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. */
31 /* The entry points in this file are fold, size_int_wide, size_binop
34 fold takes a tree as argument and returns a simplified tree.
36 size_binop takes a tree code for an arithmetic operation
37 and two operands that are trees, and produces a tree for the
38 result, assuming the type comes from `sizetype'.
40 size_int takes an integer value, and creates a tree constant
41 with type from `sizetype'.
43 force_fit_type takes a constant and prior overflow indicator, and
44 forces the value to fit the type. It returns an overflow indicator. */
56 static void encode PARAMS ((HOST_WIDE_INT *,
57 unsigned HOST_WIDE_INT,
59 static void decode PARAMS ((HOST_WIDE_INT *,
60 unsigned HOST_WIDE_INT *,
62 static tree negate_expr PARAMS ((tree));
63 static tree split_tree PARAMS ((tree, enum tree_code, tree *, tree *,
65 static tree associate_trees PARAMS ((tree, tree, enum tree_code, tree));
66 static tree int_const_binop PARAMS ((enum tree_code, tree, tree, int, int));
67 static void const_binop_1 PARAMS ((PTR));
68 static tree const_binop PARAMS ((enum tree_code, tree, tree, int));
69 static void fold_convert_1 PARAMS ((PTR));
70 static tree fold_convert PARAMS ((tree, tree));
71 static enum tree_code invert_tree_comparison PARAMS ((enum tree_code));
72 static enum tree_code swap_tree_comparison PARAMS ((enum tree_code));
73 static int truth_value_p PARAMS ((enum tree_code));
74 static int operand_equal_for_comparison_p PARAMS ((tree, tree, tree));
75 static int twoval_comparison_p PARAMS ((tree, tree *, tree *, int *));
76 static tree eval_subst PARAMS ((tree, tree, tree, tree, tree));
77 static tree omit_one_operand PARAMS ((tree, tree, tree));
78 static tree pedantic_omit_one_operand PARAMS ((tree, tree, tree));
79 static tree distribute_bit_expr PARAMS ((enum tree_code, tree, tree, tree));
80 static tree make_bit_field_ref PARAMS ((tree, tree, int, int, int));
81 static tree optimize_bit_field_compare PARAMS ((enum tree_code, tree,
83 static tree decode_field_reference PARAMS ((tree, HOST_WIDE_INT *,
85 enum machine_mode *, int *,
86 int *, tree *, tree *));
87 static int all_ones_mask_p PARAMS ((tree, int));
88 static int simple_operand_p PARAMS ((tree));
89 static tree range_binop PARAMS ((enum tree_code, tree, tree, int,
91 static tree make_range PARAMS ((tree, int *, tree *, tree *));
92 static tree build_range_check PARAMS ((tree, tree, int, tree, tree));
93 static int merge_ranges PARAMS ((int *, tree *, tree *, int, tree, tree,
95 static tree fold_range_test PARAMS ((tree));
96 static tree unextend PARAMS ((tree, int, int, tree));
97 static tree fold_truthop PARAMS ((enum tree_code, tree, tree, tree));
98 static tree optimize_minmax_comparison PARAMS ((tree));
99 static tree extract_muldiv PARAMS ((tree, tree, enum tree_code, tree));
100 static tree strip_compound_expr PARAMS ((tree, tree));
101 static int multiple_of_p PARAMS ((tree, tree, tree));
102 static tree constant_boolean_node PARAMS ((int, tree));
103 static int count_cond PARAMS ((tree, int));
106 #define BRANCH_COST 1
109 #if defined(HOST_EBCDIC)
110 /* bit 8 is significant in EBCDIC */
111 #define CHARMASK 0xff
113 #define CHARMASK 0x7f
117 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
118 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
119 and SUM1. Then this yields nonzero if overflow occurred during the
122 Overflow occurs if A and B have the same sign, but A and SUM differ in
123 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
125 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
127 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
128 We do that by representing the two-word integer in 4 words, with only
129 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
130 number. The value of the word is LOWPART + HIGHPART * BASE. */
133 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
134 #define HIGHPART(x) \
135 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
136 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
138 /* Unpack a two-word integer into 4 words.
139 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
140 WORDS points to the array of HOST_WIDE_INTs. */
143 encode (words, low, hi)
144 HOST_WIDE_INT *words;
145 unsigned HOST_WIDE_INT low;
148 words[0] = LOWPART (low);
149 words[1] = HIGHPART (low);
150 words[2] = LOWPART (hi);
151 words[3] = HIGHPART (hi);
154 /* Pack an array of 4 words into a two-word integer.
155 WORDS points to the array of words.
156 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
159 decode (words, low, hi)
160 HOST_WIDE_INT *words;
161 unsigned HOST_WIDE_INT *low;
164 *low = words[0] + words[1] * BASE;
165 *hi = words[2] + words[3] * BASE;
168 /* Make the integer constant T valid for its type by setting to 0 or 1 all
169 the bits in the constant that don't belong in the type.
171 Return 1 if a signed overflow occurs, 0 otherwise. If OVERFLOW is
172 nonzero, a signed overflow has already occurred in calculating T, so
175 Make the real constant T valid for its type by calling CHECK_FLOAT_VALUE,
179 force_fit_type (t, overflow)
183 unsigned HOST_WIDE_INT low;
187 if (TREE_CODE (t) == REAL_CST)
189 #ifdef CHECK_FLOAT_VALUE
190 CHECK_FLOAT_VALUE (TYPE_MODE (TREE_TYPE (t)), TREE_REAL_CST (t),
196 else if (TREE_CODE (t) != INTEGER_CST)
199 low = TREE_INT_CST_LOW (t);
200 high = TREE_INT_CST_HIGH (t);
202 if (POINTER_TYPE_P (TREE_TYPE (t)))
205 prec = TYPE_PRECISION (TREE_TYPE (t));
207 /* First clear all bits that are beyond the type's precision. */
209 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
211 else if (prec > HOST_BITS_PER_WIDE_INT)
212 TREE_INT_CST_HIGH (t)
213 &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
216 TREE_INT_CST_HIGH (t) = 0;
217 if (prec < HOST_BITS_PER_WIDE_INT)
218 TREE_INT_CST_LOW (t) &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
221 /* Unsigned types do not suffer sign extension or overflow. */
222 if (TREE_UNSIGNED (TREE_TYPE (t)))
225 /* If the value's sign bit is set, extend the sign. */
226 if (prec != 2 * HOST_BITS_PER_WIDE_INT
227 && (prec > HOST_BITS_PER_WIDE_INT
228 ? 0 != (TREE_INT_CST_HIGH (t)
230 << (prec - HOST_BITS_PER_WIDE_INT - 1)))
231 : 0 != (TREE_INT_CST_LOW (t)
232 & ((unsigned HOST_WIDE_INT) 1 << (prec - 1)))))
234 /* Value is negative:
235 set to 1 all the bits that are outside this type's precision. */
236 if (prec > HOST_BITS_PER_WIDE_INT)
237 TREE_INT_CST_HIGH (t)
238 |= ((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
241 TREE_INT_CST_HIGH (t) = -1;
242 if (prec < HOST_BITS_PER_WIDE_INT)
243 TREE_INT_CST_LOW (t) |= ((unsigned HOST_WIDE_INT) (-1) << prec);
247 /* Return nonzero if signed overflow occurred. */
249 ((overflow | (low ^ TREE_INT_CST_LOW (t)) | (high ^ TREE_INT_CST_HIGH (t)))
253 /* Add two doubleword integers with doubleword result.
254 Each argument is given as two `HOST_WIDE_INT' pieces.
255 One argument is L1 and H1; the other, L2 and H2.
256 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
259 add_double (l1, h1, l2, h2, lv, hv)
260 unsigned HOST_WIDE_INT l1, l2;
261 HOST_WIDE_INT h1, h2;
262 unsigned HOST_WIDE_INT *lv;
265 unsigned HOST_WIDE_INT l;
269 h = h1 + h2 + (l < l1);
273 return OVERFLOW_SUM_SIGN (h1, h2, h);
276 /* Negate a doubleword integer with doubleword result.
277 Return nonzero if the operation overflows, assuming it's signed.
278 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
279 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
282 neg_double (l1, h1, lv, hv)
283 unsigned HOST_WIDE_INT l1;
285 unsigned HOST_WIDE_INT *lv;
292 return (*hv & h1) < 0;
302 /* Multiply two doubleword integers with doubleword result.
303 Return nonzero if the operation overflows, assuming it's signed.
304 Each argument is given as two `HOST_WIDE_INT' pieces.
305 One argument is L1 and H1; the other, L2 and H2.
306 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
309 mul_double (l1, h1, l2, h2, lv, hv)
310 unsigned HOST_WIDE_INT l1, l2;
311 HOST_WIDE_INT h1, h2;
312 unsigned HOST_WIDE_INT *lv;
315 HOST_WIDE_INT arg1[4];
316 HOST_WIDE_INT arg2[4];
317 HOST_WIDE_INT prod[4 * 2];
318 register unsigned HOST_WIDE_INT carry;
319 register int i, j, k;
320 unsigned HOST_WIDE_INT toplow, neglow;
321 HOST_WIDE_INT tophigh, neghigh;
323 encode (arg1, l1, h1);
324 encode (arg2, l2, h2);
326 bzero ((char *) prod, sizeof prod);
328 for (i = 0; i < 4; i++)
331 for (j = 0; j < 4; j++)
334 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
335 carry += arg1[i] * arg2[j];
336 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
338 prod[k] = LOWPART (carry);
339 carry = HIGHPART (carry);
344 decode (prod, lv, hv); /* This ignores prod[4] through prod[4*2-1] */
346 /* Check for overflow by calculating the top half of the answer in full;
347 it should agree with the low half's sign bit. */
348 decode (prod+4, &toplow, &tophigh);
351 neg_double (l2, h2, &neglow, &neghigh);
352 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
356 neg_double (l1, h1, &neglow, &neghigh);
357 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
359 return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
362 /* Shift the doubleword integer in L1, H1 left by COUNT places
363 keeping only PREC bits of result.
364 Shift right if COUNT is negative.
365 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
366 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
369 lshift_double (l1, h1, count, prec, lv, hv, arith)
370 unsigned HOST_WIDE_INT l1;
371 HOST_WIDE_INT h1, count;
373 unsigned HOST_WIDE_INT *lv;
379 rshift_double (l1, h1, - count, prec, lv, hv, arith);
383 #ifdef SHIFT_COUNT_TRUNCATED
384 if (SHIFT_COUNT_TRUNCATED)
388 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
390 /* Shifting by the host word size is undefined according to the
391 ANSI standard, so we must handle this as a special case. */
395 else if (count >= HOST_BITS_PER_WIDE_INT)
397 *hv = l1 << (count - HOST_BITS_PER_WIDE_INT);
402 *hv = (((unsigned HOST_WIDE_INT) h1 << count)
403 | (l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
408 /* Shift the doubleword integer in L1, H1 right by COUNT places
409 keeping only PREC bits of result. COUNT must be positive.
410 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
411 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
414 rshift_double (l1, h1, count, prec, lv, hv, arith)
415 unsigned HOST_WIDE_INT l1;
416 HOST_WIDE_INT h1, count;
417 unsigned int prec ATTRIBUTE_UNUSED;
418 unsigned HOST_WIDE_INT *lv;
422 unsigned HOST_WIDE_INT signmask;
425 ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
428 #ifdef SHIFT_COUNT_TRUNCATED
429 if (SHIFT_COUNT_TRUNCATED)
433 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
435 /* Shifting by the host word size is undefined according to the
436 ANSI standard, so we must handle this as a special case. */
440 else if (count >= HOST_BITS_PER_WIDE_INT)
443 *lv = ((signmask << (2 * HOST_BITS_PER_WIDE_INT - count - 1) << 1)
444 | ((unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT)));
449 | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
450 *hv = ((signmask << (HOST_BITS_PER_WIDE_INT - count))
451 | ((unsigned HOST_WIDE_INT) h1 >> count));
455 /* Rotate the doubleword integer in L1, H1 left by COUNT places
456 keeping only PREC bits of result.
457 Rotate right if COUNT is negative.
458 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
461 lrotate_double (l1, h1, count, prec, lv, hv)
462 unsigned HOST_WIDE_INT l1;
463 HOST_WIDE_INT h1, count;
465 unsigned HOST_WIDE_INT *lv;
468 unsigned HOST_WIDE_INT s1l, s2l;
469 HOST_WIDE_INT s1h, s2h;
475 lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
476 rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
481 /* Rotate the doubleword integer in L1, H1 left by COUNT places
482 keeping only PREC bits of result. COUNT must be positive.
483 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
486 rrotate_double (l1, h1, count, prec, lv, hv)
487 unsigned HOST_WIDE_INT l1;
488 HOST_WIDE_INT h1, count;
490 unsigned HOST_WIDE_INT *lv;
493 unsigned HOST_WIDE_INT s1l, s2l;
494 HOST_WIDE_INT s1h, s2h;
500 rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
501 lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
506 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
507 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
508 CODE is a tree code for a kind of division, one of
509 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
511 It controls how the quotient is rounded to a integer.
512 Return nonzero if the operation overflows.
513 UNS nonzero says do unsigned division. */
516 div_and_round_double (code, uns,
517 lnum_orig, hnum_orig, lden_orig, hden_orig,
518 lquo, hquo, lrem, hrem)
521 unsigned HOST_WIDE_INT lnum_orig; /* num == numerator == dividend */
522 HOST_WIDE_INT hnum_orig;
523 unsigned HOST_WIDE_INT lden_orig; /* den == denominator == divisor */
524 HOST_WIDE_INT hden_orig;
525 unsigned HOST_WIDE_INT *lquo, *lrem;
526 HOST_WIDE_INT *hquo, *hrem;
529 HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
530 HOST_WIDE_INT den[4], quo[4];
532 unsigned HOST_WIDE_INT work;
533 unsigned HOST_WIDE_INT carry = 0;
534 unsigned HOST_WIDE_INT lnum = lnum_orig;
535 HOST_WIDE_INT hnum = hnum_orig;
536 unsigned HOST_WIDE_INT lden = lden_orig;
537 HOST_WIDE_INT hden = hden_orig;
540 if (hden == 0 && lden == 0)
541 overflow = 1, lden = 1;
543 /* calculate quotient sign and convert operands to unsigned. */
549 /* (minimum integer) / (-1) is the only overflow case. */
550 if (neg_double (lnum, hnum, &lnum, &hnum)
551 && ((HOST_WIDE_INT) lden & hden) == -1)
557 neg_double (lden, hden, &lden, &hden);
561 if (hnum == 0 && hden == 0)
562 { /* single precision */
564 /* This unsigned division rounds toward zero. */
570 { /* trivial case: dividend < divisor */
571 /* hden != 0 already checked. */
578 bzero ((char *) quo, sizeof quo);
580 bzero ((char *) num, sizeof num); /* to zero 9th element */
581 bzero ((char *) den, sizeof den);
583 encode (num, lnum, hnum);
584 encode (den, lden, hden);
586 /* Special code for when the divisor < BASE. */
587 if (hden == 0 && lden < (unsigned HOST_WIDE_INT) BASE)
589 /* hnum != 0 already checked. */
590 for (i = 4 - 1; i >= 0; i--)
592 work = num[i] + carry * BASE;
593 quo[i] = work / lden;
599 /* Full double precision division,
600 with thanks to Don Knuth's "Seminumerical Algorithms". */
601 int num_hi_sig, den_hi_sig;
602 unsigned HOST_WIDE_INT quo_est, scale;
604 /* Find the highest non-zero divisor digit. */
605 for (i = 4 - 1; ; i--)
611 /* Insure that the first digit of the divisor is at least BASE/2.
612 This is required by the quotient digit estimation algorithm. */
614 scale = BASE / (den[den_hi_sig] + 1);
616 { /* scale divisor and dividend */
618 for (i = 0; i <= 4 - 1; i++)
620 work = (num[i] * scale) + carry;
621 num[i] = LOWPART (work);
622 carry = HIGHPART (work);
627 for (i = 0; i <= 4 - 1; i++)
629 work = (den[i] * scale) + carry;
630 den[i] = LOWPART (work);
631 carry = HIGHPART (work);
632 if (den[i] != 0) den_hi_sig = i;
639 for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--)
641 /* Guess the next quotient digit, quo_est, by dividing the first
642 two remaining dividend digits by the high order quotient digit.
643 quo_est is never low and is at most 2 high. */
644 unsigned HOST_WIDE_INT tmp;
646 num_hi_sig = i + den_hi_sig + 1;
647 work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
648 if (num[num_hi_sig] != den[den_hi_sig])
649 quo_est = work / den[den_hi_sig];
653 /* Refine quo_est so it's usually correct, and at most one high. */
654 tmp = work - quo_est * den[den_hi_sig];
656 && (den[den_hi_sig - 1] * quo_est
657 > (tmp * BASE + num[num_hi_sig - 2])))
660 /* Try QUO_EST as the quotient digit, by multiplying the
661 divisor by QUO_EST and subtracting from the remaining dividend.
662 Keep in mind that QUO_EST is the I - 1st digit. */
665 for (j = 0; j <= den_hi_sig; j++)
667 work = quo_est * den[j] + carry;
668 carry = HIGHPART (work);
669 work = num[i + j] - LOWPART (work);
670 num[i + j] = LOWPART (work);
671 carry += HIGHPART (work) != 0;
674 /* If quo_est was high by one, then num[i] went negative and
675 we need to correct things. */
676 if (num[num_hi_sig] < carry)
679 carry = 0; /* add divisor back in */
680 for (j = 0; j <= den_hi_sig; j++)
682 work = num[i + j] + den[j] + carry;
683 carry = HIGHPART (work);
684 num[i + j] = LOWPART (work);
687 num [num_hi_sig] += carry;
690 /* Store the quotient digit. */
695 decode (quo, lquo, hquo);
698 /* if result is negative, make it so. */
700 neg_double (*lquo, *hquo, lquo, hquo);
702 /* compute trial remainder: rem = num - (quo * den) */
703 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
704 neg_double (*lrem, *hrem, lrem, hrem);
705 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
710 case TRUNC_MOD_EXPR: /* round toward zero */
711 case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
715 case FLOOR_MOD_EXPR: /* round toward negative infinity */
716 if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
719 add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
727 case CEIL_MOD_EXPR: /* round toward positive infinity */
728 if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
730 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
738 case ROUND_MOD_EXPR: /* round to closest integer */
740 unsigned HOST_WIDE_INT labs_rem = *lrem;
741 HOST_WIDE_INT habs_rem = *hrem;
742 unsigned HOST_WIDE_INT labs_den = lden, ltwice;
743 HOST_WIDE_INT habs_den = hden, htwice;
745 /* Get absolute values */
747 neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
749 neg_double (lden, hden, &labs_den, &habs_den);
751 /* If (2 * abs (lrem) >= abs (lden)) */
752 mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
753 labs_rem, habs_rem, <wice, &htwice);
755 if (((unsigned HOST_WIDE_INT) habs_den
756 < (unsigned HOST_WIDE_INT) htwice)
757 || (((unsigned HOST_WIDE_INT) habs_den
758 == (unsigned HOST_WIDE_INT) htwice)
759 && (labs_den < ltwice)))
763 add_double (*lquo, *hquo,
764 (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
767 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
779 /* compute true remainder: rem = num - (quo * den) */
780 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
781 neg_double (*lrem, *hrem, lrem, hrem);
782 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
786 #ifndef REAL_ARITHMETIC
787 /* Effectively truncate a real value to represent the nearest possible value
788 in a narrower mode. The result is actually represented in the same data
789 type as the argument, but its value is usually different.
791 A trap may occur during the FP operations and it is the responsibility
792 of the calling function to have a handler established. */
795 real_value_truncate (mode, arg)
796 enum machine_mode mode;
799 return REAL_VALUE_TRUNCATE (mode, arg);
802 #if TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
804 /* Check for infinity in an IEEE double precision number. */
810 /* The IEEE 64-bit double format. */
815 unsigned exponent : 11;
816 unsigned mantissa1 : 20;
821 unsigned mantissa1 : 20;
822 unsigned exponent : 11;
828 if (u.big_endian.sign == 1)
831 return (u.big_endian.exponent == 2047
832 && u.big_endian.mantissa1 == 0
833 && u.big_endian.mantissa2 == 0);
838 return (u.little_endian.exponent == 2047
839 && u.little_endian.mantissa1 == 0
840 && u.little_endian.mantissa2 == 0);
844 /* Check whether an IEEE double precision number is a NaN. */
850 /* The IEEE 64-bit double format. */
855 unsigned exponent : 11;
856 unsigned mantissa1 : 20;
861 unsigned mantissa1 : 20;
862 unsigned exponent : 11;
868 if (u.big_endian.sign == 1)
871 return (u.big_endian.exponent == 2047
872 && (u.big_endian.mantissa1 != 0
873 || u.big_endian.mantissa2 != 0));
878 return (u.little_endian.exponent == 2047
879 && (u.little_endian.mantissa1 != 0
880 || u.little_endian.mantissa2 != 0));
884 /* Check for a negative IEEE double precision number. */
890 /* The IEEE 64-bit double format. */
895 unsigned exponent : 11;
896 unsigned mantissa1 : 20;
901 unsigned mantissa1 : 20;
902 unsigned exponent : 11;
908 if (u.big_endian.sign == 1)
911 return u.big_endian.sign;
916 return u.little_endian.sign;
919 #else /* Target not IEEE */
921 /* Let's assume other float formats don't have infinity.
922 (This can be overridden by redefining REAL_VALUE_ISINF.) */
926 REAL_VALUE_TYPE x ATTRIBUTE_UNUSED;
931 /* Let's assume other float formats don't have NaNs.
932 (This can be overridden by redefining REAL_VALUE_ISNAN.) */
936 REAL_VALUE_TYPE x ATTRIBUTE_UNUSED;
941 /* Let's assume other float formats don't have minus zero.
942 (This can be overridden by redefining REAL_VALUE_NEGATIVE.) */
950 #endif /* Target not IEEE */
952 /* Try to change R into its exact multiplicative inverse in machine mode
953 MODE. Return nonzero function value if successful. */
956 exact_real_inverse (mode, r)
957 enum machine_mode mode;
966 #ifdef CHECK_FLOAT_VALUE
970 /* Usually disable if bounds checks are not reliable. */
971 if ((HOST_FLOAT_FORMAT != TARGET_FLOAT_FORMAT) && !flag_pretend_float)
974 /* Set array index to the less significant bits in the unions, depending
975 on the endian-ness of the host doubles.
976 Disable if insufficient information on the data structure. */
977 #if HOST_FLOAT_FORMAT == UNKNOWN_FLOAT_FORMAT
980 #if HOST_FLOAT_FORMAT == VAX_FLOAT_FORMAT
983 #if HOST_FLOAT_FORMAT == IBM_FLOAT_FORMAT
986 #define K (2 * HOST_FLOAT_WORDS_BIG_ENDIAN)
991 if (setjmp (float_error))
993 /* Don't do the optimization if there was an arithmetic error. */
995 set_float_handler (NULL_PTR);
998 set_float_handler (float_error);
1000 /* Domain check the argument. */
1005 #ifdef REAL_INFINITY
1006 if (REAL_VALUE_ISINF (x.d) || REAL_VALUE_ISNAN (x.d))
1010 /* Compute the reciprocal and check for numerical exactness.
1011 It is unnecessary to check all the significand bits to determine
1012 whether X is a power of 2. If X is not, then it is impossible for
1013 the bottom half significand of both X and 1/X to be all zero bits.
1014 Hence we ignore the data structure of the top half and examine only
1015 the low order bits of the two significands. */
1017 if (x.i[K] != 0 || x.i[K + 1] != 0 || t.i[K] != 0 || t.i[K + 1] != 0)
1020 /* Truncate to the required mode and range-check the result. */
1021 y.d = REAL_VALUE_TRUNCATE (mode, t.d);
1022 #ifdef CHECK_FLOAT_VALUE
1024 if (CHECK_FLOAT_VALUE (mode, y.d, i))
1028 /* Fail if truncation changed the value. */
1029 if (y.d != t.d || y.d == 0.0)
1032 #ifdef REAL_INFINITY
1033 if (REAL_VALUE_ISINF (y.d) || REAL_VALUE_ISNAN (y.d))
1037 /* Output the reciprocal and return success flag. */
1038 set_float_handler (NULL_PTR);
1043 /* Convert C9X hexadecimal floating point string constant S. Return
1044 real value type in mode MODE. This function uses the host computer's
1045 floating point arithmetic when there is no REAL_ARITHMETIC. */
1048 real_hex_to_f (s, mode)
1050 enum machine_mode mode;
1054 unsigned HOST_WIDE_INT low, high;
1055 int shcount, nrmcount, k;
1056 int sign, expsign, isfloat;
1057 int lost = 0;/* Nonzero low order bits shifted out and discarded. */
1058 int frexpon = 0; /* Bits after the decimal point. */
1059 int expon = 0; /* Value of exponent. */
1060 int decpt = 0; /* How many decimal points. */
1061 int gotp = 0; /* How many P's. */
1068 while (*p == ' ' || *p == '\t')
1071 /* Sign, if any, comes first. */
1079 /* The string is supposed to start with 0x or 0X . */
1083 if (*p == 'x' || *p == 'X')
1097 while ((c = *p) != '\0')
1099 if ((c >= '0' && c <= '9') || (c >= 'A' && c <= 'F')
1100 || (c >= 'a' && c <= 'f'))
1103 if (k >= 'a' && k <= 'f')
1110 if ((high & 0xf0000000) == 0)
1112 high = (high << 4) + ((low >> 28) & 15);
1113 low = (low << 4) + k;
1120 /* Record nonzero lost bits. */
1133 else if (c == 'p' || c == 'P')
1137 /* Sign of exponent. */
1144 /* Value of exponent.
1145 The exponent field is a decimal integer. */
1148 k = (*p++ & CHARMASK) - '0';
1149 expon = 10 * expon + k;
1153 /* F suffix is ambiguous in the significand part
1154 so it must appear after the decimal exponent field. */
1155 if (*p == 'f' || *p == 'F')
1163 else if (c == 'l' || c == 'L')
1172 /* Abort if last character read was not legitimate. */
1174 if ((c != '\0' && c != ' ' && c != '\n' && c != '\r') || (decpt > 1))
1177 /* There must be either one decimal point or one p. */
1178 if (decpt == 0 && gotp == 0)
1182 if (high == 0 && low == 0)
1194 /* Leave a high guard bit for carry-out. */
1195 if ((high & 0x80000000) != 0)
1198 low = (low >> 1) | (high << 31);
1203 if ((high & 0xffff8000) == 0)
1205 high = (high << 16) + ((low >> 16) & 0xffff);
1210 while ((high & 0xc0000000) == 0)
1212 high = (high << 1) + ((low >> 31) & 1);
1217 if (isfloat || GET_MODE_SIZE(mode) == UNITS_PER_WORD)
1219 /* Keep 24 bits precision, bits 0x7fffff80.
1220 Rounding bit is 0x40. */
1221 lost = lost | low | (high & 0x3f);
1225 if ((high & 0x80) || lost)
1232 /* We need real.c to do long double formats, so here default
1233 to double precision. */
1234 #if HOST_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
1236 Keep 53 bits precision, bits 0x7fffffff fffffc00.
1237 Rounding bit is low word 0x200. */
1238 lost = lost | (low & 0x1ff);
1241 if ((low & 0x400) || lost)
1243 low = (low + 0x200) & 0xfffffc00;
1250 /* Assume it's a VAX with 56-bit significand,
1251 bits 0x7fffffff ffffff80. */
1252 lost = lost | (low & 0x7f);
1255 if ((low & 0x80) || lost)
1257 low = (low + 0x40) & 0xffffff80;
1267 ip = REAL_VALUE_LDEXP (ip, 32) + (double) low;
1268 /* Apply shifts and exponent value as power of 2. */
1269 ip = REAL_VALUE_LDEXP (ip, expon - (nrmcount + frexpon));
1276 #endif /* no REAL_ARITHMETIC */
1278 /* Given T, an expression, return the negation of T. Allow for T to be
1279 null, in which case return null. */
1291 type = TREE_TYPE (t);
1292 STRIP_SIGN_NOPS (t);
1294 switch (TREE_CODE (t))
1298 if (! TREE_UNSIGNED (type)
1299 && 0 != (tem = fold (build1 (NEGATE_EXPR, type, t)))
1300 && ! TREE_OVERFLOW (tem))
1305 return convert (type, TREE_OPERAND (t, 0));
1308 /* - (A - B) -> B - A */
1309 if (! FLOAT_TYPE_P (type) || flag_fast_math)
1310 return convert (type,
1311 fold (build (MINUS_EXPR, TREE_TYPE (t),
1312 TREE_OPERAND (t, 1),
1313 TREE_OPERAND (t, 0))));
1320 return convert (type, build1 (NEGATE_EXPR, TREE_TYPE (t), t));
1323 /* Split a tree IN into a constant, literal and variable parts that could be
1324 combined with CODE to make IN. "constant" means an expression with
1325 TREE_CONSTANT but that isn't an actual constant. CODE must be a
1326 commutative arithmetic operation. Store the constant part into *CONP,
1327 the literal in &LITP and return the variable part. If a part isn't
1328 present, set it to null. If the tree does not decompose in this way,
1329 return the entire tree as the variable part and the other parts as null.
1331 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
1332 case, we negate an operand that was subtracted. If NEGATE_P is true, we
1333 are negating all of IN.
1335 If IN is itself a literal or constant, return it as appropriate.
1337 Note that we do not guarantee that any of the three values will be the
1338 same type as IN, but they will have the same signedness and mode. */
1341 split_tree (in, code, conp, litp, negate_p)
1343 enum tree_code code;
1352 /* Strip any conversions that don't change the machine mode or signedness. */
1353 STRIP_SIGN_NOPS (in);
1355 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST)
1357 else if (TREE_CONSTANT (in))
1360 else if (TREE_CODE (in) == code
1361 || (! FLOAT_TYPE_P (TREE_TYPE (in))
1362 /* We can associate addition and subtraction together (even
1363 though the C standard doesn't say so) for integers because
1364 the value is not affected. For reals, the value might be
1365 affected, so we can't. */
1366 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
1367 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
1369 tree op0 = TREE_OPERAND (in, 0);
1370 tree op1 = TREE_OPERAND (in, 1);
1371 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
1372 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
1374 /* First see if either of the operands is a literal, then a constant. */
1375 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
1376 *litp = op0, op0 = 0;
1377 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST)
1378 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
1380 if (op0 != 0 && TREE_CONSTANT (op0))
1381 *conp = op0, op0 = 0;
1382 else if (op1 != 0 && TREE_CONSTANT (op1))
1383 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
1385 /* If we haven't dealt with either operand, this is not a case we can
1386 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1387 if (op0 != 0 && op1 != 0)
1392 var = op1, neg_var_p = neg1_p;
1394 /* Now do any needed negations. */
1395 if (neg_litp_p) *litp = negate_expr (*litp);
1396 if (neg_conp_p) *conp = negate_expr (*conp);
1397 if (neg_var_p) var = negate_expr (var);
1404 var = negate_expr (var);
1405 *conp = negate_expr (*conp);
1406 *litp = negate_expr (*litp);
1412 /* Re-associate trees split by the above function. T1 and T2 are either
1413 expressions to associate or null. Return the new expression, if any. If
1414 we build an operation, do it in TYPE and with CODE, except if CODE is a
1415 MINUS_EXPR, in which case we use PLUS_EXPR since split_tree will already
1416 have taken care of the negations. */
1419 associate_trees (t1, t2, code, type)
1421 enum tree_code code;
1429 if (code == MINUS_EXPR)
1432 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1433 try to fold this since we will have infinite recursion. But do
1434 deal with any NEGATE_EXPRs. */
1435 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
1436 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1438 if (TREE_CODE (t1) == NEGATE_EXPR)
1439 return build (MINUS_EXPR, type, convert (type, t2),
1440 convert (type, TREE_OPERAND (t1, 0)));
1441 else if (TREE_CODE (t2) == NEGATE_EXPR)
1442 return build (MINUS_EXPR, type, convert (type, t1),
1443 convert (type, TREE_OPERAND (t2, 0)));
1445 return build (code, type, convert (type, t1), convert (type, t2));
1448 return fold (build (code, type, convert (type, t1), convert (type, t2)));
1451 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1452 to produce a new constant.
1454 If NOTRUNC is nonzero, do not truncate the result to fit the data type.
1455 If FORSIZE is nonzero, compute overflow for unsigned types. */
1458 int_const_binop (code, arg1, arg2, notrunc, forsize)
1459 enum tree_code code;
1460 register tree arg1, arg2;
1461 int notrunc, forsize;
1463 unsigned HOST_WIDE_INT int1l, int2l;
1464 HOST_WIDE_INT int1h, int2h;
1465 unsigned HOST_WIDE_INT low;
1467 unsigned HOST_WIDE_INT garbagel;
1468 HOST_WIDE_INT garbageh;
1470 int uns = TREE_UNSIGNED (TREE_TYPE (arg1));
1472 int no_overflow = 0;
1474 int1l = TREE_INT_CST_LOW (arg1);
1475 int1h = TREE_INT_CST_HIGH (arg1);
1476 int2l = TREE_INT_CST_LOW (arg2);
1477 int2h = TREE_INT_CST_HIGH (arg2);
1482 low = int1l | int2l, hi = int1h | int2h;
1486 low = int1l ^ int2l, hi = int1h ^ int2h;
1490 low = int1l & int2l, hi = int1h & int2h;
1493 case BIT_ANDTC_EXPR:
1494 low = int1l & ~int2l, hi = int1h & ~int2h;
1500 /* It's unclear from the C standard whether shifts can overflow.
1501 The following code ignores overflow; perhaps a C standard
1502 interpretation ruling is needed. */
1503 lshift_double (int1l, int1h, int2l, TYPE_PRECISION (TREE_TYPE (arg1)),
1511 lrotate_double (int1l, int1h, int2l, TYPE_PRECISION (TREE_TYPE (arg1)),
1516 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1520 neg_double (int2l, int2h, &low, &hi);
1521 add_double (int1l, int1h, low, hi, &low, &hi);
1522 overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
1526 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1529 case TRUNC_DIV_EXPR:
1530 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1531 case EXACT_DIV_EXPR:
1532 /* This is a shortcut for a common special case. */
1533 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1534 && ! TREE_CONSTANT_OVERFLOW (arg1)
1535 && ! TREE_CONSTANT_OVERFLOW (arg2)
1536 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1538 if (code == CEIL_DIV_EXPR)
1541 low = int1l / int2l, hi = 0;
1545 /* ... fall through ... */
1547 case ROUND_DIV_EXPR:
1548 if (int2h == 0 && int2l == 1)
1550 low = int1l, hi = int1h;
1553 if (int1l == int2l && int1h == int2h
1554 && ! (int1l == 0 && int1h == 0))
1559 overflow = div_and_round_double (code, uns,
1560 int1l, int1h, int2l, int2h,
1561 &low, &hi, &garbagel, &garbageh);
1564 case TRUNC_MOD_EXPR:
1565 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1566 /* This is a shortcut for a common special case. */
1567 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1568 && ! TREE_CONSTANT_OVERFLOW (arg1)
1569 && ! TREE_CONSTANT_OVERFLOW (arg2)
1570 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1572 if (code == CEIL_MOD_EXPR)
1574 low = int1l % int2l, hi = 0;
1578 /* ... fall through ... */
1580 case ROUND_MOD_EXPR:
1581 overflow = div_and_round_double (code, uns,
1582 int1l, int1h, int2l, int2h,
1583 &garbagel, &garbageh, &low, &hi);
1589 low = (((unsigned HOST_WIDE_INT) int1h
1590 < (unsigned HOST_WIDE_INT) int2h)
1591 || (((unsigned HOST_WIDE_INT) int1h
1592 == (unsigned HOST_WIDE_INT) int2h)
1595 low = (int1h < int2h
1596 || (int1h == int2h && int1l < int2l));
1598 if (low == (code == MIN_EXPR))
1599 low = int1l, hi = int1h;
1601 low = int2l, hi = int2h;
1608 if (forsize && hi == 0 && low < 10000)
1609 return size_int_type_wide (low, TREE_TYPE (arg1));
1612 t = build_int_2 (low, hi);
1613 TREE_TYPE (t) = TREE_TYPE (arg1);
1617 = ((notrunc ? (!uns || forsize) && overflow
1618 : force_fit_type (t, (!uns || forsize) && overflow) && ! no_overflow)
1619 | TREE_OVERFLOW (arg1)
1620 | TREE_OVERFLOW (arg2));
1622 /* If we're doing a size calculation, unsigned arithmetic does overflow.
1623 So check if force_fit_type truncated the value. */
1625 && ! TREE_OVERFLOW (t)
1626 && (TREE_INT_CST_HIGH (t) != hi
1627 || TREE_INT_CST_LOW (t) != low))
1628 TREE_OVERFLOW (t) = 1;
1630 TREE_CONSTANT_OVERFLOW (t) = (TREE_OVERFLOW (t)
1631 | TREE_CONSTANT_OVERFLOW (arg1)
1632 | TREE_CONSTANT_OVERFLOW (arg2));
1636 /* Define input and output argument for const_binop_1. */
1639 enum tree_code code; /* Input: tree code for operation*/
1640 tree type; /* Input: tree type for operation. */
1641 REAL_VALUE_TYPE d1, d2; /* Input: floating point operands. */
1642 tree t; /* Output: constant for result. */
1645 /* Do the real arithmetic for const_binop while protected by a
1646 float overflow handler. */
1649 const_binop_1 (data)
1652 struct cb_args *args = (struct cb_args *) data;
1653 REAL_VALUE_TYPE value;
1655 #ifdef REAL_ARITHMETIC
1656 REAL_ARITHMETIC (value, args->code, args->d1, args->d2);
1661 value = args->d1 + args->d2;
1665 value = args->d1 - args->d2;
1669 value = args->d1 * args->d2;
1673 #ifndef REAL_INFINITY
1678 value = args->d1 / args->d2;
1682 value = MIN (args->d1, args->d2);
1686 value = MAX (args->d1, args->d2);
1692 #endif /* no REAL_ARITHMETIC */
1695 = build_real (args->type,
1696 real_value_truncate (TYPE_MODE (args->type), value));
1699 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1700 constant. We assume ARG1 and ARG2 have the same data type, or at least
1701 are the same kind of constant and the same machine mode.
1703 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1706 const_binop (code, arg1, arg2, notrunc)
1707 enum tree_code code;
1708 register tree arg1, arg2;
1711 STRIP_NOPS (arg1); STRIP_NOPS (arg2);
1713 if (TREE_CODE (arg1) == INTEGER_CST)
1714 return int_const_binop (code, arg1, arg2, notrunc, 0);
1716 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1717 if (TREE_CODE (arg1) == REAL_CST)
1723 struct cb_args args;
1725 d1 = TREE_REAL_CST (arg1);
1726 d2 = TREE_REAL_CST (arg2);
1728 /* If either operand is a NaN, just return it. Otherwise, set up
1729 for floating-point trap; we return an overflow. */
1730 if (REAL_VALUE_ISNAN (d1))
1732 else if (REAL_VALUE_ISNAN (d2))
1735 /* Setup input for const_binop_1() */
1736 args.type = TREE_TYPE (arg1);
1741 if (do_float_handler (const_binop_1, (PTR) &args))
1742 /* Receive output from const_binop_1. */
1746 /* We got an exception from const_binop_1. */
1747 t = copy_node (arg1);
1752 = (force_fit_type (t, overflow)
1753 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
1754 TREE_CONSTANT_OVERFLOW (t)
1756 | TREE_CONSTANT_OVERFLOW (arg1)
1757 | TREE_CONSTANT_OVERFLOW (arg2);
1760 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
1761 if (TREE_CODE (arg1) == COMPLEX_CST)
1763 register tree type = TREE_TYPE (arg1);
1764 register tree r1 = TREE_REALPART (arg1);
1765 register tree i1 = TREE_IMAGPART (arg1);
1766 register tree r2 = TREE_REALPART (arg2);
1767 register tree i2 = TREE_IMAGPART (arg2);
1773 t = build_complex (type,
1774 const_binop (PLUS_EXPR, r1, r2, notrunc),
1775 const_binop (PLUS_EXPR, i1, i2, notrunc));
1779 t = build_complex (type,
1780 const_binop (MINUS_EXPR, r1, r2, notrunc),
1781 const_binop (MINUS_EXPR, i1, i2, notrunc));
1785 t = build_complex (type,
1786 const_binop (MINUS_EXPR,
1787 const_binop (MULT_EXPR,
1789 const_binop (MULT_EXPR,
1792 const_binop (PLUS_EXPR,
1793 const_binop (MULT_EXPR,
1795 const_binop (MULT_EXPR,
1802 register tree magsquared
1803 = const_binop (PLUS_EXPR,
1804 const_binop (MULT_EXPR, r2, r2, notrunc),
1805 const_binop (MULT_EXPR, i2, i2, notrunc),
1808 t = build_complex (type,
1810 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1811 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1812 const_binop (PLUS_EXPR,
1813 const_binop (MULT_EXPR, r1, r2,
1815 const_binop (MULT_EXPR, i1, i2,
1818 magsquared, notrunc),
1820 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1821 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1822 const_binop (MINUS_EXPR,
1823 const_binop (MULT_EXPR, i1, r2,
1825 const_binop (MULT_EXPR, r1, i2,
1828 magsquared, notrunc));
1840 /* Return an INTEGER_CST with value whose low-order HOST_BITS_PER_WIDE_INT
1841 bits are given by NUMBER and of the sizetype represented by KIND. */
1844 size_int_wide (number, kind)
1845 HOST_WIDE_INT number;
1846 enum size_type_kind kind;
1848 return size_int_type_wide (number, sizetype_tab[(int) kind]);
1851 /* Likewise, but the desired type is specified explicitly. */
1854 size_int_type_wide (number, type)
1855 HOST_WIDE_INT number;
1858 /* Type-size nodes already made for small sizes. */
1859 static tree size_table[2048 + 1];
1860 static int init_p = 0;
1863 if (ggc_p && ! init_p)
1865 ggc_add_tree_root ((tree *) size_table,
1866 sizeof size_table / sizeof (tree));
1870 /* If this is a positive number that fits in the table we use to hold
1871 cached entries, see if it is already in the table and put it there
1873 if (number >= 0 && number < (int) (sizeof size_table / sizeof size_table[0]))
1875 if (size_table[number] != 0)
1876 for (t = size_table[number]; t != 0; t = TREE_CHAIN (t))
1877 if (TREE_TYPE (t) == type)
1882 /* Make this a permanent node. */
1883 push_obstacks_nochange ();
1884 end_temporary_allocation ();
1887 t = build_int_2 (number, 0);
1888 TREE_TYPE (t) = type;
1889 TREE_CHAIN (t) = size_table[number];
1890 size_table[number] = t;
1898 t = build_int_2 (number, number < 0 ? -1 : 0);
1899 TREE_TYPE (t) = type;
1900 TREE_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (t) = force_fit_type (t, 0);
1904 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1905 is a tree code. The type of the result is taken from the operands.
1906 Both must be the same type integer type and it must be a size type.
1907 If the operands are constant, so is the result. */
1910 size_binop (code, arg0, arg1)
1911 enum tree_code code;
1914 tree type = TREE_TYPE (arg0);
1916 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1917 || type != TREE_TYPE (arg1))
1920 /* Handle the special case of two integer constants faster. */
1921 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1923 /* And some specific cases even faster than that. */
1924 if (code == PLUS_EXPR && integer_zerop (arg0))
1926 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1927 && integer_zerop (arg1))
1929 else if (code == MULT_EXPR && integer_onep (arg0))
1932 /* Handle general case of two integer constants. */
1933 return int_const_binop (code, arg0, arg1, 0, 1);
1936 if (arg0 == error_mark_node || arg1 == error_mark_node)
1937 return error_mark_node;
1939 return fold (build (code, type, arg0, arg1));
1942 /* Given two values, either both of sizetype or both of bitsizetype,
1943 compute the difference between the two values. Return the value
1944 in signed type corresponding to the type of the operands. */
1947 size_diffop (arg0, arg1)
1950 tree type = TREE_TYPE (arg0);
1953 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1954 || type != TREE_TYPE (arg1))
1957 /* If the type is already signed, just do the simple thing. */
1958 if (! TREE_UNSIGNED (type))
1959 return size_binop (MINUS_EXPR, arg0, arg1);
1961 ctype = (type == bitsizetype || type == ubitsizetype
1962 ? sbitsizetype : ssizetype);
1964 /* If either operand is not a constant, do the conversions to the signed
1965 type and subtract. The hardware will do the right thing with any
1966 overflow in the subtraction. */
1967 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
1968 return size_binop (MINUS_EXPR, convert (ctype, arg0),
1969 convert (ctype, arg1));
1971 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
1972 Otherwise, subtract the other way, convert to CTYPE (we know that can't
1973 overflow) and negate (which can't either). Special-case a result
1974 of zero while we're here. */
1975 if (tree_int_cst_equal (arg0, arg1))
1976 return convert (ctype, integer_zero_node);
1977 else if (tree_int_cst_lt (arg1, arg0))
1978 return convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
1980 return size_binop (MINUS_EXPR, convert (ctype, integer_zero_node),
1981 convert (ctype, size_binop (MINUS_EXPR, arg1, arg0)));
1984 /* This structure is used to communicate arguments to fold_convert_1. */
1987 tree arg1; /* Input: value to convert. */
1988 tree type; /* Input: type to convert value to. */
1989 tree t; /* Ouput: result of conversion. */
1992 /* Function to convert floating-point constants, protected by floating
1993 point exception handler. */
1996 fold_convert_1 (data)
1999 struct fc_args * args = (struct fc_args *) data;
2001 args->t = build_real (args->type,
2002 real_value_truncate (TYPE_MODE (args->type),
2003 TREE_REAL_CST (args->arg1)));
2006 /* Given T, a tree representing type conversion of ARG1, a constant,
2007 return a constant tree representing the result of conversion. */
2010 fold_convert (t, arg1)
2014 register tree type = TREE_TYPE (t);
2017 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
2019 if (TREE_CODE (arg1) == INTEGER_CST)
2021 /* If we would build a constant wider than GCC supports,
2022 leave the conversion unfolded. */
2023 if (TYPE_PRECISION (type) > 2 * HOST_BITS_PER_WIDE_INT)
2026 /* If we are trying to make a sizetype for a small integer, use
2027 size_int to pick up cached types to reduce duplicate nodes. */
2028 if (TREE_CODE (type) == INTEGER_CST && TYPE_IS_SIZETYPE (type)
2029 && compare_tree_int (arg1, 10000) < 0)
2030 return size_int_type_wide (TREE_INT_CST_LOW (arg1), type);
2032 /* Given an integer constant, make new constant with new type,
2033 appropriately sign-extended or truncated. */
2034 t = build_int_2 (TREE_INT_CST_LOW (arg1),
2035 TREE_INT_CST_HIGH (arg1));
2036 TREE_TYPE (t) = type;
2037 /* Indicate an overflow if (1) ARG1 already overflowed,
2038 or (2) force_fit_type indicates an overflow.
2039 Tell force_fit_type that an overflow has already occurred
2040 if ARG1 is a too-large unsigned value and T is signed.
2041 But don't indicate an overflow if converting a pointer. */
2043 = ((force_fit_type (t,
2044 (TREE_INT_CST_HIGH (arg1) < 0
2045 && (TREE_UNSIGNED (type)
2046 < TREE_UNSIGNED (TREE_TYPE (arg1)))))
2047 && ! POINTER_TYPE_P (TREE_TYPE (arg1)))
2048 || TREE_OVERFLOW (arg1));
2049 TREE_CONSTANT_OVERFLOW (t)
2050 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
2052 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
2053 else if (TREE_CODE (arg1) == REAL_CST)
2055 /* Don't initialize these, use assignments.
2056 Initialized local aggregates don't work on old compilers. */
2060 tree type1 = TREE_TYPE (arg1);
2063 x = TREE_REAL_CST (arg1);
2064 l = real_value_from_int_cst (type1, TYPE_MIN_VALUE (type));
2066 no_upper_bound = (TYPE_MAX_VALUE (type) == NULL);
2067 if (!no_upper_bound)
2068 u = real_value_from_int_cst (type1, TYPE_MAX_VALUE (type));
2070 /* See if X will be in range after truncation towards 0.
2071 To compensate for truncation, move the bounds away from 0,
2072 but reject if X exactly equals the adjusted bounds. */
2073 #ifdef REAL_ARITHMETIC
2074 REAL_ARITHMETIC (l, MINUS_EXPR, l, dconst1);
2075 if (!no_upper_bound)
2076 REAL_ARITHMETIC (u, PLUS_EXPR, u, dconst1);
2079 if (!no_upper_bound)
2082 /* If X is a NaN, use zero instead and show we have an overflow.
2083 Otherwise, range check. */
2084 if (REAL_VALUE_ISNAN (x))
2085 overflow = 1, x = dconst0;
2086 else if (! (REAL_VALUES_LESS (l, x)
2088 && REAL_VALUES_LESS (x, u)))
2091 #ifndef REAL_ARITHMETIC
2093 HOST_WIDE_INT low, high;
2094 HOST_WIDE_INT half_word
2095 = (HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2);
2100 high = (HOST_WIDE_INT) (x / half_word / half_word);
2101 x -= (REAL_VALUE_TYPE) high * half_word * half_word;
2102 if (x >= (REAL_VALUE_TYPE) half_word * half_word / 2)
2104 low = x - (REAL_VALUE_TYPE) half_word * half_word / 2;
2105 low |= (HOST_WIDE_INT) -1 << (HOST_BITS_PER_WIDE_INT - 1);
2108 low = (HOST_WIDE_INT) x;
2109 if (TREE_REAL_CST (arg1) < 0)
2110 neg_double (low, high, &low, &high);
2111 t = build_int_2 (low, high);
2115 HOST_WIDE_INT low, high;
2116 REAL_VALUE_TO_INT (&low, &high, x);
2117 t = build_int_2 (low, high);
2120 TREE_TYPE (t) = type;
2122 = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
2123 TREE_CONSTANT_OVERFLOW (t)
2124 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
2126 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
2127 TREE_TYPE (t) = type;
2129 else if (TREE_CODE (type) == REAL_TYPE)
2131 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
2132 if (TREE_CODE (arg1) == INTEGER_CST)
2133 return build_real_from_int_cst (type, arg1);
2134 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
2135 if (TREE_CODE (arg1) == REAL_CST)
2137 struct fc_args args;
2139 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
2142 TREE_TYPE (arg1) = type;
2146 /* Setup input for fold_convert_1() */
2150 if (do_float_handler (fold_convert_1, (PTR) &args))
2152 /* Receive output from fold_convert_1() */
2157 /* We got an exception from fold_convert_1() */
2159 t = copy_node (arg1);
2163 = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
2164 TREE_CONSTANT_OVERFLOW (t)
2165 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
2169 TREE_CONSTANT (t) = 1;
2173 /* Return an expr equal to X but certainly not valid as an lvalue. */
2181 /* These things are certainly not lvalues. */
2182 if (TREE_CODE (x) == NON_LVALUE_EXPR
2183 || TREE_CODE (x) == INTEGER_CST
2184 || TREE_CODE (x) == REAL_CST
2185 || TREE_CODE (x) == STRING_CST
2186 || TREE_CODE (x) == ADDR_EXPR)
2189 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
2190 TREE_CONSTANT (result) = TREE_CONSTANT (x);
2194 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
2195 Zero means allow extended lvalues. */
2197 int pedantic_lvalues;
2199 /* When pedantic, return an expr equal to X but certainly not valid as a
2200 pedantic lvalue. Otherwise, return X. */
2203 pedantic_non_lvalue (x)
2206 if (pedantic_lvalues)
2207 return non_lvalue (x);
2212 /* Given a tree comparison code, return the code that is the logical inverse
2213 of the given code. It is not safe to do this for floating-point
2214 comparisons, except for NE_EXPR and EQ_EXPR. */
2216 static enum tree_code
2217 invert_tree_comparison (code)
2218 enum tree_code code;
2239 /* Similar, but return the comparison that results if the operands are
2240 swapped. This is safe for floating-point. */
2242 static enum tree_code
2243 swap_tree_comparison (code)
2244 enum tree_code code;
2264 /* Return nonzero if CODE is a tree code that represents a truth value. */
2267 truth_value_p (code)
2268 enum tree_code code;
2270 return (TREE_CODE_CLASS (code) == '<'
2271 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2272 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2273 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
2276 /* Return nonzero if two operands are necessarily equal.
2277 If ONLY_CONST is non-zero, only return non-zero for constants.
2278 This function tests whether the operands are indistinguishable;
2279 it does not test whether they are equal using C's == operation.
2280 The distinction is important for IEEE floating point, because
2281 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2282 (2) two NaNs may be indistinguishable, but NaN!=NaN. */
2285 operand_equal_p (arg0, arg1, only_const)
2289 /* If both types don't have the same signedness, then we can't consider
2290 them equal. We must check this before the STRIP_NOPS calls
2291 because they may change the signedness of the arguments. */
2292 if (TREE_UNSIGNED (TREE_TYPE (arg0)) != TREE_UNSIGNED (TREE_TYPE (arg1)))
2298 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2299 /* This is needed for conversions and for COMPONENT_REF.
2300 Might as well play it safe and always test this. */
2301 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
2302 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
2303 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
2306 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
2307 We don't care about side effects in that case because the SAVE_EXPR
2308 takes care of that for us. In all other cases, two expressions are
2309 equal if they have no side effects. If we have two identical
2310 expressions with side effects that should be treated the same due
2311 to the only side effects being identical SAVE_EXPR's, that will
2312 be detected in the recursive calls below. */
2313 if (arg0 == arg1 && ! only_const
2314 && (TREE_CODE (arg0) == SAVE_EXPR
2315 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
2318 /* Next handle constant cases, those for which we can return 1 even
2319 if ONLY_CONST is set. */
2320 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
2321 switch (TREE_CODE (arg0))
2324 return (! TREE_CONSTANT_OVERFLOW (arg0)
2325 && ! TREE_CONSTANT_OVERFLOW (arg1)
2326 && tree_int_cst_equal (arg0, arg1));
2329 return (! TREE_CONSTANT_OVERFLOW (arg0)
2330 && ! TREE_CONSTANT_OVERFLOW (arg1)
2331 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
2332 TREE_REAL_CST (arg1)));
2335 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
2337 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
2341 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
2342 && ! memcmp (TREE_STRING_POINTER (arg0),
2343 TREE_STRING_POINTER (arg1),
2344 TREE_STRING_LENGTH (arg0)));
2347 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
2356 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
2359 /* Two conversions are equal only if signedness and modes match. */
2360 if ((TREE_CODE (arg0) == NOP_EXPR || TREE_CODE (arg0) == CONVERT_EXPR)
2361 && (TREE_UNSIGNED (TREE_TYPE (arg0))
2362 != TREE_UNSIGNED (TREE_TYPE (arg1))))
2365 return operand_equal_p (TREE_OPERAND (arg0, 0),
2366 TREE_OPERAND (arg1, 0), 0);
2370 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0)
2371 && operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1),
2375 /* For commutative ops, allow the other order. */
2376 return ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MULT_EXPR
2377 || TREE_CODE (arg0) == MIN_EXPR || TREE_CODE (arg0) == MAX_EXPR
2378 || TREE_CODE (arg0) == BIT_IOR_EXPR
2379 || TREE_CODE (arg0) == BIT_XOR_EXPR
2380 || TREE_CODE (arg0) == BIT_AND_EXPR
2381 || TREE_CODE (arg0) == NE_EXPR || TREE_CODE (arg0) == EQ_EXPR)
2382 && operand_equal_p (TREE_OPERAND (arg0, 0),
2383 TREE_OPERAND (arg1, 1), 0)
2384 && operand_equal_p (TREE_OPERAND (arg0, 1),
2385 TREE_OPERAND (arg1, 0), 0));
2388 /* If either of the pointer (or reference) expressions we are dereferencing
2389 contain a side effect, these cannot be equal. */
2390 if (TREE_SIDE_EFFECTS (arg0)
2391 || TREE_SIDE_EFFECTS (arg1))
2394 switch (TREE_CODE (arg0))
2397 return operand_equal_p (TREE_OPERAND (arg0, 0),
2398 TREE_OPERAND (arg1, 0), 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));
2408 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2409 TREE_OPERAND (arg1, 0), 0)
2410 && operand_equal_p (TREE_OPERAND (arg0, 1),
2411 TREE_OPERAND (arg1, 1), 0)
2412 && operand_equal_p (TREE_OPERAND (arg0, 2),
2413 TREE_OPERAND (arg1, 2), 0));
2419 if (TREE_CODE (arg0) == RTL_EXPR)
2420 return rtx_equal_p (RTL_EXPR_RTL (arg0), RTL_EXPR_RTL (arg1));
2428 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2429 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2431 When in doubt, return 0. */
2434 operand_equal_for_comparison_p (arg0, arg1, other)
2438 int unsignedp1, unsignedpo;
2439 tree primarg0, primarg1, primother;
2440 unsigned int correct_width;
2442 if (operand_equal_p (arg0, arg1, 0))
2445 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
2446 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
2449 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2450 and see if the inner values are the same. This removes any
2451 signedness comparison, which doesn't matter here. */
2452 primarg0 = arg0, primarg1 = arg1;
2453 STRIP_NOPS (primarg0); STRIP_NOPS (primarg1);
2454 if (operand_equal_p (primarg0, primarg1, 0))
2457 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2458 actual comparison operand, ARG0.
2460 First throw away any conversions to wider types
2461 already present in the operands. */
2463 primarg1 = get_narrower (arg1, &unsignedp1);
2464 primother = get_narrower (other, &unsignedpo);
2466 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
2467 if (unsignedp1 == unsignedpo
2468 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
2469 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
2471 tree type = TREE_TYPE (arg0);
2473 /* Make sure shorter operand is extended the right way
2474 to match the longer operand. */
2475 primarg1 = convert (signed_or_unsigned_type (unsignedp1,
2476 TREE_TYPE (primarg1)),
2479 if (operand_equal_p (arg0, convert (type, primarg1), 0))
2486 /* See if ARG is an expression that is either a comparison or is performing
2487 arithmetic on comparisons. The comparisons must only be comparing
2488 two different values, which will be stored in *CVAL1 and *CVAL2; if
2489 they are non-zero it means that some operands have already been found.
2490 No variables may be used anywhere else in the expression except in the
2491 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2492 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2494 If this is true, return 1. Otherwise, return zero. */
2497 twoval_comparison_p (arg, cval1, cval2, save_p)
2499 tree *cval1, *cval2;
2502 enum tree_code code = TREE_CODE (arg);
2503 char class = TREE_CODE_CLASS (code);
2505 /* We can handle some of the 'e' cases here. */
2506 if (class == 'e' && code == TRUTH_NOT_EXPR)
2508 else if (class == 'e'
2509 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
2510 || code == COMPOUND_EXPR))
2513 else if (class == 'e' && code == SAVE_EXPR && SAVE_EXPR_RTL (arg) == 0
2514 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
2516 /* If we've already found a CVAL1 or CVAL2, this expression is
2517 two complex to handle. */
2518 if (*cval1 || *cval2)
2528 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
2531 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
2532 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2533 cval1, cval2, save_p));
2539 if (code == COND_EXPR)
2540 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
2541 cval1, cval2, save_p)
2542 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2543 cval1, cval2, save_p)
2544 && twoval_comparison_p (TREE_OPERAND (arg, 2),
2545 cval1, cval2, save_p));
2549 /* First see if we can handle the first operand, then the second. For
2550 the second operand, we know *CVAL1 can't be zero. It must be that
2551 one side of the comparison is each of the values; test for the
2552 case where this isn't true by failing if the two operands
2555 if (operand_equal_p (TREE_OPERAND (arg, 0),
2556 TREE_OPERAND (arg, 1), 0))
2560 *cval1 = TREE_OPERAND (arg, 0);
2561 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
2563 else if (*cval2 == 0)
2564 *cval2 = TREE_OPERAND (arg, 0);
2565 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
2570 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
2572 else if (*cval2 == 0)
2573 *cval2 = TREE_OPERAND (arg, 1);
2574 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
2586 /* ARG is a tree that is known to contain just arithmetic operations and
2587 comparisons. Evaluate the operations in the tree substituting NEW0 for
2588 any occurrence of OLD0 as an operand of a comparison and likewise for
2592 eval_subst (arg, old0, new0, old1, new1)
2594 tree old0, new0, old1, new1;
2596 tree type = TREE_TYPE (arg);
2597 enum tree_code code = TREE_CODE (arg);
2598 char class = TREE_CODE_CLASS (code);
2600 /* We can handle some of the 'e' cases here. */
2601 if (class == 'e' && code == TRUTH_NOT_EXPR)
2603 else if (class == 'e'
2604 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2610 return fold (build1 (code, type,
2611 eval_subst (TREE_OPERAND (arg, 0),
2612 old0, new0, old1, new1)));
2615 return fold (build (code, type,
2616 eval_subst (TREE_OPERAND (arg, 0),
2617 old0, new0, old1, new1),
2618 eval_subst (TREE_OPERAND (arg, 1),
2619 old0, new0, old1, new1)));
2625 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
2628 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
2631 return fold (build (code, type,
2632 eval_subst (TREE_OPERAND (arg, 0),
2633 old0, new0, old1, new1),
2634 eval_subst (TREE_OPERAND (arg, 1),
2635 old0, new0, old1, new1),
2636 eval_subst (TREE_OPERAND (arg, 2),
2637 old0, new0, old1, new1)));
2641 /* fall through - ??? */
2645 tree arg0 = TREE_OPERAND (arg, 0);
2646 tree arg1 = TREE_OPERAND (arg, 1);
2648 /* We need to check both for exact equality and tree equality. The
2649 former will be true if the operand has a side-effect. In that
2650 case, we know the operand occurred exactly once. */
2652 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
2654 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
2657 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
2659 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
2662 return fold (build (code, type, arg0, arg1));
2670 /* Return a tree for the case when the result of an expression is RESULT
2671 converted to TYPE and OMITTED was previously an operand of the expression
2672 but is now not needed (e.g., we folded OMITTED * 0).
2674 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2675 the conversion of RESULT to TYPE. */
2678 omit_one_operand (type, result, omitted)
2679 tree type, result, omitted;
2681 tree t = convert (type, result);
2683 if (TREE_SIDE_EFFECTS (omitted))
2684 return build (COMPOUND_EXPR, type, omitted, t);
2686 return non_lvalue (t);
2689 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2692 pedantic_omit_one_operand (type, result, omitted)
2693 tree type, result, omitted;
2695 tree t = convert (type, result);
2697 if (TREE_SIDE_EFFECTS (omitted))
2698 return build (COMPOUND_EXPR, type, omitted, t);
2700 return pedantic_non_lvalue (t);
2705 /* Return a simplified tree node for the truth-negation of ARG. This
2706 never alters ARG itself. We assume that ARG is an operation that
2707 returns a truth value (0 or 1). */
2710 invert_truthvalue (arg)
2713 tree type = TREE_TYPE (arg);
2714 enum tree_code code = TREE_CODE (arg);
2716 if (code == ERROR_MARK)
2719 /* If this is a comparison, we can simply invert it, except for
2720 floating-point non-equality comparisons, in which case we just
2721 enclose a TRUTH_NOT_EXPR around what we have. */
2723 if (TREE_CODE_CLASS (code) == '<')
2725 if (FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg, 0)))
2726 && !flag_fast_math && code != NE_EXPR && code != EQ_EXPR)
2727 return build1 (TRUTH_NOT_EXPR, type, arg);
2729 return build (invert_tree_comparison (code), type,
2730 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
2736 return convert (type, build_int_2 (integer_zerop (arg), 0));
2738 case TRUTH_AND_EXPR:
2739 return build (TRUTH_OR_EXPR, type,
2740 invert_truthvalue (TREE_OPERAND (arg, 0)),
2741 invert_truthvalue (TREE_OPERAND (arg, 1)));
2744 return build (TRUTH_AND_EXPR, type,
2745 invert_truthvalue (TREE_OPERAND (arg, 0)),
2746 invert_truthvalue (TREE_OPERAND (arg, 1)));
2748 case TRUTH_XOR_EXPR:
2749 /* Here we can invert either operand. We invert the first operand
2750 unless the second operand is a TRUTH_NOT_EXPR in which case our
2751 result is the XOR of the first operand with the inside of the
2752 negation of the second operand. */
2754 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
2755 return build (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
2756 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
2758 return build (TRUTH_XOR_EXPR, type,
2759 invert_truthvalue (TREE_OPERAND (arg, 0)),
2760 TREE_OPERAND (arg, 1));
2762 case TRUTH_ANDIF_EXPR:
2763 return build (TRUTH_ORIF_EXPR, type,
2764 invert_truthvalue (TREE_OPERAND (arg, 0)),
2765 invert_truthvalue (TREE_OPERAND (arg, 1)));
2767 case TRUTH_ORIF_EXPR:
2768 return build (TRUTH_ANDIF_EXPR, type,
2769 invert_truthvalue (TREE_OPERAND (arg, 0)),
2770 invert_truthvalue (TREE_OPERAND (arg, 1)));
2772 case TRUTH_NOT_EXPR:
2773 return TREE_OPERAND (arg, 0);
2776 return build (COND_EXPR, type, TREE_OPERAND (arg, 0),
2777 invert_truthvalue (TREE_OPERAND (arg, 1)),
2778 invert_truthvalue (TREE_OPERAND (arg, 2)));
2781 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
2782 invert_truthvalue (TREE_OPERAND (arg, 1)));
2784 case WITH_RECORD_EXPR:
2785 return build (WITH_RECORD_EXPR, type,
2786 invert_truthvalue (TREE_OPERAND (arg, 0)),
2787 TREE_OPERAND (arg, 1));
2789 case NON_LVALUE_EXPR:
2790 return invert_truthvalue (TREE_OPERAND (arg, 0));
2795 return build1 (TREE_CODE (arg), type,
2796 invert_truthvalue (TREE_OPERAND (arg, 0)));
2799 if (!integer_onep (TREE_OPERAND (arg, 1)))
2801 return build (EQ_EXPR, type, arg, convert (type, integer_zero_node));
2804 return build1 (TRUTH_NOT_EXPR, type, arg);
2806 case CLEANUP_POINT_EXPR:
2807 return build1 (CLEANUP_POINT_EXPR, type,
2808 invert_truthvalue (TREE_OPERAND (arg, 0)));
2813 if (TREE_CODE (TREE_TYPE (arg)) != BOOLEAN_TYPE)
2815 return build1 (TRUTH_NOT_EXPR, type, arg);
2818 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
2819 operands are another bit-wise operation with a common input. If so,
2820 distribute the bit operations to save an operation and possibly two if
2821 constants are involved. For example, convert
2822 (A | B) & (A | C) into A | (B & C)
2823 Further simplification will occur if B and C are constants.
2825 If this optimization cannot be done, 0 will be returned. */
2828 distribute_bit_expr (code, type, arg0, arg1)
2829 enum tree_code code;
2836 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2837 || TREE_CODE (arg0) == code
2838 || (TREE_CODE (arg0) != BIT_AND_EXPR
2839 && TREE_CODE (arg0) != BIT_IOR_EXPR))
2842 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
2844 common = TREE_OPERAND (arg0, 0);
2845 left = TREE_OPERAND (arg0, 1);
2846 right = TREE_OPERAND (arg1, 1);
2848 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
2850 common = TREE_OPERAND (arg0, 0);
2851 left = TREE_OPERAND (arg0, 1);
2852 right = TREE_OPERAND (arg1, 0);
2854 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
2856 common = TREE_OPERAND (arg0, 1);
2857 left = TREE_OPERAND (arg0, 0);
2858 right = TREE_OPERAND (arg1, 1);
2860 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
2862 common = TREE_OPERAND (arg0, 1);
2863 left = TREE_OPERAND (arg0, 0);
2864 right = TREE_OPERAND (arg1, 0);
2869 return fold (build (TREE_CODE (arg0), type, common,
2870 fold (build (code, type, left, right))));
2873 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
2874 starting at BITPOS. The field is unsigned if UNSIGNEDP is non-zero. */
2877 make_bit_field_ref (inner, type, bitsize, bitpos, unsignedp)
2880 int bitsize, bitpos;
2883 tree result = build (BIT_FIELD_REF, type, inner,
2884 size_int (bitsize), bitsize_int (bitpos));
2886 TREE_UNSIGNED (result) = unsignedp;
2891 /* Optimize a bit-field compare.
2893 There are two cases: First is a compare against a constant and the
2894 second is a comparison of two items where the fields are at the same
2895 bit position relative to the start of a chunk (byte, halfword, word)
2896 large enough to contain it. In these cases we can avoid the shift
2897 implicit in bitfield extractions.
2899 For constants, we emit a compare of the shifted constant with the
2900 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
2901 compared. For two fields at the same position, we do the ANDs with the
2902 similar mask and compare the result of the ANDs.
2904 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
2905 COMPARE_TYPE is the type of the comparison, and LHS and RHS
2906 are the left and right operands of the comparison, respectively.
2908 If the optimization described above can be done, we return the resulting
2909 tree. Otherwise we return zero. */
2912 optimize_bit_field_compare (code, compare_type, lhs, rhs)
2913 enum tree_code code;
2917 HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
2918 tree type = TREE_TYPE (lhs);
2919 tree signed_type, unsigned_type;
2920 int const_p = TREE_CODE (rhs) == INTEGER_CST;
2921 enum machine_mode lmode, rmode, nmode;
2922 int lunsignedp, runsignedp;
2923 int lvolatilep = 0, rvolatilep = 0;
2924 unsigned int alignment;
2925 tree linner, rinner = NULL_TREE;
2929 /* Get all the information about the extractions being done. If the bit size
2930 if the same as the size of the underlying object, we aren't doing an
2931 extraction at all and so can do nothing. We also don't want to
2932 do anything if the inner expression is a PLACEHOLDER_EXPR since we
2933 then will no longer be able to replace it. */
2934 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
2935 &lunsignedp, &lvolatilep, &alignment);
2936 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
2937 || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
2942 /* If this is not a constant, we can only do something if bit positions,
2943 sizes, and signedness are the same. */
2944 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
2945 &runsignedp, &rvolatilep, &alignment);
2947 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
2948 || lunsignedp != runsignedp || offset != 0
2949 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
2953 /* See if we can find a mode to refer to this field. We should be able to,
2954 but fail if we can't. */
2955 nmode = get_best_mode (lbitsize, lbitpos,
2956 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
2957 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
2958 TYPE_ALIGN (TREE_TYPE (rinner))),
2959 word_mode, lvolatilep || rvolatilep);
2960 if (nmode == VOIDmode)
2963 /* Set signed and unsigned types of the precision of this mode for the
2965 signed_type = type_for_mode (nmode, 0);
2966 unsigned_type = type_for_mode (nmode, 1);
2968 /* Compute the bit position and size for the new reference and our offset
2969 within it. If the new reference is the same size as the original, we
2970 won't optimize anything, so return zero. */
2971 nbitsize = GET_MODE_BITSIZE (nmode);
2972 nbitpos = lbitpos & ~ (nbitsize - 1);
2974 if (nbitsize == lbitsize)
2977 if (BYTES_BIG_ENDIAN)
2978 lbitpos = nbitsize - lbitsize - lbitpos;
2980 /* Make the mask to be used against the extracted field. */
2981 mask = build_int_2 (~0, ~0);
2982 TREE_TYPE (mask) = unsigned_type;
2983 force_fit_type (mask, 0);
2984 mask = convert (unsigned_type, mask);
2985 mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
2986 mask = const_binop (RSHIFT_EXPR, mask,
2987 size_int (nbitsize - lbitsize - lbitpos), 0);
2990 /* If not comparing with constant, just rework the comparison
2992 return build (code, compare_type,
2993 build (BIT_AND_EXPR, unsigned_type,
2994 make_bit_field_ref (linner, unsigned_type,
2995 nbitsize, nbitpos, 1),
2997 build (BIT_AND_EXPR, unsigned_type,
2998 make_bit_field_ref (rinner, unsigned_type,
2999 nbitsize, nbitpos, 1),
3002 /* Otherwise, we are handling the constant case. See if the constant is too
3003 big for the field. Warn and return a tree of for 0 (false) if so. We do
3004 this not only for its own sake, but to avoid having to test for this
3005 error case below. If we didn't, we might generate wrong code.
3007 For unsigned fields, the constant shifted right by the field length should
3008 be all zero. For signed fields, the high-order bits should agree with
3013 if (! integer_zerop (const_binop (RSHIFT_EXPR,
3014 convert (unsigned_type, rhs),
3015 size_int (lbitsize), 0)))
3017 warning ("comparison is always %d due to width of bitfield",
3019 return convert (compare_type,
3021 ? integer_one_node : integer_zero_node));
3026 tree tem = const_binop (RSHIFT_EXPR, convert (signed_type, rhs),
3027 size_int (lbitsize - 1), 0);
3028 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
3030 warning ("comparison is always %d due to width of bitfield",
3032 return convert (compare_type,
3034 ? integer_one_node : integer_zero_node));
3038 /* Single-bit compares should always be against zero. */
3039 if (lbitsize == 1 && ! integer_zerop (rhs))
3041 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
3042 rhs = convert (type, integer_zero_node);
3045 /* Make a new bitfield reference, shift the constant over the
3046 appropriate number of bits and mask it with the computed mask
3047 (in case this was a signed field). If we changed it, make a new one. */
3048 lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1);
3051 TREE_SIDE_EFFECTS (lhs) = 1;
3052 TREE_THIS_VOLATILE (lhs) = 1;
3055 rhs = fold (const_binop (BIT_AND_EXPR,
3056 const_binop (LSHIFT_EXPR,
3057 convert (unsigned_type, rhs),
3058 size_int (lbitpos), 0),
3061 return build (code, compare_type,
3062 build (BIT_AND_EXPR, unsigned_type, lhs, mask),
3066 /* Subroutine for fold_truthop: decode a field reference.
3068 If EXP is a comparison reference, we return the innermost reference.
3070 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
3071 set to the starting bit number.
3073 If the innermost field can be completely contained in a mode-sized
3074 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
3076 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
3077 otherwise it is not changed.
3079 *PUNSIGNEDP is set to the signedness of the field.
3081 *PMASK is set to the mask used. This is either contained in a
3082 BIT_AND_EXPR or derived from the width of the field.
3084 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
3086 Return 0 if this is not a component reference or is one that we can't
3087 do anything with. */
3090 decode_field_reference (exp, pbitsize, pbitpos, pmode, punsignedp,
3091 pvolatilep, pmask, pand_mask)
3093 HOST_WIDE_INT *pbitsize, *pbitpos;
3094 enum machine_mode *pmode;
3095 int *punsignedp, *pvolatilep;
3100 tree mask, inner, offset;
3102 unsigned int precision;
3103 unsigned int alignment;
3105 /* All the optimizations using this function assume integer fields.
3106 There are problems with FP fields since the type_for_size call
3107 below can fail for, e.g., XFmode. */
3108 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
3113 if (TREE_CODE (exp) == BIT_AND_EXPR)
3115 and_mask = TREE_OPERAND (exp, 1);
3116 exp = TREE_OPERAND (exp, 0);
3117 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
3118 if (TREE_CODE (and_mask) != INTEGER_CST)
3123 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
3124 punsignedp, pvolatilep, &alignment);
3125 if ((inner == exp && and_mask == 0)
3126 || *pbitsize < 0 || offset != 0
3127 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
3130 /* Compute the mask to access the bitfield. */
3131 unsigned_type = type_for_size (*pbitsize, 1);
3132 precision = TYPE_PRECISION (unsigned_type);
3134 mask = build_int_2 (~0, ~0);
3135 TREE_TYPE (mask) = unsigned_type;
3136 force_fit_type (mask, 0);
3137 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3138 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3140 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
3142 mask = fold (build (BIT_AND_EXPR, unsigned_type,
3143 convert (unsigned_type, and_mask), mask));
3146 *pand_mask = and_mask;
3150 /* Return non-zero if MASK represents a mask of SIZE ones in the low-order
3154 all_ones_mask_p (mask, size)
3158 tree type = TREE_TYPE (mask);
3159 unsigned int precision = TYPE_PRECISION (type);
3162 tmask = build_int_2 (~0, ~0);
3163 TREE_TYPE (tmask) = signed_type (type);
3164 force_fit_type (tmask, 0);
3166 tree_int_cst_equal (mask,
3167 const_binop (RSHIFT_EXPR,
3168 const_binop (LSHIFT_EXPR, tmask,
3169 size_int (precision - size),
3171 size_int (precision - size), 0));
3174 /* Subroutine for fold_truthop: determine if an operand is simple enough
3175 to be evaluated unconditionally. */
3178 simple_operand_p (exp)
3181 /* Strip any conversions that don't change the machine mode. */
3182 while ((TREE_CODE (exp) == NOP_EXPR
3183 || TREE_CODE (exp) == CONVERT_EXPR)
3184 && (TYPE_MODE (TREE_TYPE (exp))
3185 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)))))
3186 exp = TREE_OPERAND (exp, 0);
3188 return (TREE_CODE_CLASS (TREE_CODE (exp)) == 'c'
3190 && ! TREE_ADDRESSABLE (exp)
3191 && ! TREE_THIS_VOLATILE (exp)
3192 && ! DECL_NONLOCAL (exp)
3193 /* Don't regard global variables as simple. They may be
3194 allocated in ways unknown to the compiler (shared memory,
3195 #pragma weak, etc). */
3196 && ! TREE_PUBLIC (exp)
3197 && ! DECL_EXTERNAL (exp)
3198 /* Loading a static variable is unduly expensive, but global
3199 registers aren't expensive. */
3200 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
3203 /* The following functions are subroutines to fold_range_test and allow it to
3204 try to change a logical combination of comparisons into a range test.
3207 X == 2 && X == 3 && X == 4 && X == 5
3211 (unsigned) (X - 2) <= 3
3213 We describe each set of comparisons as being either inside or outside
3214 a range, using a variable named like IN_P, and then describe the
3215 range with a lower and upper bound. If one of the bounds is omitted,
3216 it represents either the highest or lowest value of the type.
3218 In the comments below, we represent a range by two numbers in brackets
3219 preceded by a "+" to designate being inside that range, or a "-" to
3220 designate being outside that range, so the condition can be inverted by
3221 flipping the prefix. An omitted bound is represented by a "-". For
3222 example, "- [-, 10]" means being outside the range starting at the lowest
3223 possible value and ending at 10, in other words, being greater than 10.
3224 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
3227 We set up things so that the missing bounds are handled in a consistent
3228 manner so neither a missing bound nor "true" and "false" need to be
3229 handled using a special case. */
3231 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
3232 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
3233 and UPPER1_P are nonzero if the respective argument is an upper bound
3234 and zero for a lower. TYPE, if nonzero, is the type of the result; it
3235 must be specified for a comparison. ARG1 will be converted to ARG0's
3236 type if both are specified. */
3239 range_binop (code, type, arg0, upper0_p, arg1, upper1_p)
3240 enum tree_code code;
3243 int upper0_p, upper1_p;
3249 /* If neither arg represents infinity, do the normal operation.
3250 Else, if not a comparison, return infinity. Else handle the special
3251 comparison rules. Note that most of the cases below won't occur, but
3252 are handled for consistency. */
3254 if (arg0 != 0 && arg1 != 0)
3256 tem = fold (build (code, type != 0 ? type : TREE_TYPE (arg0),
3257 arg0, convert (TREE_TYPE (arg0), arg1)));
3259 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
3262 if (TREE_CODE_CLASS (code) != '<')
3265 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
3266 for neither. In real maths, we cannot assume open ended ranges are
3267 the same. But, this is computer arithmetic, where numbers are finite.
3268 We can therefore make the transformation of any unbounded range with
3269 the value Z, Z being greater than any representable number. This permits
3270 us to treat unbounded ranges as equal. */
3271 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
3272 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
3276 result = sgn0 == sgn1;
3279 result = sgn0 != sgn1;
3282 result = sgn0 < sgn1;
3285 result = sgn0 <= sgn1;
3288 result = sgn0 > sgn1;
3291 result = sgn0 >= sgn1;
3297 return convert (type, result ? integer_one_node : integer_zero_node);
3300 /* Given EXP, a logical expression, set the range it is testing into
3301 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
3302 actually being tested. *PLOW and *PHIGH will have be made the same type
3303 as the returned expression. If EXP is not a comparison, we will most
3304 likely not be returning a useful value and range. */
3307 make_range (exp, pin_p, plow, phigh)
3312 enum tree_code code;
3313 tree arg0 = NULL_TREE, arg1 = NULL_TREE, type = NULL_TREE;
3314 tree orig_type = NULL_TREE;
3316 tree low, high, n_low, n_high;
3318 /* Start with simply saying "EXP != 0" and then look at the code of EXP
3319 and see if we can refine the range. Some of the cases below may not
3320 happen, but it doesn't seem worth worrying about this. We "continue"
3321 the outer loop when we've changed something; otherwise we "break"
3322 the switch, which will "break" the while. */
3324 in_p = 0, low = high = convert (TREE_TYPE (exp), integer_zero_node);
3328 code = TREE_CODE (exp);
3330 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
3332 arg0 = TREE_OPERAND (exp, 0);
3333 if (TREE_CODE_CLASS (code) == '<'
3334 || TREE_CODE_CLASS (code) == '1'
3335 || TREE_CODE_CLASS (code) == '2')
3336 type = TREE_TYPE (arg0);
3337 if (TREE_CODE_CLASS (code) == '2'
3338 || TREE_CODE_CLASS (code) == '<'
3339 || (TREE_CODE_CLASS (code) == 'e'
3340 && TREE_CODE_LENGTH (code) > 1))
3341 arg1 = TREE_OPERAND (exp, 1);
3344 /* Set ORIG_TYPE as soon as TYPE is non-null so that we do not
3345 lose a cast by accident. */
3346 if (type != NULL_TREE && orig_type == NULL_TREE)
3351 case TRUTH_NOT_EXPR:
3352 in_p = ! in_p, exp = arg0;
3355 case EQ_EXPR: case NE_EXPR:
3356 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
3357 /* We can only do something if the range is testing for zero
3358 and if the second operand is an integer constant. Note that
3359 saying something is "in" the range we make is done by
3360 complementing IN_P since it will set in the initial case of
3361 being not equal to zero; "out" is leaving it alone. */
3362 if (low == 0 || high == 0
3363 || ! integer_zerop (low) || ! integer_zerop (high)
3364 || TREE_CODE (arg1) != INTEGER_CST)
3369 case NE_EXPR: /* - [c, c] */
3372 case EQ_EXPR: /* + [c, c] */
3373 in_p = ! in_p, low = high = arg1;
3375 case GT_EXPR: /* - [-, c] */
3376 low = 0, high = arg1;
3378 case GE_EXPR: /* + [c, -] */
3379 in_p = ! in_p, low = arg1, high = 0;
3381 case LT_EXPR: /* - [c, -] */
3382 low = arg1, high = 0;
3384 case LE_EXPR: /* + [-, c] */
3385 in_p = ! in_p, low = 0, high = arg1;
3393 /* If this is an unsigned comparison, we also know that EXP is
3394 greater than or equal to zero. We base the range tests we make
3395 on that fact, so we record it here so we can parse existing
3397 if (TREE_UNSIGNED (type) && (low == 0 || high == 0))
3399 if (! merge_ranges (&n_in_p, &n_low, &n_high, in_p, low, high,
3400 1, convert (type, integer_zero_node),
3404 in_p = n_in_p, low = n_low, high = n_high;
3406 /* If the high bound is missing, but we
3407 have a low bound, reverse the range so
3408 it goes from zero to the low bound minus 1. */
3409 if (high == 0 && low)
3412 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
3413 integer_one_node, 0);
3414 low = convert (type, integer_zero_node);
3420 /* (-x) IN [a,b] -> x in [-b, -a] */
3421 n_low = range_binop (MINUS_EXPR, type,
3422 convert (type, integer_zero_node), 0, high, 1);
3423 n_high = range_binop (MINUS_EXPR, type,
3424 convert (type, integer_zero_node), 0, low, 0);
3425 low = n_low, high = n_high;
3431 exp = build (MINUS_EXPR, type, negate_expr (arg0),
3432 convert (type, integer_one_node));
3435 case PLUS_EXPR: case MINUS_EXPR:
3436 if (TREE_CODE (arg1) != INTEGER_CST)
3439 /* If EXP is signed, any overflow in the computation is undefined,
3440 so we don't worry about it so long as our computations on
3441 the bounds don't overflow. For unsigned, overflow is defined
3442 and this is exactly the right thing. */
3443 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3444 type, low, 0, arg1, 0);
3445 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3446 type, high, 1, arg1, 0);
3447 if ((n_low != 0 && TREE_OVERFLOW (n_low))
3448 || (n_high != 0 && TREE_OVERFLOW (n_high)))
3451 /* Check for an unsigned range which has wrapped around the maximum
3452 value thus making n_high < n_low, and normalize it. */
3453 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
3455 low = range_binop (PLUS_EXPR, type, n_high, 0,
3456 integer_one_node, 0);
3457 high = range_binop (MINUS_EXPR, type, n_low, 0,
3458 integer_one_node, 0);
3460 /* If the range is of the form +/- [ x+1, x ], we won't
3461 be able to normalize it. But then, it represents the
3462 whole range or the empty set, so make it
3464 if (tree_int_cst_equal (n_low, low)
3465 && tree_int_cst_equal (n_high, high))
3471 low = n_low, high = n_high;
3476 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
3477 if (TYPE_PRECISION (type) > TYPE_PRECISION (orig_type))
3480 if (! INTEGRAL_TYPE_P (type)
3481 || (low != 0 && ! int_fits_type_p (low, type))
3482 || (high != 0 && ! int_fits_type_p (high, type)))
3485 n_low = low, n_high = high;
3488 n_low = convert (type, n_low);
3491 n_high = convert (type, n_high);
3493 /* If we're converting from an unsigned to a signed type,
3494 we will be doing the comparison as unsigned. The tests above
3495 have already verified that LOW and HIGH are both positive.
3497 So we have to make sure that the original unsigned value will
3498 be interpreted as positive. */
3499 if (TREE_UNSIGNED (type) && ! TREE_UNSIGNED (TREE_TYPE (exp)))
3501 tree equiv_type = type_for_mode (TYPE_MODE (type), 1);
3504 /* A range without an upper bound is, naturally, unbounded.
3505 Since convert would have cropped a very large value, use
3506 the max value for the destination type. */
3508 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
3509 : TYPE_MAX_VALUE (type);
3511 high_positive = fold (build (RSHIFT_EXPR, type,
3512 convert (type, high_positive),
3513 convert (type, integer_one_node)));
3515 /* If the low bound is specified, "and" the range with the
3516 range for which the original unsigned value will be
3520 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3522 1, convert (type, integer_zero_node),
3526 in_p = (n_in_p == in_p);
3530 /* Otherwise, "or" the range with the range of the input
3531 that will be interpreted as negative. */
3532 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3534 1, convert (type, integer_zero_node),
3538 in_p = (in_p != n_in_p);
3543 low = n_low, high = n_high;
3553 /* If EXP is a constant, we can evaluate whether this is true or false. */
3554 if (TREE_CODE (exp) == INTEGER_CST)
3556 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
3558 && integer_onep (range_binop (LE_EXPR, integer_type_node,
3564 *pin_p = in_p, *plow = low, *phigh = high;
3568 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3569 type, TYPE, return an expression to test if EXP is in (or out of, depending
3570 on IN_P) the range. */
3573 build_range_check (type, exp, in_p, low, high)
3579 tree etype = TREE_TYPE (exp);
3583 && (0 != (value = build_range_check (type, exp, 1, low, high))))
3584 return invert_truthvalue (value);
3586 else if (low == 0 && high == 0)
3587 return convert (type, integer_one_node);
3590 return fold (build (LE_EXPR, type, exp, high));
3593 return fold (build (GE_EXPR, type, exp, low));
3595 else if (operand_equal_p (low, high, 0))
3596 return fold (build (EQ_EXPR, type, exp, low));
3598 else if (TREE_UNSIGNED (etype) && integer_zerop (low))
3599 return build_range_check (type, exp, 1, 0, high);
3601 else if (integer_zerop (low))
3603 utype = unsigned_type (etype);
3604 return build_range_check (type, convert (utype, exp), 1, 0,
3605 convert (utype, high));
3608 else if (0 != (value = const_binop (MINUS_EXPR, high, low, 0))
3609 && ! TREE_OVERFLOW (value))
3610 return build_range_check (type,
3611 fold (build (MINUS_EXPR, etype, exp, low)),
3612 1, convert (etype, integer_zero_node), value);
3617 /* Given two ranges, see if we can merge them into one. Return 1 if we
3618 can, 0 if we can't. Set the output range into the specified parameters. */
3621 merge_ranges (pin_p, plow, phigh, in0_p, low0, high0, in1_p, low1, high1)
3625 tree low0, high0, low1, high1;
3633 int lowequal = ((low0 == 0 && low1 == 0)
3634 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3635 low0, 0, low1, 0)));
3636 int highequal = ((high0 == 0 && high1 == 0)
3637 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3638 high0, 1, high1, 1)));
3640 /* Make range 0 be the range that starts first, or ends last if they
3641 start at the same value. Swap them if it isn't. */
3642 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
3645 && integer_onep (range_binop (GT_EXPR, integer_type_node,
3646 high1, 1, high0, 1))))
3648 temp = in0_p, in0_p = in1_p, in1_p = temp;
3649 tem = low0, low0 = low1, low1 = tem;
3650 tem = high0, high0 = high1, high1 = tem;
3653 /* Now flag two cases, whether the ranges are disjoint or whether the
3654 second range is totally subsumed in the first. Note that the tests
3655 below are simplified by the ones above. */
3656 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
3657 high0, 1, low1, 0));
3658 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
3659 high1, 1, high0, 1));
3661 /* We now have four cases, depending on whether we are including or
3662 excluding the two ranges. */
3665 /* If they don't overlap, the result is false. If the second range
3666 is a subset it is the result. Otherwise, the range is from the start
3667 of the second to the end of the first. */
3669 in_p = 0, low = high = 0;
3671 in_p = 1, low = low1, high = high1;
3673 in_p = 1, low = low1, high = high0;
3676 else if (in0_p && ! in1_p)
3678 /* If they don't overlap, the result is the first range. If they are
3679 equal, the result is false. If the second range is a subset of the
3680 first, and the ranges begin at the same place, we go from just after
3681 the end of the first range to the end of the second. If the second
3682 range is not a subset of the first, or if it is a subset and both
3683 ranges end at the same place, the range starts at the start of the
3684 first range and ends just before the second range.
3685 Otherwise, we can't describe this as a single range. */
3687 in_p = 1, low = low0, high = high0;
3688 else if (lowequal && highequal)
3689 in_p = 0, low = high = 0;
3690 else if (subset && lowequal)
3692 in_p = 1, high = high0;
3693 low = range_binop (PLUS_EXPR, NULL_TREE, high1, 0,
3694 integer_one_node, 0);
3696 else if (! subset || highequal)
3698 in_p = 1, low = low0;
3699 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
3700 integer_one_node, 0);
3706 else if (! in0_p && in1_p)
3708 /* If they don't overlap, the result is the second range. If the second
3709 is a subset of the first, the result is false. Otherwise,
3710 the range starts just after the first range and ends at the
3711 end of the second. */
3713 in_p = 1, low = low1, high = high1;
3714 else if (subset || highequal)
3715 in_p = 0, low = high = 0;
3718 in_p = 1, high = high1;
3719 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
3720 integer_one_node, 0);
3726 /* The case where we are excluding both ranges. Here the complex case
3727 is if they don't overlap. In that case, the only time we have a
3728 range is if they are adjacent. If the second is a subset of the
3729 first, the result is the first. Otherwise, the range to exclude
3730 starts at the beginning of the first range and ends at the end of the
3734 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
3735 range_binop (PLUS_EXPR, NULL_TREE,
3737 integer_one_node, 1),
3739 in_p = 0, low = low0, high = high1;
3744 in_p = 0, low = low0, high = high0;
3746 in_p = 0, low = low0, high = high1;
3749 *pin_p = in_p, *plow = low, *phigh = high;
3753 /* EXP is some logical combination of boolean tests. See if we can
3754 merge it into some range test. Return the new tree if so. */
3757 fold_range_test (exp)
3760 int or_op = (TREE_CODE (exp) == TRUTH_ORIF_EXPR
3761 || TREE_CODE (exp) == TRUTH_OR_EXPR);
3762 int in0_p, in1_p, in_p;
3763 tree low0, low1, low, high0, high1, high;
3764 tree lhs = make_range (TREE_OPERAND (exp, 0), &in0_p, &low0, &high0);
3765 tree rhs = make_range (TREE_OPERAND (exp, 1), &in1_p, &low1, &high1);
3768 /* If this is an OR operation, invert both sides; we will invert
3769 again at the end. */
3771 in0_p = ! in0_p, in1_p = ! in1_p;
3773 /* If both expressions are the same, if we can merge the ranges, and we
3774 can build the range test, return it or it inverted. If one of the
3775 ranges is always true or always false, consider it to be the same
3776 expression as the other. */
3777 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
3778 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
3780 && 0 != (tem = (build_range_check (TREE_TYPE (exp),
3782 : rhs != 0 ? rhs : integer_zero_node,
3784 return or_op ? invert_truthvalue (tem) : tem;
3786 /* On machines where the branch cost is expensive, if this is a
3787 short-circuited branch and the underlying object on both sides
3788 is the same, make a non-short-circuit operation. */
3789 else if (BRANCH_COST >= 2
3790 && (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3791 || TREE_CODE (exp) == TRUTH_ORIF_EXPR)
3792 && operand_equal_p (lhs, rhs, 0))
3794 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
3795 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
3796 which cases we can't do this. */
3797 if (simple_operand_p (lhs))
3798 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3799 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3800 TREE_TYPE (exp), TREE_OPERAND (exp, 0),
3801 TREE_OPERAND (exp, 1));
3803 else if (global_bindings_p () == 0
3804 && ! contains_placeholder_p (lhs))
3806 tree common = save_expr (lhs);
3808 if (0 != (lhs = build_range_check (TREE_TYPE (exp), common,
3809 or_op ? ! in0_p : in0_p,
3811 && (0 != (rhs = build_range_check (TREE_TYPE (exp), common,
3812 or_op ? ! in1_p : in1_p,
3814 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3815 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3816 TREE_TYPE (exp), lhs, rhs);
3823 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
3824 bit value. Arrange things so the extra bits will be set to zero if and
3825 only if C is signed-extended to its full width. If MASK is nonzero,
3826 it is an INTEGER_CST that should be AND'ed with the extra bits. */
3829 unextend (c, p, unsignedp, mask)
3835 tree type = TREE_TYPE (c);
3836 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
3839 if (p == modesize || unsignedp)
3842 /* We work by getting just the sign bit into the low-order bit, then
3843 into the high-order bit, then sign-extend. We then XOR that value
3845 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
3846 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
3848 /* We must use a signed type in order to get an arithmetic right shift.
3849 However, we must also avoid introducing accidental overflows, so that
3850 a subsequent call to integer_zerop will work. Hence we must
3851 do the type conversion here. At this point, the constant is either
3852 zero or one, and the conversion to a signed type can never overflow.
3853 We could get an overflow if this conversion is done anywhere else. */
3854 if (TREE_UNSIGNED (type))
3855 temp = convert (signed_type (type), temp);
3857 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
3858 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
3860 temp = const_binop (BIT_AND_EXPR, temp, convert (TREE_TYPE (c), mask), 0);
3861 /* If necessary, convert the type back to match the type of C. */
3862 if (TREE_UNSIGNED (type))
3863 temp = convert (type, temp);
3865 return convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
3868 /* Find ways of folding logical expressions of LHS and RHS:
3869 Try to merge two comparisons to the same innermost item.
3870 Look for range tests like "ch >= '0' && ch <= '9'".
3871 Look for combinations of simple terms on machines with expensive branches
3872 and evaluate the RHS unconditionally.
3874 For example, if we have p->a == 2 && p->b == 4 and we can make an
3875 object large enough to span both A and B, we can do this with a comparison
3876 against the object ANDed with the a mask.
3878 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
3879 operations to do this with one comparison.
3881 We check for both normal comparisons and the BIT_AND_EXPRs made this by
3882 function and the one above.
3884 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
3885 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
3887 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
3890 We return the simplified tree or 0 if no optimization is possible. */
3893 fold_truthop (code, truth_type, lhs, rhs)
3894 enum tree_code code;
3895 tree truth_type, lhs, rhs;
3897 /* If this is the "or" of two comparisons, we can do something if we
3898 the comparisons are NE_EXPR. If this is the "and", we can do something
3899 if the comparisons are EQ_EXPR. I.e.,
3900 (a->b == 2 && a->c == 4) can become (a->new == NEW).
3902 WANTED_CODE is this operation code. For single bit fields, we can
3903 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
3904 comparison for one-bit fields. */
3906 enum tree_code wanted_code;
3907 enum tree_code lcode, rcode;
3908 tree ll_arg, lr_arg, rl_arg, rr_arg;
3909 tree ll_inner, lr_inner, rl_inner, rr_inner;
3910 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
3911 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
3912 HOST_WIDE_INT xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
3913 HOST_WIDE_INT lnbitsize, lnbitpos, rnbitsize, rnbitpos;
3914 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
3915 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
3916 enum machine_mode lnmode, rnmode;
3917 tree ll_mask, lr_mask, rl_mask, rr_mask;
3918 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
3919 tree l_const, r_const;
3920 tree lntype, rntype, result;
3921 int first_bit, end_bit;
3924 /* Start by getting the comparison codes. Fail if anything is volatile.
3925 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
3926 it were surrounded with a NE_EXPR. */
3928 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
3931 lcode = TREE_CODE (lhs);
3932 rcode = TREE_CODE (rhs);
3934 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
3935 lcode = NE_EXPR, lhs = build (NE_EXPR, truth_type, lhs, integer_zero_node);
3937 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
3938 rcode = NE_EXPR, rhs = build (NE_EXPR, truth_type, rhs, integer_zero_node);
3940 if (TREE_CODE_CLASS (lcode) != '<' || TREE_CODE_CLASS (rcode) != '<')
3943 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
3944 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
3946 ll_arg = TREE_OPERAND (lhs, 0);
3947 lr_arg = TREE_OPERAND (lhs, 1);
3948 rl_arg = TREE_OPERAND (rhs, 0);
3949 rr_arg = TREE_OPERAND (rhs, 1);
3951 /* If the RHS can be evaluated unconditionally and its operands are
3952 simple, it wins to evaluate the RHS unconditionally on machines
3953 with expensive branches. In this case, this isn't a comparison
3954 that can be merged. Avoid doing this if the RHS is a floating-point
3955 comparison since those can trap. */
3957 if (BRANCH_COST >= 2
3958 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
3959 && simple_operand_p (rl_arg)
3960 && simple_operand_p (rr_arg))
3961 return build (code, truth_type, lhs, rhs);
3963 /* See if the comparisons can be merged. Then get all the parameters for
3966 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
3967 || (rcode != EQ_EXPR && rcode != NE_EXPR))
3971 ll_inner = decode_field_reference (ll_arg,
3972 &ll_bitsize, &ll_bitpos, &ll_mode,
3973 &ll_unsignedp, &volatilep, &ll_mask,
3975 lr_inner = decode_field_reference (lr_arg,
3976 &lr_bitsize, &lr_bitpos, &lr_mode,
3977 &lr_unsignedp, &volatilep, &lr_mask,
3979 rl_inner = decode_field_reference (rl_arg,
3980 &rl_bitsize, &rl_bitpos, &rl_mode,
3981 &rl_unsignedp, &volatilep, &rl_mask,
3983 rr_inner = decode_field_reference (rr_arg,
3984 &rr_bitsize, &rr_bitpos, &rr_mode,
3985 &rr_unsignedp, &volatilep, &rr_mask,
3988 /* It must be true that the inner operation on the lhs of each
3989 comparison must be the same if we are to be able to do anything.
3990 Then see if we have constants. If not, the same must be true for
3992 if (volatilep || ll_inner == 0 || rl_inner == 0
3993 || ! operand_equal_p (ll_inner, rl_inner, 0))
3996 if (TREE_CODE (lr_arg) == INTEGER_CST
3997 && TREE_CODE (rr_arg) == INTEGER_CST)
3998 l_const = lr_arg, r_const = rr_arg;
3999 else if (lr_inner == 0 || rr_inner == 0
4000 || ! operand_equal_p (lr_inner, rr_inner, 0))
4003 l_const = r_const = 0;
4005 /* If either comparison code is not correct for our logical operation,
4006 fail. However, we can convert a one-bit comparison against zero into
4007 the opposite comparison against that bit being set in the field. */
4009 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
4010 if (lcode != wanted_code)
4012 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
4014 /* Make the left operand unsigned, since we are only interested
4015 in the value of one bit. Otherwise we are doing the wrong
4024 /* This is analogous to the code for l_const above. */
4025 if (rcode != wanted_code)
4027 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
4036 /* See if we can find a mode that contains both fields being compared on
4037 the left. If we can't, fail. Otherwise, update all constants and masks
4038 to be relative to a field of that size. */
4039 first_bit = MIN (ll_bitpos, rl_bitpos);
4040 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
4041 lnmode = get_best_mode (end_bit - first_bit, first_bit,
4042 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
4044 if (lnmode == VOIDmode)
4047 lnbitsize = GET_MODE_BITSIZE (lnmode);
4048 lnbitpos = first_bit & ~ (lnbitsize - 1);
4049 lntype = type_for_size (lnbitsize, 1);
4050 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
4052 if (BYTES_BIG_ENDIAN)
4054 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
4055 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
4058 ll_mask = const_binop (LSHIFT_EXPR, convert (lntype, ll_mask),
4059 size_int (xll_bitpos), 0);
4060 rl_mask = const_binop (LSHIFT_EXPR, convert (lntype, rl_mask),
4061 size_int (xrl_bitpos), 0);
4065 l_const = convert (lntype, l_const);
4066 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
4067 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
4068 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
4069 fold (build1 (BIT_NOT_EXPR,
4073 warning ("comparison is always %d", wanted_code == NE_EXPR);
4075 return convert (truth_type,
4076 wanted_code == NE_EXPR
4077 ? integer_one_node : integer_zero_node);
4082 r_const = convert (lntype, r_const);
4083 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
4084 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
4085 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
4086 fold (build1 (BIT_NOT_EXPR,
4090 warning ("comparison is always %d", wanted_code == NE_EXPR);
4092 return convert (truth_type,
4093 wanted_code == NE_EXPR
4094 ? integer_one_node : integer_zero_node);
4098 /* If the right sides are not constant, do the same for it. Also,
4099 disallow this optimization if a size or signedness mismatch occurs
4100 between the left and right sides. */
4103 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
4104 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
4105 /* Make sure the two fields on the right
4106 correspond to the left without being swapped. */
4107 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
4110 first_bit = MIN (lr_bitpos, rr_bitpos);
4111 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
4112 rnmode = get_best_mode (end_bit - first_bit, first_bit,
4113 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
4115 if (rnmode == VOIDmode)
4118 rnbitsize = GET_MODE_BITSIZE (rnmode);
4119 rnbitpos = first_bit & ~ (rnbitsize - 1);
4120 rntype = type_for_size (rnbitsize, 1);
4121 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
4123 if (BYTES_BIG_ENDIAN)
4125 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
4126 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
4129 lr_mask = const_binop (LSHIFT_EXPR, convert (rntype, lr_mask),
4130 size_int (xlr_bitpos), 0);
4131 rr_mask = const_binop (LSHIFT_EXPR, convert (rntype, rr_mask),
4132 size_int (xrr_bitpos), 0);
4134 /* Make a mask that corresponds to both fields being compared.
4135 Do this for both items being compared. If the operands are the
4136 same size and the bits being compared are in the same position
4137 then we can do this by masking both and comparing the masked
4139 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4140 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
4141 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
4143 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4144 ll_unsignedp || rl_unsignedp);
4145 if (! all_ones_mask_p (ll_mask, lnbitsize))
4146 lhs = build (BIT_AND_EXPR, lntype, lhs, ll_mask);
4148 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
4149 lr_unsignedp || rr_unsignedp);
4150 if (! all_ones_mask_p (lr_mask, rnbitsize))
4151 rhs = build (BIT_AND_EXPR, rntype, rhs, lr_mask);
4153 return build (wanted_code, truth_type, lhs, rhs);
4156 /* There is still another way we can do something: If both pairs of
4157 fields being compared are adjacent, we may be able to make a wider
4158 field containing them both.
4160 Note that we still must mask the lhs/rhs expressions. Furthermore,
4161 the mask must be shifted to account for the shift done by
4162 make_bit_field_ref. */
4163 if ((ll_bitsize + ll_bitpos == rl_bitpos
4164 && lr_bitsize + lr_bitpos == rr_bitpos)
4165 || (ll_bitpos == rl_bitpos + rl_bitsize
4166 && lr_bitpos == rr_bitpos + rr_bitsize))
4170 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
4171 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
4172 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
4173 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
4175 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
4176 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
4177 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
4178 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
4180 /* Convert to the smaller type before masking out unwanted bits. */
4182 if (lntype != rntype)
4184 if (lnbitsize > rnbitsize)
4186 lhs = convert (rntype, lhs);
4187 ll_mask = convert (rntype, ll_mask);
4190 else if (lnbitsize < rnbitsize)
4192 rhs = convert (lntype, rhs);
4193 lr_mask = convert (lntype, lr_mask);
4198 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
4199 lhs = build (BIT_AND_EXPR, type, lhs, ll_mask);
4201 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
4202 rhs = build (BIT_AND_EXPR, type, rhs, lr_mask);
4204 return build (wanted_code, truth_type, lhs, rhs);
4210 /* Handle the case of comparisons with constants. If there is something in
4211 common between the masks, those bits of the constants must be the same.
4212 If not, the condition is always false. Test for this to avoid generating
4213 incorrect code below. */
4214 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
4215 if (! integer_zerop (result)
4216 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
4217 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
4219 if (wanted_code == NE_EXPR)
4221 warning ("`or' of unmatched not-equal tests is always 1");
4222 return convert (truth_type, integer_one_node);
4226 warning ("`and' of mutually exclusive equal-tests is always 0");
4227 return convert (truth_type, integer_zero_node);
4231 /* Construct the expression we will return. First get the component
4232 reference we will make. Unless the mask is all ones the width of
4233 that field, perform the mask operation. Then compare with the
4235 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4236 ll_unsignedp || rl_unsignedp);
4238 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4239 if (! all_ones_mask_p (ll_mask, lnbitsize))
4240 result = build (BIT_AND_EXPR, lntype, result, ll_mask);
4242 return build (wanted_code, truth_type, result,
4243 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
4246 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
4250 optimize_minmax_comparison (t)
4253 tree type = TREE_TYPE (t);
4254 tree arg0 = TREE_OPERAND (t, 0);
4255 enum tree_code op_code;
4256 tree comp_const = TREE_OPERAND (t, 1);
4258 int consts_equal, consts_lt;
4261 STRIP_SIGN_NOPS (arg0);
4263 op_code = TREE_CODE (arg0);
4264 minmax_const = TREE_OPERAND (arg0, 1);
4265 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
4266 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
4267 inner = TREE_OPERAND (arg0, 0);
4269 /* If something does not permit us to optimize, return the original tree. */
4270 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
4271 || TREE_CODE (comp_const) != INTEGER_CST
4272 || TREE_CONSTANT_OVERFLOW (comp_const)
4273 || TREE_CODE (minmax_const) != INTEGER_CST
4274 || TREE_CONSTANT_OVERFLOW (minmax_const))
4277 /* Now handle all the various comparison codes. We only handle EQ_EXPR
4278 and GT_EXPR, doing the rest with recursive calls using logical
4280 switch (TREE_CODE (t))
4282 case NE_EXPR: case LT_EXPR: case LE_EXPR:
4284 invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t)));
4288 fold (build (TRUTH_ORIF_EXPR, type,
4289 optimize_minmax_comparison
4290 (build (EQ_EXPR, type, arg0, comp_const)),
4291 optimize_minmax_comparison
4292 (build (GT_EXPR, type, arg0, comp_const))));
4295 if (op_code == MAX_EXPR && consts_equal)
4296 /* MAX (X, 0) == 0 -> X <= 0 */
4297 return fold (build (LE_EXPR, type, inner, comp_const));
4299 else if (op_code == MAX_EXPR && consts_lt)
4300 /* MAX (X, 0) == 5 -> X == 5 */
4301 return fold (build (EQ_EXPR, type, inner, comp_const));
4303 else if (op_code == MAX_EXPR)
4304 /* MAX (X, 0) == -1 -> false */
4305 return omit_one_operand (type, integer_zero_node, inner);
4307 else if (consts_equal)
4308 /* MIN (X, 0) == 0 -> X >= 0 */
4309 return fold (build (GE_EXPR, type, inner, comp_const));
4312 /* MIN (X, 0) == 5 -> false */
4313 return omit_one_operand (type, integer_zero_node, inner);
4316 /* MIN (X, 0) == -1 -> X == -1 */
4317 return fold (build (EQ_EXPR, type, inner, comp_const));
4320 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
4321 /* MAX (X, 0) > 0 -> X > 0
4322 MAX (X, 0) > 5 -> X > 5 */
4323 return fold (build (GT_EXPR, type, inner, comp_const));
4325 else if (op_code == MAX_EXPR)
4326 /* MAX (X, 0) > -1 -> true */
4327 return omit_one_operand (type, integer_one_node, inner);
4329 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
4330 /* MIN (X, 0) > 0 -> false
4331 MIN (X, 0) > 5 -> false */
4332 return omit_one_operand (type, integer_zero_node, inner);
4335 /* MIN (X, 0) > -1 -> X > -1 */
4336 return fold (build (GT_EXPR, type, inner, comp_const));
4343 /* T is an integer expression that is being multiplied, divided, or taken a
4344 modulus (CODE says which and what kind of divide or modulus) by a
4345 constant C. See if we can eliminate that operation by folding it with
4346 other operations already in T. WIDE_TYPE, if non-null, is a type that
4347 should be used for the computation if wider than our type.
4349 For example, if we are dividing (X * 8) + (Y + 16) by 4, we can return
4350 (X * 2) + (Y + 4). We must, however, be assured that either the original
4351 expression would not overflow or that overflow is undefined for the type
4352 in the language in question.
4354 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
4355 the machine has a multiply-accumulate insn or that this is part of an
4356 addressing calculation.
4358 If we return a non-null expression, it is an equivalent form of the
4359 original computation, but need not be in the original type. */
4362 extract_muldiv (t, c, code, wide_type)
4365 enum tree_code code;
4368 tree type = TREE_TYPE (t);
4369 enum tree_code tcode = TREE_CODE (t);
4370 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
4371 > GET_MODE_SIZE (TYPE_MODE (type)))
4372 ? wide_type : type);
4374 int same_p = tcode == code;
4375 tree op0 = NULL_TREE, op1 = NULL_TREE;
4377 /* Don't deal with constants of zero here; they confuse the code below. */
4378 if (integer_zerop (c))
4381 if (TREE_CODE_CLASS (tcode) == '1')
4382 op0 = TREE_OPERAND (t, 0);
4384 if (TREE_CODE_CLASS (tcode) == '2')
4385 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
4387 /* Note that we need not handle conditional operations here since fold
4388 already handles those cases. So just do arithmetic here. */
4392 /* For a constant, we can always simplify if we are a multiply
4393 or (for divide and modulus) if it is a multiple of our constant. */
4394 if (code == MULT_EXPR
4395 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
4396 return const_binop (code, convert (ctype, t), convert (ctype, c), 0);
4399 case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
4400 /* If op0 is an expression, and is unsigned, and the type is
4401 smaller than ctype, then we cannot widen the expression. */
4402 if ((TREE_CODE_CLASS (TREE_CODE (op0)) == '<'
4403 || TREE_CODE_CLASS (TREE_CODE (op0)) == '1'
4404 || TREE_CODE_CLASS (TREE_CODE (op0)) == '2'
4405 || TREE_CODE_CLASS (TREE_CODE (op0)) == 'e')
4406 && TREE_UNSIGNED (TREE_TYPE (op0))
4407 && ! TYPE_IS_SIZETYPE (TREE_TYPE (op0))
4408 && (GET_MODE_SIZE (TYPE_MODE (ctype))
4409 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
4412 /* Pass the constant down and see if we can make a simplification. If
4413 we can, replace this expression with the inner simplification for
4414 possible later conversion to our or some other type. */
4415 if (0 != (t1 = extract_muldiv (op0, convert (TREE_TYPE (op0), c), code,
4416 code == MULT_EXPR ? ctype : NULL_TREE)))
4420 case NEGATE_EXPR: case ABS_EXPR:
4421 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4422 return fold (build1 (tcode, ctype, convert (ctype, t1)));
4425 case MIN_EXPR: case MAX_EXPR:
4426 /* If widening the type changes the signedness, then we can't perform
4427 this optimization as that changes the result. */
4428 if (TREE_UNSIGNED (ctype) != TREE_UNSIGNED (type))
4431 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
4432 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0
4433 && (t2 = extract_muldiv (op1, c, code, wide_type)) != 0)
4435 if (tree_int_cst_sgn (c) < 0)
4436 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
4438 return fold (build (tcode, ctype, convert (ctype, t1),
4439 convert (ctype, t2)));
4443 case WITH_RECORD_EXPR:
4444 if ((t1 = extract_muldiv (TREE_OPERAND (t, 0), c, code, wide_type)) != 0)
4445 return build (WITH_RECORD_EXPR, TREE_TYPE (t1), t1,
4446 TREE_OPERAND (t, 1));
4450 /* If this has not been evaluated and the operand has no side effects,
4451 we can see if we can do something inside it and make a new one.
4452 Note that this test is overly conservative since we can do this
4453 if the only reason it had side effects is that it was another
4454 similar SAVE_EXPR, but that isn't worth bothering with. */
4455 if (SAVE_EXPR_RTL (t) == 0 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0))
4456 && 0 != (t1 = extract_muldiv (TREE_OPERAND (t, 0), c, code,
4458 return save_expr (t1);
4461 case LSHIFT_EXPR: case RSHIFT_EXPR:
4462 /* If the second operand is constant, this is a multiplication
4463 or floor division, by a power of two, so we can treat it that
4464 way unless the multiplier or divisor overflows. */
4465 if (TREE_CODE (op1) == INTEGER_CST
4466 /* const_binop may not detect overflow correctly,
4467 so check for it explicitly here. */
4468 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
4469 && TREE_INT_CST_HIGH (op1) == 0
4470 && 0 != (t1 = convert (ctype,
4471 const_binop (LSHIFT_EXPR, size_one_node,
4473 && ! TREE_OVERFLOW (t1))
4474 return extract_muldiv (build (tcode == LSHIFT_EXPR
4475 ? MULT_EXPR : FLOOR_DIV_EXPR,
4476 ctype, convert (ctype, op0), t1),
4477 c, code, wide_type);
4480 case PLUS_EXPR: case MINUS_EXPR:
4481 /* See if we can eliminate the operation on both sides. If we can, we
4482 can return a new PLUS or MINUS. If we can't, the only remaining
4483 cases where we can do anything are if the second operand is a
4485 t1 = extract_muldiv (op0, c, code, wide_type);
4486 t2 = extract_muldiv (op1, c, code, wide_type);
4487 if (t1 != 0 && t2 != 0)
4488 return fold (build (tcode, ctype, convert (ctype, t1),
4489 convert (ctype, t2)));
4491 /* If this was a subtraction, negate OP1 and set it to be an addition.
4492 This simplifies the logic below. */
4493 if (tcode == MINUS_EXPR)
4494 tcode = PLUS_EXPR, op1 = negate_expr (op1);
4496 if (TREE_CODE (op1) != INTEGER_CST)
4499 /* If either OP1 or C are negative, this optimization is not safe for
4500 some of the division and remainder types while for others we need
4501 to change the code. */
4502 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
4504 if (code == CEIL_DIV_EXPR)
4505 code = FLOOR_DIV_EXPR;
4506 else if (code == CEIL_MOD_EXPR)
4507 code = FLOOR_MOD_EXPR;
4508 else if (code == FLOOR_DIV_EXPR)
4509 code = CEIL_DIV_EXPR;
4510 else if (code == FLOOR_MOD_EXPR)
4511 code = CEIL_MOD_EXPR;
4512 else if (code != MULT_EXPR)
4516 /* If it's a multiply or a division/modulus operation of a multiple
4517 of our constant, do the operation and verify it doesn't overflow. */
4518 if (code == MULT_EXPR
4519 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4521 op1 = const_binop (code, convert (ctype, op1), convert (ctype, c), 0);
4522 if (op1 == 0 || TREE_OVERFLOW (op1))
4528 /* If we have an unsigned type is not a sizetype, we cannot widen
4529 the operation since it will change the result if the original
4530 computation overflowed. */
4531 if (TREE_UNSIGNED (ctype)
4532 && ! TYPE_IS_SIZETYPE (ctype)
4536 /* If we were able to eliminate our operation from the first side,
4537 apply our operation to the second side and reform the PLUS. */
4538 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
4539 return fold (build (tcode, ctype, convert (ctype, t1), op1));
4541 /* The last case is if we are a multiply. In that case, we can
4542 apply the distributive law to commute the multiply and addition
4543 if the multiplication of the constants doesn't overflow. */
4544 if (code == MULT_EXPR)
4545 return fold (build (tcode, ctype, fold (build (code, ctype,
4546 convert (ctype, op0),
4547 convert (ctype, c))),
4553 /* We have a special case here if we are doing something like
4554 (C * 8) % 4 since we know that's zero. */
4555 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
4556 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
4557 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
4558 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4559 return omit_one_operand (type, integer_zero_node, op0);
4561 /* ... fall through ... */
4563 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
4564 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
4565 /* If we can extract our operation from the LHS, do so and return a
4566 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
4567 do something only if the second operand is a constant. */
4569 && (t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4570 return fold (build (tcode, ctype, convert (ctype, t1),
4571 convert (ctype, op1)));
4572 else if (tcode == MULT_EXPR && code == MULT_EXPR
4573 && (t1 = extract_muldiv (op1, c, code, wide_type)) != 0)
4574 return fold (build (tcode, ctype, convert (ctype, op0),
4575 convert (ctype, t1)));
4576 else if (TREE_CODE (op1) != INTEGER_CST)
4579 /* If these are the same operation types, we can associate them
4580 assuming no overflow. */
4582 && 0 != (t1 = const_binop (MULT_EXPR, convert (ctype, op1),
4583 convert (ctype, c), 0))
4584 && ! TREE_OVERFLOW (t1))
4585 return fold (build (tcode, ctype, convert (ctype, op0), t1));
4587 /* If these operations "cancel" each other, we have the main
4588 optimizations of this pass, which occur when either constant is a
4589 multiple of the other, in which case we replace this with either an
4590 operation or CODE or TCODE.
4592 If we have an unsigned type that is not a sizetype, we canot do
4593 this since it will change the result if the original computation
4595 if ((! TREE_UNSIGNED (ctype)
4596 || TYPE_IS_SIZETYPE (ctype))
4597 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
4598 || (tcode == MULT_EXPR
4599 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
4600 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR)))
4602 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4603 return fold (build (tcode, ctype, convert (ctype, op0),
4605 const_binop (TRUNC_DIV_EXPR,
4607 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
4608 return fold (build (code, ctype, convert (ctype, op0),
4610 const_binop (TRUNC_DIV_EXPR,
4622 /* If T contains a COMPOUND_EXPR which was inserted merely to evaluate
4623 S, a SAVE_EXPR, return the expression actually being evaluated. Note
4624 that we may sometimes modify the tree. */
4627 strip_compound_expr (t, s)
4631 enum tree_code code = TREE_CODE (t);
4633 /* See if this is the COMPOUND_EXPR we want to eliminate. */
4634 if (code == COMPOUND_EXPR && TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR
4635 && TREE_OPERAND (TREE_OPERAND (t, 0), 0) == s)
4636 return TREE_OPERAND (t, 1);
4638 /* See if this is a COND_EXPR or a simple arithmetic operator. We
4639 don't bother handling any other types. */
4640 else if (code == COND_EXPR)
4642 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4643 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4644 TREE_OPERAND (t, 2) = strip_compound_expr (TREE_OPERAND (t, 2), s);
4646 else if (TREE_CODE_CLASS (code) == '1')
4647 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4648 else if (TREE_CODE_CLASS (code) == '<'
4649 || TREE_CODE_CLASS (code) == '2')
4651 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4652 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4658 /* Return a node which has the indicated constant VALUE (either 0 or
4659 1), and is of the indicated TYPE. */
4662 constant_boolean_node (value, type)
4666 if (type == integer_type_node)
4667 return value ? integer_one_node : integer_zero_node;
4668 else if (TREE_CODE (type) == BOOLEAN_TYPE)
4669 return truthvalue_conversion (value ? integer_one_node :
4673 tree t = build_int_2 (value, 0);
4675 TREE_TYPE (t) = type;
4680 /* Utility function for the following routine, to see how complex a nesting of
4681 COND_EXPRs can be. EXPR is the expression and LIMIT is a count beyond which
4682 we don't care (to avoid spending too much time on complex expressions.). */
4685 count_cond (expr, lim)
4691 if (TREE_CODE (expr) != COND_EXPR)
4696 true = count_cond (TREE_OPERAND (expr, 1), lim - 1);
4697 false = count_cond (TREE_OPERAND (expr, 2), lim - 1 - true);
4698 return MIN (lim, 1 + true + false);
4701 /* Perform constant folding and related simplification of EXPR.
4702 The related simplifications include x*1 => x, x*0 => 0, etc.,
4703 and application of the associative law.
4704 NOP_EXPR conversions may be removed freely (as long as we
4705 are careful not to change the C type of the overall expression)
4706 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
4707 but we can constant-fold them if they have constant operands. */
4713 register tree t = expr;
4714 tree t1 = NULL_TREE;
4716 tree type = TREE_TYPE (expr);
4717 register tree arg0 = NULL_TREE, arg1 = NULL_TREE;
4718 register enum tree_code code = TREE_CODE (t);
4721 /* WINS will be nonzero when the switch is done
4722 if all operands are constant. */
4725 /* Don't try to process an RTL_EXPR since its operands aren't trees.
4726 Likewise for a SAVE_EXPR that's already been evaluated. */
4727 if (code == RTL_EXPR || (code == SAVE_EXPR && SAVE_EXPR_RTL (t)) != 0)
4730 /* Return right away if already constant. */
4731 if (TREE_CONSTANT (t))
4733 if (code == CONST_DECL)
4734 return DECL_INITIAL (t);
4738 #ifdef MAX_INTEGER_COMPUTATION_MODE
4739 check_max_integer_computation_mode (expr);
4742 kind = TREE_CODE_CLASS (code);
4743 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
4747 /* Special case for conversion ops that can have fixed point args. */
4748 arg0 = TREE_OPERAND (t, 0);
4750 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
4752 STRIP_SIGN_NOPS (arg0);
4754 if (arg0 != 0 && TREE_CODE (arg0) == COMPLEX_CST)
4755 subop = TREE_REALPART (arg0);
4759 if (subop != 0 && TREE_CODE (subop) != INTEGER_CST
4760 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
4761 && TREE_CODE (subop) != REAL_CST
4762 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
4764 /* Note that TREE_CONSTANT isn't enough:
4765 static var addresses are constant but we can't
4766 do arithmetic on them. */
4769 else if (IS_EXPR_CODE_CLASS (kind) || kind == 'r')
4771 register int len = TREE_CODE_LENGTH (code);
4773 for (i = 0; i < len; i++)
4775 tree op = TREE_OPERAND (t, i);
4779 continue; /* Valid for CALL_EXPR, at least. */
4781 if (kind == '<' || code == RSHIFT_EXPR)
4783 /* Signedness matters here. Perhaps we can refine this
4785 STRIP_SIGN_NOPS (op);
4788 /* Strip any conversions that don't change the mode. */
4791 if (TREE_CODE (op) == COMPLEX_CST)
4792 subop = TREE_REALPART (op);
4796 if (TREE_CODE (subop) != INTEGER_CST
4797 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
4798 && TREE_CODE (subop) != REAL_CST
4799 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
4801 /* Note that TREE_CONSTANT isn't enough:
4802 static var addresses are constant but we can't
4803 do arithmetic on them. */
4813 /* If this is a commutative operation, and ARG0 is a constant, move it
4814 to ARG1 to reduce the number of tests below. */
4815 if ((code == PLUS_EXPR || code == MULT_EXPR || code == MIN_EXPR
4816 || code == MAX_EXPR || code == BIT_IOR_EXPR || code == BIT_XOR_EXPR
4817 || code == BIT_AND_EXPR)
4818 && (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST))
4820 tem = arg0; arg0 = arg1; arg1 = tem;
4822 tem = TREE_OPERAND (t, 0); TREE_OPERAND (t, 0) = TREE_OPERAND (t, 1);
4823 TREE_OPERAND (t, 1) = tem;
4826 /* Now WINS is set as described above,
4827 ARG0 is the first operand of EXPR,
4828 and ARG1 is the second operand (if it has more than one operand).
4830 First check for cases where an arithmetic operation is applied to a
4831 compound, conditional, or comparison operation. Push the arithmetic
4832 operation inside the compound or conditional to see if any folding
4833 can then be done. Convert comparison to conditional for this purpose.
4834 The also optimizes non-constant cases that used to be done in
4837 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
4838 one of the operands is a comparison and the other is a comparison, a
4839 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
4840 code below would make the expression more complex. Change it to a
4841 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
4842 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
4844 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
4845 || code == EQ_EXPR || code == NE_EXPR)
4846 && ((truth_value_p (TREE_CODE (arg0))
4847 && (truth_value_p (TREE_CODE (arg1))
4848 || (TREE_CODE (arg1) == BIT_AND_EXPR
4849 && integer_onep (TREE_OPERAND (arg1, 1)))))
4850 || (truth_value_p (TREE_CODE (arg1))
4851 && (truth_value_p (TREE_CODE (arg0))
4852 || (TREE_CODE (arg0) == BIT_AND_EXPR
4853 && integer_onep (TREE_OPERAND (arg0, 1)))))))
4855 t = fold (build (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
4856 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
4860 if (code == EQ_EXPR)
4861 t = invert_truthvalue (t);
4866 if (TREE_CODE_CLASS (code) == '1')
4868 if (TREE_CODE (arg0) == COMPOUND_EXPR)
4869 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
4870 fold (build1 (code, type, TREE_OPERAND (arg0, 1))));
4871 else if (TREE_CODE (arg0) == COND_EXPR)
4873 t = fold (build (COND_EXPR, type, TREE_OPERAND (arg0, 0),
4874 fold (build1 (code, type, TREE_OPERAND (arg0, 1))),
4875 fold (build1 (code, type, TREE_OPERAND (arg0, 2)))));
4877 /* If this was a conversion, and all we did was to move into
4878 inside the COND_EXPR, bring it back out. But leave it if
4879 it is a conversion from integer to integer and the
4880 result precision is no wider than a word since such a
4881 conversion is cheap and may be optimized away by combine,
4882 while it couldn't if it were outside the COND_EXPR. Then return
4883 so we don't get into an infinite recursion loop taking the
4884 conversion out and then back in. */
4886 if ((code == NOP_EXPR || code == CONVERT_EXPR
4887 || code == NON_LVALUE_EXPR)
4888 && TREE_CODE (t) == COND_EXPR
4889 && TREE_CODE (TREE_OPERAND (t, 1)) == code
4890 && TREE_CODE (TREE_OPERAND (t, 2)) == code
4891 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))
4892 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 2), 0)))
4893 && ! (INTEGRAL_TYPE_P (TREE_TYPE (t))
4895 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))))
4896 && TYPE_PRECISION (TREE_TYPE (t)) <= BITS_PER_WORD))
4897 t = build1 (code, type,
4899 TREE_TYPE (TREE_OPERAND
4900 (TREE_OPERAND (t, 1), 0)),
4901 TREE_OPERAND (t, 0),
4902 TREE_OPERAND (TREE_OPERAND (t, 1), 0),
4903 TREE_OPERAND (TREE_OPERAND (t, 2), 0)));
4906 else if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<')
4907 return fold (build (COND_EXPR, type, arg0,
4908 fold (build1 (code, type, integer_one_node)),
4909 fold (build1 (code, type, integer_zero_node))));
4911 else if (TREE_CODE_CLASS (code) == '2'
4912 || TREE_CODE_CLASS (code) == '<')
4914 if (TREE_CODE (arg1) == COMPOUND_EXPR)
4915 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
4916 fold (build (code, type,
4917 arg0, TREE_OPERAND (arg1, 1))));
4918 else if ((TREE_CODE (arg1) == COND_EXPR
4919 || (TREE_CODE_CLASS (TREE_CODE (arg1)) == '<'
4920 && TREE_CODE_CLASS (code) != '<'))
4921 && (TREE_CODE (arg0) != COND_EXPR
4922 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
4923 && (! TREE_SIDE_EFFECTS (arg0)
4924 || (global_bindings_p () == 0
4925 && ! contains_placeholder_p (arg0))))
4927 tree test, true_value, false_value;
4928 tree lhs = 0, rhs = 0;
4930 if (TREE_CODE (arg1) == COND_EXPR)
4932 test = TREE_OPERAND (arg1, 0);
4933 true_value = TREE_OPERAND (arg1, 1);
4934 false_value = TREE_OPERAND (arg1, 2);
4938 tree testtype = TREE_TYPE (arg1);
4940 true_value = convert (testtype, integer_one_node);
4941 false_value = convert (testtype, integer_zero_node);
4944 /* If ARG0 is complex we want to make sure we only evaluate
4945 it once. Though this is only required if it is volatile, it
4946 might be more efficient even if it is not. However, if we
4947 succeed in folding one part to a constant, we do not need
4948 to make this SAVE_EXPR. Since we do this optimization
4949 primarily to see if we do end up with constant and this
4950 SAVE_EXPR interferes with later optimizations, suppressing
4951 it when we can is important.
4953 If we are not in a function, we can't make a SAVE_EXPR, so don't
4954 try to do so. Don't try to see if the result is a constant
4955 if an arm is a COND_EXPR since we get exponential behavior
4958 if (TREE_CODE (arg0) != SAVE_EXPR && ! TREE_CONSTANT (arg0)
4959 && global_bindings_p () == 0
4960 && ((TREE_CODE (arg0) != VAR_DECL
4961 && TREE_CODE (arg0) != PARM_DECL)
4962 || TREE_SIDE_EFFECTS (arg0)))
4964 if (TREE_CODE (true_value) != COND_EXPR)
4965 lhs = fold (build (code, type, arg0, true_value));
4967 if (TREE_CODE (false_value) != COND_EXPR)
4968 rhs = fold (build (code, type, arg0, false_value));
4970 if ((lhs == 0 || ! TREE_CONSTANT (lhs))
4971 && (rhs == 0 || !TREE_CONSTANT (rhs)))
4972 arg0 = save_expr (arg0), lhs = rhs = 0;
4976 lhs = fold (build (code, type, arg0, true_value));
4978 rhs = fold (build (code, type, arg0, false_value));
4980 test = fold (build (COND_EXPR, type, test, lhs, rhs));
4982 if (TREE_CODE (arg0) == SAVE_EXPR)
4983 return build (COMPOUND_EXPR, type,
4984 convert (void_type_node, arg0),
4985 strip_compound_expr (test, arg0));
4987 return convert (type, test);
4990 else if (TREE_CODE (arg0) == COMPOUND_EXPR)
4991 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
4992 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
4993 else if ((TREE_CODE (arg0) == COND_EXPR
4994 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
4995 && TREE_CODE_CLASS (code) != '<'))
4996 && (TREE_CODE (arg1) != COND_EXPR
4997 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
4998 && (! TREE_SIDE_EFFECTS (arg1)
4999 || (global_bindings_p () == 0
5000 && ! contains_placeholder_p (arg1))))
5002 tree test, true_value, false_value;
5003 tree lhs = 0, rhs = 0;
5005 if (TREE_CODE (arg0) == COND_EXPR)
5007 test = TREE_OPERAND (arg0, 0);
5008 true_value = TREE_OPERAND (arg0, 1);
5009 false_value = TREE_OPERAND (arg0, 2);
5013 tree testtype = TREE_TYPE (arg0);
5015 true_value = convert (testtype, integer_one_node);
5016 false_value = convert (testtype, integer_zero_node);
5019 if (TREE_CODE (arg1) != SAVE_EXPR && ! TREE_CONSTANT (arg0)
5020 && global_bindings_p () == 0
5021 && ((TREE_CODE (arg1) != VAR_DECL
5022 && TREE_CODE (arg1) != PARM_DECL)
5023 || TREE_SIDE_EFFECTS (arg1)))
5025 if (TREE_CODE (true_value) != COND_EXPR)
5026 lhs = fold (build (code, type, true_value, arg1));
5028 if (TREE_CODE (false_value) != COND_EXPR)
5029 rhs = fold (build (code, type, false_value, arg1));
5031 if ((lhs == 0 || ! TREE_CONSTANT (lhs))
5032 && (rhs == 0 || !TREE_CONSTANT (rhs)))
5033 arg1 = save_expr (arg1), lhs = rhs = 0;
5037 lhs = fold (build (code, type, true_value, arg1));
5040 rhs = fold (build (code, type, false_value, arg1));
5042 test = fold (build (COND_EXPR, type, test, lhs, rhs));
5043 if (TREE_CODE (arg1) == SAVE_EXPR)
5044 return build (COMPOUND_EXPR, type,
5045 convert (void_type_node, arg1),
5046 strip_compound_expr (test, arg1));
5048 return convert (type, test);
5051 else if (TREE_CODE_CLASS (code) == '<'
5052 && TREE_CODE (arg0) == COMPOUND_EXPR)
5053 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5054 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
5055 else if (TREE_CODE_CLASS (code) == '<'
5056 && TREE_CODE (arg1) == COMPOUND_EXPR)
5057 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
5058 fold (build (code, type, arg0, TREE_OPERAND (arg1, 1))));
5070 return fold (DECL_INITIAL (t));
5075 case FIX_TRUNC_EXPR:
5076 /* Other kinds of FIX are not handled properly by fold_convert. */
5078 if (TREE_TYPE (TREE_OPERAND (t, 0)) == TREE_TYPE (t))
5079 return TREE_OPERAND (t, 0);
5081 /* Handle cases of two conversions in a row. */
5082 if (TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
5083 || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR)
5085 tree inside_type = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5086 tree inter_type = TREE_TYPE (TREE_OPERAND (t, 0));
5087 tree final_type = TREE_TYPE (t);
5088 int inside_int = INTEGRAL_TYPE_P (inside_type);
5089 int inside_ptr = POINTER_TYPE_P (inside_type);
5090 int inside_float = FLOAT_TYPE_P (inside_type);
5091 unsigned int inside_prec = TYPE_PRECISION (inside_type);
5092 int inside_unsignedp = TREE_UNSIGNED (inside_type);
5093 int inter_int = INTEGRAL_TYPE_P (inter_type);
5094 int inter_ptr = POINTER_TYPE_P (inter_type);
5095 int inter_float = FLOAT_TYPE_P (inter_type);
5096 unsigned int inter_prec = TYPE_PRECISION (inter_type);
5097 int inter_unsignedp = TREE_UNSIGNED (inter_type);
5098 int final_int = INTEGRAL_TYPE_P (final_type);
5099 int final_ptr = POINTER_TYPE_P (final_type);
5100 int final_float = FLOAT_TYPE_P (final_type);
5101 unsigned int final_prec = TYPE_PRECISION (final_type);
5102 int final_unsignedp = TREE_UNSIGNED (final_type);
5104 /* In addition to the cases of two conversions in a row
5105 handled below, if we are converting something to its own
5106 type via an object of identical or wider precision, neither
5107 conversion is needed. */
5108 if (inside_type == final_type
5109 && ((inter_int && final_int) || (inter_float && final_float))
5110 && inter_prec >= final_prec)
5111 return TREE_OPERAND (TREE_OPERAND (t, 0), 0);
5113 /* Likewise, if the intermediate and final types are either both
5114 float or both integer, we don't need the middle conversion if
5115 it is wider than the final type and doesn't change the signedness
5116 (for integers). Avoid this if the final type is a pointer
5117 since then we sometimes need the inner conversion. Likewise if
5118 the outer has a precision not equal to the size of its mode. */
5119 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
5120 || (inter_float && inside_float))
5121 && inter_prec >= inside_prec
5122 && (inter_float || inter_unsignedp == inside_unsignedp)
5123 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
5124 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
5126 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5128 /* If we have a sign-extension of a zero-extended value, we can
5129 replace that by a single zero-extension. */
5130 if (inside_int && inter_int && final_int
5131 && inside_prec < inter_prec && inter_prec < final_prec
5132 && inside_unsignedp && !inter_unsignedp)
5133 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5135 /* Two conversions in a row are not needed unless:
5136 - some conversion is floating-point (overstrict for now), or
5137 - the intermediate type is narrower than both initial and
5139 - the intermediate type and innermost type differ in signedness,
5140 and the outermost type is wider than the intermediate, or
5141 - the initial type is a pointer type and the precisions of the
5142 intermediate and final types differ, or
5143 - the final type is a pointer type and the precisions of the
5144 initial and intermediate types differ. */
5145 if (! inside_float && ! inter_float && ! final_float
5146 && (inter_prec > inside_prec || inter_prec > final_prec)
5147 && ! (inside_int && inter_int
5148 && inter_unsignedp != inside_unsignedp
5149 && inter_prec < final_prec)
5150 && ((inter_unsignedp && inter_prec > inside_prec)
5151 == (final_unsignedp && final_prec > inter_prec))
5152 && ! (inside_ptr && inter_prec != final_prec)
5153 && ! (final_ptr && inside_prec != inter_prec)
5154 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
5155 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
5157 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5160 if (TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR
5161 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t, 0), 1))
5162 /* Detect assigning a bitfield. */
5163 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) == COMPONENT_REF
5164 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 1))))
5166 /* Don't leave an assignment inside a conversion
5167 unless assigning a bitfield. */
5168 tree prev = TREE_OPERAND (t, 0);
5169 TREE_OPERAND (t, 0) = TREE_OPERAND (prev, 1);
5170 /* First do the assignment, then return converted constant. */
5171 t = build (COMPOUND_EXPR, TREE_TYPE (t), prev, fold (t));
5177 TREE_CONSTANT (t) = TREE_CONSTANT (arg0);
5180 return fold_convert (t, arg0);
5182 #if 0 /* This loses on &"foo"[0]. */
5187 /* Fold an expression like: "foo"[2] */
5188 if (TREE_CODE (arg0) == STRING_CST
5189 && TREE_CODE (arg1) == INTEGER_CST
5190 && compare_tree_int (arg1, TREE_STRING_LENGTH (arg0)) < 0)
5192 t = build_int_2 (TREE_STRING_POINTER (arg0)[TREE_INT_CST_LOW (arg))], 0);
5193 TREE_TYPE (t) = TREE_TYPE (TREE_TYPE (arg0));
5194 force_fit_type (t, 0);
5201 if (TREE_CODE (arg0) == CONSTRUCTOR)
5203 tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0));
5210 TREE_CONSTANT (t) = wins;
5216 if (TREE_CODE (arg0) == INTEGER_CST)
5218 unsigned HOST_WIDE_INT low;
5220 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
5221 TREE_INT_CST_HIGH (arg0),
5223 t = build_int_2 (low, high);
5224 TREE_TYPE (t) = type;
5226 = (TREE_OVERFLOW (arg0)
5227 | force_fit_type (t, overflow && !TREE_UNSIGNED (type)));
5228 TREE_CONSTANT_OVERFLOW (t)
5229 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
5231 else if (TREE_CODE (arg0) == REAL_CST)
5232 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
5234 else if (TREE_CODE (arg0) == NEGATE_EXPR)
5235 return TREE_OPERAND (arg0, 0);
5237 /* Convert - (a - b) to (b - a) for non-floating-point. */
5238 else if (TREE_CODE (arg0) == MINUS_EXPR
5239 && (! FLOAT_TYPE_P (type) || flag_fast_math))
5240 return build (MINUS_EXPR, type, TREE_OPERAND (arg0, 1),
5241 TREE_OPERAND (arg0, 0));
5248 if (TREE_CODE (arg0) == INTEGER_CST)
5250 if (! TREE_UNSIGNED (type)
5251 && TREE_INT_CST_HIGH (arg0) < 0)
5253 unsigned HOST_WIDE_INT low;
5255 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
5256 TREE_INT_CST_HIGH (arg0),
5258 t = build_int_2 (low, high);
5259 TREE_TYPE (t) = type;
5261 = (TREE_OVERFLOW (arg0)
5262 | force_fit_type (t, overflow));
5263 TREE_CONSTANT_OVERFLOW (t)
5264 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
5267 else if (TREE_CODE (arg0) == REAL_CST)
5269 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
5270 t = build_real (type,
5271 REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
5274 else if (TREE_CODE (arg0) == ABS_EXPR || TREE_CODE (arg0) == NEGATE_EXPR)
5275 return build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0));
5279 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
5280 return convert (type, arg0);
5281 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
5282 return build (COMPLEX_EXPR, type,
5283 TREE_OPERAND (arg0, 0),
5284 negate_expr (TREE_OPERAND (arg0, 1)));
5285 else if (TREE_CODE (arg0) == COMPLEX_CST)
5286 return build_complex (type, TREE_OPERAND (arg0, 0),
5287 negate_expr (TREE_OPERAND (arg0, 1)));
5288 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
5289 return fold (build (TREE_CODE (arg0), type,
5290 fold (build1 (CONJ_EXPR, type,
5291 TREE_OPERAND (arg0, 0))),
5292 fold (build1 (CONJ_EXPR,
5293 type, TREE_OPERAND (arg0, 1)))));
5294 else if (TREE_CODE (arg0) == CONJ_EXPR)
5295 return TREE_OPERAND (arg0, 0);
5301 t = build_int_2 (~ TREE_INT_CST_LOW (arg0),
5302 ~ TREE_INT_CST_HIGH (arg0));
5303 TREE_TYPE (t) = type;
5304 force_fit_type (t, 0);
5305 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg0);
5306 TREE_CONSTANT_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (arg0);
5308 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
5309 return TREE_OPERAND (arg0, 0);
5313 /* A + (-B) -> A - B */
5314 if (TREE_CODE (arg1) == NEGATE_EXPR)
5315 return fold (build (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5316 /* (-A) + B -> B - A */
5317 if (TREE_CODE (arg0) == NEGATE_EXPR)
5318 return fold (build (MINUS_EXPR, type, arg1, TREE_OPERAND (arg0, 0)));
5319 else if (! FLOAT_TYPE_P (type))
5321 if (integer_zerop (arg1))
5322 return non_lvalue (convert (type, arg0));
5324 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
5325 with a constant, and the two constants have no bits in common,
5326 we should treat this as a BIT_IOR_EXPR since this may produce more
5328 if (TREE_CODE (arg0) == BIT_AND_EXPR
5329 && TREE_CODE (arg1) == BIT_AND_EXPR
5330 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5331 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
5332 && integer_zerop (const_binop (BIT_AND_EXPR,
5333 TREE_OPERAND (arg0, 1),
5334 TREE_OPERAND (arg1, 1), 0)))
5336 code = BIT_IOR_EXPR;
5340 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
5341 (plus (plus (mult) (mult)) (foo)) so that we can
5342 take advantage of the factoring cases below. */
5343 if ((TREE_CODE (arg0) == PLUS_EXPR
5344 && TREE_CODE (arg1) == MULT_EXPR)
5345 || (TREE_CODE (arg1) == PLUS_EXPR
5346 && TREE_CODE (arg0) == MULT_EXPR))
5348 tree parg0, parg1, parg, marg;
5350 if (TREE_CODE (arg0) == PLUS_EXPR)
5351 parg = arg0, marg = arg1;
5353 parg = arg1, marg = arg0;
5354 parg0 = TREE_OPERAND (parg, 0);
5355 parg1 = TREE_OPERAND (parg, 1);
5359 if (TREE_CODE (parg0) == MULT_EXPR
5360 && TREE_CODE (parg1) != MULT_EXPR)
5361 return fold (build (PLUS_EXPR, type,
5362 fold (build (PLUS_EXPR, type, parg0, marg)),
5364 if (TREE_CODE (parg0) != MULT_EXPR
5365 && TREE_CODE (parg1) == MULT_EXPR)
5366 return fold (build (PLUS_EXPR, type,
5367 fold (build (PLUS_EXPR, type, parg1, marg)),
5371 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR)
5373 tree arg00, arg01, arg10, arg11;
5374 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
5376 /* (A * C) + (B * C) -> (A+B) * C.
5377 We are most concerned about the case where C is a constant,
5378 but other combinations show up during loop reduction. Since
5379 it is not difficult, try all four possibilities. */
5381 arg00 = TREE_OPERAND (arg0, 0);
5382 arg01 = TREE_OPERAND (arg0, 1);
5383 arg10 = TREE_OPERAND (arg1, 0);
5384 arg11 = TREE_OPERAND (arg1, 1);
5387 if (operand_equal_p (arg01, arg11, 0))
5388 same = arg01, alt0 = arg00, alt1 = arg10;
5389 else if (operand_equal_p (arg00, arg10, 0))
5390 same = arg00, alt0 = arg01, alt1 = arg11;
5391 else if (operand_equal_p (arg00, arg11, 0))
5392 same = arg00, alt0 = arg01, alt1 = arg10;
5393 else if (operand_equal_p (arg01, arg10, 0))
5394 same = arg01, alt0 = arg00, alt1 = arg11;
5396 /* No identical multiplicands; see if we can find a common
5397 power-of-two factor in non-power-of-two multiplies. This
5398 can help in multi-dimensional array access. */
5399 else if (TREE_CODE (arg01) == INTEGER_CST
5400 && TREE_CODE (arg11) == INTEGER_CST
5401 && TREE_INT_CST_HIGH (arg01) == 0
5402 && TREE_INT_CST_HIGH (arg11) == 0)
5404 HOST_WIDE_INT int01, int11, tmp;
5405 int01 = TREE_INT_CST_LOW (arg01);
5406 int11 = TREE_INT_CST_LOW (arg11);
5408 /* Move min of absolute values to int11. */
5409 if ((int01 >= 0 ? int01 : -int01)
5410 < (int11 >= 0 ? int11 : -int11))
5412 tmp = int01, int01 = int11, int11 = tmp;
5413 alt0 = arg00, arg00 = arg10, arg10 = alt0;
5414 alt0 = arg01, arg01 = arg11, arg11 = alt0;
5417 if (exact_log2 (int11) > 0 && int01 % int11 == 0)
5419 alt0 = fold (build (MULT_EXPR, type, arg00,
5420 build_int_2 (int01 / int11, 0)));
5427 return fold (build (MULT_EXPR, type,
5428 fold (build (PLUS_EXPR, type, alt0, alt1)),
5432 /* In IEEE floating point, x+0 may not equal x. */
5433 else if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
5435 && real_zerop (arg1))
5436 return non_lvalue (convert (type, arg0));
5437 /* x+(-0) equals x, even for IEEE. */
5438 else if (TREE_CODE (arg1) == REAL_CST
5439 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (arg1)))
5440 return non_lvalue (convert (type, arg0));
5443 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
5444 is a rotate of A by C1 bits. */
5445 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
5446 is a rotate of A by B bits. */
5448 register enum tree_code code0, code1;
5449 code0 = TREE_CODE (arg0);
5450 code1 = TREE_CODE (arg1);
5451 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
5452 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
5453 && operand_equal_p (TREE_OPERAND (arg0, 0),
5454 TREE_OPERAND (arg1,0), 0)
5455 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5457 register tree tree01, tree11;
5458 register enum tree_code code01, code11;
5460 tree01 = TREE_OPERAND (arg0, 1);
5461 tree11 = TREE_OPERAND (arg1, 1);
5462 STRIP_NOPS (tree01);
5463 STRIP_NOPS (tree11);
5464 code01 = TREE_CODE (tree01);
5465 code11 = TREE_CODE (tree11);
5466 if (code01 == INTEGER_CST
5467 && code11 == INTEGER_CST
5468 && TREE_INT_CST_HIGH (tree01) == 0
5469 && TREE_INT_CST_HIGH (tree11) == 0
5470 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
5471 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
5472 return build (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
5473 code0 == LSHIFT_EXPR ? tree01 : tree11);
5474 else if (code11 == MINUS_EXPR)
5476 tree tree110, tree111;
5477 tree110 = TREE_OPERAND (tree11, 0);
5478 tree111 = TREE_OPERAND (tree11, 1);
5479 STRIP_NOPS (tree110);
5480 STRIP_NOPS (tree111);
5481 if (TREE_CODE (tree110) == INTEGER_CST
5482 && 0 == compare_tree_int (tree110,
5484 (TREE_TYPE (TREE_OPERAND
5486 && operand_equal_p (tree01, tree111, 0))
5487 return build ((code0 == LSHIFT_EXPR
5490 type, TREE_OPERAND (arg0, 0), tree01);
5492 else if (code01 == MINUS_EXPR)
5494 tree tree010, tree011;
5495 tree010 = TREE_OPERAND (tree01, 0);
5496 tree011 = TREE_OPERAND (tree01, 1);
5497 STRIP_NOPS (tree010);
5498 STRIP_NOPS (tree011);
5499 if (TREE_CODE (tree010) == INTEGER_CST
5500 && 0 == compare_tree_int (tree010,
5502 (TREE_TYPE (TREE_OPERAND
5504 && operand_equal_p (tree11, tree011, 0))
5505 return build ((code0 != LSHIFT_EXPR
5508 type, TREE_OPERAND (arg0, 0), tree11);
5515 /* In most languages, can't associate operations on floats through
5516 parentheses. Rather than remember where the parentheses were, we
5517 don't associate floats at all. It shouldn't matter much. However,
5518 associating multiplications is only very slightly inaccurate, so do
5519 that if -ffast-math is specified. */
5522 && (! FLOAT_TYPE_P (type)
5523 || (flag_fast_math && code != MULT_EXPR)))
5525 tree var0, con0, lit0, var1, con1, lit1;
5527 /* Split both trees into variables, constants, and literals. Then
5528 associate each group together, the constants with literals,
5529 then the result with variables. This increases the chances of
5530 literals being recombined later and of generating relocatable
5531 expressions for the sum of a constant and literal. */
5532 var0 = split_tree (arg0, code, &con0, &lit0, 0);
5533 var1 = split_tree (arg1, code, &con1, &lit1, code == MINUS_EXPR);
5535 /* Only do something if we found more than two objects. Otherwise,
5536 nothing has changed and we risk infinite recursion. */
5537 if (2 < ((var0 != 0) + (var1 != 0) + (con0 != 0) + (con1 != 0)
5538 + (lit0 != 0) + (lit1 != 0)))
5540 var0 = associate_trees (var0, var1, code, type);
5541 con0 = associate_trees (con0, con1, code, type);
5542 lit0 = associate_trees (lit0, lit1, code, type);
5543 con0 = associate_trees (con0, lit0, code, type);
5544 return convert (type, associate_trees (var0, con0, code, type));
5549 #if defined (REAL_IS_NOT_DOUBLE) && ! defined (REAL_ARITHMETIC)
5550 if (TREE_CODE (arg1) == REAL_CST)
5552 #endif /* REAL_IS_NOT_DOUBLE, and no REAL_ARITHMETIC */
5554 t1 = const_binop (code, arg0, arg1, 0);
5555 if (t1 != NULL_TREE)
5557 /* The return value should always have
5558 the same type as the original expression. */
5559 if (TREE_TYPE (t1) != TREE_TYPE (t))
5560 t1 = convert (TREE_TYPE (t), t1);
5567 /* A - (-B) -> A + B */
5568 if (TREE_CODE (arg1) == NEGATE_EXPR)
5569 return fold (build (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5570 /* (-A) - CST -> (-CST) - A for floating point (what about ints ?) */
5571 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == REAL_CST)
5573 fold (build (MINUS_EXPR, type,
5574 build_real (TREE_TYPE (arg1),
5575 REAL_VALUE_NEGATE (TREE_REAL_CST (arg1))),
5576 TREE_OPERAND (arg0, 0)));
5578 if (! FLOAT_TYPE_P (type))
5580 if (! wins && integer_zerop (arg0))
5581 return convert (type, negate_expr (arg1));
5582 if (integer_zerop (arg1))
5583 return non_lvalue (convert (type, arg0));
5585 /* (A * C) - (B * C) -> (A-B) * C. Since we are most concerned
5586 about the case where C is a constant, just try one of the
5587 four possibilities. */
5589 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR
5590 && operand_equal_p (TREE_OPERAND (arg0, 1),
5591 TREE_OPERAND (arg1, 1), 0))
5592 return fold (build (MULT_EXPR, type,
5593 fold (build (MINUS_EXPR, type,
5594 TREE_OPERAND (arg0, 0),
5595 TREE_OPERAND (arg1, 0))),
5596 TREE_OPERAND (arg0, 1)));
5599 else if (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
5602 /* Except with IEEE floating point, 0-x equals -x. */
5603 if (! wins && real_zerop (arg0))
5604 return convert (type, negate_expr (arg1));
5605 /* Except with IEEE floating point, x-0 equals x. */
5606 if (real_zerop (arg1))
5607 return non_lvalue (convert (type, arg0));
5610 /* Fold &x - &x. This can happen from &x.foo - &x.
5611 This is unsafe for certain floats even in non-IEEE formats.
5612 In IEEE, it is unsafe because it does wrong for NaNs.
5613 Also note that operand_equal_p is always false if an operand
5616 if ((! FLOAT_TYPE_P (type) || flag_fast_math)
5617 && operand_equal_p (arg0, arg1, 0))
5618 return convert (type, integer_zero_node);
5623 /* (-A) * (-B) -> A * B */
5624 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR)
5625 return fold (build (MULT_EXPR, type, TREE_OPERAND (arg0, 0),
5626 TREE_OPERAND (arg1, 0)));
5628 if (! FLOAT_TYPE_P (type))
5630 if (integer_zerop (arg1))
5631 return omit_one_operand (type, arg1, arg0);
5632 if (integer_onep (arg1))
5633 return non_lvalue (convert (type, arg0));
5635 /* (a * (1 << b)) is (a << b) */
5636 if (TREE_CODE (arg1) == LSHIFT_EXPR
5637 && integer_onep (TREE_OPERAND (arg1, 0)))
5638 return fold (build (LSHIFT_EXPR, type, arg0,
5639 TREE_OPERAND (arg1, 1)));
5640 if (TREE_CODE (arg0) == LSHIFT_EXPR
5641 && integer_onep (TREE_OPERAND (arg0, 0)))
5642 return fold (build (LSHIFT_EXPR, type, arg1,
5643 TREE_OPERAND (arg0, 1)));
5645 if (TREE_CODE (arg1) == INTEGER_CST
5646 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
5648 return convert (type, tem);
5653 /* x*0 is 0, except for IEEE floating point. */
5654 if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
5656 && real_zerop (arg1))
5657 return omit_one_operand (type, arg1, arg0);
5658 /* In IEEE floating point, x*1 is not equivalent to x for snans.
5659 However, ANSI says we can drop signals,
5660 so we can do this anyway. */
5661 if (real_onep (arg1))
5662 return non_lvalue (convert (type, arg0));
5664 if (! wins && real_twop (arg1) && global_bindings_p () == 0
5665 && ! contains_placeholder_p (arg0))
5667 tree arg = save_expr (arg0);
5668 return build (PLUS_EXPR, type, arg, arg);
5675 if (integer_all_onesp (arg1))
5676 return omit_one_operand (type, arg1, arg0);
5677 if (integer_zerop (arg1))
5678 return non_lvalue (convert (type, arg0));
5679 t1 = distribute_bit_expr (code, type, arg0, arg1);
5680 if (t1 != NULL_TREE)
5683 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
5685 This results in more efficient code for machines without a NAND
5686 instruction. Combine will canonicalize to the first form
5687 which will allow use of NAND instructions provided by the
5688 backend if they exist. */
5689 if (TREE_CODE (arg0) == BIT_NOT_EXPR
5690 && TREE_CODE (arg1) == BIT_NOT_EXPR)
5692 return fold (build1 (BIT_NOT_EXPR, type,
5693 build (BIT_AND_EXPR, type,
5694 TREE_OPERAND (arg0, 0),
5695 TREE_OPERAND (arg1, 0))));
5698 /* See if this can be simplified into a rotate first. If that
5699 is unsuccessful continue in the association code. */
5703 if (integer_zerop (arg1))
5704 return non_lvalue (convert (type, arg0));
5705 if (integer_all_onesp (arg1))
5706 return fold (build1 (BIT_NOT_EXPR, type, arg0));
5708 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
5709 with a constant, and the two constants have no bits in common,
5710 we should treat this as a BIT_IOR_EXPR since this may produce more
5712 if (TREE_CODE (arg0) == BIT_AND_EXPR
5713 && TREE_CODE (arg1) == BIT_AND_EXPR
5714 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5715 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
5716 && integer_zerop (const_binop (BIT_AND_EXPR,
5717 TREE_OPERAND (arg0, 1),
5718 TREE_OPERAND (arg1, 1), 0)))
5720 code = BIT_IOR_EXPR;
5724 /* See if this can be simplified into a rotate first. If that
5725 is unsuccessful continue in the association code. */
5730 if (integer_all_onesp (arg1))
5731 return non_lvalue (convert (type, arg0));
5732 if (integer_zerop (arg1))
5733 return omit_one_operand (type, arg1, arg0);
5734 t1 = distribute_bit_expr (code, type, arg0, arg1);
5735 if (t1 != NULL_TREE)
5737 /* Simplify ((int)c & 0x377) into (int)c, if c is unsigned char. */
5738 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == NOP_EXPR
5739 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg1, 0))))
5742 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg1, 0)));
5744 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
5745 && (~TREE_INT_CST_LOW (arg0)
5746 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
5747 return build1 (NOP_EXPR, type, TREE_OPERAND (arg1, 0));
5749 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
5750 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5753 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
5755 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
5756 && (~TREE_INT_CST_LOW (arg1)
5757 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
5758 return build1 (NOP_EXPR, type, TREE_OPERAND (arg0, 0));
5761 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
5763 This results in more efficient code for machines without a NOR
5764 instruction. Combine will canonicalize to the first form
5765 which will allow use of NOR instructions provided by the
5766 backend if they exist. */
5767 if (TREE_CODE (arg0) == BIT_NOT_EXPR
5768 && TREE_CODE (arg1) == BIT_NOT_EXPR)
5770 return fold (build1 (BIT_NOT_EXPR, type,
5771 build (BIT_IOR_EXPR, type,
5772 TREE_OPERAND (arg0, 0),
5773 TREE_OPERAND (arg1, 0))));
5778 case BIT_ANDTC_EXPR:
5779 if (integer_all_onesp (arg0))
5780 return non_lvalue (convert (type, arg1));
5781 if (integer_zerop (arg0))
5782 return omit_one_operand (type, arg0, arg1);
5783 if (TREE_CODE (arg1) == INTEGER_CST)
5785 arg1 = fold (build1 (BIT_NOT_EXPR, type, arg1));
5786 code = BIT_AND_EXPR;
5792 /* In most cases, do nothing with a divide by zero. */
5793 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
5794 #ifndef REAL_INFINITY
5795 if (TREE_CODE (arg1) == REAL_CST && real_zerop (arg1))
5798 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
5800 /* (-A) / (-B) -> A / B */
5801 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR)
5802 return fold (build (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
5803 TREE_OPERAND (arg1, 0)));
5805 /* In IEEE floating point, x/1 is not equivalent to x for snans.
5806 However, ANSI says we can drop signals, so we can do this anyway. */
5807 if (real_onep (arg1))
5808 return non_lvalue (convert (type, arg0));
5810 /* If ARG1 is a constant, we can convert this to a multiply by the
5811 reciprocal. This does not have the same rounding properties,
5812 so only do this if -ffast-math. We can actually always safely
5813 do it if ARG1 is a power of two, but it's hard to tell if it is
5814 or not in a portable manner. */
5815 if (TREE_CODE (arg1) == REAL_CST)
5818 && 0 != (tem = const_binop (code, build_real (type, dconst1),
5820 return fold (build (MULT_EXPR, type, arg0, tem));
5821 /* Find the reciprocal if optimizing and the result is exact. */
5825 r = TREE_REAL_CST (arg1);
5826 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
5828 tem = build_real (type, r);
5829 return fold (build (MULT_EXPR, type, arg0, tem));
5835 case TRUNC_DIV_EXPR:
5836 case ROUND_DIV_EXPR:
5837 case FLOOR_DIV_EXPR:
5839 case EXACT_DIV_EXPR:
5840 if (integer_onep (arg1))
5841 return non_lvalue (convert (type, arg0));
5842 if (integer_zerop (arg1))
5845 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
5846 operation, EXACT_DIV_EXPR.
5848 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
5849 At one time others generated faster code, it's not clear if they do
5850 after the last round to changes to the DIV code in expmed.c. */
5851 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
5852 && multiple_of_p (type, arg0, arg1))
5853 return fold (build (EXACT_DIV_EXPR, type, arg0, arg1));
5855 if (TREE_CODE (arg1) == INTEGER_CST
5856 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
5858 return convert (type, tem);
5863 case FLOOR_MOD_EXPR:
5864 case ROUND_MOD_EXPR:
5865 case TRUNC_MOD_EXPR:
5866 if (integer_onep (arg1))
5867 return omit_one_operand (type, integer_zero_node, arg0);
5868 if (integer_zerop (arg1))
5871 if (TREE_CODE (arg1) == INTEGER_CST
5872 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
5874 return convert (type, tem);
5882 if (integer_zerop (arg1))
5883 return non_lvalue (convert (type, arg0));
5884 /* Since negative shift count is not well-defined,
5885 don't try to compute it in the compiler. */
5886 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
5888 /* Rewrite an LROTATE_EXPR by a constant into an
5889 RROTATE_EXPR by a new constant. */
5890 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
5892 TREE_SET_CODE (t, RROTATE_EXPR);
5893 code = RROTATE_EXPR;
5894 TREE_OPERAND (t, 1) = arg1
5897 convert (TREE_TYPE (arg1),
5898 build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type)), 0)),
5900 if (tree_int_cst_sgn (arg1) < 0)
5904 /* If we have a rotate of a bit operation with the rotate count and
5905 the second operand of the bit operation both constant,
5906 permute the two operations. */
5907 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
5908 && (TREE_CODE (arg0) == BIT_AND_EXPR
5909 || TREE_CODE (arg0) == BIT_ANDTC_EXPR
5910 || TREE_CODE (arg0) == BIT_IOR_EXPR
5911 || TREE_CODE (arg0) == BIT_XOR_EXPR)
5912 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
5913 return fold (build (TREE_CODE (arg0), type,
5914 fold (build (code, type,
5915 TREE_OPERAND (arg0, 0), arg1)),
5916 fold (build (code, type,
5917 TREE_OPERAND (arg0, 1), arg1))));
5919 /* Two consecutive rotates adding up to the width of the mode can
5921 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
5922 && TREE_CODE (arg0) == RROTATE_EXPR
5923 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5924 && TREE_INT_CST_HIGH (arg1) == 0
5925 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
5926 && ((TREE_INT_CST_LOW (arg1)
5927 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
5928 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type))))
5929 return TREE_OPERAND (arg0, 0);
5934 if (operand_equal_p (arg0, arg1, 0))
5935 return omit_one_operand (type, arg0, arg1);
5936 if (INTEGRAL_TYPE_P (type)
5937 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), 1))
5938 return omit_one_operand (type, arg1, arg0);
5942 if (operand_equal_p (arg0, arg1, 0))
5943 return omit_one_operand (type, arg0, arg1);
5944 if (INTEGRAL_TYPE_P (type)
5945 && TYPE_MAX_VALUE (type)
5946 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), 1))
5947 return omit_one_operand (type, arg1, arg0);
5950 case TRUTH_NOT_EXPR:
5951 /* Note that the operand of this must be an int
5952 and its values must be 0 or 1.
5953 ("true" is a fixed value perhaps depending on the language,
5954 but we don't handle values other than 1 correctly yet.) */
5955 tem = invert_truthvalue (arg0);
5956 /* Avoid infinite recursion. */
5957 if (TREE_CODE (tem) == TRUTH_NOT_EXPR)
5959 return convert (type, tem);
5961 case TRUTH_ANDIF_EXPR:
5962 /* Note that the operands of this must be ints
5963 and their values must be 0 or 1.
5964 ("true" is a fixed value perhaps depending on the language.) */
5965 /* If first arg is constant zero, return it. */
5966 if (integer_zerop (arg0))
5967 return convert (type, arg0);
5968 case TRUTH_AND_EXPR:
5969 /* If either arg is constant true, drop it. */
5970 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
5971 return non_lvalue (convert (type, arg1));
5972 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
5973 return non_lvalue (convert (type, arg0));
5974 /* If second arg is constant zero, result is zero, but first arg
5975 must be evaluated. */
5976 if (integer_zerop (arg1))
5977 return omit_one_operand (type, arg1, arg0);
5978 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
5979 case will be handled here. */
5980 if (integer_zerop (arg0))
5981 return omit_one_operand (type, arg0, arg1);
5984 /* We only do these simplifications if we are optimizing. */
5988 /* Check for things like (A || B) && (A || C). We can convert this
5989 to A || (B && C). Note that either operator can be any of the four
5990 truth and/or operations and the transformation will still be
5991 valid. Also note that we only care about order for the
5992 ANDIF and ORIF operators. If B contains side effects, this
5993 might change the truth-value of A. */
5994 if (TREE_CODE (arg0) == TREE_CODE (arg1)
5995 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
5996 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
5997 || TREE_CODE (arg0) == TRUTH_AND_EXPR
5998 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
5999 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
6001 tree a00 = TREE_OPERAND (arg0, 0);
6002 tree a01 = TREE_OPERAND (arg0, 1);
6003 tree a10 = TREE_OPERAND (arg1, 0);
6004 tree a11 = TREE_OPERAND (arg1, 1);
6005 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
6006 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
6007 && (code == TRUTH_AND_EXPR
6008 || code == TRUTH_OR_EXPR));
6010 if (operand_equal_p (a00, a10, 0))
6011 return fold (build (TREE_CODE (arg0), type, a00,
6012 fold (build (code, type, a01, a11))));
6013 else if (commutative && operand_equal_p (a00, a11, 0))
6014 return fold (build (TREE_CODE (arg0), type, a00,
6015 fold (build (code, type, a01, a10))));
6016 else if (commutative && operand_equal_p (a01, a10, 0))
6017 return fold (build (TREE_CODE (arg0), type, a01,
6018 fold (build (code, type, a00, a11))));
6020 /* This case if tricky because we must either have commutative
6021 operators or else A10 must not have side-effects. */
6023 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
6024 && operand_equal_p (a01, a11, 0))
6025 return fold (build (TREE_CODE (arg0), type,
6026 fold (build (code, type, a00, a10)),
6030 /* See if we can build a range comparison. */
6031 if (0 != (tem = fold_range_test (t)))
6034 /* Check for the possibility of merging component references. If our
6035 lhs is another similar operation, try to merge its rhs with our
6036 rhs. Then try to merge our lhs and rhs. */
6037 if (TREE_CODE (arg0) == code
6038 && 0 != (tem = fold_truthop (code, type,
6039 TREE_OPERAND (arg0, 1), arg1)))
6040 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6042 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
6047 case TRUTH_ORIF_EXPR:
6048 /* Note that the operands of this must be ints
6049 and their values must be 0 or true.
6050 ("true" is a fixed value perhaps depending on the language.) */
6051 /* If first arg is constant true, return it. */
6052 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
6053 return convert (type, arg0);
6055 /* If either arg is constant zero, drop it. */
6056 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
6057 return non_lvalue (convert (type, arg1));
6058 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1))
6059 return non_lvalue (convert (type, arg0));
6060 /* If second arg is constant true, result is true, but we must
6061 evaluate first arg. */
6062 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
6063 return omit_one_operand (type, arg1, arg0);
6064 /* Likewise for first arg, but note this only occurs here for
6066 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
6067 return omit_one_operand (type, arg0, arg1);
6070 case TRUTH_XOR_EXPR:
6071 /* If either arg is constant zero, drop it. */
6072 if (integer_zerop (arg0))
6073 return non_lvalue (convert (type, arg1));
6074 if (integer_zerop (arg1))
6075 return non_lvalue (convert (type, arg0));
6076 /* If either arg is constant true, this is a logical inversion. */
6077 if (integer_onep (arg0))
6078 return non_lvalue (convert (type, invert_truthvalue (arg1)));
6079 if (integer_onep (arg1))
6080 return non_lvalue (convert (type, invert_truthvalue (arg0)));
6089 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
6091 /* (-a) CMP (-b) -> b CMP a */
6092 if (TREE_CODE (arg0) == NEGATE_EXPR
6093 && TREE_CODE (arg1) == NEGATE_EXPR)
6094 return fold (build (code, type, TREE_OPERAND (arg1, 0),
6095 TREE_OPERAND (arg0, 0)));
6096 /* (-a) CMP CST -> a swap(CMP) (-CST) */
6097 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == REAL_CST)
6100 (swap_tree_comparison (code), type,
6101 TREE_OPERAND (arg0, 0),
6102 build_real (TREE_TYPE (arg1),
6103 REAL_VALUE_NEGATE (TREE_REAL_CST (arg1)))));
6104 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
6105 /* a CMP (-0) -> a CMP 0 */
6106 if (TREE_CODE (arg1) == REAL_CST
6107 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (arg1)))
6108 return fold (build (code, type, arg0,
6109 build_real (TREE_TYPE (arg1), dconst0)));
6113 /* If one arg is a constant integer, put it last. */
6114 if (TREE_CODE (arg0) == INTEGER_CST
6115 && TREE_CODE (arg1) != INTEGER_CST)
6117 TREE_OPERAND (t, 0) = arg1;
6118 TREE_OPERAND (t, 1) = arg0;
6119 arg0 = TREE_OPERAND (t, 0);
6120 arg1 = TREE_OPERAND (t, 1);
6121 code = swap_tree_comparison (code);
6122 TREE_SET_CODE (t, code);
6125 /* Convert foo++ == CONST into ++foo == CONST + INCR.
6126 First, see if one arg is constant; find the constant arg
6127 and the other one. */
6129 tree constop = 0, varop = NULL_TREE;
6130 int constopnum = -1;
6132 if (TREE_CONSTANT (arg1))
6133 constopnum = 1, constop = arg1, varop = arg0;
6134 if (TREE_CONSTANT (arg0))
6135 constopnum = 0, constop = arg0, varop = arg1;
6137 if (constop && TREE_CODE (varop) == POSTINCREMENT_EXPR)
6139 /* This optimization is invalid for ordered comparisons
6140 if CONST+INCR overflows or if foo+incr might overflow.
6141 This optimization is invalid for floating point due to rounding.
6142 For pointer types we assume overflow doesn't happen. */
6143 if (POINTER_TYPE_P (TREE_TYPE (varop))
6144 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
6145 && (code == EQ_EXPR || code == NE_EXPR)))
6148 = fold (build (PLUS_EXPR, TREE_TYPE (varop),
6149 constop, TREE_OPERAND (varop, 1)));
6151 /* Do not overwrite the current varop to be a preincrement,
6152 create a new node so that we won't confuse our caller who
6153 might create trees and throw them away, reusing the
6154 arguments that they passed to build. This shows up in
6155 the THEN or ELSE parts of ?: being postincrements. */
6156 varop = build (PREINCREMENT_EXPR, TREE_TYPE (varop),
6157 TREE_OPERAND (varop, 0),
6158 TREE_OPERAND (varop, 1));
6160 /* If VAROP is a reference to a bitfield, we must mask
6161 the constant by the width of the field. */
6162 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
6163 && DECL_BIT_FIELD(TREE_OPERAND
6164 (TREE_OPERAND (varop, 0), 1)))
6167 = TREE_INT_CST_LOW (DECL_SIZE
6169 (TREE_OPERAND (varop, 0), 1)));
6170 tree mask, unsigned_type;
6171 unsigned int precision;
6172 tree folded_compare;
6174 /* First check whether the comparison would come out
6175 always the same. If we don't do that we would
6176 change the meaning with the masking. */
6177 if (constopnum == 0)
6178 folded_compare = fold (build (code, type, constop,
6179 TREE_OPERAND (varop, 0)));
6181 folded_compare = fold (build (code, type,
6182 TREE_OPERAND (varop, 0),
6184 if (integer_zerop (folded_compare)
6185 || integer_onep (folded_compare))
6186 return omit_one_operand (type, folded_compare, varop);
6188 unsigned_type = type_for_size (size, 1);
6189 precision = TYPE_PRECISION (unsigned_type);
6190 mask = build_int_2 (~0, ~0);
6191 TREE_TYPE (mask) = unsigned_type;
6192 force_fit_type (mask, 0);
6193 mask = const_binop (RSHIFT_EXPR, mask,
6194 size_int (precision - size), 0);
6195 newconst = fold (build (BIT_AND_EXPR,
6196 TREE_TYPE (varop), newconst,
6197 convert (TREE_TYPE (varop),
6202 t = build (code, type,
6203 (constopnum == 0) ? newconst : varop,
6204 (constopnum == 1) ? newconst : varop);
6208 else if (constop && TREE_CODE (varop) == POSTDECREMENT_EXPR)
6210 if (POINTER_TYPE_P (TREE_TYPE (varop))
6211 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
6212 && (code == EQ_EXPR || code == NE_EXPR)))
6215 = fold (build (MINUS_EXPR, TREE_TYPE (varop),
6216 constop, TREE_OPERAND (varop, 1)));
6218 /* Do not overwrite the current varop to be a predecrement,
6219 create a new node so that we won't confuse our caller who
6220 might create trees and throw them away, reusing the
6221 arguments that they passed to build. This shows up in
6222 the THEN or ELSE parts of ?: being postdecrements. */
6223 varop = build (PREDECREMENT_EXPR, TREE_TYPE (varop),
6224 TREE_OPERAND (varop, 0),
6225 TREE_OPERAND (varop, 1));
6227 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
6228 && DECL_BIT_FIELD(TREE_OPERAND
6229 (TREE_OPERAND (varop, 0), 1)))
6232 = TREE_INT_CST_LOW (DECL_SIZE
6234 (TREE_OPERAND (varop, 0), 1)));
6235 tree mask, unsigned_type;
6236 unsigned int precision;
6237 tree folded_compare;
6239 if (constopnum == 0)
6240 folded_compare = fold (build (code, type, constop,
6241 TREE_OPERAND (varop, 0)));
6243 folded_compare = fold (build (code, type,
6244 TREE_OPERAND (varop, 0),
6246 if (integer_zerop (folded_compare)
6247 || integer_onep (folded_compare))
6248 return omit_one_operand (type, folded_compare, varop);
6250 unsigned_type = type_for_size (size, 1);
6251 precision = TYPE_PRECISION (unsigned_type);
6252 mask = build_int_2 (~0, ~0);
6253 TREE_TYPE (mask) = TREE_TYPE (varop);
6254 force_fit_type (mask, 0);
6255 mask = const_binop (RSHIFT_EXPR, mask,
6256 size_int (precision - size), 0);
6257 newconst = fold (build (BIT_AND_EXPR,
6258 TREE_TYPE (varop), newconst,
6259 convert (TREE_TYPE (varop),
6264 t = build (code, type,
6265 (constopnum == 0) ? newconst : varop,
6266 (constopnum == 1) ? newconst : varop);
6272 /* Change X >= CST to X > (CST - 1) if CST is positive. */
6273 if (TREE_CODE (arg1) == INTEGER_CST
6274 && TREE_CODE (arg0) != INTEGER_CST
6275 && tree_int_cst_sgn (arg1) > 0)
6277 switch (TREE_CODE (t))
6281 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6282 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6287 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6288 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6296 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
6297 a MINUS_EXPR of a constant, we can convert it into a comparison with
6298 a revised constant as long as no overflow occurs. */
6299 if ((code == EQ_EXPR || code == NE_EXPR)
6300 && TREE_CODE (arg1) == INTEGER_CST
6301 && (TREE_CODE (arg0) == PLUS_EXPR
6302 || TREE_CODE (arg0) == MINUS_EXPR)
6303 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6304 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
6305 ? MINUS_EXPR : PLUS_EXPR,
6306 arg1, TREE_OPERAND (arg0, 1), 0))
6307 && ! TREE_CONSTANT_OVERFLOW (tem))
6308 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6310 /* Similarly for a NEGATE_EXPR. */
6311 else if ((code == EQ_EXPR || code == NE_EXPR)
6312 && TREE_CODE (arg0) == NEGATE_EXPR
6313 && TREE_CODE (arg1) == INTEGER_CST
6314 && 0 != (tem = negate_expr (arg1))
6315 && TREE_CODE (tem) == INTEGER_CST
6316 && ! TREE_CONSTANT_OVERFLOW (tem))
6317 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6319 /* If we have X - Y == 0, we can convert that to X == Y and similarly
6320 for !=. Don't do this for ordered comparisons due to overflow. */
6321 else if ((code == NE_EXPR || code == EQ_EXPR)
6322 && integer_zerop (arg1) && TREE_CODE (arg0) == MINUS_EXPR)
6323 return fold (build (code, type,
6324 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1)));
6326 /* If we are widening one operand of an integer comparison,
6327 see if the other operand is similarly being widened. Perhaps we
6328 can do the comparison in the narrower type. */
6329 else if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
6330 && TREE_CODE (arg0) == NOP_EXPR
6331 && (tem = get_unwidened (arg0, NULL_TREE)) != arg0
6332 && (t1 = get_unwidened (arg1, TREE_TYPE (tem))) != 0
6333 && (TREE_TYPE (t1) == TREE_TYPE (tem)
6334 || (TREE_CODE (t1) == INTEGER_CST
6335 && int_fits_type_p (t1, TREE_TYPE (tem)))))
6336 return fold (build (code, type, tem, convert (TREE_TYPE (tem), t1)));
6338 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
6339 constant, we can simplify it. */
6340 else if (TREE_CODE (arg1) == INTEGER_CST
6341 && (TREE_CODE (arg0) == MIN_EXPR
6342 || TREE_CODE (arg0) == MAX_EXPR)
6343 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
6344 return optimize_minmax_comparison (t);
6346 /* If we are comparing an ABS_EXPR with a constant, we can
6347 convert all the cases into explicit comparisons, but they may
6348 well not be faster than doing the ABS and one comparison.
6349 But ABS (X) <= C is a range comparison, which becomes a subtraction
6350 and a comparison, and is probably faster. */
6351 else if (code == LE_EXPR && TREE_CODE (arg1) == INTEGER_CST
6352 && TREE_CODE (arg0) == ABS_EXPR
6353 && ! TREE_SIDE_EFFECTS (arg0)
6354 && (0 != (tem = negate_expr (arg1)))
6355 && TREE_CODE (tem) == INTEGER_CST
6356 && ! TREE_CONSTANT_OVERFLOW (tem))
6357 return fold (build (TRUTH_ANDIF_EXPR, type,
6358 build (GE_EXPR, type, TREE_OPERAND (arg0, 0), tem),
6359 build (LE_EXPR, type,
6360 TREE_OPERAND (arg0, 0), arg1)));
6362 /* If this is an EQ or NE comparison with zero and ARG0 is
6363 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
6364 two operations, but the latter can be done in one less insn
6365 on machines that have only two-operand insns or on which a
6366 constant cannot be the first operand. */
6367 if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR)
6368 && TREE_CODE (arg0) == BIT_AND_EXPR)
6370 if (TREE_CODE (TREE_OPERAND (arg0, 0)) == LSHIFT_EXPR
6371 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 0), 0)))
6373 fold (build (code, type,
6374 build (BIT_AND_EXPR, TREE_TYPE (arg0),
6376 TREE_TYPE (TREE_OPERAND (arg0, 0)),
6377 TREE_OPERAND (arg0, 1),
6378 TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)),
6379 convert (TREE_TYPE (arg0),
6382 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
6383 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
6385 fold (build (code, type,
6386 build (BIT_AND_EXPR, TREE_TYPE (arg0),
6388 TREE_TYPE (TREE_OPERAND (arg0, 1)),
6389 TREE_OPERAND (arg0, 0),
6390 TREE_OPERAND (TREE_OPERAND (arg0, 1), 1)),
6391 convert (TREE_TYPE (arg0),
6396 /* If this is an NE or EQ comparison of zero against the result of a
6397 signed MOD operation whose second operand is a power of 2, make
6398 the MOD operation unsigned since it is simpler and equivalent. */
6399 if ((code == NE_EXPR || code == EQ_EXPR)
6400 && integer_zerop (arg1)
6401 && ! TREE_UNSIGNED (TREE_TYPE (arg0))
6402 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
6403 || TREE_CODE (arg0) == CEIL_MOD_EXPR
6404 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
6405 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
6406 && integer_pow2p (TREE_OPERAND (arg0, 1)))
6408 tree newtype = unsigned_type (TREE_TYPE (arg0));
6409 tree newmod = build (TREE_CODE (arg0), newtype,
6410 convert (newtype, TREE_OPERAND (arg0, 0)),
6411 convert (newtype, TREE_OPERAND (arg0, 1)));
6413 return build (code, type, newmod, convert (newtype, arg1));
6416 /* If this is an NE comparison of zero with an AND of one, remove the
6417 comparison since the AND will give the correct value. */
6418 if (code == NE_EXPR && integer_zerop (arg1)
6419 && TREE_CODE (arg0) == BIT_AND_EXPR
6420 && integer_onep (TREE_OPERAND (arg0, 1)))
6421 return convert (type, arg0);
6423 /* If we have (A & C) == C where C is a power of 2, convert this into
6424 (A & C) != 0. Similarly for NE_EXPR. */
6425 if ((code == EQ_EXPR || code == NE_EXPR)
6426 && TREE_CODE (arg0) == BIT_AND_EXPR
6427 && integer_pow2p (TREE_OPERAND (arg0, 1))
6428 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
6429 return build (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
6430 arg0, integer_zero_node);
6432 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
6433 and similarly for >= into !=. */
6434 if ((code == LT_EXPR || code == GE_EXPR)
6435 && TREE_UNSIGNED (TREE_TYPE (arg0))
6436 && TREE_CODE (arg1) == LSHIFT_EXPR
6437 && integer_onep (TREE_OPERAND (arg1, 0)))
6438 return build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
6439 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
6440 TREE_OPERAND (arg1, 1)),
6441 convert (TREE_TYPE (arg0), integer_zero_node));
6443 else if ((code == LT_EXPR || code == GE_EXPR)
6444 && TREE_UNSIGNED (TREE_TYPE (arg0))
6445 && (TREE_CODE (arg1) == NOP_EXPR
6446 || TREE_CODE (arg1) == CONVERT_EXPR)
6447 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
6448 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
6450 build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
6451 convert (TREE_TYPE (arg0),
6452 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
6453 TREE_OPERAND (TREE_OPERAND (arg1, 0), 1))),
6454 convert (TREE_TYPE (arg0), integer_zero_node));
6456 /* Simplify comparison of something with itself. (For IEEE
6457 floating-point, we can only do some of these simplifications.) */
6458 if (operand_equal_p (arg0, arg1, 0))
6465 if (INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
6466 return constant_boolean_node (1, type);
6468 TREE_SET_CODE (t, code);
6472 /* For NE, we can only do this simplification if integer. */
6473 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
6475 /* ... fall through ... */
6478 return constant_boolean_node (0, type);
6484 /* An unsigned comparison against 0 can be simplified. */
6485 if (integer_zerop (arg1)
6486 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
6487 || POINTER_TYPE_P (TREE_TYPE (arg1)))
6488 && TREE_UNSIGNED (TREE_TYPE (arg1)))
6490 switch (TREE_CODE (t))
6494 TREE_SET_CODE (t, NE_EXPR);
6498 TREE_SET_CODE (t, EQ_EXPR);
6501 return omit_one_operand (type,
6502 convert (type, integer_one_node),
6505 return omit_one_operand (type,
6506 convert (type, integer_zero_node),
6513 /* Comparisons with the highest or lowest possible integer of
6514 the specified size will have known values and an unsigned
6515 <= 0x7fffffff can be simplified. */
6517 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1)));
6519 if (TREE_CODE (arg1) == INTEGER_CST
6520 && ! TREE_CONSTANT_OVERFLOW (arg1)
6521 && width <= HOST_BITS_PER_WIDE_INT
6522 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
6523 || POINTER_TYPE_P (TREE_TYPE (arg1))))
6525 if (TREE_INT_CST_HIGH (arg1) == 0
6526 && (TREE_INT_CST_LOW (arg1)
6527 == ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1)
6528 && ! TREE_UNSIGNED (TREE_TYPE (arg1)))
6529 switch (TREE_CODE (t))
6532 return omit_one_operand (type,
6533 convert (type, integer_zero_node),
6536 TREE_SET_CODE (t, EQ_EXPR);
6540 return omit_one_operand (type,
6541 convert (type, integer_one_node),
6544 TREE_SET_CODE (t, NE_EXPR);
6551 else if (TREE_INT_CST_HIGH (arg1) == -1
6552 && (- TREE_INT_CST_LOW (arg1)
6553 == ((unsigned HOST_WIDE_INT) 1 << (width - 1)))
6554 && ! TREE_UNSIGNED (TREE_TYPE (arg1)))
6555 switch (TREE_CODE (t))
6558 return omit_one_operand (type,
6559 convert (type, integer_zero_node),
6562 TREE_SET_CODE (t, EQ_EXPR);
6566 return omit_one_operand (type,
6567 convert (type, integer_one_node),
6570 TREE_SET_CODE (t, NE_EXPR);
6577 else if (TREE_INT_CST_HIGH (arg1) == 0
6578 && (TREE_INT_CST_LOW (arg1)
6579 == ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1)
6580 && TREE_UNSIGNED (TREE_TYPE (arg1)))
6582 switch (TREE_CODE (t))
6585 return fold (build (GE_EXPR, type,
6586 convert (signed_type (TREE_TYPE (arg0)),
6588 convert (signed_type (TREE_TYPE (arg1)),
6589 integer_zero_node)));
6591 return fold (build (LT_EXPR, type,
6592 convert (signed_type (TREE_TYPE (arg0)),
6594 convert (signed_type (TREE_TYPE (arg1)),
6595 integer_zero_node)));
6603 /* If we are comparing an expression that just has comparisons
6604 of two integer values, arithmetic expressions of those comparisons,
6605 and constants, we can simplify it. There are only three cases
6606 to check: the two values can either be equal, the first can be
6607 greater, or the second can be greater. Fold the expression for
6608 those three values. Since each value must be 0 or 1, we have
6609 eight possibilities, each of which corresponds to the constant 0
6610 or 1 or one of the six possible comparisons.
6612 This handles common cases like (a > b) == 0 but also handles
6613 expressions like ((x > y) - (y > x)) > 0, which supposedly
6614 occur in macroized code. */
6616 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
6618 tree cval1 = 0, cval2 = 0;
6621 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
6622 /* Don't handle degenerate cases here; they should already
6623 have been handled anyway. */
6624 && cval1 != 0 && cval2 != 0
6625 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
6626 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
6627 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
6628 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
6629 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
6630 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
6631 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
6633 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
6634 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
6636 /* We can't just pass T to eval_subst in case cval1 or cval2
6637 was the same as ARG1. */
6640 = fold (build (code, type,
6641 eval_subst (arg0, cval1, maxval, cval2, minval),
6644 = fold (build (code, type,
6645 eval_subst (arg0, cval1, maxval, cval2, maxval),
6648 = fold (build (code, type,
6649 eval_subst (arg0, cval1, minval, cval2, maxval),
6652 /* All three of these results should be 0 or 1. Confirm they
6653 are. Then use those values to select the proper code
6656 if ((integer_zerop (high_result)
6657 || integer_onep (high_result))
6658 && (integer_zerop (equal_result)
6659 || integer_onep (equal_result))
6660 && (integer_zerop (low_result)
6661 || integer_onep (low_result)))
6663 /* Make a 3-bit mask with the high-order bit being the
6664 value for `>', the next for '=', and the low for '<'. */
6665 switch ((integer_onep (high_result) * 4)
6666 + (integer_onep (equal_result) * 2)
6667 + integer_onep (low_result))
6671 return omit_one_operand (type, integer_zero_node, arg0);
6692 return omit_one_operand (type, integer_one_node, arg0);
6695 t = build (code, type, cval1, cval2);
6697 return save_expr (t);
6704 /* If this is a comparison of a field, we may be able to simplify it. */
6705 if ((TREE_CODE (arg0) == COMPONENT_REF
6706 || TREE_CODE (arg0) == BIT_FIELD_REF)
6707 && (code == EQ_EXPR || code == NE_EXPR)
6708 /* Handle the constant case even without -O
6709 to make sure the warnings are given. */
6710 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
6712 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
6716 /* If this is a comparison of complex values and either or both sides
6717 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
6718 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
6719 This may prevent needless evaluations. */
6720 if ((code == EQ_EXPR || code == NE_EXPR)
6721 && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
6722 && (TREE_CODE (arg0) == COMPLEX_EXPR
6723 || TREE_CODE (arg1) == COMPLEX_EXPR
6724 || TREE_CODE (arg0) == COMPLEX_CST
6725 || TREE_CODE (arg1) == COMPLEX_CST))
6727 tree subtype = TREE_TYPE (TREE_TYPE (arg0));
6728 tree real0, imag0, real1, imag1;
6730 arg0 = save_expr (arg0);
6731 arg1 = save_expr (arg1);
6732 real0 = fold (build1 (REALPART_EXPR, subtype, arg0));
6733 imag0 = fold (build1 (IMAGPART_EXPR, subtype, arg0));
6734 real1 = fold (build1 (REALPART_EXPR, subtype, arg1));
6735 imag1 = fold (build1 (IMAGPART_EXPR, subtype, arg1));
6737 return fold (build ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR
6740 fold (build (code, type, real0, real1)),
6741 fold (build (code, type, imag0, imag1))));
6744 /* From here on, the only cases we handle are when the result is
6745 known to be a constant.
6747 To compute GT, swap the arguments and do LT.
6748 To compute GE, do LT and invert the result.
6749 To compute LE, swap the arguments, do LT and invert the result.
6750 To compute NE, do EQ and invert the result.
6752 Therefore, the code below must handle only EQ and LT. */
6754 if (code == LE_EXPR || code == GT_EXPR)
6756 tem = arg0, arg0 = arg1, arg1 = tem;
6757 code = swap_tree_comparison (code);
6760 /* Note that it is safe to invert for real values here because we
6761 will check below in the one case that it matters. */
6765 if (code == NE_EXPR || code == GE_EXPR)
6768 code = invert_tree_comparison (code);
6771 /* Compute a result for LT or EQ if args permit;
6772 otherwise return T. */
6773 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
6775 if (code == EQ_EXPR)
6776 t1 = build_int_2 (tree_int_cst_equal (arg0, arg1), 0);
6778 t1 = build_int_2 ((TREE_UNSIGNED (TREE_TYPE (arg0))
6779 ? INT_CST_LT_UNSIGNED (arg0, arg1)
6780 : INT_CST_LT (arg0, arg1)),
6784 #if 0 /* This is no longer useful, but breaks some real code. */
6785 /* Assume a nonexplicit constant cannot equal an explicit one,
6786 since such code would be undefined anyway.
6787 Exception: on sysvr4, using #pragma weak,
6788 a label can come out as 0. */
6789 else if (TREE_CODE (arg1) == INTEGER_CST
6790 && !integer_zerop (arg1)
6791 && TREE_CONSTANT (arg0)
6792 && TREE_CODE (arg0) == ADDR_EXPR
6794 t1 = build_int_2 (0, 0);
6796 /* Two real constants can be compared explicitly. */
6797 else if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
6799 /* If either operand is a NaN, the result is false with two
6800 exceptions: First, an NE_EXPR is true on NaNs, but that case
6801 is already handled correctly since we will be inverting the
6802 result for NE_EXPR. Second, if we had inverted a LE_EXPR
6803 or a GE_EXPR into a LT_EXPR, we must return true so that it
6804 will be inverted into false. */
6806 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
6807 || REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
6808 t1 = build_int_2 (invert && code == LT_EXPR, 0);
6810 else if (code == EQ_EXPR)
6811 t1 = build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (arg0),
6812 TREE_REAL_CST (arg1)),
6815 t1 = build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (arg0),
6816 TREE_REAL_CST (arg1)),
6820 if (t1 == NULL_TREE)
6824 TREE_INT_CST_LOW (t1) ^= 1;
6826 TREE_TYPE (t1) = type;
6827 if (TREE_CODE (type) == BOOLEAN_TYPE)
6828 return truthvalue_conversion (t1);
6832 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
6833 so all simple results must be passed through pedantic_non_lvalue. */
6834 if (TREE_CODE (arg0) == INTEGER_CST)
6835 return pedantic_non_lvalue
6836 (TREE_OPERAND (t, (integer_zerop (arg0) ? 2 : 1)));
6837 else if (operand_equal_p (arg1, TREE_OPERAND (expr, 2), 0))
6838 return pedantic_omit_one_operand (type, arg1, arg0);
6840 /* If the second operand is zero, invert the comparison and swap
6841 the second and third operands. Likewise if the second operand
6842 is constant and the third is not or if the third operand is
6843 equivalent to the first operand of the comparison. */
6845 if (integer_zerop (arg1)
6846 || (TREE_CONSTANT (arg1) && ! TREE_CONSTANT (TREE_OPERAND (t, 2)))
6847 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
6848 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
6849 TREE_OPERAND (t, 2),
6850 TREE_OPERAND (arg0, 1))))
6852 /* See if this can be inverted. If it can't, possibly because
6853 it was a floating-point inequality comparison, don't do
6855 tem = invert_truthvalue (arg0);
6857 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
6859 t = build (code, type, tem,
6860 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
6862 /* arg1 should be the first argument of the new T. */
6863 arg1 = TREE_OPERAND (t, 1);
6868 /* If we have A op B ? A : C, we may be able to convert this to a
6869 simpler expression, depending on the operation and the values
6870 of B and C. IEEE floating point prevents this though,
6871 because A or B might be -0.0 or a NaN. */
6873 if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
6874 && (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
6875 || ! FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 0)))
6877 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
6878 arg1, TREE_OPERAND (arg0, 1)))
6880 tree arg2 = TREE_OPERAND (t, 2);
6881 enum tree_code comp_code = TREE_CODE (arg0);
6885 /* If we have A op 0 ? A : -A, this is A, -A, abs (A), or abs (-A),
6886 depending on the comparison operation. */
6887 if ((FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 1)))
6888 ? real_zerop (TREE_OPERAND (arg0, 1))
6889 : integer_zerop (TREE_OPERAND (arg0, 1)))
6890 && TREE_CODE (arg2) == NEGATE_EXPR
6891 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
6896 pedantic_non_lvalue (convert (type, negate_expr (arg1)));
6898 return pedantic_non_lvalue (convert (type, arg1));
6901 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
6902 arg1 = convert (signed_type (TREE_TYPE (arg1)), arg1);
6903 return pedantic_non_lvalue
6904 (convert (type, fold (build1 (ABS_EXPR,
6905 TREE_TYPE (arg1), arg1))));
6908 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
6909 arg1 = convert (signed_type (TREE_TYPE (arg1)), arg1);
6910 return pedantic_non_lvalue
6911 (negate_expr (convert (type,
6912 fold (build1 (ABS_EXPR,
6919 /* If this is A != 0 ? A : 0, this is simply A. For ==, it is
6922 if (integer_zerop (TREE_OPERAND (arg0, 1)) && integer_zerop (arg2))
6924 if (comp_code == NE_EXPR)
6925 return pedantic_non_lvalue (convert (type, arg1));
6926 else if (comp_code == EQ_EXPR)
6927 return pedantic_non_lvalue (convert (type, integer_zero_node));
6930 /* If this is A op B ? A : B, this is either A, B, min (A, B),
6931 or max (A, B), depending on the operation. */
6933 if (operand_equal_for_comparison_p (TREE_OPERAND (arg0, 1),
6934 arg2, TREE_OPERAND (arg0, 0)))
6936 tree comp_op0 = TREE_OPERAND (arg0, 0);
6937 tree comp_op1 = TREE_OPERAND (arg0, 1);
6938 tree comp_type = TREE_TYPE (comp_op0);
6940 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
6941 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
6947 return pedantic_non_lvalue (convert (type, arg2));
6949 return pedantic_non_lvalue (convert (type, arg1));
6952 /* In C++ a ?: expression can be an lvalue, so put the
6953 operand which will be used if they are equal first
6954 so that we can convert this back to the
6955 corresponding COND_EXPR. */
6956 return pedantic_non_lvalue
6957 (convert (type, fold (build (MIN_EXPR, comp_type,
6958 (comp_code == LE_EXPR
6959 ? comp_op0 : comp_op1),
6960 (comp_code == LE_EXPR
6961 ? comp_op1 : comp_op0)))));
6965 return pedantic_non_lvalue
6966 (convert (type, fold (build (MAX_EXPR, comp_type,
6967 (comp_code == GE_EXPR
6968 ? comp_op0 : comp_op1),
6969 (comp_code == GE_EXPR
6970 ? comp_op1 : comp_op0)))));
6977 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
6978 we might still be able to simplify this. For example,
6979 if C1 is one less or one more than C2, this might have started
6980 out as a MIN or MAX and been transformed by this function.
6981 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
6983 if (INTEGRAL_TYPE_P (type)
6984 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6985 && TREE_CODE (arg2) == INTEGER_CST)
6989 /* We can replace A with C1 in this case. */
6990 arg1 = convert (type, TREE_OPERAND (arg0, 1));
6991 t = build (code, type, TREE_OPERAND (t, 0), arg1,
6992 TREE_OPERAND (t, 2));
6996 /* If C1 is C2 + 1, this is min(A, C2). */
6997 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
6998 && operand_equal_p (TREE_OPERAND (arg0, 1),
6999 const_binop (PLUS_EXPR, arg2,
7000 integer_one_node, 0), 1))
7001 return pedantic_non_lvalue
7002 (fold (build (MIN_EXPR, type, arg1, arg2)));
7006 /* If C1 is C2 - 1, this is min(A, C2). */
7007 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
7008 && operand_equal_p (TREE_OPERAND (arg0, 1),
7009 const_binop (MINUS_EXPR, arg2,
7010 integer_one_node, 0), 1))
7011 return pedantic_non_lvalue
7012 (fold (build (MIN_EXPR, type, arg1, arg2)));
7016 /* If C1 is C2 - 1, this is max(A, C2). */
7017 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
7018 && operand_equal_p (TREE_OPERAND (arg0, 1),
7019 const_binop (MINUS_EXPR, arg2,
7020 integer_one_node, 0), 1))
7021 return pedantic_non_lvalue
7022 (fold (build (MAX_EXPR, type, arg1, arg2)));
7026 /* If C1 is C2 + 1, this is max(A, C2). */
7027 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
7028 && operand_equal_p (TREE_OPERAND (arg0, 1),
7029 const_binop (PLUS_EXPR, arg2,
7030 integer_one_node, 0), 1))
7031 return pedantic_non_lvalue
7032 (fold (build (MAX_EXPR, type, arg1, arg2)));
7041 /* If the second operand is simpler than the third, swap them
7042 since that produces better jump optimization results. */
7043 if ((TREE_CONSTANT (arg1) || DECL_P (arg1)
7044 || TREE_CODE (arg1) == SAVE_EXPR)
7045 && ! (TREE_CONSTANT (TREE_OPERAND (t, 2))
7046 || DECL_P (TREE_OPERAND (t, 2))
7047 || TREE_CODE (TREE_OPERAND (t, 2)) == SAVE_EXPR))
7049 /* See if this can be inverted. If it can't, possibly because
7050 it was a floating-point inequality comparison, don't do
7052 tem = invert_truthvalue (arg0);
7054 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
7056 t = build (code, type, tem,
7057 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
7059 /* arg1 should be the first argument of the new T. */
7060 arg1 = TREE_OPERAND (t, 1);
7065 /* Convert A ? 1 : 0 to simply A. */
7066 if (integer_onep (TREE_OPERAND (t, 1))
7067 && integer_zerop (TREE_OPERAND (t, 2))
7068 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
7069 call to fold will try to move the conversion inside
7070 a COND, which will recurse. In that case, the COND_EXPR
7071 is probably the best choice, so leave it alone. */
7072 && type == TREE_TYPE (arg0))
7073 return pedantic_non_lvalue (arg0);
7075 /* Look for expressions of the form A & 2 ? 2 : 0. The result of this
7076 operation is simply A & 2. */
7078 if (integer_zerop (TREE_OPERAND (t, 2))
7079 && TREE_CODE (arg0) == NE_EXPR
7080 && integer_zerop (TREE_OPERAND (arg0, 1))
7081 && integer_pow2p (arg1)
7082 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
7083 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
7085 return pedantic_non_lvalue (convert (type, TREE_OPERAND (arg0, 0)));
7090 /* When pedantic, a compound expression can be neither an lvalue
7091 nor an integer constant expression. */
7092 if (TREE_SIDE_EFFECTS (arg0) || pedantic)
7094 /* Don't let (0, 0) be null pointer constant. */
7095 if (integer_zerop (arg1))
7096 return build1 (NOP_EXPR, type, arg1);
7097 return convert (type, arg1);
7101 return build_complex (type, arg0, arg1);
7105 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7107 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
7108 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
7109 TREE_OPERAND (arg0, 1));
7110 else if (TREE_CODE (arg0) == COMPLEX_CST)
7111 return TREE_REALPART (arg0);
7112 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7113 return fold (build (TREE_CODE (arg0), type,
7114 fold (build1 (REALPART_EXPR, type,
7115 TREE_OPERAND (arg0, 0))),
7116 fold (build1 (REALPART_EXPR,
7117 type, TREE_OPERAND (arg0, 1)))));
7121 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7122 return convert (type, integer_zero_node);
7123 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
7124 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
7125 TREE_OPERAND (arg0, 0));
7126 else if (TREE_CODE (arg0) == COMPLEX_CST)
7127 return TREE_IMAGPART (arg0);
7128 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7129 return fold (build (TREE_CODE (arg0), type,
7130 fold (build1 (IMAGPART_EXPR, type,
7131 TREE_OPERAND (arg0, 0))),
7132 fold (build1 (IMAGPART_EXPR, type,
7133 TREE_OPERAND (arg0, 1)))));
7136 /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
7138 case CLEANUP_POINT_EXPR:
7139 if (! has_cleanups (arg0))
7140 return TREE_OPERAND (t, 0);
7143 enum tree_code code0 = TREE_CODE (arg0);
7144 int kind0 = TREE_CODE_CLASS (code0);
7145 tree arg00 = TREE_OPERAND (arg0, 0);
7148 if (kind0 == '1' || code0 == TRUTH_NOT_EXPR)
7149 return fold (build1 (code0, type,
7150 fold (build1 (CLEANUP_POINT_EXPR,
7151 TREE_TYPE (arg00), arg00))));
7153 if (kind0 == '<' || kind0 == '2'
7154 || code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR
7155 || code0 == TRUTH_AND_EXPR || code0 == TRUTH_OR_EXPR
7156 || code0 == TRUTH_XOR_EXPR)
7158 arg01 = TREE_OPERAND (arg0, 1);
7160 if (TREE_CONSTANT (arg00)
7161 || ((code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR)
7162 && ! has_cleanups (arg00)))
7163 return fold (build (code0, type, arg00,
7164 fold (build1 (CLEANUP_POINT_EXPR,
7165 TREE_TYPE (arg01), arg01))));
7167 if (TREE_CONSTANT (arg01))
7168 return fold (build (code0, type,
7169 fold (build1 (CLEANUP_POINT_EXPR,
7170 TREE_TYPE (arg00), arg00)),
7179 } /* switch (code) */
7182 /* Determine if first argument is a multiple of second argument. Return 0 if
7183 it is not, or we cannot easily determined it to be.
7185 An example of the sort of thing we care about (at this point; this routine
7186 could surely be made more general, and expanded to do what the *_DIV_EXPR's
7187 fold cases do now) is discovering that
7189 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7195 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
7197 This code also handles discovering that
7199 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7201 is a multiple of 8 so we don't have to worry about dealing with a
7204 Note that we *look* inside a SAVE_EXPR only to determine how it was
7205 calculated; it is not safe for fold to do much of anything else with the
7206 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
7207 at run time. For example, the latter example above *cannot* be implemented
7208 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
7209 evaluation time of the original SAVE_EXPR is not necessarily the same at
7210 the time the new expression is evaluated. The only optimization of this
7211 sort that would be valid is changing
7213 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
7217 SAVE_EXPR (I) * SAVE_EXPR (J)
7219 (where the same SAVE_EXPR (J) is used in the original and the
7220 transformed version). */
7223 multiple_of_p (type, top, bottom)
7228 if (operand_equal_p (top, bottom, 0))
7231 if (TREE_CODE (type) != INTEGER_TYPE)
7234 switch (TREE_CODE (top))
7237 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
7238 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
7242 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
7243 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
7246 /* Can't handle conversions from non-integral or wider integral type. */
7247 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
7248 || (TYPE_PRECISION (type)
7249 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
7252 /* .. fall through ... */
7255 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
7258 if ((TREE_CODE (bottom) != INTEGER_CST)
7259 || (tree_int_cst_sgn (top) < 0)
7260 || (tree_int_cst_sgn (bottom) < 0))
7262 return integer_zerop (const_binop (TRUNC_MOD_EXPR,