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, 2001 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
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. */
30 /* The entry points in this file are fold, size_int_wide, size_binop
33 fold takes a tree as argument and returns a simplified tree.
35 size_binop takes a tree code for an arithmetic operation
36 and two operands that are trees, and produces a tree for the
37 result, assuming the type comes from `sizetype'.
39 size_int takes an integer value, and creates a tree constant
40 with type from `sizetype'.
42 force_fit_type takes a constant and prior overflow indicator, and
43 forces the value to fit the type. It returns an overflow indicator. */
56 static void encode PARAMS ((HOST_WIDE_INT *,
57 unsigned HOST_WIDE_INT,
59 static void decode PARAMS ((HOST_WIDE_INT *,
60 unsigned HOST_WIDE_INT *,
62 #ifndef REAL_ARITHMETIC
63 static void exact_real_inverse_1 PARAMS ((PTR));
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));
70 static void const_binop_1 PARAMS ((PTR));
71 static tree const_binop PARAMS ((enum tree_code, tree, tree, int));
72 static hashval_t size_htab_hash PARAMS ((const void *));
73 static int size_htab_eq PARAMS ((const void *, const void *));
74 static void fold_convert_1 PARAMS ((PTR));
75 static tree fold_convert PARAMS ((tree, tree));
76 static enum tree_code invert_tree_comparison PARAMS ((enum tree_code));
77 static enum tree_code swap_tree_comparison PARAMS ((enum tree_code));
78 static int truth_value_p PARAMS ((enum tree_code));
79 static int operand_equal_for_comparison_p PARAMS ((tree, tree, tree));
80 static int twoval_comparison_p PARAMS ((tree, tree *, tree *, int *));
81 static tree eval_subst PARAMS ((tree, tree, tree, tree, tree));
82 static tree omit_one_operand PARAMS ((tree, tree, tree));
83 static tree pedantic_omit_one_operand PARAMS ((tree, tree, tree));
84 static tree distribute_bit_expr PARAMS ((enum tree_code, tree, tree, tree));
85 static tree make_bit_field_ref PARAMS ((tree, tree, int, int, int));
86 static tree optimize_bit_field_compare PARAMS ((enum tree_code, tree,
88 static tree decode_field_reference PARAMS ((tree, HOST_WIDE_INT *,
90 enum machine_mode *, int *,
91 int *, tree *, tree *));
92 static int all_ones_mask_p PARAMS ((tree, int));
93 static int simple_operand_p PARAMS ((tree));
94 static tree range_binop PARAMS ((enum tree_code, tree, tree, int,
96 static tree make_range PARAMS ((tree, int *, tree *, tree *));
97 static tree build_range_check PARAMS ((tree, tree, int, tree, tree));
98 static int merge_ranges PARAMS ((int *, tree *, tree *, int, tree, tree,
100 static tree fold_range_test PARAMS ((tree));
101 static tree unextend PARAMS ((tree, int, int, tree));
102 static tree fold_truthop PARAMS ((enum tree_code, tree, tree, tree));
103 static tree optimize_minmax_comparison PARAMS ((tree));
104 static tree extract_muldiv PARAMS ((tree, tree, enum tree_code, tree));
105 static tree strip_compound_expr PARAMS ((tree, tree));
106 static int multiple_of_p PARAMS ((tree, tree, tree));
107 static tree constant_boolean_node PARAMS ((int, tree));
108 static int count_cond PARAMS ((tree, int));
109 static tree fold_binary_op_with_conditional_arg
110 PARAMS ((enum tree_code, tree, tree, tree, int));
113 #define BRANCH_COST 1
116 #if defined(HOST_EBCDIC)
117 /* bit 8 is significant in EBCDIC */
118 #define CHARMASK 0xff
120 #define CHARMASK 0x7f
123 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
124 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
125 and SUM1. Then this yields nonzero if overflow occurred during the
128 Overflow occurs if A and B have the same sign, but A and SUM differ in
129 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
131 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
133 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
134 We do that by representing the two-word integer in 4 words, with only
135 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
136 number. The value of the word is LOWPART + HIGHPART * BASE. */
139 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
140 #define HIGHPART(x) \
141 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
142 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
144 /* Unpack a two-word integer into 4 words.
145 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
146 WORDS points to the array of HOST_WIDE_INTs. */
149 encode (words, low, hi)
150 HOST_WIDE_INT *words;
151 unsigned HOST_WIDE_INT low;
154 words[0] = LOWPART (low);
155 words[1] = HIGHPART (low);
156 words[2] = LOWPART (hi);
157 words[3] = HIGHPART (hi);
160 /* Pack an array of 4 words into a two-word integer.
161 WORDS points to the array of words.
162 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
165 decode (words, low, hi)
166 HOST_WIDE_INT *words;
167 unsigned HOST_WIDE_INT *low;
170 *low = words[0] + words[1] * BASE;
171 *hi = words[2] + words[3] * BASE;
174 /* Make the integer constant T valid for its type by setting to 0 or 1 all
175 the bits in the constant that don't belong in the type.
177 Return 1 if a signed overflow occurs, 0 otherwise. If OVERFLOW is
178 nonzero, a signed overflow has already occurred in calculating T, so
181 Make the real constant T valid for its type by calling CHECK_FLOAT_VALUE,
185 force_fit_type (t, overflow)
189 unsigned HOST_WIDE_INT low;
193 if (TREE_CODE (t) == REAL_CST)
195 #ifdef CHECK_FLOAT_VALUE
196 CHECK_FLOAT_VALUE (TYPE_MODE (TREE_TYPE (t)), TREE_REAL_CST (t),
202 else if (TREE_CODE (t) != INTEGER_CST)
205 low = TREE_INT_CST_LOW (t);
206 high = TREE_INT_CST_HIGH (t);
208 if (POINTER_TYPE_P (TREE_TYPE (t)))
211 prec = TYPE_PRECISION (TREE_TYPE (t));
213 /* First clear all bits that are beyond the type's precision. */
215 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
217 else if (prec > HOST_BITS_PER_WIDE_INT)
218 TREE_INT_CST_HIGH (t)
219 &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
222 TREE_INT_CST_HIGH (t) = 0;
223 if (prec < HOST_BITS_PER_WIDE_INT)
224 TREE_INT_CST_LOW (t) &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
227 /* Unsigned types do not suffer sign extension or overflow unless they
229 if (TREE_UNSIGNED (TREE_TYPE (t))
230 && ! (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
231 && TYPE_IS_SIZETYPE (TREE_TYPE (t))))
234 /* If the value's sign bit is set, extend the sign. */
235 if (prec != 2 * HOST_BITS_PER_WIDE_INT
236 && (prec > HOST_BITS_PER_WIDE_INT
237 ? 0 != (TREE_INT_CST_HIGH (t)
239 << (prec - HOST_BITS_PER_WIDE_INT - 1)))
240 : 0 != (TREE_INT_CST_LOW (t)
241 & ((unsigned HOST_WIDE_INT) 1 << (prec - 1)))))
243 /* Value is negative:
244 set to 1 all the bits that are outside this type's precision. */
245 if (prec > HOST_BITS_PER_WIDE_INT)
246 TREE_INT_CST_HIGH (t)
247 |= ((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
250 TREE_INT_CST_HIGH (t) = -1;
251 if (prec < HOST_BITS_PER_WIDE_INT)
252 TREE_INT_CST_LOW (t) |= ((unsigned HOST_WIDE_INT) (-1) << prec);
256 /* Return nonzero if signed overflow occurred. */
258 ((overflow | (low ^ TREE_INT_CST_LOW (t)) | (high ^ TREE_INT_CST_HIGH (t)))
262 /* Add two doubleword integers with doubleword result.
263 Each argument is given as two `HOST_WIDE_INT' pieces.
264 One argument is L1 and H1; the other, L2 and H2.
265 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
268 add_double (l1, h1, l2, h2, lv, hv)
269 unsigned HOST_WIDE_INT l1, l2;
270 HOST_WIDE_INT h1, h2;
271 unsigned HOST_WIDE_INT *lv;
274 unsigned HOST_WIDE_INT l;
278 h = h1 + h2 + (l < l1);
282 return OVERFLOW_SUM_SIGN (h1, h2, h);
285 /* Negate a doubleword integer with doubleword result.
286 Return nonzero if the operation overflows, assuming it's signed.
287 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
288 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
291 neg_double (l1, h1, lv, hv)
292 unsigned HOST_WIDE_INT l1;
294 unsigned HOST_WIDE_INT *lv;
301 return (*hv & h1) < 0;
311 /* Multiply two doubleword integers with doubleword result.
312 Return nonzero if the operation overflows, assuming it's signed.
313 Each argument is given as two `HOST_WIDE_INT' pieces.
314 One argument is L1 and H1; the other, L2 and H2.
315 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
318 mul_double (l1, h1, l2, h2, lv, hv)
319 unsigned HOST_WIDE_INT l1, l2;
320 HOST_WIDE_INT h1, h2;
321 unsigned HOST_WIDE_INT *lv;
324 HOST_WIDE_INT arg1[4];
325 HOST_WIDE_INT arg2[4];
326 HOST_WIDE_INT prod[4 * 2];
327 unsigned HOST_WIDE_INT carry;
329 unsigned HOST_WIDE_INT toplow, neglow;
330 HOST_WIDE_INT tophigh, neghigh;
332 encode (arg1, l1, h1);
333 encode (arg2, l2, h2);
335 memset ((char *) prod, 0, sizeof prod);
337 for (i = 0; i < 4; i++)
340 for (j = 0; j < 4; j++)
343 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
344 carry += arg1[i] * arg2[j];
345 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
347 prod[k] = LOWPART (carry);
348 carry = HIGHPART (carry);
353 decode (prod, lv, hv); /* This ignores prod[4] through prod[4*2-1] */
355 /* Check for overflow by calculating the top half of the answer in full;
356 it should agree with the low half's sign bit. */
357 decode (prod + 4, &toplow, &tophigh);
360 neg_double (l2, h2, &neglow, &neghigh);
361 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
365 neg_double (l1, h1, &neglow, &neghigh);
366 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
368 return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
371 /* Shift the doubleword integer in L1, H1 left by COUNT places
372 keeping only PREC bits of result.
373 Shift right if COUNT is negative.
374 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
375 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
378 lshift_double (l1, h1, count, prec, lv, hv, arith)
379 unsigned HOST_WIDE_INT l1;
380 HOST_WIDE_INT h1, count;
382 unsigned HOST_WIDE_INT *lv;
388 rshift_double (l1, h1, -count, prec, lv, hv, arith);
392 #ifdef SHIFT_COUNT_TRUNCATED
393 if (SHIFT_COUNT_TRUNCATED)
397 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
399 /* Shifting by the host word size is undefined according to the
400 ANSI standard, so we must handle this as a special case. */
404 else if (count >= HOST_BITS_PER_WIDE_INT)
406 *hv = l1 << (count - HOST_BITS_PER_WIDE_INT);
411 *hv = (((unsigned HOST_WIDE_INT) h1 << count)
412 | (l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
417 /* Shift the doubleword integer in L1, H1 right by COUNT places
418 keeping only PREC bits of result. COUNT must be positive.
419 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
420 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
423 rshift_double (l1, h1, count, prec, lv, hv, arith)
424 unsigned HOST_WIDE_INT l1;
425 HOST_WIDE_INT h1, count;
426 unsigned int prec ATTRIBUTE_UNUSED;
427 unsigned HOST_WIDE_INT *lv;
431 unsigned HOST_WIDE_INT signmask;
434 ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
437 #ifdef SHIFT_COUNT_TRUNCATED
438 if (SHIFT_COUNT_TRUNCATED)
442 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
444 /* Shifting by the host word size is undefined according to the
445 ANSI standard, so we must handle this as a special case. */
449 else if (count >= HOST_BITS_PER_WIDE_INT)
452 *lv = ((signmask << (2 * HOST_BITS_PER_WIDE_INT - count - 1) << 1)
453 | ((unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT)));
458 | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
459 *hv = ((signmask << (HOST_BITS_PER_WIDE_INT - count))
460 | ((unsigned HOST_WIDE_INT) h1 >> count));
464 /* Rotate the doubleword integer in L1, H1 left by COUNT places
465 keeping only PREC bits of result.
466 Rotate right if COUNT is negative.
467 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
470 lrotate_double (l1, h1, count, prec, lv, hv)
471 unsigned HOST_WIDE_INT l1;
472 HOST_WIDE_INT h1, count;
474 unsigned HOST_WIDE_INT *lv;
477 unsigned HOST_WIDE_INT s1l, s2l;
478 HOST_WIDE_INT s1h, s2h;
484 lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
485 rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
490 /* Rotate the doubleword integer in L1, H1 left by COUNT places
491 keeping only PREC bits of result. COUNT must be positive.
492 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
495 rrotate_double (l1, h1, count, prec, lv, hv)
496 unsigned HOST_WIDE_INT l1;
497 HOST_WIDE_INT h1, count;
499 unsigned HOST_WIDE_INT *lv;
502 unsigned HOST_WIDE_INT s1l, s2l;
503 HOST_WIDE_INT s1h, s2h;
509 rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
510 lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
515 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
516 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
517 CODE is a tree code for a kind of division, one of
518 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
520 It controls how the quotient is rounded to an integer.
521 Return nonzero if the operation overflows.
522 UNS nonzero says do unsigned division. */
525 div_and_round_double (code, uns,
526 lnum_orig, hnum_orig, lden_orig, hden_orig,
527 lquo, hquo, lrem, hrem)
530 unsigned HOST_WIDE_INT lnum_orig; /* num == numerator == dividend */
531 HOST_WIDE_INT hnum_orig;
532 unsigned HOST_WIDE_INT lden_orig; /* den == denominator == divisor */
533 HOST_WIDE_INT hden_orig;
534 unsigned HOST_WIDE_INT *lquo, *lrem;
535 HOST_WIDE_INT *hquo, *hrem;
538 HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
539 HOST_WIDE_INT den[4], quo[4];
541 unsigned HOST_WIDE_INT work;
542 unsigned HOST_WIDE_INT carry = 0;
543 unsigned HOST_WIDE_INT lnum = lnum_orig;
544 HOST_WIDE_INT hnum = hnum_orig;
545 unsigned HOST_WIDE_INT lden = lden_orig;
546 HOST_WIDE_INT hden = hden_orig;
549 if (hden == 0 && lden == 0)
550 overflow = 1, lden = 1;
552 /* calculate quotient sign and convert operands to unsigned. */
558 /* (minimum integer) / (-1) is the only overflow case. */
559 if (neg_double (lnum, hnum, &lnum, &hnum)
560 && ((HOST_WIDE_INT) lden & hden) == -1)
566 neg_double (lden, hden, &lden, &hden);
570 if (hnum == 0 && hden == 0)
571 { /* single precision */
573 /* This unsigned division rounds toward zero. */
579 { /* trivial case: dividend < divisor */
580 /* hden != 0 already checked. */
587 memset ((char *) quo, 0, sizeof quo);
589 memset ((char *) num, 0, sizeof num); /* to zero 9th element */
590 memset ((char *) den, 0, sizeof den);
592 encode (num, lnum, hnum);
593 encode (den, lden, hden);
595 /* Special code for when the divisor < BASE. */
596 if (hden == 0 && lden < (unsigned HOST_WIDE_INT) BASE)
598 /* hnum != 0 already checked. */
599 for (i = 4 - 1; i >= 0; i--)
601 work = num[i] + carry * BASE;
602 quo[i] = work / lden;
608 /* Full double precision division,
609 with thanks to Don Knuth's "Seminumerical Algorithms". */
610 int num_hi_sig, den_hi_sig;
611 unsigned HOST_WIDE_INT quo_est, scale;
613 /* Find the highest non-zero divisor digit. */
614 for (i = 4 - 1;; i--)
621 /* Insure that the first digit of the divisor is at least BASE/2.
622 This is required by the quotient digit estimation algorithm. */
624 scale = BASE / (den[den_hi_sig] + 1);
626 { /* scale divisor and dividend */
628 for (i = 0; i <= 4 - 1; i++)
630 work = (num[i] * scale) + carry;
631 num[i] = LOWPART (work);
632 carry = HIGHPART (work);
637 for (i = 0; i <= 4 - 1; i++)
639 work = (den[i] * scale) + carry;
640 den[i] = LOWPART (work);
641 carry = HIGHPART (work);
642 if (den[i] != 0) den_hi_sig = i;
649 for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--)
651 /* Guess the next quotient digit, quo_est, by dividing the first
652 two remaining dividend digits by the high order quotient digit.
653 quo_est is never low and is at most 2 high. */
654 unsigned HOST_WIDE_INT tmp;
656 num_hi_sig = i + den_hi_sig + 1;
657 work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
658 if (num[num_hi_sig] != den[den_hi_sig])
659 quo_est = work / den[den_hi_sig];
663 /* Refine quo_est so it's usually correct, and at most one high. */
664 tmp = work - quo_est * den[den_hi_sig];
666 && (den[den_hi_sig - 1] * quo_est
667 > (tmp * BASE + num[num_hi_sig - 2])))
670 /* Try QUO_EST as the quotient digit, by multiplying the
671 divisor by QUO_EST and subtracting from the remaining dividend.
672 Keep in mind that QUO_EST is the I - 1st digit. */
675 for (j = 0; j <= den_hi_sig; j++)
677 work = quo_est * den[j] + carry;
678 carry = HIGHPART (work);
679 work = num[i + j] - LOWPART (work);
680 num[i + j] = LOWPART (work);
681 carry += HIGHPART (work) != 0;
684 /* If quo_est was high by one, then num[i] went negative and
685 we need to correct things. */
686 if (num[num_hi_sig] < carry)
689 carry = 0; /* add divisor back in */
690 for (j = 0; j <= den_hi_sig; j++)
692 work = num[i + j] + den[j] + carry;
693 carry = HIGHPART (work);
694 num[i + j] = LOWPART (work);
697 num [num_hi_sig] += carry;
700 /* Store the quotient digit. */
705 decode (quo, lquo, hquo);
708 /* if result is negative, make it so. */
710 neg_double (*lquo, *hquo, lquo, hquo);
712 /* compute trial remainder: rem = num - (quo * den) */
713 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
714 neg_double (*lrem, *hrem, lrem, hrem);
715 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
720 case TRUNC_MOD_EXPR: /* round toward zero */
721 case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
725 case FLOOR_MOD_EXPR: /* round toward negative infinity */
726 if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
729 add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
737 case CEIL_MOD_EXPR: /* round toward positive infinity */
738 if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
740 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
748 case ROUND_MOD_EXPR: /* round to closest integer */
750 unsigned HOST_WIDE_INT labs_rem = *lrem;
751 HOST_WIDE_INT habs_rem = *hrem;
752 unsigned HOST_WIDE_INT labs_den = lden, ltwice;
753 HOST_WIDE_INT habs_den = hden, htwice;
755 /* Get absolute values */
757 neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
759 neg_double (lden, hden, &labs_den, &habs_den);
761 /* If (2 * abs (lrem) >= abs (lden)) */
762 mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
763 labs_rem, habs_rem, <wice, &htwice);
765 if (((unsigned HOST_WIDE_INT) habs_den
766 < (unsigned HOST_WIDE_INT) htwice)
767 || (((unsigned HOST_WIDE_INT) habs_den
768 == (unsigned HOST_WIDE_INT) htwice)
769 && (labs_den < ltwice)))
773 add_double (*lquo, *hquo,
774 (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
777 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
789 /* compute true remainder: rem = num - (quo * den) */
790 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
791 neg_double (*lrem, *hrem, lrem, hrem);
792 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
796 #ifndef REAL_ARITHMETIC
797 /* Effectively truncate a real value to represent the nearest possible value
798 in a narrower mode. The result is actually represented in the same data
799 type as the argument, but its value is usually different.
801 A trap may occur during the FP operations and it is the responsibility
802 of the calling function to have a handler established. */
805 real_value_truncate (mode, arg)
806 enum machine_mode mode;
809 return REAL_VALUE_TRUNCATE (mode, arg);
812 #if TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
814 /* Check for infinity in an IEEE double precision number. */
820 /* The IEEE 64-bit double format. */
825 unsigned exponent : 11;
826 unsigned mantissa1 : 20;
827 unsigned mantissa2 : 32;
830 unsigned mantissa2 : 32;
831 unsigned mantissa1 : 20;
832 unsigned exponent : 11;
838 if (u.big_endian.sign == 1)
841 return (u.big_endian.exponent == 2047
842 && u.big_endian.mantissa1 == 0
843 && u.big_endian.mantissa2 == 0);
848 return (u.little_endian.exponent == 2047
849 && u.little_endian.mantissa1 == 0
850 && u.little_endian.mantissa2 == 0);
854 /* Check whether an IEEE double precision number is a NaN. */
860 /* The IEEE 64-bit double format. */
865 unsigned exponent : 11;
866 unsigned mantissa1 : 20;
867 unsigned mantissa2 : 32;
870 unsigned mantissa2 : 32;
871 unsigned mantissa1 : 20;
872 unsigned exponent : 11;
878 if (u.big_endian.sign == 1)
881 return (u.big_endian.exponent == 2047
882 && (u.big_endian.mantissa1 != 0
883 || u.big_endian.mantissa2 != 0));
888 return (u.little_endian.exponent == 2047
889 && (u.little_endian.mantissa1 != 0
890 || u.little_endian.mantissa2 != 0));
894 /* Check for a negative IEEE double precision number. */
900 /* The IEEE 64-bit double format. */
905 unsigned exponent : 11;
906 unsigned mantissa1 : 20;
907 unsigned mantissa2 : 32;
910 unsigned mantissa2 : 32;
911 unsigned mantissa1 : 20;
912 unsigned exponent : 11;
918 if (u.big_endian.sign == 1)
921 return u.big_endian.sign;
926 return u.little_endian.sign;
929 #else /* Target not IEEE */
931 /* Let's assume other float formats don't have infinity.
932 (This can be overridden by redefining REAL_VALUE_ISINF.) */
936 REAL_VALUE_TYPE x ATTRIBUTE_UNUSED;
941 /* Let's assume other float formats don't have NaNs.
942 (This can be overridden by redefining REAL_VALUE_ISNAN.) */
946 REAL_VALUE_TYPE x ATTRIBUTE_UNUSED;
951 /* Let's assume other float formats don't have minus zero.
952 (This can be overridden by redefining REAL_VALUE_NEGATIVE.) */
960 #endif /* Target not IEEE */
962 /* Try to change R into its exact multiplicative inverse in machine mode
963 MODE. Return nonzero function value if successful. */
964 struct exact_real_inverse_args
967 enum machine_mode mode;
972 exact_real_inverse_1 (p)
975 struct exact_real_inverse_args *args =
976 (struct exact_real_inverse_args *) p;
978 enum machine_mode mode = args->mode;
979 REAL_VALUE_TYPE *r = args->r;
987 #ifdef CHECK_FLOAT_VALUE
991 /* Set array index to the less significant bits in the unions, depending
992 on the endian-ness of the host doubles. */
993 #if HOST_FLOAT_FORMAT == VAX_FLOAT_FORMAT \
994 || HOST_FLOAT_FORMAT == IBM_FLOAT_FORMAT
997 # define K (2 * HOST_FLOAT_WORDS_BIG_ENDIAN)
1000 /* Domain check the argument. */
1005 #ifdef REAL_INFINITY
1006 if (REAL_VALUE_ISINF (x.d) || REAL_VALUE_ISNAN (x.d))
1010 /* Compute the reciprocal and check for numerical exactness.
1011 It is unnecessary to check all the significand bits to determine
1012 whether X is a power of 2. If X is not, then it is impossible for
1013 the bottom half significand of both X and 1/X to be all zero bits.
1014 Hence we ignore the data structure of the top half and examine only
1015 the low order bits of the two significands. */
1017 if (x.i[K] != 0 || x.i[K + 1] != 0 || t.i[K] != 0 || t.i[K + 1] != 0)
1020 /* Truncate to the required mode and range-check the result. */
1021 y.d = REAL_VALUE_TRUNCATE (mode, t.d);
1022 #ifdef CHECK_FLOAT_VALUE
1024 if (CHECK_FLOAT_VALUE (mode, y.d, i))
1028 /* Fail if truncation changed the value. */
1029 if (y.d != t.d || y.d == 0.0)
1032 #ifdef REAL_INFINITY
1033 if (REAL_VALUE_ISINF (y.d) || REAL_VALUE_ISNAN (y.d))
1037 /* Output the reciprocal and return success flag. */
1051 exact_real_inverse (mode, r)
1052 enum machine_mode mode;
1055 struct exact_real_inverse_args args;
1057 /* Disable if insufficient information on the data structure. */
1058 #if HOST_FLOAT_FORMAT == UNKNOWN_FLOAT_FORMAT
1062 /* Usually disable if bounds checks are not reliable. */
1063 if ((HOST_FLOAT_FORMAT != TARGET_FLOAT_FORMAT) && !flag_pretend_float)
1069 if (do_float_handler (exact_real_inverse_1, (PTR) &args))
1070 return args.success;
1074 /* Convert C99 hexadecimal floating point string constant S. Return
1075 real value type in mode MODE. This function uses the host computer's
1076 floating point arithmetic when there is no REAL_ARITHMETIC. */
1079 real_hex_to_f (s, mode)
1081 enum machine_mode mode;
1085 unsigned HOST_WIDE_INT low, high;
1086 int shcount, nrmcount, k;
1087 int sign, expsign, isfloat;
1088 int lost = 0;/* Nonzero low order bits shifted out and discarded. */
1089 int frexpon = 0; /* Bits after the decimal point. */
1090 int expon = 0; /* Value of exponent. */
1091 int decpt = 0; /* How many decimal points. */
1092 int gotp = 0; /* How many P's. */
1099 while (*p == ' ' || *p == '\t')
1102 /* Sign, if any, comes first. */
1110 /* The string is supposed to start with 0x or 0X . */
1114 if (*p == 'x' || *p == 'X')
1128 while ((c = *p) != '\0')
1133 if (k >= 'a' && k <= 'f')
1140 if ((high & 0xf0000000) == 0)
1142 high = (high << 4) + ((low >> 28) & 15);
1143 low = (low << 4) + k;
1150 /* Record nonzero lost bits. */
1163 else if (c == 'p' || c == 'P')
1167 /* Sign of exponent. */
1174 /* Value of exponent.
1175 The exponent field is a decimal integer. */
1176 while (ISDIGIT (*p))
1178 k = (*p++ & CHARMASK) - '0';
1179 expon = 10 * expon + k;
1183 /* F suffix is ambiguous in the significand part
1184 so it must appear after the decimal exponent field. */
1185 if (*p == 'f' || *p == 'F')
1193 else if (c == 'l' || c == 'L')
1202 /* Abort if last character read was not legitimate. */
1204 if ((c != '\0' && c != ' ' && c != '\n' && c != '\r') || (decpt > 1))
1207 /* There must be either one decimal point or one p. */
1208 if (decpt == 0 && gotp == 0)
1212 if (high == 0 && low == 0)
1224 /* Leave a high guard bit for carry-out. */
1225 if ((high & 0x80000000) != 0)
1228 low = (low >> 1) | (high << 31);
1233 if ((high & 0xffff8000) == 0)
1235 high = (high << 16) + ((low >> 16) & 0xffff);
1240 while ((high & 0xc0000000) == 0)
1242 high = (high << 1) + ((low >> 31) & 1);
1247 if (isfloat || GET_MODE_SIZE (mode) == UNITS_PER_WORD)
1249 /* Keep 24 bits precision, bits 0x7fffff80.
1250 Rounding bit is 0x40. */
1251 lost = lost | low | (high & 0x3f);
1255 if ((high & 0x80) || lost)
1262 /* We need real.c to do long double formats, so here default
1263 to double precision. */
1264 #if HOST_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
1266 Keep 53 bits precision, bits 0x7fffffff fffffc00.
1267 Rounding bit is low word 0x200. */
1268 lost = lost | (low & 0x1ff);
1271 if ((low & 0x400) || lost)
1273 low = (low + 0x200) & 0xfffffc00;
1280 /* Assume it's a VAX with 56-bit significand,
1281 bits 0x7fffffff ffffff80. */
1282 lost = lost | (low & 0x7f);
1285 if ((low & 0x80) || lost)
1287 low = (low + 0x40) & 0xffffff80;
1297 ip = REAL_VALUE_LDEXP (ip, 32) + (double) low;
1298 /* Apply shifts and exponent value as power of 2. */
1299 ip = REAL_VALUE_LDEXP (ip, expon - (nrmcount + frexpon));
1306 #endif /* no REAL_ARITHMETIC */
1308 /* Given T, an expression, return the negation of T. Allow for T to be
1309 null, in which case return null. */
1321 type = TREE_TYPE (t);
1322 STRIP_SIGN_NOPS (t);
1324 switch (TREE_CODE (t))
1328 if (! TREE_UNSIGNED (type)
1329 && 0 != (tem = fold (build1 (NEGATE_EXPR, type, t)))
1330 && ! TREE_OVERFLOW (tem))
1335 return convert (type, TREE_OPERAND (t, 0));
1338 /* - (A - B) -> B - A */
1339 if (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
1340 return convert (type,
1341 fold (build (MINUS_EXPR, TREE_TYPE (t),
1342 TREE_OPERAND (t, 1),
1343 TREE_OPERAND (t, 0))));
1350 return convert (type, build1 (NEGATE_EXPR, TREE_TYPE (t), t));
1353 /* Split a tree IN into a constant, literal and variable parts that could be
1354 combined with CODE to make IN. "constant" means an expression with
1355 TREE_CONSTANT but that isn't an actual constant. CODE must be a
1356 commutative arithmetic operation. Store the constant part into *CONP,
1357 the literal in &LITP and return the variable part. If a part isn't
1358 present, set it to null. If the tree does not decompose in this way,
1359 return the entire tree as the variable part and the other parts as null.
1361 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
1362 case, we negate an operand that was subtracted. If NEGATE_P is true, we
1363 are negating all of IN.
1365 If IN is itself a literal or constant, return it as appropriate.
1367 Note that we do not guarantee that any of the three values will be the
1368 same type as IN, but they will have the same signedness and mode. */
1371 split_tree (in, code, conp, litp, negate_p)
1373 enum tree_code code;
1382 /* Strip any conversions that don't change the machine mode or signedness. */
1383 STRIP_SIGN_NOPS (in);
1385 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST)
1387 else if (TREE_CODE (in) == code
1388 || (! FLOAT_TYPE_P (TREE_TYPE (in))
1389 /* We can associate addition and subtraction together (even
1390 though the C standard doesn't say so) for integers because
1391 the value is not affected. For reals, the value might be
1392 affected, so we can't. */
1393 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
1394 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
1396 tree op0 = TREE_OPERAND (in, 0);
1397 tree op1 = TREE_OPERAND (in, 1);
1398 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
1399 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
1401 /* First see if either of the operands is a literal, then a constant. */
1402 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
1403 *litp = op0, op0 = 0;
1404 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST)
1405 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
1407 if (op0 != 0 && TREE_CONSTANT (op0))
1408 *conp = op0, op0 = 0;
1409 else if (op1 != 0 && TREE_CONSTANT (op1))
1410 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
1412 /* If we haven't dealt with either operand, this is not a case we can
1413 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1414 if (op0 != 0 && op1 != 0)
1419 var = op1, neg_var_p = neg1_p;
1421 /* Now do any needed negations. */
1422 if (neg_litp_p) *litp = negate_expr (*litp);
1423 if (neg_conp_p) *conp = negate_expr (*conp);
1424 if (neg_var_p) var = negate_expr (var);
1426 else if (TREE_CONSTANT (in))
1433 var = negate_expr (var);
1434 *conp = negate_expr (*conp);
1435 *litp = negate_expr (*litp);
1441 /* Re-associate trees split by the above function. T1 and T2 are either
1442 expressions to associate or null. Return the new expression, if any. If
1443 we build an operation, do it in TYPE and with CODE, except if CODE is a
1444 MINUS_EXPR, in which case we use PLUS_EXPR since split_tree will already
1445 have taken care of the negations. */
1448 associate_trees (t1, t2, code, type)
1450 enum tree_code code;
1458 if (code == MINUS_EXPR)
1461 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1462 try to fold this since we will have infinite recursion. But do
1463 deal with any NEGATE_EXPRs. */
1464 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
1465 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1467 if (TREE_CODE (t1) == NEGATE_EXPR)
1468 return build (MINUS_EXPR, type, convert (type, t2),
1469 convert (type, TREE_OPERAND (t1, 0)));
1470 else if (TREE_CODE (t2) == NEGATE_EXPR)
1471 return build (MINUS_EXPR, type, convert (type, t1),
1472 convert (type, TREE_OPERAND (t2, 0)));
1474 return build (code, type, convert (type, t1), convert (type, t2));
1477 return fold (build (code, type, convert (type, t1), convert (type, t2)));
1480 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1481 to produce a new constant.
1483 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1486 int_const_binop (code, arg1, arg2, notrunc)
1487 enum tree_code code;
1491 unsigned HOST_WIDE_INT int1l, int2l;
1492 HOST_WIDE_INT int1h, int2h;
1493 unsigned HOST_WIDE_INT low;
1495 unsigned HOST_WIDE_INT garbagel;
1496 HOST_WIDE_INT garbageh;
1498 tree type = TREE_TYPE (arg1);
1499 int uns = TREE_UNSIGNED (type);
1501 = (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type));
1503 int no_overflow = 0;
1505 int1l = TREE_INT_CST_LOW (arg1);
1506 int1h = TREE_INT_CST_HIGH (arg1);
1507 int2l = TREE_INT_CST_LOW (arg2);
1508 int2h = TREE_INT_CST_HIGH (arg2);
1513 low = int1l | int2l, hi = int1h | int2h;
1517 low = int1l ^ int2l, hi = int1h ^ int2h;
1521 low = int1l & int2l, hi = int1h & int2h;
1524 case BIT_ANDTC_EXPR:
1525 low = int1l & ~int2l, hi = int1h & ~int2h;
1531 /* It's unclear from the C standard whether shifts can overflow.
1532 The following code ignores overflow; perhaps a C standard
1533 interpretation ruling is needed. */
1534 lshift_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1542 lrotate_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1547 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1551 neg_double (int2l, int2h, &low, &hi);
1552 add_double (int1l, int1h, low, hi, &low, &hi);
1553 overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
1557 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1560 case TRUNC_DIV_EXPR:
1561 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1562 case EXACT_DIV_EXPR:
1563 /* This is a shortcut for a common special case. */
1564 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1565 && ! TREE_CONSTANT_OVERFLOW (arg1)
1566 && ! TREE_CONSTANT_OVERFLOW (arg2)
1567 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1569 if (code == CEIL_DIV_EXPR)
1572 low = int1l / int2l, hi = 0;
1576 /* ... fall through ... */
1578 case ROUND_DIV_EXPR:
1579 if (int2h == 0 && int2l == 1)
1581 low = int1l, hi = int1h;
1584 if (int1l == int2l && int1h == int2h
1585 && ! (int1l == 0 && int1h == 0))
1590 overflow = div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
1591 &low, &hi, &garbagel, &garbageh);
1594 case TRUNC_MOD_EXPR:
1595 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1596 /* This is a shortcut for a common special case. */
1597 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1598 && ! TREE_CONSTANT_OVERFLOW (arg1)
1599 && ! TREE_CONSTANT_OVERFLOW (arg2)
1600 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1602 if (code == CEIL_MOD_EXPR)
1604 low = int1l % int2l, hi = 0;
1608 /* ... fall through ... */
1610 case ROUND_MOD_EXPR:
1611 overflow = div_and_round_double (code, uns,
1612 int1l, int1h, int2l, int2h,
1613 &garbagel, &garbageh, &low, &hi);
1619 low = (((unsigned HOST_WIDE_INT) int1h
1620 < (unsigned HOST_WIDE_INT) int2h)
1621 || (((unsigned HOST_WIDE_INT) int1h
1622 == (unsigned HOST_WIDE_INT) int2h)
1625 low = (int1h < int2h
1626 || (int1h == int2h && int1l < int2l));
1628 if (low == (code == MIN_EXPR))
1629 low = int1l, hi = int1h;
1631 low = int2l, hi = int2h;
1638 /* If this is for a sizetype, can be represented as one (signed)
1639 HOST_WIDE_INT word, and doesn't overflow, use size_int since it caches
1642 && ((hi == 0 && (HOST_WIDE_INT) low >= 0)
1643 || (hi == -1 && (HOST_WIDE_INT) low < 0))
1644 && overflow == 0 && ! TREE_OVERFLOW (arg1) && ! TREE_OVERFLOW (arg2))
1645 return size_int_type_wide (low, type);
1648 t = build_int_2 (low, hi);
1649 TREE_TYPE (t) = TREE_TYPE (arg1);
1654 ? (!uns || is_sizetype) && overflow
1655 : (force_fit_type (t, (!uns || is_sizetype) && overflow)
1657 | TREE_OVERFLOW (arg1)
1658 | TREE_OVERFLOW (arg2));
1660 /* If we're doing a size calculation, unsigned arithmetic does overflow.
1661 So check if force_fit_type truncated the value. */
1663 && ! TREE_OVERFLOW (t)
1664 && (TREE_INT_CST_HIGH (t) != hi
1665 || TREE_INT_CST_LOW (t) != low))
1666 TREE_OVERFLOW (t) = 1;
1668 TREE_CONSTANT_OVERFLOW (t) = (TREE_OVERFLOW (t)
1669 | TREE_CONSTANT_OVERFLOW (arg1)
1670 | TREE_CONSTANT_OVERFLOW (arg2));
1674 /* Define input and output argument for const_binop_1. */
1677 enum tree_code code; /* Input: tree code for operation. */
1678 tree type; /* Input: tree type for operation. */
1679 REAL_VALUE_TYPE d1, d2; /* Input: floating point operands. */
1680 tree t; /* Output: constant for result. */
1683 /* Do the real arithmetic for const_binop while protected by a
1684 float overflow handler. */
1687 const_binop_1 (data)
1690 struct cb_args *args = (struct cb_args *) data;
1691 REAL_VALUE_TYPE value;
1693 #ifdef REAL_ARITHMETIC
1694 REAL_ARITHMETIC (value, args->code, args->d1, args->d2);
1699 value = args->d1 + args->d2;
1703 value = args->d1 - args->d2;
1707 value = args->d1 * args->d2;
1711 #ifndef REAL_INFINITY
1716 value = args->d1 / args->d2;
1720 value = MIN (args->d1, args->d2);
1724 value = MAX (args->d1, args->d2);
1730 #endif /* no REAL_ARITHMETIC */
1733 = build_real (args->type,
1734 real_value_truncate (TYPE_MODE (args->type), value));
1737 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1738 constant. We assume ARG1 and ARG2 have the same data type, or at least
1739 are the same kind of constant and the same machine mode.
1741 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1744 const_binop (code, arg1, arg2, notrunc)
1745 enum tree_code code;
1752 if (TREE_CODE (arg1) == INTEGER_CST)
1753 return int_const_binop (code, arg1, arg2, notrunc);
1755 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1756 if (TREE_CODE (arg1) == REAL_CST)
1762 struct cb_args args;
1764 d1 = TREE_REAL_CST (arg1);
1765 d2 = TREE_REAL_CST (arg2);
1767 /* If either operand is a NaN, just return it. Otherwise, set up
1768 for floating-point trap; we return an overflow. */
1769 if (REAL_VALUE_ISNAN (d1))
1771 else if (REAL_VALUE_ISNAN (d2))
1774 /* Setup input for const_binop_1() */
1775 args.type = TREE_TYPE (arg1);
1780 if (do_float_handler (const_binop_1, (PTR) &args))
1781 /* Receive output from const_binop_1. */
1785 /* We got an exception from const_binop_1. */
1786 t = copy_node (arg1);
1791 = (force_fit_type (t, overflow)
1792 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
1793 TREE_CONSTANT_OVERFLOW (t)
1795 | TREE_CONSTANT_OVERFLOW (arg1)
1796 | TREE_CONSTANT_OVERFLOW (arg2);
1799 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
1800 if (TREE_CODE (arg1) == COMPLEX_CST)
1802 tree type = TREE_TYPE (arg1);
1803 tree r1 = TREE_REALPART (arg1);
1804 tree i1 = TREE_IMAGPART (arg1);
1805 tree r2 = TREE_REALPART (arg2);
1806 tree i2 = TREE_IMAGPART (arg2);
1812 t = build_complex (type,
1813 const_binop (PLUS_EXPR, r1, r2, notrunc),
1814 const_binop (PLUS_EXPR, i1, i2, notrunc));
1818 t = build_complex (type,
1819 const_binop (MINUS_EXPR, r1, r2, notrunc),
1820 const_binop (MINUS_EXPR, i1, i2, notrunc));
1824 t = build_complex (type,
1825 const_binop (MINUS_EXPR,
1826 const_binop (MULT_EXPR,
1828 const_binop (MULT_EXPR,
1831 const_binop (PLUS_EXPR,
1832 const_binop (MULT_EXPR,
1834 const_binop (MULT_EXPR,
1842 = const_binop (PLUS_EXPR,
1843 const_binop (MULT_EXPR, r2, r2, notrunc),
1844 const_binop (MULT_EXPR, i2, i2, notrunc),
1847 t = build_complex (type,
1849 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1850 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1851 const_binop (PLUS_EXPR,
1852 const_binop (MULT_EXPR, r1, r2,
1854 const_binop (MULT_EXPR, i1, i2,
1857 magsquared, notrunc),
1859 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1860 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1861 const_binop (MINUS_EXPR,
1862 const_binop (MULT_EXPR, i1, r2,
1864 const_binop (MULT_EXPR, r1, i2,
1867 magsquared, notrunc));
1879 /* These are the hash table functions for the hash table of INTEGER_CST
1880 nodes of a sizetype. */
1882 /* Return the hash code code X, an INTEGER_CST. */
1890 return (TREE_INT_CST_HIGH (t) ^ TREE_INT_CST_LOW (t)
1891 ^ (hashval_t) ((long) TREE_TYPE (t) >> 3)
1892 ^ (TREE_OVERFLOW (t) << 20));
1895 /* Return non-zero if the value represented by *X (an INTEGER_CST tree node)
1896 is the same as that given by *Y, which is the same. */
1906 return (TREE_INT_CST_HIGH (xt) == TREE_INT_CST_HIGH (yt)
1907 && TREE_INT_CST_LOW (xt) == TREE_INT_CST_LOW (yt)
1908 && TREE_TYPE (xt) == TREE_TYPE (yt)
1909 && TREE_OVERFLOW (xt) == TREE_OVERFLOW (yt));
1912 /* Return an INTEGER_CST with value whose low-order HOST_BITS_PER_WIDE_INT
1913 bits are given by NUMBER and of the sizetype represented by KIND. */
1916 size_int_wide (number, kind)
1917 HOST_WIDE_INT number;
1918 enum size_type_kind kind;
1920 return size_int_type_wide (number, sizetype_tab[(int) kind]);
1923 /* Likewise, but the desired type is specified explicitly. */
1926 size_int_type_wide (number, type)
1927 HOST_WIDE_INT number;
1930 static htab_t size_htab = 0;
1931 static tree new_const = 0;
1936 size_htab = htab_create (1024, size_htab_hash, size_htab_eq, NULL);
1937 ggc_add_deletable_htab (size_htab, NULL, NULL);
1938 new_const = make_node (INTEGER_CST);
1939 ggc_add_tree_root (&new_const, 1);
1942 /* Adjust NEW_CONST to be the constant we want. If it's already in the
1943 hash table, we return the value from the hash table. Otherwise, we
1944 place that in the hash table and make a new node for the next time. */
1945 TREE_INT_CST_LOW (new_const) = number;
1946 TREE_INT_CST_HIGH (new_const) = number < 0 ? -1 : 0;
1947 TREE_TYPE (new_const) = type;
1948 TREE_OVERFLOW (new_const) = TREE_CONSTANT_OVERFLOW (new_const)
1949 = force_fit_type (new_const, 0);
1951 slot = htab_find_slot (size_htab, new_const, INSERT);
1956 *slot = (PTR) new_const;
1957 new_const = make_node (INTEGER_CST);
1961 return (tree) *slot;
1964 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1965 is a tree code. The type of the result is taken from the operands.
1966 Both must be the same type integer type and it must be a size type.
1967 If the operands are constant, so is the result. */
1970 size_binop (code, arg0, arg1)
1971 enum tree_code code;
1974 tree type = TREE_TYPE (arg0);
1976 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1977 || type != TREE_TYPE (arg1))
1980 /* Handle the special case of two integer constants faster. */
1981 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1983 /* And some specific cases even faster than that. */
1984 if (code == PLUS_EXPR && integer_zerop (arg0))
1986 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1987 && integer_zerop (arg1))
1989 else if (code == MULT_EXPR && integer_onep (arg0))
1992 /* Handle general case of two integer constants. */
1993 return int_const_binop (code, arg0, arg1, 0);
1996 if (arg0 == error_mark_node || arg1 == error_mark_node)
1997 return error_mark_node;
1999 return fold (build (code, type, arg0, arg1));
2002 /* Given two values, either both of sizetype or both of bitsizetype,
2003 compute the difference between the two values. Return the value
2004 in signed type corresponding to the type of the operands. */
2007 size_diffop (arg0, arg1)
2010 tree type = TREE_TYPE (arg0);
2013 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
2014 || type != TREE_TYPE (arg1))
2017 /* If the type is already signed, just do the simple thing. */
2018 if (! TREE_UNSIGNED (type))
2019 return size_binop (MINUS_EXPR, arg0, arg1);
2021 ctype = (type == bitsizetype || type == ubitsizetype
2022 ? sbitsizetype : ssizetype);
2024 /* If either operand is not a constant, do the conversions to the signed
2025 type and subtract. The hardware will do the right thing with any
2026 overflow in the subtraction. */
2027 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
2028 return size_binop (MINUS_EXPR, convert (ctype, arg0),
2029 convert (ctype, arg1));
2031 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
2032 Otherwise, subtract the other way, convert to CTYPE (we know that can't
2033 overflow) and negate (which can't either). Special-case a result
2034 of zero while we're here. */
2035 if (tree_int_cst_equal (arg0, arg1))
2036 return convert (ctype, integer_zero_node);
2037 else if (tree_int_cst_lt (arg1, arg0))
2038 return convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
2040 return size_binop (MINUS_EXPR, convert (ctype, integer_zero_node),
2041 convert (ctype, size_binop (MINUS_EXPR, arg1, arg0)));
2044 /* This structure is used to communicate arguments to fold_convert_1. */
2047 tree arg1; /* Input: value to convert. */
2048 tree type; /* Input: type to convert value to. */
2049 tree t; /* Ouput: result of conversion. */
2052 /* Function to convert floating-point constants, protected by floating
2053 point exception handler. */
2056 fold_convert_1 (data)
2059 struct fc_args *args = (struct fc_args *) data;
2061 args->t = build_real (args->type,
2062 real_value_truncate (TYPE_MODE (args->type),
2063 TREE_REAL_CST (args->arg1)));
2066 /* Given T, a tree representing type conversion of ARG1, a constant,
2067 return a constant tree representing the result of conversion. */
2070 fold_convert (t, arg1)
2074 tree type = TREE_TYPE (t);
2077 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
2079 if (TREE_CODE (arg1) == INTEGER_CST)
2081 /* If we would build a constant wider than GCC supports,
2082 leave the conversion unfolded. */
2083 if (TYPE_PRECISION (type) > 2 * HOST_BITS_PER_WIDE_INT)
2086 /* If we are trying to make a sizetype for a small integer, use
2087 size_int to pick up cached types to reduce duplicate nodes. */
2088 if (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type)
2089 && !TREE_CONSTANT_OVERFLOW (arg1)
2090 && compare_tree_int (arg1, 10000) < 0)
2091 return size_int_type_wide (TREE_INT_CST_LOW (arg1), type);
2093 /* Given an integer constant, make new constant with new type,
2094 appropriately sign-extended or truncated. */
2095 t = build_int_2 (TREE_INT_CST_LOW (arg1),
2096 TREE_INT_CST_HIGH (arg1));
2097 TREE_TYPE (t) = type;
2098 /* Indicate an overflow if (1) ARG1 already overflowed,
2099 or (2) force_fit_type indicates an overflow.
2100 Tell force_fit_type that an overflow has already occurred
2101 if ARG1 is a too-large unsigned value and T is signed.
2102 But don't indicate an overflow if converting a pointer. */
2104 = ((force_fit_type (t,
2105 (TREE_INT_CST_HIGH (arg1) < 0
2106 && (TREE_UNSIGNED (type)
2107 < TREE_UNSIGNED (TREE_TYPE (arg1)))))
2108 && ! POINTER_TYPE_P (TREE_TYPE (arg1)))
2109 || TREE_OVERFLOW (arg1));
2110 TREE_CONSTANT_OVERFLOW (t)
2111 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
2113 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
2114 else if (TREE_CODE (arg1) == REAL_CST)
2116 /* Don't initialize these, use assignments.
2117 Initialized local aggregates don't work on old compilers. */
2121 tree type1 = TREE_TYPE (arg1);
2124 x = TREE_REAL_CST (arg1);
2125 l = real_value_from_int_cst (type1, TYPE_MIN_VALUE (type));
2127 no_upper_bound = (TYPE_MAX_VALUE (type) == NULL);
2128 if (!no_upper_bound)
2129 u = real_value_from_int_cst (type1, TYPE_MAX_VALUE (type));
2131 /* See if X will be in range after truncation towards 0.
2132 To compensate for truncation, move the bounds away from 0,
2133 but reject if X exactly equals the adjusted bounds. */
2134 #ifdef REAL_ARITHMETIC
2135 REAL_ARITHMETIC (l, MINUS_EXPR, l, dconst1);
2136 if (!no_upper_bound)
2137 REAL_ARITHMETIC (u, PLUS_EXPR, u, dconst1);
2140 if (!no_upper_bound)
2143 /* If X is a NaN, use zero instead and show we have an overflow.
2144 Otherwise, range check. */
2145 if (REAL_VALUE_ISNAN (x))
2146 overflow = 1, x = dconst0;
2147 else if (! (REAL_VALUES_LESS (l, x)
2149 && REAL_VALUES_LESS (x, u)))
2152 #ifndef REAL_ARITHMETIC
2154 HOST_WIDE_INT low, high;
2155 HOST_WIDE_INT half_word
2156 = (HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2);
2161 high = (HOST_WIDE_INT) (x / half_word / half_word);
2162 x -= (REAL_VALUE_TYPE) high * half_word * half_word;
2163 if (x >= (REAL_VALUE_TYPE) half_word * half_word / 2)
2165 low = x - (REAL_VALUE_TYPE) half_word * half_word / 2;
2166 low |= (HOST_WIDE_INT) -1 << (HOST_BITS_PER_WIDE_INT - 1);
2169 low = (HOST_WIDE_INT) x;
2170 if (TREE_REAL_CST (arg1) < 0)
2171 neg_double (low, high, &low, &high);
2172 t = build_int_2 (low, high);
2176 HOST_WIDE_INT low, high;
2177 REAL_VALUE_TO_INT (&low, &high, x);
2178 t = build_int_2 (low, high);
2181 TREE_TYPE (t) = type;
2183 = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
2184 TREE_CONSTANT_OVERFLOW (t)
2185 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
2187 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
2188 TREE_TYPE (t) = type;
2190 else if (TREE_CODE (type) == REAL_TYPE)
2192 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
2193 if (TREE_CODE (arg1) == INTEGER_CST)
2194 return build_real_from_int_cst (type, arg1);
2195 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
2196 if (TREE_CODE (arg1) == REAL_CST)
2198 struct fc_args args;
2200 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
2203 TREE_TYPE (arg1) = type;
2207 /* Setup input for fold_convert_1() */
2211 if (do_float_handler (fold_convert_1, (PTR) &args))
2213 /* Receive output from fold_convert_1() */
2218 /* We got an exception from fold_convert_1() */
2220 t = copy_node (arg1);
2224 = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
2225 TREE_CONSTANT_OVERFLOW (t)
2226 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
2230 TREE_CONSTANT (t) = 1;
2234 /* Return an expr equal to X but certainly not valid as an lvalue. */
2242 /* These things are certainly not lvalues. */
2243 if (TREE_CODE (x) == NON_LVALUE_EXPR
2244 || TREE_CODE (x) == INTEGER_CST
2245 || TREE_CODE (x) == REAL_CST
2246 || TREE_CODE (x) == STRING_CST
2247 || TREE_CODE (x) == ADDR_EXPR)
2250 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
2251 TREE_CONSTANT (result) = TREE_CONSTANT (x);
2255 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
2256 Zero means allow extended lvalues. */
2258 int pedantic_lvalues;
2260 /* When pedantic, return an expr equal to X but certainly not valid as a
2261 pedantic lvalue. Otherwise, return X. */
2264 pedantic_non_lvalue (x)
2267 if (pedantic_lvalues)
2268 return non_lvalue (x);
2273 /* Given a tree comparison code, return the code that is the logical inverse
2274 of the given code. It is not safe to do this for floating-point
2275 comparisons, except for NE_EXPR and EQ_EXPR. */
2277 static enum tree_code
2278 invert_tree_comparison (code)
2279 enum tree_code code;
2300 /* Similar, but return the comparison that results if the operands are
2301 swapped. This is safe for floating-point. */
2303 static enum tree_code
2304 swap_tree_comparison (code)
2305 enum tree_code code;
2325 /* Return nonzero if CODE is a tree code that represents a truth value. */
2328 truth_value_p (code)
2329 enum tree_code code;
2331 return (TREE_CODE_CLASS (code) == '<'
2332 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2333 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2334 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
2337 /* Return nonzero if two operands are necessarily equal.
2338 If ONLY_CONST is non-zero, only return non-zero for constants.
2339 This function tests whether the operands are indistinguishable;
2340 it does not test whether they are equal using C's == operation.
2341 The distinction is important for IEEE floating point, because
2342 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2343 (2) two NaNs may be indistinguishable, but NaN!=NaN. */
2346 operand_equal_p (arg0, arg1, only_const)
2350 /* If both types don't have the same signedness, then we can't consider
2351 them equal. We must check this before the STRIP_NOPS calls
2352 because they may change the signedness of the arguments. */
2353 if (TREE_UNSIGNED (TREE_TYPE (arg0)) != TREE_UNSIGNED (TREE_TYPE (arg1)))
2359 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2360 /* This is needed for conversions and for COMPONENT_REF.
2361 Might as well play it safe and always test this. */
2362 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
2363 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
2364 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
2367 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
2368 We don't care about side effects in that case because the SAVE_EXPR
2369 takes care of that for us. In all other cases, two expressions are
2370 equal if they have no side effects. If we have two identical
2371 expressions with side effects that should be treated the same due
2372 to the only side effects being identical SAVE_EXPR's, that will
2373 be detected in the recursive calls below. */
2374 if (arg0 == arg1 && ! only_const
2375 && (TREE_CODE (arg0) == SAVE_EXPR
2376 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
2379 /* Next handle constant cases, those for which we can return 1 even
2380 if ONLY_CONST is set. */
2381 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
2382 switch (TREE_CODE (arg0))
2385 return (! TREE_CONSTANT_OVERFLOW (arg0)
2386 && ! TREE_CONSTANT_OVERFLOW (arg1)
2387 && tree_int_cst_equal (arg0, arg1));
2390 return (! TREE_CONSTANT_OVERFLOW (arg0)
2391 && ! TREE_CONSTANT_OVERFLOW (arg1)
2392 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
2393 TREE_REAL_CST (arg1)));
2396 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
2398 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
2402 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
2403 && ! memcmp (TREE_STRING_POINTER (arg0),
2404 TREE_STRING_POINTER (arg1),
2405 TREE_STRING_LENGTH (arg0)));
2408 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
2417 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
2420 /* Two conversions are equal only if signedness and modes match. */
2421 if ((TREE_CODE (arg0) == NOP_EXPR || TREE_CODE (arg0) == CONVERT_EXPR)
2422 && (TREE_UNSIGNED (TREE_TYPE (arg0))
2423 != TREE_UNSIGNED (TREE_TYPE (arg1))))
2426 return operand_equal_p (TREE_OPERAND (arg0, 0),
2427 TREE_OPERAND (arg1, 0), 0);
2431 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0)
2432 && operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1),
2436 /* For commutative ops, allow the other order. */
2437 return ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MULT_EXPR
2438 || TREE_CODE (arg0) == MIN_EXPR || TREE_CODE (arg0) == MAX_EXPR
2439 || TREE_CODE (arg0) == BIT_IOR_EXPR
2440 || TREE_CODE (arg0) == BIT_XOR_EXPR
2441 || TREE_CODE (arg0) == BIT_AND_EXPR
2442 || TREE_CODE (arg0) == NE_EXPR || TREE_CODE (arg0) == EQ_EXPR)
2443 && operand_equal_p (TREE_OPERAND (arg0, 0),
2444 TREE_OPERAND (arg1, 1), 0)
2445 && operand_equal_p (TREE_OPERAND (arg0, 1),
2446 TREE_OPERAND (arg1, 0), 0));
2449 /* If either of the pointer (or reference) expressions we are dereferencing
2450 contain a side effect, these cannot be equal. */
2451 if (TREE_SIDE_EFFECTS (arg0)
2452 || TREE_SIDE_EFFECTS (arg1))
2455 switch (TREE_CODE (arg0))
2458 return operand_equal_p (TREE_OPERAND (arg0, 0),
2459 TREE_OPERAND (arg1, 0), 0);
2463 case ARRAY_RANGE_REF:
2464 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2465 TREE_OPERAND (arg1, 0), 0)
2466 && operand_equal_p (TREE_OPERAND (arg0, 1),
2467 TREE_OPERAND (arg1, 1), 0));
2470 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2471 TREE_OPERAND (arg1, 0), 0)
2472 && operand_equal_p (TREE_OPERAND (arg0, 1),
2473 TREE_OPERAND (arg1, 1), 0)
2474 && operand_equal_p (TREE_OPERAND (arg0, 2),
2475 TREE_OPERAND (arg1, 2), 0));
2481 if (TREE_CODE (arg0) == RTL_EXPR)
2482 return rtx_equal_p (RTL_EXPR_RTL (arg0), RTL_EXPR_RTL (arg1));
2490 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2491 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2493 When in doubt, return 0. */
2496 operand_equal_for_comparison_p (arg0, arg1, other)
2500 int unsignedp1, unsignedpo;
2501 tree primarg0, primarg1, primother;
2502 unsigned int correct_width;
2504 if (operand_equal_p (arg0, arg1, 0))
2507 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
2508 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
2511 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2512 and see if the inner values are the same. This removes any
2513 signedness comparison, which doesn't matter here. */
2514 primarg0 = arg0, primarg1 = arg1;
2515 STRIP_NOPS (primarg0);
2516 STRIP_NOPS (primarg1);
2517 if (operand_equal_p (primarg0, primarg1, 0))
2520 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2521 actual comparison operand, ARG0.
2523 First throw away any conversions to wider types
2524 already present in the operands. */
2526 primarg1 = get_narrower (arg1, &unsignedp1);
2527 primother = get_narrower (other, &unsignedpo);
2529 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
2530 if (unsignedp1 == unsignedpo
2531 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
2532 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
2534 tree type = TREE_TYPE (arg0);
2536 /* Make sure shorter operand is extended the right way
2537 to match the longer operand. */
2538 primarg1 = convert (signed_or_unsigned_type (unsignedp1,
2539 TREE_TYPE (primarg1)),
2542 if (operand_equal_p (arg0, convert (type, primarg1), 0))
2549 /* See if ARG is an expression that is either a comparison or is performing
2550 arithmetic on comparisons. The comparisons must only be comparing
2551 two different values, which will be stored in *CVAL1 and *CVAL2; if
2552 they are non-zero it means that some operands have already been found.
2553 No variables may be used anywhere else in the expression except in the
2554 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2555 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2557 If this is true, return 1. Otherwise, return zero. */
2560 twoval_comparison_p (arg, cval1, cval2, save_p)
2562 tree *cval1, *cval2;
2565 enum tree_code code = TREE_CODE (arg);
2566 char class = TREE_CODE_CLASS (code);
2568 /* We can handle some of the 'e' cases here. */
2569 if (class == 'e' && code == TRUTH_NOT_EXPR)
2571 else if (class == 'e'
2572 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
2573 || code == COMPOUND_EXPR))
2576 else if (class == 'e' && code == SAVE_EXPR && SAVE_EXPR_RTL (arg) == 0
2577 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
2579 /* If we've already found a CVAL1 or CVAL2, this expression is
2580 two complex to handle. */
2581 if (*cval1 || *cval2)
2591 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
2594 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
2595 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2596 cval1, cval2, save_p));
2602 if (code == COND_EXPR)
2603 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
2604 cval1, cval2, save_p)
2605 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2606 cval1, cval2, save_p)
2607 && twoval_comparison_p (TREE_OPERAND (arg, 2),
2608 cval1, cval2, save_p));
2612 /* First see if we can handle the first operand, then the second. For
2613 the second operand, we know *CVAL1 can't be zero. It must be that
2614 one side of the comparison is each of the values; test for the
2615 case where this isn't true by failing if the two operands
2618 if (operand_equal_p (TREE_OPERAND (arg, 0),
2619 TREE_OPERAND (arg, 1), 0))
2623 *cval1 = TREE_OPERAND (arg, 0);
2624 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
2626 else if (*cval2 == 0)
2627 *cval2 = TREE_OPERAND (arg, 0);
2628 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
2633 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
2635 else if (*cval2 == 0)
2636 *cval2 = TREE_OPERAND (arg, 1);
2637 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
2649 /* ARG is a tree that is known to contain just arithmetic operations and
2650 comparisons. Evaluate the operations in the tree substituting NEW0 for
2651 any occurrence of OLD0 as an operand of a comparison and likewise for
2655 eval_subst (arg, old0, new0, old1, new1)
2657 tree old0, new0, old1, new1;
2659 tree type = TREE_TYPE (arg);
2660 enum tree_code code = TREE_CODE (arg);
2661 char class = TREE_CODE_CLASS (code);
2663 /* We can handle some of the 'e' cases here. */
2664 if (class == 'e' && code == TRUTH_NOT_EXPR)
2666 else if (class == 'e'
2667 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2673 return fold (build1 (code, type,
2674 eval_subst (TREE_OPERAND (arg, 0),
2675 old0, new0, old1, new1)));
2678 return fold (build (code, type,
2679 eval_subst (TREE_OPERAND (arg, 0),
2680 old0, new0, old1, new1),
2681 eval_subst (TREE_OPERAND (arg, 1),
2682 old0, new0, old1, new1)));
2688 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
2691 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
2694 return fold (build (code, type,
2695 eval_subst (TREE_OPERAND (arg, 0),
2696 old0, new0, old1, new1),
2697 eval_subst (TREE_OPERAND (arg, 1),
2698 old0, new0, old1, new1),
2699 eval_subst (TREE_OPERAND (arg, 2),
2700 old0, new0, old1, new1)));
2704 /* fall through - ??? */
2708 tree arg0 = TREE_OPERAND (arg, 0);
2709 tree arg1 = TREE_OPERAND (arg, 1);
2711 /* We need to check both for exact equality and tree equality. The
2712 former will be true if the operand has a side-effect. In that
2713 case, we know the operand occurred exactly once. */
2715 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
2717 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
2720 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
2722 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
2725 return fold (build (code, type, arg0, arg1));
2733 /* Return a tree for the case when the result of an expression is RESULT
2734 converted to TYPE and OMITTED was previously an operand of the expression
2735 but is now not needed (e.g., we folded OMITTED * 0).
2737 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2738 the conversion of RESULT to TYPE. */
2741 omit_one_operand (type, result, omitted)
2742 tree type, result, omitted;
2744 tree t = convert (type, result);
2746 if (TREE_SIDE_EFFECTS (omitted))
2747 return build (COMPOUND_EXPR, type, omitted, t);
2749 return non_lvalue (t);
2752 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2755 pedantic_omit_one_operand (type, result, omitted)
2756 tree type, result, omitted;
2758 tree t = convert (type, result);
2760 if (TREE_SIDE_EFFECTS (omitted))
2761 return build (COMPOUND_EXPR, type, omitted, t);
2763 return pedantic_non_lvalue (t);
2766 /* Return a simplified tree node for the truth-negation of ARG. This
2767 never alters ARG itself. We assume that ARG is an operation that
2768 returns a truth value (0 or 1). */
2771 invert_truthvalue (arg)
2774 tree type = TREE_TYPE (arg);
2775 enum tree_code code = TREE_CODE (arg);
2777 if (code == ERROR_MARK)
2780 /* If this is a comparison, we can simply invert it, except for
2781 floating-point non-equality comparisons, in which case we just
2782 enclose a TRUTH_NOT_EXPR around what we have. */
2784 if (TREE_CODE_CLASS (code) == '<')
2786 if (FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg, 0)))
2787 && !flag_unsafe_math_optimizations
2790 return build1 (TRUTH_NOT_EXPR, type, arg);
2792 return build (invert_tree_comparison (code), type,
2793 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
2799 return convert (type, build_int_2 (integer_zerop (arg), 0));
2801 case TRUTH_AND_EXPR:
2802 return build (TRUTH_OR_EXPR, type,
2803 invert_truthvalue (TREE_OPERAND (arg, 0)),
2804 invert_truthvalue (TREE_OPERAND (arg, 1)));
2807 return build (TRUTH_AND_EXPR, type,
2808 invert_truthvalue (TREE_OPERAND (arg, 0)),
2809 invert_truthvalue (TREE_OPERAND (arg, 1)));
2811 case TRUTH_XOR_EXPR:
2812 /* Here we can invert either operand. We invert the first operand
2813 unless the second operand is a TRUTH_NOT_EXPR in which case our
2814 result is the XOR of the first operand with the inside of the
2815 negation of the second operand. */
2817 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
2818 return build (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
2819 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
2821 return build (TRUTH_XOR_EXPR, type,
2822 invert_truthvalue (TREE_OPERAND (arg, 0)),
2823 TREE_OPERAND (arg, 1));
2825 case TRUTH_ANDIF_EXPR:
2826 return build (TRUTH_ORIF_EXPR, type,
2827 invert_truthvalue (TREE_OPERAND (arg, 0)),
2828 invert_truthvalue (TREE_OPERAND (arg, 1)));
2830 case TRUTH_ORIF_EXPR:
2831 return build (TRUTH_ANDIF_EXPR, type,
2832 invert_truthvalue (TREE_OPERAND (arg, 0)),
2833 invert_truthvalue (TREE_OPERAND (arg, 1)));
2835 case TRUTH_NOT_EXPR:
2836 return TREE_OPERAND (arg, 0);
2839 return build (COND_EXPR, type, TREE_OPERAND (arg, 0),
2840 invert_truthvalue (TREE_OPERAND (arg, 1)),
2841 invert_truthvalue (TREE_OPERAND (arg, 2)));
2844 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
2845 invert_truthvalue (TREE_OPERAND (arg, 1)));
2847 case WITH_RECORD_EXPR:
2848 return build (WITH_RECORD_EXPR, type,
2849 invert_truthvalue (TREE_OPERAND (arg, 0)),
2850 TREE_OPERAND (arg, 1));
2852 case NON_LVALUE_EXPR:
2853 return invert_truthvalue (TREE_OPERAND (arg, 0));
2858 return build1 (TREE_CODE (arg), type,
2859 invert_truthvalue (TREE_OPERAND (arg, 0)));
2862 if (!integer_onep (TREE_OPERAND (arg, 1)))
2864 return build (EQ_EXPR, type, arg, convert (type, integer_zero_node));
2867 return build1 (TRUTH_NOT_EXPR, type, arg);
2869 case CLEANUP_POINT_EXPR:
2870 return build1 (CLEANUP_POINT_EXPR, type,
2871 invert_truthvalue (TREE_OPERAND (arg, 0)));
2876 if (TREE_CODE (TREE_TYPE (arg)) != BOOLEAN_TYPE)
2878 return build1 (TRUTH_NOT_EXPR, type, arg);
2881 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
2882 operands are another bit-wise operation with a common input. If so,
2883 distribute the bit operations to save an operation and possibly two if
2884 constants are involved. For example, convert
2885 (A | B) & (A | C) into A | (B & C)
2886 Further simplification will occur if B and C are constants.
2888 If this optimization cannot be done, 0 will be returned. */
2891 distribute_bit_expr (code, type, arg0, arg1)
2892 enum tree_code code;
2899 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2900 || TREE_CODE (arg0) == code
2901 || (TREE_CODE (arg0) != BIT_AND_EXPR
2902 && TREE_CODE (arg0) != BIT_IOR_EXPR))
2905 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
2907 common = TREE_OPERAND (arg0, 0);
2908 left = TREE_OPERAND (arg0, 1);
2909 right = TREE_OPERAND (arg1, 1);
2911 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
2913 common = TREE_OPERAND (arg0, 0);
2914 left = TREE_OPERAND (arg0, 1);
2915 right = TREE_OPERAND (arg1, 0);
2917 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
2919 common = TREE_OPERAND (arg0, 1);
2920 left = TREE_OPERAND (arg0, 0);
2921 right = TREE_OPERAND (arg1, 1);
2923 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
2925 common = TREE_OPERAND (arg0, 1);
2926 left = TREE_OPERAND (arg0, 0);
2927 right = TREE_OPERAND (arg1, 0);
2932 return fold (build (TREE_CODE (arg0), type, common,
2933 fold (build (code, type, left, right))));
2936 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
2937 starting at BITPOS. The field is unsigned if UNSIGNEDP is non-zero. */
2940 make_bit_field_ref (inner, type, bitsize, bitpos, unsignedp)
2943 int bitsize, bitpos;
2946 tree result = build (BIT_FIELD_REF, type, inner,
2947 size_int (bitsize), bitsize_int (bitpos));
2949 TREE_UNSIGNED (result) = unsignedp;
2954 /* Optimize a bit-field compare.
2956 There are two cases: First is a compare against a constant and the
2957 second is a comparison of two items where the fields are at the same
2958 bit position relative to the start of a chunk (byte, halfword, word)
2959 large enough to contain it. In these cases we can avoid the shift
2960 implicit in bitfield extractions.
2962 For constants, we emit a compare of the shifted constant with the
2963 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
2964 compared. For two fields at the same position, we do the ANDs with the
2965 similar mask and compare the result of the ANDs.
2967 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
2968 COMPARE_TYPE is the type of the comparison, and LHS and RHS
2969 are the left and right operands of the comparison, respectively.
2971 If the optimization described above can be done, we return the resulting
2972 tree. Otherwise we return zero. */
2975 optimize_bit_field_compare (code, compare_type, lhs, rhs)
2976 enum tree_code code;
2980 HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
2981 tree type = TREE_TYPE (lhs);
2982 tree signed_type, unsigned_type;
2983 int const_p = TREE_CODE (rhs) == INTEGER_CST;
2984 enum machine_mode lmode, rmode, nmode;
2985 int lunsignedp, runsignedp;
2986 int lvolatilep = 0, rvolatilep = 0;
2987 unsigned int alignment;
2988 tree linner, rinner = NULL_TREE;
2992 /* Get all the information about the extractions being done. If the bit size
2993 if the same as the size of the underlying object, we aren't doing an
2994 extraction at all and so can do nothing. We also don't want to
2995 do anything if the inner expression is a PLACEHOLDER_EXPR since we
2996 then will no longer be able to replace it. */
2997 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
2998 &lunsignedp, &lvolatilep, &alignment);
2999 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
3000 || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
3005 /* If this is not a constant, we can only do something if bit positions,
3006 sizes, and signedness are the same. */
3007 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
3008 &runsignedp, &rvolatilep, &alignment);
3010 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
3011 || lunsignedp != runsignedp || offset != 0
3012 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
3016 /* See if we can find a mode to refer to this field. We should be able to,
3017 but fail if we can't. */
3018 nmode = get_best_mode (lbitsize, lbitpos,
3019 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
3020 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
3021 TYPE_ALIGN (TREE_TYPE (rinner))),
3022 word_mode, lvolatilep || rvolatilep);
3023 if (nmode == VOIDmode)
3026 /* Set signed and unsigned types of the precision of this mode for the
3028 signed_type = type_for_mode (nmode, 0);
3029 unsigned_type = type_for_mode (nmode, 1);
3031 /* Compute the bit position and size for the new reference and our offset
3032 within it. If the new reference is the same size as the original, we
3033 won't optimize anything, so return zero. */
3034 nbitsize = GET_MODE_BITSIZE (nmode);
3035 nbitpos = lbitpos & ~ (nbitsize - 1);
3037 if (nbitsize == lbitsize)
3040 if (BYTES_BIG_ENDIAN)
3041 lbitpos = nbitsize - lbitsize - lbitpos;
3043 /* Make the mask to be used against the extracted field. */
3044 mask = build_int_2 (~0, ~0);
3045 TREE_TYPE (mask) = unsigned_type;
3046 force_fit_type (mask, 0);
3047 mask = convert (unsigned_type, mask);
3048 mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
3049 mask = const_binop (RSHIFT_EXPR, mask,
3050 size_int (nbitsize - lbitsize - lbitpos), 0);
3053 /* If not comparing with constant, just rework the comparison
3055 return build (code, compare_type,
3056 build (BIT_AND_EXPR, unsigned_type,
3057 make_bit_field_ref (linner, unsigned_type,
3058 nbitsize, nbitpos, 1),
3060 build (BIT_AND_EXPR, unsigned_type,
3061 make_bit_field_ref (rinner, unsigned_type,
3062 nbitsize, nbitpos, 1),
3065 /* Otherwise, we are handling the constant case. See if the constant is too
3066 big for the field. Warn and return a tree of for 0 (false) if so. We do
3067 this not only for its own sake, but to avoid having to test for this
3068 error case below. If we didn't, we might generate wrong code.
3070 For unsigned fields, the constant shifted right by the field length should
3071 be all zero. For signed fields, the high-order bits should agree with
3076 if (! integer_zerop (const_binop (RSHIFT_EXPR,
3077 convert (unsigned_type, rhs),
3078 size_int (lbitsize), 0)))
3080 warning ("comparison is always %d due to width of bitfield",
3082 return convert (compare_type,
3084 ? integer_one_node : integer_zero_node));
3089 tree tem = const_binop (RSHIFT_EXPR, convert (signed_type, rhs),
3090 size_int (lbitsize - 1), 0);
3091 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
3093 warning ("comparison is always %d due to width of bitfield",
3095 return convert (compare_type,
3097 ? integer_one_node : integer_zero_node));
3101 /* Single-bit compares should always be against zero. */
3102 if (lbitsize == 1 && ! integer_zerop (rhs))
3104 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
3105 rhs = convert (type, integer_zero_node);
3108 /* Make a new bitfield reference, shift the constant over the
3109 appropriate number of bits and mask it with the computed mask
3110 (in case this was a signed field). If we changed it, make a new one. */
3111 lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1);
3114 TREE_SIDE_EFFECTS (lhs) = 1;
3115 TREE_THIS_VOLATILE (lhs) = 1;
3118 rhs = fold (const_binop (BIT_AND_EXPR,
3119 const_binop (LSHIFT_EXPR,
3120 convert (unsigned_type, rhs),
3121 size_int (lbitpos), 0),
3124 return build (code, compare_type,
3125 build (BIT_AND_EXPR, unsigned_type, lhs, mask),
3129 /* Subroutine for fold_truthop: decode a field reference.
3131 If EXP is a comparison reference, we return the innermost reference.
3133 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
3134 set to the starting bit number.
3136 If the innermost field can be completely contained in a mode-sized
3137 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
3139 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
3140 otherwise it is not changed.
3142 *PUNSIGNEDP is set to the signedness of the field.
3144 *PMASK is set to the mask used. This is either contained in a
3145 BIT_AND_EXPR or derived from the width of the field.
3147 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
3149 Return 0 if this is not a component reference or is one that we can't
3150 do anything with. */
3153 decode_field_reference (exp, pbitsize, pbitpos, pmode, punsignedp,
3154 pvolatilep, pmask, pand_mask)
3156 HOST_WIDE_INT *pbitsize, *pbitpos;
3157 enum machine_mode *pmode;
3158 int *punsignedp, *pvolatilep;
3163 tree mask, inner, offset;
3165 unsigned int precision;
3166 unsigned int alignment;
3168 /* All the optimizations using this function assume integer fields.
3169 There are problems with FP fields since the type_for_size call
3170 below can fail for, e.g., XFmode. */
3171 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
3176 if (TREE_CODE (exp) == BIT_AND_EXPR)
3178 and_mask = TREE_OPERAND (exp, 1);
3179 exp = TREE_OPERAND (exp, 0);
3180 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
3181 if (TREE_CODE (and_mask) != INTEGER_CST)
3185 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
3186 punsignedp, pvolatilep, &alignment);
3187 if ((inner == exp && and_mask == 0)
3188 || *pbitsize < 0 || offset != 0
3189 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
3192 /* Compute the mask to access the bitfield. */
3193 unsigned_type = type_for_size (*pbitsize, 1);
3194 precision = TYPE_PRECISION (unsigned_type);
3196 mask = build_int_2 (~0, ~0);
3197 TREE_TYPE (mask) = unsigned_type;
3198 force_fit_type (mask, 0);
3199 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3200 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3202 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
3204 mask = fold (build (BIT_AND_EXPR, unsigned_type,
3205 convert (unsigned_type, and_mask), mask));
3208 *pand_mask = and_mask;
3212 /* Return non-zero if MASK represents a mask of SIZE ones in the low-order
3216 all_ones_mask_p (mask, size)
3220 tree type = TREE_TYPE (mask);
3221 unsigned int precision = TYPE_PRECISION (type);
3224 tmask = build_int_2 (~0, ~0);
3225 TREE_TYPE (tmask) = signed_type (type);
3226 force_fit_type (tmask, 0);
3228 tree_int_cst_equal (mask,
3229 const_binop (RSHIFT_EXPR,
3230 const_binop (LSHIFT_EXPR, tmask,
3231 size_int (precision - size),
3233 size_int (precision - size), 0));
3236 /* Subroutine for fold_truthop: determine if an operand is simple enough
3237 to be evaluated unconditionally. */
3240 simple_operand_p (exp)
3243 /* Strip any conversions that don't change the machine mode. */
3244 while ((TREE_CODE (exp) == NOP_EXPR
3245 || TREE_CODE (exp) == CONVERT_EXPR)
3246 && (TYPE_MODE (TREE_TYPE (exp))
3247 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)))))
3248 exp = TREE_OPERAND (exp, 0);
3250 return (TREE_CODE_CLASS (TREE_CODE (exp)) == 'c'
3252 && ! TREE_ADDRESSABLE (exp)
3253 && ! TREE_THIS_VOLATILE (exp)
3254 && ! DECL_NONLOCAL (exp)
3255 /* Don't regard global variables as simple. They may be
3256 allocated in ways unknown to the compiler (shared memory,
3257 #pragma weak, etc). */
3258 && ! TREE_PUBLIC (exp)
3259 && ! DECL_EXTERNAL (exp)
3260 /* Loading a static variable is unduly expensive, but global
3261 registers aren't expensive. */
3262 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
3265 /* The following functions are subroutines to fold_range_test and allow it to
3266 try to change a logical combination of comparisons into a range test.
3269 X == 2 || X == 3 || X == 4 || X == 5
3273 (unsigned) (X - 2) <= 3
3275 We describe each set of comparisons as being either inside or outside
3276 a range, using a variable named like IN_P, and then describe the
3277 range with a lower and upper bound. If one of the bounds is omitted,
3278 it represents either the highest or lowest value of the type.
3280 In the comments below, we represent a range by two numbers in brackets
3281 preceded by a "+" to designate being inside that range, or a "-" to
3282 designate being outside that range, so the condition can be inverted by
3283 flipping the prefix. An omitted bound is represented by a "-". For
3284 example, "- [-, 10]" means being outside the range starting at the lowest
3285 possible value and ending at 10, in other words, being greater than 10.
3286 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
3289 We set up things so that the missing bounds are handled in a consistent
3290 manner so neither a missing bound nor "true" and "false" need to be
3291 handled using a special case. */
3293 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
3294 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
3295 and UPPER1_P are nonzero if the respective argument is an upper bound
3296 and zero for a lower. TYPE, if nonzero, is the type of the result; it
3297 must be specified for a comparison. ARG1 will be converted to ARG0's
3298 type if both are specified. */
3301 range_binop (code, type, arg0, upper0_p, arg1, upper1_p)
3302 enum tree_code code;
3305 int upper0_p, upper1_p;
3311 /* If neither arg represents infinity, do the normal operation.
3312 Else, if not a comparison, return infinity. Else handle the special
3313 comparison rules. Note that most of the cases below won't occur, but
3314 are handled for consistency. */
3316 if (arg0 != 0 && arg1 != 0)
3318 tem = fold (build (code, type != 0 ? type : TREE_TYPE (arg0),
3319 arg0, convert (TREE_TYPE (arg0), arg1)));
3321 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
3324 if (TREE_CODE_CLASS (code) != '<')
3327 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
3328 for neither. In real maths, we cannot assume open ended ranges are
3329 the same. But, this is computer arithmetic, where numbers are finite.
3330 We can therefore make the transformation of any unbounded range with
3331 the value Z, Z being greater than any representable number. This permits
3332 us to treat unbounded ranges as equal. */
3333 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
3334 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
3338 result = sgn0 == sgn1;
3341 result = sgn0 != sgn1;
3344 result = sgn0 < sgn1;
3347 result = sgn0 <= sgn1;
3350 result = sgn0 > sgn1;
3353 result = sgn0 >= sgn1;
3359 return convert (type, result ? integer_one_node : integer_zero_node);
3362 /* Given EXP, a logical expression, set the range it is testing into
3363 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
3364 actually being tested. *PLOW and *PHIGH will be made of the same type
3365 as the returned expression. If EXP is not a comparison, we will most
3366 likely not be returning a useful value and range. */
3369 make_range (exp, pin_p, plow, phigh)
3374 enum tree_code code;
3375 tree arg0 = NULL_TREE, arg1 = NULL_TREE, type = NULL_TREE;
3376 tree orig_type = NULL_TREE;
3378 tree low, high, n_low, n_high;
3380 /* Start with simply saying "EXP != 0" and then look at the code of EXP
3381 and see if we can refine the range. Some of the cases below may not
3382 happen, but it doesn't seem worth worrying about this. We "continue"
3383 the outer loop when we've changed something; otherwise we "break"
3384 the switch, which will "break" the while. */
3386 in_p = 0, low = high = convert (TREE_TYPE (exp), integer_zero_node);
3390 code = TREE_CODE (exp);
3392 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
3394 arg0 = TREE_OPERAND (exp, 0);
3395 if (TREE_CODE_CLASS (code) == '<'
3396 || TREE_CODE_CLASS (code) == '1'
3397 || TREE_CODE_CLASS (code) == '2')
3398 type = TREE_TYPE (arg0);
3399 if (TREE_CODE_CLASS (code) == '2'
3400 || TREE_CODE_CLASS (code) == '<'
3401 || (TREE_CODE_CLASS (code) == 'e'
3402 && TREE_CODE_LENGTH (code) > 1))
3403 arg1 = TREE_OPERAND (exp, 1);
3406 /* Set ORIG_TYPE as soon as TYPE is non-null so that we do not
3407 lose a cast by accident. */
3408 if (type != NULL_TREE && orig_type == NULL_TREE)
3413 case TRUTH_NOT_EXPR:
3414 in_p = ! in_p, exp = arg0;
3417 case EQ_EXPR: case NE_EXPR:
3418 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
3419 /* We can only do something if the range is testing for zero
3420 and if the second operand is an integer constant. Note that
3421 saying something is "in" the range we make is done by
3422 complementing IN_P since it will set in the initial case of
3423 being not equal to zero; "out" is leaving it alone. */
3424 if (low == 0 || high == 0
3425 || ! integer_zerop (low) || ! integer_zerop (high)
3426 || TREE_CODE (arg1) != INTEGER_CST)
3431 case NE_EXPR: /* - [c, c] */
3434 case EQ_EXPR: /* + [c, c] */
3435 in_p = ! in_p, low = high = arg1;
3437 case GT_EXPR: /* - [-, c] */
3438 low = 0, high = arg1;
3440 case GE_EXPR: /* + [c, -] */
3441 in_p = ! in_p, low = arg1, high = 0;
3443 case LT_EXPR: /* - [c, -] */
3444 low = arg1, high = 0;
3446 case LE_EXPR: /* + [-, c] */
3447 in_p = ! in_p, low = 0, high = arg1;
3455 /* If this is an unsigned comparison, we also know that EXP is
3456 greater than or equal to zero. We base the range tests we make
3457 on that fact, so we record it here so we can parse existing
3459 if (TREE_UNSIGNED (type) && (low == 0 || high == 0))
3461 if (! merge_ranges (&n_in_p, &n_low, &n_high, in_p, low, high,
3462 1, convert (type, integer_zero_node),
3466 in_p = n_in_p, low = n_low, high = n_high;
3468 /* If the high bound is missing, but we
3469 have a low bound, reverse the range so
3470 it goes from zero to the low bound minus 1. */
3471 if (high == 0 && low)
3474 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
3475 integer_one_node, 0);
3476 low = convert (type, integer_zero_node);
3482 /* (-x) IN [a,b] -> x in [-b, -a] */
3483 n_low = range_binop (MINUS_EXPR, type,
3484 convert (type, integer_zero_node), 0, high, 1);
3485 n_high = range_binop (MINUS_EXPR, type,
3486 convert (type, integer_zero_node), 0, low, 0);
3487 low = n_low, high = n_high;
3493 exp = build (MINUS_EXPR, type, negate_expr (arg0),
3494 convert (type, integer_one_node));
3497 case PLUS_EXPR: case MINUS_EXPR:
3498 if (TREE_CODE (arg1) != INTEGER_CST)
3501 /* If EXP is signed, any overflow in the computation is undefined,
3502 so we don't worry about it so long as our computations on
3503 the bounds don't overflow. For unsigned, overflow is defined
3504 and this is exactly the right thing. */
3505 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3506 type, low, 0, arg1, 0);
3507 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3508 type, high, 1, arg1, 0);
3509 if ((n_low != 0 && TREE_OVERFLOW (n_low))
3510 || (n_high != 0 && TREE_OVERFLOW (n_high)))
3513 /* Check for an unsigned range which has wrapped around the maximum
3514 value thus making n_high < n_low, and normalize it. */
3515 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
3517 low = range_binop (PLUS_EXPR, type, n_high, 0,
3518 integer_one_node, 0);
3519 high = range_binop (MINUS_EXPR, type, n_low, 0,
3520 integer_one_node, 0);
3522 /* If the range is of the form +/- [ x+1, x ], we won't
3523 be able to normalize it. But then, it represents the
3524 whole range or the empty set, so make it
3526 if (tree_int_cst_equal (n_low, low)
3527 && tree_int_cst_equal (n_high, high))
3533 low = n_low, high = n_high;
3538 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
3539 if (TYPE_PRECISION (type) > TYPE_PRECISION (orig_type))
3542 if (! INTEGRAL_TYPE_P (type)
3543 || (low != 0 && ! int_fits_type_p (low, type))
3544 || (high != 0 && ! int_fits_type_p (high, type)))
3547 n_low = low, n_high = high;
3550 n_low = convert (type, n_low);
3553 n_high = convert (type, n_high);
3555 /* If we're converting from an unsigned to a signed type,
3556 we will be doing the comparison as unsigned. The tests above
3557 have already verified that LOW and HIGH are both positive.
3559 So we have to make sure that the original unsigned value will
3560 be interpreted as positive. */
3561 if (TREE_UNSIGNED (type) && ! TREE_UNSIGNED (TREE_TYPE (exp)))
3563 tree equiv_type = type_for_mode (TYPE_MODE (type), 1);
3566 /* A range without an upper bound is, naturally, unbounded.
3567 Since convert would have cropped a very large value, use
3568 the max value for the destination type. */
3570 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
3571 : TYPE_MAX_VALUE (type);
3573 high_positive = fold (build (RSHIFT_EXPR, type,
3574 convert (type, high_positive),
3575 convert (type, integer_one_node)));
3577 /* If the low bound is specified, "and" the range with the
3578 range for which the original unsigned value will be
3582 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3584 1, convert (type, integer_zero_node),
3588 in_p = (n_in_p == in_p);
3592 /* Otherwise, "or" the range with the range of the input
3593 that will be interpreted as negative. */
3594 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3596 1, convert (type, integer_zero_node),
3600 in_p = (in_p != n_in_p);
3605 low = n_low, high = n_high;
3615 /* If EXP is a constant, we can evaluate whether this is true or false. */
3616 if (TREE_CODE (exp) == INTEGER_CST)
3618 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
3620 && integer_onep (range_binop (LE_EXPR, integer_type_node,
3626 *pin_p = in_p, *plow = low, *phigh = high;
3630 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3631 type, TYPE, return an expression to test if EXP is in (or out of, depending
3632 on IN_P) the range. */
3635 build_range_check (type, exp, in_p, low, high)
3641 tree etype = TREE_TYPE (exp);
3645 && (0 != (value = build_range_check (type, exp, 1, low, high))))
3646 return invert_truthvalue (value);
3648 else if (low == 0 && high == 0)
3649 return convert (type, integer_one_node);
3652 return fold (build (LE_EXPR, type, exp, high));
3655 return fold (build (GE_EXPR, type, exp, low));
3657 else if (operand_equal_p (low, high, 0))
3658 return fold (build (EQ_EXPR, type, exp, low));
3660 else if (TREE_UNSIGNED (etype) && integer_zerop (low))
3661 return build_range_check (type, exp, 1, 0, high);
3663 else if (integer_zerop (low))
3665 utype = unsigned_type (etype);
3666 return build_range_check (type, convert (utype, exp), 1, 0,
3667 convert (utype, high));
3670 else if (0 != (value = const_binop (MINUS_EXPR, high, low, 0))
3671 && ! TREE_OVERFLOW (value))
3672 return build_range_check (type,
3673 fold (build (MINUS_EXPR, etype, exp, low)),
3674 1, convert (etype, integer_zero_node), value);
3679 /* Given two ranges, see if we can merge them into one. Return 1 if we
3680 can, 0 if we can't. Set the output range into the specified parameters. */
3683 merge_ranges (pin_p, plow, phigh, in0_p, low0, high0, in1_p, low1, high1)
3687 tree low0, high0, low1, high1;
3695 int lowequal = ((low0 == 0 && low1 == 0)
3696 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3697 low0, 0, low1, 0)));
3698 int highequal = ((high0 == 0 && high1 == 0)
3699 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3700 high0, 1, high1, 1)));
3702 /* Make range 0 be the range that starts first, or ends last if they
3703 start at the same value. Swap them if it isn't. */
3704 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
3707 && integer_onep (range_binop (GT_EXPR, integer_type_node,
3708 high1, 1, high0, 1))))
3710 temp = in0_p, in0_p = in1_p, in1_p = temp;
3711 tem = low0, low0 = low1, low1 = tem;
3712 tem = high0, high0 = high1, high1 = tem;
3715 /* Now flag two cases, whether the ranges are disjoint or whether the
3716 second range is totally subsumed in the first. Note that the tests
3717 below are simplified by the ones above. */
3718 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
3719 high0, 1, low1, 0));
3720 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
3721 high1, 1, high0, 1));
3723 /* We now have four cases, depending on whether we are including or
3724 excluding the two ranges. */
3727 /* If they don't overlap, the result is false. If the second range
3728 is a subset it is the result. Otherwise, the range is from the start
3729 of the second to the end of the first. */
3731 in_p = 0, low = high = 0;
3733 in_p = 1, low = low1, high = high1;
3735 in_p = 1, low = low1, high = high0;
3738 else if (in0_p && ! in1_p)
3740 /* If they don't overlap, the result is the first range. If they are
3741 equal, the result is false. If the second range is a subset of the
3742 first, and the ranges begin at the same place, we go from just after
3743 the end of the first range to the end of the second. If the second
3744 range is not a subset of the first, or if it is a subset and both
3745 ranges end at the same place, the range starts at the start of the
3746 first range and ends just before the second range.
3747 Otherwise, we can't describe this as a single range. */
3749 in_p = 1, low = low0, high = high0;
3750 else if (lowequal && highequal)
3751 in_p = 0, low = high = 0;
3752 else if (subset && lowequal)
3754 in_p = 1, high = high0;
3755 low = range_binop (PLUS_EXPR, NULL_TREE, high1, 0,
3756 integer_one_node, 0);
3758 else if (! subset || highequal)
3760 in_p = 1, low = low0;
3761 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
3762 integer_one_node, 0);
3768 else if (! in0_p && in1_p)
3770 /* If they don't overlap, the result is the second range. If the second
3771 is a subset of the first, the result is false. Otherwise,
3772 the range starts just after the first range and ends at the
3773 end of the second. */
3775 in_p = 1, low = low1, high = high1;
3776 else if (subset || highequal)
3777 in_p = 0, low = high = 0;
3780 in_p = 1, high = high1;
3781 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
3782 integer_one_node, 0);
3788 /* The case where we are excluding both ranges. Here the complex case
3789 is if they don't overlap. In that case, the only time we have a
3790 range is if they are adjacent. If the second is a subset of the
3791 first, the result is the first. Otherwise, the range to exclude
3792 starts at the beginning of the first range and ends at the end of the
3796 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
3797 range_binop (PLUS_EXPR, NULL_TREE,
3799 integer_one_node, 1),
3801 in_p = 0, low = low0, high = high1;
3806 in_p = 0, low = low0, high = high0;
3808 in_p = 0, low = low0, high = high1;
3811 *pin_p = in_p, *plow = low, *phigh = high;
3815 /* EXP is some logical combination of boolean tests. See if we can
3816 merge it into some range test. Return the new tree if so. */
3819 fold_range_test (exp)
3822 int or_op = (TREE_CODE (exp) == TRUTH_ORIF_EXPR
3823 || TREE_CODE (exp) == TRUTH_OR_EXPR);
3824 int in0_p, in1_p, in_p;
3825 tree low0, low1, low, high0, high1, high;
3826 tree lhs = make_range (TREE_OPERAND (exp, 0), &in0_p, &low0, &high0);
3827 tree rhs = make_range (TREE_OPERAND (exp, 1), &in1_p, &low1, &high1);
3830 /* If this is an OR operation, invert both sides; we will invert
3831 again at the end. */
3833 in0_p = ! in0_p, in1_p = ! in1_p;
3835 /* If both expressions are the same, if we can merge the ranges, and we
3836 can build the range test, return it or it inverted. If one of the
3837 ranges is always true or always false, consider it to be the same
3838 expression as the other. */
3839 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
3840 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
3842 && 0 != (tem = (build_range_check (TREE_TYPE (exp),
3844 : rhs != 0 ? rhs : integer_zero_node,
3846 return or_op ? invert_truthvalue (tem) : tem;
3848 /* On machines where the branch cost is expensive, if this is a
3849 short-circuited branch and the underlying object on both sides
3850 is the same, make a non-short-circuit operation. */
3851 else if (BRANCH_COST >= 2
3852 && lhs != 0 && rhs != 0
3853 && (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3854 || TREE_CODE (exp) == TRUTH_ORIF_EXPR)
3855 && operand_equal_p (lhs, rhs, 0))
3857 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
3858 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
3859 which cases we can't do this. */
3860 if (simple_operand_p (lhs))
3861 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3862 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3863 TREE_TYPE (exp), TREE_OPERAND (exp, 0),
3864 TREE_OPERAND (exp, 1));
3866 else if (global_bindings_p () == 0
3867 && ! contains_placeholder_p (lhs))
3869 tree common = save_expr (lhs);
3871 if (0 != (lhs = build_range_check (TREE_TYPE (exp), common,
3872 or_op ? ! in0_p : in0_p,
3874 && (0 != (rhs = build_range_check (TREE_TYPE (exp), common,
3875 or_op ? ! in1_p : in1_p,
3877 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3878 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3879 TREE_TYPE (exp), lhs, rhs);
3886 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
3887 bit value. Arrange things so the extra bits will be set to zero if and
3888 only if C is signed-extended to its full width. If MASK is nonzero,
3889 it is an INTEGER_CST that should be AND'ed with the extra bits. */
3892 unextend (c, p, unsignedp, mask)
3898 tree type = TREE_TYPE (c);
3899 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
3902 if (p == modesize || unsignedp)
3905 /* We work by getting just the sign bit into the low-order bit, then
3906 into the high-order bit, then sign-extend. We then XOR that value
3908 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
3909 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
3911 /* We must use a signed type in order to get an arithmetic right shift.
3912 However, we must also avoid introducing accidental overflows, so that
3913 a subsequent call to integer_zerop will work. Hence we must
3914 do the type conversion here. At this point, the constant is either
3915 zero or one, and the conversion to a signed type can never overflow.
3916 We could get an overflow if this conversion is done anywhere else. */
3917 if (TREE_UNSIGNED (type))
3918 temp = convert (signed_type (type), temp);
3920 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
3921 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
3923 temp = const_binop (BIT_AND_EXPR, temp, convert (TREE_TYPE (c), mask), 0);
3924 /* If necessary, convert the type back to match the type of C. */
3925 if (TREE_UNSIGNED (type))
3926 temp = convert (type, temp);
3928 return convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
3931 /* Find ways of folding logical expressions of LHS and RHS:
3932 Try to merge two comparisons to the same innermost item.
3933 Look for range tests like "ch >= '0' && ch <= '9'".
3934 Look for combinations of simple terms on machines with expensive branches
3935 and evaluate the RHS unconditionally.
3937 For example, if we have p->a == 2 && p->b == 4 and we can make an
3938 object large enough to span both A and B, we can do this with a comparison
3939 against the object ANDed with the a mask.
3941 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
3942 operations to do this with one comparison.
3944 We check for both normal comparisons and the BIT_AND_EXPRs made this by
3945 function and the one above.
3947 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
3948 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
3950 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
3953 We return the simplified tree or 0 if no optimization is possible. */
3956 fold_truthop (code, truth_type, lhs, rhs)
3957 enum tree_code code;
3958 tree truth_type, lhs, rhs;
3960 /* If this is the "or" of two comparisons, we can do something if
3961 the comparisons are NE_EXPR. If this is the "and", we can do something
3962 if the comparisons are EQ_EXPR. I.e.,
3963 (a->b == 2 && a->c == 4) can become (a->new == NEW).
3965 WANTED_CODE is this operation code. For single bit fields, we can
3966 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
3967 comparison for one-bit fields. */
3969 enum tree_code wanted_code;
3970 enum tree_code lcode, rcode;
3971 tree ll_arg, lr_arg, rl_arg, rr_arg;
3972 tree ll_inner, lr_inner, rl_inner, rr_inner;
3973 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
3974 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
3975 HOST_WIDE_INT xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
3976 HOST_WIDE_INT lnbitsize, lnbitpos, rnbitsize, rnbitpos;
3977 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
3978 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
3979 enum machine_mode lnmode, rnmode;
3980 tree ll_mask, lr_mask, rl_mask, rr_mask;
3981 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
3982 tree l_const, r_const;
3983 tree lntype, rntype, result;
3984 int first_bit, end_bit;
3987 /* Start by getting the comparison codes. Fail if anything is volatile.
3988 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
3989 it were surrounded with a NE_EXPR. */
3991 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
3994 lcode = TREE_CODE (lhs);
3995 rcode = TREE_CODE (rhs);
3997 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
3998 lcode = NE_EXPR, lhs = build (NE_EXPR, truth_type, lhs, integer_zero_node);
4000 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
4001 rcode = NE_EXPR, rhs = build (NE_EXPR, truth_type, rhs, integer_zero_node);
4003 if (TREE_CODE_CLASS (lcode) != '<' || TREE_CODE_CLASS (rcode) != '<')
4006 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
4007 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
4009 ll_arg = TREE_OPERAND (lhs, 0);
4010 lr_arg = TREE_OPERAND (lhs, 1);
4011 rl_arg = TREE_OPERAND (rhs, 0);
4012 rr_arg = TREE_OPERAND (rhs, 1);
4014 /* If the RHS can be evaluated unconditionally and its operands are
4015 simple, it wins to evaluate the RHS unconditionally on machines
4016 with expensive branches. In this case, this isn't a comparison
4017 that can be merged. Avoid doing this if the RHS is a floating-point
4018 comparison since those can trap. */
4020 if (BRANCH_COST >= 2
4021 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
4022 && simple_operand_p (rl_arg)
4023 && simple_operand_p (rr_arg))
4024 return build (code, truth_type, lhs, rhs);
4026 /* See if the comparisons can be merged. Then get all the parameters for
4029 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
4030 || (rcode != EQ_EXPR && rcode != NE_EXPR))
4034 ll_inner = decode_field_reference (ll_arg,
4035 &ll_bitsize, &ll_bitpos, &ll_mode,
4036 &ll_unsignedp, &volatilep, &ll_mask,
4038 lr_inner = decode_field_reference (lr_arg,
4039 &lr_bitsize, &lr_bitpos, &lr_mode,
4040 &lr_unsignedp, &volatilep, &lr_mask,
4042 rl_inner = decode_field_reference (rl_arg,
4043 &rl_bitsize, &rl_bitpos, &rl_mode,
4044 &rl_unsignedp, &volatilep, &rl_mask,
4046 rr_inner = decode_field_reference (rr_arg,
4047 &rr_bitsize, &rr_bitpos, &rr_mode,
4048 &rr_unsignedp, &volatilep, &rr_mask,
4051 /* It must be true that the inner operation on the lhs of each
4052 comparison must be the same if we are to be able to do anything.
4053 Then see if we have constants. If not, the same must be true for
4055 if (volatilep || ll_inner == 0 || rl_inner == 0
4056 || ! operand_equal_p (ll_inner, rl_inner, 0))
4059 if (TREE_CODE (lr_arg) == INTEGER_CST
4060 && TREE_CODE (rr_arg) == INTEGER_CST)
4061 l_const = lr_arg, r_const = rr_arg;
4062 else if (lr_inner == 0 || rr_inner == 0
4063 || ! operand_equal_p (lr_inner, rr_inner, 0))
4066 l_const = r_const = 0;
4068 /* If either comparison code is not correct for our logical operation,
4069 fail. However, we can convert a one-bit comparison against zero into
4070 the opposite comparison against that bit being set in the field. */
4072 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
4073 if (lcode != wanted_code)
4075 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
4077 /* Make the left operand unsigned, since we are only interested
4078 in the value of one bit. Otherwise we are doing the wrong
4087 /* This is analogous to the code for l_const above. */
4088 if (rcode != wanted_code)
4090 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
4099 /* See if we can find a mode that contains both fields being compared on
4100 the left. If we can't, fail. Otherwise, update all constants and masks
4101 to be relative to a field of that size. */
4102 first_bit = MIN (ll_bitpos, rl_bitpos);
4103 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
4104 lnmode = get_best_mode (end_bit - first_bit, first_bit,
4105 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
4107 if (lnmode == VOIDmode)
4110 lnbitsize = GET_MODE_BITSIZE (lnmode);
4111 lnbitpos = first_bit & ~ (lnbitsize - 1);
4112 lntype = type_for_size (lnbitsize, 1);
4113 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
4115 if (BYTES_BIG_ENDIAN)
4117 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
4118 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
4121 ll_mask = const_binop (LSHIFT_EXPR, convert (lntype, ll_mask),
4122 size_int (xll_bitpos), 0);
4123 rl_mask = const_binop (LSHIFT_EXPR, convert (lntype, rl_mask),
4124 size_int (xrl_bitpos), 0);
4128 l_const = convert (lntype, l_const);
4129 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
4130 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
4131 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
4132 fold (build1 (BIT_NOT_EXPR,
4136 warning ("comparison is always %d", wanted_code == NE_EXPR);
4138 return convert (truth_type,
4139 wanted_code == NE_EXPR
4140 ? integer_one_node : integer_zero_node);
4145 r_const = convert (lntype, r_const);
4146 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
4147 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
4148 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
4149 fold (build1 (BIT_NOT_EXPR,
4153 warning ("comparison is always %d", wanted_code == NE_EXPR);
4155 return convert (truth_type,
4156 wanted_code == NE_EXPR
4157 ? integer_one_node : integer_zero_node);
4161 /* If the right sides are not constant, do the same for it. Also,
4162 disallow this optimization if a size or signedness mismatch occurs
4163 between the left and right sides. */
4166 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
4167 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
4168 /* Make sure the two fields on the right
4169 correspond to the left without being swapped. */
4170 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
4173 first_bit = MIN (lr_bitpos, rr_bitpos);
4174 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
4175 rnmode = get_best_mode (end_bit - first_bit, first_bit,
4176 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
4178 if (rnmode == VOIDmode)
4181 rnbitsize = GET_MODE_BITSIZE (rnmode);
4182 rnbitpos = first_bit & ~ (rnbitsize - 1);
4183 rntype = type_for_size (rnbitsize, 1);
4184 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
4186 if (BYTES_BIG_ENDIAN)
4188 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
4189 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
4192 lr_mask = const_binop (LSHIFT_EXPR, convert (rntype, lr_mask),
4193 size_int (xlr_bitpos), 0);
4194 rr_mask = const_binop (LSHIFT_EXPR, convert (rntype, rr_mask),
4195 size_int (xrr_bitpos), 0);
4197 /* Make a mask that corresponds to both fields being compared.
4198 Do this for both items being compared. If the operands are the
4199 same size and the bits being compared are in the same position
4200 then we can do this by masking both and comparing the masked
4202 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4203 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
4204 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
4206 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4207 ll_unsignedp || rl_unsignedp);
4208 if (! all_ones_mask_p (ll_mask, lnbitsize))
4209 lhs = build (BIT_AND_EXPR, lntype, lhs, ll_mask);
4211 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
4212 lr_unsignedp || rr_unsignedp);
4213 if (! all_ones_mask_p (lr_mask, rnbitsize))
4214 rhs = build (BIT_AND_EXPR, rntype, rhs, lr_mask);
4216 return build (wanted_code, truth_type, lhs, rhs);
4219 /* There is still another way we can do something: If both pairs of
4220 fields being compared are adjacent, we may be able to make a wider
4221 field containing them both.
4223 Note that we still must mask the lhs/rhs expressions. Furthermore,
4224 the mask must be shifted to account for the shift done by
4225 make_bit_field_ref. */
4226 if ((ll_bitsize + ll_bitpos == rl_bitpos
4227 && lr_bitsize + lr_bitpos == rr_bitpos)
4228 || (ll_bitpos == rl_bitpos + rl_bitsize
4229 && lr_bitpos == rr_bitpos + rr_bitsize))
4233 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
4234 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
4235 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
4236 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
4238 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
4239 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
4240 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
4241 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
4243 /* Convert to the smaller type before masking out unwanted bits. */
4245 if (lntype != rntype)
4247 if (lnbitsize > rnbitsize)
4249 lhs = convert (rntype, lhs);
4250 ll_mask = convert (rntype, ll_mask);
4253 else if (lnbitsize < rnbitsize)
4255 rhs = convert (lntype, rhs);
4256 lr_mask = convert (lntype, lr_mask);
4261 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
4262 lhs = build (BIT_AND_EXPR, type, lhs, ll_mask);
4264 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
4265 rhs = build (BIT_AND_EXPR, type, rhs, lr_mask);
4267 return build (wanted_code, truth_type, lhs, rhs);
4273 /* Handle the case of comparisons with constants. If there is something in
4274 common between the masks, those bits of the constants must be the same.
4275 If not, the condition is always false. Test for this to avoid generating
4276 incorrect code below. */
4277 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
4278 if (! integer_zerop (result)
4279 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
4280 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
4282 if (wanted_code == NE_EXPR)
4284 warning ("`or' of unmatched not-equal tests is always 1");
4285 return convert (truth_type, integer_one_node);
4289 warning ("`and' of mutually exclusive equal-tests is always 0");
4290 return convert (truth_type, integer_zero_node);
4294 /* Construct the expression we will return. First get the component
4295 reference we will make. Unless the mask is all ones the width of
4296 that field, perform the mask operation. Then compare with the
4298 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4299 ll_unsignedp || rl_unsignedp);
4301 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4302 if (! all_ones_mask_p (ll_mask, lnbitsize))
4303 result = build (BIT_AND_EXPR, lntype, result, ll_mask);
4305 return build (wanted_code, truth_type, result,
4306 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
4309 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
4313 optimize_minmax_comparison (t)
4316 tree type = TREE_TYPE (t);
4317 tree arg0 = TREE_OPERAND (t, 0);
4318 enum tree_code op_code;
4319 tree comp_const = TREE_OPERAND (t, 1);
4321 int consts_equal, consts_lt;
4324 STRIP_SIGN_NOPS (arg0);
4326 op_code = TREE_CODE (arg0);
4327 minmax_const = TREE_OPERAND (arg0, 1);
4328 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
4329 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
4330 inner = TREE_OPERAND (arg0, 0);
4332 /* If something does not permit us to optimize, return the original tree. */
4333 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
4334 || TREE_CODE (comp_const) != INTEGER_CST
4335 || TREE_CONSTANT_OVERFLOW (comp_const)
4336 || TREE_CODE (minmax_const) != INTEGER_CST
4337 || TREE_CONSTANT_OVERFLOW (minmax_const))
4340 /* Now handle all the various comparison codes. We only handle EQ_EXPR
4341 and GT_EXPR, doing the rest with recursive calls using logical
4343 switch (TREE_CODE (t))
4345 case NE_EXPR: case LT_EXPR: case LE_EXPR:
4347 invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t)));
4351 fold (build (TRUTH_ORIF_EXPR, type,
4352 optimize_minmax_comparison
4353 (build (EQ_EXPR, type, arg0, comp_const)),
4354 optimize_minmax_comparison
4355 (build (GT_EXPR, type, arg0, comp_const))));
4358 if (op_code == MAX_EXPR && consts_equal)
4359 /* MAX (X, 0) == 0 -> X <= 0 */
4360 return fold (build (LE_EXPR, type, inner, comp_const));
4362 else if (op_code == MAX_EXPR && consts_lt)
4363 /* MAX (X, 0) == 5 -> X == 5 */
4364 return fold (build (EQ_EXPR, type, inner, comp_const));
4366 else if (op_code == MAX_EXPR)
4367 /* MAX (X, 0) == -1 -> false */
4368 return omit_one_operand (type, integer_zero_node, inner);
4370 else if (consts_equal)
4371 /* MIN (X, 0) == 0 -> X >= 0 */
4372 return fold (build (GE_EXPR, type, inner, comp_const));
4375 /* MIN (X, 0) == 5 -> false */
4376 return omit_one_operand (type, integer_zero_node, inner);
4379 /* MIN (X, 0) == -1 -> X == -1 */
4380 return fold (build (EQ_EXPR, type, inner, comp_const));
4383 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
4384 /* MAX (X, 0) > 0 -> X > 0
4385 MAX (X, 0) > 5 -> X > 5 */
4386 return fold (build (GT_EXPR, type, inner, comp_const));
4388 else if (op_code == MAX_EXPR)
4389 /* MAX (X, 0) > -1 -> true */
4390 return omit_one_operand (type, integer_one_node, inner);
4392 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
4393 /* MIN (X, 0) > 0 -> false
4394 MIN (X, 0) > 5 -> false */
4395 return omit_one_operand (type, integer_zero_node, inner);
4398 /* MIN (X, 0) > -1 -> X > -1 */
4399 return fold (build (GT_EXPR, type, inner, comp_const));
4406 /* T is an integer expression that is being multiplied, divided, or taken a
4407 modulus (CODE says which and what kind of divide or modulus) by a
4408 constant C. See if we can eliminate that operation by folding it with
4409 other operations already in T. WIDE_TYPE, if non-null, is a type that
4410 should be used for the computation if wider than our type.
4412 For example, if we are dividing (X * 8) + (Y + 16) by 4, we can return
4413 (X * 2) + (Y + 4). We must, however, be assured that either the original
4414 expression would not overflow or that overflow is undefined for the type
4415 in the language in question.
4417 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
4418 the machine has a multiply-accumulate insn or that this is part of an
4419 addressing calculation.
4421 If we return a non-null expression, it is an equivalent form of the
4422 original computation, but need not be in the original type. */
4425 extract_muldiv (t, c, code, wide_type)
4428 enum tree_code code;
4431 tree type = TREE_TYPE (t);
4432 enum tree_code tcode = TREE_CODE (t);
4433 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
4434 > GET_MODE_SIZE (TYPE_MODE (type)))
4435 ? wide_type : type);
4437 int same_p = tcode == code;
4438 tree op0 = NULL_TREE, op1 = NULL_TREE;
4440 /* Don't deal with constants of zero here; they confuse the code below. */
4441 if (integer_zerop (c))
4444 if (TREE_CODE_CLASS (tcode) == '1')
4445 op0 = TREE_OPERAND (t, 0);
4447 if (TREE_CODE_CLASS (tcode) == '2')
4448 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
4450 /* Note that we need not handle conditional operations here since fold
4451 already handles those cases. So just do arithmetic here. */
4455 /* For a constant, we can always simplify if we are a multiply
4456 or (for divide and modulus) if it is a multiple of our constant. */
4457 if (code == MULT_EXPR
4458 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
4459 return const_binop (code, convert (ctype, t), convert (ctype, c), 0);
4462 case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
4463 /* If op0 is an expression, and is unsigned, and the type is
4464 smaller than ctype, then we cannot widen the expression. */
4465 if ((TREE_CODE_CLASS (TREE_CODE (op0)) == '<'
4466 || TREE_CODE_CLASS (TREE_CODE (op0)) == '1'
4467 || TREE_CODE_CLASS (TREE_CODE (op0)) == '2'
4468 || TREE_CODE_CLASS (TREE_CODE (op0)) == 'e')
4469 && TREE_UNSIGNED (TREE_TYPE (op0))
4470 && ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
4471 && TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
4472 && (GET_MODE_SIZE (TYPE_MODE (ctype))
4473 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
4476 /* Pass the constant down and see if we can make a simplification. If
4477 we can, replace this expression with the inner simplification for
4478 possible later conversion to our or some other type. */
4479 if (0 != (t1 = extract_muldiv (op0, convert (TREE_TYPE (op0), c), code,
4480 code == MULT_EXPR ? ctype : NULL_TREE)))
4484 case NEGATE_EXPR: case ABS_EXPR:
4485 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4486 return fold (build1 (tcode, ctype, convert (ctype, t1)));
4489 case MIN_EXPR: case MAX_EXPR:
4490 /* If widening the type changes the signedness, then we can't perform
4491 this optimization as that changes the result. */
4492 if (TREE_UNSIGNED (ctype) != TREE_UNSIGNED (type))
4495 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
4496 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0
4497 && (t2 = extract_muldiv (op1, c, code, wide_type)) != 0)
4499 if (tree_int_cst_sgn (c) < 0)
4500 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
4502 return fold (build (tcode, ctype, convert (ctype, t1),
4503 convert (ctype, t2)));
4507 case WITH_RECORD_EXPR:
4508 if ((t1 = extract_muldiv (TREE_OPERAND (t, 0), c, code, wide_type)) != 0)
4509 return build (WITH_RECORD_EXPR, TREE_TYPE (t1), t1,
4510 TREE_OPERAND (t, 1));
4514 /* If this has not been evaluated and the operand has no side effects,
4515 we can see if we can do something inside it and make a new one.
4516 Note that this test is overly conservative since we can do this
4517 if the only reason it had side effects is that it was another
4518 similar SAVE_EXPR, but that isn't worth bothering with. */
4519 if (SAVE_EXPR_RTL (t) == 0 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0))
4520 && 0 != (t1 = extract_muldiv (TREE_OPERAND (t, 0), c, code,
4523 t1 = save_expr (t1);
4524 if (SAVE_EXPR_PERSISTENT_P (t) && TREE_CODE (t1) == SAVE_EXPR)
4525 SAVE_EXPR_PERSISTENT_P (t1) = 1;
4526 if (is_pending_size (t))
4527 put_pending_size (t1);
4532 case LSHIFT_EXPR: case RSHIFT_EXPR:
4533 /* If the second operand is constant, this is a multiplication
4534 or floor division, by a power of two, so we can treat it that
4535 way unless the multiplier or divisor overflows. */
4536 if (TREE_CODE (op1) == INTEGER_CST
4537 /* const_binop may not detect overflow correctly,
4538 so check for it explicitly here. */
4539 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
4540 && TREE_INT_CST_HIGH (op1) == 0
4541 && 0 != (t1 = convert (ctype,
4542 const_binop (LSHIFT_EXPR, size_one_node,
4544 && ! TREE_OVERFLOW (t1))
4545 return extract_muldiv (build (tcode == LSHIFT_EXPR
4546 ? MULT_EXPR : FLOOR_DIV_EXPR,
4547 ctype, convert (ctype, op0), t1),
4548 c, code, wide_type);
4551 case PLUS_EXPR: case MINUS_EXPR:
4552 /* See if we can eliminate the operation on both sides. If we can, we
4553 can return a new PLUS or MINUS. If we can't, the only remaining
4554 cases where we can do anything are if the second operand is a
4556 t1 = extract_muldiv (op0, c, code, wide_type);
4557 t2 = extract_muldiv (op1, c, code, wide_type);
4558 if (t1 != 0 && t2 != 0
4559 && (code == MULT_EXPR
4560 /* If not multiplication, we can only do this if either operand
4561 is divisible by c. */
4562 || multiple_of_p (ctype, op0, c)
4563 || multiple_of_p (ctype, op1, c)))
4564 return fold (build (tcode, ctype, convert (ctype, t1),
4565 convert (ctype, t2)));
4567 /* If this was a subtraction, negate OP1 and set it to be an addition.
4568 This simplifies the logic below. */
4569 if (tcode == MINUS_EXPR)
4570 tcode = PLUS_EXPR, op1 = negate_expr (op1);
4572 if (TREE_CODE (op1) != INTEGER_CST)
4575 /* If either OP1 or C are negative, this optimization is not safe for
4576 some of the division and remainder types while for others we need
4577 to change the code. */
4578 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
4580 if (code == CEIL_DIV_EXPR)
4581 code = FLOOR_DIV_EXPR;
4582 else if (code == FLOOR_DIV_EXPR)
4583 code = CEIL_DIV_EXPR;
4584 else if (code != MULT_EXPR
4585 && code != CEIL_MOD_EXPR && code != FLOOR_MOD_EXPR)
4589 /* If it's a multiply or a division/modulus operation of a multiple
4590 of our constant, do the operation and verify it doesn't overflow. */
4591 if (code == MULT_EXPR
4592 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4594 op1 = const_binop (code, convert (ctype, op1), convert (ctype, c), 0);
4595 if (op1 == 0 || TREE_OVERFLOW (op1))
4601 /* If we have an unsigned type is not a sizetype, we cannot widen
4602 the operation since it will change the result if the original
4603 computation overflowed. */
4604 if (TREE_UNSIGNED (ctype)
4605 && ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
4609 /* If we were able to eliminate our operation from the first side,
4610 apply our operation to the second side and reform the PLUS. */
4611 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
4612 return fold (build (tcode, ctype, convert (ctype, t1), op1));
4614 /* The last case is if we are a multiply. In that case, we can
4615 apply the distributive law to commute the multiply and addition
4616 if the multiplication of the constants doesn't overflow. */
4617 if (code == MULT_EXPR)
4618 return fold (build (tcode, ctype, fold (build (code, ctype,
4619 convert (ctype, op0),
4620 convert (ctype, c))),
4626 /* We have a special case here if we are doing something like
4627 (C * 8) % 4 since we know that's zero. */
4628 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
4629 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
4630 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
4631 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4632 return omit_one_operand (type, integer_zero_node, op0);
4634 /* ... fall through ... */
4636 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
4637 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
4638 /* If we can extract our operation from the LHS, do so and return a
4639 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
4640 do something only if the second operand is a constant. */
4642 && (t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4643 return fold (build (tcode, ctype, convert (ctype, t1),
4644 convert (ctype, op1)));
4645 else if (tcode == MULT_EXPR && code == MULT_EXPR
4646 && (t1 = extract_muldiv (op1, c, code, wide_type)) != 0)
4647 return fold (build (tcode, ctype, convert (ctype, op0),
4648 convert (ctype, t1)));
4649 else if (TREE_CODE (op1) != INTEGER_CST)
4652 /* If these are the same operation types, we can associate them
4653 assuming no overflow. */
4655 && 0 != (t1 = const_binop (MULT_EXPR, convert (ctype, op1),
4656 convert (ctype, c), 0))
4657 && ! TREE_OVERFLOW (t1))
4658 return fold (build (tcode, ctype, convert (ctype, op0), t1));
4660 /* If these operations "cancel" each other, we have the main
4661 optimizations of this pass, which occur when either constant is a
4662 multiple of the other, in which case we replace this with either an
4663 operation or CODE or TCODE.
4665 If we have an unsigned type that is not a sizetype, we canot do
4666 this since it will change the result if the original computation
4668 if ((! TREE_UNSIGNED (ctype)
4669 || (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
4670 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
4671 || (tcode == MULT_EXPR
4672 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
4673 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR)))
4675 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4676 return fold (build (tcode, ctype, convert (ctype, op0),
4678 const_binop (TRUNC_DIV_EXPR,
4680 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
4681 return fold (build (code, ctype, convert (ctype, op0),
4683 const_binop (TRUNC_DIV_EXPR,
4695 /* If T contains a COMPOUND_EXPR which was inserted merely to evaluate
4696 S, a SAVE_EXPR, return the expression actually being evaluated. Note
4697 that we may sometimes modify the tree. */
4700 strip_compound_expr (t, s)
4704 enum tree_code code = TREE_CODE (t);
4706 /* See if this is the COMPOUND_EXPR we want to eliminate. */
4707 if (code == COMPOUND_EXPR && TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR
4708 && TREE_OPERAND (TREE_OPERAND (t, 0), 0) == s)
4709 return TREE_OPERAND (t, 1);
4711 /* See if this is a COND_EXPR or a simple arithmetic operator. We
4712 don't bother handling any other types. */
4713 else if (code == COND_EXPR)
4715 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4716 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4717 TREE_OPERAND (t, 2) = strip_compound_expr (TREE_OPERAND (t, 2), s);
4719 else if (TREE_CODE_CLASS (code) == '1')
4720 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4721 else if (TREE_CODE_CLASS (code) == '<'
4722 || TREE_CODE_CLASS (code) == '2')
4724 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4725 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4731 /* Return a node which has the indicated constant VALUE (either 0 or
4732 1), and is of the indicated TYPE. */
4735 constant_boolean_node (value, type)
4739 if (type == integer_type_node)
4740 return value ? integer_one_node : integer_zero_node;
4741 else if (TREE_CODE (type) == BOOLEAN_TYPE)
4742 return truthvalue_conversion (value ? integer_one_node :
4746 tree t = build_int_2 (value, 0);
4748 TREE_TYPE (t) = type;
4753 /* Utility function for the following routine, to see how complex a nesting of
4754 COND_EXPRs can be. EXPR is the expression and LIMIT is a count beyond which
4755 we don't care (to avoid spending too much time on complex expressions.). */
4758 count_cond (expr, lim)
4764 if (TREE_CODE (expr) != COND_EXPR)
4769 ctrue = count_cond (TREE_OPERAND (expr, 1), lim - 1);
4770 cfalse = count_cond (TREE_OPERAND (expr, 2), lim - 1 - ctrue);
4771 return MIN (lim, 1 + ctrue + cfalse);
4774 /* Transform `a + (b ? x : y)' into `x ? (a + b) : (a + y)'.
4775 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
4776 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
4777 expression, and ARG to `a'. If COND_FIRST_P is non-zero, then the
4778 COND is the first argument to CODE; otherwise (as in the example
4779 given here), it is the second argument. TYPE is the type of the
4780 original expression. */
4783 fold_binary_op_with_conditional_arg (code, type, cond, arg, cond_first_p)
4784 enum tree_code code;
4790 tree test, true_value, false_value;
4791 tree lhs = NULL_TREE;
4792 tree rhs = NULL_TREE;
4793 /* In the end, we'll produce a COND_EXPR. Both arms of the
4794 conditional expression will be binary operations. The left-hand
4795 side of the expression to be executed if the condition is true
4796 will be pointed to by TRUE_LHS. Similarly, the right-hand side
4797 of the expression to be executed if the condition is true will be
4798 pointed to by TRUE_RHS. FALSE_LHS and FALSE_RHS are analagous --
4799 but apply to the expression to be executed if the conditional is
4805 /* These are the codes to use for the left-hand side and right-hand
4806 side of the COND_EXPR. Normally, they are the same as CODE. */
4807 enum tree_code lhs_code = code;
4808 enum tree_code rhs_code = code;
4809 /* And these are the types of the expressions. */
4810 tree lhs_type = type;
4811 tree rhs_type = type;
4815 true_rhs = false_rhs = &arg;
4816 true_lhs = &true_value;
4817 false_lhs = &false_value;
4821 true_lhs = false_lhs = &arg;
4822 true_rhs = &true_value;
4823 false_rhs = &false_value;
4826 if (TREE_CODE (cond) == COND_EXPR)
4828 test = TREE_OPERAND (cond, 0);
4829 true_value = TREE_OPERAND (cond, 1);
4830 false_value = TREE_OPERAND (cond, 2);
4831 /* If this operand throws an expression, then it does not make
4832 sense to try to perform a logical or arithmetic operation
4833 involving it. Instead of building `a + throw 3' for example,
4834 we simply build `a, throw 3'. */
4835 if (VOID_TYPE_P (TREE_TYPE (true_value)))
4837 lhs_code = COMPOUND_EXPR;
4839 lhs_type = void_type_node;
4841 if (VOID_TYPE_P (TREE_TYPE (false_value)))
4843 rhs_code = COMPOUND_EXPR;
4845 rhs_type = void_type_node;
4850 tree testtype = TREE_TYPE (cond);
4852 true_value = convert (testtype, integer_one_node);
4853 false_value = convert (testtype, integer_zero_node);
4856 /* If ARG is complex we want to make sure we only evaluate
4857 it once. Though this is only required if it is volatile, it
4858 might be more efficient even if it is not. However, if we
4859 succeed in folding one part to a constant, we do not need
4860 to make this SAVE_EXPR. Since we do this optimization
4861 primarily to see if we do end up with constant and this
4862 SAVE_EXPR interferes with later optimizations, suppressing
4863 it when we can is important.
4865 If we are not in a function, we can't make a SAVE_EXPR, so don't
4866 try to do so. Don't try to see if the result is a constant
4867 if an arm is a COND_EXPR since we get exponential behavior
4870 if (TREE_CODE (arg) != SAVE_EXPR && ! TREE_CONSTANT (arg)
4871 && global_bindings_p () == 0
4872 && ((TREE_CODE (arg) != VAR_DECL
4873 && TREE_CODE (arg) != PARM_DECL)
4874 || TREE_SIDE_EFFECTS (arg)))
4876 if (TREE_CODE (true_value) != COND_EXPR)
4877 lhs = fold (build (lhs_code, lhs_type, *true_lhs, *true_rhs));
4879 if (TREE_CODE (false_value) != COND_EXPR)
4880 rhs = fold (build (rhs_code, rhs_type, *false_lhs, *false_rhs));
4882 if ((lhs == 0 || ! TREE_CONSTANT (lhs))
4883 && (rhs == 0 || !TREE_CONSTANT (rhs)))
4884 arg = save_expr (arg), lhs = rhs = 0;
4888 lhs = fold (build (lhs_code, lhs_type, *true_lhs, *true_rhs));
4890 rhs = fold (build (rhs_code, rhs_type, *false_lhs, *false_rhs));
4892 test = fold (build (COND_EXPR, type, test, lhs, rhs));
4894 if (TREE_CODE (arg) == SAVE_EXPR)
4895 return build (COMPOUND_EXPR, type,
4896 convert (void_type_node, arg),
4897 strip_compound_expr (test, arg));
4899 return convert (type, test);
4903 /* Perform constant folding and related simplification of EXPR.
4904 The related simplifications include x*1 => x, x*0 => 0, etc.,
4905 and application of the associative law.
4906 NOP_EXPR conversions may be removed freely (as long as we
4907 are careful not to change the C type of the overall expression)
4908 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
4909 but we can constant-fold them if they have constant operands. */
4916 tree t1 = NULL_TREE;
4918 tree type = TREE_TYPE (expr);
4919 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
4920 enum tree_code code = TREE_CODE (t);
4921 int kind = TREE_CODE_CLASS (code);
4923 /* WINS will be nonzero when the switch is done
4924 if all operands are constant. */
4927 /* Don't try to process an RTL_EXPR since its operands aren't trees.
4928 Likewise for a SAVE_EXPR that's already been evaluated. */
4929 if (code == RTL_EXPR || (code == SAVE_EXPR && SAVE_EXPR_RTL (t) != 0))
4932 /* Return right away if a constant. */
4936 #ifdef MAX_INTEGER_COMPUTATION_MODE
4937 check_max_integer_computation_mode (expr);
4940 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
4944 /* Special case for conversion ops that can have fixed point args. */
4945 arg0 = TREE_OPERAND (t, 0);
4947 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
4949 STRIP_SIGN_NOPS (arg0);
4951 if (arg0 != 0 && TREE_CODE (arg0) == COMPLEX_CST)
4952 subop = TREE_REALPART (arg0);
4956 if (subop != 0 && TREE_CODE (subop) != INTEGER_CST
4957 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
4958 && TREE_CODE (subop) != REAL_CST
4959 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
4961 /* Note that TREE_CONSTANT isn't enough:
4962 static var addresses are constant but we can't
4963 do arithmetic on them. */
4966 else if (IS_EXPR_CODE_CLASS (kind) || kind == 'r')
4968 int len = first_rtl_op (code);
4970 for (i = 0; i < len; i++)
4972 tree op = TREE_OPERAND (t, i);
4976 continue; /* Valid for CALL_EXPR, at least. */
4978 if (kind == '<' || code == RSHIFT_EXPR)
4980 /* Signedness matters here. Perhaps we can refine this
4982 STRIP_SIGN_NOPS (op);
4985 /* Strip any conversions that don't change the mode. */
4988 if (TREE_CODE (op) == COMPLEX_CST)
4989 subop = TREE_REALPART (op);
4993 if (TREE_CODE (subop) != INTEGER_CST
4994 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
4995 && TREE_CODE (subop) != REAL_CST
4996 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
4998 /* Note that TREE_CONSTANT isn't enough:
4999 static var addresses are constant but we can't
5000 do arithmetic on them. */
5010 /* If this is a commutative operation, and ARG0 is a constant, move it
5011 to ARG1 to reduce the number of tests below. */
5012 if ((code == PLUS_EXPR || code == MULT_EXPR || code == MIN_EXPR
5013 || code == MAX_EXPR || code == BIT_IOR_EXPR || code == BIT_XOR_EXPR
5014 || code == BIT_AND_EXPR)
5015 && (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST))
5017 tem = arg0; arg0 = arg1; arg1 = tem;
5019 tem = TREE_OPERAND (t, 0); TREE_OPERAND (t, 0) = TREE_OPERAND (t, 1);
5020 TREE_OPERAND (t, 1) = tem;
5023 /* Now WINS is set as described above,
5024 ARG0 is the first operand of EXPR,
5025 and ARG1 is the second operand (if it has more than one operand).
5027 First check for cases where an arithmetic operation is applied to a
5028 compound, conditional, or comparison operation. Push the arithmetic
5029 operation inside the compound or conditional to see if any folding
5030 can then be done. Convert comparison to conditional for this purpose.
5031 The also optimizes non-constant cases that used to be done in
5034 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
5035 one of the operands is a comparison and the other is a comparison, a
5036 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
5037 code below would make the expression more complex. Change it to a
5038 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
5039 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
5041 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
5042 || code == EQ_EXPR || code == NE_EXPR)
5043 && ((truth_value_p (TREE_CODE (arg0))
5044 && (truth_value_p (TREE_CODE (arg1))
5045 || (TREE_CODE (arg1) == BIT_AND_EXPR
5046 && integer_onep (TREE_OPERAND (arg1, 1)))))
5047 || (truth_value_p (TREE_CODE (arg1))
5048 && (truth_value_p (TREE_CODE (arg0))
5049 || (TREE_CODE (arg0) == BIT_AND_EXPR
5050 && integer_onep (TREE_OPERAND (arg0, 1)))))))
5052 t = fold (build (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
5053 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
5057 if (code == EQ_EXPR)
5058 t = invert_truthvalue (t);
5063 if (TREE_CODE_CLASS (code) == '1')
5065 if (TREE_CODE (arg0) == COMPOUND_EXPR)
5066 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5067 fold (build1 (code, type, TREE_OPERAND (arg0, 1))));
5068 else if (TREE_CODE (arg0) == COND_EXPR)
5070 t = fold (build (COND_EXPR, type, TREE_OPERAND (arg0, 0),
5071 fold (build1 (code, type, TREE_OPERAND (arg0, 1))),
5072 fold (build1 (code, type, TREE_OPERAND (arg0, 2)))));
5074 /* If this was a conversion, and all we did was to move into
5075 inside the COND_EXPR, bring it back out. But leave it if
5076 it is a conversion from integer to integer and the
5077 result precision is no wider than a word since such a
5078 conversion is cheap and may be optimized away by combine,
5079 while it couldn't if it were outside the COND_EXPR. Then return
5080 so we don't get into an infinite recursion loop taking the
5081 conversion out and then back in. */
5083 if ((code == NOP_EXPR || code == CONVERT_EXPR
5084 || code == NON_LVALUE_EXPR)
5085 && TREE_CODE (t) == COND_EXPR
5086 && TREE_CODE (TREE_OPERAND (t, 1)) == code
5087 && TREE_CODE (TREE_OPERAND (t, 2)) == code
5088 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))
5089 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 2), 0)))
5090 && ! (INTEGRAL_TYPE_P (TREE_TYPE (t))
5092 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))))
5093 && TYPE_PRECISION (TREE_TYPE (t)) <= BITS_PER_WORD))
5094 t = build1 (code, type,
5096 TREE_TYPE (TREE_OPERAND
5097 (TREE_OPERAND (t, 1), 0)),
5098 TREE_OPERAND (t, 0),
5099 TREE_OPERAND (TREE_OPERAND (t, 1), 0),
5100 TREE_OPERAND (TREE_OPERAND (t, 2), 0)));
5103 else if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<')
5104 return fold (build (COND_EXPR, type, arg0,
5105 fold (build1 (code, type, integer_one_node)),
5106 fold (build1 (code, type, integer_zero_node))));
5108 else if (TREE_CODE_CLASS (code) == '2'
5109 || TREE_CODE_CLASS (code) == '<')
5111 if (TREE_CODE (arg1) == COMPOUND_EXPR)
5112 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
5113 fold (build (code, type,
5114 arg0, TREE_OPERAND (arg1, 1))));
5115 else if ((TREE_CODE (arg1) == COND_EXPR
5116 || (TREE_CODE_CLASS (TREE_CODE (arg1)) == '<'
5117 && TREE_CODE_CLASS (code) != '<'))
5118 && (TREE_CODE (arg0) != COND_EXPR
5119 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
5120 && (! TREE_SIDE_EFFECTS (arg0)
5121 || (global_bindings_p () == 0
5122 && ! contains_placeholder_p (arg0))))
5124 fold_binary_op_with_conditional_arg (code, type, arg1, arg0,
5125 /*cond_first_p=*/0);
5126 else if (TREE_CODE (arg0) == COMPOUND_EXPR)
5127 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5128 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
5129 else if ((TREE_CODE (arg0) == COND_EXPR
5130 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
5131 && TREE_CODE_CLASS (code) != '<'))
5132 && (TREE_CODE (arg1) != COND_EXPR
5133 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
5134 && (! TREE_SIDE_EFFECTS (arg1)
5135 || (global_bindings_p () == 0
5136 && ! contains_placeholder_p (arg1))))
5138 fold_binary_op_with_conditional_arg (code, type, arg0, arg1,
5139 /*cond_first_p=*/1);
5141 else if (TREE_CODE_CLASS (code) == '<'
5142 && TREE_CODE (arg0) == COMPOUND_EXPR)
5143 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5144 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
5145 else if (TREE_CODE_CLASS (code) == '<'
5146 && TREE_CODE (arg1) == COMPOUND_EXPR)
5147 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
5148 fold (build (code, type, arg0, TREE_OPERAND (arg1, 1))));
5160 return fold (DECL_INITIAL (t));
5165 case FIX_TRUNC_EXPR:
5166 /* Other kinds of FIX are not handled properly by fold_convert. */
5168 if (TREE_TYPE (TREE_OPERAND (t, 0)) == TREE_TYPE (t))
5169 return TREE_OPERAND (t, 0);
5171 /* Handle cases of two conversions in a row. */
5172 if (TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
5173 || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR)
5175 tree inside_type = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5176 tree inter_type = TREE_TYPE (TREE_OPERAND (t, 0));
5177 tree final_type = TREE_TYPE (t);
5178 int inside_int = INTEGRAL_TYPE_P (inside_type);
5179 int inside_ptr = POINTER_TYPE_P (inside_type);
5180 int inside_float = FLOAT_TYPE_P (inside_type);
5181 unsigned int inside_prec = TYPE_PRECISION (inside_type);
5182 int inside_unsignedp = TREE_UNSIGNED (inside_type);
5183 int inter_int = INTEGRAL_TYPE_P (inter_type);
5184 int inter_ptr = POINTER_TYPE_P (inter_type);
5185 int inter_float = FLOAT_TYPE_P (inter_type);
5186 unsigned int inter_prec = TYPE_PRECISION (inter_type);
5187 int inter_unsignedp = TREE_UNSIGNED (inter_type);
5188 int final_int = INTEGRAL_TYPE_P (final_type);
5189 int final_ptr = POINTER_TYPE_P (final_type);
5190 int final_float = FLOAT_TYPE_P (final_type);
5191 unsigned int final_prec = TYPE_PRECISION (final_type);
5192 int final_unsignedp = TREE_UNSIGNED (final_type);
5194 /* In addition to the cases of two conversions in a row
5195 handled below, if we are converting something to its own
5196 type via an object of identical or wider precision, neither
5197 conversion is needed. */
5198 if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (final_type)
5199 && ((inter_int && final_int) || (inter_float && final_float))
5200 && inter_prec >= final_prec)
5201 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5203 /* Likewise, if the intermediate and final types are either both
5204 float or both integer, we don't need the middle conversion if
5205 it is wider than the final type and doesn't change the signedness
5206 (for integers). Avoid this if the final type is a pointer
5207 since then we sometimes need the inner conversion. Likewise if
5208 the outer has a precision not equal to the size of its mode. */
5209 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
5210 || (inter_float && inside_float))
5211 && inter_prec >= inside_prec
5212 && (inter_float || inter_unsignedp == inside_unsignedp)
5213 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
5214 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
5216 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5218 /* If we have a sign-extension of a zero-extended value, we can
5219 replace that by a single zero-extension. */
5220 if (inside_int && inter_int && final_int
5221 && inside_prec < inter_prec && inter_prec < final_prec
5222 && inside_unsignedp && !inter_unsignedp)
5223 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5225 /* Two conversions in a row are not needed unless:
5226 - some conversion is floating-point (overstrict for now), or
5227 - the intermediate type is narrower than both initial and
5229 - the intermediate type and innermost type differ in signedness,
5230 and the outermost type is wider than the intermediate, or
5231 - the initial type is a pointer type and the precisions of the
5232 intermediate and final types differ, or
5233 - the final type is a pointer type and the precisions of the
5234 initial and intermediate types differ. */
5235 if (! inside_float && ! inter_float && ! final_float
5236 && (inter_prec > inside_prec || inter_prec > final_prec)
5237 && ! (inside_int && inter_int
5238 && inter_unsignedp != inside_unsignedp
5239 && inter_prec < final_prec)
5240 && ((inter_unsignedp && inter_prec > inside_prec)
5241 == (final_unsignedp && final_prec > inter_prec))
5242 && ! (inside_ptr && inter_prec != final_prec)
5243 && ! (final_ptr && inside_prec != inter_prec)
5244 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
5245 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
5247 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5250 if (TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR
5251 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t, 0), 1))
5252 /* Detect assigning a bitfield. */
5253 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) == COMPONENT_REF
5254 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 1))))
5256 /* Don't leave an assignment inside a conversion
5257 unless assigning a bitfield. */
5258 tree prev = TREE_OPERAND (t, 0);
5259 TREE_OPERAND (t, 0) = TREE_OPERAND (prev, 1);
5260 /* First do the assignment, then return converted constant. */
5261 t = build (COMPOUND_EXPR, TREE_TYPE (t), prev, fold (t));
5267 TREE_CONSTANT (t) = TREE_CONSTANT (arg0);
5270 return fold_convert (t, arg0);
5272 #if 0 /* This loses on &"foo"[0]. */
5277 /* Fold an expression like: "foo"[2] */
5278 if (TREE_CODE (arg0) == STRING_CST
5279 && TREE_CODE (arg1) == INTEGER_CST
5280 && compare_tree_int (arg1, TREE_STRING_LENGTH (arg0)) < 0)
5282 t = build_int_2 (TREE_STRING_POINTER (arg0)[TREE_INT_CST_LOW (arg))], 0);
5283 TREE_TYPE (t) = TREE_TYPE (TREE_TYPE (arg0));
5284 force_fit_type (t, 0);
5291 if (TREE_CODE (arg0) == CONSTRUCTOR)
5293 tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0));
5300 TREE_CONSTANT (t) = wins;
5306 if (TREE_CODE (arg0) == INTEGER_CST)
5308 unsigned HOST_WIDE_INT low;
5310 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
5311 TREE_INT_CST_HIGH (arg0),
5313 t = build_int_2 (low, high);
5314 TREE_TYPE (t) = type;
5316 = (TREE_OVERFLOW (arg0)
5317 | force_fit_type (t, overflow && !TREE_UNSIGNED (type)));
5318 TREE_CONSTANT_OVERFLOW (t)
5319 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
5321 else if (TREE_CODE (arg0) == REAL_CST)
5322 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
5324 else if (TREE_CODE (arg0) == NEGATE_EXPR)
5325 return TREE_OPERAND (arg0, 0);
5327 /* Convert - (a - b) to (b - a) for non-floating-point. */
5328 else if (TREE_CODE (arg0) == MINUS_EXPR
5329 && (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
5330 return build (MINUS_EXPR, type, TREE_OPERAND (arg0, 1),
5331 TREE_OPERAND (arg0, 0));
5338 if (TREE_CODE (arg0) == INTEGER_CST)
5340 /* If the value is unsigned, then the absolute value is
5341 the same as the ordinary value. */
5342 if (TREE_UNSIGNED (type))
5344 /* Similarly, if the value is non-negative. */
5345 else if (INT_CST_LT (integer_minus_one_node, arg0))
5347 /* If the value is negative, then the absolute value is
5351 unsigned HOST_WIDE_INT low;
5353 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
5354 TREE_INT_CST_HIGH (arg0),
5356 t = build_int_2 (low, high);
5357 TREE_TYPE (t) = type;
5359 = (TREE_OVERFLOW (arg0)
5360 | force_fit_type (t, overflow));
5361 TREE_CONSTANT_OVERFLOW (t)
5362 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
5365 else if (TREE_CODE (arg0) == REAL_CST)
5367 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
5368 t = build_real (type,
5369 REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
5372 else if (TREE_CODE (arg0) == ABS_EXPR || TREE_CODE (arg0) == NEGATE_EXPR)
5373 return build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0));
5377 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
5378 return convert (type, arg0);
5379 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
5380 return build (COMPLEX_EXPR, type,
5381 TREE_OPERAND (arg0, 0),
5382 negate_expr (TREE_OPERAND (arg0, 1)));
5383 else if (TREE_CODE (arg0) == COMPLEX_CST)
5384 return build_complex (type, TREE_REALPART (arg0),
5385 negate_expr (TREE_IMAGPART (arg0)));
5386 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
5387 return fold (build (TREE_CODE (arg0), type,
5388 fold (build1 (CONJ_EXPR, type,
5389 TREE_OPERAND (arg0, 0))),
5390 fold (build1 (CONJ_EXPR,
5391 type, TREE_OPERAND (arg0, 1)))));
5392 else if (TREE_CODE (arg0) == CONJ_EXPR)
5393 return TREE_OPERAND (arg0, 0);
5399 t = build_int_2 (~ TREE_INT_CST_LOW (arg0),
5400 ~ TREE_INT_CST_HIGH (arg0));
5401 TREE_TYPE (t) = type;
5402 force_fit_type (t, 0);
5403 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg0);
5404 TREE_CONSTANT_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (arg0);
5406 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
5407 return TREE_OPERAND (arg0, 0);
5411 /* A + (-B) -> A - B */
5412 if (TREE_CODE (arg1) == NEGATE_EXPR)
5413 return fold (build (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5414 /* (-A) + B -> B - A */
5415 if (TREE_CODE (arg0) == NEGATE_EXPR)
5416 return fold (build (MINUS_EXPR, type, arg1, TREE_OPERAND (arg0, 0)));
5417 else if (! FLOAT_TYPE_P (type))
5419 if (integer_zerop (arg1))
5420 return non_lvalue (convert (type, arg0));
5422 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
5423 with a constant, and the two constants have no bits in common,
5424 we should treat this as a BIT_IOR_EXPR since this may produce more
5426 if (TREE_CODE (arg0) == BIT_AND_EXPR
5427 && TREE_CODE (arg1) == BIT_AND_EXPR
5428 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5429 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
5430 && integer_zerop (const_binop (BIT_AND_EXPR,
5431 TREE_OPERAND (arg0, 1),
5432 TREE_OPERAND (arg1, 1), 0)))
5434 code = BIT_IOR_EXPR;
5438 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
5439 (plus (plus (mult) (mult)) (foo)) so that we can
5440 take advantage of the factoring cases below. */
5441 if ((TREE_CODE (arg0) == PLUS_EXPR
5442 && TREE_CODE (arg1) == MULT_EXPR)
5443 || (TREE_CODE (arg1) == PLUS_EXPR
5444 && TREE_CODE (arg0) == MULT_EXPR))
5446 tree parg0, parg1, parg, marg;
5448 if (TREE_CODE (arg0) == PLUS_EXPR)
5449 parg = arg0, marg = arg1;
5451 parg = arg1, marg = arg0;
5452 parg0 = TREE_OPERAND (parg, 0);
5453 parg1 = TREE_OPERAND (parg, 1);
5457 if (TREE_CODE (parg0) == MULT_EXPR
5458 && TREE_CODE (parg1) != MULT_EXPR)
5459 return fold (build (PLUS_EXPR, type,
5460 fold (build (PLUS_EXPR, type, parg0, marg)),
5462 if (TREE_CODE (parg0) != MULT_EXPR
5463 && TREE_CODE (parg1) == MULT_EXPR)
5464 return fold (build (PLUS_EXPR, type,
5465 fold (build (PLUS_EXPR, type, parg1, marg)),
5469 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR)
5471 tree arg00, arg01, arg10, arg11;
5472 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
5474 /* (A * C) + (B * C) -> (A+B) * C.
5475 We are most concerned about the case where C is a constant,
5476 but other combinations show up during loop reduction. Since
5477 it is not difficult, try all four possibilities. */
5479 arg00 = TREE_OPERAND (arg0, 0);
5480 arg01 = TREE_OPERAND (arg0, 1);
5481 arg10 = TREE_OPERAND (arg1, 0);
5482 arg11 = TREE_OPERAND (arg1, 1);
5485 if (operand_equal_p (arg01, arg11, 0))
5486 same = arg01, alt0 = arg00, alt1 = arg10;
5487 else if (operand_equal_p (arg00, arg10, 0))
5488 same = arg00, alt0 = arg01, alt1 = arg11;
5489 else if (operand_equal_p (arg00, arg11, 0))
5490 same = arg00, alt0 = arg01, alt1 = arg10;
5491 else if (operand_equal_p (arg01, arg10, 0))
5492 same = arg01, alt0 = arg00, alt1 = arg11;
5494 /* No identical multiplicands; see if we can find a common
5495 power-of-two factor in non-power-of-two multiplies. This
5496 can help in multi-dimensional array access. */
5497 else if (TREE_CODE (arg01) == INTEGER_CST
5498 && TREE_CODE (arg11) == INTEGER_CST
5499 && TREE_INT_CST_HIGH (arg01) == 0
5500 && TREE_INT_CST_HIGH (arg11) == 0)
5502 HOST_WIDE_INT int01, int11, tmp;
5503 int01 = TREE_INT_CST_LOW (arg01);
5504 int11 = TREE_INT_CST_LOW (arg11);
5506 /* Move min of absolute values to int11. */
5507 if ((int01 >= 0 ? int01 : -int01)
5508 < (int11 >= 0 ? int11 : -int11))
5510 tmp = int01, int01 = int11, int11 = tmp;
5511 alt0 = arg00, arg00 = arg10, arg10 = alt0;
5512 alt0 = arg01, arg01 = arg11, arg11 = alt0;
5515 if (exact_log2 (int11) > 0 && int01 % int11 == 0)
5517 alt0 = fold (build (MULT_EXPR, type, arg00,
5518 build_int_2 (int01 / int11, 0)));
5525 return fold (build (MULT_EXPR, type,
5526 fold (build (PLUS_EXPR, type, alt0, alt1)),
5530 /* In IEEE floating point, x+0 may not equal x. */
5531 else if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
5532 || flag_unsafe_math_optimizations)
5533 && real_zerop (arg1))
5534 return non_lvalue (convert (type, arg0));
5535 /* x+(-0) equals x, even for IEEE. */
5536 else if (TREE_CODE (arg1) == REAL_CST
5537 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (arg1)))
5538 return non_lvalue (convert (type, arg0));
5541 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
5542 is a rotate of A by C1 bits. */
5543 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
5544 is a rotate of A by B bits. */
5546 enum tree_code code0, code1;
5547 code0 = TREE_CODE (arg0);
5548 code1 = TREE_CODE (arg1);
5549 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
5550 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
5551 && operand_equal_p (TREE_OPERAND (arg0, 0),
5552 TREE_OPERAND (arg1, 0), 0)
5553 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5555 tree tree01, tree11;
5556 enum tree_code code01, code11;
5558 tree01 = TREE_OPERAND (arg0, 1);
5559 tree11 = TREE_OPERAND (arg1, 1);
5560 STRIP_NOPS (tree01);
5561 STRIP_NOPS (tree11);
5562 code01 = TREE_CODE (tree01);
5563 code11 = TREE_CODE (tree11);
5564 if (code01 == INTEGER_CST
5565 && code11 == INTEGER_CST
5566 && TREE_INT_CST_HIGH (tree01) == 0
5567 && TREE_INT_CST_HIGH (tree11) == 0
5568 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
5569 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
5570 return build (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
5571 code0 == LSHIFT_EXPR ? tree01 : tree11);
5572 else if (code11 == MINUS_EXPR)
5574 tree tree110, tree111;
5575 tree110 = TREE_OPERAND (tree11, 0);
5576 tree111 = TREE_OPERAND (tree11, 1);
5577 STRIP_NOPS (tree110);
5578 STRIP_NOPS (tree111);
5579 if (TREE_CODE (tree110) == INTEGER_CST
5580 && 0 == compare_tree_int (tree110,
5582 (TREE_TYPE (TREE_OPERAND
5584 && operand_equal_p (tree01, tree111, 0))
5585 return build ((code0 == LSHIFT_EXPR
5588 type, TREE_OPERAND (arg0, 0), tree01);
5590 else if (code01 == MINUS_EXPR)
5592 tree tree010, tree011;
5593 tree010 = TREE_OPERAND (tree01, 0);
5594 tree011 = TREE_OPERAND (tree01, 1);
5595 STRIP_NOPS (tree010);
5596 STRIP_NOPS (tree011);
5597 if (TREE_CODE (tree010) == INTEGER_CST
5598 && 0 == compare_tree_int (tree010,
5600 (TREE_TYPE (TREE_OPERAND
5602 && operand_equal_p (tree11, tree011, 0))
5603 return build ((code0 != LSHIFT_EXPR
5606 type, TREE_OPERAND (arg0, 0), tree11);
5612 /* In most languages, can't associate operations on floats through
5613 parentheses. Rather than remember where the parentheses were, we
5614 don't associate floats at all. It shouldn't matter much. However,
5615 associating multiplications is only very slightly inaccurate, so do
5616 that if -funsafe-math-optimizations is specified. */
5619 && (! FLOAT_TYPE_P (type)
5620 || (flag_unsafe_math_optimizations && code == MULT_EXPR)))
5622 tree var0, con0, lit0, var1, con1, lit1;
5624 /* Split both trees into variables, constants, and literals. Then
5625 associate each group together, the constants with literals,
5626 then the result with variables. This increases the chances of
5627 literals being recombined later and of generating relocatable
5628 expressions for the sum of a constant and literal. */
5629 var0 = split_tree (arg0, code, &con0, &lit0, 0);
5630 var1 = split_tree (arg1, code, &con1, &lit1, code == MINUS_EXPR);
5632 /* Only do something if we found more than two objects. Otherwise,
5633 nothing has changed and we risk infinite recursion. */
5634 if (2 < ((var0 != 0) + (var1 != 0) + (con0 != 0) + (con1 != 0)
5635 + (lit0 != 0) + (lit1 != 0)))
5637 var0 = associate_trees (var0, var1, code, type);
5638 con0 = associate_trees (con0, con1, code, type);
5639 lit0 = associate_trees (lit0, lit1, code, type);
5640 con0 = associate_trees (con0, lit0, code, type);
5641 return convert (type, associate_trees (var0, con0, code, type));
5646 #if defined (REAL_IS_NOT_DOUBLE) && ! defined (REAL_ARITHMETIC)
5647 if (TREE_CODE (arg1) == REAL_CST)
5649 #endif /* REAL_IS_NOT_DOUBLE, and no REAL_ARITHMETIC */
5651 t1 = const_binop (code, arg0, arg1, 0);
5652 if (t1 != NULL_TREE)
5654 /* The return value should always have
5655 the same type as the original expression. */
5656 if (TREE_TYPE (t1) != TREE_TYPE (t))
5657 t1 = convert (TREE_TYPE (t), t1);
5664 /* A - (-B) -> A + B */
5665 if (TREE_CODE (arg1) == NEGATE_EXPR)
5666 return fold (build (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5667 /* (-A) - CST -> (-CST) - A for floating point (what about ints ?) */
5668 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == REAL_CST)
5670 fold (build (MINUS_EXPR, type,
5671 build_real (TREE_TYPE (arg1),
5672 REAL_VALUE_NEGATE (TREE_REAL_CST (arg1))),
5673 TREE_OPERAND (arg0, 0)));
5675 if (! FLOAT_TYPE_P (type))
5677 if (! wins && integer_zerop (arg0))
5678 return negate_expr (convert (type, arg1));
5679 if (integer_zerop (arg1))
5680 return non_lvalue (convert (type, arg0));
5682 /* (A * C) - (B * C) -> (A-B) * C. Since we are most concerned
5683 about the case where C is a constant, just try one of the
5684 four possibilities. */
5686 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR
5687 && operand_equal_p (TREE_OPERAND (arg0, 1),
5688 TREE_OPERAND (arg1, 1), 0))
5689 return fold (build (MULT_EXPR, type,
5690 fold (build (MINUS_EXPR, type,
5691 TREE_OPERAND (arg0, 0),
5692 TREE_OPERAND (arg1, 0))),
5693 TREE_OPERAND (arg0, 1)));
5696 else if (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
5697 || flag_unsafe_math_optimizations)
5699 /* Except with IEEE floating point, 0-x equals -x. */
5700 if (! wins && real_zerop (arg0))
5701 return negate_expr (convert (type, arg1));
5702 /* Except with IEEE floating point, x-0 equals x. */
5703 if (real_zerop (arg1))
5704 return non_lvalue (convert (type, arg0));
5707 /* Fold &x - &x. This can happen from &x.foo - &x.
5708 This is unsafe for certain floats even in non-IEEE formats.
5709 In IEEE, it is unsafe because it does wrong for NaNs.
5710 Also note that operand_equal_p is always false if an operand
5713 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
5714 && operand_equal_p (arg0, arg1, 0))
5715 return convert (type, integer_zero_node);
5720 /* (-A) * (-B) -> A * B */
5721 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR)
5722 return fold (build (MULT_EXPR, type, TREE_OPERAND (arg0, 0),
5723 TREE_OPERAND (arg1, 0)));
5725 if (! FLOAT_TYPE_P (type))
5727 if (integer_zerop (arg1))
5728 return omit_one_operand (type, arg1, arg0);
5729 if (integer_onep (arg1))
5730 return non_lvalue (convert (type, arg0));
5732 /* (a * (1 << b)) is (a << b) */
5733 if (TREE_CODE (arg1) == LSHIFT_EXPR
5734 && integer_onep (TREE_OPERAND (arg1, 0)))
5735 return fold (build (LSHIFT_EXPR, type, arg0,
5736 TREE_OPERAND (arg1, 1)));
5737 if (TREE_CODE (arg0) == LSHIFT_EXPR
5738 && integer_onep (TREE_OPERAND (arg0, 0)))
5739 return fold (build (LSHIFT_EXPR, type, arg1,
5740 TREE_OPERAND (arg0, 1)));
5742 if (TREE_CODE (arg1) == INTEGER_CST
5743 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
5745 return convert (type, tem);
5750 /* x*0 is 0, except for IEEE floating point. */
5751 if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
5752 || flag_unsafe_math_optimizations)
5753 && real_zerop (arg1))
5754 return omit_one_operand (type, arg1, arg0);
5755 /* In IEEE floating point, x*1 is not equivalent to x for snans.
5756 However, ANSI says we can drop signals,
5757 so we can do this anyway. */
5758 if (real_onep (arg1))
5759 return non_lvalue (convert (type, arg0));
5761 if (! wins && real_twop (arg1) && global_bindings_p () == 0
5762 && ! contains_placeholder_p (arg0))
5764 tree arg = save_expr (arg0);
5765 return build (PLUS_EXPR, type, arg, arg);
5772 if (integer_all_onesp (arg1))
5773 return omit_one_operand (type, arg1, arg0);
5774 if (integer_zerop (arg1))
5775 return non_lvalue (convert (type, arg0));
5776 t1 = distribute_bit_expr (code, type, arg0, arg1);
5777 if (t1 != NULL_TREE)
5780 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
5782 This results in more efficient code for machines without a NAND
5783 instruction. Combine will canonicalize to the first form
5784 which will allow use of NAND instructions provided by the
5785 backend if they exist. */
5786 if (TREE_CODE (arg0) == BIT_NOT_EXPR
5787 && TREE_CODE (arg1) == BIT_NOT_EXPR)
5789 return fold (build1 (BIT_NOT_EXPR, type,
5790 build (BIT_AND_EXPR, type,
5791 TREE_OPERAND (arg0, 0),
5792 TREE_OPERAND (arg1, 0))));
5795 /* See if this can be simplified into a rotate first. If that
5796 is unsuccessful continue in the association code. */
5800 if (integer_zerop (arg1))
5801 return non_lvalue (convert (type, arg0));
5802 if (integer_all_onesp (arg1))
5803 return fold (build1 (BIT_NOT_EXPR, type, arg0));
5805 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
5806 with a constant, and the two constants have no bits in common,
5807 we should treat this as a BIT_IOR_EXPR since this may produce more
5809 if (TREE_CODE (arg0) == BIT_AND_EXPR
5810 && TREE_CODE (arg1) == BIT_AND_EXPR
5811 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5812 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
5813 && integer_zerop (const_binop (BIT_AND_EXPR,
5814 TREE_OPERAND (arg0, 1),
5815 TREE_OPERAND (arg1, 1), 0)))
5817 code = BIT_IOR_EXPR;
5821 /* See if this can be simplified into a rotate first. If that
5822 is unsuccessful continue in the association code. */
5827 if (integer_all_onesp (arg1))
5828 return non_lvalue (convert (type, arg0));
5829 if (integer_zerop (arg1))
5830 return omit_one_operand (type, arg1, arg0);
5831 t1 = distribute_bit_expr (code, type, arg0, arg1);
5832 if (t1 != NULL_TREE)
5834 /* Simplify ((int)c & 0x377) into (int)c, if c is unsigned char. */
5835 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == NOP_EXPR
5836 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg1, 0))))
5839 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg1, 0)));
5841 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
5842 && (~TREE_INT_CST_LOW (arg0)
5843 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
5844 return build1 (NOP_EXPR, type, TREE_OPERAND (arg1, 0));
5846 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
5847 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5850 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
5852 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
5853 && (~TREE_INT_CST_LOW (arg1)
5854 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
5855 return build1 (NOP_EXPR, type, TREE_OPERAND (arg0, 0));
5858 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
5860 This results in more efficient code for machines without a NOR
5861 instruction. Combine will canonicalize to the first form
5862 which will allow use of NOR instructions provided by the
5863 backend if they exist. */
5864 if (TREE_CODE (arg0) == BIT_NOT_EXPR
5865 && TREE_CODE (arg1) == BIT_NOT_EXPR)
5867 return fold (build1 (BIT_NOT_EXPR, type,
5868 build (BIT_IOR_EXPR, type,
5869 TREE_OPERAND (arg0, 0),
5870 TREE_OPERAND (arg1, 0))));
5875 case BIT_ANDTC_EXPR:
5876 if (integer_all_onesp (arg0))
5877 return non_lvalue (convert (type, arg1));
5878 if (integer_zerop (arg0))
5879 return omit_one_operand (type, arg0, arg1);
5880 if (TREE_CODE (arg1) == INTEGER_CST)
5882 arg1 = fold (build1 (BIT_NOT_EXPR, type, arg1));
5883 code = BIT_AND_EXPR;
5889 /* In most cases, do nothing with a divide by zero. */
5890 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
5891 #ifndef REAL_INFINITY
5892 if (TREE_CODE (arg1) == REAL_CST && real_zerop (arg1))
5895 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
5897 /* (-A) / (-B) -> A / B */
5898 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR)
5899 return fold (build (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
5900 TREE_OPERAND (arg1, 0)));
5902 /* In IEEE floating point, x/1 is not equivalent to x for snans.
5903 However, ANSI says we can drop signals, so we can do this anyway. */
5904 if (real_onep (arg1))
5905 return non_lvalue (convert (type, arg0));
5907 /* If ARG1 is a constant, we can convert this to a multiply by the
5908 reciprocal. This does not have the same rounding properties,
5909 so only do this if -funsafe-math-optimizations. We can actually
5910 always safely do it if ARG1 is a power of two, but it's hard to
5911 tell if it is or not in a portable manner. */
5912 if (TREE_CODE (arg1) == REAL_CST)
5914 if (flag_unsafe_math_optimizations
5915 && 0 != (tem = const_binop (code, build_real (type, dconst1),
5917 return fold (build (MULT_EXPR, type, arg0, tem));
5918 /* Find the reciprocal if optimizing and the result is exact. */
5922 r = TREE_REAL_CST (arg1);
5923 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
5925 tem = build_real (type, r);
5926 return fold (build (MULT_EXPR, type, arg0, tem));
5930 /* Convert A/B/C to A/(B*C). */
5931 if (flag_unsafe_math_optimizations
5932 && TREE_CODE (arg0) == RDIV_EXPR)
5934 return fold (build (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
5935 build (MULT_EXPR, type, TREE_OPERAND (arg0, 1),
5938 /* Convert A/(B/C) to (A/B)*C. */
5939 if (flag_unsafe_math_optimizations
5940 && TREE_CODE (arg1) == RDIV_EXPR)
5942 return fold (build (MULT_EXPR, type,
5943 build (RDIV_EXPR, type, arg0,
5944 TREE_OPERAND (arg1, 0)),
5945 TREE_OPERAND (arg1, 1)));
5949 case TRUNC_DIV_EXPR:
5950 case ROUND_DIV_EXPR:
5951 case FLOOR_DIV_EXPR:
5953 case EXACT_DIV_EXPR:
5954 if (integer_onep (arg1))
5955 return non_lvalue (convert (type, arg0));
5956 if (integer_zerop (arg1))
5959 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
5960 operation, EXACT_DIV_EXPR.
5962 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
5963 At one time others generated faster code, it's not clear if they do
5964 after the last round to changes to the DIV code in expmed.c. */
5965 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
5966 && multiple_of_p (type, arg0, arg1))
5967 return fold (build (EXACT_DIV_EXPR, type, arg0, arg1));
5969 if (TREE_CODE (arg1) == INTEGER_CST
5970 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
5972 return convert (type, tem);
5977 case FLOOR_MOD_EXPR:
5978 case ROUND_MOD_EXPR:
5979 case TRUNC_MOD_EXPR:
5980 if (integer_onep (arg1))
5981 return omit_one_operand (type, integer_zero_node, arg0);
5982 if (integer_zerop (arg1))
5985 if (TREE_CODE (arg1) == INTEGER_CST
5986 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
5988 return convert (type, tem);
5996 if (integer_zerop (arg1))
5997 return non_lvalue (convert (type, arg0));
5998 /* Since negative shift count is not well-defined,
5999 don't try to compute it in the compiler. */
6000 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
6002 /* Rewrite an LROTATE_EXPR by a constant into an
6003 RROTATE_EXPR by a new constant. */
6004 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
6006 TREE_SET_CODE (t, RROTATE_EXPR);
6007 code = RROTATE_EXPR;
6008 TREE_OPERAND (t, 1) = arg1
6011 convert (TREE_TYPE (arg1),
6012 build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type)), 0)),
6014 if (tree_int_cst_sgn (arg1) < 0)
6018 /* If we have a rotate of a bit operation with the rotate count and
6019 the second operand of the bit operation both constant,
6020 permute the two operations. */
6021 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
6022 && (TREE_CODE (arg0) == BIT_AND_EXPR
6023 || TREE_CODE (arg0) == BIT_ANDTC_EXPR
6024 || TREE_CODE (arg0) == BIT_IOR_EXPR
6025 || TREE_CODE (arg0) == BIT_XOR_EXPR)
6026 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
6027 return fold (build (TREE_CODE (arg0), type,
6028 fold (build (code, type,
6029 TREE_OPERAND (arg0, 0), arg1)),
6030 fold (build (code, type,
6031 TREE_OPERAND (arg0, 1), arg1))));
6033 /* Two consecutive rotates adding up to the width of the mode can
6035 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
6036 && TREE_CODE (arg0) == RROTATE_EXPR
6037 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6038 && TREE_INT_CST_HIGH (arg1) == 0
6039 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
6040 && ((TREE_INT_CST_LOW (arg1)
6041 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
6042 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type))))
6043 return TREE_OPERAND (arg0, 0);
6048 if (operand_equal_p (arg0, arg1, 0))
6049 return omit_one_operand (type, arg0, arg1);
6050 if (INTEGRAL_TYPE_P (type)
6051 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), 1))
6052 return omit_one_operand (type, arg1, arg0);
6056 if (operand_equal_p (arg0, arg1, 0))
6057 return omit_one_operand (type, arg0, arg1);
6058 if (INTEGRAL_TYPE_P (type)
6059 && TYPE_MAX_VALUE (type)
6060 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), 1))
6061 return omit_one_operand (type, arg1, arg0);
6064 case TRUTH_NOT_EXPR:
6065 /* Note that the operand of this must be an int
6066 and its values must be 0 or 1.
6067 ("true" is a fixed value perhaps depending on the language,
6068 but we don't handle values other than 1 correctly yet.) */
6069 tem = invert_truthvalue (arg0);
6070 /* Avoid infinite recursion. */
6071 if (TREE_CODE (tem) == TRUTH_NOT_EXPR)
6073 return convert (type, tem);
6075 case TRUTH_ANDIF_EXPR:
6076 /* Note that the operands of this must be ints
6077 and their values must be 0 or 1.
6078 ("true" is a fixed value perhaps depending on the language.) */
6079 /* If first arg is constant zero, return it. */
6080 if (integer_zerop (arg0))
6081 return convert (type, arg0);
6082 case TRUTH_AND_EXPR:
6083 /* If either arg is constant true, drop it. */
6084 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
6085 return non_lvalue (convert (type, arg1));
6086 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
6087 /* Preserve sequence points. */
6088 && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
6089 return non_lvalue (convert (type, arg0));
6090 /* If second arg is constant zero, result is zero, but first arg
6091 must be evaluated. */
6092 if (integer_zerop (arg1))
6093 return omit_one_operand (type, arg1, arg0);
6094 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
6095 case will be handled here. */
6096 if (integer_zerop (arg0))
6097 return omit_one_operand (type, arg0, arg1);
6100 /* We only do these simplifications if we are optimizing. */
6104 /* Check for things like (A || B) && (A || C). We can convert this
6105 to A || (B && C). Note that either operator can be any of the four
6106 truth and/or operations and the transformation will still be
6107 valid. Also note that we only care about order for the
6108 ANDIF and ORIF operators. If B contains side effects, this
6109 might change the truth-value of A. */
6110 if (TREE_CODE (arg0) == TREE_CODE (arg1)
6111 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
6112 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
6113 || TREE_CODE (arg0) == TRUTH_AND_EXPR
6114 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
6115 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
6117 tree a00 = TREE_OPERAND (arg0, 0);
6118 tree a01 = TREE_OPERAND (arg0, 1);
6119 tree a10 = TREE_OPERAND (arg1, 0);
6120 tree a11 = TREE_OPERAND (arg1, 1);
6121 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
6122 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
6123 && (code == TRUTH_AND_EXPR
6124 || code == TRUTH_OR_EXPR));
6126 if (operand_equal_p (a00, a10, 0))
6127 return fold (build (TREE_CODE (arg0), type, a00,
6128 fold (build (code, type, a01, a11))));
6129 else if (commutative && operand_equal_p (a00, a11, 0))
6130 return fold (build (TREE_CODE (arg0), type, a00,
6131 fold (build (code, type, a01, a10))));
6132 else if (commutative && operand_equal_p (a01, a10, 0))
6133 return fold (build (TREE_CODE (arg0), type, a01,
6134 fold (build (code, type, a00, a11))));
6136 /* This case if tricky because we must either have commutative
6137 operators or else A10 must not have side-effects. */
6139 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
6140 && operand_equal_p (a01, a11, 0))
6141 return fold (build (TREE_CODE (arg0), type,
6142 fold (build (code, type, a00, a10)),
6146 /* See if we can build a range comparison. */
6147 if (0 != (tem = fold_range_test (t)))
6150 /* Check for the possibility of merging component references. If our
6151 lhs is another similar operation, try to merge its rhs with our
6152 rhs. Then try to merge our lhs and rhs. */
6153 if (TREE_CODE (arg0) == code
6154 && 0 != (tem = fold_truthop (code, type,
6155 TREE_OPERAND (arg0, 1), arg1)))
6156 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6158 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
6163 case TRUTH_ORIF_EXPR:
6164 /* Note that the operands of this must be ints
6165 and their values must be 0 or true.
6166 ("true" is a fixed value perhaps depending on the language.) */
6167 /* If first arg is constant true, return it. */
6168 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
6169 return convert (type, arg0);
6171 /* If either arg is constant zero, drop it. */
6172 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
6173 return non_lvalue (convert (type, arg1));
6174 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
6175 /* Preserve sequence points. */
6176 && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
6177 return non_lvalue (convert (type, arg0));
6178 /* If second arg is constant true, result is true, but we must
6179 evaluate first arg. */
6180 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
6181 return omit_one_operand (type, arg1, arg0);
6182 /* Likewise for first arg, but note this only occurs here for
6184 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
6185 return omit_one_operand (type, arg0, arg1);
6188 case TRUTH_XOR_EXPR:
6189 /* If either arg is constant zero, drop it. */
6190 if (integer_zerop (arg0))
6191 return non_lvalue (convert (type, arg1));
6192 if (integer_zerop (arg1))
6193 return non_lvalue (convert (type, arg0));
6194 /* If either arg is constant true, this is a logical inversion. */
6195 if (integer_onep (arg0))
6196 return non_lvalue (convert (type, invert_truthvalue (arg1)));
6197 if (integer_onep (arg1))
6198 return non_lvalue (convert (type, invert_truthvalue (arg0)));
6207 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
6209 /* (-a) CMP (-b) -> b CMP a */
6210 if (TREE_CODE (arg0) == NEGATE_EXPR
6211 && TREE_CODE (arg1) == NEGATE_EXPR)
6212 return fold (build (code, type, TREE_OPERAND (arg1, 0),
6213 TREE_OPERAND (arg0, 0)));
6214 /* (-a) CMP CST -> a swap(CMP) (-CST) */
6215 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == REAL_CST)
6218 (swap_tree_comparison (code), type,
6219 TREE_OPERAND (arg0, 0),
6220 build_real (TREE_TYPE (arg1),
6221 REAL_VALUE_NEGATE (TREE_REAL_CST (arg1)))));
6222 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
6223 /* a CMP (-0) -> a CMP 0 */
6224 if (TREE_CODE (arg1) == REAL_CST
6225 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (arg1)))
6226 return fold (build (code, type, arg0,
6227 build_real (TREE_TYPE (arg1), dconst0)));
6230 /* If one arg is a constant integer, put it last. */
6231 if (TREE_CODE (arg0) == INTEGER_CST
6232 && TREE_CODE (arg1) != INTEGER_CST)
6234 TREE_OPERAND (t, 0) = arg1;
6235 TREE_OPERAND (t, 1) = arg0;
6236 arg0 = TREE_OPERAND (t, 0);
6237 arg1 = TREE_OPERAND (t, 1);
6238 code = swap_tree_comparison (code);
6239 TREE_SET_CODE (t, code);
6242 /* Convert foo++ == CONST into ++foo == CONST + INCR.
6243 First, see if one arg is constant; find the constant arg
6244 and the other one. */
6246 tree constop = 0, varop = NULL_TREE;
6247 int constopnum = -1;
6249 if (TREE_CONSTANT (arg1))
6250 constopnum = 1, constop = arg1, varop = arg0;
6251 if (TREE_CONSTANT (arg0))
6252 constopnum = 0, constop = arg0, varop = arg1;
6254 if (constop && TREE_CODE (varop) == POSTINCREMENT_EXPR)
6256 /* This optimization is invalid for ordered comparisons
6257 if CONST+INCR overflows or if foo+incr might overflow.
6258 This optimization is invalid for floating point due to rounding.
6259 For pointer types we assume overflow doesn't happen. */
6260 if (POINTER_TYPE_P (TREE_TYPE (varop))
6261 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
6262 && (code == EQ_EXPR || code == NE_EXPR)))
6265 = fold (build (PLUS_EXPR, TREE_TYPE (varop),
6266 constop, TREE_OPERAND (varop, 1)));
6268 /* Do not overwrite the current varop to be a preincrement,
6269 create a new node so that we won't confuse our caller who
6270 might create trees and throw them away, reusing the
6271 arguments that they passed to build. This shows up in
6272 the THEN or ELSE parts of ?: being postincrements. */
6273 varop = build (PREINCREMENT_EXPR, TREE_TYPE (varop),
6274 TREE_OPERAND (varop, 0),
6275 TREE_OPERAND (varop, 1));
6277 /* If VAROP is a reference to a bitfield, we must mask
6278 the constant by the width of the field. */
6279 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
6280 && DECL_BIT_FIELD(TREE_OPERAND
6281 (TREE_OPERAND (varop, 0), 1)))
6284 = TREE_INT_CST_LOW (DECL_SIZE
6286 (TREE_OPERAND (varop, 0), 1)));
6287 tree mask, unsigned_type;
6288 unsigned int precision;
6289 tree folded_compare;
6291 /* First check whether the comparison would come out
6292 always the same. If we don't do that we would
6293 change the meaning with the masking. */
6294 if (constopnum == 0)
6295 folded_compare = fold (build (code, type, constop,
6296 TREE_OPERAND (varop, 0)));
6298 folded_compare = fold (build (code, type,
6299 TREE_OPERAND (varop, 0),
6301 if (integer_zerop (folded_compare)
6302 || integer_onep (folded_compare))
6303 return omit_one_operand (type, folded_compare, varop);
6305 unsigned_type = type_for_size (size, 1);
6306 precision = TYPE_PRECISION (unsigned_type);
6307 mask = build_int_2 (~0, ~0);
6308 TREE_TYPE (mask) = unsigned_type;
6309 force_fit_type (mask, 0);
6310 mask = const_binop (RSHIFT_EXPR, mask,
6311 size_int (precision - size), 0);
6312 newconst = fold (build (BIT_AND_EXPR,
6313 TREE_TYPE (varop), newconst,
6314 convert (TREE_TYPE (varop),
6318 t = build (code, type,
6319 (constopnum == 0) ? newconst : varop,
6320 (constopnum == 1) ? newconst : varop);
6324 else if (constop && TREE_CODE (varop) == POSTDECREMENT_EXPR)
6326 if (POINTER_TYPE_P (TREE_TYPE (varop))
6327 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
6328 && (code == EQ_EXPR || code == NE_EXPR)))
6331 = fold (build (MINUS_EXPR, TREE_TYPE (varop),
6332 constop, TREE_OPERAND (varop, 1)));
6334 /* Do not overwrite the current varop to be a predecrement,
6335 create a new node so that we won't confuse our caller who
6336 might create trees and throw them away, reusing the
6337 arguments that they passed to build. This shows up in
6338 the THEN or ELSE parts of ?: being postdecrements. */
6339 varop = build (PREDECREMENT_EXPR, TREE_TYPE (varop),
6340 TREE_OPERAND (varop, 0),
6341 TREE_OPERAND (varop, 1));
6343 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
6344 && DECL_BIT_FIELD(TREE_OPERAND
6345 (TREE_OPERAND (varop, 0), 1)))
6348 = TREE_INT_CST_LOW (DECL_SIZE
6350 (TREE_OPERAND (varop, 0), 1)));
6351 tree mask, unsigned_type;
6352 unsigned int precision;
6353 tree folded_compare;
6355 if (constopnum == 0)
6356 folded_compare = fold (build (code, type, constop,
6357 TREE_OPERAND (varop, 0)));
6359 folded_compare = fold (build (code, type,
6360 TREE_OPERAND (varop, 0),
6362 if (integer_zerop (folded_compare)
6363 || integer_onep (folded_compare))
6364 return omit_one_operand (type, folded_compare, varop);
6366 unsigned_type = type_for_size (size, 1);
6367 precision = TYPE_PRECISION (unsigned_type);
6368 mask = build_int_2 (~0, ~0);
6369 TREE_TYPE (mask) = TREE_TYPE (varop);
6370 force_fit_type (mask, 0);
6371 mask = const_binop (RSHIFT_EXPR, mask,
6372 size_int (precision - size), 0);
6373 newconst = fold (build (BIT_AND_EXPR,
6374 TREE_TYPE (varop), newconst,
6375 convert (TREE_TYPE (varop),
6379 t = build (code, type,
6380 (constopnum == 0) ? newconst : varop,
6381 (constopnum == 1) ? newconst : varop);
6387 /* Change X >= CST to X > (CST - 1) if CST is positive. */
6388 if (TREE_CODE (arg1) == INTEGER_CST
6389 && TREE_CODE (arg0) != INTEGER_CST
6390 && tree_int_cst_sgn (arg1) > 0)
6392 switch (TREE_CODE (t))
6396 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6397 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6402 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6403 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6411 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
6412 a MINUS_EXPR of a constant, we can convert it into a comparison with
6413 a revised constant as long as no overflow occurs. */
6414 if ((code == EQ_EXPR || code == NE_EXPR)
6415 && TREE_CODE (arg1) == INTEGER_CST
6416 && (TREE_CODE (arg0) == PLUS_EXPR
6417 || TREE_CODE (arg0) == MINUS_EXPR)
6418 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6419 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
6420 ? MINUS_EXPR : PLUS_EXPR,
6421 arg1, TREE_OPERAND (arg0, 1), 0))
6422 && ! TREE_CONSTANT_OVERFLOW (tem))
6423 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6425 /* Similarly for a NEGATE_EXPR. */
6426 else if ((code == EQ_EXPR || code == NE_EXPR)
6427 && TREE_CODE (arg0) == NEGATE_EXPR
6428 && TREE_CODE (arg1) == INTEGER_CST
6429 && 0 != (tem = negate_expr (arg1))
6430 && TREE_CODE (tem) == INTEGER_CST
6431 && ! TREE_CONSTANT_OVERFLOW (tem))
6432 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6434 /* If we have X - Y == 0, we can convert that to X == Y and similarly
6435 for !=. Don't do this for ordered comparisons due to overflow. */
6436 else if ((code == NE_EXPR || code == EQ_EXPR)
6437 && integer_zerop (arg1) && TREE_CODE (arg0) == MINUS_EXPR)
6438 return fold (build (code, type,
6439 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1)));
6441 /* If we are widening one operand of an integer comparison,
6442 see if the other operand is similarly being widened. Perhaps we
6443 can do the comparison in the narrower type. */
6444 else if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
6445 && TREE_CODE (arg0) == NOP_EXPR
6446 && (tem = get_unwidened (arg0, NULL_TREE)) != arg0
6447 && (t1 = get_unwidened (arg1, TREE_TYPE (tem))) != 0
6448 && (TREE_TYPE (t1) == TREE_TYPE (tem)
6449 || (TREE_CODE (t1) == INTEGER_CST
6450 && int_fits_type_p (t1, TREE_TYPE (tem)))))
6451 return fold (build (code, type, tem, convert (TREE_TYPE (tem), t1)));
6453 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
6454 constant, we can simplify it. */
6455 else if (TREE_CODE (arg1) == INTEGER_CST
6456 && (TREE_CODE (arg0) == MIN_EXPR
6457 || TREE_CODE (arg0) == MAX_EXPR)
6458 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
6459 return optimize_minmax_comparison (t);
6461 /* If we are comparing an ABS_EXPR with a constant, we can
6462 convert all the cases into explicit comparisons, but they may
6463 well not be faster than doing the ABS and one comparison.
6464 But ABS (X) <= C is a range comparison, which becomes a subtraction
6465 and a comparison, and is probably faster. */
6466 else if (code == LE_EXPR && TREE_CODE (arg1) == INTEGER_CST
6467 && TREE_CODE (arg0) == ABS_EXPR
6468 && ! TREE_SIDE_EFFECTS (arg0)
6469 && (0 != (tem = negate_expr (arg1)))
6470 && TREE_CODE (tem) == INTEGER_CST
6471 && ! TREE_CONSTANT_OVERFLOW (tem))
6472 return fold (build (TRUTH_ANDIF_EXPR, type,
6473 build (GE_EXPR, type, TREE_OPERAND (arg0, 0), tem),
6474 build (LE_EXPR, type,
6475 TREE_OPERAND (arg0, 0), arg1)));
6477 /* If this is an EQ or NE comparison with zero and ARG0 is
6478 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
6479 two operations, but the latter can be done in one less insn
6480 on machines that have only two-operand insns or on which a
6481 constant cannot be the first operand. */
6482 if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR)
6483 && TREE_CODE (arg0) == BIT_AND_EXPR)
6485 if (TREE_CODE (TREE_OPERAND (arg0, 0)) == LSHIFT_EXPR
6486 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 0), 0)))
6488 fold (build (code, type,
6489 build (BIT_AND_EXPR, TREE_TYPE (arg0),
6491 TREE_TYPE (TREE_OPERAND (arg0, 0)),
6492 TREE_OPERAND (arg0, 1),
6493 TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)),
6494 convert (TREE_TYPE (arg0),
6497 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
6498 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
6500 fold (build (code, type,
6501 build (BIT_AND_EXPR, TREE_TYPE (arg0),
6503 TREE_TYPE (TREE_OPERAND (arg0, 1)),
6504 TREE_OPERAND (arg0, 0),
6505 TREE_OPERAND (TREE_OPERAND (arg0, 1), 1)),
6506 convert (TREE_TYPE (arg0),
6511 /* If this is an NE or EQ comparison of zero against the result of a
6512 signed MOD operation whose second operand is a power of 2, make
6513 the MOD operation unsigned since it is simpler and equivalent. */
6514 if ((code == NE_EXPR || code == EQ_EXPR)
6515 && integer_zerop (arg1)
6516 && ! TREE_UNSIGNED (TREE_TYPE (arg0))
6517 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
6518 || TREE_CODE (arg0) == CEIL_MOD_EXPR
6519 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
6520 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
6521 && integer_pow2p (TREE_OPERAND (arg0, 1)))
6523 tree newtype = unsigned_type (TREE_TYPE (arg0));
6524 tree newmod = build (TREE_CODE (arg0), newtype,
6525 convert (newtype, TREE_OPERAND (arg0, 0)),
6526 convert (newtype, TREE_OPERAND (arg0, 1)));
6528 return build (code, type, newmod, convert (newtype, arg1));
6531 /* If this is an NE comparison of zero with an AND of one, remove the
6532 comparison since the AND will give the correct value. */
6533 if (code == NE_EXPR && integer_zerop (arg1)
6534 && TREE_CODE (arg0) == BIT_AND_EXPR
6535 && integer_onep (TREE_OPERAND (arg0, 1)))
6536 return convert (type, arg0);
6538 /* If we have (A & C) == C where C is a power of 2, convert this into
6539 (A & C) != 0. Similarly for NE_EXPR. */
6540 if ((code == EQ_EXPR || code == NE_EXPR)
6541 && TREE_CODE (arg0) == BIT_AND_EXPR
6542 && integer_pow2p (TREE_OPERAND (arg0, 1))
6543 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
6544 return build (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
6545 arg0, integer_zero_node);
6547 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
6548 and similarly for >= into !=. */
6549 if ((code == LT_EXPR || code == GE_EXPR)
6550 && TREE_UNSIGNED (TREE_TYPE (arg0))
6551 && TREE_CODE (arg1) == LSHIFT_EXPR
6552 && integer_onep (TREE_OPERAND (arg1, 0)))
6553 return build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
6554 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
6555 TREE_OPERAND (arg1, 1)),
6556 convert (TREE_TYPE (arg0), integer_zero_node));
6558 else if ((code == LT_EXPR || code == GE_EXPR)
6559 && TREE_UNSIGNED (TREE_TYPE (arg0))
6560 && (TREE_CODE (arg1) == NOP_EXPR
6561 || TREE_CODE (arg1) == CONVERT_EXPR)
6562 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
6563 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
6565 build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
6566 convert (TREE_TYPE (arg0),
6567 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
6568 TREE_OPERAND (TREE_OPERAND (arg1, 0), 1))),
6569 convert (TREE_TYPE (arg0), integer_zero_node));
6571 /* Simplify comparison of something with itself. (For IEEE
6572 floating-point, we can only do some of these simplifications.) */
6573 if (operand_equal_p (arg0, arg1, 0))
6580 if (! FLOAT_TYPE_P (TREE_TYPE (arg0)))
6581 return constant_boolean_node (1, type);
6583 TREE_SET_CODE (t, code);
6587 /* For NE, we can only do this simplification if integer. */
6588 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
6590 /* ... fall through ... */
6593 return constant_boolean_node (0, type);
6599 /* An unsigned comparison against 0 can be simplified. */
6600 if (integer_zerop (arg1)
6601 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
6602 || POINTER_TYPE_P (TREE_TYPE (arg1)))
6603 && TREE_UNSIGNED (TREE_TYPE (arg1)))
6605 switch (TREE_CODE (t))
6609 TREE_SET_CODE (t, NE_EXPR);
6613 TREE_SET_CODE (t, EQ_EXPR);
6616 return omit_one_operand (type,
6617 convert (type, integer_one_node),
6620 return omit_one_operand (type,
6621 convert (type, integer_zero_node),
6628 /* Comparisons with the highest or lowest possible integer of
6629 the specified size will have known values and an unsigned
6630 <= 0x7fffffff can be simplified. */
6632 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1)));
6634 if (TREE_CODE (arg1) == INTEGER_CST
6635 && ! TREE_CONSTANT_OVERFLOW (arg1)
6636 && width <= HOST_BITS_PER_WIDE_INT
6637 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
6638 || POINTER_TYPE_P (TREE_TYPE (arg1))))
6640 if (TREE_INT_CST_HIGH (arg1) == 0
6641 && (TREE_INT_CST_LOW (arg1)
6642 == ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1)
6643 && ! TREE_UNSIGNED (TREE_TYPE (arg1)))
6644 switch (TREE_CODE (t))
6647 return omit_one_operand (type,
6648 convert (type, integer_zero_node),
6651 TREE_SET_CODE (t, EQ_EXPR);
6655 return omit_one_operand (type,
6656 convert (type, integer_one_node),
6659 TREE_SET_CODE (t, NE_EXPR);
6666 else if (TREE_INT_CST_HIGH (arg1) == -1
6667 && (- TREE_INT_CST_LOW (arg1)
6668 == ((unsigned HOST_WIDE_INT) 1 << (width - 1)))
6669 && ! TREE_UNSIGNED (TREE_TYPE (arg1)))
6670 switch (TREE_CODE (t))
6673 return omit_one_operand (type,
6674 convert (type, integer_zero_node),
6677 TREE_SET_CODE (t, EQ_EXPR);
6681 return omit_one_operand (type,
6682 convert (type, integer_one_node),
6685 TREE_SET_CODE (t, NE_EXPR);
6692 else if (TREE_INT_CST_HIGH (arg1) == 0
6693 && (TREE_INT_CST_LOW (arg1)
6694 == ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1)
6695 && TREE_UNSIGNED (TREE_TYPE (arg1))
6696 /* signed_type does not work on pointer types. */
6697 && INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
6699 switch (TREE_CODE (t))
6702 return fold (build (GE_EXPR, type,
6703 convert (signed_type (TREE_TYPE (arg0)),
6705 convert (signed_type (TREE_TYPE (arg1)),
6706 integer_zero_node)));
6708 return fold (build (LT_EXPR, type,
6709 convert (signed_type (TREE_TYPE (arg0)),
6711 convert (signed_type (TREE_TYPE (arg1)),
6712 integer_zero_node)));
6720 /* If we are comparing an expression that just has comparisons
6721 of two integer values, arithmetic expressions of those comparisons,
6722 and constants, we can simplify it. There are only three cases
6723 to check: the two values can either be equal, the first can be
6724 greater, or the second can be greater. Fold the expression for
6725 those three values. Since each value must be 0 or 1, we have
6726 eight possibilities, each of which corresponds to the constant 0
6727 or 1 or one of the six possible comparisons.
6729 This handles common cases like (a > b) == 0 but also handles
6730 expressions like ((x > y) - (y > x)) > 0, which supposedly
6731 occur in macroized code. */
6733 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
6735 tree cval1 = 0, cval2 = 0;
6738 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
6739 /* Don't handle degenerate cases here; they should already
6740 have been handled anyway. */
6741 && cval1 != 0 && cval2 != 0
6742 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
6743 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
6744 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
6745 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
6746 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
6747 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
6748 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
6750 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
6751 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
6753 /* We can't just pass T to eval_subst in case cval1 or cval2
6754 was the same as ARG1. */
6757 = fold (build (code, type,
6758 eval_subst (arg0, cval1, maxval, cval2, minval),
6761 = fold (build (code, type,
6762 eval_subst (arg0, cval1, maxval, cval2, maxval),
6765 = fold (build (code, type,
6766 eval_subst (arg0, cval1, minval, cval2, maxval),
6769 /* All three of these results should be 0 or 1. Confirm they
6770 are. Then use those values to select the proper code
6773 if ((integer_zerop (high_result)
6774 || integer_onep (high_result))
6775 && (integer_zerop (equal_result)
6776 || integer_onep (equal_result))
6777 && (integer_zerop (low_result)
6778 || integer_onep (low_result)))
6780 /* Make a 3-bit mask with the high-order bit being the
6781 value for `>', the next for '=', and the low for '<'. */
6782 switch ((integer_onep (high_result) * 4)
6783 + (integer_onep (equal_result) * 2)
6784 + integer_onep (low_result))
6788 return omit_one_operand (type, integer_zero_node, arg0);
6809 return omit_one_operand (type, integer_one_node, arg0);
6812 t = build (code, type, cval1, cval2);
6814 return save_expr (t);
6821 /* If this is a comparison of a field, we may be able to simplify it. */
6822 if ((TREE_CODE (arg0) == COMPONENT_REF
6823 || TREE_CODE (arg0) == BIT_FIELD_REF)
6824 && (code == EQ_EXPR || code == NE_EXPR)
6825 /* Handle the constant case even without -O
6826 to make sure the warnings are given. */
6827 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
6829 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
6833 /* If this is a comparison of complex values and either or both sides
6834 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
6835 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
6836 This may prevent needless evaluations. */
6837 if ((code == EQ_EXPR || code == NE_EXPR)
6838 && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
6839 && (TREE_CODE (arg0) == COMPLEX_EXPR
6840 || TREE_CODE (arg1) == COMPLEX_EXPR
6841 || TREE_CODE (arg0) == COMPLEX_CST
6842 || TREE_CODE (arg1) == COMPLEX_CST))
6844 tree subtype = TREE_TYPE (TREE_TYPE (arg0));
6845 tree real0, imag0, real1, imag1;
6847 arg0 = save_expr (arg0);
6848 arg1 = save_expr (arg1);
6849 real0 = fold (build1 (REALPART_EXPR, subtype, arg0));
6850 imag0 = fold (build1 (IMAGPART_EXPR, subtype, arg0));
6851 real1 = fold (build1 (REALPART_EXPR, subtype, arg1));
6852 imag1 = fold (build1 (IMAGPART_EXPR, subtype, arg1));
6854 return fold (build ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR
6857 fold (build (code, type, real0, real1)),
6858 fold (build (code, type, imag0, imag1))));
6861 /* From here on, the only cases we handle are when the result is
6862 known to be a constant.
6864 To compute GT, swap the arguments and do LT.
6865 To compute GE, do LT and invert the result.
6866 To compute LE, swap the arguments, do LT and invert the result.
6867 To compute NE, do EQ and invert the result.
6869 Therefore, the code below must handle only EQ and LT. */
6871 if (code == LE_EXPR || code == GT_EXPR)
6873 tem = arg0, arg0 = arg1, arg1 = tem;
6874 code = swap_tree_comparison (code);
6877 /* Note that it is safe to invert for real values here because we
6878 will check below in the one case that it matters. */
6882 if (code == NE_EXPR || code == GE_EXPR)
6885 code = invert_tree_comparison (code);
6888 /* Compute a result for LT or EQ if args permit;
6889 otherwise return T. */
6890 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
6892 if (code == EQ_EXPR)
6893 t1 = build_int_2 (tree_int_cst_equal (arg0, arg1), 0);
6895 t1 = build_int_2 ((TREE_UNSIGNED (TREE_TYPE (arg0))
6896 ? INT_CST_LT_UNSIGNED (arg0, arg1)
6897 : INT_CST_LT (arg0, arg1)),
6901 #if 0 /* This is no longer useful, but breaks some real code. */
6902 /* Assume a nonexplicit constant cannot equal an explicit one,
6903 since such code would be undefined anyway.
6904 Exception: on sysvr4, using #pragma weak,
6905 a label can come out as 0. */
6906 else if (TREE_CODE (arg1) == INTEGER_CST
6907 && !integer_zerop (arg1)
6908 && TREE_CONSTANT (arg0)
6909 && TREE_CODE (arg0) == ADDR_EXPR
6911 t1 = build_int_2 (0, 0);
6913 /* Two real constants can be compared explicitly. */
6914 else if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
6916 /* If either operand is a NaN, the result is false with two
6917 exceptions: First, an NE_EXPR is true on NaNs, but that case
6918 is already handled correctly since we will be inverting the
6919 result for NE_EXPR. Second, if we had inverted a LE_EXPR
6920 or a GE_EXPR into a LT_EXPR, we must return true so that it
6921 will be inverted into false. */
6923 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
6924 || REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
6925 t1 = build_int_2 (invert && code == LT_EXPR, 0);
6927 else if (code == EQ_EXPR)
6928 t1 = build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (arg0),
6929 TREE_REAL_CST (arg1)),
6932 t1 = build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (arg0),
6933 TREE_REAL_CST (arg1)),
6937 if (t1 == NULL_TREE)
6941 TREE_INT_CST_LOW (t1) ^= 1;
6943 TREE_TYPE (t1) = type;
6944 if (TREE_CODE (type) == BOOLEAN_TYPE)
6945 return truthvalue_conversion (t1);
6949 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
6950 so all simple results must be passed through pedantic_non_lvalue. */
6951 if (TREE_CODE (arg0) == INTEGER_CST)
6952 return pedantic_non_lvalue
6953 (TREE_OPERAND (t, (integer_zerop (arg0) ? 2 : 1)));
6954 else if (operand_equal_p (arg1, TREE_OPERAND (expr, 2), 0))
6955 return pedantic_omit_one_operand (type, arg1, arg0);
6957 /* If the second operand is zero, invert the comparison and swap
6958 the second and third operands. Likewise if the second operand
6959 is constant and the third is not or if the third operand is
6960 equivalent to the first operand of the comparison. */
6962 if (integer_zerop (arg1)
6963 || (TREE_CONSTANT (arg1) && ! TREE_CONSTANT (TREE_OPERAND (t, 2)))
6964 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
6965 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
6966 TREE_OPERAND (t, 2),
6967 TREE_OPERAND (arg0, 1))))
6969 /* See if this can be inverted. If it can't, possibly because
6970 it was a floating-point inequality comparison, don't do
6972 tem = invert_truthvalue (arg0);
6974 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
6976 t = build (code, type, tem,
6977 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
6979 /* arg1 should be the first argument of the new T. */
6980 arg1 = TREE_OPERAND (t, 1);
6985 /* If we have A op B ? A : C, we may be able to convert this to a
6986 simpler expression, depending on the operation and the values
6987 of B and C. IEEE floating point prevents this though,
6988 because A or B might be -0.0 or a NaN. */
6990 if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
6991 && (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
6992 || ! FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 0)))
6993 || flag_unsafe_math_optimizations)
6994 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
6995 arg1, TREE_OPERAND (arg0, 1)))
6997 tree arg2 = TREE_OPERAND (t, 2);
6998 enum tree_code comp_code = TREE_CODE (arg0);
7002 /* If we have A op 0 ? A : -A, this is A, -A, abs (A), or abs (-A),
7003 depending on the comparison operation. */
7004 if ((FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 1)))
7005 ? real_zerop (TREE_OPERAND (arg0, 1))
7006 : integer_zerop (TREE_OPERAND (arg0, 1)))
7007 && TREE_CODE (arg2) == NEGATE_EXPR
7008 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
7016 (convert (TREE_TYPE (TREE_OPERAND (t, 1)),
7020 return pedantic_non_lvalue (convert (type, arg1));
7023 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
7024 arg1 = convert (signed_type (TREE_TYPE (arg1)), arg1);
7025 return pedantic_non_lvalue
7026 (convert (type, fold (build1 (ABS_EXPR,
7027 TREE_TYPE (arg1), arg1))));
7030 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
7031 arg1 = convert (signed_type (TREE_TYPE (arg1)), arg1);
7032 return pedantic_non_lvalue
7033 (negate_expr (convert (type,
7034 fold (build1 (ABS_EXPR,
7041 /* If this is A != 0 ? A : 0, this is simply A. For ==, it is
7044 if (integer_zerop (TREE_OPERAND (arg0, 1)) && integer_zerop (arg2))
7046 if (comp_code == NE_EXPR)
7047 return pedantic_non_lvalue (convert (type, arg1));
7048 else if (comp_code == EQ_EXPR)
7049 return pedantic_non_lvalue (convert (type, integer_zero_node));
7052 /* If this is A op B ? A : B, this is either A, B, min (A, B),
7053 or max (A, B), depending on the operation. */
7055 if (operand_equal_for_comparison_p (TREE_OPERAND (arg0, 1),
7056 arg2, TREE_OPERAND (arg0, 0)))
7058 tree comp_op0 = TREE_OPERAND (arg0, 0);
7059 tree comp_op1 = TREE_OPERAND (arg0, 1);
7060 tree comp_type = TREE_TYPE (comp_op0);
7062 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
7063 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
7069 return pedantic_non_lvalue (convert (type, arg2));
7071 return pedantic_non_lvalue (convert (type, arg1));
7074 /* In C++ a ?: expression can be an lvalue, so put the
7075 operand which will be used if they are equal first
7076 so that we can convert this back to the
7077 corresponding COND_EXPR. */
7078 return pedantic_non_lvalue
7079 (convert (type, fold (build (MIN_EXPR, comp_type,
7080 (comp_code == LE_EXPR
7081 ? comp_op0 : comp_op1),
7082 (comp_code == LE_EXPR
7083 ? comp_op1 : comp_op0)))));
7087 return pedantic_non_lvalue
7088 (convert (type, fold (build (MAX_EXPR, comp_type,
7089 (comp_code == GE_EXPR
7090 ? comp_op0 : comp_op1),
7091 (comp_code == GE_EXPR
7092 ? comp_op1 : comp_op0)))));
7099 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
7100 we might still be able to simplify this. For example,
7101 if C1 is one less or one more than C2, this might have started
7102 out as a MIN or MAX and been transformed by this function.
7103 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
7105 if (INTEGRAL_TYPE_P (type)
7106 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7107 && TREE_CODE (arg2) == INTEGER_CST)
7111 /* We can replace A with C1 in this case. */
7112 arg1 = convert (type, TREE_OPERAND (arg0, 1));
7113 t = build (code, type, TREE_OPERAND (t, 0), arg1,
7114 TREE_OPERAND (t, 2));
7118 /* If C1 is C2 + 1, this is min(A, C2). */
7119 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
7120 && operand_equal_p (TREE_OPERAND (arg0, 1),
7121 const_binop (PLUS_EXPR, arg2,
7122 integer_one_node, 0), 1))
7123 return pedantic_non_lvalue
7124 (fold (build (MIN_EXPR, type, arg1, arg2)));
7128 /* If C1 is C2 - 1, this is min(A, C2). */
7129 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
7130 && operand_equal_p (TREE_OPERAND (arg0, 1),
7131 const_binop (MINUS_EXPR, arg2,
7132 integer_one_node, 0), 1))
7133 return pedantic_non_lvalue
7134 (fold (build (MIN_EXPR, type, arg1, arg2)));
7138 /* If C1 is C2 - 1, this is max(A, C2). */
7139 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
7140 && operand_equal_p (TREE_OPERAND (arg0, 1),
7141 const_binop (MINUS_EXPR, arg2,
7142 integer_one_node, 0), 1))
7143 return pedantic_non_lvalue
7144 (fold (build (MAX_EXPR, type, arg1, arg2)));
7148 /* If C1 is C2 + 1, this is max(A, C2). */
7149 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
7150 && operand_equal_p (TREE_OPERAND (arg0, 1),
7151 const_binop (PLUS_EXPR, arg2,
7152 integer_one_node, 0), 1))
7153 return pedantic_non_lvalue
7154 (fold (build (MAX_EXPR, type, arg1, arg2)));
7163 /* If the second operand is simpler than the third, swap them
7164 since that produces better jump optimization results. */
7165 if ((TREE_CONSTANT (arg1) || DECL_P (arg1)
7166 || TREE_CODE (arg1) == SAVE_EXPR)
7167 && ! (TREE_CONSTANT (TREE_OPERAND (t, 2))
7168 || DECL_P (TREE_OPERAND (t, 2))
7169 || TREE_CODE (TREE_OPERAND (t, 2)) == SAVE_EXPR))
7171 /* See if this can be inverted. If it can't, possibly because
7172 it was a floating-point inequality comparison, don't do
7174 tem = invert_truthvalue (arg0);
7176 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
7178 t = build (code, type, tem,
7179 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
7181 /* arg1 should be the first argument of the new T. */
7182 arg1 = TREE_OPERAND (t, 1);
7187 /* Convert A ? 1 : 0 to simply A. */
7188 if (integer_onep (TREE_OPERAND (t, 1))
7189 && integer_zerop (TREE_OPERAND (t, 2))
7190 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
7191 call to fold will try to move the conversion inside
7192 a COND, which will recurse. In that case, the COND_EXPR
7193 is probably the best choice, so leave it alone. */
7194 && type == TREE_TYPE (arg0))
7195 return pedantic_non_lvalue (arg0);
7197 /* Look for expressions of the form A & 2 ? 2 : 0. The result of this
7198 operation is simply A & 2. */
7200 if (integer_zerop (TREE_OPERAND (t, 2))
7201 && TREE_CODE (arg0) == NE_EXPR
7202 && integer_zerop (TREE_OPERAND (arg0, 1))
7203 && integer_pow2p (arg1)
7204 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
7205 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
7207 return pedantic_non_lvalue (convert (type, TREE_OPERAND (arg0, 0)));
7212 /* When pedantic, a compound expression can be neither an lvalue
7213 nor an integer constant expression. */
7214 if (TREE_SIDE_EFFECTS (arg0) || pedantic)
7216 /* Don't let (0, 0) be null pointer constant. */
7217 if (integer_zerop (arg1))
7218 return build1 (NOP_EXPR, type, arg1);
7219 return convert (type, arg1);
7223 return build_complex (type, arg0, arg1);
7227 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7229 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
7230 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
7231 TREE_OPERAND (arg0, 1));
7232 else if (TREE_CODE (arg0) == COMPLEX_CST)
7233 return TREE_REALPART (arg0);
7234 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7235 return fold (build (TREE_CODE (arg0), type,
7236 fold (build1 (REALPART_EXPR, type,
7237 TREE_OPERAND (arg0, 0))),
7238 fold (build1 (REALPART_EXPR,
7239 type, TREE_OPERAND (arg0, 1)))));
7243 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7244 return convert (type, integer_zero_node);
7245 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
7246 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
7247 TREE_OPERAND (arg0, 0));
7248 else if (TREE_CODE (arg0) == COMPLEX_CST)
7249 return TREE_IMAGPART (arg0);
7250 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7251 return fold (build (TREE_CODE (arg0), type,
7252 fold (build1 (IMAGPART_EXPR, type,
7253 TREE_OPERAND (arg0, 0))),
7254 fold (build1 (IMAGPART_EXPR, type,
7255 TREE_OPERAND (arg0, 1)))));
7258 /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
7260 case CLEANUP_POINT_EXPR:
7261 if (! has_cleanups (arg0))
7262 return TREE_OPERAND (t, 0);
7265 enum tree_code code0 = TREE_CODE (arg0);
7266 int kind0 = TREE_CODE_CLASS (code0);
7267 tree arg00 = TREE_OPERAND (arg0, 0);
7270 if (kind0 == '1' || code0 == TRUTH_NOT_EXPR)
7271 return fold (build1 (code0, type,
7272 fold (build1 (CLEANUP_POINT_EXPR,
7273 TREE_TYPE (arg00), arg00))));
7275 if (kind0 == '<' || kind0 == '2'
7276 || code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR
7277 || code0 == TRUTH_AND_EXPR || code0 == TRUTH_OR_EXPR
7278 || code0 == TRUTH_XOR_EXPR)
7280 arg01 = TREE_OPERAND (arg0, 1);
7282 if (TREE_CONSTANT (arg00)
7283 || ((code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR)
7284 && ! has_cleanups (arg00)))
7285 return fold (build (code0, type, arg00,
7286 fold (build1 (CLEANUP_POINT_EXPR,
7287 TREE_TYPE (arg01), arg01))));
7289 if (TREE_CONSTANT (arg01))
7290 return fold (build (code0, type,
7291 fold (build1 (CLEANUP_POINT_EXPR,
7292 TREE_TYPE (arg00), arg00)),
7300 /* Check for a built-in function. */
7301 if (TREE_CODE (TREE_OPERAND (expr, 0)) == ADDR_EXPR
7302 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (expr, 0), 0))
7304 && DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (expr, 0), 0)))
7306 tree tmp = fold_builtin (expr);
7314 } /* switch (code) */
7317 /* Determine if first argument is a multiple of second argument. Return 0 if
7318 it is not, or we cannot easily determined it to be.
7320 An example of the sort of thing we care about (at this point; this routine
7321 could surely be made more general, and expanded to do what the *_DIV_EXPR's
7322 fold cases do now) is discovering that
7324 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7330 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
7332 This code also handles discovering that
7334 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7336 is a multiple of 8 so we don't have to worry about dealing with a
7339 Note that we *look* inside a SAVE_EXPR only to determine how it was
7340 calculated; it is not safe for fold to do much of anything else with the
7341 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
7342 at run time. For example, the latter example above *cannot* be implemented
7343 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
7344 evaluation time of the original SAVE_EXPR is not necessarily the same at
7345 the time the new expression is evaluated. The only optimization of this
7346 sort that would be valid is changing
7348 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
7352 SAVE_EXPR (I) * SAVE_EXPR (J)
7354 (where the same SAVE_EXPR (J) is used in the original and the
7355 transformed version). */
7358 multiple_of_p (type, top, bottom)
7363 if (operand_equal_p (top, bottom, 0))
7366 if (TREE_CODE (type) != INTEGER_TYPE)
7369 switch (TREE_CODE (top))
7372 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
7373 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
7377 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
7378 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
7381 if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
7385 op1 = TREE_OPERAND (top, 1);
7386 /* const_binop may not detect overflow correctly,
7387 so check for it explicitly here. */
7388 if (TYPE_PRECISION (TREE_TYPE (size_one_node))
7389 > TREE_INT_CST_LOW (op1)
7390 && TREE_INT_CST_HIGH (op1) == 0
7391 && 0 != (t1 = convert (type,
7392 const_binop (LSHIFT_EXPR, size_one_node,
7394 && ! TREE_OVERFLOW (t1))
7395 return multiple_of_p (type, t1, bottom);
7400 /* Can't handle conversions from non-integral or wider integral type. */
7401 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
7402 || (TYPE_PRECISION (type)
7403 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
7406 /* .. fall through ... */
7409 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
7412 if (TREE_CODE (bottom) != INTEGER_CST
7413 || (TREE_UNSIGNED (type)
7414 && (tree_int_cst_sgn (top) < 0
7415 || tree_int_cst_sgn (bottom) < 0)))
7417 return integer_zerop (const_binop (TRUNC_MOD_EXPR,
7425 /* Return true if `t' is known to be non-negative. */
7428 tree_expr_nonnegative_p (t)
7431 switch (TREE_CODE (t))
7437 return tree_int_cst_sgn (t) >= 0;
7438 case TRUNC_DIV_EXPR:
7440 case FLOOR_DIV_EXPR:
7441 case ROUND_DIV_EXPR:
7442 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
7443 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
7444 case TRUNC_MOD_EXPR:
7446 case FLOOR_MOD_EXPR:
7447 case ROUND_MOD_EXPR:
7448 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
7450 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
7451 && tree_expr_nonnegative_p (TREE_OPERAND (t, 2));
7453 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
7455 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
7456 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
7458 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
7459 || tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
7461 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
7463 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
7465 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
7466 case NON_LVALUE_EXPR:
7467 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
7469 return rtl_expr_nonnegative_p (RTL_EXPR_RTL (t));
7472 if (truth_value_p (TREE_CODE (t)))
7473 /* Truth values evaluate to 0 or 1, which is nonnegative. */
7476 /* We don't know sign of `t', so be conservative and return false. */
7481 /* Return true if `r' is known to be non-negative.
7482 Only handles constants at the moment. */
7485 rtl_expr_nonnegative_p (r)
7488 switch (GET_CODE (r))
7491 return INTVAL (r) >= 0;
7494 if (GET_MODE (r) == VOIDmode)
7495 return CONST_DOUBLE_HIGH (r) >= 0;
7500 /* These are always nonnegative. */