREE_CODE (t) == COND_EXPR
5534 && TREE_CODE (TREE_OPERAND (t, 1)) == code
5535 && TREE_CODE (TREE_OPERAND (t, 2)) == code
5536 && ! VOID_TYPE_P (TREE_OPERAND (t, 1))
5537 && ! VOID_TYPE_P (TREE_OPERAND (t, 2))
5538 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))
5539 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 2), 0)))
5540 && ! (INTEGRAL_TYPE_P (TREE_TYPE (t))
5542 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))))
5543 && TYPE_PRECISION (TREE_TYPE (t)) <= BITS_PER_WORD))
5544 t = build1 (code, type,
5546 TREE_TYPE (TREE_OPERAND
5547 (TREE_OPERAND (t, 1), 0)),
5548 TREE_OPERAND (t, 0),
5549 TREE_OPERAND (TREE_OPERAND (t, 1), 0),
5550 TREE_OPERAND (TREE_OPERAND (t, 2), 0)));
5553 else if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<')
5554 return fold (build (COND_EXPR, type, arg0,
5555 fold (build1 (code, type, integer_one_node)),
5556 fold (build1 (code, type, integer_zero_node))));
5558 else if (TREE_CODE_CLASS (code) == '<'
5559 && TREE_CODE (arg0) == COMPOUND_EXPR)
5560 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5561 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
5562 else if (TREE_CODE_CLASS (code) == '<'
5563 && TREE_CODE (arg1) == COMPOUND_EXPR)
5564 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
5565 fold (build (code, type, arg0, TREE_OPERAND (arg1, 1))));
5566 else if (TREE_CODE_CLASS (code) == '2'
5567 || TREE_CODE_CLASS (code) == '<')
5569 if (TREE_CODE (arg1) == COMPOUND_EXPR
5570 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg1, 0))
5571 && ! TREE_SIDE_EFFECTS (arg0))
5572 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
5573 fold (build (code, type,
5574 arg0, TREE_OPERAND (arg1, 1))));
5575 else if ((TREE_CODE (arg1) == COND_EXPR
5576 || (TREE_CODE_CLASS (TREE_CODE (arg1)) == '<'
5577 && TREE_CODE_CLASS (code) != '<'))
5578 && (TREE_CODE (arg0) != COND_EXPR
5579 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
5580 && (! TREE_SIDE_EFFECTS (arg0)
5581 || ((*lang_hooks.decls.global_bindings_p) () == 0
5582 && ! CONTAINS_PLACEHOLDER_P (arg0))))
5584 fold_binary_op_with_conditional_arg (code, type, arg1, arg0,
5585 /*cond_first_p=*/0);
5586 else if (TREE_CODE (arg0) == COMPOUND_EXPR)
5587 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5588 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
5589 else if ((TREE_CODE (arg0) == COND_EXPR
5590 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
5591 && TREE_CODE_CLASS (code) != '<'))
5592 && (TREE_CODE (arg1) != COND_EXPR
5593 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
5594 && (! TREE_SIDE_EFFECTS (arg1)
5595 || ((*lang_hooks.decls.global_bindings_p) () == 0
5596 && ! CONTAINS_PLACEHOLDER_P (arg1))))
5598 fold_binary_op_with_conditional_arg (code, type, arg0, arg1,
5599 /*cond_first_p=*/1);
5613 return fold (DECL_INITIAL (t));
5618 case FIX_TRUNC_EXPR:
5620 case FIX_FLOOR_EXPR:
5621 if (TREE_TYPE (TREE_OPERAND (t, 0)) == TREE_TYPE (t))
5622 return TREE_OPERAND (t, 0);
5624 /* Handle cases of two conversions in a row. */
5625 if (TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
5626 || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR)
5628 tree inside_type = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5629 tree inter_type = TREE_TYPE (TREE_OPERAND (t, 0));
5630 tree final_type = TREE_TYPE (t);
5631 int inside_int = INTEGRAL_TYPE_P (inside_type);
5632 int inside_ptr = POINTER_TYPE_P (inside_type);
5633 int inside_float = FLOAT_TYPE_P (inside_type);
5634 unsigned int inside_prec = TYPE_PRECISION (inside_type);
5635 int inside_unsignedp = TREE_UNSIGNED (inside_type);
5636 int inter_int = INTEGRAL_TYPE_P (inter_type);
5637 int inter_ptr = POINTER_TYPE_P (inter_type);
5638 int inter_float = FLOAT_TYPE_P (inter_type);
5639 unsigned int inter_prec = TYPE_PRECISION (inter_type);
5640 int inter_unsignedp = TREE_UNSIGNED (inter_type);
5641 int final_int = INTEGRAL_TYPE_P (final_type);
5642 int final_ptr = POINTER_TYPE_P (final_type);
5643 int final_float = FLOAT_TYPE_P (final_type);
5644 unsigned int final_prec = TYPE_PRECISION (final_type);
5645 int final_unsignedp = TREE_UNSIGNED (final_type);
5647 /* In addition to the cases of two conversions in a row
5648 handled below, if we are converting something to its own
5649 type via an object of identical or wider precision, neither
5650 conversion is needed. */
5651 if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (final_type)
5652 && ((inter_int && final_int) || (inter_float && final_float))
5653 && inter_prec >= final_prec)
5654 return fold (build1 (code, final_type,
5655 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
5657 /* Likewise, if the intermediate and final types are either both
5658 float or both integer, we don't need the middle conversion if
5659 it is wider than the final type and doesn't change the signedness
5660 (for integers). Avoid this if the final type is a pointer
5661 since then we sometimes need the inner conversion. Likewise if
5662 the outer has a precision not equal to the size of its mode. */
5663 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
5664 || (inter_float && inside_float))
5665 && inter_prec >= inside_prec
5666 && (inter_float || inter_unsignedp == inside_unsignedp)
5667 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
5668 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
5670 return fold (build1 (code, final_type,
5671 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
5673 /* If we have a sign-extension of a zero-extended value, we can
5674 replace that by a single zero-extension. */
5675 if (inside_int && inter_int && final_int
5676 && inside_prec < inter_prec && inter_prec < final_prec
5677 && inside_unsignedp && !inter_unsignedp)
5678 return fold (build1 (code, final_type,
5679 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
5681 /* Two conversions in a row are not needed unless:
5682 - some conversion is floating-point (overstrict for now), or
5683 - the intermediate type is narrower than both initial and
5685 - the intermediate type and innermost type differ in signedness,
5686 and the outermost type is wider than the intermediate, or
5687 - the initial type is a pointer type and the precisions of the
5688 intermediate and final types differ, or
5689 - the final type is a pointer type and the precisions of the
5690 initial and intermediate types differ. */
5691 if (! inside_float && ! inter_float && ! final_float
5692 && (inter_prec > inside_prec || inter_prec > final_prec)
5693 && ! (inside_int && inter_int
5694 && inter_unsignedp != inside_unsignedp
5695 && inter_prec < final_prec)
5696 && ((inter_unsignedp && inter_prec > inside_prec)
5697 == (final_unsignedp && final_prec > inter_prec))
5698 && ! (inside_ptr && inter_prec != final_prec)
5699 && ! (final_ptr && inside_prec != inter_prec)
5700 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
5701 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
5703 return fold (build1 (code, final_type,
5704 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
5707 if (TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR
5708 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t, 0), 1))
5709 /* Detect assigning a bitfield. */
5710 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) == COMPONENT_REF
5711 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 1))))
5713 /* Don't leave an assignment inside a conversion
5714 unless assigning a bitfield. */
5715 tree prev = TREE_OPERAND (t, 0);
5718 TREE_OPERAND (t, 0) = TREE_OPERAND (prev, 1);
5719 /* First do the assignment, then return converted constant. */
5720 t = build (COMPOUND_EXPR, TREE_TYPE (t), prev, fold (t));
5725 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
5726 constants (if x has signed type, the sign bit cannot be set
5727 in c). This folds extension into the BIT_AND_EXPR. */
5728 if (INTEGRAL_TYPE_P (TREE_TYPE (t))
5729 && TREE_CODE (TREE_TYPE (t)) != BOOLEAN_TYPE
5730 && TREE_CODE (TREE_OPERAND (t, 0)) == BIT_AND_EXPR
5731 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 1)) == INTEGER_CST)
5733 tree and = TREE_OPERAND (t, 0);
5734 tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
5737 if (TREE_UNSIGNED (TREE_TYPE (and))
5738 || (TYPE_PRECISION (TREE_TYPE (t))
5739 <= TYPE_PRECISION (TREE_TYPE (and))))
5741 else if (TYPE_PRECISION (TREE_TYPE (and1))
5742 <= HOST_BITS_PER_WIDE_INT
5743 && host_integerp (and1, 1))
5745 unsigned HOST_WIDE_INT cst;
5747 cst = tree_low_cst (and1, 1);
5748 cst &= (HOST_WIDE_INT) -1
5749 << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
5750 change = (cst == 0);
5751 #ifdef LOAD_EXTEND_OP
5753 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
5756 tree uns = (*lang_hooks.types.unsigned_type) (TREE_TYPE (and0));
5757 and0 = fold_convert (uns, and0);
5758 and1 = fold_convert (uns, and1);
5763 return fold (build (BIT_AND_EXPR, TREE_TYPE (t),
5764 fold_convert (TREE_TYPE (t), and0),
5765 fold_convert (TREE_TYPE (t), and1)));
5768 tem = fold_convert_const (code, TREE_TYPE (t), arg0);
5769 return tem ? tem : t;
5771 case VIEW_CONVERT_EXPR:
5772 if (TREE_CODE (TREE_OPERAND (t, 0)) == VIEW_CONVERT_EXPR)
5773 return build1 (VIEW_CONVERT_EXPR, type,
5774 TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5778 if (TREE_CODE (arg0) == CONSTRUCTOR
5779 && ! type_contains_placeholder_p (TREE_TYPE (arg0)))
5781 tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0));
5788 if (TREE_CONSTANT (t) != wins)
5792 TREE_CONSTANT (t) = wins;
5797 if (negate_expr_p (arg0))
5798 return fold_convert (type, negate_expr (arg0));
5804 if (TREE_CODE (arg0) == INTEGER_CST)
5806 /* If the value is unsigned, then the absolute value is
5807 the same as the ordinary value. */
5808 if (TREE_UNSIGNED (type))
5810 /* Similarly, if the value is non-negative. */
5811 else if (INT_CST_LT (integer_minus_one_node, arg0))
5813 /* If the value is negative, then the absolute value is
5817 unsigned HOST_WIDE_INT low;
5819 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
5820 TREE_INT_CST_HIGH (arg0),
5822 t = build_int_2 (low, high);
5823 TREE_TYPE (t) = type;
5825 = (TREE_OVERFLOW (arg0)
5826 | force_fit_type (t, overflow));
5827 TREE_CONSTANT_OVERFLOW (t)
5828 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
5831 else if (TREE_CODE (arg0) == REAL_CST)
5833 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
5834 t = build_real (type,
5835 REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
5838 else if (TREE_CODE (arg0) == NEGATE_EXPR)
5839 return fold (build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0)));
5840 /* Convert fabs((double)float) into (double)fabsf(float). */
5841 else if (TREE_CODE (arg0) == NOP_EXPR
5842 && TREE_CODE (type) == REAL_TYPE)
5844 tree targ0 = strip_float_extensions (arg0);
5846 return fold_convert (type, fold (build1 (ABS_EXPR,
5850 else if (tree_expr_nonnegative_p (arg0))
5855 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
5856 return fold_convert (type, arg0);
5857 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
5858 return build (COMPLEX_EXPR, type,
5859 TREE_OPERAND (arg0, 0),
5860 negate_expr (TREE_OPERAND (arg0, 1)));
5861 else if (TREE_CODE (arg0) == COMPLEX_CST)
5862 return build_complex (type, TREE_REALPART (arg0),
5863 negate_expr (TREE_IMAGPART (arg0)));
5864 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
5865 return fold (build (TREE_CODE (arg0), type,
5866 fold (build1 (CONJ_EXPR, type,
5867 TREE_OPERAND (arg0, 0))),
5868 fold (build1 (CONJ_EXPR,
5869 type, TREE_OPERAND (arg0, 1)))));
5870 else if (TREE_CODE (arg0) == CONJ_EXPR)
5871 return TREE_OPERAND (arg0, 0);
5877 t = build_int_2 (~ TREE_INT_CST_LOW (arg0),
5878 ~ TREE_INT_CST_HIGH (arg0));
5879 TREE_TYPE (t) = type;
5880 force_fit_type (t, 0);
5881 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg0);
5882 TREE_CONSTANT_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (arg0);
5884 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
5885 return TREE_OPERAND (arg0, 0);
5889 /* A + (-B) -> A - B */
5890 if (TREE_CODE (arg1) == NEGATE_EXPR)
5891 return fold (build (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5892 /* (-A) + B -> B - A */
5893 if (TREE_CODE (arg0) == NEGATE_EXPR)
5894 return fold (build (MINUS_EXPR, type, arg1, TREE_OPERAND (arg0, 0)));
5895 else if (! FLOAT_TYPE_P (type))
5897 if (integer_zerop (arg1))
5898 return non_lvalue (fold_convert (type, arg0));
5900 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
5901 with a constant, and the two constants have no bits in common,
5902 we should treat this as a BIT_IOR_EXPR since this may produce more
5904 if (TREE_CODE (arg0) == BIT_AND_EXPR
5905 && TREE_CODE (arg1) == BIT_AND_EXPR
5906 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5907 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
5908 && integer_zerop (const_binop (BIT_AND_EXPR,
5909 TREE_OPERAND (arg0, 1),
5910 TREE_OPERAND (arg1, 1), 0)))
5912 code = BIT_IOR_EXPR;
5916 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
5917 (plus (plus (mult) (mult)) (foo)) so that we can
5918 take advantage of the factoring cases below. */
5919 if ((TREE_CODE (arg0) == PLUS_EXPR
5920 && TREE_CODE (arg1) == MULT_EXPR)
5921 || (TREE_CODE (arg1) == PLUS_EXPR
5922 && TREE_CODE (arg0) == MULT_EXPR))
5924 tree parg0, parg1, parg, marg;
5926 if (TREE_CODE (arg0) == PLUS_EXPR)
5927 parg = arg0, marg = arg1;
5929 parg = arg1, marg = arg0;
5930 parg0 = TREE_OPERAND (parg, 0);
5931 parg1 = TREE_OPERAND (parg, 1);
5935 if (TREE_CODE (parg0) == MULT_EXPR
5936 && TREE_CODE (parg1) != MULT_EXPR)
5937 return fold (build (PLUS_EXPR, type,
5938 fold (build (PLUS_EXPR, type,
5939 fold_convert (type, parg0),
5940 fold_convert (type, marg))),
5941 fold_convert (type, parg1)));
5942 if (TREE_CODE (parg0) != MULT_EXPR
5943 && TREE_CODE (parg1) == MULT_EXPR)
5944 return fold (build (PLUS_EXPR, type,
5945 fold (build (PLUS_EXPR, type,
5946 fold_convert (type, parg1),
5947 fold_convert (type, marg))),
5948 fold_convert (type, parg0)));
5951 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR)
5953 tree arg00, arg01, arg10, arg11;
5954 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
5956 /* (A * C) + (B * C) -> (A+B) * C.
5957 We are most concerned about the case where C is a constant,
5958 but other combinations show up during loop reduction. Since
5959 it is not difficult, try all four possibilities. */
5961 arg00 = TREE_OPERAND (arg0, 0);
5962 arg01 = TREE_OPERAND (arg0, 1);
5963 arg10 = TREE_OPERAND (arg1, 0);
5964 arg11 = TREE_OPERAND (arg1, 1);
5967 if (operand_equal_p (arg01, arg11, 0))
5968 same = arg01, alt0 = arg00, alt1 = arg10;
5969 else if (operand_equal_p (arg00, arg10, 0))
5970 same = arg00, alt0 = arg01, alt1 = arg11;
5971 else if (operand_equal_p (arg00, arg11, 0))
5972 same = arg00, alt0 = arg01, alt1 = arg10;
5973 else if (operand_equal_p (arg01, arg10, 0))
5974 same = arg01, alt0 = arg00, alt1 = arg11;
5976 /* No identical multiplicands; see if we can find a common
5977 power-of-two factor in non-power-of-two multiplies. This
5978 can help in multi-dimensional array access. */
5979 else if (TREE_CODE (arg01) == INTEGER_CST
5980 && TREE_CODE (arg11) == INTEGER_CST
5981 && TREE_INT_CST_HIGH (arg01) == 0
5982 && TREE_INT_CST_HIGH (arg11) == 0)
5984 HOST_WIDE_INT int01, int11, tmp;
5985 int01 = TREE_INT_CST_LOW (arg01);
5986 int11 = TREE_INT_CST_LOW (arg11);
5988 /* Move min of absolute values to int11. */
5989 if ((int01 >= 0 ? int01 : -int01)
5990 < (int11 >= 0 ? int11 : -int11))
5992 tmp = int01, int01 = int11, int11 = tmp;
5993 alt0 = arg00, arg00 = arg10, arg10 = alt0;
5994 alt0 = arg01, arg01 = arg11, arg11 = alt0;
5997 if (exact_log2 (int11) > 0 && int01 % int11 == 0)
5999 alt0 = fold (build (MULT_EXPR, type, arg00,
6000 build_int_2 (int01 / int11, 0)));
6007 return fold (build (MULT_EXPR, type,
6008 fold (build (PLUS_EXPR, type, alt0, alt1)),
6014 /* See if ARG1 is zero and X + ARG1 reduces to X. */
6015 if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
6016 return non_lvalue (fold_convert (type, arg0));
6018 /* Likewise if the operands are reversed. */
6019 if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
6020 return non_lvalue (fold_convert (type, arg1));
6022 /* Convert x+x into x*2.0. */
6023 if (operand_equal_p (arg0, arg1, 0)
6024 && SCALAR_FLOAT_TYPE_P (type))
6025 return fold (build (MULT_EXPR, type, arg0,
6026 build_real (type, dconst2)));
6028 /* Convert x*c+x into x*(c+1). */
6029 if (flag_unsafe_math_optimizations
6030 && TREE_CODE (arg0) == MULT_EXPR
6031 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
6032 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0, 1))
6033 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
6037 c = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
6038 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
6039 return fold (build (MULT_EXPR, type, arg1,
6040 build_real (type, c)));
6043 /* Convert x+x*c into x*(c+1). */
6044 if (flag_unsafe_math_optimizations
6045 && TREE_CODE (arg1) == MULT_EXPR
6046 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST
6047 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1, 1))
6048 && operand_equal_p (TREE_OPERAND (arg1, 0), arg0, 0))
6052 c = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
6053 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
6054 return fold (build (MULT_EXPR, type, arg0,
6055 build_real (type, c)));
6058 /* Convert x*c1+x*c2 into x*(c1+c2). */
6059 if (flag_unsafe_math_optimizations
6060 && TREE_CODE (arg0) == MULT_EXPR
6061 && TREE_CODE (arg1) == MULT_EXPR
6062 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
6063 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0, 1))
6064 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST
6065 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1, 1))
6066 && operand_equal_p (TREE_OPERAND (arg0, 0),
6067 TREE_OPERAND (arg1, 0), 0))
6069 REAL_VALUE_TYPE c1, c2;
6071 c1 = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
6072 c2 = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
6073 real_arithmetic (&c1, PLUS_EXPR, &c1, &c2);
6074 return fold (build (MULT_EXPR, type,
6075 TREE_OPERAND (arg0, 0),
6076 build_real (type, c1)));
6081 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
6082 is a rotate of A by C1 bits. */
6083 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
6084 is a rotate of A by B bits. */
6086 enum tree_code code0, code1;
6087 code0 = TREE_CODE (arg0);
6088 code1 = TREE_CODE (arg1);
6089 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
6090 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
6091 && operand_equal_p (TREE_OPERAND (arg0, 0),
6092 TREE_OPERAND (arg1, 0), 0)
6093 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
6095 tree tree01, tree11;
6096 enum tree_code code01, code11;
6098 tree01 = TREE_OPERAND (arg0, 1);
6099 tree11 = TREE_OPERAND (arg1, 1);
6100 STRIP_NOPS (tree01);
6101 STRIP_NOPS (tree11);
6102 code01 = TREE_CODE (tree01);
6103 code11 = TREE_CODE (tree11);
6104 if (code01 == INTEGER_CST
6105 && code11 == INTEGER_CST
6106 && TREE_INT_CST_HIGH (tree01) == 0
6107 && TREE_INT_CST_HIGH (tree11) == 0
6108 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
6109 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
6110 return build (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
6111 code0 == LSHIFT_EXPR ? tree01 : tree11);
6112 else if (code11 == MINUS_EXPR)
6114 tree tree110, tree111;
6115 tree110 = TREE_OPERAND (tree11, 0);
6116 tree111 = TREE_OPERAND (tree11, 1);
6117 STRIP_NOPS (tree110);
6118 STRIP_NOPS (tree111);
6119 if (TREE_CODE (tree110) == INTEGER_CST
6120 && 0 == compare_tree_int (tree110,
6122 (TREE_TYPE (TREE_OPERAND
6124 && operand_equal_p (tree01, tree111, 0))
6125 return build ((code0 == LSHIFT_EXPR
6128 type, TREE_OPERAND (arg0, 0), tree01);
6130 else if (code01 == MINUS_EXPR)
6132 tree tree010, tree011;
6133 tree010 = TREE_OPERAND (tree01, 0);
6134 tree011 = TREE_OPERAND (tree01, 1);
6135 STRIP_NOPS (tree010);
6136 STRIP_NOPS (tree011);
6137 if (TREE_CODE (tree010) == INTEGER_CST
6138 && 0 == compare_tree_int (tree010,
6140 (TREE_TYPE (TREE_OPERAND
6142 && operand_equal_p (tree11, tree011, 0))
6143 return build ((code0 != LSHIFT_EXPR
6146 type, TREE_OPERAND (arg0, 0), tree11);
6152 /* In most languages, can't associate operations on floats through
6153 parentheses. Rather than remember where the parentheses were, we
6154 don't associate floats at all, unless the user has specified
6155 -funsafe-math-optimizations. */
6158 && (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
6160 tree var0, con0, lit0, minus_lit0;
6161 tree var1, con1, lit1, minus_lit1;
6163 /* Split both trees into variables, constants, and literals. Then
6164 associate each group together, the constants with literals,
6165 then the result with variables. This increases the chances of
6166 literals being recombined later and of generating relocatable
6167 expressions for the sum of a constant and literal. */
6168 var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
6169 var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
6170 code == MINUS_EXPR);
6172 /* Only do something if we found more than two objects. Otherwise,
6173 nothing has changed and we risk infinite recursion. */
6174 if (2 < ((var0 != 0) + (var1 != 0)
6175 + (con0 != 0) + (con1 != 0)
6176 + (lit0 != 0) + (lit1 != 0)
6177 + (minus_lit0 != 0) + (minus_lit1 != 0)))
6179 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
6180 if (code == MINUS_EXPR)
6183 var0 = associate_trees (var0, var1, code, type);
6184 con0 = associate_trees (con0, con1, code, type);
6185 lit0 = associate_trees (lit0, lit1, code, type);
6186 minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
6188 /* Preserve the MINUS_EXPR if the negative part of the literal is
6189 greater than the positive part. Otherwise, the multiplicative
6190 folding code (i.e extract_muldiv) may be fooled in case
6191 unsigned constants are subtracted, like in the following
6192 example: ((X*2 + 4) - 8U)/2. */
6193 if (minus_lit0 && lit0)
6195 if (TREE_CODE (lit0) == INTEGER_CST
6196 && TREE_CODE (minus_lit0) == INTEGER_CST
6197 && tree_int_cst_lt (lit0, minus_lit0))
6199 minus_lit0 = associate_trees (minus_lit0, lit0,
6205 lit0 = associate_trees (lit0, minus_lit0,
6213 return fold_convert (type,
6214 associate_trees (var0, minus_lit0,
6218 con0 = associate_trees (con0, minus_lit0,
6220 return fold_convert (type,
6221 associate_trees (var0, con0,
6226 con0 = associate_trees (con0, lit0, code, type);
6227 return fold_convert (type, associate_trees (var0, con0,
6234 t1 = const_binop (code, arg0, arg1, 0);
6235 if (t1 != NULL_TREE)
6237 /* The return value should always have
6238 the same type as the original expression. */
6239 if (TREE_TYPE (t1) != TREE_TYPE (t))
6240 t1 = fold_convert (TREE_TYPE (t), t1);
6247 /* A - (-B) -> A + B */
6248 if (TREE_CODE (arg1) == NEGATE_EXPR)
6249 return fold (build (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
6250 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
6251 if (TREE_CODE (arg0) == NEGATE_EXPR
6252 && (FLOAT_TYPE_P (type)
6253 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv))
6254 && negate_expr_p (arg1)
6255 && reorder_operands_p (arg0, arg1))
6256 return fold (build (MINUS_EXPR, type, negate_expr (arg1),
6257 TREE_OPERAND (arg0, 0)));
6259 if (! FLOAT_TYPE_P (type))
6261 if (! wins && integer_zerop (arg0))
6262 return negate_expr (fold_convert (type, arg1));
6263 if (integer_zerop (arg1))
6264 return non_lvalue (fold_convert (type, arg0));
6266 /* Fold A - (A & B) into ~B & A. */
6267 if (!TREE_SIDE_EFFECTS (arg0)
6268 && TREE_CODE (arg1) == BIT_AND_EXPR)
6270 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
6271 return fold (build (BIT_AND_EXPR, type,
6272 fold (build1 (BIT_NOT_EXPR, type,
6273 TREE_OPERAND (arg1, 0))),
6275 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
6276 return fold (build (BIT_AND_EXPR, type,
6277 fold (build1 (BIT_NOT_EXPR, type,
6278 TREE_OPERAND (arg1, 1))),
6282 /* Fold (A & ~B) - (A & B) into (A ^ B) - B, where B is
6283 any power of 2 minus 1. */
6284 if (TREE_CODE (arg0) == BIT_AND_EXPR
6285 && TREE_CODE (arg1) == BIT_AND_EXPR
6286 && operand_equal_p (TREE_OPERAND (arg0, 0),
6287 TREE_OPERAND (arg1, 0), 0))
6289 tree mask0 = TREE_OPERAND (arg0, 1);
6290 tree mask1 = TREE_OPERAND (arg1, 1);
6291 tree tem = fold (build1 (BIT_NOT_EXPR, type, mask0));
6293 if (operand_equal_p (tem, mask1, 0))
6295 tem = fold (build (BIT_XOR_EXPR, type,
6296 TREE_OPERAND (arg0, 0), mask1));
6297 return fold (build (MINUS_EXPR, type, tem, mask1));
6302 /* See if ARG1 is zero and X - ARG1 reduces to X. */
6303 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
6304 return non_lvalue (fold_convert (type, arg0));
6306 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
6307 ARG0 is zero and X + ARG0 reduces to X, since that would mean
6308 (-ARG1 + ARG0) reduces to -ARG1. */
6309 else if (!wins && fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
6310 return negate_expr (fold_convert (type, arg1));
6312 /* Fold &x - &x. This can happen from &x.foo - &x.
6313 This is unsafe for certain floats even in non-IEEE formats.
6314 In IEEE, it is unsafe because it does wrong for NaNs.
6315 Also note that operand_equal_p is always false if an operand
6318 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
6319 && operand_equal_p (arg0, arg1, 0))
6320 return fold_convert (type, integer_zero_node);
6322 /* A - B -> A + (-B) if B is easily negatable. */
6323 if (!wins && negate_expr_p (arg1)
6324 && (FLOAT_TYPE_P (type)
6325 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv)))
6326 return fold (build (PLUS_EXPR, type, arg0, negate_expr (arg1)));
6328 if (TREE_CODE (arg0) == MULT_EXPR
6329 && TREE_CODE (arg1) == MULT_EXPR
6330 && (INTEGRAL_TYPE_P (type) || flag_unsafe_math_optimizations))
6332 /* (A * C) - (B * C) -> (A-B) * C. */
6333 if (operand_equal_p (TREE_OPERAND (arg0, 1),
6334 TREE_OPERAND (arg1, 1), 0))
6335 return fold (build (MULT_EXPR, type,
6336 fold (build (MINUS_EXPR, type,
6337 TREE_OPERAND (arg0, 0),
6338 TREE_OPERAND (arg1, 0))),
6339 TREE_OPERAND (arg0, 1)));
6340 /* (A * C1) - (A * C2) -> A * (C1-C2). */
6341 if (operand_equal_p (TREE_OPERAND (arg0, 0),
6342 TREE_OPERAND (arg1, 0), 0))
6343 return fold (build (MULT_EXPR, type,
6344 TREE_OPERAND (arg0, 0),
6345 fold (build (MINUS_EXPR, type,
6346 TREE_OPERAND (arg0, 1),
6347 TREE_OPERAND (arg1, 1)))));
6353 /* (-A) * (-B) -> A * B */
6354 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
6355 return fold (build (MULT_EXPR, type,
6356 TREE_OPERAND (arg0, 0),
6357 negate_expr (arg1)));
6358 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
6359 return fold (build (MULT_EXPR, type,
6361 TREE_OPERAND (arg1, 0)));
6363 if (! FLOAT_TYPE_P (type))
6365 if (integer_zerop (arg1))
6366 return omit_one_operand (type, arg1, arg0);
6367 if (integer_onep (arg1))
6368 return non_lvalue (fold_convert (type, arg0));
6370 /* (a * (1 << b)) is (a << b) */
6371 if (TREE_CODE (arg1) == LSHIFT_EXPR
6372 && integer_onep (TREE_OPERAND (arg1, 0)))
6373 return fold (build (LSHIFT_EXPR, type, arg0,
6374 TREE_OPERAND (arg1, 1)));
6375 if (TREE_CODE (arg0) == LSHIFT_EXPR
6376 && integer_onep (TREE_OPERAND (arg0, 0)))
6377 return fold (build (LSHIFT_EXPR, type, arg1,
6378 TREE_OPERAND (arg0, 1)));
6380 if (TREE_CODE (arg1) == INTEGER_CST
6381 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0),
6382 fold_convert (type, arg1),
6384 return fold_convert (type, tem);
6389 /* Maybe fold x * 0 to 0. The expressions aren't the same
6390 when x is NaN, since x * 0 is also NaN. Nor are they the
6391 same in modes with signed zeros, since multiplying a
6392 negative value by 0 gives -0, not +0. */
6393 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
6394 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
6395 && real_zerop (arg1))
6396 return omit_one_operand (type, arg1, arg0);
6397 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
6398 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
6399 && real_onep (arg1))
6400 return non_lvalue (fold_convert (type, arg0));
6402 /* Transform x * -1.0 into -x. */
6403 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
6404 && real_minus_onep (arg1))
6405 return fold (build1 (NEGATE_EXPR, type, arg0));
6407 /* Convert (C1/X)*C2 into (C1*C2)/X. */
6408 if (flag_unsafe_math_optimizations
6409 && TREE_CODE (arg0) == RDIV_EXPR
6410 && TREE_CODE (arg1) == REAL_CST
6411 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST)
6413 tree tem = const_binop (MULT_EXPR, TREE_OPERAND (arg0, 0),
6416 return fold (build (RDIV_EXPR, type, tem,
6417 TREE_OPERAND (arg0, 1)));
6420 if (flag_unsafe_math_optimizations)
6422 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
6423 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
6425 /* Optimizations of sqrt(...)*sqrt(...). */
6426 if (fcode0 == fcode1 && BUILTIN_SQRT_P (fcode0))
6428 tree sqrtfn, arg, arglist;
6429 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
6430 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
6432 /* Optimize sqrt(x)*sqrt(x) as x. */
6433 if (operand_equal_p (arg00, arg10, 0)
6434 && ! HONOR_SNANS (TYPE_MODE (type)))
6437 /* Optimize sqrt(x)*sqrt(y) as sqrt(x*y). */
6438 sqrtfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
6439 arg = fold (build (MULT_EXPR, type, arg00, arg10));
6440 arglist = build_tree_list (NULL_TREE, arg);
6441 return build_function_call_expr (sqrtfn, arglist);
6444 /* Optimize expN(x)*expN(y) as expN(x+y). */
6445 if (fcode0 == fcode1 && BUILTIN_EXPONENT_P (fcode0))
6447 tree expfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
6448 tree arg = build (PLUS_EXPR, type,
6449 TREE_VALUE (TREE_OPERAND (arg0, 1)),
6450 TREE_VALUE (TREE_OPERAND (arg1, 1)));
6451 tree arglist = build_tree_list (NULL_TREE, fold (arg));
6452 return build_function_call_expr (expfn, arglist);
6455 /* Optimizations of pow(...)*pow(...). */
6456 if ((fcode0 == BUILT_IN_POW && fcode1 == BUILT_IN_POW)
6457 || (fcode0 == BUILT_IN_POWF && fcode1 == BUILT_IN_POWF)
6458 || (fcode0 == BUILT_IN_POWL && fcode1 == BUILT_IN_POWL))
6460 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
6461 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
6463 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
6464 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
6467 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
6468 if (operand_equal_p (arg01, arg11, 0))
6470 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
6471 tree arg = build (MULT_EXPR, type, arg00, arg10);
6472 tree arglist = tree_cons (NULL_TREE, fold (arg),
6473 build_tree_list (NULL_TREE,
6475 return build_function_call_expr (powfn, arglist);
6478 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
6479 if (operand_equal_p (arg00, arg10, 0))
6481 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
6482 tree arg = fold (build (PLUS_EXPR, type, arg01, arg11));
6483 tree arglist = tree_cons (NULL_TREE, arg00,
6484 build_tree_list (NULL_TREE,
6486 return build_function_call_expr (powfn, arglist);
6490 /* Optimize tan(x)*cos(x) as sin(x). */
6491 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_COS)
6492 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_COSF)
6493 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_COSL)
6494 || (fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_TAN)
6495 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_TANF)
6496 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_TANL))
6497 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
6498 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
6506 sinfn = implicit_built_in_decls[BUILT_IN_SIN];
6510 sinfn = implicit_built_in_decls[BUILT_IN_SINF];
6514 sinfn = implicit_built_in_decls[BUILT_IN_SINL];
6520 if (sinfn != NULL_TREE)
6521 return build_function_call_expr (sinfn,
6522 TREE_OPERAND (arg0, 1));
6525 /* Optimize x*pow(x,c) as pow(x,c+1). */
6526 if (fcode1 == BUILT_IN_POW
6527 || fcode1 == BUILT_IN_POWF
6528 || fcode1 == BUILT_IN_POWL)
6530 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
6531 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
6533 if (TREE_CODE (arg11) == REAL_CST
6534 && ! TREE_CONSTANT_OVERFLOW (arg11)
6535 && operand_equal_p (arg0, arg10, 0))
6537 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
6541 c = TREE_REAL_CST (arg11);
6542 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
6543 arg = build_real (type, c);
6544 arglist = build_tree_list (NULL_TREE, arg);
6545 arglist = tree_cons (NULL_TREE, arg0, arglist);
6546 return build_function_call_expr (powfn, arglist);
6550 /* Optimize pow(x,c)*x as pow(x,c+1). */
6551 if (fcode0 == BUILT_IN_POW
6552 || fcode0 == BUILT_IN_POWF
6553 || fcode0 == BUILT_IN_POWL)
6555 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
6556 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
6558 if (TREE_CODE (arg01) == REAL_CST
6559 && ! TREE_CONSTANT_OVERFLOW (arg01)
6560 && operand_equal_p (arg1, arg00, 0))
6562 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
6566 c = TREE_REAL_CST (arg01);
6567 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
6568 arg = build_real (type, c);
6569 arglist = build_tree_list (NULL_TREE, arg);
6570 arglist = tree_cons (NULL_TREE, arg1, arglist);
6571 return build_function_call_expr (powfn, arglist);
6575 /* Optimize x*x as pow(x,2.0), which is expanded as x*x. */
6577 && operand_equal_p (arg0, arg1, 0))
6581 if (type == double_type_node)
6582 powfn = implicit_built_in_decls[BUILT_IN_POW];
6583 else if (type == float_type_node)
6584 powfn = implicit_built_in_decls[BUILT_IN_POWF];
6585 else if (type == long_double_type_node)
6586 powfn = implicit_built_in_decls[BUILT_IN_POWL];
6592 tree arg = build_real (type, dconst2);
6593 tree arglist = build_tree_list (NULL_TREE, arg);
6594 arglist = tree_cons (NULL_TREE, arg0, arglist);
6595 return build_function_call_expr (powfn, arglist);
6604 if (integer_all_onesp (arg1))
6605 return omit_one_operand (type, arg1, arg0);
6606 if (integer_zerop (arg1))
6607 return non_lvalue (fold_convert (type, arg0));
6608 t1 = distribute_bit_expr (code, type, arg0, arg1);
6609 if (t1 != NULL_TREE)
6612 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
6614 This results in more efficient code for machines without a NAND
6615 instruction. Combine will canonicalize to the first form
6616 which will allow use of NAND instructions provided by the
6617 backend if they exist. */
6618 if (TREE_CODE (arg0) == BIT_NOT_EXPR
6619 && TREE_CODE (arg1) == BIT_NOT_EXPR)
6621 return fold (build1 (BIT_NOT_EXPR, type,
6622 build (BIT_AND_EXPR, type,
6623 TREE_OPERAND (arg0, 0),
6624 TREE_OPERAND (arg1, 0))));
6627 /* See if this can be simplified into a rotate first. If that
6628 is unsuccessful continue in the association code. */
6632 if (integer_zerop (arg1))
6633 return non_lvalue (fold_convert (type, arg0));
6634 if (integer_all_onesp (arg1))
6635 return fold (build1 (BIT_NOT_EXPR, type, arg0));
6637 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
6638 with a constant, and the two constants have no bits in common,
6639 we should treat this as a BIT_IOR_EXPR since this may produce more
6641 if (TREE_CODE (arg0) == BIT_AND_EXPR
6642 && TREE_CODE (arg1) == BIT_AND_EXPR
6643 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6644 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
6645 && integer_zerop (const_binop (BIT_AND_EXPR,
6646 TREE_OPERAND (arg0, 1),
6647 TREE_OPERAND (arg1, 1), 0)))
6649 code = BIT_IOR_EXPR;
6653 /* See if this can be simplified into a rotate first. If that
6654 is unsuccessful continue in the association code. */
6658 if (integer_all_onesp (arg1))
6659 return non_lvalue (fold_convert (type, arg0));
6660 if (integer_zerop (arg1))
6661 return omit_one_operand (type, arg1, arg0);
6662 t1 = distribute_bit_expr (code, type, arg0, arg1);
6663 if (t1 != NULL_TREE)
6665 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
6666 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
6667 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
6670 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
6672 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
6673 && (~TREE_INT_CST_LOW (arg1)
6674 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
6675 return fold_convert (type, TREE_OPERAND (arg0, 0));
6678 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
6680 This results in more efficient code for machines without a NOR
6681 instruction. Combine will canonicalize to the first form
6682 which will allow use of NOR instructions provided by the
6683 backend if they exist. */
6684 if (TREE_CODE (arg0) == BIT_NOT_EXPR
6685 && TREE_CODE (arg1) == BIT_NOT_EXPR)
6687 return fold (build1 (BIT_NOT_EXPR, type,
6688 build (BIT_IOR_EXPR, type,
6689 TREE_OPERAND (arg0, 0),
6690 TREE_OPERAND (arg1, 0))));
6696 /* Don't touch a floating-point divide by zero unless the mode
6697 of the constant can represent infinity. */
6698 if (TREE_CODE (arg1) == REAL_CST
6699 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
6700 && real_zerop (arg1))
6703 /* (-A) / (-B) -> A / B */
6704 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
6705 return fold (build (RDIV_EXPR, type,
6706 TREE_OPERAND (arg0, 0),
6707 negate_expr (arg1)));
6708 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
6709 return fold (build (RDIV_EXPR, type,
6711 TREE_OPERAND (arg1, 0)));
6713 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
6714 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
6715 && real_onep (arg1))
6716 return non_lvalue (fold_convert (type, arg0));
6718 /* In IEEE floating point, x/-1 is not equivalent to -x for snans. */
6719 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
6720 && real_minus_onep (arg1))
6721 return non_lvalue (fold_convert (type, negate_expr (arg0)));
6723 /* If ARG1 is a constant, we can convert this to a multiply by the
6724 reciprocal. This does not have the same rounding properties,
6725 so only do this if -funsafe-math-optimizations. We can actually
6726 always safely do it if ARG1 is a power of two, but it's hard to
6727 tell if it is or not in a portable manner. */
6728 if (TREE_CODE (arg1) == REAL_CST)
6730 if (flag_unsafe_math_optimizations
6731 && 0 != (tem = const_binop (code, build_real (type, dconst1),
6733 return fold (build (MULT_EXPR, type, arg0, tem));
6734 /* Find the reciprocal if optimizing and the result is exact. */
6738 r = TREE_REAL_CST (arg1);
6739 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
6741 tem = build_real (type, r);
6742 return fold (build (MULT_EXPR, type, arg0, tem));
6746 /* Convert A/B/C to A/(B*C). */
6747 if (flag_unsafe_math_optimizations
6748 && TREE_CODE (arg0) == RDIV_EXPR)
6749 return fold (build (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
6750 fold (build (MULT_EXPR, type,
6751 TREE_OPERAND (arg0, 1), arg1))));
6753 /* Convert A/(B/C) to (A/B)*C. */
6754 if (flag_unsafe_math_optimizations
6755 && TREE_CODE (arg1) == RDIV_EXPR)
6756 return fold (build (MULT_EXPR, type,
6757 fold (build (RDIV_EXPR, type, arg0,
6758 TREE_OPERAND (arg1, 0))),
6759 TREE_OPERAND (arg1, 1)));
6761 /* Convert C1/(X*C2) into (C1/C2)/X. */
6762 if (flag_unsafe_math_optimizations
6763 && TREE_CODE (arg1) == MULT_EXPR
6764 && TREE_CODE (arg0) == REAL_CST
6765 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
6767 tree tem = const_binop (RDIV_EXPR, arg0,
6768 TREE_OPERAND (arg1, 1), 0);
6770 return fold (build (RDIV_EXPR, type, tem,
6771 TREE_OPERAND (arg1, 0)));
6774 if (flag_unsafe_math_optimizations)
6776 enum built_in_function fcode = builtin_mathfn_code (arg1);
6777 /* Optimize x/expN(y) into x*expN(-y). */
6778 if (BUILTIN_EXPONENT_P (fcode))
6780 tree expfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
6781 tree arg = build1 (NEGATE_EXPR, type,
6782 TREE_VALUE (TREE_OPERAND (arg1, 1)));
6783 tree arglist = build_tree_list (NULL_TREE, fold (arg));
6784 arg1 = build_function_call_expr (expfn, arglist);
6785 return fold (build (MULT_EXPR, type, arg0, arg1));
6788 /* Optimize x/pow(y,z) into x*pow(y,-z). */
6789 if (fcode == BUILT_IN_POW
6790 || fcode == BUILT_IN_POWF
6791 || fcode == BUILT_IN_POWL)
6793 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
6794 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
6795 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1, 1)));
6796 tree neg11 = fold (build1 (NEGATE_EXPR, type, arg11));
6797 tree arglist = tree_cons(NULL_TREE, arg10,
6798 build_tree_list (NULL_TREE, neg11));
6799 arg1 = build_function_call_expr (powfn, arglist);
6800 return fold (build (MULT_EXPR, type, arg0, arg1));
6804 if (flag_unsafe_math_optimizations)
6806 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
6807 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
6809 /* Optimize sin(x)/cos(x) as tan(x). */
6810 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_COS)
6811 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_COSF)
6812 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_COSL))
6813 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
6814 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
6818 if (fcode0 == BUILT_IN_SIN)
6819 tanfn = implicit_built_in_decls[BUILT_IN_TAN];
6820 else if (fcode0 == BUILT_IN_SINF)
6821 tanfn = implicit_built_in_decls[BUILT_IN_TANF];
6822 else if (fcode0 == BUILT_IN_SINL)
6823 tanfn = implicit_built_in_decls[BUILT_IN_TANL];
6827 if (tanfn != NULL_TREE)
6828 return build_function_call_expr (tanfn,
6829 TREE_OPERAND (arg0, 1));
6832 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
6833 if (((fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_SIN)
6834 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_SINF)
6835 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_SINL))
6836 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
6837 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
6841 if (fcode0 == BUILT_IN_COS)
6842 tanfn = implicit_built_in_decls[BUILT_IN_TAN];
6843 else if (fcode0 == BUILT_IN_COSF)
6844 tanfn = implicit_built_in_decls[BUILT_IN_TANF];
6845 else if (fcode0 == BUILT_IN_COSL)
6846 tanfn = implicit_built_in_decls[BUILT_IN_TANL];
6850 if (tanfn != NULL_TREE)
6852 tree tmp = TREE_OPERAND (arg0, 1);
6853 tmp = build_function_call_expr (tanfn, tmp);
6854 return fold (build (RDIV_EXPR, type,
6855 build_real (type, dconst1),
6860 /* Optimize pow(x,c)/x as pow(x,c-1). */
6861 if (fcode0 == BUILT_IN_POW
6862 || fcode0 == BUILT_IN_POWF
6863 || fcode0 == BUILT_IN_POWL)
6865 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
6866 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0, 1)));
6867 if (TREE_CODE (arg01) == REAL_CST
6868 && ! TREE_CONSTANT_OVERFLOW (arg01)
6869 && operand_equal_p (arg1, arg00, 0))
6871 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
6875 c = TREE_REAL_CST (arg01);
6876 real_arithmetic (&c, MINUS_EXPR, &c, &dconst1);
6877 arg = build_real (type, c);
6878 arglist = build_tree_list (NULL_TREE, arg);
6879 arglist = tree_cons (NULL_TREE, arg1, arglist);
6880 return build_function_call_expr (powfn, arglist);
6886 case TRUNC_DIV_EXPR:
6887 case ROUND_DIV_EXPR:
6888 case FLOOR_DIV_EXPR:
6890 case EXACT_DIV_EXPR:
6891 if (integer_onep (arg1))
6892 return non_lvalue (fold_convert (type, arg0));
6893 if (integer_zerop (arg1))
6896 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
6897 operation, EXACT_DIV_EXPR.
6899 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
6900 At one time others generated faster code, it's not clear if they do
6901 after the last round to changes to the DIV code in expmed.c. */
6902 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
6903 && multiple_of_p (type, arg0, arg1))
6904 return fold (build (EXACT_DIV_EXPR, type, arg0, arg1));
6906 if (TREE_CODE (arg1) == INTEGER_CST
6907 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
6909 return fold_convert (type, tem);
6914 case FLOOR_MOD_EXPR:
6915 case ROUND_MOD_EXPR:
6916 case TRUNC_MOD_EXPR:
6917 if (integer_onep (arg1))
6918 return omit_one_operand (type, integer_zero_node, arg0);
6919 if (integer_zerop (arg1))
6922 if (TREE_CODE (arg1) == INTEGER_CST
6923 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
6925 return fold_convert (type, tem);
6931 if (integer_all_onesp (arg0))
6932 return omit_one_operand (type, arg0, arg1);
6936 /* Optimize -1 >> x for arithmetic right shifts. */
6937 if (integer_all_onesp (arg0) && ! TREE_UNSIGNED (type))
6938 return omit_one_operand (type, arg0, arg1);
6939 /* ... fall through ... */
6943 if (integer_zerop (arg1))
6944 return non_lvalue (fold_convert (type, arg0));
6945 if (integer_zerop (arg0))
6946 return omit_one_operand (type, arg0, arg1);
6948 /* Since negative shift count is not well-defined,
6949 don't try to compute it in the compiler. */
6950 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
6952 /* Rewrite an LROTATE_EXPR by a constant into an
6953 RROTATE_EXPR by a new constant. */
6954 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
6956 tree tem = build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type)), 0);
6957 tem = fold_convert (TREE_TYPE (arg1), tem);
6958 tem = const_binop (MINUS_EXPR, tem, arg1, 0);
6959 return fold (build (RROTATE_EXPR, type, arg0, tem));
6962 /* If we have a rotate of a bit operation with the rotate count and
6963 the second operand of the bit operation both constant,
6964 permute the two operations. */
6965 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
6966 && (TREE_CODE (arg0) == BIT_AND_EXPR
6967 || TREE_CODE (arg0) == BIT_IOR_EXPR
6968 || TREE_CODE (arg0) == BIT_XOR_EXPR)
6969 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
6970 return fold (build (TREE_CODE (arg0), type,
6971 fold (build (code, type,
6972 TREE_OPERAND (arg0, 0), arg1)),
6973 fold (build (code, type,
6974 TREE_OPERAND (arg0, 1), arg1))));
6976 /* Two consecutive rotates adding up to the width of the mode can
6978 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
6979 && TREE_CODE (arg0) == RROTATE_EXPR
6980 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6981 && TREE_INT_CST_HIGH (arg1) == 0
6982 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
6983 && ((TREE_INT_CST_LOW (arg1)
6984 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
6985 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type))))
6986 return TREE_OPERAND (arg0, 0);
6991 if (operand_equal_p (arg0, arg1, 0))
6992 return omit_one_operand (type, arg0, arg1);
6993 if (INTEGRAL_TYPE_P (type)
6994 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), 1))
6995 return omit_one_operand (type, arg1, arg0);
6999 if (operand_equal_p (arg0, arg1, 0))
7000 return omit_one_operand (type, arg0, arg1);
7001 if (INTEGRAL_TYPE_P (type)
7002 && TYPE_MAX_VALUE (type)
7003 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), 1))
7004 return omit_one_operand (type, arg1, arg0);
7007 case TRUTH_NOT_EXPR:
7008 /* Note that the operand of this must be an int
7009 and its values must be 0 or 1.
7010 ("true" is a fixed value perhaps depending on the language,
7011 but we don't handle values other than 1 correctly yet.) */
7012 tem = invert_truthvalue (arg0);
7013 /* Avoid infinite recursion. */
7014 if (TREE_CODE (tem) == TRUTH_NOT_EXPR)
7016 tem = fold_single_bit_test (code, arg0, arg1, type);
7021 return fold_convert (type, tem);
7023 case TRUTH_ANDIF_EXPR:
7024 /* Note that the operands of this must be ints
7025 and their values must be 0 or 1.
7026 ("true" is a fixed value perhaps depending on the language.) */
7027 /* If first arg is constant zero, return it. */
7028 if (integer_zerop (arg0))
7029 return fold_convert (type, arg0);
7030 case TRUTH_AND_EXPR:
7031 /* If either arg is constant true, drop it. */
7032 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
7033 return non_lvalue (fold_convert (type, arg1));
7034 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
7035 /* Preserve sequence points. */
7036 && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
7037 return non_lvalue (fold_convert (type, arg0));
7038 /* If second arg is constant zero, result is zero, but first arg
7039 must be evaluated. */
7040 if (integer_zerop (arg1))
7041 return omit_one_operand (type, arg1, arg0);
7042 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
7043 case will be handled here. */
7044 if (integer_zerop (arg0))
7045 return omit_one_operand (type, arg0, arg1);
7048 /* We only do these simplifications if we are optimizing. */
7052 /* Check for things like (A || B) && (A || C). We can convert this
7053 to A || (B && C). Note that either operator can be any of the four
7054 truth and/or operations and the transformation will still be
7055 valid. Also note that we only care about order for the
7056 ANDIF and ORIF operators. If B contains side effects, this
7057 might change the truth-value of A. */
7058 if (TREE_CODE (arg0) == TREE_CODE (arg1)
7059 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
7060 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
7061 || TREE_CODE (arg0) == TRUTH_AND_EXPR
7062 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
7063 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
7065 tree a00 = TREE_OPERAND (arg0, 0);
7066 tree a01 = TREE_OPERAND (arg0, 1);
7067 tree a10 = TREE_OPERAND (arg1, 0);
7068 tree a11 = TREE_OPERAND (arg1, 1);
7069 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
7070 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
7071 && (code == TRUTH_AND_EXPR
7072 || code == TRUTH_OR_EXPR));
7074 if (operand_equal_p (a00, a10, 0))
7075 return fold (build (TREE_CODE (arg0), type, a00,
7076 fold (build (code, type, a01, a11))));
7077 else if (commutative && operand_equal_p (a00, a11, 0))
7078 return fold (build (TREE_CODE (arg0), type, a00,
7079 fold (build (code, type, a01, a10))));
7080 else if (commutative && operand_equal_p (a01, a10, 0))
7081 return fold (build (TREE_CODE (arg0), type, a01,
7082 fold (build (code, type, a00, a11))));
7084 /* This case if tricky because we must either have commutative
7085 operators or else A10 must not have side-effects. */
7087 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
7088 && operand_equal_p (a01, a11, 0))
7089 return fold (build (TREE_CODE (arg0), type,
7090 fold (build (code, type, a00, a10)),
7094 /* See if we can build a range comparison. */
7095 if (0 != (tem = fold_range_test (t)))
7098 /* Check for the possibility of merging component references. If our
7099 lhs is another similar operation, try to merge its rhs with our
7100 rhs. Then try to merge our lhs and rhs. */
7101 if (TREE_CODE (arg0) == code
7102 && 0 != (tem = fold_truthop (code, type,
7103 TREE_OPERAND (arg0, 1), arg1)))
7104 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
7106 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
7111 case TRUTH_ORIF_EXPR:
7112 /* Note that the operands of this must be ints
7113 and their values must be 0 or true.
7114 ("true" is a fixed value perhaps depending on the language.) */
7115 /* If first arg is constant true, return it. */
7116 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
7117 return fold_convert (type, arg0);
7119 /* If either arg is constant zero, drop it. */
7120 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
7121 return non_lvalue (fold_convert (type, arg1));
7122 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
7123 /* Preserve sequence points. */
7124 && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
7125 return non_lvalue (fold_convert (type, arg0));
7126 /* If second arg is constant true, result is true, but we must
7127 evaluate first arg. */
7128 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
7129 return omit_one_operand (type, arg1, arg0);
7130 /* Likewise for first arg, but note this only occurs here for
7132 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
7133 return omit_one_operand (type, arg0, arg1);
7136 case TRUTH_XOR_EXPR:
7137 /* If either arg is constant zero, drop it. */
7138 if (integer_zerop (arg0))
7139 return non_lvalue (fold_convert (type, arg1));
7140 if (integer_zerop (arg1))
7141 return non_lvalue (fold_convert (type, arg0));
7142 /* If either arg is constant true, this is a logical inversion. */
7143 if (integer_onep (arg0))
7144 return non_lvalue (fold_convert (type, invert_truthvalue (arg1)));
7145 if (integer_onep (arg1))
7146 return non_lvalue (fold_convert (type, invert_truthvalue (arg0)));
7155 /* If one arg is a real or integer constant, put it last. */
7156 if (tree_swap_operands_p (arg0, arg1, true))
7157 return fold (build (swap_tree_comparison (code), type, arg1, arg0));
7159 /* If this is an equality comparison of the address of a non-weak
7160 object against zero, then we know the result. */
7161 if ((code == EQ_EXPR || code == NE_EXPR)
7162 && TREE_CODE (arg0) == ADDR_EXPR
7163 && DECL_P (TREE_OPERAND (arg0, 0))
7164 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
7165 && integer_zerop (arg1))
7167 if (code == EQ_EXPR)
7168 return integer_zero_node;
7170 return integer_one_node;
7173 /* If this is an equality comparison of the address of two non-weak,
7174 unaliased symbols neither of which are extern (since we do not
7175 have access to attributes for externs), then we know the result. */
7176 if ((code == EQ_EXPR || code == NE_EXPR)
7177 && TREE_CODE (arg0) == ADDR_EXPR
7178 && DECL_P (TREE_OPERAND (arg0, 0))
7179 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
7180 && ! lookup_attribute ("alias",
7181 DECL_ATTRIBUTES (TREE_OPERAND (arg0, 0)))
7182 && ! DECL_EXTERNAL (TREE_OPERAND (arg0, 0))
7183 && TREE_CODE (arg1) == ADDR_EXPR
7184 && DECL_P (TREE_OPERAND (arg1, 0))
7185 && ! DECL_WEAK (TREE_OPERAND (arg1, 0))
7186 && ! lookup_attribute ("alias",
7187 DECL_ATTRIBUTES (TREE_OPERAND (arg1, 0)))
7188 && ! DECL_EXTERNAL (TREE_OPERAND (arg1, 0)))
7190 if (code == EQ_EXPR)
7191 return (operand_equal_p (arg0, arg1, 0)
7192 ? integer_one_node : integer_zero_node);
7194 return (operand_equal_p (arg0, arg1, 0)
7195 ? integer_zero_node : integer_one_node);
7198 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
7200 tree targ0 = strip_float_extensions (arg0);
7201 tree targ1 = strip_float_extensions (arg1);
7202 tree newtype = TREE_TYPE (targ0);
7204 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
7205 newtype = TREE_TYPE (targ1);
7207 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
7208 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
7209 return fold (build (code, type, fold_convert (newtype, targ0),
7210 fold_convert (newtype, targ1)));
7212 /* (-a) CMP (-b) -> b CMP a */
7213 if (TREE_CODE (arg0) == NEGATE_EXPR
7214 && TREE_CODE (arg1) == NEGATE_EXPR)
7215 return fold (build (code, type, TREE_OPERAND (arg1, 0),
7216 TREE_OPERAND (arg0, 0)));
7218 if (TREE_CODE (arg1) == REAL_CST)
7220 REAL_VALUE_TYPE cst;
7221 cst = TREE_REAL_CST (arg1);
7223 /* (-a) CMP CST -> a swap(CMP) (-CST) */
7224 if (TREE_CODE (arg0) == NEGATE_EXPR)
7226 fold (build (swap_tree_comparison (code), type,
7227 TREE_OPERAND (arg0, 0),
7228 build_real (TREE_TYPE (arg1),
7229 REAL_VALUE_NEGATE (cst))));
7231 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
7232 /* a CMP (-0) -> a CMP 0 */
7233 if (REAL_VALUE_MINUS_ZERO (cst))
7234 return fold (build (code, type, arg0,
7235 build_real (TREE_TYPE (arg1), dconst0)));
7237 /* x != NaN is always true, other ops are always false. */
7238 if (REAL_VALUE_ISNAN (cst)
7239 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))))
7241 t = (code == NE_EXPR) ? integer_one_node : integer_zero_node;
7242 return omit_one_operand (type, fold_convert (type, t), arg0);
7245 /* Fold comparisons against infinity. */
7246 if (REAL_VALUE_ISINF (cst))
7248 tem = fold_inf_compare (code, type, arg0, arg1);
7249 if (tem != NULL_TREE)
7254 /* If this is a comparison of a real constant with a PLUS_EXPR
7255 or a MINUS_EXPR of a real constant, we can convert it into a
7256 comparison with a revised real constant as long as no overflow
7257 occurs when unsafe_math_optimizations are enabled. */
7258 if (flag_unsafe_math_optimizations
7259 && TREE_CODE (arg1) == REAL_CST
7260 && (TREE_CODE (arg0) == PLUS_EXPR
7261 || TREE_CODE (arg0) == MINUS_EXPR)
7262 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
7263 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
7264 ? MINUS_EXPR : PLUS_EXPR,
7265 arg1, TREE_OPERAND (arg0, 1), 0))
7266 && ! TREE_CONSTANT_OVERFLOW (tem))
7267 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
7269 /* Likewise, we can simplify a comparison of a real constant with
7270 a MINUS_EXPR whose first operand is also a real constant, i.e.
7271 (c1 - x) < c2 becomes x > c1-c2. */
7272 if (flag_unsafe_math_optimizations
7273 && TREE_CODE (arg1) == REAL_CST
7274 && TREE_CODE (arg0) == MINUS_EXPR
7275 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST
7276 && 0 != (tem = const_binop (MINUS_EXPR, TREE_OPERAND (arg0, 0),
7278 && ! TREE_CONSTANT_OVERFLOW (tem))
7279 return fold (build (swap_tree_comparison (code), type,
7280 TREE_OPERAND (arg0, 1), tem));
7282 /* Fold comparisons against built-in math functions. */
7283 if (TREE_CODE (arg1) == REAL_CST
7284 && flag_unsafe_math_optimizations
7285 && ! flag_errno_math)
7287 enum built_in_function fcode = builtin_mathfn_code (arg0);
7289 if (fcode != END_BUILTINS)
7291 tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
7292 if (tem != NULL_TREE)
7298 /* Convert foo++ == CONST into ++foo == CONST + INCR.
7299 First, see if one arg is constant; find the constant arg
7300 and the other one. */
7302 tree constop = 0, varop = NULL_TREE;
7303 int constopnum = -1;
7305 if (TREE_CONSTANT (arg1))
7306 constopnum = 1, constop = arg1, varop = arg0;
7307 if (TREE_CONSTANT (arg0))
7308 constopnum = 0, constop = arg0, varop = arg1;
7310 if (constop && TREE_CODE (varop) == POSTINCREMENT_EXPR)
7312 /* This optimization is invalid for ordered comparisons
7313 if CONST+INCR overflows or if foo+incr might overflow.
7314 This optimization is invalid for floating point due to rounding.
7315 For pointer types we assume overflow doesn't happen. */
7316 if (POINTER_TYPE_P (TREE_TYPE (varop))
7317 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
7318 && (code == EQ_EXPR || code == NE_EXPR)))
7321 = fold (build (PLUS_EXPR, TREE_TYPE (varop),
7322 constop, TREE_OPERAND (varop, 1)));
7324 /* Do not overwrite the current varop to be a preincrement,
7325 create a new node so that we won't confuse our caller who
7326 might create trees and throw them away, reusing the
7327 arguments that they passed to build. This shows up in
7328 the THEN or ELSE parts of ?: being postincrements. */
7329 varop = build (PREINCREMENT_EXPR, TREE_TYPE (varop),
7330 TREE_OPERAND (varop, 0),
7331 TREE_OPERAND (varop, 1));
7333 /* If VAROP is a reference to a bitfield, we must mask
7334 the constant by the width of the field. */
7335 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
7336 && DECL_BIT_FIELD(TREE_OPERAND
7337 (TREE_OPERAND (varop, 0), 1)))
7340 = TREE_INT_CST_LOW (DECL_SIZE
7342 (TREE_OPERAND (varop, 0), 1)));
7343 tree mask, unsigned_type;
7344 unsigned int precision;
7345 tree folded_compare;
7347 /* First check whether the comparison would come out
7348 always the same. If we don't do that we would
7349 change the meaning with the masking. */
7350 if (constopnum == 0)
7351 folded_compare = fold (build (code, type, constop,
7352 TREE_OPERAND (varop, 0)));
7354 folded_compare = fold (build (code, type,
7355 TREE_OPERAND (varop, 0),
7357 if (integer_zerop (folded_compare)
7358 || integer_onep (folded_compare))
7359 return omit_one_operand (type, folded_compare, varop);
7361 unsigned_type = (*lang_hooks.types.type_for_size)(size, 1);
7362 precision = TYPE_PRECISION (unsigned_type);
7363 mask = build_int_2 (~0, ~0);
7364 TREE_TYPE (mask) = unsigned_type;
7365 force_fit_type (mask, 0);
7366 mask = const_binop (RSHIFT_EXPR, mask,
7367 size_int (precision - size), 0);
7368 newconst = fold (build (BIT_AND_EXPR,
7369 TREE_TYPE (varop), newconst,
7370 fold_convert (TREE_TYPE (varop),
7374 t = build (code, type,
7375 (constopnum == 0) ? newconst : varop,
7376 (constopnum == 1) ? newconst : varop);
7380 else if (constop && TREE_CODE (varop) == POSTDECREMENT_EXPR)
7382 if (POINTER_TYPE_P (TREE_TYPE (varop))
7383 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
7384 && (code == EQ_EXPR || code == NE_EXPR)))
7387 = fold (build (MINUS_EXPR, TREE_TYPE (varop),
7388 constop, TREE_OPERAND (varop, 1)));
7390 /* Do not overwrite the current varop to be a predecrement,
7391 create a new node so that we won't confuse our caller who
7392 might create trees and throw them away, reusing the
7393 arguments that they passed to build. This shows up in
7394 the THEN or ELSE parts of ?: being postdecrements. */
7395 varop = build (PREDECREMENT_EXPR, TREE_TYPE (varop),
7396 TREE_OPERAND (varop, 0),
7397 TREE_OPERAND (varop, 1));
7399 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
7400 && DECL_BIT_FIELD(TREE_OPERAND
7401 (TREE_OPERAND (varop, 0), 1)))
7404 = TREE_INT_CST_LOW (DECL_SIZE
7406 (TREE_OPERAND (varop, 0), 1)));
7407 tree mask, unsigned_type;
7408 unsigned int precision;
7409 tree folded_compare;
7411 if (constopnum == 0)
7412 folded_compare = fold (build (code, type, constop,
7413 TREE_OPERAND (varop, 0)));
7415 folded_compare = fold (build (code, type,
7416 TREE_OPERAND (varop, 0),
7418 if (integer_zerop (folded_compare)
7419 || integer_onep (folded_compare))
7420 return omit_one_operand (type, folded_compare, varop);
7422 unsigned_type = (*lang_hooks.types.type_for_size)(size, 1);
7423 precision = TYPE_PRECISION (unsigned_type);
7424 mask = build_int_2 (~0, ~0);
7425 TREE_TYPE (mask) = TREE_TYPE (varop);
7426 force_fit_type (mask, 0);
7427 mask = const_binop (RSHIFT_EXPR, mask,
7428 size_int (precision - size), 0);
7429 newconst = fold (build (BIT_AND_EXPR,
7430 TREE_TYPE (varop), newconst,
7431 fold_convert (TREE_TYPE (varop),
7435 t = build (code, type,
7436 (constopnum == 0) ? newconst : varop,
7437 (constopnum == 1) ? newconst : varop);
7443 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
7444 This transformation affects the cases which are handled in later
7445 optimizations involving comparisons with non-negative constants. */
7446 if (TREE_CODE (arg1) == INTEGER_CST
7447 && TREE_CODE (arg0) != INTEGER_CST
7448 && tree_int_cst_sgn (arg1) > 0)
7453 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
7454 return fold (build (GT_EXPR, type, arg0, arg1));
7457 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
7458 return fold (build (LE_EXPR, type, arg0, arg1));
7465 /* Comparisons with the highest or lowest possible integer of
7466 the specified size will have known values. */
7468 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1)));
7470 if (TREE_CODE (arg1) == INTEGER_CST
7471 && ! TREE_CONSTANT_OVERFLOW (arg1)
7472 && width <= HOST_BITS_PER_WIDE_INT
7473 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
7474 || POINTER_TYPE_P (TREE_TYPE (arg1))))
7476 unsigned HOST_WIDE_INT signed_max;
7477 unsigned HOST_WIDE_INT max, min;
7479 signed_max = ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1;
7481 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
7483 max = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
7489 min = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
7492 if (TREE_INT_CST_HIGH (arg1) == 0
7493 && TREE_INT_CST_LOW (arg1) == max)
7497 return omit_one_operand (type,
7502 return fold (build (EQ_EXPR, type, arg0, arg1));
7505 return omit_one_operand (type,
7510 return fold (build (NE_EXPR, type, arg0, arg1));
7512 /* The GE_EXPR and LT_EXPR cases above are not normally
7513 reached because of previous transformations. */
7518 else if (TREE_INT_CST_HIGH (arg1) == 0
7519 && TREE_INT_CST_LOW (arg1) == max - 1)
7523 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
7524 return fold (build (EQ_EXPR, type, arg0, arg1));
7526 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
7527 return fold (build (NE_EXPR, type, arg0, arg1));
7531 else if (TREE_INT_CST_HIGH (arg1) == (min ? -1 : 0)
7532 && TREE_INT_CST_LOW (arg1) == min)
7536 return omit_one_operand (type,
7541 return fold (build (EQ_EXPR, type, arg0, arg1));
7544 return omit_one_operand (type,
7549 return fold (build (NE_EXPR, type, arg0, arg1));
7554 else if (TREE_INT_CST_HIGH (arg1) == (min ? -1 : 0)
7555 && TREE_INT_CST_LOW (arg1) == min + 1)
7559 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
7560 return fold (build (NE_EXPR, type, arg0, arg1));
7562 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
7563 return fold (build (EQ_EXPR, type, arg0, arg1));
7568 else if (TREE_INT_CST_HIGH (arg1) == 0
7569 && TREE_INT_CST_LOW (arg1) == signed_max
7570 && TREE_UNSIGNED (TREE_TYPE (arg1))
7571 /* signed_type does not work on pointer types. */
7572 && INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
7574 /* The following case also applies to X < signed_max+1
7575 and X >= signed_max+1 because previous transformations. */
7576 if (code == LE_EXPR || code == GT_EXPR)
7579 st0 = (*lang_hooks.types.signed_type) (TREE_TYPE (arg0));
7580 st1 = (*lang_hooks.types.signed_type) (TREE_TYPE (arg1));
7582 (build (code == LE_EXPR ? GE_EXPR: LT_EXPR,
7583 type, fold_convert (st0, arg0),
7584 fold_convert (st1, integer_zero_node)));
7590 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
7591 a MINUS_EXPR of a constant, we can convert it into a comparison with
7592 a revised constant as long as no overflow occurs. */
7593 if ((code == EQ_EXPR || code == NE_EXPR)
7594 && TREE_CODE (arg1) == INTEGER_CST
7595 && (TREE_CODE (arg0) == PLUS_EXPR
7596 || TREE_CODE (arg0) == MINUS_EXPR)
7597 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7598 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
7599 ? MINUS_EXPR : PLUS_EXPR,
7600 arg1, TREE_OPERAND (arg0, 1), 0))
7601 && ! TREE_CONSTANT_OVERFLOW (tem))
7602 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
7604 /* Similarly for a NEGATE_EXPR. */
7605 else if ((code == EQ_EXPR || code == NE_EXPR)
7606 && TREE_CODE (arg0) == NEGATE_EXPR
7607 && TREE_CODE (arg1) == INTEGER_CST
7608 && 0 != (tem = negate_expr (arg1))
7609 && TREE_CODE (tem) == INTEGER_CST
7610 && ! TREE_CONSTANT_OVERFLOW (tem))
7611 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
7613 /* If we have X - Y == 0, we can convert that to X == Y and similarly
7614 for !=. Don't do this for ordered comparisons due to overflow. */
7615 else if ((code == NE_EXPR || code == EQ_EXPR)
7616 && integer_zerop (arg1) && TREE_CODE (arg0) == MINUS_EXPR)
7617 return fold (build (code, type,
7618 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1)));
7620 /* If we are widening one operand of an integer comparison,
7621 see if the other operand is similarly being widened. Perhaps we
7622 can do the comparison in the narrower type. */
7623 else if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
7624 && TREE_CODE (arg0) == NOP_EXPR
7625 && (tem = get_unwidened (arg0, NULL_TREE)) != arg0
7626 && (t1 = get_unwidened (arg1, TREE_TYPE (tem))) != 0
7627 && (TREE_TYPE (t1) == TREE_TYPE (tem)
7628 || (TREE_CODE (t1) == INTEGER_CST
7629 && int_fits_type_p (t1, TREE_TYPE (tem)))))
7630 return fold (build (code, type, tem,
7631 fold_convert (TREE_TYPE (tem), t1)));
7633 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
7634 constant, we can simplify it. */
7635 else if (TREE_CODE (arg1) == INTEGER_CST
7636 && (TREE_CODE (arg0) == MIN_EXPR
7637 || TREE_CODE (arg0) == MAX_EXPR)
7638 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
7639 return optimize_minmax_comparison (t);
7641 /* If we are comparing an ABS_EXPR with a constant, we can
7642 convert all the cases into explicit comparisons, but they may
7643 well not be faster than doing the ABS and one comparison.
7644 But ABS (X) <= C is a range comparison, which becomes a subtraction
7645 and a comparison, and is probably faster. */
7646 else if (code == LE_EXPR && TREE_CODE (arg1) == INTEGER_CST
7647 && TREE_CODE (arg0) == ABS_EXPR
7648 && ! TREE_SIDE_EFFECTS (arg0)
7649 && (0 != (tem = negate_expr (arg1)))
7650 && TREE_CODE (tem) == INTEGER_CST
7651 && ! TREE_CONSTANT_OVERFLOW (tem))
7652 return fold (build (TRUTH_ANDIF_EXPR, type,
7653 build (GE_EXPR, type, TREE_OPERAND (arg0, 0), tem),
7654 build (LE_EXPR, type,
7655 TREE_OPERAND (arg0, 0), arg1)));
7657 /* If this is an EQ or NE comparison with zero and ARG0 is
7658 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
7659 two operations, but the latter can be done in one less insn
7660 on machines that have only two-operand insns or on which a
7661 constant cannot be the first operand. */
7662 if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR)
7663 && TREE_CODE (arg0) == BIT_AND_EXPR)
7665 if (TREE_CODE (TREE_OPERAND (arg0, 0)) == LSHIFT_EXPR
7666 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 0), 0)))
7668 fold (build (code, type,
7669 build (BIT_AND_EXPR, TREE_TYPE (arg0),
7671 TREE_TYPE (TREE_OPERAND (arg0, 0)),
7672 TREE_OPERAND (arg0, 1),
7673 TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)),
7674 fold_convert (TREE_TYPE (arg0),
7677 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
7678 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
7680 fold (build (code, type,
7681 build (BIT_AND_EXPR, TREE_TYPE (arg0),
7683 TREE_TYPE (TREE_OPERAND (arg0, 1)),
7684 TREE_OPERAND (arg0, 0),
7685 TREE_OPERAND (TREE_OPERAND (arg0, 1), 1)),
7686 fold_convert (TREE_TYPE (arg0),
7691 /* If this is an NE or EQ comparison of zero against the result of a
7692 signed MOD operation whose second operand is a power of 2, make
7693 the MOD operation unsigned since it is simpler and equivalent. */
7694 if ((code == NE_EXPR || code == EQ_EXPR)
7695 && integer_zerop (arg1)
7696 && ! TREE_UNSIGNED (TREE_TYPE (arg0))
7697 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
7698 || TREE_CODE (arg0) == CEIL_MOD_EXPR
7699 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
7700 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
7701 && integer_pow2p (TREE_OPERAND (arg0, 1)))
7703 tree newtype = (*lang_hooks.types.unsigned_type) (TREE_TYPE (arg0));
7704 tree newmod = build (TREE_CODE (arg0), newtype,
7705 fold_convert (newtype,
7706 TREE_OPERAND (arg0, 0)),
7707 fold_convert (newtype,
7708 TREE_OPERAND (arg0, 1)));
7710 return build (code, type, newmod, fold_convert (newtype, arg1));
7713 /* If this is an NE comparison of zero with an AND of one, remove the
7714 comparison since the AND will give the correct value. */
7715 if (code == NE_EXPR && integer_zerop (arg1)
7716 && TREE_CODE (arg0) == BIT_AND_EXPR
7717 && integer_onep (TREE_OPERAND (arg0, 1)))
7718 return fold_convert (type, arg0);
7720 /* If we have (A & C) == C where C is a power of 2, convert this into
7721 (A & C) != 0. Similarly for NE_EXPR. */
7722 if ((code == EQ_EXPR || code == NE_EXPR)
7723 && TREE_CODE (arg0) == BIT_AND_EXPR
7724 && integer_pow2p (TREE_OPERAND (arg0, 1))
7725 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
7726 return fold (build (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
7727 arg0, integer_zero_node));
7729 /* If we have (A & C) != 0 or (A & C) == 0 and C is a power of
7730 2, then fold the expression into shifts and logical operations. */
7731 tem = fold_single_bit_test (code, arg0, arg1, type);
7735 /* If we have (A & C) == D where D & ~C != 0, convert this into 0.
7736 Similarly for NE_EXPR. */
7737 if ((code == EQ_EXPR || code == NE_EXPR)
7738 && TREE_CODE (arg0) == BIT_AND_EXPR
7739 && TREE_CODE (arg1) == INTEGER_CST
7740 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
7743 = fold (build (BIT_AND_EXPR, TREE_TYPE (arg0),
7744 arg1, build1 (BIT_NOT_EXPR,
7745 TREE_TYPE (TREE_OPERAND (arg0, 1)),
7746 TREE_OPERAND (arg0, 1))));
7747 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
7748 if (integer_nonzerop (dandnotc))
7749 return omit_one_operand (type, rslt, arg0);
7752 /* If we have (A | C) == D where C & ~D != 0, convert this into 0.
7753 Similarly for NE_EXPR. */
7754 if ((code == EQ_EXPR || code == NE_EXPR)
7755 && TREE_CODE (arg0) == BIT_IOR_EXPR
7756 && TREE_CODE (arg1) == INTEGER_CST
7757 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
7760 = fold (build (BIT_AND_EXPR, TREE_TYPE (arg0),
7761 TREE_OPERAND (arg0, 1),
7762 build1 (BIT_NOT_EXPR, TREE_TYPE (arg1), arg1)));
7763 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
7764 if (integer_nonzerop (candnotd))
7765 return omit_one_operand (type, rslt, arg0);
7768 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
7769 and similarly for >= into !=. */
7770 if ((code == LT_EXPR || code == GE_EXPR)
7771 && TREE_UNSIGNED (TREE_TYPE (arg0))
7772 && TREE_CODE (arg1) == LSHIFT_EXPR
7773 && integer_onep (TREE_OPERAND (arg1, 0)))
7774 return build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
7775 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
7776 TREE_OPERAND (arg1, 1)),
7777 fold_convert (TREE_TYPE (arg0), integer_zero_node));
7779 else if ((code == LT_EXPR || code == GE_EXPR)
7780 && TREE_UNSIGNED (TREE_TYPE (arg0))
7781 && (TREE_CODE (arg1) == NOP_EXPR
7782 || TREE_CODE (arg1) == CONVERT_EXPR)
7783 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
7784 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
7786 build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
7787 fold_convert (TREE_TYPE (arg0),
7788 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
7789 TREE_OPERAND (TREE_OPERAND (arg1, 0),
7791 fold_convert (TREE_TYPE (arg0), integer_zero_node));
7793 /* Simplify comparison of something with itself. (For IEEE
7794 floating-point, we can only do some of these simplifications.) */
7795 if (operand_equal_p (arg0, arg1, 0))
7800 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
7801 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
7802 return constant_boolean_node (1, type);
7807 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
7808 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
7809 return constant_boolean_node (1, type);
7810 return fold (build (EQ_EXPR, type, arg0, arg1));
7813 /* For NE, we can only do this simplification if integer
7814 or we don't honor IEEE floating point NaNs. */
7815 if (FLOAT_TYPE_P (TREE_TYPE (arg0))
7816 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
7818 /* ... fall through ... */
7821 return constant_boolean_node (0, type);
7827 /* If we are comparing an expression that just has comparisons
7828 of two integer values, arithmetic expressions of those comparisons,
7829 and constants, we can simplify it. There are only three cases
7830 to check: the two values can either be equal, the first can be
7831 greater, or the second can be greater. Fold the expression for
7832 those three values. Since each value must be 0 or 1, we have
7833 eight possibilities, each of which corresponds to the constant 0
7834 or 1 or one of the six possible comparisons.
7836 This handles common cases like (a > b) == 0 but also handles
7837 expressions like ((x > y) - (y > x)) > 0, which supposedly
7838 occur in macroized code. */
7840 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
7842 tree cval1 = 0, cval2 = 0;
7845 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
7846 /* Don't handle degenerate cases here; they should already
7847 have been handled anyway. */
7848 && cval1 != 0 && cval2 != 0
7849 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
7850 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
7851 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
7852 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
7853 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
7854 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
7855 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
7857 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
7858 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
7860 /* We can't just pass T to eval_subst in case cval1 or cval2
7861 was the same as ARG1. */
7864 = fold (build (code, type,
7865 eval_subst (arg0, cval1, maxval, cval2, minval),
7868 = fold (build (code, type,
7869 eval_subst (arg0, cval1, maxval, cval2, maxval),
7872 = fold (build (code, type,
7873 eval_subst (arg0, cval1, minval, cval2, maxval),
7876 /* All three of these results should be 0 or 1. Confirm they
7877 are. Then use those values to select the proper code
7880 if ((integer_zerop (high_result)
7881 || integer_onep (high_result))
7882 && (integer_zerop (equal_result)
7883 || integer_onep (equal_result))
7884 && (integer_zerop (low_result)
7885 || integer_onep (low_result)))
7887 /* Make a 3-bit mask with the high-order bit being the
7888 value for `>', the next for '=', and the low for '<'. */
7889 switch ((integer_onep (high_result) * 4)
7890 + (integer_onep (equal_result) * 2)
7891 + integer_onep (low_result))
7895 return omit_one_operand (type, integer_zero_node, arg0);
7916 return omit_one_operand (type, integer_one_node, arg0);
7919 t = build (code, type, cval1, cval2);
7921 return save_expr (t);
7928 /* If this is a comparison of a field, we may be able to simplify it. */
7929 if (((TREE_CODE (arg0) == COMPONENT_REF
7930 && (*lang_hooks.can_use_bit_fields_p) ())
7931 || TREE_CODE (arg0) == BIT_FIELD_REF)
7932 && (code == EQ_EXPR || code == NE_EXPR)
7933 /* Handle the constant case even without -O
7934 to make sure the warnings are given. */
7935 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
7937 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
7942 /* If this is a comparison of complex values and either or both sides
7943 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
7944 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
7945 This may prevent needless evaluations. */
7946 if ((code == EQ_EXPR || code == NE_EXPR)
7947 && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
7948 && (TREE_CODE (arg0) == COMPLEX_EXPR
7949 || TREE_CODE (arg1) == COMPLEX_EXPR
7950 || TREE_CODE (arg0) == COMPLEX_CST
7951 || TREE_CODE (arg1) == COMPLEX_CST))
7953 tree subtype = TREE_TYPE (TREE_TYPE (arg0));
7954 tree real0, imag0, real1, imag1;
7956 arg0 = save_expr (arg0);
7957 arg1 = save_expr (arg1);
7958 real0 = fold (build1 (REALPART_EXPR, subtype, arg0));
7959 imag0 = fold (build1 (IMAGPART_EXPR, subtype, arg0));
7960 real1 = fold (build1 (REALPART_EXPR, subtype, arg1));
7961 imag1 = fold (build1 (IMAGPART_EXPR, subtype, arg1));
7963 return fold (build ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR
7966 fold (build (code, type, real0, real1)),
7967 fold (build (code, type, imag0, imag1))));
7970 /* Optimize comparisons of strlen vs zero to a compare of the
7971 first character of the string vs zero. To wit,
7972 strlen(ptr) == 0 => *ptr == 0
7973 strlen(ptr) != 0 => *ptr != 0
7974 Other cases should reduce to one of these two (or a constant)
7975 due to the return value of strlen being unsigned. */
7976 if ((code == EQ_EXPR || code == NE_EXPR)
7977 && integer_zerop (arg1)
7978 && TREE_CODE (arg0) == CALL_EXPR)
7980 tree fndecl = get_callee_fndecl (arg0);
7984 && DECL_BUILT_IN (fndecl)
7985 && DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_MD
7986 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
7987 && (arglist = TREE_OPERAND (arg0, 1))
7988 && TREE_CODE (TREE_TYPE (TREE_VALUE (arglist))) == POINTER_TYPE
7989 && ! TREE_CHAIN (arglist))
7990 return fold (build (code, type,
7991 build1 (INDIRECT_REF, char_type_node,
7992 TREE_VALUE(arglist)),
7993 integer_zero_node));
7996 /* From here on, the only cases we handle are when the result is
7997 known to be a constant.
7999 To compute GT, swap the arguments and do LT.
8000 To compute GE, do LT and invert the result.
8001 To compute LE, swap the arguments, do LT and invert the result.
8002 To compute NE, do EQ and invert the result.
8004 Therefore, the code below must handle only EQ and LT. */
8006 if (code == LE_EXPR || code == GT_EXPR)
8008 tem = arg0, arg0 = arg1, arg1 = tem;
8009 code = swap_tree_comparison (code);
8012 /* Note that it is safe to invert for real values here because we
8013 will check below in the one case that it matters. */
8017 if (code == NE_EXPR || code == GE_EXPR)
8020 code = invert_tree_comparison (code);
8023 /* Compute a result for LT or EQ if args permit;
8024 otherwise return T. */
8025 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
8027 if (code == EQ_EXPR)
8028 t1 = build_int_2 (tree_int_cst_equal (arg0, arg1), 0);
8030 t1 = build_int_2 ((TREE_UNSIGNED (TREE_TYPE (arg0))
8031 ? INT_CST_LT_UNSIGNED (arg0, arg1)
8032 : INT_CST_LT (arg0, arg1)),
8036 #if 0 /* This is no longer useful, but breaks some real code. */
8037 /* Assume a nonexplicit constant cannot equal an explicit one,
8038 since such code would be undefined anyway.
8039 Exception: on sysvr4, using #pragma weak,
8040 a label can come out as 0. */
8041 else if (TREE_CODE (arg1) == INTEGER_CST
8042 && !integer_zerop (arg1)
8043 && TREE_CONSTANT (arg0)
8044 && TREE_CODE (arg0) == ADDR_EXPR
8046 t1 = build_int_2 (0, 0);
8048 /* Two real constants can be compared explicitly. */
8049 else if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
8051 /* If either operand is a NaN, the result is false with two
8052 exceptions: First, an NE_EXPR is true on NaNs, but that case
8053 is already handled correctly since we will be inverting the
8054 result for NE_EXPR. Second, if we had inverted a LE_EXPR
8055 or a GE_EXPR into a LT_EXPR, we must return true so that it
8056 will be inverted into false. */
8058 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
8059 || REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
8060 t1 = build_int_2 (invert && code == LT_EXPR, 0);
8062 else if (code == EQ_EXPR)
8063 t1 = build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (arg0),
8064 TREE_REAL_CST (arg1)),
8067 t1 = build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (arg0),
8068 TREE_REAL_CST (arg1)),
8072 if (t1 == NULL_TREE)
8076 TREE_INT_CST_LOW (t1) ^= 1;
8078 TREE_TYPE (t1) = type;
8079 if (TREE_CODE (type) == BOOLEAN_TYPE)
8080 return (*lang_hooks.truthvalue_conversion) (t1);
8084 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
8085 so all simple results must be passed through pedantic_non_lvalue. */
8086 if (TREE_CODE (arg0) == INTEGER_CST)
8088 tem = TREE_OPERAND (t, (integer_zerop (arg0) ? 2 : 1));
8089 /* Only optimize constant conditions when the selected branch
8090 has the same type as the COND_EXPR. This avoids optimizing
8091 away "c ? x : throw", where the throw has a void type. */
8092 if (! VOID_TYPE_P (TREE_TYPE (tem))
8093 || VOID_TYPE_P (TREE_TYPE (t)))
8094 return pedantic_non_lvalue (tem);
8097 if (operand_equal_p (arg1, TREE_OPERAND (expr, 2), 0))
8098 return pedantic_omit_one_operand (type, arg1, arg0);
8100 /* If we have A op B ? A : C, we may be able to convert this to a
8101 simpler expression, depending on the operation and the values
8102 of B and C. Signed zeros prevent all of these transformations,
8103 for reasons given above each one. */
8105 if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
8106 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
8107 arg1, TREE_OPERAND (arg0, 1))
8108 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
8110 tree arg2 = TREE_OPERAND (t, 2);
8111 enum tree_code comp_code = TREE_CODE (arg0);
8115 /* If we have A op 0 ? A : -A, consider applying the following
8118 A == 0? A : -A same as -A
8119 A != 0? A : -A same as A
8120 A >= 0? A : -A same as abs (A)
8121 A > 0? A : -A same as abs (A)
8122 A <= 0? A : -A same as -abs (A)
8123 A < 0? A : -A same as -abs (A)
8125 None of these transformations work for modes with signed
8126 zeros. If A is +/-0, the first two transformations will
8127 change the sign of the result (from +0 to -0, or vice
8128 versa). The last four will fix the sign of the result,
8129 even though the original expressions could be positive or
8130 negative, depending on the sign of A.
8132 Note that all these transformations are correct if A is
8133 NaN, since the two alternatives (A and -A) are also NaNs. */
8134 if ((FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 1)))
8135 ? real_zerop (TREE_OPERAND (arg0, 1))
8136 : integer_zerop (TREE_OPERAND (arg0, 1)))
8137 && TREE_CODE (arg2) == NEGATE_EXPR
8138 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
8142 tem = fold_convert (TREE_TYPE (TREE_OPERAND (t, 1)), arg1);
8143 tem = fold_convert (type, negate_expr (tem));
8144 return pedantic_non_lvalue (tem);
8146 return pedantic_non_lvalue (fold_convert (type, arg1));
8149 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
8150 arg1 = fold_convert ((*lang_hooks.types.signed_type)
8151 (TREE_TYPE (arg1)), arg1);
8152 arg1 = fold (build1 (ABS_EXPR, TREE_TYPE (arg1), arg1));
8153 return pedantic_non_lvalue (fold_convert (type, arg1));
8156 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
8157 arg1 = fold_convert ((lang_hooks.types.signed_type)
8158 (TREE_TYPE (arg1)), arg1);
8159 arg1 = fold (build1 (ABS_EXPR, TREE_TYPE (arg1), arg1));
8160 arg1 = negate_expr (fold_convert (type, arg1));
8161 return pedantic_non_lvalue (arg1);
8166 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
8167 A == 0 ? A : 0 is always 0 unless A is -0. Note that
8168 both transformations are correct when A is NaN: A != 0
8169 is then true, and A == 0 is false. */
8171 if (integer_zerop (TREE_OPERAND (arg0, 1)) && integer_zerop (arg2))
8173 if (comp_code == NE_EXPR)
8174 return pedantic_non_lvalue (fold_convert (type, arg1));
8175 else if (comp_code == EQ_EXPR)
8176 return pedantic_non_lvalue (fold_convert (type, integer_zero_node));
8179 /* Try some transformations of A op B ? A : B.
8181 A == B? A : B same as B
8182 A != B? A : B same as A
8183 A >= B? A : B same as max (A, B)
8184 A > B? A : B same as max (B, A)
8185 A <= B? A : B same as min (A, B)
8186 A < B? A : B same as min (B, A)
8188 As above, these transformations don't work in the presence
8189 of signed zeros. For example, if A and B are zeros of
8190 opposite sign, the first two transformations will change
8191 the sign of the result. In the last four, the original
8192 expressions give different results for (A=+0, B=-0) and
8193 (A=-0, B=+0), but the transformed expressions do not.
8195 The first two transformations are correct if either A or B
8196 is a NaN. In the first transformation, the condition will
8197 be false, and B will indeed be chosen. In the case of the
8198 second transformation, the condition A != B will be true,
8199 and A will be chosen.
8201 The conversions to max() and min() are not correct if B is
8202 a number and A is not. The conditions in the original
8203 expressions will be false, so all four give B. The min()
8204 and max() versions would give a NaN instead. */
8205 if (operand_equal_for_comparison_p (TREE_OPERAND (arg0, 1),
8206 arg2, TREE_OPERAND (arg0, 0)))
8208 tree comp_op0 = TREE_OPERAND (arg0, 0);
8209 tree comp_op1 = TREE_OPERAND (arg0, 1);
8210 tree comp_type = TREE_TYPE (comp_op0);
8212 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
8213 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
8223 return pedantic_non_lvalue (fold_convert (type, arg2));
8225 return pedantic_non_lvalue (fold_convert (type, arg1));
8228 /* In C++ a ?: expression can be an lvalue, so put the
8229 operand which will be used if they are equal first
8230 so that we can convert this back to the
8231 corresponding COND_EXPR. */
8232 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
8233 return pedantic_non_lvalue (fold_convert
8234 (type, fold (build (MIN_EXPR, comp_type,
8235 (comp_code == LE_EXPR
8236 ? comp_op0 : comp_op1),
8237 (comp_code == LE_EXPR
8238 ? comp_op1 : comp_op0)))));
8242 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
8243 return pedantic_non_lvalue (fold_convert
8244 (type, fold (build (MAX_EXPR, comp_type,
8245 (comp_code == GE_EXPR
8246 ? comp_op0 : comp_op1),
8247 (comp_code == GE_EXPR
8248 ? comp_op1 : comp_op0)))));
8255 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
8256 we might still be able to simplify this. For example,
8257 if C1 is one less or one more than C2, this might have started
8258 out as a MIN or MAX and been transformed by this function.
8259 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
8261 if (INTEGRAL_TYPE_P (type)
8262 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8263 && TREE_CODE (arg2) == INTEGER_CST)
8267 /* We can replace A with C1 in this case. */
8268 arg1 = fold_convert (type, TREE_OPERAND (arg0, 1));
8269 return fold (build (code, type, TREE_OPERAND (t, 0), arg1,
8270 TREE_OPERAND (t, 2)));
8273 /* If C1 is C2 + 1, this is min(A, C2). */
8274 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
8275 && operand_equal_p (TREE_OPERAND (arg0, 1),
8276 const_binop (PLUS_EXPR, arg2,
8277 integer_one_node, 0), 1))
8278 return pedantic_non_lvalue
8279 (fold (build (MIN_EXPR, type, arg1, arg2)));
8283 /* If C1 is C2 - 1, this is min(A, C2). */
8284 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
8285 && operand_equal_p (TREE_OPERAND (arg0, 1),
8286 const_binop (MINUS_EXPR, arg2,
8287 integer_one_node, 0), 1))
8288 return pedantic_non_lvalue
8289 (fold (build (MIN_EXPR, type, arg1, arg2)));
8293 /* If C1 is C2 - 1, this is max(A, C2). */
8294 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
8295 && operand_equal_p (TREE_OPERAND (arg0, 1),
8296 const_binop (MINUS_EXPR, arg2,
8297 integer_one_node, 0), 1))
8298 return pedantic_non_lvalue
8299 (fold (build (MAX_EXPR, type, arg1, arg2)));
8303 /* If C1 is C2 + 1, this is max(A, C2). */
8304 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
8305 && operand_equal_p (TREE_OPERAND (arg0, 1),
8306 const_binop (PLUS_EXPR, arg2,
8307 integer_one_node, 0), 1))
8308 return pedantic_non_lvalue
8309 (fold (build (MAX_EXPR, type, arg1, arg2)));
8318 /* If the second operand is simpler than the third, swap them
8319 since that produces better jump optimization results. */
8320 if (tree_swap_operands_p (TREE_OPERAND (t, 1),
8321 TREE_OPERAND (t, 2), false))
8323 /* See if this can be inverted. If it can't, possibly because
8324 it was a floating-point inequality comparison, don't do
8326 tem = invert_truthvalue (arg0);
8328 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
8329 return fold (build (code, type, tem,
8330 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1)));
8333 /* Convert A ? 1 : 0 to simply A. */
8334 if (integer_onep (TREE_OPERAND (t, 1))
8335 && integer_zerop (TREE_OPERAND (t, 2))
8336 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
8337 call to fold will try to move the conversion inside
8338 a COND, which will recurse. In that case, the COND_EXPR
8339 is probably the best choice, so leave it alone. */
8340 && type == TREE_TYPE (arg0))
8341 return pedantic_non_lvalue (arg0);
8343 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
8344 over COND_EXPR in cases such as floating point comparisons. */
8345 if (integer_zerop (TREE_OPERAND (t, 1))
8346 && integer_onep (TREE_OPERAND (t, 2))
8347 && truth_value_p (TREE_CODE (arg0)))
8348 return pedantic_non_lvalue (fold_convert (type,
8349 invert_truthvalue (arg0)));
8351 /* Look for expressions of the form A & 2 ? 2 : 0. The result of this
8352 operation is simply A & 2. */
8354 if (integer_zerop (TREE_OPERAND (t, 2))
8355 && TREE_CODE (arg0) == NE_EXPR
8356 && integer_zerop (TREE_OPERAND (arg0, 1))
8357 && integer_pow2p (arg1)
8358 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
8359 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
8361 return pedantic_non_lvalue (fold_convert (type,
8362 TREE_OPERAND (arg0, 0)));
8364 /* Convert A ? B : 0 into A && B if A and B are truth values. */
8365 if (integer_zerop (TREE_OPERAND (t, 2))
8366 && truth_value_p (TREE_CODE (arg0))
8367 && truth_value_p (TREE_CODE (arg1)))
8368 return pedantic_non_lvalue (fold (build (TRUTH_ANDIF_EXPR, type,
8371 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
8372 if (integer_onep (TREE_OPERAND (t, 2))
8373 && truth_value_p (TREE_CODE (arg0))
8374 && truth_value_p (TREE_CODE (arg1)))
8376 /* Only perform transformation if ARG0 is easily inverted. */
8377 tem = invert_truthvalue (arg0);
8378 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
8379 return pedantic_non_lvalue (fold (build (TRUTH_ORIF_EXPR, type,
8386 /* When pedantic, a compound expression can be neither an lvalue
8387 nor an integer constant expression. */
8388 if (TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
8390 /* Don't let (0, 0) be null pointer constant. */
8391 tem = integer_zerop (arg1) ? build1 (NOP_EXPR, type, arg1)
8392 : fold_convert (type, arg1);
8393 return pedantic_non_lvalue (tem);
8397 return build_complex (type, arg0, arg1);
8401 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8403 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
8404 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
8405 TREE_OPERAND (arg0, 1));
8406 else if (TREE_CODE (arg0) == COMPLEX_CST)
8407 return TREE_REALPART (arg0);
8408 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8409 return fold (build (TREE_CODE (arg0), type,
8410 fold (build1 (REALPART_EXPR, type,
8411 TREE_OPERAND (arg0, 0))),
8412 fold (build1 (REALPART_EXPR,
8413 type, TREE_OPERAND (arg0, 1)))));
8417 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8418 return fold_convert (type, integer_zero_node);
8419 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
8420 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
8421 TREE_OPERAND (arg0, 0));
8422 else if (TREE_CODE (arg0) == COMPLEX_CST)
8423 return TREE_IMAGPART (arg0);
8424 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8425 return fold (build (TREE_CODE (arg0), type,
8426 fold (build1 (IMAGPART_EXPR, type,
8427 TREE_OPERAND (arg0, 0))),
8428 fold (build1 (IMAGPART_EXPR, type,
8429 TREE_OPERAND (arg0, 1)))));
8432 /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
8434 case CLEANUP_POINT_EXPR:
8435 if (! has_cleanups (arg0))
8436 return TREE_OPERAND (t, 0);
8439 enum tree_code code0 = TREE_CODE (arg0);
8440 int kind0 = TREE_CODE_CLASS (code0);
8441 tree arg00 = TREE_OPERAND (arg0, 0);
8444 if (kind0 == '1' || code0 == TRUTH_NOT_EXPR)
8445 return fold (build1 (code0, type,
8446 fold (build1 (CLEANUP_POINT_EXPR,
8447 TREE_TYPE (arg00), arg00))));
8449 if (kind0 == '<' || kind0 == '2'
8450 || code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR
8451 || code0 == TRUTH_AND_EXPR || code0 == TRUTH_OR_EXPR
8452 || code0 == TRUTH_XOR_EXPR)
8454 arg01 = TREE_OPERAND (arg0, 1);
8456 if (TREE_CONSTANT (arg00)
8457 || ((code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR)
8458 && ! has_cleanups (arg00)))
8459 return fold (build (code0, type, arg00,
8460 fold (build1 (CLEANUP_POINT_EXPR,
8461 TREE_TYPE (arg01), arg01))));
8463 if (TREE_CONSTANT (arg01))
8464 return fold (build (code0, type,
8465 fold (build1 (CLEANUP_POINT_EXPR,
8466 TREE_TYPE (arg00), arg00)),
8474 /* Check for a built-in function. */
8475 if (TREE_CODE (TREE_OPERAND (expr, 0)) == ADDR_EXPR
8476 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (expr, 0), 0))
8478 && DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (expr, 0), 0)))
8480 tree tmp = fold_builtin (expr);
8488 } /* switch (code) */
8491 #ifdef ENABLE_FOLD_CHECKING
8494 static void fold_checksum_tree (tree, struct md5_ctx *, htab_t);
8495 static void fold_check_failed (tree, tree);
8496 void print_fold_checksum (tree);
8498 /* When --enable-checking=fold, compute a digest of expr before
8499 and after actual fold call to see if fold did not accidentally
8500 change original expr. */
8507 unsigned char checksum_before[16], checksum_after[16];
8510 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
8511 md5_init_ctx (&ctx);
8512 fold_checksum_tree (expr, &ctx, ht);
8513 md5_finish_ctx (&ctx, checksum_before);
8516 ret = fold_1 (expr);
8518 md5_init_ctx (&ctx);
8519 fold_checksum_tree (expr, &ctx, ht);
8520 md5_finish_ctx (&ctx, checksum_after);
8523 if (memcmp (checksum_before, checksum_after, 16))
8524 fold_check_failed (expr, ret);
8530 print_fold_checksum (tree expr)
8533 unsigned char checksum[16], cnt;
8536 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
8537 md5_init_ctx (&ctx);
8538 fold_checksum_tree (expr, &ctx, ht);
8539 md5_finish_ctx (&ctx, checksum);
8541 for (cnt = 0; cnt < 16; ++cnt)
8542 fprintf (stderr, "%02x", checksum[cnt]);
8543 putc ('\n', stderr);
8547 fold_check_failed (tree expr ATTRIBUTE_UNUSED, tree ret ATTRIBUTE_UNUSED)
8549 internal_error ("fold check: original tree changed by fold");
8553 fold_checksum_tree (tree expr, struct md5_ctx *ctx, htab_t ht)
8556 enum tree_code code;
8557 char buf[sizeof (struct tree_decl)];
8560 if (sizeof (struct tree_exp) + 5 * sizeof (tree)
8561 > sizeof (struct tree_decl)
8562 || sizeof (struct tree_type) > sizeof (struct tree_decl))
8566 slot = htab_find_slot (ht, expr, INSERT);
8570 code = TREE_CODE (expr);
8571 if (code == SAVE_EXPR && SAVE_EXPR_NOPLACEHOLDER (expr))
8573 /* Allow SAVE_EXPR_NOPLACEHOLDER flag to be modified. */
8574 memcpy (buf, expr, tree_size (expr));
8576 SAVE_EXPR_NOPLACEHOLDER (expr) = 0;
8578 else if (TREE_CODE_CLASS (code) == 'd' && DECL_ASSEMBLER_NAME_SET_P (expr))
8580 /* Allow DECL_ASSEMBLER_NAME to be modified. */
8581 memcpy (buf, expr, tree_size (expr));
8583 SET_DECL_ASSEMBLER_NAME (expr, NULL);
8585 else if (TREE_CODE_CLASS (code) == 't'
8586 && (TYPE_POINTER_TO (expr) || TYPE_REFERENCE_TO (expr)))
8588 /* Allow TYPE_POINTER_TO and TYPE_REFERENCE_TO to be modified. */
8589 memcpy (buf, expr, tree_size (expr));
8591 TYPE_POINTER_TO (expr) = NULL;
8592 TYPE_REFERENCE_TO (expr) = NULL;
8594 md5_process_bytes (expr, tree_size (expr), ctx);
8595 fold_checksum_tree (TREE_TYPE (expr), ctx, ht);
8596 if (TREE_CODE_CLASS (code) != 't' && TREE_CODE_CLASS (code) != 'd')
8597 fold_checksum_tree (TREE_CHAIN (expr), ctx, ht);
8598 len = TREE_CODE_LENGTH (code);
8599 switch (TREE_CODE_CLASS (code))
8605 md5_process_bytes (TREE_STRING_POINTER (expr),
8606 TREE_STRING_LENGTH (expr), ctx);
8609 fold_checksum_tree (TREE_REALPART (expr), ctx, ht);
8610 fold_checksum_tree (TREE_IMAGPART (expr), ctx, ht);
8613 fold_checksum_tree (TREE_VECTOR_CST_ELTS (expr), ctx, ht);
8623 fold_checksum_tree (TREE_PURPOSE (expr), ctx, ht);
8624 fold_checksum_tree (TREE_VALUE (expr), ctx, ht);
8627 for (i = 0; i < TREE_VEC_LENGTH (expr); ++i)
8628 fold_checksum_tree (TREE_VEC_ELT (expr, i), ctx, ht);
8637 case SAVE_EXPR: len = 2; break;
8638 case GOTO_SUBROUTINE_EXPR: len = 0; break;
8639 case RTL_EXPR: len = 0; break;
8640 case WITH_CLEANUP_EXPR: len = 2; break;
8649 for (i = 0; i < len; ++i)
8650 fold_checksum_tree (TREE_OPERAND (expr, i), ctx, ht);
8653 fold_checksum_tree (DECL_SIZE (expr), ctx, ht);
8654 fold_checksum_tree (DECL_SIZE_UNIT (expr), ctx, ht);
8655 fold_checksum_tree (DECL_NAME (expr), ctx, ht);
8656 fold_checksum_tree (DECL_CONTEXT (expr), ctx, ht);
8657 fold_checksum_tree (DECL_ARGUMENTS (expr), ctx, ht);
8658 fold_checksum_tree (DECL_RESULT_FLD (expr), ctx, ht);
8659 fold_checksum_tree (DECL_INITIAL (expr), ctx, ht);
8660 fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr), ctx, ht);
8661 fold_checksum_tree (DECL_SECTION_NAME (expr), ctx, ht);
8662 fold_checksum_tree (DECL_ATTRIBUTES (expr), ctx, ht);
8663 fold_checksum_tree (DECL_VINDEX (expr), ctx, ht);
8666 fold_checksum_tree (TYPE_VALUES (expr), ctx, ht);
8667 fold_checksum_tree (TYPE_SIZE (expr), ctx, ht);
8668 fold_checksum_tree (TYPE_SIZE_UNIT (expr), ctx, ht);
8669 fold_checksum_tree (TYPE_ATTRIBUTES (expr), ctx, ht);
8670 fold_checksum_tree (TYPE_NAME (expr), ctx, ht);
8671 fold_checksum_tree (TYPE_MIN_VALUE (expr), ctx, ht);
8672 fold_checksum_tree (TYPE_MAX_VALUE (expr), ctx, ht);
8673 fold_checksum_tree (TYPE_MAIN_VARIANT (expr), ctx, ht);
8674 fold_checksum_tree (TYPE_BINFO (expr), ctx, ht);
8675 fold_checksum_tree (TYPE_CONTEXT (expr), ctx, ht);
8684 /* Perform constant folding and related simplification of initializer
8685 expression EXPR. This behaves identically to "fold" but ignores
8686 potential run-time traps and exceptions that fold must preserve. */
8689 fold_initializer (tree expr)
8691 int saved_signaling_nans = flag_signaling_nans;
8692 int saved_trapping_math = flag_trapping_math;
8693 int saved_trapv = flag_trapv;
8696 flag_signaling_nans = 0;
8697 flag_trapping_math = 0;
8700 result = fold (expr);
8702 flag_signaling_nans = saved_signaling_nans;
8703 flag_trapping_math = saved_trapping_math;
8704 flag_trapv = saved_trapv;
8709 /* Determine if first argument is a multiple of second argument. Return 0 if
8710 it is not, or we cannot easily determined it to be.
8712 An example of the sort of thing we care about (at this point; this routine
8713 could surely be made more general, and expanded to do what the *_DIV_EXPR's
8714 fold cases do now) is discovering that
8716 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
8722 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
8724 This code also handles discovering that
8726 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
8728 is a multiple of 8 so we don't have to worry about dealing with a
8731 Note that we *look* inside a SAVE_EXPR only to determine how it was
8732 calculated; it is not safe for fold to do much of anything else with the
8733 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
8734 at run time. For example, the latter example above *cannot* be implemented
8735 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
8736 evaluation time of the original SAVE_EXPR is not necessarily the same at
8737 the time the new expression is evaluated. The only optimization of this
8738 sort that would be valid is changing
8740 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
8744 SAVE_EXPR (I) * SAVE_EXPR (J)
8746 (where the same SAVE_EXPR (J) is used in the original and the
8747 transformed version). */
8750 multiple_of_p (tree type, tree top, tree bottom)
8752 if (operand_equal_p (top, bottom, 0))
8755 if (TREE_CODE (type) != INTEGER_TYPE)
8758 switch (TREE_CODE (top))
8761 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
8762 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
8766 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
8767 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
8770 if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
8774 op1 = TREE_OPERAND (top, 1);
8775 /* const_binop may not detect overflow correctly,
8776 so check for it explicitly here. */
8777 if (TYPE_PRECISION (TREE_TYPE (size_one_node))
8778 > TREE_INT_CST_LOW (op1)
8779 && TREE_INT_CST_HIGH (op1) == 0
8780 && 0 != (t1 = fold_convert (type,
8781 const_binop (LSHIFT_EXPR,
8784 && ! TREE_OVERFLOW (t1))
8785 return multiple_of_p (type, t1, bottom);
8790 /* Can't handle conversions from non-integral or wider integral type. */
8791 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
8792 || (TYPE_PRECISION (type)
8793 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
8796 /* .. fall through ... */
8799 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
8802 if (TREE_CODE (bottom) != INTEGER_CST
8803 || (TREE_UNSIGNED (type)
8804 && (tree_int_cst_sgn (top) < 0
8805 || tree_int_cst_sgn (bottom) < 0)))
8807 return integer_zerop (const_binop (TRUNC_MOD_EXPR,
8815 /* Return true if `t' is known to be non-negative. */
8818 tree_expr_nonnegative_p (tree t)
8820 switch (TREE_CODE (t))
8826 return tree_int_cst_sgn (t) >= 0;
8829 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
8832 if (FLOAT_TYPE_P (TREE_TYPE (t)))
8833 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8834 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8836 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
8837 both unsigned and at least 2 bits shorter than the result. */
8838 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
8839 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
8840 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
8842 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
8843 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
8844 if (TREE_CODE (inner1) == INTEGER_TYPE && TREE_UNSIGNED (inner1)
8845 && TREE_CODE (inner2) == INTEGER_TYPE && TREE_UNSIGNED (inner2))
8847 unsigned int prec = MAX (TYPE_PRECISION (inner1),
8848 TYPE_PRECISION (inner2)) + 1;
8849 return prec < TYPE_PRECISION (TREE_TYPE (t));
8855 if (FLOAT_TYPE_P (TREE_TYPE (t)))
8857 /* x * x for floating point x is always non-negative. */
8858 if (operand_equal_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1), 0))
8860 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8861 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8864 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
8865 both unsigned and their total bits is shorter than the result. */
8866 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
8867 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
8868 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
8870 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
8871 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
8872 if (TREE_CODE (inner1) == INTEGER_TYPE && TREE_UNSIGNED (inner1)
8873 && TREE_CODE (inner2) == INTEGER_TYPE && TREE_UNSIGNED (inner2))
8874 return TYPE_PRECISION (inner1) + TYPE_PRECISION (inner2)
8875 < TYPE_PRECISION (TREE_TYPE (t));
8879 case TRUNC_DIV_EXPR:
8881 case FLOOR_DIV_EXPR:
8882 case ROUND_DIV_EXPR:
8883 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8884 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8886 case TRUNC_MOD_EXPR:
8888 case FLOOR_MOD_EXPR:
8889 case ROUND_MOD_EXPR:
8890 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8893 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8894 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8898 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
8899 tree outer_type = TREE_TYPE (t);
8901 if (TREE_CODE (outer_type) == REAL_TYPE)
8903 if (TREE_CODE (inner_type) == REAL_TYPE)
8904 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8905 if (TREE_CODE (inner_type) == INTEGER_TYPE)
8907 if (TREE_UNSIGNED (inner_type))
8909 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8912 else if (TREE_CODE (outer_type) == INTEGER_TYPE)
8914 if (TREE_CODE (inner_type) == REAL_TYPE)
8915 return tree_expr_nonnegative_p (TREE_OPERAND (t,0));
8916 if (TREE_CODE (inner_type) == INTEGER_TYPE)
8917 return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
8918 && TREE_UNSIGNED (inner_type);
8924 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
8925 && tree_expr_nonnegative_p (TREE_OPERAND (t, 2));
8927 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8929 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8930 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8932 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8933 || tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8935 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8937 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8939 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8940 case NON_LVALUE_EXPR:
8941 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8943 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8945 return rtl_expr_nonnegative_p (RTL_EXPR_RTL (t));
8949 tree fndecl = get_callee_fndecl (t);
8950 tree arglist = TREE_OPERAND (t, 1);
8952 && DECL_BUILT_IN (fndecl)
8953 && DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_MD)
8954 switch (DECL_FUNCTION_CODE (fndecl))
8957 case BUILT_IN_CABSL:
8958 case BUILT_IN_CABSF:
8963 case BUILT_IN_EXP2F:
8964 case BUILT_IN_EXP2L:
8965 case BUILT_IN_EXP10:
8966 case BUILT_IN_EXP10F:
8967 case BUILT_IN_EXP10L:
8969 case BUILT_IN_FABSF:
8970 case BUILT_IN_FABSL:
8973 case BUILT_IN_FFSLL:
8974 case BUILT_IN_PARITY:
8975 case BUILT_IN_PARITYL:
8976 case BUILT_IN_PARITYLL:
8977 case BUILT_IN_POPCOUNT:
8978 case BUILT_IN_POPCOUNTL:
8979 case BUILT_IN_POPCOUNTLL:
8980 case BUILT_IN_POW10:
8981 case BUILT_IN_POW10F:
8982 case BUILT_IN_POW10L:
8984 case BUILT_IN_SQRTF:
8985 case BUILT_IN_SQRTL:
8989 case BUILT_IN_ATANF:
8990 case BUILT_IN_ATANL:
8992 case BUILT_IN_CEILF:
8993 case BUILT_IN_CEILL:
8994 case BUILT_IN_FLOOR:
8995 case BUILT_IN_FLOORF:
8996 case BUILT_IN_FLOORL:
8997 case BUILT_IN_NEARBYINT:
8998 case BUILT_IN_NEARBYINTF:
8999 case BUILT_IN_NEARBYINTL:
9000 case BUILT_IN_ROUND:
9001 case BUILT_IN_ROUNDF:
9002 case BUILT_IN_ROUNDL:
9003 case BUILT_IN_TRUNC:
9004 case BUILT_IN_TRUNCF:
9005 case BUILT_IN_TRUNCL:
9006 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
9011 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
9018 /* ... fall through ... */
9021 if (truth_value_p (TREE_CODE (t)))
9022 /* Truth values evaluate to 0 or 1, which is nonnegative. */
9026 /* We don't know sign of `t', so be conservative and return false. */
9030 /* Return true if `r' is known to be non-negative.
9031 Only handles constants at the moment. */
9034 rtl_expr_nonnegative_p (rtx r)
9036 switch (GET_CODE (r))
9039 return INTVAL (r) >= 0;
9042 if (GET_MODE (r) == VOIDmode)
9043 return CONST_DOUBLE_HIGH (r) >= 0;
9051 units = CONST_VECTOR_NUNITS (r);
9053 for (i = 0; i < units; ++i)
9055 elt = CONST_VECTOR_ELT (r, i);
9056 if (!rtl_expr_nonnegative_p (elt))
9065 /* These are always nonnegative. */
9073 #include "gt-fold-const.h"