1 /* Fold a constant sub-tree into a single node for C-compiler
2 Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000 Free Software Foundation, Inc.
5 This file is part of GNU CC.
7 GNU CC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
12 GNU CC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GNU CC; see the file COPYING. If not, write to
19 the Free Software Foundation, 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
22 /*@@ This file should be rewritten to use an arbitrary precision
23 @@ representation for "struct tree_int_cst" and "struct tree_real_cst".
24 @@ Perhaps the routines could also be used for bc/dc, and made a lib.
25 @@ The routines that translate from the ap rep should
26 @@ warn if precision et. al. is lost.
27 @@ This would also make life easier when this technology is used
28 @@ for cross-compilers. */
31 /* The entry points in this file are fold, size_int_wide, size_binop
34 fold takes a tree as argument and returns a simplified tree.
36 size_binop takes a tree code for an arithmetic operation
37 and two operands that are trees, and produces a tree for the
38 result, assuming the type comes from `sizetype'.
40 size_int takes an integer value, and creates a tree constant
41 with type from `sizetype'.
43 force_fit_type takes a constant and prior overflow indicator, and
44 forces the value to fit the type. It returns an overflow indicator. */
56 static void encode PARAMS ((HOST_WIDE_INT *,
57 HOST_WIDE_INT, HOST_WIDE_INT));
58 static void decode PARAMS ((HOST_WIDE_INT *,
59 HOST_WIDE_INT *, HOST_WIDE_INT *));
60 int div_and_round_double PARAMS ((enum tree_code, int, HOST_WIDE_INT,
61 HOST_WIDE_INT, HOST_WIDE_INT,
62 HOST_WIDE_INT, HOST_WIDE_INT *,
63 HOST_WIDE_INT *, HOST_WIDE_INT *,
65 static tree negate_expr PARAMS ((tree));
66 static tree split_tree PARAMS ((tree, enum tree_code, tree *, tree *,
68 static tree associate_trees PARAMS ((tree, tree, enum tree_code, tree));
69 static tree int_const_binop PARAMS ((enum tree_code, tree, tree, int, int));
70 static void const_binop_1 PARAMS ((PTR));
71 static tree const_binop PARAMS ((enum tree_code, tree, tree, int));
72 static void fold_convert_1 PARAMS ((PTR));
73 static tree fold_convert PARAMS ((tree, tree));
74 static enum tree_code invert_tree_comparison PARAMS ((enum tree_code));
75 static enum tree_code swap_tree_comparison PARAMS ((enum tree_code));
76 static int truth_value_p PARAMS ((enum tree_code));
77 static int operand_equal_for_comparison_p PARAMS ((tree, tree, tree));
78 static int twoval_comparison_p PARAMS ((tree, tree *, tree *, int *));
79 static tree eval_subst PARAMS ((tree, tree, tree, tree, tree));
80 static tree omit_one_operand PARAMS ((tree, tree, tree));
81 static tree pedantic_omit_one_operand PARAMS ((tree, tree, tree));
82 static tree distribute_bit_expr PARAMS ((enum tree_code, tree, tree, tree));
83 static tree make_bit_field_ref PARAMS ((tree, tree, int, int, int));
84 static tree optimize_bit_field_compare PARAMS ((enum tree_code, tree,
86 static tree decode_field_reference PARAMS ((tree, int *, int *,
87 enum machine_mode *, int *,
88 int *, tree *, tree *));
89 static int all_ones_mask_p PARAMS ((tree, int));
90 static int simple_operand_p PARAMS ((tree));
91 static tree range_binop PARAMS ((enum tree_code, tree, tree, int,
93 static tree make_range PARAMS ((tree, int *, tree *, tree *));
94 static tree build_range_check PARAMS ((tree, tree, int, tree, tree));
95 static int merge_ranges PARAMS ((int *, tree *, tree *, int, tree, tree,
97 static tree fold_range_test PARAMS ((tree));
98 static tree unextend PARAMS ((tree, int, int, tree));
99 static tree fold_truthop PARAMS ((enum tree_code, tree, tree, tree));
100 static tree optimize_minmax_comparison PARAMS ((tree));
101 static tree extract_muldiv PARAMS ((tree, tree, enum tree_code, tree));
102 static tree strip_compound_expr PARAMS ((tree, tree));
103 static int multiple_of_p PARAMS ((tree, tree, tree));
104 static tree constant_boolean_node PARAMS ((int, tree));
105 static int count_cond PARAMS ((tree, int));
108 #define BRANCH_COST 1
111 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
112 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
113 and SUM1. Then this yields nonzero if overflow occurred during the
116 Overflow occurs if A and B have the same sign, but A and SUM differ in
117 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
119 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
121 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
122 We do that by representing the two-word integer in 4 words, with only
123 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
124 number. The value of the word is LOWPART + HIGHPART * BASE. */
127 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
128 #define HIGHPART(x) \
129 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
130 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
132 /* Unpack a two-word integer into 4 words.
133 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
134 WORDS points to the array of HOST_WIDE_INTs. */
137 encode (words, low, hi)
138 HOST_WIDE_INT *words;
139 HOST_WIDE_INT low, hi;
141 words[0] = LOWPART (low);
142 words[1] = HIGHPART (low);
143 words[2] = LOWPART (hi);
144 words[3] = HIGHPART (hi);
147 /* Pack an array of 4 words into a two-word integer.
148 WORDS points to the array of words.
149 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
152 decode (words, low, hi)
153 HOST_WIDE_INT *words;
154 HOST_WIDE_INT *low, *hi;
156 *low = words[0] + words[1] * BASE;
157 *hi = words[2] + words[3] * BASE;
160 /* Make the integer constant T valid for its type by setting to 0 or 1 all
161 the bits in the constant that don't belong in the type.
163 Return 1 if a signed overflow occurs, 0 otherwise. If OVERFLOW is
164 nonzero, a signed overflow has already occurred in calculating T, so
167 Make the real constant T valid for its type by calling CHECK_FLOAT_VALUE,
171 force_fit_type (t, overflow)
175 HOST_WIDE_INT low, high;
178 if (TREE_CODE (t) == REAL_CST)
180 #ifdef CHECK_FLOAT_VALUE
181 CHECK_FLOAT_VALUE (TYPE_MODE (TREE_TYPE (t)), TREE_REAL_CST (t),
187 else if (TREE_CODE (t) != INTEGER_CST)
190 low = TREE_INT_CST_LOW (t);
191 high = TREE_INT_CST_HIGH (t);
193 if (POINTER_TYPE_P (TREE_TYPE (t)))
196 prec = TYPE_PRECISION (TREE_TYPE (t));
198 /* First clear all bits that are beyond the type's precision. */
200 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
202 else if (prec > HOST_BITS_PER_WIDE_INT)
203 TREE_INT_CST_HIGH (t)
204 &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
207 TREE_INT_CST_HIGH (t) = 0;
208 if (prec < HOST_BITS_PER_WIDE_INT)
209 TREE_INT_CST_LOW (t) &= ~((HOST_WIDE_INT) (-1) << prec);
212 /* Unsigned types do not suffer sign extension or overflow. */
213 if (TREE_UNSIGNED (TREE_TYPE (t)))
216 /* If the value's sign bit is set, extend the sign. */
217 if (prec != 2 * HOST_BITS_PER_WIDE_INT
218 && (prec > HOST_BITS_PER_WIDE_INT
219 ? (TREE_INT_CST_HIGH (t)
220 & ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)))
221 : TREE_INT_CST_LOW (t) & ((HOST_WIDE_INT) 1 << (prec - 1))))
223 /* Value is negative:
224 set to 1 all the bits that are outside this type's precision. */
225 if (prec > HOST_BITS_PER_WIDE_INT)
226 TREE_INT_CST_HIGH (t)
227 |= ((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
230 TREE_INT_CST_HIGH (t) = -1;
231 if (prec < HOST_BITS_PER_WIDE_INT)
232 TREE_INT_CST_LOW (t) |= ((HOST_WIDE_INT) (-1) << prec);
236 /* Return nonzero if signed overflow occurred. */
238 ((overflow | (low ^ TREE_INT_CST_LOW (t)) | (high ^ TREE_INT_CST_HIGH (t)))
242 /* Add two doubleword integers with doubleword result.
243 Each argument is given as two `HOST_WIDE_INT' pieces.
244 One argument is L1 and H1; the other, L2 and H2.
245 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
248 add_double (l1, h1, l2, h2, lv, hv)
249 HOST_WIDE_INT l1, h1, l2, h2;
250 HOST_WIDE_INT *lv, *hv;
255 h = h1 + h2 + ((unsigned HOST_WIDE_INT) l < (unsigned HOST_WIDE_INT) l1);
259 return OVERFLOW_SUM_SIGN (h1, h2, h);
262 /* Negate a doubleword integer with doubleword result.
263 Return nonzero if the operation overflows, assuming it's signed.
264 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
265 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
268 neg_double (l1, h1, lv, hv)
269 HOST_WIDE_INT l1, h1;
270 HOST_WIDE_INT *lv, *hv;
276 return (*hv & h1) < 0;
286 /* Multiply two doubleword integers with doubleword result.
287 Return nonzero if the operation overflows, assuming it's signed.
288 Each argument is given as two `HOST_WIDE_INT' pieces.
289 One argument is L1 and H1; the other, L2 and H2.
290 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
293 mul_double (l1, h1, l2, h2, lv, hv)
294 HOST_WIDE_INT l1, h1, l2, h2;
295 HOST_WIDE_INT *lv, *hv;
297 HOST_WIDE_INT arg1[4];
298 HOST_WIDE_INT arg2[4];
299 HOST_WIDE_INT prod[4 * 2];
300 register unsigned HOST_WIDE_INT carry;
301 register int i, j, k;
302 HOST_WIDE_INT toplow, tophigh, neglow, neghigh;
304 encode (arg1, l1, h1);
305 encode (arg2, l2, h2);
307 bzero ((char *) prod, sizeof prod);
309 for (i = 0; i < 4; i++)
312 for (j = 0; j < 4; j++)
315 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
316 carry += arg1[i] * arg2[j];
317 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
319 prod[k] = LOWPART (carry);
320 carry = HIGHPART (carry);
325 decode (prod, lv, hv); /* This ignores prod[4] through prod[4*2-1] */
327 /* Check for overflow by calculating the top half of the answer in full;
328 it should agree with the low half's sign bit. */
329 decode (prod+4, &toplow, &tophigh);
332 neg_double (l2, h2, &neglow, &neghigh);
333 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
337 neg_double (l1, h1, &neglow, &neghigh);
338 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
340 return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
343 /* Shift the doubleword integer in L1, H1 left by COUNT places
344 keeping only PREC bits of result.
345 Shift right if COUNT is negative.
346 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
347 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
350 lshift_double (l1, h1, count, prec, lv, hv, arith)
351 HOST_WIDE_INT l1, h1, count;
353 HOST_WIDE_INT *lv, *hv;
358 rshift_double (l1, h1, - count, prec, lv, hv, arith);
362 #ifdef SHIFT_COUNT_TRUNCATED
363 if (SHIFT_COUNT_TRUNCATED)
367 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
369 /* Shifting by the host word size is undefined according to the
370 ANSI standard, so we must handle this as a special case. */
374 else if (count >= HOST_BITS_PER_WIDE_INT)
376 *hv = (unsigned HOST_WIDE_INT) l1 << (count - HOST_BITS_PER_WIDE_INT);
381 *hv = (((unsigned HOST_WIDE_INT) h1 << count)
382 | ((unsigned HOST_WIDE_INT) l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
383 *lv = (unsigned HOST_WIDE_INT) l1 << count;
387 /* Shift the doubleword integer in L1, H1 right by COUNT places
388 keeping only PREC bits of result. COUNT must be positive.
389 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
390 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
393 rshift_double (l1, h1, count, prec, lv, hv, arith)
394 HOST_WIDE_INT l1, h1, count;
395 int prec ATTRIBUTE_UNUSED;
396 HOST_WIDE_INT *lv, *hv;
399 unsigned HOST_WIDE_INT signmask;
401 ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
404 #ifdef SHIFT_COUNT_TRUNCATED
405 if (SHIFT_COUNT_TRUNCATED)
409 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
411 /* Shifting by the host word size is undefined according to the
412 ANSI standard, so we must handle this as a special case. */
416 else if (count >= HOST_BITS_PER_WIDE_INT)
419 *lv = ((signmask << (2 * HOST_BITS_PER_WIDE_INT - count - 1) << 1)
420 | ((unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT)));
424 *lv = (((unsigned HOST_WIDE_INT) l1 >> count)
425 | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
426 *hv = ((signmask << (HOST_BITS_PER_WIDE_INT - count))
427 | ((unsigned HOST_WIDE_INT) h1 >> count));
431 /* Rotate the doubleword integer in L1, H1 left by COUNT places
432 keeping only PREC bits of result.
433 Rotate right if COUNT is negative.
434 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
437 lrotate_double (l1, h1, count, prec, lv, hv)
438 HOST_WIDE_INT l1, h1, count;
440 HOST_WIDE_INT *lv, *hv;
442 HOST_WIDE_INT s1l, s1h, s2l, s2h;
448 lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
449 rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
454 /* Rotate the doubleword integer in L1, H1 left by COUNT places
455 keeping only PREC bits of result. COUNT must be positive.
456 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
459 rrotate_double (l1, h1, count, prec, lv, hv)
460 HOST_WIDE_INT l1, h1, count;
462 HOST_WIDE_INT *lv, *hv;
464 HOST_WIDE_INT s1l, s1h, s2l, s2h;
470 rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
471 lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
476 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
477 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
478 CODE is a tree code for a kind of division, one of
479 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
481 It controls how the quotient is rounded to a integer.
482 Return nonzero if the operation overflows.
483 UNS nonzero says do unsigned division. */
486 div_and_round_double (code, uns,
487 lnum_orig, hnum_orig, lden_orig, hden_orig,
488 lquo, hquo, lrem, hrem)
491 HOST_WIDE_INT lnum_orig, hnum_orig; /* num == numerator == dividend */
492 HOST_WIDE_INT lden_orig, hden_orig; /* den == denominator == divisor */
493 HOST_WIDE_INT *lquo, *hquo, *lrem, *hrem;
496 HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
497 HOST_WIDE_INT den[4], quo[4];
499 unsigned HOST_WIDE_INT work;
500 register unsigned HOST_WIDE_INT carry = 0;
501 HOST_WIDE_INT lnum = lnum_orig;
502 HOST_WIDE_INT hnum = hnum_orig;
503 HOST_WIDE_INT lden = lden_orig;
504 HOST_WIDE_INT hden = hden_orig;
507 if ((hden == 0) && (lden == 0))
508 overflow = 1, lden = 1;
510 /* calculate quotient sign and convert operands to unsigned. */
516 /* (minimum integer) / (-1) is the only overflow case. */
517 if (neg_double (lnum, hnum, &lnum, &hnum) && (lden & hden) == -1)
523 neg_double (lden, hden, &lden, &hden);
527 if (hnum == 0 && hden == 0)
528 { /* single precision */
530 /* This unsigned division rounds toward zero. */
531 *lquo = lnum / (unsigned HOST_WIDE_INT) lden;
536 { /* trivial case: dividend < divisor */
537 /* hden != 0 already checked. */
544 bzero ((char *) quo, sizeof quo);
546 bzero ((char *) num, sizeof num); /* to zero 9th element */
547 bzero ((char *) den, sizeof den);
549 encode (num, lnum, hnum);
550 encode (den, lden, hden);
552 /* Special code for when the divisor < BASE. */
553 if (hden == 0 && lden < (HOST_WIDE_INT) BASE)
555 /* hnum != 0 already checked. */
556 for (i = 4 - 1; i >= 0; i--)
558 work = num[i] + carry * BASE;
559 quo[i] = work / (unsigned HOST_WIDE_INT) lden;
560 carry = work % (unsigned HOST_WIDE_INT) lden;
565 /* Full double precision division,
566 with thanks to Don Knuth's "Seminumerical Algorithms". */
567 int num_hi_sig, den_hi_sig;
568 unsigned HOST_WIDE_INT quo_est, scale;
570 /* Find the highest non-zero divisor digit. */
571 for (i = 4 - 1; ; i--)
577 /* Insure that the first digit of the divisor is at least BASE/2.
578 This is required by the quotient digit estimation algorithm. */
580 scale = BASE / (den[den_hi_sig] + 1);
581 if (scale > 1) { /* scale divisor and dividend */
583 for (i = 0; i <= 4 - 1; i++) {
584 work = (num[i] * scale) + carry;
585 num[i] = LOWPART (work);
586 carry = HIGHPART (work);
589 for (i = 0; i <= 4 - 1; i++) {
590 work = (den[i] * scale) + carry;
591 den[i] = LOWPART (work);
592 carry = HIGHPART (work);
593 if (den[i] != 0) den_hi_sig = i;
600 for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--) {
601 /* guess the next quotient digit, quo_est, by dividing the first
602 two remaining dividend digits by the high order quotient digit.
603 quo_est is never low and is at most 2 high. */
604 unsigned HOST_WIDE_INT tmp;
606 num_hi_sig = i + den_hi_sig + 1;
607 work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
608 if (num[num_hi_sig] != den[den_hi_sig])
609 quo_est = work / den[den_hi_sig];
613 /* refine quo_est so it's usually correct, and at most one high. */
614 tmp = work - quo_est * den[den_hi_sig];
616 && den[den_hi_sig - 1] * quo_est > (tmp * BASE + num[num_hi_sig - 2]))
619 /* Try QUO_EST as the quotient digit, by multiplying the
620 divisor by QUO_EST and subtracting from the remaining dividend.
621 Keep in mind that QUO_EST is the I - 1st digit. */
624 for (j = 0; j <= den_hi_sig; j++)
626 work = quo_est * den[j] + carry;
627 carry = HIGHPART (work);
628 work = num[i + j] - LOWPART (work);
629 num[i + j] = LOWPART (work);
630 carry += HIGHPART (work) != 0;
633 /* if quo_est was high by one, then num[i] went negative and
634 we need to correct things. */
636 if (num[num_hi_sig] < carry)
639 carry = 0; /* add divisor back in */
640 for (j = 0; j <= den_hi_sig; j++)
642 work = num[i + j] + den[j] + carry;
643 carry = HIGHPART (work);
644 num[i + j] = LOWPART (work);
646 num [num_hi_sig] += carry;
649 /* store the quotient digit. */
654 decode (quo, lquo, hquo);
657 /* if result is negative, make it so. */
659 neg_double (*lquo, *hquo, lquo, hquo);
661 /* compute trial remainder: rem = num - (quo * den) */
662 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
663 neg_double (*lrem, *hrem, lrem, hrem);
664 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
669 case TRUNC_MOD_EXPR: /* round toward zero */
670 case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
674 case FLOOR_MOD_EXPR: /* round toward negative infinity */
675 if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
678 add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
681 else return overflow;
685 case CEIL_MOD_EXPR: /* round toward positive infinity */
686 if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
688 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
691 else return overflow;
695 case ROUND_MOD_EXPR: /* round to closest integer */
697 HOST_WIDE_INT labs_rem = *lrem, habs_rem = *hrem;
698 HOST_WIDE_INT labs_den = lden, habs_den = hden, ltwice, htwice;
700 /* get absolute values */
701 if (*hrem < 0) neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
702 if (hden < 0) neg_double (lden, hden, &labs_den, &habs_den);
704 /* if (2 * abs (lrem) >= abs (lden)) */
705 mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
706 labs_rem, habs_rem, <wice, &htwice);
707 if (((unsigned HOST_WIDE_INT) habs_den
708 < (unsigned HOST_WIDE_INT) htwice)
709 || (((unsigned HOST_WIDE_INT) habs_den
710 == (unsigned HOST_WIDE_INT) htwice)
711 && ((HOST_WIDE_INT unsigned) labs_den
712 < (unsigned HOST_WIDE_INT) ltwice)))
716 add_double (*lquo, *hquo,
717 (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
720 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
723 else return overflow;
731 /* compute true remainder: rem = num - (quo * den) */
732 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
733 neg_double (*lrem, *hrem, lrem, hrem);
734 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
738 #ifndef REAL_ARITHMETIC
739 /* Effectively truncate a real value to represent the nearest possible value
740 in a narrower mode. The result is actually represented in the same data
741 type as the argument, but its value is usually different.
743 A trap may occur during the FP operations and it is the responsibility
744 of the calling function to have a handler established. */
747 real_value_truncate (mode, arg)
748 enum machine_mode mode;
751 return REAL_VALUE_TRUNCATE (mode, arg);
754 #if TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
756 /* Check for infinity in an IEEE double precision number. */
762 /* The IEEE 64-bit double format. */
767 unsigned exponent : 11;
768 unsigned mantissa1 : 20;
773 unsigned mantissa1 : 20;
774 unsigned exponent : 11;
780 if (u.big_endian.sign == 1)
783 return (u.big_endian.exponent == 2047
784 && u.big_endian.mantissa1 == 0
785 && u.big_endian.mantissa2 == 0);
790 return (u.little_endian.exponent == 2047
791 && u.little_endian.mantissa1 == 0
792 && u.little_endian.mantissa2 == 0);
796 /* Check whether an IEEE double precision number is a NaN. */
802 /* The IEEE 64-bit double format. */
807 unsigned exponent : 11;
808 unsigned mantissa1 : 20;
813 unsigned mantissa1 : 20;
814 unsigned exponent : 11;
820 if (u.big_endian.sign == 1)
823 return (u.big_endian.exponent == 2047
824 && (u.big_endian.mantissa1 != 0
825 || u.big_endian.mantissa2 != 0));
830 return (u.little_endian.exponent == 2047
831 && (u.little_endian.mantissa1 != 0
832 || u.little_endian.mantissa2 != 0));
836 /* Check for a negative IEEE double precision number. */
842 /* The IEEE 64-bit double format. */
847 unsigned exponent : 11;
848 unsigned mantissa1 : 20;
853 unsigned mantissa1 : 20;
854 unsigned exponent : 11;
860 if (u.big_endian.sign == 1)
863 return u.big_endian.sign;
868 return u.little_endian.sign;
871 #else /* Target not IEEE */
873 /* Let's assume other float formats don't have infinity.
874 (This can be overridden by redefining REAL_VALUE_ISINF.) */
878 REAL_VALUE_TYPE x ATTRIBUTE_UNUSED;
883 /* Let's assume other float formats don't have NaNs.
884 (This can be overridden by redefining REAL_VALUE_ISNAN.) */
888 REAL_VALUE_TYPE x ATTRIBUTE_UNUSED;
893 /* Let's assume other float formats don't have minus zero.
894 (This can be overridden by redefining REAL_VALUE_NEGATIVE.) */
902 #endif /* Target not IEEE */
904 /* Try to change R into its exact multiplicative inverse in machine mode
905 MODE. Return nonzero function value if successful. */
908 exact_real_inverse (mode, r)
909 enum machine_mode mode;
918 #ifdef CHECK_FLOAT_VALUE
922 /* Usually disable if bounds checks are not reliable. */
923 if ((HOST_FLOAT_FORMAT != TARGET_FLOAT_FORMAT) && !flag_pretend_float)
926 /* Set array index to the less significant bits in the unions, depending
927 on the endian-ness of the host doubles.
928 Disable if insufficient information on the data structure. */
929 #if HOST_FLOAT_FORMAT == UNKNOWN_FLOAT_FORMAT
932 #if HOST_FLOAT_FORMAT == VAX_FLOAT_FORMAT
935 #if HOST_FLOAT_FORMAT == IBM_FLOAT_FORMAT
938 #define K (2 * HOST_FLOAT_WORDS_BIG_ENDIAN)
943 if (setjmp (float_error))
945 /* Don't do the optimization if there was an arithmetic error. */
947 set_float_handler (NULL_PTR);
950 set_float_handler (float_error);
952 /* Domain check the argument. */
958 if (REAL_VALUE_ISINF (x.d) || REAL_VALUE_ISNAN (x.d))
962 /* Compute the reciprocal and check for numerical exactness.
963 It is unnecessary to check all the significand bits to determine
964 whether X is a power of 2. If X is not, then it is impossible for
965 the bottom half significand of both X and 1/X to be all zero bits.
966 Hence we ignore the data structure of the top half and examine only
967 the low order bits of the two significands. */
969 if (x.i[K] != 0 || x.i[K + 1] != 0 || t.i[K] != 0 || t.i[K + 1] != 0)
972 /* Truncate to the required mode and range-check the result. */
973 y.d = REAL_VALUE_TRUNCATE (mode, t.d);
974 #ifdef CHECK_FLOAT_VALUE
976 if (CHECK_FLOAT_VALUE (mode, y.d, i))
980 /* Fail if truncation changed the value. */
981 if (y.d != t.d || y.d == 0.0)
985 if (REAL_VALUE_ISINF (y.d) || REAL_VALUE_ISNAN (y.d))
989 /* Output the reciprocal and return success flag. */
990 set_float_handler (NULL_PTR);
995 /* Convert C9X hexadecimal floating point string constant S. Return
996 real value type in mode MODE. This function uses the host computer's
997 floating point arithmetic when there is no REAL_ARITHMETIC. */
1000 real_hex_to_f (s, mode)
1002 enum machine_mode mode;
1006 unsigned HOST_WIDE_INT low, high;
1007 int shcount, nrmcount, k;
1008 int sign, expsign, isfloat;
1009 int lost = 0;/* Nonzero low order bits shifted out and discarded. */
1010 int frexpon = 0; /* Bits after the decimal point. */
1011 int expon = 0; /* Value of exponent. */
1012 int decpt = 0; /* How many decimal points. */
1013 int gotp = 0; /* How many P's. */
1020 while (*p == ' ' || *p == '\t')
1023 /* Sign, if any, comes first. */
1031 /* The string is supposed to start with 0x or 0X . */
1035 if (*p == 'x' || *p == 'X')
1049 while ((c = *p) != '\0')
1051 if ((c >= '0' && c <= '9') || (c >= 'A' && c <= 'F')
1052 || (c >= 'a' && c <= 'f'))
1062 if ((high & 0xf0000000) == 0)
1064 high = (high << 4) + ((low >> 28) & 15);
1065 low = (low << 4) + k;
1072 /* Record nonzero lost bits. */
1085 else if (c == 'p' || c == 'P')
1089 /* Sign of exponent. */
1096 /* Value of exponent.
1097 The exponent field is a decimal integer. */
1100 k = (*p++ & 0x7f) - '0';
1101 expon = 10 * expon + k;
1105 /* F suffix is ambiguous in the significand part
1106 so it must appear after the decimal exponent field. */
1107 if (*p == 'f' || *p == 'F')
1115 else if (c == 'l' || c == 'L')
1124 /* Abort if last character read was not legitimate. */
1126 if ((c != '\0' && c != ' ' && c != '\n' && c != '\r') || (decpt > 1))
1129 /* There must be either one decimal point or one p. */
1130 if (decpt == 0 && gotp == 0)
1134 if (high == 0 && low == 0)
1146 /* Leave a high guard bit for carry-out. */
1147 if ((high & 0x80000000) != 0)
1150 low = (low >> 1) | (high << 31);
1155 if ((high & 0xffff8000) == 0)
1157 high = (high << 16) + ((low >> 16) & 0xffff);
1162 while ((high & 0xc0000000) == 0)
1164 high = (high << 1) + ((low >> 31) & 1);
1169 if (isfloat || GET_MODE_SIZE(mode) == UNITS_PER_WORD)
1171 /* Keep 24 bits precision, bits 0x7fffff80.
1172 Rounding bit is 0x40. */
1173 lost = lost | low | (high & 0x3f);
1177 if ((high & 0x80) || lost)
1184 /* We need real.c to do long double formats, so here default
1185 to double precision. */
1186 #if HOST_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
1188 Keep 53 bits precision, bits 0x7fffffff fffffc00.
1189 Rounding bit is low word 0x200. */
1190 lost = lost | (low & 0x1ff);
1193 if ((low & 0x400) || lost)
1195 low = (low + 0x200) & 0xfffffc00;
1202 /* Assume it's a VAX with 56-bit significand,
1203 bits 0x7fffffff ffffff80. */
1204 lost = lost | (low & 0x7f);
1207 if ((low & 0x80) || lost)
1209 low = (low + 0x40) & 0xffffff80;
1219 ip = REAL_VALUE_LDEXP (ip, 32) + (double) low;
1220 /* Apply shifts and exponent value as power of 2. */
1221 ip = REAL_VALUE_LDEXP (ip, expon - (nrmcount + frexpon));
1228 #endif /* no REAL_ARITHMETIC */
1230 /* Given T, an expression, return the negation of T. Allow for T to be
1231 null, in which case return null. */
1243 type = TREE_TYPE (t);
1244 STRIP_SIGN_NOPS (t);
1246 switch (TREE_CODE (t))
1250 if (! TREE_UNSIGNED (type)
1251 && 0 != (tem = fold (build1 (NEGATE_EXPR, type, t)))
1252 && ! TREE_OVERFLOW (tem))
1257 return convert (type, TREE_OPERAND (t, 0));
1260 /* - (A - B) -> B - A */
1261 if (! FLOAT_TYPE_P (type) || flag_fast_math)
1262 return convert (type,
1263 fold (build (MINUS_EXPR, TREE_TYPE (t),
1264 TREE_OPERAND (t, 1),
1265 TREE_OPERAND (t, 0))));
1272 return convert (type, build1 (NEGATE_EXPR, TREE_TYPE (t), t));
1275 /* Split a tree IN into a constant, literal and variable parts that could be
1276 combined with CODE to make IN. "constant" means an expression with
1277 TREE_CONSTANT but that isn't an actual constant. CODE must be a
1278 commutative arithmetic operation. Store the constant part into *CONP,
1279 the literal in &LITP and return the variable part. If a part isn't
1280 present, set it to null. If the tree does not decompose in this way,
1281 return the entire tree as the variable part and the other parts as null.
1283 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
1284 case, we negate an operand that was subtracted. If NEGATE_P is true, we
1285 are negating all of IN.
1287 If IN is itself a literal or constant, return it as appropriate.
1289 Note that we do not guarantee that any of the three values will be the
1290 same type as IN, but they will have the same signedness and mode. */
1293 split_tree (in, code, conp, litp, negate_p)
1295 enum tree_code code;
1304 /* Strip any conversions that don't change the machine mode or signedness. */
1305 STRIP_SIGN_NOPS (in);
1307 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST)
1309 else if (TREE_CONSTANT (in))
1312 else if (TREE_CODE (in) == code
1313 || (! FLOAT_TYPE_P (TREE_TYPE (in))
1314 /* We can associate addition and subtraction together (even
1315 though the C standard doesn't say so) for integers because
1316 the value is not affected. For reals, the value might be
1317 affected, so we can't. */
1318 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
1319 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
1321 tree op0 = TREE_OPERAND (in, 0);
1322 tree op1 = TREE_OPERAND (in, 1);
1323 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
1324 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
1326 /* First see if either of the operands is a literal, then a constant. */
1327 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
1328 *litp = op0, op0 = 0;
1329 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST)
1330 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
1332 if (op0 != 0 && TREE_CONSTANT (op0))
1333 *conp = op0, op0 = 0;
1334 else if (op1 != 0 && TREE_CONSTANT (op1))
1335 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
1337 /* If we haven't dealt with either operand, this is not a case we can
1338 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1339 if (op0 != 0 && op1 != 0)
1344 var = op1, neg_var_p = neg1_p;
1346 /* Now do any needed negations. */
1347 if (neg_litp_p) *litp = negate_expr (*litp);
1348 if (neg_conp_p) *conp = negate_expr (*conp);
1349 if (neg_var_p) var = negate_expr (var);
1356 var = negate_expr (var);
1357 *conp = negate_expr (*conp);
1358 *litp = negate_expr (*litp);
1364 /* Re-associate trees split by the above function. T1 and T2 are either
1365 expressions to associate or null. Return the new expression, if any. If
1366 we build an operation, do it in TYPE and with CODE, except if CODE is a
1367 MINUS_EXPR, in which case we use PLUS_EXPR since split_tree will already
1368 have taken care of the negations. */
1371 associate_trees (t1, t2, code, type)
1373 enum tree_code code;
1381 if (code == MINUS_EXPR)
1384 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1385 try to fold this since we will have infinite recursion. But do
1386 deal with any NEGATE_EXPRs. */
1387 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
1388 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1390 if (TREE_CODE (t1) == NEGATE_EXPR)
1391 return build (MINUS_EXPR, type, convert (type, t2),
1392 convert (type, TREE_OPERAND (t1, 0)));
1393 else if (TREE_CODE (t2) == NEGATE_EXPR)
1394 return build (MINUS_EXPR, type, convert (type, t1),
1395 convert (type, TREE_OPERAND (t2, 0)));
1397 return build (code, type, convert (type, t1), convert (type, t2));
1400 return fold (build (code, type, convert (type, t1), convert (type, t2)));
1403 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1404 to produce a new constant.
1406 If NOTRUNC is nonzero, do not truncate the result to fit the data type.
1407 If FORSIZE is nonzero, compute overflow for unsigned types. */
1410 int_const_binop (code, arg1, arg2, notrunc, forsize)
1411 enum tree_code code;
1412 register tree arg1, arg2;
1413 int notrunc, forsize;
1415 HOST_WIDE_INT int1l, int1h, int2l, int2h;
1416 HOST_WIDE_INT low, hi;
1417 HOST_WIDE_INT garbagel, garbageh;
1419 int uns = TREE_UNSIGNED (TREE_TYPE (arg1));
1421 int no_overflow = 0;
1423 int1l = TREE_INT_CST_LOW (arg1);
1424 int1h = TREE_INT_CST_HIGH (arg1);
1425 int2l = TREE_INT_CST_LOW (arg2);
1426 int2h = TREE_INT_CST_HIGH (arg2);
1431 low = int1l | int2l, hi = int1h | int2h;
1435 low = int1l ^ int2l, hi = int1h ^ int2h;
1439 low = int1l & int2l, hi = int1h & int2h;
1442 case BIT_ANDTC_EXPR:
1443 low = int1l & ~int2l, hi = int1h & ~int2h;
1449 /* It's unclear from the C standard whether shifts can overflow.
1450 The following code ignores overflow; perhaps a C standard
1451 interpretation ruling is needed. */
1452 lshift_double (int1l, int1h, int2l,
1453 TYPE_PRECISION (TREE_TYPE (arg1)),
1462 lrotate_double (int1l, int1h, int2l,
1463 TYPE_PRECISION (TREE_TYPE (arg1)),
1468 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1472 neg_double (int2l, int2h, &low, &hi);
1473 add_double (int1l, int1h, low, hi, &low, &hi);
1474 overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
1478 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1481 case TRUNC_DIV_EXPR:
1482 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1483 case EXACT_DIV_EXPR:
1484 /* This is a shortcut for a common special case. */
1485 if (int2h == 0 && int2l > 0
1486 && ! TREE_CONSTANT_OVERFLOW (arg1)
1487 && ! TREE_CONSTANT_OVERFLOW (arg2)
1488 && int1h == 0 && int1l >= 0)
1490 if (code == CEIL_DIV_EXPR)
1492 low = int1l / int2l, hi = 0;
1496 /* ... fall through ... */
1498 case ROUND_DIV_EXPR:
1499 if (int2h == 0 && int2l == 1)
1501 low = int1l, hi = int1h;
1504 if (int1l == int2l && int1h == int2h
1505 && ! (int1l == 0 && int1h == 0))
1510 overflow = div_and_round_double (code, uns,
1511 int1l, int1h, int2l, int2h,
1512 &low, &hi, &garbagel, &garbageh);
1515 case TRUNC_MOD_EXPR:
1516 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1517 /* This is a shortcut for a common special case. */
1518 if (int2h == 0 && int2l > 0
1519 && ! TREE_CONSTANT_OVERFLOW (arg1)
1520 && ! TREE_CONSTANT_OVERFLOW (arg2)
1521 && int1h == 0 && int1l >= 0)
1523 if (code == CEIL_MOD_EXPR)
1525 low = int1l % int2l, hi = 0;
1529 /* ... fall through ... */
1531 case ROUND_MOD_EXPR:
1532 overflow = div_and_round_double (code, uns,
1533 int1l, int1h, int2l, int2h,
1534 &garbagel, &garbageh, &low, &hi);
1540 low = (((unsigned HOST_WIDE_INT) int1h
1541 < (unsigned HOST_WIDE_INT) int2h)
1542 || (((unsigned HOST_WIDE_INT) int1h
1543 == (unsigned HOST_WIDE_INT) int2h)
1544 && ((unsigned HOST_WIDE_INT) int1l
1545 < (unsigned HOST_WIDE_INT) int2l)));
1547 low = ((int1h < int2h)
1548 || ((int1h == int2h)
1549 && ((unsigned HOST_WIDE_INT) int1l
1550 < (unsigned HOST_WIDE_INT) int2l)));
1552 if (low == (code == MIN_EXPR))
1553 low = int1l, hi = int1h;
1555 low = int2l, hi = int2h;
1562 if (forsize && hi == 0 && low >= 0 && low < 1000)
1563 return size_int_type_wide (low, TREE_TYPE (arg1));
1566 t = build_int_2 (low, hi);
1567 TREE_TYPE (t) = TREE_TYPE (arg1);
1571 = ((notrunc ? (!uns || forsize) && overflow
1572 : force_fit_type (t, (!uns || forsize) && overflow) && ! no_overflow)
1573 | TREE_OVERFLOW (arg1)
1574 | TREE_OVERFLOW (arg2));
1576 /* If we're doing a size calculation, unsigned arithmetic does overflow.
1577 So check if force_fit_type truncated the value. */
1579 && ! TREE_OVERFLOW (t)
1580 && (TREE_INT_CST_HIGH (t) != hi
1581 || TREE_INT_CST_LOW (t) != low))
1582 TREE_OVERFLOW (t) = 1;
1584 TREE_CONSTANT_OVERFLOW (t) = (TREE_OVERFLOW (t)
1585 | TREE_CONSTANT_OVERFLOW (arg1)
1586 | TREE_CONSTANT_OVERFLOW (arg2));
1590 /* Define input and output argument for const_binop_1. */
1593 enum tree_code code; /* Input: tree code for operation*/
1594 tree type; /* Input: tree type for operation. */
1595 REAL_VALUE_TYPE d1, d2; /* Input: floating point operands. */
1596 tree t; /* Output: constant for result. */
1599 /* Do the real arithmetic for const_binop while protected by a
1600 float overflow handler. */
1603 const_binop_1 (data)
1606 struct cb_args *args = (struct cb_args *) data;
1607 REAL_VALUE_TYPE value;
1609 #ifdef REAL_ARITHMETIC
1610 REAL_ARITHMETIC (value, args->code, args->d1, args->d2);
1615 value = args->d1 + args->d2;
1619 value = args->d1 - args->d2;
1623 value = args->d1 * args->d2;
1627 #ifndef REAL_INFINITY
1632 value = args->d1 / args->d2;
1636 value = MIN (args->d1, args->d2);
1640 value = MAX (args->d1, args->d2);
1646 #endif /* no REAL_ARITHMETIC */
1649 = build_real (args->type,
1650 real_value_truncate (TYPE_MODE (args->type), value));
1653 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1654 constant. We assume ARG1 and ARG2 have the same data type, or at least
1655 are the same kind of constant and the same machine mode.
1657 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1660 const_binop (code, arg1, arg2, notrunc)
1661 enum tree_code code;
1662 register tree arg1, arg2;
1665 STRIP_NOPS (arg1); STRIP_NOPS (arg2);
1667 if (TREE_CODE (arg1) == INTEGER_CST)
1668 return int_const_binop (code, arg1, arg2, notrunc, 0);
1670 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1671 if (TREE_CODE (arg1) == REAL_CST)
1677 struct cb_args args;
1679 d1 = TREE_REAL_CST (arg1);
1680 d2 = TREE_REAL_CST (arg2);
1682 /* If either operand is a NaN, just return it. Otherwise, set up
1683 for floating-point trap; we return an overflow. */
1684 if (REAL_VALUE_ISNAN (d1))
1686 else if (REAL_VALUE_ISNAN (d2))
1689 /* Setup input for const_binop_1() */
1690 args.type = TREE_TYPE (arg1);
1695 if (do_float_handler (const_binop_1, (PTR) &args))
1696 /* Receive output from const_binop_1. */
1700 /* We got an exception from const_binop_1. */
1701 t = copy_node (arg1);
1706 = (force_fit_type (t, overflow)
1707 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
1708 TREE_CONSTANT_OVERFLOW (t)
1710 | TREE_CONSTANT_OVERFLOW (arg1)
1711 | TREE_CONSTANT_OVERFLOW (arg2);
1714 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
1715 if (TREE_CODE (arg1) == COMPLEX_CST)
1717 register tree type = TREE_TYPE (arg1);
1718 register tree r1 = TREE_REALPART (arg1);
1719 register tree i1 = TREE_IMAGPART (arg1);
1720 register tree r2 = TREE_REALPART (arg2);
1721 register tree i2 = TREE_IMAGPART (arg2);
1727 t = build_complex (type,
1728 const_binop (PLUS_EXPR, r1, r2, notrunc),
1729 const_binop (PLUS_EXPR, i1, i2, notrunc));
1733 t = build_complex (type,
1734 const_binop (MINUS_EXPR, r1, r2, notrunc),
1735 const_binop (MINUS_EXPR, i1, i2, notrunc));
1739 t = build_complex (type,
1740 const_binop (MINUS_EXPR,
1741 const_binop (MULT_EXPR,
1743 const_binop (MULT_EXPR,
1746 const_binop (PLUS_EXPR,
1747 const_binop (MULT_EXPR,
1749 const_binop (MULT_EXPR,
1756 register tree magsquared
1757 = const_binop (PLUS_EXPR,
1758 const_binop (MULT_EXPR, r2, r2, notrunc),
1759 const_binop (MULT_EXPR, i2, i2, notrunc),
1762 t = build_complex (type,
1764 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1765 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1766 const_binop (PLUS_EXPR,
1767 const_binop (MULT_EXPR, r1, r2,
1769 const_binop (MULT_EXPR, i1, i2,
1772 magsquared, notrunc),
1774 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1775 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1776 const_binop (MINUS_EXPR,
1777 const_binop (MULT_EXPR, i1, r2,
1779 const_binop (MULT_EXPR, r1, i2,
1782 magsquared, notrunc));
1794 /* Return an INTEGER_CST with value whose low-order HOST_BITS_PER_WIDE_INT
1795 bits are given by NUMBER and of the sizetype represented by KIND. */
1798 size_int_wide (number, kind)
1799 HOST_WIDE_INT number;
1800 enum size_type_kind kind;
1802 return size_int_type_wide (number, sizetype_tab[(int) kind]);
1805 /* Likewise, but the desired type is specified explicitly. */
1808 size_int_type_wide (number, type)
1809 HOST_WIDE_INT number;
1812 /* Type-size nodes already made for small sizes. */
1813 static tree size_table[2 * HOST_BITS_PER_WIDE_INT + 1];
1814 static int init_p = 0;
1817 if (ggc_p && ! init_p)
1819 ggc_add_tree_root ((tree *) size_table,
1820 sizeof size_table / sizeof (tree));
1824 /* If this is a positive number that fits in the table we use to hold
1825 cached entries, see if it is already in the table and put it there
1828 && number < (int) (sizeof size_table / sizeof size_table[0]) / 2)
1830 if (size_table[number] != 0)
1831 for (t = size_table[number]; t != 0; t = TREE_CHAIN (t))
1832 if (TREE_TYPE (t) == type)
1837 /* Make this a permanent node. */
1838 push_obstacks_nochange ();
1839 end_temporary_allocation ();
1842 t = build_int_2 (number, 0);
1843 TREE_TYPE (t) = type;
1844 TREE_CHAIN (t) = size_table[number];
1845 size_table[number] = t;
1853 t = build_int_2 (number, number < 0 ? -1 : 0);
1854 TREE_TYPE (t) = type;
1855 TREE_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (t) = force_fit_type (t, 0);
1859 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1860 is a tree code. The type of the result is taken from the operands.
1861 Both must be the same type integer type and it must be a size type.
1862 If the operands are constant, so is the result. */
1865 size_binop (code, arg0, arg1)
1866 enum tree_code code;
1869 tree type = TREE_TYPE (arg0);
1871 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1872 || type != TREE_TYPE (arg1))
1875 /* Handle the special case of two integer constants faster. */
1876 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1878 /* And some specific cases even faster than that. */
1879 if (code == PLUS_EXPR && integer_zerop (arg0))
1881 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1882 && integer_zerop (arg1))
1884 else if (code == MULT_EXPR && integer_onep (arg0))
1887 /* Handle general case of two integer constants. */
1888 return int_const_binop (code, arg0, arg1, 0, 1);
1891 if (arg0 == error_mark_node || arg1 == error_mark_node)
1892 return error_mark_node;
1894 return fold (build (code, type, arg0, arg1));
1897 /* Given two values, either both of sizetype or both of bitsizetype,
1898 compute the difference between the two values. Return the value
1899 in signed type corresponding to the type of the operands. */
1902 size_diffop (arg0, arg1)
1905 tree type = TREE_TYPE (arg0);
1908 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1909 || type != TREE_TYPE (arg1))
1912 /* If the type is already signed, just do the simple thing. */
1913 if (! TREE_UNSIGNED (type))
1914 return size_binop (MINUS_EXPR, arg0, arg1);
1916 ctype = (type == bitsizetype || type == ubitsizetype
1917 ? sbitsizetype : ssizetype);
1919 /* If either operand is not a constant, do the conversions to the signed
1920 type and subtract. The hardware will do the right thing with any
1921 overflow in the subtraction. */
1922 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
1923 return size_binop (MINUS_EXPR, convert (ctype, arg0),
1924 convert (ctype, arg1));
1926 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
1927 Otherwise, subtract the other way, convert to CTYPE (we know that can't
1928 overflow) and negate (which can't either). Special-case a result
1929 of zero while we're here. */
1930 if (tree_int_cst_equal (arg0, arg1))
1931 return convert (ctype, integer_zero_node);
1932 else if (tree_int_cst_lt (arg1, arg0))
1933 return convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
1935 return size_binop (MINUS_EXPR, convert (ctype, integer_zero_node),
1936 convert (ctype, size_binop (MINUS_EXPR, arg1, arg0)));
1939 /* This structure is used to communicate arguments to fold_convert_1. */
1942 tree arg1; /* Input: value to convert. */
1943 tree type; /* Input: type to convert value to. */
1944 tree t; /* Ouput: result of conversion. */
1947 /* Function to convert floating-point constants, protected by floating
1948 point exception handler. */
1951 fold_convert_1 (data)
1954 struct fc_args * args = (struct fc_args *) data;
1956 args->t = build_real (args->type,
1957 real_value_truncate (TYPE_MODE (args->type),
1958 TREE_REAL_CST (args->arg1)));
1961 /* Given T, a tree representing type conversion of ARG1, a constant,
1962 return a constant tree representing the result of conversion. */
1965 fold_convert (t, arg1)
1969 register tree type = TREE_TYPE (t);
1972 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
1974 if (TREE_CODE (arg1) == INTEGER_CST)
1976 /* If we would build a constant wider than GCC supports,
1977 leave the conversion unfolded. */
1978 if (TYPE_PRECISION (type) > 2 * HOST_BITS_PER_WIDE_INT)
1981 /* If we are trying to make a sizetype for a small integer, use
1982 size_int to pick up cached types to reduce duplicate nodes. */
1983 if (TREE_CODE (type) == INTEGER_CST && TYPE_IS_SIZETYPE (type)
1984 && TREE_INT_CST_HIGH (arg1) == 0
1985 && TREE_INT_CST_LOW (arg1) >= 0
1986 && TREE_INT_CST_LOW (arg1) < 1000)
1987 return size_int_type_wide (TREE_INT_CST_LOW (arg1), type);
1989 /* Given an integer constant, make new constant with new type,
1990 appropriately sign-extended or truncated. */
1991 t = build_int_2 (TREE_INT_CST_LOW (arg1),
1992 TREE_INT_CST_HIGH (arg1));
1993 TREE_TYPE (t) = type;
1994 /* Indicate an overflow if (1) ARG1 already overflowed,
1995 or (2) force_fit_type indicates an overflow.
1996 Tell force_fit_type that an overflow has already occurred
1997 if ARG1 is a too-large unsigned value and T is signed.
1998 But don't indicate an overflow if converting a pointer. */
2000 = ((force_fit_type (t,
2001 (TREE_INT_CST_HIGH (arg1) < 0
2002 && (TREE_UNSIGNED (type)
2003 < TREE_UNSIGNED (TREE_TYPE (arg1)))))
2004 && ! POINTER_TYPE_P (TREE_TYPE (arg1)))
2005 || TREE_OVERFLOW (arg1));
2006 TREE_CONSTANT_OVERFLOW (t)
2007 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
2009 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
2010 else if (TREE_CODE (arg1) == REAL_CST)
2012 /* Don't initialize these, use assignments.
2013 Initialized local aggregates don't work on old compilers. */
2017 tree type1 = TREE_TYPE (arg1);
2020 x = TREE_REAL_CST (arg1);
2021 l = real_value_from_int_cst (type1, TYPE_MIN_VALUE (type));
2023 no_upper_bound = (TYPE_MAX_VALUE (type) == NULL);
2024 if (!no_upper_bound)
2025 u = real_value_from_int_cst (type1, TYPE_MAX_VALUE (type));
2027 /* See if X will be in range after truncation towards 0.
2028 To compensate for truncation, move the bounds away from 0,
2029 but reject if X exactly equals the adjusted bounds. */
2030 #ifdef REAL_ARITHMETIC
2031 REAL_ARITHMETIC (l, MINUS_EXPR, l, dconst1);
2032 if (!no_upper_bound)
2033 REAL_ARITHMETIC (u, PLUS_EXPR, u, dconst1);
2036 if (!no_upper_bound)
2039 /* If X is a NaN, use zero instead and show we have an overflow.
2040 Otherwise, range check. */
2041 if (REAL_VALUE_ISNAN (x))
2042 overflow = 1, x = dconst0;
2043 else if (! (REAL_VALUES_LESS (l, x)
2045 && REAL_VALUES_LESS (x, u)))
2048 #ifndef REAL_ARITHMETIC
2050 HOST_WIDE_INT low, high;
2051 HOST_WIDE_INT half_word
2052 = (HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2);
2057 high = (HOST_WIDE_INT) (x / half_word / half_word);
2058 x -= (REAL_VALUE_TYPE) high * half_word * half_word;
2059 if (x >= (REAL_VALUE_TYPE) half_word * half_word / 2)
2061 low = x - (REAL_VALUE_TYPE) half_word * half_word / 2;
2062 low |= (HOST_WIDE_INT) -1 << (HOST_BITS_PER_WIDE_INT - 1);
2065 low = (HOST_WIDE_INT) x;
2066 if (TREE_REAL_CST (arg1) < 0)
2067 neg_double (low, high, &low, &high);
2068 t = build_int_2 (low, high);
2072 HOST_WIDE_INT low, high;
2073 REAL_VALUE_TO_INT (&low, &high, x);
2074 t = build_int_2 (low, high);
2077 TREE_TYPE (t) = type;
2079 = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
2080 TREE_CONSTANT_OVERFLOW (t)
2081 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
2083 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
2084 TREE_TYPE (t) = type;
2086 else if (TREE_CODE (type) == REAL_TYPE)
2088 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
2089 if (TREE_CODE (arg1) == INTEGER_CST)
2090 return build_real_from_int_cst (type, arg1);
2091 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
2092 if (TREE_CODE (arg1) == REAL_CST)
2094 struct fc_args args;
2096 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
2099 TREE_TYPE (arg1) = type;
2103 /* Setup input for fold_convert_1() */
2107 if (do_float_handler (fold_convert_1, (PTR) &args))
2109 /* Receive output from fold_convert_1() */
2114 /* We got an exception from fold_convert_1() */
2116 t = copy_node (arg1);
2120 = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
2121 TREE_CONSTANT_OVERFLOW (t)
2122 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
2126 TREE_CONSTANT (t) = 1;
2130 /* Return an expr equal to X but certainly not valid as an lvalue. */
2138 /* These things are certainly not lvalues. */
2139 if (TREE_CODE (x) == NON_LVALUE_EXPR
2140 || TREE_CODE (x) == INTEGER_CST
2141 || TREE_CODE (x) == REAL_CST
2142 || TREE_CODE (x) == STRING_CST
2143 || TREE_CODE (x) == ADDR_EXPR)
2146 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
2147 TREE_CONSTANT (result) = TREE_CONSTANT (x);
2151 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
2152 Zero means allow extended lvalues. */
2154 int pedantic_lvalues;
2156 /* When pedantic, return an expr equal to X but certainly not valid as a
2157 pedantic lvalue. Otherwise, return X. */
2160 pedantic_non_lvalue (x)
2163 if (pedantic_lvalues)
2164 return non_lvalue (x);
2169 /* Given a tree comparison code, return the code that is the logical inverse
2170 of the given code. It is not safe to do this for floating-point
2171 comparisons, except for NE_EXPR and EQ_EXPR. */
2173 static enum tree_code
2174 invert_tree_comparison (code)
2175 enum tree_code code;
2196 /* Similar, but return the comparison that results if the operands are
2197 swapped. This is safe for floating-point. */
2199 static enum tree_code
2200 swap_tree_comparison (code)
2201 enum tree_code code;
2221 /* Return nonzero if CODE is a tree code that represents a truth value. */
2224 truth_value_p (code)
2225 enum tree_code code;
2227 return (TREE_CODE_CLASS (code) == '<'
2228 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2229 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2230 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
2233 /* Return nonzero if two operands are necessarily equal.
2234 If ONLY_CONST is non-zero, only return non-zero for constants.
2235 This function tests whether the operands are indistinguishable;
2236 it does not test whether they are equal using C's == operation.
2237 The distinction is important for IEEE floating point, because
2238 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2239 (2) two NaNs may be indistinguishable, but NaN!=NaN. */
2242 operand_equal_p (arg0, arg1, only_const)
2246 /* If both types don't have the same signedness, then we can't consider
2247 them equal. We must check this before the STRIP_NOPS calls
2248 because they may change the signedness of the arguments. */
2249 if (TREE_UNSIGNED (TREE_TYPE (arg0)) != TREE_UNSIGNED (TREE_TYPE (arg1)))
2255 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2256 /* This is needed for conversions and for COMPONENT_REF.
2257 Might as well play it safe and always test this. */
2258 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
2259 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
2260 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
2263 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
2264 We don't care about side effects in that case because the SAVE_EXPR
2265 takes care of that for us. In all other cases, two expressions are
2266 equal if they have no side effects. If we have two identical
2267 expressions with side effects that should be treated the same due
2268 to the only side effects being identical SAVE_EXPR's, that will
2269 be detected in the recursive calls below. */
2270 if (arg0 == arg1 && ! only_const
2271 && (TREE_CODE (arg0) == SAVE_EXPR
2272 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
2275 /* Next handle constant cases, those for which we can return 1 even
2276 if ONLY_CONST is set. */
2277 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
2278 switch (TREE_CODE (arg0))
2281 return (! TREE_CONSTANT_OVERFLOW (arg0)
2282 && ! TREE_CONSTANT_OVERFLOW (arg1)
2283 && TREE_INT_CST_LOW (arg0) == TREE_INT_CST_LOW (arg1)
2284 && TREE_INT_CST_HIGH (arg0) == TREE_INT_CST_HIGH (arg1));
2287 return (! TREE_CONSTANT_OVERFLOW (arg0)
2288 && ! TREE_CONSTANT_OVERFLOW (arg1)
2289 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
2290 TREE_REAL_CST (arg1)));
2293 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
2295 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
2299 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
2300 && ! memcmp (TREE_STRING_POINTER (arg0),
2301 TREE_STRING_POINTER (arg1),
2302 TREE_STRING_LENGTH (arg0)));
2305 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
2314 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
2317 /* Two conversions are equal only if signedness and modes match. */
2318 if ((TREE_CODE (arg0) == NOP_EXPR || TREE_CODE (arg0) == CONVERT_EXPR)
2319 && (TREE_UNSIGNED (TREE_TYPE (arg0))
2320 != TREE_UNSIGNED (TREE_TYPE (arg1))))
2323 return operand_equal_p (TREE_OPERAND (arg0, 0),
2324 TREE_OPERAND (arg1, 0), 0);
2328 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0)
2329 && operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1),
2333 /* For commutative ops, allow the other order. */
2334 return ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MULT_EXPR
2335 || TREE_CODE (arg0) == MIN_EXPR || TREE_CODE (arg0) == MAX_EXPR
2336 || TREE_CODE (arg0) == BIT_IOR_EXPR
2337 || TREE_CODE (arg0) == BIT_XOR_EXPR
2338 || TREE_CODE (arg0) == BIT_AND_EXPR
2339 || TREE_CODE (arg0) == NE_EXPR || TREE_CODE (arg0) == EQ_EXPR)
2340 && operand_equal_p (TREE_OPERAND (arg0, 0),
2341 TREE_OPERAND (arg1, 1), 0)
2342 && operand_equal_p (TREE_OPERAND (arg0, 1),
2343 TREE_OPERAND (arg1, 0), 0));
2346 /* If either of the pointer (or reference) expressions we are dereferencing
2347 contain a side effect, these cannot be equal. */
2348 if (TREE_SIDE_EFFECTS (arg0)
2349 || TREE_SIDE_EFFECTS (arg1))
2352 switch (TREE_CODE (arg0))
2355 return operand_equal_p (TREE_OPERAND (arg0, 0),
2356 TREE_OPERAND (arg1, 0), 0);
2360 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2361 TREE_OPERAND (arg1, 0), 0)
2362 && operand_equal_p (TREE_OPERAND (arg0, 1),
2363 TREE_OPERAND (arg1, 1), 0));
2366 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2367 TREE_OPERAND (arg1, 0), 0)
2368 && operand_equal_p (TREE_OPERAND (arg0, 1),
2369 TREE_OPERAND (arg1, 1), 0)
2370 && operand_equal_p (TREE_OPERAND (arg0, 2),
2371 TREE_OPERAND (arg1, 2), 0));
2377 if (TREE_CODE (arg0) == RTL_EXPR)
2378 return rtx_equal_p (RTL_EXPR_RTL (arg0), RTL_EXPR_RTL (arg1));
2386 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2387 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2389 When in doubt, return 0. */
2392 operand_equal_for_comparison_p (arg0, arg1, other)
2396 int unsignedp1, unsignedpo;
2397 tree primarg0, primarg1, primother;
2398 unsigned correct_width;
2400 if (operand_equal_p (arg0, arg1, 0))
2403 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
2404 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
2407 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2408 and see if the inner values are the same. This removes any
2409 signedness comparison, which doesn't matter here. */
2410 primarg0 = arg0, primarg1 = arg1;
2411 STRIP_NOPS (primarg0); STRIP_NOPS (primarg1);
2412 if (operand_equal_p (primarg0, primarg1, 0))
2415 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2416 actual comparison operand, ARG0.
2418 First throw away any conversions to wider types
2419 already present in the operands. */
2421 primarg1 = get_narrower (arg1, &unsignedp1);
2422 primother = get_narrower (other, &unsignedpo);
2424 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
2425 if (unsignedp1 == unsignedpo
2426 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
2427 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
2429 tree type = TREE_TYPE (arg0);
2431 /* Make sure shorter operand is extended the right way
2432 to match the longer operand. */
2433 primarg1 = convert (signed_or_unsigned_type (unsignedp1,
2434 TREE_TYPE (primarg1)),
2437 if (operand_equal_p (arg0, convert (type, primarg1), 0))
2444 /* See if ARG is an expression that is either a comparison or is performing
2445 arithmetic on comparisons. The comparisons must only be comparing
2446 two different values, which will be stored in *CVAL1 and *CVAL2; if
2447 they are non-zero it means that some operands have already been found.
2448 No variables may be used anywhere else in the expression except in the
2449 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2450 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2452 If this is true, return 1. Otherwise, return zero. */
2455 twoval_comparison_p (arg, cval1, cval2, save_p)
2457 tree *cval1, *cval2;
2460 enum tree_code code = TREE_CODE (arg);
2461 char class = TREE_CODE_CLASS (code);
2463 /* We can handle some of the 'e' cases here. */
2464 if (class == 'e' && code == TRUTH_NOT_EXPR)
2466 else if (class == 'e'
2467 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
2468 || code == COMPOUND_EXPR))
2471 else if (class == 'e' && code == SAVE_EXPR && SAVE_EXPR_RTL (arg) == 0
2472 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
2474 /* If we've already found a CVAL1 or CVAL2, this expression is
2475 two complex to handle. */
2476 if (*cval1 || *cval2)
2486 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
2489 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
2490 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2491 cval1, cval2, save_p));
2497 if (code == COND_EXPR)
2498 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
2499 cval1, cval2, save_p)
2500 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2501 cval1, cval2, save_p)
2502 && twoval_comparison_p (TREE_OPERAND (arg, 2),
2503 cval1, cval2, save_p));
2507 /* First see if we can handle the first operand, then the second. For
2508 the second operand, we know *CVAL1 can't be zero. It must be that
2509 one side of the comparison is each of the values; test for the
2510 case where this isn't true by failing if the two operands
2513 if (operand_equal_p (TREE_OPERAND (arg, 0),
2514 TREE_OPERAND (arg, 1), 0))
2518 *cval1 = TREE_OPERAND (arg, 0);
2519 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
2521 else if (*cval2 == 0)
2522 *cval2 = TREE_OPERAND (arg, 0);
2523 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
2528 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
2530 else if (*cval2 == 0)
2531 *cval2 = TREE_OPERAND (arg, 1);
2532 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
2544 /* ARG is a tree that is known to contain just arithmetic operations and
2545 comparisons. Evaluate the operations in the tree substituting NEW0 for
2546 any occurrence of OLD0 as an operand of a comparison and likewise for
2550 eval_subst (arg, old0, new0, old1, new1)
2552 tree old0, new0, old1, new1;
2554 tree type = TREE_TYPE (arg);
2555 enum tree_code code = TREE_CODE (arg);
2556 char class = TREE_CODE_CLASS (code);
2558 /* We can handle some of the 'e' cases here. */
2559 if (class == 'e' && code == TRUTH_NOT_EXPR)
2561 else if (class == 'e'
2562 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2568 return fold (build1 (code, type,
2569 eval_subst (TREE_OPERAND (arg, 0),
2570 old0, new0, old1, new1)));
2573 return fold (build (code, type,
2574 eval_subst (TREE_OPERAND (arg, 0),
2575 old0, new0, old1, new1),
2576 eval_subst (TREE_OPERAND (arg, 1),
2577 old0, new0, old1, new1)));
2583 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
2586 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
2589 return fold (build (code, type,
2590 eval_subst (TREE_OPERAND (arg, 0),
2591 old0, new0, old1, new1),
2592 eval_subst (TREE_OPERAND (arg, 1),
2593 old0, new0, old1, new1),
2594 eval_subst (TREE_OPERAND (arg, 2),
2595 old0, new0, old1, new1)));
2599 /* fall through - ??? */
2603 tree arg0 = TREE_OPERAND (arg, 0);
2604 tree arg1 = TREE_OPERAND (arg, 1);
2606 /* We need to check both for exact equality and tree equality. The
2607 former will be true if the operand has a side-effect. In that
2608 case, we know the operand occurred exactly once. */
2610 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
2612 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
2615 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
2617 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
2620 return fold (build (code, type, arg0, arg1));
2628 /* Return a tree for the case when the result of an expression is RESULT
2629 converted to TYPE and OMITTED was previously an operand of the expression
2630 but is now not needed (e.g., we folded OMITTED * 0).
2632 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2633 the conversion of RESULT to TYPE. */
2636 omit_one_operand (type, result, omitted)
2637 tree type, result, omitted;
2639 tree t = convert (type, result);
2641 if (TREE_SIDE_EFFECTS (omitted))
2642 return build (COMPOUND_EXPR, type, omitted, t);
2644 return non_lvalue (t);
2647 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2650 pedantic_omit_one_operand (type, result, omitted)
2651 tree type, result, omitted;
2653 tree t = convert (type, result);
2655 if (TREE_SIDE_EFFECTS (omitted))
2656 return build (COMPOUND_EXPR, type, omitted, t);
2658 return pedantic_non_lvalue (t);
2663 /* Return a simplified tree node for the truth-negation of ARG. This
2664 never alters ARG itself. We assume that ARG is an operation that
2665 returns a truth value (0 or 1). */
2668 invert_truthvalue (arg)
2671 tree type = TREE_TYPE (arg);
2672 enum tree_code code = TREE_CODE (arg);
2674 if (code == ERROR_MARK)
2677 /* If this is a comparison, we can simply invert it, except for
2678 floating-point non-equality comparisons, in which case we just
2679 enclose a TRUTH_NOT_EXPR around what we have. */
2681 if (TREE_CODE_CLASS (code) == '<')
2683 if (FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg, 0)))
2684 && !flag_fast_math && code != NE_EXPR && code != EQ_EXPR)
2685 return build1 (TRUTH_NOT_EXPR, type, arg);
2687 return build (invert_tree_comparison (code), type,
2688 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
2694 return convert (type, build_int_2 (TREE_INT_CST_LOW (arg) == 0
2695 && TREE_INT_CST_HIGH (arg) == 0, 0));
2697 case TRUTH_AND_EXPR:
2698 return build (TRUTH_OR_EXPR, type,
2699 invert_truthvalue (TREE_OPERAND (arg, 0)),
2700 invert_truthvalue (TREE_OPERAND (arg, 1)));
2703 return build (TRUTH_AND_EXPR, type,
2704 invert_truthvalue (TREE_OPERAND (arg, 0)),
2705 invert_truthvalue (TREE_OPERAND (arg, 1)));
2707 case TRUTH_XOR_EXPR:
2708 /* Here we can invert either operand. We invert the first operand
2709 unless the second operand is a TRUTH_NOT_EXPR in which case our
2710 result is the XOR of the first operand with the inside of the
2711 negation of the second operand. */
2713 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
2714 return build (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
2715 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
2717 return build (TRUTH_XOR_EXPR, type,
2718 invert_truthvalue (TREE_OPERAND (arg, 0)),
2719 TREE_OPERAND (arg, 1));
2721 case TRUTH_ANDIF_EXPR:
2722 return build (TRUTH_ORIF_EXPR, type,
2723 invert_truthvalue (TREE_OPERAND (arg, 0)),
2724 invert_truthvalue (TREE_OPERAND (arg, 1)));
2726 case TRUTH_ORIF_EXPR:
2727 return build (TRUTH_ANDIF_EXPR, type,
2728 invert_truthvalue (TREE_OPERAND (arg, 0)),
2729 invert_truthvalue (TREE_OPERAND (arg, 1)));
2731 case TRUTH_NOT_EXPR:
2732 return TREE_OPERAND (arg, 0);
2735 return build (COND_EXPR, type, TREE_OPERAND (arg, 0),
2736 invert_truthvalue (TREE_OPERAND (arg, 1)),
2737 invert_truthvalue (TREE_OPERAND (arg, 2)));
2740 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
2741 invert_truthvalue (TREE_OPERAND (arg, 1)));
2743 case WITH_RECORD_EXPR:
2744 return build (WITH_RECORD_EXPR, type,
2745 invert_truthvalue (TREE_OPERAND (arg, 0)),
2746 TREE_OPERAND (arg, 1));
2748 case NON_LVALUE_EXPR:
2749 return invert_truthvalue (TREE_OPERAND (arg, 0));
2754 return build1 (TREE_CODE (arg), type,
2755 invert_truthvalue (TREE_OPERAND (arg, 0)));
2758 if (!integer_onep (TREE_OPERAND (arg, 1)))
2760 return build (EQ_EXPR, type, arg, convert (type, integer_zero_node));
2763 return build1 (TRUTH_NOT_EXPR, type, arg);
2765 case CLEANUP_POINT_EXPR:
2766 return build1 (CLEANUP_POINT_EXPR, type,
2767 invert_truthvalue (TREE_OPERAND (arg, 0)));
2772 if (TREE_CODE (TREE_TYPE (arg)) != BOOLEAN_TYPE)
2774 return build1 (TRUTH_NOT_EXPR, type, arg);
2777 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
2778 operands are another bit-wise operation with a common input. If so,
2779 distribute the bit operations to save an operation and possibly two if
2780 constants are involved. For example, convert
2781 (A | B) & (A | C) into A | (B & C)
2782 Further simplification will occur if B and C are constants.
2784 If this optimization cannot be done, 0 will be returned. */
2787 distribute_bit_expr (code, type, arg0, arg1)
2788 enum tree_code code;
2795 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2796 || TREE_CODE (arg0) == code
2797 || (TREE_CODE (arg0) != BIT_AND_EXPR
2798 && TREE_CODE (arg0) != BIT_IOR_EXPR))
2801 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
2803 common = TREE_OPERAND (arg0, 0);
2804 left = TREE_OPERAND (arg0, 1);
2805 right = TREE_OPERAND (arg1, 1);
2807 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
2809 common = TREE_OPERAND (arg0, 0);
2810 left = TREE_OPERAND (arg0, 1);
2811 right = TREE_OPERAND (arg1, 0);
2813 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
2815 common = TREE_OPERAND (arg0, 1);
2816 left = TREE_OPERAND (arg0, 0);
2817 right = TREE_OPERAND (arg1, 1);
2819 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
2821 common = TREE_OPERAND (arg0, 1);
2822 left = TREE_OPERAND (arg0, 0);
2823 right = TREE_OPERAND (arg1, 0);
2828 return fold (build (TREE_CODE (arg0), type, common,
2829 fold (build (code, type, left, right))));
2832 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
2833 starting at BITPOS. The field is unsigned if UNSIGNEDP is non-zero. */
2836 make_bit_field_ref (inner, type, bitsize, bitpos, unsignedp)
2839 int bitsize, bitpos;
2842 tree result = build (BIT_FIELD_REF, type, inner,
2843 size_int (bitsize), bitsize_int (bitpos));
2845 TREE_UNSIGNED (result) = unsignedp;
2850 /* Optimize a bit-field compare.
2852 There are two cases: First is a compare against a constant and the
2853 second is a comparison of two items where the fields are at the same
2854 bit position relative to the start of a chunk (byte, halfword, word)
2855 large enough to contain it. In these cases we can avoid the shift
2856 implicit in bitfield extractions.
2858 For constants, we emit a compare of the shifted constant with the
2859 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
2860 compared. For two fields at the same position, we do the ANDs with the
2861 similar mask and compare the result of the ANDs.
2863 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
2864 COMPARE_TYPE is the type of the comparison, and LHS and RHS
2865 are the left and right operands of the comparison, respectively.
2867 If the optimization described above can be done, we return the resulting
2868 tree. Otherwise we return zero. */
2871 optimize_bit_field_compare (code, compare_type, lhs, rhs)
2872 enum tree_code code;
2876 int lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
2877 tree type = TREE_TYPE (lhs);
2878 tree signed_type, unsigned_type;
2879 int const_p = TREE_CODE (rhs) == INTEGER_CST;
2880 enum machine_mode lmode, rmode, nmode;
2881 int lunsignedp, runsignedp;
2882 int lvolatilep = 0, rvolatilep = 0;
2884 tree linner, rinner = NULL_TREE;
2888 /* Get all the information about the extractions being done. If the bit size
2889 if the same as the size of the underlying object, we aren't doing an
2890 extraction at all and so can do nothing. We also don't want to
2891 do anything if the inner expression is a PLACEHOLDER_EXPR since we
2892 then will no longer be able to replace it. */
2893 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
2894 &lunsignedp, &lvolatilep, &alignment);
2895 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
2896 || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
2901 /* If this is not a constant, we can only do something if bit positions,
2902 sizes, and signedness are the same. */
2903 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
2904 &runsignedp, &rvolatilep, &alignment);
2906 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
2907 || lunsignedp != runsignedp || offset != 0
2908 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
2912 /* See if we can find a mode to refer to this field. We should be able to,
2913 but fail if we can't. */
2914 nmode = get_best_mode (lbitsize, lbitpos,
2915 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
2916 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
2917 TYPE_ALIGN (TREE_TYPE (rinner))),
2918 word_mode, lvolatilep || rvolatilep);
2919 if (nmode == VOIDmode)
2922 /* Set signed and unsigned types of the precision of this mode for the
2924 signed_type = type_for_mode (nmode, 0);
2925 unsigned_type = type_for_mode (nmode, 1);
2927 /* Compute the bit position and size for the new reference and our offset
2928 within it. If the new reference is the same size as the original, we
2929 won't optimize anything, so return zero. */
2930 nbitsize = GET_MODE_BITSIZE (nmode);
2931 nbitpos = lbitpos & ~ (nbitsize - 1);
2933 if (nbitsize == lbitsize)
2936 if (BYTES_BIG_ENDIAN)
2937 lbitpos = nbitsize - lbitsize - lbitpos;
2939 /* Make the mask to be used against the extracted field. */
2940 mask = build_int_2 (~0, ~0);
2941 TREE_TYPE (mask) = unsigned_type;
2942 force_fit_type (mask, 0);
2943 mask = convert (unsigned_type, mask);
2944 mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
2945 mask = const_binop (RSHIFT_EXPR, mask,
2946 size_int (nbitsize - lbitsize - lbitpos), 0);
2949 /* If not comparing with constant, just rework the comparison
2951 return build (code, compare_type,
2952 build (BIT_AND_EXPR, unsigned_type,
2953 make_bit_field_ref (linner, unsigned_type,
2954 nbitsize, nbitpos, 1),
2956 build (BIT_AND_EXPR, unsigned_type,
2957 make_bit_field_ref (rinner, unsigned_type,
2958 nbitsize, nbitpos, 1),
2961 /* Otherwise, we are handling the constant case. See if the constant is too
2962 big for the field. Warn and return a tree of for 0 (false) if so. We do
2963 this not only for its own sake, but to avoid having to test for this
2964 error case below. If we didn't, we might generate wrong code.
2966 For unsigned fields, the constant shifted right by the field length should
2967 be all zero. For signed fields, the high-order bits should agree with
2972 if (! integer_zerop (const_binop (RSHIFT_EXPR,
2973 convert (unsigned_type, rhs),
2974 size_int (lbitsize), 0)))
2976 warning ("comparison is always %d due to width of bitfield",
2978 return convert (compare_type,
2980 ? integer_one_node : integer_zero_node));
2985 tree tem = const_binop (RSHIFT_EXPR, convert (signed_type, rhs),
2986 size_int (lbitsize - 1), 0);
2987 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
2989 warning ("comparison is always %d due to width of bitfield",
2991 return convert (compare_type,
2993 ? integer_one_node : integer_zero_node));
2997 /* Single-bit compares should always be against zero. */
2998 if (lbitsize == 1 && ! integer_zerop (rhs))
3000 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
3001 rhs = convert (type, integer_zero_node);
3004 /* Make a new bitfield reference, shift the constant over the
3005 appropriate number of bits and mask it with the computed mask
3006 (in case this was a signed field). If we changed it, make a new one. */
3007 lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1);
3010 TREE_SIDE_EFFECTS (lhs) = 1;
3011 TREE_THIS_VOLATILE (lhs) = 1;
3014 rhs = fold (const_binop (BIT_AND_EXPR,
3015 const_binop (LSHIFT_EXPR,
3016 convert (unsigned_type, rhs),
3017 size_int (lbitpos), 0),
3020 return build (code, compare_type,
3021 build (BIT_AND_EXPR, unsigned_type, lhs, mask),
3025 /* Subroutine for fold_truthop: decode a field reference.
3027 If EXP is a comparison reference, we return the innermost reference.
3029 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
3030 set to the starting bit number.
3032 If the innermost field can be completely contained in a mode-sized
3033 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
3035 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
3036 otherwise it is not changed.
3038 *PUNSIGNEDP is set to the signedness of the field.
3040 *PMASK is set to the mask used. This is either contained in a
3041 BIT_AND_EXPR or derived from the width of the field.
3043 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
3045 Return 0 if this is not a component reference or is one that we can't
3046 do anything with. */
3049 decode_field_reference (exp, pbitsize, pbitpos, pmode, punsignedp,
3050 pvolatilep, pmask, pand_mask)
3052 int *pbitsize, *pbitpos;
3053 enum machine_mode *pmode;
3054 int *punsignedp, *pvolatilep;
3059 tree mask, inner, offset;
3064 /* All the optimizations using this function assume integer fields.
3065 There are problems with FP fields since the type_for_size call
3066 below can fail for, e.g., XFmode. */
3067 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
3072 if (TREE_CODE (exp) == BIT_AND_EXPR)
3074 and_mask = TREE_OPERAND (exp, 1);
3075 exp = TREE_OPERAND (exp, 0);
3076 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
3077 if (TREE_CODE (and_mask) != INTEGER_CST)
3082 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
3083 punsignedp, pvolatilep, &alignment);
3084 if ((inner == exp && and_mask == 0)
3085 || *pbitsize < 0 || offset != 0
3086 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
3089 /* Compute the mask to access the bitfield. */
3090 unsigned_type = type_for_size (*pbitsize, 1);
3091 precision = TYPE_PRECISION (unsigned_type);
3093 mask = build_int_2 (~0, ~0);
3094 TREE_TYPE (mask) = unsigned_type;
3095 force_fit_type (mask, 0);
3096 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3097 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3099 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
3101 mask = fold (build (BIT_AND_EXPR, unsigned_type,
3102 convert (unsigned_type, and_mask), mask));
3105 *pand_mask = and_mask;
3109 /* Return non-zero if MASK represents a mask of SIZE ones in the low-order
3113 all_ones_mask_p (mask, size)
3117 tree type = TREE_TYPE (mask);
3118 int precision = TYPE_PRECISION (type);
3121 tmask = build_int_2 (~0, ~0);
3122 TREE_TYPE (tmask) = signed_type (type);
3123 force_fit_type (tmask, 0);
3125 tree_int_cst_equal (mask,
3126 const_binop (RSHIFT_EXPR,
3127 const_binop (LSHIFT_EXPR, tmask,
3128 size_int (precision - size),
3130 size_int (precision - size), 0));
3133 /* Subroutine for fold_truthop: determine if an operand is simple enough
3134 to be evaluated unconditionally. */
3137 simple_operand_p (exp)
3140 /* Strip any conversions that don't change the machine mode. */
3141 while ((TREE_CODE (exp) == NOP_EXPR
3142 || TREE_CODE (exp) == CONVERT_EXPR)
3143 && (TYPE_MODE (TREE_TYPE (exp))
3144 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)))))
3145 exp = TREE_OPERAND (exp, 0);
3147 return (TREE_CODE_CLASS (TREE_CODE (exp)) == 'c'
3148 || (TREE_CODE_CLASS (TREE_CODE (exp)) == 'd'
3149 && ! TREE_ADDRESSABLE (exp)
3150 && ! TREE_THIS_VOLATILE (exp)
3151 && ! DECL_NONLOCAL (exp)
3152 /* Don't regard global variables as simple. They may be
3153 allocated in ways unknown to the compiler (shared memory,
3154 #pragma weak, etc). */
3155 && ! TREE_PUBLIC (exp)
3156 && ! DECL_EXTERNAL (exp)
3157 /* Loading a static variable is unduly expensive, but global
3158 registers aren't expensive. */
3159 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
3162 /* The following functions are subroutines to fold_range_test and allow it to
3163 try to change a logical combination of comparisons into a range test.
3166 X == 2 && X == 3 && X == 4 && X == 5
3170 (unsigned) (X - 2) <= 3
3172 We describe each set of comparisons as being either inside or outside
3173 a range, using a variable named like IN_P, and then describe the
3174 range with a lower and upper bound. If one of the bounds is omitted,
3175 it represents either the highest or lowest value of the type.
3177 In the comments below, we represent a range by two numbers in brackets
3178 preceded by a "+" to designate being inside that range, or a "-" to
3179 designate being outside that range, so the condition can be inverted by
3180 flipping the prefix. An omitted bound is represented by a "-". For
3181 example, "- [-, 10]" means being outside the range starting at the lowest
3182 possible value and ending at 10, in other words, being greater than 10.
3183 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
3186 We set up things so that the missing bounds are handled in a consistent
3187 manner so neither a missing bound nor "true" and "false" need to be
3188 handled using a special case. */
3190 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
3191 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
3192 and UPPER1_P are nonzero if the respective argument is an upper bound
3193 and zero for a lower. TYPE, if nonzero, is the type of the result; it
3194 must be specified for a comparison. ARG1 will be converted to ARG0's
3195 type if both are specified. */
3198 range_binop (code, type, arg0, upper0_p, arg1, upper1_p)
3199 enum tree_code code;
3202 int upper0_p, upper1_p;
3208 /* If neither arg represents infinity, do the normal operation.
3209 Else, if not a comparison, return infinity. Else handle the special
3210 comparison rules. Note that most of the cases below won't occur, but
3211 are handled for consistency. */
3213 if (arg0 != 0 && arg1 != 0)
3215 tem = fold (build (code, type != 0 ? type : TREE_TYPE (arg0),
3216 arg0, convert (TREE_TYPE (arg0), arg1)));
3218 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
3221 if (TREE_CODE_CLASS (code) != '<')
3224 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
3225 for neither. In real maths, we cannot assume open ended ranges are
3226 the same. But, this is computer arithmetic, where numbers are finite.
3227 We can therefore make the transformation of any unbounded range with
3228 the value Z, Z being greater than any representable number. This permits
3229 us to treat unbounded ranges as equal. */
3230 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
3231 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
3235 result = sgn0 == sgn1;
3238 result = sgn0 != sgn1;
3241 result = sgn0 < sgn1;
3244 result = sgn0 <= sgn1;
3247 result = sgn0 > sgn1;
3250 result = sgn0 >= sgn1;
3256 return convert (type, result ? integer_one_node : integer_zero_node);
3259 /* Given EXP, a logical expression, set the range it is testing into
3260 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
3261 actually being tested. *PLOW and *PHIGH will have be made the same type
3262 as the returned expression. If EXP is not a comparison, we will most
3263 likely not be returning a useful value and range. */
3266 make_range (exp, pin_p, plow, phigh)
3271 enum tree_code code;
3272 tree arg0 = NULL_TREE, arg1 = NULL_TREE, type = NULL_TREE;
3273 tree orig_type = NULL_TREE;
3275 tree low, high, n_low, n_high;
3277 /* Start with simply saying "EXP != 0" and then look at the code of EXP
3278 and see if we can refine the range. Some of the cases below may not
3279 happen, but it doesn't seem worth worrying about this. We "continue"
3280 the outer loop when we've changed something; otherwise we "break"
3281 the switch, which will "break" the while. */
3283 in_p = 0, low = high = convert (TREE_TYPE (exp), integer_zero_node);
3287 code = TREE_CODE (exp);
3289 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
3291 arg0 = TREE_OPERAND (exp, 0);
3292 if (TREE_CODE_CLASS (code) == '<'
3293 || TREE_CODE_CLASS (code) == '1'
3294 || TREE_CODE_CLASS (code) == '2')
3295 type = TREE_TYPE (arg0);
3296 if (TREE_CODE_CLASS (code) == '2'
3297 || TREE_CODE_CLASS (code) == '<'
3298 || (TREE_CODE_CLASS (code) == 'e'
3299 && tree_code_length[(int) code] > 1))
3300 arg1 = TREE_OPERAND (exp, 1);
3303 /* Set ORIG_TYPE as soon as TYPE is non-null so that we do not
3304 lose a cast by accident. */
3305 if (type != NULL_TREE && orig_type == NULL_TREE)
3310 case TRUTH_NOT_EXPR:
3311 in_p = ! in_p, exp = arg0;
3314 case EQ_EXPR: case NE_EXPR:
3315 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
3316 /* We can only do something if the range is testing for zero
3317 and if the second operand is an integer constant. Note that
3318 saying something is "in" the range we make is done by
3319 complementing IN_P since it will set in the initial case of
3320 being not equal to zero; "out" is leaving it alone. */
3321 if (low == 0 || high == 0
3322 || ! integer_zerop (low) || ! integer_zerop (high)
3323 || TREE_CODE (arg1) != INTEGER_CST)
3328 case NE_EXPR: /* - [c, c] */
3331 case EQ_EXPR: /* + [c, c] */
3332 in_p = ! in_p, low = high = arg1;
3334 case GT_EXPR: /* - [-, c] */
3335 low = 0, high = arg1;
3337 case GE_EXPR: /* + [c, -] */
3338 in_p = ! in_p, low = arg1, high = 0;
3340 case LT_EXPR: /* - [c, -] */
3341 low = arg1, high = 0;
3343 case LE_EXPR: /* + [-, c] */
3344 in_p = ! in_p, low = 0, high = arg1;
3352 /* If this is an unsigned comparison, we also know that EXP is
3353 greater than or equal to zero. We base the range tests we make
3354 on that fact, so we record it here so we can parse existing
3356 if (TREE_UNSIGNED (type) && (low == 0 || high == 0))
3358 if (! merge_ranges (&n_in_p, &n_low, &n_high, in_p, low, high,
3359 1, convert (type, integer_zero_node),
3363 in_p = n_in_p, low = n_low, high = n_high;
3365 /* If the high bound is missing, but we
3366 have a low bound, reverse the range so
3367 it goes from zero to the low bound minus 1. */
3368 if (high == 0 && low)
3371 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
3372 integer_one_node, 0);
3373 low = convert (type, integer_zero_node);
3379 /* (-x) IN [a,b] -> x in [-b, -a] */
3380 n_low = range_binop (MINUS_EXPR, type,
3381 convert (type, integer_zero_node), 0, high, 1);
3382 n_high = range_binop (MINUS_EXPR, type,
3383 convert (type, integer_zero_node), 0, low, 0);
3384 low = n_low, high = n_high;
3390 exp = build (MINUS_EXPR, type, negate_expr (arg0),
3391 convert (type, integer_one_node));
3394 case PLUS_EXPR: case MINUS_EXPR:
3395 if (TREE_CODE (arg1) != INTEGER_CST)
3398 /* If EXP is signed, any overflow in the computation is undefined,
3399 so we don't worry about it so long as our computations on
3400 the bounds don't overflow. For unsigned, overflow is defined
3401 and this is exactly the right thing. */
3402 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3403 type, low, 0, arg1, 0);
3404 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3405 type, high, 1, arg1, 0);
3406 if ((n_low != 0 && TREE_OVERFLOW (n_low))
3407 || (n_high != 0 && TREE_OVERFLOW (n_high)))
3410 /* Check for an unsigned range which has wrapped around the maximum
3411 value thus making n_high < n_low, and normalize it. */
3412 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
3414 low = range_binop (PLUS_EXPR, type, n_high, 0,
3415 integer_one_node, 0);
3416 high = range_binop (MINUS_EXPR, type, n_low, 0,
3417 integer_one_node, 0);
3421 low = n_low, high = n_high;
3426 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
3427 if (TYPE_PRECISION (type) > TYPE_PRECISION (orig_type))
3430 if (! INTEGRAL_TYPE_P (type)
3431 || (low != 0 && ! int_fits_type_p (low, type))
3432 || (high != 0 && ! int_fits_type_p (high, type)))
3435 n_low = low, n_high = high;
3438 n_low = convert (type, n_low);
3441 n_high = convert (type, n_high);
3443 /* If we're converting from an unsigned to a signed type,
3444 we will be doing the comparison as unsigned. The tests above
3445 have already verified that LOW and HIGH are both positive.
3447 So we have to make sure that the original unsigned value will
3448 be interpreted as positive. */
3449 if (TREE_UNSIGNED (type) && ! TREE_UNSIGNED (TREE_TYPE (exp)))
3451 tree equiv_type = type_for_mode (TYPE_MODE (type), 1);
3454 /* A range without an upper bound is, naturally, unbounded.
3455 Since convert would have cropped a very large value, use
3456 the max value for the destination type. */
3458 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
3459 : TYPE_MAX_VALUE (type);
3461 high_positive = fold (build (RSHIFT_EXPR, type,
3462 convert (type, high_positive),
3463 convert (type, integer_one_node)));
3465 /* If the low bound is specified, "and" the range with the
3466 range for which the original unsigned value will be
3470 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3472 1, convert (type, integer_zero_node),
3476 in_p = (n_in_p == in_p);
3480 /* Otherwise, "or" the range with the range of the input
3481 that will be interpreted as negative. */
3482 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3484 1, convert (type, integer_zero_node),
3488 in_p = (in_p != n_in_p);
3493 low = n_low, high = n_high;
3503 /* If EXP is a constant, we can evaluate whether this is true or false. */
3504 if (TREE_CODE (exp) == INTEGER_CST)
3506 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
3508 && integer_onep (range_binop (LE_EXPR, integer_type_node,
3514 *pin_p = in_p, *plow = low, *phigh = high;
3518 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3519 type, TYPE, return an expression to test if EXP is in (or out of, depending
3520 on IN_P) the range. */
3523 build_range_check (type, exp, in_p, low, high)
3529 tree etype = TREE_TYPE (exp);
3533 && (0 != (value = build_range_check (type, exp, 1, low, high))))
3534 return invert_truthvalue (value);
3536 else if (low == 0 && high == 0)
3537 return convert (type, integer_one_node);
3540 return fold (build (LE_EXPR, type, exp, high));
3543 return fold (build (GE_EXPR, type, exp, low));
3545 else if (operand_equal_p (low, high, 0))
3546 return fold (build (EQ_EXPR, type, exp, low));
3548 else if (TREE_UNSIGNED (etype) && integer_zerop (low))
3549 return build_range_check (type, exp, 1, 0, high);
3551 else if (integer_zerop (low))
3553 utype = unsigned_type (etype);
3554 return build_range_check (type, convert (utype, exp), 1, 0,
3555 convert (utype, high));
3558 else if (0 != (value = const_binop (MINUS_EXPR, high, low, 0))
3559 && ! TREE_OVERFLOW (value))
3560 return build_range_check (type,
3561 fold (build (MINUS_EXPR, etype, exp, low)),
3562 1, convert (etype, integer_zero_node), value);
3567 /* Given two ranges, see if we can merge them into one. Return 1 if we
3568 can, 0 if we can't. Set the output range into the specified parameters. */
3571 merge_ranges (pin_p, plow, phigh, in0_p, low0, high0, in1_p, low1, high1)
3575 tree low0, high0, low1, high1;
3583 int lowequal = ((low0 == 0 && low1 == 0)
3584 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3585 low0, 0, low1, 0)));
3586 int highequal = ((high0 == 0 && high1 == 0)
3587 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3588 high0, 1, high1, 1)));
3590 /* Make range 0 be the range that starts first, or ends last if they
3591 start at the same value. Swap them if it isn't. */
3592 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
3595 && integer_onep (range_binop (GT_EXPR, integer_type_node,
3596 high1, 1, high0, 1))))
3598 temp = in0_p, in0_p = in1_p, in1_p = temp;
3599 tem = low0, low0 = low1, low1 = tem;
3600 tem = high0, high0 = high1, high1 = tem;
3603 /* Now flag two cases, whether the ranges are disjoint or whether the
3604 second range is totally subsumed in the first. Note that the tests
3605 below are simplified by the ones above. */
3606 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
3607 high0, 1, low1, 0));
3608 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
3609 high1, 1, high0, 1));
3611 /* We now have four cases, depending on whether we are including or
3612 excluding the two ranges. */
3615 /* If they don't overlap, the result is false. If the second range
3616 is a subset it is the result. Otherwise, the range is from the start
3617 of the second to the end of the first. */
3619 in_p = 0, low = high = 0;
3621 in_p = 1, low = low1, high = high1;
3623 in_p = 1, low = low1, high = high0;
3626 else if (in0_p && ! in1_p)
3628 /* If they don't overlap, the result is the first range. If they are
3629 equal, the result is false. If the second range is a subset of the
3630 first, and the ranges begin at the same place, we go from just after
3631 the end of the first range to the end of the second. If the second
3632 range is not a subset of the first, or if it is a subset and both
3633 ranges end at the same place, the range starts at the start of the
3634 first range and ends just before the second range.
3635 Otherwise, we can't describe this as a single range. */
3637 in_p = 1, low = low0, high = high0;
3638 else if (lowequal && highequal)
3639 in_p = 0, low = high = 0;
3640 else if (subset && lowequal)
3642 in_p = 1, high = high0;
3643 low = range_binop (PLUS_EXPR, NULL_TREE, high1, 0,
3644 integer_one_node, 0);
3646 else if (! subset || highequal)
3648 in_p = 1, low = low0;
3649 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
3650 integer_one_node, 0);
3656 else if (! in0_p && in1_p)
3658 /* If they don't overlap, the result is the second range. If the second
3659 is a subset of the first, the result is false. Otherwise,
3660 the range starts just after the first range and ends at the
3661 end of the second. */
3663 in_p = 1, low = low1, high = high1;
3664 else if (subset || highequal)
3665 in_p = 0, low = high = 0;
3668 in_p = 1, high = high1;
3669 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
3670 integer_one_node, 0);
3676 /* The case where we are excluding both ranges. Here the complex case
3677 is if they don't overlap. In that case, the only time we have a
3678 range is if they are adjacent. If the second is a subset of the
3679 first, the result is the first. Otherwise, the range to exclude
3680 starts at the beginning of the first range and ends at the end of the
3684 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
3685 range_binop (PLUS_EXPR, NULL_TREE,
3687 integer_one_node, 1),
3689 in_p = 0, low = low0, high = high1;
3694 in_p = 0, low = low0, high = high0;
3696 in_p = 0, low = low0, high = high1;
3699 *pin_p = in_p, *plow = low, *phigh = high;
3703 /* EXP is some logical combination of boolean tests. See if we can
3704 merge it into some range test. Return the new tree if so. */
3707 fold_range_test (exp)
3710 int or_op = (TREE_CODE (exp) == TRUTH_ORIF_EXPR
3711 || TREE_CODE (exp) == TRUTH_OR_EXPR);
3712 int in0_p, in1_p, in_p;
3713 tree low0, low1, low, high0, high1, high;
3714 tree lhs = make_range (TREE_OPERAND (exp, 0), &in0_p, &low0, &high0);
3715 tree rhs = make_range (TREE_OPERAND (exp, 1), &in1_p, &low1, &high1);
3718 /* If this is an OR operation, invert both sides; we will invert
3719 again at the end. */
3721 in0_p = ! in0_p, in1_p = ! in1_p;
3723 /* If both expressions are the same, if we can merge the ranges, and we
3724 can build the range test, return it or it inverted. If one of the
3725 ranges is always true or always false, consider it to be the same
3726 expression as the other. */
3727 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
3728 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
3730 && 0 != (tem = (build_range_check (TREE_TYPE (exp),
3732 : rhs != 0 ? rhs : integer_zero_node,
3734 return or_op ? invert_truthvalue (tem) : tem;
3736 /* On machines where the branch cost is expensive, if this is a
3737 short-circuited branch and the underlying object on both sides
3738 is the same, make a non-short-circuit operation. */
3739 else if (BRANCH_COST >= 2
3740 && (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3741 || TREE_CODE (exp) == TRUTH_ORIF_EXPR)
3742 && operand_equal_p (lhs, rhs, 0))
3744 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
3745 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
3746 which cases we can't do this. */
3747 if (simple_operand_p (lhs))
3748 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3749 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3750 TREE_TYPE (exp), TREE_OPERAND (exp, 0),
3751 TREE_OPERAND (exp, 1));
3753 else if (global_bindings_p () == 0
3754 && ! contains_placeholder_p (lhs))
3756 tree common = save_expr (lhs);
3758 if (0 != (lhs = build_range_check (TREE_TYPE (exp), common,
3759 or_op ? ! in0_p : in0_p,
3761 && (0 != (rhs = build_range_check (TREE_TYPE (exp), common,
3762 or_op ? ! in1_p : in1_p,
3764 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3765 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3766 TREE_TYPE (exp), lhs, rhs);
3773 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
3774 bit value. Arrange things so the extra bits will be set to zero if and
3775 only if C is signed-extended to its full width. If MASK is nonzero,
3776 it is an INTEGER_CST that should be AND'ed with the extra bits. */
3779 unextend (c, p, unsignedp, mask)
3785 tree type = TREE_TYPE (c);
3786 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
3789 if (p == modesize || unsignedp)
3792 /* We work by getting just the sign bit into the low-order bit, then
3793 into the high-order bit, then sign-extend. We then XOR that value
3795 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
3796 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
3798 /* We must use a signed type in order to get an arithmetic right shift.
3799 However, we must also avoid introducing accidental overflows, so that
3800 a subsequent call to integer_zerop will work. Hence we must
3801 do the type conversion here. At this point, the constant is either
3802 zero or one, and the conversion to a signed type can never overflow.
3803 We could get an overflow if this conversion is done anywhere else. */
3804 if (TREE_UNSIGNED (type))
3805 temp = convert (signed_type (type), temp);
3807 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
3808 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
3810 temp = const_binop (BIT_AND_EXPR, temp, convert (TREE_TYPE (c), mask), 0);
3811 /* If necessary, convert the type back to match the type of C. */
3812 if (TREE_UNSIGNED (type))
3813 temp = convert (type, temp);
3815 return convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
3818 /* Find ways of folding logical expressions of LHS and RHS:
3819 Try to merge two comparisons to the same innermost item.
3820 Look for range tests like "ch >= '0' && ch <= '9'".
3821 Look for combinations of simple terms on machines with expensive branches
3822 and evaluate the RHS unconditionally.
3824 For example, if we have p->a == 2 && p->b == 4 and we can make an
3825 object large enough to span both A and B, we can do this with a comparison
3826 against the object ANDed with the a mask.
3828 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
3829 operations to do this with one comparison.
3831 We check for both normal comparisons and the BIT_AND_EXPRs made this by
3832 function and the one above.
3834 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
3835 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
3837 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
3840 We return the simplified tree or 0 if no optimization is possible. */
3843 fold_truthop (code, truth_type, lhs, rhs)
3844 enum tree_code code;
3845 tree truth_type, lhs, rhs;
3847 /* If this is the "or" of two comparisons, we can do something if we
3848 the comparisons are NE_EXPR. If this is the "and", we can do something
3849 if the comparisons are EQ_EXPR. I.e.,
3850 (a->b == 2 && a->c == 4) can become (a->new == NEW).
3852 WANTED_CODE is this operation code. For single bit fields, we can
3853 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
3854 comparison for one-bit fields. */
3856 enum tree_code wanted_code;
3857 enum tree_code lcode, rcode;
3858 tree ll_arg, lr_arg, rl_arg, rr_arg;
3859 tree ll_inner, lr_inner, rl_inner, rr_inner;
3860 int ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
3861 int rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
3862 int xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
3863 int lnbitsize, lnbitpos, rnbitsize, rnbitpos;
3864 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
3865 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
3866 enum machine_mode lnmode, rnmode;
3867 tree ll_mask, lr_mask, rl_mask, rr_mask;
3868 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
3869 tree l_const, r_const;
3870 tree lntype, rntype, result;
3871 int first_bit, end_bit;
3874 /* Start by getting the comparison codes. Fail if anything is volatile.
3875 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
3876 it were surrounded with a NE_EXPR. */
3878 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
3881 lcode = TREE_CODE (lhs);
3882 rcode = TREE_CODE (rhs);
3884 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
3885 lcode = NE_EXPR, lhs = build (NE_EXPR, truth_type, lhs, integer_zero_node);
3887 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
3888 rcode = NE_EXPR, rhs = build (NE_EXPR, truth_type, rhs, integer_zero_node);
3890 if (TREE_CODE_CLASS (lcode) != '<' || TREE_CODE_CLASS (rcode) != '<')
3893 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
3894 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
3896 ll_arg = TREE_OPERAND (lhs, 0);
3897 lr_arg = TREE_OPERAND (lhs, 1);
3898 rl_arg = TREE_OPERAND (rhs, 0);
3899 rr_arg = TREE_OPERAND (rhs, 1);
3901 /* If the RHS can be evaluated unconditionally and its operands are
3902 simple, it wins to evaluate the RHS unconditionally on machines
3903 with expensive branches. In this case, this isn't a comparison
3904 that can be merged. Avoid doing this if the RHS is a floating-point
3905 comparison since those can trap. */
3907 if (BRANCH_COST >= 2
3908 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
3909 && simple_operand_p (rl_arg)
3910 && simple_operand_p (rr_arg))
3911 return build (code, truth_type, lhs, rhs);
3913 /* See if the comparisons can be merged. Then get all the parameters for
3916 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
3917 || (rcode != EQ_EXPR && rcode != NE_EXPR))
3921 ll_inner = decode_field_reference (ll_arg,
3922 &ll_bitsize, &ll_bitpos, &ll_mode,
3923 &ll_unsignedp, &volatilep, &ll_mask,
3925 lr_inner = decode_field_reference (lr_arg,
3926 &lr_bitsize, &lr_bitpos, &lr_mode,
3927 &lr_unsignedp, &volatilep, &lr_mask,
3929 rl_inner = decode_field_reference (rl_arg,
3930 &rl_bitsize, &rl_bitpos, &rl_mode,
3931 &rl_unsignedp, &volatilep, &rl_mask,
3933 rr_inner = decode_field_reference (rr_arg,
3934 &rr_bitsize, &rr_bitpos, &rr_mode,
3935 &rr_unsignedp, &volatilep, &rr_mask,
3938 /* It must be true that the inner operation on the lhs of each
3939 comparison must be the same if we are to be able to do anything.
3940 Then see if we have constants. If not, the same must be true for
3942 if (volatilep || ll_inner == 0 || rl_inner == 0
3943 || ! operand_equal_p (ll_inner, rl_inner, 0))
3946 if (TREE_CODE (lr_arg) == INTEGER_CST
3947 && TREE_CODE (rr_arg) == INTEGER_CST)
3948 l_const = lr_arg, r_const = rr_arg;
3949 else if (lr_inner == 0 || rr_inner == 0
3950 || ! operand_equal_p (lr_inner, rr_inner, 0))
3953 l_const = r_const = 0;
3955 /* If either comparison code is not correct for our logical operation,
3956 fail. However, we can convert a one-bit comparison against zero into
3957 the opposite comparison against that bit being set in the field. */
3959 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
3960 if (lcode != wanted_code)
3962 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
3964 /* Make the left operand unsigned, since we are only interested
3965 in the value of one bit. Otherwise we are doing the wrong
3974 /* This is analogous to the code for l_const above. */
3975 if (rcode != wanted_code)
3977 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
3986 /* See if we can find a mode that contains both fields being compared on
3987 the left. If we can't, fail. Otherwise, update all constants and masks
3988 to be relative to a field of that size. */
3989 first_bit = MIN (ll_bitpos, rl_bitpos);
3990 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
3991 lnmode = get_best_mode (end_bit - first_bit, first_bit,
3992 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
3994 if (lnmode == VOIDmode)
3997 lnbitsize = GET_MODE_BITSIZE (lnmode);
3998 lnbitpos = first_bit & ~ (lnbitsize - 1);
3999 lntype = type_for_size (lnbitsize, 1);
4000 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
4002 if (BYTES_BIG_ENDIAN)
4004 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
4005 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
4008 ll_mask = const_binop (LSHIFT_EXPR, convert (lntype, ll_mask),
4009 size_int (xll_bitpos), 0);
4010 rl_mask = const_binop (LSHIFT_EXPR, convert (lntype, rl_mask),
4011 size_int (xrl_bitpos), 0);
4015 l_const = convert (lntype, l_const);
4016 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
4017 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
4018 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
4019 fold (build1 (BIT_NOT_EXPR,
4023 warning ("comparison is always %d", wanted_code == NE_EXPR);
4025 return convert (truth_type,
4026 wanted_code == NE_EXPR
4027 ? integer_one_node : integer_zero_node);
4032 r_const = convert (lntype, r_const);
4033 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
4034 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
4035 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
4036 fold (build1 (BIT_NOT_EXPR,
4040 warning ("comparison is always %d", wanted_code == NE_EXPR);
4042 return convert (truth_type,
4043 wanted_code == NE_EXPR
4044 ? integer_one_node : integer_zero_node);
4048 /* If the right sides are not constant, do the same for it. Also,
4049 disallow this optimization if a size or signedness mismatch occurs
4050 between the left and right sides. */
4053 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
4054 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
4055 /* Make sure the two fields on the right
4056 correspond to the left without being swapped. */
4057 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
4060 first_bit = MIN (lr_bitpos, rr_bitpos);
4061 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
4062 rnmode = get_best_mode (end_bit - first_bit, first_bit,
4063 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
4065 if (rnmode == VOIDmode)
4068 rnbitsize = GET_MODE_BITSIZE (rnmode);
4069 rnbitpos = first_bit & ~ (rnbitsize - 1);
4070 rntype = type_for_size (rnbitsize, 1);
4071 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
4073 if (BYTES_BIG_ENDIAN)
4075 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
4076 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
4079 lr_mask = const_binop (LSHIFT_EXPR, convert (rntype, lr_mask),
4080 size_int (xlr_bitpos), 0);
4081 rr_mask = const_binop (LSHIFT_EXPR, convert (rntype, rr_mask),
4082 size_int (xrr_bitpos), 0);
4084 /* Make a mask that corresponds to both fields being compared.
4085 Do this for both items being compared. If the operands are the
4086 same size and the bits being compared are in the same position
4087 then we can do this by masking both and comparing the masked
4089 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4090 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
4091 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
4093 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4094 ll_unsignedp || rl_unsignedp);
4095 if (! all_ones_mask_p (ll_mask, lnbitsize))
4096 lhs = build (BIT_AND_EXPR, lntype, lhs, ll_mask);
4098 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
4099 lr_unsignedp || rr_unsignedp);
4100 if (! all_ones_mask_p (lr_mask, rnbitsize))
4101 rhs = build (BIT_AND_EXPR, rntype, rhs, lr_mask);
4103 return build (wanted_code, truth_type, lhs, rhs);
4106 /* There is still another way we can do something: If both pairs of
4107 fields being compared are adjacent, we may be able to make a wider
4108 field containing them both.
4110 Note that we still must mask the lhs/rhs expressions. Furthermore,
4111 the mask must be shifted to account for the shift done by
4112 make_bit_field_ref. */
4113 if ((ll_bitsize + ll_bitpos == rl_bitpos
4114 && lr_bitsize + lr_bitpos == rr_bitpos)
4115 || (ll_bitpos == rl_bitpos + rl_bitsize
4116 && lr_bitpos == rr_bitpos + rr_bitsize))
4120 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
4121 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
4122 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
4123 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
4125 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
4126 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
4127 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
4128 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
4130 /* Convert to the smaller type before masking out unwanted bits. */
4132 if (lntype != rntype)
4134 if (lnbitsize > rnbitsize)
4136 lhs = convert (rntype, lhs);
4137 ll_mask = convert (rntype, ll_mask);
4140 else if (lnbitsize < rnbitsize)
4142 rhs = convert (lntype, rhs);
4143 lr_mask = convert (lntype, lr_mask);
4148 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
4149 lhs = build (BIT_AND_EXPR, type, lhs, ll_mask);
4151 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
4152 rhs = build (BIT_AND_EXPR, type, rhs, lr_mask);
4154 return build (wanted_code, truth_type, lhs, rhs);
4160 /* Handle the case of comparisons with constants. If there is something in
4161 common between the masks, those bits of the constants must be the same.
4162 If not, the condition is always false. Test for this to avoid generating
4163 incorrect code below. */
4164 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
4165 if (! integer_zerop (result)
4166 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
4167 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
4169 if (wanted_code == NE_EXPR)
4171 warning ("`or' of unmatched not-equal tests is always 1");
4172 return convert (truth_type, integer_one_node);
4176 warning ("`and' of mutually exclusive equal-tests is always 0");
4177 return convert (truth_type, integer_zero_node);
4181 /* Construct the expression we will return. First get the component
4182 reference we will make. Unless the mask is all ones the width of
4183 that field, perform the mask operation. Then compare with the
4185 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4186 ll_unsignedp || rl_unsignedp);
4188 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4189 if (! all_ones_mask_p (ll_mask, lnbitsize))
4190 result = build (BIT_AND_EXPR, lntype, result, ll_mask);
4192 return build (wanted_code, truth_type, result,
4193 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
4196 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
4200 optimize_minmax_comparison (t)
4203 tree type = TREE_TYPE (t);
4204 tree arg0 = TREE_OPERAND (t, 0);
4205 enum tree_code op_code;
4206 tree comp_const = TREE_OPERAND (t, 1);
4208 int consts_equal, consts_lt;
4211 STRIP_SIGN_NOPS (arg0);
4213 op_code = TREE_CODE (arg0);
4214 minmax_const = TREE_OPERAND (arg0, 1);
4215 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
4216 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
4217 inner = TREE_OPERAND (arg0, 0);
4219 /* If something does not permit us to optimize, return the original tree. */
4220 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
4221 || TREE_CODE (comp_const) != INTEGER_CST
4222 || TREE_CONSTANT_OVERFLOW (comp_const)
4223 || TREE_CODE (minmax_const) != INTEGER_CST
4224 || TREE_CONSTANT_OVERFLOW (minmax_const))
4227 /* Now handle all the various comparison codes. We only handle EQ_EXPR
4228 and GT_EXPR, doing the rest with recursive calls using logical
4230 switch (TREE_CODE (t))
4232 case NE_EXPR: case LT_EXPR: case LE_EXPR:
4234 invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t)));
4238 fold (build (TRUTH_ORIF_EXPR, type,
4239 optimize_minmax_comparison
4240 (build (EQ_EXPR, type, arg0, comp_const)),
4241 optimize_minmax_comparison
4242 (build (GT_EXPR, type, arg0, comp_const))));
4245 if (op_code == MAX_EXPR && consts_equal)
4246 /* MAX (X, 0) == 0 -> X <= 0 */
4247 return fold (build (LE_EXPR, type, inner, comp_const));
4249 else if (op_code == MAX_EXPR && consts_lt)
4250 /* MAX (X, 0) == 5 -> X == 5 */
4251 return fold (build (EQ_EXPR, type, inner, comp_const));
4253 else if (op_code == MAX_EXPR)
4254 /* MAX (X, 0) == -1 -> false */
4255 return omit_one_operand (type, integer_zero_node, inner);
4257 else if (consts_equal)
4258 /* MIN (X, 0) == 0 -> X >= 0 */
4259 return fold (build (GE_EXPR, type, inner, comp_const));
4262 /* MIN (X, 0) == 5 -> false */
4263 return omit_one_operand (type, integer_zero_node, inner);
4266 /* MIN (X, 0) == -1 -> X == -1 */
4267 return fold (build (EQ_EXPR, type, inner, comp_const));
4270 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
4271 /* MAX (X, 0) > 0 -> X > 0
4272 MAX (X, 0) > 5 -> X > 5 */
4273 return fold (build (GT_EXPR, type, inner, comp_const));
4275 else if (op_code == MAX_EXPR)
4276 /* MAX (X, 0) > -1 -> true */
4277 return omit_one_operand (type, integer_one_node, inner);
4279 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
4280 /* MIN (X, 0) > 0 -> false
4281 MIN (X, 0) > 5 -> false */
4282 return omit_one_operand (type, integer_zero_node, inner);
4285 /* MIN (X, 0) > -1 -> X > -1 */
4286 return fold (build (GT_EXPR, type, inner, comp_const));
4293 /* T is an integer expression that is being multiplied, divided, or taken a
4294 modulus (CODE says which and what kind of divide or modulus) by a
4295 constant C. See if we can eliminate that operation by folding it with
4296 other operations already in T. WIDE_TYPE, if non-null, is a type that
4297 should be used for the computation if wider than our type.
4299 For example, if we are dividing (X * 8) + (Y + 16) by 4, we can return
4300 (X * 2) + (Y + 4). We also canonicalize (X + 7) * 4 into X * 4 + 28
4301 in the hope that either the machine has a multiply-accumulate insn
4302 or that this is part of an addressing calculation.
4304 If we return a non-null expression, it is an equivalent form of the
4305 original computation, but need not be in the original type. */
4308 extract_muldiv (t, c, code, wide_type)
4311 enum tree_code code;
4314 tree type = TREE_TYPE (t);
4315 enum tree_code tcode = TREE_CODE (t);
4316 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
4317 > GET_MODE_SIZE (TYPE_MODE (type)))
4318 ? wide_type : type);
4320 int same_p = tcode == code;
4321 tree op0 = NULL_TREE, op1 = NULL_TREE;
4323 /* Don't deal with constants of zero here; they confuse the code below. */
4324 if (integer_zerop (c))
4327 if (TREE_CODE_CLASS (tcode) == '1')
4328 op0 = TREE_OPERAND (t, 0);
4330 if (TREE_CODE_CLASS (tcode) == '2')
4331 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
4333 /* Note that we need not handle conditional operations here since fold
4334 already handles those cases. So just do arithmetic here. */
4338 /* For a constant, we can always simplify if we are a multiply
4339 or (for divide and modulus) if it is a multiple of our constant. */
4340 if (code == MULT_EXPR
4341 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
4342 return const_binop (code, convert (ctype, t), convert (ctype, c), 0);
4345 case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
4347 /* Pass the constant down and see if we can make a simplification. If
4348 we can, replace this expression with the inner simplification for
4349 possible later conversion to our or some other type. */
4350 if (0 != (t1 = extract_muldiv (op0, convert (TREE_TYPE (op0), c), code,
4351 code == MULT_EXPR ? ctype : NULL_TREE)))
4355 case NEGATE_EXPR: case ABS_EXPR:
4356 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4357 return fold (build1 (tcode, ctype, convert (ctype, t1)));
4360 case MIN_EXPR: case MAX_EXPR:
4361 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
4362 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0
4363 && (t2 = extract_muldiv (op1, c, code, wide_type)) != 0)
4365 if (tree_int_cst_sgn (c) < 0)
4366 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
4368 return fold (build (tcode, ctype, convert (ctype, t1),
4369 convert (ctype, t2)));
4373 case WITH_RECORD_EXPR:
4374 if ((t1 = extract_muldiv (TREE_OPERAND (t, 0), c, code, wide_type)) != 0)
4375 return build (WITH_RECORD_EXPR, TREE_TYPE (t1), t1,
4376 TREE_OPERAND (t, 1));
4380 /* If this has not been evaluated and the operand has no side effects,
4381 we can see if we can do something inside it and make a new one.
4382 Note that this test is overly conservative since we can do this
4383 if the only reason it had side effects is that it was another
4384 similar SAVE_EXPR, but that isn't worth bothering with. */
4385 if (SAVE_EXPR_RTL (t) == 0 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0))
4386 && 0 != (t1 = extract_muldiv (TREE_OPERAND (t, 0), c, code,
4388 return save_expr (t1);
4391 case LSHIFT_EXPR: case RSHIFT_EXPR:
4392 /* If the second operand is constant, this is a multiplication
4393 or floor division, by a power of two, so we can treat it that
4394 way unless the multiplier or divisor overflows. */
4395 if (TREE_CODE (op1) == INTEGER_CST
4396 && 0 != (t1 = convert (ctype,
4397 const_binop (LSHIFT_EXPR, size_one_node,
4399 && ! TREE_OVERFLOW (t1))
4400 return extract_muldiv (build (tcode == LSHIFT_EXPR
4401 ? MULT_EXPR : FLOOR_DIV_EXPR,
4402 ctype, convert (ctype, op0), t1),
4403 c, code, wide_type);
4406 case PLUS_EXPR: case MINUS_EXPR:
4407 /* See if we can eliminate the operation on both sides. If we can, we
4408 can return a new PLUS or MINUS. If we can't, the only remaining
4409 cases where we can do anything are if the second operand is a
4411 t1 = extract_muldiv (op0, c, code, wide_type);
4412 t2 = extract_muldiv (op1, c, code, wide_type);
4413 if (t1 != 0 && t2 != 0)
4414 return fold (build (tcode, ctype, convert (ctype, t1),
4415 convert (ctype, t2)));
4417 /* If this was a subtraction, negate OP1 and set it to be an addition.
4418 This simplifies the logic below. */
4419 if (tcode == MINUS_EXPR)
4420 tcode = PLUS_EXPR, op1 = negate_expr (op1);
4422 if (TREE_CODE (op1) != INTEGER_CST)
4425 /* If either OP1 or C are negative, this optimization is not safe for
4426 some of the division and remainder types while for others we need
4427 to change the code. */
4428 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
4430 if (code == CEIL_DIV_EXPR)
4431 code = FLOOR_DIV_EXPR;
4432 else if (code == CEIL_MOD_EXPR)
4433 code = FLOOR_MOD_EXPR;
4434 else if (code == FLOOR_DIV_EXPR)
4435 code = CEIL_DIV_EXPR;
4436 else if (code == FLOOR_MOD_EXPR)
4437 code = CEIL_MOD_EXPR;
4438 else if (code != MULT_EXPR)
4442 /* Now do the operation and verify it doesn't overflow. */
4443 op1 = const_binop (code, convert (ctype, op1), convert (ctype, c), 0);
4444 if (op1 == 0 || TREE_OVERFLOW (op1))
4447 /* If we were able to eliminate our operation from the first side,
4448 apply our operation to the second side and reform the PLUS. */
4449 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
4450 return fold (build (tcode, ctype, convert (ctype, t1), op1));
4452 /* The last case is if we are a multiply. In that case, we can
4453 apply the distributive law to commute the multiply and addition
4454 if the multiplication of the constants doesn't overflow. */
4455 if (code == MULT_EXPR)
4456 return fold (build (tcode, ctype, fold (build (code, ctype,
4457 convert (ctype, op0),
4458 convert (ctype, c))),
4464 /* We have a special case here if we are doing something like
4465 (C * 8) % 4 since we know that's zero. */
4466 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
4467 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
4468 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
4469 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4470 return omit_one_operand (type, integer_zero_node, op0);
4472 /* ... fall through ... */
4474 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
4475 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
4476 /* If we can extract our operation from the LHS, do so and return a
4477 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
4478 do something only if the second operand is a constant. */
4480 && (t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4481 return fold (build (tcode, ctype, convert (ctype, t1),
4482 convert (ctype, op1)));
4483 else if (tcode == MULT_EXPR && code == MULT_EXPR
4484 && (t1 = extract_muldiv (op1, c, code, wide_type)) != 0)
4485 return fold (build (tcode, ctype, convert (ctype, op0),
4486 convert (ctype, t1)));
4487 else if (TREE_CODE (op1) != INTEGER_CST)
4490 /* If these are the same operation types, we can associate them
4491 assuming no overflow. */
4493 && 0 != (t1 = const_binop (MULT_EXPR, convert (ctype, op1),
4494 convert (ctype, c), 0))
4495 && ! TREE_OVERFLOW (t1))
4496 return fold (build (tcode, ctype, convert (ctype, op0), t1));
4498 /* If these operations "cancel" each other, we have the main
4499 optimizations of this pass, which occur when either constant is a
4500 multiple of the other, in which case we replace this with either an
4501 operation or CODE or TCODE. If we have an unsigned type that is
4502 not a sizetype, we canot do this for division since it will change
4503 the result if the original computation overflowed. */
4504 if ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR
4505 && (! TREE_UNSIGNED (ctype)
4506 || (TREE_CODE (ctype) == INTEGER_TYPE
4507 && TYPE_IS_SIZETYPE (ctype))))
4508 || (tcode == MULT_EXPR
4509 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
4510 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR))
4512 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4513 return fold (build (tcode, ctype, convert (ctype, op0),
4515 const_binop (TRUNC_DIV_EXPR,
4517 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
4518 return fold (build (code, ctype, convert (ctype, op0),
4520 const_binop (TRUNC_DIV_EXPR,
4532 /* If T contains a COMPOUND_EXPR which was inserted merely to evaluate
4533 S, a SAVE_EXPR, return the expression actually being evaluated. Note
4534 that we may sometimes modify the tree. */
4537 strip_compound_expr (t, s)
4541 enum tree_code code = TREE_CODE (t);
4543 /* See if this is the COMPOUND_EXPR we want to eliminate. */
4544 if (code == COMPOUND_EXPR && TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR
4545 && TREE_OPERAND (TREE_OPERAND (t, 0), 0) == s)
4546 return TREE_OPERAND (t, 1);
4548 /* See if this is a COND_EXPR or a simple arithmetic operator. We
4549 don't bother handling any other types. */
4550 else if (code == COND_EXPR)
4552 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4553 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4554 TREE_OPERAND (t, 2) = strip_compound_expr (TREE_OPERAND (t, 2), s);
4556 else if (TREE_CODE_CLASS (code) == '1')
4557 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4558 else if (TREE_CODE_CLASS (code) == '<'
4559 || TREE_CODE_CLASS (code) == '2')
4561 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4562 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4568 /* Return a node which has the indicated constant VALUE (either 0 or
4569 1), and is of the indicated TYPE. */
4572 constant_boolean_node (value, type)
4576 if (type == integer_type_node)
4577 return value ? integer_one_node : integer_zero_node;
4578 else if (TREE_CODE (type) == BOOLEAN_TYPE)
4579 return truthvalue_conversion (value ? integer_one_node :
4583 tree t = build_int_2 (value, 0);
4585 TREE_TYPE (t) = type;
4590 /* Utility function for the following routine, to see how complex a nesting of
4591 COND_EXPRs can be. EXPR is the expression and LIMIT is a count beyond which
4592 we don't care (to avoid spending too much time on complex expressions.). */
4595 count_cond (expr, lim)
4601 if (TREE_CODE (expr) != COND_EXPR)
4606 true = count_cond (TREE_OPERAND (expr, 1), lim - 1);
4607 false = count_cond (TREE_OPERAND (expr, 2), lim - 1 - true);
4608 return MIN (lim, 1 + true + false);
4611 /* Perform constant folding and related simplification of EXPR.
4612 The related simplifications include x*1 => x, x*0 => 0, etc.,
4613 and application of the associative law.
4614 NOP_EXPR conversions may be removed freely (as long as we
4615 are careful not to change the C type of the overall expression)
4616 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
4617 but we can constant-fold them if they have constant operands. */
4623 register tree t = expr;
4624 tree t1 = NULL_TREE;
4626 tree type = TREE_TYPE (expr);
4627 register tree arg0 = NULL_TREE, arg1 = NULL_TREE;
4628 register enum tree_code code = TREE_CODE (t);
4631 /* WINS will be nonzero when the switch is done
4632 if all operands are constant. */
4635 /* Don't try to process an RTL_EXPR since its operands aren't trees.
4636 Likewise for a SAVE_EXPR that's already been evaluated. */
4637 if (code == RTL_EXPR || (code == SAVE_EXPR && SAVE_EXPR_RTL (t)) != 0)
4640 /* Return right away if already constant. */
4641 if (TREE_CONSTANT (t))
4643 if (code == CONST_DECL)
4644 return DECL_INITIAL (t);
4648 #ifdef MAX_INTEGER_COMPUTATION_MODE
4649 check_max_integer_computation_mode (expr);
4652 kind = TREE_CODE_CLASS (code);
4653 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
4657 /* Special case for conversion ops that can have fixed point args. */
4658 arg0 = TREE_OPERAND (t, 0);
4660 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
4662 STRIP_SIGN_NOPS (arg0);
4664 if (arg0 != 0 && TREE_CODE (arg0) == COMPLEX_CST)
4665 subop = TREE_REALPART (arg0);
4669 if (subop != 0 && TREE_CODE (subop) != INTEGER_CST
4670 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
4671 && TREE_CODE (subop) != REAL_CST
4672 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
4674 /* Note that TREE_CONSTANT isn't enough:
4675 static var addresses are constant but we can't
4676 do arithmetic on them. */
4679 else if (kind == 'e' || kind == '<'
4680 || kind == '1' || kind == '2' || kind == 'r')
4682 register int len = tree_code_length[(int) code];
4684 for (i = 0; i < len; i++)
4686 tree op = TREE_OPERAND (t, i);
4690 continue; /* Valid for CALL_EXPR, at least. */
4692 if (kind == '<' || code == RSHIFT_EXPR)
4694 /* Signedness matters here. Perhaps we can refine this
4696 STRIP_SIGN_NOPS (op);
4700 /* Strip any conversions that don't change the mode. */
4704 if (TREE_CODE (op) == COMPLEX_CST)
4705 subop = TREE_REALPART (op);
4709 if (TREE_CODE (subop) != INTEGER_CST
4710 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
4711 && TREE_CODE (subop) != REAL_CST
4712 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
4714 /* Note that TREE_CONSTANT isn't enough:
4715 static var addresses are constant but we can't
4716 do arithmetic on them. */
4726 /* If this is a commutative operation, and ARG0 is a constant, move it
4727 to ARG1 to reduce the number of tests below. */
4728 if ((code == PLUS_EXPR || code == MULT_EXPR || code == MIN_EXPR
4729 || code == MAX_EXPR || code == BIT_IOR_EXPR || code == BIT_XOR_EXPR
4730 || code == BIT_AND_EXPR)
4731 && (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST))
4733 tem = arg0; arg0 = arg1; arg1 = tem;
4735 tem = TREE_OPERAND (t, 0); TREE_OPERAND (t, 0) = TREE_OPERAND (t, 1);
4736 TREE_OPERAND (t, 1) = tem;
4739 /* Now WINS is set as described above,
4740 ARG0 is the first operand of EXPR,
4741 and ARG1 is the second operand (if it has more than one operand).
4743 First check for cases where an arithmetic operation is applied to a
4744 compound, conditional, or comparison operation. Push the arithmetic
4745 operation inside the compound or conditional to see if any folding
4746 can then be done. Convert comparison to conditional for this purpose.
4747 The also optimizes non-constant cases that used to be done in
4750 Before we do that, see if this is a BIT_AND_EXPR or a BIT_OR_EXPR,
4751 one of the operands is a comparison and the other is a comparison, a
4752 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
4753 code below would make the expression more complex. Change it to a
4754 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
4755 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
4757 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
4758 || code == EQ_EXPR || code == NE_EXPR)
4759 && ((truth_value_p (TREE_CODE (arg0))
4760 && (truth_value_p (TREE_CODE (arg1))
4761 || (TREE_CODE (arg1) == BIT_AND_EXPR
4762 && integer_onep (TREE_OPERAND (arg1, 1)))))
4763 || (truth_value_p (TREE_CODE (arg1))
4764 && (truth_value_p (TREE_CODE (arg0))
4765 || (TREE_CODE (arg0) == BIT_AND_EXPR
4766 && integer_onep (TREE_OPERAND (arg0, 1)))))))
4768 t = fold (build (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
4769 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
4773 if (code == EQ_EXPR)
4774 t = invert_truthvalue (t);
4779 if (TREE_CODE_CLASS (code) == '1')
4781 if (TREE_CODE (arg0) == COMPOUND_EXPR)
4782 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
4783 fold (build1 (code, type, TREE_OPERAND (arg0, 1))));
4784 else if (TREE_CODE (arg0) == COND_EXPR)
4786 t = fold (build (COND_EXPR, type, TREE_OPERAND (arg0, 0),
4787 fold (build1 (code, type, TREE_OPERAND (arg0, 1))),
4788 fold (build1 (code, type, TREE_OPERAND (arg0, 2)))));
4790 /* If this was a conversion, and all we did was to move into
4791 inside the COND_EXPR, bring it back out. But leave it if
4792 it is a conversion from integer to integer and the
4793 result precision is no wider than a word since such a
4794 conversion is cheap and may be optimized away by combine,
4795 while it couldn't if it were outside the COND_EXPR. Then return
4796 so we don't get into an infinite recursion loop taking the
4797 conversion out and then back in. */
4799 if ((code == NOP_EXPR || code == CONVERT_EXPR
4800 || code == NON_LVALUE_EXPR)
4801 && TREE_CODE (t) == COND_EXPR
4802 && TREE_CODE (TREE_OPERAND (t, 1)) == code
4803 && TREE_CODE (TREE_OPERAND (t, 2)) == code
4804 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))
4805 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 2), 0)))
4806 && ! (INTEGRAL_TYPE_P (TREE_TYPE (t))
4808 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))))
4809 && TYPE_PRECISION (TREE_TYPE (t)) <= BITS_PER_WORD))
4810 t = build1 (code, type,
4812 TREE_TYPE (TREE_OPERAND
4813 (TREE_OPERAND (t, 1), 0)),
4814 TREE_OPERAND (t, 0),
4815 TREE_OPERAND (TREE_OPERAND (t, 1), 0),
4816 TREE_OPERAND (TREE_OPERAND (t, 2), 0)));
4819 else if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<')
4820 return fold (build (COND_EXPR, type, arg0,
4821 fold (build1 (code, type, integer_one_node)),
4822 fold (build1 (code, type, integer_zero_node))));
4824 else if (TREE_CODE_CLASS (code) == '2'
4825 || TREE_CODE_CLASS (code) == '<')
4827 if (TREE_CODE (arg1) == COMPOUND_EXPR)
4828 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
4829 fold (build (code, type,
4830 arg0, TREE_OPERAND (arg1, 1))));
4831 else if ((TREE_CODE (arg1) == COND_EXPR
4832 || (TREE_CODE_CLASS (TREE_CODE (arg1)) == '<'
4833 && TREE_CODE_CLASS (code) != '<'))
4834 && (TREE_CODE (arg0) != COND_EXPR
4835 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
4836 && (! TREE_SIDE_EFFECTS (arg0)
4837 || (global_bindings_p () == 0
4838 && ! contains_placeholder_p (arg0))))
4840 tree test, true_value, false_value;
4841 tree lhs = 0, rhs = 0;
4843 if (TREE_CODE (arg1) == COND_EXPR)
4845 test = TREE_OPERAND (arg1, 0);
4846 true_value = TREE_OPERAND (arg1, 1);
4847 false_value = TREE_OPERAND (arg1, 2);
4851 tree testtype = TREE_TYPE (arg1);
4853 true_value = convert (testtype, integer_one_node);
4854 false_value = convert (testtype, integer_zero_node);
4857 /* If ARG0 is complex we want to make sure we only evaluate
4858 it once. Though this is only required if it is volatile, it
4859 might be more efficient even if it is not. However, if we
4860 succeed in folding one part to a constant, we do not need
4861 to make this SAVE_EXPR. Since we do this optimization
4862 primarily to see if we do end up with constant and this
4863 SAVE_EXPR interferes with later optimizations, suppressing
4864 it when we can is important.
4866 If we are not in a function, we can't make a SAVE_EXPR, so don't
4867 try to do so. Don't try to see if the result is a constant
4868 if an arm is a COND_EXPR since we get exponential behavior
4871 if (TREE_CODE (arg0) != SAVE_EXPR && ! TREE_CONSTANT (arg0)
4872 && global_bindings_p () == 0
4873 && ((TREE_CODE (arg0) != VAR_DECL
4874 && TREE_CODE (arg0) != PARM_DECL)
4875 || TREE_SIDE_EFFECTS (arg0)))
4877 if (TREE_CODE (true_value) != COND_EXPR)
4878 lhs = fold (build (code, type, arg0, true_value));
4880 if (TREE_CODE (false_value) != COND_EXPR)
4881 rhs = fold (build (code, type, arg0, false_value));
4883 if ((lhs == 0 || ! TREE_CONSTANT (lhs))
4884 && (rhs == 0 || !TREE_CONSTANT (rhs)))
4885 arg0 = save_expr (arg0), lhs = rhs = 0;
4889 lhs = fold (build (code, type, arg0, true_value));
4891 rhs = fold (build (code, type, arg0, false_value));
4893 test = fold (build (COND_EXPR, type, test, lhs, rhs));
4895 if (TREE_CODE (arg0) == SAVE_EXPR)
4896 return build (COMPOUND_EXPR, type,
4897 convert (void_type_node, arg0),
4898 strip_compound_expr (test, arg0));
4900 return convert (type, test);
4903 else if (TREE_CODE (arg0) == COMPOUND_EXPR)
4904 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
4905 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
4906 else if ((TREE_CODE (arg0) == COND_EXPR
4907 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
4908 && TREE_CODE_CLASS (code) != '<'))
4909 && (TREE_CODE (arg1) != COND_EXPR
4910 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
4911 && (! TREE_SIDE_EFFECTS (arg1)
4912 || (global_bindings_p () == 0
4913 && ! contains_placeholder_p (arg1))))
4915 tree test, true_value, false_value;
4916 tree lhs = 0, rhs = 0;
4918 if (TREE_CODE (arg0) == COND_EXPR)
4920 test = TREE_OPERAND (arg0, 0);
4921 true_value = TREE_OPERAND (arg0, 1);
4922 false_value = TREE_OPERAND (arg0, 2);
4926 tree testtype = TREE_TYPE (arg0);
4928 true_value = convert (testtype, integer_one_node);
4929 false_value = convert (testtype, integer_zero_node);
4932 if (TREE_CODE (arg1) != SAVE_EXPR && ! TREE_CONSTANT (arg0)
4933 && global_bindings_p () == 0
4934 && ((TREE_CODE (arg1) != VAR_DECL
4935 && TREE_CODE (arg1) != PARM_DECL)
4936 || TREE_SIDE_EFFECTS (arg1)))
4938 if (TREE_CODE (true_value) != COND_EXPR)
4939 lhs = fold (build (code, type, true_value, arg1));
4941 if (TREE_CODE (false_value) != COND_EXPR)
4942 rhs = fold (build (code, type, false_value, arg1));
4944 if ((lhs == 0 || ! TREE_CONSTANT (lhs))
4945 && (rhs == 0 || !TREE_CONSTANT (rhs)))
4946 arg1 = save_expr (arg1), lhs = rhs = 0;
4950 lhs = fold (build (code, type, true_value, arg1));
4953 rhs = fold (build (code, type, false_value, arg1));
4955 test = fold (build (COND_EXPR, type, test, lhs, rhs));
4956 if (TREE_CODE (arg1) == SAVE_EXPR)
4957 return build (COMPOUND_EXPR, type,
4958 convert (void_type_node, arg1),
4959 strip_compound_expr (test, arg1));
4961 return convert (type, test);
4964 else if (TREE_CODE_CLASS (code) == '<'
4965 && TREE_CODE (arg0) == COMPOUND_EXPR)
4966 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
4967 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
4968 else if (TREE_CODE_CLASS (code) == '<'
4969 && TREE_CODE (arg1) == COMPOUND_EXPR)
4970 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
4971 fold (build (code, type, arg0, TREE_OPERAND (arg1, 1))));
4983 return fold (DECL_INITIAL (t));
4988 case FIX_TRUNC_EXPR:
4989 /* Other kinds of FIX are not handled properly by fold_convert. */
4991 if (TREE_TYPE (TREE_OPERAND (t, 0)) == TREE_TYPE (t))
4992 return TREE_OPERAND (t, 0);
4994 /* Handle cases of two conversions in a row. */
4995 if (TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
4996 || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR)
4998 tree inside_type = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
4999 tree inter_type = TREE_TYPE (TREE_OPERAND (t, 0));
5000 tree final_type = TREE_TYPE (t);
5001 int inside_int = INTEGRAL_TYPE_P (inside_type);
5002 int inside_ptr = POINTER_TYPE_P (inside_type);
5003 int inside_float = FLOAT_TYPE_P (inside_type);
5004 int inside_prec = TYPE_PRECISION (inside_type);
5005 int inside_unsignedp = TREE_UNSIGNED (inside_type);
5006 int inter_int = INTEGRAL_TYPE_P (inter_type);
5007 int inter_ptr = POINTER_TYPE_P (inter_type);
5008 int inter_float = FLOAT_TYPE_P (inter_type);
5009 int inter_prec = TYPE_PRECISION (inter_type);
5010 int inter_unsignedp = TREE_UNSIGNED (inter_type);
5011 int final_int = INTEGRAL_TYPE_P (final_type);
5012 int final_ptr = POINTER_TYPE_P (final_type);
5013 int final_float = FLOAT_TYPE_P (final_type);
5014 int final_prec = TYPE_PRECISION (final_type);
5015 int final_unsignedp = TREE_UNSIGNED (final_type);
5017 /* In addition to the cases of two conversions in a row
5018 handled below, if we are converting something to its own
5019 type via an object of identical or wider precision, neither
5020 conversion is needed. */
5021 if (inside_type == final_type
5022 && ((inter_int && final_int) || (inter_float && final_float))
5023 && inter_prec >= final_prec)
5024 return TREE_OPERAND (TREE_OPERAND (t, 0), 0);
5026 /* Likewise, if the intermediate and final types are either both
5027 float or both integer, we don't need the middle conversion if
5028 it is wider than the final type and doesn't change the signedness
5029 (for integers). Avoid this if the final type is a pointer
5030 since then we sometimes need the inner conversion. Likewise if
5031 the outer has a precision not equal to the size of its mode. */
5032 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
5033 || (inter_float && inside_float))
5034 && inter_prec >= inside_prec
5035 && (inter_float || inter_unsignedp == inside_unsignedp)
5036 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
5037 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
5039 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5041 /* If we have a sign-extension of a zero-extended value, we can
5042 replace that by a single zero-extension. */
5043 if (inside_int && inter_int && final_int
5044 && inside_prec < inter_prec && inter_prec < final_prec
5045 && inside_unsignedp && !inter_unsignedp)
5046 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5048 /* Two conversions in a row are not needed unless:
5049 - some conversion is floating-point (overstrict for now), or
5050 - the intermediate type is narrower than both initial and
5052 - the intermediate type and innermost type differ in signedness,
5053 and the outermost type is wider than the intermediate, or
5054 - the initial type is a pointer type and the precisions of the
5055 intermediate and final types differ, or
5056 - the final type is a pointer type and the precisions of the
5057 initial and intermediate types differ. */
5058 if (! inside_float && ! inter_float && ! final_float
5059 && (inter_prec > inside_prec || inter_prec > final_prec)
5060 && ! (inside_int && inter_int
5061 && inter_unsignedp != inside_unsignedp
5062 && inter_prec < final_prec)
5063 && ((inter_unsignedp && inter_prec > inside_prec)
5064 == (final_unsignedp && final_prec > inter_prec))
5065 && ! (inside_ptr && inter_prec != final_prec)
5066 && ! (final_ptr && inside_prec != inter_prec)
5067 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
5068 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
5070 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5073 if (TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR
5074 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t, 0), 1))
5075 /* Detect assigning a bitfield. */
5076 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) == COMPONENT_REF
5077 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 1))))
5079 /* Don't leave an assignment inside a conversion
5080 unless assigning a bitfield. */
5081 tree prev = TREE_OPERAND (t, 0);
5082 TREE_OPERAND (t, 0) = TREE_OPERAND (prev, 1);
5083 /* First do the assignment, then return converted constant. */
5084 t = build (COMPOUND_EXPR, TREE_TYPE (t), prev, fold (t));
5090 TREE_CONSTANT (t) = TREE_CONSTANT (arg0);
5093 return fold_convert (t, arg0);
5095 #if 0 /* This loses on &"foo"[0]. */
5100 /* Fold an expression like: "foo"[2] */
5101 if (TREE_CODE (arg0) == STRING_CST
5102 && TREE_CODE (arg1) == INTEGER_CST
5103 && !TREE_INT_CST_HIGH (arg1)
5104 && (i = TREE_INT_CST_LOW (arg1)) < TREE_STRING_LENGTH (arg0))
5106 t = build_int_2 (TREE_STRING_POINTER (arg0)[i], 0);
5107 TREE_TYPE (t) = TREE_TYPE (TREE_TYPE (arg0));
5108 force_fit_type (t, 0);
5115 if (TREE_CODE (arg0) == CONSTRUCTOR)
5117 tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0));
5124 TREE_CONSTANT (t) = wins;
5130 if (TREE_CODE (arg0) == INTEGER_CST)
5132 HOST_WIDE_INT low, high;
5133 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
5134 TREE_INT_CST_HIGH (arg0),
5136 t = build_int_2 (low, high);
5137 TREE_TYPE (t) = type;
5139 = (TREE_OVERFLOW (arg0)
5140 | force_fit_type (t, overflow && !TREE_UNSIGNED (type)));
5141 TREE_CONSTANT_OVERFLOW (t)
5142 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
5144 else if (TREE_CODE (arg0) == REAL_CST)
5145 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
5147 else if (TREE_CODE (arg0) == NEGATE_EXPR)
5148 return TREE_OPERAND (arg0, 0);
5150 /* Convert - (a - b) to (b - a) for non-floating-point. */
5151 else if (TREE_CODE (arg0) == MINUS_EXPR
5152 && (! FLOAT_TYPE_P (type) || flag_fast_math))
5153 return build (MINUS_EXPR, type, TREE_OPERAND (arg0, 1),
5154 TREE_OPERAND (arg0, 0));
5161 if (TREE_CODE (arg0) == INTEGER_CST)
5163 if (! TREE_UNSIGNED (type)
5164 && TREE_INT_CST_HIGH (arg0) < 0)
5166 HOST_WIDE_INT low, high;
5167 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
5168 TREE_INT_CST_HIGH (arg0),
5170 t = build_int_2 (low, high);
5171 TREE_TYPE (t) = type;
5173 = (TREE_OVERFLOW (arg0)
5174 | force_fit_type (t, overflow));
5175 TREE_CONSTANT_OVERFLOW (t)
5176 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
5179 else if (TREE_CODE (arg0) == REAL_CST)
5181 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
5182 t = build_real (type,
5183 REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
5186 else if (TREE_CODE (arg0) == ABS_EXPR || TREE_CODE (arg0) == NEGATE_EXPR)
5187 return build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0));
5191 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
5193 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
5194 return build (COMPLEX_EXPR, TREE_TYPE (arg0),
5195 TREE_OPERAND (arg0, 0),
5196 negate_expr (TREE_OPERAND (arg0, 1)));
5197 else if (TREE_CODE (arg0) == COMPLEX_CST)
5198 return build_complex (type, TREE_OPERAND (arg0, 0),
5199 negate_expr (TREE_OPERAND (arg0, 1)));
5200 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
5201 return fold (build (TREE_CODE (arg0), type,
5202 fold (build1 (CONJ_EXPR, type,
5203 TREE_OPERAND (arg0, 0))),
5204 fold (build1 (CONJ_EXPR,
5205 type, TREE_OPERAND (arg0, 1)))));
5206 else if (TREE_CODE (arg0) == CONJ_EXPR)
5207 return TREE_OPERAND (arg0, 0);
5213 t = build_int_2 (~ TREE_INT_CST_LOW (arg0),
5214 ~ TREE_INT_CST_HIGH (arg0));
5215 TREE_TYPE (t) = type;
5216 force_fit_type (t, 0);
5217 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg0);
5218 TREE_CONSTANT_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (arg0);
5220 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
5221 return TREE_OPERAND (arg0, 0);
5225 /* A + (-B) -> A - B */
5226 if (TREE_CODE (arg1) == NEGATE_EXPR)
5227 return fold (build (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5228 /* (-A) + B -> B - A */
5229 if (TREE_CODE (arg0) == NEGATE_EXPR)
5230 return fold (build (MINUS_EXPR, type, arg1, TREE_OPERAND (arg0, 0)));
5231 else if (! FLOAT_TYPE_P (type))
5233 if (integer_zerop (arg1))
5234 return non_lvalue (convert (type, arg0));
5236 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
5237 with a constant, and the two constants have no bits in common,
5238 we should treat this as a BIT_IOR_EXPR since this may produce more
5240 if (TREE_CODE (arg0) == BIT_AND_EXPR
5241 && TREE_CODE (arg1) == BIT_AND_EXPR
5242 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5243 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
5244 && integer_zerop (const_binop (BIT_AND_EXPR,
5245 TREE_OPERAND (arg0, 1),
5246 TREE_OPERAND (arg1, 1), 0)))
5248 code = BIT_IOR_EXPR;
5252 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
5253 (plus (plus (mult) (mult)) (foo)) so that we can
5254 take advantage of the factoring cases below. */
5255 if ((TREE_CODE (arg0) == PLUS_EXPR
5256 && TREE_CODE (arg1) == MULT_EXPR)
5257 || (TREE_CODE (arg1) == PLUS_EXPR
5258 && TREE_CODE (arg0) == MULT_EXPR))
5260 tree parg0, parg1, parg, marg;
5262 if (TREE_CODE (arg0) == PLUS_EXPR)
5263 parg = arg0, marg = arg1;
5265 parg = arg1, marg = arg0;
5266 parg0 = TREE_OPERAND (parg, 0);
5267 parg1 = TREE_OPERAND (parg, 1);
5271 if (TREE_CODE (parg0) == MULT_EXPR
5272 && TREE_CODE (parg1) != MULT_EXPR)
5273 return fold (build (PLUS_EXPR, type,
5274 fold (build (PLUS_EXPR, type, parg0, marg)),
5276 if (TREE_CODE (parg0) != MULT_EXPR
5277 && TREE_CODE (parg1) == MULT_EXPR)
5278 return fold (build (PLUS_EXPR, type,
5279 fold (build (PLUS_EXPR, type, parg1, marg)),
5283 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR)
5285 tree arg00, arg01, arg10, arg11;
5286 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
5288 /* (A * C) + (B * C) -> (A+B) * C.
5289 We are most concerned about the case where C is a constant,
5290 but other combinations show up during loop reduction. Since
5291 it is not difficult, try all four possibilities. */
5293 arg00 = TREE_OPERAND (arg0, 0);
5294 arg01 = TREE_OPERAND (arg0, 1);
5295 arg10 = TREE_OPERAND (arg1, 0);
5296 arg11 = TREE_OPERAND (arg1, 1);
5299 if (operand_equal_p (arg01, arg11, 0))
5300 same = arg01, alt0 = arg00, alt1 = arg10;
5301 else if (operand_equal_p (arg00, arg10, 0))
5302 same = arg00, alt0 = arg01, alt1 = arg11;
5303 else if (operand_equal_p (arg00, arg11, 0))
5304 same = arg00, alt0 = arg01, alt1 = arg10;
5305 else if (operand_equal_p (arg01, arg10, 0))
5306 same = arg01, alt0 = arg00, alt1 = arg11;
5308 /* No identical multiplicands; see if we can find a common
5309 power-of-two factor in non-power-of-two multiplies. This
5310 can help in multi-dimensional array access. */
5311 else if (TREE_CODE (arg01) == INTEGER_CST
5312 && TREE_CODE (arg11) == INTEGER_CST
5313 && TREE_INT_CST_HIGH (arg01) == 0
5314 && TREE_INT_CST_HIGH (arg11) == 0)
5316 HOST_WIDE_INT int01, int11, tmp;
5317 int01 = TREE_INT_CST_LOW (arg01);
5318 int11 = TREE_INT_CST_LOW (arg11);
5320 /* Move min of absolute values to int11. */
5321 if ((int01 >= 0 ? int01 : -int01)
5322 < (int11 >= 0 ? int11 : -int11))
5324 tmp = int01, int01 = int11, int11 = tmp;
5325 alt0 = arg00, arg00 = arg10, arg10 = alt0;
5326 alt0 = arg01, arg01 = arg11, arg11 = alt0;
5329 if (exact_log2 (int11) > 0 && int01 % int11 == 0)
5331 alt0 = fold (build (MULT_EXPR, type, arg00,
5332 build_int_2 (int01 / int11, 0)));
5339 return fold (build (MULT_EXPR, type,
5340 fold (build (PLUS_EXPR, type, alt0, alt1)),
5344 /* In IEEE floating point, x+0 may not equal x. */
5345 else if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
5347 && real_zerop (arg1))
5348 return non_lvalue (convert (type, arg0));
5349 /* x+(-0) equals x, even for IEEE. */
5350 else if (TREE_CODE (arg1) == REAL_CST
5351 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (arg1)))
5352 return non_lvalue (convert (type, arg0));
5355 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
5356 is a rotate of A by C1 bits. */
5357 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
5358 is a rotate of A by B bits. */
5360 register enum tree_code code0, code1;
5361 code0 = TREE_CODE (arg0);
5362 code1 = TREE_CODE (arg1);
5363 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
5364 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
5365 && operand_equal_p (TREE_OPERAND (arg0, 0),
5366 TREE_OPERAND (arg1,0), 0)
5367 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5369 register tree tree01, tree11;
5370 register enum tree_code code01, code11;
5372 tree01 = TREE_OPERAND (arg0, 1);
5373 tree11 = TREE_OPERAND (arg1, 1);
5374 STRIP_NOPS (tree01);
5375 STRIP_NOPS (tree11);
5376 code01 = TREE_CODE (tree01);
5377 code11 = TREE_CODE (tree11);
5378 if (code01 == INTEGER_CST
5379 && code11 == INTEGER_CST
5380 && TREE_INT_CST_HIGH (tree01) == 0
5381 && TREE_INT_CST_HIGH (tree11) == 0
5382 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
5383 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
5384 return build (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
5385 code0 == LSHIFT_EXPR ? tree01 : tree11);
5386 else if (code11 == MINUS_EXPR)
5388 tree tree110, tree111;
5389 tree110 = TREE_OPERAND (tree11, 0);
5390 tree111 = TREE_OPERAND (tree11, 1);
5391 STRIP_NOPS (tree110);
5392 STRIP_NOPS (tree111);
5393 if (TREE_CODE (tree110) == INTEGER_CST
5394 && TREE_INT_CST_HIGH (tree110) == 0
5395 && (TREE_INT_CST_LOW (tree110)
5396 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5397 && operand_equal_p (tree01, tree111, 0))
5398 return build ((code0 == LSHIFT_EXPR
5401 type, TREE_OPERAND (arg0, 0), tree01);
5403 else if (code01 == MINUS_EXPR)
5405 tree tree010, tree011;
5406 tree010 = TREE_OPERAND (tree01, 0);
5407 tree011 = TREE_OPERAND (tree01, 1);
5408 STRIP_NOPS (tree010);
5409 STRIP_NOPS (tree011);
5410 if (TREE_CODE (tree010) == INTEGER_CST
5411 && TREE_INT_CST_HIGH (tree010) == 0
5412 && (TREE_INT_CST_LOW (tree010)
5413 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5414 && operand_equal_p (tree11, tree011, 0))
5415 return build ((code0 != LSHIFT_EXPR
5418 type, TREE_OPERAND (arg0, 0), tree11);
5425 /* In most languages, can't associate operations on floats through
5426 parentheses. Rather than remember where the parentheses were, we
5427 don't associate floats at all. It shouldn't matter much. However,
5428 associating multiplications is only very slightly inaccurate, so do
5429 that if -ffast-math is specified. */
5432 && (! FLOAT_TYPE_P (type)
5433 || (flag_fast_math && code != MULT_EXPR)))
5435 tree var0, con0, lit0, var1, con1, lit1;
5437 /* Split both trees into variables, constants, and literals. Then
5438 associate each group together, the constants with literals,
5439 then the result with variables. This increases the chances of
5440 literals being recombined later and of generating relocatable
5441 expressions for the sum of a constant and literal. */
5442 var0 = split_tree (arg0, code, &con0, &lit0, 0);
5443 var1 = split_tree (arg1, code, &con1, &lit1, code == MINUS_EXPR);
5445 /* Only do something if we found more than two objects. Otherwise,
5446 nothing has changed and we risk infinite recursion. */
5447 if (2 < ((var0 != 0) + (var1 != 0) + (con0 != 0) + (con1 != 0)
5448 + (lit0 != 0) + (lit1 != 0)))
5450 var0 = associate_trees (var0, var1, code, type);
5451 con0 = associate_trees (con0, con1, code, type);
5452 lit0 = associate_trees (lit0, lit1, code, type);
5453 con0 = associate_trees (con0, lit0, code, type);
5454 return convert (type, associate_trees (var0, con0, code, type));
5459 #if defined (REAL_IS_NOT_DOUBLE) && ! defined (REAL_ARITHMETIC)
5460 if (TREE_CODE (arg1) == REAL_CST)
5462 #endif /* REAL_IS_NOT_DOUBLE, and no REAL_ARITHMETIC */
5464 t1 = const_binop (code, arg0, arg1, 0);
5465 if (t1 != NULL_TREE)
5467 /* The return value should always have
5468 the same type as the original expression. */
5469 if (TREE_TYPE (t1) != TREE_TYPE (t))
5470 t1 = convert (TREE_TYPE (t), t1);
5477 /* A - (-B) -> A + B */
5478 if (TREE_CODE (arg1) == NEGATE_EXPR)
5479 return fold (build (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5480 /* (-A) - CST -> (-CST) - A for floating point (what about ints ?) */
5481 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == REAL_CST)
5483 fold (build (MINUS_EXPR, type,
5484 build_real (TREE_TYPE (arg1),
5485 REAL_VALUE_NEGATE (TREE_REAL_CST (arg1))),
5486 TREE_OPERAND (arg0, 0)));
5488 if (! FLOAT_TYPE_P (type))
5490 if (! wins && integer_zerop (arg0))
5491 return negate_expr (arg1);
5492 if (integer_zerop (arg1))
5493 return non_lvalue (convert (type, arg0));
5495 /* (A * C) - (B * C) -> (A-B) * C. Since we are most concerned
5496 about the case where C is a constant, just try one of the
5497 four possibilities. */
5499 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR
5500 && operand_equal_p (TREE_OPERAND (arg0, 1),
5501 TREE_OPERAND (arg1, 1), 0))
5502 return fold (build (MULT_EXPR, type,
5503 fold (build (MINUS_EXPR, type,
5504 TREE_OPERAND (arg0, 0),
5505 TREE_OPERAND (arg1, 0))),
5506 TREE_OPERAND (arg0, 1)));
5509 else if (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
5512 /* Except with IEEE floating point, 0-x equals -x. */
5513 if (! wins && real_zerop (arg0))
5514 return negate_expr (arg1);
5515 /* Except with IEEE floating point, x-0 equals x. */
5516 if (real_zerop (arg1))
5517 return non_lvalue (convert (type, arg0));
5520 /* Fold &x - &x. This can happen from &x.foo - &x.
5521 This is unsafe for certain floats even in non-IEEE formats.
5522 In IEEE, it is unsafe because it does wrong for NaNs.
5523 Also note that operand_equal_p is always false if an operand
5526 if ((! FLOAT_TYPE_P (type) || flag_fast_math)
5527 && operand_equal_p (arg0, arg1, 0))
5528 return convert (type, integer_zero_node);
5533 /* (-A) * (-B) -> A * B */
5534 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR)
5535 return fold (build (MULT_EXPR, type, TREE_OPERAND (arg0, 0),
5536 TREE_OPERAND (arg1, 0)));
5538 if (! FLOAT_TYPE_P (type))
5540 if (integer_zerop (arg1))
5541 return omit_one_operand (type, arg1, arg0);
5542 if (integer_onep (arg1))
5543 return non_lvalue (convert (type, arg0));
5545 /* (a * (1 << b)) is (a << b) */
5546 if (TREE_CODE (arg1) == LSHIFT_EXPR
5547 && integer_onep (TREE_OPERAND (arg1, 0)))
5548 return fold (build (LSHIFT_EXPR, type, arg0,
5549 TREE_OPERAND (arg1, 1)));
5550 if (TREE_CODE (arg0) == LSHIFT_EXPR
5551 && integer_onep (TREE_OPERAND (arg0, 0)))
5552 return fold (build (LSHIFT_EXPR, type, arg1,
5553 TREE_OPERAND (arg0, 1)));
5555 if (TREE_CODE (arg1) == INTEGER_CST
5556 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
5558 return convert (type, tem);
5563 /* x*0 is 0, except for IEEE floating point. */
5564 if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
5566 && real_zerop (arg1))
5567 return omit_one_operand (type, arg1, arg0);
5568 /* In IEEE floating point, x*1 is not equivalent to x for snans.
5569 However, ANSI says we can drop signals,
5570 so we can do this anyway. */
5571 if (real_onep (arg1))
5572 return non_lvalue (convert (type, arg0));
5574 if (! wins && real_twop (arg1) && global_bindings_p () == 0
5575 && ! contains_placeholder_p (arg0))
5577 tree arg = save_expr (arg0);
5578 return build (PLUS_EXPR, type, arg, arg);
5585 if (integer_all_onesp (arg1))
5586 return omit_one_operand (type, arg1, arg0);
5587 if (integer_zerop (arg1))
5588 return non_lvalue (convert (type, arg0));
5589 t1 = distribute_bit_expr (code, type, arg0, arg1);
5590 if (t1 != NULL_TREE)
5593 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
5595 This results in more efficient code for machines without a NAND
5596 instruction. Combine will canonicalize to the first form
5597 which will allow use of NAND instructions provided by the
5598 backend if they exist. */
5599 if (TREE_CODE (arg0) == BIT_NOT_EXPR
5600 && TREE_CODE (arg1) == BIT_NOT_EXPR)
5602 return fold (build1 (BIT_NOT_EXPR, type,
5603 build (BIT_AND_EXPR, type,
5604 TREE_OPERAND (arg0, 0),
5605 TREE_OPERAND (arg1, 0))));
5608 /* See if this can be simplified into a rotate first. If that
5609 is unsuccessful continue in the association code. */
5613 if (integer_zerop (arg1))
5614 return non_lvalue (convert (type, arg0));
5615 if (integer_all_onesp (arg1))
5616 return fold (build1 (BIT_NOT_EXPR, type, arg0));
5618 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
5619 with a constant, and the two constants have no bits in common,
5620 we should treat this as a BIT_IOR_EXPR since this may produce more
5622 if (TREE_CODE (arg0) == BIT_AND_EXPR
5623 && TREE_CODE (arg1) == BIT_AND_EXPR
5624 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5625 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
5626 && integer_zerop (const_binop (BIT_AND_EXPR,
5627 TREE_OPERAND (arg0, 1),
5628 TREE_OPERAND (arg1, 1), 0)))
5630 code = BIT_IOR_EXPR;
5634 /* See if this can be simplified into a rotate first. If that
5635 is unsuccessful continue in the association code. */
5640 if (integer_all_onesp (arg1))
5641 return non_lvalue (convert (type, arg0));
5642 if (integer_zerop (arg1))
5643 return omit_one_operand (type, arg1, arg0);
5644 t1 = distribute_bit_expr (code, type, arg0, arg1);
5645 if (t1 != NULL_TREE)
5647 /* Simplify ((int)c & 0x377) into (int)c, if c is unsigned char. */
5648 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == NOP_EXPR
5649 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg1, 0))))
5651 int prec = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg1, 0)));
5652 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
5653 && (~TREE_INT_CST_LOW (arg0)
5654 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
5655 return build1 (NOP_EXPR, type, TREE_OPERAND (arg1, 0));
5657 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
5658 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5660 int prec = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
5661 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
5662 && (~TREE_INT_CST_LOW (arg1)
5663 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
5664 return build1 (NOP_EXPR, type, TREE_OPERAND (arg0, 0));
5667 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
5669 This results in more efficient code for machines without a NOR
5670 instruction. Combine will canonicalize to the first form
5671 which will allow use of NOR instructions provided by the
5672 backend if they exist. */
5673 if (TREE_CODE (arg0) == BIT_NOT_EXPR
5674 && TREE_CODE (arg1) == BIT_NOT_EXPR)
5676 return fold (build1 (BIT_NOT_EXPR, type,
5677 build (BIT_IOR_EXPR, type,
5678 TREE_OPERAND (arg0, 0),
5679 TREE_OPERAND (arg1, 0))));
5684 case BIT_ANDTC_EXPR:
5685 if (integer_all_onesp (arg0))
5686 return non_lvalue (convert (type, arg1));
5687 if (integer_zerop (arg0))
5688 return omit_one_operand (type, arg0, arg1);
5689 if (TREE_CODE (arg1) == INTEGER_CST)
5691 arg1 = fold (build1 (BIT_NOT_EXPR, type, arg1));
5692 code = BIT_AND_EXPR;
5698 /* In most cases, do nothing with a divide by zero. */
5699 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
5700 #ifndef REAL_INFINITY
5701 if (TREE_CODE (arg1) == REAL_CST && real_zerop (arg1))
5704 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
5706 /* (-A) / (-B) -> A / B */
5707 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR)
5708 return fold (build (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
5709 TREE_OPERAND (arg1, 0)));
5711 /* In IEEE floating point, x/1 is not equivalent to x for snans.
5712 However, ANSI says we can drop signals, so we can do this anyway. */
5713 if (real_onep (arg1))
5714 return non_lvalue (convert (type, arg0));
5716 /* If ARG1 is a constant, we can convert this to a multiply by the
5717 reciprocal. This does not have the same rounding properties,
5718 so only do this if -ffast-math. We can actually always safely
5719 do it if ARG1 is a power of two, but it's hard to tell if it is
5720 or not in a portable manner. */
5721 if (TREE_CODE (arg1) == REAL_CST)
5724 && 0 != (tem = const_binop (code, build_real (type, dconst1),
5726 return fold (build (MULT_EXPR, type, arg0, tem));
5727 /* Find the reciprocal if optimizing and the result is exact. */
5731 r = TREE_REAL_CST (arg1);
5732 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
5734 tem = build_real (type, r);
5735 return fold (build (MULT_EXPR, type, arg0, tem));
5741 case TRUNC_DIV_EXPR:
5742 case ROUND_DIV_EXPR:
5743 case FLOOR_DIV_EXPR:
5745 case EXACT_DIV_EXPR:
5746 if (integer_onep (arg1))
5747 return non_lvalue (convert (type, arg0));
5748 if (integer_zerop (arg1))
5751 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
5752 operation, EXACT_DIV_EXPR.
5754 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
5755 At one time others generated faster code, it's not clear if they do
5756 after the last round to changes to the DIV code in expmed.c. */
5757 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
5758 && multiple_of_p (type, arg0, arg1))
5759 return fold (build (EXACT_DIV_EXPR, type, arg0, arg1));
5761 if (TREE_CODE (arg1) == INTEGER_CST
5762 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
5764 return convert (type, tem);
5769 case FLOOR_MOD_EXPR:
5770 case ROUND_MOD_EXPR:
5771 case TRUNC_MOD_EXPR:
5772 if (integer_onep (arg1))
5773 return omit_one_operand (type, integer_zero_node, arg0);
5774 if (integer_zerop (arg1))
5777 if (TREE_CODE (arg1) == INTEGER_CST
5778 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
5780 return convert (type, tem);
5788 if (integer_zerop (arg1))
5789 return non_lvalue (convert (type, arg0));
5790 /* Since negative shift count is not well-defined,
5791 don't try to compute it in the compiler. */
5792 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
5794 /* Rewrite an LROTATE_EXPR by a constant into an
5795 RROTATE_EXPR by a new constant. */
5796 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
5798 TREE_SET_CODE (t, RROTATE_EXPR);
5799 code = RROTATE_EXPR;
5800 TREE_OPERAND (t, 1) = arg1
5803 convert (TREE_TYPE (arg1),
5804 build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type)), 0)),
5806 if (tree_int_cst_sgn (arg1) < 0)
5810 /* If we have a rotate of a bit operation with the rotate count and
5811 the second operand of the bit operation both constant,
5812 permute the two operations. */
5813 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
5814 && (TREE_CODE (arg0) == BIT_AND_EXPR
5815 || TREE_CODE (arg0) == BIT_ANDTC_EXPR
5816 || TREE_CODE (arg0) == BIT_IOR_EXPR
5817 || TREE_CODE (arg0) == BIT_XOR_EXPR)
5818 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
5819 return fold (build (TREE_CODE (arg0), type,
5820 fold (build (code, type,
5821 TREE_OPERAND (arg0, 0), arg1)),
5822 fold (build (code, type,
5823 TREE_OPERAND (arg0, 1), arg1))));
5825 /* Two consecutive rotates adding up to the width of the mode can
5827 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
5828 && TREE_CODE (arg0) == RROTATE_EXPR
5829 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5830 && TREE_INT_CST_HIGH (arg1) == 0
5831 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
5832 && ((TREE_INT_CST_LOW (arg1)
5833 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
5834 == GET_MODE_BITSIZE (TYPE_MODE (type))))
5835 return TREE_OPERAND (arg0, 0);
5840 if (operand_equal_p (arg0, arg1, 0))
5842 if (INTEGRAL_TYPE_P (type)
5843 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), 1))
5844 return omit_one_operand (type, arg1, arg0);
5848 if (operand_equal_p (arg0, arg1, 0))
5850 if (INTEGRAL_TYPE_P (type)
5851 && TYPE_MAX_VALUE (type)
5852 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), 1))
5853 return omit_one_operand (type, arg1, arg0);
5856 case TRUTH_NOT_EXPR:
5857 /* Note that the operand of this must be an int
5858 and its values must be 0 or 1.
5859 ("true" is a fixed value perhaps depending on the language,
5860 but we don't handle values other than 1 correctly yet.) */
5861 tem = invert_truthvalue (arg0);
5862 /* Avoid infinite recursion. */
5863 if (TREE_CODE (tem) == TRUTH_NOT_EXPR)
5865 return convert (type, tem);
5867 case TRUTH_ANDIF_EXPR:
5868 /* Note that the operands of this must be ints
5869 and their values must be 0 or 1.
5870 ("true" is a fixed value perhaps depending on the language.) */
5871 /* If first arg is constant zero, return it. */
5872 if (integer_zerop (arg0))
5874 case TRUTH_AND_EXPR:
5875 /* If either arg is constant true, drop it. */
5876 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
5877 return non_lvalue (arg1);
5878 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
5879 return non_lvalue (arg0);
5880 /* If second arg is constant zero, result is zero, but first arg
5881 must be evaluated. */
5882 if (integer_zerop (arg1))
5883 return omit_one_operand (type, arg1, arg0);
5884 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
5885 case will be handled here. */
5886 if (integer_zerop (arg0))
5887 return omit_one_operand (type, arg0, arg1);
5890 /* We only do these simplifications if we are optimizing. */
5894 /* Check for things like (A || B) && (A || C). We can convert this
5895 to A || (B && C). Note that either operator can be any of the four
5896 truth and/or operations and the transformation will still be
5897 valid. Also note that we only care about order for the
5898 ANDIF and ORIF operators. If B contains side effects, this
5899 might change the truth-value of A. */
5900 if (TREE_CODE (arg0) == TREE_CODE (arg1)
5901 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
5902 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
5903 || TREE_CODE (arg0) == TRUTH_AND_EXPR
5904 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
5905 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
5907 tree a00 = TREE_OPERAND (arg0, 0);
5908 tree a01 = TREE_OPERAND (arg0, 1);
5909 tree a10 = TREE_OPERAND (arg1, 0);
5910 tree a11 = TREE_OPERAND (arg1, 1);
5911 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
5912 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
5913 && (code == TRUTH_AND_EXPR
5914 || code == TRUTH_OR_EXPR));
5916 if (operand_equal_p (a00, a10, 0))
5917 return fold (build (TREE_CODE (arg0), type, a00,
5918 fold (build (code, type, a01, a11))));
5919 else if (commutative && operand_equal_p (a00, a11, 0))
5920 return fold (build (TREE_CODE (arg0), type, a00,
5921 fold (build (code, type, a01, a10))));
5922 else if (commutative && operand_equal_p (a01, a10, 0))
5923 return fold (build (TREE_CODE (arg0), type, a01,
5924 fold (build (code, type, a00, a11))));
5926 /* This case if tricky because we must either have commutative
5927 operators or else A10 must not have side-effects. */
5929 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
5930 && operand_equal_p (a01, a11, 0))
5931 return fold (build (TREE_CODE (arg0), type,
5932 fold (build (code, type, a00, a10)),
5936 /* See if we can build a range comparison. */
5937 if (0 != (tem = fold_range_test (t)))
5940 /* Check for the possibility of merging component references. If our
5941 lhs is another similar operation, try to merge its rhs with our
5942 rhs. Then try to merge our lhs and rhs. */
5943 if (TREE_CODE (arg0) == code
5944 && 0 != (tem = fold_truthop (code, type,
5945 TREE_OPERAND (arg0, 1), arg1)))
5946 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
5948 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
5953 case TRUTH_ORIF_EXPR:
5954 /* Note that the operands of this must be ints
5955 and their values must be 0 or true.
5956 ("true" is a fixed value perhaps depending on the language.) */
5957 /* If first arg is constant true, return it. */
5958 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
5961 /* If either arg is constant zero, drop it. */
5962 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
5963 return non_lvalue (arg1);
5964 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1))
5965 return non_lvalue (arg0);
5966 /* If second arg is constant true, result is true, but we must
5967 evaluate first arg. */
5968 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
5969 return omit_one_operand (type, arg1, arg0);
5970 /* Likewise for first arg, but note this only occurs here for
5972 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
5973 return omit_one_operand (type, arg0, arg1);
5976 case TRUTH_XOR_EXPR:
5977 /* If either arg is constant zero, drop it. */
5978 if (integer_zerop (arg0))
5979 return non_lvalue (arg1);
5980 if (integer_zerop (arg1))
5981 return non_lvalue (arg0);
5982 /* If either arg is constant true, this is a logical inversion. */
5983 if (integer_onep (arg0))
5984 return non_lvalue (invert_truthvalue (arg1));
5985 if (integer_onep (arg1))
5986 return non_lvalue (invert_truthvalue (arg0));
5995 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
5997 /* (-a) CMP (-b) -> b CMP a */
5998 if (TREE_CODE (arg0) == NEGATE_EXPR
5999 && TREE_CODE (arg1) == NEGATE_EXPR)
6000 return fold (build (code, type, TREE_OPERAND (arg1, 0),
6001 TREE_OPERAND (arg0, 0)));
6002 /* (-a) CMP CST -> a swap(CMP) (-CST) */
6003 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == REAL_CST)
6006 (swap_tree_comparison (code), type,
6007 TREE_OPERAND (arg0, 0),
6008 build_real (TREE_TYPE (arg1),
6009 REAL_VALUE_NEGATE (TREE_REAL_CST (arg1)))));
6010 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
6011 /* a CMP (-0) -> a CMP 0 */
6012 if (TREE_CODE (arg1) == REAL_CST
6013 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (arg1)))
6014 return fold (build (code, type, arg0,
6015 build_real (TREE_TYPE (arg1), dconst0)));
6019 /* If one arg is a constant integer, put it last. */
6020 if (TREE_CODE (arg0) == INTEGER_CST
6021 && TREE_CODE (arg1) != INTEGER_CST)
6023 TREE_OPERAND (t, 0) = arg1;
6024 TREE_OPERAND (t, 1) = arg0;
6025 arg0 = TREE_OPERAND (t, 0);
6026 arg1 = TREE_OPERAND (t, 1);
6027 code = swap_tree_comparison (code);
6028 TREE_SET_CODE (t, code);
6031 /* Convert foo++ == CONST into ++foo == CONST + INCR.
6032 First, see if one arg is constant; find the constant arg
6033 and the other one. */
6035 tree constop = 0, varop = NULL_TREE;
6036 int constopnum = -1;
6038 if (TREE_CONSTANT (arg1))
6039 constopnum = 1, constop = arg1, varop = arg0;
6040 if (TREE_CONSTANT (arg0))
6041 constopnum = 0, constop = arg0, varop = arg1;
6043 if (constop && TREE_CODE (varop) == POSTINCREMENT_EXPR)
6045 /* This optimization is invalid for ordered comparisons
6046 if CONST+INCR overflows or if foo+incr might overflow.
6047 This optimization is invalid for floating point due to rounding.
6048 For pointer types we assume overflow doesn't happen. */
6049 if (POINTER_TYPE_P (TREE_TYPE (varop))
6050 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
6051 && (code == EQ_EXPR || code == NE_EXPR)))
6054 = fold (build (PLUS_EXPR, TREE_TYPE (varop),
6055 constop, TREE_OPERAND (varop, 1)));
6056 TREE_SET_CODE (varop, PREINCREMENT_EXPR);
6058 /* If VAROP is a reference to a bitfield, we must mask
6059 the constant by the width of the field. */
6060 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
6061 && DECL_BIT_FIELD(TREE_OPERAND
6062 (TREE_OPERAND (varop, 0), 1)))
6065 = TREE_INT_CST_LOW (DECL_SIZE
6067 (TREE_OPERAND (varop, 0), 1)));
6068 tree mask, unsigned_type;
6070 tree folded_compare;
6072 /* First check whether the comparison would come out
6073 always the same. If we don't do that we would
6074 change the meaning with the masking. */
6075 if (constopnum == 0)
6076 folded_compare = fold (build (code, type, constop,
6077 TREE_OPERAND (varop, 0)));
6079 folded_compare = fold (build (code, type,
6080 TREE_OPERAND (varop, 0),
6082 if (integer_zerop (folded_compare)
6083 || integer_onep (folded_compare))
6084 return omit_one_operand (type, folded_compare, varop);
6086 unsigned_type = type_for_size (size, 1);
6087 precision = TYPE_PRECISION (unsigned_type);
6088 mask = build_int_2 (~0, ~0);
6089 TREE_TYPE (mask) = unsigned_type;
6090 force_fit_type (mask, 0);
6091 mask = const_binop (RSHIFT_EXPR, mask,
6092 size_int (precision - size), 0);
6093 newconst = fold (build (BIT_AND_EXPR,
6094 TREE_TYPE (varop), newconst,
6095 convert (TREE_TYPE (varop),
6100 t = build (code, type, TREE_OPERAND (t, 0),
6101 TREE_OPERAND (t, 1));
6102 TREE_OPERAND (t, constopnum) = newconst;
6106 else if (constop && TREE_CODE (varop) == POSTDECREMENT_EXPR)
6108 if (POINTER_TYPE_P (TREE_TYPE (varop))
6109 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
6110 && (code == EQ_EXPR || code == NE_EXPR)))
6113 = fold (build (MINUS_EXPR, TREE_TYPE (varop),
6114 constop, TREE_OPERAND (varop, 1)));
6115 TREE_SET_CODE (varop, PREDECREMENT_EXPR);
6117 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
6118 && DECL_BIT_FIELD(TREE_OPERAND
6119 (TREE_OPERAND (varop, 0), 1)))
6122 = TREE_INT_CST_LOW (DECL_SIZE
6124 (TREE_OPERAND (varop, 0), 1)));
6125 tree mask, unsigned_type;
6127 tree folded_compare;
6129 if (constopnum == 0)
6130 folded_compare = fold (build (code, type, constop,
6131 TREE_OPERAND (varop, 0)));
6133 folded_compare = fold (build (code, type,
6134 TREE_OPERAND (varop, 0),
6136 if (integer_zerop (folded_compare)
6137 || integer_onep (folded_compare))
6138 return omit_one_operand (type, folded_compare, varop);
6140 unsigned_type = type_for_size (size, 1);
6141 precision = TYPE_PRECISION (unsigned_type);
6142 mask = build_int_2 (~0, ~0);
6143 TREE_TYPE (mask) = TREE_TYPE (varop);
6144 force_fit_type (mask, 0);
6145 mask = const_binop (RSHIFT_EXPR, mask,
6146 size_int (precision - size), 0);
6147 newconst = fold (build (BIT_AND_EXPR,
6148 TREE_TYPE (varop), newconst,
6149 convert (TREE_TYPE (varop),
6154 t = build (code, type, TREE_OPERAND (t, 0),
6155 TREE_OPERAND (t, 1));
6156 TREE_OPERAND (t, constopnum) = newconst;
6162 /* Change X >= CST to X > (CST - 1) if CST is positive. */
6163 if (TREE_CODE (arg1) == INTEGER_CST
6164 && TREE_CODE (arg0) != INTEGER_CST
6165 && tree_int_cst_sgn (arg1) > 0)
6167 switch (TREE_CODE (t))
6171 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6172 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6177 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6178 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6186 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
6187 a MINUS_EXPR of a constant, we can convert it into a comparison with
6188 a revised constant as long as no overflow occurs. */
6189 if ((code == EQ_EXPR || code == NE_EXPR)
6190 && TREE_CODE (arg1) == INTEGER_CST
6191 && (TREE_CODE (arg0) == PLUS_EXPR
6192 || TREE_CODE (arg0) == MINUS_EXPR)
6193 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6194 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
6195 ? MINUS_EXPR : PLUS_EXPR,
6196 arg1, TREE_OPERAND (arg0, 1), 0))
6197 && ! TREE_CONSTANT_OVERFLOW (tem))
6198 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6200 /* Similarly for a NEGATE_EXPR. */
6201 else if ((code == EQ_EXPR || code == NE_EXPR)
6202 && TREE_CODE (arg0) == NEGATE_EXPR
6203 && TREE_CODE (arg1) == INTEGER_CST
6204 && 0 != (tem = negate_expr (arg1))
6205 && TREE_CODE (tem) == INTEGER_CST
6206 && ! TREE_CONSTANT_OVERFLOW (tem))
6207 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6209 /* If we have X - Y == 0, we can convert that to X == Y and similarly
6210 for !=. Don't do this for ordered comparisons due to overflow. */
6211 else if ((code == NE_EXPR || code == EQ_EXPR)
6212 && integer_zerop (arg1) && TREE_CODE (arg0) == MINUS_EXPR)
6213 return fold (build (code, type,
6214 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1)));
6216 /* If we are widening one operand of an integer comparison,
6217 see if the other operand is similarly being widened. Perhaps we
6218 can do the comparison in the narrower type. */
6219 else if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
6220 && TREE_CODE (arg0) == NOP_EXPR
6221 && (tem = get_unwidened (arg0, NULL_TREE)) != arg0
6222 && (t1 = get_unwidened (arg1, TREE_TYPE (tem))) != 0
6223 && (TREE_TYPE (t1) == TREE_TYPE (tem)
6224 || (TREE_CODE (t1) == INTEGER_CST
6225 && int_fits_type_p (t1, TREE_TYPE (tem)))))
6226 return fold (build (code, type, tem, convert (TREE_TYPE (tem), t1)));
6228 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
6229 constant, we can simplify it. */
6230 else if (TREE_CODE (arg1) == INTEGER_CST
6231 && (TREE_CODE (arg0) == MIN_EXPR
6232 || TREE_CODE (arg0) == MAX_EXPR)
6233 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
6234 return optimize_minmax_comparison (t);
6236 /* If we are comparing an ABS_EXPR with a constant, we can
6237 convert all the cases into explicit comparisons, but they may
6238 well not be faster than doing the ABS and one comparison.
6239 But ABS (X) <= C is a range comparison, which becomes a subtraction
6240 and a comparison, and is probably faster. */
6241 else if (code == LE_EXPR && TREE_CODE (arg1) == INTEGER_CST
6242 && TREE_CODE (arg0) == ABS_EXPR
6243 && ! TREE_SIDE_EFFECTS (arg0)
6244 && (0 != (tem = negate_expr (arg1)))
6245 && TREE_CODE (tem) == INTEGER_CST
6246 && ! TREE_CONSTANT_OVERFLOW (tem))
6247 return fold (build (TRUTH_ANDIF_EXPR, type,
6248 build (GE_EXPR, type, TREE_OPERAND (arg0, 0), tem),
6249 build (LE_EXPR, type,
6250 TREE_OPERAND (arg0, 0), arg1)));
6252 /* If this is an EQ or NE comparison with zero and ARG0 is
6253 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
6254 two operations, but the latter can be done in one less insn
6255 on machines that have only two-operand insns or on which a
6256 constant cannot be the first operand. */
6257 if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR)
6258 && TREE_CODE (arg0) == BIT_AND_EXPR)
6260 if (TREE_CODE (TREE_OPERAND (arg0, 0)) == LSHIFT_EXPR
6261 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 0), 0)))
6263 fold (build (code, type,
6264 build (BIT_AND_EXPR, TREE_TYPE (arg0),
6266 TREE_TYPE (TREE_OPERAND (arg0, 0)),
6267 TREE_OPERAND (arg0, 1),
6268 TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)),
6269 convert (TREE_TYPE (arg0),
6272 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
6273 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
6275 fold (build (code, type,
6276 build (BIT_AND_EXPR, TREE_TYPE (arg0),
6278 TREE_TYPE (TREE_OPERAND (arg0, 1)),
6279 TREE_OPERAND (arg0, 0),
6280 TREE_OPERAND (TREE_OPERAND (arg0, 1), 1)),
6281 convert (TREE_TYPE (arg0),
6286 /* If this is an NE or EQ comparison of zero against the result of a
6287 signed MOD operation whose second operand is a power of 2, make
6288 the MOD operation unsigned since it is simpler and equivalent. */
6289 if ((code == NE_EXPR || code == EQ_EXPR)
6290 && integer_zerop (arg1)
6291 && ! TREE_UNSIGNED (TREE_TYPE (arg0))
6292 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
6293 || TREE_CODE (arg0) == CEIL_MOD_EXPR
6294 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
6295 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
6296 && integer_pow2p (TREE_OPERAND (arg0, 1)))
6298 tree newtype = unsigned_type (TREE_TYPE (arg0));
6299 tree newmod = build (TREE_CODE (arg0), newtype,
6300 convert (newtype, TREE_OPERAND (arg0, 0)),
6301 convert (newtype, TREE_OPERAND (arg0, 1)));
6303 return build (code, type, newmod, convert (newtype, arg1));
6306 /* If this is an NE comparison of zero with an AND of one, remove the
6307 comparison since the AND will give the correct value. */
6308 if (code == NE_EXPR && integer_zerop (arg1)
6309 && TREE_CODE (arg0) == BIT_AND_EXPR
6310 && integer_onep (TREE_OPERAND (arg0, 1)))
6311 return convert (type, arg0);
6313 /* If we have (A & C) == C where C is a power of 2, convert this into
6314 (A & C) != 0. Similarly for NE_EXPR. */
6315 if ((code == EQ_EXPR || code == NE_EXPR)
6316 && TREE_CODE (arg0) == BIT_AND_EXPR
6317 && integer_pow2p (TREE_OPERAND (arg0, 1))
6318 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
6319 return build (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
6320 arg0, integer_zero_node);
6322 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
6323 and similarly for >= into !=. */
6324 if ((code == LT_EXPR || code == GE_EXPR)
6325 && TREE_UNSIGNED (TREE_TYPE (arg0))
6326 && TREE_CODE (arg1) == LSHIFT_EXPR
6327 && integer_onep (TREE_OPERAND (arg1, 0)))
6328 return build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
6329 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
6330 TREE_OPERAND (arg1, 1)),
6331 convert (TREE_TYPE (arg0), integer_zero_node));
6333 else if ((code == LT_EXPR || code == GE_EXPR)
6334 && TREE_UNSIGNED (TREE_TYPE (arg0))
6335 && (TREE_CODE (arg1) == NOP_EXPR
6336 || TREE_CODE (arg1) == CONVERT_EXPR)
6337 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
6338 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
6340 build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
6341 convert (TREE_TYPE (arg0),
6342 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
6343 TREE_OPERAND (TREE_OPERAND (arg1, 0), 1))),
6344 convert (TREE_TYPE (arg0), integer_zero_node));
6346 /* Simplify comparison of something with itself. (For IEEE
6347 floating-point, we can only do some of these simplifications.) */
6348 if (operand_equal_p (arg0, arg1, 0))
6355 if (INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
6356 return constant_boolean_node (1, type);
6358 TREE_SET_CODE (t, code);
6362 /* For NE, we can only do this simplification if integer. */
6363 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
6365 /* ... fall through ... */
6368 return constant_boolean_node (0, type);
6374 /* An unsigned comparison against 0 can be simplified. */
6375 if (integer_zerop (arg1)
6376 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
6377 || POINTER_TYPE_P (TREE_TYPE (arg1)))
6378 && TREE_UNSIGNED (TREE_TYPE (arg1)))
6380 switch (TREE_CODE (t))
6384 TREE_SET_CODE (t, NE_EXPR);
6388 TREE_SET_CODE (t, EQ_EXPR);
6391 return omit_one_operand (type,
6392 convert (type, integer_one_node),
6395 return omit_one_operand (type,
6396 convert (type, integer_zero_node),
6403 /* Comparisons with the highest or lowest possible integer of
6404 the specified size will have known values and an unsigned
6405 <= 0x7fffffff can be simplified. */
6407 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1)));
6409 if (TREE_CODE (arg1) == INTEGER_CST
6410 && ! TREE_CONSTANT_OVERFLOW (arg1)
6411 && width <= HOST_BITS_PER_WIDE_INT
6412 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
6413 || POINTER_TYPE_P (TREE_TYPE (arg1))))
6415 if (TREE_INT_CST_HIGH (arg1) == 0
6416 && (TREE_INT_CST_LOW (arg1)
6417 == ((HOST_WIDE_INT) 1 << (width - 1)) - 1)
6418 && ! TREE_UNSIGNED (TREE_TYPE (arg1)))
6419 switch (TREE_CODE (t))
6422 return omit_one_operand (type,
6423 convert (type, integer_zero_node),
6426 TREE_SET_CODE (t, EQ_EXPR);
6430 return omit_one_operand (type,
6431 convert (type, integer_one_node),
6434 TREE_SET_CODE (t, NE_EXPR);
6441 else if (TREE_INT_CST_HIGH (arg1) == -1
6442 && (- TREE_INT_CST_LOW (arg1)
6443 == ((HOST_WIDE_INT) 1 << (width - 1)))
6444 && ! TREE_UNSIGNED (TREE_TYPE (arg1)))
6445 switch (TREE_CODE (t))
6448 return omit_one_operand (type,
6449 convert (type, integer_zero_node),
6452 TREE_SET_CODE (t, EQ_EXPR);
6456 return omit_one_operand (type,
6457 convert (type, integer_one_node),
6460 TREE_SET_CODE (t, NE_EXPR);
6467 else if (TREE_INT_CST_HIGH (arg1) == 0
6468 && (TREE_INT_CST_LOW (arg1)
6469 == ((HOST_WIDE_INT) 1 << (width - 1)) - 1)
6470 && TREE_UNSIGNED (TREE_TYPE (arg1)))
6472 switch (TREE_CODE (t))
6475 return fold (build (GE_EXPR, type,
6476 convert (signed_type (TREE_TYPE (arg0)),
6478 convert (signed_type (TREE_TYPE (arg1)),
6479 integer_zero_node)));
6481 return fold (build (LT_EXPR, type,
6482 convert (signed_type (TREE_TYPE (arg0)),
6484 convert (signed_type (TREE_TYPE (arg1)),
6485 integer_zero_node)));
6493 /* If we are comparing an expression that just has comparisons
6494 of two integer values, arithmetic expressions of those comparisons,
6495 and constants, we can simplify it. There are only three cases
6496 to check: the two values can either be equal, the first can be
6497 greater, or the second can be greater. Fold the expression for
6498 those three values. Since each value must be 0 or 1, we have
6499 eight possibilities, each of which corresponds to the constant 0
6500 or 1 or one of the six possible comparisons.
6502 This handles common cases like (a > b) == 0 but also handles
6503 expressions like ((x > y) - (y > x)) > 0, which supposedly
6504 occur in macroized code. */
6506 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
6508 tree cval1 = 0, cval2 = 0;
6511 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
6512 /* Don't handle degenerate cases here; they should already
6513 have been handled anyway. */
6514 && cval1 != 0 && cval2 != 0
6515 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
6516 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
6517 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
6518 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
6519 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
6520 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
6521 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
6523 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
6524 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
6526 /* We can't just pass T to eval_subst in case cval1 or cval2
6527 was the same as ARG1. */
6530 = fold (build (code, type,
6531 eval_subst (arg0, cval1, maxval, cval2, minval),
6534 = fold (build (code, type,
6535 eval_subst (arg0, cval1, maxval, cval2, maxval),
6538 = fold (build (code, type,
6539 eval_subst (arg0, cval1, minval, cval2, maxval),
6542 /* All three of these results should be 0 or 1. Confirm they
6543 are. Then use those values to select the proper code
6546 if ((integer_zerop (high_result)
6547 || integer_onep (high_result))
6548 && (integer_zerop (equal_result)
6549 || integer_onep (equal_result))
6550 && (integer_zerop (low_result)
6551 || integer_onep (low_result)))
6553 /* Make a 3-bit mask with the high-order bit being the
6554 value for `>', the next for '=', and the low for '<'. */
6555 switch ((integer_onep (high_result) * 4)
6556 + (integer_onep (equal_result) * 2)
6557 + integer_onep (low_result))
6561 return omit_one_operand (type, integer_zero_node, arg0);
6582 return omit_one_operand (type, integer_one_node, arg0);
6585 t = build (code, type, cval1, cval2);
6587 return save_expr (t);
6594 /* If this is a comparison of a field, we may be able to simplify it. */
6595 if ((TREE_CODE (arg0) == COMPONENT_REF
6596 || TREE_CODE (arg0) == BIT_FIELD_REF)
6597 && (code == EQ_EXPR || code == NE_EXPR)
6598 /* Handle the constant case even without -O
6599 to make sure the warnings are given. */
6600 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
6602 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
6606 /* If this is a comparison of complex values and either or both sides
6607 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
6608 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
6609 This may prevent needless evaluations. */
6610 if ((code == EQ_EXPR || code == NE_EXPR)
6611 && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
6612 && (TREE_CODE (arg0) == COMPLEX_EXPR
6613 || TREE_CODE (arg1) == COMPLEX_EXPR
6614 || TREE_CODE (arg0) == COMPLEX_CST
6615 || TREE_CODE (arg1) == COMPLEX_CST))
6617 tree subtype = TREE_TYPE (TREE_TYPE (arg0));
6618 tree real0, imag0, real1, imag1;
6620 arg0 = save_expr (arg0);
6621 arg1 = save_expr (arg1);
6622 real0 = fold (build1 (REALPART_EXPR, subtype, arg0));
6623 imag0 = fold (build1 (IMAGPART_EXPR, subtype, arg0));
6624 real1 = fold (build1 (REALPART_EXPR, subtype, arg1));
6625 imag1 = fold (build1 (IMAGPART_EXPR, subtype, arg1));
6627 return fold (build ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR
6630 fold (build (code, type, real0, real1)),
6631 fold (build (code, type, imag0, imag1))));
6634 /* From here on, the only cases we handle are when the result is
6635 known to be a constant.
6637 To compute GT, swap the arguments and do LT.
6638 To compute GE, do LT and invert the result.
6639 To compute LE, swap the arguments, do LT and invert the result.
6640 To compute NE, do EQ and invert the result.
6642 Therefore, the code below must handle only EQ and LT. */
6644 if (code == LE_EXPR || code == GT_EXPR)
6646 tem = arg0, arg0 = arg1, arg1 = tem;
6647 code = swap_tree_comparison (code);
6650 /* Note that it is safe to invert for real values here because we
6651 will check below in the one case that it matters. */
6655 if (code == NE_EXPR || code == GE_EXPR)
6658 code = invert_tree_comparison (code);
6661 /* Compute a result for LT or EQ if args permit;
6662 otherwise return T. */
6663 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
6665 if (code == EQ_EXPR)
6666 t1 = build_int_2 ((TREE_INT_CST_LOW (arg0)
6667 == TREE_INT_CST_LOW (arg1))
6668 && (TREE_INT_CST_HIGH (arg0)
6669 == TREE_INT_CST_HIGH (arg1)),
6672 t1 = build_int_2 ((TREE_UNSIGNED (TREE_TYPE (arg0))
6673 ? INT_CST_LT_UNSIGNED (arg0, arg1)
6674 : INT_CST_LT (arg0, arg1)),
6678 #if 0 /* This is no longer useful, but breaks some real code. */
6679 /* Assume a nonexplicit constant cannot equal an explicit one,
6680 since such code would be undefined anyway.
6681 Exception: on sysvr4, using #pragma weak,
6682 a label can come out as 0. */
6683 else if (TREE_CODE (arg1) == INTEGER_CST
6684 && !integer_zerop (arg1)
6685 && TREE_CONSTANT (arg0)
6686 && TREE_CODE (arg0) == ADDR_EXPR
6688 t1 = build_int_2 (0, 0);
6690 /* Two real constants can be compared explicitly. */
6691 else if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
6693 /* If either operand is a NaN, the result is false with two
6694 exceptions: First, an NE_EXPR is true on NaNs, but that case
6695 is already handled correctly since we will be inverting the
6696 result for NE_EXPR. Second, if we had inverted a LE_EXPR
6697 or a GE_EXPR into a LT_EXPR, we must return true so that it
6698 will be inverted into false. */
6700 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
6701 || REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
6702 t1 = build_int_2 (invert && code == LT_EXPR, 0);
6704 else if (code == EQ_EXPR)
6705 t1 = build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (arg0),
6706 TREE_REAL_CST (arg1)),
6709 t1 = build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (arg0),
6710 TREE_REAL_CST (arg1)),
6714 if (t1 == NULL_TREE)
6718 TREE_INT_CST_LOW (t1) ^= 1;
6720 TREE_TYPE (t1) = type;
6721 if (TREE_CODE (type) == BOOLEAN_TYPE)
6722 return truthvalue_conversion (t1);
6726 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
6727 so all simple results must be passed through pedantic_non_lvalue. */
6728 if (TREE_CODE (arg0) == INTEGER_CST)
6729 return pedantic_non_lvalue
6730 (TREE_OPERAND (t, (integer_zerop (arg0) ? 2 : 1)));
6731 else if (operand_equal_p (arg1, TREE_OPERAND (expr, 2), 0))
6732 return pedantic_omit_one_operand (type, arg1, arg0);
6734 /* If the second operand is zero, invert the comparison and swap
6735 the second and third operands. Likewise if the second operand
6736 is constant and the third is not or if the third operand is
6737 equivalent to the first operand of the comparison. */
6739 if (integer_zerop (arg1)
6740 || (TREE_CONSTANT (arg1) && ! TREE_CONSTANT (TREE_OPERAND (t, 2)))
6741 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
6742 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
6743 TREE_OPERAND (t, 2),
6744 TREE_OPERAND (arg0, 1))))
6746 /* See if this can be inverted. If it can't, possibly because
6747 it was a floating-point inequality comparison, don't do
6749 tem = invert_truthvalue (arg0);
6751 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
6753 t = build (code, type, tem,
6754 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
6756 /* arg1 should be the first argument of the new T. */
6757 arg1 = TREE_OPERAND (t, 1);
6762 /* If we have A op B ? A : C, we may be able to convert this to a
6763 simpler expression, depending on the operation and the values
6764 of B and C. IEEE floating point prevents this though,
6765 because A or B might be -0.0 or a NaN. */
6767 if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
6768 && (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
6769 || ! FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 0)))
6771 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
6772 arg1, TREE_OPERAND (arg0, 1)))
6774 tree arg2 = TREE_OPERAND (t, 2);
6775 enum tree_code comp_code = TREE_CODE (arg0);
6779 /* If we have A op 0 ? A : -A, this is A, -A, abs (A), or abs (-A),
6780 depending on the comparison operation. */
6781 if ((FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 1)))
6782 ? real_zerop (TREE_OPERAND (arg0, 1))
6783 : integer_zerop (TREE_OPERAND (arg0, 1)))
6784 && TREE_CODE (arg2) == NEGATE_EXPR
6785 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
6789 return pedantic_non_lvalue (negate_expr (arg1));
6791 return pedantic_non_lvalue (convert (type, arg1));
6794 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
6795 arg1 = convert (signed_type (TREE_TYPE (arg1)), arg1);
6796 return pedantic_non_lvalue
6797 (convert (type, fold (build1 (ABS_EXPR,
6798 TREE_TYPE (arg1), arg1))));
6801 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
6802 arg1 = convert (signed_type (TREE_TYPE (arg1)), arg1);
6803 return pedantic_non_lvalue
6804 (negate_expr (convert (type,
6805 fold (build1 (ABS_EXPR,
6812 /* If this is A != 0 ? A : 0, this is simply A. For ==, it is
6815 if (integer_zerop (TREE_OPERAND (arg0, 1)) && integer_zerop (arg2))
6817 if (comp_code == NE_EXPR)
6818 return pedantic_non_lvalue (convert (type, arg1));
6819 else if (comp_code == EQ_EXPR)
6820 return pedantic_non_lvalue (convert (type, integer_zero_node));
6823 /* If this is A op B ? A : B, this is either A, B, min (A, B),
6824 or max (A, B), depending on the operation. */
6826 if (operand_equal_for_comparison_p (TREE_OPERAND (arg0, 1),
6827 arg2, TREE_OPERAND (arg0, 0)))
6829 tree comp_op0 = TREE_OPERAND (arg0, 0);
6830 tree comp_op1 = TREE_OPERAND (arg0, 1);
6831 tree comp_type = TREE_TYPE (comp_op0);
6836 return pedantic_non_lvalue (convert (type, arg2));
6838 return pedantic_non_lvalue (convert (type, arg1));
6841 /* In C++ a ?: expression can be an lvalue, so put the
6842 operand which will be used if they are equal first
6843 so that we can convert this back to the
6844 corresponding COND_EXPR. */
6845 return pedantic_non_lvalue
6846 (convert (type, (fold (build (MIN_EXPR, comp_type,
6847 (comp_code == LE_EXPR
6848 ? comp_op0 : comp_op1),
6849 (comp_code == LE_EXPR
6850 ? comp_op1 : comp_op0))))));
6854 return pedantic_non_lvalue
6855 (convert (type, fold (build (MAX_EXPR, comp_type,
6856 (comp_code == GE_EXPR
6857 ? comp_op0 : comp_op1),
6858 (comp_code == GE_EXPR
6859 ? comp_op1 : comp_op0)))));
6866 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
6867 we might still be able to simplify this. For example,
6868 if C1 is one less or one more than C2, this might have started
6869 out as a MIN or MAX and been transformed by this function.
6870 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
6872 if (INTEGRAL_TYPE_P (type)
6873 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6874 && TREE_CODE (arg2) == INTEGER_CST)
6878 /* We can replace A with C1 in this case. */
6879 arg1 = convert (type, TREE_OPERAND (arg0, 1));
6880 t = build (code, type, TREE_OPERAND (t, 0), arg1,
6881 TREE_OPERAND (t, 2));
6885 /* If C1 is C2 + 1, this is min(A, C2). */
6886 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
6887 && operand_equal_p (TREE_OPERAND (arg0, 1),
6888 const_binop (PLUS_EXPR, arg2,
6889 integer_one_node, 0), 1))
6890 return pedantic_non_lvalue
6891 (fold (build (MIN_EXPR, type, arg1, arg2)));
6895 /* If C1 is C2 - 1, this is min(A, C2). */
6896 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
6897 && operand_equal_p (TREE_OPERAND (arg0, 1),
6898 const_binop (MINUS_EXPR, arg2,
6899 integer_one_node, 0), 1))
6900 return pedantic_non_lvalue
6901 (fold (build (MIN_EXPR, type, arg1, arg2)));
6905 /* If C1 is C2 - 1, this is max(A, C2). */
6906 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
6907 && operand_equal_p (TREE_OPERAND (arg0, 1),
6908 const_binop (MINUS_EXPR, arg2,
6909 integer_one_node, 0), 1))
6910 return pedantic_non_lvalue
6911 (fold (build (MAX_EXPR, type, arg1, arg2)));
6915 /* If C1 is C2 + 1, this is max(A, C2). */
6916 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
6917 && operand_equal_p (TREE_OPERAND (arg0, 1),
6918 const_binop (PLUS_EXPR, arg2,
6919 integer_one_node, 0), 1))
6920 return pedantic_non_lvalue
6921 (fold (build (MAX_EXPR, type, arg1, arg2)));
6930 /* If the second operand is simpler than the third, swap them
6931 since that produces better jump optimization results. */
6932 if ((TREE_CONSTANT (arg1) || TREE_CODE_CLASS (TREE_CODE (arg1)) == 'd'
6933 || TREE_CODE (arg1) == SAVE_EXPR)
6934 && ! (TREE_CONSTANT (TREE_OPERAND (t, 2))
6935 || TREE_CODE_CLASS (TREE_CODE (TREE_OPERAND (t, 2))) == 'd'
6936 || TREE_CODE (TREE_OPERAND (t, 2)) == SAVE_EXPR))
6938 /* See if this can be inverted. If it can't, possibly because
6939 it was a floating-point inequality comparison, don't do
6941 tem = invert_truthvalue (arg0);
6943 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
6945 t = build (code, type, tem,
6946 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
6948 /* arg1 should be the first argument of the new T. */
6949 arg1 = TREE_OPERAND (t, 1);
6954 /* Convert A ? 1 : 0 to simply A. */
6955 if (integer_onep (TREE_OPERAND (t, 1))
6956 && integer_zerop (TREE_OPERAND (t, 2))
6957 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
6958 call to fold will try to move the conversion inside
6959 a COND, which will recurse. In that case, the COND_EXPR
6960 is probably the best choice, so leave it alone. */
6961 && type == TREE_TYPE (arg0))
6962 return pedantic_non_lvalue (arg0);
6964 /* Look for expressions of the form A & 2 ? 2 : 0. The result of this
6965 operation is simply A & 2. */
6967 if (integer_zerop (TREE_OPERAND (t, 2))
6968 && TREE_CODE (arg0) == NE_EXPR
6969 && integer_zerop (TREE_OPERAND (arg0, 1))
6970 && integer_pow2p (arg1)
6971 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
6972 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
6974 return pedantic_non_lvalue (convert (type, TREE_OPERAND (arg0, 0)));
6979 /* When pedantic, a compound expression can be neither an lvalue
6980 nor an integer constant expression. */
6981 if (TREE_SIDE_EFFECTS (arg0) || pedantic)
6983 /* Don't let (0, 0) be null pointer constant. */
6984 if (integer_zerop (arg1))
6985 return build1 (NOP_EXPR, TREE_TYPE (arg1), arg1);
6990 return build_complex (type, arg0, arg1);
6994 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
6996 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
6997 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
6998 TREE_OPERAND (arg0, 1));
6999 else if (TREE_CODE (arg0) == COMPLEX_CST)
7000 return TREE_REALPART (arg0);
7001 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7002 return fold (build (TREE_CODE (arg0), type,
7003 fold (build1 (REALPART_EXPR, type,
7004 TREE_OPERAND (arg0, 0))),
7005 fold (build1 (REALPART_EXPR,
7006 type, TREE_OPERAND (arg0, 1)))));
7010 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7011 return convert (type, integer_zero_node);
7012 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
7013 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
7014 TREE_OPERAND (arg0, 0));
7015 else if (TREE_CODE (arg0) == COMPLEX_CST)
7016 return TREE_IMAGPART (arg0);
7017 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7018 return fold (build (TREE_CODE (arg0), type,
7019 fold (build1 (IMAGPART_EXPR, type,
7020 TREE_OPERAND (arg0, 0))),
7021 fold (build1 (IMAGPART_EXPR, type,
7022 TREE_OPERAND (arg0, 1)))));
7025 /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
7027 case CLEANUP_POINT_EXPR:
7028 if (! has_cleanups (arg0))
7029 return TREE_OPERAND (t, 0);
7032 enum tree_code code0 = TREE_CODE (arg0);
7033 int kind0 = TREE_CODE_CLASS (code0);
7034 tree arg00 = TREE_OPERAND (arg0, 0);
7037 if (kind0 == '1' || code0 == TRUTH_NOT_EXPR)
7038 return fold (build1 (code0, type,
7039 fold (build1 (CLEANUP_POINT_EXPR,
7040 TREE_TYPE (arg00), arg00))));
7042 if (kind0 == '<' || kind0 == '2'
7043 || code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR
7044 || code0 == TRUTH_AND_EXPR || code0 == TRUTH_OR_EXPR
7045 || code0 == TRUTH_XOR_EXPR)
7047 arg01 = TREE_OPERAND (arg0, 1);
7049 if (TREE_CONSTANT (arg00)
7050 || ((code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR)
7051 && ! has_cleanups (arg00)))
7052 return fold (build (code0, type, arg00,
7053 fold (build1 (CLEANUP_POINT_EXPR,
7054 TREE_TYPE (arg01), arg01))));
7056 if (TREE_CONSTANT (arg01))
7057 return fold (build (code0, type,
7058 fold (build1 (CLEANUP_POINT_EXPR,
7059 TREE_TYPE (arg00), arg00)),
7068 } /* switch (code) */
7071 /* Determine if first argument is a multiple of second argument. Return 0 if
7072 it is not, or we cannot easily determined it to be.
7074 An example of the sort of thing we care about (at this point; this routine
7075 could surely be made more general, and expanded to do what the *_DIV_EXPR's
7076 fold cases do now) is discovering that
7078 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7084 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
7086 This code also handles discovering that
7088 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7090 is a multiple of 8 so we don't have to worry about dealing with a
7093 Note that we *look* inside a SAVE_EXPR only to determine how it was
7094 calculated; it is not safe for fold to do much of anything else with the
7095 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
7096 at run time. For example, the latter example above *cannot* be implemented
7097 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
7098 evaluation time of the original SAVE_EXPR is not necessarily the same at
7099 the time the new expression is evaluated. The only optimization of this
7100 sort that would be valid is changing
7102 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
7106 SAVE_EXPR (I) * SAVE_EXPR (J)
7108 (where the same SAVE_EXPR (J) is used in the original and the
7109 transformed version). */
7112 multiple_of_p (type, top, bottom)
7117 if (operand_equal_p (top, bottom, 0))
7120 if (TREE_CODE (type) != INTEGER_TYPE)
7123 switch (TREE_CODE (top))
7126 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
7127 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
7131 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
7132 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
7135 /* Can't handle conversions from non-integral or wider integral type. */
7136 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
7137 || (TYPE_PRECISION (type)
7138 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
7141 /* .. fall through ... */
7144 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
7147 if ((TREE_CODE (bottom) != INTEGER_CST)
7148 || (tree_int_cst_sgn (top) < 0)
7149 || (tree_int_cst_sgn (bottom) < 0))
7151 return integer_zerop (const_binop (TRUNC_MOD_EXPR,