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. */
54 static void encode PROTO((HOST_WIDE_INT *,
55 HOST_WIDE_INT, HOST_WIDE_INT));
56 static void decode PROTO((HOST_WIDE_INT *,
57 HOST_WIDE_INT *, HOST_WIDE_INT *));
58 int div_and_round_double PROTO((enum tree_code, int, HOST_WIDE_INT,
59 HOST_WIDE_INT, HOST_WIDE_INT,
60 HOST_WIDE_INT, HOST_WIDE_INT *,
61 HOST_WIDE_INT *, HOST_WIDE_INT *,
63 static int split_tree PROTO((tree, enum tree_code, tree *,
65 static tree int_const_binop PROTO((enum tree_code, tree, tree, int, int));
66 static tree const_binop PROTO((enum tree_code, tree, tree, int));
67 static tree fold_convert PROTO((tree, tree));
68 static enum tree_code invert_tree_comparison PROTO((enum tree_code));
69 static enum tree_code swap_tree_comparison PROTO((enum tree_code));
70 static int truth_value_p PROTO((enum tree_code));
71 static int operand_equal_for_comparison_p PROTO((tree, tree, tree));
72 static int twoval_comparison_p PROTO((tree, tree *, tree *, int *));
73 static tree eval_subst PROTO((tree, tree, tree, tree, tree));
74 static tree omit_one_operand PROTO((tree, tree, tree));
75 static tree pedantic_omit_one_operand PROTO((tree, tree, tree));
76 static tree distribute_bit_expr PROTO((enum tree_code, tree, tree, tree));
77 static tree make_bit_field_ref PROTO((tree, tree, int, int, int));
78 static tree optimize_bit_field_compare PROTO((enum tree_code, tree,
80 static tree decode_field_reference PROTO((tree, int *, int *,
81 enum machine_mode *, int *,
82 int *, tree *, tree *));
83 static int all_ones_mask_p PROTO((tree, int));
84 static int simple_operand_p PROTO((tree));
85 static tree range_binop PROTO((enum tree_code, tree, tree, int,
87 static tree make_range PROTO((tree, int *, tree *, tree *));
88 static tree build_range_check PROTO((tree, tree, int, tree, tree));
89 static int merge_ranges PROTO((int *, tree *, tree *, int, tree, tree,
91 static tree fold_range_test PROTO((tree));
92 static tree unextend PROTO((tree, int, int, tree));
93 static tree fold_truthop PROTO((enum tree_code, tree, tree, tree));
94 static tree strip_compound_expr PROTO((tree, tree));
95 static int multiple_of_p PROTO((tree, tree, tree));
96 static tree constant_boolean_node PROTO((int, tree));
97 static int count_cond PROTO((tree, int));
98 static void const_binop_1 PROTO((PTR));
99 static void fold_convert_1 PROTO((PTR));
102 #define BRANCH_COST 1
105 /* Suppose A1 + B1 = SUM1, using 2's complement arithmetic ignoring overflow.
106 Suppose A, B and SUM have the same respective signs as A1, B1, and SUM1.
107 Then this yields nonzero if overflow occurred during the addition.
108 Overflow occurs if A and B have the same sign, but A and SUM differ in sign.
109 Use `^' to test whether signs differ, and `< 0' to isolate the sign. */
110 #define overflow_sum_sign(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
112 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
113 We do that by representing the two-word integer in 4 words, with only
114 HOST_BITS_PER_WIDE_INT/2 bits stored in each word, as a positive number. */
117 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT/2)) - 1))
118 #define HIGHPART(x) \
119 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT/2)
120 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT/2)
122 /* Unpack a two-word integer into 4 words.
123 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
124 WORDS points to the array of HOST_WIDE_INTs. */
127 encode (words, low, hi)
128 HOST_WIDE_INT *words;
129 HOST_WIDE_INT low, hi;
131 words[0] = LOWPART (low);
132 words[1] = HIGHPART (low);
133 words[2] = LOWPART (hi);
134 words[3] = HIGHPART (hi);
137 /* Pack an array of 4 words into a two-word integer.
138 WORDS points to the array of words.
139 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
142 decode (words, low, hi)
143 HOST_WIDE_INT *words;
144 HOST_WIDE_INT *low, *hi;
146 *low = words[0] | words[1] * BASE;
147 *hi = words[2] | words[3] * BASE;
150 /* Make the integer constant T valid for its type
151 by setting to 0 or 1 all the bits in the constant
152 that don't belong in the type.
153 Yield 1 if a signed overflow occurs, 0 otherwise.
154 If OVERFLOW is nonzero, a signed overflow has already occurred
155 in calculating T, so propagate it.
157 Make the real constant T valid for its type by calling CHECK_FLOAT_VALUE,
161 force_fit_type (t, overflow)
165 HOST_WIDE_INT low, high;
168 if (TREE_CODE (t) == REAL_CST)
170 #ifdef CHECK_FLOAT_VALUE
171 CHECK_FLOAT_VALUE (TYPE_MODE (TREE_TYPE (t)), TREE_REAL_CST (t),
177 else if (TREE_CODE (t) != INTEGER_CST)
180 low = TREE_INT_CST_LOW (t);
181 high = TREE_INT_CST_HIGH (t);
183 if (POINTER_TYPE_P (TREE_TYPE (t)))
186 prec = TYPE_PRECISION (TREE_TYPE (t));
188 /* First clear all bits that are beyond the type's precision. */
190 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
192 else if (prec > HOST_BITS_PER_WIDE_INT)
194 TREE_INT_CST_HIGH (t)
195 &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
199 TREE_INT_CST_HIGH (t) = 0;
200 if (prec < HOST_BITS_PER_WIDE_INT)
201 TREE_INT_CST_LOW (t) &= ~((HOST_WIDE_INT) (-1) << prec);
204 /* Unsigned types do not suffer sign extension or overflow. */
205 if (TREE_UNSIGNED (TREE_TYPE (t)))
208 /* If the value's sign bit is set, extend the sign. */
209 if (prec != 2 * HOST_BITS_PER_WIDE_INT
210 && (prec > HOST_BITS_PER_WIDE_INT
211 ? (TREE_INT_CST_HIGH (t)
212 & ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)))
213 : TREE_INT_CST_LOW (t) & ((HOST_WIDE_INT) 1 << (prec - 1))))
215 /* Value is negative:
216 set to 1 all the bits that are outside this type's precision. */
217 if (prec > HOST_BITS_PER_WIDE_INT)
219 TREE_INT_CST_HIGH (t)
220 |= ((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
224 TREE_INT_CST_HIGH (t) = -1;
225 if (prec < HOST_BITS_PER_WIDE_INT)
226 TREE_INT_CST_LOW (t) |= ((HOST_WIDE_INT) (-1) << prec);
230 /* Yield nonzero if signed overflow occurred. */
232 ((overflow | (low ^ TREE_INT_CST_LOW (t)) | (high ^ TREE_INT_CST_HIGH (t)))
236 /* Add two doubleword integers with doubleword result.
237 Each argument is given as two `HOST_WIDE_INT' pieces.
238 One argument is L1 and H1; the other, L2 and H2.
239 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
242 add_double (l1, h1, l2, h2, lv, hv)
243 HOST_WIDE_INT l1, h1, l2, h2;
244 HOST_WIDE_INT *lv, *hv;
249 h = h1 + h2 + ((unsigned HOST_WIDE_INT) l < l1);
253 return overflow_sum_sign (h1, h2, h);
256 /* Negate a doubleword integer with doubleword result.
257 Return nonzero if the operation overflows, assuming it's signed.
258 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
259 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
262 neg_double (l1, h1, lv, hv)
263 HOST_WIDE_INT l1, h1;
264 HOST_WIDE_INT *lv, *hv;
270 return (*hv & h1) < 0;
280 /* Multiply two doubleword integers with doubleword result.
281 Return nonzero if the operation overflows, assuming it's signed.
282 Each argument is given as two `HOST_WIDE_INT' pieces.
283 One argument is L1 and H1; the other, L2 and H2.
284 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
287 mul_double (l1, h1, l2, h2, lv, hv)
288 HOST_WIDE_INT l1, h1, l2, h2;
289 HOST_WIDE_INT *lv, *hv;
291 HOST_WIDE_INT arg1[4];
292 HOST_WIDE_INT arg2[4];
293 HOST_WIDE_INT prod[4 * 2];
294 register unsigned HOST_WIDE_INT carry;
295 register int i, j, k;
296 HOST_WIDE_INT toplow, tophigh, neglow, neghigh;
298 encode (arg1, l1, h1);
299 encode (arg2, l2, h2);
301 bzero ((char *) prod, sizeof prod);
303 for (i = 0; i < 4; i++)
306 for (j = 0; j < 4; j++)
309 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
310 carry += arg1[i] * arg2[j];
311 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
313 prod[k] = LOWPART (carry);
314 carry = HIGHPART (carry);
319 decode (prod, lv, hv); /* This ignores prod[4] through prod[4*2-1] */
321 /* Check for overflow by calculating the top half of the answer in full;
322 it should agree with the low half's sign bit. */
323 decode (prod+4, &toplow, &tophigh);
326 neg_double (l2, h2, &neglow, &neghigh);
327 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
331 neg_double (l1, h1, &neglow, &neghigh);
332 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
334 return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
337 /* Shift the doubleword integer in L1, H1 left by COUNT places
338 keeping only PREC bits of result.
339 Shift right if COUNT is negative.
340 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
341 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
344 lshift_double (l1, h1, count, prec, lv, hv, arith)
345 HOST_WIDE_INT l1, h1, count;
347 HOST_WIDE_INT *lv, *hv;
352 rshift_double (l1, h1, - count, prec, lv, hv, arith);
356 #ifdef SHIFT_COUNT_TRUNCATED
357 if (SHIFT_COUNT_TRUNCATED)
361 if (count >= HOST_BITS_PER_WIDE_INT)
363 *hv = (unsigned HOST_WIDE_INT) l1 << (count - HOST_BITS_PER_WIDE_INT);
368 *hv = (((unsigned HOST_WIDE_INT) h1 << count)
369 | ((unsigned HOST_WIDE_INT) l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
370 *lv = (unsigned HOST_WIDE_INT) l1 << count;
374 /* Shift the doubleword integer in L1, H1 right by COUNT places
375 keeping only PREC bits of result. COUNT must be positive.
376 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
377 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
380 rshift_double (l1, h1, count, prec, lv, hv, arith)
381 HOST_WIDE_INT l1, h1, count;
382 int prec ATTRIBUTE_UNUSED;
383 HOST_WIDE_INT *lv, *hv;
386 unsigned HOST_WIDE_INT signmask;
388 ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
391 #ifdef SHIFT_COUNT_TRUNCATED
392 if (SHIFT_COUNT_TRUNCATED)
396 if (count >= HOST_BITS_PER_WIDE_INT)
399 *lv = ((signmask << (2 * HOST_BITS_PER_WIDE_INT - count - 1) << 1)
400 | ((unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT)));
404 *lv = (((unsigned HOST_WIDE_INT) l1 >> count)
405 | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
406 *hv = ((signmask << (HOST_BITS_PER_WIDE_INT - count))
407 | ((unsigned HOST_WIDE_INT) h1 >> count));
411 /* Rotate the doubleword integer in L1, H1 left by COUNT places
412 keeping only PREC bits of result.
413 Rotate right if COUNT is negative.
414 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
417 lrotate_double (l1, h1, count, prec, lv, hv)
418 HOST_WIDE_INT l1, h1, count;
420 HOST_WIDE_INT *lv, *hv;
422 HOST_WIDE_INT s1l, s1h, s2l, s2h;
428 lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
429 rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
434 /* Rotate the doubleword integer in L1, H1 left by COUNT places
435 keeping only PREC bits of result. COUNT must be positive.
436 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
439 rrotate_double (l1, h1, count, prec, lv, hv)
440 HOST_WIDE_INT l1, h1, count;
442 HOST_WIDE_INT *lv, *hv;
444 HOST_WIDE_INT s1l, s1h, s2l, s2h;
450 rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
451 lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
456 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
457 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
458 CODE is a tree code for a kind of division, one of
459 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
461 It controls how the quotient is rounded to a integer.
462 Return nonzero if the operation overflows.
463 UNS nonzero says do unsigned division. */
466 div_and_round_double (code, uns,
467 lnum_orig, hnum_orig, lden_orig, hden_orig,
468 lquo, hquo, lrem, hrem)
471 HOST_WIDE_INT lnum_orig, hnum_orig; /* num == numerator == dividend */
472 HOST_WIDE_INT lden_orig, hden_orig; /* den == denominator == divisor */
473 HOST_WIDE_INT *lquo, *hquo, *lrem, *hrem;
476 HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
477 HOST_WIDE_INT den[4], quo[4];
479 unsigned HOST_WIDE_INT work;
480 register unsigned HOST_WIDE_INT carry = 0;
481 HOST_WIDE_INT lnum = lnum_orig;
482 HOST_WIDE_INT hnum = hnum_orig;
483 HOST_WIDE_INT lden = lden_orig;
484 HOST_WIDE_INT hden = hden_orig;
487 if ((hden == 0) && (lden == 0))
488 overflow = 1, lden = 1;
490 /* calculate quotient sign and convert operands to unsigned. */
496 /* (minimum integer) / (-1) is the only overflow case. */
497 if (neg_double (lnum, hnum, &lnum, &hnum) && (lden & hden) == -1)
503 neg_double (lden, hden, &lden, &hden);
507 if (hnum == 0 && hden == 0)
508 { /* single precision */
510 /* This unsigned division rounds toward zero. */
511 *lquo = lnum / (unsigned HOST_WIDE_INT) lden;
516 { /* trivial case: dividend < divisor */
517 /* hden != 0 already checked. */
524 bzero ((char *) quo, sizeof quo);
526 bzero ((char *) num, sizeof num); /* to zero 9th element */
527 bzero ((char *) den, sizeof den);
529 encode (num, lnum, hnum);
530 encode (den, lden, hden);
532 /* Special code for when the divisor < BASE. */
533 if (hden == 0 && lden < (HOST_WIDE_INT) BASE)
535 /* hnum != 0 already checked. */
536 for (i = 4 - 1; i >= 0; i--)
538 work = num[i] + carry * BASE;
539 quo[i] = work / (unsigned HOST_WIDE_INT) lden;
540 carry = work % (unsigned HOST_WIDE_INT) lden;
545 /* Full double precision division,
546 with thanks to Don Knuth's "Seminumerical Algorithms". */
547 int num_hi_sig, den_hi_sig;
548 unsigned HOST_WIDE_INT quo_est, scale;
550 /* Find the highest non-zero divisor digit. */
551 for (i = 4 - 1; ; i--)
557 /* Insure that the first digit of the divisor is at least BASE/2.
558 This is required by the quotient digit estimation algorithm. */
560 scale = BASE / (den[den_hi_sig] + 1);
561 if (scale > 1) { /* scale divisor and dividend */
563 for (i = 0; i <= 4 - 1; i++) {
564 work = (num[i] * scale) + carry;
565 num[i] = LOWPART (work);
566 carry = HIGHPART (work);
569 for (i = 0; i <= 4 - 1; i++) {
570 work = (den[i] * scale) + carry;
571 den[i] = LOWPART (work);
572 carry = HIGHPART (work);
573 if (den[i] != 0) den_hi_sig = i;
580 for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--) {
581 /* guess the next quotient digit, quo_est, by dividing the first
582 two remaining dividend digits by the high order quotient digit.
583 quo_est is never low and is at most 2 high. */
584 unsigned HOST_WIDE_INT tmp;
586 num_hi_sig = i + den_hi_sig + 1;
587 work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
588 if (num[num_hi_sig] != den[den_hi_sig])
589 quo_est = work / den[den_hi_sig];
593 /* refine quo_est so it's usually correct, and at most one high. */
594 tmp = work - quo_est * den[den_hi_sig];
596 && den[den_hi_sig - 1] * quo_est > (tmp * BASE + num[num_hi_sig - 2]))
599 /* Try QUO_EST as the quotient digit, by multiplying the
600 divisor by QUO_EST and subtracting from the remaining dividend.
601 Keep in mind that QUO_EST is the I - 1st digit. */
604 for (j = 0; j <= den_hi_sig; j++)
606 work = quo_est * den[j] + carry;
607 carry = HIGHPART (work);
608 work = num[i + j] - LOWPART (work);
609 num[i + j] = LOWPART (work);
610 carry += HIGHPART (work) != 0;
613 /* if quo_est was high by one, then num[i] went negative and
614 we need to correct things. */
616 if (num[num_hi_sig] < carry)
619 carry = 0; /* add divisor back in */
620 for (j = 0; j <= den_hi_sig; j++)
622 work = num[i + j] + den[j] + carry;
623 carry = HIGHPART (work);
624 num[i + j] = LOWPART (work);
626 num [num_hi_sig] += carry;
629 /* store the quotient digit. */
634 decode (quo, lquo, hquo);
637 /* if result is negative, make it so. */
639 neg_double (*lquo, *hquo, lquo, hquo);
641 /* compute trial remainder: rem = num - (quo * den) */
642 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
643 neg_double (*lrem, *hrem, lrem, hrem);
644 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
649 case TRUNC_MOD_EXPR: /* round toward zero */
650 case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
654 case FLOOR_MOD_EXPR: /* round toward negative infinity */
655 if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
658 add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
661 else return overflow;
665 case CEIL_MOD_EXPR: /* round toward positive infinity */
666 if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
668 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
671 else return overflow;
675 case ROUND_MOD_EXPR: /* round to closest integer */
677 HOST_WIDE_INT labs_rem = *lrem, habs_rem = *hrem;
678 HOST_WIDE_INT labs_den = lden, habs_den = hden, ltwice, htwice;
680 /* get absolute values */
681 if (*hrem < 0) neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
682 if (hden < 0) neg_double (lden, hden, &labs_den, &habs_den);
684 /* if (2 * abs (lrem) >= abs (lden)) */
685 mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
686 labs_rem, habs_rem, <wice, &htwice);
687 if (((unsigned HOST_WIDE_INT) habs_den
688 < (unsigned HOST_WIDE_INT) htwice)
689 || (((unsigned HOST_WIDE_INT) habs_den
690 == (unsigned HOST_WIDE_INT) htwice)
691 && ((HOST_WIDE_INT unsigned) labs_den
692 < (unsigned HOST_WIDE_INT) ltwice)))
696 add_double (*lquo, *hquo,
697 (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
700 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
703 else return overflow;
711 /* compute true remainder: rem = num - (quo * den) */
712 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
713 neg_double (*lrem, *hrem, lrem, hrem);
714 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
718 #ifndef REAL_ARITHMETIC
719 /* Effectively truncate a real value to represent the nearest possible value
720 in a narrower mode. The result is actually represented in the same data
721 type as the argument, but its value is usually different.
723 A trap may occur during the FP operations and it is the responsibility
724 of the calling function to have a handler established. */
727 real_value_truncate (mode, arg)
728 enum machine_mode mode;
731 return REAL_VALUE_TRUNCATE (mode, arg);
734 #if TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
736 /* Check for infinity in an IEEE double precision number. */
742 /* The IEEE 64-bit double format. */
747 unsigned exponent : 11;
748 unsigned mantissa1 : 20;
753 unsigned mantissa1 : 20;
754 unsigned exponent : 11;
760 if (u.big_endian.sign == 1)
763 return (u.big_endian.exponent == 2047
764 && u.big_endian.mantissa1 == 0
765 && u.big_endian.mantissa2 == 0);
770 return (u.little_endian.exponent == 2047
771 && u.little_endian.mantissa1 == 0
772 && u.little_endian.mantissa2 == 0);
776 /* Check whether an IEEE double precision number is a NaN. */
782 /* The IEEE 64-bit double format. */
787 unsigned exponent : 11;
788 unsigned mantissa1 : 20;
793 unsigned mantissa1 : 20;
794 unsigned exponent : 11;
800 if (u.big_endian.sign == 1)
803 return (u.big_endian.exponent == 2047
804 && (u.big_endian.mantissa1 != 0
805 || u.big_endian.mantissa2 != 0));
810 return (u.little_endian.exponent == 2047
811 && (u.little_endian.mantissa1 != 0
812 || u.little_endian.mantissa2 != 0));
816 /* Check for a negative IEEE double precision number. */
822 /* The IEEE 64-bit double format. */
827 unsigned exponent : 11;
828 unsigned mantissa1 : 20;
833 unsigned mantissa1 : 20;
834 unsigned exponent : 11;
840 if (u.big_endian.sign == 1)
843 return u.big_endian.sign;
848 return u.little_endian.sign;
851 #else /* Target not IEEE */
853 /* Let's assume other float formats don't have infinity.
854 (This can be overridden by redefining REAL_VALUE_ISINF.) */
862 /* Let's assume other float formats don't have NaNs.
863 (This can be overridden by redefining REAL_VALUE_ISNAN.) */
871 /* Let's assume other float formats don't have minus zero.
872 (This can be overridden by redefining REAL_VALUE_NEGATIVE.) */
879 #endif /* Target not IEEE */
881 /* Try to change R into its exact multiplicative inverse in machine mode
882 MODE. Return nonzero function value if successful. */
885 exact_real_inverse (mode, r)
886 enum machine_mode mode;
897 /* Usually disable if bounds checks are not reliable. */
898 if ((HOST_FLOAT_FORMAT != TARGET_FLOAT_FORMAT) && !flag_pretend_float)
901 /* Set array index to the less significant bits in the unions, depending
902 on the endian-ness of the host doubles.
903 Disable if insufficient information on the data structure. */
904 #if HOST_FLOAT_FORMAT == UNKNOWN_FLOAT_FORMAT
907 #if HOST_FLOAT_FORMAT == VAX_FLOAT_FORMAT
910 #if HOST_FLOAT_FORMAT == IBM_FLOAT_FORMAT
913 #define K (2 * HOST_FLOAT_WORDS_BIG_ENDIAN)
918 if (setjmp (float_error))
920 /* Don't do the optimization if there was an arithmetic error. */
922 set_float_handler (NULL_PTR);
925 set_float_handler (float_error);
927 /* Domain check the argument. */
933 if (REAL_VALUE_ISINF (x.d) || REAL_VALUE_ISNAN (x.d))
937 /* Compute the reciprocal and check for numerical exactness.
938 It is unnecessary to check all the significand bits to determine
939 whether X is a power of 2. If X is not, then it is impossible for
940 the bottom half significand of both X and 1/X to be all zero bits.
941 Hence we ignore the data structure of the top half and examine only
942 the low order bits of the two significands. */
944 if (x.i[K] != 0 || x.i[K + 1] != 0 || t.i[K] != 0 || t.i[K + 1] != 0)
947 /* Truncate to the required mode and range-check the result. */
948 y.d = REAL_VALUE_TRUNCATE (mode, t.d);
949 #ifdef CHECK_FLOAT_VALUE
951 if (CHECK_FLOAT_VALUE (mode, y.d, i))
955 /* Fail if truncation changed the value. */
956 if (y.d != t.d || y.d == 0.0)
960 if (REAL_VALUE_ISINF (y.d) || REAL_VALUE_ISNAN (y.d))
964 /* Output the reciprocal and return success flag. */
965 set_float_handler (NULL_PTR);
971 /* Convert C9X hexadecimal floating point string constant S. Return
972 real value type in mode MODE. This function uses the host computer's
973 fp arithmetic when there is no REAL_ARITHMETIC. */
976 real_hex_to_f (s, mode)
978 enum machine_mode mode;
982 unsigned HOST_WIDE_INT low, high;
983 int frexpon, expon, shcount, nrmcount, k;
984 int sign, expsign, decpt, isfloat, isldouble, gotp, lost;
994 while (*p == ' ' || *p == '\t')
997 /* Sign, if any, comes first. */
1005 /* The string is supposed to start with 0x or 0X . */
1009 if (*p == 'x' || *p == 'X')
1022 lost = 0; /* Nonzero low order bits shifted out and discarded. */
1023 frexpon = 0; /* Bits after the decimal point. */
1024 expon = 0; /* Value of exponent. */
1025 decpt = 0; /* How many decimal points. */
1026 gotp = 0; /* How many P's. */
1028 while ((c = *p) != '\0')
1030 if ((c >= '0' && c <= '9') || (c >= 'A' && c <= 'F')
1031 || (c >= 'a' && c <= 'f'))
1041 if ((high & 0xf0000000) == 0)
1043 high = (high << 4) + ((low >> 28) & 15);
1044 low = (low << 4) + k;
1051 /* Record nonzero lost bits. */
1063 else if (c == 'p' || c == 'P')
1067 /* Sign of exponent. */
1073 /* Value of exponent.
1074 The exponent field is a decimal integer. */
1077 k = (*p++ & 0x7f) - '0';
1078 expon = 10 * expon + k;
1081 /* F suffix is ambiguous in the significand part
1082 so it must appear after the decimal exponent field. */
1083 if (*p == 'f' || *p == 'F')
1090 else if (c == 'l' || c == 'L')
1099 /* Abort if last character read was not legitimate. */
1101 if ((c != '\0' && c != ' ' && c != '\n' && c != '\r') || (decpt > 1))
1103 /* There must be either one decimal point or one p. */
1104 if (decpt == 0 && gotp == 0)
1107 if ((high == 0) && (low == 0))
1120 /* Leave a high guard bit for carry-out. */
1121 if ((high & 0x80000000) != 0)
1124 low = (low >> 1) | (high << 31);
1128 if ((high & 0xffff8000) == 0)
1130 high = (high << 16) + ((low >> 16) & 0xffff);
1134 while ((high & 0xc0000000) == 0)
1136 high = (high << 1) + ((low >> 31) & 1);
1140 if (isfloat || GET_MODE_SIZE(mode) == UNITS_PER_WORD)
1142 /* Keep 24 bits precision, bits 0x7fffff80.
1143 Rounding bit is 0x40. */
1144 lost = lost | low | (high & 0x3f);
1148 if ((high & 0x80) || lost)
1155 /* We need real.c to do long double formats, so here default
1156 to double precision. */
1157 #if HOST_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
1159 Keep 53 bits precision, bits 0x7fffffff fffffc00.
1160 Rounding bit is low word 0x200. */
1161 lost = lost | (low & 0x1ff);
1164 if ((low & 0x400) || lost)
1166 low = (low + 0x200) & 0xfffffc00;
1173 /* Assume it's a VAX with 56-bit significand,
1174 bits 0x7fffffff ffffff80. */
1175 lost = lost | (low & 0x7f);
1178 if ((low & 0x80) || lost)
1180 low = (low + 0x40) & 0xffffff80;
1189 ip = REAL_VALUE_LDEXP (ip, 32) + (double) low;
1190 /* Apply shifts and exponent value as power of 2. */
1191 ip = REAL_VALUE_LDEXP (ip, expon - (nrmcount + frexpon));
1198 #endif /* no REAL_ARITHMETIC */
1200 /* Split a tree IN into a constant and a variable part
1201 that could be combined with CODE to make IN.
1202 CODE must be a commutative arithmetic operation.
1203 Store the constant part into *CONP and the variable in &VARP.
1204 Return 1 if this was done; zero means the tree IN did not decompose
1207 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR.
1208 Therefore, we must tell the caller whether the variable part
1209 was subtracted. We do this by storing 1 or -1 into *VARSIGNP.
1210 The value stored is the coefficient for the variable term.
1211 The constant term we return should always be added;
1212 we negate it if necessary. */
1215 split_tree (in, code, varp, conp, varsignp)
1217 enum tree_code code;
1221 register tree outtype = TREE_TYPE (in);
1225 /* Strip any conversions that don't change the machine mode. */
1226 while ((TREE_CODE (in) == NOP_EXPR
1227 || TREE_CODE (in) == CONVERT_EXPR)
1228 && (TYPE_MODE (TREE_TYPE (in))
1229 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (in, 0)))))
1230 in = TREE_OPERAND (in, 0);
1232 if (TREE_CODE (in) == code
1233 || (! FLOAT_TYPE_P (TREE_TYPE (in))
1234 /* We can associate addition and subtraction together
1235 (even though the C standard doesn't say so)
1236 for integers because the value is not affected.
1237 For reals, the value might be affected, so we can't. */
1238 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
1239 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
1241 enum tree_code code = TREE_CODE (TREE_OPERAND (in, 0));
1242 if (code == INTEGER_CST)
1244 *conp = TREE_OPERAND (in, 0);
1245 *varp = TREE_OPERAND (in, 1);
1246 if (TYPE_MODE (TREE_TYPE (*varp)) != TYPE_MODE (outtype)
1247 && TREE_TYPE (*varp) != outtype)
1248 *varp = convert (outtype, *varp);
1249 *varsignp = (TREE_CODE (in) == MINUS_EXPR) ? -1 : 1;
1252 if (TREE_CONSTANT (TREE_OPERAND (in, 1)))
1254 *conp = TREE_OPERAND (in, 1);
1255 *varp = TREE_OPERAND (in, 0);
1257 if (TYPE_MODE (TREE_TYPE (*varp)) != TYPE_MODE (outtype)
1258 && TREE_TYPE (*varp) != outtype)
1259 *varp = convert (outtype, *varp);
1260 if (TREE_CODE (in) == MINUS_EXPR)
1262 /* If operation is subtraction and constant is second,
1263 must negate it to get an additive constant.
1264 And this cannot be done unless it is a manifest constant.
1265 It could also be the address of a static variable.
1266 We cannot negate that, so give up. */
1267 if (TREE_CODE (*conp) == INTEGER_CST)
1268 /* Subtracting from integer_zero_node loses for long long. */
1269 *conp = fold (build1 (NEGATE_EXPR, TREE_TYPE (*conp), *conp));
1275 if (TREE_CONSTANT (TREE_OPERAND (in, 0)))
1277 *conp = TREE_OPERAND (in, 0);
1278 *varp = TREE_OPERAND (in, 1);
1279 if (TYPE_MODE (TREE_TYPE (*varp)) != TYPE_MODE (outtype)
1280 && TREE_TYPE (*varp) != outtype)
1281 *varp = convert (outtype, *varp);
1282 *varsignp = (TREE_CODE (in) == MINUS_EXPR) ? -1 : 1;
1289 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1290 to produce a new constant.
1292 If NOTRUNC is nonzero, do not truncate the result to fit the data type.
1293 If FORSIZE is nonzero, compute overflow for unsigned types. */
1296 int_const_binop (code, arg1, arg2, notrunc, forsize)
1297 enum tree_code code;
1298 register tree arg1, arg2;
1299 int notrunc, forsize;
1301 HOST_WIDE_INT int1l, int1h, int2l, int2h;
1302 HOST_WIDE_INT low, hi;
1303 HOST_WIDE_INT garbagel, garbageh;
1305 int uns = TREE_UNSIGNED (TREE_TYPE (arg1));
1307 int no_overflow = 0;
1309 int1l = TREE_INT_CST_LOW (arg1);
1310 int1h = TREE_INT_CST_HIGH (arg1);
1311 int2l = TREE_INT_CST_LOW (arg2);
1312 int2h = TREE_INT_CST_HIGH (arg2);
1317 low = int1l | int2l, hi = int1h | int2h;
1321 low = int1l ^ int2l, hi = int1h ^ int2h;
1325 low = int1l & int2l, hi = int1h & int2h;
1328 case BIT_ANDTC_EXPR:
1329 low = int1l & ~int2l, hi = int1h & ~int2h;
1335 /* It's unclear from the C standard whether shifts can overflow.
1336 The following code ignores overflow; perhaps a C standard
1337 interpretation ruling is needed. */
1338 lshift_double (int1l, int1h, int2l,
1339 TYPE_PRECISION (TREE_TYPE (arg1)),
1348 lrotate_double (int1l, int1h, int2l,
1349 TYPE_PRECISION (TREE_TYPE (arg1)),
1354 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1358 neg_double (int2l, int2h, &low, &hi);
1359 add_double (int1l, int1h, low, hi, &low, &hi);
1360 overflow = overflow_sum_sign (hi, int2h, int1h);
1364 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1367 case TRUNC_DIV_EXPR:
1368 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1369 case EXACT_DIV_EXPR:
1370 /* This is a shortcut for a common special case. */
1371 if (int2h == 0 && int2l > 0
1372 && ! TREE_CONSTANT_OVERFLOW (arg1)
1373 && ! TREE_CONSTANT_OVERFLOW (arg2)
1374 && int1h == 0 && int1l >= 0)
1376 if (code == CEIL_DIV_EXPR)
1378 low = int1l / int2l, hi = 0;
1382 /* ... fall through ... */
1384 case ROUND_DIV_EXPR:
1385 if (int2h == 0 && int2l == 1)
1387 low = int1l, hi = int1h;
1390 if (int1l == int2l && int1h == int2h
1391 && ! (int1l == 0 && int1h == 0))
1396 overflow = div_and_round_double (code, uns,
1397 int1l, int1h, int2l, int2h,
1398 &low, &hi, &garbagel, &garbageh);
1401 case TRUNC_MOD_EXPR:
1402 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1403 /* This is a shortcut for a common special case. */
1404 if (int2h == 0 && int2l > 0
1405 && ! TREE_CONSTANT_OVERFLOW (arg1)
1406 && ! TREE_CONSTANT_OVERFLOW (arg2)
1407 && int1h == 0 && int1l >= 0)
1409 if (code == CEIL_MOD_EXPR)
1411 low = int1l % int2l, hi = 0;
1415 /* ... fall through ... */
1417 case ROUND_MOD_EXPR:
1418 overflow = div_and_round_double (code, uns,
1419 int1l, int1h, int2l, int2h,
1420 &garbagel, &garbageh, &low, &hi);
1427 low = (((unsigned HOST_WIDE_INT) int1h
1428 < (unsigned HOST_WIDE_INT) int2h)
1429 || (((unsigned HOST_WIDE_INT) int1h
1430 == (unsigned HOST_WIDE_INT) int2h)
1431 && ((unsigned HOST_WIDE_INT) int1l
1432 < (unsigned HOST_WIDE_INT) int2l)));
1436 low = ((int1h < int2h)
1437 || ((int1h == int2h)
1438 && ((unsigned HOST_WIDE_INT) int1l
1439 < (unsigned HOST_WIDE_INT) int2l)));
1441 if (low == (code == MIN_EXPR))
1442 low = int1l, hi = int1h;
1444 low = int2l, hi = int2h;
1451 if (TREE_TYPE (arg1) == sizetype && hi == 0
1453 && (TYPE_MAX_VALUE (sizetype) == NULL
1454 || low <= TREE_INT_CST_LOW (TYPE_MAX_VALUE (sizetype)))
1456 && ! TREE_OVERFLOW (arg1) && ! TREE_OVERFLOW (arg2))
1460 t = build_int_2 (low, hi);
1461 TREE_TYPE (t) = TREE_TYPE (arg1);
1465 = ((notrunc ? (!uns || forsize) && overflow
1466 : force_fit_type (t, (!uns || forsize) && overflow) && ! no_overflow)
1467 | TREE_OVERFLOW (arg1)
1468 | TREE_OVERFLOW (arg2));
1469 /* If we're doing a size calculation, unsigned arithmetic does overflow.
1470 So check if force_fit_type truncated the value. */
1472 && ! TREE_OVERFLOW (t)
1473 && (TREE_INT_CST_HIGH (t) != hi
1474 || TREE_INT_CST_LOW (t) != low))
1475 TREE_OVERFLOW (t) = 1;
1476 TREE_CONSTANT_OVERFLOW (t) = (TREE_OVERFLOW (t)
1477 | TREE_CONSTANT_OVERFLOW (arg1)
1478 | TREE_CONSTANT_OVERFLOW (arg2));
1486 REAL_VALUE_TYPE d1, d2;
1487 enum tree_code code;
1493 const_binop_1 (data)
1496 struct cb_args * args = (struct cb_args *) data;
1497 REAL_VALUE_TYPE value;
1499 #ifdef REAL_ARITHMETIC
1500 REAL_ARITHMETIC (value, args->code, args->d1, args->d2);
1505 value = args->d1 + args->d2;
1509 value = args->d1 - args->d2;
1513 value = args->d1 * args->d2;
1517 #ifndef REAL_INFINITY
1522 value = args->d1 / args->d2;
1526 value = MIN (args->d1, args->d2);
1530 value = MAX (args->d1, args->d2);
1536 #endif /* no REAL_ARITHMETIC */
1538 build_real (TREE_TYPE (args->arg1),
1539 real_value_truncate (TYPE_MODE (TREE_TYPE (args->arg1)),
1543 /* Combine two constants ARG1 and ARG2 under operation CODE
1544 to produce a new constant.
1545 We assume ARG1 and ARG2 have the same data type,
1546 or at least are the same kind of constant and the same machine mode.
1548 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1551 const_binop (code, arg1, arg2, notrunc)
1552 enum tree_code code;
1553 register tree arg1, arg2;
1556 STRIP_NOPS (arg1); STRIP_NOPS (arg2);
1558 if (TREE_CODE (arg1) == INTEGER_CST)
1559 return int_const_binop (code, arg1, arg2, notrunc, 0);
1561 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1562 if (TREE_CODE (arg1) == REAL_CST)
1568 struct cb_args args;
1570 d1 = TREE_REAL_CST (arg1);
1571 d2 = TREE_REAL_CST (arg2);
1573 /* If either operand is a NaN, just return it. Otherwise, set up
1574 for floating-point trap; we return an overflow. */
1575 if (REAL_VALUE_ISNAN (d1))
1577 else if (REAL_VALUE_ISNAN (d2))
1580 /* Setup input for const_binop_1() */
1586 if (do_float_handler (const_binop_1, (PTR) &args))
1588 /* Receive output from const_binop_1() */
1593 /* We got an exception from const_binop_1() */
1594 t = copy_node (arg1);
1599 = (force_fit_type (t, overflow)
1600 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
1601 TREE_CONSTANT_OVERFLOW (t)
1603 | TREE_CONSTANT_OVERFLOW (arg1)
1604 | TREE_CONSTANT_OVERFLOW (arg2);
1607 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
1608 if (TREE_CODE (arg1) == COMPLEX_CST)
1610 register tree type = TREE_TYPE (arg1);
1611 register tree r1 = TREE_REALPART (arg1);
1612 register tree i1 = TREE_IMAGPART (arg1);
1613 register tree r2 = TREE_REALPART (arg2);
1614 register tree i2 = TREE_IMAGPART (arg2);
1620 t = build_complex (type,
1621 const_binop (PLUS_EXPR, r1, r2, notrunc),
1622 const_binop (PLUS_EXPR, i1, i2, notrunc));
1626 t = build_complex (type,
1627 const_binop (MINUS_EXPR, r1, r2, notrunc),
1628 const_binop (MINUS_EXPR, i1, i2, notrunc));
1632 t = build_complex (type,
1633 const_binop (MINUS_EXPR,
1634 const_binop (MULT_EXPR,
1636 const_binop (MULT_EXPR,
1639 const_binop (PLUS_EXPR,
1640 const_binop (MULT_EXPR,
1642 const_binop (MULT_EXPR,
1649 register tree magsquared
1650 = const_binop (PLUS_EXPR,
1651 const_binop (MULT_EXPR, r2, r2, notrunc),
1652 const_binop (MULT_EXPR, i2, i2, notrunc),
1655 t = build_complex (type,
1657 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1658 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1659 const_binop (PLUS_EXPR,
1660 const_binop (MULT_EXPR, r1, r2,
1662 const_binop (MULT_EXPR, i1, i2,
1665 magsquared, notrunc),
1667 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1668 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1669 const_binop (MINUS_EXPR,
1670 const_binop (MULT_EXPR, i1, r2,
1672 const_binop (MULT_EXPR, r1, i2,
1675 magsquared, notrunc));
1687 /* Return an INTEGER_CST with value V . The type is determined by bit_p:
1688 if it is zero, the type is taken from sizetype; if it is one, the type
1689 is taken from bitsizetype. */
1692 size_int_wide (number, high, bit_p)
1693 unsigned HOST_WIDE_INT number, high;
1700 /* Type-size nodes already made for small sizes. */
1701 static tree size_table[2*HOST_BITS_PER_WIDE_INT + 1][2];
1703 if (number < 2*HOST_BITS_PER_WIDE_INT + 1 && ! high
1704 && size_table[number][bit_p] != 0)
1705 return size_table[number][bit_p];
1706 if (number < 2*HOST_BITS_PER_WIDE_INT + 1 && ! high)
1708 push_obstacks_nochange ();
1709 /* Make this a permanent node. */
1710 end_temporary_allocation ();
1711 t = build_int_2 (number, 0);
1712 TREE_TYPE (t) = bit_p ? bitsizetype : sizetype;
1713 size_table[number][bit_p] = t;
1719 t = build_int_2 (number, high);
1720 TREE_TYPE (t) = bit_p ? bitsizetype : sizetype;
1721 TREE_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (t) = force_fit_type (t, 0);
1725 /* Combine operands OP1 and OP2 with arithmetic operation CODE.
1726 CODE is a tree code. Data type is taken from `sizetype',
1727 If the operands are constant, so is the result. */
1730 size_binop (code, arg0, arg1)
1731 enum tree_code code;
1734 /* Handle the special case of two integer constants faster. */
1735 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1737 /* And some specific cases even faster than that. */
1738 if (code == PLUS_EXPR && integer_zerop (arg0))
1740 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1741 && integer_zerop (arg1))
1743 else if (code == MULT_EXPR && integer_onep (arg0))
1746 /* Handle general case of two integer constants. */
1747 return int_const_binop (code, arg0, arg1, 0, 1);
1750 if (arg0 == error_mark_node || arg1 == error_mark_node)
1751 return error_mark_node;
1753 return fold (build (code, sizetype, arg0, arg1));
1756 /* Combine operands OP1 and OP2 with arithmetic operation CODE.
1757 CODE is a tree code. Data type is taken from `ssizetype',
1758 If the operands are constant, so is the result. */
1761 ssize_binop (code, arg0, arg1)
1762 enum tree_code code;
1765 /* Handle the special case of two integer constants faster. */
1766 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1768 /* And some specific cases even faster than that. */
1769 if (code == PLUS_EXPR && integer_zerop (arg0))
1771 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1772 && integer_zerop (arg1))
1774 else if (code == MULT_EXPR && integer_onep (arg0))
1777 /* Handle general case of two integer constants. We convert
1778 arg0 to ssizetype because int_const_binop uses its type for the
1780 arg0 = convert (ssizetype, arg0);
1781 return int_const_binop (code, arg0, arg1, 0, 0);
1784 if (arg0 == error_mark_node || arg1 == error_mark_node)
1785 return error_mark_node;
1787 return fold (build (code, ssizetype, arg0, arg1));
1799 fold_convert_1 (data)
1802 struct fc_args * args = (struct fc_args *) data;
1804 args->t = build_real (args->type,
1805 real_value_truncate (TYPE_MODE (args->type),
1806 TREE_REAL_CST (args->arg1)));
1809 /* Given T, a tree representing type conversion of ARG1, a constant,
1810 return a constant tree representing the result of conversion. */
1813 fold_convert (t, arg1)
1817 register tree type = TREE_TYPE (t);
1820 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
1822 if (TREE_CODE (arg1) == INTEGER_CST)
1824 /* If we would build a constant wider than GCC supports,
1825 leave the conversion unfolded. */
1826 if (TYPE_PRECISION (type) > 2 * HOST_BITS_PER_WIDE_INT)
1829 /* Given an integer constant, make new constant with new type,
1830 appropriately sign-extended or truncated. */
1831 t = build_int_2 (TREE_INT_CST_LOW (arg1),
1832 TREE_INT_CST_HIGH (arg1));
1833 TREE_TYPE (t) = type;
1834 /* Indicate an overflow if (1) ARG1 already overflowed,
1835 or (2) force_fit_type indicates an overflow.
1836 Tell force_fit_type that an overflow has already occurred
1837 if ARG1 is a too-large unsigned value and T is signed.
1838 But don't indicate an overflow if converting a pointer. */
1840 = ((force_fit_type (t,
1841 (TREE_INT_CST_HIGH (arg1) < 0
1842 && (TREE_UNSIGNED (type)
1843 < TREE_UNSIGNED (TREE_TYPE (arg1)))))
1844 && ! POINTER_TYPE_P (TREE_TYPE (arg1)))
1845 || TREE_OVERFLOW (arg1));
1846 TREE_CONSTANT_OVERFLOW (t)
1847 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1849 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1850 else if (TREE_CODE (arg1) == REAL_CST)
1852 /* Don't initialize these, use assignments.
1853 Initialized local aggregates don't work on old compilers. */
1857 tree type1 = TREE_TYPE (arg1);
1860 x = TREE_REAL_CST (arg1);
1861 l = real_value_from_int_cst (type1, TYPE_MIN_VALUE (type));
1863 no_upper_bound = (TYPE_MAX_VALUE (type) == NULL);
1864 if (!no_upper_bound)
1865 u = real_value_from_int_cst (type1, TYPE_MAX_VALUE (type));
1867 /* See if X will be in range after truncation towards 0.
1868 To compensate for truncation, move the bounds away from 0,
1869 but reject if X exactly equals the adjusted bounds. */
1870 #ifdef REAL_ARITHMETIC
1871 REAL_ARITHMETIC (l, MINUS_EXPR, l, dconst1);
1872 if (!no_upper_bound)
1873 REAL_ARITHMETIC (u, PLUS_EXPR, u, dconst1);
1876 if (!no_upper_bound)
1879 /* If X is a NaN, use zero instead and show we have an overflow.
1880 Otherwise, range check. */
1881 if (REAL_VALUE_ISNAN (x))
1882 overflow = 1, x = dconst0;
1883 else if (! (REAL_VALUES_LESS (l, x)
1885 && REAL_VALUES_LESS (x, u)))
1888 #ifndef REAL_ARITHMETIC
1890 HOST_WIDE_INT low, high;
1891 HOST_WIDE_INT half_word
1892 = (HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2);
1897 high = (HOST_WIDE_INT) (x / half_word / half_word);
1898 x -= (REAL_VALUE_TYPE) high * half_word * half_word;
1899 if (x >= (REAL_VALUE_TYPE) half_word * half_word / 2)
1901 low = x - (REAL_VALUE_TYPE) half_word * half_word / 2;
1902 low |= (HOST_WIDE_INT) -1 << (HOST_BITS_PER_WIDE_INT - 1);
1905 low = (HOST_WIDE_INT) x;
1906 if (TREE_REAL_CST (arg1) < 0)
1907 neg_double (low, high, &low, &high);
1908 t = build_int_2 (low, high);
1912 HOST_WIDE_INT low, high;
1913 REAL_VALUE_TO_INT (&low, &high, x);
1914 t = build_int_2 (low, high);
1917 TREE_TYPE (t) = type;
1919 = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
1920 TREE_CONSTANT_OVERFLOW (t)
1921 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1923 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
1924 TREE_TYPE (t) = type;
1926 else if (TREE_CODE (type) == REAL_TYPE)
1928 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1929 if (TREE_CODE (arg1) == INTEGER_CST)
1930 return build_real_from_int_cst (type, arg1);
1931 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
1932 if (TREE_CODE (arg1) == REAL_CST)
1934 struct fc_args args;
1936 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
1939 TREE_TYPE (arg1) = type;
1943 /* Setup input for fold_convert_1() */
1947 if (do_float_handler (fold_convert_1, (PTR) &args))
1949 /* Receive output from fold_convert_1() */
1954 /* We got an exception from fold_convert_1() */
1956 t = copy_node (arg1);
1960 = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
1961 TREE_CONSTANT_OVERFLOW (t)
1962 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1966 TREE_CONSTANT (t) = 1;
1970 /* Return an expr equal to X but certainly not valid as an lvalue. */
1978 /* These things are certainly not lvalues. */
1979 if (TREE_CODE (x) == NON_LVALUE_EXPR
1980 || TREE_CODE (x) == INTEGER_CST
1981 || TREE_CODE (x) == REAL_CST
1982 || TREE_CODE (x) == STRING_CST
1983 || TREE_CODE (x) == ADDR_EXPR)
1986 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
1987 TREE_CONSTANT (result) = TREE_CONSTANT (x);
1991 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
1992 Zero means allow extended lvalues. */
1994 int pedantic_lvalues;
1996 /* When pedantic, return an expr equal to X but certainly not valid as a
1997 pedantic lvalue. Otherwise, return X. */
2000 pedantic_non_lvalue (x)
2003 if (pedantic_lvalues)
2004 return non_lvalue (x);
2009 /* Given a tree comparison code, return the code that is the logical inverse
2010 of the given code. It is not safe to do this for floating-point
2011 comparisons, except for NE_EXPR and EQ_EXPR. */
2013 static enum tree_code
2014 invert_tree_comparison (code)
2015 enum tree_code code;
2036 /* Similar, but return the comparison that results if the operands are
2037 swapped. This is safe for floating-point. */
2039 static enum tree_code
2040 swap_tree_comparison (code)
2041 enum tree_code code;
2061 /* Return nonzero if CODE is a tree code that represents a truth value. */
2064 truth_value_p (code)
2065 enum tree_code code;
2067 return (TREE_CODE_CLASS (code) == '<'
2068 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2069 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2070 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
2073 /* Return nonzero if two operands are necessarily equal.
2074 If ONLY_CONST is non-zero, only return non-zero for constants.
2075 This function tests whether the operands are indistinguishable;
2076 it does not test whether they are equal using C's == operation.
2077 The distinction is important for IEEE floating point, because
2078 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2079 (2) two NaNs may be indistinguishable, but NaN!=NaN. */
2082 operand_equal_p (arg0, arg1, only_const)
2086 /* If both types don't have the same signedness, then we can't consider
2087 them equal. We must check this before the STRIP_NOPS calls
2088 because they may change the signedness of the arguments. */
2089 if (TREE_UNSIGNED (TREE_TYPE (arg0)) != TREE_UNSIGNED (TREE_TYPE (arg1)))
2095 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2096 /* This is needed for conversions and for COMPONENT_REF.
2097 Might as well play it safe and always test this. */
2098 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
2099 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
2100 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
2103 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
2104 We don't care about side effects in that case because the SAVE_EXPR
2105 takes care of that for us. In all other cases, two expressions are
2106 equal if they have no side effects. If we have two identical
2107 expressions with side effects that should be treated the same due
2108 to the only side effects being identical SAVE_EXPR's, that will
2109 be detected in the recursive calls below. */
2110 if (arg0 == arg1 && ! only_const
2111 && (TREE_CODE (arg0) == SAVE_EXPR
2112 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
2115 /* Next handle constant cases, those for which we can return 1 even
2116 if ONLY_CONST is set. */
2117 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
2118 switch (TREE_CODE (arg0))
2121 return (! TREE_CONSTANT_OVERFLOW (arg0)
2122 && ! TREE_CONSTANT_OVERFLOW (arg1)
2123 && TREE_INT_CST_LOW (arg0) == TREE_INT_CST_LOW (arg1)
2124 && TREE_INT_CST_HIGH (arg0) == TREE_INT_CST_HIGH (arg1));
2127 return (! TREE_CONSTANT_OVERFLOW (arg0)
2128 && ! TREE_CONSTANT_OVERFLOW (arg1)
2129 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
2130 TREE_REAL_CST (arg1)));
2133 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
2135 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
2139 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
2140 && ! strncmp (TREE_STRING_POINTER (arg0),
2141 TREE_STRING_POINTER (arg1),
2142 TREE_STRING_LENGTH (arg0)));
2145 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
2154 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
2157 /* Two conversions are equal only if signedness and modes match. */
2158 if ((TREE_CODE (arg0) == NOP_EXPR || TREE_CODE (arg0) == CONVERT_EXPR)
2159 && (TREE_UNSIGNED (TREE_TYPE (arg0))
2160 != TREE_UNSIGNED (TREE_TYPE (arg1))))
2163 return operand_equal_p (TREE_OPERAND (arg0, 0),
2164 TREE_OPERAND (arg1, 0), 0);
2168 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0)
2169 && operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1),
2173 /* For commutative ops, allow the other order. */
2174 return ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MULT_EXPR
2175 || TREE_CODE (arg0) == MIN_EXPR || TREE_CODE (arg0) == MAX_EXPR
2176 || TREE_CODE (arg0) == BIT_IOR_EXPR
2177 || TREE_CODE (arg0) == BIT_XOR_EXPR
2178 || TREE_CODE (arg0) == BIT_AND_EXPR
2179 || TREE_CODE (arg0) == NE_EXPR || TREE_CODE (arg0) == EQ_EXPR)
2180 && operand_equal_p (TREE_OPERAND (arg0, 0),
2181 TREE_OPERAND (arg1, 1), 0)
2182 && operand_equal_p (TREE_OPERAND (arg0, 1),
2183 TREE_OPERAND (arg1, 0), 0));
2186 switch (TREE_CODE (arg0))
2189 return operand_equal_p (TREE_OPERAND (arg0, 0),
2190 TREE_OPERAND (arg1, 0), 0);
2194 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2195 TREE_OPERAND (arg1, 0), 0)
2196 && operand_equal_p (TREE_OPERAND (arg0, 1),
2197 TREE_OPERAND (arg1, 1), 0));
2200 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2201 TREE_OPERAND (arg1, 0), 0)
2202 && operand_equal_p (TREE_OPERAND (arg0, 1),
2203 TREE_OPERAND (arg1, 1), 0)
2204 && operand_equal_p (TREE_OPERAND (arg0, 2),
2205 TREE_OPERAND (arg1, 2), 0));
2211 if (TREE_CODE (arg0) == RTL_EXPR)
2212 return rtx_equal_p (RTL_EXPR_RTL (arg0), RTL_EXPR_RTL (arg1));
2220 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2221 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2223 When in doubt, return 0. */
2226 operand_equal_for_comparison_p (arg0, arg1, other)
2230 int unsignedp1, unsignedpo;
2231 tree primarg0, primarg1, primother;
2232 unsigned correct_width;
2234 if (operand_equal_p (arg0, arg1, 0))
2237 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
2238 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
2241 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2242 and see if the inner values are the same. This removes any
2243 signedness comparison, which doesn't matter here. */
2244 primarg0 = arg0, primarg1 = arg1;
2245 STRIP_NOPS (primarg0); STRIP_NOPS (primarg1);
2246 if (operand_equal_p (primarg0, primarg1, 0))
2249 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2250 actual comparison operand, ARG0.
2252 First throw away any conversions to wider types
2253 already present in the operands. */
2255 primarg1 = get_narrower (arg1, &unsignedp1);
2256 primother = get_narrower (other, &unsignedpo);
2258 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
2259 if (unsignedp1 == unsignedpo
2260 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
2261 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
2263 tree type = TREE_TYPE (arg0);
2265 /* Make sure shorter operand is extended the right way
2266 to match the longer operand. */
2267 primarg1 = convert (signed_or_unsigned_type (unsignedp1,
2268 TREE_TYPE (primarg1)),
2271 if (operand_equal_p (arg0, convert (type, primarg1), 0))
2278 /* See if ARG is an expression that is either a comparison or is performing
2279 arithmetic on comparisons. The comparisons must only be comparing
2280 two different values, which will be stored in *CVAL1 and *CVAL2; if
2281 they are non-zero it means that some operands have already been found.
2282 No variables may be used anywhere else in the expression except in the
2283 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2284 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2286 If this is true, return 1. Otherwise, return zero. */
2289 twoval_comparison_p (arg, cval1, cval2, save_p)
2291 tree *cval1, *cval2;
2294 enum tree_code code = TREE_CODE (arg);
2295 char class = TREE_CODE_CLASS (code);
2297 /* We can handle some of the 'e' cases here. */
2298 if (class == 'e' && code == TRUTH_NOT_EXPR)
2300 else if (class == 'e'
2301 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
2302 || code == COMPOUND_EXPR))
2305 /* ??? Disable this since the SAVE_EXPR might already be in use outside
2306 the expression. There may be no way to make this work, but it needs
2307 to be looked at again for 2.6. */
2309 else if (class == 'e' && code == SAVE_EXPR && SAVE_EXPR_RTL (arg) == 0)
2311 /* If we've already found a CVAL1 or CVAL2, this expression is
2312 two complex to handle. */
2313 if (*cval1 || *cval2)
2324 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
2327 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
2328 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2329 cval1, cval2, save_p));
2335 if (code == COND_EXPR)
2336 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
2337 cval1, cval2, save_p)
2338 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2339 cval1, cval2, save_p)
2340 && twoval_comparison_p (TREE_OPERAND (arg, 2),
2341 cval1, cval2, save_p));
2345 /* First see if we can handle the first operand, then the second. For
2346 the second operand, we know *CVAL1 can't be zero. It must be that
2347 one side of the comparison is each of the values; test for the
2348 case where this isn't true by failing if the two operands
2351 if (operand_equal_p (TREE_OPERAND (arg, 0),
2352 TREE_OPERAND (arg, 1), 0))
2356 *cval1 = TREE_OPERAND (arg, 0);
2357 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
2359 else if (*cval2 == 0)
2360 *cval2 = TREE_OPERAND (arg, 0);
2361 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
2366 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
2368 else if (*cval2 == 0)
2369 *cval2 = TREE_OPERAND (arg, 1);
2370 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
2382 /* ARG is a tree that is known to contain just arithmetic operations and
2383 comparisons. Evaluate the operations in the tree substituting NEW0 for
2384 any occurrence of OLD0 as an operand of a comparison and likewise for
2388 eval_subst (arg, old0, new0, old1, new1)
2390 tree old0, new0, old1, new1;
2392 tree type = TREE_TYPE (arg);
2393 enum tree_code code = TREE_CODE (arg);
2394 char class = TREE_CODE_CLASS (code);
2396 /* We can handle some of the 'e' cases here. */
2397 if (class == 'e' && code == TRUTH_NOT_EXPR)
2399 else if (class == 'e'
2400 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2406 return fold (build1 (code, type,
2407 eval_subst (TREE_OPERAND (arg, 0),
2408 old0, new0, old1, new1)));
2411 return fold (build (code, type,
2412 eval_subst (TREE_OPERAND (arg, 0),
2413 old0, new0, old1, new1),
2414 eval_subst (TREE_OPERAND (arg, 1),
2415 old0, new0, old1, new1)));
2421 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
2424 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
2427 return fold (build (code, type,
2428 eval_subst (TREE_OPERAND (arg, 0),
2429 old0, new0, old1, new1),
2430 eval_subst (TREE_OPERAND (arg, 1),
2431 old0, new0, old1, new1),
2432 eval_subst (TREE_OPERAND (arg, 2),
2433 old0, new0, old1, new1)));
2437 /* fall through - ??? */
2441 tree arg0 = TREE_OPERAND (arg, 0);
2442 tree arg1 = TREE_OPERAND (arg, 1);
2444 /* We need to check both for exact equality and tree equality. The
2445 former will be true if the operand has a side-effect. In that
2446 case, we know the operand occurred exactly once. */
2448 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
2450 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
2453 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
2455 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
2458 return fold (build (code, type, arg0, arg1));
2466 /* Return a tree for the case when the result of an expression is RESULT
2467 converted to TYPE and OMITTED was previously an operand of the expression
2468 but is now not needed (e.g., we folded OMITTED * 0).
2470 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2471 the conversion of RESULT to TYPE. */
2474 omit_one_operand (type, result, omitted)
2475 tree type, result, omitted;
2477 tree t = convert (type, result);
2479 if (TREE_SIDE_EFFECTS (omitted))
2480 return build (COMPOUND_EXPR, type, omitted, t);
2482 return non_lvalue (t);
2485 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2488 pedantic_omit_one_operand (type, result, omitted)
2489 tree type, result, omitted;
2491 tree t = convert (type, result);
2493 if (TREE_SIDE_EFFECTS (omitted))
2494 return build (COMPOUND_EXPR, type, omitted, t);
2496 return pedantic_non_lvalue (t);
2501 /* Return a simplified tree node for the truth-negation of ARG. This
2502 never alters ARG itself. We assume that ARG is an operation that
2503 returns a truth value (0 or 1). */
2506 invert_truthvalue (arg)
2509 tree type = TREE_TYPE (arg);
2510 enum tree_code code = TREE_CODE (arg);
2512 if (code == ERROR_MARK)
2515 /* If this is a comparison, we can simply invert it, except for
2516 floating-point non-equality comparisons, in which case we just
2517 enclose a TRUTH_NOT_EXPR around what we have. */
2519 if (TREE_CODE_CLASS (code) == '<')
2521 if (FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg, 0)))
2522 && !flag_fast_math && code != NE_EXPR && code != EQ_EXPR)
2523 return build1 (TRUTH_NOT_EXPR, type, arg);
2525 return build (invert_tree_comparison (code), type,
2526 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
2532 return convert (type, build_int_2 (TREE_INT_CST_LOW (arg) == 0
2533 && TREE_INT_CST_HIGH (arg) == 0, 0));
2535 case TRUTH_AND_EXPR:
2536 return build (TRUTH_OR_EXPR, type,
2537 invert_truthvalue (TREE_OPERAND (arg, 0)),
2538 invert_truthvalue (TREE_OPERAND (arg, 1)));
2541 return build (TRUTH_AND_EXPR, type,
2542 invert_truthvalue (TREE_OPERAND (arg, 0)),
2543 invert_truthvalue (TREE_OPERAND (arg, 1)));
2545 case TRUTH_XOR_EXPR:
2546 /* Here we can invert either operand. We invert the first operand
2547 unless the second operand is a TRUTH_NOT_EXPR in which case our
2548 result is the XOR of the first operand with the inside of the
2549 negation of the second operand. */
2551 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
2552 return build (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
2553 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
2555 return build (TRUTH_XOR_EXPR, type,
2556 invert_truthvalue (TREE_OPERAND (arg, 0)),
2557 TREE_OPERAND (arg, 1));
2559 case TRUTH_ANDIF_EXPR:
2560 return build (TRUTH_ORIF_EXPR, type,
2561 invert_truthvalue (TREE_OPERAND (arg, 0)),
2562 invert_truthvalue (TREE_OPERAND (arg, 1)));
2564 case TRUTH_ORIF_EXPR:
2565 return build (TRUTH_ANDIF_EXPR, type,
2566 invert_truthvalue (TREE_OPERAND (arg, 0)),
2567 invert_truthvalue (TREE_OPERAND (arg, 1)));
2569 case TRUTH_NOT_EXPR:
2570 return TREE_OPERAND (arg, 0);
2573 return build (COND_EXPR, type, TREE_OPERAND (arg, 0),
2574 invert_truthvalue (TREE_OPERAND (arg, 1)),
2575 invert_truthvalue (TREE_OPERAND (arg, 2)));
2578 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
2579 invert_truthvalue (TREE_OPERAND (arg, 1)));
2581 case NON_LVALUE_EXPR:
2582 return invert_truthvalue (TREE_OPERAND (arg, 0));
2587 return build1 (TREE_CODE (arg), type,
2588 invert_truthvalue (TREE_OPERAND (arg, 0)));
2591 if (!integer_onep (TREE_OPERAND (arg, 1)))
2593 return build (EQ_EXPR, type, arg, convert (type, integer_zero_node));
2596 return build1 (TRUTH_NOT_EXPR, type, arg);
2598 case CLEANUP_POINT_EXPR:
2599 return build1 (CLEANUP_POINT_EXPR, type,
2600 invert_truthvalue (TREE_OPERAND (arg, 0)));
2605 if (TREE_CODE (TREE_TYPE (arg)) != BOOLEAN_TYPE)
2607 return build1 (TRUTH_NOT_EXPR, type, arg);
2610 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
2611 operands are another bit-wise operation with a common input. If so,
2612 distribute the bit operations to save an operation and possibly two if
2613 constants are involved. For example, convert
2614 (A | B) & (A | C) into A | (B & C)
2615 Further simplification will occur if B and C are constants.
2617 If this optimization cannot be done, 0 will be returned. */
2620 distribute_bit_expr (code, type, arg0, arg1)
2621 enum tree_code code;
2628 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2629 || TREE_CODE (arg0) == code
2630 || (TREE_CODE (arg0) != BIT_AND_EXPR
2631 && TREE_CODE (arg0) != BIT_IOR_EXPR))
2634 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
2636 common = TREE_OPERAND (arg0, 0);
2637 left = TREE_OPERAND (arg0, 1);
2638 right = TREE_OPERAND (arg1, 1);
2640 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
2642 common = TREE_OPERAND (arg0, 0);
2643 left = TREE_OPERAND (arg0, 1);
2644 right = TREE_OPERAND (arg1, 0);
2646 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
2648 common = TREE_OPERAND (arg0, 1);
2649 left = TREE_OPERAND (arg0, 0);
2650 right = TREE_OPERAND (arg1, 1);
2652 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
2654 common = TREE_OPERAND (arg0, 1);
2655 left = TREE_OPERAND (arg0, 0);
2656 right = TREE_OPERAND (arg1, 0);
2661 return fold (build (TREE_CODE (arg0), type, common,
2662 fold (build (code, type, left, right))));
2665 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
2666 starting at BITPOS. The field is unsigned if UNSIGNEDP is non-zero. */
2669 make_bit_field_ref (inner, type, bitsize, bitpos, unsignedp)
2672 int bitsize, bitpos;
2675 tree result = build (BIT_FIELD_REF, type, inner,
2676 size_int (bitsize), bitsize_int (bitpos, 0L));
2678 TREE_UNSIGNED (result) = unsignedp;
2683 /* Optimize a bit-field compare.
2685 There are two cases: First is a compare against a constant and the
2686 second is a comparison of two items where the fields are at the same
2687 bit position relative to the start of a chunk (byte, halfword, word)
2688 large enough to contain it. In these cases we can avoid the shift
2689 implicit in bitfield extractions.
2691 For constants, we emit a compare of the shifted constant with the
2692 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
2693 compared. For two fields at the same position, we do the ANDs with the
2694 similar mask and compare the result of the ANDs.
2696 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
2697 COMPARE_TYPE is the type of the comparison, and LHS and RHS
2698 are the left and right operands of the comparison, respectively.
2700 If the optimization described above can be done, we return the resulting
2701 tree. Otherwise we return zero. */
2704 optimize_bit_field_compare (code, compare_type, lhs, rhs)
2705 enum tree_code code;
2709 int lbitpos, lbitsize, rbitpos, rbitsize;
2710 int lnbitpos, lnbitsize, rnbitpos = 0, rnbitsize = 0;
2711 tree type = TREE_TYPE (lhs);
2712 tree signed_type, unsigned_type;
2713 int const_p = TREE_CODE (rhs) == INTEGER_CST;
2714 enum machine_mode lmode, rmode, lnmode, rnmode = VOIDmode;
2715 int lunsignedp, runsignedp;
2716 int lvolatilep = 0, rvolatilep = 0;
2718 tree linner, rinner = NULL_TREE;
2722 /* Get all the information about the extractions being done. If the bit size
2723 if the same as the size of the underlying object, we aren't doing an
2724 extraction at all and so can do nothing. */
2725 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
2726 &lunsignedp, &lvolatilep, &alignment);
2727 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
2733 /* If this is not a constant, we can only do something if bit positions,
2734 sizes, and signedness are the same. */
2735 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
2736 &runsignedp, &rvolatilep, &alignment);
2738 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
2739 || lunsignedp != runsignedp || offset != 0)
2743 /* See if we can find a mode to refer to this field. We should be able to,
2744 but fail if we can't. */
2745 lnmode = get_best_mode (lbitsize, lbitpos,
2746 TYPE_ALIGN (TREE_TYPE (linner)), word_mode,
2748 if (lnmode == VOIDmode)
2751 /* Set signed and unsigned types of the precision of this mode for the
2753 signed_type = type_for_mode (lnmode, 0);
2754 unsigned_type = type_for_mode (lnmode, 1);
2758 rnmode = get_best_mode (rbitsize, rbitpos,
2759 TYPE_ALIGN (TREE_TYPE (rinner)), word_mode,
2761 if (rnmode == VOIDmode)
2765 /* Compute the bit position and size for the new reference and our offset
2766 within it. If the new reference is the same size as the original, we
2767 won't optimize anything, so return zero. */
2768 lnbitsize = GET_MODE_BITSIZE (lnmode);
2769 lnbitpos = lbitpos & ~ (lnbitsize - 1);
2770 lbitpos -= lnbitpos;
2771 if (lnbitsize == lbitsize)
2776 rnbitsize = GET_MODE_BITSIZE (rnmode);
2777 rnbitpos = rbitpos & ~ (rnbitsize - 1);
2778 rbitpos -= rnbitpos;
2779 if (rnbitsize == rbitsize)
2783 if (BYTES_BIG_ENDIAN)
2784 lbitpos = lnbitsize - lbitsize - lbitpos;
2786 /* Make the mask to be used against the extracted field. */
2787 mask = build_int_2 (~0, ~0);
2788 TREE_TYPE (mask) = unsigned_type;
2789 force_fit_type (mask, 0);
2790 mask = convert (unsigned_type, mask);
2791 mask = const_binop (LSHIFT_EXPR, mask, size_int (lnbitsize - lbitsize), 0);
2792 mask = const_binop (RSHIFT_EXPR, mask,
2793 size_int (lnbitsize - lbitsize - lbitpos), 0);
2796 /* If not comparing with constant, just rework the comparison
2798 return build (code, compare_type,
2799 build (BIT_AND_EXPR, unsigned_type,
2800 make_bit_field_ref (linner, unsigned_type,
2801 lnbitsize, lnbitpos, 1),
2803 build (BIT_AND_EXPR, unsigned_type,
2804 make_bit_field_ref (rinner, unsigned_type,
2805 rnbitsize, rnbitpos, 1),
2808 /* Otherwise, we are handling the constant case. See if the constant is too
2809 big for the field. Warn and return a tree of for 0 (false) if so. We do
2810 this not only for its own sake, but to avoid having to test for this
2811 error case below. If we didn't, we might generate wrong code.
2813 For unsigned fields, the constant shifted right by the field length should
2814 be all zero. For signed fields, the high-order bits should agree with
2819 if (! integer_zerop (const_binop (RSHIFT_EXPR,
2820 convert (unsigned_type, rhs),
2821 size_int (lbitsize), 0)))
2823 warning ("comparison is always %d due to width of bitfield",
2825 return convert (compare_type,
2827 ? integer_one_node : integer_zero_node));
2832 tree tem = const_binop (RSHIFT_EXPR, convert (signed_type, rhs),
2833 size_int (lbitsize - 1), 0);
2834 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
2836 warning ("comparison is always %d due to width of bitfield",
2838 return convert (compare_type,
2840 ? integer_one_node : integer_zero_node));
2844 /* Single-bit compares should always be against zero. */
2845 if (lbitsize == 1 && ! integer_zerop (rhs))
2847 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
2848 rhs = convert (type, integer_zero_node);
2851 /* Make a new bitfield reference, shift the constant over the
2852 appropriate number of bits and mask it with the computed mask
2853 (in case this was a signed field). If we changed it, make a new one. */
2854 lhs = make_bit_field_ref (linner, unsigned_type, lnbitsize, lnbitpos, 1);
2857 TREE_SIDE_EFFECTS (lhs) = 1;
2858 TREE_THIS_VOLATILE (lhs) = 1;
2861 rhs = fold (const_binop (BIT_AND_EXPR,
2862 const_binop (LSHIFT_EXPR,
2863 convert (unsigned_type, rhs),
2864 size_int (lbitpos), 0),
2867 return build (code, compare_type,
2868 build (BIT_AND_EXPR, unsigned_type, lhs, mask),
2872 /* Subroutine for fold_truthop: decode a field reference.
2874 If EXP is a comparison reference, we return the innermost reference.
2876 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
2877 set to the starting bit number.
2879 If the innermost field can be completely contained in a mode-sized
2880 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
2882 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
2883 otherwise it is not changed.
2885 *PUNSIGNEDP is set to the signedness of the field.
2887 *PMASK is set to the mask used. This is either contained in a
2888 BIT_AND_EXPR or derived from the width of the field.
2890 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
2892 Return 0 if this is not a component reference or is one that we can't
2893 do anything with. */
2896 decode_field_reference (exp, pbitsize, pbitpos, pmode, punsignedp,
2897 pvolatilep, pmask, pand_mask)
2899 int *pbitsize, *pbitpos;
2900 enum machine_mode *pmode;
2901 int *punsignedp, *pvolatilep;
2906 tree mask, inner, offset;
2911 /* All the optimizations using this function assume integer fields.
2912 There are problems with FP fields since the type_for_size call
2913 below can fail for, e.g., XFmode. */
2914 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
2919 if (TREE_CODE (exp) == BIT_AND_EXPR)
2921 and_mask = TREE_OPERAND (exp, 1);
2922 exp = TREE_OPERAND (exp, 0);
2923 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
2924 if (TREE_CODE (and_mask) != INTEGER_CST)
2929 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
2930 punsignedp, pvolatilep, &alignment);
2931 if ((inner == exp && and_mask == 0)
2932 || *pbitsize < 0 || offset != 0)
2935 /* Compute the mask to access the bitfield. */
2936 unsigned_type = type_for_size (*pbitsize, 1);
2937 precision = TYPE_PRECISION (unsigned_type);
2939 mask = build_int_2 (~0, ~0);
2940 TREE_TYPE (mask) = unsigned_type;
2941 force_fit_type (mask, 0);
2942 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
2943 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
2945 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
2947 mask = fold (build (BIT_AND_EXPR, unsigned_type,
2948 convert (unsigned_type, and_mask), mask));
2951 *pand_mask = and_mask;
2955 /* Return non-zero if MASK represents a mask of SIZE ones in the low-order
2959 all_ones_mask_p (mask, size)
2963 tree type = TREE_TYPE (mask);
2964 int precision = TYPE_PRECISION (type);
2967 tmask = build_int_2 (~0, ~0);
2968 TREE_TYPE (tmask) = signed_type (type);
2969 force_fit_type (tmask, 0);
2971 tree_int_cst_equal (mask,
2972 const_binop (RSHIFT_EXPR,
2973 const_binop (LSHIFT_EXPR, tmask,
2974 size_int (precision - size),
2976 size_int (precision - size), 0));
2979 /* Subroutine for fold_truthop: determine if an operand is simple enough
2980 to be evaluated unconditionally. */
2983 simple_operand_p (exp)
2986 /* Strip any conversions that don't change the machine mode. */
2987 while ((TREE_CODE (exp) == NOP_EXPR
2988 || TREE_CODE (exp) == CONVERT_EXPR)
2989 && (TYPE_MODE (TREE_TYPE (exp))
2990 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)))))
2991 exp = TREE_OPERAND (exp, 0);
2993 return (TREE_CODE_CLASS (TREE_CODE (exp)) == 'c'
2994 || (TREE_CODE_CLASS (TREE_CODE (exp)) == 'd'
2995 && ! TREE_ADDRESSABLE (exp)
2996 && ! TREE_THIS_VOLATILE (exp)
2997 && ! DECL_NONLOCAL (exp)
2998 /* Don't regard global variables as simple. They may be
2999 allocated in ways unknown to the compiler (shared memory,
3000 #pragma weak, etc). */
3001 && ! TREE_PUBLIC (exp)
3002 && ! DECL_EXTERNAL (exp)
3003 /* Loading a static variable is unduly expensive, but global
3004 registers aren't expensive. */
3005 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
3008 /* The following functions are subroutines to fold_range_test and allow it to
3009 try to change a logical combination of comparisons into a range test.
3012 X == 2 && X == 3 && X == 4 && X == 5
3016 (unsigned) (X - 2) <= 3
3018 We describe each set of comparisons as being either inside or outside
3019 a range, using a variable named like IN_P, and then describe the
3020 range with a lower and upper bound. If one of the bounds is omitted,
3021 it represents either the highest or lowest value of the type.
3023 In the comments below, we represent a range by two numbers in brackets
3024 preceded by a "+" to designate being inside that range, or a "-" to
3025 designate being outside that range, so the condition can be inverted by
3026 flipping the prefix. An omitted bound is represented by a "-". For
3027 example, "- [-, 10]" means being outside the range starting at the lowest
3028 possible value and ending at 10, in other words, being greater than 10.
3029 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
3032 We set up things so that the missing bounds are handled in a consistent
3033 manner so neither a missing bound nor "true" and "false" need to be
3034 handled using a special case. */
3036 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
3037 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
3038 and UPPER1_P are nonzero if the respective argument is an upper bound
3039 and zero for a lower. TYPE, if nonzero, is the type of the result; it
3040 must be specified for a comparison. ARG1 will be converted to ARG0's
3041 type if both are specified. */
3044 range_binop (code, type, arg0, upper0_p, arg1, upper1_p)
3045 enum tree_code code;
3048 int upper0_p, upper1_p;
3054 /* If neither arg represents infinity, do the normal operation.
3055 Else, if not a comparison, return infinity. Else handle the special
3056 comparison rules. Note that most of the cases below won't occur, but
3057 are handled for consistency. */
3059 if (arg0 != 0 && arg1 != 0)
3061 tem = fold (build (code, type != 0 ? type : TREE_TYPE (arg0),
3062 arg0, convert (TREE_TYPE (arg0), arg1)));
3064 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
3067 if (TREE_CODE_CLASS (code) != '<')
3070 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
3071 for neither. In real maths, we cannot assume open ended ranges are
3072 the same. But, this is computer arithmetic, where numbers are finite.
3073 We can therefore make the transformation of any unbounded range with
3074 the value Z, Z being greater than any representable number. This permits
3075 us to treat unbounded ranges as equal. */
3076 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
3077 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
3081 result = sgn0 == sgn1;
3084 result = sgn0 != sgn1;
3087 result = sgn0 < sgn1;
3090 result = sgn0 <= sgn1;
3093 result = sgn0 > sgn1;
3096 result = sgn0 >= sgn1;
3102 return convert (type, result ? integer_one_node : integer_zero_node);
3105 /* Given EXP, a logical expression, set the range it is testing into
3106 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
3107 actually being tested. *PLOW and *PHIGH will have be made the same type
3108 as the returned expression. If EXP is not a comparison, we will most
3109 likely not be returning a useful value and range. */
3112 make_range (exp, pin_p, plow, phigh)
3117 enum tree_code code;
3118 tree arg0 = NULL_TREE, arg1 = NULL_TREE, type = NULL_TREE;
3119 tree orig_type = NULL_TREE;
3121 tree low, high, n_low, n_high;
3123 /* Start with simply saying "EXP != 0" and then look at the code of EXP
3124 and see if we can refine the range. Some of the cases below may not
3125 happen, but it doesn't seem worth worrying about this. We "continue"
3126 the outer loop when we've changed something; otherwise we "break"
3127 the switch, which will "break" the while. */
3129 in_p = 0, low = high = convert (TREE_TYPE (exp), integer_zero_node);
3133 code = TREE_CODE (exp);
3135 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
3137 arg0 = TREE_OPERAND (exp, 0);
3138 if (TREE_CODE_CLASS (code) == '<'
3139 || TREE_CODE_CLASS (code) == '1'
3140 || TREE_CODE_CLASS (code) == '2')
3141 type = TREE_TYPE (arg0);
3142 if (TREE_CODE_CLASS (code) == '2'
3143 || TREE_CODE_CLASS (code) == '<'
3144 || (TREE_CODE_CLASS (code) == 'e'
3145 && tree_code_length[(int) code] > 1))
3146 arg1 = TREE_OPERAND (exp, 1);
3149 /* Set ORIG_TYPE as soon as TYPE is non-null so that we do not
3150 lose a cast by accident. */
3151 if (type != NULL_TREE && orig_type == NULL_TREE)
3156 case TRUTH_NOT_EXPR:
3157 in_p = ! in_p, exp = arg0;
3160 case EQ_EXPR: case NE_EXPR:
3161 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
3162 /* We can only do something if the range is testing for zero
3163 and if the second operand is an integer constant. Note that
3164 saying something is "in" the range we make is done by
3165 complementing IN_P since it will set in the initial case of
3166 being not equal to zero; "out" is leaving it alone. */
3167 if (low == 0 || high == 0
3168 || ! integer_zerop (low) || ! integer_zerop (high)
3169 || TREE_CODE (arg1) != INTEGER_CST)
3174 case NE_EXPR: /* - [c, c] */
3177 case EQ_EXPR: /* + [c, c] */
3178 in_p = ! in_p, low = high = arg1;
3180 case GT_EXPR: /* - [-, c] */
3181 low = 0, high = arg1;
3183 case GE_EXPR: /* + [c, -] */
3184 in_p = ! in_p, low = arg1, high = 0;
3186 case LT_EXPR: /* - [c, -] */
3187 low = arg1, high = 0;
3189 case LE_EXPR: /* + [-, c] */
3190 in_p = ! in_p, low = 0, high = arg1;
3198 /* If this is an unsigned comparison, we also know that EXP is
3199 greater than or equal to zero. We base the range tests we make
3200 on that fact, so we record it here so we can parse existing
3202 if (TREE_UNSIGNED (type) && (low == 0 || high == 0))
3204 if (! merge_ranges (&n_in_p, &n_low, &n_high, in_p, low, high,
3205 1, convert (type, integer_zero_node),
3209 in_p = n_in_p, low = n_low, high = n_high;
3211 /* If the high bound is missing, reverse the range so it
3212 goes from zero to the low bound minus 1. */
3216 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
3217 integer_one_node, 0);
3218 low = convert (type, integer_zero_node);
3224 /* (-x) IN [a,b] -> x in [-b, -a] */
3225 n_low = range_binop (MINUS_EXPR, type,
3226 convert (type, integer_zero_node), 0, high, 1);
3227 n_high = range_binop (MINUS_EXPR, type,
3228 convert (type, integer_zero_node), 0, low, 0);
3229 low = n_low, high = n_high;
3235 exp = build (MINUS_EXPR, type, build1 (NEGATE_EXPR, type, arg0),
3236 convert (type, integer_one_node));
3239 case PLUS_EXPR: case MINUS_EXPR:
3240 if (TREE_CODE (arg1) != INTEGER_CST)
3243 /* If EXP is signed, any overflow in the computation is undefined,
3244 so we don't worry about it so long as our computations on
3245 the bounds don't overflow. For unsigned, overflow is defined
3246 and this is exactly the right thing. */
3247 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3248 type, low, 0, arg1, 0);
3249 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3250 type, high, 1, arg1, 0);
3251 if ((n_low != 0 && TREE_OVERFLOW (n_low))
3252 || (n_high != 0 && TREE_OVERFLOW (n_high)))
3255 /* Check for an unsigned range which has wrapped around the maximum
3256 value thus making n_high < n_low, and normalize it. */
3257 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
3259 low = range_binop (PLUS_EXPR, type, n_high, 0,
3260 integer_one_node, 0);
3261 high = range_binop (MINUS_EXPR, type, n_low, 0,
3262 integer_one_node, 0);
3266 low = n_low, high = n_high;
3271 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
3272 if (TYPE_PRECISION (type) > TYPE_PRECISION (orig_type))
3275 if (! INTEGRAL_TYPE_P (type)
3276 || (low != 0 && ! int_fits_type_p (low, type))
3277 || (high != 0 && ! int_fits_type_p (high, type)))
3280 n_low = low, n_high = high;
3283 n_low = convert (type, n_low);
3286 n_high = convert (type, n_high);
3288 /* If we're converting from an unsigned to a signed type,
3289 we will be doing the comparison as unsigned. The tests above
3290 have already verified that LOW and HIGH are both positive.
3292 So we have to make sure that the original unsigned value will
3293 be interpreted as positive. */
3294 if (TREE_UNSIGNED (type) && ! TREE_UNSIGNED (TREE_TYPE (exp)))
3296 tree equiv_type = type_for_mode (TYPE_MODE (type), 1);
3299 /* A range without an upper bound is, naturally, unbounded.
3300 Since convert would have cropped a very large value, use
3301 the max value for the destination type. */
3303 high_positive = TYPE_MAX_VALUE (equiv_type);
3306 high_positive = TYPE_MAX_VALUE (type);
3310 high_positive = fold (build (RSHIFT_EXPR, type,
3311 convert (type, high_positive),
3312 convert (type, integer_one_node)));
3314 /* If the low bound is specified, "and" the range with the
3315 range for which the original unsigned value will be
3319 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3321 1, convert (type, integer_zero_node),
3325 in_p = (n_in_p == in_p);
3329 /* Otherwise, "or" the range with the range of the input
3330 that will be interpreted as negative. */
3331 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3333 1, convert (type, integer_zero_node),
3337 in_p = (in_p != n_in_p);
3342 low = n_low, high = n_high;
3352 /* If EXP is a constant, we can evaluate whether this is true or false. */
3353 if (TREE_CODE (exp) == INTEGER_CST)
3355 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
3357 && integer_onep (range_binop (LE_EXPR, integer_type_node,
3363 *pin_p = in_p, *plow = low, *phigh = high;
3367 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3368 type, TYPE, return an expression to test if EXP is in (or out of, depending
3369 on IN_P) the range. */
3372 build_range_check (type, exp, in_p, low, high)
3378 tree etype = TREE_TYPE (exp);
3382 && (0 != (value = build_range_check (type, exp, 1, low, high))))
3383 return invert_truthvalue (value);
3385 else if (low == 0 && high == 0)
3386 return convert (type, integer_one_node);
3389 return fold (build (LE_EXPR, type, exp, high));
3392 return fold (build (GE_EXPR, type, exp, low));
3394 else if (operand_equal_p (low, high, 0))
3395 return fold (build (EQ_EXPR, type, exp, low));
3397 else if (TREE_UNSIGNED (etype) && integer_zerop (low))
3398 return build_range_check (type, exp, 1, 0, high);
3400 else if (integer_zerop (low))
3402 utype = unsigned_type (etype);
3403 return build_range_check (type, convert (utype, exp), 1, 0,
3404 convert (utype, high));
3407 else if (0 != (value = const_binop (MINUS_EXPR, high, low, 0))
3408 && ! TREE_OVERFLOW (value))
3409 return build_range_check (type,
3410 fold (build (MINUS_EXPR, etype, exp, low)),
3411 1, convert (etype, integer_zero_node), value);
3416 /* Given two ranges, see if we can merge them into one. Return 1 if we
3417 can, 0 if we can't. Set the output range into the specified parameters. */
3420 merge_ranges (pin_p, plow, phigh, in0_p, low0, high0, in1_p, low1, high1)
3424 tree low0, high0, low1, high1;
3432 int lowequal = ((low0 == 0 && low1 == 0)
3433 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3434 low0, 0, low1, 0)));
3435 int highequal = ((high0 == 0 && high1 == 0)
3436 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3437 high0, 1, high1, 1)));
3439 /* Make range 0 be the range that starts first, or ends last if they
3440 start at the same value. Swap them if it isn't. */
3441 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
3444 && integer_onep (range_binop (GT_EXPR, integer_type_node,
3445 high1, 1, high0, 1))))
3447 temp = in0_p, in0_p = in1_p, in1_p = temp;
3448 tem = low0, low0 = low1, low1 = tem;
3449 tem = high0, high0 = high1, high1 = tem;
3452 /* Now flag two cases, whether the ranges are disjoint or whether the
3453 second range is totally subsumed in the first. Note that the tests
3454 below are simplified by the ones above. */
3455 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
3456 high0, 1, low1, 0));
3457 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
3458 high1, 1, high0, 1));
3460 /* We now have four cases, depending on whether we are including or
3461 excluding the two ranges. */
3464 /* If they don't overlap, the result is false. If the second range
3465 is a subset it is the result. Otherwise, the range is from the start
3466 of the second to the end of the first. */
3468 in_p = 0, low = high = 0;
3470 in_p = 1, low = low1, high = high1;
3472 in_p = 1, low = low1, high = high0;
3475 else if (in0_p && ! in1_p)
3477 /* If they don't overlap, the result is the first range. If they are
3478 equal, the result is false. If the second range is a subset of the
3479 first, and the ranges begin at the same place, we go from just after
3480 the end of the first range to the end of the second. If the second
3481 range is not a subset of the first, or if it is a subset and both
3482 ranges end at the same place, the range starts at the start of the
3483 first range and ends just before the second range.
3484 Otherwise, we can't describe this as a single range. */
3486 in_p = 1, low = low0, high = high0;
3487 else if (lowequal && highequal)
3488 in_p = 0, low = high = 0;
3489 else if (subset && lowequal)
3491 in_p = 1, high = high0;
3492 low = range_binop (PLUS_EXPR, NULL_TREE, high1, 0,
3493 integer_one_node, 0);
3495 else if (! subset || highequal)
3497 in_p = 1, low = low0;
3498 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
3499 integer_one_node, 0);
3505 else if (! in0_p && in1_p)
3507 /* If they don't overlap, the result is the second range. If the second
3508 is a subset of the first, the result is false. Otherwise,
3509 the range starts just after the first range and ends at the
3510 end of the second. */
3512 in_p = 1, low = low1, high = high1;
3514 in_p = 0, low = high = 0;
3517 in_p = 1, high = high1;
3518 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
3519 integer_one_node, 0);
3525 /* The case where we are excluding both ranges. Here the complex case
3526 is if they don't overlap. In that case, the only time we have a
3527 range is if they are adjacent. If the second is a subset of the
3528 first, the result is the first. Otherwise, the range to exclude
3529 starts at the beginning of the first range and ends at the end of the
3533 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
3534 range_binop (PLUS_EXPR, NULL_TREE,
3536 integer_one_node, 1),
3538 in_p = 0, low = low0, high = high1;
3543 in_p = 0, low = low0, high = high0;
3545 in_p = 0, low = low0, high = high1;
3548 *pin_p = in_p, *plow = low, *phigh = high;
3552 /* EXP is some logical combination of boolean tests. See if we can
3553 merge it into some range test. Return the new tree if so. */
3556 fold_range_test (exp)
3559 int or_op = (TREE_CODE (exp) == TRUTH_ORIF_EXPR
3560 || TREE_CODE (exp) == TRUTH_OR_EXPR);
3561 int in0_p, in1_p, in_p;
3562 tree low0, low1, low, high0, high1, high;
3563 tree lhs = make_range (TREE_OPERAND (exp, 0), &in0_p, &low0, &high0);
3564 tree rhs = make_range (TREE_OPERAND (exp, 1), &in1_p, &low1, &high1);
3567 /* Fail if anything is volatile. */
3568 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
3571 /* If this is an OR operation, invert both sides; we will invert
3572 again at the end. */
3574 in0_p = ! in0_p, in1_p = ! in1_p;
3576 /* If both expressions are the same, if we can merge the ranges, and we
3577 can build the range test, return it or it inverted. If one of the
3578 ranges is always true or always false, consider it to be the same
3579 expression as the other. */
3580 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
3581 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
3583 && 0 != (tem = (build_range_check (TREE_TYPE (exp),
3585 : rhs != 0 ? rhs : integer_zero_node,
3587 return or_op ? invert_truthvalue (tem) : tem;
3589 /* On machines where the branch cost is expensive, if this is a
3590 short-circuited branch and the underlying object on both sides
3591 is the same, make a non-short-circuit operation. */
3592 else if (BRANCH_COST >= 2
3593 && (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3594 || TREE_CODE (exp) == TRUTH_ORIF_EXPR)
3595 && operand_equal_p (lhs, rhs, 0))
3597 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
3598 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
3599 which cases we can't do this. */
3600 if (simple_operand_p (lhs))
3601 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3602 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3603 TREE_TYPE (exp), TREE_OPERAND (exp, 0),
3604 TREE_OPERAND (exp, 1));
3606 else if (global_bindings_p () == 0
3607 && ! contains_placeholder_p (lhs))
3609 tree common = save_expr (lhs);
3611 if (0 != (lhs = build_range_check (TREE_TYPE (exp), common,
3612 or_op ? ! in0_p : in0_p,
3614 && (0 != (rhs = build_range_check (TREE_TYPE (exp), common,
3615 or_op ? ! in1_p : in1_p,
3617 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3618 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3619 TREE_TYPE (exp), lhs, rhs);
3626 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
3627 bit value. Arrange things so the extra bits will be set to zero if and
3628 only if C is signed-extended to its full width. If MASK is nonzero,
3629 it is an INTEGER_CST that should be AND'ed with the extra bits. */
3632 unextend (c, p, unsignedp, mask)
3638 tree type = TREE_TYPE (c);
3639 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
3642 if (p == modesize || unsignedp)
3645 /* We work by getting just the sign bit into the low-order bit, then
3646 into the high-order bit, then sign-extend. We then XOR that value
3648 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
3649 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
3651 /* We must use a signed type in order to get an arithmetic right shift.
3652 However, we must also avoid introducing accidental overflows, so that
3653 a subsequent call to integer_zerop will work. Hence we must
3654 do the type conversion here. At this point, the constant is either
3655 zero or one, and the conversion to a signed type can never overflow.
3656 We could get an overflow if this conversion is done anywhere else. */
3657 if (TREE_UNSIGNED (type))
3658 temp = convert (signed_type (type), temp);
3660 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
3661 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
3663 temp = const_binop (BIT_AND_EXPR, temp, convert (TREE_TYPE (c), mask), 0);
3664 /* If necessary, convert the type back to match the type of C. */
3665 if (TREE_UNSIGNED (type))
3666 temp = convert (type, temp);
3668 return convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
3671 /* Find ways of folding logical expressions of LHS and RHS:
3672 Try to merge two comparisons to the same innermost item.
3673 Look for range tests like "ch >= '0' && ch <= '9'".
3674 Look for combinations of simple terms on machines with expensive branches
3675 and evaluate the RHS unconditionally.
3677 For example, if we have p->a == 2 && p->b == 4 and we can make an
3678 object large enough to span both A and B, we can do this with a comparison
3679 against the object ANDed with the a mask.
3681 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
3682 operations to do this with one comparison.
3684 We check for both normal comparisons and the BIT_AND_EXPRs made this by
3685 function and the one above.
3687 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
3688 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
3690 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
3693 We return the simplified tree or 0 if no optimization is possible. */
3696 fold_truthop (code, truth_type, lhs, rhs)
3697 enum tree_code code;
3698 tree truth_type, lhs, rhs;
3700 /* If this is the "or" of two comparisons, we can do something if we
3701 the comparisons are NE_EXPR. If this is the "and", we can do something
3702 if the comparisons are EQ_EXPR. I.e.,
3703 (a->b == 2 && a->c == 4) can become (a->new == NEW).
3705 WANTED_CODE is this operation code. For single bit fields, we can
3706 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
3707 comparison for one-bit fields. */
3709 enum tree_code wanted_code;
3710 enum tree_code lcode, rcode;
3711 tree ll_arg, lr_arg, rl_arg, rr_arg;
3712 tree ll_inner, lr_inner, rl_inner, rr_inner;
3713 int ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
3714 int rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
3715 int xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
3716 int lnbitsize, lnbitpos, rnbitsize, rnbitpos;
3717 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
3718 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
3719 enum machine_mode lnmode, rnmode;
3720 tree ll_mask, lr_mask, rl_mask, rr_mask;
3721 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
3722 tree l_const, r_const;
3723 tree lntype, rntype, result;
3724 int first_bit, end_bit;
3727 /* Start by getting the comparison codes. Fail if anything is volatile.
3728 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
3729 it were surrounded with a NE_EXPR. */
3731 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
3734 lcode = TREE_CODE (lhs);
3735 rcode = TREE_CODE (rhs);
3737 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
3738 lcode = NE_EXPR, lhs = build (NE_EXPR, truth_type, lhs, integer_zero_node);
3740 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
3741 rcode = NE_EXPR, rhs = build (NE_EXPR, truth_type, rhs, integer_zero_node);
3743 if (TREE_CODE_CLASS (lcode) != '<' || TREE_CODE_CLASS (rcode) != '<')
3746 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
3747 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
3749 ll_arg = TREE_OPERAND (lhs, 0);
3750 lr_arg = TREE_OPERAND (lhs, 1);
3751 rl_arg = TREE_OPERAND (rhs, 0);
3752 rr_arg = TREE_OPERAND (rhs, 1);
3754 /* If the RHS can be evaluated unconditionally and its operands are
3755 simple, it wins to evaluate the RHS unconditionally on machines
3756 with expensive branches. In this case, this isn't a comparison
3757 that can be merged. */
3759 /* @@ I'm not sure it wins on the m88110 to do this if the comparisons
3760 are with zero (tmw). */
3762 if (BRANCH_COST >= 2
3763 && INTEGRAL_TYPE_P (TREE_TYPE (rhs))
3764 && simple_operand_p (rl_arg)
3765 && simple_operand_p (rr_arg))
3766 return build (code, truth_type, lhs, rhs);
3768 /* See if the comparisons can be merged. Then get all the parameters for
3771 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
3772 || (rcode != EQ_EXPR && rcode != NE_EXPR))
3776 ll_inner = decode_field_reference (ll_arg,
3777 &ll_bitsize, &ll_bitpos, &ll_mode,
3778 &ll_unsignedp, &volatilep, &ll_mask,
3780 lr_inner = decode_field_reference (lr_arg,
3781 &lr_bitsize, &lr_bitpos, &lr_mode,
3782 &lr_unsignedp, &volatilep, &lr_mask,
3784 rl_inner = decode_field_reference (rl_arg,
3785 &rl_bitsize, &rl_bitpos, &rl_mode,
3786 &rl_unsignedp, &volatilep, &rl_mask,
3788 rr_inner = decode_field_reference (rr_arg,
3789 &rr_bitsize, &rr_bitpos, &rr_mode,
3790 &rr_unsignedp, &volatilep, &rr_mask,
3793 /* It must be true that the inner operation on the lhs of each
3794 comparison must be the same if we are to be able to do anything.
3795 Then see if we have constants. If not, the same must be true for
3797 if (volatilep || ll_inner == 0 || rl_inner == 0
3798 || ! operand_equal_p (ll_inner, rl_inner, 0))
3801 if (TREE_CODE (lr_arg) == INTEGER_CST
3802 && TREE_CODE (rr_arg) == INTEGER_CST)
3803 l_const = lr_arg, r_const = rr_arg;
3804 else if (lr_inner == 0 || rr_inner == 0
3805 || ! operand_equal_p (lr_inner, rr_inner, 0))
3808 l_const = r_const = 0;
3810 /* If either comparison code is not correct for our logical operation,
3811 fail. However, we can convert a one-bit comparison against zero into
3812 the opposite comparison against that bit being set in the field. */
3814 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
3815 if (lcode != wanted_code)
3817 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
3819 /* Make the left operand unsigned, since we are only interested
3820 in the value of one bit. Otherwise we are doing the wrong
3829 /* This is analogous to the code for l_const above. */
3830 if (rcode != wanted_code)
3832 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
3841 /* See if we can find a mode that contains both fields being compared on
3842 the left. If we can't, fail. Otherwise, update all constants and masks
3843 to be relative to a field of that size. */
3844 first_bit = MIN (ll_bitpos, rl_bitpos);
3845 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
3846 lnmode = get_best_mode (end_bit - first_bit, first_bit,
3847 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
3849 if (lnmode == VOIDmode)
3852 lnbitsize = GET_MODE_BITSIZE (lnmode);
3853 lnbitpos = first_bit & ~ (lnbitsize - 1);
3854 lntype = type_for_size (lnbitsize, 1);
3855 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
3857 if (BYTES_BIG_ENDIAN)
3859 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
3860 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
3863 ll_mask = const_binop (LSHIFT_EXPR, convert (lntype, ll_mask),
3864 size_int (xll_bitpos), 0);
3865 rl_mask = const_binop (LSHIFT_EXPR, convert (lntype, rl_mask),
3866 size_int (xrl_bitpos), 0);
3870 l_const = convert (lntype, l_const);
3871 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
3872 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
3873 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
3874 fold (build1 (BIT_NOT_EXPR,
3878 warning ("comparison is always %d", wanted_code == NE_EXPR);
3880 return convert (truth_type,
3881 wanted_code == NE_EXPR
3882 ? integer_one_node : integer_zero_node);
3887 r_const = convert (lntype, r_const);
3888 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
3889 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
3890 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
3891 fold (build1 (BIT_NOT_EXPR,
3895 warning ("comparison is always %d", wanted_code == NE_EXPR);
3897 return convert (truth_type,
3898 wanted_code == NE_EXPR
3899 ? integer_one_node : integer_zero_node);
3903 /* If the right sides are not constant, do the same for it. Also,
3904 disallow this optimization if a size or signedness mismatch occurs
3905 between the left and right sides. */
3908 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
3909 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
3910 /* Make sure the two fields on the right
3911 correspond to the left without being swapped. */
3912 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
3915 first_bit = MIN (lr_bitpos, rr_bitpos);
3916 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
3917 rnmode = get_best_mode (end_bit - first_bit, first_bit,
3918 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
3920 if (rnmode == VOIDmode)
3923 rnbitsize = GET_MODE_BITSIZE (rnmode);
3924 rnbitpos = first_bit & ~ (rnbitsize - 1);
3925 rntype = type_for_size (rnbitsize, 1);
3926 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
3928 if (BYTES_BIG_ENDIAN)
3930 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
3931 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
3934 lr_mask = const_binop (LSHIFT_EXPR, convert (rntype, lr_mask),
3935 size_int (xlr_bitpos), 0);
3936 rr_mask = const_binop (LSHIFT_EXPR, convert (rntype, rr_mask),
3937 size_int (xrr_bitpos), 0);
3939 /* Make a mask that corresponds to both fields being compared.
3940 Do this for both items being compared. If the operands are the
3941 same size and the bits being compared are in the same position
3942 then we can do this by masking both and comparing the masked
3944 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
3945 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
3946 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
3948 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
3949 ll_unsignedp || rl_unsignedp);
3950 if (! all_ones_mask_p (ll_mask, lnbitsize))
3951 lhs = build (BIT_AND_EXPR, lntype, lhs, ll_mask);
3953 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
3954 lr_unsignedp || rr_unsignedp);
3955 if (! all_ones_mask_p (lr_mask, rnbitsize))
3956 rhs = build (BIT_AND_EXPR, rntype, rhs, lr_mask);
3958 return build (wanted_code, truth_type, lhs, rhs);
3961 /* There is still another way we can do something: If both pairs of
3962 fields being compared are adjacent, we may be able to make a wider
3963 field containing them both.
3965 Note that we still must mask the lhs/rhs expressions. Furthermore,
3966 the mask must be shifted to account for the shift done by
3967 make_bit_field_ref. */
3968 if ((ll_bitsize + ll_bitpos == rl_bitpos
3969 && lr_bitsize + lr_bitpos == rr_bitpos)
3970 || (ll_bitpos == rl_bitpos + rl_bitsize
3971 && lr_bitpos == rr_bitpos + rr_bitsize))
3975 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
3976 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
3977 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
3978 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
3980 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
3981 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
3982 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
3983 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
3985 /* Convert to the smaller type before masking out unwanted bits. */
3987 if (lntype != rntype)
3989 if (lnbitsize > rnbitsize)
3991 lhs = convert (rntype, lhs);
3992 ll_mask = convert (rntype, ll_mask);
3995 else if (lnbitsize < rnbitsize)
3997 rhs = convert (lntype, rhs);
3998 lr_mask = convert (lntype, lr_mask);
4003 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
4004 lhs = build (BIT_AND_EXPR, type, lhs, ll_mask);
4006 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
4007 rhs = build (BIT_AND_EXPR, type, rhs, lr_mask);
4009 return build (wanted_code, truth_type, lhs, rhs);
4015 /* Handle the case of comparisons with constants. If there is something in
4016 common between the masks, those bits of the constants must be the same.
4017 If not, the condition is always false. Test for this to avoid generating
4018 incorrect code below. */
4019 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
4020 if (! integer_zerop (result)
4021 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
4022 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
4024 if (wanted_code == NE_EXPR)
4026 warning ("`or' of unmatched not-equal tests is always 1");
4027 return convert (truth_type, integer_one_node);
4031 warning ("`and' of mutually exclusive equal-tests is always 0");
4032 return convert (truth_type, integer_zero_node);
4036 /* Construct the expression we will return. First get the component
4037 reference we will make. Unless the mask is all ones the width of
4038 that field, perform the mask operation. Then compare with the
4040 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4041 ll_unsignedp || rl_unsignedp);
4043 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4044 if (! all_ones_mask_p (ll_mask, lnbitsize))
4045 result = build (BIT_AND_EXPR, lntype, result, ll_mask);
4047 return build (wanted_code, truth_type, result,
4048 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
4051 /* If T contains a COMPOUND_EXPR which was inserted merely to evaluate
4052 S, a SAVE_EXPR, return the expression actually being evaluated. Note
4053 that we may sometimes modify the tree. */
4056 strip_compound_expr (t, s)
4060 enum tree_code code = TREE_CODE (t);
4062 /* See if this is the COMPOUND_EXPR we want to eliminate. */
4063 if (code == COMPOUND_EXPR && TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR
4064 && TREE_OPERAND (TREE_OPERAND (t, 0), 0) == s)
4065 return TREE_OPERAND (t, 1);
4067 /* See if this is a COND_EXPR or a simple arithmetic operator. We
4068 don't bother handling any other types. */
4069 else if (code == COND_EXPR)
4071 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4072 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4073 TREE_OPERAND (t, 2) = strip_compound_expr (TREE_OPERAND (t, 2), s);
4075 else if (TREE_CODE_CLASS (code) == '1')
4076 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4077 else if (TREE_CODE_CLASS (code) == '<'
4078 || TREE_CODE_CLASS (code) == '2')
4080 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4081 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4087 /* Return a node which has the indicated constant VALUE (either 0 or
4088 1), and is of the indicated TYPE. */
4091 constant_boolean_node (value, type)
4095 if (type == integer_type_node)
4096 return value ? integer_one_node : integer_zero_node;
4097 else if (TREE_CODE (type) == BOOLEAN_TYPE)
4098 return truthvalue_conversion (value ? integer_one_node :
4102 tree t = build_int_2 (value, 0);
4103 TREE_TYPE (t) = type;
4108 /* Utility function for the following routine, to see how complex a nesting of
4109 COND_EXPRs can be. EXPR is the expression and LIMIT is a count beyond which
4110 we don't care (to avoid spending too much time on complex expressions.). */
4113 count_cond (expr, lim)
4119 if (TREE_CODE (expr) != COND_EXPR)
4124 true = count_cond (TREE_OPERAND (expr, 1), lim - 1);
4125 false = count_cond (TREE_OPERAND (expr, 2), lim - 1 - true);
4126 return MIN (lim, 1 + true + false);
4129 /* Perform constant folding and related simplification of EXPR.
4130 The related simplifications include x*1 => x, x*0 => 0, etc.,
4131 and application of the associative law.
4132 NOP_EXPR conversions may be removed freely (as long as we
4133 are careful not to change the C type of the overall expression)
4134 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
4135 but we can constant-fold them if they have constant operands. */
4141 register tree t = expr;
4142 tree t1 = NULL_TREE;
4144 tree type = TREE_TYPE (expr);
4145 register tree arg0 = NULL_TREE, arg1 = NULL_TREE;
4146 register enum tree_code code = TREE_CODE (t);
4150 /* WINS will be nonzero when the switch is done
4151 if all operands are constant. */
4155 /* Don't try to process an RTL_EXPR since its operands aren't trees.
4156 Likewise for a SAVE_EXPR that's already been evaluated. */
4157 if (code == RTL_EXPR || (code == SAVE_EXPR && SAVE_EXPR_RTL (t)) != 0)
4160 /* Return right away if already constant. */
4161 if (TREE_CONSTANT (t))
4163 if (code == CONST_DECL)
4164 return DECL_INITIAL (t);
4168 #ifdef MAX_INTEGER_COMPUTATION_MODE
4169 check_max_integer_computation_mode (expr);
4172 kind = TREE_CODE_CLASS (code);
4173 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
4177 /* Special case for conversion ops that can have fixed point args. */
4178 arg0 = TREE_OPERAND (t, 0);
4180 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
4182 STRIP_TYPE_NOPS (arg0);
4184 if (arg0 != 0 && TREE_CODE (arg0) == COMPLEX_CST)
4185 subop = TREE_REALPART (arg0);
4189 if (subop != 0 && TREE_CODE (subop) != INTEGER_CST
4190 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
4191 && TREE_CODE (subop) != REAL_CST
4192 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
4194 /* Note that TREE_CONSTANT isn't enough:
4195 static var addresses are constant but we can't
4196 do arithmetic on them. */
4199 else if (kind == 'e' || kind == '<'
4200 || kind == '1' || kind == '2' || kind == 'r')
4202 register int len = tree_code_length[(int) code];
4204 for (i = 0; i < len; i++)
4206 tree op = TREE_OPERAND (t, i);
4210 continue; /* Valid for CALL_EXPR, at least. */
4212 if (kind == '<' || code == RSHIFT_EXPR)
4214 /* Signedness matters here. Perhaps we can refine this
4216 STRIP_TYPE_NOPS (op);
4220 /* Strip any conversions that don't change the mode. */
4224 if (TREE_CODE (op) == COMPLEX_CST)
4225 subop = TREE_REALPART (op);
4229 if (TREE_CODE (subop) != INTEGER_CST
4230 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
4231 && TREE_CODE (subop) != REAL_CST
4232 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
4234 /* Note that TREE_CONSTANT isn't enough:
4235 static var addresses are constant but we can't
4236 do arithmetic on them. */
4246 /* If this is a commutative operation, and ARG0 is a constant, move it
4247 to ARG1 to reduce the number of tests below. */
4248 if ((code == PLUS_EXPR || code == MULT_EXPR || code == MIN_EXPR
4249 || code == MAX_EXPR || code == BIT_IOR_EXPR || code == BIT_XOR_EXPR
4250 || code == BIT_AND_EXPR)
4251 && (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST))
4253 tem = arg0; arg0 = arg1; arg1 = tem;
4255 tem = TREE_OPERAND (t, 0); TREE_OPERAND (t, 0) = TREE_OPERAND (t, 1);
4256 TREE_OPERAND (t, 1) = tem;
4259 /* Now WINS is set as described above,
4260 ARG0 is the first operand of EXPR,
4261 and ARG1 is the second operand (if it has more than one operand).
4263 First check for cases where an arithmetic operation is applied to a
4264 compound, conditional, or comparison operation. Push the arithmetic
4265 operation inside the compound or conditional to see if any folding
4266 can then be done. Convert comparison to conditional for this purpose.
4267 The also optimizes non-constant cases that used to be done in
4270 Before we do that, see if this is a BIT_AND_EXPR or a BIT_OR_EXPR,
4271 one of the operands is a comparison and the other is a comparison, a
4272 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
4273 code below would make the expression more complex. Change it to a
4274 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
4275 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
4277 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
4278 || code == EQ_EXPR || code == NE_EXPR)
4279 && ((truth_value_p (TREE_CODE (arg0))
4280 && (truth_value_p (TREE_CODE (arg1))
4281 || (TREE_CODE (arg1) == BIT_AND_EXPR
4282 && integer_onep (TREE_OPERAND (arg1, 1)))))
4283 || (truth_value_p (TREE_CODE (arg1))
4284 && (truth_value_p (TREE_CODE (arg0))
4285 || (TREE_CODE (arg0) == BIT_AND_EXPR
4286 && integer_onep (TREE_OPERAND (arg0, 1)))))))
4288 t = fold (build (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
4289 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
4293 if (code == EQ_EXPR)
4294 t = invert_truthvalue (t);
4299 if (TREE_CODE_CLASS (code) == '1')
4301 if (TREE_CODE (arg0) == COMPOUND_EXPR)
4302 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
4303 fold (build1 (code, type, TREE_OPERAND (arg0, 1))));
4304 else if (TREE_CODE (arg0) == COND_EXPR)
4306 t = fold (build (COND_EXPR, type, TREE_OPERAND (arg0, 0),
4307 fold (build1 (code, type, TREE_OPERAND (arg0, 1))),
4308 fold (build1 (code, type, TREE_OPERAND (arg0, 2)))));
4310 /* If this was a conversion, and all we did was to move into
4311 inside the COND_EXPR, bring it back out. But leave it if
4312 it is a conversion from integer to integer and the
4313 result precision is no wider than a word since such a
4314 conversion is cheap and may be optimized away by combine,
4315 while it couldn't if it were outside the COND_EXPR. Then return
4316 so we don't get into an infinite recursion loop taking the
4317 conversion out and then back in. */
4319 if ((code == NOP_EXPR || code == CONVERT_EXPR
4320 || code == NON_LVALUE_EXPR)
4321 && TREE_CODE (t) == COND_EXPR
4322 && TREE_CODE (TREE_OPERAND (t, 1)) == code
4323 && TREE_CODE (TREE_OPERAND (t, 2)) == code
4324 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))
4325 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 2), 0)))
4326 && ! (INTEGRAL_TYPE_P (TREE_TYPE (t))
4327 && INTEGRAL_TYPE_P (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0)))
4328 && TYPE_PRECISION (TREE_TYPE (t)) <= BITS_PER_WORD))
4329 t = build1 (code, type,
4331 TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0)),
4332 TREE_OPERAND (t, 0),
4333 TREE_OPERAND (TREE_OPERAND (t, 1), 0),
4334 TREE_OPERAND (TREE_OPERAND (t, 2), 0)));
4337 else if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<')
4338 return fold (build (COND_EXPR, type, arg0,
4339 fold (build1 (code, type, integer_one_node)),
4340 fold (build1 (code, type, integer_zero_node))));
4342 else if (TREE_CODE_CLASS (code) == '2'
4343 || TREE_CODE_CLASS (code) == '<')
4345 if (TREE_CODE (arg1) == COMPOUND_EXPR)
4346 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
4347 fold (build (code, type,
4348 arg0, TREE_OPERAND (arg1, 1))));
4349 else if ((TREE_CODE (arg1) == COND_EXPR
4350 || (TREE_CODE_CLASS (TREE_CODE (arg1)) == '<'
4351 && TREE_CODE_CLASS (code) != '<'))
4352 && (TREE_CODE (arg0) != COND_EXPR
4353 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
4354 && (! TREE_SIDE_EFFECTS (arg0)
4355 || (global_bindings_p () == 0
4356 && ! contains_placeholder_p (arg0))))
4358 tree test, true_value, false_value;
4359 tree lhs = 0, rhs = 0;
4361 if (TREE_CODE (arg1) == COND_EXPR)
4363 test = TREE_OPERAND (arg1, 0);
4364 true_value = TREE_OPERAND (arg1, 1);
4365 false_value = TREE_OPERAND (arg1, 2);
4369 tree testtype = TREE_TYPE (arg1);
4371 true_value = convert (testtype, integer_one_node);
4372 false_value = convert (testtype, integer_zero_node);
4375 /* If ARG0 is complex we want to make sure we only evaluate
4376 it once. Though this is only required if it is volatile, it
4377 might be more efficient even if it is not. However, if we
4378 succeed in folding one part to a constant, we do not need
4379 to make this SAVE_EXPR. Since we do this optimization
4380 primarily to see if we do end up with constant and this
4381 SAVE_EXPR interferes with later optimizations, suppressing
4382 it when we can is important.
4384 If we are not in a function, we can't make a SAVE_EXPR, so don't
4385 try to do so. Don't try to see if the result is a constant
4386 if an arm is a COND_EXPR since we get exponential behavior
4389 if (TREE_CODE (arg0) != SAVE_EXPR && ! TREE_CONSTANT (arg0)
4390 && global_bindings_p () == 0
4391 && ((TREE_CODE (arg0) != VAR_DECL
4392 && TREE_CODE (arg0) != PARM_DECL)
4393 || TREE_SIDE_EFFECTS (arg0)))
4395 if (TREE_CODE (true_value) != COND_EXPR)
4396 lhs = fold (build (code, type, arg0, true_value));
4398 if (TREE_CODE (false_value) != COND_EXPR)
4399 rhs = fold (build (code, type, arg0, false_value));
4401 if ((lhs == 0 || ! TREE_CONSTANT (lhs))
4402 && (rhs == 0 || !TREE_CONSTANT (rhs)))
4403 arg0 = save_expr (arg0), lhs = rhs = 0;
4407 lhs = fold (build (code, type, arg0, true_value));
4409 rhs = fold (build (code, type, arg0, false_value));
4411 test = fold (build (COND_EXPR, type, test, lhs, rhs));
4413 if (TREE_CODE (arg0) == SAVE_EXPR)
4414 return build (COMPOUND_EXPR, type,
4415 convert (void_type_node, arg0),
4416 strip_compound_expr (test, arg0));
4418 return convert (type, test);
4421 else if (TREE_CODE (arg0) == COMPOUND_EXPR)
4422 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
4423 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
4424 else if ((TREE_CODE (arg0) == COND_EXPR
4425 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
4426 && TREE_CODE_CLASS (code) != '<'))
4427 && (TREE_CODE (arg1) != COND_EXPR
4428 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
4429 && (! TREE_SIDE_EFFECTS (arg1)
4430 || (global_bindings_p () == 0
4431 && ! contains_placeholder_p (arg1))))
4433 tree test, true_value, false_value;
4434 tree lhs = 0, rhs = 0;
4436 if (TREE_CODE (arg0) == COND_EXPR)
4438 test = TREE_OPERAND (arg0, 0);
4439 true_value = TREE_OPERAND (arg0, 1);
4440 false_value = TREE_OPERAND (arg0, 2);
4444 tree testtype = TREE_TYPE (arg0);
4446 true_value = convert (testtype, integer_one_node);
4447 false_value = convert (testtype, integer_zero_node);
4450 if (TREE_CODE (arg1) != SAVE_EXPR && ! TREE_CONSTANT (arg0)
4451 && global_bindings_p () == 0
4452 && ((TREE_CODE (arg1) != VAR_DECL
4453 && TREE_CODE (arg1) != PARM_DECL)
4454 || TREE_SIDE_EFFECTS (arg1)))
4456 if (TREE_CODE (true_value) != COND_EXPR)
4457 lhs = fold (build (code, type, true_value, arg1));
4459 if (TREE_CODE (false_value) != COND_EXPR)
4460 rhs = fold (build (code, type, false_value, arg1));
4462 if ((lhs == 0 || ! TREE_CONSTANT (lhs))
4463 && (rhs == 0 || !TREE_CONSTANT (rhs)))
4464 arg1 = save_expr (arg1), lhs = rhs = 0;
4468 lhs = fold (build (code, type, true_value, arg1));
4471 rhs = fold (build (code, type, false_value, arg1));
4473 test = fold (build (COND_EXPR, type, test, lhs, rhs));
4474 if (TREE_CODE (arg1) == SAVE_EXPR)
4475 return build (COMPOUND_EXPR, type,
4476 convert (void_type_node, arg1),
4477 strip_compound_expr (test, arg1));
4479 return convert (type, test);
4482 else if (TREE_CODE_CLASS (code) == '<'
4483 && TREE_CODE (arg0) == COMPOUND_EXPR)
4484 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
4485 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
4486 else if (TREE_CODE_CLASS (code) == '<'
4487 && TREE_CODE (arg1) == COMPOUND_EXPR)
4488 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
4489 fold (build (code, type, arg0, TREE_OPERAND (arg1, 1))));
4501 return fold (DECL_INITIAL (t));
4506 case FIX_TRUNC_EXPR:
4507 /* Other kinds of FIX are not handled properly by fold_convert. */
4509 if (TREE_TYPE (TREE_OPERAND (t, 0)) == TREE_TYPE (t))
4510 return TREE_OPERAND (t, 0);
4512 /* Handle cases of two conversions in a row. */
4513 if (TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
4514 || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR)
4516 tree inside_type = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
4517 tree inter_type = TREE_TYPE (TREE_OPERAND (t, 0));
4518 tree final_type = TREE_TYPE (t);
4519 int inside_int = INTEGRAL_TYPE_P (inside_type);
4520 int inside_ptr = POINTER_TYPE_P (inside_type);
4521 int inside_float = FLOAT_TYPE_P (inside_type);
4522 int inside_prec = TYPE_PRECISION (inside_type);
4523 int inside_unsignedp = TREE_UNSIGNED (inside_type);
4524 int inter_int = INTEGRAL_TYPE_P (inter_type);
4525 int inter_ptr = POINTER_TYPE_P (inter_type);
4526 int inter_float = FLOAT_TYPE_P (inter_type);
4527 int inter_prec = TYPE_PRECISION (inter_type);
4528 int inter_unsignedp = TREE_UNSIGNED (inter_type);
4529 int final_int = INTEGRAL_TYPE_P (final_type);
4530 int final_ptr = POINTER_TYPE_P (final_type);
4531 int final_float = FLOAT_TYPE_P (final_type);
4532 int final_prec = TYPE_PRECISION (final_type);
4533 int final_unsignedp = TREE_UNSIGNED (final_type);
4535 /* In addition to the cases of two conversions in a row
4536 handled below, if we are converting something to its own
4537 type via an object of identical or wider precision, neither
4538 conversion is needed. */
4539 if (inside_type == final_type
4540 && ((inter_int && final_int) || (inter_float && final_float))
4541 && inter_prec >= final_prec)
4542 return TREE_OPERAND (TREE_OPERAND (t, 0), 0);
4544 /* Likewise, if the intermediate and final types are either both
4545 float or both integer, we don't need the middle conversion if
4546 it is wider than the final type and doesn't change the signedness
4547 (for integers). Avoid this if the final type is a pointer
4548 since then we sometimes need the inner conversion. Likewise if
4549 the outer has a precision not equal to the size of its mode. */
4550 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
4551 || (inter_float && inside_float))
4552 && inter_prec >= inside_prec
4553 && (inter_float || inter_unsignedp == inside_unsignedp)
4554 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
4555 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
4557 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
4559 /* If we have a sign-extension of a zero-extended value, we can
4560 replace that by a single zero-extension. */
4561 if (inside_int && inter_int && final_int
4562 && inside_prec < inter_prec && inter_prec < final_prec
4563 && inside_unsignedp && !inter_unsignedp)
4564 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
4566 /* Two conversions in a row are not needed unless:
4567 - some conversion is floating-point (overstrict for now), or
4568 - the intermediate type is narrower than both initial and
4570 - the intermediate type and innermost type differ in signedness,
4571 and the outermost type is wider than the intermediate, or
4572 - the initial type is a pointer type and the precisions of the
4573 intermediate and final types differ, or
4574 - the final type is a pointer type and the precisions of the
4575 initial and intermediate types differ. */
4576 if (! inside_float && ! inter_float && ! final_float
4577 && (inter_prec > inside_prec || inter_prec > final_prec)
4578 && ! (inside_int && inter_int
4579 && inter_unsignedp != inside_unsignedp
4580 && inter_prec < final_prec)
4581 && ((inter_unsignedp && inter_prec > inside_prec)
4582 == (final_unsignedp && final_prec > inter_prec))
4583 && ! (inside_ptr && inter_prec != final_prec)
4584 && ! (final_ptr && inside_prec != inter_prec)
4585 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
4586 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
4588 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
4591 if (TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR
4592 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t, 0), 1))
4593 /* Detect assigning a bitfield. */
4594 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) == COMPONENT_REF
4595 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 1))))
4597 /* Don't leave an assignment inside a conversion
4598 unless assigning a bitfield. */
4599 tree prev = TREE_OPERAND (t, 0);
4600 TREE_OPERAND (t, 0) = TREE_OPERAND (prev, 1);
4601 /* First do the assignment, then return converted constant. */
4602 t = build (COMPOUND_EXPR, TREE_TYPE (t), prev, fold (t));
4608 TREE_CONSTANT (t) = TREE_CONSTANT (arg0);
4611 return fold_convert (t, arg0);
4613 #if 0 /* This loses on &"foo"[0]. */
4618 /* Fold an expression like: "foo"[2] */
4619 if (TREE_CODE (arg0) == STRING_CST
4620 && TREE_CODE (arg1) == INTEGER_CST
4621 && !TREE_INT_CST_HIGH (arg1)
4622 && (i = TREE_INT_CST_LOW (arg1)) < TREE_STRING_LENGTH (arg0))
4624 t = build_int_2 (TREE_STRING_POINTER (arg0)[i], 0);
4625 TREE_TYPE (t) = TREE_TYPE (TREE_TYPE (arg0));
4626 force_fit_type (t, 0);
4633 if (TREE_CODE (arg0) == CONSTRUCTOR)
4635 tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0));
4642 TREE_CONSTANT (t) = wins;
4648 if (TREE_CODE (arg0) == INTEGER_CST)
4650 HOST_WIDE_INT low, high;
4651 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
4652 TREE_INT_CST_HIGH (arg0),
4654 t = build_int_2 (low, high);
4655 TREE_TYPE (t) = type;
4657 = (TREE_OVERFLOW (arg0)
4658 | force_fit_type (t, overflow && !TREE_UNSIGNED (type)));
4659 TREE_CONSTANT_OVERFLOW (t)
4660 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
4662 else if (TREE_CODE (arg0) == REAL_CST)
4663 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
4665 else if (TREE_CODE (arg0) == NEGATE_EXPR)
4666 return TREE_OPERAND (arg0, 0);
4668 /* Convert - (a - b) to (b - a) for non-floating-point. */
4669 else if (TREE_CODE (arg0) == MINUS_EXPR && ! FLOAT_TYPE_P (type))
4670 return build (MINUS_EXPR, type, TREE_OPERAND (arg0, 1),
4671 TREE_OPERAND (arg0, 0));
4678 if (TREE_CODE (arg0) == INTEGER_CST)
4680 if (! TREE_UNSIGNED (type)
4681 && TREE_INT_CST_HIGH (arg0) < 0)
4683 HOST_WIDE_INT low, high;
4684 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
4685 TREE_INT_CST_HIGH (arg0),
4687 t = build_int_2 (low, high);
4688 TREE_TYPE (t) = type;
4690 = (TREE_OVERFLOW (arg0)
4691 | force_fit_type (t, overflow));
4692 TREE_CONSTANT_OVERFLOW (t)
4693 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
4696 else if (TREE_CODE (arg0) == REAL_CST)
4698 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
4699 t = build_real (type,
4700 REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
4703 else if (TREE_CODE (arg0) == ABS_EXPR || TREE_CODE (arg0) == NEGATE_EXPR)
4704 return build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0));
4708 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
4710 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
4711 return build (COMPLEX_EXPR, TREE_TYPE (arg0),
4712 TREE_OPERAND (arg0, 0),
4713 fold (build1 (NEGATE_EXPR,
4714 TREE_TYPE (TREE_TYPE (arg0)),
4715 TREE_OPERAND (arg0, 1))));
4716 else if (TREE_CODE (arg0) == COMPLEX_CST)
4717 return build_complex (type, TREE_OPERAND (arg0, 0),
4718 fold (build1 (NEGATE_EXPR,
4719 TREE_TYPE (TREE_TYPE (arg0)),
4720 TREE_OPERAND (arg0, 1))));
4721 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
4722 return fold (build (TREE_CODE (arg0), type,
4723 fold (build1 (CONJ_EXPR, type,
4724 TREE_OPERAND (arg0, 0))),
4725 fold (build1 (CONJ_EXPR,
4726 type, TREE_OPERAND (arg0, 1)))));
4727 else if (TREE_CODE (arg0) == CONJ_EXPR)
4728 return TREE_OPERAND (arg0, 0);
4734 t = build_int_2 (~ TREE_INT_CST_LOW (arg0),
4735 ~ TREE_INT_CST_HIGH (arg0));
4736 TREE_TYPE (t) = type;
4737 force_fit_type (t, 0);
4738 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg0);
4739 TREE_CONSTANT_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (arg0);
4741 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
4742 return TREE_OPERAND (arg0, 0);
4746 /* A + (-B) -> A - B */
4747 if (TREE_CODE (arg1) == NEGATE_EXPR)
4748 return fold (build (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
4749 else if (! FLOAT_TYPE_P (type))
4751 if (integer_zerop (arg1))
4752 return non_lvalue (convert (type, arg0));
4754 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
4755 with a constant, and the two constants have no bits in common,
4756 we should treat this as a BIT_IOR_EXPR since this may produce more
4758 if (TREE_CODE (arg0) == BIT_AND_EXPR
4759 && TREE_CODE (arg1) == BIT_AND_EXPR
4760 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
4761 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
4762 && integer_zerop (const_binop (BIT_AND_EXPR,
4763 TREE_OPERAND (arg0, 1),
4764 TREE_OPERAND (arg1, 1), 0)))
4766 code = BIT_IOR_EXPR;
4770 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
4771 (plus (plus (mult) (mult)) (foo)) so that we can
4772 take advantage of the factoring cases below. */
4773 if ((TREE_CODE (arg0) == PLUS_EXPR
4774 && TREE_CODE (arg1) == MULT_EXPR)
4775 || (TREE_CODE (arg1) == PLUS_EXPR
4776 && TREE_CODE (arg0) == MULT_EXPR))
4778 tree parg0, parg1, parg, marg;
4780 if (TREE_CODE (arg0) == PLUS_EXPR)
4781 parg = arg0, marg = arg1;
4783 parg = arg1, marg = arg0;
4784 parg0 = TREE_OPERAND (parg, 0);
4785 parg1 = TREE_OPERAND (parg, 1);
4789 if (TREE_CODE (parg0) == MULT_EXPR
4790 && TREE_CODE (parg1) != MULT_EXPR)
4791 return fold (build (PLUS_EXPR, type,
4792 fold (build (PLUS_EXPR, type, parg0, marg)),
4794 if (TREE_CODE (parg0) != MULT_EXPR
4795 && TREE_CODE (parg1) == MULT_EXPR)
4796 return fold (build (PLUS_EXPR, type,
4797 fold (build (PLUS_EXPR, type, parg1, marg)),
4801 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR)
4803 tree arg00, arg01, arg10, arg11;
4804 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
4806 /* (A * C) + (B * C) -> (A+B) * C.
4807 We are most concerned about the case where C is a constant,
4808 but other combinations show up during loop reduction. Since
4809 it is not difficult, try all four possibilities. */
4811 arg00 = TREE_OPERAND (arg0, 0);
4812 arg01 = TREE_OPERAND (arg0, 1);
4813 arg10 = TREE_OPERAND (arg1, 0);
4814 arg11 = TREE_OPERAND (arg1, 1);
4817 if (operand_equal_p (arg01, arg11, 0))
4818 same = arg01, alt0 = arg00, alt1 = arg10;
4819 else if (operand_equal_p (arg00, arg10, 0))
4820 same = arg00, alt0 = arg01, alt1 = arg11;
4821 else if (operand_equal_p (arg00, arg11, 0))
4822 same = arg00, alt0 = arg01, alt1 = arg10;
4823 else if (operand_equal_p (arg01, arg10, 0))
4824 same = arg01, alt0 = arg00, alt1 = arg11;
4826 /* No identical multiplicands; see if we can find a common
4827 power-of-two factor in non-power-of-two multiplies. This
4828 can help in multi-dimensional array access. */
4829 else if (TREE_CODE (arg01) == INTEGER_CST
4830 && TREE_CODE (arg11) == INTEGER_CST
4831 && TREE_INT_CST_HIGH (arg01) == 0
4832 && TREE_INT_CST_HIGH (arg11) == 0)
4834 HOST_WIDE_INT int01, int11, tmp;
4835 int01 = TREE_INT_CST_LOW (arg01);
4836 int11 = TREE_INT_CST_LOW (arg11);
4838 /* Move min of absolute values to int11. */
4839 if ((int01 >= 0 ? int01 : -int01)
4840 < (int11 >= 0 ? int11 : -int11))
4842 tmp = int01, int01 = int11, int11 = tmp;
4843 alt0 = arg00, arg00 = arg10, arg10 = alt0;
4844 alt0 = arg01, arg01 = arg11, arg11 = alt0;
4847 if (exact_log2 (int11) > 0 && int01 % int11 == 0)
4849 alt0 = fold (build (MULT_EXPR, type, arg00,
4850 build_int_2 (int01 / int11, 0)));
4857 return fold (build (MULT_EXPR, type,
4858 fold (build (PLUS_EXPR, type, alt0, alt1)),
4862 /* In IEEE floating point, x+0 may not equal x. */
4863 else if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
4865 && real_zerop (arg1))
4866 return non_lvalue (convert (type, arg0));
4868 /* In most languages, can't associate operations on floats
4869 through parentheses. Rather than remember where the parentheses
4870 were, we don't associate floats at all. It shouldn't matter much.
4871 However, associating multiplications is only very slightly
4872 inaccurate, so do that if -ffast-math is specified. */
4873 if (FLOAT_TYPE_P (type)
4874 && ! (flag_fast_math && code == MULT_EXPR))
4877 /* The varsign == -1 cases happen only for addition and subtraction.
4878 It says that the arg that was split was really CON minus VAR.
4879 The rest of the code applies to all associative operations. */
4885 if (split_tree (arg0, code, &var, &con, &varsign))
4889 /* EXPR is (CON-VAR) +- ARG1. */
4890 /* If it is + and VAR==ARG1, return just CONST. */
4891 if (code == PLUS_EXPR && operand_equal_p (var, arg1, 0))
4892 return convert (TREE_TYPE (t), con);
4894 /* If ARG0 is a constant, don't change things around;
4895 instead keep all the constant computations together. */
4897 if (TREE_CONSTANT (arg0))
4900 /* Otherwise return (CON +- ARG1) - VAR. */
4901 t = build (MINUS_EXPR, type,
4902 fold (build (code, type, con, arg1)), var);
4906 /* EXPR is (VAR+CON) +- ARG1. */
4907 /* If it is - and VAR==ARG1, return just CONST. */
4908 if (code == MINUS_EXPR && operand_equal_p (var, arg1, 0))
4909 return convert (TREE_TYPE (t), con);
4911 /* If ARG0 is a constant, don't change things around;
4912 instead keep all the constant computations together. */
4914 if (TREE_CONSTANT (arg0))
4917 /* Otherwise return VAR +- (ARG1 +- CON). */
4918 tem = fold (build (code, type, arg1, con));
4919 t = build (code, type, var, tem);
4921 if (integer_zerop (tem)
4922 && (code == PLUS_EXPR || code == MINUS_EXPR))
4923 return convert (type, var);
4924 /* If we have x +/- (c - d) [c an explicit integer]
4925 change it to x -/+ (d - c) since if d is relocatable
4926 then the latter can be a single immediate insn
4927 and the former cannot. */
4928 if (TREE_CODE (tem) == MINUS_EXPR
4929 && TREE_CODE (TREE_OPERAND (tem, 0)) == INTEGER_CST)
4931 tree tem1 = TREE_OPERAND (tem, 1);
4932 TREE_OPERAND (tem, 1) = TREE_OPERAND (tem, 0);
4933 TREE_OPERAND (tem, 0) = tem1;
4935 (code == PLUS_EXPR ? MINUS_EXPR : PLUS_EXPR));
4941 if (split_tree (arg1, code, &var, &con, &varsign))
4943 if (TREE_CONSTANT (arg1))
4948 (code == PLUS_EXPR ? MINUS_EXPR : PLUS_EXPR));
4950 /* EXPR is ARG0 +- (CON +- VAR). */
4951 if (TREE_CODE (t) == MINUS_EXPR
4952 && operand_equal_p (var, arg0, 0))
4954 /* If VAR and ARG0 cancel, return just CON or -CON. */
4955 if (code == PLUS_EXPR)
4956 return convert (TREE_TYPE (t), con);
4957 return fold (build1 (NEGATE_EXPR, TREE_TYPE (t),
4958 convert (TREE_TYPE (t), con)));
4961 t = build (TREE_CODE (t), type,
4962 fold (build (code, TREE_TYPE (t), arg0, con)), var);
4964 if (integer_zerop (TREE_OPERAND (t, 0))
4965 && TREE_CODE (t) == PLUS_EXPR)
4966 return convert (TREE_TYPE (t), var);
4971 #if defined (REAL_IS_NOT_DOUBLE) && ! defined (REAL_ARITHMETIC)
4972 if (TREE_CODE (arg1) == REAL_CST)
4974 #endif /* REAL_IS_NOT_DOUBLE, and no REAL_ARITHMETIC */
4976 t1 = const_binop (code, arg0, arg1, 0);
4977 if (t1 != NULL_TREE)
4979 /* The return value should always have
4980 the same type as the original expression. */
4981 if (TREE_TYPE (t1) != TREE_TYPE (t))
4982 t1 = convert (TREE_TYPE (t), t1);
4989 if (! FLOAT_TYPE_P (type))
4991 if (! wins && integer_zerop (arg0))
4992 return build1 (NEGATE_EXPR, type, arg1);
4993 if (integer_zerop (arg1))
4994 return non_lvalue (convert (type, arg0));
4996 /* (A * C) - (B * C) -> (A-B) * C. Since we are most concerned
4997 about the case where C is a constant, just try one of the
4998 four possibilities. */
5000 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR
5001 && operand_equal_p (TREE_OPERAND (arg0, 1),
5002 TREE_OPERAND (arg1, 1), 0))
5003 return fold (build (MULT_EXPR, type,
5004 fold (build (MINUS_EXPR, type,
5005 TREE_OPERAND (arg0, 0),
5006 TREE_OPERAND (arg1, 0))),
5007 TREE_OPERAND (arg0, 1)));
5009 /* Convert A - (-B) to A + B. */
5010 else if (TREE_CODE (arg1) == NEGATE_EXPR)
5011 return fold (build (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5013 else if (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
5016 /* Except with IEEE floating point, 0-x equals -x. */
5017 if (! wins && real_zerop (arg0))
5018 return build1 (NEGATE_EXPR, type, arg1);
5019 /* Except with IEEE floating point, x-0 equals x. */
5020 if (real_zerop (arg1))
5021 return non_lvalue (convert (type, arg0));
5024 /* Fold &x - &x. This can happen from &x.foo - &x.
5025 This is unsafe for certain floats even in non-IEEE formats.
5026 In IEEE, it is unsafe because it does wrong for NaNs.
5027 Also note that operand_equal_p is always false if an operand
5030 if ((! FLOAT_TYPE_P (type) || flag_fast_math)
5031 && operand_equal_p (arg0, arg1, 0))
5032 return convert (type, integer_zero_node);
5037 if (! FLOAT_TYPE_P (type))
5039 if (integer_zerop (arg1))
5040 return omit_one_operand (type, arg1, arg0);
5041 if (integer_onep (arg1))
5042 return non_lvalue (convert (type, arg0));
5044 /* ((A / C) * C) is A if the division is an
5045 EXACT_DIV_EXPR. Since C is normally a constant,
5046 just check for one of the four possibilities. */
5048 if (TREE_CODE (arg0) == EXACT_DIV_EXPR
5049 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
5050 return TREE_OPERAND (arg0, 0);
5052 /* (a * (1 << b)) is (a << b) */
5053 if (TREE_CODE (arg1) == LSHIFT_EXPR
5054 && integer_onep (TREE_OPERAND (arg1, 0)))
5055 return fold (build (LSHIFT_EXPR, type, arg0,
5056 TREE_OPERAND (arg1, 1)));
5057 if (TREE_CODE (arg0) == LSHIFT_EXPR
5058 && integer_onep (TREE_OPERAND (arg0, 0)))
5059 return fold (build (LSHIFT_EXPR, type, arg1,
5060 TREE_OPERAND (arg0, 1)));
5064 /* x*0 is 0, except for IEEE floating point. */
5065 if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
5067 && real_zerop (arg1))
5068 return omit_one_operand (type, arg1, arg0);
5069 /* In IEEE floating point, x*1 is not equivalent to x for snans.
5070 However, ANSI says we can drop signals,
5071 so we can do this anyway. */
5072 if (real_onep (arg1))
5073 return non_lvalue (convert (type, arg0));
5075 if (! wins && real_twop (arg1) && global_bindings_p () == 0
5076 && ! contains_placeholder_p (arg0))
5078 tree arg = save_expr (arg0);
5079 return build (PLUS_EXPR, type, arg, arg);
5087 register enum tree_code code0, code1;
5089 if (integer_all_onesp (arg1))
5090 return omit_one_operand (type, arg1, arg0);
5091 if (integer_zerop (arg1))
5092 return non_lvalue (convert (type, arg0));
5093 t1 = distribute_bit_expr (code, type, arg0, arg1);
5094 if (t1 != NULL_TREE)
5097 /* (A << C1) | (A >> C2) if A is unsigned and C1+C2 is the size of A
5098 is a rotate of A by C1 bits. */
5099 /* (A << B) | (A >> (Z - B)) if A is unsigned and Z is the size of A
5100 is a rotate of A by B bits. */
5102 code0 = TREE_CODE (arg0);
5103 code1 = TREE_CODE (arg1);
5104 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
5105 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
5106 && operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1,0), 0)
5107 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5109 register tree tree01, tree11;
5110 register enum tree_code code01, code11;
5112 tree01 = TREE_OPERAND (arg0, 1);
5113 tree11 = TREE_OPERAND (arg1, 1);
5114 STRIP_NOPS (tree01);
5115 STRIP_NOPS (tree11);
5116 code01 = TREE_CODE (tree01);
5117 code11 = TREE_CODE (tree11);
5118 if (code01 == INTEGER_CST
5119 && code11 == INTEGER_CST
5120 && TREE_INT_CST_HIGH (tree01) == 0
5121 && TREE_INT_CST_HIGH (tree11) == 0
5122 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
5123 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
5124 return build (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
5125 code0 == LSHIFT_EXPR ? tree01 : tree11);
5126 else if (code11 == MINUS_EXPR)
5128 tree tree110, tree111;
5129 tree110 = TREE_OPERAND (tree11, 0);
5130 tree111 = TREE_OPERAND (tree11, 1);
5131 STRIP_NOPS (tree110);
5132 STRIP_NOPS (tree111);
5133 if (TREE_CODE (tree110) == INTEGER_CST
5134 && TREE_INT_CST_HIGH (tree110) == 0
5135 && (TREE_INT_CST_LOW (tree110)
5136 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5137 && operand_equal_p (tree01, tree111, 0))
5138 return build ((code0 == LSHIFT_EXPR
5141 type, TREE_OPERAND (arg0, 0), tree01);
5143 else if (code01 == MINUS_EXPR)
5145 tree tree010, tree011;
5146 tree010 = TREE_OPERAND (tree01, 0);
5147 tree011 = TREE_OPERAND (tree01, 1);
5148 STRIP_NOPS (tree010);
5149 STRIP_NOPS (tree011);
5150 if (TREE_CODE (tree010) == INTEGER_CST
5151 && TREE_INT_CST_HIGH (tree010) == 0
5152 && (TREE_INT_CST_LOW (tree010)
5153 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5154 && operand_equal_p (tree11, tree011, 0))
5155 return build ((code0 != LSHIFT_EXPR
5158 type, TREE_OPERAND (arg0, 0), tree11);
5166 if (integer_zerop (arg1))
5167 return non_lvalue (convert (type, arg0));
5168 if (integer_all_onesp (arg1))
5169 return fold (build1 (BIT_NOT_EXPR, type, arg0));
5174 if (integer_all_onesp (arg1))
5175 return non_lvalue (convert (type, arg0));
5176 if (integer_zerop (arg1))
5177 return omit_one_operand (type, arg1, arg0);
5178 t1 = distribute_bit_expr (code, type, arg0, arg1);
5179 if (t1 != NULL_TREE)
5181 /* Simplify ((int)c & 0x377) into (int)c, if c is unsigned char. */
5182 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == NOP_EXPR
5183 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg1, 0))))
5185 int prec = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg1, 0)));
5186 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
5187 && (~TREE_INT_CST_LOW (arg0)
5188 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
5189 return build1 (NOP_EXPR, type, TREE_OPERAND (arg1, 0));
5191 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
5192 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5194 int prec = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
5195 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
5196 && (~TREE_INT_CST_LOW (arg1)
5197 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
5198 return build1 (NOP_EXPR, type, TREE_OPERAND (arg0, 0));
5202 case BIT_ANDTC_EXPR:
5203 if (integer_all_onesp (arg0))
5204 return non_lvalue (convert (type, arg1));
5205 if (integer_zerop (arg0))
5206 return omit_one_operand (type, arg0, arg1);
5207 if (TREE_CODE (arg1) == INTEGER_CST)
5209 arg1 = fold (build1 (BIT_NOT_EXPR, type, arg1));
5210 code = BIT_AND_EXPR;
5216 /* In most cases, do nothing with a divide by zero. */
5217 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
5218 #ifndef REAL_INFINITY
5219 if (TREE_CODE (arg1) == REAL_CST && real_zerop (arg1))
5222 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
5224 /* In IEEE floating point, x/1 is not equivalent to x for snans.
5225 However, ANSI says we can drop signals, so we can do this anyway. */
5226 if (real_onep (arg1))
5227 return non_lvalue (convert (type, arg0));
5229 /* If ARG1 is a constant, we can convert this to a multiply by the
5230 reciprocal. This does not have the same rounding properties,
5231 so only do this if -ffast-math. We can actually always safely
5232 do it if ARG1 is a power of two, but it's hard to tell if it is
5233 or not in a portable manner. */
5234 if (TREE_CODE (arg1) == REAL_CST)
5237 && 0 != (tem = const_binop (code, build_real (type, dconst1),
5239 return fold (build (MULT_EXPR, type, arg0, tem));
5240 /* Find the reciprocal if optimizing and the result is exact. */
5244 r = TREE_REAL_CST (arg1);
5245 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
5247 tem = build_real (type, r);
5248 return fold (build (MULT_EXPR, type, arg0, tem));
5254 case TRUNC_DIV_EXPR:
5255 case ROUND_DIV_EXPR:
5256 case FLOOR_DIV_EXPR:
5258 case EXACT_DIV_EXPR:
5259 if (integer_onep (arg1))
5260 return non_lvalue (convert (type, arg0));
5261 if (integer_zerop (arg1))
5264 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
5265 operation, EXACT_DIV_EXPR.
5267 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
5268 At one time others generated faster code, it's not clear if they do
5269 after the last round to changes to the DIV code in expmed.c. */
5270 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
5271 && multiple_of_p (type, arg0, arg1))
5272 return fold (build (EXACT_DIV_EXPR, type, arg0, arg1));
5274 /* If we have ((a / C1) / C2) where both division are the same type, try
5275 to simplify. First see if C1 * C2 overflows or not. */
5276 if (TREE_CODE (arg0) == code && TREE_CODE (arg1) == INTEGER_CST
5277 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
5281 new_divisor = const_binop (MULT_EXPR, TREE_OPERAND (arg0, 1), arg1, 0);
5282 tem = const_binop (FLOOR_DIV_EXPR, new_divisor, arg1, 0);
5284 if (TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) == TREE_INT_CST_LOW (tem)
5285 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == TREE_INT_CST_HIGH (tem))
5287 /* If no overflow, divide by C1*C2. */
5288 return fold (build (code, type, TREE_OPERAND (arg0, 0), new_divisor));
5292 /* Look for ((a * C1) / C3) or (((a * C1) + C2) / C3),
5293 where C1 % C3 == 0 or C3 % C1 == 0. We can simplify these
5294 expressions, which often appear in the offsets or sizes of
5295 objects with a varying size. Only deal with positive divisors
5296 and multiplicands. If C2 is negative, we must have C2 % C3 == 0.
5298 Look for NOPs and SAVE_EXPRs inside. */
5300 if (TREE_CODE (arg1) == INTEGER_CST
5301 && tree_int_cst_sgn (arg1) >= 0)
5303 int have_save_expr = 0;
5304 tree c2 = integer_zero_node;
5307 if (TREE_CODE (xarg0) == SAVE_EXPR && SAVE_EXPR_RTL (xarg0) == 0)
5308 have_save_expr = 1, xarg0 = TREE_OPERAND (xarg0, 0);
5312 /* Look inside the dividend and simplify using EXACT_DIV_EXPR
5314 if (TREE_CODE (xarg0) == MULT_EXPR
5315 && multiple_of_p (type, TREE_OPERAND (xarg0, 0), arg1))
5319 t = fold (build (MULT_EXPR, type,
5320 fold (build (EXACT_DIV_EXPR, type,
5321 TREE_OPERAND (xarg0, 0), arg1)),
5322 TREE_OPERAND (xarg0, 1)));
5329 if (TREE_CODE (xarg0) == MULT_EXPR
5330 && multiple_of_p (type, TREE_OPERAND (xarg0, 1), arg1))
5334 t = fold (build (MULT_EXPR, type,
5335 fold (build (EXACT_DIV_EXPR, type,
5336 TREE_OPERAND (xarg0, 1), arg1)),
5337 TREE_OPERAND (xarg0, 0)));
5343 if (TREE_CODE (xarg0) == PLUS_EXPR
5344 && TREE_CODE (TREE_OPERAND (xarg0, 1)) == INTEGER_CST)
5345 c2 = TREE_OPERAND (xarg0, 1), xarg0 = TREE_OPERAND (xarg0, 0);
5346 else if (TREE_CODE (xarg0) == MINUS_EXPR
5347 && TREE_CODE (TREE_OPERAND (xarg0, 1)) == INTEGER_CST
5348 /* If we are doing this computation unsigned, the negate
5350 && ! TREE_UNSIGNED (type))
5352 c2 = fold (build1 (NEGATE_EXPR, type, TREE_OPERAND (xarg0, 1)));
5353 xarg0 = TREE_OPERAND (xarg0, 0);
5356 if (TREE_CODE (xarg0) == SAVE_EXPR && SAVE_EXPR_RTL (xarg0) == 0)
5357 have_save_expr = 1, xarg0 = TREE_OPERAND (xarg0, 0);
5361 if (TREE_CODE (xarg0) == MULT_EXPR
5362 && TREE_CODE (TREE_OPERAND (xarg0, 1)) == INTEGER_CST
5363 && tree_int_cst_sgn (TREE_OPERAND (xarg0, 1)) >= 0
5364 && (integer_zerop (const_binop (TRUNC_MOD_EXPR,
5365 TREE_OPERAND (xarg0, 1), arg1, 1))
5366 || integer_zerop (const_binop (TRUNC_MOD_EXPR, arg1,
5367 TREE_OPERAND (xarg0, 1), 1)))
5368 && (tree_int_cst_sgn (c2) >= 0
5369 || integer_zerop (const_binop (TRUNC_MOD_EXPR, c2,
5372 tree outer_div = integer_one_node;
5373 tree c1 = TREE_OPERAND (xarg0, 1);
5376 /* If C3 > C1, set them equal and do a divide by
5377 C3/C1 at the end of the operation. */
5378 if (tree_int_cst_lt (c1, c3))
5379 outer_div = const_binop (code, c3, c1, 0), c3 = c1;
5381 /* The result is A * (C1/C3) + (C2/C3). */
5382 t = fold (build (PLUS_EXPR, type,
5383 fold (build (MULT_EXPR, type,
5384 TREE_OPERAND (xarg0, 0),
5385 const_binop (code, c1, c3, 1))),
5386 const_binop (code, c2, c3, 1)));
5388 if (! integer_onep (outer_div))
5389 t = fold (build (code, type, t, convert (type, outer_div)));
5401 case FLOOR_MOD_EXPR:
5402 case ROUND_MOD_EXPR:
5403 case TRUNC_MOD_EXPR:
5404 if (integer_onep (arg1))
5405 return omit_one_operand (type, integer_zero_node, arg0);
5406 if (integer_zerop (arg1))
5409 /* Look for ((a * C1) % C3) or (((a * C1) + C2) % C3),
5410 where C1 % C3 == 0. Handle similarly to the division case,
5411 but don't bother with SAVE_EXPRs. */
5413 if (TREE_CODE (arg1) == INTEGER_CST
5414 && ! integer_zerop (arg1))
5416 tree c2 = integer_zero_node;
5419 if (TREE_CODE (xarg0) == PLUS_EXPR
5420 && TREE_CODE (TREE_OPERAND (xarg0, 1)) == INTEGER_CST)
5421 c2 = TREE_OPERAND (xarg0, 1), xarg0 = TREE_OPERAND (xarg0, 0);
5422 else if (TREE_CODE (xarg0) == MINUS_EXPR
5423 && TREE_CODE (TREE_OPERAND (xarg0, 1)) == INTEGER_CST
5424 && ! TREE_UNSIGNED (type))
5426 c2 = fold (build1 (NEGATE_EXPR, type, TREE_OPERAND (xarg0, 1)));
5427 xarg0 = TREE_OPERAND (xarg0, 0);
5432 if (TREE_CODE (xarg0) == MULT_EXPR
5433 && TREE_CODE (TREE_OPERAND (xarg0, 1)) == INTEGER_CST
5434 && integer_zerop (const_binop (TRUNC_MOD_EXPR,
5435 TREE_OPERAND (xarg0, 1),
5437 && tree_int_cst_sgn (c2) >= 0)
5438 /* The result is (C2%C3). */
5439 return omit_one_operand (type, const_binop (code, c2, arg1, 1),
5440 TREE_OPERAND (xarg0, 0));
5449 if (integer_zerop (arg1))
5450 return non_lvalue (convert (type, arg0));
5451 /* Since negative shift count is not well-defined,
5452 don't try to compute it in the compiler. */
5453 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
5455 /* Rewrite an LROTATE_EXPR by a constant into an
5456 RROTATE_EXPR by a new constant. */
5457 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
5459 TREE_SET_CODE (t, RROTATE_EXPR);
5460 code = RROTATE_EXPR;
5461 TREE_OPERAND (t, 1) = arg1
5464 convert (TREE_TYPE (arg1),
5465 build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type)), 0)),
5467 if (tree_int_cst_sgn (arg1) < 0)
5471 /* If we have a rotate of a bit operation with the rotate count and
5472 the second operand of the bit operation both constant,
5473 permute the two operations. */
5474 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
5475 && (TREE_CODE (arg0) == BIT_AND_EXPR
5476 || TREE_CODE (arg0) == BIT_ANDTC_EXPR
5477 || TREE_CODE (arg0) == BIT_IOR_EXPR
5478 || TREE_CODE (arg0) == BIT_XOR_EXPR)
5479 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
5480 return fold (build (TREE_CODE (arg0), type,
5481 fold (build (code, type,
5482 TREE_OPERAND (arg0, 0), arg1)),
5483 fold (build (code, type,
5484 TREE_OPERAND (arg0, 1), arg1))));
5486 /* Two consecutive rotates adding up to the width of the mode can
5488 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
5489 && TREE_CODE (arg0) == RROTATE_EXPR
5490 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5491 && TREE_INT_CST_HIGH (arg1) == 0
5492 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
5493 && ((TREE_INT_CST_LOW (arg1)
5494 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
5495 == GET_MODE_BITSIZE (TYPE_MODE (type))))
5496 return TREE_OPERAND (arg0, 0);
5501 if (operand_equal_p (arg0, arg1, 0))
5503 if (INTEGRAL_TYPE_P (type)
5504 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), 1))
5505 return omit_one_operand (type, arg1, arg0);
5509 if (operand_equal_p (arg0, arg1, 0))
5511 if (INTEGRAL_TYPE_P (type)
5512 && TYPE_MAX_VALUE (type)
5513 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), 1))
5514 return omit_one_operand (type, arg1, arg0);
5517 case TRUTH_NOT_EXPR:
5518 /* Note that the operand of this must be an int
5519 and its values must be 0 or 1.
5520 ("true" is a fixed value perhaps depending on the language,
5521 but we don't handle values other than 1 correctly yet.) */
5522 tem = invert_truthvalue (arg0);
5523 /* Avoid infinite recursion. */
5524 if (TREE_CODE (tem) == TRUTH_NOT_EXPR)
5526 return convert (type, tem);
5528 case TRUTH_ANDIF_EXPR:
5529 /* Note that the operands of this must be ints
5530 and their values must be 0 or 1.
5531 ("true" is a fixed value perhaps depending on the language.) */
5532 /* If first arg is constant zero, return it. */
5533 if (integer_zerop (arg0))
5535 case TRUTH_AND_EXPR:
5536 /* If either arg is constant true, drop it. */
5537 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
5538 return non_lvalue (arg1);
5539 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
5540 return non_lvalue (arg0);
5541 /* If second arg is constant zero, result is zero, but first arg
5542 must be evaluated. */
5543 if (integer_zerop (arg1))
5544 return omit_one_operand (type, arg1, arg0);
5545 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
5546 case will be handled here. */
5547 if (integer_zerop (arg0))
5548 return omit_one_operand (type, arg0, arg1);
5551 /* We only do these simplifications if we are optimizing. */
5555 /* Check for things like (A || B) && (A || C). We can convert this
5556 to A || (B && C). Note that either operator can be any of the four
5557 truth and/or operations and the transformation will still be
5558 valid. Also note that we only care about order for the
5559 ANDIF and ORIF operators. If B contains side effects, this
5560 might change the truth-value of A. */
5561 if (TREE_CODE (arg0) == TREE_CODE (arg1)
5562 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
5563 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
5564 || TREE_CODE (arg0) == TRUTH_AND_EXPR
5565 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
5566 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
5568 tree a00 = TREE_OPERAND (arg0, 0);
5569 tree a01 = TREE_OPERAND (arg0, 1);
5570 tree a10 = TREE_OPERAND (arg1, 0);
5571 tree a11 = TREE_OPERAND (arg1, 1);
5572 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
5573 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
5574 && (code == TRUTH_AND_EXPR
5575 || code == TRUTH_OR_EXPR));
5577 if (operand_equal_p (a00, a10, 0))
5578 return fold (build (TREE_CODE (arg0), type, a00,
5579 fold (build (code, type, a01, a11))));
5580 else if (commutative && operand_equal_p (a00, a11, 0))
5581 return fold (build (TREE_CODE (arg0), type, a00,
5582 fold (build (code, type, a01, a10))));
5583 else if (commutative && operand_equal_p (a01, a10, 0))
5584 return fold (build (TREE_CODE (arg0), type, a01,
5585 fold (build (code, type, a00, a11))));
5587 /* This case if tricky because we must either have commutative
5588 operators or else A10 must not have side-effects. */
5590 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
5591 && operand_equal_p (a01, a11, 0))
5592 return fold (build (TREE_CODE (arg0), type,
5593 fold (build (code, type, a00, a10)),
5597 /* See if we can build a range comparison. */
5598 if (0 != (tem = fold_range_test (t)))
5601 /* Check for the possibility of merging component references. If our
5602 lhs is another similar operation, try to merge its rhs with our
5603 rhs. Then try to merge our lhs and rhs. */
5604 if (TREE_CODE (arg0) == code
5605 && 0 != (tem = fold_truthop (code, type,
5606 TREE_OPERAND (arg0, 1), arg1)))
5607 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
5609 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
5614 case TRUTH_ORIF_EXPR:
5615 /* Note that the operands of this must be ints
5616 and their values must be 0 or true.
5617 ("true" is a fixed value perhaps depending on the language.) */
5618 /* If first arg is constant true, return it. */
5619 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
5622 /* If either arg is constant zero, drop it. */
5623 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
5624 return non_lvalue (arg1);
5625 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1))
5626 return non_lvalue (arg0);
5627 /* If second arg is constant true, result is true, but we must
5628 evaluate first arg. */
5629 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
5630 return omit_one_operand (type, arg1, arg0);
5631 /* Likewise for first arg, but note this only occurs here for
5633 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
5634 return omit_one_operand (type, arg0, arg1);
5637 case TRUTH_XOR_EXPR:
5638 /* If either arg is constant zero, drop it. */
5639 if (integer_zerop (arg0))
5640 return non_lvalue (arg1);
5641 if (integer_zerop (arg1))
5642 return non_lvalue (arg0);
5643 /* If either arg is constant true, this is a logical inversion. */
5644 if (integer_onep (arg0))
5645 return non_lvalue (invert_truthvalue (arg1));
5646 if (integer_onep (arg1))
5647 return non_lvalue (invert_truthvalue (arg0));
5656 /* If one arg is a constant integer, put it last. */
5657 if (TREE_CODE (arg0) == INTEGER_CST
5658 && TREE_CODE (arg1) != INTEGER_CST)
5660 TREE_OPERAND (t, 0) = arg1;
5661 TREE_OPERAND (t, 1) = arg0;
5662 arg0 = TREE_OPERAND (t, 0);
5663 arg1 = TREE_OPERAND (t, 1);
5664 code = swap_tree_comparison (code);
5665 TREE_SET_CODE (t, code);
5668 /* Convert foo++ == CONST into ++foo == CONST + INCR.
5669 First, see if one arg is constant; find the constant arg
5670 and the other one. */
5672 tree constop = 0, varop = NULL_TREE;
5673 int constopnum = -1;
5675 if (TREE_CONSTANT (arg1))
5676 constopnum = 1, constop = arg1, varop = arg0;
5677 if (TREE_CONSTANT (arg0))
5678 constopnum = 0, constop = arg0, varop = arg1;
5680 if (constop && TREE_CODE (varop) == POSTINCREMENT_EXPR)
5682 /* This optimization is invalid for ordered comparisons
5683 if CONST+INCR overflows or if foo+incr might overflow.
5684 This optimization is invalid for floating point due to rounding.
5685 For pointer types we assume overflow doesn't happen. */
5686 if (POINTER_TYPE_P (TREE_TYPE (varop))
5687 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
5688 && (code == EQ_EXPR || code == NE_EXPR)))
5691 = fold (build (PLUS_EXPR, TREE_TYPE (varop),
5692 constop, TREE_OPERAND (varop, 1)));
5693 TREE_SET_CODE (varop, PREINCREMENT_EXPR);
5695 /* If VAROP is a reference to a bitfield, we must mask
5696 the constant by the width of the field. */
5697 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
5698 && DECL_BIT_FIELD(TREE_OPERAND
5699 (TREE_OPERAND (varop, 0), 1)))
5702 = TREE_INT_CST_LOW (DECL_SIZE
5704 (TREE_OPERAND (varop, 0), 1)));
5705 tree mask, unsigned_type;
5707 tree folded_compare;
5709 /* First check whether the comparison would come out
5710 always the same. If we don't do that we would
5711 change the meaning with the masking. */
5712 if (constopnum == 0)
5713 folded_compare = fold (build (code, type, constop,
5714 TREE_OPERAND (varop, 0)));
5716 folded_compare = fold (build (code, type,
5717 TREE_OPERAND (varop, 0),
5719 if (integer_zerop (folded_compare)
5720 || integer_onep (folded_compare))
5721 return omit_one_operand (type, folded_compare, varop);
5723 unsigned_type = type_for_size (size, 1);
5724 precision = TYPE_PRECISION (unsigned_type);
5725 mask = build_int_2 (~0, ~0);
5726 TREE_TYPE (mask) = unsigned_type;
5727 force_fit_type (mask, 0);
5728 mask = const_binop (RSHIFT_EXPR, mask,
5729 size_int (precision - size), 0);
5730 newconst = fold (build (BIT_AND_EXPR,
5731 TREE_TYPE (varop), newconst,
5732 convert (TREE_TYPE (varop),
5737 t = build (code, type, TREE_OPERAND (t, 0),
5738 TREE_OPERAND (t, 1));
5739 TREE_OPERAND (t, constopnum) = newconst;
5743 else if (constop && TREE_CODE (varop) == POSTDECREMENT_EXPR)
5745 if (POINTER_TYPE_P (TREE_TYPE (varop))
5746 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
5747 && (code == EQ_EXPR || code == NE_EXPR)))
5750 = fold (build (MINUS_EXPR, TREE_TYPE (varop),
5751 constop, TREE_OPERAND (varop, 1)));
5752 TREE_SET_CODE (varop, PREDECREMENT_EXPR);
5754 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
5755 && DECL_BIT_FIELD(TREE_OPERAND
5756 (TREE_OPERAND (varop, 0), 1)))
5759 = TREE_INT_CST_LOW (DECL_SIZE
5761 (TREE_OPERAND (varop, 0), 1)));
5762 tree mask, unsigned_type;
5764 tree folded_compare;
5766 if (constopnum == 0)
5767 folded_compare = fold (build (code, type, constop,
5768 TREE_OPERAND (varop, 0)));
5770 folded_compare = fold (build (code, type,
5771 TREE_OPERAND (varop, 0),
5773 if (integer_zerop (folded_compare)
5774 || integer_onep (folded_compare))
5775 return omit_one_operand (type, folded_compare, varop);
5777 unsigned_type = type_for_size (size, 1);
5778 precision = TYPE_PRECISION (unsigned_type);
5779 mask = build_int_2 (~0, ~0);
5780 TREE_TYPE (mask) = TREE_TYPE (varop);
5781 force_fit_type (mask, 0);
5782 mask = const_binop (RSHIFT_EXPR, mask,
5783 size_int (precision - size), 0);
5784 newconst = fold (build (BIT_AND_EXPR,
5785 TREE_TYPE (varop), newconst,
5786 convert (TREE_TYPE (varop),
5791 t = build (code, type, TREE_OPERAND (t, 0),
5792 TREE_OPERAND (t, 1));
5793 TREE_OPERAND (t, constopnum) = newconst;
5799 /* Change X >= CST to X > (CST - 1) if CST is positive. */
5800 if (TREE_CODE (arg1) == INTEGER_CST
5801 && TREE_CODE (arg0) != INTEGER_CST
5802 && tree_int_cst_sgn (arg1) > 0)
5804 switch (TREE_CODE (t))
5808 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
5809 t = build (code, type, TREE_OPERAND (t, 0), arg1);
5814 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
5815 t = build (code, type, TREE_OPERAND (t, 0), arg1);
5823 /* If this is an EQ or NE comparison with zero and ARG0 is
5824 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
5825 two operations, but the latter can be done in one less insn
5826 on machines that have only two-operand insns or on which a
5827 constant cannot be the first operand. */
5828 if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR)
5829 && TREE_CODE (arg0) == BIT_AND_EXPR)
5831 if (TREE_CODE (TREE_OPERAND (arg0, 0)) == LSHIFT_EXPR
5832 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 0), 0)))
5834 fold (build (code, type,
5835 build (BIT_AND_EXPR, TREE_TYPE (arg0),
5837 TREE_TYPE (TREE_OPERAND (arg0, 0)),
5838 TREE_OPERAND (arg0, 1),
5839 TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)),
5840 convert (TREE_TYPE (arg0),
5843 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
5844 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
5846 fold (build (code, type,
5847 build (BIT_AND_EXPR, TREE_TYPE (arg0),
5849 TREE_TYPE (TREE_OPERAND (arg0, 1)),
5850 TREE_OPERAND (arg0, 0),
5851 TREE_OPERAND (TREE_OPERAND (arg0, 1), 1)),
5852 convert (TREE_TYPE (arg0),
5857 /* If this is an NE or EQ comparison of zero against the result of a
5858 signed MOD operation whose second operand is a power of 2, make
5859 the MOD operation unsigned since it is simpler and equivalent. */
5860 if ((code == NE_EXPR || code == EQ_EXPR)
5861 && integer_zerop (arg1)
5862 && ! TREE_UNSIGNED (TREE_TYPE (arg0))
5863 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
5864 || TREE_CODE (arg0) == CEIL_MOD_EXPR
5865 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
5866 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
5867 && integer_pow2p (TREE_OPERAND (arg0, 1)))
5869 tree newtype = unsigned_type (TREE_TYPE (arg0));
5870 tree newmod = build (TREE_CODE (arg0), newtype,
5871 convert (newtype, TREE_OPERAND (arg0, 0)),
5872 convert (newtype, TREE_OPERAND (arg0, 1)));
5874 return build (code, type, newmod, convert (newtype, arg1));
5877 /* If this is an NE comparison of zero with an AND of one, remove the
5878 comparison since the AND will give the correct value. */
5879 if (code == NE_EXPR && integer_zerop (arg1)
5880 && TREE_CODE (arg0) == BIT_AND_EXPR
5881 && integer_onep (TREE_OPERAND (arg0, 1)))
5882 return convert (type, arg0);
5884 /* If we have (A & C) == C where C is a power of 2, convert this into
5885 (A & C) != 0. Similarly for NE_EXPR. */
5886 if ((code == EQ_EXPR || code == NE_EXPR)
5887 && TREE_CODE (arg0) == BIT_AND_EXPR
5888 && integer_pow2p (TREE_OPERAND (arg0, 1))
5889 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
5890 return build (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
5891 arg0, integer_zero_node);
5893 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
5894 and similarly for >= into !=. */
5895 if ((code == LT_EXPR || code == GE_EXPR)
5896 && TREE_UNSIGNED (TREE_TYPE (arg0))
5897 && TREE_CODE (arg1) == LSHIFT_EXPR
5898 && integer_onep (TREE_OPERAND (arg1, 0)))
5899 return build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
5900 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
5901 TREE_OPERAND (arg1, 1)),
5902 convert (TREE_TYPE (arg0), integer_zero_node));
5904 else if ((code == LT_EXPR || code == GE_EXPR)
5905 && TREE_UNSIGNED (TREE_TYPE (arg0))
5906 && (TREE_CODE (arg1) == NOP_EXPR
5907 || TREE_CODE (arg1) == CONVERT_EXPR)
5908 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
5909 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
5911 build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
5912 convert (TREE_TYPE (arg0),
5913 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
5914 TREE_OPERAND (TREE_OPERAND (arg1, 0), 1))),
5915 convert (TREE_TYPE (arg0), integer_zero_node));
5917 /* Simplify comparison of something with itself. (For IEEE
5918 floating-point, we can only do some of these simplifications.) */
5919 if (operand_equal_p (arg0, arg1, 0))
5926 if (INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
5927 return constant_boolean_node (1, type);
5929 TREE_SET_CODE (t, code);
5933 /* For NE, we can only do this simplification if integer. */
5934 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
5936 /* ... fall through ... */
5939 return constant_boolean_node (0, type);
5945 /* An unsigned comparison against 0 can be simplified. */
5946 if (integer_zerop (arg1)
5947 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
5948 || POINTER_TYPE_P (TREE_TYPE (arg1)))
5949 && TREE_UNSIGNED (TREE_TYPE (arg1)))
5951 switch (TREE_CODE (t))
5955 TREE_SET_CODE (t, NE_EXPR);
5959 TREE_SET_CODE (t, EQ_EXPR);
5962 return omit_one_operand (type,
5963 convert (type, integer_one_node),
5966 return omit_one_operand (type,
5967 convert (type, integer_zero_node),
5974 /* An unsigned <= 0x7fffffff can be simplified. */
5976 int width = TYPE_PRECISION (TREE_TYPE (arg1));
5977 if (TREE_CODE (arg1) == INTEGER_CST
5978 && ! TREE_CONSTANT_OVERFLOW (arg1)
5979 && width <= HOST_BITS_PER_WIDE_INT
5980 && TREE_INT_CST_LOW (arg1) == ((HOST_WIDE_INT) 1 << (width - 1)) - 1
5981 && TREE_INT_CST_HIGH (arg1) == 0
5982 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
5983 || POINTER_TYPE_P (TREE_TYPE (arg1)))
5984 && TREE_UNSIGNED (TREE_TYPE (arg1)))
5986 switch (TREE_CODE (t))
5989 return fold (build (GE_EXPR, type,
5990 convert (signed_type (TREE_TYPE (arg0)),
5992 convert (signed_type (TREE_TYPE (arg1)),
5993 integer_zero_node)));
5995 return fold (build (LT_EXPR, type,
5996 convert (signed_type (TREE_TYPE (arg0)),
5998 convert (signed_type (TREE_TYPE (arg1)),
5999 integer_zero_node)));
6006 /* If we are comparing an expression that just has comparisons
6007 of two integer values, arithmetic expressions of those comparisons,
6008 and constants, we can simplify it. There are only three cases
6009 to check: the two values can either be equal, the first can be
6010 greater, or the second can be greater. Fold the expression for
6011 those three values. Since each value must be 0 or 1, we have
6012 eight possibilities, each of which corresponds to the constant 0
6013 or 1 or one of the six possible comparisons.
6015 This handles common cases like (a > b) == 0 but also handles
6016 expressions like ((x > y) - (y > x)) > 0, which supposedly
6017 occur in macroized code. */
6019 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
6021 tree cval1 = 0, cval2 = 0;
6024 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
6025 /* Don't handle degenerate cases here; they should already
6026 have been handled anyway. */
6027 && cval1 != 0 && cval2 != 0
6028 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
6029 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
6030 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
6031 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
6032 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
6033 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
6034 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
6036 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
6037 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
6039 /* We can't just pass T to eval_subst in case cval1 or cval2
6040 was the same as ARG1. */
6043 = fold (build (code, type,
6044 eval_subst (arg0, cval1, maxval, cval2, minval),
6047 = fold (build (code, type,
6048 eval_subst (arg0, cval1, maxval, cval2, maxval),
6051 = fold (build (code, type,
6052 eval_subst (arg0, cval1, minval, cval2, maxval),
6055 /* All three of these results should be 0 or 1. Confirm they
6056 are. Then use those values to select the proper code
6059 if ((integer_zerop (high_result)
6060 || integer_onep (high_result))
6061 && (integer_zerop (equal_result)
6062 || integer_onep (equal_result))
6063 && (integer_zerop (low_result)
6064 || integer_onep (low_result)))
6066 /* Make a 3-bit mask with the high-order bit being the
6067 value for `>', the next for '=', and the low for '<'. */
6068 switch ((integer_onep (high_result) * 4)
6069 + (integer_onep (equal_result) * 2)
6070 + integer_onep (low_result))
6074 return omit_one_operand (type, integer_zero_node, arg0);
6095 return omit_one_operand (type, integer_one_node, arg0);
6098 t = build (code, type, cval1, cval2);
6100 return save_expr (t);
6107 /* If this is a comparison of a field, we may be able to simplify it. */
6108 if ((TREE_CODE (arg0) == COMPONENT_REF
6109 || TREE_CODE (arg0) == BIT_FIELD_REF)
6110 && (code == EQ_EXPR || code == NE_EXPR)
6111 /* Handle the constant case even without -O
6112 to make sure the warnings are given. */
6113 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
6115 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
6119 /* If this is a comparison of complex values and either or both sides
6120 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
6121 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
6122 This may prevent needless evaluations. */
6123 if ((code == EQ_EXPR || code == NE_EXPR)
6124 && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
6125 && (TREE_CODE (arg0) == COMPLEX_EXPR
6126 || TREE_CODE (arg1) == COMPLEX_EXPR
6127 || TREE_CODE (arg0) == COMPLEX_CST
6128 || TREE_CODE (arg1) == COMPLEX_CST))
6130 tree subtype = TREE_TYPE (TREE_TYPE (arg0));
6131 tree real0, imag0, real1, imag1;
6133 arg0 = save_expr (arg0);
6134 arg1 = save_expr (arg1);
6135 real0 = fold (build1 (REALPART_EXPR, subtype, arg0));
6136 imag0 = fold (build1 (IMAGPART_EXPR, subtype, arg0));
6137 real1 = fold (build1 (REALPART_EXPR, subtype, arg1));
6138 imag1 = fold (build1 (IMAGPART_EXPR, subtype, arg1));
6140 return fold (build ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR
6143 fold (build (code, type, real0, real1)),
6144 fold (build (code, type, imag0, imag1))));
6147 /* From here on, the only cases we handle are when the result is
6148 known to be a constant.
6150 To compute GT, swap the arguments and do LT.
6151 To compute GE, do LT and invert the result.
6152 To compute LE, swap the arguments, do LT and invert the result.
6153 To compute NE, do EQ and invert the result.
6155 Therefore, the code below must handle only EQ and LT. */
6157 if (code == LE_EXPR || code == GT_EXPR)
6159 tem = arg0, arg0 = arg1, arg1 = tem;
6160 code = swap_tree_comparison (code);
6163 /* Note that it is safe to invert for real values here because we
6164 will check below in the one case that it matters. */
6167 if (code == NE_EXPR || code == GE_EXPR)
6170 code = invert_tree_comparison (code);
6173 /* Compute a result for LT or EQ if args permit;
6174 otherwise return T. */
6175 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
6177 if (code == EQ_EXPR)
6178 t1 = build_int_2 ((TREE_INT_CST_LOW (arg0)
6179 == TREE_INT_CST_LOW (arg1))
6180 && (TREE_INT_CST_HIGH (arg0)
6181 == TREE_INT_CST_HIGH (arg1)),
6184 t1 = build_int_2 ((TREE_UNSIGNED (TREE_TYPE (arg0))
6185 ? INT_CST_LT_UNSIGNED (arg0, arg1)
6186 : INT_CST_LT (arg0, arg1)),
6190 #if 0 /* This is no longer useful, but breaks some real code. */
6191 /* Assume a nonexplicit constant cannot equal an explicit one,
6192 since such code would be undefined anyway.
6193 Exception: on sysvr4, using #pragma weak,
6194 a label can come out as 0. */
6195 else if (TREE_CODE (arg1) == INTEGER_CST
6196 && !integer_zerop (arg1)
6197 && TREE_CONSTANT (arg0)
6198 && TREE_CODE (arg0) == ADDR_EXPR
6200 t1 = build_int_2 (0, 0);
6202 /* Two real constants can be compared explicitly. */
6203 else if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
6205 /* If either operand is a NaN, the result is false with two
6206 exceptions: First, an NE_EXPR is true on NaNs, but that case
6207 is already handled correctly since we will be inverting the
6208 result for NE_EXPR. Second, if we had inverted a LE_EXPR
6209 or a GE_EXPR into a LT_EXPR, we must return true so that it
6210 will be inverted into false. */
6212 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
6213 || REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
6214 t1 = build_int_2 (invert && code == LT_EXPR, 0);
6216 else if (code == EQ_EXPR)
6217 t1 = build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (arg0),
6218 TREE_REAL_CST (arg1)),
6221 t1 = build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (arg0),
6222 TREE_REAL_CST (arg1)),
6226 if (t1 == NULL_TREE)
6230 TREE_INT_CST_LOW (t1) ^= 1;
6232 TREE_TYPE (t1) = type;
6233 if (TREE_CODE (type) == BOOLEAN_TYPE)
6234 return truthvalue_conversion (t1);
6238 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
6239 so all simple results must be passed through pedantic_non_lvalue. */
6240 if (TREE_CODE (arg0) == INTEGER_CST)
6241 return pedantic_non_lvalue
6242 (TREE_OPERAND (t, (integer_zerop (arg0) ? 2 : 1)));
6243 else if (operand_equal_p (arg1, TREE_OPERAND (expr, 2), 0))
6244 return pedantic_omit_one_operand (type, arg1, arg0);
6246 /* If the second operand is zero, invert the comparison and swap
6247 the second and third operands. Likewise if the second operand
6248 is constant and the third is not or if the third operand is
6249 equivalent to the first operand of the comparison. */
6251 if (integer_zerop (arg1)
6252 || (TREE_CONSTANT (arg1) && ! TREE_CONSTANT (TREE_OPERAND (t, 2)))
6253 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
6254 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
6255 TREE_OPERAND (t, 2),
6256 TREE_OPERAND (arg0, 1))))
6258 /* See if this can be inverted. If it can't, possibly because
6259 it was a floating-point inequality comparison, don't do
6261 tem = invert_truthvalue (arg0);
6263 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
6265 t = build (code, type, tem,
6266 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
6268 /* arg1 should be the first argument of the new T. */
6269 arg1 = TREE_OPERAND (t, 1);
6274 /* If we have A op B ? A : C, we may be able to convert this to a
6275 simpler expression, depending on the operation and the values
6276 of B and C. IEEE floating point prevents this though,
6277 because A or B might be -0.0 or a NaN. */
6279 if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
6280 && (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
6281 || ! FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 0)))
6283 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
6284 arg1, TREE_OPERAND (arg0, 1)))
6286 tree arg2 = TREE_OPERAND (t, 2);
6287 enum tree_code comp_code = TREE_CODE (arg0);
6291 /* If we have A op 0 ? A : -A, this is A, -A, abs (A), or abs (-A),
6292 depending on the comparison operation. */
6293 if ((FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 1)))
6294 ? real_zerop (TREE_OPERAND (arg0, 1))
6295 : integer_zerop (TREE_OPERAND (arg0, 1)))
6296 && TREE_CODE (arg2) == NEGATE_EXPR
6297 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
6301 return pedantic_non_lvalue
6302 (fold (build1 (NEGATE_EXPR, type, arg1)));
6304 return pedantic_non_lvalue (convert (type, arg1));
6307 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
6308 arg1 = convert (signed_type (TREE_TYPE (arg1)), arg1);
6309 return pedantic_non_lvalue
6310 (convert (type, fold (build1 (ABS_EXPR,
6311 TREE_TYPE (arg1), arg1))));
6314 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
6315 arg1 = convert (signed_type (TREE_TYPE (arg1)), arg1);
6316 return pedantic_non_lvalue
6317 (fold (build1 (NEGATE_EXPR, type,
6319 fold (build1 (ABS_EXPR,
6326 /* If this is A != 0 ? A : 0, this is simply A. For ==, it is
6329 if (integer_zerop (TREE_OPERAND (arg0, 1)) && integer_zerop (arg2))
6331 if (comp_code == NE_EXPR)
6332 return pedantic_non_lvalue (convert (type, arg1));
6333 else if (comp_code == EQ_EXPR)
6334 return pedantic_non_lvalue (convert (type, integer_zero_node));
6337 /* If this is A op B ? A : B, this is either A, B, min (A, B),
6338 or max (A, B), depending on the operation. */
6340 if (operand_equal_for_comparison_p (TREE_OPERAND (arg0, 1),
6341 arg2, TREE_OPERAND (arg0, 0)))
6343 tree comp_op0 = TREE_OPERAND (arg0, 0);
6344 tree comp_op1 = TREE_OPERAND (arg0, 1);
6345 tree comp_type = TREE_TYPE (comp_op0);
6350 return pedantic_non_lvalue (convert (type, arg2));
6352 return pedantic_non_lvalue (convert (type, arg1));
6355 /* In C++ a ?: expression can be an lvalue, so put the
6356 operand which will be used if they are equal first
6357 so that we can convert this back to the
6358 corresponding COND_EXPR. */
6359 return pedantic_non_lvalue
6360 (convert (type, (fold (build (MIN_EXPR, comp_type,
6361 (comp_code == LE_EXPR
6362 ? comp_op0 : comp_op1),
6363 (comp_code == LE_EXPR
6364 ? comp_op1 : comp_op0))))));
6368 return pedantic_non_lvalue
6369 (convert (type, fold (build (MAX_EXPR, comp_type,
6370 (comp_code == GE_EXPR
6371 ? comp_op0 : comp_op1),
6372 (comp_code == GE_EXPR
6373 ? comp_op1 : comp_op0)))));
6380 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
6381 we might still be able to simplify this. For example,
6382 if C1 is one less or one more than C2, this might have started
6383 out as a MIN or MAX and been transformed by this function.
6384 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
6386 if (INTEGRAL_TYPE_P (type)
6387 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6388 && TREE_CODE (arg2) == INTEGER_CST)
6392 /* We can replace A with C1 in this case. */
6393 arg1 = convert (type, TREE_OPERAND (arg0, 1));
6394 t = build (code, type, TREE_OPERAND (t, 0), arg1,
6395 TREE_OPERAND (t, 2));
6399 /* If C1 is C2 + 1, this is min(A, C2). */
6400 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
6401 && operand_equal_p (TREE_OPERAND (arg0, 1),
6402 const_binop (PLUS_EXPR, arg2,
6403 integer_one_node, 0), 1))
6404 return pedantic_non_lvalue
6405 (fold (build (MIN_EXPR, type, arg1, arg2)));
6409 /* If C1 is C2 - 1, this is min(A, C2). */
6410 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
6411 && operand_equal_p (TREE_OPERAND (arg0, 1),
6412 const_binop (MINUS_EXPR, arg2,
6413 integer_one_node, 0), 1))
6414 return pedantic_non_lvalue
6415 (fold (build (MIN_EXPR, type, arg1, arg2)));
6419 /* If C1 is C2 - 1, this is max(A, C2). */
6420 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
6421 && operand_equal_p (TREE_OPERAND (arg0, 1),
6422 const_binop (MINUS_EXPR, arg2,
6423 integer_one_node, 0), 1))
6424 return pedantic_non_lvalue
6425 (fold (build (MAX_EXPR, type, arg1, arg2)));
6429 /* If C1 is C2 + 1, this is max(A, C2). */
6430 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
6431 && operand_equal_p (TREE_OPERAND (arg0, 1),
6432 const_binop (PLUS_EXPR, arg2,
6433 integer_one_node, 0), 1))
6434 return pedantic_non_lvalue
6435 (fold (build (MAX_EXPR, type, arg1, arg2)));
6444 /* If the second operand is simpler than the third, swap them
6445 since that produces better jump optimization results. */
6446 if ((TREE_CONSTANT (arg1) || TREE_CODE_CLASS (TREE_CODE (arg1)) == 'd'
6447 || TREE_CODE (arg1) == SAVE_EXPR)
6448 && ! (TREE_CONSTANT (TREE_OPERAND (t, 2))
6449 || TREE_CODE_CLASS (TREE_CODE (TREE_OPERAND (t, 2))) == 'd'
6450 || TREE_CODE (TREE_OPERAND (t, 2)) == SAVE_EXPR))
6452 /* See if this can be inverted. If it can't, possibly because
6453 it was a floating-point inequality comparison, don't do
6455 tem = invert_truthvalue (arg0);
6457 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
6459 t = build (code, type, tem,
6460 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
6462 /* arg1 should be the first argument of the new T. */
6463 arg1 = TREE_OPERAND (t, 1);
6468 /* Convert A ? 1 : 0 to simply A. */
6469 if (integer_onep (TREE_OPERAND (t, 1))
6470 && integer_zerop (TREE_OPERAND (t, 2))
6471 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
6472 call to fold will try to move the conversion inside
6473 a COND, which will recurse. In that case, the COND_EXPR
6474 is probably the best choice, so leave it alone. */
6475 && type == TREE_TYPE (arg0))
6476 return pedantic_non_lvalue (arg0);
6478 /* Look for expressions of the form A & 2 ? 2 : 0. The result of this
6479 operation is simply A & 2. */
6481 if (integer_zerop (TREE_OPERAND (t, 2))
6482 && TREE_CODE (arg0) == NE_EXPR
6483 && integer_zerop (TREE_OPERAND (arg0, 1))
6484 && integer_pow2p (arg1)
6485 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
6486 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
6488 return pedantic_non_lvalue (convert (type, TREE_OPERAND (arg0, 0)));
6493 /* When pedantic, a compound expression can be neither an lvalue
6494 nor an integer constant expression. */
6495 if (TREE_SIDE_EFFECTS (arg0) || pedantic)
6497 /* Don't let (0, 0) be null pointer constant. */
6498 if (integer_zerop (arg1))
6499 return build1 (NOP_EXPR, TREE_TYPE (arg1), arg1);
6504 return build_complex (type, arg0, arg1);
6508 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
6510 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
6511 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
6512 TREE_OPERAND (arg0, 1));
6513 else if (TREE_CODE (arg0) == COMPLEX_CST)
6514 return TREE_REALPART (arg0);
6515 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
6516 return fold (build (TREE_CODE (arg0), type,
6517 fold (build1 (REALPART_EXPR, type,
6518 TREE_OPERAND (arg0, 0))),
6519 fold (build1 (REALPART_EXPR,
6520 type, TREE_OPERAND (arg0, 1)))));
6524 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
6525 return convert (type, integer_zero_node);
6526 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
6527 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
6528 TREE_OPERAND (arg0, 0));
6529 else if (TREE_CODE (arg0) == COMPLEX_CST)
6530 return TREE_IMAGPART (arg0);
6531 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
6532 return fold (build (TREE_CODE (arg0), type,
6533 fold (build1 (IMAGPART_EXPR, type,
6534 TREE_OPERAND (arg0, 0))),
6535 fold (build1 (IMAGPART_EXPR, type,
6536 TREE_OPERAND (arg0, 1)))));
6539 /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
6541 case CLEANUP_POINT_EXPR:
6542 if (! has_cleanups (arg0))
6543 return TREE_OPERAND (t, 0);
6546 enum tree_code code0 = TREE_CODE (arg0);
6547 int kind0 = TREE_CODE_CLASS (code0);
6548 tree arg00 = TREE_OPERAND (arg0, 0);
6551 if (kind0 == '1' || code0 == TRUTH_NOT_EXPR)
6552 return fold (build1 (code0, type,
6553 fold (build1 (CLEANUP_POINT_EXPR,
6554 TREE_TYPE (arg00), arg00))));
6556 if (kind0 == '<' || kind0 == '2'
6557 || code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR
6558 || code0 == TRUTH_AND_EXPR || code0 == TRUTH_OR_EXPR
6559 || code0 == TRUTH_XOR_EXPR)
6561 arg01 = TREE_OPERAND (arg0, 1);
6563 if (TREE_CONSTANT (arg00)
6564 || ((code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR)
6565 && ! has_cleanups (arg00)))
6566 return fold (build (code0, type, arg00,
6567 fold (build1 (CLEANUP_POINT_EXPR,
6568 TREE_TYPE (arg01), arg01))));
6570 if (TREE_CONSTANT (arg01))
6571 return fold (build (code0, type,
6572 fold (build1 (CLEANUP_POINT_EXPR,
6573 TREE_TYPE (arg00), arg00)),
6582 } /* switch (code) */
6585 /* Determine if first argument is a multiple of second argument. Return 0 if
6586 it is not, or we cannot easily determined it to be.
6588 An example of the sort of thing we care about (at this point; this routine
6589 could surely be made more general, and expanded to do what the *_DIV_EXPR's
6590 fold cases do now) is discovering that
6592 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
6598 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
6600 This code also handles discovering that
6602 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
6604 is a multiple of 8 so we don't have to worry about dealing with a
6607 Note that we *look* inside a SAVE_EXPR only to determine how it was
6608 calculated; it is not safe for fold to do much of anything else with the
6609 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
6610 at run time. For example, the latter example above *cannot* be implemented
6611 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
6612 evaluation time of the original SAVE_EXPR is not necessarily the same at
6613 the time the new expression is evaluated. The only optimization of this
6614 sort that would be valid is changing
6616 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
6620 SAVE_EXPR (I) * SAVE_EXPR (J)
6622 (where the same SAVE_EXPR (J) is used in the original and the
6623 transformed version). */
6626 multiple_of_p (type, top, bottom)
6631 if (operand_equal_p (top, bottom, 0))
6634 if (TREE_CODE (type) != INTEGER_TYPE)
6637 switch (TREE_CODE (top))
6640 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
6641 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
6645 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
6646 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
6649 /* Can't handle conversions from non-integral or wider integral type. */
6650 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
6651 || (TYPE_PRECISION (type)
6652 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
6655 /* .. fall through ... */
6658 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
6661 if ((TREE_CODE (bottom) != INTEGER_CST)
6662 || (tree_int_cst_sgn (top) < 0)
6663 || (tree_int_cst_sgn (bottom) < 0))
6665 return integer_zerop (const_binop (TRUNC_MOD_EXPR,