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 /* Pass the constant down and see if we can make a simplification. If
4401 we can, replace this expression with the inner simplification for
4402 possible later conversion to our or some other type. */
4403 if (0 != (t1 = extract_muldiv (op0, convert (TREE_TYPE (op0), c), code,
4404 code == MULT_EXPR ? ctype : NULL_TREE)))
4408 case NEGATE_EXPR: case ABS_EXPR:
4409 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4410 return fold (build1 (tcode, ctype, convert (ctype, t1)));
4413 case MIN_EXPR: case MAX_EXPR:
4414 /* If widening the type changes the signedness, then we can't perform
4415 this optimization as that changes the result. */
4416 if (ctype != type && TREE_UNSIGNED (ctype) != TREE_UNSIGNED (type))
4419 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
4420 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0
4421 && (t2 = extract_muldiv (op1, c, code, wide_type)) != 0)
4423 if (tree_int_cst_sgn (c) < 0)
4424 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
4426 return fold (build (tcode, ctype, convert (ctype, t1),
4427 convert (ctype, t2)));
4431 case WITH_RECORD_EXPR:
4432 if ((t1 = extract_muldiv (TREE_OPERAND (t, 0), c, code, wide_type)) != 0)
4433 return build (WITH_RECORD_EXPR, TREE_TYPE (t1), t1,
4434 TREE_OPERAND (t, 1));
4438 /* If this has not been evaluated and the operand has no side effects,
4439 we can see if we can do something inside it and make a new one.
4440 Note that this test is overly conservative since we can do this
4441 if the only reason it had side effects is that it was another
4442 similar SAVE_EXPR, but that isn't worth bothering with. */
4443 if (SAVE_EXPR_RTL (t) == 0 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0))
4444 && 0 != (t1 = extract_muldiv (TREE_OPERAND (t, 0), c, code,
4446 return save_expr (t1);
4449 case LSHIFT_EXPR: case RSHIFT_EXPR:
4450 /* If the second operand is constant, this is a multiplication
4451 or floor division, by a power of two, so we can treat it that
4452 way unless the multiplier or divisor overflows. */
4453 if (TREE_CODE (op1) == INTEGER_CST
4454 /* const_binop may not detect overflow correctly,
4455 so check for it explicitly here. */
4456 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
4457 && TREE_INT_CST_HIGH (op1) == 0
4458 && 0 != (t1 = convert (ctype,
4459 const_binop (LSHIFT_EXPR, size_one_node,
4461 && ! TREE_OVERFLOW (t1))
4462 return extract_muldiv (build (tcode == LSHIFT_EXPR
4463 ? MULT_EXPR : FLOOR_DIV_EXPR,
4464 ctype, convert (ctype, op0), t1),
4465 c, code, wide_type);
4468 case PLUS_EXPR: case MINUS_EXPR:
4469 /* See if we can eliminate the operation on both sides. If we can, we
4470 can return a new PLUS or MINUS. If we can't, the only remaining
4471 cases where we can do anything are if the second operand is a
4473 t1 = extract_muldiv (op0, c, code, wide_type);
4474 t2 = extract_muldiv (op1, c, code, wide_type);
4475 if (t1 != 0 && t2 != 0)
4476 return fold (build (tcode, ctype, convert (ctype, t1),
4477 convert (ctype, t2)));
4479 /* If this was a subtraction, negate OP1 and set it to be an addition.
4480 This simplifies the logic below. */
4481 if (tcode == MINUS_EXPR)
4482 tcode = PLUS_EXPR, op1 = negate_expr (op1);
4484 if (TREE_CODE (op1) != INTEGER_CST)
4487 /* If either OP1 or C are negative, this optimization is not safe for
4488 some of the division and remainder types while for others we need
4489 to change the code. */
4490 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
4492 if (code == CEIL_DIV_EXPR)
4493 code = FLOOR_DIV_EXPR;
4494 else if (code == CEIL_MOD_EXPR)
4495 code = FLOOR_MOD_EXPR;
4496 else if (code == FLOOR_DIV_EXPR)
4497 code = CEIL_DIV_EXPR;
4498 else if (code == FLOOR_MOD_EXPR)
4499 code = CEIL_MOD_EXPR;
4500 else if (code != MULT_EXPR)
4504 /* If it's a multiply or a division/modulus operation of a multiple
4505 of our constant, do the operation and verify it doesn't overflow. */
4506 if (code == MULT_EXPR
4507 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4509 op1 = const_binop (code, convert (ctype, op1), convert (ctype, c), 0);
4510 if (op1 == 0 || TREE_OVERFLOW (op1))
4516 /* If we have an unsigned type is not a sizetype, we cannot widen
4517 the operation since it will change the result if the original
4518 computation overflowed. */
4519 if (TREE_UNSIGNED (ctype)
4520 && ! TYPE_IS_SIZETYPE (ctype)
4524 /* If we were able to eliminate our operation from the first side,
4525 apply our operation to the second side and reform the PLUS. */
4526 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
4527 return fold (build (tcode, ctype, convert (ctype, t1), op1));
4529 /* The last case is if we are a multiply. In that case, we can
4530 apply the distributive law to commute the multiply and addition
4531 if the multiplication of the constants doesn't overflow. */
4532 if (code == MULT_EXPR)
4533 return fold (build (tcode, ctype, fold (build (code, ctype,
4534 convert (ctype, op0),
4535 convert (ctype, c))),
4541 /* We have a special case here if we are doing something like
4542 (C * 8) % 4 since we know that's zero. */
4543 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
4544 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
4545 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
4546 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4547 return omit_one_operand (type, integer_zero_node, op0);
4549 /* ... fall through ... */
4551 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
4552 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
4553 /* If we can extract our operation from the LHS, do so and return a
4554 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
4555 do something only if the second operand is a constant. */
4557 && (t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4558 return fold (build (tcode, ctype, convert (ctype, t1),
4559 convert (ctype, op1)));
4560 else if (tcode == MULT_EXPR && code == MULT_EXPR
4561 && (t1 = extract_muldiv (op1, c, code, wide_type)) != 0)
4562 return fold (build (tcode, ctype, convert (ctype, op0),
4563 convert (ctype, t1)));
4564 else if (TREE_CODE (op1) != INTEGER_CST)
4567 /* If these are the same operation types, we can associate them
4568 assuming no overflow. */
4570 && 0 != (t1 = const_binop (MULT_EXPR, convert (ctype, op1),
4571 convert (ctype, c), 0))
4572 && ! TREE_OVERFLOW (t1))
4573 return fold (build (tcode, ctype, convert (ctype, op0), t1));
4575 /* If these operations "cancel" each other, we have the main
4576 optimizations of this pass, which occur when either constant is a
4577 multiple of the other, in which case we replace this with either an
4578 operation or CODE or TCODE.
4580 If we have an unsigned type that is not a sizetype, we canot do
4581 this since it will change the result if the original computation
4583 if ((! TREE_UNSIGNED (ctype)
4584 || (TREE_CODE (ctype) == INTEGER_TYPE
4585 && TYPE_IS_SIZETYPE (ctype)))
4586 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
4587 || (tcode == MULT_EXPR
4588 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
4589 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR)))
4591 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4592 return fold (build (tcode, ctype, convert (ctype, op0),
4594 const_binop (TRUNC_DIV_EXPR,
4596 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
4597 return fold (build (code, ctype, convert (ctype, op0),
4599 const_binop (TRUNC_DIV_EXPR,
4611 /* If T contains a COMPOUND_EXPR which was inserted merely to evaluate
4612 S, a SAVE_EXPR, return the expression actually being evaluated. Note
4613 that we may sometimes modify the tree. */
4616 strip_compound_expr (t, s)
4620 enum tree_code code = TREE_CODE (t);
4622 /* See if this is the COMPOUND_EXPR we want to eliminate. */
4623 if (code == COMPOUND_EXPR && TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR
4624 && TREE_OPERAND (TREE_OPERAND (t, 0), 0) == s)
4625 return TREE_OPERAND (t, 1);
4627 /* See if this is a COND_EXPR or a simple arithmetic operator. We
4628 don't bother handling any other types. */
4629 else if (code == COND_EXPR)
4631 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4632 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4633 TREE_OPERAND (t, 2) = strip_compound_expr (TREE_OPERAND (t, 2), s);
4635 else if (TREE_CODE_CLASS (code) == '1')
4636 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4637 else if (TREE_CODE_CLASS (code) == '<'
4638 || TREE_CODE_CLASS (code) == '2')
4640 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4641 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4647 /* Return a node which has the indicated constant VALUE (either 0 or
4648 1), and is of the indicated TYPE. */
4651 constant_boolean_node (value, type)
4655 if (type == integer_type_node)
4656 return value ? integer_one_node : integer_zero_node;
4657 else if (TREE_CODE (type) == BOOLEAN_TYPE)
4658 return truthvalue_conversion (value ? integer_one_node :
4662 tree t = build_int_2 (value, 0);
4664 TREE_TYPE (t) = type;
4669 /* Utility function for the following routine, to see how complex a nesting of
4670 COND_EXPRs can be. EXPR is the expression and LIMIT is a count beyond which
4671 we don't care (to avoid spending too much time on complex expressions.). */
4674 count_cond (expr, lim)
4680 if (TREE_CODE (expr) != COND_EXPR)
4685 true = count_cond (TREE_OPERAND (expr, 1), lim - 1);
4686 false = count_cond (TREE_OPERAND (expr, 2), lim - 1 - true);
4687 return MIN (lim, 1 + true + false);
4690 /* Perform constant folding and related simplification of EXPR.
4691 The related simplifications include x*1 => x, x*0 => 0, etc.,
4692 and application of the associative law.
4693 NOP_EXPR conversions may be removed freely (as long as we
4694 are careful not to change the C type of the overall expression)
4695 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
4696 but we can constant-fold them if they have constant operands. */
4702 register tree t = expr;
4703 tree t1 = NULL_TREE;
4705 tree type = TREE_TYPE (expr);
4706 register tree arg0 = NULL_TREE, arg1 = NULL_TREE;
4707 register enum tree_code code = TREE_CODE (t);
4710 /* WINS will be nonzero when the switch is done
4711 if all operands are constant. */
4714 /* Don't try to process an RTL_EXPR since its operands aren't trees.
4715 Likewise for a SAVE_EXPR that's already been evaluated. */
4716 if (code == RTL_EXPR || (code == SAVE_EXPR && SAVE_EXPR_RTL (t)) != 0)
4719 /* Return right away if already constant. */
4720 if (TREE_CONSTANT (t))
4722 if (code == CONST_DECL)
4723 return DECL_INITIAL (t);
4727 #ifdef MAX_INTEGER_COMPUTATION_MODE
4728 check_max_integer_computation_mode (expr);
4731 kind = TREE_CODE_CLASS (code);
4732 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
4736 /* Special case for conversion ops that can have fixed point args. */
4737 arg0 = TREE_OPERAND (t, 0);
4739 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
4741 STRIP_SIGN_NOPS (arg0);
4743 if (arg0 != 0 && TREE_CODE (arg0) == COMPLEX_CST)
4744 subop = TREE_REALPART (arg0);
4748 if (subop != 0 && TREE_CODE (subop) != INTEGER_CST
4749 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
4750 && TREE_CODE (subop) != REAL_CST
4751 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
4753 /* Note that TREE_CONSTANT isn't enough:
4754 static var addresses are constant but we can't
4755 do arithmetic on them. */
4758 else if (IS_EXPR_CODE_CLASS (kind) || kind == 'r')
4760 register int len = TREE_CODE_LENGTH (code);
4762 for (i = 0; i < len; i++)
4764 tree op = TREE_OPERAND (t, i);
4768 continue; /* Valid for CALL_EXPR, at least. */
4770 if (kind == '<' || code == RSHIFT_EXPR)
4772 /* Signedness matters here. Perhaps we can refine this
4774 STRIP_SIGN_NOPS (op);
4777 /* Strip any conversions that don't change the mode. */
4780 if (TREE_CODE (op) == COMPLEX_CST)
4781 subop = TREE_REALPART (op);
4785 if (TREE_CODE (subop) != INTEGER_CST
4786 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
4787 && TREE_CODE (subop) != REAL_CST
4788 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
4790 /* Note that TREE_CONSTANT isn't enough:
4791 static var addresses are constant but we can't
4792 do arithmetic on them. */
4802 /* If this is a commutative operation, and ARG0 is a constant, move it
4803 to ARG1 to reduce the number of tests below. */
4804 if ((code == PLUS_EXPR || code == MULT_EXPR || code == MIN_EXPR
4805 || code == MAX_EXPR || code == BIT_IOR_EXPR || code == BIT_XOR_EXPR
4806 || code == BIT_AND_EXPR)
4807 && (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST))
4809 tem = arg0; arg0 = arg1; arg1 = tem;
4811 tem = TREE_OPERAND (t, 0); TREE_OPERAND (t, 0) = TREE_OPERAND (t, 1);
4812 TREE_OPERAND (t, 1) = tem;
4815 /* Now WINS is set as described above,
4816 ARG0 is the first operand of EXPR,
4817 and ARG1 is the second operand (if it has more than one operand).
4819 First check for cases where an arithmetic operation is applied to a
4820 compound, conditional, or comparison operation. Push the arithmetic
4821 operation inside the compound or conditional to see if any folding
4822 can then be done. Convert comparison to conditional for this purpose.
4823 The also optimizes non-constant cases that used to be done in
4826 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
4827 one of the operands is a comparison and the other is a comparison, a
4828 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
4829 code below would make the expression more complex. Change it to a
4830 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
4831 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
4833 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
4834 || code == EQ_EXPR || code == NE_EXPR)
4835 && ((truth_value_p (TREE_CODE (arg0))
4836 && (truth_value_p (TREE_CODE (arg1))
4837 || (TREE_CODE (arg1) == BIT_AND_EXPR
4838 && integer_onep (TREE_OPERAND (arg1, 1)))))
4839 || (truth_value_p (TREE_CODE (arg1))
4840 && (truth_value_p (TREE_CODE (arg0))
4841 || (TREE_CODE (arg0) == BIT_AND_EXPR
4842 && integer_onep (TREE_OPERAND (arg0, 1)))))))
4844 t = fold (build (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
4845 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
4849 if (code == EQ_EXPR)
4850 t = invert_truthvalue (t);
4855 if (TREE_CODE_CLASS (code) == '1')
4857 if (TREE_CODE (arg0) == COMPOUND_EXPR)
4858 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
4859 fold (build1 (code, type, TREE_OPERAND (arg0, 1))));
4860 else if (TREE_CODE (arg0) == COND_EXPR)
4862 t = fold (build (COND_EXPR, type, TREE_OPERAND (arg0, 0),
4863 fold (build1 (code, type, TREE_OPERAND (arg0, 1))),
4864 fold (build1 (code, type, TREE_OPERAND (arg0, 2)))));
4866 /* If this was a conversion, and all we did was to move into
4867 inside the COND_EXPR, bring it back out. But leave it if
4868 it is a conversion from integer to integer and the
4869 result precision is no wider than a word since such a
4870 conversion is cheap and may be optimized away by combine,
4871 while it couldn't if it were outside the COND_EXPR. Then return
4872 so we don't get into an infinite recursion loop taking the
4873 conversion out and then back in. */
4875 if ((code == NOP_EXPR || code == CONVERT_EXPR
4876 || code == NON_LVALUE_EXPR)
4877 && TREE_CODE (t) == COND_EXPR
4878 && TREE_CODE (TREE_OPERAND (t, 1)) == code
4879 && TREE_CODE (TREE_OPERAND (t, 2)) == code
4880 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))
4881 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 2), 0)))
4882 && ! (INTEGRAL_TYPE_P (TREE_TYPE (t))
4884 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))))
4885 && TYPE_PRECISION (TREE_TYPE (t)) <= BITS_PER_WORD))
4886 t = build1 (code, type,
4888 TREE_TYPE (TREE_OPERAND
4889 (TREE_OPERAND (t, 1), 0)),
4890 TREE_OPERAND (t, 0),
4891 TREE_OPERAND (TREE_OPERAND (t, 1), 0),
4892 TREE_OPERAND (TREE_OPERAND (t, 2), 0)));
4895 else if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<')
4896 return fold (build (COND_EXPR, type, arg0,
4897 fold (build1 (code, type, integer_one_node)),
4898 fold (build1 (code, type, integer_zero_node))));
4900 else if (TREE_CODE_CLASS (code) == '2'
4901 || TREE_CODE_CLASS (code) == '<')
4903 if (TREE_CODE (arg1) == COMPOUND_EXPR)
4904 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
4905 fold (build (code, type,
4906 arg0, TREE_OPERAND (arg1, 1))));
4907 else if ((TREE_CODE (arg1) == COND_EXPR
4908 || (TREE_CODE_CLASS (TREE_CODE (arg1)) == '<'
4909 && TREE_CODE_CLASS (code) != '<'))
4910 && (TREE_CODE (arg0) != COND_EXPR
4911 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
4912 && (! TREE_SIDE_EFFECTS (arg0)
4913 || (global_bindings_p () == 0
4914 && ! contains_placeholder_p (arg0))))
4916 tree test, true_value, false_value;
4917 tree lhs = 0, rhs = 0;
4919 if (TREE_CODE (arg1) == COND_EXPR)
4921 test = TREE_OPERAND (arg1, 0);
4922 true_value = TREE_OPERAND (arg1, 1);
4923 false_value = TREE_OPERAND (arg1, 2);
4927 tree testtype = TREE_TYPE (arg1);
4929 true_value = convert (testtype, integer_one_node);
4930 false_value = convert (testtype, integer_zero_node);
4933 /* If ARG0 is complex we want to make sure we only evaluate
4934 it once. Though this is only required if it is volatile, it
4935 might be more efficient even if it is not. However, if we
4936 succeed in folding one part to a constant, we do not need
4937 to make this SAVE_EXPR. Since we do this optimization
4938 primarily to see if we do end up with constant and this
4939 SAVE_EXPR interferes with later optimizations, suppressing
4940 it when we can is important.
4942 If we are not in a function, we can't make a SAVE_EXPR, so don't
4943 try to do so. Don't try to see if the result is a constant
4944 if an arm is a COND_EXPR since we get exponential behavior
4947 if (TREE_CODE (arg0) != SAVE_EXPR && ! TREE_CONSTANT (arg0)
4948 && global_bindings_p () == 0
4949 && ((TREE_CODE (arg0) != VAR_DECL
4950 && TREE_CODE (arg0) != PARM_DECL)
4951 || TREE_SIDE_EFFECTS (arg0)))
4953 if (TREE_CODE (true_value) != COND_EXPR)
4954 lhs = fold (build (code, type, arg0, true_value));
4956 if (TREE_CODE (false_value) != COND_EXPR)
4957 rhs = fold (build (code, type, arg0, false_value));
4959 if ((lhs == 0 || ! TREE_CONSTANT (lhs))
4960 && (rhs == 0 || !TREE_CONSTANT (rhs)))
4961 arg0 = save_expr (arg0), lhs = rhs = 0;
4965 lhs = fold (build (code, type, arg0, true_value));
4967 rhs = fold (build (code, type, arg0, false_value));
4969 test = fold (build (COND_EXPR, type, test, lhs, rhs));
4971 if (TREE_CODE (arg0) == SAVE_EXPR)
4972 return build (COMPOUND_EXPR, type,
4973 convert (void_type_node, arg0),
4974 strip_compound_expr (test, arg0));
4976 return convert (type, test);
4979 else if (TREE_CODE (arg0) == COMPOUND_EXPR)
4980 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
4981 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
4982 else if ((TREE_CODE (arg0) == COND_EXPR
4983 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
4984 && TREE_CODE_CLASS (code) != '<'))
4985 && (TREE_CODE (arg1) != COND_EXPR
4986 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
4987 && (! TREE_SIDE_EFFECTS (arg1)
4988 || (global_bindings_p () == 0
4989 && ! contains_placeholder_p (arg1))))
4991 tree test, true_value, false_value;
4992 tree lhs = 0, rhs = 0;
4994 if (TREE_CODE (arg0) == COND_EXPR)
4996 test = TREE_OPERAND (arg0, 0);
4997 true_value = TREE_OPERAND (arg0, 1);
4998 false_value = TREE_OPERAND (arg0, 2);
5002 tree testtype = TREE_TYPE (arg0);
5004 true_value = convert (testtype, integer_one_node);
5005 false_value = convert (testtype, integer_zero_node);
5008 if (TREE_CODE (arg1) != SAVE_EXPR && ! TREE_CONSTANT (arg0)
5009 && global_bindings_p () == 0
5010 && ((TREE_CODE (arg1) != VAR_DECL
5011 && TREE_CODE (arg1) != PARM_DECL)
5012 || TREE_SIDE_EFFECTS (arg1)))
5014 if (TREE_CODE (true_value) != COND_EXPR)
5015 lhs = fold (build (code, type, true_value, arg1));
5017 if (TREE_CODE (false_value) != COND_EXPR)
5018 rhs = fold (build (code, type, false_value, arg1));
5020 if ((lhs == 0 || ! TREE_CONSTANT (lhs))
5021 && (rhs == 0 || !TREE_CONSTANT (rhs)))
5022 arg1 = save_expr (arg1), lhs = rhs = 0;
5026 lhs = fold (build (code, type, true_value, arg1));
5029 rhs = fold (build (code, type, false_value, arg1));
5031 test = fold (build (COND_EXPR, type, test, lhs, rhs));
5032 if (TREE_CODE (arg1) == SAVE_EXPR)
5033 return build (COMPOUND_EXPR, type,
5034 convert (void_type_node, arg1),
5035 strip_compound_expr (test, arg1));
5037 return convert (type, test);
5040 else if (TREE_CODE_CLASS (code) == '<'
5041 && TREE_CODE (arg0) == COMPOUND_EXPR)
5042 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5043 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
5044 else if (TREE_CODE_CLASS (code) == '<'
5045 && TREE_CODE (arg1) == COMPOUND_EXPR)
5046 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
5047 fold (build (code, type, arg0, TREE_OPERAND (arg1, 1))));
5059 return fold (DECL_INITIAL (t));
5064 case FIX_TRUNC_EXPR:
5065 /* Other kinds of FIX are not handled properly by fold_convert. */
5067 if (TREE_TYPE (TREE_OPERAND (t, 0)) == TREE_TYPE (t))
5068 return TREE_OPERAND (t, 0);
5070 /* Handle cases of two conversions in a row. */
5071 if (TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
5072 || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR)
5074 tree inside_type = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5075 tree inter_type = TREE_TYPE (TREE_OPERAND (t, 0));
5076 tree final_type = TREE_TYPE (t);
5077 int inside_int = INTEGRAL_TYPE_P (inside_type);
5078 int inside_ptr = POINTER_TYPE_P (inside_type);
5079 int inside_float = FLOAT_TYPE_P (inside_type);
5080 unsigned int inside_prec = TYPE_PRECISION (inside_type);
5081 int inside_unsignedp = TREE_UNSIGNED (inside_type);
5082 int inter_int = INTEGRAL_TYPE_P (inter_type);
5083 int inter_ptr = POINTER_TYPE_P (inter_type);
5084 int inter_float = FLOAT_TYPE_P (inter_type);
5085 unsigned int inter_prec = TYPE_PRECISION (inter_type);
5086 int inter_unsignedp = TREE_UNSIGNED (inter_type);
5087 int final_int = INTEGRAL_TYPE_P (final_type);
5088 int final_ptr = POINTER_TYPE_P (final_type);
5089 int final_float = FLOAT_TYPE_P (final_type);
5090 unsigned int final_prec = TYPE_PRECISION (final_type);
5091 int final_unsignedp = TREE_UNSIGNED (final_type);
5093 /* In addition to the cases of two conversions in a row
5094 handled below, if we are converting something to its own
5095 type via an object of identical or wider precision, neither
5096 conversion is needed. */
5097 if (inside_type == final_type
5098 && ((inter_int && final_int) || (inter_float && final_float))
5099 && inter_prec >= final_prec)
5100 return TREE_OPERAND (TREE_OPERAND (t, 0), 0);
5102 /* Likewise, if the intermediate and final types are either both
5103 float or both integer, we don't need the middle conversion if
5104 it is wider than the final type and doesn't change the signedness
5105 (for integers). Avoid this if the final type is a pointer
5106 since then we sometimes need the inner conversion. Likewise if
5107 the outer has a precision not equal to the size of its mode. */
5108 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
5109 || (inter_float && inside_float))
5110 && inter_prec >= inside_prec
5111 && (inter_float || inter_unsignedp == inside_unsignedp)
5112 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
5113 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
5115 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5117 /* If we have a sign-extension of a zero-extended value, we can
5118 replace that by a single zero-extension. */
5119 if (inside_int && inter_int && final_int
5120 && inside_prec < inter_prec && inter_prec < final_prec
5121 && inside_unsignedp && !inter_unsignedp)
5122 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5124 /* Two conversions in a row are not needed unless:
5125 - some conversion is floating-point (overstrict for now), or
5126 - the intermediate type is narrower than both initial and
5128 - the intermediate type and innermost type differ in signedness,
5129 and the outermost type is wider than the intermediate, or
5130 - the initial type is a pointer type and the precisions of the
5131 intermediate and final types differ, or
5132 - the final type is a pointer type and the precisions of the
5133 initial and intermediate types differ. */
5134 if (! inside_float && ! inter_float && ! final_float
5135 && (inter_prec > inside_prec || inter_prec > final_prec)
5136 && ! (inside_int && inter_int
5137 && inter_unsignedp != inside_unsignedp
5138 && inter_prec < final_prec)
5139 && ((inter_unsignedp && inter_prec > inside_prec)
5140 == (final_unsignedp && final_prec > inter_prec))
5141 && ! (inside_ptr && inter_prec != final_prec)
5142 && ! (final_ptr && inside_prec != inter_prec)
5143 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
5144 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
5146 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5149 if (TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR
5150 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t, 0), 1))
5151 /* Detect assigning a bitfield. */
5152 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) == COMPONENT_REF
5153 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 1))))
5155 /* Don't leave an assignment inside a conversion
5156 unless assigning a bitfield. */
5157 tree prev = TREE_OPERAND (t, 0);
5158 TREE_OPERAND (t, 0) = TREE_OPERAND (prev, 1);
5159 /* First do the assignment, then return converted constant. */
5160 t = build (COMPOUND_EXPR, TREE_TYPE (t), prev, fold (t));
5166 TREE_CONSTANT (t) = TREE_CONSTANT (arg0);
5169 return fold_convert (t, arg0);
5171 #if 0 /* This loses on &"foo"[0]. */
5176 /* Fold an expression like: "foo"[2] */
5177 if (TREE_CODE (arg0) == STRING_CST
5178 && TREE_CODE (arg1) == INTEGER_CST
5179 && compare_tree_int (arg1, TREE_STRING_LENGTH (arg0)) < 0)
5181 t = build_int_2 (TREE_STRING_POINTER (arg0)[TREE_INT_CST_LOW (arg))], 0);
5182 TREE_TYPE (t) = TREE_TYPE (TREE_TYPE (arg0));
5183 force_fit_type (t, 0);
5190 if (TREE_CODE (arg0) == CONSTRUCTOR)
5192 tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0));
5199 TREE_CONSTANT (t) = wins;
5205 if (TREE_CODE (arg0) == INTEGER_CST)
5207 unsigned HOST_WIDE_INT low;
5209 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
5210 TREE_INT_CST_HIGH (arg0),
5212 t = build_int_2 (low, high);
5213 TREE_TYPE (t) = type;
5215 = (TREE_OVERFLOW (arg0)
5216 | force_fit_type (t, overflow && !TREE_UNSIGNED (type)));
5217 TREE_CONSTANT_OVERFLOW (t)
5218 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
5220 else if (TREE_CODE (arg0) == REAL_CST)
5221 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
5223 else if (TREE_CODE (arg0) == NEGATE_EXPR)
5224 return TREE_OPERAND (arg0, 0);
5226 /* Convert - (a - b) to (b - a) for non-floating-point. */
5227 else if (TREE_CODE (arg0) == MINUS_EXPR
5228 && (! FLOAT_TYPE_P (type) || flag_fast_math))
5229 return build (MINUS_EXPR, type, TREE_OPERAND (arg0, 1),
5230 TREE_OPERAND (arg0, 0));
5237 if (TREE_CODE (arg0) == INTEGER_CST)
5239 if (! TREE_UNSIGNED (type)
5240 && TREE_INT_CST_HIGH (arg0) < 0)
5242 unsigned HOST_WIDE_INT low;
5244 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
5245 TREE_INT_CST_HIGH (arg0),
5247 t = build_int_2 (low, high);
5248 TREE_TYPE (t) = type;
5250 = (TREE_OVERFLOW (arg0)
5251 | force_fit_type (t, overflow));
5252 TREE_CONSTANT_OVERFLOW (t)
5253 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
5256 else if (TREE_CODE (arg0) == REAL_CST)
5258 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
5259 t = build_real (type,
5260 REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
5263 else if (TREE_CODE (arg0) == ABS_EXPR || TREE_CODE (arg0) == NEGATE_EXPR)
5264 return build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0));
5268 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
5269 return convert (type, arg0);
5270 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
5271 return build (COMPLEX_EXPR, type,
5272 TREE_OPERAND (arg0, 0),
5273 negate_expr (TREE_OPERAND (arg0, 1)));
5274 else if (TREE_CODE (arg0) == COMPLEX_CST)
5275 return build_complex (type, TREE_OPERAND (arg0, 0),
5276 negate_expr (TREE_OPERAND (arg0, 1)));
5277 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
5278 return fold (build (TREE_CODE (arg0), type,
5279 fold (build1 (CONJ_EXPR, type,
5280 TREE_OPERAND (arg0, 0))),
5281 fold (build1 (CONJ_EXPR,
5282 type, TREE_OPERAND (arg0, 1)))));
5283 else if (TREE_CODE (arg0) == CONJ_EXPR)
5284 return TREE_OPERAND (arg0, 0);
5290 t = build_int_2 (~ TREE_INT_CST_LOW (arg0),
5291 ~ TREE_INT_CST_HIGH (arg0));
5292 TREE_TYPE (t) = type;
5293 force_fit_type (t, 0);
5294 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg0);
5295 TREE_CONSTANT_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (arg0);
5297 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
5298 return TREE_OPERAND (arg0, 0);
5302 /* A + (-B) -> A - B */
5303 if (TREE_CODE (arg1) == NEGATE_EXPR)
5304 return fold (build (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5305 /* (-A) + B -> B - A */
5306 if (TREE_CODE (arg0) == NEGATE_EXPR)
5307 return fold (build (MINUS_EXPR, type, arg1, TREE_OPERAND (arg0, 0)));
5308 else if (! FLOAT_TYPE_P (type))
5310 if (integer_zerop (arg1))
5311 return non_lvalue (convert (type, arg0));
5313 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
5314 with a constant, and the two constants have no bits in common,
5315 we should treat this as a BIT_IOR_EXPR since this may produce more
5317 if (TREE_CODE (arg0) == BIT_AND_EXPR
5318 && TREE_CODE (arg1) == BIT_AND_EXPR
5319 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5320 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
5321 && integer_zerop (const_binop (BIT_AND_EXPR,
5322 TREE_OPERAND (arg0, 1),
5323 TREE_OPERAND (arg1, 1), 0)))
5325 code = BIT_IOR_EXPR;
5329 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
5330 (plus (plus (mult) (mult)) (foo)) so that we can
5331 take advantage of the factoring cases below. */
5332 if ((TREE_CODE (arg0) == PLUS_EXPR
5333 && TREE_CODE (arg1) == MULT_EXPR)
5334 || (TREE_CODE (arg1) == PLUS_EXPR
5335 && TREE_CODE (arg0) == MULT_EXPR))
5337 tree parg0, parg1, parg, marg;
5339 if (TREE_CODE (arg0) == PLUS_EXPR)
5340 parg = arg0, marg = arg1;
5342 parg = arg1, marg = arg0;
5343 parg0 = TREE_OPERAND (parg, 0);
5344 parg1 = TREE_OPERAND (parg, 1);
5348 if (TREE_CODE (parg0) == MULT_EXPR
5349 && TREE_CODE (parg1) != MULT_EXPR)
5350 return fold (build (PLUS_EXPR, type,
5351 fold (build (PLUS_EXPR, type, parg0, marg)),
5353 if (TREE_CODE (parg0) != MULT_EXPR
5354 && TREE_CODE (parg1) == MULT_EXPR)
5355 return fold (build (PLUS_EXPR, type,
5356 fold (build (PLUS_EXPR, type, parg1, marg)),
5360 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR)
5362 tree arg00, arg01, arg10, arg11;
5363 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
5365 /* (A * C) + (B * C) -> (A+B) * C.
5366 We are most concerned about the case where C is a constant,
5367 but other combinations show up during loop reduction. Since
5368 it is not difficult, try all four possibilities. */
5370 arg00 = TREE_OPERAND (arg0, 0);
5371 arg01 = TREE_OPERAND (arg0, 1);
5372 arg10 = TREE_OPERAND (arg1, 0);
5373 arg11 = TREE_OPERAND (arg1, 1);
5376 if (operand_equal_p (arg01, arg11, 0))
5377 same = arg01, alt0 = arg00, alt1 = arg10;
5378 else if (operand_equal_p (arg00, arg10, 0))
5379 same = arg00, alt0 = arg01, alt1 = arg11;
5380 else if (operand_equal_p (arg00, arg11, 0))
5381 same = arg00, alt0 = arg01, alt1 = arg10;
5382 else if (operand_equal_p (arg01, arg10, 0))
5383 same = arg01, alt0 = arg00, alt1 = arg11;
5385 /* No identical multiplicands; see if we can find a common
5386 power-of-two factor in non-power-of-two multiplies. This
5387 can help in multi-dimensional array access. */
5388 else if (TREE_CODE (arg01) == INTEGER_CST
5389 && TREE_CODE (arg11) == INTEGER_CST
5390 && TREE_INT_CST_HIGH (arg01) == 0
5391 && TREE_INT_CST_HIGH (arg11) == 0)
5393 HOST_WIDE_INT int01, int11, tmp;
5394 int01 = TREE_INT_CST_LOW (arg01);
5395 int11 = TREE_INT_CST_LOW (arg11);
5397 /* Move min of absolute values to int11. */
5398 if ((int01 >= 0 ? int01 : -int01)
5399 < (int11 >= 0 ? int11 : -int11))
5401 tmp = int01, int01 = int11, int11 = tmp;
5402 alt0 = arg00, arg00 = arg10, arg10 = alt0;
5403 alt0 = arg01, arg01 = arg11, arg11 = alt0;
5406 if (exact_log2 (int11) > 0 && int01 % int11 == 0)
5408 alt0 = fold (build (MULT_EXPR, type, arg00,
5409 build_int_2 (int01 / int11, 0)));
5416 return fold (build (MULT_EXPR, type,
5417 fold (build (PLUS_EXPR, type, alt0, alt1)),
5421 /* In IEEE floating point, x+0 may not equal x. */
5422 else if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
5424 && real_zerop (arg1))
5425 return non_lvalue (convert (type, arg0));
5426 /* x+(-0) equals x, even for IEEE. */
5427 else if (TREE_CODE (arg1) == REAL_CST
5428 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (arg1)))
5429 return non_lvalue (convert (type, arg0));
5432 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
5433 is a rotate of A by C1 bits. */
5434 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
5435 is a rotate of A by B bits. */
5437 register enum tree_code code0, code1;
5438 code0 = TREE_CODE (arg0);
5439 code1 = TREE_CODE (arg1);
5440 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
5441 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
5442 && operand_equal_p (TREE_OPERAND (arg0, 0),
5443 TREE_OPERAND (arg1,0), 0)
5444 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5446 register tree tree01, tree11;
5447 register enum tree_code code01, code11;
5449 tree01 = TREE_OPERAND (arg0, 1);
5450 tree11 = TREE_OPERAND (arg1, 1);
5451 STRIP_NOPS (tree01);
5452 STRIP_NOPS (tree11);
5453 code01 = TREE_CODE (tree01);
5454 code11 = TREE_CODE (tree11);
5455 if (code01 == INTEGER_CST
5456 && code11 == INTEGER_CST
5457 && TREE_INT_CST_HIGH (tree01) == 0
5458 && TREE_INT_CST_HIGH (tree11) == 0
5459 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
5460 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
5461 return build (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
5462 code0 == LSHIFT_EXPR ? tree01 : tree11);
5463 else if (code11 == MINUS_EXPR)
5465 tree tree110, tree111;
5466 tree110 = TREE_OPERAND (tree11, 0);
5467 tree111 = TREE_OPERAND (tree11, 1);
5468 STRIP_NOPS (tree110);
5469 STRIP_NOPS (tree111);
5470 if (TREE_CODE (tree110) == INTEGER_CST
5471 && 0 == compare_tree_int (tree110,
5473 (TREE_TYPE (TREE_OPERAND
5475 && operand_equal_p (tree01, tree111, 0))
5476 return build ((code0 == LSHIFT_EXPR
5479 type, TREE_OPERAND (arg0, 0), tree01);
5481 else if (code01 == MINUS_EXPR)
5483 tree tree010, tree011;
5484 tree010 = TREE_OPERAND (tree01, 0);
5485 tree011 = TREE_OPERAND (tree01, 1);
5486 STRIP_NOPS (tree010);
5487 STRIP_NOPS (tree011);
5488 if (TREE_CODE (tree010) == INTEGER_CST
5489 && 0 == compare_tree_int (tree010,
5491 (TREE_TYPE (TREE_OPERAND
5493 && operand_equal_p (tree11, tree011, 0))
5494 return build ((code0 != LSHIFT_EXPR
5497 type, TREE_OPERAND (arg0, 0), tree11);
5504 /* In most languages, can't associate operations on floats through
5505 parentheses. Rather than remember where the parentheses were, we
5506 don't associate floats at all. It shouldn't matter much. However,
5507 associating multiplications is only very slightly inaccurate, so do
5508 that if -ffast-math is specified. */
5511 && (! FLOAT_TYPE_P (type)
5512 || (flag_fast_math && code != MULT_EXPR)))
5514 tree var0, con0, lit0, var1, con1, lit1;
5516 /* Split both trees into variables, constants, and literals. Then
5517 associate each group together, the constants with literals,
5518 then the result with variables. This increases the chances of
5519 literals being recombined later and of generating relocatable
5520 expressions for the sum of a constant and literal. */
5521 var0 = split_tree (arg0, code, &con0, &lit0, 0);
5522 var1 = split_tree (arg1, code, &con1, &lit1, code == MINUS_EXPR);
5524 /* Only do something if we found more than two objects. Otherwise,
5525 nothing has changed and we risk infinite recursion. */
5526 if (2 < ((var0 != 0) + (var1 != 0) + (con0 != 0) + (con1 != 0)
5527 + (lit0 != 0) + (lit1 != 0)))
5529 var0 = associate_trees (var0, var1, code, type);
5530 con0 = associate_trees (con0, con1, code, type);
5531 lit0 = associate_trees (lit0, lit1, code, type);
5532 con0 = associate_trees (con0, lit0, code, type);
5533 return convert (type, associate_trees (var0, con0, code, type));
5538 #if defined (REAL_IS_NOT_DOUBLE) && ! defined (REAL_ARITHMETIC)
5539 if (TREE_CODE (arg1) == REAL_CST)
5541 #endif /* REAL_IS_NOT_DOUBLE, and no REAL_ARITHMETIC */
5543 t1 = const_binop (code, arg0, arg1, 0);
5544 if (t1 != NULL_TREE)
5546 /* The return value should always have
5547 the same type as the original expression. */
5548 if (TREE_TYPE (t1) != TREE_TYPE (t))
5549 t1 = convert (TREE_TYPE (t), t1);
5556 /* A - (-B) -> A + B */
5557 if (TREE_CODE (arg1) == NEGATE_EXPR)
5558 return fold (build (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5559 /* (-A) - CST -> (-CST) - A for floating point (what about ints ?) */
5560 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == REAL_CST)
5562 fold (build (MINUS_EXPR, type,
5563 build_real (TREE_TYPE (arg1),
5564 REAL_VALUE_NEGATE (TREE_REAL_CST (arg1))),
5565 TREE_OPERAND (arg0, 0)));
5567 if (! FLOAT_TYPE_P (type))
5569 if (! wins && integer_zerop (arg0))
5570 return convert (type, negate_expr (arg1));
5571 if (integer_zerop (arg1))
5572 return non_lvalue (convert (type, arg0));
5574 /* (A * C) - (B * C) -> (A-B) * C. Since we are most concerned
5575 about the case where C is a constant, just try one of the
5576 four possibilities. */
5578 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR
5579 && operand_equal_p (TREE_OPERAND (arg0, 1),
5580 TREE_OPERAND (arg1, 1), 0))
5581 return fold (build (MULT_EXPR, type,
5582 fold (build (MINUS_EXPR, type,
5583 TREE_OPERAND (arg0, 0),
5584 TREE_OPERAND (arg1, 0))),
5585 TREE_OPERAND (arg0, 1)));
5588 else if (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
5591 /* Except with IEEE floating point, 0-x equals -x. */
5592 if (! wins && real_zerop (arg0))
5593 return convert (type, negate_expr (arg1));
5594 /* Except with IEEE floating point, x-0 equals x. */
5595 if (real_zerop (arg1))
5596 return non_lvalue (convert (type, arg0));
5599 /* Fold &x - &x. This can happen from &x.foo - &x.
5600 This is unsafe for certain floats even in non-IEEE formats.
5601 In IEEE, it is unsafe because it does wrong for NaNs.
5602 Also note that operand_equal_p is always false if an operand
5605 if ((! FLOAT_TYPE_P (type) || flag_fast_math)
5606 && operand_equal_p (arg0, arg1, 0))
5607 return convert (type, integer_zero_node);
5612 /* (-A) * (-B) -> A * B */
5613 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR)
5614 return fold (build (MULT_EXPR, type, TREE_OPERAND (arg0, 0),
5615 TREE_OPERAND (arg1, 0)));
5617 if (! FLOAT_TYPE_P (type))
5619 if (integer_zerop (arg1))
5620 return omit_one_operand (type, arg1, arg0);
5621 if (integer_onep (arg1))
5622 return non_lvalue (convert (type, arg0));
5624 /* (a * (1 << b)) is (a << b) */
5625 if (TREE_CODE (arg1) == LSHIFT_EXPR
5626 && integer_onep (TREE_OPERAND (arg1, 0)))
5627 return fold (build (LSHIFT_EXPR, type, arg0,
5628 TREE_OPERAND (arg1, 1)));
5629 if (TREE_CODE (arg0) == LSHIFT_EXPR
5630 && integer_onep (TREE_OPERAND (arg0, 0)))
5631 return fold (build (LSHIFT_EXPR, type, arg1,
5632 TREE_OPERAND (arg0, 1)));
5634 if (TREE_CODE (arg1) == INTEGER_CST
5635 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
5637 return convert (type, tem);
5642 /* x*0 is 0, except for IEEE floating point. */
5643 if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
5645 && real_zerop (arg1))
5646 return omit_one_operand (type, arg1, arg0);
5647 /* In IEEE floating point, x*1 is not equivalent to x for snans.
5648 However, ANSI says we can drop signals,
5649 so we can do this anyway. */
5650 if (real_onep (arg1))
5651 return non_lvalue (convert (type, arg0));
5653 if (! wins && real_twop (arg1) && global_bindings_p () == 0
5654 && ! contains_placeholder_p (arg0))
5656 tree arg = save_expr (arg0);
5657 return build (PLUS_EXPR, type, arg, arg);
5664 if (integer_all_onesp (arg1))
5665 return omit_one_operand (type, arg1, arg0);
5666 if (integer_zerop (arg1))
5667 return non_lvalue (convert (type, arg0));
5668 t1 = distribute_bit_expr (code, type, arg0, arg1);
5669 if (t1 != NULL_TREE)
5672 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
5674 This results in more efficient code for machines without a NAND
5675 instruction. Combine will canonicalize to the first form
5676 which will allow use of NAND instructions provided by the
5677 backend if they exist. */
5678 if (TREE_CODE (arg0) == BIT_NOT_EXPR
5679 && TREE_CODE (arg1) == BIT_NOT_EXPR)
5681 return fold (build1 (BIT_NOT_EXPR, type,
5682 build (BIT_AND_EXPR, type,
5683 TREE_OPERAND (arg0, 0),
5684 TREE_OPERAND (arg1, 0))));
5687 /* See if this can be simplified into a rotate first. If that
5688 is unsuccessful continue in the association code. */
5692 if (integer_zerop (arg1))
5693 return non_lvalue (convert (type, arg0));
5694 if (integer_all_onesp (arg1))
5695 return fold (build1 (BIT_NOT_EXPR, type, arg0));
5697 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
5698 with a constant, and the two constants have no bits in common,
5699 we should treat this as a BIT_IOR_EXPR since this may produce more
5701 if (TREE_CODE (arg0) == BIT_AND_EXPR
5702 && TREE_CODE (arg1) == BIT_AND_EXPR
5703 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5704 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
5705 && integer_zerop (const_binop (BIT_AND_EXPR,
5706 TREE_OPERAND (arg0, 1),
5707 TREE_OPERAND (arg1, 1), 0)))
5709 code = BIT_IOR_EXPR;
5713 /* See if this can be simplified into a rotate first. If that
5714 is unsuccessful continue in the association code. */
5719 if (integer_all_onesp (arg1))
5720 return non_lvalue (convert (type, arg0));
5721 if (integer_zerop (arg1))
5722 return omit_one_operand (type, arg1, arg0);
5723 t1 = distribute_bit_expr (code, type, arg0, arg1);
5724 if (t1 != NULL_TREE)
5726 /* Simplify ((int)c & 0x377) into (int)c, if c is unsigned char. */
5727 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == NOP_EXPR
5728 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg1, 0))))
5731 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg1, 0)));
5733 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
5734 && (~TREE_INT_CST_LOW (arg0)
5735 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
5736 return build1 (NOP_EXPR, type, TREE_OPERAND (arg1, 0));
5738 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
5739 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5742 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
5744 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
5745 && (~TREE_INT_CST_LOW (arg1)
5746 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
5747 return build1 (NOP_EXPR, type, TREE_OPERAND (arg0, 0));
5750 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
5752 This results in more efficient code for machines without a NOR
5753 instruction. Combine will canonicalize to the first form
5754 which will allow use of NOR instructions provided by the
5755 backend if they exist. */
5756 if (TREE_CODE (arg0) == BIT_NOT_EXPR
5757 && TREE_CODE (arg1) == BIT_NOT_EXPR)
5759 return fold (build1 (BIT_NOT_EXPR, type,
5760 build (BIT_IOR_EXPR, type,
5761 TREE_OPERAND (arg0, 0),
5762 TREE_OPERAND (arg1, 0))));
5767 case BIT_ANDTC_EXPR:
5768 if (integer_all_onesp (arg0))
5769 return non_lvalue (convert (type, arg1));
5770 if (integer_zerop (arg0))
5771 return omit_one_operand (type, arg0, arg1);
5772 if (TREE_CODE (arg1) == INTEGER_CST)
5774 arg1 = fold (build1 (BIT_NOT_EXPR, type, arg1));
5775 code = BIT_AND_EXPR;
5781 /* In most cases, do nothing with a divide by zero. */
5782 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
5783 #ifndef REAL_INFINITY
5784 if (TREE_CODE (arg1) == REAL_CST && real_zerop (arg1))
5787 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
5789 /* (-A) / (-B) -> A / B */
5790 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR)
5791 return fold (build (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
5792 TREE_OPERAND (arg1, 0)));
5794 /* In IEEE floating point, x/1 is not equivalent to x for snans.
5795 However, ANSI says we can drop signals, so we can do this anyway. */
5796 if (real_onep (arg1))
5797 return non_lvalue (convert (type, arg0));
5799 /* If ARG1 is a constant, we can convert this to a multiply by the
5800 reciprocal. This does not have the same rounding properties,
5801 so only do this if -ffast-math. We can actually always safely
5802 do it if ARG1 is a power of two, but it's hard to tell if it is
5803 or not in a portable manner. */
5804 if (TREE_CODE (arg1) == REAL_CST)
5807 && 0 != (tem = const_binop (code, build_real (type, dconst1),
5809 return fold (build (MULT_EXPR, type, arg0, tem));
5810 /* Find the reciprocal if optimizing and the result is exact. */
5814 r = TREE_REAL_CST (arg1);
5815 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
5817 tem = build_real (type, r);
5818 return fold (build (MULT_EXPR, type, arg0, tem));
5824 case TRUNC_DIV_EXPR:
5825 case ROUND_DIV_EXPR:
5826 case FLOOR_DIV_EXPR:
5828 case EXACT_DIV_EXPR:
5829 if (integer_onep (arg1))
5830 return non_lvalue (convert (type, arg0));
5831 if (integer_zerop (arg1))
5834 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
5835 operation, EXACT_DIV_EXPR.
5837 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
5838 At one time others generated faster code, it's not clear if they do
5839 after the last round to changes to the DIV code in expmed.c. */
5840 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
5841 && multiple_of_p (type, arg0, arg1))
5842 return fold (build (EXACT_DIV_EXPR, type, arg0, arg1));
5844 if (TREE_CODE (arg1) == INTEGER_CST
5845 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
5847 return convert (type, tem);
5852 case FLOOR_MOD_EXPR:
5853 case ROUND_MOD_EXPR:
5854 case TRUNC_MOD_EXPR:
5855 if (integer_onep (arg1))
5856 return omit_one_operand (type, integer_zero_node, arg0);
5857 if (integer_zerop (arg1))
5860 if (TREE_CODE (arg1) == INTEGER_CST
5861 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
5863 return convert (type, tem);
5871 if (integer_zerop (arg1))
5872 return non_lvalue (convert (type, arg0));
5873 /* Since negative shift count is not well-defined,
5874 don't try to compute it in the compiler. */
5875 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
5877 /* Rewrite an LROTATE_EXPR by a constant into an
5878 RROTATE_EXPR by a new constant. */
5879 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
5881 TREE_SET_CODE (t, RROTATE_EXPR);
5882 code = RROTATE_EXPR;
5883 TREE_OPERAND (t, 1) = arg1
5886 convert (TREE_TYPE (arg1),
5887 build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type)), 0)),
5889 if (tree_int_cst_sgn (arg1) < 0)
5893 /* If we have a rotate of a bit operation with the rotate count and
5894 the second operand of the bit operation both constant,
5895 permute the two operations. */
5896 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
5897 && (TREE_CODE (arg0) == BIT_AND_EXPR
5898 || TREE_CODE (arg0) == BIT_ANDTC_EXPR
5899 || TREE_CODE (arg0) == BIT_IOR_EXPR
5900 || TREE_CODE (arg0) == BIT_XOR_EXPR)
5901 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
5902 return fold (build (TREE_CODE (arg0), type,
5903 fold (build (code, type,
5904 TREE_OPERAND (arg0, 0), arg1)),
5905 fold (build (code, type,
5906 TREE_OPERAND (arg0, 1), arg1))));
5908 /* Two consecutive rotates adding up to the width of the mode can
5910 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
5911 && TREE_CODE (arg0) == RROTATE_EXPR
5912 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5913 && TREE_INT_CST_HIGH (arg1) == 0
5914 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
5915 && ((TREE_INT_CST_LOW (arg1)
5916 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
5917 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type))))
5918 return TREE_OPERAND (arg0, 0);
5923 if (operand_equal_p (arg0, arg1, 0))
5924 return omit_one_operand (type, arg0, arg1);
5925 if (INTEGRAL_TYPE_P (type)
5926 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), 1))
5927 return omit_one_operand (type, arg1, arg0);
5931 if (operand_equal_p (arg0, arg1, 0))
5932 return omit_one_operand (type, arg0, arg1);
5933 if (INTEGRAL_TYPE_P (type)
5934 && TYPE_MAX_VALUE (type)
5935 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), 1))
5936 return omit_one_operand (type, arg1, arg0);
5939 case TRUTH_NOT_EXPR:
5940 /* Note that the operand of this must be an int
5941 and its values must be 0 or 1.
5942 ("true" is a fixed value perhaps depending on the language,
5943 but we don't handle values other than 1 correctly yet.) */
5944 tem = invert_truthvalue (arg0);
5945 /* Avoid infinite recursion. */
5946 if (TREE_CODE (tem) == TRUTH_NOT_EXPR)
5948 return convert (type, tem);
5950 case TRUTH_ANDIF_EXPR:
5951 /* Note that the operands of this must be ints
5952 and their values must be 0 or 1.
5953 ("true" is a fixed value perhaps depending on the language.) */
5954 /* If first arg is constant zero, return it. */
5955 if (integer_zerop (arg0))
5956 return convert (type, arg0);
5957 case TRUTH_AND_EXPR:
5958 /* If either arg is constant true, drop it. */
5959 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
5960 return non_lvalue (convert (type, arg1));
5961 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
5962 return non_lvalue (convert (type, arg0));
5963 /* If second arg is constant zero, result is zero, but first arg
5964 must be evaluated. */
5965 if (integer_zerop (arg1))
5966 return omit_one_operand (type, arg1, arg0);
5967 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
5968 case will be handled here. */
5969 if (integer_zerop (arg0))
5970 return omit_one_operand (type, arg0, arg1);
5973 /* We only do these simplifications if we are optimizing. */
5977 /* Check for things like (A || B) && (A || C). We can convert this
5978 to A || (B && C). Note that either operator can be any of the four
5979 truth and/or operations and the transformation will still be
5980 valid. Also note that we only care about order for the
5981 ANDIF and ORIF operators. If B contains side effects, this
5982 might change the truth-value of A. */
5983 if (TREE_CODE (arg0) == TREE_CODE (arg1)
5984 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
5985 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
5986 || TREE_CODE (arg0) == TRUTH_AND_EXPR
5987 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
5988 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
5990 tree a00 = TREE_OPERAND (arg0, 0);
5991 tree a01 = TREE_OPERAND (arg0, 1);
5992 tree a10 = TREE_OPERAND (arg1, 0);
5993 tree a11 = TREE_OPERAND (arg1, 1);
5994 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
5995 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
5996 && (code == TRUTH_AND_EXPR
5997 || code == TRUTH_OR_EXPR));
5999 if (operand_equal_p (a00, a10, 0))
6000 return fold (build (TREE_CODE (arg0), type, a00,
6001 fold (build (code, type, a01, a11))));
6002 else if (commutative && operand_equal_p (a00, a11, 0))
6003 return fold (build (TREE_CODE (arg0), type, a00,
6004 fold (build (code, type, a01, a10))));
6005 else if (commutative && operand_equal_p (a01, a10, 0))
6006 return fold (build (TREE_CODE (arg0), type, a01,
6007 fold (build (code, type, a00, a11))));
6009 /* This case if tricky because we must either have commutative
6010 operators or else A10 must not have side-effects. */
6012 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
6013 && operand_equal_p (a01, a11, 0))
6014 return fold (build (TREE_CODE (arg0), type,
6015 fold (build (code, type, a00, a10)),
6019 /* See if we can build a range comparison. */
6020 if (0 != (tem = fold_range_test (t)))
6023 /* Check for the possibility of merging component references. If our
6024 lhs is another similar operation, try to merge its rhs with our
6025 rhs. Then try to merge our lhs and rhs. */
6026 if (TREE_CODE (arg0) == code
6027 && 0 != (tem = fold_truthop (code, type,
6028 TREE_OPERAND (arg0, 1), arg1)))
6029 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6031 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
6036 case TRUTH_ORIF_EXPR:
6037 /* Note that the operands of this must be ints
6038 and their values must be 0 or true.
6039 ("true" is a fixed value perhaps depending on the language.) */
6040 /* If first arg is constant true, return it. */
6041 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
6042 return convert (type, arg0);
6044 /* If either arg is constant zero, drop it. */
6045 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
6046 return non_lvalue (convert (type, arg1));
6047 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1))
6048 return non_lvalue (convert (type, arg0));
6049 /* If second arg is constant true, result is true, but we must
6050 evaluate first arg. */
6051 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
6052 return omit_one_operand (type, arg1, arg0);
6053 /* Likewise for first arg, but note this only occurs here for
6055 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
6056 return omit_one_operand (type, arg0, arg1);
6059 case TRUTH_XOR_EXPR:
6060 /* If either arg is constant zero, drop it. */
6061 if (integer_zerop (arg0))
6062 return non_lvalue (convert (type, arg1));
6063 if (integer_zerop (arg1))
6064 return non_lvalue (convert (type, arg0));
6065 /* If either arg is constant true, this is a logical inversion. */
6066 if (integer_onep (arg0))
6067 return non_lvalue (convert (type, invert_truthvalue (arg1)));
6068 if (integer_onep (arg1))
6069 return non_lvalue (convert (type, invert_truthvalue (arg0)));
6078 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
6080 /* (-a) CMP (-b) -> b CMP a */
6081 if (TREE_CODE (arg0) == NEGATE_EXPR
6082 && TREE_CODE (arg1) == NEGATE_EXPR)
6083 return fold (build (code, type, TREE_OPERAND (arg1, 0),
6084 TREE_OPERAND (arg0, 0)));
6085 /* (-a) CMP CST -> a swap(CMP) (-CST) */
6086 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == REAL_CST)
6089 (swap_tree_comparison (code), type,
6090 TREE_OPERAND (arg0, 0),
6091 build_real (TREE_TYPE (arg1),
6092 REAL_VALUE_NEGATE (TREE_REAL_CST (arg1)))));
6093 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
6094 /* a CMP (-0) -> a CMP 0 */
6095 if (TREE_CODE (arg1) == REAL_CST
6096 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (arg1)))
6097 return fold (build (code, type, arg0,
6098 build_real (TREE_TYPE (arg1), dconst0)));
6102 /* If one arg is a constant integer, put it last. */
6103 if (TREE_CODE (arg0) == INTEGER_CST
6104 && TREE_CODE (arg1) != INTEGER_CST)
6106 TREE_OPERAND (t, 0) = arg1;
6107 TREE_OPERAND (t, 1) = arg0;
6108 arg0 = TREE_OPERAND (t, 0);
6109 arg1 = TREE_OPERAND (t, 1);
6110 code = swap_tree_comparison (code);
6111 TREE_SET_CODE (t, code);
6114 /* Convert foo++ == CONST into ++foo == CONST + INCR.
6115 First, see if one arg is constant; find the constant arg
6116 and the other one. */
6118 tree constop = 0, varop = NULL_TREE;
6119 int constopnum = -1;
6121 if (TREE_CONSTANT (arg1))
6122 constopnum = 1, constop = arg1, varop = arg0;
6123 if (TREE_CONSTANT (arg0))
6124 constopnum = 0, constop = arg0, varop = arg1;
6126 if (constop && TREE_CODE (varop) == POSTINCREMENT_EXPR)
6128 /* This optimization is invalid for ordered comparisons
6129 if CONST+INCR overflows or if foo+incr might overflow.
6130 This optimization is invalid for floating point due to rounding.
6131 For pointer types we assume overflow doesn't happen. */
6132 if (POINTER_TYPE_P (TREE_TYPE (varop))
6133 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
6134 && (code == EQ_EXPR || code == NE_EXPR)))
6137 = fold (build (PLUS_EXPR, TREE_TYPE (varop),
6138 constop, TREE_OPERAND (varop, 1)));
6139 TREE_SET_CODE (varop, PREINCREMENT_EXPR);
6141 /* If VAROP is a reference to a bitfield, we must mask
6142 the constant by the width of the field. */
6143 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
6144 && DECL_BIT_FIELD(TREE_OPERAND
6145 (TREE_OPERAND (varop, 0), 1)))
6148 = TREE_INT_CST_LOW (DECL_SIZE
6150 (TREE_OPERAND (varop, 0), 1)));
6151 tree mask, unsigned_type;
6152 unsigned int precision;
6153 tree folded_compare;
6155 /* First check whether the comparison would come out
6156 always the same. If we don't do that we would
6157 change the meaning with the masking. */
6158 if (constopnum == 0)
6159 folded_compare = fold (build (code, type, constop,
6160 TREE_OPERAND (varop, 0)));
6162 folded_compare = fold (build (code, type,
6163 TREE_OPERAND (varop, 0),
6165 if (integer_zerop (folded_compare)
6166 || integer_onep (folded_compare))
6167 return omit_one_operand (type, folded_compare, varop);
6169 unsigned_type = type_for_size (size, 1);
6170 precision = TYPE_PRECISION (unsigned_type);
6171 mask = build_int_2 (~0, ~0);
6172 TREE_TYPE (mask) = unsigned_type;
6173 force_fit_type (mask, 0);
6174 mask = const_binop (RSHIFT_EXPR, mask,
6175 size_int (precision - size), 0);
6176 newconst = fold (build (BIT_AND_EXPR,
6177 TREE_TYPE (varop), newconst,
6178 convert (TREE_TYPE (varop),
6183 t = build (code, type, TREE_OPERAND (t, 0),
6184 TREE_OPERAND (t, 1));
6185 TREE_OPERAND (t, constopnum) = newconst;
6189 else if (constop && TREE_CODE (varop) == POSTDECREMENT_EXPR)
6191 if (POINTER_TYPE_P (TREE_TYPE (varop))
6192 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
6193 && (code == EQ_EXPR || code == NE_EXPR)))
6196 = fold (build (MINUS_EXPR, TREE_TYPE (varop),
6197 constop, TREE_OPERAND (varop, 1)));
6198 TREE_SET_CODE (varop, PREDECREMENT_EXPR);
6200 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
6201 && DECL_BIT_FIELD(TREE_OPERAND
6202 (TREE_OPERAND (varop, 0), 1)))
6205 = TREE_INT_CST_LOW (DECL_SIZE
6207 (TREE_OPERAND (varop, 0), 1)));
6208 tree mask, unsigned_type;
6209 unsigned int precision;
6210 tree folded_compare;
6212 if (constopnum == 0)
6213 folded_compare = fold (build (code, type, constop,
6214 TREE_OPERAND (varop, 0)));
6216 folded_compare = fold (build (code, type,
6217 TREE_OPERAND (varop, 0),
6219 if (integer_zerop (folded_compare)
6220 || integer_onep (folded_compare))
6221 return omit_one_operand (type, folded_compare, varop);
6223 unsigned_type = type_for_size (size, 1);
6224 precision = TYPE_PRECISION (unsigned_type);
6225 mask = build_int_2 (~0, ~0);
6226 TREE_TYPE (mask) = TREE_TYPE (varop);
6227 force_fit_type (mask, 0);
6228 mask = const_binop (RSHIFT_EXPR, mask,
6229 size_int (precision - size), 0);
6230 newconst = fold (build (BIT_AND_EXPR,
6231 TREE_TYPE (varop), newconst,
6232 convert (TREE_TYPE (varop),
6237 t = build (code, type, TREE_OPERAND (t, 0),
6238 TREE_OPERAND (t, 1));
6239 TREE_OPERAND (t, constopnum) = newconst;
6245 /* Change X >= CST to X > (CST - 1) if CST is positive. */
6246 if (TREE_CODE (arg1) == INTEGER_CST
6247 && TREE_CODE (arg0) != INTEGER_CST
6248 && tree_int_cst_sgn (arg1) > 0)
6250 switch (TREE_CODE (t))
6254 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6255 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6260 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6261 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6269 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
6270 a MINUS_EXPR of a constant, we can convert it into a comparison with
6271 a revised constant as long as no overflow occurs. */
6272 if ((code == EQ_EXPR || code == NE_EXPR)
6273 && TREE_CODE (arg1) == INTEGER_CST
6274 && (TREE_CODE (arg0) == PLUS_EXPR
6275 || TREE_CODE (arg0) == MINUS_EXPR)
6276 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6277 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
6278 ? MINUS_EXPR : PLUS_EXPR,
6279 arg1, TREE_OPERAND (arg0, 1), 0))
6280 && ! TREE_CONSTANT_OVERFLOW (tem))
6281 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6283 /* Similarly for a NEGATE_EXPR. */
6284 else if ((code == EQ_EXPR || code == NE_EXPR)
6285 && TREE_CODE (arg0) == NEGATE_EXPR
6286 && TREE_CODE (arg1) == INTEGER_CST
6287 && 0 != (tem = negate_expr (arg1))
6288 && TREE_CODE (tem) == INTEGER_CST
6289 && ! TREE_CONSTANT_OVERFLOW (tem))
6290 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6292 /* If we have X - Y == 0, we can convert that to X == Y and similarly
6293 for !=. Don't do this for ordered comparisons due to overflow. */
6294 else if ((code == NE_EXPR || code == EQ_EXPR)
6295 && integer_zerop (arg1) && TREE_CODE (arg0) == MINUS_EXPR)
6296 return fold (build (code, type,
6297 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1)));
6299 /* If we are widening one operand of an integer comparison,
6300 see if the other operand is similarly being widened. Perhaps we
6301 can do the comparison in the narrower type. */
6302 else if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
6303 && TREE_CODE (arg0) == NOP_EXPR
6304 && (tem = get_unwidened (arg0, NULL_TREE)) != arg0
6305 && (t1 = get_unwidened (arg1, TREE_TYPE (tem))) != 0
6306 && (TREE_TYPE (t1) == TREE_TYPE (tem)
6307 || (TREE_CODE (t1) == INTEGER_CST
6308 && int_fits_type_p (t1, TREE_TYPE (tem)))))
6309 return fold (build (code, type, tem, convert (TREE_TYPE (tem), t1)));
6311 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
6312 constant, we can simplify it. */
6313 else if (TREE_CODE (arg1) == INTEGER_CST
6314 && (TREE_CODE (arg0) == MIN_EXPR
6315 || TREE_CODE (arg0) == MAX_EXPR)
6316 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
6317 return optimize_minmax_comparison (t);
6319 /* If we are comparing an ABS_EXPR with a constant, we can
6320 convert all the cases into explicit comparisons, but they may
6321 well not be faster than doing the ABS and one comparison.
6322 But ABS (X) <= C is a range comparison, which becomes a subtraction
6323 and a comparison, and is probably faster. */
6324 else if (code == LE_EXPR && TREE_CODE (arg1) == INTEGER_CST
6325 && TREE_CODE (arg0) == ABS_EXPR
6326 && ! TREE_SIDE_EFFECTS (arg0)
6327 && (0 != (tem = negate_expr (arg1)))
6328 && TREE_CODE (tem) == INTEGER_CST
6329 && ! TREE_CONSTANT_OVERFLOW (tem))
6330 return fold (build (TRUTH_ANDIF_EXPR, type,
6331 build (GE_EXPR, type, TREE_OPERAND (arg0, 0), tem),
6332 build (LE_EXPR, type,
6333 TREE_OPERAND (arg0, 0), arg1)));
6335 /* If this is an EQ or NE comparison with zero and ARG0 is
6336 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
6337 two operations, but the latter can be done in one less insn
6338 on machines that have only two-operand insns or on which a
6339 constant cannot be the first operand. */
6340 if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR)
6341 && TREE_CODE (arg0) == BIT_AND_EXPR)
6343 if (TREE_CODE (TREE_OPERAND (arg0, 0)) == LSHIFT_EXPR
6344 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 0), 0)))
6346 fold (build (code, type,
6347 build (BIT_AND_EXPR, TREE_TYPE (arg0),
6349 TREE_TYPE (TREE_OPERAND (arg0, 0)),
6350 TREE_OPERAND (arg0, 1),
6351 TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)),
6352 convert (TREE_TYPE (arg0),
6355 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
6356 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
6358 fold (build (code, type,
6359 build (BIT_AND_EXPR, TREE_TYPE (arg0),
6361 TREE_TYPE (TREE_OPERAND (arg0, 1)),
6362 TREE_OPERAND (arg0, 0),
6363 TREE_OPERAND (TREE_OPERAND (arg0, 1), 1)),
6364 convert (TREE_TYPE (arg0),
6369 /* If this is an NE or EQ comparison of zero against the result of a
6370 signed MOD operation whose second operand is a power of 2, make
6371 the MOD operation unsigned since it is simpler and equivalent. */
6372 if ((code == NE_EXPR || code == EQ_EXPR)
6373 && integer_zerop (arg1)
6374 && ! TREE_UNSIGNED (TREE_TYPE (arg0))
6375 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
6376 || TREE_CODE (arg0) == CEIL_MOD_EXPR
6377 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
6378 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
6379 && integer_pow2p (TREE_OPERAND (arg0, 1)))
6381 tree newtype = unsigned_type (TREE_TYPE (arg0));
6382 tree newmod = build (TREE_CODE (arg0), newtype,
6383 convert (newtype, TREE_OPERAND (arg0, 0)),
6384 convert (newtype, TREE_OPERAND (arg0, 1)));
6386 return build (code, type, newmod, convert (newtype, arg1));
6389 /* If this is an NE comparison of zero with an AND of one, remove the
6390 comparison since the AND will give the correct value. */
6391 if (code == NE_EXPR && integer_zerop (arg1)
6392 && TREE_CODE (arg0) == BIT_AND_EXPR
6393 && integer_onep (TREE_OPERAND (arg0, 1)))
6394 return convert (type, arg0);
6396 /* If we have (A & C) == C where C is a power of 2, convert this into
6397 (A & C) != 0. Similarly for NE_EXPR. */
6398 if ((code == EQ_EXPR || code == NE_EXPR)
6399 && TREE_CODE (arg0) == BIT_AND_EXPR
6400 && integer_pow2p (TREE_OPERAND (arg0, 1))
6401 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
6402 return build (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
6403 arg0, integer_zero_node);
6405 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
6406 and similarly for >= into !=. */
6407 if ((code == LT_EXPR || code == GE_EXPR)
6408 && TREE_UNSIGNED (TREE_TYPE (arg0))
6409 && TREE_CODE (arg1) == LSHIFT_EXPR
6410 && integer_onep (TREE_OPERAND (arg1, 0)))
6411 return build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
6412 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
6413 TREE_OPERAND (arg1, 1)),
6414 convert (TREE_TYPE (arg0), integer_zero_node));
6416 else if ((code == LT_EXPR || code == GE_EXPR)
6417 && TREE_UNSIGNED (TREE_TYPE (arg0))
6418 && (TREE_CODE (arg1) == NOP_EXPR
6419 || TREE_CODE (arg1) == CONVERT_EXPR)
6420 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
6421 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
6423 build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
6424 convert (TREE_TYPE (arg0),
6425 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
6426 TREE_OPERAND (TREE_OPERAND (arg1, 0), 1))),
6427 convert (TREE_TYPE (arg0), integer_zero_node));
6429 /* Simplify comparison of something with itself. (For IEEE
6430 floating-point, we can only do some of these simplifications.) */
6431 if (operand_equal_p (arg0, arg1, 0))
6438 if (INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
6439 return constant_boolean_node (1, type);
6441 TREE_SET_CODE (t, code);
6445 /* For NE, we can only do this simplification if integer. */
6446 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
6448 /* ... fall through ... */
6451 return constant_boolean_node (0, type);
6457 /* An unsigned comparison against 0 can be simplified. */
6458 if (integer_zerop (arg1)
6459 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
6460 || POINTER_TYPE_P (TREE_TYPE (arg1)))
6461 && TREE_UNSIGNED (TREE_TYPE (arg1)))
6463 switch (TREE_CODE (t))
6467 TREE_SET_CODE (t, NE_EXPR);
6471 TREE_SET_CODE (t, EQ_EXPR);
6474 return omit_one_operand (type,
6475 convert (type, integer_one_node),
6478 return omit_one_operand (type,
6479 convert (type, integer_zero_node),
6486 /* Comparisons with the highest or lowest possible integer of
6487 the specified size will have known values and an unsigned
6488 <= 0x7fffffff can be simplified. */
6490 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1)));
6492 if (TREE_CODE (arg1) == INTEGER_CST
6493 && ! TREE_CONSTANT_OVERFLOW (arg1)
6494 && width <= HOST_BITS_PER_WIDE_INT
6495 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
6496 || POINTER_TYPE_P (TREE_TYPE (arg1))))
6498 if (TREE_INT_CST_HIGH (arg1) == 0
6499 && (TREE_INT_CST_LOW (arg1)
6500 == ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1)
6501 && ! TREE_UNSIGNED (TREE_TYPE (arg1)))
6502 switch (TREE_CODE (t))
6505 return omit_one_operand (type,
6506 convert (type, integer_zero_node),
6509 TREE_SET_CODE (t, EQ_EXPR);
6513 return omit_one_operand (type,
6514 convert (type, integer_one_node),
6517 TREE_SET_CODE (t, NE_EXPR);
6524 else if (TREE_INT_CST_HIGH (arg1) == -1
6525 && (- TREE_INT_CST_LOW (arg1)
6526 == ((unsigned HOST_WIDE_INT) 1 << (width - 1)))
6527 && ! TREE_UNSIGNED (TREE_TYPE (arg1)))
6528 switch (TREE_CODE (t))
6531 return omit_one_operand (type,
6532 convert (type, integer_zero_node),
6535 TREE_SET_CODE (t, EQ_EXPR);
6539 return omit_one_operand (type,
6540 convert (type, integer_one_node),
6543 TREE_SET_CODE (t, NE_EXPR);
6550 else if (TREE_INT_CST_HIGH (arg1) == 0
6551 && (TREE_INT_CST_LOW (arg1)
6552 == ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1)
6553 && TREE_UNSIGNED (TREE_TYPE (arg1)))
6555 switch (TREE_CODE (t))
6558 return fold (build (GE_EXPR, type,
6559 convert (signed_type (TREE_TYPE (arg0)),
6561 convert (signed_type (TREE_TYPE (arg1)),
6562 integer_zero_node)));
6564 return fold (build (LT_EXPR, type,
6565 convert (signed_type (TREE_TYPE (arg0)),
6567 convert (signed_type (TREE_TYPE (arg1)),
6568 integer_zero_node)));
6576 /* If we are comparing an expression that just has comparisons
6577 of two integer values, arithmetic expressions of those comparisons,
6578 and constants, we can simplify it. There are only three cases
6579 to check: the two values can either be equal, the first can be
6580 greater, or the second can be greater. Fold the expression for
6581 those three values. Since each value must be 0 or 1, we have
6582 eight possibilities, each of which corresponds to the constant 0
6583 or 1 or one of the six possible comparisons.
6585 This handles common cases like (a > b) == 0 but also handles
6586 expressions like ((x > y) - (y > x)) > 0, which supposedly
6587 occur in macroized code. */
6589 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
6591 tree cval1 = 0, cval2 = 0;
6594 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
6595 /* Don't handle degenerate cases here; they should already
6596 have been handled anyway. */
6597 && cval1 != 0 && cval2 != 0
6598 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
6599 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
6600 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
6601 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
6602 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
6603 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
6604 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
6606 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
6607 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
6609 /* We can't just pass T to eval_subst in case cval1 or cval2
6610 was the same as ARG1. */
6613 = fold (build (code, type,
6614 eval_subst (arg0, cval1, maxval, cval2, minval),
6617 = fold (build (code, type,
6618 eval_subst (arg0, cval1, maxval, cval2, maxval),
6621 = fold (build (code, type,
6622 eval_subst (arg0, cval1, minval, cval2, maxval),
6625 /* All three of these results should be 0 or 1. Confirm they
6626 are. Then use those values to select the proper code
6629 if ((integer_zerop (high_result)
6630 || integer_onep (high_result))
6631 && (integer_zerop (equal_result)
6632 || integer_onep (equal_result))
6633 && (integer_zerop (low_result)
6634 || integer_onep (low_result)))
6636 /* Make a 3-bit mask with the high-order bit being the
6637 value for `>', the next for '=', and the low for '<'. */
6638 switch ((integer_onep (high_result) * 4)
6639 + (integer_onep (equal_result) * 2)
6640 + integer_onep (low_result))
6644 return omit_one_operand (type, integer_zero_node, arg0);
6665 return omit_one_operand (type, integer_one_node, arg0);
6668 t = build (code, type, cval1, cval2);
6670 return save_expr (t);
6677 /* If this is a comparison of a field, we may be able to simplify it. */
6678 if ((TREE_CODE (arg0) == COMPONENT_REF
6679 || TREE_CODE (arg0) == BIT_FIELD_REF)
6680 && (code == EQ_EXPR || code == NE_EXPR)
6681 /* Handle the constant case even without -O
6682 to make sure the warnings are given. */
6683 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
6685 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
6689 /* If this is a comparison of complex values and either or both sides
6690 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
6691 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
6692 This may prevent needless evaluations. */
6693 if ((code == EQ_EXPR || code == NE_EXPR)
6694 && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
6695 && (TREE_CODE (arg0) == COMPLEX_EXPR
6696 || TREE_CODE (arg1) == COMPLEX_EXPR
6697 || TREE_CODE (arg0) == COMPLEX_CST
6698 || TREE_CODE (arg1) == COMPLEX_CST))
6700 tree subtype = TREE_TYPE (TREE_TYPE (arg0));
6701 tree real0, imag0, real1, imag1;
6703 arg0 = save_expr (arg0);
6704 arg1 = save_expr (arg1);
6705 real0 = fold (build1 (REALPART_EXPR, subtype, arg0));
6706 imag0 = fold (build1 (IMAGPART_EXPR, subtype, arg0));
6707 real1 = fold (build1 (REALPART_EXPR, subtype, arg1));
6708 imag1 = fold (build1 (IMAGPART_EXPR, subtype, arg1));
6710 return fold (build ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR
6713 fold (build (code, type, real0, real1)),
6714 fold (build (code, type, imag0, imag1))));
6717 /* From here on, the only cases we handle are when the result is
6718 known to be a constant.
6720 To compute GT, swap the arguments and do LT.
6721 To compute GE, do LT and invert the result.
6722 To compute LE, swap the arguments, do LT and invert the result.
6723 To compute NE, do EQ and invert the result.
6725 Therefore, the code below must handle only EQ and LT. */
6727 if (code == LE_EXPR || code == GT_EXPR)
6729 tem = arg0, arg0 = arg1, arg1 = tem;
6730 code = swap_tree_comparison (code);
6733 /* Note that it is safe to invert for real values here because we
6734 will check below in the one case that it matters. */
6738 if (code == NE_EXPR || code == GE_EXPR)
6741 code = invert_tree_comparison (code);
6744 /* Compute a result for LT or EQ if args permit;
6745 otherwise return T. */
6746 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
6748 if (code == EQ_EXPR)
6749 t1 = build_int_2 (tree_int_cst_equal (arg0, arg1), 0);
6751 t1 = build_int_2 ((TREE_UNSIGNED (TREE_TYPE (arg0))
6752 ? INT_CST_LT_UNSIGNED (arg0, arg1)
6753 : INT_CST_LT (arg0, arg1)),
6757 #if 0 /* This is no longer useful, but breaks some real code. */
6758 /* Assume a nonexplicit constant cannot equal an explicit one,
6759 since such code would be undefined anyway.
6760 Exception: on sysvr4, using #pragma weak,
6761 a label can come out as 0. */
6762 else if (TREE_CODE (arg1) == INTEGER_CST
6763 && !integer_zerop (arg1)
6764 && TREE_CONSTANT (arg0)
6765 && TREE_CODE (arg0) == ADDR_EXPR
6767 t1 = build_int_2 (0, 0);
6769 /* Two real constants can be compared explicitly. */
6770 else if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
6772 /* If either operand is a NaN, the result is false with two
6773 exceptions: First, an NE_EXPR is true on NaNs, but that case
6774 is already handled correctly since we will be inverting the
6775 result for NE_EXPR. Second, if we had inverted a LE_EXPR
6776 or a GE_EXPR into a LT_EXPR, we must return true so that it
6777 will be inverted into false. */
6779 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
6780 || REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
6781 t1 = build_int_2 (invert && code == LT_EXPR, 0);
6783 else if (code == EQ_EXPR)
6784 t1 = build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (arg0),
6785 TREE_REAL_CST (arg1)),
6788 t1 = build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (arg0),
6789 TREE_REAL_CST (arg1)),
6793 if (t1 == NULL_TREE)
6797 TREE_INT_CST_LOW (t1) ^= 1;
6799 TREE_TYPE (t1) = type;
6800 if (TREE_CODE (type) == BOOLEAN_TYPE)
6801 return truthvalue_conversion (t1);
6805 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
6806 so all simple results must be passed through pedantic_non_lvalue. */
6807 if (TREE_CODE (arg0) == INTEGER_CST)
6808 return pedantic_non_lvalue
6809 (TREE_OPERAND (t, (integer_zerop (arg0) ? 2 : 1)));
6810 else if (operand_equal_p (arg1, TREE_OPERAND (expr, 2), 0))
6811 return pedantic_omit_one_operand (type, arg1, arg0);
6813 /* If the second operand is zero, invert the comparison and swap
6814 the second and third operands. Likewise if the second operand
6815 is constant and the third is not or if the third operand is
6816 equivalent to the first operand of the comparison. */
6818 if (integer_zerop (arg1)
6819 || (TREE_CONSTANT (arg1) && ! TREE_CONSTANT (TREE_OPERAND (t, 2)))
6820 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
6821 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
6822 TREE_OPERAND (t, 2),
6823 TREE_OPERAND (arg0, 1))))
6825 /* See if this can be inverted. If it can't, possibly because
6826 it was a floating-point inequality comparison, don't do
6828 tem = invert_truthvalue (arg0);
6830 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
6832 t = build (code, type, tem,
6833 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
6835 /* arg1 should be the first argument of the new T. */
6836 arg1 = TREE_OPERAND (t, 1);
6841 /* If we have A op B ? A : C, we may be able to convert this to a
6842 simpler expression, depending on the operation and the values
6843 of B and C. IEEE floating point prevents this though,
6844 because A or B might be -0.0 or a NaN. */
6846 if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
6847 && (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
6848 || ! FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 0)))
6850 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
6851 arg1, TREE_OPERAND (arg0, 1)))
6853 tree arg2 = TREE_OPERAND (t, 2);
6854 enum tree_code comp_code = TREE_CODE (arg0);
6858 /* If we have A op 0 ? A : -A, this is A, -A, abs (A), or abs (-A),
6859 depending on the comparison operation. */
6860 if ((FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 1)))
6861 ? real_zerop (TREE_OPERAND (arg0, 1))
6862 : integer_zerop (TREE_OPERAND (arg0, 1)))
6863 && TREE_CODE (arg2) == NEGATE_EXPR
6864 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
6869 pedantic_non_lvalue (convert (type, negate_expr (arg1)));
6871 return pedantic_non_lvalue (convert (type, arg1));
6874 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
6875 arg1 = convert (signed_type (TREE_TYPE (arg1)), arg1);
6876 return pedantic_non_lvalue
6877 (convert (type, fold (build1 (ABS_EXPR,
6878 TREE_TYPE (arg1), arg1))));
6881 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
6882 arg1 = convert (signed_type (TREE_TYPE (arg1)), arg1);
6883 return pedantic_non_lvalue
6884 (negate_expr (convert (type,
6885 fold (build1 (ABS_EXPR,
6892 /* If this is A != 0 ? A : 0, this is simply A. For ==, it is
6895 if (integer_zerop (TREE_OPERAND (arg0, 1)) && integer_zerop (arg2))
6897 if (comp_code == NE_EXPR)
6898 return pedantic_non_lvalue (convert (type, arg1));
6899 else if (comp_code == EQ_EXPR)
6900 return pedantic_non_lvalue (convert (type, integer_zero_node));
6903 /* If this is A op B ? A : B, this is either A, B, min (A, B),
6904 or max (A, B), depending on the operation. */
6906 if (operand_equal_for_comparison_p (TREE_OPERAND (arg0, 1),
6907 arg2, TREE_OPERAND (arg0, 0)))
6909 tree comp_op0 = TREE_OPERAND (arg0, 0);
6910 tree comp_op1 = TREE_OPERAND (arg0, 1);
6911 tree comp_type = TREE_TYPE (comp_op0);
6913 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
6914 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
6920 return pedantic_non_lvalue (convert (type, arg2));
6922 return pedantic_non_lvalue (convert (type, arg1));
6925 /* In C++ a ?: expression can be an lvalue, so put the
6926 operand which will be used if they are equal first
6927 so that we can convert this back to the
6928 corresponding COND_EXPR. */
6929 return pedantic_non_lvalue
6930 (convert (type, fold (build (MIN_EXPR, comp_type,
6931 (comp_code == LE_EXPR
6932 ? comp_op0 : comp_op1),
6933 (comp_code == LE_EXPR
6934 ? comp_op1 : comp_op0)))));
6938 return pedantic_non_lvalue
6939 (convert (type, fold (build (MAX_EXPR, comp_type,
6940 (comp_code == GE_EXPR
6941 ? comp_op0 : comp_op1),
6942 (comp_code == GE_EXPR
6943 ? comp_op1 : comp_op0)))));
6950 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
6951 we might still be able to simplify this. For example,
6952 if C1 is one less or one more than C2, this might have started
6953 out as a MIN or MAX and been transformed by this function.
6954 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
6956 if (INTEGRAL_TYPE_P (type)
6957 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6958 && TREE_CODE (arg2) == INTEGER_CST)
6962 /* We can replace A with C1 in this case. */
6963 arg1 = convert (type, TREE_OPERAND (arg0, 1));
6964 t = build (code, type, TREE_OPERAND (t, 0), arg1,
6965 TREE_OPERAND (t, 2));
6969 /* If C1 is C2 + 1, this is min(A, C2). */
6970 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
6971 && operand_equal_p (TREE_OPERAND (arg0, 1),
6972 const_binop (PLUS_EXPR, arg2,
6973 integer_one_node, 0), 1))
6974 return pedantic_non_lvalue
6975 (fold (build (MIN_EXPR, type, arg1, arg2)));
6979 /* If C1 is C2 - 1, this is min(A, C2). */
6980 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
6981 && operand_equal_p (TREE_OPERAND (arg0, 1),
6982 const_binop (MINUS_EXPR, arg2,
6983 integer_one_node, 0), 1))
6984 return pedantic_non_lvalue
6985 (fold (build (MIN_EXPR, type, arg1, arg2)));
6989 /* If C1 is C2 - 1, this is max(A, C2). */
6990 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
6991 && operand_equal_p (TREE_OPERAND (arg0, 1),
6992 const_binop (MINUS_EXPR, arg2,
6993 integer_one_node, 0), 1))
6994 return pedantic_non_lvalue
6995 (fold (build (MAX_EXPR, type, arg1, arg2)));
6999 /* If C1 is C2 + 1, this is max(A, C2). */
7000 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
7001 && operand_equal_p (TREE_OPERAND (arg0, 1),
7002 const_binop (PLUS_EXPR, arg2,
7003 integer_one_node, 0), 1))
7004 return pedantic_non_lvalue
7005 (fold (build (MAX_EXPR, type, arg1, arg2)));
7014 /* If the second operand is simpler than the third, swap them
7015 since that produces better jump optimization results. */
7016 if ((TREE_CONSTANT (arg1) || DECL_P (arg1)
7017 || TREE_CODE (arg1) == SAVE_EXPR)
7018 && ! (TREE_CONSTANT (TREE_OPERAND (t, 2))
7019 || DECL_P (TREE_OPERAND (t, 2))
7020 || TREE_CODE (TREE_OPERAND (t, 2)) == SAVE_EXPR))
7022 /* See if this can be inverted. If it can't, possibly because
7023 it was a floating-point inequality comparison, don't do
7025 tem = invert_truthvalue (arg0);
7027 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
7029 t = build (code, type, tem,
7030 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
7032 /* arg1 should be the first argument of the new T. */
7033 arg1 = TREE_OPERAND (t, 1);
7038 /* Convert A ? 1 : 0 to simply A. */
7039 if (integer_onep (TREE_OPERAND (t, 1))
7040 && integer_zerop (TREE_OPERAND (t, 2))
7041 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
7042 call to fold will try to move the conversion inside
7043 a COND, which will recurse. In that case, the COND_EXPR
7044 is probably the best choice, so leave it alone. */
7045 && type == TREE_TYPE (arg0))
7046 return pedantic_non_lvalue (arg0);
7048 /* Look for expressions of the form A & 2 ? 2 : 0. The result of this
7049 operation is simply A & 2. */
7051 if (integer_zerop (TREE_OPERAND (t, 2))
7052 && TREE_CODE (arg0) == NE_EXPR
7053 && integer_zerop (TREE_OPERAND (arg0, 1))
7054 && integer_pow2p (arg1)
7055 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
7056 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
7058 return pedantic_non_lvalue (convert (type, TREE_OPERAND (arg0, 0)));
7063 /* When pedantic, a compound expression can be neither an lvalue
7064 nor an integer constant expression. */
7065 if (TREE_SIDE_EFFECTS (arg0) || pedantic)
7067 /* Don't let (0, 0) be null pointer constant. */
7068 if (integer_zerop (arg1))
7069 return build1 (NOP_EXPR, type, arg1);
7070 return convert (type, arg1);
7074 return build_complex (type, arg0, arg1);
7078 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7080 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
7081 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
7082 TREE_OPERAND (arg0, 1));
7083 else if (TREE_CODE (arg0) == COMPLEX_CST)
7084 return TREE_REALPART (arg0);
7085 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7086 return fold (build (TREE_CODE (arg0), type,
7087 fold (build1 (REALPART_EXPR, type,
7088 TREE_OPERAND (arg0, 0))),
7089 fold (build1 (REALPART_EXPR,
7090 type, TREE_OPERAND (arg0, 1)))));
7094 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7095 return convert (type, integer_zero_node);
7096 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
7097 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
7098 TREE_OPERAND (arg0, 0));
7099 else if (TREE_CODE (arg0) == COMPLEX_CST)
7100 return TREE_IMAGPART (arg0);
7101 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7102 return fold (build (TREE_CODE (arg0), type,
7103 fold (build1 (IMAGPART_EXPR, type,
7104 TREE_OPERAND (arg0, 0))),
7105 fold (build1 (IMAGPART_EXPR, type,
7106 TREE_OPERAND (arg0, 1)))));
7109 /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
7111 case CLEANUP_POINT_EXPR:
7112 if (! has_cleanups (arg0))
7113 return TREE_OPERAND (t, 0);
7116 enum tree_code code0 = TREE_CODE (arg0);
7117 int kind0 = TREE_CODE_CLASS (code0);
7118 tree arg00 = TREE_OPERAND (arg0, 0);
7121 if (kind0 == '1' || code0 == TRUTH_NOT_EXPR)
7122 return fold (build1 (code0, type,
7123 fold (build1 (CLEANUP_POINT_EXPR,
7124 TREE_TYPE (arg00), arg00))));
7126 if (kind0 == '<' || kind0 == '2'
7127 || code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR
7128 || code0 == TRUTH_AND_EXPR || code0 == TRUTH_OR_EXPR
7129 || code0 == TRUTH_XOR_EXPR)
7131 arg01 = TREE_OPERAND (arg0, 1);
7133 if (TREE_CONSTANT (arg00)
7134 || ((code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR)
7135 && ! has_cleanups (arg00)))
7136 return fold (build (code0, type, arg00,
7137 fold (build1 (CLEANUP_POINT_EXPR,
7138 TREE_TYPE (arg01), arg01))));
7140 if (TREE_CONSTANT (arg01))
7141 return fold (build (code0, type,
7142 fold (build1 (CLEANUP_POINT_EXPR,
7143 TREE_TYPE (arg00), arg00)),
7152 } /* switch (code) */
7155 /* Determine if first argument is a multiple of second argument. Return 0 if
7156 it is not, or we cannot easily determined it to be.
7158 An example of the sort of thing we care about (at this point; this routine
7159 could surely be made more general, and expanded to do what the *_DIV_EXPR's
7160 fold cases do now) is discovering that
7162 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7168 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
7170 This code also handles discovering that
7172 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7174 is a multiple of 8 so we don't have to worry about dealing with a
7177 Note that we *look* inside a SAVE_EXPR only to determine how it was
7178 calculated; it is not safe for fold to do much of anything else with the
7179 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
7180 at run time. For example, the latter example above *cannot* be implemented
7181 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
7182 evaluation time of the original SAVE_EXPR is not necessarily the same at
7183 the time the new expression is evaluated. The only optimization of this
7184 sort that would be valid is changing
7186 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
7190 SAVE_EXPR (I) * SAVE_EXPR (J)
7192 (where the same SAVE_EXPR (J) is used in the original and the
7193 transformed version). */
7196 multiple_of_p (type, top, bottom)
7201 if (operand_equal_p (top, bottom, 0))
7204 if (TREE_CODE (type) != INTEGER_TYPE)
7207 switch (TREE_CODE (top))
7210 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
7211 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
7215 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
7216 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
7219 /* Can't handle conversions from non-integral or wider integral type. */
7220 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
7221 || (TYPE_PRECISION (type)
7222 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
7225 /* .. fall through ... */
7228 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
7231 if ((TREE_CODE (bottom) != INTEGER_CST)
7232 || (tree_int_cst_sgn (top) < 0)
7233 || (tree_int_cst_sgn (bottom) < 0))
7235 return integer_zerop (const_binop (TRUNC_MOD_EXPR,