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 omit_one_operand PARAMS ((tree, tree, tree));
85 static tree pedantic_omit_one_operand PARAMS ((tree, tree, tree));
86 static tree distribute_bit_expr PARAMS ((enum tree_code, tree, tree, tree));
87 static tree make_bit_field_ref PARAMS ((tree, tree, int, int, int));
88 static tree optimize_bit_field_compare PARAMS ((enum tree_code, tree,
90 static tree decode_field_reference PARAMS ((tree, HOST_WIDE_INT *,
92 enum machine_mode *, int *,
93 int *, tree *, tree *));
94 static int all_ones_mask_p PARAMS ((tree, int));
95 static tree sign_bit_p PARAMS ((tree, tree));
96 static int simple_operand_p PARAMS ((tree));
97 static tree range_binop PARAMS ((enum tree_code, tree, tree, int,
99 static tree make_range PARAMS ((tree, int *, tree *, tree *));
100 static tree build_range_check PARAMS ((tree, tree, int, tree, tree));
101 static int merge_ranges PARAMS ((int *, tree *, tree *, int, tree, tree,
103 static tree fold_range_test PARAMS ((tree));
104 static tree unextend PARAMS ((tree, int, int, tree));
105 static tree fold_truthop PARAMS ((enum tree_code, tree, tree, tree));
106 static tree optimize_minmax_comparison PARAMS ((tree));
107 static tree extract_muldiv PARAMS ((tree, tree, enum tree_code, tree));
108 static tree extract_muldiv_1 PARAMS ((tree, tree, enum tree_code, tree));
109 static tree strip_compound_expr PARAMS ((tree, tree));
110 static int multiple_of_p PARAMS ((tree, tree, tree));
111 static tree constant_boolean_node PARAMS ((int, tree));
112 static int count_cond PARAMS ((tree, int));
113 static tree fold_binary_op_with_conditional_arg
114 PARAMS ((enum tree_code, tree, tree, tree, int));
115 static bool fold_real_zero_addition_p PARAMS ((tree, tree, int));
117 /* The following constants represent a bit based encoding of GCC's
118 comparison operators. This encoding simplifies transformations
119 on relational comparison operators, such as AND and OR. */
120 #define COMPCODE_FALSE 0
121 #define COMPCODE_LT 1
122 #define COMPCODE_EQ 2
123 #define COMPCODE_LE 3
124 #define COMPCODE_GT 4
125 #define COMPCODE_NE 5
126 #define COMPCODE_GE 6
127 #define COMPCODE_TRUE 7
129 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
130 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
131 and SUM1. Then this yields nonzero if overflow occurred during the
134 Overflow occurs if A and B have the same sign, but A and SUM differ in
135 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
137 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
139 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
140 We do that by representing the two-word integer in 4 words, with only
141 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
142 number. The value of the word is LOWPART + HIGHPART * BASE. */
145 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
146 #define HIGHPART(x) \
147 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
148 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
150 /* Unpack a two-word integer into 4 words.
151 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
152 WORDS points to the array of HOST_WIDE_INTs. */
155 encode (words, low, hi)
156 HOST_WIDE_INT *words;
157 unsigned HOST_WIDE_INT low;
160 words[0] = LOWPART (low);
161 words[1] = HIGHPART (low);
162 words[2] = LOWPART (hi);
163 words[3] = HIGHPART (hi);
166 /* Pack an array of 4 words into a two-word integer.
167 WORDS points to the array of words.
168 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
171 decode (words, low, hi)
172 HOST_WIDE_INT *words;
173 unsigned HOST_WIDE_INT *low;
176 *low = words[0] + words[1] * BASE;
177 *hi = words[2] + words[3] * BASE;
180 /* Make the integer constant T valid for its type by setting to 0 or 1 all
181 the bits in the constant that don't belong in the type.
183 Return 1 if a signed overflow occurs, 0 otherwise. If OVERFLOW is
184 nonzero, a signed overflow has already occurred in calculating T, so
188 force_fit_type (t, overflow)
192 unsigned HOST_WIDE_INT low;
196 if (TREE_CODE (t) == REAL_CST)
198 /* ??? Used to check for overflow here via CHECK_FLOAT_TYPE.
199 Consider doing it via real_convert now. */
203 else if (TREE_CODE (t) != INTEGER_CST)
206 low = TREE_INT_CST_LOW (t);
207 high = TREE_INT_CST_HIGH (t);
209 if (POINTER_TYPE_P (TREE_TYPE (t)))
212 prec = TYPE_PRECISION (TREE_TYPE (t));
214 /* First clear all bits that are beyond the type's precision. */
216 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
218 else if (prec > HOST_BITS_PER_WIDE_INT)
219 TREE_INT_CST_HIGH (t)
220 &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
223 TREE_INT_CST_HIGH (t) = 0;
224 if (prec < HOST_BITS_PER_WIDE_INT)
225 TREE_INT_CST_LOW (t) &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
228 /* Unsigned types do not suffer sign extension or overflow unless they
230 if (TREE_UNSIGNED (TREE_TYPE (t))
231 && ! (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
232 && TYPE_IS_SIZETYPE (TREE_TYPE (t))))
235 /* If the value's sign bit is set, extend the sign. */
236 if (prec != 2 * HOST_BITS_PER_WIDE_INT
237 && (prec > HOST_BITS_PER_WIDE_INT
238 ? 0 != (TREE_INT_CST_HIGH (t)
240 << (prec - HOST_BITS_PER_WIDE_INT - 1)))
241 : 0 != (TREE_INT_CST_LOW (t)
242 & ((unsigned HOST_WIDE_INT) 1 << (prec - 1)))))
244 /* Value is negative:
245 set to 1 all the bits that are outside this type's precision. */
246 if (prec > HOST_BITS_PER_WIDE_INT)
247 TREE_INT_CST_HIGH (t)
248 |= ((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
251 TREE_INT_CST_HIGH (t) = -1;
252 if (prec < HOST_BITS_PER_WIDE_INT)
253 TREE_INT_CST_LOW (t) |= ((unsigned HOST_WIDE_INT) (-1) << prec);
257 /* Return nonzero if signed overflow occurred. */
259 ((overflow | (low ^ TREE_INT_CST_LOW (t)) | (high ^ TREE_INT_CST_HIGH (t)))
263 /* Add two doubleword integers with doubleword result.
264 Each argument is given as two `HOST_WIDE_INT' pieces.
265 One argument is L1 and H1; the other, L2 and H2.
266 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
269 add_double (l1, h1, l2, h2, lv, hv)
270 unsigned HOST_WIDE_INT l1, l2;
271 HOST_WIDE_INT h1, h2;
272 unsigned HOST_WIDE_INT *lv;
275 unsigned HOST_WIDE_INT l;
279 h = h1 + h2 + (l < l1);
283 return OVERFLOW_SUM_SIGN (h1, h2, h);
286 /* Negate a doubleword integer with doubleword result.
287 Return nonzero if the operation overflows, assuming it's signed.
288 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
289 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
292 neg_double (l1, h1, lv, hv)
293 unsigned HOST_WIDE_INT l1;
295 unsigned HOST_WIDE_INT *lv;
302 return (*hv & h1) < 0;
312 /* Multiply two doubleword integers with doubleword result.
313 Return nonzero if the operation overflows, assuming it's signed.
314 Each argument is given as two `HOST_WIDE_INT' pieces.
315 One argument is L1 and H1; the other, L2 and H2.
316 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
319 mul_double (l1, h1, l2, h2, lv, hv)
320 unsigned HOST_WIDE_INT l1, l2;
321 HOST_WIDE_INT h1, h2;
322 unsigned HOST_WIDE_INT *lv;
325 HOST_WIDE_INT arg1[4];
326 HOST_WIDE_INT arg2[4];
327 HOST_WIDE_INT prod[4 * 2];
328 unsigned HOST_WIDE_INT carry;
330 unsigned HOST_WIDE_INT toplow, neglow;
331 HOST_WIDE_INT tophigh, neghigh;
333 encode (arg1, l1, h1);
334 encode (arg2, l2, h2);
336 memset ((char *) prod, 0, sizeof prod);
338 for (i = 0; i < 4; i++)
341 for (j = 0; j < 4; j++)
344 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
345 carry += arg1[i] * arg2[j];
346 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
348 prod[k] = LOWPART (carry);
349 carry = HIGHPART (carry);
354 decode (prod, lv, hv); /* This ignores prod[4] through prod[4*2-1] */
356 /* Check for overflow by calculating the top half of the answer in full;
357 it should agree with the low half's sign bit. */
358 decode (prod + 4, &toplow, &tophigh);
361 neg_double (l2, h2, &neglow, &neghigh);
362 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
366 neg_double (l1, h1, &neglow, &neghigh);
367 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
369 return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
372 /* Shift the doubleword integer in L1, H1 left by COUNT places
373 keeping only PREC bits of result.
374 Shift right if COUNT is negative.
375 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
376 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
379 lshift_double (l1, h1, count, prec, lv, hv, arith)
380 unsigned HOST_WIDE_INT l1;
381 HOST_WIDE_INT h1, count;
383 unsigned HOST_WIDE_INT *lv;
387 unsigned HOST_WIDE_INT signmask;
391 rshift_double (l1, h1, -count, prec, lv, hv, arith);
395 #ifdef SHIFT_COUNT_TRUNCATED
396 if (SHIFT_COUNT_TRUNCATED)
400 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
402 /* Shifting by the host word size is undefined according to the
403 ANSI standard, so we must handle this as a special case. */
407 else if (count >= HOST_BITS_PER_WIDE_INT)
409 *hv = l1 << (count - HOST_BITS_PER_WIDE_INT);
414 *hv = (((unsigned HOST_WIDE_INT) h1 << count)
415 | (l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
419 /* Sign extend all bits that are beyond the precision. */
421 signmask = -((prec > HOST_BITS_PER_WIDE_INT
422 ? ((unsigned HOST_WIDE_INT) *hv
423 >> (prec - HOST_BITS_PER_WIDE_INT - 1))
424 : (*lv >> (prec - 1))) & 1);
426 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
428 else if (prec >= HOST_BITS_PER_WIDE_INT)
430 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
431 *hv |= signmask << (prec - HOST_BITS_PER_WIDE_INT);
436 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
437 *lv |= signmask << prec;
441 /* Shift the doubleword integer in L1, H1 right by COUNT places
442 keeping only PREC bits of result. COUNT must be positive.
443 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
444 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
447 rshift_double (l1, h1, count, prec, lv, hv, arith)
448 unsigned HOST_WIDE_INT l1;
449 HOST_WIDE_INT h1, count;
451 unsigned HOST_WIDE_INT *lv;
455 unsigned HOST_WIDE_INT signmask;
458 ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
461 #ifdef SHIFT_COUNT_TRUNCATED
462 if (SHIFT_COUNT_TRUNCATED)
466 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
468 /* Shifting by the host word size is undefined according to the
469 ANSI standard, so we must handle this as a special case. */
473 else if (count >= HOST_BITS_PER_WIDE_INT)
476 *lv = (unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT);
480 *hv = (unsigned HOST_WIDE_INT) h1 >> count;
482 | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
485 /* Zero / sign extend all bits that are beyond the precision. */
487 if (count >= (HOST_WIDE_INT)prec)
492 else if ((prec - count) >= 2 * HOST_BITS_PER_WIDE_INT)
494 else if ((prec - count) >= HOST_BITS_PER_WIDE_INT)
496 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - count - HOST_BITS_PER_WIDE_INT));
497 *hv |= signmask << (prec - count - HOST_BITS_PER_WIDE_INT);
502 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << (prec - count));
503 *lv |= signmask << (prec - count);
507 /* Rotate the doubleword integer in L1, H1 left by COUNT places
508 keeping only PREC bits of result.
509 Rotate right if COUNT is negative.
510 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
513 lrotate_double (l1, h1, count, prec, lv, hv)
514 unsigned HOST_WIDE_INT l1;
515 HOST_WIDE_INT h1, count;
517 unsigned HOST_WIDE_INT *lv;
520 unsigned HOST_WIDE_INT s1l, s2l;
521 HOST_WIDE_INT s1h, s2h;
527 lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
528 rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
533 /* Rotate the doubleword integer in L1, H1 left by COUNT places
534 keeping only PREC bits of result. COUNT must be positive.
535 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
538 rrotate_double (l1, h1, count, prec, lv, hv)
539 unsigned HOST_WIDE_INT l1;
540 HOST_WIDE_INT h1, count;
542 unsigned HOST_WIDE_INT *lv;
545 unsigned HOST_WIDE_INT s1l, s2l;
546 HOST_WIDE_INT s1h, s2h;
552 rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
553 lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
558 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
559 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
560 CODE is a tree code for a kind of division, one of
561 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
563 It controls how the quotient is rounded to an integer.
564 Return nonzero if the operation overflows.
565 UNS nonzero says do unsigned division. */
568 div_and_round_double (code, uns,
569 lnum_orig, hnum_orig, lden_orig, hden_orig,
570 lquo, hquo, lrem, hrem)
573 unsigned HOST_WIDE_INT lnum_orig; /* num == numerator == dividend */
574 HOST_WIDE_INT hnum_orig;
575 unsigned HOST_WIDE_INT lden_orig; /* den == denominator == divisor */
576 HOST_WIDE_INT hden_orig;
577 unsigned HOST_WIDE_INT *lquo, *lrem;
578 HOST_WIDE_INT *hquo, *hrem;
581 HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
582 HOST_WIDE_INT den[4], quo[4];
584 unsigned HOST_WIDE_INT work;
585 unsigned HOST_WIDE_INT carry = 0;
586 unsigned HOST_WIDE_INT lnum = lnum_orig;
587 HOST_WIDE_INT hnum = hnum_orig;
588 unsigned HOST_WIDE_INT lden = lden_orig;
589 HOST_WIDE_INT hden = hden_orig;
592 if (hden == 0 && lden == 0)
593 overflow = 1, lden = 1;
595 /* calculate quotient sign and convert operands to unsigned. */
601 /* (minimum integer) / (-1) is the only overflow case. */
602 if (neg_double (lnum, hnum, &lnum, &hnum)
603 && ((HOST_WIDE_INT) lden & hden) == -1)
609 neg_double (lden, hden, &lden, &hden);
613 if (hnum == 0 && hden == 0)
614 { /* single precision */
616 /* This unsigned division rounds toward zero. */
622 { /* trivial case: dividend < divisor */
623 /* hden != 0 already checked. */
630 memset ((char *) quo, 0, sizeof quo);
632 memset ((char *) num, 0, sizeof num); /* to zero 9th element */
633 memset ((char *) den, 0, sizeof den);
635 encode (num, lnum, hnum);
636 encode (den, lden, hden);
638 /* Special code for when the divisor < BASE. */
639 if (hden == 0 && lden < (unsigned HOST_WIDE_INT) BASE)
641 /* hnum != 0 already checked. */
642 for (i = 4 - 1; i >= 0; i--)
644 work = num[i] + carry * BASE;
645 quo[i] = work / lden;
651 /* Full double precision division,
652 with thanks to Don Knuth's "Seminumerical Algorithms". */
653 int num_hi_sig, den_hi_sig;
654 unsigned HOST_WIDE_INT quo_est, scale;
656 /* Find the highest nonzero divisor digit. */
657 for (i = 4 - 1;; i--)
664 /* Insure that the first digit of the divisor is at least BASE/2.
665 This is required by the quotient digit estimation algorithm. */
667 scale = BASE / (den[den_hi_sig] + 1);
669 { /* scale divisor and dividend */
671 for (i = 0; i <= 4 - 1; i++)
673 work = (num[i] * scale) + carry;
674 num[i] = LOWPART (work);
675 carry = HIGHPART (work);
680 for (i = 0; i <= 4 - 1; i++)
682 work = (den[i] * scale) + carry;
683 den[i] = LOWPART (work);
684 carry = HIGHPART (work);
685 if (den[i] != 0) den_hi_sig = i;
692 for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--)
694 /* Guess the next quotient digit, quo_est, by dividing the first
695 two remaining dividend digits by the high order quotient digit.
696 quo_est is never low and is at most 2 high. */
697 unsigned HOST_WIDE_INT tmp;
699 num_hi_sig = i + den_hi_sig + 1;
700 work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
701 if (num[num_hi_sig] != den[den_hi_sig])
702 quo_est = work / den[den_hi_sig];
706 /* Refine quo_est so it's usually correct, and at most one high. */
707 tmp = work - quo_est * den[den_hi_sig];
709 && (den[den_hi_sig - 1] * quo_est
710 > (tmp * BASE + num[num_hi_sig - 2])))
713 /* Try QUO_EST as the quotient digit, by multiplying the
714 divisor by QUO_EST and subtracting from the remaining dividend.
715 Keep in mind that QUO_EST is the I - 1st digit. */
718 for (j = 0; j <= den_hi_sig; j++)
720 work = quo_est * den[j] + carry;
721 carry = HIGHPART (work);
722 work = num[i + j] - LOWPART (work);
723 num[i + j] = LOWPART (work);
724 carry += HIGHPART (work) != 0;
727 /* If quo_est was high by one, then num[i] went negative and
728 we need to correct things. */
729 if (num[num_hi_sig] < (HOST_WIDE_INT) carry)
732 carry = 0; /* add divisor back in */
733 for (j = 0; j <= den_hi_sig; j++)
735 work = num[i + j] + den[j] + carry;
736 carry = HIGHPART (work);
737 num[i + j] = LOWPART (work);
740 num [num_hi_sig] += carry;
743 /* Store the quotient digit. */
748 decode (quo, lquo, hquo);
751 /* if result is negative, make it so. */
753 neg_double (*lquo, *hquo, lquo, hquo);
755 /* compute trial remainder: rem = num - (quo * den) */
756 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
757 neg_double (*lrem, *hrem, lrem, hrem);
758 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
763 case TRUNC_MOD_EXPR: /* round toward zero */
764 case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
768 case FLOOR_MOD_EXPR: /* round toward negative infinity */
769 if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
772 add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
780 case CEIL_MOD_EXPR: /* round toward positive infinity */
781 if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
783 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
791 case ROUND_MOD_EXPR: /* round to closest integer */
793 unsigned HOST_WIDE_INT labs_rem = *lrem;
794 HOST_WIDE_INT habs_rem = *hrem;
795 unsigned HOST_WIDE_INT labs_den = lden, ltwice;
796 HOST_WIDE_INT habs_den = hden, htwice;
798 /* Get absolute values */
800 neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
802 neg_double (lden, hden, &labs_den, &habs_den);
804 /* If (2 * abs (lrem) >= abs (lden)) */
805 mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
806 labs_rem, habs_rem, <wice, &htwice);
808 if (((unsigned HOST_WIDE_INT) habs_den
809 < (unsigned HOST_WIDE_INT) htwice)
810 || (((unsigned HOST_WIDE_INT) habs_den
811 == (unsigned HOST_WIDE_INT) htwice)
812 && (labs_den < ltwice)))
816 add_double (*lquo, *hquo,
817 (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
820 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
832 /* compute true remainder: rem = num - (quo * den) */
833 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
834 neg_double (*lrem, *hrem, lrem, hrem);
835 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
839 /* Determine whether an expression T can be cheaply negated using
840 the function negate_expr. */
846 unsigned HOST_WIDE_INT val;
853 type = TREE_TYPE (t);
856 switch (TREE_CODE (t))
859 if (TREE_UNSIGNED (type))
862 /* Check that -CST will not overflow type. */
863 prec = TYPE_PRECISION (type);
864 if (prec > HOST_BITS_PER_WIDE_INT)
866 if (TREE_INT_CST_LOW (t) != 0)
868 prec -= HOST_BITS_PER_WIDE_INT;
869 val = TREE_INT_CST_HIGH (t);
872 val = TREE_INT_CST_LOW (t);
873 if (prec < HOST_BITS_PER_WIDE_INT)
874 val &= ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
875 return val != ((unsigned HOST_WIDE_INT) 1 << (prec - 1));
888 /* Given T, an expression, return the negation of T. Allow for T to be
889 null, in which case return null. */
901 type = TREE_TYPE (t);
904 switch (TREE_CODE (t))
908 if (! TREE_UNSIGNED (type)
909 && 0 != (tem = fold (build1 (NEGATE_EXPR, type, t)))
910 && ! TREE_OVERFLOW (tem))
915 return convert (type, TREE_OPERAND (t, 0));
918 /* - (A - B) -> B - A */
919 if (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
920 return convert (type,
921 fold (build (MINUS_EXPR, TREE_TYPE (t),
923 TREE_OPERAND (t, 0))));
930 return convert (type, fold (build1 (NEGATE_EXPR, TREE_TYPE (t), t)));
933 /* Split a tree IN into a constant, literal and variable parts that could be
934 combined with CODE to make IN. "constant" means an expression with
935 TREE_CONSTANT but that isn't an actual constant. CODE must be a
936 commutative arithmetic operation. Store the constant part into *CONP,
937 the literal in *LITP and return the variable part. If a part isn't
938 present, set it to null. If the tree does not decompose in this way,
939 return the entire tree as the variable part and the other parts as null.
941 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
942 case, we negate an operand that was subtracted. Except if it is a
943 literal for which we use *MINUS_LITP instead.
945 If NEGATE_P is true, we are negating all of IN, again except a literal
946 for which we use *MINUS_LITP instead.
948 If IN is itself a literal or constant, return it as appropriate.
950 Note that we do not guarantee that any of the three values will be the
951 same type as IN, but they will have the same signedness and mode. */
954 split_tree (in, code, conp, litp, minus_litp, negate_p)
957 tree *conp, *litp, *minus_litp;
966 /* Strip any conversions that don't change the machine mode or signedness. */
967 STRIP_SIGN_NOPS (in);
969 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST)
971 else if (TREE_CODE (in) == code
972 || (! FLOAT_TYPE_P (TREE_TYPE (in))
973 /* We can associate addition and subtraction together (even
974 though the C standard doesn't say so) for integers because
975 the value is not affected. For reals, the value might be
976 affected, so we can't. */
977 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
978 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
980 tree op0 = TREE_OPERAND (in, 0);
981 tree op1 = TREE_OPERAND (in, 1);
982 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
983 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
985 /* First see if either of the operands is a literal, then a constant. */
986 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
987 *litp = op0, op0 = 0;
988 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST)
989 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
991 if (op0 != 0 && TREE_CONSTANT (op0))
992 *conp = op0, op0 = 0;
993 else if (op1 != 0 && TREE_CONSTANT (op1))
994 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
996 /* If we haven't dealt with either operand, this is not a case we can
997 decompose. Otherwise, VAR is either of the ones remaining, if any. */
998 if (op0 != 0 && op1 != 0)
1003 var = op1, neg_var_p = neg1_p;
1005 /* Now do any needed negations. */
1007 *minus_litp = *litp, *litp = 0;
1009 *conp = negate_expr (*conp);
1011 var = negate_expr (var);
1013 else if (TREE_CONSTANT (in))
1021 *minus_litp = *litp, *litp = 0;
1022 else if (*minus_litp)
1023 *litp = *minus_litp, *minus_litp = 0;
1024 *conp = negate_expr (*conp);
1025 var = negate_expr (var);
1031 /* Re-associate trees split by the above function. T1 and T2 are either
1032 expressions to associate or null. Return the new expression, if any. If
1033 we build an operation, do it in TYPE and with CODE. */
1036 associate_trees (t1, t2, code, type)
1038 enum tree_code code;
1046 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1047 try to fold this since we will have infinite recursion. But do
1048 deal with any NEGATE_EXPRs. */
1049 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
1050 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1052 if (code == PLUS_EXPR)
1054 if (TREE_CODE (t1) == NEGATE_EXPR)
1055 return build (MINUS_EXPR, type, convert (type, t2),
1056 convert (type, TREE_OPERAND (t1, 0)));
1057 else if (TREE_CODE (t2) == NEGATE_EXPR)
1058 return build (MINUS_EXPR, type, convert (type, t1),
1059 convert (type, TREE_OPERAND (t2, 0)));
1061 return build (code, type, convert (type, t1), convert (type, t2));
1064 return fold (build (code, type, convert (type, t1), convert (type, t2)));
1067 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1068 to produce a new constant.
1070 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1073 int_const_binop (code, arg1, arg2, notrunc)
1074 enum tree_code code;
1078 unsigned HOST_WIDE_INT int1l, int2l;
1079 HOST_WIDE_INT int1h, int2h;
1080 unsigned HOST_WIDE_INT low;
1082 unsigned HOST_WIDE_INT garbagel;
1083 HOST_WIDE_INT garbageh;
1085 tree type = TREE_TYPE (arg1);
1086 int uns = TREE_UNSIGNED (type);
1088 = (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type));
1090 int no_overflow = 0;
1092 int1l = TREE_INT_CST_LOW (arg1);
1093 int1h = TREE_INT_CST_HIGH (arg1);
1094 int2l = TREE_INT_CST_LOW (arg2);
1095 int2h = TREE_INT_CST_HIGH (arg2);
1100 low = int1l | int2l, hi = int1h | int2h;
1104 low = int1l ^ int2l, hi = int1h ^ int2h;
1108 low = int1l & int2l, hi = int1h & int2h;
1111 case BIT_ANDTC_EXPR:
1112 low = int1l & ~int2l, hi = int1h & ~int2h;
1118 /* It's unclear from the C standard whether shifts can overflow.
1119 The following code ignores overflow; perhaps a C standard
1120 interpretation ruling is needed. */
1121 lshift_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1129 lrotate_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1134 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1138 neg_double (int2l, int2h, &low, &hi);
1139 add_double (int1l, int1h, low, hi, &low, &hi);
1140 overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
1144 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1147 case TRUNC_DIV_EXPR:
1148 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1149 case EXACT_DIV_EXPR:
1150 /* This is a shortcut for a common special case. */
1151 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1152 && ! TREE_CONSTANT_OVERFLOW (arg1)
1153 && ! TREE_CONSTANT_OVERFLOW (arg2)
1154 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1156 if (code == CEIL_DIV_EXPR)
1159 low = int1l / int2l, hi = 0;
1163 /* ... fall through ... */
1165 case ROUND_DIV_EXPR:
1166 if (int2h == 0 && int2l == 1)
1168 low = int1l, hi = int1h;
1171 if (int1l == int2l && int1h == int2h
1172 && ! (int1l == 0 && int1h == 0))
1177 overflow = div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
1178 &low, &hi, &garbagel, &garbageh);
1181 case TRUNC_MOD_EXPR:
1182 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1183 /* This is a shortcut for a common special case. */
1184 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1185 && ! TREE_CONSTANT_OVERFLOW (arg1)
1186 && ! TREE_CONSTANT_OVERFLOW (arg2)
1187 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1189 if (code == CEIL_MOD_EXPR)
1191 low = int1l % int2l, hi = 0;
1195 /* ... fall through ... */
1197 case ROUND_MOD_EXPR:
1198 overflow = div_and_round_double (code, uns,
1199 int1l, int1h, int2l, int2h,
1200 &garbagel, &garbageh, &low, &hi);
1206 low = (((unsigned HOST_WIDE_INT) int1h
1207 < (unsigned HOST_WIDE_INT) int2h)
1208 || (((unsigned HOST_WIDE_INT) int1h
1209 == (unsigned HOST_WIDE_INT) int2h)
1212 low = (int1h < int2h
1213 || (int1h == int2h && int1l < int2l));
1215 if (low == (code == MIN_EXPR))
1216 low = int1l, hi = int1h;
1218 low = int2l, hi = int2h;
1225 /* If this is for a sizetype, can be represented as one (signed)
1226 HOST_WIDE_INT word, and doesn't overflow, use size_int since it caches
1229 && ((hi == 0 && (HOST_WIDE_INT) low >= 0)
1230 || (hi == -1 && (HOST_WIDE_INT) low < 0))
1231 && overflow == 0 && ! TREE_OVERFLOW (arg1) && ! TREE_OVERFLOW (arg2))
1232 return size_int_type_wide (low, type);
1235 t = build_int_2 (low, hi);
1236 TREE_TYPE (t) = TREE_TYPE (arg1);
1241 ? (!uns || is_sizetype) && overflow
1242 : (force_fit_type (t, (!uns || is_sizetype) && overflow)
1244 | TREE_OVERFLOW (arg1)
1245 | TREE_OVERFLOW (arg2));
1247 /* If we're doing a size calculation, unsigned arithmetic does overflow.
1248 So check if force_fit_type truncated the value. */
1250 && ! TREE_OVERFLOW (t)
1251 && (TREE_INT_CST_HIGH (t) != hi
1252 || TREE_INT_CST_LOW (t) != low))
1253 TREE_OVERFLOW (t) = 1;
1255 TREE_CONSTANT_OVERFLOW (t) = (TREE_OVERFLOW (t)
1256 | TREE_CONSTANT_OVERFLOW (arg1)
1257 | TREE_CONSTANT_OVERFLOW (arg2));
1261 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1262 constant. We assume ARG1 and ARG2 have the same data type, or at least
1263 are the same kind of constant and the same machine mode.
1265 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1268 const_binop (code, arg1, arg2, notrunc)
1269 enum tree_code code;
1276 if (TREE_CODE (arg1) == INTEGER_CST)
1277 return int_const_binop (code, arg1, arg2, notrunc);
1279 if (TREE_CODE (arg1) == REAL_CST)
1283 REAL_VALUE_TYPE value;
1286 d1 = TREE_REAL_CST (arg1);
1287 d2 = TREE_REAL_CST (arg2);
1289 /* If either operand is a NaN, just return it. Otherwise, set up
1290 for floating-point trap; we return an overflow. */
1291 if (REAL_VALUE_ISNAN (d1))
1293 else if (REAL_VALUE_ISNAN (d2))
1296 REAL_ARITHMETIC (value, code, d1, d2);
1298 t = build_real (TREE_TYPE (arg1),
1299 real_value_truncate (TYPE_MODE (TREE_TYPE (arg1)),
1303 = (force_fit_type (t, 0)
1304 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
1305 TREE_CONSTANT_OVERFLOW (t)
1307 | TREE_CONSTANT_OVERFLOW (arg1)
1308 | TREE_CONSTANT_OVERFLOW (arg2);
1311 if (TREE_CODE (arg1) == COMPLEX_CST)
1313 tree type = TREE_TYPE (arg1);
1314 tree r1 = TREE_REALPART (arg1);
1315 tree i1 = TREE_IMAGPART (arg1);
1316 tree r2 = TREE_REALPART (arg2);
1317 tree i2 = TREE_IMAGPART (arg2);
1323 t = build_complex (type,
1324 const_binop (PLUS_EXPR, r1, r2, notrunc),
1325 const_binop (PLUS_EXPR, i1, i2, notrunc));
1329 t = build_complex (type,
1330 const_binop (MINUS_EXPR, r1, r2, notrunc),
1331 const_binop (MINUS_EXPR, i1, i2, notrunc));
1335 t = build_complex (type,
1336 const_binop (MINUS_EXPR,
1337 const_binop (MULT_EXPR,
1339 const_binop (MULT_EXPR,
1342 const_binop (PLUS_EXPR,
1343 const_binop (MULT_EXPR,
1345 const_binop (MULT_EXPR,
1353 = const_binop (PLUS_EXPR,
1354 const_binop (MULT_EXPR, r2, r2, notrunc),
1355 const_binop (MULT_EXPR, i2, i2, notrunc),
1358 t = build_complex (type,
1360 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1361 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1362 const_binop (PLUS_EXPR,
1363 const_binop (MULT_EXPR, r1, r2,
1365 const_binop (MULT_EXPR, i1, i2,
1368 magsquared, notrunc),
1370 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1371 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1372 const_binop (MINUS_EXPR,
1373 const_binop (MULT_EXPR, i1, r2,
1375 const_binop (MULT_EXPR, r1, i2,
1378 magsquared, notrunc));
1390 /* These are the hash table functions for the hash table of INTEGER_CST
1391 nodes of a sizetype. */
1393 /* Return the hash code code X, an INTEGER_CST. */
1401 return (TREE_INT_CST_HIGH (t) ^ TREE_INT_CST_LOW (t)
1402 ^ htab_hash_pointer (TREE_TYPE (t))
1403 ^ (TREE_OVERFLOW (t) << 20));
1406 /* Return nonzero if the value represented by *X (an INTEGER_CST tree node)
1407 is the same as that given by *Y, which is the same. */
1417 return (TREE_INT_CST_HIGH (xt) == TREE_INT_CST_HIGH (yt)
1418 && TREE_INT_CST_LOW (xt) == TREE_INT_CST_LOW (yt)
1419 && TREE_TYPE (xt) == TREE_TYPE (yt)
1420 && TREE_OVERFLOW (xt) == TREE_OVERFLOW (yt));
1423 /* Return an INTEGER_CST with value whose low-order HOST_BITS_PER_WIDE_INT
1424 bits are given by NUMBER and of the sizetype represented by KIND. */
1427 size_int_wide (number, kind)
1428 HOST_WIDE_INT number;
1429 enum size_type_kind kind;
1431 return size_int_type_wide (number, sizetype_tab[(int) kind]);
1434 /* Likewise, but the desired type is specified explicitly. */
1436 static GTY (()) tree new_const;
1437 static GTY ((if_marked ("ggc_marked_p"), param_is (union tree_node)))
1441 size_int_type_wide (number, type)
1442 HOST_WIDE_INT number;
1449 size_htab = htab_create_ggc (1024, size_htab_hash, size_htab_eq, NULL);
1450 new_const = make_node (INTEGER_CST);
1453 /* Adjust NEW_CONST to be the constant we want. If it's already in the
1454 hash table, we return the value from the hash table. Otherwise, we
1455 place that in the hash table and make a new node for the next time. */
1456 TREE_INT_CST_LOW (new_const) = number;
1457 TREE_INT_CST_HIGH (new_const) = number < 0 ? -1 : 0;
1458 TREE_TYPE (new_const) = type;
1459 TREE_OVERFLOW (new_const) = TREE_CONSTANT_OVERFLOW (new_const)
1460 = force_fit_type (new_const, 0);
1462 slot = htab_find_slot (size_htab, new_const, INSERT);
1467 *slot = (PTR) new_const;
1468 new_const = make_node (INTEGER_CST);
1472 return (tree) *slot;
1475 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1476 is a tree code. The type of the result is taken from the operands.
1477 Both must be the same type integer type and it must be a size type.
1478 If the operands are constant, so is the result. */
1481 size_binop (code, arg0, arg1)
1482 enum tree_code code;
1485 tree type = TREE_TYPE (arg0);
1487 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1488 || type != TREE_TYPE (arg1))
1491 /* Handle the special case of two integer constants faster. */
1492 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1494 /* And some specific cases even faster than that. */
1495 if (code == PLUS_EXPR && integer_zerop (arg0))
1497 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1498 && integer_zerop (arg1))
1500 else if (code == MULT_EXPR && integer_onep (arg0))
1503 /* Handle general case of two integer constants. */
1504 return int_const_binop (code, arg0, arg1, 0);
1507 if (arg0 == error_mark_node || arg1 == error_mark_node)
1508 return error_mark_node;
1510 return fold (build (code, type, arg0, arg1));
1513 /* Given two values, either both of sizetype or both of bitsizetype,
1514 compute the difference between the two values. Return the value
1515 in signed type corresponding to the type of the operands. */
1518 size_diffop (arg0, arg1)
1521 tree type = TREE_TYPE (arg0);
1524 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1525 || type != TREE_TYPE (arg1))
1528 /* If the type is already signed, just do the simple thing. */
1529 if (! TREE_UNSIGNED (type))
1530 return size_binop (MINUS_EXPR, arg0, arg1);
1532 ctype = (type == bitsizetype || type == ubitsizetype
1533 ? sbitsizetype : ssizetype);
1535 /* If either operand is not a constant, do the conversions to the signed
1536 type and subtract. The hardware will do the right thing with any
1537 overflow in the subtraction. */
1538 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
1539 return size_binop (MINUS_EXPR, convert (ctype, arg0),
1540 convert (ctype, arg1));
1542 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
1543 Otherwise, subtract the other way, convert to CTYPE (we know that can't
1544 overflow) and negate (which can't either). Special-case a result
1545 of zero while we're here. */
1546 if (tree_int_cst_equal (arg0, arg1))
1547 return convert (ctype, integer_zero_node);
1548 else if (tree_int_cst_lt (arg1, arg0))
1549 return convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
1551 return size_binop (MINUS_EXPR, convert (ctype, integer_zero_node),
1552 convert (ctype, size_binop (MINUS_EXPR, arg1, arg0)));
1556 /* Given T, a tree representing type conversion of ARG1, a constant,
1557 return a constant tree representing the result of conversion. */
1560 fold_convert (t, arg1)
1564 tree type = TREE_TYPE (t);
1567 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
1569 if (TREE_CODE (arg1) == INTEGER_CST)
1571 /* If we would build a constant wider than GCC supports,
1572 leave the conversion unfolded. */
1573 if (TYPE_PRECISION (type) > 2 * HOST_BITS_PER_WIDE_INT)
1576 /* If we are trying to make a sizetype for a small integer, use
1577 size_int to pick up cached types to reduce duplicate nodes. */
1578 if (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type)
1579 && !TREE_CONSTANT_OVERFLOW (arg1)
1580 && compare_tree_int (arg1, 10000) < 0)
1581 return size_int_type_wide (TREE_INT_CST_LOW (arg1), type);
1583 /* Given an integer constant, make new constant with new type,
1584 appropriately sign-extended or truncated. */
1585 t = build_int_2 (TREE_INT_CST_LOW (arg1),
1586 TREE_INT_CST_HIGH (arg1));
1587 TREE_TYPE (t) = type;
1588 /* Indicate an overflow if (1) ARG1 already overflowed,
1589 or (2) force_fit_type indicates an overflow.
1590 Tell force_fit_type that an overflow has already occurred
1591 if ARG1 is a too-large unsigned value and T is signed.
1592 But don't indicate an overflow if converting a pointer. */
1594 = ((force_fit_type (t,
1595 (TREE_INT_CST_HIGH (arg1) < 0
1596 && (TREE_UNSIGNED (type)
1597 < TREE_UNSIGNED (TREE_TYPE (arg1)))))
1598 && ! POINTER_TYPE_P (TREE_TYPE (arg1)))
1599 || TREE_OVERFLOW (arg1));
1600 TREE_CONSTANT_OVERFLOW (t)
1601 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1603 else if (TREE_CODE (arg1) == REAL_CST)
1605 /* Don't initialize these, use assignments.
1606 Initialized local aggregates don't work on old compilers. */
1610 tree type1 = TREE_TYPE (arg1);
1613 x = TREE_REAL_CST (arg1);
1614 l = real_value_from_int_cst (type1, TYPE_MIN_VALUE (type));
1616 no_upper_bound = (TYPE_MAX_VALUE (type) == NULL);
1617 if (!no_upper_bound)
1618 u = real_value_from_int_cst (type1, TYPE_MAX_VALUE (type));
1620 /* See if X will be in range after truncation towards 0.
1621 To compensate for truncation, move the bounds away from 0,
1622 but reject if X exactly equals the adjusted bounds. */
1623 REAL_ARITHMETIC (l, MINUS_EXPR, l, dconst1);
1624 if (!no_upper_bound)
1625 REAL_ARITHMETIC (u, PLUS_EXPR, u, dconst1);
1626 /* If X is a NaN, use zero instead and show we have an overflow.
1627 Otherwise, range check. */
1628 if (REAL_VALUE_ISNAN (x))
1629 overflow = 1, x = dconst0;
1630 else if (! (REAL_VALUES_LESS (l, x)
1632 && REAL_VALUES_LESS (x, u)))
1636 HOST_WIDE_INT low, high;
1637 REAL_VALUE_TO_INT (&low, &high, x);
1638 t = build_int_2 (low, high);
1640 TREE_TYPE (t) = type;
1642 = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
1643 TREE_CONSTANT_OVERFLOW (t)
1644 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1646 TREE_TYPE (t) = type;
1648 else if (TREE_CODE (type) == REAL_TYPE)
1650 if (TREE_CODE (arg1) == INTEGER_CST)
1651 return build_real_from_int_cst (type, arg1);
1652 if (TREE_CODE (arg1) == REAL_CST)
1654 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
1656 /* We make a copy of ARG1 so that we don't modify an
1657 existing constant tree. */
1658 t = copy_node (arg1);
1659 TREE_TYPE (t) = type;
1663 t = build_real (type,
1664 real_value_truncate (TYPE_MODE (type),
1665 TREE_REAL_CST (arg1)));
1668 = TREE_OVERFLOW (arg1) | force_fit_type (t, 0);
1669 TREE_CONSTANT_OVERFLOW (t)
1670 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1674 TREE_CONSTANT (t) = 1;
1678 /* Return an expr equal to X but certainly not valid as an lvalue. */
1686 /* These things are certainly not lvalues. */
1687 if (TREE_CODE (x) == NON_LVALUE_EXPR
1688 || TREE_CODE (x) == INTEGER_CST
1689 || TREE_CODE (x) == REAL_CST
1690 || TREE_CODE (x) == STRING_CST
1691 || TREE_CODE (x) == ADDR_EXPR)
1694 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
1695 TREE_CONSTANT (result) = TREE_CONSTANT (x);
1699 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
1700 Zero means allow extended lvalues. */
1702 int pedantic_lvalues;
1704 /* When pedantic, return an expr equal to X but certainly not valid as a
1705 pedantic lvalue. Otherwise, return X. */
1708 pedantic_non_lvalue (x)
1711 if (pedantic_lvalues)
1712 return non_lvalue (x);
1717 /* Given a tree comparison code, return the code that is the logical inverse
1718 of the given code. It is not safe to do this for floating-point
1719 comparisons, except for NE_EXPR and EQ_EXPR. */
1721 static enum tree_code
1722 invert_tree_comparison (code)
1723 enum tree_code code;
1744 /* Similar, but return the comparison that results if the operands are
1745 swapped. This is safe for floating-point. */
1747 static enum tree_code
1748 swap_tree_comparison (code)
1749 enum tree_code code;
1770 /* Convert a comparison tree code from an enum tree_code representation
1771 into a compcode bit-based encoding. This function is the inverse of
1772 compcode_to_comparison. */
1775 comparison_to_compcode (code)
1776 enum tree_code code;
1797 /* Convert a compcode bit-based encoding of a comparison operator back
1798 to GCC's enum tree_code representation. This function is the
1799 inverse of comparison_to_compcode. */
1801 static enum tree_code
1802 compcode_to_comparison (code)
1824 /* Return nonzero if CODE is a tree code that represents a truth value. */
1827 truth_value_p (code)
1828 enum tree_code code;
1830 return (TREE_CODE_CLASS (code) == '<'
1831 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
1832 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
1833 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
1836 /* Return nonzero if two operands are necessarily equal.
1837 If ONLY_CONST is nonzero, only return nonzero for constants.
1838 This function tests whether the operands are indistinguishable;
1839 it does not test whether they are equal using C's == operation.
1840 The distinction is important for IEEE floating point, because
1841 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
1842 (2) two NaNs may be indistinguishable, but NaN!=NaN. */
1845 operand_equal_p (arg0, arg1, only_const)
1849 /* If both types don't have the same signedness, then we can't consider
1850 them equal. We must check this before the STRIP_NOPS calls
1851 because they may change the signedness of the arguments. */
1852 if (TREE_UNSIGNED (TREE_TYPE (arg0)) != TREE_UNSIGNED (TREE_TYPE (arg1)))
1858 if (TREE_CODE (arg0) != TREE_CODE (arg1)
1859 /* This is needed for conversions and for COMPONENT_REF.
1860 Might as well play it safe and always test this. */
1861 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
1862 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
1863 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
1866 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
1867 We don't care about side effects in that case because the SAVE_EXPR
1868 takes care of that for us. In all other cases, two expressions are
1869 equal if they have no side effects. If we have two identical
1870 expressions with side effects that should be treated the same due
1871 to the only side effects being identical SAVE_EXPR's, that will
1872 be detected in the recursive calls below. */
1873 if (arg0 == arg1 && ! only_const
1874 && (TREE_CODE (arg0) == SAVE_EXPR
1875 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
1878 /* Next handle constant cases, those for which we can return 1 even
1879 if ONLY_CONST is set. */
1880 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
1881 switch (TREE_CODE (arg0))
1884 return (! TREE_CONSTANT_OVERFLOW (arg0)
1885 && ! TREE_CONSTANT_OVERFLOW (arg1)
1886 && tree_int_cst_equal (arg0, arg1));
1889 return (! TREE_CONSTANT_OVERFLOW (arg0)
1890 && ! TREE_CONSTANT_OVERFLOW (arg1)
1891 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
1892 TREE_REAL_CST (arg1)));
1898 if (TREE_CONSTANT_OVERFLOW (arg0)
1899 || TREE_CONSTANT_OVERFLOW (arg1))
1902 v1 = TREE_VECTOR_CST_ELTS (arg0);
1903 v2 = TREE_VECTOR_CST_ELTS (arg1);
1906 if (!operand_equal_p (v1, v2, only_const))
1908 v1 = TREE_CHAIN (v1);
1909 v2 = TREE_CHAIN (v2);
1916 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
1918 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
1922 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
1923 && ! memcmp (TREE_STRING_POINTER (arg0),
1924 TREE_STRING_POINTER (arg1),
1925 TREE_STRING_LENGTH (arg0)));
1928 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
1937 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
1940 /* Two conversions are equal only if signedness and modes match. */
1941 if ((TREE_CODE (arg0) == NOP_EXPR || TREE_CODE (arg0) == CONVERT_EXPR)
1942 && (TREE_UNSIGNED (TREE_TYPE (arg0))
1943 != TREE_UNSIGNED (TREE_TYPE (arg1))))
1946 return operand_equal_p (TREE_OPERAND (arg0, 0),
1947 TREE_OPERAND (arg1, 0), 0);
1951 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0)
1952 && operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1),
1956 /* For commutative ops, allow the other order. */
1957 return ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MULT_EXPR
1958 || TREE_CODE (arg0) == MIN_EXPR || TREE_CODE (arg0) == MAX_EXPR
1959 || TREE_CODE (arg0) == BIT_IOR_EXPR
1960 || TREE_CODE (arg0) == BIT_XOR_EXPR
1961 || TREE_CODE (arg0) == BIT_AND_EXPR
1962 || TREE_CODE (arg0) == NE_EXPR || TREE_CODE (arg0) == EQ_EXPR)
1963 && operand_equal_p (TREE_OPERAND (arg0, 0),
1964 TREE_OPERAND (arg1, 1), 0)
1965 && operand_equal_p (TREE_OPERAND (arg0, 1),
1966 TREE_OPERAND (arg1, 0), 0));
1969 /* If either of the pointer (or reference) expressions we are dereferencing
1970 contain a side effect, these cannot be equal. */
1971 if (TREE_SIDE_EFFECTS (arg0)
1972 || TREE_SIDE_EFFECTS (arg1))
1975 switch (TREE_CODE (arg0))
1978 return operand_equal_p (TREE_OPERAND (arg0, 0),
1979 TREE_OPERAND (arg1, 0), 0);
1983 case ARRAY_RANGE_REF:
1984 return (operand_equal_p (TREE_OPERAND (arg0, 0),
1985 TREE_OPERAND (arg1, 0), 0)
1986 && operand_equal_p (TREE_OPERAND (arg0, 1),
1987 TREE_OPERAND (arg1, 1), 0));
1990 return (operand_equal_p (TREE_OPERAND (arg0, 0),
1991 TREE_OPERAND (arg1, 0), 0)
1992 && operand_equal_p (TREE_OPERAND (arg0, 1),
1993 TREE_OPERAND (arg1, 1), 0)
1994 && operand_equal_p (TREE_OPERAND (arg0, 2),
1995 TREE_OPERAND (arg1, 2), 0));
2001 if (TREE_CODE (arg0) == RTL_EXPR)
2002 return rtx_equal_p (RTL_EXPR_RTL (arg0), RTL_EXPR_RTL (arg1));
2010 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2011 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2013 When in doubt, return 0. */
2016 operand_equal_for_comparison_p (arg0, arg1, other)
2020 int unsignedp1, unsignedpo;
2021 tree primarg0, primarg1, primother;
2022 unsigned int correct_width;
2024 if (operand_equal_p (arg0, arg1, 0))
2027 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
2028 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
2031 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2032 and see if the inner values are the same. This removes any
2033 signedness comparison, which doesn't matter here. */
2034 primarg0 = arg0, primarg1 = arg1;
2035 STRIP_NOPS (primarg0);
2036 STRIP_NOPS (primarg1);
2037 if (operand_equal_p (primarg0, primarg1, 0))
2040 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2041 actual comparison operand, ARG0.
2043 First throw away any conversions to wider types
2044 already present in the operands. */
2046 primarg1 = get_narrower (arg1, &unsignedp1);
2047 primother = get_narrower (other, &unsignedpo);
2049 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
2050 if (unsignedp1 == unsignedpo
2051 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
2052 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
2054 tree type = TREE_TYPE (arg0);
2056 /* Make sure shorter operand is extended the right way
2057 to match the longer operand. */
2058 primarg1 = convert ((*lang_hooks.types.signed_or_unsigned_type)
2059 (unsignedp1, TREE_TYPE (primarg1)), primarg1);
2061 if (operand_equal_p (arg0, convert (type, primarg1), 0))
2068 /* See if ARG is an expression that is either a comparison or is performing
2069 arithmetic on comparisons. The comparisons must only be comparing
2070 two different values, which will be stored in *CVAL1 and *CVAL2; if
2071 they are nonzero it means that some operands have already been found.
2072 No variables may be used anywhere else in the expression except in the
2073 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2074 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2076 If this is true, return 1. Otherwise, return zero. */
2079 twoval_comparison_p (arg, cval1, cval2, save_p)
2081 tree *cval1, *cval2;
2084 enum tree_code code = TREE_CODE (arg);
2085 char class = TREE_CODE_CLASS (code);
2087 /* We can handle some of the 'e' cases here. */
2088 if (class == 'e' && code == TRUTH_NOT_EXPR)
2090 else if (class == 'e'
2091 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
2092 || code == COMPOUND_EXPR))
2095 else if (class == 'e' && code == SAVE_EXPR && SAVE_EXPR_RTL (arg) == 0
2096 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
2098 /* If we've already found a CVAL1 or CVAL2, this expression is
2099 two complex to handle. */
2100 if (*cval1 || *cval2)
2110 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
2113 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
2114 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2115 cval1, cval2, save_p));
2121 if (code == COND_EXPR)
2122 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
2123 cval1, cval2, save_p)
2124 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2125 cval1, cval2, save_p)
2126 && twoval_comparison_p (TREE_OPERAND (arg, 2),
2127 cval1, cval2, save_p));
2131 /* First see if we can handle the first operand, then the second. For
2132 the second operand, we know *CVAL1 can't be zero. It must be that
2133 one side of the comparison is each of the values; test for the
2134 case where this isn't true by failing if the two operands
2137 if (operand_equal_p (TREE_OPERAND (arg, 0),
2138 TREE_OPERAND (arg, 1), 0))
2142 *cval1 = TREE_OPERAND (arg, 0);
2143 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
2145 else if (*cval2 == 0)
2146 *cval2 = TREE_OPERAND (arg, 0);
2147 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
2152 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
2154 else if (*cval2 == 0)
2155 *cval2 = TREE_OPERAND (arg, 1);
2156 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
2168 /* ARG is a tree that is known to contain just arithmetic operations and
2169 comparisons. Evaluate the operations in the tree substituting NEW0 for
2170 any occurrence of OLD0 as an operand of a comparison and likewise for
2174 eval_subst (arg, old0, new0, old1, new1)
2176 tree old0, new0, old1, new1;
2178 tree type = TREE_TYPE (arg);
2179 enum tree_code code = TREE_CODE (arg);
2180 char class = TREE_CODE_CLASS (code);
2182 /* We can handle some of the 'e' cases here. */
2183 if (class == 'e' && code == TRUTH_NOT_EXPR)
2185 else if (class == 'e'
2186 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2192 return fold (build1 (code, type,
2193 eval_subst (TREE_OPERAND (arg, 0),
2194 old0, new0, old1, new1)));
2197 return fold (build (code, type,
2198 eval_subst (TREE_OPERAND (arg, 0),
2199 old0, new0, old1, new1),
2200 eval_subst (TREE_OPERAND (arg, 1),
2201 old0, new0, old1, new1)));
2207 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
2210 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
2213 return fold (build (code, type,
2214 eval_subst (TREE_OPERAND (arg, 0),
2215 old0, new0, old1, new1),
2216 eval_subst (TREE_OPERAND (arg, 1),
2217 old0, new0, old1, new1),
2218 eval_subst (TREE_OPERAND (arg, 2),
2219 old0, new0, old1, new1)));
2223 /* fall through - ??? */
2227 tree arg0 = TREE_OPERAND (arg, 0);
2228 tree arg1 = TREE_OPERAND (arg, 1);
2230 /* We need to check both for exact equality and tree equality. The
2231 former will be true if the operand has a side-effect. In that
2232 case, we know the operand occurred exactly once. */
2234 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
2236 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
2239 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
2241 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
2244 return fold (build (code, type, arg0, arg1));
2252 /* Return a tree for the case when the result of an expression is RESULT
2253 converted to TYPE and OMITTED was previously an operand of the expression
2254 but is now not needed (e.g., we folded OMITTED * 0).
2256 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2257 the conversion of RESULT to TYPE. */
2260 omit_one_operand (type, result, omitted)
2261 tree type, result, omitted;
2263 tree t = convert (type, result);
2265 if (TREE_SIDE_EFFECTS (omitted))
2266 return build (COMPOUND_EXPR, type, omitted, t);
2268 return non_lvalue (t);
2271 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2274 pedantic_omit_one_operand (type, result, omitted)
2275 tree type, result, omitted;
2277 tree t = convert (type, result);
2279 if (TREE_SIDE_EFFECTS (omitted))
2280 return build (COMPOUND_EXPR, type, omitted, t);
2282 return pedantic_non_lvalue (t);
2285 /* Return a simplified tree node for the truth-negation of ARG. This
2286 never alters ARG itself. We assume that ARG is an operation that
2287 returns a truth value (0 or 1). */
2290 invert_truthvalue (arg)
2293 tree type = TREE_TYPE (arg);
2294 enum tree_code code = TREE_CODE (arg);
2296 if (code == ERROR_MARK)
2299 /* If this is a comparison, we can simply invert it, except for
2300 floating-point non-equality comparisons, in which case we just
2301 enclose a TRUTH_NOT_EXPR around what we have. */
2303 if (TREE_CODE_CLASS (code) == '<')
2305 if (FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg, 0)))
2306 && !flag_unsafe_math_optimizations
2309 return build1 (TRUTH_NOT_EXPR, type, arg);
2311 return build (invert_tree_comparison (code), type,
2312 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
2318 return convert (type, build_int_2 (integer_zerop (arg), 0));
2320 case TRUTH_AND_EXPR:
2321 return build (TRUTH_OR_EXPR, type,
2322 invert_truthvalue (TREE_OPERAND (arg, 0)),
2323 invert_truthvalue (TREE_OPERAND (arg, 1)));
2326 return build (TRUTH_AND_EXPR, type,
2327 invert_truthvalue (TREE_OPERAND (arg, 0)),
2328 invert_truthvalue (TREE_OPERAND (arg, 1)));
2330 case TRUTH_XOR_EXPR:
2331 /* Here we can invert either operand. We invert the first operand
2332 unless the second operand is a TRUTH_NOT_EXPR in which case our
2333 result is the XOR of the first operand with the inside of the
2334 negation of the second operand. */
2336 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
2337 return build (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
2338 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
2340 return build (TRUTH_XOR_EXPR, type,
2341 invert_truthvalue (TREE_OPERAND (arg, 0)),
2342 TREE_OPERAND (arg, 1));
2344 case TRUTH_ANDIF_EXPR:
2345 return build (TRUTH_ORIF_EXPR, type,
2346 invert_truthvalue (TREE_OPERAND (arg, 0)),
2347 invert_truthvalue (TREE_OPERAND (arg, 1)));
2349 case TRUTH_ORIF_EXPR:
2350 return build (TRUTH_ANDIF_EXPR, type,
2351 invert_truthvalue (TREE_OPERAND (arg, 0)),
2352 invert_truthvalue (TREE_OPERAND (arg, 1)));
2354 case TRUTH_NOT_EXPR:
2355 return TREE_OPERAND (arg, 0);
2358 return build (COND_EXPR, type, TREE_OPERAND (arg, 0),
2359 invert_truthvalue (TREE_OPERAND (arg, 1)),
2360 invert_truthvalue (TREE_OPERAND (arg, 2)));
2363 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
2364 invert_truthvalue (TREE_OPERAND (arg, 1)));
2366 case WITH_RECORD_EXPR:
2367 return build (WITH_RECORD_EXPR, type,
2368 invert_truthvalue (TREE_OPERAND (arg, 0)),
2369 TREE_OPERAND (arg, 1));
2371 case NON_LVALUE_EXPR:
2372 return invert_truthvalue (TREE_OPERAND (arg, 0));
2377 return build1 (TREE_CODE (arg), type,
2378 invert_truthvalue (TREE_OPERAND (arg, 0)));
2381 if (!integer_onep (TREE_OPERAND (arg, 1)))
2383 return build (EQ_EXPR, type, arg, convert (type, integer_zero_node));
2386 return build1 (TRUTH_NOT_EXPR, type, arg);
2388 case CLEANUP_POINT_EXPR:
2389 return build1 (CLEANUP_POINT_EXPR, type,
2390 invert_truthvalue (TREE_OPERAND (arg, 0)));
2395 if (TREE_CODE (TREE_TYPE (arg)) != BOOLEAN_TYPE)
2397 return build1 (TRUTH_NOT_EXPR, type, arg);
2400 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
2401 operands are another bit-wise operation with a common input. If so,
2402 distribute the bit operations to save an operation and possibly two if
2403 constants are involved. For example, convert
2404 (A | B) & (A | C) into A | (B & C)
2405 Further simplification will occur if B and C are constants.
2407 If this optimization cannot be done, 0 will be returned. */
2410 distribute_bit_expr (code, type, arg0, arg1)
2411 enum tree_code code;
2418 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2419 || TREE_CODE (arg0) == code
2420 || (TREE_CODE (arg0) != BIT_AND_EXPR
2421 && TREE_CODE (arg0) != BIT_IOR_EXPR))
2424 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
2426 common = TREE_OPERAND (arg0, 0);
2427 left = TREE_OPERAND (arg0, 1);
2428 right = TREE_OPERAND (arg1, 1);
2430 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
2432 common = TREE_OPERAND (arg0, 0);
2433 left = TREE_OPERAND (arg0, 1);
2434 right = TREE_OPERAND (arg1, 0);
2436 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
2438 common = TREE_OPERAND (arg0, 1);
2439 left = TREE_OPERAND (arg0, 0);
2440 right = TREE_OPERAND (arg1, 1);
2442 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
2444 common = TREE_OPERAND (arg0, 1);
2445 left = TREE_OPERAND (arg0, 0);
2446 right = TREE_OPERAND (arg1, 0);
2451 return fold (build (TREE_CODE (arg0), type, common,
2452 fold (build (code, type, left, right))));
2455 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
2456 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
2459 make_bit_field_ref (inner, type, bitsize, bitpos, unsignedp)
2462 int bitsize, bitpos;
2465 tree result = build (BIT_FIELD_REF, type, inner,
2466 size_int (bitsize), bitsize_int (bitpos));
2468 TREE_UNSIGNED (result) = unsignedp;
2473 /* Optimize a bit-field compare.
2475 There are two cases: First is a compare against a constant and the
2476 second is a comparison of two items where the fields are at the same
2477 bit position relative to the start of a chunk (byte, halfword, word)
2478 large enough to contain it. In these cases we can avoid the shift
2479 implicit in bitfield extractions.
2481 For constants, we emit a compare of the shifted constant with the
2482 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
2483 compared. For two fields at the same position, we do the ANDs with the
2484 similar mask and compare the result of the ANDs.
2486 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
2487 COMPARE_TYPE is the type of the comparison, and LHS and RHS
2488 are the left and right operands of the comparison, respectively.
2490 If the optimization described above can be done, we return the resulting
2491 tree. Otherwise we return zero. */
2494 optimize_bit_field_compare (code, compare_type, lhs, rhs)
2495 enum tree_code code;
2499 HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
2500 tree type = TREE_TYPE (lhs);
2501 tree signed_type, unsigned_type;
2502 int const_p = TREE_CODE (rhs) == INTEGER_CST;
2503 enum machine_mode lmode, rmode, nmode;
2504 int lunsignedp, runsignedp;
2505 int lvolatilep = 0, rvolatilep = 0;
2506 tree linner, rinner = NULL_TREE;
2510 /* Get all the information about the extractions being done. If the bit size
2511 if the same as the size of the underlying object, we aren't doing an
2512 extraction at all and so can do nothing. We also don't want to
2513 do anything if the inner expression is a PLACEHOLDER_EXPR since we
2514 then will no longer be able to replace it. */
2515 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
2516 &lunsignedp, &lvolatilep);
2517 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
2518 || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
2523 /* If this is not a constant, we can only do something if bit positions,
2524 sizes, and signedness are the same. */
2525 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
2526 &runsignedp, &rvolatilep);
2528 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
2529 || lunsignedp != runsignedp || offset != 0
2530 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
2534 /* See if we can find a mode to refer to this field. We should be able to,
2535 but fail if we can't. */
2536 nmode = get_best_mode (lbitsize, lbitpos,
2537 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
2538 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
2539 TYPE_ALIGN (TREE_TYPE (rinner))),
2540 word_mode, lvolatilep || rvolatilep);
2541 if (nmode == VOIDmode)
2544 /* Set signed and unsigned types of the precision of this mode for the
2546 signed_type = (*lang_hooks.types.type_for_mode) (nmode, 0);
2547 unsigned_type = (*lang_hooks.types.type_for_mode) (nmode, 1);
2549 /* Compute the bit position and size for the new reference and our offset
2550 within it. If the new reference is the same size as the original, we
2551 won't optimize anything, so return zero. */
2552 nbitsize = GET_MODE_BITSIZE (nmode);
2553 nbitpos = lbitpos & ~ (nbitsize - 1);
2555 if (nbitsize == lbitsize)
2558 if (BYTES_BIG_ENDIAN)
2559 lbitpos = nbitsize - lbitsize - lbitpos;
2561 /* Make the mask to be used against the extracted field. */
2562 mask = build_int_2 (~0, ~0);
2563 TREE_TYPE (mask) = unsigned_type;
2564 force_fit_type (mask, 0);
2565 mask = convert (unsigned_type, mask);
2566 mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
2567 mask = const_binop (RSHIFT_EXPR, mask,
2568 size_int (nbitsize - lbitsize - lbitpos), 0);
2571 /* If not comparing with constant, just rework the comparison
2573 return build (code, compare_type,
2574 build (BIT_AND_EXPR, unsigned_type,
2575 make_bit_field_ref (linner, unsigned_type,
2576 nbitsize, nbitpos, 1),
2578 build (BIT_AND_EXPR, unsigned_type,
2579 make_bit_field_ref (rinner, unsigned_type,
2580 nbitsize, nbitpos, 1),
2583 /* Otherwise, we are handling the constant case. See if the constant is too
2584 big for the field. Warn and return a tree of for 0 (false) if so. We do
2585 this not only for its own sake, but to avoid having to test for this
2586 error case below. If we didn't, we might generate wrong code.
2588 For unsigned fields, the constant shifted right by the field length should
2589 be all zero. For signed fields, the high-order bits should agree with
2594 if (! integer_zerop (const_binop (RSHIFT_EXPR,
2595 convert (unsigned_type, rhs),
2596 size_int (lbitsize), 0)))
2598 warning ("comparison is always %d due to width of bit-field",
2600 return convert (compare_type,
2602 ? integer_one_node : integer_zero_node));
2607 tree tem = const_binop (RSHIFT_EXPR, convert (signed_type, rhs),
2608 size_int (lbitsize - 1), 0);
2609 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
2611 warning ("comparison is always %d due to width of bit-field",
2613 return convert (compare_type,
2615 ? integer_one_node : integer_zero_node));
2619 /* Single-bit compares should always be against zero. */
2620 if (lbitsize == 1 && ! integer_zerop (rhs))
2622 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
2623 rhs = convert (type, integer_zero_node);
2626 /* Make a new bitfield reference, shift the constant over the
2627 appropriate number of bits and mask it with the computed mask
2628 (in case this was a signed field). If we changed it, make a new one. */
2629 lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1);
2632 TREE_SIDE_EFFECTS (lhs) = 1;
2633 TREE_THIS_VOLATILE (lhs) = 1;
2636 rhs = fold (const_binop (BIT_AND_EXPR,
2637 const_binop (LSHIFT_EXPR,
2638 convert (unsigned_type, rhs),
2639 size_int (lbitpos), 0),
2642 return build (code, compare_type,
2643 build (BIT_AND_EXPR, unsigned_type, lhs, mask),
2647 /* Subroutine for fold_truthop: decode a field reference.
2649 If EXP is a comparison reference, we return the innermost reference.
2651 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
2652 set to the starting bit number.
2654 If the innermost field can be completely contained in a mode-sized
2655 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
2657 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
2658 otherwise it is not changed.
2660 *PUNSIGNEDP is set to the signedness of the field.
2662 *PMASK is set to the mask used. This is either contained in a
2663 BIT_AND_EXPR or derived from the width of the field.
2665 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
2667 Return 0 if this is not a component reference or is one that we can't
2668 do anything with. */
2671 decode_field_reference (exp, pbitsize, pbitpos, pmode, punsignedp,
2672 pvolatilep, pmask, pand_mask)
2674 HOST_WIDE_INT *pbitsize, *pbitpos;
2675 enum machine_mode *pmode;
2676 int *punsignedp, *pvolatilep;
2681 tree mask, inner, offset;
2683 unsigned int precision;
2685 /* All the optimizations using this function assume integer fields.
2686 There are problems with FP fields since the type_for_size call
2687 below can fail for, e.g., XFmode. */
2688 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
2693 if (TREE_CODE (exp) == BIT_AND_EXPR)
2695 and_mask = TREE_OPERAND (exp, 1);
2696 exp = TREE_OPERAND (exp, 0);
2697 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
2698 if (TREE_CODE (and_mask) != INTEGER_CST)
2702 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
2703 punsignedp, pvolatilep);
2704 if ((inner == exp && and_mask == 0)
2705 || *pbitsize < 0 || offset != 0
2706 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
2709 /* Compute the mask to access the bitfield. */
2710 unsigned_type = (*lang_hooks.types.type_for_size) (*pbitsize, 1);
2711 precision = TYPE_PRECISION (unsigned_type);
2713 mask = build_int_2 (~0, ~0);
2714 TREE_TYPE (mask) = unsigned_type;
2715 force_fit_type (mask, 0);
2716 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
2717 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
2719 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
2721 mask = fold (build (BIT_AND_EXPR, unsigned_type,
2722 convert (unsigned_type, and_mask), mask));
2725 *pand_mask = and_mask;
2729 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
2733 all_ones_mask_p (mask, size)
2737 tree type = TREE_TYPE (mask);
2738 unsigned int precision = TYPE_PRECISION (type);
2741 tmask = build_int_2 (~0, ~0);
2742 TREE_TYPE (tmask) = (*lang_hooks.types.signed_type) (type);
2743 force_fit_type (tmask, 0);
2745 tree_int_cst_equal (mask,
2746 const_binop (RSHIFT_EXPR,
2747 const_binop (LSHIFT_EXPR, tmask,
2748 size_int (precision - size),
2750 size_int (precision - size), 0));
2753 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
2754 represents the sign bit of EXP's type. If EXP represents a sign
2755 or zero extension, also test VAL against the unextended type.
2756 The return value is the (sub)expression whose sign bit is VAL,
2757 or NULL_TREE otherwise. */
2760 sign_bit_p (exp, val)
2764 unsigned HOST_WIDE_INT lo;
2769 /* Tree EXP must have an integral type. */
2770 t = TREE_TYPE (exp);
2771 if (! INTEGRAL_TYPE_P (t))
2774 /* Tree VAL must be an integer constant. */
2775 if (TREE_CODE (val) != INTEGER_CST
2776 || TREE_CONSTANT_OVERFLOW (val))
2779 width = TYPE_PRECISION (t);
2780 if (width > HOST_BITS_PER_WIDE_INT)
2782 hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1);
2788 lo = (unsigned HOST_WIDE_INT) 1 << (width - 1);
2791 if (TREE_INT_CST_HIGH (val) == hi && TREE_INT_CST_LOW (val) == lo)
2794 /* Handle extension from a narrower type. */
2795 if (TREE_CODE (exp) == NOP_EXPR
2796 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width)
2797 return sign_bit_p (TREE_OPERAND (exp, 0), val);
2802 /* Subroutine for fold_truthop: determine if an operand is simple enough
2803 to be evaluated unconditionally. */
2806 simple_operand_p (exp)
2809 /* Strip any conversions that don't change the machine mode. */
2810 while ((TREE_CODE (exp) == NOP_EXPR
2811 || TREE_CODE (exp) == CONVERT_EXPR)
2812 && (TYPE_MODE (TREE_TYPE (exp))
2813 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)))))
2814 exp = TREE_OPERAND (exp, 0);
2816 return (TREE_CODE_CLASS (TREE_CODE (exp)) == 'c'
2818 && ! TREE_ADDRESSABLE (exp)
2819 && ! TREE_THIS_VOLATILE (exp)
2820 && ! DECL_NONLOCAL (exp)
2821 /* Don't regard global variables as simple. They may be
2822 allocated in ways unknown to the compiler (shared memory,
2823 #pragma weak, etc). */
2824 && ! TREE_PUBLIC (exp)
2825 && ! DECL_EXTERNAL (exp)
2826 /* Loading a static variable is unduly expensive, but global
2827 registers aren't expensive. */
2828 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
2831 /* The following functions are subroutines to fold_range_test and allow it to
2832 try to change a logical combination of comparisons into a range test.
2835 X == 2 || X == 3 || X == 4 || X == 5
2839 (unsigned) (X - 2) <= 3
2841 We describe each set of comparisons as being either inside or outside
2842 a range, using a variable named like IN_P, and then describe the
2843 range with a lower and upper bound. If one of the bounds is omitted,
2844 it represents either the highest or lowest value of the type.
2846 In the comments below, we represent a range by two numbers in brackets
2847 preceded by a "+" to designate being inside that range, or a "-" to
2848 designate being outside that range, so the condition can be inverted by
2849 flipping the prefix. An omitted bound is represented by a "-". For
2850 example, "- [-, 10]" means being outside the range starting at the lowest
2851 possible value and ending at 10, in other words, being greater than 10.
2852 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
2855 We set up things so that the missing bounds are handled in a consistent
2856 manner so neither a missing bound nor "true" and "false" need to be
2857 handled using a special case. */
2859 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
2860 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
2861 and UPPER1_P are nonzero if the respective argument is an upper bound
2862 and zero for a lower. TYPE, if nonzero, is the type of the result; it
2863 must be specified for a comparison. ARG1 will be converted to ARG0's
2864 type if both are specified. */
2867 range_binop (code, type, arg0, upper0_p, arg1, upper1_p)
2868 enum tree_code code;
2871 int upper0_p, upper1_p;
2877 /* If neither arg represents infinity, do the normal operation.
2878 Else, if not a comparison, return infinity. Else handle the special
2879 comparison rules. Note that most of the cases below won't occur, but
2880 are handled for consistency. */
2882 if (arg0 != 0 && arg1 != 0)
2884 tem = fold (build (code, type != 0 ? type : TREE_TYPE (arg0),
2885 arg0, convert (TREE_TYPE (arg0), arg1)));
2887 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
2890 if (TREE_CODE_CLASS (code) != '<')
2893 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
2894 for neither. In real maths, we cannot assume open ended ranges are
2895 the same. But, this is computer arithmetic, where numbers are finite.
2896 We can therefore make the transformation of any unbounded range with
2897 the value Z, Z being greater than any representable number. This permits
2898 us to treat unbounded ranges as equal. */
2899 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
2900 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
2904 result = sgn0 == sgn1;
2907 result = sgn0 != sgn1;
2910 result = sgn0 < sgn1;
2913 result = sgn0 <= sgn1;
2916 result = sgn0 > sgn1;
2919 result = sgn0 >= sgn1;
2925 return convert (type, result ? integer_one_node : integer_zero_node);
2928 /* Given EXP, a logical expression, set the range it is testing into
2929 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
2930 actually being tested. *PLOW and *PHIGH will be made of the same type
2931 as the returned expression. If EXP is not a comparison, we will most
2932 likely not be returning a useful value and range. */
2935 make_range (exp, pin_p, plow, phigh)
2940 enum tree_code code;
2941 tree arg0 = NULL_TREE, arg1 = NULL_TREE, type = NULL_TREE;
2942 tree orig_type = NULL_TREE;
2944 tree low, high, n_low, n_high;
2946 /* Start with simply saying "EXP != 0" and then look at the code of EXP
2947 and see if we can refine the range. Some of the cases below may not
2948 happen, but it doesn't seem worth worrying about this. We "continue"
2949 the outer loop when we've changed something; otherwise we "break"
2950 the switch, which will "break" the while. */
2952 in_p = 0, low = high = convert (TREE_TYPE (exp), integer_zero_node);
2956 code = TREE_CODE (exp);
2958 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
2960 arg0 = TREE_OPERAND (exp, 0);
2961 if (TREE_CODE_CLASS (code) == '<'
2962 || TREE_CODE_CLASS (code) == '1'
2963 || TREE_CODE_CLASS (code) == '2')
2964 type = TREE_TYPE (arg0);
2965 if (TREE_CODE_CLASS (code) == '2'
2966 || TREE_CODE_CLASS (code) == '<'
2967 || (TREE_CODE_CLASS (code) == 'e'
2968 && TREE_CODE_LENGTH (code) > 1))
2969 arg1 = TREE_OPERAND (exp, 1);
2972 /* Set ORIG_TYPE as soon as TYPE is non-null so that we do not
2973 lose a cast by accident. */
2974 if (type != NULL_TREE && orig_type == NULL_TREE)
2979 case TRUTH_NOT_EXPR:
2980 in_p = ! in_p, exp = arg0;
2983 case EQ_EXPR: case NE_EXPR:
2984 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
2985 /* We can only do something if the range is testing for zero
2986 and if the second operand is an integer constant. Note that
2987 saying something is "in" the range we make is done by
2988 complementing IN_P since it will set in the initial case of
2989 being not equal to zero; "out" is leaving it alone. */
2990 if (low == 0 || high == 0
2991 || ! integer_zerop (low) || ! integer_zerop (high)
2992 || TREE_CODE (arg1) != INTEGER_CST)
2997 case NE_EXPR: /* - [c, c] */
3000 case EQ_EXPR: /* + [c, c] */
3001 in_p = ! in_p, low = high = arg1;
3003 case GT_EXPR: /* - [-, c] */
3004 low = 0, high = arg1;
3006 case GE_EXPR: /* + [c, -] */
3007 in_p = ! in_p, low = arg1, high = 0;
3009 case LT_EXPR: /* - [c, -] */
3010 low = arg1, high = 0;
3012 case LE_EXPR: /* + [-, c] */
3013 in_p = ! in_p, low = 0, high = arg1;
3021 /* If this is an unsigned comparison, we also know that EXP is
3022 greater than or equal to zero. We base the range tests we make
3023 on that fact, so we record it here so we can parse existing
3025 if (TREE_UNSIGNED (type) && (low == 0 || high == 0))
3027 if (! merge_ranges (&n_in_p, &n_low, &n_high, in_p, low, high,
3028 1, convert (type, integer_zero_node),
3032 in_p = n_in_p, low = n_low, high = n_high;
3034 /* If the high bound is missing, but we
3035 have a low bound, reverse the range so
3036 it goes from zero to the low bound minus 1. */
3037 if (high == 0 && low)
3040 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
3041 integer_one_node, 0);
3042 low = convert (type, integer_zero_node);
3048 /* (-x) IN [a,b] -> x in [-b, -a] */
3049 n_low = range_binop (MINUS_EXPR, type,
3050 convert (type, integer_zero_node), 0, high, 1);
3051 n_high = range_binop (MINUS_EXPR, type,
3052 convert (type, integer_zero_node), 0, low, 0);
3053 low = n_low, high = n_high;
3059 exp = build (MINUS_EXPR, type, negate_expr (arg0),
3060 convert (type, integer_one_node));
3063 case PLUS_EXPR: case MINUS_EXPR:
3064 if (TREE_CODE (arg1) != INTEGER_CST)
3067 /* If EXP is signed, any overflow in the computation is undefined,
3068 so we don't worry about it so long as our computations on
3069 the bounds don't overflow. For unsigned, overflow is defined
3070 and this is exactly the right thing. */
3071 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3072 type, low, 0, arg1, 0);
3073 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3074 type, high, 1, arg1, 0);
3075 if ((n_low != 0 && TREE_OVERFLOW (n_low))
3076 || (n_high != 0 && TREE_OVERFLOW (n_high)))
3079 /* Check for an unsigned range which has wrapped around the maximum
3080 value thus making n_high < n_low, and normalize it. */
3081 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
3083 low = range_binop (PLUS_EXPR, type, n_high, 0,
3084 integer_one_node, 0);
3085 high = range_binop (MINUS_EXPR, type, n_low, 0,
3086 integer_one_node, 0);
3088 /* If the range is of the form +/- [ x+1, x ], we won't
3089 be able to normalize it. But then, it represents the
3090 whole range or the empty set, so make it
3092 if (tree_int_cst_equal (n_low, low)
3093 && tree_int_cst_equal (n_high, high))
3099 low = n_low, high = n_high;
3104 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
3105 if (TYPE_PRECISION (type) > TYPE_PRECISION (orig_type))
3108 if (! INTEGRAL_TYPE_P (type)
3109 || (low != 0 && ! int_fits_type_p (low, type))
3110 || (high != 0 && ! int_fits_type_p (high, type)))
3113 n_low = low, n_high = high;
3116 n_low = convert (type, n_low);
3119 n_high = convert (type, n_high);
3121 /* If we're converting from an unsigned to a signed type,
3122 we will be doing the comparison as unsigned. The tests above
3123 have already verified that LOW and HIGH are both positive.
3125 So we have to make sure that the original unsigned value will
3126 be interpreted as positive. */
3127 if (TREE_UNSIGNED (type) && ! TREE_UNSIGNED (TREE_TYPE (exp)))
3129 tree equiv_type = (*lang_hooks.types.type_for_mode)
3130 (TYPE_MODE (type), 1);
3133 /* A range without an upper bound is, naturally, unbounded.
3134 Since convert would have cropped a very large value, use
3135 the max value for the destination type. */
3137 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
3138 : TYPE_MAX_VALUE (type);
3140 if (TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (exp)))
3141 high_positive = fold (build (RSHIFT_EXPR, type,
3142 convert (type, high_positive),
3143 convert (type, integer_one_node)));
3145 /* If the low bound is specified, "and" the range with the
3146 range for which the original unsigned value will be
3150 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3152 1, convert (type, integer_zero_node),
3156 in_p = (n_in_p == in_p);
3160 /* Otherwise, "or" the range with the range of the input
3161 that will be interpreted as negative. */
3162 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3164 1, convert (type, integer_zero_node),
3168 in_p = (in_p != n_in_p);
3173 low = n_low, high = n_high;
3183 /* If EXP is a constant, we can evaluate whether this is true or false. */
3184 if (TREE_CODE (exp) == INTEGER_CST)
3186 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
3188 && integer_onep (range_binop (LE_EXPR, integer_type_node,
3194 *pin_p = in_p, *plow = low, *phigh = high;
3198 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3199 type, TYPE, return an expression to test if EXP is in (or out of, depending
3200 on IN_P) the range. */
3203 build_range_check (type, exp, in_p, low, high)
3209 tree etype = TREE_TYPE (exp);
3213 && (0 != (value = build_range_check (type, exp, 1, low, high))))
3214 return invert_truthvalue (value);
3216 if (low == 0 && high == 0)
3217 return convert (type, integer_one_node);
3220 return fold (build (LE_EXPR, type, exp, high));
3223 return fold (build (GE_EXPR, type, exp, low));
3225 if (operand_equal_p (low, high, 0))
3226 return fold (build (EQ_EXPR, type, exp, low));
3228 if (integer_zerop (low))
3230 if (! TREE_UNSIGNED (etype))
3232 etype = (*lang_hooks.types.unsigned_type) (etype);
3233 high = convert (etype, high);
3234 exp = convert (etype, exp);
3236 return build_range_check (type, exp, 1, 0, high);
3239 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
3240 if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST)
3242 unsigned HOST_WIDE_INT lo;
3246 prec = TYPE_PRECISION (etype);
3247 if (prec <= HOST_BITS_PER_WIDE_INT)
3250 lo = ((unsigned HOST_WIDE_INT) 1 << (prec - 1)) - 1;
3254 hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1;
3255 lo = (unsigned HOST_WIDE_INT) -1;
3258 if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo)
3260 if (TREE_UNSIGNED (etype))
3262 etype = (*lang_hooks.types.signed_type) (etype);
3263 exp = convert (etype, exp);
3265 return fold (build (GT_EXPR, type, exp,
3266 convert (etype, integer_zero_node)));
3270 if (0 != (value = const_binop (MINUS_EXPR, high, low, 0))
3271 && ! TREE_OVERFLOW (value))
3272 return build_range_check (type,
3273 fold (build (MINUS_EXPR, etype, exp, low)),
3274 1, convert (etype, integer_zero_node), value);
3279 /* Given two ranges, see if we can merge them into one. Return 1 if we
3280 can, 0 if we can't. Set the output range into the specified parameters. */
3283 merge_ranges (pin_p, plow, phigh, in0_p, low0, high0, in1_p, low1, high1)
3287 tree low0, high0, low1, high1;
3295 int lowequal = ((low0 == 0 && low1 == 0)
3296 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3297 low0, 0, low1, 0)));
3298 int highequal = ((high0 == 0 && high1 == 0)
3299 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3300 high0, 1, high1, 1)));
3302 /* Make range 0 be the range that starts first, or ends last if they
3303 start at the same value. Swap them if it isn't. */
3304 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
3307 && integer_onep (range_binop (GT_EXPR, integer_type_node,
3308 high1, 1, high0, 1))))
3310 temp = in0_p, in0_p = in1_p, in1_p = temp;
3311 tem = low0, low0 = low1, low1 = tem;
3312 tem = high0, high0 = high1, high1 = tem;
3315 /* Now flag two cases, whether the ranges are disjoint or whether the
3316 second range is totally subsumed in the first. Note that the tests
3317 below are simplified by the ones above. */
3318 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
3319 high0, 1, low1, 0));
3320 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
3321 high1, 1, high0, 1));
3323 /* We now have four cases, depending on whether we are including or
3324 excluding the two ranges. */
3327 /* If they don't overlap, the result is false. If the second range
3328 is a subset it is the result. Otherwise, the range is from the start
3329 of the second to the end of the first. */
3331 in_p = 0, low = high = 0;
3333 in_p = 1, low = low1, high = high1;
3335 in_p = 1, low = low1, high = high0;
3338 else if (in0_p && ! in1_p)
3340 /* If they don't overlap, the result is the first range. If they are
3341 equal, the result is false. If the second range is a subset of the
3342 first, and the ranges begin at the same place, we go from just after
3343 the end of the first range to the end of the second. If the second
3344 range is not a subset of the first, or if it is a subset and both
3345 ranges end at the same place, the range starts at the start of the
3346 first range and ends just before the second range.
3347 Otherwise, we can't describe this as a single range. */
3349 in_p = 1, low = low0, high = high0;
3350 else if (lowequal && highequal)
3351 in_p = 0, low = high = 0;
3352 else if (subset && lowequal)
3354 in_p = 1, high = high0;
3355 low = range_binop (PLUS_EXPR, NULL_TREE, high1, 0,
3356 integer_one_node, 0);
3358 else if (! subset || highequal)
3360 in_p = 1, low = low0;
3361 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
3362 integer_one_node, 0);
3368 else if (! in0_p && in1_p)
3370 /* If they don't overlap, the result is the second range. If the second
3371 is a subset of the first, the result is false. Otherwise,
3372 the range starts just after the first range and ends at the
3373 end of the second. */
3375 in_p = 1, low = low1, high = high1;
3376 else if (subset || highequal)
3377 in_p = 0, low = high = 0;
3380 in_p = 1, high = high1;
3381 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
3382 integer_one_node, 0);
3388 /* The case where we are excluding both ranges. Here the complex case
3389 is if they don't overlap. In that case, the only time we have a
3390 range is if they are adjacent. If the second is a subset of the
3391 first, the result is the first. Otherwise, the range to exclude
3392 starts at the beginning of the first range and ends at the end of the
3396 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
3397 range_binop (PLUS_EXPR, NULL_TREE,
3399 integer_one_node, 1),
3401 in_p = 0, low = low0, high = high1;
3406 in_p = 0, low = low0, high = high0;
3408 in_p = 0, low = low0, high = high1;
3411 *pin_p = in_p, *plow = low, *phigh = high;
3415 /* EXP is some logical combination of boolean tests. See if we can
3416 merge it into some range test. Return the new tree if so. */
3419 fold_range_test (exp)
3422 int or_op = (TREE_CODE (exp) == TRUTH_ORIF_EXPR
3423 || TREE_CODE (exp) == TRUTH_OR_EXPR);
3424 int in0_p, in1_p, in_p;
3425 tree low0, low1, low, high0, high1, high;
3426 tree lhs = make_range (TREE_OPERAND (exp, 0), &in0_p, &low0, &high0);
3427 tree rhs = make_range (TREE_OPERAND (exp, 1), &in1_p, &low1, &high1);
3430 /* If this is an OR operation, invert both sides; we will invert
3431 again at the end. */
3433 in0_p = ! in0_p, in1_p = ! in1_p;
3435 /* If both expressions are the same, if we can merge the ranges, and we
3436 can build the range test, return it or it inverted. If one of the
3437 ranges is always true or always false, consider it to be the same
3438 expression as the other. */
3439 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
3440 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
3442 && 0 != (tem = (build_range_check (TREE_TYPE (exp),
3444 : rhs != 0 ? rhs : integer_zero_node,
3446 return or_op ? invert_truthvalue (tem) : tem;
3448 /* On machines where the branch cost is expensive, if this is a
3449 short-circuited branch and the underlying object on both sides
3450 is the same, make a non-short-circuit operation. */
3451 else if (BRANCH_COST >= 2
3452 && lhs != 0 && rhs != 0
3453 && (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3454 || TREE_CODE (exp) == TRUTH_ORIF_EXPR)
3455 && operand_equal_p (lhs, rhs, 0))
3457 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
3458 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
3459 which cases we can't do this. */
3460 if (simple_operand_p (lhs))
3461 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3462 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3463 TREE_TYPE (exp), TREE_OPERAND (exp, 0),
3464 TREE_OPERAND (exp, 1));
3466 else if ((*lang_hooks.decls.global_bindings_p) () == 0
3467 && ! contains_placeholder_p (lhs))
3469 tree common = save_expr (lhs);
3471 if (0 != (lhs = build_range_check (TREE_TYPE (exp), common,
3472 or_op ? ! in0_p : in0_p,
3474 && (0 != (rhs = build_range_check (TREE_TYPE (exp), common,
3475 or_op ? ! in1_p : in1_p,
3477 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3478 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3479 TREE_TYPE (exp), lhs, rhs);
3486 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
3487 bit value. Arrange things so the extra bits will be set to zero if and
3488 only if C is signed-extended to its full width. If MASK is nonzero,
3489 it is an INTEGER_CST that should be AND'ed with the extra bits. */
3492 unextend (c, p, unsignedp, mask)
3498 tree type = TREE_TYPE (c);
3499 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
3502 if (p == modesize || unsignedp)
3505 /* We work by getting just the sign bit into the low-order bit, then
3506 into the high-order bit, then sign-extend. We then XOR that value
3508 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
3509 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
3511 /* We must use a signed type in order to get an arithmetic right shift.
3512 However, we must also avoid introducing accidental overflows, so that
3513 a subsequent call to integer_zerop will work. Hence we must
3514 do the type conversion here. At this point, the constant is either
3515 zero or one, and the conversion to a signed type can never overflow.
3516 We could get an overflow if this conversion is done anywhere else. */
3517 if (TREE_UNSIGNED (type))
3518 temp = convert ((*lang_hooks.types.signed_type) (type), temp);
3520 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
3521 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
3523 temp = const_binop (BIT_AND_EXPR, temp, convert (TREE_TYPE (c), mask), 0);
3524 /* If necessary, convert the type back to match the type of C. */
3525 if (TREE_UNSIGNED (type))
3526 temp = convert (type, temp);
3528 return convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
3531 /* Find ways of folding logical expressions of LHS and RHS:
3532 Try to merge two comparisons to the same innermost item.
3533 Look for range tests like "ch >= '0' && ch <= '9'".
3534 Look for combinations of simple terms on machines with expensive branches
3535 and evaluate the RHS unconditionally.
3537 For example, if we have p->a == 2 && p->b == 4 and we can make an
3538 object large enough to span both A and B, we can do this with a comparison
3539 against the object ANDed with the a mask.
3541 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
3542 operations to do this with one comparison.
3544 We check for both normal comparisons and the BIT_AND_EXPRs made this by
3545 function and the one above.
3547 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
3548 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
3550 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
3553 We return the simplified tree or 0 if no optimization is possible. */
3556 fold_truthop (code, truth_type, lhs, rhs)
3557 enum tree_code code;
3558 tree truth_type, lhs, rhs;
3560 /* If this is the "or" of two comparisons, we can do something if
3561 the comparisons are NE_EXPR. If this is the "and", we can do something
3562 if the comparisons are EQ_EXPR. I.e.,
3563 (a->b == 2 && a->c == 4) can become (a->new == NEW).
3565 WANTED_CODE is this operation code. For single bit fields, we can
3566 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
3567 comparison for one-bit fields. */
3569 enum tree_code wanted_code;
3570 enum tree_code lcode, rcode;
3571 tree ll_arg, lr_arg, rl_arg, rr_arg;
3572 tree ll_inner, lr_inner, rl_inner, rr_inner;
3573 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
3574 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
3575 HOST_WIDE_INT xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
3576 HOST_WIDE_INT lnbitsize, lnbitpos, rnbitsize, rnbitpos;
3577 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
3578 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
3579 enum machine_mode lnmode, rnmode;
3580 tree ll_mask, lr_mask, rl_mask, rr_mask;
3581 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
3582 tree l_const, r_const;
3583 tree lntype, rntype, result;
3584 int first_bit, end_bit;
3587 /* Start by getting the comparison codes. Fail if anything is volatile.
3588 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
3589 it were surrounded with a NE_EXPR. */
3591 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
3594 lcode = TREE_CODE (lhs);
3595 rcode = TREE_CODE (rhs);
3597 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
3598 lcode = NE_EXPR, lhs = build (NE_EXPR, truth_type, lhs, integer_zero_node);
3600 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
3601 rcode = NE_EXPR, rhs = build (NE_EXPR, truth_type, rhs, integer_zero_node);
3603 if (TREE_CODE_CLASS (lcode) != '<' || TREE_CODE_CLASS (rcode) != '<')
3606 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
3607 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
3609 ll_arg = TREE_OPERAND (lhs, 0);
3610 lr_arg = TREE_OPERAND (lhs, 1);
3611 rl_arg = TREE_OPERAND (rhs, 0);
3612 rr_arg = TREE_OPERAND (rhs, 1);
3614 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
3615 if (simple_operand_p (ll_arg)
3616 && simple_operand_p (lr_arg)
3617 && !FLOAT_TYPE_P (TREE_TYPE (ll_arg)))
3621 if (operand_equal_p (ll_arg, rl_arg, 0)
3622 && operand_equal_p (lr_arg, rr_arg, 0))
3624 int lcompcode, rcompcode;
3626 lcompcode = comparison_to_compcode (lcode);
3627 rcompcode = comparison_to_compcode (rcode);
3628 compcode = (code == TRUTH_AND_EXPR)
3629 ? lcompcode & rcompcode
3630 : lcompcode | rcompcode;
3632 else if (operand_equal_p (ll_arg, rr_arg, 0)
3633 && operand_equal_p (lr_arg, rl_arg, 0))
3635 int lcompcode, rcompcode;
3637 rcode = swap_tree_comparison (rcode);
3638 lcompcode = comparison_to_compcode (lcode);
3639 rcompcode = comparison_to_compcode (rcode);
3640 compcode = (code == TRUTH_AND_EXPR)
3641 ? lcompcode & rcompcode
3642 : lcompcode | rcompcode;
3647 if (compcode == COMPCODE_TRUE)
3648 return convert (truth_type, integer_one_node);
3649 else if (compcode == COMPCODE_FALSE)
3650 return convert (truth_type, integer_zero_node);
3651 else if (compcode != -1)
3652 return build (compcode_to_comparison (compcode),
3653 truth_type, ll_arg, lr_arg);
3656 /* If the RHS can be evaluated unconditionally and its operands are
3657 simple, it wins to evaluate the RHS unconditionally on machines
3658 with expensive branches. In this case, this isn't a comparison
3659 that can be merged. Avoid doing this if the RHS is a floating-point
3660 comparison since those can trap. */
3662 if (BRANCH_COST >= 2
3663 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
3664 && simple_operand_p (rl_arg)
3665 && simple_operand_p (rr_arg))
3667 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
3668 if (code == TRUTH_OR_EXPR
3669 && lcode == NE_EXPR && integer_zerop (lr_arg)
3670 && rcode == NE_EXPR && integer_zerop (rr_arg)
3671 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
3672 return build (NE_EXPR, truth_type,
3673 build (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
3677 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
3678 if (code == TRUTH_AND_EXPR
3679 && lcode == EQ_EXPR && integer_zerop (lr_arg)
3680 && rcode == EQ_EXPR && integer_zerop (rr_arg)
3681 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
3682 return build (EQ_EXPR, truth_type,
3683 build (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
3687 return build (code, truth_type, lhs, rhs);
3690 /* See if the comparisons can be merged. Then get all the parameters for
3693 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
3694 || (rcode != EQ_EXPR && rcode != NE_EXPR))
3698 ll_inner = decode_field_reference (ll_arg,
3699 &ll_bitsize, &ll_bitpos, &ll_mode,
3700 &ll_unsignedp, &volatilep, &ll_mask,
3702 lr_inner = decode_field_reference (lr_arg,
3703 &lr_bitsize, &lr_bitpos, &lr_mode,
3704 &lr_unsignedp, &volatilep, &lr_mask,
3706 rl_inner = decode_field_reference (rl_arg,
3707 &rl_bitsize, &rl_bitpos, &rl_mode,
3708 &rl_unsignedp, &volatilep, &rl_mask,
3710 rr_inner = decode_field_reference (rr_arg,
3711 &rr_bitsize, &rr_bitpos, &rr_mode,
3712 &rr_unsignedp, &volatilep, &rr_mask,
3715 /* It must be true that the inner operation on the lhs of each
3716 comparison must be the same if we are to be able to do anything.
3717 Then see if we have constants. If not, the same must be true for
3719 if (volatilep || ll_inner == 0 || rl_inner == 0
3720 || ! operand_equal_p (ll_inner, rl_inner, 0))
3723 if (TREE_CODE (lr_arg) == INTEGER_CST
3724 && TREE_CODE (rr_arg) == INTEGER_CST)
3725 l_const = lr_arg, r_const = rr_arg;
3726 else if (lr_inner == 0 || rr_inner == 0
3727 || ! operand_equal_p (lr_inner, rr_inner, 0))
3730 l_const = r_const = 0;
3732 /* If either comparison code is not correct for our logical operation,
3733 fail. However, we can convert a one-bit comparison against zero into
3734 the opposite comparison against that bit being set in the field. */
3736 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
3737 if (lcode != wanted_code)
3739 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
3741 /* Make the left operand unsigned, since we are only interested
3742 in the value of one bit. Otherwise we are doing the wrong
3751 /* This is analogous to the code for l_const above. */
3752 if (rcode != wanted_code)
3754 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
3763 /* After this point all optimizations will generate bit-field
3764 references, which we might not want. */
3765 if (! (*lang_hooks.can_use_bit_fields_p) ())
3768 /* See if we can find a mode that contains both fields being compared on
3769 the left. If we can't, fail. Otherwise, update all constants and masks
3770 to be relative to a field of that size. */
3771 first_bit = MIN (ll_bitpos, rl_bitpos);
3772 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
3773 lnmode = get_best_mode (end_bit - first_bit, first_bit,
3774 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
3776 if (lnmode == VOIDmode)
3779 lnbitsize = GET_MODE_BITSIZE (lnmode);
3780 lnbitpos = first_bit & ~ (lnbitsize - 1);
3781 lntype = (*lang_hooks.types.type_for_size) (lnbitsize, 1);
3782 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
3784 if (BYTES_BIG_ENDIAN)
3786 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
3787 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
3790 ll_mask = const_binop (LSHIFT_EXPR, convert (lntype, ll_mask),
3791 size_int (xll_bitpos), 0);
3792 rl_mask = const_binop (LSHIFT_EXPR, convert (lntype, rl_mask),
3793 size_int (xrl_bitpos), 0);
3797 l_const = convert (lntype, l_const);
3798 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
3799 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
3800 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
3801 fold (build1 (BIT_NOT_EXPR,
3805 warning ("comparison is always %d", wanted_code == NE_EXPR);
3807 return convert (truth_type,
3808 wanted_code == NE_EXPR
3809 ? integer_one_node : integer_zero_node);
3814 r_const = convert (lntype, r_const);
3815 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
3816 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
3817 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
3818 fold (build1 (BIT_NOT_EXPR,
3822 warning ("comparison is always %d", wanted_code == NE_EXPR);
3824 return convert (truth_type,
3825 wanted_code == NE_EXPR
3826 ? integer_one_node : integer_zero_node);
3830 /* If the right sides are not constant, do the same for it. Also,
3831 disallow this optimization if a size or signedness mismatch occurs
3832 between the left and right sides. */
3835 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
3836 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
3837 /* Make sure the two fields on the right
3838 correspond to the left without being swapped. */
3839 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
3842 first_bit = MIN (lr_bitpos, rr_bitpos);
3843 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
3844 rnmode = get_best_mode (end_bit - first_bit, first_bit,
3845 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
3847 if (rnmode == VOIDmode)
3850 rnbitsize = GET_MODE_BITSIZE (rnmode);
3851 rnbitpos = first_bit & ~ (rnbitsize - 1);
3852 rntype = (*lang_hooks.types.type_for_size) (rnbitsize, 1);
3853 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
3855 if (BYTES_BIG_ENDIAN)
3857 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
3858 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
3861 lr_mask = const_binop (LSHIFT_EXPR, convert (rntype, lr_mask),
3862 size_int (xlr_bitpos), 0);
3863 rr_mask = const_binop (LSHIFT_EXPR, convert (rntype, rr_mask),
3864 size_int (xrr_bitpos), 0);
3866 /* Make a mask that corresponds to both fields being compared.
3867 Do this for both items being compared. If the operands are the
3868 same size and the bits being compared are in the same position
3869 then we can do this by masking both and comparing the masked
3871 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
3872 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
3873 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
3875 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
3876 ll_unsignedp || rl_unsignedp);
3877 if (! all_ones_mask_p (ll_mask, lnbitsize))
3878 lhs = build (BIT_AND_EXPR, lntype, lhs, ll_mask);
3880 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
3881 lr_unsignedp || rr_unsignedp);
3882 if (! all_ones_mask_p (lr_mask, rnbitsize))
3883 rhs = build (BIT_AND_EXPR, rntype, rhs, lr_mask);
3885 return build (wanted_code, truth_type, lhs, rhs);
3888 /* There is still another way we can do something: If both pairs of
3889 fields being compared are adjacent, we may be able to make a wider
3890 field containing them both.
3892 Note that we still must mask the lhs/rhs expressions. Furthermore,
3893 the mask must be shifted to account for the shift done by
3894 make_bit_field_ref. */
3895 if ((ll_bitsize + ll_bitpos == rl_bitpos
3896 && lr_bitsize + lr_bitpos == rr_bitpos)
3897 || (ll_bitpos == rl_bitpos + rl_bitsize
3898 && lr_bitpos == rr_bitpos + rr_bitsize))
3902 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
3903 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
3904 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
3905 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
3907 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
3908 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
3909 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
3910 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
3912 /* Convert to the smaller type before masking out unwanted bits. */
3914 if (lntype != rntype)
3916 if (lnbitsize > rnbitsize)
3918 lhs = convert (rntype, lhs);
3919 ll_mask = convert (rntype, ll_mask);
3922 else if (lnbitsize < rnbitsize)
3924 rhs = convert (lntype, rhs);
3925 lr_mask = convert (lntype, lr_mask);
3930 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
3931 lhs = build (BIT_AND_EXPR, type, lhs, ll_mask);
3933 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
3934 rhs = build (BIT_AND_EXPR, type, rhs, lr_mask);
3936 return build (wanted_code, truth_type, lhs, rhs);
3942 /* Handle the case of comparisons with constants. If there is something in
3943 common between the masks, those bits of the constants must be the same.
3944 If not, the condition is always false. Test for this to avoid generating
3945 incorrect code below. */
3946 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
3947 if (! integer_zerop (result)
3948 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
3949 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
3951 if (wanted_code == NE_EXPR)
3953 warning ("`or' of unmatched not-equal tests is always 1");
3954 return convert (truth_type, integer_one_node);
3958 warning ("`and' of mutually exclusive equal-tests is always 0");
3959 return convert (truth_type, integer_zero_node);
3963 /* Construct the expression we will return. First get the component
3964 reference we will make. Unless the mask is all ones the width of
3965 that field, perform the mask operation. Then compare with the
3967 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
3968 ll_unsignedp || rl_unsignedp);
3970 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
3971 if (! all_ones_mask_p (ll_mask, lnbitsize))
3972 result = build (BIT_AND_EXPR, lntype, result, ll_mask);
3974 return build (wanted_code, truth_type, result,
3975 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
3978 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
3982 optimize_minmax_comparison (t)
3985 tree type = TREE_TYPE (t);
3986 tree arg0 = TREE_OPERAND (t, 0);
3987 enum tree_code op_code;
3988 tree comp_const = TREE_OPERAND (t, 1);
3990 int consts_equal, consts_lt;
3993 STRIP_SIGN_NOPS (arg0);
3995 op_code = TREE_CODE (arg0);
3996 minmax_const = TREE_OPERAND (arg0, 1);
3997 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
3998 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
3999 inner = TREE_OPERAND (arg0, 0);
4001 /* If something does not permit us to optimize, return the original tree. */
4002 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
4003 || TREE_CODE (comp_const) != INTEGER_CST
4004 || TREE_CONSTANT_OVERFLOW (comp_const)
4005 || TREE_CODE (minmax_const) != INTEGER_CST
4006 || TREE_CONSTANT_OVERFLOW (minmax_const))
4009 /* Now handle all the various comparison codes. We only handle EQ_EXPR
4010 and GT_EXPR, doing the rest with recursive calls using logical
4012 switch (TREE_CODE (t))
4014 case NE_EXPR: case LT_EXPR: case LE_EXPR:
4016 invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t)));
4020 fold (build (TRUTH_ORIF_EXPR, type,
4021 optimize_minmax_comparison
4022 (build (EQ_EXPR, type, arg0, comp_const)),
4023 optimize_minmax_comparison
4024 (build (GT_EXPR, type, arg0, comp_const))));
4027 if (op_code == MAX_EXPR && consts_equal)
4028 /* MAX (X, 0) == 0 -> X <= 0 */
4029 return fold (build (LE_EXPR, type, inner, comp_const));
4031 else if (op_code == MAX_EXPR && consts_lt)
4032 /* MAX (X, 0) == 5 -> X == 5 */
4033 return fold (build (EQ_EXPR, type, inner, comp_const));
4035 else if (op_code == MAX_EXPR)
4036 /* MAX (X, 0) == -1 -> false */
4037 return omit_one_operand (type, integer_zero_node, inner);
4039 else if (consts_equal)
4040 /* MIN (X, 0) == 0 -> X >= 0 */
4041 return fold (build (GE_EXPR, type, inner, comp_const));
4044 /* MIN (X, 0) == 5 -> false */
4045 return omit_one_operand (type, integer_zero_node, inner);
4048 /* MIN (X, 0) == -1 -> X == -1 */
4049 return fold (build (EQ_EXPR, type, inner, comp_const));
4052 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
4053 /* MAX (X, 0) > 0 -> X > 0
4054 MAX (X, 0) > 5 -> X > 5 */
4055 return fold (build (GT_EXPR, type, inner, comp_const));
4057 else if (op_code == MAX_EXPR)
4058 /* MAX (X, 0) > -1 -> true */
4059 return omit_one_operand (type, integer_one_node, inner);
4061 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
4062 /* MIN (X, 0) > 0 -> false
4063 MIN (X, 0) > 5 -> false */
4064 return omit_one_operand (type, integer_zero_node, inner);
4067 /* MIN (X, 0) > -1 -> X > -1 */
4068 return fold (build (GT_EXPR, type, inner, comp_const));
4075 /* T is an integer expression that is being multiplied, divided, or taken a
4076 modulus (CODE says which and what kind of divide or modulus) by a
4077 constant C. See if we can eliminate that operation by folding it with
4078 other operations already in T. WIDE_TYPE, if non-null, is a type that
4079 should be used for the computation if wider than our type.
4081 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
4082 (X * 2) + (Y * 4). We must, however, be assured that either the original
4083 expression would not overflow or that overflow is undefined for the type
4084 in the language in question.
4086 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
4087 the machine has a multiply-accumulate insn or that this is part of an
4088 addressing calculation.
4090 If we return a non-null expression, it is an equivalent form of the
4091 original computation, but need not be in the original type. */
4094 extract_muldiv (t, c, code, wide_type)
4097 enum tree_code code;
4100 /* To avoid exponential search depth, refuse to allow recursion past
4101 three levels. Beyond that (1) it's highly unlikely that we'll find
4102 something interesting and (2) we've probably processed it before
4103 when we built the inner expression. */
4112 ret = extract_muldiv_1 (t, c, code, wide_type);
4119 extract_muldiv_1 (t, c, code, wide_type)
4122 enum tree_code code;
4125 tree type = TREE_TYPE (t);
4126 enum tree_code tcode = TREE_CODE (t);
4127 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
4128 > GET_MODE_SIZE (TYPE_MODE (type)))
4129 ? wide_type : type);
4131 int same_p = tcode == code;
4132 tree op0 = NULL_TREE, op1 = NULL_TREE;
4134 /* Don't deal with constants of zero here; they confuse the code below. */
4135 if (integer_zerop (c))
4138 if (TREE_CODE_CLASS (tcode) == '1')
4139 op0 = TREE_OPERAND (t, 0);
4141 if (TREE_CODE_CLASS (tcode) == '2')
4142 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
4144 /* Note that we need not handle conditional operations here since fold
4145 already handles those cases. So just do arithmetic here. */
4149 /* For a constant, we can always simplify if we are a multiply
4150 or (for divide and modulus) if it is a multiple of our constant. */
4151 if (code == MULT_EXPR
4152 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
4153 return const_binop (code, convert (ctype, t), convert (ctype, c), 0);
4156 case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
4157 /* If op0 is an expression ... */
4158 if ((TREE_CODE_CLASS (TREE_CODE (op0)) == '<'
4159 || TREE_CODE_CLASS (TREE_CODE (op0)) == '1'
4160 || TREE_CODE_CLASS (TREE_CODE (op0)) == '2'
4161 || TREE_CODE_CLASS (TREE_CODE (op0)) == 'e')
4162 /* ... and is unsigned, and its type is smaller than ctype,
4163 then we cannot pass through as widening. */
4164 && ((TREE_UNSIGNED (TREE_TYPE (op0))
4165 && ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
4166 && TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
4167 && (GET_MODE_SIZE (TYPE_MODE (ctype))
4168 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
4169 /* ... or its type is larger than ctype,
4170 then we cannot pass through this truncation. */
4171 || (GET_MODE_SIZE (TYPE_MODE (ctype))
4172 < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0))))))
4175 /* Pass the constant down and see if we can make a simplification. If
4176 we can, replace this expression with the inner simplification for
4177 possible later conversion to our or some other type. */
4178 if (0 != (t1 = extract_muldiv (op0, convert (TREE_TYPE (op0), c), code,
4179 code == MULT_EXPR ? ctype : NULL_TREE)))
4183 case NEGATE_EXPR: case ABS_EXPR:
4184 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4185 return fold (build1 (tcode, ctype, convert (ctype, t1)));
4188 case MIN_EXPR: case MAX_EXPR:
4189 /* If widening the type changes the signedness, then we can't perform
4190 this optimization as that changes the result. */
4191 if (TREE_UNSIGNED (ctype) != TREE_UNSIGNED (type))
4194 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
4195 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0
4196 && (t2 = extract_muldiv (op1, c, code, wide_type)) != 0)
4198 if (tree_int_cst_sgn (c) < 0)
4199 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
4201 return fold (build (tcode, ctype, convert (ctype, t1),
4202 convert (ctype, t2)));
4206 case WITH_RECORD_EXPR:
4207 if ((t1 = extract_muldiv (TREE_OPERAND (t, 0), c, code, wide_type)) != 0)
4208 return build (WITH_RECORD_EXPR, TREE_TYPE (t1), t1,
4209 TREE_OPERAND (t, 1));
4213 /* If this has not been evaluated and the operand has no side effects,
4214 we can see if we can do something inside it and make a new one.
4215 Note that this test is overly conservative since we can do this
4216 if the only reason it had side effects is that it was another
4217 similar SAVE_EXPR, but that isn't worth bothering with. */
4218 if (SAVE_EXPR_RTL (t) == 0 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0))
4219 && 0 != (t1 = extract_muldiv (TREE_OPERAND (t, 0), c, code,
4222 t1 = save_expr (t1);
4223 if (SAVE_EXPR_PERSISTENT_P (t) && TREE_CODE (t1) == SAVE_EXPR)
4224 SAVE_EXPR_PERSISTENT_P (t1) = 1;
4225 if (is_pending_size (t))
4226 put_pending_size (t1);
4231 case LSHIFT_EXPR: case RSHIFT_EXPR:
4232 /* If the second operand is constant, this is a multiplication
4233 or floor division, by a power of two, so we can treat it that
4234 way unless the multiplier or divisor overflows. */
4235 if (TREE_CODE (op1) == INTEGER_CST
4236 /* const_binop may not detect overflow correctly,
4237 so check for it explicitly here. */
4238 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
4239 && TREE_INT_CST_HIGH (op1) == 0
4240 && 0 != (t1 = convert (ctype,
4241 const_binop (LSHIFT_EXPR, size_one_node,
4243 && ! TREE_OVERFLOW (t1))
4244 return extract_muldiv (build (tcode == LSHIFT_EXPR
4245 ? MULT_EXPR : FLOOR_DIV_EXPR,
4246 ctype, convert (ctype, op0), t1),
4247 c, code, wide_type);
4250 case PLUS_EXPR: case MINUS_EXPR:
4251 /* See if we can eliminate the operation on both sides. If we can, we
4252 can return a new PLUS or MINUS. If we can't, the only remaining
4253 cases where we can do anything are if the second operand is a
4255 t1 = extract_muldiv (op0, c, code, wide_type);
4256 t2 = extract_muldiv (op1, c, code, wide_type);
4257 if (t1 != 0 && t2 != 0
4258 && (code == MULT_EXPR
4259 /* If not multiplication, we can only do this if both operands
4260 are divisible by c. */
4261 || (multiple_of_p (ctype, op0, c)
4262 && multiple_of_p (ctype, op1, c))))
4263 return fold (build (tcode, ctype, convert (ctype, t1),
4264 convert (ctype, t2)));
4266 /* If this was a subtraction, negate OP1 and set it to be an addition.
4267 This simplifies the logic below. */
4268 if (tcode == MINUS_EXPR)
4269 tcode = PLUS_EXPR, op1 = negate_expr (op1);
4271 if (TREE_CODE (op1) != INTEGER_CST)
4274 /* If either OP1 or C are negative, this optimization is not safe for
4275 some of the division and remainder types while for others we need
4276 to change the code. */
4277 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
4279 if (code == CEIL_DIV_EXPR)
4280 code = FLOOR_DIV_EXPR;
4281 else if (code == FLOOR_DIV_EXPR)
4282 code = CEIL_DIV_EXPR;
4283 else if (code != MULT_EXPR
4284 && code != CEIL_MOD_EXPR && code != FLOOR_MOD_EXPR)
4288 /* If it's a multiply or a division/modulus operation of a multiple
4289 of our constant, do the operation and verify it doesn't overflow. */
4290 if (code == MULT_EXPR
4291 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4293 op1 = const_binop (code, convert (ctype, op1), convert (ctype, c), 0);
4294 if (op1 == 0 || TREE_OVERFLOW (op1))
4300 /* If we have an unsigned type is not a sizetype, we cannot widen
4301 the operation since it will change the result if the original
4302 computation overflowed. */
4303 if (TREE_UNSIGNED (ctype)
4304 && ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
4308 /* If we were able to eliminate our operation from the first side,
4309 apply our operation to the second side and reform the PLUS. */
4310 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
4311 return fold (build (tcode, ctype, convert (ctype, t1), op1));
4313 /* The last case is if we are a multiply. In that case, we can
4314 apply the distributive law to commute the multiply and addition
4315 if the multiplication of the constants doesn't overflow. */
4316 if (code == MULT_EXPR)
4317 return fold (build (tcode, ctype, fold (build (code, ctype,
4318 convert (ctype, op0),
4319 convert (ctype, c))),
4325 /* We have a special case here if we are doing something like
4326 (C * 8) % 4 since we know that's zero. */
4327 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
4328 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
4329 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
4330 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4331 return omit_one_operand (type, integer_zero_node, op0);
4333 /* Arrange for the code below to simplify two constants first. */
4334 if (TREE_CODE (op1) == INTEGER_CST && TREE_CODE (op0) != INTEGER_CST)
4341 /* ... fall through ... */
4343 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
4344 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
4345 /* If we can extract our operation from the LHS, do so and return a
4346 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
4347 do something only if the second operand is a constant. */
4349 && (t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4350 return fold (build (tcode, ctype, convert (ctype, t1),
4351 convert (ctype, op1)));
4352 else if (tcode == MULT_EXPR && code == MULT_EXPR
4353 && (t1 = extract_muldiv (op1, c, code, wide_type)) != 0)
4354 return fold (build (tcode, ctype, convert (ctype, op0),
4355 convert (ctype, t1)));
4356 else if (TREE_CODE (op1) != INTEGER_CST)
4359 /* If these are the same operation types, we can associate them
4360 assuming no overflow. */
4362 && 0 != (t1 = const_binop (MULT_EXPR, convert (ctype, op1),
4363 convert (ctype, c), 0))
4364 && ! TREE_OVERFLOW (t1))
4365 return fold (build (tcode, ctype, convert (ctype, op0), t1));
4367 /* If these operations "cancel" each other, we have the main
4368 optimizations of this pass, which occur when either constant is a
4369 multiple of the other, in which case we replace this with either an
4370 operation or CODE or TCODE.
4372 If we have an unsigned type that is not a sizetype, we cannot do
4373 this since it will change the result if the original computation
4375 if ((! TREE_UNSIGNED (ctype)
4376 || (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
4377 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
4378 || (tcode == MULT_EXPR
4379 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
4380 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR)))
4382 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4383 return fold (build (tcode, ctype, convert (ctype, op0),
4385 const_binop (TRUNC_DIV_EXPR,
4387 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
4388 return fold (build (code, ctype, convert (ctype, op0),
4390 const_binop (TRUNC_DIV_EXPR,
4402 /* If T contains a COMPOUND_EXPR which was inserted merely to evaluate
4403 S, a SAVE_EXPR, return the expression actually being evaluated. Note
4404 that we may sometimes modify the tree. */
4407 strip_compound_expr (t, s)
4411 enum tree_code code = TREE_CODE (t);
4413 /* See if this is the COMPOUND_EXPR we want to eliminate. */
4414 if (code == COMPOUND_EXPR && TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR
4415 && TREE_OPERAND (TREE_OPERAND (t, 0), 0) == s)
4416 return TREE_OPERAND (t, 1);
4418 /* See if this is a COND_EXPR or a simple arithmetic operator. We
4419 don't bother handling any other types. */
4420 else if (code == COND_EXPR)
4422 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4423 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4424 TREE_OPERAND (t, 2) = strip_compound_expr (TREE_OPERAND (t, 2), s);
4426 else if (TREE_CODE_CLASS (code) == '1')
4427 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4428 else if (TREE_CODE_CLASS (code) == '<'
4429 || TREE_CODE_CLASS (code) == '2')
4431 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4432 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4438 /* Return a node which has the indicated constant VALUE (either 0 or
4439 1), and is of the indicated TYPE. */
4442 constant_boolean_node (value, type)
4446 if (type == integer_type_node)
4447 return value ? integer_one_node : integer_zero_node;
4448 else if (TREE_CODE (type) == BOOLEAN_TYPE)
4449 return (*lang_hooks.truthvalue_conversion) (value ? integer_one_node :
4453 tree t = build_int_2 (value, 0);
4455 TREE_TYPE (t) = type;
4460 /* Utility function for the following routine, to see how complex a nesting of
4461 COND_EXPRs can be. EXPR is the expression and LIMIT is a count beyond which
4462 we don't care (to avoid spending too much time on complex expressions.). */
4465 count_cond (expr, lim)
4471 if (TREE_CODE (expr) != COND_EXPR)
4476 ctrue = count_cond (TREE_OPERAND (expr, 1), lim - 1);
4477 cfalse = count_cond (TREE_OPERAND (expr, 2), lim - 1 - ctrue);
4478 return MIN (lim, 1 + ctrue + cfalse);
4481 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
4482 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
4483 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
4484 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
4485 COND is the first argument to CODE; otherwise (as in the example
4486 given here), it is the second argument. TYPE is the type of the
4487 original expression. */
4490 fold_binary_op_with_conditional_arg (code, type, cond, arg, cond_first_p)
4491 enum tree_code code;
4497 tree test, true_value, false_value;
4498 tree lhs = NULL_TREE;
4499 tree rhs = NULL_TREE;
4500 /* In the end, we'll produce a COND_EXPR. Both arms of the
4501 conditional expression will be binary operations. The left-hand
4502 side of the expression to be executed if the condition is true
4503 will be pointed to by TRUE_LHS. Similarly, the right-hand side
4504 of the expression to be executed if the condition is true will be
4505 pointed to by TRUE_RHS. FALSE_LHS and FALSE_RHS are analogous --
4506 but apply to the expression to be executed if the conditional is
4512 /* These are the codes to use for the left-hand side and right-hand
4513 side of the COND_EXPR. Normally, they are the same as CODE. */
4514 enum tree_code lhs_code = code;
4515 enum tree_code rhs_code = code;
4516 /* And these are the types of the expressions. */
4517 tree lhs_type = type;
4518 tree rhs_type = type;
4523 true_rhs = false_rhs = &arg;
4524 true_lhs = &true_value;
4525 false_lhs = &false_value;
4529 true_lhs = false_lhs = &arg;
4530 true_rhs = &true_value;
4531 false_rhs = &false_value;
4534 if (TREE_CODE (cond) == COND_EXPR)
4536 test = TREE_OPERAND (cond, 0);
4537 true_value = TREE_OPERAND (cond, 1);
4538 false_value = TREE_OPERAND (cond, 2);
4539 /* If this operand throws an expression, then it does not make
4540 sense to try to perform a logical or arithmetic operation
4541 involving it. Instead of building `a + throw 3' for example,
4542 we simply build `a, throw 3'. */
4543 if (VOID_TYPE_P (TREE_TYPE (true_value)))
4547 lhs_code = COMPOUND_EXPR;
4548 lhs_type = void_type_node;
4553 if (VOID_TYPE_P (TREE_TYPE (false_value)))
4557 rhs_code = COMPOUND_EXPR;
4558 rhs_type = void_type_node;
4566 tree testtype = TREE_TYPE (cond);
4568 true_value = convert (testtype, integer_one_node);
4569 false_value = convert (testtype, integer_zero_node);
4572 /* If ARG is complex we want to make sure we only evaluate
4573 it once. Though this is only required if it is volatile, it
4574 might be more efficient even if it is not. However, if we
4575 succeed in folding one part to a constant, we do not need
4576 to make this SAVE_EXPR. Since we do this optimization
4577 primarily to see if we do end up with constant and this
4578 SAVE_EXPR interferes with later optimizations, suppressing
4579 it when we can is important.
4581 If we are not in a function, we can't make a SAVE_EXPR, so don't
4582 try to do so. Don't try to see if the result is a constant
4583 if an arm is a COND_EXPR since we get exponential behavior
4586 if (TREE_CODE (arg) == SAVE_EXPR)
4588 else if (lhs == 0 && rhs == 0
4589 && !TREE_CONSTANT (arg)
4590 && (*lang_hooks.decls.global_bindings_p) () == 0
4591 && ((TREE_CODE (arg) != VAR_DECL && TREE_CODE (arg) != PARM_DECL)
4592 || TREE_SIDE_EFFECTS (arg)))
4594 if (TREE_CODE (true_value) != COND_EXPR)
4595 lhs = fold (build (lhs_code, lhs_type, *true_lhs, *true_rhs));
4597 if (TREE_CODE (false_value) != COND_EXPR)
4598 rhs = fold (build (rhs_code, rhs_type, *false_lhs, *false_rhs));
4600 if ((lhs == 0 || ! TREE_CONSTANT (lhs))
4601 && (rhs == 0 || !TREE_CONSTANT (rhs)))
4603 arg = save_expr (arg);
4610 lhs = fold (build (lhs_code, lhs_type, *true_lhs, *true_rhs));
4612 rhs = fold (build (rhs_code, rhs_type, *false_lhs, *false_rhs));
4614 test = fold (build (COND_EXPR, type, test, lhs, rhs));
4617 return build (COMPOUND_EXPR, type,
4618 convert (void_type_node, arg),
4619 strip_compound_expr (test, arg));
4621 return convert (type, test);
4625 /* Subroutine of fold() that checks for the addition of +/- 0.0.
4627 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
4628 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
4629 ADDEND is the same as X.
4631 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
4632 and finite. The problematic cases are when X is zero, and its mode
4633 has signed zeros. In the case of rounding towards -infinity,
4634 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
4635 modes, X + 0 is not the same as X because -0 + 0 is 0. */
4638 fold_real_zero_addition_p (type, addend, negate)
4642 if (!real_zerop (addend))
4645 /* Don't allow the fold with -fsignaling-nans. */
4646 if (HONOR_SNANS (TYPE_MODE (type)))
4649 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
4650 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
4653 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
4654 if (TREE_CODE (addend) == REAL_CST
4655 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
4658 /* The mode has signed zeros, and we have to honor their sign.
4659 In this situation, there is only one case we can return true for.
4660 X - 0 is the same as X unless rounding towards -infinity is
4662 return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
4666 /* Perform constant folding and related simplification of EXPR.
4667 The related simplifications include x*1 => x, x*0 => 0, etc.,
4668 and application of the associative law.
4669 NOP_EXPR conversions may be removed freely (as long as we
4670 are careful not to change the C type of the overall expression)
4671 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
4672 but we can constant-fold them if they have constant operands. */
4679 tree t1 = NULL_TREE;
4681 tree type = TREE_TYPE (expr);
4682 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
4683 enum tree_code code = TREE_CODE (t);
4684 int kind = TREE_CODE_CLASS (code);
4686 /* WINS will be nonzero when the switch is done
4687 if all operands are constant. */
4690 /* Don't try to process an RTL_EXPR since its operands aren't trees.
4691 Likewise for a SAVE_EXPR that's already been evaluated. */
4692 if (code == RTL_EXPR || (code == SAVE_EXPR && SAVE_EXPR_RTL (t) != 0))
4695 /* Return right away if a constant. */
4699 #ifdef MAX_INTEGER_COMPUTATION_MODE
4700 check_max_integer_computation_mode (expr);
4703 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
4707 /* Special case for conversion ops that can have fixed point args. */
4708 arg0 = TREE_OPERAND (t, 0);
4710 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
4712 STRIP_SIGN_NOPS (arg0);
4714 if (arg0 != 0 && TREE_CODE (arg0) == COMPLEX_CST)
4715 subop = TREE_REALPART (arg0);
4719 if (subop != 0 && TREE_CODE (subop) != INTEGER_CST
4720 && TREE_CODE (subop) != REAL_CST
4722 /* Note that TREE_CONSTANT isn't enough:
4723 static var addresses are constant but we can't
4724 do arithmetic on them. */
4727 else if (IS_EXPR_CODE_CLASS (kind) || kind == 'r')
4729 int len = first_rtl_op (code);
4731 for (i = 0; i < len; i++)
4733 tree op = TREE_OPERAND (t, i);
4737 continue; /* Valid for CALL_EXPR, at least. */
4739 if (kind == '<' || code == RSHIFT_EXPR)
4741 /* Signedness matters here. Perhaps we can refine this
4743 STRIP_SIGN_NOPS (op);
4746 /* Strip any conversions that don't change the mode. */
4749 if (TREE_CODE (op) == COMPLEX_CST)
4750 subop = TREE_REALPART (op);
4754 if (TREE_CODE (subop) != INTEGER_CST
4755 && TREE_CODE (subop) != REAL_CST)
4756 /* Note that TREE_CONSTANT isn't enough:
4757 static var addresses are constant but we can't
4758 do arithmetic on them. */
4768 /* If this is a commutative operation, and ARG0 is a constant, move it
4769 to ARG1 to reduce the number of tests below. */
4770 if ((code == PLUS_EXPR || code == MULT_EXPR || code == MIN_EXPR
4771 || code == MAX_EXPR || code == BIT_IOR_EXPR || code == BIT_XOR_EXPR
4772 || code == BIT_AND_EXPR)
4773 && (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST))
4775 tem = arg0; arg0 = arg1; arg1 = tem;
4777 tem = TREE_OPERAND (t, 0); TREE_OPERAND (t, 0) = TREE_OPERAND (t, 1);
4778 TREE_OPERAND (t, 1) = tem;
4781 /* Now WINS is set as described above,
4782 ARG0 is the first operand of EXPR,
4783 and ARG1 is the second operand (if it has more than one operand).
4785 First check for cases where an arithmetic operation is applied to a
4786 compound, conditional, or comparison operation. Push the arithmetic
4787 operation inside the compound or conditional to see if any folding
4788 can then be done. Convert comparison to conditional for this purpose.
4789 The also optimizes non-constant cases that used to be done in
4792 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
4793 one of the operands is a comparison and the other is a comparison, a
4794 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
4795 code below would make the expression more complex. Change it to a
4796 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
4797 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
4799 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
4800 || code == EQ_EXPR || code == NE_EXPR)
4801 && ((truth_value_p (TREE_CODE (arg0))
4802 && (truth_value_p (TREE_CODE (arg1))
4803 || (TREE_CODE (arg1) == BIT_AND_EXPR
4804 && integer_onep (TREE_OPERAND (arg1, 1)))))
4805 || (truth_value_p (TREE_CODE (arg1))
4806 && (truth_value_p (TREE_CODE (arg0))
4807 || (TREE_CODE (arg0) == BIT_AND_EXPR
4808 && integer_onep (TREE_OPERAND (arg0, 1)))))))
4810 t = fold (build (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
4811 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
4815 if (code == EQ_EXPR)
4816 t = invert_truthvalue (t);
4821 if (TREE_CODE_CLASS (code) == '1')
4823 if (TREE_CODE (arg0) == COMPOUND_EXPR)
4824 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
4825 fold (build1 (code, type, TREE_OPERAND (arg0, 1))));
4826 else if (TREE_CODE (arg0) == COND_EXPR)
4828 tree arg01 = TREE_OPERAND (arg0, 1);
4829 tree arg02 = TREE_OPERAND (arg0, 2);
4830 if (! VOID_TYPE_P (TREE_TYPE (arg01)))
4831 arg01 = fold (build1 (code, type, arg01));
4832 if (! VOID_TYPE_P (TREE_TYPE (arg02)))
4833 arg02 = fold (build1 (code, type, arg02));
4834 t = fold (build (COND_EXPR, type, TREE_OPERAND (arg0, 0),
4837 /* If this was a conversion, and all we did was to move into
4838 inside the COND_EXPR, bring it back out. But leave it if
4839 it is a conversion from integer to integer and the
4840 result precision is no wider than a word since such a
4841 conversion is cheap and may be optimized away by combine,
4842 while it couldn't if it were outside the COND_EXPR. Then return
4843 so we don't get into an infinite recursion loop taking the
4844 conversion out and then back in. */
4846 if ((code == NOP_EXPR || code == CONVERT_EXPR
4847 || code == NON_LVALUE_EXPR)
4848 && TREE_CODE (t) == COND_EXPR
4849 && TREE_CODE (TREE_OPERAND (t, 1)) == code
4850 && TREE_CODE (TREE_OPERAND (t, 2)) == code
4851 && ! VOID_TYPE_P (TREE_OPERAND (t, 1))
4852 && ! VOID_TYPE_P (TREE_OPERAND (t, 2))
4853 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))
4854 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 2), 0)))
4855 && ! (INTEGRAL_TYPE_P (TREE_TYPE (t))
4857 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))))
4858 && TYPE_PRECISION (TREE_TYPE (t)) <= BITS_PER_WORD))
4859 t = build1 (code, type,
4861 TREE_TYPE (TREE_OPERAND
4862 (TREE_OPERAND (t, 1), 0)),
4863 TREE_OPERAND (t, 0),
4864 TREE_OPERAND (TREE_OPERAND (t, 1), 0),
4865 TREE_OPERAND (TREE_OPERAND (t, 2), 0)));
4868 else if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<')
4869 return fold (build (COND_EXPR, type, arg0,
4870 fold (build1 (code, type, integer_one_node)),
4871 fold (build1 (code, type, integer_zero_node))));
4873 else if (TREE_CODE_CLASS (code) == '2'
4874 || TREE_CODE_CLASS (code) == '<')
4876 if (TREE_CODE (arg1) == COMPOUND_EXPR
4877 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg1, 0))
4878 && ! TREE_SIDE_EFFECTS (arg0))
4879 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
4880 fold (build (code, type,
4881 arg0, TREE_OPERAND (arg1, 1))));
4882 else if ((TREE_CODE (arg1) == COND_EXPR
4883 || (TREE_CODE_CLASS (TREE_CODE (arg1)) == '<'
4884 && TREE_CODE_CLASS (code) != '<'))
4885 && (TREE_CODE (arg0) != COND_EXPR
4886 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
4887 && (! TREE_SIDE_EFFECTS (arg0)
4888 || ((*lang_hooks.decls.global_bindings_p) () == 0
4889 && ! contains_placeholder_p (arg0))))
4891 fold_binary_op_with_conditional_arg (code, type, arg1, arg0,
4892 /*cond_first_p=*/0);
4893 else if (TREE_CODE (arg0) == COMPOUND_EXPR)
4894 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
4895 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
4896 else if ((TREE_CODE (arg0) == COND_EXPR
4897 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
4898 && TREE_CODE_CLASS (code) != '<'))
4899 && (TREE_CODE (arg1) != COND_EXPR
4900 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
4901 && (! TREE_SIDE_EFFECTS (arg1)
4902 || ((*lang_hooks.decls.global_bindings_p) () == 0
4903 && ! contains_placeholder_p (arg1))))
4905 fold_binary_op_with_conditional_arg (code, type, arg0, arg1,
4906 /*cond_first_p=*/1);
4908 else if (TREE_CODE_CLASS (code) == '<'
4909 && TREE_CODE (arg0) == COMPOUND_EXPR)
4910 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
4911 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
4912 else if (TREE_CODE_CLASS (code) == '<'
4913 && TREE_CODE (arg1) == COMPOUND_EXPR)
4914 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
4915 fold (build (code, type, arg0, TREE_OPERAND (arg1, 1))));
4928 return fold (DECL_INITIAL (t));
4933 case FIX_TRUNC_EXPR:
4934 /* Other kinds of FIX are not handled properly by fold_convert. */
4936 if (TREE_TYPE (TREE_OPERAND (t, 0)) == TREE_TYPE (t))
4937 return TREE_OPERAND (t, 0);
4939 /* Handle cases of two conversions in a row. */
4940 if (TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
4941 || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR)
4943 tree inside_type = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
4944 tree inter_type = TREE_TYPE (TREE_OPERAND (t, 0));
4945 tree final_type = TREE_TYPE (t);
4946 int inside_int = INTEGRAL_TYPE_P (inside_type);
4947 int inside_ptr = POINTER_TYPE_P (inside_type);
4948 int inside_float = FLOAT_TYPE_P (inside_type);
4949 unsigned int inside_prec = TYPE_PRECISION (inside_type);
4950 int inside_unsignedp = TREE_UNSIGNED (inside_type);
4951 int inter_int = INTEGRAL_TYPE_P (inter_type);
4952 int inter_ptr = POINTER_TYPE_P (inter_type);
4953 int inter_float = FLOAT_TYPE_P (inter_type);
4954 unsigned int inter_prec = TYPE_PRECISION (inter_type);
4955 int inter_unsignedp = TREE_UNSIGNED (inter_type);
4956 int final_int = INTEGRAL_TYPE_P (final_type);
4957 int final_ptr = POINTER_TYPE_P (final_type);
4958 int final_float = FLOAT_TYPE_P (final_type);
4959 unsigned int final_prec = TYPE_PRECISION (final_type);
4960 int final_unsignedp = TREE_UNSIGNED (final_type);
4962 /* In addition to the cases of two conversions in a row
4963 handled below, if we are converting something to its own
4964 type via an object of identical or wider precision, neither
4965 conversion is needed. */
4966 if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (final_type)
4967 && ((inter_int && final_int) || (inter_float && final_float))
4968 && inter_prec >= final_prec)
4969 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
4971 /* Likewise, if the intermediate and final types are either both
4972 float or both integer, we don't need the middle conversion if
4973 it is wider than the final type and doesn't change the signedness
4974 (for integers). Avoid this if the final type is a pointer
4975 since then we sometimes need the inner conversion. Likewise if
4976 the outer has a precision not equal to the size of its mode. */
4977 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
4978 || (inter_float && inside_float))
4979 && inter_prec >= inside_prec
4980 && (inter_float || inter_unsignedp == inside_unsignedp)
4981 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
4982 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
4984 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
4986 /* If we have a sign-extension of a zero-extended value, we can
4987 replace that by a single zero-extension. */
4988 if (inside_int && inter_int && final_int
4989 && inside_prec < inter_prec && inter_prec < final_prec
4990 && inside_unsignedp && !inter_unsignedp)
4991 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
4993 /* Two conversions in a row are not needed unless:
4994 - some conversion is floating-point (overstrict for now), or
4995 - the intermediate type is narrower than both initial and
4997 - the intermediate type and innermost type differ in signedness,
4998 and the outermost type is wider than the intermediate, or
4999 - the initial type is a pointer type and the precisions of the
5000 intermediate and final types differ, or
5001 - the final type is a pointer type and the precisions of the
5002 initial and intermediate types differ. */
5003 if (! inside_float && ! inter_float && ! final_float
5004 && (inter_prec > inside_prec || inter_prec > final_prec)
5005 && ! (inside_int && inter_int
5006 && inter_unsignedp != inside_unsignedp
5007 && inter_prec < final_prec)
5008 && ((inter_unsignedp && inter_prec > inside_prec)
5009 == (final_unsignedp && final_prec > inter_prec))
5010 && ! (inside_ptr && inter_prec != final_prec)
5011 && ! (final_ptr && inside_prec != inter_prec)
5012 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
5013 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
5015 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5018 if (TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR
5019 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t, 0), 1))
5020 /* Detect assigning a bitfield. */
5021 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) == COMPONENT_REF
5022 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 1))))
5024 /* Don't leave an assignment inside a conversion
5025 unless assigning a bitfield. */
5026 tree prev = TREE_OPERAND (t, 0);
5027 TREE_OPERAND (t, 0) = TREE_OPERAND (prev, 1);
5028 /* First do the assignment, then return converted constant. */
5029 t = build (COMPOUND_EXPR, TREE_TYPE (t), prev, fold (t));
5034 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
5035 constants (if x has signed type, the sign bit cannot be set
5036 in c). This folds extension into the BIT_AND_EXPR. */
5037 if (INTEGRAL_TYPE_P (TREE_TYPE (t))
5038 && TREE_CODE (TREE_TYPE (t)) != BOOLEAN_TYPE
5039 && TREE_CODE (TREE_OPERAND (t, 0)) == BIT_AND_EXPR
5040 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 1)) == INTEGER_CST)
5042 tree and = TREE_OPERAND (t, 0);
5043 tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
5046 if (TREE_UNSIGNED (TREE_TYPE (and))
5047 || (TYPE_PRECISION (TREE_TYPE (t))
5048 <= TYPE_PRECISION (TREE_TYPE (and))))
5050 else if (TYPE_PRECISION (TREE_TYPE (and1))
5051 <= HOST_BITS_PER_WIDE_INT
5052 && host_integerp (and1, 1))
5054 unsigned HOST_WIDE_INT cst;
5056 cst = tree_low_cst (and1, 1);
5057 cst &= (HOST_WIDE_INT) -1
5058 << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
5059 change = (cst == 0);
5060 #ifdef LOAD_EXTEND_OP
5062 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
5065 tree uns = (*lang_hooks.types.unsigned_type) (TREE_TYPE (and0));
5066 and0 = convert (uns, and0);
5067 and1 = convert (uns, and1);
5072 return fold (build (BIT_AND_EXPR, TREE_TYPE (t),
5073 convert (TREE_TYPE (t), and0),
5074 convert (TREE_TYPE (t), and1)));
5079 TREE_CONSTANT (t) = TREE_CONSTANT (arg0);
5082 return fold_convert (t, arg0);
5084 case VIEW_CONVERT_EXPR:
5085 if (TREE_CODE (TREE_OPERAND (t, 0)) == VIEW_CONVERT_EXPR)
5086 return build1 (VIEW_CONVERT_EXPR, type,
5087 TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5091 if (TREE_CODE (arg0) == CONSTRUCTOR)
5093 tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0));
5100 TREE_CONSTANT (t) = wins;
5106 if (TREE_CODE (arg0) == INTEGER_CST)
5108 unsigned HOST_WIDE_INT low;
5110 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
5111 TREE_INT_CST_HIGH (arg0),
5113 t = build_int_2 (low, high);
5114 TREE_TYPE (t) = type;
5116 = (TREE_OVERFLOW (arg0)
5117 | force_fit_type (t, overflow && !TREE_UNSIGNED (type)));
5118 TREE_CONSTANT_OVERFLOW (t)
5119 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
5121 else if (TREE_CODE (arg0) == REAL_CST)
5122 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
5124 else if (TREE_CODE (arg0) == NEGATE_EXPR)
5125 return TREE_OPERAND (arg0, 0);
5126 /* Convert -((double)float) into (double)(-float). */
5127 else if (TREE_CODE (arg0) == NOP_EXPR
5128 && TREE_CODE (type) == REAL_TYPE)
5130 tree targ0 = strip_float_extensions (arg0);
5132 return convert (type, build1 (NEGATE_EXPR, TREE_TYPE (targ0), targ0));
5136 /* Convert - (a - b) to (b - a) for non-floating-point. */
5137 else if (TREE_CODE (arg0) == MINUS_EXPR
5138 && (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
5139 return build (MINUS_EXPR, type, TREE_OPERAND (arg0, 1),
5140 TREE_OPERAND (arg0, 0));
5147 if (TREE_CODE (arg0) == INTEGER_CST)
5149 /* If the value is unsigned, then the absolute value is
5150 the same as the ordinary value. */
5151 if (TREE_UNSIGNED (type))
5153 /* Similarly, if the value is non-negative. */
5154 else if (INT_CST_LT (integer_minus_one_node, arg0))
5156 /* If the value is negative, then the absolute value is
5160 unsigned HOST_WIDE_INT low;
5162 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
5163 TREE_INT_CST_HIGH (arg0),
5165 t = build_int_2 (low, high);
5166 TREE_TYPE (t) = type;
5168 = (TREE_OVERFLOW (arg0)
5169 | force_fit_type (t, overflow));
5170 TREE_CONSTANT_OVERFLOW (t)
5171 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
5174 else if (TREE_CODE (arg0) == REAL_CST)
5176 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
5177 t = build_real (type,
5178 REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
5181 else if (TREE_CODE (arg0) == ABS_EXPR || TREE_CODE (arg0) == NEGATE_EXPR)
5182 return build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0));
5183 /* Convert fabs((double)float) into (double)fabsf(float). */
5184 else if (TREE_CODE (arg0) == NOP_EXPR
5185 && TREE_CODE (type) == REAL_TYPE)
5187 tree targ0 = strip_float_extensions (arg0);
5189 return convert (type, build1 (ABS_EXPR, TREE_TYPE (targ0), targ0));
5194 /* fabs(sqrt(x)) = sqrt(x) and fabs(exp(x)) = exp(x). */
5195 enum built_in_function fcode = builtin_mathfn_code (arg0);
5196 if (fcode == BUILT_IN_SQRT
5197 || fcode == BUILT_IN_SQRTF
5198 || fcode == BUILT_IN_SQRTL
5199 || fcode == BUILT_IN_EXP
5200 || fcode == BUILT_IN_EXPF
5201 || fcode == BUILT_IN_EXPL)
5207 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
5208 return convert (type, arg0);
5209 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
5210 return build (COMPLEX_EXPR, type,
5211 TREE_OPERAND (arg0, 0),
5212 negate_expr (TREE_OPERAND (arg0, 1)));
5213 else if (TREE_CODE (arg0) == COMPLEX_CST)
5214 return build_complex (type, TREE_REALPART (arg0),
5215 negate_expr (TREE_IMAGPART (arg0)));
5216 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
5217 return fold (build (TREE_CODE (arg0), type,
5218 fold (build1 (CONJ_EXPR, type,
5219 TREE_OPERAND (arg0, 0))),
5220 fold (build1 (CONJ_EXPR,
5221 type, TREE_OPERAND (arg0, 1)))));
5222 else if (TREE_CODE (arg0) == CONJ_EXPR)
5223 return TREE_OPERAND (arg0, 0);
5229 t = build_int_2 (~ TREE_INT_CST_LOW (arg0),
5230 ~ TREE_INT_CST_HIGH (arg0));
5231 TREE_TYPE (t) = type;
5232 force_fit_type (t, 0);
5233 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg0);
5234 TREE_CONSTANT_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (arg0);
5236 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
5237 return TREE_OPERAND (arg0, 0);
5241 /* A + (-B) -> A - B */
5242 if (TREE_CODE (arg1) == NEGATE_EXPR)
5243 return fold (build (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5244 /* (-A) + B -> B - A */
5245 if (TREE_CODE (arg0) == NEGATE_EXPR)
5246 return fold (build (MINUS_EXPR, type, arg1, TREE_OPERAND (arg0, 0)));
5247 else if (! FLOAT_TYPE_P (type))
5249 if (integer_zerop (arg1))
5250 return non_lvalue (convert (type, arg0));
5252 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
5253 with a constant, and the two constants have no bits in common,
5254 we should treat this as a BIT_IOR_EXPR since this may produce more
5256 if (TREE_CODE (arg0) == BIT_AND_EXPR
5257 && TREE_CODE (arg1) == BIT_AND_EXPR
5258 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5259 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
5260 && integer_zerop (const_binop (BIT_AND_EXPR,
5261 TREE_OPERAND (arg0, 1),
5262 TREE_OPERAND (arg1, 1), 0)))
5264 code = BIT_IOR_EXPR;
5268 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
5269 (plus (plus (mult) (mult)) (foo)) so that we can
5270 take advantage of the factoring cases below. */
5271 if ((TREE_CODE (arg0) == PLUS_EXPR
5272 && TREE_CODE (arg1) == MULT_EXPR)
5273 || (TREE_CODE (arg1) == PLUS_EXPR
5274 && TREE_CODE (arg0) == MULT_EXPR))
5276 tree parg0, parg1, parg, marg;
5278 if (TREE_CODE (arg0) == PLUS_EXPR)
5279 parg = arg0, marg = arg1;
5281 parg = arg1, marg = arg0;
5282 parg0 = TREE_OPERAND (parg, 0);
5283 parg1 = TREE_OPERAND (parg, 1);
5287 if (TREE_CODE (parg0) == MULT_EXPR
5288 && TREE_CODE (parg1) != MULT_EXPR)
5289 return fold (build (PLUS_EXPR, type,
5290 fold (build (PLUS_EXPR, type, parg0, marg)),
5292 if (TREE_CODE (parg0) != MULT_EXPR
5293 && TREE_CODE (parg1) == MULT_EXPR)
5294 return fold (build (PLUS_EXPR, type,
5295 fold (build (PLUS_EXPR, type, parg1, marg)),
5299 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR)
5301 tree arg00, arg01, arg10, arg11;
5302 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
5304 /* (A * C) + (B * C) -> (A+B) * C.
5305 We are most concerned about the case where C is a constant,
5306 but other combinations show up during loop reduction. Since
5307 it is not difficult, try all four possibilities. */
5309 arg00 = TREE_OPERAND (arg0, 0);
5310 arg01 = TREE_OPERAND (arg0, 1);
5311 arg10 = TREE_OPERAND (arg1, 0);
5312 arg11 = TREE_OPERAND (arg1, 1);
5315 if (operand_equal_p (arg01, arg11, 0))
5316 same = arg01, alt0 = arg00, alt1 = arg10;
5317 else if (operand_equal_p (arg00, arg10, 0))
5318 same = arg00, alt0 = arg01, alt1 = arg11;
5319 else if (operand_equal_p (arg00, arg11, 0))
5320 same = arg00, alt0 = arg01, alt1 = arg10;
5321 else if (operand_equal_p (arg01, arg10, 0))
5322 same = arg01, alt0 = arg00, alt1 = arg11;
5324 /* No identical multiplicands; see if we can find a common
5325 power-of-two factor in non-power-of-two multiplies. This
5326 can help in multi-dimensional array access. */
5327 else if (TREE_CODE (arg01) == INTEGER_CST
5328 && TREE_CODE (arg11) == INTEGER_CST
5329 && TREE_INT_CST_HIGH (arg01) == 0
5330 && TREE_INT_CST_HIGH (arg11) == 0)
5332 HOST_WIDE_INT int01, int11, tmp;
5333 int01 = TREE_INT_CST_LOW (arg01);
5334 int11 = TREE_INT_CST_LOW (arg11);
5336 /* Move min of absolute values to int11. */
5337 if ((int01 >= 0 ? int01 : -int01)
5338 < (int11 >= 0 ? int11 : -int11))
5340 tmp = int01, int01 = int11, int11 = tmp;
5341 alt0 = arg00, arg00 = arg10, arg10 = alt0;
5342 alt0 = arg01, arg01 = arg11, arg11 = alt0;
5345 if (exact_log2 (int11) > 0 && int01 % int11 == 0)
5347 alt0 = fold (build (MULT_EXPR, type, arg00,
5348 build_int_2 (int01 / int11, 0)));
5355 return fold (build (MULT_EXPR, type,
5356 fold (build (PLUS_EXPR, type, alt0, alt1)),
5361 /* See if ARG1 is zero and X + ARG1 reduces to X. */
5362 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
5363 return non_lvalue (convert (type, arg0));
5365 /* Likewise if the operands are reversed. */
5366 else if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
5367 return non_lvalue (convert (type, arg1));
5370 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
5371 is a rotate of A by C1 bits. */
5372 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
5373 is a rotate of A by B bits. */
5375 enum tree_code code0, code1;
5376 code0 = TREE_CODE (arg0);
5377 code1 = TREE_CODE (arg1);
5378 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
5379 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
5380 && operand_equal_p (TREE_OPERAND (arg0, 0),
5381 TREE_OPERAND (arg1, 0), 0)
5382 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5384 tree tree01, tree11;
5385 enum tree_code code01, code11;
5387 tree01 = TREE_OPERAND (arg0, 1);
5388 tree11 = TREE_OPERAND (arg1, 1);
5389 STRIP_NOPS (tree01);
5390 STRIP_NOPS (tree11);
5391 code01 = TREE_CODE (tree01);
5392 code11 = TREE_CODE (tree11);
5393 if (code01 == INTEGER_CST
5394 && code11 == INTEGER_CST
5395 && TREE_INT_CST_HIGH (tree01) == 0
5396 && TREE_INT_CST_HIGH (tree11) == 0
5397 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
5398 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
5399 return build (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
5400 code0 == LSHIFT_EXPR ? tree01 : tree11);
5401 else if (code11 == MINUS_EXPR)
5403 tree tree110, tree111;
5404 tree110 = TREE_OPERAND (tree11, 0);
5405 tree111 = TREE_OPERAND (tree11, 1);
5406 STRIP_NOPS (tree110);
5407 STRIP_NOPS (tree111);
5408 if (TREE_CODE (tree110) == INTEGER_CST
5409 && 0 == compare_tree_int (tree110,
5411 (TREE_TYPE (TREE_OPERAND
5413 && operand_equal_p (tree01, tree111, 0))
5414 return build ((code0 == LSHIFT_EXPR
5417 type, TREE_OPERAND (arg0, 0), tree01);
5419 else if (code01 == MINUS_EXPR)
5421 tree tree010, tree011;
5422 tree010 = TREE_OPERAND (tree01, 0);
5423 tree011 = TREE_OPERAND (tree01, 1);
5424 STRIP_NOPS (tree010);
5425 STRIP_NOPS (tree011);
5426 if (TREE_CODE (tree010) == INTEGER_CST
5427 && 0 == compare_tree_int (tree010,
5429 (TREE_TYPE (TREE_OPERAND
5431 && operand_equal_p (tree11, tree011, 0))
5432 return build ((code0 != LSHIFT_EXPR
5435 type, TREE_OPERAND (arg0, 0), tree11);
5441 /* In most languages, can't associate operations on floats through
5442 parentheses. Rather than remember where the parentheses were, we
5443 don't associate floats at all. It shouldn't matter much. However,
5444 associating multiplications is only very slightly inaccurate, so do
5445 that if -funsafe-math-optimizations is specified. */
5448 && (! FLOAT_TYPE_P (type)
5449 || (flag_unsafe_math_optimizations && code == MULT_EXPR)))
5451 tree var0, con0, lit0, minus_lit0;
5452 tree var1, con1, lit1, minus_lit1;
5454 /* Split both trees into variables, constants, and literals. Then
5455 associate each group together, the constants with literals,
5456 then the result with variables. This increases the chances of
5457 literals being recombined later and of generating relocatable
5458 expressions for the sum of a constant and literal. */
5459 var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
5460 var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
5461 code == MINUS_EXPR);
5463 /* Only do something if we found more than two objects. Otherwise,
5464 nothing has changed and we risk infinite recursion. */
5465 if (2 < ((var0 != 0) + (var1 != 0)
5466 + (con0 != 0) + (con1 != 0)
5467 + (lit0 != 0) + (lit1 != 0)
5468 + (minus_lit0 != 0) + (minus_lit1 != 0)))
5470 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
5471 if (code == MINUS_EXPR)
5474 var0 = associate_trees (var0, var1, code, type);
5475 con0 = associate_trees (con0, con1, code, type);
5476 lit0 = associate_trees (lit0, lit1, code, type);
5477 minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
5479 /* Preserve the MINUS_EXPR if the negative part of the literal is
5480 greater than the positive part. Otherwise, the multiplicative
5481 folding code (i.e extract_muldiv) may be fooled in case
5482 unsigned constants are substracted, like in the following
5483 example: ((X*2 + 4) - 8U)/2. */
5484 if (minus_lit0 && lit0)
5486 if (tree_int_cst_lt (lit0, minus_lit0))
5488 minus_lit0 = associate_trees (minus_lit0, lit0,
5494 lit0 = associate_trees (lit0, minus_lit0,
5502 return convert (type, associate_trees (var0, minus_lit0,
5506 con0 = associate_trees (con0, minus_lit0,
5508 return convert (type, associate_trees (var0, con0,
5513 con0 = associate_trees (con0, lit0, code, type);
5514 return convert (type, associate_trees (var0, con0, code, type));
5520 t1 = const_binop (code, arg0, arg1, 0);
5521 if (t1 != NULL_TREE)
5523 /* The return value should always have
5524 the same type as the original expression. */
5525 if (TREE_TYPE (t1) != TREE_TYPE (t))
5526 t1 = convert (TREE_TYPE (t), t1);
5533 /* A - (-B) -> A + B */
5534 if (TREE_CODE (arg1) == NEGATE_EXPR)
5535 return fold (build (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5536 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
5537 if (TREE_CODE (arg0) == NEGATE_EXPR
5538 && FLOAT_TYPE_P (type)
5539 && negate_expr_p (arg1)
5540 && (! TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
5541 && (! TREE_SIDE_EFFECTS (arg1) || TREE_CONSTANT (arg0)))
5542 return fold (build (MINUS_EXPR, type, negate_expr (arg1),
5543 TREE_OPERAND (arg0, 0)));
5545 if (! FLOAT_TYPE_P (type))
5547 if (! wins && integer_zerop (arg0))
5548 return negate_expr (convert (type, arg1));
5549 if (integer_zerop (arg1))
5550 return non_lvalue (convert (type, arg0));
5552 /* (A * C) - (B * C) -> (A-B) * C. Since we are most concerned
5553 about the case where C is a constant, just try one of the
5554 four possibilities. */
5556 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR
5557 && operand_equal_p (TREE_OPERAND (arg0, 1),
5558 TREE_OPERAND (arg1, 1), 0))
5559 return fold (build (MULT_EXPR, type,
5560 fold (build (MINUS_EXPR, type,
5561 TREE_OPERAND (arg0, 0),
5562 TREE_OPERAND (arg1, 0))),
5563 TREE_OPERAND (arg0, 1)));
5566 /* See if ARG1 is zero and X - ARG1 reduces to X. */
5567 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
5568 return non_lvalue (convert (type, arg0));
5570 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
5571 ARG0 is zero and X + ARG0 reduces to X, since that would mean
5572 (-ARG1 + ARG0) reduces to -ARG1. */
5573 else if (!wins && fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
5574 return negate_expr (convert (type, arg1));
5576 /* Fold &x - &x. This can happen from &x.foo - &x.
5577 This is unsafe for certain floats even in non-IEEE formats.
5578 In IEEE, it is unsafe because it does wrong for NaNs.
5579 Also note that operand_equal_p is always false if an operand
5582 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
5583 && operand_equal_p (arg0, arg1, 0))
5584 return convert (type, integer_zero_node);
5589 /* (-A) * (-B) -> A * B */
5590 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR)
5591 return fold (build (MULT_EXPR, type, TREE_OPERAND (arg0, 0),
5592 TREE_OPERAND (arg1, 0)));
5594 if (! FLOAT_TYPE_P (type))
5596 if (integer_zerop (arg1))
5597 return omit_one_operand (type, arg1, arg0);
5598 if (integer_onep (arg1))
5599 return non_lvalue (convert (type, arg0));
5601 /* (a * (1 << b)) is (a << b) */
5602 if (TREE_CODE (arg1) == LSHIFT_EXPR
5603 && integer_onep (TREE_OPERAND (arg1, 0)))
5604 return fold (build (LSHIFT_EXPR, type, arg0,
5605 TREE_OPERAND (arg1, 1)));
5606 if (TREE_CODE (arg0) == LSHIFT_EXPR
5607 && integer_onep (TREE_OPERAND (arg0, 0)))
5608 return fold (build (LSHIFT_EXPR, type, arg1,
5609 TREE_OPERAND (arg0, 1)));
5611 if (TREE_CODE (arg1) == INTEGER_CST
5612 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
5614 return convert (type, tem);
5619 /* Maybe fold x * 0 to 0. The expressions aren't the same
5620 when x is NaN, since x * 0 is also NaN. Nor are they the
5621 same in modes with signed zeros, since multiplying a
5622 negative value by 0 gives -0, not +0. */
5623 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
5624 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
5625 && real_zerop (arg1))
5626 return omit_one_operand (type, arg1, arg0);
5627 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
5628 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
5629 && real_onep (arg1))
5630 return non_lvalue (convert (type, arg0));
5632 /* Transform x * -1.0 into -x. */
5633 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
5634 && real_minus_onep (arg1))
5635 return fold (build1 (NEGATE_EXPR, type, arg0));
5638 if (! wins && real_twop (arg1)
5639 && (*lang_hooks.decls.global_bindings_p) () == 0
5640 && ! contains_placeholder_p (arg0))
5642 tree arg = save_expr (arg0);
5643 return build (PLUS_EXPR, type, arg, arg);
5646 if (flag_unsafe_math_optimizations)
5648 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
5649 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
5651 /* Optimize sqrt(x)*sqrt(y) as sqrt(x*y). */
5652 if ((fcode0 == BUILT_IN_SQRT && fcode1 == BUILT_IN_SQRT)
5653 || (fcode0 == BUILT_IN_SQRTF && fcode1 == BUILT_IN_SQRTF)
5654 || (fcode0 == BUILT_IN_SQRTL && fcode1 == BUILT_IN_SQRTL))
5656 tree sqrtfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
5657 tree arg = build (MULT_EXPR, type,
5658 TREE_VALUE (TREE_OPERAND (arg0, 1)),
5659 TREE_VALUE (TREE_OPERAND (arg1, 1)));
5660 tree arglist = build_tree_list (NULL_TREE, arg);
5661 return fold (build_function_call_expr (sqrtfn, arglist));
5664 /* Optimize exp(x)*exp(y) as exp(x+y). */
5665 if ((fcode0 == BUILT_IN_EXP && fcode1 == BUILT_IN_EXP)
5666 || (fcode0 == BUILT_IN_EXPF && fcode1 == BUILT_IN_EXPF)
5667 || (fcode0 == BUILT_IN_EXPL && fcode1 == BUILT_IN_EXPL))
5669 tree expfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
5670 tree arg = build (PLUS_EXPR, type,
5671 TREE_VALUE (TREE_OPERAND (arg0, 1)),
5672 TREE_VALUE (TREE_OPERAND (arg1, 1)));
5673 tree arglist = build_tree_list (NULL_TREE, arg);
5674 return fold (build_function_call_expr (expfn, arglist));
5682 if (integer_all_onesp (arg1))
5683 return omit_one_operand (type, arg1, arg0);
5684 if (integer_zerop (arg1))
5685 return non_lvalue (convert (type, arg0));
5686 t1 = distribute_bit_expr (code, type, arg0, arg1);
5687 if (t1 != NULL_TREE)
5690 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
5692 This results in more efficient code for machines without a NAND
5693 instruction. Combine will canonicalize to the first form
5694 which will allow use of NAND instructions provided by the
5695 backend if they exist. */
5696 if (TREE_CODE (arg0) == BIT_NOT_EXPR
5697 && TREE_CODE (arg1) == BIT_NOT_EXPR)
5699 return fold (build1 (BIT_NOT_EXPR, type,
5700 build (BIT_AND_EXPR, type,
5701 TREE_OPERAND (arg0, 0),
5702 TREE_OPERAND (arg1, 0))));
5705 /* See if this can be simplified into a rotate first. If that
5706 is unsuccessful continue in the association code. */
5710 if (integer_zerop (arg1))
5711 return non_lvalue (convert (type, arg0));
5712 if (integer_all_onesp (arg1))
5713 return fold (build1 (BIT_NOT_EXPR, type, arg0));
5715 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
5716 with a constant, and the two constants have no bits in common,
5717 we should treat this as a BIT_IOR_EXPR since this may produce more
5719 if (TREE_CODE (arg0) == BIT_AND_EXPR
5720 && TREE_CODE (arg1) == BIT_AND_EXPR
5721 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5722 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
5723 && integer_zerop (const_binop (BIT_AND_EXPR,
5724 TREE_OPERAND (arg0, 1),
5725 TREE_OPERAND (arg1, 1), 0)))
5727 code = BIT_IOR_EXPR;
5731 /* See if this can be simplified into a rotate first. If that
5732 is unsuccessful continue in the association code. */
5737 if (integer_all_onesp (arg1))
5738 return non_lvalue (convert (type, arg0));
5739 if (integer_zerop (arg1))
5740 return omit_one_operand (type, arg1, arg0);
5741 t1 = distribute_bit_expr (code, type, arg0, arg1);
5742 if (t1 != NULL_TREE)
5744 /* Simplify ((int)c & 0x377) into (int)c, if c is unsigned char. */
5745 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
5746 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5749 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
5751 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
5752 && (~TREE_INT_CST_LOW (arg1)
5753 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
5754 return build1 (NOP_EXPR, type, TREE_OPERAND (arg0, 0));
5757 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
5759 This results in more efficient code for machines without a NOR
5760 instruction. Combine will canonicalize to the first form
5761 which will allow use of NOR instructions provided by the
5762 backend if they exist. */
5763 if (TREE_CODE (arg0) == BIT_NOT_EXPR
5764 && TREE_CODE (arg1) == BIT_NOT_EXPR)
5766 return fold (build1 (BIT_NOT_EXPR, type,
5767 build (BIT_IOR_EXPR, type,
5768 TREE_OPERAND (arg0, 0),
5769 TREE_OPERAND (arg1, 0))));
5774 case BIT_ANDTC_EXPR:
5775 if (integer_all_onesp (arg0))
5776 return non_lvalue (convert (type, arg1));
5777 if (integer_zerop (arg0))
5778 return omit_one_operand (type, arg0, arg1);
5779 if (TREE_CODE (arg1) == INTEGER_CST)
5781 arg1 = fold (build1 (BIT_NOT_EXPR, type, arg1));
5782 code = BIT_AND_EXPR;
5788 /* Don't touch a floating-point divide by zero unless the mode
5789 of the constant can represent infinity. */
5790 if (TREE_CODE (arg1) == REAL_CST
5791 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
5792 && real_zerop (arg1))
5795 /* (-A) / (-B) -> A / B */
5796 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR)
5797 return fold (build (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
5798 TREE_OPERAND (arg1, 0)));
5800 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
5801 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
5802 && real_onep (arg1))
5803 return non_lvalue (convert (type, arg0));
5805 /* If ARG1 is a constant, we can convert this to a multiply by the
5806 reciprocal. This does not have the same rounding properties,
5807 so only do this if -funsafe-math-optimizations. We can actually
5808 always safely do it if ARG1 is a power of two, but it's hard to
5809 tell if it is or not in a portable manner. */
5810 if (TREE_CODE (arg1) == REAL_CST)
5812 if (flag_unsafe_math_optimizations
5813 && 0 != (tem = const_binop (code, build_real (type, dconst1),
5815 return fold (build (MULT_EXPR, type, arg0, tem));
5816 /* Find the reciprocal if optimizing and the result is exact. */
5820 r = TREE_REAL_CST (arg1);
5821 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
5823 tem = build_real (type, r);
5824 return fold (build (MULT_EXPR, type, arg0, tem));
5828 /* Convert A/B/C to A/(B*C). */
5829 if (flag_unsafe_math_optimizations
5830 && TREE_CODE (arg0) == RDIV_EXPR)
5832 return fold (build (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
5833 build (MULT_EXPR, type, TREE_OPERAND (arg0, 1),
5836 /* Convert A/(B/C) to (A/B)*C. */
5837 if (flag_unsafe_math_optimizations
5838 && TREE_CODE (arg1) == RDIV_EXPR)
5840 return fold (build (MULT_EXPR, type,
5841 build (RDIV_EXPR, type, arg0,
5842 TREE_OPERAND (arg1, 0)),
5843 TREE_OPERAND (arg1, 1)));
5846 /* Optimize x/exp(y) into x*exp(-y). */
5847 if (flag_unsafe_math_optimizations)
5849 enum built_in_function fcode = builtin_mathfn_code (arg1);
5850 if (fcode == BUILT_IN_EXP
5851 || fcode == BUILT_IN_EXPF
5852 || fcode == BUILT_IN_EXPL)
5854 tree expfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
5855 tree arg = build1 (NEGATE_EXPR, type,
5856 TREE_VALUE (TREE_OPERAND (arg1, 1)));
5857 tree arglist = build_tree_list (NULL_TREE, arg);
5858 arg1 = build_function_call_expr (expfn, arglist);
5859 return fold (build (MULT_EXPR, type, arg0, arg1));
5864 case TRUNC_DIV_EXPR:
5865 case ROUND_DIV_EXPR:
5866 case FLOOR_DIV_EXPR:
5868 case EXACT_DIV_EXPR:
5869 if (integer_onep (arg1))
5870 return non_lvalue (convert (type, arg0));
5871 if (integer_zerop (arg1))
5874 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
5875 operation, EXACT_DIV_EXPR.
5877 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
5878 At one time others generated faster code, it's not clear if they do
5879 after the last round to changes to the DIV code in expmed.c. */
5880 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
5881 && multiple_of_p (type, arg0, arg1))
5882 return fold (build (EXACT_DIV_EXPR, type, arg0, arg1));
5884 if (TREE_CODE (arg1) == INTEGER_CST
5885 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
5887 return convert (type, tem);
5892 case FLOOR_MOD_EXPR:
5893 case ROUND_MOD_EXPR:
5894 case TRUNC_MOD_EXPR:
5895 if (integer_onep (arg1))
5896 return omit_one_operand (type, integer_zero_node, arg0);
5897 if (integer_zerop (arg1))
5900 if (TREE_CODE (arg1) == INTEGER_CST
5901 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
5903 return convert (type, tem);
5909 if (integer_all_onesp (arg0))
5910 return omit_one_operand (type, arg0, arg1);
5914 /* Optimize -1 >> x for arithmetic right shifts. */
5915 if (integer_all_onesp (arg0) && ! TREE_UNSIGNED (type))
5916 return omit_one_operand (type, arg0, arg1);
5917 /* ... fall through ... */
5921 if (integer_zerop (arg1))
5922 return non_lvalue (convert (type, arg0));
5923 if (integer_zerop (arg0))
5924 return omit_one_operand (type, arg0, arg1);
5926 /* Since negative shift count is not well-defined,
5927 don't try to compute it in the compiler. */
5928 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
5930 /* Rewrite an LROTATE_EXPR by a constant into an
5931 RROTATE_EXPR by a new constant. */
5932 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
5934 TREE_SET_CODE (t, RROTATE_EXPR);
5935 code = RROTATE_EXPR;
5936 TREE_OPERAND (t, 1) = arg1
5939 convert (TREE_TYPE (arg1),
5940 build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type)), 0)),
5942 if (tree_int_cst_sgn (arg1) < 0)
5946 /* If we have a rotate of a bit operation with the rotate count and
5947 the second operand of the bit operation both constant,
5948 permute the two operations. */
5949 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
5950 && (TREE_CODE (arg0) == BIT_AND_EXPR
5951 || TREE_CODE (arg0) == BIT_ANDTC_EXPR
5952 || TREE_CODE (arg0) == BIT_IOR_EXPR
5953 || TREE_CODE (arg0) == BIT_XOR_EXPR)
5954 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
5955 return fold (build (TREE_CODE (arg0), type,
5956 fold (build (code, type,
5957 TREE_OPERAND (arg0, 0), arg1)),
5958 fold (build (code, type,
5959 TREE_OPERAND (arg0, 1), arg1))));
5961 /* Two consecutive rotates adding up to the width of the mode can
5963 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
5964 && TREE_CODE (arg0) == RROTATE_EXPR
5965 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5966 && TREE_INT_CST_HIGH (arg1) == 0
5967 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
5968 && ((TREE_INT_CST_LOW (arg1)
5969 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
5970 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type))))
5971 return TREE_OPERAND (arg0, 0);
5976 if (operand_equal_p (arg0, arg1, 0))
5977 return omit_one_operand (type, arg0, arg1);
5978 if (INTEGRAL_TYPE_P (type)
5979 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), 1))
5980 return omit_one_operand (type, arg1, arg0);
5984 if (operand_equal_p (arg0, arg1, 0))
5985 return omit_one_operand (type, arg0, arg1);
5986 if (INTEGRAL_TYPE_P (type)
5987 && TYPE_MAX_VALUE (type)
5988 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), 1))
5989 return omit_one_operand (type, arg1, arg0);
5992 case TRUTH_NOT_EXPR:
5993 /* Note that the operand of this must be an int
5994 and its values must be 0 or 1.
5995 ("true" is a fixed value perhaps depending on the language,
5996 but we don't handle values other than 1 correctly yet.) */
5997 tem = invert_truthvalue (arg0);
5998 /* Avoid infinite recursion. */
5999 if (TREE_CODE (tem) == TRUTH_NOT_EXPR)
6001 return convert (type, tem);
6003 case TRUTH_ANDIF_EXPR:
6004 /* Note that the operands of this must be ints
6005 and their values must be 0 or 1.
6006 ("true" is a fixed value perhaps depending on the language.) */
6007 /* If first arg is constant zero, return it. */
6008 if (integer_zerop (arg0))
6009 return convert (type, arg0);
6010 case TRUTH_AND_EXPR:
6011 /* If either arg is constant true, drop it. */
6012 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
6013 return non_lvalue (convert (type, arg1));
6014 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
6015 /* Preserve sequence points. */
6016 && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
6017 return non_lvalue (convert (type, arg0));
6018 /* If second arg is constant zero, result is zero, but first arg
6019 must be evaluated. */
6020 if (integer_zerop (arg1))
6021 return omit_one_operand (type, arg1, arg0);
6022 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
6023 case will be handled here. */
6024 if (integer_zerop (arg0))
6025 return omit_one_operand (type, arg0, arg1);
6028 /* We only do these simplifications if we are optimizing. */
6032 /* Check for things like (A || B) && (A || C). We can convert this
6033 to A || (B && C). Note that either operator can be any of the four
6034 truth and/or operations and the transformation will still be
6035 valid. Also note that we only care about order for the
6036 ANDIF and ORIF operators. If B contains side effects, this
6037 might change the truth-value of A. */
6038 if (TREE_CODE (arg0) == TREE_CODE (arg1)
6039 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
6040 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
6041 || TREE_CODE (arg0) == TRUTH_AND_EXPR
6042 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
6043 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
6045 tree a00 = TREE_OPERAND (arg0, 0);
6046 tree a01 = TREE_OPERAND (arg0, 1);
6047 tree a10 = TREE_OPERAND (arg1, 0);
6048 tree a11 = TREE_OPERAND (arg1, 1);
6049 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
6050 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
6051 && (code == TRUTH_AND_EXPR
6052 || code == TRUTH_OR_EXPR));
6054 if (operand_equal_p (a00, a10, 0))
6055 return fold (build (TREE_CODE (arg0), type, a00,
6056 fold (build (code, type, a01, a11))));
6057 else if (commutative && operand_equal_p (a00, a11, 0))
6058 return fold (build (TREE_CODE (arg0), type, a00,
6059 fold (build (code, type, a01, a10))));
6060 else if (commutative && operand_equal_p (a01, a10, 0))
6061 return fold (build (TREE_CODE (arg0), type, a01,
6062 fold (build (code, type, a00, a11))));
6064 /* This case if tricky because we must either have commutative
6065 operators or else A10 must not have side-effects. */
6067 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
6068 && operand_equal_p (a01, a11, 0))
6069 return fold (build (TREE_CODE (arg0), type,
6070 fold (build (code, type, a00, a10)),
6074 /* See if we can build a range comparison. */
6075 if (0 != (tem = fold_range_test (t)))
6078 /* Check for the possibility of merging component references. If our
6079 lhs is another similar operation, try to merge its rhs with our
6080 rhs. Then try to merge our lhs and rhs. */
6081 if (TREE_CODE (arg0) == code
6082 && 0 != (tem = fold_truthop (code, type,
6083 TREE_OPERAND (arg0, 1), arg1)))
6084 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6086 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
6091 case TRUTH_ORIF_EXPR:
6092 /* Note that the operands of this must be ints
6093 and their values must be 0 or true.
6094 ("true" is a fixed value perhaps depending on the language.) */
6095 /* If first arg is constant true, return it. */
6096 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
6097 return convert (type, arg0);
6099 /* If either arg is constant zero, drop it. */
6100 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
6101 return non_lvalue (convert (type, arg1));
6102 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
6103 /* Preserve sequence points. */
6104 && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
6105 return non_lvalue (convert (type, arg0));
6106 /* If second arg is constant true, result is true, but we must
6107 evaluate first arg. */
6108 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
6109 return omit_one_operand (type, arg1, arg0);
6110 /* Likewise for first arg, but note this only occurs here for
6112 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
6113 return omit_one_operand (type, arg0, arg1);
6116 case TRUTH_XOR_EXPR:
6117 /* If either arg is constant zero, drop it. */
6118 if (integer_zerop (arg0))
6119 return non_lvalue (convert (type, arg1));
6120 if (integer_zerop (arg1))
6121 return non_lvalue (convert (type, arg0));
6122 /* If either arg is constant true, this is a logical inversion. */
6123 if (integer_onep (arg0))
6124 return non_lvalue (convert (type, invert_truthvalue (arg1)));
6125 if (integer_onep (arg1))
6126 return non_lvalue (convert (type, invert_truthvalue (arg0)));
6135 /* If one arg is a real or integer constant, put it last. */
6136 if ((TREE_CODE (arg0) == INTEGER_CST
6137 && TREE_CODE (arg1) != INTEGER_CST)
6138 || (TREE_CODE (arg0) == REAL_CST
6139 && TREE_CODE (arg0) != REAL_CST))
6141 TREE_OPERAND (t, 0) = arg1;
6142 TREE_OPERAND (t, 1) = arg0;
6143 arg0 = TREE_OPERAND (t, 0);
6144 arg1 = TREE_OPERAND (t, 1);
6145 code = swap_tree_comparison (code);
6146 TREE_SET_CODE (t, code);
6149 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
6151 tree targ0 = strip_float_extensions (arg0);
6152 tree targ1 = strip_float_extensions (arg1);
6153 tree newtype = TREE_TYPE (targ0);
6155 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
6156 newtype = TREE_TYPE (targ1);
6158 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
6159 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
6160 return fold (build (code, type, convert (newtype, targ0),
6161 convert (newtype, targ1)));
6163 /* (-a) CMP (-b) -> b CMP a */
6164 if (TREE_CODE (arg0) == NEGATE_EXPR
6165 && TREE_CODE (arg1) == NEGATE_EXPR)
6166 return fold (build (code, type, TREE_OPERAND (arg1, 0),
6167 TREE_OPERAND (arg0, 0)));
6168 /* (-a) CMP CST -> a swap(CMP) (-CST) */
6169 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == REAL_CST)
6172 (swap_tree_comparison (code), type,
6173 TREE_OPERAND (arg0, 0),
6174 build_real (TREE_TYPE (arg1),
6175 REAL_VALUE_NEGATE (TREE_REAL_CST (arg1)))));
6176 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
6177 /* a CMP (-0) -> a CMP 0 */
6178 if (TREE_CODE (arg1) == REAL_CST
6179 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (arg1)))
6180 return fold (build (code, type, arg0,
6181 build_real (TREE_TYPE (arg1), dconst0)));
6183 /* If this is a comparison of a real constant with a PLUS_EXPR
6184 or a MINUS_EXPR of a real constant, we can convert it into a
6185 comparison with a revised real constant as long as no overflow
6186 occurs when unsafe_math_optimizations are enabled. */
6187 if (flag_unsafe_math_optimizations
6188 && TREE_CODE (arg1) == REAL_CST
6189 && (TREE_CODE (arg0) == PLUS_EXPR
6190 || TREE_CODE (arg0) == MINUS_EXPR)
6191 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
6192 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
6193 ? MINUS_EXPR : PLUS_EXPR,
6194 arg1, TREE_OPERAND (arg0, 1), 0))
6195 && ! TREE_CONSTANT_OVERFLOW (tem))
6196 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6199 /* Convert foo++ == CONST into ++foo == CONST + INCR.
6200 First, see if one arg is constant; find the constant arg
6201 and the other one. */
6203 tree constop = 0, varop = NULL_TREE;
6204 int constopnum = -1;
6206 if (TREE_CONSTANT (arg1))
6207 constopnum = 1, constop = arg1, varop = arg0;
6208 if (TREE_CONSTANT (arg0))
6209 constopnum = 0, constop = arg0, varop = arg1;
6211 if (constop && TREE_CODE (varop) == POSTINCREMENT_EXPR)
6213 /* This optimization is invalid for ordered comparisons
6214 if CONST+INCR overflows or if foo+incr might overflow.
6215 This optimization is invalid for floating point due to rounding.
6216 For pointer types we assume overflow doesn't happen. */
6217 if (POINTER_TYPE_P (TREE_TYPE (varop))
6218 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
6219 && (code == EQ_EXPR || code == NE_EXPR)))
6222 = fold (build (PLUS_EXPR, TREE_TYPE (varop),
6223 constop, TREE_OPERAND (varop, 1)));
6225 /* Do not overwrite the current varop to be a preincrement,
6226 create a new node so that we won't confuse our caller who
6227 might create trees and throw them away, reusing the
6228 arguments that they passed to build. This shows up in
6229 the THEN or ELSE parts of ?: being postincrements. */
6230 varop = build (PREINCREMENT_EXPR, TREE_TYPE (varop),
6231 TREE_OPERAND (varop, 0),
6232 TREE_OPERAND (varop, 1));
6234 /* If VAROP is a reference to a bitfield, we must mask
6235 the constant by the width of the field. */
6236 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
6237 && DECL_BIT_FIELD(TREE_OPERAND
6238 (TREE_OPERAND (varop, 0), 1)))
6241 = TREE_INT_CST_LOW (DECL_SIZE
6243 (TREE_OPERAND (varop, 0), 1)));
6244 tree mask, unsigned_type;
6245 unsigned int precision;
6246 tree folded_compare;
6248 /* First check whether the comparison would come out
6249 always the same. If we don't do that we would
6250 change the meaning with the masking. */
6251 if (constopnum == 0)
6252 folded_compare = fold (build (code, type, constop,
6253 TREE_OPERAND (varop, 0)));
6255 folded_compare = fold (build (code, type,
6256 TREE_OPERAND (varop, 0),
6258 if (integer_zerop (folded_compare)
6259 || integer_onep (folded_compare))
6260 return omit_one_operand (type, folded_compare, varop);
6262 unsigned_type = (*lang_hooks.types.type_for_size)(size, 1);
6263 precision = TYPE_PRECISION (unsigned_type);
6264 mask = build_int_2 (~0, ~0);
6265 TREE_TYPE (mask) = unsigned_type;
6266 force_fit_type (mask, 0);
6267 mask = const_binop (RSHIFT_EXPR, mask,
6268 size_int (precision - size), 0);
6269 newconst = fold (build (BIT_AND_EXPR,
6270 TREE_TYPE (varop), newconst,
6271 convert (TREE_TYPE (varop),
6275 t = build (code, type,
6276 (constopnum == 0) ? newconst : varop,
6277 (constopnum == 1) ? newconst : varop);
6281 else if (constop && TREE_CODE (varop) == POSTDECREMENT_EXPR)
6283 if (POINTER_TYPE_P (TREE_TYPE (varop))
6284 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
6285 && (code == EQ_EXPR || code == NE_EXPR)))
6288 = fold (build (MINUS_EXPR, TREE_TYPE (varop),
6289 constop, TREE_OPERAND (varop, 1)));
6291 /* Do not overwrite the current varop to be a predecrement,
6292 create a new node so that we won't confuse our caller who
6293 might create trees and throw them away, reusing the
6294 arguments that they passed to build. This shows up in
6295 the THEN or ELSE parts of ?: being postdecrements. */
6296 varop = build (PREDECREMENT_EXPR, TREE_TYPE (varop),
6297 TREE_OPERAND (varop, 0),
6298 TREE_OPERAND (varop, 1));
6300 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
6301 && DECL_BIT_FIELD(TREE_OPERAND
6302 (TREE_OPERAND (varop, 0), 1)))
6305 = TREE_INT_CST_LOW (DECL_SIZE
6307 (TREE_OPERAND (varop, 0), 1)));
6308 tree mask, unsigned_type;
6309 unsigned int precision;
6310 tree folded_compare;
6312 if (constopnum == 0)
6313 folded_compare = fold (build (code, type, constop,
6314 TREE_OPERAND (varop, 0)));
6316 folded_compare = fold (build (code, type,
6317 TREE_OPERAND (varop, 0),
6319 if (integer_zerop (folded_compare)
6320 || integer_onep (folded_compare))
6321 return omit_one_operand (type, folded_compare, varop);
6323 unsigned_type = (*lang_hooks.types.type_for_size)(size, 1);
6324 precision = TYPE_PRECISION (unsigned_type);
6325 mask = build_int_2 (~0, ~0);
6326 TREE_TYPE (mask) = TREE_TYPE (varop);
6327 force_fit_type (mask, 0);
6328 mask = const_binop (RSHIFT_EXPR, mask,
6329 size_int (precision - size), 0);
6330 newconst = fold (build (BIT_AND_EXPR,
6331 TREE_TYPE (varop), newconst,
6332 convert (TREE_TYPE (varop),
6336 t = build (code, type,
6337 (constopnum == 0) ? newconst : varop,
6338 (constopnum == 1) ? newconst : varop);
6344 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
6345 This transformation affects the cases which are handled in later
6346 optimizations involving comparisons with non-negative constants. */
6347 if (TREE_CODE (arg1) == INTEGER_CST
6348 && TREE_CODE (arg0) != INTEGER_CST
6349 && tree_int_cst_sgn (arg1) > 0)
6355 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6356 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6361 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6362 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6370 /* Comparisons with the highest or lowest possible integer of
6371 the specified size will have known values. */
6373 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1)));
6375 if (TREE_CODE (arg1) == INTEGER_CST
6376 && ! TREE_CONSTANT_OVERFLOW (arg1)
6377 && width <= HOST_BITS_PER_WIDE_INT
6378 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
6379 || POINTER_TYPE_P (TREE_TYPE (arg1))))
6381 unsigned HOST_WIDE_INT signed_max;
6382 unsigned HOST_WIDE_INT max, min;
6384 signed_max = ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1;
6386 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
6388 max = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
6394 min = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
6397 if (TREE_INT_CST_HIGH (arg1) == 0
6398 && TREE_INT_CST_LOW (arg1) == max)
6402 return omit_one_operand (type,
6403 convert (type, integer_zero_node),
6407 TREE_SET_CODE (t, EQ_EXPR);
6410 return omit_one_operand (type,
6411 convert (type, integer_one_node),
6415 TREE_SET_CODE (t, NE_EXPR);
6418 /* The GE_EXPR and LT_EXPR cases above are not normally
6419 reached because of previous transformations. */
6424 else if (TREE_INT_CST_HIGH (arg1) == 0
6425 && TREE_INT_CST_LOW (arg1) == max - 1)
6430 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
6431 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6435 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
6436 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6441 else if (TREE_INT_CST_HIGH (arg1) == (min ? -1 : 0)
6442 && TREE_INT_CST_LOW (arg1) == min)
6446 return omit_one_operand (type,
6447 convert (type, integer_zero_node),
6451 TREE_SET_CODE (t, EQ_EXPR);
6455 return omit_one_operand (type,
6456 convert (type, integer_one_node),
6460 TREE_SET_CODE (t, NE_EXPR);
6466 else if (TREE_INT_CST_HIGH (arg1) == (min ? -1 : 0)
6467 && TREE_INT_CST_LOW (arg1) == min + 1)
6472 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6473 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6477 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6478 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6484 else if (TREE_INT_CST_HIGH (arg1) == 0
6485 && TREE_INT_CST_LOW (arg1) == signed_max
6486 && TREE_UNSIGNED (TREE_TYPE (arg1))
6487 /* signed_type does not work on pointer types. */
6488 && INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
6490 /* The following case also applies to X < signed_max+1
6491 and X >= signed_max+1 because previous transformations. */
6492 if (code == LE_EXPR || code == GT_EXPR)
6495 st0 = (*lang_hooks.types.signed_type) (TREE_TYPE (arg0));
6496 st1 = (*lang_hooks.types.signed_type) (TREE_TYPE (arg1));
6498 (build (code == LE_EXPR ? GE_EXPR: LT_EXPR,
6499 type, convert (st0, arg0),
6500 convert (st1, integer_zero_node)));
6506 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
6507 a MINUS_EXPR of a constant, we can convert it into a comparison with
6508 a revised constant as long as no overflow occurs. */
6509 if ((code == EQ_EXPR || code == NE_EXPR)
6510 && TREE_CODE (arg1) == INTEGER_CST
6511 && (TREE_CODE (arg0) == PLUS_EXPR
6512 || TREE_CODE (arg0) == MINUS_EXPR)
6513 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6514 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
6515 ? MINUS_EXPR : PLUS_EXPR,
6516 arg1, TREE_OPERAND (arg0, 1), 0))
6517 && ! TREE_CONSTANT_OVERFLOW (tem))
6518 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6520 /* Similarly for a NEGATE_EXPR. */
6521 else if ((code == EQ_EXPR || code == NE_EXPR)
6522 && TREE_CODE (arg0) == NEGATE_EXPR
6523 && TREE_CODE (arg1) == INTEGER_CST
6524 && 0 != (tem = negate_expr (arg1))
6525 && TREE_CODE (tem) == INTEGER_CST
6526 && ! TREE_CONSTANT_OVERFLOW (tem))
6527 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6529 /* If we have X - Y == 0, we can convert that to X == Y and similarly
6530 for !=. Don't do this for ordered comparisons due to overflow. */
6531 else if ((code == NE_EXPR || code == EQ_EXPR)
6532 && integer_zerop (arg1) && TREE_CODE (arg0) == MINUS_EXPR)
6533 return fold (build (code, type,
6534 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1)));
6536 /* If we are widening one operand of an integer comparison,
6537 see if the other operand is similarly being widened. Perhaps we
6538 can do the comparison in the narrower type. */
6539 else if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
6540 && TREE_CODE (arg0) == NOP_EXPR
6541 && (tem = get_unwidened (arg0, NULL_TREE)) != arg0
6542 && (t1 = get_unwidened (arg1, TREE_TYPE (tem))) != 0
6543 && (TREE_TYPE (t1) == TREE_TYPE (tem)
6544 || (TREE_CODE (t1) == INTEGER_CST
6545 && int_fits_type_p (t1, TREE_TYPE (tem)))))
6546 return fold (build (code, type, tem, convert (TREE_TYPE (tem), t1)));
6548 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
6549 constant, we can simplify it. */
6550 else if (TREE_CODE (arg1) == INTEGER_CST
6551 && (TREE_CODE (arg0) == MIN_EXPR
6552 || TREE_CODE (arg0) == MAX_EXPR)
6553 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
6554 return optimize_minmax_comparison (t);
6556 /* If we are comparing an ABS_EXPR with a constant, we can
6557 convert all the cases into explicit comparisons, but they may
6558 well not be faster than doing the ABS and one comparison.
6559 But ABS (X) <= C is a range comparison, which becomes a subtraction
6560 and a comparison, and is probably faster. */
6561 else if (code == LE_EXPR && TREE_CODE (arg1) == INTEGER_CST
6562 && TREE_CODE (arg0) == ABS_EXPR
6563 && ! TREE_SIDE_EFFECTS (arg0)
6564 && (0 != (tem = negate_expr (arg1)))
6565 && TREE_CODE (tem) == INTEGER_CST
6566 && ! TREE_CONSTANT_OVERFLOW (tem))
6567 return fold (build (TRUTH_ANDIF_EXPR, type,
6568 build (GE_EXPR, type, TREE_OPERAND (arg0, 0), tem),
6569 build (LE_EXPR, type,
6570 TREE_OPERAND (arg0, 0), arg1)));
6572 /* If this is an EQ or NE comparison with zero and ARG0 is
6573 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
6574 two operations, but the latter can be done in one less insn
6575 on machines that have only two-operand insns or on which a
6576 constant cannot be the first operand. */
6577 if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR)
6578 && TREE_CODE (arg0) == BIT_AND_EXPR)
6580 if (TREE_CODE (TREE_OPERAND (arg0, 0)) == LSHIFT_EXPR
6581 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 0), 0)))
6583 fold (build (code, type,
6584 build (BIT_AND_EXPR, TREE_TYPE (arg0),
6586 TREE_TYPE (TREE_OPERAND (arg0, 0)),
6587 TREE_OPERAND (arg0, 1),
6588 TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)),
6589 convert (TREE_TYPE (arg0),
6592 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
6593 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
6595 fold (build (code, type,
6596 build (BIT_AND_EXPR, TREE_TYPE (arg0),
6598 TREE_TYPE (TREE_OPERAND (arg0, 1)),
6599 TREE_OPERAND (arg0, 0),
6600 TREE_OPERAND (TREE_OPERAND (arg0, 1), 1)),
6601 convert (TREE_TYPE (arg0),
6606 /* If this is an NE or EQ comparison of zero against the result of a
6607 signed MOD operation whose second operand is a power of 2, make
6608 the MOD operation unsigned since it is simpler and equivalent. */
6609 if ((code == NE_EXPR || code == EQ_EXPR)
6610 && integer_zerop (arg1)
6611 && ! TREE_UNSIGNED (TREE_TYPE (arg0))
6612 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
6613 || TREE_CODE (arg0) == CEIL_MOD_EXPR
6614 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
6615 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
6616 && integer_pow2p (TREE_OPERAND (arg0, 1)))
6618 tree newtype = (*lang_hooks.types.unsigned_type) (TREE_TYPE (arg0));
6619 tree newmod = build (TREE_CODE (arg0), newtype,
6620 convert (newtype, TREE_OPERAND (arg0, 0)),
6621 convert (newtype, TREE_OPERAND (arg0, 1)));
6623 return build (code, type, newmod, convert (newtype, arg1));
6626 /* If this is an NE comparison of zero with an AND of one, remove the
6627 comparison since the AND will give the correct value. */
6628 if (code == NE_EXPR && integer_zerop (arg1)
6629 && TREE_CODE (arg0) == BIT_AND_EXPR
6630 && integer_onep (TREE_OPERAND (arg0, 1)))
6631 return convert (type, arg0);
6633 /* If we have (A & C) == C where C is a power of 2, convert this into
6634 (A & C) != 0. Similarly for NE_EXPR. */
6635 if ((code == EQ_EXPR || code == NE_EXPR)
6636 && TREE_CODE (arg0) == BIT_AND_EXPR
6637 && integer_pow2p (TREE_OPERAND (arg0, 1))
6638 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
6639 return fold (build (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
6640 arg0, integer_zero_node));
6642 /* If we have (A & C) != 0 where C is the sign bit of A, convert
6643 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
6644 if ((code == EQ_EXPR || code == NE_EXPR)
6645 && TREE_CODE (arg0) == BIT_AND_EXPR
6646 && integer_zerop (arg1))
6648 tree arg00 = sign_bit_p (TREE_OPERAND (arg0, 0),
6649 TREE_OPERAND (arg0, 1));
6650 if (arg00 != NULL_TREE)
6652 tree stype = (*lang_hooks.types.signed_type) (TREE_TYPE (arg00));
6653 return fold (build (code == EQ_EXPR ? GE_EXPR : LT_EXPR, type,
6654 convert (stype, arg00),
6655 convert (stype, integer_zero_node)));
6659 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
6660 and similarly for >= into !=. */
6661 if ((code == LT_EXPR || code == GE_EXPR)
6662 && TREE_UNSIGNED (TREE_TYPE (arg0))
6663 && TREE_CODE (arg1) == LSHIFT_EXPR
6664 && integer_onep (TREE_OPERAND (arg1, 0)))
6665 return build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
6666 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
6667 TREE_OPERAND (arg1, 1)),
6668 convert (TREE_TYPE (arg0), integer_zero_node));
6670 else if ((code == LT_EXPR || code == GE_EXPR)
6671 && TREE_UNSIGNED (TREE_TYPE (arg0))
6672 && (TREE_CODE (arg1) == NOP_EXPR
6673 || TREE_CODE (arg1) == CONVERT_EXPR)
6674 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
6675 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
6677 build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
6678 convert (TREE_TYPE (arg0),
6679 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
6680 TREE_OPERAND (TREE_OPERAND (arg1, 0), 1))),
6681 convert (TREE_TYPE (arg0), integer_zero_node));
6683 /* Simplify comparison of something with itself. (For IEEE
6684 floating-point, we can only do some of these simplifications.) */
6685 if (operand_equal_p (arg0, arg1, 0))
6692 if (! FLOAT_TYPE_P (TREE_TYPE (arg0)))
6693 return constant_boolean_node (1, type);
6695 TREE_SET_CODE (t, code);
6699 /* For NE, we can only do this simplification if integer. */
6700 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
6702 /* ... fall through ... */
6705 return constant_boolean_node (0, type);
6711 /* If we are comparing an expression that just has comparisons
6712 of two integer values, arithmetic expressions of those comparisons,
6713 and constants, we can simplify it. There are only three cases
6714 to check: the two values can either be equal, the first can be
6715 greater, or the second can be greater. Fold the expression for
6716 those three values. Since each value must be 0 or 1, we have
6717 eight possibilities, each of which corresponds to the constant 0
6718 or 1 or one of the six possible comparisons.
6720 This handles common cases like (a > b) == 0 but also handles
6721 expressions like ((x > y) - (y > x)) > 0, which supposedly
6722 occur in macroized code. */
6724 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
6726 tree cval1 = 0, cval2 = 0;
6729 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
6730 /* Don't handle degenerate cases here; they should already
6731 have been handled anyway. */
6732 && cval1 != 0 && cval2 != 0
6733 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
6734 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
6735 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
6736 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
6737 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
6738 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
6739 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
6741 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
6742 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
6744 /* We can't just pass T to eval_subst in case cval1 or cval2
6745 was the same as ARG1. */
6748 = fold (build (code, type,
6749 eval_subst (arg0, cval1, maxval, cval2, minval),
6752 = fold (build (code, type,
6753 eval_subst (arg0, cval1, maxval, cval2, maxval),
6756 = fold (build (code, type,
6757 eval_subst (arg0, cval1, minval, cval2, maxval),
6760 /* All three of these results should be 0 or 1. Confirm they
6761 are. Then use those values to select the proper code
6764 if ((integer_zerop (high_result)
6765 || integer_onep (high_result))
6766 && (integer_zerop (equal_result)
6767 || integer_onep (equal_result))
6768 && (integer_zerop (low_result)
6769 || integer_onep (low_result)))
6771 /* Make a 3-bit mask with the high-order bit being the
6772 value for `>', the next for '=', and the low for '<'. */
6773 switch ((integer_onep (high_result) * 4)
6774 + (integer_onep (equal_result) * 2)
6775 + integer_onep (low_result))
6779 return omit_one_operand (type, integer_zero_node, arg0);
6800 return omit_one_operand (type, integer_one_node, arg0);
6803 t = build (code, type, cval1, cval2);
6805 return save_expr (t);
6812 /* If this is a comparison of a field, we may be able to simplify it. */
6813 if (((TREE_CODE (arg0) == COMPONENT_REF
6814 && (*lang_hooks.can_use_bit_fields_p) ())
6815 || TREE_CODE (arg0) == BIT_FIELD_REF)
6816 && (code == EQ_EXPR || code == NE_EXPR)
6817 /* Handle the constant case even without -O
6818 to make sure the warnings are given. */
6819 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
6821 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
6825 /* If this is a comparison of complex values and either or both sides
6826 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
6827 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
6828 This may prevent needless evaluations. */
6829 if ((code == EQ_EXPR || code == NE_EXPR)
6830 && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
6831 && (TREE_CODE (arg0) == COMPLEX_EXPR
6832 || TREE_CODE (arg1) == COMPLEX_EXPR
6833 || TREE_CODE (arg0) == COMPLEX_CST
6834 || TREE_CODE (arg1) == COMPLEX_CST))
6836 tree subtype = TREE_TYPE (TREE_TYPE (arg0));
6837 tree real0, imag0, real1, imag1;
6839 arg0 = save_expr (arg0);
6840 arg1 = save_expr (arg1);
6841 real0 = fold (build1 (REALPART_EXPR, subtype, arg0));
6842 imag0 = fold (build1 (IMAGPART_EXPR, subtype, arg0));
6843 real1 = fold (build1 (REALPART_EXPR, subtype, arg1));
6844 imag1 = fold (build1 (IMAGPART_EXPR, subtype, arg1));
6846 return fold (build ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR
6849 fold (build (code, type, real0, real1)),
6850 fold (build (code, type, imag0, imag1))));
6853 /* Optimize comparisons of strlen vs zero to a compare of the
6854 first character of the string vs zero. To wit,
6855 strlen(ptr) == 0 => *ptr == 0
6856 strlen(ptr) != 0 => *ptr != 0
6857 Other cases should reduce to one of these two (or a constant)
6858 due to the return value of strlen being unsigned. */
6859 if ((code == EQ_EXPR || code == NE_EXPR)
6860 && integer_zerop (arg1)
6861 && TREE_CODE (arg0) == CALL_EXPR
6862 && TREE_CODE (TREE_OPERAND (arg0, 0)) == ADDR_EXPR)
6864 tree fndecl = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
6867 if (TREE_CODE (fndecl) == FUNCTION_DECL
6868 && DECL_BUILT_IN (fndecl)
6869 && DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_MD
6870 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
6871 && (arglist = TREE_OPERAND (arg0, 1))
6872 && TREE_CODE (TREE_TYPE (TREE_VALUE (arglist))) == POINTER_TYPE
6873 && ! TREE_CHAIN (arglist))
6874 return fold (build (code, type,
6875 build1 (INDIRECT_REF, char_type_node,
6876 TREE_VALUE(arglist)),
6877 integer_zero_node));
6880 /* From here on, the only cases we handle are when the result is
6881 known to be a constant.
6883 To compute GT, swap the arguments and do LT.
6884 To compute GE, do LT and invert the result.
6885 To compute LE, swap the arguments, do LT and invert the result.
6886 To compute NE, do EQ and invert the result.
6888 Therefore, the code below must handle only EQ and LT. */
6890 if (code == LE_EXPR || code == GT_EXPR)
6892 tem = arg0, arg0 = arg1, arg1 = tem;
6893 code = swap_tree_comparison (code);
6896 /* Note that it is safe to invert for real values here because we
6897 will check below in the one case that it matters. */
6901 if (code == NE_EXPR || code == GE_EXPR)
6904 code = invert_tree_comparison (code);
6907 /* Compute a result for LT or EQ if args permit;
6908 otherwise return T. */
6909 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
6911 if (code == EQ_EXPR)
6912 t1 = build_int_2 (tree_int_cst_equal (arg0, arg1), 0);
6914 t1 = build_int_2 ((TREE_UNSIGNED (TREE_TYPE (arg0))
6915 ? INT_CST_LT_UNSIGNED (arg0, arg1)
6916 : INT_CST_LT (arg0, arg1)),
6920 #if 0 /* This is no longer useful, but breaks some real code. */
6921 /* Assume a nonexplicit constant cannot equal an explicit one,
6922 since such code would be undefined anyway.
6923 Exception: on sysvr4, using #pragma weak,
6924 a label can come out as 0. */
6925 else if (TREE_CODE (arg1) == INTEGER_CST
6926 && !integer_zerop (arg1)
6927 && TREE_CONSTANT (arg0)
6928 && TREE_CODE (arg0) == ADDR_EXPR
6930 t1 = build_int_2 (0, 0);
6932 /* Two real constants can be compared explicitly. */
6933 else if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
6935 /* If either operand is a NaN, the result is false with two
6936 exceptions: First, an NE_EXPR is true on NaNs, but that case
6937 is already handled correctly since we will be inverting the
6938 result for NE_EXPR. Second, if we had inverted a LE_EXPR
6939 or a GE_EXPR into a LT_EXPR, we must return true so that it
6940 will be inverted into false. */
6942 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
6943 || REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
6944 t1 = build_int_2 (invert && code == LT_EXPR, 0);
6946 else if (code == EQ_EXPR)
6947 t1 = build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (arg0),
6948 TREE_REAL_CST (arg1)),
6951 t1 = build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (arg0),
6952 TREE_REAL_CST (arg1)),
6956 if (t1 == NULL_TREE)
6960 TREE_INT_CST_LOW (t1) ^= 1;
6962 TREE_TYPE (t1) = type;
6963 if (TREE_CODE (type) == BOOLEAN_TYPE)
6964 return (*lang_hooks.truthvalue_conversion) (t1);
6968 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
6969 so all simple results must be passed through pedantic_non_lvalue. */
6970 if (TREE_CODE (arg0) == INTEGER_CST)
6971 return pedantic_non_lvalue
6972 (TREE_OPERAND (t, (integer_zerop (arg0) ? 2 : 1)));
6973 else if (operand_equal_p (arg1, TREE_OPERAND (expr, 2), 0))
6974 return pedantic_omit_one_operand (type, arg1, arg0);
6976 /* If the second operand is zero, invert the comparison and swap
6977 the second and third operands. Likewise if the second operand
6978 is constant and the third is not or if the third operand is
6979 equivalent to the first operand of the comparison. */
6981 if (integer_zerop (arg1)
6982 || (TREE_CONSTANT (arg1) && ! TREE_CONSTANT (TREE_OPERAND (t, 2)))
6983 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
6984 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
6985 TREE_OPERAND (t, 2),
6986 TREE_OPERAND (arg0, 1))))
6988 /* See if this can be inverted. If it can't, possibly because
6989 it was a floating-point inequality comparison, don't do
6991 tem = invert_truthvalue (arg0);
6993 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
6995 t = build (code, type, tem,
6996 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
6998 /* arg1 should be the first argument of the new T. */
6999 arg1 = TREE_OPERAND (t, 1);
7004 /* If we have A op B ? A : C, we may be able to convert this to a
7005 simpler expression, depending on the operation and the values
7006 of B and C. Signed zeros prevent all of these transformations,
7007 for reasons given above each one. */
7009 if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
7010 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
7011 arg1, TREE_OPERAND (arg0, 1))
7012 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
7014 tree arg2 = TREE_OPERAND (t, 2);
7015 enum tree_code comp_code = TREE_CODE (arg0);
7019 /* If we have A op 0 ? A : -A, consider applying the following
7022 A == 0? A : -A same as -A
7023 A != 0? A : -A same as A
7024 A >= 0? A : -A same as abs (A)
7025 A > 0? A : -A same as abs (A)
7026 A <= 0? A : -A same as -abs (A)
7027 A < 0? A : -A same as -abs (A)
7029 None of these transformations work for modes with signed
7030 zeros. If A is +/-0, the first two transformations will
7031 change the sign of the result (from +0 to -0, or vice
7032 versa). The last four will fix the sign of the result,
7033 even though the original expressions could be positive or
7034 negative, depending on the sign of A.
7036 Note that all these transformations are correct if A is
7037 NaN, since the two alternatives (A and -A) are also NaNs. */
7038 if ((FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 1)))
7039 ? real_zerop (TREE_OPERAND (arg0, 1))
7040 : integer_zerop (TREE_OPERAND (arg0, 1)))
7041 && TREE_CODE (arg2) == NEGATE_EXPR
7042 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
7050 (convert (TREE_TYPE (TREE_OPERAND (t, 1)),
7053 return pedantic_non_lvalue (convert (type, arg1));
7056 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
7057 arg1 = convert ((*lang_hooks.types.signed_type)
7058 (TREE_TYPE (arg1)), arg1);
7059 return pedantic_non_lvalue
7060 (convert (type, fold (build1 (ABS_EXPR,
7061 TREE_TYPE (arg1), arg1))));
7064 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
7065 arg1 = convert ((lang_hooks.types.signed_type)
7066 (TREE_TYPE (arg1)), arg1);
7067 return pedantic_non_lvalue
7068 (negate_expr (convert (type,
7069 fold (build1 (ABS_EXPR,
7076 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
7077 A == 0 ? A : 0 is always 0 unless A is -0. Note that
7078 both transformations are correct when A is NaN: A != 0
7079 is then true, and A == 0 is false. */
7081 if (integer_zerop (TREE_OPERAND (arg0, 1)) && integer_zerop (arg2))
7083 if (comp_code == NE_EXPR)
7084 return pedantic_non_lvalue (convert (type, arg1));
7085 else if (comp_code == EQ_EXPR)
7086 return pedantic_non_lvalue (convert (type, integer_zero_node));
7089 /* Try some transformations of A op B ? A : B.
7091 A == B? A : B same as B
7092 A != B? A : B same as A
7093 A >= B? A : B same as max (A, B)
7094 A > B? A : B same as max (B, A)
7095 A <= B? A : B same as min (A, B)
7096 A < B? A : B same as min (B, A)
7098 As above, these transformations don't work in the presence
7099 of signed zeros. For example, if A and B are zeros of
7100 opposite sign, the first two transformations will change
7101 the sign of the result. In the last four, the original
7102 expressions give different results for (A=+0, B=-0) and
7103 (A=-0, B=+0), but the transformed expressions do not.
7105 The first two transformations are correct if either A or B
7106 is a NaN. In the first transformation, the condition will
7107 be false, and B will indeed be chosen. In the case of the
7108 second transformation, the condition A != B will be true,
7109 and A will be chosen.
7111 The conversions to max() and min() are not correct if B is
7112 a number and A is not. The conditions in the original
7113 expressions will be false, so all four give B. The min()
7114 and max() versions would give a NaN instead. */
7115 if (operand_equal_for_comparison_p (TREE_OPERAND (arg0, 1),
7116 arg2, TREE_OPERAND (arg0, 0)))
7118 tree comp_op0 = TREE_OPERAND (arg0, 0);
7119 tree comp_op1 = TREE_OPERAND (arg0, 1);
7120 tree comp_type = TREE_TYPE (comp_op0);
7122 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
7123 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
7133 return pedantic_non_lvalue (convert (type, arg2));
7135 return pedantic_non_lvalue (convert (type, arg1));
7138 /* In C++ a ?: expression can be an lvalue, so put the
7139 operand which will be used if they are equal first
7140 so that we can convert this back to the
7141 corresponding COND_EXPR. */
7142 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
7143 return pedantic_non_lvalue
7144 (convert (type, fold (build (MIN_EXPR, comp_type,
7145 (comp_code == LE_EXPR
7146 ? comp_op0 : comp_op1),
7147 (comp_code == LE_EXPR
7148 ? comp_op1 : comp_op0)))));
7152 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
7153 return pedantic_non_lvalue
7154 (convert (type, fold (build (MAX_EXPR, comp_type,
7155 (comp_code == GE_EXPR
7156 ? comp_op0 : comp_op1),
7157 (comp_code == GE_EXPR
7158 ? comp_op1 : comp_op0)))));
7165 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
7166 we might still be able to simplify this. For example,
7167 if C1 is one less or one more than C2, this might have started
7168 out as a MIN or MAX and been transformed by this function.
7169 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
7171 if (INTEGRAL_TYPE_P (type)
7172 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7173 && TREE_CODE (arg2) == INTEGER_CST)
7177 /* We can replace A with C1 in this case. */
7178 arg1 = convert (type, TREE_OPERAND (arg0, 1));
7179 t = build (code, type, TREE_OPERAND (t, 0), arg1,
7180 TREE_OPERAND (t, 2));
7184 /* If C1 is C2 + 1, this is min(A, C2). */
7185 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
7186 && operand_equal_p (TREE_OPERAND (arg0, 1),
7187 const_binop (PLUS_EXPR, arg2,
7188 integer_one_node, 0), 1))
7189 return pedantic_non_lvalue
7190 (fold (build (MIN_EXPR, type, arg1, arg2)));
7194 /* If C1 is C2 - 1, this is min(A, C2). */
7195 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
7196 && operand_equal_p (TREE_OPERAND (arg0, 1),
7197 const_binop (MINUS_EXPR, arg2,
7198 integer_one_node, 0), 1))
7199 return pedantic_non_lvalue
7200 (fold (build (MIN_EXPR, type, arg1, arg2)));
7204 /* If C1 is C2 - 1, this is max(A, C2). */
7205 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
7206 && operand_equal_p (TREE_OPERAND (arg0, 1),
7207 const_binop (MINUS_EXPR, arg2,
7208 integer_one_node, 0), 1))
7209 return pedantic_non_lvalue
7210 (fold (build (MAX_EXPR, type, arg1, arg2)));
7214 /* If C1 is C2 + 1, this is max(A, C2). */
7215 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
7216 && operand_equal_p (TREE_OPERAND (arg0, 1),
7217 const_binop (PLUS_EXPR, arg2,
7218 integer_one_node, 0), 1))
7219 return pedantic_non_lvalue
7220 (fold (build (MAX_EXPR, type, arg1, arg2)));
7229 /* If the second operand is simpler than the third, swap them
7230 since that produces better jump optimization results. */
7231 if ((TREE_CONSTANT (arg1) || DECL_P (arg1)
7232 || TREE_CODE (arg1) == SAVE_EXPR)
7233 && ! (TREE_CONSTANT (TREE_OPERAND (t, 2))
7234 || DECL_P (TREE_OPERAND (t, 2))
7235 || TREE_CODE (TREE_OPERAND (t, 2)) == SAVE_EXPR))
7237 /* See if this can be inverted. If it can't, possibly because
7238 it was a floating-point inequality comparison, don't do
7240 tem = invert_truthvalue (arg0);
7242 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
7244 t = build (code, type, tem,
7245 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
7247 /* arg1 should be the first argument of the new T. */
7248 arg1 = TREE_OPERAND (t, 1);
7253 /* Convert A ? 1 : 0 to simply A. */
7254 if (integer_onep (TREE_OPERAND (t, 1))
7255 && integer_zerop (TREE_OPERAND (t, 2))
7256 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
7257 call to fold will try to move the conversion inside
7258 a COND, which will recurse. In that case, the COND_EXPR
7259 is probably the best choice, so leave it alone. */
7260 && type == TREE_TYPE (arg0))
7261 return pedantic_non_lvalue (arg0);
7263 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
7264 over COND_EXPR in cases such as floating point comparisons. */
7265 if (integer_zerop (TREE_OPERAND (t, 1))
7266 && integer_onep (TREE_OPERAND (t, 2))
7267 && truth_value_p (TREE_CODE (arg0)))
7268 return pedantic_non_lvalue (convert (type,
7269 invert_truthvalue (arg0)));
7271 /* Look for expressions of the form A & 2 ? 2 : 0. The result of this
7272 operation is simply A & 2. */
7274 if (integer_zerop (TREE_OPERAND (t, 2))
7275 && TREE_CODE (arg0) == NE_EXPR
7276 && integer_zerop (TREE_OPERAND (arg0, 1))
7277 && integer_pow2p (arg1)
7278 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
7279 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
7281 return pedantic_non_lvalue (convert (type, TREE_OPERAND (arg0, 0)));
7283 /* Convert A ? B : 0 into A && B if A and B are truth values. */
7284 if (integer_zerop (TREE_OPERAND (t, 2))
7285 && truth_value_p (TREE_CODE (arg0))
7286 && truth_value_p (TREE_CODE (arg1)))
7287 return pedantic_non_lvalue (fold (build (TRUTH_ANDIF_EXPR, type,
7290 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
7291 if (integer_onep (TREE_OPERAND (t, 2))
7292 && truth_value_p (TREE_CODE (arg0))
7293 && truth_value_p (TREE_CODE (arg1)))
7295 /* Only perform transformation if ARG0 is easily inverted. */
7296 tem = invert_truthvalue (arg0);
7297 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
7298 return pedantic_non_lvalue (fold (build (TRUTH_ORIF_EXPR, type,
7305 /* When pedantic, a compound expression can be neither an lvalue
7306 nor an integer constant expression. */
7307 if (TREE_SIDE_EFFECTS (arg0) || pedantic)
7309 /* Don't let (0, 0) be null pointer constant. */
7310 if (integer_zerop (arg1))
7311 return build1 (NOP_EXPR, type, arg1);
7312 return convert (type, arg1);
7316 return build_complex (type, arg0, arg1);
7320 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7322 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
7323 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
7324 TREE_OPERAND (arg0, 1));
7325 else if (TREE_CODE (arg0) == COMPLEX_CST)
7326 return TREE_REALPART (arg0);
7327 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7328 return fold (build (TREE_CODE (arg0), type,
7329 fold (build1 (REALPART_EXPR, type,
7330 TREE_OPERAND (arg0, 0))),
7331 fold (build1 (REALPART_EXPR,
7332 type, TREE_OPERAND (arg0, 1)))));
7336 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7337 return convert (type, integer_zero_node);
7338 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
7339 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
7340 TREE_OPERAND (arg0, 0));
7341 else if (TREE_CODE (arg0) == COMPLEX_CST)
7342 return TREE_IMAGPART (arg0);
7343 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7344 return fold (build (TREE_CODE (arg0), type,
7345 fold (build1 (IMAGPART_EXPR, type,
7346 TREE_OPERAND (arg0, 0))),
7347 fold (build1 (IMAGPART_EXPR, type,
7348 TREE_OPERAND (arg0, 1)))));
7351 /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
7353 case CLEANUP_POINT_EXPR:
7354 if (! has_cleanups (arg0))
7355 return TREE_OPERAND (t, 0);
7358 enum tree_code code0 = TREE_CODE (arg0);
7359 int kind0 = TREE_CODE_CLASS (code0);
7360 tree arg00 = TREE_OPERAND (arg0, 0);
7363 if (kind0 == '1' || code0 == TRUTH_NOT_EXPR)
7364 return fold (build1 (code0, type,
7365 fold (build1 (CLEANUP_POINT_EXPR,
7366 TREE_TYPE (arg00), arg00))));
7368 if (kind0 == '<' || kind0 == '2'
7369 || code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR
7370 || code0 == TRUTH_AND_EXPR || code0 == TRUTH_OR_EXPR
7371 || code0 == TRUTH_XOR_EXPR)
7373 arg01 = TREE_OPERAND (arg0, 1);
7375 if (TREE_CONSTANT (arg00)
7376 || ((code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR)
7377 && ! has_cleanups (arg00)))
7378 return fold (build (code0, type, arg00,
7379 fold (build1 (CLEANUP_POINT_EXPR,
7380 TREE_TYPE (arg01), arg01))));
7382 if (TREE_CONSTANT (arg01))
7383 return fold (build (code0, type,
7384 fold (build1 (CLEANUP_POINT_EXPR,
7385 TREE_TYPE (arg00), arg00)),
7393 /* Check for a built-in function. */
7394 if (TREE_CODE (TREE_OPERAND (expr, 0)) == ADDR_EXPR
7395 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (expr, 0), 0))
7397 && DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (expr, 0), 0)))
7399 tree tmp = fold_builtin (expr);
7407 } /* switch (code) */
7410 /* Determine if first argument is a multiple of second argument. Return 0 if
7411 it is not, or we cannot easily determined it to be.
7413 An example of the sort of thing we care about (at this point; this routine
7414 could surely be made more general, and expanded to do what the *_DIV_EXPR's
7415 fold cases do now) is discovering that
7417 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7423 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
7425 This code also handles discovering that
7427 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7429 is a multiple of 8 so we don't have to worry about dealing with a
7432 Note that we *look* inside a SAVE_EXPR only to determine how it was
7433 calculated; it is not safe for fold to do much of anything else with the
7434 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
7435 at run time. For example, the latter example above *cannot* be implemented
7436 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
7437 evaluation time of the original SAVE_EXPR is not necessarily the same at
7438 the time the new expression is evaluated. The only optimization of this
7439 sort that would be valid is changing
7441 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
7445 SAVE_EXPR (I) * SAVE_EXPR (J)
7447 (where the same SAVE_EXPR (J) is used in the original and the
7448 transformed version). */
7451 multiple_of_p (type, top, bottom)
7456 if (operand_equal_p (top, bottom, 0))
7459 if (TREE_CODE (type) != INTEGER_TYPE)
7462 switch (TREE_CODE (top))
7465 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
7466 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
7470 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
7471 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
7474 if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
7478 op1 = TREE_OPERAND (top, 1);
7479 /* const_binop may not detect overflow correctly,
7480 so check for it explicitly here. */
7481 if (TYPE_PRECISION (TREE_TYPE (size_one_node))
7482 > TREE_INT_CST_LOW (op1)
7483 && TREE_INT_CST_HIGH (op1) == 0
7484 && 0 != (t1 = convert (type,
7485 const_binop (LSHIFT_EXPR, size_one_node,
7487 && ! TREE_OVERFLOW (t1))
7488 return multiple_of_p (type, t1, bottom);
7493 /* Can't handle conversions from non-integral or wider integral type. */
7494 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
7495 || (TYPE_PRECISION (type)
7496 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
7499 /* .. fall through ... */
7502 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
7505 if (TREE_CODE (bottom) != INTEGER_CST
7506 || (TREE_UNSIGNED (type)
7507 && (tree_int_cst_sgn (top) < 0
7508 || tree_int_cst_sgn (bottom) < 0)))
7510 return integer_zerop (const_binop (TRUNC_MOD_EXPR,
7518 /* Return true if `t' is known to be non-negative. */
7521 tree_expr_nonnegative_p (t)
7524 switch (TREE_CODE (t))
7534 /* These are undefined at zero. This is true even if
7535 C[LT]Z_DEFINED_VALUE_AT_ZERO is set, since what we're
7536 computing here is a user-visible property. */
7540 return tree_int_cst_sgn (t) >= 0;
7541 case TRUNC_DIV_EXPR:
7543 case FLOOR_DIV_EXPR:
7544 case ROUND_DIV_EXPR:
7545 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
7546 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
7547 case TRUNC_MOD_EXPR:
7549 case FLOOR_MOD_EXPR:
7550 case ROUND_MOD_EXPR:
7551 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
7553 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
7554 && tree_expr_nonnegative_p (TREE_OPERAND (t, 2));
7556 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
7558 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
7559 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
7561 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
7562 || tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
7564 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
7566 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
7568 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
7569 case NON_LVALUE_EXPR:
7570 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
7572 return rtl_expr_nonnegative_p (RTL_EXPR_RTL (t));
7575 if (truth_value_p (TREE_CODE (t)))
7576 /* Truth values evaluate to 0 or 1, which is nonnegative. */
7579 /* We don't know sign of `t', so be conservative and return false. */
7584 /* Return true if `r' is known to be non-negative.
7585 Only handles constants at the moment. */
7588 rtl_expr_nonnegative_p (r)
7591 switch (GET_CODE (r))
7594 return INTVAL (r) >= 0;
7597 if (GET_MODE (r) == VOIDmode)
7598 return CONST_DOUBLE_HIGH (r) >= 0;
7606 units = CONST_VECTOR_NUNITS (r);
7608 for (i = 0; i < units; ++i)
7610 elt = CONST_VECTOR_ELT (r, i);
7611 if (!rtl_expr_nonnegative_p (elt))
7620 /* These are always nonnegative. */
7628 #include "gt-fold-const.h"