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 void const_binop_1 PROTO((PTR));
70 static tree const_binop PROTO((enum tree_code, tree, tree, int));
71 static void fold_convert_1 PROTO((PTR));
72 static tree fold_convert PROTO((tree, tree));
73 static enum tree_code invert_tree_comparison PROTO((enum tree_code));
74 static enum tree_code swap_tree_comparison PROTO((enum tree_code));
75 static int truth_value_p PROTO((enum tree_code));
76 static int operand_equal_for_comparison_p PROTO((tree, tree, tree));
77 static int twoval_comparison_p PROTO((tree, tree *, tree *, int *));
78 static tree eval_subst PROTO((tree, tree, tree, tree, tree));
79 static tree omit_one_operand PROTO((tree, tree, tree));
80 static tree pedantic_omit_one_operand PROTO((tree, tree, tree));
81 static tree distribute_bit_expr PROTO((enum tree_code, tree, tree, tree));
82 static tree make_bit_field_ref PROTO((tree, tree, int, int, int));
83 static tree optimize_bit_field_compare PROTO((enum tree_code, tree,
85 static tree decode_field_reference PROTO((tree, int *, int *,
86 enum machine_mode *, int *,
87 int *, tree *, tree *));
88 static int all_ones_mask_p PROTO((tree, int));
89 static int simple_operand_p PROTO((tree));
90 static tree range_binop PROTO((enum tree_code, tree, tree, int,
92 static tree make_range PROTO((tree, int *, tree *, tree *));
93 static tree build_range_check PROTO((tree, tree, int, tree, tree));
94 static int merge_ranges PROTO((int *, tree *, tree *, int, tree, tree,
96 static tree fold_range_test PROTO((tree));
97 static tree unextend PROTO((tree, int, int, tree));
98 static tree fold_truthop PROTO((enum tree_code, tree, tree, tree));
99 static tree optimize_minmax_comparison PROTO((tree));
100 static tree extract_muldiv PROTO((tree, tree, enum tree_code, tree));
101 static tree strip_compound_expr PROTO((tree, tree));
102 static int multiple_of_p PROTO((tree, tree, tree));
103 static tree constant_boolean_node PROTO((int, tree));
104 static int count_cond PROTO((tree, int));
107 #define BRANCH_COST 1
110 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
111 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
112 and SUM1. Then this yields nonzero if overflow occurred during the
115 Overflow occurs if A and B have the same sign, but A and SUM differ in
116 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
118 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
120 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
121 We do that by representing the two-word integer in 4 words, with only
122 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
123 number. The value of the word is LOWPART + HIGHPART * BASE. */
126 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
127 #define HIGHPART(x) \
128 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
129 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
131 /* Unpack a two-word integer into 4 words.
132 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
133 WORDS points to the array of HOST_WIDE_INTs. */
136 encode (words, low, hi)
137 HOST_WIDE_INT *words;
138 HOST_WIDE_INT low, hi;
140 words[0] = LOWPART (low);
141 words[1] = HIGHPART (low);
142 words[2] = LOWPART (hi);
143 words[3] = HIGHPART (hi);
146 /* Pack an array of 4 words into a two-word integer.
147 WORDS points to the array of words.
148 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
151 decode (words, low, hi)
152 HOST_WIDE_INT *words;
153 HOST_WIDE_INT *low, *hi;
155 *low = words[0] + words[1] * BASE;
156 *hi = words[2] + words[3] * BASE;
159 /* Make the integer constant T valid for its type by setting to 0 or 1 all
160 the bits in the constant that don't belong in the type.
162 Return 1 if a signed overflow occurs, 0 otherwise. If OVERFLOW is
163 nonzero, a signed overflow has already occurred in calculating T, so
166 Make the real constant T valid for its type by calling CHECK_FLOAT_VALUE,
170 force_fit_type (t, overflow)
174 HOST_WIDE_INT low, high;
177 if (TREE_CODE (t) == REAL_CST)
179 #ifdef CHECK_FLOAT_VALUE
180 CHECK_FLOAT_VALUE (TYPE_MODE (TREE_TYPE (t)), TREE_REAL_CST (t),
186 else if (TREE_CODE (t) != INTEGER_CST)
189 low = TREE_INT_CST_LOW (t);
190 high = TREE_INT_CST_HIGH (t);
192 if (POINTER_TYPE_P (TREE_TYPE (t)))
195 prec = TYPE_PRECISION (TREE_TYPE (t));
197 /* First clear all bits that are beyond the type's precision. */
199 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
201 else if (prec > HOST_BITS_PER_WIDE_INT)
202 TREE_INT_CST_HIGH (t)
203 &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
206 TREE_INT_CST_HIGH (t) = 0;
207 if (prec < HOST_BITS_PER_WIDE_INT)
208 TREE_INT_CST_LOW (t) &= ~((HOST_WIDE_INT) (-1) << prec);
211 /* Unsigned types do not suffer sign extension or overflow. */
212 if (TREE_UNSIGNED (TREE_TYPE (t)))
215 /* If the value's sign bit is set, extend the sign. */
216 if (prec != 2 * HOST_BITS_PER_WIDE_INT
217 && (prec > HOST_BITS_PER_WIDE_INT
218 ? (TREE_INT_CST_HIGH (t)
219 & ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)))
220 : TREE_INT_CST_LOW (t) & ((HOST_WIDE_INT) 1 << (prec - 1))))
222 /* Value is negative:
223 set to 1 all the bits that are outside this type's precision. */
224 if (prec > HOST_BITS_PER_WIDE_INT)
225 TREE_INT_CST_HIGH (t)
226 |= ((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 /* Return 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);
978 /* Convert C9X hexadecimal floating point string constant S. Return
979 real value type in mode MODE. This function uses the host computer's
980 floating point arithmetic when there is no REAL_ARITHMETIC. */
983 real_hex_to_f (s, mode)
985 enum machine_mode mode;
989 unsigned HOST_WIDE_INT low, high;
990 int expon, shcount, nrmcount, k;
991 int sign, expsign, isfloat;
992 int lost = 0;/* Nonzero low order bits shifted out and discarded. */
993 int frexpon = 0; /* Bits after the decimal point. */
994 int expon = 0; /* Value of exponent. */
995 int decpt = 0; /* How many decimal points. */
996 int gotp = 0; /* How many P's. */
1003 while (*p == ' ' || *p == '\t')
1006 /* Sign, if any, comes first. */
1014 /* The string is supposed to start with 0x or 0X . */
1018 if (*p == 'x' || *p == 'X')
1032 while ((c = *p) != '\0')
1034 if ((c >= '0' && c <= '9') || (c >= 'A' && c <= 'F')
1035 || (c >= 'a' && c <= 'f'))
1045 if ((high & 0xf0000000) == 0)
1047 high = (high << 4) + ((low >> 28) & 15);
1048 low = (low << 4) + k;
1055 /* Record nonzero lost bits. */
1068 else if (c == 'p' || c == 'P')
1072 /* Sign of exponent. */
1079 /* Value of exponent.
1080 The exponent field is a decimal integer. */
1083 k = (*p++ & 0x7f) - '0';
1084 expon = 10 * expon + k;
1088 /* F suffix is ambiguous in the significand part
1089 so it must appear after the decimal exponent field. */
1090 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))
1112 /* There must be either one decimal point or one p. */
1113 if (decpt == 0 && gotp == 0)
1117 if (high == 0 && low == 0)
1129 /* Leave a high guard bit for carry-out. */
1130 if ((high & 0x80000000) != 0)
1133 low = (low >> 1) | (high << 31);
1138 if ((high & 0xffff8000) == 0)
1140 high = (high << 16) + ((low >> 16) & 0xffff);
1145 while ((high & 0xc0000000) == 0)
1147 high = (high << 1) + ((low >> 31) & 1);
1152 if (isfloat || GET_MODE_SIZE(mode) == UNITS_PER_WORD)
1154 /* Keep 24 bits precision, bits 0x7fffff80.
1155 Rounding bit is 0x40. */
1156 lost = lost | low | (high & 0x3f);
1160 if ((high & 0x80) || lost)
1167 /* We need real.c to do long double formats, so here default
1168 to double precision. */
1169 #if HOST_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
1171 Keep 53 bits precision, bits 0x7fffffff fffffc00.
1172 Rounding bit is low word 0x200. */
1173 lost = lost | (low & 0x1ff);
1176 if ((low & 0x400) || lost)
1178 low = (low + 0x200) & 0xfffffc00;
1185 /* Assume it's a VAX with 56-bit significand,
1186 bits 0x7fffffff ffffff80. */
1187 lost = lost | (low & 0x7f);
1190 if ((low & 0x80) || lost)
1192 low = (low + 0x40) & 0xffffff80;
1202 ip = REAL_VALUE_LDEXP (ip, 32) + (double) low;
1203 /* Apply shifts and exponent value as power of 2. */
1204 ip = REAL_VALUE_LDEXP (ip, expon - (nrmcount + frexpon));
1211 #endif /* no REAL_ARITHMETIC */
1213 /* Given T, an expression, return the negation of T. Allow for T to be
1214 null, in which case return null. */
1226 type = TREE_TYPE (t);
1227 STRIP_SIGN_NOPS (t);
1229 switch (TREE_CODE (t))
1233 if (! TREE_UNSIGNED (type)
1234 && 0 != (tem = fold (build1 (NEGATE_EXPR, type, t)))
1235 && ! TREE_OVERFLOW (tem))
1240 return convert (type, TREE_OPERAND (t, 0));
1243 /* - (A - B) -> B - A */
1244 if (! FLOAT_TYPE_P (type) || flag_fast_math)
1245 return convert (type,
1246 fold (build (MINUS_EXPR, TREE_TYPE (t),
1247 TREE_OPERAND (t, 1),
1248 TREE_OPERAND (t, 0))));
1255 return convert (type, build1 (NEGATE_EXPR, TREE_TYPE (t), t));
1258 /* Split a tree IN into a constant, literal and variable parts that could be
1259 combined with CODE to make IN. "constant" means an expression with
1260 TREE_CONSTANT but that isn't an actual constant. CODE must be a
1261 commutative arithmetic operation. Store the constant part into *CONP,
1262 the literal in &LITP and return the variable part. If a part isn't
1263 present, set it to null. If the tree does not decompose in this way,
1264 return the entire tree as the variable part and the other parts as null.
1266 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
1267 case, we negate an operand that was subtracted. If NEGATE_P is true, we
1268 are negating all of IN.
1270 If IN is itself a literal or constant, return it as appropriate.
1272 Note that we do not guarantee that any of the three values will be the
1273 same type as IN, but they will have the same signedness and mode. */
1276 split_tree (in, code, conp, litp, negate_p)
1278 enum tree_code code;
1287 /* Strip any conversions that don't change the machine mode or signedness. */
1288 STRIP_SIGN_NOPS (in);
1290 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST)
1292 else if (TREE_CONSTANT (in))
1295 else if (TREE_CODE (in) == code
1296 || (! FLOAT_TYPE_P (TREE_TYPE (in))
1297 /* We can associate addition and subtraction together (even
1298 though the C standard doesn't say so) for integers because
1299 the value is not affected. For reals, the value might be
1300 affected, so we can't. */
1301 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
1302 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
1304 tree op0 = TREE_OPERAND (in, 0);
1305 tree op1 = TREE_OPERAND (in, 1);
1306 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
1307 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
1309 /* First see if either of the operands is a literal, then a constant. */
1310 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
1311 *litp = op0, op0 = 0;
1312 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST)
1313 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
1315 if (op0 != 0 && TREE_CONSTANT (op0))
1316 *conp = op0, op0 = 0;
1317 else if (op1 != 0 && TREE_CONSTANT (op1))
1318 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
1320 /* If we haven't dealt with either operand, this is not a case we can
1321 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1322 if (op0 != 0 && op1 != 0)
1327 var = op1, neg_var_p = neg1_p;
1329 /* Now do any needed negations. */
1330 if (neg_litp_p) *litp = negate_expr (*litp);
1331 if (neg_conp_p) *conp = negate_expr (*conp);
1332 if (neg_var_p) var = negate_expr (var);
1339 var = negate_expr (var);
1340 *conp = negate_expr (*conp);
1341 *litp = negate_expr (*litp);
1347 /* Re-associate trees split by the above function. T1 and T2 are either
1348 expressions to associate or null. Return the new expression, if any. If
1349 we build an operation, do it in TYPE and with CODE, except if CODE is a
1350 MINUS_EXPR, in which case we use PLUS_EXPR since split_tree will already
1351 have taken care of the negations. */
1354 associate_trees (t1, t2, code, type)
1356 enum tree_code code;
1364 if (code == MINUS_EXPR)
1367 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1368 try to fold this since we will have infinite recursion. But do
1369 deal with any NEGATE_EXPRs. */
1370 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
1371 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1373 if (TREE_CODE (t1) == NEGATE_EXPR)
1374 return build (MINUS_EXPR, type, convert (type, t2),
1375 convert (type, TREE_OPERAND (t1, 0)));
1376 else if (TREE_CODE (t2) == NEGATE_EXPR)
1377 return build (MINUS_EXPR, type, convert (type, t1),
1378 convert (type, TREE_OPERAND (t2, 0)));
1380 return build (code, type, convert (type, t1), convert (type, t2));
1383 return fold (build (code, type, convert (type, t1), convert (type, t2)));
1386 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1387 to produce a new constant.
1389 If NOTRUNC is nonzero, do not truncate the result to fit the data type.
1390 If FORSIZE is nonzero, compute overflow for unsigned types. */
1393 int_const_binop (code, arg1, arg2, notrunc, forsize)
1394 enum tree_code code;
1395 register tree arg1, arg2;
1396 int notrunc, forsize;
1398 HOST_WIDE_INT int1l, int1h, int2l, int2h;
1399 HOST_WIDE_INT low, hi;
1400 HOST_WIDE_INT garbagel, garbageh;
1402 int uns = TREE_UNSIGNED (TREE_TYPE (arg1));
1404 int no_overflow = 0;
1406 int1l = TREE_INT_CST_LOW (arg1);
1407 int1h = TREE_INT_CST_HIGH (arg1);
1408 int2l = TREE_INT_CST_LOW (arg2);
1409 int2h = TREE_INT_CST_HIGH (arg2);
1414 low = int1l | int2l, hi = int1h | int2h;
1418 low = int1l ^ int2l, hi = int1h ^ int2h;
1422 low = int1l & int2l, hi = int1h & int2h;
1425 case BIT_ANDTC_EXPR:
1426 low = int1l & ~int2l, hi = int1h & ~int2h;
1432 /* It's unclear from the C standard whether shifts can overflow.
1433 The following code ignores overflow; perhaps a C standard
1434 interpretation ruling is needed. */
1435 lshift_double (int1l, int1h, int2l,
1436 TYPE_PRECISION (TREE_TYPE (arg1)),
1445 lrotate_double (int1l, int1h, int2l,
1446 TYPE_PRECISION (TREE_TYPE (arg1)),
1451 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1455 neg_double (int2l, int2h, &low, &hi);
1456 add_double (int1l, int1h, low, hi, &low, &hi);
1457 overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
1461 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1464 case TRUNC_DIV_EXPR:
1465 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1466 case EXACT_DIV_EXPR:
1467 /* This is a shortcut for a common special case. */
1468 if (int2h == 0 && int2l > 0
1469 && ! TREE_CONSTANT_OVERFLOW (arg1)
1470 && ! TREE_CONSTANT_OVERFLOW (arg2)
1471 && int1h == 0 && int1l >= 0)
1473 if (code == CEIL_DIV_EXPR)
1475 low = int1l / int2l, hi = 0;
1479 /* ... fall through ... */
1481 case ROUND_DIV_EXPR:
1482 if (int2h == 0 && int2l == 1)
1484 low = int1l, hi = int1h;
1487 if (int1l == int2l && int1h == int2h
1488 && ! (int1l == 0 && int1h == 0))
1493 overflow = div_and_round_double (code, uns,
1494 int1l, int1h, int2l, int2h,
1495 &low, &hi, &garbagel, &garbageh);
1498 case TRUNC_MOD_EXPR:
1499 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1500 /* This is a shortcut for a common special case. */
1501 if (int2h == 0 && int2l > 0
1502 && ! TREE_CONSTANT_OVERFLOW (arg1)
1503 && ! TREE_CONSTANT_OVERFLOW (arg2)
1504 && int1h == 0 && int1l >= 0)
1506 if (code == CEIL_MOD_EXPR)
1508 low = int1l % int2l, hi = 0;
1512 /* ... fall through ... */
1514 case ROUND_MOD_EXPR:
1515 overflow = div_and_round_double (code, uns,
1516 int1l, int1h, int2l, int2h,
1517 &garbagel, &garbageh, &low, &hi);
1523 low = (((unsigned HOST_WIDE_INT) int1h
1524 < (unsigned HOST_WIDE_INT) int2h)
1525 || (((unsigned HOST_WIDE_INT) int1h
1526 == (unsigned HOST_WIDE_INT) int2h)
1527 && ((unsigned HOST_WIDE_INT) int1l
1528 < (unsigned HOST_WIDE_INT) int2l)));
1530 low = ((int1h < int2h)
1531 || ((int1h == int2h)
1532 && ((unsigned HOST_WIDE_INT) int1l
1533 < (unsigned HOST_WIDE_INT) int2l)));
1535 if (low == (code == MIN_EXPR))
1536 low = int1l, hi = int1h;
1538 low = int2l, hi = int2h;
1545 if (TREE_TYPE (arg1) == sizetype && hi == 0
1547 && (TYPE_MAX_VALUE (sizetype) == NULL
1548 || low <= TREE_INT_CST_LOW (TYPE_MAX_VALUE (sizetype)))
1550 && ! TREE_OVERFLOW (arg1) && ! TREE_OVERFLOW (arg2))
1554 t = build_int_2 (low, hi);
1555 TREE_TYPE (t) = TREE_TYPE (arg1);
1559 = ((notrunc ? (!uns || forsize) && overflow
1560 : force_fit_type (t, (!uns || forsize) && overflow) && ! no_overflow)
1561 | TREE_OVERFLOW (arg1)
1562 | TREE_OVERFLOW (arg2));
1564 /* If we're doing a size calculation, unsigned arithmetic does overflow.
1565 So check if force_fit_type truncated the value. */
1567 && ! TREE_OVERFLOW (t)
1568 && (TREE_INT_CST_HIGH (t) != hi
1569 || TREE_INT_CST_LOW (t) != low))
1570 TREE_OVERFLOW (t) = 1;
1572 TREE_CONSTANT_OVERFLOW (t) = (TREE_OVERFLOW (t)
1573 | TREE_CONSTANT_OVERFLOW (arg1)
1574 | TREE_CONSTANT_OVERFLOW (arg2));
1578 /* Define input and output argument for const_binop_1. */
1581 enum tree_code code; /* Input: tree code for operation*/
1582 tree type; /* Input: tree type for operation. */
1583 REAL_VALUE_TYPE d1, d2; /* Input: floating point operands. */
1584 tree t; /* Output: constant for result. */
1587 /* Do the real arithmetic for const_binop while protected by a
1588 float overflow handler. */
1591 const_binop_1 (data)
1594 struct cb_args *args = (struct cb_args *) data;
1595 REAL_VALUE_TYPE value;
1597 #ifdef REAL_ARITHMETIC
1598 REAL_ARITHMETIC (value, args->code, args->d1, args->d2);
1603 value = args->d1 + args->d2;
1607 value = args->d1 - args->d2;
1611 value = args->d1 * args->d2;
1615 #ifndef REAL_INFINITY
1620 value = args->d1 / args->d2;
1624 value = MIN (args->d1, args->d2);
1628 value = MAX (args->d1, args->d2);
1634 #endif /* no REAL_ARITHMETIC */
1637 = build_real (args->type,
1638 real_value_truncate (TYPE_MODE (args->type), value));
1641 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1642 constant. We assume ARG1 and ARG2 have the same data type, or at least
1643 are the same kind of constant and the same machine mode.
1645 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1648 const_binop (code, arg1, arg2, notrunc)
1649 enum tree_code code;
1650 register tree arg1, arg2;
1653 STRIP_NOPS (arg1); STRIP_NOPS (arg2);
1655 if (TREE_CODE (arg1) == INTEGER_CST)
1656 return int_const_binop (code, arg1, arg2, notrunc, 0);
1658 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1659 if (TREE_CODE (arg1) == REAL_CST)
1665 struct cb_args args;
1667 d1 = TREE_REAL_CST (arg1);
1668 d2 = TREE_REAL_CST (arg2);
1670 /* If either operand is a NaN, just return it. Otherwise, set up
1671 for floating-point trap; we return an overflow. */
1672 if (REAL_VALUE_ISNAN (d1))
1674 else if (REAL_VALUE_ISNAN (d2))
1677 /* Setup input for const_binop_1() */
1678 args.type = TREE_TYPE (arg1);
1683 if (do_float_handler (const_binop_1, (PTR) &args))
1684 /* Receive output from const_binop_1. */
1688 /* We got an exception from const_binop_1. */
1689 t = copy_node (arg1);
1694 = (force_fit_type (t, overflow)
1695 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
1696 TREE_CONSTANT_OVERFLOW (t)
1698 | TREE_CONSTANT_OVERFLOW (arg1)
1699 | TREE_CONSTANT_OVERFLOW (arg2);
1702 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
1703 if (TREE_CODE (arg1) == COMPLEX_CST)
1705 register tree type = TREE_TYPE (arg1);
1706 register tree r1 = TREE_REALPART (arg1);
1707 register tree i1 = TREE_IMAGPART (arg1);
1708 register tree r2 = TREE_REALPART (arg2);
1709 register tree i2 = TREE_IMAGPART (arg2);
1715 t = build_complex (type,
1716 const_binop (PLUS_EXPR, r1, r2, notrunc),
1717 const_binop (PLUS_EXPR, i1, i2, notrunc));
1721 t = build_complex (type,
1722 const_binop (MINUS_EXPR, r1, r2, notrunc),
1723 const_binop (MINUS_EXPR, i1, i2, notrunc));
1727 t = build_complex (type,
1728 const_binop (MINUS_EXPR,
1729 const_binop (MULT_EXPR,
1731 const_binop (MULT_EXPR,
1734 const_binop (PLUS_EXPR,
1735 const_binop (MULT_EXPR,
1737 const_binop (MULT_EXPR,
1744 register tree magsquared
1745 = const_binop (PLUS_EXPR,
1746 const_binop (MULT_EXPR, r2, r2, notrunc),
1747 const_binop (MULT_EXPR, i2, i2, notrunc),
1750 t = build_complex (type,
1752 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1753 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1754 const_binop (PLUS_EXPR,
1755 const_binop (MULT_EXPR, r1, r2,
1757 const_binop (MULT_EXPR, i1, i2,
1760 magsquared, notrunc),
1762 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1763 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1764 const_binop (MINUS_EXPR,
1765 const_binop (MULT_EXPR, i1, r2,
1767 const_binop (MULT_EXPR, r1, i2,
1770 magsquared, notrunc));
1782 /* Return an INTEGER_CST with value whose HOST_BITS_PER_WIDE_INT bits are
1783 given by HIGH and whose HOST_BITS_PER_WIDE_INT bits are given by NUMBER.
1785 If BIT_P is nonzero, this represents a size in bit and the type of the
1786 result will be bitsizetype, othewise it represents a size in bytes and
1787 the type of the result will be sizetype. */
1790 size_int_wide (number, high, bit_p)
1791 unsigned HOST_WIDE_INT number, high;
1794 /* Type-size nodes already made for small sizes. */
1795 static tree size_table[2 * HOST_BITS_PER_WIDE_INT + 1][2];
1796 static int init_p = 0;
1799 if (ggc_p && ! init_p)
1801 ggc_add_tree_root ((tree *) size_table,
1802 sizeof size_table / sizeof (tree));
1806 if (number < 2*HOST_BITS_PER_WIDE_INT + 1 && high == 0
1807 && size_table[number][bit_p] != 0)
1808 return size_table[number][bit_p];
1810 if (number < 2*HOST_BITS_PER_WIDE_INT + 1 && high == 0)
1814 /* Make this a permanent node. */
1815 push_obstacks_nochange ();
1816 end_temporary_allocation ();
1819 t = build_int_2 (number, 0);
1820 TREE_TYPE (t) = bit_p ? bitsizetype : sizetype;
1821 size_table[number][bit_p] = t;
1829 t = build_int_2 (number, high);
1830 TREE_TYPE (t) = bit_p ? bitsizetype : sizetype;
1831 TREE_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (t) = force_fit_type (t, 0);
1835 /* Combine operands OP1 and OP2 with arithmetic operation CODE.
1836 CODE is a tree code. Data type is taken from `sizetype',
1837 If the operands are constant, so is the result. */
1840 size_binop (code, arg0, arg1)
1841 enum tree_code code;
1844 /* Handle the special case of two integer constants faster. */
1845 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1847 /* And some specific cases even faster than that. */
1848 if (code == PLUS_EXPR && integer_zerop (arg0))
1850 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1851 && integer_zerop (arg1))
1853 else if (code == MULT_EXPR && integer_onep (arg0))
1856 /* Handle general case of two integer constants. */
1857 return int_const_binop (code, arg0, arg1, 0, 1);
1860 if (arg0 == error_mark_node || arg1 == error_mark_node)
1861 return error_mark_node;
1863 return fold (build (code, sizetype, arg0, arg1));
1866 /* Combine operands OP1 and OP2 with arithmetic operation CODE.
1867 CODE is a tree code. Data type is taken from `ssizetype',
1868 If the operands are constant, so is the result. */
1871 ssize_binop (code, arg0, arg1)
1872 enum tree_code code;
1875 /* Handle the special case of two integer constants faster. */
1876 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1878 /* And some specific cases even faster than that. */
1879 if (code == PLUS_EXPR && integer_zerop (arg0))
1881 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1882 && integer_zerop (arg1))
1884 else if (code == MULT_EXPR && integer_onep (arg0))
1887 /* Handle general case of two integer constants. We convert
1888 arg0 to ssizetype because int_const_binop uses its type for the
1890 arg0 = convert (ssizetype, arg0);
1891 return int_const_binop (code, arg0, arg1, 0, 0);
1894 if (arg0 == error_mark_node || arg1 == error_mark_node)
1895 return error_mark_node;
1897 return fold (build (code, ssizetype, arg0, arg1));
1900 /* This structure is used to communicate arguments to fold_convert_1. */
1903 tree arg1; /* Input: value to convert. */
1904 tree type; /* Input: type to convert value to. */
1905 tree t; /* Ouput: result of conversion. */
1908 /* Function to convert floating-point constants, protected by floating
1909 point exception handler. */
1912 fold_convert_1 (data)
1915 struct fc_args * args = (struct fc_args *) data;
1917 args->t = build_real (args->type,
1918 real_value_truncate (TYPE_MODE (args->type),
1919 TREE_REAL_CST (args->arg1)));
1922 /* Given T, a tree representing type conversion of ARG1, a constant,
1923 return a constant tree representing the result of conversion. */
1926 fold_convert (t, arg1)
1930 register tree type = TREE_TYPE (t);
1933 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
1935 if (TREE_CODE (arg1) == INTEGER_CST)
1937 /* If we would build a constant wider than GCC supports,
1938 leave the conversion unfolded. */
1939 if (TYPE_PRECISION (type) > 2 * HOST_BITS_PER_WIDE_INT)
1942 /* Given an integer constant, make new constant with new type,
1943 appropriately sign-extended or truncated. */
1944 t = build_int_2 (TREE_INT_CST_LOW (arg1),
1945 TREE_INT_CST_HIGH (arg1));
1946 TREE_TYPE (t) = type;
1947 /* Indicate an overflow if (1) ARG1 already overflowed,
1948 or (2) force_fit_type indicates an overflow.
1949 Tell force_fit_type that an overflow has already occurred
1950 if ARG1 is a too-large unsigned value and T is signed.
1951 But don't indicate an overflow if converting a pointer. */
1953 = ((force_fit_type (t,
1954 (TREE_INT_CST_HIGH (arg1) < 0
1955 && (TREE_UNSIGNED (type)
1956 < TREE_UNSIGNED (TREE_TYPE (arg1)))))
1957 && ! POINTER_TYPE_P (TREE_TYPE (arg1)))
1958 || TREE_OVERFLOW (arg1));
1959 TREE_CONSTANT_OVERFLOW (t)
1960 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1962 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1963 else if (TREE_CODE (arg1) == REAL_CST)
1965 /* Don't initialize these, use assignments.
1966 Initialized local aggregates don't work on old compilers. */
1970 tree type1 = TREE_TYPE (arg1);
1973 x = TREE_REAL_CST (arg1);
1974 l = real_value_from_int_cst (type1, TYPE_MIN_VALUE (type));
1976 no_upper_bound = (TYPE_MAX_VALUE (type) == NULL);
1977 if (!no_upper_bound)
1978 u = real_value_from_int_cst (type1, TYPE_MAX_VALUE (type));
1980 /* See if X will be in range after truncation towards 0.
1981 To compensate for truncation, move the bounds away from 0,
1982 but reject if X exactly equals the adjusted bounds. */
1983 #ifdef REAL_ARITHMETIC
1984 REAL_ARITHMETIC (l, MINUS_EXPR, l, dconst1);
1985 if (!no_upper_bound)
1986 REAL_ARITHMETIC (u, PLUS_EXPR, u, dconst1);
1989 if (!no_upper_bound)
1992 /* If X is a NaN, use zero instead and show we have an overflow.
1993 Otherwise, range check. */
1994 if (REAL_VALUE_ISNAN (x))
1995 overflow = 1, x = dconst0;
1996 else if (! (REAL_VALUES_LESS (l, x)
1998 && REAL_VALUES_LESS (x, u)))
2001 #ifndef REAL_ARITHMETIC
2003 HOST_WIDE_INT low, high;
2004 HOST_WIDE_INT half_word
2005 = (HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2);
2010 high = (HOST_WIDE_INT) (x / half_word / half_word);
2011 x -= (REAL_VALUE_TYPE) high * half_word * half_word;
2012 if (x >= (REAL_VALUE_TYPE) half_word * half_word / 2)
2014 low = x - (REAL_VALUE_TYPE) half_word * half_word / 2;
2015 low |= (HOST_WIDE_INT) -1 << (HOST_BITS_PER_WIDE_INT - 1);
2018 low = (HOST_WIDE_INT) x;
2019 if (TREE_REAL_CST (arg1) < 0)
2020 neg_double (low, high, &low, &high);
2021 t = build_int_2 (low, high);
2025 HOST_WIDE_INT low, high;
2026 REAL_VALUE_TO_INT (&low, &high, x);
2027 t = build_int_2 (low, high);
2030 TREE_TYPE (t) = type;
2032 = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
2033 TREE_CONSTANT_OVERFLOW (t)
2034 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
2036 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
2037 TREE_TYPE (t) = type;
2039 else if (TREE_CODE (type) == REAL_TYPE)
2041 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
2042 if (TREE_CODE (arg1) == INTEGER_CST)
2043 return build_real_from_int_cst (type, arg1);
2044 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
2045 if (TREE_CODE (arg1) == REAL_CST)
2047 struct fc_args args;
2049 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
2052 TREE_TYPE (arg1) = type;
2056 /* Setup input for fold_convert_1() */
2060 if (do_float_handler (fold_convert_1, (PTR) &args))
2062 /* Receive output from fold_convert_1() */
2067 /* We got an exception from fold_convert_1() */
2069 t = copy_node (arg1);
2073 = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
2074 TREE_CONSTANT_OVERFLOW (t)
2075 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
2079 TREE_CONSTANT (t) = 1;
2083 /* Return an expr equal to X but certainly not valid as an lvalue. */
2091 /* These things are certainly not lvalues. */
2092 if (TREE_CODE (x) == NON_LVALUE_EXPR
2093 || TREE_CODE (x) == INTEGER_CST
2094 || TREE_CODE (x) == REAL_CST
2095 || TREE_CODE (x) == STRING_CST
2096 || TREE_CODE (x) == ADDR_EXPR)
2099 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
2100 TREE_CONSTANT (result) = TREE_CONSTANT (x);
2104 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
2105 Zero means allow extended lvalues. */
2107 int pedantic_lvalues;
2109 /* When pedantic, return an expr equal to X but certainly not valid as a
2110 pedantic lvalue. Otherwise, return X. */
2113 pedantic_non_lvalue (x)
2116 if (pedantic_lvalues)
2117 return non_lvalue (x);
2122 /* Given a tree comparison code, return the code that is the logical inverse
2123 of the given code. It is not safe to do this for floating-point
2124 comparisons, except for NE_EXPR and EQ_EXPR. */
2126 static enum tree_code
2127 invert_tree_comparison (code)
2128 enum tree_code code;
2149 /* Similar, but return the comparison that results if the operands are
2150 swapped. This is safe for floating-point. */
2152 static enum tree_code
2153 swap_tree_comparison (code)
2154 enum tree_code code;
2174 /* Return nonzero if CODE is a tree code that represents a truth value. */
2177 truth_value_p (code)
2178 enum tree_code code;
2180 return (TREE_CODE_CLASS (code) == '<'
2181 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2182 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2183 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
2186 /* Return nonzero if two operands are necessarily equal.
2187 If ONLY_CONST is non-zero, only return non-zero for constants.
2188 This function tests whether the operands are indistinguishable;
2189 it does not test whether they are equal using C's == operation.
2190 The distinction is important for IEEE floating point, because
2191 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2192 (2) two NaNs may be indistinguishable, but NaN!=NaN. */
2195 operand_equal_p (arg0, arg1, only_const)
2199 /* If both types don't have the same signedness, then we can't consider
2200 them equal. We must check this before the STRIP_NOPS calls
2201 because they may change the signedness of the arguments. */
2202 if (TREE_UNSIGNED (TREE_TYPE (arg0)) != TREE_UNSIGNED (TREE_TYPE (arg1)))
2208 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2209 /* This is needed for conversions and for COMPONENT_REF.
2210 Might as well play it safe and always test this. */
2211 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
2212 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
2213 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
2216 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
2217 We don't care about side effects in that case because the SAVE_EXPR
2218 takes care of that for us. In all other cases, two expressions are
2219 equal if they have no side effects. If we have two identical
2220 expressions with side effects that should be treated the same due
2221 to the only side effects being identical SAVE_EXPR's, that will
2222 be detected in the recursive calls below. */
2223 if (arg0 == arg1 && ! only_const
2224 && (TREE_CODE (arg0) == SAVE_EXPR
2225 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
2228 /* Next handle constant cases, those for which we can return 1 even
2229 if ONLY_CONST is set. */
2230 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
2231 switch (TREE_CODE (arg0))
2234 return (! TREE_CONSTANT_OVERFLOW (arg0)
2235 && ! TREE_CONSTANT_OVERFLOW (arg1)
2236 && TREE_INT_CST_LOW (arg0) == TREE_INT_CST_LOW (arg1)
2237 && TREE_INT_CST_HIGH (arg0) == TREE_INT_CST_HIGH (arg1));
2240 return (! TREE_CONSTANT_OVERFLOW (arg0)
2241 && ! TREE_CONSTANT_OVERFLOW (arg1)
2242 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
2243 TREE_REAL_CST (arg1)));
2246 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
2248 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
2252 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
2253 && ! memcmp (TREE_STRING_POINTER (arg0),
2254 TREE_STRING_POINTER (arg1),
2255 TREE_STRING_LENGTH (arg0)));
2258 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
2267 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
2270 /* Two conversions are equal only if signedness and modes match. */
2271 if ((TREE_CODE (arg0) == NOP_EXPR || TREE_CODE (arg0) == CONVERT_EXPR)
2272 && (TREE_UNSIGNED (TREE_TYPE (arg0))
2273 != TREE_UNSIGNED (TREE_TYPE (arg1))))
2276 return operand_equal_p (TREE_OPERAND (arg0, 0),
2277 TREE_OPERAND (arg1, 0), 0);
2281 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0)
2282 && operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1),
2286 /* For commutative ops, allow the other order. */
2287 return ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MULT_EXPR
2288 || TREE_CODE (arg0) == MIN_EXPR || TREE_CODE (arg0) == MAX_EXPR
2289 || TREE_CODE (arg0) == BIT_IOR_EXPR
2290 || TREE_CODE (arg0) == BIT_XOR_EXPR
2291 || TREE_CODE (arg0) == BIT_AND_EXPR
2292 || TREE_CODE (arg0) == NE_EXPR || TREE_CODE (arg0) == EQ_EXPR)
2293 && operand_equal_p (TREE_OPERAND (arg0, 0),
2294 TREE_OPERAND (arg1, 1), 0)
2295 && operand_equal_p (TREE_OPERAND (arg0, 1),
2296 TREE_OPERAND (arg1, 0), 0));
2299 /* If either of the pointer (or reference) expressions we are dereferencing
2300 contain a side effect, these cannot be equal. */
2301 if (TREE_SIDE_EFFECTS (arg0)
2302 || TREE_SIDE_EFFECTS (arg1))
2305 switch (TREE_CODE (arg0))
2308 return operand_equal_p (TREE_OPERAND (arg0, 0),
2309 TREE_OPERAND (arg1, 0), 0);
2313 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2314 TREE_OPERAND (arg1, 0), 0)
2315 && operand_equal_p (TREE_OPERAND (arg0, 1),
2316 TREE_OPERAND (arg1, 1), 0));
2319 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2320 TREE_OPERAND (arg1, 0), 0)
2321 && operand_equal_p (TREE_OPERAND (arg0, 1),
2322 TREE_OPERAND (arg1, 1), 0)
2323 && operand_equal_p (TREE_OPERAND (arg0, 2),
2324 TREE_OPERAND (arg1, 2), 0));
2330 if (TREE_CODE (arg0) == RTL_EXPR)
2331 return rtx_equal_p (RTL_EXPR_RTL (arg0), RTL_EXPR_RTL (arg1));
2339 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2340 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2342 When in doubt, return 0. */
2345 operand_equal_for_comparison_p (arg0, arg1, other)
2349 int unsignedp1, unsignedpo;
2350 tree primarg0, primarg1, primother;
2351 unsigned correct_width;
2353 if (operand_equal_p (arg0, arg1, 0))
2356 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
2357 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
2360 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2361 and see if the inner values are the same. This removes any
2362 signedness comparison, which doesn't matter here. */
2363 primarg0 = arg0, primarg1 = arg1;
2364 STRIP_NOPS (primarg0); STRIP_NOPS (primarg1);
2365 if (operand_equal_p (primarg0, primarg1, 0))
2368 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2369 actual comparison operand, ARG0.
2371 First throw away any conversions to wider types
2372 already present in the operands. */
2374 primarg1 = get_narrower (arg1, &unsignedp1);
2375 primother = get_narrower (other, &unsignedpo);
2377 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
2378 if (unsignedp1 == unsignedpo
2379 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
2380 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
2382 tree type = TREE_TYPE (arg0);
2384 /* Make sure shorter operand is extended the right way
2385 to match the longer operand. */
2386 primarg1 = convert (signed_or_unsigned_type (unsignedp1,
2387 TREE_TYPE (primarg1)),
2390 if (operand_equal_p (arg0, convert (type, primarg1), 0))
2397 /* See if ARG is an expression that is either a comparison or is performing
2398 arithmetic on comparisons. The comparisons must only be comparing
2399 two different values, which will be stored in *CVAL1 and *CVAL2; if
2400 they are non-zero it means that some operands have already been found.
2401 No variables may be used anywhere else in the expression except in the
2402 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2403 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2405 If this is true, return 1. Otherwise, return zero. */
2408 twoval_comparison_p (arg, cval1, cval2, save_p)
2410 tree *cval1, *cval2;
2413 enum tree_code code = TREE_CODE (arg);
2414 char class = TREE_CODE_CLASS (code);
2416 /* We can handle some of the 'e' cases here. */
2417 if (class == 'e' && code == TRUTH_NOT_EXPR)
2419 else if (class == 'e'
2420 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
2421 || code == COMPOUND_EXPR))
2424 else if (class == 'e' && code == SAVE_EXPR && SAVE_EXPR_RTL (arg) == 0
2425 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
2427 /* If we've already found a CVAL1 or CVAL2, this expression is
2428 two complex to handle. */
2429 if (*cval1 || *cval2)
2439 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
2442 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
2443 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2444 cval1, cval2, save_p));
2450 if (code == COND_EXPR)
2451 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
2452 cval1, cval2, save_p)
2453 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2454 cval1, cval2, save_p)
2455 && twoval_comparison_p (TREE_OPERAND (arg, 2),
2456 cval1, cval2, save_p));
2460 /* First see if we can handle the first operand, then the second. For
2461 the second operand, we know *CVAL1 can't be zero. It must be that
2462 one side of the comparison is each of the values; test for the
2463 case where this isn't true by failing if the two operands
2466 if (operand_equal_p (TREE_OPERAND (arg, 0),
2467 TREE_OPERAND (arg, 1), 0))
2471 *cval1 = TREE_OPERAND (arg, 0);
2472 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
2474 else if (*cval2 == 0)
2475 *cval2 = TREE_OPERAND (arg, 0);
2476 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
2481 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
2483 else if (*cval2 == 0)
2484 *cval2 = TREE_OPERAND (arg, 1);
2485 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
2497 /* ARG is a tree that is known to contain just arithmetic operations and
2498 comparisons. Evaluate the operations in the tree substituting NEW0 for
2499 any occurrence of OLD0 as an operand of a comparison and likewise for
2503 eval_subst (arg, old0, new0, old1, new1)
2505 tree old0, new0, old1, new1;
2507 tree type = TREE_TYPE (arg);
2508 enum tree_code code = TREE_CODE (arg);
2509 char class = TREE_CODE_CLASS (code);
2511 /* We can handle some of the 'e' cases here. */
2512 if (class == 'e' && code == TRUTH_NOT_EXPR)
2514 else if (class == 'e'
2515 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2521 return fold (build1 (code, type,
2522 eval_subst (TREE_OPERAND (arg, 0),
2523 old0, new0, old1, new1)));
2526 return fold (build (code, type,
2527 eval_subst (TREE_OPERAND (arg, 0),
2528 old0, new0, old1, new1),
2529 eval_subst (TREE_OPERAND (arg, 1),
2530 old0, new0, old1, new1)));
2536 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
2539 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
2542 return fold (build (code, type,
2543 eval_subst (TREE_OPERAND (arg, 0),
2544 old0, new0, old1, new1),
2545 eval_subst (TREE_OPERAND (arg, 1),
2546 old0, new0, old1, new1),
2547 eval_subst (TREE_OPERAND (arg, 2),
2548 old0, new0, old1, new1)));
2552 /* fall through - ??? */
2556 tree arg0 = TREE_OPERAND (arg, 0);
2557 tree arg1 = TREE_OPERAND (arg, 1);
2559 /* We need to check both for exact equality and tree equality. The
2560 former will be true if the operand has a side-effect. In that
2561 case, we know the operand occurred exactly once. */
2563 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
2565 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
2568 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
2570 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
2573 return fold (build (code, type, arg0, arg1));
2581 /* Return a tree for the case when the result of an expression is RESULT
2582 converted to TYPE and OMITTED was previously an operand of the expression
2583 but is now not needed (e.g., we folded OMITTED * 0).
2585 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2586 the conversion of RESULT to TYPE. */
2589 omit_one_operand (type, result, omitted)
2590 tree type, result, omitted;
2592 tree t = convert (type, result);
2594 if (TREE_SIDE_EFFECTS (omitted))
2595 return build (COMPOUND_EXPR, type, omitted, t);
2597 return non_lvalue (t);
2600 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2603 pedantic_omit_one_operand (type, result, omitted)
2604 tree type, result, omitted;
2606 tree t = convert (type, result);
2608 if (TREE_SIDE_EFFECTS (omitted))
2609 return build (COMPOUND_EXPR, type, omitted, t);
2611 return pedantic_non_lvalue (t);
2616 /* Return a simplified tree node for the truth-negation of ARG. This
2617 never alters ARG itself. We assume that ARG is an operation that
2618 returns a truth value (0 or 1). */
2621 invert_truthvalue (arg)
2624 tree type = TREE_TYPE (arg);
2625 enum tree_code code = TREE_CODE (arg);
2627 if (code == ERROR_MARK)
2630 /* If this is a comparison, we can simply invert it, except for
2631 floating-point non-equality comparisons, in which case we just
2632 enclose a TRUTH_NOT_EXPR around what we have. */
2634 if (TREE_CODE_CLASS (code) == '<')
2636 if (FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg, 0)))
2637 && !flag_fast_math && code != NE_EXPR && code != EQ_EXPR)
2638 return build1 (TRUTH_NOT_EXPR, type, arg);
2640 return build (invert_tree_comparison (code), type,
2641 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
2647 return convert (type, build_int_2 (TREE_INT_CST_LOW (arg) == 0
2648 && TREE_INT_CST_HIGH (arg) == 0, 0));
2650 case TRUTH_AND_EXPR:
2651 return build (TRUTH_OR_EXPR, type,
2652 invert_truthvalue (TREE_OPERAND (arg, 0)),
2653 invert_truthvalue (TREE_OPERAND (arg, 1)));
2656 return build (TRUTH_AND_EXPR, type,
2657 invert_truthvalue (TREE_OPERAND (arg, 0)),
2658 invert_truthvalue (TREE_OPERAND (arg, 1)));
2660 case TRUTH_XOR_EXPR:
2661 /* Here we can invert either operand. We invert the first operand
2662 unless the second operand is a TRUTH_NOT_EXPR in which case our
2663 result is the XOR of the first operand with the inside of the
2664 negation of the second operand. */
2666 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
2667 return build (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
2668 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
2670 return build (TRUTH_XOR_EXPR, type,
2671 invert_truthvalue (TREE_OPERAND (arg, 0)),
2672 TREE_OPERAND (arg, 1));
2674 case TRUTH_ANDIF_EXPR:
2675 return build (TRUTH_ORIF_EXPR, type,
2676 invert_truthvalue (TREE_OPERAND (arg, 0)),
2677 invert_truthvalue (TREE_OPERAND (arg, 1)));
2679 case TRUTH_ORIF_EXPR:
2680 return build (TRUTH_ANDIF_EXPR, type,
2681 invert_truthvalue (TREE_OPERAND (arg, 0)),
2682 invert_truthvalue (TREE_OPERAND (arg, 1)));
2684 case TRUTH_NOT_EXPR:
2685 return TREE_OPERAND (arg, 0);
2688 return build (COND_EXPR, type, TREE_OPERAND (arg, 0),
2689 invert_truthvalue (TREE_OPERAND (arg, 1)),
2690 invert_truthvalue (TREE_OPERAND (arg, 2)));
2693 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
2694 invert_truthvalue (TREE_OPERAND (arg, 1)));
2696 case WITH_RECORD_EXPR:
2697 return build (WITH_RECORD_EXPR, type,
2698 invert_truthvalue (TREE_OPERAND (arg, 0)),
2699 TREE_OPERAND (arg, 1));
2701 case NON_LVALUE_EXPR:
2702 return invert_truthvalue (TREE_OPERAND (arg, 0));
2707 return build1 (TREE_CODE (arg), type,
2708 invert_truthvalue (TREE_OPERAND (arg, 0)));
2711 if (!integer_onep (TREE_OPERAND (arg, 1)))
2713 return build (EQ_EXPR, type, arg, convert (type, integer_zero_node));
2716 return build1 (TRUTH_NOT_EXPR, type, arg);
2718 case CLEANUP_POINT_EXPR:
2719 return build1 (CLEANUP_POINT_EXPR, type,
2720 invert_truthvalue (TREE_OPERAND (arg, 0)));
2725 if (TREE_CODE (TREE_TYPE (arg)) != BOOLEAN_TYPE)
2727 return build1 (TRUTH_NOT_EXPR, type, arg);
2730 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
2731 operands are another bit-wise operation with a common input. If so,
2732 distribute the bit operations to save an operation and possibly two if
2733 constants are involved. For example, convert
2734 (A | B) & (A | C) into A | (B & C)
2735 Further simplification will occur if B and C are constants.
2737 If this optimization cannot be done, 0 will be returned. */
2740 distribute_bit_expr (code, type, arg0, arg1)
2741 enum tree_code code;
2748 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2749 || TREE_CODE (arg0) == code
2750 || (TREE_CODE (arg0) != BIT_AND_EXPR
2751 && TREE_CODE (arg0) != BIT_IOR_EXPR))
2754 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
2756 common = TREE_OPERAND (arg0, 0);
2757 left = TREE_OPERAND (arg0, 1);
2758 right = TREE_OPERAND (arg1, 1);
2760 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
2762 common = TREE_OPERAND (arg0, 0);
2763 left = TREE_OPERAND (arg0, 1);
2764 right = TREE_OPERAND (arg1, 0);
2766 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
2768 common = TREE_OPERAND (arg0, 1);
2769 left = TREE_OPERAND (arg0, 0);
2770 right = TREE_OPERAND (arg1, 1);
2772 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
2774 common = TREE_OPERAND (arg0, 1);
2775 left = TREE_OPERAND (arg0, 0);
2776 right = TREE_OPERAND (arg1, 0);
2781 return fold (build (TREE_CODE (arg0), type, common,
2782 fold (build (code, type, left, right))));
2785 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
2786 starting at BITPOS. The field is unsigned if UNSIGNEDP is non-zero. */
2789 make_bit_field_ref (inner, type, bitsize, bitpos, unsignedp)
2792 int bitsize, bitpos;
2795 tree result = build (BIT_FIELD_REF, type, inner,
2796 size_int (bitsize), bitsize_int (bitpos, 0L));
2798 TREE_UNSIGNED (result) = unsignedp;
2803 /* Optimize a bit-field compare.
2805 There are two cases: First is a compare against a constant and the
2806 second is a comparison of two items where the fields are at the same
2807 bit position relative to the start of a chunk (byte, halfword, word)
2808 large enough to contain it. In these cases we can avoid the shift
2809 implicit in bitfield extractions.
2811 For constants, we emit a compare of the shifted constant with the
2812 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
2813 compared. For two fields at the same position, we do the ANDs with the
2814 similar mask and compare the result of the ANDs.
2816 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
2817 COMPARE_TYPE is the type of the comparison, and LHS and RHS
2818 are the left and right operands of the comparison, respectively.
2820 If the optimization described above can be done, we return the resulting
2821 tree. Otherwise we return zero. */
2824 optimize_bit_field_compare (code, compare_type, lhs, rhs)
2825 enum tree_code code;
2829 int lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
2830 tree type = TREE_TYPE (lhs);
2831 tree signed_type, unsigned_type;
2832 int const_p = TREE_CODE (rhs) == INTEGER_CST;
2833 enum machine_mode lmode, rmode, nmode;
2834 int lunsignedp, runsignedp;
2835 int lvolatilep = 0, rvolatilep = 0;
2837 tree linner, rinner = NULL_TREE;
2841 /* Get all the information about the extractions being done. If the bit size
2842 if the same as the size of the underlying object, we aren't doing an
2843 extraction at all and so can do nothing. We also don't want to
2844 do anything if the inner expression is a PLACEHOLDER_EXPR since we
2845 then will no longer be able to replace it. */
2846 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
2847 &lunsignedp, &lvolatilep, &alignment);
2848 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
2849 || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
2854 /* If this is not a constant, we can only do something if bit positions,
2855 sizes, and signedness are the same. */
2856 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
2857 &runsignedp, &rvolatilep, &alignment);
2859 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
2860 || lunsignedp != runsignedp || offset != 0
2861 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
2865 /* See if we can find a mode to refer to this field. We should be able to,
2866 but fail if we can't. */
2867 nmode = get_best_mode (lbitsize, lbitpos,
2868 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
2869 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
2870 TYPE_ALIGN (TREE_TYPE (rinner))),
2871 word_mode, lvolatilep || rvolatilep);
2872 if (nmode == VOIDmode)
2875 /* Set signed and unsigned types of the precision of this mode for the
2877 signed_type = type_for_mode (nmode, 0);
2878 unsigned_type = type_for_mode (nmode, 1);
2880 /* Compute the bit position and size for the new reference and our offset
2881 within it. If the new reference is the same size as the original, we
2882 won't optimize anything, so return zero. */
2883 nbitsize = GET_MODE_BITSIZE (nmode);
2884 nbitpos = lbitpos & ~ (nbitsize - 1);
2886 if (nbitsize == lbitsize)
2889 if (BYTES_BIG_ENDIAN)
2890 lbitpos = nbitsize - 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 (nbitsize - lbitsize), 0);
2898 mask = const_binop (RSHIFT_EXPR, mask,
2899 size_int (nbitsize - 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 nbitsize, nbitpos, 1),
2909 build (BIT_AND_EXPR, unsigned_type,
2910 make_bit_field_ref (rinner, unsigned_type,
2911 nbitsize, nbitpos, 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, nbitsize, nbitpos, 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. Avoid doing this if the RHS is a floating-point
3857 comparison since those can trap. */
3859 if (BRANCH_COST >= 2
3860 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
3861 && simple_operand_p (rl_arg)
3862 && simple_operand_p (rr_arg))
3863 return build (code, truth_type, lhs, rhs);
3865 /* See if the comparisons can be merged. Then get all the parameters for
3868 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
3869 || (rcode != EQ_EXPR && rcode != NE_EXPR))
3873 ll_inner = decode_field_reference (ll_arg,
3874 &ll_bitsize, &ll_bitpos, &ll_mode,
3875 &ll_unsignedp, &volatilep, &ll_mask,
3877 lr_inner = decode_field_reference (lr_arg,
3878 &lr_bitsize, &lr_bitpos, &lr_mode,
3879 &lr_unsignedp, &volatilep, &lr_mask,
3881 rl_inner = decode_field_reference (rl_arg,
3882 &rl_bitsize, &rl_bitpos, &rl_mode,
3883 &rl_unsignedp, &volatilep, &rl_mask,
3885 rr_inner = decode_field_reference (rr_arg,
3886 &rr_bitsize, &rr_bitpos, &rr_mode,
3887 &rr_unsignedp, &volatilep, &rr_mask,
3890 /* It must be true that the inner operation on the lhs of each
3891 comparison must be the same if we are to be able to do anything.
3892 Then see if we have constants. If not, the same must be true for
3894 if (volatilep || ll_inner == 0 || rl_inner == 0
3895 || ! operand_equal_p (ll_inner, rl_inner, 0))
3898 if (TREE_CODE (lr_arg) == INTEGER_CST
3899 && TREE_CODE (rr_arg) == INTEGER_CST)
3900 l_const = lr_arg, r_const = rr_arg;
3901 else if (lr_inner == 0 || rr_inner == 0
3902 || ! operand_equal_p (lr_inner, rr_inner, 0))
3905 l_const = r_const = 0;
3907 /* If either comparison code is not correct for our logical operation,
3908 fail. However, we can convert a one-bit comparison against zero into
3909 the opposite comparison against that bit being set in the field. */
3911 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
3912 if (lcode != wanted_code)
3914 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
3916 /* Make the left operand unsigned, since we are only interested
3917 in the value of one bit. Otherwise we are doing the wrong
3926 /* This is analogous to the code for l_const above. */
3927 if (rcode != wanted_code)
3929 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
3938 /* See if we can find a mode that contains both fields being compared on
3939 the left. If we can't, fail. Otherwise, update all constants and masks
3940 to be relative to a field of that size. */
3941 first_bit = MIN (ll_bitpos, rl_bitpos);
3942 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
3943 lnmode = get_best_mode (end_bit - first_bit, first_bit,
3944 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
3946 if (lnmode == VOIDmode)
3949 lnbitsize = GET_MODE_BITSIZE (lnmode);
3950 lnbitpos = first_bit & ~ (lnbitsize - 1);
3951 lntype = type_for_size (lnbitsize, 1);
3952 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
3954 if (BYTES_BIG_ENDIAN)
3956 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
3957 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
3960 ll_mask = const_binop (LSHIFT_EXPR, convert (lntype, ll_mask),
3961 size_int (xll_bitpos), 0);
3962 rl_mask = const_binop (LSHIFT_EXPR, convert (lntype, rl_mask),
3963 size_int (xrl_bitpos), 0);
3967 l_const = convert (lntype, l_const);
3968 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
3969 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
3970 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
3971 fold (build1 (BIT_NOT_EXPR,
3975 warning ("comparison is always %d", wanted_code == NE_EXPR);
3977 return convert (truth_type,
3978 wanted_code == NE_EXPR
3979 ? integer_one_node : integer_zero_node);
3984 r_const = convert (lntype, r_const);
3985 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
3986 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
3987 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
3988 fold (build1 (BIT_NOT_EXPR,
3992 warning ("comparison is always %d", wanted_code == NE_EXPR);
3994 return convert (truth_type,
3995 wanted_code == NE_EXPR
3996 ? integer_one_node : integer_zero_node);
4000 /* If the right sides are not constant, do the same for it. Also,
4001 disallow this optimization if a size or signedness mismatch occurs
4002 between the left and right sides. */
4005 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
4006 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
4007 /* Make sure the two fields on the right
4008 correspond to the left without being swapped. */
4009 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
4012 first_bit = MIN (lr_bitpos, rr_bitpos);
4013 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
4014 rnmode = get_best_mode (end_bit - first_bit, first_bit,
4015 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
4017 if (rnmode == VOIDmode)
4020 rnbitsize = GET_MODE_BITSIZE (rnmode);
4021 rnbitpos = first_bit & ~ (rnbitsize - 1);
4022 rntype = type_for_size (rnbitsize, 1);
4023 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
4025 if (BYTES_BIG_ENDIAN)
4027 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
4028 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
4031 lr_mask = const_binop (LSHIFT_EXPR, convert (rntype, lr_mask),
4032 size_int (xlr_bitpos), 0);
4033 rr_mask = const_binop (LSHIFT_EXPR, convert (rntype, rr_mask),
4034 size_int (xrr_bitpos), 0);
4036 /* Make a mask that corresponds to both fields being compared.
4037 Do this for both items being compared. If the operands are the
4038 same size and the bits being compared are in the same position
4039 then we can do this by masking both and comparing the masked
4041 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4042 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
4043 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
4045 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4046 ll_unsignedp || rl_unsignedp);
4047 if (! all_ones_mask_p (ll_mask, lnbitsize))
4048 lhs = build (BIT_AND_EXPR, lntype, lhs, ll_mask);
4050 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
4051 lr_unsignedp || rr_unsignedp);
4052 if (! all_ones_mask_p (lr_mask, rnbitsize))
4053 rhs = build (BIT_AND_EXPR, rntype, rhs, lr_mask);
4055 return build (wanted_code, truth_type, lhs, rhs);
4058 /* There is still another way we can do something: If both pairs of
4059 fields being compared are adjacent, we may be able to make a wider
4060 field containing them both.
4062 Note that we still must mask the lhs/rhs expressions. Furthermore,
4063 the mask must be shifted to account for the shift done by
4064 make_bit_field_ref. */
4065 if ((ll_bitsize + ll_bitpos == rl_bitpos
4066 && lr_bitsize + lr_bitpos == rr_bitpos)
4067 || (ll_bitpos == rl_bitpos + rl_bitsize
4068 && lr_bitpos == rr_bitpos + rr_bitsize))
4072 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
4073 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
4074 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
4075 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
4077 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
4078 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
4079 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
4080 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
4082 /* Convert to the smaller type before masking out unwanted bits. */
4084 if (lntype != rntype)
4086 if (lnbitsize > rnbitsize)
4088 lhs = convert (rntype, lhs);
4089 ll_mask = convert (rntype, ll_mask);
4092 else if (lnbitsize < rnbitsize)
4094 rhs = convert (lntype, rhs);
4095 lr_mask = convert (lntype, lr_mask);
4100 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
4101 lhs = build (BIT_AND_EXPR, type, lhs, ll_mask);
4103 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
4104 rhs = build (BIT_AND_EXPR, type, rhs, lr_mask);
4106 return build (wanted_code, truth_type, lhs, rhs);
4112 /* Handle the case of comparisons with constants. If there is something in
4113 common between the masks, those bits of the constants must be the same.
4114 If not, the condition is always false. Test for this to avoid generating
4115 incorrect code below. */
4116 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
4117 if (! integer_zerop (result)
4118 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
4119 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
4121 if (wanted_code == NE_EXPR)
4123 warning ("`or' of unmatched not-equal tests is always 1");
4124 return convert (truth_type, integer_one_node);
4128 warning ("`and' of mutually exclusive equal-tests is always 0");
4129 return convert (truth_type, integer_zero_node);
4133 /* Construct the expression we will return. First get the component
4134 reference we will make. Unless the mask is all ones the width of
4135 that field, perform the mask operation. Then compare with the
4137 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4138 ll_unsignedp || rl_unsignedp);
4140 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4141 if (! all_ones_mask_p (ll_mask, lnbitsize))
4142 result = build (BIT_AND_EXPR, lntype, result, ll_mask);
4144 return build (wanted_code, truth_type, result,
4145 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
4148 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
4152 optimize_minmax_comparison (t)
4155 tree type = TREE_TYPE (t);
4156 tree arg0 = TREE_OPERAND (t, 0);
4157 enum tree_code op_code;
4158 tree comp_const = TREE_OPERAND (t, 1);
4160 int consts_equal, consts_lt;
4163 STRIP_SIGN_NOPS (arg0);
4165 op_code = TREE_CODE (arg0);
4166 minmax_const = TREE_OPERAND (arg0, 1);
4167 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
4168 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
4169 inner = TREE_OPERAND (arg0, 0);
4171 /* If something does not permit us to optimize, return the original tree. */
4172 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
4173 || TREE_CODE (comp_const) != INTEGER_CST
4174 || TREE_CONSTANT_OVERFLOW (comp_const)
4175 || TREE_CODE (minmax_const) != INTEGER_CST
4176 || TREE_CONSTANT_OVERFLOW (minmax_const))
4179 /* Now handle all the various comparison codes. We only handle EQ_EXPR
4180 and GT_EXPR, doing the rest with recursive calls using logical
4182 switch (TREE_CODE (t))
4184 case NE_EXPR: case LT_EXPR: case LE_EXPR:
4186 invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t)));
4190 fold (build (TRUTH_ORIF_EXPR, type,
4191 optimize_minmax_comparison
4192 (build (EQ_EXPR, type, arg0, comp_const)),
4193 optimize_minmax_comparison
4194 (build (GT_EXPR, type, arg0, comp_const))));
4197 if (op_code == MAX_EXPR && consts_equal)
4198 /* MAX (X, 0) == 0 -> X <= 0 */
4199 return fold (build (LE_EXPR, type, inner, comp_const));
4201 else if (op_code == MAX_EXPR && consts_lt)
4202 /* MAX (X, 0) == 5 -> X == 5 */
4203 return fold (build (EQ_EXPR, type, inner, comp_const));
4205 else if (op_code == MAX_EXPR)
4206 /* MAX (X, 0) == -1 -> false */
4207 return omit_one_operand (type, integer_zero_node, inner);
4209 else if (consts_equal)
4210 /* MIN (X, 0) == 0 -> X >= 0 */
4211 return fold (build (GE_EXPR, type, inner, comp_const));
4214 /* MIN (X, 0) == 5 -> false */
4215 return omit_one_operand (type, integer_zero_node, inner);
4218 /* MIN (X, 0) == -1 -> X == -1 */
4219 return fold (build (EQ_EXPR, type, inner, comp_const));
4222 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
4223 /* MAX (X, 0) > 0 -> X > 0
4224 MAX (X, 0) > 5 -> X > 5 */
4225 return fold (build (GT_EXPR, type, inner, comp_const));
4227 else if (op_code == MAX_EXPR)
4228 /* MAX (X, 0) > -1 -> true */
4229 return omit_one_operand (type, integer_one_node, inner);
4231 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
4232 /* MIN (X, 0) > 0 -> false
4233 MIN (X, 0) > 5 -> false */
4234 return omit_one_operand (type, integer_zero_node, inner);
4237 /* MIN (X, 0) > -1 -> X > -1 */
4238 return fold (build (GT_EXPR, type, inner, comp_const));
4245 /* T is an integer expression that is being multiplied, divided, or taken a
4246 modulus (CODE says which and what kind of divide or modulus) by a
4247 constant C. See if we can eliminate that operation by folding it with
4248 other operations already in T. WIDE_TYPE, if non-null, is a type that
4249 should be used for the computation if wider than our type.
4251 For example, if we are dividing (X * 8) + (Y + 16) by 4, we can return
4252 (X * 2) + (Y + 4). We also canonicalize (X + 7) * 4 into X * 4 + 28
4253 in the hope that either the machine has a multiply-accumulate insn
4254 or that this is part of an addressing calculation.
4256 If we return a non-null expression, it is an equivalent form of the
4257 original computation, but need not be in the original type. */
4260 extract_muldiv (t, c, code, wide_type)
4263 enum tree_code code;
4266 tree type = TREE_TYPE (t);
4267 enum tree_code tcode = TREE_CODE (t);
4268 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
4269 > GET_MODE_SIZE (TYPE_MODE (type)))
4270 ? wide_type : type);
4272 int same_p = tcode == code;
4275 /* Don't deal with constants of zero here; they confuse the code below. */
4276 if (integer_zerop (c))
4279 if (TREE_CODE_CLASS (tcode) == '1')
4280 op0 = TREE_OPERAND (t, 0);
4282 if (TREE_CODE_CLASS (tcode) == '2')
4283 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
4285 /* Note that we need not handle conditional operations here since fold
4286 already handles those cases. So just do arithmetic here. */
4290 /* For a constant, we can always simplify if we are a multiply
4291 or (for divide and modulus) if it is a multiple of our constant. */
4292 if (code == MULT_EXPR
4293 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
4294 return const_binop (code, convert (ctype, t), convert (ctype, c), 0);
4297 case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
4299 /* Pass the constant down and see if we can make a simplification. If
4300 we can, replace this expression with the inner simplification for
4301 possible later conversion to our or some other type. */
4302 if (0 != (t1 = extract_muldiv (op0, convert (TREE_TYPE (op0), c), code,
4303 code == MULT_EXPR ? ctype : NULL_TREE)))
4307 case NEGATE_EXPR: case ABS_EXPR:
4308 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4309 return fold (build1 (tcode, ctype, convert (ctype, t1)));
4312 case MIN_EXPR: case MAX_EXPR:
4313 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
4314 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0
4315 && (t2 = extract_muldiv (op1, c, code, wide_type)) != 0)
4317 if (tree_int_cst_sgn (c) < 0)
4318 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
4320 return fold (build (tcode, ctype, convert (ctype, t1),
4321 convert (ctype, t2)));
4325 case WITH_RECORD_EXPR:
4326 if ((t1 = extract_muldiv (TREE_OPERAND (t, 0), c, code, wide_type)) != 0)
4327 return build (WITH_RECORD_EXPR, TREE_TYPE (t1), t1,
4328 TREE_OPERAND (t, 1));
4332 /* If this has not been evaluated and the operand has no side effects,
4333 we can see if we can do something inside it and make a new one.
4334 Note that this test is overly conservative since we can do this
4335 if the only reason it had side effects is that it was another
4336 similar SAVE_EXPR, but that isn't worth bothering with. */
4337 if (SAVE_EXPR_RTL (t) == 0 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0))
4338 && 0 != (t1 = extract_muldiv (TREE_OPERAND (t, 0), c, code,
4340 return save_expr (t1);
4343 case LSHIFT_EXPR: case RSHIFT_EXPR:
4344 /* If the second operand is constant, this is a multiplication
4345 or floor division, by a power of two, so we can treat it that
4346 way unless the multiplier or divisor overflows. */
4347 if (TREE_CODE (op1) == INTEGER_CST
4348 && 0 != (t1 = convert (ctype,
4349 const_binop (LSHIFT_EXPR, size_one_node,
4351 && ! TREE_OVERFLOW (t1))
4352 return extract_muldiv (build (tcode == LSHIFT_EXPR
4353 ? MULT_EXPR : FLOOR_DIV_EXPR,
4354 ctype, convert (ctype, op0), t1),
4355 c, code, wide_type);
4358 case PLUS_EXPR: case MINUS_EXPR:
4359 /* See if we can eliminate the operation on both sides. If we can, we
4360 can return a new PLUS or MINUS. If we can't, the only remaining
4361 cases where we can do anything are if the second operand is a
4363 t1 = extract_muldiv (op0, c, code, wide_type);
4364 t2 = extract_muldiv (op1, c, code, wide_type);
4365 if (t1 != 0 && t2 != 0)
4366 return fold (build (tcode, ctype, convert (ctype, t1),
4367 convert (ctype, t2)));
4369 /* If this was a subtraction, negate OP1 and set it to be an addition.
4370 This simplifies the logic below. */
4371 if (tcode == MINUS_EXPR)
4372 tcode = PLUS_EXPR, op1 = negate_expr (op1);
4374 if (TREE_CODE (op1) != INTEGER_CST)
4377 /* If either OP1 or C are negative, this optimization is not safe for
4378 some of the division and remainder types while for others we need
4379 to change the code. */
4380 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
4382 if (code == CEIL_DIV_EXPR)
4383 code = FLOOR_DIV_EXPR;
4384 else if (code == CEIL_MOD_EXPR)
4385 code = FLOOR_MOD_EXPR;
4386 else if (code == FLOOR_DIV_EXPR)
4387 code = CEIL_DIV_EXPR;
4388 else if (code == FLOOR_MOD_EXPR)
4389 code = CEIL_MOD_EXPR;
4390 else if (code != MULT_EXPR)
4394 /* Now do the operation and verify it doesn't overflow. */
4395 op1 = const_binop (code, convert (ctype, op1), convert (ctype, c), 0);
4396 if (op1 == 0 || TREE_OVERFLOW (op1))
4399 /* If we were able to eliminate our operation from the first side,
4400 apply our operation to the second side and reform the PLUS. */
4401 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
4402 return fold (build (tcode, ctype, convert (ctype, t1), op1));
4404 /* The last case is if we are a multiply. In that case, we can
4405 apply the distributive law to commute the multiply and addition
4406 if the multiplication of the constants doesn't overflow. */
4407 if (code == MULT_EXPR)
4408 return fold (build (tcode, ctype, fold (build (code, ctype,
4409 convert (ctype, op0),
4410 convert (ctype, c))),
4416 /* We have a special case here if we are doing something like
4417 (C * 8) % 4 since we know that's zero. */
4418 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
4419 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
4420 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
4421 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4422 return omit_one_operand (type, integer_zero_node, op0);
4424 /* ... fall through ... */
4426 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
4427 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
4428 /* If we can extract our operation from the LHS, do so and return a
4429 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
4430 do something only if the second operand is a constant. */
4432 && (t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4433 return fold (build (tcode, ctype, convert (ctype, t1),
4434 convert (ctype, op1)));
4435 else if (tcode == MULT_EXPR && code == MULT_EXPR
4436 && (t1 = extract_muldiv (op1, c, code, wide_type)) != 0)
4437 return fold (build (tcode, ctype, convert (ctype, op0),
4438 convert (ctype, t1)));
4439 else if (TREE_CODE (op1) != INTEGER_CST)
4442 /* If these are the same operation types, we can associate them
4443 assuming no overflow. */
4445 && 0 != (t1 = const_binop (MULT_EXPR, convert (ctype, op1),
4446 convert (ctype, c), 0))
4447 && ! TREE_OVERFLOW (t1))
4448 return fold (build (tcode, ctype, convert (ctype, op0), t1));
4450 /* If these operations "cancel" each other, we have the main
4451 optimizations of this pass, which occur when either constant is a
4452 multiple of the other, in which case we replace this with either an
4453 operation or CODE or TCODE. */
4454 if ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
4455 || (tcode == MULT_EXPR
4456 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
4457 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR))
4459 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4460 return fold (build (tcode, ctype, convert (ctype, op0),
4462 const_binop (TRUNC_DIV_EXPR,
4464 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
4465 return fold (build (code, ctype, convert (ctype, op0),
4467 const_binop (TRUNC_DIV_EXPR,
4479 /* If T contains a COMPOUND_EXPR which was inserted merely to evaluate
4480 S, a SAVE_EXPR, return the expression actually being evaluated. Note
4481 that we may sometimes modify the tree. */
4484 strip_compound_expr (t, s)
4488 enum tree_code code = TREE_CODE (t);
4490 /* See if this is the COMPOUND_EXPR we want to eliminate. */
4491 if (code == COMPOUND_EXPR && TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR
4492 && TREE_OPERAND (TREE_OPERAND (t, 0), 0) == s)
4493 return TREE_OPERAND (t, 1);
4495 /* See if this is a COND_EXPR or a simple arithmetic operator. We
4496 don't bother handling any other types. */
4497 else if (code == COND_EXPR)
4499 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4500 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4501 TREE_OPERAND (t, 2) = strip_compound_expr (TREE_OPERAND (t, 2), s);
4503 else if (TREE_CODE_CLASS (code) == '1')
4504 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4505 else if (TREE_CODE_CLASS (code) == '<'
4506 || TREE_CODE_CLASS (code) == '2')
4508 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4509 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4515 /* Return a node which has the indicated constant VALUE (either 0 or
4516 1), and is of the indicated TYPE. */
4519 constant_boolean_node (value, type)
4523 if (type == integer_type_node)
4524 return value ? integer_one_node : integer_zero_node;
4525 else if (TREE_CODE (type) == BOOLEAN_TYPE)
4526 return truthvalue_conversion (value ? integer_one_node :
4530 tree t = build_int_2 (value, 0);
4532 TREE_TYPE (t) = type;
4537 /* Utility function for the following routine, to see how complex a nesting of
4538 COND_EXPRs can be. EXPR is the expression and LIMIT is a count beyond which
4539 we don't care (to avoid spending too much time on complex expressions.). */
4542 count_cond (expr, lim)
4548 if (TREE_CODE (expr) != COND_EXPR)
4553 true = count_cond (TREE_OPERAND (expr, 1), lim - 1);
4554 false = count_cond (TREE_OPERAND (expr, 2), lim - 1 - true);
4555 return MIN (lim, 1 + true + false);
4558 /* Perform constant folding and related simplification of EXPR.
4559 The related simplifications include x*1 => x, x*0 => 0, etc.,
4560 and application of the associative law.
4561 NOP_EXPR conversions may be removed freely (as long as we
4562 are careful not to change the C type of the overall expression)
4563 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
4564 but we can constant-fold them if they have constant operands. */
4570 register tree t = expr;
4571 tree t1 = NULL_TREE;
4573 tree type = TREE_TYPE (expr);
4574 register tree arg0 = NULL_TREE, arg1 = NULL_TREE;
4575 register enum tree_code code = TREE_CODE (t);
4578 /* WINS will be nonzero when the switch is done
4579 if all operands are constant. */
4582 /* Don't try to process an RTL_EXPR since its operands aren't trees.
4583 Likewise for a SAVE_EXPR that's already been evaluated. */
4584 if (code == RTL_EXPR || (code == SAVE_EXPR && SAVE_EXPR_RTL (t)) != 0)
4587 /* Return right away if already constant. */
4588 if (TREE_CONSTANT (t))
4590 if (code == CONST_DECL)
4591 return DECL_INITIAL (t);
4595 #ifdef MAX_INTEGER_COMPUTATION_MODE
4596 check_max_integer_computation_mode (expr);
4599 kind = TREE_CODE_CLASS (code);
4600 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
4604 /* Special case for conversion ops that can have fixed point args. */
4605 arg0 = TREE_OPERAND (t, 0);
4607 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
4609 STRIP_SIGN_NOPS (arg0);
4611 if (arg0 != 0 && TREE_CODE (arg0) == COMPLEX_CST)
4612 subop = TREE_REALPART (arg0);
4616 if (subop != 0 && TREE_CODE (subop) != INTEGER_CST
4617 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
4618 && TREE_CODE (subop) != REAL_CST
4619 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
4621 /* Note that TREE_CONSTANT isn't enough:
4622 static var addresses are constant but we can't
4623 do arithmetic on them. */
4626 else if (kind == 'e' || kind == '<'
4627 || kind == '1' || kind == '2' || kind == 'r')
4629 register int len = tree_code_length[(int) code];
4631 for (i = 0; i < len; i++)
4633 tree op = TREE_OPERAND (t, i);
4637 continue; /* Valid for CALL_EXPR, at least. */
4639 if (kind == '<' || code == RSHIFT_EXPR)
4641 /* Signedness matters here. Perhaps we can refine this
4643 STRIP_SIGN_NOPS (op);
4647 /* Strip any conversions that don't change the mode. */
4651 if (TREE_CODE (op) == COMPLEX_CST)
4652 subop = TREE_REALPART (op);
4656 if (TREE_CODE (subop) != INTEGER_CST
4657 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
4658 && TREE_CODE (subop) != REAL_CST
4659 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
4661 /* Note that TREE_CONSTANT isn't enough:
4662 static var addresses are constant but we can't
4663 do arithmetic on them. */
4673 /* If this is a commutative operation, and ARG0 is a constant, move it
4674 to ARG1 to reduce the number of tests below. */
4675 if ((code == PLUS_EXPR || code == MULT_EXPR || code == MIN_EXPR
4676 || code == MAX_EXPR || code == BIT_IOR_EXPR || code == BIT_XOR_EXPR
4677 || code == BIT_AND_EXPR)
4678 && (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST))
4680 tem = arg0; arg0 = arg1; arg1 = tem;
4682 tem = TREE_OPERAND (t, 0); TREE_OPERAND (t, 0) = TREE_OPERAND (t, 1);
4683 TREE_OPERAND (t, 1) = tem;
4686 /* Now WINS is set as described above,
4687 ARG0 is the first operand of EXPR,
4688 and ARG1 is the second operand (if it has more than one operand).
4690 First check for cases where an arithmetic operation is applied to a
4691 compound, conditional, or comparison operation. Push the arithmetic
4692 operation inside the compound or conditional to see if any folding
4693 can then be done. Convert comparison to conditional for this purpose.
4694 The also optimizes non-constant cases that used to be done in
4697 Before we do that, see if this is a BIT_AND_EXPR or a BIT_OR_EXPR,
4698 one of the operands is a comparison and the other is a comparison, a
4699 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
4700 code below would make the expression more complex. Change it to a
4701 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
4702 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
4704 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
4705 || code == EQ_EXPR || code == NE_EXPR)
4706 && ((truth_value_p (TREE_CODE (arg0))
4707 && (truth_value_p (TREE_CODE (arg1))
4708 || (TREE_CODE (arg1) == BIT_AND_EXPR
4709 && integer_onep (TREE_OPERAND (arg1, 1)))))
4710 || (truth_value_p (TREE_CODE (arg1))
4711 && (truth_value_p (TREE_CODE (arg0))
4712 || (TREE_CODE (arg0) == BIT_AND_EXPR
4713 && integer_onep (TREE_OPERAND (arg0, 1)))))))
4715 t = fold (build (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
4716 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
4720 if (code == EQ_EXPR)
4721 t = invert_truthvalue (t);
4726 if (TREE_CODE_CLASS (code) == '1')
4728 if (TREE_CODE (arg0) == COMPOUND_EXPR)
4729 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
4730 fold (build1 (code, type, TREE_OPERAND (arg0, 1))));
4731 else if (TREE_CODE (arg0) == COND_EXPR)
4733 t = fold (build (COND_EXPR, type, TREE_OPERAND (arg0, 0),
4734 fold (build1 (code, type, TREE_OPERAND (arg0, 1))),
4735 fold (build1 (code, type, TREE_OPERAND (arg0, 2)))));
4737 /* If this was a conversion, and all we did was to move into
4738 inside the COND_EXPR, bring it back out. But leave it if
4739 it is a conversion from integer to integer and the
4740 result precision is no wider than a word since such a
4741 conversion is cheap and may be optimized away by combine,
4742 while it couldn't if it were outside the COND_EXPR. Then return
4743 so we don't get into an infinite recursion loop taking the
4744 conversion out and then back in. */
4746 if ((code == NOP_EXPR || code == CONVERT_EXPR
4747 || code == NON_LVALUE_EXPR)
4748 && TREE_CODE (t) == COND_EXPR
4749 && TREE_CODE (TREE_OPERAND (t, 1)) == code
4750 && TREE_CODE (TREE_OPERAND (t, 2)) == code
4751 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))
4752 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 2), 0)))
4753 && ! (INTEGRAL_TYPE_P (TREE_TYPE (t))
4755 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))))
4756 && TYPE_PRECISION (TREE_TYPE (t)) <= BITS_PER_WORD))
4757 t = build1 (code, type,
4759 TREE_TYPE (TREE_OPERAND
4760 (TREE_OPERAND (t, 1), 0)),
4761 TREE_OPERAND (t, 0),
4762 TREE_OPERAND (TREE_OPERAND (t, 1), 0),
4763 TREE_OPERAND (TREE_OPERAND (t, 2), 0)));
4766 else if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<')
4767 return fold (build (COND_EXPR, type, arg0,
4768 fold (build1 (code, type, integer_one_node)),
4769 fold (build1 (code, type, integer_zero_node))));
4771 else if (TREE_CODE_CLASS (code) == '2'
4772 || TREE_CODE_CLASS (code) == '<')
4774 if (TREE_CODE (arg1) == COMPOUND_EXPR)
4775 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
4776 fold (build (code, type,
4777 arg0, TREE_OPERAND (arg1, 1))));
4778 else if ((TREE_CODE (arg1) == COND_EXPR
4779 || (TREE_CODE_CLASS (TREE_CODE (arg1)) == '<'
4780 && TREE_CODE_CLASS (code) != '<'))
4781 && (TREE_CODE (arg0) != COND_EXPR
4782 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
4783 && (! TREE_SIDE_EFFECTS (arg0)
4784 || (global_bindings_p () == 0
4785 && ! contains_placeholder_p (arg0))))
4787 tree test, true_value, false_value;
4788 tree lhs = 0, rhs = 0;
4790 if (TREE_CODE (arg1) == COND_EXPR)
4792 test = TREE_OPERAND (arg1, 0);
4793 true_value = TREE_OPERAND (arg1, 1);
4794 false_value = TREE_OPERAND (arg1, 2);
4798 tree testtype = TREE_TYPE (arg1);
4800 true_value = convert (testtype, integer_one_node);
4801 false_value = convert (testtype, integer_zero_node);
4804 /* If ARG0 is complex we want to make sure we only evaluate
4805 it once. Though this is only required if it is volatile, it
4806 might be more efficient even if it is not. However, if we
4807 succeed in folding one part to a constant, we do not need
4808 to make this SAVE_EXPR. Since we do this optimization
4809 primarily to see if we do end up with constant and this
4810 SAVE_EXPR interferes with later optimizations, suppressing
4811 it when we can is important.
4813 If we are not in a function, we can't make a SAVE_EXPR, so don't
4814 try to do so. Don't try to see if the result is a constant
4815 if an arm is a COND_EXPR since we get exponential behavior
4818 if (TREE_CODE (arg0) != SAVE_EXPR && ! TREE_CONSTANT (arg0)
4819 && global_bindings_p () == 0
4820 && ((TREE_CODE (arg0) != VAR_DECL
4821 && TREE_CODE (arg0) != PARM_DECL)
4822 || TREE_SIDE_EFFECTS (arg0)))
4824 if (TREE_CODE (true_value) != COND_EXPR)
4825 lhs = fold (build (code, type, arg0, true_value));
4827 if (TREE_CODE (false_value) != COND_EXPR)
4828 rhs = fold (build (code, type, arg0, false_value));
4830 if ((lhs == 0 || ! TREE_CONSTANT (lhs))
4831 && (rhs == 0 || !TREE_CONSTANT (rhs)))
4832 arg0 = save_expr (arg0), lhs = rhs = 0;
4836 lhs = fold (build (code, type, arg0, true_value));
4838 rhs = fold (build (code, type, arg0, false_value));
4840 test = fold (build (COND_EXPR, type, test, lhs, rhs));
4842 if (TREE_CODE (arg0) == SAVE_EXPR)
4843 return build (COMPOUND_EXPR, type,
4844 convert (void_type_node, arg0),
4845 strip_compound_expr (test, arg0));
4847 return convert (type, test);
4850 else if (TREE_CODE (arg0) == COMPOUND_EXPR)
4851 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
4852 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
4853 else if ((TREE_CODE (arg0) == COND_EXPR
4854 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
4855 && TREE_CODE_CLASS (code) != '<'))
4856 && (TREE_CODE (arg1) != COND_EXPR
4857 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
4858 && (! TREE_SIDE_EFFECTS (arg1)
4859 || (global_bindings_p () == 0
4860 && ! contains_placeholder_p (arg1))))
4862 tree test, true_value, false_value;
4863 tree lhs = 0, rhs = 0;
4865 if (TREE_CODE (arg0) == COND_EXPR)
4867 test = TREE_OPERAND (arg0, 0);
4868 true_value = TREE_OPERAND (arg0, 1);
4869 false_value = TREE_OPERAND (arg0, 2);
4873 tree testtype = TREE_TYPE (arg0);
4875 true_value = convert (testtype, integer_one_node);
4876 false_value = convert (testtype, integer_zero_node);
4879 if (TREE_CODE (arg1) != SAVE_EXPR && ! TREE_CONSTANT (arg0)
4880 && global_bindings_p () == 0
4881 && ((TREE_CODE (arg1) != VAR_DECL
4882 && TREE_CODE (arg1) != PARM_DECL)
4883 || TREE_SIDE_EFFECTS (arg1)))
4885 if (TREE_CODE (true_value) != COND_EXPR)
4886 lhs = fold (build (code, type, true_value, arg1));
4888 if (TREE_CODE (false_value) != COND_EXPR)
4889 rhs = fold (build (code, type, false_value, arg1));
4891 if ((lhs == 0 || ! TREE_CONSTANT (lhs))
4892 && (rhs == 0 || !TREE_CONSTANT (rhs)))
4893 arg1 = save_expr (arg1), lhs = rhs = 0;
4897 lhs = fold (build (code, type, true_value, arg1));
4900 rhs = fold (build (code, type, false_value, arg1));
4902 test = fold (build (COND_EXPR, type, test, lhs, rhs));
4903 if (TREE_CODE (arg1) == SAVE_EXPR)
4904 return build (COMPOUND_EXPR, type,
4905 convert (void_type_node, arg1),
4906 strip_compound_expr (test, arg1));
4908 return convert (type, test);
4911 else if (TREE_CODE_CLASS (code) == '<'
4912 && TREE_CODE (arg0) == COMPOUND_EXPR)
4913 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
4914 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
4915 else if (TREE_CODE_CLASS (code) == '<'
4916 && TREE_CODE (arg1) == COMPOUND_EXPR)
4917 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
4918 fold (build (code, type, arg0, TREE_OPERAND (arg1, 1))));
4930 return fold (DECL_INITIAL (t));
4935 case FIX_TRUNC_EXPR:
4936 /* Other kinds of FIX are not handled properly by fold_convert. */
4938 if (TREE_TYPE (TREE_OPERAND (t, 0)) == TREE_TYPE (t))
4939 return TREE_OPERAND (t, 0);
4941 /* Handle cases of two conversions in a row. */
4942 if (TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
4943 || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR)
4945 tree inside_type = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
4946 tree inter_type = TREE_TYPE (TREE_OPERAND (t, 0));
4947 tree final_type = TREE_TYPE (t);
4948 int inside_int = INTEGRAL_TYPE_P (inside_type);
4949 int inside_ptr = POINTER_TYPE_P (inside_type);
4950 int inside_float = FLOAT_TYPE_P (inside_type);
4951 int inside_prec = TYPE_PRECISION (inside_type);
4952 int inside_unsignedp = TREE_UNSIGNED (inside_type);
4953 int inter_int = INTEGRAL_TYPE_P (inter_type);
4954 int inter_ptr = POINTER_TYPE_P (inter_type);
4955 int inter_float = FLOAT_TYPE_P (inter_type);
4956 int inter_prec = TYPE_PRECISION (inter_type);
4957 int inter_unsignedp = TREE_UNSIGNED (inter_type);
4958 int final_int = INTEGRAL_TYPE_P (final_type);
4959 int final_ptr = POINTER_TYPE_P (final_type);
4960 int final_float = FLOAT_TYPE_P (final_type);
4961 int final_prec = TYPE_PRECISION (final_type);
4962 int final_unsignedp = TREE_UNSIGNED (final_type);
4964 /* In addition to the cases of two conversions in a row
4965 handled below, if we are converting something to its own
4966 type via an object of identical or wider precision, neither
4967 conversion is needed. */
4968 if (inside_type == final_type
4969 && ((inter_int && final_int) || (inter_float && final_float))
4970 && inter_prec >= final_prec)
4971 return TREE_OPERAND (TREE_OPERAND (t, 0), 0);
4973 /* Likewise, if the intermediate and final types are either both
4974 float or both integer, we don't need the middle conversion if
4975 it is wider than the final type and doesn't change the signedness
4976 (for integers). Avoid this if the final type is a pointer
4977 since then we sometimes need the inner conversion. Likewise if
4978 the outer has a precision not equal to the size of its mode. */
4979 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
4980 || (inter_float && inside_float))
4981 && inter_prec >= inside_prec
4982 && (inter_float || inter_unsignedp == inside_unsignedp)
4983 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
4984 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
4986 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
4988 /* If we have a sign-extension of a zero-extended value, we can
4989 replace that by a single zero-extension. */
4990 if (inside_int && inter_int && final_int
4991 && inside_prec < inter_prec && inter_prec < final_prec
4992 && inside_unsignedp && !inter_unsignedp)
4993 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
4995 /* Two conversions in a row are not needed unless:
4996 - some conversion is floating-point (overstrict for now), or
4997 - the intermediate type is narrower than both initial and
4999 - the intermediate type and innermost type differ in signedness,
5000 and the outermost type is wider than the intermediate, or
5001 - the initial type is a pointer type and the precisions of the
5002 intermediate and final types differ, or
5003 - the final type is a pointer type and the precisions of the
5004 initial and intermediate types differ. */
5005 if (! inside_float && ! inter_float && ! final_float
5006 && (inter_prec > inside_prec || inter_prec > final_prec)
5007 && ! (inside_int && inter_int
5008 && inter_unsignedp != inside_unsignedp
5009 && inter_prec < final_prec)
5010 && ((inter_unsignedp && inter_prec > inside_prec)
5011 == (final_unsignedp && final_prec > inter_prec))
5012 && ! (inside_ptr && inter_prec != final_prec)
5013 && ! (final_ptr && inside_prec != inter_prec)
5014 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
5015 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
5017 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5020 if (TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR
5021 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t, 0), 1))
5022 /* Detect assigning a bitfield. */
5023 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) == COMPONENT_REF
5024 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 1))))
5026 /* Don't leave an assignment inside a conversion
5027 unless assigning a bitfield. */
5028 tree prev = TREE_OPERAND (t, 0);
5029 TREE_OPERAND (t, 0) = TREE_OPERAND (prev, 1);
5030 /* First do the assignment, then return converted constant. */
5031 t = build (COMPOUND_EXPR, TREE_TYPE (t), prev, fold (t));
5037 TREE_CONSTANT (t) = TREE_CONSTANT (arg0);
5040 return fold_convert (t, arg0);
5042 #if 0 /* This loses on &"foo"[0]. */
5047 /* Fold an expression like: "foo"[2] */
5048 if (TREE_CODE (arg0) == STRING_CST
5049 && TREE_CODE (arg1) == INTEGER_CST
5050 && !TREE_INT_CST_HIGH (arg1)
5051 && (i = TREE_INT_CST_LOW (arg1)) < TREE_STRING_LENGTH (arg0))
5053 t = build_int_2 (TREE_STRING_POINTER (arg0)[i], 0);
5054 TREE_TYPE (t) = TREE_TYPE (TREE_TYPE (arg0));
5055 force_fit_type (t, 0);
5062 if (TREE_CODE (arg0) == CONSTRUCTOR)
5064 tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0));
5071 TREE_CONSTANT (t) = wins;
5077 if (TREE_CODE (arg0) == INTEGER_CST)
5079 HOST_WIDE_INT low, high;
5080 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
5081 TREE_INT_CST_HIGH (arg0),
5083 t = build_int_2 (low, high);
5084 TREE_TYPE (t) = type;
5086 = (TREE_OVERFLOW (arg0)
5087 | force_fit_type (t, overflow && !TREE_UNSIGNED (type)));
5088 TREE_CONSTANT_OVERFLOW (t)
5089 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
5091 else if (TREE_CODE (arg0) == REAL_CST)
5092 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
5094 else if (TREE_CODE (arg0) == NEGATE_EXPR)
5095 return TREE_OPERAND (arg0, 0);
5097 /* Convert - (a - b) to (b - a) for non-floating-point. */
5098 else if (TREE_CODE (arg0) == MINUS_EXPR
5099 && (! FLOAT_TYPE_P (type) || flag_fast_math))
5100 return build (MINUS_EXPR, type, TREE_OPERAND (arg0, 1),
5101 TREE_OPERAND (arg0, 0));
5108 if (TREE_CODE (arg0) == INTEGER_CST)
5110 if (! TREE_UNSIGNED (type)
5111 && TREE_INT_CST_HIGH (arg0) < 0)
5113 HOST_WIDE_INT low, high;
5114 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
5115 TREE_INT_CST_HIGH (arg0),
5117 t = build_int_2 (low, high);
5118 TREE_TYPE (t) = type;
5120 = (TREE_OVERFLOW (arg0)
5121 | force_fit_type (t, overflow));
5122 TREE_CONSTANT_OVERFLOW (t)
5123 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
5126 else if (TREE_CODE (arg0) == REAL_CST)
5128 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
5129 t = build_real (type,
5130 REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
5133 else if (TREE_CODE (arg0) == ABS_EXPR || TREE_CODE (arg0) == NEGATE_EXPR)
5134 return build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0));
5138 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
5140 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
5141 return build (COMPLEX_EXPR, TREE_TYPE (arg0),
5142 TREE_OPERAND (arg0, 0),
5143 negate_expr (TREE_OPERAND (arg0, 1)));
5144 else if (TREE_CODE (arg0) == COMPLEX_CST)
5145 return build_complex (type, TREE_OPERAND (arg0, 0),
5146 negate_expr (TREE_OPERAND (arg0, 1)));
5147 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
5148 return fold (build (TREE_CODE (arg0), type,
5149 fold (build1 (CONJ_EXPR, type,
5150 TREE_OPERAND (arg0, 0))),
5151 fold (build1 (CONJ_EXPR,
5152 type, TREE_OPERAND (arg0, 1)))));
5153 else if (TREE_CODE (arg0) == CONJ_EXPR)
5154 return TREE_OPERAND (arg0, 0);
5160 t = build_int_2 (~ TREE_INT_CST_LOW (arg0),
5161 ~ TREE_INT_CST_HIGH (arg0));
5162 TREE_TYPE (t) = type;
5163 force_fit_type (t, 0);
5164 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg0);
5165 TREE_CONSTANT_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (arg0);
5167 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
5168 return TREE_OPERAND (arg0, 0);
5172 /* A + (-B) -> A - B */
5173 if (TREE_CODE (arg1) == NEGATE_EXPR)
5174 return fold (build (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5175 /* (-A) + B -> B - A */
5176 if (TREE_CODE (arg0) == NEGATE_EXPR)
5177 return fold (build (MINUS_EXPR, type, arg1, TREE_OPERAND (arg0, 0)));
5178 else if (! FLOAT_TYPE_P (type))
5180 if (integer_zerop (arg1))
5181 return non_lvalue (convert (type, arg0));
5183 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
5184 with a constant, and the two constants have no bits in common,
5185 we should treat this as a BIT_IOR_EXPR since this may produce more
5187 if (TREE_CODE (arg0) == BIT_AND_EXPR
5188 && TREE_CODE (arg1) == BIT_AND_EXPR
5189 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5190 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
5191 && integer_zerop (const_binop (BIT_AND_EXPR,
5192 TREE_OPERAND (arg0, 1),
5193 TREE_OPERAND (arg1, 1), 0)))
5195 code = BIT_IOR_EXPR;
5199 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
5200 (plus (plus (mult) (mult)) (foo)) so that we can
5201 take advantage of the factoring cases below. */
5202 if ((TREE_CODE (arg0) == PLUS_EXPR
5203 && TREE_CODE (arg1) == MULT_EXPR)
5204 || (TREE_CODE (arg1) == PLUS_EXPR
5205 && TREE_CODE (arg0) == MULT_EXPR))
5207 tree parg0, parg1, parg, marg;
5209 if (TREE_CODE (arg0) == PLUS_EXPR)
5210 parg = arg0, marg = arg1;
5212 parg = arg1, marg = arg0;
5213 parg0 = TREE_OPERAND (parg, 0);
5214 parg1 = TREE_OPERAND (parg, 1);
5218 if (TREE_CODE (parg0) == MULT_EXPR
5219 && TREE_CODE (parg1) != MULT_EXPR)
5220 return fold (build (PLUS_EXPR, type,
5221 fold (build (PLUS_EXPR, type, parg0, marg)),
5223 if (TREE_CODE (parg0) != MULT_EXPR
5224 && TREE_CODE (parg1) == MULT_EXPR)
5225 return fold (build (PLUS_EXPR, type,
5226 fold (build (PLUS_EXPR, type, parg1, marg)),
5230 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR)
5232 tree arg00, arg01, arg10, arg11;
5233 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
5235 /* (A * C) + (B * C) -> (A+B) * C.
5236 We are most concerned about the case where C is a constant,
5237 but other combinations show up during loop reduction. Since
5238 it is not difficult, try all four possibilities. */
5240 arg00 = TREE_OPERAND (arg0, 0);
5241 arg01 = TREE_OPERAND (arg0, 1);
5242 arg10 = TREE_OPERAND (arg1, 0);
5243 arg11 = TREE_OPERAND (arg1, 1);
5246 if (operand_equal_p (arg01, arg11, 0))
5247 same = arg01, alt0 = arg00, alt1 = arg10;
5248 else if (operand_equal_p (arg00, arg10, 0))
5249 same = arg00, alt0 = arg01, alt1 = arg11;
5250 else if (operand_equal_p (arg00, arg11, 0))
5251 same = arg00, alt0 = arg01, alt1 = arg10;
5252 else if (operand_equal_p (arg01, arg10, 0))
5253 same = arg01, alt0 = arg00, alt1 = arg11;
5255 /* No identical multiplicands; see if we can find a common
5256 power-of-two factor in non-power-of-two multiplies. This
5257 can help in multi-dimensional array access. */
5258 else if (TREE_CODE (arg01) == INTEGER_CST
5259 && TREE_CODE (arg11) == INTEGER_CST
5260 && TREE_INT_CST_HIGH (arg01) == 0
5261 && TREE_INT_CST_HIGH (arg11) == 0)
5263 HOST_WIDE_INT int01, int11, tmp;
5264 int01 = TREE_INT_CST_LOW (arg01);
5265 int11 = TREE_INT_CST_LOW (arg11);
5267 /* Move min of absolute values to int11. */
5268 if ((int01 >= 0 ? int01 : -int01)
5269 < (int11 >= 0 ? int11 : -int11))
5271 tmp = int01, int01 = int11, int11 = tmp;
5272 alt0 = arg00, arg00 = arg10, arg10 = alt0;
5273 alt0 = arg01, arg01 = arg11, arg11 = alt0;
5276 if (exact_log2 (int11) > 0 && int01 % int11 == 0)
5278 alt0 = fold (build (MULT_EXPR, type, arg00,
5279 build_int_2 (int01 / int11, 0)));
5286 return fold (build (MULT_EXPR, type,
5287 fold (build (PLUS_EXPR, type, alt0, alt1)),
5291 /* In IEEE floating point, x+0 may not equal x. */
5292 else if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
5294 && real_zerop (arg1))
5295 return non_lvalue (convert (type, arg0));
5296 /* x+(-0) equals x, even for IEEE. */
5297 else if (TREE_CODE (arg1) == REAL_CST
5298 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (arg1)))
5299 return non_lvalue (convert (type, arg0));
5302 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
5303 is a rotate of A by C1 bits. */
5304 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
5305 is a rotate of A by B bits. */
5307 register enum tree_code code0, code1;
5308 code0 = TREE_CODE (arg0);
5309 code1 = TREE_CODE (arg1);
5310 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
5311 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
5312 && operand_equal_p (TREE_OPERAND (arg0, 0),
5313 TREE_OPERAND (arg1,0), 0)
5314 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5316 register tree tree01, tree11;
5317 register enum tree_code code01, code11;
5319 tree01 = TREE_OPERAND (arg0, 1);
5320 tree11 = TREE_OPERAND (arg1, 1);
5321 STRIP_NOPS (tree01);
5322 STRIP_NOPS (tree11);
5323 code01 = TREE_CODE (tree01);
5324 code11 = TREE_CODE (tree11);
5325 if (code01 == INTEGER_CST
5326 && code11 == INTEGER_CST
5327 && TREE_INT_CST_HIGH (tree01) == 0
5328 && TREE_INT_CST_HIGH (tree11) == 0
5329 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
5330 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
5331 return build (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
5332 code0 == LSHIFT_EXPR ? tree01 : tree11);
5333 else if (code11 == MINUS_EXPR)
5335 tree tree110, tree111;
5336 tree110 = TREE_OPERAND (tree11, 0);
5337 tree111 = TREE_OPERAND (tree11, 1);
5338 STRIP_NOPS (tree110);
5339 STRIP_NOPS (tree111);
5340 if (TREE_CODE (tree110) == INTEGER_CST
5341 && TREE_INT_CST_HIGH (tree110) == 0
5342 && (TREE_INT_CST_LOW (tree110)
5343 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5344 && operand_equal_p (tree01, tree111, 0))
5345 return build ((code0 == LSHIFT_EXPR
5348 type, TREE_OPERAND (arg0, 0), tree01);
5350 else if (code01 == MINUS_EXPR)
5352 tree tree010, tree011;
5353 tree010 = TREE_OPERAND (tree01, 0);
5354 tree011 = TREE_OPERAND (tree01, 1);
5355 STRIP_NOPS (tree010);
5356 STRIP_NOPS (tree011);
5357 if (TREE_CODE (tree010) == INTEGER_CST
5358 && TREE_INT_CST_HIGH (tree010) == 0
5359 && (TREE_INT_CST_LOW (tree010)
5360 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5361 && operand_equal_p (tree11, tree011, 0))
5362 return build ((code0 != LSHIFT_EXPR
5365 type, TREE_OPERAND (arg0, 0), tree11);
5372 /* In most languages, can't associate operations on floats through
5373 parentheses. Rather than remember where the parentheses were, we
5374 don't associate floats at all. It shouldn't matter much. However,
5375 associating multiplications is only very slightly inaccurate, so do
5376 that if -ffast-math is specified. */
5379 && (! FLOAT_TYPE_P (type)
5380 || (flag_fast_math && code != MULT_EXPR)))
5382 tree var0, con0, lit0, var1, con1, lit1;
5384 /* Split both trees into variables, constants, and literals. Then
5385 associate each group together, the constants with literals,
5386 then the result with variables. This increases the chances of
5387 literals being recombined later and of generating relocatable
5388 expressions for the sum of a constant and literal. */
5389 var0 = split_tree (arg0, code, &con0, &lit0, 0);
5390 var1 = split_tree (arg1, code, &con1, &lit1, code == MINUS_EXPR);
5392 /* Only do something if we found more than two objects. Otherwise,
5393 nothing has changed and we risk infinite recursion. */
5394 if (2 < ((var0 != 0) + (var1 != 0) + (con0 != 0) + (con1 != 0)
5395 + (lit0 != 0) + (lit1 != 0)))
5397 var0 = associate_trees (var0, var1, code, type);
5398 con0 = associate_trees (con0, con1, code, type);
5399 lit0 = associate_trees (lit0, lit1, code, type);
5400 con0 = associate_trees (con0, lit0, code, type);
5401 return convert (type, associate_trees (var0, con0, code, type));
5406 #if defined (REAL_IS_NOT_DOUBLE) && ! defined (REAL_ARITHMETIC)
5407 if (TREE_CODE (arg1) == REAL_CST)
5409 #endif /* REAL_IS_NOT_DOUBLE, and no REAL_ARITHMETIC */
5411 t1 = const_binop (code, arg0, arg1, 0);
5412 if (t1 != NULL_TREE)
5414 /* The return value should always have
5415 the same type as the original expression. */
5416 if (TREE_TYPE (t1) != TREE_TYPE (t))
5417 t1 = convert (TREE_TYPE (t), t1);
5424 /* A - (-B) -> A + B */
5425 if (TREE_CODE (arg1) == NEGATE_EXPR)
5426 return fold (build (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5427 /* (-A) - CST -> (-CST) - A for floating point (what about ints ?) */
5428 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == REAL_CST)
5430 fold (build (MINUS_EXPR, type,
5431 build_real (TREE_TYPE (arg1),
5432 REAL_VALUE_NEGATE (TREE_REAL_CST (arg1))),
5433 TREE_OPERAND (arg0, 0)));
5435 if (! FLOAT_TYPE_P (type))
5437 if (! wins && integer_zerop (arg0))
5438 return negate_expr (arg1);
5439 if (integer_zerop (arg1))
5440 return non_lvalue (convert (type, arg0));
5442 /* (A * C) - (B * C) -> (A-B) * C. Since we are most concerned
5443 about the case where C is a constant, just try one of the
5444 four possibilities. */
5446 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR
5447 && operand_equal_p (TREE_OPERAND (arg0, 1),
5448 TREE_OPERAND (arg1, 1), 0))
5449 return fold (build (MULT_EXPR, type,
5450 fold (build (MINUS_EXPR, type,
5451 TREE_OPERAND (arg0, 0),
5452 TREE_OPERAND (arg1, 0))),
5453 TREE_OPERAND (arg0, 1)));
5456 else if (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
5459 /* Except with IEEE floating point, 0-x equals -x. */
5460 if (! wins && real_zerop (arg0))
5461 return negate_expr (arg1);
5462 /* Except with IEEE floating point, x-0 equals x. */
5463 if (real_zerop (arg1))
5464 return non_lvalue (convert (type, arg0));
5467 /* Fold &x - &x. This can happen from &x.foo - &x.
5468 This is unsafe for certain floats even in non-IEEE formats.
5469 In IEEE, it is unsafe because it does wrong for NaNs.
5470 Also note that operand_equal_p is always false if an operand
5473 if ((! FLOAT_TYPE_P (type) || flag_fast_math)
5474 && operand_equal_p (arg0, arg1, 0))
5475 return convert (type, integer_zero_node);
5480 /* (-A) * (-B) -> A * B */
5481 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR)
5482 return fold (build (MULT_EXPR, type, TREE_OPERAND (arg0, 0),
5483 TREE_OPERAND (arg1, 0)));
5485 if (! FLOAT_TYPE_P (type))
5487 if (integer_zerop (arg1))
5488 return omit_one_operand (type, arg1, arg0);
5489 if (integer_onep (arg1))
5490 return non_lvalue (convert (type, arg0));
5492 /* (a * (1 << b)) is (a << b) */
5493 if (TREE_CODE (arg1) == LSHIFT_EXPR
5494 && integer_onep (TREE_OPERAND (arg1, 0)))
5495 return fold (build (LSHIFT_EXPR, type, arg0,
5496 TREE_OPERAND (arg1, 1)));
5497 if (TREE_CODE (arg0) == LSHIFT_EXPR
5498 && integer_onep (TREE_OPERAND (arg0, 0)))
5499 return fold (build (LSHIFT_EXPR, type, arg1,
5500 TREE_OPERAND (arg0, 1)));
5502 if (TREE_CODE (arg1) == INTEGER_CST
5503 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
5505 return convert (type, tem);
5510 /* x*0 is 0, except for IEEE floating point. */
5511 if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
5513 && real_zerop (arg1))
5514 return omit_one_operand (type, arg1, arg0);
5515 /* In IEEE floating point, x*1 is not equivalent to x for snans.
5516 However, ANSI says we can drop signals,
5517 so we can do this anyway. */
5518 if (real_onep (arg1))
5519 return non_lvalue (convert (type, arg0));
5521 if (! wins && real_twop (arg1) && global_bindings_p () == 0
5522 && ! contains_placeholder_p (arg0))
5524 tree arg = save_expr (arg0);
5525 return build (PLUS_EXPR, type, arg, arg);
5532 if (integer_all_onesp (arg1))
5533 return omit_one_operand (type, arg1, arg0);
5534 if (integer_zerop (arg1))
5535 return non_lvalue (convert (type, arg0));
5536 t1 = distribute_bit_expr (code, type, arg0, arg1);
5537 if (t1 != NULL_TREE)
5540 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
5542 This results in more efficient code for machines without a NAND
5543 instruction. Combine will canonicalize to the first form
5544 which will allow use of NAND instructions provided by the
5545 backend if they exist. */
5546 if (TREE_CODE (arg0) == BIT_NOT_EXPR
5547 && TREE_CODE (arg1) == BIT_NOT_EXPR)
5549 return fold (build1 (BIT_NOT_EXPR, type,
5550 build (BIT_AND_EXPR, type,
5551 TREE_OPERAND (arg0, 0),
5552 TREE_OPERAND (arg1, 0))));
5555 /* See if this can be simplified into a rotate first. If that
5556 is unsuccessful continue in the association code. */
5560 if (integer_zerop (arg1))
5561 return non_lvalue (convert (type, arg0));
5562 if (integer_all_onesp (arg1))
5563 return fold (build1 (BIT_NOT_EXPR, type, arg0));
5565 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
5566 with a constant, and the two constants have no bits in common,
5567 we should treat this as a BIT_IOR_EXPR since this may produce more
5569 if (TREE_CODE (arg0) == BIT_AND_EXPR
5570 && TREE_CODE (arg1) == BIT_AND_EXPR
5571 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5572 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
5573 && integer_zerop (const_binop (BIT_AND_EXPR,
5574 TREE_OPERAND (arg0, 1),
5575 TREE_OPERAND (arg1, 1), 0)))
5577 code = BIT_IOR_EXPR;
5581 /* See if this can be simplified into a rotate first. If that
5582 is unsuccessful continue in the association code. */
5587 if (integer_all_onesp (arg1))
5588 return non_lvalue (convert (type, arg0));
5589 if (integer_zerop (arg1))
5590 return omit_one_operand (type, arg1, arg0);
5591 t1 = distribute_bit_expr (code, type, arg0, arg1);
5592 if (t1 != NULL_TREE)
5594 /* Simplify ((int)c & 0x377) into (int)c, if c is unsigned char. */
5595 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == NOP_EXPR
5596 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg1, 0))))
5598 int prec = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg1, 0)));
5599 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
5600 && (~TREE_INT_CST_LOW (arg0)
5601 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
5602 return build1 (NOP_EXPR, type, TREE_OPERAND (arg1, 0));
5604 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
5605 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5607 int prec = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
5608 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
5609 && (~TREE_INT_CST_LOW (arg1)
5610 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
5611 return build1 (NOP_EXPR, type, TREE_OPERAND (arg0, 0));
5614 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
5616 This results in more efficient code for machines without a NOR
5617 instruction. Combine will canonicalize to the first form
5618 which will allow use of NOR instructions provided by the
5619 backend if they exist. */
5620 if (TREE_CODE (arg0) == BIT_NOT_EXPR
5621 && TREE_CODE (arg1) == BIT_NOT_EXPR)
5623 return fold (build1 (BIT_NOT_EXPR, type,
5624 build (BIT_IOR_EXPR, type,
5625 TREE_OPERAND (arg0, 0),
5626 TREE_OPERAND (arg1, 0))));
5631 case BIT_ANDTC_EXPR:
5632 if (integer_all_onesp (arg0))
5633 return non_lvalue (convert (type, arg1));
5634 if (integer_zerop (arg0))
5635 return omit_one_operand (type, arg0, arg1);
5636 if (TREE_CODE (arg1) == INTEGER_CST)
5638 arg1 = fold (build1 (BIT_NOT_EXPR, type, arg1));
5639 code = BIT_AND_EXPR;
5645 /* In most cases, do nothing with a divide by zero. */
5646 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
5647 #ifndef REAL_INFINITY
5648 if (TREE_CODE (arg1) == REAL_CST && real_zerop (arg1))
5651 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
5653 /* (-A) / (-B) -> A / B */
5654 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR)
5655 return fold (build (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
5656 TREE_OPERAND (arg1, 0)));
5658 /* In IEEE floating point, x/1 is not equivalent to x for snans.
5659 However, ANSI says we can drop signals, so we can do this anyway. */
5660 if (real_onep (arg1))
5661 return non_lvalue (convert (type, arg0));
5663 /* If ARG1 is a constant, we can convert this to a multiply by the
5664 reciprocal. This does not have the same rounding properties,
5665 so only do this if -ffast-math. We can actually always safely
5666 do it if ARG1 is a power of two, but it's hard to tell if it is
5667 or not in a portable manner. */
5668 if (TREE_CODE (arg1) == REAL_CST)
5671 && 0 != (tem = const_binop (code, build_real (type, dconst1),
5673 return fold (build (MULT_EXPR, type, arg0, tem));
5674 /* Find the reciprocal if optimizing and the result is exact. */
5678 r = TREE_REAL_CST (arg1);
5679 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
5681 tem = build_real (type, r);
5682 return fold (build (MULT_EXPR, type, arg0, tem));
5688 case TRUNC_DIV_EXPR:
5689 case ROUND_DIV_EXPR:
5690 case FLOOR_DIV_EXPR:
5692 case EXACT_DIV_EXPR:
5693 if (integer_onep (arg1))
5694 return non_lvalue (convert (type, arg0));
5695 if (integer_zerop (arg1))
5698 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
5699 operation, EXACT_DIV_EXPR.
5701 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
5702 At one time others generated faster code, it's not clear if they do
5703 after the last round to changes to the DIV code in expmed.c. */
5704 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
5705 && multiple_of_p (type, arg0, arg1))
5706 return fold (build (EXACT_DIV_EXPR, type, arg0, arg1));
5708 if (TREE_CODE (arg1) == INTEGER_CST
5709 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
5711 return convert (type, tem);
5716 case FLOOR_MOD_EXPR:
5717 case ROUND_MOD_EXPR:
5718 case TRUNC_MOD_EXPR:
5719 if (integer_onep (arg1))
5720 return omit_one_operand (type, integer_zero_node, arg0);
5721 if (integer_zerop (arg1))
5724 if (TREE_CODE (arg1) == INTEGER_CST
5725 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
5727 return convert (type, tem);
5735 if (integer_zerop (arg1))
5736 return non_lvalue (convert (type, arg0));
5737 /* Since negative shift count is not well-defined,
5738 don't try to compute it in the compiler. */
5739 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
5741 /* Rewrite an LROTATE_EXPR by a constant into an
5742 RROTATE_EXPR by a new constant. */
5743 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
5745 TREE_SET_CODE (t, RROTATE_EXPR);
5746 code = RROTATE_EXPR;
5747 TREE_OPERAND (t, 1) = arg1
5750 convert (TREE_TYPE (arg1),
5751 build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type)), 0)),
5753 if (tree_int_cst_sgn (arg1) < 0)
5757 /* If we have a rotate of a bit operation with the rotate count and
5758 the second operand of the bit operation both constant,
5759 permute the two operations. */
5760 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
5761 && (TREE_CODE (arg0) == BIT_AND_EXPR
5762 || TREE_CODE (arg0) == BIT_ANDTC_EXPR
5763 || TREE_CODE (arg0) == BIT_IOR_EXPR
5764 || TREE_CODE (arg0) == BIT_XOR_EXPR)
5765 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
5766 return fold (build (TREE_CODE (arg0), type,
5767 fold (build (code, type,
5768 TREE_OPERAND (arg0, 0), arg1)),
5769 fold (build (code, type,
5770 TREE_OPERAND (arg0, 1), arg1))));
5772 /* Two consecutive rotates adding up to the width of the mode can
5774 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
5775 && TREE_CODE (arg0) == RROTATE_EXPR
5776 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5777 && TREE_INT_CST_HIGH (arg1) == 0
5778 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
5779 && ((TREE_INT_CST_LOW (arg1)
5780 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
5781 == GET_MODE_BITSIZE (TYPE_MODE (type))))
5782 return TREE_OPERAND (arg0, 0);
5787 if (operand_equal_p (arg0, arg1, 0))
5789 if (INTEGRAL_TYPE_P (type)
5790 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), 1))
5791 return omit_one_operand (type, arg1, arg0);
5795 if (operand_equal_p (arg0, arg1, 0))
5797 if (INTEGRAL_TYPE_P (type)
5798 && TYPE_MAX_VALUE (type)
5799 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), 1))
5800 return omit_one_operand (type, arg1, arg0);
5803 case TRUTH_NOT_EXPR:
5804 /* Note that the operand of this must be an int
5805 and its values must be 0 or 1.
5806 ("true" is a fixed value perhaps depending on the language,
5807 but we don't handle values other than 1 correctly yet.) */
5808 tem = invert_truthvalue (arg0);
5809 /* Avoid infinite recursion. */
5810 if (TREE_CODE (tem) == TRUTH_NOT_EXPR)
5812 return convert (type, tem);
5814 case TRUTH_ANDIF_EXPR:
5815 /* Note that the operands of this must be ints
5816 and their values must be 0 or 1.
5817 ("true" is a fixed value perhaps depending on the language.) */
5818 /* If first arg is constant zero, return it. */
5819 if (integer_zerop (arg0))
5821 case TRUTH_AND_EXPR:
5822 /* If either arg is constant true, drop it. */
5823 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
5824 return non_lvalue (arg1);
5825 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
5826 return non_lvalue (arg0);
5827 /* If second arg is constant zero, result is zero, but first arg
5828 must be evaluated. */
5829 if (integer_zerop (arg1))
5830 return omit_one_operand (type, arg1, arg0);
5831 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
5832 case will be handled here. */
5833 if (integer_zerop (arg0))
5834 return omit_one_operand (type, arg0, arg1);
5837 /* We only do these simplifications if we are optimizing. */
5841 /* Check for things like (A || B) && (A || C). We can convert this
5842 to A || (B && C). Note that either operator can be any of the four
5843 truth and/or operations and the transformation will still be
5844 valid. Also note that we only care about order for the
5845 ANDIF and ORIF operators. If B contains side effects, this
5846 might change the truth-value of A. */
5847 if (TREE_CODE (arg0) == TREE_CODE (arg1)
5848 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
5849 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
5850 || TREE_CODE (arg0) == TRUTH_AND_EXPR
5851 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
5852 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
5854 tree a00 = TREE_OPERAND (arg0, 0);
5855 tree a01 = TREE_OPERAND (arg0, 1);
5856 tree a10 = TREE_OPERAND (arg1, 0);
5857 tree a11 = TREE_OPERAND (arg1, 1);
5858 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
5859 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
5860 && (code == TRUTH_AND_EXPR
5861 || code == TRUTH_OR_EXPR));
5863 if (operand_equal_p (a00, a10, 0))
5864 return fold (build (TREE_CODE (arg0), type, a00,
5865 fold (build (code, type, a01, a11))));
5866 else if (commutative && operand_equal_p (a00, a11, 0))
5867 return fold (build (TREE_CODE (arg0), type, a00,
5868 fold (build (code, type, a01, a10))));
5869 else if (commutative && operand_equal_p (a01, a10, 0))
5870 return fold (build (TREE_CODE (arg0), type, a01,
5871 fold (build (code, type, a00, a11))));
5873 /* This case if tricky because we must either have commutative
5874 operators or else A10 must not have side-effects. */
5876 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
5877 && operand_equal_p (a01, a11, 0))
5878 return fold (build (TREE_CODE (arg0), type,
5879 fold (build (code, type, a00, a10)),
5883 /* See if we can build a range comparison. */
5884 if (0 != (tem = fold_range_test (t)))
5887 /* Check for the possibility of merging component references. If our
5888 lhs is another similar operation, try to merge its rhs with our
5889 rhs. Then try to merge our lhs and rhs. */
5890 if (TREE_CODE (arg0) == code
5891 && 0 != (tem = fold_truthop (code, type,
5892 TREE_OPERAND (arg0, 1), arg1)))
5893 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
5895 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
5900 case TRUTH_ORIF_EXPR:
5901 /* Note that the operands of this must be ints
5902 and their values must be 0 or true.
5903 ("true" is a fixed value perhaps depending on the language.) */
5904 /* If first arg is constant true, return it. */
5905 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
5908 /* If either arg is constant zero, drop it. */
5909 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
5910 return non_lvalue (arg1);
5911 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1))
5912 return non_lvalue (arg0);
5913 /* If second arg is constant true, result is true, but we must
5914 evaluate first arg. */
5915 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
5916 return omit_one_operand (type, arg1, arg0);
5917 /* Likewise for first arg, but note this only occurs here for
5919 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
5920 return omit_one_operand (type, arg0, arg1);
5923 case TRUTH_XOR_EXPR:
5924 /* If either arg is constant zero, drop it. */
5925 if (integer_zerop (arg0))
5926 return non_lvalue (arg1);
5927 if (integer_zerop (arg1))
5928 return non_lvalue (arg0);
5929 /* If either arg is constant true, this is a logical inversion. */
5930 if (integer_onep (arg0))
5931 return non_lvalue (invert_truthvalue (arg1));
5932 if (integer_onep (arg1))
5933 return non_lvalue (invert_truthvalue (arg0));
5942 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
5944 /* (-a) CMP (-b) -> b CMP a */
5945 if (TREE_CODE (arg0) == NEGATE_EXPR
5946 && TREE_CODE (arg1) == NEGATE_EXPR)
5947 return fold (build (code, type, TREE_OPERAND (arg1, 0),
5948 TREE_OPERAND (arg0, 0)));
5949 /* (-a) CMP CST -> a swap(CMP) (-CST) */
5950 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == REAL_CST)
5953 (swap_tree_comparison (code), type,
5954 TREE_OPERAND (arg0, 0),
5955 build_real (TREE_TYPE (arg1),
5956 REAL_VALUE_NEGATE (TREE_REAL_CST (arg1)))));
5957 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
5958 /* a CMP (-0) -> a CMP 0 */
5959 if (TREE_CODE (arg1) == REAL_CST
5960 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (arg1)))
5961 return fold (build (code, type, arg0,
5962 build_real (TREE_TYPE (arg1), dconst0)));
5966 /* If one arg is a constant integer, put it last. */
5967 if (TREE_CODE (arg0) == INTEGER_CST
5968 && TREE_CODE (arg1) != INTEGER_CST)
5970 TREE_OPERAND (t, 0) = arg1;
5971 TREE_OPERAND (t, 1) = arg0;
5972 arg0 = TREE_OPERAND (t, 0);
5973 arg1 = TREE_OPERAND (t, 1);
5974 code = swap_tree_comparison (code);
5975 TREE_SET_CODE (t, code);
5978 /* Convert foo++ == CONST into ++foo == CONST + INCR.
5979 First, see if one arg is constant; find the constant arg
5980 and the other one. */
5982 tree constop = 0, varop = NULL_TREE;
5983 int constopnum = -1;
5985 if (TREE_CONSTANT (arg1))
5986 constopnum = 1, constop = arg1, varop = arg0;
5987 if (TREE_CONSTANT (arg0))
5988 constopnum = 0, constop = arg0, varop = arg1;
5990 if (constop && TREE_CODE (varop) == POSTINCREMENT_EXPR)
5992 /* This optimization is invalid for ordered comparisons
5993 if CONST+INCR overflows or if foo+incr might overflow.
5994 This optimization is invalid for floating point due to rounding.
5995 For pointer types we assume overflow doesn't happen. */
5996 if (POINTER_TYPE_P (TREE_TYPE (varop))
5997 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
5998 && (code == EQ_EXPR || code == NE_EXPR)))
6001 = fold (build (PLUS_EXPR, TREE_TYPE (varop),
6002 constop, TREE_OPERAND (varop, 1)));
6003 TREE_SET_CODE (varop, PREINCREMENT_EXPR);
6005 /* If VAROP is a reference to a bitfield, we must mask
6006 the constant by the width of the field. */
6007 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
6008 && DECL_BIT_FIELD(TREE_OPERAND
6009 (TREE_OPERAND (varop, 0), 1)))
6012 = TREE_INT_CST_LOW (DECL_SIZE
6014 (TREE_OPERAND (varop, 0), 1)));
6015 tree mask, unsigned_type;
6017 tree folded_compare;
6019 /* First check whether the comparison would come out
6020 always the same. If we don't do that we would
6021 change the meaning with the masking. */
6022 if (constopnum == 0)
6023 folded_compare = fold (build (code, type, constop,
6024 TREE_OPERAND (varop, 0)));
6026 folded_compare = fold (build (code, type,
6027 TREE_OPERAND (varop, 0),
6029 if (integer_zerop (folded_compare)
6030 || integer_onep (folded_compare))
6031 return omit_one_operand (type, folded_compare, varop);
6033 unsigned_type = type_for_size (size, 1);
6034 precision = TYPE_PRECISION (unsigned_type);
6035 mask = build_int_2 (~0, ~0);
6036 TREE_TYPE (mask) = unsigned_type;
6037 force_fit_type (mask, 0);
6038 mask = const_binop (RSHIFT_EXPR, mask,
6039 size_int (precision - size), 0);
6040 newconst = fold (build (BIT_AND_EXPR,
6041 TREE_TYPE (varop), newconst,
6042 convert (TREE_TYPE (varop),
6047 t = build (code, type, TREE_OPERAND (t, 0),
6048 TREE_OPERAND (t, 1));
6049 TREE_OPERAND (t, constopnum) = newconst;
6053 else if (constop && TREE_CODE (varop) == POSTDECREMENT_EXPR)
6055 if (POINTER_TYPE_P (TREE_TYPE (varop))
6056 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
6057 && (code == EQ_EXPR || code == NE_EXPR)))
6060 = fold (build (MINUS_EXPR, TREE_TYPE (varop),
6061 constop, TREE_OPERAND (varop, 1)));
6062 TREE_SET_CODE (varop, PREDECREMENT_EXPR);
6064 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
6065 && DECL_BIT_FIELD(TREE_OPERAND
6066 (TREE_OPERAND (varop, 0), 1)))
6069 = TREE_INT_CST_LOW (DECL_SIZE
6071 (TREE_OPERAND (varop, 0), 1)));
6072 tree mask, unsigned_type;
6074 tree folded_compare;
6076 if (constopnum == 0)
6077 folded_compare = fold (build (code, type, constop,
6078 TREE_OPERAND (varop, 0)));
6080 folded_compare = fold (build (code, type,
6081 TREE_OPERAND (varop, 0),
6083 if (integer_zerop (folded_compare)
6084 || integer_onep (folded_compare))
6085 return omit_one_operand (type, folded_compare, varop);
6087 unsigned_type = type_for_size (size, 1);
6088 precision = TYPE_PRECISION (unsigned_type);
6089 mask = build_int_2 (~0, ~0);
6090 TREE_TYPE (mask) = TREE_TYPE (varop);
6091 force_fit_type (mask, 0);
6092 mask = const_binop (RSHIFT_EXPR, mask,
6093 size_int (precision - size), 0);
6094 newconst = fold (build (BIT_AND_EXPR,
6095 TREE_TYPE (varop), newconst,
6096 convert (TREE_TYPE (varop),
6101 t = build (code, type, TREE_OPERAND (t, 0),
6102 TREE_OPERAND (t, 1));
6103 TREE_OPERAND (t, constopnum) = newconst;
6109 /* Change X >= CST to X > (CST - 1) if CST is positive. */
6110 if (TREE_CODE (arg1) == INTEGER_CST
6111 && TREE_CODE (arg0) != INTEGER_CST
6112 && tree_int_cst_sgn (arg1) > 0)
6114 switch (TREE_CODE (t))
6118 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6119 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6124 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6125 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6133 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
6134 a MINUS_EXPR of a constant, we can convert it into a comparison with
6135 a revised constant as long as no overflow occurs. */
6136 if ((code == EQ_EXPR || code == NE_EXPR)
6137 && TREE_CODE (arg1) == INTEGER_CST
6138 && (TREE_CODE (arg0) == PLUS_EXPR
6139 || TREE_CODE (arg0) == MINUS_EXPR)
6140 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6141 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
6142 ? MINUS_EXPR : PLUS_EXPR,
6143 arg1, TREE_OPERAND (arg0, 1), 0))
6144 && ! TREE_CONSTANT_OVERFLOW (tem))
6145 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6147 /* Similarly for a NEGATE_EXPR. */
6148 else if ((code == EQ_EXPR || code == NE_EXPR)
6149 && TREE_CODE (arg0) == NEGATE_EXPR
6150 && TREE_CODE (arg1) == INTEGER_CST
6151 && 0 != (tem = negate_expr (arg1))
6152 && TREE_CODE (tem) == INTEGER_CST
6153 && ! TREE_CONSTANT_OVERFLOW (tem))
6154 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6156 /* If we have X - Y == 0, we can convert that to X == Y and similarly
6157 for !=. Don't do this for ordered comparisons due to overflow. */
6158 else if ((code == NE_EXPR || code == EQ_EXPR)
6159 && integer_zerop (arg1) && TREE_CODE (arg0) == MINUS_EXPR)
6160 return fold (build (code, type,
6161 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1)));
6163 /* If we are widening one operand of an integer comparison,
6164 see if the other operand is similarly being widened. Perhaps we
6165 can do the comparison in the narrower type. */
6166 else if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
6167 && TREE_CODE (arg0) == NOP_EXPR
6168 && (tem = get_unwidened (arg0, NULL_TREE)) != arg0
6169 && (t1 = get_unwidened (arg1, TREE_TYPE (tem))) != 0
6170 && (TREE_TYPE (t1) == TREE_TYPE (tem)
6171 || (TREE_CODE (t1) == INTEGER_CST
6172 && int_fits_type_p (t1, TREE_TYPE (tem)))))
6173 return fold (build (code, type, tem, convert (TREE_TYPE (tem), t1)));
6175 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
6176 constant, we can simplify it. */
6177 else if (TREE_CODE (arg1) == INTEGER_CST
6178 && (TREE_CODE (arg0) == MIN_EXPR
6179 || TREE_CODE (arg0) == MAX_EXPR)
6180 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
6181 return optimize_minmax_comparison (t);
6183 /* If we are comparing an ABS_EXPR with a constant, we can
6184 convert all the cases into explicit comparisons, but they may
6185 well not be faster than doing the ABS and one comparison.
6186 But ABS (X) <= C is a range comparison, which becomes a subtraction
6187 and a comparison, and is probably faster. */
6188 else if (code == LE_EXPR && TREE_CODE (arg1) == INTEGER_CST
6189 && TREE_CODE (arg0) == ABS_EXPR
6190 && ! TREE_SIDE_EFFECTS (arg0)
6191 && (0 != (tem = negate_expr (arg1)))
6192 && TREE_CODE (tem) == INTEGER_CST
6193 && ! TREE_CONSTANT_OVERFLOW (tem))
6194 return fold (build (TRUTH_ANDIF_EXPR, type,
6195 build (GE_EXPR, type, TREE_OPERAND (arg0, 0), tem),
6196 build (LE_EXPR, type,
6197 TREE_OPERAND (arg0, 0), arg1)));
6199 /* If this is an EQ or NE comparison with zero and ARG0 is
6200 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
6201 two operations, but the latter can be done in one less insn
6202 on machines that have only two-operand insns or on which a
6203 constant cannot be the first operand. */
6204 if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR)
6205 && TREE_CODE (arg0) == BIT_AND_EXPR)
6207 if (TREE_CODE (TREE_OPERAND (arg0, 0)) == LSHIFT_EXPR
6208 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 0), 0)))
6210 fold (build (code, type,
6211 build (BIT_AND_EXPR, TREE_TYPE (arg0),
6213 TREE_TYPE (TREE_OPERAND (arg0, 0)),
6214 TREE_OPERAND (arg0, 1),
6215 TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)),
6216 convert (TREE_TYPE (arg0),
6219 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
6220 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
6222 fold (build (code, type,
6223 build (BIT_AND_EXPR, TREE_TYPE (arg0),
6225 TREE_TYPE (TREE_OPERAND (arg0, 1)),
6226 TREE_OPERAND (arg0, 0),
6227 TREE_OPERAND (TREE_OPERAND (arg0, 1), 1)),
6228 convert (TREE_TYPE (arg0),
6233 /* If this is an NE or EQ comparison of zero against the result of a
6234 signed MOD operation whose second operand is a power of 2, make
6235 the MOD operation unsigned since it is simpler and equivalent. */
6236 if ((code == NE_EXPR || code == EQ_EXPR)
6237 && integer_zerop (arg1)
6238 && ! TREE_UNSIGNED (TREE_TYPE (arg0))
6239 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
6240 || TREE_CODE (arg0) == CEIL_MOD_EXPR
6241 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
6242 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
6243 && integer_pow2p (TREE_OPERAND (arg0, 1)))
6245 tree newtype = unsigned_type (TREE_TYPE (arg0));
6246 tree newmod = build (TREE_CODE (arg0), newtype,
6247 convert (newtype, TREE_OPERAND (arg0, 0)),
6248 convert (newtype, TREE_OPERAND (arg0, 1)));
6250 return build (code, type, newmod, convert (newtype, arg1));
6253 /* If this is an NE comparison of zero with an AND of one, remove the
6254 comparison since the AND will give the correct value. */
6255 if (code == NE_EXPR && integer_zerop (arg1)
6256 && TREE_CODE (arg0) == BIT_AND_EXPR
6257 && integer_onep (TREE_OPERAND (arg0, 1)))
6258 return convert (type, arg0);
6260 /* If we have (A & C) == C where C is a power of 2, convert this into
6261 (A & C) != 0. Similarly for NE_EXPR. */
6262 if ((code == EQ_EXPR || code == NE_EXPR)
6263 && TREE_CODE (arg0) == BIT_AND_EXPR
6264 && integer_pow2p (TREE_OPERAND (arg0, 1))
6265 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
6266 return build (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
6267 arg0, integer_zero_node);
6269 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
6270 and similarly for >= into !=. */
6271 if ((code == LT_EXPR || code == GE_EXPR)
6272 && TREE_UNSIGNED (TREE_TYPE (arg0))
6273 && TREE_CODE (arg1) == LSHIFT_EXPR
6274 && integer_onep (TREE_OPERAND (arg1, 0)))
6275 return build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
6276 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
6277 TREE_OPERAND (arg1, 1)),
6278 convert (TREE_TYPE (arg0), integer_zero_node));
6280 else if ((code == LT_EXPR || code == GE_EXPR)
6281 && TREE_UNSIGNED (TREE_TYPE (arg0))
6282 && (TREE_CODE (arg1) == NOP_EXPR
6283 || TREE_CODE (arg1) == CONVERT_EXPR)
6284 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
6285 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
6287 build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
6288 convert (TREE_TYPE (arg0),
6289 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
6290 TREE_OPERAND (TREE_OPERAND (arg1, 0), 1))),
6291 convert (TREE_TYPE (arg0), integer_zero_node));
6293 /* Simplify comparison of something with itself. (For IEEE
6294 floating-point, we can only do some of these simplifications.) */
6295 if (operand_equal_p (arg0, arg1, 0))
6302 if (INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
6303 return constant_boolean_node (1, type);
6305 TREE_SET_CODE (t, code);
6309 /* For NE, we can only do this simplification if integer. */
6310 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
6312 /* ... fall through ... */
6315 return constant_boolean_node (0, type);
6321 /* An unsigned comparison against 0 can be simplified. */
6322 if (integer_zerop (arg1)
6323 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
6324 || POINTER_TYPE_P (TREE_TYPE (arg1)))
6325 && TREE_UNSIGNED (TREE_TYPE (arg1)))
6327 switch (TREE_CODE (t))
6331 TREE_SET_CODE (t, NE_EXPR);
6335 TREE_SET_CODE (t, EQ_EXPR);
6338 return omit_one_operand (type,
6339 convert (type, integer_one_node),
6342 return omit_one_operand (type,
6343 convert (type, integer_zero_node),
6350 /* Comparisons with the highest or lowest possible integer of
6351 the specified size will have known values and an unsigned
6352 <= 0x7fffffff can be simplified. */
6354 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1)));
6356 if (TREE_CODE (arg1) == INTEGER_CST
6357 && ! TREE_CONSTANT_OVERFLOW (arg1)
6358 && width <= HOST_BITS_PER_WIDE_INT
6359 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
6360 || POINTER_TYPE_P (TREE_TYPE (arg1))))
6362 if (TREE_INT_CST_HIGH (arg1) == 0
6363 && (TREE_INT_CST_LOW (arg1)
6364 == ((HOST_WIDE_INT) 1 << (width - 1)) - 1)
6365 && ! TREE_UNSIGNED (TREE_TYPE (arg1)))
6366 switch (TREE_CODE (t))
6369 return omit_one_operand (type,
6370 convert (type, integer_zero_node),
6373 TREE_SET_CODE (t, EQ_EXPR);
6377 return omit_one_operand (type,
6378 convert (type, integer_one_node),
6381 TREE_SET_CODE (t, NE_EXPR);
6388 else if (TREE_INT_CST_HIGH (arg1) == -1
6389 && (- TREE_INT_CST_LOW (arg1)
6390 == ((HOST_WIDE_INT) 1 << (width - 1)))
6391 && ! TREE_UNSIGNED (TREE_TYPE (arg1)))
6392 switch (TREE_CODE (t))
6395 return omit_one_operand (type,
6396 convert (type, integer_zero_node),
6399 TREE_SET_CODE (t, EQ_EXPR);
6403 return omit_one_operand (type,
6404 convert (type, integer_one_node),
6407 TREE_SET_CODE (t, NE_EXPR);
6414 else if (TREE_INT_CST_HIGH (arg1) == 0
6415 && (TREE_INT_CST_LOW (arg1)
6416 == ((HOST_WIDE_INT) 1 << (width - 1)) - 1)
6417 && TREE_UNSIGNED (TREE_TYPE (arg1)))
6419 switch (TREE_CODE (t))
6422 return fold (build (GE_EXPR, type,
6423 convert (signed_type (TREE_TYPE (arg0)),
6425 convert (signed_type (TREE_TYPE (arg1)),
6426 integer_zero_node)));
6428 return fold (build (LT_EXPR, type,
6429 convert (signed_type (TREE_TYPE (arg0)),
6431 convert (signed_type (TREE_TYPE (arg1)),
6432 integer_zero_node)));
6440 /* If we are comparing an expression that just has comparisons
6441 of two integer values, arithmetic expressions of those comparisons,
6442 and constants, we can simplify it. There are only three cases
6443 to check: the two values can either be equal, the first can be
6444 greater, or the second can be greater. Fold the expression for
6445 those three values. Since each value must be 0 or 1, we have
6446 eight possibilities, each of which corresponds to the constant 0
6447 or 1 or one of the six possible comparisons.
6449 This handles common cases like (a > b) == 0 but also handles
6450 expressions like ((x > y) - (y > x)) > 0, which supposedly
6451 occur in macroized code. */
6453 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
6455 tree cval1 = 0, cval2 = 0;
6458 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
6459 /* Don't handle degenerate cases here; they should already
6460 have been handled anyway. */
6461 && cval1 != 0 && cval2 != 0
6462 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
6463 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
6464 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
6465 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
6466 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
6467 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
6468 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
6470 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
6471 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
6473 /* We can't just pass T to eval_subst in case cval1 or cval2
6474 was the same as ARG1. */
6477 = fold (build (code, type,
6478 eval_subst (arg0, cval1, maxval, cval2, minval),
6481 = fold (build (code, type,
6482 eval_subst (arg0, cval1, maxval, cval2, maxval),
6485 = fold (build (code, type,
6486 eval_subst (arg0, cval1, minval, cval2, maxval),
6489 /* All three of these results should be 0 or 1. Confirm they
6490 are. Then use those values to select the proper code
6493 if ((integer_zerop (high_result)
6494 || integer_onep (high_result))
6495 && (integer_zerop (equal_result)
6496 || integer_onep (equal_result))
6497 && (integer_zerop (low_result)
6498 || integer_onep (low_result)))
6500 /* Make a 3-bit mask with the high-order bit being the
6501 value for `>', the next for '=', and the low for '<'. */
6502 switch ((integer_onep (high_result) * 4)
6503 + (integer_onep (equal_result) * 2)
6504 + integer_onep (low_result))
6508 return omit_one_operand (type, integer_zero_node, arg0);
6529 return omit_one_operand (type, integer_one_node, arg0);
6532 t = build (code, type, cval1, cval2);
6534 return save_expr (t);
6541 /* If this is a comparison of a field, we may be able to simplify it. */
6542 if ((TREE_CODE (arg0) == COMPONENT_REF
6543 || TREE_CODE (arg0) == BIT_FIELD_REF)
6544 && (code == EQ_EXPR || code == NE_EXPR)
6545 /* Handle the constant case even without -O
6546 to make sure the warnings are given. */
6547 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
6549 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
6553 /* If this is a comparison of complex values and either or both sides
6554 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
6555 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
6556 This may prevent needless evaluations. */
6557 if ((code == EQ_EXPR || code == NE_EXPR)
6558 && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
6559 && (TREE_CODE (arg0) == COMPLEX_EXPR
6560 || TREE_CODE (arg1) == COMPLEX_EXPR
6561 || TREE_CODE (arg0) == COMPLEX_CST
6562 || TREE_CODE (arg1) == COMPLEX_CST))
6564 tree subtype = TREE_TYPE (TREE_TYPE (arg0));
6565 tree real0, imag0, real1, imag1;
6567 arg0 = save_expr (arg0);
6568 arg1 = save_expr (arg1);
6569 real0 = fold (build1 (REALPART_EXPR, subtype, arg0));
6570 imag0 = fold (build1 (IMAGPART_EXPR, subtype, arg0));
6571 real1 = fold (build1 (REALPART_EXPR, subtype, arg1));
6572 imag1 = fold (build1 (IMAGPART_EXPR, subtype, arg1));
6574 return fold (build ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR
6577 fold (build (code, type, real0, real1)),
6578 fold (build (code, type, imag0, imag1))));
6581 /* From here on, the only cases we handle are when the result is
6582 known to be a constant.
6584 To compute GT, swap the arguments and do LT.
6585 To compute GE, do LT and invert the result.
6586 To compute LE, swap the arguments, do LT and invert the result.
6587 To compute NE, do EQ and invert the result.
6589 Therefore, the code below must handle only EQ and LT. */
6591 if (code == LE_EXPR || code == GT_EXPR)
6593 tem = arg0, arg0 = arg1, arg1 = tem;
6594 code = swap_tree_comparison (code);
6597 /* Note that it is safe to invert for real values here because we
6598 will check below in the one case that it matters. */
6602 if (code == NE_EXPR || code == GE_EXPR)
6605 code = invert_tree_comparison (code);
6608 /* Compute a result for LT or EQ if args permit;
6609 otherwise return T. */
6610 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
6612 if (code == EQ_EXPR)
6613 t1 = build_int_2 ((TREE_INT_CST_LOW (arg0)
6614 == TREE_INT_CST_LOW (arg1))
6615 && (TREE_INT_CST_HIGH (arg0)
6616 == TREE_INT_CST_HIGH (arg1)),
6619 t1 = build_int_2 ((TREE_UNSIGNED (TREE_TYPE (arg0))
6620 ? INT_CST_LT_UNSIGNED (arg0, arg1)
6621 : INT_CST_LT (arg0, arg1)),
6625 #if 0 /* This is no longer useful, but breaks some real code. */
6626 /* Assume a nonexplicit constant cannot equal an explicit one,
6627 since such code would be undefined anyway.
6628 Exception: on sysvr4, using #pragma weak,
6629 a label can come out as 0. */
6630 else if (TREE_CODE (arg1) == INTEGER_CST
6631 && !integer_zerop (arg1)
6632 && TREE_CONSTANT (arg0)
6633 && TREE_CODE (arg0) == ADDR_EXPR
6635 t1 = build_int_2 (0, 0);
6637 /* Two real constants can be compared explicitly. */
6638 else if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
6640 /* If either operand is a NaN, the result is false with two
6641 exceptions: First, an NE_EXPR is true on NaNs, but that case
6642 is already handled correctly since we will be inverting the
6643 result for NE_EXPR. Second, if we had inverted a LE_EXPR
6644 or a GE_EXPR into a LT_EXPR, we must return true so that it
6645 will be inverted into false. */
6647 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
6648 || REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
6649 t1 = build_int_2 (invert && code == LT_EXPR, 0);
6651 else if (code == EQ_EXPR)
6652 t1 = build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (arg0),
6653 TREE_REAL_CST (arg1)),
6656 t1 = build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (arg0),
6657 TREE_REAL_CST (arg1)),
6661 if (t1 == NULL_TREE)
6665 TREE_INT_CST_LOW (t1) ^= 1;
6667 TREE_TYPE (t1) = type;
6668 if (TREE_CODE (type) == BOOLEAN_TYPE)
6669 return truthvalue_conversion (t1);
6673 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
6674 so all simple results must be passed through pedantic_non_lvalue. */
6675 if (TREE_CODE (arg0) == INTEGER_CST)
6676 return pedantic_non_lvalue
6677 (TREE_OPERAND (t, (integer_zerop (arg0) ? 2 : 1)));
6678 else if (operand_equal_p (arg1, TREE_OPERAND (expr, 2), 0))
6679 return pedantic_omit_one_operand (type, arg1, arg0);
6681 /* If the second operand is zero, invert the comparison and swap
6682 the second and third operands. Likewise if the second operand
6683 is constant and the third is not or if the third operand is
6684 equivalent to the first operand of the comparison. */
6686 if (integer_zerop (arg1)
6687 || (TREE_CONSTANT (arg1) && ! TREE_CONSTANT (TREE_OPERAND (t, 2)))
6688 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
6689 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
6690 TREE_OPERAND (t, 2),
6691 TREE_OPERAND (arg0, 1))))
6693 /* See if this can be inverted. If it can't, possibly because
6694 it was a floating-point inequality comparison, don't do
6696 tem = invert_truthvalue (arg0);
6698 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
6700 t = build (code, type, tem,
6701 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
6703 /* arg1 should be the first argument of the new T. */
6704 arg1 = TREE_OPERAND (t, 1);
6709 /* If we have A op B ? A : C, we may be able to convert this to a
6710 simpler expression, depending on the operation and the values
6711 of B and C. IEEE floating point prevents this though,
6712 because A or B might be -0.0 or a NaN. */
6714 if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
6715 && (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
6716 || ! FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 0)))
6718 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
6719 arg1, TREE_OPERAND (arg0, 1)))
6721 tree arg2 = TREE_OPERAND (t, 2);
6722 enum tree_code comp_code = TREE_CODE (arg0);
6726 /* If we have A op 0 ? A : -A, this is A, -A, abs (A), or abs (-A),
6727 depending on the comparison operation. */
6728 if ((FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 1)))
6729 ? real_zerop (TREE_OPERAND (arg0, 1))
6730 : integer_zerop (TREE_OPERAND (arg0, 1)))
6731 && TREE_CODE (arg2) == NEGATE_EXPR
6732 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
6736 return pedantic_non_lvalue (negate_expr (arg1));
6738 return pedantic_non_lvalue (convert (type, arg1));
6741 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
6742 arg1 = convert (signed_type (TREE_TYPE (arg1)), arg1);
6743 return pedantic_non_lvalue
6744 (convert (type, fold (build1 (ABS_EXPR,
6745 TREE_TYPE (arg1), arg1))));
6748 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
6749 arg1 = convert (signed_type (TREE_TYPE (arg1)), arg1);
6750 return pedantic_non_lvalue
6751 (negate_expr (convert (type,
6752 fold (build1 (ABS_EXPR,
6759 /* If this is A != 0 ? A : 0, this is simply A. For ==, it is
6762 if (integer_zerop (TREE_OPERAND (arg0, 1)) && integer_zerop (arg2))
6764 if (comp_code == NE_EXPR)
6765 return pedantic_non_lvalue (convert (type, arg1));
6766 else if (comp_code == EQ_EXPR)
6767 return pedantic_non_lvalue (convert (type, integer_zero_node));
6770 /* If this is A op B ? A : B, this is either A, B, min (A, B),
6771 or max (A, B), depending on the operation. */
6773 if (operand_equal_for_comparison_p (TREE_OPERAND (arg0, 1),
6774 arg2, TREE_OPERAND (arg0, 0)))
6776 tree comp_op0 = TREE_OPERAND (arg0, 0);
6777 tree comp_op1 = TREE_OPERAND (arg0, 1);
6778 tree comp_type = TREE_TYPE (comp_op0);
6783 return pedantic_non_lvalue (convert (type, arg2));
6785 return pedantic_non_lvalue (convert (type, arg1));
6788 /* In C++ a ?: expression can be an lvalue, so put the
6789 operand which will be used if they are equal first
6790 so that we can convert this back to the
6791 corresponding COND_EXPR. */
6792 return pedantic_non_lvalue
6793 (convert (type, (fold (build (MIN_EXPR, comp_type,
6794 (comp_code == LE_EXPR
6795 ? comp_op0 : comp_op1),
6796 (comp_code == LE_EXPR
6797 ? comp_op1 : comp_op0))))));
6801 return pedantic_non_lvalue
6802 (convert (type, fold (build (MAX_EXPR, comp_type,
6803 (comp_code == GE_EXPR
6804 ? comp_op0 : comp_op1),
6805 (comp_code == GE_EXPR
6806 ? comp_op1 : comp_op0)))));
6813 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
6814 we might still be able to simplify this. For example,
6815 if C1 is one less or one more than C2, this might have started
6816 out as a MIN or MAX and been transformed by this function.
6817 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
6819 if (INTEGRAL_TYPE_P (type)
6820 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6821 && TREE_CODE (arg2) == INTEGER_CST)
6825 /* We can replace A with C1 in this case. */
6826 arg1 = convert (type, TREE_OPERAND (arg0, 1));
6827 t = build (code, type, TREE_OPERAND (t, 0), arg1,
6828 TREE_OPERAND (t, 2));
6832 /* If C1 is C2 + 1, this is min(A, C2). */
6833 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
6834 && operand_equal_p (TREE_OPERAND (arg0, 1),
6835 const_binop (PLUS_EXPR, arg2,
6836 integer_one_node, 0), 1))
6837 return pedantic_non_lvalue
6838 (fold (build (MIN_EXPR, type, arg1, arg2)));
6842 /* If C1 is C2 - 1, this is min(A, C2). */
6843 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
6844 && operand_equal_p (TREE_OPERAND (arg0, 1),
6845 const_binop (MINUS_EXPR, arg2,
6846 integer_one_node, 0), 1))
6847 return pedantic_non_lvalue
6848 (fold (build (MIN_EXPR, type, arg1, arg2)));
6852 /* If C1 is C2 - 1, this is max(A, C2). */
6853 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
6854 && operand_equal_p (TREE_OPERAND (arg0, 1),
6855 const_binop (MINUS_EXPR, arg2,
6856 integer_one_node, 0), 1))
6857 return pedantic_non_lvalue
6858 (fold (build (MAX_EXPR, type, arg1, arg2)));
6862 /* If C1 is C2 + 1, this is max(A, C2). */
6863 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
6864 && operand_equal_p (TREE_OPERAND (arg0, 1),
6865 const_binop (PLUS_EXPR, arg2,
6866 integer_one_node, 0), 1))
6867 return pedantic_non_lvalue
6868 (fold (build (MAX_EXPR, type, arg1, arg2)));
6877 /* If the second operand is simpler than the third, swap them
6878 since that produces better jump optimization results. */
6879 if ((TREE_CONSTANT (arg1) || TREE_CODE_CLASS (TREE_CODE (arg1)) == 'd'
6880 || TREE_CODE (arg1) == SAVE_EXPR)
6881 && ! (TREE_CONSTANT (TREE_OPERAND (t, 2))
6882 || TREE_CODE_CLASS (TREE_CODE (TREE_OPERAND (t, 2))) == 'd'
6883 || TREE_CODE (TREE_OPERAND (t, 2)) == SAVE_EXPR))
6885 /* See if this can be inverted. If it can't, possibly because
6886 it was a floating-point inequality comparison, don't do
6888 tem = invert_truthvalue (arg0);
6890 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
6892 t = build (code, type, tem,
6893 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
6895 /* arg1 should be the first argument of the new T. */
6896 arg1 = TREE_OPERAND (t, 1);
6901 /* Convert A ? 1 : 0 to simply A. */
6902 if (integer_onep (TREE_OPERAND (t, 1))
6903 && integer_zerop (TREE_OPERAND (t, 2))
6904 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
6905 call to fold will try to move the conversion inside
6906 a COND, which will recurse. In that case, the COND_EXPR
6907 is probably the best choice, so leave it alone. */
6908 && type == TREE_TYPE (arg0))
6909 return pedantic_non_lvalue (arg0);
6911 /* Look for expressions of the form A & 2 ? 2 : 0. The result of this
6912 operation is simply A & 2. */
6914 if (integer_zerop (TREE_OPERAND (t, 2))
6915 && TREE_CODE (arg0) == NE_EXPR
6916 && integer_zerop (TREE_OPERAND (arg0, 1))
6917 && integer_pow2p (arg1)
6918 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
6919 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
6921 return pedantic_non_lvalue (convert (type, TREE_OPERAND (arg0, 0)));
6926 /* When pedantic, a compound expression can be neither an lvalue
6927 nor an integer constant expression. */
6928 if (TREE_SIDE_EFFECTS (arg0) || pedantic)
6930 /* Don't let (0, 0) be null pointer constant. */
6931 if (integer_zerop (arg1))
6932 return build1 (NOP_EXPR, TREE_TYPE (arg1), arg1);
6937 return build_complex (type, arg0, arg1);
6941 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
6943 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
6944 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
6945 TREE_OPERAND (arg0, 1));
6946 else if (TREE_CODE (arg0) == COMPLEX_CST)
6947 return TREE_REALPART (arg0);
6948 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
6949 return fold (build (TREE_CODE (arg0), type,
6950 fold (build1 (REALPART_EXPR, type,
6951 TREE_OPERAND (arg0, 0))),
6952 fold (build1 (REALPART_EXPR,
6953 type, TREE_OPERAND (arg0, 1)))));
6957 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
6958 return convert (type, integer_zero_node);
6959 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
6960 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
6961 TREE_OPERAND (arg0, 0));
6962 else if (TREE_CODE (arg0) == COMPLEX_CST)
6963 return TREE_IMAGPART (arg0);
6964 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
6965 return fold (build (TREE_CODE (arg0), type,
6966 fold (build1 (IMAGPART_EXPR, type,
6967 TREE_OPERAND (arg0, 0))),
6968 fold (build1 (IMAGPART_EXPR, type,
6969 TREE_OPERAND (arg0, 1)))));
6972 /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
6974 case CLEANUP_POINT_EXPR:
6975 if (! has_cleanups (arg0))
6976 return TREE_OPERAND (t, 0);
6979 enum tree_code code0 = TREE_CODE (arg0);
6980 int kind0 = TREE_CODE_CLASS (code0);
6981 tree arg00 = TREE_OPERAND (arg0, 0);
6984 if (kind0 == '1' || code0 == TRUTH_NOT_EXPR)
6985 return fold (build1 (code0, type,
6986 fold (build1 (CLEANUP_POINT_EXPR,
6987 TREE_TYPE (arg00), arg00))));
6989 if (kind0 == '<' || kind0 == '2'
6990 || code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR
6991 || code0 == TRUTH_AND_EXPR || code0 == TRUTH_OR_EXPR
6992 || code0 == TRUTH_XOR_EXPR)
6994 arg01 = TREE_OPERAND (arg0, 1);
6996 if (TREE_CONSTANT (arg00)
6997 || ((code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR)
6998 && ! has_cleanups (arg00)))
6999 return fold (build (code0, type, arg00,
7000 fold (build1 (CLEANUP_POINT_EXPR,
7001 TREE_TYPE (arg01), arg01))));
7003 if (TREE_CONSTANT (arg01))
7004 return fold (build (code0, type,
7005 fold (build1 (CLEANUP_POINT_EXPR,
7006 TREE_TYPE (arg00), arg00)),
7015 } /* switch (code) */
7018 /* Determine if first argument is a multiple of second argument. Return 0 if
7019 it is not, or we cannot easily determined it to be.
7021 An example of the sort of thing we care about (at this point; this routine
7022 could surely be made more general, and expanded to do what the *_DIV_EXPR's
7023 fold cases do now) is discovering that
7025 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7031 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
7033 This code also handles discovering that
7035 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7037 is a multiple of 8 so we don't have to worry about dealing with a
7040 Note that we *look* inside a SAVE_EXPR only to determine how it was
7041 calculated; it is not safe for fold to do much of anything else with the
7042 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
7043 at run time. For example, the latter example above *cannot* be implemented
7044 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
7045 evaluation time of the original SAVE_EXPR is not necessarily the same at
7046 the time the new expression is evaluated. The only optimization of this
7047 sort that would be valid is changing
7049 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
7053 SAVE_EXPR (I) * SAVE_EXPR (J)
7055 (where the same SAVE_EXPR (J) is used in the original and the
7056 transformed version). */
7059 multiple_of_p (type, top, bottom)
7064 if (operand_equal_p (top, bottom, 0))
7067 if (TREE_CODE (type) != INTEGER_TYPE)
7070 switch (TREE_CODE (top))
7073 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
7074 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
7078 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
7079 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
7082 /* Can't handle conversions from non-integral or wider integral type. */
7083 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
7084 || (TYPE_PRECISION (type)
7085 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
7088 /* .. fall through ... */
7091 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
7094 if ((TREE_CODE (bottom) != INTEGER_CST)
7095 || (tree_int_cst_sgn (top) < 0)
7096 || (tree_int_cst_sgn (bottom) < 0))
7098 return integer_zerop (const_binop (TRUNC_MOD_EXPR,