1 /* Fold a constant sub-tree into a single node for C-compiler
2 Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
3 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
22 /*@@ This file should be rewritten to use an arbitrary precision
23 @@ representation for "struct tree_int_cst" and "struct tree_real_cst".
24 @@ Perhaps the routines could also be used for bc/dc, and made a lib.
25 @@ The routines that translate from the ap rep should
26 @@ warn if precision et. al. is lost.
27 @@ This would also make life easier when this technology is used
28 @@ for cross-compilers. */
30 /* The entry points in this file are fold, size_int_wide, size_binop
33 fold takes a tree as argument and returns a simplified tree.
35 size_binop takes a tree code for an arithmetic operation
36 and two operands that are trees, and produces a tree for the
37 result, assuming the type comes from `sizetype'.
39 size_int takes an integer value, and creates a tree constant
40 with type from `sizetype'.
42 force_fit_type takes a constant and prior overflow indicator, and
43 forces the value to fit the type. It returns an overflow indicator. */
47 #include "coretypes.h"
58 #include "langhooks.h"
60 static void encode PARAMS ((HOST_WIDE_INT *,
61 unsigned HOST_WIDE_INT,
63 static void decode PARAMS ((HOST_WIDE_INT *,
64 unsigned HOST_WIDE_INT *,
66 static bool negate_expr_p PARAMS ((tree));
67 static tree negate_expr PARAMS ((tree));
68 static tree split_tree PARAMS ((tree, enum tree_code, tree *, tree *,
70 static tree associate_trees PARAMS ((tree, tree, enum tree_code, tree));
71 static tree int_const_binop PARAMS ((enum tree_code, tree, tree, int));
72 static tree const_binop PARAMS ((enum tree_code, tree, tree, int));
73 static hashval_t size_htab_hash PARAMS ((const void *));
74 static int size_htab_eq PARAMS ((const void *, const void *));
75 static tree fold_convert PARAMS ((tree, tree));
76 static enum tree_code invert_tree_comparison PARAMS ((enum tree_code));
77 static enum tree_code swap_tree_comparison PARAMS ((enum tree_code));
78 static int comparison_to_compcode PARAMS ((enum tree_code));
79 static enum tree_code compcode_to_comparison PARAMS ((int));
80 static int truth_value_p PARAMS ((enum tree_code));
81 static int operand_equal_for_comparison_p PARAMS ((tree, tree, tree));
82 static int twoval_comparison_p PARAMS ((tree, tree *, tree *, int *));
83 static tree eval_subst PARAMS ((tree, tree, tree, tree, tree));
84 static tree pedantic_omit_one_operand PARAMS ((tree, tree, tree));
85 static tree distribute_bit_expr PARAMS ((enum tree_code, tree, tree, tree));
86 static tree make_bit_field_ref PARAMS ((tree, tree, int, int, int));
87 static tree optimize_bit_field_compare PARAMS ((enum tree_code, tree,
89 static tree decode_field_reference PARAMS ((tree, HOST_WIDE_INT *,
91 enum machine_mode *, int *,
92 int *, tree *, tree *));
93 static int all_ones_mask_p PARAMS ((tree, int));
94 static tree sign_bit_p PARAMS ((tree, tree));
95 static int simple_operand_p PARAMS ((tree));
96 static tree range_binop PARAMS ((enum tree_code, tree, tree, int,
98 static tree make_range PARAMS ((tree, int *, tree *, tree *));
99 static tree build_range_check PARAMS ((tree, tree, int, tree, tree));
100 static int merge_ranges PARAMS ((int *, tree *, tree *, int, tree, tree,
102 static tree fold_range_test PARAMS ((tree));
103 static tree unextend PARAMS ((tree, int, int, tree));
104 static tree fold_truthop PARAMS ((enum tree_code, tree, tree, tree));
105 static tree optimize_minmax_comparison PARAMS ((tree));
106 static tree extract_muldiv PARAMS ((tree, tree, enum tree_code, tree));
107 static tree extract_muldiv_1 PARAMS ((tree, tree, enum tree_code, tree));
108 static tree strip_compound_expr PARAMS ((tree, tree));
109 static int multiple_of_p PARAMS ((tree, tree, tree));
110 static tree constant_boolean_node PARAMS ((int, tree));
111 static int count_cond PARAMS ((tree, int));
112 static tree fold_binary_op_with_conditional_arg
113 PARAMS ((enum tree_code, tree, tree, tree, int));
114 static bool fold_real_zero_addition_p PARAMS ((tree, tree, int));
115 static tree fold_mathfn_compare PARAMS ((enum built_in_function,
116 enum tree_code, tree, tree, tree));
117 static tree fold_inf_compare PARAMS ((enum tree_code, tree, tree, tree));
119 /* The following constants represent a bit based encoding of GCC's
120 comparison operators. This encoding simplifies transformations
121 on relational comparison operators, such as AND and OR. */
122 #define COMPCODE_FALSE 0
123 #define COMPCODE_LT 1
124 #define COMPCODE_EQ 2
125 #define COMPCODE_LE 3
126 #define COMPCODE_GT 4
127 #define COMPCODE_NE 5
128 #define COMPCODE_GE 6
129 #define COMPCODE_TRUE 7
131 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
132 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
133 and SUM1. Then this yields nonzero if overflow occurred during the
136 Overflow occurs if A and B have the same sign, but A and SUM differ in
137 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
139 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
141 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
142 We do that by representing the two-word integer in 4 words, with only
143 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
144 number. The value of the word is LOWPART + HIGHPART * BASE. */
147 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
148 #define HIGHPART(x) \
149 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
150 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
152 /* Unpack a two-word integer into 4 words.
153 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
154 WORDS points to the array of HOST_WIDE_INTs. */
157 encode (words, low, hi)
158 HOST_WIDE_INT *words;
159 unsigned HOST_WIDE_INT low;
162 words[0] = LOWPART (low);
163 words[1] = HIGHPART (low);
164 words[2] = LOWPART (hi);
165 words[3] = HIGHPART (hi);
168 /* Pack an array of 4 words into a two-word integer.
169 WORDS points to the array of words.
170 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
173 decode (words, low, hi)
174 HOST_WIDE_INT *words;
175 unsigned HOST_WIDE_INT *low;
178 *low = words[0] + words[1] * BASE;
179 *hi = words[2] + words[3] * BASE;
182 /* Make the integer constant T valid for its type by setting to 0 or 1 all
183 the bits in the constant that don't belong in the type.
185 Return 1 if a signed overflow occurs, 0 otherwise. If OVERFLOW is
186 nonzero, a signed overflow has already occurred in calculating T, so
190 force_fit_type (t, overflow)
194 unsigned HOST_WIDE_INT low;
198 if (TREE_CODE (t) == REAL_CST)
200 /* ??? Used to check for overflow here via CHECK_FLOAT_TYPE.
201 Consider doing it via real_convert now. */
205 else if (TREE_CODE (t) != INTEGER_CST)
208 low = TREE_INT_CST_LOW (t);
209 high = TREE_INT_CST_HIGH (t);
211 if (POINTER_TYPE_P (TREE_TYPE (t)))
214 prec = TYPE_PRECISION (TREE_TYPE (t));
216 /* First clear all bits that are beyond the type's precision. */
218 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
220 else if (prec > HOST_BITS_PER_WIDE_INT)
221 TREE_INT_CST_HIGH (t)
222 &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
225 TREE_INT_CST_HIGH (t) = 0;
226 if (prec < HOST_BITS_PER_WIDE_INT)
227 TREE_INT_CST_LOW (t) &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
230 /* Unsigned types do not suffer sign extension or overflow unless they
232 if (TREE_UNSIGNED (TREE_TYPE (t))
233 && ! (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
234 && TYPE_IS_SIZETYPE (TREE_TYPE (t))))
237 /* If the value's sign bit is set, extend the sign. */
238 if (prec != 2 * HOST_BITS_PER_WIDE_INT
239 && (prec > HOST_BITS_PER_WIDE_INT
240 ? 0 != (TREE_INT_CST_HIGH (t)
242 << (prec - HOST_BITS_PER_WIDE_INT - 1)))
243 : 0 != (TREE_INT_CST_LOW (t)
244 & ((unsigned HOST_WIDE_INT) 1 << (prec - 1)))))
246 /* Value is negative:
247 set to 1 all the bits that are outside this type's precision. */
248 if (prec > HOST_BITS_PER_WIDE_INT)
249 TREE_INT_CST_HIGH (t)
250 |= ((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
253 TREE_INT_CST_HIGH (t) = -1;
254 if (prec < HOST_BITS_PER_WIDE_INT)
255 TREE_INT_CST_LOW (t) |= ((unsigned HOST_WIDE_INT) (-1) << prec);
259 /* Return nonzero if signed overflow occurred. */
261 ((overflow | (low ^ TREE_INT_CST_LOW (t)) | (high ^ TREE_INT_CST_HIGH (t)))
265 /* Add two doubleword integers with doubleword result.
266 Each argument is given as two `HOST_WIDE_INT' pieces.
267 One argument is L1 and H1; the other, L2 and H2.
268 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
271 add_double (l1, h1, l2, h2, lv, hv)
272 unsigned HOST_WIDE_INT l1, l2;
273 HOST_WIDE_INT h1, h2;
274 unsigned HOST_WIDE_INT *lv;
277 unsigned HOST_WIDE_INT l;
281 h = h1 + h2 + (l < l1);
285 return OVERFLOW_SUM_SIGN (h1, h2, h);
288 /* Negate a doubleword integer with doubleword result.
289 Return nonzero if the operation overflows, assuming it's signed.
290 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
291 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
294 neg_double (l1, h1, lv, hv)
295 unsigned HOST_WIDE_INT l1;
297 unsigned HOST_WIDE_INT *lv;
304 return (*hv & h1) < 0;
314 /* Multiply two doubleword integers with doubleword result.
315 Return nonzero if the operation overflows, assuming it's signed.
316 Each argument is given as two `HOST_WIDE_INT' pieces.
317 One argument is L1 and H1; the other, L2 and H2.
318 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
321 mul_double (l1, h1, l2, h2, lv, hv)
322 unsigned HOST_WIDE_INT l1, l2;
323 HOST_WIDE_INT h1, h2;
324 unsigned HOST_WIDE_INT *lv;
327 HOST_WIDE_INT arg1[4];
328 HOST_WIDE_INT arg2[4];
329 HOST_WIDE_INT prod[4 * 2];
330 unsigned HOST_WIDE_INT carry;
332 unsigned HOST_WIDE_INT toplow, neglow;
333 HOST_WIDE_INT tophigh, neghigh;
335 encode (arg1, l1, h1);
336 encode (arg2, l2, h2);
338 memset ((char *) prod, 0, sizeof prod);
340 for (i = 0; i < 4; i++)
343 for (j = 0; j < 4; j++)
346 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
347 carry += arg1[i] * arg2[j];
348 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
350 prod[k] = LOWPART (carry);
351 carry = HIGHPART (carry);
356 decode (prod, lv, hv); /* This ignores prod[4] through prod[4*2-1] */
358 /* Check for overflow by calculating the top half of the answer in full;
359 it should agree with the low half's sign bit. */
360 decode (prod + 4, &toplow, &tophigh);
363 neg_double (l2, h2, &neglow, &neghigh);
364 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
368 neg_double (l1, h1, &neglow, &neghigh);
369 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
371 return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
374 /* Shift the doubleword integer in L1, H1 left by COUNT places
375 keeping only PREC bits of result.
376 Shift right if COUNT is negative.
377 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
378 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
381 lshift_double (l1, h1, count, prec, lv, hv, arith)
382 unsigned HOST_WIDE_INT l1;
383 HOST_WIDE_INT h1, count;
385 unsigned HOST_WIDE_INT *lv;
389 unsigned HOST_WIDE_INT signmask;
393 rshift_double (l1, h1, -count, prec, lv, hv, arith);
397 #ifdef SHIFT_COUNT_TRUNCATED
398 if (SHIFT_COUNT_TRUNCATED)
402 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
404 /* Shifting by the host word size is undefined according to the
405 ANSI standard, so we must handle this as a special case. */
409 else if (count >= HOST_BITS_PER_WIDE_INT)
411 *hv = l1 << (count - HOST_BITS_PER_WIDE_INT);
416 *hv = (((unsigned HOST_WIDE_INT) h1 << count)
417 | (l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
421 /* Sign extend all bits that are beyond the precision. */
423 signmask = -((prec > HOST_BITS_PER_WIDE_INT
424 ? ((unsigned HOST_WIDE_INT) *hv
425 >> (prec - HOST_BITS_PER_WIDE_INT - 1))
426 : (*lv >> (prec - 1))) & 1);
428 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
430 else if (prec >= HOST_BITS_PER_WIDE_INT)
432 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
433 *hv |= signmask << (prec - HOST_BITS_PER_WIDE_INT);
438 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
439 *lv |= signmask << prec;
443 /* Shift the doubleword integer in L1, H1 right by COUNT places
444 keeping only PREC bits of result. COUNT must be positive.
445 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
446 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
449 rshift_double (l1, h1, count, prec, lv, hv, arith)
450 unsigned HOST_WIDE_INT l1;
451 HOST_WIDE_INT h1, count;
453 unsigned HOST_WIDE_INT *lv;
457 unsigned HOST_WIDE_INT signmask;
460 ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
463 #ifdef SHIFT_COUNT_TRUNCATED
464 if (SHIFT_COUNT_TRUNCATED)
468 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
470 /* Shifting by the host word size is undefined according to the
471 ANSI standard, so we must handle this as a special case. */
475 else if (count >= HOST_BITS_PER_WIDE_INT)
478 *lv = (unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT);
482 *hv = (unsigned HOST_WIDE_INT) h1 >> count;
484 | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
487 /* Zero / sign extend all bits that are beyond the precision. */
489 if (count >= (HOST_WIDE_INT)prec)
494 else if ((prec - count) >= 2 * HOST_BITS_PER_WIDE_INT)
496 else if ((prec - count) >= HOST_BITS_PER_WIDE_INT)
498 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - count - HOST_BITS_PER_WIDE_INT));
499 *hv |= signmask << (prec - count - HOST_BITS_PER_WIDE_INT);
504 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << (prec - count));
505 *lv |= signmask << (prec - count);
509 /* Rotate the doubleword integer in L1, H1 left by COUNT places
510 keeping only PREC bits of result.
511 Rotate right if COUNT is negative.
512 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
515 lrotate_double (l1, h1, count, prec, lv, hv)
516 unsigned HOST_WIDE_INT l1;
517 HOST_WIDE_INT h1, count;
519 unsigned HOST_WIDE_INT *lv;
522 unsigned HOST_WIDE_INT s1l, s2l;
523 HOST_WIDE_INT s1h, s2h;
529 lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
530 rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
535 /* Rotate the doubleword integer in L1, H1 left by COUNT places
536 keeping only PREC bits of result. COUNT must be positive.
537 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
540 rrotate_double (l1, h1, count, prec, lv, hv)
541 unsigned HOST_WIDE_INT l1;
542 HOST_WIDE_INT h1, count;
544 unsigned HOST_WIDE_INT *lv;
547 unsigned HOST_WIDE_INT s1l, s2l;
548 HOST_WIDE_INT s1h, s2h;
554 rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
555 lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
560 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
561 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
562 CODE is a tree code for a kind of division, one of
563 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
565 It controls how the quotient is rounded to an integer.
566 Return nonzero if the operation overflows.
567 UNS nonzero says do unsigned division. */
570 div_and_round_double (code, uns,
571 lnum_orig, hnum_orig, lden_orig, hden_orig,
572 lquo, hquo, lrem, hrem)
575 unsigned HOST_WIDE_INT lnum_orig; /* num == numerator == dividend */
576 HOST_WIDE_INT hnum_orig;
577 unsigned HOST_WIDE_INT lden_orig; /* den == denominator == divisor */
578 HOST_WIDE_INT hden_orig;
579 unsigned HOST_WIDE_INT *lquo, *lrem;
580 HOST_WIDE_INT *hquo, *hrem;
583 HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
584 HOST_WIDE_INT den[4], quo[4];
586 unsigned HOST_WIDE_INT work;
587 unsigned HOST_WIDE_INT carry = 0;
588 unsigned HOST_WIDE_INT lnum = lnum_orig;
589 HOST_WIDE_INT hnum = hnum_orig;
590 unsigned HOST_WIDE_INT lden = lden_orig;
591 HOST_WIDE_INT hden = hden_orig;
594 if (hden == 0 && lden == 0)
595 overflow = 1, lden = 1;
597 /* calculate quotient sign and convert operands to unsigned. */
603 /* (minimum integer) / (-1) is the only overflow case. */
604 if (neg_double (lnum, hnum, &lnum, &hnum)
605 && ((HOST_WIDE_INT) lden & hden) == -1)
611 neg_double (lden, hden, &lden, &hden);
615 if (hnum == 0 && hden == 0)
616 { /* single precision */
618 /* This unsigned division rounds toward zero. */
624 { /* trivial case: dividend < divisor */
625 /* hden != 0 already checked. */
632 memset ((char *) quo, 0, sizeof quo);
634 memset ((char *) num, 0, sizeof num); /* to zero 9th element */
635 memset ((char *) den, 0, sizeof den);
637 encode (num, lnum, hnum);
638 encode (den, lden, hden);
640 /* Special code for when the divisor < BASE. */
641 if (hden == 0 && lden < (unsigned HOST_WIDE_INT) BASE)
643 /* hnum != 0 already checked. */
644 for (i = 4 - 1; i >= 0; i--)
646 work = num[i] + carry * BASE;
647 quo[i] = work / lden;
653 /* Full double precision division,
654 with thanks to Don Knuth's "Seminumerical Algorithms". */
655 int num_hi_sig, den_hi_sig;
656 unsigned HOST_WIDE_INT quo_est, scale;
658 /* Find the highest nonzero divisor digit. */
659 for (i = 4 - 1;; i--)
666 /* Insure that the first digit of the divisor is at least BASE/2.
667 This is required by the quotient digit estimation algorithm. */
669 scale = BASE / (den[den_hi_sig] + 1);
671 { /* scale divisor and dividend */
673 for (i = 0; i <= 4 - 1; i++)
675 work = (num[i] * scale) + carry;
676 num[i] = LOWPART (work);
677 carry = HIGHPART (work);
682 for (i = 0; i <= 4 - 1; i++)
684 work = (den[i] * scale) + carry;
685 den[i] = LOWPART (work);
686 carry = HIGHPART (work);
687 if (den[i] != 0) den_hi_sig = i;
694 for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--)
696 /* Guess the next quotient digit, quo_est, by dividing the first
697 two remaining dividend digits by the high order quotient digit.
698 quo_est is never low and is at most 2 high. */
699 unsigned HOST_WIDE_INT tmp;
701 num_hi_sig = i + den_hi_sig + 1;
702 work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
703 if (num[num_hi_sig] != den[den_hi_sig])
704 quo_est = work / den[den_hi_sig];
708 /* Refine quo_est so it's usually correct, and at most one high. */
709 tmp = work - quo_est * den[den_hi_sig];
711 && (den[den_hi_sig - 1] * quo_est
712 > (tmp * BASE + num[num_hi_sig - 2])))
715 /* Try QUO_EST as the quotient digit, by multiplying the
716 divisor by QUO_EST and subtracting from the remaining dividend.
717 Keep in mind that QUO_EST is the I - 1st digit. */
720 for (j = 0; j <= den_hi_sig; j++)
722 work = quo_est * den[j] + carry;
723 carry = HIGHPART (work);
724 work = num[i + j] - LOWPART (work);
725 num[i + j] = LOWPART (work);
726 carry += HIGHPART (work) != 0;
729 /* If quo_est was high by one, then num[i] went negative and
730 we need to correct things. */
731 if (num[num_hi_sig] < (HOST_WIDE_INT) carry)
734 carry = 0; /* add divisor back in */
735 for (j = 0; j <= den_hi_sig; j++)
737 work = num[i + j] + den[j] + carry;
738 carry = HIGHPART (work);
739 num[i + j] = LOWPART (work);
742 num [num_hi_sig] += carry;
745 /* Store the quotient digit. */
750 decode (quo, lquo, hquo);
753 /* if result is negative, make it so. */
755 neg_double (*lquo, *hquo, lquo, hquo);
757 /* compute trial remainder: rem = num - (quo * den) */
758 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
759 neg_double (*lrem, *hrem, lrem, hrem);
760 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
765 case TRUNC_MOD_EXPR: /* round toward zero */
766 case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
770 case FLOOR_MOD_EXPR: /* round toward negative infinity */
771 if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
774 add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
782 case CEIL_MOD_EXPR: /* round toward positive infinity */
783 if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
785 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
793 case ROUND_MOD_EXPR: /* round to closest integer */
795 unsigned HOST_WIDE_INT labs_rem = *lrem;
796 HOST_WIDE_INT habs_rem = *hrem;
797 unsigned HOST_WIDE_INT labs_den = lden, ltwice;
798 HOST_WIDE_INT habs_den = hden, htwice;
800 /* Get absolute values */
802 neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
804 neg_double (lden, hden, &labs_den, &habs_den);
806 /* If (2 * abs (lrem) >= abs (lden)) */
807 mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
808 labs_rem, habs_rem, <wice, &htwice);
810 if (((unsigned HOST_WIDE_INT) habs_den
811 < (unsigned HOST_WIDE_INT) htwice)
812 || (((unsigned HOST_WIDE_INT) habs_den
813 == (unsigned HOST_WIDE_INT) htwice)
814 && (labs_den < ltwice)))
818 add_double (*lquo, *hquo,
819 (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
822 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
834 /* compute true remainder: rem = num - (quo * den) */
835 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
836 neg_double (*lrem, *hrem, lrem, hrem);
837 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
841 /* Determine whether an expression T can be cheaply negated using
842 the function negate_expr. */
848 unsigned HOST_WIDE_INT val;
855 type = TREE_TYPE (t);
858 switch (TREE_CODE (t))
861 if (TREE_UNSIGNED (type))
864 /* Check that -CST will not overflow type. */
865 prec = TYPE_PRECISION (type);
866 if (prec > HOST_BITS_PER_WIDE_INT)
868 if (TREE_INT_CST_LOW (t) != 0)
870 prec -= HOST_BITS_PER_WIDE_INT;
871 val = TREE_INT_CST_HIGH (t);
874 val = TREE_INT_CST_LOW (t);
875 if (prec < HOST_BITS_PER_WIDE_INT)
876 val &= ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
877 return val != ((unsigned HOST_WIDE_INT) 1 << (prec - 1));
890 /* Given T, an expression, return the negation of T. Allow for T to be
891 null, in which case return null. */
903 type = TREE_TYPE (t);
906 switch (TREE_CODE (t))
910 if (! TREE_UNSIGNED (type)
911 && 0 != (tem = fold (build1 (NEGATE_EXPR, type, t)))
912 && ! TREE_OVERFLOW (tem))
917 return convert (type, TREE_OPERAND (t, 0));
920 /* - (A - B) -> B - A */
921 if (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
922 return convert (type,
923 fold (build (MINUS_EXPR, TREE_TYPE (t),
925 TREE_OPERAND (t, 0))));
932 return convert (type, fold (build1 (NEGATE_EXPR, TREE_TYPE (t), t)));
935 /* Split a tree IN into a constant, literal and variable parts that could be
936 combined with CODE to make IN. "constant" means an expression with
937 TREE_CONSTANT but that isn't an actual constant. CODE must be a
938 commutative arithmetic operation. Store the constant part into *CONP,
939 the literal in *LITP and return the variable part. If a part isn't
940 present, set it to null. If the tree does not decompose in this way,
941 return the entire tree as the variable part and the other parts as null.
943 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
944 case, we negate an operand that was subtracted. Except if it is a
945 literal for which we use *MINUS_LITP instead.
947 If NEGATE_P is true, we are negating all of IN, again except a literal
948 for which we use *MINUS_LITP instead.
950 If IN is itself a literal or constant, return it as appropriate.
952 Note that we do not guarantee that any of the three values will be the
953 same type as IN, but they will have the same signedness and mode. */
956 split_tree (in, code, conp, litp, minus_litp, negate_p)
959 tree *conp, *litp, *minus_litp;
968 /* Strip any conversions that don't change the machine mode or signedness. */
969 STRIP_SIGN_NOPS (in);
971 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST)
973 else if (TREE_CODE (in) == code
974 || (! FLOAT_TYPE_P (TREE_TYPE (in))
975 /* We can associate addition and subtraction together (even
976 though the C standard doesn't say so) for integers because
977 the value is not affected. For reals, the value might be
978 affected, so we can't. */
979 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
980 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
982 tree op0 = TREE_OPERAND (in, 0);
983 tree op1 = TREE_OPERAND (in, 1);
984 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
985 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
987 /* First see if either of the operands is a literal, then a constant. */
988 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
989 *litp = op0, op0 = 0;
990 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST)
991 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
993 if (op0 != 0 && TREE_CONSTANT (op0))
994 *conp = op0, op0 = 0;
995 else if (op1 != 0 && TREE_CONSTANT (op1))
996 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
998 /* If we haven't dealt with either operand, this is not a case we can
999 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1000 if (op0 != 0 && op1 != 0)
1005 var = op1, neg_var_p = neg1_p;
1007 /* Now do any needed negations. */
1009 *minus_litp = *litp, *litp = 0;
1011 *conp = negate_expr (*conp);
1013 var = negate_expr (var);
1015 else if (TREE_CONSTANT (in))
1023 *minus_litp = *litp, *litp = 0;
1024 else if (*minus_litp)
1025 *litp = *minus_litp, *minus_litp = 0;
1026 *conp = negate_expr (*conp);
1027 var = negate_expr (var);
1033 /* Re-associate trees split by the above function. T1 and T2 are either
1034 expressions to associate or null. Return the new expression, if any. If
1035 we build an operation, do it in TYPE and with CODE. */
1038 associate_trees (t1, t2, code, type)
1040 enum tree_code code;
1048 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1049 try to fold this since we will have infinite recursion. But do
1050 deal with any NEGATE_EXPRs. */
1051 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
1052 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1054 if (code == PLUS_EXPR)
1056 if (TREE_CODE (t1) == NEGATE_EXPR)
1057 return build (MINUS_EXPR, type, convert (type, t2),
1058 convert (type, TREE_OPERAND (t1, 0)));
1059 else if (TREE_CODE (t2) == NEGATE_EXPR)
1060 return build (MINUS_EXPR, type, convert (type, t1),
1061 convert (type, TREE_OPERAND (t2, 0)));
1063 return build (code, type, convert (type, t1), convert (type, t2));
1066 return fold (build (code, type, convert (type, t1), convert (type, t2)));
1069 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1070 to produce a new constant.
1072 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1075 int_const_binop (code, arg1, arg2, notrunc)
1076 enum tree_code code;
1080 unsigned HOST_WIDE_INT int1l, int2l;
1081 HOST_WIDE_INT int1h, int2h;
1082 unsigned HOST_WIDE_INT low;
1084 unsigned HOST_WIDE_INT garbagel;
1085 HOST_WIDE_INT garbageh;
1087 tree type = TREE_TYPE (arg1);
1088 int uns = TREE_UNSIGNED (type);
1090 = (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type));
1092 int no_overflow = 0;
1094 int1l = TREE_INT_CST_LOW (arg1);
1095 int1h = TREE_INT_CST_HIGH (arg1);
1096 int2l = TREE_INT_CST_LOW (arg2);
1097 int2h = TREE_INT_CST_HIGH (arg2);
1102 low = int1l | int2l, hi = int1h | int2h;
1106 low = int1l ^ int2l, hi = int1h ^ int2h;
1110 low = int1l & int2l, hi = int1h & int2h;
1113 case BIT_ANDTC_EXPR:
1114 low = int1l & ~int2l, hi = int1h & ~int2h;
1120 /* It's unclear from the C standard whether shifts can overflow.
1121 The following code ignores overflow; perhaps a C standard
1122 interpretation ruling is needed. */
1123 lshift_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1131 lrotate_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1136 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1140 neg_double (int2l, int2h, &low, &hi);
1141 add_double (int1l, int1h, low, hi, &low, &hi);
1142 overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
1146 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1149 case TRUNC_DIV_EXPR:
1150 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1151 case EXACT_DIV_EXPR:
1152 /* This is a shortcut for a common special case. */
1153 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1154 && ! TREE_CONSTANT_OVERFLOW (arg1)
1155 && ! TREE_CONSTANT_OVERFLOW (arg2)
1156 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1158 if (code == CEIL_DIV_EXPR)
1161 low = int1l / int2l, hi = 0;
1165 /* ... fall through ... */
1167 case ROUND_DIV_EXPR:
1168 if (int2h == 0 && int2l == 1)
1170 low = int1l, hi = int1h;
1173 if (int1l == int2l && int1h == int2h
1174 && ! (int1l == 0 && int1h == 0))
1179 overflow = div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
1180 &low, &hi, &garbagel, &garbageh);
1183 case TRUNC_MOD_EXPR:
1184 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1185 /* This is a shortcut for a common special case. */
1186 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1187 && ! TREE_CONSTANT_OVERFLOW (arg1)
1188 && ! TREE_CONSTANT_OVERFLOW (arg2)
1189 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1191 if (code == CEIL_MOD_EXPR)
1193 low = int1l % int2l, hi = 0;
1197 /* ... fall through ... */
1199 case ROUND_MOD_EXPR:
1200 overflow = div_and_round_double (code, uns,
1201 int1l, int1h, int2l, int2h,
1202 &garbagel, &garbageh, &low, &hi);
1208 low = (((unsigned HOST_WIDE_INT) int1h
1209 < (unsigned HOST_WIDE_INT) int2h)
1210 || (((unsigned HOST_WIDE_INT) int1h
1211 == (unsigned HOST_WIDE_INT) int2h)
1214 low = (int1h < int2h
1215 || (int1h == int2h && int1l < int2l));
1217 if (low == (code == MIN_EXPR))
1218 low = int1l, hi = int1h;
1220 low = int2l, hi = int2h;
1227 /* If this is for a sizetype, can be represented as one (signed)
1228 HOST_WIDE_INT word, and doesn't overflow, use size_int since it caches
1231 && ((hi == 0 && (HOST_WIDE_INT) low >= 0)
1232 || (hi == -1 && (HOST_WIDE_INT) low < 0))
1233 && overflow == 0 && ! TREE_OVERFLOW (arg1) && ! TREE_OVERFLOW (arg2))
1234 return size_int_type_wide (low, type);
1237 t = build_int_2 (low, hi);
1238 TREE_TYPE (t) = TREE_TYPE (arg1);
1243 ? (!uns || is_sizetype) && overflow
1244 : (force_fit_type (t, (!uns || is_sizetype) && overflow)
1246 | TREE_OVERFLOW (arg1)
1247 | TREE_OVERFLOW (arg2));
1249 /* If we're doing a size calculation, unsigned arithmetic does overflow.
1250 So check if force_fit_type truncated the value. */
1252 && ! TREE_OVERFLOW (t)
1253 && (TREE_INT_CST_HIGH (t) != hi
1254 || TREE_INT_CST_LOW (t) != low))
1255 TREE_OVERFLOW (t) = 1;
1257 TREE_CONSTANT_OVERFLOW (t) = (TREE_OVERFLOW (t)
1258 | TREE_CONSTANT_OVERFLOW (arg1)
1259 | TREE_CONSTANT_OVERFLOW (arg2));
1263 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1264 constant. We assume ARG1 and ARG2 have the same data type, or at least
1265 are the same kind of constant and the same machine mode.
1267 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1270 const_binop (code, arg1, arg2, notrunc)
1271 enum tree_code code;
1278 if (TREE_CODE (arg1) == INTEGER_CST)
1279 return int_const_binop (code, arg1, arg2, notrunc);
1281 if (TREE_CODE (arg1) == REAL_CST)
1285 REAL_VALUE_TYPE value;
1288 d1 = TREE_REAL_CST (arg1);
1289 d2 = TREE_REAL_CST (arg2);
1291 /* If either operand is a NaN, just return it. Otherwise, set up
1292 for floating-point trap; we return an overflow. */
1293 if (REAL_VALUE_ISNAN (d1))
1295 else if (REAL_VALUE_ISNAN (d2))
1298 REAL_ARITHMETIC (value, code, d1, d2);
1300 t = build_real (TREE_TYPE (arg1),
1301 real_value_truncate (TYPE_MODE (TREE_TYPE (arg1)),
1305 = (force_fit_type (t, 0)
1306 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
1307 TREE_CONSTANT_OVERFLOW (t)
1309 | TREE_CONSTANT_OVERFLOW (arg1)
1310 | TREE_CONSTANT_OVERFLOW (arg2);
1313 if (TREE_CODE (arg1) == COMPLEX_CST)
1315 tree type = TREE_TYPE (arg1);
1316 tree r1 = TREE_REALPART (arg1);
1317 tree i1 = TREE_IMAGPART (arg1);
1318 tree r2 = TREE_REALPART (arg2);
1319 tree i2 = TREE_IMAGPART (arg2);
1325 t = build_complex (type,
1326 const_binop (PLUS_EXPR, r1, r2, notrunc),
1327 const_binop (PLUS_EXPR, i1, i2, notrunc));
1331 t = build_complex (type,
1332 const_binop (MINUS_EXPR, r1, r2, notrunc),
1333 const_binop (MINUS_EXPR, i1, i2, notrunc));
1337 t = build_complex (type,
1338 const_binop (MINUS_EXPR,
1339 const_binop (MULT_EXPR,
1341 const_binop (MULT_EXPR,
1344 const_binop (PLUS_EXPR,
1345 const_binop (MULT_EXPR,
1347 const_binop (MULT_EXPR,
1355 = const_binop (PLUS_EXPR,
1356 const_binop (MULT_EXPR, r2, r2, notrunc),
1357 const_binop (MULT_EXPR, i2, i2, notrunc),
1360 t = build_complex (type,
1362 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1363 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1364 const_binop (PLUS_EXPR,
1365 const_binop (MULT_EXPR, r1, r2,
1367 const_binop (MULT_EXPR, i1, i2,
1370 magsquared, notrunc),
1372 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1373 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1374 const_binop (MINUS_EXPR,
1375 const_binop (MULT_EXPR, i1, r2,
1377 const_binop (MULT_EXPR, r1, i2,
1380 magsquared, notrunc));
1392 /* These are the hash table functions for the hash table of INTEGER_CST
1393 nodes of a sizetype. */
1395 /* Return the hash code code X, an INTEGER_CST. */
1403 return (TREE_INT_CST_HIGH (t) ^ TREE_INT_CST_LOW (t)
1404 ^ htab_hash_pointer (TREE_TYPE (t))
1405 ^ (TREE_OVERFLOW (t) << 20));
1408 /* Return nonzero if the value represented by *X (an INTEGER_CST tree node)
1409 is the same as that given by *Y, which is the same. */
1419 return (TREE_INT_CST_HIGH (xt) == TREE_INT_CST_HIGH (yt)
1420 && TREE_INT_CST_LOW (xt) == TREE_INT_CST_LOW (yt)
1421 && TREE_TYPE (xt) == TREE_TYPE (yt)
1422 && TREE_OVERFLOW (xt) == TREE_OVERFLOW (yt));
1425 /* Return an INTEGER_CST with value whose low-order HOST_BITS_PER_WIDE_INT
1426 bits are given by NUMBER and of the sizetype represented by KIND. */
1429 size_int_wide (number, kind)
1430 HOST_WIDE_INT number;
1431 enum size_type_kind kind;
1433 return size_int_type_wide (number, sizetype_tab[(int) kind]);
1436 /* Likewise, but the desired type is specified explicitly. */
1438 static GTY (()) tree new_const;
1439 static GTY ((if_marked ("ggc_marked_p"), param_is (union tree_node)))
1443 size_int_type_wide (number, type)
1444 HOST_WIDE_INT number;
1451 size_htab = htab_create_ggc (1024, size_htab_hash, size_htab_eq, NULL);
1452 new_const = make_node (INTEGER_CST);
1455 /* Adjust NEW_CONST to be the constant we want. If it's already in the
1456 hash table, we return the value from the hash table. Otherwise, we
1457 place that in the hash table and make a new node for the next time. */
1458 TREE_INT_CST_LOW (new_const) = number;
1459 TREE_INT_CST_HIGH (new_const) = number < 0 ? -1 : 0;
1460 TREE_TYPE (new_const) = type;
1461 TREE_OVERFLOW (new_const) = TREE_CONSTANT_OVERFLOW (new_const)
1462 = force_fit_type (new_const, 0);
1464 slot = htab_find_slot (size_htab, new_const, INSERT);
1470 new_const = make_node (INTEGER_CST);
1474 return (tree) *slot;
1477 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1478 is a tree code. The type of the result is taken from the operands.
1479 Both must be the same type integer type and it must be a size type.
1480 If the operands are constant, so is the result. */
1483 size_binop (code, arg0, arg1)
1484 enum tree_code code;
1487 tree type = TREE_TYPE (arg0);
1489 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1490 || type != TREE_TYPE (arg1))
1493 /* Handle the special case of two integer constants faster. */
1494 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1496 /* And some specific cases even faster than that. */
1497 if (code == PLUS_EXPR && integer_zerop (arg0))
1499 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1500 && integer_zerop (arg1))
1502 else if (code == MULT_EXPR && integer_onep (arg0))
1505 /* Handle general case of two integer constants. */
1506 return int_const_binop (code, arg0, arg1, 0);
1509 if (arg0 == error_mark_node || arg1 == error_mark_node)
1510 return error_mark_node;
1512 return fold (build (code, type, arg0, arg1));
1515 /* Given two values, either both of sizetype or both of bitsizetype,
1516 compute the difference between the two values. Return the value
1517 in signed type corresponding to the type of the operands. */
1520 size_diffop (arg0, arg1)
1523 tree type = TREE_TYPE (arg0);
1526 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1527 || type != TREE_TYPE (arg1))
1530 /* If the type is already signed, just do the simple thing. */
1531 if (! TREE_UNSIGNED (type))
1532 return size_binop (MINUS_EXPR, arg0, arg1);
1534 ctype = (type == bitsizetype || type == ubitsizetype
1535 ? sbitsizetype : ssizetype);
1537 /* If either operand is not a constant, do the conversions to the signed
1538 type and subtract. The hardware will do the right thing with any
1539 overflow in the subtraction. */
1540 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
1541 return size_binop (MINUS_EXPR, convert (ctype, arg0),
1542 convert (ctype, arg1));
1544 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
1545 Otherwise, subtract the other way, convert to CTYPE (we know that can't
1546 overflow) and negate (which can't either). Special-case a result
1547 of zero while we're here. */
1548 if (tree_int_cst_equal (arg0, arg1))
1549 return convert (ctype, integer_zero_node);
1550 else if (tree_int_cst_lt (arg1, arg0))
1551 return convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
1553 return size_binop (MINUS_EXPR, convert (ctype, integer_zero_node),
1554 convert (ctype, size_binop (MINUS_EXPR, arg1, arg0)));
1558 /* Given T, a tree representing type conversion of ARG1, a constant,
1559 return a constant tree representing the result of conversion. */
1562 fold_convert (t, arg1)
1566 tree type = TREE_TYPE (t);
1569 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
1571 if (TREE_CODE (arg1) == INTEGER_CST)
1573 /* If we would build a constant wider than GCC supports,
1574 leave the conversion unfolded. */
1575 if (TYPE_PRECISION (type) > 2 * HOST_BITS_PER_WIDE_INT)
1578 /* If we are trying to make a sizetype for a small integer, use
1579 size_int to pick up cached types to reduce duplicate nodes. */
1580 if (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type)
1581 && !TREE_CONSTANT_OVERFLOW (arg1)
1582 && compare_tree_int (arg1, 10000) < 0)
1583 return size_int_type_wide (TREE_INT_CST_LOW (arg1), type);
1585 /* Given an integer constant, make new constant with new type,
1586 appropriately sign-extended or truncated. */
1587 t = build_int_2 (TREE_INT_CST_LOW (arg1),
1588 TREE_INT_CST_HIGH (arg1));
1589 TREE_TYPE (t) = type;
1590 /* Indicate an overflow if (1) ARG1 already overflowed,
1591 or (2) force_fit_type indicates an overflow.
1592 Tell force_fit_type that an overflow has already occurred
1593 if ARG1 is a too-large unsigned value and T is signed.
1594 But don't indicate an overflow if converting a pointer. */
1596 = ((force_fit_type (t,
1597 (TREE_INT_CST_HIGH (arg1) < 0
1598 && (TREE_UNSIGNED (type)
1599 < TREE_UNSIGNED (TREE_TYPE (arg1)))))
1600 && ! POINTER_TYPE_P (TREE_TYPE (arg1)))
1601 || TREE_OVERFLOW (arg1));
1602 TREE_CONSTANT_OVERFLOW (t)
1603 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1605 else if (TREE_CODE (arg1) == REAL_CST)
1607 /* Don't initialize these, use assignments.
1608 Initialized local aggregates don't work on old compilers. */
1612 tree type1 = TREE_TYPE (arg1);
1615 x = TREE_REAL_CST (arg1);
1616 l = real_value_from_int_cst (type1, TYPE_MIN_VALUE (type));
1618 no_upper_bound = (TYPE_MAX_VALUE (type) == NULL);
1619 if (!no_upper_bound)
1620 u = real_value_from_int_cst (type1, TYPE_MAX_VALUE (type));
1622 /* See if X will be in range after truncation towards 0.
1623 To compensate for truncation, move the bounds away from 0,
1624 but reject if X exactly equals the adjusted bounds. */
1625 REAL_ARITHMETIC (l, MINUS_EXPR, l, dconst1);
1626 if (!no_upper_bound)
1627 REAL_ARITHMETIC (u, PLUS_EXPR, u, dconst1);
1628 /* If X is a NaN, use zero instead and show we have an overflow.
1629 Otherwise, range check. */
1630 if (REAL_VALUE_ISNAN (x))
1631 overflow = 1, x = dconst0;
1632 else if (! (REAL_VALUES_LESS (l, x)
1634 && REAL_VALUES_LESS (x, u)))
1638 HOST_WIDE_INT low, high;
1639 REAL_VALUE_TO_INT (&low, &high, x);
1640 t = build_int_2 (low, high);
1642 TREE_TYPE (t) = type;
1644 = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
1645 TREE_CONSTANT_OVERFLOW (t)
1646 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1648 TREE_TYPE (t) = type;
1650 else if (TREE_CODE (type) == REAL_TYPE)
1652 if (TREE_CODE (arg1) == INTEGER_CST)
1653 return build_real_from_int_cst (type, arg1);
1654 if (TREE_CODE (arg1) == REAL_CST)
1656 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
1658 /* We make a copy of ARG1 so that we don't modify an
1659 existing constant tree. */
1660 t = copy_node (arg1);
1661 TREE_TYPE (t) = type;
1665 t = build_real (type,
1666 real_value_truncate (TYPE_MODE (type),
1667 TREE_REAL_CST (arg1)));
1670 = TREE_OVERFLOW (arg1) | force_fit_type (t, 0);
1671 TREE_CONSTANT_OVERFLOW (t)
1672 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1676 TREE_CONSTANT (t) = 1;
1680 /* Return an expr equal to X but certainly not valid as an lvalue. */
1688 /* These things are certainly not lvalues. */
1689 if (TREE_CODE (x) == NON_LVALUE_EXPR
1690 || TREE_CODE (x) == INTEGER_CST
1691 || TREE_CODE (x) == REAL_CST
1692 || TREE_CODE (x) == STRING_CST
1693 || TREE_CODE (x) == ADDR_EXPR)
1696 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
1697 TREE_CONSTANT (result) = TREE_CONSTANT (x);
1701 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
1702 Zero means allow extended lvalues. */
1704 int pedantic_lvalues;
1706 /* When pedantic, return an expr equal to X but certainly not valid as a
1707 pedantic lvalue. Otherwise, return X. */
1710 pedantic_non_lvalue (x)
1713 if (pedantic_lvalues)
1714 return non_lvalue (x);
1719 /* Given a tree comparison code, return the code that is the logical inverse
1720 of the given code. It is not safe to do this for floating-point
1721 comparisons, except for NE_EXPR and EQ_EXPR. */
1723 static enum tree_code
1724 invert_tree_comparison (code)
1725 enum tree_code code;
1746 /* Similar, but return the comparison that results if the operands are
1747 swapped. This is safe for floating-point. */
1749 static enum tree_code
1750 swap_tree_comparison (code)
1751 enum tree_code code;
1772 /* Convert a comparison tree code from an enum tree_code representation
1773 into a compcode bit-based encoding. This function is the inverse of
1774 compcode_to_comparison. */
1777 comparison_to_compcode (code)
1778 enum tree_code code;
1799 /* Convert a compcode bit-based encoding of a comparison operator back
1800 to GCC's enum tree_code representation. This function is the
1801 inverse of comparison_to_compcode. */
1803 static enum tree_code
1804 compcode_to_comparison (code)
1826 /* Return nonzero if CODE is a tree code that represents a truth value. */
1829 truth_value_p (code)
1830 enum tree_code code;
1832 return (TREE_CODE_CLASS (code) == '<'
1833 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
1834 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
1835 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
1838 /* Return nonzero if two operands are necessarily equal.
1839 If ONLY_CONST is nonzero, only return nonzero for constants.
1840 This function tests whether the operands are indistinguishable;
1841 it does not test whether they are equal using C's == operation.
1842 The distinction is important for IEEE floating point, because
1843 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
1844 (2) two NaNs may be indistinguishable, but NaN!=NaN. */
1847 operand_equal_p (arg0, arg1, only_const)
1851 /* If both types don't have the same signedness, then we can't consider
1852 them equal. We must check this before the STRIP_NOPS calls
1853 because they may change the signedness of the arguments. */
1854 if (TREE_UNSIGNED (TREE_TYPE (arg0)) != TREE_UNSIGNED (TREE_TYPE (arg1)))
1860 if (TREE_CODE (arg0) != TREE_CODE (arg1)
1861 /* This is needed for conversions and for COMPONENT_REF.
1862 Might as well play it safe and always test this. */
1863 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
1864 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
1865 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
1868 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
1869 We don't care about side effects in that case because the SAVE_EXPR
1870 takes care of that for us. In all other cases, two expressions are
1871 equal if they have no side effects. If we have two identical
1872 expressions with side effects that should be treated the same due
1873 to the only side effects being identical SAVE_EXPR's, that will
1874 be detected in the recursive calls below. */
1875 if (arg0 == arg1 && ! only_const
1876 && (TREE_CODE (arg0) == SAVE_EXPR
1877 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
1880 /* Next handle constant cases, those for which we can return 1 even
1881 if ONLY_CONST is set. */
1882 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
1883 switch (TREE_CODE (arg0))
1886 return (! TREE_CONSTANT_OVERFLOW (arg0)
1887 && ! TREE_CONSTANT_OVERFLOW (arg1)
1888 && tree_int_cst_equal (arg0, arg1));
1891 return (! TREE_CONSTANT_OVERFLOW (arg0)
1892 && ! TREE_CONSTANT_OVERFLOW (arg1)
1893 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
1894 TREE_REAL_CST (arg1)));
1900 if (TREE_CONSTANT_OVERFLOW (arg0)
1901 || TREE_CONSTANT_OVERFLOW (arg1))
1904 v1 = TREE_VECTOR_CST_ELTS (arg0);
1905 v2 = TREE_VECTOR_CST_ELTS (arg1);
1908 if (!operand_equal_p (v1, v2, only_const))
1910 v1 = TREE_CHAIN (v1);
1911 v2 = TREE_CHAIN (v2);
1918 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
1920 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
1924 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
1925 && ! memcmp (TREE_STRING_POINTER (arg0),
1926 TREE_STRING_POINTER (arg1),
1927 TREE_STRING_LENGTH (arg0)));
1930 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
1939 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
1942 /* Two conversions are equal only if signedness and modes match. */
1943 if ((TREE_CODE (arg0) == NOP_EXPR || TREE_CODE (arg0) == CONVERT_EXPR)
1944 && (TREE_UNSIGNED (TREE_TYPE (arg0))
1945 != TREE_UNSIGNED (TREE_TYPE (arg1))))
1948 return operand_equal_p (TREE_OPERAND (arg0, 0),
1949 TREE_OPERAND (arg1, 0), 0);
1953 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0)
1954 && operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1),
1958 /* For commutative ops, allow the other order. */
1959 return ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MULT_EXPR
1960 || TREE_CODE (arg0) == MIN_EXPR || TREE_CODE (arg0) == MAX_EXPR
1961 || TREE_CODE (arg0) == BIT_IOR_EXPR
1962 || TREE_CODE (arg0) == BIT_XOR_EXPR
1963 || TREE_CODE (arg0) == BIT_AND_EXPR
1964 || TREE_CODE (arg0) == NE_EXPR || TREE_CODE (arg0) == EQ_EXPR)
1965 && operand_equal_p (TREE_OPERAND (arg0, 0),
1966 TREE_OPERAND (arg1, 1), 0)
1967 && operand_equal_p (TREE_OPERAND (arg0, 1),
1968 TREE_OPERAND (arg1, 0), 0));
1971 /* If either of the pointer (or reference) expressions we are
1972 dereferencing contain a side effect, these cannot be equal. */
1973 if (TREE_SIDE_EFFECTS (arg0)
1974 || TREE_SIDE_EFFECTS (arg1))
1977 switch (TREE_CODE (arg0))
1980 return operand_equal_p (TREE_OPERAND (arg0, 0),
1981 TREE_OPERAND (arg1, 0), 0);
1985 case ARRAY_RANGE_REF:
1986 return (operand_equal_p (TREE_OPERAND (arg0, 0),
1987 TREE_OPERAND (arg1, 0), 0)
1988 && operand_equal_p (TREE_OPERAND (arg0, 1),
1989 TREE_OPERAND (arg1, 1), 0));
1992 return (operand_equal_p (TREE_OPERAND (arg0, 0),
1993 TREE_OPERAND (arg1, 0), 0)
1994 && operand_equal_p (TREE_OPERAND (arg0, 1),
1995 TREE_OPERAND (arg1, 1), 0)
1996 && operand_equal_p (TREE_OPERAND (arg0, 2),
1997 TREE_OPERAND (arg1, 2), 0));
2003 switch (TREE_CODE (arg0))
2006 case TRUTH_NOT_EXPR:
2007 return operand_equal_p (TREE_OPERAND (arg0, 0),
2008 TREE_OPERAND (arg1, 0), 0);
2011 return rtx_equal_p (RTL_EXPR_RTL (arg0), RTL_EXPR_RTL (arg1));
2014 /* If the CALL_EXPRs call different functions, then they
2015 clearly can not be equal. */
2016 if (! operand_equal_p (TREE_OPERAND (arg0, 0),
2017 TREE_OPERAND (arg1, 0), 0))
2020 /* Only consider const functions equivalent. */
2021 if (TREE_CODE (TREE_OPERAND (arg0, 0)) == ADDR_EXPR)
2023 tree fndecl = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
2024 if (! (flags_from_decl_or_type (fndecl) & ECF_CONST))
2030 /* Now see if all the arguments are the same. operand_equal_p
2031 does not handle TREE_LIST, so we walk the operands here
2032 feeding them to operand_equal_p. */
2033 arg0 = TREE_OPERAND (arg0, 1);
2034 arg1 = TREE_OPERAND (arg1, 1);
2035 while (arg0 && arg1)
2037 if (! operand_equal_p (TREE_VALUE (arg0), TREE_VALUE (arg1), 0))
2040 arg0 = TREE_CHAIN (arg0);
2041 arg1 = TREE_CHAIN (arg1);
2044 /* If we get here and both argument lists are exhausted
2045 then the CALL_EXPRs are equal. */
2046 return ! (arg0 || arg1);
2053 /* Consider __builtin_sqrt equal to sqrt. */
2054 return TREE_CODE (arg0) == FUNCTION_DECL
2055 && DECL_BUILT_IN (arg0) && DECL_BUILT_IN (arg1)
2056 && DECL_BUILT_IN_CLASS (arg0) == DECL_BUILT_IN_CLASS (arg1)
2057 && DECL_FUNCTION_CODE (arg0) == DECL_FUNCTION_CODE (arg1);
2064 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2065 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2067 When in doubt, return 0. */
2070 operand_equal_for_comparison_p (arg0, arg1, other)
2074 int unsignedp1, unsignedpo;
2075 tree primarg0, primarg1, primother;
2076 unsigned int correct_width;
2078 if (operand_equal_p (arg0, arg1, 0))
2081 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
2082 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
2085 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2086 and see if the inner values are the same. This removes any
2087 signedness comparison, which doesn't matter here. */
2088 primarg0 = arg0, primarg1 = arg1;
2089 STRIP_NOPS (primarg0);
2090 STRIP_NOPS (primarg1);
2091 if (operand_equal_p (primarg0, primarg1, 0))
2094 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2095 actual comparison operand, ARG0.
2097 First throw away any conversions to wider types
2098 already present in the operands. */
2100 primarg1 = get_narrower (arg1, &unsignedp1);
2101 primother = get_narrower (other, &unsignedpo);
2103 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
2104 if (unsignedp1 == unsignedpo
2105 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
2106 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
2108 tree type = TREE_TYPE (arg0);
2110 /* Make sure shorter operand is extended the right way
2111 to match the longer operand. */
2112 primarg1 = convert ((*lang_hooks.types.signed_or_unsigned_type)
2113 (unsignedp1, TREE_TYPE (primarg1)), primarg1);
2115 if (operand_equal_p (arg0, convert (type, primarg1), 0))
2122 /* See if ARG is an expression that is either a comparison or is performing
2123 arithmetic on comparisons. The comparisons must only be comparing
2124 two different values, which will be stored in *CVAL1 and *CVAL2; if
2125 they are nonzero it means that some operands have already been found.
2126 No variables may be used anywhere else in the expression except in the
2127 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2128 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2130 If this is true, return 1. Otherwise, return zero. */
2133 twoval_comparison_p (arg, cval1, cval2, save_p)
2135 tree *cval1, *cval2;
2138 enum tree_code code = TREE_CODE (arg);
2139 char class = TREE_CODE_CLASS (code);
2141 /* We can handle some of the 'e' cases here. */
2142 if (class == 'e' && code == TRUTH_NOT_EXPR)
2144 else if (class == 'e'
2145 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
2146 || code == COMPOUND_EXPR))
2149 else if (class == 'e' && code == SAVE_EXPR && SAVE_EXPR_RTL (arg) == 0
2150 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
2152 /* If we've already found a CVAL1 or CVAL2, this expression is
2153 two complex to handle. */
2154 if (*cval1 || *cval2)
2164 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
2167 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
2168 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2169 cval1, cval2, save_p));
2175 if (code == COND_EXPR)
2176 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
2177 cval1, cval2, save_p)
2178 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2179 cval1, cval2, save_p)
2180 && twoval_comparison_p (TREE_OPERAND (arg, 2),
2181 cval1, cval2, save_p));
2185 /* First see if we can handle the first operand, then the second. For
2186 the second operand, we know *CVAL1 can't be zero. It must be that
2187 one side of the comparison is each of the values; test for the
2188 case where this isn't true by failing if the two operands
2191 if (operand_equal_p (TREE_OPERAND (arg, 0),
2192 TREE_OPERAND (arg, 1), 0))
2196 *cval1 = TREE_OPERAND (arg, 0);
2197 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
2199 else if (*cval2 == 0)
2200 *cval2 = TREE_OPERAND (arg, 0);
2201 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
2206 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
2208 else if (*cval2 == 0)
2209 *cval2 = TREE_OPERAND (arg, 1);
2210 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
2222 /* ARG is a tree that is known to contain just arithmetic operations and
2223 comparisons. Evaluate the operations in the tree substituting NEW0 for
2224 any occurrence of OLD0 as an operand of a comparison and likewise for
2228 eval_subst (arg, old0, new0, old1, new1)
2230 tree old0, new0, old1, new1;
2232 tree type = TREE_TYPE (arg);
2233 enum tree_code code = TREE_CODE (arg);
2234 char class = TREE_CODE_CLASS (code);
2236 /* We can handle some of the 'e' cases here. */
2237 if (class == 'e' && code == TRUTH_NOT_EXPR)
2239 else if (class == 'e'
2240 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2246 return fold (build1 (code, type,
2247 eval_subst (TREE_OPERAND (arg, 0),
2248 old0, new0, old1, new1)));
2251 return fold (build (code, type,
2252 eval_subst (TREE_OPERAND (arg, 0),
2253 old0, new0, old1, new1),
2254 eval_subst (TREE_OPERAND (arg, 1),
2255 old0, new0, old1, new1)));
2261 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
2264 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
2267 return fold (build (code, type,
2268 eval_subst (TREE_OPERAND (arg, 0),
2269 old0, new0, old1, new1),
2270 eval_subst (TREE_OPERAND (arg, 1),
2271 old0, new0, old1, new1),
2272 eval_subst (TREE_OPERAND (arg, 2),
2273 old0, new0, old1, new1)));
2277 /* fall through - ??? */
2281 tree arg0 = TREE_OPERAND (arg, 0);
2282 tree arg1 = TREE_OPERAND (arg, 1);
2284 /* We need to check both for exact equality and tree equality. The
2285 former will be true if the operand has a side-effect. In that
2286 case, we know the operand occurred exactly once. */
2288 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
2290 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
2293 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
2295 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
2298 return fold (build (code, type, arg0, arg1));
2306 /* Return a tree for the case when the result of an expression is RESULT
2307 converted to TYPE and OMITTED was previously an operand of the expression
2308 but is now not needed (e.g., we folded OMITTED * 0).
2310 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2311 the conversion of RESULT to TYPE. */
2314 omit_one_operand (type, result, omitted)
2315 tree type, result, omitted;
2317 tree t = convert (type, result);
2319 if (TREE_SIDE_EFFECTS (omitted))
2320 return build (COMPOUND_EXPR, type, omitted, t);
2322 return non_lvalue (t);
2325 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2328 pedantic_omit_one_operand (type, result, omitted)
2329 tree type, result, omitted;
2331 tree t = convert (type, result);
2333 if (TREE_SIDE_EFFECTS (omitted))
2334 return build (COMPOUND_EXPR, type, omitted, t);
2336 return pedantic_non_lvalue (t);
2339 /* Return a simplified tree node for the truth-negation of ARG. This
2340 never alters ARG itself. We assume that ARG is an operation that
2341 returns a truth value (0 or 1). */
2344 invert_truthvalue (arg)
2347 tree type = TREE_TYPE (arg);
2348 enum tree_code code = TREE_CODE (arg);
2350 if (code == ERROR_MARK)
2353 /* If this is a comparison, we can simply invert it, except for
2354 floating-point non-equality comparisons, in which case we just
2355 enclose a TRUTH_NOT_EXPR around what we have. */
2357 if (TREE_CODE_CLASS (code) == '<')
2359 if (FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg, 0)))
2360 && !flag_unsafe_math_optimizations
2363 return build1 (TRUTH_NOT_EXPR, type, arg);
2365 return build (invert_tree_comparison (code), type,
2366 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
2372 return convert (type, build_int_2 (integer_zerop (arg), 0));
2374 case TRUTH_AND_EXPR:
2375 return build (TRUTH_OR_EXPR, type,
2376 invert_truthvalue (TREE_OPERAND (arg, 0)),
2377 invert_truthvalue (TREE_OPERAND (arg, 1)));
2380 return build (TRUTH_AND_EXPR, type,
2381 invert_truthvalue (TREE_OPERAND (arg, 0)),
2382 invert_truthvalue (TREE_OPERAND (arg, 1)));
2384 case TRUTH_XOR_EXPR:
2385 /* Here we can invert either operand. We invert the first operand
2386 unless the second operand is a TRUTH_NOT_EXPR in which case our
2387 result is the XOR of the first operand with the inside of the
2388 negation of the second operand. */
2390 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
2391 return build (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
2392 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
2394 return build (TRUTH_XOR_EXPR, type,
2395 invert_truthvalue (TREE_OPERAND (arg, 0)),
2396 TREE_OPERAND (arg, 1));
2398 case TRUTH_ANDIF_EXPR:
2399 return build (TRUTH_ORIF_EXPR, type,
2400 invert_truthvalue (TREE_OPERAND (arg, 0)),
2401 invert_truthvalue (TREE_OPERAND (arg, 1)));
2403 case TRUTH_ORIF_EXPR:
2404 return build (TRUTH_ANDIF_EXPR, type,
2405 invert_truthvalue (TREE_OPERAND (arg, 0)),
2406 invert_truthvalue (TREE_OPERAND (arg, 1)));
2408 case TRUTH_NOT_EXPR:
2409 return TREE_OPERAND (arg, 0);
2412 return build (COND_EXPR, type, TREE_OPERAND (arg, 0),
2413 invert_truthvalue (TREE_OPERAND (arg, 1)),
2414 invert_truthvalue (TREE_OPERAND (arg, 2)));
2417 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
2418 invert_truthvalue (TREE_OPERAND (arg, 1)));
2420 case WITH_RECORD_EXPR:
2421 return build (WITH_RECORD_EXPR, type,
2422 invert_truthvalue (TREE_OPERAND (arg, 0)),
2423 TREE_OPERAND (arg, 1));
2425 case NON_LVALUE_EXPR:
2426 return invert_truthvalue (TREE_OPERAND (arg, 0));
2431 return build1 (TREE_CODE (arg), type,
2432 invert_truthvalue (TREE_OPERAND (arg, 0)));
2435 if (!integer_onep (TREE_OPERAND (arg, 1)))
2437 return build (EQ_EXPR, type, arg, convert (type, integer_zero_node));
2440 return build1 (TRUTH_NOT_EXPR, type, arg);
2442 case CLEANUP_POINT_EXPR:
2443 return build1 (CLEANUP_POINT_EXPR, type,
2444 invert_truthvalue (TREE_OPERAND (arg, 0)));
2449 if (TREE_CODE (TREE_TYPE (arg)) != BOOLEAN_TYPE)
2451 return build1 (TRUTH_NOT_EXPR, type, arg);
2454 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
2455 operands are another bit-wise operation with a common input. If so,
2456 distribute the bit operations to save an operation and possibly two if
2457 constants are involved. For example, convert
2458 (A | B) & (A | C) into A | (B & C)
2459 Further simplification will occur if B and C are constants.
2461 If this optimization cannot be done, 0 will be returned. */
2464 distribute_bit_expr (code, type, arg0, arg1)
2465 enum tree_code code;
2472 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2473 || TREE_CODE (arg0) == code
2474 || (TREE_CODE (arg0) != BIT_AND_EXPR
2475 && TREE_CODE (arg0) != BIT_IOR_EXPR))
2478 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
2480 common = TREE_OPERAND (arg0, 0);
2481 left = TREE_OPERAND (arg0, 1);
2482 right = TREE_OPERAND (arg1, 1);
2484 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
2486 common = TREE_OPERAND (arg0, 0);
2487 left = TREE_OPERAND (arg0, 1);
2488 right = TREE_OPERAND (arg1, 0);
2490 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
2492 common = TREE_OPERAND (arg0, 1);
2493 left = TREE_OPERAND (arg0, 0);
2494 right = TREE_OPERAND (arg1, 1);
2496 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
2498 common = TREE_OPERAND (arg0, 1);
2499 left = TREE_OPERAND (arg0, 0);
2500 right = TREE_OPERAND (arg1, 0);
2505 return fold (build (TREE_CODE (arg0), type, common,
2506 fold (build (code, type, left, right))));
2509 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
2510 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
2513 make_bit_field_ref (inner, type, bitsize, bitpos, unsignedp)
2516 int bitsize, bitpos;
2519 tree result = build (BIT_FIELD_REF, type, inner,
2520 size_int (bitsize), bitsize_int (bitpos));
2522 TREE_UNSIGNED (result) = unsignedp;
2527 /* Optimize a bit-field compare.
2529 There are two cases: First is a compare against a constant and the
2530 second is a comparison of two items where the fields are at the same
2531 bit position relative to the start of a chunk (byte, halfword, word)
2532 large enough to contain it. In these cases we can avoid the shift
2533 implicit in bitfield extractions.
2535 For constants, we emit a compare of the shifted constant with the
2536 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
2537 compared. For two fields at the same position, we do the ANDs with the
2538 similar mask and compare the result of the ANDs.
2540 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
2541 COMPARE_TYPE is the type of the comparison, and LHS and RHS
2542 are the left and right operands of the comparison, respectively.
2544 If the optimization described above can be done, we return the resulting
2545 tree. Otherwise we return zero. */
2548 optimize_bit_field_compare (code, compare_type, lhs, rhs)
2549 enum tree_code code;
2553 HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
2554 tree type = TREE_TYPE (lhs);
2555 tree signed_type, unsigned_type;
2556 int const_p = TREE_CODE (rhs) == INTEGER_CST;
2557 enum machine_mode lmode, rmode, nmode;
2558 int lunsignedp, runsignedp;
2559 int lvolatilep = 0, rvolatilep = 0;
2560 tree linner, rinner = NULL_TREE;
2564 /* Get all the information about the extractions being done. If the bit size
2565 if the same as the size of the underlying object, we aren't doing an
2566 extraction at all and so can do nothing. We also don't want to
2567 do anything if the inner expression is a PLACEHOLDER_EXPR since we
2568 then will no longer be able to replace it. */
2569 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
2570 &lunsignedp, &lvolatilep);
2571 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
2572 || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
2577 /* If this is not a constant, we can only do something if bit positions,
2578 sizes, and signedness are the same. */
2579 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
2580 &runsignedp, &rvolatilep);
2582 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
2583 || lunsignedp != runsignedp || offset != 0
2584 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
2588 /* See if we can find a mode to refer to this field. We should be able to,
2589 but fail if we can't. */
2590 nmode = get_best_mode (lbitsize, lbitpos,
2591 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
2592 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
2593 TYPE_ALIGN (TREE_TYPE (rinner))),
2594 word_mode, lvolatilep || rvolatilep);
2595 if (nmode == VOIDmode)
2598 /* Set signed and unsigned types of the precision of this mode for the
2600 signed_type = (*lang_hooks.types.type_for_mode) (nmode, 0);
2601 unsigned_type = (*lang_hooks.types.type_for_mode) (nmode, 1);
2603 /* Compute the bit position and size for the new reference and our offset
2604 within it. If the new reference is the same size as the original, we
2605 won't optimize anything, so return zero. */
2606 nbitsize = GET_MODE_BITSIZE (nmode);
2607 nbitpos = lbitpos & ~ (nbitsize - 1);
2609 if (nbitsize == lbitsize)
2612 if (BYTES_BIG_ENDIAN)
2613 lbitpos = nbitsize - lbitsize - lbitpos;
2615 /* Make the mask to be used against the extracted field. */
2616 mask = build_int_2 (~0, ~0);
2617 TREE_TYPE (mask) = unsigned_type;
2618 force_fit_type (mask, 0);
2619 mask = convert (unsigned_type, mask);
2620 mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
2621 mask = const_binop (RSHIFT_EXPR, mask,
2622 size_int (nbitsize - lbitsize - lbitpos), 0);
2625 /* If not comparing with constant, just rework the comparison
2627 return build (code, compare_type,
2628 build (BIT_AND_EXPR, unsigned_type,
2629 make_bit_field_ref (linner, unsigned_type,
2630 nbitsize, nbitpos, 1),
2632 build (BIT_AND_EXPR, unsigned_type,
2633 make_bit_field_ref (rinner, unsigned_type,
2634 nbitsize, nbitpos, 1),
2637 /* Otherwise, we are handling the constant case. See if the constant is too
2638 big for the field. Warn and return a tree of for 0 (false) if so. We do
2639 this not only for its own sake, but to avoid having to test for this
2640 error case below. If we didn't, we might generate wrong code.
2642 For unsigned fields, the constant shifted right by the field length should
2643 be all zero. For signed fields, the high-order bits should agree with
2648 if (! integer_zerop (const_binop (RSHIFT_EXPR,
2649 convert (unsigned_type, rhs),
2650 size_int (lbitsize), 0)))
2652 warning ("comparison is always %d due to width of bit-field",
2654 return convert (compare_type,
2656 ? integer_one_node : integer_zero_node));
2661 tree tem = const_binop (RSHIFT_EXPR, convert (signed_type, rhs),
2662 size_int (lbitsize - 1), 0);
2663 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
2665 warning ("comparison is always %d due to width of bit-field",
2667 return convert (compare_type,
2669 ? integer_one_node : integer_zero_node));
2673 /* Single-bit compares should always be against zero. */
2674 if (lbitsize == 1 && ! integer_zerop (rhs))
2676 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
2677 rhs = convert (type, integer_zero_node);
2680 /* Make a new bitfield reference, shift the constant over the
2681 appropriate number of bits and mask it with the computed mask
2682 (in case this was a signed field). If we changed it, make a new one. */
2683 lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1);
2686 TREE_SIDE_EFFECTS (lhs) = 1;
2687 TREE_THIS_VOLATILE (lhs) = 1;
2690 rhs = fold (const_binop (BIT_AND_EXPR,
2691 const_binop (LSHIFT_EXPR,
2692 convert (unsigned_type, rhs),
2693 size_int (lbitpos), 0),
2696 return build (code, compare_type,
2697 build (BIT_AND_EXPR, unsigned_type, lhs, mask),
2701 /* Subroutine for fold_truthop: decode a field reference.
2703 If EXP is a comparison reference, we return the innermost reference.
2705 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
2706 set to the starting bit number.
2708 If the innermost field can be completely contained in a mode-sized
2709 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
2711 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
2712 otherwise it is not changed.
2714 *PUNSIGNEDP is set to the signedness of the field.
2716 *PMASK is set to the mask used. This is either contained in a
2717 BIT_AND_EXPR or derived from the width of the field.
2719 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
2721 Return 0 if this is not a component reference or is one that we can't
2722 do anything with. */
2725 decode_field_reference (exp, pbitsize, pbitpos, pmode, punsignedp,
2726 pvolatilep, pmask, pand_mask)
2728 HOST_WIDE_INT *pbitsize, *pbitpos;
2729 enum machine_mode *pmode;
2730 int *punsignedp, *pvolatilep;
2735 tree mask, inner, offset;
2737 unsigned int precision;
2739 /* All the optimizations using this function assume integer fields.
2740 There are problems with FP fields since the type_for_size call
2741 below can fail for, e.g., XFmode. */
2742 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
2745 /* Signedness matters here. */
2746 STRIP_SIGN_NOPS (exp);
2748 if (TREE_CODE (exp) == BIT_AND_EXPR)
2750 and_mask = TREE_OPERAND (exp, 1);
2751 exp = TREE_OPERAND (exp, 0);
2752 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
2753 if (TREE_CODE (and_mask) != INTEGER_CST)
2757 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
2758 punsignedp, pvolatilep);
2759 if ((inner == exp && and_mask == 0)
2760 || *pbitsize < 0 || offset != 0
2761 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
2764 /* Compute the mask to access the bitfield. */
2765 unsigned_type = (*lang_hooks.types.type_for_size) (*pbitsize, 1);
2766 precision = TYPE_PRECISION (unsigned_type);
2768 mask = build_int_2 (~0, ~0);
2769 TREE_TYPE (mask) = unsigned_type;
2770 force_fit_type (mask, 0);
2771 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
2772 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
2774 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
2776 mask = fold (build (BIT_AND_EXPR, unsigned_type,
2777 convert (unsigned_type, and_mask), mask));
2780 *pand_mask = and_mask;
2784 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
2788 all_ones_mask_p (mask, size)
2792 tree type = TREE_TYPE (mask);
2793 unsigned int precision = TYPE_PRECISION (type);
2796 tmask = build_int_2 (~0, ~0);
2797 TREE_TYPE (tmask) = (*lang_hooks.types.signed_type) (type);
2798 force_fit_type (tmask, 0);
2800 tree_int_cst_equal (mask,
2801 const_binop (RSHIFT_EXPR,
2802 const_binop (LSHIFT_EXPR, tmask,
2803 size_int (precision - size),
2805 size_int (precision - size), 0));
2808 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
2809 represents the sign bit of EXP's type. If EXP represents a sign
2810 or zero extension, also test VAL against the unextended type.
2811 The return value is the (sub)expression whose sign bit is VAL,
2812 or NULL_TREE otherwise. */
2815 sign_bit_p (exp, val)
2819 unsigned HOST_WIDE_INT lo;
2824 /* Tree EXP must have an integral type. */
2825 t = TREE_TYPE (exp);
2826 if (! INTEGRAL_TYPE_P (t))
2829 /* Tree VAL must be an integer constant. */
2830 if (TREE_CODE (val) != INTEGER_CST
2831 || TREE_CONSTANT_OVERFLOW (val))
2834 width = TYPE_PRECISION (t);
2835 if (width > HOST_BITS_PER_WIDE_INT)
2837 hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1);
2843 lo = (unsigned HOST_WIDE_INT) 1 << (width - 1);
2846 if (TREE_INT_CST_HIGH (val) == hi && TREE_INT_CST_LOW (val) == lo)
2849 /* Handle extension from a narrower type. */
2850 if (TREE_CODE (exp) == NOP_EXPR
2851 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width)
2852 return sign_bit_p (TREE_OPERAND (exp, 0), val);
2857 /* Subroutine for fold_truthop: determine if an operand is simple enough
2858 to be evaluated unconditionally. */
2861 simple_operand_p (exp)
2864 /* Strip any conversions that don't change the machine mode. */
2865 while ((TREE_CODE (exp) == NOP_EXPR
2866 || TREE_CODE (exp) == CONVERT_EXPR)
2867 && (TYPE_MODE (TREE_TYPE (exp))
2868 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)))))
2869 exp = TREE_OPERAND (exp, 0);
2871 return (TREE_CODE_CLASS (TREE_CODE (exp)) == 'c'
2873 && ! TREE_ADDRESSABLE (exp)
2874 && ! TREE_THIS_VOLATILE (exp)
2875 && ! DECL_NONLOCAL (exp)
2876 /* Don't regard global variables as simple. They may be
2877 allocated in ways unknown to the compiler (shared memory,
2878 #pragma weak, etc). */
2879 && ! TREE_PUBLIC (exp)
2880 && ! DECL_EXTERNAL (exp)
2881 /* Loading a static variable is unduly expensive, but global
2882 registers aren't expensive. */
2883 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
2886 /* The following functions are subroutines to fold_range_test and allow it to
2887 try to change a logical combination of comparisons into a range test.
2890 X == 2 || X == 3 || X == 4 || X == 5
2894 (unsigned) (X - 2) <= 3
2896 We describe each set of comparisons as being either inside or outside
2897 a range, using a variable named like IN_P, and then describe the
2898 range with a lower and upper bound. If one of the bounds is omitted,
2899 it represents either the highest or lowest value of the type.
2901 In the comments below, we represent a range by two numbers in brackets
2902 preceded by a "+" to designate being inside that range, or a "-" to
2903 designate being outside that range, so the condition can be inverted by
2904 flipping the prefix. An omitted bound is represented by a "-". For
2905 example, "- [-, 10]" means being outside the range starting at the lowest
2906 possible value and ending at 10, in other words, being greater than 10.
2907 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
2910 We set up things so that the missing bounds are handled in a consistent
2911 manner so neither a missing bound nor "true" and "false" need to be
2912 handled using a special case. */
2914 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
2915 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
2916 and UPPER1_P are nonzero if the respective argument is an upper bound
2917 and zero for a lower. TYPE, if nonzero, is the type of the result; it
2918 must be specified for a comparison. ARG1 will be converted to ARG0's
2919 type if both are specified. */
2922 range_binop (code, type, arg0, upper0_p, arg1, upper1_p)
2923 enum tree_code code;
2926 int upper0_p, upper1_p;
2932 /* If neither arg represents infinity, do the normal operation.
2933 Else, if not a comparison, return infinity. Else handle the special
2934 comparison rules. Note that most of the cases below won't occur, but
2935 are handled for consistency. */
2937 if (arg0 != 0 && arg1 != 0)
2939 tem = fold (build (code, type != 0 ? type : TREE_TYPE (arg0),
2940 arg0, convert (TREE_TYPE (arg0), arg1)));
2942 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
2945 if (TREE_CODE_CLASS (code) != '<')
2948 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
2949 for neither. In real maths, we cannot assume open ended ranges are
2950 the same. But, this is computer arithmetic, where numbers are finite.
2951 We can therefore make the transformation of any unbounded range with
2952 the value Z, Z being greater than any representable number. This permits
2953 us to treat unbounded ranges as equal. */
2954 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
2955 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
2959 result = sgn0 == sgn1;
2962 result = sgn0 != sgn1;
2965 result = sgn0 < sgn1;
2968 result = sgn0 <= sgn1;
2971 result = sgn0 > sgn1;
2974 result = sgn0 >= sgn1;
2980 return convert (type, result ? integer_one_node : integer_zero_node);
2983 /* Given EXP, a logical expression, set the range it is testing into
2984 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
2985 actually being tested. *PLOW and *PHIGH will be made of the same type
2986 as the returned expression. If EXP is not a comparison, we will most
2987 likely not be returning a useful value and range. */
2990 make_range (exp, pin_p, plow, phigh)
2995 enum tree_code code;
2996 tree arg0 = NULL_TREE, arg1 = NULL_TREE, type = NULL_TREE;
2997 tree orig_type = NULL_TREE;
2999 tree low, high, n_low, n_high;
3001 /* Start with simply saying "EXP != 0" and then look at the code of EXP
3002 and see if we can refine the range. Some of the cases below may not
3003 happen, but it doesn't seem worth worrying about this. We "continue"
3004 the outer loop when we've changed something; otherwise we "break"
3005 the switch, which will "break" the while. */
3007 in_p = 0, low = high = convert (TREE_TYPE (exp), integer_zero_node);
3011 code = TREE_CODE (exp);
3013 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
3015 arg0 = TREE_OPERAND (exp, 0);
3016 if (TREE_CODE_CLASS (code) == '<'
3017 || TREE_CODE_CLASS (code) == '1'
3018 || TREE_CODE_CLASS (code) == '2')
3019 type = TREE_TYPE (arg0);
3020 if (TREE_CODE_CLASS (code) == '2'
3021 || TREE_CODE_CLASS (code) == '<'
3022 || (TREE_CODE_CLASS (code) == 'e'
3023 && TREE_CODE_LENGTH (code) > 1))
3024 arg1 = TREE_OPERAND (exp, 1);
3027 /* Set ORIG_TYPE as soon as TYPE is non-null so that we do not
3028 lose a cast by accident. */
3029 if (type != NULL_TREE && orig_type == NULL_TREE)
3034 case TRUTH_NOT_EXPR:
3035 in_p = ! in_p, exp = arg0;
3038 case EQ_EXPR: case NE_EXPR:
3039 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
3040 /* We can only do something if the range is testing for zero
3041 and if the second operand is an integer constant. Note that
3042 saying something is "in" the range we make is done by
3043 complementing IN_P since it will set in the initial case of
3044 being not equal to zero; "out" is leaving it alone. */
3045 if (low == 0 || high == 0
3046 || ! integer_zerop (low) || ! integer_zerop (high)
3047 || TREE_CODE (arg1) != INTEGER_CST)
3052 case NE_EXPR: /* - [c, c] */
3055 case EQ_EXPR: /* + [c, c] */
3056 in_p = ! in_p, low = high = arg1;
3058 case GT_EXPR: /* - [-, c] */
3059 low = 0, high = arg1;
3061 case GE_EXPR: /* + [c, -] */
3062 in_p = ! in_p, low = arg1, high = 0;
3064 case LT_EXPR: /* - [c, -] */
3065 low = arg1, high = 0;
3067 case LE_EXPR: /* + [-, c] */
3068 in_p = ! in_p, low = 0, high = arg1;
3076 /* If this is an unsigned comparison, we also know that EXP is
3077 greater than or equal to zero. We base the range tests we make
3078 on that fact, so we record it here so we can parse existing
3080 if (TREE_UNSIGNED (type) && (low == 0 || high == 0))
3082 if (! merge_ranges (&n_in_p, &n_low, &n_high, in_p, low, high,
3083 1, convert (type, integer_zero_node),
3087 in_p = n_in_p, low = n_low, high = n_high;
3089 /* If the high bound is missing, but we
3090 have a low bound, reverse the range so
3091 it goes from zero to the low bound minus 1. */
3092 if (high == 0 && low)
3095 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
3096 integer_one_node, 0);
3097 low = convert (type, integer_zero_node);
3103 /* (-x) IN [a,b] -> x in [-b, -a] */
3104 n_low = range_binop (MINUS_EXPR, type,
3105 convert (type, integer_zero_node), 0, high, 1);
3106 n_high = range_binop (MINUS_EXPR, type,
3107 convert (type, integer_zero_node), 0, low, 0);
3108 low = n_low, high = n_high;
3114 exp = build (MINUS_EXPR, type, negate_expr (arg0),
3115 convert (type, integer_one_node));
3118 case PLUS_EXPR: case MINUS_EXPR:
3119 if (TREE_CODE (arg1) != INTEGER_CST)
3122 /* If EXP is signed, any overflow in the computation is undefined,
3123 so we don't worry about it so long as our computations on
3124 the bounds don't overflow. For unsigned, overflow is defined
3125 and this is exactly the right thing. */
3126 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3127 type, low, 0, arg1, 0);
3128 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3129 type, high, 1, arg1, 0);
3130 if ((n_low != 0 && TREE_OVERFLOW (n_low))
3131 || (n_high != 0 && TREE_OVERFLOW (n_high)))
3134 /* Check for an unsigned range which has wrapped around the maximum
3135 value thus making n_high < n_low, and normalize it. */
3136 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
3138 low = range_binop (PLUS_EXPR, type, n_high, 0,
3139 integer_one_node, 0);
3140 high = range_binop (MINUS_EXPR, type, n_low, 0,
3141 integer_one_node, 0);
3143 /* If the range is of the form +/- [ x+1, x ], we won't
3144 be able to normalize it. But then, it represents the
3145 whole range or the empty set, so make it
3147 if (tree_int_cst_equal (n_low, low)
3148 && tree_int_cst_equal (n_high, high))
3154 low = n_low, high = n_high;
3159 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
3160 if (TYPE_PRECISION (type) > TYPE_PRECISION (orig_type))
3163 if (! INTEGRAL_TYPE_P (type)
3164 || (low != 0 && ! int_fits_type_p (low, type))
3165 || (high != 0 && ! int_fits_type_p (high, type)))
3168 n_low = low, n_high = high;
3171 n_low = convert (type, n_low);
3174 n_high = convert (type, n_high);
3176 /* If we're converting from an unsigned to a signed type,
3177 we will be doing the comparison as unsigned. The tests above
3178 have already verified that LOW and HIGH are both positive.
3180 So we have to make sure that the original unsigned value will
3181 be interpreted as positive. */
3182 if (TREE_UNSIGNED (type) && ! TREE_UNSIGNED (TREE_TYPE (exp)))
3184 tree equiv_type = (*lang_hooks.types.type_for_mode)
3185 (TYPE_MODE (type), 1);
3188 /* A range without an upper bound is, naturally, unbounded.
3189 Since convert would have cropped a very large value, use
3190 the max value for the destination type. */
3192 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
3193 : TYPE_MAX_VALUE (type);
3195 if (TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (exp)))
3196 high_positive = fold (build (RSHIFT_EXPR, type,
3197 convert (type, high_positive),
3198 convert (type, integer_one_node)));
3200 /* If the low bound is specified, "and" the range with the
3201 range for which the original unsigned value will be
3205 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3207 1, convert (type, integer_zero_node),
3211 in_p = (n_in_p == in_p);
3215 /* Otherwise, "or" the range with the range of the input
3216 that will be interpreted as negative. */
3217 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3219 1, convert (type, integer_zero_node),
3223 in_p = (in_p != n_in_p);
3228 low = n_low, high = n_high;
3238 /* If EXP is a constant, we can evaluate whether this is true or false. */
3239 if (TREE_CODE (exp) == INTEGER_CST)
3241 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
3243 && integer_onep (range_binop (LE_EXPR, integer_type_node,
3249 *pin_p = in_p, *plow = low, *phigh = high;
3253 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3254 type, TYPE, return an expression to test if EXP is in (or out of, depending
3255 on IN_P) the range. */
3258 build_range_check (type, exp, in_p, low, high)
3264 tree etype = TREE_TYPE (exp);
3268 && (0 != (value = build_range_check (type, exp, 1, low, high))))
3269 return invert_truthvalue (value);
3271 if (low == 0 && high == 0)
3272 return convert (type, integer_one_node);
3275 return fold (build (LE_EXPR, type, exp, high));
3278 return fold (build (GE_EXPR, type, exp, low));
3280 if (operand_equal_p (low, high, 0))
3281 return fold (build (EQ_EXPR, type, exp, low));
3283 if (integer_zerop (low))
3285 if (! TREE_UNSIGNED (etype))
3287 etype = (*lang_hooks.types.unsigned_type) (etype);
3288 high = convert (etype, high);
3289 exp = convert (etype, exp);
3291 return build_range_check (type, exp, 1, 0, high);
3294 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
3295 if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST)
3297 unsigned HOST_WIDE_INT lo;
3301 prec = TYPE_PRECISION (etype);
3302 if (prec <= HOST_BITS_PER_WIDE_INT)
3305 lo = ((unsigned HOST_WIDE_INT) 1 << (prec - 1)) - 1;
3309 hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1;
3310 lo = (unsigned HOST_WIDE_INT) -1;
3313 if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo)
3315 if (TREE_UNSIGNED (etype))
3317 etype = (*lang_hooks.types.signed_type) (etype);
3318 exp = convert (etype, exp);
3320 return fold (build (GT_EXPR, type, exp,
3321 convert (etype, integer_zero_node)));
3325 if (0 != (value = const_binop (MINUS_EXPR, high, low, 0))
3326 && ! TREE_OVERFLOW (value))
3327 return build_range_check (type,
3328 fold (build (MINUS_EXPR, etype, exp, low)),
3329 1, convert (etype, integer_zero_node), value);
3334 /* Given two ranges, see if we can merge them into one. Return 1 if we
3335 can, 0 if we can't. Set the output range into the specified parameters. */
3338 merge_ranges (pin_p, plow, phigh, in0_p, low0, high0, in1_p, low1, high1)
3342 tree low0, high0, low1, high1;
3350 int lowequal = ((low0 == 0 && low1 == 0)
3351 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3352 low0, 0, low1, 0)));
3353 int highequal = ((high0 == 0 && high1 == 0)
3354 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3355 high0, 1, high1, 1)));
3357 /* Make range 0 be the range that starts first, or ends last if they
3358 start at the same value. Swap them if it isn't. */
3359 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
3362 && integer_onep (range_binop (GT_EXPR, integer_type_node,
3363 high1, 1, high0, 1))))
3365 temp = in0_p, in0_p = in1_p, in1_p = temp;
3366 tem = low0, low0 = low1, low1 = tem;
3367 tem = high0, high0 = high1, high1 = tem;
3370 /* Now flag two cases, whether the ranges are disjoint or whether the
3371 second range is totally subsumed in the first. Note that the tests
3372 below are simplified by the ones above. */
3373 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
3374 high0, 1, low1, 0));
3375 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
3376 high1, 1, high0, 1));
3378 /* We now have four cases, depending on whether we are including or
3379 excluding the two ranges. */
3382 /* If they don't overlap, the result is false. If the second range
3383 is a subset it is the result. Otherwise, the range is from the start
3384 of the second to the end of the first. */
3386 in_p = 0, low = high = 0;
3388 in_p = 1, low = low1, high = high1;
3390 in_p = 1, low = low1, high = high0;
3393 else if (in0_p && ! in1_p)
3395 /* If they don't overlap, the result is the first range. If they are
3396 equal, the result is false. If the second range is a subset of the
3397 first, and the ranges begin at the same place, we go from just after
3398 the end of the first range to the end of the second. If the second
3399 range is not a subset of the first, or if it is a subset and both
3400 ranges end at the same place, the range starts at the start of the
3401 first range and ends just before the second range.
3402 Otherwise, we can't describe this as a single range. */
3404 in_p = 1, low = low0, high = high0;
3405 else if (lowequal && highequal)
3406 in_p = 0, low = high = 0;
3407 else if (subset && lowequal)
3409 in_p = 1, high = high0;
3410 low = range_binop (PLUS_EXPR, NULL_TREE, high1, 0,
3411 integer_one_node, 0);
3413 else if (! subset || highequal)
3415 in_p = 1, low = low0;
3416 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
3417 integer_one_node, 0);
3423 else if (! in0_p && in1_p)
3425 /* If they don't overlap, the result is the second range. If the second
3426 is a subset of the first, the result is false. Otherwise,
3427 the range starts just after the first range and ends at the
3428 end of the second. */
3430 in_p = 1, low = low1, high = high1;
3431 else if (subset || highequal)
3432 in_p = 0, low = high = 0;
3435 in_p = 1, high = high1;
3436 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
3437 integer_one_node, 0);
3443 /* The case where we are excluding both ranges. Here the complex case
3444 is if they don't overlap. In that case, the only time we have a
3445 range is if they are adjacent. If the second is a subset of the
3446 first, the result is the first. Otherwise, the range to exclude
3447 starts at the beginning of the first range and ends at the end of the
3451 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
3452 range_binop (PLUS_EXPR, NULL_TREE,
3454 integer_one_node, 1),
3456 in_p = 0, low = low0, high = high1;
3461 in_p = 0, low = low0, high = high0;
3463 in_p = 0, low = low0, high = high1;
3466 *pin_p = in_p, *plow = low, *phigh = high;
3470 #ifndef RANGE_TEST_NON_SHORT_CIRCUIT
3471 #define RANGE_TEST_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
3474 /* EXP is some logical combination of boolean tests. See if we can
3475 merge it into some range test. Return the new tree if so. */
3478 fold_range_test (exp)
3481 int or_op = (TREE_CODE (exp) == TRUTH_ORIF_EXPR
3482 || TREE_CODE (exp) == TRUTH_OR_EXPR);
3483 int in0_p, in1_p, in_p;
3484 tree low0, low1, low, high0, high1, high;
3485 tree lhs = make_range (TREE_OPERAND (exp, 0), &in0_p, &low0, &high0);
3486 tree rhs = make_range (TREE_OPERAND (exp, 1), &in1_p, &low1, &high1);
3489 /* If this is an OR operation, invert both sides; we will invert
3490 again at the end. */
3492 in0_p = ! in0_p, in1_p = ! in1_p;
3494 /* If both expressions are the same, if we can merge the ranges, and we
3495 can build the range test, return it or it inverted. If one of the
3496 ranges is always true or always false, consider it to be the same
3497 expression as the other. */
3498 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
3499 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
3501 && 0 != (tem = (build_range_check (TREE_TYPE (exp),
3503 : rhs != 0 ? rhs : integer_zero_node,
3505 return or_op ? invert_truthvalue (tem) : tem;
3507 /* On machines where the branch cost is expensive, if this is a
3508 short-circuited branch and the underlying object on both sides
3509 is the same, make a non-short-circuit operation. */
3510 else if (RANGE_TEST_NON_SHORT_CIRCUIT
3511 && lhs != 0 && rhs != 0
3512 && (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3513 || TREE_CODE (exp) == TRUTH_ORIF_EXPR)
3514 && operand_equal_p (lhs, rhs, 0))
3516 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
3517 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
3518 which cases we can't do this. */
3519 if (simple_operand_p (lhs))
3520 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3521 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3522 TREE_TYPE (exp), TREE_OPERAND (exp, 0),
3523 TREE_OPERAND (exp, 1));
3525 else if ((*lang_hooks.decls.global_bindings_p) () == 0
3526 && ! CONTAINS_PLACEHOLDER_P (lhs))
3528 tree common = save_expr (lhs);
3530 if (0 != (lhs = build_range_check (TREE_TYPE (exp), common,
3531 or_op ? ! in0_p : in0_p,
3533 && (0 != (rhs = build_range_check (TREE_TYPE (exp), common,
3534 or_op ? ! in1_p : in1_p,
3536 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3537 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3538 TREE_TYPE (exp), lhs, rhs);
3545 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
3546 bit value. Arrange things so the extra bits will be set to zero if and
3547 only if C is signed-extended to its full width. If MASK is nonzero,
3548 it is an INTEGER_CST that should be AND'ed with the extra bits. */
3551 unextend (c, p, unsignedp, mask)
3557 tree type = TREE_TYPE (c);
3558 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
3561 if (p == modesize || unsignedp)
3564 /* We work by getting just the sign bit into the low-order bit, then
3565 into the high-order bit, then sign-extend. We then XOR that value
3567 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
3568 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
3570 /* We must use a signed type in order to get an arithmetic right shift.
3571 However, we must also avoid introducing accidental overflows, so that
3572 a subsequent call to integer_zerop will work. Hence we must
3573 do the type conversion here. At this point, the constant is either
3574 zero or one, and the conversion to a signed type can never overflow.
3575 We could get an overflow if this conversion is done anywhere else. */
3576 if (TREE_UNSIGNED (type))
3577 temp = convert ((*lang_hooks.types.signed_type) (type), temp);
3579 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
3580 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
3582 temp = const_binop (BIT_AND_EXPR, temp, convert (TREE_TYPE (c), mask), 0);
3583 /* If necessary, convert the type back to match the type of C. */
3584 if (TREE_UNSIGNED (type))
3585 temp = convert (type, temp);
3587 return convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
3590 /* Find ways of folding logical expressions of LHS and RHS:
3591 Try to merge two comparisons to the same innermost item.
3592 Look for range tests like "ch >= '0' && ch <= '9'".
3593 Look for combinations of simple terms on machines with expensive branches
3594 and evaluate the RHS unconditionally.
3596 For example, if we have p->a == 2 && p->b == 4 and we can make an
3597 object large enough to span both A and B, we can do this with a comparison
3598 against the object ANDed with the a mask.
3600 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
3601 operations to do this with one comparison.
3603 We check for both normal comparisons and the BIT_AND_EXPRs made this by
3604 function and the one above.
3606 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
3607 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
3609 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
3612 We return the simplified tree or 0 if no optimization is possible. */
3615 fold_truthop (code, truth_type, lhs, rhs)
3616 enum tree_code code;
3617 tree truth_type, lhs, rhs;
3619 /* If this is the "or" of two comparisons, we can do something if
3620 the comparisons are NE_EXPR. If this is the "and", we can do something
3621 if the comparisons are EQ_EXPR. I.e.,
3622 (a->b == 2 && a->c == 4) can become (a->new == NEW).
3624 WANTED_CODE is this operation code. For single bit fields, we can
3625 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
3626 comparison for one-bit fields. */
3628 enum tree_code wanted_code;
3629 enum tree_code lcode, rcode;
3630 tree ll_arg, lr_arg, rl_arg, rr_arg;
3631 tree ll_inner, lr_inner, rl_inner, rr_inner;
3632 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
3633 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
3634 HOST_WIDE_INT xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
3635 HOST_WIDE_INT lnbitsize, lnbitpos, rnbitsize, rnbitpos;
3636 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
3637 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
3638 enum machine_mode lnmode, rnmode;
3639 tree ll_mask, lr_mask, rl_mask, rr_mask;
3640 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
3641 tree l_const, r_const;
3642 tree lntype, rntype, result;
3643 int first_bit, end_bit;
3646 /* Start by getting the comparison codes. Fail if anything is volatile.
3647 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
3648 it were surrounded with a NE_EXPR. */
3650 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
3653 lcode = TREE_CODE (lhs);
3654 rcode = TREE_CODE (rhs);
3656 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
3657 lcode = NE_EXPR, lhs = build (NE_EXPR, truth_type, lhs, integer_zero_node);
3659 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
3660 rcode = NE_EXPR, rhs = build (NE_EXPR, truth_type, rhs, integer_zero_node);
3662 if (TREE_CODE_CLASS (lcode) != '<' || TREE_CODE_CLASS (rcode) != '<')
3665 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
3666 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
3668 ll_arg = TREE_OPERAND (lhs, 0);
3669 lr_arg = TREE_OPERAND (lhs, 1);
3670 rl_arg = TREE_OPERAND (rhs, 0);
3671 rr_arg = TREE_OPERAND (rhs, 1);
3673 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
3674 if (simple_operand_p (ll_arg)
3675 && simple_operand_p (lr_arg)
3676 && !FLOAT_TYPE_P (TREE_TYPE (ll_arg)))
3680 if (operand_equal_p (ll_arg, rl_arg, 0)
3681 && operand_equal_p (lr_arg, rr_arg, 0))
3683 int lcompcode, rcompcode;
3685 lcompcode = comparison_to_compcode (lcode);
3686 rcompcode = comparison_to_compcode (rcode);
3687 compcode = (code == TRUTH_AND_EXPR)
3688 ? lcompcode & rcompcode
3689 : lcompcode | rcompcode;
3691 else if (operand_equal_p (ll_arg, rr_arg, 0)
3692 && operand_equal_p (lr_arg, rl_arg, 0))
3694 int lcompcode, rcompcode;
3696 rcode = swap_tree_comparison (rcode);
3697 lcompcode = comparison_to_compcode (lcode);
3698 rcompcode = comparison_to_compcode (rcode);
3699 compcode = (code == TRUTH_AND_EXPR)
3700 ? lcompcode & rcompcode
3701 : lcompcode | rcompcode;
3706 if (compcode == COMPCODE_TRUE)
3707 return convert (truth_type, integer_one_node);
3708 else if (compcode == COMPCODE_FALSE)
3709 return convert (truth_type, integer_zero_node);
3710 else if (compcode != -1)
3711 return build (compcode_to_comparison (compcode),
3712 truth_type, ll_arg, lr_arg);
3715 /* If the RHS can be evaluated unconditionally and its operands are
3716 simple, it wins to evaluate the RHS unconditionally on machines
3717 with expensive branches. In this case, this isn't a comparison
3718 that can be merged. Avoid doing this if the RHS is a floating-point
3719 comparison since those can trap. */
3721 if (BRANCH_COST >= 2
3722 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
3723 && simple_operand_p (rl_arg)
3724 && simple_operand_p (rr_arg))
3726 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
3727 if (code == TRUTH_OR_EXPR
3728 && lcode == NE_EXPR && integer_zerop (lr_arg)
3729 && rcode == NE_EXPR && integer_zerop (rr_arg)
3730 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
3731 return build (NE_EXPR, truth_type,
3732 build (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
3736 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
3737 if (code == TRUTH_AND_EXPR
3738 && lcode == EQ_EXPR && integer_zerop (lr_arg)
3739 && rcode == EQ_EXPR && integer_zerop (rr_arg)
3740 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
3741 return build (EQ_EXPR, truth_type,
3742 build (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
3746 return build (code, truth_type, lhs, rhs);
3749 /* See if the comparisons can be merged. Then get all the parameters for
3752 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
3753 || (rcode != EQ_EXPR && rcode != NE_EXPR))
3757 ll_inner = decode_field_reference (ll_arg,
3758 &ll_bitsize, &ll_bitpos, &ll_mode,
3759 &ll_unsignedp, &volatilep, &ll_mask,
3761 lr_inner = decode_field_reference (lr_arg,
3762 &lr_bitsize, &lr_bitpos, &lr_mode,
3763 &lr_unsignedp, &volatilep, &lr_mask,
3765 rl_inner = decode_field_reference (rl_arg,
3766 &rl_bitsize, &rl_bitpos, &rl_mode,
3767 &rl_unsignedp, &volatilep, &rl_mask,
3769 rr_inner = decode_field_reference (rr_arg,
3770 &rr_bitsize, &rr_bitpos, &rr_mode,
3771 &rr_unsignedp, &volatilep, &rr_mask,
3774 /* It must be true that the inner operation on the lhs of each
3775 comparison must be the same if we are to be able to do anything.
3776 Then see if we have constants. If not, the same must be true for
3778 if (volatilep || ll_inner == 0 || rl_inner == 0
3779 || ! operand_equal_p (ll_inner, rl_inner, 0))
3782 if (TREE_CODE (lr_arg) == INTEGER_CST
3783 && TREE_CODE (rr_arg) == INTEGER_CST)
3784 l_const = lr_arg, r_const = rr_arg;
3785 else if (lr_inner == 0 || rr_inner == 0
3786 || ! operand_equal_p (lr_inner, rr_inner, 0))
3789 l_const = r_const = 0;
3791 /* If either comparison code is not correct for our logical operation,
3792 fail. However, we can convert a one-bit comparison against zero into
3793 the opposite comparison against that bit being set in the field. */
3795 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
3796 if (lcode != wanted_code)
3798 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
3800 /* Make the left operand unsigned, since we are only interested
3801 in the value of one bit. Otherwise we are doing the wrong
3810 /* This is analogous to the code for l_const above. */
3811 if (rcode != wanted_code)
3813 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
3822 /* After this point all optimizations will generate bit-field
3823 references, which we might not want. */
3824 if (! (*lang_hooks.can_use_bit_fields_p) ())
3827 /* See if we can find a mode that contains both fields being compared on
3828 the left. If we can't, fail. Otherwise, update all constants and masks
3829 to be relative to a field of that size. */
3830 first_bit = MIN (ll_bitpos, rl_bitpos);
3831 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
3832 lnmode = get_best_mode (end_bit - first_bit, first_bit,
3833 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
3835 if (lnmode == VOIDmode)
3838 lnbitsize = GET_MODE_BITSIZE (lnmode);
3839 lnbitpos = first_bit & ~ (lnbitsize - 1);
3840 lntype = (*lang_hooks.types.type_for_size) (lnbitsize, 1);
3841 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
3843 if (BYTES_BIG_ENDIAN)
3845 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
3846 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
3849 ll_mask = const_binop (LSHIFT_EXPR, convert (lntype, ll_mask),
3850 size_int (xll_bitpos), 0);
3851 rl_mask = const_binop (LSHIFT_EXPR, convert (lntype, rl_mask),
3852 size_int (xrl_bitpos), 0);
3856 l_const = convert (lntype, l_const);
3857 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
3858 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
3859 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
3860 fold (build1 (BIT_NOT_EXPR,
3864 warning ("comparison is always %d", wanted_code == NE_EXPR);
3866 return convert (truth_type,
3867 wanted_code == NE_EXPR
3868 ? integer_one_node : integer_zero_node);
3873 r_const = convert (lntype, r_const);
3874 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
3875 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
3876 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
3877 fold (build1 (BIT_NOT_EXPR,
3881 warning ("comparison is always %d", wanted_code == NE_EXPR);
3883 return convert (truth_type,
3884 wanted_code == NE_EXPR
3885 ? integer_one_node : integer_zero_node);
3889 /* If the right sides are not constant, do the same for it. Also,
3890 disallow this optimization if a size or signedness mismatch occurs
3891 between the left and right sides. */
3894 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
3895 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
3896 /* Make sure the two fields on the right
3897 correspond to the left without being swapped. */
3898 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
3901 first_bit = MIN (lr_bitpos, rr_bitpos);
3902 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
3903 rnmode = get_best_mode (end_bit - first_bit, first_bit,
3904 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
3906 if (rnmode == VOIDmode)
3909 rnbitsize = GET_MODE_BITSIZE (rnmode);
3910 rnbitpos = first_bit & ~ (rnbitsize - 1);
3911 rntype = (*lang_hooks.types.type_for_size) (rnbitsize, 1);
3912 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
3914 if (BYTES_BIG_ENDIAN)
3916 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
3917 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
3920 lr_mask = const_binop (LSHIFT_EXPR, convert (rntype, lr_mask),
3921 size_int (xlr_bitpos), 0);
3922 rr_mask = const_binop (LSHIFT_EXPR, convert (rntype, rr_mask),
3923 size_int (xrr_bitpos), 0);
3925 /* Make a mask that corresponds to both fields being compared.
3926 Do this for both items being compared. If the operands are the
3927 same size and the bits being compared are in the same position
3928 then we can do this by masking both and comparing the masked
3930 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
3931 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
3932 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
3934 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
3935 ll_unsignedp || rl_unsignedp);
3936 if (! all_ones_mask_p (ll_mask, lnbitsize))
3937 lhs = build (BIT_AND_EXPR, lntype, lhs, ll_mask);
3939 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
3940 lr_unsignedp || rr_unsignedp);
3941 if (! all_ones_mask_p (lr_mask, rnbitsize))
3942 rhs = build (BIT_AND_EXPR, rntype, rhs, lr_mask);
3944 return build (wanted_code, truth_type, lhs, rhs);
3947 /* There is still another way we can do something: If both pairs of
3948 fields being compared are adjacent, we may be able to make a wider
3949 field containing them both.
3951 Note that we still must mask the lhs/rhs expressions. Furthermore,
3952 the mask must be shifted to account for the shift done by
3953 make_bit_field_ref. */
3954 if ((ll_bitsize + ll_bitpos == rl_bitpos
3955 && lr_bitsize + lr_bitpos == rr_bitpos)
3956 || (ll_bitpos == rl_bitpos + rl_bitsize
3957 && lr_bitpos == rr_bitpos + rr_bitsize))
3961 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
3962 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
3963 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
3964 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
3966 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
3967 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
3968 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
3969 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
3971 /* Convert to the smaller type before masking out unwanted bits. */
3973 if (lntype != rntype)
3975 if (lnbitsize > rnbitsize)
3977 lhs = convert (rntype, lhs);
3978 ll_mask = convert (rntype, ll_mask);
3981 else if (lnbitsize < rnbitsize)
3983 rhs = convert (lntype, rhs);
3984 lr_mask = convert (lntype, lr_mask);
3989 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
3990 lhs = build (BIT_AND_EXPR, type, lhs, ll_mask);
3992 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
3993 rhs = build (BIT_AND_EXPR, type, rhs, lr_mask);
3995 return build (wanted_code, truth_type, lhs, rhs);
4001 /* Handle the case of comparisons with constants. If there is something in
4002 common between the masks, those bits of the constants must be the same.
4003 If not, the condition is always false. Test for this to avoid generating
4004 incorrect code below. */
4005 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
4006 if (! integer_zerop (result)
4007 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
4008 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
4010 if (wanted_code == NE_EXPR)
4012 warning ("`or' of unmatched not-equal tests is always 1");
4013 return convert (truth_type, integer_one_node);
4017 warning ("`and' of mutually exclusive equal-tests is always 0");
4018 return convert (truth_type, integer_zero_node);
4022 /* Construct the expression we will return. First get the component
4023 reference we will make. Unless the mask is all ones the width of
4024 that field, perform the mask operation. Then compare with the
4026 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4027 ll_unsignedp || rl_unsignedp);
4029 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4030 if (! all_ones_mask_p (ll_mask, lnbitsize))
4031 result = build (BIT_AND_EXPR, lntype, result, ll_mask);
4033 return build (wanted_code, truth_type, result,
4034 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
4037 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
4041 optimize_minmax_comparison (t)
4044 tree type = TREE_TYPE (t);
4045 tree arg0 = TREE_OPERAND (t, 0);
4046 enum tree_code op_code;
4047 tree comp_const = TREE_OPERAND (t, 1);
4049 int consts_equal, consts_lt;
4052 STRIP_SIGN_NOPS (arg0);
4054 op_code = TREE_CODE (arg0);
4055 minmax_const = TREE_OPERAND (arg0, 1);
4056 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
4057 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
4058 inner = TREE_OPERAND (arg0, 0);
4060 /* If something does not permit us to optimize, return the original tree. */
4061 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
4062 || TREE_CODE (comp_const) != INTEGER_CST
4063 || TREE_CONSTANT_OVERFLOW (comp_const)
4064 || TREE_CODE (minmax_const) != INTEGER_CST
4065 || TREE_CONSTANT_OVERFLOW (minmax_const))
4068 /* Now handle all the various comparison codes. We only handle EQ_EXPR
4069 and GT_EXPR, doing the rest with recursive calls using logical
4071 switch (TREE_CODE (t))
4073 case NE_EXPR: case LT_EXPR: case LE_EXPR:
4075 invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t)));
4079 fold (build (TRUTH_ORIF_EXPR, type,
4080 optimize_minmax_comparison
4081 (build (EQ_EXPR, type, arg0, comp_const)),
4082 optimize_minmax_comparison
4083 (build (GT_EXPR, type, arg0, comp_const))));
4086 if (op_code == MAX_EXPR && consts_equal)
4087 /* MAX (X, 0) == 0 -> X <= 0 */
4088 return fold (build (LE_EXPR, type, inner, comp_const));
4090 else if (op_code == MAX_EXPR && consts_lt)
4091 /* MAX (X, 0) == 5 -> X == 5 */
4092 return fold (build (EQ_EXPR, type, inner, comp_const));
4094 else if (op_code == MAX_EXPR)
4095 /* MAX (X, 0) == -1 -> false */
4096 return omit_one_operand (type, integer_zero_node, inner);
4098 else if (consts_equal)
4099 /* MIN (X, 0) == 0 -> X >= 0 */
4100 return fold (build (GE_EXPR, type, inner, comp_const));
4103 /* MIN (X, 0) == 5 -> false */
4104 return omit_one_operand (type, integer_zero_node, inner);
4107 /* MIN (X, 0) == -1 -> X == -1 */
4108 return fold (build (EQ_EXPR, type, inner, comp_const));
4111 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
4112 /* MAX (X, 0) > 0 -> X > 0
4113 MAX (X, 0) > 5 -> X > 5 */
4114 return fold (build (GT_EXPR, type, inner, comp_const));
4116 else if (op_code == MAX_EXPR)
4117 /* MAX (X, 0) > -1 -> true */
4118 return omit_one_operand (type, integer_one_node, inner);
4120 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
4121 /* MIN (X, 0) > 0 -> false
4122 MIN (X, 0) > 5 -> false */
4123 return omit_one_operand (type, integer_zero_node, inner);
4126 /* MIN (X, 0) > -1 -> X > -1 */
4127 return fold (build (GT_EXPR, type, inner, comp_const));
4134 /* T is an integer expression that is being multiplied, divided, or taken a
4135 modulus (CODE says which and what kind of divide or modulus) by a
4136 constant C. See if we can eliminate that operation by folding it with
4137 other operations already in T. WIDE_TYPE, if non-null, is a type that
4138 should be used for the computation if wider than our type.
4140 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
4141 (X * 2) + (Y * 4). We must, however, be assured that either the original
4142 expression would not overflow or that overflow is undefined for the type
4143 in the language in question.
4145 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
4146 the machine has a multiply-accumulate insn or that this is part of an
4147 addressing calculation.
4149 If we return a non-null expression, it is an equivalent form of the
4150 original computation, but need not be in the original type. */
4153 extract_muldiv (t, c, code, wide_type)
4156 enum tree_code code;
4159 /* To avoid exponential search depth, refuse to allow recursion past
4160 three levels. Beyond that (1) it's highly unlikely that we'll find
4161 something interesting and (2) we've probably processed it before
4162 when we built the inner expression. */
4171 ret = extract_muldiv_1 (t, c, code, wide_type);
4178 extract_muldiv_1 (t, c, code, wide_type)
4181 enum tree_code code;
4184 tree type = TREE_TYPE (t);
4185 enum tree_code tcode = TREE_CODE (t);
4186 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
4187 > GET_MODE_SIZE (TYPE_MODE (type)))
4188 ? wide_type : type);
4190 int same_p = tcode == code;
4191 tree op0 = NULL_TREE, op1 = NULL_TREE;
4193 /* Don't deal with constants of zero here; they confuse the code below. */
4194 if (integer_zerop (c))
4197 if (TREE_CODE_CLASS (tcode) == '1')
4198 op0 = TREE_OPERAND (t, 0);
4200 if (TREE_CODE_CLASS (tcode) == '2')
4201 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
4203 /* Note that we need not handle conditional operations here since fold
4204 already handles those cases. So just do arithmetic here. */
4208 /* For a constant, we can always simplify if we are a multiply
4209 or (for divide and modulus) if it is a multiple of our constant. */
4210 if (code == MULT_EXPR
4211 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
4212 return const_binop (code, convert (ctype, t), convert (ctype, c), 0);
4215 case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
4216 /* If op0 is an expression ... */
4217 if ((TREE_CODE_CLASS (TREE_CODE (op0)) == '<'
4218 || TREE_CODE_CLASS (TREE_CODE (op0)) == '1'
4219 || TREE_CODE_CLASS (TREE_CODE (op0)) == '2'
4220 || TREE_CODE_CLASS (TREE_CODE (op0)) == 'e')
4221 /* ... and is unsigned, and its type is smaller than ctype,
4222 then we cannot pass through as widening. */
4223 && ((TREE_UNSIGNED (TREE_TYPE (op0))
4224 && ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
4225 && TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
4226 && (GET_MODE_SIZE (TYPE_MODE (ctype))
4227 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
4228 /* ... or its type is larger than ctype,
4229 then we cannot pass through this truncation. */
4230 || (GET_MODE_SIZE (TYPE_MODE (ctype))
4231 < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0))))
4232 /* ... or signedness changes for division or modulus,
4233 then we cannot pass through this conversion. */
4234 || (code != MULT_EXPR
4235 && (TREE_UNSIGNED (ctype)
4236 != TREE_UNSIGNED (TREE_TYPE (op0))))))
4239 /* Pass the constant down and see if we can make a simplification. If
4240 we can, replace this expression with the inner simplification for
4241 possible later conversion to our or some other type. */
4242 if ((t2 = convert (TREE_TYPE (op0), c)) != 0
4243 && TREE_CODE (t2) == INTEGER_CST
4244 && ! TREE_CONSTANT_OVERFLOW (t2)
4245 && (0 != (t1 = extract_muldiv (op0, t2, code,
4247 ? ctype : NULL_TREE))))
4251 case NEGATE_EXPR: case ABS_EXPR:
4252 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4253 return fold (build1 (tcode, ctype, convert (ctype, t1)));
4256 case MIN_EXPR: case MAX_EXPR:
4257 /* If widening the type changes the signedness, then we can't perform
4258 this optimization as that changes the result. */
4259 if (TREE_UNSIGNED (ctype) != TREE_UNSIGNED (type))
4262 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
4263 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0
4264 && (t2 = extract_muldiv (op1, c, code, wide_type)) != 0)
4266 if (tree_int_cst_sgn (c) < 0)
4267 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
4269 return fold (build (tcode, ctype, convert (ctype, t1),
4270 convert (ctype, t2)));
4274 case WITH_RECORD_EXPR:
4275 if ((t1 = extract_muldiv (TREE_OPERAND (t, 0), c, code, wide_type)) != 0)
4276 return build (WITH_RECORD_EXPR, TREE_TYPE (t1), t1,
4277 TREE_OPERAND (t, 1));
4281 /* If this has not been evaluated and the operand has no side effects,
4282 we can see if we can do something inside it and make a new one.
4283 Note that this test is overly conservative since we can do this
4284 if the only reason it had side effects is that it was another
4285 similar SAVE_EXPR, but that isn't worth bothering with. */
4286 if (SAVE_EXPR_RTL (t) == 0 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0))
4287 && 0 != (t1 = extract_muldiv (TREE_OPERAND (t, 0), c, code,
4290 t1 = save_expr (t1);
4291 if (SAVE_EXPR_PERSISTENT_P (t) && TREE_CODE (t1) == SAVE_EXPR)
4292 SAVE_EXPR_PERSISTENT_P (t1) = 1;
4293 if (is_pending_size (t))
4294 put_pending_size (t1);
4299 case LSHIFT_EXPR: case RSHIFT_EXPR:
4300 /* If the second operand is constant, this is a multiplication
4301 or floor division, by a power of two, so we can treat it that
4302 way unless the multiplier or divisor overflows. */
4303 if (TREE_CODE (op1) == INTEGER_CST
4304 /* const_binop may not detect overflow correctly,
4305 so check for it explicitly here. */
4306 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
4307 && TREE_INT_CST_HIGH (op1) == 0
4308 && 0 != (t1 = convert (ctype,
4309 const_binop (LSHIFT_EXPR, size_one_node,
4311 && ! TREE_OVERFLOW (t1))
4312 return extract_muldiv (build (tcode == LSHIFT_EXPR
4313 ? MULT_EXPR : FLOOR_DIV_EXPR,
4314 ctype, convert (ctype, op0), t1),
4315 c, code, wide_type);
4318 case PLUS_EXPR: case MINUS_EXPR:
4319 /* See if we can eliminate the operation on both sides. If we can, we
4320 can return a new PLUS or MINUS. If we can't, the only remaining
4321 cases where we can do anything are if the second operand is a
4323 t1 = extract_muldiv (op0, c, code, wide_type);
4324 t2 = extract_muldiv (op1, c, code, wide_type);
4325 if (t1 != 0 && t2 != 0
4326 && (code == MULT_EXPR
4327 /* If not multiplication, we can only do this if both operands
4328 are divisible by c. */
4329 || (multiple_of_p (ctype, op0, c)
4330 && multiple_of_p (ctype, op1, c))))
4331 return fold (build (tcode, ctype, convert (ctype, t1),
4332 convert (ctype, t2)));
4334 /* If this was a subtraction, negate OP1 and set it to be an addition.
4335 This simplifies the logic below. */
4336 if (tcode == MINUS_EXPR)
4337 tcode = PLUS_EXPR, op1 = negate_expr (op1);
4339 if (TREE_CODE (op1) != INTEGER_CST)
4342 /* If either OP1 or C are negative, this optimization is not safe for
4343 some of the division and remainder types while for others we need
4344 to change the code. */
4345 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
4347 if (code == CEIL_DIV_EXPR)
4348 code = FLOOR_DIV_EXPR;
4349 else if (code == FLOOR_DIV_EXPR)
4350 code = CEIL_DIV_EXPR;
4351 else if (code != MULT_EXPR
4352 && code != CEIL_MOD_EXPR && code != FLOOR_MOD_EXPR)
4356 /* If it's a multiply or a division/modulus operation of a multiple
4357 of our constant, do the operation and verify it doesn't overflow. */
4358 if (code == MULT_EXPR
4359 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4361 op1 = const_binop (code, convert (ctype, op1), convert (ctype, c), 0);
4362 if (op1 == 0 || TREE_OVERFLOW (op1))
4368 /* If we have an unsigned type is not a sizetype, we cannot widen
4369 the operation since it will change the result if the original
4370 computation overflowed. */
4371 if (TREE_UNSIGNED (ctype)
4372 && ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
4376 /* If we were able to eliminate our operation from the first side,
4377 apply our operation to the second side and reform the PLUS. */
4378 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
4379 return fold (build (tcode, ctype, convert (ctype, t1), op1));
4381 /* The last case is if we are a multiply. In that case, we can
4382 apply the distributive law to commute the multiply and addition
4383 if the multiplication of the constants doesn't overflow. */
4384 if (code == MULT_EXPR)
4385 return fold (build (tcode, ctype, fold (build (code, ctype,
4386 convert (ctype, op0),
4387 convert (ctype, c))),
4393 /* We have a special case here if we are doing something like
4394 (C * 8) % 4 since we know that's zero. */
4395 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
4396 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
4397 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
4398 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4399 return omit_one_operand (type, integer_zero_node, op0);
4401 /* ... fall through ... */
4403 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
4404 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
4405 /* If we can extract our operation from the LHS, do so and return a
4406 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
4407 do something only if the second operand is a constant. */
4409 && (t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4410 return fold (build (tcode, ctype, convert (ctype, t1),
4411 convert (ctype, op1)));
4412 else if (tcode == MULT_EXPR && code == MULT_EXPR
4413 && (t1 = extract_muldiv (op1, c, code, wide_type)) != 0)
4414 return fold (build (tcode, ctype, convert (ctype, op0),
4415 convert (ctype, t1)));
4416 else if (TREE_CODE (op1) != INTEGER_CST)
4419 /* If these are the same operation types, we can associate them
4420 assuming no overflow. */
4422 && 0 != (t1 = const_binop (MULT_EXPR, convert (ctype, op1),
4423 convert (ctype, c), 0))
4424 && ! TREE_OVERFLOW (t1))
4425 return fold (build (tcode, ctype, convert (ctype, op0), t1));
4427 /* If these operations "cancel" each other, we have the main
4428 optimizations of this pass, which occur when either constant is a
4429 multiple of the other, in which case we replace this with either an
4430 operation or CODE or TCODE.
4432 If we have an unsigned type that is not a sizetype, we cannot do
4433 this since it will change the result if the original computation
4435 if ((! TREE_UNSIGNED (ctype)
4436 || (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
4438 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
4439 || (tcode == MULT_EXPR
4440 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
4441 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR)))
4443 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4444 return fold (build (tcode, ctype, convert (ctype, op0),
4446 const_binop (TRUNC_DIV_EXPR,
4448 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
4449 return fold (build (code, ctype, convert (ctype, op0),
4451 const_binop (TRUNC_DIV_EXPR,
4463 /* If T contains a COMPOUND_EXPR which was inserted merely to evaluate
4464 S, a SAVE_EXPR, return the expression actually being evaluated. Note
4465 that we may sometimes modify the tree. */
4468 strip_compound_expr (t, s)
4472 enum tree_code code = TREE_CODE (t);
4474 /* See if this is the COMPOUND_EXPR we want to eliminate. */
4475 if (code == COMPOUND_EXPR && TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR
4476 && TREE_OPERAND (TREE_OPERAND (t, 0), 0) == s)
4477 return TREE_OPERAND (t, 1);
4479 /* See if this is a COND_EXPR or a simple arithmetic operator. We
4480 don't bother handling any other types. */
4481 else if (code == COND_EXPR)
4483 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4484 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4485 TREE_OPERAND (t, 2) = strip_compound_expr (TREE_OPERAND (t, 2), s);
4487 else if (TREE_CODE_CLASS (code) == '1')
4488 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4489 else if (TREE_CODE_CLASS (code) == '<'
4490 || TREE_CODE_CLASS (code) == '2')
4492 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4493 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4499 /* Return a node which has the indicated constant VALUE (either 0 or
4500 1), and is of the indicated TYPE. */
4503 constant_boolean_node (value, type)
4507 if (type == integer_type_node)
4508 return value ? integer_one_node : integer_zero_node;
4509 else if (TREE_CODE (type) == BOOLEAN_TYPE)
4510 return (*lang_hooks.truthvalue_conversion) (value ? integer_one_node :
4514 tree t = build_int_2 (value, 0);
4516 TREE_TYPE (t) = type;
4521 /* Utility function for the following routine, to see how complex a nesting of
4522 COND_EXPRs can be. EXPR is the expression and LIMIT is a count beyond which
4523 we don't care (to avoid spending too much time on complex expressions.). */
4526 count_cond (expr, lim)
4532 if (TREE_CODE (expr) != COND_EXPR)
4537 ctrue = count_cond (TREE_OPERAND (expr, 1), lim - 1);
4538 cfalse = count_cond (TREE_OPERAND (expr, 2), lim - 1 - ctrue);
4539 return MIN (lim, 1 + ctrue + cfalse);
4542 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
4543 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
4544 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
4545 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
4546 COND is the first argument to CODE; otherwise (as in the example
4547 given here), it is the second argument. TYPE is the type of the
4548 original expression. */
4551 fold_binary_op_with_conditional_arg (code, type, cond, arg, cond_first_p)
4552 enum tree_code code;
4558 tree test, true_value, false_value;
4559 tree lhs = NULL_TREE;
4560 tree rhs = NULL_TREE;
4561 /* In the end, we'll produce a COND_EXPR. Both arms of the
4562 conditional expression will be binary operations. The left-hand
4563 side of the expression to be executed if the condition is true
4564 will be pointed to by TRUE_LHS. Similarly, the right-hand side
4565 of the expression to be executed if the condition is true will be
4566 pointed to by TRUE_RHS. FALSE_LHS and FALSE_RHS are analogous --
4567 but apply to the expression to be executed if the conditional is
4573 /* These are the codes to use for the left-hand side and right-hand
4574 side of the COND_EXPR. Normally, they are the same as CODE. */
4575 enum tree_code lhs_code = code;
4576 enum tree_code rhs_code = code;
4577 /* And these are the types of the expressions. */
4578 tree lhs_type = type;
4579 tree rhs_type = type;
4584 true_rhs = false_rhs = &arg;
4585 true_lhs = &true_value;
4586 false_lhs = &false_value;
4590 true_lhs = false_lhs = &arg;
4591 true_rhs = &true_value;
4592 false_rhs = &false_value;
4595 if (TREE_CODE (cond) == COND_EXPR)
4597 test = TREE_OPERAND (cond, 0);
4598 true_value = TREE_OPERAND (cond, 1);
4599 false_value = TREE_OPERAND (cond, 2);
4600 /* If this operand throws an expression, then it does not make
4601 sense to try to perform a logical or arithmetic operation
4602 involving it. Instead of building `a + throw 3' for example,
4603 we simply build `a, throw 3'. */
4604 if (VOID_TYPE_P (TREE_TYPE (true_value)))
4608 lhs_code = COMPOUND_EXPR;
4609 lhs_type = void_type_node;
4614 if (VOID_TYPE_P (TREE_TYPE (false_value)))
4618 rhs_code = COMPOUND_EXPR;
4619 rhs_type = void_type_node;
4627 tree testtype = TREE_TYPE (cond);
4629 true_value = convert (testtype, integer_one_node);
4630 false_value = convert (testtype, integer_zero_node);
4633 /* If ARG is complex we want to make sure we only evaluate it once. Though
4634 this is only required if it is volatile, it might be more efficient even
4635 if it is not. However, if we succeed in folding one part to a constant,
4636 we do not need to make this SAVE_EXPR. Since we do this optimization
4637 primarily to see if we do end up with constant and this SAVE_EXPR
4638 interferes with later optimizations, suppressing it when we can is
4641 If we are not in a function, we can't make a SAVE_EXPR, so don't try to
4642 do so. Don't try to see if the result is a constant if an arm is a
4643 COND_EXPR since we get exponential behavior in that case. */
4645 if (saved_expr_p (arg))
4647 else if (lhs == 0 && rhs == 0
4648 && !TREE_CONSTANT (arg)
4649 && (*lang_hooks.decls.global_bindings_p) () == 0
4650 && ((TREE_CODE (arg) != VAR_DECL && TREE_CODE (arg) != PARM_DECL)
4651 || TREE_SIDE_EFFECTS (arg)))
4653 if (TREE_CODE (true_value) != COND_EXPR)
4654 lhs = fold (build (lhs_code, lhs_type, *true_lhs, *true_rhs));
4656 if (TREE_CODE (false_value) != COND_EXPR)
4657 rhs = fold (build (rhs_code, rhs_type, *false_lhs, *false_rhs));
4659 if ((lhs == 0 || ! TREE_CONSTANT (lhs))
4660 && (rhs == 0 || !TREE_CONSTANT (rhs)))
4662 arg = save_expr (arg);
4669 lhs = fold (build (lhs_code, lhs_type, *true_lhs, *true_rhs));
4671 rhs = fold (build (rhs_code, rhs_type, *false_lhs, *false_rhs));
4673 test = fold (build (COND_EXPR, type, test, lhs, rhs));
4676 return build (COMPOUND_EXPR, type,
4677 convert (void_type_node, arg),
4678 strip_compound_expr (test, arg));
4680 return convert (type, test);
4684 /* Subroutine of fold() that checks for the addition of +/- 0.0.
4686 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
4687 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
4688 ADDEND is the same as X.
4690 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
4691 and finite. The problematic cases are when X is zero, and its mode
4692 has signed zeros. In the case of rounding towards -infinity,
4693 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
4694 modes, X + 0 is not the same as X because -0 + 0 is 0. */
4697 fold_real_zero_addition_p (type, addend, negate)
4701 if (!real_zerop (addend))
4704 /* Don't allow the fold with -fsignaling-nans. */
4705 if (HONOR_SNANS (TYPE_MODE (type)))
4708 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
4709 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
4712 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
4713 if (TREE_CODE (addend) == REAL_CST
4714 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
4717 /* The mode has signed zeros, and we have to honor their sign.
4718 In this situation, there is only one case we can return true for.
4719 X - 0 is the same as X unless rounding towards -infinity is
4721 return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
4724 /* Subroutine of fold() that checks comparisons of built-in math
4725 functions against real constants.
4727 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
4728 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
4729 is the type of the result and ARG0 and ARG1 are the operands of the
4730 comparison. ARG1 must be a TREE_REAL_CST.
4732 The function returns the constant folded tree if a simplification
4733 can be made, and NULL_TREE otherwise. */
4736 fold_mathfn_compare (fcode, code, type, arg0, arg1)
4737 enum built_in_function fcode;
4738 enum tree_code code;
4739 tree type, arg0, arg1;
4743 if (fcode == BUILT_IN_SQRT
4744 || fcode == BUILT_IN_SQRTF
4745 || fcode == BUILT_IN_SQRTL)
4747 tree arg = TREE_VALUE (TREE_OPERAND (arg0, 1));
4748 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg0));
4750 c = TREE_REAL_CST (arg1);
4751 if (REAL_VALUE_NEGATIVE (c))
4753 /* sqrt(x) < y is always false, if y is negative. */
4754 if (code == EQ_EXPR || code == LT_EXPR || code == LE_EXPR)
4755 return omit_one_operand (type,
4756 convert (type, integer_zero_node),
4759 /* sqrt(x) > y is always true, if y is negative and we
4760 don't care about NaNs, i.e. negative values of x. */
4761 if (code == NE_EXPR || !HONOR_NANS (mode))
4762 return omit_one_operand (type,
4763 convert (type, integer_one_node),
4766 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
4767 return fold (build (GE_EXPR, type, arg,
4768 build_real (TREE_TYPE (arg), dconst0)));
4770 else if (code == GT_EXPR || code == GE_EXPR)
4774 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
4775 real_convert (&c2, mode, &c2);
4777 if (REAL_VALUE_ISINF (c2))
4779 /* sqrt(x) > y is x == +Inf, when y is very large. */
4780 if (HONOR_INFINITIES (mode))
4781 return fold (build (EQ_EXPR, type, arg,
4782 build_real (TREE_TYPE (arg), c2)));
4784 /* sqrt(x) > y is always false, when y is very large
4785 and we don't care about infinities. */
4786 return omit_one_operand (type,
4787 convert (type, integer_zero_node),
4791 /* sqrt(x) > c is the same as x > c*c. */
4792 return fold (build (code, type, arg,
4793 build_real (TREE_TYPE (arg), c2)));
4795 else if (code == LT_EXPR || code == LE_EXPR)
4799 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
4800 real_convert (&c2, mode, &c2);
4802 if (REAL_VALUE_ISINF (c2))
4804 /* sqrt(x) < y is always true, when y is a very large
4805 value and we don't care about NaNs or Infinities. */
4806 if (! HONOR_NANS (mode) && ! HONOR_INFINITIES (mode))
4807 return omit_one_operand (type,
4808 convert (type, integer_one_node),
4811 /* sqrt(x) < y is x != +Inf when y is very large and we
4812 don't care about NaNs. */
4813 if (! HONOR_NANS (mode))
4814 return fold (build (NE_EXPR, type, arg,
4815 build_real (TREE_TYPE (arg), c2)));
4817 /* sqrt(x) < y is x >= 0 when y is very large and we
4818 don't care about Infinities. */
4819 if (! HONOR_INFINITIES (mode))
4820 return fold (build (GE_EXPR, type, arg,
4821 build_real (TREE_TYPE (arg), dconst0)));
4823 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
4824 if ((*lang_hooks.decls.global_bindings_p) () != 0
4825 || CONTAINS_PLACEHOLDER_P (arg))
4828 arg = save_expr (arg);
4829 return fold (build (TRUTH_ANDIF_EXPR, type,
4830 fold (build (GE_EXPR, type, arg,
4831 build_real (TREE_TYPE (arg),
4833 fold (build (NE_EXPR, type, arg,
4834 build_real (TREE_TYPE (arg),
4838 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
4839 if (! HONOR_NANS (mode))
4840 return fold (build (code, type, arg,
4841 build_real (TREE_TYPE (arg), c2)));
4843 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
4844 if ((*lang_hooks.decls.global_bindings_p) () == 0
4845 && ! CONTAINS_PLACEHOLDER_P (arg))
4847 arg = save_expr (arg);
4848 return fold (build (TRUTH_ANDIF_EXPR, type,
4849 fold (build (GE_EXPR, type, arg,
4850 build_real (TREE_TYPE (arg),
4852 fold (build (code, type, arg,
4853 build_real (TREE_TYPE (arg),
4862 /* Subroutine of fold() that optimizes comparisons against Infinities,
4863 either +Inf or -Inf.
4865 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
4866 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
4867 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
4869 The function returns the constant folded tree if a simplification
4870 can be made, and NULL_TREE otherwise. */
4873 fold_inf_compare (code, type, arg0, arg1)
4874 enum tree_code code;
4875 tree type, arg0, arg1;
4877 enum machine_mode mode;
4878 REAL_VALUE_TYPE max;
4882 mode = TYPE_MODE (TREE_TYPE (arg0));
4884 /* For negative infinity swap the sense of the comparison. */
4885 neg = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1));
4887 code = swap_tree_comparison (code);
4892 /* x > +Inf is always false, if with ignore sNANs. */
4893 if (HONOR_SNANS (mode))
4895 return omit_one_operand (type,
4896 convert (type, integer_zero_node),
4900 /* x <= +Inf is always true, if we don't case about NaNs. */
4901 if (! HONOR_NANS (mode))
4902 return omit_one_operand (type,
4903 convert (type, integer_one_node),
4906 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
4907 if ((*lang_hooks.decls.global_bindings_p) () == 0
4908 && ! CONTAINS_PLACEHOLDER_P (arg0))
4910 arg0 = save_expr (arg0);
4911 return fold (build (EQ_EXPR, type, arg0, arg0));
4917 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
4918 real_maxval (&max, neg, mode);
4919 return fold (build (neg ? LT_EXPR : GT_EXPR, type,
4920 arg0, build_real (TREE_TYPE (arg0), max)));
4923 /* x < +Inf is always equal to x <= DBL_MAX. */
4924 real_maxval (&max, neg, mode);
4925 return fold (build (neg ? GE_EXPR : LE_EXPR, type,
4926 arg0, build_real (TREE_TYPE (arg0), max)));
4929 /* x != +Inf is always equal to !(x > DBL_MAX). */
4930 real_maxval (&max, neg, mode);
4931 if (! HONOR_NANS (mode))
4932 return fold (build (neg ? GE_EXPR : LE_EXPR, type,
4933 arg0, build_real (TREE_TYPE (arg0), max)));
4934 temp = fold (build (neg ? LT_EXPR : GT_EXPR, type,
4935 arg0, build_real (TREE_TYPE (arg0), max)));
4936 return fold (build1 (TRUTH_NOT_EXPR, type, temp));
4945 /* Perform constant folding and related simplification of EXPR.
4946 The related simplifications include x*1 => x, x*0 => 0, etc.,
4947 and application of the associative law.
4948 NOP_EXPR conversions may be removed freely (as long as we
4949 are careful not to change the C type of the overall expression)
4950 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
4951 but we can constant-fold them if they have constant operands. */
4958 tree t1 = NULL_TREE;
4960 tree type = TREE_TYPE (expr);
4961 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
4962 enum tree_code code = TREE_CODE (t);
4963 int kind = TREE_CODE_CLASS (code);
4965 /* WINS will be nonzero when the switch is done
4966 if all operands are constant. */
4969 /* Don't try to process an RTL_EXPR since its operands aren't trees.
4970 Likewise for a SAVE_EXPR that's already been evaluated. */
4971 if (code == RTL_EXPR || (code == SAVE_EXPR && SAVE_EXPR_RTL (t) != 0))
4974 /* Return right away if a constant. */
4978 #ifdef MAX_INTEGER_COMPUTATION_MODE
4979 check_max_integer_computation_mode (expr);
4982 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
4986 /* Special case for conversion ops that can have fixed point args. */
4987 arg0 = TREE_OPERAND (t, 0);
4989 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
4991 STRIP_SIGN_NOPS (arg0);
4993 if (arg0 != 0 && TREE_CODE (arg0) == COMPLEX_CST)
4994 subop = TREE_REALPART (arg0);
4998 if (subop != 0 && TREE_CODE (subop) != INTEGER_CST
4999 && TREE_CODE (subop) != REAL_CST
5001 /* Note that TREE_CONSTANT isn't enough:
5002 static var addresses are constant but we can't
5003 do arithmetic on them. */
5006 else if (IS_EXPR_CODE_CLASS (kind) || kind == 'r')
5008 int len = first_rtl_op (code);
5010 for (i = 0; i < len; i++)
5012 tree op = TREE_OPERAND (t, i);
5016 continue; /* Valid for CALL_EXPR, at least. */
5018 if (kind == '<' || code == RSHIFT_EXPR)
5020 /* Signedness matters here. Perhaps we can refine this
5022 STRIP_SIGN_NOPS (op);
5025 /* Strip any conversions that don't change the mode. */
5028 if (TREE_CODE (op) == COMPLEX_CST)
5029 subop = TREE_REALPART (op);
5033 if (TREE_CODE (subop) != INTEGER_CST
5034 && TREE_CODE (subop) != REAL_CST)
5035 /* Note that TREE_CONSTANT isn't enough:
5036 static var addresses are constant but we can't
5037 do arithmetic on them. */
5047 /* If this is a commutative operation, and ARG0 is a constant, move it
5048 to ARG1 to reduce the number of tests below. */
5049 if ((code == PLUS_EXPR || code == MULT_EXPR || code == MIN_EXPR
5050 || code == MAX_EXPR || code == BIT_IOR_EXPR || code == BIT_XOR_EXPR
5051 || code == BIT_AND_EXPR)
5052 && (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST))
5054 tem = arg0; arg0 = arg1; arg1 = tem;
5056 tem = TREE_OPERAND (t, 0); TREE_OPERAND (t, 0) = TREE_OPERAND (t, 1);
5057 TREE_OPERAND (t, 1) = tem;
5060 /* Now WINS is set as described above,
5061 ARG0 is the first operand of EXPR,
5062 and ARG1 is the second operand (if it has more than one operand).
5064 First check for cases where an arithmetic operation is applied to a
5065 compound, conditional, or comparison operation. Push the arithmetic
5066 operation inside the compound or conditional to see if any folding
5067 can then be done. Convert comparison to conditional for this purpose.
5068 The also optimizes non-constant cases that used to be done in
5071 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
5072 one of the operands is a comparison and the other is a comparison, a
5073 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
5074 code below would make the expression more complex. Change it to a
5075 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
5076 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
5078 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
5079 || code == EQ_EXPR || code == NE_EXPR)
5080 && ((truth_value_p (TREE_CODE (arg0))
5081 && (truth_value_p (TREE_CODE (arg1))
5082 || (TREE_CODE (arg1) == BIT_AND_EXPR
5083 && integer_onep (TREE_OPERAND (arg1, 1)))))
5084 || (truth_value_p (TREE_CODE (arg1))
5085 && (truth_value_p (TREE_CODE (arg0))
5086 || (TREE_CODE (arg0) == BIT_AND_EXPR
5087 && integer_onep (TREE_OPERAND (arg0, 1)))))))
5089 t = fold (build (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
5090 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
5094 if (code == EQ_EXPR)
5095 t = invert_truthvalue (t);
5100 if (TREE_CODE_CLASS (code) == '1')
5102 if (TREE_CODE (arg0) == COMPOUND_EXPR)
5103 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5104 fold (build1 (code, type, TREE_OPERAND (arg0, 1))));
5105 else if (TREE_CODE (arg0) == COND_EXPR)
5107 tree arg01 = TREE_OPERAND (arg0, 1);
5108 tree arg02 = TREE_OPERAND (arg0, 2);
5109 if (! VOID_TYPE_P (TREE_TYPE (arg01)))
5110 arg01 = fold (build1 (code, type, arg01));
5111 if (! VOID_TYPE_P (TREE_TYPE (arg02)))
5112 arg02 = fold (build1 (code, type, arg02));
5113 t = fold (build (COND_EXPR, type, TREE_OPERAND (arg0, 0),
5116 /* If this was a conversion, and all we did was to move into
5117 inside the COND_EXPR, bring it back out. But leave it if
5118 it is a conversion from integer to integer and the
5119 result precision is no wider than a word since such a
5120 conversion is cheap and may be optimized away by combine,
5121 while it couldn't if it were outside the COND_EXPR. Then return
5122 so we don't get into an infinite recursion loop taking the
5123 conversion out and then back in. */
5125 if ((code == NOP_EXPR || code == CONVERT_EXPR
5126 || code == NON_LVALUE_EXPR)
5127 && TREE_CODE (t) == COND_EXPR
5128 && TREE_CODE (TREE_OPERAND (t, 1)) == code
5129 && TREE_CODE (TREE_OPERAND (t, 2)) == code
5130 && ! VOID_TYPE_P (TREE_OPERAND (t, 1))
5131 && ! VOID_TYPE_P (TREE_OPERAND (t, 2))
5132 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))
5133 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 2), 0)))
5134 && ! (INTEGRAL_TYPE_P (TREE_TYPE (t))
5136 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))))
5137 && TYPE_PRECISION (TREE_TYPE (t)) <= BITS_PER_WORD))
5138 t = build1 (code, type,
5140 TREE_TYPE (TREE_OPERAND
5141 (TREE_OPERAND (t, 1), 0)),
5142 TREE_OPERAND (t, 0),
5143 TREE_OPERAND (TREE_OPERAND (t, 1), 0),
5144 TREE_OPERAND (TREE_OPERAND (t, 2), 0)));
5147 else if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<')
5148 return fold (build (COND_EXPR, type, arg0,
5149 fold (build1 (code, type, integer_one_node)),
5150 fold (build1 (code, type, integer_zero_node))));
5152 else if (TREE_CODE_CLASS (code) == '<'
5153 && TREE_CODE (arg0) == COMPOUND_EXPR)
5154 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5155 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
5156 else if (TREE_CODE_CLASS (code) == '<'
5157 && TREE_CODE (arg1) == COMPOUND_EXPR)
5158 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
5159 fold (build (code, type, arg0, TREE_OPERAND (arg1, 1))));
5160 else if (TREE_CODE_CLASS (code) == '2'
5161 || TREE_CODE_CLASS (code) == '<')
5163 if (TREE_CODE (arg1) == COMPOUND_EXPR
5164 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg1, 0))
5165 && ! TREE_SIDE_EFFECTS (arg0))
5166 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
5167 fold (build (code, type,
5168 arg0, TREE_OPERAND (arg1, 1))));
5169 else if ((TREE_CODE (arg1) == COND_EXPR
5170 || (TREE_CODE_CLASS (TREE_CODE (arg1)) == '<'
5171 && TREE_CODE_CLASS (code) != '<'))
5172 && (TREE_CODE (arg0) != COND_EXPR
5173 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
5174 && (! TREE_SIDE_EFFECTS (arg0)
5175 || ((*lang_hooks.decls.global_bindings_p) () == 0
5176 && ! CONTAINS_PLACEHOLDER_P (arg0))))
5178 fold_binary_op_with_conditional_arg (code, type, arg1, arg0,
5179 /*cond_first_p=*/0);
5180 else if (TREE_CODE (arg0) == COMPOUND_EXPR)
5181 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5182 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
5183 else if ((TREE_CODE (arg0) == COND_EXPR
5184 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
5185 && TREE_CODE_CLASS (code) != '<'))
5186 && (TREE_CODE (arg1) != COND_EXPR
5187 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
5188 && (! TREE_SIDE_EFFECTS (arg1)
5189 || ((*lang_hooks.decls.global_bindings_p) () == 0
5190 && ! CONTAINS_PLACEHOLDER_P (arg1))))
5192 fold_binary_op_with_conditional_arg (code, type, arg0, arg1,
5193 /*cond_first_p=*/1);
5207 return fold (DECL_INITIAL (t));
5212 case FIX_TRUNC_EXPR:
5213 /* Other kinds of FIX are not handled properly by fold_convert. */
5215 if (TREE_TYPE (TREE_OPERAND (t, 0)) == TREE_TYPE (t))
5216 return TREE_OPERAND (t, 0);
5218 /* Handle cases of two conversions in a row. */
5219 if (TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
5220 || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR)
5222 tree inside_type = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5223 tree inter_type = TREE_TYPE (TREE_OPERAND (t, 0));
5224 tree final_type = TREE_TYPE (t);
5225 int inside_int = INTEGRAL_TYPE_P (inside_type);
5226 int inside_ptr = POINTER_TYPE_P (inside_type);
5227 int inside_float = FLOAT_TYPE_P (inside_type);
5228 unsigned int inside_prec = TYPE_PRECISION (inside_type);
5229 int inside_unsignedp = TREE_UNSIGNED (inside_type);
5230 int inter_int = INTEGRAL_TYPE_P (inter_type);
5231 int inter_ptr = POINTER_TYPE_P (inter_type);
5232 int inter_float = FLOAT_TYPE_P (inter_type);
5233 unsigned int inter_prec = TYPE_PRECISION (inter_type);
5234 int inter_unsignedp = TREE_UNSIGNED (inter_type);
5235 int final_int = INTEGRAL_TYPE_P (final_type);
5236 int final_ptr = POINTER_TYPE_P (final_type);
5237 int final_float = FLOAT_TYPE_P (final_type);
5238 unsigned int final_prec = TYPE_PRECISION (final_type);
5239 int final_unsignedp = TREE_UNSIGNED (final_type);
5241 /* In addition to the cases of two conversions in a row
5242 handled below, if we are converting something to its own
5243 type via an object of identical or wider precision, neither
5244 conversion is needed. */
5245 if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (final_type)
5246 && ((inter_int && final_int) || (inter_float && final_float))
5247 && inter_prec >= final_prec)
5248 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5250 /* Likewise, if the intermediate and final types are either both
5251 float or both integer, we don't need the middle conversion if
5252 it is wider than the final type and doesn't change the signedness
5253 (for integers). Avoid this if the final type is a pointer
5254 since then we sometimes need the inner conversion. Likewise if
5255 the outer has a precision not equal to the size of its mode. */
5256 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
5257 || (inter_float && inside_float))
5258 && inter_prec >= inside_prec
5259 && (inter_float || inter_unsignedp == inside_unsignedp)
5260 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
5261 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
5263 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5265 /* If we have a sign-extension of a zero-extended value, we can
5266 replace that by a single zero-extension. */
5267 if (inside_int && inter_int && final_int
5268 && inside_prec < inter_prec && inter_prec < final_prec
5269 && inside_unsignedp && !inter_unsignedp)
5270 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5272 /* Two conversions in a row are not needed unless:
5273 - some conversion is floating-point (overstrict for now), or
5274 - the intermediate type is narrower than both initial and
5276 - the intermediate type and innermost type differ in signedness,
5277 and the outermost type is wider than the intermediate, or
5278 - the initial type is a pointer type and the precisions of the
5279 intermediate and final types differ, or
5280 - the final type is a pointer type and the precisions of the
5281 initial and intermediate types differ. */
5282 if (! inside_float && ! inter_float && ! final_float
5283 && (inter_prec > inside_prec || inter_prec > final_prec)
5284 && ! (inside_int && inter_int
5285 && inter_unsignedp != inside_unsignedp
5286 && inter_prec < final_prec)
5287 && ((inter_unsignedp && inter_prec > inside_prec)
5288 == (final_unsignedp && final_prec > inter_prec))
5289 && ! (inside_ptr && inter_prec != final_prec)
5290 && ! (final_ptr && inside_prec != inter_prec)
5291 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
5292 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
5294 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5297 if (TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR
5298 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t, 0), 1))
5299 /* Detect assigning a bitfield. */
5300 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) == COMPONENT_REF
5301 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 1))))
5303 /* Don't leave an assignment inside a conversion
5304 unless assigning a bitfield. */
5305 tree prev = TREE_OPERAND (t, 0);
5306 TREE_OPERAND (t, 0) = TREE_OPERAND (prev, 1);
5307 /* First do the assignment, then return converted constant. */
5308 t = build (COMPOUND_EXPR, TREE_TYPE (t), prev, fold (t));
5313 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
5314 constants (if x has signed type, the sign bit cannot be set
5315 in c). This folds extension into the BIT_AND_EXPR. */
5316 if (INTEGRAL_TYPE_P (TREE_TYPE (t))
5317 && TREE_CODE (TREE_TYPE (t)) != BOOLEAN_TYPE
5318 && TREE_CODE (TREE_OPERAND (t, 0)) == BIT_AND_EXPR
5319 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 1)) == INTEGER_CST)
5321 tree and = TREE_OPERAND (t, 0);
5322 tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
5325 if (TREE_UNSIGNED (TREE_TYPE (and))
5326 || (TYPE_PRECISION (TREE_TYPE (t))
5327 <= TYPE_PRECISION (TREE_TYPE (and))))
5329 else if (TYPE_PRECISION (TREE_TYPE (and1))
5330 <= HOST_BITS_PER_WIDE_INT
5331 && host_integerp (and1, 1))
5333 unsigned HOST_WIDE_INT cst;
5335 cst = tree_low_cst (and1, 1);
5336 cst &= (HOST_WIDE_INT) -1
5337 << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
5338 change = (cst == 0);
5339 #ifdef LOAD_EXTEND_OP
5341 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
5344 tree uns = (*lang_hooks.types.unsigned_type) (TREE_TYPE (and0));
5345 and0 = convert (uns, and0);
5346 and1 = convert (uns, and1);
5351 return fold (build (BIT_AND_EXPR, TREE_TYPE (t),
5352 convert (TREE_TYPE (t), and0),
5353 convert (TREE_TYPE (t), and1)));
5358 TREE_CONSTANT (t) = TREE_CONSTANT (arg0);
5361 return fold_convert (t, arg0);
5363 case VIEW_CONVERT_EXPR:
5364 if (TREE_CODE (TREE_OPERAND (t, 0)) == VIEW_CONVERT_EXPR)
5365 return build1 (VIEW_CONVERT_EXPR, type,
5366 TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5370 if (TREE_CODE (arg0) == CONSTRUCTOR
5371 && ! type_contains_placeholder_p (TREE_TYPE (arg0)))
5373 tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0));
5380 TREE_CONSTANT (t) = wins;
5386 if (TREE_CODE (arg0) == INTEGER_CST)
5388 unsigned HOST_WIDE_INT low;
5390 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
5391 TREE_INT_CST_HIGH (arg0),
5393 t = build_int_2 (low, high);
5394 TREE_TYPE (t) = type;
5396 = (TREE_OVERFLOW (arg0)
5397 | force_fit_type (t, overflow && !TREE_UNSIGNED (type)));
5398 TREE_CONSTANT_OVERFLOW (t)
5399 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
5401 else if (TREE_CODE (arg0) == REAL_CST)
5402 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
5404 else if (TREE_CODE (arg0) == NEGATE_EXPR)
5405 return TREE_OPERAND (arg0, 0);
5406 /* Convert -((double)float) into (double)(-float). */
5407 else if (TREE_CODE (arg0) == NOP_EXPR
5408 && TREE_CODE (type) == REAL_TYPE)
5410 tree targ0 = strip_float_extensions (arg0);
5412 return convert (type, build1 (NEGATE_EXPR, TREE_TYPE (targ0), targ0));
5416 /* Convert - (a - b) to (b - a) for non-floating-point. */
5417 else if (TREE_CODE (arg0) == MINUS_EXPR
5418 && (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
5419 return build (MINUS_EXPR, type, TREE_OPERAND (arg0, 1),
5420 TREE_OPERAND (arg0, 0));
5422 /* Convert -f(x) into f(-x) where f is sin, tan or atan. */
5423 switch (builtin_mathfn_code (arg0))
5432 case BUILT_IN_ATANF:
5433 case BUILT_IN_ATANL:
5434 if (negate_expr_p (TREE_VALUE (TREE_OPERAND (arg0, 1))))
5436 tree fndecl, arg, arglist;
5438 fndecl = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
5439 arg = TREE_VALUE (TREE_OPERAND (arg0, 1));
5440 arg = fold (build1 (NEGATE_EXPR, type, arg));
5441 arglist = build_tree_list (NULL_TREE, arg);
5442 return build_function_call_expr (fndecl, arglist);
5454 if (TREE_CODE (arg0) == INTEGER_CST)
5456 /* If the value is unsigned, then the absolute value is
5457 the same as the ordinary value. */
5458 if (TREE_UNSIGNED (type))
5460 /* Similarly, if the value is non-negative. */
5461 else if (INT_CST_LT (integer_minus_one_node, arg0))
5463 /* If the value is negative, then the absolute value is
5467 unsigned HOST_WIDE_INT low;
5469 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
5470 TREE_INT_CST_HIGH (arg0),
5472 t = build_int_2 (low, high);
5473 TREE_TYPE (t) = type;
5475 = (TREE_OVERFLOW (arg0)
5476 | force_fit_type (t, overflow));
5477 TREE_CONSTANT_OVERFLOW (t)
5478 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
5481 else if (TREE_CODE (arg0) == REAL_CST)
5483 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
5484 t = build_real (type,
5485 REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
5488 else if (TREE_CODE (arg0) == NEGATE_EXPR)
5489 return fold (build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0)));
5490 /* Convert fabs((double)float) into (double)fabsf(float). */
5491 else if (TREE_CODE (arg0) == NOP_EXPR
5492 && TREE_CODE (type) == REAL_TYPE)
5494 tree targ0 = strip_float_extensions (arg0);
5496 return convert (type, fold (build1 (ABS_EXPR, TREE_TYPE (targ0),
5499 else if (tree_expr_nonnegative_p (arg0))
5504 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
5505 return convert (type, arg0);
5506 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
5507 return build (COMPLEX_EXPR, type,
5508 TREE_OPERAND (arg0, 0),
5509 negate_expr (TREE_OPERAND (arg0, 1)));
5510 else if (TREE_CODE (arg0) == COMPLEX_CST)
5511 return build_complex (type, TREE_REALPART (arg0),
5512 negate_expr (TREE_IMAGPART (arg0)));
5513 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
5514 return fold (build (TREE_CODE (arg0), type,
5515 fold (build1 (CONJ_EXPR, type,
5516 TREE_OPERAND (arg0, 0))),
5517 fold (build1 (CONJ_EXPR,
5518 type, TREE_OPERAND (arg0, 1)))));
5519 else if (TREE_CODE (arg0) == CONJ_EXPR)
5520 return TREE_OPERAND (arg0, 0);
5526 t = build_int_2 (~ TREE_INT_CST_LOW (arg0),
5527 ~ TREE_INT_CST_HIGH (arg0));
5528 TREE_TYPE (t) = type;
5529 force_fit_type (t, 0);
5530 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg0);
5531 TREE_CONSTANT_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (arg0);
5533 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
5534 return TREE_OPERAND (arg0, 0);
5538 /* A + (-B) -> A - B */
5539 if (TREE_CODE (arg1) == NEGATE_EXPR)
5540 return fold (build (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5541 /* (-A) + B -> B - A */
5542 if (TREE_CODE (arg0) == NEGATE_EXPR)
5543 return fold (build (MINUS_EXPR, type, arg1, TREE_OPERAND (arg0, 0)));
5544 else if (! FLOAT_TYPE_P (type))
5546 if (integer_zerop (arg1))
5547 return non_lvalue (convert (type, arg0));
5549 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
5550 with a constant, and the two constants have no bits in common,
5551 we should treat this as a BIT_IOR_EXPR since this may produce more
5553 if (TREE_CODE (arg0) == BIT_AND_EXPR
5554 && TREE_CODE (arg1) == BIT_AND_EXPR
5555 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5556 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
5557 && integer_zerop (const_binop (BIT_AND_EXPR,
5558 TREE_OPERAND (arg0, 1),
5559 TREE_OPERAND (arg1, 1), 0)))
5561 code = BIT_IOR_EXPR;
5565 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
5566 (plus (plus (mult) (mult)) (foo)) so that we can
5567 take advantage of the factoring cases below. */
5568 if ((TREE_CODE (arg0) == PLUS_EXPR
5569 && TREE_CODE (arg1) == MULT_EXPR)
5570 || (TREE_CODE (arg1) == PLUS_EXPR
5571 && TREE_CODE (arg0) == MULT_EXPR))
5573 tree parg0, parg1, parg, marg;
5575 if (TREE_CODE (arg0) == PLUS_EXPR)
5576 parg = arg0, marg = arg1;
5578 parg = arg1, marg = arg0;
5579 parg0 = TREE_OPERAND (parg, 0);
5580 parg1 = TREE_OPERAND (parg, 1);
5584 if (TREE_CODE (parg0) == MULT_EXPR
5585 && TREE_CODE (parg1) != MULT_EXPR)
5586 return fold (build (PLUS_EXPR, type,
5587 fold (build (PLUS_EXPR, type,
5588 convert (type, parg0),
5589 convert (type, marg))),
5590 convert (type, parg1)));
5591 if (TREE_CODE (parg0) != MULT_EXPR
5592 && TREE_CODE (parg1) == MULT_EXPR)
5593 return fold (build (PLUS_EXPR, type,
5594 fold (build (PLUS_EXPR, type,
5595 convert (type, parg1),
5596 convert (type, marg))),
5597 convert (type, parg0)));
5600 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR)
5602 tree arg00, arg01, arg10, arg11;
5603 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
5605 /* (A * C) + (B * C) -> (A+B) * C.
5606 We are most concerned about the case where C is a constant,
5607 but other combinations show up during loop reduction. Since
5608 it is not difficult, try all four possibilities. */
5610 arg00 = TREE_OPERAND (arg0, 0);
5611 arg01 = TREE_OPERAND (arg0, 1);
5612 arg10 = TREE_OPERAND (arg1, 0);
5613 arg11 = TREE_OPERAND (arg1, 1);
5616 if (operand_equal_p (arg01, arg11, 0))
5617 same = arg01, alt0 = arg00, alt1 = arg10;
5618 else if (operand_equal_p (arg00, arg10, 0))
5619 same = arg00, alt0 = arg01, alt1 = arg11;
5620 else if (operand_equal_p (arg00, arg11, 0))
5621 same = arg00, alt0 = arg01, alt1 = arg10;
5622 else if (operand_equal_p (arg01, arg10, 0))
5623 same = arg01, alt0 = arg00, alt1 = arg11;
5625 /* No identical multiplicands; see if we can find a common
5626 power-of-two factor in non-power-of-two multiplies. This
5627 can help in multi-dimensional array access. */
5628 else if (TREE_CODE (arg01) == INTEGER_CST
5629 && TREE_CODE (arg11) == INTEGER_CST
5630 && TREE_INT_CST_HIGH (arg01) == 0
5631 && TREE_INT_CST_HIGH (arg11) == 0)
5633 HOST_WIDE_INT int01, int11, tmp;
5634 int01 = TREE_INT_CST_LOW (arg01);
5635 int11 = TREE_INT_CST_LOW (arg11);
5637 /* Move min of absolute values to int11. */
5638 if ((int01 >= 0 ? int01 : -int01)
5639 < (int11 >= 0 ? int11 : -int11))
5641 tmp = int01, int01 = int11, int11 = tmp;
5642 alt0 = arg00, arg00 = arg10, arg10 = alt0;
5643 alt0 = arg01, arg01 = arg11, arg11 = alt0;
5646 if (exact_log2 (int11) > 0 && int01 % int11 == 0)
5648 alt0 = fold (build (MULT_EXPR, type, arg00,
5649 build_int_2 (int01 / int11, 0)));
5656 return fold (build (MULT_EXPR, type,
5657 fold (build (PLUS_EXPR, type, alt0, alt1)),
5662 /* See if ARG1 is zero and X + ARG1 reduces to X. */
5663 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
5664 return non_lvalue (convert (type, arg0));
5666 /* Likewise if the operands are reversed. */
5667 else if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
5668 return non_lvalue (convert (type, arg1));
5671 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
5672 is a rotate of A by C1 bits. */
5673 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
5674 is a rotate of A by B bits. */
5676 enum tree_code code0, code1;
5677 code0 = TREE_CODE (arg0);
5678 code1 = TREE_CODE (arg1);
5679 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
5680 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
5681 && operand_equal_p (TREE_OPERAND (arg0, 0),
5682 TREE_OPERAND (arg1, 0), 0)
5683 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5685 tree tree01, tree11;
5686 enum tree_code code01, code11;
5688 tree01 = TREE_OPERAND (arg0, 1);
5689 tree11 = TREE_OPERAND (arg1, 1);
5690 STRIP_NOPS (tree01);
5691 STRIP_NOPS (tree11);
5692 code01 = TREE_CODE (tree01);
5693 code11 = TREE_CODE (tree11);
5694 if (code01 == INTEGER_CST
5695 && code11 == INTEGER_CST
5696 && TREE_INT_CST_HIGH (tree01) == 0
5697 && TREE_INT_CST_HIGH (tree11) == 0
5698 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
5699 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
5700 return build (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
5701 code0 == LSHIFT_EXPR ? tree01 : tree11);
5702 else if (code11 == MINUS_EXPR)
5704 tree tree110, tree111;
5705 tree110 = TREE_OPERAND (tree11, 0);
5706 tree111 = TREE_OPERAND (tree11, 1);
5707 STRIP_NOPS (tree110);
5708 STRIP_NOPS (tree111);
5709 if (TREE_CODE (tree110) == INTEGER_CST
5710 && 0 == compare_tree_int (tree110,
5712 (TREE_TYPE (TREE_OPERAND
5714 && operand_equal_p (tree01, tree111, 0))
5715 return build ((code0 == LSHIFT_EXPR
5718 type, TREE_OPERAND (arg0, 0), tree01);
5720 else if (code01 == MINUS_EXPR)
5722 tree tree010, tree011;
5723 tree010 = TREE_OPERAND (tree01, 0);
5724 tree011 = TREE_OPERAND (tree01, 1);
5725 STRIP_NOPS (tree010);
5726 STRIP_NOPS (tree011);
5727 if (TREE_CODE (tree010) == INTEGER_CST
5728 && 0 == compare_tree_int (tree010,
5730 (TREE_TYPE (TREE_OPERAND
5732 && operand_equal_p (tree11, tree011, 0))
5733 return build ((code0 != LSHIFT_EXPR
5736 type, TREE_OPERAND (arg0, 0), tree11);
5742 /* In most languages, can't associate operations on floats through
5743 parentheses. Rather than remember where the parentheses were, we
5744 don't associate floats at all. It shouldn't matter much. However,
5745 associating multiplications is only very slightly inaccurate, so do
5746 that if -funsafe-math-optimizations is specified. */
5749 && (! FLOAT_TYPE_P (type)
5750 || (flag_unsafe_math_optimizations && code == MULT_EXPR)))
5752 tree var0, con0, lit0, minus_lit0;
5753 tree var1, con1, lit1, minus_lit1;
5755 /* Split both trees into variables, constants, and literals. Then
5756 associate each group together, the constants with literals,
5757 then the result with variables. This increases the chances of
5758 literals being recombined later and of generating relocatable
5759 expressions for the sum of a constant and literal. */
5760 var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
5761 var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
5762 code == MINUS_EXPR);
5764 /* Only do something if we found more than two objects. Otherwise,
5765 nothing has changed and we risk infinite recursion. */
5766 if (2 < ((var0 != 0) + (var1 != 0)
5767 + (con0 != 0) + (con1 != 0)
5768 + (lit0 != 0) + (lit1 != 0)
5769 + (minus_lit0 != 0) + (minus_lit1 != 0)))
5771 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
5772 if (code == MINUS_EXPR)
5775 var0 = associate_trees (var0, var1, code, type);
5776 con0 = associate_trees (con0, con1, code, type);
5777 lit0 = associate_trees (lit0, lit1, code, type);
5778 minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
5780 /* Preserve the MINUS_EXPR if the negative part of the literal is
5781 greater than the positive part. Otherwise, the multiplicative
5782 folding code (i.e extract_muldiv) may be fooled in case
5783 unsigned constants are substracted, like in the following
5784 example: ((X*2 + 4) - 8U)/2. */
5785 if (minus_lit0 && lit0)
5787 if (tree_int_cst_lt (lit0, minus_lit0))
5789 minus_lit0 = associate_trees (minus_lit0, lit0,
5795 lit0 = associate_trees (lit0, minus_lit0,
5803 return convert (type, associate_trees (var0, minus_lit0,
5807 con0 = associate_trees (con0, minus_lit0,
5809 return convert (type, associate_trees (var0, con0,
5814 con0 = associate_trees (con0, lit0, code, type);
5815 return convert (type, associate_trees (var0, con0, code, type));
5821 t1 = const_binop (code, arg0, arg1, 0);
5822 if (t1 != NULL_TREE)
5824 /* The return value should always have
5825 the same type as the original expression. */
5826 if (TREE_TYPE (t1) != TREE_TYPE (t))
5827 t1 = convert (TREE_TYPE (t), t1);
5834 /* A - (-B) -> A + B */
5835 if (TREE_CODE (arg1) == NEGATE_EXPR)
5836 return fold (build (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5837 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
5838 if (TREE_CODE (arg0) == NEGATE_EXPR
5839 && (FLOAT_TYPE_P (type)
5840 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv))
5841 && negate_expr_p (arg1)
5842 && (! TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
5843 && (! TREE_SIDE_EFFECTS (arg1) || TREE_CONSTANT (arg0)))
5844 return fold (build (MINUS_EXPR, type, negate_expr (arg1),
5845 TREE_OPERAND (arg0, 0)));
5847 if (! FLOAT_TYPE_P (type))
5849 if (! wins && integer_zerop (arg0))
5850 return negate_expr (convert (type, arg1));
5851 if (integer_zerop (arg1))
5852 return non_lvalue (convert (type, arg0));
5854 /* (A * C) - (B * C) -> (A-B) * C. Since we are most concerned
5855 about the case where C is a constant, just try one of the
5856 four possibilities. */
5858 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR
5859 && operand_equal_p (TREE_OPERAND (arg0, 1),
5860 TREE_OPERAND (arg1, 1), 0))
5861 return fold (build (MULT_EXPR, type,
5862 fold (build (MINUS_EXPR, type,
5863 TREE_OPERAND (arg0, 0),
5864 TREE_OPERAND (arg1, 0))),
5865 TREE_OPERAND (arg0, 1)));
5867 /* Fold A - (A & B) into ~B & A. */
5868 if (!TREE_SIDE_EFFECTS (arg0)
5869 && TREE_CODE (arg1) == BIT_AND_EXPR)
5871 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
5872 return fold (build (BIT_AND_EXPR, type,
5873 fold (build1 (BIT_NOT_EXPR, type,
5874 TREE_OPERAND (arg1, 0))),
5876 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
5877 return fold (build (BIT_AND_EXPR, type,
5878 fold (build1 (BIT_NOT_EXPR, type,
5879 TREE_OPERAND (arg1, 1))),
5884 /* See if ARG1 is zero and X - ARG1 reduces to X. */
5885 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
5886 return non_lvalue (convert (type, arg0));
5888 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
5889 ARG0 is zero and X + ARG0 reduces to X, since that would mean
5890 (-ARG1 + ARG0) reduces to -ARG1. */
5891 else if (!wins && fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
5892 return negate_expr (convert (type, arg1));
5894 /* Fold &x - &x. This can happen from &x.foo - &x.
5895 This is unsafe for certain floats even in non-IEEE formats.
5896 In IEEE, it is unsafe because it does wrong for NaNs.
5897 Also note that operand_equal_p is always false if an operand
5900 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
5901 && operand_equal_p (arg0, arg1, 0))
5902 return convert (type, integer_zero_node);
5907 /* (-A) * (-B) -> A * B */
5908 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR)
5909 return fold (build (MULT_EXPR, type, TREE_OPERAND (arg0, 0),
5910 TREE_OPERAND (arg1, 0)));
5912 if (! FLOAT_TYPE_P (type))
5914 if (integer_zerop (arg1))
5915 return omit_one_operand (type, arg1, arg0);
5916 if (integer_onep (arg1))
5917 return non_lvalue (convert (type, arg0));
5919 /* (a * (1 << b)) is (a << b) */
5920 if (TREE_CODE (arg1) == LSHIFT_EXPR
5921 && integer_onep (TREE_OPERAND (arg1, 0)))
5922 return fold (build (LSHIFT_EXPR, type, arg0,
5923 TREE_OPERAND (arg1, 1)));
5924 if (TREE_CODE (arg0) == LSHIFT_EXPR
5925 && integer_onep (TREE_OPERAND (arg0, 0)))
5926 return fold (build (LSHIFT_EXPR, type, arg1,
5927 TREE_OPERAND (arg0, 1)));
5929 if (TREE_CODE (arg1) == INTEGER_CST
5930 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0),
5931 convert (type, arg1),
5933 return convert (type, tem);
5938 /* Maybe fold x * 0 to 0. The expressions aren't the same
5939 when x is NaN, since x * 0 is also NaN. Nor are they the
5940 same in modes with signed zeros, since multiplying a
5941 negative value by 0 gives -0, not +0. */
5942 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
5943 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
5944 && real_zerop (arg1))
5945 return omit_one_operand (type, arg1, arg0);
5946 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
5947 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
5948 && real_onep (arg1))
5949 return non_lvalue (convert (type, arg0));
5951 /* Transform x * -1.0 into -x. */
5952 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
5953 && real_minus_onep (arg1))
5954 return fold (build1 (NEGATE_EXPR, type, arg0));
5957 if (! wins && real_twop (arg1)
5958 && (*lang_hooks.decls.global_bindings_p) () == 0
5959 && ! CONTAINS_PLACEHOLDER_P (arg0))
5961 tree arg = save_expr (arg0);
5962 return fold (build (PLUS_EXPR, type, arg, arg));
5965 if (flag_unsafe_math_optimizations)
5967 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
5968 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
5970 /* Optimizations of sqrt(...)*sqrt(...). */
5971 if ((fcode0 == BUILT_IN_SQRT && fcode1 == BUILT_IN_SQRT)
5972 || (fcode0 == BUILT_IN_SQRTF && fcode1 == BUILT_IN_SQRTF)
5973 || (fcode0 == BUILT_IN_SQRTL && fcode1 == BUILT_IN_SQRTL))
5975 tree sqrtfn, arg, arglist;
5976 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
5977 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
5979 /* Optimize sqrt(x)*sqrt(x) as x. */
5980 if (operand_equal_p (arg00, arg10, 0)
5981 && ! HONOR_SNANS (TYPE_MODE (type)))
5984 /* Optimize sqrt(x)*sqrt(y) as sqrt(x*y). */
5985 sqrtfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
5986 arg = fold (build (MULT_EXPR, type, arg00, arg10));
5987 arglist = build_tree_list (NULL_TREE, arg);
5988 return build_function_call_expr (sqrtfn, arglist);
5991 /* Optimize exp(x)*exp(y) as exp(x+y). */
5992 if ((fcode0 == BUILT_IN_EXP && fcode1 == BUILT_IN_EXP)
5993 || (fcode0 == BUILT_IN_EXPF && fcode1 == BUILT_IN_EXPF)
5994 || (fcode0 == BUILT_IN_EXPL && fcode1 == BUILT_IN_EXPL))
5996 tree expfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
5997 tree arg = build (PLUS_EXPR, type,
5998 TREE_VALUE (TREE_OPERAND (arg0, 1)),
5999 TREE_VALUE (TREE_OPERAND (arg1, 1)));
6000 tree arglist = build_tree_list (NULL_TREE, fold (arg));
6001 return build_function_call_expr (expfn, arglist);
6004 /* Optimizations of pow(...)*pow(...). */
6005 if ((fcode0 == BUILT_IN_POW && fcode1 == BUILT_IN_POW)
6006 || (fcode0 == BUILT_IN_POWF && fcode1 == BUILT_IN_POWF)
6007 || (fcode0 == BUILT_IN_POWL && fcode1 == BUILT_IN_POWL))
6009 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
6010 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
6012 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
6013 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
6016 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
6017 if (operand_equal_p (arg01, arg11, 0))
6019 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
6020 tree arg = build (MULT_EXPR, type, arg00, arg10);
6021 tree arglist = tree_cons (NULL_TREE, fold (arg),
6022 build_tree_list (NULL_TREE,
6024 return build_function_call_expr (powfn, arglist);
6027 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
6028 if (operand_equal_p (arg00, arg10, 0))
6030 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
6031 tree arg = fold (build (PLUS_EXPR, type, arg01, arg11));
6032 tree arglist = tree_cons (NULL_TREE, arg00,
6033 build_tree_list (NULL_TREE,
6035 return build_function_call_expr (powfn, arglist);
6039 /* Optimize tan(x)*cos(x) as sin(x). */
6040 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_COS)
6041 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_COSF)
6042 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_COSL)
6043 || (fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_TAN)
6044 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_TANF)
6045 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_TANL))
6046 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
6047 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
6055 sinfn = implicit_built_in_decls[BUILT_IN_SIN];
6059 sinfn = implicit_built_in_decls[BUILT_IN_SINF];
6063 sinfn = implicit_built_in_decls[BUILT_IN_SINL];
6069 if (sinfn != NULL_TREE)
6070 return build_function_call_expr (sinfn,
6071 TREE_OPERAND (arg0, 1));
6079 if (integer_all_onesp (arg1))
6080 return omit_one_operand (type, arg1, arg0);
6081 if (integer_zerop (arg1))
6082 return non_lvalue (convert (type, arg0));
6083 t1 = distribute_bit_expr (code, type, arg0, arg1);
6084 if (t1 != NULL_TREE)
6087 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
6089 This results in more efficient code for machines without a NAND
6090 instruction. Combine will canonicalize to the first form
6091 which will allow use of NAND instructions provided by the
6092 backend if they exist. */
6093 if (TREE_CODE (arg0) == BIT_NOT_EXPR
6094 && TREE_CODE (arg1) == BIT_NOT_EXPR)
6096 return fold (build1 (BIT_NOT_EXPR, type,
6097 build (BIT_AND_EXPR, type,
6098 TREE_OPERAND (arg0, 0),
6099 TREE_OPERAND (arg1, 0))));
6102 /* See if this can be simplified into a rotate first. If that
6103 is unsuccessful continue in the association code. */
6107 if (integer_zerop (arg1))
6108 return non_lvalue (convert (type, arg0));
6109 if (integer_all_onesp (arg1))
6110 return fold (build1 (BIT_NOT_EXPR, type, arg0));
6112 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
6113 with a constant, and the two constants have no bits in common,
6114 we should treat this as a BIT_IOR_EXPR since this may produce more
6116 if (TREE_CODE (arg0) == BIT_AND_EXPR
6117 && TREE_CODE (arg1) == BIT_AND_EXPR
6118 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6119 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
6120 && integer_zerop (const_binop (BIT_AND_EXPR,
6121 TREE_OPERAND (arg0, 1),
6122 TREE_OPERAND (arg1, 1), 0)))
6124 code = BIT_IOR_EXPR;
6128 /* See if this can be simplified into a rotate first. If that
6129 is unsuccessful continue in the association code. */
6134 if (integer_all_onesp (arg1))
6135 return non_lvalue (convert (type, arg0));
6136 if (integer_zerop (arg1))
6137 return omit_one_operand (type, arg1, arg0);
6138 t1 = distribute_bit_expr (code, type, arg0, arg1);
6139 if (t1 != NULL_TREE)
6141 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
6142 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
6143 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
6146 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
6148 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
6149 && (~TREE_INT_CST_LOW (arg1)
6150 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
6151 return build1 (NOP_EXPR, type, TREE_OPERAND (arg0, 0));
6154 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
6156 This results in more efficient code for machines without a NOR
6157 instruction. Combine will canonicalize to the first form
6158 which will allow use of NOR instructions provided by the
6159 backend if they exist. */
6160 if (TREE_CODE (arg0) == BIT_NOT_EXPR
6161 && TREE_CODE (arg1) == BIT_NOT_EXPR)
6163 return fold (build1 (BIT_NOT_EXPR, type,
6164 build (BIT_IOR_EXPR, type,
6165 TREE_OPERAND (arg0, 0),
6166 TREE_OPERAND (arg1, 0))));
6171 case BIT_ANDTC_EXPR:
6172 if (integer_all_onesp (arg0))
6173 return non_lvalue (convert (type, arg1));
6174 if (integer_zerop (arg0))
6175 return omit_one_operand (type, arg0, arg1);
6176 if (TREE_CODE (arg1) == INTEGER_CST)
6178 arg1 = fold (build1 (BIT_NOT_EXPR, type, arg1));
6179 code = BIT_AND_EXPR;
6185 /* Don't touch a floating-point divide by zero unless the mode
6186 of the constant can represent infinity. */
6187 if (TREE_CODE (arg1) == REAL_CST
6188 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
6189 && real_zerop (arg1))
6192 /* (-A) / (-B) -> A / B */
6193 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR)
6194 return fold (build (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
6195 TREE_OPERAND (arg1, 0)));
6197 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
6198 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
6199 && real_onep (arg1))
6200 return non_lvalue (convert (type, arg0));
6202 /* If ARG1 is a constant, we can convert this to a multiply by the
6203 reciprocal. This does not have the same rounding properties,
6204 so only do this if -funsafe-math-optimizations. We can actually
6205 always safely do it if ARG1 is a power of two, but it's hard to
6206 tell if it is or not in a portable manner. */
6207 if (TREE_CODE (arg1) == REAL_CST)
6209 if (flag_unsafe_math_optimizations
6210 && 0 != (tem = const_binop (code, build_real (type, dconst1),
6212 return fold (build (MULT_EXPR, type, arg0, tem));
6213 /* Find the reciprocal if optimizing and the result is exact. */
6217 r = TREE_REAL_CST (arg1);
6218 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
6220 tem = build_real (type, r);
6221 return fold (build (MULT_EXPR, type, arg0, tem));
6225 /* Convert A/B/C to A/(B*C). */
6226 if (flag_unsafe_math_optimizations
6227 && TREE_CODE (arg0) == RDIV_EXPR)
6229 return fold (build (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
6230 build (MULT_EXPR, type, TREE_OPERAND (arg0, 1),
6233 /* Convert A/(B/C) to (A/B)*C. */
6234 if (flag_unsafe_math_optimizations
6235 && TREE_CODE (arg1) == RDIV_EXPR)
6237 return fold (build (MULT_EXPR, type,
6238 build (RDIV_EXPR, type, arg0,
6239 TREE_OPERAND (arg1, 0)),
6240 TREE_OPERAND (arg1, 1)));
6243 if (flag_unsafe_math_optimizations)
6245 enum built_in_function fcode = builtin_mathfn_code (arg1);
6246 /* Optimize x/exp(y) into x*exp(-y). */
6247 if (fcode == BUILT_IN_EXP
6248 || fcode == BUILT_IN_EXPF
6249 || fcode == BUILT_IN_EXPL)
6251 tree expfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
6252 tree arg = build1 (NEGATE_EXPR, type,
6253 TREE_VALUE (TREE_OPERAND (arg1, 1)));
6254 tree arglist = build_tree_list (NULL_TREE, fold (arg));
6255 arg1 = build_function_call_expr (expfn, arglist);
6256 return fold (build (MULT_EXPR, type, arg0, arg1));
6259 /* Optimize x/pow(y,z) into x*pow(y,-z). */
6260 if (fcode == BUILT_IN_POW
6261 || fcode == BUILT_IN_POWF
6262 || fcode == BUILT_IN_POWL)
6264 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
6265 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
6266 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1, 1)));
6267 tree neg11 = fold (build1 (NEGATE_EXPR, type, arg11));
6268 tree arglist = tree_cons(NULL_TREE, arg10,
6269 build_tree_list (NULL_TREE, neg11));
6270 arg1 = build_function_call_expr (powfn, arglist);
6271 return fold (build (MULT_EXPR, type, arg0, arg1));
6275 if (flag_unsafe_math_optimizations)
6277 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
6278 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
6280 /* Optimize sin(x)/cos(x) as tan(x). */
6281 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_COS)
6282 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_COSF)
6283 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_COSL))
6284 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
6285 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
6289 if (fcode0 == BUILT_IN_SIN)
6290 tanfn = implicit_built_in_decls[BUILT_IN_TAN];
6291 else if (fcode0 == BUILT_IN_SINF)
6292 tanfn = implicit_built_in_decls[BUILT_IN_TANF];
6293 else if (fcode0 == BUILT_IN_SINL)
6294 tanfn = implicit_built_in_decls[BUILT_IN_TANL];
6298 if (tanfn != NULL_TREE)
6299 return build_function_call_expr (tanfn,
6300 TREE_OPERAND (arg0, 1));
6303 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
6304 if (((fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_SIN)
6305 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_SINF)
6306 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_SINL))
6307 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
6308 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
6312 if (fcode0 == BUILT_IN_COS)
6313 tanfn = implicit_built_in_decls[BUILT_IN_TAN];
6314 else if (fcode0 == BUILT_IN_COSF)
6315 tanfn = implicit_built_in_decls[BUILT_IN_TANF];
6316 else if (fcode0 == BUILT_IN_COSL)
6317 tanfn = implicit_built_in_decls[BUILT_IN_TANL];
6321 if (tanfn != NULL_TREE)
6323 tree tmp = TREE_OPERAND (arg0, 1);
6324 tmp = build_function_call_expr (tanfn, tmp);
6325 return fold (build (RDIV_EXPR, type,
6326 build_real (type, dconst1),
6333 case TRUNC_DIV_EXPR:
6334 case ROUND_DIV_EXPR:
6335 case FLOOR_DIV_EXPR:
6337 case EXACT_DIV_EXPR:
6338 if (integer_onep (arg1))
6339 return non_lvalue (convert (type, arg0));
6340 if (integer_zerop (arg1))
6343 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
6344 operation, EXACT_DIV_EXPR.
6346 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
6347 At one time others generated faster code, it's not clear if they do
6348 after the last round to changes to the DIV code in expmed.c. */
6349 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
6350 && multiple_of_p (type, arg0, arg1))
6351 return fold (build (EXACT_DIV_EXPR, type, arg0, arg1));
6353 if (TREE_CODE (arg1) == INTEGER_CST
6354 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
6356 return convert (type, tem);
6361 case FLOOR_MOD_EXPR:
6362 case ROUND_MOD_EXPR:
6363 case TRUNC_MOD_EXPR:
6364 if (integer_onep (arg1))
6365 return omit_one_operand (type, integer_zero_node, arg0);
6366 if (integer_zerop (arg1))
6369 if (TREE_CODE (arg1) == INTEGER_CST
6370 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
6372 return convert (type, tem);
6378 if (integer_all_onesp (arg0))
6379 return omit_one_operand (type, arg0, arg1);
6383 /* Optimize -1 >> x for arithmetic right shifts. */
6384 if (integer_all_onesp (arg0) && ! TREE_UNSIGNED (type))
6385 return omit_one_operand (type, arg0, arg1);
6386 /* ... fall through ... */
6390 if (integer_zerop (arg1))
6391 return non_lvalue (convert (type, arg0));
6392 if (integer_zerop (arg0))
6393 return omit_one_operand (type, arg0, arg1);
6395 /* Since negative shift count is not well-defined,
6396 don't try to compute it in the compiler. */
6397 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
6399 /* Rewrite an LROTATE_EXPR by a constant into an
6400 RROTATE_EXPR by a new constant. */
6401 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
6403 TREE_SET_CODE (t, RROTATE_EXPR);
6404 code = RROTATE_EXPR;
6405 TREE_OPERAND (t, 1) = arg1
6408 convert (TREE_TYPE (arg1),
6409 build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type)), 0)),
6411 if (tree_int_cst_sgn (arg1) < 0)
6415 /* If we have a rotate of a bit operation with the rotate count and
6416 the second operand of the bit operation both constant,
6417 permute the two operations. */
6418 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
6419 && (TREE_CODE (arg0) == BIT_AND_EXPR
6420 || TREE_CODE (arg0) == BIT_ANDTC_EXPR
6421 || TREE_CODE (arg0) == BIT_IOR_EXPR
6422 || TREE_CODE (arg0) == BIT_XOR_EXPR)
6423 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
6424 return fold (build (TREE_CODE (arg0), type,
6425 fold (build (code, type,
6426 TREE_OPERAND (arg0, 0), arg1)),
6427 fold (build (code, type,
6428 TREE_OPERAND (arg0, 1), arg1))));
6430 /* Two consecutive rotates adding up to the width of the mode can
6432 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
6433 && TREE_CODE (arg0) == RROTATE_EXPR
6434 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6435 && TREE_INT_CST_HIGH (arg1) == 0
6436 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
6437 && ((TREE_INT_CST_LOW (arg1)
6438 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
6439 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type))))
6440 return TREE_OPERAND (arg0, 0);
6445 if (operand_equal_p (arg0, arg1, 0))
6446 return omit_one_operand (type, arg0, arg1);
6447 if (INTEGRAL_TYPE_P (type)
6448 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), 1))
6449 return omit_one_operand (type, arg1, arg0);
6453 if (operand_equal_p (arg0, arg1, 0))
6454 return omit_one_operand (type, arg0, arg1);
6455 if (INTEGRAL_TYPE_P (type)
6456 && TYPE_MAX_VALUE (type)
6457 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), 1))
6458 return omit_one_operand (type, arg1, arg0);
6461 case TRUTH_NOT_EXPR:
6462 /* Note that the operand of this must be an int
6463 and its values must be 0 or 1.
6464 ("true" is a fixed value perhaps depending on the language,
6465 but we don't handle values other than 1 correctly yet.) */
6466 tem = invert_truthvalue (arg0);
6467 /* Avoid infinite recursion. */
6468 if (TREE_CODE (tem) == TRUTH_NOT_EXPR)
6470 return convert (type, tem);
6472 case TRUTH_ANDIF_EXPR:
6473 /* Note that the operands of this must be ints
6474 and their values must be 0 or 1.
6475 ("true" is a fixed value perhaps depending on the language.) */
6476 /* If first arg is constant zero, return it. */
6477 if (integer_zerop (arg0))
6478 return convert (type, arg0);
6479 case TRUTH_AND_EXPR:
6480 /* If either arg is constant true, drop it. */
6481 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
6482 return non_lvalue (convert (type, arg1));
6483 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
6484 /* Preserve sequence points. */
6485 && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
6486 return non_lvalue (convert (type, arg0));
6487 /* If second arg is constant zero, result is zero, but first arg
6488 must be evaluated. */
6489 if (integer_zerop (arg1))
6490 return omit_one_operand (type, arg1, arg0);
6491 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
6492 case will be handled here. */
6493 if (integer_zerop (arg0))
6494 return omit_one_operand (type, arg0, arg1);
6497 /* We only do these simplifications if we are optimizing. */
6501 /* Check for things like (A || B) && (A || C). We can convert this
6502 to A || (B && C). Note that either operator can be any of the four
6503 truth and/or operations and the transformation will still be
6504 valid. Also note that we only care about order for the
6505 ANDIF and ORIF operators. If B contains side effects, this
6506 might change the truth-value of A. */
6507 if (TREE_CODE (arg0) == TREE_CODE (arg1)
6508 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
6509 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
6510 || TREE_CODE (arg0) == TRUTH_AND_EXPR
6511 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
6512 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
6514 tree a00 = TREE_OPERAND (arg0, 0);
6515 tree a01 = TREE_OPERAND (arg0, 1);
6516 tree a10 = TREE_OPERAND (arg1, 0);
6517 tree a11 = TREE_OPERAND (arg1, 1);
6518 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
6519 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
6520 && (code == TRUTH_AND_EXPR
6521 || code == TRUTH_OR_EXPR));
6523 if (operand_equal_p (a00, a10, 0))
6524 return fold (build (TREE_CODE (arg0), type, a00,
6525 fold (build (code, type, a01, a11))));
6526 else if (commutative && operand_equal_p (a00, a11, 0))
6527 return fold (build (TREE_CODE (arg0), type, a00,
6528 fold (build (code, type, a01, a10))));
6529 else if (commutative && operand_equal_p (a01, a10, 0))
6530 return fold (build (TREE_CODE (arg0), type, a01,
6531 fold (build (code, type, a00, a11))));
6533 /* This case if tricky because we must either have commutative
6534 operators or else A10 must not have side-effects. */
6536 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
6537 && operand_equal_p (a01, a11, 0))
6538 return fold (build (TREE_CODE (arg0), type,
6539 fold (build (code, type, a00, a10)),
6543 /* See if we can build a range comparison. */
6544 if (0 != (tem = fold_range_test (t)))
6547 /* Check for the possibility of merging component references. If our
6548 lhs is another similar operation, try to merge its rhs with our
6549 rhs. Then try to merge our lhs and rhs. */
6550 if (TREE_CODE (arg0) == code
6551 && 0 != (tem = fold_truthop (code, type,
6552 TREE_OPERAND (arg0, 1), arg1)))
6553 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6555 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
6560 case TRUTH_ORIF_EXPR:
6561 /* Note that the operands of this must be ints
6562 and their values must be 0 or true.
6563 ("true" is a fixed value perhaps depending on the language.) */
6564 /* If first arg is constant true, return it. */
6565 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
6566 return convert (type, arg0);
6568 /* If either arg is constant zero, drop it. */
6569 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
6570 return non_lvalue (convert (type, arg1));
6571 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
6572 /* Preserve sequence points. */
6573 && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
6574 return non_lvalue (convert (type, arg0));
6575 /* If second arg is constant true, result is true, but we must
6576 evaluate first arg. */
6577 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
6578 return omit_one_operand (type, arg1, arg0);
6579 /* Likewise for first arg, but note this only occurs here for
6581 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
6582 return omit_one_operand (type, arg0, arg1);
6585 case TRUTH_XOR_EXPR:
6586 /* If either arg is constant zero, drop it. */
6587 if (integer_zerop (arg0))
6588 return non_lvalue (convert (type, arg1));
6589 if (integer_zerop (arg1))
6590 return non_lvalue (convert (type, arg0));
6591 /* If either arg is constant true, this is a logical inversion. */
6592 if (integer_onep (arg0))
6593 return non_lvalue (convert (type, invert_truthvalue (arg1)));
6594 if (integer_onep (arg1))
6595 return non_lvalue (convert (type, invert_truthvalue (arg0)));
6604 /* If one arg is a real or integer constant, put it last. */
6605 if ((TREE_CODE (arg0) == INTEGER_CST
6606 && TREE_CODE (arg1) != INTEGER_CST)
6607 || (TREE_CODE (arg0) == REAL_CST
6608 && TREE_CODE (arg0) != REAL_CST))
6610 TREE_OPERAND (t, 0) = arg1;
6611 TREE_OPERAND (t, 1) = arg0;
6612 arg0 = TREE_OPERAND (t, 0);
6613 arg1 = TREE_OPERAND (t, 1);
6614 code = swap_tree_comparison (code);
6615 TREE_SET_CODE (t, code);
6618 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
6620 tree targ0 = strip_float_extensions (arg0);
6621 tree targ1 = strip_float_extensions (arg1);
6622 tree newtype = TREE_TYPE (targ0);
6624 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
6625 newtype = TREE_TYPE (targ1);
6627 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
6628 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
6629 return fold (build (code, type, convert (newtype, targ0),
6630 convert (newtype, targ1)));
6632 /* (-a) CMP (-b) -> b CMP a */
6633 if (TREE_CODE (arg0) == NEGATE_EXPR
6634 && TREE_CODE (arg1) == NEGATE_EXPR)
6635 return fold (build (code, type, TREE_OPERAND (arg1, 0),
6636 TREE_OPERAND (arg0, 0)));
6638 if (TREE_CODE (arg1) == REAL_CST)
6640 REAL_VALUE_TYPE cst;
6641 cst = TREE_REAL_CST (arg1);
6643 /* (-a) CMP CST -> a swap(CMP) (-CST) */
6644 if (TREE_CODE (arg0) == NEGATE_EXPR)
6646 fold (build (swap_tree_comparison (code), type,
6647 TREE_OPERAND (arg0, 0),
6648 build_real (TREE_TYPE (arg1),
6649 REAL_VALUE_NEGATE (cst))));
6651 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
6652 /* a CMP (-0) -> a CMP 0 */
6653 if (REAL_VALUE_MINUS_ZERO (cst))
6654 return fold (build (code, type, arg0,
6655 build_real (TREE_TYPE (arg1), dconst0)));
6657 /* x != NaN is always true, other ops are always false. */
6658 if (REAL_VALUE_ISNAN (cst)
6659 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))))
6661 t = (code == NE_EXPR) ? integer_one_node : integer_zero_node;
6662 return omit_one_operand (type, convert (type, t), arg0);
6665 /* Fold comparisons against infinity. */
6666 if (REAL_VALUE_ISINF (cst))
6668 tem = fold_inf_compare (code, type, arg0, arg1);
6669 if (tem != NULL_TREE)
6674 /* If this is a comparison of a real constant with a PLUS_EXPR
6675 or a MINUS_EXPR of a real constant, we can convert it into a
6676 comparison with a revised real constant as long as no overflow
6677 occurs when unsafe_math_optimizations are enabled. */
6678 if (flag_unsafe_math_optimizations
6679 && TREE_CODE (arg1) == REAL_CST
6680 && (TREE_CODE (arg0) == PLUS_EXPR
6681 || TREE_CODE (arg0) == MINUS_EXPR)
6682 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
6683 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
6684 ? MINUS_EXPR : PLUS_EXPR,
6685 arg1, TREE_OPERAND (arg0, 1), 0))
6686 && ! TREE_CONSTANT_OVERFLOW (tem))
6687 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6689 /* Likewise, we can simplify a comparison of a real constant with
6690 a MINUS_EXPR whose first operand is also a real constant, i.e.
6691 (c1 - x) < c2 becomes x > c1-c2. */
6692 if (flag_unsafe_math_optimizations
6693 && TREE_CODE (arg1) == REAL_CST
6694 && TREE_CODE (arg0) == MINUS_EXPR
6695 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST
6696 && 0 != (tem = const_binop (MINUS_EXPR, TREE_OPERAND (arg0, 0),
6698 && ! TREE_CONSTANT_OVERFLOW (tem))
6699 return fold (build (swap_tree_comparison (code), type,
6700 TREE_OPERAND (arg0, 1), tem));
6702 /* Fold comparisons against built-in math functions. */
6703 if (TREE_CODE (arg1) == REAL_CST
6704 && flag_unsafe_math_optimizations
6705 && ! flag_errno_math)
6707 enum built_in_function fcode = builtin_mathfn_code (arg0);
6709 if (fcode != END_BUILTINS)
6711 tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
6712 if (tem != NULL_TREE)
6718 /* Convert foo++ == CONST into ++foo == CONST + INCR.
6719 First, see if one arg is constant; find the constant arg
6720 and the other one. */
6722 tree constop = 0, varop = NULL_TREE;
6723 int constopnum = -1;
6725 if (TREE_CONSTANT (arg1))
6726 constopnum = 1, constop = arg1, varop = arg0;
6727 if (TREE_CONSTANT (arg0))
6728 constopnum = 0, constop = arg0, varop = arg1;
6730 if (constop && TREE_CODE (varop) == POSTINCREMENT_EXPR)
6732 /* This optimization is invalid for ordered comparisons
6733 if CONST+INCR overflows or if foo+incr might overflow.
6734 This optimization is invalid for floating point due to rounding.
6735 For pointer types we assume overflow doesn't happen. */
6736 if (POINTER_TYPE_P (TREE_TYPE (varop))
6737 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
6738 && (code == EQ_EXPR || code == NE_EXPR)))
6741 = fold (build (PLUS_EXPR, TREE_TYPE (varop),
6742 constop, TREE_OPERAND (varop, 1)));
6744 /* Do not overwrite the current varop to be a preincrement,
6745 create a new node so that we won't confuse our caller who
6746 might create trees and throw them away, reusing the
6747 arguments that they passed to build. This shows up in
6748 the THEN or ELSE parts of ?: being postincrements. */
6749 varop = build (PREINCREMENT_EXPR, TREE_TYPE (varop),
6750 TREE_OPERAND (varop, 0),
6751 TREE_OPERAND (varop, 1));
6753 /* If VAROP is a reference to a bitfield, we must mask
6754 the constant by the width of the field. */
6755 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
6756 && DECL_BIT_FIELD(TREE_OPERAND
6757 (TREE_OPERAND (varop, 0), 1)))
6760 = TREE_INT_CST_LOW (DECL_SIZE
6762 (TREE_OPERAND (varop, 0), 1)));
6763 tree mask, unsigned_type;
6764 unsigned int precision;
6765 tree folded_compare;
6767 /* First check whether the comparison would come out
6768 always the same. If we don't do that we would
6769 change the meaning with the masking. */
6770 if (constopnum == 0)
6771 folded_compare = fold (build (code, type, constop,
6772 TREE_OPERAND (varop, 0)));
6774 folded_compare = fold (build (code, type,
6775 TREE_OPERAND (varop, 0),
6777 if (integer_zerop (folded_compare)
6778 || integer_onep (folded_compare))
6779 return omit_one_operand (type, folded_compare, varop);
6781 unsigned_type = (*lang_hooks.types.type_for_size)(size, 1);
6782 precision = TYPE_PRECISION (unsigned_type);
6783 mask = build_int_2 (~0, ~0);
6784 TREE_TYPE (mask) = unsigned_type;
6785 force_fit_type (mask, 0);
6786 mask = const_binop (RSHIFT_EXPR, mask,
6787 size_int (precision - size), 0);
6788 newconst = fold (build (BIT_AND_EXPR,
6789 TREE_TYPE (varop), newconst,
6790 convert (TREE_TYPE (varop),
6794 t = build (code, type,
6795 (constopnum == 0) ? newconst : varop,
6796 (constopnum == 1) ? newconst : varop);
6800 else if (constop && TREE_CODE (varop) == POSTDECREMENT_EXPR)
6802 if (POINTER_TYPE_P (TREE_TYPE (varop))
6803 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
6804 && (code == EQ_EXPR || code == NE_EXPR)))
6807 = fold (build (MINUS_EXPR, TREE_TYPE (varop),
6808 constop, TREE_OPERAND (varop, 1)));
6810 /* Do not overwrite the current varop to be a predecrement,
6811 create a new node so that we won't confuse our caller who
6812 might create trees and throw them away, reusing the
6813 arguments that they passed to build. This shows up in
6814 the THEN or ELSE parts of ?: being postdecrements. */
6815 varop = build (PREDECREMENT_EXPR, TREE_TYPE (varop),
6816 TREE_OPERAND (varop, 0),
6817 TREE_OPERAND (varop, 1));
6819 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
6820 && DECL_BIT_FIELD(TREE_OPERAND
6821 (TREE_OPERAND (varop, 0), 1)))
6824 = TREE_INT_CST_LOW (DECL_SIZE
6826 (TREE_OPERAND (varop, 0), 1)));
6827 tree mask, unsigned_type;
6828 unsigned int precision;
6829 tree folded_compare;
6831 if (constopnum == 0)
6832 folded_compare = fold (build (code, type, constop,
6833 TREE_OPERAND (varop, 0)));
6835 folded_compare = fold (build (code, type,
6836 TREE_OPERAND (varop, 0),
6838 if (integer_zerop (folded_compare)
6839 || integer_onep (folded_compare))
6840 return omit_one_operand (type, folded_compare, varop);
6842 unsigned_type = (*lang_hooks.types.type_for_size)(size, 1);
6843 precision = TYPE_PRECISION (unsigned_type);
6844 mask = build_int_2 (~0, ~0);
6845 TREE_TYPE (mask) = TREE_TYPE (varop);
6846 force_fit_type (mask, 0);
6847 mask = const_binop (RSHIFT_EXPR, mask,
6848 size_int (precision - size), 0);
6849 newconst = fold (build (BIT_AND_EXPR,
6850 TREE_TYPE (varop), newconst,
6851 convert (TREE_TYPE (varop),
6855 t = build (code, type,
6856 (constopnum == 0) ? newconst : varop,
6857 (constopnum == 1) ? newconst : varop);
6863 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
6864 This transformation affects the cases which are handled in later
6865 optimizations involving comparisons with non-negative constants. */
6866 if (TREE_CODE (arg1) == INTEGER_CST
6867 && TREE_CODE (arg0) != INTEGER_CST
6868 && tree_int_cst_sgn (arg1) > 0)
6874 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6875 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6880 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6881 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6889 /* Comparisons with the highest or lowest possible integer of
6890 the specified size will have known values. */
6892 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1)));
6894 if (TREE_CODE (arg1) == INTEGER_CST
6895 && ! TREE_CONSTANT_OVERFLOW (arg1)
6896 && width <= HOST_BITS_PER_WIDE_INT
6897 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
6898 || POINTER_TYPE_P (TREE_TYPE (arg1))))
6900 unsigned HOST_WIDE_INT signed_max;
6901 unsigned HOST_WIDE_INT max, min;
6903 signed_max = ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1;
6905 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
6907 max = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
6913 min = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
6916 if (TREE_INT_CST_HIGH (arg1) == 0
6917 && TREE_INT_CST_LOW (arg1) == max)
6921 return omit_one_operand (type,
6922 convert (type, integer_zero_node),
6926 TREE_SET_CODE (t, EQ_EXPR);
6929 return omit_one_operand (type,
6930 convert (type, integer_one_node),
6934 TREE_SET_CODE (t, NE_EXPR);
6937 /* The GE_EXPR and LT_EXPR cases above are not normally
6938 reached because of previous transformations. */
6943 else if (TREE_INT_CST_HIGH (arg1) == 0
6944 && TREE_INT_CST_LOW (arg1) == max - 1)
6949 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
6950 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6954 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
6955 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6960 else if (TREE_INT_CST_HIGH (arg1) == (min ? -1 : 0)
6961 && TREE_INT_CST_LOW (arg1) == min)
6965 return omit_one_operand (type,
6966 convert (type, integer_zero_node),
6970 TREE_SET_CODE (t, EQ_EXPR);
6974 return omit_one_operand (type,
6975 convert (type, integer_one_node),
6979 TREE_SET_CODE (t, NE_EXPR);
6985 else if (TREE_INT_CST_HIGH (arg1) == (min ? -1 : 0)
6986 && TREE_INT_CST_LOW (arg1) == min + 1)
6991 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6992 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6996 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6997 t = build (code, type, TREE_OPERAND (t, 0), arg1);
7003 else if (TREE_INT_CST_HIGH (arg1) == 0
7004 && TREE_INT_CST_LOW (arg1) == signed_max
7005 && TREE_UNSIGNED (TREE_TYPE (arg1))
7006 /* signed_type does not work on pointer types. */
7007 && INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
7009 /* The following case also applies to X < signed_max+1
7010 and X >= signed_max+1 because previous transformations. */
7011 if (code == LE_EXPR || code == GT_EXPR)
7014 st0 = (*lang_hooks.types.signed_type) (TREE_TYPE (arg0));
7015 st1 = (*lang_hooks.types.signed_type) (TREE_TYPE (arg1));
7017 (build (code == LE_EXPR ? GE_EXPR: LT_EXPR,
7018 type, convert (st0, arg0),
7019 convert (st1, integer_zero_node)));
7025 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
7026 a MINUS_EXPR of a constant, we can convert it into a comparison with
7027 a revised constant as long as no overflow occurs. */
7028 if ((code == EQ_EXPR || code == NE_EXPR)
7029 && TREE_CODE (arg1) == INTEGER_CST
7030 && (TREE_CODE (arg0) == PLUS_EXPR
7031 || TREE_CODE (arg0) == MINUS_EXPR)
7032 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7033 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
7034 ? MINUS_EXPR : PLUS_EXPR,
7035 arg1, TREE_OPERAND (arg0, 1), 0))
7036 && ! TREE_CONSTANT_OVERFLOW (tem))
7037 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
7039 /* Similarly for a NEGATE_EXPR. */
7040 else if ((code == EQ_EXPR || code == NE_EXPR)
7041 && TREE_CODE (arg0) == NEGATE_EXPR
7042 && TREE_CODE (arg1) == INTEGER_CST
7043 && 0 != (tem = negate_expr (arg1))
7044 && TREE_CODE (tem) == INTEGER_CST
7045 && ! TREE_CONSTANT_OVERFLOW (tem))
7046 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
7048 /* If we have X - Y == 0, we can convert that to X == Y and similarly
7049 for !=. Don't do this for ordered comparisons due to overflow. */
7050 else if ((code == NE_EXPR || code == EQ_EXPR)
7051 && integer_zerop (arg1) && TREE_CODE (arg0) == MINUS_EXPR)
7052 return fold (build (code, type,
7053 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1)));
7055 /* If we are widening one operand of an integer comparison,
7056 see if the other operand is similarly being widened. Perhaps we
7057 can do the comparison in the narrower type. */
7058 else if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
7059 && TREE_CODE (arg0) == NOP_EXPR
7060 && (tem = get_unwidened (arg0, NULL_TREE)) != arg0
7061 && (t1 = get_unwidened (arg1, TREE_TYPE (tem))) != 0
7062 && (TREE_TYPE (t1) == TREE_TYPE (tem)
7063 || (TREE_CODE (t1) == INTEGER_CST
7064 && int_fits_type_p (t1, TREE_TYPE (tem)))))
7065 return fold (build (code, type, tem, convert (TREE_TYPE (tem), t1)));
7067 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
7068 constant, we can simplify it. */
7069 else if (TREE_CODE (arg1) == INTEGER_CST
7070 && (TREE_CODE (arg0) == MIN_EXPR
7071 || TREE_CODE (arg0) == MAX_EXPR)
7072 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
7073 return optimize_minmax_comparison (t);
7075 /* If we are comparing an ABS_EXPR with a constant, we can
7076 convert all the cases into explicit comparisons, but they may
7077 well not be faster than doing the ABS and one comparison.
7078 But ABS (X) <= C is a range comparison, which becomes a subtraction
7079 and a comparison, and is probably faster. */
7080 else if (code == LE_EXPR && TREE_CODE (arg1) == INTEGER_CST
7081 && TREE_CODE (arg0) == ABS_EXPR
7082 && ! TREE_SIDE_EFFECTS (arg0)
7083 && (0 != (tem = negate_expr (arg1)))
7084 && TREE_CODE (tem) == INTEGER_CST
7085 && ! TREE_CONSTANT_OVERFLOW (tem))
7086 return fold (build (TRUTH_ANDIF_EXPR, type,
7087 build (GE_EXPR, type, TREE_OPERAND (arg0, 0), tem),
7088 build (LE_EXPR, type,
7089 TREE_OPERAND (arg0, 0), arg1)));
7091 /* If this is an EQ or NE comparison with zero and ARG0 is
7092 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
7093 two operations, but the latter can be done in one less insn
7094 on machines that have only two-operand insns or on which a
7095 constant cannot be the first operand. */
7096 if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR)
7097 && TREE_CODE (arg0) == BIT_AND_EXPR)
7099 if (TREE_CODE (TREE_OPERAND (arg0, 0)) == LSHIFT_EXPR
7100 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 0), 0)))
7102 fold (build (code, type,
7103 build (BIT_AND_EXPR, TREE_TYPE (arg0),
7105 TREE_TYPE (TREE_OPERAND (arg0, 0)),
7106 TREE_OPERAND (arg0, 1),
7107 TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)),
7108 convert (TREE_TYPE (arg0),
7111 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
7112 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
7114 fold (build (code, type,
7115 build (BIT_AND_EXPR, TREE_TYPE (arg0),
7117 TREE_TYPE (TREE_OPERAND (arg0, 1)),
7118 TREE_OPERAND (arg0, 0),
7119 TREE_OPERAND (TREE_OPERAND (arg0, 1), 1)),
7120 convert (TREE_TYPE (arg0),
7125 /* If this is an NE or EQ comparison of zero against the result of a
7126 signed MOD operation whose second operand is a power of 2, make
7127 the MOD operation unsigned since it is simpler and equivalent. */
7128 if ((code == NE_EXPR || code == EQ_EXPR)
7129 && integer_zerop (arg1)
7130 && ! TREE_UNSIGNED (TREE_TYPE (arg0))
7131 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
7132 || TREE_CODE (arg0) == CEIL_MOD_EXPR
7133 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
7134 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
7135 && integer_pow2p (TREE_OPERAND (arg0, 1)))
7137 tree newtype = (*lang_hooks.types.unsigned_type) (TREE_TYPE (arg0));
7138 tree newmod = build (TREE_CODE (arg0), newtype,
7139 convert (newtype, TREE_OPERAND (arg0, 0)),
7140 convert (newtype, TREE_OPERAND (arg0, 1)));
7142 return build (code, type, newmod, convert (newtype, arg1));
7145 /* If this is an NE comparison of zero with an AND of one, remove the
7146 comparison since the AND will give the correct value. */
7147 if (code == NE_EXPR && integer_zerop (arg1)
7148 && TREE_CODE (arg0) == BIT_AND_EXPR
7149 && integer_onep (TREE_OPERAND (arg0, 1)))
7150 return convert (type, arg0);
7152 /* If we have (A & C) == C where C is a power of 2, convert this into
7153 (A & C) != 0. Similarly for NE_EXPR. */
7154 if ((code == EQ_EXPR || code == NE_EXPR)
7155 && TREE_CODE (arg0) == BIT_AND_EXPR
7156 && integer_pow2p (TREE_OPERAND (arg0, 1))
7157 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
7158 return fold (build (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
7159 arg0, integer_zero_node));
7161 /* If we have (A & C) != 0 where C is the sign bit of A, convert
7162 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
7163 if ((code == EQ_EXPR || code == NE_EXPR)
7164 && TREE_CODE (arg0) == BIT_AND_EXPR
7165 && integer_zerop (arg1))
7167 tree arg00 = sign_bit_p (TREE_OPERAND (arg0, 0),
7168 TREE_OPERAND (arg0, 1));
7169 if (arg00 != NULL_TREE)
7171 tree stype = (*lang_hooks.types.signed_type) (TREE_TYPE (arg00));
7172 return fold (build (code == EQ_EXPR ? GE_EXPR : LT_EXPR, type,
7173 convert (stype, arg00),
7174 convert (stype, integer_zero_node)));
7178 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
7179 and similarly for >= into !=. */
7180 if ((code == LT_EXPR || code == GE_EXPR)
7181 && TREE_UNSIGNED (TREE_TYPE (arg0))
7182 && TREE_CODE (arg1) == LSHIFT_EXPR
7183 && integer_onep (TREE_OPERAND (arg1, 0)))
7184 return build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
7185 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
7186 TREE_OPERAND (arg1, 1)),
7187 convert (TREE_TYPE (arg0), integer_zero_node));
7189 else if ((code == LT_EXPR || code == GE_EXPR)
7190 && TREE_UNSIGNED (TREE_TYPE (arg0))
7191 && (TREE_CODE (arg1) == NOP_EXPR
7192 || TREE_CODE (arg1) == CONVERT_EXPR)
7193 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
7194 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
7196 build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
7197 convert (TREE_TYPE (arg0),
7198 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
7199 TREE_OPERAND (TREE_OPERAND (arg1, 0), 1))),
7200 convert (TREE_TYPE (arg0), integer_zero_node));
7202 /* Simplify comparison of something with itself. (For IEEE
7203 floating-point, we can only do some of these simplifications.) */
7204 if (operand_equal_p (arg0, arg1, 0))
7211 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
7212 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
7213 return constant_boolean_node (1, type);
7215 TREE_SET_CODE (t, code);
7219 /* For NE, we can only do this simplification if integer
7220 or we don't honor IEEE floating point NaNs. */
7221 if (FLOAT_TYPE_P (TREE_TYPE (arg0))
7222 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
7224 /* ... fall through ... */
7227 return constant_boolean_node (0, type);
7233 /* If we are comparing an expression that just has comparisons
7234 of two integer values, arithmetic expressions of those comparisons,
7235 and constants, we can simplify it. There are only three cases
7236 to check: the two values can either be equal, the first can be
7237 greater, or the second can be greater. Fold the expression for
7238 those three values. Since each value must be 0 or 1, we have
7239 eight possibilities, each of which corresponds to the constant 0
7240 or 1 or one of the six possible comparisons.
7242 This handles common cases like (a > b) == 0 but also handles
7243 expressions like ((x > y) - (y > x)) > 0, which supposedly
7244 occur in macroized code. */
7246 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
7248 tree cval1 = 0, cval2 = 0;
7251 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
7252 /* Don't handle degenerate cases here; they should already
7253 have been handled anyway. */
7254 && cval1 != 0 && cval2 != 0
7255 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
7256 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
7257 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
7258 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
7259 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
7260 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
7261 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
7263 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
7264 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
7266 /* We can't just pass T to eval_subst in case cval1 or cval2
7267 was the same as ARG1. */
7270 = fold (build (code, type,
7271 eval_subst (arg0, cval1, maxval, cval2, minval),
7274 = fold (build (code, type,
7275 eval_subst (arg0, cval1, maxval, cval2, maxval),
7278 = fold (build (code, type,
7279 eval_subst (arg0, cval1, minval, cval2, maxval),
7282 /* All three of these results should be 0 or 1. Confirm they
7283 are. Then use those values to select the proper code
7286 if ((integer_zerop (high_result)
7287 || integer_onep (high_result))
7288 && (integer_zerop (equal_result)
7289 || integer_onep (equal_result))
7290 && (integer_zerop (low_result)
7291 || integer_onep (low_result)))
7293 /* Make a 3-bit mask with the high-order bit being the
7294 value for `>', the next for '=', and the low for '<'. */
7295 switch ((integer_onep (high_result) * 4)
7296 + (integer_onep (equal_result) * 2)
7297 + integer_onep (low_result))
7301 return omit_one_operand (type, integer_zero_node, arg0);
7322 return omit_one_operand (type, integer_one_node, arg0);
7325 t = build (code, type, cval1, cval2);
7327 return save_expr (t);
7334 /* If this is a comparison of a field, we may be able to simplify it. */
7335 if (((TREE_CODE (arg0) == COMPONENT_REF
7336 && (*lang_hooks.can_use_bit_fields_p) ())
7337 || TREE_CODE (arg0) == BIT_FIELD_REF)
7338 && (code == EQ_EXPR || code == NE_EXPR)
7339 /* Handle the constant case even without -O
7340 to make sure the warnings are given. */
7341 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
7343 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
7347 /* If this is a comparison of complex values and either or both sides
7348 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
7349 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
7350 This may prevent needless evaluations. */
7351 if ((code == EQ_EXPR || code == NE_EXPR)
7352 && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
7353 && (TREE_CODE (arg0) == COMPLEX_EXPR
7354 || TREE_CODE (arg1) == COMPLEX_EXPR
7355 || TREE_CODE (arg0) == COMPLEX_CST
7356 || TREE_CODE (arg1) == COMPLEX_CST))
7358 tree subtype = TREE_TYPE (TREE_TYPE (arg0));
7359 tree real0, imag0, real1, imag1;
7361 arg0 = save_expr (arg0);
7362 arg1 = save_expr (arg1);
7363 real0 = fold (build1 (REALPART_EXPR, subtype, arg0));
7364 imag0 = fold (build1 (IMAGPART_EXPR, subtype, arg0));
7365 real1 = fold (build1 (REALPART_EXPR, subtype, arg1));
7366 imag1 = fold (build1 (IMAGPART_EXPR, subtype, arg1));
7368 return fold (build ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR
7371 fold (build (code, type, real0, real1)),
7372 fold (build (code, type, imag0, imag1))));
7375 /* Optimize comparisons of strlen vs zero to a compare of the
7376 first character of the string vs zero. To wit,
7377 strlen(ptr) == 0 => *ptr == 0
7378 strlen(ptr) != 0 => *ptr != 0
7379 Other cases should reduce to one of these two (or a constant)
7380 due to the return value of strlen being unsigned. */
7381 if ((code == EQ_EXPR || code == NE_EXPR)
7382 && integer_zerop (arg1)
7383 && TREE_CODE (arg0) == CALL_EXPR
7384 && TREE_CODE (TREE_OPERAND (arg0, 0)) == ADDR_EXPR)
7386 tree fndecl = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7389 if (TREE_CODE (fndecl) == FUNCTION_DECL
7390 && DECL_BUILT_IN (fndecl)
7391 && DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_MD
7392 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
7393 && (arglist = TREE_OPERAND (arg0, 1))
7394 && TREE_CODE (TREE_TYPE (TREE_VALUE (arglist))) == POINTER_TYPE
7395 && ! TREE_CHAIN (arglist))
7396 return fold (build (code, type,
7397 build1 (INDIRECT_REF, char_type_node,
7398 TREE_VALUE(arglist)),
7399 integer_zero_node));
7402 /* From here on, the only cases we handle are when the result is
7403 known to be a constant.
7405 To compute GT, swap the arguments and do LT.
7406 To compute GE, do LT and invert the result.
7407 To compute LE, swap the arguments, do LT and invert the result.
7408 To compute NE, do EQ and invert the result.
7410 Therefore, the code below must handle only EQ and LT. */
7412 if (code == LE_EXPR || code == GT_EXPR)
7414 tem = arg0, arg0 = arg1, arg1 = tem;
7415 code = swap_tree_comparison (code);
7418 /* Note that it is safe to invert for real values here because we
7419 will check below in the one case that it matters. */
7423 if (code == NE_EXPR || code == GE_EXPR)
7426 code = invert_tree_comparison (code);
7429 /* Compute a result for LT or EQ if args permit;
7430 otherwise return T. */
7431 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
7433 if (code == EQ_EXPR)
7434 t1 = build_int_2 (tree_int_cst_equal (arg0, arg1), 0);
7436 t1 = build_int_2 ((TREE_UNSIGNED (TREE_TYPE (arg0))
7437 ? INT_CST_LT_UNSIGNED (arg0, arg1)
7438 : INT_CST_LT (arg0, arg1)),
7442 #if 0 /* This is no longer useful, but breaks some real code. */
7443 /* Assume a nonexplicit constant cannot equal an explicit one,
7444 since such code would be undefined anyway.
7445 Exception: on sysvr4, using #pragma weak,
7446 a label can come out as 0. */
7447 else if (TREE_CODE (arg1) == INTEGER_CST
7448 && !integer_zerop (arg1)
7449 && TREE_CONSTANT (arg0)
7450 && TREE_CODE (arg0) == ADDR_EXPR
7452 t1 = build_int_2 (0, 0);
7454 /* Two real constants can be compared explicitly. */
7455 else if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
7457 /* If either operand is a NaN, the result is false with two
7458 exceptions: First, an NE_EXPR is true on NaNs, but that case
7459 is already handled correctly since we will be inverting the
7460 result for NE_EXPR. Second, if we had inverted a LE_EXPR
7461 or a GE_EXPR into a LT_EXPR, we must return true so that it
7462 will be inverted into false. */
7464 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
7465 || REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
7466 t1 = build_int_2 (invert && code == LT_EXPR, 0);
7468 else if (code == EQ_EXPR)
7469 t1 = build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (arg0),
7470 TREE_REAL_CST (arg1)),
7473 t1 = build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (arg0),
7474 TREE_REAL_CST (arg1)),
7478 if (t1 == NULL_TREE)
7482 TREE_INT_CST_LOW (t1) ^= 1;
7484 TREE_TYPE (t1) = type;
7485 if (TREE_CODE (type) == BOOLEAN_TYPE)
7486 return (*lang_hooks.truthvalue_conversion) (t1);
7490 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
7491 so all simple results must be passed through pedantic_non_lvalue. */
7492 if (TREE_CODE (arg0) == INTEGER_CST)
7493 return pedantic_non_lvalue
7494 (TREE_OPERAND (t, (integer_zerop (arg0) ? 2 : 1)));
7495 else if (operand_equal_p (arg1, TREE_OPERAND (expr, 2), 0))
7496 return pedantic_omit_one_operand (type, arg1, arg0);
7498 /* If the second operand is zero, invert the comparison and swap
7499 the second and third operands. Likewise if the second operand
7500 is constant and the third is not or if the third operand is
7501 equivalent to the first operand of the comparison. */
7503 if (integer_zerop (arg1)
7504 || (TREE_CONSTANT (arg1) && ! TREE_CONSTANT (TREE_OPERAND (t, 2)))
7505 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
7506 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
7507 TREE_OPERAND (t, 2),
7508 TREE_OPERAND (arg0, 1))))
7510 /* See if this can be inverted. If it can't, possibly because
7511 it was a floating-point inequality comparison, don't do
7513 tem = invert_truthvalue (arg0);
7515 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
7517 t = build (code, type, tem,
7518 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
7520 /* arg1 should be the first argument of the new T. */
7521 arg1 = TREE_OPERAND (t, 1);
7526 /* If we have A op B ? A : C, we may be able to convert this to a
7527 simpler expression, depending on the operation and the values
7528 of B and C. Signed zeros prevent all of these transformations,
7529 for reasons given above each one. */
7531 if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
7532 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
7533 arg1, TREE_OPERAND (arg0, 1))
7534 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
7536 tree arg2 = TREE_OPERAND (t, 2);
7537 enum tree_code comp_code = TREE_CODE (arg0);
7541 /* If we have A op 0 ? A : -A, consider applying the following
7544 A == 0? A : -A same as -A
7545 A != 0? A : -A same as A
7546 A >= 0? A : -A same as abs (A)
7547 A > 0? A : -A same as abs (A)
7548 A <= 0? A : -A same as -abs (A)
7549 A < 0? A : -A same as -abs (A)
7551 None of these transformations work for modes with signed
7552 zeros. If A is +/-0, the first two transformations will
7553 change the sign of the result (from +0 to -0, or vice
7554 versa). The last four will fix the sign of the result,
7555 even though the original expressions could be positive or
7556 negative, depending on the sign of A.
7558 Note that all these transformations are correct if A is
7559 NaN, since the two alternatives (A and -A) are also NaNs. */
7560 if ((FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 1)))
7561 ? real_zerop (TREE_OPERAND (arg0, 1))
7562 : integer_zerop (TREE_OPERAND (arg0, 1)))
7563 && TREE_CODE (arg2) == NEGATE_EXPR
7564 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
7572 (convert (TREE_TYPE (TREE_OPERAND (t, 1)),
7575 return pedantic_non_lvalue (convert (type, arg1));
7578 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
7579 arg1 = convert ((*lang_hooks.types.signed_type)
7580 (TREE_TYPE (arg1)), arg1);
7581 return pedantic_non_lvalue
7582 (convert (type, fold (build1 (ABS_EXPR,
7583 TREE_TYPE (arg1), arg1))));
7586 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
7587 arg1 = convert ((lang_hooks.types.signed_type)
7588 (TREE_TYPE (arg1)), arg1);
7589 return pedantic_non_lvalue
7590 (negate_expr (convert (type,
7591 fold (build1 (ABS_EXPR,
7598 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
7599 A == 0 ? A : 0 is always 0 unless A is -0. Note that
7600 both transformations are correct when A is NaN: A != 0
7601 is then true, and A == 0 is false. */
7603 if (integer_zerop (TREE_OPERAND (arg0, 1)) && integer_zerop (arg2))
7605 if (comp_code == NE_EXPR)
7606 return pedantic_non_lvalue (convert (type, arg1));
7607 else if (comp_code == EQ_EXPR)
7608 return pedantic_non_lvalue (convert (type, integer_zero_node));
7611 /* Try some transformations of A op B ? A : B.
7613 A == B? A : B same as B
7614 A != B? A : B same as A
7615 A >= B? A : B same as max (A, B)
7616 A > B? A : B same as max (B, A)
7617 A <= B? A : B same as min (A, B)
7618 A < B? A : B same as min (B, A)
7620 As above, these transformations don't work in the presence
7621 of signed zeros. For example, if A and B are zeros of
7622 opposite sign, the first two transformations will change
7623 the sign of the result. In the last four, the original
7624 expressions give different results for (A=+0, B=-0) and
7625 (A=-0, B=+0), but the transformed expressions do not.
7627 The first two transformations are correct if either A or B
7628 is a NaN. In the first transformation, the condition will
7629 be false, and B will indeed be chosen. In the case of the
7630 second transformation, the condition A != B will be true,
7631 and A will be chosen.
7633 The conversions to max() and min() are not correct if B is
7634 a number and A is not. The conditions in the original
7635 expressions will be false, so all four give B. The min()
7636 and max() versions would give a NaN instead. */
7637 if (operand_equal_for_comparison_p (TREE_OPERAND (arg0, 1),
7638 arg2, TREE_OPERAND (arg0, 0)))
7640 tree comp_op0 = TREE_OPERAND (arg0, 0);
7641 tree comp_op1 = TREE_OPERAND (arg0, 1);
7642 tree comp_type = TREE_TYPE (comp_op0);
7644 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
7645 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
7655 return pedantic_non_lvalue (convert (type, arg2));
7657 return pedantic_non_lvalue (convert (type, arg1));
7660 /* In C++ a ?: expression can be an lvalue, so put the
7661 operand which will be used if they are equal first
7662 so that we can convert this back to the
7663 corresponding COND_EXPR. */
7664 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
7665 return pedantic_non_lvalue
7666 (convert (type, fold (build (MIN_EXPR, comp_type,
7667 (comp_code == LE_EXPR
7668 ? comp_op0 : comp_op1),
7669 (comp_code == LE_EXPR
7670 ? comp_op1 : comp_op0)))));
7674 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
7675 return pedantic_non_lvalue
7676 (convert (type, fold (build (MAX_EXPR, comp_type,
7677 (comp_code == GE_EXPR
7678 ? comp_op0 : comp_op1),
7679 (comp_code == GE_EXPR
7680 ? comp_op1 : comp_op0)))));
7687 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
7688 we might still be able to simplify this. For example,
7689 if C1 is one less or one more than C2, this might have started
7690 out as a MIN or MAX and been transformed by this function.
7691 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
7693 if (INTEGRAL_TYPE_P (type)
7694 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7695 && TREE_CODE (arg2) == INTEGER_CST)
7699 /* We can replace A with C1 in this case. */
7700 arg1 = convert (type, TREE_OPERAND (arg0, 1));
7701 t = build (code, type, TREE_OPERAND (t, 0), arg1,
7702 TREE_OPERAND (t, 2));
7706 /* If C1 is C2 + 1, this is min(A, C2). */
7707 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
7708 && operand_equal_p (TREE_OPERAND (arg0, 1),
7709 const_binop (PLUS_EXPR, arg2,
7710 integer_one_node, 0), 1))
7711 return pedantic_non_lvalue
7712 (fold (build (MIN_EXPR, type, arg1, arg2)));
7716 /* If C1 is C2 - 1, this is min(A, C2). */
7717 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
7718 && operand_equal_p (TREE_OPERAND (arg0, 1),
7719 const_binop (MINUS_EXPR, arg2,
7720 integer_one_node, 0), 1))
7721 return pedantic_non_lvalue
7722 (fold (build (MIN_EXPR, type, arg1, arg2)));
7726 /* If C1 is C2 - 1, this is max(A, C2). */
7727 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
7728 && operand_equal_p (TREE_OPERAND (arg0, 1),
7729 const_binop (MINUS_EXPR, arg2,
7730 integer_one_node, 0), 1))
7731 return pedantic_non_lvalue
7732 (fold (build (MAX_EXPR, type, arg1, arg2)));
7736 /* If C1 is C2 + 1, this is max(A, C2). */
7737 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
7738 && operand_equal_p (TREE_OPERAND (arg0, 1),
7739 const_binop (PLUS_EXPR, arg2,
7740 integer_one_node, 0), 1))
7741 return pedantic_non_lvalue
7742 (fold (build (MAX_EXPR, type, arg1, arg2)));
7751 /* If the second operand is simpler than the third, swap them
7752 since that produces better jump optimization results. */
7753 if ((TREE_CONSTANT (arg1) || DECL_P (arg1)
7754 || TREE_CODE (arg1) == SAVE_EXPR)
7755 && ! (TREE_CONSTANT (TREE_OPERAND (t, 2))
7756 || DECL_P (TREE_OPERAND (t, 2))
7757 || TREE_CODE (TREE_OPERAND (t, 2)) == SAVE_EXPR))
7759 /* See if this can be inverted. If it can't, possibly because
7760 it was a floating-point inequality comparison, don't do
7762 tem = invert_truthvalue (arg0);
7764 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
7766 t = build (code, type, tem,
7767 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
7769 /* arg1 should be the first argument of the new T. */
7770 arg1 = TREE_OPERAND (t, 1);
7775 /* Convert A ? 1 : 0 to simply A. */
7776 if (integer_onep (TREE_OPERAND (t, 1))
7777 && integer_zerop (TREE_OPERAND (t, 2))
7778 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
7779 call to fold will try to move the conversion inside
7780 a COND, which will recurse. In that case, the COND_EXPR
7781 is probably the best choice, so leave it alone. */
7782 && type == TREE_TYPE (arg0))
7783 return pedantic_non_lvalue (arg0);
7785 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
7786 over COND_EXPR in cases such as floating point comparisons. */
7787 if (integer_zerop (TREE_OPERAND (t, 1))
7788 && integer_onep (TREE_OPERAND (t, 2))
7789 && truth_value_p (TREE_CODE (arg0)))
7790 return pedantic_non_lvalue (convert (type,
7791 invert_truthvalue (arg0)));
7793 /* Look for expressions of the form A & 2 ? 2 : 0. The result of this
7794 operation is simply A & 2. */
7796 if (integer_zerop (TREE_OPERAND (t, 2))
7797 && TREE_CODE (arg0) == NE_EXPR
7798 && integer_zerop (TREE_OPERAND (arg0, 1))
7799 && integer_pow2p (arg1)
7800 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
7801 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
7803 return pedantic_non_lvalue (convert (type, TREE_OPERAND (arg0, 0)));
7805 /* Convert A ? B : 0 into A && B if A and B are truth values. */
7806 if (integer_zerop (TREE_OPERAND (t, 2))
7807 && truth_value_p (TREE_CODE (arg0))
7808 && truth_value_p (TREE_CODE (arg1)))
7809 return pedantic_non_lvalue (fold (build (TRUTH_ANDIF_EXPR, type,
7812 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
7813 if (integer_onep (TREE_OPERAND (t, 2))
7814 && truth_value_p (TREE_CODE (arg0))
7815 && truth_value_p (TREE_CODE (arg1)))
7817 /* Only perform transformation if ARG0 is easily inverted. */
7818 tem = invert_truthvalue (arg0);
7819 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
7820 return pedantic_non_lvalue (fold (build (TRUTH_ORIF_EXPR, type,
7827 /* When pedantic, a compound expression can be neither an lvalue
7828 nor an integer constant expression. */
7829 if (TREE_SIDE_EFFECTS (arg0) || pedantic)
7831 /* Don't let (0, 0) be null pointer constant. */
7832 if (integer_zerop (arg1))
7833 return build1 (NOP_EXPR, type, arg1);
7834 return convert (type, arg1);
7838 return build_complex (type, arg0, arg1);
7842 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7844 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
7845 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
7846 TREE_OPERAND (arg0, 1));
7847 else if (TREE_CODE (arg0) == COMPLEX_CST)
7848 return TREE_REALPART (arg0);
7849 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7850 return fold (build (TREE_CODE (arg0), type,
7851 fold (build1 (REALPART_EXPR, type,
7852 TREE_OPERAND (arg0, 0))),
7853 fold (build1 (REALPART_EXPR,
7854 type, TREE_OPERAND (arg0, 1)))));
7858 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7859 return convert (type, integer_zero_node);
7860 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
7861 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
7862 TREE_OPERAND (arg0, 0));
7863 else if (TREE_CODE (arg0) == COMPLEX_CST)
7864 return TREE_IMAGPART (arg0);
7865 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7866 return fold (build (TREE_CODE (arg0), type,
7867 fold (build1 (IMAGPART_EXPR, type,
7868 TREE_OPERAND (arg0, 0))),
7869 fold (build1 (IMAGPART_EXPR, type,
7870 TREE_OPERAND (arg0, 1)))));
7873 /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
7875 case CLEANUP_POINT_EXPR:
7876 if (! has_cleanups (arg0))
7877 return TREE_OPERAND (t, 0);
7880 enum tree_code code0 = TREE_CODE (arg0);
7881 int kind0 = TREE_CODE_CLASS (code0);
7882 tree arg00 = TREE_OPERAND (arg0, 0);
7885 if (kind0 == '1' || code0 == TRUTH_NOT_EXPR)
7886 return fold (build1 (code0, type,
7887 fold (build1 (CLEANUP_POINT_EXPR,
7888 TREE_TYPE (arg00), arg00))));
7890 if (kind0 == '<' || kind0 == '2'
7891 || code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR
7892 || code0 == TRUTH_AND_EXPR || code0 == TRUTH_OR_EXPR
7893 || code0 == TRUTH_XOR_EXPR)
7895 arg01 = TREE_OPERAND (arg0, 1);
7897 if (TREE_CONSTANT (arg00)
7898 || ((code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR)
7899 && ! has_cleanups (arg00)))
7900 return fold (build (code0, type, arg00,
7901 fold (build1 (CLEANUP_POINT_EXPR,
7902 TREE_TYPE (arg01), arg01))));
7904 if (TREE_CONSTANT (arg01))
7905 return fold (build (code0, type,
7906 fold (build1 (CLEANUP_POINT_EXPR,
7907 TREE_TYPE (arg00), arg00)),
7915 /* Check for a built-in function. */
7916 if (TREE_CODE (TREE_OPERAND (expr, 0)) == ADDR_EXPR
7917 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (expr, 0), 0))
7919 && DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (expr, 0), 0)))
7921 tree tmp = fold_builtin (expr);
7929 } /* switch (code) */
7932 /* Determine if first argument is a multiple of second argument. Return 0 if
7933 it is not, or we cannot easily determined it to be.
7935 An example of the sort of thing we care about (at this point; this routine
7936 could surely be made more general, and expanded to do what the *_DIV_EXPR's
7937 fold cases do now) is discovering that
7939 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7945 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
7947 This code also handles discovering that
7949 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7951 is a multiple of 8 so we don't have to worry about dealing with a
7954 Note that we *look* inside a SAVE_EXPR only to determine how it was
7955 calculated; it is not safe for fold to do much of anything else with the
7956 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
7957 at run time. For example, the latter example above *cannot* be implemented
7958 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
7959 evaluation time of the original SAVE_EXPR is not necessarily the same at
7960 the time the new expression is evaluated. The only optimization of this
7961 sort that would be valid is changing
7963 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
7967 SAVE_EXPR (I) * SAVE_EXPR (J)
7969 (where the same SAVE_EXPR (J) is used in the original and the
7970 transformed version). */
7973 multiple_of_p (type, top, bottom)
7978 if (operand_equal_p (top, bottom, 0))
7981 if (TREE_CODE (type) != INTEGER_TYPE)
7984 switch (TREE_CODE (top))
7987 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
7988 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
7992 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
7993 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
7996 if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
8000 op1 = TREE_OPERAND (top, 1);
8001 /* const_binop may not detect overflow correctly,
8002 so check for it explicitly here. */
8003 if (TYPE_PRECISION (TREE_TYPE (size_one_node))
8004 > TREE_INT_CST_LOW (op1)
8005 && TREE_INT_CST_HIGH (op1) == 0
8006 && 0 != (t1 = convert (type,
8007 const_binop (LSHIFT_EXPR, size_one_node,
8009 && ! TREE_OVERFLOW (t1))
8010 return multiple_of_p (type, t1, bottom);
8015 /* Can't handle conversions from non-integral or wider integral type. */
8016 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
8017 || (TYPE_PRECISION (type)
8018 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
8021 /* .. fall through ... */
8024 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
8027 if (TREE_CODE (bottom) != INTEGER_CST
8028 || (TREE_UNSIGNED (type)
8029 && (tree_int_cst_sgn (top) < 0
8030 || tree_int_cst_sgn (bottom) < 0)))
8032 return integer_zerop (const_binop (TRUNC_MOD_EXPR,
8040 /* Return true if `t' is known to be non-negative. */
8043 tree_expr_nonnegative_p (t)
8046 switch (TREE_CODE (t))
8056 /* These are undefined at zero. This is true even if
8057 C[LT]Z_DEFINED_VALUE_AT_ZERO is set, since what we're
8058 computing here is a user-visible property. */
8062 return tree_int_cst_sgn (t) >= 0;
8065 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
8068 if (FLOAT_TYPE_P (TREE_TYPE (t)))
8069 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8070 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8072 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
8073 both unsigned and at least 2 bits shorter than the result. */
8074 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
8075 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
8076 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
8078 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
8079 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
8080 if (TREE_CODE (inner1) == INTEGER_TYPE && TREE_UNSIGNED (inner1)
8081 && TREE_CODE (inner2) == INTEGER_TYPE && TREE_UNSIGNED (inner2))
8083 unsigned int prec = MAX (TYPE_PRECISION (inner1),
8084 TYPE_PRECISION (inner2)) + 1;
8085 return prec < TYPE_PRECISION (TREE_TYPE (t));
8091 if (FLOAT_TYPE_P (TREE_TYPE (t)))
8093 /* x * x for floating point x is always non-negative. */
8094 if (operand_equal_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1), 0))
8096 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8097 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8100 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
8101 both unsigned and their total bits is shorter than the result. */
8102 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
8103 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
8104 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
8106 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
8107 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
8108 if (TREE_CODE (inner1) == INTEGER_TYPE && TREE_UNSIGNED (inner1)
8109 && TREE_CODE (inner2) == INTEGER_TYPE && TREE_UNSIGNED (inner2))
8110 return TYPE_PRECISION (inner1) + TYPE_PRECISION (inner2)
8111 < TYPE_PRECISION (TREE_TYPE (t));
8115 case TRUNC_DIV_EXPR:
8117 case FLOOR_DIV_EXPR:
8118 case ROUND_DIV_EXPR:
8119 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8120 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8122 case TRUNC_MOD_EXPR:
8124 case FLOOR_MOD_EXPR:
8125 case ROUND_MOD_EXPR:
8126 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8129 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8130 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8134 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
8135 tree outer_type = TREE_TYPE (t);
8137 if (TREE_CODE (outer_type) == REAL_TYPE)
8139 if (TREE_CODE (inner_type) == REAL_TYPE)
8140 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8141 if (TREE_CODE (inner_type) == INTEGER_TYPE)
8143 if (TREE_UNSIGNED (inner_type))
8145 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8148 else if (TREE_CODE (outer_type) == INTEGER_TYPE)
8150 if (TREE_CODE (inner_type) == REAL_TYPE)
8151 return tree_expr_nonnegative_p (TREE_OPERAND (t,0));
8152 if (TREE_CODE (inner_type) == INTEGER_TYPE)
8153 return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
8154 && TREE_UNSIGNED (inner_type);
8160 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
8161 && tree_expr_nonnegative_p (TREE_OPERAND (t, 2));
8163 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8165 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8166 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8168 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8169 || tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8171 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8173 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8175 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8176 case NON_LVALUE_EXPR:
8177 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8179 return rtl_expr_nonnegative_p (RTL_EXPR_RTL (t));
8182 if (TREE_CODE (TREE_OPERAND (t, 0)) == ADDR_EXPR)
8184 tree fndecl = TREE_OPERAND (TREE_OPERAND (t, 0), 0);
8185 tree arglist = TREE_OPERAND (t, 1);
8186 if (TREE_CODE (fndecl) == FUNCTION_DECL
8187 && DECL_BUILT_IN (fndecl)
8188 && DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_MD)
8189 switch (DECL_FUNCTION_CODE (fndecl))
8192 case BUILT_IN_CABSL:
8193 case BUILT_IN_CABSF:
8198 case BUILT_IN_FABSF:
8199 case BUILT_IN_FABSL:
8201 case BUILT_IN_SQRTF:
8202 case BUILT_IN_SQRTL:
8206 case BUILT_IN_ATANF:
8207 case BUILT_IN_ATANL:
8209 case BUILT_IN_CEILF:
8210 case BUILT_IN_CEILL:
8211 case BUILT_IN_FLOOR:
8212 case BUILT_IN_FLOORF:
8213 case BUILT_IN_FLOORL:
8214 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
8219 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
8226 /* ... fall through ... */
8229 if (truth_value_p (TREE_CODE (t)))
8230 /* Truth values evaluate to 0 or 1, which is nonnegative. */
8234 /* We don't know sign of `t', so be conservative and return false. */
8238 /* Return true if `r' is known to be non-negative.
8239 Only handles constants at the moment. */
8242 rtl_expr_nonnegative_p (r)
8245 switch (GET_CODE (r))
8248 return INTVAL (r) >= 0;
8251 if (GET_MODE (r) == VOIDmode)
8252 return CONST_DOUBLE_HIGH (r) >= 0;
8260 units = CONST_VECTOR_NUNITS (r);
8262 for (i = 0; i < units; ++i)
8264 elt = CONST_VECTOR_ELT (r, i);
8265 if (!rtl_expr_nonnegative_p (elt))
8274 /* These are always nonnegative. */
8282 #include "gt-fold-const.h"