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. */
53 static void encode PROTO((HOST_WIDE_INT *,
54 HOST_WIDE_INT, HOST_WIDE_INT));
55 static void decode PROTO((HOST_WIDE_INT *,
56 HOST_WIDE_INT *, HOST_WIDE_INT *));
57 int div_and_round_double PROTO((enum tree_code, int, HOST_WIDE_INT,
58 HOST_WIDE_INT, HOST_WIDE_INT,
59 HOST_WIDE_INT, HOST_WIDE_INT *,
60 HOST_WIDE_INT *, HOST_WIDE_INT *,
62 static int split_tree PROTO((tree, enum tree_code, tree *,
64 static tree int_const_binop PROTO((enum tree_code, tree, tree, int, int));
65 static tree const_binop PROTO((enum tree_code, tree, tree, int));
66 static tree fold_convert PROTO((tree, tree));
67 static enum tree_code invert_tree_comparison PROTO((enum tree_code));
68 static enum tree_code swap_tree_comparison PROTO((enum tree_code));
69 static int truth_value_p PROTO((enum tree_code));
70 static int operand_equal_for_comparison_p PROTO((tree, tree, tree));
71 static int twoval_comparison_p PROTO((tree, tree *, tree *, int *));
72 static tree eval_subst PROTO((tree, tree, tree, tree, tree));
73 static tree omit_one_operand PROTO((tree, tree, tree));
74 static tree pedantic_omit_one_operand PROTO((tree, tree, tree));
75 static tree distribute_bit_expr PROTO((enum tree_code, tree, tree, tree));
76 static tree make_bit_field_ref PROTO((tree, tree, int, int, int));
77 static tree optimize_bit_field_compare PROTO((enum tree_code, tree,
79 static tree decode_field_reference PROTO((tree, int *, int *,
80 enum machine_mode *, int *,
81 int *, tree *, tree *));
82 static int all_ones_mask_p PROTO((tree, int));
83 static int simple_operand_p PROTO((tree));
84 static tree range_binop PROTO((enum tree_code, tree, tree, int,
86 static tree make_range PROTO((tree, int *, tree *, tree *));
87 static tree build_range_check PROTO((tree, tree, int, tree, tree));
88 static int merge_ranges PROTO((int *, tree *, tree *, int, tree, tree,
90 static tree fold_range_test PROTO((tree));
91 static tree unextend PROTO((tree, int, int, tree));
92 static tree fold_truthop PROTO((enum tree_code, tree, tree, tree));
93 static tree strip_compound_expr PROTO((tree, tree));
94 static int multiple_of_p PROTO((tree, tree, tree));
95 static tree constant_boolean_node PROTO((int, tree));
96 static int count_cond PROTO((tree, int));
97 static void const_binop_1 PROTO((PTR));
98 static void fold_convert_1 PROTO((PTR));
101 #define BRANCH_COST 1
104 /* Suppose A1 + B1 = SUM1, using 2's complement arithmetic ignoring overflow.
105 Suppose A, B and SUM have the same respective signs as A1, B1, and SUM1.
106 Then this yields nonzero if overflow occurred during the addition.
107 Overflow occurs if A and B have the same sign, but A and SUM differ in sign.
108 Use `^' to test whether signs differ, and `< 0' to isolate the sign. */
109 #define overflow_sum_sign(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
111 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
112 We do that by representing the two-word integer in 4 words, with only
113 HOST_BITS_PER_WIDE_INT/2 bits stored in each word, as a positive number. */
116 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT/2)) - 1))
117 #define HIGHPART(x) \
118 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT/2)
119 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT/2)
121 /* Unpack a two-word integer into 4 words.
122 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
123 WORDS points to the array of HOST_WIDE_INTs. */
126 encode (words, low, hi)
127 HOST_WIDE_INT *words;
128 HOST_WIDE_INT low, hi;
130 words[0] = LOWPART (low);
131 words[1] = HIGHPART (low);
132 words[2] = LOWPART (hi);
133 words[3] = HIGHPART (hi);
136 /* Pack an array of 4 words into a two-word integer.
137 WORDS points to the array of words.
138 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
141 decode (words, low, hi)
142 HOST_WIDE_INT *words;
143 HOST_WIDE_INT *low, *hi;
145 *low = words[0] | words[1] * BASE;
146 *hi = words[2] | words[3] * BASE;
149 /* Make the integer constant T valid for its type
150 by setting to 0 or 1 all the bits in the constant
151 that don't belong in the type.
152 Yield 1 if a signed overflow occurs, 0 otherwise.
153 If OVERFLOW is nonzero, a signed overflow has already occurred
154 in calculating T, so propagate it.
156 Make the real constant T valid for its type by calling CHECK_FLOAT_VALUE,
160 force_fit_type (t, overflow)
164 HOST_WIDE_INT low, high;
167 if (TREE_CODE (t) == REAL_CST)
169 #ifdef CHECK_FLOAT_VALUE
170 CHECK_FLOAT_VALUE (TYPE_MODE (TREE_TYPE (t)), TREE_REAL_CST (t),
176 else if (TREE_CODE (t) != INTEGER_CST)
179 low = TREE_INT_CST_LOW (t);
180 high = TREE_INT_CST_HIGH (t);
182 if (POINTER_TYPE_P (TREE_TYPE (t)))
185 prec = TYPE_PRECISION (TREE_TYPE (t));
187 /* First clear all bits that are beyond the type's precision. */
189 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
191 else if (prec > HOST_BITS_PER_WIDE_INT)
193 TREE_INT_CST_HIGH (t)
194 &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
198 TREE_INT_CST_HIGH (t) = 0;
199 if (prec < HOST_BITS_PER_WIDE_INT)
200 TREE_INT_CST_LOW (t) &= ~((HOST_WIDE_INT) (-1) << prec);
203 /* Unsigned types do not suffer sign extension or overflow. */
204 if (TREE_UNSIGNED (TREE_TYPE (t)))
207 /* If the value's sign bit is set, extend the sign. */
208 if (prec != 2 * HOST_BITS_PER_WIDE_INT
209 && (prec > HOST_BITS_PER_WIDE_INT
210 ? (TREE_INT_CST_HIGH (t)
211 & ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)))
212 : TREE_INT_CST_LOW (t) & ((HOST_WIDE_INT) 1 << (prec - 1))))
214 /* Value is negative:
215 set to 1 all the bits that are outside this type's precision. */
216 if (prec > HOST_BITS_PER_WIDE_INT)
218 TREE_INT_CST_HIGH (t)
219 |= ((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
223 TREE_INT_CST_HIGH (t) = -1;
224 if (prec < HOST_BITS_PER_WIDE_INT)
225 TREE_INT_CST_LOW (t) |= ((HOST_WIDE_INT) (-1) << prec);
229 /* Yield nonzero if signed overflow occurred. */
231 ((overflow | (low ^ TREE_INT_CST_LOW (t)) | (high ^ TREE_INT_CST_HIGH (t)))
235 /* Add two doubleword integers with doubleword result.
236 Each argument is given as two `HOST_WIDE_INT' pieces.
237 One argument is L1 and H1; the other, L2 and H2.
238 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
241 add_double (l1, h1, l2, h2, lv, hv)
242 HOST_WIDE_INT l1, h1, l2, h2;
243 HOST_WIDE_INT *lv, *hv;
248 h = h1 + h2 + ((unsigned HOST_WIDE_INT) l < l1);
252 return overflow_sum_sign (h1, h2, h);
255 /* Negate a doubleword integer with doubleword result.
256 Return nonzero if the operation overflows, assuming it's signed.
257 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
258 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
261 neg_double (l1, h1, lv, hv)
262 HOST_WIDE_INT l1, h1;
263 HOST_WIDE_INT *lv, *hv;
269 return (*hv & h1) < 0;
279 /* Multiply two doubleword integers with doubleword result.
280 Return nonzero if the operation overflows, assuming it's signed.
281 Each argument is given as two `HOST_WIDE_INT' pieces.
282 One argument is L1 and H1; the other, L2 and H2.
283 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
286 mul_double (l1, h1, l2, h2, lv, hv)
287 HOST_WIDE_INT l1, h1, l2, h2;
288 HOST_WIDE_INT *lv, *hv;
290 HOST_WIDE_INT arg1[4];
291 HOST_WIDE_INT arg2[4];
292 HOST_WIDE_INT prod[4 * 2];
293 register unsigned HOST_WIDE_INT carry;
294 register int i, j, k;
295 HOST_WIDE_INT toplow, tophigh, neglow, neghigh;
297 encode (arg1, l1, h1);
298 encode (arg2, l2, h2);
300 bzero ((char *) prod, sizeof prod);
302 for (i = 0; i < 4; i++)
305 for (j = 0; j < 4; j++)
308 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
309 carry += arg1[i] * arg2[j];
310 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
312 prod[k] = LOWPART (carry);
313 carry = HIGHPART (carry);
318 decode (prod, lv, hv); /* This ignores prod[4] through prod[4*2-1] */
320 /* Check for overflow by calculating the top half of the answer in full;
321 it should agree with the low half's sign bit. */
322 decode (prod+4, &toplow, &tophigh);
325 neg_double (l2, h2, &neglow, &neghigh);
326 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
330 neg_double (l1, h1, &neglow, &neghigh);
331 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
333 return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
336 /* Shift the doubleword integer in L1, H1 left by COUNT places
337 keeping only PREC bits of result.
338 Shift right if COUNT is negative.
339 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
340 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
343 lshift_double (l1, h1, count, prec, lv, hv, arith)
344 HOST_WIDE_INT l1, h1, count;
346 HOST_WIDE_INT *lv, *hv;
351 rshift_double (l1, h1, - count, prec, lv, hv, arith);
355 #ifdef SHIFT_COUNT_TRUNCATED
356 if (SHIFT_COUNT_TRUNCATED)
360 if (count >= HOST_BITS_PER_WIDE_INT)
362 *hv = (unsigned HOST_WIDE_INT) l1 << (count - HOST_BITS_PER_WIDE_INT);
367 *hv = (((unsigned HOST_WIDE_INT) h1 << count)
368 | ((unsigned HOST_WIDE_INT) l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
369 *lv = (unsigned HOST_WIDE_INT) l1 << count;
373 /* Shift the doubleword integer in L1, H1 right by COUNT places
374 keeping only PREC bits of result. COUNT must be positive.
375 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
376 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
379 rshift_double (l1, h1, count, prec, lv, hv, arith)
380 HOST_WIDE_INT l1, h1, count;
381 int prec ATTRIBUTE_UNUSED;
382 HOST_WIDE_INT *lv, *hv;
385 unsigned HOST_WIDE_INT signmask;
387 ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
390 #ifdef SHIFT_COUNT_TRUNCATED
391 if (SHIFT_COUNT_TRUNCATED)
395 if (count >= HOST_BITS_PER_WIDE_INT)
398 *lv = ((signmask << (2 * HOST_BITS_PER_WIDE_INT - count - 1) << 1)
399 | ((unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT)));
403 *lv = (((unsigned HOST_WIDE_INT) l1 >> count)
404 | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
405 *hv = ((signmask << (HOST_BITS_PER_WIDE_INT - count))
406 | ((unsigned HOST_WIDE_INT) h1 >> count));
410 /* Rotate the doubleword integer in L1, H1 left by COUNT places
411 keeping only PREC bits of result.
412 Rotate right if COUNT is negative.
413 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
416 lrotate_double (l1, h1, count, prec, lv, hv)
417 HOST_WIDE_INT l1, h1, count;
419 HOST_WIDE_INT *lv, *hv;
421 HOST_WIDE_INT s1l, s1h, s2l, s2h;
427 lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
428 rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
433 /* Rotate the doubleword integer in L1, H1 left by COUNT places
434 keeping only PREC bits of result. COUNT must be positive.
435 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
438 rrotate_double (l1, h1, count, prec, lv, hv)
439 HOST_WIDE_INT l1, h1, count;
441 HOST_WIDE_INT *lv, *hv;
443 HOST_WIDE_INT s1l, s1h, s2l, s2h;
449 rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
450 lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
455 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
456 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
457 CODE is a tree code for a kind of division, one of
458 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
460 It controls how the quotient is rounded to a integer.
461 Return nonzero if the operation overflows.
462 UNS nonzero says do unsigned division. */
465 div_and_round_double (code, uns,
466 lnum_orig, hnum_orig, lden_orig, hden_orig,
467 lquo, hquo, lrem, hrem)
470 HOST_WIDE_INT lnum_orig, hnum_orig; /* num == numerator == dividend */
471 HOST_WIDE_INT lden_orig, hden_orig; /* den == denominator == divisor */
472 HOST_WIDE_INT *lquo, *hquo, *lrem, *hrem;
475 HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
476 HOST_WIDE_INT den[4], quo[4];
478 unsigned HOST_WIDE_INT work;
479 register unsigned HOST_WIDE_INT carry = 0;
480 HOST_WIDE_INT lnum = lnum_orig;
481 HOST_WIDE_INT hnum = hnum_orig;
482 HOST_WIDE_INT lden = lden_orig;
483 HOST_WIDE_INT hden = hden_orig;
486 if ((hden == 0) && (lden == 0))
487 overflow = 1, lden = 1;
489 /* calculate quotient sign and convert operands to unsigned. */
495 /* (minimum integer) / (-1) is the only overflow case. */
496 if (neg_double (lnum, hnum, &lnum, &hnum) && (lden & hden) == -1)
502 neg_double (lden, hden, &lden, &hden);
506 if (hnum == 0 && hden == 0)
507 { /* single precision */
509 /* This unsigned division rounds toward zero. */
510 *lquo = lnum / (unsigned HOST_WIDE_INT) lden;
515 { /* trivial case: dividend < divisor */
516 /* hden != 0 already checked. */
523 bzero ((char *) quo, sizeof quo);
525 bzero ((char *) num, sizeof num); /* to zero 9th element */
526 bzero ((char *) den, sizeof den);
528 encode (num, lnum, hnum);
529 encode (den, lden, hden);
531 /* Special code for when the divisor < BASE. */
532 if (hden == 0 && lden < (HOST_WIDE_INT) BASE)
534 /* hnum != 0 already checked. */
535 for (i = 4 - 1; i >= 0; i--)
537 work = num[i] + carry * BASE;
538 quo[i] = work / (unsigned HOST_WIDE_INT) lden;
539 carry = work % (unsigned HOST_WIDE_INT) lden;
544 /* Full double precision division,
545 with thanks to Don Knuth's "Seminumerical Algorithms". */
546 int num_hi_sig, den_hi_sig;
547 unsigned HOST_WIDE_INT quo_est, scale;
549 /* Find the highest non-zero divisor digit. */
550 for (i = 4 - 1; ; i--)
556 /* Insure that the first digit of the divisor is at least BASE/2.
557 This is required by the quotient digit estimation algorithm. */
559 scale = BASE / (den[den_hi_sig] + 1);
560 if (scale > 1) { /* scale divisor and dividend */
562 for (i = 0; i <= 4 - 1; i++) {
563 work = (num[i] * scale) + carry;
564 num[i] = LOWPART (work);
565 carry = HIGHPART (work);
568 for (i = 0; i <= 4 - 1; i++) {
569 work = (den[i] * scale) + carry;
570 den[i] = LOWPART (work);
571 carry = HIGHPART (work);
572 if (den[i] != 0) den_hi_sig = i;
579 for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--) {
580 /* guess the next quotient digit, quo_est, by dividing the first
581 two remaining dividend digits by the high order quotient digit.
582 quo_est is never low and is at most 2 high. */
583 unsigned HOST_WIDE_INT tmp;
585 num_hi_sig = i + den_hi_sig + 1;
586 work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
587 if (num[num_hi_sig] != den[den_hi_sig])
588 quo_est = work / den[den_hi_sig];
592 /* refine quo_est so it's usually correct, and at most one high. */
593 tmp = work - quo_est * den[den_hi_sig];
595 && den[den_hi_sig - 1] * quo_est > (tmp * BASE + num[num_hi_sig - 2]))
598 /* Try QUO_EST as the quotient digit, by multiplying the
599 divisor by QUO_EST and subtracting from the remaining dividend.
600 Keep in mind that QUO_EST is the I - 1st digit. */
603 for (j = 0; j <= den_hi_sig; j++)
605 work = quo_est * den[j] + carry;
606 carry = HIGHPART (work);
607 work = num[i + j] - LOWPART (work);
608 num[i + j] = LOWPART (work);
609 carry += HIGHPART (work) != 0;
612 /* if quo_est was high by one, then num[i] went negative and
613 we need to correct things. */
615 if (num[num_hi_sig] < carry)
618 carry = 0; /* add divisor back in */
619 for (j = 0; j <= den_hi_sig; j++)
621 work = num[i + j] + den[j] + carry;
622 carry = HIGHPART (work);
623 num[i + j] = LOWPART (work);
625 num [num_hi_sig] += carry;
628 /* store the quotient digit. */
633 decode (quo, lquo, hquo);
636 /* if result is negative, make it so. */
638 neg_double (*lquo, *hquo, lquo, hquo);
640 /* compute trial remainder: rem = num - (quo * den) */
641 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
642 neg_double (*lrem, *hrem, lrem, hrem);
643 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
648 case TRUNC_MOD_EXPR: /* round toward zero */
649 case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
653 case FLOOR_MOD_EXPR: /* round toward negative infinity */
654 if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
657 add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
660 else return overflow;
664 case CEIL_MOD_EXPR: /* round toward positive infinity */
665 if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
667 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
670 else return overflow;
674 case ROUND_MOD_EXPR: /* round to closest integer */
676 HOST_WIDE_INT labs_rem = *lrem, habs_rem = *hrem;
677 HOST_WIDE_INT labs_den = lden, habs_den = hden, ltwice, htwice;
679 /* get absolute values */
680 if (*hrem < 0) neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
681 if (hden < 0) neg_double (lden, hden, &labs_den, &habs_den);
683 /* if (2 * abs (lrem) >= abs (lden)) */
684 mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
685 labs_rem, habs_rem, <wice, &htwice);
686 if (((unsigned HOST_WIDE_INT) habs_den
687 < (unsigned HOST_WIDE_INT) htwice)
688 || (((unsigned HOST_WIDE_INT) habs_den
689 == (unsigned HOST_WIDE_INT) htwice)
690 && ((HOST_WIDE_INT unsigned) labs_den
691 < (unsigned HOST_WIDE_INT) ltwice)))
695 add_double (*lquo, *hquo,
696 (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
699 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
702 else return overflow;
710 /* compute true remainder: rem = num - (quo * den) */
711 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
712 neg_double (*lrem, *hrem, lrem, hrem);
713 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
717 #ifndef REAL_ARITHMETIC
718 /* Effectively truncate a real value to represent the nearest possible value
719 in a narrower mode. The result is actually represented in the same data
720 type as the argument, but its value is usually different.
722 A trap may occur during the FP operations and it is the responsibility
723 of the calling function to have a handler established. */
726 real_value_truncate (mode, arg)
727 enum machine_mode mode;
730 return REAL_VALUE_TRUNCATE (mode, arg);
733 #if TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
735 /* Check for infinity in an IEEE double precision number. */
741 /* The IEEE 64-bit double format. */
746 unsigned exponent : 11;
747 unsigned mantissa1 : 20;
752 unsigned mantissa1 : 20;
753 unsigned exponent : 11;
759 if (u.big_endian.sign == 1)
762 return (u.big_endian.exponent == 2047
763 && u.big_endian.mantissa1 == 0
764 && u.big_endian.mantissa2 == 0);
769 return (u.little_endian.exponent == 2047
770 && u.little_endian.mantissa1 == 0
771 && u.little_endian.mantissa2 == 0);
775 /* Check whether an IEEE double precision number is a NaN. */
781 /* The IEEE 64-bit double format. */
786 unsigned exponent : 11;
787 unsigned mantissa1 : 20;
792 unsigned mantissa1 : 20;
793 unsigned exponent : 11;
799 if (u.big_endian.sign == 1)
802 return (u.big_endian.exponent == 2047
803 && (u.big_endian.mantissa1 != 0
804 || u.big_endian.mantissa2 != 0));
809 return (u.little_endian.exponent == 2047
810 && (u.little_endian.mantissa1 != 0
811 || u.little_endian.mantissa2 != 0));
815 /* Check for a negative IEEE double precision number. */
821 /* The IEEE 64-bit double format. */
826 unsigned exponent : 11;
827 unsigned mantissa1 : 20;
832 unsigned mantissa1 : 20;
833 unsigned exponent : 11;
839 if (u.big_endian.sign == 1)
842 return u.big_endian.sign;
847 return u.little_endian.sign;
850 #else /* Target not IEEE */
852 /* Let's assume other float formats don't have infinity.
853 (This can be overridden by redefining REAL_VALUE_ISINF.) */
861 /* Let's assume other float formats don't have NaNs.
862 (This can be overridden by redefining REAL_VALUE_ISNAN.) */
870 /* Let's assume other float formats don't have minus zero.
871 (This can be overridden by redefining REAL_VALUE_NEGATIVE.) */
878 #endif /* Target not IEEE */
880 /* Try to change R into its exact multiplicative inverse in machine mode
881 MODE. Return nonzero function value if successful. */
884 exact_real_inverse (mode, r)
885 enum machine_mode mode;
896 /* Usually disable if bounds checks are not reliable. */
897 if ((HOST_FLOAT_FORMAT != TARGET_FLOAT_FORMAT) && !flag_pretend_float)
900 /* Set array index to the less significant bits in the unions, depending
901 on the endian-ness of the host doubles.
902 Disable if insufficient information on the data structure. */
903 #if HOST_FLOAT_FORMAT == UNKNOWN_FLOAT_FORMAT
906 #if HOST_FLOAT_FORMAT == VAX_FLOAT_FORMAT
909 #if HOST_FLOAT_FORMAT == IBM_FLOAT_FORMAT
912 #define K (2 * HOST_FLOAT_WORDS_BIG_ENDIAN)
917 if (setjmp (float_error))
919 /* Don't do the optimization if there was an arithmetic error. */
921 set_float_handler (NULL_PTR);
924 set_float_handler (float_error);
926 /* Domain check the argument. */
932 if (REAL_VALUE_ISINF (x.d) || REAL_VALUE_ISNAN (x.d))
936 /* Compute the reciprocal and check for numerical exactness.
937 It is unnecessary to check all the significand bits to determine
938 whether X is a power of 2. If X is not, then it is impossible for
939 the bottom half significand of both X and 1/X to be all zero bits.
940 Hence we ignore the data structure of the top half and examine only
941 the low order bits of the two significands. */
943 if (x.i[K] != 0 || x.i[K + 1] != 0 || t.i[K] != 0 || t.i[K + 1] != 0)
946 /* Truncate to the required mode and range-check the result. */
947 y.d = REAL_VALUE_TRUNCATE (mode, t.d);
948 #ifdef CHECK_FLOAT_VALUE
950 if (CHECK_FLOAT_VALUE (mode, y.d, i))
954 /* Fail if truncation changed the value. */
955 if (y.d != t.d || y.d == 0.0)
959 if (REAL_VALUE_ISINF (y.d) || REAL_VALUE_ISNAN (y.d))
963 /* Output the reciprocal and return success flag. */
964 set_float_handler (NULL_PTR);
970 /* Convert C9X hexadecimal floating point string constant S. Return
971 real value type in mode MODE. This function uses the host computer's
972 fp arithmetic when there is no REAL_ARITHMETIC. */
975 real_hex_to_f (s, mode)
977 enum machine_mode mode;
981 unsigned HOST_WIDE_INT low, high;
982 int frexpon, expon, shcount, nrmcount, k;
983 int sign, expsign, decpt, isfloat, isldouble, gotp, lost;
993 while (*p == ' ' || *p == '\t')
996 /* Sign, if any, comes first. */
1004 /* The string is supposed to start with 0x or 0X . */
1008 if (*p == 'x' || *p == 'X')
1021 lost = 0; /* Nonzero low order bits shifted out and discarded. */
1022 frexpon = 0; /* Bits after the decimal point. */
1023 expon = 0; /* Value of exponent. */
1024 decpt = 0; /* How many decimal points. */
1025 gotp = 0; /* How many P's. */
1027 while ((c = *p) != '\0')
1029 if ((c >= '0' && c <= '9') || (c >= 'A' && c <= 'F')
1030 || (c >= 'a' && c <= 'f'))
1040 if ((high & 0xf0000000) == 0)
1042 high = (high << 4) + ((low >> 28) & 15);
1043 low = (low << 4) + k;
1050 /* Record nonzero lost bits. */
1062 else if (c == 'p' || c == 'P')
1066 /* Sign of exponent. */
1072 /* Value of exponent.
1073 The exponent field is a decimal integer. */
1076 k = (*p++ & 0x7f) - '0';
1077 expon = 10 * expon + k;
1080 /* F suffix is ambiguous in the significand part
1081 so it must appear after the decimal exponent field. */
1082 if (*p == 'f' || *p == 'F')
1089 else if (c == 'l' || c == 'L')
1098 /* Abort if last character read was not legitimate. */
1100 if ((c != '\0' && c != ' ' && c != '\n' && c != '\r') || (decpt > 1))
1102 /* There must be either one decimal point or one p. */
1103 if (decpt == 0 && gotp == 0)
1106 if ((high == 0) && (low == 0))
1119 /* Leave a high guard bit for carry-out. */
1120 if ((high & 0x80000000) != 0)
1123 low = (low >> 1) | (high << 31);
1127 if ((high & 0xffff8000) == 0)
1129 high = (high << 16) + ((low >> 16) & 0xffff);
1133 while ((high & 0xc0000000) == 0)
1135 high = (high << 1) + ((low >> 31) & 1);
1139 if (isfloat || GET_MODE_SIZE(mode) == UNITS_PER_WORD)
1141 /* Keep 24 bits precision, bits 0x7fffff80.
1142 Rounding bit is 0x40. */
1143 lost = lost | low | (high & 0x3f);
1147 if ((high & 0x80) || lost)
1154 /* We need real.c to do long double formats, so here default
1155 to double precision. */
1156 #if HOST_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
1158 Keep 53 bits precision, bits 0x7fffffff fffffc00.
1159 Rounding bit is low word 0x200. */
1160 lost = lost | (low & 0x1ff);
1163 if ((low & 0x400) || lost)
1165 low = (low + 0x200) & 0xfffffc00;
1172 /* Assume it's a VAX with 56-bit significand,
1173 bits 0x7fffffff ffffff80. */
1174 lost = lost | (low & 0x7f);
1177 if ((low & 0x80) || lost)
1179 low = (low + 0x40) & 0xffffff80;
1188 ip = REAL_VALUE_LDEXP (ip, 32) + (double) low;
1189 /* Apply shifts and exponent value as power of 2. */
1190 ip = REAL_VALUE_LDEXP (ip, expon - (nrmcount + frexpon));
1197 #endif /* no REAL_ARITHMETIC */
1199 /* Split a tree IN into a constant and a variable part
1200 that could be combined with CODE to make IN.
1201 CODE must be a commutative arithmetic operation.
1202 Store the constant part into *CONP and the variable in &VARP.
1203 Return 1 if this was done; zero means the tree IN did not decompose
1206 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR.
1207 Therefore, we must tell the caller whether the variable part
1208 was subtracted. We do this by storing 1 or -1 into *VARSIGNP.
1209 The value stored is the coefficient for the variable term.
1210 The constant term we return should always be added;
1211 we negate it if necessary. */
1214 split_tree (in, code, varp, conp, varsignp)
1216 enum tree_code code;
1220 register tree outtype = TREE_TYPE (in);
1224 /* Strip any conversions that don't change the machine mode. */
1225 while ((TREE_CODE (in) == NOP_EXPR
1226 || TREE_CODE (in) == CONVERT_EXPR)
1227 && (TYPE_MODE (TREE_TYPE (in))
1228 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (in, 0)))))
1229 in = TREE_OPERAND (in, 0);
1231 if (TREE_CODE (in) == code
1232 || (! FLOAT_TYPE_P (TREE_TYPE (in))
1233 /* We can associate addition and subtraction together
1234 (even though the C standard doesn't say so)
1235 for integers because the value is not affected.
1236 For reals, the value might be affected, so we can't. */
1237 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
1238 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
1240 enum tree_code code = TREE_CODE (TREE_OPERAND (in, 0));
1241 if (code == INTEGER_CST)
1243 *conp = TREE_OPERAND (in, 0);
1244 *varp = TREE_OPERAND (in, 1);
1245 if (TYPE_MODE (TREE_TYPE (*varp)) != TYPE_MODE (outtype)
1246 && TREE_TYPE (*varp) != outtype)
1247 *varp = convert (outtype, *varp);
1248 *varsignp = (TREE_CODE (in) == MINUS_EXPR) ? -1 : 1;
1251 if (TREE_CONSTANT (TREE_OPERAND (in, 1)))
1253 *conp = TREE_OPERAND (in, 1);
1254 *varp = TREE_OPERAND (in, 0);
1256 if (TYPE_MODE (TREE_TYPE (*varp)) != TYPE_MODE (outtype)
1257 && TREE_TYPE (*varp) != outtype)
1258 *varp = convert (outtype, *varp);
1259 if (TREE_CODE (in) == MINUS_EXPR)
1261 /* If operation is subtraction and constant is second,
1262 must negate it to get an additive constant.
1263 And this cannot be done unless it is a manifest constant.
1264 It could also be the address of a static variable.
1265 We cannot negate that, so give up. */
1266 if (TREE_CODE (*conp) == INTEGER_CST)
1267 /* Subtracting from integer_zero_node loses for long long. */
1268 *conp = fold (build1 (NEGATE_EXPR, TREE_TYPE (*conp), *conp));
1274 if (TREE_CONSTANT (TREE_OPERAND (in, 0)))
1276 *conp = TREE_OPERAND (in, 0);
1277 *varp = TREE_OPERAND (in, 1);
1278 if (TYPE_MODE (TREE_TYPE (*varp)) != TYPE_MODE (outtype)
1279 && TREE_TYPE (*varp) != outtype)
1280 *varp = convert (outtype, *varp);
1281 *varsignp = (TREE_CODE (in) == MINUS_EXPR) ? -1 : 1;
1288 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1289 to produce a new constant.
1291 If NOTRUNC is nonzero, do not truncate the result to fit the data type.
1292 If FORSIZE is nonzero, compute overflow for unsigned types. */
1295 int_const_binop (code, arg1, arg2, notrunc, forsize)
1296 enum tree_code code;
1297 register tree arg1, arg2;
1298 int notrunc, forsize;
1300 HOST_WIDE_INT int1l, int1h, int2l, int2h;
1301 HOST_WIDE_INT low, hi;
1302 HOST_WIDE_INT garbagel, garbageh;
1304 int uns = TREE_UNSIGNED (TREE_TYPE (arg1));
1306 int no_overflow = 0;
1308 int1l = TREE_INT_CST_LOW (arg1);
1309 int1h = TREE_INT_CST_HIGH (arg1);
1310 int2l = TREE_INT_CST_LOW (arg2);
1311 int2h = TREE_INT_CST_HIGH (arg2);
1316 low = int1l | int2l, hi = int1h | int2h;
1320 low = int1l ^ int2l, hi = int1h ^ int2h;
1324 low = int1l & int2l, hi = int1h & int2h;
1327 case BIT_ANDTC_EXPR:
1328 low = int1l & ~int2l, hi = int1h & ~int2h;
1334 /* It's unclear from the C standard whether shifts can overflow.
1335 The following code ignores overflow; perhaps a C standard
1336 interpretation ruling is needed. */
1337 lshift_double (int1l, int1h, int2l,
1338 TYPE_PRECISION (TREE_TYPE (arg1)),
1347 lrotate_double (int1l, int1h, int2l,
1348 TYPE_PRECISION (TREE_TYPE (arg1)),
1353 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1357 neg_double (int2l, int2h, &low, &hi);
1358 add_double (int1l, int1h, low, hi, &low, &hi);
1359 overflow = overflow_sum_sign (hi, int2h, int1h);
1363 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1366 case TRUNC_DIV_EXPR:
1367 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1368 case EXACT_DIV_EXPR:
1369 /* This is a shortcut for a common special case. */
1370 if (int2h == 0 && int2l > 0
1371 && ! TREE_CONSTANT_OVERFLOW (arg1)
1372 && ! TREE_CONSTANT_OVERFLOW (arg2)
1373 && int1h == 0 && int1l >= 0)
1375 if (code == CEIL_DIV_EXPR)
1377 low = int1l / int2l, hi = 0;
1381 /* ... fall through ... */
1383 case ROUND_DIV_EXPR:
1384 if (int2h == 0 && int2l == 1)
1386 low = int1l, hi = int1h;
1389 if (int1l == int2l && int1h == int2h
1390 && ! (int1l == 0 && int1h == 0))
1395 overflow = div_and_round_double (code, uns,
1396 int1l, int1h, int2l, int2h,
1397 &low, &hi, &garbagel, &garbageh);
1400 case TRUNC_MOD_EXPR:
1401 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1402 /* This is a shortcut for a common special case. */
1403 if (int2h == 0 && int2l > 0
1404 && ! TREE_CONSTANT_OVERFLOW (arg1)
1405 && ! TREE_CONSTANT_OVERFLOW (arg2)
1406 && int1h == 0 && int1l >= 0)
1408 if (code == CEIL_MOD_EXPR)
1410 low = int1l % int2l, hi = 0;
1414 /* ... fall through ... */
1416 case ROUND_MOD_EXPR:
1417 overflow = div_and_round_double (code, uns,
1418 int1l, int1h, int2l, int2h,
1419 &garbagel, &garbageh, &low, &hi);
1426 low = (((unsigned HOST_WIDE_INT) int1h
1427 < (unsigned HOST_WIDE_INT) int2h)
1428 || (((unsigned HOST_WIDE_INT) int1h
1429 == (unsigned HOST_WIDE_INT) int2h)
1430 && ((unsigned HOST_WIDE_INT) int1l
1431 < (unsigned HOST_WIDE_INT) int2l)));
1435 low = ((int1h < int2h)
1436 || ((int1h == int2h)
1437 && ((unsigned HOST_WIDE_INT) int1l
1438 < (unsigned HOST_WIDE_INT) int2l)));
1440 if (low == (code == MIN_EXPR))
1441 low = int1l, hi = int1h;
1443 low = int2l, hi = int2h;
1450 if (TREE_TYPE (arg1) == sizetype && hi == 0
1452 && (TYPE_MAX_VALUE (sizetype) == NULL
1453 || low <= TREE_INT_CST_LOW (TYPE_MAX_VALUE (sizetype)))
1455 && ! TREE_OVERFLOW (arg1) && ! TREE_OVERFLOW (arg2))
1459 t = build_int_2 (low, hi);
1460 TREE_TYPE (t) = TREE_TYPE (arg1);
1464 = ((notrunc ? (!uns || forsize) && overflow
1465 : force_fit_type (t, (!uns || forsize) && overflow) && ! no_overflow)
1466 | TREE_OVERFLOW (arg1)
1467 | TREE_OVERFLOW (arg2));
1468 /* If we're doing a size calculation, unsigned arithmetic does overflow.
1469 So check if force_fit_type truncated the value. */
1471 && ! TREE_OVERFLOW (t)
1472 && (TREE_INT_CST_HIGH (t) != hi
1473 || TREE_INT_CST_LOW (t) != low))
1474 TREE_OVERFLOW (t) = 1;
1475 TREE_CONSTANT_OVERFLOW (t) = (TREE_OVERFLOW (t)
1476 | TREE_CONSTANT_OVERFLOW (arg1)
1477 | TREE_CONSTANT_OVERFLOW (arg2));
1485 REAL_VALUE_TYPE d1, d2;
1486 enum tree_code code;
1492 const_binop_1 (data)
1495 struct cb_args * args = (struct cb_args *) data;
1496 REAL_VALUE_TYPE value;
1498 #ifdef REAL_ARITHMETIC
1499 REAL_ARITHMETIC (value, args->code, args->d1, args->d2);
1504 value = args->d1 + args->d2;
1508 value = args->d1 - args->d2;
1512 value = args->d1 * args->d2;
1516 #ifndef REAL_INFINITY
1521 value = args->d1 / args->d2;
1525 value = MIN (args->d1, args->d2);
1529 value = MAX (args->d1, args->d2);
1535 #endif /* no REAL_ARITHMETIC */
1537 build_real (TREE_TYPE (args->arg1),
1538 real_value_truncate (TYPE_MODE (TREE_TYPE (args->arg1)),
1542 /* Combine two constants ARG1 and ARG2 under operation CODE
1543 to produce a new constant.
1544 We assume ARG1 and ARG2 have the same data type,
1545 or at least are the same kind of constant and the same machine mode.
1547 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1550 const_binop (code, arg1, arg2, notrunc)
1551 enum tree_code code;
1552 register tree arg1, arg2;
1555 STRIP_NOPS (arg1); STRIP_NOPS (arg2);
1557 if (TREE_CODE (arg1) == INTEGER_CST)
1558 return int_const_binop (code, arg1, arg2, notrunc, 0);
1560 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1561 if (TREE_CODE (arg1) == REAL_CST)
1567 struct cb_args args;
1569 d1 = TREE_REAL_CST (arg1);
1570 d2 = TREE_REAL_CST (arg2);
1572 /* If either operand is a NaN, just return it. Otherwise, set up
1573 for floating-point trap; we return an overflow. */
1574 if (REAL_VALUE_ISNAN (d1))
1576 else if (REAL_VALUE_ISNAN (d2))
1579 /* Setup input for const_binop_1() */
1585 if (do_float_handler (const_binop_1, (PTR) &args))
1587 /* Receive output from const_binop_1() */
1592 /* We got an exception from const_binop_1() */
1593 t = copy_node (arg1);
1598 = (force_fit_type (t, overflow)
1599 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
1600 TREE_CONSTANT_OVERFLOW (t)
1602 | TREE_CONSTANT_OVERFLOW (arg1)
1603 | TREE_CONSTANT_OVERFLOW (arg2);
1606 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
1607 if (TREE_CODE (arg1) == COMPLEX_CST)
1609 register tree type = TREE_TYPE (arg1);
1610 register tree r1 = TREE_REALPART (arg1);
1611 register tree i1 = TREE_IMAGPART (arg1);
1612 register tree r2 = TREE_REALPART (arg2);
1613 register tree i2 = TREE_IMAGPART (arg2);
1619 t = build_complex (type,
1620 const_binop (PLUS_EXPR, r1, r2, notrunc),
1621 const_binop (PLUS_EXPR, i1, i2, notrunc));
1625 t = build_complex (type,
1626 const_binop (MINUS_EXPR, r1, r2, notrunc),
1627 const_binop (MINUS_EXPR, i1, i2, notrunc));
1631 t = build_complex (type,
1632 const_binop (MINUS_EXPR,
1633 const_binop (MULT_EXPR,
1635 const_binop (MULT_EXPR,
1638 const_binop (PLUS_EXPR,
1639 const_binop (MULT_EXPR,
1641 const_binop (MULT_EXPR,
1648 register tree magsquared
1649 = const_binop (PLUS_EXPR,
1650 const_binop (MULT_EXPR, r2, r2, notrunc),
1651 const_binop (MULT_EXPR, i2, i2, notrunc),
1654 t = build_complex (type,
1656 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1657 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1658 const_binop (PLUS_EXPR,
1659 const_binop (MULT_EXPR, r1, r2,
1661 const_binop (MULT_EXPR, i1, i2,
1664 magsquared, notrunc),
1666 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1667 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1668 const_binop (MINUS_EXPR,
1669 const_binop (MULT_EXPR, i1, r2,
1671 const_binop (MULT_EXPR, r1, i2,
1674 magsquared, notrunc));
1686 /* Return an INTEGER_CST with value V . The type is determined by bit_p:
1687 if it is zero, the type is taken from sizetype; if it is one, the type
1688 is taken from bitsizetype. */
1691 size_int_wide (number, high, bit_p)
1692 unsigned HOST_WIDE_INT number, high;
1696 /* Type-size nodes already made for small sizes. */
1697 static tree size_table[2*HOST_BITS_PER_WIDE_INT + 1][2];
1699 if (number < 2*HOST_BITS_PER_WIDE_INT + 1 && ! high
1700 && size_table[number][bit_p] != 0)
1701 return size_table[number][bit_p];
1702 if (number < 2*HOST_BITS_PER_WIDE_INT + 1 && ! high)
1704 push_obstacks_nochange ();
1705 /* Make this a permanent node. */
1706 end_temporary_allocation ();
1707 t = build_int_2 (number, 0);
1708 TREE_TYPE (t) = bit_p ? bitsizetype : sizetype;
1709 size_table[number][bit_p] = t;
1714 t = build_int_2 (number, high);
1715 TREE_TYPE (t) = bit_p ? bitsizetype : sizetype;
1716 TREE_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (t) = force_fit_type (t, 0);
1721 /* Combine operands OP1 and OP2 with arithmetic operation CODE.
1722 CODE is a tree code. Data type is taken from `sizetype',
1723 If the operands are constant, so is the result. */
1726 size_binop (code, arg0, arg1)
1727 enum tree_code code;
1730 /* Handle the special case of two integer constants faster. */
1731 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1733 /* And some specific cases even faster than that. */
1734 if (code == PLUS_EXPR && integer_zerop (arg0))
1736 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1737 && integer_zerop (arg1))
1739 else if (code == MULT_EXPR && integer_onep (arg0))
1742 /* Handle general case of two integer constants. */
1743 return int_const_binop (code, arg0, arg1, 0, 1);
1746 if (arg0 == error_mark_node || arg1 == error_mark_node)
1747 return error_mark_node;
1749 return fold (build (code, sizetype, arg0, arg1));
1752 /* Combine operands OP1 and OP2 with arithmetic operation CODE.
1753 CODE is a tree code. Data type is taken from `ssizetype',
1754 If the operands are constant, so is the result. */
1757 ssize_binop (code, arg0, arg1)
1758 enum tree_code code;
1761 /* Handle the special case of two integer constants faster. */
1762 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1764 /* And some specific cases even faster than that. */
1765 if (code == PLUS_EXPR && integer_zerop (arg0))
1767 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1768 && integer_zerop (arg1))
1770 else if (code == MULT_EXPR && integer_onep (arg0))
1773 /* Handle general case of two integer constants. We convert
1774 arg0 to ssizetype because int_const_binop uses its type for the
1776 arg0 = convert (ssizetype, arg0);
1777 return int_const_binop (code, arg0, arg1, 0, 0);
1780 if (arg0 == error_mark_node || arg1 == error_mark_node)
1781 return error_mark_node;
1783 return fold (build (code, ssizetype, arg0, arg1));
1795 fold_convert_1 (data)
1798 struct fc_args * args = (struct fc_args *) data;
1800 args->t = build_real (args->type,
1801 real_value_truncate (TYPE_MODE (args->type),
1802 TREE_REAL_CST (args->arg1)));
1805 /* Given T, a tree representing type conversion of ARG1, a constant,
1806 return a constant tree representing the result of conversion. */
1809 fold_convert (t, arg1)
1813 register tree type = TREE_TYPE (t);
1816 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
1818 if (TREE_CODE (arg1) == INTEGER_CST)
1820 /* If we would build a constant wider than GCC supports,
1821 leave the conversion unfolded. */
1822 if (TYPE_PRECISION (type) > 2 * HOST_BITS_PER_WIDE_INT)
1825 /* Given an integer constant, make new constant with new type,
1826 appropriately sign-extended or truncated. */
1827 t = build_int_2 (TREE_INT_CST_LOW (arg1),
1828 TREE_INT_CST_HIGH (arg1));
1829 TREE_TYPE (t) = type;
1830 /* Indicate an overflow if (1) ARG1 already overflowed,
1831 or (2) force_fit_type indicates an overflow.
1832 Tell force_fit_type that an overflow has already occurred
1833 if ARG1 is a too-large unsigned value and T is signed.
1834 But don't indicate an overflow if converting a pointer. */
1836 = ((force_fit_type (t,
1837 (TREE_INT_CST_HIGH (arg1) < 0
1838 && (TREE_UNSIGNED (type)
1839 < TREE_UNSIGNED (TREE_TYPE (arg1)))))
1840 && ! POINTER_TYPE_P (TREE_TYPE (arg1)))
1841 || TREE_OVERFLOW (arg1));
1842 TREE_CONSTANT_OVERFLOW (t)
1843 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1845 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1846 else if (TREE_CODE (arg1) == REAL_CST)
1848 /* Don't initialize these, use assignments.
1849 Initialized local aggregates don't work on old compilers. */
1853 tree type1 = TREE_TYPE (arg1);
1856 x = TREE_REAL_CST (arg1);
1857 l = real_value_from_int_cst (type1, TYPE_MIN_VALUE (type));
1859 no_upper_bound = (TYPE_MAX_VALUE (type) == NULL);
1860 if (!no_upper_bound)
1861 u = real_value_from_int_cst (type1, TYPE_MAX_VALUE (type));
1863 /* See if X will be in range after truncation towards 0.
1864 To compensate for truncation, move the bounds away from 0,
1865 but reject if X exactly equals the adjusted bounds. */
1866 #ifdef REAL_ARITHMETIC
1867 REAL_ARITHMETIC (l, MINUS_EXPR, l, dconst1);
1868 if (!no_upper_bound)
1869 REAL_ARITHMETIC (u, PLUS_EXPR, u, dconst1);
1872 if (!no_upper_bound)
1875 /* If X is a NaN, use zero instead and show we have an overflow.
1876 Otherwise, range check. */
1877 if (REAL_VALUE_ISNAN (x))
1878 overflow = 1, x = dconst0;
1879 else if (! (REAL_VALUES_LESS (l, x)
1881 && REAL_VALUES_LESS (x, u)))
1884 #ifndef REAL_ARITHMETIC
1886 HOST_WIDE_INT low, high;
1887 HOST_WIDE_INT half_word
1888 = (HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2);
1893 high = (HOST_WIDE_INT) (x / half_word / half_word);
1894 x -= (REAL_VALUE_TYPE) high * half_word * half_word;
1895 if (x >= (REAL_VALUE_TYPE) half_word * half_word / 2)
1897 low = x - (REAL_VALUE_TYPE) half_word * half_word / 2;
1898 low |= (HOST_WIDE_INT) -1 << (HOST_BITS_PER_WIDE_INT - 1);
1901 low = (HOST_WIDE_INT) x;
1902 if (TREE_REAL_CST (arg1) < 0)
1903 neg_double (low, high, &low, &high);
1904 t = build_int_2 (low, high);
1908 HOST_WIDE_INT low, high;
1909 REAL_VALUE_TO_INT (&low, &high, x);
1910 t = build_int_2 (low, high);
1913 TREE_TYPE (t) = type;
1915 = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
1916 TREE_CONSTANT_OVERFLOW (t)
1917 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1919 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
1920 TREE_TYPE (t) = type;
1922 else if (TREE_CODE (type) == REAL_TYPE)
1924 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1925 if (TREE_CODE (arg1) == INTEGER_CST)
1926 return build_real_from_int_cst (type, arg1);
1927 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
1928 if (TREE_CODE (arg1) == REAL_CST)
1930 struct fc_args args;
1932 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
1935 TREE_TYPE (arg1) = type;
1939 /* Setup input for fold_convert_1() */
1943 if (do_float_handler (fold_convert_1, (PTR) &args))
1945 /* Receive output from fold_convert_1() */
1950 /* We got an exception from fold_convert_1() */
1952 t = copy_node (arg1);
1956 = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
1957 TREE_CONSTANT_OVERFLOW (t)
1958 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1962 TREE_CONSTANT (t) = 1;
1966 /* Return an expr equal to X but certainly not valid as an lvalue. */
1974 /* These things are certainly not lvalues. */
1975 if (TREE_CODE (x) == NON_LVALUE_EXPR
1976 || TREE_CODE (x) == INTEGER_CST
1977 || TREE_CODE (x) == REAL_CST
1978 || TREE_CODE (x) == STRING_CST
1979 || TREE_CODE (x) == ADDR_EXPR)
1982 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
1983 TREE_CONSTANT (result) = TREE_CONSTANT (x);
1987 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
1988 Zero means allow extended lvalues. */
1990 int pedantic_lvalues;
1992 /* When pedantic, return an expr equal to X but certainly not valid as a
1993 pedantic lvalue. Otherwise, return X. */
1996 pedantic_non_lvalue (x)
1999 if (pedantic_lvalues)
2000 return non_lvalue (x);
2005 /* Given a tree comparison code, return the code that is the logical inverse
2006 of the given code. It is not safe to do this for floating-point
2007 comparisons, except for NE_EXPR and EQ_EXPR. */
2009 static enum tree_code
2010 invert_tree_comparison (code)
2011 enum tree_code code;
2032 /* Similar, but return the comparison that results if the operands are
2033 swapped. This is safe for floating-point. */
2035 static enum tree_code
2036 swap_tree_comparison (code)
2037 enum tree_code code;
2057 /* Return nonzero if CODE is a tree code that represents a truth value. */
2060 truth_value_p (code)
2061 enum tree_code code;
2063 return (TREE_CODE_CLASS (code) == '<'
2064 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2065 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2066 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
2069 /* Return nonzero if two operands are necessarily equal.
2070 If ONLY_CONST is non-zero, only return non-zero for constants.
2071 This function tests whether the operands are indistinguishable;
2072 it does not test whether they are equal using C's == operation.
2073 The distinction is important for IEEE floating point, because
2074 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2075 (2) two NaNs may be indistinguishable, but NaN!=NaN. */
2078 operand_equal_p (arg0, arg1, only_const)
2082 /* If both types don't have the same signedness, then we can't consider
2083 them equal. We must check this before the STRIP_NOPS calls
2084 because they may change the signedness of the arguments. */
2085 if (TREE_UNSIGNED (TREE_TYPE (arg0)) != TREE_UNSIGNED (TREE_TYPE (arg1)))
2091 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2092 /* This is needed for conversions and for COMPONENT_REF.
2093 Might as well play it safe and always test this. */
2094 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
2097 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
2098 We don't care about side effects in that case because the SAVE_EXPR
2099 takes care of that for us. In all other cases, two expressions are
2100 equal if they have no side effects. If we have two identical
2101 expressions with side effects that should be treated the same due
2102 to the only side effects being identical SAVE_EXPR's, that will
2103 be detected in the recursive calls below. */
2104 if (arg0 == arg1 && ! only_const
2105 && (TREE_CODE (arg0) == SAVE_EXPR
2106 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
2109 /* Next handle constant cases, those for which we can return 1 even
2110 if ONLY_CONST is set. */
2111 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
2112 switch (TREE_CODE (arg0))
2115 return (! TREE_CONSTANT_OVERFLOW (arg0)
2116 && ! TREE_CONSTANT_OVERFLOW (arg1)
2117 && TREE_INT_CST_LOW (arg0) == TREE_INT_CST_LOW (arg1)
2118 && TREE_INT_CST_HIGH (arg0) == TREE_INT_CST_HIGH (arg1));
2121 return (! TREE_CONSTANT_OVERFLOW (arg0)
2122 && ! TREE_CONSTANT_OVERFLOW (arg1)
2123 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
2124 TREE_REAL_CST (arg1)));
2127 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
2129 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
2133 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
2134 && ! strncmp (TREE_STRING_POINTER (arg0),
2135 TREE_STRING_POINTER (arg1),
2136 TREE_STRING_LENGTH (arg0)));
2139 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
2148 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
2151 /* Two conversions are equal only if signedness and modes match. */
2152 if ((TREE_CODE (arg0) == NOP_EXPR || TREE_CODE (arg0) == CONVERT_EXPR)
2153 && (TREE_UNSIGNED (TREE_TYPE (arg0))
2154 != TREE_UNSIGNED (TREE_TYPE (arg1))))
2157 return operand_equal_p (TREE_OPERAND (arg0, 0),
2158 TREE_OPERAND (arg1, 0), 0);
2162 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0)
2163 && operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1),
2167 /* For commutative ops, allow the other order. */
2168 return ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MULT_EXPR
2169 || TREE_CODE (arg0) == MIN_EXPR || TREE_CODE (arg0) == MAX_EXPR
2170 || TREE_CODE (arg0) == BIT_IOR_EXPR
2171 || TREE_CODE (arg0) == BIT_XOR_EXPR
2172 || TREE_CODE (arg0) == BIT_AND_EXPR
2173 || TREE_CODE (arg0) == NE_EXPR || TREE_CODE (arg0) == EQ_EXPR)
2174 && operand_equal_p (TREE_OPERAND (arg0, 0),
2175 TREE_OPERAND (arg1, 1), 0)
2176 && operand_equal_p (TREE_OPERAND (arg0, 1),
2177 TREE_OPERAND (arg1, 0), 0));
2180 switch (TREE_CODE (arg0))
2183 return operand_equal_p (TREE_OPERAND (arg0, 0),
2184 TREE_OPERAND (arg1, 0), 0);
2188 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2189 TREE_OPERAND (arg1, 0), 0)
2190 && operand_equal_p (TREE_OPERAND (arg0, 1),
2191 TREE_OPERAND (arg1, 1), 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)
2198 && operand_equal_p (TREE_OPERAND (arg0, 2),
2199 TREE_OPERAND (arg1, 2), 0));
2205 if (TREE_CODE (arg0) == RTL_EXPR)
2206 return rtx_equal_p (RTL_EXPR_RTL (arg0), RTL_EXPR_RTL (arg1));
2214 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2215 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2217 When in doubt, return 0. */
2220 operand_equal_for_comparison_p (arg0, arg1, other)
2224 int unsignedp1, unsignedpo;
2225 tree primarg0, primarg1, primother;
2226 unsigned correct_width;
2228 if (operand_equal_p (arg0, arg1, 0))
2231 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
2232 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
2235 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2236 and see if the inner values are the same. This removes any
2237 signedness comparison, which doesn't matter here. */
2238 primarg0 = arg0, primarg1 = arg1;
2239 STRIP_NOPS (primarg0); STRIP_NOPS (primarg1);
2240 if (operand_equal_p (primarg0, primarg1, 0))
2243 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2244 actual comparison operand, ARG0.
2246 First throw away any conversions to wider types
2247 already present in the operands. */
2249 primarg1 = get_narrower (arg1, &unsignedp1);
2250 primother = get_narrower (other, &unsignedpo);
2252 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
2253 if (unsignedp1 == unsignedpo
2254 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
2255 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
2257 tree type = TREE_TYPE (arg0);
2259 /* Make sure shorter operand is extended the right way
2260 to match the longer operand. */
2261 primarg1 = convert (signed_or_unsigned_type (unsignedp1,
2262 TREE_TYPE (primarg1)),
2265 if (operand_equal_p (arg0, convert (type, primarg1), 0))
2272 /* See if ARG is an expression that is either a comparison or is performing
2273 arithmetic on comparisons. The comparisons must only be comparing
2274 two different values, which will be stored in *CVAL1 and *CVAL2; if
2275 they are non-zero it means that some operands have already been found.
2276 No variables may be used anywhere else in the expression except in the
2277 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2278 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2280 If this is true, return 1. Otherwise, return zero. */
2283 twoval_comparison_p (arg, cval1, cval2, save_p)
2285 tree *cval1, *cval2;
2288 enum tree_code code = TREE_CODE (arg);
2289 char class = TREE_CODE_CLASS (code);
2291 /* We can handle some of the 'e' cases here. */
2292 if (class == 'e' && code == TRUTH_NOT_EXPR)
2294 else if (class == 'e'
2295 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
2296 || code == COMPOUND_EXPR))
2299 /* ??? Disable this since the SAVE_EXPR might already be in use outside
2300 the expression. There may be no way to make this work, but it needs
2301 to be looked at again for 2.6. */
2303 else if (class == 'e' && code == SAVE_EXPR && SAVE_EXPR_RTL (arg) == 0)
2305 /* If we've already found a CVAL1 or CVAL2, this expression is
2306 two complex to handle. */
2307 if (*cval1 || *cval2)
2318 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
2321 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
2322 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2323 cval1, cval2, save_p));
2329 if (code == COND_EXPR)
2330 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
2331 cval1, cval2, save_p)
2332 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2333 cval1, cval2, save_p)
2334 && twoval_comparison_p (TREE_OPERAND (arg, 2),
2335 cval1, cval2, save_p));
2339 /* First see if we can handle the first operand, then the second. For
2340 the second operand, we know *CVAL1 can't be zero. It must be that
2341 one side of the comparison is each of the values; test for the
2342 case where this isn't true by failing if the two operands
2345 if (operand_equal_p (TREE_OPERAND (arg, 0),
2346 TREE_OPERAND (arg, 1), 0))
2350 *cval1 = TREE_OPERAND (arg, 0);
2351 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
2353 else if (*cval2 == 0)
2354 *cval2 = TREE_OPERAND (arg, 0);
2355 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
2360 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
2362 else if (*cval2 == 0)
2363 *cval2 = TREE_OPERAND (arg, 1);
2364 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
2376 /* ARG is a tree that is known to contain just arithmetic operations and
2377 comparisons. Evaluate the operations in the tree substituting NEW0 for
2378 any occurrence of OLD0 as an operand of a comparison and likewise for
2382 eval_subst (arg, old0, new0, old1, new1)
2384 tree old0, new0, old1, new1;
2386 tree type = TREE_TYPE (arg);
2387 enum tree_code code = TREE_CODE (arg);
2388 char class = TREE_CODE_CLASS (code);
2390 /* We can handle some of the 'e' cases here. */
2391 if (class == 'e' && code == TRUTH_NOT_EXPR)
2393 else if (class == 'e'
2394 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2400 return fold (build1 (code, type,
2401 eval_subst (TREE_OPERAND (arg, 0),
2402 old0, new0, old1, new1)));
2405 return fold (build (code, type,
2406 eval_subst (TREE_OPERAND (arg, 0),
2407 old0, new0, old1, new1),
2408 eval_subst (TREE_OPERAND (arg, 1),
2409 old0, new0, old1, new1)));
2415 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
2418 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
2421 return fold (build (code, type,
2422 eval_subst (TREE_OPERAND (arg, 0),
2423 old0, new0, old1, new1),
2424 eval_subst (TREE_OPERAND (arg, 1),
2425 old0, new0, old1, new1),
2426 eval_subst (TREE_OPERAND (arg, 2),
2427 old0, new0, old1, new1)));
2431 /* fall through - ??? */
2435 tree arg0 = TREE_OPERAND (arg, 0);
2436 tree arg1 = TREE_OPERAND (arg, 1);
2438 /* We need to check both for exact equality and tree equality. The
2439 former will be true if the operand has a side-effect. In that
2440 case, we know the operand occurred exactly once. */
2442 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
2444 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
2447 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
2449 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
2452 return fold (build (code, type, arg0, arg1));
2460 /* Return a tree for the case when the result of an expression is RESULT
2461 converted to TYPE and OMITTED was previously an operand of the expression
2462 but is now not needed (e.g., we folded OMITTED * 0).
2464 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2465 the conversion of RESULT to TYPE. */
2468 omit_one_operand (type, result, omitted)
2469 tree type, result, omitted;
2471 tree t = convert (type, result);
2473 if (TREE_SIDE_EFFECTS (omitted))
2474 return build (COMPOUND_EXPR, type, omitted, t);
2476 return non_lvalue (t);
2479 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2482 pedantic_omit_one_operand (type, result, omitted)
2483 tree type, result, omitted;
2485 tree t = convert (type, result);
2487 if (TREE_SIDE_EFFECTS (omitted))
2488 return build (COMPOUND_EXPR, type, omitted, t);
2490 return pedantic_non_lvalue (t);
2495 /* Return a simplified tree node for the truth-negation of ARG. This
2496 never alters ARG itself. We assume that ARG is an operation that
2497 returns a truth value (0 or 1). */
2500 invert_truthvalue (arg)
2503 tree type = TREE_TYPE (arg);
2504 enum tree_code code = TREE_CODE (arg);
2506 if (code == ERROR_MARK)
2509 /* If this is a comparison, we can simply invert it, except for
2510 floating-point non-equality comparisons, in which case we just
2511 enclose a TRUTH_NOT_EXPR around what we have. */
2513 if (TREE_CODE_CLASS (code) == '<')
2515 if (FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg, 0)))
2516 && !flag_fast_math && code != NE_EXPR && code != EQ_EXPR)
2517 return build1 (TRUTH_NOT_EXPR, type, arg);
2519 return build (invert_tree_comparison (code), type,
2520 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
2526 return convert (type, build_int_2 (TREE_INT_CST_LOW (arg) == 0
2527 && TREE_INT_CST_HIGH (arg) == 0, 0));
2529 case TRUTH_AND_EXPR:
2530 return build (TRUTH_OR_EXPR, type,
2531 invert_truthvalue (TREE_OPERAND (arg, 0)),
2532 invert_truthvalue (TREE_OPERAND (arg, 1)));
2535 return build (TRUTH_AND_EXPR, type,
2536 invert_truthvalue (TREE_OPERAND (arg, 0)),
2537 invert_truthvalue (TREE_OPERAND (arg, 1)));
2539 case TRUTH_XOR_EXPR:
2540 /* Here we can invert either operand. We invert the first operand
2541 unless the second operand is a TRUTH_NOT_EXPR in which case our
2542 result is the XOR of the first operand with the inside of the
2543 negation of the second operand. */
2545 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
2546 return build (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
2547 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
2549 return build (TRUTH_XOR_EXPR, type,
2550 invert_truthvalue (TREE_OPERAND (arg, 0)),
2551 TREE_OPERAND (arg, 1));
2553 case TRUTH_ANDIF_EXPR:
2554 return build (TRUTH_ORIF_EXPR, type,
2555 invert_truthvalue (TREE_OPERAND (arg, 0)),
2556 invert_truthvalue (TREE_OPERAND (arg, 1)));
2558 case TRUTH_ORIF_EXPR:
2559 return build (TRUTH_ANDIF_EXPR, type,
2560 invert_truthvalue (TREE_OPERAND (arg, 0)),
2561 invert_truthvalue (TREE_OPERAND (arg, 1)));
2563 case TRUTH_NOT_EXPR:
2564 return TREE_OPERAND (arg, 0);
2567 return build (COND_EXPR, type, TREE_OPERAND (arg, 0),
2568 invert_truthvalue (TREE_OPERAND (arg, 1)),
2569 invert_truthvalue (TREE_OPERAND (arg, 2)));
2572 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
2573 invert_truthvalue (TREE_OPERAND (arg, 1)));
2575 case NON_LVALUE_EXPR:
2576 return invert_truthvalue (TREE_OPERAND (arg, 0));
2581 return build1 (TREE_CODE (arg), type,
2582 invert_truthvalue (TREE_OPERAND (arg, 0)));
2585 if (!integer_onep (TREE_OPERAND (arg, 1)))
2587 return build (EQ_EXPR, type, arg, convert (type, integer_zero_node));
2590 return build1 (TRUTH_NOT_EXPR, type, arg);
2592 case CLEANUP_POINT_EXPR:
2593 return build1 (CLEANUP_POINT_EXPR, type,
2594 invert_truthvalue (TREE_OPERAND (arg, 0)));
2599 if (TREE_CODE (TREE_TYPE (arg)) != BOOLEAN_TYPE)
2601 return build1 (TRUTH_NOT_EXPR, type, arg);
2604 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
2605 operands are another bit-wise operation with a common input. If so,
2606 distribute the bit operations to save an operation and possibly two if
2607 constants are involved. For example, convert
2608 (A | B) & (A | C) into A | (B & C)
2609 Further simplification will occur if B and C are constants.
2611 If this optimization cannot be done, 0 will be returned. */
2614 distribute_bit_expr (code, type, arg0, arg1)
2615 enum tree_code code;
2622 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2623 || TREE_CODE (arg0) == code
2624 || (TREE_CODE (arg0) != BIT_AND_EXPR
2625 && TREE_CODE (arg0) != BIT_IOR_EXPR))
2628 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
2630 common = TREE_OPERAND (arg0, 0);
2631 left = TREE_OPERAND (arg0, 1);
2632 right = TREE_OPERAND (arg1, 1);
2634 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
2636 common = TREE_OPERAND (arg0, 0);
2637 left = TREE_OPERAND (arg0, 1);
2638 right = TREE_OPERAND (arg1, 0);
2640 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
2642 common = TREE_OPERAND (arg0, 1);
2643 left = TREE_OPERAND (arg0, 0);
2644 right = TREE_OPERAND (arg1, 1);
2646 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
2648 common = TREE_OPERAND (arg0, 1);
2649 left = TREE_OPERAND (arg0, 0);
2650 right = TREE_OPERAND (arg1, 0);
2655 return fold (build (TREE_CODE (arg0), type, common,
2656 fold (build (code, type, left, right))));
2659 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
2660 starting at BITPOS. The field is unsigned if UNSIGNEDP is non-zero. */
2663 make_bit_field_ref (inner, type, bitsize, bitpos, unsignedp)
2666 int bitsize, bitpos;
2669 tree result = build (BIT_FIELD_REF, type, inner,
2670 size_int (bitsize), bitsize_int (bitpos, 0L));
2672 TREE_UNSIGNED (result) = unsignedp;
2677 /* Optimize a bit-field compare.
2679 There are two cases: First is a compare against a constant and the
2680 second is a comparison of two items where the fields are at the same
2681 bit position relative to the start of a chunk (byte, halfword, word)
2682 large enough to contain it. In these cases we can avoid the shift
2683 implicit in bitfield extractions.
2685 For constants, we emit a compare of the shifted constant with the
2686 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
2687 compared. For two fields at the same position, we do the ANDs with the
2688 similar mask and compare the result of the ANDs.
2690 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
2691 COMPARE_TYPE is the type of the comparison, and LHS and RHS
2692 are the left and right operands of the comparison, respectively.
2694 If the optimization described above can be done, we return the resulting
2695 tree. Otherwise we return zero. */
2698 optimize_bit_field_compare (code, compare_type, lhs, rhs)
2699 enum tree_code code;
2703 int lbitpos, lbitsize, rbitpos, rbitsize;
2704 int lnbitpos, lnbitsize, rnbitpos = 0, rnbitsize = 0;
2705 tree type = TREE_TYPE (lhs);
2706 tree signed_type, unsigned_type;
2707 int const_p = TREE_CODE (rhs) == INTEGER_CST;
2708 enum machine_mode lmode, rmode, lnmode, rnmode = VOIDmode;
2709 int lunsignedp, runsignedp;
2710 int lvolatilep = 0, rvolatilep = 0;
2712 tree linner, rinner = NULL_TREE;
2716 /* Get all the information about the extractions being done. If the bit size
2717 if the same as the size of the underlying object, we aren't doing an
2718 extraction at all and so can do nothing. */
2719 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
2720 &lunsignedp, &lvolatilep, &alignment);
2721 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
2727 /* If this is not a constant, we can only do something if bit positions,
2728 sizes, and signedness are the same. */
2729 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
2730 &runsignedp, &rvolatilep, &alignment);
2732 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
2733 || lunsignedp != runsignedp || offset != 0)
2737 /* See if we can find a mode to refer to this field. We should be able to,
2738 but fail if we can't. */
2739 lnmode = get_best_mode (lbitsize, lbitpos,
2740 TYPE_ALIGN (TREE_TYPE (linner)), word_mode,
2742 if (lnmode == VOIDmode)
2745 /* Set signed and unsigned types of the precision of this mode for the
2747 signed_type = type_for_mode (lnmode, 0);
2748 unsigned_type = type_for_mode (lnmode, 1);
2752 rnmode = get_best_mode (rbitsize, rbitpos,
2753 TYPE_ALIGN (TREE_TYPE (rinner)), word_mode,
2755 if (rnmode == VOIDmode)
2759 /* Compute the bit position and size for the new reference and our offset
2760 within it. If the new reference is the same size as the original, we
2761 won't optimize anything, so return zero. */
2762 lnbitsize = GET_MODE_BITSIZE (lnmode);
2763 lnbitpos = lbitpos & ~ (lnbitsize - 1);
2764 lbitpos -= lnbitpos;
2765 if (lnbitsize == lbitsize)
2770 rnbitsize = GET_MODE_BITSIZE (rnmode);
2771 rnbitpos = rbitpos & ~ (rnbitsize - 1);
2772 rbitpos -= rnbitpos;
2773 if (rnbitsize == rbitsize)
2777 if (BYTES_BIG_ENDIAN)
2778 lbitpos = lnbitsize - lbitsize - lbitpos;
2780 /* Make the mask to be used against the extracted field. */
2781 mask = build_int_2 (~0, ~0);
2782 TREE_TYPE (mask) = unsigned_type;
2783 force_fit_type (mask, 0);
2784 mask = convert (unsigned_type, mask);
2785 mask = const_binop (LSHIFT_EXPR, mask, size_int (lnbitsize - lbitsize), 0);
2786 mask = const_binop (RSHIFT_EXPR, mask,
2787 size_int (lnbitsize - lbitsize - lbitpos), 0);
2790 /* If not comparing with constant, just rework the comparison
2792 return build (code, compare_type,
2793 build (BIT_AND_EXPR, unsigned_type,
2794 make_bit_field_ref (linner, unsigned_type,
2795 lnbitsize, lnbitpos, 1),
2797 build (BIT_AND_EXPR, unsigned_type,
2798 make_bit_field_ref (rinner, unsigned_type,
2799 rnbitsize, rnbitpos, 1),
2802 /* Otherwise, we are handling the constant case. See if the constant is too
2803 big for the field. Warn and return a tree of for 0 (false) if so. We do
2804 this not only for its own sake, but to avoid having to test for this
2805 error case below. If we didn't, we might generate wrong code.
2807 For unsigned fields, the constant shifted right by the field length should
2808 be all zero. For signed fields, the high-order bits should agree with
2813 if (! integer_zerop (const_binop (RSHIFT_EXPR,
2814 convert (unsigned_type, rhs),
2815 size_int (lbitsize), 0)))
2817 warning ("comparison is always %d due to width of bitfield",
2819 return convert (compare_type,
2821 ? integer_one_node : integer_zero_node));
2826 tree tem = const_binop (RSHIFT_EXPR, convert (signed_type, rhs),
2827 size_int (lbitsize - 1), 0);
2828 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
2830 warning ("comparison is always %d due to width of bitfield",
2832 return convert (compare_type,
2834 ? integer_one_node : integer_zero_node));
2838 /* Single-bit compares should always be against zero. */
2839 if (lbitsize == 1 && ! integer_zerop (rhs))
2841 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
2842 rhs = convert (type, integer_zero_node);
2845 /* Make a new bitfield reference, shift the constant over the
2846 appropriate number of bits and mask it with the computed mask
2847 (in case this was a signed field). If we changed it, make a new one. */
2848 lhs = make_bit_field_ref (linner, unsigned_type, lnbitsize, lnbitpos, 1);
2851 TREE_SIDE_EFFECTS (lhs) = 1;
2852 TREE_THIS_VOLATILE (lhs) = 1;
2855 rhs = fold (const_binop (BIT_AND_EXPR,
2856 const_binop (LSHIFT_EXPR,
2857 convert (unsigned_type, rhs),
2858 size_int (lbitpos), 0),
2861 return build (code, compare_type,
2862 build (BIT_AND_EXPR, unsigned_type, lhs, mask),
2866 /* Subroutine for fold_truthop: decode a field reference.
2868 If EXP is a comparison reference, we return the innermost reference.
2870 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
2871 set to the starting bit number.
2873 If the innermost field can be completely contained in a mode-sized
2874 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
2876 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
2877 otherwise it is not changed.
2879 *PUNSIGNEDP is set to the signedness of the field.
2881 *PMASK is set to the mask used. This is either contained in a
2882 BIT_AND_EXPR or derived from the width of the field.
2884 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
2886 Return 0 if this is not a component reference or is one that we can't
2887 do anything with. */
2890 decode_field_reference (exp, pbitsize, pbitpos, pmode, punsignedp,
2891 pvolatilep, pmask, pand_mask)
2893 int *pbitsize, *pbitpos;
2894 enum machine_mode *pmode;
2895 int *punsignedp, *pvolatilep;
2900 tree mask, inner, offset;
2905 /* All the optimizations using this function assume integer fields.
2906 There are problems with FP fields since the type_for_size call
2907 below can fail for, e.g., XFmode. */
2908 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
2913 if (TREE_CODE (exp) == BIT_AND_EXPR)
2915 and_mask = TREE_OPERAND (exp, 1);
2916 exp = TREE_OPERAND (exp, 0);
2917 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
2918 if (TREE_CODE (and_mask) != INTEGER_CST)
2923 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
2924 punsignedp, pvolatilep, &alignment);
2925 if ((inner == exp && and_mask == 0)
2926 || *pbitsize < 0 || offset != 0)
2929 /* Compute the mask to access the bitfield. */
2930 unsigned_type = type_for_size (*pbitsize, 1);
2931 precision = TYPE_PRECISION (unsigned_type);
2933 mask = build_int_2 (~0, ~0);
2934 TREE_TYPE (mask) = unsigned_type;
2935 force_fit_type (mask, 0);
2936 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
2937 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
2939 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
2941 mask = fold (build (BIT_AND_EXPR, unsigned_type,
2942 convert (unsigned_type, and_mask), mask));
2945 *pand_mask = and_mask;
2949 /* Return non-zero if MASK represents a mask of SIZE ones in the low-order
2953 all_ones_mask_p (mask, size)
2957 tree type = TREE_TYPE (mask);
2958 int precision = TYPE_PRECISION (type);
2961 tmask = build_int_2 (~0, ~0);
2962 TREE_TYPE (tmask) = signed_type (type);
2963 force_fit_type (tmask, 0);
2965 tree_int_cst_equal (mask,
2966 const_binop (RSHIFT_EXPR,
2967 const_binop (LSHIFT_EXPR, tmask,
2968 size_int (precision - size),
2970 size_int (precision - size), 0));
2973 /* Subroutine for fold_truthop: determine if an operand is simple enough
2974 to be evaluated unconditionally. */
2977 simple_operand_p (exp)
2980 /* Strip any conversions that don't change the machine mode. */
2981 while ((TREE_CODE (exp) == NOP_EXPR
2982 || TREE_CODE (exp) == CONVERT_EXPR)
2983 && (TYPE_MODE (TREE_TYPE (exp))
2984 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)))))
2985 exp = TREE_OPERAND (exp, 0);
2987 return (TREE_CODE_CLASS (TREE_CODE (exp)) == 'c'
2988 || (TREE_CODE_CLASS (TREE_CODE (exp)) == 'd'
2989 && ! TREE_ADDRESSABLE (exp)
2990 && ! TREE_THIS_VOLATILE (exp)
2991 && ! DECL_NONLOCAL (exp)
2992 /* Don't regard global variables as simple. They may be
2993 allocated in ways unknown to the compiler (shared memory,
2994 #pragma weak, etc). */
2995 && ! TREE_PUBLIC (exp)
2996 && ! DECL_EXTERNAL (exp)
2997 /* Loading a static variable is unduly expensive, but global
2998 registers aren't expensive. */
2999 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
3002 /* The following functions are subroutines to fold_range_test and allow it to
3003 try to change a logical combination of comparisons into a range test.
3006 X == 2 && X == 3 && X == 4 && X == 5
3010 (unsigned) (X - 2) <= 3
3012 We describe each set of comparisons as being either inside or outside
3013 a range, using a variable named like IN_P, and then describe the
3014 range with a lower and upper bound. If one of the bounds is omitted,
3015 it represents either the highest or lowest value of the type.
3017 In the comments below, we represent a range by two numbers in brackets
3018 preceded by a "+" to designate being inside that range, or a "-" to
3019 designate being outside that range, so the condition can be inverted by
3020 flipping the prefix. An omitted bound is represented by a "-". For
3021 example, "- [-, 10]" means being outside the range starting at the lowest
3022 possible value and ending at 10, in other words, being greater than 10.
3023 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
3026 We set up things so that the missing bounds are handled in a consistent
3027 manner so neither a missing bound nor "true" and "false" need to be
3028 handled using a special case. */
3030 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
3031 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
3032 and UPPER1_P are nonzero if the respective argument is an upper bound
3033 and zero for a lower. TYPE, if nonzero, is the type of the result; it
3034 must be specified for a comparison. ARG1 will be converted to ARG0's
3035 type if both are specified. */
3038 range_binop (code, type, arg0, upper0_p, arg1, upper1_p)
3039 enum tree_code code;
3042 int upper0_p, upper1_p;
3048 /* If neither arg represents infinity, do the normal operation.
3049 Else, if not a comparison, return infinity. Else handle the special
3050 comparison rules. Note that most of the cases below won't occur, but
3051 are handled for consistency. */
3053 if (arg0 != 0 && arg1 != 0)
3055 tem = fold (build (code, type != 0 ? type : TREE_TYPE (arg0),
3056 arg0, convert (TREE_TYPE (arg0), arg1)));
3058 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
3061 if (TREE_CODE_CLASS (code) != '<')
3064 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
3065 for neither. In real maths, we cannot assume open ended ranges are
3066 the same. But, this is computer arithmetic, where numbers are finite.
3067 We can therefore make the transformation of any unbounded range with
3068 the value Z, Z being greater than any representable number. This permits
3069 us to treat unbounded ranges as equal. */
3070 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
3071 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
3075 result = sgn0 == sgn1;
3078 result = sgn0 != sgn1;
3081 result = sgn0 < sgn1;
3084 result = sgn0 <= sgn1;
3087 result = sgn0 > sgn1;
3090 result = sgn0 >= sgn1;
3096 return convert (type, result ? integer_one_node : integer_zero_node);
3099 /* Given EXP, a logical expression, set the range it is testing into
3100 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
3101 actually being tested. *PLOW and *PHIGH will have be made the same type
3102 as the returned expression. If EXP is not a comparison, we will most
3103 likely not be returning a useful value and range. */
3106 make_range (exp, pin_p, plow, phigh)
3111 enum tree_code code;
3112 tree arg0, arg1, type = NULL_TREE;
3113 tree orig_type = NULL_TREE;
3115 tree low, high, n_low, n_high;
3117 /* Start with simply saying "EXP != 0" and then look at the code of EXP
3118 and see if we can refine the range. Some of the cases below may not
3119 happen, but it doesn't seem worth worrying about this. We "continue"
3120 the outer loop when we've changed something; otherwise we "break"
3121 the switch, which will "break" the while. */
3123 in_p = 0, low = high = convert (TREE_TYPE (exp), integer_zero_node);
3127 code = TREE_CODE (exp);
3129 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
3131 arg0 = TREE_OPERAND (exp, 0);
3132 if (TREE_CODE_CLASS (code) == '<'
3133 || TREE_CODE_CLASS (code) == '1'
3134 || TREE_CODE_CLASS (code) == '2')
3135 type = TREE_TYPE (arg0);
3136 if (TREE_CODE_CLASS (code) == '2'
3137 || TREE_CODE_CLASS (code) == '<'
3138 || (TREE_CODE_CLASS (code) == 'e'
3139 && tree_code_length[(int) code] > 1))
3140 arg1 = TREE_OPERAND (exp, 1);
3145 case TRUTH_NOT_EXPR:
3146 in_p = ! in_p, exp = arg0;
3149 case EQ_EXPR: case NE_EXPR:
3150 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
3151 /* We can only do something if the range is testing for zero
3152 and if the second operand is an integer constant. Note that
3153 saying something is "in" the range we make is done by
3154 complementing IN_P since it will set in the initial case of
3155 being not equal to zero; "out" is leaving it alone. */
3156 if (low == 0 || high == 0
3157 || ! integer_zerop (low) || ! integer_zerop (high)
3158 || TREE_CODE (arg1) != INTEGER_CST)
3163 case NE_EXPR: /* - [c, c] */
3166 case EQ_EXPR: /* + [c, c] */
3167 in_p = ! in_p, low = high = arg1;
3169 case GT_EXPR: /* - [-, c] */
3170 low = 0, high = arg1;
3172 case GE_EXPR: /* + [c, -] */
3173 in_p = ! in_p, low = arg1, high = 0;
3175 case LT_EXPR: /* - [c, -] */
3176 low = arg1, high = 0;
3178 case LE_EXPR: /* + [-, c] */
3179 in_p = ! in_p, low = 0, high = arg1;
3187 /* If this is an unsigned comparison, we also know that EXP is
3188 greater than or equal to zero. We base the range tests we make
3189 on that fact, so we record it here so we can parse existing
3191 if (TREE_UNSIGNED (type) && (low == 0 || high == 0))
3193 if (! merge_ranges (&n_in_p, &n_low, &n_high, in_p, low, high,
3194 1, convert (type, integer_zero_node),
3198 in_p = n_in_p, low = n_low, high = n_high;
3200 /* If the high bound is missing, reverse the range so it
3201 goes from zero to the low bound minus 1. */
3205 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
3206 integer_one_node, 0);
3207 low = convert (type, integer_zero_node);
3213 /* (-x) IN [a,b] -> x in [-b, -a] */
3214 n_low = range_binop (MINUS_EXPR, type,
3215 convert (type, integer_zero_node), 0, high, 1);
3216 n_high = range_binop (MINUS_EXPR, type,
3217 convert (type, integer_zero_node), 0, low, 0);
3218 low = n_low, high = n_high;
3224 exp = build (MINUS_EXPR, type, build1 (NEGATE_EXPR, type, arg0),
3225 convert (type, integer_one_node));
3228 case PLUS_EXPR: case MINUS_EXPR:
3229 if (TREE_CODE (arg1) != INTEGER_CST)
3232 /* If EXP is signed, any overflow in the computation is undefined,
3233 so we don't worry about it so long as our computations on
3234 the bounds don't overflow. For unsigned, overflow is defined
3235 and this is exactly the right thing. */
3236 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3237 type, low, 0, arg1, 0);
3238 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3239 type, high, 1, arg1, 0);
3240 if ((n_low != 0 && TREE_OVERFLOW (n_low))
3241 || (n_high != 0 && TREE_OVERFLOW (n_high)))
3244 /* Check for an unsigned range which has wrapped around the maximum
3245 value thus making n_high < n_low, and normalize it. */
3246 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
3248 low = range_binop (PLUS_EXPR, type, n_high, 0,
3249 integer_one_node, 0);
3250 high = range_binop (MINUS_EXPR, type, n_low, 0,
3251 integer_one_node, 0);
3255 low = n_low, high = n_high;
3260 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
3261 if (orig_type == NULL_TREE)
3263 if (TYPE_PRECISION (type) > TYPE_PRECISION (orig_type))
3266 if (! INTEGRAL_TYPE_P (type)
3267 || (low != 0 && ! int_fits_type_p (low, type))
3268 || (high != 0 && ! int_fits_type_p (high, type)))
3271 n_low = low, n_high = high;
3274 n_low = convert (type, n_low);
3277 n_high = convert (type, n_high);
3279 /* If we're converting from an unsigned to a signed type,
3280 we will be doing the comparison as unsigned. The tests above
3281 have already verified that LOW and HIGH are both positive.
3283 So we have to make sure that the original unsigned value will
3284 be interpreted as positive. */
3285 if (TREE_UNSIGNED (type) && ! TREE_UNSIGNED (TREE_TYPE (exp)))
3287 tree equiv_type = type_for_mode (TYPE_MODE (type), 1);
3290 /* A range without an upper bound is, naturally, unbounded.
3291 Since convert would have cropped a very large value, use
3292 the max value for the destination type. */
3294 high_positive = TYPE_MAX_VALUE (equiv_type);
3297 high_positive = TYPE_MAX_VALUE (type);
3301 high_positive = fold (build (RSHIFT_EXPR, type,
3302 convert (type, high_positive),
3303 convert (type, integer_one_node)));
3305 /* If the low bound is specified, "and" the range with the
3306 range for which the original unsigned value will be
3310 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3312 1, convert (type, integer_zero_node),
3316 in_p = (n_in_p == in_p);
3320 /* Otherwise, "or" the range with the range of the input
3321 that will be interpreted as negative. */
3322 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3324 1, convert (type, integer_zero_node),
3328 in_p = (in_p != n_in_p);
3333 low = n_low, high = n_high;
3343 /* If EXP is a constant, we can evaluate whether this is true or false. */
3344 if (TREE_CODE (exp) == INTEGER_CST)
3346 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
3348 && integer_onep (range_binop (LE_EXPR, integer_type_node,
3354 *pin_p = in_p, *plow = low, *phigh = high;
3358 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3359 type, TYPE, return an expression to test if EXP is in (or out of, depending
3360 on IN_P) the range. */
3363 build_range_check (type, exp, in_p, low, high)
3369 tree etype = TREE_TYPE (exp);
3373 && (0 != (value = build_range_check (type, exp, 1, low, high))))
3374 return invert_truthvalue (value);
3376 else if (low == 0 && high == 0)
3377 return convert (type, integer_one_node);
3380 return fold (build (LE_EXPR, type, exp, high));
3383 return fold (build (GE_EXPR, type, exp, low));
3385 else if (operand_equal_p (low, high, 0))
3386 return fold (build (EQ_EXPR, type, exp, low));
3388 else if (TREE_UNSIGNED (etype) && integer_zerop (low))
3389 return build_range_check (type, exp, 1, 0, high);
3391 else if (integer_zerop (low))
3393 utype = unsigned_type (etype);
3394 return build_range_check (type, convert (utype, exp), 1, 0,
3395 convert (utype, high));
3398 else if (0 != (value = const_binop (MINUS_EXPR, high, low, 0))
3399 && ! TREE_OVERFLOW (value))
3400 return build_range_check (type,
3401 fold (build (MINUS_EXPR, etype, exp, low)),
3402 1, convert (etype, integer_zero_node), value);
3407 /* Given two ranges, see if we can merge them into one. Return 1 if we
3408 can, 0 if we can't. Set the output range into the specified parameters. */
3411 merge_ranges (pin_p, plow, phigh, in0_p, low0, high0, in1_p, low1, high1)
3415 tree low0, high0, low1, high1;
3423 int lowequal = ((low0 == 0 && low1 == 0)
3424 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3425 low0, 0, low1, 0)));
3426 int highequal = ((high0 == 0 && high1 == 0)
3427 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3428 high0, 1, high1, 1)));
3430 /* Make range 0 be the range that starts first, or ends last if they
3431 start at the same value. Swap them if it isn't. */
3432 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
3435 && integer_onep (range_binop (GT_EXPR, integer_type_node,
3436 high1, 1, high0, 1))))
3438 temp = in0_p, in0_p = in1_p, in1_p = temp;
3439 tem = low0, low0 = low1, low1 = tem;
3440 tem = high0, high0 = high1, high1 = tem;
3443 /* Now flag two cases, whether the ranges are disjoint or whether the
3444 second range is totally subsumed in the first. Note that the tests
3445 below are simplified by the ones above. */
3446 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
3447 high0, 1, low1, 0));
3448 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
3449 high1, 1, high0, 1));
3451 /* We now have four cases, depending on whether we are including or
3452 excluding the two ranges. */
3455 /* If they don't overlap, the result is false. If the second range
3456 is a subset it is the result. Otherwise, the range is from the start
3457 of the second to the end of the first. */
3459 in_p = 0, low = high = 0;
3461 in_p = 1, low = low1, high = high1;
3463 in_p = 1, low = low1, high = high0;
3466 else if (in0_p && ! in1_p)
3468 /* If they don't overlap, the result is the first range. If they are
3469 equal, the result is false. If the second range is a subset of the
3470 first, and the ranges begin at the same place, we go from just after
3471 the end of the first range to the end of the second. If the second
3472 range is not a subset of the first, or if it is a subset and both
3473 ranges end at the same place, the range starts at the start of the
3474 first range and ends just before the second range.
3475 Otherwise, we can't describe this as a single range. */
3477 in_p = 1, low = low0, high = high0;
3478 else if (lowequal && highequal)
3479 in_p = 0, low = high = 0;
3480 else if (subset && lowequal)
3482 in_p = 1, high = high0;
3483 low = range_binop (PLUS_EXPR, NULL_TREE, high1, 0,
3484 integer_one_node, 0);
3486 else if (! subset || highequal)
3488 in_p = 1, low = low0;
3489 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
3490 integer_one_node, 0);
3496 else if (! in0_p && in1_p)
3498 /* If they don't overlap, the result is the second range. If the second
3499 is a subset of the first, the result is false. Otherwise,
3500 the range starts just after the first range and ends at the
3501 end of the second. */
3503 in_p = 1, low = low1, high = high1;
3505 in_p = 0, low = high = 0;
3508 in_p = 1, high = high1;
3509 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
3510 integer_one_node, 0);
3516 /* The case where we are excluding both ranges. Here the complex case
3517 is if they don't overlap. In that case, the only time we have a
3518 range is if they are adjacent. If the second is a subset of the
3519 first, the result is the first. Otherwise, the range to exclude
3520 starts at the beginning of the first range and ends at the end of the
3524 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
3525 range_binop (PLUS_EXPR, NULL_TREE,
3527 integer_one_node, 1),
3529 in_p = 0, low = low0, high = high1;
3534 in_p = 0, low = low0, high = high0;
3536 in_p = 0, low = low0, high = high1;
3539 *pin_p = in_p, *plow = low, *phigh = high;
3543 /* EXP is some logical combination of boolean tests. See if we can
3544 merge it into some range test. Return the new tree if so. */
3547 fold_range_test (exp)
3550 int or_op = (TREE_CODE (exp) == TRUTH_ORIF_EXPR
3551 || TREE_CODE (exp) == TRUTH_OR_EXPR);
3552 int in0_p, in1_p, in_p;
3553 tree low0, low1, low, high0, high1, high;
3554 tree lhs = make_range (TREE_OPERAND (exp, 0), &in0_p, &low0, &high0);
3555 tree rhs = make_range (TREE_OPERAND (exp, 1), &in1_p, &low1, &high1);
3558 /* If this is an OR operation, invert both sides; we will invert
3559 again at the end. */
3561 in0_p = ! in0_p, in1_p = ! in1_p;
3563 /* If both expressions are the same, if we can merge the ranges, and we
3564 can build the range test, return it or it inverted. If one of the
3565 ranges is always true or always false, consider it to be the same
3566 expression as the other. */
3567 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
3568 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
3570 && 0 != (tem = (build_range_check (TREE_TYPE (exp),
3572 : rhs != 0 ? rhs : integer_zero_node,
3574 return or_op ? invert_truthvalue (tem) : tem;
3576 /* On machines where the branch cost is expensive, if this is a
3577 short-circuited branch and the underlying object on both sides
3578 is the same, make a non-short-circuit operation. */
3579 else if (BRANCH_COST >= 2
3580 && (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3581 || TREE_CODE (exp) == TRUTH_ORIF_EXPR)
3582 && operand_equal_p (lhs, rhs, 0))
3584 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
3585 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
3586 which cases we can't do this. */
3587 if (simple_operand_p (lhs))
3588 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3589 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3590 TREE_TYPE (exp), TREE_OPERAND (exp, 0),
3591 TREE_OPERAND (exp, 1));
3593 else if (current_function_decl != 0
3594 && ! contains_placeholder_p (lhs))
3596 tree common = save_expr (lhs);
3598 if (0 != (lhs = build_range_check (TREE_TYPE (exp), common,
3599 or_op ? ! in0_p : in0_p,
3601 && (0 != (rhs = build_range_check (TREE_TYPE (exp), common,
3602 or_op ? ! in1_p : in1_p,
3604 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3605 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3606 TREE_TYPE (exp), lhs, rhs);
3613 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
3614 bit value. Arrange things so the extra bits will be set to zero if and
3615 only if C is signed-extended to its full width. If MASK is nonzero,
3616 it is an INTEGER_CST that should be AND'ed with the extra bits. */
3619 unextend (c, p, unsignedp, mask)
3625 tree type = TREE_TYPE (c);
3626 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
3629 if (p == modesize || unsignedp)
3632 /* We work by getting just the sign bit into the low-order bit, then
3633 into the high-order bit, then sign-extend. We then XOR that value
3635 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
3636 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
3638 /* We must use a signed type in order to get an arithmetic right shift.
3639 However, we must also avoid introducing accidental overflows, so that
3640 a subsequent call to integer_zerop will work. Hence we must
3641 do the type conversion here. At this point, the constant is either
3642 zero or one, and the conversion to a signed type can never overflow.
3643 We could get an overflow if this conversion is done anywhere else. */
3644 if (TREE_UNSIGNED (type))
3645 temp = convert (signed_type (type), temp);
3647 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
3648 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
3650 temp = const_binop (BIT_AND_EXPR, temp, convert (TREE_TYPE (c), mask), 0);
3651 /* If necessary, convert the type back to match the type of C. */
3652 if (TREE_UNSIGNED (type))
3653 temp = convert (type, temp);
3655 return convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
3658 /* Find ways of folding logical expressions of LHS and RHS:
3659 Try to merge two comparisons to the same innermost item.
3660 Look for range tests like "ch >= '0' && ch <= '9'".
3661 Look for combinations of simple terms on machines with expensive branches
3662 and evaluate the RHS unconditionally.
3664 For example, if we have p->a == 2 && p->b == 4 and we can make an
3665 object large enough to span both A and B, we can do this with a comparison
3666 against the object ANDed with the a mask.
3668 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
3669 operations to do this with one comparison.
3671 We check for both normal comparisons and the BIT_AND_EXPRs made this by
3672 function and the one above.
3674 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
3675 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
3677 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
3680 We return the simplified tree or 0 if no optimization is possible. */
3683 fold_truthop (code, truth_type, lhs, rhs)
3684 enum tree_code code;
3685 tree truth_type, lhs, rhs;
3687 /* If this is the "or" of two comparisons, we can do something if we
3688 the comparisons are NE_EXPR. If this is the "and", we can do something
3689 if the comparisons are EQ_EXPR. I.e.,
3690 (a->b == 2 && a->c == 4) can become (a->new == NEW).
3692 WANTED_CODE is this operation code. For single bit fields, we can
3693 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
3694 comparison for one-bit fields. */
3696 enum tree_code wanted_code;
3697 enum tree_code lcode, rcode;
3698 tree ll_arg, lr_arg, rl_arg, rr_arg;
3699 tree ll_inner, lr_inner, rl_inner, rr_inner;
3700 int ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
3701 int rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
3702 int xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
3703 int lnbitsize, lnbitpos, rnbitsize, rnbitpos;
3704 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
3705 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
3706 enum machine_mode lnmode, rnmode;
3707 tree ll_mask, lr_mask, rl_mask, rr_mask;
3708 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
3709 tree l_const, r_const;
3711 int first_bit, end_bit;
3714 /* Start by getting the comparison codes. Fail if anything is volatile.
3715 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
3716 it were surrounded with a NE_EXPR. */
3718 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
3721 lcode = TREE_CODE (lhs);
3722 rcode = TREE_CODE (rhs);
3724 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
3725 lcode = NE_EXPR, lhs = build (NE_EXPR, truth_type, lhs, integer_zero_node);
3727 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
3728 rcode = NE_EXPR, rhs = build (NE_EXPR, truth_type, rhs, integer_zero_node);
3730 if (TREE_CODE_CLASS (lcode) != '<' || TREE_CODE_CLASS (rcode) != '<')
3733 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
3734 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
3736 ll_arg = TREE_OPERAND (lhs, 0);
3737 lr_arg = TREE_OPERAND (lhs, 1);
3738 rl_arg = TREE_OPERAND (rhs, 0);
3739 rr_arg = TREE_OPERAND (rhs, 1);
3741 /* If the RHS can be evaluated unconditionally and its operands are
3742 simple, it wins to evaluate the RHS unconditionally on machines
3743 with expensive branches. In this case, this isn't a comparison
3744 that can be merged. */
3746 /* @@ I'm not sure it wins on the m88110 to do this if the comparisons
3747 are with zero (tmw). */
3749 if (BRANCH_COST >= 2
3750 && INTEGRAL_TYPE_P (TREE_TYPE (rhs))
3751 && simple_operand_p (rl_arg)
3752 && simple_operand_p (rr_arg))
3753 return build (code, truth_type, lhs, rhs);
3755 /* See if the comparisons can be merged. Then get all the parameters for
3758 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
3759 || (rcode != EQ_EXPR && rcode != NE_EXPR))
3763 ll_inner = decode_field_reference (ll_arg,
3764 &ll_bitsize, &ll_bitpos, &ll_mode,
3765 &ll_unsignedp, &volatilep, &ll_mask,
3767 lr_inner = decode_field_reference (lr_arg,
3768 &lr_bitsize, &lr_bitpos, &lr_mode,
3769 &lr_unsignedp, &volatilep, &lr_mask,
3771 rl_inner = decode_field_reference (rl_arg,
3772 &rl_bitsize, &rl_bitpos, &rl_mode,
3773 &rl_unsignedp, &volatilep, &rl_mask,
3775 rr_inner = decode_field_reference (rr_arg,
3776 &rr_bitsize, &rr_bitpos, &rr_mode,
3777 &rr_unsignedp, &volatilep, &rr_mask,
3780 /* It must be true that the inner operation on the lhs of each
3781 comparison must be the same if we are to be able to do anything.
3782 Then see if we have constants. If not, the same must be true for
3784 if (volatilep || ll_inner == 0 || rl_inner == 0
3785 || ! operand_equal_p (ll_inner, rl_inner, 0))
3788 if (TREE_CODE (lr_arg) == INTEGER_CST
3789 && TREE_CODE (rr_arg) == INTEGER_CST)
3790 l_const = lr_arg, r_const = rr_arg;
3791 else if (lr_inner == 0 || rr_inner == 0
3792 || ! operand_equal_p (lr_inner, rr_inner, 0))
3795 l_const = r_const = 0;
3797 /* If either comparison code is not correct for our logical operation,
3798 fail. However, we can convert a one-bit comparison against zero into
3799 the opposite comparison against that bit being set in the field. */
3801 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
3802 if (lcode != wanted_code)
3804 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
3806 if (ll_unsignedp || tree_log2 (ll_mask) + 1 < ll_bitsize)
3809 /* Since ll_arg is a single bit bit mask, we can sign extend
3810 it appropriately with a NEGATE_EXPR.
3811 l_const is made a signed value here, but since for l_const != NULL
3812 lr_unsignedp is not used, we don't need to clear the latter. */
3813 l_const = fold (build1 (NEGATE_EXPR, TREE_TYPE (ll_arg),
3814 convert (TREE_TYPE (ll_arg), ll_mask)));
3820 if (rcode != wanted_code)
3822 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
3824 if (rl_unsignedp || tree_log2 (rl_mask) + 1 < rl_bitsize)
3827 /* This is analogous to the code for l_const above. */
3828 r_const = fold (build1 (NEGATE_EXPR, TREE_TYPE (rl_arg),
3829 convert (TREE_TYPE (rl_arg), rl_mask)));
3835 /* See if we can find a mode that contains both fields being compared on
3836 the left. If we can't, fail. Otherwise, update all constants and masks
3837 to be relative to a field of that size. */
3838 first_bit = MIN (ll_bitpos, rl_bitpos);
3839 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
3840 lnmode = get_best_mode (end_bit - first_bit, first_bit,
3841 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
3843 if (lnmode == VOIDmode)
3846 lnbitsize = GET_MODE_BITSIZE (lnmode);
3847 lnbitpos = first_bit & ~ (lnbitsize - 1);
3848 type = type_for_size (lnbitsize, 1);
3849 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
3851 if (BYTES_BIG_ENDIAN)
3853 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
3854 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
3857 ll_mask = const_binop (LSHIFT_EXPR, convert (type, ll_mask),
3858 size_int (xll_bitpos), 0);
3859 rl_mask = const_binop (LSHIFT_EXPR, convert (type, rl_mask),
3860 size_int (xrl_bitpos), 0);
3864 l_const = convert (type, l_const);
3865 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
3866 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
3867 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
3868 fold (build1 (BIT_NOT_EXPR,
3872 warning ("comparison is always %d", wanted_code == NE_EXPR);
3874 return convert (truth_type,
3875 wanted_code == NE_EXPR
3876 ? integer_one_node : integer_zero_node);
3881 r_const = convert (type, r_const);
3882 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
3883 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
3884 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
3885 fold (build1 (BIT_NOT_EXPR,
3889 warning ("comparison is always %d", wanted_code == NE_EXPR);
3891 return convert (truth_type,
3892 wanted_code == NE_EXPR
3893 ? integer_one_node : integer_zero_node);
3897 /* If the right sides are not constant, do the same for it. Also,
3898 disallow this optimization if a size or signedness mismatch occurs
3899 between the left and right sides. */
3902 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
3903 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
3904 /* Make sure the two fields on the right
3905 correspond to the left without being swapped. */
3906 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
3909 first_bit = MIN (lr_bitpos, rr_bitpos);
3910 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
3911 rnmode = get_best_mode (end_bit - first_bit, first_bit,
3912 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
3914 if (rnmode == VOIDmode)
3917 rnbitsize = GET_MODE_BITSIZE (rnmode);
3918 rnbitpos = first_bit & ~ (rnbitsize - 1);
3919 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
3921 if (BYTES_BIG_ENDIAN)
3923 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
3924 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
3927 lr_mask = const_binop (LSHIFT_EXPR, convert (type, lr_mask),
3928 size_int (xlr_bitpos), 0);
3929 rr_mask = const_binop (LSHIFT_EXPR, convert (type, rr_mask),
3930 size_int (xrr_bitpos), 0);
3932 /* Make a mask that corresponds to both fields being compared.
3933 Do this for both items being compared. If the masks agree,
3934 we can do this by masking both and comparing the masked
3936 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
3937 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
3938 if (operand_equal_p (ll_mask, lr_mask, 0) && lnbitsize == rnbitsize)
3940 lhs = make_bit_field_ref (ll_inner, type, lnbitsize, lnbitpos,
3941 ll_unsignedp || rl_unsignedp);
3942 rhs = make_bit_field_ref (lr_inner, type, rnbitsize, rnbitpos,
3943 lr_unsignedp || rr_unsignedp);
3944 if (! all_ones_mask_p (ll_mask, lnbitsize))
3946 lhs = build (BIT_AND_EXPR, type, lhs, ll_mask);
3947 rhs = build (BIT_AND_EXPR, type, rhs, ll_mask);
3949 return build (wanted_code, truth_type, lhs, rhs);
3952 /* There is still another way we can do something: If both pairs of
3953 fields being compared are adjacent, we may be able to make a wider
3954 field containing them both. */
3955 if ((ll_bitsize + ll_bitpos == rl_bitpos
3956 && lr_bitsize + lr_bitpos == rr_bitpos)
3957 || (ll_bitpos == rl_bitpos + rl_bitsize
3958 && lr_bitpos == rr_bitpos + rr_bitsize))
3959 return build (wanted_code, truth_type,
3960 make_bit_field_ref (ll_inner, type,
3961 ll_bitsize + rl_bitsize,
3962 MIN (ll_bitpos, rl_bitpos),
3964 make_bit_field_ref (lr_inner, type,
3965 lr_bitsize + rr_bitsize,
3966 MIN (lr_bitpos, rr_bitpos),
3972 /* Handle the case of comparisons with constants. If there is something in
3973 common between the masks, those bits of the constants must be the same.
3974 If not, the condition is always false. Test for this to avoid generating
3975 incorrect code below. */
3976 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
3977 if (! integer_zerop (result)
3978 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
3979 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
3981 if (wanted_code == NE_EXPR)
3983 warning ("`or' of unmatched not-equal tests is always 1");
3984 return convert (truth_type, integer_one_node);
3988 warning ("`and' of mutually exclusive equal-tests is always 0");
3989 return convert (truth_type, integer_zero_node);
3993 /* Construct the expression we will return. First get the component
3994 reference we will make. Unless the mask is all ones the width of
3995 that field, perform the mask operation. Then compare with the
3997 result = make_bit_field_ref (ll_inner, type, lnbitsize, lnbitpos,
3998 ll_unsignedp || rl_unsignedp);
4000 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4001 if (! all_ones_mask_p (ll_mask, lnbitsize))
4002 result = build (BIT_AND_EXPR, type, result, ll_mask);
4004 return build (wanted_code, truth_type, result,
4005 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
4008 /* If T contains a COMPOUND_EXPR which was inserted merely to evaluate
4009 S, a SAVE_EXPR, return the expression actually being evaluated. Note
4010 that we may sometimes modify the tree. */
4013 strip_compound_expr (t, s)
4017 enum tree_code code = TREE_CODE (t);
4019 /* See if this is the COMPOUND_EXPR we want to eliminate. */
4020 if (code == COMPOUND_EXPR && TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR
4021 && TREE_OPERAND (TREE_OPERAND (t, 0), 0) == s)
4022 return TREE_OPERAND (t, 1);
4024 /* See if this is a COND_EXPR or a simple arithmetic operator. We
4025 don't bother handling any other types. */
4026 else if (code == COND_EXPR)
4028 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4029 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4030 TREE_OPERAND (t, 2) = strip_compound_expr (TREE_OPERAND (t, 2), s);
4032 else if (TREE_CODE_CLASS (code) == '1')
4033 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4034 else if (TREE_CODE_CLASS (code) == '<'
4035 || TREE_CODE_CLASS (code) == '2')
4037 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4038 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4044 /* Return a node which has the indicated constant VALUE (either 0 or
4045 1), and is of the indicated TYPE. */
4048 constant_boolean_node (value, type)
4052 if (type == integer_type_node)
4053 return value ? integer_one_node : integer_zero_node;
4054 else if (TREE_CODE (type) == BOOLEAN_TYPE)
4055 return truthvalue_conversion (value ? integer_one_node :
4059 tree t = build_int_2 (value, 0);
4060 TREE_TYPE (t) = type;
4065 /* Utility function for the following routine, to see how complex a nesting of
4066 COND_EXPRs can be. EXPR is the expression and LIMIT is a count beyond which
4067 we don't care (to avoid spending too much time on complex expressions.). */
4070 count_cond (expr, lim)
4076 if (TREE_CODE (expr) != COND_EXPR)
4081 true = count_cond (TREE_OPERAND (expr, 1), lim - 1);
4082 false = count_cond (TREE_OPERAND (expr, 2), lim - 1 - true);
4083 return MIN (lim, 1 + true + false);
4086 /* Perform constant folding and related simplification of EXPR.
4087 The related simplifications include x*1 => x, x*0 => 0, etc.,
4088 and application of the associative law.
4089 NOP_EXPR conversions may be removed freely (as long as we
4090 are careful not to change the C type of the overall expression)
4091 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
4092 but we can constant-fold them if they have constant operands. */
4098 register tree t = expr;
4099 tree t1 = NULL_TREE;
4101 tree type = TREE_TYPE (expr);
4102 register tree arg0 = NULL_TREE, arg1 = NULL_TREE;
4103 register enum tree_code code = TREE_CODE (t);
4107 /* WINS will be nonzero when the switch is done
4108 if all operands are constant. */
4112 /* Don't try to process an RTL_EXPR since its operands aren't trees.
4113 Likewise for a SAVE_EXPR that's already been evaluated. */
4114 if (code == RTL_EXPR || (code == SAVE_EXPR && SAVE_EXPR_RTL (t)) != 0)
4117 /* Return right away if already constant. */
4118 if (TREE_CONSTANT (t))
4120 if (code == CONST_DECL)
4121 return DECL_INITIAL (t);
4125 #ifdef MAX_INTEGER_COMPUTATION_MODE
4126 check_max_integer_computation_mode (expr);
4129 kind = TREE_CODE_CLASS (code);
4130 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
4134 /* Special case for conversion ops that can have fixed point args. */
4135 arg0 = TREE_OPERAND (t, 0);
4137 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
4139 STRIP_TYPE_NOPS (arg0);
4141 if (arg0 != 0 && TREE_CODE (arg0) == COMPLEX_CST)
4142 subop = TREE_REALPART (arg0);
4146 if (subop != 0 && TREE_CODE (subop) != INTEGER_CST
4147 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
4148 && TREE_CODE (subop) != REAL_CST
4149 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
4151 /* Note that TREE_CONSTANT isn't enough:
4152 static var addresses are constant but we can't
4153 do arithmetic on them. */
4156 else if (kind == 'e' || kind == '<'
4157 || kind == '1' || kind == '2' || kind == 'r')
4159 register int len = tree_code_length[(int) code];
4161 for (i = 0; i < len; i++)
4163 tree op = TREE_OPERAND (t, i);
4167 continue; /* Valid for CALL_EXPR, at least. */
4169 if (kind == '<' || code == RSHIFT_EXPR)
4171 /* Signedness matters here. Perhaps we can refine this
4173 STRIP_TYPE_NOPS (op);
4177 /* Strip any conversions that don't change the mode. */
4181 if (TREE_CODE (op) == COMPLEX_CST)
4182 subop = TREE_REALPART (op);
4186 if (TREE_CODE (subop) != INTEGER_CST
4187 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
4188 && TREE_CODE (subop) != REAL_CST
4189 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
4191 /* Note that TREE_CONSTANT isn't enough:
4192 static var addresses are constant but we can't
4193 do arithmetic on them. */
4203 /* If this is a commutative operation, and ARG0 is a constant, move it
4204 to ARG1 to reduce the number of tests below. */
4205 if ((code == PLUS_EXPR || code == MULT_EXPR || code == MIN_EXPR
4206 || code == MAX_EXPR || code == BIT_IOR_EXPR || code == BIT_XOR_EXPR
4207 || code == BIT_AND_EXPR)
4208 && (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST))
4210 tem = arg0; arg0 = arg1; arg1 = tem;
4212 tem = TREE_OPERAND (t, 0); TREE_OPERAND (t, 0) = TREE_OPERAND (t, 1);
4213 TREE_OPERAND (t, 1) = tem;
4216 /* Now WINS is set as described above,
4217 ARG0 is the first operand of EXPR,
4218 and ARG1 is the second operand (if it has more than one operand).
4220 First check for cases where an arithmetic operation is applied to a
4221 compound, conditional, or comparison operation. Push the arithmetic
4222 operation inside the compound or conditional to see if any folding
4223 can then be done. Convert comparison to conditional for this purpose.
4224 The also optimizes non-constant cases that used to be done in
4227 Before we do that, see if this is a BIT_AND_EXPR or a BIT_OR_EXPR,
4228 one of the operands is a comparison and the other is a comparison, a
4229 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
4230 code below would make the expression more complex. Change it to a
4231 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
4232 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
4234 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
4235 || code == EQ_EXPR || code == NE_EXPR)
4236 && ((truth_value_p (TREE_CODE (arg0))
4237 && (truth_value_p (TREE_CODE (arg1))
4238 || (TREE_CODE (arg1) == BIT_AND_EXPR
4239 && integer_onep (TREE_OPERAND (arg1, 1)))))
4240 || (truth_value_p (TREE_CODE (arg1))
4241 && (truth_value_p (TREE_CODE (arg0))
4242 || (TREE_CODE (arg0) == BIT_AND_EXPR
4243 && integer_onep (TREE_OPERAND (arg0, 1)))))))
4245 t = fold (build (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
4246 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
4250 if (code == EQ_EXPR)
4251 t = invert_truthvalue (t);
4256 if (TREE_CODE_CLASS (code) == '1')
4258 if (TREE_CODE (arg0) == COMPOUND_EXPR)
4259 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
4260 fold (build1 (code, type, TREE_OPERAND (arg0, 1))));
4261 else if (TREE_CODE (arg0) == COND_EXPR)
4263 t = fold (build (COND_EXPR, type, TREE_OPERAND (arg0, 0),
4264 fold (build1 (code, type, TREE_OPERAND (arg0, 1))),
4265 fold (build1 (code, type, TREE_OPERAND (arg0, 2)))));
4267 /* If this was a conversion, and all we did was to move into
4268 inside the COND_EXPR, bring it back out. But leave it if
4269 it is a conversion from integer to integer and the
4270 result precision is no wider than a word since such a
4271 conversion is cheap and may be optimized away by combine,
4272 while it couldn't if it were outside the COND_EXPR. Then return
4273 so we don't get into an infinite recursion loop taking the
4274 conversion out and then back in. */
4276 if ((code == NOP_EXPR || code == CONVERT_EXPR
4277 || code == NON_LVALUE_EXPR)
4278 && TREE_CODE (t) == COND_EXPR
4279 && TREE_CODE (TREE_OPERAND (t, 1)) == code
4280 && TREE_CODE (TREE_OPERAND (t, 2)) == code
4281 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))
4282 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 2), 0)))
4283 && ! (INTEGRAL_TYPE_P (TREE_TYPE (t))
4284 && INTEGRAL_TYPE_P (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0)))
4285 && TYPE_PRECISION (TREE_TYPE (t)) <= BITS_PER_WORD))
4286 t = build1 (code, type,
4288 TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0)),
4289 TREE_OPERAND (t, 0),
4290 TREE_OPERAND (TREE_OPERAND (t, 1), 0),
4291 TREE_OPERAND (TREE_OPERAND (t, 2), 0)));
4294 else if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<')
4295 return fold (build (COND_EXPR, type, arg0,
4296 fold (build1 (code, type, integer_one_node)),
4297 fold (build1 (code, type, integer_zero_node))));
4299 else if (TREE_CODE_CLASS (code) == '2'
4300 || TREE_CODE_CLASS (code) == '<')
4302 if (TREE_CODE (arg1) == COMPOUND_EXPR)
4303 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
4304 fold (build (code, type,
4305 arg0, TREE_OPERAND (arg1, 1))));
4306 else if ((TREE_CODE (arg1) == COND_EXPR
4307 || (TREE_CODE_CLASS (TREE_CODE (arg1)) == '<'
4308 && TREE_CODE_CLASS (code) != '<'))
4309 && (TREE_CODE (arg0) != COND_EXPR
4310 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
4311 && (! TREE_SIDE_EFFECTS (arg0)
4312 || (current_function_decl != 0
4313 && ! contains_placeholder_p (arg0))))
4315 tree test, true_value, false_value;
4316 tree lhs = 0, rhs = 0;
4318 if (TREE_CODE (arg1) == COND_EXPR)
4320 test = TREE_OPERAND (arg1, 0);
4321 true_value = TREE_OPERAND (arg1, 1);
4322 false_value = TREE_OPERAND (arg1, 2);
4326 tree testtype = TREE_TYPE (arg1);
4328 true_value = convert (testtype, integer_one_node);
4329 false_value = convert (testtype, integer_zero_node);
4332 /* If ARG0 is complex we want to make sure we only evaluate
4333 it once. Though this is only required if it is volatile, it
4334 might be more efficient even if it is not. However, if we
4335 succeed in folding one part to a constant, we do not need
4336 to make this SAVE_EXPR. Since we do this optimization
4337 primarily to see if we do end up with constant and this
4338 SAVE_EXPR interferes with later optimizations, suppressing
4339 it when we can is important.
4341 If we are not in a function, we can't make a SAVE_EXPR, so don't
4342 try to do so. Don't try to see if the result is a constant
4343 if an arm is a COND_EXPR since we get exponential behavior
4346 if (TREE_CODE (arg0) != SAVE_EXPR && ! TREE_CONSTANT (arg0)
4347 && current_function_decl != 0
4348 && ((TREE_CODE (arg0) != VAR_DECL
4349 && TREE_CODE (arg0) != PARM_DECL)
4350 || TREE_SIDE_EFFECTS (arg0)))
4352 if (TREE_CODE (true_value) != COND_EXPR)
4353 lhs = fold (build (code, type, arg0, true_value));
4355 if (TREE_CODE (false_value) != COND_EXPR)
4356 rhs = fold (build (code, type, arg0, false_value));
4358 if ((lhs == 0 || ! TREE_CONSTANT (lhs))
4359 && (rhs == 0 || !TREE_CONSTANT (rhs)))
4360 arg0 = save_expr (arg0), lhs = rhs = 0;
4364 lhs = fold (build (code, type, arg0, true_value));
4366 rhs = fold (build (code, type, arg0, false_value));
4368 test = fold (build (COND_EXPR, type, test, lhs, rhs));
4370 if (TREE_CODE (arg0) == SAVE_EXPR)
4371 return build (COMPOUND_EXPR, type,
4372 convert (void_type_node, arg0),
4373 strip_compound_expr (test, arg0));
4375 return convert (type, test);
4378 else if (TREE_CODE (arg0) == COMPOUND_EXPR)
4379 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
4380 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
4381 else if ((TREE_CODE (arg0) == COND_EXPR
4382 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
4383 && TREE_CODE_CLASS (code) != '<'))
4384 && (TREE_CODE (arg1) != COND_EXPR
4385 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
4386 && (! TREE_SIDE_EFFECTS (arg1)
4387 || (current_function_decl != 0
4388 && ! contains_placeholder_p (arg1))))
4390 tree test, true_value, false_value;
4391 tree lhs = 0, rhs = 0;
4393 if (TREE_CODE (arg0) == COND_EXPR)
4395 test = TREE_OPERAND (arg0, 0);
4396 true_value = TREE_OPERAND (arg0, 1);
4397 false_value = TREE_OPERAND (arg0, 2);
4401 tree testtype = TREE_TYPE (arg0);
4403 true_value = convert (testtype, integer_one_node);
4404 false_value = convert (testtype, integer_zero_node);
4407 if (TREE_CODE (arg1) != SAVE_EXPR && ! TREE_CONSTANT (arg0)
4408 && current_function_decl != 0
4409 && ((TREE_CODE (arg1) != VAR_DECL
4410 && TREE_CODE (arg1) != PARM_DECL)
4411 || TREE_SIDE_EFFECTS (arg1)))
4413 if (TREE_CODE (true_value) != COND_EXPR)
4414 lhs = fold (build (code, type, true_value, arg1));
4416 if (TREE_CODE (false_value) != COND_EXPR)
4417 rhs = fold (build (code, type, false_value, arg1));
4419 if ((lhs == 0 || ! TREE_CONSTANT (lhs))
4420 && (rhs == 0 || !TREE_CONSTANT (rhs)))
4421 arg1 = save_expr (arg1), lhs = rhs = 0;
4425 lhs = fold (build (code, type, true_value, arg1));
4428 rhs = fold (build (code, type, false_value, arg1));
4430 test = fold (build (COND_EXPR, type, test, lhs, rhs));
4431 if (TREE_CODE (arg1) == SAVE_EXPR)
4432 return build (COMPOUND_EXPR, type,
4433 convert (void_type_node, arg1),
4434 strip_compound_expr (test, arg1));
4436 return convert (type, test);
4439 else if (TREE_CODE_CLASS (code) == '<'
4440 && TREE_CODE (arg0) == COMPOUND_EXPR)
4441 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
4442 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
4443 else if (TREE_CODE_CLASS (code) == '<'
4444 && TREE_CODE (arg1) == COMPOUND_EXPR)
4445 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
4446 fold (build (code, type, arg0, TREE_OPERAND (arg1, 1))));
4458 return fold (DECL_INITIAL (t));
4463 case FIX_TRUNC_EXPR:
4464 /* Other kinds of FIX are not handled properly by fold_convert. */
4466 if (TREE_TYPE (TREE_OPERAND (t, 0)) == TREE_TYPE (t))
4467 return TREE_OPERAND (t, 0);
4469 /* Handle cases of two conversions in a row. */
4470 if (TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
4471 || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR)
4473 tree inside_type = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
4474 tree inter_type = TREE_TYPE (TREE_OPERAND (t, 0));
4475 tree final_type = TREE_TYPE (t);
4476 int inside_int = INTEGRAL_TYPE_P (inside_type);
4477 int inside_ptr = POINTER_TYPE_P (inside_type);
4478 int inside_float = FLOAT_TYPE_P (inside_type);
4479 int inside_prec = TYPE_PRECISION (inside_type);
4480 int inside_unsignedp = TREE_UNSIGNED (inside_type);
4481 int inter_int = INTEGRAL_TYPE_P (inter_type);
4482 int inter_ptr = POINTER_TYPE_P (inter_type);
4483 int inter_float = FLOAT_TYPE_P (inter_type);
4484 int inter_prec = TYPE_PRECISION (inter_type);
4485 int inter_unsignedp = TREE_UNSIGNED (inter_type);
4486 int final_int = INTEGRAL_TYPE_P (final_type);
4487 int final_ptr = POINTER_TYPE_P (final_type);
4488 int final_float = FLOAT_TYPE_P (final_type);
4489 int final_prec = TYPE_PRECISION (final_type);
4490 int final_unsignedp = TREE_UNSIGNED (final_type);
4492 /* In addition to the cases of two conversions in a row
4493 handled below, if we are converting something to its own
4494 type via an object of identical or wider precision, neither
4495 conversion is needed. */
4496 if (inside_type == final_type
4497 && ((inter_int && final_int) || (inter_float && final_float))
4498 && inter_prec >= final_prec)
4499 return TREE_OPERAND (TREE_OPERAND (t, 0), 0);
4501 /* Likewise, if the intermediate and final types are either both
4502 float or both integer, we don't need the middle conversion if
4503 it is wider than the final type and doesn't change the signedness
4504 (for integers). Avoid this if the final type is a pointer
4505 since then we sometimes need the inner conversion. Likewise if
4506 the outer has a precision not equal to the size of its mode. */
4507 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
4508 || (inter_float && inside_float))
4509 && inter_prec >= inside_prec
4510 && (inter_float || inter_unsignedp == inside_unsignedp)
4511 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
4512 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
4514 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
4516 /* If we have a sign-extension of a zero-extended value, we can
4517 replace that by a single zero-extension. */
4518 if (inside_int && inter_int && final_int
4519 && inside_prec < inter_prec && inter_prec < final_prec
4520 && inside_unsignedp && !inter_unsignedp)
4521 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
4523 /* Two conversions in a row are not needed unless:
4524 - some conversion is floating-point (overstrict for now), or
4525 - the intermediate type is narrower than both initial and
4527 - the intermediate type and innermost type differ in signedness,
4528 and the outermost type is wider than the intermediate, or
4529 - the initial type is a pointer type and the precisions of the
4530 intermediate and final types differ, or
4531 - the final type is a pointer type and the precisions of the
4532 initial and intermediate types differ. */
4533 if (! inside_float && ! inter_float && ! final_float
4534 && (inter_prec > inside_prec || inter_prec > final_prec)
4535 && ! (inside_int && inter_int
4536 && inter_unsignedp != inside_unsignedp
4537 && inter_prec < final_prec)
4538 && ((inter_unsignedp && inter_prec > inside_prec)
4539 == (final_unsignedp && final_prec > inter_prec))
4540 && ! (inside_ptr && inter_prec != final_prec)
4541 && ! (final_ptr && inside_prec != inter_prec)
4542 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
4543 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
4545 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
4548 if (TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR
4549 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t, 0), 1))
4550 /* Detect assigning a bitfield. */
4551 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) == COMPONENT_REF
4552 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 1))))
4554 /* Don't leave an assignment inside a conversion
4555 unless assigning a bitfield. */
4556 tree prev = TREE_OPERAND (t, 0);
4557 TREE_OPERAND (t, 0) = TREE_OPERAND (prev, 1);
4558 /* First do the assignment, then return converted constant. */
4559 t = build (COMPOUND_EXPR, TREE_TYPE (t), prev, fold (t));
4565 TREE_CONSTANT (t) = TREE_CONSTANT (arg0);
4568 return fold_convert (t, arg0);
4570 #if 0 /* This loses on &"foo"[0]. */
4575 /* Fold an expression like: "foo"[2] */
4576 if (TREE_CODE (arg0) == STRING_CST
4577 && TREE_CODE (arg1) == INTEGER_CST
4578 && !TREE_INT_CST_HIGH (arg1)
4579 && (i = TREE_INT_CST_LOW (arg1)) < TREE_STRING_LENGTH (arg0))
4581 t = build_int_2 (TREE_STRING_POINTER (arg0)[i], 0);
4582 TREE_TYPE (t) = TREE_TYPE (TREE_TYPE (arg0));
4583 force_fit_type (t, 0);
4590 if (TREE_CODE (arg0) == CONSTRUCTOR)
4592 tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0));
4599 TREE_CONSTANT (t) = wins;
4605 if (TREE_CODE (arg0) == INTEGER_CST)
4607 HOST_WIDE_INT low, high;
4608 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
4609 TREE_INT_CST_HIGH (arg0),
4611 t = build_int_2 (low, high);
4612 TREE_TYPE (t) = type;
4614 = (TREE_OVERFLOW (arg0)
4615 | force_fit_type (t, overflow && !TREE_UNSIGNED (type)));
4616 TREE_CONSTANT_OVERFLOW (t)
4617 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
4619 else if (TREE_CODE (arg0) == REAL_CST)
4620 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
4622 else if (TREE_CODE (arg0) == NEGATE_EXPR)
4623 return TREE_OPERAND (arg0, 0);
4625 /* Convert - (a - b) to (b - a) for non-floating-point. */
4626 else if (TREE_CODE (arg0) == MINUS_EXPR && ! FLOAT_TYPE_P (type))
4627 return build (MINUS_EXPR, type, TREE_OPERAND (arg0, 1),
4628 TREE_OPERAND (arg0, 0));
4635 if (TREE_CODE (arg0) == INTEGER_CST)
4637 if (! TREE_UNSIGNED (type)
4638 && TREE_INT_CST_HIGH (arg0) < 0)
4640 HOST_WIDE_INT low, high;
4641 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
4642 TREE_INT_CST_HIGH (arg0),
4644 t = build_int_2 (low, high);
4645 TREE_TYPE (t) = type;
4647 = (TREE_OVERFLOW (arg0)
4648 | force_fit_type (t, overflow));
4649 TREE_CONSTANT_OVERFLOW (t)
4650 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
4653 else if (TREE_CODE (arg0) == REAL_CST)
4655 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
4656 t = build_real (type,
4657 REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
4660 else if (TREE_CODE (arg0) == ABS_EXPR || TREE_CODE (arg0) == NEGATE_EXPR)
4661 return build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0));
4665 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
4667 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
4668 return build (COMPLEX_EXPR, TREE_TYPE (arg0),
4669 TREE_OPERAND (arg0, 0),
4670 fold (build1 (NEGATE_EXPR,
4671 TREE_TYPE (TREE_TYPE (arg0)),
4672 TREE_OPERAND (arg0, 1))));
4673 else if (TREE_CODE (arg0) == COMPLEX_CST)
4674 return build_complex (type, TREE_OPERAND (arg0, 0),
4675 fold (build1 (NEGATE_EXPR,
4676 TREE_TYPE (TREE_TYPE (arg0)),
4677 TREE_OPERAND (arg0, 1))));
4678 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
4679 return fold (build (TREE_CODE (arg0), type,
4680 fold (build1 (CONJ_EXPR, type,
4681 TREE_OPERAND (arg0, 0))),
4682 fold (build1 (CONJ_EXPR,
4683 type, TREE_OPERAND (arg0, 1)))));
4684 else if (TREE_CODE (arg0) == CONJ_EXPR)
4685 return TREE_OPERAND (arg0, 0);
4691 t = build_int_2 (~ TREE_INT_CST_LOW (arg0),
4692 ~ TREE_INT_CST_HIGH (arg0));
4693 TREE_TYPE (t) = type;
4694 force_fit_type (t, 0);
4695 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg0);
4696 TREE_CONSTANT_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (arg0);
4698 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
4699 return TREE_OPERAND (arg0, 0);
4703 /* A + (-B) -> A - B */
4704 if (TREE_CODE (arg1) == NEGATE_EXPR)
4705 return fold (build (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
4706 else if (! FLOAT_TYPE_P (type))
4708 if (integer_zerop (arg1))
4709 return non_lvalue (convert (type, arg0));
4711 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
4712 with a constant, and the two constants have no bits in common,
4713 we should treat this as a BIT_IOR_EXPR since this may produce more
4715 if (TREE_CODE (arg0) == BIT_AND_EXPR
4716 && TREE_CODE (arg1) == BIT_AND_EXPR
4717 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
4718 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
4719 && integer_zerop (const_binop (BIT_AND_EXPR,
4720 TREE_OPERAND (arg0, 1),
4721 TREE_OPERAND (arg1, 1), 0)))
4723 code = BIT_IOR_EXPR;
4727 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR)
4729 tree arg00, arg01, arg10, arg11;
4730 tree alt0, alt1, same;
4732 /* (A * C) + (B * C) -> (A+B) * C.
4733 We are most concerned about the case where C is a constant,
4734 but other combinations show up during loop reduction. Since
4735 it is not difficult, try all four possibilities. */
4737 arg00 = TREE_OPERAND (arg0, 0);
4738 arg01 = TREE_OPERAND (arg0, 1);
4739 arg10 = TREE_OPERAND (arg1, 0);
4740 arg11 = TREE_OPERAND (arg1, 1);
4743 if (operand_equal_p (arg01, arg11, 0))
4744 same = arg01, alt0 = arg00, alt1 = arg10;
4745 else if (operand_equal_p (arg00, arg10, 0))
4746 same = arg00, alt0 = arg01, alt1 = arg11;
4747 else if (operand_equal_p (arg00, arg11, 0))
4748 same = arg00, alt0 = arg01, alt1 = arg10;
4749 else if (operand_equal_p (arg01, arg10, 0))
4750 same = arg01, alt0 = arg00, alt1 = arg11;
4753 return fold (build (MULT_EXPR, type,
4754 fold (build (PLUS_EXPR, type, alt0, alt1)),
4758 /* In IEEE floating point, x+0 may not equal x. */
4759 else if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
4761 && real_zerop (arg1))
4762 return non_lvalue (convert (type, arg0));
4764 /* In most languages, can't associate operations on floats
4765 through parentheses. Rather than remember where the parentheses
4766 were, we don't associate floats at all. It shouldn't matter much.
4767 However, associating multiplications is only very slightly
4768 inaccurate, so do that if -ffast-math is specified. */
4769 if (FLOAT_TYPE_P (type)
4770 && ! (flag_fast_math && code == MULT_EXPR))
4773 /* The varsign == -1 cases happen only for addition and subtraction.
4774 It says that the arg that was split was really CON minus VAR.
4775 The rest of the code applies to all associative operations. */
4781 if (split_tree (arg0, code, &var, &con, &varsign))
4785 /* EXPR is (CON-VAR) +- ARG1. */
4786 /* If it is + and VAR==ARG1, return just CONST. */
4787 if (code == PLUS_EXPR && operand_equal_p (var, arg1, 0))
4788 return convert (TREE_TYPE (t), con);
4790 /* If ARG0 is a constant, don't change things around;
4791 instead keep all the constant computations together. */
4793 if (TREE_CONSTANT (arg0))
4796 /* Otherwise return (CON +- ARG1) - VAR. */
4797 t = build (MINUS_EXPR, type,
4798 fold (build (code, type, con, arg1)), var);
4802 /* EXPR is (VAR+CON) +- ARG1. */
4803 /* If it is - and VAR==ARG1, return just CONST. */
4804 if (code == MINUS_EXPR && operand_equal_p (var, arg1, 0))
4805 return convert (TREE_TYPE (t), con);
4807 /* If ARG0 is a constant, don't change things around;
4808 instead keep all the constant computations together. */
4810 if (TREE_CONSTANT (arg0))
4813 /* Otherwise return VAR +- (ARG1 +- CON). */
4814 tem = fold (build (code, type, arg1, con));
4815 t = build (code, type, var, tem);
4817 if (integer_zerop (tem)
4818 && (code == PLUS_EXPR || code == MINUS_EXPR))
4819 return convert (type, var);
4820 /* If we have x +/- (c - d) [c an explicit integer]
4821 change it to x -/+ (d - c) since if d is relocatable
4822 then the latter can be a single immediate insn
4823 and the former cannot. */
4824 if (TREE_CODE (tem) == MINUS_EXPR
4825 && TREE_CODE (TREE_OPERAND (tem, 0)) == INTEGER_CST)
4827 tree tem1 = TREE_OPERAND (tem, 1);
4828 TREE_OPERAND (tem, 1) = TREE_OPERAND (tem, 0);
4829 TREE_OPERAND (tem, 0) = tem1;
4831 (code == PLUS_EXPR ? MINUS_EXPR : PLUS_EXPR));
4837 if (split_tree (arg1, code, &var, &con, &varsign))
4839 if (TREE_CONSTANT (arg1))
4844 (code == PLUS_EXPR ? MINUS_EXPR : PLUS_EXPR));
4846 /* EXPR is ARG0 +- (CON +- VAR). */
4847 if (TREE_CODE (t) == MINUS_EXPR
4848 && operand_equal_p (var, arg0, 0))
4850 /* If VAR and ARG0 cancel, return just CON or -CON. */
4851 if (code == PLUS_EXPR)
4852 return convert (TREE_TYPE (t), con);
4853 return fold (build1 (NEGATE_EXPR, TREE_TYPE (t),
4854 convert (TREE_TYPE (t), con)));
4857 t = build (TREE_CODE (t), type,
4858 fold (build (code, TREE_TYPE (t), arg0, con)), var);
4860 if (integer_zerop (TREE_OPERAND (t, 0))
4861 && TREE_CODE (t) == PLUS_EXPR)
4862 return convert (TREE_TYPE (t), var);
4867 #if defined (REAL_IS_NOT_DOUBLE) && ! defined (REAL_ARITHMETIC)
4868 if (TREE_CODE (arg1) == REAL_CST)
4870 #endif /* REAL_IS_NOT_DOUBLE, and no REAL_ARITHMETIC */
4872 t1 = const_binop (code, arg0, arg1, 0);
4873 if (t1 != NULL_TREE)
4875 /* The return value should always have
4876 the same type as the original expression. */
4877 if (TREE_TYPE (t1) != TREE_TYPE (t))
4878 t1 = convert (TREE_TYPE (t), t1);
4885 if (! FLOAT_TYPE_P (type))
4887 if (! wins && integer_zerop (arg0))
4888 return build1 (NEGATE_EXPR, type, arg1);
4889 if (integer_zerop (arg1))
4890 return non_lvalue (convert (type, arg0));
4892 /* (A * C) - (B * C) -> (A-B) * C. Since we are most concerned
4893 about the case where C is a constant, just try one of the
4894 four possibilities. */
4896 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR
4897 && operand_equal_p (TREE_OPERAND (arg0, 1),
4898 TREE_OPERAND (arg1, 1), 0))
4899 return fold (build (MULT_EXPR, type,
4900 fold (build (MINUS_EXPR, type,
4901 TREE_OPERAND (arg0, 0),
4902 TREE_OPERAND (arg1, 0))),
4903 TREE_OPERAND (arg0, 1)));
4905 /* Convert A - (-B) to A + B. */
4906 else if (TREE_CODE (arg1) == NEGATE_EXPR)
4907 return fold (build (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
4909 else if (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
4912 /* Except with IEEE floating point, 0-x equals -x. */
4913 if (! wins && real_zerop (arg0))
4914 return build1 (NEGATE_EXPR, type, arg1);
4915 /* Except with IEEE floating point, x-0 equals x. */
4916 if (real_zerop (arg1))
4917 return non_lvalue (convert (type, arg0));
4920 /* Fold &x - &x. This can happen from &x.foo - &x.
4921 This is unsafe for certain floats even in non-IEEE formats.
4922 In IEEE, it is unsafe because it does wrong for NaNs.
4923 Also note that operand_equal_p is always false if an operand
4926 if ((! FLOAT_TYPE_P (type) || flag_fast_math)
4927 && operand_equal_p (arg0, arg1, 0))
4928 return convert (type, integer_zero_node);
4933 if (! FLOAT_TYPE_P (type))
4935 if (integer_zerop (arg1))
4936 return omit_one_operand (type, arg1, arg0);
4937 if (integer_onep (arg1))
4938 return non_lvalue (convert (type, arg0));
4940 /* ((A / C) * C) is A if the division is an
4941 EXACT_DIV_EXPR. Since C is normally a constant,
4942 just check for one of the four possibilities. */
4944 if (TREE_CODE (arg0) == EXACT_DIV_EXPR
4945 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
4946 return TREE_OPERAND (arg0, 0);
4948 /* (a * (1 << b)) is (a << b) */
4949 if (TREE_CODE (arg1) == LSHIFT_EXPR
4950 && integer_onep (TREE_OPERAND (arg1, 0)))
4951 return fold (build (LSHIFT_EXPR, type, arg0,
4952 TREE_OPERAND (arg1, 1)));
4953 if (TREE_CODE (arg0) == LSHIFT_EXPR
4954 && integer_onep (TREE_OPERAND (arg0, 0)))
4955 return fold (build (LSHIFT_EXPR, type, arg1,
4956 TREE_OPERAND (arg0, 1)));
4960 /* x*0 is 0, except for IEEE floating point. */
4961 if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
4963 && real_zerop (arg1))
4964 return omit_one_operand (type, arg1, arg0);
4965 /* In IEEE floating point, x*1 is not equivalent to x for snans.
4966 However, ANSI says we can drop signals,
4967 so we can do this anyway. */
4968 if (real_onep (arg1))
4969 return non_lvalue (convert (type, arg0));
4971 if (! wins && real_twop (arg1) && current_function_decl != 0
4972 && ! contains_placeholder_p (arg0))
4974 tree arg = save_expr (arg0);
4975 return build (PLUS_EXPR, type, arg, arg);
4983 register enum tree_code code0, code1;
4985 if (integer_all_onesp (arg1))
4986 return omit_one_operand (type, arg1, arg0);
4987 if (integer_zerop (arg1))
4988 return non_lvalue (convert (type, arg0));
4989 t1 = distribute_bit_expr (code, type, arg0, arg1);
4990 if (t1 != NULL_TREE)
4993 /* (A << C1) | (A >> C2) if A is unsigned and C1+C2 is the size of A
4994 is a rotate of A by C1 bits. */
4995 /* (A << B) | (A >> (Z - B)) if A is unsigned and Z is the size of A
4996 is a rotate of A by B bits. */
4998 code0 = TREE_CODE (arg0);
4999 code1 = TREE_CODE (arg1);
5000 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
5001 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
5002 && operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1,0), 0)
5003 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5005 register tree tree01, tree11;
5006 register enum tree_code code01, code11;
5008 tree01 = TREE_OPERAND (arg0, 1);
5009 tree11 = TREE_OPERAND (arg1, 1);
5010 STRIP_NOPS (tree01);
5011 STRIP_NOPS (tree11);
5012 code01 = TREE_CODE (tree01);
5013 code11 = TREE_CODE (tree11);
5014 if (code01 == INTEGER_CST
5015 && code11 == INTEGER_CST
5016 && TREE_INT_CST_HIGH (tree01) == 0
5017 && TREE_INT_CST_HIGH (tree11) == 0
5018 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
5019 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
5020 return build (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
5021 code0 == LSHIFT_EXPR ? tree01 : tree11);
5022 else if (code11 == MINUS_EXPR)
5024 tree tree110, tree111;
5025 tree110 = TREE_OPERAND (tree11, 0);
5026 tree111 = TREE_OPERAND (tree11, 1);
5027 STRIP_NOPS (tree110);
5028 STRIP_NOPS (tree111);
5029 if (TREE_CODE (tree110) == INTEGER_CST
5030 && TREE_INT_CST_HIGH (tree110) == 0
5031 && (TREE_INT_CST_LOW (tree110)
5032 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5033 && operand_equal_p (tree01, tree111, 0))
5034 return build ((code0 == LSHIFT_EXPR
5037 type, TREE_OPERAND (arg0, 0), tree01);
5039 else if (code01 == MINUS_EXPR)
5041 tree tree010, tree011;
5042 tree010 = TREE_OPERAND (tree01, 0);
5043 tree011 = TREE_OPERAND (tree01, 1);
5044 STRIP_NOPS (tree010);
5045 STRIP_NOPS (tree011);
5046 if (TREE_CODE (tree010) == INTEGER_CST
5047 && TREE_INT_CST_HIGH (tree010) == 0
5048 && (TREE_INT_CST_LOW (tree010)
5049 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5050 && operand_equal_p (tree11, tree011, 0))
5051 return build ((code0 != LSHIFT_EXPR
5054 type, TREE_OPERAND (arg0, 0), tree11);
5062 if (integer_zerop (arg1))
5063 return non_lvalue (convert (type, arg0));
5064 if (integer_all_onesp (arg1))
5065 return fold (build1 (BIT_NOT_EXPR, type, arg0));
5070 if (integer_all_onesp (arg1))
5071 return non_lvalue (convert (type, arg0));
5072 if (integer_zerop (arg1))
5073 return omit_one_operand (type, arg1, arg0);
5074 t1 = distribute_bit_expr (code, type, arg0, arg1);
5075 if (t1 != NULL_TREE)
5077 /* Simplify ((int)c & 0x377) into (int)c, if c is unsigned char. */
5078 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == NOP_EXPR
5079 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg1, 0))))
5081 int prec = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg1, 0)));
5082 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
5083 && (~TREE_INT_CST_LOW (arg0)
5084 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
5085 return build1 (NOP_EXPR, type, TREE_OPERAND (arg1, 0));
5087 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
5088 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5090 int prec = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
5091 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
5092 && (~TREE_INT_CST_LOW (arg1)
5093 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
5094 return build1 (NOP_EXPR, type, TREE_OPERAND (arg0, 0));
5098 case BIT_ANDTC_EXPR:
5099 if (integer_all_onesp (arg0))
5100 return non_lvalue (convert (type, arg1));
5101 if (integer_zerop (arg0))
5102 return omit_one_operand (type, arg0, arg1);
5103 if (TREE_CODE (arg1) == INTEGER_CST)
5105 arg1 = fold (build1 (BIT_NOT_EXPR, type, arg1));
5106 code = BIT_AND_EXPR;
5112 /* In most cases, do nothing with a divide by zero. */
5113 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
5114 #ifndef REAL_INFINITY
5115 if (TREE_CODE (arg1) == REAL_CST && real_zerop (arg1))
5118 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
5120 /* In IEEE floating point, x/1 is not equivalent to x for snans.
5121 However, ANSI says we can drop signals, so we can do this anyway. */
5122 if (real_onep (arg1))
5123 return non_lvalue (convert (type, arg0));
5125 /* If ARG1 is a constant, we can convert this to a multiply by the
5126 reciprocal. This does not have the same rounding properties,
5127 so only do this if -ffast-math. We can actually always safely
5128 do it if ARG1 is a power of two, but it's hard to tell if it is
5129 or not in a portable manner. */
5130 if (TREE_CODE (arg1) == REAL_CST)
5133 && 0 != (tem = const_binop (code, build_real (type, dconst1),
5135 return fold (build (MULT_EXPR, type, arg0, tem));
5136 /* Find the reciprocal if optimizing and the result is exact. */
5140 r = TREE_REAL_CST (arg1);
5141 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
5143 tem = build_real (type, r);
5144 return fold (build (MULT_EXPR, type, arg0, tem));
5150 case TRUNC_DIV_EXPR:
5151 case ROUND_DIV_EXPR:
5152 case FLOOR_DIV_EXPR:
5154 case EXACT_DIV_EXPR:
5155 if (integer_onep (arg1))
5156 return non_lvalue (convert (type, arg0));
5157 if (integer_zerop (arg1))
5160 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
5161 operation, EXACT_DIV_EXPR.
5163 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
5164 At one time others generated faster code, it's not clear if they do
5165 after the last round to changes to the DIV code in expmed.c. */
5166 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
5167 && multiple_of_p (type, arg0, arg1))
5168 return fold (build (EXACT_DIV_EXPR, type, arg0, arg1));
5170 /* If we have ((a / C1) / C2) where both division are the same type, try
5171 to simplify. First see if C1 * C2 overflows or not. */
5172 if (TREE_CODE (arg0) == code && TREE_CODE (arg1) == INTEGER_CST
5173 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
5177 new_divisor = const_binop (MULT_EXPR, TREE_OPERAND (arg0, 1), arg1, 0);
5178 tem = const_binop (FLOOR_DIV_EXPR, new_divisor, arg1, 0);
5180 if (TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) == TREE_INT_CST_LOW (tem)
5181 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == TREE_INT_CST_HIGH (tem))
5183 /* If no overflow, divide by C1*C2. */
5184 return fold (build (code, type, TREE_OPERAND (arg0, 0), new_divisor));
5188 /* Look for ((a * C1) / C3) or (((a * C1) + C2) / C3),
5189 where C1 % C3 == 0 or C3 % C1 == 0. We can simplify these
5190 expressions, which often appear in the offsets or sizes of
5191 objects with a varying size. Only deal with positive divisors
5192 and multiplicands. If C2 is negative, we must have C2 % C3 == 0.
5194 Look for NOPs and SAVE_EXPRs inside. */
5196 if (TREE_CODE (arg1) == INTEGER_CST
5197 && tree_int_cst_sgn (arg1) >= 0)
5199 int have_save_expr = 0;
5200 tree c2 = integer_zero_node;
5203 if (TREE_CODE (xarg0) == SAVE_EXPR && SAVE_EXPR_RTL (xarg0) == 0)
5204 have_save_expr = 1, xarg0 = TREE_OPERAND (xarg0, 0);
5208 /* Look inside the dividend and simplify using EXACT_DIV_EXPR
5210 if (TREE_CODE (xarg0) == MULT_EXPR
5211 && multiple_of_p (type, TREE_OPERAND (xarg0, 0), arg1))
5215 t = fold (build (MULT_EXPR, type,
5216 fold (build (EXACT_DIV_EXPR, type,
5217 TREE_OPERAND (xarg0, 0), arg1)),
5218 TREE_OPERAND (xarg0, 1)));
5225 if (TREE_CODE (xarg0) == MULT_EXPR
5226 && multiple_of_p (type, TREE_OPERAND (xarg0, 1), arg1))
5230 t = fold (build (MULT_EXPR, type,
5231 fold (build (EXACT_DIV_EXPR, type,
5232 TREE_OPERAND (xarg0, 1), arg1)),
5233 TREE_OPERAND (xarg0, 0)));
5239 if (TREE_CODE (xarg0) == PLUS_EXPR
5240 && TREE_CODE (TREE_OPERAND (xarg0, 1)) == INTEGER_CST)
5241 c2 = TREE_OPERAND (xarg0, 1), xarg0 = TREE_OPERAND (xarg0, 0);
5242 else if (TREE_CODE (xarg0) == MINUS_EXPR
5243 && TREE_CODE (TREE_OPERAND (xarg0, 1)) == INTEGER_CST
5244 /* If we are doing this computation unsigned, the negate
5246 && ! TREE_UNSIGNED (type))
5248 c2 = fold (build1 (NEGATE_EXPR, type, TREE_OPERAND (xarg0, 1)));
5249 xarg0 = TREE_OPERAND (xarg0, 0);
5252 if (TREE_CODE (xarg0) == SAVE_EXPR && SAVE_EXPR_RTL (xarg0) == 0)
5253 have_save_expr = 1, xarg0 = TREE_OPERAND (xarg0, 0);
5257 if (TREE_CODE (xarg0) == MULT_EXPR
5258 && TREE_CODE (TREE_OPERAND (xarg0, 1)) == INTEGER_CST
5259 && tree_int_cst_sgn (TREE_OPERAND (xarg0, 1)) >= 0
5260 && (integer_zerop (const_binop (TRUNC_MOD_EXPR,
5261 TREE_OPERAND (xarg0, 1), arg1, 1))
5262 || integer_zerop (const_binop (TRUNC_MOD_EXPR, arg1,
5263 TREE_OPERAND (xarg0, 1), 1)))
5264 && (tree_int_cst_sgn (c2) >= 0
5265 || integer_zerop (const_binop (TRUNC_MOD_EXPR, c2,
5268 tree outer_div = integer_one_node;
5269 tree c1 = TREE_OPERAND (xarg0, 1);
5272 /* If C3 > C1, set them equal and do a divide by
5273 C3/C1 at the end of the operation. */
5274 if (tree_int_cst_lt (c1, c3))
5275 outer_div = const_binop (code, c3, c1, 0), c3 = c1;
5277 /* The result is A * (C1/C3) + (C2/C3). */
5278 t = fold (build (PLUS_EXPR, type,
5279 fold (build (MULT_EXPR, type,
5280 TREE_OPERAND (xarg0, 0),
5281 const_binop (code, c1, c3, 1))),
5282 const_binop (code, c2, c3, 1)));
5284 if (! integer_onep (outer_div))
5285 t = fold (build (code, type, t, convert (type, outer_div)));
5297 case FLOOR_MOD_EXPR:
5298 case ROUND_MOD_EXPR:
5299 case TRUNC_MOD_EXPR:
5300 if (integer_onep (arg1))
5301 return omit_one_operand (type, integer_zero_node, arg0);
5302 if (integer_zerop (arg1))
5305 /* Look for ((a * C1) % C3) or (((a * C1) + C2) % C3),
5306 where C1 % C3 == 0. Handle similarly to the division case,
5307 but don't bother with SAVE_EXPRs. */
5309 if (TREE_CODE (arg1) == INTEGER_CST
5310 && ! integer_zerop (arg1))
5312 tree c2 = integer_zero_node;
5315 if (TREE_CODE (xarg0) == PLUS_EXPR
5316 && TREE_CODE (TREE_OPERAND (xarg0, 1)) == INTEGER_CST)
5317 c2 = TREE_OPERAND (xarg0, 1), xarg0 = TREE_OPERAND (xarg0, 0);
5318 else if (TREE_CODE (xarg0) == MINUS_EXPR
5319 && TREE_CODE (TREE_OPERAND (xarg0, 1)) == INTEGER_CST
5320 && ! TREE_UNSIGNED (type))
5322 c2 = fold (build1 (NEGATE_EXPR, type, TREE_OPERAND (xarg0, 1)));
5323 xarg0 = TREE_OPERAND (xarg0, 0);
5328 if (TREE_CODE (xarg0) == MULT_EXPR
5329 && TREE_CODE (TREE_OPERAND (xarg0, 1)) == INTEGER_CST
5330 && integer_zerop (const_binop (TRUNC_MOD_EXPR,
5331 TREE_OPERAND (xarg0, 1),
5333 && tree_int_cst_sgn (c2) >= 0)
5334 /* The result is (C2%C3). */
5335 return omit_one_operand (type, const_binop (code, c2, arg1, 1),
5336 TREE_OPERAND (xarg0, 0));
5345 if (integer_zerop (arg1))
5346 return non_lvalue (convert (type, arg0));
5347 /* Since negative shift count is not well-defined,
5348 don't try to compute it in the compiler. */
5349 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
5351 /* Rewrite an LROTATE_EXPR by a constant into an
5352 RROTATE_EXPR by a new constant. */
5353 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
5355 TREE_SET_CODE (t, RROTATE_EXPR);
5356 code = RROTATE_EXPR;
5357 TREE_OPERAND (t, 1) = arg1
5360 convert (TREE_TYPE (arg1),
5361 build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type)), 0)),
5363 if (tree_int_cst_sgn (arg1) < 0)
5367 /* If we have a rotate of a bit operation with the rotate count and
5368 the second operand of the bit operation both constant,
5369 permute the two operations. */
5370 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
5371 && (TREE_CODE (arg0) == BIT_AND_EXPR
5372 || TREE_CODE (arg0) == BIT_ANDTC_EXPR
5373 || TREE_CODE (arg0) == BIT_IOR_EXPR
5374 || TREE_CODE (arg0) == BIT_XOR_EXPR)
5375 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
5376 return fold (build (TREE_CODE (arg0), type,
5377 fold (build (code, type,
5378 TREE_OPERAND (arg0, 0), arg1)),
5379 fold (build (code, type,
5380 TREE_OPERAND (arg0, 1), arg1))));
5382 /* Two consecutive rotates adding up to the width of the mode can
5384 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
5385 && TREE_CODE (arg0) == RROTATE_EXPR
5386 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5387 && TREE_INT_CST_HIGH (arg1) == 0
5388 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
5389 && ((TREE_INT_CST_LOW (arg1)
5390 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
5391 == GET_MODE_BITSIZE (TYPE_MODE (type))))
5392 return TREE_OPERAND (arg0, 0);
5397 if (operand_equal_p (arg0, arg1, 0))
5399 if (INTEGRAL_TYPE_P (type)
5400 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), 1))
5401 return omit_one_operand (type, arg1, arg0);
5405 if (operand_equal_p (arg0, arg1, 0))
5407 if (INTEGRAL_TYPE_P (type)
5408 && TYPE_MAX_VALUE (type)
5409 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), 1))
5410 return omit_one_operand (type, arg1, arg0);
5413 case TRUTH_NOT_EXPR:
5414 /* Note that the operand of this must be an int
5415 and its values must be 0 or 1.
5416 ("true" is a fixed value perhaps depending on the language,
5417 but we don't handle values other than 1 correctly yet.) */
5418 tem = invert_truthvalue (arg0);
5419 /* Avoid infinite recursion. */
5420 if (TREE_CODE (tem) == TRUTH_NOT_EXPR)
5422 return convert (type, tem);
5424 case TRUTH_ANDIF_EXPR:
5425 /* Note that the operands of this must be ints
5426 and their values must be 0 or 1.
5427 ("true" is a fixed value perhaps depending on the language.) */
5428 /* If first arg is constant zero, return it. */
5429 if (integer_zerop (arg0))
5431 case TRUTH_AND_EXPR:
5432 /* If either arg is constant true, drop it. */
5433 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
5434 return non_lvalue (arg1);
5435 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
5436 return non_lvalue (arg0);
5437 /* If second arg is constant zero, result is zero, but first arg
5438 must be evaluated. */
5439 if (integer_zerop (arg1))
5440 return omit_one_operand (type, arg1, arg0);
5441 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
5442 case will be handled here. */
5443 if (integer_zerop (arg0))
5444 return omit_one_operand (type, arg0, arg1);
5447 /* We only do these simplifications if we are optimizing. */
5451 /* Check for things like (A || B) && (A || C). We can convert this
5452 to A || (B && C). Note that either operator can be any of the four
5453 truth and/or operations and the transformation will still be
5454 valid. Also note that we only care about order for the
5455 ANDIF and ORIF operators. If B contains side effects, this
5456 might change the truth-value of A. */
5457 if (TREE_CODE (arg0) == TREE_CODE (arg1)
5458 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
5459 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
5460 || TREE_CODE (arg0) == TRUTH_AND_EXPR
5461 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
5462 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
5464 tree a00 = TREE_OPERAND (arg0, 0);
5465 tree a01 = TREE_OPERAND (arg0, 1);
5466 tree a10 = TREE_OPERAND (arg1, 0);
5467 tree a11 = TREE_OPERAND (arg1, 1);
5468 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
5469 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
5470 && (code == TRUTH_AND_EXPR
5471 || code == TRUTH_OR_EXPR));
5473 if (operand_equal_p (a00, a10, 0))
5474 return fold (build (TREE_CODE (arg0), type, a00,
5475 fold (build (code, type, a01, a11))));
5476 else if (commutative && operand_equal_p (a00, a11, 0))
5477 return fold (build (TREE_CODE (arg0), type, a00,
5478 fold (build (code, type, a01, a10))));
5479 else if (commutative && operand_equal_p (a01, a10, 0))
5480 return fold (build (TREE_CODE (arg0), type, a01,
5481 fold (build (code, type, a00, a11))));
5483 /* This case if tricky because we must either have commutative
5484 operators or else A10 must not have side-effects. */
5486 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
5487 && operand_equal_p (a01, a11, 0))
5488 return fold (build (TREE_CODE (arg0), type,
5489 fold (build (code, type, a00, a10)),
5493 /* See if we can build a range comparison. */
5494 if (0 != (tem = fold_range_test (t)))
5497 /* Check for the possibility of merging component references. If our
5498 lhs is another similar operation, try to merge its rhs with our
5499 rhs. Then try to merge our lhs and rhs. */
5500 if (TREE_CODE (arg0) == code
5501 && 0 != (tem = fold_truthop (code, type,
5502 TREE_OPERAND (arg0, 1), arg1)))
5503 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
5505 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
5510 case TRUTH_ORIF_EXPR:
5511 /* Note that the operands of this must be ints
5512 and their values must be 0 or true.
5513 ("true" is a fixed value perhaps depending on the language.) */
5514 /* If first arg is constant true, return it. */
5515 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
5518 /* If either arg is constant zero, drop it. */
5519 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
5520 return non_lvalue (arg1);
5521 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1))
5522 return non_lvalue (arg0);
5523 /* If second arg is constant true, result is true, but we must
5524 evaluate first arg. */
5525 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
5526 return omit_one_operand (type, arg1, arg0);
5527 /* Likewise for first arg, but note this only occurs here for
5529 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
5530 return omit_one_operand (type, arg0, arg1);
5533 case TRUTH_XOR_EXPR:
5534 /* If either arg is constant zero, drop it. */
5535 if (integer_zerop (arg0))
5536 return non_lvalue (arg1);
5537 if (integer_zerop (arg1))
5538 return non_lvalue (arg0);
5539 /* If either arg is constant true, this is a logical inversion. */
5540 if (integer_onep (arg0))
5541 return non_lvalue (invert_truthvalue (arg1));
5542 if (integer_onep (arg1))
5543 return non_lvalue (invert_truthvalue (arg0));
5552 /* If one arg is a constant integer, put it last. */
5553 if (TREE_CODE (arg0) == INTEGER_CST
5554 && TREE_CODE (arg1) != INTEGER_CST)
5556 TREE_OPERAND (t, 0) = arg1;
5557 TREE_OPERAND (t, 1) = arg0;
5558 arg0 = TREE_OPERAND (t, 0);
5559 arg1 = TREE_OPERAND (t, 1);
5560 code = swap_tree_comparison (code);
5561 TREE_SET_CODE (t, code);
5564 /* Convert foo++ == CONST into ++foo == CONST + INCR.
5565 First, see if one arg is constant; find the constant arg
5566 and the other one. */
5568 tree constop = 0, varop = NULL_TREE;
5569 int constopnum = -1;
5571 if (TREE_CONSTANT (arg1))
5572 constopnum = 1, constop = arg1, varop = arg0;
5573 if (TREE_CONSTANT (arg0))
5574 constopnum = 0, constop = arg0, varop = arg1;
5576 if (constop && TREE_CODE (varop) == POSTINCREMENT_EXPR)
5578 /* This optimization is invalid for ordered comparisons
5579 if CONST+INCR overflows or if foo+incr might overflow.
5580 This optimization is invalid for floating point due to rounding.
5581 For pointer types we assume overflow doesn't happen. */
5582 if (POINTER_TYPE_P (TREE_TYPE (varop))
5583 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
5584 && (code == EQ_EXPR || code == NE_EXPR)))
5587 = fold (build (PLUS_EXPR, TREE_TYPE (varop),
5588 constop, TREE_OPERAND (varop, 1)));
5589 TREE_SET_CODE (varop, PREINCREMENT_EXPR);
5591 /* If VAROP is a reference to a bitfield, we must mask
5592 the constant by the width of the field. */
5593 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
5594 && DECL_BIT_FIELD(TREE_OPERAND
5595 (TREE_OPERAND (varop, 0), 1)))
5598 = TREE_INT_CST_LOW (DECL_SIZE
5600 (TREE_OPERAND (varop, 0), 1)));
5601 tree mask, unsigned_type;
5603 tree folded_compare;
5605 /* First check whether the comparison would come out
5606 always the same. If we don't do that we would
5607 change the meaning with the masking. */
5608 if (constopnum == 0)
5609 folded_compare = fold (build (code, type, constop,
5610 TREE_OPERAND (varop, 0)));
5612 folded_compare = fold (build (code, type,
5613 TREE_OPERAND (varop, 0),
5615 if (integer_zerop (folded_compare)
5616 || integer_onep (folded_compare))
5617 return omit_one_operand (type, folded_compare, varop);
5619 unsigned_type = type_for_size (size, 1);
5620 precision = TYPE_PRECISION (unsigned_type);
5621 mask = build_int_2 (~0, ~0);
5622 TREE_TYPE (mask) = unsigned_type;
5623 force_fit_type (mask, 0);
5624 mask = const_binop (RSHIFT_EXPR, mask,
5625 size_int (precision - size), 0);
5626 newconst = fold (build (BIT_AND_EXPR,
5627 TREE_TYPE (varop), newconst,
5628 convert (TREE_TYPE (varop),
5633 t = build (code, type, TREE_OPERAND (t, 0),
5634 TREE_OPERAND (t, 1));
5635 TREE_OPERAND (t, constopnum) = newconst;
5639 else if (constop && TREE_CODE (varop) == POSTDECREMENT_EXPR)
5641 if (POINTER_TYPE_P (TREE_TYPE (varop))
5642 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
5643 && (code == EQ_EXPR || code == NE_EXPR)))
5646 = fold (build (MINUS_EXPR, TREE_TYPE (varop),
5647 constop, TREE_OPERAND (varop, 1)));
5648 TREE_SET_CODE (varop, PREDECREMENT_EXPR);
5650 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
5651 && DECL_BIT_FIELD(TREE_OPERAND
5652 (TREE_OPERAND (varop, 0), 1)))
5655 = TREE_INT_CST_LOW (DECL_SIZE
5657 (TREE_OPERAND (varop, 0), 1)));
5658 tree mask, unsigned_type;
5660 tree folded_compare;
5662 if (constopnum == 0)
5663 folded_compare = fold (build (code, type, constop,
5664 TREE_OPERAND (varop, 0)));
5666 folded_compare = fold (build (code, type,
5667 TREE_OPERAND (varop, 0),
5669 if (integer_zerop (folded_compare)
5670 || integer_onep (folded_compare))
5671 return omit_one_operand (type, folded_compare, varop);
5673 unsigned_type = type_for_size (size, 1);
5674 precision = TYPE_PRECISION (unsigned_type);
5675 mask = build_int_2 (~0, ~0);
5676 TREE_TYPE (mask) = TREE_TYPE (varop);
5677 force_fit_type (mask, 0);
5678 mask = const_binop (RSHIFT_EXPR, mask,
5679 size_int (precision - size), 0);
5680 newconst = fold (build (BIT_AND_EXPR,
5681 TREE_TYPE (varop), newconst,
5682 convert (TREE_TYPE (varop),
5687 t = build (code, type, TREE_OPERAND (t, 0),
5688 TREE_OPERAND (t, 1));
5689 TREE_OPERAND (t, constopnum) = newconst;
5695 /* Change X >= CST to X > (CST - 1) if CST is positive. */
5696 if (TREE_CODE (arg1) == INTEGER_CST
5697 && TREE_CODE (arg0) != INTEGER_CST
5698 && tree_int_cst_sgn (arg1) > 0)
5700 switch (TREE_CODE (t))
5704 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
5705 t = build (code, type, TREE_OPERAND (t, 0), arg1);
5710 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
5711 t = build (code, type, TREE_OPERAND (t, 0), arg1);
5719 /* If this is an EQ or NE comparison with zero and ARG0 is
5720 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
5721 two operations, but the latter can be done in one less insn
5722 on machines that have only two-operand insns or on which a
5723 constant cannot be the first operand. */
5724 if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR)
5725 && TREE_CODE (arg0) == BIT_AND_EXPR)
5727 if (TREE_CODE (TREE_OPERAND (arg0, 0)) == LSHIFT_EXPR
5728 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 0), 0)))
5730 fold (build (code, type,
5731 build (BIT_AND_EXPR, TREE_TYPE (arg0),
5733 TREE_TYPE (TREE_OPERAND (arg0, 0)),
5734 TREE_OPERAND (arg0, 1),
5735 TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)),
5736 convert (TREE_TYPE (arg0),
5739 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
5740 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
5742 fold (build (code, type,
5743 build (BIT_AND_EXPR, TREE_TYPE (arg0),
5745 TREE_TYPE (TREE_OPERAND (arg0, 1)),
5746 TREE_OPERAND (arg0, 0),
5747 TREE_OPERAND (TREE_OPERAND (arg0, 1), 1)),
5748 convert (TREE_TYPE (arg0),
5753 /* If this is an NE or EQ comparison of zero against the result of a
5754 signed MOD operation whose second operand is a power of 2, make
5755 the MOD operation unsigned since it is simpler and equivalent. */
5756 if ((code == NE_EXPR || code == EQ_EXPR)
5757 && integer_zerop (arg1)
5758 && ! TREE_UNSIGNED (TREE_TYPE (arg0))
5759 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
5760 || TREE_CODE (arg0) == CEIL_MOD_EXPR
5761 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
5762 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
5763 && integer_pow2p (TREE_OPERAND (arg0, 1)))
5765 tree newtype = unsigned_type (TREE_TYPE (arg0));
5766 tree newmod = build (TREE_CODE (arg0), newtype,
5767 convert (newtype, TREE_OPERAND (arg0, 0)),
5768 convert (newtype, TREE_OPERAND (arg0, 1)));
5770 return build (code, type, newmod, convert (newtype, arg1));
5773 /* If this is an NE comparison of zero with an AND of one, remove the
5774 comparison since the AND will give the correct value. */
5775 if (code == NE_EXPR && integer_zerop (arg1)
5776 && TREE_CODE (arg0) == BIT_AND_EXPR
5777 && integer_onep (TREE_OPERAND (arg0, 1)))
5778 return convert (type, arg0);
5780 /* If we have (A & C) == C where C is a power of 2, convert this into
5781 (A & C) != 0. Similarly for NE_EXPR. */
5782 if ((code == EQ_EXPR || code == NE_EXPR)
5783 && TREE_CODE (arg0) == BIT_AND_EXPR
5784 && integer_pow2p (TREE_OPERAND (arg0, 1))
5785 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
5786 return build (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
5787 arg0, integer_zero_node);
5789 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
5790 and similarly for >= into !=. */
5791 if ((code == LT_EXPR || code == GE_EXPR)
5792 && TREE_UNSIGNED (TREE_TYPE (arg0))
5793 && TREE_CODE (arg1) == LSHIFT_EXPR
5794 && integer_onep (TREE_OPERAND (arg1, 0)))
5795 return build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
5796 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
5797 TREE_OPERAND (arg1, 1)),
5798 convert (TREE_TYPE (arg0), integer_zero_node));
5800 else if ((code == LT_EXPR || code == GE_EXPR)
5801 && TREE_UNSIGNED (TREE_TYPE (arg0))
5802 && (TREE_CODE (arg1) == NOP_EXPR
5803 || TREE_CODE (arg1) == CONVERT_EXPR)
5804 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
5805 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
5807 build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
5808 convert (TREE_TYPE (arg0),
5809 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
5810 TREE_OPERAND (TREE_OPERAND (arg1, 0), 1))),
5811 convert (TREE_TYPE (arg0), integer_zero_node));
5813 /* Simplify comparison of something with itself. (For IEEE
5814 floating-point, we can only do some of these simplifications.) */
5815 if (operand_equal_p (arg0, arg1, 0))
5822 if (INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
5823 return constant_boolean_node (1, type);
5825 TREE_SET_CODE (t, code);
5829 /* For NE, we can only do this simplification if integer. */
5830 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
5832 /* ... fall through ... */
5835 return constant_boolean_node (0, type);
5841 /* An unsigned comparison against 0 can be simplified. */
5842 if (integer_zerop (arg1)
5843 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
5844 || POINTER_TYPE_P (TREE_TYPE (arg1)))
5845 && TREE_UNSIGNED (TREE_TYPE (arg1)))
5847 switch (TREE_CODE (t))
5851 TREE_SET_CODE (t, NE_EXPR);
5855 TREE_SET_CODE (t, EQ_EXPR);
5858 return omit_one_operand (type,
5859 convert (type, integer_one_node),
5862 return omit_one_operand (type,
5863 convert (type, integer_zero_node),
5870 /* An unsigned <= 0x7fffffff can be simplified. */
5872 int width = TYPE_PRECISION (TREE_TYPE (arg1));
5873 if (TREE_CODE (arg1) == INTEGER_CST
5874 && ! TREE_CONSTANT_OVERFLOW (arg1)
5875 && width <= HOST_BITS_PER_WIDE_INT
5876 && TREE_INT_CST_LOW (arg1) == ((HOST_WIDE_INT) 1 << (width - 1)) - 1
5877 && TREE_INT_CST_HIGH (arg1) == 0
5878 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
5879 || POINTER_TYPE_P (TREE_TYPE (arg1)))
5880 && TREE_UNSIGNED (TREE_TYPE (arg1)))
5882 switch (TREE_CODE (t))
5885 return fold (build (GE_EXPR, type,
5886 convert (signed_type (TREE_TYPE (arg0)),
5888 convert (signed_type (TREE_TYPE (arg1)),
5889 integer_zero_node)));
5891 return fold (build (LT_EXPR, type,
5892 convert (signed_type (TREE_TYPE (arg0)),
5894 convert (signed_type (TREE_TYPE (arg1)),
5895 integer_zero_node)));
5902 /* If we are comparing an expression that just has comparisons
5903 of two integer values, arithmetic expressions of those comparisons,
5904 and constants, we can simplify it. There are only three cases
5905 to check: the two values can either be equal, the first can be
5906 greater, or the second can be greater. Fold the expression for
5907 those three values. Since each value must be 0 or 1, we have
5908 eight possibilities, each of which corresponds to the constant 0
5909 or 1 or one of the six possible comparisons.
5911 This handles common cases like (a > b) == 0 but also handles
5912 expressions like ((x > y) - (y > x)) > 0, which supposedly
5913 occur in macroized code. */
5915 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
5917 tree cval1 = 0, cval2 = 0;
5920 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
5921 /* Don't handle degenerate cases here; they should already
5922 have been handled anyway. */
5923 && cval1 != 0 && cval2 != 0
5924 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
5925 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
5926 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
5927 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
5928 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
5929 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
5930 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
5932 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
5933 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
5935 /* We can't just pass T to eval_subst in case cval1 or cval2
5936 was the same as ARG1. */
5939 = fold (build (code, type,
5940 eval_subst (arg0, cval1, maxval, cval2, minval),
5943 = fold (build (code, type,
5944 eval_subst (arg0, cval1, maxval, cval2, maxval),
5947 = fold (build (code, type,
5948 eval_subst (arg0, cval1, minval, cval2, maxval),
5951 /* All three of these results should be 0 or 1. Confirm they
5952 are. Then use those values to select the proper code
5955 if ((integer_zerop (high_result)
5956 || integer_onep (high_result))
5957 && (integer_zerop (equal_result)
5958 || integer_onep (equal_result))
5959 && (integer_zerop (low_result)
5960 || integer_onep (low_result)))
5962 /* Make a 3-bit mask with the high-order bit being the
5963 value for `>', the next for '=', and the low for '<'. */
5964 switch ((integer_onep (high_result) * 4)
5965 + (integer_onep (equal_result) * 2)
5966 + integer_onep (low_result))
5970 return omit_one_operand (type, integer_zero_node, arg0);
5991 return omit_one_operand (type, integer_one_node, arg0);
5994 t = build (code, type, cval1, cval2);
5996 return save_expr (t);
6003 /* If this is a comparison of a field, we may be able to simplify it. */
6004 if ((TREE_CODE (arg0) == COMPONENT_REF
6005 || TREE_CODE (arg0) == BIT_FIELD_REF)
6006 && (code == EQ_EXPR || code == NE_EXPR)
6007 /* Handle the constant case even without -O
6008 to make sure the warnings are given. */
6009 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
6011 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
6015 /* If this is a comparison of complex values and either or both sides
6016 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
6017 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
6018 This may prevent needless evaluations. */
6019 if ((code == EQ_EXPR || code == NE_EXPR)
6020 && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
6021 && (TREE_CODE (arg0) == COMPLEX_EXPR
6022 || TREE_CODE (arg1) == COMPLEX_EXPR
6023 || TREE_CODE (arg0) == COMPLEX_CST
6024 || TREE_CODE (arg1) == COMPLEX_CST))
6026 tree subtype = TREE_TYPE (TREE_TYPE (arg0));
6027 tree real0, imag0, real1, imag1;
6029 arg0 = save_expr (arg0);
6030 arg1 = save_expr (arg1);
6031 real0 = fold (build1 (REALPART_EXPR, subtype, arg0));
6032 imag0 = fold (build1 (IMAGPART_EXPR, subtype, arg0));
6033 real1 = fold (build1 (REALPART_EXPR, subtype, arg1));
6034 imag1 = fold (build1 (IMAGPART_EXPR, subtype, arg1));
6036 return fold (build ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR
6039 fold (build (code, type, real0, real1)),
6040 fold (build (code, type, imag0, imag1))));
6043 /* From here on, the only cases we handle are when the result is
6044 known to be a constant.
6046 To compute GT, swap the arguments and do LT.
6047 To compute GE, do LT and invert the result.
6048 To compute LE, swap the arguments, do LT and invert the result.
6049 To compute NE, do EQ and invert the result.
6051 Therefore, the code below must handle only EQ and LT. */
6053 if (code == LE_EXPR || code == GT_EXPR)
6055 tem = arg0, arg0 = arg1, arg1 = tem;
6056 code = swap_tree_comparison (code);
6059 /* Note that it is safe to invert for real values here because we
6060 will check below in the one case that it matters. */
6063 if (code == NE_EXPR || code == GE_EXPR)
6066 code = invert_tree_comparison (code);
6069 /* Compute a result for LT or EQ if args permit;
6070 otherwise return T. */
6071 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
6073 if (code == EQ_EXPR)
6074 t1 = build_int_2 ((TREE_INT_CST_LOW (arg0)
6075 == TREE_INT_CST_LOW (arg1))
6076 && (TREE_INT_CST_HIGH (arg0)
6077 == TREE_INT_CST_HIGH (arg1)),
6080 t1 = build_int_2 ((TREE_UNSIGNED (TREE_TYPE (arg0))
6081 ? INT_CST_LT_UNSIGNED (arg0, arg1)
6082 : INT_CST_LT (arg0, arg1)),
6086 #if 0 /* This is no longer useful, but breaks some real code. */
6087 /* Assume a nonexplicit constant cannot equal an explicit one,
6088 since such code would be undefined anyway.
6089 Exception: on sysvr4, using #pragma weak,
6090 a label can come out as 0. */
6091 else if (TREE_CODE (arg1) == INTEGER_CST
6092 && !integer_zerop (arg1)
6093 && TREE_CONSTANT (arg0)
6094 && TREE_CODE (arg0) == ADDR_EXPR
6096 t1 = build_int_2 (0, 0);
6098 /* Two real constants can be compared explicitly. */
6099 else if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
6101 /* If either operand is a NaN, the result is false with two
6102 exceptions: First, an NE_EXPR is true on NaNs, but that case
6103 is already handled correctly since we will be inverting the
6104 result for NE_EXPR. Second, if we had inverted a LE_EXPR
6105 or a GE_EXPR into a LT_EXPR, we must return true so that it
6106 will be inverted into false. */
6108 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
6109 || REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
6110 t1 = build_int_2 (invert && code == LT_EXPR, 0);
6112 else if (code == EQ_EXPR)
6113 t1 = build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (arg0),
6114 TREE_REAL_CST (arg1)),
6117 t1 = build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (arg0),
6118 TREE_REAL_CST (arg1)),
6122 if (t1 == NULL_TREE)
6126 TREE_INT_CST_LOW (t1) ^= 1;
6128 TREE_TYPE (t1) = type;
6129 if (TREE_CODE (type) == BOOLEAN_TYPE)
6130 return truthvalue_conversion (t1);
6134 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
6135 so all simple results must be passed through pedantic_non_lvalue. */
6136 if (TREE_CODE (arg0) == INTEGER_CST)
6137 return pedantic_non_lvalue
6138 (TREE_OPERAND (t, (integer_zerop (arg0) ? 2 : 1)));
6139 else if (operand_equal_p (arg1, TREE_OPERAND (expr, 2), 0))
6140 return pedantic_omit_one_operand (type, arg1, arg0);
6142 /* If the second operand is zero, invert the comparison and swap
6143 the second and third operands. Likewise if the second operand
6144 is constant and the third is not or if the third operand is
6145 equivalent to the first operand of the comparison. */
6147 if (integer_zerop (arg1)
6148 || (TREE_CONSTANT (arg1) && ! TREE_CONSTANT (TREE_OPERAND (t, 2)))
6149 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
6150 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
6151 TREE_OPERAND (t, 2),
6152 TREE_OPERAND (arg0, 1))))
6154 /* See if this can be inverted. If it can't, possibly because
6155 it was a floating-point inequality comparison, don't do
6157 tem = invert_truthvalue (arg0);
6159 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
6161 t = build (code, type, tem,
6162 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
6164 /* arg1 should be the first argument of the new T. */
6165 arg1 = TREE_OPERAND (t, 1);
6170 /* If we have A op B ? A : C, we may be able to convert this to a
6171 simpler expression, depending on the operation and the values
6172 of B and C. IEEE floating point prevents this though,
6173 because A or B might be -0.0 or a NaN. */
6175 if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
6176 && (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
6177 || ! FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 0)))
6179 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
6180 arg1, TREE_OPERAND (arg0, 1)))
6182 tree arg2 = TREE_OPERAND (t, 2);
6183 enum tree_code comp_code = TREE_CODE (arg0);
6187 /* If we have A op 0 ? A : -A, this is A, -A, abs (A), or abs (-A),
6188 depending on the comparison operation. */
6189 if ((FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 1)))
6190 ? real_zerop (TREE_OPERAND (arg0, 1))
6191 : integer_zerop (TREE_OPERAND (arg0, 1)))
6192 && TREE_CODE (arg2) == NEGATE_EXPR
6193 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
6197 return pedantic_non_lvalue
6198 (fold (build1 (NEGATE_EXPR, type, arg1)));
6200 return pedantic_non_lvalue (convert (type, arg1));
6203 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
6204 arg1 = convert (signed_type (TREE_TYPE (arg1)), arg1);
6205 return pedantic_non_lvalue
6206 (convert (type, fold (build1 (ABS_EXPR,
6207 TREE_TYPE (arg1), arg1))));
6210 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
6211 arg1 = convert (signed_type (TREE_TYPE (arg1)), arg1);
6212 return pedantic_non_lvalue
6213 (fold (build1 (NEGATE_EXPR, type,
6215 fold (build1 (ABS_EXPR,
6222 /* If this is A != 0 ? A : 0, this is simply A. For ==, it is
6225 if (integer_zerop (TREE_OPERAND (arg0, 1)) && integer_zerop (arg2))
6227 if (comp_code == NE_EXPR)
6228 return pedantic_non_lvalue (convert (type, arg1));
6229 else if (comp_code == EQ_EXPR)
6230 return pedantic_non_lvalue (convert (type, integer_zero_node));
6233 /* If this is A op B ? A : B, this is either A, B, min (A, B),
6234 or max (A, B), depending on the operation. */
6236 if (operand_equal_for_comparison_p (TREE_OPERAND (arg0, 1),
6237 arg2, TREE_OPERAND (arg0, 0)))
6239 tree comp_op0 = TREE_OPERAND (arg0, 0);
6240 tree comp_op1 = TREE_OPERAND (arg0, 1);
6241 tree comp_type = TREE_TYPE (comp_op0);
6246 return pedantic_non_lvalue (convert (type, arg2));
6248 return pedantic_non_lvalue (convert (type, arg1));
6251 /* In C++ a ?: expression can be an lvalue, so put the
6252 operand which will be used if they are equal first
6253 so that we can convert this back to the
6254 corresponding COND_EXPR. */
6255 return pedantic_non_lvalue
6256 (convert (type, (fold (build (MIN_EXPR, comp_type,
6257 (comp_code == LE_EXPR
6258 ? comp_op0 : comp_op1),
6259 (comp_code == LE_EXPR
6260 ? comp_op1 : comp_op0))))));
6264 return pedantic_non_lvalue
6265 (convert (type, fold (build (MAX_EXPR, comp_type,
6266 (comp_code == GE_EXPR
6267 ? comp_op0 : comp_op1),
6268 (comp_code == GE_EXPR
6269 ? comp_op1 : comp_op0)))));
6276 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
6277 we might still be able to simplify this. For example,
6278 if C1 is one less or one more than C2, this might have started
6279 out as a MIN or MAX and been transformed by this function.
6280 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
6282 if (INTEGRAL_TYPE_P (type)
6283 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6284 && TREE_CODE (arg2) == INTEGER_CST)
6288 /* We can replace A with C1 in this case. */
6289 arg1 = convert (type, TREE_OPERAND (arg0, 1));
6290 t = build (code, type, TREE_OPERAND (t, 0), arg1,
6291 TREE_OPERAND (t, 2));
6295 /* If C1 is C2 + 1, this is min(A, C2). */
6296 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
6297 && operand_equal_p (TREE_OPERAND (arg0, 1),
6298 const_binop (PLUS_EXPR, arg2,
6299 integer_one_node, 0), 1))
6300 return pedantic_non_lvalue
6301 (fold (build (MIN_EXPR, type, arg1, arg2)));
6305 /* If C1 is C2 - 1, this is min(A, C2). */
6306 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
6307 && operand_equal_p (TREE_OPERAND (arg0, 1),
6308 const_binop (MINUS_EXPR, arg2,
6309 integer_one_node, 0), 1))
6310 return pedantic_non_lvalue
6311 (fold (build (MIN_EXPR, type, arg1, arg2)));
6315 /* If C1 is C2 - 1, this is max(A, C2). */
6316 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
6317 && operand_equal_p (TREE_OPERAND (arg0, 1),
6318 const_binop (MINUS_EXPR, arg2,
6319 integer_one_node, 0), 1))
6320 return pedantic_non_lvalue
6321 (fold (build (MAX_EXPR, type, arg1, arg2)));
6325 /* If C1 is C2 + 1, this is max(A, C2). */
6326 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
6327 && operand_equal_p (TREE_OPERAND (arg0, 1),
6328 const_binop (PLUS_EXPR, arg2,
6329 integer_one_node, 0), 1))
6330 return pedantic_non_lvalue
6331 (fold (build (MAX_EXPR, type, arg1, arg2)));
6340 /* If the second operand is simpler than the third, swap them
6341 since that produces better jump optimization results. */
6342 if ((TREE_CONSTANT (arg1) || TREE_CODE_CLASS (TREE_CODE (arg1)) == 'd'
6343 || TREE_CODE (arg1) == SAVE_EXPR)
6344 && ! (TREE_CONSTANT (TREE_OPERAND (t, 2))
6345 || TREE_CODE_CLASS (TREE_CODE (TREE_OPERAND (t, 2))) == 'd'
6346 || TREE_CODE (TREE_OPERAND (t, 2)) == SAVE_EXPR))
6348 /* See if this can be inverted. If it can't, possibly because
6349 it was a floating-point inequality comparison, don't do
6351 tem = invert_truthvalue (arg0);
6353 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
6355 t = build (code, type, tem,
6356 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
6358 /* arg1 should be the first argument of the new T. */
6359 arg1 = TREE_OPERAND (t, 1);
6364 /* Convert A ? 1 : 0 to simply A. */
6365 if (integer_onep (TREE_OPERAND (t, 1))
6366 && integer_zerop (TREE_OPERAND (t, 2))
6367 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
6368 call to fold will try to move the conversion inside
6369 a COND, which will recurse. In that case, the COND_EXPR
6370 is probably the best choice, so leave it alone. */
6371 && type == TREE_TYPE (arg0))
6372 return pedantic_non_lvalue (arg0);
6374 /* Look for expressions of the form A & 2 ? 2 : 0. The result of this
6375 operation is simply A & 2. */
6377 if (integer_zerop (TREE_OPERAND (t, 2))
6378 && TREE_CODE (arg0) == NE_EXPR
6379 && integer_zerop (TREE_OPERAND (arg0, 1))
6380 && integer_pow2p (arg1)
6381 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
6382 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
6384 return pedantic_non_lvalue (convert (type, TREE_OPERAND (arg0, 0)));
6389 /* When pedantic, a compound expression can be neither an lvalue
6390 nor an integer constant expression. */
6391 if (TREE_SIDE_EFFECTS (arg0) || pedantic)
6393 /* Don't let (0, 0) be null pointer constant. */
6394 if (integer_zerop (arg1))
6395 return build1 (NOP_EXPR, TREE_TYPE (arg1), arg1);
6400 return build_complex (type, arg0, arg1);
6404 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
6406 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
6407 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
6408 TREE_OPERAND (arg0, 1));
6409 else if (TREE_CODE (arg0) == COMPLEX_CST)
6410 return TREE_REALPART (arg0);
6411 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
6412 return fold (build (TREE_CODE (arg0), type,
6413 fold (build1 (REALPART_EXPR, type,
6414 TREE_OPERAND (arg0, 0))),
6415 fold (build1 (REALPART_EXPR,
6416 type, TREE_OPERAND (arg0, 1)))));
6420 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
6421 return convert (type, integer_zero_node);
6422 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
6423 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
6424 TREE_OPERAND (arg0, 0));
6425 else if (TREE_CODE (arg0) == COMPLEX_CST)
6426 return TREE_IMAGPART (arg0);
6427 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
6428 return fold (build (TREE_CODE (arg0), type,
6429 fold (build1 (IMAGPART_EXPR, type,
6430 TREE_OPERAND (arg0, 0))),
6431 fold (build1 (IMAGPART_EXPR, type,
6432 TREE_OPERAND (arg0, 1)))));
6435 /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
6437 case CLEANUP_POINT_EXPR:
6438 if (! has_cleanups (arg0))
6439 return TREE_OPERAND (t, 0);
6442 enum tree_code code0 = TREE_CODE (arg0);
6443 int kind0 = TREE_CODE_CLASS (code0);
6444 tree arg00 = TREE_OPERAND (arg0, 0);
6447 if (kind0 == '1' || code0 == TRUTH_NOT_EXPR)
6448 return fold (build1 (code0, type,
6449 fold (build1 (CLEANUP_POINT_EXPR,
6450 TREE_TYPE (arg00), arg00))));
6452 if (kind0 == '<' || kind0 == '2'
6453 || code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR
6454 || code0 == TRUTH_AND_EXPR || code0 == TRUTH_OR_EXPR
6455 || code0 == TRUTH_XOR_EXPR)
6457 arg01 = TREE_OPERAND (arg0, 1);
6459 if (TREE_CONSTANT (arg00)
6460 || ((code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR)
6461 && ! has_cleanups (arg00)))
6462 return fold (build (code0, type, arg00,
6463 fold (build1 (CLEANUP_POINT_EXPR,
6464 TREE_TYPE (arg01), arg01))));
6466 if (TREE_CONSTANT (arg01))
6467 return fold (build (code0, type,
6468 fold (build1 (CLEANUP_POINT_EXPR,
6469 TREE_TYPE (arg00), arg00)),
6478 } /* switch (code) */
6481 /* Determine if first argument is a multiple of second argument.
6482 Return 0 if it is not, or is not easily determined to so be.
6484 An example of the sort of thing we care about (at this point --
6485 this routine could surely be made more general, and expanded
6486 to do what the *_DIV_EXPR's fold() cases do now) is discovering
6489 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
6495 when we know that the two `SAVE_EXPR (J * 8)' nodes are the
6496 same node (which means they will have the same value at run
6497 time, even though we don't know when they'll be assigned).
6499 This code also handles discovering that
6501 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
6507 (of course) so we don't have to worry about dealing with a
6510 Note that we _look_ inside a SAVE_EXPR only to determine
6511 how it was calculated; it is not safe for fold() to do much
6512 of anything else with the internals of a SAVE_EXPR, since
6513 fold() cannot know when it will be evaluated at run time.
6514 For example, the latter example above _cannot_ be implemented
6519 or any variant thereof, since the value of J at evaluation time
6520 of the original SAVE_EXPR is not necessarily the same at the time
6521 the new expression is evaluated. The only optimization of this
6522 sort that would be valid is changing
6524 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
6530 SAVE_EXPR (I) * SAVE_EXPR (J)
6532 (where the same SAVE_EXPR (J) is used in the original and the
6533 transformed version). */
6536 multiple_of_p (type, top, bottom)
6541 if (operand_equal_p (top, bottom, 0))
6544 if (TREE_CODE (type) != INTEGER_TYPE)
6547 switch (TREE_CODE (top))
6550 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
6551 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
6555 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
6556 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
6559 /* Punt if conversion from non-integral or wider integral type. */
6560 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
6561 || (TYPE_PRECISION (type)
6562 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
6566 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
6569 if ((TREE_CODE (bottom) != INTEGER_CST)
6570 || (tree_int_cst_sgn (top) < 0)
6571 || (tree_int_cst_sgn (bottom) < 0))
6573 return integer_zerop (const_binop (TRUNC_MOD_EXPR,