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,
3 1999, 2000 Free Software Foundation, Inc.
5 This file is part of GNU CC.
7 GNU CC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
12 GNU CC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GNU CC; see the file COPYING. If not, write to
19 the Free Software Foundation, 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
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. */
55 static void encode PARAMS ((HOST_WIDE_INT *,
56 unsigned HOST_WIDE_INT,
58 static void decode PARAMS ((HOST_WIDE_INT *,
59 unsigned HOST_WIDE_INT *,
61 static tree negate_expr PARAMS ((tree));
62 static tree split_tree PARAMS ((tree, enum tree_code, tree *, tree *,
64 static tree associate_trees PARAMS ((tree, tree, enum tree_code, tree));
65 static tree int_const_binop PARAMS ((enum tree_code, tree, tree, int, int));
66 static void const_binop_1 PARAMS ((PTR));
67 static tree const_binop PARAMS ((enum tree_code, tree, tree, int));
68 static void fold_convert_1 PARAMS ((PTR));
69 static tree fold_convert PARAMS ((tree, tree));
70 static enum tree_code invert_tree_comparison PARAMS ((enum tree_code));
71 static enum tree_code swap_tree_comparison PARAMS ((enum tree_code));
72 static int truth_value_p PARAMS ((enum tree_code));
73 static int operand_equal_for_comparison_p PARAMS ((tree, tree, tree));
74 static int twoval_comparison_p PARAMS ((tree, tree *, tree *, int *));
75 static tree eval_subst PARAMS ((tree, tree, tree, tree, tree));
76 static tree omit_one_operand PARAMS ((tree, tree, tree));
77 static tree pedantic_omit_one_operand PARAMS ((tree, tree, tree));
78 static tree distribute_bit_expr PARAMS ((enum tree_code, tree, tree, tree));
79 static tree make_bit_field_ref PARAMS ((tree, tree, int, int, int));
80 static tree optimize_bit_field_compare PARAMS ((enum tree_code, tree,
82 static tree decode_field_reference PARAMS ((tree, HOST_WIDE_INT *,
84 enum machine_mode *, int *,
85 int *, tree *, tree *));
86 static int all_ones_mask_p PARAMS ((tree, int));
87 static int simple_operand_p PARAMS ((tree));
88 static tree range_binop PARAMS ((enum tree_code, tree, tree, int,
90 static tree make_range PARAMS ((tree, int *, tree *, tree *));
91 static tree build_range_check PARAMS ((tree, tree, int, tree, tree));
92 static int merge_ranges PARAMS ((int *, tree *, tree *, int, tree, tree,
94 static tree fold_range_test PARAMS ((tree));
95 static tree unextend PARAMS ((tree, int, int, tree));
96 static tree fold_truthop PARAMS ((enum tree_code, tree, tree, tree));
97 static tree optimize_minmax_comparison PARAMS ((tree));
98 static tree extract_muldiv PARAMS ((tree, tree, enum tree_code, tree));
99 static tree strip_compound_expr PARAMS ((tree, tree));
100 static int multiple_of_p PARAMS ((tree, tree, tree));
101 static tree constant_boolean_node PARAMS ((int, tree));
102 static int count_cond PARAMS ((tree, int));
105 #define BRANCH_COST 1
108 #if defined(HOST_EBCDIC)
109 /* bit 8 is significant in EBCDIC */
110 #define CHARMASK 0xff
112 #define CHARMASK 0x7f
115 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
116 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
117 and SUM1. Then this yields nonzero if overflow occurred during the
120 Overflow occurs if A and B have the same sign, but A and SUM differ in
121 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
123 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
125 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
126 We do that by representing the two-word integer in 4 words, with only
127 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
128 number. The value of the word is LOWPART + HIGHPART * BASE. */
131 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
132 #define HIGHPART(x) \
133 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
134 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
136 /* Unpack a two-word integer into 4 words.
137 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
138 WORDS points to the array of HOST_WIDE_INTs. */
141 encode (words, low, hi)
142 HOST_WIDE_INT *words;
143 unsigned HOST_WIDE_INT low;
146 words[0] = LOWPART (low);
147 words[1] = HIGHPART (low);
148 words[2] = LOWPART (hi);
149 words[3] = HIGHPART (hi);
152 /* Pack an array of 4 words into a two-word integer.
153 WORDS points to the array of words.
154 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
157 decode (words, low, hi)
158 HOST_WIDE_INT *words;
159 unsigned HOST_WIDE_INT *low;
162 *low = words[0] + words[1] * BASE;
163 *hi = words[2] + words[3] * BASE;
166 /* Make the integer constant T valid for its type by setting to 0 or 1 all
167 the bits in the constant that don't belong in the type.
169 Return 1 if a signed overflow occurs, 0 otherwise. If OVERFLOW is
170 nonzero, a signed overflow has already occurred in calculating T, so
173 Make the real constant T valid for its type by calling CHECK_FLOAT_VALUE,
177 force_fit_type (t, overflow)
181 unsigned HOST_WIDE_INT low;
185 if (TREE_CODE (t) == REAL_CST)
187 #ifdef CHECK_FLOAT_VALUE
188 CHECK_FLOAT_VALUE (TYPE_MODE (TREE_TYPE (t)), TREE_REAL_CST (t),
194 else if (TREE_CODE (t) != INTEGER_CST)
197 low = TREE_INT_CST_LOW (t);
198 high = TREE_INT_CST_HIGH (t);
200 if (POINTER_TYPE_P (TREE_TYPE (t)))
203 prec = TYPE_PRECISION (TREE_TYPE (t));
205 /* First clear all bits that are beyond the type's precision. */
207 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
209 else if (prec > HOST_BITS_PER_WIDE_INT)
210 TREE_INT_CST_HIGH (t)
211 &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
214 TREE_INT_CST_HIGH (t) = 0;
215 if (prec < HOST_BITS_PER_WIDE_INT)
216 TREE_INT_CST_LOW (t) &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
219 /* Unsigned types do not suffer sign extension or overflow unless they
221 if (TREE_UNSIGNED (TREE_TYPE (t))
222 && ! (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
223 && TYPE_IS_SIZETYPE (TREE_TYPE (t))))
226 /* If the value's sign bit is set, extend the sign. */
227 if (prec != 2 * HOST_BITS_PER_WIDE_INT
228 && (prec > HOST_BITS_PER_WIDE_INT
229 ? 0 != (TREE_INT_CST_HIGH (t)
231 << (prec - HOST_BITS_PER_WIDE_INT - 1)))
232 : 0 != (TREE_INT_CST_LOW (t)
233 & ((unsigned HOST_WIDE_INT) 1 << (prec - 1)))))
235 /* Value is negative:
236 set to 1 all the bits that are outside this type's precision. */
237 if (prec > HOST_BITS_PER_WIDE_INT)
238 TREE_INT_CST_HIGH (t)
239 |= ((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
242 TREE_INT_CST_HIGH (t) = -1;
243 if (prec < HOST_BITS_PER_WIDE_INT)
244 TREE_INT_CST_LOW (t) |= ((unsigned HOST_WIDE_INT) (-1) << prec);
248 /* Return nonzero if signed overflow occurred. */
250 ((overflow | (low ^ TREE_INT_CST_LOW (t)) | (high ^ TREE_INT_CST_HIGH (t)))
254 /* Add two doubleword integers with doubleword result.
255 Each argument is given as two `HOST_WIDE_INT' pieces.
256 One argument is L1 and H1; the other, L2 and H2.
257 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
260 add_double (l1, h1, l2, h2, lv, hv)
261 unsigned HOST_WIDE_INT l1, l2;
262 HOST_WIDE_INT h1, h2;
263 unsigned HOST_WIDE_INT *lv;
266 unsigned HOST_WIDE_INT l;
270 h = h1 + h2 + (l < l1);
274 return OVERFLOW_SUM_SIGN (h1, h2, h);
277 /* Negate a doubleword integer with doubleword result.
278 Return nonzero if the operation overflows, assuming it's signed.
279 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
280 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
283 neg_double (l1, h1, lv, hv)
284 unsigned HOST_WIDE_INT l1;
286 unsigned HOST_WIDE_INT *lv;
293 return (*hv & h1) < 0;
303 /* Multiply two doubleword integers with doubleword result.
304 Return nonzero if the operation overflows, assuming it's signed.
305 Each argument is given as two `HOST_WIDE_INT' pieces.
306 One argument is L1 and H1; the other, L2 and H2.
307 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
310 mul_double (l1, h1, l2, h2, lv, hv)
311 unsigned HOST_WIDE_INT l1, l2;
312 HOST_WIDE_INT h1, h2;
313 unsigned HOST_WIDE_INT *lv;
316 HOST_WIDE_INT arg1[4];
317 HOST_WIDE_INT arg2[4];
318 HOST_WIDE_INT prod[4 * 2];
319 register unsigned HOST_WIDE_INT carry;
320 register int i, j, k;
321 unsigned HOST_WIDE_INT toplow, neglow;
322 HOST_WIDE_INT tophigh, neghigh;
324 encode (arg1, l1, h1);
325 encode (arg2, l2, h2);
327 bzero ((char *) prod, sizeof prod);
329 for (i = 0; i < 4; i++)
332 for (j = 0; j < 4; j++)
335 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
336 carry += arg1[i] * arg2[j];
337 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
339 prod[k] = LOWPART (carry);
340 carry = HIGHPART (carry);
345 decode (prod, lv, hv); /* This ignores prod[4] through prod[4*2-1] */
347 /* Check for overflow by calculating the top half of the answer in full;
348 it should agree with the low half's sign bit. */
349 decode (prod + 4, &toplow, &tophigh);
352 neg_double (l2, h2, &neglow, &neghigh);
353 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
357 neg_double (l1, h1, &neglow, &neghigh);
358 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
360 return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
363 /* Shift the doubleword integer in L1, H1 left by COUNT places
364 keeping only PREC bits of result.
365 Shift right if COUNT is negative.
366 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
367 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
370 lshift_double (l1, h1, count, prec, lv, hv, arith)
371 unsigned HOST_WIDE_INT l1;
372 HOST_WIDE_INT h1, count;
374 unsigned HOST_WIDE_INT *lv;
380 rshift_double (l1, h1, -count, prec, lv, hv, arith);
384 #ifdef SHIFT_COUNT_TRUNCATED
385 if (SHIFT_COUNT_TRUNCATED)
389 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
391 /* Shifting by the host word size is undefined according to the
392 ANSI standard, so we must handle this as a special case. */
396 else if (count >= HOST_BITS_PER_WIDE_INT)
398 *hv = l1 << (count - HOST_BITS_PER_WIDE_INT);
403 *hv = (((unsigned HOST_WIDE_INT) h1 << count)
404 | (l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
409 /* Shift the doubleword integer in L1, H1 right by COUNT places
410 keeping only PREC bits of result. COUNT must be positive.
411 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
412 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
415 rshift_double (l1, h1, count, prec, lv, hv, arith)
416 unsigned HOST_WIDE_INT l1;
417 HOST_WIDE_INT h1, count;
418 unsigned int prec ATTRIBUTE_UNUSED;
419 unsigned HOST_WIDE_INT *lv;
423 unsigned HOST_WIDE_INT signmask;
426 ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
429 #ifdef SHIFT_COUNT_TRUNCATED
430 if (SHIFT_COUNT_TRUNCATED)
434 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
436 /* Shifting by the host word size is undefined according to the
437 ANSI standard, so we must handle this as a special case. */
441 else if (count >= HOST_BITS_PER_WIDE_INT)
444 *lv = ((signmask << (2 * HOST_BITS_PER_WIDE_INT - count - 1) << 1)
445 | ((unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT)));
450 | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
451 *hv = ((signmask << (HOST_BITS_PER_WIDE_INT - count))
452 | ((unsigned HOST_WIDE_INT) h1 >> count));
456 /* Rotate the doubleword integer in L1, H1 left by COUNT places
457 keeping only PREC bits of result.
458 Rotate right if COUNT is negative.
459 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
462 lrotate_double (l1, h1, count, prec, lv, hv)
463 unsigned HOST_WIDE_INT l1;
464 HOST_WIDE_INT h1, count;
466 unsigned HOST_WIDE_INT *lv;
469 unsigned HOST_WIDE_INT s1l, s2l;
470 HOST_WIDE_INT s1h, s2h;
476 lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
477 rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
482 /* Rotate the doubleword integer in L1, H1 left by COUNT places
483 keeping only PREC bits of result. COUNT must be positive.
484 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
487 rrotate_double (l1, h1, count, prec, lv, hv)
488 unsigned HOST_WIDE_INT l1;
489 HOST_WIDE_INT h1, count;
491 unsigned HOST_WIDE_INT *lv;
494 unsigned HOST_WIDE_INT s1l, s2l;
495 HOST_WIDE_INT s1h, s2h;
501 rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
502 lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
507 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
508 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
509 CODE is a tree code for a kind of division, one of
510 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
512 It controls how the quotient is rounded to a integer.
513 Return nonzero if the operation overflows.
514 UNS nonzero says do unsigned division. */
517 div_and_round_double (code, uns,
518 lnum_orig, hnum_orig, lden_orig, hden_orig,
519 lquo, hquo, lrem, hrem)
522 unsigned HOST_WIDE_INT lnum_orig; /* num == numerator == dividend */
523 HOST_WIDE_INT hnum_orig;
524 unsigned HOST_WIDE_INT lden_orig; /* den == denominator == divisor */
525 HOST_WIDE_INT hden_orig;
526 unsigned HOST_WIDE_INT *lquo, *lrem;
527 HOST_WIDE_INT *hquo, *hrem;
530 HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
531 HOST_WIDE_INT den[4], quo[4];
533 unsigned HOST_WIDE_INT work;
534 unsigned HOST_WIDE_INT carry = 0;
535 unsigned HOST_WIDE_INT lnum = lnum_orig;
536 HOST_WIDE_INT hnum = hnum_orig;
537 unsigned HOST_WIDE_INT lden = lden_orig;
538 HOST_WIDE_INT hden = hden_orig;
541 if (hden == 0 && lden == 0)
542 overflow = 1, lden = 1;
544 /* calculate quotient sign and convert operands to unsigned. */
550 /* (minimum integer) / (-1) is the only overflow case. */
551 if (neg_double (lnum, hnum, &lnum, &hnum)
552 && ((HOST_WIDE_INT) lden & hden) == -1)
558 neg_double (lden, hden, &lden, &hden);
562 if (hnum == 0 && hden == 0)
563 { /* single precision */
565 /* This unsigned division rounds toward zero. */
571 { /* trivial case: dividend < divisor */
572 /* hden != 0 already checked. */
579 bzero ((char *) quo, sizeof quo);
581 bzero ((char *) num, sizeof num); /* to zero 9th element */
582 bzero ((char *) den, sizeof den);
584 encode (num, lnum, hnum);
585 encode (den, lden, hden);
587 /* Special code for when the divisor < BASE. */
588 if (hden == 0 && lden < (unsigned HOST_WIDE_INT) BASE)
590 /* hnum != 0 already checked. */
591 for (i = 4 - 1; i >= 0; i--)
593 work = num[i] + carry * BASE;
594 quo[i] = work / lden;
600 /* Full double precision division,
601 with thanks to Don Knuth's "Seminumerical Algorithms". */
602 int num_hi_sig, den_hi_sig;
603 unsigned HOST_WIDE_INT quo_est, scale;
605 /* Find the highest non-zero divisor digit. */
606 for (i = 4 - 1;; i--)
613 /* Insure that the first digit of the divisor is at least BASE/2.
614 This is required by the quotient digit estimation algorithm. */
616 scale = BASE / (den[den_hi_sig] + 1);
618 { /* scale divisor and dividend */
620 for (i = 0; i <= 4 - 1; i++)
622 work = (num[i] * scale) + carry;
623 num[i] = LOWPART (work);
624 carry = HIGHPART (work);
629 for (i = 0; i <= 4 - 1; i++)
631 work = (den[i] * scale) + carry;
632 den[i] = LOWPART (work);
633 carry = HIGHPART (work);
634 if (den[i] != 0) den_hi_sig = i;
641 for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--)
643 /* Guess the next quotient digit, quo_est, by dividing the first
644 two remaining dividend digits by the high order quotient digit.
645 quo_est is never low and is at most 2 high. */
646 unsigned HOST_WIDE_INT tmp;
648 num_hi_sig = i + den_hi_sig + 1;
649 work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
650 if (num[num_hi_sig] != den[den_hi_sig])
651 quo_est = work / den[den_hi_sig];
655 /* Refine quo_est so it's usually correct, and at most one high. */
656 tmp = work - quo_est * den[den_hi_sig];
658 && (den[den_hi_sig - 1] * quo_est
659 > (tmp * BASE + num[num_hi_sig - 2])))
662 /* Try QUO_EST as the quotient digit, by multiplying the
663 divisor by QUO_EST and subtracting from the remaining dividend.
664 Keep in mind that QUO_EST is the I - 1st digit. */
667 for (j = 0; j <= den_hi_sig; j++)
669 work = quo_est * den[j] + carry;
670 carry = HIGHPART (work);
671 work = num[i + j] - LOWPART (work);
672 num[i + j] = LOWPART (work);
673 carry += HIGHPART (work) != 0;
676 /* If quo_est was high by one, then num[i] went negative and
677 we need to correct things. */
678 if (num[num_hi_sig] < carry)
681 carry = 0; /* add divisor back in */
682 for (j = 0; j <= den_hi_sig; j++)
684 work = num[i + j] + den[j] + carry;
685 carry = HIGHPART (work);
686 num[i + j] = LOWPART (work);
689 num [num_hi_sig] += carry;
692 /* Store the quotient digit. */
697 decode (quo, lquo, hquo);
700 /* if result is negative, make it so. */
702 neg_double (*lquo, *hquo, lquo, hquo);
704 /* compute trial remainder: rem = num - (quo * den) */
705 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
706 neg_double (*lrem, *hrem, lrem, hrem);
707 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
712 case TRUNC_MOD_EXPR: /* round toward zero */
713 case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
717 case FLOOR_MOD_EXPR: /* round toward negative infinity */
718 if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
721 add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
729 case CEIL_MOD_EXPR: /* round toward positive infinity */
730 if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
732 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
740 case ROUND_MOD_EXPR: /* round to closest integer */
742 unsigned HOST_WIDE_INT labs_rem = *lrem;
743 HOST_WIDE_INT habs_rem = *hrem;
744 unsigned HOST_WIDE_INT labs_den = lden, ltwice;
745 HOST_WIDE_INT habs_den = hden, htwice;
747 /* Get absolute values */
749 neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
751 neg_double (lden, hden, &labs_den, &habs_den);
753 /* If (2 * abs (lrem) >= abs (lden)) */
754 mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
755 labs_rem, habs_rem, <wice, &htwice);
757 if (((unsigned HOST_WIDE_INT) habs_den
758 < (unsigned HOST_WIDE_INT) htwice)
759 || (((unsigned HOST_WIDE_INT) habs_den
760 == (unsigned HOST_WIDE_INT) htwice)
761 && (labs_den < ltwice)))
765 add_double (*lquo, *hquo,
766 (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
769 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
781 /* compute true remainder: rem = num - (quo * den) */
782 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
783 neg_double (*lrem, *hrem, lrem, hrem);
784 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
788 #ifndef REAL_ARITHMETIC
789 /* Effectively truncate a real value to represent the nearest possible value
790 in a narrower mode. The result is actually represented in the same data
791 type as the argument, but its value is usually different.
793 A trap may occur during the FP operations and it is the responsibility
794 of the calling function to have a handler established. */
797 real_value_truncate (mode, arg)
798 enum machine_mode mode;
801 return REAL_VALUE_TRUNCATE (mode, arg);
804 #if TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
806 /* Check for infinity in an IEEE double precision number. */
812 /* The IEEE 64-bit double format. */
817 unsigned exponent : 11;
818 unsigned mantissa1 : 20;
823 unsigned mantissa1 : 20;
824 unsigned exponent : 11;
830 if (u.big_endian.sign == 1)
833 return (u.big_endian.exponent == 2047
834 && u.big_endian.mantissa1 == 0
835 && u.big_endian.mantissa2 == 0);
840 return (u.little_endian.exponent == 2047
841 && u.little_endian.mantissa1 == 0
842 && u.little_endian.mantissa2 == 0);
846 /* Check whether an IEEE double precision number is a NaN. */
852 /* The IEEE 64-bit double format. */
857 unsigned exponent : 11;
858 unsigned mantissa1 : 20;
863 unsigned mantissa1 : 20;
864 unsigned exponent : 11;
870 if (u.big_endian.sign == 1)
873 return (u.big_endian.exponent == 2047
874 && (u.big_endian.mantissa1 != 0
875 || u.big_endian.mantissa2 != 0));
880 return (u.little_endian.exponent == 2047
881 && (u.little_endian.mantissa1 != 0
882 || u.little_endian.mantissa2 != 0));
886 /* Check for a negative IEEE double precision number. */
892 /* The IEEE 64-bit double format. */
897 unsigned exponent : 11;
898 unsigned mantissa1 : 20;
903 unsigned mantissa1 : 20;
904 unsigned exponent : 11;
910 if (u.big_endian.sign == 1)
913 return u.big_endian.sign;
918 return u.little_endian.sign;
921 #else /* Target not IEEE */
923 /* Let's assume other float formats don't have infinity.
924 (This can be overridden by redefining REAL_VALUE_ISINF.) */
928 REAL_VALUE_TYPE x ATTRIBUTE_UNUSED;
933 /* Let's assume other float formats don't have NaNs.
934 (This can be overridden by redefining REAL_VALUE_ISNAN.) */
938 REAL_VALUE_TYPE x ATTRIBUTE_UNUSED;
943 /* Let's assume other float formats don't have minus zero.
944 (This can be overridden by redefining REAL_VALUE_NEGATIVE.) */
952 #endif /* Target not IEEE */
954 /* Try to change R into its exact multiplicative inverse in machine mode
955 MODE. Return nonzero function value if successful. */
958 exact_real_inverse (mode, r)
959 enum machine_mode mode;
968 #ifdef CHECK_FLOAT_VALUE
972 /* Usually disable if bounds checks are not reliable. */
973 if ((HOST_FLOAT_FORMAT != TARGET_FLOAT_FORMAT) && !flag_pretend_float)
976 /* Set array index to the less significant bits in the unions, depending
977 on the endian-ness of the host doubles.
978 Disable if insufficient information on the data structure. */
979 #if HOST_FLOAT_FORMAT == UNKNOWN_FLOAT_FORMAT
982 #if HOST_FLOAT_FORMAT == VAX_FLOAT_FORMAT
985 #if HOST_FLOAT_FORMAT == IBM_FLOAT_FORMAT
988 #define K (2 * HOST_FLOAT_WORDS_BIG_ENDIAN)
993 if (setjmp (float_error))
995 /* Don't do the optimization if there was an arithmetic error. */
997 set_float_handler (NULL_PTR);
1000 set_float_handler (float_error);
1002 /* Domain check the argument. */
1007 #ifdef REAL_INFINITY
1008 if (REAL_VALUE_ISINF (x.d) || REAL_VALUE_ISNAN (x.d))
1012 /* Compute the reciprocal and check for numerical exactness.
1013 It is unnecessary to check all the significand bits to determine
1014 whether X is a power of 2. If X is not, then it is impossible for
1015 the bottom half significand of both X and 1/X to be all zero bits.
1016 Hence we ignore the data structure of the top half and examine only
1017 the low order bits of the two significands. */
1019 if (x.i[K] != 0 || x.i[K + 1] != 0 || t.i[K] != 0 || t.i[K + 1] != 0)
1022 /* Truncate to the required mode and range-check the result. */
1023 y.d = REAL_VALUE_TRUNCATE (mode, t.d);
1024 #ifdef CHECK_FLOAT_VALUE
1026 if (CHECK_FLOAT_VALUE (mode, y.d, i))
1030 /* Fail if truncation changed the value. */
1031 if (y.d != t.d || y.d == 0.0)
1034 #ifdef REAL_INFINITY
1035 if (REAL_VALUE_ISINF (y.d) || REAL_VALUE_ISNAN (y.d))
1039 /* Output the reciprocal and return success flag. */
1040 set_float_handler (NULL_PTR);
1045 /* Convert C9X hexadecimal floating point string constant S. Return
1046 real value type in mode MODE. This function uses the host computer's
1047 floating point arithmetic when there is no REAL_ARITHMETIC. */
1050 real_hex_to_f (s, mode)
1052 enum machine_mode mode;
1056 unsigned HOST_WIDE_INT low, high;
1057 int shcount, nrmcount, k;
1058 int sign, expsign, isfloat;
1059 int lost = 0;/* Nonzero low order bits shifted out and discarded. */
1060 int frexpon = 0; /* Bits after the decimal point. */
1061 int expon = 0; /* Value of exponent. */
1062 int decpt = 0; /* How many decimal points. */
1063 int gotp = 0; /* How many P's. */
1070 while (*p == ' ' || *p == '\t')
1073 /* Sign, if any, comes first. */
1081 /* The string is supposed to start with 0x or 0X . */
1085 if (*p == 'x' || *p == 'X')
1099 while ((c = *p) != '\0')
1101 if ((c >= '0' && c <= '9') || (c >= 'A' && c <= 'F')
1102 || (c >= 'a' && c <= 'f'))
1105 if (k >= 'a' && k <= 'f')
1112 if ((high & 0xf0000000) == 0)
1114 high = (high << 4) + ((low >> 28) & 15);
1115 low = (low << 4) + k;
1122 /* Record nonzero lost bits. */
1135 else if (c == 'p' || c == 'P')
1139 /* Sign of exponent. */
1146 /* Value of exponent.
1147 The exponent field is a decimal integer. */
1148 while (ISDIGIT (*p))
1150 k = (*p++ & CHARMASK) - '0';
1151 expon = 10 * expon + k;
1155 /* F suffix is ambiguous in the significand part
1156 so it must appear after the decimal exponent field. */
1157 if (*p == 'f' || *p == 'F')
1165 else if (c == 'l' || c == 'L')
1174 /* Abort if last character read was not legitimate. */
1176 if ((c != '\0' && c != ' ' && c != '\n' && c != '\r') || (decpt > 1))
1179 /* There must be either one decimal point or one p. */
1180 if (decpt == 0 && gotp == 0)
1184 if (high == 0 && low == 0)
1196 /* Leave a high guard bit for carry-out. */
1197 if ((high & 0x80000000) != 0)
1200 low = (low >> 1) | (high << 31);
1205 if ((high & 0xffff8000) == 0)
1207 high = (high << 16) + ((low >> 16) & 0xffff);
1212 while ((high & 0xc0000000) == 0)
1214 high = (high << 1) + ((low >> 31) & 1);
1219 if (isfloat || GET_MODE_SIZE (mode) == UNITS_PER_WORD)
1221 /* Keep 24 bits precision, bits 0x7fffff80.
1222 Rounding bit is 0x40. */
1223 lost = lost | low | (high & 0x3f);
1227 if ((high & 0x80) || lost)
1234 /* We need real.c to do long double formats, so here default
1235 to double precision. */
1236 #if HOST_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
1238 Keep 53 bits precision, bits 0x7fffffff fffffc00.
1239 Rounding bit is low word 0x200. */
1240 lost = lost | (low & 0x1ff);
1243 if ((low & 0x400) || lost)
1245 low = (low + 0x200) & 0xfffffc00;
1252 /* Assume it's a VAX with 56-bit significand,
1253 bits 0x7fffffff ffffff80. */
1254 lost = lost | (low & 0x7f);
1257 if ((low & 0x80) || lost)
1259 low = (low + 0x40) & 0xffffff80;
1269 ip = REAL_VALUE_LDEXP (ip, 32) + (double) low;
1270 /* Apply shifts and exponent value as power of 2. */
1271 ip = REAL_VALUE_LDEXP (ip, expon - (nrmcount + frexpon));
1278 #endif /* no REAL_ARITHMETIC */
1280 /* Given T, an expression, return the negation of T. Allow for T to be
1281 null, in which case return null. */
1293 type = TREE_TYPE (t);
1294 STRIP_SIGN_NOPS (t);
1296 switch (TREE_CODE (t))
1300 if (! TREE_UNSIGNED (type)
1301 && 0 != (tem = fold (build1 (NEGATE_EXPR, type, t)))
1302 && ! TREE_OVERFLOW (tem))
1307 return convert (type, TREE_OPERAND (t, 0));
1310 /* - (A - B) -> B - A */
1311 if (! FLOAT_TYPE_P (type) || flag_fast_math)
1312 return convert (type,
1313 fold (build (MINUS_EXPR, TREE_TYPE (t),
1314 TREE_OPERAND (t, 1),
1315 TREE_OPERAND (t, 0))));
1322 return convert (type, build1 (NEGATE_EXPR, TREE_TYPE (t), t));
1325 /* Split a tree IN into a constant, literal and variable parts that could be
1326 combined with CODE to make IN. "constant" means an expression with
1327 TREE_CONSTANT but that isn't an actual constant. CODE must be a
1328 commutative arithmetic operation. Store the constant part into *CONP,
1329 the literal in &LITP and return the variable part. If a part isn't
1330 present, set it to null. If the tree does not decompose in this way,
1331 return the entire tree as the variable part and the other parts as null.
1333 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
1334 case, we negate an operand that was subtracted. If NEGATE_P is true, we
1335 are negating all of IN.
1337 If IN is itself a literal or constant, return it as appropriate.
1339 Note that we do not guarantee that any of the three values will be the
1340 same type as IN, but they will have the same signedness and mode. */
1343 split_tree (in, code, conp, litp, negate_p)
1345 enum tree_code code;
1354 /* Strip any conversions that don't change the machine mode or signedness. */
1355 STRIP_SIGN_NOPS (in);
1357 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST)
1359 else if (TREE_CONSTANT (in))
1362 else if (TREE_CODE (in) == code
1363 || (! FLOAT_TYPE_P (TREE_TYPE (in))
1364 /* We can associate addition and subtraction together (even
1365 though the C standard doesn't say so) for integers because
1366 the value is not affected. For reals, the value might be
1367 affected, so we can't. */
1368 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
1369 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
1371 tree op0 = TREE_OPERAND (in, 0);
1372 tree op1 = TREE_OPERAND (in, 1);
1373 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
1374 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
1376 /* First see if either of the operands is a literal, then a constant. */
1377 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
1378 *litp = op0, op0 = 0;
1379 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST)
1380 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
1382 if (op0 != 0 && TREE_CONSTANT (op0))
1383 *conp = op0, op0 = 0;
1384 else if (op1 != 0 && TREE_CONSTANT (op1))
1385 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
1387 /* If we haven't dealt with either operand, this is not a case we can
1388 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1389 if (op0 != 0 && op1 != 0)
1394 var = op1, neg_var_p = neg1_p;
1396 /* Now do any needed negations. */
1397 if (neg_litp_p) *litp = negate_expr (*litp);
1398 if (neg_conp_p) *conp = negate_expr (*conp);
1399 if (neg_var_p) var = negate_expr (var);
1406 var = negate_expr (var);
1407 *conp = negate_expr (*conp);
1408 *litp = negate_expr (*litp);
1414 /* Re-associate trees split by the above function. T1 and T2 are either
1415 expressions to associate or null. Return the new expression, if any. If
1416 we build an operation, do it in TYPE and with CODE, except if CODE is a
1417 MINUS_EXPR, in which case we use PLUS_EXPR since split_tree will already
1418 have taken care of the negations. */
1421 associate_trees (t1, t2, code, type)
1423 enum tree_code code;
1431 if (code == MINUS_EXPR)
1434 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1435 try to fold this since we will have infinite recursion. But do
1436 deal with any NEGATE_EXPRs. */
1437 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
1438 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1440 if (TREE_CODE (t1) == NEGATE_EXPR)
1441 return build (MINUS_EXPR, type, convert (type, t2),
1442 convert (type, TREE_OPERAND (t1, 0)));
1443 else if (TREE_CODE (t2) == NEGATE_EXPR)
1444 return build (MINUS_EXPR, type, convert (type, t1),
1445 convert (type, TREE_OPERAND (t2, 0)));
1447 return build (code, type, convert (type, t1), convert (type, t2));
1450 return fold (build (code, type, convert (type, t1), convert (type, t2)));
1453 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1454 to produce a new constant.
1456 If NOTRUNC is nonzero, do not truncate the result to fit the data type.
1457 If FORSIZE is nonzero, compute overflow for unsigned types. */
1460 int_const_binop (code, arg1, arg2, notrunc, forsize)
1461 enum tree_code code;
1462 register tree arg1, arg2;
1463 int notrunc, forsize;
1465 unsigned HOST_WIDE_INT int1l, int2l;
1466 HOST_WIDE_INT int1h, int2h;
1467 unsigned HOST_WIDE_INT low;
1469 unsigned HOST_WIDE_INT garbagel;
1470 HOST_WIDE_INT garbageh;
1472 int uns = TREE_UNSIGNED (TREE_TYPE (arg1));
1474 int no_overflow = 0;
1476 int1l = TREE_INT_CST_LOW (arg1);
1477 int1h = TREE_INT_CST_HIGH (arg1);
1478 int2l = TREE_INT_CST_LOW (arg2);
1479 int2h = TREE_INT_CST_HIGH (arg2);
1484 low = int1l | int2l, hi = int1h | int2h;
1488 low = int1l ^ int2l, hi = int1h ^ int2h;
1492 low = int1l & int2l, hi = int1h & int2h;
1495 case BIT_ANDTC_EXPR:
1496 low = int1l & ~int2l, hi = int1h & ~int2h;
1502 /* It's unclear from the C standard whether shifts can overflow.
1503 The following code ignores overflow; perhaps a C standard
1504 interpretation ruling is needed. */
1505 lshift_double (int1l, int1h, int2l, TYPE_PRECISION (TREE_TYPE (arg1)),
1513 lrotate_double (int1l, int1h, int2l, TYPE_PRECISION (TREE_TYPE (arg1)),
1518 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1522 neg_double (int2l, int2h, &low, &hi);
1523 add_double (int1l, int1h, low, hi, &low, &hi);
1524 overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
1528 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1531 case TRUNC_DIV_EXPR:
1532 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1533 case EXACT_DIV_EXPR:
1534 /* This is a shortcut for a common special case. */
1535 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1536 && ! TREE_CONSTANT_OVERFLOW (arg1)
1537 && ! TREE_CONSTANT_OVERFLOW (arg2)
1538 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1540 if (code == CEIL_DIV_EXPR)
1543 low = int1l / int2l, hi = 0;
1547 /* ... fall through ... */
1549 case ROUND_DIV_EXPR:
1550 if (int2h == 0 && int2l == 1)
1552 low = int1l, hi = int1h;
1555 if (int1l == int2l && int1h == int2h
1556 && ! (int1l == 0 && int1h == 0))
1561 overflow = div_and_round_double (code, uns,
1562 int1l, int1h, int2l, int2h,
1563 &low, &hi, &garbagel, &garbageh);
1566 case TRUNC_MOD_EXPR:
1567 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1568 /* This is a shortcut for a common special case. */
1569 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1570 && ! TREE_CONSTANT_OVERFLOW (arg1)
1571 && ! TREE_CONSTANT_OVERFLOW (arg2)
1572 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1574 if (code == CEIL_MOD_EXPR)
1576 low = int1l % int2l, hi = 0;
1580 /* ... fall through ... */
1582 case ROUND_MOD_EXPR:
1583 overflow = div_and_round_double (code, uns,
1584 int1l, int1h, int2l, int2h,
1585 &garbagel, &garbageh, &low, &hi);
1591 low = (((unsigned HOST_WIDE_INT) int1h
1592 < (unsigned HOST_WIDE_INT) int2h)
1593 || (((unsigned HOST_WIDE_INT) int1h
1594 == (unsigned HOST_WIDE_INT) int2h)
1597 low = (int1h < int2h
1598 || (int1h == int2h && int1l < int2l));
1600 if (low == (code == MIN_EXPR))
1601 low = int1l, hi = int1h;
1603 low = int2l, hi = int2h;
1610 if (forsize && hi == 0 && low < 10000
1611 && overflow == 0 && ! TREE_OVERFLOW (arg1) && ! TREE_OVERFLOW (arg2))
1612 return size_int_type_wide (low, TREE_TYPE (arg1));
1615 t = build_int_2 (low, hi);
1616 TREE_TYPE (t) = TREE_TYPE (arg1);
1620 = ((notrunc ? (!uns || forsize) && overflow
1621 : force_fit_type (t, (!uns || forsize) && overflow) && ! no_overflow)
1622 | TREE_OVERFLOW (arg1)
1623 | TREE_OVERFLOW (arg2));
1625 /* If we're doing a size calculation, unsigned arithmetic does overflow.
1626 So check if force_fit_type truncated the value. */
1628 && ! TREE_OVERFLOW (t)
1629 && (TREE_INT_CST_HIGH (t) != hi
1630 || TREE_INT_CST_LOW (t) != low))
1631 TREE_OVERFLOW (t) = 1;
1633 TREE_CONSTANT_OVERFLOW (t) = (TREE_OVERFLOW (t)
1634 | TREE_CONSTANT_OVERFLOW (arg1)
1635 | TREE_CONSTANT_OVERFLOW (arg2));
1639 /* Define input and output argument for const_binop_1. */
1642 enum tree_code code; /* Input: tree code for operation. */
1643 tree type; /* Input: tree type for operation. */
1644 REAL_VALUE_TYPE d1, d2; /* Input: floating point operands. */
1645 tree t; /* Output: constant for result. */
1648 /* Do the real arithmetic for const_binop while protected by a
1649 float overflow handler. */
1652 const_binop_1 (data)
1655 struct cb_args *args = (struct cb_args *) data;
1656 REAL_VALUE_TYPE value;
1658 #ifdef REAL_ARITHMETIC
1659 REAL_ARITHMETIC (value, args->code, args->d1, args->d2);
1664 value = args->d1 + args->d2;
1668 value = args->d1 - args->d2;
1672 value = args->d1 * args->d2;
1676 #ifndef REAL_INFINITY
1681 value = args->d1 / args->d2;
1685 value = MIN (args->d1, args->d2);
1689 value = MAX (args->d1, args->d2);
1695 #endif /* no REAL_ARITHMETIC */
1698 = build_real (args->type,
1699 real_value_truncate (TYPE_MODE (args->type), value));
1702 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1703 constant. We assume ARG1 and ARG2 have the same data type, or at least
1704 are the same kind of constant and the same machine mode.
1706 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1709 const_binop (code, arg1, arg2, notrunc)
1710 enum tree_code code;
1711 register tree arg1, arg2;
1717 if (TREE_CODE (arg1) == INTEGER_CST)
1718 return int_const_binop (code, arg1, arg2, notrunc, 0);
1720 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1721 if (TREE_CODE (arg1) == REAL_CST)
1727 struct cb_args args;
1729 d1 = TREE_REAL_CST (arg1);
1730 d2 = TREE_REAL_CST (arg2);
1732 /* If either operand is a NaN, just return it. Otherwise, set up
1733 for floating-point trap; we return an overflow. */
1734 if (REAL_VALUE_ISNAN (d1))
1736 else if (REAL_VALUE_ISNAN (d2))
1739 /* Setup input for const_binop_1() */
1740 args.type = TREE_TYPE (arg1);
1745 if (do_float_handler (const_binop_1, (PTR) &args))
1746 /* Receive output from const_binop_1. */
1750 /* We got an exception from const_binop_1. */
1751 t = copy_node (arg1);
1756 = (force_fit_type (t, overflow)
1757 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
1758 TREE_CONSTANT_OVERFLOW (t)
1760 | TREE_CONSTANT_OVERFLOW (arg1)
1761 | TREE_CONSTANT_OVERFLOW (arg2);
1764 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
1765 if (TREE_CODE (arg1) == COMPLEX_CST)
1767 register tree type = TREE_TYPE (arg1);
1768 register tree r1 = TREE_REALPART (arg1);
1769 register tree i1 = TREE_IMAGPART (arg1);
1770 register tree r2 = TREE_REALPART (arg2);
1771 register tree i2 = TREE_IMAGPART (arg2);
1777 t = build_complex (type,
1778 const_binop (PLUS_EXPR, r1, r2, notrunc),
1779 const_binop (PLUS_EXPR, i1, i2, notrunc));
1783 t = build_complex (type,
1784 const_binop (MINUS_EXPR, r1, r2, notrunc),
1785 const_binop (MINUS_EXPR, i1, i2, notrunc));
1789 t = build_complex (type,
1790 const_binop (MINUS_EXPR,
1791 const_binop (MULT_EXPR,
1793 const_binop (MULT_EXPR,
1796 const_binop (PLUS_EXPR,
1797 const_binop (MULT_EXPR,
1799 const_binop (MULT_EXPR,
1806 register tree magsquared
1807 = const_binop (PLUS_EXPR,
1808 const_binop (MULT_EXPR, r2, r2, notrunc),
1809 const_binop (MULT_EXPR, i2, i2, notrunc),
1812 t = build_complex (type,
1814 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1815 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1816 const_binop (PLUS_EXPR,
1817 const_binop (MULT_EXPR, r1, r2,
1819 const_binop (MULT_EXPR, i1, i2,
1822 magsquared, notrunc),
1824 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1825 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1826 const_binop (MINUS_EXPR,
1827 const_binop (MULT_EXPR, i1, r2,
1829 const_binop (MULT_EXPR, r1, i2,
1832 magsquared, notrunc));
1844 /* Return an INTEGER_CST with value whose low-order HOST_BITS_PER_WIDE_INT
1845 bits are given by NUMBER and of the sizetype represented by KIND. */
1848 size_int_wide (number, kind)
1849 HOST_WIDE_INT number;
1850 enum size_type_kind kind;
1852 return size_int_type_wide (number, sizetype_tab[(int) kind]);
1855 /* Likewise, but the desired type is specified explicitly. */
1858 size_int_type_wide (number, type)
1859 HOST_WIDE_INT number;
1862 /* Type-size nodes already made for small sizes. */
1863 static tree size_table[2048 + 1];
1864 static int init_p = 0;
1869 ggc_add_tree_root ((tree *) size_table,
1870 sizeof size_table / sizeof (tree));
1874 /* If this is a positive number that fits in the table we use to hold
1875 cached entries, see if it is already in the table and put it there
1877 if (number >= 0 && number < (int) ARRAY_SIZE (size_table))
1879 if (size_table[number] != 0)
1880 for (t = size_table[number]; t != 0; t = TREE_CHAIN (t))
1881 if (TREE_TYPE (t) == type)
1884 t = build_int_2 (number, 0);
1885 TREE_TYPE (t) = type;
1886 TREE_CHAIN (t) = size_table[number];
1887 size_table[number] = t;
1892 t = build_int_2 (number, number < 0 ? -1 : 0);
1893 TREE_TYPE (t) = type;
1894 TREE_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (t) = force_fit_type (t, 0);
1898 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1899 is a tree code. The type of the result is taken from the operands.
1900 Both must be the same type integer type and it must be a size type.
1901 If the operands are constant, so is the result. */
1904 size_binop (code, arg0, arg1)
1905 enum tree_code code;
1908 tree type = TREE_TYPE (arg0);
1910 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1911 || type != TREE_TYPE (arg1))
1914 /* Handle the special case of two integer constants faster. */
1915 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1917 /* And some specific cases even faster than that. */
1918 if (code == PLUS_EXPR && integer_zerop (arg0))
1920 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1921 && integer_zerop (arg1))
1923 else if (code == MULT_EXPR && integer_onep (arg0))
1926 /* Handle general case of two integer constants. */
1927 return int_const_binop (code, arg0, arg1, 0, 1);
1930 if (arg0 == error_mark_node || arg1 == error_mark_node)
1931 return error_mark_node;
1933 return fold (build (code, type, arg0, arg1));
1936 /* Given two values, either both of sizetype or both of bitsizetype,
1937 compute the difference between the two values. Return the value
1938 in signed type corresponding to the type of the operands. */
1941 size_diffop (arg0, arg1)
1944 tree type = TREE_TYPE (arg0);
1947 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1948 || type != TREE_TYPE (arg1))
1951 /* If the type is already signed, just do the simple thing. */
1952 if (! TREE_UNSIGNED (type))
1953 return size_binop (MINUS_EXPR, arg0, arg1);
1955 ctype = (type == bitsizetype || type == ubitsizetype
1956 ? sbitsizetype : ssizetype);
1958 /* If either operand is not a constant, do the conversions to the signed
1959 type and subtract. The hardware will do the right thing with any
1960 overflow in the subtraction. */
1961 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
1962 return size_binop (MINUS_EXPR, convert (ctype, arg0),
1963 convert (ctype, arg1));
1965 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
1966 Otherwise, subtract the other way, convert to CTYPE (we know that can't
1967 overflow) and negate (which can't either). Special-case a result
1968 of zero while we're here. */
1969 if (tree_int_cst_equal (arg0, arg1))
1970 return convert (ctype, integer_zero_node);
1971 else if (tree_int_cst_lt (arg1, arg0))
1972 return convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
1974 return size_binop (MINUS_EXPR, convert (ctype, integer_zero_node),
1975 convert (ctype, size_binop (MINUS_EXPR, arg1, arg0)));
1978 /* This structure is used to communicate arguments to fold_convert_1. */
1981 tree arg1; /* Input: value to convert. */
1982 tree type; /* Input: type to convert value to. */
1983 tree t; /* Ouput: result of conversion. */
1986 /* Function to convert floating-point constants, protected by floating
1987 point exception handler. */
1990 fold_convert_1 (data)
1993 struct fc_args *args = (struct fc_args *) data;
1995 args->t = build_real (args->type,
1996 real_value_truncate (TYPE_MODE (args->type),
1997 TREE_REAL_CST (args->arg1)));
2000 /* Given T, a tree representing type conversion of ARG1, a constant,
2001 return a constant tree representing the result of conversion. */
2004 fold_convert (t, arg1)
2008 register tree type = TREE_TYPE (t);
2011 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
2013 if (TREE_CODE (arg1) == INTEGER_CST)
2015 /* If we would build a constant wider than GCC supports,
2016 leave the conversion unfolded. */
2017 if (TYPE_PRECISION (type) > 2 * HOST_BITS_PER_WIDE_INT)
2020 /* If we are trying to make a sizetype for a small integer, use
2021 size_int to pick up cached types to reduce duplicate nodes. */
2022 if (TREE_CODE (type) == INTEGER_CST && TYPE_IS_SIZETYPE (type)
2023 && compare_tree_int (arg1, 10000) < 0)
2024 return size_int_type_wide (TREE_INT_CST_LOW (arg1), type);
2026 /* Given an integer constant, make new constant with new type,
2027 appropriately sign-extended or truncated. */
2028 t = build_int_2 (TREE_INT_CST_LOW (arg1),
2029 TREE_INT_CST_HIGH (arg1));
2030 TREE_TYPE (t) = type;
2031 /* Indicate an overflow if (1) ARG1 already overflowed,
2032 or (2) force_fit_type indicates an overflow.
2033 Tell force_fit_type that an overflow has already occurred
2034 if ARG1 is a too-large unsigned value and T is signed.
2035 But don't indicate an overflow if converting a pointer. */
2037 = ((force_fit_type (t,
2038 (TREE_INT_CST_HIGH (arg1) < 0
2039 && (TREE_UNSIGNED (type)
2040 < TREE_UNSIGNED (TREE_TYPE (arg1)))))
2041 && ! POINTER_TYPE_P (TREE_TYPE (arg1)))
2042 || TREE_OVERFLOW (arg1));
2043 TREE_CONSTANT_OVERFLOW (t)
2044 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
2046 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
2047 else if (TREE_CODE (arg1) == REAL_CST)
2049 /* Don't initialize these, use assignments.
2050 Initialized local aggregates don't work on old compilers. */
2054 tree type1 = TREE_TYPE (arg1);
2057 x = TREE_REAL_CST (arg1);
2058 l = real_value_from_int_cst (type1, TYPE_MIN_VALUE (type));
2060 no_upper_bound = (TYPE_MAX_VALUE (type) == NULL);
2061 if (!no_upper_bound)
2062 u = real_value_from_int_cst (type1, TYPE_MAX_VALUE (type));
2064 /* See if X will be in range after truncation towards 0.
2065 To compensate for truncation, move the bounds away from 0,
2066 but reject if X exactly equals the adjusted bounds. */
2067 #ifdef REAL_ARITHMETIC
2068 REAL_ARITHMETIC (l, MINUS_EXPR, l, dconst1);
2069 if (!no_upper_bound)
2070 REAL_ARITHMETIC (u, PLUS_EXPR, u, dconst1);
2073 if (!no_upper_bound)
2076 /* If X is a NaN, use zero instead and show we have an overflow.
2077 Otherwise, range check. */
2078 if (REAL_VALUE_ISNAN (x))
2079 overflow = 1, x = dconst0;
2080 else if (! (REAL_VALUES_LESS (l, x)
2082 && REAL_VALUES_LESS (x, u)))
2085 #ifndef REAL_ARITHMETIC
2087 HOST_WIDE_INT low, high;
2088 HOST_WIDE_INT half_word
2089 = (HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2);
2094 high = (HOST_WIDE_INT) (x / half_word / half_word);
2095 x -= (REAL_VALUE_TYPE) high * half_word * half_word;
2096 if (x >= (REAL_VALUE_TYPE) half_word * half_word / 2)
2098 low = x - (REAL_VALUE_TYPE) half_word * half_word / 2;
2099 low |= (HOST_WIDE_INT) -1 << (HOST_BITS_PER_WIDE_INT - 1);
2102 low = (HOST_WIDE_INT) x;
2103 if (TREE_REAL_CST (arg1) < 0)
2104 neg_double (low, high, &low, &high);
2105 t = build_int_2 (low, high);
2109 HOST_WIDE_INT low, high;
2110 REAL_VALUE_TO_INT (&low, &high, x);
2111 t = build_int_2 (low, high);
2114 TREE_TYPE (t) = type;
2116 = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
2117 TREE_CONSTANT_OVERFLOW (t)
2118 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
2120 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
2121 TREE_TYPE (t) = type;
2123 else if (TREE_CODE (type) == REAL_TYPE)
2125 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
2126 if (TREE_CODE (arg1) == INTEGER_CST)
2127 return build_real_from_int_cst (type, arg1);
2128 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
2129 if (TREE_CODE (arg1) == REAL_CST)
2131 struct fc_args args;
2133 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
2136 TREE_TYPE (arg1) = type;
2140 /* Setup input for fold_convert_1() */
2144 if (do_float_handler (fold_convert_1, (PTR) &args))
2146 /* Receive output from fold_convert_1() */
2151 /* We got an exception from fold_convert_1() */
2153 t = copy_node (arg1);
2157 = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
2158 TREE_CONSTANT_OVERFLOW (t)
2159 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
2163 TREE_CONSTANT (t) = 1;
2167 /* Return an expr equal to X but certainly not valid as an lvalue. */
2175 /* These things are certainly not lvalues. */
2176 if (TREE_CODE (x) == NON_LVALUE_EXPR
2177 || TREE_CODE (x) == INTEGER_CST
2178 || TREE_CODE (x) == REAL_CST
2179 || TREE_CODE (x) == STRING_CST
2180 || TREE_CODE (x) == ADDR_EXPR)
2183 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
2184 TREE_CONSTANT (result) = TREE_CONSTANT (x);
2188 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
2189 Zero means allow extended lvalues. */
2191 int pedantic_lvalues;
2193 /* When pedantic, return an expr equal to X but certainly not valid as a
2194 pedantic lvalue. Otherwise, return X. */
2197 pedantic_non_lvalue (x)
2200 if (pedantic_lvalues)
2201 return non_lvalue (x);
2206 /* Given a tree comparison code, return the code that is the logical inverse
2207 of the given code. It is not safe to do this for floating-point
2208 comparisons, except for NE_EXPR and EQ_EXPR. */
2210 static enum tree_code
2211 invert_tree_comparison (code)
2212 enum tree_code code;
2233 /* Similar, but return the comparison that results if the operands are
2234 swapped. This is safe for floating-point. */
2236 static enum tree_code
2237 swap_tree_comparison (code)
2238 enum tree_code code;
2258 /* Return nonzero if CODE is a tree code that represents a truth value. */
2261 truth_value_p (code)
2262 enum tree_code code;
2264 return (TREE_CODE_CLASS (code) == '<'
2265 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2266 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2267 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
2270 /* Return nonzero if two operands are necessarily equal.
2271 If ONLY_CONST is non-zero, only return non-zero for constants.
2272 This function tests whether the operands are indistinguishable;
2273 it does not test whether they are equal using C's == operation.
2274 The distinction is important for IEEE floating point, because
2275 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2276 (2) two NaNs may be indistinguishable, but NaN!=NaN. */
2279 operand_equal_p (arg0, arg1, only_const)
2283 /* If both types don't have the same signedness, then we can't consider
2284 them equal. We must check this before the STRIP_NOPS calls
2285 because they may change the signedness of the arguments. */
2286 if (TREE_UNSIGNED (TREE_TYPE (arg0)) != TREE_UNSIGNED (TREE_TYPE (arg1)))
2292 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2293 /* This is needed for conversions and for COMPONENT_REF.
2294 Might as well play it safe and always test this. */
2295 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
2296 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
2297 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
2300 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
2301 We don't care about side effects in that case because the SAVE_EXPR
2302 takes care of that for us. In all other cases, two expressions are
2303 equal if they have no side effects. If we have two identical
2304 expressions with side effects that should be treated the same due
2305 to the only side effects being identical SAVE_EXPR's, that will
2306 be detected in the recursive calls below. */
2307 if (arg0 == arg1 && ! only_const
2308 && (TREE_CODE (arg0) == SAVE_EXPR
2309 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
2312 /* Next handle constant cases, those for which we can return 1 even
2313 if ONLY_CONST is set. */
2314 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
2315 switch (TREE_CODE (arg0))
2318 return (! TREE_CONSTANT_OVERFLOW (arg0)
2319 && ! TREE_CONSTANT_OVERFLOW (arg1)
2320 && tree_int_cst_equal (arg0, arg1));
2323 return (! TREE_CONSTANT_OVERFLOW (arg0)
2324 && ! TREE_CONSTANT_OVERFLOW (arg1)
2325 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
2326 TREE_REAL_CST (arg1)));
2329 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
2331 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
2335 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
2336 && ! memcmp (TREE_STRING_POINTER (arg0),
2337 TREE_STRING_POINTER (arg1),
2338 TREE_STRING_LENGTH (arg0)));
2341 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
2350 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
2353 /* Two conversions are equal only if signedness and modes match. */
2354 if ((TREE_CODE (arg0) == NOP_EXPR || TREE_CODE (arg0) == CONVERT_EXPR)
2355 && (TREE_UNSIGNED (TREE_TYPE (arg0))
2356 != TREE_UNSIGNED (TREE_TYPE (arg1))))
2359 return operand_equal_p (TREE_OPERAND (arg0, 0),
2360 TREE_OPERAND (arg1, 0), 0);
2364 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0)
2365 && operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1),
2369 /* For commutative ops, allow the other order. */
2370 return ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MULT_EXPR
2371 || TREE_CODE (arg0) == MIN_EXPR || TREE_CODE (arg0) == MAX_EXPR
2372 || TREE_CODE (arg0) == BIT_IOR_EXPR
2373 || TREE_CODE (arg0) == BIT_XOR_EXPR
2374 || TREE_CODE (arg0) == BIT_AND_EXPR
2375 || TREE_CODE (arg0) == NE_EXPR || TREE_CODE (arg0) == EQ_EXPR)
2376 && operand_equal_p (TREE_OPERAND (arg0, 0),
2377 TREE_OPERAND (arg1, 1), 0)
2378 && operand_equal_p (TREE_OPERAND (arg0, 1),
2379 TREE_OPERAND (arg1, 0), 0));
2382 /* If either of the pointer (or reference) expressions we are dereferencing
2383 contain a side effect, these cannot be equal. */
2384 if (TREE_SIDE_EFFECTS (arg0)
2385 || TREE_SIDE_EFFECTS (arg1))
2388 switch (TREE_CODE (arg0))
2391 return operand_equal_p (TREE_OPERAND (arg0, 0),
2392 TREE_OPERAND (arg1, 0), 0);
2396 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2397 TREE_OPERAND (arg1, 0), 0)
2398 && operand_equal_p (TREE_OPERAND (arg0, 1),
2399 TREE_OPERAND (arg1, 1), 0));
2402 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2403 TREE_OPERAND (arg1, 0), 0)
2404 && operand_equal_p (TREE_OPERAND (arg0, 1),
2405 TREE_OPERAND (arg1, 1), 0)
2406 && operand_equal_p (TREE_OPERAND (arg0, 2),
2407 TREE_OPERAND (arg1, 2), 0));
2413 if (TREE_CODE (arg0) == RTL_EXPR)
2414 return rtx_equal_p (RTL_EXPR_RTL (arg0), RTL_EXPR_RTL (arg1));
2422 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2423 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2425 When in doubt, return 0. */
2428 operand_equal_for_comparison_p (arg0, arg1, other)
2432 int unsignedp1, unsignedpo;
2433 tree primarg0, primarg1, primother;
2434 unsigned int correct_width;
2436 if (operand_equal_p (arg0, arg1, 0))
2439 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
2440 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
2443 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2444 and see if the inner values are the same. This removes any
2445 signedness comparison, which doesn't matter here. */
2446 primarg0 = arg0, primarg1 = arg1;
2447 STRIP_NOPS (primarg0);
2448 STRIP_NOPS (primarg1);
2449 if (operand_equal_p (primarg0, primarg1, 0))
2452 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2453 actual comparison operand, ARG0.
2455 First throw away any conversions to wider types
2456 already present in the operands. */
2458 primarg1 = get_narrower (arg1, &unsignedp1);
2459 primother = get_narrower (other, &unsignedpo);
2461 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
2462 if (unsignedp1 == unsignedpo
2463 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
2464 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
2466 tree type = TREE_TYPE (arg0);
2468 /* Make sure shorter operand is extended the right way
2469 to match the longer operand. */
2470 primarg1 = convert (signed_or_unsigned_type (unsignedp1,
2471 TREE_TYPE (primarg1)),
2474 if (operand_equal_p (arg0, convert (type, primarg1), 0))
2481 /* See if ARG is an expression that is either a comparison or is performing
2482 arithmetic on comparisons. The comparisons must only be comparing
2483 two different values, which will be stored in *CVAL1 and *CVAL2; if
2484 they are non-zero it means that some operands have already been found.
2485 No variables may be used anywhere else in the expression except in the
2486 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2487 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2489 If this is true, return 1. Otherwise, return zero. */
2492 twoval_comparison_p (arg, cval1, cval2, save_p)
2494 tree *cval1, *cval2;
2497 enum tree_code code = TREE_CODE (arg);
2498 char class = TREE_CODE_CLASS (code);
2500 /* We can handle some of the 'e' cases here. */
2501 if (class == 'e' && code == TRUTH_NOT_EXPR)
2503 else if (class == 'e'
2504 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
2505 || code == COMPOUND_EXPR))
2508 else if (class == 'e' && code == SAVE_EXPR && SAVE_EXPR_RTL (arg) == 0
2509 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
2511 /* If we've already found a CVAL1 or CVAL2, this expression is
2512 two complex to handle. */
2513 if (*cval1 || *cval2)
2523 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
2526 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
2527 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2528 cval1, cval2, save_p));
2534 if (code == COND_EXPR)
2535 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
2536 cval1, cval2, save_p)
2537 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2538 cval1, cval2, save_p)
2539 && twoval_comparison_p (TREE_OPERAND (arg, 2),
2540 cval1, cval2, save_p));
2544 /* First see if we can handle the first operand, then the second. For
2545 the second operand, we know *CVAL1 can't be zero. It must be that
2546 one side of the comparison is each of the values; test for the
2547 case where this isn't true by failing if the two operands
2550 if (operand_equal_p (TREE_OPERAND (arg, 0),
2551 TREE_OPERAND (arg, 1), 0))
2555 *cval1 = TREE_OPERAND (arg, 0);
2556 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
2558 else if (*cval2 == 0)
2559 *cval2 = TREE_OPERAND (arg, 0);
2560 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
2565 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
2567 else if (*cval2 == 0)
2568 *cval2 = TREE_OPERAND (arg, 1);
2569 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
2581 /* ARG is a tree that is known to contain just arithmetic operations and
2582 comparisons. Evaluate the operations in the tree substituting NEW0 for
2583 any occurrence of OLD0 as an operand of a comparison and likewise for
2587 eval_subst (arg, old0, new0, old1, new1)
2589 tree old0, new0, old1, new1;
2591 tree type = TREE_TYPE (arg);
2592 enum tree_code code = TREE_CODE (arg);
2593 char class = TREE_CODE_CLASS (code);
2595 /* We can handle some of the 'e' cases here. */
2596 if (class == 'e' && code == TRUTH_NOT_EXPR)
2598 else if (class == 'e'
2599 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2605 return fold (build1 (code, type,
2606 eval_subst (TREE_OPERAND (arg, 0),
2607 old0, new0, old1, new1)));
2610 return fold (build (code, type,
2611 eval_subst (TREE_OPERAND (arg, 0),
2612 old0, new0, old1, new1),
2613 eval_subst (TREE_OPERAND (arg, 1),
2614 old0, new0, old1, new1)));
2620 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
2623 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
2626 return fold (build (code, type,
2627 eval_subst (TREE_OPERAND (arg, 0),
2628 old0, new0, old1, new1),
2629 eval_subst (TREE_OPERAND (arg, 1),
2630 old0, new0, old1, new1),
2631 eval_subst (TREE_OPERAND (arg, 2),
2632 old0, new0, old1, new1)));
2636 /* fall through - ??? */
2640 tree arg0 = TREE_OPERAND (arg, 0);
2641 tree arg1 = TREE_OPERAND (arg, 1);
2643 /* We need to check both for exact equality and tree equality. The
2644 former will be true if the operand has a side-effect. In that
2645 case, we know the operand occurred exactly once. */
2647 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
2649 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
2652 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
2654 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
2657 return fold (build (code, type, arg0, arg1));
2665 /* Return a tree for the case when the result of an expression is RESULT
2666 converted to TYPE and OMITTED was previously an operand of the expression
2667 but is now not needed (e.g., we folded OMITTED * 0).
2669 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2670 the conversion of RESULT to TYPE. */
2673 omit_one_operand (type, result, omitted)
2674 tree type, result, omitted;
2676 tree t = convert (type, result);
2678 if (TREE_SIDE_EFFECTS (omitted))
2679 return build (COMPOUND_EXPR, type, omitted, t);
2681 return non_lvalue (t);
2684 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2687 pedantic_omit_one_operand (type, result, omitted)
2688 tree type, result, omitted;
2690 tree t = convert (type, result);
2692 if (TREE_SIDE_EFFECTS (omitted))
2693 return build (COMPOUND_EXPR, type, omitted, t);
2695 return pedantic_non_lvalue (t);
2698 /* Return a simplified tree node for the truth-negation of ARG. This
2699 never alters ARG itself. We assume that ARG is an operation that
2700 returns a truth value (0 or 1). */
2703 invert_truthvalue (arg)
2706 tree type = TREE_TYPE (arg);
2707 enum tree_code code = TREE_CODE (arg);
2709 if (code == ERROR_MARK)
2712 /* If this is a comparison, we can simply invert it, except for
2713 floating-point non-equality comparisons, in which case we just
2714 enclose a TRUTH_NOT_EXPR around what we have. */
2716 if (TREE_CODE_CLASS (code) == '<')
2718 if (FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg, 0)))
2719 && !flag_fast_math && code != NE_EXPR && code != EQ_EXPR)
2720 return build1 (TRUTH_NOT_EXPR, type, arg);
2722 return build (invert_tree_comparison (code), type,
2723 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
2729 return convert (type, build_int_2 (integer_zerop (arg), 0));
2731 case TRUTH_AND_EXPR:
2732 return build (TRUTH_OR_EXPR, type,
2733 invert_truthvalue (TREE_OPERAND (arg, 0)),
2734 invert_truthvalue (TREE_OPERAND (arg, 1)));
2737 return build (TRUTH_AND_EXPR, type,
2738 invert_truthvalue (TREE_OPERAND (arg, 0)),
2739 invert_truthvalue (TREE_OPERAND (arg, 1)));
2741 case TRUTH_XOR_EXPR:
2742 /* Here we can invert either operand. We invert the first operand
2743 unless the second operand is a TRUTH_NOT_EXPR in which case our
2744 result is the XOR of the first operand with the inside of the
2745 negation of the second operand. */
2747 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
2748 return build (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
2749 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
2751 return build (TRUTH_XOR_EXPR, type,
2752 invert_truthvalue (TREE_OPERAND (arg, 0)),
2753 TREE_OPERAND (arg, 1));
2755 case TRUTH_ANDIF_EXPR:
2756 return build (TRUTH_ORIF_EXPR, type,
2757 invert_truthvalue (TREE_OPERAND (arg, 0)),
2758 invert_truthvalue (TREE_OPERAND (arg, 1)));
2760 case TRUTH_ORIF_EXPR:
2761 return build (TRUTH_ANDIF_EXPR, type,
2762 invert_truthvalue (TREE_OPERAND (arg, 0)),
2763 invert_truthvalue (TREE_OPERAND (arg, 1)));
2765 case TRUTH_NOT_EXPR:
2766 return TREE_OPERAND (arg, 0);
2769 return build (COND_EXPR, type, TREE_OPERAND (arg, 0),
2770 invert_truthvalue (TREE_OPERAND (arg, 1)),
2771 invert_truthvalue (TREE_OPERAND (arg, 2)));
2774 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
2775 invert_truthvalue (TREE_OPERAND (arg, 1)));
2777 case WITH_RECORD_EXPR:
2778 return build (WITH_RECORD_EXPR, type,
2779 invert_truthvalue (TREE_OPERAND (arg, 0)),
2780 TREE_OPERAND (arg, 1));
2782 case NON_LVALUE_EXPR:
2783 return invert_truthvalue (TREE_OPERAND (arg, 0));
2788 return build1 (TREE_CODE (arg), type,
2789 invert_truthvalue (TREE_OPERAND (arg, 0)));
2792 if (!integer_onep (TREE_OPERAND (arg, 1)))
2794 return build (EQ_EXPR, type, arg, convert (type, integer_zero_node));
2797 return build1 (TRUTH_NOT_EXPR, type, arg);
2799 case CLEANUP_POINT_EXPR:
2800 return build1 (CLEANUP_POINT_EXPR, type,
2801 invert_truthvalue (TREE_OPERAND (arg, 0)));
2806 if (TREE_CODE (TREE_TYPE (arg)) != BOOLEAN_TYPE)
2808 return build1 (TRUTH_NOT_EXPR, type, arg);
2811 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
2812 operands are another bit-wise operation with a common input. If so,
2813 distribute the bit operations to save an operation and possibly two if
2814 constants are involved. For example, convert
2815 (A | B) & (A | C) into A | (B & C)
2816 Further simplification will occur if B and C are constants.
2818 If this optimization cannot be done, 0 will be returned. */
2821 distribute_bit_expr (code, type, arg0, arg1)
2822 enum tree_code code;
2829 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2830 || TREE_CODE (arg0) == code
2831 || (TREE_CODE (arg0) != BIT_AND_EXPR
2832 && TREE_CODE (arg0) != BIT_IOR_EXPR))
2835 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
2837 common = TREE_OPERAND (arg0, 0);
2838 left = TREE_OPERAND (arg0, 1);
2839 right = TREE_OPERAND (arg1, 1);
2841 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
2843 common = TREE_OPERAND (arg0, 0);
2844 left = TREE_OPERAND (arg0, 1);
2845 right = TREE_OPERAND (arg1, 0);
2847 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
2849 common = TREE_OPERAND (arg0, 1);
2850 left = TREE_OPERAND (arg0, 0);
2851 right = TREE_OPERAND (arg1, 1);
2853 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
2855 common = TREE_OPERAND (arg0, 1);
2856 left = TREE_OPERAND (arg0, 0);
2857 right = TREE_OPERAND (arg1, 0);
2862 return fold (build (TREE_CODE (arg0), type, common,
2863 fold (build (code, type, left, right))));
2866 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
2867 starting at BITPOS. The field is unsigned if UNSIGNEDP is non-zero. */
2870 make_bit_field_ref (inner, type, bitsize, bitpos, unsignedp)
2873 int bitsize, bitpos;
2876 tree result = build (BIT_FIELD_REF, type, inner,
2877 size_int (bitsize), bitsize_int (bitpos));
2879 TREE_UNSIGNED (result) = unsignedp;
2884 /* Optimize a bit-field compare.
2886 There are two cases: First is a compare against a constant and the
2887 second is a comparison of two items where the fields are at the same
2888 bit position relative to the start of a chunk (byte, halfword, word)
2889 large enough to contain it. In these cases we can avoid the shift
2890 implicit in bitfield extractions.
2892 For constants, we emit a compare of the shifted constant with the
2893 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
2894 compared. For two fields at the same position, we do the ANDs with the
2895 similar mask and compare the result of the ANDs.
2897 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
2898 COMPARE_TYPE is the type of the comparison, and LHS and RHS
2899 are the left and right operands of the comparison, respectively.
2901 If the optimization described above can be done, we return the resulting
2902 tree. Otherwise we return zero. */
2905 optimize_bit_field_compare (code, compare_type, lhs, rhs)
2906 enum tree_code code;
2910 HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
2911 tree type = TREE_TYPE (lhs);
2912 tree signed_type, unsigned_type;
2913 int const_p = TREE_CODE (rhs) == INTEGER_CST;
2914 enum machine_mode lmode, rmode, nmode;
2915 int lunsignedp, runsignedp;
2916 int lvolatilep = 0, rvolatilep = 0;
2917 unsigned int alignment;
2918 tree linner, rinner = NULL_TREE;
2922 /* Get all the information about the extractions being done. If the bit size
2923 if the same as the size of the underlying object, we aren't doing an
2924 extraction at all and so can do nothing. We also don't want to
2925 do anything if the inner expression is a PLACEHOLDER_EXPR since we
2926 then will no longer be able to replace it. */
2927 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
2928 &lunsignedp, &lvolatilep, &alignment);
2929 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
2930 || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
2935 /* If this is not a constant, we can only do something if bit positions,
2936 sizes, and signedness are the same. */
2937 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
2938 &runsignedp, &rvolatilep, &alignment);
2940 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
2941 || lunsignedp != runsignedp || offset != 0
2942 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
2946 /* See if we can find a mode to refer to this field. We should be able to,
2947 but fail if we can't. */
2948 nmode = get_best_mode (lbitsize, lbitpos,
2949 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
2950 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
2951 TYPE_ALIGN (TREE_TYPE (rinner))),
2952 word_mode, lvolatilep || rvolatilep);
2953 if (nmode == VOIDmode)
2956 /* Set signed and unsigned types of the precision of this mode for the
2958 signed_type = type_for_mode (nmode, 0);
2959 unsigned_type = type_for_mode (nmode, 1);
2961 /* Compute the bit position and size for the new reference and our offset
2962 within it. If the new reference is the same size as the original, we
2963 won't optimize anything, so return zero. */
2964 nbitsize = GET_MODE_BITSIZE (nmode);
2965 nbitpos = lbitpos & ~ (nbitsize - 1);
2967 if (nbitsize == lbitsize)
2970 if (BYTES_BIG_ENDIAN)
2971 lbitpos = nbitsize - lbitsize - lbitpos;
2973 /* Make the mask to be used against the extracted field. */
2974 mask = build_int_2 (~0, ~0);
2975 TREE_TYPE (mask) = unsigned_type;
2976 force_fit_type (mask, 0);
2977 mask = convert (unsigned_type, mask);
2978 mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
2979 mask = const_binop (RSHIFT_EXPR, mask,
2980 size_int (nbitsize - lbitsize - lbitpos), 0);
2983 /* If not comparing with constant, just rework the comparison
2985 return build (code, compare_type,
2986 build (BIT_AND_EXPR, unsigned_type,
2987 make_bit_field_ref (linner, unsigned_type,
2988 nbitsize, nbitpos, 1),
2990 build (BIT_AND_EXPR, unsigned_type,
2991 make_bit_field_ref (rinner, unsigned_type,
2992 nbitsize, nbitpos, 1),
2995 /* Otherwise, we are handling the constant case. See if the constant is too
2996 big for the field. Warn and return a tree of for 0 (false) if so. We do
2997 this not only for its own sake, but to avoid having to test for this
2998 error case below. If we didn't, we might generate wrong code.
3000 For unsigned fields, the constant shifted right by the field length should
3001 be all zero. For signed fields, the high-order bits should agree with
3006 if (! integer_zerop (const_binop (RSHIFT_EXPR,
3007 convert (unsigned_type, rhs),
3008 size_int (lbitsize), 0)))
3010 warning ("comparison is always %d due to width of bitfield",
3012 return convert (compare_type,
3014 ? integer_one_node : integer_zero_node));
3019 tree tem = const_binop (RSHIFT_EXPR, convert (signed_type, rhs),
3020 size_int (lbitsize - 1), 0);
3021 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
3023 warning ("comparison is always %d due to width of bitfield",
3025 return convert (compare_type,
3027 ? integer_one_node : integer_zero_node));
3031 /* Single-bit compares should always be against zero. */
3032 if (lbitsize == 1 && ! integer_zerop (rhs))
3034 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
3035 rhs = convert (type, integer_zero_node);
3038 /* Make a new bitfield reference, shift the constant over the
3039 appropriate number of bits and mask it with the computed mask
3040 (in case this was a signed field). If we changed it, make a new one. */
3041 lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1);
3044 TREE_SIDE_EFFECTS (lhs) = 1;
3045 TREE_THIS_VOLATILE (lhs) = 1;
3048 rhs = fold (const_binop (BIT_AND_EXPR,
3049 const_binop (LSHIFT_EXPR,
3050 convert (unsigned_type, rhs),
3051 size_int (lbitpos), 0),
3054 return build (code, compare_type,
3055 build (BIT_AND_EXPR, unsigned_type, lhs, mask),
3059 /* Subroutine for fold_truthop: decode a field reference.
3061 If EXP is a comparison reference, we return the innermost reference.
3063 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
3064 set to the starting bit number.
3066 If the innermost field can be completely contained in a mode-sized
3067 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
3069 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
3070 otherwise it is not changed.
3072 *PUNSIGNEDP is set to the signedness of the field.
3074 *PMASK is set to the mask used. This is either contained in a
3075 BIT_AND_EXPR or derived from the width of the field.
3077 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
3079 Return 0 if this is not a component reference or is one that we can't
3080 do anything with. */
3083 decode_field_reference (exp, pbitsize, pbitpos, pmode, punsignedp,
3084 pvolatilep, pmask, pand_mask)
3086 HOST_WIDE_INT *pbitsize, *pbitpos;
3087 enum machine_mode *pmode;
3088 int *punsignedp, *pvolatilep;
3093 tree mask, inner, offset;
3095 unsigned int precision;
3096 unsigned int alignment;
3098 /* All the optimizations using this function assume integer fields.
3099 There are problems with FP fields since the type_for_size call
3100 below can fail for, e.g., XFmode. */
3101 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
3106 if (TREE_CODE (exp) == BIT_AND_EXPR)
3108 and_mask = TREE_OPERAND (exp, 1);
3109 exp = TREE_OPERAND (exp, 0);
3110 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
3111 if (TREE_CODE (and_mask) != INTEGER_CST)
3115 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
3116 punsignedp, pvolatilep, &alignment);
3117 if ((inner == exp && and_mask == 0)
3118 || *pbitsize < 0 || offset != 0
3119 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
3122 /* Compute the mask to access the bitfield. */
3123 unsigned_type = type_for_size (*pbitsize, 1);
3124 precision = TYPE_PRECISION (unsigned_type);
3126 mask = build_int_2 (~0, ~0);
3127 TREE_TYPE (mask) = unsigned_type;
3128 force_fit_type (mask, 0);
3129 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3130 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3132 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
3134 mask = fold (build (BIT_AND_EXPR, unsigned_type,
3135 convert (unsigned_type, and_mask), mask));
3138 *pand_mask = and_mask;
3142 /* Return non-zero if MASK represents a mask of SIZE ones in the low-order
3146 all_ones_mask_p (mask, size)
3150 tree type = TREE_TYPE (mask);
3151 unsigned int precision = TYPE_PRECISION (type);
3154 tmask = build_int_2 (~0, ~0);
3155 TREE_TYPE (tmask) = signed_type (type);
3156 force_fit_type (tmask, 0);
3158 tree_int_cst_equal (mask,
3159 const_binop (RSHIFT_EXPR,
3160 const_binop (LSHIFT_EXPR, tmask,
3161 size_int (precision - size),
3163 size_int (precision - size), 0));
3166 /* Subroutine for fold_truthop: determine if an operand is simple enough
3167 to be evaluated unconditionally. */
3170 simple_operand_p (exp)
3173 /* Strip any conversions that don't change the machine mode. */
3174 while ((TREE_CODE (exp) == NOP_EXPR
3175 || TREE_CODE (exp) == CONVERT_EXPR)
3176 && (TYPE_MODE (TREE_TYPE (exp))
3177 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)))))
3178 exp = TREE_OPERAND (exp, 0);
3180 return (TREE_CODE_CLASS (TREE_CODE (exp)) == 'c'
3182 && ! TREE_ADDRESSABLE (exp)
3183 && ! TREE_THIS_VOLATILE (exp)
3184 && ! DECL_NONLOCAL (exp)
3185 /* Don't regard global variables as simple. They may be
3186 allocated in ways unknown to the compiler (shared memory,
3187 #pragma weak, etc). */
3188 && ! TREE_PUBLIC (exp)
3189 && ! DECL_EXTERNAL (exp)
3190 /* Loading a static variable is unduly expensive, but global
3191 registers aren't expensive. */
3192 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
3195 /* The following functions are subroutines to fold_range_test and allow it to
3196 try to change a logical combination of comparisons into a range test.
3199 X == 2 || X == 3 || X == 4 || X == 5
3203 (unsigned) (X - 2) <= 3
3205 We describe each set of comparisons as being either inside or outside
3206 a range, using a variable named like IN_P, and then describe the
3207 range with a lower and upper bound. If one of the bounds is omitted,
3208 it represents either the highest or lowest value of the type.
3210 In the comments below, we represent a range by two numbers in brackets
3211 preceded by a "+" to designate being inside that range, or a "-" to
3212 designate being outside that range, so the condition can be inverted by
3213 flipping the prefix. An omitted bound is represented by a "-". For
3214 example, "- [-, 10]" means being outside the range starting at the lowest
3215 possible value and ending at 10, in other words, being greater than 10.
3216 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
3219 We set up things so that the missing bounds are handled in a consistent
3220 manner so neither a missing bound nor "true" and "false" need to be
3221 handled using a special case. */
3223 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
3224 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
3225 and UPPER1_P are nonzero if the respective argument is an upper bound
3226 and zero for a lower. TYPE, if nonzero, is the type of the result; it
3227 must be specified for a comparison. ARG1 will be converted to ARG0's
3228 type if both are specified. */
3231 range_binop (code, type, arg0, upper0_p, arg1, upper1_p)
3232 enum tree_code code;
3235 int upper0_p, upper1_p;
3241 /* If neither arg represents infinity, do the normal operation.
3242 Else, if not a comparison, return infinity. Else handle the special
3243 comparison rules. Note that most of the cases below won't occur, but
3244 are handled for consistency. */
3246 if (arg0 != 0 && arg1 != 0)
3248 tem = fold (build (code, type != 0 ? type : TREE_TYPE (arg0),
3249 arg0, convert (TREE_TYPE (arg0), arg1)));
3251 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
3254 if (TREE_CODE_CLASS (code) != '<')
3257 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
3258 for neither. In real maths, we cannot assume open ended ranges are
3259 the same. But, this is computer arithmetic, where numbers are finite.
3260 We can therefore make the transformation of any unbounded range with
3261 the value Z, Z being greater than any representable number. This permits
3262 us to treat unbounded ranges as equal. */
3263 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
3264 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
3268 result = sgn0 == sgn1;
3271 result = sgn0 != sgn1;
3274 result = sgn0 < sgn1;
3277 result = sgn0 <= sgn1;
3280 result = sgn0 > sgn1;
3283 result = sgn0 >= sgn1;
3289 return convert (type, result ? integer_one_node : integer_zero_node);
3292 /* Given EXP, a logical expression, set the range it is testing into
3293 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
3294 actually being tested. *PLOW and *PHIGH will be made of the same type
3295 as the returned expression. If EXP is not a comparison, we will most
3296 likely not be returning a useful value and range. */
3299 make_range (exp, pin_p, plow, phigh)
3304 enum tree_code code;
3305 tree arg0 = NULL_TREE, arg1 = NULL_TREE, type = NULL_TREE;
3306 tree orig_type = NULL_TREE;
3308 tree low, high, n_low, n_high;
3310 /* Start with simply saying "EXP != 0" and then look at the code of EXP
3311 and see if we can refine the range. Some of the cases below may not
3312 happen, but it doesn't seem worth worrying about this. We "continue"
3313 the outer loop when we've changed something; otherwise we "break"
3314 the switch, which will "break" the while. */
3316 in_p = 0, low = high = convert (TREE_TYPE (exp), integer_zero_node);
3320 code = TREE_CODE (exp);
3322 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
3324 arg0 = TREE_OPERAND (exp, 0);
3325 if (TREE_CODE_CLASS (code) == '<'
3326 || TREE_CODE_CLASS (code) == '1'
3327 || TREE_CODE_CLASS (code) == '2')
3328 type = TREE_TYPE (arg0);
3329 if (TREE_CODE_CLASS (code) == '2'
3330 || TREE_CODE_CLASS (code) == '<'
3331 || (TREE_CODE_CLASS (code) == 'e'
3332 && TREE_CODE_LENGTH (code) > 1))
3333 arg1 = TREE_OPERAND (exp, 1);
3336 /* Set ORIG_TYPE as soon as TYPE is non-null so that we do not
3337 lose a cast by accident. */
3338 if (type != NULL_TREE && orig_type == NULL_TREE)
3343 case TRUTH_NOT_EXPR:
3344 in_p = ! in_p, exp = arg0;
3347 case EQ_EXPR: case NE_EXPR:
3348 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
3349 /* We can only do something if the range is testing for zero
3350 and if the second operand is an integer constant. Note that
3351 saying something is "in" the range we make is done by
3352 complementing IN_P since it will set in the initial case of
3353 being not equal to zero; "out" is leaving it alone. */
3354 if (low == 0 || high == 0
3355 || ! integer_zerop (low) || ! integer_zerop (high)
3356 || TREE_CODE (arg1) != INTEGER_CST)
3361 case NE_EXPR: /* - [c, c] */
3364 case EQ_EXPR: /* + [c, c] */
3365 in_p = ! in_p, low = high = arg1;
3367 case GT_EXPR: /* - [-, c] */
3368 low = 0, high = arg1;
3370 case GE_EXPR: /* + [c, -] */
3371 in_p = ! in_p, low = arg1, high = 0;
3373 case LT_EXPR: /* - [c, -] */
3374 low = arg1, high = 0;
3376 case LE_EXPR: /* + [-, c] */
3377 in_p = ! in_p, low = 0, high = arg1;
3385 /* If this is an unsigned comparison, we also know that EXP is
3386 greater than or equal to zero. We base the range tests we make
3387 on that fact, so we record it here so we can parse existing
3389 if (TREE_UNSIGNED (type) && (low == 0 || high == 0))
3391 if (! merge_ranges (&n_in_p, &n_low, &n_high, in_p, low, high,
3392 1, convert (type, integer_zero_node),
3396 in_p = n_in_p, low = n_low, high = n_high;
3398 /* If the high bound is missing, but we
3399 have a low bound, reverse the range so
3400 it goes from zero to the low bound minus 1. */
3401 if (high == 0 && low)
3404 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
3405 integer_one_node, 0);
3406 low = convert (type, integer_zero_node);
3412 /* (-x) IN [a,b] -> x in [-b, -a] */
3413 n_low = range_binop (MINUS_EXPR, type,
3414 convert (type, integer_zero_node), 0, high, 1);
3415 n_high = range_binop (MINUS_EXPR, type,
3416 convert (type, integer_zero_node), 0, low, 0);
3417 low = n_low, high = n_high;
3423 exp = build (MINUS_EXPR, type, negate_expr (arg0),
3424 convert (type, integer_one_node));
3427 case PLUS_EXPR: case MINUS_EXPR:
3428 if (TREE_CODE (arg1) != INTEGER_CST)
3431 /* If EXP is signed, any overflow in the computation is undefined,
3432 so we don't worry about it so long as our computations on
3433 the bounds don't overflow. For unsigned, overflow is defined
3434 and this is exactly the right thing. */
3435 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3436 type, low, 0, arg1, 0);
3437 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3438 type, high, 1, arg1, 0);
3439 if ((n_low != 0 && TREE_OVERFLOW (n_low))
3440 || (n_high != 0 && TREE_OVERFLOW (n_high)))
3443 /* Check for an unsigned range which has wrapped around the maximum
3444 value thus making n_high < n_low, and normalize it. */
3445 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
3447 low = range_binop (PLUS_EXPR, type, n_high, 0,
3448 integer_one_node, 0);
3449 high = range_binop (MINUS_EXPR, type, n_low, 0,
3450 integer_one_node, 0);
3452 /* If the range is of the form +/- [ x+1, x ], we won't
3453 be able to normalize it. But then, it represents the
3454 whole range or the empty set, so make it
3456 if (tree_int_cst_equal (n_low, low)
3457 && tree_int_cst_equal (n_high, high))
3463 low = n_low, high = n_high;
3468 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
3469 if (TYPE_PRECISION (type) > TYPE_PRECISION (orig_type))
3472 if (! INTEGRAL_TYPE_P (type)
3473 || (low != 0 && ! int_fits_type_p (low, type))
3474 || (high != 0 && ! int_fits_type_p (high, type)))
3477 n_low = low, n_high = high;
3480 n_low = convert (type, n_low);
3483 n_high = convert (type, n_high);
3485 /* If we're converting from an unsigned to a signed type,
3486 we will be doing the comparison as unsigned. The tests above
3487 have already verified that LOW and HIGH are both positive.
3489 So we have to make sure that the original unsigned value will
3490 be interpreted as positive. */
3491 if (TREE_UNSIGNED (type) && ! TREE_UNSIGNED (TREE_TYPE (exp)))
3493 tree equiv_type = type_for_mode (TYPE_MODE (type), 1);
3496 /* A range without an upper bound is, naturally, unbounded.
3497 Since convert would have cropped a very large value, use
3498 the max value for the destination type. */
3500 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
3501 : TYPE_MAX_VALUE (type);
3503 high_positive = fold (build (RSHIFT_EXPR, type,
3504 convert (type, high_positive),
3505 convert (type, integer_one_node)));
3507 /* If the low bound is specified, "and" the range with the
3508 range for which the original unsigned value will be
3512 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3514 1, convert (type, integer_zero_node),
3518 in_p = (n_in_p == in_p);
3522 /* Otherwise, "or" the range with the range of the input
3523 that will be interpreted as negative. */
3524 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3526 1, convert (type, integer_zero_node),
3530 in_p = (in_p != n_in_p);
3535 low = n_low, high = n_high;
3545 /* If EXP is a constant, we can evaluate whether this is true or false. */
3546 if (TREE_CODE (exp) == INTEGER_CST)
3548 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
3550 && integer_onep (range_binop (LE_EXPR, integer_type_node,
3556 *pin_p = in_p, *plow = low, *phigh = high;
3560 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3561 type, TYPE, return an expression to test if EXP is in (or out of, depending
3562 on IN_P) the range. */
3565 build_range_check (type, exp, in_p, low, high)
3571 tree etype = TREE_TYPE (exp);
3575 && (0 != (value = build_range_check (type, exp, 1, low, high))))
3576 return invert_truthvalue (value);
3578 else if (low == 0 && high == 0)
3579 return convert (type, integer_one_node);
3582 return fold (build (LE_EXPR, type, exp, high));
3585 return fold (build (GE_EXPR, type, exp, low));
3587 else if (operand_equal_p (low, high, 0))
3588 return fold (build (EQ_EXPR, type, exp, low));
3590 else if (TREE_UNSIGNED (etype) && integer_zerop (low))
3591 return build_range_check (type, exp, 1, 0, high);
3593 else if (integer_zerop (low))
3595 utype = unsigned_type (etype);
3596 return build_range_check (type, convert (utype, exp), 1, 0,
3597 convert (utype, high));
3600 else if (0 != (value = const_binop (MINUS_EXPR, high, low, 0))
3601 && ! TREE_OVERFLOW (value))
3602 return build_range_check (type,
3603 fold (build (MINUS_EXPR, etype, exp, low)),
3604 1, convert (etype, integer_zero_node), value);
3609 /* Given two ranges, see if we can merge them into one. Return 1 if we
3610 can, 0 if we can't. Set the output range into the specified parameters. */
3613 merge_ranges (pin_p, plow, phigh, in0_p, low0, high0, in1_p, low1, high1)
3617 tree low0, high0, low1, high1;
3625 int lowequal = ((low0 == 0 && low1 == 0)
3626 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3627 low0, 0, low1, 0)));
3628 int highequal = ((high0 == 0 && high1 == 0)
3629 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3630 high0, 1, high1, 1)));
3632 /* Make range 0 be the range that starts first, or ends last if they
3633 start at the same value. Swap them if it isn't. */
3634 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
3637 && integer_onep (range_binop (GT_EXPR, integer_type_node,
3638 high1, 1, high0, 1))))
3640 temp = in0_p, in0_p = in1_p, in1_p = temp;
3641 tem = low0, low0 = low1, low1 = tem;
3642 tem = high0, high0 = high1, high1 = tem;
3645 /* Now flag two cases, whether the ranges are disjoint or whether the
3646 second range is totally subsumed in the first. Note that the tests
3647 below are simplified by the ones above. */
3648 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
3649 high0, 1, low1, 0));
3650 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
3651 high1, 1, high0, 1));
3653 /* We now have four cases, depending on whether we are including or
3654 excluding the two ranges. */
3657 /* If they don't overlap, the result is false. If the second range
3658 is a subset it is the result. Otherwise, the range is from the start
3659 of the second to the end of the first. */
3661 in_p = 0, low = high = 0;
3663 in_p = 1, low = low1, high = high1;
3665 in_p = 1, low = low1, high = high0;
3668 else if (in0_p && ! in1_p)
3670 /* If they don't overlap, the result is the first range. If they are
3671 equal, the result is false. If the second range is a subset of the
3672 first, and the ranges begin at the same place, we go from just after
3673 the end of the first range to the end of the second. If the second
3674 range is not a subset of the first, or if it is a subset and both
3675 ranges end at the same place, the range starts at the start of the
3676 first range and ends just before the second range.
3677 Otherwise, we can't describe this as a single range. */
3679 in_p = 1, low = low0, high = high0;
3680 else if (lowequal && highequal)
3681 in_p = 0, low = high = 0;
3682 else if (subset && lowequal)
3684 in_p = 1, high = high0;
3685 low = range_binop (PLUS_EXPR, NULL_TREE, high1, 0,
3686 integer_one_node, 0);
3688 else if (! subset || highequal)
3690 in_p = 1, low = low0;
3691 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
3692 integer_one_node, 0);
3698 else if (! in0_p && in1_p)
3700 /* If they don't overlap, the result is the second range. If the second
3701 is a subset of the first, the result is false. Otherwise,
3702 the range starts just after the first range and ends at the
3703 end of the second. */
3705 in_p = 1, low = low1, high = high1;
3706 else if (subset || highequal)
3707 in_p = 0, low = high = 0;
3710 in_p = 1, high = high1;
3711 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
3712 integer_one_node, 0);
3718 /* The case where we are excluding both ranges. Here the complex case
3719 is if they don't overlap. In that case, the only time we have a
3720 range is if they are adjacent. If the second is a subset of the
3721 first, the result is the first. Otherwise, the range to exclude
3722 starts at the beginning of the first range and ends at the end of the
3726 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
3727 range_binop (PLUS_EXPR, NULL_TREE,
3729 integer_one_node, 1),
3731 in_p = 0, low = low0, high = high1;
3736 in_p = 0, low = low0, high = high0;
3738 in_p = 0, low = low0, high = high1;
3741 *pin_p = in_p, *plow = low, *phigh = high;
3745 /* EXP is some logical combination of boolean tests. See if we can
3746 merge it into some range test. Return the new tree if so. */
3749 fold_range_test (exp)
3752 int or_op = (TREE_CODE (exp) == TRUTH_ORIF_EXPR
3753 || TREE_CODE (exp) == TRUTH_OR_EXPR);
3754 int in0_p, in1_p, in_p;
3755 tree low0, low1, low, high0, high1, high;
3756 tree lhs = make_range (TREE_OPERAND (exp, 0), &in0_p, &low0, &high0);
3757 tree rhs = make_range (TREE_OPERAND (exp, 1), &in1_p, &low1, &high1);
3760 /* If this is an OR operation, invert both sides; we will invert
3761 again at the end. */
3763 in0_p = ! in0_p, in1_p = ! in1_p;
3765 /* If both expressions are the same, if we can merge the ranges, and we
3766 can build the range test, return it or it inverted. If one of the
3767 ranges is always true or always false, consider it to be the same
3768 expression as the other. */
3769 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
3770 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
3772 && 0 != (tem = (build_range_check (TREE_TYPE (exp),
3774 : rhs != 0 ? rhs : integer_zero_node,
3776 return or_op ? invert_truthvalue (tem) : tem;
3778 /* On machines where the branch cost is expensive, if this is a
3779 short-circuited branch and the underlying object on both sides
3780 is the same, make a non-short-circuit operation. */
3781 else if (BRANCH_COST >= 2
3782 && (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3783 || TREE_CODE (exp) == TRUTH_ORIF_EXPR)
3784 && operand_equal_p (lhs, rhs, 0))
3786 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
3787 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
3788 which cases we can't do this. */
3789 if (simple_operand_p (lhs))
3790 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3791 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3792 TREE_TYPE (exp), TREE_OPERAND (exp, 0),
3793 TREE_OPERAND (exp, 1));
3795 else if (global_bindings_p () == 0
3796 && ! contains_placeholder_p (lhs))
3798 tree common = save_expr (lhs);
3800 if (0 != (lhs = build_range_check (TREE_TYPE (exp), common,
3801 or_op ? ! in0_p : in0_p,
3803 && (0 != (rhs = build_range_check (TREE_TYPE (exp), common,
3804 or_op ? ! in1_p : in1_p,
3806 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3807 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3808 TREE_TYPE (exp), lhs, rhs);
3815 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
3816 bit value. Arrange things so the extra bits will be set to zero if and
3817 only if C is signed-extended to its full width. If MASK is nonzero,
3818 it is an INTEGER_CST that should be AND'ed with the extra bits. */
3821 unextend (c, p, unsignedp, mask)
3827 tree type = TREE_TYPE (c);
3828 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
3831 if (p == modesize || unsignedp)
3834 /* We work by getting just the sign bit into the low-order bit, then
3835 into the high-order bit, then sign-extend. We then XOR that value
3837 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
3838 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
3840 /* We must use a signed type in order to get an arithmetic right shift.
3841 However, we must also avoid introducing accidental overflows, so that
3842 a subsequent call to integer_zerop will work. Hence we must
3843 do the type conversion here. At this point, the constant is either
3844 zero or one, and the conversion to a signed type can never overflow.
3845 We could get an overflow if this conversion is done anywhere else. */
3846 if (TREE_UNSIGNED (type))
3847 temp = convert (signed_type (type), temp);
3849 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
3850 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
3852 temp = const_binop (BIT_AND_EXPR, temp, convert (TREE_TYPE (c), mask), 0);
3853 /* If necessary, convert the type back to match the type of C. */
3854 if (TREE_UNSIGNED (type))
3855 temp = convert (type, temp);
3857 return convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
3860 /* Find ways of folding logical expressions of LHS and RHS:
3861 Try to merge two comparisons to the same innermost item.
3862 Look for range tests like "ch >= '0' && ch <= '9'".
3863 Look for combinations of simple terms on machines with expensive branches
3864 and evaluate the RHS unconditionally.
3866 For example, if we have p->a == 2 && p->b == 4 and we can make an
3867 object large enough to span both A and B, we can do this with a comparison
3868 against the object ANDed with the a mask.
3870 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
3871 operations to do this with one comparison.
3873 We check for both normal comparisons and the BIT_AND_EXPRs made this by
3874 function and the one above.
3876 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
3877 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
3879 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
3882 We return the simplified tree or 0 if no optimization is possible. */
3885 fold_truthop (code, truth_type, lhs, rhs)
3886 enum tree_code code;
3887 tree truth_type, lhs, rhs;
3889 /* If this is the "or" of two comparisons, we can do something if
3890 the comparisons are NE_EXPR. If this is the "and", we can do something
3891 if the comparisons are EQ_EXPR. I.e.,
3892 (a->b == 2 && a->c == 4) can become (a->new == NEW).
3894 WANTED_CODE is this operation code. For single bit fields, we can
3895 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
3896 comparison for one-bit fields. */
3898 enum tree_code wanted_code;
3899 enum tree_code lcode, rcode;
3900 tree ll_arg, lr_arg, rl_arg, rr_arg;
3901 tree ll_inner, lr_inner, rl_inner, rr_inner;
3902 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
3903 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
3904 HOST_WIDE_INT xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
3905 HOST_WIDE_INT lnbitsize, lnbitpos, rnbitsize, rnbitpos;
3906 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
3907 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
3908 enum machine_mode lnmode, rnmode;
3909 tree ll_mask, lr_mask, rl_mask, rr_mask;
3910 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
3911 tree l_const, r_const;
3912 tree lntype, rntype, result;
3913 int first_bit, end_bit;
3916 /* Start by getting the comparison codes. Fail if anything is volatile.
3917 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
3918 it were surrounded with a NE_EXPR. */
3920 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
3923 lcode = TREE_CODE (lhs);
3924 rcode = TREE_CODE (rhs);
3926 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
3927 lcode = NE_EXPR, lhs = build (NE_EXPR, truth_type, lhs, integer_zero_node);
3929 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
3930 rcode = NE_EXPR, rhs = build (NE_EXPR, truth_type, rhs, integer_zero_node);
3932 if (TREE_CODE_CLASS (lcode) != '<' || TREE_CODE_CLASS (rcode) != '<')
3935 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
3936 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
3938 ll_arg = TREE_OPERAND (lhs, 0);
3939 lr_arg = TREE_OPERAND (lhs, 1);
3940 rl_arg = TREE_OPERAND (rhs, 0);
3941 rr_arg = TREE_OPERAND (rhs, 1);
3943 /* If the RHS can be evaluated unconditionally and its operands are
3944 simple, it wins to evaluate the RHS unconditionally on machines
3945 with expensive branches. In this case, this isn't a comparison
3946 that can be merged. Avoid doing this if the RHS is a floating-point
3947 comparison since those can trap. */
3949 if (BRANCH_COST >= 2
3950 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
3951 && simple_operand_p (rl_arg)
3952 && simple_operand_p (rr_arg))
3953 return build (code, truth_type, lhs, rhs);
3955 /* See if the comparisons can be merged. Then get all the parameters for
3958 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
3959 || (rcode != EQ_EXPR && rcode != NE_EXPR))
3963 ll_inner = decode_field_reference (ll_arg,
3964 &ll_bitsize, &ll_bitpos, &ll_mode,
3965 &ll_unsignedp, &volatilep, &ll_mask,
3967 lr_inner = decode_field_reference (lr_arg,
3968 &lr_bitsize, &lr_bitpos, &lr_mode,
3969 &lr_unsignedp, &volatilep, &lr_mask,
3971 rl_inner = decode_field_reference (rl_arg,
3972 &rl_bitsize, &rl_bitpos, &rl_mode,
3973 &rl_unsignedp, &volatilep, &rl_mask,
3975 rr_inner = decode_field_reference (rr_arg,
3976 &rr_bitsize, &rr_bitpos, &rr_mode,
3977 &rr_unsignedp, &volatilep, &rr_mask,
3980 /* It must be true that the inner operation on the lhs of each
3981 comparison must be the same if we are to be able to do anything.
3982 Then see if we have constants. If not, the same must be true for
3984 if (volatilep || ll_inner == 0 || rl_inner == 0
3985 || ! operand_equal_p (ll_inner, rl_inner, 0))
3988 if (TREE_CODE (lr_arg) == INTEGER_CST
3989 && TREE_CODE (rr_arg) == INTEGER_CST)
3990 l_const = lr_arg, r_const = rr_arg;
3991 else if (lr_inner == 0 || rr_inner == 0
3992 || ! operand_equal_p (lr_inner, rr_inner, 0))
3995 l_const = r_const = 0;
3997 /* If either comparison code is not correct for our logical operation,
3998 fail. However, we can convert a one-bit comparison against zero into
3999 the opposite comparison against that bit being set in the field. */
4001 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
4002 if (lcode != wanted_code)
4004 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
4006 /* Make the left operand unsigned, since we are only interested
4007 in the value of one bit. Otherwise we are doing the wrong
4016 /* This is analogous to the code for l_const above. */
4017 if (rcode != wanted_code)
4019 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
4028 /* See if we can find a mode that contains both fields being compared on
4029 the left. If we can't, fail. Otherwise, update all constants and masks
4030 to be relative to a field of that size. */
4031 first_bit = MIN (ll_bitpos, rl_bitpos);
4032 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
4033 lnmode = get_best_mode (end_bit - first_bit, first_bit,
4034 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
4036 if (lnmode == VOIDmode)
4039 lnbitsize = GET_MODE_BITSIZE (lnmode);
4040 lnbitpos = first_bit & ~ (lnbitsize - 1);
4041 lntype = type_for_size (lnbitsize, 1);
4042 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
4044 if (BYTES_BIG_ENDIAN)
4046 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
4047 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
4050 ll_mask = const_binop (LSHIFT_EXPR, convert (lntype, ll_mask),
4051 size_int (xll_bitpos), 0);
4052 rl_mask = const_binop (LSHIFT_EXPR, convert (lntype, rl_mask),
4053 size_int (xrl_bitpos), 0);
4057 l_const = convert (lntype, l_const);
4058 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
4059 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
4060 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
4061 fold (build1 (BIT_NOT_EXPR,
4065 warning ("comparison is always %d", wanted_code == NE_EXPR);
4067 return convert (truth_type,
4068 wanted_code == NE_EXPR
4069 ? integer_one_node : integer_zero_node);
4074 r_const = convert (lntype, r_const);
4075 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
4076 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
4077 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
4078 fold (build1 (BIT_NOT_EXPR,
4082 warning ("comparison is always %d", wanted_code == NE_EXPR);
4084 return convert (truth_type,
4085 wanted_code == NE_EXPR
4086 ? integer_one_node : integer_zero_node);
4090 /* If the right sides are not constant, do the same for it. Also,
4091 disallow this optimization if a size or signedness mismatch occurs
4092 between the left and right sides. */
4095 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
4096 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
4097 /* Make sure the two fields on the right
4098 correspond to the left without being swapped. */
4099 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
4102 first_bit = MIN (lr_bitpos, rr_bitpos);
4103 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
4104 rnmode = get_best_mode (end_bit - first_bit, first_bit,
4105 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
4107 if (rnmode == VOIDmode)
4110 rnbitsize = GET_MODE_BITSIZE (rnmode);
4111 rnbitpos = first_bit & ~ (rnbitsize - 1);
4112 rntype = type_for_size (rnbitsize, 1);
4113 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
4115 if (BYTES_BIG_ENDIAN)
4117 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
4118 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
4121 lr_mask = const_binop (LSHIFT_EXPR, convert (rntype, lr_mask),
4122 size_int (xlr_bitpos), 0);
4123 rr_mask = const_binop (LSHIFT_EXPR, convert (rntype, rr_mask),
4124 size_int (xrr_bitpos), 0);
4126 /* Make a mask that corresponds to both fields being compared.
4127 Do this for both items being compared. If the operands are the
4128 same size and the bits being compared are in the same position
4129 then we can do this by masking both and comparing the masked
4131 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4132 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
4133 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
4135 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4136 ll_unsignedp || rl_unsignedp);
4137 if (! all_ones_mask_p (ll_mask, lnbitsize))
4138 lhs = build (BIT_AND_EXPR, lntype, lhs, ll_mask);
4140 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
4141 lr_unsignedp || rr_unsignedp);
4142 if (! all_ones_mask_p (lr_mask, rnbitsize))
4143 rhs = build (BIT_AND_EXPR, rntype, rhs, lr_mask);
4145 return build (wanted_code, truth_type, lhs, rhs);
4148 /* There is still another way we can do something: If both pairs of
4149 fields being compared are adjacent, we may be able to make a wider
4150 field containing them both.
4152 Note that we still must mask the lhs/rhs expressions. Furthermore,
4153 the mask must be shifted to account for the shift done by
4154 make_bit_field_ref. */
4155 if ((ll_bitsize + ll_bitpos == rl_bitpos
4156 && lr_bitsize + lr_bitpos == rr_bitpos)
4157 || (ll_bitpos == rl_bitpos + rl_bitsize
4158 && lr_bitpos == rr_bitpos + rr_bitsize))
4162 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
4163 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
4164 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
4165 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
4167 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
4168 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
4169 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
4170 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
4172 /* Convert to the smaller type before masking out unwanted bits. */
4174 if (lntype != rntype)
4176 if (lnbitsize > rnbitsize)
4178 lhs = convert (rntype, lhs);
4179 ll_mask = convert (rntype, ll_mask);
4182 else if (lnbitsize < rnbitsize)
4184 rhs = convert (lntype, rhs);
4185 lr_mask = convert (lntype, lr_mask);
4190 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
4191 lhs = build (BIT_AND_EXPR, type, lhs, ll_mask);
4193 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
4194 rhs = build (BIT_AND_EXPR, type, rhs, lr_mask);
4196 return build (wanted_code, truth_type, lhs, rhs);
4202 /* Handle the case of comparisons with constants. If there is something in
4203 common between the masks, those bits of the constants must be the same.
4204 If not, the condition is always false. Test for this to avoid generating
4205 incorrect code below. */
4206 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
4207 if (! integer_zerop (result)
4208 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
4209 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
4211 if (wanted_code == NE_EXPR)
4213 warning ("`or' of unmatched not-equal tests is always 1");
4214 return convert (truth_type, integer_one_node);
4218 warning ("`and' of mutually exclusive equal-tests is always 0");
4219 return convert (truth_type, integer_zero_node);
4223 /* Construct the expression we will return. First get the component
4224 reference we will make. Unless the mask is all ones the width of
4225 that field, perform the mask operation. Then compare with the
4227 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4228 ll_unsignedp || rl_unsignedp);
4230 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4231 if (! all_ones_mask_p (ll_mask, lnbitsize))
4232 result = build (BIT_AND_EXPR, lntype, result, ll_mask);
4234 return build (wanted_code, truth_type, result,
4235 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
4238 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
4242 optimize_minmax_comparison (t)
4245 tree type = TREE_TYPE (t);
4246 tree arg0 = TREE_OPERAND (t, 0);
4247 enum tree_code op_code;
4248 tree comp_const = TREE_OPERAND (t, 1);
4250 int consts_equal, consts_lt;
4253 STRIP_SIGN_NOPS (arg0);
4255 op_code = TREE_CODE (arg0);
4256 minmax_const = TREE_OPERAND (arg0, 1);
4257 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
4258 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
4259 inner = TREE_OPERAND (arg0, 0);
4261 /* If something does not permit us to optimize, return the original tree. */
4262 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
4263 || TREE_CODE (comp_const) != INTEGER_CST
4264 || TREE_CONSTANT_OVERFLOW (comp_const)
4265 || TREE_CODE (minmax_const) != INTEGER_CST
4266 || TREE_CONSTANT_OVERFLOW (minmax_const))
4269 /* Now handle all the various comparison codes. We only handle EQ_EXPR
4270 and GT_EXPR, doing the rest with recursive calls using logical
4272 switch (TREE_CODE (t))
4274 case NE_EXPR: case LT_EXPR: case LE_EXPR:
4276 invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t)));
4280 fold (build (TRUTH_ORIF_EXPR, type,
4281 optimize_minmax_comparison
4282 (build (EQ_EXPR, type, arg0, comp_const)),
4283 optimize_minmax_comparison
4284 (build (GT_EXPR, type, arg0, comp_const))));
4287 if (op_code == MAX_EXPR && consts_equal)
4288 /* MAX (X, 0) == 0 -> X <= 0 */
4289 return fold (build (LE_EXPR, type, inner, comp_const));
4291 else if (op_code == MAX_EXPR && consts_lt)
4292 /* MAX (X, 0) == 5 -> X == 5 */
4293 return fold (build (EQ_EXPR, type, inner, comp_const));
4295 else if (op_code == MAX_EXPR)
4296 /* MAX (X, 0) == -1 -> false */
4297 return omit_one_operand (type, integer_zero_node, inner);
4299 else if (consts_equal)
4300 /* MIN (X, 0) == 0 -> X >= 0 */
4301 return fold (build (GE_EXPR, type, inner, comp_const));
4304 /* MIN (X, 0) == 5 -> false */
4305 return omit_one_operand (type, integer_zero_node, inner);
4308 /* MIN (X, 0) == -1 -> X == -1 */
4309 return fold (build (EQ_EXPR, type, inner, comp_const));
4312 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
4313 /* MAX (X, 0) > 0 -> X > 0
4314 MAX (X, 0) > 5 -> X > 5 */
4315 return fold (build (GT_EXPR, type, inner, comp_const));
4317 else if (op_code == MAX_EXPR)
4318 /* MAX (X, 0) > -1 -> true */
4319 return omit_one_operand (type, integer_one_node, inner);
4321 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
4322 /* MIN (X, 0) > 0 -> false
4323 MIN (X, 0) > 5 -> false */
4324 return omit_one_operand (type, integer_zero_node, inner);
4327 /* MIN (X, 0) > -1 -> X > -1 */
4328 return fold (build (GT_EXPR, type, inner, comp_const));
4335 /* T is an integer expression that is being multiplied, divided, or taken a
4336 modulus (CODE says which and what kind of divide or modulus) by a
4337 constant C. See if we can eliminate that operation by folding it with
4338 other operations already in T. WIDE_TYPE, if non-null, is a type that
4339 should be used for the computation if wider than our type.
4341 For example, if we are dividing (X * 8) + (Y + 16) by 4, we can return
4342 (X * 2) + (Y + 4). We must, however, be assured that either the original
4343 expression would not overflow or that overflow is undefined for the type
4344 in the language in question.
4346 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
4347 the machine has a multiply-accumulate insn or that this is part of an
4348 addressing calculation.
4350 If we return a non-null expression, it is an equivalent form of the
4351 original computation, but need not be in the original type. */
4354 extract_muldiv (t, c, code, wide_type)
4357 enum tree_code code;
4360 tree type = TREE_TYPE (t);
4361 enum tree_code tcode = TREE_CODE (t);
4362 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
4363 > GET_MODE_SIZE (TYPE_MODE (type)))
4364 ? wide_type : type);
4366 int same_p = tcode == code;
4367 tree op0 = NULL_TREE, op1 = NULL_TREE;
4369 /* Don't deal with constants of zero here; they confuse the code below. */
4370 if (integer_zerop (c))
4373 if (TREE_CODE_CLASS (tcode) == '1')
4374 op0 = TREE_OPERAND (t, 0);
4376 if (TREE_CODE_CLASS (tcode) == '2')
4377 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
4379 /* Note that we need not handle conditional operations here since fold
4380 already handles those cases. So just do arithmetic here. */
4384 /* For a constant, we can always simplify if we are a multiply
4385 or (for divide and modulus) if it is a multiple of our constant. */
4386 if (code == MULT_EXPR
4387 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
4388 return const_binop (code, convert (ctype, t), convert (ctype, c), 0);
4391 case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
4392 /* If op0 is an expression, and is unsigned, and the type is
4393 smaller than ctype, then we cannot widen the expression. */
4394 if ((TREE_CODE_CLASS (TREE_CODE (op0)) == '<'
4395 || TREE_CODE_CLASS (TREE_CODE (op0)) == '1'
4396 || TREE_CODE_CLASS (TREE_CODE (op0)) == '2'
4397 || TREE_CODE_CLASS (TREE_CODE (op0)) == 'e')
4398 && TREE_UNSIGNED (TREE_TYPE (op0))
4399 && ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
4400 && TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
4401 && (GET_MODE_SIZE (TYPE_MODE (ctype))
4402 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
4405 /* Pass the constant down and see if we can make a simplification. If
4406 we can, replace this expression with the inner simplification for
4407 possible later conversion to our or some other type. */
4408 if (0 != (t1 = extract_muldiv (op0, convert (TREE_TYPE (op0), c), code,
4409 code == MULT_EXPR ? ctype : NULL_TREE)))
4413 case NEGATE_EXPR: case ABS_EXPR:
4414 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4415 return fold (build1 (tcode, ctype, convert (ctype, t1)));
4418 case MIN_EXPR: case MAX_EXPR:
4419 /* If widening the type changes the signedness, then we can't perform
4420 this optimization as that changes the result. */
4421 if (TREE_UNSIGNED (ctype) != TREE_UNSIGNED (type))
4424 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
4425 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0
4426 && (t2 = extract_muldiv (op1, c, code, wide_type)) != 0)
4428 if (tree_int_cst_sgn (c) < 0)
4429 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
4431 return fold (build (tcode, ctype, convert (ctype, t1),
4432 convert (ctype, t2)));
4436 case WITH_RECORD_EXPR:
4437 if ((t1 = extract_muldiv (TREE_OPERAND (t, 0), c, code, wide_type)) != 0)
4438 return build (WITH_RECORD_EXPR, TREE_TYPE (t1), t1,
4439 TREE_OPERAND (t, 1));
4443 /* If this has not been evaluated and the operand has no side effects,
4444 we can see if we can do something inside it and make a new one.
4445 Note that this test is overly conservative since we can do this
4446 if the only reason it had side effects is that it was another
4447 similar SAVE_EXPR, but that isn't worth bothering with. */
4448 if (SAVE_EXPR_RTL (t) == 0 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0))
4449 && 0 != (t1 = extract_muldiv (TREE_OPERAND (t, 0), c, code,
4451 return save_expr (t1);
4454 case LSHIFT_EXPR: case RSHIFT_EXPR:
4455 /* If the second operand is constant, this is a multiplication
4456 or floor division, by a power of two, so we can treat it that
4457 way unless the multiplier or divisor overflows. */
4458 if (TREE_CODE (op1) == INTEGER_CST
4459 /* const_binop may not detect overflow correctly,
4460 so check for it explicitly here. */
4461 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
4462 && TREE_INT_CST_HIGH (op1) == 0
4463 && 0 != (t1 = convert (ctype,
4464 const_binop (LSHIFT_EXPR, size_one_node,
4466 && ! TREE_OVERFLOW (t1))
4467 return extract_muldiv (build (tcode == LSHIFT_EXPR
4468 ? MULT_EXPR : FLOOR_DIV_EXPR,
4469 ctype, convert (ctype, op0), t1),
4470 c, code, wide_type);
4473 case PLUS_EXPR: case MINUS_EXPR:
4474 /* See if we can eliminate the operation on both sides. If we can, we
4475 can return a new PLUS or MINUS. If we can't, the only remaining
4476 cases where we can do anything are if the second operand is a
4478 t1 = extract_muldiv (op0, c, code, wide_type);
4479 t2 = extract_muldiv (op1, c, code, wide_type);
4480 if (t1 != 0 && t2 != 0)
4481 return fold (build (tcode, ctype, convert (ctype, t1),
4482 convert (ctype, t2)));
4484 /* If this was a subtraction, negate OP1 and set it to be an addition.
4485 This simplifies the logic below. */
4486 if (tcode == MINUS_EXPR)
4487 tcode = PLUS_EXPR, op1 = negate_expr (op1);
4489 if (TREE_CODE (op1) != INTEGER_CST)
4492 /* If either OP1 or C are negative, this optimization is not safe for
4493 some of the division and remainder types while for others we need
4494 to change the code. */
4495 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
4497 if (code == CEIL_DIV_EXPR)
4498 code = FLOOR_DIV_EXPR;
4499 else if (code == CEIL_MOD_EXPR)
4500 code = FLOOR_MOD_EXPR;
4501 else if (code == FLOOR_DIV_EXPR)
4502 code = CEIL_DIV_EXPR;
4503 else if (code == FLOOR_MOD_EXPR)
4504 code = CEIL_MOD_EXPR;
4505 else if (code != MULT_EXPR)
4509 /* If it's a multiply or a division/modulus operation of a multiple
4510 of our constant, do the operation and verify it doesn't overflow. */
4511 if (code == MULT_EXPR
4512 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4514 op1 = const_binop (code, convert (ctype, op1), convert (ctype, c), 0);
4515 if (op1 == 0 || TREE_OVERFLOW (op1))
4521 /* If we have an unsigned type is not a sizetype, we cannot widen
4522 the operation since it will change the result if the original
4523 computation overflowed. */
4524 if (TREE_UNSIGNED (ctype)
4525 && ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
4529 /* If we were able to eliminate our operation from the first side,
4530 apply our operation to the second side and reform the PLUS. */
4531 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
4532 return fold (build (tcode, ctype, convert (ctype, t1), op1));
4534 /* The last case is if we are a multiply. In that case, we can
4535 apply the distributive law to commute the multiply and addition
4536 if the multiplication of the constants doesn't overflow. */
4537 if (code == MULT_EXPR)
4538 return fold (build (tcode, ctype, fold (build (code, ctype,
4539 convert (ctype, op0),
4540 convert (ctype, c))),
4546 /* We have a special case here if we are doing something like
4547 (C * 8) % 4 since we know that's zero. */
4548 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
4549 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
4550 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
4551 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4552 return omit_one_operand (type, integer_zero_node, op0);
4554 /* ... fall through ... */
4556 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
4557 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
4558 /* If we can extract our operation from the LHS, do so and return a
4559 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
4560 do something only if the second operand is a constant. */
4562 && (t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4563 return fold (build (tcode, ctype, convert (ctype, t1),
4564 convert (ctype, op1)));
4565 else if (tcode == MULT_EXPR && code == MULT_EXPR
4566 && (t1 = extract_muldiv (op1, c, code, wide_type)) != 0)
4567 return fold (build (tcode, ctype, convert (ctype, op0),
4568 convert (ctype, t1)));
4569 else if (TREE_CODE (op1) != INTEGER_CST)
4572 /* If these are the same operation types, we can associate them
4573 assuming no overflow. */
4575 && 0 != (t1 = const_binop (MULT_EXPR, convert (ctype, op1),
4576 convert (ctype, c), 0))
4577 && ! TREE_OVERFLOW (t1))
4578 return fold (build (tcode, ctype, convert (ctype, op0), t1));
4580 /* If these operations "cancel" each other, we have the main
4581 optimizations of this pass, which occur when either constant is a
4582 multiple of the other, in which case we replace this with either an
4583 operation or CODE or TCODE.
4585 If we have an unsigned type that is not a sizetype, we canot do
4586 this since it will change the result if the original computation
4588 if ((! TREE_UNSIGNED (ctype)
4589 || (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
4590 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
4591 || (tcode == MULT_EXPR
4592 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
4593 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR)))
4595 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4596 return fold (build (tcode, ctype, convert (ctype, op0),
4598 const_binop (TRUNC_DIV_EXPR,
4600 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
4601 return fold (build (code, ctype, convert (ctype, op0),
4603 const_binop (TRUNC_DIV_EXPR,
4615 /* If T contains a COMPOUND_EXPR which was inserted merely to evaluate
4616 S, a SAVE_EXPR, return the expression actually being evaluated. Note
4617 that we may sometimes modify the tree. */
4620 strip_compound_expr (t, s)
4624 enum tree_code code = TREE_CODE (t);
4626 /* See if this is the COMPOUND_EXPR we want to eliminate. */
4627 if (code == COMPOUND_EXPR && TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR
4628 && TREE_OPERAND (TREE_OPERAND (t, 0), 0) == s)
4629 return TREE_OPERAND (t, 1);
4631 /* See if this is a COND_EXPR or a simple arithmetic operator. We
4632 don't bother handling any other types. */
4633 else if (code == COND_EXPR)
4635 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4636 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4637 TREE_OPERAND (t, 2) = strip_compound_expr (TREE_OPERAND (t, 2), s);
4639 else if (TREE_CODE_CLASS (code) == '1')
4640 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4641 else if (TREE_CODE_CLASS (code) == '<'
4642 || TREE_CODE_CLASS (code) == '2')
4644 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4645 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4651 /* Return a node which has the indicated constant VALUE (either 0 or
4652 1), and is of the indicated TYPE. */
4655 constant_boolean_node (value, type)
4659 if (type == integer_type_node)
4660 return value ? integer_one_node : integer_zero_node;
4661 else if (TREE_CODE (type) == BOOLEAN_TYPE)
4662 return truthvalue_conversion (value ? integer_one_node :
4666 tree t = build_int_2 (value, 0);
4668 TREE_TYPE (t) = type;
4673 /* Utility function for the following routine, to see how complex a nesting of
4674 COND_EXPRs can be. EXPR is the expression and LIMIT is a count beyond which
4675 we don't care (to avoid spending too much time on complex expressions.). */
4678 count_cond (expr, lim)
4684 if (TREE_CODE (expr) != COND_EXPR)
4689 true = count_cond (TREE_OPERAND (expr, 1), lim - 1);
4690 false = count_cond (TREE_OPERAND (expr, 2), lim - 1 - true);
4691 return MIN (lim, 1 + true + false);
4694 /* Perform constant folding and related simplification of EXPR.
4695 The related simplifications include x*1 => x, x*0 => 0, etc.,
4696 and application of the associative law.
4697 NOP_EXPR conversions may be removed freely (as long as we
4698 are careful not to change the C type of the overall expression)
4699 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
4700 but we can constant-fold them if they have constant operands. */
4706 register tree t = expr;
4707 tree t1 = NULL_TREE;
4709 tree type = TREE_TYPE (expr);
4710 register tree arg0 = NULL_TREE, arg1 = NULL_TREE;
4711 register enum tree_code code = TREE_CODE (t);
4714 /* WINS will be nonzero when the switch is done
4715 if all operands are constant. */
4718 /* Don't try to process an RTL_EXPR since its operands aren't trees.
4719 Likewise for a SAVE_EXPR that's already been evaluated. */
4720 if (code == RTL_EXPR || (code == SAVE_EXPR && SAVE_EXPR_RTL (t)) != 0)
4723 /* Return right away if already constant. */
4724 if (TREE_CONSTANT (t))
4726 if (code == CONST_DECL)
4727 return DECL_INITIAL (t);
4731 #ifdef MAX_INTEGER_COMPUTATION_MODE
4732 check_max_integer_computation_mode (expr);
4735 kind = TREE_CODE_CLASS (code);
4736 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
4740 /* Special case for conversion ops that can have fixed point args. */
4741 arg0 = TREE_OPERAND (t, 0);
4743 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
4745 STRIP_SIGN_NOPS (arg0);
4747 if (arg0 != 0 && TREE_CODE (arg0) == COMPLEX_CST)
4748 subop = TREE_REALPART (arg0);
4752 if (subop != 0 && TREE_CODE (subop) != INTEGER_CST
4753 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
4754 && TREE_CODE (subop) != REAL_CST
4755 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
4757 /* Note that TREE_CONSTANT isn't enough:
4758 static var addresses are constant but we can't
4759 do arithmetic on them. */
4762 else if (IS_EXPR_CODE_CLASS (kind) || kind == 'r')
4764 register int len = TREE_CODE_LENGTH (code);
4766 for (i = 0; i < len; i++)
4768 tree op = TREE_OPERAND (t, i);
4772 continue; /* Valid for CALL_EXPR, at least. */
4774 if (kind == '<' || code == RSHIFT_EXPR)
4776 /* Signedness matters here. Perhaps we can refine this
4778 STRIP_SIGN_NOPS (op);
4781 /* Strip any conversions that don't change the mode. */
4784 if (TREE_CODE (op) == COMPLEX_CST)
4785 subop = TREE_REALPART (op);
4789 if (TREE_CODE (subop) != INTEGER_CST
4790 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
4791 && TREE_CODE (subop) != REAL_CST
4792 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
4794 /* Note that TREE_CONSTANT isn't enough:
4795 static var addresses are constant but we can't
4796 do arithmetic on them. */
4806 /* If this is a commutative operation, and ARG0 is a constant, move it
4807 to ARG1 to reduce the number of tests below. */
4808 if ((code == PLUS_EXPR || code == MULT_EXPR || code == MIN_EXPR
4809 || code == MAX_EXPR || code == BIT_IOR_EXPR || code == BIT_XOR_EXPR
4810 || code == BIT_AND_EXPR)
4811 && (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST))
4813 tem = arg0; arg0 = arg1; arg1 = tem;
4815 tem = TREE_OPERAND (t, 0); TREE_OPERAND (t, 0) = TREE_OPERAND (t, 1);
4816 TREE_OPERAND (t, 1) = tem;
4819 /* Now WINS is set as described above,
4820 ARG0 is the first operand of EXPR,
4821 and ARG1 is the second operand (if it has more than one operand).
4823 First check for cases where an arithmetic operation is applied to a
4824 compound, conditional, or comparison operation. Push the arithmetic
4825 operation inside the compound or conditional to see if any folding
4826 can then be done. Convert comparison to conditional for this purpose.
4827 The also optimizes non-constant cases that used to be done in
4830 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
4831 one of the operands is a comparison and the other is a comparison, a
4832 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
4833 code below would make the expression more complex. Change it to a
4834 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
4835 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
4837 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
4838 || code == EQ_EXPR || code == NE_EXPR)
4839 && ((truth_value_p (TREE_CODE (arg0))
4840 && (truth_value_p (TREE_CODE (arg1))
4841 || (TREE_CODE (arg1) == BIT_AND_EXPR
4842 && integer_onep (TREE_OPERAND (arg1, 1)))))
4843 || (truth_value_p (TREE_CODE (arg1))
4844 && (truth_value_p (TREE_CODE (arg0))
4845 || (TREE_CODE (arg0) == BIT_AND_EXPR
4846 && integer_onep (TREE_OPERAND (arg0, 1)))))))
4848 t = fold (build (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
4849 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
4853 if (code == EQ_EXPR)
4854 t = invert_truthvalue (t);
4859 if (TREE_CODE_CLASS (code) == '1')
4861 if (TREE_CODE (arg0) == COMPOUND_EXPR)
4862 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
4863 fold (build1 (code, type, TREE_OPERAND (arg0, 1))));
4864 else if (TREE_CODE (arg0) == COND_EXPR)
4866 t = fold (build (COND_EXPR, type, TREE_OPERAND (arg0, 0),
4867 fold (build1 (code, type, TREE_OPERAND (arg0, 1))),
4868 fold (build1 (code, type, TREE_OPERAND (arg0, 2)))));
4870 /* If this was a conversion, and all we did was to move into
4871 inside the COND_EXPR, bring it back out. But leave it if
4872 it is a conversion from integer to integer and the
4873 result precision is no wider than a word since such a
4874 conversion is cheap and may be optimized away by combine,
4875 while it couldn't if it were outside the COND_EXPR. Then return
4876 so we don't get into an infinite recursion loop taking the
4877 conversion out and then back in. */
4879 if ((code == NOP_EXPR || code == CONVERT_EXPR
4880 || code == NON_LVALUE_EXPR)
4881 && TREE_CODE (t) == COND_EXPR
4882 && TREE_CODE (TREE_OPERAND (t, 1)) == code
4883 && TREE_CODE (TREE_OPERAND (t, 2)) == code
4884 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))
4885 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 2), 0)))
4886 && ! (INTEGRAL_TYPE_P (TREE_TYPE (t))
4888 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))))
4889 && TYPE_PRECISION (TREE_TYPE (t)) <= BITS_PER_WORD))
4890 t = build1 (code, type,
4892 TREE_TYPE (TREE_OPERAND
4893 (TREE_OPERAND (t, 1), 0)),
4894 TREE_OPERAND (t, 0),
4895 TREE_OPERAND (TREE_OPERAND (t, 1), 0),
4896 TREE_OPERAND (TREE_OPERAND (t, 2), 0)));
4899 else if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<')
4900 return fold (build (COND_EXPR, type, arg0,
4901 fold (build1 (code, type, integer_one_node)),
4902 fold (build1 (code, type, integer_zero_node))));
4904 else if (TREE_CODE_CLASS (code) == '2'
4905 || TREE_CODE_CLASS (code) == '<')
4907 if (TREE_CODE (arg1) == COMPOUND_EXPR)
4908 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
4909 fold (build (code, type,
4910 arg0, TREE_OPERAND (arg1, 1))));
4911 else if ((TREE_CODE (arg1) == COND_EXPR
4912 || (TREE_CODE_CLASS (TREE_CODE (arg1)) == '<'
4913 && TREE_CODE_CLASS (code) != '<'))
4914 && (TREE_CODE (arg0) != COND_EXPR
4915 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
4916 && (! TREE_SIDE_EFFECTS (arg0)
4917 || (global_bindings_p () == 0
4918 && ! contains_placeholder_p (arg0))))
4920 tree test, true_value, false_value;
4921 tree lhs = 0, rhs = 0;
4923 if (TREE_CODE (arg1) == COND_EXPR)
4925 test = TREE_OPERAND (arg1, 0);
4926 true_value = TREE_OPERAND (arg1, 1);
4927 false_value = TREE_OPERAND (arg1, 2);
4931 tree testtype = TREE_TYPE (arg1);
4933 true_value = convert (testtype, integer_one_node);
4934 false_value = convert (testtype, integer_zero_node);
4937 /* If ARG0 is complex we want to make sure we only evaluate
4938 it once. Though this is only required if it is volatile, it
4939 might be more efficient even if it is not. However, if we
4940 succeed in folding one part to a constant, we do not need
4941 to make this SAVE_EXPR. Since we do this optimization
4942 primarily to see if we do end up with constant and this
4943 SAVE_EXPR interferes with later optimizations, suppressing
4944 it when we can is important.
4946 If we are not in a function, we can't make a SAVE_EXPR, so don't
4947 try to do so. Don't try to see if the result is a constant
4948 if an arm is a COND_EXPR since we get exponential behavior
4951 if (TREE_CODE (arg0) != SAVE_EXPR && ! TREE_CONSTANT (arg0)
4952 && global_bindings_p () == 0
4953 && ((TREE_CODE (arg0) != VAR_DECL
4954 && TREE_CODE (arg0) != PARM_DECL)
4955 || TREE_SIDE_EFFECTS (arg0)))
4957 if (TREE_CODE (true_value) != COND_EXPR)
4958 lhs = fold (build (code, type, arg0, true_value));
4960 if (TREE_CODE (false_value) != COND_EXPR)
4961 rhs = fold (build (code, type, arg0, false_value));
4963 if ((lhs == 0 || ! TREE_CONSTANT (lhs))
4964 && (rhs == 0 || !TREE_CONSTANT (rhs)))
4965 arg0 = save_expr (arg0), lhs = rhs = 0;
4969 lhs = fold (build (code, type, arg0, true_value));
4971 rhs = fold (build (code, type, arg0, false_value));
4973 test = fold (build (COND_EXPR, type, test, lhs, rhs));
4975 if (TREE_CODE (arg0) == SAVE_EXPR)
4976 return build (COMPOUND_EXPR, type,
4977 convert (void_type_node, arg0),
4978 strip_compound_expr (test, arg0));
4980 return convert (type, test);
4983 else if (TREE_CODE (arg0) == COMPOUND_EXPR)
4984 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
4985 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
4986 else if ((TREE_CODE (arg0) == COND_EXPR
4987 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
4988 && TREE_CODE_CLASS (code) != '<'))
4989 && (TREE_CODE (arg1) != COND_EXPR
4990 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
4991 && (! TREE_SIDE_EFFECTS (arg1)
4992 || (global_bindings_p () == 0
4993 && ! contains_placeholder_p (arg1))))
4995 tree test, true_value, false_value;
4996 tree lhs = 0, rhs = 0;
4998 if (TREE_CODE (arg0) == COND_EXPR)
5000 test = TREE_OPERAND (arg0, 0);
5001 true_value = TREE_OPERAND (arg0, 1);
5002 false_value = TREE_OPERAND (arg0, 2);
5006 tree testtype = TREE_TYPE (arg0);
5008 true_value = convert (testtype, integer_one_node);
5009 false_value = convert (testtype, integer_zero_node);
5012 if (TREE_CODE (arg1) != SAVE_EXPR && ! TREE_CONSTANT (arg0)
5013 && global_bindings_p () == 0
5014 && ((TREE_CODE (arg1) != VAR_DECL
5015 && TREE_CODE (arg1) != PARM_DECL)
5016 || TREE_SIDE_EFFECTS (arg1)))
5018 if (TREE_CODE (true_value) != COND_EXPR)
5019 lhs = fold (build (code, type, true_value, arg1));
5021 if (TREE_CODE (false_value) != COND_EXPR)
5022 rhs = fold (build (code, type, false_value, arg1));
5024 if ((lhs == 0 || ! TREE_CONSTANT (lhs))
5025 && (rhs == 0 || !TREE_CONSTANT (rhs)))
5026 arg1 = save_expr (arg1), lhs = rhs = 0;
5030 lhs = fold (build (code, type, true_value, arg1));
5033 rhs = fold (build (code, type, false_value, arg1));
5035 test = fold (build (COND_EXPR, type, test, lhs, rhs));
5036 if (TREE_CODE (arg1) == SAVE_EXPR)
5037 return build (COMPOUND_EXPR, type,
5038 convert (void_type_node, arg1),
5039 strip_compound_expr (test, arg1));
5041 return convert (type, test);
5044 else if (TREE_CODE_CLASS (code) == '<'
5045 && TREE_CODE (arg0) == COMPOUND_EXPR)
5046 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5047 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
5048 else if (TREE_CODE_CLASS (code) == '<'
5049 && TREE_CODE (arg1) == COMPOUND_EXPR)
5050 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
5051 fold (build (code, type, arg0, TREE_OPERAND (arg1, 1))));
5063 return fold (DECL_INITIAL (t));
5068 case FIX_TRUNC_EXPR:
5069 /* Other kinds of FIX are not handled properly by fold_convert. */
5071 if (TREE_TYPE (TREE_OPERAND (t, 0)) == TREE_TYPE (t))
5072 return TREE_OPERAND (t, 0);
5074 /* Handle cases of two conversions in a row. */
5075 if (TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
5076 || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR)
5078 tree inside_type = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5079 tree inter_type = TREE_TYPE (TREE_OPERAND (t, 0));
5080 tree final_type = TREE_TYPE (t);
5081 int inside_int = INTEGRAL_TYPE_P (inside_type);
5082 int inside_ptr = POINTER_TYPE_P (inside_type);
5083 int inside_float = FLOAT_TYPE_P (inside_type);
5084 unsigned int inside_prec = TYPE_PRECISION (inside_type);
5085 int inside_unsignedp = TREE_UNSIGNED (inside_type);
5086 int inter_int = INTEGRAL_TYPE_P (inter_type);
5087 int inter_ptr = POINTER_TYPE_P (inter_type);
5088 int inter_float = FLOAT_TYPE_P (inter_type);
5089 unsigned int inter_prec = TYPE_PRECISION (inter_type);
5090 int inter_unsignedp = TREE_UNSIGNED (inter_type);
5091 int final_int = INTEGRAL_TYPE_P (final_type);
5092 int final_ptr = POINTER_TYPE_P (final_type);
5093 int final_float = FLOAT_TYPE_P (final_type);
5094 unsigned int final_prec = TYPE_PRECISION (final_type);
5095 int final_unsignedp = TREE_UNSIGNED (final_type);
5097 /* In addition to the cases of two conversions in a row
5098 handled below, if we are converting something to its own
5099 type via an object of identical or wider precision, neither
5100 conversion is needed. */
5101 if (inside_type == final_type
5102 && ((inter_int && final_int) || (inter_float && final_float))
5103 && inter_prec >= final_prec)
5104 return TREE_OPERAND (TREE_OPERAND (t, 0), 0);
5106 /* Likewise, if the intermediate and final types are either both
5107 float or both integer, we don't need the middle conversion if
5108 it is wider than the final type and doesn't change the signedness
5109 (for integers). Avoid this if the final type is a pointer
5110 since then we sometimes need the inner conversion. Likewise if
5111 the outer has a precision not equal to the size of its mode. */
5112 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
5113 || (inter_float && inside_float))
5114 && inter_prec >= inside_prec
5115 && (inter_float || inter_unsignedp == inside_unsignedp)
5116 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
5117 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
5119 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5121 /* If we have a sign-extension of a zero-extended value, we can
5122 replace that by a single zero-extension. */
5123 if (inside_int && inter_int && final_int
5124 && inside_prec < inter_prec && inter_prec < final_prec
5125 && inside_unsignedp && !inter_unsignedp)
5126 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5128 /* Two conversions in a row are not needed unless:
5129 - some conversion is floating-point (overstrict for now), or
5130 - the intermediate type is narrower than both initial and
5132 - the intermediate type and innermost type differ in signedness,
5133 and the outermost type is wider than the intermediate, or
5134 - the initial type is a pointer type and the precisions of the
5135 intermediate and final types differ, or
5136 - the final type is a pointer type and the precisions of the
5137 initial and intermediate types differ. */
5138 if (! inside_float && ! inter_float && ! final_float
5139 && (inter_prec > inside_prec || inter_prec > final_prec)
5140 && ! (inside_int && inter_int
5141 && inter_unsignedp != inside_unsignedp
5142 && inter_prec < final_prec)
5143 && ((inter_unsignedp && inter_prec > inside_prec)
5144 == (final_unsignedp && final_prec > inter_prec))
5145 && ! (inside_ptr && inter_prec != final_prec)
5146 && ! (final_ptr && inside_prec != inter_prec)
5147 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
5148 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
5150 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5153 if (TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR
5154 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t, 0), 1))
5155 /* Detect assigning a bitfield. */
5156 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) == COMPONENT_REF
5157 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 1))))
5159 /* Don't leave an assignment inside a conversion
5160 unless assigning a bitfield. */
5161 tree prev = TREE_OPERAND (t, 0);
5162 TREE_OPERAND (t, 0) = TREE_OPERAND (prev, 1);
5163 /* First do the assignment, then return converted constant. */
5164 t = build (COMPOUND_EXPR, TREE_TYPE (t), prev, fold (t));
5170 TREE_CONSTANT (t) = TREE_CONSTANT (arg0);
5173 return fold_convert (t, arg0);
5175 #if 0 /* This loses on &"foo"[0]. */
5180 /* Fold an expression like: "foo"[2] */
5181 if (TREE_CODE (arg0) == STRING_CST
5182 && TREE_CODE (arg1) == INTEGER_CST
5183 && compare_tree_int (arg1, TREE_STRING_LENGTH (arg0)) < 0)
5185 t = build_int_2 (TREE_STRING_POINTER (arg0)[TREE_INT_CST_LOW (arg))], 0);
5186 TREE_TYPE (t) = TREE_TYPE (TREE_TYPE (arg0));
5187 force_fit_type (t, 0);
5194 if (TREE_CODE (arg0) == CONSTRUCTOR)
5196 tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0));
5203 TREE_CONSTANT (t) = wins;
5209 if (TREE_CODE (arg0) == INTEGER_CST)
5211 unsigned HOST_WIDE_INT low;
5213 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
5214 TREE_INT_CST_HIGH (arg0),
5216 t = build_int_2 (low, high);
5217 TREE_TYPE (t) = type;
5219 = (TREE_OVERFLOW (arg0)
5220 | force_fit_type (t, overflow && !TREE_UNSIGNED (type)));
5221 TREE_CONSTANT_OVERFLOW (t)
5222 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
5224 else if (TREE_CODE (arg0) == REAL_CST)
5225 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
5227 else if (TREE_CODE (arg0) == NEGATE_EXPR)
5228 return TREE_OPERAND (arg0, 0);
5230 /* Convert - (a - b) to (b - a) for non-floating-point. */
5231 else if (TREE_CODE (arg0) == MINUS_EXPR
5232 && (! FLOAT_TYPE_P (type) || flag_fast_math))
5233 return build (MINUS_EXPR, type, TREE_OPERAND (arg0, 1),
5234 TREE_OPERAND (arg0, 0));
5241 if (TREE_CODE (arg0) == INTEGER_CST)
5243 if (! TREE_UNSIGNED (type)
5244 && TREE_INT_CST_HIGH (arg0) < 0)
5246 unsigned HOST_WIDE_INT low;
5248 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
5249 TREE_INT_CST_HIGH (arg0),
5251 t = build_int_2 (low, high);
5252 TREE_TYPE (t) = type;
5254 = (TREE_OVERFLOW (arg0)
5255 | force_fit_type (t, overflow));
5256 TREE_CONSTANT_OVERFLOW (t)
5257 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
5260 else if (TREE_CODE (arg0) == REAL_CST)
5262 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
5263 t = build_real (type,
5264 REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
5267 else if (TREE_CODE (arg0) == ABS_EXPR || TREE_CODE (arg0) == NEGATE_EXPR)
5268 return build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0));
5272 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
5273 return convert (type, arg0);
5274 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
5275 return build (COMPLEX_EXPR, type,
5276 TREE_OPERAND (arg0, 0),
5277 negate_expr (TREE_OPERAND (arg0, 1)));
5278 else if (TREE_CODE (arg0) == COMPLEX_CST)
5279 return build_complex (type, TREE_OPERAND (arg0, 0),
5280 negate_expr (TREE_OPERAND (arg0, 1)));
5281 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
5282 return fold (build (TREE_CODE (arg0), type,
5283 fold (build1 (CONJ_EXPR, type,
5284 TREE_OPERAND (arg0, 0))),
5285 fold (build1 (CONJ_EXPR,
5286 type, TREE_OPERAND (arg0, 1)))));
5287 else if (TREE_CODE (arg0) == CONJ_EXPR)
5288 return TREE_OPERAND (arg0, 0);
5294 t = build_int_2 (~ TREE_INT_CST_LOW (arg0),
5295 ~ TREE_INT_CST_HIGH (arg0));
5296 TREE_TYPE (t) = type;
5297 force_fit_type (t, 0);
5298 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg0);
5299 TREE_CONSTANT_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (arg0);
5301 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
5302 return TREE_OPERAND (arg0, 0);
5306 /* A + (-B) -> A - B */
5307 if (TREE_CODE (arg1) == NEGATE_EXPR)
5308 return fold (build (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5309 /* (-A) + B -> B - A */
5310 if (TREE_CODE (arg0) == NEGATE_EXPR)
5311 return fold (build (MINUS_EXPR, type, arg1, TREE_OPERAND (arg0, 0)));
5312 else if (! FLOAT_TYPE_P (type))
5314 if (integer_zerop (arg1))
5315 return non_lvalue (convert (type, arg0));
5317 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
5318 with a constant, and the two constants have no bits in common,
5319 we should treat this as a BIT_IOR_EXPR since this may produce more
5321 if (TREE_CODE (arg0) == BIT_AND_EXPR
5322 && TREE_CODE (arg1) == BIT_AND_EXPR
5323 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5324 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
5325 && integer_zerop (const_binop (BIT_AND_EXPR,
5326 TREE_OPERAND (arg0, 1),
5327 TREE_OPERAND (arg1, 1), 0)))
5329 code = BIT_IOR_EXPR;
5333 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
5334 (plus (plus (mult) (mult)) (foo)) so that we can
5335 take advantage of the factoring cases below. */
5336 if ((TREE_CODE (arg0) == PLUS_EXPR
5337 && TREE_CODE (arg1) == MULT_EXPR)
5338 || (TREE_CODE (arg1) == PLUS_EXPR
5339 && TREE_CODE (arg0) == MULT_EXPR))
5341 tree parg0, parg1, parg, marg;
5343 if (TREE_CODE (arg0) == PLUS_EXPR)
5344 parg = arg0, marg = arg1;
5346 parg = arg1, marg = arg0;
5347 parg0 = TREE_OPERAND (parg, 0);
5348 parg1 = TREE_OPERAND (parg, 1);
5352 if (TREE_CODE (parg0) == MULT_EXPR
5353 && TREE_CODE (parg1) != MULT_EXPR)
5354 return fold (build (PLUS_EXPR, type,
5355 fold (build (PLUS_EXPR, type, parg0, marg)),
5357 if (TREE_CODE (parg0) != MULT_EXPR
5358 && TREE_CODE (parg1) == MULT_EXPR)
5359 return fold (build (PLUS_EXPR, type,
5360 fold (build (PLUS_EXPR, type, parg1, marg)),
5364 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR)
5366 tree arg00, arg01, arg10, arg11;
5367 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
5369 /* (A * C) + (B * C) -> (A+B) * C.
5370 We are most concerned about the case where C is a constant,
5371 but other combinations show up during loop reduction. Since
5372 it is not difficult, try all four possibilities. */
5374 arg00 = TREE_OPERAND (arg0, 0);
5375 arg01 = TREE_OPERAND (arg0, 1);
5376 arg10 = TREE_OPERAND (arg1, 0);
5377 arg11 = TREE_OPERAND (arg1, 1);
5380 if (operand_equal_p (arg01, arg11, 0))
5381 same = arg01, alt0 = arg00, alt1 = arg10;
5382 else if (operand_equal_p (arg00, arg10, 0))
5383 same = arg00, alt0 = arg01, alt1 = arg11;
5384 else if (operand_equal_p (arg00, arg11, 0))
5385 same = arg00, alt0 = arg01, alt1 = arg10;
5386 else if (operand_equal_p (arg01, arg10, 0))
5387 same = arg01, alt0 = arg00, alt1 = arg11;
5389 /* No identical multiplicands; see if we can find a common
5390 power-of-two factor in non-power-of-two multiplies. This
5391 can help in multi-dimensional array access. */
5392 else if (TREE_CODE (arg01) == INTEGER_CST
5393 && TREE_CODE (arg11) == INTEGER_CST
5394 && TREE_INT_CST_HIGH (arg01) == 0
5395 && TREE_INT_CST_HIGH (arg11) == 0)
5397 HOST_WIDE_INT int01, int11, tmp;
5398 int01 = TREE_INT_CST_LOW (arg01);
5399 int11 = TREE_INT_CST_LOW (arg11);
5401 /* Move min of absolute values to int11. */
5402 if ((int01 >= 0 ? int01 : -int01)
5403 < (int11 >= 0 ? int11 : -int11))
5405 tmp = int01, int01 = int11, int11 = tmp;
5406 alt0 = arg00, arg00 = arg10, arg10 = alt0;
5407 alt0 = arg01, arg01 = arg11, arg11 = alt0;
5410 if (exact_log2 (int11) > 0 && int01 % int11 == 0)
5412 alt0 = fold (build (MULT_EXPR, type, arg00,
5413 build_int_2 (int01 / int11, 0)));
5420 return fold (build (MULT_EXPR, type,
5421 fold (build (PLUS_EXPR, type, alt0, alt1)),
5425 /* In IEEE floating point, x+0 may not equal x. */
5426 else if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
5428 && real_zerop (arg1))
5429 return non_lvalue (convert (type, arg0));
5430 /* x+(-0) equals x, even for IEEE. */
5431 else if (TREE_CODE (arg1) == REAL_CST
5432 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (arg1)))
5433 return non_lvalue (convert (type, arg0));
5436 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
5437 is a rotate of A by C1 bits. */
5438 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
5439 is a rotate of A by B bits. */
5441 register enum tree_code code0, code1;
5442 code0 = TREE_CODE (arg0);
5443 code1 = TREE_CODE (arg1);
5444 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
5445 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
5446 && operand_equal_p (TREE_OPERAND (arg0, 0),
5447 TREE_OPERAND (arg1, 0), 0)
5448 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5450 register tree tree01, tree11;
5451 register enum tree_code code01, code11;
5453 tree01 = TREE_OPERAND (arg0, 1);
5454 tree11 = TREE_OPERAND (arg1, 1);
5455 STRIP_NOPS (tree01);
5456 STRIP_NOPS (tree11);
5457 code01 = TREE_CODE (tree01);
5458 code11 = TREE_CODE (tree11);
5459 if (code01 == INTEGER_CST
5460 && code11 == INTEGER_CST
5461 && TREE_INT_CST_HIGH (tree01) == 0
5462 && TREE_INT_CST_HIGH (tree11) == 0
5463 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
5464 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
5465 return build (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
5466 code0 == LSHIFT_EXPR ? tree01 : tree11);
5467 else if (code11 == MINUS_EXPR)
5469 tree tree110, tree111;
5470 tree110 = TREE_OPERAND (tree11, 0);
5471 tree111 = TREE_OPERAND (tree11, 1);
5472 STRIP_NOPS (tree110);
5473 STRIP_NOPS (tree111);
5474 if (TREE_CODE (tree110) == INTEGER_CST
5475 && 0 == compare_tree_int (tree110,
5477 (TREE_TYPE (TREE_OPERAND
5479 && operand_equal_p (tree01, tree111, 0))
5480 return build ((code0 == LSHIFT_EXPR
5483 type, TREE_OPERAND (arg0, 0), tree01);
5485 else if (code01 == MINUS_EXPR)
5487 tree tree010, tree011;
5488 tree010 = TREE_OPERAND (tree01, 0);
5489 tree011 = TREE_OPERAND (tree01, 1);
5490 STRIP_NOPS (tree010);
5491 STRIP_NOPS (tree011);
5492 if (TREE_CODE (tree010) == INTEGER_CST
5493 && 0 == compare_tree_int (tree010,
5495 (TREE_TYPE (TREE_OPERAND
5497 && operand_equal_p (tree11, tree011, 0))
5498 return build ((code0 != LSHIFT_EXPR
5501 type, TREE_OPERAND (arg0, 0), tree11);
5507 /* In most languages, can't associate operations on floats through
5508 parentheses. Rather than remember where the parentheses were, we
5509 don't associate floats at all. It shouldn't matter much. However,
5510 associating multiplications is only very slightly inaccurate, so do
5511 that if -ffast-math is specified. */
5514 && (! FLOAT_TYPE_P (type)
5515 || (flag_fast_math && code != MULT_EXPR)))
5517 tree var0, con0, lit0, var1, con1, lit1;
5519 /* Split both trees into variables, constants, and literals. Then
5520 associate each group together, the constants with literals,
5521 then the result with variables. This increases the chances of
5522 literals being recombined later and of generating relocatable
5523 expressions for the sum of a constant and literal. */
5524 var0 = split_tree (arg0, code, &con0, &lit0, 0);
5525 var1 = split_tree (arg1, code, &con1, &lit1, code == MINUS_EXPR);
5527 /* Only do something if we found more than two objects. Otherwise,
5528 nothing has changed and we risk infinite recursion. */
5529 if (2 < ((var0 != 0) + (var1 != 0) + (con0 != 0) + (con1 != 0)
5530 + (lit0 != 0) + (lit1 != 0)))
5532 var0 = associate_trees (var0, var1, code, type);
5533 con0 = associate_trees (con0, con1, code, type);
5534 lit0 = associate_trees (lit0, lit1, code, type);
5535 con0 = associate_trees (con0, lit0, code, type);
5536 return convert (type, associate_trees (var0, con0, code, type));
5541 #if defined (REAL_IS_NOT_DOUBLE) && ! defined (REAL_ARITHMETIC)
5542 if (TREE_CODE (arg1) == REAL_CST)
5544 #endif /* REAL_IS_NOT_DOUBLE, and no REAL_ARITHMETIC */
5546 t1 = const_binop (code, arg0, arg1, 0);
5547 if (t1 != NULL_TREE)
5549 /* The return value should always have
5550 the same type as the original expression. */
5551 if (TREE_TYPE (t1) != TREE_TYPE (t))
5552 t1 = convert (TREE_TYPE (t), t1);
5559 /* A - (-B) -> A + B */
5560 if (TREE_CODE (arg1) == NEGATE_EXPR)
5561 return fold (build (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5562 /* (-A) - CST -> (-CST) - A for floating point (what about ints ?) */
5563 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == REAL_CST)
5565 fold (build (MINUS_EXPR, type,
5566 build_real (TREE_TYPE (arg1),
5567 REAL_VALUE_NEGATE (TREE_REAL_CST (arg1))),
5568 TREE_OPERAND (arg0, 0)));
5570 if (! FLOAT_TYPE_P (type))
5572 if (! wins && integer_zerop (arg0))
5573 return negate_expr (convert (type, arg1));
5574 if (integer_zerop (arg1))
5575 return non_lvalue (convert (type, arg0));
5577 /* (A * C) - (B * C) -> (A-B) * C. Since we are most concerned
5578 about the case where C is a constant, just try one of the
5579 four possibilities. */
5581 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR
5582 && operand_equal_p (TREE_OPERAND (arg0, 1),
5583 TREE_OPERAND (arg1, 1), 0))
5584 return fold (build (MULT_EXPR, type,
5585 fold (build (MINUS_EXPR, type,
5586 TREE_OPERAND (arg0, 0),
5587 TREE_OPERAND (arg1, 0))),
5588 TREE_OPERAND (arg0, 1)));
5591 else if (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
5594 /* Except with IEEE floating point, 0-x equals -x. */
5595 if (! wins && real_zerop (arg0))
5596 return negate_expr (convert (type, arg1));
5597 /* Except with IEEE floating point, x-0 equals x. */
5598 if (real_zerop (arg1))
5599 return non_lvalue (convert (type, arg0));
5602 /* Fold &x - &x. This can happen from &x.foo - &x.
5603 This is unsafe for certain floats even in non-IEEE formats.
5604 In IEEE, it is unsafe because it does wrong for NaNs.
5605 Also note that operand_equal_p is always false if an operand
5608 if ((! FLOAT_TYPE_P (type) || flag_fast_math)
5609 && operand_equal_p (arg0, arg1, 0))
5610 return convert (type, integer_zero_node);
5615 /* (-A) * (-B) -> A * B */
5616 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR)
5617 return fold (build (MULT_EXPR, type, TREE_OPERAND (arg0, 0),
5618 TREE_OPERAND (arg1, 0)));
5620 if (! FLOAT_TYPE_P (type))
5622 if (integer_zerop (arg1))
5623 return omit_one_operand (type, arg1, arg0);
5624 if (integer_onep (arg1))
5625 return non_lvalue (convert (type, arg0));
5627 /* (a * (1 << b)) is (a << b) */
5628 if (TREE_CODE (arg1) == LSHIFT_EXPR
5629 && integer_onep (TREE_OPERAND (arg1, 0)))
5630 return fold (build (LSHIFT_EXPR, type, arg0,
5631 TREE_OPERAND (arg1, 1)));
5632 if (TREE_CODE (arg0) == LSHIFT_EXPR
5633 && integer_onep (TREE_OPERAND (arg0, 0)))
5634 return fold (build (LSHIFT_EXPR, type, arg1,
5635 TREE_OPERAND (arg0, 1)));
5637 if (TREE_CODE (arg1) == INTEGER_CST
5638 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
5640 return convert (type, tem);
5645 /* x*0 is 0, except for IEEE floating point. */
5646 if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
5648 && real_zerop (arg1))
5649 return omit_one_operand (type, arg1, arg0);
5650 /* In IEEE floating point, x*1 is not equivalent to x for snans.
5651 However, ANSI says we can drop signals,
5652 so we can do this anyway. */
5653 if (real_onep (arg1))
5654 return non_lvalue (convert (type, arg0));
5656 if (! wins && real_twop (arg1) && global_bindings_p () == 0
5657 && ! contains_placeholder_p (arg0))
5659 tree arg = save_expr (arg0);
5660 return build (PLUS_EXPR, type, arg, arg);
5667 if (integer_all_onesp (arg1))
5668 return omit_one_operand (type, arg1, arg0);
5669 if (integer_zerop (arg1))
5670 return non_lvalue (convert (type, arg0));
5671 t1 = distribute_bit_expr (code, type, arg0, arg1);
5672 if (t1 != NULL_TREE)
5675 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
5677 This results in more efficient code for machines without a NAND
5678 instruction. Combine will canonicalize to the first form
5679 which will allow use of NAND instructions provided by the
5680 backend if they exist. */
5681 if (TREE_CODE (arg0) == BIT_NOT_EXPR
5682 && TREE_CODE (arg1) == BIT_NOT_EXPR)
5684 return fold (build1 (BIT_NOT_EXPR, type,
5685 build (BIT_AND_EXPR, type,
5686 TREE_OPERAND (arg0, 0),
5687 TREE_OPERAND (arg1, 0))));
5690 /* See if this can be simplified into a rotate first. If that
5691 is unsuccessful continue in the association code. */
5695 if (integer_zerop (arg1))
5696 return non_lvalue (convert (type, arg0));
5697 if (integer_all_onesp (arg1))
5698 return fold (build1 (BIT_NOT_EXPR, type, arg0));
5700 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
5701 with a constant, and the two constants have no bits in common,
5702 we should treat this as a BIT_IOR_EXPR since this may produce more
5704 if (TREE_CODE (arg0) == BIT_AND_EXPR
5705 && TREE_CODE (arg1) == BIT_AND_EXPR
5706 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5707 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
5708 && integer_zerop (const_binop (BIT_AND_EXPR,
5709 TREE_OPERAND (arg0, 1),
5710 TREE_OPERAND (arg1, 1), 0)))
5712 code = BIT_IOR_EXPR;
5716 /* See if this can be simplified into a rotate first. If that
5717 is unsuccessful continue in the association code. */
5722 if (integer_all_onesp (arg1))
5723 return non_lvalue (convert (type, arg0));
5724 if (integer_zerop (arg1))
5725 return omit_one_operand (type, arg1, arg0);
5726 t1 = distribute_bit_expr (code, type, arg0, arg1);
5727 if (t1 != NULL_TREE)
5729 /* Simplify ((int)c & 0x377) into (int)c, if c is unsigned char. */
5730 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == NOP_EXPR
5731 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg1, 0))))
5734 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg1, 0)));
5736 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
5737 && (~TREE_INT_CST_LOW (arg0)
5738 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
5739 return build1 (NOP_EXPR, type, TREE_OPERAND (arg1, 0));
5741 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
5742 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5745 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
5747 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
5748 && (~TREE_INT_CST_LOW (arg1)
5749 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
5750 return build1 (NOP_EXPR, type, TREE_OPERAND (arg0, 0));
5753 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
5755 This results in more efficient code for machines without a NOR
5756 instruction. Combine will canonicalize to the first form
5757 which will allow use of NOR instructions provided by the
5758 backend if they exist. */
5759 if (TREE_CODE (arg0) == BIT_NOT_EXPR
5760 && TREE_CODE (arg1) == BIT_NOT_EXPR)
5762 return fold (build1 (BIT_NOT_EXPR, type,
5763 build (BIT_IOR_EXPR, type,
5764 TREE_OPERAND (arg0, 0),
5765 TREE_OPERAND (arg1, 0))));
5770 case BIT_ANDTC_EXPR:
5771 if (integer_all_onesp (arg0))
5772 return non_lvalue (convert (type, arg1));
5773 if (integer_zerop (arg0))
5774 return omit_one_operand (type, arg0, arg1);
5775 if (TREE_CODE (arg1) == INTEGER_CST)
5777 arg1 = fold (build1 (BIT_NOT_EXPR, type, arg1));
5778 code = BIT_AND_EXPR;
5784 /* In most cases, do nothing with a divide by zero. */
5785 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
5786 #ifndef REAL_INFINITY
5787 if (TREE_CODE (arg1) == REAL_CST && real_zerop (arg1))
5790 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
5792 /* (-A) / (-B) -> A / B */
5793 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR)
5794 return fold (build (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
5795 TREE_OPERAND (arg1, 0)));
5797 /* In IEEE floating point, x/1 is not equivalent to x for snans.
5798 However, ANSI says we can drop signals, so we can do this anyway. */
5799 if (real_onep (arg1))
5800 return non_lvalue (convert (type, arg0));
5802 /* If ARG1 is a constant, we can convert this to a multiply by the
5803 reciprocal. This does not have the same rounding properties,
5804 so only do this if -ffast-math. We can actually always safely
5805 do it if ARG1 is a power of two, but it's hard to tell if it is
5806 or not in a portable manner. */
5807 if (TREE_CODE (arg1) == REAL_CST)
5810 && 0 != (tem = const_binop (code, build_real (type, dconst1),
5812 return fold (build (MULT_EXPR, type, arg0, tem));
5813 /* Find the reciprocal if optimizing and the result is exact. */
5817 r = TREE_REAL_CST (arg1);
5818 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
5820 tem = build_real (type, r);
5821 return fold (build (MULT_EXPR, type, arg0, tem));
5827 case TRUNC_DIV_EXPR:
5828 case ROUND_DIV_EXPR:
5829 case FLOOR_DIV_EXPR:
5831 case EXACT_DIV_EXPR:
5832 if (integer_onep (arg1))
5833 return non_lvalue (convert (type, arg0));
5834 if (integer_zerop (arg1))
5837 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
5838 operation, EXACT_DIV_EXPR.
5840 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
5841 At one time others generated faster code, it's not clear if they do
5842 after the last round to changes to the DIV code in expmed.c. */
5843 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
5844 && multiple_of_p (type, arg0, arg1))
5845 return fold (build (EXACT_DIV_EXPR, type, arg0, arg1));
5847 if (TREE_CODE (arg1) == INTEGER_CST
5848 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
5850 return convert (type, tem);
5855 case FLOOR_MOD_EXPR:
5856 case ROUND_MOD_EXPR:
5857 case TRUNC_MOD_EXPR:
5858 if (integer_onep (arg1))
5859 return omit_one_operand (type, integer_zero_node, arg0);
5860 if (integer_zerop (arg1))
5863 if (TREE_CODE (arg1) == INTEGER_CST
5864 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
5866 return convert (type, tem);
5874 if (integer_zerop (arg1))
5875 return non_lvalue (convert (type, arg0));
5876 /* Since negative shift count is not well-defined,
5877 don't try to compute it in the compiler. */
5878 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
5880 /* Rewrite an LROTATE_EXPR by a constant into an
5881 RROTATE_EXPR by a new constant. */
5882 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
5884 TREE_SET_CODE (t, RROTATE_EXPR);
5885 code = RROTATE_EXPR;
5886 TREE_OPERAND (t, 1) = arg1
5889 convert (TREE_TYPE (arg1),
5890 build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type)), 0)),
5892 if (tree_int_cst_sgn (arg1) < 0)
5896 /* If we have a rotate of a bit operation with the rotate count and
5897 the second operand of the bit operation both constant,
5898 permute the two operations. */
5899 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
5900 && (TREE_CODE (arg0) == BIT_AND_EXPR
5901 || TREE_CODE (arg0) == BIT_ANDTC_EXPR
5902 || TREE_CODE (arg0) == BIT_IOR_EXPR
5903 || TREE_CODE (arg0) == BIT_XOR_EXPR)
5904 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
5905 return fold (build (TREE_CODE (arg0), type,
5906 fold (build (code, type,
5907 TREE_OPERAND (arg0, 0), arg1)),
5908 fold (build (code, type,
5909 TREE_OPERAND (arg0, 1), arg1))));
5911 /* Two consecutive rotates adding up to the width of the mode can
5913 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
5914 && TREE_CODE (arg0) == RROTATE_EXPR
5915 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5916 && TREE_INT_CST_HIGH (arg1) == 0
5917 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
5918 && ((TREE_INT_CST_LOW (arg1)
5919 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
5920 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type))))
5921 return TREE_OPERAND (arg0, 0);
5926 if (operand_equal_p (arg0, arg1, 0))
5927 return omit_one_operand (type, arg0, arg1);
5928 if (INTEGRAL_TYPE_P (type)
5929 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), 1))
5930 return omit_one_operand (type, arg1, arg0);
5934 if (operand_equal_p (arg0, arg1, 0))
5935 return omit_one_operand (type, arg0, arg1);
5936 if (INTEGRAL_TYPE_P (type)
5937 && TYPE_MAX_VALUE (type)
5938 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), 1))
5939 return omit_one_operand (type, arg1, arg0);
5942 case TRUTH_NOT_EXPR:
5943 /* Note that the operand of this must be an int
5944 and its values must be 0 or 1.
5945 ("true" is a fixed value perhaps depending on the language,
5946 but we don't handle values other than 1 correctly yet.) */
5947 tem = invert_truthvalue (arg0);
5948 /* Avoid infinite recursion. */
5949 if (TREE_CODE (tem) == TRUTH_NOT_EXPR)
5951 return convert (type, tem);
5953 case TRUTH_ANDIF_EXPR:
5954 /* Note that the operands of this must be ints
5955 and their values must be 0 or 1.
5956 ("true" is a fixed value perhaps depending on the language.) */
5957 /* If first arg is constant zero, return it. */
5958 if (integer_zerop (arg0))
5959 return convert (type, arg0);
5960 case TRUTH_AND_EXPR:
5961 /* If either arg is constant true, drop it. */
5962 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
5963 return non_lvalue (convert (type, arg1));
5964 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
5965 return non_lvalue (convert (type, arg0));
5966 /* If second arg is constant zero, result is zero, but first arg
5967 must be evaluated. */
5968 if (integer_zerop (arg1))
5969 return omit_one_operand (type, arg1, arg0);
5970 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
5971 case will be handled here. */
5972 if (integer_zerop (arg0))
5973 return omit_one_operand (type, arg0, arg1);
5976 /* We only do these simplifications if we are optimizing. */
5980 /* Check for things like (A || B) && (A || C). We can convert this
5981 to A || (B && C). Note that either operator can be any of the four
5982 truth and/or operations and the transformation will still be
5983 valid. Also note that we only care about order for the
5984 ANDIF and ORIF operators. If B contains side effects, this
5985 might change the truth-value of A. */
5986 if (TREE_CODE (arg0) == TREE_CODE (arg1)
5987 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
5988 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
5989 || TREE_CODE (arg0) == TRUTH_AND_EXPR
5990 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
5991 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
5993 tree a00 = TREE_OPERAND (arg0, 0);
5994 tree a01 = TREE_OPERAND (arg0, 1);
5995 tree a10 = TREE_OPERAND (arg1, 0);
5996 tree a11 = TREE_OPERAND (arg1, 1);
5997 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
5998 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
5999 && (code == TRUTH_AND_EXPR
6000 || code == TRUTH_OR_EXPR));
6002 if (operand_equal_p (a00, a10, 0))
6003 return fold (build (TREE_CODE (arg0), type, a00,
6004 fold (build (code, type, a01, a11))));
6005 else if (commutative && operand_equal_p (a00, a11, 0))
6006 return fold (build (TREE_CODE (arg0), type, a00,
6007 fold (build (code, type, a01, a10))));
6008 else if (commutative && operand_equal_p (a01, a10, 0))
6009 return fold (build (TREE_CODE (arg0), type, a01,
6010 fold (build (code, type, a00, a11))));
6012 /* This case if tricky because we must either have commutative
6013 operators or else A10 must not have side-effects. */
6015 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
6016 && operand_equal_p (a01, a11, 0))
6017 return fold (build (TREE_CODE (arg0), type,
6018 fold (build (code, type, a00, a10)),
6022 /* See if we can build a range comparison. */
6023 if (0 != (tem = fold_range_test (t)))
6026 /* Check for the possibility of merging component references. If our
6027 lhs is another similar operation, try to merge its rhs with our
6028 rhs. Then try to merge our lhs and rhs. */
6029 if (TREE_CODE (arg0) == code
6030 && 0 != (tem = fold_truthop (code, type,
6031 TREE_OPERAND (arg0, 1), arg1)))
6032 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6034 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
6039 case TRUTH_ORIF_EXPR:
6040 /* Note that the operands of this must be ints
6041 and their values must be 0 or true.
6042 ("true" is a fixed value perhaps depending on the language.) */
6043 /* If first arg is constant true, return it. */
6044 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
6045 return convert (type, arg0);
6047 /* If either arg is constant zero, drop it. */
6048 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
6049 return non_lvalue (convert (type, arg1));
6050 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1))
6051 return non_lvalue (convert (type, arg0));
6052 /* If second arg is constant true, result is true, but we must
6053 evaluate first arg. */
6054 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
6055 return omit_one_operand (type, arg1, arg0);
6056 /* Likewise for first arg, but note this only occurs here for
6058 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
6059 return omit_one_operand (type, arg0, arg1);
6062 case TRUTH_XOR_EXPR:
6063 /* If either arg is constant zero, drop it. */
6064 if (integer_zerop (arg0))
6065 return non_lvalue (convert (type, arg1));
6066 if (integer_zerop (arg1))
6067 return non_lvalue (convert (type, arg0));
6068 /* If either arg is constant true, this is a logical inversion. */
6069 if (integer_onep (arg0))
6070 return non_lvalue (convert (type, invert_truthvalue (arg1)));
6071 if (integer_onep (arg1))
6072 return non_lvalue (convert (type, invert_truthvalue (arg0)));
6081 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
6083 /* (-a) CMP (-b) -> b CMP a */
6084 if (TREE_CODE (arg0) == NEGATE_EXPR
6085 && TREE_CODE (arg1) == NEGATE_EXPR)
6086 return fold (build (code, type, TREE_OPERAND (arg1, 0),
6087 TREE_OPERAND (arg0, 0)));
6088 /* (-a) CMP CST -> a swap(CMP) (-CST) */
6089 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == REAL_CST)
6092 (swap_tree_comparison (code), type,
6093 TREE_OPERAND (arg0, 0),
6094 build_real (TREE_TYPE (arg1),
6095 REAL_VALUE_NEGATE (TREE_REAL_CST (arg1)))));
6096 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
6097 /* a CMP (-0) -> a CMP 0 */
6098 if (TREE_CODE (arg1) == REAL_CST
6099 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (arg1)))
6100 return fold (build (code, type, arg0,
6101 build_real (TREE_TYPE (arg1), dconst0)));
6104 /* If one arg is a constant integer, put it last. */
6105 if (TREE_CODE (arg0) == INTEGER_CST
6106 && TREE_CODE (arg1) != INTEGER_CST)
6108 TREE_OPERAND (t, 0) = arg1;
6109 TREE_OPERAND (t, 1) = arg0;
6110 arg0 = TREE_OPERAND (t, 0);
6111 arg1 = TREE_OPERAND (t, 1);
6112 code = swap_tree_comparison (code);
6113 TREE_SET_CODE (t, code);
6116 /* Convert foo++ == CONST into ++foo == CONST + INCR.
6117 First, see if one arg is constant; find the constant arg
6118 and the other one. */
6120 tree constop = 0, varop = NULL_TREE;
6121 int constopnum = -1;
6123 if (TREE_CONSTANT (arg1))
6124 constopnum = 1, constop = arg1, varop = arg0;
6125 if (TREE_CONSTANT (arg0))
6126 constopnum = 0, constop = arg0, varop = arg1;
6128 if (constop && TREE_CODE (varop) == POSTINCREMENT_EXPR)
6130 /* This optimization is invalid for ordered comparisons
6131 if CONST+INCR overflows or if foo+incr might overflow.
6132 This optimization is invalid for floating point due to rounding.
6133 For pointer types we assume overflow doesn't happen. */
6134 if (POINTER_TYPE_P (TREE_TYPE (varop))
6135 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
6136 && (code == EQ_EXPR || code == NE_EXPR)))
6139 = fold (build (PLUS_EXPR, TREE_TYPE (varop),
6140 constop, TREE_OPERAND (varop, 1)));
6142 /* Do not overwrite the current varop to be a preincrement,
6143 create a new node so that we won't confuse our caller who
6144 might create trees and throw them away, reusing the
6145 arguments that they passed to build. This shows up in
6146 the THEN or ELSE parts of ?: being postincrements. */
6147 varop = build (PREINCREMENT_EXPR, TREE_TYPE (varop),
6148 TREE_OPERAND (varop, 0),
6149 TREE_OPERAND (varop, 1));
6151 /* If VAROP is a reference to a bitfield, we must mask
6152 the constant by the width of the field. */
6153 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
6154 && DECL_BIT_FIELD(TREE_OPERAND
6155 (TREE_OPERAND (varop, 0), 1)))
6158 = TREE_INT_CST_LOW (DECL_SIZE
6160 (TREE_OPERAND (varop, 0), 1)));
6161 tree mask, unsigned_type;
6162 unsigned int precision;
6163 tree folded_compare;
6165 /* First check whether the comparison would come out
6166 always the same. If we don't do that we would
6167 change the meaning with the masking. */
6168 if (constopnum == 0)
6169 folded_compare = fold (build (code, type, constop,
6170 TREE_OPERAND (varop, 0)));
6172 folded_compare = fold (build (code, type,
6173 TREE_OPERAND (varop, 0),
6175 if (integer_zerop (folded_compare)
6176 || integer_onep (folded_compare))
6177 return omit_one_operand (type, folded_compare, varop);
6179 unsigned_type = type_for_size (size, 1);
6180 precision = TYPE_PRECISION (unsigned_type);
6181 mask = build_int_2 (~0, ~0);
6182 TREE_TYPE (mask) = unsigned_type;
6183 force_fit_type (mask, 0);
6184 mask = const_binop (RSHIFT_EXPR, mask,
6185 size_int (precision - size), 0);
6186 newconst = fold (build (BIT_AND_EXPR,
6187 TREE_TYPE (varop), newconst,
6188 convert (TREE_TYPE (varop),
6192 t = build (code, type,
6193 (constopnum == 0) ? newconst : varop,
6194 (constopnum == 1) ? newconst : varop);
6198 else if (constop && TREE_CODE (varop) == POSTDECREMENT_EXPR)
6200 if (POINTER_TYPE_P (TREE_TYPE (varop))
6201 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
6202 && (code == EQ_EXPR || code == NE_EXPR)))
6205 = fold (build (MINUS_EXPR, TREE_TYPE (varop),
6206 constop, TREE_OPERAND (varop, 1)));
6208 /* Do not overwrite the current varop to be a predecrement,
6209 create a new node so that we won't confuse our caller who
6210 might create trees and throw them away, reusing the
6211 arguments that they passed to build. This shows up in
6212 the THEN or ELSE parts of ?: being postdecrements. */
6213 varop = build (PREDECREMENT_EXPR, TREE_TYPE (varop),
6214 TREE_OPERAND (varop, 0),
6215 TREE_OPERAND (varop, 1));
6217 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
6218 && DECL_BIT_FIELD(TREE_OPERAND
6219 (TREE_OPERAND (varop, 0), 1)))
6222 = TREE_INT_CST_LOW (DECL_SIZE
6224 (TREE_OPERAND (varop, 0), 1)));
6225 tree mask, unsigned_type;
6226 unsigned int precision;
6227 tree folded_compare;
6229 if (constopnum == 0)
6230 folded_compare = fold (build (code, type, constop,
6231 TREE_OPERAND (varop, 0)));
6233 folded_compare = fold (build (code, type,
6234 TREE_OPERAND (varop, 0),
6236 if (integer_zerop (folded_compare)
6237 || integer_onep (folded_compare))
6238 return omit_one_operand (type, folded_compare, varop);
6240 unsigned_type = type_for_size (size, 1);
6241 precision = TYPE_PRECISION (unsigned_type);
6242 mask = build_int_2 (~0, ~0);
6243 TREE_TYPE (mask) = TREE_TYPE (varop);
6244 force_fit_type (mask, 0);
6245 mask = const_binop (RSHIFT_EXPR, mask,
6246 size_int (precision - size), 0);
6247 newconst = fold (build (BIT_AND_EXPR,
6248 TREE_TYPE (varop), newconst,
6249 convert (TREE_TYPE (varop),
6253 t = build (code, type,
6254 (constopnum == 0) ? newconst : varop,
6255 (constopnum == 1) ? newconst : varop);
6261 /* Change X >= CST to X > (CST - 1) if CST is positive. */
6262 if (TREE_CODE (arg1) == INTEGER_CST
6263 && TREE_CODE (arg0) != INTEGER_CST
6264 && tree_int_cst_sgn (arg1) > 0)
6266 switch (TREE_CODE (t))
6270 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6271 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6276 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6277 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6285 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
6286 a MINUS_EXPR of a constant, we can convert it into a comparison with
6287 a revised constant as long as no overflow occurs. */
6288 if ((code == EQ_EXPR || code == NE_EXPR)
6289 && TREE_CODE (arg1) == INTEGER_CST
6290 && (TREE_CODE (arg0) == PLUS_EXPR
6291 || TREE_CODE (arg0) == MINUS_EXPR)
6292 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6293 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
6294 ? MINUS_EXPR : PLUS_EXPR,
6295 arg1, TREE_OPERAND (arg0, 1), 0))
6296 && ! TREE_CONSTANT_OVERFLOW (tem))
6297 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6299 /* Similarly for a NEGATE_EXPR. */
6300 else if ((code == EQ_EXPR || code == NE_EXPR)
6301 && TREE_CODE (arg0) == NEGATE_EXPR
6302 && TREE_CODE (arg1) == INTEGER_CST
6303 && 0 != (tem = negate_expr (arg1))
6304 && TREE_CODE (tem) == INTEGER_CST
6305 && ! TREE_CONSTANT_OVERFLOW (tem))
6306 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6308 /* If we have X - Y == 0, we can convert that to X == Y and similarly
6309 for !=. Don't do this for ordered comparisons due to overflow. */
6310 else if ((code == NE_EXPR || code == EQ_EXPR)
6311 && integer_zerop (arg1) && TREE_CODE (arg0) == MINUS_EXPR)
6312 return fold (build (code, type,
6313 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1)));
6315 /* If we are widening one operand of an integer comparison,
6316 see if the other operand is similarly being widened. Perhaps we
6317 can do the comparison in the narrower type. */
6318 else if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
6319 && TREE_CODE (arg0) == NOP_EXPR
6320 && (tem = get_unwidened (arg0, NULL_TREE)) != arg0
6321 && (t1 = get_unwidened (arg1, TREE_TYPE (tem))) != 0
6322 && (TREE_TYPE (t1) == TREE_TYPE (tem)
6323 || (TREE_CODE (t1) == INTEGER_CST
6324 && int_fits_type_p (t1, TREE_TYPE (tem)))))
6325 return fold (build (code, type, tem, convert (TREE_TYPE (tem), t1)));
6327 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
6328 constant, we can simplify it. */
6329 else if (TREE_CODE (arg1) == INTEGER_CST
6330 && (TREE_CODE (arg0) == MIN_EXPR
6331 || TREE_CODE (arg0) == MAX_EXPR)
6332 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
6333 return optimize_minmax_comparison (t);
6335 /* If we are comparing an ABS_EXPR with a constant, we can
6336 convert all the cases into explicit comparisons, but they may
6337 well not be faster than doing the ABS and one comparison.
6338 But ABS (X) <= C is a range comparison, which becomes a subtraction
6339 and a comparison, and is probably faster. */
6340 else if (code == LE_EXPR && TREE_CODE (arg1) == INTEGER_CST
6341 && TREE_CODE (arg0) == ABS_EXPR
6342 && ! TREE_SIDE_EFFECTS (arg0)
6343 && (0 != (tem = negate_expr (arg1)))
6344 && TREE_CODE (tem) == INTEGER_CST
6345 && ! TREE_CONSTANT_OVERFLOW (tem))
6346 return fold (build (TRUTH_ANDIF_EXPR, type,
6347 build (GE_EXPR, type, TREE_OPERAND (arg0, 0), tem),
6348 build (LE_EXPR, type,
6349 TREE_OPERAND (arg0, 0), arg1)));
6351 /* If this is an EQ or NE comparison with zero and ARG0 is
6352 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
6353 two operations, but the latter can be done in one less insn
6354 on machines that have only two-operand insns or on which a
6355 constant cannot be the first operand. */
6356 if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR)
6357 && TREE_CODE (arg0) == BIT_AND_EXPR)
6359 if (TREE_CODE (TREE_OPERAND (arg0, 0)) == LSHIFT_EXPR
6360 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 0), 0)))
6362 fold (build (code, type,
6363 build (BIT_AND_EXPR, TREE_TYPE (arg0),
6365 TREE_TYPE (TREE_OPERAND (arg0, 0)),
6366 TREE_OPERAND (arg0, 1),
6367 TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)),
6368 convert (TREE_TYPE (arg0),
6371 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
6372 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
6374 fold (build (code, type,
6375 build (BIT_AND_EXPR, TREE_TYPE (arg0),
6377 TREE_TYPE (TREE_OPERAND (arg0, 1)),
6378 TREE_OPERAND (arg0, 0),
6379 TREE_OPERAND (TREE_OPERAND (arg0, 1), 1)),
6380 convert (TREE_TYPE (arg0),
6385 /* If this is an NE or EQ comparison of zero against the result of a
6386 signed MOD operation whose second operand is a power of 2, make
6387 the MOD operation unsigned since it is simpler and equivalent. */
6388 if ((code == NE_EXPR || code == EQ_EXPR)
6389 && integer_zerop (arg1)
6390 && ! TREE_UNSIGNED (TREE_TYPE (arg0))
6391 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
6392 || TREE_CODE (arg0) == CEIL_MOD_EXPR
6393 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
6394 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
6395 && integer_pow2p (TREE_OPERAND (arg0, 1)))
6397 tree newtype = unsigned_type (TREE_TYPE (arg0));
6398 tree newmod = build (TREE_CODE (arg0), newtype,
6399 convert (newtype, TREE_OPERAND (arg0, 0)),
6400 convert (newtype, TREE_OPERAND (arg0, 1)));
6402 return build (code, type, newmod, convert (newtype, arg1));
6405 /* If this is an NE comparison of zero with an AND of one, remove the
6406 comparison since the AND will give the correct value. */
6407 if (code == NE_EXPR && integer_zerop (arg1)
6408 && TREE_CODE (arg0) == BIT_AND_EXPR
6409 && integer_onep (TREE_OPERAND (arg0, 1)))
6410 return convert (type, arg0);
6412 /* If we have (A & C) == C where C is a power of 2, convert this into
6413 (A & C) != 0. Similarly for NE_EXPR. */
6414 if ((code == EQ_EXPR || code == NE_EXPR)
6415 && TREE_CODE (arg0) == BIT_AND_EXPR
6416 && integer_pow2p (TREE_OPERAND (arg0, 1))
6417 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
6418 return build (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
6419 arg0, integer_zero_node);
6421 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
6422 and similarly for >= into !=. */
6423 if ((code == LT_EXPR || code == GE_EXPR)
6424 && TREE_UNSIGNED (TREE_TYPE (arg0))
6425 && TREE_CODE (arg1) == LSHIFT_EXPR
6426 && integer_onep (TREE_OPERAND (arg1, 0)))
6427 return build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
6428 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
6429 TREE_OPERAND (arg1, 1)),
6430 convert (TREE_TYPE (arg0), integer_zero_node));
6432 else if ((code == LT_EXPR || code == GE_EXPR)
6433 && TREE_UNSIGNED (TREE_TYPE (arg0))
6434 && (TREE_CODE (arg1) == NOP_EXPR
6435 || TREE_CODE (arg1) == CONVERT_EXPR)
6436 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
6437 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
6439 build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
6440 convert (TREE_TYPE (arg0),
6441 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
6442 TREE_OPERAND (TREE_OPERAND (arg1, 0), 1))),
6443 convert (TREE_TYPE (arg0), integer_zero_node));
6445 /* Simplify comparison of something with itself. (For IEEE
6446 floating-point, we can only do some of these simplifications.) */
6447 if (operand_equal_p (arg0, arg1, 0))
6454 if (INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
6455 return constant_boolean_node (1, type);
6457 TREE_SET_CODE (t, code);
6461 /* For NE, we can only do this simplification if integer. */
6462 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
6464 /* ... fall through ... */
6467 return constant_boolean_node (0, type);
6473 /* An unsigned comparison against 0 can be simplified. */
6474 if (integer_zerop (arg1)
6475 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
6476 || POINTER_TYPE_P (TREE_TYPE (arg1)))
6477 && TREE_UNSIGNED (TREE_TYPE (arg1)))
6479 switch (TREE_CODE (t))
6483 TREE_SET_CODE (t, NE_EXPR);
6487 TREE_SET_CODE (t, EQ_EXPR);
6490 return omit_one_operand (type,
6491 convert (type, integer_one_node),
6494 return omit_one_operand (type,
6495 convert (type, integer_zero_node),
6502 /* Comparisons with the highest or lowest possible integer of
6503 the specified size will have known values and an unsigned
6504 <= 0x7fffffff can be simplified. */
6506 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1)));
6508 if (TREE_CODE (arg1) == INTEGER_CST
6509 && ! TREE_CONSTANT_OVERFLOW (arg1)
6510 && width <= HOST_BITS_PER_WIDE_INT
6511 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
6512 || POINTER_TYPE_P (TREE_TYPE (arg1))))
6514 if (TREE_INT_CST_HIGH (arg1) == 0
6515 && (TREE_INT_CST_LOW (arg1)
6516 == ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1)
6517 && ! TREE_UNSIGNED (TREE_TYPE (arg1)))
6518 switch (TREE_CODE (t))
6521 return omit_one_operand (type,
6522 convert (type, integer_zero_node),
6525 TREE_SET_CODE (t, EQ_EXPR);
6529 return omit_one_operand (type,
6530 convert (type, integer_one_node),
6533 TREE_SET_CODE (t, NE_EXPR);
6540 else if (TREE_INT_CST_HIGH (arg1) == -1
6541 && (- TREE_INT_CST_LOW (arg1)
6542 == ((unsigned HOST_WIDE_INT) 1 << (width - 1)))
6543 && ! TREE_UNSIGNED (TREE_TYPE (arg1)))
6544 switch (TREE_CODE (t))
6547 return omit_one_operand (type,
6548 convert (type, integer_zero_node),
6551 TREE_SET_CODE (t, EQ_EXPR);
6555 return omit_one_operand (type,
6556 convert (type, integer_one_node),
6559 TREE_SET_CODE (t, NE_EXPR);
6566 else if (TREE_INT_CST_HIGH (arg1) == 0
6567 && (TREE_INT_CST_LOW (arg1)
6568 == ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1)
6569 && TREE_UNSIGNED (TREE_TYPE (arg1)))
6571 switch (TREE_CODE (t))
6574 return fold (build (GE_EXPR, type,
6575 convert (signed_type (TREE_TYPE (arg0)),
6577 convert (signed_type (TREE_TYPE (arg1)),
6578 integer_zero_node)));
6580 return fold (build (LT_EXPR, type,
6581 convert (signed_type (TREE_TYPE (arg0)),
6583 convert (signed_type (TREE_TYPE (arg1)),
6584 integer_zero_node)));
6592 /* If we are comparing an expression that just has comparisons
6593 of two integer values, arithmetic expressions of those comparisons,
6594 and constants, we can simplify it. There are only three cases
6595 to check: the two values can either be equal, the first can be
6596 greater, or the second can be greater. Fold the expression for
6597 those three values. Since each value must be 0 or 1, we have
6598 eight possibilities, each of which corresponds to the constant 0
6599 or 1 or one of the six possible comparisons.
6601 This handles common cases like (a > b) == 0 but also handles
6602 expressions like ((x > y) - (y > x)) > 0, which supposedly
6603 occur in macroized code. */
6605 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
6607 tree cval1 = 0, cval2 = 0;
6610 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
6611 /* Don't handle degenerate cases here; they should already
6612 have been handled anyway. */
6613 && cval1 != 0 && cval2 != 0
6614 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
6615 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
6616 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
6617 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
6618 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
6619 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
6620 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
6622 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
6623 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
6625 /* We can't just pass T to eval_subst in case cval1 or cval2
6626 was the same as ARG1. */
6629 = fold (build (code, type,
6630 eval_subst (arg0, cval1, maxval, cval2, minval),
6633 = fold (build (code, type,
6634 eval_subst (arg0, cval1, maxval, cval2, maxval),
6637 = fold (build (code, type,
6638 eval_subst (arg0, cval1, minval, cval2, maxval),
6641 /* All three of these results should be 0 or 1. Confirm they
6642 are. Then use those values to select the proper code
6645 if ((integer_zerop (high_result)
6646 || integer_onep (high_result))
6647 && (integer_zerop (equal_result)
6648 || integer_onep (equal_result))
6649 && (integer_zerop (low_result)
6650 || integer_onep (low_result)))
6652 /* Make a 3-bit mask with the high-order bit being the
6653 value for `>', the next for '=', and the low for '<'. */
6654 switch ((integer_onep (high_result) * 4)
6655 + (integer_onep (equal_result) * 2)
6656 + integer_onep (low_result))
6660 return omit_one_operand (type, integer_zero_node, arg0);
6681 return omit_one_operand (type, integer_one_node, arg0);
6684 t = build (code, type, cval1, cval2);
6686 return save_expr (t);
6693 /* If this is a comparison of a field, we may be able to simplify it. */
6694 if ((TREE_CODE (arg0) == COMPONENT_REF
6695 || TREE_CODE (arg0) == BIT_FIELD_REF)
6696 && (code == EQ_EXPR || code == NE_EXPR)
6697 /* Handle the constant case even without -O
6698 to make sure the warnings are given. */
6699 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
6701 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
6705 /* If this is a comparison of complex values and either or both sides
6706 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
6707 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
6708 This may prevent needless evaluations. */
6709 if ((code == EQ_EXPR || code == NE_EXPR)
6710 && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
6711 && (TREE_CODE (arg0) == COMPLEX_EXPR
6712 || TREE_CODE (arg1) == COMPLEX_EXPR
6713 || TREE_CODE (arg0) == COMPLEX_CST
6714 || TREE_CODE (arg1) == COMPLEX_CST))
6716 tree subtype = TREE_TYPE (TREE_TYPE (arg0));
6717 tree real0, imag0, real1, imag1;
6719 arg0 = save_expr (arg0);
6720 arg1 = save_expr (arg1);
6721 real0 = fold (build1 (REALPART_EXPR, subtype, arg0));
6722 imag0 = fold (build1 (IMAGPART_EXPR, subtype, arg0));
6723 real1 = fold (build1 (REALPART_EXPR, subtype, arg1));
6724 imag1 = fold (build1 (IMAGPART_EXPR, subtype, arg1));
6726 return fold (build ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR
6729 fold (build (code, type, real0, real1)),
6730 fold (build (code, type, imag0, imag1))));
6733 /* From here on, the only cases we handle are when the result is
6734 known to be a constant.
6736 To compute GT, swap the arguments and do LT.
6737 To compute GE, do LT and invert the result.
6738 To compute LE, swap the arguments, do LT and invert the result.
6739 To compute NE, do EQ and invert the result.
6741 Therefore, the code below must handle only EQ and LT. */
6743 if (code == LE_EXPR || code == GT_EXPR)
6745 tem = arg0, arg0 = arg1, arg1 = tem;
6746 code = swap_tree_comparison (code);
6749 /* Note that it is safe to invert for real values here because we
6750 will check below in the one case that it matters. */
6754 if (code == NE_EXPR || code == GE_EXPR)
6757 code = invert_tree_comparison (code);
6760 /* Compute a result for LT or EQ if args permit;
6761 otherwise return T. */
6762 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
6764 if (code == EQ_EXPR)
6765 t1 = build_int_2 (tree_int_cst_equal (arg0, arg1), 0);
6767 t1 = build_int_2 ((TREE_UNSIGNED (TREE_TYPE (arg0))
6768 ? INT_CST_LT_UNSIGNED (arg0, arg1)
6769 : INT_CST_LT (arg0, arg1)),
6773 #if 0 /* This is no longer useful, but breaks some real code. */
6774 /* Assume a nonexplicit constant cannot equal an explicit one,
6775 since such code would be undefined anyway.
6776 Exception: on sysvr4, using #pragma weak,
6777 a label can come out as 0. */
6778 else if (TREE_CODE (arg1) == INTEGER_CST
6779 && !integer_zerop (arg1)
6780 && TREE_CONSTANT (arg0)
6781 && TREE_CODE (arg0) == ADDR_EXPR
6783 t1 = build_int_2 (0, 0);
6785 /* Two real constants can be compared explicitly. */
6786 else if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
6788 /* If either operand is a NaN, the result is false with two
6789 exceptions: First, an NE_EXPR is true on NaNs, but that case
6790 is already handled correctly since we will be inverting the
6791 result for NE_EXPR. Second, if we had inverted a LE_EXPR
6792 or a GE_EXPR into a LT_EXPR, we must return true so that it
6793 will be inverted into false. */
6795 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
6796 || REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
6797 t1 = build_int_2 (invert && code == LT_EXPR, 0);
6799 else if (code == EQ_EXPR)
6800 t1 = build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (arg0),
6801 TREE_REAL_CST (arg1)),
6804 t1 = build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (arg0),
6805 TREE_REAL_CST (arg1)),
6809 if (t1 == NULL_TREE)
6813 TREE_INT_CST_LOW (t1) ^= 1;
6815 TREE_TYPE (t1) = type;
6816 if (TREE_CODE (type) == BOOLEAN_TYPE)
6817 return truthvalue_conversion (t1);
6821 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
6822 so all simple results must be passed through pedantic_non_lvalue. */
6823 if (TREE_CODE (arg0) == INTEGER_CST)
6824 return pedantic_non_lvalue
6825 (TREE_OPERAND (t, (integer_zerop (arg0) ? 2 : 1)));
6826 else if (operand_equal_p (arg1, TREE_OPERAND (expr, 2), 0))
6827 return pedantic_omit_one_operand (type, arg1, arg0);
6829 /* If the second operand is zero, invert the comparison and swap
6830 the second and third operands. Likewise if the second operand
6831 is constant and the third is not or if the third operand is
6832 equivalent to the first operand of the comparison. */
6834 if (integer_zerop (arg1)
6835 || (TREE_CONSTANT (arg1) && ! TREE_CONSTANT (TREE_OPERAND (t, 2)))
6836 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
6837 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
6838 TREE_OPERAND (t, 2),
6839 TREE_OPERAND (arg0, 1))))
6841 /* See if this can be inverted. If it can't, possibly because
6842 it was a floating-point inequality comparison, don't do
6844 tem = invert_truthvalue (arg0);
6846 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
6848 t = build (code, type, tem,
6849 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
6851 /* arg1 should be the first argument of the new T. */
6852 arg1 = TREE_OPERAND (t, 1);
6857 /* If we have A op B ? A : C, we may be able to convert this to a
6858 simpler expression, depending on the operation and the values
6859 of B and C. IEEE floating point prevents this though,
6860 because A or B might be -0.0 or a NaN. */
6862 if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
6863 && (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
6864 || ! FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 0)))
6866 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
6867 arg1, TREE_OPERAND (arg0, 1)))
6869 tree arg2 = TREE_OPERAND (t, 2);
6870 enum tree_code comp_code = TREE_CODE (arg0);
6874 /* If we have A op 0 ? A : -A, this is A, -A, abs (A), or abs (-A),
6875 depending on the comparison operation. */
6876 if ((FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 1)))
6877 ? real_zerop (TREE_OPERAND (arg0, 1))
6878 : integer_zerop (TREE_OPERAND (arg0, 1)))
6879 && TREE_CODE (arg2) == NEGATE_EXPR
6880 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
6888 (convert (TREE_TYPE (TREE_OPERAND (t, 1)),
6892 return pedantic_non_lvalue (convert (type, arg1));
6895 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
6896 arg1 = convert (signed_type (TREE_TYPE (arg1)), arg1);
6897 return pedantic_non_lvalue
6898 (convert (type, fold (build1 (ABS_EXPR,
6899 TREE_TYPE (arg1), arg1))));
6902 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
6903 arg1 = convert (signed_type (TREE_TYPE (arg1)), arg1);
6904 return pedantic_non_lvalue
6905 (negate_expr (convert (type,
6906 fold (build1 (ABS_EXPR,
6913 /* If this is A != 0 ? A : 0, this is simply A. For ==, it is
6916 if (integer_zerop (TREE_OPERAND (arg0, 1)) && integer_zerop (arg2))
6918 if (comp_code == NE_EXPR)
6919 return pedantic_non_lvalue (convert (type, arg1));
6920 else if (comp_code == EQ_EXPR)
6921 return pedantic_non_lvalue (convert (type, integer_zero_node));
6924 /* If this is A op B ? A : B, this is either A, B, min (A, B),
6925 or max (A, B), depending on the operation. */
6927 if (operand_equal_for_comparison_p (TREE_OPERAND (arg0, 1),
6928 arg2, TREE_OPERAND (arg0, 0)))
6930 tree comp_op0 = TREE_OPERAND (arg0, 0);
6931 tree comp_op1 = TREE_OPERAND (arg0, 1);
6932 tree comp_type = TREE_TYPE (comp_op0);
6934 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
6935 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
6941 return pedantic_non_lvalue (convert (type, arg2));
6943 return pedantic_non_lvalue (convert (type, arg1));
6946 /* In C++ a ?: expression can be an lvalue, so put the
6947 operand which will be used if they are equal first
6948 so that we can convert this back to the
6949 corresponding COND_EXPR. */
6950 return pedantic_non_lvalue
6951 (convert (type, fold (build (MIN_EXPR, comp_type,
6952 (comp_code == LE_EXPR
6953 ? comp_op0 : comp_op1),
6954 (comp_code == LE_EXPR
6955 ? comp_op1 : comp_op0)))));
6959 return pedantic_non_lvalue
6960 (convert (type, fold (build (MAX_EXPR, comp_type,
6961 (comp_code == GE_EXPR
6962 ? comp_op0 : comp_op1),
6963 (comp_code == GE_EXPR
6964 ? comp_op1 : comp_op0)))));
6971 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
6972 we might still be able to simplify this. For example,
6973 if C1 is one less or one more than C2, this might have started
6974 out as a MIN or MAX and been transformed by this function.
6975 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
6977 if (INTEGRAL_TYPE_P (type)
6978 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6979 && TREE_CODE (arg2) == INTEGER_CST)
6983 /* We can replace A with C1 in this case. */
6984 arg1 = convert (type, TREE_OPERAND (arg0, 1));
6985 t = build (code, type, TREE_OPERAND (t, 0), arg1,
6986 TREE_OPERAND (t, 2));
6990 /* If C1 is C2 + 1, this is min(A, C2). */
6991 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
6992 && operand_equal_p (TREE_OPERAND (arg0, 1),
6993 const_binop (PLUS_EXPR, arg2,
6994 integer_one_node, 0), 1))
6995 return pedantic_non_lvalue
6996 (fold (build (MIN_EXPR, type, arg1, arg2)));
7000 /* If C1 is C2 - 1, this is min(A, C2). */
7001 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
7002 && operand_equal_p (TREE_OPERAND (arg0, 1),
7003 const_binop (MINUS_EXPR, arg2,
7004 integer_one_node, 0), 1))
7005 return pedantic_non_lvalue
7006 (fold (build (MIN_EXPR, type, arg1, arg2)));
7010 /* If C1 is C2 - 1, this is max(A, C2). */
7011 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
7012 && operand_equal_p (TREE_OPERAND (arg0, 1),
7013 const_binop (MINUS_EXPR, arg2,
7014 integer_one_node, 0), 1))
7015 return pedantic_non_lvalue
7016 (fold (build (MAX_EXPR, type, arg1, arg2)));
7020 /* If C1 is C2 + 1, this is max(A, C2). */
7021 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
7022 && operand_equal_p (TREE_OPERAND (arg0, 1),
7023 const_binop (PLUS_EXPR, arg2,
7024 integer_one_node, 0), 1))
7025 return pedantic_non_lvalue
7026 (fold (build (MAX_EXPR, type, arg1, arg2)));
7035 /* If the second operand is simpler than the third, swap them
7036 since that produces better jump optimization results. */
7037 if ((TREE_CONSTANT (arg1) || DECL_P (arg1)
7038 || TREE_CODE (arg1) == SAVE_EXPR)
7039 && ! (TREE_CONSTANT (TREE_OPERAND (t, 2))
7040 || DECL_P (TREE_OPERAND (t, 2))
7041 || TREE_CODE (TREE_OPERAND (t, 2)) == SAVE_EXPR))
7043 /* See if this can be inverted. If it can't, possibly because
7044 it was a floating-point inequality comparison, don't do
7046 tem = invert_truthvalue (arg0);
7048 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
7050 t = build (code, type, tem,
7051 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
7053 /* arg1 should be the first argument of the new T. */
7054 arg1 = TREE_OPERAND (t, 1);
7059 /* Convert A ? 1 : 0 to simply A. */
7060 if (integer_onep (TREE_OPERAND (t, 1))
7061 && integer_zerop (TREE_OPERAND (t, 2))
7062 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
7063 call to fold will try to move the conversion inside
7064 a COND, which will recurse. In that case, the COND_EXPR
7065 is probably the best choice, so leave it alone. */
7066 && type == TREE_TYPE (arg0))
7067 return pedantic_non_lvalue (arg0);
7069 /* Look for expressions of the form A & 2 ? 2 : 0. The result of this
7070 operation is simply A & 2. */
7072 if (integer_zerop (TREE_OPERAND (t, 2))
7073 && TREE_CODE (arg0) == NE_EXPR
7074 && integer_zerop (TREE_OPERAND (arg0, 1))
7075 && integer_pow2p (arg1)
7076 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
7077 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
7079 return pedantic_non_lvalue (convert (type, TREE_OPERAND (arg0, 0)));
7084 /* When pedantic, a compound expression can be neither an lvalue
7085 nor an integer constant expression. */
7086 if (TREE_SIDE_EFFECTS (arg0) || pedantic)
7088 /* Don't let (0, 0) be null pointer constant. */
7089 if (integer_zerop (arg1))
7090 return build1 (NOP_EXPR, type, arg1);
7091 return convert (type, arg1);
7095 return build_complex (type, arg0, arg1);
7099 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7101 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
7102 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
7103 TREE_OPERAND (arg0, 1));
7104 else if (TREE_CODE (arg0) == COMPLEX_CST)
7105 return TREE_REALPART (arg0);
7106 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7107 return fold (build (TREE_CODE (arg0), type,
7108 fold (build1 (REALPART_EXPR, type,
7109 TREE_OPERAND (arg0, 0))),
7110 fold (build1 (REALPART_EXPR,
7111 type, TREE_OPERAND (arg0, 1)))));
7115 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7116 return convert (type, integer_zero_node);
7117 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
7118 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
7119 TREE_OPERAND (arg0, 0));
7120 else if (TREE_CODE (arg0) == COMPLEX_CST)
7121 return TREE_IMAGPART (arg0);
7122 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7123 return fold (build (TREE_CODE (arg0), type,
7124 fold (build1 (IMAGPART_EXPR, type,
7125 TREE_OPERAND (arg0, 0))),
7126 fold (build1 (IMAGPART_EXPR, type,
7127 TREE_OPERAND (arg0, 1)))));
7130 /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
7132 case CLEANUP_POINT_EXPR:
7133 if (! has_cleanups (arg0))
7134 return TREE_OPERAND (t, 0);
7137 enum tree_code code0 = TREE_CODE (arg0);
7138 int kind0 = TREE_CODE_CLASS (code0);
7139 tree arg00 = TREE_OPERAND (arg0, 0);
7142 if (kind0 == '1' || code0 == TRUTH_NOT_EXPR)
7143 return fold (build1 (code0, type,
7144 fold (build1 (CLEANUP_POINT_EXPR,
7145 TREE_TYPE (arg00), arg00))));
7147 if (kind0 == '<' || kind0 == '2'
7148 || code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR
7149 || code0 == TRUTH_AND_EXPR || code0 == TRUTH_OR_EXPR
7150 || code0 == TRUTH_XOR_EXPR)
7152 arg01 = TREE_OPERAND (arg0, 1);
7154 if (TREE_CONSTANT (arg00)
7155 || ((code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR)
7156 && ! has_cleanups (arg00)))
7157 return fold (build (code0, type, arg00,
7158 fold (build1 (CLEANUP_POINT_EXPR,
7159 TREE_TYPE (arg01), arg01))));
7161 if (TREE_CONSTANT (arg01))
7162 return fold (build (code0, type,
7163 fold (build1 (CLEANUP_POINT_EXPR,
7164 TREE_TYPE (arg00), arg00)),
7173 } /* switch (code) */
7176 /* Determine if first argument is a multiple of second argument. Return 0 if
7177 it is not, or we cannot easily determined it to be.
7179 An example of the sort of thing we care about (at this point; this routine
7180 could surely be made more general, and expanded to do what the *_DIV_EXPR's
7181 fold cases do now) is discovering that
7183 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7189 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
7191 This code also handles discovering that
7193 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7195 is a multiple of 8 so we don't have to worry about dealing with a
7198 Note that we *look* inside a SAVE_EXPR only to determine how it was
7199 calculated; it is not safe for fold to do much of anything else with the
7200 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
7201 at run time. For example, the latter example above *cannot* be implemented
7202 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
7203 evaluation time of the original SAVE_EXPR is not necessarily the same at
7204 the time the new expression is evaluated. The only optimization of this
7205 sort that would be valid is changing
7207 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
7211 SAVE_EXPR (I) * SAVE_EXPR (J)
7213 (where the same SAVE_EXPR (J) is used in the original and the
7214 transformed version). */
7217 multiple_of_p (type, top, bottom)
7222 if (operand_equal_p (top, bottom, 0))
7225 if (TREE_CODE (type) != INTEGER_TYPE)
7228 switch (TREE_CODE (top))
7231 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
7232 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
7236 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
7237 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
7240 /* Can't handle conversions from non-integral or wider integral type. */
7241 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
7242 || (TYPE_PRECISION (type)
7243 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
7246 /* .. fall through ... */
7249 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
7252 if ((TREE_CODE (bottom) != INTEGER_CST)
7253 || (tree_int_cst_sgn (top) < 0)
7254 || (tree_int_cst_sgn (bottom) < 0))
7256 return integer_zerop (const_binop (TRUNC_MOD_EXPR,
7264 /* Return true if `t' is known to be non-negative. */
7267 tree_expr_nonnegative_p (t)
7270 switch (TREE_CODE (t))
7273 return tree_int_cst_sgn (t) >= 0;
7275 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
7276 && tree_expr_nonnegative_p (TREE_OPERAND (t, 2));
7278 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
7280 return rtl_expr_nonnegative_p (RTL_EXPR_RTL (t));
7283 /* We don't know sign of `t', so be safe and return false. */
7288 /* Return true if `r' is known to be non-negative.
7289 Only handles constants at the moment. */
7292 rtl_expr_nonnegative_p (r)
7295 switch (GET_CODE (r))
7298 return INTVAL (r) >= 0;
7301 if (GET_MODE (r) == VOIDmode)
7302 return CONST_DOUBLE_HIGH (r) >= 0;
7307 /* These are always nonnegative. */