1 /* Fold a constant sub-tree into a single node for C-compiler
2 Copyright (C) 1987, 88, 92-98, 1999 Free Software Foundation, Inc.
4 This file is part of GNU CC.
6 GNU CC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GNU CC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU CC; see the file COPYING. If not, write to
18 the Free Software Foundation, 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
21 /*@@ This file should be rewritten to use an arbitrary precision
22 @@ representation for "struct tree_int_cst" and "struct tree_real_cst".
23 @@ Perhaps the routines could also be used for bc/dc, and made a lib.
24 @@ The routines that translate from the ap rep should
25 @@ warn if precision et. al. is lost.
26 @@ This would also make life easier when this technology is used
27 @@ for cross-compilers. */
30 /* The entry points in this file are fold, size_int_wide, size_binop
33 fold takes a tree as argument and returns a simplified tree.
35 size_binop takes a tree code for an arithmetic operation
36 and two operands that are trees, and produces a tree for the
37 result, assuming the type comes from `sizetype'.
39 size_int takes an integer value, and creates a tree constant
40 with type from `sizetype'.
42 force_fit_type takes a constant and prior overflow indicator, and
43 forces the value to fit the type. It returns an overflow indicator. */
55 static void encode PROTO((HOST_WIDE_INT *,
56 HOST_WIDE_INT, HOST_WIDE_INT));
57 static void decode PROTO((HOST_WIDE_INT *,
58 HOST_WIDE_INT *, HOST_WIDE_INT *));
59 int div_and_round_double PROTO((enum tree_code, int, HOST_WIDE_INT,
60 HOST_WIDE_INT, HOST_WIDE_INT,
61 HOST_WIDE_INT, HOST_WIDE_INT *,
62 HOST_WIDE_INT *, HOST_WIDE_INT *,
64 static tree negate_expr PROTO((tree));
65 static tree split_tree PROTO((tree, enum tree_code, tree *, tree *,
67 static tree associate_trees PROTO((tree, tree, enum tree_code, tree));
68 static tree int_const_binop PROTO((enum tree_code, tree, tree, int, int));
69 static tree const_binop PROTO((enum tree_code, tree, tree, int));
70 static tree fold_convert PROTO((tree, tree));
71 static enum tree_code invert_tree_comparison PROTO((enum tree_code));
72 static enum tree_code swap_tree_comparison PROTO((enum tree_code));
73 static int truth_value_p PROTO((enum tree_code));
74 static int operand_equal_for_comparison_p PROTO((tree, tree, tree));
75 static int twoval_comparison_p PROTO((tree, tree *, tree *, int *));
76 static tree eval_subst PROTO((tree, tree, tree, tree, tree));
77 static tree omit_one_operand PROTO((tree, tree, tree));
78 static tree pedantic_omit_one_operand PROTO((tree, tree, tree));
79 static tree distribute_bit_expr PROTO((enum tree_code, tree, tree, tree));
80 static tree make_bit_field_ref PROTO((tree, tree, int, int, int));
81 static tree optimize_bit_field_compare PROTO((enum tree_code, tree,
83 static tree decode_field_reference PROTO((tree, int *, int *,
84 enum machine_mode *, int *,
85 int *, tree *, tree *));
86 static int all_ones_mask_p PROTO((tree, int));
87 static int simple_operand_p PROTO((tree));
88 static tree range_binop PROTO((enum tree_code, tree, tree, int,
90 static tree make_range PROTO((tree, int *, tree *, tree *));
91 static tree build_range_check PROTO((tree, tree, int, tree, tree));
92 static int merge_ranges PROTO((int *, tree *, tree *, int, tree, tree,
94 static tree fold_range_test PROTO((tree));
95 static tree unextend PROTO((tree, int, int, tree));
96 static tree fold_truthop PROTO((enum tree_code, tree, tree, tree));
97 static tree optimize_minmax_comparison PROTO((tree));
98 static tree extract_muldiv PROTO((tree, tree, enum tree_code, tree));
99 static tree strip_compound_expr PROTO((tree, tree));
100 static int multiple_of_p PROTO((tree, tree, tree));
101 static tree constant_boolean_node PROTO((int, tree));
102 static int count_cond PROTO((tree, int));
103 static void const_binop_1 PROTO((PTR));
104 static void fold_convert_1 PROTO((PTR));
107 #define BRANCH_COST 1
110 /* Suppose A1 + B1 = SUM1, using 2's complement arithmetic ignoring overflow.
111 Suppose A, B and SUM have the same respective signs as A1, B1, and SUM1.
112 Then this yields nonzero if overflow occurred during the addition.
113 Overflow occurs if A and B have the same sign, but A and SUM differ in sign.
114 Use `^' to test whether signs differ, and `< 0' to isolate the sign. */
115 #define overflow_sum_sign(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
117 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
118 We do that by representing the two-word integer in 4 words, with only
119 HOST_BITS_PER_WIDE_INT/2 bits stored in each word, as a positive number. */
122 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT/2)) - 1))
123 #define HIGHPART(x) \
124 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT/2)
125 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT/2)
127 /* Unpack a two-word integer into 4 words.
128 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
129 WORDS points to the array of HOST_WIDE_INTs. */
132 encode (words, low, hi)
133 HOST_WIDE_INT *words;
134 HOST_WIDE_INT low, hi;
136 words[0] = LOWPART (low);
137 words[1] = HIGHPART (low);
138 words[2] = LOWPART (hi);
139 words[3] = HIGHPART (hi);
142 /* Pack an array of 4 words into a two-word integer.
143 WORDS points to the array of words.
144 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
147 decode (words, low, hi)
148 HOST_WIDE_INT *words;
149 HOST_WIDE_INT *low, *hi;
151 *low = words[0] | words[1] * BASE;
152 *hi = words[2] | words[3] * BASE;
155 /* Make the integer constant T valid for its type
156 by setting to 0 or 1 all the bits in the constant
157 that don't belong in the type.
158 Yield 1 if a signed overflow occurs, 0 otherwise.
159 If OVERFLOW is nonzero, a signed overflow has already occurred
160 in calculating T, so propagate it.
162 Make the real constant T valid for its type by calling CHECK_FLOAT_VALUE,
166 force_fit_type (t, overflow)
170 HOST_WIDE_INT low, high;
173 if (TREE_CODE (t) == REAL_CST)
175 #ifdef CHECK_FLOAT_VALUE
176 CHECK_FLOAT_VALUE (TYPE_MODE (TREE_TYPE (t)), TREE_REAL_CST (t),
182 else if (TREE_CODE (t) != INTEGER_CST)
185 low = TREE_INT_CST_LOW (t);
186 high = TREE_INT_CST_HIGH (t);
188 if (POINTER_TYPE_P (TREE_TYPE (t)))
191 prec = TYPE_PRECISION (TREE_TYPE (t));
193 /* First clear all bits that are beyond the type's precision. */
195 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
197 else if (prec > HOST_BITS_PER_WIDE_INT)
199 TREE_INT_CST_HIGH (t)
200 &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
204 TREE_INT_CST_HIGH (t) = 0;
205 if (prec < HOST_BITS_PER_WIDE_INT)
206 TREE_INT_CST_LOW (t) &= ~((HOST_WIDE_INT) (-1) << prec);
209 /* Unsigned types do not suffer sign extension or overflow. */
210 if (TREE_UNSIGNED (TREE_TYPE (t)))
213 /* If the value's sign bit is set, extend the sign. */
214 if (prec != 2 * HOST_BITS_PER_WIDE_INT
215 && (prec > HOST_BITS_PER_WIDE_INT
216 ? (TREE_INT_CST_HIGH (t)
217 & ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)))
218 : TREE_INT_CST_LOW (t) & ((HOST_WIDE_INT) 1 << (prec - 1))))
220 /* Value is negative:
221 set to 1 all the bits that are outside this type's precision. */
222 if (prec > HOST_BITS_PER_WIDE_INT)
224 TREE_INT_CST_HIGH (t)
225 |= ((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
229 TREE_INT_CST_HIGH (t) = -1;
230 if (prec < HOST_BITS_PER_WIDE_INT)
231 TREE_INT_CST_LOW (t) |= ((HOST_WIDE_INT) (-1) << prec);
235 /* Yield nonzero if signed overflow occurred. */
237 ((overflow | (low ^ TREE_INT_CST_LOW (t)) | (high ^ TREE_INT_CST_HIGH (t)))
241 /* Add two doubleword integers with doubleword result.
242 Each argument is given as two `HOST_WIDE_INT' pieces.
243 One argument is L1 and H1; the other, L2 and H2.
244 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
247 add_double (l1, h1, l2, h2, lv, hv)
248 HOST_WIDE_INT l1, h1, l2, h2;
249 HOST_WIDE_INT *lv, *hv;
254 h = h1 + h2 + ((unsigned HOST_WIDE_INT) l < l1);
258 return overflow_sum_sign (h1, h2, h);
261 /* Negate a doubleword integer with doubleword result.
262 Return nonzero if the operation overflows, assuming it's signed.
263 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
264 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
267 neg_double (l1, h1, lv, hv)
268 HOST_WIDE_INT l1, h1;
269 HOST_WIDE_INT *lv, *hv;
275 return (*hv & h1) < 0;
285 /* Multiply two doubleword integers with doubleword result.
286 Return nonzero if the operation overflows, assuming it's signed.
287 Each argument is given as two `HOST_WIDE_INT' pieces.
288 One argument is L1 and H1; the other, L2 and H2.
289 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
292 mul_double (l1, h1, l2, h2, lv, hv)
293 HOST_WIDE_INT l1, h1, l2, h2;
294 HOST_WIDE_INT *lv, *hv;
296 HOST_WIDE_INT arg1[4];
297 HOST_WIDE_INT arg2[4];
298 HOST_WIDE_INT prod[4 * 2];
299 register unsigned HOST_WIDE_INT carry;
300 register int i, j, k;
301 HOST_WIDE_INT toplow, tophigh, neglow, neghigh;
303 encode (arg1, l1, h1);
304 encode (arg2, l2, h2);
306 bzero ((char *) prod, sizeof prod);
308 for (i = 0; i < 4; i++)
311 for (j = 0; j < 4; j++)
314 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
315 carry += arg1[i] * arg2[j];
316 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
318 prod[k] = LOWPART (carry);
319 carry = HIGHPART (carry);
324 decode (prod, lv, hv); /* This ignores prod[4] through prod[4*2-1] */
326 /* Check for overflow by calculating the top half of the answer in full;
327 it should agree with the low half's sign bit. */
328 decode (prod+4, &toplow, &tophigh);
331 neg_double (l2, h2, &neglow, &neghigh);
332 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
336 neg_double (l1, h1, &neglow, &neghigh);
337 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
339 return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
342 /* Shift the doubleword integer in L1, H1 left by COUNT places
343 keeping only PREC bits of result.
344 Shift right if COUNT is negative.
345 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
346 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
349 lshift_double (l1, h1, count, prec, lv, hv, arith)
350 HOST_WIDE_INT l1, h1, count;
352 HOST_WIDE_INT *lv, *hv;
357 rshift_double (l1, h1, - count, prec, lv, hv, arith);
361 #ifdef SHIFT_COUNT_TRUNCATED
362 if (SHIFT_COUNT_TRUNCATED)
366 if (count >= HOST_BITS_PER_WIDE_INT)
368 *hv = (unsigned HOST_WIDE_INT) l1 << (count - HOST_BITS_PER_WIDE_INT);
373 *hv = (((unsigned HOST_WIDE_INT) h1 << count)
374 | ((unsigned HOST_WIDE_INT) l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
375 *lv = (unsigned HOST_WIDE_INT) l1 << count;
379 /* Shift the doubleword integer in L1, H1 right by COUNT places
380 keeping only PREC bits of result. COUNT must be positive.
381 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
382 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
385 rshift_double (l1, h1, count, prec, lv, hv, arith)
386 HOST_WIDE_INT l1, h1, count;
387 int prec ATTRIBUTE_UNUSED;
388 HOST_WIDE_INT *lv, *hv;
391 unsigned HOST_WIDE_INT signmask;
393 ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
396 #ifdef SHIFT_COUNT_TRUNCATED
397 if (SHIFT_COUNT_TRUNCATED)
401 if (count >= HOST_BITS_PER_WIDE_INT)
404 *lv = ((signmask << (2 * HOST_BITS_PER_WIDE_INT - count - 1) << 1)
405 | ((unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT)));
409 *lv = (((unsigned HOST_WIDE_INT) l1 >> count)
410 | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
411 *hv = ((signmask << (HOST_BITS_PER_WIDE_INT - count))
412 | ((unsigned HOST_WIDE_INT) h1 >> count));
416 /* Rotate the doubleword integer in L1, H1 left by COUNT places
417 keeping only PREC bits of result.
418 Rotate right if COUNT is negative.
419 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
422 lrotate_double (l1, h1, count, prec, lv, hv)
423 HOST_WIDE_INT l1, h1, count;
425 HOST_WIDE_INT *lv, *hv;
427 HOST_WIDE_INT s1l, s1h, s2l, s2h;
433 lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
434 rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
439 /* Rotate the doubleword integer in L1, H1 left by COUNT places
440 keeping only PREC bits of result. COUNT must be positive.
441 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
444 rrotate_double (l1, h1, count, prec, lv, hv)
445 HOST_WIDE_INT l1, h1, count;
447 HOST_WIDE_INT *lv, *hv;
449 HOST_WIDE_INT s1l, s1h, s2l, s2h;
455 rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
456 lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
461 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
462 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
463 CODE is a tree code for a kind of division, one of
464 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
466 It controls how the quotient is rounded to a integer.
467 Return nonzero if the operation overflows.
468 UNS nonzero says do unsigned division. */
471 div_and_round_double (code, uns,
472 lnum_orig, hnum_orig, lden_orig, hden_orig,
473 lquo, hquo, lrem, hrem)
476 HOST_WIDE_INT lnum_orig, hnum_orig; /* num == numerator == dividend */
477 HOST_WIDE_INT lden_orig, hden_orig; /* den == denominator == divisor */
478 HOST_WIDE_INT *lquo, *hquo, *lrem, *hrem;
481 HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
482 HOST_WIDE_INT den[4], quo[4];
484 unsigned HOST_WIDE_INT work;
485 register unsigned HOST_WIDE_INT carry = 0;
486 HOST_WIDE_INT lnum = lnum_orig;
487 HOST_WIDE_INT hnum = hnum_orig;
488 HOST_WIDE_INT lden = lden_orig;
489 HOST_WIDE_INT hden = hden_orig;
492 if ((hden == 0) && (lden == 0))
493 overflow = 1, lden = 1;
495 /* calculate quotient sign and convert operands to unsigned. */
501 /* (minimum integer) / (-1) is the only overflow case. */
502 if (neg_double (lnum, hnum, &lnum, &hnum) && (lden & hden) == -1)
508 neg_double (lden, hden, &lden, &hden);
512 if (hnum == 0 && hden == 0)
513 { /* single precision */
515 /* This unsigned division rounds toward zero. */
516 *lquo = lnum / (unsigned HOST_WIDE_INT) lden;
521 { /* trivial case: dividend < divisor */
522 /* hden != 0 already checked. */
529 bzero ((char *) quo, sizeof quo);
531 bzero ((char *) num, sizeof num); /* to zero 9th element */
532 bzero ((char *) den, sizeof den);
534 encode (num, lnum, hnum);
535 encode (den, lden, hden);
537 /* Special code for when the divisor < BASE. */
538 if (hden == 0 && lden < (HOST_WIDE_INT) BASE)
540 /* hnum != 0 already checked. */
541 for (i = 4 - 1; i >= 0; i--)
543 work = num[i] + carry * BASE;
544 quo[i] = work / (unsigned HOST_WIDE_INT) lden;
545 carry = work % (unsigned HOST_WIDE_INT) lden;
550 /* Full double precision division,
551 with thanks to Don Knuth's "Seminumerical Algorithms". */
552 int num_hi_sig, den_hi_sig;
553 unsigned HOST_WIDE_INT quo_est, scale;
555 /* Find the highest non-zero divisor digit. */
556 for (i = 4 - 1; ; i--)
562 /* Insure that the first digit of the divisor is at least BASE/2.
563 This is required by the quotient digit estimation algorithm. */
565 scale = BASE / (den[den_hi_sig] + 1);
566 if (scale > 1) { /* scale divisor and dividend */
568 for (i = 0; i <= 4 - 1; i++) {
569 work = (num[i] * scale) + carry;
570 num[i] = LOWPART (work);
571 carry = HIGHPART (work);
574 for (i = 0; i <= 4 - 1; i++) {
575 work = (den[i] * scale) + carry;
576 den[i] = LOWPART (work);
577 carry = HIGHPART (work);
578 if (den[i] != 0) den_hi_sig = i;
585 for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--) {
586 /* guess the next quotient digit, quo_est, by dividing the first
587 two remaining dividend digits by the high order quotient digit.
588 quo_est is never low and is at most 2 high. */
589 unsigned HOST_WIDE_INT tmp;
591 num_hi_sig = i + den_hi_sig + 1;
592 work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
593 if (num[num_hi_sig] != den[den_hi_sig])
594 quo_est = work / den[den_hi_sig];
598 /* refine quo_est so it's usually correct, and at most one high. */
599 tmp = work - quo_est * den[den_hi_sig];
601 && den[den_hi_sig - 1] * quo_est > (tmp * BASE + num[num_hi_sig - 2]))
604 /* Try QUO_EST as the quotient digit, by multiplying the
605 divisor by QUO_EST and subtracting from the remaining dividend.
606 Keep in mind that QUO_EST is the I - 1st digit. */
609 for (j = 0; j <= den_hi_sig; j++)
611 work = quo_est * den[j] + carry;
612 carry = HIGHPART (work);
613 work = num[i + j] - LOWPART (work);
614 num[i + j] = LOWPART (work);
615 carry += HIGHPART (work) != 0;
618 /* if quo_est was high by one, then num[i] went negative and
619 we need to correct things. */
621 if (num[num_hi_sig] < carry)
624 carry = 0; /* add divisor back in */
625 for (j = 0; j <= den_hi_sig; j++)
627 work = num[i + j] + den[j] + carry;
628 carry = HIGHPART (work);
629 num[i + j] = LOWPART (work);
631 num [num_hi_sig] += carry;
634 /* store the quotient digit. */
639 decode (quo, lquo, hquo);
642 /* if result is negative, make it so. */
644 neg_double (*lquo, *hquo, lquo, hquo);
646 /* compute trial remainder: rem = num - (quo * den) */
647 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
648 neg_double (*lrem, *hrem, lrem, hrem);
649 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
654 case TRUNC_MOD_EXPR: /* round toward zero */
655 case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
659 case FLOOR_MOD_EXPR: /* round toward negative infinity */
660 if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
663 add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
666 else return overflow;
670 case CEIL_MOD_EXPR: /* round toward positive infinity */
671 if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
673 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
676 else return overflow;
680 case ROUND_MOD_EXPR: /* round to closest integer */
682 HOST_WIDE_INT labs_rem = *lrem, habs_rem = *hrem;
683 HOST_WIDE_INT labs_den = lden, habs_den = hden, ltwice, htwice;
685 /* get absolute values */
686 if (*hrem < 0) neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
687 if (hden < 0) neg_double (lden, hden, &labs_den, &habs_den);
689 /* if (2 * abs (lrem) >= abs (lden)) */
690 mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
691 labs_rem, habs_rem, <wice, &htwice);
692 if (((unsigned HOST_WIDE_INT) habs_den
693 < (unsigned HOST_WIDE_INT) htwice)
694 || (((unsigned HOST_WIDE_INT) habs_den
695 == (unsigned HOST_WIDE_INT) htwice)
696 && ((HOST_WIDE_INT unsigned) labs_den
697 < (unsigned HOST_WIDE_INT) ltwice)))
701 add_double (*lquo, *hquo,
702 (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
705 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
708 else return overflow;
716 /* compute true remainder: rem = num - (quo * den) */
717 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
718 neg_double (*lrem, *hrem, lrem, hrem);
719 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
723 #ifndef REAL_ARITHMETIC
724 /* Effectively truncate a real value to represent the nearest possible value
725 in a narrower mode. The result is actually represented in the same data
726 type as the argument, but its value is usually different.
728 A trap may occur during the FP operations and it is the responsibility
729 of the calling function to have a handler established. */
732 real_value_truncate (mode, arg)
733 enum machine_mode mode;
736 return REAL_VALUE_TRUNCATE (mode, arg);
739 #if TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
741 /* Check for infinity in an IEEE double precision number. */
747 /* The IEEE 64-bit double format. */
752 unsigned exponent : 11;
753 unsigned mantissa1 : 20;
758 unsigned mantissa1 : 20;
759 unsigned exponent : 11;
765 if (u.big_endian.sign == 1)
768 return (u.big_endian.exponent == 2047
769 && u.big_endian.mantissa1 == 0
770 && u.big_endian.mantissa2 == 0);
775 return (u.little_endian.exponent == 2047
776 && u.little_endian.mantissa1 == 0
777 && u.little_endian.mantissa2 == 0);
781 /* Check whether an IEEE double precision number is a NaN. */
787 /* The IEEE 64-bit double format. */
792 unsigned exponent : 11;
793 unsigned mantissa1 : 20;
798 unsigned mantissa1 : 20;
799 unsigned exponent : 11;
805 if (u.big_endian.sign == 1)
808 return (u.big_endian.exponent == 2047
809 && (u.big_endian.mantissa1 != 0
810 || u.big_endian.mantissa2 != 0));
815 return (u.little_endian.exponent == 2047
816 && (u.little_endian.mantissa1 != 0
817 || u.little_endian.mantissa2 != 0));
821 /* Check for a negative IEEE double precision number. */
827 /* The IEEE 64-bit double format. */
832 unsigned exponent : 11;
833 unsigned mantissa1 : 20;
838 unsigned mantissa1 : 20;
839 unsigned exponent : 11;
845 if (u.big_endian.sign == 1)
848 return u.big_endian.sign;
853 return u.little_endian.sign;
856 #else /* Target not IEEE */
858 /* Let's assume other float formats don't have infinity.
859 (This can be overridden by redefining REAL_VALUE_ISINF.) */
868 /* Let's assume other float formats don't have NaNs.
869 (This can be overridden by redefining REAL_VALUE_ISNAN.) */
878 /* Let's assume other float formats don't have minus zero.
879 (This can be overridden by redefining REAL_VALUE_NEGATIVE.) */
887 #endif /* Target not IEEE */
889 /* Try to change R into its exact multiplicative inverse in machine mode
890 MODE. Return nonzero function value if successful. */
893 exact_real_inverse (mode, r)
894 enum machine_mode mode;
905 /* Usually disable if bounds checks are not reliable. */
906 if ((HOST_FLOAT_FORMAT != TARGET_FLOAT_FORMAT) && !flag_pretend_float)
909 /* Set array index to the less significant bits in the unions, depending
910 on the endian-ness of the host doubles.
911 Disable if insufficient information on the data structure. */
912 #if HOST_FLOAT_FORMAT == UNKNOWN_FLOAT_FORMAT
915 #if HOST_FLOAT_FORMAT == VAX_FLOAT_FORMAT
918 #if HOST_FLOAT_FORMAT == IBM_FLOAT_FORMAT
921 #define K (2 * HOST_FLOAT_WORDS_BIG_ENDIAN)
926 if (setjmp (float_error))
928 /* Don't do the optimization if there was an arithmetic error. */
930 set_float_handler (NULL_PTR);
933 set_float_handler (float_error);
935 /* Domain check the argument. */
941 if (REAL_VALUE_ISINF (x.d) || REAL_VALUE_ISNAN (x.d))
945 /* Compute the reciprocal and check for numerical exactness.
946 It is unnecessary to check all the significand bits to determine
947 whether X is a power of 2. If X is not, then it is impossible for
948 the bottom half significand of both X and 1/X to be all zero bits.
949 Hence we ignore the data structure of the top half and examine only
950 the low order bits of the two significands. */
952 if (x.i[K] != 0 || x.i[K + 1] != 0 || t.i[K] != 0 || t.i[K + 1] != 0)
955 /* Truncate to the required mode and range-check the result. */
956 y.d = REAL_VALUE_TRUNCATE (mode, t.d);
957 #ifdef CHECK_FLOAT_VALUE
959 if (CHECK_FLOAT_VALUE (mode, y.d, i))
963 /* Fail if truncation changed the value. */
964 if (y.d != t.d || y.d == 0.0)
968 if (REAL_VALUE_ISINF (y.d) || REAL_VALUE_ISNAN (y.d))
972 /* Output the reciprocal and return success flag. */
973 set_float_handler (NULL_PTR);
979 /* Convert C9X hexadecimal floating point string constant S. Return
980 real value type in mode MODE. This function uses the host computer's
981 fp arithmetic when there is no REAL_ARITHMETIC. */
984 real_hex_to_f (s, mode)
986 enum machine_mode mode;
990 unsigned HOST_WIDE_INT low, high;
991 int frexpon, expon, shcount, nrmcount, k;
992 int sign, expsign, decpt, isfloat, isldouble, gotp, lost;
1002 while (*p == ' ' || *p == '\t')
1005 /* Sign, if any, comes first. */
1013 /* The string is supposed to start with 0x or 0X . */
1017 if (*p == 'x' || *p == 'X')
1030 lost = 0; /* Nonzero low order bits shifted out and discarded. */
1031 frexpon = 0; /* Bits after the decimal point. */
1032 expon = 0; /* Value of exponent. */
1033 decpt = 0; /* How many decimal points. */
1034 gotp = 0; /* How many P's. */
1036 while ((c = *p) != '\0')
1038 if ((c >= '0' && c <= '9') || (c >= 'A' && c <= 'F')
1039 || (c >= 'a' && c <= 'f'))
1049 if ((high & 0xf0000000) == 0)
1051 high = (high << 4) + ((low >> 28) & 15);
1052 low = (low << 4) + k;
1059 /* Record nonzero lost bits. */
1071 else if (c == 'p' || c == 'P')
1075 /* Sign of exponent. */
1081 /* Value of exponent.
1082 The exponent field is a decimal integer. */
1085 k = (*p++ & 0x7f) - '0';
1086 expon = 10 * expon + k;
1089 /* F suffix is ambiguous in the significand part
1090 so it must appear after the decimal exponent field. */
1091 if (*p == 'f' || *p == 'F')
1098 else if (c == 'l' || c == 'L')
1107 /* Abort if last character read was not legitimate. */
1109 if ((c != '\0' && c != ' ' && c != '\n' && c != '\r') || (decpt > 1))
1111 /* There must be either one decimal point or one p. */
1112 if (decpt == 0 && gotp == 0)
1115 if ((high == 0) && (low == 0))
1128 /* Leave a high guard bit for carry-out. */
1129 if ((high & 0x80000000) != 0)
1132 low = (low >> 1) | (high << 31);
1136 if ((high & 0xffff8000) == 0)
1138 high = (high << 16) + ((low >> 16) & 0xffff);
1142 while ((high & 0xc0000000) == 0)
1144 high = (high << 1) + ((low >> 31) & 1);
1148 if (isfloat || GET_MODE_SIZE(mode) == UNITS_PER_WORD)
1150 /* Keep 24 bits precision, bits 0x7fffff80.
1151 Rounding bit is 0x40. */
1152 lost = lost | low | (high & 0x3f);
1156 if ((high & 0x80) || lost)
1163 /* We need real.c to do long double formats, so here default
1164 to double precision. */
1165 #if HOST_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
1167 Keep 53 bits precision, bits 0x7fffffff fffffc00.
1168 Rounding bit is low word 0x200. */
1169 lost = lost | (low & 0x1ff);
1172 if ((low & 0x400) || lost)
1174 low = (low + 0x200) & 0xfffffc00;
1181 /* Assume it's a VAX with 56-bit significand,
1182 bits 0x7fffffff ffffff80. */
1183 lost = lost | (low & 0x7f);
1186 if ((low & 0x80) || lost)
1188 low = (low + 0x40) & 0xffffff80;
1197 ip = REAL_VALUE_LDEXP (ip, 32) + (double) low;
1198 /* Apply shifts and exponent value as power of 2. */
1199 ip = REAL_VALUE_LDEXP (ip, expon - (nrmcount + frexpon));
1206 #endif /* no REAL_ARITHMETIC */
1208 /* Given T, an expression, return the negation of T. Allow for T to be
1209 null, in which case return null. */
1221 type = TREE_TYPE (t);
1222 STRIP_SIGN_NOPS (t);
1224 switch (TREE_CODE (t))
1228 if (! TREE_UNSIGNED (type)
1229 && 0 != (tem = fold (build1 (NEGATE_EXPR, type, t)))
1230 && ! TREE_OVERFLOW (tem))
1235 return convert (type, TREE_OPERAND (t, 0));
1238 /* - (A - B) -> B - A */
1239 if (! FLOAT_TYPE_P (type) || flag_fast_math)
1240 return convert (type,
1241 fold (build (MINUS_EXPR, TREE_TYPE (t),
1242 TREE_OPERAND (t, 1),
1243 TREE_OPERAND (t, 0))));
1250 return convert (type, build1 (NEGATE_EXPR, TREE_TYPE (t), t));
1253 /* Split a tree IN into a constant, literal and variable parts that could be
1254 combined with CODE to make IN. "constant" means an expression with
1255 TREE_CONSTANT but that isn't an actual constant. CODE must be a
1256 commutative arithmetic operation. Store the constant part into *CONP,
1257 the literal in &LITP and return the variable part. If a part isn't
1258 present, set it to null. If the tree does not decompose in this way,
1259 return the entire tree as the variable part and the other parts as null.
1261 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
1262 case, we negate an operand that was subtracted. If NEGATE_P is true, we
1263 are negating all of IN.
1265 If IN is itself a literal or constant, return it as appropriate.
1267 Note that we do not guarantee that any of the three values will be the
1268 same type as IN, but they will have the same signedness and mode. */
1271 split_tree (in, code, conp, litp, negate_p)
1273 enum tree_code code;
1282 /* Strip any conversions that don't change the machine mode or signedness. */
1283 STRIP_SIGN_NOPS (in);
1285 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST)
1287 else if (TREE_CONSTANT (in))
1290 else if (TREE_CODE (in) == code
1291 || (! FLOAT_TYPE_P (TREE_TYPE (in))
1292 /* We can associate addition and subtraction together (even
1293 though the C standard doesn't say so) for integers because
1294 the value is not affected. For reals, the value might be
1295 affected, so we can't. */
1296 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
1297 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
1299 tree op0 = TREE_OPERAND (in, 0);
1300 tree op1 = TREE_OPERAND (in, 1);
1301 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
1302 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
1304 /* First see if either of the operands is a literal, then a constant. */
1305 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
1306 *litp = op0, op0 = 0;
1307 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST)
1308 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
1310 if (op0 != 0 && TREE_CONSTANT (op0))
1311 *conp = op0, op0 = 0;
1312 else if (op1 != 0 && TREE_CONSTANT (op1))
1313 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
1315 /* If we haven't dealt with either operand, this is not a case we can
1316 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1317 if (op0 != 0 && op1 != 0)
1322 var = op1, neg_var_p = neg1_p;
1324 /* Now do any needed negations. */
1325 if (neg_litp_p) *litp = negate_expr (*litp);
1326 if (neg_conp_p) *conp = negate_expr (*conp);
1327 if (neg_var_p) var = negate_expr (var);
1334 var = negate_expr (var);
1335 *conp = negate_expr (*conp);
1336 *litp = negate_expr (*litp);
1342 /* Re-associate trees split by the above function. T1 and T2 are either
1343 expressions to associate or null. Return the new expression, if any. If
1344 we build an operation, do it in TYPE and with CODE, except if CODE is a
1345 MINUS_EXPR, in which case we use PLUS_EXPR since split_tree will already
1346 have taken care of the negations. */
1349 associate_trees (t1, t2, code, type)
1351 enum tree_code code;
1359 if (code == MINUS_EXPR)
1362 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1363 try to fold this since we will have infinite recursion. But do
1364 deal with any NEGATE_EXPRs. */
1365 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
1366 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1368 if (TREE_CODE (t1) == NEGATE_EXPR)
1369 return build (MINUS_EXPR, type, convert (type, t2),
1370 convert (type, TREE_OPERAND (t1, 0)));
1371 else if (TREE_CODE (t2) == NEGATE_EXPR)
1372 return build (MINUS_EXPR, type, convert (type, t1),
1373 convert (type, TREE_OPERAND (t2, 0)));
1375 return build (code, type, convert (type, t1), convert (type, t2));
1378 return fold (build (code, type, convert (type, t1), convert (type, t2)));
1381 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1382 to produce a new constant.
1384 If NOTRUNC is nonzero, do not truncate the result to fit the data type.
1385 If FORSIZE is nonzero, compute overflow for unsigned types. */
1388 int_const_binop (code, arg1, arg2, notrunc, forsize)
1389 enum tree_code code;
1390 register tree arg1, arg2;
1391 int notrunc, forsize;
1393 HOST_WIDE_INT int1l, int1h, int2l, int2h;
1394 HOST_WIDE_INT low, hi;
1395 HOST_WIDE_INT garbagel, garbageh;
1397 int uns = TREE_UNSIGNED (TREE_TYPE (arg1));
1399 int no_overflow = 0;
1401 int1l = TREE_INT_CST_LOW (arg1);
1402 int1h = TREE_INT_CST_HIGH (arg1);
1403 int2l = TREE_INT_CST_LOW (arg2);
1404 int2h = TREE_INT_CST_HIGH (arg2);
1409 low = int1l | int2l, hi = int1h | int2h;
1413 low = int1l ^ int2l, hi = int1h ^ int2h;
1417 low = int1l & int2l, hi = int1h & int2h;
1420 case BIT_ANDTC_EXPR:
1421 low = int1l & ~int2l, hi = int1h & ~int2h;
1427 /* It's unclear from the C standard whether shifts can overflow.
1428 The following code ignores overflow; perhaps a C standard
1429 interpretation ruling is needed. */
1430 lshift_double (int1l, int1h, int2l,
1431 TYPE_PRECISION (TREE_TYPE (arg1)),
1440 lrotate_double (int1l, int1h, int2l,
1441 TYPE_PRECISION (TREE_TYPE (arg1)),
1446 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1450 neg_double (int2l, int2h, &low, &hi);
1451 add_double (int1l, int1h, low, hi, &low, &hi);
1452 overflow = overflow_sum_sign (hi, int2h, int1h);
1456 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1459 case TRUNC_DIV_EXPR:
1460 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1461 case EXACT_DIV_EXPR:
1462 /* This is a shortcut for a common special case. */
1463 if (int2h == 0 && int2l > 0
1464 && ! TREE_CONSTANT_OVERFLOW (arg1)
1465 && ! TREE_CONSTANT_OVERFLOW (arg2)
1466 && int1h == 0 && int1l >= 0)
1468 if (code == CEIL_DIV_EXPR)
1470 low = int1l / int2l, hi = 0;
1474 /* ... fall through ... */
1476 case ROUND_DIV_EXPR:
1477 if (int2h == 0 && int2l == 1)
1479 low = int1l, hi = int1h;
1482 if (int1l == int2l && int1h == int2h
1483 && ! (int1l == 0 && int1h == 0))
1488 overflow = div_and_round_double (code, uns,
1489 int1l, int1h, int2l, int2h,
1490 &low, &hi, &garbagel, &garbageh);
1493 case TRUNC_MOD_EXPR:
1494 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1495 /* This is a shortcut for a common special case. */
1496 if (int2h == 0 && int2l > 0
1497 && ! TREE_CONSTANT_OVERFLOW (arg1)
1498 && ! TREE_CONSTANT_OVERFLOW (arg2)
1499 && int1h == 0 && int1l >= 0)
1501 if (code == CEIL_MOD_EXPR)
1503 low = int1l % int2l, hi = 0;
1507 /* ... fall through ... */
1509 case ROUND_MOD_EXPR:
1510 overflow = div_and_round_double (code, uns,
1511 int1l, int1h, int2l, int2h,
1512 &garbagel, &garbageh, &low, &hi);
1519 low = (((unsigned HOST_WIDE_INT) int1h
1520 < (unsigned HOST_WIDE_INT) int2h)
1521 || (((unsigned HOST_WIDE_INT) int1h
1522 == (unsigned HOST_WIDE_INT) int2h)
1523 && ((unsigned HOST_WIDE_INT) int1l
1524 < (unsigned HOST_WIDE_INT) int2l)));
1528 low = ((int1h < int2h)
1529 || ((int1h == int2h)
1530 && ((unsigned HOST_WIDE_INT) int1l
1531 < (unsigned HOST_WIDE_INT) int2l)));
1533 if (low == (code == MIN_EXPR))
1534 low = int1l, hi = int1h;
1536 low = int2l, hi = int2h;
1543 if (TREE_TYPE (arg1) == sizetype && hi == 0
1545 && (TYPE_MAX_VALUE (sizetype) == NULL
1546 || low <= TREE_INT_CST_LOW (TYPE_MAX_VALUE (sizetype)))
1548 && ! TREE_OVERFLOW (arg1) && ! TREE_OVERFLOW (arg2))
1552 t = build_int_2 (low, hi);
1553 TREE_TYPE (t) = TREE_TYPE (arg1);
1557 = ((notrunc ? (!uns || forsize) && overflow
1558 : force_fit_type (t, (!uns || forsize) && overflow) && ! no_overflow)
1559 | TREE_OVERFLOW (arg1)
1560 | TREE_OVERFLOW (arg2));
1561 /* If we're doing a size calculation, unsigned arithmetic does overflow.
1562 So check if force_fit_type truncated the value. */
1564 && ! TREE_OVERFLOW (t)
1565 && (TREE_INT_CST_HIGH (t) != hi
1566 || TREE_INT_CST_LOW (t) != low))
1567 TREE_OVERFLOW (t) = 1;
1568 TREE_CONSTANT_OVERFLOW (t) = (TREE_OVERFLOW (t)
1569 | TREE_CONSTANT_OVERFLOW (arg1)
1570 | TREE_CONSTANT_OVERFLOW (arg2));
1578 REAL_VALUE_TYPE d1, d2;
1579 enum tree_code code;
1585 const_binop_1 (data)
1588 struct cb_args * args = (struct cb_args *) data;
1589 REAL_VALUE_TYPE value;
1591 #ifdef REAL_ARITHMETIC
1592 REAL_ARITHMETIC (value, args->code, args->d1, args->d2);
1597 value = args->d1 + args->d2;
1601 value = args->d1 - args->d2;
1605 value = args->d1 * args->d2;
1609 #ifndef REAL_INFINITY
1614 value = args->d1 / args->d2;
1618 value = MIN (args->d1, args->d2);
1622 value = MAX (args->d1, args->d2);
1628 #endif /* no REAL_ARITHMETIC */
1630 build_real (TREE_TYPE (args->arg1),
1631 real_value_truncate (TYPE_MODE (TREE_TYPE (args->arg1)),
1635 /* Combine two constants ARG1 and ARG2 under operation CODE
1636 to produce a new constant.
1637 We assume ARG1 and ARG2 have the same data type,
1638 or at least are the same kind of constant and the same machine mode.
1640 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1643 const_binop (code, arg1, arg2, notrunc)
1644 enum tree_code code;
1645 register tree arg1, arg2;
1648 STRIP_NOPS (arg1); STRIP_NOPS (arg2);
1650 if (TREE_CODE (arg1) == INTEGER_CST)
1651 return int_const_binop (code, arg1, arg2, notrunc, 0);
1653 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1654 if (TREE_CODE (arg1) == REAL_CST)
1660 struct cb_args args;
1662 d1 = TREE_REAL_CST (arg1);
1663 d2 = TREE_REAL_CST (arg2);
1665 /* If either operand is a NaN, just return it. Otherwise, set up
1666 for floating-point trap; we return an overflow. */
1667 if (REAL_VALUE_ISNAN (d1))
1669 else if (REAL_VALUE_ISNAN (d2))
1672 /* Setup input for const_binop_1() */
1678 if (do_float_handler (const_binop_1, (PTR) &args))
1680 /* Receive output from const_binop_1() */
1685 /* We got an exception from const_binop_1() */
1686 t = copy_node (arg1);
1691 = (force_fit_type (t, overflow)
1692 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
1693 TREE_CONSTANT_OVERFLOW (t)
1695 | TREE_CONSTANT_OVERFLOW (arg1)
1696 | TREE_CONSTANT_OVERFLOW (arg2);
1699 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
1700 if (TREE_CODE (arg1) == COMPLEX_CST)
1702 register tree type = TREE_TYPE (arg1);
1703 register tree r1 = TREE_REALPART (arg1);
1704 register tree i1 = TREE_IMAGPART (arg1);
1705 register tree r2 = TREE_REALPART (arg2);
1706 register tree i2 = TREE_IMAGPART (arg2);
1712 t = build_complex (type,
1713 const_binop (PLUS_EXPR, r1, r2, notrunc),
1714 const_binop (PLUS_EXPR, i1, i2, notrunc));
1718 t = build_complex (type,
1719 const_binop (MINUS_EXPR, r1, r2, notrunc),
1720 const_binop (MINUS_EXPR, i1, i2, notrunc));
1724 t = build_complex (type,
1725 const_binop (MINUS_EXPR,
1726 const_binop (MULT_EXPR,
1728 const_binop (MULT_EXPR,
1731 const_binop (PLUS_EXPR,
1732 const_binop (MULT_EXPR,
1734 const_binop (MULT_EXPR,
1741 register tree magsquared
1742 = const_binop (PLUS_EXPR,
1743 const_binop (MULT_EXPR, r2, r2, notrunc),
1744 const_binop (MULT_EXPR, i2, i2, notrunc),
1747 t = build_complex (type,
1749 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1750 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1751 const_binop (PLUS_EXPR,
1752 const_binop (MULT_EXPR, r1, r2,
1754 const_binop (MULT_EXPR, i1, i2,
1757 magsquared, notrunc),
1759 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1760 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1761 const_binop (MINUS_EXPR,
1762 const_binop (MULT_EXPR, i1, r2,
1764 const_binop (MULT_EXPR, r1, i2,
1767 magsquared, notrunc));
1779 /* Return an INTEGER_CST with value V . The type is determined by bit_p:
1780 if it is zero, the type is taken from sizetype; if it is one, the type
1781 is taken from bitsizetype. */
1784 size_int_wide (number, high, bit_p)
1785 unsigned HOST_WIDE_INT number, high;
1792 /* Type-size nodes already made for small sizes. */
1793 static tree size_table[2*HOST_BITS_PER_WIDE_INT + 1][2];
1795 if (number < 2*HOST_BITS_PER_WIDE_INT + 1 && ! high
1796 && size_table[number][bit_p] != 0)
1797 return size_table[number][bit_p];
1798 if (number < 2*HOST_BITS_PER_WIDE_INT + 1 && ! high)
1800 push_obstacks_nochange ();
1801 /* Make this a permanent node. */
1802 end_temporary_allocation ();
1803 t = build_int_2 (number, 0);
1804 TREE_TYPE (t) = bit_p ? bitsizetype : sizetype;
1805 size_table[number][bit_p] = t;
1811 t = build_int_2 (number, high);
1812 TREE_TYPE (t) = bit_p ? bitsizetype : sizetype;
1813 TREE_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (t) = force_fit_type (t, 0);
1817 /* Combine operands OP1 and OP2 with arithmetic operation CODE.
1818 CODE is a tree code. Data type is taken from `sizetype',
1819 If the operands are constant, so is the result. */
1822 size_binop (code, arg0, arg1)
1823 enum tree_code code;
1826 /* Handle the special case of two integer constants faster. */
1827 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1829 /* And some specific cases even faster than that. */
1830 if (code == PLUS_EXPR && integer_zerop (arg0))
1832 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1833 && integer_zerop (arg1))
1835 else if (code == MULT_EXPR && integer_onep (arg0))
1838 /* Handle general case of two integer constants. */
1839 return int_const_binop (code, arg0, arg1, 0, 1);
1842 if (arg0 == error_mark_node || arg1 == error_mark_node)
1843 return error_mark_node;
1845 return fold (build (code, sizetype, arg0, arg1));
1848 /* Combine operands OP1 and OP2 with arithmetic operation CODE.
1849 CODE is a tree code. Data type is taken from `ssizetype',
1850 If the operands are constant, so is the result. */
1853 ssize_binop (code, arg0, arg1)
1854 enum tree_code code;
1857 /* Handle the special case of two integer constants faster. */
1858 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1860 /* And some specific cases even faster than that. */
1861 if (code == PLUS_EXPR && integer_zerop (arg0))
1863 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1864 && integer_zerop (arg1))
1866 else if (code == MULT_EXPR && integer_onep (arg0))
1869 /* Handle general case of two integer constants. We convert
1870 arg0 to ssizetype because int_const_binop uses its type for the
1872 arg0 = convert (ssizetype, arg0);
1873 return int_const_binop (code, arg0, arg1, 0, 0);
1876 if (arg0 == error_mark_node || arg1 == error_mark_node)
1877 return error_mark_node;
1879 return fold (build (code, ssizetype, arg0, arg1));
1891 fold_convert_1 (data)
1894 struct fc_args * args = (struct fc_args *) data;
1896 args->t = build_real (args->type,
1897 real_value_truncate (TYPE_MODE (args->type),
1898 TREE_REAL_CST (args->arg1)));
1901 /* Given T, a tree representing type conversion of ARG1, a constant,
1902 return a constant tree representing the result of conversion. */
1905 fold_convert (t, arg1)
1909 register tree type = TREE_TYPE (t);
1912 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
1914 if (TREE_CODE (arg1) == INTEGER_CST)
1916 /* If we would build a constant wider than GCC supports,
1917 leave the conversion unfolded. */
1918 if (TYPE_PRECISION (type) > 2 * HOST_BITS_PER_WIDE_INT)
1921 /* Given an integer constant, make new constant with new type,
1922 appropriately sign-extended or truncated. */
1923 t = build_int_2 (TREE_INT_CST_LOW (arg1),
1924 TREE_INT_CST_HIGH (arg1));
1925 TREE_TYPE (t) = type;
1926 /* Indicate an overflow if (1) ARG1 already overflowed,
1927 or (2) force_fit_type indicates an overflow.
1928 Tell force_fit_type that an overflow has already occurred
1929 if ARG1 is a too-large unsigned value and T is signed.
1930 But don't indicate an overflow if converting a pointer. */
1932 = ((force_fit_type (t,
1933 (TREE_INT_CST_HIGH (arg1) < 0
1934 && (TREE_UNSIGNED (type)
1935 < TREE_UNSIGNED (TREE_TYPE (arg1)))))
1936 && ! POINTER_TYPE_P (TREE_TYPE (arg1)))
1937 || TREE_OVERFLOW (arg1));
1938 TREE_CONSTANT_OVERFLOW (t)
1939 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1941 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1942 else if (TREE_CODE (arg1) == REAL_CST)
1944 /* Don't initialize these, use assignments.
1945 Initialized local aggregates don't work on old compilers. */
1949 tree type1 = TREE_TYPE (arg1);
1952 x = TREE_REAL_CST (arg1);
1953 l = real_value_from_int_cst (type1, TYPE_MIN_VALUE (type));
1955 no_upper_bound = (TYPE_MAX_VALUE (type) == NULL);
1956 if (!no_upper_bound)
1957 u = real_value_from_int_cst (type1, TYPE_MAX_VALUE (type));
1959 /* See if X will be in range after truncation towards 0.
1960 To compensate for truncation, move the bounds away from 0,
1961 but reject if X exactly equals the adjusted bounds. */
1962 #ifdef REAL_ARITHMETIC
1963 REAL_ARITHMETIC (l, MINUS_EXPR, l, dconst1);
1964 if (!no_upper_bound)
1965 REAL_ARITHMETIC (u, PLUS_EXPR, u, dconst1);
1968 if (!no_upper_bound)
1971 /* If X is a NaN, use zero instead and show we have an overflow.
1972 Otherwise, range check. */
1973 if (REAL_VALUE_ISNAN (x))
1974 overflow = 1, x = dconst0;
1975 else if (! (REAL_VALUES_LESS (l, x)
1977 && REAL_VALUES_LESS (x, u)))
1980 #ifndef REAL_ARITHMETIC
1982 HOST_WIDE_INT low, high;
1983 HOST_WIDE_INT half_word
1984 = (HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2);
1989 high = (HOST_WIDE_INT) (x / half_word / half_word);
1990 x -= (REAL_VALUE_TYPE) high * half_word * half_word;
1991 if (x >= (REAL_VALUE_TYPE) half_word * half_word / 2)
1993 low = x - (REAL_VALUE_TYPE) half_word * half_word / 2;
1994 low |= (HOST_WIDE_INT) -1 << (HOST_BITS_PER_WIDE_INT - 1);
1997 low = (HOST_WIDE_INT) x;
1998 if (TREE_REAL_CST (arg1) < 0)
1999 neg_double (low, high, &low, &high);
2000 t = build_int_2 (low, high);
2004 HOST_WIDE_INT low, high;
2005 REAL_VALUE_TO_INT (&low, &high, x);
2006 t = build_int_2 (low, high);
2009 TREE_TYPE (t) = type;
2011 = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
2012 TREE_CONSTANT_OVERFLOW (t)
2013 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
2015 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
2016 TREE_TYPE (t) = type;
2018 else if (TREE_CODE (type) == REAL_TYPE)
2020 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
2021 if (TREE_CODE (arg1) == INTEGER_CST)
2022 return build_real_from_int_cst (type, arg1);
2023 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
2024 if (TREE_CODE (arg1) == REAL_CST)
2026 struct fc_args args;
2028 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
2031 TREE_TYPE (arg1) = type;
2035 /* Setup input for fold_convert_1() */
2039 if (do_float_handler (fold_convert_1, (PTR) &args))
2041 /* Receive output from fold_convert_1() */
2046 /* We got an exception from fold_convert_1() */
2048 t = copy_node (arg1);
2052 = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
2053 TREE_CONSTANT_OVERFLOW (t)
2054 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
2058 TREE_CONSTANT (t) = 1;
2062 /* Return an expr equal to X but certainly not valid as an lvalue. */
2070 /* These things are certainly not lvalues. */
2071 if (TREE_CODE (x) == NON_LVALUE_EXPR
2072 || TREE_CODE (x) == INTEGER_CST
2073 || TREE_CODE (x) == REAL_CST
2074 || TREE_CODE (x) == STRING_CST
2075 || TREE_CODE (x) == ADDR_EXPR)
2078 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
2079 TREE_CONSTANT (result) = TREE_CONSTANT (x);
2083 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
2084 Zero means allow extended lvalues. */
2086 int pedantic_lvalues;
2088 /* When pedantic, return an expr equal to X but certainly not valid as a
2089 pedantic lvalue. Otherwise, return X. */
2092 pedantic_non_lvalue (x)
2095 if (pedantic_lvalues)
2096 return non_lvalue (x);
2101 /* Given a tree comparison code, return the code that is the logical inverse
2102 of the given code. It is not safe to do this for floating-point
2103 comparisons, except for NE_EXPR and EQ_EXPR. */
2105 static enum tree_code
2106 invert_tree_comparison (code)
2107 enum tree_code code;
2128 /* Similar, but return the comparison that results if the operands are
2129 swapped. This is safe for floating-point. */
2131 static enum tree_code
2132 swap_tree_comparison (code)
2133 enum tree_code code;
2153 /* Return nonzero if CODE is a tree code that represents a truth value. */
2156 truth_value_p (code)
2157 enum tree_code code;
2159 return (TREE_CODE_CLASS (code) == '<'
2160 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2161 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2162 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
2165 /* Return nonzero if two operands are necessarily equal.
2166 If ONLY_CONST is non-zero, only return non-zero for constants.
2167 This function tests whether the operands are indistinguishable;
2168 it does not test whether they are equal using C's == operation.
2169 The distinction is important for IEEE floating point, because
2170 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2171 (2) two NaNs may be indistinguishable, but NaN!=NaN. */
2174 operand_equal_p (arg0, arg1, only_const)
2178 /* If both types don't have the same signedness, then we can't consider
2179 them equal. We must check this before the STRIP_NOPS calls
2180 because they may change the signedness of the arguments. */
2181 if (TREE_UNSIGNED (TREE_TYPE (arg0)) != TREE_UNSIGNED (TREE_TYPE (arg1)))
2187 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2188 /* This is needed for conversions and for COMPONENT_REF.
2189 Might as well play it safe and always test this. */
2190 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
2191 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
2192 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
2195 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
2196 We don't care about side effects in that case because the SAVE_EXPR
2197 takes care of that for us. In all other cases, two expressions are
2198 equal if they have no side effects. If we have two identical
2199 expressions with side effects that should be treated the same due
2200 to the only side effects being identical SAVE_EXPR's, that will
2201 be detected in the recursive calls below. */
2202 if (arg0 == arg1 && ! only_const
2203 && (TREE_CODE (arg0) == SAVE_EXPR
2204 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
2207 /* Next handle constant cases, those for which we can return 1 even
2208 if ONLY_CONST is set. */
2209 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
2210 switch (TREE_CODE (arg0))
2213 return (! TREE_CONSTANT_OVERFLOW (arg0)
2214 && ! TREE_CONSTANT_OVERFLOW (arg1)
2215 && TREE_INT_CST_LOW (arg0) == TREE_INT_CST_LOW (arg1)
2216 && TREE_INT_CST_HIGH (arg0) == TREE_INT_CST_HIGH (arg1));
2219 return (! TREE_CONSTANT_OVERFLOW (arg0)
2220 && ! TREE_CONSTANT_OVERFLOW (arg1)
2221 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
2222 TREE_REAL_CST (arg1)));
2225 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
2227 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
2231 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
2232 && ! strncmp (TREE_STRING_POINTER (arg0),
2233 TREE_STRING_POINTER (arg1),
2234 TREE_STRING_LENGTH (arg0)));
2237 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
2246 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
2249 /* Two conversions are equal only if signedness and modes match. */
2250 if ((TREE_CODE (arg0) == NOP_EXPR || TREE_CODE (arg0) == CONVERT_EXPR)
2251 && (TREE_UNSIGNED (TREE_TYPE (arg0))
2252 != TREE_UNSIGNED (TREE_TYPE (arg1))))
2255 return operand_equal_p (TREE_OPERAND (arg0, 0),
2256 TREE_OPERAND (arg1, 0), 0);
2260 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0)
2261 && operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1),
2265 /* For commutative ops, allow the other order. */
2266 return ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MULT_EXPR
2267 || TREE_CODE (arg0) == MIN_EXPR || TREE_CODE (arg0) == MAX_EXPR
2268 || TREE_CODE (arg0) == BIT_IOR_EXPR
2269 || TREE_CODE (arg0) == BIT_XOR_EXPR
2270 || TREE_CODE (arg0) == BIT_AND_EXPR
2271 || TREE_CODE (arg0) == NE_EXPR || TREE_CODE (arg0) == EQ_EXPR)
2272 && operand_equal_p (TREE_OPERAND (arg0, 0),
2273 TREE_OPERAND (arg1, 1), 0)
2274 && operand_equal_p (TREE_OPERAND (arg0, 1),
2275 TREE_OPERAND (arg1, 0), 0));
2278 /* If either of the pointer (or reference) expressions we are dereferencing
2279 contain a side effect, these cannot be equal. */
2280 if (TREE_SIDE_EFFECTS (arg0)
2281 || TREE_SIDE_EFFECTS (arg1))
2284 switch (TREE_CODE (arg0))
2287 return operand_equal_p (TREE_OPERAND (arg0, 0),
2288 TREE_OPERAND (arg1, 0), 0);
2292 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2293 TREE_OPERAND (arg1, 0), 0)
2294 && operand_equal_p (TREE_OPERAND (arg0, 1),
2295 TREE_OPERAND (arg1, 1), 0));
2298 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2299 TREE_OPERAND (arg1, 0), 0)
2300 && operand_equal_p (TREE_OPERAND (arg0, 1),
2301 TREE_OPERAND (arg1, 1), 0)
2302 && operand_equal_p (TREE_OPERAND (arg0, 2),
2303 TREE_OPERAND (arg1, 2), 0));
2309 if (TREE_CODE (arg0) == RTL_EXPR)
2310 return rtx_equal_p (RTL_EXPR_RTL (arg0), RTL_EXPR_RTL (arg1));
2318 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2319 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2321 When in doubt, return 0. */
2324 operand_equal_for_comparison_p (arg0, arg1, other)
2328 int unsignedp1, unsignedpo;
2329 tree primarg0, primarg1, primother;
2330 unsigned correct_width;
2332 if (operand_equal_p (arg0, arg1, 0))
2335 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
2336 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
2339 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2340 and see if the inner values are the same. This removes any
2341 signedness comparison, which doesn't matter here. */
2342 primarg0 = arg0, primarg1 = arg1;
2343 STRIP_NOPS (primarg0); STRIP_NOPS (primarg1);
2344 if (operand_equal_p (primarg0, primarg1, 0))
2347 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2348 actual comparison operand, ARG0.
2350 First throw away any conversions to wider types
2351 already present in the operands. */
2353 primarg1 = get_narrower (arg1, &unsignedp1);
2354 primother = get_narrower (other, &unsignedpo);
2356 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
2357 if (unsignedp1 == unsignedpo
2358 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
2359 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
2361 tree type = TREE_TYPE (arg0);
2363 /* Make sure shorter operand is extended the right way
2364 to match the longer operand. */
2365 primarg1 = convert (signed_or_unsigned_type (unsignedp1,
2366 TREE_TYPE (primarg1)),
2369 if (operand_equal_p (arg0, convert (type, primarg1), 0))
2376 /* See if ARG is an expression that is either a comparison or is performing
2377 arithmetic on comparisons. The comparisons must only be comparing
2378 two different values, which will be stored in *CVAL1 and *CVAL2; if
2379 they are non-zero it means that some operands have already been found.
2380 No variables may be used anywhere else in the expression except in the
2381 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2382 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2384 If this is true, return 1. Otherwise, return zero. */
2387 twoval_comparison_p (arg, cval1, cval2, save_p)
2389 tree *cval1, *cval2;
2392 enum tree_code code = TREE_CODE (arg);
2393 char class = TREE_CODE_CLASS (code);
2395 /* We can handle some of the 'e' cases here. */
2396 if (class == 'e' && code == TRUTH_NOT_EXPR)
2398 else if (class == 'e'
2399 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
2400 || code == COMPOUND_EXPR))
2403 /* ??? Disable this since the SAVE_EXPR might already be in use outside
2404 the expression. There may be no way to make this work, but it needs
2405 to be looked at again for 2.6. */
2407 else if (class == 'e' && code == SAVE_EXPR && SAVE_EXPR_RTL (arg) == 0)
2409 /* If we've already found a CVAL1 or CVAL2, this expression is
2410 two complex to handle. */
2411 if (*cval1 || *cval2)
2422 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
2425 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
2426 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2427 cval1, cval2, save_p));
2433 if (code == COND_EXPR)
2434 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
2435 cval1, cval2, save_p)
2436 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2437 cval1, cval2, save_p)
2438 && twoval_comparison_p (TREE_OPERAND (arg, 2),
2439 cval1, cval2, save_p));
2443 /* First see if we can handle the first operand, then the second. For
2444 the second operand, we know *CVAL1 can't be zero. It must be that
2445 one side of the comparison is each of the values; test for the
2446 case where this isn't true by failing if the two operands
2449 if (operand_equal_p (TREE_OPERAND (arg, 0),
2450 TREE_OPERAND (arg, 1), 0))
2454 *cval1 = TREE_OPERAND (arg, 0);
2455 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
2457 else if (*cval2 == 0)
2458 *cval2 = TREE_OPERAND (arg, 0);
2459 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
2464 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
2466 else if (*cval2 == 0)
2467 *cval2 = TREE_OPERAND (arg, 1);
2468 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
2480 /* ARG is a tree that is known to contain just arithmetic operations and
2481 comparisons. Evaluate the operations in the tree substituting NEW0 for
2482 any occurrence of OLD0 as an operand of a comparison and likewise for
2486 eval_subst (arg, old0, new0, old1, new1)
2488 tree old0, new0, old1, new1;
2490 tree type = TREE_TYPE (arg);
2491 enum tree_code code = TREE_CODE (arg);
2492 char class = TREE_CODE_CLASS (code);
2494 /* We can handle some of the 'e' cases here. */
2495 if (class == 'e' && code == TRUTH_NOT_EXPR)
2497 else if (class == 'e'
2498 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2504 return fold (build1 (code, type,
2505 eval_subst (TREE_OPERAND (arg, 0),
2506 old0, new0, old1, new1)));
2509 return fold (build (code, type,
2510 eval_subst (TREE_OPERAND (arg, 0),
2511 old0, new0, old1, new1),
2512 eval_subst (TREE_OPERAND (arg, 1),
2513 old0, new0, old1, new1)));
2519 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
2522 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
2525 return fold (build (code, type,
2526 eval_subst (TREE_OPERAND (arg, 0),
2527 old0, new0, old1, new1),
2528 eval_subst (TREE_OPERAND (arg, 1),
2529 old0, new0, old1, new1),
2530 eval_subst (TREE_OPERAND (arg, 2),
2531 old0, new0, old1, new1)));
2535 /* fall through - ??? */
2539 tree arg0 = TREE_OPERAND (arg, 0);
2540 tree arg1 = TREE_OPERAND (arg, 1);
2542 /* We need to check both for exact equality and tree equality. The
2543 former will be true if the operand has a side-effect. In that
2544 case, we know the operand occurred exactly once. */
2546 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
2548 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
2551 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
2553 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
2556 return fold (build (code, type, arg0, arg1));
2564 /* Return a tree for the case when the result of an expression is RESULT
2565 converted to TYPE and OMITTED was previously an operand of the expression
2566 but is now not needed (e.g., we folded OMITTED * 0).
2568 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2569 the conversion of RESULT to TYPE. */
2572 omit_one_operand (type, result, omitted)
2573 tree type, result, omitted;
2575 tree t = convert (type, result);
2577 if (TREE_SIDE_EFFECTS (omitted))
2578 return build (COMPOUND_EXPR, type, omitted, t);
2580 return non_lvalue (t);
2583 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2586 pedantic_omit_one_operand (type, result, omitted)
2587 tree type, result, omitted;
2589 tree t = convert (type, result);
2591 if (TREE_SIDE_EFFECTS (omitted))
2592 return build (COMPOUND_EXPR, type, omitted, t);
2594 return pedantic_non_lvalue (t);
2599 /* Return a simplified tree node for the truth-negation of ARG. This
2600 never alters ARG itself. We assume that ARG is an operation that
2601 returns a truth value (0 or 1). */
2604 invert_truthvalue (arg)
2607 tree type = TREE_TYPE (arg);
2608 enum tree_code code = TREE_CODE (arg);
2610 if (code == ERROR_MARK)
2613 /* If this is a comparison, we can simply invert it, except for
2614 floating-point non-equality comparisons, in which case we just
2615 enclose a TRUTH_NOT_EXPR around what we have. */
2617 if (TREE_CODE_CLASS (code) == '<')
2619 if (FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg, 0)))
2620 && !flag_fast_math && code != NE_EXPR && code != EQ_EXPR)
2621 return build1 (TRUTH_NOT_EXPR, type, arg);
2623 return build (invert_tree_comparison (code), type,
2624 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
2630 return convert (type, build_int_2 (TREE_INT_CST_LOW (arg) == 0
2631 && TREE_INT_CST_HIGH (arg) == 0, 0));
2633 case TRUTH_AND_EXPR:
2634 return build (TRUTH_OR_EXPR, type,
2635 invert_truthvalue (TREE_OPERAND (arg, 0)),
2636 invert_truthvalue (TREE_OPERAND (arg, 1)));
2639 return build (TRUTH_AND_EXPR, type,
2640 invert_truthvalue (TREE_OPERAND (arg, 0)),
2641 invert_truthvalue (TREE_OPERAND (arg, 1)));
2643 case TRUTH_XOR_EXPR:
2644 /* Here we can invert either operand. We invert the first operand
2645 unless the second operand is a TRUTH_NOT_EXPR in which case our
2646 result is the XOR of the first operand with the inside of the
2647 negation of the second operand. */
2649 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
2650 return build (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
2651 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
2653 return build (TRUTH_XOR_EXPR, type,
2654 invert_truthvalue (TREE_OPERAND (arg, 0)),
2655 TREE_OPERAND (arg, 1));
2657 case TRUTH_ANDIF_EXPR:
2658 return build (TRUTH_ORIF_EXPR, type,
2659 invert_truthvalue (TREE_OPERAND (arg, 0)),
2660 invert_truthvalue (TREE_OPERAND (arg, 1)));
2662 case TRUTH_ORIF_EXPR:
2663 return build (TRUTH_ANDIF_EXPR, type,
2664 invert_truthvalue (TREE_OPERAND (arg, 0)),
2665 invert_truthvalue (TREE_OPERAND (arg, 1)));
2667 case TRUTH_NOT_EXPR:
2668 return TREE_OPERAND (arg, 0);
2671 return build (COND_EXPR, type, TREE_OPERAND (arg, 0),
2672 invert_truthvalue (TREE_OPERAND (arg, 1)),
2673 invert_truthvalue (TREE_OPERAND (arg, 2)));
2676 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
2677 invert_truthvalue (TREE_OPERAND (arg, 1)));
2679 case WITH_RECORD_EXPR:
2680 return build (WITH_RECORD_EXPR, type,
2681 invert_truthvalue (TREE_OPERAND (arg, 0)),
2682 TREE_OPERAND (arg, 1));
2684 case NON_LVALUE_EXPR:
2685 return invert_truthvalue (TREE_OPERAND (arg, 0));
2690 return build1 (TREE_CODE (arg), type,
2691 invert_truthvalue (TREE_OPERAND (arg, 0)));
2694 if (!integer_onep (TREE_OPERAND (arg, 1)))
2696 return build (EQ_EXPR, type, arg, convert (type, integer_zero_node));
2699 return build1 (TRUTH_NOT_EXPR, type, arg);
2701 case CLEANUP_POINT_EXPR:
2702 return build1 (CLEANUP_POINT_EXPR, type,
2703 invert_truthvalue (TREE_OPERAND (arg, 0)));
2708 if (TREE_CODE (TREE_TYPE (arg)) != BOOLEAN_TYPE)
2710 return build1 (TRUTH_NOT_EXPR, type, arg);
2713 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
2714 operands are another bit-wise operation with a common input. If so,
2715 distribute the bit operations to save an operation and possibly two if
2716 constants are involved. For example, convert
2717 (A | B) & (A | C) into A | (B & C)
2718 Further simplification will occur if B and C are constants.
2720 If this optimization cannot be done, 0 will be returned. */
2723 distribute_bit_expr (code, type, arg0, arg1)
2724 enum tree_code code;
2731 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2732 || TREE_CODE (arg0) == code
2733 || (TREE_CODE (arg0) != BIT_AND_EXPR
2734 && TREE_CODE (arg0) != BIT_IOR_EXPR))
2737 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
2739 common = TREE_OPERAND (arg0, 0);
2740 left = TREE_OPERAND (arg0, 1);
2741 right = TREE_OPERAND (arg1, 1);
2743 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
2745 common = TREE_OPERAND (arg0, 0);
2746 left = TREE_OPERAND (arg0, 1);
2747 right = TREE_OPERAND (arg1, 0);
2749 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
2751 common = TREE_OPERAND (arg0, 1);
2752 left = TREE_OPERAND (arg0, 0);
2753 right = TREE_OPERAND (arg1, 1);
2755 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
2757 common = TREE_OPERAND (arg0, 1);
2758 left = TREE_OPERAND (arg0, 0);
2759 right = TREE_OPERAND (arg1, 0);
2764 return fold (build (TREE_CODE (arg0), type, common,
2765 fold (build (code, type, left, right))));
2768 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
2769 starting at BITPOS. The field is unsigned if UNSIGNEDP is non-zero. */
2772 make_bit_field_ref (inner, type, bitsize, bitpos, unsignedp)
2775 int bitsize, bitpos;
2778 tree result = build (BIT_FIELD_REF, type, inner,
2779 size_int (bitsize), bitsize_int (bitpos, 0L));
2781 TREE_UNSIGNED (result) = unsignedp;
2786 /* Optimize a bit-field compare.
2788 There are two cases: First is a compare against a constant and the
2789 second is a comparison of two items where the fields are at the same
2790 bit position relative to the start of a chunk (byte, halfword, word)
2791 large enough to contain it. In these cases we can avoid the shift
2792 implicit in bitfield extractions.
2794 For constants, we emit a compare of the shifted constant with the
2795 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
2796 compared. For two fields at the same position, we do the ANDs with the
2797 similar mask and compare the result of the ANDs.
2799 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
2800 COMPARE_TYPE is the type of the comparison, and LHS and RHS
2801 are the left and right operands of the comparison, respectively.
2803 If the optimization described above can be done, we return the resulting
2804 tree. Otherwise we return zero. */
2807 optimize_bit_field_compare (code, compare_type, lhs, rhs)
2808 enum tree_code code;
2812 int lbitpos, lbitsize, rbitpos, rbitsize;
2813 int lnbitpos, lnbitsize, rnbitpos = 0, rnbitsize = 0;
2814 tree type = TREE_TYPE (lhs);
2815 tree signed_type, unsigned_type;
2816 int const_p = TREE_CODE (rhs) == INTEGER_CST;
2817 enum machine_mode lmode, rmode, lnmode, rnmode = VOIDmode;
2818 int lunsignedp, runsignedp;
2819 int lvolatilep = 0, rvolatilep = 0;
2821 tree linner, rinner = NULL_TREE;
2825 /* Get all the information about the extractions being done. If the bit size
2826 if the same as the size of the underlying object, we aren't doing an
2827 extraction at all and so can do nothing. We also don't want to
2828 do anything if the inner expression is a PLACEHOLDER_EXPR since we
2829 then will no longer be able to replace it. */
2830 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
2831 &lunsignedp, &lvolatilep, &alignment);
2832 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
2833 || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
2838 /* If this is not a constant, we can only do something if bit positions,
2839 sizes, and signedness are the same. */
2840 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
2841 &runsignedp, &rvolatilep, &alignment);
2843 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
2844 || lunsignedp != runsignedp || offset != 0
2845 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
2849 /* See if we can find a mode to refer to this field. We should be able to,
2850 but fail if we can't. */
2851 lnmode = get_best_mode (lbitsize, lbitpos,
2852 TYPE_ALIGN (TREE_TYPE (linner)), word_mode,
2854 if (lnmode == VOIDmode)
2857 /* Set signed and unsigned types of the precision of this mode for the
2859 signed_type = type_for_mode (lnmode, 0);
2860 unsigned_type = type_for_mode (lnmode, 1);
2864 rnmode = get_best_mode (rbitsize, rbitpos,
2865 TYPE_ALIGN (TREE_TYPE (rinner)), word_mode,
2867 if (rnmode == VOIDmode)
2871 /* Compute the bit position and size for the new reference and our offset
2872 within it. If the new reference is the same size as the original, we
2873 won't optimize anything, so return zero. */
2874 lnbitsize = GET_MODE_BITSIZE (lnmode);
2875 lnbitpos = lbitpos & ~ (lnbitsize - 1);
2876 lbitpos -= lnbitpos;
2877 if (lnbitsize == lbitsize)
2882 rnbitsize = GET_MODE_BITSIZE (rnmode);
2883 rnbitpos = rbitpos & ~ (rnbitsize - 1);
2884 rbitpos -= rnbitpos;
2885 if (rnbitsize == rbitsize)
2889 if (BYTES_BIG_ENDIAN)
2890 lbitpos = lnbitsize - lbitsize - lbitpos;
2892 /* Make the mask to be used against the extracted field. */
2893 mask = build_int_2 (~0, ~0);
2894 TREE_TYPE (mask) = unsigned_type;
2895 force_fit_type (mask, 0);
2896 mask = convert (unsigned_type, mask);
2897 mask = const_binop (LSHIFT_EXPR, mask, size_int (lnbitsize - lbitsize), 0);
2898 mask = const_binop (RSHIFT_EXPR, mask,
2899 size_int (lnbitsize - lbitsize - lbitpos), 0);
2902 /* If not comparing with constant, just rework the comparison
2904 return build (code, compare_type,
2905 build (BIT_AND_EXPR, unsigned_type,
2906 make_bit_field_ref (linner, unsigned_type,
2907 lnbitsize, lnbitpos, 1),
2909 build (BIT_AND_EXPR, unsigned_type,
2910 make_bit_field_ref (rinner, unsigned_type,
2911 rnbitsize, rnbitpos, 1),
2914 /* Otherwise, we are handling the constant case. See if the constant is too
2915 big for the field. Warn and return a tree of for 0 (false) if so. We do
2916 this not only for its own sake, but to avoid having to test for this
2917 error case below. If we didn't, we might generate wrong code.
2919 For unsigned fields, the constant shifted right by the field length should
2920 be all zero. For signed fields, the high-order bits should agree with
2925 if (! integer_zerop (const_binop (RSHIFT_EXPR,
2926 convert (unsigned_type, rhs),
2927 size_int (lbitsize), 0)))
2929 warning ("comparison is always %d due to width of bitfield",
2931 return convert (compare_type,
2933 ? integer_one_node : integer_zero_node));
2938 tree tem = const_binop (RSHIFT_EXPR, convert (signed_type, rhs),
2939 size_int (lbitsize - 1), 0);
2940 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
2942 warning ("comparison is always %d due to width of bitfield",
2944 return convert (compare_type,
2946 ? integer_one_node : integer_zero_node));
2950 /* Single-bit compares should always be against zero. */
2951 if (lbitsize == 1 && ! integer_zerop (rhs))
2953 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
2954 rhs = convert (type, integer_zero_node);
2957 /* Make a new bitfield reference, shift the constant over the
2958 appropriate number of bits and mask it with the computed mask
2959 (in case this was a signed field). If we changed it, make a new one. */
2960 lhs = make_bit_field_ref (linner, unsigned_type, lnbitsize, lnbitpos, 1);
2963 TREE_SIDE_EFFECTS (lhs) = 1;
2964 TREE_THIS_VOLATILE (lhs) = 1;
2967 rhs = fold (const_binop (BIT_AND_EXPR,
2968 const_binop (LSHIFT_EXPR,
2969 convert (unsigned_type, rhs),
2970 size_int (lbitpos), 0),
2973 return build (code, compare_type,
2974 build (BIT_AND_EXPR, unsigned_type, lhs, mask),
2978 /* Subroutine for fold_truthop: decode a field reference.
2980 If EXP is a comparison reference, we return the innermost reference.
2982 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
2983 set to the starting bit number.
2985 If the innermost field can be completely contained in a mode-sized
2986 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
2988 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
2989 otherwise it is not changed.
2991 *PUNSIGNEDP is set to the signedness of the field.
2993 *PMASK is set to the mask used. This is either contained in a
2994 BIT_AND_EXPR or derived from the width of the field.
2996 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
2998 Return 0 if this is not a component reference or is one that we can't
2999 do anything with. */
3002 decode_field_reference (exp, pbitsize, pbitpos, pmode, punsignedp,
3003 pvolatilep, pmask, pand_mask)
3005 int *pbitsize, *pbitpos;
3006 enum machine_mode *pmode;
3007 int *punsignedp, *pvolatilep;
3012 tree mask, inner, offset;
3017 /* All the optimizations using this function assume integer fields.
3018 There are problems with FP fields since the type_for_size call
3019 below can fail for, e.g., XFmode. */
3020 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
3025 if (TREE_CODE (exp) == BIT_AND_EXPR)
3027 and_mask = TREE_OPERAND (exp, 1);
3028 exp = TREE_OPERAND (exp, 0);
3029 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
3030 if (TREE_CODE (and_mask) != INTEGER_CST)
3035 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
3036 punsignedp, pvolatilep, &alignment);
3037 if ((inner == exp && and_mask == 0)
3038 || *pbitsize < 0 || offset != 0
3039 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
3042 /* Compute the mask to access the bitfield. */
3043 unsigned_type = type_for_size (*pbitsize, 1);
3044 precision = TYPE_PRECISION (unsigned_type);
3046 mask = build_int_2 (~0, ~0);
3047 TREE_TYPE (mask) = unsigned_type;
3048 force_fit_type (mask, 0);
3049 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3050 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3052 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
3054 mask = fold (build (BIT_AND_EXPR, unsigned_type,
3055 convert (unsigned_type, and_mask), mask));
3058 *pand_mask = and_mask;
3062 /* Return non-zero if MASK represents a mask of SIZE ones in the low-order
3066 all_ones_mask_p (mask, size)
3070 tree type = TREE_TYPE (mask);
3071 int precision = TYPE_PRECISION (type);
3074 tmask = build_int_2 (~0, ~0);
3075 TREE_TYPE (tmask) = signed_type (type);
3076 force_fit_type (tmask, 0);
3078 tree_int_cst_equal (mask,
3079 const_binop (RSHIFT_EXPR,
3080 const_binop (LSHIFT_EXPR, tmask,
3081 size_int (precision - size),
3083 size_int (precision - size), 0));
3086 /* Subroutine for fold_truthop: determine if an operand is simple enough
3087 to be evaluated unconditionally. */
3090 simple_operand_p (exp)
3093 /* Strip any conversions that don't change the machine mode. */
3094 while ((TREE_CODE (exp) == NOP_EXPR
3095 || TREE_CODE (exp) == CONVERT_EXPR)
3096 && (TYPE_MODE (TREE_TYPE (exp))
3097 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)))))
3098 exp = TREE_OPERAND (exp, 0);
3100 return (TREE_CODE_CLASS (TREE_CODE (exp)) == 'c'
3101 || (TREE_CODE_CLASS (TREE_CODE (exp)) == 'd'
3102 && ! TREE_ADDRESSABLE (exp)
3103 && ! TREE_THIS_VOLATILE (exp)
3104 && ! DECL_NONLOCAL (exp)
3105 /* Don't regard global variables as simple. They may be
3106 allocated in ways unknown to the compiler (shared memory,
3107 #pragma weak, etc). */
3108 && ! TREE_PUBLIC (exp)
3109 && ! DECL_EXTERNAL (exp)
3110 /* Loading a static variable is unduly expensive, but global
3111 registers aren't expensive. */
3112 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
3115 /* The following functions are subroutines to fold_range_test and allow it to
3116 try to change a logical combination of comparisons into a range test.
3119 X == 2 && X == 3 && X == 4 && X == 5
3123 (unsigned) (X - 2) <= 3
3125 We describe each set of comparisons as being either inside or outside
3126 a range, using a variable named like IN_P, and then describe the
3127 range with a lower and upper bound. If one of the bounds is omitted,
3128 it represents either the highest or lowest value of the type.
3130 In the comments below, we represent a range by two numbers in brackets
3131 preceded by a "+" to designate being inside that range, or a "-" to
3132 designate being outside that range, so the condition can be inverted by
3133 flipping the prefix. An omitted bound is represented by a "-". For
3134 example, "- [-, 10]" means being outside the range starting at the lowest
3135 possible value and ending at 10, in other words, being greater than 10.
3136 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
3139 We set up things so that the missing bounds are handled in a consistent
3140 manner so neither a missing bound nor "true" and "false" need to be
3141 handled using a special case. */
3143 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
3144 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
3145 and UPPER1_P are nonzero if the respective argument is an upper bound
3146 and zero for a lower. TYPE, if nonzero, is the type of the result; it
3147 must be specified for a comparison. ARG1 will be converted to ARG0's
3148 type if both are specified. */
3151 range_binop (code, type, arg0, upper0_p, arg1, upper1_p)
3152 enum tree_code code;
3155 int upper0_p, upper1_p;
3161 /* If neither arg represents infinity, do the normal operation.
3162 Else, if not a comparison, return infinity. Else handle the special
3163 comparison rules. Note that most of the cases below won't occur, but
3164 are handled for consistency. */
3166 if (arg0 != 0 && arg1 != 0)
3168 tem = fold (build (code, type != 0 ? type : TREE_TYPE (arg0),
3169 arg0, convert (TREE_TYPE (arg0), arg1)));
3171 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
3174 if (TREE_CODE_CLASS (code) != '<')
3177 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
3178 for neither. In real maths, we cannot assume open ended ranges are
3179 the same. But, this is computer arithmetic, where numbers are finite.
3180 We can therefore make the transformation of any unbounded range with
3181 the value Z, Z being greater than any representable number. This permits
3182 us to treat unbounded ranges as equal. */
3183 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
3184 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
3188 result = sgn0 == sgn1;
3191 result = sgn0 != sgn1;
3194 result = sgn0 < sgn1;
3197 result = sgn0 <= sgn1;
3200 result = sgn0 > sgn1;
3203 result = sgn0 >= sgn1;
3209 return convert (type, result ? integer_one_node : integer_zero_node);
3212 /* Given EXP, a logical expression, set the range it is testing into
3213 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
3214 actually being tested. *PLOW and *PHIGH will have be made the same type
3215 as the returned expression. If EXP is not a comparison, we will most
3216 likely not be returning a useful value and range. */
3219 make_range (exp, pin_p, plow, phigh)
3224 enum tree_code code;
3225 tree arg0 = NULL_TREE, arg1 = NULL_TREE, type = NULL_TREE;
3226 tree orig_type = NULL_TREE;
3228 tree low, high, n_low, n_high;
3230 /* Start with simply saying "EXP != 0" and then look at the code of EXP
3231 and see if we can refine the range. Some of the cases below may not
3232 happen, but it doesn't seem worth worrying about this. We "continue"
3233 the outer loop when we've changed something; otherwise we "break"
3234 the switch, which will "break" the while. */
3236 in_p = 0, low = high = convert (TREE_TYPE (exp), integer_zero_node);
3240 code = TREE_CODE (exp);
3242 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
3244 arg0 = TREE_OPERAND (exp, 0);
3245 if (TREE_CODE_CLASS (code) == '<'
3246 || TREE_CODE_CLASS (code) == '1'
3247 || TREE_CODE_CLASS (code) == '2')
3248 type = TREE_TYPE (arg0);
3249 if (TREE_CODE_CLASS (code) == '2'
3250 || TREE_CODE_CLASS (code) == '<'
3251 || (TREE_CODE_CLASS (code) == 'e'
3252 && tree_code_length[(int) code] > 1))
3253 arg1 = TREE_OPERAND (exp, 1);
3256 /* Set ORIG_TYPE as soon as TYPE is non-null so that we do not
3257 lose a cast by accident. */
3258 if (type != NULL_TREE && orig_type == NULL_TREE)
3263 case TRUTH_NOT_EXPR:
3264 in_p = ! in_p, exp = arg0;
3267 case EQ_EXPR: case NE_EXPR:
3268 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
3269 /* We can only do something if the range is testing for zero
3270 and if the second operand is an integer constant. Note that
3271 saying something is "in" the range we make is done by
3272 complementing IN_P since it will set in the initial case of
3273 being not equal to zero; "out" is leaving it alone. */
3274 if (low == 0 || high == 0
3275 || ! integer_zerop (low) || ! integer_zerop (high)
3276 || TREE_CODE (arg1) != INTEGER_CST)
3281 case NE_EXPR: /* - [c, c] */
3284 case EQ_EXPR: /* + [c, c] */
3285 in_p = ! in_p, low = high = arg1;
3287 case GT_EXPR: /* - [-, c] */
3288 low = 0, high = arg1;
3290 case GE_EXPR: /* + [c, -] */
3291 in_p = ! in_p, low = arg1, high = 0;
3293 case LT_EXPR: /* - [c, -] */
3294 low = arg1, high = 0;
3296 case LE_EXPR: /* + [-, c] */
3297 in_p = ! in_p, low = 0, high = arg1;
3305 /* If this is an unsigned comparison, we also know that EXP is
3306 greater than or equal to zero. We base the range tests we make
3307 on that fact, so we record it here so we can parse existing
3309 if (TREE_UNSIGNED (type) && (low == 0 || high == 0))
3311 if (! merge_ranges (&n_in_p, &n_low, &n_high, in_p, low, high,
3312 1, convert (type, integer_zero_node),
3316 in_p = n_in_p, low = n_low, high = n_high;
3318 /* If the high bound is missing, reverse the range so it
3319 goes from zero to the low bound minus 1. */
3323 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
3324 integer_one_node, 0);
3325 low = convert (type, integer_zero_node);
3331 /* (-x) IN [a,b] -> x in [-b, -a] */
3332 n_low = range_binop (MINUS_EXPR, type,
3333 convert (type, integer_zero_node), 0, high, 1);
3334 n_high = range_binop (MINUS_EXPR, type,
3335 convert (type, integer_zero_node), 0, low, 0);
3336 low = n_low, high = n_high;
3342 exp = build (MINUS_EXPR, type, negate_expr (arg0),
3343 convert (type, integer_one_node));
3346 case PLUS_EXPR: case MINUS_EXPR:
3347 if (TREE_CODE (arg1) != INTEGER_CST)
3350 /* If EXP is signed, any overflow in the computation is undefined,
3351 so we don't worry about it so long as our computations on
3352 the bounds don't overflow. For unsigned, overflow is defined
3353 and this is exactly the right thing. */
3354 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3355 type, low, 0, arg1, 0);
3356 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3357 type, high, 1, arg1, 0);
3358 if ((n_low != 0 && TREE_OVERFLOW (n_low))
3359 || (n_high != 0 && TREE_OVERFLOW (n_high)))
3362 /* Check for an unsigned range which has wrapped around the maximum
3363 value thus making n_high < n_low, and normalize it. */
3364 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
3366 low = range_binop (PLUS_EXPR, type, n_high, 0,
3367 integer_one_node, 0);
3368 high = range_binop (MINUS_EXPR, type, n_low, 0,
3369 integer_one_node, 0);
3373 low = n_low, high = n_high;
3378 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
3379 if (TYPE_PRECISION (type) > TYPE_PRECISION (orig_type))
3382 if (! INTEGRAL_TYPE_P (type)
3383 || (low != 0 && ! int_fits_type_p (low, type))
3384 || (high != 0 && ! int_fits_type_p (high, type)))
3387 n_low = low, n_high = high;
3390 n_low = convert (type, n_low);
3393 n_high = convert (type, n_high);
3395 /* If we're converting from an unsigned to a signed type,
3396 we will be doing the comparison as unsigned. The tests above
3397 have already verified that LOW and HIGH are both positive.
3399 So we have to make sure that the original unsigned value will
3400 be interpreted as positive. */
3401 if (TREE_UNSIGNED (type) && ! TREE_UNSIGNED (TREE_TYPE (exp)))
3403 tree equiv_type = type_for_mode (TYPE_MODE (type), 1);
3406 /* A range without an upper bound is, naturally, unbounded.
3407 Since convert would have cropped a very large value, use
3408 the max value for the destination type. */
3410 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
3411 : TYPE_MAX_VALUE (type);
3413 high_positive = fold (build (RSHIFT_EXPR, type,
3414 convert (type, high_positive),
3415 convert (type, integer_one_node)));
3417 /* If the low bound is specified, "and" the range with the
3418 range for which the original unsigned value will be
3422 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3424 1, convert (type, integer_zero_node),
3428 in_p = (n_in_p == in_p);
3432 /* Otherwise, "or" the range with the range of the input
3433 that will be interpreted as negative. */
3434 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3436 1, convert (type, integer_zero_node),
3440 in_p = (in_p != n_in_p);
3445 low = n_low, high = n_high;
3455 /* If EXP is a constant, we can evaluate whether this is true or false. */
3456 if (TREE_CODE (exp) == INTEGER_CST)
3458 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
3460 && integer_onep (range_binop (LE_EXPR, integer_type_node,
3466 *pin_p = in_p, *plow = low, *phigh = high;
3470 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3471 type, TYPE, return an expression to test if EXP is in (or out of, depending
3472 on IN_P) the range. */
3475 build_range_check (type, exp, in_p, low, high)
3481 tree etype = TREE_TYPE (exp);
3485 && (0 != (value = build_range_check (type, exp, 1, low, high))))
3486 return invert_truthvalue (value);
3488 else if (low == 0 && high == 0)
3489 return convert (type, integer_one_node);
3492 return fold (build (LE_EXPR, type, exp, high));
3495 return fold (build (GE_EXPR, type, exp, low));
3497 else if (operand_equal_p (low, high, 0))
3498 return fold (build (EQ_EXPR, type, exp, low));
3500 else if (TREE_UNSIGNED (etype) && integer_zerop (low))
3501 return build_range_check (type, exp, 1, 0, high);
3503 else if (integer_zerop (low))
3505 utype = unsigned_type (etype);
3506 return build_range_check (type, convert (utype, exp), 1, 0,
3507 convert (utype, high));
3510 else if (0 != (value = const_binop (MINUS_EXPR, high, low, 0))
3511 && ! TREE_OVERFLOW (value))
3512 return build_range_check (type,
3513 fold (build (MINUS_EXPR, etype, exp, low)),
3514 1, convert (etype, integer_zero_node), value);
3519 /* Given two ranges, see if we can merge them into one. Return 1 if we
3520 can, 0 if we can't. Set the output range into the specified parameters. */
3523 merge_ranges (pin_p, plow, phigh, in0_p, low0, high0, in1_p, low1, high1)
3527 tree low0, high0, low1, high1;
3535 int lowequal = ((low0 == 0 && low1 == 0)
3536 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3537 low0, 0, low1, 0)));
3538 int highequal = ((high0 == 0 && high1 == 0)
3539 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3540 high0, 1, high1, 1)));
3542 /* Make range 0 be the range that starts first, or ends last if they
3543 start at the same value. Swap them if it isn't. */
3544 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
3547 && integer_onep (range_binop (GT_EXPR, integer_type_node,
3548 high1, 1, high0, 1))))
3550 temp = in0_p, in0_p = in1_p, in1_p = temp;
3551 tem = low0, low0 = low1, low1 = tem;
3552 tem = high0, high0 = high1, high1 = tem;
3555 /* Now flag two cases, whether the ranges are disjoint or whether the
3556 second range is totally subsumed in the first. Note that the tests
3557 below are simplified by the ones above. */
3558 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
3559 high0, 1, low1, 0));
3560 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
3561 high1, 1, high0, 1));
3563 /* We now have four cases, depending on whether we are including or
3564 excluding the two ranges. */
3567 /* If they don't overlap, the result is false. If the second range
3568 is a subset it is the result. Otherwise, the range is from the start
3569 of the second to the end of the first. */
3571 in_p = 0, low = high = 0;
3573 in_p = 1, low = low1, high = high1;
3575 in_p = 1, low = low1, high = high0;
3578 else if (in0_p && ! in1_p)
3580 /* If they don't overlap, the result is the first range. If they are
3581 equal, the result is false. If the second range is a subset of the
3582 first, and the ranges begin at the same place, we go from just after
3583 the end of the first range to the end of the second. If the second
3584 range is not a subset of the first, or if it is a subset and both
3585 ranges end at the same place, the range starts at the start of the
3586 first range and ends just before the second range.
3587 Otherwise, we can't describe this as a single range. */
3589 in_p = 1, low = low0, high = high0;
3590 else if (lowequal && highequal)
3591 in_p = 0, low = high = 0;
3592 else if (subset && lowequal)
3594 in_p = 1, high = high0;
3595 low = range_binop (PLUS_EXPR, NULL_TREE, high1, 0,
3596 integer_one_node, 0);
3598 else if (! subset || highequal)
3600 in_p = 1, low = low0;
3601 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
3602 integer_one_node, 0);
3608 else if (! in0_p && in1_p)
3610 /* If they don't overlap, the result is the second range. If the second
3611 is a subset of the first, the result is false. Otherwise,
3612 the range starts just after the first range and ends at the
3613 end of the second. */
3615 in_p = 1, low = low1, high = high1;
3616 else if (subset || highequal)
3617 in_p = 0, low = high = 0;
3620 in_p = 1, high = high1;
3621 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
3622 integer_one_node, 0);
3628 /* The case where we are excluding both ranges. Here the complex case
3629 is if they don't overlap. In that case, the only time we have a
3630 range is if they are adjacent. If the second is a subset of the
3631 first, the result is the first. Otherwise, the range to exclude
3632 starts at the beginning of the first range and ends at the end of the
3636 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
3637 range_binop (PLUS_EXPR, NULL_TREE,
3639 integer_one_node, 1),
3641 in_p = 0, low = low0, high = high1;
3646 in_p = 0, low = low0, high = high0;
3648 in_p = 0, low = low0, high = high1;
3651 *pin_p = in_p, *plow = low, *phigh = high;
3655 /* EXP is some logical combination of boolean tests. See if we can
3656 merge it into some range test. Return the new tree if so. */
3659 fold_range_test (exp)
3662 int or_op = (TREE_CODE (exp) == TRUTH_ORIF_EXPR
3663 || TREE_CODE (exp) == TRUTH_OR_EXPR);
3664 int in0_p, in1_p, in_p;
3665 tree low0, low1, low, high0, high1, high;
3666 tree lhs = make_range (TREE_OPERAND (exp, 0), &in0_p, &low0, &high0);
3667 tree rhs = make_range (TREE_OPERAND (exp, 1), &in1_p, &low1, &high1);
3670 /* If this is an OR operation, invert both sides; we will invert
3671 again at the end. */
3673 in0_p = ! in0_p, in1_p = ! in1_p;
3675 /* If both expressions are the same, if we can merge the ranges, and we
3676 can build the range test, return it or it inverted. If one of the
3677 ranges is always true or always false, consider it to be the same
3678 expression as the other. */
3679 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
3680 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
3682 && 0 != (tem = (build_range_check (TREE_TYPE (exp),
3684 : rhs != 0 ? rhs : integer_zero_node,
3686 return or_op ? invert_truthvalue (tem) : tem;
3688 /* On machines where the branch cost is expensive, if this is a
3689 short-circuited branch and the underlying object on both sides
3690 is the same, make a non-short-circuit operation. */
3691 else if (BRANCH_COST >= 2
3692 && (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3693 || TREE_CODE (exp) == TRUTH_ORIF_EXPR)
3694 && operand_equal_p (lhs, rhs, 0))
3696 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
3697 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
3698 which cases we can't do this. */
3699 if (simple_operand_p (lhs))
3700 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3701 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3702 TREE_TYPE (exp), TREE_OPERAND (exp, 0),
3703 TREE_OPERAND (exp, 1));
3705 else if (global_bindings_p () == 0
3706 && ! contains_placeholder_p (lhs))
3708 tree common = save_expr (lhs);
3710 if (0 != (lhs = build_range_check (TREE_TYPE (exp), common,
3711 or_op ? ! in0_p : in0_p,
3713 && (0 != (rhs = build_range_check (TREE_TYPE (exp), common,
3714 or_op ? ! in1_p : in1_p,
3716 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3717 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3718 TREE_TYPE (exp), lhs, rhs);
3725 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
3726 bit value. Arrange things so the extra bits will be set to zero if and
3727 only if C is signed-extended to its full width. If MASK is nonzero,
3728 it is an INTEGER_CST that should be AND'ed with the extra bits. */
3731 unextend (c, p, unsignedp, mask)
3737 tree type = TREE_TYPE (c);
3738 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
3741 if (p == modesize || unsignedp)
3744 /* We work by getting just the sign bit into the low-order bit, then
3745 into the high-order bit, then sign-extend. We then XOR that value
3747 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
3748 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
3750 /* We must use a signed type in order to get an arithmetic right shift.
3751 However, we must also avoid introducing accidental overflows, so that
3752 a subsequent call to integer_zerop will work. Hence we must
3753 do the type conversion here. At this point, the constant is either
3754 zero or one, and the conversion to a signed type can never overflow.
3755 We could get an overflow if this conversion is done anywhere else. */
3756 if (TREE_UNSIGNED (type))
3757 temp = convert (signed_type (type), temp);
3759 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
3760 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
3762 temp = const_binop (BIT_AND_EXPR, temp, convert (TREE_TYPE (c), mask), 0);
3763 /* If necessary, convert the type back to match the type of C. */
3764 if (TREE_UNSIGNED (type))
3765 temp = convert (type, temp);
3767 return convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
3770 /* Find ways of folding logical expressions of LHS and RHS:
3771 Try to merge two comparisons to the same innermost item.
3772 Look for range tests like "ch >= '0' && ch <= '9'".
3773 Look for combinations of simple terms on machines with expensive branches
3774 and evaluate the RHS unconditionally.
3776 For example, if we have p->a == 2 && p->b == 4 and we can make an
3777 object large enough to span both A and B, we can do this with a comparison
3778 against the object ANDed with the a mask.
3780 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
3781 operations to do this with one comparison.
3783 We check for both normal comparisons and the BIT_AND_EXPRs made this by
3784 function and the one above.
3786 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
3787 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
3789 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
3792 We return the simplified tree or 0 if no optimization is possible. */
3795 fold_truthop (code, truth_type, lhs, rhs)
3796 enum tree_code code;
3797 tree truth_type, lhs, rhs;
3799 /* If this is the "or" of two comparisons, we can do something if we
3800 the comparisons are NE_EXPR. If this is the "and", we can do something
3801 if the comparisons are EQ_EXPR. I.e.,
3802 (a->b == 2 && a->c == 4) can become (a->new == NEW).
3804 WANTED_CODE is this operation code. For single bit fields, we can
3805 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
3806 comparison for one-bit fields. */
3808 enum tree_code wanted_code;
3809 enum tree_code lcode, rcode;
3810 tree ll_arg, lr_arg, rl_arg, rr_arg;
3811 tree ll_inner, lr_inner, rl_inner, rr_inner;
3812 int ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
3813 int rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
3814 int xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
3815 int lnbitsize, lnbitpos, rnbitsize, rnbitpos;
3816 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
3817 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
3818 enum machine_mode lnmode, rnmode;
3819 tree ll_mask, lr_mask, rl_mask, rr_mask;
3820 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
3821 tree l_const, r_const;
3822 tree lntype, rntype, result;
3823 int first_bit, end_bit;
3826 /* Start by getting the comparison codes. Fail if anything is volatile.
3827 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
3828 it were surrounded with a NE_EXPR. */
3830 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
3833 lcode = TREE_CODE (lhs);
3834 rcode = TREE_CODE (rhs);
3836 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
3837 lcode = NE_EXPR, lhs = build (NE_EXPR, truth_type, lhs, integer_zero_node);
3839 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
3840 rcode = NE_EXPR, rhs = build (NE_EXPR, truth_type, rhs, integer_zero_node);
3842 if (TREE_CODE_CLASS (lcode) != '<' || TREE_CODE_CLASS (rcode) != '<')
3845 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
3846 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
3848 ll_arg = TREE_OPERAND (lhs, 0);
3849 lr_arg = TREE_OPERAND (lhs, 1);
3850 rl_arg = TREE_OPERAND (rhs, 0);
3851 rr_arg = TREE_OPERAND (rhs, 1);
3853 /* If the RHS can be evaluated unconditionally and its operands are
3854 simple, it wins to evaluate the RHS unconditionally on machines
3855 with expensive branches. In this case, this isn't a comparison
3856 that can be merged. */
3858 /* @@ I'm not sure it wins on the m88110 to do this if the comparisons
3859 are with zero (tmw). */
3861 if (BRANCH_COST >= 2
3862 && INTEGRAL_TYPE_P (TREE_TYPE (rhs))
3863 && simple_operand_p (rl_arg)
3864 && simple_operand_p (rr_arg))
3865 return build (code, truth_type, lhs, rhs);
3867 /* See if the comparisons can be merged. Then get all the parameters for
3870 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
3871 || (rcode != EQ_EXPR && rcode != NE_EXPR))
3875 ll_inner = decode_field_reference (ll_arg,
3876 &ll_bitsize, &ll_bitpos, &ll_mode,
3877 &ll_unsignedp, &volatilep, &ll_mask,
3879 lr_inner = decode_field_reference (lr_arg,
3880 &lr_bitsize, &lr_bitpos, &lr_mode,
3881 &lr_unsignedp, &volatilep, &lr_mask,
3883 rl_inner = decode_field_reference (rl_arg,
3884 &rl_bitsize, &rl_bitpos, &rl_mode,
3885 &rl_unsignedp, &volatilep, &rl_mask,
3887 rr_inner = decode_field_reference (rr_arg,
3888 &rr_bitsize, &rr_bitpos, &rr_mode,
3889 &rr_unsignedp, &volatilep, &rr_mask,
3892 /* It must be true that the inner operation on the lhs of each
3893 comparison must be the same if we are to be able to do anything.
3894 Then see if we have constants. If not, the same must be true for
3896 if (volatilep || ll_inner == 0 || rl_inner == 0
3897 || ! operand_equal_p (ll_inner, rl_inner, 0))
3900 if (TREE_CODE (lr_arg) == INTEGER_CST
3901 && TREE_CODE (rr_arg) == INTEGER_CST)
3902 l_const = lr_arg, r_const = rr_arg;
3903 else if (lr_inner == 0 || rr_inner == 0
3904 || ! operand_equal_p (lr_inner, rr_inner, 0))
3907 l_const = r_const = 0;
3909 /* If either comparison code is not correct for our logical operation,
3910 fail. However, we can convert a one-bit comparison against zero into
3911 the opposite comparison against that bit being set in the field. */
3913 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
3914 if (lcode != wanted_code)
3916 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
3918 /* Make the left operand unsigned, since we are only interested
3919 in the value of one bit. Otherwise we are doing the wrong
3928 /* This is analogous to the code for l_const above. */
3929 if (rcode != wanted_code)
3931 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
3940 /* See if we can find a mode that contains both fields being compared on
3941 the left. If we can't, fail. Otherwise, update all constants and masks
3942 to be relative to a field of that size. */
3943 first_bit = MIN (ll_bitpos, rl_bitpos);
3944 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
3945 lnmode = get_best_mode (end_bit - first_bit, first_bit,
3946 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
3948 if (lnmode == VOIDmode)
3951 lnbitsize = GET_MODE_BITSIZE (lnmode);
3952 lnbitpos = first_bit & ~ (lnbitsize - 1);
3953 lntype = type_for_size (lnbitsize, 1);
3954 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
3956 if (BYTES_BIG_ENDIAN)
3958 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
3959 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
3962 ll_mask = const_binop (LSHIFT_EXPR, convert (lntype, ll_mask),
3963 size_int (xll_bitpos), 0);
3964 rl_mask = const_binop (LSHIFT_EXPR, convert (lntype, rl_mask),
3965 size_int (xrl_bitpos), 0);
3969 l_const = convert (lntype, l_const);
3970 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
3971 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
3972 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
3973 fold (build1 (BIT_NOT_EXPR,
3977 warning ("comparison is always %d", wanted_code == NE_EXPR);
3979 return convert (truth_type,
3980 wanted_code == NE_EXPR
3981 ? integer_one_node : integer_zero_node);
3986 r_const = convert (lntype, r_const);
3987 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
3988 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
3989 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
3990 fold (build1 (BIT_NOT_EXPR,
3994 warning ("comparison is always %d", wanted_code == NE_EXPR);
3996 return convert (truth_type,
3997 wanted_code == NE_EXPR
3998 ? integer_one_node : integer_zero_node);
4002 /* If the right sides are not constant, do the same for it. Also,
4003 disallow this optimization if a size or signedness mismatch occurs
4004 between the left and right sides. */
4007 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
4008 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
4009 /* Make sure the two fields on the right
4010 correspond to the left without being swapped. */
4011 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
4014 first_bit = MIN (lr_bitpos, rr_bitpos);
4015 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
4016 rnmode = get_best_mode (end_bit - first_bit, first_bit,
4017 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
4019 if (rnmode == VOIDmode)
4022 rnbitsize = GET_MODE_BITSIZE (rnmode);
4023 rnbitpos = first_bit & ~ (rnbitsize - 1);
4024 rntype = type_for_size (rnbitsize, 1);
4025 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
4027 if (BYTES_BIG_ENDIAN)
4029 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
4030 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
4033 lr_mask = const_binop (LSHIFT_EXPR, convert (rntype, lr_mask),
4034 size_int (xlr_bitpos), 0);
4035 rr_mask = const_binop (LSHIFT_EXPR, convert (rntype, rr_mask),
4036 size_int (xrr_bitpos), 0);
4038 /* Make a mask that corresponds to both fields being compared.
4039 Do this for both items being compared. If the operands are the
4040 same size and the bits being compared are in the same position
4041 then we can do this by masking both and comparing the masked
4043 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4044 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
4045 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
4047 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4048 ll_unsignedp || rl_unsignedp);
4049 if (! all_ones_mask_p (ll_mask, lnbitsize))
4050 lhs = build (BIT_AND_EXPR, lntype, lhs, ll_mask);
4052 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
4053 lr_unsignedp || rr_unsignedp);
4054 if (! all_ones_mask_p (lr_mask, rnbitsize))
4055 rhs = build (BIT_AND_EXPR, rntype, rhs, lr_mask);
4057 return build (wanted_code, truth_type, lhs, rhs);
4060 /* There is still another way we can do something: If both pairs of
4061 fields being compared are adjacent, we may be able to make a wider
4062 field containing them both.
4064 Note that we still must mask the lhs/rhs expressions. Furthermore,
4065 the mask must be shifted to account for the shift done by
4066 make_bit_field_ref. */
4067 if ((ll_bitsize + ll_bitpos == rl_bitpos
4068 && lr_bitsize + lr_bitpos == rr_bitpos)
4069 || (ll_bitpos == rl_bitpos + rl_bitsize
4070 && lr_bitpos == rr_bitpos + rr_bitsize))
4074 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
4075 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
4076 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
4077 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
4079 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
4080 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
4081 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
4082 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
4084 /* Convert to the smaller type before masking out unwanted bits. */
4086 if (lntype != rntype)
4088 if (lnbitsize > rnbitsize)
4090 lhs = convert (rntype, lhs);
4091 ll_mask = convert (rntype, ll_mask);
4094 else if (lnbitsize < rnbitsize)
4096 rhs = convert (lntype, rhs);
4097 lr_mask = convert (lntype, lr_mask);
4102 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
4103 lhs = build (BIT_AND_EXPR, type, lhs, ll_mask);
4105 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
4106 rhs = build (BIT_AND_EXPR, type, rhs, lr_mask);
4108 return build (wanted_code, truth_type, lhs, rhs);
4114 /* Handle the case of comparisons with constants. If there is something in
4115 common between the masks, those bits of the constants must be the same.
4116 If not, the condition is always false. Test for this to avoid generating
4117 incorrect code below. */
4118 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
4119 if (! integer_zerop (result)
4120 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
4121 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
4123 if (wanted_code == NE_EXPR)
4125 warning ("`or' of unmatched not-equal tests is always 1");
4126 return convert (truth_type, integer_one_node);
4130 warning ("`and' of mutually exclusive equal-tests is always 0");
4131 return convert (truth_type, integer_zero_node);
4135 /* Construct the expression we will return. First get the component
4136 reference we will make. Unless the mask is all ones the width of
4137 that field, perform the mask operation. Then compare with the
4139 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4140 ll_unsignedp || rl_unsignedp);
4142 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4143 if (! all_ones_mask_p (ll_mask, lnbitsize))
4144 result = build (BIT_AND_EXPR, lntype, result, ll_mask);
4146 return build (wanted_code, truth_type, result,
4147 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
4150 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
4154 optimize_minmax_comparison (t)
4157 tree type = TREE_TYPE (t);
4158 tree arg0 = TREE_OPERAND (t, 0);
4159 enum tree_code op_code;
4160 tree comp_const = TREE_OPERAND (t, 1);
4162 int consts_equal, consts_lt;
4165 STRIP_SIGN_NOPS (arg0);
4167 op_code = TREE_CODE (arg0);
4168 minmax_const = TREE_OPERAND (arg0, 1);
4169 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
4170 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
4171 inner = TREE_OPERAND (arg0, 0);
4173 /* If something does not permit us to optimize, return the original tree. */
4174 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
4175 || TREE_CODE (comp_const) != INTEGER_CST
4176 || TREE_CONSTANT_OVERFLOW (comp_const)
4177 || TREE_CODE (minmax_const) != INTEGER_CST
4178 || TREE_CONSTANT_OVERFLOW (minmax_const))
4181 /* Now handle all the various comparison codes. We only handle EQ_EXPR
4182 and GT_EXPR, doing the rest with recursive calls using logical
4184 switch (TREE_CODE (t))
4186 case NE_EXPR: case LT_EXPR: case LE_EXPR:
4188 invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t)));
4192 fold (build (TRUTH_ORIF_EXPR, type,
4193 optimize_minmax_comparison
4194 (build (EQ_EXPR, type, arg0, comp_const)),
4195 optimize_minmax_comparison
4196 (build (GT_EXPR, type, arg0, comp_const))));
4199 if (op_code == MAX_EXPR && consts_equal)
4200 /* MAX (X, 0) == 0 -> X <= 0 */
4201 return fold (build (LE_EXPR, type, inner, comp_const));
4203 else if (op_code == MAX_EXPR && consts_lt)
4204 /* MAX (X, 0) == 5 -> X == 5 */
4205 return fold (build (EQ_EXPR, type, inner, comp_const));
4207 else if (op_code == MAX_EXPR)
4208 /* MAX (X, 0) == -1 -> false */
4209 return omit_one_operand (type, integer_zero_node, inner);
4211 else if (consts_equal)
4212 /* MIN (X, 0) == 0 -> X >= 0 */
4213 return fold (build (GE_EXPR, type, inner, comp_const));
4216 /* MIN (X, 0) == 5 -> false */
4217 return omit_one_operand (type, integer_zero_node, inner);
4220 /* MIN (X, 0) == -1 -> X == -1 */
4221 return fold (build (EQ_EXPR, type, inner, comp_const));
4224 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
4225 /* MAX (X, 0) > 0 -> X > 0
4226 MAX (X, 0) > 5 -> X > 5 */
4227 return fold (build (GT_EXPR, type, inner, comp_const));
4229 else if (op_code == MAX_EXPR)
4230 /* MAX (X, 0) > -1 -> true */
4231 return omit_one_operand (type, integer_one_node, inner);
4233 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
4234 /* MIN (X, 0) > 0 -> false
4235 MIN (X, 0) > 5 -> false */
4236 return omit_one_operand (type, integer_zero_node, inner);
4239 /* MIN (X, 0) > -1 -> X > -1 */
4240 return fold (build (GT_EXPR, type, inner, comp_const));
4247 /* T is an integer expression that is being multiplied, divided, or taken a
4248 modulus (CODE says which and what kind of divide or modulus) by a
4249 constant C. See if we can eliminate that operation by folding it with
4250 other operations already in T. WIDE_TYPE, if non-null, is a type that
4251 should be used for the computation if wider than our type.
4253 For example, if we are dividing (X * 8) + (Y + 16) by 4, we can return
4254 (X * 2) + (Y + 4). We also canonicalize (X + 7) * 4 into X * 4 + 28
4255 in the hope that either the machine has a multiply-accumulate insn
4256 or that this is part of an addressing calculation.
4258 If we return a non-null expression, it is an equivalent form of the
4259 original computation, but need not be in the original type. */
4262 extract_muldiv (t, c, code, wide_type)
4265 enum tree_code code;
4268 tree type = TREE_TYPE (t);
4269 enum tree_code tcode = TREE_CODE (t);
4270 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
4271 > GET_MODE_SIZE (TYPE_MODE (type)))
4272 ? wide_type : type);
4274 int same_p = tcode == code;
4277 /* Don't deal with constants of zero here; they confuse the code below. */
4278 if (integer_zerop (c))
4281 if (TREE_CODE_CLASS (tcode) == '1')
4282 op0 = TREE_OPERAND (t, 0);
4284 if (TREE_CODE_CLASS (tcode) == '2')
4285 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
4287 /* Note that we need not handle conditional operations here since fold
4288 already handles those cases. So just do arithmetic here. */
4292 /* For a constant, we can always simplify if we are a multiply
4293 or (for divide and modulus) if it is a multiple of our constant. */
4294 if (code == MULT_EXPR
4295 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
4296 return const_binop (code, convert (ctype, t), convert (ctype, c), 0);
4299 case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
4301 /* Pass the constant down and see if we can make a simplification. If
4302 we can, replace this expression with the inner simplification for
4303 possible later conversion to our or some other type. */
4304 if (0 != (t1 = extract_muldiv (op0, convert (TREE_TYPE (op0), c), code,
4305 code == MULT_EXPR ? ctype : NULL_TREE)))
4309 case NEGATE_EXPR: case ABS_EXPR:
4310 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4311 return fold (build1 (tcode, ctype, convert (ctype, t1)));
4314 case MIN_EXPR: case MAX_EXPR:
4315 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
4316 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0
4317 && (t2 = extract_muldiv (op1, c, code, wide_type)) != 0)
4319 if (tree_int_cst_sgn (c) < 0)
4320 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
4322 return fold (build (tcode, ctype, convert (ctype, t1),
4323 convert (ctype, t2)));
4327 case WITH_RECORD_EXPR:
4328 if ((t1 = extract_muldiv (TREE_OPERAND (t, 0), c, code, wide_type)) != 0)
4329 return build (WITH_RECORD_EXPR, TREE_TYPE (t1), t1,
4330 TREE_OPERAND (t, 1));
4334 /* If this has not been evaluated and the operand has no side effects,
4335 we can see if we can do something inside it and make a new one.
4336 Note that this test is overly conservative since we can do this
4337 if the only reason it had side effects is that it was another
4338 similar SAVE_EXPR, but that isn't worth bothering with. */
4339 if (SAVE_EXPR_RTL (t) == 0 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0))
4340 && 0 != (t1 = extract_muldiv (TREE_OPERAND (t, 0), c, code,
4342 return save_expr (t1);
4345 case LSHIFT_EXPR: case RSHIFT_EXPR:
4346 /* If the second operand is constant, this is a multiplication
4347 or floor division, by a power of two, so we can treat it that
4348 way unless the multiplier or divisor overflows. */
4349 if (TREE_CODE (op1) == INTEGER_CST
4350 && 0 != (t1 = convert (ctype,
4351 const_binop (LSHIFT_EXPR, size_one_node,
4353 && ! TREE_OVERFLOW (t1))
4354 return extract_muldiv (build (tcode == LSHIFT_EXPR
4355 ? MULT_EXPR : FLOOR_DIV_EXPR,
4356 ctype, convert (ctype, op0), t1),
4357 c, code, wide_type);
4360 case PLUS_EXPR: case MINUS_EXPR:
4361 /* See if we can eliminate the operation on both sides. If we can, we
4362 can return a new PLUS or MINUS. If we can't, the only remaining
4363 cases where we can do anything are if the second operand is a
4365 t1 = extract_muldiv (op0, c, code, wide_type);
4366 t2 = extract_muldiv (op1, c, code, wide_type);
4367 if (t1 != 0 && t2 != 0)
4368 return fold (build (tcode, ctype, convert (ctype, t1),
4369 convert (ctype, t2)));
4371 /* If this was a subtraction, negate OP1 and set it to be an addition.
4372 This simplifies the logic below. */
4373 if (tcode == MINUS_EXPR)
4374 tcode = PLUS_EXPR, op1 = negate_expr (op1);
4376 if (TREE_CODE (op1) != INTEGER_CST)
4379 /* If either OP1 or C are negative, this optimization is not safe for
4380 some of the division and remainder types while for others we need
4381 to change the code. */
4382 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
4384 if (code == CEIL_DIV_EXPR)
4385 code = FLOOR_DIV_EXPR;
4386 else if (code == CEIL_MOD_EXPR)
4387 code = FLOOR_MOD_EXPR;
4388 else if (code == FLOOR_DIV_EXPR)
4389 code = CEIL_DIV_EXPR;
4390 else if (code == FLOOR_MOD_EXPR)
4391 code = CEIL_MOD_EXPR;
4392 else if (code != MULT_EXPR)
4396 /* Now do the operation and verify it doesn't overflow. */
4397 op1 = const_binop (code, convert (ctype, op1), convert (ctype, c), 0);
4398 if (op1 == 0 || TREE_OVERFLOW (op1))
4401 /* If we were able to eliminate our operation from the first side,
4402 apply our operation to the second side and reform the PLUS. */
4403 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
4404 return fold (build (tcode, ctype, convert (ctype, t1), op1));
4406 /* The last case is if we are a multiply. In that case, we can
4407 apply the distributive law to commute the multiply and addition
4408 if the multiplication of the constants doesn't overflow. */
4409 if (code == MULT_EXPR)
4410 return fold (build (tcode, ctype, fold (build (code, ctype,
4411 convert (ctype, op0),
4412 convert (ctype, c))),
4418 /* We have a special case here if we are doing something like
4419 (C * 8) % 4 since we know that's zero. */
4420 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
4421 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
4422 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
4423 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4424 return omit_one_operand (type, integer_zero_node, op0);
4426 /* ... fall through ... */
4428 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
4429 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
4430 /* If we can extract our operation from the LHS, do so and return a
4431 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
4432 do something only if the second operand is a constant. */
4434 && (t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4435 return fold (build (tcode, ctype, convert (ctype, t1),
4436 convert (ctype, op1)));
4437 else if (tcode == MULT_EXPR && code == MULT_EXPR
4438 && (t1 = extract_muldiv (op1, c, code, wide_type)) != 0)
4439 return fold (build (tcode, ctype, convert (ctype, op0),
4440 convert (ctype, t1)));
4441 else if (TREE_CODE (op1) != INTEGER_CST)
4444 /* If these are the same operation types, we can associate them
4445 assuming no overflow. */
4447 && 0 != (t1 = const_binop (MULT_EXPR, convert (ctype, op1),
4448 convert (ctype, c), 0))
4449 && ! TREE_OVERFLOW (t1))
4450 return fold (build (tcode, ctype, convert (ctype, op0), t1));
4452 /* If these operations "cancel" each other, we have the main
4453 optimizations of this pass, which occur when either constant is a
4454 multiple of the other, in which case we replace this with either an
4455 operation or CODE or TCODE. */
4456 if ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
4457 || (tcode == MULT_EXPR
4458 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
4459 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR))
4461 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4462 return fold (build (tcode, ctype, convert (ctype, op0),
4464 const_binop (TRUNC_DIV_EXPR,
4466 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
4467 return fold (build (code, ctype, convert (ctype, op0),
4469 const_binop (TRUNC_DIV_EXPR,
4481 /* If T contains a COMPOUND_EXPR which was inserted merely to evaluate
4482 S, a SAVE_EXPR, return the expression actually being evaluated. Note
4483 that we may sometimes modify the tree. */
4486 strip_compound_expr (t, s)
4490 enum tree_code code = TREE_CODE (t);
4492 /* See if this is the COMPOUND_EXPR we want to eliminate. */
4493 if (code == COMPOUND_EXPR && TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR
4494 && TREE_OPERAND (TREE_OPERAND (t, 0), 0) == s)
4495 return TREE_OPERAND (t, 1);
4497 /* See if this is a COND_EXPR or a simple arithmetic operator. We
4498 don't bother handling any other types. */
4499 else if (code == COND_EXPR)
4501 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4502 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4503 TREE_OPERAND (t, 2) = strip_compound_expr (TREE_OPERAND (t, 2), s);
4505 else if (TREE_CODE_CLASS (code) == '1')
4506 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4507 else if (TREE_CODE_CLASS (code) == '<'
4508 || TREE_CODE_CLASS (code) == '2')
4510 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4511 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4517 /* Return a node which has the indicated constant VALUE (either 0 or
4518 1), and is of the indicated TYPE. */
4521 constant_boolean_node (value, type)
4525 if (type == integer_type_node)
4526 return value ? integer_one_node : integer_zero_node;
4527 else if (TREE_CODE (type) == BOOLEAN_TYPE)
4528 return truthvalue_conversion (value ? integer_one_node :
4532 tree t = build_int_2 (value, 0);
4533 TREE_TYPE (t) = type;
4538 /* Utility function for the following routine, to see how complex a nesting of
4539 COND_EXPRs can be. EXPR is the expression and LIMIT is a count beyond which
4540 we don't care (to avoid spending too much time on complex expressions.). */
4543 count_cond (expr, lim)
4549 if (TREE_CODE (expr) != COND_EXPR)
4554 true = count_cond (TREE_OPERAND (expr, 1), lim - 1);
4555 false = count_cond (TREE_OPERAND (expr, 2), lim - 1 - true);
4556 return MIN (lim, 1 + true + false);
4559 /* Perform constant folding and related simplification of EXPR.
4560 The related simplifications include x*1 => x, x*0 => 0, etc.,
4561 and application of the associative law.
4562 NOP_EXPR conversions may be removed freely (as long as we
4563 are careful not to change the C type of the overall expression)
4564 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
4565 but we can constant-fold them if they have constant operands. */
4571 register tree t = expr;
4572 tree t1 = NULL_TREE;
4574 tree type = TREE_TYPE (expr);
4575 register tree arg0 = NULL_TREE, arg1 = NULL_TREE;
4576 register enum tree_code code = TREE_CODE (t);
4580 /* WINS will be nonzero when the switch is done
4581 if all operands are constant. */
4585 /* Don't try to process an RTL_EXPR since its operands aren't trees.
4586 Likewise for a SAVE_EXPR that's already been evaluated. */
4587 if (code == RTL_EXPR || (code == SAVE_EXPR && SAVE_EXPR_RTL (t)) != 0)
4590 /* Return right away if already constant. */
4591 if (TREE_CONSTANT (t))
4593 if (code == CONST_DECL)
4594 return DECL_INITIAL (t);
4598 #ifdef MAX_INTEGER_COMPUTATION_MODE
4599 check_max_integer_computation_mode (expr);
4602 kind = TREE_CODE_CLASS (code);
4603 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
4607 /* Special case for conversion ops that can have fixed point args. */
4608 arg0 = TREE_OPERAND (t, 0);
4610 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
4612 STRIP_SIGN_NOPS (arg0);
4614 if (arg0 != 0 && TREE_CODE (arg0) == COMPLEX_CST)
4615 subop = TREE_REALPART (arg0);
4619 if (subop != 0 && TREE_CODE (subop) != INTEGER_CST
4620 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
4621 && TREE_CODE (subop) != REAL_CST
4622 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
4624 /* Note that TREE_CONSTANT isn't enough:
4625 static var addresses are constant but we can't
4626 do arithmetic on them. */
4629 else if (kind == 'e' || kind == '<'
4630 || kind == '1' || kind == '2' || kind == 'r')
4632 register int len = tree_code_length[(int) code];
4634 for (i = 0; i < len; i++)
4636 tree op = TREE_OPERAND (t, i);
4640 continue; /* Valid for CALL_EXPR, at least. */
4642 if (kind == '<' || code == RSHIFT_EXPR)
4644 /* Signedness matters here. Perhaps we can refine this
4646 STRIP_SIGN_NOPS (op);
4650 /* Strip any conversions that don't change the mode. */
4654 if (TREE_CODE (op) == COMPLEX_CST)
4655 subop = TREE_REALPART (op);
4659 if (TREE_CODE (subop) != INTEGER_CST
4660 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
4661 && TREE_CODE (subop) != REAL_CST
4662 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
4664 /* Note that TREE_CONSTANT isn't enough:
4665 static var addresses are constant but we can't
4666 do arithmetic on them. */
4676 /* If this is a commutative operation, and ARG0 is a constant, move it
4677 to ARG1 to reduce the number of tests below. */
4678 if ((code == PLUS_EXPR || code == MULT_EXPR || code == MIN_EXPR
4679 || code == MAX_EXPR || code == BIT_IOR_EXPR || code == BIT_XOR_EXPR
4680 || code == BIT_AND_EXPR)
4681 && (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST))
4683 tem = arg0; arg0 = arg1; arg1 = tem;
4685 tem = TREE_OPERAND (t, 0); TREE_OPERAND (t, 0) = TREE_OPERAND (t, 1);
4686 TREE_OPERAND (t, 1) = tem;
4689 /* Now WINS is set as described above,
4690 ARG0 is the first operand of EXPR,
4691 and ARG1 is the second operand (if it has more than one operand).
4693 First check for cases where an arithmetic operation is applied to a
4694 compound, conditional, or comparison operation. Push the arithmetic
4695 operation inside the compound or conditional to see if any folding
4696 can then be done. Convert comparison to conditional for this purpose.
4697 The also optimizes non-constant cases that used to be done in
4700 Before we do that, see if this is a BIT_AND_EXPR or a BIT_OR_EXPR,
4701 one of the operands is a comparison and the other is a comparison, a
4702 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
4703 code below would make the expression more complex. Change it to a
4704 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
4705 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
4707 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
4708 || code == EQ_EXPR || code == NE_EXPR)
4709 && ((truth_value_p (TREE_CODE (arg0))
4710 && (truth_value_p (TREE_CODE (arg1))
4711 || (TREE_CODE (arg1) == BIT_AND_EXPR
4712 && integer_onep (TREE_OPERAND (arg1, 1)))))
4713 || (truth_value_p (TREE_CODE (arg1))
4714 && (truth_value_p (TREE_CODE (arg0))
4715 || (TREE_CODE (arg0) == BIT_AND_EXPR
4716 && integer_onep (TREE_OPERAND (arg0, 1)))))))
4718 t = fold (build (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
4719 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
4723 if (code == EQ_EXPR)
4724 t = invert_truthvalue (t);
4729 if (TREE_CODE_CLASS (code) == '1')
4731 if (TREE_CODE (arg0) == COMPOUND_EXPR)
4732 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
4733 fold (build1 (code, type, TREE_OPERAND (arg0, 1))));
4734 else if (TREE_CODE (arg0) == COND_EXPR)
4736 t = fold (build (COND_EXPR, type, TREE_OPERAND (arg0, 0),
4737 fold (build1 (code, type, TREE_OPERAND (arg0, 1))),
4738 fold (build1 (code, type, TREE_OPERAND (arg0, 2)))));
4740 /* If this was a conversion, and all we did was to move into
4741 inside the COND_EXPR, bring it back out. But leave it if
4742 it is a conversion from integer to integer and the
4743 result precision is no wider than a word since such a
4744 conversion is cheap and may be optimized away by combine,
4745 while it couldn't if it were outside the COND_EXPR. Then return
4746 so we don't get into an infinite recursion loop taking the
4747 conversion out and then back in. */
4749 if ((code == NOP_EXPR || code == CONVERT_EXPR
4750 || code == NON_LVALUE_EXPR)
4751 && TREE_CODE (t) == COND_EXPR
4752 && TREE_CODE (TREE_OPERAND (t, 1)) == code
4753 && TREE_CODE (TREE_OPERAND (t, 2)) == code
4754 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))
4755 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 2), 0)))
4756 && ! (INTEGRAL_TYPE_P (TREE_TYPE (t))
4757 && INTEGRAL_TYPE_P (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0)))
4758 && TYPE_PRECISION (TREE_TYPE (t)) <= BITS_PER_WORD))
4759 t = build1 (code, type,
4761 TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0)),
4762 TREE_OPERAND (t, 0),
4763 TREE_OPERAND (TREE_OPERAND (t, 1), 0),
4764 TREE_OPERAND (TREE_OPERAND (t, 2), 0)));
4767 else if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<')
4768 return fold (build (COND_EXPR, type, arg0,
4769 fold (build1 (code, type, integer_one_node)),
4770 fold (build1 (code, type, integer_zero_node))));
4772 else if (TREE_CODE_CLASS (code) == '2'
4773 || TREE_CODE_CLASS (code) == '<')
4775 if (TREE_CODE (arg1) == COMPOUND_EXPR)
4776 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
4777 fold (build (code, type,
4778 arg0, TREE_OPERAND (arg1, 1))));
4779 else if ((TREE_CODE (arg1) == COND_EXPR
4780 || (TREE_CODE_CLASS (TREE_CODE (arg1)) == '<'
4781 && TREE_CODE_CLASS (code) != '<'))
4782 && (TREE_CODE (arg0) != COND_EXPR
4783 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
4784 && (! TREE_SIDE_EFFECTS (arg0)
4785 || (global_bindings_p () == 0
4786 && ! contains_placeholder_p (arg0))))
4788 tree test, true_value, false_value;
4789 tree lhs = 0, rhs = 0;
4791 if (TREE_CODE (arg1) == COND_EXPR)
4793 test = TREE_OPERAND (arg1, 0);
4794 true_value = TREE_OPERAND (arg1, 1);
4795 false_value = TREE_OPERAND (arg1, 2);
4799 tree testtype = TREE_TYPE (arg1);
4801 true_value = convert (testtype, integer_one_node);
4802 false_value = convert (testtype, integer_zero_node);
4805 /* If ARG0 is complex we want to make sure we only evaluate
4806 it once. Though this is only required if it is volatile, it
4807 might be more efficient even if it is not. However, if we
4808 succeed in folding one part to a constant, we do not need
4809 to make this SAVE_EXPR. Since we do this optimization
4810 primarily to see if we do end up with constant and this
4811 SAVE_EXPR interferes with later optimizations, suppressing
4812 it when we can is important.
4814 If we are not in a function, we can't make a SAVE_EXPR, so don't
4815 try to do so. Don't try to see if the result is a constant
4816 if an arm is a COND_EXPR since we get exponential behavior
4819 if (TREE_CODE (arg0) != SAVE_EXPR && ! TREE_CONSTANT (arg0)
4820 && global_bindings_p () == 0
4821 && ((TREE_CODE (arg0) != VAR_DECL
4822 && TREE_CODE (arg0) != PARM_DECL)
4823 || TREE_SIDE_EFFECTS (arg0)))
4825 if (TREE_CODE (true_value) != COND_EXPR)
4826 lhs = fold (build (code, type, arg0, true_value));
4828 if (TREE_CODE (false_value) != COND_EXPR)
4829 rhs = fold (build (code, type, arg0, false_value));
4831 if ((lhs == 0 || ! TREE_CONSTANT (lhs))
4832 && (rhs == 0 || !TREE_CONSTANT (rhs)))
4833 arg0 = save_expr (arg0), lhs = rhs = 0;
4837 lhs = fold (build (code, type, arg0, true_value));
4839 rhs = fold (build (code, type, arg0, false_value));
4841 test = fold (build (COND_EXPR, type, test, lhs, rhs));
4843 if (TREE_CODE (arg0) == SAVE_EXPR)
4844 return build (COMPOUND_EXPR, type,
4845 convert (void_type_node, arg0),
4846 strip_compound_expr (test, arg0));
4848 return convert (type, test);
4851 else if (TREE_CODE (arg0) == COMPOUND_EXPR)
4852 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
4853 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
4854 else if ((TREE_CODE (arg0) == COND_EXPR
4855 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
4856 && TREE_CODE_CLASS (code) != '<'))
4857 && (TREE_CODE (arg1) != COND_EXPR
4858 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
4859 && (! TREE_SIDE_EFFECTS (arg1)
4860 || (global_bindings_p () == 0
4861 && ! contains_placeholder_p (arg1))))
4863 tree test, true_value, false_value;
4864 tree lhs = 0, rhs = 0;
4866 if (TREE_CODE (arg0) == COND_EXPR)
4868 test = TREE_OPERAND (arg0, 0);
4869 true_value = TREE_OPERAND (arg0, 1);
4870 false_value = TREE_OPERAND (arg0, 2);
4874 tree testtype = TREE_TYPE (arg0);
4876 true_value = convert (testtype, integer_one_node);
4877 false_value = convert (testtype, integer_zero_node);
4880 if (TREE_CODE (arg1) != SAVE_EXPR && ! TREE_CONSTANT (arg0)
4881 && global_bindings_p () == 0
4882 && ((TREE_CODE (arg1) != VAR_DECL
4883 && TREE_CODE (arg1) != PARM_DECL)
4884 || TREE_SIDE_EFFECTS (arg1)))
4886 if (TREE_CODE (true_value) != COND_EXPR)
4887 lhs = fold (build (code, type, true_value, arg1));
4889 if (TREE_CODE (false_value) != COND_EXPR)
4890 rhs = fold (build (code, type, false_value, arg1));
4892 if ((lhs == 0 || ! TREE_CONSTANT (lhs))
4893 && (rhs == 0 || !TREE_CONSTANT (rhs)))
4894 arg1 = save_expr (arg1), lhs = rhs = 0;
4898 lhs = fold (build (code, type, true_value, arg1));
4901 rhs = fold (build (code, type, false_value, arg1));
4903 test = fold (build (COND_EXPR, type, test, lhs, rhs));
4904 if (TREE_CODE (arg1) == SAVE_EXPR)
4905 return build (COMPOUND_EXPR, type,
4906 convert (void_type_node, arg1),
4907 strip_compound_expr (test, arg1));
4909 return convert (type, test);
4912 else if (TREE_CODE_CLASS (code) == '<'
4913 && TREE_CODE (arg0) == COMPOUND_EXPR)
4914 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
4915 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
4916 else if (TREE_CODE_CLASS (code) == '<'
4917 && TREE_CODE (arg1) == COMPOUND_EXPR)
4918 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
4919 fold (build (code, type, arg0, TREE_OPERAND (arg1, 1))));
4931 return fold (DECL_INITIAL (t));
4936 case FIX_TRUNC_EXPR:
4937 /* Other kinds of FIX are not handled properly by fold_convert. */
4939 if (TREE_TYPE (TREE_OPERAND (t, 0)) == TREE_TYPE (t))
4940 return TREE_OPERAND (t, 0);
4942 /* Handle cases of two conversions in a row. */
4943 if (TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
4944 || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR)
4946 tree inside_type = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
4947 tree inter_type = TREE_TYPE (TREE_OPERAND (t, 0));
4948 tree final_type = TREE_TYPE (t);
4949 int inside_int = INTEGRAL_TYPE_P (inside_type);
4950 int inside_ptr = POINTER_TYPE_P (inside_type);
4951 int inside_float = FLOAT_TYPE_P (inside_type);
4952 int inside_prec = TYPE_PRECISION (inside_type);
4953 int inside_unsignedp = TREE_UNSIGNED (inside_type);
4954 int inter_int = INTEGRAL_TYPE_P (inter_type);
4955 int inter_ptr = POINTER_TYPE_P (inter_type);
4956 int inter_float = FLOAT_TYPE_P (inter_type);
4957 int inter_prec = TYPE_PRECISION (inter_type);
4958 int inter_unsignedp = TREE_UNSIGNED (inter_type);
4959 int final_int = INTEGRAL_TYPE_P (final_type);
4960 int final_ptr = POINTER_TYPE_P (final_type);
4961 int final_float = FLOAT_TYPE_P (final_type);
4962 int final_prec = TYPE_PRECISION (final_type);
4963 int final_unsignedp = TREE_UNSIGNED (final_type);
4965 /* In addition to the cases of two conversions in a row
4966 handled below, if we are converting something to its own
4967 type via an object of identical or wider precision, neither
4968 conversion is needed. */
4969 if (inside_type == final_type
4970 && ((inter_int && final_int) || (inter_float && final_float))
4971 && inter_prec >= final_prec)
4972 return TREE_OPERAND (TREE_OPERAND (t, 0), 0);
4974 /* Likewise, if the intermediate and final types are either both
4975 float or both integer, we don't need the middle conversion if
4976 it is wider than the final type and doesn't change the signedness
4977 (for integers). Avoid this if the final type is a pointer
4978 since then we sometimes need the inner conversion. Likewise if
4979 the outer has a precision not equal to the size of its mode. */
4980 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
4981 || (inter_float && inside_float))
4982 && inter_prec >= inside_prec
4983 && (inter_float || inter_unsignedp == inside_unsignedp)
4984 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
4985 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
4987 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
4989 /* If we have a sign-extension of a zero-extended value, we can
4990 replace that by a single zero-extension. */
4991 if (inside_int && inter_int && final_int
4992 && inside_prec < inter_prec && inter_prec < final_prec
4993 && inside_unsignedp && !inter_unsignedp)
4994 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
4996 /* Two conversions in a row are not needed unless:
4997 - some conversion is floating-point (overstrict for now), or
4998 - the intermediate type is narrower than both initial and
5000 - the intermediate type and innermost type differ in signedness,
5001 and the outermost type is wider than the intermediate, or
5002 - the initial type is a pointer type and the precisions of the
5003 intermediate and final types differ, or
5004 - the final type is a pointer type and the precisions of the
5005 initial and intermediate types differ. */
5006 if (! inside_float && ! inter_float && ! final_float
5007 && (inter_prec > inside_prec || inter_prec > final_prec)
5008 && ! (inside_int && inter_int
5009 && inter_unsignedp != inside_unsignedp
5010 && inter_prec < final_prec)
5011 && ((inter_unsignedp && inter_prec > inside_prec)
5012 == (final_unsignedp && final_prec > inter_prec))
5013 && ! (inside_ptr && inter_prec != final_prec)
5014 && ! (final_ptr && inside_prec != inter_prec)
5015 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
5016 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
5018 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5021 if (TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR
5022 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t, 0), 1))
5023 /* Detect assigning a bitfield. */
5024 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) == COMPONENT_REF
5025 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 1))))
5027 /* Don't leave an assignment inside a conversion
5028 unless assigning a bitfield. */
5029 tree prev = TREE_OPERAND (t, 0);
5030 TREE_OPERAND (t, 0) = TREE_OPERAND (prev, 1);
5031 /* First do the assignment, then return converted constant. */
5032 t = build (COMPOUND_EXPR, TREE_TYPE (t), prev, fold (t));
5038 TREE_CONSTANT (t) = TREE_CONSTANT (arg0);
5041 return fold_convert (t, arg0);
5043 #if 0 /* This loses on &"foo"[0]. */
5048 /* Fold an expression like: "foo"[2] */
5049 if (TREE_CODE (arg0) == STRING_CST
5050 && TREE_CODE (arg1) == INTEGER_CST
5051 && !TREE_INT_CST_HIGH (arg1)
5052 && (i = TREE_INT_CST_LOW (arg1)) < TREE_STRING_LENGTH (arg0))
5054 t = build_int_2 (TREE_STRING_POINTER (arg0)[i], 0);
5055 TREE_TYPE (t) = TREE_TYPE (TREE_TYPE (arg0));
5056 force_fit_type (t, 0);
5063 if (TREE_CODE (arg0) == CONSTRUCTOR)
5065 tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0));
5072 TREE_CONSTANT (t) = wins;
5078 if (TREE_CODE (arg0) == INTEGER_CST)
5080 HOST_WIDE_INT low, high;
5081 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
5082 TREE_INT_CST_HIGH (arg0),
5084 t = build_int_2 (low, high);
5085 TREE_TYPE (t) = type;
5087 = (TREE_OVERFLOW (arg0)
5088 | force_fit_type (t, overflow && !TREE_UNSIGNED (type)));
5089 TREE_CONSTANT_OVERFLOW (t)
5090 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
5092 else if (TREE_CODE (arg0) == REAL_CST)
5093 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
5095 else if (TREE_CODE (arg0) == NEGATE_EXPR)
5096 return TREE_OPERAND (arg0, 0);
5098 /* Convert - (a - b) to (b - a) for non-floating-point. */
5099 else if (TREE_CODE (arg0) == MINUS_EXPR
5100 && (! FLOAT_TYPE_P (type) || flag_fast_math))
5101 return build (MINUS_EXPR, type, TREE_OPERAND (arg0, 1),
5102 TREE_OPERAND (arg0, 0));
5109 if (TREE_CODE (arg0) == INTEGER_CST)
5111 if (! TREE_UNSIGNED (type)
5112 && TREE_INT_CST_HIGH (arg0) < 0)
5114 HOST_WIDE_INT low, high;
5115 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
5116 TREE_INT_CST_HIGH (arg0),
5118 t = build_int_2 (low, high);
5119 TREE_TYPE (t) = type;
5121 = (TREE_OVERFLOW (arg0)
5122 | force_fit_type (t, overflow));
5123 TREE_CONSTANT_OVERFLOW (t)
5124 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
5127 else if (TREE_CODE (arg0) == REAL_CST)
5129 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
5130 t = build_real (type,
5131 REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
5134 else if (TREE_CODE (arg0) == ABS_EXPR || TREE_CODE (arg0) == NEGATE_EXPR)
5135 return build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0));
5139 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
5141 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
5142 return build (COMPLEX_EXPR, TREE_TYPE (arg0),
5143 TREE_OPERAND (arg0, 0),
5144 negate_expr (TREE_OPERAND (arg0, 1)));
5145 else if (TREE_CODE (arg0) == COMPLEX_CST)
5146 return build_complex (type, TREE_OPERAND (arg0, 0),
5147 negate_expr (TREE_OPERAND (arg0, 1)));
5148 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
5149 return fold (build (TREE_CODE (arg0), type,
5150 fold (build1 (CONJ_EXPR, type,
5151 TREE_OPERAND (arg0, 0))),
5152 fold (build1 (CONJ_EXPR,
5153 type, TREE_OPERAND (arg0, 1)))));
5154 else if (TREE_CODE (arg0) == CONJ_EXPR)
5155 return TREE_OPERAND (arg0, 0);
5161 t = build_int_2 (~ TREE_INT_CST_LOW (arg0),
5162 ~ TREE_INT_CST_HIGH (arg0));
5163 TREE_TYPE (t) = type;
5164 force_fit_type (t, 0);
5165 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg0);
5166 TREE_CONSTANT_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (arg0);
5168 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
5169 return TREE_OPERAND (arg0, 0);
5173 /* A + (-B) -> A - B */
5174 if (TREE_CODE (arg1) == NEGATE_EXPR)
5175 return fold (build (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5176 /* (-A) + B -> B - A */
5177 if (TREE_CODE (arg0) == NEGATE_EXPR)
5178 return fold (build (MINUS_EXPR, type, arg1, TREE_OPERAND (arg0, 0)));
5179 else if (! FLOAT_TYPE_P (type))
5181 if (integer_zerop (arg1))
5182 return non_lvalue (convert (type, arg0));
5184 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
5185 with a constant, and the two constants have no bits in common,
5186 we should treat this as a BIT_IOR_EXPR since this may produce more
5188 if (TREE_CODE (arg0) == BIT_AND_EXPR
5189 && TREE_CODE (arg1) == BIT_AND_EXPR
5190 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5191 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
5192 && integer_zerop (const_binop (BIT_AND_EXPR,
5193 TREE_OPERAND (arg0, 1),
5194 TREE_OPERAND (arg1, 1), 0)))
5196 code = BIT_IOR_EXPR;
5200 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
5201 (plus (plus (mult) (mult)) (foo)) so that we can
5202 take advantage of the factoring cases below. */
5203 if ((TREE_CODE (arg0) == PLUS_EXPR
5204 && TREE_CODE (arg1) == MULT_EXPR)
5205 || (TREE_CODE (arg1) == PLUS_EXPR
5206 && TREE_CODE (arg0) == MULT_EXPR))
5208 tree parg0, parg1, parg, marg;
5210 if (TREE_CODE (arg0) == PLUS_EXPR)
5211 parg = arg0, marg = arg1;
5213 parg = arg1, marg = arg0;
5214 parg0 = TREE_OPERAND (parg, 0);
5215 parg1 = TREE_OPERAND (parg, 1);
5219 if (TREE_CODE (parg0) == MULT_EXPR
5220 && TREE_CODE (parg1) != MULT_EXPR)
5221 return fold (build (PLUS_EXPR, type,
5222 fold (build (PLUS_EXPR, type, parg0, marg)),
5224 if (TREE_CODE (parg0) != MULT_EXPR
5225 && TREE_CODE (parg1) == MULT_EXPR)
5226 return fold (build (PLUS_EXPR, type,
5227 fold (build (PLUS_EXPR, type, parg1, marg)),
5231 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR)
5233 tree arg00, arg01, arg10, arg11;
5234 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
5236 /* (A * C) + (B * C) -> (A+B) * C.
5237 We are most concerned about the case where C is a constant,
5238 but other combinations show up during loop reduction. Since
5239 it is not difficult, try all four possibilities. */
5241 arg00 = TREE_OPERAND (arg0, 0);
5242 arg01 = TREE_OPERAND (arg0, 1);
5243 arg10 = TREE_OPERAND (arg1, 0);
5244 arg11 = TREE_OPERAND (arg1, 1);
5247 if (operand_equal_p (arg01, arg11, 0))
5248 same = arg01, alt0 = arg00, alt1 = arg10;
5249 else if (operand_equal_p (arg00, arg10, 0))
5250 same = arg00, alt0 = arg01, alt1 = arg11;
5251 else if (operand_equal_p (arg00, arg11, 0))
5252 same = arg00, alt0 = arg01, alt1 = arg10;
5253 else if (operand_equal_p (arg01, arg10, 0))
5254 same = arg01, alt0 = arg00, alt1 = arg11;
5256 /* No identical multiplicands; see if we can find a common
5257 power-of-two factor in non-power-of-two multiplies. This
5258 can help in multi-dimensional array access. */
5259 else if (TREE_CODE (arg01) == INTEGER_CST
5260 && TREE_CODE (arg11) == INTEGER_CST
5261 && TREE_INT_CST_HIGH (arg01) == 0
5262 && TREE_INT_CST_HIGH (arg11) == 0)
5264 HOST_WIDE_INT int01, int11, tmp;
5265 int01 = TREE_INT_CST_LOW (arg01);
5266 int11 = TREE_INT_CST_LOW (arg11);
5268 /* Move min of absolute values to int11. */
5269 if ((int01 >= 0 ? int01 : -int01)
5270 < (int11 >= 0 ? int11 : -int11))
5272 tmp = int01, int01 = int11, int11 = tmp;
5273 alt0 = arg00, arg00 = arg10, arg10 = alt0;
5274 alt0 = arg01, arg01 = arg11, arg11 = alt0;
5277 if (exact_log2 (int11) > 0 && int01 % int11 == 0)
5279 alt0 = fold (build (MULT_EXPR, type, arg00,
5280 build_int_2 (int01 / int11, 0)));
5287 return fold (build (MULT_EXPR, type,
5288 fold (build (PLUS_EXPR, type, alt0, alt1)),
5292 /* In IEEE floating point, x+0 may not equal x. */
5293 else if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
5295 && real_zerop (arg1))
5296 return non_lvalue (convert (type, arg0));
5297 /* x+(-0) equals x, even for IEEE. */
5298 else if (TREE_CODE (arg1) == REAL_CST
5299 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (arg1)))
5300 return non_lvalue (convert (type, arg0));
5303 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
5304 is a rotate of A by C1 bits. */
5305 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
5306 is a rotate of A by B bits. */
5308 register enum tree_code code0, code1;
5309 code0 = TREE_CODE (arg0);
5310 code1 = TREE_CODE (arg1);
5311 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
5312 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
5313 && operand_equal_p (TREE_OPERAND (arg0, 0),
5314 TREE_OPERAND (arg1,0), 0)
5315 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5317 register tree tree01, tree11;
5318 register enum tree_code code01, code11;
5320 tree01 = TREE_OPERAND (arg0, 1);
5321 tree11 = TREE_OPERAND (arg1, 1);
5322 STRIP_NOPS (tree01);
5323 STRIP_NOPS (tree11);
5324 code01 = TREE_CODE (tree01);
5325 code11 = TREE_CODE (tree11);
5326 if (code01 == INTEGER_CST
5327 && code11 == INTEGER_CST
5328 && TREE_INT_CST_HIGH (tree01) == 0
5329 && TREE_INT_CST_HIGH (tree11) == 0
5330 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
5331 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
5332 return build (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
5333 code0 == LSHIFT_EXPR ? tree01 : tree11);
5334 else if (code11 == MINUS_EXPR)
5336 tree tree110, tree111;
5337 tree110 = TREE_OPERAND (tree11, 0);
5338 tree111 = TREE_OPERAND (tree11, 1);
5339 STRIP_NOPS (tree110);
5340 STRIP_NOPS (tree111);
5341 if (TREE_CODE (tree110) == INTEGER_CST
5342 && TREE_INT_CST_HIGH (tree110) == 0
5343 && (TREE_INT_CST_LOW (tree110)
5344 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5345 && operand_equal_p (tree01, tree111, 0))
5346 return build ((code0 == LSHIFT_EXPR
5349 type, TREE_OPERAND (arg0, 0), tree01);
5351 else if (code01 == MINUS_EXPR)
5353 tree tree010, tree011;
5354 tree010 = TREE_OPERAND (tree01, 0);
5355 tree011 = TREE_OPERAND (tree01, 1);
5356 STRIP_NOPS (tree010);
5357 STRIP_NOPS (tree011);
5358 if (TREE_CODE (tree010) == INTEGER_CST
5359 && TREE_INT_CST_HIGH (tree010) == 0
5360 && (TREE_INT_CST_LOW (tree010)
5361 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5362 && operand_equal_p (tree11, tree011, 0))
5363 return build ((code0 != LSHIFT_EXPR
5366 type, TREE_OPERAND (arg0, 0), tree11);
5373 /* In most languages, can't associate operations on floats through
5374 parentheses. Rather than remember where the parentheses were, we
5375 don't associate floats at all. It shouldn't matter much. However,
5376 associating multiplications is only very slightly inaccurate, so do
5377 that if -ffast-math is specified. */
5380 && (! FLOAT_TYPE_P (type)
5381 || (flag_fast_math && code != MULT_EXPR)))
5383 tree var0, con0, lit0, var1, con1, lit1;
5385 /* Split both trees into variables, constants, and literals. Then
5386 associate each group together, the constants with literals,
5387 then the result with variables. This increases the chances of
5388 literals being recombined later and of generating relocatable
5389 expressions for the sum of a constant and literal. */
5390 var0 = split_tree (arg0, code, &con0, &lit0, 0);
5391 var1 = split_tree (arg1, code, &con1, &lit1, code == MINUS_EXPR);
5393 /* Only do something if we found more than two objects. Otherwise,
5394 nothing has changed and we risk infinite recursion. */
5395 if (2 < ((var0 != 0) + (var1 != 0) + (con0 != 0) + (con1 != 0)
5396 + (lit0 != 0) + (lit1 != 0)))
5398 var0 = associate_trees (var0, var1, code, type);
5399 con0 = associate_trees (con0, con1, code, type);
5400 lit0 = associate_trees (lit0, lit1, code, type);
5401 con0 = associate_trees (con0, lit0, code, type);
5402 return convert (type, associate_trees (var0, con0, code, type));
5407 #if defined (REAL_IS_NOT_DOUBLE) && ! defined (REAL_ARITHMETIC)
5408 if (TREE_CODE (arg1) == REAL_CST)
5410 #endif /* REAL_IS_NOT_DOUBLE, and no REAL_ARITHMETIC */
5412 t1 = const_binop (code, arg0, arg1, 0);
5413 if (t1 != NULL_TREE)
5415 /* The return value should always have
5416 the same type as the original expression. */
5417 if (TREE_TYPE (t1) != TREE_TYPE (t))
5418 t1 = convert (TREE_TYPE (t), t1);
5425 /* A - (-B) -> A + B */
5426 if (TREE_CODE (arg1) == NEGATE_EXPR)
5427 return fold (build (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5428 /* (-A) - CST -> (-CST) - A for floating point (what about ints ?) */
5429 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == REAL_CST)
5431 fold (build (MINUS_EXPR, type,
5432 build_real (TREE_TYPE (arg1),
5433 REAL_VALUE_NEGATE (TREE_REAL_CST (arg1))),
5434 TREE_OPERAND (arg0, 0)));
5436 if (! FLOAT_TYPE_P (type))
5438 if (! wins && integer_zerop (arg0))
5439 return negate_expr (arg1);
5440 if (integer_zerop (arg1))
5441 return non_lvalue (convert (type, arg0));
5443 /* (A * C) - (B * C) -> (A-B) * C. Since we are most concerned
5444 about the case where C is a constant, just try one of the
5445 four possibilities. */
5447 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR
5448 && operand_equal_p (TREE_OPERAND (arg0, 1),
5449 TREE_OPERAND (arg1, 1), 0))
5450 return fold (build (MULT_EXPR, type,
5451 fold (build (MINUS_EXPR, type,
5452 TREE_OPERAND (arg0, 0),
5453 TREE_OPERAND (arg1, 0))),
5454 TREE_OPERAND (arg0, 1)));
5457 else if (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
5460 /* Except with IEEE floating point, 0-x equals -x. */
5461 if (! wins && real_zerop (arg0))
5462 return negate_expr (arg1);
5463 /* Except with IEEE floating point, x-0 equals x. */
5464 if (real_zerop (arg1))
5465 return non_lvalue (convert (type, arg0));
5468 /* Fold &x - &x. This can happen from &x.foo - &x.
5469 This is unsafe for certain floats even in non-IEEE formats.
5470 In IEEE, it is unsafe because it does wrong for NaNs.
5471 Also note that operand_equal_p is always false if an operand
5474 if ((! FLOAT_TYPE_P (type) || flag_fast_math)
5475 && operand_equal_p (arg0, arg1, 0))
5476 return convert (type, integer_zero_node);
5481 /* (-A) * (-B) -> A * B */
5482 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR)
5483 return fold (build (MULT_EXPR, type, TREE_OPERAND (arg0, 0),
5484 TREE_OPERAND (arg1, 0)));
5486 if (! FLOAT_TYPE_P (type))
5488 if (integer_zerop (arg1))
5489 return omit_one_operand (type, arg1, arg0);
5490 if (integer_onep (arg1))
5491 return non_lvalue (convert (type, arg0));
5493 /* (a * (1 << b)) is (a << b) */
5494 if (TREE_CODE (arg1) == LSHIFT_EXPR
5495 && integer_onep (TREE_OPERAND (arg1, 0)))
5496 return fold (build (LSHIFT_EXPR, type, arg0,
5497 TREE_OPERAND (arg1, 1)));
5498 if (TREE_CODE (arg0) == LSHIFT_EXPR
5499 && integer_onep (TREE_OPERAND (arg0, 0)))
5500 return fold (build (LSHIFT_EXPR, type, arg1,
5501 TREE_OPERAND (arg0, 1)));
5503 if (TREE_CODE (arg1) == INTEGER_CST
5504 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
5506 return convert (type, tem);
5511 /* x*0 is 0, except for IEEE floating point. */
5512 if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
5514 && real_zerop (arg1))
5515 return omit_one_operand (type, arg1, arg0);
5516 /* In IEEE floating point, x*1 is not equivalent to x for snans.
5517 However, ANSI says we can drop signals,
5518 so we can do this anyway. */
5519 if (real_onep (arg1))
5520 return non_lvalue (convert (type, arg0));
5522 if (! wins && real_twop (arg1) && global_bindings_p () == 0
5523 && ! contains_placeholder_p (arg0))
5525 tree arg = save_expr (arg0);
5526 return build (PLUS_EXPR, type, arg, arg);
5533 if (integer_all_onesp (arg1))
5534 return omit_one_operand (type, arg1, arg0);
5535 if (integer_zerop (arg1))
5536 return non_lvalue (convert (type, arg0));
5537 t1 = distribute_bit_expr (code, type, arg0, arg1);
5538 if (t1 != NULL_TREE)
5541 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
5543 This results in more efficient code for machines without a NAND
5544 instruction. Combine will canonicalize to the first form
5545 which will allow use of NAND instructions provided by the
5546 backend if they exist. */
5547 if (TREE_CODE (arg0) == BIT_NOT_EXPR
5548 && TREE_CODE (arg1) == BIT_NOT_EXPR)
5550 return fold (build1 (BIT_NOT_EXPR, type,
5551 build (BIT_AND_EXPR, type,
5552 TREE_OPERAND (arg0, 0),
5553 TREE_OPERAND (arg1, 0))));
5556 /* See if this can be simplified into a rotate first. If that
5557 is unsuccessful continue in the association code. */
5561 if (integer_zerop (arg1))
5562 return non_lvalue (convert (type, arg0));
5563 if (integer_all_onesp (arg1))
5564 return fold (build1 (BIT_NOT_EXPR, type, arg0));
5566 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
5567 with a constant, and the two constants have no bits in common,
5568 we should treat this as a BIT_IOR_EXPR since this may produce more
5570 if (TREE_CODE (arg0) == BIT_AND_EXPR
5571 && TREE_CODE (arg1) == BIT_AND_EXPR
5572 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5573 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
5574 && integer_zerop (const_binop (BIT_AND_EXPR,
5575 TREE_OPERAND (arg0, 1),
5576 TREE_OPERAND (arg1, 1), 0)))
5578 code = BIT_IOR_EXPR;
5582 /* See if this can be simplified into a rotate first. If that
5583 is unsuccessful continue in the association code. */
5588 if (integer_all_onesp (arg1))
5589 return non_lvalue (convert (type, arg0));
5590 if (integer_zerop (arg1))
5591 return omit_one_operand (type, arg1, arg0);
5592 t1 = distribute_bit_expr (code, type, arg0, arg1);
5593 if (t1 != NULL_TREE)
5595 /* Simplify ((int)c & 0x377) into (int)c, if c is unsigned char. */
5596 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == NOP_EXPR
5597 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg1, 0))))
5599 int prec = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg1, 0)));
5600 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
5601 && (~TREE_INT_CST_LOW (arg0)
5602 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
5603 return build1 (NOP_EXPR, type, TREE_OPERAND (arg1, 0));
5605 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
5606 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5608 int prec = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
5609 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
5610 && (~TREE_INT_CST_LOW (arg1)
5611 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
5612 return build1 (NOP_EXPR, type, TREE_OPERAND (arg0, 0));
5615 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
5617 This results in more efficient code for machines without a NOR
5618 instruction. Combine will canonicalize to the first form
5619 which will allow use of NOR instructions provided by the
5620 backend if they exist. */
5621 if (TREE_CODE (arg0) == BIT_NOT_EXPR
5622 && TREE_CODE (arg1) == BIT_NOT_EXPR)
5624 return fold (build1 (BIT_NOT_EXPR, type,
5625 build (BIT_IOR_EXPR, type,
5626 TREE_OPERAND (arg0, 0),
5627 TREE_OPERAND (arg1, 0))));
5632 case BIT_ANDTC_EXPR:
5633 if (integer_all_onesp (arg0))
5634 return non_lvalue (convert (type, arg1));
5635 if (integer_zerop (arg0))
5636 return omit_one_operand (type, arg0, arg1);
5637 if (TREE_CODE (arg1) == INTEGER_CST)
5639 arg1 = fold (build1 (BIT_NOT_EXPR, type, arg1));
5640 code = BIT_AND_EXPR;
5646 /* In most cases, do nothing with a divide by zero. */
5647 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
5648 #ifndef REAL_INFINITY
5649 if (TREE_CODE (arg1) == REAL_CST && real_zerop (arg1))
5652 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
5654 /* (-A) / (-B) -> A / B */
5655 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR)
5656 return fold (build (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
5657 TREE_OPERAND (arg1, 0)));
5659 /* In IEEE floating point, x/1 is not equivalent to x for snans.
5660 However, ANSI says we can drop signals, so we can do this anyway. */
5661 if (real_onep (arg1))
5662 return non_lvalue (convert (type, arg0));
5664 /* If ARG1 is a constant, we can convert this to a multiply by the
5665 reciprocal. This does not have the same rounding properties,
5666 so only do this if -ffast-math. We can actually always safely
5667 do it if ARG1 is a power of two, but it's hard to tell if it is
5668 or not in a portable manner. */
5669 if (TREE_CODE (arg1) == REAL_CST)
5672 && 0 != (tem = const_binop (code, build_real (type, dconst1),
5674 return fold (build (MULT_EXPR, type, arg0, tem));
5675 /* Find the reciprocal if optimizing and the result is exact. */
5679 r = TREE_REAL_CST (arg1);
5680 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
5682 tem = build_real (type, r);
5683 return fold (build (MULT_EXPR, type, arg0, tem));
5689 case TRUNC_DIV_EXPR:
5690 case ROUND_DIV_EXPR:
5691 case FLOOR_DIV_EXPR:
5693 case EXACT_DIV_EXPR:
5694 if (integer_onep (arg1))
5695 return non_lvalue (convert (type, arg0));
5696 if (integer_zerop (arg1))
5699 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
5700 operation, EXACT_DIV_EXPR.
5702 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
5703 At one time others generated faster code, it's not clear if they do
5704 after the last round to changes to the DIV code in expmed.c. */
5705 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
5706 && multiple_of_p (type, arg0, arg1))
5707 return fold (build (EXACT_DIV_EXPR, type, arg0, arg1));
5709 if (TREE_CODE (arg1) == INTEGER_CST
5710 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
5712 return convert (type, tem);
5717 case FLOOR_MOD_EXPR:
5718 case ROUND_MOD_EXPR:
5719 case TRUNC_MOD_EXPR:
5720 if (integer_onep (arg1))
5721 return omit_one_operand (type, integer_zero_node, arg0);
5722 if (integer_zerop (arg1))
5725 if (TREE_CODE (arg1) == INTEGER_CST
5726 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
5728 return convert (type, tem);
5736 if (integer_zerop (arg1))
5737 return non_lvalue (convert (type, arg0));
5738 /* Since negative shift count is not well-defined,
5739 don't try to compute it in the compiler. */
5740 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
5742 /* Rewrite an LROTATE_EXPR by a constant into an
5743 RROTATE_EXPR by a new constant. */
5744 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
5746 TREE_SET_CODE (t, RROTATE_EXPR);
5747 code = RROTATE_EXPR;
5748 TREE_OPERAND (t, 1) = arg1
5751 convert (TREE_TYPE (arg1),
5752 build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type)), 0)),
5754 if (tree_int_cst_sgn (arg1) < 0)
5758 /* If we have a rotate of a bit operation with the rotate count and
5759 the second operand of the bit operation both constant,
5760 permute the two operations. */
5761 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
5762 && (TREE_CODE (arg0) == BIT_AND_EXPR
5763 || TREE_CODE (arg0) == BIT_ANDTC_EXPR
5764 || TREE_CODE (arg0) == BIT_IOR_EXPR
5765 || TREE_CODE (arg0) == BIT_XOR_EXPR)
5766 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
5767 return fold (build (TREE_CODE (arg0), type,
5768 fold (build (code, type,
5769 TREE_OPERAND (arg0, 0), arg1)),
5770 fold (build (code, type,
5771 TREE_OPERAND (arg0, 1), arg1))));
5773 /* Two consecutive rotates adding up to the width of the mode can
5775 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
5776 && TREE_CODE (arg0) == RROTATE_EXPR
5777 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5778 && TREE_INT_CST_HIGH (arg1) == 0
5779 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
5780 && ((TREE_INT_CST_LOW (arg1)
5781 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
5782 == GET_MODE_BITSIZE (TYPE_MODE (type))))
5783 return TREE_OPERAND (arg0, 0);
5788 if (operand_equal_p (arg0, arg1, 0))
5790 if (INTEGRAL_TYPE_P (type)
5791 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), 1))
5792 return omit_one_operand (type, arg1, arg0);
5796 if (operand_equal_p (arg0, arg1, 0))
5798 if (INTEGRAL_TYPE_P (type)
5799 && TYPE_MAX_VALUE (type)
5800 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), 1))
5801 return omit_one_operand (type, arg1, arg0);
5804 case TRUTH_NOT_EXPR:
5805 /* Note that the operand of this must be an int
5806 and its values must be 0 or 1.
5807 ("true" is a fixed value perhaps depending on the language,
5808 but we don't handle values other than 1 correctly yet.) */
5809 tem = invert_truthvalue (arg0);
5810 /* Avoid infinite recursion. */
5811 if (TREE_CODE (tem) == TRUTH_NOT_EXPR)
5813 return convert (type, tem);
5815 case TRUTH_ANDIF_EXPR:
5816 /* Note that the operands of this must be ints
5817 and their values must be 0 or 1.
5818 ("true" is a fixed value perhaps depending on the language.) */
5819 /* If first arg is constant zero, return it. */
5820 if (integer_zerop (arg0))
5822 case TRUTH_AND_EXPR:
5823 /* If either arg is constant true, drop it. */
5824 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
5825 return non_lvalue (arg1);
5826 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
5827 return non_lvalue (arg0);
5828 /* If second arg is constant zero, result is zero, but first arg
5829 must be evaluated. */
5830 if (integer_zerop (arg1))
5831 return omit_one_operand (type, arg1, arg0);
5832 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
5833 case will be handled here. */
5834 if (integer_zerop (arg0))
5835 return omit_one_operand (type, arg0, arg1);
5838 /* We only do these simplifications if we are optimizing. */
5842 /* Check for things like (A || B) && (A || C). We can convert this
5843 to A || (B && C). Note that either operator can be any of the four
5844 truth and/or operations and the transformation will still be
5845 valid. Also note that we only care about order for the
5846 ANDIF and ORIF operators. If B contains side effects, this
5847 might change the truth-value of A. */
5848 if (TREE_CODE (arg0) == TREE_CODE (arg1)
5849 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
5850 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
5851 || TREE_CODE (arg0) == TRUTH_AND_EXPR
5852 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
5853 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
5855 tree a00 = TREE_OPERAND (arg0, 0);
5856 tree a01 = TREE_OPERAND (arg0, 1);
5857 tree a10 = TREE_OPERAND (arg1, 0);
5858 tree a11 = TREE_OPERAND (arg1, 1);
5859 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
5860 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
5861 && (code == TRUTH_AND_EXPR
5862 || code == TRUTH_OR_EXPR));
5864 if (operand_equal_p (a00, a10, 0))
5865 return fold (build (TREE_CODE (arg0), type, a00,
5866 fold (build (code, type, a01, a11))));
5867 else if (commutative && operand_equal_p (a00, a11, 0))
5868 return fold (build (TREE_CODE (arg0), type, a00,
5869 fold (build (code, type, a01, a10))));
5870 else if (commutative && operand_equal_p (a01, a10, 0))
5871 return fold (build (TREE_CODE (arg0), type, a01,
5872 fold (build (code, type, a00, a11))));
5874 /* This case if tricky because we must either have commutative
5875 operators or else A10 must not have side-effects. */
5877 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
5878 && operand_equal_p (a01, a11, 0))
5879 return fold (build (TREE_CODE (arg0), type,
5880 fold (build (code, type, a00, a10)),
5884 /* See if we can build a range comparison. */
5885 if (0 != (tem = fold_range_test (t)))
5888 /* Check for the possibility of merging component references. If our
5889 lhs is another similar operation, try to merge its rhs with our
5890 rhs. Then try to merge our lhs and rhs. */
5891 if (TREE_CODE (arg0) == code
5892 && 0 != (tem = fold_truthop (code, type,
5893 TREE_OPERAND (arg0, 1), arg1)))
5894 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
5896 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
5901 case TRUTH_ORIF_EXPR:
5902 /* Note that the operands of this must be ints
5903 and their values must be 0 or true.
5904 ("true" is a fixed value perhaps depending on the language.) */
5905 /* If first arg is constant true, return it. */
5906 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
5909 /* If either arg is constant zero, drop it. */
5910 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
5911 return non_lvalue (arg1);
5912 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1))
5913 return non_lvalue (arg0);
5914 /* If second arg is constant true, result is true, but we must
5915 evaluate first arg. */
5916 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
5917 return omit_one_operand (type, arg1, arg0);
5918 /* Likewise for first arg, but note this only occurs here for
5920 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
5921 return omit_one_operand (type, arg0, arg1);
5924 case TRUTH_XOR_EXPR:
5925 /* If either arg is constant zero, drop it. */
5926 if (integer_zerop (arg0))
5927 return non_lvalue (arg1);
5928 if (integer_zerop (arg1))
5929 return non_lvalue (arg0);
5930 /* If either arg is constant true, this is a logical inversion. */
5931 if (integer_onep (arg0))
5932 return non_lvalue (invert_truthvalue (arg1));
5933 if (integer_onep (arg1))
5934 return non_lvalue (invert_truthvalue (arg0));
5943 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
5945 /* (-a) CMP (-b) -> b CMP a */
5946 if (TREE_CODE (arg0) == NEGATE_EXPR
5947 && TREE_CODE (arg1) == NEGATE_EXPR)
5948 return fold (build (code, type, TREE_OPERAND (arg1, 0),
5949 TREE_OPERAND (arg0, 0)));
5950 /* (-a) CMP CST -> a swap(CMP) (-CST) */
5951 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == REAL_CST)
5954 (swap_tree_comparison (code), type,
5955 TREE_OPERAND (arg0, 0),
5956 build_real (TREE_TYPE (arg1),
5957 REAL_VALUE_NEGATE (TREE_REAL_CST (arg1)))));
5958 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
5959 /* a CMP (-0) -> a CMP 0 */
5960 if (TREE_CODE (arg1) == REAL_CST
5961 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (arg1)))
5962 return fold (build (code, type, arg0,
5963 build_real (TREE_TYPE (arg1), dconst0)));
5967 /* If one arg is a constant integer, put it last. */
5968 if (TREE_CODE (arg0) == INTEGER_CST
5969 && TREE_CODE (arg1) != INTEGER_CST)
5971 TREE_OPERAND (t, 0) = arg1;
5972 TREE_OPERAND (t, 1) = arg0;
5973 arg0 = TREE_OPERAND (t, 0);
5974 arg1 = TREE_OPERAND (t, 1);
5975 code = swap_tree_comparison (code);
5976 TREE_SET_CODE (t, code);
5979 /* Convert foo++ == CONST into ++foo == CONST + INCR.
5980 First, see if one arg is constant; find the constant arg
5981 and the other one. */
5983 tree constop = 0, varop = NULL_TREE;
5984 int constopnum = -1;
5986 if (TREE_CONSTANT (arg1))
5987 constopnum = 1, constop = arg1, varop = arg0;
5988 if (TREE_CONSTANT (arg0))
5989 constopnum = 0, constop = arg0, varop = arg1;
5991 if (constop && TREE_CODE (varop) == POSTINCREMENT_EXPR)
5993 /* This optimization is invalid for ordered comparisons
5994 if CONST+INCR overflows or if foo+incr might overflow.
5995 This optimization is invalid for floating point due to rounding.
5996 For pointer types we assume overflow doesn't happen. */
5997 if (POINTER_TYPE_P (TREE_TYPE (varop))
5998 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
5999 && (code == EQ_EXPR || code == NE_EXPR)))
6002 = fold (build (PLUS_EXPR, TREE_TYPE (varop),
6003 constop, TREE_OPERAND (varop, 1)));
6004 TREE_SET_CODE (varop, PREINCREMENT_EXPR);
6006 /* If VAROP is a reference to a bitfield, we must mask
6007 the constant by the width of the field. */
6008 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
6009 && DECL_BIT_FIELD(TREE_OPERAND
6010 (TREE_OPERAND (varop, 0), 1)))
6013 = TREE_INT_CST_LOW (DECL_SIZE
6015 (TREE_OPERAND (varop, 0), 1)));
6016 tree mask, unsigned_type;
6018 tree folded_compare;
6020 /* First check whether the comparison would come out
6021 always the same. If we don't do that we would
6022 change the meaning with the masking. */
6023 if (constopnum == 0)
6024 folded_compare = fold (build (code, type, constop,
6025 TREE_OPERAND (varop, 0)));
6027 folded_compare = fold (build (code, type,
6028 TREE_OPERAND (varop, 0),
6030 if (integer_zerop (folded_compare)
6031 || integer_onep (folded_compare))
6032 return omit_one_operand (type, folded_compare, varop);
6034 unsigned_type = type_for_size (size, 1);
6035 precision = TYPE_PRECISION (unsigned_type);
6036 mask = build_int_2 (~0, ~0);
6037 TREE_TYPE (mask) = unsigned_type;
6038 force_fit_type (mask, 0);
6039 mask = const_binop (RSHIFT_EXPR, mask,
6040 size_int (precision - size), 0);
6041 newconst = fold (build (BIT_AND_EXPR,
6042 TREE_TYPE (varop), newconst,
6043 convert (TREE_TYPE (varop),
6048 t = build (code, type, TREE_OPERAND (t, 0),
6049 TREE_OPERAND (t, 1));
6050 TREE_OPERAND (t, constopnum) = newconst;
6054 else if (constop && TREE_CODE (varop) == POSTDECREMENT_EXPR)
6056 if (POINTER_TYPE_P (TREE_TYPE (varop))
6057 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
6058 && (code == EQ_EXPR || code == NE_EXPR)))
6061 = fold (build (MINUS_EXPR, TREE_TYPE (varop),
6062 constop, TREE_OPERAND (varop, 1)));
6063 TREE_SET_CODE (varop, PREDECREMENT_EXPR);
6065 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
6066 && DECL_BIT_FIELD(TREE_OPERAND
6067 (TREE_OPERAND (varop, 0), 1)))
6070 = TREE_INT_CST_LOW (DECL_SIZE
6072 (TREE_OPERAND (varop, 0), 1)));
6073 tree mask, unsigned_type;
6075 tree folded_compare;
6077 if (constopnum == 0)
6078 folded_compare = fold (build (code, type, constop,
6079 TREE_OPERAND (varop, 0)));
6081 folded_compare = fold (build (code, type,
6082 TREE_OPERAND (varop, 0),
6084 if (integer_zerop (folded_compare)
6085 || integer_onep (folded_compare))
6086 return omit_one_operand (type, folded_compare, varop);
6088 unsigned_type = type_for_size (size, 1);
6089 precision = TYPE_PRECISION (unsigned_type);
6090 mask = build_int_2 (~0, ~0);
6091 TREE_TYPE (mask) = TREE_TYPE (varop);
6092 force_fit_type (mask, 0);
6093 mask = const_binop (RSHIFT_EXPR, mask,
6094 size_int (precision - size), 0);
6095 newconst = fold (build (BIT_AND_EXPR,
6096 TREE_TYPE (varop), newconst,
6097 convert (TREE_TYPE (varop),
6102 t = build (code, type, TREE_OPERAND (t, 0),
6103 TREE_OPERAND (t, 1));
6104 TREE_OPERAND (t, constopnum) = newconst;
6110 /* Change X >= CST to X > (CST - 1) if CST is positive. */
6111 if (TREE_CODE (arg1) == INTEGER_CST
6112 && TREE_CODE (arg0) != INTEGER_CST
6113 && tree_int_cst_sgn (arg1) > 0)
6115 switch (TREE_CODE (t))
6119 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6120 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6125 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6126 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6134 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
6135 a MINUS_EXPR of a constant, we can convert it into a comparison with
6136 a revised constant as long as no overflow occurs. */
6137 if ((code == EQ_EXPR || code == NE_EXPR)
6138 && TREE_CODE (arg1) == INTEGER_CST
6139 && (TREE_CODE (arg0) == PLUS_EXPR
6140 || TREE_CODE (arg0) == MINUS_EXPR)
6141 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6142 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
6143 ? MINUS_EXPR : PLUS_EXPR,
6144 arg1, TREE_OPERAND (arg0, 1), 0))
6145 && ! TREE_CONSTANT_OVERFLOW (tem))
6146 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6148 /* Similarly for a NEGATE_EXPR. */
6149 else if ((code == EQ_EXPR || code == NE_EXPR)
6150 && TREE_CODE (arg0) == NEGATE_EXPR
6151 && TREE_CODE (arg1) == INTEGER_CST
6152 && 0 != (tem = negate_expr (arg1))
6153 && TREE_CODE (tem) == INTEGER_CST
6154 && ! TREE_CONSTANT_OVERFLOW (tem))
6155 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6157 /* If we have X - Y == 0, we can convert that to X == Y and similarly
6158 for !=. Don't do this for ordered comparisons due to overflow. */
6159 else if ((code == NE_EXPR || code == EQ_EXPR)
6160 && integer_zerop (arg1) && TREE_CODE (arg0) == MINUS_EXPR)
6161 return fold (build (code, type,
6162 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1)));
6164 /* If we are widening one operand of an integer comparison,
6165 see if the other operand is similarly being widened. Perhaps we
6166 can do the comparison in the narrower type. */
6167 else if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
6168 && TREE_CODE (arg0) == NOP_EXPR
6169 && (tem = get_unwidened (arg0, NULL_TREE)) != arg0
6170 && (t1 = get_unwidened (arg1, TREE_TYPE (tem))) != 0
6171 && (TREE_TYPE (t1) == TREE_TYPE (tem)
6172 || (TREE_CODE (t1) == INTEGER_CST
6173 && int_fits_type_p (t1, TREE_TYPE (tem)))))
6174 return fold (build (code, type, tem, convert (TREE_TYPE (tem), t1)));
6176 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
6177 constant, we can simplify it. */
6178 else if (TREE_CODE (arg1) == INTEGER_CST
6179 && (TREE_CODE (arg0) == MIN_EXPR
6180 || TREE_CODE (arg0) == MAX_EXPR)
6181 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
6182 return optimize_minmax_comparison (t);
6184 /* If we are comparing an ABS_EXPR with a constant, we can
6185 convert all the cases into explicit comparisons, but they may
6186 well not be faster than doing the ABS and one comparison.
6187 But ABS (X) <= C is a range comparison, which becomes a subtraction
6188 and a comparison, and is probably faster. */
6189 else if (code == LE_EXPR && TREE_CODE (arg1) == INTEGER_CST
6190 && TREE_CODE (arg0) == ABS_EXPR
6191 && ! TREE_SIDE_EFFECTS (arg0)
6192 && (0 != (tem = negate_expr (arg1)))
6193 && TREE_CODE (tem) == INTEGER_CST
6194 && ! TREE_CONSTANT_OVERFLOW (tem))
6195 return fold (build (TRUTH_ANDIF_EXPR, type,
6196 build (GE_EXPR, type, TREE_OPERAND (arg0, 0), tem),
6197 build (LE_EXPR, type,
6198 TREE_OPERAND (arg0, 0), arg1)));
6200 /* If this is an EQ or NE comparison with zero and ARG0 is
6201 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
6202 two operations, but the latter can be done in one less insn
6203 on machines that have only two-operand insns or on which a
6204 constant cannot be the first operand. */
6205 if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR)
6206 && TREE_CODE (arg0) == BIT_AND_EXPR)
6208 if (TREE_CODE (TREE_OPERAND (arg0, 0)) == LSHIFT_EXPR
6209 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 0), 0)))
6211 fold (build (code, type,
6212 build (BIT_AND_EXPR, TREE_TYPE (arg0),
6214 TREE_TYPE (TREE_OPERAND (arg0, 0)),
6215 TREE_OPERAND (arg0, 1),
6216 TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)),
6217 convert (TREE_TYPE (arg0),
6220 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
6221 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
6223 fold (build (code, type,
6224 build (BIT_AND_EXPR, TREE_TYPE (arg0),
6226 TREE_TYPE (TREE_OPERAND (arg0, 1)),
6227 TREE_OPERAND (arg0, 0),
6228 TREE_OPERAND (TREE_OPERAND (arg0, 1), 1)),
6229 convert (TREE_TYPE (arg0),
6234 /* If this is an NE or EQ comparison of zero against the result of a
6235 signed MOD operation whose second operand is a power of 2, make
6236 the MOD operation unsigned since it is simpler and equivalent. */
6237 if ((code == NE_EXPR || code == EQ_EXPR)
6238 && integer_zerop (arg1)
6239 && ! TREE_UNSIGNED (TREE_TYPE (arg0))
6240 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
6241 || TREE_CODE (arg0) == CEIL_MOD_EXPR
6242 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
6243 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
6244 && integer_pow2p (TREE_OPERAND (arg0, 1)))
6246 tree newtype = unsigned_type (TREE_TYPE (arg0));
6247 tree newmod = build (TREE_CODE (arg0), newtype,
6248 convert (newtype, TREE_OPERAND (arg0, 0)),
6249 convert (newtype, TREE_OPERAND (arg0, 1)));
6251 return build (code, type, newmod, convert (newtype, arg1));
6254 /* If this is an NE comparison of zero with an AND of one, remove the
6255 comparison since the AND will give the correct value. */
6256 if (code == NE_EXPR && integer_zerop (arg1)
6257 && TREE_CODE (arg0) == BIT_AND_EXPR
6258 && integer_onep (TREE_OPERAND (arg0, 1)))
6259 return convert (type, arg0);
6261 /* If we have (A & C) == C where C is a power of 2, convert this into
6262 (A & C) != 0. Similarly for NE_EXPR. */
6263 if ((code == EQ_EXPR || code == NE_EXPR)
6264 && TREE_CODE (arg0) == BIT_AND_EXPR
6265 && integer_pow2p (TREE_OPERAND (arg0, 1))
6266 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
6267 return build (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
6268 arg0, integer_zero_node);
6270 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
6271 and similarly for >= into !=. */
6272 if ((code == LT_EXPR || code == GE_EXPR)
6273 && TREE_UNSIGNED (TREE_TYPE (arg0))
6274 && TREE_CODE (arg1) == LSHIFT_EXPR
6275 && integer_onep (TREE_OPERAND (arg1, 0)))
6276 return build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
6277 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
6278 TREE_OPERAND (arg1, 1)),
6279 convert (TREE_TYPE (arg0), integer_zero_node));
6281 else if ((code == LT_EXPR || code == GE_EXPR)
6282 && TREE_UNSIGNED (TREE_TYPE (arg0))
6283 && (TREE_CODE (arg1) == NOP_EXPR
6284 || TREE_CODE (arg1) == CONVERT_EXPR)
6285 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
6286 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
6288 build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
6289 convert (TREE_TYPE (arg0),
6290 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
6291 TREE_OPERAND (TREE_OPERAND (arg1, 0), 1))),
6292 convert (TREE_TYPE (arg0), integer_zero_node));
6294 /* Simplify comparison of something with itself. (For IEEE
6295 floating-point, we can only do some of these simplifications.) */
6296 if (operand_equal_p (arg0, arg1, 0))
6303 if (INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
6304 return constant_boolean_node (1, type);
6306 TREE_SET_CODE (t, code);
6310 /* For NE, we can only do this simplification if integer. */
6311 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
6313 /* ... fall through ... */
6316 return constant_boolean_node (0, type);
6322 /* An unsigned comparison against 0 can be simplified. */
6323 if (integer_zerop (arg1)
6324 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
6325 || POINTER_TYPE_P (TREE_TYPE (arg1)))
6326 && TREE_UNSIGNED (TREE_TYPE (arg1)))
6328 switch (TREE_CODE (t))
6332 TREE_SET_CODE (t, NE_EXPR);
6336 TREE_SET_CODE (t, EQ_EXPR);
6339 return omit_one_operand (type,
6340 convert (type, integer_one_node),
6343 return omit_one_operand (type,
6344 convert (type, integer_zero_node),
6351 /* Comparisons with the highest or lowest possible integer of
6352 the specified size will have known values and an unsigned
6353 <= 0x7fffffff can be simplified. */
6355 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1)));
6357 if (TREE_CODE (arg1) == INTEGER_CST
6358 && ! TREE_CONSTANT_OVERFLOW (arg1)
6359 && width <= HOST_BITS_PER_WIDE_INT
6360 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
6361 || POINTER_TYPE_P (TREE_TYPE (arg1))))
6363 if (TREE_INT_CST_HIGH (arg1) == 0
6364 && (TREE_INT_CST_LOW (arg1)
6365 == ((HOST_WIDE_INT) 1 << (width - 1)) - 1)
6366 && ! TREE_UNSIGNED (TREE_TYPE (arg1)))
6367 switch (TREE_CODE (t))
6370 return omit_one_operand (type,
6371 convert (type, integer_zero_node),
6374 TREE_SET_CODE (t, EQ_EXPR);
6378 return omit_one_operand (type,
6379 convert (type, integer_one_node),
6382 TREE_SET_CODE (t, NE_EXPR);
6389 else if (TREE_INT_CST_HIGH (arg1) == -1
6390 && (- TREE_INT_CST_LOW (arg1)
6391 == ((HOST_WIDE_INT) 1 << (width - 1)))
6392 && ! TREE_UNSIGNED (TREE_TYPE (arg1)))
6393 switch (TREE_CODE (t))
6396 return omit_one_operand (type,
6397 convert (type, integer_zero_node),
6400 TREE_SET_CODE (t, EQ_EXPR);
6404 return omit_one_operand (type,
6405 convert (type, integer_one_node),
6408 TREE_SET_CODE (t, NE_EXPR);
6415 else if (TREE_INT_CST_HIGH (arg1) == 0
6416 && (TREE_INT_CST_LOW (arg1)
6417 == ((HOST_WIDE_INT) 1 << (width - 1)) - 1)
6418 && TREE_UNSIGNED (TREE_TYPE (arg1)))
6420 switch (TREE_CODE (t))
6423 return fold (build (GE_EXPR, type,
6424 convert (signed_type (TREE_TYPE (arg0)),
6426 convert (signed_type (TREE_TYPE (arg1)),
6427 integer_zero_node)));
6429 return fold (build (LT_EXPR, type,
6430 convert (signed_type (TREE_TYPE (arg0)),
6432 convert (signed_type (TREE_TYPE (arg1)),
6433 integer_zero_node)));
6441 /* If we are comparing an expression that just has comparisons
6442 of two integer values, arithmetic expressions of those comparisons,
6443 and constants, we can simplify it. There are only three cases
6444 to check: the two values can either be equal, the first can be
6445 greater, or the second can be greater. Fold the expression for
6446 those three values. Since each value must be 0 or 1, we have
6447 eight possibilities, each of which corresponds to the constant 0
6448 or 1 or one of the six possible comparisons.
6450 This handles common cases like (a > b) == 0 but also handles
6451 expressions like ((x > y) - (y > x)) > 0, which supposedly
6452 occur in macroized code. */
6454 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
6456 tree cval1 = 0, cval2 = 0;
6459 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
6460 /* Don't handle degenerate cases here; they should already
6461 have been handled anyway. */
6462 && cval1 != 0 && cval2 != 0
6463 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
6464 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
6465 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
6466 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
6467 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
6468 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
6469 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
6471 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
6472 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
6474 /* We can't just pass T to eval_subst in case cval1 or cval2
6475 was the same as ARG1. */
6478 = fold (build (code, type,
6479 eval_subst (arg0, cval1, maxval, cval2, minval),
6482 = fold (build (code, type,
6483 eval_subst (arg0, cval1, maxval, cval2, maxval),
6486 = fold (build (code, type,
6487 eval_subst (arg0, cval1, minval, cval2, maxval),
6490 /* All three of these results should be 0 or 1. Confirm they
6491 are. Then use those values to select the proper code
6494 if ((integer_zerop (high_result)
6495 || integer_onep (high_result))
6496 && (integer_zerop (equal_result)
6497 || integer_onep (equal_result))
6498 && (integer_zerop (low_result)
6499 || integer_onep (low_result)))
6501 /* Make a 3-bit mask with the high-order bit being the
6502 value for `>', the next for '=', and the low for '<'. */
6503 switch ((integer_onep (high_result) * 4)
6504 + (integer_onep (equal_result) * 2)
6505 + integer_onep (low_result))
6509 return omit_one_operand (type, integer_zero_node, arg0);
6530 return omit_one_operand (type, integer_one_node, arg0);
6533 t = build (code, type, cval1, cval2);
6535 return save_expr (t);
6542 /* If this is a comparison of a field, we may be able to simplify it. */
6543 if ((TREE_CODE (arg0) == COMPONENT_REF
6544 || TREE_CODE (arg0) == BIT_FIELD_REF)
6545 && (code == EQ_EXPR || code == NE_EXPR)
6546 /* Handle the constant case even without -O
6547 to make sure the warnings are given. */
6548 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
6550 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
6554 /* If this is a comparison of complex values and either or both sides
6555 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
6556 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
6557 This may prevent needless evaluations. */
6558 if ((code == EQ_EXPR || code == NE_EXPR)
6559 && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
6560 && (TREE_CODE (arg0) == COMPLEX_EXPR
6561 || TREE_CODE (arg1) == COMPLEX_EXPR
6562 || TREE_CODE (arg0) == COMPLEX_CST
6563 || TREE_CODE (arg1) == COMPLEX_CST))
6565 tree subtype = TREE_TYPE (TREE_TYPE (arg0));
6566 tree real0, imag0, real1, imag1;
6568 arg0 = save_expr (arg0);
6569 arg1 = save_expr (arg1);
6570 real0 = fold (build1 (REALPART_EXPR, subtype, arg0));
6571 imag0 = fold (build1 (IMAGPART_EXPR, subtype, arg0));
6572 real1 = fold (build1 (REALPART_EXPR, subtype, arg1));
6573 imag1 = fold (build1 (IMAGPART_EXPR, subtype, arg1));
6575 return fold (build ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR
6578 fold (build (code, type, real0, real1)),
6579 fold (build (code, type, imag0, imag1))));
6582 /* From here on, the only cases we handle are when the result is
6583 known to be a constant.
6585 To compute GT, swap the arguments and do LT.
6586 To compute GE, do LT and invert the result.
6587 To compute LE, swap the arguments, do LT and invert the result.
6588 To compute NE, do EQ and invert the result.
6590 Therefore, the code below must handle only EQ and LT. */
6592 if (code == LE_EXPR || code == GT_EXPR)
6594 tem = arg0, arg0 = arg1, arg1 = tem;
6595 code = swap_tree_comparison (code);
6598 /* Note that it is safe to invert for real values here because we
6599 will check below in the one case that it matters. */
6603 if (code == NE_EXPR || code == GE_EXPR)
6606 code = invert_tree_comparison (code);
6609 /* Compute a result for LT or EQ if args permit;
6610 otherwise return T. */
6611 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
6613 if (code == EQ_EXPR)
6614 t1 = build_int_2 ((TREE_INT_CST_LOW (arg0)
6615 == TREE_INT_CST_LOW (arg1))
6616 && (TREE_INT_CST_HIGH (arg0)
6617 == TREE_INT_CST_HIGH (arg1)),
6620 t1 = build_int_2 ((TREE_UNSIGNED (TREE_TYPE (arg0))
6621 ? INT_CST_LT_UNSIGNED (arg0, arg1)
6622 : INT_CST_LT (arg0, arg1)),
6626 #if 0 /* This is no longer useful, but breaks some real code. */
6627 /* Assume a nonexplicit constant cannot equal an explicit one,
6628 since such code would be undefined anyway.
6629 Exception: on sysvr4, using #pragma weak,
6630 a label can come out as 0. */
6631 else if (TREE_CODE (arg1) == INTEGER_CST
6632 && !integer_zerop (arg1)
6633 && TREE_CONSTANT (arg0)
6634 && TREE_CODE (arg0) == ADDR_EXPR
6636 t1 = build_int_2 (0, 0);
6638 /* Two real constants can be compared explicitly. */
6639 else if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
6641 /* If either operand is a NaN, the result is false with two
6642 exceptions: First, an NE_EXPR is true on NaNs, but that case
6643 is already handled correctly since we will be inverting the
6644 result for NE_EXPR. Second, if we had inverted a LE_EXPR
6645 or a GE_EXPR into a LT_EXPR, we must return true so that it
6646 will be inverted into false. */
6648 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
6649 || REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
6650 t1 = build_int_2 (invert && code == LT_EXPR, 0);
6652 else if (code == EQ_EXPR)
6653 t1 = build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (arg0),
6654 TREE_REAL_CST (arg1)),
6657 t1 = build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (arg0),
6658 TREE_REAL_CST (arg1)),
6662 if (t1 == NULL_TREE)
6666 TREE_INT_CST_LOW (t1) ^= 1;
6668 TREE_TYPE (t1) = type;
6669 if (TREE_CODE (type) == BOOLEAN_TYPE)
6670 return truthvalue_conversion (t1);
6674 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
6675 so all simple results must be passed through pedantic_non_lvalue. */
6676 if (TREE_CODE (arg0) == INTEGER_CST)
6677 return pedantic_non_lvalue
6678 (TREE_OPERAND (t, (integer_zerop (arg0) ? 2 : 1)));
6679 else if (operand_equal_p (arg1, TREE_OPERAND (expr, 2), 0))
6680 return pedantic_omit_one_operand (type, arg1, arg0);
6682 /* If the second operand is zero, invert the comparison and swap
6683 the second and third operands. Likewise if the second operand
6684 is constant and the third is not or if the third operand is
6685 equivalent to the first operand of the comparison. */
6687 if (integer_zerop (arg1)
6688 || (TREE_CONSTANT (arg1) && ! TREE_CONSTANT (TREE_OPERAND (t, 2)))
6689 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
6690 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
6691 TREE_OPERAND (t, 2),
6692 TREE_OPERAND (arg0, 1))))
6694 /* See if this can be inverted. If it can't, possibly because
6695 it was a floating-point inequality comparison, don't do
6697 tem = invert_truthvalue (arg0);
6699 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
6701 t = build (code, type, tem,
6702 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
6704 /* arg1 should be the first argument of the new T. */
6705 arg1 = TREE_OPERAND (t, 1);
6710 /* If we have A op B ? A : C, we may be able to convert this to a
6711 simpler expression, depending on the operation and the values
6712 of B and C. IEEE floating point prevents this though,
6713 because A or B might be -0.0 or a NaN. */
6715 if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
6716 && (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
6717 || ! FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 0)))
6719 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
6720 arg1, TREE_OPERAND (arg0, 1)))
6722 tree arg2 = TREE_OPERAND (t, 2);
6723 enum tree_code comp_code = TREE_CODE (arg0);
6727 /* If we have A op 0 ? A : -A, this is A, -A, abs (A), or abs (-A),
6728 depending on the comparison operation. */
6729 if ((FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 1)))
6730 ? real_zerop (TREE_OPERAND (arg0, 1))
6731 : integer_zerop (TREE_OPERAND (arg0, 1)))
6732 && TREE_CODE (arg2) == NEGATE_EXPR
6733 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
6737 return pedantic_non_lvalue (negate_expr (arg1));
6739 return pedantic_non_lvalue (convert (type, arg1));
6742 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
6743 arg1 = convert (signed_type (TREE_TYPE (arg1)), arg1);
6744 return pedantic_non_lvalue
6745 (convert (type, fold (build1 (ABS_EXPR,
6746 TREE_TYPE (arg1), arg1))));
6749 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
6750 arg1 = convert (signed_type (TREE_TYPE (arg1)), arg1);
6751 return pedantic_non_lvalue
6752 (negate_expr (convert (type,
6753 fold (build1 (ABS_EXPR,
6760 /* If this is A != 0 ? A : 0, this is simply A. For ==, it is
6763 if (integer_zerop (TREE_OPERAND (arg0, 1)) && integer_zerop (arg2))
6765 if (comp_code == NE_EXPR)
6766 return pedantic_non_lvalue (convert (type, arg1));
6767 else if (comp_code == EQ_EXPR)
6768 return pedantic_non_lvalue (convert (type, integer_zero_node));
6771 /* If this is A op B ? A : B, this is either A, B, min (A, B),
6772 or max (A, B), depending on the operation. */
6774 if (operand_equal_for_comparison_p (TREE_OPERAND (arg0, 1),
6775 arg2, TREE_OPERAND (arg0, 0)))
6777 tree comp_op0 = TREE_OPERAND (arg0, 0);
6778 tree comp_op1 = TREE_OPERAND (arg0, 1);
6779 tree comp_type = TREE_TYPE (comp_op0);
6784 return pedantic_non_lvalue (convert (type, arg2));
6786 return pedantic_non_lvalue (convert (type, arg1));
6789 /* In C++ a ?: expression can be an lvalue, so put the
6790 operand which will be used if they are equal first
6791 so that we can convert this back to the
6792 corresponding COND_EXPR. */
6793 return pedantic_non_lvalue
6794 (convert (type, (fold (build (MIN_EXPR, comp_type,
6795 (comp_code == LE_EXPR
6796 ? comp_op0 : comp_op1),
6797 (comp_code == LE_EXPR
6798 ? comp_op1 : comp_op0))))));
6802 return pedantic_non_lvalue
6803 (convert (type, fold (build (MAX_EXPR, comp_type,
6804 (comp_code == GE_EXPR
6805 ? comp_op0 : comp_op1),
6806 (comp_code == GE_EXPR
6807 ? comp_op1 : comp_op0)))));
6814 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
6815 we might still be able to simplify this. For example,
6816 if C1 is one less or one more than C2, this might have started
6817 out as a MIN or MAX and been transformed by this function.
6818 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
6820 if (INTEGRAL_TYPE_P (type)
6821 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6822 && TREE_CODE (arg2) == INTEGER_CST)
6826 /* We can replace A with C1 in this case. */
6827 arg1 = convert (type, TREE_OPERAND (arg0, 1));
6828 t = build (code, type, TREE_OPERAND (t, 0), arg1,
6829 TREE_OPERAND (t, 2));
6833 /* If C1 is C2 + 1, this is min(A, C2). */
6834 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
6835 && operand_equal_p (TREE_OPERAND (arg0, 1),
6836 const_binop (PLUS_EXPR, arg2,
6837 integer_one_node, 0), 1))
6838 return pedantic_non_lvalue
6839 (fold (build (MIN_EXPR, type, arg1, arg2)));
6843 /* If C1 is C2 - 1, this is min(A, C2). */
6844 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
6845 && operand_equal_p (TREE_OPERAND (arg0, 1),
6846 const_binop (MINUS_EXPR, arg2,
6847 integer_one_node, 0), 1))
6848 return pedantic_non_lvalue
6849 (fold (build (MIN_EXPR, type, arg1, arg2)));
6853 /* If C1 is C2 - 1, this is max(A, C2). */
6854 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
6855 && operand_equal_p (TREE_OPERAND (arg0, 1),
6856 const_binop (MINUS_EXPR, arg2,
6857 integer_one_node, 0), 1))
6858 return pedantic_non_lvalue
6859 (fold (build (MAX_EXPR, type, arg1, arg2)));
6863 /* If C1 is C2 + 1, this is max(A, C2). */
6864 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
6865 && operand_equal_p (TREE_OPERAND (arg0, 1),
6866 const_binop (PLUS_EXPR, arg2,
6867 integer_one_node, 0), 1))
6868 return pedantic_non_lvalue
6869 (fold (build (MAX_EXPR, type, arg1, arg2)));
6878 /* If the second operand is simpler than the third, swap them
6879 since that produces better jump optimization results. */
6880 if ((TREE_CONSTANT (arg1) || TREE_CODE_CLASS (TREE_CODE (arg1)) == 'd'
6881 || TREE_CODE (arg1) == SAVE_EXPR)
6882 && ! (TREE_CONSTANT (TREE_OPERAND (t, 2))
6883 || TREE_CODE_CLASS (TREE_CODE (TREE_OPERAND (t, 2))) == 'd'
6884 || TREE_CODE (TREE_OPERAND (t, 2)) == SAVE_EXPR))
6886 /* See if this can be inverted. If it can't, possibly because
6887 it was a floating-point inequality comparison, don't do
6889 tem = invert_truthvalue (arg0);
6891 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
6893 t = build (code, type, tem,
6894 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
6896 /* arg1 should be the first argument of the new T. */
6897 arg1 = TREE_OPERAND (t, 1);
6902 /* Convert A ? 1 : 0 to simply A. */
6903 if (integer_onep (TREE_OPERAND (t, 1))
6904 && integer_zerop (TREE_OPERAND (t, 2))
6905 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
6906 call to fold will try to move the conversion inside
6907 a COND, which will recurse. In that case, the COND_EXPR
6908 is probably the best choice, so leave it alone. */
6909 && type == TREE_TYPE (arg0))
6910 return pedantic_non_lvalue (arg0);
6912 /* Look for expressions of the form A & 2 ? 2 : 0. The result of this
6913 operation is simply A & 2. */
6915 if (integer_zerop (TREE_OPERAND (t, 2))
6916 && TREE_CODE (arg0) == NE_EXPR
6917 && integer_zerop (TREE_OPERAND (arg0, 1))
6918 && integer_pow2p (arg1)
6919 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
6920 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
6922 return pedantic_non_lvalue (convert (type, TREE_OPERAND (arg0, 0)));
6927 /* When pedantic, a compound expression can be neither an lvalue
6928 nor an integer constant expression. */
6929 if (TREE_SIDE_EFFECTS (arg0) || pedantic)
6931 /* Don't let (0, 0) be null pointer constant. */
6932 if (integer_zerop (arg1))
6933 return build1 (NOP_EXPR, TREE_TYPE (arg1), arg1);
6938 return build_complex (type, arg0, arg1);
6942 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
6944 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
6945 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
6946 TREE_OPERAND (arg0, 1));
6947 else if (TREE_CODE (arg0) == COMPLEX_CST)
6948 return TREE_REALPART (arg0);
6949 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
6950 return fold (build (TREE_CODE (arg0), type,
6951 fold (build1 (REALPART_EXPR, type,
6952 TREE_OPERAND (arg0, 0))),
6953 fold (build1 (REALPART_EXPR,
6954 type, TREE_OPERAND (arg0, 1)))));
6958 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
6959 return convert (type, integer_zero_node);
6960 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
6961 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
6962 TREE_OPERAND (arg0, 0));
6963 else if (TREE_CODE (arg0) == COMPLEX_CST)
6964 return TREE_IMAGPART (arg0);
6965 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
6966 return fold (build (TREE_CODE (arg0), type,
6967 fold (build1 (IMAGPART_EXPR, type,
6968 TREE_OPERAND (arg0, 0))),
6969 fold (build1 (IMAGPART_EXPR, type,
6970 TREE_OPERAND (arg0, 1)))));
6973 /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
6975 case CLEANUP_POINT_EXPR:
6976 if (! has_cleanups (arg0))
6977 return TREE_OPERAND (t, 0);
6980 enum tree_code code0 = TREE_CODE (arg0);
6981 int kind0 = TREE_CODE_CLASS (code0);
6982 tree arg00 = TREE_OPERAND (arg0, 0);
6985 if (kind0 == '1' || code0 == TRUTH_NOT_EXPR)
6986 return fold (build1 (code0, type,
6987 fold (build1 (CLEANUP_POINT_EXPR,
6988 TREE_TYPE (arg00), arg00))));
6990 if (kind0 == '<' || kind0 == '2'
6991 || code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR
6992 || code0 == TRUTH_AND_EXPR || code0 == TRUTH_OR_EXPR
6993 || code0 == TRUTH_XOR_EXPR)
6995 arg01 = TREE_OPERAND (arg0, 1);
6997 if (TREE_CONSTANT (arg00)
6998 || ((code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR)
6999 && ! has_cleanups (arg00)))
7000 return fold (build (code0, type, arg00,
7001 fold (build1 (CLEANUP_POINT_EXPR,
7002 TREE_TYPE (arg01), arg01))));
7004 if (TREE_CONSTANT (arg01))
7005 return fold (build (code0, type,
7006 fold (build1 (CLEANUP_POINT_EXPR,
7007 TREE_TYPE (arg00), arg00)),
7016 } /* switch (code) */
7019 /* Determine if first argument is a multiple of second argument. Return 0 if
7020 it is not, or we cannot easily determined it to be.
7022 An example of the sort of thing we care about (at this point; this routine
7023 could surely be made more general, and expanded to do what the *_DIV_EXPR's
7024 fold cases do now) is discovering that
7026 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7032 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
7034 This code also handles discovering that
7036 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7038 is a multiple of 8 so we don't have to worry about dealing with a
7041 Note that we *look* inside a SAVE_EXPR only to determine how it was
7042 calculated; it is not safe for fold to do much of anything else with the
7043 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
7044 at run time. For example, the latter example above *cannot* be implemented
7045 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
7046 evaluation time of the original SAVE_EXPR is not necessarily the same at
7047 the time the new expression is evaluated. The only optimization of this
7048 sort that would be valid is changing
7050 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
7054 SAVE_EXPR (I) * SAVE_EXPR (J)
7056 (where the same SAVE_EXPR (J) is used in the original and the
7057 transformed version). */
7060 multiple_of_p (type, top, bottom)
7065 if (operand_equal_p (top, bottom, 0))
7068 if (TREE_CODE (type) != INTEGER_TYPE)
7071 switch (TREE_CODE (top))
7074 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
7075 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
7079 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
7080 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
7083 /* Can't handle conversions from non-integral or wider integral type. */
7084 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
7085 || (TYPE_PRECISION (type)
7086 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
7089 /* .. fall through ... */
7092 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
7095 if ((TREE_CODE (bottom) != INTEGER_CST)
7096 || (tree_int_cst_sgn (top) < 0)
7097 || (tree_int_cst_sgn (bottom) < 0))
7099 return integer_zerop (const_binop (TRUNC_MOD_EXPR,